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Geomorphology Geomorphologists may rely on geochronology, using dating methods to measure the rate of changes to the surface. Terrain measurement techniques are vital to quantitatively describe the form of the Earth's surface, and include differential GPS, remotely sensed digital terrain models and laser scanning, to quantify, study, and to generate illustrations and maps. Practical applications of geomorphology include hazard assessment (such as landslide prediction and mitigation), river control and stream restoration, and coastal protection. Planetary geomorphology studies landforms on other terrestrial planets such as Mars. Indications of effects of wind, fluvial, glacial, mass wasting, meteor impact, tectonics and volcanic processes are studied. This effort not only helps better understand the geologic and atmospheric history of those planets but also extends geomorphological study of the Earth. Planetary geomorphologists often use Earth analogues to aid in their study of surfaces of other planets. Other than some notable exceptions in antiquity, geomorphology is a relatively young science, growing along with interest in other aspects of the earth sciences in the mid-19th century. This section provides a very brief outline of some of the major figures and events in its development. The study of landforms and the evolution of the Earth's surface can be dated back to scholars of Classical Greece | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Herodotus argued from observations of soils that the Nile delta was actively growing into the Mediterranean Sea, and estimated its age. Aristotle speculated that due to sediment transport into the sea, eventually those seas would fill while the land lowered. He claimed that this would mean that land and water would eventually swap places, whereupon the process would begin again in an endless cycle. Another early theory of geomorphology was devised by the polymath Chinese scientist and statesman Shen Kuo (1031–1095). This was based on his observation of marine fossil shells in a geological stratum of a mountain hundreds of miles from the Pacific Ocean. Noticing bivalve shells running in a horizontal span along the cut section of a cliffside, he theorized that the cliff was once the pre-historic location of a seashore that had shifted hundreds of miles over the centuries. He inferred that the land was reshaped and formed by soil erosion of the mountains and by deposition of silt, after observing strange natural erosions of the Taihang Mountains and the Yandang Mountain near Wenzhou. Furthermore, he promoted the theory of gradual climate change over centuries of time once ancient petrified bamboos were found to be preserved underground in the dry, northern climate zone of "Yanzhou", which is now modern day Yan'an, Shaanxi province. The term geomorphology seems to have been first used by Laumann in an 1858 work written in German | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Keith Tinkler has suggested that the word came into general use in English, German and French after John Wesley Powell and W. J. McGee used it during the International Geological Conference of 1891. John Edward Marr in his The Scientific Study of Scenery considered his book as, 'an Introductory Treatise on Geomorphology, a subject which has sprung from the union of Geology and Geography'. An early popular geomorphic model was the "geographical cycle" or "cycle of erosion" model of broad-scale landscape evolution developed by William Morris Davis between 1884 and 1899. It was an elaboration of the uniformitarianism theory that had first been proposed by James Hutton (1726–1797). With regard to valley forms, for example, uniformitarianism posited a sequence in which a river runs through a flat terrain, gradually carving an increasingly deep valley, until the side valleys eventually erode, flattening the terrain again, though at a lower elevation. It was thought that tectonic uplift could then start the cycle over. In the decades following Davis's development of this idea, many of those studying geomorphology sought to fit their findings into this framework, known today as "Davisian". Davis's ideas are of historical importance, but have been largely superseded today, mainly due to their lack of predictive power and qualitative nature. In the 1920s, Walther Penck developed an alternative model to Davis's | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Penck thought that landform evolution was better described as an alternation between ongoing processes of uplift and denudation, as opposed to Davis's model of a single uplift followed by decay. He also emphasised that in many landscapes slope evolution occurs by backwearing of rocks, not by Davisian-style surface lowering, and his science tended to emphasise surface process over understanding in detail the surface history of a given locality. Penck was German, and during his lifetime his ideas were at times rejected vigorously by the English-speaking geomorphology community. His early death, Davis' dislike for his work, and his at-times-confusing writing style likely all contributed to this rejection. Both Davis and Penck were trying to place the study of the evolution of the Earth's surface on a more generalized, globally relevant footing than it had been previously. In the early 19th century, authors – especially in Europe – had tended to attribute the form of landscapes to local climate, and in particular to the specific effects of glaciation and periglacial processes. In contrast, both Davis and Penck were seeking to emphasize the importance of evolution of landscapes through time and the generality of the Earth's surface processes across different landscapes under different conditions. During the early 1900s, the study of regional-scale geomorphology was termed "physiography" | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Physiography later was considered to be a contraction of "physical" and "geography", and therefore synonymous with physical geography, and the concept became embroiled in controversy surrounding the appropriate concerns of that discipline. Some geomorphologists held to a geological basis for physiography and emphasized a concept of physiographic regions while a conflicting trend among geographers was to equate physiography with "pure morphology", separated from its geological heritage. In the period following World War II, the emergence of process, climatic, and quantitative studies led to a preference by many earth scientists for the term "geomorphology" in order to suggest an analytical approach to landscapes rather than a descriptive one. During the age of New Imperialism in the late 19th century European explorers and scientists traveled across the globe bringing descriptions of landscapes and landforms. As geographical knowledge increased over time these observations were systematized in a search for regional patterns. Climate emerged thus as prime factor for explaining landform distribution at a grand scale. The rise of climatic geomorphology was foreshadowed by the work of Wladimir Köppen, Vasily Dokuchaev and Andreas Schimper. William Morris Davis, the leading geomorphologist of his time, recognized the role of climate by complementing his "normal" temperate climate cycle of erosion with arid and glacial ones | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Nevertheless, interest in climatic geomorphology was also a reaction "against" Davisian geomorphology that was by the mid-20th century considered both un-innovative and dubious. Early climatic geomorphology developed primarily in continental Europe while in the English-speaking world the tendency was not explicit until L.C. Peltier's 1950 publication on a periglacial cycle of erosion. Climatic geomorphology was criticized in a 1969 review article by process geomorphologist D.R. Stoddart. The criticism by Stoddart proved "devastating" sparking a decline in the popularity of climatic geomorphology in the late 20th century. Stoddart criticized climatic geomorphology for applying supposedly "trivial" methodologies in establishing landform differences between morphoclimatic zones, being linked to Davisian geomorphology and by allegedly neglecting the fact that physical laws governing processes are the same across the globe. In addition some conceptions of climatic geomorphology, like that which holds that chemical weathering is more rapid in tropical climates than in cold climates proved to not be straightforwardly true. was started to be put on a solid quantitative footing in the middle of the 20th century. Following the early work of Grove Karl Gilbert around the turn of the 20th century, a group of mainly American natural scientists, geologists and hydraulic engineers including William Walden Rubey, Ralph Alger Bagnold, Hans Albert Einstein, Frank Ahnert, John Hack, Luna Leopold, A | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Shields, Thomas Maddock, Arthur Strahler, Stanley Schumm, and Ronald Shreve began to research the form of landscape elements such as rivers and hillslopes by taking systematic, direct, quantitative measurements of aspects of them and investigating the scaling of these measurements.. These methods began to allow prediction of the past and future behavior of landscapes from present observations, and were later to develop into the modern trend of a highly quantitative approach to geomorphic problems. Many groundbreaking and widely cited early geomorphology studies appeared in the Bulletin of the Geological Society of America, and received only few citations prior to 2000 (they are examples of "sleeping beauties") when a marked increase in quantitative geomorphology research occurred. Quantitative geomorphology can involve fluid dynamics and solid mechanics, geomorphometry, laboratory studies, field measurements, theoretical work, and full landscape evolution modeling. These approaches are used to understand weathering and the formation of soils, sediment transport, landscape change, and the interactions between climate, tectonics, erosion, and deposition. In Sweden Filip Hjulström's doctoral thesis, "The River Fyris" (1935), contained one of the first quantitative studies of geomorphological processes ever published | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology His students followed in the same vein, making quantitative studies of mass transport (Anders Rapp), fluvial transport (Åke Sundborg), delta deposition (Valter Axelsson), and coastal processes (John O. Norrman). This developed into "the Uppsala School of Physical Geography". Today, the field of geomorphology encompasses a very wide range of different approaches and interests. Modern researchers aim to draw out quantitative "laws" that govern Earth surface processes, but equally, recognize the uniqueness of each landscape and environment in which these processes operate. Particularly important realizations in contemporary geomorphology include: According to Karna Lidmar-Bergström regional geography is since the 1990s not longer accepted by mainstream scholarship as a basis for geomorphological studies. Albeit having its importance diminished climatic geomorphology continues to exist as field of study producing relevant research. More recently concerns over global warming have led to a renewed interest in the field. Despite considerable criticism the cycle of erosion model has remained part of the science of geomorphology. The model or theory has never been proved wrong, but neither has it been proven. The inherent difficulties of the model have instead made geomorphological research to advance along other lines | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology In contrast to its disputed status in geomorphology, the cycle of erosion model is a common approach used to establish denudation chronologies, and is thus an important concept in the science of historical geology. While acknowledging its shortcomings modern geomorphologists Andrew Goudie and Karna Lidmar-Bergström have praised it for its elegance and pedagogical value respectively. Geomorphically relevant processes generally fall into (1) the production of regolith by weathering and erosion, (2) the transport of that material, and (3) its eventual deposition. Primary surface processes responsible for most topographic features include wind, waves, chemical dissolution, mass wasting, groundwater movement, surface water flow, glacial action, tectonism, and volcanism. Other more exotic geomorphic processes might include periglacial (freeze-thaw) processes, salt-mediated action, changes to the seabed caused by marine currents, seepage of fluids through the seafloor or extraterrestrial impact. Aeolian processes pertain to the activity of the winds and more specifically, to the winds' ability to shape the surface of the Earth. Winds may erode, transport, and deposit materials, and are effective agents in regions with sparse vegetation and a large supply of fine, unconsolidated sediments. Although water and mass flow tend to mobilize more material than wind in most environments, aeolian processes are important in arid environments such as deserts | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology The interaction of living organisms with landforms, or biogeomorphologic processes, can be of many different forms, and is probably of profound importance for the terrestrial geomorphic system as a whole. Biology can influence very many geomorphic processes, ranging from biogeochemical processes controlling chemical weathering, to the influence of mechanical processes like burrowing and tree throw on soil development, to even controlling global erosion rates through modulation of climate through carbon dioxide balance. Terrestrial landscapes in which the role of biology in mediating surface processes can be definitively excluded are extremely rare, but may hold important information for understanding the geomorphology of other planets, such as Mars. Rivers and streams are not only conduits of water, but also of sediment. The water, as it flows over the channel bed, is able to mobilize sediment and transport it downstream, either as bed load, suspended load or dissolved load. The rate of sediment transport depends on the availability of sediment itself and on the river's discharge. Rivers are also capable of eroding into rock and creating new sediment, both from their own beds and also by coupling to the surrounding hillslopes. In this way, rivers are thought of as setting the base level for large-scale landscape evolution in nonglacial environments. Rivers are key links in the connectivity of different landscape elements | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology As rivers flow across the landscape, they generally increase in size, merging with other rivers. The network of rivers thus formed is a drainage system. These systems take on four general patterns: dendritic, radial, rectangular, and trellis. Dendritic happens to be the most common, occurring when the underlying stratum is stable (without faulting). Drainage systems have four primary components: drainage basin, alluvial valley, delta plain, and receiving basin. Some geomorphic examples of fluvial landforms are alluvial fans, oxbow lakes, and fluvial terraces. Glaciers, while geographically restricted, are effective agents of landscape change. The gradual movement of ice down a valley causes abrasion and plucking of the underlying rock. Abrasion produces fine sediment, termed glacial flour. The debris transported by the glacier, when the glacier recedes, is termed a moraine. Glacial erosion is responsible for U-shaped valleys, as opposed to the V-shaped valleys of fluvial origin. The way glacial processes interact with other landscape elements, particularly hillslope and fluvial processes, is an important aspect of Plio-Pleistocene landscape evolution and its sedimentary record in many high mountain environments. Environments that have been relatively recently glaciated but are no longer may still show elevated landscape change rates compared to those that have never been glaciated. Nonglacial geomorphic processes which nevertheless have been conditioned by past glaciation are termed paraglacial processes | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology This concept contrasts with periglacial processes, which are directly driven by formation or melting of ice or frost. Soil, regolith, and rock move downslope under the force of gravity via creep, slides, flows, topples, and falls. Such mass wasting occurs on both terrestrial and submarine slopes, and has been observed on Earth, Mars, Venus, Titan and Iapetus. Ongoing hillslope processes can change the topology of the hillslope surface, which in turn can change the rates of those processes. Hillslopes that steepen up to certain critical thresholds are capable of shedding extremely large volumes of material very quickly, making hillslope processes an extremely important element of landscapes in tectonically active areas. On the Earth, biological processes such as burrowing or tree throw may play important roles in setting the rates of some hillslope processes. Both volcanic (eruptive) and plutonic (intrusive) igneous processes can have important impacts on geomorphology. The action of volcanoes tends to rejuvenize landscapes, covering the old land surface with lava and tephra, releasing pyroclastic material and forcing rivers through new paths. The cones built by eruptions also build substantial new topography, which can be acted upon by other surface processes. Plutonic rocks intruding then solidifying at depth can cause both uplift or subsidence of the surface, depending on whether the new material is denser or less dense than the rock it displaces | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Tectonic effects on geomorphology can range from scales of millions of years to minutes or less. The effects of tectonics on landscape are heavily dependent on the nature of the underlying bedrock fabric that more or less controls what kind of local morphology tectonics can shape. Earthquakes can, in terms of minutes, submerge large areas of land creating new wetlands. Isostatic rebound can account for significant changes over hundreds to thousands of years, and allows erosion of a mountain belt to promote further erosion as mass is removed from the chain and the belt uplifts. Long-term plate tectonic dynamics give rise to orogenic belts, large mountain chains with typical lifetimes of many tens of millions of years, which form focal points for high rates of fluvial and hillslope processes and thus long-term sediment production. Features of deeper mantle dynamics such as plumes and delamination of the lower lithosphere have also been hypothesised to play important roles in the long term (> million year), large scale (thousands of km) evolution of the Earth's topography (see dynamic topography). Both can promote surface uplift through isostasy as hotter, less dense, mantle rocks displace cooler, denser, mantle rocks at depth in the Earth. Marine processes are those associated with the action of waves, marine currents and seepage of fluids through the seafloor. Mass wasting and submarine landsliding are also important processes for some aspects of marine geomorphology | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Because ocean basins are the ultimate sinks for a large fraction of terrestrial sediments, depositional processes and their related forms (e.g., sediment fans, deltas) are particularly important as elements of marine geomorphology. Different geomorphological processes dominate at different spatial and temporal scales. Moreover, scales on which processes occur may determine the reactivity or otherwise of landscapes to changes in driving forces such as climate or tectonics. These ideas are key to the study of geomorphology today. To help categorize landscape scales some geomorphologists might use the following taxonomy: There is a considerable overlap between geomorphology and other fields. Deposition of material is extremely important in sedimentology. Weathering is the chemical and physical disruption of earth materials in place on exposure to atmospheric or near surface agents, and is typically studied by soil scientists and environmental chemists, but is an essential component of geomorphology because it is what provides the material that can be moved in the first place. Civil and environmental engineers are concerned with erosion and sediment transport, especially related to canals, slope stability (and natural hazards), water quality, coastal environmental management, transport of contaminants, and stream restoration | https://en.wikipedia.org/wiki?curid=78534 |
Geomorphology Glaciers can cause extensive erosion and deposition in a short period of time, making them extremely important entities in the high latitudes and meaning that they set the conditions in the headwaters of mountain-born streams; glaciology therefore is important in geomorphology. | https://en.wikipedia.org/wiki?curid=78534 |
Pan (crater) Pan is the largest crater on Jupiter's moon Amalthea. It is kilometers across and at least 8 kilometers deep, with its center's coordinates being 30°N, 30°W. It is named after Pan, the Greek god of shepherds and the countryside, or the son of Amalthea and Hermes in some legends. | https://en.wikipedia.org/wiki?curid=78880 |
Reduced gas A reduced gas is a gas with a low oxidation number (or high reduction), and is usually hydrogen-rich. Strongly reduced gases include methane, ammonia, and hydrogen sulfide. | https://en.wikipedia.org/wiki?curid=81723 |
Chemical synthesis is the artificial execution of useful chemical reactions to obtain one or several products. This occurs by physical and chemical manipulations usually involving one or more reactions. In modern laboratory uses, the process is reproducible, reliable, and established to work the same in multiple laboratories. A chemical synthesis involves one or more compounds known as reagents or reactants which will undergo a transformation when subjected to certain conditions. Various reaction types can be applied to formulate a desired product. This requires mixing the compounds in a reaction vessel, such as a chemical reactor or a simple round-bottom flask. Many reactions require some form of work-up or purification procedure to isolate the final product. The amount of product produced in a chemical synthesis is the reaction yield, which is typically expressed as a percentage conversion of the limiting reactant. Typically, chemical yields are expressed as a weight in grams (in a laboratory setting) or as a percentage of the total theoretical quantity of product that could be produced based on the limiting reagent. A side reaction is an unwanted chemical reaction taking place, reducing the yield of the desired product. The word "synthesis" was first used by the chemist Hermann Kolbe. Many strategies exist in chemical synthesis that go beyond converting reactant A to reaction product B in a single step | https://en.wikipedia.org/wiki?curid=85029 |
Chemical synthesis In multistep synthesis, a chemical compound is synthesised though a series of individual chemical reactions, each with their own work-up. For example, a laboratory synthesis of paracetamol can consist of three individual synthetic steps. In cascade reactions multiple chemical transformations take place within a single reactant, in multi-component reactions up to 11 different reactants form a single reaction product and in a telescopic synthesis one reactant goes through multiple transformations without isolation of intermediates. Organic synthesis is a special branch of chemical synthesis dealing with the synthesis of organic compounds. In the total synthesis of a complex product it may take multiple steps to synthesize the product of interest, and inordinate amounts of time. Skill in organic synthesis is prized among chemists and the synthesis of exceptionally valuable or difficult compounds has won chemists such as Robert Burns Woodward the Nobel Prize for Chemistry. If a chemical synthesis starts from basic laboratory compounds, it is considered a purely synthetic process. If it starts from a product isolated from plants or animals and then proceeds to new compounds, the synthesis is described as a semisynthetic process. Inorganic synthesis and organometallic synthesis are applied to the preparation of compounds with significant non-organic content. An illustrative example is the preparation of the anticancer drug cisplatin from potassium tetrachloroplatinate. | https://en.wikipedia.org/wiki?curid=85029 |
Mannan may refer to a plant polysaccharide that is a linear polymer of the sugar mannose. Plant mannans have β(1-4) linkages. It is a form of storage polysaccharide. Ivory nut is a source of mannan. may also refer to a cell wall polysaccharide found in yeasts. This type of mannan has a α(1-6) linked backbone and α(1-2) and α(1-3) linked branches. It is serologically similar to structures found on mammalian glycoproteins. Detection of mannan leads to lysis in the mannan-binding lectin pathway. This mannan is the source of MOS used as prebiotics in animal husbandry and nutritional supplements. From 'manna', produced by several species of tree and shrub e.g. "Fraxinus ornus" from whose secretions mannitol was originally isolated. | https://en.wikipedia.org/wiki?curid=86604 |
Khālid ibn ʿAbd al‐Malik al‐Marwarrūdhī () was a Zanji slave who was taken to Persia in the 9th century. Together with ʿAlī ibn ʿĪsā al-Asṭurlābī in 827, he measured at 35 degrees north latitude, in the valley of the Tigris, the length of a meridian arc and thus the Earth's circumference, getting a result of 40,248 km (or, according to other sources, 41,436 km). The two researchers measured in Arabian ell, and determined the geographical latitudes of the end points they used from the star altitudes in a celestial horizontal coordinate system. We believe that 1 Arabian ell was 49 1/3 cm. Thus, they found the length of 1° of meridian to be 111.8 km (115.1 km), which differs from the actual value by 850 metres. | https://en.wikipedia.org/wiki?curid=86820 |
Gene knockout A gene knockout (abbreviation: KO) is a genetic technique in which one of an organism's genes is made inoperative ("knocked out" of the organism). However, KO can also refer to the gene that is knocked out or the organism that carries the gene knockout. Knockout organisms or simply knockouts are used to study gene function, usually by investigating the effect of gene loss. Researchers draw inferences from the difference between the knockout organism and normal individuals. The KO technique is essentially the opposite of a gene knock-in. Knocking out two genes simultaneously in an organism is known as a double knockout (DKO). Similarly the terms triple knockout (TKO) and quadruple knockouts (QKO) are used to describe three or four knocked out genes, respectively. However, one needs to distinguish between heterozygous and homozygous KOs. In the former, only one of two gene copies (alleles) is knocked out, in the latter both are knocked out. Knockouts are accomplished through a variety of techniques. Originally, naturally occurring mutations were identified and then gene loss or inactivation had to be established by DNA sequencing or other methods. Traditionally, homologous recombination was the main method for causing a gene knockout. This method involves creating a DNA construct containing the desired mutation. For knockout purposes, this typically involves a drug resistance marker in place of the desired knockout gene. The construct will also contain a minimum of 2kb of homology to the target sequence | https://en.wikipedia.org/wiki?curid=89242 |
Gene knockout The construct can be delivered to stem cells either through microinjection or electroporation. This method then relies on the cell's own repair mechanisms to recombine the DNA construct into the existing DNA. This results in the sequence of the gene being altered, and most cases the gene will be translated into a nonfunctional protein, if it is translated at all. However, this is an inefficient process, as homologous recombination accounts for only 10 to 10 of DNA integrations. Often, the drug selection marker on the construct is used to select for cells in which the recombination event has occurred.These stem cells now lacking the gene could be used in vivo, for instance in mice, by inserting them into early embryos. If the resulting chimeric mouse contained the genetic change in their germline, this could then be passed on offspring. In diploid organisms, which contain two alleles for most genes, and may as well contain several related genes that collaborate in the same role, additional rounds of transformation and selection are performed until every targeted gene is knocked out. Selective breeding may be required to produce homozygous knockout animals. There are currently three methods in use that involve precisely targeting a DNA sequence in order to introduce a double-stranded break. Once this occurs, the cell's repair mechanisms will attempt to repair this double stranded break, often through non-homologous end joining (NHEJ), which involves directly ligating the two cut ends together | https://en.wikipedia.org/wiki?curid=89242 |
Gene knockout This may be done imperfectly, therefore sometimes causing insertions or deletions of base pairs, which cause frameshift mutations. These mutations can render the gene in which they occur nonfunctional, thus creating a knockout of that gene. This process is more efficient than homologous recombination, and therefore can be more easily used to create biallelic knockouts. Zinc-finger nucleases consist of DNA binding domains that can precisely target a DNA sequence. Each zinc finger can recognize codons of a desired DNA sequence, and therefore can be modularly assembled to bind to a particular sequence. These binding domains are coupled with a restriction endonuclease that can cause a double stranded break (DSB) in the DNA. Repair processes may introduce mutations that destroy functionality of the gene. Transcription activator-like effector nucleases (TALENs) also contain a DNA binding domain and a nuclease that can cleave DNA. The DNA binding region consists of amino acid repeats that each recognize a single base pair of the desired targeted DNA sequence. If this cleavage is targeted to a gene coding region, and NHEJ-mediated repair introduces insertions and deletions, a frameshift mutation often results, thus disrupting function of the gene. Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 is a method for genome editing that contains a guide RNA complexed with a Cas9 protein | https://en.wikipedia.org/wiki?curid=89242 |
Gene knockout The guide RNA can be engineered to match a desired DNA sequence through simple complementary base pairing, as opposed to the time-consuming assembly of constructs required by zinc-fingers or TALENs. The coupled Cas9 will cause a double stranded break in the DNA. Following the same principle as zinc-fingers and TALENs, the attempts to repair these double stranded breaks often result in frameshift mutations that result in an nonfunctional gene. Gene knockin is similar to gene knockout, but it replaces a gene with another instead of deleting it. A conditional knockout allows gene deletion in a tissue in a time specific manner. This is required in place of a gene knockout if the null mutation would lead to embryonic death. This is done by introducing short sequences called loxP sites around the gene. These sequences will be introduced into the germ-line via the same mechanism as a knock-out. This germ-line can then be crossed to another germline containing Cre-recombinase which is a viral enzyme that can recognize these sequences, recombines them and deletes the gene flanked by these sites. Knockouts are primarily used to understand the role of a specific gene or DNA region by comparing the knockout organism to a wildtype with a similar genetic background | https://en.wikipedia.org/wiki?curid=89242 |
Gene knockout Knockout organisms are also used as screening tools in the development of drugs, to target specific biological processes or deficiencies by using a specific knockout, or to understand the mechanism of action of a drug by using a library of knockout organisms spanning the entire genome, such as in "Saccharomyces cerevisiae". | https://en.wikipedia.org/wiki?curid=89242 |
Nils Gabriel Sefström (2 June 1787 – 30 November 1845) was a Swedish chemist. Sefström was a student of Berzelius and, when studying the brittleness of steel in 1830, he rediscovered a new chemical element, to which he gave the name vanadium. Vanadium was first discovered by the Spanish-Mexican mineralogist Andrés Manuel del Río in 1801. He named it erythronium. Friedrich Wöhler later confirmed that vanadium and erythronium were the same substance. Sefström was member of the Royal Swedish Academy of Sciences from 1815. The Spitzbergen glacier Sefströmbreen, and the mountain ridge of Sefströmkammen, are named after him. | https://en.wikipedia.org/wiki?curid=92311 |
Monsanto The Company () was an American agrochemical and agricultural biotechnology corporation founded in 1901. In 2018, it was acquired by Bayer as part of its crop science division. It was headquartered in Creve Coeur, Missouri. developed Roundup, a glyphosate-based herbicide, in the 1970s, and became a major producer of genetically engineered crops. was one of four groups to introduce genes into plants in 1983, and was among the first to conduct field trials of genetically modified crops in 1987. It was one of the top 10 US chemical companies until it divested most of its chemical businesses between 1997 and 2002, through a process of mergers and spin-offs that focused the company on biotechnology. was one of the first companies to apply the biotechnology industry business model to agriculture, using techniques developed by biotech drug companies. In this business model, companies recoup R&D expenses by exploiting biological patents. Monsanto's roles in agricultural changes, biotechnology products, lobbying of government agencies, and roots as a chemical company, resulted in controversies. The company once manufactured controversial products such as the insecticide DDT, PCBs, Agent Orange, and recombinant bovine growth hormone. Its seed patenting model was criticized as biopiracy and a threat to biodiversity as invasive species. In September 2016, Bayer announced its intent to acquire for US$66 billion in an all-cash deal | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto After gaining US and EU regulatory approval, the sale was completed on June 7, 2018 where the name was no longer used, but Monsanto's previous product brand names were maintained. The company ranked 199th on the 2018 Fortune 500 of the largest United States corporations by revenue. In 1901 was founded in St. Louis, Missouri, as a chemical company. The founder was John Francis Queeny, a 30‑year veteran of the nascent pharmaceutical industry. He funded the firm with his own money and capital from a soft drink distributor. He used his wife, Olga Méndez Monsanto's, maiden name for the company. The company's first products were commodity food additives, such as the artificial sweetener saccharin, caffeine and vanillin. expanded to Europe in 1919 in a partnership with Graesser's Chemical Works at Cefn Mawr, Wales. The venture produced vanillin, aspirin and its raw ingredient salicylic acid, and later rubber processing chemicals. In the 1920s, expanded into basic industrial chemicals such as sulfuric acid and PCBs. Queeny's son Edgar Queeny took over the company in 1928. In 1926 the company founded and incorporated a town called in Illinois (now known as Sauget). It was formed to provide minimal regulation and low taxes for plants at a time when local jurisdictions had most of the responsibility for environmental rules. It was renamed in honor of Leo Sauget, its first village president. In 1935, bought the Swann Chemical Company in Anniston, Alabama, and thereby entered the business of producing PCBs | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In 1936, acquired Thomas & Hochwalt Laboratories in Dayton, Ohio, to acquire the expertise of Charles Allen Thomas and Carroll A. Hochwalt. The acquisition became Monsanto's Central Research Department. Thomas spent the rest of his career at Monsanto, serving as President (1951–1960) and Board Chair (1960–1965). He retired in 1970. In 1943, Thomas was called to a meeting in Washington, D.C., with Leslie Groves, commander of the Manhattan Project, and James Conant, president of Harvard University and chairman of the National Defense Research Committee (NDRC). They urged Thomas to become co-director of the Manhattan Project at Los Alamos with Robert Oppenheimer, but Thomas was reluctant to leave Dayton and Monsanto. He joined the NDRC, and Monsanto's Central Research Department began to conduct related research. To that end, operated the Dayton Project, and later Mound Laboratories, and assisted in the development of the first nuclear weapons. In 1946, developed and marketed "All" laundry detergent, which they sold to Lever Brothers in 1957. In 1947, its styrene factory was destroyed in the Texas City Disaster. In 1949, acquired American Viscose Corporation from Courtaulds. In 1954, partnered with German chemical giant Bayer to form Mobay and market polyurethanes in the United States. began manufacturing DDT in 1944, along with some 15 other companies. This insecticide was critical to the fight against malaria-transmitting mosquitoes. Due to DDT's toxicity, it was banned in the United States in 1972 | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In 1977, stopped producing PCBs; Congress banned PCB production two years later. In the mid‑1960s, William Standish Knowles and his team invented a way to selectively synthesize enantiomers via asymmetric hydrogenation. This was the first method for the catalytic production of pure chiral compounds. Knowles' team designed the "first industrial process to chirally synthesize an important compound"—L‑dopa, which is used to treat Parkinson's disease. In 2001, Knowles and Ryōji Noyori won the Nobel Prize in Chemistry. In the mid-1960s, chemists at developed the process for making acetic acid, which until 2000 was the most widely used production method. In 1964, chemists invented AstroTurf (initially ChemGrass). In the 1960s and 1970s, was a producer of Agent Orange for United States Armed Forces operations in Vietnam, and settled out of court in a lawsuit brought by veterans in 1984. In 1968, it became the first company to start mass production of (visible) light-emitting diodes (LEDs), using gallium arsenide phosphide. From 1968 to 1970, sales doubled every few months. Their products (discrete LEDs and seven-segment numeric displays) became industry standards. The primary markets then were electronic calculators, digital watches and digital clocks. became a pioneer of optoelectronics in the 1970s. Between 1968 and 1974, the company sponsored the PGA Tour event in Pensacola, Florida, which was renamed the Open | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In 1974, Harvard University and signed a 10-year research grant to support the cancer research of Judah Folkman, which became the largest such arrangement ever made; medical inventions arising from that research were the first for which Harvard allowed its faculty to submit patent application. scientists were among the first to genetically modify a plant cell, publishing their results in 1983. Five years later the company conducted the first field tests of genetically modified crops. Increasing involvement in agricultural biotechnology dates from the installment of Richard Mahoney as Monsanto's CEO in 1983. This involvement increased under the leadership of Robert Shapiro, appointed CEO in 1995, leading ultimately to the disposition of product lines unrelated to agriculture. In 1985, acquired G. D. Searle & Company, a life sciences company that focused on pharmaceuticals, agriculture and animal health. In 1993, its Searle division filed a patent application for Celebrex, which in 1998 became the first selective COX‑2 inhibitor to be approved by the U.S. Food and Drug Administration (FDA). Celebrex became a blockbuster drug and was often mentioned as a key reason for Pfizer's acquisition of Monsanto's pharmaceutical business in 2002. In 1994, introduced a recombinant version of bovine somatotropin, brand-named Posilac. later sold this business to Eli Lilly and Company | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In 1996, purchased Agracetus, the biotechnology company that had generated the first transgenic cotton, soybeans, peanuts and other crops, and from which had been licensing technology since 1991. first entered the maize seed business when it purchased 40% of Dekalb in 1996; it purchased the remainder of the corporation in 1998. In 1997, the company first published an annual report citing Monsanto's Law, a biotechnological take on Moore's Law, indicating its future directions and exponential growth in the use of biotechnology. In the same year, Californian GMO company Calgene was acquired. In 1998, purchased Cargill's international seed business, which gave it access to sales and distribution facilities in 51 countries. In 2005, it finalized the purchase of Seminis Inc, a leading global vegetable and fruit seed company, for $1.4 billion. This made it the world's largest conventional seed company. In 1999 sold off NutraSweet Co. In December of the same year, agreed to merge with Pharmacia & Upjohn, in a deal valuing the transaction at $27 billion. The agricultural division became a wholly owned subsidiary of the "new" Pharmacia; Monsanto's medical research division, which included products such as Celebrex. In 2000: Pharmacia spun off its agro-biotech subsidiary into a new company, the "new Monsanto", focused on four key agricultural crops—soybeans, maize, wheat and cotton. agreed to indemnify Pharmacia against potential liabilities from judgments against Solutia | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto As a result, the new continued to be a party to numerous lawsuits over the prior Monsanto. Pharmacia was bought by Pfizer in 2003.) In 2005 acquired Emergent Genetics and its Stoneville and NexGen cotton brands. Emergent was the third largest U.S. cotton seed company, with about 12% of the U.S. market. Monsanto's goal was to obtain "a strategic cotton germplasm and traits platform." Also in 2005, purchased Seminis, the California-based world leader in vegetable seed production, for $1.4 billion. Seminis developed new vegetable varieties using advanced cross-pollination methods. indicated that Seminis would continue with non-GM development, while not ruling out GM in the longer term. In June 2007, purchased Delta and Pine Land Company, a major cotton seed breeder, for $1.5 billion. As a condition for approval from the Department of Justice, was obligated to divest its Stoneville cotton business, which it sold to Bayer, and to divest its NexGen cotton business, which it sold to Americot. also exited the pig-breeding business by selling Choice Genetics to Newsham Genetics LC in November, divesting itself of "any and all swine-related patents, patent applications, and all other intellectual property". In 2007, and BASF announced a long-term agreement to cooperate in the research, development, and marketing of new plant biotechnology products | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In 2008, purchased Dutch seed company De Ruiter Seeds for €546 million, and sold its POSILAC bovine somatotropin brand and related business to Elanco Animal Health, a division of Eli Lilly & Co, in August for $300 million plus "additional contingent consideration". In 2012 purchased for $210 million Precision Planting Inc., a company that produced computer hardware and software designed to enable farmers to increase yield and productivity through more precise planting. In 2013 purchased San Francisco-based Climate Corp for $930 million. Climate Corp. makes local weather forecasts for farmers based on data modelling and historical data; if the forecasts were wrong, the farmer was compensated. In May 2013, A worldwide protest against corporation, called March Against was held in over 400 cities. A second protest took place in May 2014. In 2015 tried to acquire Swiss agro-biotechnology rival, Syngenta, for US$46.5 billion, but failed. In 2015 was the world's biggest supplier of seeds, controlling 26% of the global seed market (Du Pont was second with 21%). is the only manufacturer of white phosphorus for military use in the US. In September 2016, agreed to be acquired by Bayer for US$66 billion. In an effort to receive regulatory clearance for the deal, Bayer announced the sale of significant portions of its current agriculture businesses, including its seed and herbicide businesses, to BASF. The deal was approved by the European Union on March 21, 2018, and approved in the United States on May 29, 2018 | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto The sale closed on June 7, 2018; Bayer announced its intent to discontinue the name, with the combined company operating solely under the Bayer brand. Following its 1970 introduction, Monsanto's last commercially relevant United States patent on the herbicide glyphosate (brand name RoundUp) expired in 2000. Glyphosate has since been marketed by many agrochemical companies, in various solution strengths and with various adjuvants, under dozens of tradenames. As of 2009, glyphosate represented about 10% of Monsanto's revenue. Roundup-related products (which include genetically modified seeds) represented about half of Monsanto's gross margin. As of 2015, Monsanto's line of seed products included corn, cotton, soy and vegetable seeds. Many of Monsanto's agricultural seed products are genetically modified, such as for resistance to herbicides, including glyphosate and dicamba. calls glyphosate-tolerant seeds "Roundup Ready". Monsanto's introduction of this system (planting a glyphosate-resistant seed and then applying glyphosate once plants emerged) allowed farmers to increase yield by planting rows closer together. Without it, farmers had to plant rows far enough apart to allow the control of post-emergent weeds with mechanical tillage. Farmers widely adopted the technology—for example over 80% of maize (Mon 832), soybean (MON-Ø4Ø32-6), cotton, sugar beet and canola planted in the United States are glyphosate-tolerant | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto developed a Roundup Ready genetically modified wheat (MON 71800) but ended development in 2004 due to concerns from wheat exporters about the rejection of genetically modified (GM) wheat by foreign markets. Two patents were critical to Monsanto's GM soybean business; one expired in 2011 and the other in 2014. The second expiration meant that glyphosate resistant soybeans became "generic". The first harvest of generic glyphosate-tolerant soybeans came in 2015. broadly licensed the patent to other seed companies that include glyphosate resistance trait in their seed products. About 150 companies have licensed the technology, including competitors Syngenta and DuPont Pioneer. invented and sells genetically modified seeds that make a crystalline insecticidal protein from "Bacillus thuringiensis", known as Bt. In 1995 Monsanto's potato plants producing Bt toxin were approved by the Environmental Protection Agency, following approval by the FDA, making it the first pesticide-producing crop to be approved in the United States. subsequently developed Bt maize (MON 802, MON 809, MON 863, MON 810), Bt soybean and Bt cotton. produces seed that has multiple genetic modifications, also known as "stacked traits"—for instance, cotton that make one or more Bt proteins and is resistant to glyphosate. One of these, created in collaboration with Dow Chemical Company, is called SmartStax. In 2011 launched the Genuity brand for its stacked-trait products | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto As of 2012, the agricultural seed lineup included "Roundup Ready" alfalfa, canola and sugarbeet; Bt and/or "Roundup Ready" cotton; sorghum hybrids; soybeans with various oil profiles, most with the "Roundup Ready" trait; and a wide range of wheat products, many of which incorporate the nontransgenic "clearfield" imazamox-tolerant trait from BASF. In 2013 launched the first transgenic drought tolerance trait in a line of corn hybrids branded DroughtGard. The MON 87460 trait is provided by the insertion of the cspB gene from the soil microbe "Bacillus subtilis"; it was approved by the USDA in 2011 and by China in 2013. The "Xtend Crop System" includes seed genetically modified to be resistant to both glyphosate and dicamba, and a herbicide product including those two active ingredients. In December 2014, the system was approved for use in the US. In February 2016, China approved the Roundup Ready 2 Xtend system. The lack of European Union approval led many American traders to reject the use of Xtend soybeans over concerns that the new seeds would become mixed with EU-approved seeds, leading Europe to reject American soybean exports. In 2009, scientists discovered insects that had developed resistance to the Bt Cotton planted in Gujarat. communicated this to the Indian government and its customers, stating that "Resistance is natural and expected, so measures to delay resistance are important | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto Among the factors that may have contributed to pink bollworm resistance to the Cry1Ac protein in Bollgard I in Gujarat are limited refuge planting and early use of unapproved Bt cotton seed, planted prior to GEAC approval of Bollgard I cotton, which may have had lower protein expression levels." The company advised farmers to switch to its second generation of Bt cotton – Bolguard II – which had two resistance genes instead of one. However, this advice was criticized: "an internal analysis of the statement of the Ministry of Environment and Forests says it 'appears that this could be a business strategy to phase out single gene events [that is, the first-generation Bollgard I product] and promote double genes [the second generation Bollgard II] which would fetch higher price.'" Monsanto's GM cotton seed was the subject of NGO agitation because of its higher cost. Indian farmers crossed GM varieties with local varieties, using plant breeding, violating their agreements with Monsanto. In 2009, high prices of Bt Cotton were blamed for forcing farmers of Jhabua district into debt when the crops died due to lack of rain. In 2012 was the world's largest supplier of non-GE vegetable seeds by value, with sales of $800M. 95% of the research and development for vegetable seed is in conventional breeding. The company concentrates on improving flavor. According to their website they sell "4,000 distinct seed varieties representing more than 20 species" | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto Broccoli, with the brand name "Beneforté", with increased amounts of glucoraphanin was introduced in 2010 following development by its Seminis subsidiary. Until it ended production in 1977, was the source of 99% of the polychlorinated biphenyls (PCBs) used by U.S. industry. They were sold under brand names including Aroclor and Santotherm; the name Santotherm is still used for non-chlorinated products. PCBs are a persistent organic pollutant, and cause cancer in both animals and humans, among other health effects. PCBs were initially welcomed due to the electrical industry's need for durable, safer (than flammable mineral oil) cooling and insulating fluid for industrial transformers and capacitors. PCBs were also commonly used as stabilizing additives in the manufacture of flexible PVC coatings for electrical wiring and in electronic components to enhance PVC heat and fire resistance. As transformer leaks occurred and toxicity problems arose near factories, their durability and toxicity became recognized as serious problems. PCB production was banned by the U.S. Congress in 1979 and by the Stockholm Convention on Persistent Organic Pollutants in 2001. Monsanto, Dow Chemical, and eight other chemical companies made Agent Orange for the U.S. Department of Defense. It was given its name from the color of the orange-striped barrels in which it was shipped, and was by far the most widely used of the so-called "Rainbow Herbicides" | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto developed and sold recombinant bovine somatotropin (also known as rBST and rBGH), a synthetic hormone that increases milk production by 11–16% when injected into cows. In October 2008, sold this business to Eli Lilly for $300 million plus additional considerations. The use of rBST remains controversial with respect to its effects on cows and their milk. In some markets, milk from cows that are not treated with rBST is sold with labels indicating that it is rBST-free: this milk has proved popular with consumers. In reaction to this, in early 2008 a pro-rBST advocacy group called "American Farmers for the Advancement and Conservation of Technology" (AFACT), made up of dairies and originally affiliated with Monsanto, formed and began lobbying to ban such labels. AFACT stated that "absence" labels can be misleading and imply that milk from cows treated with rBST is inferior. also developed notable technologies that were not ultimately commercialized. Genetic use restriction technology, colloquially known as "terminator technology", produces plants with sterile seeds. This trait would prevent the spread of those seeds into the wild. It also would prevent farmers from planting seeds they harvest, requiring them to purchase seed for every planting, allowing the company to enforce its licensing terms via technology. Farmers have been buying hybrid seeds for generations, instead of replanting their harvest, because second-generation hybrid seeds are inferior | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto Nevertheless, most seed companies contract only with farmers who agree not to plant harvested seeds. Terminator technology has been developed by governmental labs, university researchers and companies. The technology has not been used commercially. Rumors that and other companies intended to introduce terminator technology caused protests, for example in India. In 1999, pledged not to commercialize terminator technology. The Delta & Pine Land Company of Mississippi intended to commercialize the technology, but D&PL was acquired by in 2007. developed several strains of genetically modified wheat, including glyphosate-resistant strains, in the 1990s. Field tests were done in the United States between 1998 and 2005. As of 2017, no genetically modified wheat has been released for commercial use. engaged in high-profile lawsuits, as both plaintiff and defendant. It defended lawsuits mostly over its products' health and environmental effects. used the courts to enforce its patents, particularly in agricultural biotechnology, an approach similar to that of other companies in the field, such as Dupont Pioneer and Syngenta. also became one of the most vilified large corporations in the world, over a range of issues involving its industrial and agricultural chemical products, and GM seed. In April 2018, just prior to Bayer's acquisition, Bayer indicated that improving Monsanto's reputation represented a major challenge. That June, Bayer announced it would drop the name as part of a campaign to regain consumer trust | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto Argentina approved "Roundup Ready" soy in 1996. Between 1996 and 2008 soy production grew from 14 million acres to 42 million acres. The growth was driven by Argentine investors' interest in export markets. The consolidation led to a decrease in production of many staples such as milk, rice, maize, potatoes and lentils. As of 2004 about 150,000 small farmers had left the countryside; including 50% as of 2009 in the Chaco region. "The Guardian" reported that a representative had said, "any problems with GM soya were to do with use of the crop as a monoculture, not because it was GM. If you grow any crop to the exclusion of any other you are bound to get problems." In 2005 and 2006, attempted to enforce its patents on soymeal imported into Spain from Argentina by having Spanish customs officials seize the soymeal shipments. This has been an attempt made by to put pressure on the Argentinian government for allowing them to enforce their seed patents in Argentina as well. In 2013 environmentalist groups objected to a corn seed conditioning facility in Malvinas Argentinas, Córdoba. Neighbours objected to the risk of environmental impact. Court rulings supported the project, but environmentalist groups organised demonstrations and opened an online petition for the subject to be decided in a popular referendum. The court rulings stipulated that while construction could continue, the facility could not begin operating until the environmental impact report required by law had been duly presented | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In 2016 reached an agreement with Argentina's government on soybean seed royalty payments. agreed to give the Argentine Seed Institute (Inase) oversight over crops grown from Monsanto's Intacta genetically modified soybean seeds. Before the agreement, Argentine farmers generally avoided royalties by using seeds from previous harvests or purchased from non-registered suppliers. Inase agreed to delegate testing to grain exchanges. About 6 million sample tests were to be conducted annually. Seeds that appear to be GMOs may be tested again using a polymerase chain reaction test. Brazil is the second largest producer of GMO soy. In 2003 GM soy was found in fields planted in the state of Rio Grande do Sul. This was a controversial decision, and in response, the Landless Workers' Movement protested by invading and occupying several farm plots used for research, training and seed-processing. In 2005 Brazil passed a law creating a regulatory pathway for GM crops. was criticized by Chinese economist Larry Lang for controlling the Chinese soybean market, and for trying to do the same to Chinese corn and cotton. In the late 1990s and early 2000s, public attention was drawn to suicides by indebted farmers following crop failures. For example, in the early 2000s, farmers in Andhra Pradesh (AP) were in economic crisis due to high-interest rates and crop failures, leading to widespread unrest and farmer suicides. was one focus of protests with respect to the price and yields of Bt seed | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In 2005, the Genetic Engineering Approval Committee, the Indian regulatory authority, released a study on field tests of certain Bt cotton strains in AP and ruled that could not market those strains in AP because of poor yields. At about the same time, the state agriculture minister barred the company from selling Bt cotton seed, because refused a request by the state government to provide pay about Rs 4.5 crore (about one million US$) to indebted farmers in some districts, and because the government blamed Monsanto's seeds for crop failures. The order was later lifted. In 2006, AP tried to convince to reduce the price of Bt seeds. Unsatisfied, the state filed several cases against and its Mumbai-based licensee, Maharashtra Hybrid Seeds. Research by International Food Policy Research Institute found no evidence supporting an increased suicide rate following the introduction of Bt cotton and that Bt cotton. The report stated that farmer suicides predated commercial introduction in 2002 (and unofficial introduction in 2001) and that such suicides had made up a fairly constant portion of the overall national suicide rate since 1997. The report concluded that while Bt cotton may have been a factor in specific suicides, the contribution was likely marginal compared to socio-economic factors. As of 2009, Bt cotton was planted in 87% of Indian cotton-growing land | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto Critics including Vandana Shiva said that the crop failures could "often be traced to" Monsanto's Bt cotton, that the seeds increased farmer indebtedness and argued that misrepresented the profitability of their Bt Cotton, causing losses leading to debt. In 2009, Shiva wrote that Indian farmers who had previously spent as little as ₹7 (rupees) per kilogram were now paying up to ₹17,000 per kilo per year for Bt cotton. In 2012 the Indian Council of Agricultural Research (ICAR) and the Central Cotton Research Institute (CCRI) stated that for the first time farmer suicides could be linked to a decline in the performance of Bt cotton, and advised, "cotton farmers are in a deep crisis since shifting to Bt cotton. The spate of farmer suicides in 2011–12 has been particularly severe among Bt cotton farmers." In 2004, in response to an order from the Bombay High Court the Tata Institute produced a report on farmer suicides in Maharashtra in 2005. The survey cited "government apathy, the absence of a safety net for farmers, and lack of access to information related to agriculture as the chief causes for the desperate condition of farmers in the state." Various studies identified the important factors as insufficient or risky credit systems, the difficulty of farming semi-arid regions, poor agricultural income, absence of alternative income opportunities, a downturn in the urban economy which forced non-farmers into farming and the absence of suitable counseling services | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto ICAR and CCRI stated that the cost of cotton cultivation had jumped as a consequence of rising pesticide costs, while total Bt cotton production in the five years from 2007 to 2012 had declined. Brofiscin Quarry was used as a waste site from about 1965 to 1972 and accepted waste from BP, Veolia and Monsanto. A 2005 report by Environmental Agency Wales (EAW) found that the quarry contained up to 75 toxic substances, including heavy metals, Agent Orange and PCBs. In February 2011, agreed to help with the costs of remediation, but did not accept responsibility for the pollution. In 2011, EAW and the Rhondda Cynon Taf council announced that they had decided to place an engineered cap over the waste mass, and stated that the cost would be £1.5 million; previous estimates had been as high as £100 million. In the late 1960s, the plant in Sauget, Illinois, was the nation's largest producer of PCBs, which remained in the water along Dead Creek there. An EPA official referred to Sauget as "one of the most polluted communities in the region" and "a soup of different chemicals". In Anniston, Alabama, plaintiffs in a 2002 lawsuit provided documentation showing that the local factory knowingly discharged both mercury and PCB-laden waste into local creeks for over 40 years. In 1969 dumped 45 tons of PCBs into Snow Creek, a feeder for Choccolocco Creek, which supplies much of the area's drinking water, and buried millions of pounds of PCB in open-pit landfills located on hillsides above the plant and surrounding neighborhoods | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In August 2003, Solutia and agreed to pay plaintiffs $700 million to settle claims by over 20,000 Anniston residents. As of November 2013, was associated with nine "active" Superfund sites and 32 "archived" sites in the US, in the EPA's Superfund database. was sued and settled multiple times for damaging the health of its employees or residents near its Superfund sites through pollution and poisoning. In 2013 a Monsanto-developed transgenic cultivar of glyphosate-resistant wheat was discovered on a farm in Oregon, growing as a weed or "volunteer plant". The final Oregon field test had occurred in 2001. As of May 2013, the GMO seed source was unknown. Volunteer wheat from a former test field two miles away was tested and was not found to be glyphosate-tolerant. faced penalties up to $1 million over potential violations of the Plant Protection Act. The discovery threatened world-leading US wheat exports, which totaled $8.1 billion in 2012. This wheat variety was rarely exported to Europe and was more likely destined for Asia. said it had destroyed all the material it held after completing trials in 2004 and it was "mystified" by its appearance. On June 14, 2013, the USDA announced: "As of today, USDA has neither found nor been informed of anything that would indicate that this incident amounts to more than a single isolated incident in a single field on a single farm. All information collected so far shows no indication of the presence of GE wheat in commerce | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto " As of August 30, 2013, while the source of the GM wheat remained unknown, Japan, South Korea and Taiwan had all resumed placing orders. has faced controversy in the United States over claims that its herbicide products might be carcinogens. There is limited evidence that human cancer risk might increase as a result of occupational exposure to large amounts of glyphosate, as in agricultural work, but no good evidence of such a risk from home use, such as in domestic gardening. The consensus among national pesticide regulatory agencies and scientific organizations is that labeled uses of glyphosate have demonstrated no evidence of human carcinogenicity. Organizations such as the World Health Organization (WHO), the Food and Agriculture Organization, European Commission, Canadian Pest Management Regulatory Agency, and the German Federal Institute for Risk Assessment have concluded that there is no evidence that glyphosate poses a carcinogenic or genotoxic risk to humans. However one international scientific organization, the International Agency for Research on Cancer (IARC), affiliated with the WHO, has made claims of carcinogenicity in research reviews; in 2015 the IARC declared glyphosate "probably carcinogenic." As of October 30, 2019, there were 42,700 plaintiffs who said that glyphosate herbicides caused their cancer after the IARC report in 2015 linking glyphosate to cancer in humans. denies that Roundup is carcinogenic | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In March 2017, 40 plaintiffs filed a lawsuit at the Alameda County Superior Court, a branch of the California Superior Court, asking for damages caused by the company's glyphosate-based weed-killers, including Roundup, and demanding a jury trial. On August 10, 2018, lost the first decided case. Dewayne Johnson, who has non-Hodgkin's lymphoma, was initially awarded $289 million in damages after a jury in San Francisco said that had failed to adequately warn consumers of cancer risks posed by the herbicide. Pending appeal, the award was later reduced to $78.5 million. In November 2018, appealed the judgement, asking an appellate court to consider a motion for a new trial. On March 27, 2019, was found liable in a federal court for Edwin Hardeman's non-Hodgkin's lymphoma and ordered to pay $80 million in damages. A spokesperson for Bayer, now the parent company of Monsanto, said the company would appeal the verdict. On May 13, 2019, a jury in California ordered Bayer to pay $2 billion in damages after finding that the company had failed to adequately inform consumers of the possible carcinogenicity of Roundup. On July 26, 2019, an Alameda County judge cut the settlement to $86.7 million, stating that the judgement by the jury exceeded legal precedent | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto Following a lawsuit by a peach farmer alleging that Dicamba used as a weed killer drifted in the wind from adjacent crops to destroy his peach orchards, a Missouri trial jury found in February 2020 that and codefendant BASF were negligent in design of Dicamba and failed to warn farmers about the product, awarding $15 million for losses and $250 million in punitive damages. From 2009 to 2011, improperly accounted for incentive rebates. The actions inflated Monsanto's reported profit by $31 million over the two years. paid $80 million in penalties pursuant to a subsequent settlement with the US Securities and Exchange Commission. materially misstated its consolidated earnings in response to losing market share of Roundup to generic producers. overhauled its internal controls. Two of their top CPAs were suspended and was required to hire, at their expense, an independent ethics/compliance consultant for two years. A review of glyphosate's carcinogenic potential by four independent expert panels, with a comparison to the IARC assessment, was published in September 2016. Using emails released in August 2017 by plaintiffs' lawyers who are suing Monsanto, "Bloomberg Business Week" reported that "scientists were heavily involved in organizing, reviewing, and editing drafts submitted by the outside experts." A spokesperson responded that had provided only non-substantive cosmetic copyediting. In 2017 it was reported that an article published (in 2015) on the Forbes website by Henry I | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto Miller, under his own name, had been drafted by Monsanto. As reported by the New York Times, asked Miller to write an article rebutting the findings of the International Agency for Research on Cancer where he had indicated willingness “if I could start from a high-quality draft.” Forbes later removed his blog from Forbes.com and ended their relationship with him. regularly lobbied the US government with expenses reaching $8.8 million in 2008 and $6.3 million in 2011. $2 million was spent on matters concerning "Foreign Agriculture Biotechnology Laws, Regulations, and Trade". Some US diplomats in Europe at other times worked directly for Monsanto. made political contributions of $186,250 to federal candidates in the 2008 election cycle through its political action committee (PAC) (42% to Democrats, 58% to Republicans) and $305,749 in the 2010 election cycle (48% Democrat, 52% Republicans). California's 2012 Proposition 37 would have mandated the disclosure of genetically modified crops used in the production of California food products. spent $8.1 million opposing passage, making it the largest contributor against the initiative. The proposition was rejected by a 53.7% majority. Labeling is not required in the US. In 2009 Michael R. Taylor, food safety expert and former VP for Public Policy became a senior advisor to the FDA Commissioner. is a member of the Washington D | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto C based Biotechnology Industry Organization (BIO), the world's largest biotechnology trade association, which provides "advocacy, business development, and communications services." Between 2010 and 2011 BIO spent a total of $16.43 million on lobbying. The Company Citizenship Fund aka Citizenship Fund is a political action committee that donated over $10 million to various candidates from 2003 to 2013. As of October 2013, and DuPont Co. continued backing an anti-labeling campaign, spending roughly $18 million. The state of Washington, along with 26 other states, made proposals in November to require GMO labeling. In the US regulatory environment, many individuals move back and forth between positions in the public and private sectors, including at Monsanto. Critics argued that the connections between the company and the government allowed to obtain favorable regulations at the expense of consumer safety. Supporters of the practice point to the benefits of competent and experienced individuals in both sectors and to the importance of appropriately managing potential conflicts of interest. The list of such people includes: During the late 1990s, lobbied to raise permitted glyphosate levels in soybeans and was successful in convincing Codex Alimentarius and both the UK and US governments to lift levels 200 times to 20 milligrams per kilogram of soya | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto When asked how negotiations with were conducted, Lord Donoughue, then the Labour Party Agriculture minister in the House of Lords, stated that all information relating to the matter would be "kept secret". During the 24 months prior to the 1997 British election representatives had 22 meetings at the departments of Agriculture and the Environment. Stanley Greenberg, an election advisor to Tony Blair, later worked as a consultant. Former Labour spokesperson David Hill, became Monsanto's media adviser at the lobbying firm Bell Pottinger. The Labour government was challenged in Parliament about "trips, facilities, gifts and other offerings of financial value provided by to civil servants", but only acknowledged that Department of Trade and Industry had two working lunches with Monsanto. Peter Luff, then a Conservative Party MP and Chairman of the Agriculture Select Committee, received up to £10,000 a year from Bell Pottinger on behalf of Monsanto. In January 2011, WikiLeaks documents suggested that US diplomats in Europe responded to a request for help from the Spanish government. One report stated, "In addition, the cables show US diplomats working directly for GM companies such as Monsanto. 'In response to recent urgent requests by [Spanish rural affairs ministry] state secretary Josep Puxeu and Monsanto, post requests renewed US government support of Spain's science-based agricultural biotechnology position through high-level US government intervention | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto '" The leaked documents showed that in 2009, when the Spanish government's policy approving MON810 was under pressure from EU interests, Monsanto's Director for Biotechnology for Spain and Portugal requested that the US government support Spain on the matter. The leaks indicated that Spain and the US had worked closely together to "persuade the EU not to strengthen biotechnology laws". Spain was viewed as a key GMO supporter and a leading indicator of support across the continent. The leaks also revealed that in response to an attempt by France to ban MON810 in late 2007, then-US ambassador to France, Craig Roberts Stapleton, asked Washington to "calibrate a targeted retaliation list that [would cause] some pain across the EU", targeting countries that did not support the use of GM crops. This activity transpired after the US, Australia, Argentina, Brazil, Canada, India, Mexico and New Zealand had brought an action against Europe via the World Trade Organization with respect to the EU's banning of GMOs; in 2006, the WTO had ruled against the EU. was a member of EuropaBio, the leading biotechnology trade group in Europe. One of EuropaBio's initiatives is "Transforming Europe's position on GM food". It found "an urgent need to reshape the terms of the debate about GM in Europe". EuropaBio proposed the recruitment of high-profile "ambassadors" to lobby EU officials | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto In September 2017 lobbyists were banned from the European parliament after the refused to attend a parliamentary hearing into allegations of regulatory interference. After the 2010 Haiti earthquake, donated $255,000 for disaster relief and 60,000 seed sacks (475 tons) of hybrid (non-GM) corn and vegetable seeds worth $4 million. However, a Catholic Relief Services (CRS) rapid assessment of seed supply and demand for the five most common food security crops found that the Haitians had enough seed and recommended that imported seeds be introduced only on a small scale. Emmanuel Prophete, head of Haiti's Ministry of Agriculture's Service National Semencier (SNS), stated that SNS was not opposed to the hybrid maize seeds because they at least double yields. Louise Sperling, Principal Researcher at the International Center for Tropical Agriculture (CIAT) told HGW that she was not opposed to hybrids, but noted that most hybrids required extra water and better soils and that most of Haiti was not appropriate for hybrids. Activists objected that some of the seeds were coated with the fungicides Maxim or thiram. In the United States, pesticides containing thiram are banned in home garden products because most home gardeners do not have adequate protection. Activists wrote that the coated seeds were handled in a dangerous manner by the recipients. The donated seeds were sold at a reduced price in local markets | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto However, farmers feared that they were being given seeds that would "threaten local varieties" and an estimated 8,000–12,000 farmers attended a protest of the donation on June 4, 2010, organized by a Haitian farmers' association, the Peasant Movement of Papay, where a small pile of seeds was symbolically burned. has engaged in various public relations campaigns to improve its image and public perception of some of its products. These include developing a relationship with scientist Richard Doll with respect to Agent Orange. Other campaigns include the joint funding with other biotech companies for the website GMO Answers. has been a major funder of science research at Washington University in St. Louis for many years. This research is highlighted by the Washington University/Biomedical Research Agreement, which has brought more than $100 million of research funding to the university. Washington University built the Laboratory of the Life Sciences in 1965. In 2015, gave Washington University's Institute for School Partnership a $1.94 million grant to help better teach students in STEM fields. In 2009 was chosen as "Forbes" magazine's company of the year. In 2010 Swiss research firm Covalence rated least ethical of 581 multinational corporations based on their EthicalQuote reputation tracking index which "aggregates thousands of positive and negative news items published by the media, companies, and stakeholders". without attempt to validate sources | https://en.wikipedia.org/wiki?curid=93825 |
Monsanto The journal "Science" ranked in its Top 20 Employers list between 2011 and 2014. In 2012, it described the company as "innovative leader in the industry", "makes changes needed" and "does important quality research". executive Robert Fraley won the World Food Prize for "breakthrough achievements in founding, developing, and applying modern agricultural biotechnology". | https://en.wikipedia.org/wiki?curid=93825 |
Agricultural biotechnology Agricultural biotechnology, also known as agritech, is an area of agricultural science involving the use of scientific tools and techniques, including genetic engineering, molecular markers, molecular diagnostics, vaccines, and tissue culture, to modify living organisms: plants, animals, and microorganisms. Crop biotechnology is one aspect of agricultural biotechnology which has been greatly developed upon in recent times. Desired trait are exported from a particular species of Crop to an entirely different species. These transgene crops possess desirable characteristics in terms of flavor, colour of flowers, growth rate, size of harvested products and resistance to diseases and pests. Farmers have manipulated plants and animals through selective breeding for tens of thousands of years in order to create desired traits. In the 20th century, a surge in technology resulted in an increase in agricultural biotechnology through the selection of traits like increased yield, pest resistance, drought resistance, and herbicide resistance. The first food product produced through biotechnology was sold in 1990, and by 2003, 7 million farmers were utilizing biotech crops. More than 85% of these farmers were located in developing countries. Traditional crossbreeding has been used for centuries to improve crop quality and quantity. Crossbreeding mates two sexually compatible species to create a new and special variety with the desired traits of the parents | https://en.wikipedia.org/wiki?curid=93829 |
Agricultural biotechnology For example, the honeycrisp apple exhibits a specific texture and flavor due to the crossbreeding of its parents. In traditional practices, pollen from one plant is placed on the female part of another, which leads to a hybrid that contains genetic information from both parent plants. Plant breeders select the plants with the traits they're looking to pass on and continue to breed those plants. Note that crossbreeding can only be utilized within the same or closely related species. Mutations can occur randomly in the DNA of any organism. In order to create variety within crops, scientists can randomly induce mutations within plants. Mutagenesis uses radioactivity to induce random mutations in the hopes of stumbling upon the desired trait. Scientists can use mutating chemicals such as ethyl methanesulfonate, or radioactivity to create random mutations within the DNA. Atomic gardens are used to mutate crops. A radioactive core is located in the center of a circular garden and raised out of the ground to radiate the surrounding crops, generating mutations within a certain radius. Mutagenesis through radiation was the process used to produce ruby red grapefruits. Polyploidy can be induced to modify the number of chromosomes in a crop in order to influence its fertility or size. Usually, organisms have two sets of chromosomes, otherwise known as a diploidy | https://en.wikipedia.org/wiki?curid=93829 |
Agricultural biotechnology However, either naturally or through the use of chemicals, that number of chromosomes can change, resulting in fertility changes or size modification within the crop. Seedless watermelons are created in this manner; a 4-set chromosome watermelon is crossed with a 2-set chromosome watermelon to create a sterile (seedless) watermelon with three sets of chromosomes. Protoplast fusion is the joining of cells or cell components to transfer traits between species. For example, the trait of male sterility is transferred from radishes to red cabbages by protoplast fusion. This male sterility helps plant breeders make hybrid crops. RNA interference (RNAIi) is the process in which a cell's RNA to protein mechanism is turned down or off in order to suppress genes. This method of genetic modification works by interfering with messenger RNA to stop the synthesis of proteins, effectively silencing a gene. Transgenics involves the insertion of one piece of DNA into another organism's DNA in order to introduce a new gene(s) into the original organism. This addition of genes into an organism's genetic material creates a new variety with desired traits. The DNA must be prepared and packaged in a test tube and then inserted into the new organism. New genetic information can be inserted with biolistics. An example of transgenics is the rainbow papaya, which is modified with a gene that gives it resistance to the papaya ringspot virus. Genome editing is the use of an enzyme system to modify the DNA directly within the cell | https://en.wikipedia.org/wiki?curid=93829 |
Agricultural biotechnology Genome editing is used to develop herbicide resistant canola to help farmers control weeds. has been used to improve the nutritional content of a variety of crops in an effort to meet the needs of an increasing population. Genetic engineering can produce crops with a higher concentration of vitamins. For example, golden rice contains three genes that allow plants to produce compounds that are converted to vitamin A in the human body. This nutritionally improved rice is designed to combat the world's leading cause of blindness—vitamin A deficiency. Similarly, the Banana 21 project has worked to improve the nutrition in bananas to combat micronutrient deficiencies in Uganda. By genetically modifying bananas to contain vitamin A and iron, Banana 21 has helped foster a solution to micronutrient deficiencies through the vessel of a staple food and major starch source in Africa. Additionally, crops can be engineered to reduce toxicity or to produce varieties with removed allergens. One highly sought after trait is insect resistance. This trait increases a crop's resistance to pests and allows for a higher yield. An example of this trait are crops that are genetically engineered to make insecticidal proteins originally discovered in ("Bacillus thuringiensis"). Bacillus thuringiensis is a baceteria that produces insect repelling proteins that are non-harmful to humans. The genes responsible for this insect resistance have been isolated and introduced into many crops | https://en.wikipedia.org/wiki?curid=93829 |
Agricultural biotechnology Bt corn and cotton are now commonplace, and cowpeas, sunflower, soybeans, tomatoes, tobacco, walnut, sugar cane, and rice are all being studied in relation to Bt. Weeds have proven to be an issue for farmers for thousands of years; they compete for soil nutrients, water, and sunlight and prove deadly to crops. Biotechnology has offered a solution in the form of herbicide tolerance. Chemical herbicides are sprayed directly on plants in order to kill weeds and therefore competition, and herbicide resistant crops have to the opportunity to flourish. Often, crops are afflicted by disease spread through insects (like aphids). Spreading disease among crop plants is incredibly difficult to control and was previously only managed by completely removing the affected crop. The field of agricultural biotechnology offers a solution through genetically engineering virus resistance. Developing GE disease-resistant crops now include cassava, maize, and sweet potato. can also provide a solution for plants in extreme temperature conditions. In order to maximize yield and prevent crop death, genes can be engineered that help to regulate cold and heat tolerance. For example, papaya trees have been genetically modified in order to be more tolerant of hot and cold conditions. Other traits include water use efficiency, nitrogen use efficiency and salt tolerance. Quality traits include increased nutritional or dietary value, improved food processing and storage, or the elimination of toxins and allergens in crop plants | https://en.wikipedia.org/wiki?curid=93829 |
Agricultural biotechnology Currently, only a small number of genetically modified crops are available for purchase and consumption in the United States. The USDA has approved soybeans, corn, canola, sugar beets, papaya, squash, alfalfa, cotton, apples, and potatoes. GMO apples (arctic apples) are non-browning apples and eliminate the need for anti-browning treatments, reduce food waste, and bring out flavor. The production of Bt cotton has skyrocketed in India, with 10 million hectares planted for the first time in 2011, resulting in a 50% insecticide application reduction. In 2014, Indian and Chinese farmers planted more than 15 million hectares of Bt cotton. regulation in the US falls under three main government agencies: The Department of Agriculture (USDA), the Environmental Protection Agency (EPA), and the Food and Drug Administration (FDA). The USDA must approve the release of any new GMOs, EPA controls the regulation of insecticide, and the FDA evaluates the safety of a particular crop sent to market. On average, it takes nearly 13 years and $130 million of research and development for a genetically modified organism to come to market. The regulation process takes up to 8 years in the United States. The safety of GMOs has become a topic of debate worldwide, but scientific articles are being conducted to test the safety of consuming GMOs in addition to the FDA's work. In one such article, it was concluded that Bt rice did not adversely affect digestion and did not induce horizontal gene transfer. | https://en.wikipedia.org/wiki?curid=93829 |
Aphotic zone The aphotic zone (aphotic from Greek prefix + "without light") is the portion of a lake or ocean where there is little or no sunlight. It is formally defined as the depths beyond which less than 1 percent of sunlight penetrates. Consequently, bioluminescence is essentially the only light found in this zone. Most food in this zone comes from dead organisms sinking to the bottom of the lake or ocean from overlying waters. The depth of the aphotic zone can be greatly affected by such things as turbidity and the season of the year. The aphotic zone underlies the photic zone, which is that portion of a lake or ocean directly affected by sunlight. Depending on how aphotic zone is defined, the aphotic zone of the ocean begins between depths of roughly to , and extends to the ocean floor. Temperatures can range from roughly to . Unusual and unique creatures dwell in this expanse of pitch black water, such as the gulper eel, the giant squid, the anglerfish, and the vampire squid. The aphotic zone is further divided into additional zones: the bathyal zone, the abyssal zone, and the hadal zone. The bathyal zone extends from to . The abyssal zone extends from to . The hadal zone spans from depths of to the ocean floor. Creatures in these areas must be able to live in complete darkness. | https://en.wikipedia.org/wiki?curid=98275 |
Solid-state physics is the study of rigid matter, or solids, through methods such as quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. studies how the large-scale properties of solid materials result from their atomic-scale properties. Thus, solid-state physics forms a theoretical basis of materials science. It also has direct applications, for example in the technology of transistors and semiconductors. Solid materials are formed from densely packed atoms, which interact intensely. These interactions produce the mechanical (e.g. hardness and elasticity), thermal, electrical, magnetic and optical properties of solids. Depending on the material involved and the conditions in which it was formed, the atoms may be arranged in a regular, geometric pattern (crystalline solids, which include metals and ordinary water ice) or irregularly (an amorphous solid such as common window glass). The bulk of solid-state physics, as a general theory, is focused on crystals. Primarily, this is because the periodicity of atoms in a crystal — its defining characteristic — facilitates mathematical modeling. Likewise, crystalline materials often have electrical, magnetic, optical, or mechanical properties that can be exploited for engineering purposes. The forces between the atoms in a crystal can take a variety of forms. For example, in a crystal of sodium chloride (common salt), the crystal is made up of ionic sodium and chlorine, and held together with ionic bonds | https://en.wikipedia.org/wiki?curid=102847 |
Solid-state physics In others, the atoms share electrons and form covalent bonds. In metals, electrons are shared amongst the whole crystal in metallic bonding. Finally, the noble gases do not undergo any of these types of bonding. In solid form, the noble gases are held together with van der Waals forces resulting from the polarisation of the electronic charge cloud on each atom. The differences between the types of solid result from the differences between their bonding. The physical properties of solids have been common subjects of scientific inquiry for centuries, but a separate field going by the name of solid-state physics did not emerge until the 1940s, in particular with the establishment of the Division of Solid State Physics (DSSP) within the American Physical Society. The DSSP catered to industrial physicists, and solid-state physics became associated with the technological applications made possible by research on solids. By the early 1960s, the DSSP was the largest division of the American Physical Society. Large communities of solid state physicists also emerged in Europe after World War II, in particular in England, Germany, and the Soviet Union. In the United States and Europe, solid state became a prominent field through its investigations into semiconductors, superconductivity, nuclear magnetic resonance, and diverse other phenomena | https://en.wikipedia.org/wiki?curid=102847 |
Solid-state physics During the early Cold War, research in solid state physics was often not restricted to solids, which led some physicists in the 1970s and 1980s to found the field of condensed matter physics, which organized around common techniques used to investigate solids, liquids, plasmas, and other complex matter. Today, solid-state physics is broadly considered to be the subfield of condensed matter physics that focuses on the properties of solids with regular crystal lattices. Many properties of materials are affected by their crystal structure. This structure can be investigated using a range of crystallographic techniques, including X-ray crystallography, neutron diffraction and electron diffraction. The sizes of the individual crystals in a crystalline solid material vary depending on the material involved and the conditions when it was formed. Most crystalline materials encountered in everyday life are polycrystalline, with the individual crystals being microscopic in scale, but macroscopic single crystals can be produced either naturally (e.g. diamonds) or artificially. Real crystals feature defects or irregularities in the ideal arrangements, and it is these defects that critically determine many of the electrical and mechanical properties of real materials. Properties of materials such as electrical conduction and heat capacity are investigated by solid state physics. An early model of electrical conduction was the Drude model, which applied kinetic theory to the electrons in a solid | https://en.wikipedia.org/wiki?curid=102847 |
Solid-state physics By assuming that the material contains immobile positive ions and an "electron gas" of classical, non-interacting electrons, the Drude model was able to explain electrical and thermal conductivity and the Hall effect in metals, although it greatly overestimated the electronic heat capacity. Arnold Sommerfeld combined the classical Drude model with quantum mechanics in the free electron model (or Drude-Sommerfeld model). Here, the electrons are modelled as a Fermi gas, a gas of particles which obey the quantum mechanical Fermi–Dirac statistics. The free electron model gave improved predictions for the heat capacity of metals, however, it was unable to explain the existence of insulators. The nearly free electron model is a modification of the free electron model which includes a weak periodic perturbation meant to model the interaction between the conduction electrons and the ions in a crystalline solid. By introducing the idea of electronic bands, the theory explains the existence of conductors, semiconductors and insulators. The nearly free electron model rewrites the Schrödinger equation for the case of a periodic potential. The solutions in this case are known as Bloch states. Since Bloch's theorem applies only to periodic potentials, and since unceasing random movements of atoms in a crystal disrupt periodicity, this use of Bloch's theorem is only an approximation, but it has proven to be a tremendously valuable approximation, without which most solid-state physics analysis would be intractable | https://en.wikipedia.org/wiki?curid=102847 |
Solid-state physics Deviations from periodicity are treated by quantum mechanical perturbation theory. Modern research topics in solid-state physics include: | https://en.wikipedia.org/wiki?curid=102847 |
Menlo Park, California Menlo Park is a city at the eastern edge of San Mateo County, in the San Francisco Bay Area of California, in the United States. It is bordered by San Francisco Bay on the north and east; East Palo Alto, Palo Alto, and Stanford to the south; Atherton, North Fair Oaks, and Redwood City to the west. Menlo Park is one of the most educated cities in the state of California and the United States; nearly 70% of residents over the age of 25 have earned a bachelor's degree or higher. Menlo Park had 32,026 inhabitants according to the 2010 United States Census, which had grown to an estimated 34,549 inhabitants by 2018. The city is home to the corporate headquarters of Facebook and where Google and Round Table Pizza were founded. According to the United States Census Bureau, the city has a total area of , of which is land and is water. The total area is 43.79% water. Menlo Park is long and narrow on a northeast to southwest axis. The northeast portion borders the San Francisco Bay and includes the Dumbarton Bridge that connects Menlo Park to Fremont on the east side of the bay. The city shoreline includes the city's largest park, Bedwell Bayfront Park and the Don Edwards San Francisco Bay National Wildlife Refuge. San Francisquito Creek marks much of the southeast border of the city. West Menlo Park (not part of the city despite its name) along Alameda de las Pulgas nearly separates the southwestern part of the city (known as Sharon Heights) from the rest. The extreme southwest is clipped by Interstate 280 | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California The Bayshore Freeway (part of U.S. Route 101) traverses Menlo Park northwest to southeast near the shoreline and somewhat parallel to it to the southwest is El Camino Real. The intersection of El Camino Real and Santa Cruz Avenue is considered the heart of the city. Nearby, the Menlo Park Civic center is bounded by Ravenswood Avenue, Alma Street, Laurel Street and Burgess Drive. It contains the council offices, library, police station and "Burgess Park" which has various recreational facilities. Other major roads include Sand Hill Road in the Sharon Heights area. The residential areas of Menlo Park can be unofficially divided into several neighborhoods. From "east" (northeast toward San Francisco Bay) to "west" (southwest toward the Pacific coast), they are defined by the "Palo Alto Weekly" as follows: Belle Haven is the only neighborhood east of Route 101; much of the rest of that area is business or protected land. Between 101 and the roughly parallel Middlefield Road are the neighborhoods of the Willows, Suburban Park, Lorelei Manor, Flood Triangle, Vintage Oaks, and South of Seminary (the seminary being Saint Patrick's Seminary). Between Middlefield and El Camino Real are the Caltrain track and Felton Gables, Linfield Oaks, and Park Forest. West of El Camino until the foothills of the Peninsula are the neighborhoods of Downtown Menlo Park, Central Menlo Park, and Allied Arts (sometimes also known as Stanford Park, it is named for the Allied Arts Guild in it) | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California In the hills are Sharon Heights and Stanford Hills. Several other neighborhoods are closely associated with Menlo Park but are actually in unincorporated San Mateo county; these include Menlo Oaks and Fair Oaks (latter part of the North Fair Oaks census area) between Bayshore and Middlefield, University Heights (also known as West Menlo Park) between Sharon Heights and most of the rest of the city, and Stanford Weekend Acres which is somewhat near Stanford Hills. The area of Menlo Park was inhabited by the Ohlone people when the Portolá expedition arrived in 1769. In 1795 the Rancho de las Pulgas land grant was made that include the area of the current city. In 1851 two Irish immigrants, Dennis J. Oliver and his brother-in-law D. C. McGlynn, purchased a tract of land on the former Rancho de las Pulgas. In 1854, they erected a gate with a wooden arch bearing the inscription "Menlo Park" and the date "August 1854" at the entrance to their property (now the intersection of Middle Ave and El Camino Real). The word "Menlo" derived from the owners' former home of Menlo in County Galway, Ireland, and is an Anglicized version of the original Irish name of the place, "Mionloch", meaning "middle lake." In 1863, the San Francisco and San Jose Rail Road had built the railroad from San Francisco to as far as Mayfield (now California Avenue station in Palo Alto) and started running trains to the area. They named a nearby station "Menlo Park" after the sign | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California The 1867 station building still stands on the platform of the current Caltrain station, used by the local Chamber of Commerce. It holds the record as the oldest, continually operating train station in all of California. The town of Menlo Park grew up around this station, becoming a popular home for San Francisco businessmen. A post office arrived in 1870, and the city was incorporated in 1874 (it would dissolve after two years but would later be permanently incorporated in 1927). The original arch which gave its name to the stations and ultimately, the city, survived until 1922, when the original arch was destroyed in an automobile accident. The origin of the name of "Menlo Park, California" ("ca" 1850) pre-dates any work done by Thomas Edison ("ca" 1876) in Menlo Park, New Jersey; Menlo Park, New Jersey was named after Menlo Park, California. In 1917/1918 a large portion of Menlo Park was the site of Camp Fremont, a training camp for, at its height, 27,000 men being sent to fight in World War I. It didn't last long (the camp was dismantled after the war), but army engineers paved the first streets in Menlo Park and laid the first water and gas lines. The army did retain the camp hospital, and it is now the site of a Veterans Administration hospital off of Willow road in Menlo Park. In the autumn of 1918 a flu pandemic hit Camp Fremont and killed 147 | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California At the start of World War II, the US government bought the estate of Timothy Hopkins from his widow and created the Palo Alto General Hospital later renamed the Dibble General Hospital (after Colonel John Dibble who was killed in 1943). After the war ended, some of the land was sold to the city and became the sites of the main library and city hall. More of the land was bought by Stanford University to house the increase in students due to the G.I. Bill; the area was known as the "Stanford Village," which existed as student housing until the mid-1960s. This land also was the site of the Stanford Research Institute (now SRI International) starting in 1947; between 1955 and 1968 SRI bought the rest of the Stanford Village. In the 1960s, the former estate of Frederick W. Sharon (1859–1914) (son of Senator William Sharon) and his wife, Louise Tevis Breckinridge Sharon (1858–1938; daughter of Lloyd Tevis and divorced wife of John Witherspoon Breckinridge), in the hills of south west Menlo Park was developed and called "Sharon Heights." The 2010 United States Census reported that Menlo Park had a population of 32,026. The population density was 3,271.3 people per square mile (1,263.1/km²). The racial makeup of Menlo Park was 22,494 (70.2%) White, 1,551 (4.8%) African American, 156 (0.5%) Native American, 3,157 (9.9%) Asian, 454 (1.4%) Pacific Islander, 2,776 (8.7%) from other races, and 1,438 (4.5%) from two or more races. There were 5,902 people (18.4%) of Hispanic or Latino background, of any race | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California Among the Hispanic population, 4,303 were of Mexican ancestry. The Census reported that 31,181 people (97.4% of the population) lived in households, 599 (1.9%) lived in non-institutionalized group quarters, and 246 (0.8%) were institutionalized. There were 12,347 households, out of which 4,112 (33.3%) had children under the age of 18 living in them, 6,163 (49.9%) were opposite-sex married couples living together, 1,039 (8.4%) had a female householder with no husband present, 371 (3.0%) had a male householder with no wife present. There were 642 (5.2%) unmarried opposite-sex partnerships, and 102 (0.8%) same-sex married couples or partnerships. 3,672 households (29.7%) were made up of individuals and 1,371 (11.1%) had someone living alone who was 65 years of age or older. The average household size was 2.53. There were 7,573 families (61.3% of all households); the average family size was 3.20. In terms of age 7,805 residents (24.4%) were under the age of 18, 1,817 people (5.7%) aged 18 to 24, 9,563 people (29.9%) aged 25 to 44, 8,263 people (25.8%) aged 45 to 64, and 4,578 people (14.3%) who were 65 years of age or older. The median age was 38.7 years. For every 100 females, there were 93.7 males. For every 100 females age 18 and over, there were 91.5 males. There were 13,085 housing units at an average density of 1,336.6 per square mile (516.1/km²), of which 6,927 (56.1%) were owner-occupied, and 5,420 (43.9%) were occupied by renters. The homeowner vacancy rate was 1.1%; the rental vacancy rate was 5.2% | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California 18,972 people (59.2% of the population) lived in owner-occupied housing units and 12,209 people (38.1%) lived in rental housing units. As of the census of 2009, there were 33,690 people, 12,543 households, and 7,248 families residing in the city. The population density was . There were 14,026 housing units at an average density of 1,432.7 per square mile (553.2/km²). 64.2% spoke English, 19.5% Spanish, other Indo-European 4.2%, 4.6% Chinese or Mandarin, and other language 0.7%, as their first language from estimate census 2009. There were 12,543 households out of which 25.8% had children under the age of 18 living with them, 41.5% were married couples living together, 10.8% had a female householder with no husband present, and 45.67% were non-families. 35.1% of all households were made up of individuals and 11.1% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 3.15. In the city, the population was spread out with 25.8% under the age of 18, 9.1% from 18 to 24, 31.5% from 25 to 44, 20.4% from 45 to 64, and 14.2% who were 65 years of age or older. The median age was 32 years. For every 100 females, there were 94.0 males. For every 100 females age 18 and over, there were 90.6 males. As of the 2000 estimate census, the median income for a household in the city was $82,609. Males had a median income of $77,766 versus $59,101 for females. The per capita income for the city was $51,341. About 5.9% of families and 7 | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California 3% of the population were below the poverty line, including 9.8% of those under age 18 and 8.7% of those over age 64. As of 2009 the median income for a family was $123,251. City Council members are elected at-large to staggered, 4-year terms, in non-partisan municipal elections held every two years. On the San Mateo County Board of Supervisors, Menlo Park is split between Supervisorial District 3 (west of El Camino Real) and Supervisorial District 4 (east of El Camino Real). represented by Don Horsley and Warren Slocum, respectively. In the California State Legislature, Menlo Park is in , and in . In the United States House of Representatives, Menlo Park is split between California's 14th (east of Bayshore) and 18th (west of Bayshore) congressional districts, represented by and , respectively. According to the California Secretary of State, as of February 10, 2019, Menlo Park has 19,339 registered voters. Of those, 9,984 (51.6%) are registered Democrats, 2,989 (15.5%) are registered Republicans, and 5,683 (29.4%) have declined to state a political party. For primary schools, the central portions of Menlo Park are served by the Menlo Park City School District, while the Belle Haven neighborhood and VA hospital are served by the Ravenswood City School District, and the Sharon Heights and Stanford Hills neighborhoods served by the Las Lomitas Elementary School District | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California For high school, Menlo Park is part of the Sequoia Union High School District, with all of Menlo Park falling into the boundaries of Menlo-Atherton High School or TIDE Academy, a small high school established in 2019. Catholic parochial schools are St. Raymond Catholic Elementary School and Nativity Elementary School. Peninsula School is a private progressive primary school. Trinity School is an Episcopalian elementary school. Private schools include Phillips Brooks School, a pre-K to 5th grade institution with about 290 students and Alto International School, formerly known as German-American International School, with about 315 students, K-12, is also in the city. For higher education, Saint Patrick's Seminary and University is a Catholic seminary in Menlo Park. Fuller Theological Seminary, an evangelical Christian school, has a branch campus in Menlo Park. There are two libraries within the city, the Main branch and the Belle Haven branch. These libraries are part of the Peninsula Library System and share many resources with other nearby libraries. Much of Menlo Park's economy revolves around the companies on Sand Hill Road, consisting of venture capital, private equity, financial services, law firms, and other professional service companies and investment vehicles focusing on technology. Geron, Robert Half International, Exponent, and SRI International are among the companies based in Menlo Park. Facebook moved its headquarters to the former campus of Sun Microsystems in Menlo Park in December 2011 | https://en.wikipedia.org/wiki?curid=105222 |
Menlo Park, California As of 2012, Facebook announced it would be the biggest employer in Menlo Park at 6,600 employees. According to the city's 2018 "Comprehensive Annual Financial Report", the top employers in the city were: | https://en.wikipedia.org/wiki?curid=105222 |
Willem Hendrik Keesom He also developed the first mathematical description of dipole–dipole interactions in 1921. Thus, dipole–dipole interactions are also known as Keesom interactions. He was previously a student of Heike Kamerlingh Onnes, who had discovered superconductivity (a feat for which Kamerlingh Onnes received the 1913 Nobel Prize in Physics). He also discovered the lambda-point transition specific-heat maximum between Helium-I and Helium-2 in 1930 (Basic Superfluids p25/Tony Guenault). In 1924 he became member of the Royal Netherlands Academy of Arts and Sciences. In 1966, the minor planet "" was named after him. | https://en.wikipedia.org/wiki?curid=113455 |
Surfactant Surfactants are compounds that lower the surface tension (or interfacial tension) between two liquids, between a gas and a liquid, or between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants. The word "surfactant" is a blend of "surface-active agent". Surfactants are usually organic compounds that are amphiphilic, meaning they contain both hydrophobic groups (their "tails") and hydrophilic groups (their "heads"). Therefore, a surfactant contains both a water-insoluble (or oil-soluble) component and a water-soluble component. Surfactants will diffuse in water and adsorb at interfaces between air and water or at the interface between oil and water, in the case where water is mixed with oil. The water-insoluble hydrophobic group may extend out of the bulk water phase, into the air or into the oil phase, while the water-soluble head group remains in the water phase. World production of surfactants is estimated at 15 Mton/y, of which about half are soaps. Other surfactants produced on a particularly large scale are linear alkylbenzene sulfonates (1700 kton/y), lignin sulfonates (600 kton/y), fatty alcohol ethoxylates (700 ktons/y), and alkylphenol ethoxylates (500 kton/y). In the bulk aqueous phase, surfactants form aggregates, such as micelles, where the hydrophobic tails form the core of the aggregate and the hydrophilic heads are in contact with the surrounding liquid | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant Other types of aggregates can also be formed, such as spherical or cylindrical micelles or lipid bilayers. The shape of the aggregates depends on the chemical structure of the surfactants, namely the balance in size between the hydrophilic head and hydrophobic tail. A measure of this is the hydrophilic-lipophilic balance (HLB).Surfactants reduce the surface tension of water by adsorbing at the liquid-air interface. The relation that links the surface tension and the surface excess is known as the Gibbs isotherm. The dynamics of surfactant adsorption is of great importance for practical applications such as in foaming, emulsifying or coating processes, where bubbles or drops are rapidly generated and need to be stabilized. The dynamics of absorption depend on the diffusion coefficient of the surfactant. As the interface is created, the adsorption is limited by the diffusion of the surfactant to the interface. In some cases, there can exist an energetic barrier to adsorption or desorption of the surfactant. If such a barrier limits the adsorption rate, the dynamics are said to be ‘kinetically limited'. Such energy barriers can be due to steric or electrostatic repulsions. The surface rheology of surfactant layers, including the elasticity and viscosity of the layer, play an important role in the stability of foams and emulsions. Interfacial and surface tension can be characterized by classical methods such as the -pendant or spinning drop method. Dynamic surface tensions, i.e | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant surface tension as a function of time, can be obtained by the maximum bubble pressure apparatus The structure of surfactant layers can be studied by ellipsometry or X-Ray reflectivity. Surface rheology can be characterized by the oscillating drop method or shear surface rheometers such as double-cone, double-ring or magnetic rod shear surface rheometer. The human body produces diverse surfactants. Pulmonary surfactant is produced in lungs in order to facilitate breathing by increasing total lung capacity, TLC, and lung compliance. In respiratory distress syndrome or RDS surfactant replacement therapy helps patients have normal respiration by using pharmaceutical forms of the surfactants. One example of pharmaceutical pulmonary surfactants is Survanta (beractant) or its generic form Beraksurf produced by Abbvie and Tekzima respectively. Bile salts play important role in digestion. Most anionic and non-ionic surfactants are nontoxic, having LD50 comparable to sodium chloride. The toxicity of quaternary ammonium compounds, which are antibacterial and antifungal, varies. Dialkyldimethylammonium chlorides (DDAC, DSDMAC) used as fabric softeners have low LD50 (5 g/kg) and are essentially non-toxic, while the disinfectant alkylbenzyldimethylammonium chloride has an LD50 of 0.35 g/kg. Prolonged exposure to surfactants can irritate and damage the skin because surfactants disrupt the lipid membrane that protects skin and other cells | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant Skin irritancy generally increases in the series non-ionic, amphoteric, anionic, cationic surfactants. Surfactants are routinely deposited in numerous ways on land and into water systems, whether as part of an intended process or as industrial and household waste. Anionic surfactants can be found in soils as the result of sludge application, wastewater irrigation, and remediation processes. Relatively high concentrations of surfactants together with multimetals can represent an environmental risk. At low concentrations, surfactant application is unlikely to have a significant effect on trace metal mobility. In the case of Deepwater Horizon oil spill, unprecedented amounts of Corexit were sprayed directly into the ocean at the leak and on the sea-water's surface. The apparent theory being that the surfactants isolate droplets of oil, making it easier for petroleum-consuming microbes to digest the oil. The active ingredient in Corexit is dioctyl sodium sulfosuccinate (DOSS), sorbitan monooleate (Span 80), and polyoxyethylenated sorbitan monooleate (Tween-80)). Because of the volume of surfactants released into the environment, their biodegradation is of great interest. Strategies to enhance degradation include ozone treatment and biodegradation. Two major surfactants, linear alkylbenzene sulfonates (LAS) and the alkyl phenol ethoxylates (APE) break down under aerobic conditions found in sewage treatment plants and in soil to nonylphenol, which is thought to be an endocrine disruptor | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant Interest in biodegradable surfactants has led to much interest in "biosurfactants" such as those derived from amino acids. Attracting much attention is the non-biodegradability of fluorosurfactant, e.g. perfluorooctanoic acid (PFOA). The annual global production of surfactants was 13 million tonnes in 2008. In 2014, the world market for surfactants reached a volume of more than 33 billion US-dollars. Market researchers expect annual revenues to increase by 2.5% per year to around 40.4 billion US-dollars until 2022. The commercially most significant type of surfactants is currently the anionic surfactant alkyl benzene sulfonate (LAS), which is widely used in cleaners and detergents. Surfactants play an important role as cleaning, wetting, dispersing, emulsifying, foaming and anti-foaming agents in many practical applications and products, including detergents, fabric softeners, emulsions, soaps, paints, adhesives, inks, anti-fogs, ski waxes, snowboard wax, deinking of recycled papers, in flotation, washing and enzymatic processes, laxatives. Also agrochemical formulations such as Herbicides (some), insecticides, biocides (sanitizers), and spermicides (nonoxynol-9). Personal care products such as cosmetics, shampoos, shower gel, hair conditioners (after shampoo), toothpastes. Surfactants are used in firefighting and pipelines (liquid drag reducing agents). Alkali surfactant polymers are used to mobilize oil in oil wells | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant The displacement of air from the matrix of cotton pads and bandages so that medicinal solutions can be absorbed for application to various body areas; the displacement of dirt and debris by the use of detergents in the washing of wounds; and the application of medicinal lotions and sprays to surface of skin and mucous membranes. In solution, detergents help solubilize a variety of chemical species by dissociating aggregates and unfolding proteins. Popular surfactants in the biochemistry laboratory are sodium lauryl sulfate (SDS) and cetyl trimethylammonium bromide (CTAB). Detergents are key reagents to extract protein by lysis of the cells and tissues: They disorganize the membrane's lipid bilayer (SDS, Triton X-100, X-114, CHAPS, DOC, and NP-40), and solubilize proteins. Milder detergents such as octyl thioglucoside, octyl glucoside or dodecyl maltoside are used to solubilize membrane proteins such as enzymes and receptors without denaturing them. Non-solubilized material is harvested by centrifugation or other means. For electrophoresis, for example, proteins are classically treated with SDS to denature the native tertiary and quaternary structures, allowing the separation of proteins according to their molecular weight. Detergents have also been used to decellularise organs. This process maintains a matrix of proteins that preserves the structure of the organ and often the microvascular network. The process has been successfully used to prepare organs such as the liver and heart for transplant in rats | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant Pulmonary surfactants are also naturally secreted by type II cells of the lung alveoli in mammals. Surfactants are used with quantum dots in order to manipulate the growth,assembly, and electrical properties of quantum dots, in addition to mediating reactions on their surfaces. Research is ongoing in how surfactants arrange on the surface of the quantum dots. Surfactants play an important role in Droplet-based Microfluidics in the stabilization of the droplets, and the prevention of the fusion of droplets during incubation. The "tails" of most surfactants are fairly similar, consisting of a hydrocarbon chain, which can be branched, linear, or aromatic. Fluorosurfactants have fluorocarbon chains. Siloxane surfactants have siloxane chains. Many important surfactants include a polyether chain terminating in a highly polar anionic group. The polyether groups often comprise ethoxylated (polyethylene oxide-like) sequences inserted to increase the hydrophilic character of a surfactant. Polypropylene oxides conversely, may be inserted to increase the lipophilic character of a surfactant. molecules have either one tail or two; those with two tails are said to be "double-chained". Most commonly, surfactants are classified according to polar head group. A non-ionic surfactant has no charged groups in its head. The head of an ionic surfactant carries a net positive, or negative charge. If the charge is negative, the surfactant is more specifically called anionic; if the charge is positive, it is called cationic | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant If a surfactant contains a head with two oppositely charged groups, it is termed zwitterionic. Commonly encountered surfactants of each type include: Anionic surfactants contain anionic functional groups at their head, such as sulfate, sulfonate, phosphate, and carboxylates. Prominent alkyl sulfates include ammonium lauryl sulfate, sodium lauryl sulfate (sodium dodecyl sulfate, SLS, or SDS), and the related alkyl-ether sulfates sodium laureth sulfate (sodium lauryl ether sulfate or SLES), and sodium myreth sulfate. Others include: Carboxylates are the most common surfactants and comprise the carboxylate salts (soaps), such as sodium stearate. More specialized species include sodium lauroyl sarcosinate and carboxylate-based fluorosurfactants such as perfluorononanoate, perfluorooctanoate (PFOA or PFO). pH-dependent primary, secondary, or tertiary amines; primary and secondary amines become positively charged at pH < 10: octenidine dihydrochloride. Permanently charged quaternary ammonium salts: cetrimonium bromide (CTAB), cetylpyridinium chloride (CPC), benzalkonium chloride (BAC), benzethonium chloride (BZT), dimethyldioctadecylammonium chloride, and dioctadecyldimethylammonium bromide (DODAB). Zwitterionic (amphoteric) surfactants have both cationic and anionic centers attached to the same molecule. The cationic part is based on primary, secondary, or tertiary amines or quaternary ammonium cations | https://en.wikipedia.org/wiki?curid=133176 |
Surfactant The anionic part can be more variable and include sulfonates, as in the sultaines CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) and cocamidopropyl hydroxysultaine. Betaines such as cocamidopropyl betaine have a carboxylate with the ammonium. The most common biological zwitterionic surfactants have a phosphate anion with an amine or ammonium, such as the phospholipids phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, and sphingomyelins. Non-ionic surfactants have covalently bonded oxygen-containing hydrophilic groups, which are bonded to hydrophobic parent structures. The water-solubility of the oxygen groups is the result of hydrogen bonding. Hydrogen bonding decreases with increasing temperature, and the water solubility of non-ionic surfactants therefore decreases with increasing temperature. Non-ionic surfactants are less sensitive to water hardness than anionic surfactants, and they foam less strongly. The differences between the individual types of non-ionic surfactants are slight, and the choice is primarily governed having regard to the costs of special properties (e.g., effectiveness and efficiency, toxicity, dermatological compatibility, biodegradability) or permission for use in food. Fatty acid ethoxylates are a class of very versatile surfactants, which combine in a single molecule the characteristic of a weakly anionic, pH-responsive head group with the presence of stabilizing and temperature responsive ethyleneoxide units. Spans: Tweens: | https://en.wikipedia.org/wiki?curid=133176 |
Overburden pressure Overburden pressure, also called lithostatic pressure, confining pressure or vertical stress, is the pressure or stress imposed on a layer of soil or rock by the weight of overlying material. The Oxford Dictionary of Earth Sciences describes 'confining pressure' as "the combined hydrostatic stress and lithostatic stress; i.e. the total weight of the interstitial pore water and rock above a specified depth." Confining pressure might influence ductile behavior of rocks as well. Ductile behavior is enhanced where high confining pressures are combined with high temperatures and low rates of strain, conditions characteristic of deeper crustal levels. The overburden pressure at a depth z is given by where ρ(z) is the density of the overlying rock at depth z and g is the acceleration due to gravity. p is the datum pressure, the pressure at the surface. In deriving the above equation it is assumed that gravitational acceleration "g" is a constant over "z", since it is placed outside the integral. In reality, "g" is a (non-constant) function of "z" and should appear inside the integral. But since "g" varies little over depths which are a very small fraction of the Earth's radius, it is placed outside the integral in practice for most near-surface applications which require an assessment of lithostatic pressure. In deep-earth geophysics/geodynamics, gravitational acceleration varies significantly over depth and "g" may not be assumed to be constant | https://en.wikipedia.org/wiki?curid=146153 |
Overburden pressure This should be compared with the equivalent concept of hydrostatic pressure in hydrodynamics. | https://en.wikipedia.org/wiki?curid=146153 |
Chemical property A chemical property is any of a material's properties that becomes evident during, or after, a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity. Simply speaking, chemical properties cannot be determined just by viewing or touching the substance; the substance's internal structure must be affected greatly for its chemical properties to be investigated. When a substance goes under a chemical reaction, the properties will change drastically, resulting in chemical change. However, a catalytic property would also be a chemical property. Chemical properties can be contrasted with physical properties, which can be discerned without changing the substance's structure. However, for many properties within the scope of physical chemistry, and other disciplines at the boundary between chemistry and physics, the distinction may be a matter of researcher's perspective. Material properties, both physical and chemical, can be viewed as supervenient; i.e., secondary to the underlying reality. Several layers of superveniency are possible. Chemical properties can be used for building chemical classifications. They can also be useful to identify an unknown substance or to separate or purify it from other substances. Materials science will normally consider the chemical properties of a substance to guide its applications. | https://en.wikipedia.org/wiki?curid=147027 |
Celera Corporation Celera is a subsidiary of Quest Diagnostics which focuses on genetic sequencing and related technologies. It was founded in 1998 as a business unit of Applera, spun off into an independent company in 2008, and finally acquired by Quest Diagnostics in 2011. Originally headquartered in Rockville, Maryland (relocated to Alameda, California), it was established in May 1998 by PE Corporation (later renamed to Applera), with Dr. J. Craig Venter from The Institute for Genomic Research (TIGR) as its first president. While at TIGR, Venter and Hamilton Smith led the first successful effort to sequence an entire organism's genome, that of the "Haemophilus influenzae" bacterium. Celera was formed for the purpose of generating and commercializing genomic information. Its stock is a tracking stock of Applera, along with the tracking stock of Applera's larger Applied Biosystems Group business unit. Celera sequenced the human genome at a fraction of the cost of the public project, approximately $3 billion of taxpayer dollars versus about $300 million of private funding. However, a significant portion of the human genome had already been sequenced when Celera entered the field, and thus Celera did not incur any costs with obtaining the existing data, which was freely available to the public from GenBank. Celera's use of the shotgun strategy spurred the public HGP to change its own strategy, leading to a rapid acceleration of the public effort | https://en.wikipedia.org/wiki?curid=149307 |
Celera Corporation Critics of initial efforts by Celera Genomics to hold back data from sections of genome they sequenced for commercial exploitation felt that it would retard progress in science as a whole. These critics pointed to the open access policy for gene sequences from the publicly funded Human Genome Project. Later, the company changed their policy and made their sequences available for non-commercial use but set a maximum threshold for amount of sequence data that a researcher could download at any given time. The rise and fall of Celera as an ambitious competitor of the Human Genome Project is the main subject of the book "The Genome War" by James Shreeve, who followed Venter around for two years in the process of writing the book. A view from the public effort's side is that of Nobel laureate Sir John Sulston in his book "The Common Thread: A Story of Science, Politics, Ethics and the Human Genome". Anthropologist Paul Rabinow also based his 2005 book "A Machine to Make a Future" on Celera. Eukaryotes: Prokaryotes: | https://en.wikipedia.org/wiki?curid=149307 |
Subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoological names with "-inae". | https://en.wikipedia.org/wiki?curid=151983 |
Speleology is the scientific study of caves and other karst features, as well as their make-up, structure, physical properties, history, life forms, and the processes by which they form (speleogenesis) and change over time (speleomorphology). The term "speleology" is also sometimes applied to the recreational activity of exploring caves, but this is more properly known as "caving", "potholing" (British English), or "spelunking". and caving are often connected, as the physical skills required for "in situ" study are the same. is a cross-disciplinary field that combines the knowledge of chemistry, biology, geology, physics, meteorology, and cartography to develop portraits of caves as complex, evolving systems. Before modern speleology developed, John Beaumont wrote detailed descriptions of some Mendip caves in the 1680s. Prior to the mid-nineteenth century the scientific value of caves was considered only in its contribution to other branches of science, and cave studies were considered part of the larger disciplines of geography, geology or archaeology. Very little cave-specific study was undertaken prior to the work of Édouard-Alfred Martel (1859–1938), the 'father of modern speleology', who through his extensive and well-publicised cave explorations introduced in France the concept of speleology as a distinct area of study. In 1895 Martel founded the Société de Spéléologie, the first organization devoted to cave science in the world. Other early speleologists include Herbert E. Balch | https://en.wikipedia.org/wiki?curid=152630 |
Speleology An international speleological congress was proposed at a meeting in Valence-sur-Rhone, France in 1949 and first held in 1953 in Paris. The International Union of (UIS) was founded in 1965. The growth of speleology is directly linked with that of the sport of caving, both because of the stimulation of public interest and awareness, and the fact that most speleological field-work has been conducted by sport cavers. The creation of an accurate, detailed map is one of the most common technical activities undertaken within a cave. Cave maps, called "surveys", can be used to compare caves to each other by length, depth and volume, may reveal clues on speleogenesis, provide a spatial reference for further scientific study, and assist visitors with route-finding. Caves provide a home for many unique biota. Cave ecologies are very diverse, and not sharply distinct from surface habitats. Generally however, the deeper the cave becomes, the more rarefied the ecology. Cave environments fall into three general categories: Cave organisms fall into three basic classes: There are also so-called "accidental trogloxenes" which are surface organisms that enter caves for no survival reason. Some may even be "troglophobes" (“cave haters”), which cannot survive in caves for any extended period. Examples include deer which fell through a sinkhole, frogs swept into a cave by a flash flood, etc. The two factors that limit cave ecologies are generally energy and nutrients | https://en.wikipedia.org/wiki?curid=152630 |
Speleology To some degree moisture is always available in actively forming Karst caves. Cut off from the sunlight and steady deposition of plant detritus, caves are poor habitats in comparison with wet areas on the surface. The majority of energy in cave environments comes from the surplus of the ecosystems outside. One major source of energy and nutrients in caves is dung from trogloxenes, the majority of which is deposited by bats. Other sources are mentioned above. Cave ecosystems are very fragile. Because of their rarity and position in the ecosystem they are threatened by a large number of human activities. Dam construction, limestone quarrying, water pollution and logging are just some of the disasters that can devastate or destroy underground biological communities. Speleologists also work with archaeologists in studying underground ruins, tunnels, sewers and aqueducts, such as the various inlets and outlets of the Cloaca Maxima in Rome. | https://en.wikipedia.org/wiki?curid=152630 |
Eutectic system A eutectic system ( ) from the Greek "εύ" (eu = well) and "τήξις" (tēxis = melting) is a homogeneous mixture of substances that melts or solidifies at a single temperature that is lower than the melting point of any of the constituents. The eutectic temperature is the lowest possible melting temperature over all of the mixing ratios for the involved component species. Upon heating any other mixture ratio, and reaching the eutectic temperature – see the adjacent phase diagram – one component's lattice will melt first, while the temperature of the mixture has to further increase for (all) the other component lattice(s) to melt. Conversely, as a non-eutectic mixture cools down, each mixture's component will solidify (form its lattice) at a distinct temperature, until all material is solid. The coordinates defining a "eutectic point" on a phase diagram are the "eutectic percentage ratio" (on the atomic/molecular ratio axis of the diagram) and the "eutectic temperature" (on the temperature axis of the diagram). Not all binary alloys have eutectic points because the valence electrons of the component species are not always compatible, in any mixing ratio, to form a new type of joint crystal lattice. For example, in the silver-gold system the melt temperature (liquidus) and freeze temperature (solidus) "meet at the pure element endpoints of the atomic ratio axis while slightly separating in the mixture region of this axis". The term was coined in 1884 by British physicist and chemist Frederick Guthrie (1833–1886) | https://en.wikipedia.org/wiki?curid=152969 |
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