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Corby (crater) Corby is a crater approximately 6.6 km in diameter on the planet Mars, located at 42.88°N 137.56°E. The crater was named after the town of Corby, Northamptonshire, England, referred to in an Apollo 11 conversation. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37377717 | Corby (crater) |
Hyperconcentrated flow A hyperconcentrated flow is a two-phase flowing mixture of water and sediment in a channel which has properties intermediate between fluvial flow and debris flow. Large quantities of sand may be transported throughout the flow column, but the transport of suspended and bedload sediment along the channel depends on flow turbulence and high flow velocities, and coarser sediment remains as bedload. Hyperconcentrated flows do not show the characteristics of non-Newtonian flow typical of debris flows, e.g., levees, coarsening up or matrix supported deposits. Hyperconcentrated flows may contain anywhere from 5–60 % sediment by volume. Higher concentrations tend to be characteristic of debris flows, less of normal fluvial flow. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37396309 | Hyperconcentrated flow |
Suncup (snow) Suncups are bowl-shaped open depressions into a snow surface, normally wider than they are deep. They form closely packed, honeycomb, often hexagonal patterns with sharp narrow ridges separating smoothly concave hollows. For a given set of suncups, the hollows are normally all around the same size, meaning that the pattern is quasi-periodic on 20–80 cm scales. The depressions are typically 2–50 cm deep. Suncups form during the ablation (melting away) of snowy surfaces. It is thought they can form in a number of different ways | Natural_sciences | https://en.wikipedia.org/wiki?curid=37396683 | Suncup (snow) |
Suncup (snow) These include melting of clean snow by incident solar radiation in bright sunny conditions, but also during melting away of dirty snow under windy or overcast conditions, during which particles in the snow accumulate on the crests between hollows, insulating them. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37396683 | Suncup (snow) |
NGC 3738 is a dwarf galaxy in the constellation of Ursa Major and belongs to the M81 Group of galaxies. is 12 million light-years from the sun. The galaxy was first discovered by astronomer William Herschel in 1789. is a blue compact dwarf, which is small compared to large spiral galaxies. The galaxy is about 10,000 light-years across. It is one-tenth the size of the Milky Way Blue compact dwarf galaxies are blue in appearance because of the large cluster of hot massive stars. The galaxies are relatively dim and appear to be irregular in shape. They are typically chaotic in appearance. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37419951 | NGC 3738 |
Minchinbury Sandstone is a component of the Wianammatta Group of sedimentary rocks in the Sydney Basin of eastern Australia. Formed in the middle triassic period, this sandstone was structured by marine deposition as a set of sandy barrier islands at a coastal shoreline. The type locality of the formation is near the Great Western Highway in the suburb of Minchinbury in western Sydney. It is most often seen in the western parts of the city. Outcroppings are weak and not easily found, but it may be seen in places like road cuttings in localities from Epping, Grose Vale-Kurrajong, Kellyville, Rogans Hill, Bankstown, Pendle Hill, Bonnyrigg, Menangle, Duck River, Brownlow Hill and other sites. Thickness is between 1.5 and 6 metres, usually less than 3 metres | Natural_sciences | https://en.wikipedia.org/wiki?curid=37427195 | Minchinbury Sandstone |
Minchinbury Sandstone It comprises up to 70% quartz with calcite and volcanic lithic fragments. There is less feldspar and more calcite than the adjacent Bringelly Shale. Related to Greywacke, it comprises fine to medium-grained lithic sandstone. The Bringelly Shale lies above the Minchinbury Sandstone. Fossils are rare in this stratum, though plant fragments have been recorded. Sydney Basin, Hawkesbury sandstone, Bringelly Shale, Ashfield Shale, Wianamatta shale, Mittagong formation and Narrabeen Group. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37427195 | Minchinbury Sandstone |
Rezső Soó Károly von Bere (1 August 1903, Székelyudvarhely (now Odorheiu Secuiesc, Romania) – 10 February 1980, Budapest) was a Hungarian botanist and professor at the University of Budapest. He is best known for his work on: | Natural_sciences | https://en.wikipedia.org/wiki?curid=37427343 | Rezső Soó |
Parachlamydia Parachlamydia, is a genus of bacteriae belonging to the Chlamydiae. Species include "P. acanthamoeba". | Natural_sciences | https://en.wikipedia.org/wiki?curid=37462986 | Parachlamydia |
Simkania Simkania, is a genus of bacteria belonging to the Chlamydiae. The only species of this genus is "negevensis". | Natural_sciences | https://en.wikipedia.org/wiki?curid=37463002 | Simkania |
Snowden (physics) A Snowden is a unit of soft X-ray emissivity, equivalent to formula_1 ROSAT counts formula_2. These units were chosen by S. L. Snowden when working with the ROSAT mission to create the ROSAT All-Sky Survey in order to make the surface brightness values fit into a two byte integer. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37495763 | Snowden (physics) |
Terreneuvian The is the lowermost and oldest series of the Cambrian geological system. Its base is defined by the first appearance datum of the trace fossil "Treptichnus pedum" around million years ago. Its top is defined as the first appearance of trilobites in the stratigraphic record around million years ago. This series was formally ratified by the International Commission on Stratigraphy in 2012. The Fortunian stage and presently unnamed Cambrian Stage 2 are the stages within this series. The corresponds to the pre-trilobitic Cambrian. The name is derived from "Terre Neuve", a French name for the island of Newfoundland, Canada, where many rocks of this age are found, including the type section | Natural_sciences | https://en.wikipedia.org/wiki?curid=37496577 | Terreneuvian |
Terreneuvian The type locality (GSSP) of the is in Fortune Head, at the northern edge of the Burin Peninsula, Newfoundland, Canada (). The outcrops show a carbonate-siliciclastic succession which is mapped as the Chapel Island Formation. The formation is divided into the following members that are composed of peritidal sandstones and shales (Member 1), muddy deltaic and shelf sandstones and mudstones (Member 2A), laminated siltstones (Member 2B and 3) and mudstones and limestones of the inner shelf (Member 4). The Precambrian-Cambrian boundary lies 2.4 m above the base of the second member, which is the lowest occurrence of "Treptichnus pedum". The traces can be seen on the lower surface of the sandstone layers | Natural_sciences | https://en.wikipedia.org/wiki?curid=37496577 | Terreneuvian |
Terreneuvian The first calcareous shelled skeletal fossils "(Ladatheca cylindrica)" are 400 m above the boundary. The first trilobites appear 1400 m above the boundary, which corresponds to the beginning of the Branchian Series. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37496577 | Terreneuvian |
Foot per second squared The foot per second squared (plural "feet per second squared") is a unit of acceleration. It expresses change in velocity expressed in units of feet per second (ft/s) divided by time in seconds (s) (or the distance in feet (ft) traveled or displaced, divided by the time in seconds (s) squared). The corresponding unit in the International System of Units (SI) is the metre per second squared. Abbreviations include ft/s, ft/sec, ft/s/s, ft/sec/sec, and ft s. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37498558 | Foot per second squared |
Circumpolar deep water Circumpolar Deep Water (CDW) is a designation given to the water mass in the Pacific and Indian oceans that essentially characterizes a mixing of other water masses in the region. A distinguishing characteristic is the water is not formed at the surface, but rather by a blending of other water masses, including the North Atlantic Deep Water (NADW), the Antarctic Bottom Water (AABW), and the Pacific Intermediate Water masses. CDW, the greatest volume water mass in the Southern Ocean, is a mixture of NADW, AABW, and Antarctic Intermediate Water (AAIW), as well as recirculated deep water from the Indian and Pacific Oceans | Natural_sciences | https://en.wikipedia.org/wiki?curid=37516041 | Circumpolar deep water |
Circumpolar deep water Because the CDW is a mix of other water masses, its temperature-salinity (TS) profile is simply the point where the TS lines of the other water masses converge. TS diagrams refer to temperature and salinity profiles, which are one of the major ways water masses are distinguished from each other. The convergence of the TS lines thus proves the mixing of the other water masses. is between and has a salinity between 34.62 and 34.73 practical salinity units (PSU). In recent decades, hundreds of glaciers draining the Antarctic Peninsula (63° to 70°S) have undergone systematic and progressive change. These changes are widely attributed to rapid increases in regional surface air temperature, but it is now clear that this cannot be the sole driver | Natural_sciences | https://en.wikipedia.org/wiki?curid=37516041 | Circumpolar deep water |
Circumpolar deep water A strong correspondence has been discovered between mid-depth ocean temperatures and glacier-front changes along the approximately 1000-kilometer western coastline. In the south, glaciers that terminate in warm CDW have undergone considerable retreat, whereas those in the far northwest, which terminate in cooler waters, have not. Furthermore, a mid-ocean warming since the 1990s in the south is coincident with widespread acceleration of glacier retreat. The conclusion is that changes in ocean-induced melting are the primary cause of retreat for glaciers in this region. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37516041 | Circumpolar deep water |
Animals Are Like That Animals Are Like That! was Frank Buck’s sixth book, which continued his stories of capturing exotic animals. If you should find yourself with a monkey or ape on your hands and no knowledge of what to do with it, Buck tells co-author Carol Weld, just treat it like a child. And the elephant, like a man in the tropics, needs a sheltered siesta in mid-afternoon because he is susceptible to sunstroke. Monkeys pick up human ways and copy them. But you should never, never trust a tiger, any more than you should trust a crocodile. "Buck describes the animals in their native haunts, the capture of some of them, their characteristics, and their reactions in captivity...filled with adventure and odd bits of animal lore | Natural_sciences | https://en.wikipedia.org/wiki?curid=37517661 | Animals Are Like That |
Animals Are Like That " Booklist 36:170 Jan 1, 1940<br> "The vast legion of Frank Buck's followers will find "Animals Are Like That" thoroughly enjoyable and instructive reading. When the author doesn't know the answer to some more intangible animal trait he frankly admits his deficiency; but this happens infrequently. Mr. Buck has selected a large number of excellent illustrations..." Springfield Republican p10 Nov 29, 1939<br> "A fascinating study of animal traits." The Montreal Gazette - Dec 9, 1939 | Natural_sciences | https://en.wikipedia.org/wiki?curid=37517661 | Animals Are Like That |
Helicos single molecule fluorescent sequencing The Helicos Genetic Analysis System platform was the first commercial NGS (Next Generation Sequencing) implementation to use the principle of single molecule fluorescent sequencing, a method of identifying the exact sequence of a piece of DNA. It was marketed by the now defunct Helicos Biosciences. The fragments of DNA molecules are first hybridized in place on disposable glass flow cells. Fluorescent nucleotides are then added one-by-one, with a terminating nucleotide used to pause the process until an image has been captured. From the image, one nucleotide from each DNA sequence can be determined. The fluorescent molecule is then cut away, and the process is repeated until the fragments have been completely sequenced | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing This sequencing method and equipment were used to sequence the genome of the M13 bacteriophage. The Helicos Genetic Analysis System is capable of sequencing nucleic acids, from several nucleotides to several thousand nucleotides. However, the yield of sequences per unit mass is dependent on the number of 3’ end hydroxyl groups, and thus having relatively short templates for sequencing is more efficient than having long templates. Helicos recommends a length less than 1000nt (nucleotides), optimally about 100-200nt. Long fragments can be cleaved by shearing the DNA (the recommended approach), or restriction enzymes. Short fragments are removed to improve yield | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing DNA samples are hybridized to a primer immobilized on a flow cell for sequencing, so it is usually necessary to generate a nucleic acid with an end compatible for hybridization to those surfaces. The target sequence attached to the flow cell surface could, in theory, be any sequence which can be synthesized, but, in practice, the standard commercially available flow cell is oligo(dT)50. To be compatible with the oligo(dT)50 primer on the flow cell surface, it is necessary to generate a poly(dA) tail of at least 50 nt at the 3’ end of the molecule to be sequenced. Because the fill and lock step will fill in excess A’s but not excess T’s, it is desirable for the A tail to be at least as long as oligo(dT) on the surface | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing Generation of a 3’ poly(dA) tail can be accomplished with a variety of different ligases or polymerases. If there is sufficient DNA to measure both mass and average length, it is possible to determine the proper amount of dATP to be added to generate poly(dA) tails 90 to 200 nucleotides long. To generate tails of this length, it is first necessary to estimate how many 3’ ends there are in the sample and then use the right ratio of DNA, dATP, and terminal transferase to obtain the optimal size range of tails | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing If the tailed DNA targeted for sequencing is hybridized to the flow cell directly after tailing, it would have a free 3’ hydroxyl that could be extended in the sequencing reaction just like the surface-bound primer and potentially confuse the sequence determination. Thus, prior to sequencing, it is also necessary to block the 3’ ends of the molecules to be sequenced. Any 3’ end treatment that makes the molecule unsuitable for extension can be used. Typically, tailed molecules are blocked using terminal transferase and a dideoxynucleotide, but any treatment that leaves a 3’ phosphate or other modification that prevents extension can be similarly effective | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing The single molecule fluorescent sequencing is carried out on a glass flow cell with 25 channels for the same or different samples. The system can be run with either one or two flow cells at a time. In the standard configuration, each channel is equivalent and holds approximately 8 μl. Samples are generally loaded with higher volume (usually 20 μl or more) to ensure even hybridization along the length of the flow cell. Samples are inserted into the flow cell via the sample loader included with the overall system. Each channel is individually addressable, and sample is applied using a vacuum. Hybridization to the flow cell is typically carried out at 55◦C for 1 hr | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing Generally, samples for sequencing are prepared in such a way that the poly(A) tail is longer than the oligo(dT)50 on the surface of the flow cell. To avoid sequencing the unpaired A residues, a fill and lock treatment is needed. After hybridization, the temperature is lowered to 37◦C, and then dTTP and Virtual Terminator nucleotides corresponding to dATP, dCTP, and dGTP are added along with DNA polymerase. Virtual terminator nucleotides incorporate opposite the complementary base and prevent further incorporation because of the chemical structure appended to the nucleotide. Thus, all of the unpaired dAs present in the poly(A) tail are filled in with TTP | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing The hybridized molecule is locked in place when the polymerase encounters the first non-A residue and inserts the appropriate virtual terminator nucleotide. Because every DNA molecule should now have a dye attached, an image will include all molecules capable of nucleotide incorporation. Also, because the label could correspond to any base, no sequence information is obtained at this stage. Thus, for most molecules, sequencing commences with the second base of the original molecule. In order to sequence the hybridized DNAs, it is first necessary to cleave off the fluorescent dye and terminator moieties present on the virtual terminator nucleotides | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing The current generation of nucleotides is synthesized with a disulfide linkage that can be rapidly and completely cleaved. Following cleavage, the now-separated fluorescent dyes are washed away and then new polymerase and a single fluorescent nucleotide are added. After excitation of the fluorescent moiety by the system laser, another image is taken, and, on a standard sequencing run, this cyclic process is repeated 120 times. The number of sequencing cycles is user adjustable and can be modified depending on user needs for run time and length of read. During a standard run, two 25-channel flow cells are used, with each flow cell alternating between the chemistry cycle and the imaging cycle | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing During the imaging process, four lasers illuminate 1100 Fields of View (FOV) per channel with pictures taken by four CCD (Charge-coupled device) cameras via a confocal microscope. Though single molecules are visualized, multiple photon emissions are registered for each molecule, with the time spent at each FOV dependent on the brightness of the dye in the particular nucleotide as well as camera speed and detection efficiency. At the present time, the imaging process is the rate-determining step, and run time could be reduced at the expense of throughput by reducing the number of FOV per channel | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Helicos single molecule fluorescent sequencing Under optimal conditions, for a standard 120-cycle, 1100 field-of view run, 12,000,000 to 20,000,000 reads that are 25 nucleotides or longer and align to the reference genome should be expected from each channel, for a total of up to 1,000,000,000 aligned reads and 35 Gb of sequence from each run. A full run takes up to 8 days to complete. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37518608 | Helicos single molecule fluorescent sequencing |
Homoiohydry is the capacity of plants to regulate, or achieve homeostasis of, cell and tissue water content. evolved in land plants to a lesser or greater degree during their transition to land more than 500 million years ago, and is most highly developed in the vascular plants. It is the consequence of a suite of morphological innovations and strategies that enable plant shoots exploring aerial environments to conserve water by internalising the gas exchange surfaces, enclosing them in a waterproof membrane and providing a variable aperture control mechanism, the stomatal guard cells, which regulate the rates of water transpiration and CO exchange | Natural_sciences | https://en.wikipedia.org/wiki?curid=37521969 | Homoiohydry |
Homoiohydry In vascular plants, water is acquired from the soil by roots and transported via the xylem to aerial portions of the plant. Water evaporation from the aerial surfaces of the plant is controlled by a waterproof covering of cuticle. Gas exchange with the atmosphere is controlled by stomata, which can open and close to control water loss, and diffusion of carbon dioxide to the chloroplasts takes place in intercellular spaces between chlorenchyma cells in the stem or in the mesophyll tissue of the leaf. The antonym of homoiohydry is poikilohydry, a condition in which plant water content is passively reduced or increased in equilibrium with environmental water status. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37521969 | Homoiohydry |
Scalindua brodae "Candidatus Scalindua brodae" is a bacterial member of the order Planctomycetes and therefore lacks peptidoglycan in its cell wall, has a compartmentalized cytoplasm. It is an ammonium oxidising bacteria. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37521998 | Scalindua brodae |
Fortunian The age marks the beginning of the Phanerozoic eon, the Paleozoic era, and the Cambrian period. It is the first of the two stages of the Terreneuvian series. Its base is defined as the first appearance of the trace fossil "Treptichnus pedum" million years ago. The top of the which is the base of the Stage 2 of the Cambrian has not been formally defined yet, but will correspond to the appearance of an Archeocyatha species or "Small shelly fossils" approximately million years ago. The name is derived from a part of the Burin Peninsula, the town of Fortune near the GSSP and Fortune Bay. The type locality (GSSP) of the stage is in Fortune Head, at the northern edge of the Burin Peninsula, Newfoundland, Canada () | Natural_sciences | https://en.wikipedia.org/wiki?curid=37526413 | Fortunian |
Fortunian This GSSP coincides with the base of the Terreneuvian series, the Precambrian-Cambrian boundary and the beginning of the Phanerozoic. The outcrops show a carbonate-siliciclastic succession which is mapped as the Chapel Island Formation. The formation is divided into the following members that are composed of peritidal sandstones and shales (Member 1), muddy deltaic and shelf sandstones and mudstones (Member 2A), laminated siltstones (Member 2B and 3) and mudstones and limestones of the inner shelf (Member 4). The Precambrian-Cambrian boundary lies 2.4 m above the base of the 2nd member which is the lowest occurrence of "Treptichnus pedum". The traces can be seen on the lower surface of the sandstone layers | Natural_sciences | https://en.wikipedia.org/wiki?curid=37526413 | Fortunian |
Fortunian The first calcareous shelled skeletal fossils "(Ladatheca cylindrica)" is 400 m above the boundary. The first trilobites appear 1400 m above the boundary which corresponds to the beginning of the Branchian Series. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37526413 | Fortunian |
Plebanski tensor The is an order 4 tensor in general relativity constructed from the trace-free Ricci tensor. It was first defined by Jerzy Plebański in 1964. Let formula_1 be the trace-free Ricci tensor: Then the is defined as The advantage of the is that it shares the same symmetries as the Weyl tensor. It therefore becomes possible to classify different spacetimes based on additional algebraic symmetries of the in a manner analogous to the Petrov classification. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37528165 | Plebanski tensor |
Amalgamated zinc is zinc that has been surface treated with mercury to form a surface amalgam containing little contamination from other elements. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37532121 | Amalgamated zinc |
Big Brake The is a theoretical scientific model suggested as one of the possibilities for ultimate fate of the universe. In this model the effect of dark energy reverses, stopping the accelerating expansion of the Universe, and causing an infinite rate of deceleration. All cosmic matter would be subjected to extreme tidal forces and be destroyed. Another possibility is matter may still exist, albeit in a different form and organization. The consequences for time are also unclear. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37541861 | Big Brake |
Metallicity distribution function The metallicity distribution function is an important concept in stellar and galactic evolution. It is a curve of what proportion of stars have a particular metallicity ([Fe/H], the relative abundance of iron and hydrogen) of a population of stars such as in a cluster or galaxy. MDFs are used to test different theories of galactic evolution. Much of the iron in a star will have come from earlier type Ia supernovae. Other [alpha] metals can be produced in core collapse supernovae. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37555875 | Metallicity distribution function |
Ájtte Ájtte, the Swedish Mountain and Sami Museum (), is a cultural and natural history museum in Jokkmokk in Lapland, Sweden. is a museum, which specializes in the culture and nature of the mountainous area of Northern Sweden, and which is also the main museum and archive for the Sami culture of Sweden. is also an information centre for tourism in Lapland. The word "ájtte" is a Lule Sami language one, meaning storage hut and referring to the museum as an archive for artifacts of the Sami cultural heritage. was inaugurated in June 1989 and has a staff of about 25 employees | Natural_sciences | https://en.wikipedia.org/wiki?curid=37564976 | Ájtte |
Ájtte The museum is owned and managed by a foundation, which was established in 1983 by the Swedish Government, the Norrbotten Region, the Jokkmokk Municipality and the two national Sami organizations Svenska Samernas Riksförbund (National Union of Swedish Sami people) and Same Ätnam (Sami land). According to an agreement on financing of the museum, which was entered into the same year, the Government bodies commit themselves to a long term financial contribution to the museum. Such funds are the result of a court decision regarding compensation after rivers in Lapland have been exploited for electric power generation. The Swedish government appoints the chairman and three of the members of the board of the foundation | Natural_sciences | https://en.wikipedia.org/wiki?curid=37564976 | Ájtte |
Ájtte Thus, government funds cover around half of the current budget of the museum. Since 1995 has established an alpine botanical garden at the valley of Kvarnbäcken in Jokkmokk with plants from different environments of the mountain range of Northern Scandinavia. One of the century-old researcher cottages from Sarek National Park, designed and used by the pioneering scientist Axel Hamberg, has been dismantled and moved from Sarek and reerected in the botanical garden. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37564976 | Ájtte |
Protein Local Optimization Program (PLOP) is computer software, a molecular dynamics simulation package written in the programming language Fortran. It was developed originally by Matthew P. Jacobson and Richard A. Friesner of the Friesner lab at Columbia University, and then moved to the Jacobson lab at University of California, San Francisco (UCSF), and Schrödinger, LLC. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37572978 | Protein Local Optimization Program |
Ladeana Hillier is a biomedical engineer and computational biologist. She was one of the earliest scientists involved in the Human Genome Project and is noted for her work in various branches of DNA sequencing, as well as for having co-developed Phred, a widely used DNA trace analyzer. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37573969 | Ladeana Hillier |
Aphlebia Aphlebiae are the imperfect or irregular leaf endings commonly found on ferns and fossils of ferns from the Carboniferous Period, but seem to have disappeared by the beginning of the Mesozoic. According to the United States Geological Survey in 1983, “The discovery in recent years of Aplebiæ attached to the rachis of many species of "Pecpteris" and "Sphenopteris", such as "P. dentata", "P. Biotii, P. abbrebiata, and Sphenopteris cremate" strengthens the view now generally entertained, that most of the species of are stipal abortive pinnæ growing from the bases of primary or secondary rachises” (101). The word itself is derived from the Greek "phleb-", meaning vein, and "a-", meaning without. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37575385 | Aphlebia |
Aquiherbosa An aquiherbosa is a plant community of herbaceous plants that exists in abundantly wet areas. This can refer to plant communities in wetlands, ponds, or other bodies of water. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37575487 | Aquiherbosa |
Nuummite is a rare metamorphic rock that consists of the amphibole minerals gedrite and anthophyllite. It is named after the area of Nuuk in Greenland, where it was found. is usually black in colour and opaque. It consists of two amphiboles, gedrite and anthophyllite, which form exsolution lamellae that give the rock its typical iridescence. Other common minerals in the rock are pyrite, pyrrhotite and chalcopyrite, which form shimmering yellow bands in polished specimens. In Greenland the rock was formed by two consecutive metamorphic overprints of an originally igneous rock. The intrusion took place in the Archean around 2800 million years ago and the metamorphic overprint was dated at 2700 and 2500 million years ago | Natural_sciences | https://en.wikipedia.org/wiki?curid=37579789 | Nuummite |
Nuummite The rock was first discovered in 1810 in Greenland by the mineralogist K. L. Giesecke. Due to its iridescent nature, this rare stone is sought after by gemstone dealers, collectors and those interested in the esoteric. It is often sold with tumble finishing. In 2009, a new Variety of Nuumite was discovered in central Mauritania. Under its unofficial name Jenakite, this Variety is distinctive due to the presence and high density of blue and green Anthophyllite needle-like crystals. Nuumite from Greenland has no blue or green Anthophyllite needle-like crystals. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37579789 | Nuummite |
Fuel factor The fuel factor, f, is the ratio of created CO to depleted oxygen in a combustion reaction, used to check the accuracy of an emission measurement system. It can be calculated using the equation Where %O is the percent O by volume, dry basis, %CO is the percent CO by volume, dry basis, and 20.9 is the percent O by volume in ambient air. The can be corrected for the amount of CO, by adding the percent CO on a dry basis to the CO, and subtracting half of the percent CO from the O. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37591765 | Fuel factor |
Cardiovirus B is a species in the genus "Cardiovirus" and is represented by two isolates, Saffold virus (SAFV) and Theiler's murine encephalomyelitis virus (TMEV). | Natural_sciences | https://en.wikipedia.org/wiki?curid=37596367 | Cardiovirus B |
Colloidal probe technique The colloidal probe technique is commonly used to measure interaction forces acting between colloidal particles and/or planar surfaces in air or in solution. This technique relies on the use of an atomic force microscope (AFM). However, instead of a cantilever with a sharp AFM tip, one uses the "colloidal probe". The colloidal probe consists of a colloidal particle of few micrometers in diameter that is attached to an AFM cantilever. The colloidal probe technique can be used in the "sphere-plane" or "sphere-sphere" geometries ("see figure"). One typically achieves a force resolution between 1 and 100 pN and a distance resolution between 0.5 and 2 nm. The colloidal probe technique has been developed in 1991 independently by Ducker and Butt | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique Since its development this tool has gained wide popularity in numerous research laboratories, and numerous reviews are available in the scientific literature. Alternative techniques to measure force between surfaces involve the surface forces apparatus, total internal reflection microscopy, and optical tweezers techniques to with video microscopy. The possibility to measure forces involving particles and surfaces directly is essential since such forces are relevant in a variety of processes involving colloidal and polymeric systems. Examples include particle aggregation, suspension rheology, particle deposition, and adhesion processes. One can equally study similar biological phenomena, such as deposition of bacteria or the infection of cells by viruses | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique Forces are equally most informative to investigate the mechanical properties of interfaces, bubbles, capsules, membranes, or cell walls. Such measurements permit to make conclusions about the elastic or plastic deformation or eventual rupture in such systems. The colloidal probe technique provides a versatile tool to measure such forces between a colloidal particle and a planar substrate or between two colloidal particles (see figure above). The particles used in such experiments have typically a diameter between 1–10 μm. Typical applications involve measurements of electrical double layer forces and the corresponding surface potentials or surface charge, van der Waals forces, or forces induced by adsorbed polymers | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique The colloidal probe technique uses a standard AFM for the force measurements. But instead the AFM cantilever with an attached sharp tip one uses the "colloidal probe". This colloidal probe is normally obtained by attaching a colloidal particle to a cantilever. By recording the deflection of the cantilever as a function of the vertical displacement of the AFM scanner one can extract the force acting between the probe and the surface as a function of the surface separation. This type of AFM operation is referred to as the "force mode". With this probe, one can study interactions between various surfaces and probe particles in the "sphere-plane geometry" | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique It is also possible to study forces between colloidal particles by attaching another particle to the substrate and perform the measurement in the "sphere-sphere geometry", see figure above. The force mode used in the colloidal probe technique is illustrated in the figure on the left. The scanner is fabricated from piezoelectric crystals, which enable its positioning with a precision better than 0.1 nm. The scanner is lifted towards the probe and thereby one records the scanner displacement "D". At the same time, the deflection of the cantilever "ξ" is monitored as well, typically with a comparable precision | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique One measures the deflection by focusing a light beam originating from a non-coherent laser diode to the back of the cantilever and detecting the reflected beam with a split photodiode. The lever signal "S" represents the difference in the photocurrents originating from the two halves of the diode. The lever signal is therefore proportional to the deflection "ξ". During an approach-retraction cycle, one records the lever signal "S" as a function of the vertical displacement "D" of the scanner. Suppose for the moment that the probe and the substrate are hard and non-deformable objects and that no forces are acting between them when they are not in contact. In such a situation, one refers to a "hard-core repulsion" | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique The cantilever will thus not deform as long not being in contact with the substrate. When the cantilever touches the substrate, its deflection will be the same as the displacement of the substrate. This response is referred to as the "constant compliance" or contact region. The lever signal "S" as a function of the scanner displacement "D" is shown in the figure below. This graph consists of two straight lines resembling a hockey-stick. When the surfaces are not in contact, the lever signal will be denoted as "S". This value corresponds to the non-deformed lever | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique In the constant compliance region, the lever signal is simply a linear function of the displacement, and can be represented as a straight line The parameters "a" and "b" can be obtained from a least-squares fit of the constant compliance region. The inverse slope "a" is also referred to as the optical lever sensitivity. By inverting this relation for the lever signal "S", which corresponds to the non-deformed lever, one can accurately obtain the contact point from "D" = ("S" − "b")/"a". Depending on the substrate, the precision in determining this contact point is between 0.5–2 nm. In the constant compliance region, the lever deformation is given by In this fashion, one can detect deflections of the cantilever with typical resolution of better than 0.1 nm | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique Let us now consider the relevant situation where the probe and the substrate interact. Let us denote by "F"("h") the force between the probe and the substrate. This force depends on the surface separation "h". In equilibrium, this force is compensated by the restoring force of the spring, which is given by the Hooke's law where "k" is the spring constant of the cantilever. Typical spring constants of AFM cantilevers are in the range of 0.1−10 N/m. Since the deflection is monitored with a precision better 0.1 nm, one typically obtains a force resolution of 1−100 pN. The separation distance can be obtained from the displacement of the scanner and the cantilever deflection Figure below illustrates how the cantilever responds to different force profiles | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique In the case of a soft repulsive force, the cantilever is repelled from the surface and only slowly approaches the constant compliance region. In such situations, it might be actually difficult to identify this region correctly. When the force is attractive, the cantilever is attracted to the surface and may become unstable. From stability considerations one finds that the cantilever will be unstable provided This instability is illustrated in the right panel of the figure on the right. As the cantilever approaches, the slope of the force curve increases. When the slope becomes larger than the spring constant of the cantilever, the cantilever jumps into contact when the slope of the force curve exceeds the force constant of the cantilever | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique Upon retraction, the same phenomenon happens, but the point where the cantilever jumps out is reached at a smaller separation. Upon approach and retraction, the system will show a hysteresis. In such situations, a part of the force profile cannot be probed. However, this problem can be avoided by using a stiffer cantilever, albeit at the expense of an inferior force resolution. The colloidal probes are normally fabricated by gluing a colloidal particle to a tip-less cantilever with a micromanipulator in air. The subsequent rewetting of the probe may lead to the formation of nanosized bubbles on the probe surface | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique This problem can be avoided by attaching the colloidal particles under wet conditions in AFM fluid cell to appropriately functionalized cantilevers. While the colloidal probe technique is mostly utilized in the sphere-plane geometry, it can be also used in the sphere-sphere geometry. The latter geometry further requires a lateral centering of the two particles, which can be either achieved with an optical microscope or an AFM scan. The results obtained in these two different geometries can be related with the Derjaguin approximation. The force measurements rely on an accurate value of the spring constant of the cantilever. This spring constant can be measured by different techniques | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique The "thermal noise" method is the simplest to use, as it is implemented on most AFMs. This approach relies on the determination of the mean square amplitude of the cantilever displacement due to spontaneous thermal fluctuations. This quantity is related to the spring constant by means of the equipartition theorem. In the "added mass method" one attaches a series of metal beads to the cantilever and each case one determines the resonance frequency. By exploiting the relation for a harmonic oscillator between the resonance frequency and the mass added one can evaluate the spring constant as well. The "frictional force method" relies on measurement of the approach and retract curves of the cantilever through a viscous fluid | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique Since the hydrodynamic drag of a sphere close to a planar substrate is known theoretically, the spring constant of the cantilever can be deduced. The "geometrical method" exploits relations between the geometry of the cantilever and its elastic properties. The separation is normally measured from the onset of the constant compliance region. While the relative surface separation can be determined with a resolution of 0.1 nm or better, the absolute surface separation is obtained from the onset of the constant compliance region. While this onset can be determined for solid samples with a precision between 0.5–2 nm, the location of this onset can be problematic for soft repulsive interactions and for deformable surfaces | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique For this reason, techniques have been developed to measure the surface separation independently (e.g., total internal reflection microscopy, reflection interference contrast microscopy). By scanning the sample with the colloidal probe laterally permits to exploit friction forces between the probe and the substrate. Since this technique exploits the torsion of the cantilever, to obtain quantitative data the torsional spring constant of the cantilever must be determined. A related technique involving similar type of force measurements with the AFM is the single molecular force spectroscopy. However, this technique uses a regular AFM tip to which a single polymer molecule is attached | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Colloidal probe technique From the retraction part of the force curve, one can obtain information about stretching of the polymer or its peeling from the surface. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37605500 | Colloidal probe technique |
Anton Eleutherius Sauter (18 April 1800 in Grossarl – 1881 in Salzburg) was an Austrian physician and botanist. From 1820 to 1826 he studied medicine at the University of Vienna, where one of his instructors was Joseph Franz von Jacquin. After graduation, he worked as a physician at several locations in Austria. In 1840 he settled as a physician in Steyr, then from 1848 to 1871, served as a regional and district doctor in Salzburg. He is largely known for his investigations of flora native to Land Salzburg. From 1866 to 1879 he published in seven volumes, ""Flora des Herzogthums Salzburg"" (Flora of the Duchy of Salzburg}. In 1860 he was co-founder of the "Gesellschaft für Salzburger Landeskunde" (board member, 1864-74) | Natural_sciences | https://en.wikipedia.org/wiki?curid=37611255 | Anton Eleutherius Sauter |
Anton Eleutherius Sauter Numerous taxa with the specific epithet of "sauteri" are named after him, an example being "Draba sauteri". | Natural_sciences | https://en.wikipedia.org/wiki?curid=37611255 | Anton Eleutherius Sauter |
Ping Tao Li (; born 1936) is a Chinese botanist who co-authored articles in the "Flora of China". | Natural_sciences | https://en.wikipedia.org/wiki?curid=37618233 | Ping Tao Li |
Jiangshanian The is the middle stage of the Furongian series. It follows the Paibian stage and is succeeded by the still unnamed Stage 10 of the Cambrian. The base is defined as the first appearance of the trilobite "Agnostotes orientalis" which is estimated to be million years ago. The lasted until approximately million years ago. The Cambrian stage was named after Jiangshan, a city in China's Zhejiang province. The GSSP of the is the "Duibian B Section" (), west of the village of Duibian, and 10 km north of Jiangshan. The outcrop belongs to the Huayansi Formation. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37618721 | Jiangshanian |
Guzhangian The is an uppermost stage of the Miaolingian Series of the Cambrian. It follows the Drumian Stage and precedes the Paibian Stage of the Furongian Series. The base is defined as the first appearance of the trilobite "Lejopyge laevigata" around million years ago. The Guzhangian-Paibian boundary is marked by the first appearance of the trilobite "Glyptagnostus reticulatus" around million years ago. The name is derived from Guzhang County in Hunan Province of China. The GSSP is defined in the Huaqiao Formation in Hunan, China. The precise base of the is a limestone layer 121.3 m above the base Huaqiao Formation at the Louyixi section (), where "Lejopyge laevigata" has its first appearance. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37620670 | Guzhangian |
Drumian The is a stage of the Miaolingian Series of the Cambrian. It succeeds the Wuliuan and precedes the Guzhangian. The base is defined as the first appearance of the trilobite "Ptychagnostus atavus" around million years ago. The top is defined as the first appearance of another trilobite "Lejopyge laevigata" around million years ago. The GSSP is defined in the "section" () in the Drum Mountains, Millard County, Utah, United States. The stage was also named after the Drum Mountains. The section is an outcrop of the Wheeler Formation, a succession of calcareous shales. The precise base of the is a laminated limestone above the base of the Wheeler Formation. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37620824 | Drumian |
Quantasome Quantasomes are particles found in the thylakoid membrane of chloroplasts in which photosynthesis takes place. They are embedded in a paracrystalline array on the surface of thylakoid discs in chloroplasts. They are composed of lipids and proteins that include various photosynthetic pigments and redox carriers. For this reason they are considered to be photosynthetic units. They occur in 2 sizes: the smaller quantasome is thought to represent the site of photosystem I, the larger to represent the site of photosystem II. Quantasomes were first identified by Roderic B. Park in 1962. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37630226 | Quantasome |
Edison Volta Prize The is awarded biennially by the European Physical Society (EPS) to individuals or groups of up to three people in recognition of outstanding achievements in physics. The award consists of a diploma, a medal, and 10,000 euros in prize money. The award has been established in 2012 by the Centro di Cultura Scientifica "Alessandro Volta", Edison S.p.A and the European Physical Society | Natural_sciences | https://en.wikipedia.org/wiki?curid=37641022 | Edison Volta Prize |
Edison Volta Prize The 2018 EPS was awarded to : for "for the development, in their respective countries, of key technologies and innovative experimental solutions, that enabled the advanced interferometric gravitational wave detectors LIGO and Virgo to detect the first gravitational wave signals from mergers of Black Holes and of Neutron Stars" 2016 - The 2016 EPS was awarded to for "seminal contributions to optical science, to the field of single-molecule spectroscopy and imaging (first single molecule detection by fluorescence and first optical detection of magnetic resonance in single molecule) and for pioneering investigations into the photoblinking and photobleaching behaviors of individual molecules at the heart of many current optical super-resolution experiments | Natural_sciences | https://en.wikipedia.org/wiki?curid=37641022 | Edison Volta Prize |
Edison Volta Prize " The 2015 EPS has been awarded to the three principal scientific leaders of the European Space Agency’s (ESA) Planck Mission: "for directing the development of the Planck payload and the analysis of its data, resulting in the refinement of our knowledge of the temperature fluctuations in the Cosmic Microwave Background as a vastly improved tool for doing precision cosmology at unprecedented levels of accuracy, and consolidating our understanding of the very early universe | Natural_sciences | https://en.wikipedia.org/wiki?curid=37641022 | Edison Volta Prize |
Edison Volta Prize " 2014 EPS was awarded to: "for seminal contribution to physics (that) have paved the way for novel explorations of quantum mechanics and have opened new routes in quantum information processing" 2012 EPS was awarded 12 November 2012 to: "for having led, building on decades of dedicated work by their predecessors, the culminating efforts in the direction, research and operation of the CERN Large Hadron Collider (LHC), which resulted in many significant advances in high energy particle physics, in particular, the first evidence of a Higgs-like boson in July 2012". | Natural_sciences | https://en.wikipedia.org/wiki?curid=37641022 | Edison Volta Prize |
Misty Montes The are a range of mountains on Titan, the largest moon of the planet Saturn. The range is located in the northern hemisphere of Titan, between 56-7° north and 61-3° west. The are named after the Misty Mountains, a range of mountains in J. R. R. Tolkien's fictional world of Middle Earth which appears most prominently in "The Hobbit". The name follows a convention that Titanean mountains are named after mountains in Tolkien's work. It was formally announced on November 13, 2012. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642169 | Misty Montes |
Irensaga Montes The is a range of mountains on Titan, the largest moon of the planet Saturn. The range is located near Titan's equator, between 5-6° south and 210-214° east. It is located within the Adiri region, just west of the landing site of the Huygens probe. The is named after Irensaga, one of the White Mountains in J. R. R. Tolkien's fictional world of Middle-earth. The name follows a convention that Titanean mountains are after mountains in Tolkien's work. It was formally announced on November 13, 2012. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642238 | Irensaga Montes |
Mindolluin Montes The are a range of mountains on Titan, the largest moon of the planet Saturn. The range is located near Titan's equator, between 1-4° south and 205-213° east. It is located within the Adiri region, just west of the landing site of the Huygens probe. The are named after Mindolluin, one of the White Mountains in J. R. R. Tolkien's fictional world of Middle-earth. The name follows a convention that Titanean mountains are after mountains in Tolkien's work. It was formally announced on November 13, 2012. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642273 | Mindolluin Montes |
Mithrim Montes The are a range of mountains on Titan, the largest moon of the planet Saturn. The range is located near Titan's equator, between 1-3° south and 126-8° west and consists of three parallel ridges that are oriented east-west, spaced about 25 km apart. They are located within the region Xanadu. The highest peak is about high and is located on the southernmost of the ridges; it is the highest known peak on Titan. The are named after the Mithrim Mountains, a range in J. R. R. Tolkien's fictional world of Middle-earth. This follows a convention that Titanean mountains are named after mountains in Tolkien's work. The name was formally announced on November 13, 2012. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642334 | Mithrim Montes |
Taniquetil Montes The are a range of mountains on Titan, the largest moon of the planet Saturn. The range is located near Titan's equator, between 2-4° south and 211-214° west. It is located within the Adiri region, just west of the landing site of the Huygens probe. The are named after Taniquetil, a mountain in the Undying Lands in J. R. R. Tolkien's fictional universe. The name follows a convention that Titanean mountains are named after mountains in Tolkien's work. It was formally announced on November 13, 2012. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642368 | Taniquetil Montes |
Erebor Mons is a mountain on Titan, the largest moon of the planet Saturn. It is located near Titan's equator, between 4-5° south and 35-36° west, centered on , in the western part of Quivira region. It is 40 km across, more than 1 km high and has lobate flow features to its north and east. It is probably a cryovolcano. is situated about 470 km to the north-northeast of a larger cryovolcanic construct, Doom Mons. is one of the highest known mountains of Titan, but it is not readily discernible on radar or infrared images. It was discovered only when stereoscopic radar data allowed construction of an elevation map. It was imaged by Cassini radar 22 February and 10 April 2007. is named after Erebor, the "Lonely Mountain" that appears in J. R. R | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642436 | Erebor Mons |
Erebor Mons Tolkien's fictional world of Middle-earth, most prominently in "The Hobbit". The name follows a convention that Titanean mountains are named after mountains in Tolkien's work. The name was formally announced on November 13, 2012. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642436 | Erebor Mons |
Arrakis Planitia is a planitia (plain) on Titan, the largest moon of the planet Saturn. It is located in Titan's southern hemisphere, between 74-80° south and 113-134° east, within the Mezzoramia region. is named after Arrakis, a fictional desert planet that is featured prominently in Frank Herbert's "Dune" novels. The name follows a convention that Titanean plains are named after planets in Herbert's work. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37642502 | Arrakis Planitia |
Substellar companion is a generic term for an astronomical body orbiting a star. It can describe a celestial bodies too small to be a star, but too big to be called a planet. Alternatively, it is a substellar object such as exoplanet or brown dwarf that is orbiting a star. Objects as low as 8-23 Jupiter masses have been called a substellar companion. Objects orbiting a star are often called a planet below 13 Jupiter masses and brown dwarf above that. Companions at that planet-brown dwarf borderline have been called Super-Jupiters, such around the star Kappa Andromedae. Nevertheless, objects as small as 8 Jupiter masses have been called a brown dwarf. A substellar companion is thought to exist in the binary star system SDSS 1212 | Natural_sciences | https://en.wikipedia.org/wiki?curid=37643310 | Substellar companion |
Substellar companion Substellar companions have been confirmed by analyzing astrometric data from Hipparcos. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37643310 | Substellar companion |
Cooperative luminescence and cooperative absorption Cooperative luminescence is the radiative process in which two excited ions simultaneously make downward transition to emit one photon with the sum of their excitation energies. The inverse process is cooperative absorption, in which a photon can be absorbed by a coupled pair of two ions, making them excited simultaneously. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37648306 | Cooperative luminescence and cooperative absorption |
Adaptive Coloration in Animals is a 500-page textbook about camouflage, warning coloration and mimicry by the Cambridge zoologist Hugh Cott, first published during the Second World War in 1940; the book sold widely and made him famous. The book's general method is to present a wide range of examples from across the animal kingdom of each type of coloration, including marine invertebrates and fishes as well as terrestrial insects, amphibians, reptiles, birds and mammals. The examples are supported by many of Cott's own drawings, diagrams, and photographs. This essentially descriptive natural history treatment is supplemented with accounts of experiments by Cott and others | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals The book had few precedents, but to some extent follows (and criticises) Abbott Handerson Thayer's 1909 "Concealing-Coloration in the Animal Kingdom". The book is divided into three parts: concealment, advertisement, and disguise. Part 1, concealment, covers the methods of camouflage, which are colour resemblance, countershading, disruptive coloration, and shadow elimination. The effectiveness of these, arguments for and against them, and experimental evidence, are described. Part 2, advertisement, covers the methods of becoming conspicuous, especially for warning displays in aposematic animals. Examples are chosen from mammals, insects, reptiles and marine animals, and empirical evidence from feeding experiments with toads is presented | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals Part 3, disguise, covers methods of mimicry that provide camouflage, as when animals resemble leaves or twigs, and markings and displays that help to deflect attack or to deceive predators with deimatic displays. Both Batesian mimicry and Müllerian mimicry are treated as adaptive resemblance, much like camouflage, while a chapter is devoted to the mimicry and behaviour of the cuckoo. The concluding chapter admits that the book's force is cumulative, consisting of many small steps of reasoning, and being a wartime book, compares animal to military camouflage. Cott's textbook was at once well received, being admired both by zoologists and naturalists and among allied soldiers. Many officers carried a copy of the book with them in the field | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals Since the war it has formed the basis for experimental investigation of camouflage, while its breadth of coverage and accuracy have ensured that it remains frequently cited in scientific papers. "Adaptive Coloration in Animals" is a 500-page book, in its first edition. It was published by Methuen (in London) and Oxford University Press (in New York) in 1940. It is full of detailed observations of types of camouflage and other uses of colour in animals, and illustrated by the author with clear drawings and photographs. There is a coloured frontispiece showing eight of Cott's paintings of tropical amphibians. The book has 48 monotone plates and several illustrations | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals Cott's method is to provide a large number of examples, illustrated with his own drawings or photographs, showing animals from different groups including fish, reptiles, birds and insects, especially butterflies. The examples are chosen to illustrate specific adaptations. For example, the fish "Chaetodon capistratus" is described as follows: Cott was well aware that he was publishing in wartime. There are, as Julian Huxley remarks in his 'Introduction', references throughout the book to the human analogues of animal camouflage and concealment | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals For example, in the section on 'Adaptive Silence', the kestrel is said to "practise dive-bombing attacks", or "after the fashion of a fighter 'plane" to fly down other birds, while "Owls have solved the problem of the silent air-raid"; Cott spends the rest of that paragraph on the "method which has recently been rediscovered and put into practice" of shutting off a bomber's engines and "gliding noiselessly down towards their victims" at Barcelona in the Spanish Civil War. In the concluding chapter, Cott explicitly states "The innumerable visible devices used ... in peacetime and in wartime ... are merely rediscovered ... applications of colour that have already reached a high ... degree of specialization and perfection. | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals in the animal world", mentioning predator-prey relationships, sexual selection and signalling to rivals. He then compares the "hunting disguises put on ... as a means of approaching, ambushing or alluring game, and the sniping suits, concealed machine-gun posts, and booby traps" with the camouflage of animal predators; and similarly he compares "protective disguises" with the "photographer's hide and the gunner's observation post." In the same section, Cott compares intentionally visible signs with animal warning colours: "The policeman's white gloves have their parallel in the white stripes or spots of nocturnal skunks and carabids | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals The Automobile Association has adopted a system of coloration <nowiki>[black and yellow]</nowiki> whose copyright belongs by priority to wasps and salamanders." The book addresses its subject under three main headings: concealment, advertisement, and disguise. Cott sets out his view that we have to be re-taught how to see, mentioning Ruskin's "innocence of the eye". He argues that camouflage should, and in animals actually does, use four mechanisms: colour resemblance, obliterative shading (i.e. countershading, the graded shading which conceals self-shadowing of the lower body), disruptive coloration, and shadow elimination. Chapter 1. General colour resemblance. Chapter 2. Variable colour resemblance | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals Caterpillars and pupae (as in Poulton's famous experiment) are coloured to match their environment. Mountain hares change colour in winter; many fish, cephalopods, frogs, and crustacea can change colour rapidly. Chapter 3. Obliterative shading. Chapter 4. Disruptive coloration. Cott goes on to explain that the right-hand drawing shows the effect "of broken surroundings in further blending and confusing the picture", observing that this is the closest to what is seen in nature. His readers are invited to look first at the right-hand images to gain an idea of the power of "these optical devices" as camouflage, putting off the moment when the animal is actually recognised. Chapter 5. Coincident disruptive coloration. Chapter 6. Concealment Of the shadow | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |
Adaptive Coloration in Animals Chapter 7. Concealment in defence, mainly as illustrated by birds. Chapter 8. Concealment In offence. Chapter 9. Objections and evidence bearing on the theory of concealing coloration. Chapter 10. The effectiveness of concealing coloration. Chapter 1. The appearance and behaviour of aposematic animals. Chapter 2. Warning displays. Chapter 3. Adventitious warning coloration. Chapter 4. The nature and function of warning coloration, as illustrated by the mammalia. Chapter 5. The Protective Attributes Of Aposematic Animals In General. Chapter 6. The relation between warning colours and distasteful attributes. Chapter 7. The effectiveness of protective attributes associated with warning colours. Chapter 8 | Natural_sciences | https://en.wikipedia.org/wiki?curid=37658639 | Adaptive Coloration in Animals |