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Gel point (petroleum) Gel point is the temperature at which diesel or biodiesel fuel freezes solid and can no longer flow by gravity or be pumped through fuel lines. This phenomenon happens when a fuel reaches a low enough temperature whereby enough wax crystals have formed to prevent any movement in the oil. For #2 diesel this is usually around . For the fuel to become pumpable again, it needs to be brought above the gel point temperature to the Ungel point, which is typically near its pour point. However, most of the waxes will still remain in solid form and the fuel has to be warmed up further until its Remix temperature in order to completely remelt and redissolve the waxes. Anti-gel additives are therefore commonly added to diesel or biodiesels where cold temperature is expected. They act to reduce the formation of wax crystals in the fuel, thereby lowering the pour point and the gel point of the fuel. Anti-gel additives may not necessarily affect the cloud point. | https://en.wikipedia.org/wiki?curid=16371070 |
Sun-Earth Day is a joint educational program established in 2000 by NASA and ESA. The goal of the program is to popularize the knowledge about the Sun, and the way it influences life on Earth, among students and the public. The day itself is mainly celebrated in the United States near the time of the spring equinox. However, the event actually runs throughout the year, with a different theme being chosen each year. The selection of each year's theme often corresponds to events for that year. Every theme is supported by free educational plans for both informal and formal educators. Here is a list of themes by year: | https://en.wikipedia.org/wiki?curid=16379875 |
Nonequilibrium partition identity The nonequilibrium partition identity (NPI) is a remarkably simple and elegant consequence of the fluctuation theorem previously known as the Kawasaki identity: (Carberry et al. 2004). Thus in spite of the second law inequality which might lead one to expect that the average would decay exponentially with time, the exponential probability ratio given by the FT "exactly" cancels the negative exponential in the average above leading to an average which is unity for all time. The first derivation of the nonequilibrium partition identity for Hamiltonian systems was by Yamada and Kawasaki in 1967. For thermostatted deterministic systems the first derivation was by Morriss and Evans in 1985. | https://en.wikipedia.org/wiki?curid=16384773 |
Virgocentric flow The (VCF) is the preferred movement of Local Group galaxies towards the Virgo cluster caused by its overwhelming gravity, which separates bound objects from the Hubble flow of cosmic expansion. The VCF can refer to the Local Group's movement towards the Virgo "Super"cluster, since its center is considered synonymous with the Virgo cluster, but more tedious to ascertain due to its much larger volume. The excess velocity of Local Group galaxies towards, and with respect to, the Virgo Cluster are 100 to 400 km/s. This excess velocity is referred to as each galaxy's peculiar velocity. | https://en.wikipedia.org/wiki?curid=16399074 |
Genesee Scientific Corporation is a manufacturer and distributor of products to global life science research markets. With thousands of products available, its markets include pharmaceutical and biotechnology companies, colleges, universities and secondary education institutions, medical research institutions, hospitals and reference labs and quality control, process control and research and development laboratories. The company has innovated the UPrep column used in deoxyribonucleic acid (DNA) purification. The idea behind the UPrep column, is that most, if not all, nucleic acid purification or clean-up kits come equipped with 10-15% more reagent volume than is actually needed for the number of columns the kit contains. This means that for a kit with 100 columns, you end up with enough reagent for another 10 to 15 preps after you run out of columns. Normally, this excess reagent is tossed out. UPrep columns allow you to use this extra reagent for additional preps. has also been responsible for developing Blue Devil autoradiography film which produces exceptional clarity and sharpness with extremely low backgrounds. Blue Devil Film is used for blotting, sequencing, chemiluminescent autoradiography (ecl) and gel shift analysis. It is designed for use with 14C, 35S, 32P, and 125I. is the world leader in innovation for and supply to the "Drosophila" (fruit fly) research community. "Drosophila" are widely used as a model organism in the field of genetics | https://en.wikipedia.org/wiki?curid=16403515 |
Genesee Scientific has been awarded three patents by the United States Patent and Trademark Office for its revolutionary "Drosophila" vial racking system (patent numbers D673,296 S; 8,136,679 B2; and 8,430,251 B2). This "Drosophila" vial racking system significantly decreases time spent racking vials and is more environmentally friendly compared to traditional vial packaging configurations. has also developed the first atlas of "Drosophila" phenotypic markers available on mobile devices. Genesee the "Drosophila" App is a free tool providing researchers with a quick reference to various "Drosophila" phenotypes and is a valuable teaching tool for new "Drosophila" researchers. "Following is a list of links to articles published in scientific journals that cite Genesee Scientific:" | https://en.wikipedia.org/wiki?curid=16403515 |
Helferich method The may refer to: | https://en.wikipedia.org/wiki?curid=16410813 |
Nicolaas Jan van Strien (1 April 1946 – 7 February 2008), or just Nico van Strien, was a zoologist and conservationist of Dutch ancestry. He became notable for his conservation projects on the Sumatran Rhinoceros and the Javan Rhinoceros. Nico van Strien was born in Etterbeek, Belgium on 1 April 1946. He obtained a Master of Science degree at the Free University of Amsterdam in 1971. In 1985 he received a Ph.D. degree in Agricultural science from Wageningen University. Dr. van Strien was the South-East Asian programme officer for the International Rhino Foundation (IRF) and the co-chairman of the IUCN / SSC Asian Rhino Specialist Group from 1998 to 2008. He took part in Rhinoceros conservation projects in India, Sumatra and Java for 30 years. His field research on the Sumatran Rhinoceros in Gunung Leuser National Park was important for conservation measurements on this species. He further co-ordinated anti-poaching activities in the key Asian rhinoceros reserves, and was involved in captive breeding programs. Nico van Strien was also a key member at the IUCN Tapir Specialist Group. He also provided critical technical advice to the UNDP-Global Environment Facility, the IUCN Asian Rhino Specialist Group, and the US Fish and Wildlife Service. His efforts were instrumental in helping people to work together for rhino conservation throughout Southeast Asia, including convening experts working on greater one-horned rhinos in India and Nepal | https://en.wikipedia.org/wiki?curid=16430022 |
Nicolaas Jan van Strien Nico van Strien was a long-term member of many other organizations, chairman of the Van Tienhoven Foundation for International Nature Protection, serving on the Board of the Netherlands Committee for International Nature Conservation and the Golden Ark Foundation (now Future for Nature), the , and a life member of the Malawi Wildlife Society. Since 1980 Nico had also been collecting records towards a historical "Mammal Atlas of South East Asia", which unfortunately never was fully completed. Furthermore, he was co-founder of the Rhino Resource Center. In spring 2007 cancer was diagnosed of which he died in his home in Doorn, Netherlands on 7 February 2008. | https://en.wikipedia.org/wiki?curid=16430022 |
Zero mode In physics, a zero mode is an eigenvector with a vanishing eigenvalue. In various subfields of physics zero modes appear whenever a physical system possesses a certain symmetry. For example, normal modes of multidimensional harmonic oscillator (e.g. a system of beads arranged around the circle, connected with springs) corresponds to elementary vibrational modes of the system. In such a system zero modes typically occur and are related with a rigid rotation around the circle. The kernel of an operator consists of left zero modes, and the cokernel consists of the right zero modes. | https://en.wikipedia.org/wiki?curid=16437548 |
Institute Ice Stream The () is an ice stream flowing north into the Ronne Ice Shelf, Antarctica, southeast of Hercules Inlet. The feature was traversed by the United States Antarctic Research Program (USARP) Ellsworth–Byrd Seismic Party, 1958–59, and the USARP – University of Wisconsin Seismic Party, 1963–64. It was delineated by the Scott Polar Research Institute – National Science Foundation – Technical University of Denmark airborne radio echo sounding program, 1967–79, and in association with Foundation Ice Stream and Support Force Glacier, named after the Scott Polar Research Institute, Cambridge, England. | https://en.wikipedia.org/wiki?curid=16444026 |
Woodchuck hepatitis virus (WHV) is a species of the genus "Orthohepadnavirus". It was first discovered in 1977 in a captive population of "Marmota monax", but has since been discovered in wild populations in the Eastern United States. Infected woodchucks which are unable to clear the infection inevitably develop hepatocellular carcinoma; this has led to the use of WHV in woodchucks as a model for human "Hepatitis B virus" infections. | https://en.wikipedia.org/wiki?curid=16453669 |
National Institute for Research in Reproductive Health National Institute For Research in Reproductive Health (NIRRH), is a Research institute of the Indian Council of Medical Research (ICMR). It was previously known as the Institute of Research in Reproduction. It was established in 1970, by the joining two ICMR units, the Reproductive Physiology Unit and the Contraceptive Testing Unit. It is affiliated to the University of Mumbai for M.Sc. and Ph.D. programmes in Biochemistry, Applied Biology and Life Sciences. | https://en.wikipedia.org/wiki?curid=16454759 |
Keystone (limestone) Keystone is a type of limestone, or coral rag, quarried in the Florida Keys, in particular from Windley Key fossil quarry, which is now a State Park of Florida. The limestone is Pleistocene in age, and the rock primarily consists of scleractinian coral, such as Elkhorn coral and Brain coral. The Hurricane Monument, commemorating victims of the Labor Day Hurricane of 1935, and located at mile marker 82 on U.S. Route 1 near Islamorada, is constructed of keystone, as is the David W. Dyer Federal Building and United States Courthouse. | https://en.wikipedia.org/wiki?curid=16474288 |
Microcarrier A microcarrier is a support matrix allowing for the growth of adherent cells in bioreactors. In 1967, microcarrier development began when van Wezel found that microcarriers could support the growth of anchorage-dependent cells. Microcarriers are typically 125 - 250 micrometre spheres and their density allows them to be maintained in suspension with gentle stirring. Microcarriers can be made from a number of different materials including DEAE-dextran, glass, polystyrene plastic, acrylamide, collagen, and alginate. These microcarrier materials, along with different surface chemistries, can influence cellular behavior, including morphology and proliferation. Surface chemistries can include extracellular matrix proteins, recombinant proteins, peptides, and positively or negatively charged molecules. Microcarriers are regularly used to grow protein-producing or virus-generating adherent cell populations in the large-scale commercial production of biologics (proteins) and vaccines. cell culture is typically carried out in spinner flasks, although other vessels such as rotating wall microgravity bioreactors or fluidized bed bioreactors can also support microcarrier-based cultures | https://en.wikipedia.org/wiki?curid=16482142 |
Microcarrier The advantages of microcarrier technology in the vaccine industry include (a) ease of scale-up, (b) ability to precisely control cell growth conditions in sophisticated, computer-controlled bioreactors, (c) an overall reduction in the floor space and incubator volume required for a given-sized manufacturing operation, and (d) a drastic reduction in technician labor. Several types of microcarriers are available commercially including alginate-based (GEM, Global Cell Solutions), dextran-based (Cytodex, GE Healthcare), collagen-based (Cultispher, Percell), and polystyrene-based (SoloHill Engineering) microcarriers. They differ in their porosity, specific gravity, optical properties, presence of animal components, and surface chemistries. A liquid-based assembly method was developed by P. Chen et al. for assembling cell-seeded microcarriers into diverse structures. Neuron-seeded microcarriers were assembled for formation of 3D neural networks with controlled global shape. This method is potentially useful for tissue engineering and neuroscience. | https://en.wikipedia.org/wiki?curid=16482142 |
Amé Pictet Pictet was born in Geneva, studied with August Kekulé at the University of Bonn where he received his Ph.D in 1879. From 1894 til 1932 he was professor at the University of Geneva. Pictet died in Geneva in 1937. | https://en.wikipedia.org/wiki?curid=16492137 |
Stefan Niementowski Polish Chemistry | https://en.wikipedia.org/wiki?curid=16507033 |
Cumulative dose is the total dose resulting from repeated exposures of ionizing radiation to an occupationally exposed worker to the same portion of the body, or to the whole body, over a period of time. In medicine, the total amount of a drug or radiation given to a patient over time; for example, the total dose of radiation given in a series of radiation treatments. | https://en.wikipedia.org/wiki?curid=16507851 |
Fuel temperature coefficient of reactivity is the change in reactivity of the nuclear fuel per degree change in the fuel temperature. The coefficient quantifies the amount of neutrons that the nuclear fuel (such as uranium-238) absorbs from the fission process as the fuel temperature increases. It is a measure of the stability of the reactor operations. This coefficient is also known as the Doppler coefficient. | https://en.wikipedia.org/wiki?curid=16508375 |
Total effective dose equivalent The (TEDE) is a radiation dosimetry quantity defined by the US Nuclear Regulatory Commission to monitor and control human exposure to ionizing radiation. It is defined differently in the NRC regulations and NRC glossary. According to the regulations, it is the sum of effective dose equivalent from external exposure and committed effective dose equivalent from internal exposure, thereby taking into account all known exposures. However, the NRC glossary defines it as the sum of the deep-dose equivalent and committed effective dose equivalent, which would appear to exclude the effective dose to the skin and eyes from non-penetrating radiation such as beta. These surface doses are included in the NRC's shallow dose equivalent, along with contributions from penetrating (gamma) radiation. Regulatory limits are imposed on the TEDE for occupationally exposed individuals and members of the general public. | https://en.wikipedia.org/wiki?curid=16509260 |
Deep-dose equivalent The (DDE) is a measure of external radiation exposure defined by US regulations. It is reported alongside eye and shallow dose equivalents on typical US dosimetry reports. It represents the dose equivalent at a tissue depth of 1 cm (1000 mg/cm2) due to external whole-body exposure to ionizing radiation. Dose due to external radiation tends to decrease with depth because of the shielding effects of outer tissues. The reference depth of 1 cm essentially discounts alpha and beta radiation that are easily shielded by the skin, clothing, and bone surface, while taking minimal credit for any self-shielding from the more penetrating gamma rays. This makes the deep-dose equivalent a conservative measure of internal organ exposure to external radiation, while eye and skin exposure to external radiation must be accounted differently. does include any contribution from internal contamination. | https://en.wikipedia.org/wiki?curid=16509322 |
Ion Tănăsescu (chemist) Ion Tănăsescu (February 23, 1892 – December 28, 1959) was a Romanian chemist. He discovered the Lehmstedt-Tanasescu reaction, which was improved by Kurt Lehmstedt. He studied at the University of Bucharest and the University of Cluj. He was elected a titular member of the Romanian Academy in 1955. | https://en.wikipedia.org/wiki?curid=16545892 |
Differential display (also referred to as DDRT-PCR or DD-PCR) is a laboratory technique that allows a researcher to compare and identify changes in gene expression at the mRNA level between two or more eukaryotic cell samples. It was the most commonly used method to compare expression profiles of two eukaryotic cell samples in the 1990s. By 2000, differential display was superseded by DNA microarray approaches. In differential display, first all the RNA in each sample is reverse transcribed using a set of 3′ "anchored primers" (having a short sequence of deoxy-thymidine nucleotides at the end) to create a cDNA library for each sample, followed by PCR amplification using arbitrary 3′ primers for cDNA strand amplification together with anchored 3′ primers for RNA strand amplification, identical to those used to create the library; about forty arbitrary primers is the optimal number to transcribe almost all of the mRNA. The resulting transcripts are then separated by electrophoresis and visualized, so that they can be compared. The method was prone to error due to different mRNAs migrated into single bands, differences in less abundant mRNAs getting drowned by more abundant mRNAs, sensitivity to small changes in cell culture conditions, and a tendency to amplify 3′ fragments rather than full mRNAs, and the necessity to use about 300 primers to catch all the mRNA. The method was first published in "Science" in 1992. | https://en.wikipedia.org/wiki?curid=16565278 |
Dexter electron transfer (also called Dexter electron exchange and Dexter energy transfer) is a fluorescence quenching mechanism in which an excited electron is transferred from one molecule (a donor) to a second molecule (an acceptor) via a non radiative path. This process requires a wavefunction overlap between the donor and acceptor, which means it can only occur at short distances; typically within 10 Å. The excited state may be exchanged in a single step, or in two separate charge exchange steps. This short range energy transfer process was first theoretically proposed by D. L. Dexter in 1953. The Dexter energy transfer rate, formula_1, is indicated by the proportionality where formula_3 is the separation of the donor from the acceptor, formula_4 is the sum of the Van der Waals radii of the donor and the acceptor, and formula_5 is the spectral overlap integral defined by | https://en.wikipedia.org/wiki?curid=16569377 |
Australian Meteorological and Oceanographic Society The (AMOS) is an independent learned society that supports and fosters interest in Meteorology, Oceanography and other related sciences. AMOS was founded in April 1987 as a successor to the Australian Branch of the Royal Meteorological Society which at the time had existed for 15 years. AMOS publishes the bi-monthly "Bulletin of the Australian Meteorological and Oceanographic Society", and quarterly the scientific journal "The Australian Meteorological and Oceanographic Journal". AMOS has issued a "Statement on Climate Change", wherein they conclude, “Global climate change and global warming are real and observable…It is highly likely that those human activities that have increased the concentration of greenhouse gases in the atmosphere have been largely responsible for the observed warming since 1950. The warming associated with increases in greenhouse gases originating from human activity is called the enhanced greenhouse effect. The atmospheric concentration of carbon dioxide has increased by more than 30% since the start of the industrial age and is higher now than at any time in at least the past 650,000 years. This increase is a direct result of burning fossil fuels, broad-scale deforestation and other human activity.” In February 2016 many of the climate scientists attending the annual AMOS conference in Melbourne participated in a lunchtime protest against the CSIRO cuts to climate research programs announced by CSIRO CEO Larry Marshall on 4 February 2016. Official Website | https://en.wikipedia.org/wiki?curid=16575482 |
SCICEX SCICEX, standing for "Scientific Ice Expeditions", was a five-year (1995–1999) scientific research program involving a collaboration between the U.S. Navy and academic researchers from a variety of different universities. The object of study was geophysical and oceanological conditions in the Arctic Ocean. The Navy made available a nuclear submarine for each research cruise. | https://en.wikipedia.org/wiki?curid=16577671 |
Ion drift meter An ion drift meter is a device used to measure the velocity of individual ions in the area of a spacecraft. This information can then be used to calculate the ion drift in the space surrounding the instrument as well as the strength of an electric field present, provided that the magnetic field strength has been determined using a magnetometer. The device itself works by allowing ions to pass through an opening at the front of the instrument and measuring the currents produced by the impacts of ions in different locations on a grid at the back. The trajectories of the ions can then be determined. Ion drift meters have been used on several spacecraft including Dynamics Explorer and CHAMP and will be onboard the forthcoming Ionospheric Connection Explorer mission. | https://en.wikipedia.org/wiki?curid=16610108 |
Ishimori equation The (IE) is a partial differential equation proposed by the Japanese mathematician . Its interest is as the first example of a nonlinear spin-one field model in the plane that is integrable . The has the form The Lax representation of the equation is given by Here the formula_7 are the Pauli matrices and formula_8 is the identity matrix. IE admits an important reduction: in 1+1 dimensions it reduces to the continuous classical Heisenberg ferromagnet equation (CCHFE). The CCHFE is integrable. The equivalent counterpart of the IE is the Davey-Stewartson equation. | https://en.wikipedia.org/wiki?curid=16617601 |
MS 1512-cB58 is a galaxy in the Boötes constellation. It is a starburst galaxy that is being strongly gravitationally lensed, magnifying its apparent size by 30−50 times. | https://en.wikipedia.org/wiki?curid=16625060 |
55701 Ukalegon 55701 Ukalegon, provisional designation , is a Jupiter trojan discovered on 17 October 1977, by C. J. van Houten and I. van Houten-Groeneveld at Palomar Schmidt. It is named after Ucalegon, one of the Elders of Troy, whose house was set on fire by the Achaeans when they sacked the city. | https://en.wikipedia.org/wiki?curid=16634349 |
Vyāsa (crater) Vyāsa is a crater on Mercury. It was named by the IAU in 1979, after the Indian poet Vyasa. Vyāsa is an ancient crater, overlain by two much younger craters – Stravinsky and Sholem Aleichem. | https://en.wikipedia.org/wiki?curid=16640719 |
Raphael (crater) Raphael is a crater on Mercury. Unlike other Mercurian craters of similar size, Raphael is not multi-ringed. | https://en.wikipedia.org/wiki?curid=16640741 |
Homer (crater) Homer is a crater on Mercury. It is one of many Peak-ring basins on Mercury. Deposits of material in and around this crater suggest the possibility of explosive volcanic eruptions at some point in the planet's history. The crater name was approved by the IAU in 1976. The naming of Stark Y crater on the moon, located northwest of Stark, as "Homer", was not approved by the IAU. | https://en.wikipedia.org/wiki?curid=16640770 |
Orthobaric density The orthobaric density of a compound is the density of coexisting phases (liquid, gas, or solid) at a given temperature. For any temperature below the critical point, the density of the gas will be less than that of the liquid. At the critical point, the density of the liquid and gas phases are identical and the compound becomes a supercritical fluid. | https://en.wikipedia.org/wiki?curid=16671520 |
Root cap The root cap is a type of tissue at the tip of a plant root. It is also called calyptra. Root caps contain statocytes which are involved in gravity perception in plants. If the cap is carefully removed the root will grow randomly. The root cap protects the growing tip in plants. It secretes mucilage to ease the movement of the root through soil, and may also be involved in communication with the soil microbiota. The purpose of the root cap is to enable downward growth of the root, with the root cap covering the sensitive tissue in the root. Also, the root cap enables geoperception or gravitropism. This allows the plant to grow downwards (with gravity) or upwards (against gravity). The root cap is absent in some parasitic plants and some aquatic plants, in which a sac-like structure called the "root pocket" may form instead. | https://en.wikipedia.org/wiki?curid=16683507 |
Leopold von Pebal (29 December 1826 – 17 February 1887) was an Austrian chemist. In 1851 he obtained his PhD at the University of Graz, followed by several years working as an assistant at the Joanneum. In 1855 he became a privat-docent of theoretical chemistry. Afterwards, he continued his education at Heidelberg, where he studied with Robert Bunsen (1811-1899) and Gustav Robert Kirchhoff (1824-1887). From 1857 onward, he worked as an associate professor at the University of Lemberg. Pebal remained a professor at Lemberg until 1865, after which, he became a professor at the University of Graz. He planned the new chemistry laboratory in Graz, which was finished in 1878. Adolph Wurtz (1817-1884) was sent by the French government to report about the laboratory. The possibility that the institute would be divided into two independent institutes troubled Pebal, but with the help of colleagues the problems were resolved. Pebal was murdered by an employee of the university in front of his laboratory, where he died shortly after the attack. His wide-ranging research included studies involving the composition of stearic and citric acid. | https://en.wikipedia.org/wiki?curid=16689326 |
Theodor Wertheim He studied organic chemistry in Berlin as a pupil of Eilhard Mitscherlich, and in 1843 travelled to the University of Prague, where he studied under Josef Redtenbacher. He served as privatdozent in Vienna, and from 1853 to 1860, was a professor at the University of Pest. From 1861 onward, he was a professor at the University of Graz. In May 1864, he moved back to Vienna, where he died soon afterwards. In 1848 he became a corresponding member of the Vienna Academy of Sciences. In 1844 Wertheim distilled a pungent substance from garlic, naming it "allyl". In his research, he noticed the close relationship between garlic oil and mustard oil. He published a number of studies on garlic oil, piperine, quinine and coniine in Liebig’s Annalen der Chemie. | https://en.wikipedia.org/wiki?curid=16695500 |
Viktor von Lang (2 March 1838 – 3 July 1921) was an Austrian chemist. He is counted among the pioneers and founders of crystal physics. Lang earned his doctorate from the University of Giessen in 1859 with a thesis titled "Physikalische Verhältnisse kristallisierter Körper". From 1865 to 1909, Lang served as director of the "Physikalisches Kabinett" in Vienna. His book on introductory theoretical physics, "Einleitung in die theoretische physik", was published in eight editions from 1867 to 1891. With crystallographer Wilhelm Josef Grailich, he was co-author of "Untersuchungen über die Physikalischen Verhältnisse Krystallisirter Körper" ("Investigations into the physical conditions of crystallized bodies"). The mineral langite was named in his honor by Nevil Story Maskelyne. | https://en.wikipedia.org/wiki?curid=16695650 |
Heinrich Hlasiwetz (April 7, 1825 – October 7, 1875) was an Austrian chemist born in Reichenberg, Bohemia. Son of a pharmacist, he studied at the University of Jena, where his instructors included Johann Wolfgang Döbereiner (1780-1849), Heinrich Wilhelm Ferdinand Wackenroder (1798-1854) and Matthias Jakob Schleiden (1804-1881). Later he studied under Josef Redtenbacher (1810–1870) in Prague. In 1848 he earned the diploma of "Magister Pharmacia", and during the following year received his doctorate in chemistry. In 1849 he began work as an assistant to Friedrich Rochleder (1819-1874), later becoming an associate professor of chemistry at the University of Innsbruck (1854). In 1867 he became a professor at the Vienna University of Technology, where from 1869 he represented general and analytical chemistry. During his career he largely worked with resins, tannins and protein compounds. Hlasiwetz is remembered for his chemical analysis of quercitrin, phloroglucinol, resorcinol and creosote. | https://en.wikipedia.org/wiki?curid=16695722 |
Andrius Baltuška (born 26 November 1971 in Leningrad) is a Lithuanian physicist. Baltuška studied physics at the University of Vilnius later at the University of Amsterdam and received his Ph.D. from the University of Groningen in 2000. After postdoctoral positions at the University of Tokyo, Technical University of Vienna and Max Planck Institute for Quantum Optics he became Professor at the Technical University of Vienna in 2006. | https://en.wikipedia.org/wiki?curid=16709409 |
Ronald Micura Micura studied chemistry at the University of Linz, where he also received his Ph.D. in 1995. After a postdoc position at the University of Zurich and the Skaggs Institute for Chemical Biology, he became professor at the University of Innsbruck in 2000. | https://en.wikipedia.org/wiki?curid=16709606 |
FSC 15307+3253 FSC15307+3253 (or IRAS F15307+3252) is an ultraluminous infrared galaxy (ULIRG), with a luminosity between 8 and 1000 µm of approximately 2 L, possibly the highest currently known. The "FSC" refers to "Faint Source Catalogue", one of the source catalogs produced by the IRAS infrared survey mission. The emission is believed due to some combination of starburst activity and accretion onto a super-massive black hole, producing primary radiation at shorter wavelengths which is mostly blocked by obscuring dust, which is in turn heated and re-radiates in the infrared. The redshift of the source is "z" = 0.93, indicating a distance of the order of 7 billion light years. | https://en.wikipedia.org/wiki?curid=16721711 |
Hermann Schmitz (entomologist) Hermann Schmitz (12 August 1878 in Elberfeld, Wuppertal – 1 September 1960 in Bad Godesberg) was a German entomologist who specialised in Hymenoptera and Diptera. His personal collection of data on flies and the literature of flies were looted by the Nazis during World War II. He was a Jesuit of German origin living in Limburg (Netherlands), at the time. Schmitz was a priest in Valkenburg. He is best known for his studies of Phoridae. His collections are in Natuurhistorisch Museum Maastricht (Diptera and Hymenoptera) Museum Alexander Koenig in Bonn (world Phoridae and Lepidoptera from the Canary islands) He wrote Phoridae In: E. Lindner, Editor, "Die Fliegen der palaearktischen Region" (Lieferung 165) 4 (33) (1951) and many scientific papers mostly on this family. | https://en.wikipedia.org/wiki?curid=16726426 |
Minerals Yearbook The is an annual publication from the United States Geological Survey. It reviews the mineral and material industries of the United States and other countries. The "Minerals Yearbook" contains statistical production data as well as information on economic and technical trends. First published in 1933, it was preceded by The "Mineral Resources of the United States". Current issues are published in three volumes: | https://en.wikipedia.org/wiki?curid=16732549 |
Astro-comb An astro-comb is a type of frequency comb which increases the resolution of previous spectrographs by nearly a hundredfold, allowing it to be used as an observational tool in astronomy and detect redshift wobbles caused by smaller exoplanets than what was detectable with traditional calibrators. Existing frequency combs were too precise to be useful for astronomy, with "teeth" too close together. In other words, the repetition rate or the frequency spacing between the comb lines was much smaller (<1 gigahertz) than that required for astronomical applications (~tens of gigahertz or more). A "green astro-comb" was installed in January 2013 in the High Accuracy Radial velocity Planet Searcher in the Northern hemisphere (HARPS-N) spectrograph at the Telescopio Nazionale Galileo on the Canary Islands. The device was developed by a team led by Chih-Hao Li of Harvard University. The astro-comb uses a pulsed laser to filter starlight before feeding the signal into a spectrograph. It has the potential to revolutionise astrophysical spectroscopy and discover other Earth-like planets outside our solar system. Currently, it is gathering data from Venus to demonstrate its ability to discover exoplanets. | https://en.wikipedia.org/wiki?curid=16733372 |
Johann Friedrich Wolff (1778- 1806) was a German physician, botanist, entomologist and natural history illustrator. He wrote and illustrated "Commentatio de Lemna". Altdorfii et Norimbergae (1801), "Icones Cimicum descriptionibus illustratae". Erlangen 1800-1811 and some short papers. Wolff is the author of several genera and species of Hemiptera. | https://en.wikipedia.org/wiki?curid=16742939 |
Arco Valley Pearl The is a white natural blister baroque pearl with pink and yellow overtones. It measures 79 x 41 x 34 mm. It is the largest natural pearl outside a museum and the second biggest ever. Mongolian emperor Khubilai Khan reportedly gave it to Marco Polo. During 2007, an UAE collectionner said he bought the pearl from a French owner for 8M US$ but it is still owned by a European company (August 2008). | https://en.wikipedia.org/wiki?curid=16750556 |
Tadeusz Jaczewski (1 February 1899, Saint Petersburg – 25 February 1974) was a Polish entomologist who specialised in Hemiptera. Jaczewski studied at the Saint Petersburg State University, then taught at the University of Warsaw. He also worked for the Warsaw Zoological Museum. He published many papers on the insect fauna of Poland and with I.M Kerzhner 1964 wrote Order Hemiptera (Heteroptera). In Bei-Bienko, G. Ya. (ed.), "Keys to the insects of the European" USSR 1: 655-845 1964.He was a specialist in Nepomorpha | https://en.wikipedia.org/wiki?curid=16763511 |
Long non-coding RNA Long non-coding RNAs (long ncRNAs, lncRNA) are a type of RNA, defined as being transcripts with lengths exceeding 200 nucleotides that are not translated into protein. This somewhat arbitrary limit distinguishes long ncRNAs from small non-coding RNAs such as microRNAs (miRNAs), small interfering RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), and other short RNAs. Long intervening/intergenic noncoding RNAs (lincRNAs) are sequences of lncRNA which do not overlap protein-coding genes. In 2007 a study found only one-fifth of transcription across the human genome is associated with protein-coding genes, indicating at least four times more long non-coding than coding RNA sequences. However, it is large-scale complementary DNA (cDNA) sequencing projects such as FANTOM (Functional Annotation of Mammalian cDNA) that reveal the complexity of this transcription. The FANTOM3 project identified ~35,000 non-coding transcripts from ~10,000 distinct loci that bear many signatures of mRNAs, including 5’ capping, splicing, and poly-adenylation, but have little or no open reading frame (ORF). While the abundance of long ncRNAs was unanticipated, this number represents a conservative lower estimate, since it omitted many singleton transcripts and non-polyadenylated transcripts (tiling array data shows more than 40% of transcripts are non-polyadenylated) | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA However, unambiguously identifying ncRNAs within these cDNA libraries is challenging since it can be difficult to distinguish protein-coding transcripts from non-coding transcripts. It has been suggested through multiple studies that testis, and neural tissues express the greatest amount of long non-coding RNAs of any tissue type. Using FANTOM5, 27,919 long ncRNAs have been identified in various human sources. Quantitatively, lncRNAs demonstrate ~10-fold lower abundance than mRNAs in a population of cells, which is explained by higher cell-to-cell variation of expression levels of lncRNA genes in the individual cells, when compared to protein-coding genes. In general, the majority (~78%) of lncRNAs are characterized as tissue-specific, as opposed by only ~19% of mRNAs. In addition to higher tissue specificity, lncRNAs are characterized by higher developmental stage specificity, and cell subtype specificity in heterogeneous tissues, such as human neocortex. In 2018, a comprehensive integration of lncRNAs from existing databases, published literatures and novel RNA assemblies based on RNA-seq data analysis, revealed that there are 270,044 lncRNA transcripts in humans. Big efforts have been put into investigating lncRNAs in plant species, since they remain far more uninvestigated than in mammal species. An extensive study considering 37 higher plant species and six algae came out at the end of 2015 and identified ~200,000 non-coding transcripts using an "in-silico" approach | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA With this study it was created the Green Non-Coding Database (GreeNC), which is a repository of plant lncRNAs. In 2005 the landscape of the mammalian genome was described as numerous 'foci' of transcription that are separated by long stretches of intergenic space. While long ncRNAs are located and transcribed within the intergenic stretches, the majority are transcribed as complex, interlaced networks of overlapping sense and antisense transcripts that often include protein-coding genes, giving rise to a complex hierarchy of overlapping isoforms. Genomic sequences within these transcriptional foci are often shared within a number of different coding and non-coding transcripts in the sense and antisense directions For example, 3012 out of 8961 cDNAs previously annotated as truncated coding sequences within FANTOM2 were later designated as genuine ncRNA variants of protein-coding cDNAs. While the abundance and conservation of these interleaved arrangements suggest they have biological relevance, the complexity of these foci frustrates easy evaluation. The GENCODE consortium has collated and analysed a comprehensive set of human lncRNA annotations and their genomic organisation, modifications, cellular locations and tissue expression profiles. Their analysis indicates human lncRNAs show a bias toward two-exon transcripts. There has been considerable debate about whether lncRNAs have been misannotated and do in fact encode proteins | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Several lncRNAs have been found to in fact encode for peptides with biologically significant function. Ribosome profiling studies have suggested that anywhere from 40% to 90% of annotated lncRNAs are in fact translated, although there is disagreement about the correct method for analyzing ribosome profiling data. Additionally, it is thought that many of the peptides produced by lncRNAs may be highly unstable and without biological function. Initial studies into lncRNA conservation noted that as a class, they were enriched for conserved sequence elements, depleted in substitution and insertion/deletion rates and depleted in rare frequency variants, indicative of purifying selection maintaining lncRNA function. However, further investigations into vertebrate lncRNAs revealed that while lncRNAs are conserved in sequence, they are not conserved in transcription. In other words, even when the sequence of a human lncRNA is conserved in another vertebrate species, there is often no transcription of a lncRNA in the orthologous genomic region. Some argue that these observations suggest non-functionality of the majority of lncRNAs, while others argue that they may be indicative of rapid species-specific adaptive selection. While the turnover of lncRNA transcription is much higher than initially expected, it is important to note that still, hundreds of lncRNAs are conserved at the sequence level | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA There have been several attempts to delineate the different categories of selection signatures seen amongst lncRNAs including: lncRNAs with strong sequence conservation across the entire length of the gene, lncRNAs in which only a portion of the transcript (e.g. 5′ end, splice sites) is conserved, and lncRNAs that are transcribed from syntenic regions of the genome but have no recognizable sequence similarity. Additionally, there have been attempts to identify conserved secondary structures in lncRNAs, though these studies have currently given way to conflicting results. Large-scale sequencing of cDNA libraries and more recently transcriptomic sequencing by next generation sequencing indicate that long noncoding RNAs number in the order of tens of thousands in mammals. However, despite accumulating evidence suggesting that the majority of these are likely to be functional, only a relatively small proportion has been demonstrated to be biologically relevant. As of January 2016, 294 LncRNAs have been functionally annotated in LncRNAdb (a database of literature described LncRNAs), with the majority of these (183 LncRNAs) being described in humans. As of June 2018, a total of 1867 human lncRNAs that with experimental evidences have been community-curated in LncRNAWiki (a wiki-based, publicly editable and open-content platform for community curation of human lncRNAs) in respect of the functional mechanisms and disease associations, which can also be accessed in LncBook | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA According to the curation of functional mechanisms of lncRNAs based on the literatures, lncRNAs are extensively reported to be involved in transcriptional regulation. A further large-scale sequencing study provides evidence that many transcripts thought to be lncRNAs may, in fact, be translated into proteins. In eukaryotes, RNA transcription is a tightly regulated process. NcRNAs can target different aspects of this process, targeting transcriptional activators or repressors, different components of the transcription reaction including RNA polymerase (RNAP) II and even the DNA duplex to regulate gene transcription and expression. In combination these ncRNAs may comprise a regulatory network that, including transcription factors, finely control gene expression in complex eukaryotes. NcRNAs modulate the function of transcription factors by several different mechanisms, including functioning themselves as co-regulators, modifying transcription factor activity, or regulating the association and activity of co-regulators. For example, the ncRNA Evf-2 functions as a co-activator for the homeobox transcription factor Dlx2, which plays important roles in forebrain development and neurogenesis. Sonic hedgehog induces transcription of Evf-2 from an ultra-conserved element located between the Dlx5 and Dlx6 genes during forebrain development. Evf-2 then recruits the Dlx2 transcription factor to the same ultra-conserved element whereby Dlx2 subsequently induces expression of Dlx5 | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA The existence of other similar ultra- or highly conserved elements within the mammalian genome that are both transcribed and fulfil enhancer functions suggest Evf-2 may be illustrative of a generalised mechanism that tightly regulates important developmental genes with complex expression patterns during vertebrate growth. Indeed, the transcription and expression of similar non-coding ultraconserved elements was shown to be abnormal in human leukaemia and to contribute to apoptosis in colon cancer cells, suggesting their involvement in tumorigenesis. Local ncRNAs can also recruit transcriptional programmes to regulate adjacent protein-coding gene expression. For example, divergent lncRNAs that are transcribed in the opposite direction to nearby protein-coding genes (comprise a significant proportion ~20% of total lncRNAs in mammalian genomes) possibly regulate the transcription of nearby adjacent essential developmental regulatory genes in pluripotent cells The RNA binding protein TLS, binds and inhibits the CREB binding protein and p300 histone acetyltransferease activities on a repressed gene target, cyclin D1. The recruitment of TLS to the promoter of cyclin D1 is directed by long ncRNAs expressed at low levels and tethered to 5’ regulatory regions in response to DNA damage signals. Moreover, these local ncRNAs act cooperatively as ligands to modulate the activities of TLS | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA In the broad sense, this mechanism allows the cell to harness RNA-binding proteins, which make up one of the largest classes within the mammalian proteome, and integrate their function in transcriptional programs. Nascent long ncRNAs have been shown to increase the activity of CREB binding protein, which in turn increases the transcription of that ncRNA. A recent study found that a lncRNA in the antisense direction of the Apolipoprotein A1 (APOA1) regulates the transcription of APOA1 through epigenetic modifications. Recent evidence has raised the possibility that transcription of genes that escape from X-inactivation might be mediated by expression of long non-coding RNA within the escaping chromosomal domains. NcRNAs also target general transcription factors required for the RNAP II transcription of all genes. These general factors include components of the initiation complex that assemble on promoters or involved in transcription elongation. A ncRNA transcribed from an upstream minor promoter of the dihydrofolate reductase (DHFR) gene forms a stable RNA-DNA triplex within the major promoter of DHFR to prevent the binding of the transcriptional co-factor TFIIB. This novel mechanism of regulating gene expression may in fact represent a widespread method of controlling promoter usage given that thousands of such triplexes exist in eukaryotic chromosome. The U1 ncRNA can induce transcription initiation by specifically binding to and stimulating TFIIH to phosphorylate the C-terminal domain of RNAP II | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA In contrast the ncRNA 7SK, is able to repress transcription elongation by, in combination with HEXIM1/2, forming an inactive complex that prevents the PTEFb general transcription factor from phosphorylating the C-terminal domain of RNAP II, thereby repressing global elongation under stressful conditions. These examples, which bypass specific modes of regulation at individual promoters to mediate changes directly at the level of initiation and elongation transcriptional machinery, provide a means of quickly affecting global changes in gene expression. The ability to quickly mediate global changes is also apparent in the rapid expression of non-coding repetitive sequences. The short interspersed nuclear (SINE) Alu elements in humans and analogous B1 and B2 elements in mice have succeeded in becoming the most abundant mobile elements within the genomes, comprising ~10% of the human and ~6% of the mouse genome, respectively. These elements are transcribed as ncRNAs by RNAP III in response to environmental stresses such as heat shock, where they then bind to RNAP II with high affinity and prevent the formation of active pre-initiation complexes. This allows for the broad and rapid repression of gene expression in response to stress. A dissection of the functional sequences within Alu RNA transcripts has drafted a modular structure analogous to the organization of domains in protein transcription factors | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA The Alu RNA contains two ‘arms’, each of which may bind one RNAP II molecule, as well as two regulatory domains that are responsible for RNAP II transcriptional repression in vitro. These two loosely structured domains may even be concatenated to other ncRNAs such as B1 elements to impart their repressive role. The abundance and distribution of Alu elements and similar repetitive elements throughout the mammalian genome may be partly due to these functional domains being co-opted into other long ncRNAs during evolution, with the presence of functional repeat sequence domains being a common characteristic of several known long ncRNAs including Kcnq1ot1, Xlsirt and Xist. In addition to heat shock, the expression of SINE elements (including Alu, B1, and B2 RNAs) increases during cellular stress such as viral infection in some cancer cells where they may similarly regulate global changes to gene expression. The ability of Alu and B2 RNA to bind directly to RNAP II provides a broad mechanism to repress transcription. Nevertheless, there are specific exceptions to this global response where Alu or B2 RNAs are not found at activated promoters of genes undergoing induction, such as the heat shock genes. This additional hierarchy of regulation that exempts individual genes from the generalised repression also involves a long ncRNA, heat shock RNA-1 (HSR-1). It was argued that HSR-1 is present in mammalian cells in an inactive state, but upon stress is activated to induce the expression of heat shock genes | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA The authors found that this activation involves a conformational alteration to the structure of HSR-1 in response to rising temperatures, thereby permitting its interaction with the transcriptional activator HSF-1 that subsequently undergoes trimerisation and induces the expression of heat shock genes. In the broad sense, these examples illustrate a regulatory circuit nested within ncRNAs whereby Alu or B2 RNAs repress general gene expression, while other ncRNAs activate the expression of specific genes. Many of the ncRNAs that interact with general transcription factors or RNAP II itself (including 7SK, Alu and B1 and B2 RNAs) are transcribed by RNAP III, thereby uncoupling the expression of these ncRNAs from the RNAP II transcriptional reaction they regulate. RNAP III also transcribes a number of additional novel ncRNAs, such as BC2, BC200 and some microRNAs and snoRNAs, in addition to the highly expressed infrastructural ‘housekeeping’ ncRNA genes such as tRNAs, 5S rRNAs and snRNAs. The existence of an RNAP III-dependent ncRNA transcriptome that regulates its RNAP II-dependent counterpart was supported by a recent study that described a novel set of ncRNAs transcribed by RNAP III with sequence homology to protein-coding genes. This prompted the authors to posit a ‘cogene/gene’ functional regulatory network, showing that one of these ncRNAs, 21A, regulates the expression of its antisense partner gene, CENP-F in trans | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA In addition to regulating transcription, ncRNAs also control various aspects of post-transcriptional mRNA processing. Similar to small regulatory RNAs such as microRNAs and snoRNAs, these functions often involve complementary base pairing with the target mRNA. The formation of RNA duplexes between complementary ncRNA and mRNA may mask key elements within the mRNA required to bind trans-acting factors, potentially affecting any step in post-transcriptional gene expression including pre-mRNA processing and splicing, transport, translation, and degradation. The splicing of mRNA can induce its translation and functionally diversify the repertoire of proteins it encodes. The Zeb2 mRNA, which has a particularly long 5’UTR, requires the retention of a 5’UTR intron that contains an internal ribosome entry site for efficient translation. However, retention of the intron is dependent on the expression of an antisense transcript that complements the intronic 5’ splice site. Therefore, the ectopic expression of the antisense transcript represses splicing and induces translation of the Zeb2 mRNA during mesenchymal development. Likewise, the expression of an overlapping antisense Rev-ErbAa2 transcript controls the alternative splicing of the thyroid hormone receptor ErbAa2 mRNA to form two antagonistic isoforms | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA NcRNA may also apply additional regulatory pressures during translation, a property particularly exploited in neurons where the dendritic or axonal translation of mRNA in response to synaptic activity contributes to changes in synaptic plasticity and the remodelling of neuronal networks. The RNAP III transcribed BC1 and BC200 ncRNAs, that previously derived from tRNAs, are expressed in the mouse and human central nervous system, respectively. BC1 expression is induced in response to synaptic activity and synaptogenesis and is specifically targeted to dendrites in neurons. Sequence complementarity between BC1 and regions of various neuron-specific mRNAs also suggest a role for BC1 in targeted translational repression. Indeed, it was recently shown that BC1 is associated with translational repression in dendrites to control the efficiency of dopamine D2 receptor-mediated transmission in the striatum and BC1 RNA-deleted mice exhibit behavioural changes with reduced exploration and increased anxiety. In addition to masking key elements within single-stranded RNA, the formation of double-stranded RNA duplexes can also provide a substrate for the generation of endogenous siRNAs (endo-siRNAs) in Drosophila and mouse oocytes. The annealing of complementary sequences, such as antisense or repetitive regions between transcripts, forms an RNA duplex that may be processed by Dicer-2 into endo-siRNAs | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Also, long ncRNAs that form extended intramolecular hairpins may be processed into siRNAs, compellingly illustrated by the esi-1 and esi-2 transcripts. Endo-siRNAs generated from these transcripts seem particularly useful in suppressing the spread of mobile transposon elements within the genome in the germline. However, the generation of endo-siRNAs from antisense transcripts or pseudogenes may also silence the expression of their functional counterparts via RISC effector complexes, acting as an important node that integrates various modes of long and short RNA regulation, as exemplified by the Xist and Tsix (see above). Epigenetic modifications, including histone and DNA methylation, histone acetylation and sumoylation, affect many aspects of chromosomal biology, primarily including regulation of large numbers of genes by remodeling broad chromatin domains. While it has been known for some time that RNA is an integral component of chromatin, it is only recently that we are beginning to appreciate the means by which RNA is involved in pathways of chromatin modification. For example, Oplr16 epigenetically induces the activation of stem cell core factors by coordinating intrachromosomal looping and recruitment of DNA demethylase TET2. In Drosophila, long ncRNAs induce the expression of the homeotic gene, Ubx, by recruiting and directing the chromatin modifying functions of the trithorax protein Ash1 to Hox regulatory elements | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Similar models have been proposed in mammals, where strong epigenetic mechanisms are thought to underlie the embryonic expression profiles of the Hox genes that persist throughout human development. Indeed, the human Hox genes are associated with hundreds of ncRNAs that are sequentially expressed along both the spatial and temporal axes of human development and define chromatin domains of differential histone methylation and RNA polymerase accessibility. One ncRNA, termed HOTAIR, that originates from the HOXC locus represses transcription across 40 kb of the HOXD locus by altering chromatin trimethylation state. HOTAIR is thought to achieve this by directing the action of Polycomb chromatin remodeling complexes in trans to govern the cells' epigenetic state and subsequent gene expression. Components of the Polycomb complex, including Suz12, EZH2 and EED, contain RNA binding domains that may potentially bind HOTAIR and probably other similar ncRNAs. This example nicely illustrates a broader theme whereby ncRNAs recruit the function of a generic suite of chromatin modifying proteins to specific genomic loci, underscoring the complexity of recently published genomic maps. Indeed, the prevalence of long ncRNAs associated with protein coding genes may contribute to localised patterns of chromatin modifications that regulate gene expression during development | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA For example, the majority of protein-coding genes have antisense partners, including many tumour suppressor genes that are frequently silenced by epigenetic mechanisms in cancer. A recent study observed an inverse expression profile of the p15 gene and an antisense ncRNA in leukaemia. A detailed analysis showed the p15 antisense ncRNA (CDKN2BAS) was able to induce changes to heterochromatin and DNA methylation status of p15 by an unknown mechanism, thereby regulating p15 expression. Therefore, misexpression of the associated antisense ncRNAs may subsequently silence the tumour suppressor gene contributing towards cancer. Many emergent themes of ncRNA-directed chromatin modification were first apparent within the phenomenon of imprinting, whereby only one allele of a gene is expressed from either the maternal or the paternal chromosome. In general, imprinted genes are clustered together on chromosomes, suggesting the imprinting mechanism acts upon local chromosome domains rather than individual genes. These clusters are also often associated with long ncRNAs whose expression is correlated with the repression of the linked protein-coding gene on the same allele. Indeed, detailed analysis has revealed a crucial role for the ncRNAs Kcnqot1 and Igf2r/Air in directing imprinting. Almost all the genes at the Kcnq1 loci are maternally inherited, except the paternally expressed antisense ncRNA Kcnqot1 | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Transgenic mice with truncated Kcnq1ot fail to silence the adjacent genes, suggesting that Kcnqot1 is crucial to the imprinting of genes on the paternal chromosome. It appears that Kcnqot1 is able to direct the trimethylation of lysine 9 (H3K9me3) and 27 of histone 3 (H3K27me3) to an imprinting centre that overlaps the Kcnqot1 promoter and actually resides within a Kcnq1 sense exon. Similar to HOTAIR (see above), Eed-Ezh2 Polycomb complexes are recruited to the Kcnq1 loci paternal chromosome, possibly by Kcnqot1, where they may mediate gene silencing through repressive histone methylation. A differentially methylated imprinting centre also overlaps the promoter of a long antisense ncRNA Air that is responsible for the silencing of neighbouring genes at the Igf2r locus on the paternal chromosome. The presence of allele-specific histone methylation at the Igf2r locus suggests Air also mediates silencing via chromatin modification. The inactivation of a X-chromosome in female placental mammals is directed by one of the earliest and best characterized long ncRNAs, Xist. The expression of Xist from the future inactive X-chromosome, and its subsequent coating of the inactive X-chromosome, occurs during early embryonic stem cell differentiation | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Xist expression is followed by irreversible layers of chromatin modifications that include the loss of the histone (H3K9) acetylation and H3K4 methylation that are associated with active chromatin, and the induction of repressive chromatin modifications including H4 hypoacetylation, H3K27 trimethylation, H3K9 hypermethylation and H4K20 monomethylation as well as H2AK119 monoubiquitylation. These modifications coincide with the transcriptional silencing of the X-linked genes. Xist RNA also localises the histone variant macroH2A to the inactive X–chromosome. There are additional ncRNAs that are also present at the Xist loci, including an antisense transcript Tsix, which is expressed from the future active chromosome and able to repress Xist expression by the generation of endogenous siRNA. Together these ncRNAs ensure that only one X-chromosome is active in female mammals. Telomeres form the terminal region of mammalian chromosomes and are essential for stability and aging and play central roles in diseases such as cancer. Telomeres have been long considered transcriptionally inert DNA-protein complexes until it was shown in the late 2000s that telomeric repeats may be transcribed as telomeric RNAs (TelRNAs) or telomeric repeat-containing RNAs. These ncRNAs are heterogeneous in length, transcribed from several sub-telomeric loci and physically localise to telomeres | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Their association with chromatin, which suggests an involvement in regulating telomere specific heterochromatin modifications, is repressed by SMG proteins that protect chromosome ends from telomere loss. In addition, TelRNAs block telomerase activity in vitro and may therefore regulate telomerase activity. Although early, these studies suggest an involvement for telomeric ncRNAs in various aspects of telomere biology. Recent recognition that long ncRNAs function in various aspects of cell biology has focused increasing attention on their potential to contribute towards disease etiology. More than 80% (1502 among 1867 lncRNAs in LncBook) experimentally studied lncRNAs have been reported to be associated with 462 diseases and 28 MeSH disease terms, and 97,998 lncRNAs are potentially associated with diseases based on the multi-omics evidence. A handful of studies have implicated long ncRNAs in a variety of disease states and support an involvement and co-operation in neurological disease and cancer. The first published report of an alteration in lncRNA abundance in aging and human neurological disease was provided by Lukiw et al. in a study using short post-mortem interval Alzheimer's disease and non-Alzheimer's dementia (NAD) tissues; this early work was based on the prior identification of a primate brain-specific cytoplasmic transcript of the Alu repeat family by Watson and Sutcliffe in 1987 known as BC200 (brain, cytoplasmic, 200 nucleotide) | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA While many association studies have identified unusual expression of long ncRNAs in disease states, there is little understanding of their role in causing disease. Expression analyses that compare tumor cells and normal cells have revealed changes in the expression of ncRNAs in several forms of cancer. For example, in prostate tumours, PCGEM1 (one of two overexpressed ncRNAs) is correlated with increased proliferation and colony formation suggesting an involvement in regulating cell growth. MALAT1 (also known as NEAT2) was originally identified as an abundantly expressed ncRNA that is upregulated during metastasis of early-stage non-small cell lung cancer and its overexpression is an early prognostic marker for poor patient survival rates. More recently, the highly conserved mouse homologue of MALAT1 was found to be highly expressed in hepatocellular carcinoma. Intronic antisense ncRNAs with expression correlated to the degree of tumor differentiation in prostate cancer samples have also been reported. Despite a number of long ncRNAs having aberrant expression in cancer, their function and potential role in tumourogenesis is relatively unknown. For example, the ncRNAs HIS-1 and BIC have been implicated in cancer development and growth control, but their function in normal cells is unknown. In addition to cancer, ncRNAs also exhibit aberrant expression in other disease states | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Overexpression of PRINS is associated with psoriasis susceptibility, with PRINS expression being elevated in the uninvolved epidermis of psoriatic patients compared with both psoriatic lesions and healthy epidermis. Genome-wide profiling revealed that many transcribed non-coding ultraconserved regions exhibit distinct profiles in various human cancer states. An analysis of chronic lymphocytic leukaemia, colorectal carcinoma and hepatocellular carcinoma found that all three cancers exhibited aberrant expression profiles for ultraconserved ncRNAs relative to normal cells. Further analysis of one ultraconserved ncRNA suggested it behaved like an oncogene by mitigating apoptosis and subsequently expanding the number of malignant cells in colorectal cancers. Many of these transcribed ultraconserved sites that exhibit distinct signatures in cancer are found at fragile sites and genomic regions associated with cancer. It seems likely that the aberrant expression of these ultraconserved ncRNAs within malignant processes results from important functions they fulfil in normal human development. Recently, a number of association studies examining single nucleotide polymorphisms (SNPs) associated with disease states have been mapped to long ncRNAs. For example, SNPs that identified a susceptibility locus for myocardial infarction mapped to a long ncRNA, MIAT (myocardial infarction associated transcript) | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA Likewise, genome-wide association studies identified a region associated with coronary artery disease that encompassed a long ncRNA, ANRIL. ANRIL is expressed in tissues and cell types affected by atherosclerosis and its altered expression is associated with a high-risk haplotype for coronary artery disease. The complexity of the transcriptome, and our evolving understanding of its structure may inform a reinterpretation of the functional basis for many natural polymorphisms associated with disease states. Many SNPs associated with certain disease conditions are found within non-coding regions and the complex networks of non-coding transcription within these regions make it particularly difficult to elucidate the functional effects of polymorphisms. For example, a SNP both within the truncated form of ZFAT and the promoter of an antisense transcript increases the expression of ZFAT not through increasing the mRNA stability, but rather by repressing the expression of the antisense transcript. The ability of long ncRNAs to regulate associated protein-coding genes may contribute to disease if misexpression of a long ncRNA deregulates a protein coding gene with clinical significance | https://en.wikipedia.org/wiki?curid=16770101 |
Long non-coding RNA In similar manner, an antisense long ncRNA that regulates the expression of the sense BACE1 gene, a crucial enzyme in Alzheimer’s disease etiology, exhibits elevated expression in several regions of the brain in individuals with Alzheimer's disease Alteration of the expression of ncRNAs may also mediate changes at an epigenetic level to affect gene expression and contribute to disease aetiology. For example, the induction of an antisense transcript by a genetic mutation led to DNA methylation and silencing of sense genes, causing ß-thalassemia in a patient. | https://en.wikipedia.org/wiki?curid=16770101 |
Echea An echea, or "sounding vase" (literally "echoer"), is a pot, chamber or vessel that is similar in function to a modern-day bass trap. They were supposedly used in ancient Greek theaters to enhance the voices of performers through resonance, though no archaeological evidence has been found. They were typically made of bronze, but were also made of earthenware for economic reasons. The vessels mentioned by Vitruvius in his "Ten Books on Architecture" are made of bronze and designed specifically for each unique theater. They were then placed in niches between the theater's seats, specifically so that nothing was touching them. They used mathematical calculations to decide where they should be placed. "They should be set upside down, and be supported on the side facing the stage by wedges not less than half a foot high." Both their use in Roman times and usefulness have been debated. Thomas Noble Howe wrote in his commentary on Vitruvius' "Ten Books on Architecture", "These vessels, bronze or clay, may be another example of Vitruvius singling out a highly technical feature of Greek architecture that was uncommon, but between eight and sixteen potential sites with evidence of echea have been identified. It is debatable whether such vessels amplified or deadened sound." were used with a, "due regard to the laws and harmony of physics," according to Roman writer Vitruvius | https://en.wikipedia.org/wiki?curid=16773331 |
Echea The vases operated by resonance, enhancing key frequencies of the performers' voices and absorbing those of the audience, which altered the sound in the theater to make the performers' voices clearer and more lush. The size and shape of a theater determined the number of echea used, and their positioning within it. There is the possibility that echea were not used at all, as they may have never existed. Brill states that, "It is possible that Vitruvius, following the teachings on harmony by Aristoxenus, took speculation for reality." Vitruvius mentions a man named Lucius Mummius, who destroyed the theater of Corinth. He then brought the remains of the building's bronze echeas back to Rome. After selling the fragments, Mummius used the money to make a dedicatory offering at the temple of Luna. Similar devices were used in early churches. Some were discovered in the vaulted ceiling of the choir of Strasbourg Cathedral, as well as in mosques dating to the 11th century. In a city park in Syracuse, Italy, artist Michele Spanghero built the "Aeolica" in 2015. This fiberglass and steel sound sculpture is based on the ancient echea "to create a connection to the ancient history of the land as if it leads an echo from afar." The permanent installation is interactive, encouraging viewers to use it as a listening device. | https://en.wikipedia.org/wiki?curid=16773331 |
Enki Catena ("Enki" from the Assyro-Babylonian principal water god of the Apsu, and "catena" from Latin meaning "chain") is a crater chain on Ganymede measuring long. This chain of 13 craters was probably formed by a comet which was pulled into pieces by Jupiter's gravity as it passed too close to the planet. Soon after this breakup, the 13 fragments crashed onto Ganymede in rapid succession. The Enki craters formed across the sharp boundary between areas of bright terrain and dark terrain, delimited by a thin trough running diagonally across the center of this image. The ejecta deposit surrounding the craters appears very bright on the bright terrain. Even though all the craters formed nearly simultaneously, it is difficult to discern any ejecta deposit on the dark terrain. This may be because the impacts excavated and mixed dark material into the ejecta and the resulting mix is not apparent against the dark background. | https://en.wikipedia.org/wiki?curid=16773798 |
Gula (crater) Gula is a crater on Ganymede. It is a fresh crater with a distinctive central peak. It is about 40 km (25 miles) in diameter. A characteristic feature of both Gula and its southern neighbor Achelous, almost identical in size, is the "pedestal" − an outward-facing, relatively gently sloped scarp that terminates the continuous ejecta blanket. Similar features may be seen in ejecta blankets of Martian craters, suggesting impacts into a volatile (ice)-rich target material. Furthermore, both craters appear crisp and feature terraces. Gula has a prominent central peak; Achelous instead may show the remnant of a collapsed central peak or a central pit that is not fully formed. On lower-resolution images taken under higher sun illumination angle, both craters are shown to have extended bright rays, especially Achelous, which demonstrates that these two craters are younger than the respective surrounding landscape. | https://en.wikipedia.org/wiki?curid=16773915 |
Achelous (crater) Achelous is a relatively fresh crater on Ganymede adjacent to the similarly sized Gula. It has an outer lobate ejecta deposit extending about a crater radius from the rim. A characteristic feature of both craters, almost identical in size, is the "pedestal" - an outward-facing, relatively gently sloped scarp that terminates the continuous ejecta blanket. Similar features may be seen in ejecta blankets of Martian craters, suggesting impacts into a volatile (ice)-rich target material. Furthermore, both craters appear crisp and feature terraces. Gula has a prominent central peak; Achelous instead may show the remnant of a collapsed central peak or a central pit that is not fully formed. On lower-resolution images taken under higher sun illumination angle, both craters are shown to have extended bright rays, especially Achelous, which demonstrates that these two craters are younger than the respective surrounding landscape. | https://en.wikipedia.org/wiki?curid=16773926 |
Galileo Regio is a large, dark surface feature on Jupiter's moon Ganymede. It is a region of ancient dark material that has been broken apart by tectonism and is now surrounded by younger, brighter material (such as that of Uruk Sulcus) that has been upwelling from Ganymede's interior. It is thought to be some 4 billion years old and is heavily cratered and palimpsested, but also has a unique distribution of furrows and smooth terrain that has been the subject of conflicting speculation regarding cause or origin. The distribution of smooth terrain on suggests that the ancient crust of Ganymede was relatively thin in the equatorial region and thickened poleward in this area. The age relationships, morphology, and geometry of the furrow systems do not favor an origin by impact or tidal stressing. A possible, but speculative, origin is crustal uplift caused by a plume-like convection cell in a fluid mantle underlying a thin crust. Stratigraphic and morphologic relationships among furrows and crater palimpsests suggest that palimpsest morphology is largely the result of impact into a rheologically weak crust rather than viscous relaxation. The regio is bounded on the southwest by Uruk Sulcus, which lies between it and Marius Regio. Within itself lies the palimpsest Memphis Facula, a relic of an impact crater that has been flattened in a manner characteristic of some of the Solar System bodies with icy crusts. | https://en.wikipedia.org/wiki?curid=16774007 |
Reflectin Reflectins are a family of intrinsically disordered proteins evolved by a certain number of cephalopods including "Euprymna scolopes" and "Doryteuthis opalescens" to produce iridescent camouflage and signaling. The recently identified protein family is enriched in aromatic and sulfur-containing amino acids, and is utilized by certain cephalopods to refract incident light in their environment. It is possible that reflectins are beta barrel type proteins. It is present in the iridophores and leucophores of cephalopods. There is evidence that the reflectin gene appeared in cephalopods due to a horizontal gene transfer with the marine bioluminescent bacterium, "Aliivibrio fischeri". | https://en.wikipedia.org/wiki?curid=16774174 |
Fluting (geology) Fluting is a process of differential weathering and erosion by which an exposed well-jointed coarse-grained rock such as granite or gneiss, develops a corrugated surface of flutes; especially the formation of small-scale ridges and depressions by wave action. Fluting in glacial geology: Fluting with respect to sedimentary action: | https://en.wikipedia.org/wiki?curid=16774492 |
El (crater) El is a crater on Ganymede. It has a small "pit" in its center. Craters with such a "central pit" are common across Ganymede and are especially intriguing since they may reveal secrets about the structure of the satellite's shallow subsurface. | https://en.wikipedia.org/wiki?curid=16789821 |
Uruk Sulcus is a bright region of grooved terrain adjacent to Galileo Regio on Jupiter's moon Ganymede. It is thought to be younger than the darker material in Galileo Regio and similar regions elsewhere on the moon. | https://en.wikipedia.org/wiki?curid=16790091 |
Interferometric gravitational-wave detector An interferometric gravitational-wave detector (or interferometric gravitational-wave telescope) is a gravitational wave detector that uses the wave interference to detect gravitational waves. Laser interferometers detects gravitational waves that extend and contract the distance between mirrors. Atom interferometers are proposed to detect gravitational waves, which would lengthen or shorten the distance between recombining atom clouds. Interferometric gravitational-wave detectors are one class of detectors and for more information about other types of instruments used for gravitational wave detection see the article on gravitational wave observatories. Interferometric gravitational wave detectors include | https://en.wikipedia.org/wiki?curid=16794043 |
Geroch energy The or Geroch mass is one of the possible definitions of mass in general relativity. It can be derived from the Hawking energy, itself a measure of the bending of ingoing and outgoing rays of light that are orthogonal to a 2-sphere surrounding the region of space whose mass is to be defined, by leaving out certain (positive) terms related to the sphere's external and internal curvature. | https://en.wikipedia.org/wiki?curid=16794316 |
Tikhon Chicherin Tikhon Sergeyevich Chicherin (, ; 1869–1904) was a Russian entomologist who specialised in Coleoptera, especially Carabidae. | https://en.wikipedia.org/wiki?curid=16794409 |
Vortex state The vortex state is a thermodynamic state of a material, characterized by co-existing resistive and superconducting sub-regions which form cores roughly 300 nm across. It is the state transitioned to by Type II superconductors when an external magnetic field first overcomes the Meissner current at the material's boundary. It is still possible for material in the vortex state to be superconductive as long as the cores remain relatively stationary and/or there is a superconducting path through the material. | https://en.wikipedia.org/wiki?curid=16796574 |
Oleg Leonidovich Kryzhanovsky (28 May 1918, Ekaterinburg – 15 June 1997) was a Russian entomologist who specialised in Coleoptera especially Carabidae and Histeridae. Kryzhanovsky published more than 250 scientific works including 6 monographs (for list see External Link). He described 135 new species of beetles. | https://en.wikipedia.org/wiki?curid=16798655 |
Isabella (crater) Crater Isabella is the second largest impact crater on Venus. The feature is named in honor of the 15th Century queen of Spain, Isabella I of Castile. Located at 30 degrees south latitude, 204 degrees east longitude, the crater has two extensive flow-like structures extending to the south and to the southeast. The end of the southern flow partially surrounds a pre-existing circular volcanic shield. The southeastern flow shows a complex pattern of channels and flow lobes, and is overlain at its southeastern tip by deposits from a later diameter impact crater, Cohn. The extensive flows, unique to Venusian impact craters, are a continuing subject of study for a number of planetary scientists. It is thought that the flows may consist of 'impact melt,' rock melted by the intense heat released in the impact explosion. An alternate hypothesis invokes 'debris flows,' which may consist of clouds of hot gases and both melted and solid rock fragments that race across the landscape during the impact event. That type of emplacement process is similar to that which occurs in violent eruptions on Earth, such as the 1991 Mount Pinatubo eruption in the Philippines. | https://en.wikipedia.org/wiki?curid=16798987 |
Stefania (crater) Stefania is a crater on Venus in the northern Sedna Planitia. With a diameter of it is one of the smaller craters on Venus . Because many small meteoroids disintegrate during their passage through the dense atmosphere, there is an absence of craters smaller than in diameter, and even craters smaller than are relatively scarce. The apron of ejected material suggests that the impacting body made contact with the surface from an oblique angle. Upon closer observation it is possible to delineate secondary craters, impact scars from blocks ejected from the primary crater. A feature associated with this and many other Venusian craters is a radar-dark halo. Since dark radar return signifies a smooth surface, it has been hypothesized that an intense shock wave removed or pulverized previously rough surface material or that a blanket of fine material was deposited during or after the impact. | https://en.wikipedia.org/wiki?curid=16799131 |
Sachs Patera is a feature on Venus. Defined as a sag-caldera, Sachs is an elliptical depression 130 meters (81 feet) in depth, spanning in width along its longest axis. The morphology implies that a chamber of molten material drained and collapsed, forming a depression surrounded by concentric scarps spaced apart. The arc-shaped set of scarps, extending out to the north from the prominent ellipse, is evidence for a separate episode of withdrawal; the small lobe-shaped extension to the southwest may represent an additional event. Solidified lava flows long give the caldera its flower-like appearance. The flows are a lighter tone of gray in the radar data because the lava is blockier in texture and consequently returns more radar waves. Much of the lava, which was evacuated from the chamber, probably traveled to other locations underground, while some of it may have surfaced further south. This is unlike calderas on Earth, where a rim of lava builds up in the immediate vicinity of the caldera. | https://en.wikipedia.org/wiki?curid=16799934 |
Jeanne (crater) Jeanne is an impact crater on Venus. The distinctive triangular shape of the ejecta indicates that the impacting body probably hit obliquely, traveling from southwest to northeast. The crater is surrounded by dark material of two types. The dark area on the southwest side of the crater is covered by smooth (radar-dark) lava flows which have a strongly digitate contact with surrounding brighter flows. The very dark area on the northeast side of the crater is probably covered by smooth material such as fine-grained sediment. This dark halo is asymmetric, mimicking the asymmetric shape of the ejecta blanket. The dark halo may have been caused by an atmospheric shock or pressure wave produced by the incoming body. Jeanne crater also displays several outflow lobes on the northwest side. These flow-like features may have formed by fine-grained ejecta transported by a hot, turbulent flow created by the arrival of the impacting object. Alternatively, they may have formed by flow of impact melt. | https://en.wikipedia.org/wiki?curid=16800030 |
Sacajawea Patera is a large, elongate caldera located in Western Ishtar Terra on the smooth plateau of Lakshmi Planum, on the planet Venus. The image is centred at 64.5 degrees North latitude and 337 degrees East longitude. It is approximately wide at the base. Sacajawea is a depression approximately 1–2 kilometres (0.6–1.2 miles) deep and 120 x 215 kilometres (74 x 133 miles) in diameter; it is elongate in a southwest-northeast direction. The depression is bounded by a zone of circumferential curvilinear structures interpreted to be graben and fault scarps. These structures are spaced 0.5–4 kilometers (0.3–2.5 miles) apart, are 0.6–4.0 kilometers (0.4–2.5 miles) in width and up to in length. Extending up to approximately in length from the southeast of the patera is a system of linear structures thought to represent a flanking rift zone along which the lateral injection and eruption of magma may have occurred. A shield edifice in diameter with a prominent central pit lies along the trend of one of these features. The impact crater Zlata, approximately in diameter is located within the zone of graben to the northwest of the patera. Few flow features are observed in association with Sacajawea, possibly due to age and state of degradation of the flows. Mottled bright deposits 4–20 kilometers (2.5–12 miles) in width are located near the periphery and in the center of the patera floor within local topographic lows | https://en.wikipedia.org/wiki?curid=16800117 |
Sacajawea Patera Diffuse patches of dark material approximately in width are observed southwest of the patera, superposed on portions of the surrounding graben. The formation of Sacajawea is thought to be related to the drainage and collapse of a large magma chamber. Gravitational relaxation may have caused the resultant caldera to sag, producing the numerous faults and graben that circumscribe the patera. Regions of complex, highly deformed tessera-like terrain are located north and east of the patera and are seen in the upper portion of the image. | https://en.wikipedia.org/wiki?curid=16800117 |
Buck (crater) Buck is a crater in the Navka region of Venus. It has the terraced walls, flat radar-dark floor, and central peak that are characteristic of craters classified as "complex". The central peak on its floor is unusually large. Flow-like deposits extend beyond the limits of the coarser rim deposits on its west and southwest. Like about half of the craters mapped by "Magellan" to date, it is surrounded by a local, radar-dark halo. | https://en.wikipedia.org/wiki?curid=16800222 |
Fotla Corona is a diameter feature on Nsomeka Planitia, Venus. presents a variety of tectonic structures, including three farra of decreasing size from north to south (the largest in the north has a diameter of about 35 km) aligned along a line that intersects the corona in its part West. A rather complex fracture network is visible to the northeast, which among other volcanic structures are visible, probably due to effusion of lava through existing fractures, leading to the collapse of land located above. A set of volcanic domes aligned with the southern part of the circumference of the corona is visible, and a smooth land area in the center of the formation, perhaps the recent lava. These observations highlight the central role of volcanism in the genesis of coronae. | https://en.wikipedia.org/wiki?curid=16804874 |
Aurelia (crater) Aurelia is a crater on Venus. It has a large dark surface up range from the crater; lobate flows emanating from crater ejecta, and very radar-bright ejecta and floor. The crater takes its name from Aurelia. | https://en.wikipedia.org/wiki?curid=16804983 |
Siddons Patera is a volcanic caldera on Venus surrounded by collapsed lava tubes. | https://en.wikipedia.org/wiki?curid=16805039 |
Akna Montes are a mountain range on Venus centered at 68.9°N, 318.2°E and stretching 830 km long. The Akna range is a north-south trending ridge belt that forms the western border of the elevated smooth plateau of Lakshmi Planum. The Lakshmi plateau plains are formed by extensive volcanic eruptions and are bounded by mountain chains on all sides. The plains appear to be deformed near the mountains. This suggests that some of the mountain building activity occurred after the plains formed. | https://en.wikipedia.org/wiki?curid=16805206 |
Wanda (crater) Wanda is a crater in the Akna Montes on Venus first mapped first by the Soviet Venera 15/16 mission in 1984. It was formed by the impact of an asteroid. The crater has a rugged central peak and a smooth radar-dark floor, probably volcanic material. The crater does not appear to be much deformed by later crustal movement that uplifted the mountains and crumpled the plains. Material from the adjacent mountain ridge to the west, however, appears to have collapsed into the crater. Small pits seen to the north of the crater may be volcanic collapse pits a few kilometers across (1–2 miles). | https://en.wikipedia.org/wiki?curid=16805235 |
Riley (crater) Riley is a crater on Venus. The crater is in diameter. The floor of the crater is 580 metres (1,914 feet) below the plains surrounding the crater. The crater's rim rises 620 metres (2,046 feet) above the plains and 1,200 metres (3,960 feet) above the crater floor. The crater's central peak is 536 metres (1,769 feet) high. The crater's diameter is 40 times the depth resulting in a relatively shallow appearance. | https://en.wikipedia.org/wiki?curid=16805281 |
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