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Evolution of the eye	Stages of evolution	Placement Predators generally have eyes on the front of their heads for better depth perception to focus on prey. Prey animals' eyes tend to be on the side of the head giving a wide field of view to detect predators from any direction. Flatfish are predators which lie on their side on the bottom, and have eyes placed asymmetrically on the same side of the head. A transitional fossil from the common symmetric position to the asymmetric position is Amphistium.
Sugarcane grassy shoot disease	Sugarcane grassy shoot disease	Sugarcane grassy shoot disease (SCGS), is associated with 'Candidatus Phytoplasma sacchari' which are small, pleomorphic, pathogenic mycoplasma that contributes to yield losses from 5% up to 20% in sugarcane. These losses are higher in the ratoon crop. A higher incidence of SCGS has been recorded in some parts of Southeast Asia and India, resulting in 100% loss in cane yield and sugar production.
Sugarcane grassy shoot disease	SCGS disease symptoms	Phytoplasma-infected sugarcane plants show a proliferation of tillers, which give it typical grassy appearance, hence the name grassy shoot disease. The leaves of infected plants do not produce chlorophyll, and therefore appear white or creamy yellow. The leaf veins turn white first as the phytoplasma resides in leaf phloem tissue. Symptoms at the early stage of the plant life cycle include leaf chlorosis, mainly at the central leaf whorl. Infected plants do not have the capacity to produce food in the absence of chlorophyll, which results in no cane formation. These symptoms can be seen prominently in the stubble crop. The eye or lateral buds sprout before the normal time on growing cane. A survey of various fields of western Maharashtra showed grassy shoot with chlorotic or creamy white leaves was the most prevalent phenotype in sugarcane plants infected with SCGS.
Sugarcane grassy shoot disease	Causal organism	SCGS disease is related to 'Candidatus Phytoplasma sacchari, which is one of the most destructive pathogens of sugarcane (Saccharum officinarum L.). In India, SCGS phytoplasmas are spreading at an alarming rate, adversely affecting the yield of the sugarcane crop. Phytoplasmas formerly called mycoplasma-like organisms (MLOs), are a large group of obligate, intracellular, cell wallless parasites classified within the class Mollicutes. Phytoplasmas are associated with plant diseases and are known to cause more than 600 diseases in several hundred plant species, including gramineous weeds and cereals. The symptoms shown by infected plants include: whitening or yellowing of the leaves, shortening of the internodes (leading to stunted growth), smaller leaves and excessive proliferation of shoots, resulting in a broom phenotype and loss of apical dominance .
Sugarcane grassy shoot disease	Transmission	Sugarcane is a vegetatively propagated crop, so the pathogen is transmitted via seed material and by phloem-feeding leafhopper vectors. Saccharosydne saccharivora, Matsumuratettix hiroglyphicus, Deltocephalus vulgaris and Yamatotettix flavovittatus have been confirmed as vectors for phytoplasma transmission in sugarcane. Unconfirmed reports also suggest a spread through the steel blades (machetes) used for sugarcane harvesting.
Sugarcane grassy shoot disease	Detection	Phytoplasma-infected sugarcane can be recognized by visual symptoms, but there are limitations. Visual symptoms occur only after considerable growth, normally two to three weeks after planting. If not observed keenly, confusion may occur on differences between symptoms of SCGS disease and iron deficiency. In addition to above points, the poor relationship between symptoms and phytoplasma presence has been confirmed by earlier findings that symptoms alone are not reliable indicators of infection or identity. This highlights the importance of employing tests, such as molecular tests, to verify associations between phytoplasma and putative disease symptoms. Also, it suggests the inability to recognize symptomless sugarcane harbouring a phytoplasma could result in inadvertent exposure of sugarcane to a potential disease source. Precise diagnosis is, therefore, necessary for effective disease identification and control. Though reliable, DNA hybridization, electron microscopy and PCR techniques require specialized equipment and trained human resources. Among these, polymerase chain reaction (PCR) is an accurate, economical and convenient method, which allows analysis of samples in a short time.
Sugarcane grassy shoot disease	Detection	In recent years, regions of the rRNA operon of the prokaryotic and eukaryotic organisms have been sequenced and are being used to develop PCR-based detection assays. These sequences are highly specific to the infecting organism.
Sugarcane grassy shoot disease	Detection	The ribosomal DNA contains one transcriptional unit with a cluster of genes coding for the 18S, 5.8S and 28S rRNAs and two internal transcribed spacer regions, ITS1 and ITS2 in eukaryotes, and for 16S, 5S and 23S in prokaryotes . Previous studies have demonstrated the complex ITS regions are useful in measuring close genealogical relationships because they exhibit greater interspecies differences than the smaller and larger subunits of rRNA genes. The use of specific probes as selective PCR primers offers an impressive approach for the rapid identification of a large number of phytoplasma isolates.
Sugarcane grassy shoot disease	Control	In SCGS disease, the primary concern is to prevent the disease rather than treat it. Large numbers of phytoplasma-infected seed sets used by the farmers usually cause fast SCGS disease spread. Healthy, certified 'disease-free' sugarcane sets are suggested as planting material. If disease symptoms are visible within two weeks after planting, such plants can be replaced by healthy plants. Uprooted infected sugarcane plants need to disposed of by burning them.
Sugarcane grassy shoot disease	Control	Moist hot air treatment of sets is suggested to control infection before planting. This reduces the percentage of disease incidence, but causes a reduction in the percentage of bud sprouting. Reports that the disease spreads through steel blades used for sugarcane harvesting are unconfirmed, but treating the knives using a disinfectant or by dipping them in boiling water for some time is suggested as a precaution.
Sugarcane grassy shoot disease	Control	Phytoplasma infection also spreads through insect vectors; it is, therefore, important to control them. General field observation reports the ratoon crop has a higher percentage of disease incidence than the initial planted (main) crop. When the disease incidence is more than 20%, it is suggested to discontinue that crop cycle. It is always wise to purchase the certified planting material from authorized seed growers, which assures disease-free planting material.
Sugarcane grassy shoot disease	Sugarcane Iron Deficiency and SCGS Disease	Symptoms of iron deficiency (interveinal chlorosis) are very similar to those of SCGS. It shows creamy leaves, but no chlorosis occurs in leaf veins, and they remain green. In the case of severe iron deficiency, veins may lose chlorophyll in the absence of iron and appear similar to SCGS disease.
Sugarcane grassy shoot disease	Sugarcane Iron Deficiency and SCGS Disease	Iron deficiency is caused by a lack of iron nutrients in the soil; therefore, one may observe several plants showing symptoms of iron deficiency in localized patches in a field. Phytoplasma-infected plants, though, may occur anywhere in the field in a more random distribution. Treatment with 0.1% ferrous sulfate, either by spraying or supplying it through fertilizer cures iron deficiency, but phytoplasma-infected sugarcane does not respond to any treatment. Phytoplasma-infected plants growing in vitro show sensitivity to tetracycline.
Clinical Medicine & Research	Clinical Medicine & Research	Clinical Medicine & Research is an open-access, peer-reviewed, academic journal of clinical medicine published by the Marshfield Clinic Research Foundation. The journal is currently edited by Adedayo A. Onitilo (Marshfield Clinic).
Clinical Medicine & Research	Abstracting and indexing	The journal is abstracted and indexed in the following bibliographic databases:
Cardiac magnetic resonance imaging perfusion	Cardiac magnetic resonance imaging perfusion	Cardiac magnetic resonance imaging perfusion (cardiac MRI perfusion, CMRI perfusion), also known as stress CMR perfusion, is a clinical magnetic resonance imaging test performed on patients with known or suspected coronary artery disease to determine if there are perfusion defects in the myocardium of the left ventricle that are caused by narrowing of one or more of the coronary arteries.
Cardiac magnetic resonance imaging perfusion	Introduction	CMR perfusion is increasingly used in cardiac imaging to test for inducible myocardial ischaemia and has been well validated against other imaging modalities such as invasive angiography or FFR. Several recent large-scale studies have shown non-inferiority or superiority to SPECT imaging. It is becoming increasingly established as a marker of prognosis in patients with coronary artery disease.
Cardiac magnetic resonance imaging perfusion	Indications	There are two main reasons for doing this test: To assess the significance of a stenosis (narrowing) in one or more of the coronary arteries that has been previously identified either by standard coronary angiography or CT coronary angiography. This is often used by cardiologists to determine if a coronary stenosis should be treated either by angioplasty or coronary bypass surgery.
Cardiac magnetic resonance imaging perfusion	Indications	To screen patients who have chest pain and risk factors for coronary artery disease, to assess for ischaemia which may be caused by a narrowing in one of the coronary arteries. This could then (if it shows ischaemia) be further investigated with another imaging modality to directly image the coronary arteries such as invasive coronary angiography.In contrast to the nuclear imaging modalities (PET and SPECT), CMR perfusion does not involve the use of ionising radiation and can therefore be used multiple times without the risk to the patient of exposure to radiation.It is a non-invasive test, is generally regarded as a safe (see below) procedure and is well tolerated by patients (apart from people with claustrophobia)
Cardiac magnetic resonance imaging perfusion	Mechanism	The majority of scans are performed using a stress/rest protocol using adenosine as the stressor which acts to induce ischaemia in the myocardium by the coronary 'steal' phenomenon. Some centers use inotrope dobutamine to stress the heart and the images are interpreted in a similar fashion to dobutamine stress echocardiogram. This article concentrates on adenosine stress scans.
Cardiac magnetic resonance imaging perfusion	Mechanism	Adenosine stress An intravenous infusion of adenosine is given at 140 µg/Kg/min for 3 minutes with continuous heart rate and blood pressure recording to induce hyperaemia (normally seen as a drop in systolic blood pressure of 10mmHg or a rise in heart rate of 10bpm). Following this, an intravenous bolus of 0.05 mmol/kg of a gadolinium chelate (such as gadodoteric acid) is administered via an antecubital fossa vein on the contralateral arm to the adenosine.
Cardiac magnetic resonance imaging perfusion	Mechanism	The scan Typically, 3 short axis slices, each of 10mm thickness, are acquired per cardiac cycle, at the basal, mid papillary and apical levels of the left ventricle. A single shot prospectively gated, balanced TFE sequence is used with a typical resolution of 2.5 x 2.5mm. The patient is then allowed to rest until the haemodynamic effects of the adenosine have stopped (typically 5 minutes). The same scan protocol is then performed at rest.
Cardiac magnetic resonance imaging perfusion	Mechanism	Image analysis The images are stored as video files and are analysed on a dedicated workstation. The majority of clinical scans are analysed qualitatively by visually comparing the stress and rest scans in parallel. In a normal scan, the wash in (1st pass) of gadolinium into the myocardium can be seen as the myocardium turning from black to mid grey uniformly throughout the whole of the left ventricle in both the stress and rest scans. In an abnormal scan an area of the myocardium will turn grey slower than the surrounding tissue as the blood (and hence gadolinium) enters more slowly due to a narrowing of the coronary artery supplying it. This is called a perfusion defect and usually represents myocardial ischaemia. It may be seen on both the rest and stress scans in which case it is called a matched perfusion defect and is probably due to an area or scar from a previous myocardial infarction. If it is only seen on the stress scan it is called an area of inducible perfusion defect (ischaemia). The position in the left ventricle of the perfusion defects are described using the AHA 17 segment model.
Cardiac magnetic resonance imaging perfusion	Limitations	Stress CMR cannot be performed on all patients due to the relative or absolute contraindications listed below, this is a problem, especially in patients who either have a pacemaker or severe renal failure.The acquisition of the images is very sensitive to the rhythm of the heart and scans of patients with atrial fibrillation, bigeminy or trigeminy will sometimes be of low quality and may not be interpretable.Due to the high contrast between the blood pool and the myocardium it is common to get what looks like a thin subendocardial area of ischaemia called the Gibbs artifact, this however, is less common with newer technology allowing higher resolution imaging.In patients who have had a previous myocardial infarction or previous coronary artery bypass surgery, the images may be very difficult to interpret and in such cases, the analysis of the scans is performed with the complement of another imaging modality (such as coronary angiography).
Cardiac magnetic resonance imaging perfusion	Safety	It is a non-invasive test as is generally regarded as safe however, there are some patients for whom this is contraindicated and there are a number of potential complications: Contraindications Contraindications are as follows: Any patient who has a contraindication to MRI scanning, especially those with pacemakers Patients with severe asthma, as Adenosine may provoke an attack Patients with severe renal dysfunction, as the Gadolinium contrast agent poses a very small risk of causing Nephrogenic Systemic Fibrosis (NSF) and is therefore contraindicated when the eGFR is less than 30.
Cardiac magnetic resonance imaging perfusion	Safety	Patients who have heart block on their ECG before the test, as the Adenosine may make this worse.
Cardiac magnetic resonance imaging perfusion	Safety	Patients with severe claustrophobia as the MRI scanner is enclosed Adverse events It is common for the patient to get a number of mild symptoms when they are given the Adenosine infusion, such as feeling hot and sweaty, short of breath, nauseous and noticing that their heart is beating faster. These, if they occur, resolve rapidly (normally within 60 seconds) after the Adensoine infusion has stopped.There are a number of more serious and much less common side effects, including transient heart block, bronchoconstriction and a 1 in 10,000 risk of anaphylaxis caused by the gadolinium contrast agent. These can invariably be successfully treated with no long term side effects.Adenosine infusion is associated with some very rare but very serious side effects, including acute pulmonary oedema and cardiac arrest (occurring in ≈1 in 1000 patients).
Monatomic gas	Monatomic gas	In physics and chemistry, "monatomic" is a combination of the words "mono" and "atomic", and means "single atom". It is usually applied to gases: a monatomic gas is a gas in which atoms are not bound to each other. Examples at standard conditions of temperature and pressure include all the noble gases (helium, neon, argon, krypton, xenon, and radon), though all chemical elements will be monatomic in the gas phase at sufficiently high temperature (or very low pressure). The thermodynamic behavior of a monatomic gas is much simpler when compared to polyatomic gases because it is free of any rotational or vibrational energy.
Monatomic gas	Noble gases	The only chemical elements that are stable single atoms (so they are not molecules) at standard temperature and pressure (STP) are the noble gases. These are helium, neon, argon, krypton, xenon, and radon. Noble gases have a full outer valence shell making them rather non-reactive species. While these elements have been described historically as completely inert, chemical compounds have been synthesized with all but neon and helium.When grouped together with the homonuclear diatomic gases such as nitrogen (N2), the noble gases are called "elemental gases" to distinguish them from molecules that are also chemical compounds.
Monatomic gas	Thermodynamic properties	The only possible motion of an atom in a monatomic gas is translation (electronic excitation is not important at room temperature). Thus by the equipartition theorem, the kinetic energy of a single atom of a monatomic gas at thermodynamic temperature T is given by 32kbT , where kb is Boltzmann's constant. One mole of atoms contains an Avogadro number ( Na ) of atoms, so that the energy of one mole of atoms of a monatomic gas is 32kbTNa=32RT , where R is the gas constant. In an adiabatic process, monatomic gases have an idealised γ-factor (Cp/Cv) of 5/3, as opposed to 7/5 for ideal diatomic gases where rotation (but not vibration at room temperature) also contributes. Also, for ideal monatomic gases:
PD 5500	PD 5500	PD 5500 is a specification for unfired pressure vessels. It specifies requirements for the design, manufacture, inspection and testing of unfired pressure vessels made from carbon, ferritic alloy, and austenitic steels. It also includes material supplements containing requirements for vessels made from aluminium, copper, nickel, titanium and duplex.
PD 5500	PD 5500	PD 5500 is the UK’s national pressure vessels code, although the code is used outside the UK. A new edition of PD5500 is published every three years. An amendment is usually published every year in September.BS5500 was declassified as a full British Standard and reclassified as a 'Publicly Available Specification', which lead to it being renamed to PD5500. PD5500 was withdrawn from the list of British Standards because it was not harmonized with the European Pressure Equipment Directive (2014/68/EU formerly 97/23/EC) . EN 13445 was introduced as the harmonized standard. Harmonized standards carry presumed conformity with the requirements of the Pressure Equipment Directive, whereas other pressure vessel design codes such as PD5500 or ASME must demonstrate conformity against each of the Essential Safety Requirements of the Pressure Equipment Directive before conformity can be declared. PD5500 is currently published as a "Published Document" (PD) by the British Standards Institution.
PD 5500	Brexit	In the UK the Pressure Equipment Safty Regulations 2016 enacted the PED into UK law. Since the UK exited the European Union the PED no longer applies and the Pressure Equipment Safety Regulations 2016 have been amended by the enactment of the UK Product Safety and Metrology Regulations, which update a number of pieces of legislation which required amendments to operate outside of the EU.
PD 5500	Brexit	Under this new legislation Harmonised Standards are now referred to as Designated Standards, but the practice of demonstrating compliance remains largely the same. EN 13445 is recognised as a Designated Standard, while other codes such as PD5500 must still demonstrate conformity against each Essential Safety Requirement.
Funnies (golf)	Funnies (golf)	Funnies are terms used during a game of golf to describe various achievements, both positive and negative. They are different from traditional expressions such a birdie, eagle, etc. in that they do not necessarily refer to strict scores, but to unusual events which may happen in the course of a game. They are constantly being developed and there is some variation in their interpretation and usage throughout the world.
Funnies (golf)	Funnies (golf)	The main use of funnies is to add interest to informal matchplay games as they enable players to win something regardless of the overall outcome of the match. They are frequently associated with gambling, with money, usually small stakes, changing hands depending on which funnies occur.
Funnies (golf)	Types of Funny	The most common funnies and their usual meanings are: Oozlum: If any person on the green in regulation (usually in one on a Par 3) has only one or two putts and so matches or beats par, they win. If more than one person succeeds, the funny goes to the one who was nearest the flag. If not won by anyone, this can be rolled over (i.e. pays out double) to the next Par 3, if this is what the players have agreed, and so on. Also called Ooozler or Oozelem.
Funnies (golf)	Types of Funny	Sandy: This is if you hole out for par (or less) having been in a bunker at some point during the hole. Also seen spelled "Sandie". Ferret: The holing of a ball from off the green for a par or better or, in some alternative versions, when the player's score is still relevant to the outcome of that hole. Holing with a putter may be excluded. Golden Ferret: The holing of a ball directly from a bunker.These are all positive outcomes, resulting in a gain, either financial or simply in pride, for the successful player. A negative funny is: Plonker: If a man's drive fails to reach the ladies' tee, which is typically only a short distance in front of the men's tee.Less common funnies: Positive: Sticky: If you hit the flag from off the green but didn't go in. An optimist would consider this good, a pessimist bad. Chippy: If you chip straight in with the flag out. A Chippy Sticky refers to chipping in with the flag still in the hole. Bonito: When a ball lands in the water but skips out back into play. Believed to be Australian. Also called a Barnes Wallis in the United Kingdom. Bridgee: when you ricochet a ball off a bridge ( over water ) and score one under par ( birdie).Negative: Reverse Oozlum: Same as an Oozlum, but if you take three or more putts instead. Reverse Sandy: Same as a Sandy but if you miss the putt for par.
Funnies (golf)	Similar events	Other occurrences that are used for gambling: Positive: Longest Drive: The longest drive of the group, but it must end up on the fairway. Nearest the Pin: This is won by the player who is nearest the pin with his tee shot on a Par 3, so long as the ball finishes on the green. Birdie: One under par (similarly, Eagle and Albatross). These can be gross or net, depending on the agreement at the start of play. Bye: Once the game is over, a short match (often only one or two holes) can be played to give the loser a chance to regain some pride and possibly be bought a drink in the bar afterwards. Equivalent to a beer match in cricket if the main game finishes very early.
Funnies (golf)	Similar events	Hole in One: In view of how rarely this happens, it should pay out a very large amount; however, the normal result is that the successful player has to buy everyone in the bar a drink when they return to the clubhouse. Much glory but potentially costly.Longest Drive and Nearest the Pin are most usually competed for by all of those taking part on Golf Society or corporate days with prizes for the winners.
Funnies (golf)	Similar events	Negative: Out of Turn: If you go out of turn at the start of a hole."Carry the Can" Funnies: Rather like Atlas, who incorrectly was said to have been left supporting the world on his shoulders when someone passed it to him, there is a category of Funny which passes from one player to another rather than simply being won or lost as you go along. Each time it is passed, the fund is increased by one as in a skins game and the player left holding the funny at the end of the round pays out the amount it has accumulated to each of the other players.
Funnies (golf)	Similar events	Most common: The Camel: Every time any player lands in a bunker, one point is added to the camel fund and this player then "carries" the camel until another player lands in a bunker. There is sometimes a division between the Camel for a fairway bunker and The Cat (or Caterpillar) if referring to a greenside bunker, but most would consider this to be an unnecessary complication.
Funnies (golf)	Similar events	The Snake: Every time any player takes three putts, one point is added to the snake fund and this player then "carries" the snake until another player three putts. In strict company, a four putt can be argued to be two snakes, and so on.Less common: The Fish (or Frog): Equivalent to a Camel but relating to water hazards rather than bunkers.
Funnies (golf)	Similar events	The Squirrel (or Monkey): Hit a tree. Some arguments arise whether the tree is just branches or includes foliage and whether bushes count. If in doubt assume everything counts. If it is thought that the ball must have hit a tree but all were unsighted and no sound was heard then the benefit of the doubt rests with the player.
Funnies (golf)	Similar events	The Gorilla (or Bear): If you hit your ball out of bounds.
Funnies (golf)	Miscellaneous	Sally Gunnell: This refers to a shot which is not classically attractive, but which still goes quite a long way because it runs very well. It affectionately refers to the successful British athlete of the early 1990s. Sister-in-law: This refers to a shot that finishes in a far better position than it should have. For example, a Sally Gunnell that ends up a few feet from the hole could be called a Sister-in-law. (In other words, you're up there, but you really shouldn't be.)
SATRO-ECG	SATRO-ECG	SATRO-EKG - a computer program analysing electro-cardiology signals. It is based on the SFHAM model. It facilitates the evaluation of electrical activity of myocardium, and therefore, early detection of ischemic changes in the heart.
SATRO-ECG	Reference tests	The reference tests of the SATRO-ECG method in relation to perfusive scintigraphy SPECT conducted in Military Medical Institute in Warsaw and Medical University of Wroclaw proved the possibility to use this method to detect coronary heart disease (CHD). A very high Sensitivity and specificity in detecting this disease were obtained.Sensitivity (Se), specificity (Sp), predictive value of positive values results (PV(+)) and negative values results (PV(-)) are presented in the grid below: Comparison of SATRO-ECG results - SPECT (exercise) for particular parts of the cardiac muscle is presented in the grid below: where: IS - interventricular septum, AW - anterior wall, IW - inferior wall, LW - lateral wall.The results of the tests prove a high correlation the between SATRO-ECG results and SPECT in the case of detection of coronary heart disease (CHD)
SATRO-ECG	Usage	An advantage of this method is a fast and precise analysis of the ECG results in the rest, which enables: easy and safe measurement detection of ischemic heart disease with very high diagnostic sensitivity and specificity early prevention of the coronary disease, objective and not only statistical risk validation monitoring of the effects of the treatment and early classifying patients to reference tests, e.g. PTCA, SPECT, etc.
SATRO-ECG	Usage	analysing the efficiency of particular biologically active substances (pharmacology, nutriceutics, dietary supplements) and other methods (e.g. physical medicine)The method is a diagnostic element of the Program of Universal Prevention and Therapy of Ischemic Heart Disease in the international project developed for United Nations Economic and Social Council .
Calcite rafts	Calcite rafts	Calcite crystals form on the surface of quiescent bodies of water, even when the bulk water is not supersaturated with respect to calcium carbonate. The crystals grow, attach to one other and appear to be floating rafts of a white, opaque material. The floating materials have been referred to as calcite rafts or "leopard spots".
Calcite rafts	Chemistry	Calcium carbonate is known to precipitate as calcite crystals in water supersaturated with calcium and carbonate ions. Under quiescent conditions, calcite crystals can form on a water surface when calcium carbonate supersaturation conditions do not exist in the bulk water. Water evaporates from the surface and carbon dioxide degasses from the surface layer to create a thin layer of water with high pH and concentrations of calcium and carbonate ions far above the saturation concentration for calcium carbonate. Calcite crystals precipitate in this highly localized environment and attach to one another to form what appear to be rafts of a white material.Scanning electron micrographs of calcite rafts show interconnected calcite crystals formed around holes on the raft surface. The holes may be caused by air bubbles or other foreign matter on the water surface. Micrographs of calcite rafts show lace-like structure. The surface tension of the water keeps the interconnected calcite crystals, which individually have a specific gravity of 2.7, floating on the water surface.
Calcite rafts	Cave and river system formation	Calcite rafts are most commonly formed in limestone cave systems. Limestone caves provide a favorable environment due to little air movement and water containing significant concentrations of calcium and carbonate ions. Evidence of calcite rafts has been found in limestone caves all over the world.One example of calcite raft formation in a spring-fed river system has been reported.
Calcite rafts	Drinking water reservoir	In 2005, the Carpinteria Valley Water District in Carpinteria, California, raised water quality concerns when "leopard spots" approximately 5 to 10 cm. in diameter appeared on the water surface under a newly constructed aluminum reservoir cover. The floating material had not been observed when the reservoir (13 million gallons) was open to the atmosphere. The concern raised was that a potentially toxic metallic precipitate was forming on the water surface from condensate dripping from the metal cover.Water analyses found that the water in the reservoir was saturated with respect to calcium carbonate but no calcite crystals were formed in the bulk solution. X-ray diffraction analysis showed that the floating solid material was greater than 97 percent calcite. Scanning electron micrographs confirmed that the shape of the crystalline material was rhombohedral, which is consistent with calcite crystal formation.While the floating material was not toxic, it was recommended that movement of the water surface be induced so that quiescent conditions would be avoided which would eliminate the primary condition for calcite raft formation.
Calcite rafts	Concrete leachate drops	Micro calcite rafts have been observed on (soda) straw stalactites solution drops suspended beneath concrete structures. These secondary deposits which form outside the cave environment, are known as calthemites. They are derived from concrete, lime or mortar, and mimic the shapes and forms of speleothems created in caves.The micro rafts which form on the surface of hyperalkaline leachate solution drips are typically about 0.5 mm in size when visible to the naked eye, and appear on the drip's surface after it has been suspended for greater than ≈5 minutes. The chemical reaction which creates the rafts, involves carbon dioxide (CO2) being absorbed (diffusing) into solution from the atmosphere and calcium carbonate (CaCO3) precipitates as rafts or deposited as a stalagmite, stalactite or flowstone. This chemistry is very different to that which creates speleothems in caves.
Calcite rafts	Concrete leachate drops	Internal water pulses from the straw (into the drop) and air movement around the suspended solution drop, can cause the rafts to spin swiftly around the drop surface. If there is almost no air movement around the suspended drop, then after approximately 12 minutes or more, the micro rafts may join up and form a latticework, which covers the entire drop surface. If the solution drop hangs too long on the straw (≈ >30 minutes), it may completely calcify over and block the calthemite straw tip.
Alina (malware)	Alina (malware)	Alina is a Point of Sale Malware or POS RAM Scraper that is used by cybercriminals to scrape credit card and debit card information from the point of sale system. It first started to scrape information in late 2012. It resembles JackPOS Malware.
Alina (malware)	Process of Alina POS RAM Scraper	Once executed, it gets installed on the user's computer and checks for updates. If an update is found, it removes the existing Alina code and installs the latest version. Then, for new installations, it adds the file path to an AutoStart runkey to maintain persistence. Finally, it adds java.exe to the %APPDATA% directory and executes it using the parameter alina=<path_to_executable> for new installations or, update=<orig_exe>;<new_exe> for upgrades.Alina inspects the user's processes with the help of Windows API calls: CreateToolhelp32Snapshot() takes a snapshot of all running processes Process32First()/Process32Next() retrieve the track 1 and track 2 information in the process memoryAlina maintains a blacklist of processes, if there is no process information in the blacklist it uses OpenProcess() to read and process the contents in the memory dump. Once the data is scraped Alina sends it to C&C servers using an HTTP POST command that is hardcoded in binary.
FBXL3	FBXL3	FBXL3 is a gene in humans and mice that encodes the F-box/LRR-repeat protein 3 (FBXL3).
FBXL3	FBXL3	FBXL3 is a member of the F-box protein family, which constitutes one of the four subunits in the SCF ubiquitin ligase complex.The FBXL3 protein participates in the negative feedback loop responsible for generating molecular circadian rhythms in mammals by binding to the CRY1 and CRY2 proteins to facilitate their polyubiquitination by the SCF complex and their subsequent degradation by the proteasome.
FBXL3	Discovery	The Fbxl3 gene function was independently identified in 2007 by three groups, led by Michele Pagano, Joseph S. Takahashi, Dr. Patrick Nolan and Michael Hastings, respectively. Takahashi used forward genetics N-ethyl-N-nitrosourea (ENU) mutagenesis to screen for mice with varied circadian activity which led to the discovery of the Overtime (Ovtm) mutant of the Fbxl3 gene. Nolan discovered the Fbxl3 mutation After hours (Afh) by a forward screen assessing wheel activity behavior of mutagenized mice. The phenotypes identified in mice were mechanistically explained by Pagano who discovered that the FBXL3 protein is necessary for the reactivation of the CLOCK and BMAL1 protein heterodimer by inducing the degradation of CRY proteins.
FBXL3	Discovery	Overtime Mice with the homozygous mutation of Ovtm, free run with an intrinsic period of 26 hours. Overtime is a loss of function mutation caused by a substitution of isoleucine to threonine in the region of FBXL3 that binds to CRY. In mice with this mutation, levels of the proteins PER1 and PER2 are decreased, while levels of CRY proteins do not differ from those of wild type mice. The stabilization of CRY protein levels leads to continued repression of Per1 and Per2 transcription and translation.
FBXL3	Discovery	After-hours The After-hours mutation is a substitution of cysteine to serine at position 358. Similar to Overtime, the mutation occurs in the region where FBXL3 binds to CRY. Mice homozygous for the Afh mutation have a free running period of about 27 hours. The Afh mutation delays the rate of CRY protein degradation, therefore affecting the transcription of PER2 protein.
FBXL3	Discovery	Fbxl21 The closest homologue to Fbxl3 is Fbxl21 as it also binds to the CRY1 and CRY2 proteins. Predominantly localized to the cytosol, Fbxl21 has been proposed to antagonize the action of Fbxl3 through ubiquitination and stabilization of CRY proteins instead of leading it to degradation. FBXL21 is expressed predominantly in the suprachiasmatic nucleus, which is the region in the brain that functions as the master pacemaker in mammals.
FBXL3	Characteristics	The human FBXL3 gene is located on the long arm of chromosome 13 at position 22.3. The protein is composed of 428 amino acids and has a mass of 48,707 Daltons. The FBXL3 protein contains an F-box domain, characterized by a 40 amino acid motif that mediates protein-protein interactions, and several tandem leucine-rich repeats used for substrate recognition. It has eight post-translational modification sites involving ubiquitination and four sites involving phosphorylation. The FBXL3 protein is predominantly localized to the nucleus. It is one of four subunits of a ubiquitin ligase complex called SKP1-CUL1-F-box-protein, which includes the proteins CUL1, SKP1, and RBX1.
FBXL3	Function	The FBXL3 protein plays a role in the negative feedback loop of the mammalian molecular circadian rhythm. The PER and CRY proteins inhibit the transcription factors CLOCK and BMAL1. The degradation of PER and CRY prevent the inhibition of the CLOCK and BMAL1 protein heterodimer. In the nucleus, the FBXL3 protein targets CRY1 and CRY2 for polyubiquitination, which triggers the degradation of the proteins by the proteasome. FBXL3 binds to CRY2 by occupying its flavin adenine dinucleotide (FAD) cofactor pocket with a C-terminal tail and buries the PER-binding interface on the CRY2 protein.The FBXL3 protein is also involved in a related feedback loop that regulates the transcription of the Bmal1 gene. Bmal1 expression is regulated by the binding of REV-ERBα and RORα proteins to retinoic acid-related orphan receptor response elements (ROREs) in the Bmal1 promoter region. The binding of the REV-ERBα protein to the promoter represses expression, while RORα binding activates expression. FBXL3 decreases the repression of Bmal1 transcription by inactivating the REV-ERBα and HDAC3 repressor complex.The FBXL3 protein has also been found to cooperatively degrade c-MYC when bound to CRY2. The c-MYC protein is a transcription factor important in regulating cell proliferation. The CRY2 protein can function as a co-factor for the FBXL3 ligase complex and interacts with phosphorylated c-MYC. This interaction promotes the ubiquitination and degradation of the c-MYC protein.
FBXL3	Interactions	FBXL3 has been shown to interact with: SKP1A CRY1 CRY2 REV-ERBα HDAC3 c-MYC
Institut de Chimie des Substances Naturelles	Institut de Chimie des Substances Naturelles	The Institut de Chimie des Substances Naturelles ("Institute for the chemistry of natural substances"), or ICSN, is part of the Centre national de la recherche scientifique, France's most prominent public research organization. Located at Gif-sur-Yvette, near Paris, ICSN is France's largest state-run chemistry research institute. Built in 1959, it employs over 300 people and focuses on four research areas: Synthetic and methodological approaches in Organic Chemistry Natural products and medicinal chemistry Structural chemistry and structural biology Chemistry and biology of therapeutic targets
Japanese Federation of Synthetic Chemistry Workers' Unions	Japanese Federation of Synthetic Chemistry Workers' Unions	The Japanese Federation of Synthetic Chemistry Workers' Unions (Japanese: 合成化学産業労働組合連合, Gokaroren) was a trade union representing workers in the chemical industry in Japan.
Japanese Federation of Synthetic Chemistry Workers' Unions	Japanese Federation of Synthetic Chemistry Workers' Unions	The union was founded in 1950, with the merger of two unions representing ammonium sulfate and phosphate workers. The same year, it was a founding affiliate of the General Council of Trade Unions of Japan (Sohyo). From 1953 until 1957, it was chaired by Ōta Kaoru. By 1967, it had 121,324 members.The union was affiliated with the Japanese Trade Union Confederation from the late 1980s, and by 1996, it had 91,242 members. The All Japan Chemistry Workers' Union split away in 1987, but merged with Goka Roren in 1998 to form the Japanese Federation of Chemistry Workers' Unions.
Biaugmented truncated cube	Biaugmented truncated cube	In geometry, the biaugmented truncated cube is one of the Johnson solids (J67). As its name suggests, it is created by attaching two square cupolas (J4) onto two parallel octagonal faces of a truncated cube. A Johnson solid is one of 92 strictly convex polyhedra that is composed of regular polygon faces but are not uniform polyhedra (that is, they are not Platonic solids, Archimedean solids, prisms, or antiprisms). They were named by Norman Johnson, who first listed these polyhedra in 1966.
Invizimals (video game)	Invizimals (video game)	Invizimals is a PlayStation Portable augmented reality collectible creature video game developed by Novarama, and published by Sony Computer Entertainment Europe. It is the first entry in the Invizimals series, and was bundled with the PSP's camera attachment at launch.
Invizimals (video game)	Gameplay	The gameplay of Invizimals has been compared to the Pokémon series, involving players capturing and raising different species of creatures, and allowing the player to battle with them, either against an AI or with others using the PSP's wireless abilities. Unlike Pokémon however, Invizimals requires the player to hunt and capture these creatures within the real world, using the concept of augmented reality, a camera attachment for the PlayStation Portable, and a physical "trap" square-shaped device used as a fiduciary marker. These monsters are spawned at different environments (determined by colors of surfaces and time of day), and the trap is used to capture the monsters. Once captured, players are able to raise and level their monsters, and allow them to learn different attacks that can be used in battle. Players can also use the trap to view their monsters, and take pictures of their collection.
Invizimals (video game)	Story	The story follows Kenichi Nakamura, a researcher at PSP R&D in Tokyo. He has made the discovery of invisible animals, which he dubs Invizimals. Invizimals are only visible using an attached PSP camera and pointing it at a device called the trap. Kenichi's life is devoted to finding Invizimals, in addition to furthering the common understanding surrounding them. Only specific people have the aura necessary to see these Invizimals, even among those with access to the same equipment, and Kenichi detects that the player is one of these select few people.
Invizimals (video game)	Story	Kenichi's most trusted colleague, Professor Bob Dawson, teaches the player the basics of Invizimal combat and assists Kenichi in his research. Dawson makes the discovery that Invizimals are made of energy, specifically light, and that the light particles that emit off of them in battle - sparks, as Dawson calls them - can be used as a currency in the Invizimal world. After being taught the basics of Invizimal combat, the player hones their skills and trains their Invizimals across various Invizimal fighting clubs spotted across the world.
Invizimals (video game)	Story	Kenichi's boss requests that he take a business trip to a business associate of his located in Mumbai, India, and that Kenichi takes vital research data about Invizimals with him. However, after Kenichi disembarks the plane and leaves the airport, he is kidnapped by an unknown man. Kenichi's good friend Jazmin Nayar notifies the player that she could not find Kenichi around the time he was scheduled to meet up with her. The unknown man interrogated Kenichi, as the unknown man had knowledge of Invizimals. However, Kenichi played dumb in the interrogation, and hid the crucial thumb drive with his research data on it, and was eventually let go. After this incident, Kenichi's boss reached an arrangement with another associate of his, Sir Sebastian Campbell, to have Kenichi transferred to the Campbell Castle in England to give Kenichi a safe place to further conduct his research. After having met Campbell, the player is invited to a tournament in Berlin where many of Campbell's colleagues are attending. After winning the tournament, the player sits down to have dinner with Rolf, the champion of the Berlin club that the player defeated in the tournament. Rolf asks the player to find his favorite Invizimal for him, and in return, Rolf gives the player a mutant Invizimal, an Invizimal with a different color than normal that is more powerful than its regular counterparts.
Invizimals (video game)	Story	Kenichi and Jazmin continue their research in the lower levels of the Campbell Castle, conducting experiments. Kenichi comes to the conclusion that Invizimals can be used as a source of electricity, and is conducting experiments to see how to adequately make use of this. However, in one of his experiments, Kenichi causes the castle's power grid to go out. During the blackout, Kenichi and Jazmin are attacked in a kidnapping plot; Kenichi is successfully kidnapped, but Jazmin managed to escape, sustaining a serious arm injury in the process, and was quickly transferred to Windsor Hospital to rest and heal up. After this happened, Dawson's library was vandalized, destroying many pieces of Dawson's Invizimal research data.
Invizimals (video game)	Story	While the player continues research, Campbell notifies the player of a criminal that he suspects engineered the kidnapping plot: Axel Kaminsky, a Russian arms dealer and international terrorist with extensive knowledge of Invizimals. After awhile, the player gets in contact with Kaminsky, who confirms that he has kidnapped Kenichi. After paying a ransom of sparks, the player is allowed into Kaminsky's secret lair, the Viper's Nest, an underground tunnel in Russia where he is keeping Kenichi hostage. After a brief introduction, Dawson and Jazmin manage to hijack Kaminsky's signal temporarily to warn the player of Kaminsky, as he is secretly an incredibly powerful Invizimal battler that has never been defeated. After Kaminsky regains the signal, he challenges the player to a battle.
Invizimals (video game)	Story	After the player wins and defeats Kaminsky, Kenichi is freed. Before they can escape the Viper's Nest, Campbell and his security storm the Viper's Nest, where it is revealed that Campbell was the one after the Invizimals all along. Campbell hired Kaminsky personally to carry out his work in attempting to steal all Invizimal knowledge in the world for himself. After revealing his true intentions, Campbell challenges the player to a final showdown, which Campbell loses. After having lost the battle, Kenichi and Campbell enter a brief struggle, during which, Kenichi's damaged PSP system begins to glow brilliantly. With Campbell holding Kenichi's PSP in his hand, a large energy explosion is generated, and Campbell is gone, presumably vaporized by the blast. Kenichi and the player leave the Viper's Nest relatively unscathed.
Invizimals (video game)	Scope	The player will be able to collect 100+ invizimals during the course of the game. Each Invizimal has different attacks, powers, and skills. The player can level up their Invizimals by collecting "Watts". The higher the level, the stronger the Invizimal. The Invizimal world has 6 different elements: Fire, Water, Earth (rock), Forest (jungle), Ice and Desert. Just like Pokémon, each element has different strengths and weaknesses the player needs to discover. Finally, the player needs to collect sparks, orb-like items that can be used to purchase power-ups in game stores.
Invizimals (video game)	Elementals	Elementals are based on the Elements of Invizimals. Fire, Ice, Rock, Ocean, Desert and Jungle. These are some of the most powerful vectors in the game (Meteor Strike is the strongest). Elementals must be used wisely, as they cost 50 sparks each. Here is what they look like and what they do: Fire: A giant fire ghost comes out of the ground and slaps the opponent, works best with Jungle types. Ice: A flying eagle-like spirit jumps out of the trap and dives into the enemy, works best with Fire types. Rock: A giant rock monster climbs out of the ground and punches the opponent, works best with Ice types. Ocean: A giant water-creature lunges down and squishes Invizimals with its belly, works best with Rock types. Desert: A giant sand ghost comes out of the trap and turns into a cyclone making other Invizimals lose health, works best with Ocean types. Jungle: A tree comes out fully grown from an acorn, bites the enemy and transforms back into an acorn, works best with Desert types.
Invizimals (video game)	Elementals	Mutant: Mutated Invizimals which are stronger and harder to find.Throughout the game, the player has to capture Invizimals to move on to the next mission. Each Invizimal has its own attacks which only they can use. Each attack has its own property (see Scope section). Also, each Invizimal has to be captured in a different way, even though some are the same. This can range from flying the Invizimal through a storm, or just scaring it out of its skin. Plus, while the player is "powering" the trap, the player can find really rare Mutant Invizimals. These can come in different colours and skills compared to their ordinary Invizimal counterparts.
Invizimals (video game)	Secret Invizimals	This game also includes a lot of "secret Invizimals" which have to be captured by playing on ad-hoc or infrastructure. There are also some Invizimals that can be captured with secret traps only. This can be Invizimals like Tigershark, Venonweb or Moby. These secret Invizimals can be found on the internet on sites like: secretinvizimals.com but there are others too.
Invizimals (video game)	Awards and reception	Invizimals received "average" reviews according to the review aggregation website Metacritic.The game received numerous awards, among which are: Special Achievement for Innovation, IGN Best of E3 2009, winner. Special Achievement for Technological Excellence, IGN Best of E3 2009, winner. Game of the Show, IGN Best of E3 2009, runner-up, lost to LittleBigPlanet. Best New Gameplay Mechanic, Kotaku Best of E3 2009, runner-up, lost to Scribblenauts. Best PSP Game, Kotaku Best of E3 2010, runner-up, lost to God of War: Ghost of Sparta. Ciutat de Barcelona Award 2009 in the category of Technical Innovation, awarded from the city's Mayor Office to individuals and companies with outstanding contributions to the culture of the city of Barcelona. El Duende cultural magazine award. Category: Technology and Video games. Spanish National Videogame Awards 2010. Best Technology. Spanish National Videogame Awards 2010. Best Overall Game.
Negative temperature	Negative temperature	Certain systems can achieve negative thermodynamic temperature; that is, their temperature can be expressed as a negative quantity on the Kelvin or Rankine scales. This should be distinguished from temperatures expressed as negative numbers on non-thermodynamic Celsius or Fahrenheit scales, which are nevertheless higher than absolute zero. The absolute temperature (Kelvin) scale can be understood loosely as a measure of average kinetic energy. Usually, system temperatures are positive. However, in particular isolated systems, the temperature defined in terms of Boltzmann's entropy can become negative. The possibility of negative temperatures was first predicted by Lars Onsager in 1949.
Negative temperature	Negative temperature	Onsager was investigating 2D vortices confined within a finite area, and realized that since their positions are not independent degrees of freedom from their momenta, the resulting phase space must also be bounded by the finite area. Bounded phase space is the essential property that allows for negative temperatures, and can occur in both classical and quantum systems. As shown by Onsager, a system with bounded phase space necessarily has a peak in the entropy as energy is increased. For energies exceeding the value where the peak occurs, the entropy decreases as energy increases, and high-energy states necessarily have negative Boltzmann temperature.
Negative temperature	Negative temperature	A system with a truly negative temperature on the Kelvin scale is hotter than any system with a positive temperature. If a negative-temperature system and a positive-temperature system come in contact, heat will flow from the negative- to the positive-temperature system. A standard example of such a system is population inversion in laser physics.
Negative temperature	Negative temperature	Temperature is loosely interpreted as the average kinetic energy of the system's particles. The existence of negative temperature, let alone negative temperature representing "hotter" systems than positive temperature, would seem paradoxical in this interpretation. The paradox is resolved by considering the more rigorous definition of thermodynamic temperature as the tradeoff between internal energy and entropy contained in the system, with "coldness", the reciprocal of temperature, being the more fundamental quantity. Systems with a positive temperature will increase in entropy as one adds energy to the system, while systems with a negative temperature will decrease in entropy as one adds energy to the system.Thermodynamic systems with unbounded phase space cannot achieve negative temperatures: adding heat always increases their entropy. The possibility of a decrease in entropy as energy increases requires the system to "saturate" in entropy. This is only possible if the number of high energy states is limited. For a system of ordinary (quantum or classical) particles such as atoms or dust, the number of high energy states is unlimited (particle momenta can in principle be increased indefinitely). Some systems, however (see the examples below), have a maximum amount of energy that they can hold, and as they approach that maximum energy their entropy actually begins to decrease. The limited range of states accessible to a system with negative temperature means that negative temperature is associated with emergent ordering of the system at high energies. For example in Onsager's point-vortex analysis negative temperature is associated with the emergence of large-scale clusters of vortices. This spontaneous ordering in equilibrium statistical mechanics goes against common physical intuition that increased energy leads to increased disorder.
Negative temperature	Definition of temperature	The definition of thermodynamic temperature T is a function of the change in the system's entropy S under reversible heat transfer Qrev: T=dQrevdS. Entropy being a state function, the integral of dS over any cyclical process is zero. For a system in which the entropy is purely a function of the system's energy E, the temperature can be defined as: T=(dSdE)−1. Equivalently, thermodynamic beta, or "coldness", is defined as β=1kT=1kdSdE, where k is the Boltzmann constant.
Negative temperature	Definition of temperature	Note that in classical thermodynamics, S is defined in terms of temperature. This is reversed here, S is the statistical entropy, a function of the possible microstates of the system, and temperature conveys information on the distribution of energy levels among the possible microstates. For systems with many degrees of freedom, the statistical and thermodynamic definitions of entropy are generally consistent with each other.
Negative temperature	Definition of temperature	Some theorists have proposed using an alternative definition of entropy as a way to resolve perceived inconsistencies between statistical and thermodynamic entropy for small systems and systems where the number of states decreases with energy, and the temperatures derived from these entropies are different. It has been argued that the new definition would create other inconsistencies; its proponents have argued that this is only apparent.
Negative temperature	Heat and molecular energy distribution	Negative temperatures can only exist in a system where there are a limited number of energy states (see below). As the temperature is increased on such a system, particles move into higher and higher energy states, and as the temperature increases, the number of particles in the lower energy states and in the higher energy states approaches equality. (This is a consequence of the definition of temperature in statistical mechanics for systems with limited states.) By injecting energy into these systems in the right fashion, it is possible to create a system in which there are more particles in the higher energy states than in the lower ones. The system can then be characterised as having a negative temperature.
Negative temperature	Heat and molecular energy distribution	A substance with a negative temperature is not colder than absolute zero, but rather it is hotter than infinite temperature. As Kittel and Kroemer (p. 462) put it, The temperature scale from cold to hot runs: The corresponding inverse temperature scale, for the quantity β = 1/kT (where k is the Boltzmann constant), runs continuously from low energy to high as +∞, …, 0, …, −∞. Because it avoids the abrupt jump from +∞ to −∞, β is considered more natural than T. Although a system can have multiple negative temperature regions and thus have −∞ to +∞ discontinuities.
Negative temperature	Heat and molecular energy distribution	In many familiar physical systems, temperature is associated to the kinetic energy of atoms. Since there is no upper bound on the momentum of an atom, there is no upper bound to the number of energy states available when more energy is added, and therefore no way to get to a negative temperature. However, in statistical mechanics, temperature can correspond to other degrees of freedom than just kinetic energy (see below).
Negative temperature	Temperature and disorder	The distribution of energy among the various translational, vibrational, rotational, electronic, and nuclear modes of a system determines the macroscopic temperature. In a "normal" system, thermal energy is constantly being exchanged between the various modes.
Negative temperature	Temperature and disorder	However, in some situations, it is possible to isolate one or more of the modes. In practice, the isolated modes still exchange energy with the other modes, but the time scale of this exchange is much slower than for the exchanges within the isolated mode. One example is the case of nuclear spins in a strong external magnetic field. In this case, energy flows fairly rapidly among the spin states of interacting atoms, but energy transfer between the nuclear spins and other modes is relatively slow. Since the energy flow is predominantly within the spin system, it makes sense to think of a spin temperature that is distinct from the temperature associated to other modes.
Negative temperature	Temperature and disorder	A definition of temperature can be based on the relationship: T=dqrevdS The relationship suggests that a positive temperature corresponds to the condition where entropy, S, increases as thermal energy, qrev, is added to the system. This is the "normal" condition in the macroscopic world, and is always the case for the translational, vibrational, rotational, and non-spin-related electronic and nuclear modes. The reason for this is that there are an infinite number of these types of modes, and adding more heat to the system increases the number of modes that are energetically accessible, and thus increases the entropy.
Negative temperature	Examples	Noninteracting two-level particles The simplest example, albeit a rather nonphysical one, is to consider a system of N particles, each of which can take an energy of either +ε or −ε but are otherwise noninteracting. This can be understood as a limit of the Ising model in which the interaction term becomes negligible. The total energy of the system is E=ε∑i=1Nσi=εj where σi is the sign of the ith particle and j is the number of particles with positive energy minus the number of particles with negative energy. From elementary combinatorics, the total number of microstates with this amount of energy is a binomial coefficient: ΩE=(NN+j2)=N!(N+j2)!(N−j2)!.
Negative temperature	Examples	By the fundamental assumption of statistical mechanics, the entropy of this microcanonical ensemble is ln ⁡ΩE We can solve for thermodynamic beta (β = 1/kBT) by considering it as a central difference without taking the continuum limit: ln ln ln ln ⁡(N−j+1N+j+1). hence the temperature ln ⁡((N+1)ε−E(N+1)ε+E)]−1.
Negative temperature	Examples	This entire proof assumes the microcanonical ensemble with energy fixed and temperature being the emergent property. In the canonical ensemble, the temperature is fixed and energy is the emergent property. This leads to (ε refers to microstates): ln ⁡(Z)+ET Following the previous example, we choose a state with two levels and two particles. This leads to microstates ε1 = 0, ε2 = 1, ε3 = 1, and ε4 = 2.

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