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Recluse Spider
The recluse spiders (''Loxosceles'' (), also known as brown spiders, fiddle-backs, violin spiders, and reapers, is a genus of spiders that was first described by R. T. Lowe in 1832. They are venomous spiders known for their bite, which sometimes produces a characteristic set of symptoms known as loxoscelism. Recluse spiders are now identified as members of the family Sicariidae, having formerly been placed in their own family, the Loxoscelidae. Although recluse spiders are feared, they are usually not aggressive. Relation with other spiders Sicariidae are of the superfamily Scytodoidea. Other families in the Scytodoidea include Drymusidae, Scytodidae, and Periegopidae. Habitat and appearance ''Loxosceles'' is distributed nearly worldwide in warmer areas. All have six eyes arranged in three groups of two (dyads) and some are brownish with a darker brown characteristic violin marking on the cephalothorax. However, the "violin marking" cannot be used as a reliable way to ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Recluse Spider
The brown recluse (''Loxosceles reclusa''), Sicariidae (formerly placed in a family "Loxoscelidae") is a recluse spider with necrotic venom. Similar to those of other recluse spiders, their bites sometimes require medical attention. The brown recluse is one of three spiders in North America with medically significant venom, the others being the black widow and the Chilean recluse. Brown recluse spiders are usually between , but may grow larger. While typically light to medium brown, they range in color from whitish to dark brown or blackish gray. The cephalothorax and abdomen are not necessarily the same color. These spiders usually have markings on the dorsal side of their cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddleback spider, brown fiddler, or violin spider. Description The violin pattern is not a definitive identifier, as other spiders can have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider Bite
A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain. Most spiders do not cause bites that are of importance. For a bite to be significant, substantial envenomation is required. Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism. Symptoms may include pain which may be at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others. Bites from the recluse spiders cause the condition loxoscelism, in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur. Headaches, vomiting and a mild fever may also occur. Other spiders that can cause significant bites include the Australian funnel-web spider and South American wandering spider. Efforts to preve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loxosceles Gaucho
''Loxosceles gaucho'' commonly known in English as the gaucho spider. is a highly venomous recluse spider endemic to South America. Description and behavior Adult females grow up to 7–12 mm, the maximum reported is 14 mm. They are mainly characterized by their brown color, leading to them be colloquially referred to as ''''Aranha marrom'''' (Portuguese for brown spider) in Brazil, the body is characterized by a pale to dark brown color (often reddish), with a dorsal violin-shaped mark, slightly darker on the carapace, with long and slender legs, without dark marks or stripes. Males have the thoracic region with the clearest impression, consisting of bands, with the anterior portion of the cephalothorax forming in the rear direction a '' V '' design, while pedipalps have the last short articles and curved stylus. Females have the anterior portion of the cephalothorax forming a '' U '' shape backwards. Like many recluse spiders, It is nocturnal, hunting preys such as i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalothorax
The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cephalothorax'' and ''abdomen'' in some groups.) The word ''cephalothorax'' is derived from the Greek words for head (, ') and thorax (, '). This fusion of the head and thorax is seen in chelicerates and crustaceans; in other groups, such as the Hexapoda (including insects), the head remains free of the thorax. In horseshoe crabs and many crustaceans, a hard shell called the carapace covers the cephalothorax. Arachnid anatomy Fovea The fovea is the centre of the cephalothorax and is located behind the head (only in spiders).Dalton, Steve (2008). ''Spiders; The Ultimate Predators''. A & C Black, London. P.p. 19. . It is often important in identification. It can be transverse or procurved Smith, A. M. (1990c). Baboon spiders: Tarantulas of Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleoside
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building-blocks of DNA and RNA. List of nucleosides and corresponding nucleobases The reason for 2 symbols, shorter and longer, is that the shorter ones are better for contexts where explicit disambiguation is superfluous (because context disambiguates) and the longer ones are for contexts where explicit disambiguation is judged to be needed or wise. For example, when discussing long nucleobase sequences in genomes, the CATG symbol system is much preferable to the Cyt-Ade-Thy-Gua symbol system (see '' N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfate
The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many are prepared from that acid. Spelling "Sulfate" is the spelling recommended by IUPAC, but "sulphate" was traditionally used in British English. Structure The sulfate anion consists of a central sulfur atom surrounded by four equivalent oxygen atoms in a tetrahedral arrangement. The symmetry is the same as that of methane. The sulfur atom is in the +6 oxidation state while the four oxygen atoms are each in the −2 state. The sulfate ion carries an overall charge of −2 and it is the conjugate base of the bisulfate (or hydrogensulfate) ion, , which is in turn the conjugate base of , sulfuric acid. Organic sulfate esters, such as dimethyl sulfate, are covalent compounds and esters of sulfuric acid. The tetrahedral molecular geometry of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingomyelinase D
Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, resulting in the formation of ceramide 1-phosphate and choline: : sphingomyelin + H2O \rightleftharpoons ceramide 1-phosphate + choline or the hydrolysis of 2-lysophosphatidylcholine to give choline and 2-lysophosphatidate. Sphingomyelin phosphodiesterase D activity is shared by enzymes with a wider substrate range, classified as phospholipases D or lipophosphodiesterase II . Sphingomyelinases D are produced by some spiders in their venoms, specifically the brown recluse (''Loxosceles reclusa''), by arthropods such as ticks, or pathogenic bacteria and fungi. Pathogenicity is expressed through different mechanisms, such as membrane destabilization, cell penetration, inflammation of the lungs and cutaneous lesions, common following brown rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venom (poison)
Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism. Venom has evolved in terrestrial and marine environments and in a wide variety of animals: both predators and prey, and both vertebrates and invertebrates. Venoms kill through the action of at least four major classes of toxin, namely necrotoxins and cytotoxins, which kill cells; neurotoxins, which affect nervous systems; myotoxins, which damage muscles; and haemotoxins, which disrupt blood clotting. Venomous animals cause tens of thousa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotoxic
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells with the cytotoxic compound can result in a variety of cell fates. The cells may undergo necrosis, in which they lose membrane integrity and die rapidly as a result of cell lysis. The cells can stop actively growing and dividing (a decrease in cell viability), or the cells can activate a genetic program of controlled cell death (apoptosis). Cells undergoing necrosis typically exhibit rapid swelling, lose membrane integrity, shut down metabolism, and release their contents into the environment. Cells that undergo rapid necrosis in vitro do not have sufficient time or energy to activate apoptotic machinery and will not express apoptotic markers. Apoptosis is characterized by well defined cytological and molecular events including a change i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexophthalma
''Hexophthalma'' is a genus of spiders in the family Sicariidae. Although the genus was originally erected in 1878 (then with the name ''Hexomma''), it was merged into the genus '' Sicarius'' in the 1890s, and remained unused until revived in 2017, when it was discovered that the African species then placed in ''Sicarius'' were distinct. The English name six-eyed sand spiders is used for members of the genus, particularly ''Hexophthalma hahni''. Species in the genus have necrotic (dermonecrotic) venom, and can potentially cause serious or even life-threatening wounds. Taxonomy The genus was first created in 1878 by Friedrich Karsch as ''Hexomma'', with the sole species '' Hexomma hahni''. By 1879, though, Karsch had realized that this name had already been used in 1877 for a species of harvestman, so he published the replacement name ''Hexophthalma''. In 1893, Eugène Simon transferred ''Hexophthalma hahni'' to the genus '' Sicarius'', and ''Hexophthalma'' fell out of use, until ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kansas State University
Kansas State University (KSU, Kansas State, or K-State) is a public land-grant research university with its main campus in Manhattan, Kansas, United States. It was opened as the state's land-grant college in 1863 and was the first public institution of higher learning in the state of Kansas. It had a record high enrollment of 24,766 students for the Fall 2014 semester. The university is classified among "R1: Doctoral Universities – Very high research activity". Kansas State's academic offerings are administered through nine colleges, including the College of Veterinary Medicine and the College of Technology and Aviation in Salina. Graduate degrees offered include 65 master's degree programs and 45 doctoral degrees. Branch campuses are in Salina and Olathe. The Kansas State University Salina Aerospace and Technology Campus is home to the College of Technology and Aviation. The Olathe Innovation Campus has a focus on graduate work in research bioenergy, animal health, pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
