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Araneus Gemma
''Araneus gemma'', commonly known as the cat-faced spider (a name shared with '' Araneus gemmoides''), is a common outdoor orb-weaver spider found in the western United States and Canada. Like most Araneus species, ''A. gemma'' is harmless to humans. It contains a venomous toxin of low molecular weight called argiotoxin Argiotoxins represent a class of polyamine toxins isolated from the orb-weaver spider ('' Araneus gemma'' and '' Argiope lobata''). The orb-weaver spiders, also known aaraneids belong to the Araneidae spider family. This type of spider is found i ..., that antagonizes the actions of the neurotransmitter glutamate. Dopamine was also identified in the venom of ''A. gemma'' in a concentration of 4.3 nM. The web silk of the ''A. gemma'' ranges from 1 to 4 μm in diameter.David Kaplan, Kevin McGrathProtein-Based MaterialsSpringer, 1997; page 113. . References External links gemma Spiders of North America Spiders described in 1888 {{Araneidae-st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Christopher McCook
Henry Christopher McCook (July 3, 1837 – 1911) was an American Presbyterian clergyman, natural history, naturalist, and prolific author on religion, history, and nature. He was a member of the celebrated Fighting McCooks, a family of Ohio in the American Civil War, Ohio military officers and volunteers during the American Civil War. Life and work McCook was born in Lisbon, Ohio, New Lisbon, Ohio, to Dr. John James McCook, John McCook and Julia Sheldon McCook. He learned the printing trade as a youth, then taught school for several years. attended Washington and Jefferson College, Jefferson College. He was a member of the Literary societies at Washington & Jefferson College#Franklin Literary Society, Franklin Literary Society and founded the chapter of Theta Delta Chi at Washington & Jefferson College, Jefferson College. After graduation in 1859, he studied theology privately and in the Reformed Presbyterian Theological Seminary, Western Theological Seminary in Allegheny Cente ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneus Gemmoides
''Araneus gemmoides'', commonly known as the jewel spider (a name shared with ''Austracantha minax'') and cat-faced spider (a name shared with ''Araneus gemma''), is a common, outdoor, orb-weaver spider found in Canada and the USA. It is considered harmless and has a low-toxicity venom. ''A. gemmoides'' is a useful natural predator for insects. ''A. gemmoides'' makes its webs near lights, closed spaces, and on the sides of buildings. It can also be found under wood, overhangs, or guarded places such as animal burrows. The species occurs in varying colors, but is easily identified by the two horn-shaped growths on its relatively large abdomen. Its color changes from summer to winter. The females die within days of laying a single egg sac with hundreds of eggs. Egg sacs can survive over winter, and the emerging spiderlings eat their siblings. The babies ride strands of silk in warm air currents, which are able to transport them to locations miles away. Females have a larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orb-weaver Spider
Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs. The family has a cosmopolitan distribution, including many well-known large or brightly colored garden spiders. With 3,108 species in 186 genera worldwide, the Araneidae comprise the third-largest family of spiders (behind the Salticidae and Linyphiidae). Araneid webs are constructed in a stereotypical fashion, where a framework of nonsticky silk is built up before the spider adds a final spiral of silk covered in sticky droplets. Orb webs are also produced by members of other spider families. The long-jawed orb weavers (Tetragnathidae) were formerly included in the Araneidae; they are closely related, being part of the superfamily Arane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneus
''Araneus'' is a genus of common orb-weaving spiders. It includes about 650 species, among which are the European garden spider and the barn spider. The genus was erected by Carl Alexander Clerck in 1757. Description Spiders of this genus present perhaps the most obvious case of sexual dimorphism among all of the orb-weaver family, with males being normally to the size of females. In ''A. diadematus'', for example, last-molt females can reach the body size up to 1 in (2.5 cm), while most males seldom grow over 0.3 in (1 cm), both excluding leg span. Males are differentiated from females by a much smaller and more elongated abdomen, longer legs, and the inability to catch or consume prey bigger than themselves. In females, the epigyne has a long scape (a tongue-like appendage). Male pedipalps have a hook-like terminal apophysis. Abdominal tubercles are present anterolaterally. Taxonomic history ''Araneus'' was, for much of its history, called ''Epeira''. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argiotoxin
Argiotoxins represent a class of polyamine toxins isolated from the orb-weaver spider (''Araneus gemma'' and ''Argiope lobata''). The orb-weaver spiders, also known aaraneids belong to the Araneidae spider family. This type of spider is found in almost every area of the world. : Classification Argiotoxin can be classified, according to the 1980s classification of spider venoms, as a toxin of the acylpolyamines family, which contains more than 100 different chemical structures of closely related toxins. Acylpolyamines are neurotoxic compounds that are found only in the venom glands of spiders at a picomolar level. Argiotoxins are classified into three different categories according to its chromophore's nature: the argiopine type, the argiopinine type and the pseudoargiopinine type. * Argiopine: contains 2,4-dihydroxyphenylacetic acid. It is also named Arg-636. * Argiopinines: (4-hydroxyindol-3-yl) acetic acid is carried as the chromophore. These molecules are: Arg-630, Arg-658, A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glutamate
Glutamic acid (symbol Glu or E; the ionic form is known as glutamate) is an α-amino acid that is used by almost all living beings in the biosynthesis of proteins. It is a non-essential nutrient for humans, meaning that the human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system. It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons. Its molecular formula is . Glutamic acid exists in three optically isomeric forms; the dextrorotatory -form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.Webster's Third New International Dictionary of the English Language Unabridged, Third Edition, 1971. Its molecular structure could be idealized as HOOC−CH()−()2−COOH, with two carboxyl groups −COOH and one amino group −. However, in the solid state and mildly acidic water solu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dopamine
Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic compound, organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% of the catecholamine content in the brain. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor (chemistry), precursor chemical, L-DOPA, which is biosynthesis, synthesized in the brain and kidneys. Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons (nerve cells) to send signals to other nerve cells. Neurotransmitters are synthesized in specific regions of the brain, but affect many regions systemically. The brain includes several distinct dopaminergic pathway, dopamine pathways, one of which plays a major role in the motivational component of reward system, reward-motivated behavior. The anticipa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mole (unit)
The mole, symbol mol, is the unit of amount of substance in the International System of Units (SI). The quantity amount of substance is a measure of how many elementary entities of a given substance are in an object or sample. The mole is defined as containing exactly elementary entities. Depending on what the substance is, an elementary entity may be an atom, a molecule, an ion, an ion pair, or a subatomic particle such as an electron. For example, 10 moles of water (a chemical compound) and 10 moles of mercury (a chemical element), contain equal amounts of substance and the mercury contains exactly one atom for each molecule of the water, despite the two having different volumes and different masses. The number of elementary entities in one mole is known as the Avogadro number, which is the approximate number of nucleons (protons or neutrons) in one gram of ordinary matter. The previous definition of a mole was simply the number of elementary entities equal to that of 12 gram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . The longest human chromosome, chromosome 1, is approximately in length. Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiders Of North America
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
