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Se-tenant (philately)	United States stamps	The US has since printed as many as 50 different stamps on a single sheet, such as in the 50 state flags, birds and flowers. Se-tenant stamps began as issues of separate designs that were simply attached to one another, but have developed to issues where the stamps are part of a larger continuous design.
Feltrim Formation	Feltrim Formation	The Feltrim Formation is a geologic formation in Ireland. It preserves fossils dating back to the Carboniferous period.
Rum-running	Rum-running	Rum-running, or bootlegging, is the illegal business of smuggling alcoholic beverages where such transportation is forbidden by law. Smuggling usually takes place to circumvent taxation or prohibition laws within a particular jurisdiction. The term rum-running is more commonly applied to smuggling over water; bootlegging is applied to smuggling over land.
Rum-running	Rum-running	It is believed that the term bootlegging originated during the American Civil War, when soldiers would sneak liquor into army camps by concealing pint bottles within their boots or beneath their trouser legs. Also, according to the PBS documentary Prohibition, the term bootlegging was popularized when thousands of city dwellers sold liquor from flasks they kept in their boot legs all across major cities and rural areas. The term rum-running was current by 1916, and was used during the Prohibition era in the United States (1920–1933), when ships from Bimini in the western Bahamas transported cheap Caribbean rum to Florida speakeasies. However, rum's cheapness made it a low-profit item for the rum-runners, and they soon moved on to smuggling Canadian whisky, French champagne, and English gin to major cities like New York City, Boston, and Chicago, where prices ran high. It was said that some ships carried $200,000 in contraband in a single run.
Rum-running	History	It was not long after the first taxes were implemented on alcoholic beverages that someone began to smuggle alcohol. The British government had "revenue cutters" in place to stop smugglers as early as the 16th century. Pirates often made extra money running rum to heavily taxed colonies. There were times when the sale of alcohol was limited for other reasons, such as laws against sales to American Indians in the Old West and Canada West or local prohibitions like the one on Prince Edward Island between 1901 and 1948.Industrial-scale smuggling flowed both ways across the Canada–United States border at different points in the early twentieth century, largely between Windsor, Ontario and Detroit, Michigan. Although Canada never had true nationwide prohibition, the federal government gave the provinces an easy means to ban alcohol under the War Measures Act (1914), and most provinces and the Yukon Territory already had enacted prohibition locally by 1918 when a regulation issued by the federal cabinet banned the interprovincial trade and importation of liquor. National prohibition in the United States did not begin until 1920, though many states had statewide prohibition before that. For the two-year interval, enough American liquor entered Canada illegally to undermine support for prohibition in Canada, so it was slowly lifted, beginning with Quebec and Yukon in 1919 and including all the provinces but Prince Edward Island by 1930. Additionally, Canada's version of prohibition had never included a ban on the manufacture of liquor for export. Soon the black-market trade was reversed with Canadian whisky and beer flowing in large quantities to the United States. Again, this illegal international trade undermined the support for prohibition in the receiving country, and the American version ended (at the national level) in 1933.
Rum-running	History	One of the most famous periods of rum-running began in the United States when Prohibition began on January 16, 1920, when the Eighteenth Amendment went into effect. This period lasted until the amendment was repealed with ratification of the Twenty-first Amendment on December 5, 1933. At first, there was much action on the seas, but after several months, the Coast Guard began reporting decreased smuggling activity. This was the start of the Bimini–Bahamas rum trade and the introduction of Bill McCoy.
Rum-running	History	With the start of prohibition, Captain McCoy began bringing rum from Bimini and the rest of the Bahamas into south Florida through Government Cut. The Coast Guard soon caught up with him, so he began to bring the illegal goods to just outside U.S. territorial waters and let smaller boats and other captains, such as Habana Joe, take the risk of bringing it to shore.
Rum-running	History	The rum-running business was very good, and McCoy soon bought a Gloucester knockabout schooner named Arethusa at auction and renamed her Tomoka. He installed a larger auxiliary, mounted a concealed machine gun on her deck, and refitted the fish pens below to accommodate as much contraband as she could hold. She became one of the most famous of the rum-runners, along with his two other ships hauling mostly Irish and Canadian whiskey as well as other fine liquors and wines to ports from Maine to Florida.
Rum-running	History	In the days of rum running, it was common for captains to add water to the bottles to stretch their profits or to re-label it as better goods. Often, cheap sparkling wine would become French champagne or Italian Spumante; unbranded liquor became top-of-the-line name brands. McCoy became famous for never adding water to his booze and selling only top brands. Although the phrase appears in print in 1882, this is one of several false etymologies for the origin of the term "The real McCoy".
Rum-running	History	On November 15, 1923, McCoy and Tomoka encountered the U.S. Coast Guard Cutter Seneca just outside U.S. territorial waters. A boarding party attempted to board, but McCoy chased them off with the machine gun. Tomoka tried to run, but Seneca placed a shell just off her hull, and William McCoy surrendered his ship and cargo.
Rum-running	History	The Rum Row McCoy is credited with the idea of bringing large boats just to the edge of the 3-mile (4.8 km) limit of U.S. jurisdiction and selling his wares there to "contact boats", local fishermen, and small boat captains. The small, quick boats could more easily outrun Coast Guard ships and could dock in any small river or eddy and transfer their cargo to a waiting truck. They were also known to load float planes and flying boats. Soon others were following suit, and the three-mile limit became known as "Rum Line" with the ships waiting called "Rum row". The Rum Line was extended to a 12-mile (19 km) limit by an act of the United States Congress on April 21, 1924, which made it harder for the smaller and less seaworthy craft to make the trip.Rum Row was not the only front for the Coast Guard. Rum-runners often made the trip through Canada via the Great Lakes and the Saint Lawrence Seaway and down the west coast to San Francisco and Los Angeles. Rum-running from Canada was also an issue, especially throughout prohibition in the early 1900s. There was a high number of distilleries in Canada, one of the most famous being Hiram Walker who developed Canadian Club Whisky. The French islands of Saint-Pierre and Miquelon, located south of Newfoundland, were an important base used by well-known smugglers, including Al Capone, Savannah Unknown, and Bill McCoy. The Gulf of Mexico also teemed with ships running from Mexico and the Bahamas to Galveston, Texas, the Louisiana swamps, and Alabama coast. By far the biggest Rum Row was in the New York/Philadelphia area off the New Jersey coast, where as many as 60 ships were seen at one time. One of the most notable New Jersey rum runners was Habana Joe, who could be seen at night running into remote areas in Raritan Bay with his flat-bottom skiff for running up on the beach, making his delivery, and speeding away.
Rum-running	History	With that much competition, the suppliers often flew large banners advertising their wares and threw parties with prostitutes on board their ships to draw customers. Rum Row was completely lawless, and many crews armed themselves not against government ships but against the other rum-runners, who would sometimes sink a ship and hijack its cargo rather than make the run to Canada or the Caribbean for fresh supplies.
Rum-running	History	The ships At the start, the rum-runner fleet consisted of a ragtag flotilla of fishing boats, such as the schooner Nellie J. Banks, excursion boats, and small merchant craft. As prohibition wore on, the stakes got higher and the ships became larger and more specialized. Converted fishing ships like McCoy's Tomoka waited on Rum Row and were soon joined by small motor freighters custom-built in Nova Scotia for rum running, with low, grey hulls, hidden compartments, and powerful wireless equipment. Examples include the Reo II. Specialized high-speed craft were built for the ship-to-shore runs. These high-speed boats were often luxury yachts and speedboats fitted with powerful aircraft engines, machine guns, and armor plating. Often, builders of rum-runners' ships also supplied Coast Guard vessels, such as Fred and Mirto Scopinich's Freeport Point Shipyard. Rum-runners often kept cans of used engine oil handy to pour on hot exhaust manifolds in case a screen of smoke was needed to escape the revenue ships.
Rum-running	History	On the government's side, the rum chasers were an assortment of patrol boats, inshore patrol, and harbor cutters. Most of the patrol boats were of the "six-bit" variety: 75-foot craft with a top speed of about 12 knots. There was also an assortment of launches, harbor tugs, and miscellaneous small craft.
Rum-running	History	The rum-runners were often faster and more maneuverable than government ships, and a rum-running captain could make several hundred thousand dollars a year. In comparison, the Commandant of the Coast Guard made just $6,000 annually, and seamen made $30/week. Because of this disparity, the rum-runners were generally willing to take bigger risks. They ran without lights at night and in fog, risking life and limb. Shores could sometimes be found littered with bottles from a rum-runner who sank after hitting a sandbar or a reef in the dark at high speed.The Coast Guard relied on hard work, reconnaissance, and big guns to get their job done. It was not uncommon for rum-runners' ships to be sold at auction shortly after a trial – ships were often sold back to the original owners. Some ships were captured three or four times before they were finally sunk or retired. In addition, the Coast Guard had other duties and often had to let a rum-runner go in order to assist a sinking vessel or handle another emergency.
Rum-running	History	Rum-running in Northern Europe in the 1920s and 1930s Prohibitive alcohol laws in Finland (total ban of alcohol from 1919 to 1931), Norway (liquor above 20 per cent abv 1917–1927) and the Swedish Bratt System which heavily restricted the sale of alcohol made these three countries attractive for alcohol smuggling from abroad. The main product used for smuggling were rectified spirits produced in Central Europe (Germany, Poland, Netherlands etc.). Alcohol was legally exported on large ships as tax-free produce via ports like Hamburg, Tallinn, Kiel and particularly the Free City of Danzig. Similar to the Rum Row near the U.S. coast, these ships usually did not leave international waters and the alcohol was clandestinely loaded onto smaller boats that illegally brought it into the destination countries. Despite various efforts led by Finland to fight contraband (Helsinki Convention for the Suppression of the Contraband Traffic in Alcoholic Liquors of 1925), the smugglers managed to bypass anti-smuggling laws, e.g., through the use of flags of convenience.
Rum-running	Alcohol smuggling today	For multiple reasons (including the avoidance of taxes and minimum purchase prices), alcohol smuggling is still a worldwide concern.
Rum-running	Alcohol smuggling today	In the United States, the smuggling of alcohol did not end with the repeal of prohibition. In the Appalachian United States, for example, the demand for moonshine was at an all-time high in the 1920s, but an era of rampant bootlegging in dry areas continued into the 1970s. Although the well-known bootleggers of the day may no longer be in business, bootlegging still exists, even if on a smaller scale. The state of Virginia has reported that it loses up to $20 million a year from illegal whiskey smuggling.The Government of the United Kingdom fails to collect an estimated £900 million in taxes due to alcohol smuggling activities.Absinthe was smuggled into the United States until it was legalized in 2007. Cuban rum is also sometimes smuggled into the United States, circumventing the embargo in existence since 1960.
Tioconazole	Tioconazole	Tioconazole is an antifungal medication of the imidazole class used to treat infections caused by a fungus or yeast. It is marketed under the brand names Trosyd and Gyno-Trosyd (Pfizer, now Johnson & Johnson). Tioconazole ointments serve to treat women's vaginal yeast infections. They are available in one day doses, as opposed to the 7-day treatments commonly used in the past.
Tioconazole	Tioconazole	Tioconazole topical (skin) preparations are also available for ringworm, jock itch, athlete's foot, and tinea versicolor or "sun fungus". It was patented in 1975 and approved for medical use in 1982.
Tioconazole	Side effects	Side effects of vaginal tioconazole may include temporary burning itching, or irritation of the vagina. Vaginal swelling or redness, difficulty or burning during urination, headache, abdominal pain, and upper respiratory tract infection have been reported by people using tioconazole. These side effects may be only temporary, and do not normally interfere with the patient's comfort enough to outweigh the result.
Tioconazole	Synthesis	Antimycotic imidazole derivative. A displacement reaction between 1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethanol and 2-chloro-3-(chloromethyl)thiophene is performed.
Hysteresis	Hysteresis	Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Plots of a single component of the moment often form a loop or hysteresis curve, where there are different values of one variable depending on the direction of change of another variable. This history dependence is the basis of memory in a hard disk drive and the remanence that retains a record of the Earth's magnetic field magnitude in the past. Hysteresis occurs in ferromagnetic and ferroelectric materials, as well as in the deformation of rubber bands and shape-memory alloys and many other natural phenomena. In natural systems it is often associated with irreversible thermodynamic change such as phase transitions and with internal friction; and dissipation is a common side effect.
Hysteresis	Hysteresis	Hysteresis can be found in physics, chemistry, engineering, biology, and economics. It is incorporated in many artificial systems: for example, in thermostats and Schmitt triggers, it prevents unwanted frequent switching. Hysteresis can be a dynamic lag between an input and an output that disappears if the input is varied more slowly; this is known as rate-dependent hysteresis. However, phenomena such as the magnetic hysteresis loops are mainly rate-independent, which makes a durable memory possible. Systems with hysteresis are nonlinear, and can be mathematically challenging to model. Some hysteretic models, such as the Preisach model (originally applied to ferromagnetism) and the Bouc–Wen model, attempt to capture general features of hysteresis; and there are also phenomenological models for particular phenomena such as the Jiles–Atherton model for ferromagnetism. It is difficult to define hysteresis precisely. Isaak D. Mayergoyz wrote "..the very meaning of hysteresis varies from one area to another, from paper to paper and from author to author. As a result, a stringent mathematical definition of hysteresis is needed in order to avoid confusion and ambiguity.".
Hysteresis	Etymology and history	The term "hysteresis" is derived from ὑστέρησις, an Ancient Greek word meaning "deficiency" or "lagging behind". It was coined in 1881 by Sir James Alfred Ewing to describe the behaviour of magnetic materials.Some early work on describing hysteresis in mechanical systems was performed by James Clerk Maxwell. Subsequently, hysteretic models have received significant attention in the works of Ferenc Preisach (Preisach model of hysteresis), Louis Néel and Douglas Hugh Everett in connection with magnetism and absorption. A more formal mathematical theory of systems with hysteresis was developed in the 1970s by a group of Russian mathematicians led by Mark Krasnosel'skii.
Hysteresis	Types	Rate-dependent One type of hysteresis is a lag between input and output. An example is a sinusoidal input X(t) that results in a sinusoidal output Y(t), but with a phase lag φ: sin sin ⁡(ωt−φ).
Hysteresis	Types	Such behavior can occur in linear systems, and a more general form of response is Y(t)=χiX(t)+∫0∞Φd(τ)X(t−τ)dτ, where χi is the instantaneous response and Φd(τ) is the impulse response to an impulse that occurred τ time units in the past. In the frequency domain, input and output are related by a complex generalized susceptibility that can be computed from Φd ; it is mathematically equivalent to a transfer function in linear filter theory and analogue signal processing.This kind of hysteresis is often referred to as rate-dependent hysteresis. If the input is reduced to zero, the output continues to respond for a finite time. This constitutes a memory of the past, but a limited one because it disappears as the output decays to zero. The phase lag depends on the frequency of the input, and goes to zero as the frequency decreases.When rate-dependent hysteresis is due to dissipative effects like friction, it is associated with power loss.
Hysteresis	Types	Rate-independent Systems with rate-independent hysteresis have a persistent memory of the past that remains after the transients have died out. The future development of such a system depends on the history of states visited, but does not fade as the events recede into the past. If an input variable X(t) cycles from X0 to X1 and back again, the output Y(t) may be Y0 initially but a different value Y2 upon return. The values of Y(t) depend on the path of values that X(t) passes through but not on the speed at which it traverses the path. Many authors restrict the term hysteresis to mean only rate-independent hysteresis. Hysteresis effects can be characterized using the Preisach model and the generalized Prandtl−Ishlinskii model.
Hysteresis	In engineering	Control systems In control systems, hysteresis can be used to filter signals so that the output reacts less rapidly than it otherwise would by taking recent system history into account. For example, a thermostat controlling a heater may switch the heater on when the temperature drops below A, but not turn it off until the temperature rises above B. (For instance, if one wishes to maintain a temperature of 20 °C then one might set the thermostat to turn the heater on when the temperature drops to below 18 °C and off when the temperature exceeds 22 °C).
Hysteresis	In engineering	Similarly, a pressure switch can be designed to exhibit hysteresis, with pressure set-points substituted for temperature thresholds. Electronic circuits Often, some amount of hysteresis is intentionally added to an electronic circuit to prevent unwanted rapid switching. This and similar techniques are used to compensate for contact bounce in switches, or noise in an electrical signal. A Schmitt trigger is a simple electronic circuit that exhibits this property. A latching relay uses a solenoid to actuate a ratcheting mechanism that keeps the relay closed even if power to the relay is terminated. Some positive feedback from the output to one input of a comparator can increase the natural hysteresis (a function of its gain) it exhibits.
Hysteresis	In engineering	Hysteresis is essential to the workings of some memristors (circuit components which "remember" changes in the current passing through them by changing their resistance).Hysteresis can be used when connecting arrays of elements such as nanoelectronics, electrochrome cells and memory effect devices using passive matrix addressing. Shortcuts are made between adjacent components (see crosstalk) and the hysteresis helps to keep the components in a particular state while the other components change states. Thus, all rows can be addressed at the same time instead of individually.
Hysteresis	In engineering	In the field of audio electronics, a noise gate often implements hysteresis intentionally to prevent the gate from "chattering" when signals close to its threshold are applied.
Hysteresis	In engineering	User interface design A hysteresis is sometimes intentionally added to computer algorithms. The field of user interface design has borrowed the term hysteresis to refer to times when the state of the user interface intentionally lags behind the apparent user input. For example, a menu that was drawn in response to a mouse-over event may remain on-screen for a brief moment after the mouse has moved out of the trigger region and the menu region. This allows the user to move the mouse directly to an item on the menu, even if part of that direct mouse path is outside of both the trigger region and the menu region. For instance, right-clicking on the desktop in most Windows interfaces will create a menu that exhibits this behavior.
Hysteresis	In engineering	Aerodynamics In aerodynamics, hysteresis can be observed when decreasing the angle of attack of a wing after stall, regarding the lift and drag coefficients. The angle of attack at which the flow on top of the wing reattaches is generally lower than the angle of attack at which the flow separates during the increase of the angle of attack.
Hysteresis	In engineering	Backlash Moving parts within machines, such as the components of a gear train, normally have a small gap between them, to allow movement and lubrication. As a consequence of this gap, any reversal in direction of a drive part will not be passed on immediately to the driven part. This unwanted delay is normally kept as small as practicable, and is usually called backlash. The amount of backlash will increase with time as the surfaces of moving parts wear.
Hysteresis	In mechanics	Elastic hysteresis In the elastic hysteresis of rubber, the area in the centre of a hysteresis loop is the energy dissipated due to material internal friction.
Hysteresis	In mechanics	Elastic hysteresis was one of the first types of hysteresis to be examined.The effect can be demonstrated using a rubber band with weights attached to it. If the top of a rubber band is hung on a hook and small weights are attached to the bottom of the band one at a time, it will stretch and get longer. As more weights are loaded onto it, the band will continue to stretch because the force the weights are exerting on the band is increasing. When each weight is taken off, or unloaded, the band will contract as the force is reduced. As the weights are taken off, each weight that produced a specific length as it was loaded onto the band now contracts less, resulting in a slightly longer length as it is unloaded. This is because the band does not obey Hooke's law perfectly. The hysteresis loop of an idealized rubber band is shown in the figure.
Hysteresis	In mechanics	In terms of force, the rubber band was harder to stretch when it was being loaded than when it was being unloaded. In terms of time, when the band is unloaded, the effect (the length) lagged behind the cause (the force of the weights) because the length has not yet reached the value it had for the same weight during the loading part of the cycle. In terms of energy, more energy was required during the loading than the unloading, the excess energy being dissipated as thermal energy.
Hysteresis	In mechanics	Elastic hysteresis is more pronounced when the loading and unloading is done quickly than when it is done slowly. Some materials such as hard metals don't show elastic hysteresis under a moderate load, whereas other hard materials like granite and marble do. Materials such as rubber exhibit a high degree of elastic hysteresis.
Hysteresis	In mechanics	When the intrinsic hysteresis of rubber is being measured, the material can be considered to behave like a gas. When a rubber band is stretched it heats up, and if it is suddenly released, it cools down perceptibly. These effects correspond to a large hysteresis from the thermal exchange with the environment and a smaller hysteresis due to internal friction within the rubber. This proper, intrinsic hysteresis can be measured only if the rubber band is thermally isolated.
Hysteresis	In mechanics	Small vehicle suspensions using rubber (or other elastomers) can achieve the dual function of springing and damping because rubber, unlike metal springs, has pronounced hysteresis and does not return all the absorbed compression energy on the rebound. Mountain bikes have made use of elastomer suspension, as did the original Mini car. The primary cause of rolling resistance when a body (such as a ball, tire, or wheel) rolls on a surface is hysteresis. This is attributed to the viscoelastic characteristics of the material of the rolling body.
Hysteresis	In mechanics	Contact angle hysteresis The contact angle formed between a liquid and solid phase will exhibit a range of contact angles that are possible. There are two common methods for measuring this range of contact angles. The first method is referred to as the tilting base method. Once a drop is dispensed on the surface with the surface level, the surface is then tilted from 0° to 90°. As the drop is tilted, the downhill side will be in a state of imminent wetting while the uphill side will be in a state of imminent dewetting. As the tilt increases the downhill contact angle will increase and represents the advancing contact angle while the uphill side will decrease; this is the receding contact angle. The values for these angles just prior to the drop releasing will typically represent the advancing and receding contact angles. The difference between these two angles is the contact angle hysteresis.
Hysteresis	In mechanics	The second method is often referred to as the add/remove volume method. When the maximum liquid volume is removed from the drop without the interfacial area decreasing the receding contact angle is thus measured. When volume is added to the maximum before the interfacial area increases, this is the advancing contact angle. As with the tilt method, the difference between the advancing and receding contact angles is the contact angle hysteresis. Most researchers prefer the tilt method; the add/remove method requires that a tip or needle stay embedded in the drop which can affect the accuracy of the values, especially the receding contact angle.
Hysteresis	In mechanics	Bubble shape hysteresis The equilibrium shapes of bubbles expanding and contracting on capillaries (blunt needles) can exhibit hysteresis depending on the relative magnitude of the maximum capillary pressure to ambient pressure, and the relative magnitude of the bubble volume at the maximum capillary pressure to the dead volume in the system. The bubble shape hysteresis is a consequence of gas compressibility, which causes the bubbles to behave differently across expansion and contraction. During expansion, bubbles undergo large non equilibrium jumps in volume, while during contraction the bubbles are more stable and undergo a relatively smaller jump in volume resulting in an asymmetry across expansion and contraction. The bubble shape hysteresis is qualitatively similar to the adsorption hysteresis, and as in the contact angle hysteresis, the interfacial properties play an important role in bubble shape hysteresis.
Hysteresis	In mechanics	The existence of the bubble shape hysteresis has important consequences in interfacial rheology experiments involving bubbles. As a result of the hysteresis, not all sizes of the bubbles can be formed on a capillary. Further the gas compressibility causing the hysteresis leads to unintended complications in the phase relation between the applied changes in interfacial area to the expected interfacial stresses. These difficulties can be avoided by designing experimental systems to avoid the bubble shape hysteresis.
Hysteresis	In mechanics	Adsorption hysteresis Hysteresis can also occur during physical adsorption processes. In this type of hysteresis, the quantity adsorbed is different when gas is being added than it is when being removed. The specific causes of adsorption hysteresis are still an active area of research, but it is linked to differences in the nucleation and evaporation mechanisms inside mesopores. These mechanisms are further complicated by effects such as cavitation and pore blocking.
Hysteresis	In mechanics	In physical adsorption, hysteresis is evidence of mesoporosity-indeed, the definition of mesopores (2–50 nm) is associated with the appearance (50 nm) and disappearance (2 nm) of mesoporosity in nitrogen adsorption isotherms as a function of Kelvin radius. An adsorption isotherm showing hysteresis is said to be of Type IV (for a wetting adsorbate) or Type V (for a non-wetting adsorbate), and hysteresis loops themselves are classified according to how symmetric the loop is. Adsorption hysteresis loops also have the unusual property that it is possible to scan within a hysteresis loop by reversing the direction of adsorption while on a point on the loop. The resulting scans are called "crossing," "converging," or "returning," depending on the shape of the isotherm at this point.
Hysteresis	In mechanics	Matric potential hysteresis The relationship between matric water potential and water content is the basis of the water retention curve. Matric potential measurements (Ψm) are converted to volumetric water content (θ) measurements based on a site or soil specific calibration curve. Hysteresis is a source of water content measurement error. Matric potential hysteresis arises from differences in wetting behaviour causing dry medium to re-wet; that is, it depends on the saturation history of the porous medium. Hysteretic behaviour means that, for example, at a matric potential (Ψm) of 5 kPa, the volumetric water content (θ) of a fine sandy soil matrix could be anything between 8% and 25%.Tensiometers are directly influenced by this type of hysteresis. Two other types of sensors used to measure soil water matric potential are also influenced by hysteresis effects within the sensor itself. Resistance blocks, both nylon and gypsum based, measure matric potential as a function of electrical resistance. The relation between the sensor's electrical resistance and sensor matric potential is hysteretic. Thermocouples measure matric potential as a function of heat dissipation. Hysteresis occurs because measured heat dissipation depends on sensor water content, and the sensor water content–matric potential relationship is hysteretic. As of 2002, only desorption curves are usually measured during calibration of soil moisture sensors. Despite the fact that it can be a source of significant error, the sensor specific effect of hysteresis is generally ignored.
Hysteresis	In materials	Magnetic hysteresis When an external magnetic field is applied to a ferromagnetic material such as iron, the atomic domains align themselves with it. Even when the field is removed, part of the alignment will be retained: the material has become magnetized. Once magnetized, the magnet will stay magnetized indefinitely. To demagnetize it requires heat or a magnetic field in the opposite direction. This is the effect that provides the element of memory in a hard disk drive.
Hysteresis	In materials	The relationship between field strength H and magnetization M is not linear in such materials. If a magnet is demagnetized (H = M = 0) and the relationship between H and M is plotted for increasing levels of field strength, M follows the initial magnetization curve. This curve increases rapidly at first and then approaches an asymptote called magnetic saturation. If the magnetic field is now reduced monotonically, M follows a different curve. At zero field strength, the magnetization is offset from the origin by an amount called the remanence. If the H-M relationship is plotted for all strengths of applied magnetic field the result is a hysteresis loop called the main loop. The width of the middle section is twice the coercivity of the material.A closer look at a magnetization curve generally reveals a series of small, random jumps in magnetization called Barkhausen jumps. This effect is due to crystallographic defects such as dislocations.Magnetic hysteresis loops are not exclusive to materials with ferromagnetic ordering. Other magnetic orderings, such as spin glass ordering, also exhibit this phenomenon.
Hysteresis	In materials	Physical origin The phenomenon of hysteresis in ferromagnetic materials is the result of two effects: rotation of magnetization and changes in size or number of magnetic domains. In general, the magnetization varies (in direction but not magnitude) across a magnet, but in sufficiently small magnets, it does not. In these single-domain magnets, the magnetization responds to a magnetic field by rotating. Single-domain magnets are used wherever a strong, stable magnetization is needed (for example, magnetic recording).
Hysteresis	In materials	Larger magnets are divided into regions called domains. Across each domain, the magnetization does not vary; but between domains are relatively thin domain walls in which the direction of magnetization rotates from the direction of one domain to another. If the magnetic field changes, the walls move, changing the relative sizes of the domains. Because the domains are not magnetized in the same direction, the magnetic moment per unit volume is smaller than it would be in a single-domain magnet; but domain walls involve rotation of only a small part of the magnetization, so it is much easier to change the magnetic moment. The magnetization can also change by addition or subtraction of domains (called nucleation and denucleation).
Hysteresis	In materials	Magnetic hysteresis models The most known empirical models in hysteresis are Preisach and Jiles-Atherton models. These models allow an accurate modeling of the hysteresis loop and are widely used in the industry. However, these models lose the connection with thermodynamics and the energy consistency is not ensured. A more recent model, with a more consistent thermodynamical foundation, is the vectorial incremental nonconservative consistent hysteresis (VINCH) model of Lavet et al. (2011) Applications There are a great variety of applications of the hysteresis in ferromagnets. Many of these make use of their ability to retain a memory, for example magnetic tape, hard disks, and credit cards. In these applications, hard magnets (high coercivity) like iron are desirable, such that as much energy is absorbed as possible during the write operation and the resultant magnetized information is not easily erased.
Hysteresis	In materials	On the other hand, magnetically soft (low coercivity) iron is used for the cores in electromagnets. The low coercivity minimizes the energy loss associated with hysteresis, as the magnetic field periodically reverses in the presence of an alternating current. The low energy loss during a hysteresis loop is the reason why soft iron is used for transformer cores and electric motors.
Hysteresis	In materials	Electrical hysteresis Electrical hysteresis typically occurs in ferroelectric material, where domains of polarization contribute to the total polarization. Polarization is the electrical dipole moment (either C·m−2 or C·m). The mechanism, an organization of the polarization into domains, is similar to that of magnetic hysteresis.
Hysteresis	In materials	Liquid–solid-phase transitions Hysteresis manifests itself in state transitions when melting temperature and freezing temperature do not agree. For example, agar melts at 85 °C (185 °F) and solidifies from 32 to 40 °C (90 to 104 °F). This is to say that once agar is melted at 85 °C, it retains a liquid state until cooled to 40 °C. Therefore, from the temperatures of 40 to 85 °C, agar can be either solid or liquid, depending on which state it was before.
Hysteresis	In biology	Cell biology and genetics Hysteresis in cell biology often follows bistable systems where the same input state can lead to two different, stable outputs. Where bistability can lead to digital, switch-like outputs from the continuous inputs of chemical concentrations and activities, hysteresis makes these systems more resistant to noise. These systems are often characterized by higher values of the input required to switch into a particular state as compared to the input required to stay in the state, allowing for a transition that is not continuously reversible, and thus less susceptible to noise. Cells undergoing cell division exhibit hysteresis in that it takes a higher concentration of cyclins to switch them from G2 phase into mitosis than to stay in mitosis once begun.Biochemical systems can also show hysteresis-like output when slowly varying states that are not directly monitored are involved, as in the case of the cell cycle arrest in yeast exposed to mating pheromone. Here, the duration of cell cycle arrest depends not only on the final level of input Fus3, but also on the previously achieved Fus3 levels. This effect is achieved due to the slower time scales involved in the transcription of intermediate Far1, such that the total Far1 activity reaches its equilibrium value slowly, and for transient changes in Fus3 concentration, the response of the system depends on the Far1 concentration achieved with the transient value. Experiments in this type of hysteresis benefit from the ability to change the concentration of the inputs with time. The mechanisms are often elucidated by allowing independent control of the concentration of the key intermediate, for instance, by using an inducible promoter.
Hysteresis	In biology	Darlington in his classic works on genetics discussed hysteresis of the chromosomes, by which he meant "failure of the external form of the chromosomes to respond immediately to the internal stresses due to changes in their molecular spiral", as they lie in a somewhat rigid medium in the limited space of the cell nucleus.
Hysteresis	In biology	In developmental biology, cell type diversity is regulated by long range-acting signaling molecules called morphogens that pattern uniform pools of cells in a concentration- and time-dependent manner. The morphogen sonic hedgehog (Shh), for example, acts on limb bud and neural progenitors to induce expression of a set of homeodomain-containing transcription factors to subdivide these tissues into distinct domains. It has been shown that these tissues have a 'memory' of previous exposure to Shh.
Hysteresis	In biology	In neural tissue, this hysteresis is regulated by a homeodomain (HD) feedback circuit that amplifies Shh signaling. In this circuit, expression of Gli transcription factors, the executors of the Shh pathway, is suppressed. Glis are processed to repressor forms (GliR) in the absence of Shh, but in the presence of Shh, a proportion of Glis are maintained as full-length proteins allowed to translocate to the nucleus, where they act as activators (GliA) of transcription. By reducing Gli expression then, the HD transcription factors reduce the total amount of Gli (GliT), so a higher proportion of GliT can be stabilized as GliA for the same concentration of Shh.
Hysteresis	In biology	Immunology There is some evidence that T cells exhibit hysteresis in that it takes a lower signal threshold to activate T cells that have been previously activated. Ras GTPase activation is required for downstream effector functions of activated T cells. Triggering of the T cell receptor induces high levels of Ras activation, which results in higher levels of GTP-bound (active) Ras at the cell surface. Since higher levels of active Ras have accumulated at the cell surface in T cells that have been previously stimulated by strong engagement of the T cell receptor, weaker subsequent T cell receptor signals received shortly afterwards will deliver the same level of activation due to the presence of higher levels of already activated Ras as compared to a naïve cell.
Hysteresis	In biology	Neuroscience The property by which some neurons do not return to their basal conditions from a stimulated condition immediately after removal of the stimulus is an example of hysteresis. Neuropsychology Neuropsychology, in exploring the neural correlates of consciousness, interfaces with neuroscience, although the complexity of the central nervous system is a challenge to its study (that is, its operation resists easy reduction). Context-dependent memory and state-dependent memory show hysteretic aspects of neurocognition.
Hysteresis	In biology	Respiratory physiology Lung hysteresis is evident when observing the compliance of a lung on inspiration versus expiration. The difference in compliance (Δvolume/Δpressure) is due to the additional energy required to overcome surface tension forces during inspiration to recruit and inflate additional alveoli.The transpulmonary pressure vs Volume curve of inhalation is different from the Pressure vs Volume curve of exhalation, the difference being described as hysteresis. Lung volume at any given pressure during inhalation is less than the lung volume at any given pressure during exhalation.
Hysteresis	In biology	Voice and speech physiology A hysteresis effect may be observed in voicing onset versus offset. The threshold value of the subglottal pressure required to start the vocal fold vibration is lower than the threshold value at which the vibration stops, when other parameters are kept constant. In utterances of vowel-voiceless consonant-vowel sequences during speech, the intraoral pressure is lower at the voice onset of the second vowel compared to the voice offset of the first vowel, the oral airflow is lower, the transglottal pressure is larger and the glottal width is smaller.
Hysteresis	In biology	Ecology and epidemiology Hysteresis is a commonly encountered phenomenon in ecology and epidemiology, where the observed equilibrium of a system can not be predicted solely based on environmental variables, but also requires knowledge of the system's past history. Notable examples include the theory of spruce budworm outbreaks and behavioral-effects on disease transmission.It is commonly examined in relation to critical transitions between ecosystem or community types in which dominant competitors or entire landscapes can change in a largely irreversible fashion.
Hysteresis	In ocean and climate science	Complex ocean and climate models rely on the principle.
Hysteresis	In economics	Economic systems can exhibit hysteresis. For example, export performance is subject to strong hysteresis effects: because of the fixed transportation costs it may take a big push to start a country's exports, but once the transition is made, not much may be required to keep them going.
Hysteresis	In economics	When some negative shock reduces employment in a company or industry, fewer employed workers then remain. As usually the employed workers have the power to set wages, their reduced number incentivizes them to bargain for even higher wages when the economy again gets better instead of letting the wage be at the equilibrium wage level, where the supply and demand of workers would match. This causes hysteresis: the unemployment becomes permanently higher after negative shocks.
Hysteresis	In economics	Permanently higher unemployment The idea of hysteresis is used extensively in the area of labor economics, specifically with reference to the unemployment rate. According to theories based on hysteresis, severe economic downturns (recession) and/or persistent stagnation (slow demand growth, usually after a recession) cause unemployed individuals to lose their job skills (commonly developed on the job) or to find that their skills have become obsolete, or become demotivated, disillusioned or depressed or lose job-seeking skills. In addition, employers may use time spent in unemployment as a screening tool, i.e., to weed out less desired employees in hiring decisions. Then, in times of an economic upturn, recovery, or "boom", the affected workers will not share in the prosperity, remaining unemployed for long periods (e.g., over 52 weeks). This makes unemployment "structural", i.e., extremely difficult to reduce simply by increasing the aggregate demand for products and labor without causing increased inflation. That is, it is possible that a ratchet effect in unemployment rates exists, so a short-term rise in unemployment rates tends to persist. For example, traditional anti-inflationary policy (the use of recession to fight inflation) leads to a permanently higher "natural" rate of unemployment (more scientifically known as the NAIRU). This occurs first because inflationary expectations are "sticky" downward due to wage and price rigidities (and so adapt slowly over time rather than being approximately correct as in theories of rational expectations) and second because labor markets do not clear instantly in response to unemployment.
Hysteresis	In economics	The existence of hysteresis has been put forward as a possible explanation for the persistently high unemployment of many economies in the 1990s. Hysteresis has been invoked by Olivier Blanchard among others to explain the differences in long run unemployment rates between Europe and the United States. Labor market reform (usually meaning institutional change promoting more flexible wages, firing, and hiring) or strong demand-side economic growth may not therefore reduce this pool of long-term unemployed. Thus, specific targeted training programs are presented as a possible policy solution. However, the hysteresis hypothesis suggests such training programs are aided by persistently high demand for products (perhaps with incomes policies to avoid increased inflation), which reduces the transition costs out of unemployment and into paid employment easier.
Hysteresis	Additional considerations	Models of hysteresis Each subject that involves hysteresis has models that are specific to the subject. In addition, there are hysteretic models that capture general features of many systems with hysteresis. An example is the Preisach model of hysteresis, which represents a hysteresis nonlinearity as a linear superposition of square loops called non-ideal relays. Many complex models of hysteresis arise from the simple parallel connection, or superposition, of elementary carriers of hysteresis termed hysterons.
Hysteresis	Additional considerations	A simple and intuitive parametric description of various hysteresis loops may be found in the Lapshin model. Along with the smooth loops, substitution of trapezoidal, triangular or rectangular pulses instead of the harmonic functions allows piecewise-linear hysteresis loops frequently used in discrete automatics to be built in the model. There are implementations of the hysteresis loop model in Mathcad and in R programming language.The Bouc–Wen model of hysteresis is often used to describe non-linear hysteretic systems. It was introduced by Bouc and extended by Wen, who demonstrated its versatility by producing a variety of hysteretic patterns. This model is able to capture in analytical form, a range of shapes of hysteretic cycles which match the behaviour of a wide class of hysteretical systems; therefore, given its versability and mathematical tractability, the Bouc–Wen model has quickly gained popularity and has been extended and applied to a wide variety of engineering problems, including multi-degree-of-freedom (MDOF) systems, buildings, frames, bidirectional and torsional response of hysteretic systems two- and three-dimensional continua, and soil liquefaction among others. The Bouc–Wen model and its variants/extensions have been used in applications of structural control, in particular in the modeling of the behaviour of magnetorheological dampers, base isolation devices for buildings and other kinds of damping devices; it has also been used in the modelling and analysis of structures built of reinforced concrete, steel, masonry and timber.. The most important extension of Bouc-Wen Model was carried out by Baber and Noori and later by Noori and co-workers. That extended model, named, BWBN, can reproduce the complex shear pinching or slip-lock phenomenon that earlier model could not reproduce. BWBN model has been widely used in a wide spectrum of applications and have been incorporated in several software codes such as OpenSees.
Hysteresis	Additional considerations	Energy When hysteresis occurs with extensive and intensive variables, the work done on the system is the area under the hysteresis graph.
Fuel gauge	Fuel gauge	In automotive and aerospace engineering, a fuel gauge is an instrument used to indicate the amount of fuel in a fuel tank. In electrical engineering, the term is used for ICs determining the current State of Charge of accumulators.
Fuel gauge	Motor vehicles	As used in vehicles, the gauge consists of two parts: The sending unit - in the tank The indicator - on the dashboardThe sending unit usually uses a float connected to a potentiometer, typically printed ink design in a modern automobile. As the tank empties, the float drops and slides a moving contact along the resistor, increasing its resistance. In addition, when the resistance is at a certain point, it will also turn on a "low fuel" light on some vehicles.Meanwhile, the indicator unit (usually mounted on the dashboard) is measuring and displaying the amount of electric current flowing through the sending unit. When the tank level is high and maximum current is flowing, the needle points to "F" indicating a full tank. When the tank is empty and the least current is flowing, the needle points to "E" indicating an empty tank; some vehicles use the indicators "1" (for full) and "0" or "R" (for empty) instead.
Fuel gauge	Motor vehicles	The system can be fail-safe. If an electrical fault opens, the electrical circuit causes the indicator to show the tank as being empty (theoretically provoking the driver to refill the tank) rather than full (which would allow the driver to run out of fuel with no prior notification). Corrosion or wear of the potentiometer will provide erroneous readings of fuel level. However, this system has a potential risk associated with it. An electric current is sent through the variable resistor to which a float is connected, so that the value of resistance depends on the fuel level. In most automotive fuel gauges such resistors are on the inward side of the gauge, i.e., inside the fuel tank. Sending current through such a resistor has a fire hazard and an explosion risk associated with it. These resistance sensors are also showing an increased failure rate with the incremental additions of alcohol in automotive gasoline fuel. Alcohol increases the corrosion rate at the potentiometer, as it is capable of carrying current like water. Potentiometer applications for alcohol fuel use a pulse-and-hold methodology, with a periodic signal being sent to determine fuel level decreasing the corrosion potential. Therefore, demand for another safer, non-contact method for fuel level is desired.
Fuel gauge	Motor vehicles	Moylan arrow Since the early 1990s, many fuel gauges have included an icon with a fuel pump and an arrow, indicating the side of the vehicle on which the fuel filler is located. The use of the icon and arrow was invented in 1986 by Jim Moylan, a designer for Ford Motor Company. After he proposed the idea in April 1986, the 1989 Ford Escort and Mercury Tracer were the first vehicles to see it implemented. Other automotive companies noticed the addition and began to incorporate it into their own fuel gauges.
Fuel gauge	Aircraft	Magnetoresistance type fuel level sensors, now becoming common in small aircraft applications, offer a potential alternative for automotive use. These fuel level sensors work similar to the potentiometer example, however a sealed detector at the float pivot determines the angular position of a magnet pair at the pivot end of the float arm. These are highly accurate, and the electronics are completely outside the fuel. The non-contact nature of these sensors address the fire and explosion hazard, and also the issues related to any fuel combinations or additives to gasoline or to any alcohol fuel mixtures. Magneto resistive sensors are suitable for all fuel or fluid combinations, including LPG and LNG. The fuel level output for these senders can be ratiometric voltage or preferable CAN bus digital. These sensors also fail-safe in that they either provide a level output or nothing.
Fuel gauge	Aircraft	Systems that measure large fuel tanks (including underground storage tanks) may use the same electro-mechanical principle or may make use of a pressure sensor, sometimes connected to a mercury manometer.
Fuel gauge	Aircraft	Many large transport aircraft use a different fuel gauge design principle. An aircraft may use a number (around 30 on an A320) of low voltage tubular capacitor probes where the fuel becomes the dielectric. At different fuel levels, different values of capacitance are measured and therefore the level of fuel can be determined. In early designs, the profiles and values of individual probes were chosen to compensate for fuel tank shape and aircraft pitch and roll attitudes. In more modern aircraft, the probes tend to be linear (capacitance proportional to fuel height) and the fuel computer works out how much fuel there is (slightly different on different manufacturers). This has the advantage that a faulty probe may be identified and eliminated from the fuel calculations. In total this system can be more than 99% accurate. Since most commercial aircraft only take on board fuel necessary for the intended flight (with appropriate safety margins), the system allows the fuel load to be preselected, causing the fuel delivery to be shut off when the intended load has been taken on board.
Fuel gauge	Fuel Gauge ICs	In electronics there are different ICs available, which control the current State of Charge of accumulators. These devices are also called "Fuel Gauge".
Vaccine (instrument)	Vaccine (instrument)	Vaccine (or sometimes vaksin) are rudimentary single-note trumpets found in Haiti and, to a lesser extent, the Dominican Republic as well as Jamaica. They consist of a simple tube, usually bamboo, with a mouthpiece at one end. They are thus also referred to as banbou or bambú, as well as bois bourrique (or bwa bourik), granboe, fututo, or boom pipe. They are not to be confused with other Haitian handmade trumpets called konè or klewon, made of a yard-long white metal tube with a flared horn, called kata.Vaccine players are known as banboulyès.
Vaccine (instrument)	Origins	Haitian ethnographer Jean Bernard traces the vaksin back to indigenous precolonial peoples of Haiti. However both Thompson and Holloway draw links to the single-note Bakongo bamboo trumpets called disoso, themselves originated in Mbuti hocketing music. Gillis also likens them to trumpets used in Bambara broto music along the Niger, and Jamaican Kumina.
Vaccine (instrument)	Construction	Traditionally, vaccine are made of a length of bamboo, hollowed-out and dried, with a node membrane pierced and wrapped with leather or bicycle inner-tube rubber to form a mouthpiece at one end. One or more segments are taken from higher or lower in the bamboo trunk to fashion vaccines; usually more than 1 m long and 5 to 7 cm in diameter. Each one is cut shorter or longer in order to produce a higher or lower tone: bas banbou is long and gives a low-pitched sound, and charlemagne banbou is short and is pitched high.McAlister explains that Afro-Hispaniolan lore involves asking the bamboo plant for its use and leaving a small payment in its place. Landies witnessed this process, which she described as follows: "the harvest of the bamboo was accompanied by an offering. [...] [It] is harvested with the permission of Simbi, a Petwo Lwa who loves water, as bamboo in the Dominican Republic grows in moist land, e.g., along rivers"On occasion, iron or plastic pipes are substituted for the bamboo.
Vaccine (instrument)	Playing	A typical vaccine band is composed of three to five players, usually marching abreast of each other. Players use a method called hocketing, whereby each individual blows a single tone rhythmically to create an ostinato motif together. These motifs are usually composed through a process of group improvisation.To keep rhythm, vaccine players also beat a rhythmic timeline, called kata with a long stick on the side of the tube, making the instrument both melodic and percussive.
Vaccine (instrument)	Tuning and scale	Within an ostinato, vaccine tones stack up in approximate third intervals to each other—creating tritones and arpeggiated diminished chords, but without a harmonic intent—with the two treble-most vaccines often tuned a semitone apart. Landies also reports other intervals between the lowest two voices. One of the vaccine serves as the tonal center of the motif.
Vaccine (instrument)	Uses	Most importantly, vaccines are a key component of rara orchestras. In his 1941 article, Courlander wrote that rara bands "seldom have drums and depend almost entirely on vaccines"; though both Lomax's mid-1930s and McAllister's early 1990s studies report many more instruments—mostly percussive—as part of rara orchestras. Scholars also report vaccines used as signal horns by parties of agricultural workers, fishermen, stevedores as well as sometimes used in dances of the Congo cycle.
HemoSpat	HemoSpat	HemoSpat is bloodstain pattern analysis software created by FORident Software in 2006. Using photos from a bloodshed incident at a crime scene, a bloodstain pattern analyst can use HemoSpat to calculate the area-of-origin of impact patterns. This information may be useful for determining position and posture of suspects and victims, sequencing of events, corroborating or refuting testimony, and for crime scene reconstruction.
HemoSpat	HemoSpat	The results of the analyses may be viewed in 2D within the software as top-down, side, and front views, or exported to several 3D formats for integration with point cloud or modelling software. The formats which HemoSpat exports include: AUTOCAD DXF COLLADA PLY VRML Wavefront OBJHemoSpat is capable of calculating impact pattern origins with only part of the pattern available, as well as impacts on non-orthogonal surfaces.
HemoSpat	HemoSpat	HemoSpat has also been used in research into what kind of information may be captured from cast-off patterns, methods of scene documentation, and in improving area-of-origin calculations.
Ian Roberts (linguist)	Ian Roberts (linguist)	Ian G. Roberts is Professor of Linguistics at the University of Cambridge and a fellow of Downing College, Cambridge. He also serves on the Advisory Council of METI (Messaging Extraterrestrial Intelligence). He received his PhD from the University of Southern California in 1985 and taught at the Universities of Geneva (1985–1993), Bangor (1991–1996) and Stuttgart (1996–2000) before taking up his present position at Cambridge in 2000. He is a fellow of Downing College. Professor Roberts is a generative linguist and enthusiastic adopter of Chomsky's Minimalist Program. He has published widely in the synchronic and diachronic syntax of Romance and Germanic languages and Welsh.
HP WinRunner	HP WinRunner	HP WinRunner software was an automated functional GUI testing tool that allowed a user to record and play back user interface (UI) interactions as test scripts. As a functional test suite, it worked with HP QuickTest Professional and supported enterprise quality assurance. It captured, verified and replayed user interactions automatically, in order to identify defects and determine whether business processes worked as designed. The software implemented a proprietary Test Script Language (TSL) that allowed customization and parameterization of user input. HP WinRunner was originally written by Mercury Interactive. Mercury Interactive was subsequently acquired by Hewlett Packard (HP) in 2006. On February 15, 2008, HP Software Division announced the end of support for HP WinRunner versions 7.5, 7.6, 8.0, 8.2, 9.2—suggesting migration to HP Functional Testing software as a replacement.
Sialoadhesin	Sialoadhesin	Sialoadhesin is a cell adhesion molecule found on the surface of macrophages. It is found in especially high amounts on macrophages of the spleen, liver, lymph node, bone marrow, colon, and lungs. Also, in patients with rheumatoid arthritis, the protein has been found in great amounts on macrophages of the affected tissues. It is defined as an I-type lectin, since it contains 17 immunoglobulin (Ig) domains (one variable domain and 16 constant domains), and thus also belongs to the immunoglobulin superfamily (IgSF). Sialoadhesin binds to certain molecules called sialic acids. During this binding process a salt bridge (protein) is formed between a highly conserved arginine residue (from the v-set domain to the 3'-sialyllactose) and the carboxylate group of the sialic acid. Since sialoadhesin binds sialic acids with its N-terminal IgV-domain, it is also a member of the SIGLEC family. Alternate names for sialoadhesin include siglec-1 and CD169 (cluster of differentiation 169).Sialoadhesin predominantly binds neutrophils, but can also bind monocytes, natural killer cells, B cells and a subset of cytotoxic T cells by interacting with sialic acid molecules in the ligands on their surfaces.Sialoadhesin (CD169) positive macrophages, along with mesenchymal stem cells and beta-adrenergic neurons, form the hematopoietic stem cell niche in the bone marrow. CD169+ macrophages mediate signaling between the various cells and seem to promote hematopoietic stem cell retention to the niche.
Dubnium	Dubnium	Dubnium is a synthetic chemical element with the symbol Db and atomic number 105. It is highly radioactive: the most stable known isotope, dubnium-268, has a half-life of about 16 hours. This greatly limits extended research on the element.
Dubnium	Dubnium	Dubnium does not occur naturally on Earth and is produced artificially. The Soviet Joint Institute for Nuclear Research (JINR) claimed the first discovery of the element in 1968, followed by the American Lawrence Berkeley Laboratory in 1970. Both teams proposed their names for the new element and used them without formal approval. The long-standing dispute was resolved in 1993 by an official investigation of the discovery claims by the Transfermium Working Group, formed by the International Union of Pure and Applied Chemistry and the International Union of Pure and Applied Physics, resulting in credit for the discovery being officially shared between both teams. The element was formally named dubnium in 1997 after the town of Dubna, the site of the JINR.
Dubnium	Dubnium	Theoretical research establishes dubnium as a member of group 5 in the 6d series of transition metals, placing it under vanadium, niobium, and tantalum. Dubnium should share most properties, such as its valence electron configuration and having a dominant +5 oxidation state, with the other group 5 elements, with a few anomalies due to relativistic effects. A limited investigation of dubnium chemistry has confirmed this.
Dubnium	Introduction	The heaviest atomic nuclei are created in nuclear reactions that combine two other nuclei of unequal size into one; roughly, the more unequal the two nuclei in terms of mass, the greater the possibility that the two react. The material made of the heavier nuclei is made into a target, which is then bombarded by the beam of lighter nuclei. Two nuclei can fuse into one only if they approach each other closely enough; normally, nuclei (all positively charged) repel each other due to electrostatic repulsion. The strong interaction can overcome this repulsion but only within a very short distance from a nucleus; beam nuclei are thus greatly accelerated in order to make such repulsion insignificant compared to the velocity of the beam nucleus. Coming close alone is not enough for two nuclei to fuse: when two nuclei approach each other, they usually remain together for approximately 10−20 seconds and then part ways (not necessarily in the same composition as before the reaction) rather than form a single nucleus. If fusion does occur, the temporary merger—termed a compound nucleus—is an excited state. To lose its excitation energy and reach a more stable state, a compound nucleus either fissions or ejects one or several neutrons, which carry away the energy. This occurs in approximately 10−16 seconds after the initial collision.The beam passes through the target and reaches the next chamber, the separator; if a new nucleus is produced, it is carried with this beam. In the separator, the newly produced nucleus is separated from other nuclides (that of the original beam and any other reaction products) and transferred to a surface-barrier detector, which stops the nucleus. The exact location of the upcoming impact on the detector is marked; also marked are its energy and the time of the arrival. The transfer takes about 10−6 seconds; in order to be detected, the nucleus must survive this long. The nucleus is recorded again once its decay is registered, and the location, the energy, and the time of the decay are measured.Stability of a nucleus is provided by the strong interaction. However, its range is very short; as nuclei become larger, their influence on the outermost nucleons (protons and neutrons) weakens. At the same time, the nucleus is torn apart by electrostatic repulsion between protons, as it has unlimited range. Nuclei of the heaviest elements are thus theoretically predicted and have so far been observed to primarily decay via decay modes that are caused by such repulsion: alpha decay and spontaneous fission; these modes are predominant for nuclei of superheavy elements. Alpha decays are registered by the emitted alpha particles, and the decay products are easy to determine before the actual decay; if such a decay or a series of consecutive decays produces a known nucleus, the original product of a reaction can be determined arithmetically. Spontaneous fission, however, produces various nuclei as products, so the original nuclide cannot be determined from its daughters.The information available to physicists aiming to synthesize one of the heaviest elements is thus the information collected at the detectors: location, energy, and time of arrival of a particle to the detector, and those of its decay. The physicists analyze this data and seek to conclude that it was indeed caused by a new element and could not have been caused by a different nuclide than the one claimed. Often, provided data is insufficient for a conclusion that a new element was definitely created and there is no other explanation for the observed effects; errors in interpreting data have been made.
Dubnium	Discovery	Background Uranium, element 92, is the heaviest element to occur in significant quantities in nature; heavier elements can only be practically produced by synthesis. The first synthesis of a new element—neptunium, element 93—was achieved in 1940 by a team of researchers in the United States. In the following years, American scientists synthesized the elements up to mendelevium, element 101, which was synthesized in 1955. From element 102, the priority of discoveries was contested between American and Soviet physicists. Their rivalry resulted in a race for new elements and credit for their discoveries, later named the Transfermium Wars.
Dubnium	Discovery	Reports The first report of the discovery of element 105 came from the Joint Institute for Nuclear Research (JINR) in Dubna, Moscow Oblast, Soviet Union, in April 1968. The scientists bombarded 243Am with a beam of 22Ne ions, and reported 9.4 MeV (with a half-life of 0.1–3 seconds) and 9.7 MeV (t1/2 > 0.05 s) alpha activities followed by alpha activities similar to those of either 256103 or 257103. Based on prior theoretical predictions, the two activity lines were assigned to 261105 and 260105, respectively.
Dubnium	Discovery	24395Am + 2210Ne → 265−x105 + x n (x = 4, 5)After observing the alpha decays of element 105, the researchers aimed to observe spontaneous fission (SF) of the element and study the resulting fission fragments. They published a paper in February 1970, reporting multiple examples of two such activities, with half-lives of 14 ms and 2.2±0.5 s. They assigned the former activity to 242mfAm and ascribed the latter activity to an isotope of element 105. They suggested that it was unlikely that this activity could come from a transfer reaction instead of element 105, because the yield ratio for this reaction was significantly lower than that of the 242mfAm-producing transfer reaction, in accordance with theoretical predictions. To establish that this activity was not from a (22Ne,xn) reaction, the researchers bombarded a 243Am target with 18O ions; reactions producing 256103 and 257103 showed very little SF activity (matching the established data), and the reaction producing heavier 258103 and 259103 produced no SF activity at all, in line with theoretical data. The researchers concluded that the activities observed came from SF of element 105.In April 1970, a team at Lawrence Berkeley Laboratory (LBL), in Berkeley, California, United States, claimed to have synthesized element 105 by bombarding californium-249 with nitrogen-15 ions, with an alpha activity of 9.1 MeV. To ensure this activity was not from a different reaction, the team attempted other reactions: bombarding 249Cf with 14N, Pb with 15N, and Hg with 15N. They stated no such activity was found in those reactions. The characteristics of the daughter nuclei matched those of 256103, implying that the parent nuclei were of 260105.

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