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Students enjoy the sunshine while free-floating their ideas onto paper, using the RAFTS prompt. Empathy with natural objects and life forms is encouraged as they seek a role or vantage point from which to express their ideas (R) to a particular audience (A) by way of a particular format (F) on a nature topic (T) under study. The "S" that keeps their writing buoyant is a Strong (S) Verb. R.A.F.T.S. is a writing assignment designing strategy to help students writing "float." It enables the teacher or the student to design workable, varied writing prompts for a multitude of creative writing purposes. What is a "float?" - any piece of writing that floats from the R.A.F.T.S. strategy. R.A.F.T.S. supports writing by supplying: - a role from which to do the writing. The role may be as intimate as self or as remote as that of an inanimate object. Roles should be chosen from those that exist within the realms of the real or vicarious experience of the student. - an audience for whom the writing is intended. Students need to write for audiences other than the teacher. The audiences for student writing may range from self to peers to the general public. Variation in audiences causes the student to vary the form and the level of the language used to express meaning. - a format in which to write. Students need to experiment with a variety of formats. Writing formats should include typical school writing formats, but can also include as many type of "real life" writing as possible. - a topic about which to write. Topics should relate to the role and audiences selected. - a strong verb which sets the tone for a piece of writing. This strong verb also directs the student in Vocabulary choice. The assignment designing elements can be arranged in the following frame: As a (role) write a (format) to (audience) using (strong verb) about (topic). Sample of "Rafts" Objectives:
Mars is a funny little place, but it seems that Mars orbit may be even funnier. As we all know, Mars has two small and lumpy moons which would be no more than a pair of mundane asteroids if they weren’t orbiting Mars. Phobos and Deimos. But this seems to be only their latest incarnation. No one’s entirely sure about the origin of the two potatoes in orbit around Mars. Sharing their planet’s orbital space with 14 satellites we’ve sent there, many people believe that they were captured main belt asteroids. They do seem to share a lot in common with C-type and D-type asteroids, but their orbits seem a little too perfect. They’re quite close to being circular, and both lie perfectly in Mars’ equatorial plane. Orbital drag and tidal forces can do this, but with Mars’ low gravity and thin atmosphere, it’s difficult to make this theory work. Additionally, infrared spectra of Phobos and Mars show very similar phyllosilicate minerals, suggesting a common origin. A slightly more interesting possibility is that Mars may once have had rings, a little like Saturn, and Phobos and Deimos coalesced out of them. This may sound outlandish, but it’s a similar hypothesis to where we think Earth’s moon came from (with the big difference being that the Earth-Moon system is huge compared to the Mars system). And even asteroids can have rings, under the right circumstances! There’s certainly evidence for a huge impact on Mars sometime in the past. The Martian Dichotomy is the name given to the interesting fact that Mars’ northern hemisphere is dramatically different to its southern hemisphere. The northern hemisphere is 1-3 km lower in elevation, and has a crust nearly half as thick as the crust in the south. At least one theory is that the entire northern half of Mars is, essentially, a huge impact basin. An impact big enough to produce that kind of effect would be big enough to knock a lot of material into orbit. Some believe that this caused Mars’ orbit to have once been full of Phobos/Deimos-like objects. Others think it may have caused a ring system to form. Similarly to Earth, a ring system like that is thought to have formed into a large moon. Unlike Earth, that wasn’t the end of the story. In celestial mechanics, any object orbiting another has what’s known as a Roche limit. Any orbiting object which falls within this limit is destined to be torn apart by gravity. It’s described conveniently by this simple little equation; where Rm is the radius of the secondary, Mm is the mass of the secondary, and MM is the mass of the primary. The equation gives d, the distance at which the secondary starts to be torn apart by gravity. In this case, the primary would be Mars, and the secondary would be its ill-fated moon. So, one hypothesis goes that this former moon of Mars was ultimately shredded by the gravity of its parent planet. In fact, the process seems to still be occurring. After who-only-knows how many moons have been formed and crushed, Phobos and Deimos are all that remains, but Phobos is probably doomed to the same ultimate fate. Deimos, on the other hand, is probably safe. It’s a lot further away. Any planetary orbit also has a radius called a synchronous orbit. Around Earth, we know this as a geostationary orbit – the point at which an orbiting satellite will always be staring at the same part of Earth’s surface. But there’s an interesting ramification of synchronous orbits. They’re the most stable kind. Inside this point, an orbit is destined to eventually decay, while objects outside will gradually orbit further away due to centrifugal force, and may ultimately be lost altogether. Phobos sits, doomed, inside a synchronous orbit, while Deimos sits outside where it will eventually be free to leave. Similar situations in the past might explain why Phobos and Deimos are all that remains of the moon that once was. Assuming, of course, that this hypothesis is true. It’s very difficult to say, until we find an errant asteroid which happens to match the composition of the current Martian moons. Additionally, while a ring of dust and small objects has been predicted to exist between Phobos and Deimos, no evidence has ever been found for such a ring. Either way, the idea of a small, terrestrial planet like Mars having a ring system is rather pleasing! Heard via Gizmodo. Gif animation/video clip of Phobos eclipsing Deimos, as seen by NASA Curiosity. Photomanipulations created by @InvaderXan/supernovacondensate.net using • Comanche Outcrop observed by NASA Spirit, • Phobos observed by NASA MRO, • Deimos observed by NASA MRO, • Dione observed by NASA/ESA Cassini, and • Mars observed by ISRO Mangalyaan.
These games teach valuable skills and have a high fun and educational rating. Your child will practice investigation skills by scanning Dora's room for certain objects. Walking around her house, your child will play a variety of games such as dressing up Dora, helping her mother cook, and fetching her dog. Your child develops shape matching, letter recognition, and counting skills in the search for Gold clues. Your child will practice recognizing the capital and lower case letters of the alphabet as well as practicing phonics. Your child will learn to write letters of the alphabet and match them to sounds by tracing the letters with a mouse and choosing the objects that start with the letters. Your child develops spelling and letter recognition skills by helping Dora spell out simple words describing different pictures. Your child develops knowledge about the alphabet by watching these different videos and following along. Your child develops letter recognition and fine motor skills by helping Hoho collect coins that have the same letter as given by Kai-lan. Your child gains familiarity with the alphabet and its correct ordering by tapping words in alphabetical order. Your child uses the keyboard, practices the alphabet, and identifies objects that begin with a specific letter as he or she accompanies Dora through the forest. Your child will practice reciting alphabet letters and helping out Alpha Pig spell the word pumpkin.
Nothing can ruin a late-summer barbecue or fall outing more than having to swat at wasps. You might have run into one lately: its distinct long, yellow and black body, and its love of sugary drinks are two of the yellow jacket wasp’s hallmarks. The bug is also known for its painful sting — but did you know that it could also be deadly? It’s true – researchers have now figured out which type of yellow jacket is more likely to cause a lethal reaction than others. There are 17 species of yellow jackets, which are members of the wasp and hornet family Vespidae, throughout North America. The study that prompted this article looked at the two most common species in the eastern U.S. — Vespula maculifrons and Vespula germanica. The goal of the study, which was done by researchers at the Johns Hopkins Asthma and Allergy Center in Baltimore, was to see why some people had severe reactions when stung by a yellow jacket while others had a mild response or no reaction. They recruited 111 volunteers and put them through tests involving a total of 175 wasp stings over three years. The results showed that the Vespula maculifrons poses more of a danger, as its sting caused systemic reactions more often than the sting of the Vespula germanica did. More interestingly, 41% of the study participants who had suffered these kinds of reactions before had a reaction to the Vespula maculifrons sting, while only three percent of people who had not had such a response in the past experienced one during the study when stung by this particular yellow jacket. A “systemic reaction” occurs when the venom of the wasp causes problems beyond just reddening and pain around the area where the stinger went into the body. It basically means that the body is suffering an allergic response to the yellow jacket sting. Symptoms include lightheadedness/dizziness, itchiness, hives, nausea, stomach cramps, swelling of the tongue or throat, problems breathing, and fainting (due to a rapid dip in blood pressure). At its most severe, a systemic reaction is termed “anaphylaxis,” which can be fatal. If you have had an allergic reaction to a wasp sting in the past, see your doctor or allergist. There is immunization available that can help protect you. You should also be sure to carry an “EpiPen,” which is an autoinjector that can be used to treat anaphylactic shock. For all of us, even those who have never had a reaction to a yellow jacket sting (you might never have been stung by the Vespula maculifrons), it’s best to avoid areas around wasp nests. Note that the yellow jacket wasps are usually at their peak in the summer and fall months. If you are stung and start showing some symptoms of a severe systemic reaction, call 911 immediately.
This is an animated interactive that displays, on a Global Viewer, NOAA datasets on hazards, ocean, and climate. User can visualize data on phenomena such as hurricanes, humpback whale migrations, carbon tracker, sea ice extent, IPCC scenarios on global warming. In this activity for undergraduate students, learners build a highly simplified computer model of thermohaline circulation (THC) in the North Atlantic Ocean and conduct a set of simulation experiments to understand the complex dynamics inherent in this simple model. In this activity, students explore the increase in atmospheric carbon dioxide over the past 40 years with an interactive online model. They use the model and observations to estimate present emission rates and emission growth rates. The model is then used to estimate future levels of carbon dioxide using different future emission scenarios. These different scenarios are then linked by students to climate model predictions also used by the Intergovernmental Panel on Climate Change. This long classroom activity introduces students to a climate modeling software. Students visualize how temperature and snow coverage might change over the next 100 years. They run a 'climate simulation' to establish a baseline for comparison, do a 'experimental' simulation and compare the results. Students will then choose a region of their own interest to explore and compare the results with those documented in the IPCC impact reports. Students will gain a greater understanding and appreciation of the process and power of climate modeling. This set of animations and interactive simulations from the Byrd Polar Research Center at Ohio State University helps students develop an understanding of models used to understand the Earth System. Students consider the types of data that need to be included in a climate model, looking at inputs and outputs as well as variables, such as land surface, and how to measure changes of different parts of Earth's surface over time. C-Learn is a simplified version of the C-ROADS simulator. Its primary purpose is to help users understand the long-term climate effects (CO2 concentrations, global temperature, sea level rise) of various customized actions to reduce fossil fuel CO2 emissions, reduce deforestation, and grow more trees. Students can ask multiple, customized what-if questions and understand why the system reacts as it does. In this activity for undergraduates, students explore the CLIMAP (Climate: Long-Range Investigation, Mapping and Prediction) model results for differences between the modern and the Last Glacial Maximum (LGM) and discover the how climate and vegetation may have changed in different regions of the Earth based on scientific data. In this video, students see how data from the ice core record is used to help scientists predict the future of our climate. Video features ice cores extracted from the WAIS Divide, a research station on the West Antarctic Ice Sheet. This is a teaching activity in which students learn about the connection between CO2 emissionS, CO2 concentration, and average global temperatures. Through a simple online model, students learn about the relationship between these and learn about climate modeling while predicting temperature change over the 21st century.
/ GENTLE PRIMER / A Summary of Predefined Predicates The Predicates eq, ne, lt, le, ge, gt are used to compare values for equality. eq(X, Y)succeeds if X is equal to Y and fails otherwise. ne(X, Y)succeeds if X is not equal to Y and fails otherwise. These predicates work for all types including user-defined types, i.e. they may be used to compare terms. For example, eq(list(red, X), list(red, list(yellow,nil)))succeeds if X is list(yellow,nil). The predicates gt, ge, lt, and le are defined only for the types INT and STRING. gt(X, Y)succeeds if X is greater than Y and fails otherwise. gt(N, 0)succeeds if N is a positive number. In the case of strings, the lexicographical order is used for comparison. For example, gt("axy", "abc") gt("aaaa", "aa")succeed. Similarly, ge, lt, and le stand for ``greater or equal'', ``less than'', and ``less or equal'', respectively
Home > Flashcards > Print Preview The flashcards below were created by user on FreezingBlue Flashcards . What would you like to do? 2 kinds of symbolic logic: - 1. Simple (atomic) - 2. Compound (complex) - has no other part to it. - Ex: Columbia is the capital of S.C. - Statement that contains another statement as a component - Ex: The lights are on, the lights are off - In order to have a complex statement, you must be able to replace it with something that makes sense. Common compound propositions: Their parts are called: Conjuncts are connected together with the word: - Never the less - Ex: Andrew went swimming and Susan went hiking p, q, r, s..... Truth Functional Component Any component of a compound statement whose replacement by another statement having the same truth value would notchange the truth value of the compound statement Exclusive Sense of Disjunction: It is either one or the other, BUT not both are true Inclusive sense of disjunction - One or the other or both may be true - Ex: Getting a 3.8 gpa will get you on the deans list, or having a 3.9 will... Disjunctions "v" will only be false when: both p and q are false a compound statement with the form, "if p, then q" Antecedent in a conditional statement: the component that immediately follows the "if" Consequent in a conditional statement: component that immediately follows the "then" the relation that holds between the antecedent and the consequent of a conditional state. Whenever you have a true antecedent: the whole thing will be true If Combes was a rockstar he'd be famous Combes isnt a rockstar Therefore Combes isnt famous C (horseshoe) F This is nota good argument... refutation by counter example: - If obama were a rockstar hed be famous - Obama isnt a rockstar - Therefore obama is famous When youhave true premises and true conclusions True premises and False conclusion= - Symbolized by the horseshoe - p materially implies q - is true when either p is false, or q is trueq Refutation by logical analogy: exhibiting the fault of an argument by presenting another argument with the same form whose premises are known to be true and whose conclusion is known to be false The obama and combes example of being a rockstar A letter (lower case) for which a statement may be substituted Invalid argument form: argument form that has at least one substitution instance with true premises and a false conclusion Valid argument form argument form that has no substitution instances with true premises and a false con. a valid argument where one premise is a disjunction, another premise is is the denial of one of the two disjuncts, and the conclusion is the truth of the other disjunct. A valid argument that relies on a conditional premise, and another premise affirms the antecedent of that conditional, and the conclusion affirms its consequent Valid argument that relies on a conditional premise and another premise denies the consequent of that conditional, and the conclusion denies its antecedent Valid argument containing only conditional propositions. - p (horseshoe) q - q (horseshoe) r p (horseshoe) r Common invalid forms - 1. Fallacy of affirming the consequent - 2. Fallacy of denying the antecedent Fallacy of affirming the consequent: Fallacy in which the second premise of an argument affirms the consequent of a conditional premise and the conclusion of its argument affirms its antecedent. Fallacy of denying the antecedent: Fallacy in which the second premise of an argument denies the antecedent of a conditional premise and the conclusion of the argument denies its consequent Tautologous Statement form: A statement form that has only true substitution instances, a "tautology" Self-contradictory statement form: A statement form that has only false substituion instances, a "contradiction" Contingent Statement form: A statement form that has both true and false substitution instances - A tautological statement of the form: - [(p horseshoe q) horseshoe p] horseshoe p A truth funcvtional relation asserting that two statements connected by the three bar sign have the same truth values A compound statement that asserts that its two component statements imply one another and therefore are materially equivalent. two statements for which the statement of their material equivalence is a tautology; they are equivalent in meaning and can replace one another. An expression of logical equivalence between a symbol and the negation of the negation of that symbol. De Morgan's Theorems - 1. the negation of the disjunction of two statements is logically equivalent to the conjunction ofthe negations of the two disjuncts - 2. The negation of the conjunction of two statements is logically equivalent to the disjunction of the negations of the two conjuncts p (horseshoe) q is logically equivalent to: - p v q The three laws of thought: - 1. principle of identity - 2. principle of noncontradiction - 3. principle of excluded middle Principle of identity: if any statement is true, it is true Principle of Noncontradiction: - No statement can be both true and false - Every state. of the form p dot -p must be false. that every such state. is self contradictory Principle of excluded middle: - Every state. is either true or false - Every state. of the form p v -p must be true - That every such state. is a tautology What would you like to do? 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The term “indigenous peoples” refers to the first humans who established a permanent life in a particular region or area of the world. Indigenous peoples may also be referred to as aboriginal peoples, first peoples, or native peoples. Every inhabitable area in the world has a specific group of indigenous peoples. These individuals may live in permanent settlements or prefer a nomadic lifestyle, in which they move from place to place within a particular territory. The vast majority of indigenous peoples and their lands have been colonized throughout history, primarily by European nations. Today, in the post-colonial era, these regions have become independent countries, and the governments of these countries typically decide which indigenous groups to recognize and define which individuals may consider themselves indigenous. This practice has resulted in the marginalization of many indigenous peoples, losing their identities, traditions, and autonomy. Indigenous groups that are recognized by ruling governments are generally not proportionally represented within the government. Some indigenous peoples around the world, however, have remained free of colonization. Most of these groups are considered uncontacted due to their isolated locations. Indigenous Peoples Around the World Each of the five major regions of the world - Oceania, the Americas, Africa, Asia, and Europe - have a population of indigenous peoples. One of the largest groups of indigenous peoples in Oceania are the Aboriginal Australians. These individuals belong to a number of different tribes, all of which have been subjected to exclusionary tactics by the government of Australia throughout history. Many islands throughout this region also have significant indigenous populations. In some cases, these islands have achieved independence from colonial powers and are now governed by the first peoples. The indigenous peoples of the Americas have likely suffered greater population losses during its colonial era than other regions of the world. In some American countries, indigenous peoples make up a very small percentage of the population, while indigenous peoples are the majority in other nations. For example, the indigenous population of Bolivia makes up an estimated 56% to 70% of the nation's total population. Although the vast majority of residents throughout Africa can be considered indigenous, self-identification as such is limited. In fact, indigenous identity is more commonly related to the lifestyles and customs of a particular group of individuals, specifically those who have less representation in government. Many of these individuals live nomadic lifestyles. Asia covers one of the largest areas of the Earth’s surface. Additionally, the continent is home to the largest indigenous population in the world, currently estimated at 70% of total population, and can be found throughout the continent. Some of the largest concentrations of indigenous peoples are found in India and Indonesia. Europe has one of the smallest populations of indigenous peoples in the world. These individuals are concentrated in the northern and eastern regions of this continent. Some of the indigenous peoples of Europe (and their regions of origin) include: the Sami (Scandinavia), Circassians (Russia and Caucasus), Basques (Spain and France), and Crimean Tatars (Crimea).
Guest Post By: Grace Derocha, registered dietitian, certified diabetes educator and certified health coach with Blue Cross Blue Shield of Michigan School cafeterias give children the opportunity to become independent eaters at an early age. While it’s a great way to try new foods, it also means that parents are unable to control what and how much a child consumes. Thankfully, USDA’s regulations assist children in making better decisions by requiring cafeterias to offer more fruit, vegetables and whole grains while limiting sodium, calories and unhealthy fats. However, it’s still important to educate young children on nutrition and how to make healthy decisions on their own. - Talk it Out: Explain to your child that a balanced diet filled with fruits and vegetables is vital to well-being. Have an age-appropriate discussion on the importance of nutrition and how their food choices impact how they feel throughout the day. Explain that a healthy lunch will give him or her more energy to play at recess and do well in class. - Prepare for the Week: Review the school lunch menu with your child each week and discuss which foods and drinks are healthy, so they will know what to choose when purchasing lunch. For more information on the school meal program, check with the cafeteria manager or on the school’s website. Many districts include a page listing of ingredients, nutritional facts, allergen information and more. - Set an Example: The daily influence of a parent is more impactful than many people realize. Studies have shown that young children’s food preferences are significantly influenced by what mothers liked, disliked and even those she had never tasted. The more excitement parents express about fruits and vegetables, the more likely their children will want to eat them, too. - Plan a Lunch Date: The School Nutrition Association recommends parents have lunch with their child in the school cafeteria. This special one-on-one time allows moms and dads to spend extra time with their child, and encourage healthy food choices. Check with the principal or cafeteria manager first regarding visitor policies. - Build Healthy Habits: Kids who eat with their families are less likely to snack on unhealthy foods and more likely to eat fruits, vegetables and whole grains. Although it can be challenging with busy schedules, family mealtime is key to developing healthy habits. Also, lessen the temptation to reach for processed after-school snacks by keeping fresh fruit and vegetables pre-washed, cut up and available for easy consumption. - Make it Fun: Healthy eating habits should be introduced and reinforced in creative and playful ways. For example, make a game out of consuming colorful fruits and vegetables daily. Encourage everyone in the family to “Eat the rainbow” by consuming red, orange, yellow, green, blue or purple and white or brown produce daily to win. After school, discuss who ate the most colorful lunch. Think of a fun prize for the family member who has the most wins at the end of the week or month. The United States Department of Agriculture Choose My Plate website is a great resource for games and activities that encourage healthy choices in a positive way that kids can understand. Grace Derocha is a registered dietitian, certified diabetes educator and certified health coach with Blue Cross Blue Shield of Michigan. For more tips on how to live a healthier lifestyle, visit AHealthierMichigan.org. Healthy recipe ideas:
In central Laos, thousands of large stone jars carved from solid rock have mystified archaeologists. For decades, the question was “What were these jars used for?” That question might be answered with the recent excavations on the Plain of Jars. Archaeologists have discovered 2,500-year-old human remains buried at sites near to the clusters of stone jars. This discovery suggests that the jars might have been used to “distill” the bodies before burial. The pits where the bones were buried had been covered with a large limestone block. In other cases, the bones had been placed in ceramic vessels before being buried. (Plain of Jars) Despite being named a “plain” of jars, the landscape is actually a collection of lowland slopes and valleys in Xieng Khouang. Measuring between three and ten feet tall, the jars themselves are hewed from sandstone and limestone. The jars located on the Xieng Khouang plateau date from 500 BC to 500 AD. The stone seems to have been quarried from several areas in the Xieng Kouang foothills, then spread across more than 90 sites, some of which had just a handful of jars while others had hundreds. The largest location has about 400 stone vessels. Each jar has a cylindrical shape with the bottom wider than the top and most have lip rims, which suggest that the jars had originally had lids. Few, lids, however, have ever been found at the sites. A single jar has been found decorated with a human “frogman” relief carved on the exterior. (Plain of Jars – Site One) The archaeologist leading the work at the Plain of Jars, Dr Dougald O’Reilly , was the one to suggest the theory that the jars were used to decompose the bodies before the bones were removed and reburied. The archaeologists are not only trying to figure out the purpose of the jars but about the people and culture who made them. Dr O’Reilly said, “What is now clear is that these are mortuary and were used for the disposal of the dead. This will be the first major effort since the 1930s to attempt to understand the purpose of the jars and who created them. One theory is that they were used to decompose the bodies. Later, after the flesh was removed, the remains may have been buried around the jars.” (Hmong Girls climbing on one of the jars at Site) Other theories for the purpose of the jars include their being used as storage vessels or to hold the cremated remains of the dead. These theories have been supported by the various findings in the vessels – cremated fragments of bones and teeth, and glass beads. The vessels that do remain have not only yielded bones and trinkets, but their existence suggests that the culture which used them had a multiple-step funeral process, according to Dr O’Reilly. “Our excavations have also revealed, for the first time at one of these sites, a primary burial, where a body was placed in a grave.” (Location of Plain of Jars and Xieng Khouang plain -blue shading-) Dr O’Reilly also said that one of the many goals of the archaeologists is to determine the status of the buried individuals. That task, however, is difficult due to the lack of material objects buried with them. Nevertheless, Dr O’Reilly and his team hope that further analysis of the various graves will provide some clues. “This will open up a huge amount of information into who these people were,” he said, determinedly optimistic. Unfortunately, many of the sites have been unreachable to researchers due to the danger of the unexploded bombs that were dropped on the area by the United States during the Vietnam War. Although many jars are relatively intact today, it is feared that many jars – and their contents – were destroyed by the bombs that did detonate.
A new species of carnivorous dinosaur — one of the three largest ever discovered in North America — lived alongside and competed with small-bodied tyrannosaurs 98 million years ago. This newly discovered species, Siats meekerorum, (pronounced see-atch) was the apex predator of its time, and kept tyrannosaurs from assuming top predator roles for millions of years. Named after a cannibalistic man-eating monster from Ute tribal legend, Siats is a species of carcharodontosaur, a group of giant meat-eaters that includes some of the largest predatory dinosaurs ever discovered. The only other carcharodontosaur known from North America is Acrocanthosaurus, which roamed eastern North America more than 10 million years earlier. Siats is only the second carcharodontosaur ever discovered in North America; Acrocanthosaurus, discovered in 1950, was the first. “It’s been 63 years since a predator of this size has been named from North America,” says Lindsay Zanno, a North Carolina State University paleontologist with a joint appointment at the North Carolina Museum of Natural Sciences, and lead author of a Nature Communications paper describing the find. “You can’t imagine how thrilled we were to see the bones of this behemoth poking out of the hillside.” Zanno and colleague Peter Makovicky, from Chicago’s Field Museum of Natural History, discovered the partial skeleton of the new predator in Utah’s Cedar Mountain Formation in 2008. The species name acknowledges the Meeker family for its support of early career paleontologists at the Field Museum, including Zanno. The recovered specimen belonged to an individual that would have been more than 30 feet long and weighed at least four tons. Despite its giant size, these bones are from a juvenile. Zanno and Makovicky theorize that an adult Siats might have reached the size of Acrocanthosaurus, meaning the two species vie for the second largest predator ever discovered in North America. Tyrannosaurus rex, which holds first place, came along 30 million years later and weighed in at more than twice that amount. Although Siats and Acrocanthosaurus are both carcharodontosaurs, they belong to different sub-groups. Siats is a member of Neovenatoridae, a more slender-bodied group of carcharodontosaurs. Neovenatorids have been found in Europe, South America, China, Japan and Australia. However, this is the first time a neovenatorid has ever been found in North America. Siats terrorized what is now Utah during the Late Cretaceous period (100 million years ago to 66 million years ago). It was previously unknown who the top meat-eater was in North America during this period. “Carcharodontosaurs reigned for much longer in North America than we expected,” says Zanno. In fact, Siats fills a gap of more than 30 million years in the fossil record, during which time the top predator role changed hands from carcharodontosaurs in the Early Cretaceous to tyrannosaurs in the Late Cretaceous. The lack of fossils left paleontologists unsure about when this change happened and if tyrannosaurs outcompeted carcharodontosaurs, or were simply able to assume apex predator roles following carcharodontosaur extinction. It is now clear that Siats’ large size would have prevented smaller tyrannosaurs from taking their place atop the food chain. “The huge size difference certainly suggests that tyrannosaurs were held in check by carcharodontosaurs, and only evolved into enormous apex predators after the carcharodontosaurs disappeared,” says Makovicky. Zanno adds, “Contemporary tyrannosaurs would have been no more than a nuisance to Siats, like jackals at a lion kill. It wasn’t until carcharodontosaurs bowed out that the stage could be set for the evolution of T. rex.” At the time Siats reigned, the landscape was lush, with abundant vegetation and water supporting a variety of plant-eating dinosaurs, turtles, crocodiles, and giant lungfish. Other predators inhabited this ecosystem, including early tyrannosaurs and several species of other feathered dinosaurs that have yet to be described by the team. “We have made more exciting discoveries including two new species of dinosaur,” Makovicky says. “Stay tuned,” adds Zanno. “There are a lot more cool critters where Siats came from.” All fieldwork was conducted under permits through the Bureau of Land Management and funded by the Field Museum. Research was funded by North Carolina State University, North Carolina Museum of Natural Sciences and the Field Museum. Note : The above story is based on materials provided by North Carolina State University.
Polymers & polymerization Published on: Mar 4, 2016 Transcripts - Polymers & polymerization Name: Vijay Kumar Types of polymerization A word polymer is a combination of two Greek words, “Poly” means “many” and “Mer” meaning “ part or unit”. A polymer is a large molecule of which is formed by repeated linking of the small molecules called More monomer molecules joined in units of long polymer. Classification Based On Source. Classification Based On Structure. Classification Based On Polymerisation. Classification Based On Molecular Force. 1. natural polymers:- The definition of a natural polymer is a polymer that results from only raw materials that are found in nature. Example:- proteins, cellulose, starch, rubber. 2. semi-synthesis polymers:- Cellulose derivatives as cellulose acetate (rayon) and cellulose nitrate etc. are the usual examples. 3. synthesis polymers:- A variety of synthetic polymers as plastic synthetic fibers are examples of manmade polymers. Example:- Buna-s, buna-r, nylon, polythene, polyester. 1. Linear polymers:- Consist of long and straight chains. Example:- pvc 2. Branched chain polymers:- contain linear chains having some branches, e.g., low 3. Cross linked chain polymers:- formed from bi-functional and tri-functional monomers and contain strong covalent bonds e.g. bakelite, melamine. Linear Branched Cross-linked 1. Addition polymers:- Formed by the repeated addition of monomer molecules possessing double or triple bonds. n(CH2=CH2) -(CH2 -CH2 )- 2. Condensation polymers:- Formed by repeated condensation reaction between two different bi-functional or tri-functional monomeric units. Example: Terylene (dacron), nylon 6, 6, nylon 6. n(H2N(CH2)6 NH2) + n(HOOC(CH2)4COOH) [-NH(CH2)6NHCO(CH2)4CO-]n + nH2O 1. Elastomers :- These are rubber-like solids with elastic properties. The polymer chains are held together by the weakest intermolecular forces. A few cross links are introduced in between the chains, which help the polymer to retract to its original position after the forces is released as in vulcanized example: Buna-S, Buna-N, Neoprene etc. 2. THERMOPLASTIC POLYMERS:- These are linear or slightly branched long chain polymers, which can be softened on heating & reversibly hardened on cooling repeatedly. Their hardness is a temporary property & varies with temperature. EXAMPLE:- POLYVINYL CHLORIDE. POLYVINYL CHLORIDE:- It is a vinyl polymer constructed of repeating vinyl groups (Ethenyls) having one of their hydrogens replaced with a 3. THERMOSETTING POLYMERS:- Initial mixture of reactive, low molar mass compounds reacts upon heating in the mold to form an insoluble, infusible network. BAKELITE: Bakelite is formed of phenol and form-aldehyde polymerization. 1. Addition polymerization:- The polymer is formed from the monomer, without the loss of any material, and the product is the exact multiple of the original monomeric molecule. Addition polymerization proceeds by the initial formation of some reactive species such as free radicals or ions and by the addition of the reactive species to the other molecule, with the regeneration of the reactive feature. 1. Free radical mechanism:- Alkenes or dienes and their derivatives are polymerized in the presence of a free radical generating initiator (catalyst) like benzoyl peroxide, acetyl peroxide, t-bu peroxide, etc. This process involves three steps:- a) Chain initiation step - addition of phenyl free radical formed by the peroxide to the ethene double bond ,thereby forming a larger radical. b) Chain propagation step - Repetition of this sequence with new and bigger radicals. c) Chain terminating step - The product radical thus formed reacts with another radical to form the Process in which two monomers react to form a larger molecule and eliminate a smaller molecule (usually water, ammonia, methanol or It also called as step-growth polymerization. EXAMPLE:- 1. POLYAMIDE:- NYLON 6-6, NYLON 6. 2. POLYESTER:- TERILIN 3. BAKELITE POLYMER 4. MALEMIN POLYMER Characteristics of polymer Low coefficient of friction. Good corrosion resistance. Good mould ability. Excellent surface finish can be obtained. Can be produced with close dimensional tolerances. Poor tensile strength. Low mechanical properties. Poor temperature resistance. Can be produced transparent or in different colours. Application of polymers 1. Medicine:- Many biomaterials, especially heart valve replacements and blood vessels, are made of polymers like Dacron, Teflon and 2. Consumer Science :- Plastic containers of all shapes and sizes are light weight and economically less expensive than the more traditional containers. Clothing, floor coverings, garbage disposal bags, and packaging are other polymer applications. 3. Industry:- Automobile parts, windshields for fighter planes, pipes, tanks, packing materials, insulation, wood substitutes, adhesives, matrix for composites, and elastomers are all polymer applications used in the 4. Sports:- Playground equipment, various balls, golf clubs, swimming pools, and protective helmets are often produced from polymers.
What is Style and Voice in Writing? Style means the mechanical or technical aspects of writing and may be specific to the requirements of the subject or topic. Voice means the unique worldview and word choices of the author. Tone means the attitude conveyed in the writing and may encompass formality, objectivity, intimacy, and similar aspects.. What are the different voices in writing? Types of Voice Author’s Voice – Author’s voice is the writer’s particular style, which he employs in a particular story, or piece of writing. Character’s Voice – A character’s voice is the voice of the main character, how he views the world. … Here, the author uses a conscious person as a narrator in the story. What are the three types of narration? We must also choose how to convey the topic to the reader. In a moment, we’ll work through three types of narration: first person, second person, and third person. Each serves its own purpose. But, before we enjoy some examples of narration, it’s important to distinguish between a narrative and narration. What are the five elements of voice? Page 1There are five elements of voice: diction, detail, imagery, syntax, tone.Diction is the foundation of voice and contributes to all of its elements.DETAIL.Imagery – verbal representation of sensory experience.Syntax – the way words are arranged within sentences. What makes writing unique? An author’s writing style, on the other hand, is the unique way they use words to capture their work on the page. A writer’s style often manifests in their tone, word choice and sentence structure, figurative language, sensory details, and other such elements of prose. What is a voice in a story? What Is the Definition of Voice in Writing? In literature, “voice” refers to the rhetorical mixture of vocabulary, tone, point of view, and syntax that makes phrases, sentences, and paragraphs flow in a particular manner. Novels can represent multiple voices: that of the narrator and those of individual characters.
The Americans with Disabilities Act (ADA) became law in 1990. The ADA is a civil rights law that prohibits discrimination against individuals with disabilities in all areas of public life, including jobs, schools, transportation, and all public and private places that are open to the general public. The purpose of the law is to make sure that people with disabilities have the same rights and opportunities as everyone else. The ADA gives civil rights protections to individuals with disabilities similar to those provided to individuals on the basis of race, color, sex, national origin, age, and religion. It guarantees equal opportunity for individuals with disabilities in public accommodations, employment, transportation, state and local government services, and telecommunications. The ADA is divided into five titles (or sections) that relate to different areas of public life. In 2008, the Americans with Disabilities Act Amendments Act (ADAAA) was signed into law and became effective on January 1, 2009. The ADAAA made a number of significant changes to the definition of “disability.” The changes in the definition of disability in the ADAAA apply to all titles of the ADA, including Title I (employment practices of private employers with 15 or more employees, state and local governments, employment agencies, labor unions, agents of the employer and joint management labor committees); Title II (programs and activities of state and local government entities); and Title III (private entities that are considered places of public accommodation). More About the ADA Title I (Employment) Equal Employment Opportunity for Individuals with Disabilities This title is designed to help people with disabilities access the same employment opportunities and benefits available to people without disabilities. Employers must provide reasonable accommodations to qualified applicants or employees. A reasonable accommodation is any modification or adjustment to a job or the work environment that will enable an applicant or employee with a disability to participate in the application process or to perform essential job functions. This portion of the law is regulated and enforced by the U.S. Equal Employment Opportunity Commission. Employers with 15 or more employees must comply with this law. The regulations for Title I define disability, establish guidelines for the reasonable accommodation process, address medical examinations and inquiries, and define “direct threat” when there is significant risk of substantial harm to the health or safety of the individual employee with a disability or others. Title II (State and Local Government) Nondiscrimination on the Basis of Disability in State and Local Government Services Title II of the ADA prohibits discrimination against qualified individuals with disabilities in all programs, activities, and services of public entities. It applies to all state and local governments, their departments and agencies, and any other instrumentalities or special purpose districts of state or local governments. It clarifies the requirements of section 504 of the Rehabilitation Act of 1973, as amended, for public transportation systems that receive federal financial assistance, and extends coverage to all public entities that provide public transportation, whether or not they receive federal financial assistance. It establishes detailed standards for the operation of public transit systems, including commuter and intercity rail (e.g., AMTRAK). This title outlines the administrative processes to be followed, including requirements for self-evaluation and planning; requirements for making reasonable modifications to policies, practices, and procedures where necessary to avoid discrimination; architectural barriers to be identified; and the need for effective communication with people with hearing, vision and speech disabilities. This title is regulated and enforced by the U.S. Department of Justice. Title III (Public Accommodations) Nondiscrimination on the Basis of Disability by Public Accommodations and in Commercial Facilities This title prohibits private places of public accommodation from discriminating against individuals with disabilities. Examples of public accommodations include privately-owned, leased or operated facilities like hotels, restaurants, retail merchants, doctor’s offices, golf courses, private schools, day care centers, health clubs, sports stadiums, movie theaters, and so on. This title sets the minimum standards for accessibility for alterations and new construction of facilities. It also requires public accommodations to remove barriers in existing buildings where it is easy to do so without much difficulty or expense. This title directs businesses to make "reasonable modifications" to their usual ways of doing things when serving people with disabilities. It also requires that they take steps necessary to communicate effectively with customers with vision, hearing, and speech disabilities. This title is regulated and enforced by the U.S. Department of Justice. Title IV (Telecommunications) This title requires telephone and Internet companies to provide a nationwide system of interstate and intrastate telecommunications relay services that allows individuals with hearing and speech disabilities to communicate over the telephone. This title also requires closed captioning of federally funded public service announcements. This title is regulated by the Federal Communication Commission. Title V (Miscellaneous Provisions) The final title contains a variety of provisions relating to the ADA as a whole, including its relationship to other laws, state immunity, its impact on insurance providers and benefits, prohibition against retaliation and coercion, illegal use of drugs, and attorney’s fees. This title also provides a list of certain conditions that are not to be considered as disabilities. Future ADA Issues What Barriers Still Exist For People With Disabilities? [Captioned Video -- 1:10 min.] Disability and Our Aging Population [Captioned Video -- 1:42 min.] Changes in Technology 2 [Captioned Video -- 1:11 min.]
SBU Study Shows Kelp Can Reduce Ocean Acidification and Protect Bivalves One of the most serious climate change-related threats to shellfish is caused by increasing levels of carbon dioxide (CO2) in the Earth’s atmosphere. As CO2 makes its way into the oceans, chemical reactions occur that lower pH and create ocean acidification. For the past two decades, climate change research has shown that rising CO2 levels in surface waters threaten shellfish that require higher-pH waters to grow and survive — an alarming discovery in coastal zones where additional sources of acidity can further reduce pH and slow certain species’ shell formation. But researchers at Stony Brook may have discovered a solution to this problem just beneath the waves in a common sea plant — kelp. A Stony Brook University-led study titled “Kelp (Saccharina latissima) Mitigates Coastal Ocean Acidification and Increases the Growth of North Atlantic Bivalves in Lab Experiments and on an Oyster Farm,” reveals that harvesting kelp may be a new way to help keep bivalves such as clams and oysters healthy and more abundant. The study, led by Christopher Gobler, endowed chair of coastal ecology and conservation at Stony Brook’s School of Marine and Atmospheric Sciences (SoMAS), and colleagues was published in the journal Frontiers in Marine Science. Gobler and his team conducted six experiments to assess the effects of elevated CO2 and the presence of kelp on the growth rates of three different bivalve species: Eastern oysters, blue mussels and hard clams. In each of the experiments, kelp cultivation significantly reduced acidification. The research was supplemented with a field experiment at Great Gun Oysters aquaculture farm in East Moriches, New York. “When people think about climate change, they’re most apt to think the weather is getting warmer, temperature is getting hotter, and that there are more heat waves, but a less well-known symptom of climate change has to do with our oceans,” said Gobler. The study demonstrated that the deployment of kelp on an oyster farm combats ocean acidification and therefore helps protect bivalves. The process may also have additional ecosystem and aquaculture benefits, including the sequestration and extraction of carbon and nitrogen, and protection against harmful algae blooms. Gobler said acidification is detrimental to coral reefs and different types of algae, as well as species that need calcium carbonate to make their shells, including bivalves. “This also affects lobsters and crabs,” said Gobler. “Making shells becomes more and more difficult as the levels of CO2 increase in our atmosphere and in our oceans.” The research team found that during a one-month deployment, oysters that were surrounded by kelp enjoyed higher-pH water and grew significantly faster than individual shellfish located farther away where the pH of the water was lower. Mike Doall, associate director for bivalve restoration at SoMAS and a member of the research team, said kelp can be a beneficial and profitable option for oyster farmers. “I’m an oyster farmer, and I started thinking about kelp 10 years ago when I was looking for ways to diversify my business,” said Doall. “I met somebody who was growing kelp in Maine and my first reaction was one of surprise. I had no idea why they were growing it or what they were going to do with it. But the more I looked into it and the more I researched it, I began to realize that this is the perfect companion product of oysters.” Doall explained that kelp has an opposite growing season from oysters. Specifically, farmers can divert resources from oysters in the warm months to kelp in the colder months. What’s more, kelp can be integrated vertically with oysters and other shellfish, which means that farmers can diversify without having to replace one crop for another out in the ocean. Overall, the research clearly shows that the cultivation of kelp constitutes an environmentally friendly means of protecting shellfisheries against present and future ocean acidification and other coastal stressors. “We’ve helped grow kelp on 10 oyster farms across New York since 2018, and more and more aquaculturists have been hoping to incorporate kelp into their farms,” said Doall. “In addition to providing crop diversification and additive revenue streams, the ability of kelp to fight ocean acidification gives these oyster farmers one more reason to add kelp as a second crop.” Doall described kelp and seaweeds as “unlike anything else you can grow on land and water.” “There are zero inputs,” he said. “You don’t have to fertilize them. You don’t have to feed them. They don’t require pesticides or insecticides. They suck up carbon dioxide, and they also suck up nitrogen, which is one of the major water-quality problems facing Long Island and other coastal areas. The result is a net extraction from the environment. So there are a lot of really good environmental and economic reasons to grow kelp.” The recent study builds on previous research by the same SoMAS group demonstrating that kelp has the ability to deter the intensity of harmful algal blooms, another environmental threat to shellfish aquaculture. That study was published in the journal Harmful Algae in 2021. Both Gobler and Doall said the findings could have powerful implications for oyster farming in coastal zones on Long Island and around the world. “We have been witnessing coastal ocean acidification for years and have documented its ability to slow the growth of, and even kill off, shellfish,” said Gobler. “We began growing kelp on oyster farms to simply expand aquaculture regionally. After seeing its ability to rapidly take up CO2 and improve low pH conditions, we knew it had the potential to benefit shellfish experiencing acidification. And while showing that in the lab was exciting, being able to improve the growth of oysters on an oyster farm experiencing coastal acidification proves this approach can have very broad applications.” — Robert Emproto Read story on SBU News
Aluminum is a light metal with low density (2.79g/cm3), its chemical symbol is Al, and its atomic number is 13. Pure aluminum has low strength but good plasticity. Galvanized steel refers to the ordinary carbon construction steel that is galvanized to effectively prevent corrosion and rust of the steel, thereby prolonging the service life of the steel. The galvanizing is divided into electro-galvanized and hot-dip galvanized. According to the aluminum content, pure aluminum can be divided into: - High purity aluminum: ≥99.999℅ - Industrial refined aluminum: 99.95℅～99.996℅ - Industrial pure aluminum: 99.00℅～99.85℅ Hot-dip galvanized steel, electro-galvanized steel, single-sided or double-sided differential thickness galvanized steel, alloy composite galvanized steel, color galvanized steel, printing coated galvanized steel, polyvinyl chloride laminated galvanized steel, etc. The strength of pure aluminum is very low. And steel is an alloy of iron and is known for its strength. The strength of galvanized steel is stronger than aluminum. The density of aluminum is small, only 2.7 times that of water. The specific strength of aluminum (the ratio of strength to weight) is high, and the mechanical strength of some high-strength aluminum alloys exceeds that of structural steel. Aluminum has no magnetism, and aluminum at low temperatures (-198 ℃) will not be brittle and still have good mechanical properties. Aluminum can be rolled into thin plates and foils, drawn into filaments, and extruded into various complex shapes. Its ductility is very good. Aluminum can quickly combine with oxygen in the air to form a dense and hard aluminum oxide film. With a thickness of 0.005 to 0.02 microns, it becomes a natural protective layer of aluminum and prevents aluminum from being oxidized. Therefore, it has good corrosion resistance. Aluminum has good electrical and thermal conductivity. The electrical conductivity is equivalent to 64.94% of the international standard annealed copper, which is about half of silver. Aluminum has strong reflective properties, reflecting ultraviolet rays stronger than silver, and aluminum does not produce sparks when hit. Galvanized steel has the advantages of alkali resistance, good impact resistance, fast heat transfer, long mechanical life, good flame retardancy, natural degradation, and recycling value. Galvanized steel sheet is also very convenient to use and can be directly welded. The galvanized steel surface is very smooth and clean, so it can avoid the descaling work again during use. The accuracy of the size of the galvanized products is very high, the products are straight and the plate shape is good. The strength is great, and the use safety is high. Because of its excellent physical properties, aluminum has been widely used in various sectors of the national economy and defense industry. As a lightweight structural material, aluminum is light in weight and strong. Land, sea, and air vehicles, especially aircraft, missiles, rockets, satellites, etc., use a large amount of aluminum. A supersonic aircraft uses aluminum. 70% of its own weight, and the amount of aluminum used in missile accounts for more than 10% of its total weight. In the construction industry, aluminum alloy is used as the door, window, and structural material of the house, and the solar collector is made of aluminum, which can save energy. In terms of power transmission, aluminum is the first to use, and 90% of high-voltage electrical wires are made of aluminum. In the food industry, most of the storage tanks, cans, and beverage containers are made of aluminum. In other aspects, aluminum powder is used as a reducing agent for refractory metals (such as molybdenum, etc.) and as a deoxidizer in the steelmaking process, as well as pots, basins, spoons, etc. in daily life. Galvanized steel has a wide range of uses. A large amount of galvanized steel is used in automobile manufacturing, refrigerated containers, construction, ventilation and heating facilities, and furniture manufacturing. Aluminum is expensive, but it is favored for its light and strong characteristics, which can help reduce transportation costs. Although the corrosion resistance of aluminum is not as strong as that of galvanized steel, it is still a good choice compared with other materials. Compared with aluminum, galvanized steel has the advantages of low processing cost, durability, and high corrosion resistance. Each of the materials has its own advantages.
source : allnswers.com How would an increase in nest sites affect a population of pigeons? athe population would decrease. bthe population would increase. The correct answer is B. If there was an increase in nest sites, the pigeon population would increase. This would of course be due to the greater amount of space in which the pigeons could breed and raise their offspring. Hopefully that’s answered the question for you. Factors that affect population size and growth – Economics Help – Population growth is determined by fertility rates (the number of children per adult) – fatality rates. Birth rates and mortality rates are, in turn, determined by a combination of factors. Often economic growth and economic development have led to a decline in population growth, but there are no hard and fast…How would an increase in nest sites affect a population of pigeons? A biologist counts the number of rabbits in a population each year and observes a decrease in population. Since the coyote population has exploded, the biologist concludes that the coyote population has had a negative…the population would increase. Enter another question to find a notecard SOLUTION: help me 1 hour help me – Studypool – Thus, if a population has a growth rate of 2%, and it remains 2% as the population gets bigger, it's growing exponentially. This graphic not only shows the classic upward-curving shape of the exponential growth curve, but also how it contrasts with growth that is linear, i.e. in a straight line.That doesn't automatically mean an increase in world population occurred. In fact, the early industrial revolution saw However, if a population is increasing, but cities can't meet the increased demand of limiting factors such as food How did the Second Industrial Revolution affect American society?The list of environmental problems also includes growth of population, shortage of food and fresh water in some parts of the world, destruction of wildlife and many others. A lot of them are man-made. How Would An Increase In Nest Sites Affect A Population Of… – Pigeon squab 16 days Juvenile pigeons in nest Juvenile pigeons in nest. Juvenile pigeon with mother Fledged juvenile pigeon Fledged juvenile pigeon. Images of pigeons were first found on the reconstructed façade of an excavated temple dedicated to the goddess Ninhursag (Queen of Heaven…Passenger Pigeons seemed to have evolved a survival strategy based on predator satiation. The birds nested in the northern forests each spring and In a large colony, hundreds of millions of squabs littered the forest floor helpless to their many predators. But the local populations of foxes, wolves…CThe population would remain almost the same. DThe population would be reduced the next year. The correct answer is B. If there was an increase in nest sites, the pigeon population would increase. This would of course be due to the greater amount of space in which the pigeons could…
NASA's Great Observatories Provide a Detailed View of Kepler's Supernova Remnant NASA's three Great Observatories -- the Hubble Space Telescope, the Spitzer Space Telescope, and the Chandra X-ray Observatory -- joined forces to probe the expanding remains of a supernova. Now known as Kepler's supernova remnant, this object was first seen 400 years ago by sky watchers, including famous astronomer Johannes Kepler. The combined image unveils a bubble-shaped shroud of gas and dust that is 14 light years wide and is expanding at 4 million miles per hour (2,000 kilometers per second). Observations from each telescope highlight distinct features of the supernova remnant, a fast-moving shell of iron-rich material from the exploded star, surrounded by an expanding shock wave that is sweeping up interstellar gas and dust. Each color in this image represents a different region of the electromagnetic spectrum, from X-rays to infrared light. These diverse colors are shown in the panel of photographs below the composite image. The X-ray and infrared data cannot be seen with the human eye. By color-coding those data and combining them with Hubble's visible-light view, astronomers are presenting a more complete picture of the supernova remnant. Visible-light images from the Hubble telescope (colored yellow) reveal where the supernova shock wave is slamming into the densest regions of surrounding gas. The bright glowing knots are dense clumps from instabilities that form behind the shock wave. The Hubble data also show thin filaments of gas that look like rippled sheets seen edge-on. These filaments reveal where the shock wave is encountering lower-density, more uniform interstellar material. The Spitzer telescope shows microscopic dust particles (colored red) that have been heated by the supernova shock wave. The dust re-radiates the shock wave's energy as infrared light. The Spitzer data are brightest in the regions surrounding those seen in detail by the Hubble telescope. The Chandra X-ray data show regions of very hot gas, and extremely high energy particles. The hottest gas (higher-energy X-rays, colored blue) is located primarily in the regions directly behind the shock front. These regions also show up in the Hubble observations, and also align with the faint rim of glowing material seen in the Spitzer data. The X-rays from the region on the lower left (blue) may be dominated by extremely high energy electrons that were produced by the shock wave and are radiating at radio through X-ray wavelengths as they spiral in the intensified magnetic field behind the shock front. Cooler X-ray gas (lower-energy X-rays, colored green) resides in a thick interior shell and marks the location of heated material expelled from the exploded star. The remnant of Kepler's supernova, the last such object seen to explode in our Milky Way galaxy (with the possible exception of the Cassiopeia A supernova, for which ambiguous sightings were reported around 1680), is located about 13,000 light years away in the constellation Ophiuchus. The Chandra observations were taken in June 2000, the Hubble in August 2003, and the Spitzer in August 2004.
Cryptography – RSA Algorithm Simplified With Example RSA is probably the most commonly used secure cryptographic algorithm. The acronym RSA comes from the surnames of Ron Rivest, Adi Shamir and Leonard Adleman, who publicly described the algorithm in 1977. It’s usage is undeniably the greatest for secure data transmission. What is RSA algorithm ? RSA is an asymmetric cryptographic algorithm, widely used to the purpose of secure data transmission. The asymmetric cryptography means that there will be two different keys, one private and other public, linked via some mathematical function. It is also called a public key algorithm. The public key is meant to be spread over public users and private key is kept at secure location where no one else can access. Basic working of RSA We can take simple browser request for example. Let us consider we are using RSA for performing some request on server. The basic steps that is executed behind the scenes are as follows: - The browser sends it’s public key to the server and requests for some service. Let’s say, browser is asking for some data. - The server receives the request, generates data, encrypts it with browser’s public key and returns encrypted data as response. - The browser receives encrypted data, decrypts it and uses it as required. Alright, that’s was the basic working. Let’s see the algorithm, more importantly how public key and private key are generated. What are the steps of RSA algorithm ? - Select two prime numbers. Let’s say we select p = 3 and q = 11. - Find the multiplication of p and q as n = p × q . - Find the multiplication of p-1 and q-1 as Φ(n) = (p – 1) × (q – 1) . - Assume an exponent e such that 1 < e < Φ(n) and e is co-prime of Φ(n). The pair (n, e) is used as public key. - Find d such that d×e = 1 mod Φ(n). The pair (n, d) is used as private key. - Encryption: If m is the plain text number which is to be encrypted, the encrypted ciphertext c can be calculated as c = me mod n . - Decryption: The encrypted ciphertext c can be decrypted as m = cd mod n . These were the actual mathematical operations that happen while generating public/private keys and performing encryption/decryption. To brush up the mind a little, let’s encrypt and decrypt a random word by ourselves. Encrypt/Decrypt the word “computer” using RSA algorithm Alright. We have a word computer to perform encryption and decryption. But before doing so, we need public and private keys. Let’s look back a little to the algorithm part and do similar steps so that we can generate public key and private key number pairs. The first step is to assume two prime numbers. For simplicity, lets say p = 3 and q = 11. Now, n = p x q gives n = 33 and Φ(n) = (p – 1) x (q – 1) gives Φ(n) = 20. Assume a number for exponent e so that 1 < e < Φ(n) and e is co-prime of Φ(n). Let’s say that number is e = 7. So, we have now a public key pair (n, e) = (33, 7). That last step left is to find private key pair. For that we need to find d such that d×e = 1 mod Φ(n) . This implies, d = 3. You can calculate however you want, using calculator can be handy. So, we have found our private key pair as (n, d) = (33, 3) . Now, let’s perform encryption and decryption of word computer . Since, we need numeric value, first we need to assign numerical value to each character in the word. For the sake of simplicity, we can simply put numbers alphabetically. The letter a becomes 1, b becomes 2, c becomes 3, …….., z becomes 26. For encryption, we will use c = me mod n and for decryption, we will use m = cd mod n . The encrypted and decrypted data can be seen in the following table. \|Character\|\|me\|\|c = me mod n\|\|cd\|\|m = cd mod n\| I hope you understood the process. If you are a learner, try other words as well. Implementing on programming language can also boost your understanding. So, if you are a programming guy, try doing so on any language you like.
The set of basic symbols of the Roman system of writing numerals The major set of symbols on which the rest of the Roman numberals were built: I = 1 (one); V = 5 (five); X = 10 (ten); L = 50 (fifty); C = 100 (one hundred); D = 500 (five hundred); M = 1,000 (one thousand); For larger numbers: () V = 5,000 or \|V\| = 5,000 (five thousand); see below why we prefer this notation: (V) = 5,000. () X = 10,000 or \|X\| = 10,000 (ten thousand); see below why we prefer this notation: (X) = 10,000. () L = 50,000 or \|L\| = 50,000 (fifty thousand); see below why we prefer this notation: (L) = 50,000. () C = 100,000 or \|C\| = 100,000 (one hundred thousand); see below why we prefer this notation: (C) = 100,000. () D = 500,000 or \|D\| = 500,000 (five hundred thousand); see below why we prefer this notation: (D) = 500,000. () M = 1,000,000 or \|M\| = 1,000,000 (one million); see below why we prefer this notation: (M) = 1,000,000. () These numbers were written with an overline (a bar above) or between two vertical lines. Instead, we prefer to write these larger numerals between brackets, ie: "(" and ")", because: - 1) when compared to the overline - it is easier for the computer users to add brackets around a letter than to add the overline to it and - 2) when compared to the vertical lines - it avoids any possible confusion between the vertical line "\|" and the Roman numeral "I" (1). () An overline (a bar over the symbol), two vertical lines or two brackets around the symbol indicate "1,000 times". See below... Logic of the numerals written between brackets, ie: (L) = 50,000; the rule is that the initial numeral, in our case, L, was multiplied by 1,000: L = 50 => (L) = 50 × 1,000 = 50,000. Simple. (*) At the beginning Romans did not use numbers larger than 3,999; as a result they had no symbols in their system for these larger numbers, they were added on later and for them various different notations were used, not necessarily the ones we've just seen above. Thus, initially, the largest number that could be written using Roman numerals was: - MMMCMXCIX = 3,999.
Biomolecules refer to all kinds of molecules peculiar to living organisms. They are all organic matter. Typical cells contain 10,000 to 100,000 kinds of biomolecules, of which nearly half are small molecules, and the molecular weight is generally below 500. The rest are polymers of small biomolecules with a large molecular weight. Generally, more than 10,000, and some as high as 100,000 so they are called Biomacromolecules. The small molecular units that make up biological macromolecules are called Building blocks. Amino acids, nucleotides, and mono-saccharides are the building blocks of proteins, nucleic acids, and polysaccharides, respectively. Biomolecules have their own unique structures. Biological macromolecules have a large molecular weight, a large number of components, a large number, and an ever-changing arrangement sequence, so their structures are very complex. It is estimated that there are 10-10 types of protein alone. Biomolecules are in order. Each biomolecule has its own structural characteristics. All biomolecules exist in the life system with a certain order (organization). Biological macromolecules (biomacromolecule) and a low relative molecular biological organic compared to an organic compound having a high relative molecular weight higher substance groups. They are multimolecular systems formed by the polymerization of organic compounds of low relative molecular weight. Most of the biological macromolecules are formed by the aggregation of simple composition structures. The constituent units of proteins are amino acids and the constituent units of nucleic acids are nucleotides … Amino acids and fatty acids are called biological single molecules, which are closely related to life. They are the basic substances that makeup macromolecules. In terms of chemical structure, proteins are formed by dehydration condensation of α-L- amino acids, and nucleic acids are formed by dehydration condensation of purine and pyrimidine bases with sugar D- ribose or 2- deoxy -D-ribose and phosphate. Polysaccharides It is made by dehydration and condensation of monosaccharide. - Ammonia Formula \|\| why ammonia is toxic \|\| Ammonia Poisoning - Why Ozone Layer is Important \|\| Ozone Layer Depletion - What is the Concentration of solution \|\| How Concentration Affects Reaction - Why Carbon Cycle is Important \|\| How it Works - Haloalkanes and Haloarenes NCERT Solutions \|\| Haloalkane Structure - Carbon Dioxide Cycle and Formula \|\| How Carbon Dioxide is Produced From this, it can be seen that the chemical reactions that change from bio-organic compounds with low relative molecular weight to bio-organic compounds with high relative molecular weight are all dehydration condensation reactions. It refers to organic molecules with molecular weights of tens of thousands or more as the main active ingredient in the body. High relative molecular weight Bio-organic compounds (biomacromolecules) mainly refer to proteins, nucleic acids, and high-molecular-weight hydrocarbons. Common biological macromolecules include proteins, nucleic acids, and polysaccharides. This definition is only conceptual, opposite biomacromolecule is a small molecule material (carbon dioxide, methane, etc.) and inorganic matter. In fact, biological macromolecules are characterized by their various biological activities and their role in biological metabolism. Biological macromolecules are the basic substances that makeup life. For example, the molecular weight of certain peptides and certain lipids has not reached an astonishing level, but it also shows important physiological activities in the process of life. Formation of biological Macromolecules In primitive Earth conditions, there are two paths to achieve dehydration condensation to form a polymer, one is by heating, the low relative molecular mass and dehydrating and heating the polymeric material constituting, the other is the use of the presence on primitive earth dehydration Agent to condense. The former is often performed in a near-water volcanic environment, while the latter can be performed in a water environment. Biological macromolecules are synthesized in vivo by a simple structure, it can be decomposed through decomposition in a living body as a simple structure, usually during the synthesis consumes energy, released during decomposition energy. Biological macromolecules are important constituents of organisms. They not only have biological functions but also have large molecular weights and complex structures. In addition to the main proteins and nucleic acids in biological macromolecules, there are also sugars, lipids and their combined products. Such as glycoprotein, lipoprotein, nuclear protein and so on. Their molecular weight is often a hundred times or a thousand times greater than that of general inorganic salts. The molecular weight of proteins ranges from 10,000 to tens of thousands, and the molecular weight of nucleic acids can reach millions. The complex structure of these biological macromolecules determines their special properties, and their movements and changes in the body reflect important life functions. Such as metabolism to supply the energy and materials needed to sustain life, transfer genetic information, control embryo differentiation, promote growth and development, and generate immune functions. Human research on biological macromolecules has gone through a long history of nearly two centuries. Due to the complex structure of biological macromolecules and their susceptibility to denaturation due to temperature, acid, and alkali, it brings great difficulties to research. Before the end of the 20th century, the main research work was the extraction, properties, chemical composition and preliminary structural analysis of biological macromolecular substances. Early Research Results Since the 1830s, when the cytology was established, some people have studied proteins. The naming of proteins began in 1836. At that time, the famous Swedish chemist J. Berzelius and the Dutch chemist G. Mulder who was studying egg protein compounds proposed the use of “proteins”. Name such compounds. And listed it as the most important substance in the living system. By the beginning of this century, 12 kinds of 20 amino acids that make up proteins have been discovered, and the remaining amino acids have been discovered in 1940. At the end of the 19th century, organic chemists began to explore the structure of proteins. German organic chemist Fisher (E. Fischer ) cooperated with others to put forward the argument that peptide bonds between amino acids are connected to form proteins. In 1907, Fisher synthesized a 15 glycine and 3 leucine Consists of a long chain of 18 peptides. At the same time, Bernard (J.D. Bernal) and Astbury (W.T. Astbury) in the British crystal analysis school have used X-ray diffraction analysis to analyze the structure of proteins such as wool and hair, which prove that they are folded Curly fibrous substance. With the deepening of research, scientists have figured out that protein is the main component of muscle, blood, hair and so on, and has multiple functions. Discovery of nucleic acids Nucleic acids were discovered much later than proteins. A 24-year-old Swiss chemist, F. Miescher, who worked in Germany in 1868, extracted what was then called “nuclear material” from a patient’s wound pus cells. This was the earliest discovery of nucleic acids later recognized. Later Ke Saier (A.Kssel) and two of his students Jones (W.Jones) and Levine (P.A.Levene) understand the basic nucleic acid chemical structure confirmed nucleic acid is composed of many nucleotide composition Macromolecule. Nucleotides are made up of bases, ribose, and phosphate. There are 4 types of bases (adenine, guanine, cytosine, and thymine), and 2 types of ribose (ie, ribose and deoxyribose). According to this, nucleic acids are divided into two categories: Ribonucleic Acid (RNA) and Deoxyribonucleic Acid (DNA). According to a rough analysis, they believed that the amounts of the four bases in the nucleic acid were equal. Thus incorrectly deduced that the basic structure of the nucleic acid is that four nucleotides with different bases are connected into a tetranucleotide. Based on the polymerization of nucleic acids, this is the more famous “four-nucleotide hypothesis”. This hypothesis has dominated the study of nucleic acid structure for more than 20 years since the 1920s and has played a considerable obstacle to understanding complex nucleic acid structures and functions. Although nucleic acid was found in the nucleus at that time because its structure is too simple. It is difficult to imagine what role it can play in abnormally complicated genetic changes. Some scientists even thought that after the structure of the protein was clarified at that time. It was likely that the protein played a major role in heredity. Clarification of enzymes The elaboration of the enzyme began in 1897 when the German chemist E. Buchner extracted fermented yeast cells from ground yeast cells to ferment alcohol. According to Buschner’s research, enzymes extracted from the living body can work just as well. It not only hit the popular theory of vitality at that time but also brought biochemical research into the stage of understanding chemical changes in cells. Later, the British biochemist Harden (A. Harden) and much other research on the specific chemical steps of alcohol fermentation. In the 1920s, a large number of experimental results showed that the two processes of yeast fermenting sugar to produce alcohol and muscle contracting to turn sugar into lactic acid are basically the same, also known as glycolysis. By the research of many scientists in the 1930s, and finally integrated by German biochemist H.A. Krebs, a tricarboxylic acid cycle in which CO2 and H2O and energy (ATP) were finally produced by biological respiration was proposed. During this period, many scientists studied the metabolism of fats and amino acids, as well as the mutual conversion of sugars, fats, and proteins in metabolism and their biosynthesis. These processes are all catalyzed by enzymes. The role of inorganic substances and biological macromolecules The role of inorganic substances and biological macromolecules is mainly reflected in the role of metal ions and their complexes with biological macromolecules. It mainly includes the probe and recognition of metal ions to biological macromolecules, the competition between ligands and biological macromolecules to metal ions, and the transfer of ions and electrons within or between biological macromolecules. When metal ions are combined with biological macromolecules, obvious biochemical effects often occur. For example, some metal chlorides and gluconates can activate and inhibit glucose oxidase activity. The role of metal ions and their complexes with proteins mainly includes conformational changes caused by metal binding, subsequent biological effects caused by association and assembly. The study of metal ions and their interaction with DNA can help people understand the nature of life phenomena at the molecular level, and provide theoretical guidance for the rational design and search for effective therapeutic drugs. Such as the interaction of small molecular transition metal complexes with large molecular DNA can explore the structure, mechanism and function of large molecular DNA.
Say- there are two tomato in front of you, one of them are fresh, medium in size, color is normal. another is larger, redder, genetically modified (GM), produced with using more fertilizer, pesticide, herbicide etc. Which one will you pick? If you ask me, it makes no sense of me to pick the second one. Sustainable agriculture is this kind of theme. But if we are really being concerned about our food, health and diet, we should know about sustainable agriculture extensively. Think about it. The well-known covid-19 has been existing with us during march. Have we ever stopped consuming food! It’s a never-ending process. So why are we indifferent about our food consuming process as food and agriculture related to each other inextricably? Sustainable agriculture is farming in sustainable way keeping the ecological balance, which means cultivate the crop and raring the livestock in a minimal effect or zero loss of the environment. There are four sub-sectors of agriculture. Sustainable agriculture combined those sectors and sustain the ecological balance with a minimum effect. It’s very important to give equal priority of every component of nature that are related to our production system. Soil is the first component in gaining sustainable agriculture as it is the basis for food, feed, fiber, biological organism, reservoir of mine, chemical elements and other ecological services. Soil is the surface of earth crust and it is the core component of agricultural development. It is the component where we do crop production, raring livestock, pasturing, forestry, infrastructure acts. It’s very important to start the sustainability from soil. Tillage operation, chemical fertilizers, pesticides, herbicides disturb the harmony among the soil components. Tillage operation reduces the organic matter, biological organisms like earthworms, microbes, ants, and fertility of soil. The soil becomes dry before sowing seed, soil loses the nutrients like nitrogen, phosphorus, and other macromolecules. The symbiosis process hampers a lot. It decreases the infiltration rate of water causes runoff, soil erosion, volatilization and storing ability of soil. The soil become compact and attacked by pests and weeds easily. It can also cause a great hamper to the beneficial weeds, insects, frogs or living organisms thereby make a great danger in food chain and ecosystem. Tilling the soil results in dislodging the cohesiveness of the soil particle thereby inducing erosion. We should practice zero tillage or secondary tillage (less deep and loose only the upper portion of soil) to keep the soil fertile. When we use chemical pesticides, it causes a great hamper to the environment. They wash away with rain water and pollute the nearby pond, river and other water sources. It interrupts the rhythm among the ecosystem. We should try to use biological remedies like neem extract, beneficial insects, bait, or control the pest manually. Moreover, when we apply chemical fertilizer such as nitrate, phosphate or sulphate fertilizer in the soil, most of the time it hampers the ingredients of soil. It mitigates the fertility of soil and the microbes and nematodes that help with a great extent of the crop health as well as soil. Finally, in that way the toxic elements enter into our body through food. Apply organic matter, farm yard compost (FYM), green manure (GM), compost, animal excreta, cow dung, crop residues, oil cake to keep soil healthy. Organic matter increases the microbial activity of soil. It increases the water holding capacity, nutrient exchanging capacity, retains moisture. It also provides the aggregation of soil, keep balance in soil temperature and reduces soil surface crusting, and compaction. Reduce the use of inorganic fertilizer. Biological nitrogen fixation is a microbiological process which adds nitrogen into the soil from the atmosphere. Nitrogen fixing system offer an economically attractive and ecologically sound means of reducing external inputs and improving internal materials. Symbiotic systems such as legumes and rhizobium can be a major source of N in most of the cropping system. Fabaceae family plants such as lentil, mung, chola, khesari, soybean, peanuts, alfalfa, etc. can contribute in fixing nitrogen in the soil. These are also called cover crops. Cover crops in agriculture are used to cover the soil from being erosion, keep the soil moist and help to maintain balance in nutrients and organic matter. One should also keep focus on cropping pattern and crop rotation in an agroecosystem. The cropping pattern and crop rotation should be selected in this way that the soil can conserve the maximal level fertility, moisture, nutrients, water and its pace. As we are realized that every component is related to each other crucially, we have to take steps carefully. Not alone the Government, non profit organization and other institutions should help each other to spread the knowledge among the farmers as they are the real food hero. They should have to be taken into seminar and meeting to aware about sustainable agriculture and how to apply them. Field officers must give them proper knowledge and instruments before it’s too late. Zakiya Hossain Moon, Department of Agriculture, Noakhali Science and Technology University.
Credit: Copyright Doug Shore, Denver Museum of Nature and Science. The first new skull of a rare species of dinosaur Parasaurolophus (identified by the large hollow tube growing on its head) was discovered 97 years ago. The remarkable preservation of the new skull gives paleontologists the first opportunity to know definitively how such a strange structure grew on this dinosaur. For the first time, this study found properties to link the tubular-crested dinosaur species found in southern North America (New Mexico, Utah), which differ from the single northern species (Alberta). The region in northwest New Mexico dates back to about 75 million years ago, a time when North America was divided by a shallow sea and teeming with duck-billed dinosaurs, horned dinosaurs, and early tyrannosaurs. Excavations from the area are part of the natural heritage of the Diné (Navajo Nation) and Puebloan peoples. The new Parasaurolophus fossil, from the Northwest New Mexico Wildlands Administration Office, stresses the importance of protecting public lands as natural laboratories and repositories for scientific discoveries. Jan 25 – Denver – The first new skull discovered in nearly a century from a rare species of the iconic dinosaur Parasaurolophus was announced in the magazine today. Berg. The exquisite preservation of the skull, and especially the oddly shaped nasal passage, has finally revealed the structure of the crest after decades of disagreement. Despite the highly conformation of the specimen, the sample details show that the crest is shaped much like the tops of other duck-billed dinosaurs. “This specimen is a wonderful example of amazing creatures that arose from a single ancestor,” said Joe Search, curator of dinosaurs at the Denver Museum of Nature and Science and head of the team that discovered the sample. Imagine your nose growing across your face, three feet behind your head, and then turning around to hang over your eyes. “Parasaurolophus was breathing through eight feet of tubes before oxygen reached its head,” said Terry Gates, a paleontologist from North Carolina State University. “Over the past 100 years, ideas about the exaggerated tube logo have ranged from diving to super sniffers,” noted David Evans, Temerty’s chief vertebrate palaeontologist and vice president of natural history at the Royal Ontario Museum. “But after decades of study, we now think that these signs functioned primarily as audio resonances and visual displays used to communicate within their own species.” Among the most famous dinosaurs, Parasaurolophus had an oblong tube-like crest on its head that contained an internal network of bronchi. Three species of Parasaurolophus are currently recognized, ranging from Alberta to New Mexico in rocks dating between 77 and 73.5 million years ago. The new skull belonged to Parasaurolophus cyrtocristatus, previously known from a single specimen collected in the same area of New Mexico in 1923 by the legendary paleontologist Charles H. Sternberg. Both specimens display a shorter and more curved crest than the other species, a feature that may be related to their immaturity at death. The partial skull was discovered in 2017 by a Smithsonian fellow ecologist, Irene Speer, Ph.D., while exploring the badlands of northwest New Mexico as part of the Denver Museum of Nature and Science team. Located in the depths of Piesti / De Na-Zen Wild in New Mexico, only a small portion of the skull was visible on a steep slope of sandstone. Museum volunteers led by Sertich were surprised to find the intact summit as they carefully excavated the sample from the sandstone. The abundant bone fragments at the site indicated that much of the skeleton may have been preserved at one time on an ancient sand bar, but only the partial skull, part of the lower jaw, and a handful of ribs survived wear. Today, the badlands of northwest New Mexico are dry and sparse with vegetation, a stark contrast to the fertile lowland floodplains preserved in its rocks. 75 million years ago, when Parasaurolophus lived in the region, North America was divided into two land masses by a broad sea route. Laramidia, the strip of land to the west, extended from today’s Alaska to central Mexico, and hosted multiple episodes of mountain building in the early stages of building the Rocky Mountains today. These mountain-building events have helped preserve the diverse dinosaur ecosystems along their eastern sides, some of them among the best preserved and most enduring systems anywhere on Earth. Parasaurolophus shared fertile subtropical floodplains with other duck-billed dinosaurs, a variety of horned dinosaurs, and early tyrannosaurs along with many emerging modern groups of crocodiles, turtles, and plants. “The preservation of this new skull is amazing,” said Search. “He finally revealed in detail the bones that make up the crest of this amazing dinosaur that almost every child is obsessed with with dinosaurs.” “This only reinforces the importance of protecting our public lands for scientific discoveries.” “My jaw fell when I first saw the fossil,” Gates said. He continued: “I have been waiting for nearly 20 years to see a sample of this quality.” “This specimen is really great to be preserved,” said Evans, who has also worked on this iconic dinosaur for nearly two decades. “It answered long-standing questions about how the summit was built and about the health of this particular species. To me, this fossil is very interesting.” For decades, the Parasaurolophus family tree has placed the Parasaurolophus species (P. walkeri of Alberta and P. tubicen of younger rocks in New Mexico) as more closely related despite being separated by more than 1,000 miles (1,600 km) and 2.5 million years. Analysis of additional features of the skull except for the summit, along with information from other Parasaurolophus discoveries from southern Utah, suggests for the first time that all southern species from New Mexico and Utah may be more closely related than their northern cousin. This fits the patterns observed in other dinosaur groups of the same age, including the horned dinosaurs. The research was funded by the Denver Museum of Nature and Science through generous donations to the Laramidia Project. The paper describing the new skull of Parasaurolophus appears on the January 25, 2021, issue of the journal Berg. About the Denver Museum of Nature and Science The Denver Museum of Nature and Science is the Rocky Mountains region’s leading resource for informal science education. Our mission is to be a catalyst and ignite the community’s passion for nature and science. The museum envisions an empowered community that loves, understands, and protects our natural world. A variety of engaging exhibits, discussions, and activities help museum visitors to celebrate and understand the wonders of Colorado, the Earth, and the universe. The museum is located at 2001 Colorado Blvd., Denver, CO, 80205. To find out more about the museum, visit dmns.org or call 303.370.6000. The museum’s many educational programs and exhibitions are made possible in part by the citizens of the seven-county metro area through the Scientific and Cultural Facilities District (SCFD). The museum is accredited by the American Alliance of Museums. Connect with the museum on Facebook, Twitter, and Instagram.
Stierlitz wants to deliver a very important message s to the headquarters. He uses a prefix code defined in the National Standard. Unfortunately, the enemy knows the code, and the communication channel is tapped. In order to avoid suspicion, Stierlitz wants to split the ciphertext into several parts in such a way that none of the parts is a valid encoding of some string using the code. In order to maximize security, Stierlitz wants to maximize the number of parts that he will split the ciphertext into. Find this maximum number of parts, or determine that it is impossible to split the ciphertext satisfying the requirements. The first line of input contains one integer k (1 ≤ k ≤ 52): the size of the alphabet. The possible characters are enumerated from 1 to 52 in A-Za-z order, and the text of the message will only contain characters with numbers from 1 to k. The second line of input contains a non-empty string s of size up to 106 which consists of characters with indices from 1 to k (see enumeration rules described above). The next k lines contain binary codes of alphabet characters according to the enumeration order. Each character is encoded by a non-empty sequence of 0s and 1s of length at most k. It is guaranteed that no character has a code that is equal to the prefix of the code for a different character. Print a single integer: the maximum number of parts, or -1 in case it is impossible to split the ciphertext into parts satisfying the requirements. In the first example, the encoded text looks like 0010110011. The only way to split it into parts which are not valid encodings of any strings is 0 010110011. Therefore, the answer is 2. In the second example, it is possible to prove by induction that any string ending with 0 and not having three 1s in a row is a valid encoding of some string. Every suffix of the encoded text matches this criterion, therefore the answer is Problem Author: Alexey Danilyuk Problem Source: Petrozavodsk Summer 2018. t.me/umnik_team Contest
This Tiny Submarine Cruises Inside A Stomach To Deliver Drugs A tiny self-propelled drug-delivery device might someday make taking antibiotics safer and more efficient. Think of it as a tiny submarine scooting around inside your stomach, fueled by the acid there. Oral antibiotics are commonly prescribed life-saving drugs. Once an antibiotic is swallowed, it takes a trip to the stomach, where there's lots of acid. That stomach acid can break chemical bonds in the antibiotic and deactivate it. To keep that from happening, doctors often prescribe acid-reducing medications like Prilosec or Prevacid. But they can cause side effects such as headache, diarrhea and fatigue. So scientists at the University of California, San Diego, came up with a device designed to both reduce stomach acid and deliver medication without the side effects. The swallowable device reacts with stomach acid release of tiny hydrogen bubbles. The bubbles scoot it around the stomach, and a magnesium core reduces acidity as it goes. The tiny device is covered by a special polymer, like a jacket, that is sensitive to changes in the acidity. Once the acid in the stomach is neutralized, the polymer dissolves and the submarines unload their antibiotic payload. The micro submarine is only 20 microns across, about one-fifth the width of a human hair. It might sound like an episode of The Magic School Bus, the cartoon series that miniaturized children so they could explore inside the body, but the authors think it could be a big improvement in drug delivery. The study was led by Joseph Wang, the chair of nanoengineering at the University of California, San Diego. He says that the way that the scooting submarine delivers the drug actually helps the drug work better. "This active movement of the carrier improved the therapeutic efficiency in addition to the neutralization of the stomach [acid)." The device isn't ready for use in humans yet, but preliminary testing in mice shows that it's safe and effective, at least there. The study was published Jan. 20 in Angewandte Chemie International Edition. Copyright 2020 NPR. To see more, visit https://www.npr.org.
Due to the foremost importance of military conquests in the Aztec Empire, the elite warriors were among the most respected members of society. They were granted lands by the emperor and their status was on par with landed nobility. Becoming a warrior of distinction was also one of the surest ways of upward social mobility for the common people. The Order of the Aztec Jaguar Warriors was the order of the elite warriors and rigorous training was required for a male member of Aztec society to become a Jaguar Warrior. The word used for Aztec Eagle and Jaguar Warriors was cuāuhocēlōtl which was a combination of the world cuāuhtli meaning “eagle warrior” and ocēlōtl meaning “jaguar warrior”. According to Aztec beliefs, the Aztec Jaguar Warriors represented the Aztec god Tezcatlipoca who was the god of the night sky. On the battlefield, their jaguar costume was also thought to give them the powers of an animal. Since they were considered the bravest of warriors, they were deployed at the battlefront during military campaigns. Their foremost purpose was not to kill enemy soldiers but to capture them to be used in human sacrifice during the religious ceremonies of the Aztecs. Basic military training was part of education for all Aztec males. Children of the commoners were educated at schools called Telpochcalli while the children of the nobility were educated at Calmecac which were schools exclusively reserved for them. While the main emphasis of the education of the commoners was their military training, children of the nobility received education in a variety of disciplines such as government affairs, religion, and history. They were also trained to become military leaders and thus the elite orders like Aztec Jaguar Warriors mainly consisted of the nobility, although commoners who displayed exceptional talent were also sometimes inducted. After their early years education, young men went through more rigorous training to become jaguar warriors. Their training included such tasks as cleaning areas, building walls, and digging canals etc. This gave them the required physical strength and agility needed on the battleground. These trainees often accompanied their instructors, seasoned warriors, to the battleground where they transported military supplies, food, wood, and other supplies. Strict discipline was maintained during the training of these warriors and anyone breaching the discipline was severely punished. One customary punishment was to beat them and remove their hair which humiliated them in front of everyone. In more serious cases, such as the drinking of pulque which was strictly prohibited, students could even be beaten to death. On the battleground, Aztec Jaguar Warriors were the leaders of the military along with the Eagle Warriors. They lead the armies and formed the military strategies. Even off the battlefield, they were expected to be the leaders and were considered highly respected members of society. Their rank was on par with the Aztec nobility and they were often granted land by the emperors. These lands became their private property and their subsequent generations could inherit it. After becoming Jaguar warriors, they were also given certain other privileges such as drinking of pulque, taking of concubines, and dining at the royal palace. Another privilege of the Aztec Jaguar Warriors was participation in gladiatorial sacrifices. A variety of images and artistic representations of Aztec Jaguar Warriors survive which show the kind of weapons they used on the battlefield. Common weapons included spears, atlatls, and macuahuitl. Atlatl was the Aztec version of bow and arrow. It was especially designed so that an arrow could be flung with more power than with an ordinary bow. Macuahuitl was a wooden sword which was studded with obsidian volcanic glass and was one of the most prized weapons of the elite Aztec warriors. Another important weapon was called cuauhololli which was a club made of hard oak with a handle made for throwing at running targets. The costumes of the Aztec Jaguar Warriors, as the name suggest, was similar to that of a jaguar. They wore jaguar skins along with a helmet or a shroud which resembled the head of a jaguar. Behind this costume there was religious and cultural symbolism of the Aztecs. Aztecs believed that wearing the skin of a jaguar would give them the strength of that animal. There was also a religious reason behind capturing the enemy soldiers instead of killing them on the battleground. It was thought that capturing the enemy soldiers for human sacrifice was a far greater way of honoring the gods than simply killing the soldiers. Thus a warrior who killed the enemy soldiers instead of capturing them was considered lacking in skills. Gladiatorial sacrifice was a grand event of sacrifice attended by the elite Aztec warriors such as Eagle and Jaguar Warriors. In this ceremony, Aztec Jaguar and Eagle Warriors paraded the captives on the streets and brought them to the sacrificial stone. The captives could be made to drink pulgue in order to reduce their resistance. The warriors would then attack the tied up captive and kill him. Usually, but not exclusively, an obsidian laced club was used for this purpose. Only Aztec Jaguar and Eagle warriors attended this ceremony and it was different from the usual religious ceremonies of the Aztecs. However, if sometime the captives survived the ceremony, they would be killed by the offering priests the next day. The Aztec Empire was a military empire and any warrior of distinction was held in high esteem. Among these elite warriors of the Aztecs were the Aztec Jaguar Warriors whose status was considered on par with the Aztec nobility. Young men went through rigorous military training in order to become Aztec Jaguar Warriors. The Order mostly inducted young men from the nobility but sometimes commoners who displayed exceptional talent were also included. The main purpose of these warriors was to capture as many prisoners as possible for gladiatorial sacrifice. Aztec Jaguar Warriors were regularly granted lands by the emperors and they enjoyed privileges which were prohibited to the commoners.
Last year a group of researchers published work in which they showed that human teeth maintain a permanent record of vitamin D deficiencies because the condition causes defects in dentine mineralization. Now that same group of researchers has expanded their work by demonstrating how vitamin D deficiencies can be tracked in human populations through space and time. In their new study, lead author Dr. Megan B. Brickley and her colleagues combed through published reports, collecting data on over 200 teeth recovered from archaeological sites with dates as old as the late Pleistocene and from modern twentieth century collections. Their findings indicate that vitamin D deficiencies have been present in human populations since at least the late Pleistocene and that the severity of the condition has gotten worse over time. Brickley and her co-authors believe that, when applied to much larger samples, their technique will be useful in teasing out relationships between vitamin D levels and “…long-term health, variation in skin pigmentation, immigration, and social and cultural factors operating in past communities.”** Brickley et al.’s latest paper can be found here. http://www.journals.uchicago.edu/doi/full/10.1086/691683#rf8 Brickley, Megan B., Lori D’ Ortenzio, Bonnie Kahlon, Annabelle Schattmann, Isabelle Ribot, Emeline Raguin, and Benoit Bertrand. “Ancient Vitamin D Deficiency: Long-Term Trends.” Current Anthropology, Vol 58, No 3, June 2017. Section: Following Abstract, paragraph 3, sentence 2, line 5. *Section: Conclusions, sentence 3, line 6.
Overview – what are Embryonic Stem Cells? Embryonic stem cells are the inner cells that have been removed from newly- conceived babies, or embryos. These cells are special and they lie deep within the centre. They have to be cut out (dissected) together with the inner cell mass. These special cells lie together with others in this inner cell mass. The other cells produce the certain organs in a human person; while the special cells are considered special because they are ‘blank’ (like the blank tiles in scrabble) and have the potential to mature into anything. They are not yet committed, not yet specialised, to produce the cells of a specific organ like a brain or a heart. They still have the potential to produce different kinds of cells. Hence these embryonic stem cells are called ‘pluripotent’. They have more than one potential; they are not limited to just producing skin, bone, or heart tissue. The goal of cutting out these cells in the inner cell mass is to eventually use these special cells to replace the unhealthy ones in adults, in order to cure certain diseases. Obtaining these cells destroys the embryo. The babies used in this way are the left-over babies in IVF clinics – he surplus babies – produced just in case one isn’t successful. (In over 99% of IVF baby attempts, surplus babies have been made.) This method was researched by Australian scientists; other scientists dissected inner cells out of 5 to 9 week embryos to obtain their cells which would later form sperm or eggs. These cells are also special or ‘pluripotent’. Even if researchers are successful in their plan to extract these ‘blank’ cells, they must kill the surplus IVF babies in order to do so. The dissection and destruction of these babies is considered satisfactory by embryonic stem cell scientists. In defence of this process they say embryos are destroyed all the time by IUDs (intra-uterine devices to stop a pregnancy growing in the womb), and by the minipill (the progesterone only pill used especially by breast-feeding women). These examples are used to justify the dissection of embryos in the laboratory, and their destruction is part of this embryo research. made for embryonic stem cell use made for embryonic stem cell use - Embryos are not human beings. - Human embryonic stem cell research will cure disease. - Embryonic stem cells have a capacity to turn into any tissue in the body. - Excess embryos will be destroyed; they might as well be used for some good. - All research avenues should be used. Why a embroyonic stem cell research is not the answer is not the answer A human embryo is a human being in its very earliest stage of development. Moral relevance does not decline or increase with age. The youngest through to the eldest of the human species are equally morally relevant. It is not moral to kill one innocent human being in order to save another. There should be no preference of older human beings over younger human beings. All demand equal moral recognition, dignity and protection. Natural philosophy informs us that every living being has a soul, and that soul is the principle that gives life to the body. A living human being has a living and eternal soul from the very first moment of its existence. Therefore, to sacrifice one or some innocent human beings for the health of others is immoral. The fusion of sperm and egg from the human father and mother at conception creates an embryo. This embryo is human, genetically distinct from both parents, self-directed and unified; whole, therefore, human. The embryo, even at its earliest stage, contains all that it requires to continue his/her development towards birth, infancy, adolescence and old age. The human embryo is, simply, a very young human being; and as a consequence, it demands moral recognition as a member of the human species. Regenerative medicine seeks to replace diseased adult tissue with healthy adult tissue. The only use for embryonic stem cells in regenerative medicine is: - For more research. Much research is planned for this field. - Possible donor cells given to a damaged or diseased adult (or child). Embryo stem cells used for this purpose are not the same as the cells in the body of the person who is receiving them. They are not identical. They do not match the patients’ cells and can cause allergy or immune reactions. Donor cells from other embryo persons are called un-matched or embryo ‘non-matched’ donor tissue. - possible donor cells taken from a ‘cloned embryo’. This is a newly made embryo that has been put together as an identical twin of the damaged or diseased adult. This new identical twin embryo is made and grown in the laboratory just to harvest its inner cells. Because their inner cells are identical to its older twin’s cells, they will ‘match’ the adult’s cells. It is hoped these will not cause an immune reaction. They are known as embryo ‘matched’ donor tissue. As a research tool, embryonic stem cells behave differently in the laboratory (in vitro) compared to in humans (in vivo). Therefore, insights into the laboratory behaviour of the cells are not necessarily the same in practice, and we already have indirect models of cell behaviour available. Embryonic stem cells are not useful in non-matched adults, since they require life-long immunosuppressive therapy with considerable side effects. Therefore, embryonic stem cells are considered most useful if derived from cloned adult stem cells. Unfortunately, human cloning produces cancerous and aged cells because the DNA of the embryo starts growing with DNA that is already as old as the original donor. Aged DNA combined with unstable embryo cells, poses many new health risks for a person receiving the embryo stem cell treatment. These clinical problems posed by regenerative medicine using embryo cells are widely acknowledged. Much of the language surrounding embryonic stem cell research focuses on “hope” and potential. Millions of dollars in monetary support and a celebrity A-list of proponents have done little to produce a result from these unethically-obtained cells. The main selling point of embryonic stem cells is that they are immature, so to speak, and have not decided what type of cell they are going to be. Thus they could, potentially, be encouraged to develop into whatever the scientist desires. This desired malleability comes with an undesired side effect: unpredictability. Scientists at the prestigious Mayo Clinic write that, “Embryonic stem cells also could grow irregularly or specialise in different cell types spontaneously (like tumors)…Embryonic stem cells also might trigger an immune response in which the recipient’s body attacks the stem cells as foreign invaders, or simply fail to function normally, with unknown consequences.” Mayo Clinic, 3/2013. Catholic teaching on the use of embryonic stem cells: Pope Benedict XVI in Donum Vitae 1987: “This Congregation [for the Doctrine of the Faith] is aware of the current debates concerning the beginning of human life, concerning the individuality of the human being and concerning the identity of the human person. The Congregation recalls the teachings found in the Declaration on Procured Abortion: “From the time that the ovum is fertilized, a new life is begun which is neither that of the father nor of the mother; it is rather the life of a new human being with his own growth. It would never be made human if it were not human already. To this perpetual evidence…modern genetic science brings valuable confirmation. It has demonstrated that, from the first instant, the program is fixed as to what this living being will be: a man, this individual-man with his characteristic aspects already well determined. Right from fertilization is begun the adventure of a human life, and each of its great capacities requires time…to find its place and to be in a position to act.” (25) This teaching remains valid and is further confirmed, if confirmation were needed, by recent findings of human biological science which recognise that in the zygote resulting from fertilization the biological identity of a new human individual is already constituted. Certainly no experimental datum can be in itself sufficient to bring us to the recognition of a spiritual soul; nevertheless, the conclusions of science regarding the human embryo provide a valuable indication for discerning by the use of reason a personal presence at the moment of this first appearance of a human life: how could a human individual not be a human person? The Magisterium has not expressly committed itself to an affirmation of a philosophical nature, but it constantly reaffirms the moral condemnation of any kind of procured abortion. This teaching has not been changed and is unchangeable. (26) Thus, the fruit of human generation, from the first moment of its existence, that is to say from the moment the zygote has formed, demands the unconditional respect that is morally due to the human being in his bodily and spiritual totality. The human being is to be respected and treated as a person from the moment of conception; and therefore from that same moment his rights as a person must be recognised, among which in the first place is the inviolable right of every innocent human being to life.” Catechism of the Catholic Church II. Body and Soul but Truly One 362. The human person, created in the image of God, is a being at once corporeal and spiritual. The biblical account expresses this reality in symbolic language when it affirms that “then the LORD God formed man of dust from the ground, and breathed into his nostrils the breath of life; and man became a living being.” President George W. Bush Aug. 9, 2001, in an address to the nation on stem cell research: “There’s just too many areas that are inconclusive out there for us to get on a slippery slope to say we should take life in order to enhance life.” “The moral issue does not disappear just because the embryos are very small or because they are no longer wanted for reproductive purposes: Because they are living human embryos, destroying them is not a morally neutral act. Just as no society can afford to be callous to the needs of suffering humanity, none can afford to be cavalier about how it treats nascent human life.” The Catholic church is not against adult stem cell research For the Catholic Church, the issue of stem cell research is not one between science and ethics, much less between science and religion. Rather, the Church asks us to decide how our society will pursue scientific and medical progress. The ‘greater good’ cannot come from directly taking innocent human lives. There is no moral objection to research and therapy which do NOT involve harm to human beings at any stage of development and is conducted with appropriate informed consent. Adult stem cells (that is, stem cells extracted from adults rather than embryos) and umbilical cord blood have been shown to produce cells that can benefit patients suffering from heart disease, corneal damage, sickle cell anemia, multiple sclerosis and many other diseases. The Catholic Church has been, and will continue to be, among the leading supporters of ethically responsible advances in the medical use of adult stem cells: “Methods which do not cause serious harm to the subject from whom the stem cells are taken are to be considered licit. This is generally the case when tissues are taken from: a) an adult organism; b) the blood of the umbilical cord at the time of birth; c) fetuses who have died of natural causes.” Dignitas Personae . Adult stem cell research successes Adult stem cells, whether obtained from the individual they are to be used in or from a donor, have had great success in the last 40 years. One of the more common uses of adult stem cells is in bone marrow transplant. This is used to treat blood cancers such as leukemia. Bone marrow contains adult stem cells which can be harvested from either the sick individual or a donor without significant harm. Research continues on ways to combat heart disease. Scientists from the University of Minnesota have been making headway using adult stem cells to create a new heart. Osiris Therapeutics of Maryland is using adult stem cells in diabetic research. Neostem, of New York, with the blessing of the Vatican, is studying adult stem cell use in heart disease, autoimmune disorders and tissue regeneration. Adult stem cell transplants are also widely used to treat such diseases as anemias, leukemias, lymphomas, and other cancers, spinal cord injuries, Parkinson’s disease, multiple sclerosis, diabetes, lupus, Crohn’s disease, ocular degeneration, blindness, heart disease, leukemia, non-Hodgkin’s lymphoma, aplastic anemia, and sickle cell anemia. Suggested articles for further reading and links - Keane, Eamonn; “The Brave New World of Therapeutic Cloning” booklet 2nd revised and expanded edition.
What’s The Difference Between Primary And Secondary Emotions? The ability to feel emotions is part of what makes us human. Many people struggle to understand different emotional states they may experience and what causes them. Learning about the different types of emotions—including primary and secondary emotions—can help. What Are Emotions, Exactly? Emotions come from the Latin term emovere meaning “moving”. The term is a combination of the words “energy” and “motion”, which captures the often fleeting nature of human emotions. They typically occur when triggered by an internal thought, an external event, or a thought in response to an event. Emotions help us understand and interpret what we’re experiencing. Positive emotions are meant to encourage us to pursue the thought or situation that caused them again. That’s because these types of feelings activate the reward systems within the central nervous system, which helps us feel safe. Negative emotions, on the other hand, help warn us of potentially dangerous situations to avoid or be aware of in the future. Emotions helped humans stay safe enough to survive and evolve over time. While the world we live in today doesn’t have the same risks as the world of our ancestors, emotions can still help us make sense of our surroundings and defend ourselves. It’s important to note that people may feel different emotions with different levels of intensity. Some level of variance in this is perfectly natural. For example, roughly 20% of humans fall into the category of “highly sensitive people”, which is “a trait associated with greater sensitivity and responsiveness to the environment and to social stimuli”. In other words, some people may naturally feel some emotions with more or less intensity, which is not inherently problematic. In other cases, however, experiencing emotions outside of what’s considered to be a typical or healthy range may be a sign of an underlying condition. For instance, past trauma may cause a person to have difficulty feeling and expressing emotions or to feel and express emotions that are out of proportion to events—known as emotional dysregulation. In still other cases, a mental illness like depression may cause distorted thought patterns, which can contribute to a person experiencing strong emotions that are based on a warped view of reality. In these situations, a therapist may be able to help an individual build a healthier relationship to their emotions. Primary Vs. Secondary Emotions Human emotions are complex, and researchers don’t fully understand or agree on the details of where they come from or exactly how to classify them. That said, one of the more popular theories is known as the Plutchik Model of Emotions, in which psychologist Robert Plutchik posits that there are eight primary emotions that can be paired into polar opposites: joy and sadness, anger and fear, trust and distrust, and surprise and anticipation. According to this model, one of these eight always comes first, with any following emotions being classified as secondary. For example, getting into a minor car accident might make you feel fear as a primary emotion, with annoyance about the other driver’s actions or remorse about your own as secondary emotions. Typically, primary emotions are more transient than secondary emotions. They may also have an effect on body language and facial expressions, or may trigger other physiological responses. They usually reflect a more instinctive initial reaction, until our logical brain starts processing the event. Once cognition kicks into gear, the way you feel about something that happened may change. That’s where secondary emotions—which can be far more long-lasting—may come into play. To tell if an emotion you’re feeling is primary or secondary, think about the timing. If it’s the first thing you feel in response to a stimulus such as an event or conversation, it’s likely a primary emotion—especially if it came on strongly and started fading shortly after. If an emotion lingers long after the event has happened, it’s likely to be secondary. If the emotion is complex and/or relates to past experiences, it’s almost always secondary. Where Do Secondary Emotions Come From? If primary emotions are typically instinctive, where do secondary emotions come from? The answer is that many of them are learned responses. Secondary emotions often refer to how you feel about the primary emotion you experienced, and we may face conflicting information on how we should relate to different primary emotions. These things may be instilled in us by our parents or caregivers, other role models, the media, etc. For example, you may have learned to feel shame or embarrassment as a secondary emotion after feeling anger or sadness. While these associations may be deep-seated, it may be possible to change them with effort and patience over time. How Understanding Your Emotions Can Be Useful Distinguishing between primary and secondary emotions may help you gain a deeper understanding of yourself and your own emotional landscape. Understanding what triggers certain secondary emotions and how to work through them can be an insightful exercise. When secondary emotions cause us problems or interfere with our lives or relationships, it can be helpful to delve into their triggers and potentially address any wounds that may exist from past trauma or other negative experiences. Plus, understanding how your emotions work can help you become more aware of and gain more control over them, which can benefit your overall mental and social well-being. Experiencing emotions is a perfectly normal and healthy part of the human experience. However, if you find that your emotional reactions are causing distress or problems in your life, a therapist may be able to help. They can work with you to identify the secondary emotions you’re feeling in response to certain stimuli and potentially discover the underlying causes. If wounds from past experiences are playing an outsize role in your reactions, they may be able to help you on the path to healing. If you feel more comfortable meeting with a therapist virtually, online therapy is one available treatment option. A platform like BetterHelp can connect you with a therapist who you can speak with via phone call, video call, and/or chat to address the emotional challenges you may be facing. Research suggests that virtual therapy may be a viable alternative to in-person sessions, and many find it to be a more convenient and cost-effective option as well. Regardless of the treatment method or format you choose, getting in touch with your secondary emotions and their roots can help you feel more stable, healthy, and in control of your life. Understanding the distinction between primary and secondary emotions can be the first step on the path toward creating a more balanced emotional life. If you’re looking for assistance or guidance on this journey, a mental health professional may serve as a helpful resource.
How hydrogen propulsion impacts the climate Fuel cells and engines that burn hydrogen produce water vapor that can form contrails. MTU Aero Engines is already working on minimizing the possible climate effects. 06.2021 \| Text: Denis Dilba Denis Dilba holds a degree in mechatronics, is a graduate of the German School of Journalism, and founded the “Substanz” digital science magazine. He writes articles about a wide variety of technical and business themes. A lack of water vapor in the atmosphere would make life on Earth extremely unpleasant. As the greatest contributor to the natural greenhouse gas effect, water vapor plays a key role in maintaining the average temperature of our planet at around 15 degrees Celsius—and not the freezing point or below. Without it in the Earth’s atmosphere, there would be no clouds or rain. In other words, water vapor is critical to enabling life as we know it. However, if water vapor enters the atmosphere through aircraft engines rather than through natural evaporation from rivers, lakes and oceans, it contributes to anthropogenic global warming in the same way that carbon dioxide (CO2) does—especially if it forms long-lasting contrail cirrus clouds at high altitudes. Scientists still do not fully understand this phenomenon or the climate effect caused by nitrogen oxides, and research into the complex processes that take place in the atmosphere continues to this day. In the past, aviation goals have focused on minimizing the direct impact of CO2, an area in which the industry has indeed made great strides: between 1990 and 2019 alone, the average fuel consumption of Germany’s passenger aircraft fleet, and by extension its CO2 emissions, was reduced by 43 percent—thanks in part to more efficient engines. Over the past two decades, however, countless research findings have painted an ever-clearer picture: CO2 is only one aspect of aviation’s impact on the climate. “On a global scale, we can now say that about one-third of air transport’s climate impact is attributable to carbon dioxide emissions and about two-thirds to the formation of persistent contrails, nitrogen oxides and other aerosols,” says Reinhard Herbener from the German Environment Agency (UBA) in Dessau-Roßlau, who is an expert on air transport’s climate impact. The new goal: Reduce all factors that impact climate Published in September 2020, the most comprehensive study to date on aviation’s climate impact confirms and clarifies these findings. It is the first time that researchers have also accounted for the impact of spatially inhomogeneous effects in their calculations. These include the occurrence and effect of contrail cirrus clouds, which have a different distribution around the world depending on the air traffic and weather conditions. “Generated by water vapor emissions, these clouds can have either a warming or a cooling effect on the Earth’s temperature,” says Professor Robert Sausen of the Institute of Atmospheric Physics at the German Aerospace Center (DLR) in Oberpfaffenhofen. The study was able to quantify their climate impact with greater precision than previous research. “We found that contrail cirrus clouds are less than half as damaging to the environment as previous estimates suggest. Nonetheless, they are still aviation’s greatest contributor to global warming,” Sausen says. MTU Aero Engines, too, has been following all the recent developments in the scientific findings, says Fabian Donus, Innovation manager at MTU: “We’ve been working for quite some time to incorporate the new insights into our climate targets and technology developments.” One approach Donus and his colleagues are taking is to re-examine today’s engines from this new perspective to find the best solution overall for minimizing factors that affect the climate. That’s because even modern engines are capable of generating persistent contrails under certain environmental conditions: when kerosene is burned, water vapor is the second main product of the reaction after CO2. Another major focus for MTU’s engineers is the climate impact of next-generation, hydrogen-based engines, as these are still not 100% climate friendly. Because even though the two solutions in focus—modified engines that burn energy-rich hydrogen directly and fuel cells that use it to power electric propulsion systems—no longer generate CO2 emissions, they do still produce water vapor. Innovation manager at MTU: In addition to re-examining today’s engines from the new perspective of finding the best solution overall for minimizing climate factors, Fabian Donus is focusing on the climate impact of next-generation engines based on hydrogen, as these are still not quite 100% climate friendly. Direct hydrogen combustion The technology for direct hydrogen combustion could be ready somewhat sooner and pave the way for the flying fuel cell, which MTU estimates might take off as early as 2035. “From a technical perspective, we believe the effort involved in retrofitting current engines to work with hydrogen will be moderate,” says Dominik Wirth, expert in advanced population systems at MTU. Burning hydrogen produces water vapor and nitrogen oxides as the only emissions “We’re currently conducting an elaborate study to determine what climate impact this will have and how it will compare with the impact from conventional engines and the fuel cell,” Wirth explains. What we can be certain about, he says, is that hydrogen combustion produces more water vapor than conventional fuels do—but that’s not necessarily a bad thing: “The vast majority of contrails evaporate again just a few hundred meters behind the aircraft and are completely irrelevant in terms of their climate impact.” MTU expert for advanced propulsion systems: Burning hydrogen produces water vapor and nitrogen oxides as the only emissions. Dominik Wirth is investigating what that means for the climate. In the opinion of UBA expert Herbener, hydrogen combustion offers the advantage that it produces significantly fewer aerosols than conventional engines. “It doesn’t emit any sulfur or soot, which can become condensation nuclei and stimulate cloud formation.” While this cleaner form of combustion is certainly advantageous, it does not prevent the resulting water vapor emissions from condensing, since natural aerosols such as dust particles or organic molecules are also present in the atmosphere and act as cloud seeds. For that reason, Wirth and his team are also investigating how to minimize the climate impact of persistent contrails—quite a challenge given the countless parameters involved. According to Wirth, these include the size and number of ice crystals that form around the condensation nuclei, the solar radiation and the brightness of the backdrop. However, he believes that deeper knowledge of the processes behind cloud formation could hold the key to reducing the effect that contrails have on the climate. Chief Engineer Flying Fuel Cell at MTU: With the exception of water vapor, fuel cells will be emissions-free. Barnaby Law is exploring how some of this water can be recirculated back into the fuel cell. Flying fuel cell With the exception of water vapor, fuel cells will be emissions-free. “And because operating processes in fuel cells use much lower temperatures than those involved with hydrogen combustion, they emit more water in liquid form,” explains Barnaby Law, Chief Engineer Flying Fuel Cell at MTU. That’s why propulsion systems based on fuel cells don’t generate any nitrogen oxides either, as these start to form only at temperatures of 1,300 to 1,400 degrees Celsius and above. One aspect Law and his colleagues are working on is how to recirculate a certain amount of the water produced back into the fuel cell. “The system needs a certain amount of moisture, which you don’t get at high altitudes,” he explains. As a way to further minimize the fuel cell’s climate impact, Law plans to alter the emitted water as required: “We can produce large or small water droplets or even draw liquid water out of the system as a small trickle.” But as is the case with hydrogen combustion, he explains, the first step is to refine our understanding of how various factors—such as the size and distribution of the droplets, different temperatures, and altitude—interact and what impact this has on the environment. “It might even be possible to design the fuel cell to emit no harmful water content at all,” Law says. Time will tell if that will work or not, he adds, “but what we do know is that we have some scope to influence water emissions.” Other methods can be employed alongside these technical solutions to minimize the potential effects of water vapor. Sausen from the DLR is confident it will be possible to plan climate-friendly flight routes for hydrogen engines in the same way as for conventional engines. “We have to pull out all the stops to reduce our climate footprint, period.” Donus says. “That of course applies to conventional engines, too. A variant of the GTF engine that offers even greater fuel efficiency has been in the works for quite some time.”
Because they fly, bats are often mistaken for birds. Bats are mammals, however, not birds. They have soft fur and large ears, and as babies they drink milk from their mothers. They are distinguished by their ability to navigate at night by using a system of sound vibrations (echolocation). This allows them to chase insects through thick forests on the darkest of nights without striking branches or other objects. More than 1,200 species of bats are currently classified in the order Chiroptera. Bats are found throughout the world except in the cold polar regions. They are particularly abundant in rainforests and jungles. The United States is known to have 19 genera encompassing about 45 species of bats. They mostly live in the southwestern states, where the weather is relatively warm year-round. Bats are shy animals and will try to avoid humans. They are active at night and spend the day sleeping in out-of-the-way places, such as in caves or on high branches. They often rest together in colonies, or large groups, for extra protection and to keep warm. All bats have the same general shape and wing structure, but they vary considerably in size. The largest bats have a wingspan of about 5 feet (1.5 meters) and a weight of about 2.2 pounds (1 kilogram). One of the smallest bats has a wingspan of barely 6 inches (15 centimeters) and weighs about 0.07 ounce (about 2 grams). Bats vary in color and in fur texture. They generally have shades of brown, tan, gray, or black on top and lighter shades on the underside. Red, yellow, or orange variations occur in many species. Speckled or mottled patterns are common, as are bright or light-colored spots or stripes. The chest and shoulders of bats are large and strong to provide power to the wings, which are generally dark and hairless. The thumb, always free of the wing, is used for walking or climbing in some species. In others it is used for handling food. Only the thumb—and occasionally the index finger—ends with a claw. Bats that walk often have pads or suction disks on their thumbs or wrists or both. The legs and feet are only strong enough to hold on when hanging upside down from a perch, which is how bats rest or sleep. Some bats have tails, while others are tailless. Bats often have muzzles that resemble rodents or foxes, but in many the face has a pushed-in pug-nosed appearance. Bats that drink nectar have an elongated snout to house a long tongue. Many bats have a fleshy piece of skin called the nose leaf surrounding the nostrils. Scientists believe that this flap may help to direct the bats’ outgoing calls. The ears are generally large, which probably helps them detect incoming signals. Most bats eat small insects and are thus important in the control of insect pests. These bats identify and track the insects in flight by echolocation. Other bats feed on fruits that are usually green or brown in color. Some bats feed, at least in part, on nectar and pollen. Others eat large insects, spiders, and scorpions that they find on the ground, on walls, or on vegetation. These bats may either land on and kill their prey before taking off with it or pick it up with their teeth while hovering. The guano, or droppings, of fruit- and insect-eating bats is used for agricultural fertilizer in many countries. In the past it was used as a source of nitrogen and phosphorus for ammunition. Several types of bats are meat-eaters that feed on larger prey than insects, including small rodents, shrews, other bats, sleeping birds, tree frogs, and lizards. A few even catch and eat small fish. Vampire bats (family Desmodontidae) feed on the blood of large mammals or birds. They bite an animal’s skin until the blood flows freely and then lick the blood with their tongue. Each vampire bat requires about 0.5 ounce (15 milliliters) of blood per night. Nearly all species of bats are nocturnal. They roost, or sleep, during the day and look for food at night. Night flying protects them from most predators, exposure to the sun, and high temperatures. Bats are meticulous in their grooming. They spend a fair part of the day and night combing and grooming their fur and cleansing their wings. Generally, they comb with the claws of one foot while hanging by the other. They remove the combings and moisten their claws with their lips and tongue. Bats use their mouths on the wings, perhaps oiling the skin with the secretions of skin glands while cleansing it. Adult bats are known to often separate themselves according to gender. Pregnant females in many species occupy special nursery roosts until their young are independent. In some species males and females occupy the same general roost but gather in separate clusters. In others the males and females mix together or arrange themselves into a pattern within a group—the females in the middle, for example, and the males toward the outside. Bats are completely specialized for flying, but the flight styles vary. Some groups are adapted for flying in open spaces and high altitudes, so they have long, narrow wings and swift movements. Others have short, broad wings and slow flight, which is best for hovering as they pick prey off vegetation or feed on flowers. Some bats take flight easily from the ground simply by flapping, while vampire bats leap into the air and then spread their wings and fly. Some free-tailed bats (family Molossidae) roost well above the ground because, upon takeoff, they fall before becoming airborne. Though flight speeds in the wild are hard to measure, some species have been timed on average at 11.7 to 20.8 miles (18.7 to 33.3 kilometers) per hour. While flying, bats can control each of the four fingers of the wing separately. The placement of the fingers and arms determines turning, diving, landing, and hovering. Bats fly in straight lines except when they are catching insects or avoiding obstacles. Bats may pursue and capture insects at a rate of up to two per second. In many cases bats do not move much other than in flight. Bats that hang in caves may move across the ceiling by shifting their toehold, one foot at a time. Some may walk or crawl on either horizontal or vertical surfaces, using hind feet, wrists, and thumbs. Many move freely either backward or forward, a convenience for entering and leaving crevices. Vampire bats also may leap from roost to roost. Bats are not known to swim voluntarily, but, when they fall into water, they generally swim competently. Bats roost, or sleep, during the day by hanging upside down by their feet. They choose particular places, such as caves, crevices in cliffs, tree hollows, animal burrows, parts of buildings where people are scarce (for example, a roof or an attic), or the hollow core of bamboo stalks. Some species roost in the open, as on tree trunks or in the branches of trees, under palm leaves, or on the surface of rocks or buildings. For some the darkness, stability of temperature and humidity, and isolation from predators provided by caves and crevices is preferred. Others like the heat and dryness of sun-exposed roosts. Many bats also occupy nighttime roosts for napping, for chewing food, or for shelter from bad weather. Bats usually form large colonies, especially if they are cave-dwelling species. In general they roost in dense clusters, pressing against one another, although many are widely spaced and do not touch when roosting. Many species form smaller groups of several dozen to several hundred. Bats occasionally roost on their own, and sometimes the adult female roosts only with its most recent offspring. Many bats from mild climates migrate each year to and from summer roosts and winter hibernation sites. They often will occupy the same roosts each year. When migration occurs is probably instinctive and influenced by weather and the availability of food. The North American red and hoary bats (Lasiurus borealis and L. cinereus) and the silver-haired bat (Lasionycteris noctivagans), for instance, migrate in the fall. At that time they leave from the northern United States and Canada to the southern United States and beyond. They return in the spring. Bats emit short high-frequency pulses of sound (usually well above the range of human hearing) and listen to the echoes returning from objects in the vicinity. By interpreting returning echoes, bats may identify the direction, distance, velocity, and some aspects of the size of objects that draw their attention. Echolocation is used to locate and track flying and terrestrial prey, to avoid obstacles, and possibly to regulate the height at which the bat is flying. It may also serve as communication signals between bats of the same species. Vibrating membranes in a bat’s larynx produce echolocation pulses. The sounds are released through the nose or the mouth, depending upon the species. The nose leaf that some species have may serve to channel the sound. Bats’ large external ears probably help detect the direction of incoming signals. The middle and inner ears are specialized for high-frequency sensitivity. The frequency, frequency pattern, duration, repetition rate, intensity, and direction of the pulses vary with family and even with species. When fully active, bats have a body temperature of about 98.6 °F (37 °C). Although some bats maintain fairly even body temperatures, a large number are able to lower their temperature to that of their surroundings shortly after coming to rest. They raise their temperature again when done resting or when readying themselves for nightly feedings. A drop in body temperature results in a lethargic state. Energy is conserved, though the bats are relatively unresponsive to threats by predators or weather. Many of these same bats also hibernate during the winter. In the fall they increase their weight by 50 to 100 percent. They migrate from the summer roost to a suitable hibernation site (often a cave) that will remain cool and humid throughout the winter without freezing. Details of the life cycle are known for only a few species. In bats that live in mild northern zones, birth takes place between May and July. Almost all mating within a group of bats occurs within a few weeks. The periods of gestation (the time between conception and birth), birth, lactation (the time during which the female feeds the young with her milk), and weaning also usually happen at the same time. Gestation varies from five or six months in some species to 6 or 7 to 14 weeks in several smaller types. The length of gestation may be influenced by both outside temperature and body temperature. Most bats bear one young, called a pup. At birth the pups, which may weigh from one-sixth to one-third as much as the mother, usually have well-developed hind legs. They use these to hold on to their mother or to the roost. Their wings are immature, and they are often briefly blind and deaf. The pups are nourished by milk for a period of about five or six weeks in many small bats and for about five months in some larger species. Infant mortality appears to be high. Accidents seem to cause the most losses—the pups may fall from the ceiling or perhaps have serious collisions in early flight attempts. Adult bats, on the other hand, live a relatively long time. There are records of bats of several species that have lived for about 20 or 30 years. Probably many bats in mild climates live more than 10 years. Isolated roosts and nighttime flight substantially protect the bats from predators, which include owls, hawks, and snakes. Many bat species are enormously abundant. Observers have concluded, for example, that some 100 million female Mexican free-tailed bats (Tadarida brasiliensis mexicana) form summer nursery colonies in Texas. There they produce about 100 million young in five large caves. The adult males are equal in number to the females. Thus, one species alone numbers, at the very least, in the hundreds of millions. Not all species are that prevalent, however. Some have been overhunted for their meat. Others, especially tropical forest species, have fallen victim to loss of habitat. Diseases also play a part in the destruction of species. For example, white-nose syndrome affects hibernating bats in North America. It is caused by the growth of a white fungus in the skin of the nose and ears and in the membrane covering the wings. Biologists estimated that between 5.7 million and 6.7 million bats died from white nose syndrome—with some colonies experiencing declines of greater than 90 percent—in the first six years after its detection in 2006. These factors have led the International Union for Conservation (IUCN) to list more than 20 bat species as critically endangered and more than 50 as endangered in the early 21st century.
Science, Tech, Math › Science Beta Decay Definition Share Flipboard Email Print Paper Boat Creative / Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated October 13, 2019 Beta decay refers to the spontaneous radioactive decay where a beta particle is produced. There are two types of beta decay where the beta particle is either an electron or a positron. How Beta Decay Works β- decay occurs when an electron is the beta particle. An atom will β- decay when a neutron in the nucleus converts to a proton by the following reaction. Here X is the parent atom, Y is the daughter atom, Z is the atomic mass of X, and A is the atomic number of X:ZXA → ZYA+1 + e- + antineutrino β+ decay occurs when a positron is the beta particle. An atom will β+ decay when a proton in the nucleus converts into a neutron by the following reaction, where X is the parent atom, Y is the daughter atom, Z is the atomic mass of X, A is the atomic number of X:ZXA → ZYA-1 + e+ + neutrino In both cases, the atomic mass of the atom remains constant but the elements are transmuted by one atomic number. Practical Examples Cesium-137 decays to Barium-137 by β- decay.Sodium-22 decays to Neon-22 by β+ decay.
I will attempt to answer your question without any equations. What defines propulsion force of jet engine? Mass and speed of 'ejected' gasses and also surface the gasses will pushed against (atmosphere), minus air resistance created by engine on intake side (air sucked in but still engine creates some resistance). Theoretically we can push gasses faster by narrowing gas eject opening, but at some point we will reach critical velocity when gasses will have not enough surface to push against. Also we can not make intake opening too big -- resistance will start overtake efficiency at some limit value. Also we should take in account a mass of the jet engine -- more weight means more load on engine/wings and efficiency decreases (more fuel burnt to carry the engine itself). Force generated by jet engine is proportional to square speed of 'ejected gasses' multiplied by mass of 'gasses' itself [I=V^2M]. A balance should be achieved to make jet engine efficient. Two jet engines is less efficient than one due equation S=PiR^2 -- surface increases faster with increase of radius. Two or more engines increase reliability of flying craft -- but at expense of efficiency. Nowadays airplane can land with only one engine, it was put into design of air craft.
By Jeanette Senecal from the League of Women Voters Candidate debates have a long history in American politics. At every level of government—from city council to state legislature, from Congress to President of the United States—candidates participate in debates to help voters understand who and what they stand for. Watching debates is an important way for voters to learn more about the candidates and the issues before the election, so that they can cast an informed vote. At the same time, voters need to view debates with a careful eye to get the most information. Candidates rehearse thoroughly for debates, making it hard to get candid, spontaneous answers. Debates can emphasize form over substance, such as the candidates’ appearance instead of their stands on the issues. You may watch a debate and still not get answers to the questions you have about the candidates and issues. You can get the most out of a debate by thinking about the issues and candidates in advance, by viewing the debate with care, and by continuing to research the issues and the candidates after the debate. Debate Watching 101 provides background information and tips to help you get the most out of watching a candidate debate. What Is a Debate? A debate is an event at which candidates who are running for an elected office meet face-to-face to answer questions that are asked of them. This gives the candidates a chance to state their views and to respond to their opponents’ statements. It gives viewers a chance to directly compare the candidates and their positions. Debates usually take place in front of a live audience and may also be televised or broadcast on the radio or the Internet. A televised or broadcast debate allows many more people to watch and learn about the candidates and issues. Debates can follow different formats, or a combination of formats. The most common formats are: - Single moderator: one moderator asks the questions; - Panel: a panel of journalists or experts questions the candidates; - Town hall: questions are submitted by members of the audience or randomly selected voters, in person or by phone or email. The Town Hall format allows for questions to be submitted in advance or during the debate. The debate usually begins with an introduction of the candidates, who may also be given time to make opening statements. The heart of the debate takes place when the candidates are asked questions and they respond. There usually is a time limit for responses. The questioner may ask follow-up questions to get the candidates to explain or clarify their responses. Some debates give candidates an opportunity to “cross-examine” or ask questions directly of each other. At the end of the debate, the candidates are usually given time to make closing statements. Before the Debate Thinking about and preparing for the debate before it takes place will enable you to get the most from watching it. It will familiarize you with the candidates and issues. The preparation will help you focus on what to look for in the debate so that you will get the information you need in deciding who to vote for. It will help if you take some time before the debate to: - Follow the campaign to learn about the candidates and their backgrounds; - Find out what the important campaign issues are; - Decide what issues are most important to you; - Think about the questions you may have and the information you want to get from the debate to help you in your decision making; - Open your mind to new opinions/impressions of the candidate regardless of party affiliation. You may want to make plans to get together with friends or family to watch the debate. Watching the debate in a group and discussing it afterwards helps to clarify your thoughts about what was said in the debate and how the candidates performed. A debate might not include all of the candidates for the office. Before the debate, note which candidates are included and which are not. If all candidates are not participating, try to find out why. Some debates include only candidates who have significant support, on the theory that the voters should be able to compare the candidates with a realistic chance of winning. Others invite all candidates who have qualified for the ballot. Sometimes candidates who are invited choose not to participate. Candidates with a strong lead might refuse to participate because they think there is no advantage to be gained by debating a lesser known opponent. During the Debate When watching the debate, ask yourself questions like these to help you judge the fairness of the debate and the performance of the candidates. >The debate format and questions: - Does the format give each candidate an equal opportunity to speak and respond to questions? - Are the questions clear, fair and equally tough on all candidates? - Do the questions cover the issues that are important to you? - Is the moderator in control of the debate? Does the moderator need to say less and let the candidates say more? - Do they answer questions directly, or do they evade them or fail to answer the specific question? - Do they give specifics about their stands on the issues, or do they speak in generalities? Do they support their positions and arguments with facts and figures? - Do they talk about their own policies and positions, or do they mostly attack their opponents? - Are their proposals realistic? Can they actually carry out the promises they are making? - Do they appear sincere, confident and relaxed? - Do they show how their backgrounds and experience qualify them to hold the office? - Are their answers consistent with their previous positions, and if not, do they explain why? - What image are they trying to create? - Do their responses appear overly rehearsed or “canned”? - If you are watching the debate on television, are reaction shots or other techniques used to create a sense of drama or conflict? - Are you being influenced by comments made by reporters and commentators immediately before and after the debate? After the Debate It will help clarify your thoughts about the candidates and the issues if you take some time after the debate to reflect on what you have just seen and heard. You can do this by: - Comparing your impressions with others who watched the debate; - Asking yourself, based on the information you got from watching the debate, which candidate appears most qualified for the office; - Identifying the issues on which you agree with a candidate and those on which you disagree, and deciding whether that makes you more or less likely to vote for a particular candidate; - Asking yourself if you learned something new about the issues or the candidate; - Thinking about whether you have more questions about the issues or the candidates that you want to follow up; - Getting more information about the candidates’ positions from news reports, candidate Web sites and nonpartisan voter information Web sites such as VOTE411.org. - Watch later debates for more information or to confirm your current impressions of the candidates Candidate debates give voters a chance to hear the candidates speak and respond to their opponents. They give candidates a chance to present their message directly to a wide audience. As a voter, asking yourself the right questions before, during and after the debate can help you make the most of this opportunity to learn about the candidates and the issues. © League of Women Voters Education Fund 2006
The most common modes of administration can be summarized as: There are several different designs, or overall structures, that can be used in survey research. The three general types are cross-sectional, successive independent samples, and longitudinal studies. In cross-sectional studies, a sample or samples is drawn from the relevant population and studied once. A successive independent samples design draws multiple random samples from a population at one or more times. Such studies cannot, therefore, identify the causes of change over time necessarily. For successive independent samples designs to be effective, the samples must be drawn from the same population, and must be equally representative of it. If the samples are not comparable, the changes between samples may be due to demographic characteristics rather than time. In addition, the questions must be asked in the same way so that responses can be compared directly. Longitudinal studies take measure of the same random sample at multiple time points. Longitudinal studies are the easiest way to assess the effect of a naturally occurring event, such as divorce that cannot be tested experimentally. However, longitudinal studies are both expensive and difficult to do. This attrition of participants is not random, so samples can become less representative with successive assessments. To account for this, a researcher can compare the respondents who left the survey to those that did not, to see if they are statistically different populations. Respondents may also try to be self-consistent in spite of changes to survey answers. Questionnaires are the most commonly used tool in survey research. However, the results of a particular survey are worthless if the questionnaire is written inadequately. A variable category that is often measured in survey research are demographic variables, which are used to depict the characteristics of the people surveyed in the sample. Reliable measures of self-report are defined by their consistency. It is important to note that there is evidence to suggest that self-report measures tend to be less accurate and reliable than alternative methods of assessing data e. Six steps can be employed to construct a questionnaire that will produce reliable and valid results. The way that a question is phrased can have a large impact on how a research participant will answer the question. A respondent's answer to an open-ended question can be coded into a response scale afterwards, or analysed using more qualitative methods. Survey researchers should carefully construct the order of questions in a questionnaire. The following ways have been recommended for reducing nonresponse in telephone and face-to-face surveys: Brevity is also often cited as increasing response rate. A literature review found mixed evidence to support this claim for both written and verbal surveys, concluding that other factors may often be more important. Survey methodologists have devoted much effort to determining the extent to which interviewee responses are affected by physical characteristics of the interviewer. Main interviewer traits that have been demonstrated to influence survey responses are race, gender, and relative body weight BMI. Hence, race of interviewer has been shown to affect responses to measures regarding racial attitudes, interviewer sex responses to questions involving gender issues, and interviewer BMI answers to eating and dieting-related questions. The explanation typically provided for interviewer effects is social desirability bias: Interviewer effects are one example survey response effects. From Wikipedia, the free encyclopedia. There are many different types of surveys, several ways to administer them, and many methods of sampling. There are two key features of survey research:. The two most common types of survey questions are closed-ended questions and open-ended questions. Double-Barreled Question Pretesting Questionnaire. One of the primary strengths of sampling is that accurate estimates of a population's characteristics can be obtained by surveying a small proportion of the population. Four sampling techniques are described here:. For example, in a face-to-face interview, it is difficult and expensive to survey households across the nation. Instead, researchers will randomly select geographic areas for example, counties , then randomly select households within these areas. This creates a cluster sample, in which respondents are clustered together geographically. For example, a researcher may want to compare survey responses of African-Americans and Caucasians. To ensure that there are enough Afrian-Americans in the survey, the researcher will first identify the African-Americans in the population and then randomly select a sample of African-Americans. Measurement error is the difference between the target population's characteristics and the measurement of these characteristics in a survey. There are two types of measurement error: For example, a researcher may administer a survey about marital happiness. However, some respondents may have had a fight with their spouse the evening prior to the survey, while other respondents' spouses may have cooked the respondent's favorite meal. The survey responses will be affected by the random day on which the respondents were chosen to participate in the study. With random error, the positive and negative influences on the survey measure balance out. Respondents should give informed consent before participating in a survey. In order for respondents to give informed consent,. It is absolutely imperative that researchers keep respondents' identities confidential. Setting Up the Research Data Collection Techniques in Qualitative Research Methods and Tutoring Solution Research Methods in Psychology: Certificate Program Research Methods in Psychology: Help and Review Introduction to Psychology: Browse by Lessons Interpersonal Therapy: Latest Courses Computer Science Network Forensics Computer Science Latest Lessons Getting Started with Study. Create an account to start this course today. Like this lesson Share. Browse Browse by subject. Upgrade to Premium to enroll in Psychology Research Methods in Psychology. Enrolling in a course lets you earn progress by passing quizzes and exams. Take quizzes and exams. Earn certificates of completion. You will also be able to: Create a Goal Create custom courses Get your questions answered. Upgrade to Premium to add all these features to your account! Email us if you want to cancel for any reason. Start your FREE trial. 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Password confirm does not match password. Unlimited access to all video lessons Lesson Transcripts Tech support. See all other plans. Streaming videos that cover every part of the exam, to help you get your best grade or score Download videos with ease Full transcripts of each lesson Unlimited practice tests —so you're completely confident on test day Mobile app —study anywhere 1-on-1 support from instructors. See all other plans See the Teacher's Edition. Don't worry, we'll email you right away with all the details You are free to cancel online, anytime, with just a few simple clicks And if you have any questions, you can reach out anytime. First Name Name is required. Last Name Name is required. Phone Number Don't worry. We won't call unless you want us to. Phone number is required. Phone number is invalid. Have a Coupon Code? Once your payment is confirmed through PayPal, you'll get automatically redirected to Study. You have not applied your coupon. You're on your way to a new account. Card Number Have a Coupon Code? Card number is required. Credit card number invalid. Please correct or use a different card. This card has been declined. Please use a different card. Prepaid cards not accepted. Expiration is not a valid, future date. Year Expiration Year is required. Zip Code Zip code is required. Secure Server tell me more. Price after trial Starting Price starting today. - Definition, Methods & Types This lesson explores the ways a researcher may employ the types of surveys used in research. We will also go over the strengths and weaknesses of each type of survey. Survey method pursues two main purposes: Describing certain aspects or characteristics of population and/or; Testing hypotheses about nature of relationships within a population. Survey method can be broadly divided into three categories: mail survey, telephone survey and personal interview. Survey Research Survey research is one of the most important areas of measurement in applied social research. The broad area of survey research encompasses any measurement procedures that involve asking questions of respondents. Survey research is a commonly used method of collecting information about a population of interest. There are many different types of surveys, several ways to administer them, and many methods . The survey is a non-experimental, descriptive research method. Surveys can be useful when a researcher wants to collect data on phenomena that cannot be .
What is renovascular disease? The kidneys filter blood and remove waste from your body through the form of urine, which collects in your bladder and exits your body when you urinate. The kidneys also help to control your blood pressure (BP) by secreting a hormone called renin into your bloodstream. The renal arteries and renal veins supply the kidneys. Renovascular disease is a condition that affects these blood vessels of your kidneys. The blood vessels may become narrow or blocked due to blood clots or plaque buildup and lead to renal vein thrombosis or renal artery stenosis respectively. What causes renovascular disease? Renal vein thrombosis can result due to a blood clot, nephrotic syndrome (high levels of albumin protein excreted through urine), presence of a tumor, infection or injury to the vein. Renal artery stenosis is a condition characterized by hardening of the kidney arteries, which is caused due to the accumulation of a sticky substance (cholesterol, calcium or fibrous tissue) called plaque on the walls of the artery. Obesity, smoking, high cholesterol levels and diabetes are some of the risk factors that increase your chances of renovascular diseases. What are the symptoms of renovascular disease? Renovascular conditions progress slowly over time and may not cause noticeable symptoms initially. Symptoms may include elevated blood pressure, decreased kidney function and a whooshing sound in the abdomen heard with a stethoscope. Blood clots in the renal veins rarely affect the kidneys, but can travel to healthy blood vessels and blockage the flow of blood. The blood clot can travel to arteries that lead to the lungs, resulting in a serious condition called pulmonary embolism, or to other arteries. This may cause symptoms such as pain in legs, thighs and sides of your abdomen, protein or blood in urine, fever, vomiting, nausea, swelling in your legs and difficulty in breathing. How is renovascular disease diagnosed? When you present to the clinic with any of these symptoms, your doctor may suggest the following imaging tests to help determine renovascular disease: - Ultrasound: uses sound waves to create images of the blood vessels - CT scan: uses X-rays to create images of cross-sections of the blood vessels - MRA scan: uses magnetic fields to image blood vessels - Radionuclide scanning: uses radioactive chemicals for imaging - Angiography: uses a special dye in the blood vessels, which can be detected by X-rays - Venacavography: a form of angiography that takes images of the main abdominal veins How is renovascular disease treated? Based on the severity of your condition, your physician may recommend the following treatment options: - Medication: You may be advised to take BP lowering medications to keep your BP under control. - Thrombolysis: An anticoagulant or clot-dissolving medication may be directly injected into the blood clot through a catheter (a long, thin tube) inserted in the groin. - Angioplasty and stenting: Your doctor inserts a catheter through a small incision in the groin and guides it through to your renal artery. The catheter carries a tiny balloon that is inflated at the site of the plaque blockage to flatten it against the walls of your artery. Your doctor may insert a stent (tiny metal-mesh) in the artery to hold the blood vessel open and prevent it from collapsing. - Surgery: There are 2 surgical procedures to treat renovascular disease. Your surgeon may suggest renal endarterectomy, in which the plaque is removed from the inner wall of your renal artery leaving behind a wide-open artery. Bypass surgery is another procedure that may be recommended, in which your surgeon re-routes blood flow around the narrowed or blocked section of your renal artery by using a graft. The graft is attached above and below the blockage, creating a new path for the blood to flow through. How can I prevent is renovascular disease? You can prevent renovascular diseases by eating a balanced diet, maintaining a healthy body weight, quitting smoking, exercising regularly and keeping cholesterol and blood pressure levels under control.
Teach any Normans topic, no prep needed! Do you want to save dozens of hours in time? Get your evenings and weekends back? Be fully prepared to teach any Normans KS3 topic? Every Normans topic is covered, and each module comes complete with: KS3 Normans Resources The Normans were a group of people from Normandy, northern France, who had lived there since prehistoric times and into the Viking era. The duchy of Normandy emerged around 900 A.D. In 1066, it belonged to the Duke of Normandy known as William the Conqueror. He invaded England after Edward the Confessor died without any heirs. William believed himself to be a rightful claimant to the throne but King Harold II had himself crowned king instead. Harold’s Saxon army and William went head to head in the Battle of Hastings on October 14 1066. With Harold killed in the battle, William was able to secure his right as king and was crowned on December 25 1066. He implemented many changes in England and resistance was met with a heavy hand – the most notable being the Harrying of the North. Learn more about who the Normans were, Norman history from the founding of Normandy to the conquest of England, and the impact of the succession crisis after the death of Edward the Confessor with our KS3 resources. You’ll find Student Activities, Lesson Presentation, and Revision Notes ready to download below. KS3 resources are ideally suited for Years 7, 8 and 9, or ages 11-14.
Grade 2 Science Tutoring & Help Our Grade 2 science help will get students excited about studying science while also teaching them a number of other valuable skills. Although children are known to have natural curiosity, not all of them are the same. Some kids are excited by science while others have a harder time connecting with it. For the kids in the latter category, their slipping grade in science may reflect a need for more one-on-one attention. That’s why Oxford Learning®’s Grade 2 science help is here. Your child’s tutor will not only make sure he or she keeps up the grade, but also approaches science with more confidence and enjoyment. What makes Oxford Learning® different? It’s our quality approach to science instruction. With our help, students not only improve on their Grade 2 science, they also learn a host of other valuable skills including learning to follow direction, focusing and paying attention, planning and confidence development. Grade 2 Science Tutoring Subjects Growth and Changes in Animals - Animals and human characteristics - Similarities and differences among various kinds of animals - Human protection of animals and animal habitats - Spatial relationships - Stationary and moving objects - Simple machines that help objects to move - How machines make human lives more enjoyable and easier to live Liquids and Solids - Different properties of liquids and solids - Different reactions of liquids and solids - Environmental harm Air and Water in the Environment - Air and water as part of the environment - Living things dependency for survival - How human actions can affect the quality of water and air
10th April 2019 Welding a fuel tank might seem like a relatively simple and cheap process, especially when compared to the cost of a replacement tank. However, many factors make welding a tank with residual oil, diesel or petrol dangerous. Welding on a tank is the process of sealing a crack or split in its surface by heating the metal so that it rebinds together. Forming a strong joint that will no longer allow fuel to escape. The high heat and reaction taking place during this welding process, however, are unpredictable. To control the reactivity of welding a tank you can fully empty a tank and clean it out prior to filling it with a noble gas. Whilst we don’t recommend welding any fuel tank there are certain elements to consider when undertaking a project like this if you do need to weld it. Firstly, the volatility of some fuels can be much higher than others. This is entirely true of petrol and its fuel vapours. A partially filled fuel tank, with air left in the tank will be full of vapourised gases. These fuel gases, when exposed to a spark or flame, will ignite more aggressively than if they were liquid. Much like a fuel air bomb, the extra oxygen in contact with the petrol allows for faster burning of the fuel. This makes welding a petrol tank extremely dangerous to the user and the tank. Argon is the most commonly used of the inert gases in gas tank welding to stop any reaction from taking place. This lazy gas, like all the noble gases, is colourless and odourless. Argon is also used in the manufacture of fluorescent lighting. There are multiple tools for welding a tank including TIG and MIG welders. They are similar methods with slightly different qualities and deciding which one to use is tough. Which gas metal arc welding method to use depends on the materials being used. Metal inert gas (MIG) welding is a method of welding that utilises a filling metal. This metal doubles as the electrode used to heat the target pieces. MIG welders are better at bonding thicker metals as it can join the two materials with an integrated filler. This allows a strong connection to form without heating the metal thoroughly. As the welding starts the filler material melts into the welding pool whilst shielding gas protects the weld. By keeping the oxygen content low near the joint the welding machine prevents impurities from getting into the joint that might weaken it. Tungsten inert gas (TIG) welding uses a fixed pure tungsten electrode to heat the joining metal. A filler rod, made of a recommended type of metal, is then carefully introduced into the weld pool to fill the join. Manipulating a rod by hand rather than being machine fed on a MIG welder makes TIG the slower method and requires both hands. For sheet metal, using TIG makes controlling heat levels easier, therefore preventing the base and weld metal from melting too much. These are generally the tougher materials to weld. Although it’s unlikely you’ll find a stainless steel tank for bulk fuel, I’ll cover it along with aluminium/aluminum. The first thing to do is to identify exactly what grade of material you are working with. Stamped onto the metal, there will be a number that will relate to what kind of filler rod to use. After you have your materials ready, check your gas levels against the thickness of your target metals. As your aluminium reaches over half an inch thick you’ll want to add helium to your argon to raise the arc temperature and improve the penetration of the join. You’ll also need to consider the thickness of the tank. Generally, about an eighth of an inch will require around 125 amps. Sign up to our newsletter to be the first to hear about our latest products, special offers and expert advice.
What is it? X-rays use a small amount of radiation to take internal images of the body of film like a camera. Our radiologists have advanced x-ray and flouroscopy technology that provide diagnostic assistance for a wide range of film imaging. Diagnosing broken bones, pneumonia, etc. Mammograms are a common type of X-ray used to help diagnose breast cancer. You may be asked to lie still on an X-ray table or sit or stand by the table. You may wear a lead apron to protect certain parts of your body. What you need to know - Procedures vary according to the examination purpose of the x-ray. - For instance, an x-ray for your large intestine is taken in conjunction with a barium enema. Preparations for this exam differ from an Upper GI Series which involves imaging the esophagus, stomach, and a portion of the small intestines during which you're asked to sip a barium "cocktail". For an intravenous pyelogram (IVP), an injected "contrast medium" is used to highlight areas of the kidneys, ureters, and the urinary bladder. - The length of time for each of these examinations can vary from 45 minutes to an hour.
April 15th, 2015 Its name is Kairuku (“diver who returns with food,” in Maori) and lived 25 million years ago in New Zealand. It was the tallest among five species of penguins in the region, with a height of more than 1.2 meters (4 feet 2 inches). Researchers have reconstructed it from two different fossils collected in 1977, as described in the Journal of Vertebrate Paleontology. “Kairuku was an elegant bird by penguin standards, with a slender body and long flippers, but short, thick legs and feet,” says Dr Daniel Ksepka, researcher at the North Carolina State University and co-author of the study. “If we had done a reconstruction by extrapolating from the length of its flippers, it would have stood over 6 feet tall [around 1.8 meters]. In reality, Kairuku was around 4-feet-2 inches tall or so.” This finding may help palaeontologists study giant penguins living in the Oligocene period (about 34 million to 23 million years ago). It is believed that New Zealand was “great for penguins in terms of both food and safety”, according to Ksepka. “Most of New Zealand was underwater at that time, leaving isolated, rocky land masses that kept the penguins safe from potential predators and provided them with a plentiful food supply.” It seems that New Zealand species, however, were not the biggest ones. In 2007 and 2010, scientists discovered in Peru two penguin species of about 1.5 meters (5 feet) tall, which lived 36 million years ago. Ksepka, D.T., R.E. Fordyce, T. Ando, & C.M. Jones (2012). New Fossil Penguins (Aves, Sphenisciformes) from the Oligocene of New Zealand Reveal the Skeletal Plan of Stem Penguins Journal of Vertebrate Paleontology
Humidity is the amount of moisture or water vapor in the air. Humidity is typically measured as relative humidity, or RH. RH is a percentage of moisture in air at a given temperature of the total moisture that the air could hold at that temperature. If the air cannot hold any more water without producing moisture as condensation, then the relative humidity of that air is 100%. If the air is only holding 1/2 of what it could before producing moisture, the relative humidity of that air is 50%. Water vapor in a home is produced by plants, animals, and people. Water vapor is added to the air with the activities of daily life – showering and bathing, doing laundry and dish washing, cooking and housecleaning, and more. Water vapor is also importantly determined by climate conditions and current weather. Humidity is a natural condition for comfort and health. However, too much or too little humidity will be adverse to our comfort and health. Too much or too little humidity will cause problems, for people and for furnishings. Signs of high humidity include condensation on windows, moldy bathrooms or basements, musty smell and allergic reactions. Signs of low humidity include chapped lips, scratchy nose and throat, and static electricity. We can feel humidity but to measure Relative Humidity, an instrument called a “hygrometer” can be used. They are not expensive and are easy to use. Make sure you follow operating instructions to get accurate readings. Hygrometers are often available at hardware stores. Getting some accurate readings with a hygrometer will help determine measures to take to increase humidity (with a humidifier for example) or to lower humidity. Humidity readings will vary in different areas – it can be higher close to windows, or in basements so take this into account when assessing overall humidity. Also, warmer air can hold more humidity than cooler air so RH readings will change when air temperature changes (if air is for example, hotter in afternoon, cooler in the mornings). So what is an appropriate humidity level? Typically an RH between 30-50%, closer to 30 in the cold season but if you have lots of plants, a hot tub or an indoor swimming pool, allow for RH on the higher side. If windows show condensation with RH levels of 30-40%, windows may need upgrading. What actions can be taken? Humidity can be controlled. If the humidity is too high it can be lowered. It the humidity is too low it can be increased. Humidity is usually lower in cold winter weather then in hot summer weather. Humidity can be reduced by using a dehumidifier and by running air conditioning (also consider running exhaust fans). Humidity can be increased by running a humidifier (stand alone unit or unit installed on heating/cooling system), or having more house plants for example. If low humidity persists in cold weather, weather stripping and caulking may be in order. Opening doors and windows will increase or decrease humidity depending on the relative humidity outside compared to the relative humidity indoors. If you install a dehumidifier or humidifier, follow operating and maintenance instructions to get and maintain good performance. Dehumidifiers should be placed in the areas with the highest relative humidity. Humidity will jump in rainy weather and in particular wet weather that causes flooding. In the case of flooding, air movement and de-humidification is particularly important and part of any professional flood water removal or flood restoration service. For more information on humidity control, or other household air conditions, call Ram Cleaning Services at 403-291-1051 and talk to one of our representatives. Complete Cleaning Care and Maintenance in Calgary and area since 1967 Tags: home humidity
As the Métis Nation continues to make gains on its self-government agenda, there is an increasing need to strengthen our national government. Métis citizens, communities, leadership, and assemblies have consistently urged for the development of a stronger national government structure which meets the unique needs of the Métis Nation. As well, increasingly over the past few years, the limitations of the Métis National Council’s current corporate structure have frustrated the Métis Nation in acting and operating as an Aboriginal government. Based on all of these factors, the Métis National Council is moving forward on developing a Métis Nation Constitution. What is a Constitution? Constitutions have been described as “a mirror reflecting the national soul” because they recognize and protect the values of a nation (Cheffins & Tucker, The Constitutional Process in Canada). Some Constitutions assert and protect the cultural, linguistic and regional diversity of the nation in question. Others provide fundamental protections to civil liberties and rights. But ultimately, a constitution can be defined as the supreme law of a nation. From a legal perspective, constitutional law is the law prescribing the exercise of power by the official bodies of a nation state. A Constitution explains which organs can exercise legislative power (making new laws), executive power (implementing the laws) and judicial power (adjudicating disputes), and what the limitations on those powers are (Peter Hogg, Constitutional Law). In a federal state, such as Canada, the allocation of governmental powers between federal and provincial authorities (also known as jurisdiction or responsibility) is also a subject matter within a Constitution.
Paleobiologsts study remains of extinct species no matter the size, distribution or age, to study the evolution of all biological life. What Does a Paleobiologist Do? A paleobiologist examines fossilized remains of dead biological life. Where paleontologists examine the fossilized remains of animal life, paleobiologists expand that scope to include any biological system. They may use microscopes to examine ancient plant microfossils (seeds, spores and pollen), phytoliths and individual cells where they exist, and mineralized deposits of full specimens. Most work on excavations and in the field. They can work in any environment and will have the same sort of skills as archeologists in excavation. Tools of the trade include trowels, brushes, tape measures, recording equipment (pens, pencils, cameras) and patience. They also understand elements of geology, including rock and soil properties. Increasingly, particularly for those who direct or manage excavations, they are expected to use remote sensing and surveying equipment and be able to interpret non-intrusive technology data such as ground penetrating radar. What their role is depends on a number of factors including qualifications, preference and specialism. Excavation is just one career option. Another option for qualified paleobiologists is lab work or desk based research. Testing sample to date them (using either absolute or relative dating methods) is one potential task. Others may produce and analyze distribution diagrams to understand the data in its wider context. The third career option is academia. Those with the relevant background and experience may choose to work in university departments to encourage the next generation of paleobiologists and paleontologists. They will apply for research grants and conduct research and excavation for universities while being under obligation to teach for using facilities. Where Does a Paleobiologist Work? Their flexible skills and usefulness means that the work environment of the paleobiologist is not limited purely to university departments. Many work as consultants or in excavation teams in oil and gas extraction. Their knowledge of geology and geological deposits is invaluable. Our fossil fuels are broken down organic material, so their background in paleobiology is vital for prospecting for new pockets of gas, coal and oil. Some 22% are employed in this area. Similarly, 17% will work in engineering services fulfilling much the same roles ahead of commercial, industrial or residential development but independently of government and private business. They may compile geological maps and GIS files for construction organizations. Around 15%, that is 1 in every 7, will work for independent technical consulting services. These private firms may be contracted by developers or government, but their knowledge base may provide the basis for academic reporting One in eight works in state government, for example in museums or other education establishments (but not public schools or universities). History clubs, state parks and other similar non-Federal government activities will come under this. The academic community employs around 7% of graduates with these qualifications. What Is the Average Paleobiologist Salary? According to data from May 2015, the media paleobiologist salary (including palaeontologists) is presently $89,700. Little data exists for paleobiologists in general, so details have been extracted from Geoscience data at BLS. The lowest 10% earned less than $47,520 and the highest 10% of earners had a salary and bonuses of more than $187,200. The highest paying sector was oil and gas extraction with a median salary of $129,550. Engineering came second but paid under the median at $80,180. Paying considerably less than median were Scientific & Technical at $73,840, state government at $69,790. Finally was education and academia paying $66,230. Paleobiology Jobs & Job Description Recent Paleobiology Job Listings Use the search box below to find all the paleobiologist job listings in our job board. A Paleobiologist's main job is to study how biological life has evolved over time. Working in the role requires a highly specialized set of skills and tasks could vary significantly based on place of employment. Working at a museum, a consulting firm or in the oil field are all opportunities that the role affords. The skills and tasks include but are not limited to: - A university degree in geology, earth sciences, paleobiology, paleontology or related field of study - Knowledge of how to conduct field studies in varying and occasionally extreme environmental and weather conditions - Ability to generate and measure stratigraphic section samples of the earth using heavy machinery - Ability to observe and characterize sedimentary rocks and establish the relationship between biological life and rock types or formations - Possess knowledge of applicable laws, codes and regulations, such as those regarding field research or specimen collections for museums - Capacity to document, store, preserve and organize the collections of field research - Willingness to analyze specimens and sections of the earth using microscopes in a laboratory - Organizational ability for fossils and biological specimens to allow for future researchers or curators to locate specimens - Conduct research and analyses from organized collections of specimens, samples and observations The work of a senior level Paleobiologist will vary depending on the place of employment, such as working in a museum, an educational institute or as an executive consultant. The skills and tasks required for a senior level position can include some of the skills listed in the junior or entry level Paleobiologist position and may also include: - A Ph.D. in geology, earth sciences, paleobiology, paleontology or related field of study - Managing collections of paleobiological research in museums - Managing research volunteers, staff and students during research projects - Administering training to staff and volunteers as well as developing training programs applicable to projects - Cataloguing and overseeing access to specimens and use of specimens from storage locations - Excellent communication and knowledge to instruct and teach individuals about paleobiology and various specimens collected - Capacity to develop educational programs and courses for a variety of audiences and students - Capacity to design all aspects of research projects, including but not limited to project budgets, field locations, staffing, equipment required and research methods used - Ready to provide expert support and consultation for oil drilling proposals and construction projects - Ready to provide advising to students at an academic level when teaching components of paleobiology at a university or college What Is the Job Demand for Paleobiologists? Paleobiology is a niche area so no specific data exists on job demand. However, their broad skills, being similar to most other geoscientists, means that they are broadly categorized with geologists, paleontologists, environmental engineers, geographers and so on. Job demand for this area is expected to grow by 10% between 2014 and 2024. As existing fossil fuel pockets dry up, it's important to streamline production in finding remaining extant pockets and to use technologies and techniques to improve extraction. With their geological knowledge, paleobiologists can expect that the majority demand will come from this area. What Are the Education Requirements to Become a Paleobiologist? High School students should focus on the sciences in order to be accepted onto a relevant degree program of study. Typically, biology, chemistry and geography will put students in good standing for studying a degree. Similarly at college, students should choose a major that focuses on this area - covering as much of the background study as possible. Geography or biology are great degree choices, as is geology. Minors should complement whichever course the student opts. Bachelor's degrees are enough for excavation jobs with the relevant background. However, these jobs are often low paid and very competitive. Master's degrees will be essential for most roles that are not excavation based. The deeper understanding, the use of technology and project work will be vital for your ongoing career. A bachelor's degree is simply not enough for this type of advanced or responsible role. Students who wish to develop in their career into desk based research, lab work and reporting will need a master's degree. Doctorates will be essential for academic research, teaching and high-level government or business roles - particularly those that involved decision-making or high-level advisory. No Master's Degrees exist for this study area, so students should continue to tailor their roles through geology departments or through biology. Paleobiology - Related Degrees What Kind Of Societies and Professional Organizations Do Paleobiologists Have? The following organizations are for paleobiology professionals. - Paleobiology Database: Less of an organization and more of a knowledge-sharing base, this small sub-discipline is still a growing area. International cooperation is needed to study the history of evolution of life on this planet. It's non-governmental and interdisciplinary. - The Paleontological Society: Covering paleontology, paleobotany and paleobiology, this is the world's largest and most prestigious membership organization for academics, researchers and knowledge sharing. They produce publications and offer short courses
Can you do math on the Linux command line? You sure can! In fact, there are quite a few commands that can make the process easy and some you might even find interesting. Let’s look at some very useful commands and syntax for command line math. First and probably the most obvious and commonly used command for performing mathematical calculations on the command line is the expr (expression) command. It can manage addition, subtraction, division, and multiplication. It can also be used to compare numbers. Here are some examples: Incrementing a variable $ count=0 $ count=`expr $count + 1` $ echo $count 1 Performing a simple calculations $ expr 11 + 123 134 $ expr 134 / 11 12 $ expr 134 - 11 123 $ expr 11 * 123 expr: syntax error <== oops! $ expr 11 * 123 1353 $ expr 20 % 3 2 Notice that you have to use a character in front of * to avoid the syntax error. The % operator is for modulo calculations. Here’s a slightly more complex example: participants=11 total=156 share=`expr $total / $participants` remaining=`expr $total - $participants * $share` echo $share 14 echo $remaining 2 If we have 11 participants in some event and 156 prizes to distribute, each participant’s fair share of the take is 14, leaving 2 in the pot. Now let’s look at the logic for comparisons. These statements may look a little odd at first. They are not setting values, but only comparing the numbers. What expr is doing in the examples below is determining whether the statements are true. If the result is 1, the statement is true; otherwise, it’s false. $ expr 11 = 11 1 $ expr 11 = 12 0 Read them as “Does 11 equal 11?” and “Does 11 equal 12?” and you’ll get used to how this works. Of course, no one would be asking if 11 equals 11 on the command line, but they might ask if $age equals 11. $ age=11 $ expr $age = 11 1 If you put the numbers in quotes, you’d actually be doing a string comparison rather than a numeric one. $ expr "11" = "11" 1 $ expr "eleven" = "11" 0 In the following examples, we’re asking whether 10 is greater than 5 and, then, whether it’s greater than 99. $ expr 10 > 5 1 $ expr 10 > 99 0 Of course, having true comparisons resulting in 1 and false resulting in 0 goes against what we generally expect on Linux systems. The example below shows that using expr in this kind of context doesn’t work because if works with the opposite orientation (0=true). #!/bin/bash echo -n "Cost to us> " read cost echo -n "Price we're asking> " read price if [ `expr $price > $cost` ]; then echo "We make money" else echo "Don't sell it" fi Now, let’s run this script: $ ./checkPrice Cost to us> 11.50 Price we're asking> 6 We make money That sure isn’t going to help with sales! With a small change, this would work as we’d expect: #!/bin/bash echo -n "Cost to us> " read cost echo -n "Price we're asking> " read price if [ `expr $price > $cost` == 1 ]; then echo "We make money" else echo "Don't sell it" fi The factor command works just like you’d probably expect. You feed it a number, and it tells you what its factors are. $ factor 111 111: 3 37 $ factor 134 134: 2 67 $ factor 17894 17894: 2 23 389 $ factor 1987 1987: 1987 NOTE: The factor command didn’t get very far on factoring that last value because 1987 is a prime number. The jot command allows you to create a list of numbers. Provide it with the number of values you want to see and the number that you want to start with. $ jot 8 10 10 11 12 13 14 15 16 17 You can also use jot like this. Here we’re asking it to decrease the numbers by telling it we want to stop when we get to 2: $ jot 8 10 2 10 9 8 7 5 4 3 2 The jot command can be useful if you want to iterate through a series of numbers to create a list for some other purpose. $ for i in `jot 7 17`; do echo April $i; done April 17 April 18 April 19 April 20 April 21 April 22 April 23 The bc command is probably one of the best tools for doing calculations on the command line. Enter the calculation that you want performed, and pipe it to the command like this: $ echo "123.4+5/6-(7.891.234)" \| bc 113.664 Notice that bc doesn’t shy away from precision and that the string you need to enter is fairly straightforward. It can also make comparisons, handle Booleans, and calculate square roots, sines, cosines, tangents, etc. $ echo "sqrt(256)" \| bc 16 $ echo "s(90)" \| bc -l .89399666360055789051 In fact, bc can even calculate pi. You decide how many decimal points you want to see: $ echo "scale=5; 4a(1)" \| bc -l 3.14156 $ echo "scale=10; 4a(1)" \| bc -l 3.1415926532 $ echo "scale=20; 4a(1)" \| bc -l 3.14159265358979323844 $ echo "scale=40; 4a(1)" \| bc -l 3.1415926535897932384626433832795028841968 And bc isn’t just for receiving data through pipes and sending answers back. You can also start it interactively and enter the calculations you want it to perform. Setting the scale (as shown below) determines how many decimal places you’ll see. $ bc bc 1.06.95 Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. scale=2 3/4 .75 2/3 .66 quit Using bc, you can also convert numbers between different bases. The obase setting determines the output base. $ bc bc 1.06.95 Copyright 1991-1994, 1997, 1998, 2000, 2004, 2006 Free Software Foundation, Inc. This is free software with ABSOLUTELY NO WARRANTY. For details type `warranty'. obase=16 16 <=== entered 10 <=== response 256 <=== entered 100 <=== response quit One of the easiest ways to convert between hex and decimal is to use bc like this: $ echo "ibase=16; F2" \| bc 242 $ echo "obase=16; 242" \| bc F2 In the first example above, we’re converting from hex to decimal by setting the input base (ibase) to hex (base 16). In the second, we’re doing the reverse by setting the outbut base (obase) to hex. Easy bash math With sets of double-parentheses, we can do some easy math in bash. In the examples below, we create a variable and give it a value and then perform addition, decrement the result, and then square the remaining value. $ ((e=11)) $ (( e = e + 7 )) $ echo $e 18 $ ((e--)) $ echo $e 17 $ ((e=e2)) $ echo $e 289 The arithmetic operators allow you to: + - Add and subtract ++ -- Increment and decrement / % Multiply, divide, find remainder ^ Get exponent You can also use both logical and boolean operators: $ ((x=11)); ((y=7)) $ if (( x > y )); then > echo "x > y" > fi x > y $ ((x=11)); ((y=7)); ((z=3)) $ if (( x > y )) >> (( y > z )); then > echo "letters roll downhill" > fi letters roll downhill or if you prefer … $ if [ x > y ] << [ y > z ]; then echo "letters roll downhill"; fi letters roll downhill Now let’s raise 2 to the 3rd power: $ echo "2 ^ 3" 2 ^ 3 $ echo "2 ^ 3" \| bc 8 There are sure a lot of different ways to work with numbers and perform calculations on the command line on Linux systems. I hope you picked up a new trick or two by reading this post. >> Source Link
September 22nd is World Rhino Day! There are many ways to celebrate this awesome animal. Why not play with your kids (or older students) a matching game “I Know a Rhino!” and teach them a bit about rhinos? Here are the complete instructions. - Print the .pdf below (two pages), if possible on card stock. Make sure students can’t see through the back of them. Laminate if possible. - Two squares in the handouts combine to form a complete sentence about rhinos. You have 18 squares that make 9 sentences. And you have two rhino head pictures. - Make one bundle of cards for each group of students (4-6). - Spread out the cards face down. - Each player turns over two cards. The goal is to match cards to make a correct sentence about rhinos. Sometimes the cards don’t match. - Turn them over again. It’s important to remember where each card is and what it says. It’s the next player’s turn. - If it’s a match, the player gets to remove those cards to his/her pile. - Continue to take turns, trying for matches. - When someone turns over the Rhino Head, the game is over! - Count who has the most cards. That’s the winner. Why end the game so suddenly? It will make students want to play more than once.
Heritable connective tissue disease: A disorder due to mutation of a gene responsible for connective tissue, the material that gives tissues form and strength. These mutations may change the structure and development of skin, bones, joints, heart, blood vessels, lungs, eyes, and ears. Some mutations also change how these tissues work. There are over 300 mutations affecting collagen, a protein found in skin, bone, cartilage, and all other connective tissues. Examples of heritable connective tissue disease include such conditions as Marfan syndrome, osteogenesis imperfecta, epidermolysis bullosa, Ehlers-Danlos syndrome.
If you’re anything like me, summertime is filled with countless hours outside. Whether it is swimming, hiking, boating, or running, I am constantly soaking in the sun’s rays to hopefully get that desired golden tan. However, I recently vacationed in Lake Powell and, while I came back with a nice tan, my mom came back looking more like a lobster. Besides not applying enough sunscreen, what caused my skin to tan and my mom’s to burn? The sun emits ultraviolet light rays that can penetrate the cells that make up our skin and cause damage to our DNA. Suntans form as a result of defensive mechanisms that protect us from the harmful effects of ultraviolet light. This mechanism primarily operates through a pigment called melanin, which absorbs ultraviolet light and releases it in the form of heat. Melanin is produced by special skin cells called melanocytes. As the body is exposed to the sun, the melanocytes produce more melanin. The accumulation of melanin in the skin results in a golden-brown coloration, which we recognize as a suntan. When our melanin defenses get overwhelmed, ultraviolet rays enter the skin cells and damage their DNA. In response, the body releases special proteins called prostaglandins which causes blood to enter into the area. Prostaglandins also cause inflammation and pain, which are common characteristics of sunburns. However, prostaglandins usually do not form until four to six hours after the sun exposure. Therefore, sunburns don’t appear until long after we were exposed to the sun. As blood enters the area affected by ultraviolet light, it creates the lobster-red skin pigmentation that we are all too familiar with. With the blood accumulated in a single area, it also increases the skin temperature in the sunburn. Even though our body has defense mechanisms in place to prevent DNA damage through ultraviolet light, sometimes damage still occurs. To prevent further harm, the body has a failsafe that requires the damaged cells to die. This failsafe is called apoptosis. The accumulation of dead cells creates the layer of dead skin that peels off after a sunburn. When ultraviolet rays penetrate a cell, it causes DNA damage. DNA is composed of four different building blocks called nucleotides. These nucleotides are adenosine, thymine, guanine, and cytosine. Adenosine always binds to thymine and guanine always binds to cytosine. However, ultraviolet light breaks the chemical bonds the hold these nucleotides together and forms thymine dimers. Thymine dimers occur when two thymines bind together, which ruins the shape of the DNA molecule and makes it so it no longer functions correctly. DNA is essentially a blueprint to make you. It codes for just about everything to include your eye color, hair color, and height. DNA exists in every cell of our bodies, but, in order for it to be effective, it needs to be able to do its job. DNA codes for proteins, which make up your entire body. Without the right structure, it causes the DNA to encode for the wrong proteins and sometimes it prevents the cell from undergoing apoptosis. This results in skin cancer and the cell continues to divide and make new cancer cells. As the cells divide, they create tumors. Tumors can continue to grow and eventually move to other places in the body if not treated in time. If you would like to learn more awesome weather information, visit our website weatheregg.com. Resources: https://www.scientificamerican.com/article/what-happens-when-you-get/, https://www.livescience.com/38039-what-causes-sunburns.html, https://www.livescience.com/38039-what-causes-sunburns.html Image Resource: Featured Image https://pixabay.com/en/vacation-beach-relax-travel-sun-2218989/, https://commons.wikimedia.org/wiki/File:Tan_lines_on_human_female_chest.jpg, https://commons.wikimedia.org/wiki/File:Sunburn_flickr_02.jpg#/media/File:Sunburn_flickr_01.jpg, https://www.flickr.com/photos/32409122@N04/3042882960/in/photolist-5CTz6j-7k5UHm-5EbKEB-iwK6x-L1iEs-52skaS-9bk7CS-8qEomW-8VQhF9-9h4zua-2PchrU-4JAj3z-bVqoVE-av949a-34UHNG-6g4qKS-8eGpeA-7NSfhp-7BE6N7-6q9Zo7-wvmr-8VbQ2w-6NfDg5-a7dCa-81QWzm-9jY1ej-c1Z9NY-5jL6qw-3wTrrA-9bgZ5K-5gdzoh-7QV2vb-7TYPch-ZdnDpe-4o1ZUz-g1HVf-2NMA9D-Rc9pZ-5rSvUz-nFrFcj-7rvs6f-6k4D7x-5BsU8W-5DoDU-CAsEL-cpo7io-CJ8vF-kinuj-CJ8fY-z1EfHT
A biopsy is the removal of tissue from any part of the body to examine it for disease. Some may remove a small tissue sample with a needle while others may surgically remove a suspicious nodule or lump. - The tissue samples can be taken from any part of the body. The tissue is removed by placing a needle through the skin (percutaneously) to the area of abnormality. - Biopsies can be safely performed with imaging guidance such as ultrasound, x-ray, computed tomography (CT), or magnetic resonance imaging (MRI). These types of imaging are used to determine exactly where to place the needle and perform the biopsy. Purpose of Biopsy Biopsy are done for cancer screening. There are following condition :- - When a mammogram shows a lump or mass, indicating the possibility of breast cancer. - When a mole on the skin has changed shape recently and melanoma is possible. - A person has chronic hepatitis and it’s important to know if cirrhosis is present. - A needle biopsy can help identify whether there is an infection, and what type of organism is causing it. - By examining the cells in, for example, a needle biopsy, the doctor may be able to determine what is causing the inflammation. Types of Biopsies Here are some types of biopsies: - Needle biopsy: A needle biopsy is a procedure to obtain a sample of cells from body for laboratory testing. Common needle biopsy procedures include fine-needle aspiration and core needle biopsy. - CT-guided biopsy: A CT guided biopsy is an interventional procedure which involves the insertion of a biopsy needle into the body in order to collect a tissue sample from the area of interest. - Ultrasound-guided biopsy: An ultrasound-guided needle biopsy is an outpatient procedure to obtain a tissue sample of an abnormality discovered on a radiology scan. This is one type of “image-guided” biopsy, which combines the use of ultrasound with either a Fine Needle Aspiration or Core Needle Biopsy. - Bone biopsy: A bone biopsy is a procedure in which bone samples are removed (with a special biopsy needle or during surgery) to find out if cancer or other abnormal cells are present. A bone biopsy involves the outer layers of bone, unlike a bone marrow biopsy, which involves the innermost part of the bone. - Bone marrow biopsy: A bone marrow biopsy is part of a bone marrow test that takes a sample of solid bone tissue. A large needle is used to enter the pelvis bone to collect bone marrow. This detects blood diseases such as leukemia or lymphoma. - Liver biopsy: A liver biopsy is a procedure in which a small needle is inserted into the liver to collect a tissue sample. This is performed as an office or outpatient procedure or during surgery. The tissue is then analysed in a laboratory to help doctors diagnose a variety of disorders and diseases in the liver. - Kidney biopsy: kidney biopsy is a medical procedure in which a small piece of kidney is removed from the body for examination, usually under a microscope. Microscopic examination of the tissue can provide information needed to diagnose, monitor or treat problems of the kidney. - Aspiration biopsy: Fine needle aspiration is a type of biopsy procedure. In fine needle aspiration, a thin needle is inserted into an area of abnormal-appearing tissue or body fluid.A fine needle aspiration is most often done on swellings or lumps located just under the skin. - Prostate biopsy: For a prostate biopsy, a thin needle is inserted through the rectum (transrectal biopsy), through the urethra, or through the area between the anus and scrotum (perineum). A transrectal biopsy is the most common method used. - Skin biopsy: A skin biopsy is a procedure in which a sample of skin tissue is removed, processed, and examined under a microscope. Several different methods may be used to obtain a skin sample, depending on the size and location of the abnormal area of skin, called a skin lesion. - Punch biopsy: A punch biopsy is a medical procedure that acquires tissue for laboratory examination, usually through tissue culture or microscopy, by taking a punch-size piece of skin from the body. - Surgical biopsy: Types of surgical biopsies. With an excisional biopsy, the whole abnormal area (plus some of the surrounding normal tissue) is removed. In certain cases, an incisional biopsy is done. This procedure only removes part of the tumor. Risk:- Any medical procedure that involves breaking the skin carries the risk of infection or bleeding. However, as the incision is small, especially in needle biopsies, the risk is much lower. - A straightforward result may be ready within 2 to 3 days, but a more complex case may take 7 to 10 days.The tissue samples are sent to the lab and examined by a pathologist. They may be chemically treated and sliced up into very thin sections. They are usually studied under a microscope. A blood specialist, or hematologist, may also study the sample. - The thin slice is attached to a glass slide, and remaining tissue is usually saved for later studies. Sometimes the slide has dyes added to it. These stain the tissue, and this helps the pathologist see the cells more clearly. - In cases of cancer, the pathologist will need to determine whether the sample is malignant, meaning cancerous, or benign. If it is malignant, they will assess how aggressive or advanced the cancer is. If it is cancer, there are special stains that can be done to help guide treatment and prognosis. - Finally, the pathologist prepares a report that includes any abnormal or important findings. This report is sent to the doctor who ordered the biopsy. Is it painful? Yes sometimes it can be painful. If anaesthesia is used, there should be no pain during the procedure, although there will be a skin prick during the initial injection.In a needle biopsy, a pin prick will be felt and a sharp pinch.
\|Bonobos at the Cincinnati Zoo\| The bonobo (Pan paniscus) is a great ape and the smaller of the two species making up the genus Pan (the other is Pan troglodytes, the common chimpanzee). The bonobo is sometimes called the dwarf or pygmy chimpanzee. Although the name "chimpanzee" is sometimes used to refer to both species together, it is usually understood to mean the common chimpanzee, while Pan paniscus is usually referred to as the bonobo. The bonobo has high levels of sexual behavior. Sex functions in conflict appeasement, affection, social status, excitement, and stress reduction. It occurs in virtually all partner combinations and in a variety of positions. This may explain the lower levels of aggression in the bonobo as compared to the common chimpanzee and other apes. Bonobos are matriarchal and a male's rank in the social hierarchy is often determined by his mother's rank. The two chimpanzee species are separated by the huge Congo River. Its formation 1.5–2 million years ago may have led to the speciation of the bonobo. Their population is between 29,000 and 50,000 individuals. The species is listed as Endangered on the IUCN Red List. It is threatened by habitat destruction, human population growth and commercial poaching. The bonobo lives for about 40 years in captivity, though its lifespan in the wild is unknown. References[change \| change source] - Groves, Colin; Wilson D.E. and Reeder, D.M. (eds) 2005. Mammal species of the world. 3rd ed, Johns Hopkins University Press, 183.ISBN 0-801-88221-4 - de Waal, Frans; Lanting, Frans 1997. Bonobo: the forgotten ape. University of California Press. ISBN 0-520-20535-9. - Rowe N. 1996. Pictural guide to the living primates. Pogonias Press, East Hampton.ISBN 0-9648825-1-5
- The brain has electric charge. - The brain has a charge density. - The brain decreases in size over time. - Charge density increases if charge stays the same. The charge has two sources: internal and external. But there is a limit to the amount of charge that the brain can contain. And as charge density increases the limit decreases. Total signal= Internal + External Sensory data input are electrical signals from the external world. There is also an internal source of electricity. But if there is a limit to the amount of charge the brain can have at any one time, and the internal source of charge increases [due to a change in volume], the brain may limit the other inputs to regulate this charge. In the case of aging, the body may gather more signals to counter the lack of signal sensitivity. I’m sure you’ve heard that the ears and nose don’t stop growing. This is likely why. As the brain shrinks, it needs more and more molecules or vibrations to make a distinguishing identification. Note: The eyes do not and cannot grow because they are a source of charge. Not just a signal, but also electric charge.
A new study has identified a squid that broods its eggs–an uncommon characteristic for an invertebrate. Most invertebrates don’t provide any parental care for eggs or young, but the females of a squid species found in northern Japan do just that. They brood their eggs in their arms and presumably carry them around for months. This behavior has been observed many times since the early 1990s, but, until now, the species remained a mystery. The study, led by a group of Japanese scientists, identified the squid as Gonatus madokai. This is the third squid species now known to brood. In order to identify the species, the research team photographed and collected females, their eggs and their hatchlings and then analyzed tissue samples from two of the brooding females. The length of the brooding period is unknown, “but the females presumably brood the eggs for at least several months,” John Bower, the study’s lead author, told MST. During this period, she gets very weak. Bower explained that “the eggs presumably remain attached to six of the eight arms, which means the females cannot feed during the brooding period.” It is still unclear why the females of these three species would spend so much time and energy on their eggs, but the authors suggest that it likely increases the fitness of her offspring by protecting them from predators and harsh conditions. “More brooding squids await discovery, especially in the deep sea,” Bower said. Hopefully they will provide more clues to this fascinating behavior. To learn more: - Find the study, published in The Biological Bulletin, here: Brooding in a Gonatid Squid off Northern Japan - And read about the cover image Copyright © 2013 by Marine Science Today, a publication of Marine Science Today LLC.
OOPS Assignment Help Object-oriented programming is specified as a technique that offers a method of modularizing programs by producing separated memory location for both information and functions that can be utilized as design templates for developing copies of such modules as needed. Hence, a component can be thought about a different memory location which shops information and set of operations that can access that information. Because these components are independent they can be utilized in numerous programs without customizing them. Object-oriented programming (OOP) describes a kind of computer system programming (software application design) where developers specify not just the information kind of an information structure, however likewise the kinds of operations (functions) that can be used to the information structure. In this method, the information structure ends up being an object that consists of both functions and information. In addition, developers can develop relationships in between one object and another. Objects can acquire attributes from other objects. The core of the pure object-oriented programming is to develop an object, in code, that has particular buildings and approaches. While creating C++ modules, we attempt to see universe through objects. An automobile is an object which has specific buildings such as color, number of doors, and the like. It likewise has particular approaches such as speed up, brake, and so on. Compared to procedural programming, a shallow evaluation of code composed in both designs would expose that object oriented code has the tendency to be broken down into huge varieties of little pieces, with the hope that each piece will be trivially proven. OOP was one action to the holy grail of software-re-usability, although no brand-new term has actually acquired extensive approval, which is why “OOP” is utilized to suggest practically any contemporary programming unique from systems programming, assembly programming, practical programming, or database programming. Benefit of object oriented programming language: - – Excellent to specify abstract information type - – A interchangeable structure for program - – Implement reality situation - – The information of executions are concealed from other modules and the modules has the plainly specify user interface - – The adjustment and upkeep of existing code as brand-new object is simple, the brand-new object is little vary from existing one - – Inheritance, encapsulation, polymorphism, abstraction, circumstances, techniques, objects and message death are some essential buildings of object oriented programming language - – All the terms like information kinds of structure and function used in the program is specified by developer Code in object-oriented programming is arranged around objects. You would begin by explaining the objects, such as an individual and vehicle. When you have your objects, you bring them together so the individual can get into the automobile and drive. When you have actually developed objects, you desire them to be able to do something. A method specifies the habits of the objects that are developed from the class. Another method to state this is that a method is an action that an object is able to carry out. Think about the example of an object of the type ‘individual,’ developed utilizing the individual class. The important functions of OOP are: - Focus is on information instead of treatment. - Programs are divided into components. - Information structures are created such that they identify components. - Functions that run on the information of an aspect are looped in the information structure. - Information is concealed and cannot be accessed by external functions. - Components might interact with each other through functions. - New functions and information can be quickly included whenever essential. - Follows bottom-up method in program design. Historically, “OOP” has actually been among the most prominent advancements in computer system programming, acquiring extensive usage in the mid 1980s. Initially declared for its center for handling intricacy in ever-growing software application systems, OOP rapidly established its own set of troubles. The very first action in OOP is to determine all the objects the developer desires to control and how they relate to each other, a workout frequently understood as information modeling. As soon as an object has actually been recognized, it is generalized as a class of objects (think of Plato’s idea of the “perfect” chair that stands for all chairs) which specifies the kind of information it consists of and any reasoning series that can control it. The highlights of object oriented programming language are: – Encapsulation: Encapsulation is the procedure to integrate the information and function to develop a brand-new entity. – Polymorphism: Polymorphism is a Greek word, it is the capability of object oriented programming language which process the objects in a different way according to the information type or class of the objects. – Inheritance: Inheritance is the procedure which assists the object of one class to obtain the homes or functions of another class. The First OOPL Simula, established in the 1960s at the Norwegian Computing Center in Oslo, is thought about to be the very first object-oriented programming language. Regardless of being initially, Smalltalk is thought about to be the only real object-oriented programming environment and the one versus which all others should be compared. It was very first established for instructional usage at Xerox Corporation’s Palo Alto Proving ground in the late 1960s and launched in 1972. Future of OOP The future consists of more standardization of practical programming methods in OOP environments, especially lambda expressions and closures, and more robust meta-programming constructs. Using design patterns instantly through generic or Meta programming strategies is an intriguing location. Object Oriented Programming is not as various from typical procedural programming as is made out by its supporters and is not as hard to comprehend as their proselytizing suggests. It is helpful in making huge such programs however modular programs must have been structured really comparable to an OOP structure anyhow.
A Few Fun Facts About Neptune Neptune, sometimes referred to as the Blue Giant is the eight planet in the Solar System and its location is between Uranus and Pluto. Its diameter is close to 49,500 kilometers in diameter and thus it is almost four times the size of the Earth. The distance between Neptune and the Earth is nearly 4. 4 billion kilometers, and thus, you cannot see it with your naked eyes. Even in the event that you use the binoculars, you can’t see the planet nicely. Below we’ll go over some of the intriguing facts about Neptune. The astronomers from ancient times observed Neptune including Galileo. Nonetheless, Galileo didn’t comprehend he was seeing a planet. In early times, there were no powerful telescopes to help the astronomers and researchers discern planets. Thus, when they discovered Neptune, the astronomers did not note the disk shape of the planet. Mathematical calculations were used by the astronomers and researchers to find this planet. In 1843, an astronomer and mathematician in Britain was key in calculating the location of Neptune. Based on the calculations, the astronomer estimated that Neptune had been one billion kilometers farther away from the Sun compared to Uranus. Another French astronomer did the calculations and got similar results to the British astronomer. Using the calculations developed by the French Astronomer, Johann C. Galle discovered Neptune in September 23, 1846. This discovery was credited to the British and French astronomers since their calculations were key its discovery. Neptune was named after the Roman god of the sea due to Its blue appearance. Its naming follows the remaining planets of the solar system that are named after Roman gods. Iron, nickel and other silicates make up this planet. Methane, ammonia, water, and other chemical substances make up the mantle of Neptune. With temperatures that range from 3000 to 5000K, Neptune’s mantle is very hot. The atmosphere is made up of eighty percent hydrogen, 19% of helium and 1 percent of methane, water, and ammonia. The presence of methane in the atmosphere results in the blue color which characterizes this planet. It absorbs the red light that comes from the sunlight then reflects it in the color blue in space. Thirteen moons that revolve around Neptune till now have been discovered by astronomers and researchers. It is possible that there are more moons which are yet to be discovered. The first spaceship to reach Neptune was called the Voyager 2, and it did so in 1989. It took pictures of the planet and using these pictures, researchers found that the planet has five rings. These rings are; LeVerrier, Galle, Lassel, Adams, and Arago. Folks believe that these rings formed a single planet after one of those Neptune moons got near and divided into countless particles as a result of the gravity in Neptune.
I'm having trouble understanding the current orbit planned for NASA's Space Launch System's Exploration Mission 1. Is it possible to explain how the planned orbit works and what the maximum distance from the Earth, and the Moon will be? The graphic below is from the NASA news item The Ins and Outs of NASA’s First Launch of SLS and Orion. The article says: The outbound trip to the moon will take several days, during which time engineers will evaluate the spacecraft’s systems and, as needed, correct its trajectory. Orion will fly about 62 miles (100 km) above the surface of the moon, and then use the moon’s gravitational force to propel Orion into a new deep retrograde, or opposite, orbit about 40,000 miles (70,000 km) from the moon. The spacecraft will stay in that orbit for approximately six days to collect data and allow mission controllers to assess the performance of the spacecraft. During this period, Orion will travel in a direction around the moon retrograde from the direction the moon travels around Earth. For its return trip to Earth, Orion will do another close flyby that takes the spacecraft within about 60 miles of the moon’s surface, the spacecraft will use another precisely timed engine firing of the European-provided service module in conjunction with the moon’s gravity to accelerate back toward Earth. This maneuver will set the spacecraft on its trajectory back toward Earth... What is a "new deep retrograde" orbit? How will it be new, deep, and differ from the early Apollo-era free-return orbits? Is it what is roughly suggested between 01:37 in the following video — also linked from the same NASA article, where the spacecraft is suddenly far from the moon, and the Earth and Moon appear similar size? below: Apollo-era drawing of Circumlunar free return trajectory, from here. below: EM-1 mission path, from here.
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Modern social work employs three methods of assistance: case work, group work, and community organization. Case work is the method by which individual persons and families are assisted. The person in need of case work may be physically, mentally, or socially handicapped. Among those regarded as socially handicapped are: the unemployed, the homeless, members of broken families, alcoholics, drug addicts, and neglected or problem children. To determine the cause of maladjustment, the social worker must understand individual psychology as well as the sociology of the community. Physicians, psychiatrists, and other specialists may be required to help diagnose the difficulty. Social group work is exemplified by the social settlement, the supervised playground and gymnasium, and the classroom, where handicrafts may be learned. The community may be called upon to provide the buildings and grounds for such activities; often the services of volunteers and of public groups are utilized; in recent years people living in poverty areas have been employed to work in and direct poverty projects in their own communities. Through community organization the welfare work of single agencies as well as of whole communities is directed, cooperation between public and private agencies is secured, and funds are raised and administered. The funds required by private agencies are often pooled in a community chest, from which each agency receives a share. Community welfare councils are organized to map programs of rehabilitation, to eliminate duplication of services, and to discover and meet overlooked needs. Social work emerged as a profession out of the early efforts of churches and philanthropic groups to relieve the effects of poverty, to bring the comforts of religion to the poor, to promote temperance and encourage thrift, to care for children, the sick, and the aged, and to correct the delinquent. Orphanages and homes for the elderly were typical results of these activities. The word charity best describes the early activities, which were aimed at the piecemeal alleviation of particular maladjustments. In such charitable work the principal criterion in determining aid to families was worthiness, while the emphasis in later social work was on restoring individuals to normal life both for their own sake and for the sake of the community. The first attempts to solve the problem of poverty in a modern scientific way was made by P. G. F. Le Play, who in the 1850s made a detailed study of the budgets of hundreds of French workers' families. Forty years later Charles Booth investigated wages and prices, working conditions, housing and health, standards of living, and leisure activities among the poor of London and revealed the extreme poverty of a third of the population. Booth's social survey became a method for determining the extent of social maladjustment, and through surveys in other cities in Europe and the United States a vast number of facts were accumulated, and methods were developed that provided the basis for modern social work. In 1874 the National Conference of Charities and Correction (now called the National Conference on Social Welfare) was organized in the United States. Public relief and private philanthropic effort remained largely matters of local and state concern until after 1930, when the federal government entered the field of social work on a large scale to cope with the effects of the Great Depression. Resources were made available, the number of social workers was greatly increased, and it became necessary to coordinate public and private activities. Social work has been steadily professionalized, and special graduate schools as well as departments in universities have been established to train social workers. By 1999 there were 377 accredited undergraduate schools of social work in the United States. See I. A. Spergel, Community Problem Solving (1969); R. E. Smith and D. Zietz, American Social Welfare Institutions (1970); W. C. Richan and A. R. Mendelsohn, Social Work (1973). Any of various professional activities or methods concerned with providing social services (such as investigatory and treatment services or material aid) to disadvantaged, distressed, or vulnerable persons or groups. The field originated in the charity organizations in Europe and the U.S. in the late 19th century. The training of volunteer workers by these organizations led directly to the founding of the first schools of social work and indirectly to increased government responsibility for the welfare of the disadvantaged. Social service providers may serve the needs of children and families, the poor or homeless, immigrants, veterans, the mentally ill, the handicapped, victims of rape or domestic violence, and persons dependent on alcohol or drugs. Seealso welfare. Learn more about social service with a free trial on Britannica.com. Social work is a discipline involving the application of social theory and research methods to study and improve the lives of people, groups, and societies. It incorporates and uses other social sciences as a means to improve the human condition and positively change society's response to chronic problems. Social work is a profession committed to the pursuit of social justice, to the enhancement of the quality of life, and to the development of the full potential of each individual, group and community in society. It seeks to simultaneously address and resolve social issues at every level of society and economic status, but especially among the poor and sick. Social workers are concerned with social problems, their causes, their solutions and their human impacts. They work with individuals, families, groups, organizations and communities. Social work as a defined pursuit and profession began in the 19th century. This was in response to societal problems that resulted from the Industrial Revolution and an increased interest in applying scientific theory to various aspects of study. Eventually an increasing number of educational institutions began to offer social work programs. The settlement movement's emphasis on advocacy and case work became part of social work practice. During the 20th century, the profession began to rely more on research and evidenced-based practice as it attempted to improve its professionalism. Today social workers are employed in a myriad of pursuits and settings. Professional social workers are generally considered those who hold a professional degree in social work and often also have a license or are professionally registered. Social workers have organized themselves into local, national, and international professional bodies to further the aims of the profession. As there was no effective bureaucracy below city government that was capable of charitable activities, the clergy served this role in the west up through the 18th century. During the Middle Ages, the Christian church had vast influence on European society and charity was considered to be a responsibility and a sign of one’s piety. This charity was in the form of direct relief (for example, giving money, food, or other material goods to alleviate a particular need), as opposed to trying to change the root causes of poverty. The practice and profession of social work has a relatively modern (19th century) and scientific origin. Social work, as a profession or pursuit, originated in the 19th century. The movement began primarily in the United States and England. After the end of feudalism, the poor were seen as a more direct threat to the social order, and so the state formed an organized system to care for them. In England, the Poor Law served this purpose. This system of laws sorted the poor into different categories, such as the able bodied poor, the impotent poor, and the idle poor. This system developed different responses to these different groups. The 19th century ushered in the Industrial Revolution. There was a great leap in technological and scientific achievement, but there was also a great migration to urban areas throughout the Western world. This led to many social problems, which in turn led to an increase in social activism. Also with the dawn of the 19th century came a great "missionary" push from many Protestant denominations. Some of these mission efforts (urban missions), attempted to resolve the problems inherent in large cities like poverty, prostitution, disease, and other afflictions. In the United States workers known as "friendly visitors", stipended by church and other charitable bodies, worked through direct relief, prayer, and evangelism to alleviate these problems. In Europe, chaplains or almoners were appointed to administrate the church's mission to the poor. During this time, rescue societies were initiated to find more appropriate means of self-support for women involved in prostitution. Mental asylums grew to assist in taking care of the mentally ill. A new philosophy of "scientific charity" emerged, which stated charity should be "secular, rational and empirical as opposed to sectarian, sentimental, and dogmatic." In the late 1880s, a new system to provide aid for social ills came in to being, which became known as the settlement movement. The settlement movement focused on the causes of poverty through the "three Rs" - Research, Reform, and Residence. They provided a variety of services including educational, legal, and health services. These programs also advocated changes in social policy. Workers in the settlement movement immersed themselves in the culture of those they were helping. In America, the various approaches to social work led to a fundamental question – is social work a profession? This debate can be traced back to the early 20th century debate between Mary Richmond's Charity Organization Society (COS) and Jane Addams's Settlement House Movement. The essence of this debate was whether the problem should be approached from COS' traditional, scientific method focused on efficiency and prevention or the Settlement House Movement's immersion into the problem, blurring the lines of practitioner and client. Even as many schools of social work opened and formalized processes for social work began to be developed, the question lingered. In 1915, at the National Conference of Charities and Corrections, Dr. Abraham Flexner spoke on the topic "Is Social Work a Profession?" He contended that it was not because it lacked specialized knowledge and specific application of theoretical and intellectual knowledge to solve human and social problems. This led to the professionalization of social work, concentrating on case work and the scientific method. The International Federation of Social Workers states, of social work today, "social work bases its methodology on a systematic body of evidence-based knowledge derived from research and practice evaluation, including local and indigenous knowledge specific to its context. It recognizes the complexity of interactions between human beings and their environment, and the capacity of people both to be affected by and to alter the multiple influences upon them including bio-psychosocial factors. The social work profession draws on theories of human development and behaviour and social systems to analyse complex situations and to facilitate individual, organizational, social and cultural changes." The current state of social work professional development is characterized by two realities. There is a great deal of traditional social and psychological research (both qualitative and quantitative) being carried out primarily by university-based researchers and by researchers based in institutes, foundations, or social service agencies. Meanwhile, many social work practitioners continue to look to their own experience for knowledge. This is a continuation of the debate that has persisted since the outset of the profession in the first decade of the twentieth century. One reason for the gap between information obtained through practice, opposed to through research, is that practitioners deal with situations that are unique and idiosyncratic, while research concentrates on similarities. The combining of these two types of knowledge is often imperfect. A hopeful development for bridging this gap is the compilation, in many practice fields, of collections of "best practices" which attempt to distill research findings and the experience of respected practitioners into effective practice techniques. Although social work has roots in the informatics revolution, an important contemporary development in the profession is overcoming suspicion of technology and taking advantage of the potential of information technology to empower clients. Professional social workers are generally considered those who hold a professional degree in Social Work. Often these practitioners must also obtain a license or be professionally registered. In many areas of the Western world, social workers start with a Bachelor of Social Work (BA, BSc or BSW) degree. Some countries, such as the United States, also offer post-graduate degrees like the master's degree (MA, MSc or MSW) or the doctoral degree (Ph.D or DSW). In the United Kingdom, often referred to as social services assistants or care workers, are persons who are not professionally registered and often do not hold any formal social work qualification. In England, to use the term 'social worker', one must register with the General Social Care Council (GSCC). This followed the Care Standards Act 2000 which has protected the title since April 2005 in England. Within the mental health sector in the UK, an additional qualification can be gained: an "Approved Social Worker". This enables the practitioner to assess and make an application to hospital for admission under the Mental Health Act 1983. In a number of countries and jurisdictions, registration or licensure of people working as social workers is required and there are mandated qualifications. In other places, a professional association sets academic and experiential requirements for admission to membership. The success of these professional bodies' efforts are demonstrated in the fact that these same requirements are recognized by employers as necessary for employment. On a national level there are organizations regulating the profession, as well. Some of these are the British Association of Social Workers (United Kingdom), the Australian Association of Social Workers (Australia), and the Professional Social Workers' Association (India). Professional social workers have a strong tradition of working for social justice and of refusing to recreate unequal social structures. The main tasks of professional social workers can include a variety of services such as case management (linking clients with agencies and programs that will meet their psychosocial needs), medical social work, counseling (psychotherapy), human services management, social welfare policy analysis, community organizing, advocacy, teaching (in schools of social work), and social science research. Professional social workers work in a variety of settings, including: non-profit or public social service agencies, grassroots advocacy organizations, hospitals, hospices, community health agencies, schools, faith-based organizations, and even the military. Some social workers work as psychotherapists, counselors, or mental health practitioners, often working in collaboration with psychiatrists, psychologists, or other medical professionals. Social workers may also work independently as private practice psychotherapists in the United States and are able to bill most third party payers such as insurance companies. Additionally, some social workers focus their efforts on social policy or conduct academic research into the practice or ethics of social work. The emphasis has varied among these task areas by historical era and country. Some of these areas have been the subject of controversy as to whether they are properly part of social work's mission. A variety of settings employ social workers, including governmental departments (especially in the areas of child and family welfare, mental health, correctional services, and education departments), hospitals, non-government welfare agencies and private practice - working independently as counsellors, family therapists or researchers. There are a wide variety of activities that can be considered social work and professional social workers are employed in many different types of environments. In general, social workers employed in clinical or direct practice work on a micro level. Social workers who serve in community practice are occupied in the mezzo or macro levels of social work. The following lists detail some of the types of jobs that social workers may do.
Brief SummaryRead full entry BiologyIn the past, the attractive Soemmerring's gazelles used to gather in their hundreds as they undertook seasonal migrations (2). Today, this magnificent sight is rare, as the gazelle is seldom seen in herds composed of more than 15 individuals. These are often herds of females and their young, accompanied by a single adult male on his territory. The territorial male marks his range with dung, and should another male venture onto his land, aggressive confrontations may ensue (2). Such encounters involve scraping their horns on the ground (3), head-flicking, and yanking their opponent's horns sideways in an attempt to destabilise their rival (2). Mating in Soemmerring's gazelle peaks between September and November (2). After a gestation of around 198 days, the female gives birth to a single calf that lies well hidden in grass until it is strong enough to keep up with its mother (3). This usually takes about a month (2), during which time the mother returns to her calf only to nurse it (3). By the age of six months the calves are weaned, and by just 18 months the gazelle is sexually mature and capable of reproducing. Soemmerring's gazelles live for up to 14 years (2). Soemmerring's gazelles feed primarily on grasses (5); their narrow muzzle and mobile lips enable them to carefully select the best quality grass (3). The main predators of Soemmerring's gazelle include cheetahs, lions, leopards, Cape hunting dogs, hyenas and even pythons (3).
Impact of geography on ancient egypt Alexandria: alexandria, major city and urban muḥāfaẓah (governorate) in egypt once among the greatest cities of the mediterranean world and a centre of hellenic scholarship and science, alexandria was the capital of egypt from its founding by alexander the great in 332 bce until its surrender to the arab. Egypt: influence of geography in this chapter, you learned how three environmental factors influenced the early settlement of ancient egypt, kush, and canaanenvironmental factors three important environmental factors are water. How did the geography of ancient egypt influence life in the region today how did geography impact the ancient egyptians the geography impacted the egyptians in many ways it influenced where the egyptians settled, because it was one of very few water sources around them. Scoring key for part i and rating guide for part ii the information booklet for scoring the regents examination in global history and geography and united states history and government and economy of ancient egypt to the manner in which the nile was used to expand egyptian power. How did the geographic features of ancient egypt and mesopotamia impact civilization development geography played a big role, especially in farming due to geography, mesopotamia and egypt had different farming methods, weathers, environment. Assess influence of geography on ancient egypt, ancient india ninth grade history & social science world history i roman, and arabic philosophy, medicine, and science. Religion in the lives of the ancient egyptians ecause the role of religion in euro-american culture differs so greatly from that in ancient egypt geography, agriculture, art, and civil law--virtually every aspect of egyptian culture and civilization--were manifestations of religious. The nile's impact on ancient egypt - the nile river in ancient egypt allowed the great egyptian civilizations to grow and thrive on its banks learn more about the nile in ancient egypt. Geography: essential question: how did the geography of ancient egypt influence life in the region question: how did geography impact the ancient egyptians the nile river went down ancient egypt which supported the egyptians with a great water source, and supplied them with silt for growing cropsthe nile river helped develop a civilization. Egypt, an ancient civilization in africa, developed a great civilization along the nile river without the nile river, the land could not have supported the. Ancient egypt had many natural barriers the mountains to the south helped to separate egypt from the rest of africa there are deserts to the east and west of the nile river. World history and geography: ancient civilizations their movement to and from egypt discuss the influence of julius caesar and augustus in rome's transition from republic to empire 5. Quiz & worksheet - the nile & egyptian civilization quiz reading comprehension - ensure that you draw the most important information from the related lesson on the influence of the nile on ancient egypt agriculture in ancient egypt go to impact of geography on egyptian culture ch 2. Geography the ancient egyptians thought of egypt as being divided into two types of land, the 'black land' and the 'red land' the 'black land' was the fertile land on the banks of the nile. Start studying chapter 4 ancient egypt learn vocabulary, terms, and egypt's geography affected its farming methods by causing the egyptian farmers to come to rely on the nile's yearly floods for water and fertile soil but the geography of ancient egypt did not influence art or. How did geography impact the ancient egyptians how did the geography of ancient egypt help agriculture develop why was the nile river important to the ancient egyptians. The basic element in the lengthy history of egyptian civilization is geography the common script of ancient egypt and the third in greek the power of the pharaohs of the old kingdom waned as priests and nobles gained more independence and influence. Impact of geography on ancient egypt What were the similarities and differences in the geography of ancient egypt and ancient mesopotamia update cancel answer wiki how do the geographical situations of ancient egypt and ancient mesopotamia influence their traits, religions, and cultures. Egyptian influence in popular culture this article needs and these stand in a number of locations far from egypt the cleopatra's needles that stand in in their adventures they meet and interact with several ancient egyptian gods, such as thoth, anubis, isis, horus. The desert and the nile river emerged millions of years ago when the ancient sea that covered most of europe and northern africa (45 million years ago) the northern region of egypt is bounded by two deserts, the mountainous eastern civilization \| geography your country. That we cannot separate the history of egypt from its geography and other natural aspects ancient greeks said that egypt was the gift of the nile the nile river and its influence on settlement the tomb of tutankhamen way of life in ancient egypt the. Dental bridges physicians in ancient egypt proved to be masters of dentistry and had already learned how to craft effective dental bridges according to th. The ancient egyptian economy the economy of pharaonic egypt has been called an ancient command economy, but one should always remember that such modern definitions are not as apt as one would hope for still ancient egypt - time-life books. The geography, the location where an ancient civilization made its home, had an enormous impact on their culture and daily life ancient egypt geography - ancient egypt had many natural barriers. Ancient creation stories told by the numbers by h peter aleff: site traders from the nile delta had sustained many direct and/or indirect contacts with mesopotamia and other regions of the ancient near another item of early mesopotamian influence on egypt seems to be the concept of. Their inventions and technology had an impact on many more information on the civilization of ancient egypt: overview timeline of ancient egypt old kingdom middle kingdom new kingdom late period greek and roman rule monuments and geography geography and the nile river cities of ancient egypt. Far from simply being the owner of the feline face behind the iconic golden funeral casket, boy-pharoah tutankhamun also ushered in a raft of reforms in his decade-long reign many of these revolved. How did the geography and climate affect settlement and land use in the impact of the land on the way the ancient egyptians lived it is also important to point out the role the climate has played in preserving materials and objects from ancient egypt the geography and climate of. Kids learn about ancient egyptian geography and the nile river the nile provided fertile land, transportation, and building materials for egypt. Coordinates the geography of egypt relates to two regions: north africa and southwest asia egypt has coastlines on the mediterranean sea, the river nile and the is isolated from the rest of egypt but has sustained life since ancient times. What is the legacy of the ancient egyptians the ancient egyptian culture had a strong impact on other ancient civilisations one of the greatest legacies of ancient egypt was the invention of papyrus, reed paper. How did the physical geography of ancient egypt shape the development of its civilization in ancient egypt, the geography helped the people there live how did china's physical geography influence the development of its ancient civilization. Impact of geography geography for the nile river valley civilization was very important the nile would flood each year starting in july and lasting until november possibly found ancient rome accredited for combining upper and lower egypt.
What are the statistics of malaria? If you mean the number of cases worldwide and the number of deaths, then the statistics are as follows: the World Health Organization estimates that approximately half the world’s population are at risk from malaria infection, and as a result, there are somewhere between 300 and 500 million cases of malaria every year, worldwide. However, this may be an underestimate, since many people don’t seek help when they have malarial symptoms. The same is true of number of deaths per year from malaria – it is currently estimated that between 700,000 and 800,000 people die every year from the disease, but as with the number of cases, there may be unreported deaths as well. Organisations such as Malaria No More seek to eliminate deaths from malaria by the year 2015. If you have more specific questions regarding the statistics of malaria, please feel free to ask!
Size: Architeuthidae can grow up to 60 feet in total length, and weigh between 1000 lbs and a tone. The Genus Architeuthidae are the largest known cephalopods, the largest known mollusks and the largest invertebrates ever known to exist in the ocean. Habitat: A giant squid lives between 200 and 1000 meters in depth, close to the bottom of the sea, around large underground canyons. They must live in deep water because the blood of squids does not carry oxygen very well at higher temperatures. If a squid swims too close to the surface, it will actually suffocate in the warmer water. Warm water will cause a giant squid to rise to the surface and not be able to get back down. Feeding: Giant squid are carnivourous mollusks, which eat deep-sea fish, such as orange ruffie, and hokie. They also eat other types of deep-sea squids, but not other giant squids. They are so large, that they can capture and eat almost anything, even some smaller whales. They capture their prey by using their two long feeding tentacles which are shot out to grip the prey, suckers on the tips of the tentacles grab hold of the prey and bring it back to the arms. The arms then further subdue the prey, pulling it to the strong, sharp beaks which form a kind of razor. The beaks the beaks are so sharp and strong that they can rip-apart just about anything the squid might capture. Before the squids bite-sized pieces of food are digested, further shredding is needed. The flie-like radula then shredds the food further and before the tounge pushes it down the esophagus towards the stomach and other digestive organs. Respiration: Giant squid have two, very large gills resting inside their large mantle cavity. The squid are able...
You are hereHome › Now showing results 1-3 of 3 Intended for use prior to viewing the Science on a Sphere film "Water Falls," this lesson introduces students to Earth's water cycle and the importance of freshwater resources. In this lesson, students will think about their experiences with hurricanes and severe storms, and then learn the basics of what causes hurricanes to form. Students will learn how hurricane prediction has progressed, and how satellite technology is... (View More) used to see inside storms to get improved data for enhancing computer-based mathematical models. To share what they’ve learned, students will create a news report (script or comic strip) to tell others about hurricanes and hurricane prediction. This lesson uses the 5E instructional model. TRMM is Tropical Rainfall Measuring Mission. (View Less)
The Three Little Javelinas Author: Susan Lowell, Illustrator: Jim Harris Northland Publishing 1992 Grade Level Focus: 1st grade This is a story about the three little javelinas that live in the desert. It is a story similar to the three little pigs we are all familiar with, however it is all about the desert and the habitat of the desert. It tells how these pigs use the different elements of the desert to make a safe home and survive the coyote. It clearly portrays what makes up a desert and how one has to survive in a desert. Since geography is one of the main themes of social studies curriculum, this book will work quite well. It will help the student learn about what lives in the desert and how people can survive in the desert. It also explains the climate and ways the people and animals of the desert adapt to this heat. Relationship to Social Studies State Core: conclusions to stories or situations. Recall facts from stories or reports. Demonstrate how geographic features, climatic conditions, and natural resource influence how they live. Identify on maps the deserts of the United States. Compare the desert region to the other regions of the Western Hemisphere. Identify a logical sequence for tasks. Title of Lesson: Prediction Students will be able to predict a conclusion to the story The Three Students will identify reasons for their predictions. Materials Needed: Paper, pencil, creative minds 1. We will read the story The Three Little Javelinas. Tell the students to listen and look for characteristics and geological features of the desert while you are reading the story. a. Read the story up until the part where the two javelinas have been chased from their house made of saguaro sticks. b. Have the students make predictions about what they think will happen to the two javelinas using characteristics of the desert to explain the reasons for their prediction. We will write these predictions on the board for everyone to see. 2. Have the students take out a piece of paper and write down their prediction making sure to include the reasons why they have chosen the certain event to happen to the two javelinas. They must include desert characteristics with their predictions. 3. Finish reading the story. (The Three Little Javelinas) a. Check the predictions with the ones on the board to see how accurate the predictions are. b. Discuss the process they used to come to the conclusions they did about the outcome of the story. c. Discuss all the characteristics and features they found throughout the story and compare these to that of our own region. Are the two regions similar? Does the desert have plants and animals we donít see here in our region? I will evaluate each students prediction to see if they understand how to predict a simple conclusion to a story. If they have used the events of the story to come to a good conclusion that makes sense, and they can given reasons for their prediction, including characteristics of the desert region, (include at least three characteristics) I will know they understand the process of predicting. The prediction does not have to be correct for them to understand how to predict. Title of Lesson: Desert Regions Students will be able to create a house that displays how different people live in some parts of the desert. Students will be able to identify characteristics of the desert region and compare them to other regions. Materials Needed: Mud, straw, glue, poster board, markers, brick shaped box (rectangle shaped) 1. Read the story The Three Little Javelinas, and have the students listen for specific characteristics of the desert region. 2. Guided Discussion. Explain to the students how people that live in different regions have different ways of life. Have the students tell you what differences they noticed in the story about the desert habitat. Discuss the climate, features, and resources of the desert. Then share with the students an example of how the desert is different from other regions they are familiar with. (e.g., There are mountains where we live and in other areas, it is entirely flat. In some regions it snows quite a bit, in others it rains almost everyday of the year.) Make sure they understand how regions are different and have them give some of their own examples of differences. 3. When discussing the differences of the regions we are familiar with, make sure you discuss what the houses are made out of that are in a desert at the time the story was written. Identify the materials they used to build the houses in the desert. Are the materials the same or different as the ones we use to build our houses? 4. Hands-On. Have the students create their own adobe house depicting the characteristics the have learned from the story. a. In groups of four the students will create an adobe b. Give each group some mud and some straw and a big bucket to mix them together in. They will have to mix it together until the straw is completely mixed into the mud. c. They will then place the mud in the brick shaped box to form the bricks d. After they have formed the bricks they will be set out by the window to dry for a couple days. e. Once the bricks have dried, they will build a small house on their poster board with the bricks they have created. f. They will be able to add any other features or characteristics of the desert that they learned to their project with markers. During the guided discussion I will be able to tell if they have learned new characteristics of the desert if they are able to answer my questions and keep up with the discussion sharing their ideas about desert regions compared to other familiar regions. I will also examine their project and if they have created and adobe house and added different feature of the desert, I will see that they understand what makes up the desert regions. Title of Lesson: Map Creating Students will recall facts from the story. Students will create a story map by identifying a logical sequence for the events of the story. Materials: White paper, colored pencils 1. Create a story map on the board with the class. a. Ask the students to identify all the different places they have been in the school that day. b. Write the different places on the board. c. Have the students together as a class identify which events happened first, second, third, and so on until every event is in order. d. After they are in sequence, draw the first place on the board. Then have the students help in placing each location, showing how you would use the school as a guide to where you should draw each place on the map. e. Explain to the students that this is the process you use in creating a story map. ( putting items in a logical sequence, and then creating a image of each place on your map.) 2. Review the story you have read to them earlier, The Three Little Javelinas. Have the students identify the events that took place throughout the story that they can remember. Write these events/places on the board. a. Where the three javelinas were at the beginning. b. What happened to each javelina individually throughout the story. c. What happened to the three javelinas at the end of the story. d. Where they were throughout the story. 3. Tell the students to take the events we have listed on the board and have them write them down on piece of paper in the correct sequential order. 4. Have the students create a map showing each event and the distances that the javelinas traveled around the given space of the paper. Make sure they identify any objects they include in their map so others will be able to read the story map and understand the sequence of events. 5. Students will be able to share their story maps with the class if they would like to. It is only an option for those that are willing and want to share. The students will demonstrate that they understand how to identify a logical sequence of events if they have displayed each event in the proper order on their map. Their story map will also show that they understand how these events took direction and traveled across their paper if they have illustrated each event correctly and placed it on the paper in the right place and order. Title of Lesson: Desert Animals Objectives: Students will chose a desert animal. They will research their animal and give an oral report presenting the information they have gathered about their animal. Materials: A variety of books about the desert, poster board, markers, white and lined paper. 1. Discussion: Discuss with the students different animals found in the desert and adaptations they have made to survive. Can any animal survive in the desert? What are ways the animals change to live in the desert? Can a desert animal be brought to a different environment and survive? (adapt) 2. There will be variety of different desert books that have animals that live in the desert. The students will be allowed about fifteen minutes to look through the books to find an animal that interests them. 3. Values Whip. Once they have been given plenty of time to look through the books, we will have a quick values whip session. I will have the students think of one animal that they found that lives in the desert. We will go around the classroom and have the students name one animal. We will go quickly student by student, allowing anyone to pass if they canít think of an animal. 4. When the entire class has had the opportunity to name a desert animal, I would have each student make a decision on what animal they want to research for their oral report.The students at that time would tell me the animal they have chosen. 5. We would go over the research skills used in finding information about your topic. a. How to use a dictionary. b. What key points you should find out about your animal. (worksheet) c. Deciding what details the class would want to know. 6. Each report needs to include how their animal survives in the desert. (what adaptations are made for survival?) They also need to include their ideas about bringing their animal to a different region. (Can they adapt? Will they survive?) 7. After they have researched the information they can chose a way to present the information to the class. b. Reading your written report c. Sharing facts with a picture of your animal for them to see. 8. The reports will then be shared with your class so they can all learn about a different desert animal. Observation of the studentsí oral reports will demonstrate their new gained knowledge of a desert animal. I will also read the worksheet I gave them to fill out about key points of their animal and if they have answered those questions correctly I will know that they have researched their animal and found out important ideas to share to the class. Included in their report must be the ways of adapting to desert climate and how the animals would survive in a new climate or region. The three javelinas are out finding their fortune and come to a split in the road. Each pig chooses a different route. The first javelina builds a house out of tumbleweed. The coyote comes to the house and huffs and puffs and blows it down. The second javelina builds a house out of saguaro ribs (sticks). The first javelina comes to join the second javelina in his house of sticks. The coyote comes to the second house and blows it down, the javelinas run to find the third javelina. The coyote follows them. The third javelina built her house out of adobe bricks. The other two javelinas joined the third in the house made of adobe bricks. The coyote could not blow the house down, so he climbed the roof to enter in by the stove pipe. The coyote was burnt by the stove pipe and ran away never to bother the javelinas again. 1. What is your animal? 2. What does your animal 3. How big is your 4. How does your animal deal with heat? ________________ 5. Does your animal have babies? _________ 6. How does your animal treat its young? _________________ 7. Does your animal sleep during the night, or in the day? ____________ 8. What is the most interesting thing about your animal? Draw a picture of your animal: 1. Inquiry - Separate the students into groups of four. Give each group a set of pictures that clearly show characteristics that make up a desert region. Have the students identify these characteristics and try to figure out what this region is. As a whole class, discuss the characteristics each one found and together decide on a region these pictures could represent. Retrieval Charts - Give the students a chart to fill out while they are listening to the story. On the top of the chart have these headings: plants, animals, climate, features, attire. Have the students list anything they find in the story that may fit under these different categories. Go over the charts as a class to see the different characteristics of the desert. 3. Decision Tree ñ Have the students create a decision tree that compares the good and bad consequences of building a house in the desert and what materials they javelinas use. Have the tree they create show all three houses and the materials used to make the houses. The students will write down in the tree good and bad consequences of how the javelinas created each house.
Instruments Used for Non-musical Purposes Pukaea: A long wooden war trumpet very like the solemn-sounding ceremonial trumpets of Tibet. It has a length of from 4 to 6 ft, a diameter of 1¼ in. at the blowing end and widens out to about 8 in. at the bell end. It is made in the same way as the putorino, hollowed out in sections and joined together again. The flare at the lower end is made by joining together a number of triangular wedges of wood which are gummed and bound to the end of the pipe. A few inches above the bell end, a tonsil or vibrating reed has been inserted in the pipe, perhaps in imitation of the human throat, but the purpose of this device remains in doubt. Compared with the simplicity of the koauau, nguru, and putorino, the pukaea, with its vibrating tonsil and bell-shaped end seems to be out of character. It gives forth a loud booming sound like the siren of a large ocean liner, and was used to sound an alarm in time of danger or to terrify an enemy by shouting curses through it. Putara or Pumoana: A shell trumpet found in many places in the world and known to the ancient Greeks and Romans as a Triton's trumpet. The Maori version was made by cutting off the spiral end of a conch shell and fitting on a wooden mouthpiece. When blown by a lusty lunged Maori, it produced a loud, clear note suitable for signalling. It was also used for ceremonial purposes such as to announce the birth of a male child of rank, or to gather people together for a special occasion. Pahu: The only percussion instrument invented by the Maori. It was made from a slab of totara about 30 ft long, suspended from a ridge pole erected on an elevated part of the pa and beaten with a heavy club, like a gong. The sounds could be heard miles away and reverberated round the hills like a loud peal of thunder. - A Pacific Bibliography, Taylor, C. R. H. (1951) - Studies in Maori Rites and Myths, Johansen, J. P. (1958).
For every person petitioning for conversion to solar power for heating and electricity, there are dozens of us scratching our heads, asking all the relevant questions about this supposedly clean, efficient, and generally usable energy source. You might find yourself wondering how solar power works, how difficult it is to put into effect, and basically whether it is in fact as good a source of electricity as some claim. There are lots of resources on the web where you can learn about solar power, but here are some of the basics to help you get started. As it turns out, the process for converting sunlight into electricity is surprisingly simple. The sun provides huge amounts of energy, much of which reaches our planet in the form of radiation known as visible light, a part of the electromagnetic spectrum you know and use every day. When visible light hits most surfaces, usually two things happen: Because light is a kind of energy, it can be absorbed and converted to heat when it strikes many substances. However, if it hits the right substance, visible light will be turned into electrical current. You’ve probably heard of and even seen solar panels before, but you may not have known how they do what they do. This part of the process is a little more tricky. Solar cells are composed primarily of silicon, which acts as a semiconductor if it is ‘bundled’ or arranged in the right way. Semiconductors like this create an electromagnetic field which can help propel electrons if properly instigated by something like the energy from sunlight. If you’ve ever experimented with opposing ends of magnets, you have created magnetic fields and you can feel how the magnetic bodies attempt to balance by pulling towards each other at opposite polarities. Silicon semiconductors function similarly. Pure silicon is inactive, but it can be charged by introducing a new element. If phosphorous is added, the atoms arrange with an extra electron, thus creating a negative charge, and electricity that wants to jump to a positive source if excited. If boron is added, the silicon structure will form without an electron, making a net negative charge. When you put n-type (negative) silicon in contact with the right amount of p-type (positive) silicon, you have essentially created a solar cell. If you link enough of these solar cells together in a place where they can absorb solar energy, you will have made a solar panel which will create enough energy to power a house or even a satellite orbiting around the earth. Obviously, you can’t just put panels on your roof and expect them to power your home; you need to hook up your home’s electrical wiring with the solar panels to use the electrical output. Though it is possible to install solar panels yourself, it is probably best to hire someone with electrician training. If you are interested in doing home solar panel installation yourself, find out what it would take to earn your electrician degree and become licensed yourself. According to many testimonies, the conversion to solar heating pays for itself quickly, is an efficient and long-lasting way of powering a home, and produces no carbon dioxide or other environmental toxins. And, yes, if you have a battery grid which can hold the charge absorbed during the day, your solar panels will still work at night. So if you were wondering how solar power works and if it’s right for you, hopefully we provided enough information to help you out! Copyright © 2002-2013. All rights reserved
Have you ever ridden in a car driving across a suspension bridge? Suspension bridges, with their tall towers, long spans and gracefully curving cables, are beautiful examples of the work of civil engineers. How do the cables and towers withstand the load of the bridge—including you and the car you're in? Can a suspension bridge carry a greater load than a simple beam bridge that doesn't use cables? You can try to answer these questions in this suspenseful science activity! A beam bridge is the simplest type of bridge. It is typically supported by a raised part on either end. For example, a beam bridge could be as simple as a wood plank put down to cross a stream. Suspension bridges are a bit more complicated. They comprise a deck (the long straight part that includes the road), cables and towers. The cables stretch between the towers and help support the weight of the deck and its load. In this type of bridge the cables are under tension and the towers undergo compression. Suspension bridges might seem complicated, but for spanning long distances they can also be the most economical—they require less material per foot than would a simpler beam bridge. Because suspension bridges are relatively flexible, however, high winds and other forces can be a serious problem. The dramatic collapse in 1940 of the Tacoma Narrows Bridge in Washington State is an infamous example of this. (You can watch a video of the disaster here.) In this activity you'll build and test two types of bridges: a basic suspension bridge and a beam bridge. Which type of bridge do you think can support a heavier load? • Seven disposable plastic drinking straws • Masking tape or painter's tape • Four paper clips (At least two should be large ones.) • Paper cup, at least eight ounces • Many coins, all the same type (For example, you should have at least 150 quarters or at least 325 pennies.) • Two chairs, tables or desks that can be arranged to build a bridge between, and on which tape can be used • If your straws are the bendable type, cut the flexible part off (so that you are left with a long, straight, nonbendable straw piece). Cut a total of six straws this way. Make sure they are all the same length; trim some if necessary. (If you are using nonflexible straws, use the whole straws for the long pieces.) • Cut the seventh straw to make two short pieces of straw, each about one inch long. Make sure they are both the same length. (If it has a bendable part, cut your short pieces from the other end.) • Tape two of the long straws to each end of one of the short pieces of straw. • Then, tape the long straws together at their other ends. You should have an elongated triangle shape. This is one of the towers for your suspension bridge. • Repeat this process with two new long straws and the other short straw piece to build the second tower. • Tape one tower to the edge of a desk, table or chair. The short straw piece should be at the bottom of the tower (and the pointy end without a short piece should be at the top). Tape the second tower to a second piece of furniture at the same height. Position the towers far enough apart so that you could fit the remaining straws between them. • Place a long straw between the towers so that its ends rest on the short pieces. This straw is the deck. You now have a simple beam bridge. Can you see how this is a beam bridge? How do you think it would be different from a suspension bridge? • Make a load tester for your bridge by unbending a large paperclip into a V-shape. Poke the ends of the paperclip into opposite sides of a paper cup, just below the thick rim at the top. • Use a second large paperclip to hang the load tester over the bridge deck. Do this by attaching the two large paperclips together, and then sliding the new one around the bridge deck straw. Slide the cup to the middle of the straw deck. • Add coins (all of the same type) one at a time into the load tester. Keep a count of how many coins you are adding. How many coins does the cup hold before the bridge fails? How does the bridge fail? • Begin turning your structure into a suspension bridge. Pick a new long straw to serve as the deck. • Cut a piece of thread about three feet long. Tie the center of the piece of thread (which will act as your bridge cable) around the middle of the new bridge deck straw. Place the straw between the towers as before. • Pass each end of the thread over a tower and down the other side. To anchor the suspension bridge, tie each end of the cable around a paperclip. Slide the paperclips away from the towers until the cable pulls tight. Then tape the paperclips firmly to the furniture. • Attach the empty load tester cup as you did before. Again add coins (all of the same type as before) to the cup, one at a time. How many coins does the cup hold before the bridge fails this time? How does the bridge fail? • Overall, which bridge design is stronger? Is it a little stronger or a lot stronger? Why do you think you got the results that you did? • Extra: Test each bridge design a few more times, using a new bridge deck straw each time. Are your results always the same? • Extra: Try eliminating the portion of the cable from the towers to the anchorage (leaving only the portion of the cable from the bridge deck to the towers). What happens when you test your bridge with a load tester now? Why? • Extra: Try this activity a few more times and focus on what part (or parts) of the bridge fails first. Was the failure due to weakness of materials used or weakness at a joint? Can you think of ways to redesign your bridge to make the part (or parts) that failed stronger? Observations and results Did the suspension bridge hold a greater number of coins compared with the beam bridge? In this activity you should have seen that the suspension bridge was able to hold more coins than the beam bridge by around 150 percent, such as about 310 pennies (or 140 quarters) compared with about 200 pennies (or 90 quarters). When the beam bridge failed, this was likely because the deck straw bent downward as more coins were added until it bent so much that it slipped down between the two towers. As coins were added to the suspension bridge, the cable (that is, the thread) was under tension and reinforced the bridge deck straw, pulling it upward (while compressing the towers) and allowing the bridge to hold more coins. When the suspension bridge eventually failed, the bridge deck straw likely similarly bent into a V-shape, but because it was attached by the thread the straw couldn't fall and instead the cup may have slipped off of the straw. More to explore Super Bridge: Build a Bridge, from NOVA Online, WGBH Mysteries at the Museum: Tacoma Narrows Bridge, from the Travel Channel Fun, Science Activities for You and Your Family, from Science Buddies Keeping You in Suspens(ion), from Science Buddies This activity brought to you in partnership with Science Buddies
- What does music from other cultures and countries sound like? - How is music from other cultures and countries different from my experience? - Music from other cultures can utilize different instruments. - Music from other cultures can utilize musical elements uniquely. - Music from other cultures often accompanies cultural holidays or events. - Music from other cultures often includes other fine arts, such as dance. - (Priority) Performing #6: Convey meaning through the presentation of artistic work - (Priority) Responding #7: Perceive and analyze artistic work - (Supporting) Connecting #11 : Relate artistic ideas and works with societal, cultural, and historical context to deepen understanding - (Priority) MU:Pr6.1.5a Apply teacher provided and established criteria and feedback to evaluate the accuracy and expressiveness of ensemble and personal performances. - (Priority) MU:Re7.1.5b Demonstrate and describe, citing evidence, how responses to music are informed by the structure, the use of the elements of music, and context (for example, social, cultural, historical). - (Supporting) MU:Cn11.1.5a Demonstrate understanding of relationships between music and the other arts, other disciplines, varied contexts, and daily life as developmentally appropriate. What to Teach - I can/SWBAT identify world music genres by citing defining characteristics. - I can/SWBAT maintain my rhythm pattern with the beat while the other members of my ensemble are playing.
Every baby in the womb eats what its mother does, or more accurately derives its essential nutrients from her. Thus, even mild maternal malnutrition can impair fetal development. The consequences are serious, profound, last a lifetime and yet happen silently. In India a large number of women are undernourished when they conceive; the situation gets worse as the pregnancy progresses. Studies show that malnourished women are more likely bear malnourished children who either die early or grow into sickly adolescents and adults. What deprives women of the nutrition they need? Some reasons are societal, others economic and still others stem from entrenched gender biases. Here again while the poor are the most vulnerable, surprisingly even other segments of society do not always adhere to good nutritional practices although affordability is not an issue. There is increasing evidence to show that more progress in reducing child morbidity and mortality can be made if we improve the nutritional status of mothers before and during pregnancy. We need to use the pregnancy period as a window of opportunity to deliver high-impact interventions in order to ensure that the number of malnourished pregnant mothers declines rapidly enabling them to give their babies a healthy start in life. "Infants born to mothers with anaemia are at far greater risk of low birth weight, premature birth, and early death." Infants born to mothers with anaemia are at far greater risk of low birth weight, premature birth, and early death; those that survive are at risk of impaired physical and cognitive development. Nearly half of India's pregnant women are anemic and this percentage is higher in some states because of factors such as sickle cell disease, worm infestation and lower access to iron rich foods. Screening of pregnant women for risk factors that lead to malnutrition becomes critical to tackle the situation. High-risk factors are maternal weight below 40kg, weight gain of < 6 kg during the pregnancy, hemoglobin < 9gms, maternal age < 18 or above 35 years and earlier history of still birth and abortions. Such mothers need supplementation with additional proteins and calories, with continuous monitoring throughout their pregnancy. Correction of anemia with proper iron and folic acid tablets can help reduce incidence of complications related to anemia. In addition, providing women with access to nutrition education on the importance of a balanced diet (and what that is), how to get the nutrition they need through traditional home food and locally available ingredients can go a long way in improving their nutritional status. Preventing malnutrition of women in the childbearing age also requires social intervention and political commitment. We need to share nutritional information with all pregnant mothers and their families. It is vital that nutrition interventions are integrated into antenatal care programmes; public health systems need to prevent and treat nutritional deficiencies, encourage households to meet the dietary needs of women throughout their lives and ensure their access to high-quality health services, clean water and adequate sanitation. UNICEF India supports the government in strengthening capacities of health managers and supervisors at district and block-level to plan, implement, monitor and supervise effective maternal health care services with a focus on high-risk pregnant women and those in hard-to-reach communities. We believe that these cross-sector efforts to improve maternal nutrition and health will lay the foundation for healthier pregnancy outcomes, paving the way for healthier children and bringing down the high incidence of malnutrition in children. Read Part 1 of Breaking The Cycle Of Malnutrition here.
Method of Spanish as a Foreign Language addressed to 11 and 12 year-old students, that corresponds to the A1 to B2 levels of the Common European Framework of the Languages. Each level is divided in 9 units. Each of them works on language samples and activities developed following the communicative scope adapted to the necessities and learning styles of the students. Each unit includes 8 pages: 2 dedicated to vocabulary where the lexicon is presented; 2 to grammar that introduce one or two grammatical structures in sentences or short texts; 2 to communication with contextualized conversational models; 1 to skills with varied activities; 1 to reflection exercise; and 1 to self assessment. There is a PROJECT every three units, essential to do a review and to integrate what has been learnt in the previous lessons. It goes together with a list of descriptors extracted from the Portfolio in order to help teachers and students to follow and self evaluate the learning process. At the end of the book there is a grammatical summary and a section with conjugated verbs. The Student's book comes with a CD that includes the activities from the student's book and the workbook. For each of the four levels there are four components: Student Book (including audio CD), Exercises book (No CD), Tutor/resources book, digital whiteboard disc (pizarra digital). 1 266 руб. ориентировочная дата отгрузки: 27.06.2017 (Вт.)
19 January 2023 UN INTENSIFIES EFFORTS TO CURB CHOLERA OUTBREAK Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium Vibrio cholerae. It takes between 12 hours and 5 days for a person to show symptoms after ingesting contaminated food or water. Cholera affects both children and adults and can kill within hours if untreated. Cholera transmission is closely linked to inadequate access to clean water and sanitation facilities. Typical at-risk areas include peri-urban slums, and camps for internally displaced persons or refugees, where minimum requirements of clean water and sanitation are not met. Cholera is rampant in Malawi with seasonal outbreaks reported during the wet season. Since 1998, cholera cases have been reported in Malawi with significant morbidity and mortality in affected populations, especially in the southern region, which is low-lying, flat, and prone to flooding during the rainy season. The current outbreak, which started in March 2022 has affected all 29 districts of Malawi and represents the largest outbreak reported in the country in the past ten years Since the onset of the outbreak last March, over 23,000 cholera cases have been recorded with nearly 800 preventable deaths. Last month alone, authorities reported over 7,000 new cases and nearly 300 deaths. As all 29 districts of the country have been affected, the government declared a public health emergency on December 5 2022. The government-led presidential task force on cholera decided to delay the opening of schools in the country’s two biggest cities, which affected nearly 1 million children. But learners returned to class on 17 January. In response to the situation, the UN team in Malawi, led by Resident Coordinator Rebecca Adda-Dontoh, is intensifying its joint support for national authorities as the country is facing the worst cholera outbreak in two decades. To avoid students falling further behind after years of COVID interruptions, UN Children’s Fund (UNICEF) is ensuring Water, Sanitation and Hygiene (WASH) facilities are in place in schools, while World Food Programme (WFP) has distributed hygiene items, reaching over 600,000 learners. UNICEF and World Health Organization (WHO) are furthermore working with health authorities to train health care workers on cholera case management. They also provided nearly 60 urgently needed staff, 438,000 Oral Rehydration Solution (ORS) doses and 1,324,400 water purification tablets. Additionally, both UN entities supported the national Oral Cholera Vaccination campaign, which delivered 2.9 million doses to at risk populations. UNICEF has just handed over $300,000 in further life-saving supplies, such as Acute Watery Diarrheal kits, tents and antibiotics, which will be distributed to cholera treatment centres immediately. Despite the continuing efforts in the national cholera outbreak response, and the need to intensify efforts, significant gaps exist. This includes the urgent need to strengthen surveillance system for early detection and management; increase quality case management at cholera treatment units; provide critical supplies required to manage cholera cases and for water treatment, personal hygiene and water storage at the household level; increase timely community engagement and dissemination of communications around cholera prevention, and positive hygiene practices. The UN is therefore, appealing to partners and donors for additional funds and support to address these challenges and enable them to better support the Government in its efforts to contain the outbreak.
We’ve all had trouble squeezing our luggage down to the allowed weight for a flight. But for a trip to Mars that problem is magnified. The NASA rule-of-thumb is that for every kilogram to be launched into space, you need 99 kilograms of fuel and rocket to get it there. Forget the spare toothbrush. But maybe a solution to all the stuff we’ll need on Mars lies within the bodies of the astronauts. A manned spacecraft produces about a kilogram of carbon dioxide a day from the exhaled breath of each astronaut. Add to that the urine and wash-water, and a crew of six could arrive on Mars carrying more than six tonnes of potentially valuable organic material. This, together with the basic raw materials available on Mars, could provide the building blocks for four of life’s necessities: fuel, food, plastics and medicines. All it takes is a little help from genetically engineered microbes. At least that’s what Amor Menezes at the University of California, Berkeley, in collaboration with scientists from NASA, proposes in a paper published in the Journal of the Royal Society Interface in November. The paper estimates that employing microbes on a two-and-a-half year trip to Mars could deliver huge savings in the mass of the outbound rocket’s payload. The trip to Mars would take seven months. And the fuel for the return journey would take up two thirds of the mission cargo. To reduce the load, the Berkeley/NASA team considered generating methane fuel from Martian resources for the return leg. Generating it requires CO2, which is 95% of the Martian atmosphere, and hydrogen, which could be sourced from the planet's frozen water using electricity to split it into hydrogen and oxygen. The chemical reaction requires heavy duty equipment to reach high temperatures and pressures, which rather defeats the purpose. But lightweight microbes such as Methanobacterium thermoautotrophicum are designed for the task. On Earth, they live on hydrogen and CO2, spewing out methane as a by-product. In a vat filled with CO2 and hydrogen, the team calculate the microbes could make all the fuel needed for the return journey in 205 days, less than half the planned stay on Mars. The incubator needed for the microbes would weigh less than half that needed for the chemical synthesis of methane. On the International Space Station astronauts subsist on a combination of freeze-dried meals that must be rehydrated before eating, and packets of “wet food” that are quick to prepare and also more appetising. Feeding Martian astronauts for 30 months would require more than 10 tonnes of wet food. The biotech solution proposed by the team is for the astronauts to eat spirulina – a green, flaky foodstuff made from photosynthetic algae that grows naturally on the surface of saltwater lakes in Central America and Africa. It’s been eaten by humans since the time of the Aztecs, and recently surged in popularity as a “superfood”. Spirulina production would cut by 38% the mass of wet food that would have to be shipped to Mars. It is also more nutritious than wet food so astronauts need less of it. The Berkeley and NASA researchers calculate that more than five kilos of spirulina a day – enough for the whole crew – could be grown in bioreactors the size of two kids’ paddling pools. This would save about a third of the mass-cost of sending wet-food to Mars. And, as Menezes adds, by genetically manipulating the algae, “you can change the flavours and textures of the spirulina, so you don’t feel like you’re eating the same thing every time”. NASA is researching 3D printing in space. A printer could be used to make interlocking blocks for building a Martian habitat. NASA’s idea is to print blocks by bonding a mixture of minerals in the Martian soil with salts brought from home. But printing a six-person habitat from this material would add up to at least 24 tonnes to the mission’s weight, much of that due to the weight of the salts. Instead, Menezes proposes using bacteria to produce a light-weight biopolymer, polyhydroxybutyrate, which could be 3D printed to form plastic construction blocks. All the necessary ingredients, including CO2, hydrogen and oxygen, should be available on the spacecraft. Even the ammonia the bacteria need could be taken from the astronauts’ urine. The crew could start printing pieces for their new home before they arrive. According to the team’s calculations, this approach could save 85% of the mass-cost of the mineral-based 3D printing approach. Drugs tend to expire faster in space due to higher radiation levels. But what if there’s a medical emergency after the use-by-date? The team identified a bacterium, Synechocystis, which, with a bit of genetic modification, could be used to create paracetamol from available resources. The bacteria could be frozen in a small lead container until needed. After thawing out the bacteria, paracetamol stocks could be replenished in days. Christophe Lasseur, who has researched long-term human habitats for the European Space Agency, has no doubt microbes can be used to create products in space, but adds that we don’t know how the radiation levels will affect the bacteria’s survival. “Mars contamination is another issue,” he adds. The search for life would be a prime goal of any mission to Mars. Deliberately bringing microbes from Earth could have the unwanted effect of tainting the planet. “This is why it is extremely important to arrive on Mars with the cleanest vehicle possible,” he says. Previous Martian probes, such as Spirit, Opportunity, and Curiosity, were all thoroughly decontaminated before their launch. Menezes admits that containment will be important, but emphasises his work is the first step in examining microbes as potential shipmates on a trip to Mars. Initial results are promising, he adds. “Already we can compete with non-biological technologies – imagine what would happen if you engineer them to be even better.” Originally published by Cosmos as Packing light for Mars Cathal O'Connell is a science writer based in Melbourne. Read science facts, not fiction... There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
Earth Day is an important reminder of the critical role that each of us can play in protecting our planet. As we celebrate this day, it is important to take a moment to reflect on the impact that we have on the environment and to consider the steps that we can take to reduce our carbon footprint. One of the most effective ways to do this is by promoting plastic recycling. Plastic is a versatile and useful material that is found in many products that we use on a daily basis. However, the disposal of plastic waste has become a significant environmental issue, with millions of tons of plastic waste entering our oceans and landfills each year. This has a devastating impact on the environment, wildlife, and human health. Recycling plastic is one of the most effective ways to reduce the amount of plastic waste that ends up in our landfills and oceans. By recycling plastic, we can conserve resources, reduce pollution, and protect our planet for future generations. Here are some of the reasons why promoting plastic recycling is so important: Plastic is made from non-renewable resources such as crude oil and natural gas. By recycling plastic, we can conserve these resources and reduce our dependence on fossil fuels. When plastic is not disposed of properly, it can end up in our oceans and waterways, where it can harm marine life and contribute to pollution. Recycling plastic can help to reduce the amount of plastic waste that enters our environment and reduce pollution. Plastic waste can harm wildlife in a number of ways, including entanglement and ingestion. By recycling plastic, we can reduce the amount of plastic waste that enters our environment and protect wildlife from harm. Recycling plastic requires less energy than producing new plastic from raw materials. By recycling plastic, we can save energy and reduce greenhouse gas emissions. There are many ways that individuals can promote plastic recycling in their daily lives. Here are some simple steps that you can take to make a difference: Reduce your use of plastic: The best way to reduce the amount of plastic waste that ends up in our landfills and oceans is to reduce your use of plastic products. Look for alternatives to single-use plastics, such as reusable bags, bottles, and containers. Make sure that you are recycling all of the plastic products that you use. Check with your local recycling center to find out what types of plastic are accepted and how to prepare them for recycling. Support recycling initiatives: Support local recycling initiatives and organizations like Project 33 that promote plastic recycling. Get involved in community clean-up events and encourage your friends and family to do the same. Spread the word about the importance of plastic recycling and encourage others to take action to reduce their carbon footprint. Promoting plastic recycling is one of the most effective ways to protect our planet and reduce our impact on the environment. By conserving resources, reducing pollution, protecting wildlife, and saving energy, recycling plastic has numerous benefits for both people and the planet. This Earth Day, let us commit to promoting plastic recycling and taking action to protect our planet for future generations.
A CNC metal cutting machine is part of a manufacturing process with computer numerical control (CNC) added to the machines, materials, and objects. This revolutionary way of manufacturing allows for precise, high speed production by automatically programming the motions and sequences. 5 Axis CNC Machining is a technique used for machining on machines that can be moved in all six degrees, or on some occasions, five. This process allows the operator to machine on any angle and multiple planes. There are several different configurations for this type of machining, with a large amount of them being patented by various companies. A simple explanation of this machining setup is that it allows the machine to move in two axes, both perpendicular to each other and independent of the spindle’s rotation. The first patents concerning CNC 5 Axis Machining surfaced around 1965 when Dyson Corp. patented them under control systems for prismatic parts. The patents for the most common 5 axis machine configurations were in the late 1970s when large companies such as Ford Motor Company, GE Aircraft Engines, and Hewlett-Packard began to patent their unique designs. Theory of Operation CNC 5 Axis Machining is similar to 3 Axis CNC machining with minor differences. The first difference is that there are two additional axes on the machine, where one is perpendicular to the Z-axis, and the other is perpendicular to both X and Y axes. These allow for tooling on multiple planes without having to reposition between cuts. The second difference between 3 Axis CNC machining and 5 Axis CNC machining is a rotational axis in the center of the machine tool. This allows for such movements as tilting, spinning, and rolling the workpiece. CNC 5 Axis machining is a very diverse area of technology that allows it to be used for many applications; some examples are detailed below: - Large pieces such as airplane wings and fuselages may be very large and heavy but still need to be machined on five planes. - High-speed machining for critical tolerances where the workpiece also requires good surface finishes and tolerances. - Machining on extremely narrow angles, such as cutting keyways in shafts using a rotary axis (roll only). - When very small tolerances are required for an application with no room to adjust the conventional 3 Axis CNC Machine components. - To produce parts with multiple open cavities or uncovered areas where a part can be mounted on a rotary axis to make enclosed parts with the openings facing up. - Machining small cavities and interlocking shapes in a single part without making a complex assembly of smaller components. It also reduces material scrap and makes assembly of the parts much easier. - Due to its adaptability, CNC 5 Axis machining can machine on five planes and multiple angles. This allows for a huge variety of applications, both aesthetically and functionally. It also allows for quick changes between programs when changing from one shape to another on the same plane. - Accuracy is not lost when machining complex shapes because all angles can be cut to the same level of accuracy without repositioning. - Ability to do high-speed machining for critical tolerances where the workpiece also requires good surface finishes and tolerances. - Aesthetic finishing of the part by machining patterns on curved surfaces. CNC 5 Axis machining is a large technology area with many applications. Due to its adaptability, it can be used in multiple applications. However, it does not excel in any particular application.
(A) Equation of Parallel Lines To find the equation of the straight line which passes through a given point and parallel to another straight line, follow the steps below: Step 1 : Let the equation of the straight line take the form y = mx + c. Step 2 : Find the gradient of the straight line from the equation of the straight line parallel to it. Step 3 : Substitute the value of gradient, m, the x-coordinate and y-coordinate of the given point into y = mx + c to find the value of the y-intercept, c. Step 4 : Write down the equation of the straight line in the form y = mx + c. Find the equation of the straight line that passes through the point (–8, 2) and is parallel to the straight line 4y + 3x = 12. (B) Equation of Parallel Lines (Sample Question) The straight lines MN and PQ in the diagram above are parallel. Find the value of q. If two lines are parallel, their gradients are equal. m1 = m2 mMN = mPQ 60 = 6q + 30 6q = 30 q = 5
The Common Core State Standards (CCSS) call for several Key Shifts in Language Arts that have implications across the curriculum. Listenwise can help teachers of many subjects address these shifts. Shift 1: Regular practice with complex texts and their academic language Listenwise audio stories are engaging complex texts full of academic language. They are authentic texts sourced from public radio, typical of those that students may encounter in their adult lives, and they are selected for their potential to support teachers and students in making connections between the curriculum and the world outside of school. Students can listen to each audio text multiple times, with or without reading interactive transcripts simultaneously, in order to deepen their understanding. Listenwise audio stories offer all students access to complex texts, regardless of reading level, which, in turn, can help students improve their reading skills. Lessons include selected academic vocabulary words to highlight, as well as comprehension questions and embedded text tools, which can support students’ understanding of the texts and also expand their vocabulary. Academic vocabulary appears in context within all Listenwise stories, providing opportunities for students to practice strategies for learning new words. This week’s current events, for example, include the following words: aftermath, democracy, archive, predatory, and disparity. Shift 2: Reading, writing, and speaking grounded in evidence from texts, both literary and informational Listenwise stories are selected for their relevance and interest value, as well as their potential to promote critical thinking and analysis. Stories featured in lessons and current events can provide rich fodder for high-level classroom discussion and/or analytic writing tasks. Text-dependent listening comprehension and discussion questions associated with each story invite students to listen closely to complex audio texts and interpret, analyze, synthesize, evaluate, or apply information, supporting their ideas or claims with evidence from the text. Quizzes include questions that ask students to identify supporting evidence for a specific claim within a text, so teachers can assess those skills and use the data to inform instruction. Lessons noted as including extra supports for English language learners contain close listening protocols, which can help to scaffold such learning activities. All current events and standards-aligned lessons, for instance, include text-dependent questions, such as these: - What did you learn from the story about the potential impact of a storm such as Hurricane Florence? Use details from the text to explain your answer. - Why does the anthropologist interviewed describe the fire as a “loss for mankind’? - How are predatory bacteria similar to other predators? Use details from the story to support your ideas. Shift 3: Building knowledge through content-rich nonfiction Podcasts featured in Listenwise current events and lessons provide content-rich nonfiction stories on a wide range of topics that can help students build background knowledge, which is critical to both listening and reading comprehension. The Listenwise team curates public radio stories based on their educational value and potential for engaging students, so the current events and lessons in the Listenwise platform offer a dynamic collection of high interest, highly relevant, high quality content that can be used instructionally in many ways. These content-rich nonfiction stories are written by skilled professional writers for a large audience that reaches far beyond the classroom, so they expose students to mentor informational texts about a host of captivating issues. One week’s current events, for example, addressed a variety of topics, including the social impact of hurricanes, democratic participation, research on using microbes to fight infections, the value of ancient artifacts, and the civic engagement of sports figures. Listenwise can help teachers address many Common Core standards across all four literacy strands: reading, writing, speaking, and listening. In addition, it can help to support teachers in attending to all of the “key shifts” in expectations embodied in the standards. If you are using Listenwise with your students in ways that help you address the CCSS key shifts, we would love to hear about it! If you are using the free version of Listenwise, try the 30-day free trial of Premium (click on the button in your dashboard) so that you can try all of the extra lesson supports, listening quizzes, and student accounts.
1. Roman Catholics in Constantinople/Istanbul From the early Middle Ages, individuals and groups of Roman Catholic (or Latin-rite) merchants, diplomats and adventurers were regularly, but only temporarily, present in Constantinople. The roots of the resident Latin-rite community, however, trace back to the eleventh century when Venice was granted permission to establish a commercial colony in recognition of its military support of the Byzantine emperors. In the subsequent centuries, and particularly following the fourth crusade in 1204, the Latin-rite presence grew exponentially. The two largest groups were the Venetians, who inhabited a quarter within Constantinople proper, and the Genoese, who occupied the suburb of Galata (also called Pera), facing the capital across the Golden Horn. In addition, there were also not insignificant communities of Catalans, Florentines, and Ragusans in the city. This was the heyday of Latin Christendom in Constantinople, evidenced by the thirty-five churches established there over the course of several centuries. 2. The Magnifica Comunità The situation of the Latin-rite community changed dramatically at the final Ottoman conquest of Constantinople in 1453. While the capital city experienced significant damage, Sultan Mehmed II generally spared Galata both in recognition of the inhabitants’ timely decision to cooperate during the final siege, and because he wanted to protect its significant commerce. Many of the Latin-rite inhabitants of Ottoman Istanbul fled both before and after its fall, however, a core group of families, primarily of Genoese extraction, remained. This small community was centered in Galata, and was known as the Magnifica Comunità (a very common term, used to describe communities existing in many cities under the Venetian realm). It was overseen by a council of twelve officials, who replaced the pre-conquest Genoese podestà, and was granted limited legal and ceremonial rights primarily associated with the administration of the Latin churches in greater Istanbul. Unlike other non-Muslim subject millets, or religious communities, the Magnifica Comunità was not accorded legal or political rights, but rather was under the administrative purview of Galata’s Ottoman officials.1 The geographical and spiritual focus of the Magnifica Comunità centered on the most important remaining Latin-rite church in the Ottoman capital, the cathedral of San Francesco in Galata. This was where the leaders of the community met, where communal and religious archives were preserved, it was the seat of the city’s most important confraternity, and was the home of a small community of Franciscans, the largest religious order still in the city. Other important religious sites included the Jesuit church of San Benedetto with its school and large library, San Giorgio with its Capuchin school, the hospital of San Giovanni, and the small chapel of Sant’Antonio Abbate whose miraculous waters (agiasmata) were universally renowned among the Roman Catholic, Orthodox and Muslim populations of Istanbul. 3. The Early Modern Era Throughout the Ottoman period, the Latin-rite community of Istanbul was very small, particularly in comparison with the Orthodox, Armenian, Jewish and other minorities. Several reports from the late sixteenth and early seventeenth centuries place the total number of Roman Catholic subjects of the sultans at 500 (approximately two dozen families). In addition, there were 2000 slaves, 500 freed slaves, and 700 merchants and embassy staff temporarily in the city. While these other groups numbers fluctuated significantly, the size of the Magnifica Comunità remained relatively unchanged until the nineteenth century.2 Because of their small numbers, the Latin-rite community had to struggle continuously to preserve its distinctive identity and to avoid being assimilated into Istanbul’s other, much larger populations. The distinctive dress of the Perots (as the indigenous Ottoman Roman Catholics were known), which included a high white collar and a unique cap for the men, and a Ragusan bonnet worn by the women, was a constant visual marker.3 Education was another mean of conserving religious identity: in the early modern period Jesuit and Capuchin schools were instituted in Galata at the community’s request to instruct and to catechize their children in Roman Catholic doctrine and practice. These schools also educated many non-Catholic children, and were an effective evangelical tool. Religion was a central element of the Latin-rite Ottomans’ identity, and an important aspect of this was the administration of the community’s sacred edifices and the perpetuation of its rituals. As the last vestiges of the Latin-rite community in the Ottoman capital, the rectors of the Magnifica Comunità ardently defended their right to govern the city’s Roman Catholic churches, confraternities, hospitals, and monasteries, as well as its ritual life of processions and holy feasts. This proved to be a source of recurring conflict between the Latin-rite community, its French and Venetian patrons, and the papacy. The primary issue was one of sovereignty: during Byzantine times, the Latin church in Constantinople was overseen by a patriarch selected by the pope. Following the Ottoman conquest, however, these patriarchs were no longer able to live in the city, and so patriarchal vicars were appointed, often from Venetian lands, to oversee the community’s churches and religious, as well as to ensure orthodoxy and obedience to Rome. While these patriarchal vicars in theory were the final authority in all religious matters pertaining to the Roman Catholic community, in practice they visited the city rarely, if ever. Thus the Magnifica Comunità - which claimed that Mehmed the Conqueror had awarded it dominion over Istanbul’s Latin-rite churches in a 1453 ahdname, or treaty - enjoyed significant de facto autonomy. The confused question of authority over the churches and religious matters in the Ottoman capital gave rise to regular jurisdictional disputes. In 1622, for example, Rome sought to assert its position by replacing the patriarchal vicar with a bishop, a move which the Magnifica Comunità strongly opposed. The conflict eventually came to a head in 1643 when the community was excommunicated, though only briefly. Despite their best efforts, over the course of the early modern period, the Magnifica Comunità dwindled as families died out, individuals immigrated to Europe, or more often assimilated into the larger Greek Orthodox and Muslim populations. An observer in 1582 estimated that the community had lost 400 households to the Orthodox alone, and while less common, conversion to Islam also enticed some. Intermarriage between the Roman Catholic and Orthodox (and occasionally the Muslim) communities was also so common that in 1627 the patriarchal vicar tried unsuccessfully to prohibit all such unions.4 Even if they did not convert or marry into Islam or Orthodoxy, the Latin-rite Ottomans fought a losing battle to maintain their distinctiveness. The seventeenth century traveller, Pietro della Valle, reported that they observed the Latin-rite, but in their “customs [...] are Grecisized [grecheggiano].”5 This process of assimilation was most evident linguistically, as Greek increasingly became the community’s primary spoken language, even as Italian continued as the official, administrative idiom. This gradual marginalization of the Latin-rite community accelerated over the course of the seventeenth century, as the Perots were gradually replaced by Greeks as diplomatic and commercial intermediaries during the period of the Phanariots. This process reached its culmination in 1682 when the last vestiges of the community’s nominal self-governance disappeared and the Magnifica Comunità passed completely under direct Ottoman administration. The gradual reduction of the Magnifica Comunità was offset by the immigration of some few Roman Catholics to Istanbul, but even more by conversions which resulted from the efforts of Jesuit and other missionaries who were active in Ottoman lands. Their work was necessarily limited to the non-Muslim population of the empire, and the bulk of conversions came from the Armenian community in Istanbul, many of whom were induced to convert through their association with Jesuit and Capuchin schools in Galata. Indeed, by 1700 there were 8,000 Armenian Catholics in the capital, who so far outnumbered the remains of the original Magnifica Comunità, that the label of Catholic came to signify specifically Armenians, while Latin or Frank was used to refer to Roman Catholics with European genealogies.6 4. Roman Catholics in the Final Century of the Ottoman Empire If the first three Ottoman centuries were characterized by a certain level of stasis, the nineteenth century brought significant change to Istanbul’s Roman Catholics. There was marked growth in the community as Italians, Spanish, Poles and other immigrants and refugees fled European troubles, and as Armenians and other eastern Christians continue to convert in relatively small numbers. There was as a concomitant increase in the number of clergy and nuns, who numbered almost 100 by mid-century, and a new church was constructed by the Capuchins in 1845. Galata also was home to a growing number of Roman Catholic primary and boarding schools for both boys and girls, which also attracted many Greek, Armenian, Muslim and Jewish students. By 1872 the number of Latin Catholics in Istanbul and its environs numbered approximately 22,000, divided among eleven parishes, with Armenian Catholics numbering over 30,000.7The dynamic political conditions in Europe and the Ottoman Empire in the nineteenth and early twentieth centuries significantly impacted Istanbul’s Latin-rite community. During the Greek revolt in the early nineteenth century, for a time Ottoman Catholics, along with other Christians, were viewed with suspicion, but by the Tanzimat era (1839-1876) concerns about Catholic loyalty had dissipated, and indeed some individuals obtained official positions of significant influence. Questions regarding the political loyalties of Ottoman Roman Catholics resurfaced with the Ottoman entry into World War I on the side of the Central Powers. The collapse of the Ottoman Empire, as well as the systematic massacre of the Armenians, jeopardized the situation of the empire’s Roman Catholics and led to a precipitous decline in its numbers. This was exacerbated during the post-war years when Istanbul was occupied by the allies, and during the four years of war which resulted in the declaration of the Turkish Republic in 1923. These events led to a dramatic reduction in the size of the Roman Catholic community to levels not seen since the sixteenth century: in 1927 it numbered only 3,400 individuals.8
This is an introductory LibGuide for researching the Dead Sea Scrolls (DSS). The discovery of the Dead Sea Scrolls in the 1940s and 1950s constitutes one of the most significant finds in the history of Biblical textual analysis. This extensive scroll library dates to late in the period of the Second Temple, which was destroyed in the year 68 C. E. Before the discovery of the Dead Sea Scrolls, the oldest known extant biblical manuscript was the Aleppo Codex, written almost a millennium later in the 10th century. Maimonides (1135-1204) writes that the Codex, now located in the Israel Museum in Jerusalem, was the most authoritative text of the Hebrew Bible in his time. For more on, please read this article on the significance of the DSS library in the Touro College Library Newsletter.
One of the reasons being attributed as to why Italy is the worst affected country in terms of mortality by the COVID-19, is it’s ageing population. It becomes important to know the population structure of Italy which can be studied from the Population Pyramid. OVID-19 disease-Italy is affected so badly because they have an ageing population.The high death rate in Italy has been attributed to the fact that the country has the world’s oldest population after Japan.Most of the death toll from Covid-19 have been individuals who are elderly and with previous health issues. What is a Population Pyramid? A Population Pyramid is a graph that shows the age-sex distribution of a given population. It a graphic profile of the population’s residents.A population pyramid, also called an “age-gender-pyramid“, is a graphical illustration that shows the distribution of various age groups in a population (typically that of a country or region of the world), which forms the shape of a pyramid when the population is growing.Males are conventionally shown on the left and females on the right, and they may be measured by raw number or as a percentage of the total population. This tool can be used to visualize and age of a particular population. It is also used in ecology to determine the overall age distribution of a population; an indication of the reproductive capabilities and likelihood of the continuation of a species. - Expansive – pyramid with a wide base (larger percentage of people in younger age groups, indicating high birth rates and high fertility rates) and narrow top (high death rate and lower life expectancies). It suggests a growing population. Example: Nigera Population Pyramid - Constrictive – pyramid with a narrow base (lower percentage of younger people, indicating declining birth rates with each succeeding age group getting smaller than the previous one). Example: United States - Stationary – with a somewhat equal proportion of the population in each age group. The population is stable, neither increasing nor decreasing. Interpreting Population Pyramids The shape of the population pyramid efficiently communicates considerable information about the age-sex structure of a specific population. A broad-based pyramid indicates that people in the younger age categories make up a relatively large proportion of the population, and a narrow or pointed top indicates that older people make up a relatively small proportion of the population. In the older age groups of many populations, the number of females is much greater than the number of males; this is reflected in the shape of the pyramid, such that the bars on the right side of the central axis (the female side) are longer than those on the left (male) side. The median age of the population would be the age group (bar) represented by the point on the vertical axis that equally divides the area within the pyramid (equal areas within the pyramid fall above and below the age represented by the bar). Fertility and mortality of the population are also reflected in the shape of the population pyramid. A broad base and sharply tapering sides (a true pyramid shape) reflects high fertility rates and high mortality rates in younger age groups. Irregularities in the profile of the population pyramid convey information about changes in the population or aberrations. A bulge or an indentation in the profile of the population pyramid may indicate unusually high fertility or mortality or changes in the population due to immigration or emigration. Population Pyramid of Italy 0-14 years: 13.45% (male 4,292,431/female 4,097,732) 15-24 years: 9.61% (male 3,005,402/female 2,989,764) Fertility in Italy A Total Fertility Rate (TFR) of 2.1 represents the Replacement-Level Fertility: the average number of children per woman needed for each generation to exactly replace itself without needing international immigration. A value below 2.1 will cause the native population to decline Population Pyramids And Demographic Transition Theory Demographers who have studied the historical changes in age and sex composition, fertility, and mortality of the world’s populations have articulated a theory of demographic transition. This theory provides a useful approximation of the historical changes that have taken place in populations in many different regions of the world. The stages of this transition are represented by dramatically different population pyramids. Theory of Demographic Transition is a theory that throws light on changes in birth rate and death rate and consequently on the growth-rate of population. Along with the economic development, tendencies of birth-rate and death rate are different. Because of it, growth rate of population is also different. “Demographic transition refers to a population cycle that begins with a fall in the death rate, continues with a phase of rapid population growth and concludes with a decline in the birth rate”-E.G. Dolan. According to this theory, economic development has the effect of bringing about a reduction in the death rate. The relationship between birth and death rates changes with economic development and a country has to pass through different stages of population growth. C.P. Blacker divided population into five types as high, stationary, early expanding, low stationary and diminishing. According to the theory of demographic transition, population growth will have to pass through these different stages during the course of economic development. The four stages of demographic transition mentioned by Max are explained as follows: This stage has been called high population growth potential stage. It is characterised by high and fluctuating birth and death rates which will almost neutralize each other. People mostly live in rural areas and their main occupation is agriculture which is in the stage of backwardness. The tertiary sector consisting of transport, commerce banking and insurance is underdeveloped. All these factors are responsible for low income and poverty of the masses. Social beliefs and customs play an important role in keeping birth rate high. Death rate is also high because of primitive sanitation and absence of medical facilities. People live in dirty and unhealthy surroundings. As a result, they are disease ridden and the absence of proper medical care results in large deaths. The mortality rate is highest among the poor. Thus, high birth rates and death rates remain approximately equal over time so that a static equilibrium with zero population growth prevails. It is called the stage of Population Explosion. In this stage the death rate is decreasing while the birth rate remains constant at a high level. Agricultural and industrial productivity increases, means of transport and communication develops. There is great mobility of labour. Education expands. Income also increases. People get more and better quality of food products. Medical and health facilities are expanded. During the stage economic development is speeded up due to individual and government efforts. Increased use of better technology, mechanization and urbanisation takes place. But there is no substantial change in the men, attitude of the people and hence birth rate stays high i.e., economic development has not yet started affecting the birth rate. Due to the widening gap between the birth and death rates, population grows at an exceptionally high rate and that is why it has been called the population explosion stage. This is an “Expanding” stage in population development where population grows at an increasing rate, as shown in figure, with the decline in death rate and no change in birth rate. It is also characterised as a population stage because the population continues to grow at a fast rate. In this stage, birth rate as compared to the death rate declines more rapidly. As a result, population grows at a diminishing rate. This stage witnesses a fall in the birth rate while the death rate stays constant because it has already declined to the lowest minimum. Birth rate declines due to the impact of economic development, changed social attitudes and increased facilities for family planning. Population continues to grow fast because death rate stops falling whereas birth rate though declining but remains higher than death rate. It is called the stage of stationary population. Birch rate and death rate are both at a low level and they are again near balance. Birth rate is approximately equal to death rate and there is little growth in population. It becomes more or less stationary at a low level. Population Pyramid India: India’s pyramid is bottom heavy i.e. the Indian population has a larger proportion of children, teenagers and young adults compared to China’s.
The National Aeronautics and Space Administration, better known as NASA, has been the space program for the U.S. government since it was established by the National Aeronautics and Space Act on July 29, 1958. Since then, Americans have seen man walk on the moon and explore the interstellar highways with more than 130 manned space flights on the various space shuttle missions alone. That's more than 1,200 days in outer space for the shuttle crews. The very way we look at outer space has been redefined ever since astronaut Neil Armstrong took his "one small step for man, one giant leap for mankind." Because of the prestige that comes with working for NASA, the space program has always attracted the top engineers and pilots and is known for consistently being on the leading edge of all kinds of technology. Over the years, regular civilians have benefitted from some of this technology. NASA has impacted our daily lives in more ways than most people imagine, from helping to improve artificial limbs as a result of foam technology to using lasers developed for monitoring gases in the atmosphere for heart surgery. There are dozens of instances where technological breakthroughs from NASA researchers have been used in the outside world. One of these is baby food. Read on find out how NASA has helped improve what you're feeding your newborn.
Graves' disease is an autoimmune disease characterized by a metabolic imbalance resulting from overproduction of thyroid hormones (thyrotoxicosis). It is named after Robert Graves, the 19th century Irish physician who first discovered the condition. In Graves' disease, the thyroid gland in the neck is diffusely enlarged and hyperactive, producing excessive thyroid hormones. Graves' disease can have an effect on many parts of the body such as the nervous system, eyes, skin, hair/nails, lungs, digestive system, muscles/bones and reproductive system. Graves' disease is eight times more common in women than in men, occurs most frequently between the ages of 20 and 40 and often arises after an infection or physical or emotional stress. It has a familial tendency. The disease is characterized by the formation of autoantibodies that bind to receptors in thyroid cell membranes and stimulate the gland to hyperfunction. Generally, the symptoms of Graves' disease are identical to the symptoms of hyperthyroidism, a condition that can be caused by Graves' disease. Classic symptoms include an enlarged thyroid gland (goiter), nervousness, heat intolerance, weight loss, sweating, diarrhea, tremors, palpitations and exophthalmos (swelling of the tissue behind the eyeballs causing protrusion of the eyeball). Graves' disease can also manifest with any or all of the following: - Shortness of breath - Pretibial myxedema (lumpy, reddish-colored thickening of the skin, usually on the shins) - Double vision - Muscle wasting - Increased eye tearing - Infrequent or absent menstrual periods - Abnormal breast enlargement (men) - Increased hair loss - Diminished sex drive - Brittle nails Thyroid storm, a complication of Graves' disease, may lead to life-threatening heart, liver, or kidney failure. Thyroid storm begins suddenly and may be caused by a stressful event. The signs and symptoms of thyroid storm include extreme irritability, high blood pressure, rapid heart rate, vomiting, high fever, delirium and coma. Left untreated, it can be fatal. In the examination, the doctor will look for a goiter (enlarged thyroid gland), a rapid pulse, tremor, and any other evidence of Graves' disease. Blood tests will be performed to assess thyroid function. Your physician may also order a radioactive-iodine uptake test and thyroid scan. These tests can help determine if the entire thyroid gland is overactive, or whether just a portion of the gland is overactive. The choice of treatment depends upon the age and overall condition of the patient, the size of thyroid gland, and patient preference. Currently, there are at least three methods of treatment: drugs that inhibit production of thyroid hormone or provide symptomatic relief, the use of radioactive iodine to destroy part of the thyroid gland and thereby reduce hormone production, or surgical removal of part of the gland. Your doctor will prescribe either methimazole (Tapazole) or propylthiouracil (PTU) pills. These drugs act to prevent the thyroid from manufacturing the thyroid hormone. The side effects of this medication may be drowsiness and minor lethargy; in rare cases, they can cause agranulocytosis, a blood disease. Most of the time, however, this form of therapy is safe and restores normal hormone balance within a couple of months. Another medication, propranolol, is a beta-blocker that helps relieve the symptoms of Graves' disease including rapid heart rate, tremor, sweating and anxiety. Iodinated contrast agents can also provide effective treatment for hyperthyroidism of any cause. Radioactive Iodine Therapy This is an alternative if drug treatment fails. You are given a capsule or a drink of water containing radioactive iodine. After being swallowed, the "radioiodine" is rapidly absorbed by the overactive thyroid cells and are destroyed by the radiation, so less thyroid hormone is produced. The radioactivity disappears from the body within days. You should not undergo radioactive iodine therapy if you are pregnant as the radiation can adversely affect a developing fetus. Thyroidectomy is surgical removal of all or part of the thyroid gland. If only a single lump or nodule within the thyroid is producing too much hormone, the surgeon can take out just that small part of the gland. If the entire gland is overactive, which is more often the case, a total thyroidectomy is needed. Surgery is the preferred treatment for people with a large goiter who chronically relapse after drug therapy, if there is a risk of cancer, and for people who refuse or are not candidates for radioactive iodine therapy, such as pregnant women. Depending on how much of the gland is left after surgery, you may need subsequent thyroid replacement therapy.
Students will use a word-processing program (and paint program or scanner, if available), to produce an illustrated dictionary of terms. - glossary of terms from chosen textbook - scanner (optional), or drawing utensils - coil binding machine (optional) - Students use word-processing program to lay-out and enter their terms and definitions. - Illustrations: students can illustrate using a computer draw program, scanning in hand-drawn images, or by drawing their images onto the finished printed product- depending on availability of resources. - Bind completed dictionary with staples, binding-machine, string, etc.
The Physics of Pressure Washers A popular brand of pressure washer claims to deliver 330 litres per hour of water at a pressure of 80 bar, drawing 1,400 W of electrical power in the process. Pressure washers of this type are made up of an electric motor that drives a small compressor to pressurize water fed into it through a garden hose. a.Show that the amount of power in the water flow when the washer is in operation is approximately 736 W. b.Calculate the efficiency with which the electrical input energy is converted to hydraulic energy in the water. c.List three significant contributory factors to this energy loss, and indicate which is likely to be the most important. d.Calculate the diameter of the output nozzle of the washer. e.Assuming all the pressure is dropped at the output nozzle, use its cross-sectional area to calculate the reaction force exerted on the user when the washer is in operation. f.Explain in a few words why, when operating a garden hose fitted with a trigger-operated nozzle, the water jet is momentarily more powerful at the instant the trigger is squeezed than later, when there is a continuous stream of water.© SolutionLibrary Inc. solutionlibary.com 9836dcf9d7 https://solutionlibrary.com/physics/fluid-dynamics/the-physics-of-pressure-washers-j5sl
A new tool lets astronomers ‘listen’ to the Universe for the first time. On the morning of 14 September 2015, a signal from two black holes that had collided 1.3 billion years ago reached Earth, alerting scientists around the world. “It took us a good part of the day to convince ourselves that this was not a drill”, says Professor Gabriela González. In fact, it was the first-ever detection of a gravitational wave and the latest development in the long history of astronomy. When Galileo first introduced the telescope in the 1600s, astronomers gained the ability to view parts of the Universe that were invisible to the naked eye. This led to centuries of discovery – as telescopes advanced, they exposed new planets, galaxies and even a glimpse of the very early Universe. In 2015, scientists gained another invaluable tool: the ability to ‘hear’ the cosmos through gravitational waves. Newton described gravity as a force. Thinking about gravity in this way can explain most of the phenomena that happen here on Earth. For example, the force of gravity acting on an apple makes it fall from a tree onto an unsuspecting person sitting below it. However, to understand gravity on a cosmic scale, we need to turn to Einstein, who described gravity as the bending of space-time itself. Some physicists describe this process using a bowling ball and a blanket. Imagine space-time as a blanket. A bowling ball placed at the centre of the blanket bends the fabric around it. The heavier an object is, the further it sinks. As you move the ball along the fabric, it produces ripples, much like a boat travelling through water. “The curvature is what makes Earth orbit the Sun – the Sun is a bowling ball in a fabric and it’s that bending in the fabric that makes the Earth go around”, explains González, who is the spokesperson for the Laser Interferometer Gravitational-Wave Observatory (LIGO) collaboration. Everything that has mass – planets, stars and people – pulls on the fabric of space-time and produces gravitational waves as it moves through space. These waves are passing through us all the time, but they are much too weak to detect. To find these elusive signals, physicists built LIGO, twin observatories in Louisiana and Washington, USA. At each L-shaped detector, a laser beam is split and sent down two 4 km arms. The beams reflect off the mirrors at each end and travel back to reunite. A passing gravitational wave slightly alters the relative lengths of the arms, shifting the path of the laser beam, creating a change that physicists can detect. Unlike telescopes, which are pointed toward very specific parts of the sky, detectors like LIGO scan a much larger area of the Universe and hear sources from all directions. “Gravitational waves detectors are like microphones”, says Laura Nuttall, a post-doctoral researcher at Syracuse University, USA. On that September morning in 2015, when the first gravitational wave passed through the two detectors, LIGO was still preparing for an observational run. Researchers were still running tests and diagnostics during the day – which is why they needed to conduct a large number of checks and analyses to make sure the signal was real. Months later, once researchers had meticulously checked the data for errors or noise (such as lightning or earthquakes), the LIGO collaboration announced to the world that they had finally reached a long-anticipated goal: almost 100 years after Einstein first predicted the existence of gravitation waves, scientists had detected them. A few months after the first signal arrived, LIGO detected yet another black-hole collision. “Finding a second one proves that there’s a population of sources that will produce detectable gravitational waves”, Nuttall says. “We are actually an observatory now.” Many have dubbed the detection as the dawn of the age of gravitational-wave astronomy. Scientists expect to see hundreds, maybe even thousands, of these binary black holes in the years to come. Gravitational-wave detectors will also allow astronomers to look much more closely at other astronomical phenomena, such as neutron stars, supernovae and even the Big Bang. One important next step is to detect the optical counterparts – such as light from the surrounding matter or gamma-ray bursts – of the sources of gravitational waves. To do this, astronomers need to point their telescopes to the area of the sky where the gravitational waves came from to find any detectable light. Currently, this feat is like finding a needle in a haystack. Because the field of view of gravitational-wave detectors is much, much larger than telescopes, it is extremely difficult to connect the two. “Connecting gravitational waves with light for the first time will be such an important discovery that it’s definitely worth the effort”, says Edo Berger, an astronomy professor at Harvard University. LIGO is only one of several gravitational-wave observatories. Other ground-based observatories, such as Virgo in Italy, KAGRA in Japan and the future LIGO India have similar sensitivities to LIGO. There are also other approaches that scientists are using – and plan to use in the future – to detect gravitational waves at completely different frequencies. The evolved Laser Interferometer Space Antenna (eLISA), for example, is a gravitational-wave detector that physicists plan to build in space. Once complete, eLISA will be composed of three spacecraft that are over a million kilometres apart, making it sensitive to much lower gravitational-wave frequencies, where scientists expect to detect supermassive black holes. Pulsar array timing is a completely different method of detection. Pulsars are natural timekeepers, regularly emitting beams of electromagnetic radiation. Astronomers carefully measure the arrival time of the pulses to find discrepancies, because when a gravitational wave passes by, space-time warps, changing the distance between us and the pulsar, causing the pulses to arrive slightly earlier or later. This method is sensitive to even lower frequencies than eLISA can detect. These and many other observatories will reveal a new view of the Universe, helping scientists to study phenomena such as merging black holes, to test theories of gravity and possibly even to discover something completely unexpected, says Daniel Holz, a professor of physics and astronomy at the University of Chicago. “Usually in science you’re just pushing the boundaries a little bit, but in this case, we’re opening up a whole new frontier.” This article is reproduced with kind permission of Symmetry magazinew1, in which it was originally published.
Wildfires are uncontrolled flames in woodlands, brush or open fields. Approximately 9,000 wildfires occur in Canada each year, destroying roughly 2.5 million hectares of land. That’s ten times the size of Vancouver Island. As wildfires and forest fires cause billions of dollars in property damage every year and displace families from their homes, it is essential to know how to help prevent and prepare for wildfires. - Always pay close attention, and respect fire bans, advisories and warnings before starting any fire. - Prepare any fire that you start very carefully and place a firebreak around the perimeter of the area. Never leave a fire unattended. Always have a water source handy. - Do not burn campfires in windy conditions. - If you smoke, do not discard smoking materials, like cigarette butts, from your car onto the roadway. - Lawn and farm equipment should be regularly maintained and have properly working spark arrestors to prevent sparks from exiting through the exhaust pipes. - Ensure your chimney is cleaned regularly and screened in with the appropriate, approved spark arrestors. - Screen in your eavestroughs to help prevent leaves and other debris from collecting inside them. If left open they can serve as a flammable place for airborne sparks and embers to land. Be prepared for wildfire - Make sure your home is insured and you have the proper coverage and a home inventory in place to protect it and all of your belongings. - Create and maintain an emergency preparedness plan and kit so you are ready to evacuate at any time when you see or learn of a fire approaching. - Keep grass mowed and watered, and remove any kind of dry vegetation from your yard since it is flammable. This includes rotted trees and shrubs, deadfall, and woodpiles. Keep firewood and other sources of fuel at least 10 meters away from the walls of your home. - Ensure all family members know your evacuation plan, and what to do if their clothes catch on fire. Practice the Stop, Drop and Roll. - Install smoke detectors on every floor of your home. Test them monthly and be sure to replace the batteries when you change your clocks in the spring and fall. - Keep a fire extinguisher on each level of your home. If you live in an area with a high risk of wildfires, consider using fire-resistant materials on your home. For example, you may want to replace an untreated wood shake roof with more fire-resilient materials like: - Treated shakes The most fire-resistant materials for walls are: Tempered glass is the most fire-resistant type of glass. Double or thermal pane window construction provides moderate protection. These tips are good start, but you should also consult with your local fire department for advice specific to your community. For more information on wildfires, visit the National Resources Canada website and see The Institute for Catastrophic Loss Reduction Wildfire brochure.
Presentation on theme: "Chapter 9 Ionic and Covalent Bonding. 9 \| 2 Contents and Concepts Ionic Bonds Molten salts and aqueous solutions of salts are electrically conducting."— Presentation transcript: 9 \| 2 Contents and Concepts Ionic Bonds Molten salts and aqueous solutions of salts are electrically conducting. This conductivity results from the motion of ions in the liquids. It suggests the possibility that ions exist in certain solids, held together by the attraction of ions of opposite charges. 1. Describing Ionic Bonds 2. Electron Configurations of Ions 3. Ionic Radii 9 \| 3 Covalent Bonds Not all bonds can be ionic. Hydrogen, H 2, is a clear example in which there is a strong bond between two like atoms. The bonding in the hydrogen molecule is covalent. A covalent bond forms between atoms by the sharing of a pair of electrons. 4. Describing Covalent Bonds 5. Polar Covalent Bonds; Electronegativity 6. Writing Lewis Electron-Dot Formulas 7. Delocalized Bonding: Resonance 8. Exceptions to the Octet Rule 9. Formal Charge and Lewis Formulas 10. Bond Length and Bond Order 11. Bond Energy 9 \| 4 Learning Objectives Ionic Bonds 1.Describing Ionic Bonds a.Define ionic bond. b.Explain the Lewis electron-dot symbol of an atom. c.Describe the energetics of ionic bonding. d.Define lattice energy. e.Describe the Born–Haber cycle to obtain a lattice energy from thermodynamic data. f.Describe some general properties of ionic substances. 9 \| 5 2.Electron Configurations of Ions a.State the three categories of monatomic ions of main-group elements. b.Write the electron configuration and Lewis symbol for a main-group ion. c.Note the polyatomic ions given earlier in Table 9.2. d.Note the formation of +2 and +3 transition- metal ions. e.Write the electron configurations of transition-metal ions. 9 \| 7 Covalent Bonds 4.Describing Covalent Bonds a.Describe the formation of a covalent bond between two atoms. b.Define Lewis electron-dot formula. c.Define bonding pair and lone (nonbonding) pair of electrons. d.Define coordinate covalent bond. e.State the octet rule. f.Define single, double, and triple bond. 9 \| 8 5.Polar Covalent Bonds; Electronegativity a.Define polar covalent bond. b.Define electronegativity. c.State the general periodic trends in electronegativity. d.Use electronegativity to obtain relative bond polarity. 6.Writing Lewis Electron-Dot Formulas a.Write Lewis formulas having single bonds. b.Write Lewis formulas having multiple bonds. c.Write Lewis formulas for ionic species. 9 \| 9 7.Delocalized Bonding: Resonance a.Define localized bonding. b.Define resonance description. c.Write resonance forms. 8.Exceptions to the Octet Rule a.Write Lewis formulas (exceptions to the octet rule). b.Note exceptions to the octet rule in Group IIA and Group IIIA. 9 \| 10 9.Formal Charge and Lewis Formulas a.Define formal charge. b.State the rules for obtaining the formal charge. c.State two rules useful in writing Lewis formulas. d.Use formal charges to determine the best Lewis formula. 9 \| 11 10. Bond Length and Bond Order a.Define bond length (bond distance). b.Define covalent radii. c.Define bond order. d.Explain how bond order and bond length are related. 11. Bond Energy a.Define bond energy. b.Estimate H from bond energies. 9 \| 12 A chemical bond is a strong attractive force that exists between certain atoms in a substance. There are three types of chemical bonds: Ionic bonds Covalent bonds Metallic bonds 9 \| 13 An ionic bond is a chemical bond formed by the electrostatic attraction between positive and negative ions. 9 \| 14 An ionic bond forms when one or more electrons are transferred from the valence shell of one atom to the valence shell of another atom. Na ([Ne]3s 1 ) + Cl ([Ne]3s 2 3p 5 ) Na + ([Ne]) + Cl - ([Ne]3s 2 3p 6 ) The atom that transferred the electron(s) becomes a cation. The atom that gained the electron(s) becomes an anion. 9 \| 15 A Lewis electron-dot symbol is a notation in which the electrons in the valence shell of an atom or ion are represented by dots placed around the chemical symbol of the element. Note: Dots are placed one to a side, until all four sides are occupied. 9 \| 16 Table 9.1 illustrates the Lewis electron-dot symbols for second- and third-period atoms. ? 9 \| 17 Represent the transfer of electrons in forming calcium oxide, CaO, from atoms. + Ca 2+ Ca O + O 2- ] [ 9 \| 18 Let’s look next at the energy involved in forming ionic compounds. The energy to remove an electron is the ionization energy. The energy to add an electron is the electron affinity. 9 \| 19 The combination of ionization energy and electron affinity is still endothermic; the process requires energy. However, when the two ions bond, more than enough energy is released, making the overall process exothermic. 9 \| 20 The lattice energy is the change in energy that occurs when an ionic solid is separated into gas- phase ions. It is very difficult to measure lattice energy directly. It can be found, however, by using the energy changes for steps that give the same result. 9 \| 21 For example, to find the lattice energy for NaCl, we can use the following steps. 9 \| 22 The process of finding the lattice energy indirectly from other thermochemical reactions is called the Born–Haber cycle. 9 \| 23 Ionic substances are typically high-melting solids. There are two factors that affect the strength of the ionic bond. They are given by Coulomb’s law: The higher the ionic charge, the stronger the force; the smaller the ion, the stronger the force. 9 \| 24 Based on this relationship, we can predict the relative melting points of NaCl and MgO. The charge on the ions of MgO is double the charge on the ions of NaCl. Because the charge is double, the force will be four times stronger. The size of Na + is larger than that of Mg 2+ ; the size of Cl - is larger than that of O 2-. Because the distance between Mg 2+ and O 2- is smaller than the distance between Na + and Cl -, the force between Mg 2+ and O 2- will be greater. 9 \| 25 Based on the higher charge and the smaller distance for MgO, its melting point of MgO should be significantly higher than the melting point of NaCl. The actual melting point of NaCl is 801°C; that for MgO is 2800°C. 9 \| 26 When we examine the electron configuration of main-group ions, we find that each element gains or loses electrons to attain a noble-gas configuration. ? 9 \| 27 Give the electron configuration and the Lewis symbol for the chloride ion, Cl -. Cl - ] [ For chlorine, Cl, Z = 17, so the Cl - ion has 18 electrons. The electron configuration for Cl - is 1s21s2 2s22s2 2p62p6 3s23s2 3p63p6 The Lewis symbol for Cl - is 9 \| 28 Group IIIA to VA metals often exhibit two different ionic charges: one that is equal to the group number and one that is 2 less than the group number. The higher charge is due to the loss of both the s subshell electrons and the p subshells electron(s). The lower charge is due to the loss of only the p subshell electron(s). For example, in Group IVA, tin and lead each form both +4 and +2 ions. In Group VA, bismuth forms +5 and +3 ions. 9 \| 29 Polyatomic ions are atoms held together by covalent bonds as a group and that, as a group, have gained or lost one or more electron. 9 \| 30 Transition metals form several ions. The atoms generally lose the ns electrons before losing the (n – 1)d electrons. As a result, one of the ions transition metals generally form is the +2 ion. ? 9 \| 31 Give the electron configurations of Mn and Mn 2+. Manganese, Z = 25, has 25 electrons;. Its electron configuration is 1s21s2 2s22s2 2p62p6 3s23s2 3p63p6 4s24s2 3d53d5 Mn 2+ has 23 electrons. When ionized, Mn loses the 4s electrons first; the electron configuration for Mn 2+ is 1s21s2 2s22s2 2p62p6 3s23s2 3p63p6 3d53d5 9 \| 33 a.Fe 2+ : [Ar]3d 4 4s 2 No. The 4s 2 electrons would be lost before the 3d electrons. b.N 2- : [He]2s 2 2p 5 No. Nitrogen will gain three electrons to fill the shell, forming N 3-. c.Zn 2+ : [Ar]3d 10 Yes! d.Na 2+ : [He]2s 2 2p 5 No. Sodium will lose only its one valence electron, forming Na +. e.Ca 2+ : [Ne]3s 2 3p 6 Yes! 9 \| 34 Ionic radius is a measure of the size of the spherical region around the nucleus of an ion within which the electrons are most likely to be found. While ionic radius, like atomic radius, can be somewhat arbitrary, it can be measured in ionic compounds. 9 \| 35 A cation is always smaller than its neutral atom. An anion is always larger than its neutral atom. 9 \| 36 The term isoelectronic refers to different species having the same number and configuration of electrons. For example, Ne, Na +, and F - are isoelectronic. Ionic radius for an isoelectronic series decreases with increasing atomic number. ? 9 \| 37 Using the periodic table only, arrange the following ions in order of increasing ionic radius: Br -, Se 2-, Sr 2+. 35 Br 34 Se 38 Sr These ions are isoelectronic, so their size decreases with increasing atomic number: Sr 2+ < Br - < Se 2- 9 \| 38 A covalent bond is a chemical bond formed by sharing a pair of electrons. 9 \| 39 To consider how a covalent bond forms, we can monitor the energy of two isolated hydrogen atoms as they move closer together. The energy decreases—first gradually, and then more steeply—to a minimum. As the atoms continue to move closer, it increases dramatically. The distance between the atoms when energy is at a minimum is called the bond length. This is illustrated on the following graph, from right to left. 9 \| 41 As the hydrogen atoms move closer together, the electron of each atom is attracted to both its own nucleus and the nucleus of the second atom. The electron probability distribution illustrates this relationship. 9 \| 42 A formula using dots to represent valence electrons is called a Lewis electron-dot formula. An electron pair is represented by two dots. A electron pair that is between two atoms is a bonding pair. It can also be represented by one line for each bonding pair. Electron pairs that are not bonding are nonbonding, or lone pair electrons. 9 \| 43 A coordinate covalent bond is formed when both electrons of the bond are donated by one atom. The two electrons forming the bond with the hydrogen on the left were both donated by the nitrogen. Once shared, they are indistinguishable from the other N—H bonds. 9 \| 44 In forming covalent bonds, atoms tend toward having a full eight electrons in their valence shell. This tendency is called the octet rule. Hydrogen is an exception to the octet rule: it has two electrons in its valence shell (a duet). 9 \| 45 A single bond is a covalent bond in which one pair of electrons is shared by two atoms. A double bond is a covalent bond in which two pairs of electrons are shared by two atoms. A triple bond is a covalent bond in which three pairs of electrons are shared by two atoms. Double bonds form primarily with C, N, and O. Triple bonds form primarily with C and N. 9 \| 46 A polar covalent bond (or polar bond) is a covalent bond in which the bonding electrons spend more time near one atom than near the other atom. Electronegativity, X, is a measure of the ability of an atom in a molecule to draw bonding electrons to itself. Electronegativity is related to ionization energy and electron affinity. 9 \| 47 Electronegativity increases from left to right and from bottom to top in the periodic table. F, O, N, and Cl have the highest electronegativity values. 9 \| 48 The difference in electronegativity between the two atoms in a bond is a rough measure of bond polarity. When the difference is very large, an ionic bond forms. When the difference is large, the bond is polar. When the difference is small, the bond is nonpolar. ? 9 \| 49 Using electronegativities, arrange the following bonds in order by increasing polarity: C—N, Na—F, O—H. For Na—F, the difference is 4.0 (F) – 0.9 (Na) = 3.1. For C—N, the difference is 3.0 (N) – 2.5 (C) = 0.5. For O—H, the difference is 3.5 (O) – 2.1 (H) = 1.4. C—N < Bond polarities: O—H < Na—F 9 \| 50 Writing Lewis Electron-Dot Formulas 1.Calculate the number of valence electrons. 2.Write the skeleton structure of the molecule or ion. 3.Distribute electrons to the atoms surrounding the central atom or atoms to satisfy the octet rule. 4.Distribute the remaining electrons as pairs to the central atom or atoms. ? 9 \| 51 Write the electron dot formulas for the following: a.OF 2 b.NF 3 c.NH 2 OH, hydroxylamine 9 \| 52 Count the valence electrons in OF 2 : O1(6) F2(7) 20 valence electrons O is the central atom (it is less electronegative). Now, we distribute the remaining 16 electrons, beginning with the outer atoms. The last four electrons go on O. 9 \| 53 Count the valence electrons in NF 3 : N1(5) F3(7) 26 valence electrons N is the central atom (it is less electronegative). Now, we distribute the remaining 20 electrons, beginning with the outer atoms. The last two electrons go on N. 9 \| 54 Count the electrons in NH 2 OH: N1(5) H3(1) O1(6) 14 valence electrons N is the central atom. Now, we distribute the remaining six electrons, beginning with the outer atoms. The last two electrons go on N. ? 9 \| 55 Write electron-dot formulas for the following: a. CO 2 b. HCN 9 \| 56 Count the electrons in CO 2 : C1(4) O2(6) 16 valence electrons C is the central atom. Now, we distribute the remaining 12 electrons, beginning with the outer atoms. Carbon does not have an octet, so two of the lone pairs shift to become a bonding pair, forming double bonds. 9 \| 57 Count the electrons in HCN: H1(1) C1(4) N1(5) 10 valence electrons. C is the central atom. The remaining electrons go on N. Carbon does not have an octet, so two of the lone pairs shift to become a bonding pair, forming a triple bond. ? 9 \| 58 Phosphorus pentachloride exists in solid state as the ionic compound [PCl 4 ] + [PCl 6 ] - ; it exists in the gas phase as the PCl 5 molecule. Write the Lewis formula of the PCl 4 + ion. 9 \| 59 Count the valence electrons in PCl 4 + : P1(5) Cl4(7) 32 P is the central atom. The remaining 24 nonbonding electrons are placed on Cl atoms. Add square brackets with the charge around the ion. 9 \| 60 Delocalized bonding is a type of bonding in which a bonding pair of electrons is spread over a number of atoms rather than being localized between two atoms. 9 \| 61 A single electron-dot diagram cannot properly describe delocalized bonding. Using the resonance description, the electron structure of a molecule or ion having delocalized bonding is given by writing all possible electron-dot formulas. They are connected with a double-headed arrow. ? 9 \| 62 Draw the resonance formulas of the acetate ion, CH 3 COO -. 9 \| 63 CH 3 COO - Valence electrons: 2(4) + 3(1) + 2(6) + 1 = 24 C is the central atom. A double bond is needed between C—O. There are two equivalent places for it, so two resonance structures are required. 9 \| 64 Some molecules have electron-dot structures that do not satisfy the octet rule. Some have an odd number of electrons, such as NO. Other molecules either have too few or too many electrons around the central atom. 9 \| 65 Elements that have too few electrons are in Groups IIA and IIIA. Be, B, and Al exhibit too few electrons around the central atom. 9 \| 66 There are many more examples of central atoms with more than an octet. Because elements of the third period and beyond have a d subshell, they can expand their valence electron configurations. S, P, Cl (as a central atom), and other elements in period 3 are examples of atoms in this situation. Elements in the second period, having only s and p subshells, are unable to do this. ? 9 \| 67 Give the Lewis formula of the IF 5 molecule. 9 \| 68 Count the valence electrons in IF 5 : I1(7) F5(7) 42 valence electrons I is the central atom. Thirty-two electrons remain; they first complete F octets. The remaining electrons go on I. 9 \| 69 The formal charge on an atom in the Lewis formula is the hypothetical charge you obtain by assuming that bonding electrons are equally shared between bonded atoms and that the electrons of each lone pair belong completely to one atom. 9 \| 70 Formal charge = valence electrons on free atom – ½ (number of electrons in bonds) – (number of lone-pair electrons) The sum of the formal charges on the atoms equals the charge on the formula. 9 \| 71 Formal charges can help to determine the most likely electron-dot formula using three rules: 1.Whenever you can write several Lewis formulas for a molecule, choose the one having the lowest magnitudes of formal charges. 2.When two proposed Lewis formulas have the same magnitudes of formal charges, choose the one having the negative formal charge on the more electronegative atom. 3.When possible, choose Lewis formulas that do not have like charges on adjacent atoms. ? 9 \| 72 Compare the formal charges for the following electron-dot formulas of CO 2. For the left structure:For the right structure: O:6 – 2 – 4 = 0 C:4 – 4 – 0 = 0 The left structure is better. Formal charge = group number – (number of bond pairs) – (number of nonbonding electrons) C:4 – 4 – 0 = 0 O:6 – 1 – 6 = –1 O:6 – 3 – 2 = +1 9 \| 73 Bond length (or bond distance) is the distance between nuclei in a bond. Bond order is, defined in terms of the Lewis formula, the number of pairs of electrons in a bond. Bond length decreases as bond order increases. ? 9 \| 74 Consider the propylene molecule: 134 pm 150 pm The shorter bond is the double bond; the longer bond is the single bond. One of the carbon–carbon bonds has a length of 150 pm; the other 134 pm. Identify each bond with a bond length. 9 \| 75 Bond energy is the average enthalpy change for breaking the A—B bond in a molecule in the gas phase. Bond energy is a measure of bond strength: the larger the bond energy, the stronger the bond. 9 \| 76 Bond energies can be used to estimate the enthalpy change, H, for a reaction. To do so, we imagine the reaction in two steps: breaking bonds and forming new bonds. H = sum of the bond energies for bonds broken – sum of the bond energies for bonds formed When H is negative, heat is released. When H is positive, heat is absorbed. ? 9 \| 77 Estimate the enthalpy change for the following reaction, using bond energies: Bonds Broken: 1 C=C602 kJ 1 Cl—Cl 240 kJ Absorbed842 kJ Bonds Formed: 1 C—C 346 kJ 2 C—Cl 654 kJ Released1000 kJ H = 842 kJ – 1000 kJ H = –158 kJ
- If Cá is followed by a noun or adjective that begins with a vowel, then that word gets a prefixed H, e.g. Cá haois í? (“What age is she?”), Cá hard é? (“How high is it?”). - In meaning, they’re practically synonymous. At most, the difference between cá háit and cén áit is the difference between “what place” and “which place”. The linguistic term is h-prothesis (similarly, the t- is called a t-prothesis. "Prothesis" is really the more correct term over "prefix" as a prefix would change the word' s meaning (like turn and return, changed and unchanged, and so on), while a prothesis does not change the word's meaning.
An exhibit exploring Chinese American participation in the China Burma India (CBI) Theater of World War II When the United States entered World War II after the Japanese attack on Pearl Harbor, December 7, 1941, China had already been at war with Japan for ten years. Chinese Americans had supported China’s lone fight, raising money for her defense and protesting the export of scrap iron and other material from the U.S. to Japan. At last America would recognize the importance of the Chinese role in the war in keeping large segments of Japanese armed forces occupied in China. Chinese Americans in CBI is a largely untold story in a forgotten chapter of World War II. Moreover, it is part of the larger story of how Chinese Americans, along with so many communities of color and women, contributed to the defeat of fascism abroad and to a new phase in the struggle for civil rights and social justice here at home. Chinese Americans who lived through the period remember it proudly as a turning point in their empowerment in our society and participation to the fullest in a double victory. Duty Honored: Call for Chinese American Stories Did you or your family member serve during World War II? CHSA is building a digital component to its exhibition. We would like to include more biographies of those who served during World War II, either abroad or on the homefront. Please send a biography of the serviceperson (no more than 120 words) with 1-3 images to [email protected]. The biography should note the person’s full name, rank (with military branch), birth year and year of death (if the person has passed), what the person did during the war, and what the person did after the war. Also, send the credit information for all media files. We will review the materials and if approved, add them to our digital platform. Exhibit sponsored by: Chinese Historical Society of America, National Parks Service, Golden Gate National Parks Conservancy, Asian Improv arts with Lenora Lee Dance, and API Cultural Center. This project was made possible with support from California Humanities, a non-profit partner of the National Endowment for the Humanities. Visit calhum.org. Any views, findings, conclusions, or recommendations expressed in these programs and exhibit do not necessarily represent those of California Humanities or the National Endowment for the Humanities. Buy the Called to Rise companion book commemorating the 75th anniversary of World War II
NASA will hold a briefing today (Sept. 26) on new findings about "activity that may be related to the presence of a subsurface ocean on Europa." Jupiter's moon Europa is often touted as a possible abode for life, because of the potential liquid water ocean beneath its icy surface. But how much do we know about Europa, really? There is a lot of indirect evidence for a liquid ocean of some sort, said Cynthia Phillips, a Europa project staff scientist at the Jet Propulsion Laboratory. You can follow NASA's Europa briefing here beginning at 2 p.m. EDT (1800 GMT). "We're almost certain one is there," she told Space.com. "One clue was the mass of Europa. Combined with when we measure the density, we get a figure close to one [gram per cubic centimeter] and water is the only material like that." [Does Europa Have 2X Earth's Liquid Water? Very Likely! (NASA Video)] Another big indicator was the way Europa interacted with Jupiter's magnetic field, as measured by the Galileo probe, which explored Jupiter in the 1990s. "The way we know some is liquid was [the probe's] magnetometer," Phillips said. "As [Europa] goes through Jupiter's field the magnetometer saw deflection exactly where you would expect if there were an induced field." The only way to get such an induced field is if there's some substance that is globally connected, and conductive — and only salty water fits the bill. Phillips noted you wouldn't get the same readings with isolated pools of water, like what's found under ice sheets on Earth. Slushy water-ice mixtures don't work, either. "Maybe graphite could get you that, but that would be ridiculous." she said, given what scientists know about how planets formed in that part of the solar system. The Europan surface also offers evidence for liquid-water oceans. First, spectroscopic measurements have showed that the surface is covered in water ice, and that it is smoother than a cue ball. "None of the topography is more than a couple of hundred meters tall," Philips said. That doesn't mean it's flat like a tabletop or frozen lake, though — it's actually quite chaotic and rough, at least at small scales. At the same time, the surface lacks impact craters. Phillips noted that given the rate of cratering on all the surrounding moons, Europa's surface doesn't look like it is more than 50 million years old. That means there is some way the planet is getting resurfaced relatively often. If the moon were covered with ice and had only a rock layer underneath it, you'd expect a much older-appearing surface. What few craters astronomers have found show that the ice surface is at least a few miles thick, because some craters have central peaks and there's a minimum thickness necessary to support those, Phillips said. A big question is exactly how thick the ice is and how thick the liquid layer is. Most estimates, Phillips said, are from 80 to 170 kilometers (50 to 100 miles) of water topped with several kilometers of ice. Phillips added that even though there's lots of indirect evidence for the moon's subsurface ocean, direct evidence is lacking. The closest thing to that was a Hubble Space Telescope observation in 2013, when astronomers saw what they thought might be a plume of water venting from the surface. But it wasn't conclusive. The real "smoking gun" of a water ocean will have to come from direct observations, she said. The European Space Agency and NASA both plan missions in the future to study the moons more closely. The ESA's Jupiter Icy Moon mission (JUICE) and NASA's planned Europa orbiter will both have radar, which will settle the issue. "I'll feel much better when we go there and turn the radar on," she said.
Kids, learn how to draw the Flower by following the steps below.Step:1 Draw a medium shaped circle at the center of the paper. Draw a small curvy line projecting outwards from any point on the circle. Draw similar line on other side connecting the step 2 curvy line and outer edge of bigger circle. Follow the above two steps (steps 2 and 3) to draw the flower second petal. Repeat the Step 2 and Step 3 to draw the third petal of the flower. Follow the above two steps (steps 2 and 3) to draw petals covering the circle. The number of petals depend on the size of the circle. Draw a small and slightly curved line in the middle of each petal, touching the bigger circle. Finally mark random dark dots inside the circle to show the pollen of the flower. Now the flower is ready for you to colour.
Earthshine used to test life detection method DR EMILY BALDWIN Posted: 29 February 2012 By imagining the Earth as an exoplanet, scientists observing our planet's reflected light on the Moon with ESO's Very Large Telescope have demonstrated a way to detect life on other worlds. “The Sun shines on the Earth and this light is reflected back to the surface of the Moon,” explains ESO's Michael Sterzik, lead author of the paper featured in the 1 March issue of the journal Nature. “The lunar surface acts as a giant mirror and reflects the Earth’s light back to us – and this is what we have observed with the VLT.” This view shows the thin crescent Moon setting over ESO’s Paranal Observatory in Chile, home of the VLT. As well as the bright crescent the rest of the disc of the Moon can be seen as earthshine. By observing this light, which is sunlight reflected off the Earth, astronomers can study the Earth as if it were an exoplanet and search for signs of life. Mercury and Venus are also seen in this image, taken on 27 October 2011. Image: ESO/B. Tafreshi/TWAN. Earth's reflected light onto the Moon – earthshine – can easily be seen with the naked eye when the Moon appears as a thin crescent in the night sky. As well as the bright crescent, the full disc of the Moon is also visible, dimly lit by Earth's light. The team looked at the polarisation of the reflected light to demonstrate how a planet that hosts life would look when observed from space. They conclude that Earth's atmosphere is partly cloudy, has oceans and that there is vegetation. Changes in cloud cover and amount of vegetation could also be deduced as different parts of the Earth reflected light towards the Moon. “The light from a distant exoplanet is overwhelmed by the glare of the host star, so it’s very difficult to analyse – a bit like trying to study a grain of dust beside a powerful light bulb,” says co-author Stefano Bagnulo from Armagh Observatory, Northern Ireland. “But the light reflected by a planet is polarised [i.e. it oscillates in a specific direction], while the light from the host star is not. So polarimetric techniques help us to pick out the faint reflected light of an exoplanet from the dazzling starlight.” The work marks an important step in the ability to detect signs of life elsewhere in the Universe, but there is a long road ahead before ground-based telescopes have the sensitivity to pick out the finest details of a distant world. "Current instruments, including the forthcoming SPHERE instrument of the VLT may allow a rough characterisation of the atmosphere of a large exoplanet in close orbit around its star," Bagnulo tells Astronomy Now. "Only the E-ELT (European Extremely Large Telescope), with its collecting area more than 20 times larger than that of the VLT, will permit a more refined characterisation of the surfaces and atmospheres of the planets. However, for an Earth-like planet, the detection of the fine structure presented in our paper, and in particular oxygen and vegetation features, will be extremely difficult even with the E-ELT." HOME \| NEWS ARCHIVE \| MAGAZINE \| SOLAR SYSTEM \| SKY CHART \| RESOURCES \| STORE \| SPACEFLIGHT NOW © 2014 Pole Star Publications Ltd.
Closing parts of the ocean to fishing to preserve fish stocks holds great intuitive appeal. Similar resource management tools have been used as far back as the Middle Ages, when European kings and princes controlled access to forests and streams, and the fish and wildlife in them. In Hawaii, local chiefs established and maintained networks of no-fishing “kapu” zones, with violations punishable by death. Today, Marine Protected Areas, or MPAs—areas of the ocean temporarily or permanently closed to harvesting—are being proposed to restrict not only fishing, but also mineral and hydrocarbon extraction, and other activities. Some advocates of MPAs suggest that at least 20 percent of the coastal and open ocean should be set aside and permanently zoned to protect ecosystems, sustain fish stocks, and reduce conflicts between users of the oceans. But the key question remains: Do MPAs really work? It is the modern incarnation of a longstanding question: How can we best ensure sustainable fisheries? In the 19th century, scientists vigorously debated the effects of fishing on fish populations and ecosystems. A majority of scientists accepted the paradigm that the oceans were unlimited. Thomas Henry Huxley, a pre-eminent Victorian naturalist, famously stated in 1884 that: “... the cod fishery, the herring fishery, the pilchard fishery, the mackerel fishery, and probably all the great sea-fisheries, are inexhaustible; that is to say that nothing we do seriously affects the number of fish ... given our present mode of fishing. And any attempt to regulate these fisheries consequently ... seems to be useless.” The debate culminated in one of the first documented experiments to determine the effects of fishing. In 1886, one bay in Scotland remained open while another was closed to fishing for 10 years. The focus of the experiment was plaice, a valuable commercial fish. Over the decade, plaice in the closed bay increased significantly compared to plaice in the open bay. It was an early, instructive demonstration that fishing does have impacts on fish populations, and that regulation is effective for conservation. Since then, seasonal and longer-term closures have been an important fishery management tool, and they have protected spawning fish and nursery areas, preserved vulnerable habitats, and reduced fishing pressure. But by themselves, MPAs cannot attain all of today’s fishery management objectives. And they can create unintended consequences. Preventing harvesting in some areas, for example, inevitably results in people fishing in other, perhaps more vulnerable, locations. MPAs have now been established throughout the world ocean, from the tropics to the poles. Most are relatively small. Many are neither adequately enforced nor monitored to determine their effectiveness. Of those that have been scientifically monitored, many are in tropical and sub-tropical areas. Fish in these regions live most of their lives in specific habitats, such as reef structures, and don’t stray from them. Their fidelity to a small territory is an important part of the potential success of their marine reserve. Populations do increase in such reserves, and some studies suggest a spillover effect from the reserve that augments fisheries nearby. By contrast, in temperate, boreal, and subarctic systems—where most of the major world fisheries reside—many fish populations are wide-ranging and often exhibit extensive seasonal migrations. Can a reserve by itself be a successful fishery management tool for these fish? In 1994, federal regulations established a number of year-round fishery closures on Georges Bank and adjacent areas. This shallow bank has sustained fisheries of legendary abundance for hundreds of years until the mid-20th century, when the heavily fished stocks declined steeply. The year-round closures evolved from seasonal closures established in the 1970s by the International Commission for Northwest Atlantic Fisheries to protect spawning groundfish, particularly haddock. The current year-round closed areas—on Georges Bank and two nearby areas—encompass more than 20,000 square kilometers. It is one of the largest systems of closed fishing areas now in effect. In addition, a mosaic of seasonally closed areas in the Gulf of Maine eliminates fishing in virtually all parts of the gulf at one time or another. At the same time, the National Oceanic and Atmospheric Administration also restricted the number days at sea that fishermen could fish. Fishing by trawlers declined by more than 40 percent over the next five years, although fishing with static gear, such as lobster traps, gillnets and longlines, and limited scallop harvesting, is still allowed in the closed areas. These closures have given us a unique opportunity to examine a marine protected area in a temperate system under a “macroscope”—to examine how marine ecosystems are structured and how they function and recover. The long history of research on Georges Bank adds a foundation of scientific knowledge that makes the Georges Bank MPA an ideal system to test the effects of year-round fishery closures and adds essential observations to test models. (See “Can We Catch More Fish and Still Preserve the Stocks? ”) We have several ways to assess the Georges Bank and nearby MPAs. We have monitored fish and shellfish populations to get detailed comparisons of abundances and sizes of animals within and outside the closures, both before and after the establishment of the MPAs. Together with information from the commercial fishery and from scientific studies, the results let us see the impacts of the closed areas on seafloor organisms and communities, on the physical structure of the habitat, and on population levels of fish and shellfish species. It is not easy to separate the effects of the closed areas on Georges Bank from other changes, such as fishing-days reductions implemented at the same time. However, our studies show that the closures have played an important role in the overall increase in abundance of these stocks: Despite increases in biomass, MPAs only benefit a fishery if fish eggs and larvae are exported from closed areas to replenish open, harvested areas, and/or if some harvestable-size stock “spills over,” moving from closed to open areas to be caught. But if fish at any age leave closed areas at high rates, it will prevent a buildup within the reserve and cancel out any positive effects from the MPA. Estimating the export of eggs and larvae is extremely difficult. But we can use the location of spawning aggregations and hydrodynamic models to estimate the magnitudes and directions of eggs and larvae dispersal. On Georges Bank, a key factor in larval dispersal is a well-established clockwise circulation pattern, or gyre, resulting from factors including local tidal forces and seafloor topography. The gyre creates a conduit that may allow eggs and larvae to self-seed closed areas, cross-seed other closed areas, and transport larvae to open areas. Our analyses for scallop larvae indicate that the closed areas on Georges Bank can be self-sustaining and also contribute to recruitment into other areas. Our initial findings on spillover amounts show that the MPAs have benefited fisheries for some species, but not all. Using information from the commercial fishing fleet, we found significant spillover for haddock and for yellowtail and winter flounders near some closed areas, but no spillover for other commercially important species. But the commercial fleet clearly expects spillover from the MPAs. Satellite tracking shows that large trawlers concentrate their fishing efforts on the borders of the closed areas, poised to pounce on any fish that strays over the boundaries. Scientists from the Northeast Fisheries Science Center, University of Rhode Island, and the U.S. Geological Survey have documented the impacts of mobile fishing gear, such as bottom trawls and dredges, on bottom-living (benthic) communities of organisms. Comparing detailed photographic images of sites inside and outside the Georges Bank closed areas, they have measured the damage done to the seafloor. The difference is striking: We can see the recovery of benthic organisms inside the closed areas and watch community structure re-emerge, as a result of the MPA. The large-scale management experiment on Georges Bank indicates that a combination of MPAs and other management measures, such as reduced fishing efforts, can allow some species to recover from overexploitation. And beyond protecting fisheries, MPAs potentially offer other benefits. They can: To make the best use of MPAs, though, we have to clearly specify our objectives. We then must evaluate the effectiveness and the social and economic impacts of MPAs and compare the utility of MPAs with other possible management tools to see if they are the best option for the situation. The Georges Bank experience has proven very instructive in how to implement and evaluate marine protected areas in temperate seas—and the experiment is still going strong. FISHING AT THE BORDERSGeorges Bank and surrounding areas with a long history of abundance have seen fish stock depletion and collapse of the fisheries. To speed stock recovery, parts of the area have been closed to fishing as Marine Protected Areas (MPAs), shown as dark blue polygons. Dots indicate fishing effort in 2003, based on satellite tracking of vessels moving at less than 3.5 knots and assumed to be towing fishing gear. Warmer colors (green to red) denote more intense activity. The highest intensity of fishing occurred right at MPA borders, indicating that fishers expected greater abundance there. (Map courtesy of NOAA Fisheries Service) THE DIFFERENCE A DREDGE MAKESThe severe damage done to sea bottom habitats and organisms by dragging fishing gear over the bottom is chronicled in these images. The first photo is a normal seafloor community on Georges Bank, and the second shows a similar area after dredges have been used to harvest scallops. (Photos by Dann Blackwood and courtesy of Dr. Page Valentine, USGS)
Complex carbohydrates are made up of sugar molecules that are strung together in long, complex chains. Complex carbohydrates are found in foods such as peas, beans, whole grains, and vegetables. Both simple and complex carbohydrates are turned to glucose (blood sugar) in the body and are used as energy. Glucose is used in the cells of the body and in the brain. Any unused glucose is stored in the liver and muscles as glycogen for use later. Complex carbohydrate foods provide vitamins, minerals, and fiber that are important to the health of an individual. The majority of carbohydrates should come from complex carbohydrates (starches) and naturally occurring sugars, rather than processed or refined sugars, which do not have the vitamins, minerals, and fiber found in complex and natural carbohydrates. Refined sugars are often called "empty calories" because they have little to no nutritional value. Review Date: 2/9/2016 Reviewed By: Emily Wax, RD, The Brooklyn Hospital Center, Brooklyn, NY. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
At Farnham Green Primary School, we believe that literacy, and communication through speaking and listening are key life skills. Providing both an English curriculum and texts of high quality, we help children develop the skills and knowledge that will enable them to communicate effectively and creatively through spoken and written language and equip them with the skills to become lifelong learners. We want children to enjoy and appreciate literature and its rich variety, therefore lessons will include a number of different techniques such as; drama, role play, painting, Talk for Writing and links to other curriculum areas which will enable the children to gain a better understanding of the high quality texts being studied thus fully appreciate a text and begin to read for pleasure. English is at the heart of all children’s learning. It enables children both to communicate with others effectively for a variety of purposes and to examine their own and others’ experiences, feelings and ideas, giving these order and meaning. Because English is central to children’s intellectual, emotional and social development it has an essential role across the curriculum and helps pupils’ learning to be coherent and progressive. How do we teach reading? Children and staff at Farnham Green are enthusiastic readers and we endeavour to foster a love and passion for reading in our children. The development of reading is the top priority for our children. Teaching reading is the central strategy in developing children’s literacy. They will develop all the key elements of word recognition, decoding, recognising the link between letters and sounds and understanding of meaning and language comprehension. In this school children will be confident readers who read for pleasure. How will this happen? - In Early Years and Key Stage 1, we use a systematic phonics approach called Read Write Inc. to ensure children quickly learn how to decode and read whole words and sentences. - Children in Early Years and Key Stage 1 will also be taught comprehension skills through a daily guided reading lesson. - In Key Stage 2, children are taught reading skills through a daily guided reading lesson and a comprehension lesson once a week. - Pupils will be given opportunities to apply what they have learnt through carefully selected reading texts at an appropriate level. The children are levelled according to the Accelerated Reader Programme which is in place within the school. - All teachers are trained in the principles of phonics, so that they can identify the learning needs of young children and recognise and overcome the barriers that impede learning. - English lessons are centered around high quality texts that encourage deeper philosophical discussion into character’s actions, story settings, plots and author’s voice. - The wider curriculum gives children rich opportunities to talk and listen in a wide range of contexts. This contributes to developing their familiarity with books and stories and their knowledge of the meanings of words. - The assessment of individual pupils’ progress in reading and their phonic knowledge and skills will be frequent and detailed to identify quickly the pupils who are not making good progress so that strategies can be put in place for them to keep up with their peers. - We have high expectations of what all pupils should achieve. - Children are involved in the assessment of their progress and receive regular supportive feedback on their work. - We provide an exciting reading environment that encourages children to read with themed reading areas in all classes, teachers who share their love of reading with children and a vibrant and fabulously well stocked library.
PASADENA, Calif. -- Data from NASA's Cassini mission reveal Saturn's moon Phoebe has more planet-like qualities than previously thought. Scientists had their first close-up look at Phoebe when Cassini began exploring the Saturn system in 2004. Using data from multiple spacecraft instruments and a computer model of the moon's chemistry, geophysics and geology, scientists found Phoebe was a so-called planetesimal, or remnant planetary building block. The findings appear in the April issue of the Journal Icarus. "Unlike primitive bodies such as comets, Phoebe appears to have actively evolved for a time before it stalled out," said Julie Castillo-Rogez, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Objects like Phoebe are thought to have condensed very quickly. Hence, they represent building blocks of planets. They give scientists clues about what conditions were like around the time of the birth of planets and their moons." Cassini images suggest Phoebe originated in the far-off Kuiper Belt, the region of ancient, icy, rocky bodies beyond Neptune's orbit. Data show Phoebe was spherical and hot early in its history, and has denser rock-rich material concentrated near its center. Its average density is about the same as Pluto, another object in the Kuiper Belt. Phoebe likely was captured by Saturn's gravity when it somehow got close to the giant planet. Saturn is surrounded by a cloud of irregular moons that circle the planet in orbits tilted from Saturn's orbit around the sun, the so-called equatorial plane. Phoebe is the largest of these irregular moons and also has the distinction of orbiting backward in relation to the other moons. Saturn's large moons appear to have formed from gas and dust orbiting in the planet's equatorial plane. These moons currently orbit Saturn in that same plane. "By combining Cassini data with modeling techniques previously applied to other solar system bodies, we've been able to go back in time and clarify why it is so different from the rest of the Saturn system," said Jonathan Lunine, a co-author on the study and a Cassini team member at Cornell University, Ithaca, N.Y. Analyses suggest that Phoebe was born within the first 3 million years of the birth of the solar system, which occurred 4.5 billion years ago. The moon may originally have been porous but appears to have collapsed in on itself as it warmed up. Phoebe developed a density 40 percent higher than the average inner Saturnian moon. Objects of Phoebe's size have long been thought to form as "potato-shaped" bodies and remained that way over their lifetimes. If such an object formed early enough in the solar system's history, it could have harbored the kinds of radioactive material that would produce substantial heat over a short timescale. This would warm the interior and reshape the moon. "From the shape seen in Cassini images and modeling the likely cratering history, we were able to see that Phoebe started with a nearly spherical shape, rather than being an irregular shape later smoothed into a sphere by impacts," said co-author Peter Thomas, a Cassini team member at Cornell. Phoebe likely stayed warm for tens of millions of years before freezing up. The study suggests the heat also would have enabled the moon to host liquid water at one time. This could explain the signature of water-rich material on Phoebe's surface previously detected by Cassini. The new study also is consistent with the idea that several hundred million years after Phoebe cooled, the moon drifted toward the inner solar system in a solar-system-wide rearrangement. Phoebe was large enough to survive this turbulence. More than 60 moons are known to orbit Saturn, varying drastically in shape, size, surface age and origin. Scientists using both ground-based observatories and Cassini's cameras continue to search for others. -->The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for the agency's Science Mission Directorate in Washington. The California Institute of Technology in Pasadena manages JPL for NASA. Jia-Rui C. Cook 818-354-0850 Jet Propulsion Laboratory, Pasadena, Calif. Dwayne Brown 202-358-1726 NASA Headquarters, Washington
Estimate Orientation Through Inertial Sensor Fusion This example shows how to use 6-axis and 9-axis fusion algorithms to compute orientation. Sensor Fusion and Tracking Toolbox™ includes several algorithms to compute orientation from inertial measurement units (IMUs) and magnetic-angular rate-gravity (MARG) units. This example covers the basics of orientation and how to use these algorithms. An object's orientation describes its rotation relative to some coordinate system, sometimes called a parent coordinate system, in three-dimensions. Sensor Fusion and Tracking Toolbox uses North-East-Down (NED) as a fixed, parent coordinate system. NED is sometimes referred to as the global coordinate system or reference frame. In the NED reference frame, the X-axis points north, the Y-axis points east, and the Z-axis points downward. The X-Y plane of NED is considered to be the local tangent plane of the Earth. Depending on the algorithm, North may be either Magnetic North or True North. The algorithms in this example use Magnetic North. An object can be thought of as having its own coordinate system, often called the local or child coordinate system. This child coordinate system rotates with the object relative to the parent coordinate system. If there is no translation, the origins of both coordinate systems overlap. The orientation quantity computed in Sensor Fusion and Tracking Toolbox is a rotation that takes quantities from the parent reference frame to the child reference frame. The rotation is represented by a quaternion or rotation matrix. Types of Sensors For orientation estimation, three types of sensors are commonly used: accelerometers, gyroscopes and magnetometers. Accelerometers measure proper acceleration. Gyroscopes measure angular velocity. Magnetometers measure the local magnetic field. Different algorithms are used to fuse different combinations of sensors to estimate orientation. Through most of this example the same set of sensor data is used. Accelerometer, gyroscope and magnetometer sensor data was recorded while a device moved in three different directions: first around its local Y-axis, then around its Z-axis, and finally around its X-axis. The device's X-axis was generally pointed southward for the duration of the experiment. ld = load('rpy_9axis.mat'); acc = ld.sensorData.Acceleration; gyro = ld.sensorData.AngularVelocity; mag = ld.sensorData.MagneticField; viewer = fusiondemo.OrientationViewer; The ecompass function fuses accelerometer and magnetometer data. This is a memoryless algorithm that requires no parameter tuning, but is highly susceptible to sensor noise. qe = ecompass(acc, mag); for ii=1:size(acc,1) viewer(qe(ii)); pause(0.01); end Note that the ecompass algorithm correctly finds the location of north. However, because the function is memoryless the estimated motion is not smooth. It is dramatically affected by the noise in the accelerometer and magnetometer. Some of the techniques presented in the Lowpass Filter Orientation Using Quaternion SLERP could be used to smooth the motion. The imufilter System object fuses accelerometer and gyroscope data using an internal error-state Kalman filter. The filter is capable of removing the gyroscope's bias noise, which drifts over time. ifilt = imufilter('SampleRate', ld.Fs); for ii=1:size(acc,1) qimu = ifilt(acc(ii,:), gyro(ii,:)); viewer(qimu); pause(0.01); end Although the imufilter algorithm produces a significantly smoother estimate of the motion, as compared to the ecompass, it does not correctly estimate the direction of North. The imufilter does not process magnetometer data so it simply assumes the device's X-axis is initially pointing northward. The motion estimate given by imufilter is relative to the initial estimated orientation. An attitude and heading reference system (AHRS) consists of a 9-axis system that uses an accelerometer, gyroscope and magnetometer to compute orientation. The ahrsfilter System object combines the best of the previous algorithms to produce a smoothly changing estimate of the device orientation, while correctly estimating the direction of North. This algorithm also uses an error-state Kalman filter. In addition to gyroscope bias removal, the ahrsfilter has some ability to detect and reject mild magnetic jamming. ifilt = ahrsfilter('SampleRate', ld.Fs); for ii=1:size(acc,1) qahrs = ifilt(acc(ii,:), gyro(ii,:), mag(ii,:)); viewer(qahrs); pause(0.01); end Tuning Filter Parameters Tuning the parameters of the ahrsfilter and imufilter to match specific hardware sensors can improve performance. It is important to also take into account the environment of the sensor. The imufilter parameters are a subset of the ahrsfilter parameters. The AccelerometerNoise, GyroscopeNoise, MagnetometerNoise, and GyroscopeDriftNoise are measurement noises. The sensors' datasheets help determine those values. The LinearAccelerationNoise and LinearAccelerationDecayFactor govern the filter's response to linear (translational) acceleration. Shaking a device is a simple example of adding linear acceleration. Consider how an imufilter with a LinearAccelerationNoise of 9e-3 responds to a shaking trajectory, compared to one with a LinearAccelerationNoise of 9e-4 . ld = load('shakingDevice.mat'); accel = ld.sensorData.Acceleration; gyro = ld.sensorData.AngularVelocity; viewer = fusiondemo.OrientationViewer; highVarFilt = imufilter('SampleRate', ld.Fs, ... 'LinearAccelerationNoise', 0.009); qHighLANoise = highVarFilt(accel, gyro); lowVarFilt = imufilter('SampleRate', ld.Fs, ... 'LinearAccelerationNoise', 0.0009); qLowLANoise = lowVarFilt(accel, gyro); One way to see the effect of the LinearAccelerationNoise is to look at the output gravity vector. The gravity vector is simply the 3rd column of the orientation rotation matrix. rmatHigh = rotmat(qHighLANoise, 'frame'); rmatLow = rotmat(qLowLANoise, 'frame'); gravDistHigh = sqrt(sum( (rmatHigh(:,3,:) - [0;0;1]).^2, 1)); gravDistLow = sqrt(sum( (rmatLow(:,3,:) - [0;0;1]).^2, 1)); figure; plot([squeeze(gravDistHigh), squeeze(gravDistLow)]); title('Euclidean Distance to Gravity'); legend('LinearAccelerationNoise = 0.009', ... 'LinearAccelerationNoise = 0.0009'); The lowVarFilt has a low LinearAccelerationNoise so it expects to be in an environment with low linear acceleration. Therefore, it is more susceptible to linear acceleration, as illustrated by the large variations earlier in the plot. However, because it expects to be in an environment with a low linear acceleration, higher trust is placed in the accelerometer signal. As such, the orientation estimate converges quickly back to vertical once the shaking has ended. The converse is true for highVarFilt. The filter is less affected by shaking but the orientation estimate takes longer to converge to vertical when the shaking has stopped. The MagneticDisturbanceNoise property enables modeling magnetic disturbances (non-geomagnetic noise sources) in much the same way LinearAccelerationNoise models linear acceleration. The two decay factor properties (MagneticDisturbanceDecayFactor and LinearAccelerationDecayFactor) model the rate of variation of the noises. For slowly varying noise sources, set these parameters to a value closer to 1. For quickly varying, uncorrelated noises, set these parameters closer to 0. A lower LinearAccelerationDecayFactor enables the orientation estimate to find "down" more quickly. A lower MagneticDisturbanceDecayFactor enables the orientation estimate to find North more quickly. Very large, short magnetic disturbances are rejected almost entirely by the ahrsfilter. Consider a pulse of [0 250 0] uT applied while recording from a stationary sensor. Ideally, there should be no change in orientation estimate. ld = load('magJamming.mat'); hpulse = ahrsfilter('SampleRate', ld.Fs); len = 1:10000; qpulse = hpulse(ld.sensorData.Acceleration(len,:), ... ld.sensorData.AngularVelocity(len,:), ... ld.sensorData.MagneticField(len,:)); figure; timevec = 0:ld.Fs:(ld.Fs*numel(qpulse) - 1); plot( timevec, eulerd(qpulse, 'ZYX', 'frame') ); title(['Stationary Trajectory Orientation Euler Angles' newline ... 'Magnetic Jamming Response']); legend('Z-rotation', 'Y-rotation', 'X-rotation'); ylabel('Degrees'); xlabel('Seconds'); Note that the filter almost totally rejects this magnetic pulse as interference. Any magnetic field strength greater than four times the ExpectedMagneticFieldStrength is considered a jamming source and the magnetometer signal is ignored for those samples. The algorithms presented here, when properly tuned, enable estimation of orientation and are robust against environmental noise sources. It is important to consider the situations in which the sensors are used and tune the filters accordingly.
Occasional Biting Pests Richard M. Houseman Department of Entomology There are several species of insects and mites that bite human occasionally. Some are encountered indoors while others are found outdoors. Some are specific pests of humans, with no other hosts, while others attack humans incidentally. These insects and mites vary in their biology, behavior and methods of control. Bed bugs and their relatives Bed bug (actual size 6 to 9 millimeters). The common bed bug, Cimex lectularius, belongs to the family Cimicidae (Figure 1). A related species called the tropical bed bug, Cimex hemipterus, occurs in the southern United States but is relatively uncommon in Missouri. Bed bugs are brown, flattened, oval, wingless and 6 to 9 millimeters long when unfed. They possess a piercing-sucking beak through which they imbibe the blood of a host. When engorged with blood, the body becomes swollen and elongated, and the color changes to a dull red. Newly hatched bugs are the same shape as adults but translucent and nearly colorless. Bed bugs hide in cracks and crevices in and around the bed during the day and come out at night to feed on people asleep in the bed. The result of their bite is an itchy, inflamed wheal, or slightly elevated area of skin, at the site of beak insertion. Bed bugs are not known to carry diseases but are undesirable because of their irritating bite. There are several other bugs in the bed bug family that may accidentally become biting pests of humans. Bats are infested with a close relative, the bat bug, Cimex adjunctus. Like the bed bug, bat bugs live away from their host except when feeding. When bats infest a structure and are later excluded, bat bugs leave the bat roosting area in search of a blood meal. If humans are nearby, they can be bitten by bat bugs. Similarly, the swallow bug, Oeiacus vicarious, and the poultry bug, Haematosiphon inodorus, can be found in homes that have birds roosting in the attic or walls. When the birds are removed, swallow bugs may crawl about and bite humans. Thoroughly clean bed coverings, mattresses and pillows. Lightly but thoroughly mist all cracks and crevices in the bed frame, springs, slats and mattress with an aerosol insecticide. Do not treat the entire surface of the mattress; focus on the creases around the edges and buttons. Treat all crevices in the infested area, especially around doors, windows, picture frames, baseboards, etc. Bat bugs or swallow bugs in the attic and wall voids can be treated by a light but thorough application of a suitable insecticide to the infested areas. Pyrethrins and pyrethroids (usually have active ingredients ending in -thrin) that include bed bugs on the label can be used for these treatments. Do not use bedding until it is thoroughly dry. Read and follow all label directions when using these products. Bird and rodent mites Chicken mite (actual size approximately 1 millimeter). Several species of mites are blood-sucking parasites of birds and rodents. Under normal conditions they are confined to their specific hosts. Rats and mice may live in human residences and birds may nest on and in our homes. Problems occur when something happens to remove the normal host. The mites left behind become hungry for a blood meal and start to wander in search of a new host. If a human is the first warm-blooded animal encountered, the mites will bite. The result may be a mild to severe dermatitis at the site where the mites' mouthparts were inserted. Common bird mites involved in this type of "accidental parasitism" include the chicken mite, Dermanyssus gallinae (Figure 2), the northern fowl mite, Ornithonyssus sylviarum, and the tropical fowl mite, Ornithonyssus bursa. Common rodent mites include the tropical rat mite, Ornnithonyssus bacotiand the house mouse mite, Liponyssoides sanguineus.All of these mites are less than 1 mm long and barely visible to the naked eye. Dead carcasses from rodent trapping and baiting should be removed and disposed of daily to avoid the migration of mites to humans. Birds should be denied nesting access to any part of the home. When a nest is built on the outside of the house, it should be removed as soon as it is discovered. Since these mites do not live long without their normal host or reproduce on humans, the problem will eventually be gone — even with no intervention. Biting midge (actual size approximately 1.5 millimeter). Biting midges, also called punkies or no-see-ums, are tiny (about 1.5 mm long) flies of the family Ceratopogonidae (Figure 3). They have piercing-sucking mouthparts and attack almost any warm-blooded animal in search of a blood meal. The bites of most species cause an immediate sharp pain. This is followed by the development of red areas. For most people these lesions last up to a week or more and are more painful than mosquito bites. The larval stage of biting midges is wormlike and develops in standing water, wet soil, or wet organic matter. It takes about a month to complete development from egg to adult. Because of the aquatic or semiaquatic habitat of the larvae, adults are more likely to be a biting problem in areas near wet environments. Most biting activity takes place at twilight. Only the female midge is a blood feeder; the male feeds on plant juices. Effective control is difficult. Whenever possible, eliminate the wet conditions of the larval habitat. Area fogging and spraying offers little control and only brief relief. The best protection is the use of an insect repellent containing the active ingredient diethyl toluamide (DEET). Thrips (actual size 1.5 to 3 millimeters long). Thrips are small (1.5 to 3 mm long) plant-feeding insects of the order Thysanoptera. They have raspingsucking mouthparts and normally feed on the "slush" created by rasping away the surface of a leaf. Some thrips are wingless and are not a biting threat to humans, but many others with narrow, fringed wings have the ability to fly and consequently land on humans (Figure 4). Large numbers of thrips may be flying about when searching for a mate or when their host plant withers and they are searching for another one. If they land on the bare skin of a human, they "rasp" the skin, causing a sudden burning sensation at the bite site. They soon find that human skin is devoid of plant juices and fly away or crawl to a new site to rasp the skin again. In some people, a red wheal may develop with an itching sensation persisting for several days. Thrips do not seek humans as a food source. Their bites are only incidental. Repellents offer no protection. If you must be in an area where thrips are abundant and active, the best protection from bites is to wear a long-sleeved shirt with upturned collar and long pants. Peak thrips activity occurs during bright sunlight. Farm workers are most likely to be bitten, because they are most likely to be around the host plants. Minute pirate bugs Insidious flower bug (actual size 2 to 4 millimeters). Minute pirate bugs are small (2 to 4 mm) predaceous bugs of the family Anthocoridae. They normally feed on other small insects, mites or insect eggs by sucking the body fluids of their prey If they land on human skin, they may decide to bite. The result is a sudden painful sensation. Pirate bugs may continue biting for several seconds unless they are wiped away. This results in an itching, red wheal that can persist for several days. The most common species that bites humans is the insidious flower bug, Orius insidiosus (Figure 5). It has a black body with contrasting, clear white wing tips, which lie flat on the top of the body when at rest. Since their biting of humans is incidental, keeping the skin covered with clothing is the best way to avoid their bites. Warning on the use of chemicals Apply chemicals only where needed or justified. Before using any chemical, please read the label carefully for directions on application procedures, appropriate rate, first aid, storage and disposal. Make sure that the chemical is properly registered for use on the intended pest and follow all other label directions. Keep insecticides in original containers, complete with labels, and keep them out of the reach of children and pets. Do not allow children or pets near treated areas before these areas dry. Carefully and properly dispose of unused portions of diluted sprays and empty insecticide containers.
ELISA: Enzyme-linked immunosorbent assay, a rapid immunochemical test that involves an enzyme used for measuring a wide variety of tests of body fluids. ELISA tests detect substances that have antigenic properties, primarily proteins rather than small molecules and ions, such as glucose and potassium. Some of these substances include hormones, bacterial antigens, and antibodies. ELISA tests are generally highly sensitive and specific, and they compare favorably with radioimmune assay (RIA) tests. They have the added advantage of not requiring the use of radioisotopes or radiation-counting apparatus.
How Blood Carries Oxygen We all know that oxygen is the key to living. It's in the air you breathe, in your lungs and in your blood. What you might not know is how oxygen gets into your blood and how the blood carries oxygen through your body. Blood and Oxygen - How It Works You breathe air in through your nose and mouth. It makes its way into your lungs and dissolves in the water lining of the alveoli. Oxygen then clings to red blood cells as they pass through the alveolar capillaries - now the oxygen is in the blood. Blood and Oxygen - Types of Blood Vessels Three types of blood vessels carry blood from your lungs to every cell in your body. - Arteries - Arteries have muscular walls that pump oxygen-filled blood away from your heart to the tissues and organs, like the brain, kidneys and liver. Arteries get smaller as they get further from your heart. At their smallest point, arteries become capillaries. - Capillaries - Capillaries are the tiniest blood vessels. They connect arteries to veins. - Veins - Veins are what bring the "used" blood back to your heart. Blood and Oxygen - Did U Know? - The only part of your body that has no blood supply is the cornea in the eye. It takes in oxygen directly from the air. - A severe sunburn damages the blood vessels so badly that it takes four to 15 months for them to return to their normal condition. - The human heart creates enough pressure to squirt blood 30 feet (nine meters) out of the body.
Fossil fuels, or conventional fuels, have a big shortfall – resources are limited. These conventional fuels have been formed by the anaerobic decomposition of the remains of organisms including phytoplankton and zooplankton, and this process takes millions of years. In the first stage the materials converted into kerogen, which can be found in oil shales. Subsequently the process produced liquid and gaseous hydrocarbons. This process is called catagenesis, where organic kerogens are broken down into hydrocarbons. Due to this process, a wide range of organic, or hydrocarbon, compounds can be found in any given fuel mixture. The specific mixture of hydrocarbons gives each fuel its characteristic properties, such as boiling points, melting points, density, viscosity et cetera. For instance, fuels like natural gas, contain only very low boiling components. On the other hand, gasoline or diesel contain much higher boiling components. Natural gas was once seen as an un-needed byproduct of petroleum production. However, nowadays natural gas is considered a valuable resource. Heavy crude oil is an important source of fossil fuels, which is much more viscous than conventional crude oil and for instance tar sands, where bitumen are found mixed with sand and clay. Oil shale and similar materials are sedimentary rocks, containing kerogen. This is a complex mixture of high-molecular weight organic compounds, which yield synthetic crude oil when heated. As stated before, resources of these conventional fuels are limited. Also the pollution side-effect of extraction is a big drawback, of which the latest BP-oil rig disaster in the Gulf of Mexico a dramatic example. Research into alternative energy has been intensified over the last years, ranging from solar energy, and energy produced by wind and water. First generation Biofuels (1G) are derived from sugar, vegetable oil or animal fats using conventional technology. Ethanol fuel is the most common Biofuel worldwide, and the most important in Bazil. Through a complex process using wheat, corn, sugar beets and sugar cane, Biofuel can be derived. The problem with this first generation Biofuel is that it competes with food (growing capacity) and forested areas. So farmers who grow soy, wheat or corn for producing Biofuels, cannot use the land for growing food crops. Second generation (2G) Biofuels try to avoid the need to use cultivated areas. The goal of the second generation is to extend the amount of Biofuels which can be produced sustainably. This can be achieved by using biomass consisting of the residual non-food parts of current crops. Second generation Biofuels use biomass to liquid technology including cellulosic Biofuels. 2G Biofuels do have the same limitations as 1G Biofuels: it still needs crops (or crop waste). Producing 1G and 2G Biofuels releases carbon dioxide, which is also a big negative factor. One interesting third generation Biofuel is produced from algae (or algaeoleum). The advantage is that algae can produce up to 300 times more oil per acre than conventional crops, like grape seeds, palms, soybeans. Algae have a harvesting cycle of only one to ten days and it is possible to harvest in a very short time frame. Algae are able to grow 20 to 30 times faster than food crops and can also be grown on land which is not suitable for other established crops. This reduces the problem of taking away pieces of land from the cultivation of food crops. Another big advantage is that production of Biofuel from algae is climate (or CO2) neutral. A big disadvantage is the cost: food grade algae costs approximately $5,000 per tonne. Another interesting 3G Biofuel is that derived from bacteria. The deadly E. coli bacteria might seem like an unlikely ally, but scientists California claim they have successfully genetically manipulated a deadly bug and a host of other bacteria to produce pure hydrocarbon chains that can be processed into Biofuels. In fact, they’re performing so well that they can coax the bacteria into producing a substance that’s exceptionally close to crude oil – minus the sulfur impurities that taint the oil we pump out of the ground. An interesting question could be: are “bug farmers” the next great oil barons? Companies active in Biofuel derived from bacteria are for instance LS9, Aurora Agae, Algenol Biofuels, Amyris Biotechnologies, Bio Architecture Lab, Sapphire Energy, Synthetic Genomics, Targeted Growth and Joule Unlimited. This list of companies is not extensive! In September, the American company Joule Unlimited was granted a US patent for an engineered bacterium (cyanobacteria) which produces liquid hydrocarbon fuels from sunlight and carbon dioxide. Joule Unlimited claims boldly that it can produce diesel fuel directly by only using sunlight and waste carbon dioxide in glass bioreactors for as little as $30 a barrel. To put in perspective: WTI Light Sweet Crude costs about $82.50 per barrel. Although this might be a breakthrough the process of producing Biofuel from bacteria takes a lot of time and effort. Oil has to be extracted from algae and subsequently the output has to be refined into useful Biofuel. In other words, before Biofuel from algae could be commercialized, it might take ten years. Whether or not it might take a lot of time before conventional oil could be replaced, it might be worthwhile, or even necessary, to keep track of this interesting 3G Biofuel development. Wednesday, October 20- 2010 @ 15:07 UAE local time (GMT+4) Replication or redistribution in whole or in part is expressly prohibited without the prior written consent of Mediaquest FZ LLC.
The half-life of potassium-40 is 1.3 billion years, far longer than that of carbon-14, allowing much older samples to be dated.Potassium is common in rocks and minerals, allowing many samples of geochronological or archeological interest to be dated.Argon, a noble gas, is not commonly incorporated into such samples except when produced in situ through radioactive decay. K-Ar dating was used to calibrate the geomagnetic polarity time scale. Thermoluminescence testing also dates items to the last time they were heated. An additional problem with carbon-14 dates from archeological sites is known as the "old wood" problem. It is possible, particularly in dry, desert climates, for organic materials such as from dead trees to remain in their natural state for hundreds of years before people use them as firewood or building materials, after which they become part of the archaeological record. Many factors can spoil the sample before testing as well, exposing the sample to heat or direct light may cause some of the electrons to dissipate, causing the item to date younger.

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