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John G. Anderson (born 1948) is an American seismologist and Professor at the University of Nevada, Reno. Anderson specializes in studies of strong ground motion and seismic hazards. He was Director of the Nevada Seismological Laboratory from 1998-2009. He has published more than 150 articles and more than 90 abstracts. He completed a PhD in Geophysics from Columbia University in 1976 and a bachelor of science in physics from Michigan State University in 1970. He received his high school diploma in 1966.
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https://en.wikipedia.org/wiki?curid=1611373
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Gimenez stain The Gimenez staining technique uses biological stains to detect and identify bacterial infections in tissue samples. Although largely superseded by techniques like Giemsa staining, the Gimenez technique may be valuable for detecting certain slow-growing or fastidious bacteria. Basic fuchsin stain in aqueous solution with phenol and ethanol colours many bacteria (both gram positive and Gram negative) red, magenta, or pink. A malachite green counterstain gives a blue-green background cast to the surrounding tissue.
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https://en.wikipedia.org/wiki?curid=1611956
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Index of genetics articles Genetics (from Ancient Greek ', “genite” and that from ', “origin”), a discipline of biology, is the science of heredity and variation in living organisms. Articles (arranged alphabetically) related to genetics include:
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https://en.wikipedia.org/wiki?curid=1612722
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Marek Huberath Marek S. Huberath (pen name, born 1954) is a Polish professor of physics in the Jagiellonian University in Kraków and an award-winning science fiction and fantasy writer. His themes are philosophical, moral, and religious: how people become beasts or remain human in extreme circumstances. Many of his stories focus on death. Winner of the Zajdel Award in 1991 for a short story "Kara większa" and in 1997 for his novel "Gniazdo Światów".
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https://en.wikipedia.org/wiki?curid=1614365
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International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use The (ICH) is an initiative that brings together regulatory authorities and pharmaceutical industry to discuss scientific and technical aspects of pharmaceutical product development and registration. The mission of the ICH is to promote public health by achieving greater harmonisation through the development of technical Guidelines and requirements for pharmaceutical product registration. Harmonisation leads to a more rational use of human, animal and other resources, the elimination of unnecessary delay in the global development, and availability of new medicines while maintaining safeguards on quality, safety, efficacy, and regulatory obligations to protect public health. As per the public health ICH must include the professional qualifications in their requirements on the aspect of pharmacists must be qualified and organisations must be included only pharmacist related of all health organisation. In the 1980s the European Union began harmonising regulatory requirements. In 1989, Europe, Japan, and the United States began creating plans for harmonisation. The International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) was created in April 1990 at a meeting in Brussels
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https://en.wikipedia.org/wiki?curid=1616138
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International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use ICH had the initial objective of coordinating the regulatory activities of the European, Japanese and United States regulatory bodies in consultation with the pharmaceutical trade associations from these regions, to discuss and agree the scientific aspects arising from product registration. Since the new millennium, ICH's attention has been directed towards extending the benefits of harmonisation beyond the founding ICH regions. In 2015, ICH underwent several reforms and changed its name to the while becoming a legal entity in Switzerland as a non-profit association. The aim of these reforms was to transform ICH into a truly global initiative supported by a robust and transparent governance structure. The ICH Association established an Assembly as the over-arching governing body with the aim of focusing global pharmaceutical regulatory harmonisation work in one venue that allows pharmaceutical regulatory authorities and concerned industry organisations to be more actively involved in ICH’s harmonisation work. The new Assembly met for the first time on 23 October 2015. The ICH comprises the following bodies: The ICH Assembly brings together all Members and Observers of the ICH Association as the overarching governing body of ICH. It adopts decisions in particular on matters such as on the adoption of ICH Guidelines, admission of new Members and Observers, and the ICH Association’s work plans and budget
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https://en.wikipedia.org/wiki?curid=1616138
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International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use Member representatives appointed to the Assembly are supported by ICH Coordinators who represent each Member to the ICH Secretariat on a daily basis. The ICH Management Committee (MC) is the body that oversees operational aspects of ICH on behalf of all Members, including administrative and financial matters and oversight of the Working Groups (WGs). The MedDRA Management Committee (MC) has responsibility for direction of MedDRA, ICH’s standardised medical terminology. The MedDRA MC has the role of managing, supporting, and facilitating the maintenance, development, and dissemination of MedDRA. The ICH Secretariat is responsible for day-to-day management of ICH, coordinating ICH activities as well as providing support to the Assembly, the MC and Working Groups. The ICH Secretariat also provides support for the MedDRA MC. The ICH Secretariat is located in Geneva, Switzerland. The ICH WGs are established by the Assembly when a new technical topic is accepted for harmonisation, and are charged with developing a harmonised guideline that meets the objectives outlined in the Concept Paper and Business Plan. Face-to-face meetings of the WG will normally only take place during the biannual ICH meetings. Interim reports are made at each meeting of the Assembly and made publicly available on the ICH website. ICH harmonisation activities fall into 4 categories: Formal ICH Procedure, Q&A Procedure, Revision Procedure and Maintenance Procedure, depending on the activity to be undertaken
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https://en.wikipedia.org/wiki?curid=1616138
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International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use The development of a new harmonised guideline and its implementation (the formal ICH procedure) involves 5 steps: The WG works to prepare a consensus draft of the Technical Document, based on the objectives set out in the Concept Paper. When consensus on the draft is reached within the WG, the technical experts of the WG will sign the "Step 1" Experts sign-off sheet. The "Step 1" Experts Technical Document is then submitted to the Assembly to request adoption under "Step 2" of the ICH process. "Step 2a" is reached when the Assembly agrees, based on the report of the WG, that there is sufficient scientific consensus on the technical issues for the Technical Document to proceed to the next stage of regulatory consultation. The Assembly then endorses the "Step 2a" Technical Document. "Step 2b" is reached when the Regulatory Members of the Assembly further endorse the draft Guideline. "Step 3" occurs in three distinct stages: regulatory consultation, discussion, and finalisation of the "Step 3" Expert Draft Guideline. "Step 4" is reached when the Regulatory Members of the Assembly agree that there is sufficient scientific consensus on the draft Guideline and adopt the ICH Harmonised Guideline. The ICH Harmonised Guideline moves immediately to the final step of the process that is the regulatory implementation. This step is carried out according to the same national/regional procedures that apply to other regional regulatory guidelines and requirements in the ICH regions
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https://en.wikipedia.org/wiki?curid=1616138
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International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use Information on the regulatory action taken and implementation dates are reported back to the Assembly and published by the ICH Secretariat on the ICH website. The ICH topics are divided into four categories and ICH topic codes are assigned according to these categories: ICH Guidelines are not mandatory for anybody per se but the strength of the ICH process lies in the commitment for implementation by ICH Regulatory Members using appropriate national/regional tools. MedDRA is a rich and highly specific standardised medical terminology developed by ICH to facilitate sharing of regulatory information internationally for medical products used by humans. It is used for registration, documentation and safety monitoring of medical products both before and after a product has been authorised for sale. Products covered by the scope of MedDRA include pharmaceuticals, vaccines and drug-device combination products.
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https://en.wikipedia.org/wiki?curid=1616138
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Coefficient of haze The coefficient of haze (also known as smoke shade) is a measurement of visibility interference in the atmosphere. One way to measure this is to draw about 1000 cubic feet of air sample through an air filter and obtain the radiation intensity through the filter. The coefficient is then calculated based on the absorbance formula where formula_2 is the radiation (400 nm light) intensity transmitted through the sampled filter, and formula_3 is the radiation intensity transmitted through a clean (control) filter.
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https://en.wikipedia.org/wiki?curid=1616977
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Horațiu Năstase Horaţiu Năstase is a Romanian physicist and professor in the String Theory group at Instituto de Física Teórica of the Universidade Estadual Paulista in São Paulo, Brazil. He was born in Bucharest, Romania, and finished high school at Nicolae Bălcescu High School (now Saint Sava National College). He did his undergraduate studies in the Physics Department of the University of Bucharest, graduating in 1995. His last year there he studied at the Niels Bohr Institute (NBI), Copenhagen University, with a scholarship which continued into the following year. In 1996 he joined the Physics Department of the State University of New York at Stony Brook from which he received his PhD in May 2000. From 2000 to 2002 he was a postdoc at the Institute for Advanced Study in Princeton, after which he was an assistant research professor at Brown University until 2006. From 2007 to 2009 he was an assistant professor at the Global Edge Institute of the Tokyo Institute of Technology in Japan. Since 2010, Nastase holds a permanent position as assistant professor at IFT-UNESP in Brazil. Năstase attracted some media attention in 2005 by arguing that string theory could be tested by the Relativistic Heavy Ion Collider, through the AdS/CFT correspondence . He is also known for his work in 2002 with David Berenstein and Juan Maldacena to investigate the duality between strings on pp-wave spacetime and "BMN operators" in supersymmetric Yang–Mills theory.
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https://en.wikipedia.org/wiki?curid=1617963
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Wilting is the loss of of non-woody parts of plants. This occurs when the turgor pressure in non-lignified plant cells falls towards zero, as a result of diminished water in the cells. also serves to reduce water loss, as it makes the leaves expose less surface area. The rate of loss of water from the plant is greater than the absorption of water in the plant. The process of wilting modifies the leaf angle distribution of the plamore erectophil Lower water availability may result from: diminishes the plant's ability to transpire and grow. Permanent wilting leads to plant death. Symptoms of wilting and blights resemble one another. The plants may recover during the night when evaporation is reduced as the stomata closes. In woody plants, reduced water availability leads to cavitation of the xylem. occurs in plants such as balsam and holy basil. is an effect of the plant growth-inhibiting hormone, abscisic acid. With cucurbits, wilting can be caused by the squash vine borer.
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https://en.wikipedia.org/wiki?curid=1618993
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Marine Modeling and Analysis Branch The United States (MMAB) is part of the Environmental Modeling Center, which is responsible for the development of improved numerical weather and marine prediction modeling systems within NCEP/NWS. It provides analysis and real-time forecast guidance (1–16 days) on marine meteorological, oceanographic, and cryospheric parameters over the global oceans and coastal areas of the US. Products include:
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https://en.wikipedia.org/wiki?curid=1619885
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National Centers for Environmental Prediction The United States (NCEP) delivers national and global weather, water, climate and space weather guidance, forecasts, warnings and analyses to its Partners and External User Communities. These products and services are based on a service-science legacy and respond to user needs to protect life and property, enhance that nation's economy and support the nation's growing need for environmental information. The centers form part of the National Weather Service. There are nine centers:
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https://en.wikipedia.org/wiki?curid=1619931
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Accessory cloud An accessory cloud is a cloud which is dependent on a larger cloud system for its development and continuance. It is often an appendage but also can be adjacent to the parent cloud system. The arcus and roll clouds, shelf cloud, wall cloud, and scud are examples of low level or vertical accessory clouds whilst the anvil, and overshooting top, are examples of high level accessory clouds. The condensation funnel of funnel clouds and tornadoes are also accessory clouds. They are associated with deep moist convection and especially cumulonimbus, the primary cloud producing thunderstorms. The pileus and mammatus types can form at various altitude ranges depending on the main clouds with which they are associated. The World Meteorological Organization classifies most accessory clouds as "supplementary features". The height range classification of a supplementary feature is the same as the parent cloud. As an example, the anvil cloud (supplementary feature incus) forms at high altitude but is not classified by the WMO as a high cloud because of its association with the genus cumulonimbus. It is "very rare" for any accessory cloud to generate its own precipitation. However, the parent cloud may generate precipitation. Precipitation from the parent cloud is often confused with the accessory cloud and observers think that the precipitation is actually falling from the accessory cloud.
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https://en.wikipedia.org/wiki?curid=1621815
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Dry punch A dry punch is meteorological slang for a synoptic scale or mesoscale process. A dry punch at the surface results in a dry line bulge. A dry punch aloft above an area of warm, moist (buoyant) air at low levels often increases the potential for severe thunderstorms.
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https://en.wikipedia.org/wiki?curid=1621894
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Bulk Richardson number The Bulk Richardson Number (BRN) is an approximation of the Gradient Richardson number. The BRN is a dimensionless ratio in meteorology related to the consumption of turbulence divided by the shear production (the generation of turbulence kinetic energy caused by wind shear) of turbulence. It is used to show dynamic stability and the formation of turbulence. The BRN is used frequently in meteorology due to widely available rawinsonde (frequently called radiosonde) data and numerical weather forecasts that supply wind and temperature measurements at discrete points in space. Below is the formula for the BRN. Where g is gravitational acceleration, "T" is absolute virtual temperature, Δθ is the virtual potential temperature difference across a layer of thickness Δ"z" (vertical depth), and Δ"U" and Δ"V" are the changes in horizontal wind components across that same layer. High values indicate unstable and/or weakly-sheared environments; low values indicate weak instability and/or strong vertical shear. Generally, values in the range of around 10 to 50 suggest environmental conditions favorable for supercell development. In the limit of layer thickness becoming small, the approaches the Gradient Richardson number, for which a critical Richardson number is roughly Ri= 0.25. Numbers less than this critical value are dynamically unstable and likely to become or remain turbulent. The critical value of 0.25 applies only for local gradients, not for finite differences across thick layers
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Bulk Richardson number The thicker the layer is the more likely we are to average out large gradients that occur within small sub-regions of the layer of interest. This results in uncertainty of our prediction of the occurrence of turbulence, and now one must use an artificially large value of the critical Richardson number to give reasonable results using our smoothed gradients. This means that the thinner the layer, the closer the value to the theory.
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https://en.wikipedia.org/wiki?curid=1621913
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Pospiviroid is a genus of viroids that most commonly infects tubers. It belongs to the family pospiviroidae. The first viroid discovered was a pospiviroid, the PSTVd species (potato spindle tuber viroid).
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https://en.wikipedia.org/wiki?curid=1624084
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Beehive shelf A beehive shelf is a piece of laboratory equipment, usually of pottery, used to support a receiving jar or tube while a gas is being collected over water with a pneumatic trough. It is used so that when the gas emerges from the delivery tube into the beehive shelf, it is funneled into the receiving jar instead of being released elsewhere. The name derives from the design of early beehives made from bound grass called a skep. The squat circular shape was made by binding the grass bundles to form a flat wheel. Sides were added using the same material with a cutout to allow honey bees to enter and leave the hive.
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https://en.wikipedia.org/wiki?curid=1627917
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Ganesa Macula is a dark feature on Saturn's moon Titan. It is named after the Hindu god Ganesha. Ganesa was formerly tentatively identified as a cryovolcanic dome: the result of a mixture of water and ammonia erupting from the center of the dome and spreading out to form a pancake-like deposit. However, topographical data have since shown that it is not dome-shaped, and as a result, there is no longer any evidence that it is of volcanic origin.
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https://en.wikipedia.org/wiki?curid=1628823
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Verona Rupes is a cliff on Miranda, a moon of Uranus. The cliff face, previously thought to be from high, as of 2016 is estimated to be high, which makes it the tallest known cliff in the Solar System. It may have been created by a major impact, which caused the moon to disrupt and reassemble, or by the crust rifting. Given Miranda's low gravity, it would take about 12 minutes to fall from the top, reaching the bottom at the speed of about 200 km/h. Even so, the fall might be survivable given proper airbag protection.
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https://en.wikipedia.org/wiki?curid=1630505
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Hecates Tholus is a Martian volcano, notable for results from the European Space Agency's Mars Express mission which indicate a major eruption took place 350 million years ago. The eruption created a caldera 10 km in diameter. It has been suggested that glacial deposits later partly filled the caldera and an adjacent depression. Crater counts indicate this happened as recently as 5 to 20 million years ago. However climate models show that ice is not stable at today, pointing to climate change since the glaciers were active. It has been shown that the age of the glaciers correspond to a period of increased obliquity of Mars' rotational axis. The volcano is at location 32.12°N 150.24°E, in the volcanic province Elysium, and has a diameter of 182 km. It is the northernmost of the Elysium volcanoes; the others are Elysium Mons and Albor Tholus. is in the Cebrenia quadrangle. In planetary nomenclature, a "tholus" is a "small domical mountain or hill". Hecates is named after Hecate, the goddess of the ghost-world, nightly events, and sorcery.
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https://en.wikipedia.org/wiki?curid=1631131
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Biolex Therapeutics was a biotechnology firm in the Research Triangle of North Carolina that was founded in 1997 and raised $190 million from investors. It filed for Chapter 7 bankruptcy on July 5, 2012. The company focused on expression of difficult-to-synthesize recombinant proteins in its LEX platform, which used "Lemna", a duckweed. The duckweeds are a family of small aquatic plants that can be grown in sterile culture. developed recombinant DNA technology for efficiently producing pharmaceutical proteins in Lemna. Therapeutic glycosylated proteins, including monoclonal antibodies and interferon (IFN-alpha2b) have been produced using the LEX platform. acquired Epicyte Pharmaceutical Inc. on May 6, 2004, and acquired LemnaGene SA of Lyon, France in 2005. was a privately held company, originally backed by Quaker BioVentures, The Trelys Funds, and Polaris Venture Partners. The term "plantibody" is trademarked by Biolex. In May 2012 announced that it sold the LEX System to Synthon, a Netherlands-based specialty pharmaceutical company. The sale included two preclinical biologics made with the LEX System, BLX-301, a humanized and glyco-optimized anti-CD20 antibody for non-Hodgkin's B-cell lymphoma and other B-cell malignancies and BLX-155, a direct-acting thrombolytic. The financial terms of the sale were not disclosed.
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https://en.wikipedia.org/wiki?curid=1631144
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Hydrobromide In chemistry, a hydrobromide is an acid salt resulting, or regarded as resulting, from the reaction of hydrobromic acid with an organic base (e.g. an amine). The compounds are similar to hydrochlorides. Some drugs are formulated as hydrobromides, eg. eletriptan hydrobromide.
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https://en.wikipedia.org/wiki?curid=1632111
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Jayme Tiomno (April 16, 1920 in Rio de Janeiro – January 12, 2011 in Rio de Janeiro) was a Brazilian experimental and theoretical physicist with interests in particle physics and general relativity. He was member of the Brazilian Academy of Sciences and a recipient of the Brazilian Order of Scientific Merit. He was the son of Jewish Russian immigrants. He was a founder of the CBPF - Centro Brasileiro de Pesquisas Físicas (Brazilian Center of Physics Research) and one responsible for the creation of the Brazilian Physical Society.
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https://en.wikipedia.org/wiki?curid=1632637
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Gleb Wataghin Gleb Vassielievich Wataghin (November 3, 1899 in Birzula, Russian Empire – October 10, 1986 in Turin, Italy) was a Russian-Italian experimental physicist and a great scientific leader who gave a great impulse to the teaching and research on physics in two continents: in the University of São Paulo, São Paulo, Brazil; and in the University of Turin, Turin, Italy. Wataghin was hired in 1934 to found with other European physicists the Department of Physics of the recently founded University of São Paulo. There, he was the tutor of a group of young physicists, such as César Lattes, Oscar Sala, Mário Schenberg, Roberto Salmeron, Marcelo Damy de Souza Santos and Jayme Tiomno. The Institute of Physics of the State University of Campinas, in Campinas, Brazil, was named in his honour, as well as a prize in Physics. In 1955, he received a honorary doctorate from the University of São Paulo. He was awarded the Feltrinelli Prize in 1951 and was national member of the Accademia Nazionale dei Lincei, from 1960.
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https://en.wikipedia.org/wiki?curid=1632820
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Nuclear transfer is a form of cloning. The steps involve removing the DNA from an oocyte (unfertilised egg), and injecting the nucleus which contains the DNA to be cloned. In rare instances, the newly constructed cell will divide normally, replicating the new DNA while remaining in a pluripotent state. If the cloned cells are placed in the uterus of a female mammal, a cloned organism develops to term in rare instances. This is how Dolly the Sheep and many other species were cloned. Cows are commonly cloned to select those that have the best milk production. On 24 January 2018, two monkey clones were reported to have been created with the technique for the first time. Despite this, the low efficiency of the technique has prompted some researchers, notably Ian Wilmut, creator of Dolly the cloned sheep, to abandon it. is a delicate process that is a major hurdle in the development of cloning technology. Materials used in this procedure are a microscope, a holding pipette (small vacuum) to keep the oocyte in place, and a micropipette (hair-thin needle) capable of extracting the nucleus of a cell using a vacuum. For some species, such as mouse, a drill is used to pierce the outer layers of the oocyte. Various chemical reagents are used to increase cloning efficiency. Microtubule inhibitors, such as nocodazole, are used to arrest the oocyte in M phase, during which its nuclear membrane is dissolved. Chemicals are also used to stimulate oocyte activation. When applied the membrane is completely dissolved
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https://en.wikipedia.org/wiki?curid=1632972
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Nuclear transfer Somatic Cell Nuclear Transfer (SCNT) is the process by which the nucleus of an oocyte (egg cell) is removed and is replaced with the nucleus of a somatic (body) cell (examples include skin, heart, or nerve cell). The two entities fuse to become one and factors in the oocyte cause the somatic nucleus to reprogram to a pluripotent state. The cell contains genetic information identical to the donated somatic cell. After stimulating this cell to begin dividing, in the proper conditions an embryo will develop. Stem cells can be extracted 5–6 days later and used for research. Genomic reprogramming is the key biological process behind nuclear transfer. Currently unidentified reprogramming factors present in oocytes are capable of initiating a cascade of events that can reset the mature, specialized cell back to an undifferentiated, embryonic state. These factors are thought to be mainly proteins of the nucleus.
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https://en.wikipedia.org/wiki?curid=1632972
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Conamara Chaos is a region of chaotic terrain on Jupiter's moon Europa. It is named after Connemara () in Ireland due to its similarly rugged landscape. is a landscape produced by the disruption of the icy crust of Europa. The region consists of rafts of ice that have moved around and rotated. Surrounding these plates is a lower matrix of jumbled ice blocks which may have been formed as water, slush, or warm ice rose up from below the surface. The region is cited as evidence for a liquid ocean below Europa's icy surface.
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https://en.wikipedia.org/wiki?curid=1633910
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Protozoology is the study of protozoa, the "animal-like" (i.e., motile and heterotrophic) protists. This term has become dated as understanding of the evolutionary relationships of the eukaryotes has improved. For example, the Society of Protozoologists, founded in 1947, was renamed International Society of Protistologists in 2005. However, the term persists in some cases (e.g., the Polish journal "Acta Protozoologica"). Example:- Study of Amoeba and plasmodium done this branch
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https://en.wikipedia.org/wiki?curid=1633982
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Wilhem de Haan (7 February 1801 in Amsterdam – 15 April 1855 in Leiden) was a Dutch zoologist. He specialised in the study of insects and crustaceans, and was the first keeper of invertebrates at the Rijksmuseum in Leiden, now Naturalis. He was forced to retire in 1846, when he was partially paralysed by a spinal disease. He was responsible for the invertebrate volume of Siebold's "Fauna Japonica", which was published in 1833, and introduced the western world for the first time to Japanese wildlife. He named a great many new taxa, and several taxa are named in his honour. He published significant work on both mantids and phasmids (1842).
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https://en.wikipedia.org/wiki?curid=1634562
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Pullulanase (, "limit dextrinase", "amylopectin 6-glucanohydrolase", "bacterial debranching enzyme", "debranching enzyme", "alpha-dextrin endo-1,6-alpha-glucosidase", "R-enzyme", "pullulan alpha-1,6-glucanohydrolase") is a specific kind of glucanase, an amylolytic exoenzyme, that degrades pullulan. It is produced as an extracellular, cell surface-anchored lipoprotein by Gram-negative bacteria of the genus "Klebsiella". Type I pullulanases specifically attack α-1,6 linkages, while type II pullulanases are also able to hydrolyse α-1,4 linkages. It is also produced by some other bacteria and archaea. is used as a processing aid in grain processing biotechnology (production of ethanol and sweeteners). is also known as pullulan-6-glucanohydrolase (Debranching enzyme). Its substrate, pullulan, is regarded as a chain of maltotriose units linked by alpha-1,6-glycosidic bonds. will hydrolytically cleave pullulan (alpha-glucan polysaccharides).
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https://en.wikipedia.org/wiki?curid=1639710
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Lamella (materials) A lamella (plural "lamellae") is a small plate or flake, from the Latin, and may also be used to refer to collections of fine sheets of material held adjacent to one another, in a gill-shaped structure, often with fluid in between though sometimes simply a set of 'welded' plates. The term is used in biological and engineering contexts, such as filters and heat exchangers. The microscopic structures in bone and nacre are lamellae in the materials science sense of the word. In surface chemistry (especially mineralogy and materials science), lamellar structures are fine layers, alternating between different materials. They can be produced by chemical effects (as in eutectic solidification), biological means, or a deliberate process of lamination, such as pattern welding. Lamellae can also describe the layers of atoms in the crystal lattice of a material such as a metal. The term has been used to describe the construction of lamellar armour, as well as the layered structures that can be described by a lamellar vector field. In a water-treatment context, lamellar filters may be referred to as "plate filters" or "tube filters". This term is used to describe a certain type of ichthyosis, a congenital skin condition. Lamellar Ichthyosis often presents with a "colloidal" membrane at birth. It is characterized by generalized dark scaling. The term "lamella(e)" is used in the flooring industry to describe the finished top-layer of an engineered wooden floor
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https://en.wikipedia.org/wiki?curid=1641702
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Lamella (materials) For example, an engineered walnut floor will have several layers of wood and a top walnut lamella. In archaeology the term is used for a variety of small flat and thin objects, such as Amulet MS 5236, a very thin gold plate with a stamped text from Ancient Greece in the 6th century BC. In textiles, lamella is thin metallic strip used alone or wound around a core thread for goldwork embroidery and tapestry weaving. In September 2010, the U.S. Food and Drug Administration (FDA) announced a recall of two medications which contained "extremely thin glass flakes (lamellae) that are barely visible in most cases. The lamellae result from the interaction of the formulation with glass vials over the shelf life of the product."
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Homolysis (chemistry) In chemistry, homolysis (from Greek ὅμοιος, homoios, "equal," and λύσις, lusis, "loosening") or homolytic fission is chemical bond dissociation of a molecule by a process where each of the fragments retains one of the originally bonded electrons. During homolytic fission of a neutral molecule with an even number of electrons, two free radicals will be generated. That is, the two electrons involved in the original bond are distributed between the two fragment species. The energy involved in this process is called bond dissociation energy. Bond cleavage is also possible by a process called heterolysis. Because of the relatively high energy required to break bonds in this manner, homolysis only occurs under certain circumstances:
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https://en.wikipedia.org/wiki?curid=1648241
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Galvanoluminescence Is the emission of light produced by the passage of an electric current through an appropriate electrolyte in which an electrode, made of certain metals such as aluminium or tantalum, has been immersed. An example being the electrolysis of sodium bromide (NaBr).
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https://en.wikipedia.org/wiki?curid=1650455
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Mindel glaciation The (, also "Mindel-Glazial", "Mindel-Komplex" or, colloquially, "Mindel-Eiszeit") is the third oldest glacial stage in the Alps. Its name was coined by Albrecht Penck and Eduard Brückner, who named it after the Swabian river, the Mindel. The Mindel glacial occurred in the Middle Pleistocene; it was preceded by the Haslach-Mindel interglacial (often regarded as part of Günz) and succeeded by the Mindel-Riss interglacial (Holstein interglacial). The is commonly correlated to the Elster glaciation of northern Europe. The more precise timing is controversial since Mindel is commonly correlated to two different marine isotope stages, MIS 12 (478-424 thousand years ago) and MIS 10 (374-337 thousand years ago). This ambiguity is much related to the correlation problem described in more detail in the article 'Elster glaciation'.
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Foe (unit) A foe is a unit of energy equal to 10 joules or 10 ergs, used to express the large amount of energy released by a supernova. An acronym for "[ten to the power of] fifty-one ergs", the term was introduced by Gerald E. Brown of Stony Brook University in his work with Hans Bethe, because "it came up often enough in our work". Without mentioning the foe, Steven Weinberg proposed in 2006 "a new unit called the bethe" (B) with the same value, to "replace" it. This unit of measure is convenient because a supernova typically releases about one foe of observable energy in a very short period (which can be measured in seconds). In comparison, if the Sun had its current luminosity throughout its entire lifetime, it would release 3.827 W × 3.1536 s/yr × 10 yr ≈ 1.2 foe. One solar mass has a rest mass energy of 1787 foe.
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Alexander Keith Johnston (1844–1879) Alexander Keith Johnston (11 November 1844 in Edinburgh28 June 1879 in Tanzania) was a Scottish explorer, cartographer and geographer. He was the son of published geographer Alexander Keith Johnston (1804–1871) and Mary Grey. From 1873 to 1875 he was geographer to a commission for the survey of Paraguay. He led a Royal Geographical Society expedition to Lake Nyasa and Lake Tanganyika. After only six weeks of the expedition Johnston died from malaria and dysentry in the village of Beho Beho in what is now the Selous Game Reserve, Tanzania . He was accompanied by fellow Scot Joseph Thomson (explorer) who successfully completed the expedition. Several expeditions were conducted by * Mike Shand (University of Glasgow) to find the grave of Keith Johnston at Behobeho between 2001 and 2004. The grave searches have been documented in a chapter of the book *Wild Heart of Africa - The Selous Game Reserve in Tanzania, edited by Rolf Baldus and published by Rowland Ward in 2009. He is memorialised on his father's grave in Grange Cemetery in Edinburgh.
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Felix Karrer (March 1825 – 19 April 1903) was an Austrian geologist. He was born in Venice, educated in Vienna, and served for a time in the war department, but he retired from the public service at the age of thirty-two, and devoted himself to science. He made especial studies of the Tertiary formations and fossils of the Vienna Basin, and investigated the geological relations of the thermal and other springs in that region. He became an authority on the foraminifera, on which subject he published numerous papers. He wrote also a little book entitled "Der Boden der Hauptstädte Europas" (1881). He died in Vienna.
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Karl Johann Bernhard Karsten (26 November 1782 – 22 August 1853) was a German mineralogist known for contributions made to the German metallurgy industry. He was born at Bützow in Mecklenburg-Schwerin and initially studied law in Rostock. From 1801 he devoted his time to mining and metallurgy. In 1819 he was named mining councilor to the Ministry of the Interior in Berlin. He was a major factor in the emergence of the zinc industry in Silesia. He was author of several comprehensive works, including: He was well known as editor of the "Archiv für Bergbau und Hüttenwesen" (Archive for mining and metallurgy; 20 volumes, 1818-1831); and (with Ernst Heinrich Karl von Dechen) of the "Archiv für Mineralogie, Geognosie, Bergbau und Hüttenkunde" (26 volumes, 1829-1854). He died at Berlin in 1853. His son, Dr. Hermann Karsten (1809-1877), was a professor of mathematics and physics at the University of Rostock.
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Her Majesty's Botanist His/is a member of the Royal household in Scotland. The office was created in 1699, and from 1768 until 1956 it was combined with the office of Regius Keeper of the Royal Botanic Garden Edinburgh, who also held the post of Regius Professor of Botany at the University of Edinburgh. Since then the office of HM Botanist has been honorary, but conferred on a serving or retired Regius Keeper.
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Turion (botany) A turion (from Latin turio meaning "shoot") is a type of bud that is capable of growing into a complete plant. A turion may be an underground bud. Many members of the genus "Epilobium" are known to produce turions at or below ground level. Some aquatic plant species produce overwintering turions, especially in the genera "Potamogeton", "Myriophyllum", "Aldrovanda" and "Utricularia". These plants produce turions in response to unfavourable conditions such as decreasing day-length or reducing temperature. They are derived from modified shoot apices and are often rich in starch and sugars enabling them to act as storage organs. Although they are hardy (frost resistant), it is probable that their principal adaptation is their ability to sink to the bottom of a pond or lake when the water freezes. Because water expands anomalously at lower temperatures, water at is denser than colder water and stays at the bottom, and in this water turions over-winter before rising again in the spring. Some turions or aquatic plants also exhibit drought resistance allowing them to survive in temporary pools.
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Laboratory sample tube Laboratory sample tubes are used to hold small quantities of substances undergoing experimentation or testing. These tubes are usually made of glass and vary in size and purpose. Laboratory sample tubes must not be confused with glass tubing, which can be used to carry fluid between laboratory equipment. Example laboratory sample tubes are listed below:
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Abell 754 is a galaxy cluster in the constellation Hydra that was formed from the collision of two smaller clusters. This collision, which began about 300 million years ago, is ongoing, and the system is still disturbed. Eventually, the cluster will reach a level of equilibrium in a few billion years.
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Invariable plane The invariable plane of a planetary system, also called Laplace's invariable plane, is the plane passing through its barycenter (center of mass) perpendicular to its angular momentum vector. In the Solar System, about 98% of this effect is contributed by the orbital angular momenta of the four jovian planets (Jupiter, Saturn, Uranus, and Neptune). The invariable plane is within 0.5° of the orbital plane of Jupiter, and may be regarded as the weighted average of all planetary orbital and rotational planes. This plane is sometimes called the "Laplacian" or "Laplace plane" or the "invariable plane of Laplace", though it should not be confused with the Laplace plane, which is the plane about which the orbital planes of planetary satellites precess. Both derive from the work of (and are at least sometimes named for) the French astronomer Pierre Simon Laplace. The two are equivalent only in the case where all perturbers and resonances are far from the precessing body. The invariable plane is simply derived from the sum of angular momenta, and is "invariable" over the entire system, while the Laplace plane may be different for different orbiting objects within a system. Laplace called the invariable plane the "plane of maximum areas", where the area is the product of the radius and its differential time change , that is, its radial velocity, multiplied by the mass
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Invariable plane The magnitude of the orbital angular momentum vector of a planet is where formula_1 is the orbital radius of the planet (from the barycenter), formula_2 is the mass of the planet, and formula_3 is its orbital angular velocity. That of Jupiter contributes the bulk of the Solar System's angular momentum, 60.3%. Then comes Saturn at 24.5%, Neptune at 7.9%, and Uranus at 5.3%. The Sun forms a counterbalance to all of the planets, so it is near the barycenter when Jupiter is on one side and the other three jovian planets are diametrically opposite on the other side, but the Sun moves to 2.17 solar radii away from the barycenter when all jovian planets are in line on the other side. The orbital angular momenta of the Sun and all non-jovian planets, moons, and small Solar System bodies, as well as the axial rotation momenta of all bodies, including the Sun, total only about 2%. If all Solar System bodies were point masses, or were rigid bodies having spherically symmetric mass distributions, then an invariable plane defined on orbits alone would be truly invariable and would constitute an inertial frame of reference. But almost all are not, allowing the transfer of a very small amount of momenta from axial rotations to orbital revolutions due to tidal friction and to bodies being non-spherical. This causes a change in the magnitude of the orbital angular momentum, as well as a change in its direction (precession) because the rotational axes are not parallel to the orbital axes
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Invariable plane Nevertheless, these changes are exceedingly small compared to the total angular momenta of the system (which is conserved despite these effects, ignoring the even much tinier amounts of angular momentum ejected in material and gravitational waves leaving the Solar System, and the extremely tiny torques exerted on the Solar System by other stars, etc.), and for almost all purposes the plane defined on orbits alone can be considered invariable when working in Newtonian dynamics.
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Patrick J. Keeling Patrick John Keeling is a biologist and professor in the Department of Botany at the University of British Columbia. His research investigates the phylogeny, genomics and molecular evolution of protists and his work has led to numerous advances in assembling the eukaryotic tree of life. He has also identified several cases of horizontal gene transfer.
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Natural history of Trinidad and Tobago Trinidad and Tobago are continental islands with a geologically very recent history of direct land bridge connection to South America. As a result, unlike most of the Caribbean Islands, Trinidad and Tobago supports a primarily South American flora and fauna and has greater diversity of plant and animal species than the Antilles. However, rates of endemism are lower than in the rest of the Caribbean because there has been less time for genetic isolation from mainland populations because of the history of land bridge connections and hence fewer opportunities for speciation, and so a greater proportion of the species in Trinidad and Tobago are also found on the South American mainland. Trinidad is nearer to mainland South America and has been directly connected to the mainland via land bridges more often and for longer periods than Tobago. This, as well as Trinidad's larger size and more varied topography and hydrology compared to that of Tobago allow greater species and ecosystem diversity on the former compared to that on the later of the islands. The standard description of plant communities follows John Beard's work (Beard, 1946). He classified natural vegetation in a hierarchical fashion on the basis of the physiognomy of the dominant trees. Trinidad and Tobago is home to about 99 species of terrestrial mammals
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Natural history of Trinidad and Tobago About 65 of the mammalian species in the islands are bats (including cave roosting, tree and cavity roosting bats and even foliage-tent-making bats; all with widely differing diets from nectar and fruit, to insects, small vertebrates such as fish, frogs, small birds and rodents and even those that consume vertebrate blood). The next most diverse group of mammals in the islands are the rodents. The largest of these rodents are the lowland paca, the Brazilian porcupine, and the red-rumped agouti (of these, only the agouti remains extant on Tobago). One squirrel (the red-tailed squirrel) and several native rats and mice are also part of the rodent fauna. A few species of opossums including the common opossum may be found on both islands. Two anteaters, the southern tamandua and the silky anteater are found in Trinidad (but not in Tobago). The nine-banded armadillo can still be found on both islands. Native mammals of the order Carnivora include the ocelot, the tayra, the Neotropical river otter and the crab-eating raccoon (all four being found on Trinidad, with only the raccoon still extant on Tobago). The small Asian mongoose was introduced to Trinidad (but not to Tobago) during the later part of the 19th century and is now naturalized. The two native hoofed-mammals still found in Trinidad include the red brocket deer and the collared peccary (in Tobago, the deer is thought to be extirpated and the peccary is now fairly rare)
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Natural history of Trinidad and Tobago The red howler monkey and the white-fronted capuchin are Trinidad's two native non-human primate species. The tufted capuchin monkey was introduced to the northwestern peninsula of Trinidad during World War II and is now naturalized there. No monkeys remain extant on Tobago. For comments on native aquatic mammals (namely manatees) and native marine mammals (whales and dolphins), see the appropriate sections below. 472 species of birds have been recorded in Trinidad and Tobago (and the list of recorded species seems be still slowly increasing from year to year). There are few places in the world where so many birds can be seen in such a small area (with probably one of the highest bird species to area ratios of any country). Many of the species are very rare or are of particular interest. They range from the many species of hummingbirds to the primitive cave-dwelling oilbird (that uses sonar to fly in the dark) to the spectacularly beautiful scarlet ibis. The islands are within a few miles of Venezuela, and the species are therefore typical of tropical South America. However, the variety (although quite exceptional for such a small geographic area) is somewhat impoverished compared to the mainland, as would be expected with small islands. The resident breeding birds are augmented in the northern winter by migrants from North America. Tobago has only about half the number of bird species of Trinidad, but about 22 birds have been reported only from Tobago, including 12 breeding species
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Natural history of Trinidad and Tobago The country hosts a few endemic avian subspecies and two endemic species (the critically endangered Trinidad Piping Guan found only in Trinidad, and the Trinidad Motmot found on both islands, but more common in Tobago). The best sources of information regarding the recorded amphibians and reptiles of Trinidad and Tobago to date are Murphy (1997) and Boos (2001). Since those publications, a few new records as well as several taxonomic changes have been made (Murphy and Downie, 2012). The herpetofaunal list is at present in a state of flux, as taxonomy and systematics continue to be revised. To date (July 2014), the generally accepted recorded numbers of species of the various major groups of amphibians and reptiles are as follows: Frogs and toads (Anura): 37 species in total for the country. (33 recorded from Trinidad and 15 recorded on Tobago, with 4 of those from Tobago not known from Trinidad, and 2 of those from Trinidad known from just one specimen each. There is one introduced species, known on both Trinidad and Tobago). Caecilians (Gymnophonia): 1 species in total from Trinidad only. (Recorded from only 1 specimen). Turtles, terrapins and tortoises (Chelonii): 14 species recorded in total for the country (All 14 recorded for Trinidad, and possibly 6 recorded for Tobago. Four species are marine, with at least 4 being noted off Tobago, with at least 3 of those regularly breeding on both islands. Four are confirmed native terrestrial system species of Trinidad (1 of these is possibly a waif on Tobago)
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Natural history of Trinidad and Tobago One is possibly a long introduced species on both islands that is still present in the wild in some areas of Trinidad, but unconfirmed in the wild in Tobago. One is very recently introduced in Trinidad from North America and it is unconfirmed if it is breeding in the wild. Three are possibly occasional waifs to Trinidad from the nearby continent with no verified local breeding populations). Crocodiles and alligators (Crocodylia): 4 species recorded in total for the country (two are known to be native and breeding on Trinidad, with one of those breeding in Tobago, while the other 2 were occasionally historically recorded as waifs). Legless lizards (Amphisbaenia): 2 species from Trinidad only. Lizards (Sauria): 31 confirmed records for the country in total (2 of those not yet 'officially' documented). (Of the 31 confirmed records, 27 are from Trinidad, with at least 7 relatively recent historical introductions with 1 of these subsequently assumed to have been extirpated. Nineteen are from Tobago, with at least 3 relatively recent historical introductions there. Four of those from Tobago are not found on Trinidad. In addition to the 31 confirmed records, there are at least 3 species records that are dubious). Snakes (Serpentes): 50 accepted records for the country in total (1 of these not yet 'officially' documented). (Of these 50 records, 45 are from Trinidad and 22 are from Tobago, with 5 of those from Tobago not being recorded from Trinidad
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Natural history of Trinidad and Tobago Of the 50 records for the country, 7 species are known from just 1 or 2 records. In addition to the 50 generally accepted confirmed records, there are at least 2 dubious records). A number of frogs and toads inhabit the islands, including the well known huge marine or cane toad ("Rhinella marina") locally known as the crapaud (pronounced crah-poh) on both islands, and the tiny colourful rare endemic species known as the El Tucuche golden tree frog ("Phytotriades auratus") found only in the giant epiphitic bromeliads at the mist-shrouded summits of Trinidad's two highest peaks. The strangest of all Trinidad's frogs is the highly aquatic Suriname toad or pipa toad ("Pipa pipa"), the tadpoles of which develop in the skin tissue of the mother's back, before bursting out and emerging as miniature replicas of the adult frogs. The giant tree frog ("Hypsiboas boans") known locally as the giant flying frog is commonly heard calling after dusk from the vegetation along forest-lined streams in Trinidad. The two frog species of the genus "Mannophryne" found diurnally active in forests along fast flowing mountain streams (one of which is endemic to Trinidad and the other endemic to Tobago) both demonstrate a degree of parental care as the tadpoles are transported on the backs of the adult males before a suitable fairly predator-free body of water is found where they may be left to develop
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Natural history of Trinidad and Tobago The relatively recently introduced Grenadian 'tink' frog ("Eleutherodactylus johnstonei") can be heard at night in loud metallic 'tinking' choruses in urban residential neighbourhood yards and parks from Diego Martin to Sangre Grande in Trinidad, and more recently in southwestern Tobago. The tungara frog or locally called the "pung-la-la" ("Engystomops pustulosus") is commonly heard at night calling from wet grassy ditches in open habitats in both urban and rural areas on both islands and their foam nests are found even in small road and trail side puddles during the rainy season. The southwestern peninsula of Trinidad is home to a rather diverse community of frogs, with at least one ("Leptodactylus nesiotus") being known only from that area (an endemic). Trinidad may also be home to a caecilian ("Typhlonectes" species) (a legless highly aquatic amphibian with an eel-like body that is rarely observed due to its habitat specifications) although only one specimen has ever been scientifically documented from Trinidad. Terrapins, tortoises and marine turtles make their homes on and around these islands. The giant leatherback sea turtle ("Dermochelys coriacea"), the hawksbill turtle ("Eretmochelys imbricata"), the loggerhead turtle ("Caretta caretta"), the olive ridley turtle ("Lepidochelys olivacea") and the green sea turtle ("Chelonia mydas") are marine species that either nest on the islands' beaches or frequent their coastal waters
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Natural history of Trinidad and Tobago The land dwelling yellow-footed tortoise ("Geochelone denticulata") or Morrocoy as it is locally known is threatened by high levels of poaching in Trinidad. The odd mata-mata turtle ("Chelus fimbriata") is known as a waif (and is possibly a rare inhabitant) of the Nariva Swamp and other southern and eastern coastal river systems in Trinidad. The wood-turtle locally known as the Galap ("Rhinoclemmys punctularia") is found in and near rivers, streams and swamps in Trinidad, and has appeared on occasion as a waif on Tobago. All the marine turtle species are threatened by illegal hunting activity and as the bycatch of gillnet fishing. Nevertheless there has been great success achieved by measures taken to educate the public and ensure species conservation since the 1970s. Beaches on Trinidad's northern and eastern coasts are noted among the top 3 internationally most important nesting grounds for leatherback sea turtles and a few community run conservation organizations help to maintain the nesting habitats, deter poaching and to bring sustainable revenue generated via ecotourism into their communities. The spectacled caiman ("Caiman crocodilus") which may grow up to a maximum of about in length, but are usually somewhat smaller are to be found throughout both islands in slow moving freshwater (including reservoirs) or brackish water along the coasts. They are shy creatures and pose no real threat to humans unless intentionally provoked or approached while nesting
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Natural history of Trinidad and Tobago It is generally considered that the few records of both the American crocodile ("Crocodylus acutus") as well as the Orinoco crocodile ("Crocodylus intermedius") in the waters and on the coasts of Trinidad and Tobago were, for the most part, waifs from mainland South America. There are two species of legless lizards "Amphisbaena alba" and "Amphisbaena fuliginosa" known as 'two headed' snakes on Trinidad. They spend much of their lives burrowing in the soil in forest or forest-edge areas and are often associated with the nests of leaf-cutter ants "Atta", which form part of their diet. There are a number of lizards ranging in size from just over an inch or two in length to the huge long green iguana ("Iguana iguana"). The so-called luminous lizard ("Riama shrevei") makes its home in primary lower montane and montane forest at the mouths of caves and cool stream banks on the high peaks, ridges and high valleys of the Northern Range of Trinidad and is found nowhere else on earth. Found in forest, forest edge and savanna habitats, the large tegu ("Tupinambis teguixin") or matte/salipenta as it is locally called and the green iguana (still fairly common, even in some sub-urban areas) are considered delicacies on both Trinidad and Tobago. A number of anole species ("Anolis") may be easily observed, even in suburban areas. Only "Anolis chrysolepis" is a Trinidad native, with all other anoles being relatively recently or historically introduced
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Natural history of Trinidad and Tobago Other common lizards include macro-teiids (or whip-tailed lizards) such as the "Ameiva atrigularis" (locally called the zandolie or ground lizard and common even in suburban gardens) and "Cnemidophorus lemniscatus" (most readily seen along some coastal areas of southwestern Tobago and on Trinidad's east and south coasts and on the islands of Chacachacare, Huevos, Little Tobago and Goat Island). Nocturnally active geckos of the genera "Thecadactylus" and "Hemidactylus" are common in old and rural buildings on both islands and are commonly referred to as mabouias and wood slaves respectively. There are a number of small colourful diurnal geckos of the genus "Gonatodes" present. One of them, "Gonatodes ocellatus" is endemic to forests and edge habitats of northeastern Tobago while another, "Gonatodes vittatus" or the streak lizard as it is locally known, is very common and can be seen in most suburban and even urban backyards in Trinidad (and is probably relatively recently introduced to some parts Tobago associated with human occupation). The tiny Mole's gecko "Sphaerodactylus molei" is found on both islands and is among the smallest of lizards in the world. Included among the country's snake fauna are some of the very smallest in the world (the fossorial thread snakes in the genus "Epictia" and other blind snakes), to the very largest of snakes in the world (the green anaconda)
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Natural history of Trinidad and Tobago Anacondas (locally called the huille) have been historically found around streams, rivers and swamps in southern and eastern Trinidad, and recently also in the Caroni River drainage system. They have not been reported from Tobago. Three other boas, namely "Boa constrictor" (locally called the macajuel), "Corallus ruschenbergerii" (a tree boa locally called the cascabel dormilon) and "Epicrates maurus" (a rainbow boa) are found in forest and forest edge habitats throughout both islands (with the last even being common in some urban areas). Several harmless snakes in the subfamilies Colubrinae and Dipsadinae are found throughout the islands. Some of the larger examples of the diurnal Colubrinae include "Spilotes pullatus" (locally called the tigre in Trinidad and the black snake in Tobago) found in forest and forest edge habitats, and the rarer more forest dwelling "Drymarchon corais" (or yellow-tailed cribo) can be found on both islands. Smaller well known members of the subfamily include the machete couesse ("Mastigodryas boddaerti" on Trinidad, and "Mastigodryas dunni" endemic to Tobago) and the horsewhip ("Oxybelis aeneus") and are common in forest and forest edge habitats, even in some suburban areas of both islands. Among the Colubrinae, the loras "Leptophis stimsoni" and "Leptophis haileyi" are endemics to Trinidad's Northern Range and Tobago's Main Ridge respectively
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Natural history of Trinidad and Tobago Many of the members of the subfamily Dipsadinae are typically nocturnal and some of the more commonly observed species present even in suburban areas on both islands are the false mapipire ("Leptodeira annulata ashmeadi") and the slug-eating snake ("Sibon nebulata"). Other interesting Dipsadinae include the water mapipire ("Helicops angulatus") a habitat specialist of freshwater and brackish water systems of lowland Trinidad, the mainly diurnal beh belle chemin ("Erythrolamprus melanotus nesos") of forest and edge habitats on both islands and the rare crepuscular red snake ("Erythrolamprus ocellatus") endemic to the forest and edge habitats of northeastern Tobago. There are no dangerous venomous snakes on Tobago. There are only four dangerous venomous snakes on Trinidad. These include two vipers, and two coral snakes. The vipers (the true mapipires) are the mapipire balsain ("Bothrops" cf. "atrox") and the mapipire zanana ("Lachesis muta muta"). The former is fairly common in primary and secondary forested areas of Trinidad (particularly so in the Northern Range), and the later is a very rarely encountered primary rainforest specialist in Trinidad. The two coral snakes are the small coral snake ("Micrurus circinalis", and the large coral snake ("Micrurus lemniscatus diutius"), both associated with forested areas, and the later sometimes being associated with swampy habitats in Trinidad. Fatal venomous snake bite accidents in Trinidad are fairly uncommon
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Natural history of Trinidad and Tobago It is unfortunate to note that although all snakes (with the exception of the potentially dangerous vipers and corals) are protected by law in Trinidad and Tobago, the human population at large is not generally tolerant of snakes, and even harmless snakes found near human dwellings, farms and gardens are often killed on sight. More public awareness is needed to dispel misconceptions about snakes as well as to sensitize the population to the ecological importance of snakes. Trinidad and Tobago are extremely rich in neotropical invertebrate fauna. Several hundred species of butterflies, including the brilliant blue emperor butterfly ("Morpho peleides"), and beetles are to be found on the islands, many in the tropical forests. Barcant (1970) lists 617 species of butterfly for the two islands of which 123 occur on Tobago. The leaf cutter ant ("Atta") is easily observed, even in sub-urban environments. Soldier ants may be observed in forested areas. The largest specimens of centipedes (genus "Scolopendra")(over long) may be found particularly in the drier forests of the Northwestern Peninsular of Trinidad (the Chaguaramas Peninsular) as well as the nearby tiny off shore islands. A few species of large tarantulas may be found in forested areas and even in houses at the forest edge. The arthropod life of Trinidad and Tobago has not been well studied and it is an entomologist's paradise waiting to be discovered, with many species remaining undocumented
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Natural history of Trinidad and Tobago There are approximately 70 species of land snails ranging in size from the giant South American land snail ("Megalobulimus oblongus") to the tiny Gastrocopta snails. Many species of crustaceans (terrestrial, freshwater and marine) are among the other invertebrates that may be easily observed in Trinidad and Tobago. There are nine species of scorpions in Trinidad and Tobago including the medically important "Tityus trinitatis". There are a number of wetland habitats on both Trinidad and Tobago that foster vital aquatic ecosystems. The Bon Accord Lagoon on Tobago is a vital mangrove habitat and home to a population of spectacled caimans as well as a number of wetland bird species. The Caroni Swamp on the west coast of Trinidad has a fairly high level of salinity (compared to other major wetlands on the island) and is an important breeding and feeding habitat for several bird species (including magnificent flocks of scarlet ibis (one of the National Birds)) and several marine fishes and invertebrates. The Nariva Swamp of the east coast is the largest freshwater swamp on Trinidad and has a Ramsar Convention status of wetland of international importance. It and its associated river system of canals and rivers is home to a vast array of aquatic life, including a very small population of the highly endangered West Indian manatee, the green anaconda, the spectacled caiman, the mata mata turtle and the common Suriname toad. The plant community in the swamp include various mangroves, moriche palms and bloodwood trees
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Natural history of Trinidad and Tobago There are many small rivers and streams throughout the islands. Over 40 species of freshwater fish have been recorded in Trinidad and Tobago. The world-famous guppy is a common native fish; particularly so in the mountain streams of Trinidad, where it has served as a model organism for several important ecological and evolutionary studies. Trinidad's western and southern coastal waters are highly influenced by the outflow of freshwater from the adjacent Orinoco River of Venezuela which is less than away from Trinidad at the closest point. As such, the waters here are fairly low in salinity and high in sediment/nutrient content and relatively shallow. These facts coupled with the highly sheltered nature of the Gulf of Paria and the Columbus Channel respectively, create ideal breeding/spawning grounds for many marine fishes and invertebrates, including shrimp. Various 'sporting' fish are present in the waters of both islands and include huge grouper, marlin, barracuda and dolphin-fish. Fish popularly caught and eaten include carite, kingfish and red snapper. As mentioned in the section above on the reptilian fauna of Trinidad and Tobago, a number of species of marine turtles including the leatherback turtle, hawksbill turtle, loggerhead turtle, olive ridley turtle and green sea turtle frequent the waters around and/or nest on some of the beaches of both islands
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Natural history of Trinidad and Tobago Whales and dolphins were far more common to Trinidad and Tobago's waters in earlier times, but the very rigorous whaling industry of the 19th century decimated the population of whales in the Gulf of Paria (called 'Golfo de Balena' or Gulf of Whales by Christopher Columbus). Today, dolphins may still be regularly observed, particularly off the shore of the northwestern Chaguaramas peninsula. Pilot whales have been observed to beach themselves on a few occasions during the 1990s and a small pod of killer whales were caught in a fisherman's net during the 1980s. "See also: List of mammals of Trinidad and Tobago" Whale sharks (the largest of all fishes) have been observed around the oil rigs in the southern part of the Gulf of Paria. Hammerhead sharks are commonly caught by fishermen and shark flesh is unfortunately considered a delicacy among the human population of both islands. The waters of Tobago are less affected by the outflow of fresh water from the Orinoco and as such are far more saline and clearer than that of Trinidad. A number of coral reefs are thus able to exist around Tobago, the most famous being the Buccoo Reef. Tobago's reefs are reputedly home to the largest examples of brain coral. Also present are huge and gentle manta rays, impressive moray eels, parrot fish, angel fish and a host of other colourful tropical coral reef species.
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Rheid In geology, a rheid is a substance whose temperature is below the melting point and whose deformation by viscous flow during the time of observation is at least three orders of magnitude (1,000×) greater than the elastic deformation under the given conditions. A material is a rheid by virtue of the time of observation. The term, coined by S. Warren Carey in 1953, has the same Greek root as rheology, the science of viscoelasticity and nonlinear flow. Almost any type of rock can behave as a rheid under appropriate conditions of temperature and pressure. For example, the Earth's mantle undergoes convection over long time-scales. As the mantle supports the propagation of shear waves, it may be deduced that it is a solid and, therefore, behaving as a rheid when it undergoes said convection. Granite has a measured viscosity at standard temperature and pressure of about 4.5×10 Pa·s so it should be considered a rheid. Halite, the mineral form of salt, is a geological material that behaves as a rheid over relatively short time-periods. As salt is buried by other types of sediments, it will often flow laterally towards regions of less-confining stress. Through this mechanism, salt domes and other structures may form. In some areas, such as the Gulf of Mexico, these structures often serve as traps for petroleum and natural gas.
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Static spacetime In general relativity, a spacetime is said to be static if it does not change over time and is also irrotational. It is a special case of a stationary spacetime: the geometry of a stationary spacetime does not change in time; however, it can rotate. Thus, the Kerr solution provides an example of a stationary spacetime that is not static; the non-rotating Schwarzschild solution is an example that is static. Formally, a spacetime is static if it admits a global, non-vanishing, timelike Killing vector field formula_1 which is irrotational, "i.e.", whose orthogonal distribution is involutive. (Note that the leaves of the associated foliation are necessarily space-like hypersurfaces.) Thus, a static spacetime is a stationary spacetime satisfying this additional integrability condition. These spacetimes form one of the simplest classes of Lorentzian manifolds. Locally, every static spacetime looks like a standard static spacetime which is a Lorentzian warped product "R" formula_2 "S" with a metric of the form where "R" is the real line, formula_4 is a (positive definite) metric and formula_5 is a positive function on the Riemannian manifold "S". In such a local coordinate representation the Killing field formula_1 may be identified with formula_7 and "S", the manifold of formula_1-"trajectories", may be regarded as the instantaneous 3-space of stationary observers
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Static spacetime If formula_9 is the square of the norm of the Killing vector field, formula_10, both formula_9 and formula_12 are independent of time (in fact formula_13). It is from the latter fact that a static spacetime obtains its name, as the geometry of the space-like slice "S" does not change over time. In general, "almost all" spacetimes will not be static. Some explicit examples include:
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Émile Blanchard Charles (6 March 1819 – 11 February 1900) was a French zoologist and entomologist. Blanchard was born in Paris. His father was an artist and naturalist and Émile began natural history very early in life. When he was 14 years old, Jean Victoire Audouin (1797—1841), allowed him access to the laboratory of the Muséum national d'Histoire naturelle. In 1838, he became a technician or "préparateu"r in this then, as now, famous institution. In 1841, he became assistant-naturalist. He accompanied Henri Milne-Edwards (1800—1885) and Jean Louis Armand de Quatrefages de Breau (1810—1892) to Sicily on a marine zoology expedition. He published, in 1845 a "Histoire des insectes", or History of the insects and, in 1854—1856 "Zoologie agricole" or Agricultural Zoology. This last work is remarkable: it presents in a precise way the harmful or pest species and the damage they cause to various crop plants. This work was illustrated by his father. Blanchard was critical of Darwinism. He argued that Charles Darwin's pigeon studies were unscientific and that his ideas about evolution were false and unoriginal. In 1870, Blanchard and Charles-Philippe Robin opposed the election of Darwin as a corresponding member of the French Academy of Sciences. He published an atlas of the anatomy of the vertebrates which appeared between 1852 and 1864
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Émile Blanchard This publication raised his hopes to obtain the chair of reptiles and fish at the Natural History Museum left vacant by the death of Auguste Duméril (1812—1870) but it was finally Léon Vaillant (1834—1914) who was selected. However, in 1862, he was given the chair of natural history of Crustacea, Arachnida and Insects. He left this in 1894 following his infirmity. He was elected, in 1862 into the Academy of Science. He began to lose his sight after 1860 and became blind in 1890. He died in Paris.
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Chemical biology is a scientific discipline spanning the fields of chemistry and biology. The discipline involves the application of chemical techniques, analysis, and often small molecules produced through synthetic chemistry, to the study and manipulation of biological systems. In contrast to biochemistry, which involves the study of the chemistry of biomolecules and regulation of biochemical pathways within and between cells, chemical biology deals with chemistry "applied to" biology (synthesis of biomolecules, simulation of biological systems etc.). Some forms of chemical biology attempt to answer biological questions by directly probing living systems at the chemical level. In contrast to research using biochemistry, genetics, or molecular biology, where mutagenesis can provide a new version of the organism, cell, or biomolecule of interest, chemical biology probes systems "in vitro" and "in vivo" with small molecules that have been designed for a specific purpose or identified on the basis of biochemical or cell-based screening (see chemical genetics). is one of several interdisciplinary sciences that tend to differ from older, reductionist fields and whose goals are to achieve a description of scientific holism. has scientific, historical and philosophical roots in medicinal chemistry, supramolecular chemistry, bioorganic chemistry, pharmacology, genetics, biochemistry, and metabolic engineering
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Chemical biology Chemical biologists work to improve proteomics through the development of enrichment strategies, chemical affinity tags, and new probes. Samples for proteomics often contain many peptide sequences and the sequence of interest may be highly represented or of low abundance, which creates a barrier for their detection. methods can reduce sample complexity by selective enrichment using affinity chromatography. This involves targeting a peptide with a distinguishing feature like a biotin label or a post translational modification. Methods have been developed that include the use of antibodies, lectins to capture glycoproteins, and immobilized metal ions to capture phosphorylated peptides and enzyme substrates to capture select enzymes. To investigate enzymatic activity as opposed to total protein, activity-based reagents have been developed to label the enzymatically active form of proteins (see Activity-based proteomics). For example, serine hydrolase- and cysteine protease-inhibitors have been converted to suicide inhibitors. This strategy enhances the ability to selectively analyze low abundance constituents through direct targeting. Enzyme activity can also be monitored through converted substrate. Identification of enzyme substrates is a problem of significant difficulty in proteomics and is vital to the understanding of signal transduction pathways in cells
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Chemical biology A method that has been developed uses "analog-sensitive" kinases to label substrates using an unnatural ATP analog, facilitating visualization and identification through a unique handle. While DNA, RNA and proteins are all encoded at the genetic level, glycans (sugar polymers) are not encoded directly from the genome and fewer tools are available for their study. Glycobiology is therefore an area of active research for chemical biologists. For example, cells can be supplied with synthetic variants of natural sugars to probe their function. Carolyn Bertozzi's research group has developed methods for site-specifically reacting molecules at the surface of cells via synthetic sugars. Chemical biologists used automated synthesis of diverse small molecule libraries in order to perform high-throughput analysis of biological processes. Such experiments may lead to discovery of small molecules with antibiotic or chemotherapeutic properties. These combinatorial chemistry approaches are identical to those employed in the discipline of pharmacology. Many research programs are also focused on employing natural biomolecules to perform biological tasks or to support a new chemical method. In this regard, chemical biology researchers have shown that DNA can serve as a template for synthetic chemistry, self-assembling proteins can serve as a structural scaffold for new materials, and RNA can be evolved "in vitro" to produce new catalytic function
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Chemical biology Additionally, heterobifunctional (two-sided) synthetic small molecules such as dimerizers or PROTACs bring two proteins together inside cells, which can synthetically induce important new biological functions such as targeted protein degradation. Chemical synthesis of proteins is a valuable tool in chemical biology as it allows for the introduction of non-natural amino acids as well as residue specific incorporation of "posttranslational modifications" such as phosphorylation, glycosylation, acetylation, and even ubiquitination. These capabilities are valuable for chemical biologists as non-natural amino acids can be used to probe and alter the functionality of proteins, while post translational modifications are widely known to regulate the structure and activity of proteins. Although strictly biological techniques have been developed to achieve these ends, the chemical synthesis of peptides often has a lower technical and practical barrier to obtaining small amounts of the desired protein. In order to make protein-sized polypeptide chains via the small peptide fragments made by synthesis, chemical biologists use the process of native chemical ligation. Native chemical ligation involves the coupling of a C-terminal thioester and an N-terminal cysteine residue, ultimately resulting in formation of a "native" amide bond
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Chemical biology Other strategies that have been used for the ligation of peptide fragments using the acyl transfer chemistry first introduced with native chemical ligation include expressed protein ligation, sulfurization/desulfurization techniques, and use of removable thiol auxiliaries. Expressed protein ligation allows for the biotechnological installation of a C-terminal thioester using inteins, thereby allowing the appendage of a synthetic N-terminal peptide to the recombinantly-produced C-terminal portion. Both sulfurization/desulfurization techniques and the use of removable thiol auxiliaries involve the installation of a synthetic thiol moiety to carry out the standard native chemical ligation chemistry, followed by removal of the auxiliary/thiol. A primary goal of protein engineering is the design of novel peptides or proteins with a desired structure and chemical activity. Because our knowledge of the relationship between primary sequence, structure, and function of proteins is limited, rational design of new proteins with engineered activities is extremely challenging. In directed evolution, repeated cycles of genetic diversification followed by a screening or selection process, can be used to mimic natural selection in the laboratory to design new proteins with a desired activity. Several methods exist for creating large libraries of sequence variants. Among the most widely used are subjecting DNA to UV radiation or chemical mutagens, error-prone PCR, degenerate codons, or recombination
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Chemical biology Once a large library of variants is created, selection or screening techniques are used to find mutants with a desired attribute. Common selection/screening techniques include FACS, mRNA display, phage display, and "in vitro" compartmentalization. Once useful variants are found, their DNA sequence is amplified and subjected to further rounds of diversification and selection. The 2018 Nobel Prize in Chemistry was awarded to Frances Arnold, George Smith, and Gregory Winter for their pioneering work in directed evolution. Successful labeling of a molecule of interest requires specific functionalization of that molecule to react chemospecifically with an optical probe. For a labeling experiment to be considered robust, that functionalization must minimally perturb the system. Unfortunately, these requirements are often hard to meet. Many of the reactions normally available to organic chemists in the laboratory are unavailable in living systems. Water- and redox- sensitive reactions would not proceed, reagents prone to nucleophilic attack would offer no chemospecificity, and any reactions with large kinetic barriers would not find enough energy in the relatively low-heat environment of a living cell. Thus, chemists have recently developed a panel of bioorthogonal chemistry that proceed chemospecifically, despite the milieu of distracting reactive materials "in vivo"
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Chemical biology The coupling of an probe to a molecule of interest must occur within a reasonably short time frame; therefore, the kinetics of the coupling reaction should be highly favorable. Click chemistry is well suited to fill this niche, since click reactions are rapid, spontaneous, selective, and high-yielding. Unfortunately, the most famous "click reaction," a [3+2] cycloaddition between an azide and an acyclic alkyne, is copper-catalyzed, posing a serious problem for use "in vivo" due to copper's toxicity. To bypass the necessity for a catalyst, Carolyn R. Bertozzi's lab introduced inherent strain into the alkyne species by using a cyclic alkyne. In particular, cyclooctyne reacts with azido-molecules with distinctive vigor. The most common method of installing bioorthogonal reactivity into a target biomolecule is through metabolic labeling. Cells are immersed in a medium where access to nutrients is limited to synthetically modified analogues of standard fuels such as sugars. As a consequence, these altered biomolecules are incorporated into the cells in the same manner as the unmodified metabolites. A probe is then incorporated into the system to image the fate of the altered biomolecules. Other methods of functionalization include enzymatically inserting azides into proteins, and synthesizing phospholipids conjugated to cyclooctynes
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Chemical biology The advances in modern sequencing technologies in the late 1990s allowed scientists to investigate DNA of communities of organisms in their natural environments ("eDNA"), without culturing individual species in the lab. This metagenomic approach enabled scientists to study a wide selection of organisms that were previously not characterized due in part to an incompetent growth condition. Sources of eDNA include soils, ocean, subsurface, hot springs, hydrothermal vents, polar ice caps, hypersaline habitats, and extreme pH environments. Of the many applications of metagenomics, researchers such as Jo Handelsman, Jon Clardy, and Robert M. Goodman, explored metagenomic approaches toward the discovery of biologically active molecules such as antibiotics. Functional or homology screening strategies have been used to identify genes that produce small bioactive molecules. Functional metagenomic studies are designed to search for specific phenotypes that are associated with molecules with specific characteristics. Homology metagenomic studies, on the other hand, are designed to examine genes to identify conserved sequences that are previously associated with the expression of biologically active molecules. Functional metagenomic studies enable the discovery of novel genes that encode biologically active molecules
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Chemical biology These assays include top agar overlay assays where antibiotics generate zones of growth inhibition against test microbes, and pH assays that can screen for pH change due to newly synthesized molecules using pH indicator on an agar plate. Substrate-induced gene expression screening (SIGEX), a method to screen for the expression of genes that are induced by chemical compounds, has also been used to search for genes with specific functions. Homology-based metagenomic studies have led to a fast discovery of genes that have homologous sequences as the previously known genes that are responsible for the biosynthesis of biologically active molecules. As soon as the genes are sequenced, scientists can compare thousands of bacterial genomes simultaneously. The advantage over functional metagenomic assays is that homology metagenomic studies do not require a host organism system to express the metagenomes, thus this method can potentially save the time spent on analyzing nonfunctional genomes. These also led to the discovery of several novel proteins and small molecules. In addition, an "in silico" examination from the Global Ocean Metagenomic Survey found 20 new lantibiotic cyclases. Posttranslational modification of proteins with phosphate groups by kinases is a key regulatory step throughout all biological systems. Phosphorylation events, either phosphorylation by protein kinases or dephosphorylation by phosphatases, result in protein activation or deactivation
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Chemical biology These events have an impact on the regulation of physiological pathways, which makes the ability to dissect and study these pathways integral to understanding the details of cellular processes. There exist a number of challenges—namely the sheer size of the phosphoproteome, the fleeting nature of phosphorylation events and related physical limitations of classical biological and biochemical techniques—that have limited the advancement of knowledge in this area. Through the use of small molecule modulators of protein kinases, chemical biologists have gained a better understanding of the effects of protein phosphorylation. For example, nonselective and selective kinase inhibitors, such as a class of pyridinylimidazole compounds are potent inhibitors useful in the dissection of MAP kinase signaling pathways. These pyridinylimidazole compounds function by targeting the ATP binding pocket. Although this approach, as well as related approaches, with slight modifications, has proven effective in a number of cases, these compounds lack adequate specificity for more general applications. Another class of compounds, mechanism-based inhibitors, combines knowledge of the kinase enzymology with previously utilized inhibition motifs. For example, a "bisubstrate analog" inhibits kinase action by binding both the conserved ATP binding pocket and a protein/peptide recognition site on the specific kinase. Research groups also utilized ATP analogs as chemical probes to study kinases and identify their substrates
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Chemical biology The development of novel chemical means of incorporating phosphomimetic amino acids into proteins has provided important insight into the effects of phosphorylation events. Phosphorylation events have typically been studied by mutating an identified phosphorylation site (serine, threonine or tyrosine) to an amino acid, such as alanine, that cannot be phosphorylated. However, these techniques come with limitations and chemical biologists have developed improved ways of investigating protein phosphorylation. By installing phospho-serine, phospho-threonine or analogous phosphonate mimics into native proteins, researchers are able to perform in vivo studies to investigate the effects of phosphorylation by extending the amount of time a phosphorylation event occurs while minimizing the often-unfavorable effects of mutations. Expressed protein ligation, has proven to be successful techniques for synthetically producing proteins that contain phosphomimetic molecules at either terminus. In addition, researchers have used unnatural amino acid mutagenesis at targeted sites within a peptide sequence. Advances in chemical biology have also improved upon classical techniques of imaging kinase action. For example, the development of peptide biosensors—peptides containing incorporated fluorophores improved temporal resolution of in vitro binding assays. One of the most useful techniques to study kinase action is Fluorescence Resonance Energy Transfer|FRET
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Chemical biology To utilize FRET for phosphorylation studies, fluorescent proteins are coupled to both a phosphoamino acid binding domain and a peptide that can by phosphorylated. Upon phosphorylation or dephosphorylation of a substrate peptide, a conformational change occurs that results in a change in fluorescence. FRET has also been used in tandem with Fluorescence Lifetime Imaging Microscopy (FLIM) or fluorescently conjugated antibodies and flow cytometry to provide quantitative results with excellent temporal and spatial resolution. Chemical biologists often study the functions of biological macromolecules using fluorescence techniques. The advantage of fluorescence versus other techniques resides in its high sensitivity, non-invasiveness, safe detection, and ability to modulate the fluorescence signal. In recents years, the discovery of green fluorescent protein (GFP) by Roger Y. Tsien and others, hybrid systems and quantum dots have enabled assessing protein location and function more precisely. Three main types of fluorophores are used: small organic dyes, green fluorescent proteins, and quantum dots. Small organic dyes usually are less than 1 kDa, and have been modified to increase photostability and brightness, and reduce self-quenching. Quantum dots have very sharp wavelengths, high molar absorptivity and quantum yield. Both organic dyes and quantum dyes do not have the ability to recognize the protein of interest without the aid of antibodies, hence they must use immunolabeling
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Chemical biology Fluorescent proteins are genetically encoded and can be fused to your protein of interest. Another genetic tagging technique is the tetracysteine biarsenical system, which requires modification of the targeted sequence that includes four cysteines, which binds membrane-permeable biarsenical molecules, the green and the red dyes "FlAsH" and "ReAsH", with picomolar affinity. Both fluorescent proteins and biarsenical tetracysteine can be expressed in live cells, but present major limitations in ectopic expression and might cause a loss of function. Fluorescent techniques have been used assess a number of protein dynamics including protein tracking, conformational changes, protein–protein interactions, protein synthesis and turnover, and enzyme activity, among others. Three general approaches for measuring protein net redistribution and diffusion are single-particle tracking, correlation spectroscopy and photomarking methods. In single-particle tracking, the individual molecule must be both bright and sparse enough to be tracked from one video to the other. Correlation spectroscopy analyzes the intensity fluctuations resulting from migration of fluorescent objects into and out of a small volume at the focus of a laser. In photomarking, a fluorescent protein can be dequenched in a subcellular area with the use of intense local illumination and the fate of the marked molecule can be imaged directly. Michalet and coworkers used quantum dots for single-particle tracking using biotin-quantum dots in HeLa cells
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Chemical biology One of the best ways to detect conformational changes in proteins is to label the protein of interest with two fluorophores within close proximity. FRET will respond to internal conformational changes result from reorientation of one fluorophore with respect to the other. One can also use fluorescence to visualize enzyme activity, typically by using a quenched activity based proteomics (qABP). Covalent binding of a qABP to the active site of the targeted enzyme will provide direct evidence concerning if the enzyme is responsible for the signal upon release of the quencher and regain of fluorescence.
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Hydrogen analyzer A hydrogen analyzer is a device used to measure the hydrogen concentration in steels and alloys. It also has industrial applications for corrosion monitoring.
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Pericycle The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. Although it is composed of non-vascular parenchyma cells, it's still considered part of the vascular cylinder because it arises from the procambium as do the vascular tissues it surrounds. In eudicots, it also has the capacity to produce lateral roots. Branch roots arise from this primary meristem tissue. In plants undergoing secondary growth, the pericycle contributes to the vascular cambium often diverging into a cork cambium. In angiosperms certain molecules within the endodermis and the surrounding vasculature are sent to the pericycle which promotes the growth of the root meristems. The pericycle is located between the endodermis and phloem in plant roots. In dicot stems, it is situated around the ring of vascular bundles in the stele. In dicot roots, the pericycle strengthens the roots and provides protection for the vascular bundles. In dicot root, the vascular cambium is completely secondary in origin, and it originates from a portion of pericycle tissue. The pericycle regulates the formation of lateral roots by rapidly dividing near the xylem elements of the root. It has been known to often be confused with other parts of the plant. However, its unique ring structure allows it to be more easily identified. Past efforts to isolate such tissue have been successful. Monocot roots rarely branch, but can, and this branch will originate from the pericycle.
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History of Animals (, "Ton peri ta zoia historion", "Inquiries on Animals"; "History of Animals") is one of the major texts on biology by the ancient Greek philosopher Aristotle, who had studied at Plato's Academy in Athens. It was written in the fourth century BC; Aristotle died in 322 BC. Generally seen as a pioneering work of zoology, Aristotle frames his text by explaining that he is investigating the "what" (the existing facts about animals) prior to establishing the "why" (the causes of these characteristics). The book is thus an attempt to apply philosophy to part of the natural world. Throughout the work, Aristotle seeks to identify differences, both between individuals and between groups. A group is established when it is seen that all members have the same set of distinguishing features; for example, that all birds have feathers, wings, and beaks. This relationship between the birds and their features is recognized as a universal. The "History of Animals" contains many accurate eye-witness observations, in particular of the marine biology around the island of Lesbos, such as that the octopus had colour-changing abilities and a sperm-transferring tentacle, that the young of a dogfish grow inside their mother's body, or that the male of a river catfish guards the eggs after the female has left. Some of these were long considered fanciful before being rediscovered in the nineteenth century
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History of Animals Aristotle has been accused of making errors, but some are due to misinterpretation of his text, and others may have been based on genuine observation. He did however make somewhat uncritical use of evidence from other people, such as travellers and beekeepers. The "History of Animals" had a powerful influence on zoology for some two thousand years. It continued to be a primary source of knowledge until in the sixteenth century zoologists including Conrad Gessner, all influenced by Aristotle, wrote their own studies of the subject. Aristotle (384–322 BC) studied at Plato's Academy in Athens, remaining there for some 17 years. Like Plato, he sought universals in his philosophy, but unlike Plato he backed up his views with detailed observation, notably of the natural history of the island of Lesbos and the marine life in the island's lagoon at Pyrrha. This study made him the earliest natural historian whose written work survives. No similarly detailed work on zoology was attempted until the sixteenth century; accordingly Aristotle remained highly influential for some two thousand years. His writings on zoology form about a quarter of his surviving work. Aristotle's pupil Theophrastus later wrote a similar book on botany, "Enquiry into Plants". In the "History of Animals", Aristotle sets out to investigate the existing facts (Greek "hoti", what), prior to establishing their causes (Greek "dioti", why). The book is thus a defence of his method of investigating zoology
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History of Animals Aristotle investigates four types of differences between animals: differences in particular body parts (Books I to IV); differences in ways of life and types of activity (Books V, VI, VII and IX); and differences in specific characters (Book VIII). To illustrate the philosophical method, consider one grouping of many kinds of animal, 'birds': all members of this group possess the same distinguishing features—feathers, wings, beaks, and two bony legs. This is an instance of a universal: if something is a bird, it will have feathers and wings; if something has feathers and wings, that also implies it is a bird, so the reasoning here is bidirectional. On the other hand, some animals that have red blood have lungs; other red-blooded animals (such as fish) have gills. This implies, in Aristotle's reasoning, that if something has lungs, it has red blood; but Aristotle is careful not to imply that all red-blooded animals have lungs, so the reasoning here is not bidirectional. Book I The grouping of animals and the parts of the human body. Aristotle describes the parts that the human body is made of, such as the skull, brain, face, eyes, ears, nose, tongue, thorax, belly, heart, viscera, genitalia, and limbs. Book II The different parts of red-blooded animals. Aristotle writes about limbs, the teeth of dogs, horses, man, and elephant; the elephant's tongue; and of animals such as the apes, crocodile, chameleon, birds especially the wryneck, fishes and snakes
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History of Animals Book III The internal organs, including generative system, veins, sinews, bone etc. He moves on to the blood, bone marrow, milk including rennet and cheese, and semen. Book IV Animals without blood (invertebrates) – cephalopods, crustaceans, etc. In chapter 8, he describes the sense organs of animals. Chapter 10 considers sleep and whether it occurs in fish. Books V and VI Reproduction, spontaneous and sexual of marine invertebrates, birds, quadrupeds, snakes, fish, and terrestrial arthropods including ichneumon wasps, bees, ants, scorpions, spiders, and grasshoppers. Book VII Reproduction of man, including puberty, conception, pregnancy, lactation, the embryo, labour, milk, and diseases of infants. Book VIII The character and habits of animals, food, migration, health, animal diseases including bee parasites, and the influence of climate. Book IX Social behaviour in animals; signs of intelligence in animals such as sheep and birds. A Book X is included in some versions, dealing with the causes of barrenness in women, but is generally regarded as not being by Aristotle. In the preface to his translation, D'Arcy Wentworth Thompson calls it "spurious beyond question". The "History of Animals" contains a large number of eye-witness observations, in particular of marine biology, in sharp contrast to Plato's "symbolic zoology"
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History of Animals Aristotle's style and precision can be seen in the passage where he discusses the behaviour and anatomy of the cephalopods, mentioning the use of ink against predators, camouflage, and signalling. This is D'Arcy Thompson's translation: His observations were almost all accurate, according to the philosopher Anthony Preus, though Mario Vegetti argues that Aristotle sometimes let theory cloud observation. Some of Aristotle's observations were not taken seriously by science until they were independently rediscovered in the 19th century. For example, he recorded that male octopuses have a hectocotylus, a tentacle which stores sperm and which can transfer it into the female's body; sometimes it snaps off during mating. The account was dismissed as fanciful until the French naturalist Georges Cuvier described it in his 1817 "Le Règne Animal". Aristotle also noted that the young of the dogfish grow inside their mother's body attached by a cord to something like a placenta (a yolk sac). This was confirmed in 1842 by the German zoologist Johannes Peter Müller. Aristotle noted, too, that a river catfish which he called the "glanis" cares for its young, as the female leaves after giving birth; the male guards the eggs for forty or fifty days, chasing off small fish which threaten the eggs, and making a murmuring noise. The Swiss American zoologist Louis Agassiz found the account to be correct in 1890
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History of Animals Aristotle's methods of observation included dissection (Aristotle's lost companion work, "The Dissections", contained illustrations of these), so he observed animal anatomy directly, though his interpretations of the functions of the structures he observed were subject to error. Like other classical authors such as Pliny the Elder, Aristotle also gathered evidence from travellers and people with specialised knowledge, such as fishermen and beekeepers, without much attempt to corroborate what they said. The text contains some claims that appear to be errors. Aristotle asserted that the females of any species have a smaller number of teeth than the males. This apparently readily falsifiable claim could have been a genuine observation, if as Robert Mayhew suggests women at that time had a poorer diet than men; but the claim is not true of other species either. Thus, Philippa Lang argues, Aristotle may have been empirical, but he was quite laissez-faire about observation, "because [he] was not expecting nature to be misleading". In other cases, errors may have been wrongly attributed to Aristotle. Katrin Weigmann wrote "[Aristotle's] statement that flies have four legs was repeated in natural history texts for more than a thousand years despite the fact that a little counting would have proven otherwise." However, the historian and philosopher of biology John S
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History of Animals Wilkins notes that Aristotle did not say "all flies have four legs"; he wrote that one particular animal, the "ephemeron" or mayfly, "moves with four feet and four wings: and, I may observe in passing, this creature is exceptional not only in regard to the duration of its existence, whence it receives its name, but also because though a quadruped it has wings also." Mayflies do in fact walk on four legs, the front pair not being adapted for walking, so, Wilkins concludes, Aristotle was correct. More generally, Aristotle's biology, described across the five books sometimes called "On Animals" and some of his minor works, the "Parva Naturalia", defines what in modern terms is a set of models of metabolism, temperature regulation, information processing, inheritance, and embryogenesis. All of these are wrong in the sense that modern science has replaced them with different models, but they were scientific in that they attempted to explain observed phenomena, proposed mechanisms, and made testable predictions. The Arabic translation comprises treatises 1–10 of the "Kitāb al-Hayawān" ("The Book of Animals"). It was known to the Arab philosopher Al-Kindī (d. 850) and commented on by Avicenna among others. It was in turn translated into Latin, along with Ibn Rushd (Averroes)'s commentary on it, by Michael Scot in the early 13th century. English translations were made by Richard Cresswell in 1862 and by the zoologist D'Arcy Wentworth Thompson in 1910
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History of Animals A French translation was made by Jules Barthélemy-Saint-Hilaire in 1883. Another translation into French was made by J. Tricot in 1957, following D'Arcy Thompson's interpretation. A German translation of books I–VIII was made by Anton Karsch, starting in 1866. A translation of all ten books into German was made by Paul Gohlke in 1949. The comparative anatomist Richard Owen said in 1837 that "Zoological Science sprang from [Aristotle's] labours, we may almost say, like Minerva from the Head of Jove, in a state of noble and splendid maturity". Ben Waggoner of the University of California Museum of Paleontology wrote that Walter Pagel comments that Aristotle "perceptibly influenced" the founders of modern zoology, the Swiss Conrad Gessner with his 1551–1558 "Historiae animalium", the Italian Ulisse Aldrovandi (1522–1605), the French Guillaume Rondelet (1507–1566), and the Dutch Volcher Coiter (1534–1576), while his methods of looking at time series and making use of comparative anatomy assisted the Englishman William Harvey in his 1651 work on embryology. Armand Marie Leroi's 2014 book "The Lagoon: How Aristotle Invented Science" and BBC documentary "Aristotle's Lagoon" set Aristotle's biological writings including the "History of Animals" in context, and propose an interpretation of his biological theories.
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The Naturalist on the River Amazons The Naturalist on the River Amazons, subtitled "A Record of the Adventures, Habits of Animals, Sketches of Brazilian and Indian Life, and Aspects of Nature under the Equator, during Eleven Years of Travel", is an 1863 book by the British naturalist Henry Walter Bates about his expedition to the Amazon basin. Bates and his friend Alfred Russel Wallace set out to obtain new species and new evidence for evolution by natural selection, as well as exotic specimens to sell. He explored thousands of miles of the Amazon and its tributaries, and collected over 14,000 species, of which 8,000 were new to science. His observations of the coloration of butterflies led him to discover Batesian mimicry. The book contains an evenly distributed mixture of natural history, travel, and observation of human societies, including the towns with their Catholic processions. Only the most remarkable discoveries of animals and plants are described, and theories such as evolution and mimicry are barely mentioned. Bates remarks that finding a new species is only the start; he also describes animal behaviour, sometimes in detail, as for the army ants. He constantly relates the wildlife to the people, explaining how the people hunt, what they eat and what they use as medicines. The book is illustrated with drawings by leading artists including E. W. Robinson, Josiah Wood Whymper, Joseph Wolf and Johann Baptist Zwecker. On Bates's return to England, he was encouraged by Charles Darwin to write up his eleven-year stay in the Amazon as a book
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https://en.wikipedia.org/wiki?curid=1696077
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The Naturalist on the River Amazons The result was widely admired, not least by Darwin; other reviewers sometimes disagreed with the book's support for evolution, but generally enjoyed his account of the journey, scenery, people, and natural history. The book has been reprinted many times, mostly in Bates's own effective abridgement for the second edition, which omitted the more technical descriptions. The first edition, in 1863, was long and full of technical description. The second edition, in 1864, was abridged, with most of the technical description removed, making for a shorter and more readable book which has been reprinted many times. Bates prefaced the 1864 edition by writing An unabridged edition was reissued only after 30 years, in 1892; it appeared together with a 'memoir' of Bates by Edward Clodd. In 1847, Bates and his friend Alfred Russel Wallace, both in their early twenties, agreed that they would jointly make a collecting trip to the Amazon "towards solving the problem of origin of species". They had been inspired by reading the American entomologist William Henry Edwards's pioneering 1847 book "A Voyage Up the River Amazon, with a residency at Pará". Neither had much money, so they determined to fund themselves by collecting and selling fine specimens of birds and insects. Both made extensive travels — in different parts of the Amazon basin — creating large natural history collections, especially of insects
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https://en.wikipedia.org/wiki?curid=1696077
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The Naturalist on the River Amazons Wallace sailed back to England in 1852 after four years; on the voyage, his ship caught fire, and his collection was destroyed; undeterred, he set out again, leading eventually (1869) to a comparable book, "The Malay Archipelago". By the time he came home in November 1859, Bates had collected over 14,000 species, of which 8,000 were new to science. His observations of the coloration of butterflies led him to describe what is now called Batesian mimicry, where an edible species protects itself from predators by appearing like a distasteful species. Bates's account of his stay, including observations of nature and the people around him, occupies his book. In the abridged version, there is a balance between descriptions of places and adventures, and the wildlife seen there. The style is accurate, but vivid and direct: The book begins and ends suddenly. The journey out, as reviewer Joseph James observes, is dismissed in a few words. The last few lines of the book run: There are 39 illustrations, some of animals and plants, some of human topics such as the "Masked-dance and wedding-feast of Tucuna Indians", which is signed by Josiah Wood Whymper. Some illustrations including "Turtle Fishing and Adventure with Alligator" are by the German illustrator Johann Baptist Zwecker; some, such as "Bird-Killing Spider (Mygale Avicularia) Attacking Finches" are by E.W. Robinson; others by the zoological artist Joseph Wolf
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https://en.wikipedia.org/wiki?curid=1696077
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The Naturalist on the River Amazons The structure of the readable, cut-down second edition of 1864 is as follows: Charles Darwin, having encouraged Bates to publish an account of his travels, read "The Naturalist on the River Amazons" with great pleasure, writing to Bates on 18 April 1863 that Darwin noted in his letter that "Athenaeum" magazine reviewed the book coldly and insolently, while the "Reader" received it warmly. Darwin published "An Appreciation" of the book in the "Natural History Review" in 1863, in which he notes that Bates sent back "a mass of specimens" of "no less than 14,712 species" (mostly of insects), of which 8000 were new to science. Darwin at once observes that although Bates is "no mean authority" on insects, the book is not limited to them, but ranges over natural history and more widely to describe his "adventures during his journeyings up and down the mighty river". Darwin clearly enjoyed Bates's account of the hyacinthine macaw, calling it a "splendid bird" with its "enormous beak" able to feed on mucuja palm nuts, and quoting Bates: "which are so hard as to be difficult to break with a heavy hammer, are crushed to a pulp by the powerful beak of this Macaw." Darwin took the opportunity to hit back at the "Athenaeum" magazine which had criticised Bates's book, at the same time painting a picture of Bates's lonely life in the rainforest: Darwin notes that "We need hardly say that Mr. Bates..
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https://en.wikipedia.org/wiki?curid=1696077
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The Naturalist on the River Amazons is a zealous advocate of the hypothesis of the origin of species by derivation from a common stock", in other words that Bates was a staunch Darwinian. Darwin was happy to have the "Naturalist" on his side, and to use the book in the "Origin of Species" debate which was still heated in 1863. In particular, Darwin was struck by Bates's robust evidence of mimicry in "the Butterflies of the genus "Heliconius"". Here Darwin quotes nearly a whole page from Bates's conclusions, including Bates's view of his own findings that hint at speciation actually in progress: The "London Quarterly Review" began with the observation that "When an intelligent man tells us that he has spent eleven of the best years of his life in any district, we may be pretty sure he has something to say about it which will interest even those who generally find travels dull reading". The reviewer finds Bates among the most readable, and free of the usual "personal twaddle" of travel and adventure books. The reviewer also remarks on Bates's subtitle "...of the origin of species", that Wallace had taken up that theme more fully. In the reviewer's opinion, Bates says little about "the Darwinian hypothesis", focusing instead steadily on natural history, while making "very shrewd remarks" about human society and giving "most glowing" descriptions of tropical scenery
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https://en.wikipedia.org/wiki?curid=1696077
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