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Jean Antoine Dours (22 March 1824 in Bagnères de Bigorre – 29 July 1874 in Amiens) was a French entomologist specialising in Hymenoptera. Excepting the material he acquired from Joseph-Étienne Giraud which was returned to that entomologist, Dours collection was burned in a fire in the U.S.A. | https://en.wikipedia.org/wiki?curid=12291448 |
Johann Friedrich Jaennicke (7 January 1831 in Frankfurt a. M. – 1 April 1907 in Mainz) was a German "Regierungsrat" and entomologist mainly interested in Diptera. Jaennicke's collection is in Senckenberg Museum | https://en.wikipedia.org/wiki?curid=12292243 |
Hampson–Linde cycle The is a process for the liquefaction of gases, especially for air separation. William Hampson and Carl von Linde independently filed for patents of the cycle in 1895: Hampson on 23 May 1895 and Linde on 5 June 1895. The introduced regenerative cooling, a positive-feedback cooling system. The heat exchanger arrangement permits an absolute temperature difference (e.g. J–T cooling for air) to go beyond a single stage of cooling and can reach the low temperatures required to liquefy "fixed" gases. The differs from the Siemens cycle only in the expansion step. Whereas the Siemens cycle has the gas do external work to reduce its temperature, the relies solely on the Joule–Thomson effect; this has the advantage that the cold side of the cooling apparatus needs no moving parts. The cooling cycle proceeds in several steps: In each cycle the net cooling is more than the heat added at the beginning of the cycle. As the gas passes more cycles and becomes cooler, reaching lower temperatures at the expansion valve becomes more difficult. | https://en.wikipedia.org/wiki?curid=12295288 |
F number (chemistry) F number is a correlation number used in the analysis of polycyclic aromatic hydrocarbons (PAHs) as a descriptor of their hydrophobicity and molecular size. It was proposed by Robert Hurtubise and co-workers in 1977. The F number is calculated using the formula: where: For fluorene, there are 6 apparent double bonds (three pi bonds in each side benzene-like ring); the central ring has one secondary carbon and is non-aromatic. Therefore: It has been found that the F number linearly correlates with the log k' value (logarithm of the retention factor) in aqueous reversed-phase liquid chromatography. This relationship can be used to understand the significance of different aspects of molecular architecture on their separation using different stationary phases. This size analysis is complementary to the length-to-breadth (L/B) ratio, which classifies molecules according to their "rodlike" or "squarelike" shape. | https://en.wikipedia.org/wiki?curid=12295512 |
Evolutionary history of life The evolutionary history of life on Earth traces the processes by which living and fossil organisms evolved, from the earliest emergence of life to the present. Earth formed about 4.5 billion years (Ga) ago and evidence suggests life emerged prior to 3.7 Ga. (Although there is some evidence of life as early as 4.1 to 4.28 Ga, it remains controversial due to the possible non-biological formation of the purported fossils.) The similarities among all known present-day species indicate that they have diverged through the process of evolution from a common ancestor. Approximately 1 trillion species currently live on Earth of which only 1.75–1.8 million have been named and 1.6 million documented in a central database. These currently living species represent less than one percent of all species that have ever lived on earth. The earliest evidence of life comes from biogenic carbon signatures and stromatolite fossils discovered in 3.7 billion-year-old metasedimentary rocks from western Greenland. In 2015, possible "remains of biotic life" were found in 4.1 billion-year-old rocks in Western Australia. In March 2017, putative evidence of possibly the oldest forms of life on Earth was reported in the form of fossilized microorganisms discovered in hydrothermal vent precipitates in the Nuvvuagittuq Belt of Quebec, Canada, that may have lived as early as 4.28 billion years ago, not long after the oceans formed 4.4 billion years ago, and not long after the formation of the Earth 4.54 billion years ago | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Microbial mats of coexisting bacteria and archaea were the dominant form of life in the early Archean Epoch and many of the major steps in early evolution are thought to have taken place in this environment. The evolution of photosynthesis, around 3.5 Ga, eventually led to a buildup of its waste product, oxygen, in the atmosphere, leading to the great oxygenation event, beginning around 2.4 Ga. The earliest evidence of eukaryotes (complex cells with organelles) dates from 1.85 Ga, and while they may have been present earlier, their diversification accelerated when they started using oxygen in their metabolism. Later, around 1.7 Ga, multicellular organisms began to appear, with differentiated cells performing specialised functions. Sexual reproduction, which involves the fusion of male and female reproductive cells (gametes) to create a zygote in a process called fertilization is, in contrast to asexual reproduction, the primary method of reproduction for the vast majority of macroscopic organisms, including almost all eukaryotes (which includes animals and plants). However the origin and evolution of sexual reproduction remain a puzzle for biologists though it did evolve from a common ancestor that was a single celled eukaryotic species. Bilateria, animals having a left and a right side that are mirror images of each other, appeared by 555 Ma (million years ago) | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The earliest complex land plants date back to around 850 Ma, from carbon isotopes in Precambrian rocks, while algae-like multicellular land plants are dated back even to about 1 billion years ago, although evidence suggests that microorganisms formed the earliest terrestrial ecosystems, at least 2.7 Ga. Microorganisms are thought to have paved the way for the inception of land plants in the Ordovician. Land plants were so successful that they are thought to have contributed to the Late Devonian extinction event. (The long causal chain implied seems to involve the success of early tree archaeopteris (1) drew down CO levels, leading to global cooling and lowered sea levels, (2) roots of archeopteris fostered soil development which "increased" rock weathering, and the subsequent nutrient run-off may have triggered algal blooms resulting in anoxic events which caused marine-life die-offs. Marine species were the primary victims of the Late Devonian extinction.) Ediacara biota appear during the Ediacaran period, while vertebrates, along with most other modern phyla originated about during the Cambrian explosion. During the Permian period, synapsids, including the ancestors of mammals, dominated the land, but most of this group became extinct in the Permian–Triassic extinction event . During the recovery from this catastrophe, archosaurs became the most abundant land vertebrates; one archosaur group, the dinosaurs, dominated the Jurassic and Cretaceous periods | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life After the Cretaceous–Paleogene extinction event killed off the non-avian dinosaurs, mammals increased rapidly in size and diversity. Such mass extinctions may have accelerated evolution by providing opportunities for new groups of organisms to diversify. The oldest meteorite fragments found on Earth are about 4.54 billion years old; this, coupled primarily with the dating of ancient lead deposits, has put the estimated age of Earth at around that time. The Moon has the same composition as Earth's crust but does not contain an iron-rich core like the Earth's. Many scientists think that about 40 million years after the formation of Earth, it collided with a body the size of Mars, throwing into orbit crust material that formed the Moon. Another hypothesis is that the Earth and Moon started to coalesce at the same time but the Earth, having much stronger gravity than the early Moon, attracted almost all the iron particles in the area. Until 2001, the oldest rocks found on Earth were about 3.8 billion years old, leading scientists to estimate that the Earth's surface had been molten until then. Accordingly, they named this part of Earth's history the Hadean. However, analysis of zircons formed 4.4 Ga indicates that Earth's crust solidified about 100 million years after the planet's formation and that the planet quickly acquired oceans and an atmosphere, which may have been capable of supporting life. Evidence from the Moon indicates that from 4 to 3 | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life 8 Ga it suffered a Late Heavy Bombardment by debris that was left over from the formation of the Solar System, and the Earth should have experienced an even heavier bombardment due to its stronger gravity. While there is no direct evidence of conditions on Earth 4 to 3.8 Ga, there is no reason to think that the Earth was not also affected by this late heavy bombardment. This event may well have stripped away any previous atmosphere and oceans; in this case gases and water from comet impacts may have contributed to their replacement, although outgassing from volcanoes on Earth would have supplied at least half. However, if subsurface microbial life had evolved by this point, it would have survived the bombardment. The earliest identified organisms were minute and relatively featureless, and their fossils look like small rods that are very difficult to tell apart from structures that arise through abiotic physical processes. The oldest undisputed evidence of life on Earth, interpreted as fossilized bacteria, dates to 3 Ga. Other finds in rocks dated to about 3.5 Ga have been interpreted as bacteria, with geochemical evidence also seeming to show the presence of life 3.8 Ga. However, these analyses were closely scrutinized, and non-biological processes were found which could produce all of the "signatures of life" that had been reported. While this does not prove that the structures found had a non-biological origin, they cannot be taken as clear evidence for the presence of life | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Geochemical signatures from rocks deposited 3.4 Ga have been interpreted as evidence for life, although these statements have not been thoroughly examined by critics. Evidence for fossilized microorganisms considered to be 3.77 billion to 4.28 billion years old was found in the Nuvvuagittuq Greenstone Belt in Quebec, Canada, although the evidence is disputed as inconclusive. Biologists reason that all living organisms on Earth must share a single last universal ancestor, because it would be virtually impossible that two or more separate lineages could have independently developed the many complex biochemical mechanisms common to all living organisms. Life on Earth is based on carbon and water. Carbon provides stable frameworks for complex chemicals and can be easily extracted from the environment, especially from carbon dioxide. There is no other chemical element whose properties are similar enough to carbon's to be called an analogue; silicon, the element directly below carbon on the periodic table, does not form very many complex stable molecules, and because most of its compounds are water-insoluble and because silicon dioxide is a hard and abrasive solid in contrast to carbon dioxide at temperatures associated with living things, it would be more difficult for organisms to extract. The elements boron and phosphorus have more complex chemistries, but suffer from other limitations relative to carbon | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Water is an excellent solvent and has two other useful properties: the fact that ice floats enables aquatic organisms to survive beneath it in winter; and its molecules have electrically negative and positive ends, which enables it to form a wider range of compounds than other solvents can. Other good solvents, such as ammonia, are liquid only at such low temperatures that chemical reactions may be too slow to sustain life, and lack water's other advantages. Organisms based on alternative biochemistry may, however, be possible on other planets. Research on how life might have emerged from non-living chemicals focuses on three possible starting points: self-replication, an organism's ability to produce offspring that are very similar to itself; metabolism, its ability to feed and repair itself; and external cell membranes, which allow food to enter and waste products to leave, but exclude unwanted substances. Research on abiogenesis still has a long way to go, since theoretical and empirical approaches are only beginning to make contact with each other. Even the simplest members of the three modern domains of life use DNA to record their "recipes" and a complex array of RNA and protein molecules to "read" these instructions and use them for growth, maintenance and self-replication. The discovery that some RNA molecules can catalyze both their own replication and the construction of proteins led to the hypothesis of earlier life-forms based entirely on RNA | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life These ribozymes could have formed an RNA world in which there were individuals but no species, as mutations and horizontal gene transfers would have meant that the offspring in each generation were quite likely to have different genomes from those that their parents started with. RNA would later have been replaced by DNA, which is more stable and therefore can build longer genomes, expanding the range of capabilities a single organism can have. Ribozymes remain as the main components of ribosomes, modern cells' "protein factories." Evidence suggests the first RNA molecules formed on Earth prior to 4.17 Ga. Although short self-replicating RNA molecules have been artificially produced in laboratories, doubts have been raised about whether natural non-biological synthesis of RNA is possible. The earliest "ribozymes" may have been formed of simpler nucleic acids such as PNA, TNA or GNA, which would have been replaced later by RNA. In 2003, it was proposed that porous metal sulfide precipitates would assist RNA synthesis at about and ocean-bottom pressures near hydrothermal vents. Under this hypothesis, lipid membranes would be the last major cell components to appear and, until then, the protocells would be confined to the pores. A series of experiments starting in 1997 showed that early stages in the formation of proteins from inorganic materials including carbon monoxide and hydrogen sulfide could be achieved by using iron sulfide and nickel sulfide as catalysts | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Most of the steps required temperatures of about and moderate pressures, although one stage required and a pressure equivalent to that found under of rock. Hence it was suggested that self-sustaining synthesis of proteins could have occurred near hydrothermal vents. It has been suggested that double-walled "bubbles" of lipids like those that form the external membranes of cells may have been an essential first step. Experiments that simulated the conditions of the early Earth have reported the formation of lipids, and these can spontaneously form liposomes, double-walled "bubbles," and then reproduce themselves. Although they are not intrinsically information-carriers as nucleic acids are, they would be subject to natural selection for longevity and reproduction. Nucleic acids such as RNA might then have formed more easily within the liposomes than they would have outside. RNA is complex and there are doubts about whether it can be produced non-biologically in the wild. Some clays, notably montmorillonite, have properties that make them plausible accelerators for the emergence of an RNA world: they grow by self-replication of their crystalline pattern; they are subject to an analog of natural selection, as the clay "species" that grows fastest in a particular environment rapidly becomes dominant; and they can catalyze the formation of RNA molecules. Although this idea has not become the scientific consensus, it still has active supporters | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Research in 2003 reported that montmorillonite could also accelerate the conversion of fatty acids into "bubbles," and that the "bubbles" could encapsulate RNA attached to the clay. These "bubbles" can then grow by absorbing additional lipids and then divide. The formation of the earliest cells may have been aided by similar processes. A similar hypothesis presents self-replicating iron-rich clays as the progenitors of nucleotides, lipids and amino acids. The Panspermia hypothesis does not explain how life arose in the first place, but simply examines the possibility of it coming from somewhere other than the Earth. The idea that life on Earth was "seeded" from elsewhere in the Universe dates back at least to the Greek philosopher Anaximander in the sixth century BCE. In the twentieth century it was proposed by the physical chemist Svante Arrhenius, by the astronomers Fred Hoyle and Chandra Wickramasinghe, and by molecular biologist Francis Crick and chemist Leslie Orgel. There are three main versions of the "seeded from elsewhere" hypothesis: from elsewhere in our Solar System via fragments knocked into space by a large meteor impact, in which case the most credible sources are Mars and Venus; by alien visitors, possibly as a result of accidental contamination by microorganisms that they brought with them; and from outside the Solar System but by natural means | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Experiments in low Earth orbit, such as EXOSTACK, demonstrated that some microorganism spores can survive the shock of being catapulted into space and some can survive exposure to outer space radiation for at least 5.7 years. Scientists are divided over the likelihood of life arising independently on Mars, or on other planets in our galaxy. Microbial mats are multi-layered, multi-species colonies of bacteria and other organisms that are generally only a few millimeters thick, but still contain a wide range of chemical environments, each of which favors a different set of microorganisms. To some extent each mat forms its own food chain, as the by-products of each group of microorganisms generally serve as "food" for adjacent groups. Stromatolites are stubby pillars built as microorganisms in mats slowly migrate upwards to avoid being smothered by sediment deposited on them by water. There has been vigorous debate about the validity of alleged fossils from before 3 Ga, with critics arguing that so-called stromatolites could have been formed by non-biological processes. In 2006, another find of stromatolites was reported from the same part of Australia as previous ones, in rocks dated to 3.5 Ga. In modern underwater mats the top layer often consists of photosynthesizing cyanobacteria which create an oxygen-rich environment, while the bottom layer is oxygen-free and often dominated by hydrogen sulfide emitted by the organisms living there | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life It is estimated that the appearance of oxygenic photosynthesis by bacteria in mats increased biological productivity by a factor of between 100 and 1,000. The reducing agent used by oxygenic photosynthesis is water, which is much more plentiful than the geologically produced reducing agents required by the earlier non-oxygenic photosynthesis. From this point onwards life itself produced significantly more of the resources it needed than did geochemical processes. Oxygen is toxic to organisms that are not adapted to it, but greatly increases the metabolic efficiency of oxygen-adapted organisms. Oxygen became a significant component of Earth's atmosphere about 2.4 Ga. Although eukaryotes may have been present much earlier, the oxygenation of the atmosphere was a prerequisite for the evolution of the most complex eukaryotic cells, from which all multicellular organisms are built. The boundary between oxygen-rich and oxygen-free layers in microbial mats would have moved upwards when photosynthesis shut down overnight, and then downwards as it resumed on the next day. This would have created selection pressure for organisms in this intermediate zone to acquire the ability to tolerate and then to use oxygen, possibly via endosymbiosis, where one organism lives inside another and both of them benefit from their association. Cyanobacteria have the most complete biochemical "toolkits" of all the mat-forming organisms | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Hence they are the most self-sufficient of the mat organisms and were well-adapted to strike out on their own both as floating mats and as the first of the phytoplankton, providing the basis of most marine food chains. Eukaryotes may have been present long before the oxygenation of the atmosphere, but most modern eukaryotes require oxygen, which their mitochondria use to fuel the production of ATP, the internal energy supply of all known cells. In the 1970s it was proposed and, after much debate, widely accepted that eukaryotes emerged as a result of a sequence of endosymbiosis between prokaryotes. For example: a predatory microorganism invaded a large prokaryote, probably an archaean, but the attack was neutralized, and the attacker took up residence and evolved into the first of the mitochondria; one of these chimeras later tried to swallow a photosynthesizing cyanobacterium, but the victim survived inside the attacker and the new combination became the ancestor of plants; and so on. After each endosymbiosis began, the partners would have eliminated unproductive duplication of genetic functions by re-arranging their genomes, a process which sometimes involved transfer of genes between them. Another hypothesis proposes that mitochondria were originally sulfur- or hydrogen-metabolising endosymbionts, and became oxygen-consumers later. On the other hand, mitochondria might have been part of eukaryotes' original equipment | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life There is a debate about when eukaryotes first appeared: the presence of steranes in Australian shales may indicate that eukaryotes were present 2.7 Ga; however, an analysis in 2008 concluded that these chemicals infiltrated the rocks less than 2.2 Ga and prove nothing about the origins of eukaryotes. Fossils of the algae "Grypania" have been reported in 1.85 billion-year-old rocks (originally dated to 2.1 Ga but later revised), and indicates that eukaryotes with organelles had already evolved. A diverse collection of fossil algae were found in rocks dated between 1.5 and 1.4 Ga. The earliest known fossils of fungi date from 1.43 Ga. Plastids, the superclass of organelles of which chloroplasts are the best-known exemplar, are thought to have originated from endosymbiotic cyanobacteria. The symbiosis evolved around 1.5 Ga and enabled eukaryotes to carry out oxygenic photosynthesis. Three evolutionary lineages have since emerged in which the plastids are named differently: chloroplasts in green algae and plants, rhodoplasts in red algae and cyanelles in the glaucophytes. The defining characteristics of sexual reproduction in eukaryotes are meiosis and fertilization. There is much genetic recombination in this kind of reproduction, in which offspring receive 50% of their genes from each parent, in contrast with asexual reproduction, in which there is no recombination | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Bacteria also exchange DNA by bacterial conjugation, the benefits of which include resistance to antibiotics and other toxins, and the ability to utilize new metabolites. However, conjugation is not a means of reproduction, and is not limited to members of the same species – there are cases where bacteria transfer DNA to plants and animals. On the other hand, bacterial transformation is clearly an adaptation for transfer of DNA between bacteria of the same species. Bacterial transformation is a complex process involving the products of numerous bacterial genes and can be regarded as a bacterial form of sex. This process occurs naturally in at least 67 prokaryotic species (in seven different phyla). Sexual reproduction in eukaryotes may have evolved from bacterial transformation. (Also see Evolution of sexual reproduction#Origin of sexual reproduction.) The disadvantages of sexual reproduction are well-known: the genetic reshuffle of recombination may break up favorable combinations of genes; and since males do not directly increase the number of offspring in the next generation, an asexual population can out-breed and displace in as little as 50 generations a sexual population that is equal in every other respect. Nevertheless, the great majority of animals, plants, fungi and protists reproduce sexually. There is strong evidence that sexual reproduction arose early in the history of eukaryotes and that the genes controlling it have changed very little since then | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life How sexual reproduction evolved and survived is an unsolved puzzle. The Red Queen hypothesis suggests that sexual reproduction provides protection against parasites, because it is easier for parasites to evolve means of overcoming the defenses of genetically identical clones than those of sexual species that present moving targets, and there is some experimental evidence for this. However, there is still doubt about whether it would explain the survival of sexual species if multiple similar clone species were present, as one of the clones may survive the attacks of parasites for long enough to out-breed the sexual species. Furthermore, contrary to the expectations of the Red Queen hypothesis, Kathryn A. Hanley et al. found that the prevalence, abundance and mean intensity of mites was significantly higher in sexual geckos than in asexuals sharing the same habitat. In addition, biologist Matthew Parker, after reviewing numerous genetic studies on plant disease resistance, failed to find a single example consistent with the concept that pathogens are the primary selective agent responsible for sexual reproduction in the host. Alexey Kondrashov's "deterministic mutation hypothesis" (DMH) assumes that each organism has more than one harmful mutation and the combined effects of these mutations are more harmful than the sum of the harm done by each individual mutation | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life If so, sexual recombination of genes will reduce the harm that bad mutations do to offspring and at the same time eliminate some bad mutations from the gene pool by isolating them in individuals that perish quickly because they have an above-average number of bad mutations. However, the evidence suggests that the DMH's assumptions are shaky because many species have on average less than one harmful mutation per individual and no species that has been investigated shows evidence of synergy between harmful mutations. (Further criticisms of this hypothesis are discussed in the article Evolution of sexual reproduction#Removal of deleterious genes) The random nature of recombination causes the relative abundance of alternative traits to vary from one generation to another. This genetic drift is insufficient on its own to make sexual reproduction advantageous, but a combination of genetic drift and natural selection may be sufficient. When chance produces combinations of good traits, natural selection gives a large advantage to lineages in which these traits become genetically linked. On the other hand, the benefits of good traits are neutralized if they appear along with bad traits. Sexual recombination gives good traits the opportunities to become linked with other good traits, and mathematical models suggest this may be more than enough to offset the disadvantages of sexual reproduction. Other combinations of hypotheses that are inadequate on their own are also being examined | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The adaptive function of sex today remains a major unresolved issue in biology. The competing models to explain the adaptive function of sex were reviewed by John A. Birdsell and Christopher Wills. The hypotheses discussed above all depend on the possible beneficial effects of random genetic variation produced by genetic recombination. An alternative view is that sex arose and is maintained, as a process for repairing DNA damage, and that the genetic variation produced is an occasionally beneficial byproduct. The simplest definitions of "multicellular," for example "having multiple cells," could include colonial cyanobacteria like "Nostoc". Even a technical definition such as "having the same genome but different types of cell" would still include some genera of the green algae Volvox, which have cells that specialize in reproduction. Multicellularity evolved independently in organisms as diverse as sponges and other animals, fungi, plants, brown algae, cyanobacteria, slime molds and myxobacteria. For the sake of brevity, this article focuses on the organisms that show the greatest specialization of cells and variety of cell types, although this approach to the evolution of biological complexity could be regarded as "rather anthropocentric | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life " The initial advantages of multicellularity may have included: more efficient sharing of nutrients that are digested outside the cell, increased resistance to predators, many of which attacked by engulfing; the ability to resist currents by attaching to a firm surface; the ability to reach upwards to filter-feed or to obtain sunlight for photosynthesis; the ability to create an internal environment that gives protection against the external one; and even the opportunity for a group of cells to behave "intelligently" by sharing information. These features would also have provided opportunities for other organisms to diversify, by creating more varied environments than flat microbial mats could. Multicellularity with differentiated cells is beneficial to the organism as a whole but disadvantageous from the point of view of individual cells, most of which lose the opportunity to reproduce themselves. In an asexual multicellular organism, rogue cells which retain the ability to reproduce may take over and reduce the organism to a mass of undifferentiated cells. Sexual reproduction eliminates such rogue cells from the next generation and therefore appears to be a prerequisite for complex multicellularity. The available evidence indicates that eukaryotes evolved much earlier but remained inconspicuous until a rapid diversification around 1 Ga | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The only respect in which eukaryotes clearly surpass bacteria and archaea is their capacity for variety of forms, and sexual reproduction enabled eukaryotes to exploit that advantage by producing organisms with multiple cells that differed in form and function. By comparing the composition of transcription factor families and regulatory network motifs between unicellular organisms and multicellular organisms, scientists found there are many novel transcription factor families and three novel types of regulatory network motifs in multicellular organisms, and novel family transcription factors are preferentially wired into these novel network motifs which are essential for multicullular development. These results propose a plausible mechanism for the contribution of novel-family transcription factors and novel network motifs to the origin of multicellular organisms at transcriptional regulatory level. The Francevillian biota fossils, dated to 2.1 Ga, are the earliest known fossil organisms that are clearly multicellular. They may have had differentiated cells. Another early multicellular fossil, "Qingshania", dated to 1.7 Ga, appears to consist of virtually identical cells. The red algae called "Bangiomorpha", dated at 1.2 Ga, is the earliest known organism that certainly has differentiated, specialized cells, and is also the oldest known sexually reproducing organism. The 1.43 billion-year-old fossils interpreted as fungi appear to have been multicellular with differentiated cells | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The "string of beads" organism "Horodyskia", found in rocks dated from 1.5 Ga to 900 Ma, may have been an early metazoan; however, it has also been interpreted as a colonial foraminiferan. Animals are multicellular eukaryotes, and are distinguished from plants, algae, and fungi by lacking cell walls. All animals are motile, if only at certain life stages. All animals except sponges have bodies differentiated into separate tissues, including muscles, which move parts of the animal by contracting, and nerve tissue, which transmits and processes signals. In November 2019, researchers reported the discovery of "Caveasphaera", a multicellular organism found in 609-million-year-old rocks, that is not easily defined as an animal or non-animal, which may be related to one of the earliest instances of animal evolution. Fossil studies of "Caveaspaera" have suggested that animal-like embryonic development arose much earlier than the oldest clearly defined animal fossils. and may be consistent with studies suggesting that animal evolution may have begun about 750 million years ago. Nonetheless, the earliest widely accepted animal fossils are the rather modern-looking cnidarians (the group that includes jellyfish, sea anemones and "Hydra"), possibly from around , although fossils from the Doushantuo Formation can only be dated approximately. Their presence implies that the cnidarian and bilaterian lineages had already diverged | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The Ediacara biota, which flourished for the last 40 million years before the start of the Cambrian, were the first animals more than a very few centimetres long. Many were flat and had a "quilted" appearance, and seemed so strange that there was a proposal to classify them as a separate kingdom, Vendozoa. Others, however, have been interpreted as early molluscs ("Kimberella"), echinoderms ("Arkarua"), and arthropods ("Spriggina", "Parvancorina"). There is still debate about the classification of these specimens, mainly because the diagnostic features which allow taxonomists to classify more recent organisms, such as similarities to living organisms, are generally absent in the Ediacarans. However, there seems little doubt that "Kimberella" was at least a triploblastic bilaterian animal, in other words, an animal significantly more complex than the cnidarians. The small shelly fauna are a very mixed collection of fossils found between the Late Ediacaran and Middle Cambrian periods. The earliest, "Cloudina", shows signs of successful defense against predation and may indicate the start of an evolutionary arms race. Some tiny Early Cambrian shells almost certainly belonged to molluscs, while the owners of some "armor plates," "Halkieria" and "Microdictyon", were eventually identified when more complete specimens were found in Cambrian lagerstätten that preserved soft-bodied animals | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life In the 1970s there was already a debate about whether the emergence of the modern phyla was "explosive" or gradual but hidden by the shortage of Precambrian animal fossils. A re-analysis of fossils from the Burgess Shale lagerstätte increased interest in the issue when it revealed animals, such as "Opabinia", which did not fit into any known phylum. At the time these were interpreted as evidence that the modern phyla had evolved very rapidly in the Cambrian explosion and that the Burgess Shale's "weird wonders" showed that the Early Cambrian was a uniquely experimental period of animal evolution. Later discoveries of similar animals and the development of new theoretical approaches led to the conclusion that many of the "weird wonders" were evolutionary "aunts" or "cousins" of modern groups—for example that "Opabinia" was a member of the lobopods, a group which includes the ancestors of the arthropods, and that it may have been closely related to the modern tardigrades. Nevertheless, there is still much debate about whether the Cambrian explosion was really explosive and, if so, how and why it happened and why it appears unique in the history of animals. Most of the animals at the heart of the Cambrian explosion debate are protostomes, one of the two main groups of complex animals. The other major group, the deuterostomes, contains invertebrates such as starfish and sea urchins (echinoderms), as well as chordates (see below) | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Many echinoderms have hard calcite "shells," which are fairly common from the Early Cambrian small shelly fauna onwards. Other deuterostome groups are soft-bodied, and most of the significant Cambrian deuterostome fossils come from the Chengjiang fauna, a lagerstätte in China. The chordates are another major deuterostome group: animals with a distinct dorsal nerve cord. Chordates include soft-bodied invertebrates such as tunicates as well as vertebrates—animals with a backbone. While tunicate fossils predate the Cambrian explosion, the Chengjiang fossils "Haikouichthys" and "Myllokunmingia" appear to be true vertebrates, and "Haikouichthys" had distinct vertebrae, which may have been slightly mineralized. Vertebrates with jaws, such as the acanthodians, first appeared in the Late Ordovician. Adaptation to life on land is a major challenge: all land organisms need to avoid drying-out and all those above microscopic size must create special structures to withstand gravity; respiration and gas exchange systems have to change; reproductive systems cannot depend on water to carry eggs and sperm towards each other. Although the earliest good evidence of land plants and animals dates back to the Ordovician period (), and a number of microorganism lineages made it onto land much earlier, modern land ecosystems only appeared in the Late Devonian, about . In May 2017, evidence of the earliest known life on land may have been found in 3 | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life 48-billion-year-old geyserite and other related mineral deposits (often found around hot springs and geysers) uncovered in the Pilbara Craton of Western Australia. In July 2018, scientists reported that the earliest life on land may have been bacteria living on land 3.22 billion years ago. In May 2019, scientists reported the discovery of a fossilized fungus, named "Ourasphaira giraldae", in the Canadian Arctic, that may have grown on land a billion years ago, well before plants were living on land. Oxygen is a potent oxidant whose accumulation in terrestrial atmosphere resulted from the development of photosynthesis over 3 Ga, in cyanobacteria (blue-green algae), which were the most primitive oxygenic photosynthetic organisms. Brown algae accumulate inorganic mineral antioxidants such as rubidium, vanadium, zinc, iron, copper, molybdenum, selenium and iodine which is concentrated more than 30,000 times the concentration of this element in seawater. Protective endogenous antioxidant enzymes and exogenous dietary antioxidants helped to prevent oxidative damage. Most marine mineral antioxidants act in the cells as essential trace elements in redox and antioxidant metalloenzymes. When plants and animals began to enter rivers and land about 500 Ma, environmental deficiency of these marine mineral antioxidants was a challenge to the evolution of terrestrial life. Terrestrial plants slowly optimized the production of “new” endogenous antioxidants such as ascorbic acid, polyphenols, flavonoids, tocopherols, etc | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life A few of these appeared more recently, in last 200–50 Ma, in fruits and flowers of angiosperm plants. In fact, angiosperms (the dominant type of plant today) and most of their antioxidant pigments evolved during the Late Jurassic period. Plants employ antioxidants to defend their structures against reactive oxygen species produced during photosynthesis. Animals are exposed to the same oxidants, and they have evolved endogenous enzymatic antioxidant systems. Iodine is the most primitive and abundant electron-rich essential element in the diet of marine and terrestrial organisms, and as iodide acts as an electron donor and has this ancestral antioxidant function in all iodide-concentrating cells from primitive marine algae to more recent terrestrial vertebrates. Before the colonization of land, soil, a combination of mineral particles and decomposed organic matter, did not exist. Land surfaces would have been either bare rock or unstable sand produced by weathering. Water and any nutrients in it would have drained away very quickly. In the Sub-Cambrian peneplain in Sweden for example maximum depth of kaolinitization by Neoproterozoic weathering is about 5 m, in contrast nearby kaolin deposits developed in the Mesozoic are much thicker. It has been argued that in the late Neoproterozoic sheet wash was a dominant process of erosion of surface material due to the lack of plants on land | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Films of cyanobacteria, which are not plants but use the same photosynthesis mechanisms, have been found in modern deserts, and only in areas that are unsuitable for vascular plants. This suggests that microbial mats may have been the first organisms to colonize dry land, possibly in the Precambrian. Mat-forming cyanobacteria could have gradually evolved resistance to desiccation as they spread from the seas to intertidal zones and then to land. Lichens, which are symbiotic combinations of a fungus (almost always an ascomycete) and one or more photosynthesizers (green algae or cyanobacteria), are also important colonizers of lifeless environments, and their ability to break down rocks contributes to soil formation in situations where plants cannot survive. The earliest known ascomycete fossils date from in the Silurian. Soil formation would have been very slow until the appearance of burrowing animals, which mix the mineral and organic components of soil and whose feces are a major source of the organic components. Burrows have been found in Ordovician sediments, and are attributed to annelids ("worms") or arthropods. In aquatic algae, almost all cells are capable of photosynthesis and are nearly independent. Life on land required plants to become internally more complex and specialized: photosynthesis was most efficient at the top; roots were required in order to extract water from the ground; the parts in between became supports and transport systems for water and nutrients | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Spores of land plants, possibly rather like liverworts, have been found in Middle Ordovician rocks dated to about . In Middle Silurian rocks , there are fossils of actual plants including clubmosses such as "Baragwanathia"; most were under high, and some appear closely related to vascular plants, the group that includes trees. By the Late Devonian , trees such as "Archaeopteris" were so abundant that they changed river systems from mostly braided to mostly meandering, because their roots bound the soil firmly. In fact, they caused the "Late Devonian wood crisis" because: Animals had to change their feeding and excretory systems, and most land animals developed internal fertilization of their eggs. The difference in refractive index between water and air required changes in their eyes. On the other hand, in some ways movement and breathing became easier, and the better transmission of high-frequency sounds in air encouraged the development of hearing. The oldest known air-breathing animal is "Pneumodesmus", an archipolypodan millipede from the Middle Silurian, about . Its air-breathing, terrestrial nature is evidenced by the presence of spiracles, the openings to tracheal systems. However, some earlier trace fossils from the Cambrian-Ordovician boundary about are interpreted as the tracks of large amphibious arthropods on coastal sand dunes, and may have been made by euthycarcinoids, which are thought to be evolutionary "aunts" of myriapods | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Other trace fossils from the Late Ordovician a little over probably represent land invertebrates, and there is clear evidence of numerous arthropods on coasts and alluvial plains shortly before the Silurian-Devonian boundary, about , including signs that some arthropods ate plants. Arthropods were well pre-adapted to colonise land, because their existing jointed exoskeletons provided protection against desiccation, support against gravity and a means of locomotion that was not dependent on water. The fossil record of other major invertebrate groups on land is poor: none at all for non-parasitic flatworms, nematodes or nemerteans; some parasitic nematodes have been fossilized in amber; annelid worm fossils are known from the Carboniferous, but they may still have been aquatic animals; the earliest fossils of gastropods on land date from the Late Carboniferous, and this group may have had to wait until leaf litter became abundant enough to provide the moist conditions they need. The earliest confirmed fossils of flying insects date from the Late Carboniferous, but it is thought that insects developed the ability to fly in the Early Carboniferous or even Late Devonian. This gave them a wider range of ecological niches for feeding and breeding, and a means of escape from predators and from unfavorable changes in the environment. About 99% of modern insect species fly or are descendants of flying species | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Tetrapods, vertebrates with four limbs, evolved from other rhipidistian fish over a relatively short timespan during the Late Devonian (). The early groups are grouped together as Labyrinthodontia. They retained aquatic, fry-like tadpoles, a system still seen in modern amphibians. Iodine and T4/T3 stimulate the amphibian metamorphosis and the evolution of nervous systems transforming the aquatic, vegetarian tadpole into a “more evoluted” terrestrial, carnivorous frog with better neurological, visuospatial, olfactory and cognitive abilities for hunting. The new hormonal action of T3 was made possible by the formation of T3-receptors in the cells of vertebrates. Firstly, about 600-500 million years ago, in primitive Chordata appeared the alpha T3-receptors with a metamorphosing action and then, about 250-150 million years ago, in the Birds and Mammalia appeared the beta T3-receptors with metabolic and thermogenetic actions. From the 1950s to the early 1980s it was thought that tetrapods evolved from fish that had already acquired the ability to crawl on land, possibly in order to go from a pool that was drying out to one that was deeper | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life However, in 1987, nearly complete fossils of "Acanthostega" from about showed that this Late Devonian transitional animal had legs and both lungs and gills, but could never have survived on land: its limbs and its wrist and ankle joints were too weak to bear its weight; its ribs were too short to prevent its lungs from being squeezed flat by its weight; its fish-like tail fin would have been damaged by dragging on the ground. The current hypothesis is that "Acanthostega", which was about long, was a wholly aquatic predator that hunted in shallow water. Its skeleton differed from that of most fish, in ways that enabled it to raise its head to breathe air while its body remained submerged, including: its jaws show modifications that would have enabled it to gulp air; the bones at the back of its skull are locked together, providing strong attachment points for muscles that raised its head; the head is not joined to the shoulder girdle and it has a distinct neck | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The Devonian proliferation of land plants may help to explain why air breathing would have been an advantage: leaves falling into streams and rivers would have encouraged the growth of aquatic vegetation; this would have attracted grazing invertebrates and small fish that preyed on them; they would have been attractive prey but the environment was unsuitable for the big marine predatory fish; air-breathing would have been necessary because these waters would have been short of oxygen, since warm water holds less dissolved oxygen than cooler marine water and since the decomposition of vegetation would have used some of the oxygen. Later discoveries revealed earlier transitional forms between "Acanthostega" and completely fish-like animals. Unfortunately, there is then a gap (Romer's gap) of about 30 Ma between the fossils of ancestral tetrapods and Middle Carboniferous fossils of vertebrates that look well-adapted for life on land. Some of these look like early relatives of modern amphibians, most of which need to keep their skins moist and to lay their eggs in water, while others are accepted as early relatives of the amniotes, whose waterproof skin and egg membranes enable them to live and breed far from water. Amniotes, whose eggs can survive in dry environments, probably evolved in the Late Carboniferous period (). The earliest fossils of the two surviving amniote groups, synapsids and sauropsids, date from around | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The synapsid pelycosaurs and their descendants the therapsids are the most common land vertebrates in the best-known Permian () fossil beds. However, at the time these were all in temperate zones at middle latitudes, and there is evidence that hotter, drier environments nearer the Equator were dominated by sauropsids and amphibians. The Permian–Triassic extinction event wiped out almost all land vertebrates, as well as the great majority of other life. During the slow recovery from this catastrophe, estimated to have taken 30 million years, a previously obscure sauropsid group became the most abundant and diverse terrestrial vertebrates: a few fossils of archosauriformes ("ruling lizard forms") have been found in Late Permian rocks, but, by the Middle Triassic, archosaurs were the dominant land vertebrates. Dinosaurs distinguished themselves from other archosaurs in the Late Triassic, and became the dominant land vertebrates of the Jurassic and Cretaceous periods (). During the Late Jurassic, birds evolved from small, predatory theropod dinosaurs. The first birds inherited teeth and long, bony tails from their dinosaur ancestors, but some had developed horny, toothless beaks by the very Late Jurassic and short pygostyle tails by the Early Cretaceous. While the archosaurs and dinosaurs were becoming more dominant in the Triassic, the mammaliaform successors of the therapsids evolved into small, mainly nocturnal insectivores | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life This ecological role may have promoted the evolution of mammals, for example nocturnal life may have accelerated the development of endothermy ("warm-bloodedness") and hair or fur. By in the Early Jurassic there were animals that were very like today's mammals in a number of respects. Unfortunately, there is a gap in the fossil record throughout the Middle Jurassic. However, fossil teeth discovered in Madagascar indicate that the split between the lineage leading to monotremes and the one leading to other living mammals had occurred by . After dominating land vertebrate niches for about 150 Ma, the non-avian dinosaurs perished in the Cretaceous–Paleogene extinction event () along with many other groups of organisms. Mammals throughout the time of the dinosaurs had been restricted to a narrow range of taxa, sizes and shapes, but increased rapidly in size and diversity after the extinction, with bats taking to the air within 13 million years, and cetaceans to the sea within 15 million years. The first flowering plants appeared around 130 Ma. The 250,000 to 400,000 species of flowering plants outnumber all other ground plants combined, and are the dominant vegetation in most terrestrial ecosystems. There is fossil evidence that flowering plants diversified rapidly in the Early Cretaceous, from , and that their rise was associated with that of pollinating insects. Among modern flowering plants "Magnolia" are thought to be close to the common ancestor of the group | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life However, paleontologists have not succeeded in identifying the earliest stages in the evolution of flowering plants. The social insects are remarkable because the great majority of individuals in each colony are sterile. This appears contrary to basic concepts of evolution such as natural selection and the selfish gene. In fact, there are very few eusocial insect species: only 15 out of approximately 2,600 living families of insects contain eusocial species, and it seems that eusociality has evolved independently only 12 times among arthropods, although some eusocial lineages have diversified into several families. Nevertheless, social insects have been spectacularly successful; for example although ants and termites account for only about 2% of known insect species, they form over 50% of the total mass of insects. Their ability to control a territory appears to be the foundation of their success. The sacrifice of breeding opportunities by most individuals has long been explained as a consequence of these species' unusual haplodiploid method of sex determination, which has the paradoxical consequence that two sterile worker daughters of the same queen share more genes with each other than they would with their offspring if they could breed. However, E. O. Wilson and Bert Hölldobler argue that this explanation is faulty: for example, it is based on kin selection, but there is no evidence of nepotism in colonies that have multiple queens | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Instead, they write, eusociality evolves only in species that are under strong pressure from predators and competitors, but in environments where it is possible to build "fortresses"; after colonies have established this security, they gain other advantages through co-operative foraging. In support of this explanation they cite the appearance of eusociality in bathyergid mole rats, which are not haplodiploid. The earliest fossils of insects have been found in Early Devonian rocks from about , which preserve only a few varieties of flightless insect. The Mazon Creek lagerstätten from the Late Carboniferous, about , include about 200 species, some gigantic by modern standards, and indicate that insects had occupied their main modern ecological niches as herbivores, detritivores and insectivores. Social termites and ants first appear in the Early Cretaceous, and advanced social bees have been found in Late Cretaceous rocks but did not become abundant until the Middle Cenozoic. The idea that, along with other life forms, modern-day humans evolved from an ancient, common ancestor was proposed by Robert Chambers in 1844 and taken up by Charles Darwin in 1871. Modern humans evolved from a lineage of upright-walking apes that has been traced back over to "Sahelanthropus". The first known stone tools were made about , apparently by "Australopithecus garhi", and were found near animal bones that bear scratches made by these tools | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life The earliest hominines had chimpanzee-sized brains, but there has been a fourfold increase in the last 3 Ma; a statistical analysis suggests that hominine brain sizes depend almost completely on the date of the fossils, while the species to which they are assigned has only slight influence. There is a long-running debate about whether modern humans evolved all over the world simultaneously from existing advanced hominines or are descendants of a single small population in Africa, which then migrated all over the world less than 200,000 years ago and replaced previous hominine species. There is also debate about whether anatomically modern humans had an intellectual, cultural and technological "Great Leap Forward" under 100,000 years ago and, if so, whether this was due to neurological changes that are not visible in fossils. Life on Earth has suffered occasional mass extinctions at least since . Although they were disasters at the time, mass extinctions have sometimes accelerated the evolution of life on Earth. When dominance of particular ecological niches passes from one group of organisms to another, it is rarely because the new dominant group is "superior" to the old and usually because an extinction event eliminates the old dominant group and makes way for the new one. The fossil record appears to show that the gaps between mass extinctions are becoming longer and the average and background rates of extinction are decreasing | https://en.wikipedia.org/wiki?curid=12305127 |
Evolutionary history of life Both of these phenomena could be explained in one or more ways: Biodiversity in the fossil record, which is "...the number of distinct genera alive at any given time; that is, those whose first occurrence predates and whose last occurrence postdates that time" shows a different trend: a fairly swift rise from ; a slight decline from , in which the devastating Permian–Triassic extinction event is an important factor; and a swift rise from to the present. | https://en.wikipedia.org/wiki?curid=12305127 |
Bulliform cell Bulliform cells or motor cells are large, bubble-shaped epidermal cells that occur in groups on the upper surface of the leaves of many monocots. These cells are present on the adaxial or the upper surface of the leaf. They are generally present near the midvein portion of the leaf and are shown to be large, empty and colourless. They are proposed, though not confirmed, to be involved in folding and unfolding of leaf tissue to control light intensity and reduce overall water loss. The first discussion of bulliform cells occurred in 1909 in the revised and expanded version of the "Plantesamfund" (Oecology of Plants) written by botanist Eugenius Warming for an English audience. One of the features he investigated was the phenomenon of leaf rolling in the Poaceae and Cyperaceae families and how he noticed the bulliform cells, which he termed "hinge-cells", were on the epidermal layer of the leaf tissue, but deeper than the epidermal cells themselves and capable of folding distortion along with the leaf. In the early 1990s, it was suggested by Fahn and Cutler that, at least in grasses, bulliform cells developed as a form of xerophytic adaptation. This was supported by evidence from decades earlier that showed that bulliform cells had larger development in species that lived in a desert ecosystem with a need to control water and salt levels | https://en.wikipedia.org/wiki?curid=12318264 |
Bulliform cell The activity of bulliform cells can be explained as: During drought, the loss of water through vacuoles induces the reduced bulliform cells to allow the leaves of many grass species to close as the two edges of the grass blade fold up toward each other. Once enough water is available, these cells enlarge and the leaves are forced open again. Folded leaves offer less exposure to sunlight, so they are heated less thus reducing evaporation and conserving the remaining water in the plant. Bulliform cells occur on the leaves of a wide variety of monocotyledon families but are probably best known in grasses. They are thought to play a role in the unfolding of developing leaves and in the rolling and unrolling of mature leaves in response to alternating wet and dry periods. It is unclear if this mechanism applies in all monocots, however, or whether other components such as fibers are the pieces controlling the folding and unfolding of the leaf. What is observed is that the turgidity of the bulliform cells often coincide with the folding activity, though there are cases where folding happens long after the cells have gone turgid. | https://en.wikipedia.org/wiki?curid=12318264 |
List of Labes on Mars Labes (plural: "labes") is a Latin word used by exogeologists to refer to chaotic regions, featuring ridges and steep valleys, in the Valles Marineris region of Mars. Labes are named after the nearest classical albedo feature. This is a list of all named labes. Coordinates are given as planetocentric latitude with east longitude. | https://en.wikipedia.org/wiki?curid=12324707 |
Charles Georges Javet (1802 in Winterthur, Kanton Zürich – 25 May 1882 in Passy, Paris) was a Swiss-born French insect dealer and entomologist. He specialised in Coleoptera. Javet was a very active member of the Société entomologique de France or Entomological Society of France. | https://en.wikipedia.org/wiki?curid=12325862 |
Hercules Cluster The (Abell 2151) is a cluster of about 200 galaxies some 500 million light-years distant in the constellation Hercules. It is rich in spiral galaxies and shows many interacting galaxies. The cluster is part of the larger Hercules Supercluster, which is itself part of the much larger Great Wall super-structure. The cluster's brightest member is the giant elliptical galaxy NGC 6041. | https://en.wikipedia.org/wiki?curid=12326315 |
Fast track (FDA) Fast track is a designation by the United States Food and Drug Administration (FDA) of an investigational drug for expedited review to facilitate development of drugs which treat a serious or life-threatening condition and fill an unmet medical need. Fast Track designation must be requested by the drug company. The request can be initiated at any time during the drug development process. FDA will review the request and attempt to make a decision within sixty days. Fast Track is one of five Food and Drug Administration (FDA) approaches to make new drugs available as rapidly as possible: the others are priority review, breakthrough therapy, accelerated approval and Regenerative Medicine Advanced Therapy. Fast Track was introduced by the FDA Modernization Act of 1997. Fast track designation is designed to aid in the development and expedite the review of drugs which show promise in treating a serious or life-threatening disease and address an unmet medical need. Serious Condition: Determining whether a disease is serious is a matter of judgment, but generally is based on whether the drug will affect such factors as survival, day-to-day functioning, or the likelihood that the disease, if left untreated, will progress from a less severe condition to a more serious one. Unmet Medical Need: For a drug to address an unmet medical need, the drug may be developed as a treatment or preventative measure for a disease that does not have a current therapy | https://en.wikipedia.org/wiki?curid=12326459 |
Fast track (FDA) The type of information necessary to demonstrate unmet medical need varies with the stage of drug development: early in development, nonclinical data, mechanistic rationale, or pharmacologic data will suffice; later in development, clinical data should be utilized. If there are existing therapies, a fast track eligible drug must show some advantage over available treatment, such as: A drug that receives Fast Track designation is eligible for some or all of the following: An FDA decision not to grant Fast Track status, or any other general dispute, may be appealed to the division responsible for reviewing the application within the Center for Drug Evaluation and Research. The drug sponsor can subsequently utilize the Agency's procedures for internal review or dispute resolution if necessary. Once a drug receives Fast Track designation, early and frequent communication between the FDA and a drug company is encouraged throughout the entire drug development and review process. The frequency of communication assures that questions and issues are resolved quickly, often leading to earlier drug approval and access by patients. | https://en.wikipedia.org/wiki?curid=12326459 |
FDA Special Protocol Assessment A Special Protocol Assessment (SPA) is an advanced declaration from the Food and Drug Administration that an uncompleted Phase III trial's design, clinical endpoints, and statistical analyses are acceptable for FDA approval. The purpose of a SPA is to allow a company to run or initiate a clinical trial of an experimental drug without fear that the FDA will object to the trial design itself, in the event that the company subsequently applies for product approval. Three types of protocols related to PDUFA products are eligible for this special protocol assessment under the PDUFA goals: The clinical protocols for phase 3 trials can relate to efficacy claims that will be part of an original new drug application (NDA) or Biologic License Application (BLA) or that will be part of an efficacy supplement to an approved NDA or BLA. | https://en.wikipedia.org/wiki?curid=12327567 |
Romulus (comics) Romulus is a fictional comic book supervillain appearing in books published by Marvel Comics, in particular those featuring Wolverine. He is the leader of the Lupines, a species resembling humans that he claims evolved from canines instead of primates through convergent evolution. A shadowy character whose origin and motives remain a mystery, he is shown to have orchestrated most major events in the life of Wolverine, manipulating and controlling him for most of his life. Created by writer Jeph Loeb and artist Simone Bianchi, the character first appeared obscured by shadow in "Wolverine" vol. 3 #50 (March 2007), and made his first full appearance in "" #39 (August 2009). Romulus is first seen in several flashbacks that Wolverine experiences, later explained by Wild Child to have been induced by Romulus himself. He is shown leading the Lupines in prehistoric and barbaric times, being an emperor in Ancient Rome, as well as being the main force behind Weapon X. In the present, Romulus restored Feral and Thornn's feline look after their depowerment on M-Day, augmented Wild Child's powers greatly, and seemed to have erased all humanity from Sabretooth causing the latter's death at the hands of Wolverine (later it was revealed Sabretooth was a clone). Romulus did all of this to reveal himself to Wolverine. Romulus was also the one who took Daken from his dead mother's womb and raised him as a ruthless killer | https://en.wikipedia.org/wiki?curid=12330887 |
Romulus (comics) Nick Fury revealed to Wolverine that Romulus has been manipulating people from his family's bloodline for centuries, and that he plans for Daken to become the next-generation Weapon X. This was achieved through Tinkerer who bonded the metal from the Muramasa blade to Daken's inner claws. Daken hinted he complied with the process because of his own agenda. Romulus told Daken to kill all the Weapon X experiments that gave them a healing factor with his Muramasa claws. He killed every one except Deadpool. He appears to have ties with Russian authorities, arranging Omega Red's transfer to a regular Russian prison to set a trap for Wolverine. After Wolverine temporarily subdues Omega Red, he is captured by Wild Child, who reveals that Romulus made Logan and several villains battle each other, his agenda being vaguely described as him needing a successor. Moments after Wolverine uses the Muramasa blade to kill Omega Red, Romulus reveals himself in front of him, prepared for battle with four claws already extended (the three between the knuckles of his fingers and one extending from behind his thumb). Wolverine attacks Romulus but is easily overpowered since he is only using the sword at this point. Romulus slashes and attacks Wolverine from the shadows as he reveals his plans. Telling Wolverine that everything has led up to this moment. Romulus is what Wolverine will become. Pushing Wolverine to the breaking point, he drops the sword and pops his claws, much to Romulus' amusement | https://en.wikipedia.org/wiki?curid=12330887 |
Romulus (comics) However, Wolverine fights back and gains the upper hand and slashes at Romulus' hand, shattering what turned out to be a clawed gauntlet. Seeing that Romulus' claws are fake, Wolverine taunts him saying, "You're not what I'm gonna become... I'm what you've always wanted to be". Hearing this, Romulus blindly attacks Wolverine with his remaining claws only to be slashed open by Wolverine. Seemingly beaten, Romulus tells Wolverine that although he is at the top of the food chain, by making Daken in his own image, he has set the stage for a confrontation between Wolverine and his son. Only the most ruthless will survive. Only the one most like Romulus. Wolverine defeats Romulus, but leaves him alive saying that he will return when he is ready to finish the job. As Wolverine turns his back, Romulus seizes the opportunity to knock Wolverine unconscious with his own sword. Romulus then leaves, but not before telling Wolverine to keep the Muramasa blade: he will need it. After his confrontation with Wolverine he coordinates a successful assassination in Tokyo from what seems to be his base of operations, a European-style castle. It is here that Romulus first begins to doubt his own understanding of Wolverine's actions. Wolverine decides to confront Romulus one last time, using the help of various other heroes and his son Daken. In the end, as Daken is about to kill Romulus, Logan has Cloak teleport him into the Dark Force dimension | https://en.wikipedia.org/wiki?curid=12330887 |
Romulus (comics) For a second Wolverine thinks he should behead Romulus, just like he did with Creed, but in the end he decides to leave him stranded in the Dark Force dimension. However, thanks to Sabretooth's blackmailing life of Dagger, Romulus gets free from his prison. After a losing fight against Romulus, a mysterious woman with long red hair appears and tells Wolverine that the answers that he seeks are at the Weapon X facility. Following his fight with the Sabretooth clones, the mysterious woman appears to Wolverine again. She calls herself Remus and informs him that Romulus is her twin brother. She aids Wolverine in his struggle against Romulus and Sabretooth all while providing Wolverine with information about Romulus. She reveals to Wolverine that Romulus' claim about certain mutants evolving from canines rather than apes (referring to the Lupine) is untrue which Wolverine had long since guessed. She further reveals that the whole "Lupine Sapiens" story was all just an elaborate hoax by her brother intended to be a ruse for his real goal of creating a master race of natural mutants artificially enhanced by a new type of adamantium created using vibranium illegally mined from Wakanda, using Wolverine as a template. After tracking Romulus to his stronghold somewhere in Italy, Wolverine brutally attacks and incapacitates Sabretooth before confronting Romulus. Wolverine finds Romulus immersed within a tank very similar to the one Wolverine was held in during the days of the Weapon X Program | https://en.wikipedia.org/wiki?curid=12330887 |
Romulus (comics) Wolverine breaks open the tank and savagely assaults Romulus with his claws. He gouges away much of the right side of Romulus' face, revealing that the bones beneath have been bonded with adamantium. As Romulus heals, Wolverine asks what the purpose is of becoming an imitation of him. Romulus declares that he is not as he once was, as he has "taken the best from both Wolverine and Sabretooth", implying that his animal-like powers were artificially copied from Sabretooth (as his twin sister has none of those traits and her only powers shown is a healing-factor). He reveals that he now has four adamantium claws from both his hands in exactly the same configuration he used on the gauntlets he wore. As he launches into his attack, Romulus says to Wolverine that having Romulus erase his memory and bond the adamantium to his skeleton was actually his idea rather than something that he was forced to endure as he's believed for so long (however, this assertion remains ambiguous). Romulus and Wolverine resume their battle with Wolverine ultimately proving victorious, resulting in Romulus being remanded to the Raft. Little is known about the full extent of Romulus's powers. As with Wolverine, Romulus' primary power is an accelerated healing factor that allows him to rapidly regenerate damaged or destroyed tissue with far greater speed and efficiency than normal humans | https://en.wikipedia.org/wiki?curid=12330887 |
Romulus (comics) The full limits of this power aren't known, but he has healed wounds that ripped away the flesh from the right side of his face, exposing the bone, within a matter of seconds. Romulus' healing factor also grants him virtual immunity to known diseases and renders him highly resistant to most forms of drugs. It also affords him greatly extended longevity by slowing his natural aging process to an extraordinary degree as he claims to be tens of thousands of years old. However, Romulus is known to mix exaggeration and half truths in order to perpetuate the mystique surrounding him, though Romulus is ancient. Since the appearance of Remus, she has confirmed that Romulus is at least several thousand years of age. While he does show signs of aging, such as his hair turning almost completely white where it was once black, Romulus still has the same physical vitality and overall appearance of his physical prime. Romulus' senses of sight, smell and hearing are also enhanced to unknown superhuman levels. While they constitute a separate power, their efficiency is still somewhat linked to his healing factor. Romulus also possesses some degree of superhuman strength, the limits of which aren't fully known, though it has been shown as sufficient to lift Wolverine by the arm over his head using one hand and hurl him across a room. Romulus' speed, agility, and reflexes are similarly enhanced | https://en.wikipedia.org/wiki?curid=12330887 |
Romulus (comics) His healing factor grants him partial immunity to the fatigue toxins generated by his muscles during physical activity, so he has much greater stamina and endurance than an ordinary human. He can exert himself physically for at least several hours before the buildup of fatigue toxins in his blood begins to impair him. He also possesses a single, retractable claw at the tip of each finger as well as elongated canine teeth. Romulus' claws are extremely sharp and are capable of cutting most known conventional materials and flesh. Romulus has also displayed some degree of telepathic capabilities during past confrontations with Wolverine. He has been able to enter Wolverine's mind and to manipulate his memories, even going so far as to be able to create false memories or to awaken memories that have been suppressed. However, his telepathic powers are nowhere near the level of Charles Xavier, as Xavier has used his powers to shield Wolverine's mind from Romulus' influence for years. After his return from the Dark Dimension, Romulus underwent the process of bonding adamantium to his skeleton. As a result, his bones are now virtually indestructible. Romulus has also had four adamantium claws implanted into each arm that have the same configuration as the claws mounted onto his gloves. As with his skeleton, these claws are virtually unbreakable and can cut nearly any known substance. Romulus is consistently depicted as being of exceptional stature, surpassing Sabretooth in size | https://en.wikipedia.org/wiki?curid=12330887 |
Romulus (comics) The font used for his words is unique, having a more ancient appearance than those of other characters. Although he often appears naked, he has been shown to wear clothes on several occasions, possibly making use of the fact that only a few living people can recognize him. Romulus has been seen wearing armor over his right knee which has a faint reminder of the adamantium armor worn by Cyber. His facial features are very similar to both Sabretooth and Wolverine. This is seen in his sideburns, canine fangs, pointy ears, and white eyes. His hair is almost solid white with the exception of his bangs, which are black. Romulus has been seen wearing his hair in a long pony tail in a way similar to Omega Red. Romulus also speaks with a unique accent. According to Wolverine, it sounds part Italian and part Japanese. Romulus is extremely intelligent with detailed knowledge of genetics and other areas of science. Romulus also controls a vast criminal empire spread throughout the world and has contacts throughout the criminal underworld. Romulus is also a master manipulator that prefers to work behind the scenes. He is also a formidable hand-to-hand combatant with many thousands of years of experience and knowledge. He also has extensive knowledge of many foreign and ancient cultures as he has alleged to have participated in the rise and fall of many civilizations throughout his existence. | https://en.wikipedia.org/wiki?curid=12330887 |
Maximum parcel level The maximum parcel level (MPL) is the highest level in the atmosphere that a moist convectively rising air parcel will reach after ascending from the level of free convection (LFC) through the free convective layer (FCL) and reaching the equilibrium level (EL), near the tropopause. As the parcel rises through the FCL it expands adiabatically causing its temperature to drop, often below the temperature of its surroundings, and eventually lose buoyancy. Because of this, the EL is approximately the region where the distinct flat tops (called anvil clouds), often observed around the upper portions of cumulonimbus clouds. If the air parcel ascended quickly enough then it retains momentum after it has cooled and continues rising past the EL, ceasing at the MPL (visually represented by the overshooting top, above the anvil). Dynamic processes within and between convective cells, such as updraft merging and cloud base areal size, factor into the actual ultimate cloud top height, in addition to atmospheric thermodynamics of the MPL. Updraft merging can lead to higher cloud tops thus an implication is that organized convection can be taller convection. | https://en.wikipedia.org/wiki?curid=12341831 |
Fernandino Maria Piccioli Ferdinando Maria Piccioli (26 July 1821 – 14 February 1900) was an Italian entomologist. He specialised in Hymenoptera and Coleoptera. Born at San Felice, Piccioli was an “Assistant” at the Stazione di Entomologia Agraria in Florence. He was a member of the founding committee of La Società Entomologica Italiana. Part of his collections of Tuscany Coleoptera are in the Genoa Natural History Museum. The remainder of the Coleoptera and his Hymenoptera, Diptera, Lepidoptera and other Orders are in La Specola museum. He died at Sesto Fiorentino in 1900. | https://en.wikipedia.org/wiki?curid=12342890 |
Anderson orthogonality theorem The is a theorem in physics by the physicist P. W. Anderson. It relates to the introduction of a magnetic impurity in a metal. When a magnetic impurity is introduced into a metal, the conduction electrons will tend to screen the potential formula_1 that the impurity creates. The N-electron ground state for the system when formula_2, which corresponds to the absence of the impurity and formula_3, which corresponds to the introduction of the impurity are orthogonal in the thermodynamic limit formula_4. | https://en.wikipedia.org/wiki?curid=12342942 |
Photoionisation cross section in the context of condensed matter physics refers to the probability of a particle (usually an electron) being emitted from its electronic state. The photoemission is a useful experimental method for the determination and the study of the electronic states. Sometimes the small amount of deposited material over a surface has a weak contribution to the photoemission spectra, which makes its identification very difficult. The knowledge of the cross section of a material can help to detect thin layers or 1D nanowires over a substrate. A right choice of the photon energy can enhance a small amount of material deposited over a surface, otherwise the display of the different spectra won't be possible. | https://en.wikipedia.org/wiki?curid=12356622 |
Ni Wei-tou (; born 1944 in Zhenhai, Ningbo, Zhejiang) is a Taiwanese physicist, who graduated from the Department of Physics of National Taiwan University (NTU), and got his PhD of Physics & Mathematics from California Institute of Technology. After his retirement on 1 October 2000, he is now appointed as a professor emeritus of the Department of Physics of National Tsing Hua University (NTHU) at Hsinchu, Taiwan, since 2006. He is an expert of theoretical and experimental gravitational physics, astrophysics, cosmology, particle physics, and quantum optics etc. He is famous for his alternative theories of gravitation to general relativity, such as Ni (1972), Ni (1973), and Lee, Lightman & Ni (1974). He has been devoted to popular science in Taiwan. | https://en.wikipedia.org/wiki?curid=12369205 |
Harry Frauca (born 14 October 1928) was an Australian naturalist, writer and photographer. Of Catalan origin, he moved to Australia in the 1950s and became an Australian citizen. From 1960 he became a full-time writer and photographer on natural history. From 1970 he collected insects for the Australian National Insect Collection. The last years of his life were spent in Bundaberg, Queensland, with his wife Claudia dying in 1979. He has been honoured in the name of the Walkway, a 200 m walkway at Baldwin Swamp, Bundaberg, as well as the Walking Track and Information Panel at the Mount Walsh National Park, Biggenden. As well as articles in "Walkabout" and elsewhere, books authored or coauthored by Frauca include: | https://en.wikipedia.org/wiki?curid=12374722 |
Leonidas Resvanis Leonidas "Leo" K. Resvanis (; 1944 in Athens, Greece) is a physicist known for his work with neutrinos. He was a Professor of Physics at the University of Athens from 1976 until he retired and became Emeritus Professor in 2011. He served as the director of the Nestor Project. He is also the person who suggested to Burton Richter that Richter's new discovery be named the "psi" particle. received his B.Sc. in Physics from the University of Manchester in 1965. He continue his studies in the Johns Hopkins University from where he received his PhD in High Energy Physics in 1971. His dissertation was entitled "Measurement of the strong interaction form factors in the semileptonic decays of the long lived neutral kaon" Between 1971 and 1976 he worked in the United States, in the University of Pennsylvania as an assistant professor. In 1976 was elected a full Professor in the University of Athens. | https://en.wikipedia.org/wiki?curid=12393209 |
Leopold Anton Kirchner (? - 29 December 1879 Kaplice, Bohemia), sometimes Kirschnerm, was an Austrian physician and entomologist. Kirschner’s medical practice was in Kaplice. He specialised in Hymenoptera (sawflies, wasps, bees, and ants) and Diptera (flies). | https://en.wikipedia.org/wiki?curid=12399983 |
Multiplet A "multiplet" is terminology, often used in physics, for the representation of a mathematical structure, usually an irreducible representation of a Lie group acting as linear operators on a real or complex vector space. In quantum physics, the mathematical notion is usually applied to representations of the gauge group. E.g. an SU(2) gauge theory will have "multiplets" which are fields whose representation of SU(2) is determined by the single half integer number "s", the (iso)"spin" since irreducible SU(2) representations are isomorphic to the "2s"th symmetric power of the fundamental representation, every field has 2s symmetrised "internal indices". Fields are also transforming under representations of the Lorentz group (e.g. in the vector representation) or its spin group SL(2, 'C') (e.g. as Weyl spinors), which give the fields "Lorentz or (confusingly) "spin indices", In quantum field theory different particles correspond one to one with gauged fields transforming in irreducible representations of the internal and Lorentz group. Thus, a multiplet has also come to describe a collection of subatomic particles described by these representations. may also describe a group of related spectral lines. The best known example is a spin multiplet, which describes symmetries of a group representation of an SU(2) subgroup of the Lorentz algebra, which is used to define spin quantization | https://en.wikipedia.org/wiki?curid=12416124 |
Multiplet A spin singlet is a trivial representation, a spin doublet is a fundamental representation and a spin triplet is a vector representation. In QCD, quarks are in a multiplet of SU(3). In seismology, multiplet refers to a repeating earthquake, occurring in nearly the same location, with nearly the same source characteristics. | https://en.wikipedia.org/wiki?curid=12416124 |
Metabolite pool is a collective term for all of the substances involved in the metabolic process in a biological system. Metabolic pools are within cells (or organelles such as chloroplasts) and refer to the reservoir of molecules upon which enzymes can operate. The size of the reservoir is referred to as its "metabolic pool." The metabolic pool concept is important to cellular biology. In certain ways, a metabolic pathway is similar to a factory assembly line. Products are assembled from parts by workers who each perform a specific step in the manufacturing process. Enzymes of a cell are like workers on an assembly line; each is only responsible for a particular step in the assembly process. A lag period also occurs when a new factory is constructed, a time period before finished products begin to roll off the assembly line at a steady rate. This lag period partially results from the time needed to fill supply bins with the necessary parts. As you might imagine, when parts are not readily available, production slows or stops. Metabolite pools are somewhat analogous to the parts bins of a factory. The Calvin-Benson cycle will only operate at full speed when the cellular 'bins' are full of the molecular building blocks that lie between PGA and RUBP. | https://en.wikipedia.org/wiki?curid=12416395 |
Gustav Mayr Gustav L. Mayr (12 October 1830 in Vienna – 14 July 1908 in Vienna) was an Austrian entomologist and professor in Budapest and Vienna. He specialised in Hymenoptera, being particularly known for his studies of Formicidae. In 1868, he was the first to describe the Argentine ant. He is credited with naming the harvesting ant species, "Aphaenogaster treatae", for naturalist Mary Davis Treat in honor of her research on the species. | https://en.wikipedia.org/wiki?curid=12417817 |
Carl von Heyden Carl Heinrich Georg(es) von Heyden (20 January 1793 Frankfurt – 7 July 1866) was a German senator and entomologist. He collected insects in all orders but was especially interested in Coleoptera, Microlepidoptera, Hymenoptera, Diptera and fossil insects. His collections are divided between the German Entomological Institute and the Senckenberg Museum. He studied forestry under Johann Matthäus Bechstein at the Dreißigacker Forest Academy near Meiningen, then continued his education at the University of Heidelberg. With his son, Lukas von Heyden, he conducted studies of fossil insects found in lignite. In addition to his entomological research, he performed investigations of reptile specimens collected by Eduard Rüppell in North Africa. In 1817, he was co-founder of the "Senckenbergischen Naturforschenden Gesellschaft". | https://en.wikipedia.org/wiki?curid=12419087 |
Waldemar Fuchs (died 27 January 1876 in Nepal) was a German entomologist who specialised in Coleoptera. His collection is in La Specola in Florence. | https://en.wikipedia.org/wiki?curid=12419622 |
Wilhelm Mink (1807, Krefeld – 1883) was a German entomologist who specialised in Coleoptera and Hymenoptera . He was a teacher in Krefeld. His collection is in the Städt. Museum Annaberg-Buchholz in Saxony. | https://en.wikipedia.org/wiki?curid=12420471 |
Hermann Rudolph Schaum (29 April 1819 in Glauchau (formerly Glachau) – 15 September 1865 in Bonn) was a professor in Berlin and an entomologist. He specialised in Coleoptera. Up until 1847, he worked as a general practitioner in Stettin, afterwards traveling to England, North America and Egypt, where he accumulated an impressive collection of insects. He later served as a professor of entomology at the University of Berlin. On September 15, 1865, he died in Bonn from consequences of a stroke. The beetle species "Diochus schaumi" is named after him. Schaum was a Member of the Entomological Society of Stettin. | https://en.wikipedia.org/wiki?curid=12420622 |
Plant ontology (PO) is a collection of ontologies developed by the Plant Ontology Consortium. These ontologies describe anatomical structures and growth and developmental stages across Viridiplantae. The PO is intended for multiple applications, including genetics, genomics, phenomics, and development, taxonomy and systematics, semantic applications and education. | https://en.wikipedia.org/wiki?curid=12424857 |
Sven Magnus Aurivillius was a Swedish zoologist born 12 August 1892 in Stockholm and died 4 March 1928 in . He was the director of the centre for marine zoology in Kristineberg in 1923 but left prematurely, just before the publishing of his thesis on Japanese sea fans. He was the eighth generation of his family to be a doctor at the University of Uppsala. His father was the entomologist Per Olof Christopher Aurivillius (1853-1928) and his uncle was the zoologist Carl Wilhelm Samuel Aurivillius (1854-1899). | https://en.wikipedia.org/wiki?curid=12428391 |
Magnetic impurity A magnetic impurity is an impurity in a host metal that has a magnetic moment. The magnetic impurity can then interact with the conduction electrons of the metal, leading to interesting physics such as the Kondo effect, and heavy fermion behaviour. Some examples of magnetic impurities that metals can be doped with are iron and nickel. Such an impurity will contribute a Curie-Weiss term to the magnetic susceptibility, Early theoretical work concentrated on explaining the trend observed as the impurity was varied across the transition metal group. Based on the idea of a virtual bound state, Anderson proposed a model that was successful in explaining the formation of a localized magnetic moment from a magnetic impurity. | https://en.wikipedia.org/wiki?curid=12430286 |
Hermann Reinhard (15 November 1816, Dresden – 10 January 1892) was a German physician and entomologist. He specialised in Hymenoptera (bees and their relatives). Reinhard’s medical practice was in Bautzen. In 1881 he worked with Eduard von Hofmann on the insects of exhumed bodies making him one of the founders of forensic entomology. His collection is in Staatliches Museum für Tierkunde Dresden and Museum für Naturkunde. 321-336. (1862). | https://en.wikipedia.org/wiki?curid=12439476 |
Olav Vadstein (born 14 February 1955) is a Norwegian professor of Microbial Ecology at the Norwegian University of Science and Technology. According to his web page, Vadstein is interested in aquatic ecosystems "both natural and un-natural (human created). Besides basic aspects, I’m interested in applied microbial ecology, which can be placed under the heading Environmental Biotechnology." His most highly cited papers are: | https://en.wikipedia.org/wiki?curid=12449713 |
Johann Angelo Ferrari (1806-18 May 1876, Vienna was an Austrian entomologist born in Italy who specialised in Coleoptera especially Scolytidae He is not to be confused with Pietro Mansueto Ferrari also an entomologist. He wrote "Die Forst- und Baumzuchtschädlichen Borkenkäfer (Tomicides Lac.) aus der Familie der Holzverderber (Scolytides Lac.), mit besonderer Berücksichtigung vorzüglich der europäischen Formen, und der Sammlung der k. k. zoologischen Kabinettes in Wien". Gerolds Sohn, Wien | https://en.wikipedia.org/wiki?curid=12461038 |
Ordoñezite or ordóñezite is a rare tetragonal zinc antimonate mineral with chemical formula: ZnSbO. Ordóñezite was first discovered and documented by Ezequiel Ordóñez (1867-1950), a Mexican geologist, formerly director of the Geological Institute of Mexico. It was first described in 1953 for an occurrence with cassiterite in veins in rhyolite in the Santín mine which is located about eight kilometres from Santa Catarina, Guanajuato, Mexico. Another locality is El Antimonio, southwest of Agua Prieta, Sonora, Mexico. Optical properties include: semitransparent, very light to very dark colorless to pearl-gray, light yellowish olive to dark olive. | https://en.wikipedia.org/wiki?curid=12462866 |
Association of Los Alamos Scientists The (ALAS) was founded on August 30, 1945, by a group of scientists, who had worked on the development of the atomic bomb at the Los Alamos Laboratory, a division of the Manhattan Project. The purpose of the organization was "to promote the attainment and use of scientific and technological advances in the best interests of humanity", according to the manifesto, available in the archives of the University of Chicago. The scientists believed that they, "by virtue of their special knowledge, have, in certain spheres, special political and social responsibilities beyond their obligations as individual citizens". The association sought to carry out these responsibilities by keeping its members informed, "and by providing a forum through which their views can be publicly and authoritatively expressed". The ALAS concentrated its activities principally in promoting international control of nuclear power and directing it to peaceful uses. Its members also attempted to promote responsible uses of science, and the freedom and integrity of scientists and scientific research. The group sponsored public education on the nature and control of atomic energy through lectures, films, and exhibits, and the distribution of literature. It also attempted to influence public policy by means of informed statements to the press and correspondence with high government officials and congressmen. | https://en.wikipedia.org/wiki?curid=12469074 |
Friedrich Kipp (1814 – 21 January 1869) was a German physician and entomologist. Anonym 1869: [Kipp, F.] "Vereinsbl. westph.rhein. Ver. Bienenzucht und Seidenbau" 20:17-18. | https://en.wikipedia.org/wiki?curid=12477399 |
Johann Eusebius Voet Johannes Eusebius Voet (24 January 1706 in Dordrecht – 28 September 1778 in The Hague) was a Dutch physician, poet, illustrator, and entomologist. Johannes was the son of Carel Burchat Voet (1671-1745) who was court-painter to the Earl of Portland and also an entomologist. Voet is the author of "Catalogus Systematicus Coleopterorum". This work, one of the earliest to follow Linnaeus', contains numerous scientific names created by Voet, but fails to fulfill the requirement in the ICZN (Article 11.4) that for scientific names to be available, the entirety of the work in which they appear must be consistently binominal (the standard established by Linnaeus); Voet's names varied from 2 to 5 names in series, thus violating this requirement, so none of Voet's names, even those which happened to be binominal, are available for use in modern scientific literature, though many were later used by other authors who thereby gained official authorship of the names themselves (e.g. "Sternotomis chrysopras"), while other authorities, unaware of the provisions of the ICZN, still occasionally cite Voet as the author. He was also a poet. His debut was "Stichtelyke gedichten en gezangen" (1744), and in 1764 he published a translation of the Psalms. 82 of his translations were included in the official Dutch translation of the Psalms published in 1773. | https://en.wikipedia.org/wiki?curid=12478148 |
Follicle (fruit) In botany, a follicle is a dry unilocular fruit formed from one carpel, containing two or more seeds. It is usually defined as dehiscing by a suture in order to release seeds, for example in "Consolida" (some of the larkspurs), peony and milkweed ("Asclepias"). Some difficult cases exist however, so that the term indehiscent follicle is sometimes used, for example with the genus "Filipendula", which has indehiscent fruits that could be considered intermediate between a (dehiscent) follicle and an (indehiscent) achene. An aggregate fruit that consists of follicles may be called a follicetum. Examples include hellebore, aconite, "Delphinium", "Aquilegia" or the family Crassulaceae, where several follicles occur in a whorl on a shortened receptacle, or "Magnolia", which has many follicles arranged in a spiral on an elongated receptacle. The follicles of some species dehisce by the ventral suture (as in "Banksia"), or by the dorsal suture (as in "Magnolia"). | https://en.wikipedia.org/wiki?curid=12489896 |
Herpolhode A herpolhode is the curve traced out by the endpoint of the angular velocity vector ω of a rigid rotor, a rotating rigid body. The endpoint of the angular velocity moves in a plane in absolute space, called the invariable plane, that is orthogonal to the angular momentum vector L. The fact that the herpolhode is a curve in the invariable plane appears as part of Poinsot's construction. The trajectory of the angular velocity around the angular momentum in the invariable plane is a circle in the case of a symmetric top, but in the general case wiggles inside an annulus, while still being concave towards the angular momentum. H. Goldstein, "Classical Mechanics", Addison-Wesley (1950), p. 159 ff. V. I. Arnold, "Mathematical Methods of Classical Mechanics", Second edition, Springer (1989), p. 146. | https://en.wikipedia.org/wiki?curid=12496940 |
Carbochemistry is the branch of chemistry that studies the transformation of coals (bituminous coal, anthracite, lignite, graphite, and charcoal) into useful products and raw materials. The processes that are used in carbochemistry include degasification processes such as carbonization and coking, gasification processes, and liquefaction processes. The beginning of carbochemistry goes back to the 16th century. At that time, large quantities of charcoal were needed for the smelting of iron ores. Since the production of charcoal required large amounts of slowly-regenerating wood, the use of coal was studied. The use of pure coal was difficult because of the amount of liquid and solid by-products that were generated. In order to improve the handling the coal was initially treated as wood in kilns to produce coke. Around 1684, John Clayton discovered that coal gas generated from coal was combustible. He described his discovery in the "Philosophical Transactions of the Royal Society". | https://en.wikipedia.org/wiki?curid=12510214 |
Geological Society of India The is based in Bangalore, India. Its flagship product is the "Journal of the (JGSI)". As declared in the "JGSI", the Society was established on May 28, 1958 to promote the cause of advanced study and research in all branches of earth system science. The society is administered by a council having a term of three years. The President of the current council is the geologist 'B. P. Radhakrishna' who occasionally writes on pressing science-society issues. The geological society has three classes of membership: Life/Annual Membership; Honorary fellows; Corporate members. The fellows are elected once a year by the council. The society has found the life memberships it offered long ago to be a burden in the sense that life fellows do not have to contribute to the society monetarily but the society has to honour the subscriptions. The society publishes its journal monthly. It also publishes memoirs, textbooks, field guides and an economic geology series, all related to the geology of India. It has a not very high, but respectable, impact factor of 0.424. The journal publishes peer reviewed articles on all aspects of earth science. Most contributions are from India, with a few from neighbouring countries and rarely from outside the continent. But as a reliable source of information on Indian geology it has acquired some repute in geological circles. The present editor is Fareeduddin. The editorial board has B. B. Bhattacharya (Calcutta), D. K. Paul (Calcutta), G. V. R. Prasad (University of Jammu) and M | https://en.wikipedia.org/wiki?curid=12514678 |
Geological Society of India Ramakrishnan (Chennai) as members. | https://en.wikipedia.org/wiki?curid=12514678 |
Soil solarization is a non-chemical environmentally friendly method for controlling pests using solar power to increase the soil temperature to levels at which many soil-borne plant pathogens will be killed or greatly weakened. is used in warm climates on a relatively small scale in gardens and organic farms. weakens and kills fungi, bacteria, nematodes, and insect and mite pests along with weeds in the soil by mulching the soil and covering it with a tarp, usually with a transparent polyethylene cover to trap solar energy. is dependent upon time, temperature, and soil moisture. It may also be described as methods of decontaminating soil or creating suppressive soils by the use of sunlight. This energy causes physical, chemical, and biological changes in the soil community. is a hydrothermal process of disinfecting the soil of pests, accomplished by solar power (referred to as solar heating of the soil in early publications) and is relatively a new soil disinfestation method, first described in extensive scientific detail by Katan in 1976. The mode of action for soil solarization is complex and involves the use of heat as a lethal agent for soil pests from the use of transparent polyethylene tarps. To increase the effectiveness of solar heating requires optimal seasonal temperatures, mulching during high temperatures and solar irradiation, and moisture soil conditions. Soil temperatures are lower when decreasing in soil depth and it is necessary to continue the mulching process to control for pathogens | https://en.wikipedia.org/wiki?curid=12516292 |
Soil solarization practices requires soil temperatures reach 35-60 degrees Celsius, which kills pathogens at the top 30 centimeters of soil. Solarization does not sterilize the soil completely. enhances the soil towards promoting beneficial microorganism. creates a beneficial microbe community by killing up to 90% of pathogens. More specifically, a study reported after eight days of solarization 100% of "V. dabliae" (a fungus that causes farm crops to wilt and die) was killed at a depth of 25 centimeters. does causes a decrease in beneficial microbes, however beneficial bacteria like the "Bacillus" species are able to survive and flourish under high temperatures in solarized soils. Other studies have also reported an increase in "Trichoderma harzianum" (fungicide) after solarization. allows for the recolonization of competitive beneficial microbes by creating a favorable environment conditions. The number of beneficial microbes increases over time and makes solarized soils more resistant to pathogens. The success of solarization is not only due to the decrease in soil pathogens, but also to the increase in beneficial microbes such as "Bacillus", "Pseudomonas", and "Talaromyces flavus". has been shown to suppress soil pathogens and cause an increase in plant growth. Suppressed soils promote rhizobacteria and have shown to increase total dry weight in sugar beets by 3.5 times. Also the study showed that plant growth promoting rhizobacteria on sugar beets treated with soil solarization increased root density by 4.7 times | https://en.wikipedia.org/wiki?curid=12516292 |
Soil solarization is an important agricultural practice for ecologically friendly soil pathogen suppression. A 2008 study used a solar cell to generate an electric field for electrokinetic (EK) remediation of cadmium-contaminated soil. The solar cell could drive the electromigration of cadmium in contaminated soil, and the removal efficiency that was achieved by the solar cell was comparable with that achieved by conventional power supply. In Korea, various remediation methods of soil slurry and groundwater contaminated with benzene at a polluted gas station site were evaluated, including a solar-driven, photocatalyzed reactor system along with various advanced oxidation processes (AOP). The most synergistic remediation method incorporated a solar light process with TiO2 slurry and H2O2 system, achieving 98% benzene degradation, a substantial increase in the removal of benzene. Attempts were made to use solar energy for controlling disease agents in soil and in plant material already in the ancient civilization of India. In 1939, Groashevoy, who used the term "solar energy for sand disinfection," controlled "Thielaviopsis basicola" upon heating the sand by exposure to direct sunlight. is the third approach for soil disinfestation; the two other main approaches, soil steaming and fumigation; were developed at the end of the 19th century. The idea of solarization was based on observations by extension workers and farmers in the hot Jordan Valley, who noticed the intensive heating of the polyethylene-mulched soil | https://en.wikipedia.org/wiki?curid=12516292 |
Soil solarization The involvement of biological control mechanisms in pathogen control and the possible implications were indicated in the first publication, noticing the very long effect of the treatment. In 1977, American scientists from the University of California at Davis reported the control of "Verticillium" in a cotton field, based on studies started in 1976, thus denoting, for the first time, the possible wide applicability of this method. The use of polyethylene for soil solarization differs in principle from its traditional agricultural use. With solarization, soil is mulched during the hottest months (rather than the coldest, as in conventional plasticulture which is aimed at protecting the crop) in order to increase the maximal temperatures in an attempt to achieve lethal heat levels. In the first 10 years following the influential 1976 publication, soil solarization was investigated in at least 24 countries and has been now been applied in more than 50, mostly in the hot regions, although there were some important exceptions. Studies have demonstrated effectiveness of solarization with various crops, including vegetables, field crops, ornamentals and fruit trees, against many pathogens, weeds and a soil arthropod. Those pathogens and weeds which are not controlled by solarization were also detected. The biological, chemical and physical changes that take in solarized soil during and after the solarization have been investigated, as well as the interaction of solarization with other methods of control | https://en.wikipedia.org/wiki?curid=12516292 |
Soil solarization Long-term effects including biological control and increased growth response were verified in various climatic regions and soils, demonstrating the general applicability of solarization. Computerized simulation models have been developed to guide researchers and growers whether the ambient conditions of their locality are suitable for solarization. Studies of the improvement of solarization by integrating it with other methods or by solarizing in closed glasshouses, or studies concerning commercial application by developing mulching machines were also carried out. The use of solarization in existing orchards (e.g. controlling "Verticillium" in pistachio plantations) is an important deviation from the standard preplanting method and was reported as early as 1979. | https://en.wikipedia.org/wiki?curid=12516292 |
Cosmic time is the time coordinate commonly used in the Big Bang models of physical cosmology. Such time coordinate may be defined for a homogeneous, expanding universe so that the universe has the same density everywhere at each moment in time (the fact that this is possible means that the universe is, by definition, homogeneous). The clocks measuring cosmic time should move along the Hubble flow. formula_1 is a measure of time by a physical clock with zero peculiar velocity in the absence of matter over-/under-densities (to prevent time dilation due to relativistic effects or confusions caused by expansion of the universe). Unlike other measures of time such as temperature, redshift, particle horizon, or Hubble horizon, the cosmic time (similar and complementary to the comoving coordinates) is blind to the expansion of the universe. There are two main ways for establishing a reference point for the cosmic time. The most trivial way is to take the present time as the cosmic reference point (sometimes referred to as the lookback time). Alternatively, the Big Bang may be taken as reference to define formula_1 as the age of the universe, also known as time since the big bang. The current physical cosmology estimates the present age as 13.8 billion years. The formula_3 doesn't necessarily have to correspond to a physical event (such as the cosmological singularity) but rather it refers to the point at which the scale factor would vanish for a standard cosmological model such as ΛCDM. For instance, in the case of inflation, i | https://en.wikipedia.org/wiki?curid=12527335 |
Cosmic time e. a non-standard cosmology, the hypothetical moment of big bang is still determined using the benchmark cosmological models which may coincide with the end of the inflationary epoch. For inflationary models, it is not possible to establish a well defined origin of time before the big bang since the universe does not require a beginning event in such models. For technical purposes, concepts such as the average temperature of the universe (in units of eV) or the particle horizon are used when the early universe is the objective of a study since understanding the interaction among particles is more relevant than their time coordinate or age. is the standard time coordinate for specifying the Friedmann–Lemaître–Robertson–Walker solutions of Einstein's equations. | https://en.wikipedia.org/wiki?curid=12527335 |
Gowdy solution Gowdy universes or, alternatively, Gowdy solutions of Einstein's equations are simple model spacetimes in general relativity which represent an expanding universe filled with a regular pattern of gravitational waves. The space-time of an expanding universe is not uniform as in regular space-time, due to the fact that there must always be a singularity (particle) with a velocity vector which travels at the speed of light. In normal, continuous space-time this singularity cannot be realized without a space-time map and this space-time map will always be the same for all possibilities. We have in general relativity an infinite series of universes in different stages of expansion, just like the standard concept of regular space-time. The singularities and the singularity-vortices are the same for all possible universes. Even if we remove all possible universes, we still have at least one infinite series of universes with one singularity and one void. | https://en.wikipedia.org/wiki?curid=12529812 |
Moiety conservation is the conservation of a subgroup in a chemical species, which is cyclically transferred from one molecule to another. Adenosine diphosphate (ADP) is a subgroup that remains unchanged when it is phosphorylated to create adenosine triphosphate (ATP) and then unphosphorylated back to ADP forming a conserved cycle. Moiety-conserved cycles in nature exhibit unique network control features which can be elucidated using techniques such as metabolic control analysis. | https://en.wikipedia.org/wiki?curid=12539451 |
Topological entropy in physics The topological entanglement entropy or "topological entropy", usually denoted by "γ", is a number characterizing many-body states that possess topological order. A non-zero topological entanglement entropy reflects the presence of long range quantum entanglements in a many-body quantum state. So the topological entanglement entropy links topological order with pattern of long range quantum entanglements. Given a topologically ordered state, the topological entropy can be extracted from the asymptotic behavior of the Von Neumann entropy measuring the quantum entanglement between a spatial block and the rest of the system. The entanglement entropy of a simply connected region of boundary length "L", within an infinite two-dimensional topologically ordered state, has the following form for large "L": "-γ" is the topological entanglement entropy. The topological entanglement entropy is equal to the logarithm of the total quantum dimension of the quasiparticle excitations of the state. For example, the simplest fractional quantum Hall states, the Laughlin states at filling fraction 1/"m", have "γ" = ½log("m"). The "Z" fractionalized states, such as topologically ordered states of "Z" spin-liquid, quantum dimer models on non-bipartite lattices, and Kitaev's toric code state, are characterized "γ" = log(2). | https://en.wikipedia.org/wiki?curid=12545981 |
Raster Navigational Charts (NOAA) Raster Navigational Charts (RNC's) are created by the National Oceanic and Atmospheric Administration (NOAA) of the United States Government. Each original chart is scanned at high resolution with color separate overlays. The raster file also contains data that is Geo-referencing; enabling computer based navigation attached to a GPS to locate and display the chart. The charts are stored in BSB format. Image manipulation tools such as GDAL can read the image information, but there also is georeferenced data in the navigational charts. | https://en.wikipedia.org/wiki?curid=12555158 |
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