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14,427,537 | https://en.wikipedia.org/wiki/GPR32 | G protein-coupled receptor 32, also known as GPR32 or the RvD1 receptor, is a human receptor (biochemistry) belonging to the rhodopsin-like subfamily of G protein-coupled receptors.
Gene
The GPR32 was initially identified and defined by molecular cloning in 1998 as coding for an orphan receptor, i.e. a protein with an amino acid sequence similar to known receptors but having no known ligand(s) to which it responds and no known function. The projected amino acid sequence of GPR32, however, shared 35-39% amino acid identity with certain members of the chemotactic factor receptor family, i.e. 39% identity with Formyl peptide receptor 1, which is a receptor for N-Formylmethionine-leucyl-phenylalanine and related N-formyl peptide chemotactic factors, and 35% identity with Formyl peptide receptor 2, which likewise is also a receptor for N-formyl peptides but also a receptor for certain lipoxins which are arachidonic acid metabolites belonging to a set of specialized proresolving mediators that act to resolve or inhibit inflammatory reactions. GPR32 mapped to chromosomal 19, region q13.3. There are no mouse or other orthologs of GPR32.
Receptor
The GPR32 protein is a G protein coupled receptor although the specific G protein subtypes which it activates has not yet been reported. GPR32 is expressed in human blood neutrophils, certain types of blood lymphocytes (i.e. activated CD8+ cells, CD4+ T cells, and T helper 17 cells), tissue macrophages, small airway epithelial cells, and adipose tissue. When expressed in Chinese hamster ovary cells, GPR32 inhibits the Cyclic adenosine monophosphate signaling pathway under both baseline and forskolin-stimulated conditions indicating that it is a member of the class of orphan G protein coupled receptors that possesses constitutive signaling activity.
At least 6 members of the D series of resolvins (RvDs) viz., RvD1, RvD2m AT-RVD1, RvD3, AT-RvD3, and RvD5, activate their target cells through this receptor; these results have led to naming GPR32 the RVD1 receptor (see resolvin mechanisms of action). RvDs are members of the specialized proresolving mediators (SPM) class of polyunsaturated fatty acid metabolites. RVDs are metabolites of the omega-3 fatty acid, docosahexaenoic acid (DHA), and, along with other SRMs contribute to the inhibition and resolution of a diverse range of inflammation and inflammation-related responses as well as to the healing of these inflammatory lesions in animals and humans. The metabolism of DHA to RVD's and the activation of GPR32 by these RVD's are proposed to be one mechanism by which omega-3 fatty acids may ameliorate inflammation as well as various inflammation-based and other diseases.
References
Further reading
G protein-coupled receptors | GPR32 | [
"Chemistry"
] | 670 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,542 | https://en.wikipedia.org/wiki/GPR33 | Probable G-protein coupled receptor 33 is a protein that in humans is encoded by the GPR33 gene.
References
Further reading
G protein-coupled receptors | GPR33 | [
"Chemistry"
] | 32 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,548 | https://en.wikipedia.org/wiki/GPR34 | Probable G-protein coupled receptor 34 is a protein that in humans is encoded by the GPR34 gene. The receptor binds to lysophosphatidylserine.
Function
G protein-coupled receptors (GPCRs), such as GPR34, are integral membrane proteins containing 7 putative transmembrane domains (TMs). These proteins mediate signals to the interior of the cell via activation of heterotrimeric G proteins that in turn activate various effector proteins, ultimately resulting in a physiologic response.[supplied by OMIM]
References
Further reading
G protein-coupled receptors | GPR34 | [
"Chemistry"
] | 128 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,589 | https://en.wikipedia.org/wiki/GPR37 | Probable G-protein coupled receptor 37 is a protein that in humans is encoded by the GPR37 gene. GPR37 is primarily found in the central nervous system (CNS), with significant expression observed in various CNS regions including the amygdala, basal ganglia (caudate, putamen, and nucleus accumbens), substantia nigra, hippocampus, frontal cortex, and hypothalamus, particularly noteworthy is its exceptionally elevated expression in the spinal cord.
Interactions
GPR37 has been shown to interact with HSPA1A and Parkin (ligase). GPR37 is a receptor for prosaposin. It was previously thought to be a receptor for head activator, a neuropeptide found in the hydra, but early reports of head activator in mammals were never confirmed. To address challenges in confirming ligand-GPR37 interactions using recombinant GPR37 expressed in HEK293 cells, recent research has turned to primary cell cultures, leading to successful ligand identification. These investigations have unveiled the involvement of osteocalcin with GPR37 to regulate processes such as oligodendrocyte differentiation, myelination, myelin production, and remyelination following demyelinating injuries. Furthermore, osteocalcin treatment has demonstrated protective effects against Lipopolysaccharide-induced inflammation, which are absent in GPR37-deficient mice.
GPR37 signaling has been shown to modulate the migration of olfactory ensheathing cells (OECs) and gonadotropin-releasing hormone (GnRH) cells in mice.
References
Further reading
G protein-coupled receptors | GPR37 | [
"Chemistry"
] | 357 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,635 | https://en.wikipedia.org/wiki/GPR39 | G-protein coupled receptor 39 is a protein that in humans is encoded by the GPR39 gene.
References
Further reading
G protein-coupled receptors | GPR39 | [
"Chemistry"
] | 31 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,686 | https://en.wikipedia.org/wiki/Free%20fatty%20acid%20receptor%201 | Free fatty acid receptor 1 (FFAR1), also known as G-protein coupled receptor 40 (GPR40), is a rhodopsin-like G-protein coupled receptor that is coded (i.e., its synthesis is directed) by the FFAR1 gene. This gene is located on the short (i.e., "q") arm of chromosome 19 at position 13.12 (location notated as 19q13.12). G protein-coupled receptors (also termed GPRs or GPCRs) reside on their parent cells' surface membranes, bind any one of the specific set of ligands that they recognize, and thereby are activated to trigger certain responses in their parent cells. FFAR1 is a member of a small family of structurally and functionally related GPRs termed free fatty acid receptors (FFARs). This family includes at least three other FFARs viz., FFAR2 (also termed GPR43), FFAR3 (also termed GPR41), and FFAR4 (also termed GPR120). FFARs bind and thereby are activated by certain fatty acids.
Studies suggest that FFAR1 may be involved in the development of obesity, type 2 diabetes, and various emotional, behavioral, learning, and cognition defects such as Alzheimer's disease. FFAR1 may also be involved in the perception of pain, the tastes of and preferences for eating fatty and sweet foods, the pathological replacement of injured tissue with fibrosis and scarring, and the malignant behavior, i.e., proliferation, invasiveness, and metastasis, of some types of cancer cells.
Various fatty acids, including in particular two omega-3 fatty acids, docosahexaenoic and eicosapentaenoic acids, have been consumed in diets and supplements for the purposes of preventing or treating the disorders that recent studies suggest are associated with abnormalities in FFAR1's functions. It is now known that these fatty acids activate (i.e. are agonists of) FFAR1 as well as FFAR4. While dietary and supplemental omega-3 fatty acids have had no or only marginally significant therapeutic effects on these disorders (see health effects of omega-3 fatty acid supplementation), drugs have been developed that are more potent and selective in activating FFAR1 than the omega-3 fatty acids. Furthermore, drugs have been developed that potently inhibit (i.e. are antagonists of) FFAR1. This raised the possibility that the drugs may be more effective than the omega-3 fatty acids in treating these diseases and prompted studies testing their effectiveness to do so. These studies, which are preclinical studies on cultured cells and animal models of disease plus some clinical studies, are detailed here.
Activators and inhibitors of the free fatty acid receptors
FFARs are activated by specific types of fatty acids. FFAR2 and FFAR3 are activated by short-chain fatty acids (i.e., fatty acid chains consisting of 2 to 5 carbon atoms) such as acetic, butyric, and propionic acids. FFAR1 and FFAR4 are activated by 1) medium-chain fatty acids (i.e., fatty acids consisting of 6-12 carbon atoms) such as capric and lauric acids; 2) long-chain and very long-chain fatty acids (i.e. fatty acids consisting respectively of 13 to 21 or more than 21 carbon atoms) unsaturated fatty acids such as myristic and steric acids; 3) long chain monounsaturated fatty acidss such as oleic and palmitoleic acids; 4) long and very long chain polyunsaturated fatty acids such as the omega-3 fatty acids alpha-linolenic, eicosatrienoic, eicosapentaenoic, and docosahexaenoic acids and omega-6 fatty acids such as linoleic, gamma-linolenic, dihomo-gamma-linolenic, arachidonic, and docosatetraenoic acids; and 5) the omega hydroxy fatty acid, 20-hydroxyeicosatetraenoic acid. Among the fatty acids that activate FFAR1 (and FFAR4), docosahexaenoic and eicosapentaenoic acids are commonly regarded as the main dietary fatty acids that do so and may be useful therapeutic agents.
The drugs that are full agonists (i.e., can fully activate) FFAR1 include GW5809 (about 60-fold more potent in activating FFAR1 than FFAR4) and five drugs, AM 1638, AP8, compound 1 SCO-267, and T-3601386 which have no reports clearly defining their ability to activate FFAR4. The drugs that are partial agonists (i.e., activate but cannot fully activate) FFAR1 include TAK-875, also termed fasiglifam, which is >1,000 more potent in activating FFAR1 than FFAR4, MK‐8666, which activates FFAR1 and said to be less effective in activating FFAR4, and two drugs, AMG 837T and LY3104607 which have no reports clearly defining their ability to activate FFAR4. GW1100 and ANT203 are antagonist, i.e., inhibit the activation, of FFAR1 but do not inhibit FFAR4 and DC260126 which inhibits FFAR1 but its effect on FFAR4 has not been clearly reported. ZLY50 is a newly described selective FFAR1 agonist (>400 more potent in activating FFAR1 than FFAR4) that crosses the blood–brain barrier and therefore may prove useful for inhibiting FFAR1 on cells located in the central nervous system, i.e. brain and spinal cord.
Cells commonly express both FFAR1 and FFAR4. The fatty acids which activate these two FFARs, including docosahexaenoic and eicosapentaenoic acids, are about equally potent in activating FFAR1 and FFAR4; they also have diverse FFAR1-independent as well as FFAR4-independent means of altering cell functions. Furthermore, most of the studies on FFAR1 agonist drugs have used GW9508, a drug that activates FFAR1 but at higher concentrations also activates FFAR4. Finally, many of the FFAR1 agonists and antagonists have not been defined for their impact on FFAR4 and none of them have been fully evaluated for possible FFAR-independent means of altering cell functions. Accordingly, many FFAR1 studies have not clearly determined if the action(s) of a given fatty acid or drug involves FFAR1, FFAR4, both FFARs, FFAR-independent pathways, or combinations of these function-altering avenues. The studies reported here address these issues by focusing on those that included examinations of the effects of FFAR1 and FFAR4 inhibitors by themselves or as blockers of the actions of FFAR1 and FFAR4 and/or included experiments using cells or animals that lacked, under-expressed, or overexpressed FFAR1 or FFAR4.
Cells and tissues expressing FFAR1
FFAR1 is highly expressed in pancreas beta cells which produce and release insulin into the blood; pancreas alpha cells which produce and release glucagon, a hormone that increases blood glucose levels; enteroendocrine K, L, and I cells of the gastrointestinal tract which respectively produce and release glucagon-like peptide-1, gastric inhibitory peptide, and cholecystokinin which regulate insulin and blood glucose levels; monocytes and M2 macrophages which contribute to regulating immune responses such as inflammation; bone modeling cells (i.e. osteoblasts and osteoclasts); and taste receptor-bearing cells in the tongue's taste buds. FFAR1 is also expressed in bone marrow-derived macrophages; neurons in the central nervous system, e.g. the olfactory bulb, striatum, hippocampus, midbrain, hypothalamus, cerebellum, cerebral cortex, caudate nucleus and spinal cord; various cell types in the spleen; and various types of cancer cells.
FFAR1 functions and activities
Fat tissue development and thermogenesis
Studies to date have implicated FFAR4 but not FFAR1 in the development and remodeling of fat tissue and in generating body heat, i.e., thermogenesis, by the brown fat component of fat tissue (see FFAR4) in rodents. Indeed, FRAR1 has not yet been reported to be expressed in the fat tissue of mice or humans.
Obesity
The following studies have suggested that FFAR1 contributes to the regulation of obesity. 1) Ffar1 gene knockout mice (i.e., mice made to lack Ffar1 genes) became obese when fed a low-fat diet whereas control mice became obese only when fed a high-fat diet. 2) The FFAR1 agonist SCO-267 reduced the food intake and body weights in diet-induced obese rats, in rats made diabetic by neonatal treatment with streptozotocin, and in obese mice but not in Ffar1 knockout obese mice. 3) Another FFAR1 agonist, T-3601386, likewise reduced the food intake and body weight in obese mice but not in Ffar1 gene knockout mice. 4) SNP genotyping is used to define single-nucleotide polymorphisms in order to detect germline substitutions of a single nucleotide at specific positions in all the genetic material of an organism. SNP genotyping found three variant FFAR1 gene SNPs in individuals with higher body weights, body mass indexes, and fatty tissue masses than individuals not carrying one of these SNP genes. The SNP gene carriers did not evidence abnormal insulin or pancreatic beta cell functions. This study suggested but did not show that the cited SNP FFAR1 protein variants were dysfunctional. And 5) a similar study found another SNP in the FFAR1 gene. This SNP replaced serine with glycine at the 180th amino acid of FFAR1. It and the more common FFAR1 protein it replaces are termed Gly180Ser and Gly180Gly, respectively. Gly180Ser FFAR1 was present in 0.42, 1.8, and 2.60% of non-obese, moderately obese, and severely obese individuals, respectively, and its carriers showed reduced plasma insulin responses to an oral lipid challenge. Studies on HeLa cells (i.e., cells derived from human cervical cancer cells) made to express Gly180Ser FFAR1 using transfection methods had significantly lower calcium mobilization responses to oleic acid than Hela cells transfected with Gly180Gly FFAR1. This suggests that Gly180Ser FFAR1 is dysfunctional. Modulation of the nutrient taste-sensing pathways (see below section on Taste) using foods, dietary supplements, or drugs that target FFAR1 (and FFAR4, see FFAR4-dependent taste perception) may prove useful for treating obesity and obesity-related disorders.
Type 2 diabetes
Studies have suggested that FFAR1 acts to suppress the development and/or pathological effects (e.g. inadequate insulin secretion) of type 2 diabetes. 1) Fatty acid activators of FFAR1/FFAR4 enhanced the glucose-stimulated secretion of insulin from cultured mouse pancreas beta-cells, INS-1 rat beta cells, mouse MIN6 beta cells (these cells like other beta cells make and release insulin but are genetically altered to also make and release glucagon, somatostatin, and ghrelin), and pancreatic islets isolated from humans. These fatty acid activators did not have this action in the absence of concurrent glucose stimulation. 2) The FFAR1 agonist TAK-875 increased the amount of insulin released by glucose-stimulated cultured INS-1 cells and isolated rat pancreatic islets. TAK-875 did not have this action in the absence of concurrent glucose stimulation. 3) The FFAR1 agonist AMG 837 stimulated mouse MIN6 cells to secrete insulin; it also reduce the rises in plasma glucose occurring in glucose tolerance tests in control but not Ffar1 gene knockout mice. 4) Other FFAR1 agonist drugs including TUG-424, AM-1638, AM-5262, LY2881835, MK-2305, and ZLY50 increased insulin secretion and improved glucose tolerance in mice, enhanced glucose-stimulated insulin secretion in mouse and human cultured pancreatic islet cells, and/or improved glucose levels in diabetic mice. 5) Ffar1 gene knockout mice had impaired secretion of glucagon-like peptide-1 and gastric inhibitory polypeptide into the circulation. These two hormones are secreted from intestinal L-cells and intestinal K-cells, respectively, when stimulated by dietary glucose or fatty acids and act to promote insulin secretion. And 6) Ffar1 gene knockout mice fed a high-fat diet for 11 weeks developed obesity, high fasting blood glucose levels, glucose intolerance, and insulin resistance; control mice feed the high fat diet did not develop these diabetic-like abnormalities. Thus, FFAR1 appears to regulate insulin secretion and blood glucose levels thereby suppressing the development and/or pathological consequences of type 2 diabetes in rodents.
A double‐blind (i.e., patients and researchers do not know if the patients are taking a drug or placebo), parallel study randomized 63 patients (mean age 55, ranging from 30 to 65 years old) with type 2 diabetes to take the GPR40 agonist MK‐8666 or a placebo for 14 days. MK-8666-treated patients had fasting blood glucose levels that were well below pre-treatment levels by the last treatment day. Placebo-treated patients showed no changes in their blood glucose levels. Among the MK-866-treated patients, 18 instances of mild to moderate drug‐related adverse events (i.e., pain in the back, neck, extremity, and/or abdomen; headache; constipation; nausea; and diarrhea) occurred. However, one patient developed elevations in the blood levels of three liver enzymes, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Elevations in these enzymes' blood levels suggest the presence of liver damage (see liver function tests). The patient continued to take MK-8666 for the 14 day treatment period; two weeks thereafter these enzymes returned to normal levels. The study concluded that this case may have reflected mild MK-8666-induced liver damage. The sponsor, Merck & Co., terminated further development of MK-8666 due to it having a possibly unfavorable risk–benefit ratio in type 2 diabetic patients. A study conducted in Japan on 1,222 adults with inadequately controlled (i.e. high blood sugar levels) type 2 diabetes were treated with the highly selective FFAR1 agonist TAK-875 in addition to their in-place treatment regimens for 1 year. Blood sugar levels improved 2 weeks after taking the drug and remained improved throughout the study. However, adverse events that emerged during treatment leading to discontinuance of TAK-875 varied between 2.9% and 9.2% depending on the patients' treatment regimens; the incidence of abnormal liver function tests during the trial varied between 0% and 5.8%, again depending on treatment regimens. Further development of TAK-875 was stopped due to concerns about its possible hepatotoxicity. A recent review of data from TAK-875 global clinical trials by an independent panel of experts overseeing the clinical development program also had concerns about liver safety. A simulated analysis of these studies suggested that this liver toxicity reflected the inhibition of liver bile acid transporters and mitochondrial electron transport chain enzymes by TAK-875 and its glycosylated metabolite, TAK-875-glucose. The results of these studies have been regarded as proof of the concept that FFAR1 contributes to the regulation of glucose levels in patients with type 2 diabetes and therefore is a potential target for treating these patients with FFAR1 agonists that do not have significant adverse effects such as hepatotoxicity. Recent preclinical studies are examining other FFAR1 agonists for their liver and other toxicities.
Taste
The main detectors and mediators of the five major taste perception elements viz., saltiness, sourness, bitterness, sweetness, and umami, are the cell-bound GPRs TAS1R2/TAS1R3, TAS1R1/TAS1R3, and multiple subtypes of TAS2R for sweetness, umami, and bitterness, respectively, and selective cell-bound ion channels for saltiness and sourness. However, studies indicate that the taste of substances sometimes involves more than one taste-detecting element. For example, taste of the artificial the sweetener saccharin appears to be detected by a combination of sweetness and bitterness elements. Cells bearing these taste receptors are on the tongue's upper surface, soft palate, upper esophagus, cheek, and epiglottis (see Taste buds). FFAR1 and FFAR4 appear to contribute to some types of taste perception in rodents. 1) Taste bud cells in the back of rodents' tongues express FFAR1 while cells in the epithelium of their tongues' circumvallate papillae express FFAR4. 2) Ffar1 and Ffar4 gene knockout mice had diminished taste responses to various fatty acids and a lower preference for consuming these fatty acids. 3) Ffar1 gene knockdown mice had a reduced intake and preference for sucrose in sucrose preference tests. 4) Human tongue taste bud cells contain FFAR4 but inconclusive studies suggest it may lack FFAR1. And 5) a selective activator of FFAR4, TUG-891, enhanced human's fatty orosensation (i.e., false sensation of taste obtained by tongue stimulation) when added to FFAR4-activating dietary fats but not when added to fat-free mineral oil. This finding suggests that in humans FFAR4 activation enhances but does not directly evoke a sensation of fats. Thus, FFAR1 and FFAR4 appear to mediate fatty acid taste perceptions and FFAR1 appears to mediate sweetness taste perception in rodents; taste bud FFAR4 but not FFAR1 appears to enhance the perception of fatty acids and fatty oils in humans. Further studies are needed to define the presence, locations, and precise roles of FFAR1 and FFAR4 in the various taste perceptions of animals and humans.
Central nervous system
FFAR1 is expressed on the neurons and some other cell types in the olfactory bulb, striatum, hippocampus, midbrain, hypothalamus, cerebellum, cerebral cortex, and caudate nucleus of the brain as well as in the spinal cord. FFAR1-activating fatty acids, particularly docosahexaenoic acid, are thought to play critical roles in neurons by maintaining their surface membrane integrity, survival, synaptic functions (synapses are specialize parts of neurons which communicate with other neurons), ion channel functions (e.g. communication between cells), and in suppressing the development of certain central nervous system disorders. However, it is often not clear that docosahexaenoic acid achieves these effects by activating FFAR1. The following studies have implicated FFAR1 in various central nervous system functions and/or disorders. 1) Ffar1 gene knockout mice showed abnormally reduced anxiety-like behavior in anxiety-inducing tasks compared to control mice. 2) Ffar1 gene knockout female mice had abnormally low anxiety responses, abnormally low locomotor activity, and impaired maternal care behavior (i.e., higher rates of offspring neglect and infanticide) compared to control female mice. 3) Obese, diabetic male C57BL6/J mice and db/db obese, diabetic mice (an animal disease model) have fear-associated learning and memory impairments as determined in various behavioral tests; GW5908 and docosahexaenoic acid reduced these impairments and GW1100 blocked docosahexaenoic acid's effects on learning and memory. 4) GW9508 completely restored the learning and memory of mice that had impaired learning and memory due to scopolamine treatment. 5) GW9508 reduced the cognitive deficits in A-beta AD mice (i.e. a mouse model of Alzheimer's disease); this reduction was blocked by treating the mice with GW1100. 6) GW9508 similarly improved learning and memory in A-beta AD mice evaluated with other cognition tests. And 7) the highly selective FFAR1 agonist TAK-875 reduced the cognitive impairments that occur in APPswe/PS1dE9 mice (another model of Alzheimer disease). These results suggest that FFAR1 may be, and should be evaluated as, a potentile target for the treatment of brain developmental, emotional, and mental impairments such as Alzheimer's disease.
Pain perception
Studies suggest that FFAR1 is involved in nociception, i.e., the perception of pain. 1) Oral administration of the FFAR1 agonist ZLY50 (which unlike most drugs crosses from the circulation into the central nervous systems' spinal fluid) reduced the pain responses of mice in three pain tests. 2) Injection of the FFAR1 agonist GW9508 into the spinal canal of rats decreased their pain response to spinal nerve ligation and heat; the pain-reducing action of GW9508 on spinal nerve ligation was blocked by the FFAR1 antagonist GW1100 but not the FFAR4 antagonist AH7614. 3) Ffar1 gene knockout mice as well as mice treated with the FFAR1 inhibitor GW1100 had enhanced pain responses in two pain tests. 4) And the intracerebroventricular injection (i.e., injection into a brain ventricle) of docosahexaenoic acid or GW9508 reduced the pain responses of mice to painful pressure on a paw and to radiant heat; their effects were blocked by intracerebroventricular injections of GW1100. These studies suggest that FFAR1 is involved in reducing rodent pain perception and recommend testing for its involvement in the perception of pain in humans.
Cancer
Many studies have suggested that FFAR1 alters the malignant behavior of some types of cultured cancer cells. These malignant behaviors include cultured cancer cell
motility and proliferation which are regarded as being related to the invasiveness and growth rate, respectively, of cancers in animals and humans. 1) GW9508, which activates FFAR1 but at higher concentrations also activates FFAR4, stimulated the motility of mouse LL/2 and rat RLCNR lung cancer cells; treatment of these cells with GW9508 plus GW1100 reduced these cells motility to levels below GW9508-treated and GW9508-untreated LL/2 and RLCNR cells. (In the presence of GW1100, GW9508 is assumed to act through FFAR4 but not FFAR1.) 2) GW9508 reduced the motility of A549 human lung cancer cells; GW9508 plus GW1100 treatment of these cells further reduced their motility; FFAR1 gene knockdown A549 cells showed less motility than control A549 cells; and GW9508-treated A549 FFAR1 gene knockdown cells had less motility than control or GW9508-treated cells. (GW9508 is assumed to act through FFAR4, not FFAR1, in FFAR1 gene knockdown or GW1100-treated cells.) 3) GW9508 did not alter the proliferation of LL/2, RLCNR, or A549 cells but in combination with GW1100 slightly decreased the proliferation of A549 but not LL/2 or RLCNR cells. These three sets of results suggest that FFAR1 enhances while FFAR4 inhibits the motility of LL/2, RLCNR, and A549 cells and that FFAR4 reduces A549 but not LL/2 or RLCNR cell proliferation. 4) Similar studies using the FFAR4 agonist TUG-891 and eicosapentaenoic acid in control and FFAR4 gene knockdown human DU145 and PC-3 prostate cancer cells suggested that FFA4 promotes these cells motility and proliferation. 5) GW9508 inhibited the motility of hamster pancreas cancer HPD1NR cells (which express FFAR1 but not FFAR4), stimulated the motility of hamster pancreas HPD2NR cancer cells (which express FFAR4 but not FFAR1), and slightly inhibited the motility of human PANC-1 pancreas cancer cells (which express FFAR1 and FFAR4). GW9508 markedly increased the motility of PANC-1 cells when they were also treated with GW1100. These results indicate that FFAR1 inhibits while FFA4 promotes motility in the three types of rodent pancreas cancer cells. And 6) studies in MG-63 human osteosarcoma (i.e. bone cancer) cells and the far more highly mobile MG63-R7 human osteosacromea cells suggest that FFAR1 inhibits and FFAR4 promotes motility. The latter three sets of results indicate that the roles of FFAR1 and FFAR4 in regulating cancer cell motility vary with the types of cancer cells studied.) Finally, studies in patients have shown that FFAR1 is overexpressed in some insulinomas (i.e. cancers derived from pancreas beta cells), in high grade and/or advanced stage ovarian cancers, and in high grade, advanced stage, and/or poor prognosis colorectal cancers. The overexpression of FFAR1 in these cancers suggests that it may play a role in their development and/or progression,
Breast cancer
FFAR1 and FFAR4 are expressed in human MDA-MB-231, MCF-7, and SK-BR-3 breast cancer cells and appear to regulate some of their and other types of breast cancer cells' malignant behaviors. 1) MDA-MB-231 cells that did not express FFAR1 (due to FFAR1 gene knockdown) or overexpressed FFRA1 (due to transfection with a FFAR1-producing plasmid) had lower and higher proliferation responses, respectively, to the FFAR1/FFAR4 activator, oleic acid, compared to control MDA-MB-231 cells. 2) T-47D human breast cancer cells (which express very low levels of FFAR4) and MCF-7 cells transfected with the FFAR-1-producing plasmid had increased proliferative responses to oleic acid compared to control cells. 3) The highly selective FFAR4 agonist TUG-891 reduced the proliferation of MCF-7 and MDA-MB-231 cells. 4) GW9508 increased the motility of FFAR4 knockdown MCF-7 and SK-BR-3 breast cancer cells compared to their respective control (i.e., FFAR4-expressing) MCF7 and SK-BR-3 cells. 5) GW9508 increased the development of lung tumors in nude mice injected with control MDA-MB-231 cells but did not do so in nude mice injected with FFAR4 knockdown MDA-MB-231 cells. These studies suggest that FFAR1 promotes the proliferation but inhibits the motility and FFAR4 promotes the motility and lung metastasis of human breast cancer cells. And 6) Clinical studies have reported that FFAR4 levels are higher in certain types of more aggressive human breast cancers and therefore may be a marker of disease severity and a target for treating these cancers (see FFAR4 in breast cancer). Similar studies on FFAR1 in human breast cancer are needed to determine its medical relevancy.
Tissue fibrosis
Recent studies suggest that FFAR1 is involved in pathological tissue fibrosis, i.e., the healing of tissue injury in which connective tissue replaces normal tissue leading to tissue remodeling, the formation of permanent scar tissue, and damaged organs. 1) Ffar1 gene knockout mice were protected from developing fibrotic kidneys in three models of this disease (unilateral obstruction of a single kidney's ureter, long-term kidney ischemia due to reducing blood flow to a single kidney, and adenine diet-induced chronic fibrotic kidney disease). 2) PBI-4050 (i.e., 3-pentylbenzeneacetic acid sodium salt), a FFAR1 agonist, blocked the development of fibrosis in rodent kidney, liver, heart, lung, pancreas, and skin models of pathological fibrosis. 3) In a model of non-alcoholic fatty liver disease. Ffar1 gene knockout mice developed less liver inflammation and fibrosis than control mice. And 4) topical application of GW5908 to small skin biopsy-like wounds (also termed punch wounds) in the skin of male mice increased the levels of type I collagen in the wound tissues; however it also decreased the size of these wounds and increased the speed with which the wounds healed. This last observation suggests that GW5908 can have positive as well as negative effects on the resolution of tissue injury. Note, however, that the role(s) of FFAR1 versus FFAR4 in the actions of GW9808 in this study was not defined. Overall, these studies suggest that FFAR1 may be a target for suppressing the development and/or progression of pathological tissue fibrosis.
See also
Free fatty acid receptor
Free fatty acid receptor 4
References
G protein-coupled receptors | Free fatty acid receptor 1 | [
"Chemistry"
] | 6,489 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,707 | https://en.wikipedia.org/wiki/GPR42 | Putative G-protein coupled receptor 42 (previously termed FFAR1L, FFAR3L, GPR41L, and GPR42P) is a protein that in humans is encoded by the GPR42 gene. The human GPR gene is located at the same site as the human FFAR1, FFAR, and FFAR3 genes, i.e., on the long (i.e., "q") arm of chromosome 19 at position 23.33 (notated as 19q23.33). This gene appears to be a segmental duplication of the FFAR3 gene. The human GPR42 gene codes for several proteins with a FFAR3-like structure but their expression in various cell types and tissues as well as their activities and functions have not yet been clearly defined in any scientific publication followed by PubMed as of 2023.
See also
Free fatty acid receptors
Free fatty acid receptor 3
References
Further reading
External links
G protein-coupled receptors | GPR42 | [
"Chemistry"
] | 205 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,836 | https://en.wikipedia.org/wiki/Hypocretin%20%28orexin%29%20receptor%201 | Orexin receptor type 1 (Ox1R or OX1), also known as hypocretin receptor type 1 (HcrtR1), is a protein that in humans is encoded by the HCRTR1 gene.
Function
The orexin 1 receptor (OX1), is a G-protein coupled receptor that is heavily expressed in projections from the lateral hypothalamus and is involved in the regulation of feeding behaviour. OX1 selectively binds the orexin-A neuropeptide. It shares 64% identity with OX2.
Ligands
Agonists
Orexin-A
Antagonists
RTIOX-276 - Selective OX1 antagonist
ACT-335827 - Selective OX1 antagonist
Almorexant - Dual OX1 and OX2 antagonist
Lemborexant - Dual OX1 and OX2 antagonist
Nemorexant - Dual OX1 and OX2 antagonist
SB-334,867 - Selective OX1 antagonist
SB-408,124 - Selective OX1 antagonist
SB-649,868 - Dual OX1 and OX2 antagonist
Suvorexant - Dual OX1 and OX2 antagonist
See also
Orexin receptor
References
External links
Further reading
G protein-coupled receptors | Hypocretin (orexin) receptor 1 | [
"Chemistry"
] | 249 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,427,846 | https://en.wikipedia.org/wiki/Hypocretin%20%28orexin%29%20receptor%202 | Orexin receptor type 2 (Ox2R or OX2), also known as hypocretin receptor type 2 (HcrtR2), is a protein that in humans is encoded by the HCRTR2 gene. It should not be confused for the protein CD200R1 which shares the alias OX2R but is a distinct, unrelated gene located on the human chromosome 3.
Structure
The structure of the receptor has been solved to 2.5 Å resolution as a fusion protein bound to suvorexant using lipid-mediated crystallization.
Function
OX2 is a G-protein coupled receptor expressed exclusively in the brain. It has 64% identity with OX1. OX2 binds both orexin A and orexin B neuropeptides. OX2 is involved in the central feedback mechanism that regulates feeding behaviour. Mice with enhanced OX2 signaling are resistant to high-fat diet-induced obesity.
This receptor is activated by Hipocretin, which is a wake-promoting hypothalamic neuropeptide that acts as a critical regulator of sleep in animals as Zebrafish or Mammals. This protein has mutations in Astyanax mexicanus that reduces the sleep needs of the cavefish.
Ligands
Agonists
Danavorexton (TAK-925) – selective OX2 receptor agonist
Firazorexton – selective OX2 receptor agonist
Orexins – dual OX1 and OX2 receptor agonists
Orexin-A – approximately equipotent at the OX1 and OX2 receptors
Orexin-B – approximately 5- to 10-fold selectivity for the OX2 receptor over the OX1 receptor
Oveporexton
SB-668875 – selective OX2 receptor agonist
Suntinorexton – selective OX2 receptor agonist
TAK-861 – selective OX2 receptor agonist
Antagonists
Almorexant - Dual OX1 and OX2 antagonist
Daridorexant (nemorexant) - Dual OX1 and OX2 antagonist
EMPA - Selective OX2 antagonist
Filorexant - Dual OX1 and OX2 antagonist
JNJ-10397049 (600x selective for OX2 over OX1)
Lemborexant - Dual OX1 and OX2 antagonist
MK-1064 - Selective OX2 antagonist
MK-8133 - Selective OX2 antagonist
SB-649,868 - Dual OX1 and OX2 antagonist
Seltorexant - Selective OX2 antagonist
Suvorexant - Dual OX1 and OX2 antagonist
TCS-OX2-29 - Selective OX2 antagonist
(3,4-dimethoxyphenoxy)alkylamino acetamides
Compound 1m - Selective OX2 antagonist
See also
Orexin receptor
References
Further reading
G protein-coupled receptors | Hypocretin (orexin) receptor 2 | [
"Chemistry"
] | 572 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,025 | https://en.wikipedia.org/wiki/Nylatron | Nylatron is a tradename for a family of nylon plastics, typically filled with molybdenum disulfide lubricant powder. It is used to cast plastic parts for machines, because of its mechanical properties and wear-resistance.
Nylatron is a brand name of Mitsubishi Chemical Advanced Materials, Inc. and was originally developed and manufactured by Nippon Polypenco Limited.
Nylatron is used in several applications such as:
rotary lever actuators where unusual shapes are required
heavy-duty caster wheels, normally as a replacement for cast iron or forged steel
plain bearing material, especially in screw conveyor applications
References
External links
Matweb datasheets
Nylatron Plastic Material Datasheets
Polymers | Nylatron | [
"Chemistry",
"Materials_science"
] | 149 | [
"Polymer stubs",
"Polymers",
"Organic chemistry stubs",
"Polymer chemistry"
] |
14,428,048 | https://en.wikipedia.org/wiki/Melanocortin%203%20receptor | Melanocortin 3 receptor (MC3R) is a protein that in humans is encoded by the gene.
Function
This gene encodes MC3R, a G-protein coupled receptor (GPCR) for melanocyte-stimulating hormone (MSH) and adrenocorticotropic hormone (ACTH) that is expressed in the brain. This gene maps to the same region as the locus for benign neonatal epilepsy. Mice deficient for this gene have increased fat mass, reduced lean mass and decreased food intake, all suggesting a role for the receptor in the regulation of energy homeostasis. MC3R mutations has been linked to reduced growth rate during childhood and a delay in the age of puberty onset.
Research
Studies performed by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), found that two specific polymorphisms in the MC3R gene may be associated with pediatric obesity and greater body mass because of greater energy intake. Children who were homozygous for C17A + G241A consumed approximately 38% more than those who did not contain aforementioned polymorphisms. The study concluded that these genetic variants did not affect energy expenditure.
Ligands
Ac-Val-Gln-(pI)DPhe-DTic-NH2, first MC3 selective agonist, 100x selectivity over MC4.
Ac-Val-Gln-DBip-DTic-NH2, 140x selectivity over MC4.
Pyrrolidine bis-cyclic guanidines, non-peptide small molecule MC3 agonists, good selectivity over MC4 but not over MC1 or MC5.
SHU-9119, mixed MC3/MC4 antagonist.
Evolution
Paralogue
Source:
MC5R
MC4R
MC1R
MC2R
LPAR1
S1PR2
GPR12
S1PR1
GPR6
LPAR2
S1PR3
GPR3
GPR119
CNR1
LPAR3
S1PR5
S1PR4
CNR2
See also
Melanocortin receptor
References
Further reading
External links
G protein-coupled receptors
Human proteins | Melanocortin 3 receptor | [
"Chemistry"
] | 447 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,063 | https://en.wikipedia.org/wiki/Melanocortin%205%20receptor | Melanocortin 5 receptor (MC5R) is a protein that in humans is encoded by the gene. It is located on the chromosome 18 in the human genome. When the MC5R was disrupted in transgenic mice, it induced disruption of their exocrine glands and resulted in decreased production of sebum.
Physiology
MC5R is necessary for normal sebum production. Stimulation of MC5R promotes fatty acid oxidation in skeletal muscle and lypolysis in adipocytes. MC5R is essential for erythrocyte differentiation. MC5R is involved in inflammation. MC5R helps maintain thermal homeostasis.
MC5R is expressed in the brain at different levels depending on physical activity.
Pheromones
MC5R is heavily expressed in the preputial gland in mice (a modified sebaceous gland involved in pheromone production). MC5R deficiency in male mice decreases aggressive behavior, promotes defensive behavior and encourages other male mice to attack MC5R-deficient males through pheromonal signals.
MRAP
Melanocortin 2 receptor accessory protein (MRAP) traps MC5R protein inside cells.
Evolution
Paralogues
Source:
MC4R
MC3R
MC1R
MC2R
S1PR1
LPAR1
S1PR3
GPR12
LPAR2
GPR3
S1PR2
GPR6
GPR119
LPAR3
CNR1
S1PR5
S1PR4
CNR2
See also
Melanocortin receptor
References
Further reading
External links
G protein-coupled receptors
Human proteins | Melanocortin 5 receptor | [
"Chemistry"
] | 327 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,076 | https://en.wikipedia.org/wiki/Melatonin%20receptor%201A | Melatonin receptor type 1A is a protein that in humans is encoded by the MTNR1A gene.
Function
This gene encodes the MT1 protein, one of two high-affinity forms of a receptor for melatonin, the primary hormone secreted by the pineal gland. This receptor is a G protein-coupled, 7-transmembrane receptor that is responsible for melatonin effects on mammalian circadian rhythm and reproductive alterations affected by day length. The receptor is an integral membrane protein that is readily detectable and localized to two specific regions of the brain. The hypothalamic suprachiasmatic nucleus appears to be involved in circadian rhythm while the hypophysial pars tuberalis may be responsible for the reproductive effects of melatonin.
Ligands
Melatonin – full agonist
Afobazole – agonist
Agomelatine – agonist
See also
Melatonin receptor
Discovery and development of melatonin receptor agonists
References
Further reading
G protein-coupled receptors
Human proteins
1A | Melatonin receptor 1A | [
"Chemistry"
] | 215 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,123 | https://en.wikipedia.org/wiki/Neuropeptide%20Y%20receptor%20Y1 | Neuropeptide Y receptor type 1 is a protein that in humans is encoded by the NPY1R gene.
Selective ligands
Agonists
Neuropeptide Y (endogenous agonist, non subtype selective)
Peptide YY
Antagonists
Peptide
BVD-10 (selective NPY1 antagonist, CAS# 262418-00-8)
GR-231,118 (mixed NPY1 antagonist / NPY4 agonist, CAS# 158859-98-4)
Non-peptide
BIBO-3304 (CAS# 191868-14-1)
BIBP-3226 (CAS# 159013-54-4)
PD-160,170 (CAS# 181468-88-2)
Available Structures
5ZBH (Neuropeptide Y1 bound to antagonist BMS-193835)
5ZBQ (Neuropeptide Y1 bound to antagonist UR-MK299)
See also
Neuropeptide Y receptor
References
Further reading
External links
G protein-coupled receptors | Neuropeptide Y receptor Y1 | [
"Chemistry"
] | 220 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,143 | https://en.wikipedia.org/wiki/Neuropeptide%20Y%20receptor%20Y2 | Neuropeptide Y receptor type 2 (Y2R) is a member of the neuropeptide Y receptor family of G-protein coupled receptors, that in humans is encoded by the NPY2R gene.
Selective ligands
Agonists
Neuropeptide Y (endogenous agonist, non subtype selective)
Neuropeptide Y fragment 13-36 (NPY2 selective agonist)
Peptide YY
Peptide YY 3-36 fragment
Antagonists
BIIE-0246 (CAS# 246146-55-4)
JNJ 5207787 (CAS# 683746-68-1)
SF 11 (CAS# 443292-81-7)
See also
Neuropeptide Y receptor
References
External links
Further reading
G protein-coupled receptors | Neuropeptide Y receptor Y2 | [
"Chemistry"
] | 171 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,150 | https://en.wikipedia.org/wiki/Neuropeptide%20Y%20receptor%20Y6 | Putative neuropeptide Y receptor type 6 is a protein that in humans is encoded by the NPY6R gene.
References
Further reading | Neuropeptide Y receptor Y6 | [
"Chemistry"
] | 32 | [
"Biochemistry stubs",
"Protein stubs"
] |
14,428,167 | https://en.wikipedia.org/wiki/Neuropeptide%20Y%20receptor%20Y5 | Neuropeptide Y receptor type 5 is a protein that in humans is encoded by the NPY5R gene.
Selective ligands
Agonists
Neuropeptide Y (endogenous agonist, non subtype selective)
BWX-46 (selective NPY5 agonist, CAS# 172997-92-1)
Peptide YY
Antagonists
CGP-71683 (CAS# 192322-50-2)
FMS-586
L-152,804 (CAS# 6508-43-6)
Lu AA-33810
MK-0557
NTNCB (CAS# 486453-65-0)
Velneperit (S-2367)
See also
Neuropeptide Y receptor
References
Further reading
External links
G protein-coupled receptors | Neuropeptide Y receptor Y5 | [
"Chemistry"
] | 170 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,201 | https://en.wikipedia.org/wiki/GPR143 | G-protein coupled receptor 143, also known as Ocular albinism type 1 (OA1) in humans, is a conserved integral membrane protein with seven transmembrane domains and similarities with G protein-coupled receptors (GPCRs) that is expressed in the eye and epidermal melanocytes. This protein encoded by the GPR143 gene, whose variants can lead to Ocular albinism type 1.
The GPR143 gene is regulated by the Microphthalmia-associated transcription factor.
L-DOPA is an endogenous ligand for OA1.
Interactions
GPR143 has been shown to interact with GNAI1.
References
Further reading
External links
GeneReviews/NCBI/NIH/UW entry on Ocular Albinism, X-Linked
G protein-coupled receptors | GPR143 | [
"Chemistry"
] | 172 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,361 | https://en.wikipedia.org/wiki/P2RY6 | P2Y purinoceptor 6 is a protein that in humans is encoded by the P2RY6 gene.
Function
The product of this gene, P2Y6, belongs to the family of G-protein coupled receptors. This family has several receptor subtypes with different pharmacological selectivity, which overlaps in some cases, for various adenosine and uridine nucleotides. This receptor is responsive to UDP, partially responsive to UTP and ADP, and not responsive to ATP. Four transcript variants encoding the same isoform have been identified for this gene.
See also
P2Y receptor
References
Further reading
External links
G protein-coupled receptors | P2RY6 | [
"Chemistry"
] | 142 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,372 | https://en.wikipedia.org/wiki/P2RY11 | P2Y purinoceptor 11 is a protein that in humans is encoded by the P2RY11 gene.
The product of this gene, P2Y11, belongs to the family of G-protein coupled receptors. This family has several receptor subtypes with different pharmacological selectivity, which overlaps in some cases, for various adenosine and uridine nucleotides. This receptor is coupled to the stimulation of the phosphoinositide and adenylyl cyclase pathways and behaves as a selective purinoceptor. Naturally occurring read-through transcripts, resulting from intergenic splicing between this gene and an immediately upstream gene (PPAN, encoding peter pan homolog), have been found. The PPAN-P2RY11 read-through mRNA is ubiquitously expressed and encodes a fusion protein that shares identity with each individual gene product.
See also
P2Y receptor
References
Further reading
External links
G protein-coupled receptors | P2RY11 | [
"Chemistry"
] | 208 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,511 | https://en.wikipedia.org/wiki/Parathyroid%20hormone%202%20receptor | Parathyroid hormone 2 receptor is a protein that in humans is encoded by the PTH2R gene.
Function
The protein encoded by this gene is a member of the G protein-coupled receptor family 2. This protein is a receptor for parathyroid hormone (PTH). This receptor is more selective in ligand recognition and has a more specific tissue distribution compared to parathyroid hormone 1 receptor (PTH1R). It is activated by PTH but not by parathyroid hormone-like hormone (PTHLH) and is particularly abundant in the brain and pancreas.
The molecular interaction of the PTH2 receptor with the peptide TIP39 has been characterized in full 3D molecular detail, identifying among other residues Tyr-318 in transmembrane helix 5 as a key residue for high affinity binding.
Mechanism
It is a member of the secretin family of G protein-coupled receptors. The activity of this receptor is mediated by Gs protein, which activates adenylyl cyclase.
See also
Parathyroid hormone receptor
References
Further reading
External links
G protein-coupled receptors | Parathyroid hormone 2 receptor | [
"Chemistry"
] | 224 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,577 | https://en.wikipedia.org/wiki/Somatostatin%20receptor%201 | Somatostatin receptor type 1 is a protein that in humans is encoded by the SSTR1 gene.
Function
Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biological effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. The encoded protein is a member of the superfamily of somatostatin receptors having seven transmembrane segments, and is expressed in highest levels in jejunum and stomach.
See also
Somatostatin receptor
References
Further reading
External links
G protein-coupled receptors | Somatostatin receptor 1 | [
"Chemistry"
] | 129 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,595 | https://en.wikipedia.org/wiki/Somatostatin%20receptor%203 | Shekel Somatostatin receptor type 3 is a protein that in humans is encoded by the SSTR3 gene.
Function
Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biological effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SSTR3 is a member of the superfamily of receptors having seven transmembrane segments and is expressed in highest levels in brain and pancreatic islets. SSTR3 is functionally coupled to adenylyl cyclase.
See also
Somatostatin receptor
References
Further reading
External links
G protein-coupled receptors | Somatostatin receptor 3 | [
"Chemistry"
] | 143 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,609 | https://en.wikipedia.org/wiki/Somatostatin%20receptor%204 | Somatostatin receptor type 4 is a protein that in humans is encoded by the SSTR4 gene.
Function
Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biologic effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SSTR4 is a member of the superfamily of receptors having seven transmembrane segments and is expressed in highest levels in fetal and adult brain and lung.
See also
Somatostatin receptor
References
Further reading
External links
G protein-coupled receptors | Somatostatin receptor 4 | [
"Chemistry"
] | 126 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,627 | https://en.wikipedia.org/wiki/Tachykinin%20receptor%202 | Substance-K receptor is a protein that in humans is encoded by the TACR2 gene.
Function
This gene belongs to a family of genes that function as receptors for tachykinins. Receptor affinities are specified by variations in the 5'-end of the sequence. The receptors belonging to this family are characterized by interactions with G proteins and 7 hydrophobic transmembrane regions. This gene encodes the receptor for the tachykinin neuropeptide substance K, also referred to as neurokinin A.
Selective Ligands
Several selective ligands for NK2 are now available, and although most of the compounds developed so far are peptides, one small-molecule antagonist Saredutant is currently in clinical trials as an anxiolytic and antidepressant.
Agonists
GR-64349 - potent and selective agonist, EC50 3.7nM, 7-amino acid polypeptide chain. CAS# 137593-52-3
Antagonists
Ibodutant - failed its Phase 3 trial for IBS treatment in 2015, and abandoned by Menarini
Saredutant - mixed but mostly negative Phase 3 trial results in 2009, and abandoned by Sanofi-Aventis
GR-159897
MEN-10376 - potent and selective antagonist, 7-amino acid polypeptide chain. CAS# 135306-85-3
See also
Tachykinin receptor
References
Further reading
External links
G protein-coupled receptors | Tachykinin receptor 2 | [
"Chemistry"
] | 310 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,638 | https://en.wikipedia.org/wiki/Tachykinin%20receptor%203 | Tachykinin receptor 3, also known as TACR3, is a protein which in humans is encoded by the TACR3 gene.
Function
This gene belongs to a family of genes that function as receptors for tachykinins. Receptor affinities are specified by variations in the 5'-end of the sequence. The receptors belonging to this family are characterized by interactions with G proteins and 7 hydrophobic transmembrane regions. This gene encodes the receptor for the tachykinin neurokinin 3, also referred to as neurokinin B.
Selective ligands
A number of selective ligands are available for NK3. NK3 receptor antagonists are being investigated as treatments for various indications.
Agonists
Neurokinin B – endogenous peptide ligand, also interacts with other neurokinin receptors but has highest affinity for NK3
Senktide – 7-amino acid polypeptide, NK3 selective, CAS# 106128-89-6
Antagonists
Elinzanetant (BAY-3427080 GSK-1144814, NT-814)
Fezolinetant (ESN-364)
Osanetant (SR-142,801)
Pavinetant (MLE-4901, AZD-4901, AZD-2624)
Talnetant (SB-223,412)
SB-222,200 – potent and selective antagonist, Ki = 4.4 nM, 3-Methyl-2-phenyl-N-[(1S)-1-phenylpropyl]-4-quinolinecarboxamide, CAS# 174635-69-9
SB-218,795 – more selective than SB-222,200, Ki = 13 nM, (R)-[(2-Phenyl-4-quinolinylcarbonyl)amino]-methyl ester benzeneacetic acid, CAS# 174635-53-1
See also
Tachykinin receptor
References
Further reading
External links
G protein-coupled receptors | Tachykinin receptor 3 | [
"Chemistry"
] | 431 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,702 | https://en.wikipedia.org/wiki/VIPR2 | Vasoactive intestinal peptide receptor 2 also known as VPAC2, is a G-protein coupled receptor that in humans is encoded by the VIPR2 gene.
Tissue distribution
VIPR2 is expressed in the uterus, prostate, smooth muscle of the gastrointestinal tract, seminal vesicles and skin, blood vessels and thymus. VIPR2 is also expressed in the cerebellum.
Function
Vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP) are homologous peptides that function as neurotransmitters and neuroendocrine hormones. While the receptors for VIP (VIRP 1 and 2) and PACAP (ADCYAP1R1) share homology, they differ in their substrate specificities and expression patterns. VIPR2 transduction results in upregulation of adenylate cyclase activity. Furthermore, VIPR2 mediates the anti-inflammatory effects of VIP.
Research using VPAC2 knockout mice implicate it in the function of the circadian clock, growth, basal energy expenditure and male reproduction.
VIPR2 and/or PAC1 receptor activation is involved in cutaneous active vasodilation in humans.
Splice variants may modify the immunoregulatory contributions of the VIP-VIPR2 axis.
VIPR2 may contribute to autoregulation and/or coupling within the suprachiasmatic nucleus (SCN) core and to control of the SCN shell.
Clinical significance
VIPR2 may play a role in schizophrenia.
The abnormal expression of VIPR2 messenger RNA in gallbladder tissue may play a role in the formation of gall stones and polyps.
See also
Vasoactive intestinal peptide receptor
VIPR1
References
Further reading
External links
G protein-coupled receptors | VIPR2 | [
"Chemistry"
] | 383 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,722 | https://en.wikipedia.org/wiki/Frizzled-5 | Frizzled-5 (Fz-5) is a protein that in humans is encoded by the FZD5 gene.
Members of the 'frizzled' gene family encode 7-transmembrane domain proteins that are receptors for Wnt signaling proteins. Fz-5 is believed to be the receptor for the Wnt5A ligand.
References
Further reading
External links
G protein-coupled receptors | Frizzled-5 | [
"Chemistry"
] | 87 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,754 | https://en.wikipedia.org/wiki/Frizzled-3 | Frizzled-3 (Fz-3) is a protein that in humans is encoded by the FZD3 gene.
Function
This gene is a member of the frizzled gene family. Members of this family encode seven-transmembrane domain proteins that are receptors for the Wingless type MMTV integration site family of signaling proteins. Most frizzled receptors are coupled to the beta-catenin canonical signaling pathway. It may play a role in mammalian hair follicle development.
The function of this gene is largely derived from mouse studies. Fzd3 in the mouse functions through planar cell polarity signaling instead of the canonical Wnt/beta-catenin pathway. Fzd3 controls axon growth and guidance in the mouse nervous system, and migration of neural crest cells.
See also
Frizzled
References
Further reading
External links
G protein-coupled receptors | Frizzled-3 | [
"Chemistry"
] | 185 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,770 | https://en.wikipedia.org/wiki/GPR68 | Ovarian cancer G-protein coupled receptor 1 is a protein that in humans is encoded by the GPR68 gene.
See also
Proton-sensing G protein-coupled receptors
References
Further reading
G protein-coupled receptors | GPR68 | [
"Chemistry"
] | 46 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,782 | https://en.wikipedia.org/wiki/Frizzled-1 | Frizzled-1 (Fz-1) is a protein that in humans is encoded by the FZD1 gene.
Function
Members of the 'frizzled' gene family encode 7-transmembrane domain proteins that are receptors for Wnt signaling proteins. The FZD1 protein contains a signal peptide, a cysteine-rich domain in the N-terminal extracellular region, 7 transmembrane domains, and a C-terminal PDZ domain-binding motif. The FZD1 transcript is expressed in various tissues.
References
Further reading
External links
G protein-coupled receptors | Frizzled-1 | [
"Chemistry"
] | 126 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,801 | https://en.wikipedia.org/wiki/Frizzled-6 | Frizzled-6 (Fz-6) is a protein that in humans is encoded by the FZD6 gene.
Members of the 'frizzled' gene family encode 7-transmembrane domain proteins that are receptors for WNT signaling proteins. The FZD6 protein contains a signal peptide, a cysteine-rich domain in the N-terminal extracellular region, and 7 transmembrane domains. However, unlike many other FZD family members, FDZ6 does not contain a C-terminal PDZ domain-binding motif. Fz-6 is believed to be the receptor for the WNT4 ligand.
Interactions
Fz-6 has been shown to interact with secreted frizzled-related protein 1.
References
Further reading
External links
G protein-coupled receptors | Frizzled-6 | [
"Chemistry"
] | 170 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,834 | https://en.wikipedia.org/wiki/Frizzled-7 | Frizzled-7 (Fd-7) is a protein that in humans is encoded by the FZD7 gene.
Members of the 'frizzled' gene family encode 7-transmembrane domain proteins that are receptors for Wnt signaling proteins. The FZD7 protein contains an N-terminal signal sequence, 10 cysteine residues typical of the cysteine-rich extracellular domain of Fz family members, 7 putative transmembrane domains, and an intracellular C-terminal tail with a PDZ domain-binding motif. FZD7 gene expression may downregulate APC function and enhance beta-catenin-mediated signals in poorly differentiated human esophageal carcinomas.
Interactions
Fz-7 has been shown to interact with DLG4.
References
Further reading
External links
G protein-coupled receptors | Frizzled-7 | [
"Chemistry"
] | 181 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,848 | https://en.wikipedia.org/wiki/Frizzled-8 | Frizzled-8 (Fz-8) is a protein that in humans is encoded by the FZD8 gene.
Function
This intronless gene is a member of the frizzled gene family. Members of this family encode seven-transmembrane domain proteins that are receptors for the Wingless type MMTV integration site family of signaling proteins. Most frizzled receptors are coupled to the beta-catenin canonical signaling pathway. This gene is highly expressed in two human cancer cell lines, indicating that it may play a role in several types of cancer. The crystal structure of the extracellular cysteine-rich domain of a similar mouse protein has been determined.
References
Further reading
External links
G protein-coupled receptors | Frizzled-8 | [
"Chemistry"
] | 154 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,861 | https://en.wikipedia.org/wiki/Frizzled-9 | Frizzled-9 (Fz-9) is a protein that in humans is encoded by the FZD9 gene. Fz-9 has also been designated as CD349 (cluster of differentiation 349).
Function
Members of the 'frizzled' gene family encode 7-transmembrane domain proteins that are receptors for Wnt signaling proteins. The FZD9 gene is located within the Williams syndrome common deletion region of chromosome 7, and heterozygous deletion of the FZD9 gene may contribute to the Williams syndrome phenotype. FZD9 is expressed predominantly in brain, testis, eye, skeletal muscle, and kidney.
References
Further reading
External links
Clusters of differentiation
G protein-coupled receptors | Frizzled-9 | [
"Chemistry"
] | 158 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,925 | https://en.wikipedia.org/wiki/GPR65 | Psychosine receptor is a G protein-coupled receptor (GPCR) protein that in humans is encoded by the GPR65 gene. GPR65 is also referred to as TDAG8.
Species, tissue, and subcellular distribution
GPR65 (TDAG8) is primarily expressed in lymphoid tissues (spleen, lymph nodes, thymus, and leukocytes), and as a GPCR, the protein is localized to the plasma membrane.
Function
Ligand binding
In 2001, GPR65 was reported to be a specific receptor for psychosine (d-galactosyl-β-1,1′ sphingosine) as well as several other related glycosphingolipids. However, the specific binding of psychosine to GPR65 has been contested as the reported ligand binding did not satisfy the appropriate pharmacological criteria.
More recently, 3-[(2,4-dichlorophenyl)methylsulfanyl]-1,6-dimethylpyridazino[4,5-e][1,3,4]thiadiazin-5-one (referred to as BTB09089) was found to be a specific agonist for GPR65. Furthermore, [(S)-phenyl(pyridin-4-yl)methyl] 4-methyl-2-pyrimidin-2-yl-1,3-thiazole-5-carboxylate (referred to as ZINC62678696) was found to act as a BTB09089 negative allosteric modulator.
pH sensing
GPR65 senses extracellular pH. Levels of cyclic adenosine monophosphate (cAMP), a secondary messenger associated with activation of GPCRs in the cAMP-dependent pathway, were found to be elevated in neutral to acidic extracellular pH (pH 7.0-6.5) in cells expressing GPR65. In cells with mutated GPR65, this pH-sensing effect was reduced or eliminated. In the presence of psychosine, however, the levels of cAMP increased at a shifted, more acidic pH range. As such, psychosine displayed an inhibitory effect as an antagonist when GPR65 was stimulated with an increasing concentration of protons (increasingly acidic pH). This finding directly contested the previous reporting of psychosine as an activating ligand for GPR65.
The pH-sensing ability of GPR65 was further tested and confirmed, as it was found that cAMP levels increased when GPR65 was stimulated by pH values less than pH 7.2.
GPR65 senses pH by protonation of histidine residues on its extracellular domain, and when activated, GPR65 enables the downstream signaling through the Gq/11, Gs, and G12/13 pathways. The ability of GPR65 to sense pH can modulate several cellular functions in various biological systems including the immune, cardiovascular, respiratory, renal, and nervous systems.
GPR65's ability to sense pH plays a prominent role in tumor development. GPR65 is highly expressed in a variety of human tumors. Tumor development is associated with low extracellular pH due to changes in metabolism of rapidly dividing cells. GPR65 enables tumor growth by sensing the acidic environment. It was found that overexpression of GPR65 prevents tumor cell death in acidic conditions in vitro and facilitates tumor growth in vivo.
Immune
GPR65 reduces immune-mediated inflammation by regulating cytokine production of T cells (including IL-6, TNF-α and IL-1β) and macrophages.
Cardiovascular
After myocardial infarction, anaerobic respiration and severe inflammation occurs—both of which are accompanied by an acidic environment. GPR65 knockout mice showed a decline in survival and cardiac function after myocardial infarction, which indicates that GPR65-mediated pH sensing is physiologically relevant. GPR65 exhibits a cardioprotective effect against myocardial infarction by reducing CCL20 expression and the migration of IL-17A-producing γδT cells that express CCR6, a receptor for CCL20.
Visual
Retinal function is sensitive to changes in pH. It was found that GPR65 is overexpressed in the retina of mouse models of retinal degeneration and that the receptor supports the survival of photoreceptors in a degenerating retina by sensing pH and activating microglia after light-injury.
Gastrointestinal
Vagal afferents expressing GPR65 innervate intestinal villi. These GPR65-expressing vagal afferents detect nutrients in the intestinal lumen and also slow gut motility.
Depression
GPR65 was identified as a potential target linking inflammation and depression. GPR65 knockout mice exhibited a significant reduction in mobility in a forced swim test as well as higher consumption of sucrose—both of which are behaviors associated with depression.
History/Discovery
In 1996, Choi et al. first identified GPR65 (TDAG8) as a G protein-coupled receptor whose expression was induced during activation-induced apoptosis of T cells. The group sought to identify which genes were necessary during T cell receptor-mediated death of immature thymocytes, and using differential mRNA display, they found that TDAG8 expression was induced upon activation of T cells. Because this gene was found to be associated with T-cell death (apoptosis), it was named TDAG8, or T Cell Death Associated Gene 8.
See also
Proton-sensing G protein-coupled receptors
References
Further reading
G protein-coupled receptors | GPR65 | [
"Chemistry"
] | 1,184 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,933 | https://en.wikipedia.org/wiki/Galanin%20receptor%203 | Galanin receptor 3 (GAL3) is a G-protein coupled receptor encoded by the GALR3 gene.
Function
The neuropeptide galanin modulates a variety of physiologic processes including cognition/memory, sensory/pain processing, hormone secretion, and feeding behavior. The human galanin receptors are G protein-coupled receptors that functionally couple to their intracellular effector through distinct signaling pathways. GALR3 is found in many tissues and may be expressed as 1.4-, 2.4-, and 5-kb transcripts
See also
Galanin receptor
References
Further reading
External links
G protein-coupled receptors | Galanin receptor 3 | [
"Chemistry"
] | 133 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,969 | https://en.wikipedia.org/wiki/S1PR4 | Sphingosine-1-phosphate receptor 4 also known as S1PR4 is a human gene which encodes a G protein-coupled receptor which binds the lipid signaling molecule sphingosine 1-phosphate (S1P). Hence this receptor is also known as S1P4.
Function
This gene is a member of the endothelial differentiation, G-protein-coupled (EDG) receptor gene family. EDG receptors bind lysophospholipids or lysosphingolipids as ligands, and are involved in cell signalling in many different cell types. This EDG receptor gene is intronless and is specifically expressed in the lymphoid tissue.
Evolution
Paralogues to S1PR4 Gene
S1PR5
S1PR3
S1PR1
S1PR2
LPAR2
LPAR1
LPAR3
CNR1
GPR6
CNR2
GPR3
GPR12
MC4R
MC5R
MC3R
MC2R
MC1R
GPR119
See also
Lysophospholipid receptor
References
Further reading
External links
G protein-coupled receptors | S1PR4 | [
"Chemistry"
] | 236 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,986 | https://en.wikipedia.org/wiki/Galanin%20receptor%202 | Galanin receptor 2, (GAL2) is a G-protein coupled receptor encoded by the GALR2 gene.
Function
Galanin is an important neuromodulator present in the brain, gastrointestinal system, and hypothalamopituitary axis. It is a 30-amino acid non-C-terminally amidated peptide that potently stimulates growth hormone secretion, inhibits cardiac vagal slowing of heart rate, abolishes sinus arrhythmia, and inhibits postprandial gastrointestinal motility. The actions of galanin are mediated through interaction with specific membrane receptors that are members of the 7-transmembrane family of G protein-coupled receptors. GALR2 interacts with the N-terminal residues of the galanin peptide. The primary signaling mechanism for GALR2 is through the phospholipase C/protein kinase C pathway (via Gq), in contrast to GALR1, which communicates its intracellular signal by inhibition of adenylyl cyclase through Gi. However, it has been demonstrated that GALR2 couples efficiently to both the Gq and Gi proteins to simultaneously activate 2 independent signal transduction pathways.
See also
Galanin receptor
References
Further reading
External links
G protein-coupled receptors | Galanin receptor 2 | [
"Chemistry"
] | 270 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,993 | https://en.wikipedia.org/wiki/Hydroxycarboxylic%20acid%20receptor%203 | Hydroxycarboxylic acid receptor 3 (HCA3), also known as niacin receptor 2 (NIACR2) and GPR109B, is a protein which in humans is encoded by the HCAR3 gene. HCA3, like the other hydroxycarboxylic acid receptors HCA1 and HCA2, is a G protein-coupled receptor (GPCR). The primary endogenous agonists of HCA3 are 3-hydroxyoctanoic acid and kynurenic acid. HCA3 is also a low-affinity biomolecular target for niacin (aka nicotinic acid).
References
Further reading
External links
G protein-coupled receptors | Hydroxycarboxylic acid receptor 3 | [
"Chemistry"
] | 151 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,428,999 | https://en.wikipedia.org/wiki/F2RL3 | Protease-activated receptor 4 (PAR-4), also known as coagulation factor II (thrombin) receptor-like 3, is a protein that in humans is encoded by the F2RL3 gene.
Function
Coagulation factor II (thrombin) receptor-like 3 (F2RL3) is a member of the large family of 7-transmembrane-region receptors that couple to guanosine-nucleotide-binding proteins. F2RL3 is also a member of the protease-activated receptor family. F2RL3 is activated by proteolytic cleavage of its extracellular amino terminus. The new amino terminus functions as a tethered ligand and activates the receptor. F2RL3 is activated by thrombin and trypsin.
See also
Protease-activated receptor
References
Further reading
Receptors
G protein-coupled receptors | F2RL3 | [
"Chemistry"
] | 188 | [
"G protein-coupled receptors",
"Receptors",
"Signal transduction"
] |
14,429,020 | https://en.wikipedia.org/wiki/LPAR2 | Lysophosphatidic acid receptor 2 also known as LPA2 is a protein that in humans is encoded by the LPAR2 gene. LPA2 is a G protein-coupled receptor that binds the lipid signaling molecule lysophosphatidic acid (LPA).
Function
This gene encodes a member of family I of the G protein-coupled receptors, as well as the EDG family of proteins. This protein functions as a lysophosphatidic acid (LPA) receptor and contributes to Ca2+ mobilization, a critical cellular response to LPA in cells, through association with Gi and Gq proteins.
Interactions
LPAR2 has been shown to interact with TRIP6.
Evolution
Paralogues
Source:
LPAR1
LPAR3
S1PR1
S1PR5
S1PR4
S1PR2
S1PR3
GPR6
GPR3
GPR12
MC4R
MC5R
CNR1
MC3R
CNR2
MC1R
GPR119
MC2R
See also
Lysophospholipid receptor
References
Further reading
External links
G protein-coupled receptors | LPAR2 | [
"Chemistry"
] | 235 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,033 | https://en.wikipedia.org/wiki/GPR37L1 | Endothelin B receptor-like protein 2 is a protein that in humans is encoded by the GPR37L1 gene.
References
Further reading
G protein-coupled receptors | GPR37L1 | [
"Chemistry"
] | 36 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,047 | https://en.wikipedia.org/wiki/TAAR2 | Trace amine-associated receptor 2 (TAAR2), formerly known as G protein-coupled receptor 58 (GPR58), is a protein that in humans is encoded by the TAAR2 gene. TAAR2 is co-expressed with Gα proteins; however, its signal transduction mechanisms have not been determined.
Tissue distribution
Human TAAR2 (hTAAR2) is expressed in the cerebellum, olfactory sensory neurons in the olfactory epithelium, and leukocytes (i.e., white blood cells), among other tissues. hTAAR1 and hTAAR2 are both required for white blood cell activation by trace amines in granulocytes.
Using brain histochemistry staining of mice with LacZ insertion into TAAR2 gene histochemical reaction was found in the glomerular layer of the olfactory bulb, but intensive staining was found in the deeper layer as well. The histochemical reaction was observed in the fibers of the olfactory nerve, in the glomeruli of the glomerular layer, several short axon (SA) cells (outer plexiform layer or granular layer) and neuronal projections that were visualized throughout the depth of the olfactory bulb. Furthermore, LacZ staining was observed in the limbic areas of the brain receiving olfactory input, i.e., piriform cortex molecular area, hippocampus (CA1 field, pyramidal layer), hypothalamic lateral zone (zone incerta) and lateral habenula. In addition, a histochemical reaction was found in the midbrain raphe nuclei and primary somatosensory area of the cortex (layer 5). Real-time quantitative PCR with reverse transcription confirmed TAAR2 gene expression in the mouse brain areas such as the frontal cortex, hypothalamus, and brainstem.
Involvement in the functioning of monoamine systems
TAAR2 knockout mice have significantly higher level of dopamine in the striatum tissue than wild-type littermates and lower level of norepinephrine in hippocampus. Also, they have lower levels of MAO-B expression in midbrain and striatum. A significantly higher number of the dopamine neurons was detected in TAAR2-KO mice in the substantia nigra pars compacta. TAAR2 knockout mice have significantly higher level of horizontal activity and lower immobilization time in forced swim test.
Involvement in adult neurogenesis
It has been found that TAAR2 knockout mice have an increased number of neuroblast-like and proliferating cells in both subventricular and subgranular zones of the dentate gyrus in comparison to wild type animals. Furthermore, TAAR2 knockout mice have an increased the brain-derived neurotrophic factor (BDNF) level in the striatum.
A single nucleotide polymorphism nonsense mutation of the TAAR2 gene is associated with schizophrenia. TAAR2 is a probable pseudogene in 10–15% of Asians as a result of a polymorphism that produces a premature stop codon at amino acid 168.
Involvement in immune cell migration and function
TCells, B Cells and Peripheral Mononuclear cells express TAAR2 mRNA. Migration toward TAAR1 ligands required both TAAR1 and TAAR2 expression based on siRNA experiments. In T cells, the same stimuli triggered cytokine secretion while in B cells Immunoglobulin secretion is triggered.
Possible Ligands
3‐Iodothyronamine (T1AM) was identified as a non-selective ligand for TAAR2. Additional TAAR1 ligands, tyramine and phenethylamine trigger TAAR2 dependant actions, though direct binding has not been demonstrated.
See also
Trace amine
Trace amine-associated receptor
References
G protein-coupled receptors | TAAR2 | [
"Chemistry"
] | 825 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,070 | https://en.wikipedia.org/wiki/TAAR3 | Putative trace amine-associated receptor 3 (TAAR3) is a human pseudogene with the gene symbol TAAR3P. In other species such as mice, TAAR3 is a functional protein-coding gene that encodes a trace amine-associated receptor protein.
Isobutylamine is a known ligand of TAAR3 in mice associated with sexual behaviour in male mice.
Isopentylamine was identified as a ligand for murine TAAR3 eliciting aversive behavior.
See also
Trace amine-associated receptor
References
G protein-coupled receptors | TAAR3 | [
"Chemistry"
] | 121 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,087 | https://en.wikipedia.org/wiki/GPR55 | G protein-coupled receptor 55 also known as GPR55 is a G protein-coupled receptor that in humans is encoded by the GPR55 gene.
GPR55, along with GPR119 and GPR18, have been implicated as novel cannabinoid receptors.
History
GPR55 was identified and cloned for the first time in 1999. Later it was identified by an in silico screen as a putative cannabinoid receptor because of a similar amino acid sequence in the binding region. Research groups from Glaxo Smith Kline and Astra Zeneca characterized the receptor extensively because it was hoped to be responsible for the blood pressure lowering properties of cannabinoids. GPR55 is indeed activated by endogenous and exogenous cannabinoids such as plant and synthetic cannabinoids but GPR-55 knockout mice generated by a research group from Glaxo Smith Kline showed no altered blood pressure regulation after administration of the cannabidiol-derivative abnormal cannabidiol.
Signal cascade
GPR55 is coupled to the G-protein G13 and activation of the receptor leads to stimulation of rhoA, cdc42 and rac1.
Pharmacology
GPR55 is activated by the plant cannabinoids Δ9-THC and the endocannabinoids anandamide, 2-AG and noladin ether in the low nanomolar range. Exocannabinoids such as the synthetic cannabinoid CP-55940 are also able to activate the receptor while the structurally unrelated cannabinoid mimic WIN 55,212-2 fails to activate the receptor. Recent research suggests that lysophosphatidylinositol and its 2-arachidonoyl derivative, 2-arachidonoyl lysophosphatidylinositol (2-ALPI), may be the endogenous ligands for GPR55 and the receptor appears likely to be a possible target for treatment of inflammation and pain as with the other cannabinoid receptors.
This profile as a distinct non-CB1/CB2 receptor which responds to a variety of both endogenous and exogenous cannabinoid ligands has led some groups to suggest GPR55 should be categorised as the CB3 receptor, and this re-classification may follow in time. However this is complicated by the fact that another possible CB3 receptor has been discovered in the hippocampus, although its gene has not yet been cloned, suggesting that there may be at least four cannabinoid receptors which will eventually be characterised. Evidence accumulated during the last few years suggests that GPR55 plays a relevant role in cancer and opens the possibility of considering this orphan receptor as a new therapeutic target and potential biomarker in oncology.
Ligands
Agonists
Ligands found to bind to GPR55 as agonists include:
Lysophosphatidylinositol
2-Arachidonoyl lysophosphatidylinositol
Abnormal cannabidiol (Abn-CBD)
AM-251 (also CB1 antagonist)
CP 55,940
GSK-319,197
GSK-494,581 - also glycine transporter 1 inhibitor
GSK-522,373
O-1602
Δ9-Tetrahydrocannabinol
Tetrahydrocannabivarin (THCV)
2-Arachidonoylglycerol (2-AG)
Noladin ether
Oleoylethanolamide
Palmitoylethanolamide
ML-184, ML-185 and ML-186
Antagonists
CID-16020046 - inverse agonist at GPR55
O-1918
ML-191, ML-192 and ML-193
PSB-SB-487 and PSB-SB-1203
Cannabidiol
Physiological function
The physiological role of GPR55 is unclear. Mice with a target deletion of the GPR55 gene show no specific phenotype. GPR55 is widely expressed in the brain, especially in the cerebellum. It is expressed in the jejunum and ileum but apparently not more generally in the periphery. Osteoblasts and osteoclasts express GPR55 and this has been shown to regulate bone cell function.
References
Further reading
G protein-coupled receptors | GPR55 | [
"Chemistry"
] | 913 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,095 | https://en.wikipedia.org/wiki/GPR52 | Probable G-protein coupled receptor 52 is a protein that in humans is encoded by the GPR52 gene.
Members of the G protein-coupled receptor (GPR) family play important roles in signal transduction from the external environment to the inside of the cell.[supplied by OMIM]
Cannabidiol, CBD, and O-1918 are Inverse agonist at GPR52.
References
G protein-coupled receptors | GPR52 | [
"Chemistry"
] | 88 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,111 | https://en.wikipedia.org/wiki/S1PR2 | Sphingosine-1-phosphate receptor 2, also known as S1PR2 or S1P2, is a human gene which encodes a G protein-coupled receptor which binds the lipid signaling molecule sphingosine 1-phosphate (S1P).
Function
This protein participates in sphingosine 1-phosphate-induced cell proliferation, survival, and transcriptional activation. It has also been shown to interact with Nogo-A (RTN4), an neurite outgrowth inhibitor. S1PR2 is expressed in neuronal and vascular cells and is crucial for the migration and growth of developing and injured neuronal and vascular system.
Evolution
Paralogues
S1PR1
S1PR3
S1PR5
S1PR4
LPAR2
LPAR1
LPAR3
CNR1
GPR6
MC3R
GPR12
GPR3
MC4R
MC1R
CNR2
MC5R
MC2R
GPR119
See also
Lysophospholipid receptor
References
Further reading
External links
G protein-coupled receptors | S1PR2 | [
"Chemistry"
] | 224 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,145 | https://en.wikipedia.org/wiki/GABBR2 | Gamma-aminobutyric acid (GABA) B receptor, 2 (GABAB2) is a G-protein coupled receptor subunit encoded by the GABBR2 gene in humans.
Function
B-type receptors for the neurotransmitter GABA (gamma-aminobutyric acid) inhibit neuronal activity through G protein-coupled second-messenger systems, which regulate the release of neurotransmitters and the activity of ion channels and adenylyl cyclase. See GABBR1 (MIM 603540) for additional background information on GABA-B receptors.[supplied by OMIM]
Interactions
GABBR2 has been shown to interact with GABBR1.
See also
GABAB receptor
References
Further reading
External links
G protein-coupled receptors | GABBR2 | [
"Chemistry"
] | 167 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,175 | https://en.wikipedia.org/wiki/P2RY14 | P2Y purinoceptor 14 is a protein that in humans is encoded by the P2RY14 gene.
The product of this gene, P2Y14 belongs to the family of G-protein coupled receptors, which contains several receptor subtypes with different pharmacological selectivity for various adenosine and uridine nucleotides. This receptor is a P2Y purinergic receptor for UDP-glucose and other UDP-sugars coupled to G-proteins. It has been implicated in extending the known immune system functions of P2Y receptors by participating in the regulation of the stem cell compartment, and it may also play a role in neuroimmune function. Two transcript variants encoding the same protein have been identified for this gene.
See also
P2Y receptor
References
Further reading
External links
G protein-coupled receptors | P2RY14 | [
"Chemistry"
] | 179 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,191 | https://en.wikipedia.org/wiki/GPR64 | G protein-coupled receptor 64 also known as HE6 is a protein encoded by the ADGRG2 gene. GPR64 is a member of the adhesion GPCR family.
Adhesion GPCRs are characterized by an extended extracellular region often possessing N-terminal protein modules that is linked to a TM7 region via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.
The adhesion GPCR, GPR64, is an orphan receptor characterized by a long N-terminus with that has been suggested to be highly glycosylated. GPR64's N-terminus has been reported to be cleaved at the GPS domain to allow for trafficking to the plasma membrane. After cleavage the N-terminus is believed to remain non-covalently associated with the 7TM. GPR64 expression has been mostly reported in the male reproductive organs, but more recently has been shown to be expressed in the parathyroid glands and central nervous system. GPR64 is mainly expressed in human and mouse epididymis as well as human prostate and parathyroid. GPR64, together with F-actin scaffold, locates at the nonciliated principal cells of the proximal male excurrent duct epithelia, where reabsorption of testicular fluid and concentration of sperm takes place.
Function
Targeting of Gpr64 in mice causes reduced fertility or infertility in males; but the reproductive capacity was unaffected in females. Unchanged hormone expression in knockout males indicates that the receptor functions immediately in the male genital tract. Lack of Gpr64 expression causes sperm stasis and duct obstruction due to abnormal fluid reabsorption. In addition, expression of GPR64 has been found in fibroblast-like synovial cells obtained from osteoarthritis but not from rheumatoid arthritis.
Clinical significance
GPR64 is significantly overexpressed in the Wnt signaling-dependent subgroup of medulloblastoma, as well as in ewing sarcomas and carcinomas derived from prostate, kidney or lung. Richter et al. demonstrated that GPR64 promotes tumor invasion and metastasis through placental growth factor and MMP1. Upregulation and activation of GPR64 are associated with primary hyperparathyroidism and hypersecretion of parathyroid hormone.
References
External links
Adhesion GPCR consortium
G protein-coupled receptors | GPR64 | [
"Chemistry"
] | 510 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,202 | https://en.wikipedia.org/wiki/LPAR6 | Lysophosphatidic acid receptor 6, also known as LPA6, P2RY5 and GPR87, is a protein that in humans is encoded by the LPAR6 gene. LPA6 is a G protein-coupled receptor that binds the lipid signaling molecule lysophosphatidic acid (LPA).
The protein encoded by this gene belongs to the family of G-protein coupled receptors, that are preferentially activated by adenosine and uridine nucleotides. This gene aligns with an internal intron of the retinoblastoma susceptibility gene in the reverse orientation.
Role in hair growth/loss
In February 2008, researchers at the University of Bonn announced they have found the genetic basis of two distinct forms of inherited hair loss, opening a broad path to treatments for baldness. They found that mutations in the gene P2RY5 causes a rare, inherited form of hair loss called hypotrichosis simplex. It is the first receptor in humans known to play a role in hair growth. The fact that any receptor plays a specific role in hair growth was previously unknown to scientists, and with this new knowledge a focus on finding more of these genes may be able to lead to therapies for many different types of hair loss.
In 2013, it was found that mutations in LPAR6 give rise to the Cornish Rex cat breed, which has a form of ectodermal dysplasia characterised by short woolly hair which is susceptible to loss.
See also
Lysophospholipid receptor
P2Y receptor
References
Further reading
External links
G protein-coupled receptors | LPAR6 | [
"Chemistry"
] | 342 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,247 | https://en.wikipedia.org/wiki/RRH | Peropsin, a visual pigment-like receptor, is a protein that in humans is encoded by the RRH gene. It belongs like other animal opsins to the G protein-coupled receptors. Even so, the first peropsins were already discovered in mice and humans in 1997, not much is known about them.
Photochemistry
Like most opsins, peropsins have in its seventh transmembrane domain a lysine corresponding to amino acid position 296 in cattle rhodopsin, which is important for retinal binding and light sensing.
In amphioxus, a cephalochordate, a peropsin binds in the dark-state all-trans-retinal instead of 11-cis-retinal, as it is in cattle rhodopsin. Therefore, peropsins have been suggested to be photoisomerases.
Tissue localization
In mice, a peropsin is localized to the apical microvilli of the retinal pigment epithelium (RPE). There, it regulates storage or the movement of vitamin A from the retina to the RPE. A peropsin is also expressed in keratinocytes of the human skin. In keratinocyte cell culture, it reacts to UV light if retinal is supplied. In chicken, a peropsin is expressed with an RGR-opsin in the pineal gland and the retina.
Gene localization and structure
The human peropsin gene lies on chromosome 4 band 4q25 and has six introns like RGR-opsins. However only two of these introns are inserted at the same place, which still indicates that peropsins and RGR-opsins are more closely related to each other than to the ciliary and rhabdomeric opsins. This shared gene structure is also reflected in opsin phylogenies, where peropsins and RGR-opsins are in the same group: The chromopsins.
Phylogeny
The peropsins are restricted to the craniates and the cephalochordates. The craniates are the taxon that contains mammals and with them humans. The peropsins are one of the seven subgroups of the chromopsins. The other groups are the RGR-opsins, the retinochromes, the nemopsins, the astropsins, the varropsins, and the gluopsins. The chromopsins are one of three subgroups of the tetraopsins (also known as RGR/Go or Group 4 opsins). The other groups are the neuropsins and the Go-opsins. The tetraopsins are one of the five major groups of the animal opsins, also known as type 2 opsins). The other groups are the ciliary opsins (c-opsins, cilopsins), the rhabdomeric opsins (r-opsins, rhabopsins), the xenopsins, and the nessopsins. Four of these subclades occur in Bilateria (all but the nessopsins). However, the bilaterian clades constitute a paraphyletic taxon without the opsins from the cnidarians.
In the phylogeny above, Each clade contains sequences from opsins and other G protein-coupled receptors. The number of sequences and two pie charts are shown next to the clade. The first pie chart shows the percentage of a certain amino acid at the position in the sequences corresponding to position 296 in cattle rhodopsin. The amino acids are color-coded. The colors are red for lysine (K), purple for glutamic acid (E), orange for arginine (R), dark and mid-gray for other amino acids, and light gray for sequences that have no data at that position. The second pie chart gives the taxon composition for each clade, green stands for craniates, dark green for cephalochordates, mid green for echinoderms, brown for nematodes, pale pink for annelids, dark blue for arthropods, light blue for mollusks, and purple for cnidarians. The branches to the clades have pie charts, which give support values for the branches. The values are from right to left SH-aLRT/aBayes/UFBoot. The branches are considered supported when SH-aLRT ≥ 80%, aBayes ≥ 0.95, and UFBoot ≥ 95%. If a support value is above its threshold the pie chart is black otherwise gray.
Clinical significance
Since RGR-opsin may be associated with retinitis pigmentosa, which is like peropsin also expressed in the retinal pigment epithelium, peropsin was screened for a link with retinitis pigmentosa. However, no link could be established.
References
G protein-coupled receptors | RRH | [
"Chemistry"
] | 1,039 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,264 | https://en.wikipedia.org/wiki/Cysteinyl%20leukotriene%20receptor%201 | Cysteinyl leukotriene receptor 1, also termed CYSLTR1, is a receptor for cysteinyl leukotrienes (LT) (see cysteinyl leukotrienes). CYSLTR1, by binding these cysteinyl LTs (CysLTs; viz, LTC4, LTD4, and to a much lesser extent, LTE4) contributes to mediating various allergic and hypersensitivity reactions in humans as well as models of the reactions in other animals.
Gene
The human gene maps to the X chromosome at position Xq13-Xq21, contains three exons with the entire open reading frame located in exon 3, and codes for a protein composed of 337 amino acids. The CYSLTR1 gene promoter region is distanced from 665 to 30 bp upstream of its transcription start site.
Expression
CYSLTR1 mRNA is expressed in lung smooth muscle, lung macrophages, monocytes, eosinophils, basophils, neutrophils, platelets, T cells, B lymphocytes, pluripotent hematopoietic stem cells (CD34+), mast cells, pancreas, small intestine, prostate, interstitial cells of the nasal mucosa, airway smooth muscle cells, bronchial fibroblasts and vascular endothelial cells.
Function
CysLTR1 is a G protein–coupled receptor that links to and when bound to its CysLT ligands activates the Gq alpha subunit and/or Ga subunit of its coupled G protein, depending on the cell type. Acting through these G proteins and their subunits, ligand-bound CysLTR1 activates a series of pathways that lead to cell function; the order of potency of the in stimulating CysLTR1 is LTD4>LTC4>LTE4 with LTE4 probably lacking sufficient potency to have much activity that operates through CysLTR1 in vivo.
CysLTR1 activation by LTC4 and/or LTD4 in animal models and humans causes: airway bronchoconstriction and hyper-responsiveness to bronchoconstriction agents such as histamine; increased vascular permeability, edema, influx of eosinophils and neutrophils, smooth muscle proliferation, collagen deposition, and fibrosis in various tissue sites; and mucin secretion by goblet cells, goblet cell metaplasia, and epithelial cell hypertrophy in the membranes of the respiratory system. Animal model and human tissue (preclinical studies) implicate CysLTR1 antagonists as having protective/reparative effects in models of brain injury (trauma-, ischemia-, and cold-induced), multiple sclerosis, auto-immune encephalomyelitis, Alzheimer's disease, and Parkinson's disease. CysLTR1 activation is also associated in animal models with decreasing the blood–brain barrier (i.e. increasing the permeability of brain capillaries to elements of the blood's soluble elements) as well as promoting the movement of leukocytes for the blood to brain tissues; these effects may increase the development and frequency of epileptic seizure as well as the entry of leucocyte-borne viruses such as HIV-1 into brain tissue.
Increased expression of CysLTR1 has been observed in transitional cell carcinoma of the urinary bladder, neuroblastoma and other brain cancers, prostate cancer, breast cancer, and colorectal cancer (CRC); indeed, CysLTR1 tumor expression is associated with poor survival prognoses in breast cancer and CRC patients, and drug inhibitors of CysLTR1 block the in vivo and in vivo (animal model) growth of CRC cells and tumors, respectively. The pro-cancer effects of CysLTR1 in CRC appear due to its ability to up-regulate pathways that increase in CRC cell proliferation and survival.
Other cysLT receptors include cysteinyl leukotriene receptor 2 (i.e. CysLTR2) and GPR99 (also termed the oxoglutarate receptor and, sometimes, CysLTR3). The order of potency of the in stimulating CysLTR2 is LTD4=LTC4>LTE4 with LTE4 probably lacking sufficient potency to have much activity that operates through CysLTR2 in vivo. GPR99 appears to be an important receptor for CysLTs, particularly for LTE4. The CysLTs show relative potencies of LTE4>LTC4>LTD4 in stimulating GPR99-bearing cells with GPR99-deficient mice exhibiting a dose-dependent loss of vascular permeability responses in skin to LTE4 but not to LTC4 or LTD4. This and other data suggest that GPR99 is an important receptor for the in vivo actions of LTE4 but not LTD4 or LTC4
The GPR17 receptor, also termed the uracil nucleotide/cysteinyl leukotriene receptor, was initially defined as a receptor for LTC4, LTD4, and uracil nucleotides. However, more recent studies from different laboratories could not confirm these results; they found that GPR17-bearing cells did not respond to these CysLTs or nucleotides but did find that cells expressing both CysLTR1 and GPR17 receptors exhibited a marked reduction in binding LTC4 and that mice lacking GPR17 were hyper-responsive to igE-induced passive cutaneous anaphylaxis. GPR17 therefore appears to inhibit CysLTR1, at least in these model systems. In striking contrast to these studies, studies concentration on neural tissues continue to find that Oligodendrocyte progenitor cells express GPR17 and respond through this receptor to LTC4, LTD4, and certain purines (see GPR17#Function).
The Purinergic receptor, P2Y12, while not directly binding or responding to CysLTs, appears to be activated as a consequence of activating CysLT1: blockage of P2Y12 activation either by receptor depletion or pharmacological methods inhibits many of the CysLTR1-dependent actions of CysLTs in various cell types in vitro as well as in an animal model of allergic disease.
Ligands
The major CysLTs viz., LTC4, LTD4, and LTE4, are metabolites of arachidonic acid made by the 5-lipoxygenase enzyme, ALOX5, mainly by cells involved in regulating inflammation, allergy, and other immune responses such as neutrophils, eosinophils, basophils, monocytes, macrophages, mast cells, dendritic cells, and B-lymphocytes. ALOX5 metabolizes arachidonic acid to the 5,6-epoxide precursor, LTA4, which is then acted on by LTC4 synthase which attaches the γ-glutamyl-cysteinyl-glycine tripeptide (i.e. glutathione) to carbon 6 of the intermediate thereby forming LTC4 synthase. LTC4 then exits its cells of origin through the MRP1 transporter (ABCC1) and is rapidly converted to LTD4 and then to LTE4) by cell surface-attached gamma-glutamyltransferase and dipeptidase peptidase enzymes by the sequential removal of the γ-glutamyl and then glycine residues.
Gene polymorphism
927T/C (nucleotide thymine replaces cytosine at position 97 of the CysLTR1 gene) gene polymorphism in the coding region of CysLTR1 has been shown to be predictive of the severity of atopy (i.e. a predisposition toward developing certain allergic hypersensitivity reactions), but not associated with asthma, in a population of 341 Caucasians in afflicted sib-pair families from the Southampton area in the United Kingdom. This atopy severity was most apparent in female siblings but the incidence of this polymorphism is extremely low and the functionality of the 927T/C gene and its product protein are as yet unknown.
The population of the small remote far South Atlantic Ocean island of Tristan da Cunha (266 permanent, genetically isolated residents) suffers a high prevalence of atopy and asthma. The CysLTR1 gene product variant, 300G/S (i.e. amino acid glycine replaces serine at the 300 position of the CysLTR1 protein), has been shown to be significantly associated with atopy in this population. The CysLTR1 300S variant exhibited significant increased sensitivity to LTD4 and LTC4 suggesting that this hypersensitivity underlies its association with atopy.
Clinical significance
In spite of the other receptors cited as being responsive to CysLTs, CysLTR1 appears to be critical in mediating many of the pathological responses to CysLTs in humans. Montelukast, Zafirlukast, and Pranlukast are selective receptor antagonists for the CysLTR1 but not CysLTR2. These drugs are in use and/or shown to be effective as prophylaxis and chronic treatments for allergic and non-allergic diseases such as: allergen-induced asthma and rhinitis; aspirin-exacerbated respiratory disease; exercise- and cold-air induced asthma (see Exercise-induced bronchoconstriction); and childhood sleep apnea due to adenotonsillar hypertrophy (see Acquired non-inflammatory myopathy#Diet and Trauma Induced Myopathy). However, responses to these drugs vary greatly with the drugs showing fairly high rates of poor responses and ~20% of patients reporting no change in symptoms after treatment with these agents. It seems possible that the responses of CysLTR2, GPR99, or other receptors to CysLT's may be contributing to these diseases.
See also
Eicosanoid receptor
Cysteinyl leukotriene receptor 2
GPR99
References
Further reading
External links
G protein-coupled receptors | Cysteinyl leukotriene receptor 1 | [
"Chemistry"
] | 2,177 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,281 | https://en.wikipedia.org/wiki/List%20of%20IEEE%20Milestones | The following list of the Institute of Electrical and Electronics Engineers (IEEE) milestones represents key historical achievements in electrical and electronic engineering.
Prior to 1800
1751 – Book Experiments and Observations on Electricity by Benjamin Franklin
1757–1775 – Benjamin Franklin's Work in London
1799 – Alessandro Volta's Electrical Battery Invention
1800–1850
1804 – Francisco Salvá Campillo's Electric Telegraph
1820–1827 – The Birth of Electrodynamics
1828–1837 – Pavel Schilling's Pioneering Contribution to Practical Telegraphy
1836 – Nicholas Callan's Pioneering Contributions to Electrical Science and Technology
1838 – Demonstration of Practical Telegraphy
1850–1870
1852 – Electric Fire alarm system
1860–1871 – Maxwell's equations
1860–1863 – First Studies on Ring Armature for Direct-Current Dynamos
1861 – Transcontinental Telegraph
1861–1867 – Standardisation of the Ohm
1866 – Landing of the Transatlantic Cable
1866 – County Kerry Transatlantic Cable Stations
1870–1890
1876 – First Intelligible Voice Transmission over Electric Wire
1876 – Thomas Alva Edison Historic Site at Menlo Park
1876 – First Distant Speech Transmission in Canada
1882 – Vulcan Street Plant
1882 – First Central Station in South Carolina
1882 – Pearl Street Station
1884 – First AIEE Technical Meeting
1885 – Galileo Ferraris's Rotating Fields and Early Induction Motors
1886 – Alternating Current Electrification, Great Barrington, Massachusetts, by William Stanley, Jr.
1886 – First Generation and Experimental Proof of Electromagnetic Waves
1886–1888 – Electric Lighting of the Kingdom of Hawaii
1887 – Thomas A. Edison West Orange Laboratories and Factories
1887 – Weston Meters, first portable current and voltage meters
1888 – Richmond Union Passenger Railway
1889 – Power System of Boston's Rapid Transit
1889 – First Exploration and Proof of Liquid Crystals
1890–1900
1890 – Discovery of Radioconduction by Édouard Branly, making use of a coherer
1890 – Keage Power Station, Japan's First Commercial Hydroelectric Plant
1891 – Ames Hydroelectric Generating Plant
1893 – Mill Creek No. 1 Hydroelectric Plant
1893 – Birth and Growth of Primary and Secondary Battery Industries in Japan
1894 – First Millimeter-wave Communication Experiments by Jagadish Chandra Bose
1895 – Adams Hydroelectric Generating Plant
1895 – Popov's Contribution to the Development of Wireless Communication
1895 – Guglielmo Marconi's Experiments in Wireless telegraphy
1895 – Electrification by Baltimore and Ohio Railroad
1895 – Krka-Šibenik Electric Power System
1895 – Folsom Powerhouse three-phase system
1896 – Budapest Metroline No. 1
1897 – Chivilingo Hydroelectric Plant
1898 – Decew Falls Hydro-Electric Plant
1898 – Rheinfelden Hydroelectric Power Plant
1898 – French Transatlantic Telegraph Cable
1899–1902 – First Operational Use Of Wireless Telegraphy in the Anglo-Boer War
1899 – Calcutta Electric Supply Corp
1900–1920
1900 – Georgetown Steam Hydro Generating Plant
1901 – Transmission of Transatlantic Radio Signals
1901 – Reception of Transatlantic Radio Signals
1901 – Early Developments in Remote-Control by Leonardo Torres Quevedo
1901–1902 – Rationalization of Units
1901–1905 String Galvanometer
1902 – Poulsen-Arc Radio Transmitter
1903 – Vučje Hydroelectric Plant
1904 – Alexanderson Radio Alternator
1904 – Fleming valve
1904 – Radar Predecessor
1906 – Pinawa Hydroelectric Power Project
1906 – First Wireless Radio Broadcast by Reginald Fessenden
1906 – Grand Central Terminal Electrification
1907 – Alternating-Current Electrification of the New York, New Haven and Hartford Railroad
1909 – Shoshone Transmission Line
1909 – World's First Reliable Hight Voltage Power Fuse
1911 – Discovery of superconductivity
1914 – Panama Canal Electrical and Control Installations
1915–1918 – Invention of Sonar
1916 – Czochralski Process
1920–1930
1920 – Westinghouse Radio Station KDKA (AM)
1920 – Funkerberg Königs Wusterhausen first radio broadcast in Germany
1921–1923 – Piezoelectric Oscillator
1921 – RCA Central, 220 kW transoceanic radio facility
1922 – Neutrodyne Circuit
1924 – Directive Shortwave Antenna (Yagi–Uda antenna)
1924–1941 – Development of electronic television
1924 – Enrico Fermi's major contribution to semiconductor statistics
1925 – Bell Telephone Laboratories
1926 – First Public Demonstration of Television
1928 – One-way police radio communication
1928 – Raman Effect
1929 – Shannon Scheme for the electrification of the Irish Free State
1929 – Largest private (DC) generating plant in the U.S.A.
1929 – Yosami Radio Transmitting Station
1929 – First blind takeoff, flight, and landing; using designated radio and aeronautical instrumentation
1930–1940
1930–1945 – Development of Ferrite Materials and their applications
1931 – Invention of Stereo Sound Reproduction
1932 – First Breaking of Enigma Code by the Team of Polish Cipher Bureau
1933 – Two-Way Police Radio Communication
1933 – Invention of a Temperature-Insensitive Quarz Oscillaiton Plate
1934 – Long-Range Shortwave Voice Transmissions from Byrd's Antarctic Expedition
1937 – Westinghouse Atom Smasher
1938 – Zenit Parabolic Reflector L-Band Pulsed Radar
1939 – Atanasoff–Berry Computer
1939–1945 – Code-breaking at Bletchley Park during World War II
1939 – Single-element Unidirectional Microphone – Shure Unidyne
1939 – Claude Shannon, development of Information Theory
1939–1949 – Development of the Cavity Magnetron
1940–1950
1940 – FM Police Radio Communication
1940–1945 – MIT Radiation Laboratory
1940–1946 – Loran, long range navigation
1941 – Opana Radar Site
1942–1945 – US Naval Computing Machine Laboratory
1944–1959 – Whirlwind Computer, Cambridge, Massachusetts
1944–1959 – Harvard Mark 1 Computer
1945 – Merrill Wheel-Balancing System
1945 – Rincón del Bonete Plant and Transmission System
1946 – Electronic Numerical Integrator and Computer (ENIAC)
1946–1953 – Monochrome-Compatible Electronic Color Television
1946 – Detection of Radar Signals Reflected from the Moon
1947 – Invention of the First Transistor at Bell Telephone Laboratories, Inc.
1947 – Invention of Holography
1948 – Birth of the Barcode
1948 – The Discovery of the Principle of Self-Complementarity in Antennas and the Mushiake Relationship
1948 – First Atomic Clock
1948–1951 – Manchester University "Baby" Computer and its Derivatives
1950–1960
1950–1969 – Electronic Technology for Space Rocket Launches
1950 – First External Cardiac Pacemaker
1951 – Manufacture of Transistors
1951 – Experimental Breeder Reactor I
1951–1958 – SAGE-Semi-Automatic Ground Environment
1951–1952 – A-0 Compiler and Initial Development of Automatic Programming
1953 – First Television Broadcast in Western Canada
1954 – Gotland High Voltage Direct Current Link
1955 – WEIZAC Computer
1956 – RAMAC
1956 – The First Submarine Transatlantic Telephone Cable System (TAT-1)
1956–1963 – Kurobe River No. 4 Hydropower Plant
1956 – Ampex Videotape Recorder
1956 – Birth of Silicon Valley
1957–1958 – First Wearable Cardiac Pacemaker
1957 – SRC/Thyristor
1957–1962 – Atlas Computer and the Invention of Virtual Memory
1958 – First Semiconductor Integrated Circuit (IC) by Jack Kilby
1958 – Star of Laufenburg Interconnection
1958 – The Trans-Canada Microwave System
1959 – Semiconductor planar process by Jean Hoerni and silicon integrated circuit by Robert Noyce
1959 – Commercialization and industrialization of photovoltaic cells by Sharp Corporation
1960–1970
1961–1984 – IBM Thomas J. Watson Research Center
1960 – TIROS I Television Infrared Observation Satellite
1960 – First Working Laser
1961–1964 – First Optical Fiber Laser and Amplifier
1962–1967 – Object-oriented programming
1962 – Stanford Linear Accelerator Center
1962 – Alouette-ISIS Satellite Program
1962 – First Transatlantic Television Signal via Satellite
1962 – First Transatlantic Transmission of a Television Signal via Satellite
1962 – First Transatlantic Reception of a Television Signal via Satellite
1962–1967 – Pioneering Work on the Quartz Electronic Wristwatch at Centre Electronique Horloger, Switzerland
1962 – Mercury spacecraft MA-6, Col. John Glenn piloted the Mercury Friendship 7 spacecraft in the first FAI-legal completed human-orbital flight on 20 February 1962.
1962–1972 – Grumman Lunar Module
1962–1972 – Apollo Guidance Computer
1962–1968 – First Geographic Information System
1962 – Semiconductor Laser
1963 – Taum Sauk Pumped-Storage Electric Power Plant
1963 – NAIC/Arecibo Radiotelescope
1963 – Taum Sauk Pumped-Storage Electric Power Plant
1963 – First Transpacific Reception of a Television (TV) Signal via Satellite
1963 – ASCII
1964 – Mount Fuji Radar System
1964 – Tokaido Shinkansen (Bullet Train)
1964–1973 – Pioneering Work on Electronic Calculators by Sharp Corporation
1964 – TPC-1 Transpacific Cable System
1964 – High-definition television System
1964 – BASIC Computer Language
1965–1984 – Alvin Deep-Sea Research Submersible
1965 – First 735 kV AC Transmission System
1965–1971 – Railroad Ticketing Examining System (developed by OMRON of Japan)
1965 – Dadda multiplier
1965 – Moore's Law
1965–1978 – Development of Computer Graphics and Visualization Techniques
1966 – Interactive Video Games
1966 – Shakey, the first mobile robot to be able to reason about its actions
1966 – DIALOG Online Search System
1967 – First Astronomical Observations Using Very Long Baseline Interferometry
1968 – CERN Experimental Instrumentation
1968 – Liquid-crystal display by George H. Heilmeier
1968 – Public Demonstration of Online Systems and Personal Computing
1969 – Electronic Quartz Wristwatch, Seiko Quartz-Astron 35SQ
1969 – Birth of the Internet
1969 – Inception of the ARPANET
1969–1975 – Invention of Public-key Cryptography
1969 – Apollo 11 Lunar Laser Ranging Experiment (LURE)
1969 – Parkes Radiotelescope
1969–1995 – Mode S Air Traffic Control Radar Beacon System
1970–1980
1970 – World's First Low-Loss Optical Fiber for Telecommunications
1971–1978 – The first word processor for the Japanese Language, JW-10
1969–1970 – SPICE Circuit Simulation Program
1971 – Demonstration of the ALOHA Packed Radio Data Network
1971 – First Computerized Tomography (CT) X-ray Scanner
1971–1977 – Development of the Commercial Laser Printer
1972 – Nelson River HVDC Transmission System
1972 – Development of the HP-35, the First Handheld Scientific Calculator
1972 – Eel River High Voltage Direct Current Converter Station
1972 – First Practical Field Emission Electron Microscope
1972 – SHAKEY: The World’s First Mobile Intelligent Robot
1972 – Polymer Self-Regulating Heat-Tracing Cable
1972–1989 – Gravitational-Wave Antenna
1972–1987 – Deep Space Station 43
1972–1983 – The Xerox Alto Establishes Personal Networked Computing
1973–1985 – Superconducting Magnet System for the Fermilab Tevatron Accelerator/Collider
1973 – The First Two-Dimensional Nuclear Magnetic Resonance Image (MRI)
1973–1985 – Ethernet Local Area Network (LAN)
1974 – First 500 MeV Proton Beam from the TRIUMF Cyclotron
1974–1982 – First Real-Time Speech Communication on Packet Networks
1974 – The CP/M Microcomputer Operating System
1974 – Transmission Control Protocol (TCP) Enables the Internet
1975 – Line Spectrum Pair (LSP) for high-compression speech coding
1975 – Gapless Metal Oxide Surge Arrester (MOSA) for electric power systems
1975 – Handheld Digital Camera
1976 – Development of VHS, a World Standard for Home Video Recording
1976–1978 – The Floating Gate EEPROM
1977 – Lempel–Ziv Data Compression Algorithm
1977 – Vapor-phase Axial Deposition Method for Mass Production of High-quality Optical Fiber
1977 – Perpendicular Magnetic Recording
1978 – Speak & Spell, the First Use of a Digital Signal Processing IC for Speech Generation
1978 – First Digitally Processed Image from a Spaceborne Synthetic Aperture Radar
1978 – First Demonstration of a Fibre Bragg Grating
1979 – Compact disc Audio Player
1979 – 20-inch Diameter Photomultiplier Tubes
1979 – Amorphous Silicon Thin Film Field-Effect Transistor Switches for Liquid Crystal Displays
1979 – HEMT (high-electron-mobility transistor)
1980 to present
1980 – International Standardization of Group 3 Facsimile
1980–1982 – First RISC (Reduced Instruction-Set Computing) Microprocessor
1980 – Outdoor large-scale color display system
1980 – MPD7720DSP, programmable digital signal processor chip μPD7720
1980–1981 – Inverter-Driven Air Conditioner
1980–1999 – Origin of the IEEE 802 Family of Networking Standards
1981 – 16-Bit Monolithic Digital-to-analog converter (DAC) for Digital Audio
1981 – Map-Based Automotive navigation system
1981–1988 – The Development of RenderMan for Photorealistic Graphics
1982 – Nobeyama 45-m Telescope
1982 – Human Rescue Enabled by Space Technology
1982 – First Large-Scale Fingerprint ID
1982 – Commercialization of Multilayer Ceramic Capacitors with Nickel Electrodes
1984 – First Direct-broadcast satellite Service
1984 – The MU (Middle and Upper atmosphere) radar
1984–1989 – Active Shielding of Superconducting Magnets
1984–1993 – MPEG Multimedia Integrated Circuits
1984 – TRON Real-time Operating System Family
1984–1996 – Development of 193-nm Projection Photolithography
1985 – Toshiba T1100, a Pioneering Contribution to the Development of Laptop PC
1985 – Emergency Warning Code Signal Broadcasting System
1985 – Multiple Technologies on a Chip
1985 – IEEE Standard 754 for Binary Floating-Point Arithmetic
1986 – Fiber Optic Connectors
1987 – High-Temperature Superconductivity
1987 – SPARC RISC Architecture
1987 – Superconductivity at 93 Kelvin
1987 – WaveLAN, Precursor of Wi-Fi
1987–1995 – MTI Portable Satellite Communication Terminals
1988 – Sharp 14-Inch Thin Film Transistor Liquid-Crystal Display (TFT-LCD) for TV
1988 – Virginia Smith High-Voltage Direct-Current Converter Station
1988 – Trans-Atlantic Telephone Fiber-optic Submarine Cable, TAT-8
1988 – First Robotic Control from Human Brain Signals
1989 – Development of CDMA for Cellular Communications
1994 – Giant Metrewave Radio Telescope
1994 – QR (Quick Response) Code
1996–1998 – PageRank and the Birth of Google
1996 – Large-Scale Commercialization of a CDMA Cellular Communication System
Notes
References
External links
Map of IEEE Milestone plaques
Electrical-engineering-related lists
History of electrical engineering
Milestones
Electrical
Electrical and electronic engineering | List of IEEE Milestones | [
"Engineering"
] | 2,900 | [
"Institute of Electrical and Electronics Engineers",
"Electrical-engineering-related lists",
"Electrical engineering organizations",
"Electrical engineering",
"History of electrical engineering"
] |
14,429,284 | https://en.wikipedia.org/wiki/Neuropeptide%20FF%20receptor%202 | Neuropeptide FF receptor 2, also known as NPFF2 is a human protein encoded by the NPFFR2 gene.
See also
Neuropeptide FF receptor
References
Further reading
External links
G protein-coupled receptors | Neuropeptide FF receptor 2 | [
"Chemistry"
] | 49 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,301 | https://en.wikipedia.org/wiki/Prokineticin%20receptor%201 | Prokineticin receptor 1, also known as PKR1, is a human protein encoded by the PROKR1 gene.
See also
Prokineticin receptor
References
Further reading
External links
G protein-coupled receptors | Prokineticin receptor 1 | [
"Chemistry"
] | 45 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,318 | https://en.wikipedia.org/wiki/GPR75 | Probable G-protein coupled receptor 75 is a protein that in humans is encoded by the GPR75 gene.
Function
GPR75 is a member of the G protein-coupled receptor family. GPRs are cell surface receptors that activate guanine-nucleotide binding proteins upon the binding of a ligand.
GPR75 is currently classified as an orphan GPCR and several studies are underway to identify its ligand. In one study, the chemokine CCL5 (RANTES) has been shown to stimulate calcium mobilization and inositol triphosphate formation in GPR75-transfected cells.
A 2021 study reported that people with protein-truncating variants of GPR75 were associated with 5.3kg lower body weight and 54% lower odds for obesity. GPR75 knock-out mice showed resistance to weight gain under high-fat diet.
References
G protein-coupled receptors | GPR75 | [
"Chemistry"
] | 187 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,328 | https://en.wikipedia.org/wiki/Frizzled-10 | Frizzled-10 (Fz-10) is a protein that in humans is encoded by the FZD10 gene. Fz-10 has also been designated as CD350 (cluster of differentiation 350).
Function
This gene is a member of the frizzled gene family. Members of this family encode 7-transmembrane domain proteins that are receptors for the Wingless type MMTV integration site family of signaling proteins. Most frizzled receptors are coupled to the beta-catenin canonical signaling pathway. Using array analysis, expression of this intronless gene is significantly up-regulated in two cases of primary colon cancer.
References
Further reading
External links
Clusters of differentiation
G protein-coupled receptors | Frizzled-10 | [
"Chemistry"
] | 150 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,350 | https://en.wikipedia.org/wiki/GPR45 | Probable G-protein coupled receptor 45 is a protein that in humans is encoded by the GPR45 gene.
This intronless gene encodes a member of the G protein-coupled receptor (GPCR) family. Members of this protein family contain seven putative transmembrane domains and may mediate signaling processes to the interior of the cell via activation of heterotrimeric G proteins. This protein may function in the central nervous system.
References
Further reading
G protein-coupled receptors | GPR45 | [
"Chemistry"
] | 100 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,376 | https://en.wikipedia.org/wiki/Prostaglandin%20DP2%20receptor | {{DISPLAYTITLE:Prostaglandin DP2 receptor}}
Prostaglandin D2 receptor 2 (DP2 or CRTH2) is a human protein encoded by the PTGDR2 gene. DP2 has also been designated as CD294 (cluster of differentiation 294). It is a member of the class of prostaglandin receptors which bind with and respond to various prostaglandins. DP2 along with prostaglandin DP1 receptor are receptors for prostglandin D2 (PGD2). Activation of DP2 by PGD2 or other cognate receptor ligands has been associated with certain physiological and pathological responses, particularly those associated with allergy and inflammation, in animal models and certain human diseases.
Gene
The PTGDR2 gene is located on human chromosome 11 at position q12.2 (i.e. 11q12.2). It consists of two introns and three exons and codes for a G protein coupled receptor (GPCR) composed of 472 amino acids. DP2, is related to members of the chemotactic factor class of GPCRs, sharing an amino acid sequence identity of 29% with the C5a receptor, Formyl peptide receptor 1, and Formyl peptide receptor 2 receptors. DP2 has little or no such amino acid sequence relationship to the eight other Prostanoid receptors (see Eicosanoid receptor#Prostenoid receptors).
Expression
DP2 was found to stimulate the directed movement or chemotaxis of human T-helper type 2 cells (see T helper cell#Th1/Th2 Model for helper T cells) by binding to a receptor initially termed GPR44 and thereafter CRTH2 (for Chemoattractant Receptor-homologous molecule expressed on T-Helper type 2 cells). In addition to these T helper cells, DP2 messenger RNA is also expressed by human basophils, eosinophils, a subpopulation of cytotoxic T cells (i.e. CD8+ T cells), thalamus, ovary, and spleen, and, in the central nervous system, by the frontal cortex, pons, hippocampus, and at lower levels, hypothalamus and caudate nucleus/putamen. These transcripts are also detected in fetal liver and thymus.
Ligands
Activating ligands
The following standard prostaglandins have the following relative affinities and potencies in binding to and activating DP2: PGD2>>PGF2alpha=PGE2>PGI2=thromboxane A2. The cyclopentenone prostaglandins, PGJ2, Δ12-PGJ2, and 15-d-Δ12,14-PGJ2 are spontaneously formed or protein-facilitated derivatives of PGD2 that are generated in vitro as well as in vivo; these derivatives have binding affinities and activating potencies on DP2 that are similar to PGD2. Studies suggest that at least some if not most or all of the cytotoxic effects of cylopenenone prostaglandin derivatives of PGD2 act independently of DP2. Certain metabolites and derivatives of PGD2 viz., 13,14-dihydro-15-keto-PGD2 and 15(S)-15-methyl-PGD2, are ~10-fold less active than PGD2 while the drug indomethacin is weak in activating DP2.
Inhibiting ligands
The following compounds are selective receptor antagonists of and thereby inhibit the activation of DP2: fevipiprant, setipiprant, ADC-3680, AZD-1981, MK-1029, MK-7246, OC-459, OC000459, QAV-680, and TM30089. Ramatroban and vidupiprant are non-selective (i.e. known to influence other receptors) antagonists of DP2.
Mechanisms of cell activation
G protein-coupled receptors (GPCRs) such as DP2 are integral membrane proteins that, when bound by their cognate ligands (or, in some cases, even when not ligand-bound and thereby acting continuously in a constitutive manner {see Receptor (biochemistry)#Constitutive activity}), mobilize one or more types of Heterotrimeric G proteins. DP2 is classified as a "contractile" prostanoid receptor in that it can cause the contraction of smooth muscle. As evidenced by its initial discovery as a receptor for PGD2 in T-helper type 2 cells, activated DP2 triggers Gi alpha subunit-linked heterotrimeric G proteins to dissociate into their component a) Gi alpha subunits (also termed Giα subunits) inhibit adenylyl cyclase b) G beta-gamma complex of subunits (Gβγ) have many potential functions, including simulation of phospholipase C to cleave phosphatidylinositol triphosphate into inositol triphosphate (IP3) and diacylglycerol (DAG), inhibition or stimulation of adenylyl cyclase depending on the isoform, activation of GIRK channels and activation of GRK. IP3 raises cytosolic Ca2 levels thereby regulating Ca2-sensitive signal pathways; DAG activates certain protein kinase C enzymes )PKCs) that phosphorylate and thereby regulate target proteins involved in cell signaling; and adenyl cyclase converts AMP into cyclic AMP (cAMP) thereby down-regulating cAMP-responsive proteins involved in cell signalling. Concurrently with the mobilization of these pathways, activated DP2 also mobilizes G protein-coupled receptor kinases (GRKs, GRK2, GRK3, and/or GRK6) and Arrestin-2 (also termed Arrestin beta 1 or β-arrestin). The GRKs, along with the DAG-activated PKCs, phosphorylate DP2 to promote its internalization while arrestin-2 inhibits DP2 from further activating heterotrimeric G proteins while also linking DP2 to elements, clathrin and clathrin adaptor AP2, of the receptor internalization machinery. These pathways render DP2 unable to mobilize heterotrimereic G proteins thereby rendering the cell less sensitive or insensitive to further stimulation by DP ligands. The process, termed Homologous desensitization, serves as a physiological limiter of cell responses to DP2 activators.
Function
Allergy
Ligands that activate DP2 stimulate the in vitro chemotaxis (i.e. directed migration) of leukocytes active in mediating allergic responses viz., eosinophils, basophils, and Th2 cells. DP2 activation also stimulates eosinophils and basophils to release the many pro-allergic elements of their granules to the extracellular milieu. Ligand-induced activation of DP2 has similar activities in vivo it stimulates the accumulation on and activation of eosinophils, basophils, and Th2 cells at sites of nascent inflammation in animal models. PGD2, acting through DP2, stimulates the in vitro chemotaxis of CD8+ cells, although the contribution of this to the in vivo function of DP2 has not been clarified.
PDP2 receptor antagonists have been shown to allergic reactions induced in the airways mice and sheep as well as the airways and nose of guinea pigs.
Mice genetically engineered to be deficient in DP2 (i.e. DP2−/-) mice are defective in mounting asthmatic responses in models of: a) allergen-induced asthma, b) dermal allergy, c) ACTH and cortisol release in response to inflammatory stimuli, and c) perception of pain caused by inflammation in peripheral tissues. DP2−/- mice are also highly resistant to the gram (-) bacterial sepsis caused by cecal ligation and puncture; the protective effect was associated with lower bacterial load and lower production of pro-inflammatory cytokines (i.e. TNF-α, IL-6, and CCL3) and increased production of an anti-inflammatory cytokine (IL-10).
Embryogenesis
Studies in Dp2 gene-deficient (i.e. Dp2−/-) mice indicate that DP2 is essential for controlling cell cycle genes in fetal testes which contribute to the arrest of mitotic process and to the differentiate of germ cells. This control involves, at least in part, the DP2-dependent activation of the male germ cell marker Nanos2 and the inhibition of meiosis through repression of Stra8.
Human genomics studies
The 1544G-1651G haplotype in the 3'-untranslated region of the DP2 gene increased the stability of the gene's mRNA; this haplotype has been associated with an increased incidence of asthma in Chinese population and African but not Japanese sampling studies. The rs11571288 C/G Single-nucleotide polymorphism (SNP) variant of DP2 has been associated with an increase in the percentage of circulating eosinophils, an increase in the expression of DP2 by these cells, an enhanced rate of differentiation of precursor cells to Th2 cells in culture, enhanced Th2 cytokine (i.e. IL-4 and IL-13) production by these cells, and an increased incidence of asthma in a sampling of multi-ethnic Caucasian Canadians.
Clinical studies
Allergic Diseases
Setipiprant (ACT-129968), a selective, orally active antagonist of the DP2 receptor, proved to be well tolerated and reasonably effective in reducing allergen-induced airway responses in asthmatic patient clinical trials. However, the drug, while supporting the concept that DP2 contributes to asthmatic disease, did not show sufficient advantage over existing drugs and was discontinued from further development for this application (see setipiprant).
Patients with the chronic spontaneous urticarial form of hives exhibit significantly lower surface membrane expression of the DP22 receptor on their blood eosinophils and basophils, a result fully consistent with this receptor being initially activated and subsequently desensitization (refer to above section on "Mechanisms of cell activation"). The DP2 receptor antagonist, AZD1981, is in a phase 2 clinical trial for the treatment of chronic idiopathic urticarial.
A randomized, partially-blinded, placebo-controlled, two-way crossover, proof of concept study comparing the efficacy of the DP2 receptor antagonist, QAV680, in the treatment of allergic rhinitis and a study on the effectiveness of OC000459, a DP2 receptor antagonist, in reducing the exacerbation of asthma induced by experimentally-induced rhinovirus infection in subjects has just been completed or is underway, respectively.
Other diseases and conditions
Baldness
Acting through DP2, PGD2 can inhibit hair growth, suggesting that this receptor is a potential target for bald treatment. A potential drug for blocking the DP2 receptor and thereby ameliorating baldness is the compound setipiprant. A phase 2A study is underway to evaluate the safety, tolerability, and efficacy of oral setipiprant relative to a placebo in 18- to 49-year-old males with androgenetic alopecia.
See also
Prostaglandin DP1 receptor
Prostaglandin receptors
Prostanoid receptors
Eicosanoid receptor
References
Further reading
External links
Clusters of differentiation
G protein-coupled receptors | Prostaglandin DP2 receptor | [
"Chemistry"
] | 2,525 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,463 | https://en.wikipedia.org/wiki/OPN3 | Opsin-3 also known as encephalopsin or panopsin is a protein that, in humans, is encoded by the OPN3 gene. Alternative splicing of this gene results in multiple transcript variants encoding different protein isoforms.
Function
Opsins are members of the G protein-coupled receptor superfamily. In addition to the visual opsins, mammals possess several photoreceptive non-visual opsins that are expressed in tissues outside the eye. The opsin-3 gene is strongly expressed in brain and testis and weakly expressed in liver, placenta, heart, lung, skeletal muscle, kidney, and pancreas. The gene is expressed in the skin and may also be expressed in the retina. The protein has the canonical features of a photoreceptive opsin protein, however in human skin, OPN3 is not photoreceptive and acts as a negative regulator of melanogenesis.
Applications
When OPN3 analogues are expressed in neurons, activation by light inhibits neurotransmitter release. This makes these analogues useful tools for optogenetic silencing, a method to study the impact of specific neurons on brain function.
References
Further reading
G protein-coupled receptors | OPN3 | [
"Chemistry"
] | 250 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,471 | https://en.wikipedia.org/wiki/Neurotensin%20receptor%202 | Neurotensin receptor type 2 is a protein that in humans is encoded by the NTSR2 gene.
Function
The protein encoded by this gene belongs to the G protein-coupled receptor family that activates a phosphatidylinositol-calcium second messenger system. Binding and pharmacological studies demonstrate that this receptor binds Neurotensin (NT) as well as several other ligands already described for Neurotensin receptor 1. NT function is known to be a neuromodulator of dopamine and has hypothermic and analgesic properties in the brain and some peripheral organ function as well. NTS2 is found mostly in the brain through Northern-blot analysis.Unlike NTS1, NTS2 has a low affinity with NT and a high sensitivity to levocabastine, an antihistamine, which competes with NT for binding.
See also
Neurotensin receptor
References
Further reading
External links
G protein-coupled receptors | Neurotensin receptor 2 | [
"Chemistry"
] | 204 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,429,484 | https://en.wikipedia.org/wiki/GPR124 | Probable G-protein coupled receptor 124 is a protein that in humans is encoded by the GPR124 gene. It is a member of the adhesion-GPCR family of receptors. Family members are characterized by an extended extracellular region with a variable number of protein domains coupled to a TM7 domain via a domain known as the GPCR-Autoproteolysis INducing (GAIN) domain.
Interactions
GPR124 has been shown to interact with DLG1 and is involved in the Wnt/β-catenin signaling pathway along with RECK. GPR124 is the predicted target of several Group IV (+)ssRNA neuroinvasive viruses; proteolytic cleavage of GPR124 by these viral proteases may be important for entry into the brain. GPR124 (ADGRA2) was predicted using SSHHPS.
Zebrafish embryos with Gpr124 loss of function demonstrate severe angiogenic deficiencies in the central nervous system.
References
Further reading
G protein-coupled receptors | GPR124 | [
"Chemistry"
] | 216 | [
"G protein-coupled receptors",
"Signal transduction"
] |
14,430,019 | https://en.wikipedia.org/wiki/Landau%E2%80%93Zener%20formula | The Landau–Zener formula is an analytic solution to the equations of motion governing the transition dynamics of a two-state quantum system, with a time-dependent Hamiltonian varying such that the energy separation of the two states is a linear function of time. The formula, giving the probability of a diabatic (not adiabatic) transition between the two energy states, was published separately by Lev Landau, Clarence Zener, Ernst Stueckelberg, and Ettore Majorana, in 1932.
If the system starts, in the infinite past, in the lower energy eigenstate, we wish to calculate the probability of finding the system in the upper energy eigenstate in the infinite future (a so-called Landau–Zener transition). For infinitely slow variation of the energy difference (that is, a Landau–Zener velocity of zero), the adiabatic theorem tells us that no such transition will take place, as the system will always be in an instantaneous eigenstate of the Hamiltonian at that moment in time. At non-zero velocities, transitions occur with probability as described by the Landau–Zener formula.
Conditions and approximation
Such transitions occur between states of the entire system; hence any description of the system must include all external influences, including collisions and external electric and magnetic fields. In order that the equations of motion for the system might be solved analytically, a set of simplifications are made, known collectively as the Landau–Zener approximation. The simplifications are as follows:
The perturbation parameter in the Hamiltonian is a known, linear function of time
The energy separation of the diabatic states varies linearly with time
The coupling in the diabatic Hamiltonian matrix is independent of time
The first simplification makes this a semi-classical treatment. In the case of an atom in a magnetic field, the field strength becomes a classical variable which can be precisely measured during the transition. This requirement is quite restrictive as a linear change will not, in general, be the optimal profile to achieve the desired transition probability.
The second simplification allows us to make the substitution
where and are the energies of the two states at time , given by the diagonal elements of the Hamiltonian matrix, and is a constant. For the case of an atom in a magnetic field this corresponds to a linear change in magnetic field. For a linear Zeeman shift this follows directly from point 1.
The final simplification requires that the time–dependent perturbation does not couple the diabatic states; rather, the coupling must be due to a static deviation from a Coulomb potential, commonly described by a quantum defect.
Formula
The details of Zener's solution are somewhat opaque, relying on a set of substitutions to put the equation of motion into the form of the Weber equation and using the known solution. A more transparent solution is provided by Curt Wittig using contour integration.
The key figure of merit in this approach is the Landau–Zener velocity:
where is the perturbation variable (electric or magnetic field, molecular bond-length, or any other perturbation to the system), and and are the energies of the two diabatic (crossing) states. A large results in a large diabatic transition probability and vice versa.
Using the Landau–Zener formula the probability, , of a diabatic transition is given by
The quantity is the off-diagonal element of the two-level system's Hamiltonian coupling the bases, and as such it is half the distance between the two unperturbed eigenenergies at the avoided crossing, when .
Multistate problem
The simplest generalization of the two-state Landau–Zener model is a multistate system with a Hamiltonian of the form
,
where A and B are Hermitian NxN matrices with time-independent elements. The goal of the multistate Landau–Zener theory is to determine elements of the scattering matrix and the transition probabilities between states of this model after evolution with such a Hamiltonian from negative infinite to positive infinite time. The transition probabilities are the absolute value squared of scattering matrix elements.
There are exact formulas, called hierarchy constraints, that provide analytical expressions for special elements of the scattering matrix in any multi-state Landau–Zener model. Special cases of these relations are known as the Brundobler–Elser (BE) formula,), and the no-go theorem,. Discrete symmetries often lead to constraints that reduce the number of independent elements of the scattering matrix.
There are also integrability conditions that, when they are satisfied, lead to exact expressions for the entire scattering matrices in multistate Landau–Zener models. Numerous such completely solvable models have been identified, including:
Demkov–Osherov model that describes a single level that crosses a band of parallel levels. A surprising fact about the solution of this model is coincidence of the exactly obtained transition probability matrix with its form obtained with a simple semiclassical independent crossing approximation. With some generalizations, this property appears in almost all solvable Landau–Zener systems with a finite number of interacting states.
Generalized bow-tie model. The model describes coupling of two (or one in the degenerate case limit) levels to a set of otherwise noninteracting diabatic states that cross at a single point.
Driven Tavis–Cummings model describes interaction of N spins- with a bosonic mode in a linearly time-dependent magnetic field. This is the richest known solved system. It has combinatorial complexity: the dimension of its state vector space is growing exponentially with the number of spins N. The transition probabilities in this model are described by the q-deformed binomial statistics. This solution has found practical applications in physics of Bose-Einstein condensates.
Spin clusters interacting with time-dependent magnetic fields. This class of models shows relatively complex behavior of the transition probabilities due to the path interference effects in the semiclassical independent crossing approximation.
Reducible (or composite) multistate Landau–Zener models. This class consists of systems that can be decoupled to subsets of other solvable and simpler models by a symmetry transformation. The notable example is an arbitrary spin Hamiltonian , where Sz and Sx are spin operators, and S>1/2; b and g are constant parameters. This is the earliest known solvable system, which was discussed by Majorana in 1932. Among the other examples there are models of a pair of degenerate level crossing, and the 1D quantum Ising chain in a linearly changing magnetic field.
Landau–Zener transitions in infinite linear chains. This class contains the systems with formally infinite number of interacting states. Although most known their instances can be obtained as limits of the finite size models (such as the Tavis–Cummings model), there are also cases that do not belong to this classification. For example, there are solvable infinite chains with nonzero couplings between non-nearest states.
Study of noise
Applications of the Landau–Zener solution to the problems of quantum state preparation and manipulation with discrete degrees of freedom stimulated the study of noise and decoherence effects on the transition probability in a driven two-state system. Several compact analytical results have been derived to describe these effects, including the Kayanuma formula
for a strong diagonal noise, and Pokrovsky–Sinitsyn formula
for the coupling to a fast colored noise with off-diagonal components.
Using the Schwinger–Keldysh Green's function, a rather complete and comprehensive study on the effect of quantum noise in all parameter regimes were performed by Ao and Rammer in late 1980s, from weak to strong coupling, low to high temperature, slow to fast passage, etc. Concise analytical expressions were obtained in various limits, showing the rich behaviors of such problem.
The effects of nuclear spin bath and heat bath coupling on the Landau–Zener process was explored by Sinitsyn and Prokof'ev and Pokrovsky and Sun, respectively.
Exact results in multistate Landau–Zener theory (no-go theorem and BE-formula) can be applied to Landau–Zener systems which are coupled to baths composed of infinite many oscillators and/or spin baths (dissipative Landau–Zener transitions). They provide exact expressions for transition probabilities averaged over final bath states if the evolution begins from the ground state at zero temperature, see in Ref. for oscillator baths and for universal results including spin baths in Ref.
See also
Nonadiabatic transition state theory
Adiabatic theorem
Bond softening
Bond hardening
Froissart-Stora equation
References
Quantum mechanics
Lev Landau | Landau–Zener formula | [
"Physics"
] | 1,803 | [
"Theoretical physics",
"Quantum mechanics"
] |
14,430,199 | https://en.wikipedia.org/wiki/Hilbert%E2%80%93Huang%20transform | The Hilbert–Huang transform (HHT) is a way to decompose a signal into so-called intrinsic mode functions (IMF) along with a trend, and obtain instantaneous frequency data. It is designed to work well for data that is nonstationary and nonlinear. In contrast to other common transforms like the Fourier transform, the HHT is an algorithm that can be applied to a data set, rather than a theoretical tool.
The Hilbert–Huang transform (HHT), a NASA designated name, was proposed by Norden E. Huang et al. (1996, 1998, 1999, 2003, 2012). It is the result of the empirical mode decomposition (EMD) and the Hilbert spectral analysis (HSA). The HHT uses the EMD method to decompose a signal into so-called intrinsic mode functions (IMF) with a trend, and applies the HSA method to the IMFs to obtain instantaneous frequency data. Since the signal is decomposed in time domain and the length of the IMFs is the same as the original signal, HHT preserves the characteristics of the varying frequency. This is an important advantage of HHT since a real-world signal usually has multiple causes happening in different time intervals. The HHT provides a new method of analyzing nonstationary and nonlinear time series data.
Definition
Empirical mode decomposition
The fundamental part of the HHT is the empirical mode decomposition (EMD) method. Breaking down signals into various components, EMD can be compared with other analysis methods such as Fourier transform and Wavelet transform. Using the EMD method, any complicated data set can be decomposed into a finite and often small number of components. These components form a complete and nearly orthogonal basis for the original signal. In addition, they can be described as intrinsic mode functions (IMF).
Because the first IMF usually carries the most oscillating (high-frequency) components, it can be rejected to remove high-frequency components (e.g., random noise). EMD based smoothing algorithms have been widely used in seismic data processing, where high-quality seismic records are highly demanded.
Without leaving the time domain, EMD is adaptive and highly efficient. Since the decomposition is based on the local characteristic time scale of the data, it can be applied to nonlinear and nonstationary processes.
Intrinsic mode functions
An intrinsic mode function (IMF) is defined as a function that satisfies the following requirements:
In the whole data set, the number of extrema and the number of zero-crossings must either be equal or differ at most by one.
At any point, the mean value of the envelope defined by the local maxima and the envelope defined by the local minima is zero.
It represents a generally simple oscillatory mode as a counterpart to the simple harmonic function. By definition, an IMF is any function with the same number of extrema and zero crossings, whose envelopes are symmetric with respect to zero. This definition guarantees a well-behaved Hilbert transform of the IMF.
Hilbert spectral analysis
Hilbert spectral analysis (HSA) is a method for examining each IMF's instantaneous frequency as functions of time. The final result is a frequency-time distribution of signal amplitude (or energy), designated as the Hilbert spectrum, which permits the identification of localized features.
Techniques
The Intrinsic Mode Function (IMF) amplitude and frequency can vary with time and it must satisfy the rule below:
The number of extremes(local maximums & local minimums) and the number of zero-crossings must either equal or differ at most by one.
At any point, the mean value of the envelope defined by the local maxima and the envelope defined by the local minima is near zero.
Empirical mode decomposition
The empirical mode decomposition (EMD) method is a necessary step to reduce any given data into a collection of intrinsic mode functions (IMF) to which the Hilbert spectral analysis can be applied.
IMF represents a simple oscillatory mode as a counterpart to the simple harmonic function, but it is much more general: instead of constant amplitude and frequency in a simple harmonic component, an IMF can have variable amplitude and frequency along the time axis.
The procedure of extracting an IMF is called sifting. The sifting process is as follows:
Identify all the local extrema in the test data.
Connect all the local maxima by a cubic spline line as the upper envelope.
Repeat the procedure for the local minima to produce the lower envelope.
The upper and lower envelopes should cover all the data between them. Their mean is m1. The difference between the data and m1 is the first component h1:
Ideally, h1 should satisfy the definition of an IMF, since the construction of h1 described above should have made it symmetric and having all maxima positive and all minima negative. After the first round of sifting, a crest may become a local maximum. New extrema generated in this way actually reveal the proper modes lost in the initial examination. In the subsequent sifting process, h1 can only be treated as a proto-IMF. In the next step, h1 is treated as data:
After repeated sifting up to k times, h1 becomes an IMF, that is
Then, h1k is designated as the first IMF component of the data:
Stoppage criteria of the sifting process
The stoppage criterion determines the number of sifting steps to produce an IMF. Following are the four existing stoppage criterion:
Standard deviation
This criterion is proposed by Huang et al. (1998). It is similar to the Cauchy convergence test, and we define a sum of the difference, SD, as
Then the sifting process stops when SD is smaller than a pre-given value.
S Number criterion
This criterion is based on the so-called S-number, which is defined as the number of consecutive siftings for which the number of zero-crossings and extrema are equal or at most differing by one. Specifically, an S-number is pre-selected. The sifting process will stop only if, for S consecutive siftings, the numbers of zero-crossings and extrema stay the same, and are equal or at most differ by one.
Threshold method
Proposed by Rilling, Flandrin and Gonçalvés, threshold method set two threshold values to guaranteeing globally small fluctuations in the meanwhile taking in account locally large excursions.
Energy difference tracking
Proposed by Cheng, Yu and Yang, energy different tracking method utilized the assumption that the original signal is a composition of orthogonal signals, and calculate the energy based on the assumption. If the result of EMD is not an orthogonal basis of the original signal, the amount of energy will be different from the original energy.
Once a stoppage criterion is selected, the first IMF, c1, can be obtained. Overall, c1 should contain the finest scale or the shortest period component of the signal. We can, then, separate c1 from the rest of the data by Since the residue, r1, still contains longer period variations in the data, it is treated as the new data and subjected to the same sifting process as described above.
This procedure can be repeated for all the subsequent rj's, and the result is
The sifting process finally stops when the residue, rn, becomes a monotonic function from which no more IMF can be extracted. From the above equations, we can induce that
Thus, a decomposition of the data into n-empirical modes is achieved. The components of the EMD are usually physically meaningful, for the characteristic scales are defined by the physical data. Flandrin et al. (2003) and Wu and Huang (2004) have shown that the EMD is equivalent to a dyadic filter bank.
Hilbert spectral analysis
Having obtained the intrinsic mode function components, the instantaneous frequency can be computed using the Hilbert transform. After performing the Hilbert transform on each IMF component, the original data can be expressed as the real part, Real, in the following form:
Current applications
Two-Dimensional EMD
In the above examples, all signals are one-dimensional signals, and in the case of two-dimensional signals, the Hilbert-Huang Transform can be applied for image and video processing in the following ways:
Pseudo-Two-Dimensional EMD (Pseudo-two-dimensional Empirical Mode Decomposition):
Directly splitting the two-dimensional signal into two sets of one-dimensional signals and applying the Hilbert-Huang Transform separately. After that, rearrange the two signals back into a two-dimensional signal.
The result can produce excellent patterns, and display local rapid oscillations in long-wavelength waves. However, this method has many drawbacks. The most significant one is the discontinuities, occurring when the two sets of processed Intrinsic Mode Functions (IMFs) are recombined into the original two-dimensional signal. The following methods can be used to address this issue.
Pseudo-Two-Dimensional EEMD (Pseudo-two-dimensional Ensemble Empirical Mode Decomposition):
Compared to Pseudo-Two-Dimensional EMD, using EEMD instead of EMD can effectively improve the issue of discontinuity. However, this method has limitations and it's only effective when the time scale is very clear, such as in the case of temperature detection in the North Atlantic. It is not suitable for situations where the time scale of the signal is unclear.
Genuine Two-Dimensional EMD (Genuine two-dimensional Empirical Mode Decomposition):
As Genuine Two-Dimensional EMD directly processes two-dimensional signals, it poses some definitional challenges.
How to determine the maximum value—should the edges of the image be considered, or should another method be used to define the maximum value?
How to choose the progressive manner after identifying the maximum value. While Bézier curves may be effective in one-dimensional signals, they may not be directly applicable to two-dimensional signals.
Therefore, Nunes et al. used radial basis functions and the Riesz transform to handle Genuine Two-Dimensional EMD. The following is the form of the Riesz transform. For a complex function f on .
for j = 1,2,...,d.
The constant is a dimension-normalized constant.
Linderhed used Genuine Two-Dimensional EMD for image compression. Compared to other compression methods, this approach provides a lower distortion rate. Song and Zhang [2001], Damerval et al. [2005], and Yuan et al. [2008] used Delaunay triangulation to find the upper and lower bounds of the image. Depending on the requirements for defining maxima and selecting different progressive methods, different effects can be obtained.
Other application
Improved EMD on ECG signals: Ahmadi et al.[2019] presented an Improved EMD and compared with other types of EMD. Results show the proposed algorithm provides no spurious IMF for these functions and is not placed in an infinite loop. EMD types comparison on ECG(Electrocardiography) signals reveal the improved EMD was an appropriate algorithm to be used for analyzing biological signals.
Biomedical applications: Huang et al. [1999b] analyzed the pulmonary arterial pressure on conscious and unrestrained rats.
Neuroscience: Pigorini et al. [2011] analyzed Human EEG response to Transcranial Magnetic Stimulation; Liang et al. [2005] analyzed the visual evoked potentials of macaque performing visual spatial attention task.
Epidemiology: Cummings et al. [2004] applied the EMD method to extract a 3-year-periodic mode embedded in Dengue Fever outbreak time series recorded in Thailand and assessed the travelling speed of Dengue Fever outbreaks. Yang et al. [2010] applied the EMD method to delineate sub-components of a variety of neuropsychiatric epidemiological time series, including the association between seasonal effect of Google search for depression [2010], association between suicide and air pollution in Taipei City [2011], and association between cold front and incidence of migraine in Taipei city [2011].
Chemistry and chemical engineering: Phillips et al. [2003] investigated a conformational change in Brownian dynamics and molecular dynamics simulations using a comparative analysis of HHT and wavelet methods. Wiley et al. [2004] used HHT to investigate the effect of reversible digitally filtered molecular dynamics which can enhance or suppress specific frequencies of motion. Montesinos et al. [2002] applied HHT to signals obtained from BWR neuron stability.
Financial applications: Huang et al. [2003b] applied HHT to nonstationary financial time series and used a weekly mortgage rate data.
Image processing: Hariharan et al. [2006] applied EMD to image fusion and enhancement. Chang et al. [2009] applied an improved EMD to iris recognition, which reported a 100% faster in computational speed without losing accuracy than the original EMD.
Atmospheric turbulence: Hong et al. [2010] applied HHT to turbulence data observed in the stable boundary layer to separate turbulent and non-turbulent motions.
Scaling processes with intermittency correction: Huang et al. [2008] has generalized the HHT into arbitrary order to take the intermittency correction of scaling processes into account, and applied this HHT-based method to hydrodynamic turbulence data collected in laboratory experiment,; daily river discharge,; Lagrangian single particle statistics from direct numerical simulation,; Tan et al., [2014], vorticity field of two dimensional turbulence,; Qiu et al.[2016], two dimensional bacterial turbulence,; Li & Huang [2014], China stock market,; Calif et al. [2013], solar radiation. A source code to realize the arbitrary order Hilbert spectral analysis can be found at .
Meteorological and atmospheric applications: Salisbury and Wimbush [2002], using Southern Oscillation Index data, applied the HHT technique to determine whether the Sphere of influence data are sufficiently noise free that useful predictions can be made and whether future El Nino southern oscillation events can be predicted from SOI data. Pan et al. [2002] used HHT to analyze satellite scatterometer wind data over the northwestern Pacific and compared the results to vector empirical orthogonal function results.
Ocean engineering: Schlurmann [2002] introduced the application of HHT to characterize nonlinear water waves from two different perspectives, using laboratory experiments. Veltcheva [2002] applied HHT to wave data from nearshore sea. Larsen et al. [2004] used HHT to characterize the underwater electromagnetic environment and identify transient manmade electromagnetic disturbances.
Seismic studies: Huang et al. [2001] used HHT to develop a spectral representation of earthquake data. Chen et al. [2002a] used HHT to determine the dispersion curves of seismic surface waves and compared their results to Fourier-based time-frequency analysis. Shen et al. [2003] applied HHT to ground motion and compared the HHT result with the Fourier spectrum.
Solar physics: Nakariakov et al. [2010] used EMD to demonstrate the triangular shape of quasi-periodic pulsations detected in the hard X-ray and microwave emission generated in solar flares. Barnhart and Eichinger [2010] used HHT to extract the periodic components within sunspot data, including the 11-year Schwabe, 22-year Hale, and ~100-year Gleissberg cycles. They compared their results with traditional Fourier analysis.
Structural applications: Quek et al. [2003] illustrate the feasibility of the HHT as a signal processing tool for locating an anomaly in the form of a crack, delamination, or stiffness loss in beams and plates based on physically acquired propagating wave signals. Using HHT, Li et al. [2003] analyzed the results of a pseudodynamic test of two rectangular reinforced concrete bridge columns.
Structural health monitoring: Pines and Salvino [2002] applied HHT in structural health monitoring. Yang et al. [2004] used HHT for damage detection, applying EMD to extract damage spikes due to sudden changes in structural stiffness. Yu et al. [2003] used HHT for fault diagnosis of roller bearings.
System identification: Chen and Xu [2002] explored the possibility of using HHT to identify the modal damping ratios of a structure with closely spaced modal frequencies and compared their results to FFT. Xu et al. [2003] compared the modal frequencies and damping ratios in various time increments and different winds for one of the tallest composite buildings in the world.
Speech recognition: Huang and Pan [2006] have used the HHT for speech pitch determination.
Astroparticle physics : Bellini et al. [2014] (Borexino collaboration), Measurement of the seasonal modulation of the solar neutrino fluxes with Borexino experiment, Phys. Rev. D 89, 112007 2014
Limitations
Chen and Feng [2003] proposed a technique to improve the HHT procedure. The authors noted that the EMD is limited in distinguishing different components in narrow-band signals. The narrow band may contain either (a) components that have adjacent frequencies or (b) components that are not adjacent in frequency but for which one of the components has a much higher energy intensity than the other components. The improved technique is based on beating-phenomenon waves.
Datig and Schlurmann [2004] conducted a comprehensive study on the performance and limitations of HHT with particular applications to irregular water waves. The authors did extensive investigation into the spline interpolation. The authors discussed using additional points, both forward and backward, to determine better envelopes. They also performed a parametric study on the proposed improvement and showed significant improvement in the overall EMD computations. The authors noted that HHT is capable of differentiating between time-variant components from any given data. Their study also showed that HHT was able to distinguish between riding and carrier waves.
Huang and Wu [2008] reviewed applications of the Hilbert–Huang transformation emphasizing that the HHT theoretical basis is purely empirical, and noting that "one of the main drawbacks of EMD is mode mixing". They also outline outstanding open problems with HHT, which include: End effects of the EMD, Spline problems, Best IMF selection and uniqueness. Although the ensemble EMD (EEMD) may help mitigate the latter.
End effect
End effect occurs at the beginning and end of the signal because there is no point before the first data point and after the last data point to be considered together. However, in most cases, these endpoints are not the extreme value of the signal. Therefore, when doing the EMD process of the HHT, the extreme envelope will diverge at the endpoints and cause significant errors.
This error distorts the IMF waveform at its endpoints. Furthermore, the error in the decomposition result accumulates through each repetition of the sifting process. When computing the instantaneous frequency and amplitude of IMFs, Fast Fourier Transform (FFT) result may cause Gibbs phenomenon and frequency leakage, leading to information loss.
Here are several methods are proposed to solve the end effect in HHT:
1. Characteristic wave extending method
This method leverages the inherent variation trend of the signal to extend itself, resulting in extensions that closely resemble the characteristics of the original data.
Waveform matching extension :
This extension is based on the assumption that similar waveforms repeat themselves within the signal. Therefore, a triangular waveform best matching the signal's boundary is identified within the signal's waveform. Local values within the signal's boundary can then be predicted based on the corresponding local values of the triangular waveform.
Mirror extending method:
Many signals exhibit internal repetition patterns. Leveraging this characteristic, the mirror extension method appends mirrored copies of the original signal to its ends. This simple and efficient approach significantly improves the accuracy of Intrinsic Mode Functions (IMFs) for periodic signals. However, it is not suitable for non-periodic signals and can introduce side effects. Several alternative strategies have been proposed to address these limitations
2. Data extending method
design and compute some needed parameters from the original signal for building a particular mathematical model. After that, the model predicts the trend of the two endpoints.
Support vector regression machine (SVRM) prediction :
This method utilizes machine learning techniques to tackle the end effect in HHT. Its advantages are adaptive, flexible, highly accurate, and effective for both periodic and non-periodic signals. Although computational complexity can be a concern, disregarding this factor reveals SVRM as a robust and effective solution for mitigating the end effect in HHT.
Autoregressive (AR) model :
By formulating the input-output relationship as linear equations with time-varying coefficients, AR modeling enables statistical prediction of the missing values at the signal's endpoints. This method requires minimal computational resources and proves particularly effective for analyzing stationary signals. However, its accuracy diminishes for non-stationary signals, and the selection of an appropriate model order can significantly impact its effectiveness.
Neural network prediction:
Leveraging the power of neural network learning, these methods offer a versatile and robust approach to mitigating the end effect in HHT. Various network architectures, including RBF-NN and GRNN , have emerged, demonstrating their ability to capture complex relationships within the signal and learn from large datasets.
Mode mixing problem
Mode mixing problem happens during the EMD process. A straightforward implementation of the sifting procedure produces mode mixing due to IMF mode rectification. Specific signals may not be separated into the same IMFs every time. This problem makes it hard to implement feature extraction, model training, and pattern recognition since the feature is no longer fixed in one labeling index. Mode mixing problem can be avoided by including an intermittence test during the HHT process.
Masking Method
Source:
The masking method improves EMD by allowing for the separation of similar frequency components through the following steps:
Construction of masking signal:
Construct masking signal from the frequency information of the original data, . This masking signal is designed to prevent lower-frequency components from IMFs obtained through EMD.
Perform EMD with masking signal:
EMD is again performed on the modified signal x+(n) = x(n) + s(n) to obtain the IMF z+(n), and similarly, on x-(n) = x(n) - s(n) to obtain the IMF z-(n). The IMF is then defined as z(n) = (z+(n) + z-(n))/2 .
Separation of Components:
By appropriately choosing the masking signal frequency, components with similar frequencies can be separated. The masking signal prevents mode mixing, allowing EMD to distinguish between closely spaced frequency components.
Error Minimization:
The choice of parameters for the masking signal, such as amplitude, will affect the performance of the algorithm.
The optimal choice of amplitude depends on the frequencies
Overall, the masking method enhances EMD by providing a means to prevent mode mixing, improving the accuracy and applicability of EMD in signal analysis
Ensemble empirical mode decomposition (EEMD)
Source:
EEMD adds finite amplitude white noise to the original signal. After that, decompose the signal into IMFs using EMD. The processing steps of EEMD are developed as follows:
Add finite amplitude white noise to the original signal.
Decompose the noisy signal into IMFs using EMD.
Repeat steps 1 and 2 multiple times to create an ensemble of IMFs.
Calculate the mean of each IMF across the ensemble to obtain the final IMF components.
The effects of the decomposition using the EEMD are that the added white noise series cancel each other(or fill all the scale space uniformly). The noise also enables the EMD method to be a truly dyadic filter bank for any data, which means that a signal of a similar scale in a noisy data set could be contained in one IMF component, significantly reducing the chance of mode mixing. This approach preserves the physical uniqueness of decomposition and represents a major improvement over the EMD method.
Comparison with other transforms
See also
Hilbert transform
Hilbert spectral analysis
Hilbert spectrum
Instantaneous frequency
Multidimensional empirical mode decomposition
Nonlinear
Wavelet transform
Fourier transform
Signal envelope
References
Signal processing
Telecommunication theory | Hilbert–Huang transform | [
"Technology",
"Engineering"
] | 5,017 | [
"Telecommunications engineering",
"Computer engineering",
"Signal processing"
] |
14,431,176 | https://en.wikipedia.org/wiki/Photochemical%20Reflectance%20Index | The Photochemical Reflectance Index (PRI) is a reflectance measurement developed by John Gamon during his tenure as a postdoctorate fellow supervised by Christopher Field at the Carnegie Institution for Science at Stanford University. The PRI is sensitive to changes in carotenoid pigments (e.g. xanthophyll pigments) in live foliage. Carotenoid pigments are indicative of photosynthetic light use efficiency, or the rate of carbon dioxide uptake by foliage per unit energy absorbed. As such, it is used in studies of vegetation productivity and stress. Because the PRI measures plant responses to stress, it can be used to assess general ecosystem health using satellite data or other forms of remote sensing. Applications include vegetation health in evergreen shrublands, forests, and agricultural crops prior to senescence. PRI is defined by the following equation using reflectance (ρ) at 531 and 570 nm wavelength:
Some authors use
The values range from –1 to 1.
Sources
ENVI Users Guide
John Gamon, Josep Penuelas, and Christopher Field (1992). A narrow-waveband spectral index that tracks diurnal changes in photosynthetic efficiency. Remote Sensing of environment, 41, 35-44.
Drolet, G.G. Heummrich, K.F. Hall, F.G., Middleton, E.M., Black, T.A., Barr, A.G. and Margolis, H.A. (2005). A MODIS-derived photochemical reflectance index to detect inter-annual variations in the photosynthetic light-use efficiency of a boreal deciduous forest. Remote Sensing of environment, 98, 212-224.
Biophysics
Botany
Remote sensing
1992 introductions | Photochemical Reflectance Index | [
"Physics",
"Biology"
] | 362 | [
"Plants",
"Applied and interdisciplinary physics",
"Biophysics",
"Botany"
] |
14,431,229 | https://en.wikipedia.org/wiki/Outline%20of%20nanotechnology | The following outline is provided as an overview of and topical guide to nanotechnology:
Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers.
Branches of nanotechnology
Green nanotechnology – use of nanotechnology to enhance the environmental-sustainability of processes currently producing negative externalities. It also refers to the use of the products of nanotechnology to enhance sustainability.
Nanoengineering – practice of engineering on the nanoscale.
Multi-disciplinary fields that include nanotechnology
Nanobiotechnology – intersection of nanotechnology and biology.
Ceramic engineering – science and technology of creating objects from inorganic, non-metallic materials.
Materials science – interdisciplinary field applying the properties of matter to various areas of science and engineering. It investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties.
Molecular engineering
Contributing fields
Nanoscience
Nanoelectronics – use of nanotechnology on electronic components, including transistors so small that inter-atomic interactions and quantum mechanical properties need to be studied extensively.
Nanomechanics – branch of nanoscience studying fundamental mechanical (elastic, thermal and kinetic) properties of physical systems at the nanometer scale.
Nanophotonics – study of the behavior of light on the nanometer scale.
Other contributing fields
Calculus
Chemistry
Computer science
Engineering
Miniaturization
Physics
Protein engineering
Quantum mechanics
Self-organization
Science
Supramolecular chemistry
Tissue engineering
Robotics
Medicine
Risks of nanotechnology
Implications of nanotechnology
Health impact of nanotechnology
Environmental impact of nanotechnology
Regulation of nanotechnology
Societal impact of nanotechnology
Applications of nanotechnology
Energy applications of nanotechnology
Quantum computing – computation using quantum mechanical phenomena, such as superposition and entanglement, to perform data operations.
List of nanotechnology applications
Nanomaterials
Nanomaterials – field that studies materials with morphological features on the nanoscale, and especially those that have special properties stemming from their nanoscale dimensions.
Fullerenes and carbon forms
Fullerene – any molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Fullerene spheres and tubes have applications in nanotechnology.
Allotropes of carbon –
Aggregated diamond nanorods –
Buckypaper –
Carbon nanofoam –
Carbon nanotube –
Nanoknot –
Nanotube membrane –
Fullerene chemistry –
Bingel reaction –
Endohedral hydrogen fullerene –
Prato reaction –
Endohedral fullerenes –
Fullerite –
Graphene –
Graphene nanoribbon –
Potential applications of carbon nanotubes –
Timeline of carbon nanotubes –
Nanoparticles and colloids
Nanoparticle –
Ceramics processing –
Colloid –
Colloidal crystal –
Diamondoids –
Fiveling -
Nanocomposite –
Nanostructure –
Nanocages –
Nanocomposite –
Nanofabrics –
Nanofiber –
Nanofoam –
Nanoknot –
Nanomesh –
Nanopillar –
Nanopin film –
Nanoring –
Nanorod –
Nanoshell –
Nanotube –
Quantum dot –
Quantum heterostructure –
Sculptured thin film –
Nanomedicine
Nanomedicine –
Lab-on-a-chip –
Nanobiotechnology –
Nanosensor –
Nanotoxicology –
Molecular self-assembly
Molecular self-assembly –
DNA nanotechnology –
DNA computing –
DNA machine –
DNA origami –
Self-assembled monolayer –
Supramolecular assembly –
Nanoelectronics
Nanoelectronics –
Break junction –
Chemical vapor deposition –
Microelectromechanical systems (MEMS)
Nanocircuits –
Nanocomputer –
Nanoelectromechanical systems (NEMS)
Surface micromachining –
Nanoelectromechanical relays
Molecular electronics
Molecular electronics –
Nanolithography
Nanolithography –
Electron beam lithography –
Ion-beam sculpting –
Nanoimprint lithography –
Photolithography –
Scanning probe lithography –
Molecular self-assembly –
IBM Millipede –
Molecular nanotechnology
Molecular nanotechnology –
Grey goo –
Mechanosynthesis –
Molecular assembler –
Molecular modelling –
Nanorobotics –
Smartdust –
Utility fog –
Nanochondria –
Programmable matter –
Self reconfigurable –
Self-replication –
Devices
Micromachinery –
Nano-abacus –
Nanomotor –
Nanopore –
Nanopore sequencing –
Quantum point contact –
Synthetic molecular motors –
Carbon nanotube actuators –
Microscopes and other devices
Microscopy –
Atomic force microscope –
Electron microscopy -
Scanning tunneling microscope –
Scanning probe microscope –
Sarfus –
Notable organizations in nanotechnology
List of nanotechnology organizations
Government
National Cancer Institute (US)
National Institutes of Health (US)
National Nanotechnology Initiative (US)
Russian Nanotechnology Corporation (RU)
Seventh Framework Programme (FP7) (EU)
Advocacy and information groups
American Chemistry Council (US)
American Nano Society (US)
Center for Responsible Nanotechnology (US)
Foresight Institute (US)
Project on Emerging Nanotechnologies (global)
Manufacturers
Cerion Nanomaterials, Metal / Metal Oxide / Ceramic Nanoparticles (US)
OCSiAl, Carbon Nanotubes (Luxembourg)
Notable figures in nanotechnology
Phaedon Avouris - first electronic devices made out of carbon nanotubes
Gerd Binnig - co-inventor of the scanning tunneling microscope
Heinrich Rohrer - co-inventor of the scanning tunneling microscope
Vicki Colvin Director for the Center for Biological and Environmental Nanotechnology, Rice University
Eric Drexler - was the first to theorise about nanotechnology in depth and popularised the subject
Richard Feynman - gave the first mention of some of the distinguishing concepts in a 1959 talk, entitled There's Plenty of Room at the Bottom
Robert Freitas - nanomedicine theorist
Andre Geim - Discoverer of 2-D carbon film called graphene
Sumio Iijima - discoverer of carbon nanotube
Harry Kroto - co-discoverer of buckminsterfullerene
Akhlesh Lakhtakia - conceptualized sculptured thin films
Ralph Merkle - nanotechnology theorist
Carlo Montemagno - inventor ATP nanobiomechanical motor (UCLA)
Erwin Wilhelm Müller - invented the field ion microscope, and the atom probe
Chris Phoenix - co-founder of the Center for Responsible Nanotechnology
Uri Sivan - set up and led the Russell Berrie Nanotechnology Research Institute at Technion in Israel
Richard Smalley - co-discoverer of buckminsterfullerene
Norio Taniguchi - coined the term "nano-technology"
Mike Treder - co-founder of the Center for Responsible Nanotechnology
Joseph Wang - pioneer in electrochemical sensors exploiting nanostructured materials; synthetic nanomotors
Alex Zettl - Built the first molecular motor based on carbon nanotubes
Russell M. Taylor II - co-director of the UNC CISMM
Adriano Cavalcanti - nanorobot expert working at CAN
Lajos P. Balogh - editor in chief of the Precision Nanomedicine journal
Charles M. Lieber - pioneer on nanoscale materials (Harvard)
See also
Catalyst
Macromolecule
Mesh networking
Monolayer
Nanometer
Nanosub
NBI Knowledgebase
Photonic crystal
Potential well
Quantum confinement
Quantum tunneling
Self-assembly
Self-organization
Technological singularity
Place these
History of nanotechnology
List of nanotechnology organizations
Nanotechnology in fiction
Outline of nanotechnology
Impact of nanotechnology
Nanomedicine
Nanotoxicology
Green nanotechnology
Health and safety hazards of nanomaterials
Regulation of nanotechnology
Nanomaterials
Fullerenes
Carbon nanotubes
Nanoparticles
Molecular self-assembly
Self-assembled monolayer
Supramolecular assembly
DNA nanotechnology
Nanoelectronics
Molecular scale electronics
Nanolithography
Nanometrology
Atomic force microscopy
Scanning tunneling microscope
Electron microscope
Super resolution microscopy
Nanotribology
Molecular nanotechnology
Molecular assembler
Nanorobotics
Mechanosynthesis
Molecular engineering
Further reading
Engines of Creation, by Eric Drexler
Nanosystems, by Eric Drexler
Nanotechnology: A Gentle Introduction to the Next Big Idea by Mark and Daniel Ratner,
There's Plenty of Room at the Bottom by Richard Feynman
The challenges of nanotechnology by Claire Auplat
References
External links
NanoTechMap The online exhibition of nanotechnology featuring over 4000 registered companies
What is Nanotechnology? (A Vega/BBC/OU Video Discussion).
Course on Introduction to Nanotechnology
Nanex Project
SAFENANO A nanotechnology initiative of the Institute of Occupational Medicine
Glossary of Drug Nanotechnology
Nanotechnology
Nanotechnology | Outline of nanotechnology | [
"Materials_science",
"Engineering"
] | 1,810 | [
"Nanotechnology",
"Materials science"
] |
14,431,561 | https://en.wikipedia.org/wiki/Space%20policy | Space policy is the political decision-making process for, and application of, public policy of a state (or association of states) regarding spaceflight and uses of outer space, both for civilian (scientific and commercial) and military purposes. International treaties, such as the 1967 Outer Space Treaty, attempt to maximize the peaceful uses of space and restrict the militarization of space.
Space policy intersects with science policy, since national space programs often perform or fund research in space science, and also with defense policy, for applications such as spy satellites and anti-satellite weapons. It also encompasses government regulation of third-party activities such as commercial communications satellites and private spaceflight.
Space policy also encompasses the creation and application of space law, and space advocacy organizations exist to support the cause of space exploration.
Space law
Space law is an area of the law that encompasses national and international law governing activities in outer space. There are currently six treaties that make up the body of international space law.
The inception of the field of space law began with the launch of the world's first artificial satellite by the Soviet Union in October 1957. Named Sputnik 1, the satellite was launched as part of the International Geophysical Year. Since that time, space law has evolved and assumed more importance as mankind has increasingly come to use and rely on space-based resources.
International space law consists of six international treaties, five declarations and principles, and other United Nations (UN) General Assembly resolutions. The UN Office for Outer Space Affairs (UNOOSA) is primarily responsible for the implementation of international space law, and helps advise governments and non-governmental organizations on space law.
International treaties
All treaties below except the Partial Test Ban Treaty were adopted by the UN General Assembly. The Partial Test Ban Treaty, being the first, was signed by the governments of the Soviet Union, the United Kingdom, and the United States in Moscow on August 5, 1963, before it was opened for signature by other countries.
Partial Test Ban Treaty
The Partial Test Ban Treaty was entered into force on October 10, 1963. The treaty prohibits nuclear weapons tests or nuclear explosions in the atmosphere, in outer space, and under water. It also prohibits nuclear explosions underground if they cause "radioactive debris to be present outside the territorial limits of the State under whose jurisdiction or control" the explosions were conducted.
With increased knowledge of the effects of nuclear fallout, the issue of nuclear tests and the resultant radioactive debris drew intensified public attention. As the treaty does not outright ban nuclear tests underground, hundreds of such tests were conducted in the following decades. The Partial Test Ban Treaty is seen as the first step towards global nuclear disarmament. Continued efforts in this direction include increasing public awareness through events such as the International Day for the Total Elimination of Nuclear Weapons.
Outer Space Treaty
The Outer Space Treaty was ratified on October 10, 1967. Key provisions of the treaty include prohibiting nuclear weapons in space; limiting the use of the Moon and all other celestial bodies to peaceful purposes; establishing that space shall be freely explored and used by all nations; and precluding any country from claiming sovereignty over outer space or any celestial body.
International challenges to the Outer Space Treaty have been attempted. Most prominently is the Bogota Declaration which asserts sovereignty over those portions of the geostationary orbit that continuously lie over the signatory nations' territory. The declaration has been signed by seven equatorial countries: Ecuador, Colombia, Congo, Zaire (in 1997 renamed to the Democratic Republic of the Congo), Uganda, Kenya, and Indonesia. These claims did not receive wider international support or recognition, and were subsequently largely abandoned.
With the increase of private satellites and counter-space technologies since 2016, there have been calls for an update to the Outer Space Treaty. This topic, amongst others, was discussed in 2021 at the annual Outer Space Security Conference in Geneva, Switzerland.
Rescue Agreement
The Rescue Agreement was ratified on December 3, 1968. The agreement's provisions elaborate on the rescue provisions set forth by the Outer Space Treaty. The agreement essentially requires that any state party to the agreement, upon becoming aware that the personnel of a spacecraft are in distress, must notify the launching authority and the Secretary General of the United Nations, and must provide all possible assistance to rescue the personnel of a spacecraft who have landed within that state's territory. Moreover, if the distress occurs in an area that is beyond the territory of any nation, then any state party that is in a position to do so shall, if necessary, extend assistance in the search and rescue operation.
At the time the agreement was drafted, rescuing travelers in space was unlikely, due to the limited launch capabilities of even the most advanced space programs. More recently, it has become more plausible. The Rescue Agreement has been criticized for being vague, especially regarding the definition of who is entitled to be rescued and the definition of what constitutes a spacecraft and its component parts. With the recent increase of commercial spaceflight providers, this distinction has become more relevant, raising questions as to whether space tourists are covered by the term "personnel of a spacecraft" used in the agreement. There have been calls to revisit these issues in international space law.
Liability Convention
The Liability Convention was ratified on September 1, 1972. The treaty expands on the liability rules created in the Outer Space Treaty. Its provisions state that a state bears international responsibility for all space objects that are launched within their territory. This means that regardless of who launches the space object, if it was launched from State A's territory, or from State A's facility, or if State A caused the launch to happen, then State A is fully liable for damages that result from that space object. In 1978, the crash of the nuclear-powered Soviet satellite Kosmos 954 in Canadian territory led to the only claim filed under the convention. More recently, in July and October 2021, China's Tiangong space station, with three astronauts aboard, performed "evasive maneuver(s)" to avoid collision with SpaceX's Starlink satellites. The Liability Convention does not introduce legal penalties for leaving space debris in Earth's orbit.
Registration Convention
The Registration Convention was ratified on September 15, 1976. The convention's provisions require states to provide details such as date and location of launch, as well as basic orbital parameters to the United Nations for each space object.
Moon Agreement
The Moon Agreement was ratified on July 11, 1984. The agreement is a multilateral treaty that turns jurisdiction of all celestial bodies (including the orbits around such bodies) over to the participant countries. Thus, all activities would conform to international law, including the United Nations Charter. It has not been ratified by any state that engages in self-launched human spaceflight (e.g. the United States, Russia, People's Republic of China), and thus it has little to no relevancy in international law.
Policy by country
United States
United States space policy is drafted by the Executive branch at the direction of the President of the United States, and submitted for approval and establishment of funding to the legislative process of the United States Congress. The President may also negotiate with other nations and sign space treaties on behalf of the US, according to his or her constitutional authority. Congress' final space policy product is, in the case of domestic policy a bill explicitly stating the policy objectives and the budget appropriation for their implementation to be submitted to the President for signature into law, or else a ratified treaty with other nations.
Space advocacy organizations (such as the Space Science Institute, National Space Society, and the Space Generation Advisory Council, learned societies such as the American Astronomical Society and the American Astronautical Society; and policy organizations such as the National Academies) may provide advice to the government and lobby for space goals.
Civilian and scientific space policy is carried out by the National Aeronautics and Space Administration (NASA, subsequent to 29 July 1958), and military space activities (communications, reconnaissance, intelligence, mapping, and missile defense) are carried out by various agencies of the Department of Defense. The President is legally responsible for deciding which space activities fall under the civilian and military areas. In addition, the Department of Commerce's National Oceanic and Atmospheric Administration operates various services with space components, such as the Landsat program.
The President consults with NASA and Department of Defense on their space activity plans, as potential input for the policy draft submitted to Congress. He or she also consults with the National Security Council, the Office of Science and Technology Policy, and the Office of Management and Budget to take into account Congress's expected willingness to provide necessary funding levels for proposed programs.
Once the President's policy draft or treaty is submitted to the Congress, civilian policies are reviewed by the House Subcommittee on Space and Aeronautics and the Senate Subcommittee on Science and Space. These committees also exercise oversight over NASA's operations and investigation of accidents such as the 1967 Apollo 1 fire. Military policies are reviewed and overseen by the House Subcommittee on Strategic Forces and the Senate Subcommittee on Strategic Forces, as well as the House Permanent Select Committee on Intelligence and the Senate Select Committee on Intelligence. The Senate Foreign Relations Committee conducts hearings on proposed space treaties, and the various appropriations committees have power over the budgets for space-related agencies. Space policy efforts are supported by Congressional agencies such as the Congressional Research Service, the Congressional Budget Office, and Government Accountability Office.
History
The early history of United States space policy is linked to the US–Soviet Space Race of the 1960s. The National Aeronautics and Space Act creating NASA was passed in 1958, after the launch of the Soviet Sputnik 1 satellite. Thereafter, in response to the flight of Yuri Gagarin as the first man in space, Kennedy in 1961 committed the United States to landing a man on the Moon by the end of the decade. Although the costs of the Vietnam War and the programs of the Great Society forced cuts to NASA's budget as early as 1965, the first Moon landing occurred in 1969, early in Richard Nixon's presidency. Under the Nixon administration NASA's budget continued to decline and three of the planned Apollo Moon landings were cancelled. The Nixon administration approved the beginning of the Space Shuttle program in 1972, but did not support funding of other projects such as a Mars landing, colonization of the Moon, or a permanent space station.
The Space Shuttle first launched in 1981, during Ronald Reagan's administration. Reagan in 1982 announced a renewed active space effort, which included initiatives such the construction of Space Station Freedom, and the military Strategic Defense Initiative, and, later in his term, a 30 percent increase in NASA's budget. The Space Shuttle Challenger disaster in January 1986 led to a reevaluation of the future of the national space program in the National Commission on Space report and the Ride Report.
The United States has participated in the International Space Station beginning in the 1990s, the Space Shuttle program has continued, although the Space Shuttle Columbia disaster has led to the planned retirement of the Space Shuttle in mid-2011. There is a current debate on the post-Space Shuttle future of the civilian space program: the Constellation program of the George W. Bush administration directed NASA to create a set of new spacecraft with the goal of sending astronauts to the Moon and Mars, but the Obama administration cancelled the Constellation program, opting instead to emphasize development of commercial rocket systems.
The Vision for Space Exploration established under the George W. Bush administration in 2004 was replaced with a new policy released by Barack Obama on 28 June 2010.
In recent years, U.S. space operators and decisionmakers have become increasingly concerned about threats to U.S. space leadership. In the civil sector, this has been driven largely by U.S. dependence on Russia for crew access to the International Space Station (ISS) since the termination of the Space Shuttle program in 2011. In national security, foreign development of counterspace systems has become a regular feature of public statements by U.S. defense and intelligence officials. This is reminiscent of similar concerns about the Soviet Union's space program between the launch of Sputnik 1 in 1957 and the success of the Apollo lunar missions. The threat of Soviet dominance in space turned out to be less formidable than expected, but it continued to drive policy and programmatic decisions for decades, until the Soviet Union ceased to exist.
Europe
The European Space Agency (ESA) is the common space agency for many European nations. It is independent of the European Union, though the 2007 European Space Policy provides a framework for coordination between the two organizations and member states, including issues such as security and defence, access to space, space science, and space exploration.
The ESA was founded to serve as a counterweight to the dominant United States and Soviet space programs, and further the economic and military independence of Europe. This has included the development of the Ariane rockets, which by 1985 had captured over 40 percent of commercial launch market in the free world. The ESA budget is split between mandatory and voluntary programs, the latter of which allow individual member nations to pursue their own national space goals within the organization.
The ESA Director General's Proposal for the European Space Policy states, "Space systems are strategic assets demonstrating independence and the readiness to assume global responsibilities. Initially developed as defence or scientific projects, they now also provide commercial infrastructures on which important sectors of the economy depend and which are relevant in the daily life of citizens.... Europe needs an effective space policy to enable it to exert global leadership in selected policy areas in accordance with European interests and values."
In the final part of 2010s the ESA has made strong efforts in order to make Europe stronger in the competition for the development of new strategies regarding space policy. Those included a huge increase in ESA's budget promoted by countries such as Italy, France and Germany.
China
Although Chairman Mao Zedong planned after Russia's Sputnik 1 launch to place a Chinese satellite in orbit by 1959 to celebrate the 10th anniversary of the founding of the People's Republic of China (PRC), China did not successfully launch its first satellite until 24 April 1970. Mao and Zhou Enlai decided on 14 July 1967 that the PRC should not be left behind, and started China's own human spaceflight program. The first success came on 15 October 2003 when China sent its first astronaut into space for 21 hours aboard Shenzhou 5.
The Ministry of Aerospace Industry was responsible for the Chinese space program prior to July 1999, when it was split into the China National Space Administration responsible for setting policy, and the state-owned China Aerospace Science and Technology Corporation, responsible for implementation.
The China National Space Administration states its aims as maintaining the country's overall development strategy, making innovations in an independent and self-reliant manner, promoting the country's science and technology sector and encouraging economic and social development, and actively engaging in international cooperation.
Russia and Ukraine
Russia inherited its space programs in 1991 from its predecessor state, the Soviet Union. Russia's civilian space agency is the Russian Federal Space Agency and its military counterpart is the Russian Aerospace Defence Forces. Ukraine's agency is the State Space Agency of Ukraine, which handles both civilian and military programs.
The Soviet Union became the world's first spacefaring state by launching its first satellite, Sputnik 1, on 4 October 1957. The Soviet space program was active from 1955 until the dissolution of the Soviet Union in 1991.
In the 1980s the Soviet Union was considered to be technologically behind the United States, but it outspent the United States in its space budget, and its cosmonauts had spent three times as many days in space as American astronauts. The Soviet Union had also been more willing than the United States to embark on long-term programs, such as the Salyut and Mir space station programs, and increased their investment in space programs throughout the 1970s and 1980s.
After the dissolution of the Soviet Union, the 1990s saw serious financial problems because of the decreased cash flow, which encouraged Roskosmos to improvise and seek other ways to keep space programs running. This resulted in Roskosmos' leading role in commercial satellite launches and space tourism. While scientific missions, such as interplanetary probes or astronomy missions during these years played a very small role, although Roskosmos has connections with Russian aerospace forces, its budget is not part of the defense budget of the country, Roskosmos managed to operate the space station Mir well past its planned lifespan, contribute to the International Space Station, and continue to fly additional Soyuz and Progress missions.
The Russian economy boomed throughout 2005 from high prices for exports, such as oil and gas, and the outlook for subsequent funding became more favorable. The federal space budget for the year 2009 was left unchanged despite the global economic crisis, standing at around 82 billion rubles ($2.4 billion). Current priorities of the Russian space program include the new Angara rocket family and development of new communications, navigation and remote Earth sensing spacecraft. The GLONASS global navigation satellite system has for many years been one of the top priorities and has been given its own budget line in the federal space budget.
India
The purpose of India's space program was outlined by Vikram Sarabhai (regarded as the father of the Indian space program):
The Department of Space (DoS) is the Indian government department responsible for administration of the Indian space program. It manages several agencies and institutes related to space exploration and space technologies. The Indian space program under the DoS aims to promote the development and application of space science and technology for the socio-economic benefit of the country. It includes two major satellite systems, INSAT for communication, television broadcasting and meteorological services, and Indian Remote Sensing Satellites (IRS) system for resources monitoring and management. It has also developed two satellite launch vehicles, Polar Satellite Launch Vehicle (PSLV) and Geosynchronous Satellite Launch Vehicle (GSLV), to place IRS and INSAT class satellites in orbit.
See also
Chinese exclusion policy of NASA
Citizens' Advisory Council on National Space Policy
Politics of outer space
Space advocacy
Space Generation Advisory Council
Space law
Space Race
References
External links
European Space Policy Institute
Space Policy – Academic Journal
Space Policy Resource Websites
Center for Space Policy and Strategy at The Aerospace Corporation
US Space Policy Archive – collected by the Center for Space Policy and Strategy
Space Security Portal at the United Nations Institute for Disarmament Research
Space Policy - Outer Space Policy, Politics and Law – Blog by Dr Jill Stuart
Astropolitics
Politics of science
Articles containing video clips | Space policy | [
"Astronomy"
] | 3,729 | [
"Outer space",
"Astropolitics"
] |
14,432,630 | https://en.wikipedia.org/wiki/John%20Ulric%20Nef%20%28chemist%29 | John Ulric Nef (née Johann Ulrich Nef; June 14, 1862 – August 13, 1915) was a Swiss-born American chemist and the discoverer of the Nef reaction and Nef synthesis. He was a member of the American Academy of Arts and Sciences and the National Academy of Sciences.
Life
His parents emigrated from Switzerland to the United States, where Nef studied chemistry at Harvard University until 1884. Upon graduation, he joined Adolf von Baeyer at the University of Munich, where he received his Ph.D. in 1887.
He was a professor at Purdue University from 1887 till 1889 and at Clark University from 1889 till 1892. In 1892 Nef joined the newly formed University of Chicago as professor of chemistry, where he spent the rest of his academic career. He died in Carmel-by-the-Sea, California on August 13, 1915.
His son John Ulric Nef (1899–1988) became a professor of economic history and published several books.
Work
The discovery of the Nef reaction and the papers about divalent carbon (carbenes) were his major achievements.
See also
Phenylsodium
References
Biographical Note from the University of Chicago
Picture of Nef at MSU
External links
Swiss emigrants to the United States
Harvard College alumni
Ludwig Maximilian University of Munich alumni
Purdue University faculty
Clark University faculty
University of Chicago faculty
1862 births
1915 deaths
American chemists
Organic chemists
Members of the Royal Society of Sciences in Uppsala | John Ulric Nef (chemist) | [
"Chemistry"
] | 293 | [
"Organic chemists"
] |
14,432,911 | https://en.wikipedia.org/wiki/Puppet%20%28software%29 | Puppet is a software configuration management tool developed by Puppet Inc., which is owned by Perforce, which is owned in turn by private equity firms. Puppet is used to manage stages of the IT infrastructure lifecycle.
Puppet uses an open-core model; its free-software version was released under version 2 of the GNU General Public License (GPL) until version 2.7.0, and later releases use the Apache License, while Puppet Enterprise uses a proprietary license.
Puppet and Puppet Enterprise operate on multiple Unix-like systems (including Linux, Solaris, BSD, Mac OS X, AIX, HP-UX) and has Microsoft Windows support. Puppet itself is written in Ruby. Facter, Puppet’s cross-platform system profiling library, is written in C++. Puppet Server and Puppet DB are written in Clojure.
Design
Puppet consists of a custom declarative language to describe system configuration.
Puppet is model-driven, requiring limited programming knowledge to use.
Puppet is designed to manage the configuration of Unix-like and Microsoft Windows systems declaratively.
Architecture
Puppet follows client-server architecture. The client is known as an agent and the server is known as the master. For testing and simple configuration, it can also be used as a stand-alone application run from the command line.
Puppet Server is installed on one or more servers, and Puppet Agent is installed on all the machines to be managed. Puppet Agents communicate with the server and fetch configuration instructions. The Agent then applies the configuration on the system and sends a status report to the server.
Puppet resource syntax:
type { 'title':
attribute => value
}
Example resource representing a Unix user:
user { 'harry':
ensure => present,
uid => '1000',
shell => '/bin/bash',
home => '/home/harry'
}
Vendor and Perforce Acquisition
Puppet's vendor, Puppet Inc., is a privately held information technology (IT) automation software company based in Portland, Oregon, USA.
In 2005, Puppet was founded by former CEO Luke Kanies. On Jan. 29, 2019 Yvonne Wassenaar replaced Sanjay Mirchandani as CEO. Wassenaar previously worked at Airware, New Relic and VMware. In February 2011 Puppet released its first commercial product, Puppet Enterprise, built on its open-source base, with some extra commercial components. Puppet purchased the infrastructure automation firm Distelli in September 2017. Puppet rebranded Distelli's VM Dashboard (a continuous integration / continuous delivery product) as Puppet Pipelines for Applications, and K8s Dashboard as Puppet Pipelines for Containers. The products were made generally available in October, 2017. In May 2018, Puppet released Puppet Discovery, a tool to discover and manipulate resources in hybrid networks. In June 2018, Puppet raised an additional $42 million for a total of $150 million in funding. The round was led by Cisco and included Kleiner Perkins, True Ventures, EDBI, and VMware. Puppet's partners include VMware, Amazon Web Services, Cisco, OpenStack, Microsoft Azure, Eucalyptus, and Zenoss.
In April 2022, it was announced Puppet had been acquired by the Minneapolis-headquartered software developer, Perforce. The company subsequently laid off 15% of Puppet's workforce in Portland.
See also
Comparison of open-source configuration management software
CFEngine
References
External links
Companies based in Portland, Oregon
American companies established in 2005
Privately held companies based in Oregon
Information technology companies of the United States
2005 establishments in Oregon
Software companies established in 2005
2005 software
Orchestration software
Configuration management
Cross-platform free software
Free software programmed in Ruby
Software using the Apache license
Virtualization software for Linux | Puppet (software) | [
"Engineering"
] | 760 | [
"Systems engineering",
"Configuration management"
] |
14,432,955 | https://en.wikipedia.org/wiki/Helianthus%20%C3%97%20laetiflorus | Helianthus × laetiflorus, the cheerful sunflower or perennial sunflower, is a plant in the family of Asteraceae. It is widespread in scattered locations across much of Canada from Newfoundland to British Columbia, and the central and eastern United States as far south as Texas and Georgia. This species is also commonly cultivated and may escape cultivation and be found in areas outside of its core range.
Description
Helianthus × laetiflorus is a herbaceous plant with alternate, simple leaves, on green stems. The flowers are yellow, borne in late summer. This species is generally considered to be of hybrid origin, with the two parental species being Helianthus tuberosus and Helianthus pauciflorus.
References
laetiflorus
Hybrid plants
Flora of Northern America
Plants described in 1807 | Helianthus × laetiflorus | [
"Biology"
] | 164 | [
"Hybrid plants",
"Plants",
"Hybrid organisms"
] |
14,433,355 | https://en.wikipedia.org/wiki/E-puck%20mobile%20robot | The e-puck is a small (7 cm) differential wheeled mobile robot. It was originally designed for micro-engineering education by Michael Bonani and Francesco Mondada at the ASL laboratory of Prof. Roland Siegwart at EPFL (Lausanne, Switzerland).
The e-puck is open hardware and its onboard software is open-source, and is built and sold by several companies.
Technical details
Diameter: 70 mm
Height: 50 mm
Weight: 200 g
Max speed: 13 cm/s
Autonomy: 2 hours moving
dsPIC 30 CPU @ 30 MHz (15 MIPS)
8 KB RAM
144 KB Flash
2 step motors
8 infrared proximity and light (TCRT1000)
color camera, 640x480
8 LEDs in ring + one body LED + one front LED
3D accelerometers
3 microphones
1 loudspeaker
Extensions
New modules can be stacked on top of the e-puck; the following extensions are available:
a turret that simulates 1D omnidirectional vision, to study optic flow,
ground sensors, for instance to follow a line,
color LED turret, for color-based communication,
Zigbee communication,
2D omnidirectional vision,
magnetic wheels, for vertical climbing,
Pi-puck extension board, for interfacing with a Raspberry Pi single-board computer.
Scientific use
Since the e-puck is open hardware, its price is lower than competitors. This is leading to a rapid adoption by the scientific community in research despite the original educational orientation of the robot.
The e-puck has been used in collective robotics , evolutionary robotics , and art-oriented robotics .
References
External links
Homepage - the e-puck project homepage
e-puck at Mobots - the e-puck homepage at Mobots, the group who developed the e-puck
e-puck at gna - the gna page of e-puck onboard software
e-puck model - Documentation of the e-puck model in the Webots robotics simulator.
Cyberbotics' robot curriculum - a robotics curriculum based on the e-puck robot
- epuck2 MATLAB kernel
Micro robots
Robots of Switzerland
Differential wheeled robots
Open-source robots
Multi-robot systems | E-puck mobile robot | [
"Materials_science"
] | 450 | [
"Micro robots",
"Microtechnology"
] |
14,433,598 | https://en.wikipedia.org/wiki/Quadratic%20residue%20code | A quadratic residue code is a type of cyclic code.
Examples
Examples of quadratic
residue codes include the Hamming code
over , the binary Golay code
over and the ternary Golay code
over .
Constructions
There is a quadratic residue code of length
over the finite field whenever
and are primes, is odd, and
is a quadratic residue modulo .
Its generator polynomial as a cyclic code is given by
where is the set of quadratic residues of
in the set and
is a primitive th root of
unity in some finite extension field of .
The condition that is a quadratic residue
of ensures that the coefficients of
lie in . The dimension of the code is
.
Replacing by another primitive -th
root of unity either results in the same code
or an equivalent code, according to whether or not
is a quadratic residue of .
An alternative construction avoids roots of unity. Define
for a suitable . When
choose to ensure that .
If is odd, choose ,
where or according to whether
is congruent to or
modulo . Then also generates
a quadratic residue code; more precisely the ideal of
generated by
corresponds to the quadratic residue code.
Weight
The minimum weight of a quadratic residue code of length
is greater than ; this is the square root bound.
Extended code
Adding an overall parity-check digit to a quadratic residue code
gives an extended quadratic residue code. When
(mod ) an extended quadratic
residue code is self-dual; otherwise it is equivalent but not
equal to its dual. By the Gleason–Prange theorem (named for Andrew Gleason and Eugene Prange), the automorphism group of an extended quadratic residue
code has a subgroup which is isomorphic to
either or .
Decoding Method
Since late 1980, there are many algebraic decoding algorithms were developed for correcting errors on quadratic residue codes. These algorithms can achieve the (true) error-correcting capacity of the quadratic residue codes with the code length up to 113. However, decoding of long binary quadratic residue codes and non-binary quadratic residue codes continue to be a challenge. Currently, decoding quadratic residue codes is still an active research area in the theory of error-correcting code.
References
F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, North-Holland Publishing Co., Amsterdam-New York-Oxford, 1977.
.
M. Elia, Algebraic decoding of the (23,12,7) Golay code, IEEE Transactions on Information Theory, Volume: 33, Issue: 1, pg. 150-151, January 1987.
Reed, I.S., Yin, X., Truong, T.K., Algebraic decoding of the (32, 16, 8) quadratic residue code. IEEE Trans. Inf. Theory 36(4), 876–880 (1990)
Reed, I.S., Truong, T.K., Chen, X., Yin, X., The algebraic decoding of the (41, 21, 9) quadratic residue code. IEEE Trans. Inf. Theory 38(3), 974–986 (1992)
Humphreys, J.F. Algebraic decoding of the ternary (13, 7, 5) quadratic-residue code. IEEE Trans. Inf. Theory 38(3), 1122–1125 (May 1992)
Chen, X., Reed, I.S., Truong, T.K., Decoding the (73, 37, 13) quadratic-residue code. IEE Proc., Comput. Digit. Tech. 141(5), 253–258 (1994)
Higgs, R.J., Humphreys, J.F.: Decoding the ternary (23, 12, 8) quadratic-residue code. IEE Proc., Comm. 142(3), 129–134 (June 1995)
He, R., Reed, I.S., Truong, T.K., Chen, X., Decoding the (47, 24, 11) quadratic residue code. IEEE Trans. Inf. Theory 47(3), 1181–1186 (2001)
….
Y. Li, Y. Duan, H. C. Chang, H. Liu, T. K. Truong, Using the difference of syndromes to decode quadratic residue codes, IEEE Trans. Inf. Theory 64(7), 5179-5190 (2018)
Quadratic residue
Coding theory | Quadratic residue code | [
"Mathematics"
] | 953 | [
"Discrete mathematics",
"Coding theory"
] |
14,433,672 | https://en.wikipedia.org/wiki/James%20R.%20Robinson | James R. Robinson (1860–1950) was a Scottish-born American industrialist, inventor, and author of a seminal book on mine ventilation (1922). The book documents his invention of a new device for ventilating mines and preventing the build-up of explosive methane gas underground, thereby dramatically improving mine safety.
He founded the Robinson Ventilating Company, forerunner of today’s Robinson Industries, one of the United States' leading designers and manufacturers of industrial fans.
Early life
J.R. Robinson was born in Scotland where his father, Samuel B. Robinson, worked as a master mechanic for the English Crown Coal Company. In 1863, when Robinson was three, his family emigrated to the United States, settling in the coal country of western Pennsylvania. Upon his arrival in the U.S., Samuel enlisted in the Union Army to fight in the Civil War. When the war ended, he used his coal mining skills to land a job as a designer for the Pittsburgh Coal Company, eventually rising to the position of plant superintendent.
By the time he was 12, Robinson was helping his father in the coal mine, earning certification as a journeyman machinist by the time he was 20.
Education and New Ventures
Robinson studied mechanical engineering at Cornell University, after which he returned to Pennsylvania. In 1892 he and Samuel co-founded the Robinson Machine Company, which provided machinery and ventilation for the many mines in the region. J.R. served as chief engineer. In that capacity he directed numerous product innovations, including the development of fans, steam boilers, engines, hoists, crushers, and haulers for coal mines and mills.
In 1907 Samuel retired and sold the company. The following year, James founded the Robinson Ventilating Company in Pittsburgh, which sold industrial fans that he designed and were manufactured by two other companies.
America’s entry into World War I in 1917 placed heavy demands on the nation’s manufacturers, leading Robinson Ventilating to establish its own manufacturing plant in Blairsville, Pa. In 1921, Robinson moved the plant to Zelienople, Pa., where the headquarters and main manufacturing facility of Robinson Industries are still located today.
Legacy
As a result of his work with the mining industry, Robinson became a major authority on mine ventilation. Until the early 1900s, the principal method of providing ventilation for miners was through "natural draft ventilation," which meant simply digging large holes above the mines for ventilation purposes. The problem with this was that methane gases were too heavy to rise through the ventilating holes, and instead accumulated beneath the surface, often triggering explosions. He designed and built a ventilating device that could bring fresh air into mines or force out old air. He summarized his work in a technical article and in his 1922 book Practical Mine Ventilation, which quickly became required reading in college mining and engineering classes. The book remained a staple of course syllabi for many years afterward. It is still held in roughly 30 U.S. libraries.
Robinson’s innovations were not limited to the ventilation industry. On a winter’s day in 1927, while driving to Penn State University to visit his son Rodger, he experienced a great deal of difficulty seeing through the snow and ice accumulating on his windshield. Rather than returning home after his visit he stayed at the university and used his engineering expertise to design and create a device for heating windshields, which he later patented.
To ensure that the company would stay in the family, he placed the majority of Robinson Ventilating stock in a trust for his children. Many of his children and their descendants have remained in the business and have helped to grow it and make technical innovations.
References
External links
Timeline of Robinson Industries, Inc.
American inventors
1950 deaths
1860 births
Cornell University alumni
Mining engineers
Scottish emigrants to the United States | James R. Robinson | [
"Engineering"
] | 771 | [
"Mining engineering",
"Mining engineers"
] |
14,433,872 | https://en.wikipedia.org/wiki/PRKAR1A | cAMP-dependent protein kinase type I-alpha regulatory subunit is an enzyme that in humans is encoded by the PRKAR1A gene.
Function
cAMP is a signaling molecule important for a variety of cellular functions. cAMP exerts its effects by activating the cAMP-dependent protein kinase A (PKA), which transduces the signal through phosphorylation of different target proteins. The inactive holoenzyme of PKA is a tetramer composed of two regulatory and two catalytic subunits. cAMP causes the dissociation of the inactive holoenzyme into a dimer of regulatory subunits bound to four cAMP and two free monomeric catalytic subunits. Four different regulatory subunits and three catalytic subunits of PKA have been identified in humans. The protein encoded by this gene is one of the regulatory subunits. This protein was found to be a tissue-specific extinguisher that downregulates the expression of seven liver genes in hepatoma x fibroblast hybrids Three alternatively spliced transcript variants encoding the same protein have been observed.
Clinical significance
Functional null mutations in this gene cause Carney complex (CNC), an autosomal dominant multiple neoplasia syndrome. This gene can fuse to the RET protooncogene by gene rearrangement and form the thyroid tumor-specific chimeric oncogene known as PTC2.
Mutation of PRKAR1A leads to the Carney complex, associating multiple endocrine tumors.
Interactions
PRKAR1A has been shown to interact with:
AKAP10,
AKAP1,
AKAP4,
ARFGEF1,
ARFGEF2,
Grb2,
MYO7A,
PRKAR1B, and
UBE2M.
See also
cAMP-dependent protein kinase
References
Further reading
External links
PDBe-KB provides an overview of all the structure information available in the PDB for Human cAMP-dependent protein kinase type I-alpha regulatory subunit (PRKAR1A)
Signal transduction | PRKAR1A | [
"Chemistry",
"Biology"
] | 417 | [
"Biochemistry",
"Neurochemistry",
"Signal transduction"
] |
14,434,367 | https://en.wikipedia.org/wiki/Fluid%20compartments | The human body and even its individual body fluids may be conceptually divided into various fluid compartments, which, although not literally anatomic compartments, do represent a real division in terms of how portions of the body's water, solutes, and suspended elements are segregated. The two main fluid compartments are the intracellular and extracellular compartments. The intracellular compartment is the space within the organism's cells; it is separated from the extracellular compartment by cell membranes.
About two-thirds of the total body water of humans is held in the cells, mostly in the cytosol, and the remainder is found in the extracellular compartment. The extracellular fluids may be divided into three types: interstitial fluid in the "interstitial compartment" (surrounding tissue cells and bathing them in a solution of nutrients and other chemicals), blood plasma and lymph in the "intravascular compartment" (inside the blood vessels and lymphatic vessels), and small amounts of transcellular fluid such as ocular and cerebrospinal fluids in the "transcellular compartment".
The normal processes by which life self-regulates its biochemistry (homeostasis) produce fluid balance across the fluid compartments. Water and electrolytes are continuously moving across barriers (eg, cell membranes, vessel walls), albeit often in small amounts, to maintain this healthy balance. The movement of these molecules is controlled and restricted by various mechanisms. When illnesses upset the balance, electrolyte imbalances can result.
The interstitial and intravascular compartments readily exchange water and solutes, but the third extracellular compartment, the transcellular, is thought of as separate from the other two and not in dynamic equilibrium with them.
The science of fluid balance across fluid compartments has practical application in intravenous therapy, where doctors and nurses must predict fluid shifts and decide which IV fluids to give (for example, isotonic versus hypotonic), how much to give, and how fast (volume or mass per minute or hour).
Intracellular compartment
The intracellular fluid (ICF) is all fluids contained inside the cells, which consists of cytosol and fluid in the cell nucleus. The cytosol is the matrix in which cellular organelles are suspended. The cytosol and organelles together compose the cytoplasm. The cell membranes are the outer barrier. In humans, the intracellular compartment contains on average about of fluid, and under ordinary circumstances remains in osmotic equilibrium. It contains moderate quantities of magnesium and sulfate ions.
In the cell nucleus, the fluid component of the nucleoplasm is called the nucleosol.
Extracellular compartment
The interstitial, intravascular and transcellular compartments comprise the extracellular compartment. Its extracellular fluid (ECF) contains about one-third of total body water.
Intravascular compartment
The main intravascular fluid in mammals is blood, a complex mixture with elements of a suspension (blood cells), colloid (globulins), and solutes (glucose and ions). The blood represents both the intracellular compartment (the fluid inside the blood cells) and the extracellular compartment (the blood plasma). The average volume of plasma in the average () male is approximately . The volume of the intravascular compartment is regulated in part by hydrostatic pressure gradients, and by reabsorption by the kidneys.
Interstitial compartment
The interstitial compartment (also called "tissue space") surrounds tissue cells. It is filled with interstitial fluid, including lymph. Interstitial fluid provides the immediate microenvironment that allows for movement of ions, proteins and nutrients across the cell barrier. This fluid is not static, but is continually being refreshed by the blood capillaries and recollected by lymphatic capillaries. In the average male () human body, the interstitial space has approximately of fluid.
Transcellular compartment
The transcellular fluid is the portion of total body fluid that is formed by the secretory activity of epithelial cells and is contained within specialized epithelial-lined compartments. Fluid does not normally collect in larger amounts in these spaces, and any significant fluid collection in these spaces is physiologically nonfunctional. Examples of transcellular spaces include the eye, the central nervous system, the peritoneal and pleural cavities, and the joint capsules. A small amount of fluid, called transcellular fluid, does exist normally in such spaces. For example, the aqueous humor, the vitreous humor, the cerebrospinal fluid, the serous fluid produced by the serous membranes, and the synovial fluid produced by the synovial membranes are all transcellular fluids. They are all very important, yet there is not much of each. For example, there is only about of cerebrospinal fluid in the entire central nervous system at any moment. All of the above-mentioned fluids are produced by active cellular processes working with blood plasma as the raw material, and they are all more or less similar to blood plasma except for certain modifications tailored to their function. For example, the cerebrospinal fluid is made by various cells of the CNS, mostly the ependymal cells, from blood plasma.
Fluid shift
Fluid shifts occur when the body's fluids move between the fluid compartments. Physiologically, this occurs by a combination of hydrostatic pressure gradients and osmotic pressure gradients. Water will move from one space into the next passively across a semi permeable membrane until the hydrostatic and osmotic pressure gradients balance each other. Many medical conditions can cause fluid shifts. When fluid moves out of the intravascular compartment (the blood vessels), blood pressure can drop to dangerously low levels, endangering critical organs such as the brain, heart and kidneys; when it shifts out of the cells (the intracellular compartment), cellular processes slow down or cease from intracellular dehydration; when excessive fluid accumulates in the interstitial space, oedema develops; and fluid shifts into the brain cells can cause increased cranial pressure. Fluid shifts may be compensated by fluid replacement or diuretics.
Third spacing
"Third spacing" is the abnormal accumulation of fluid into an extracellular and extravascular space. In medicine, the term is often used with regard to loss of fluid into interstitial spaces, such as with burns or edema, but it can also refer to fluid shifts into a body cavity (transcellular space), such as ascites and pleural effusions. With regard to severe burns, fluids may pool on the burn site (i.e. fluid lying outside of the interstitial tissue, exposed to evaporation) and cause depletion of the fluids. With pancreatitis or ileus, fluids may "leak out" into the peritoneal cavity, also causing depletion of the intracellular, interstitial or vascular compartments.
Patients who undergo long, difficult operations in large surgical fields can collect third-space fluids and become intravascularly depleted despite large volumes of intravenous fluid and blood replacement.
The precise volume of fluid in a patient's third spaces changes over time and is difficult to accurately quantify.
Third spacing conditions may include peritonitis, pyometritis, and pleural effusions. Hydrocephalus and glaucoma are theoretically forms of third spacing, but the volumes are too small to induce significant shifts in blood volumes, or overall body volumes, and thus are generally not referred to as third spacing.
See also
Blood–brain barrier
Compartment (pharmacokinetics)
Distribution (pharmacology) and volume of distribution
References
Physiology
Cell biology | Fluid compartments | [
"Biology"
] | 1,621 | [
"Cell biology",
"Physiology"
] |
14,434,713 | https://en.wikipedia.org/wiki/Operation%20CHASE | Operation CHASE (an acronym for "Cut Holes And Sink 'Em") was a United States Department of Defense program for the disposal of unwanted munitions at sea from May 1964 until the early 1970s. Munitions were loaded onto ships to be scuttled once they were at least 250 miles (400 km) offshore. While most of the sinkings involved conventional weapons, four of them involved chemical weapons. The disposal site for the chemical weapons was a three-mile (5 km) area of the Atlantic Ocean between the coast of the U.S. state of Florida and the Bahamas. Other weapons were disposed of in various locations in the Atlantic and Pacific oceans. The CHASE program was preceded by the United States Army disposal of 8,000 short tons of mustard and lewisite chemical warfare gas aboard the scuttled SS William C. Ralston in April 1958. These ships were sunk by having Explosive Ordnance Disposal (EOD) teams open seacocks on the ship after they arrived at the disposal site. The typical Liberty ship sank about three hours after the seacocks were opened.
Operations
CHASE 1
The mothballed C-3 Liberty ship John F. Shafroth was taken from the National Defense Reserve Fleet at Suisun Bay and towed to the Concord Naval Weapons Station for stripping and loading. A major fraction of the munitions in CHASE 1 was Bofors 40 mm gun ammunition from the Naval Ammunition Depot at Hastings, Nebraska. CHASE 1 also included bombs, torpedo warheads, naval mines, cartridges, projectiles, fuzes, detonators, boosters, overage UGM-27 Polaris motors, and a quantity of contaminated cake mix an army court had ordered dumped at sea. Shafroth was sunk 47 miles (76 km) off San Francisco on 23 July 1964 with 9,799 tons of munitions.
CHASE 2
Village was loaded with 7,348 short tons of munitions at the Naval Weapons Station Earle and towed to a deep-water dump site on 17 September 1964. There were three large and unexpected detonations five minutes after Village slipped beneath the surface. An oil slick and some debris appeared on the surface. The explosion registered on seismic equipment all over the world. Inquiries were received regarding seismic activity off the east coast of the United States, and the Office of Naval Research and Advanced Research Projects Agency expressed interest in measuring the differences between seismic shocks and underwater explosive detonations to detect underwater nuclear detonations then banned by treaty.
CHASE 3
Coastal Mariner was loaded with 4040 short tons of munitions at the Naval Weapons Station Earle. The munitions included 512 tons of explosives. Four SOFAR bombs were packed in the explosives cargo hold with booster charges of 500 pounds (227 kg) of TNT to detonate the cargo at a depth of 1,000 feet (300 m). The United States Coast Guard issued a notice to mariners and the United States Department of Fish and Wildlife and the United States Bureau of Commercial Fisheries sent observers. The explosives detonated seventeen seconds after Coastal Mariner slipped below the surface on 14 July 1965. The detonation created a 600-foot (200 m) waterspout but was not deep enough to be recorded on seismic instruments.
CHASE 4
Santiago Iglesias was loaded with 8,715 tons of munitions at the Naval Weapons Station Earle, rigged for detonation at 1,000 feet (300 m), and detonated 31 seconds after sinking on 16 September 1965.
CHASE 5
Isaac Van Zandt was loaded with 8,000 tons of munitions (including 400 tons of high explosives) at the Naval Base Kitsap and rigged for detonation at 4,000 feet (1.2 km). On 23 May 1966 the tow cable parted en route to the planned disposal area. Navy tugs USS Tatnuck (ATA-195) and USS Koka (ATA-185) recovered the tow within six hours, but the location of sinking was changed by the delay.
CHASE 6
Different sources describe CHASE 6 differently. Naval Institute Proceedings indicates Horace Greeley was loaded at the Naval Weapons Station Earle, rigged for detonation at 4,000 feet (1.2 km), and detonated on 28 July 1966. Other sources describe CHASE 6 as the Liberty ship Robert Louis Stevenson loaded with 2,000 tons of explosives at Naval Base Kitsap in July 1967 as part of the ONR and ARPA investigation to detect underwater nuclear tests. Robert Louis Stevenson failed to sink as rapidly as had been predicted and drifted into water too shallow to actuate the hydrostatic-pressure detonators. The tug Tatnuck involved in towing Robert Louis Stevenson was reported by Proceedings as towing Izaac Van Zandt a year earlier for CHASE 5.
CHASE 7
Michael J. Monahan was loaded with overage UGM-27 Polaris motors at the Naval Weapons Station Charleston and sunk without detonation on 30 April 1967.
CHASE 8
The first chemical weapons disposal via the program was in 1967 and designated CHASE 8. CHASE 8 disposed of mustard gas and GB-filled M-55 rockets. All of the cargo was placed aboard a merchant hulk (the S.S. Corporal Eric G. Gibson) and was then sunk in deep water off the continental shelf.
CHASE 9
Eric G. Gibson was sunk on 15 June 1967.
CHASE 10
CHASE 10 dumped 3,000 tons of United States Army nerve agent filled rockets encased in concrete vaults. The ship used was the LeBaron Russell Briggs.
Public controversy delayed CHASE 10 disposal until August 1970. Public awareness of operation CHASE 10 was increased by mass media reporting following delivery of information from the Pentagon to the office of U.S. Representative Richard McCarthy in 1969. Both American television and print media followed the story with heavy coverage. In 1970, 58 separate reports were aired on the three major network news programs on NBC, ABC and CBS concerning Operation CHASE. Similarly, The New York Times included Operation CHASE coverage in 42 separate issues during 1970, 21 of those in the month of August. The publicity played a role in ending the practice of dumping chemical weapons at sea.
CHASE 11
CHASE 11 occurred in June 1968 and disposed of United States Army GB and VX, all sealed in tin containers.
CHASE 12
CHASE 12, in August 1968, again disposed of United States Army mustard agent and was numerically (although not chronologically) the final mission to dispose of chemical weapons.
Aftermath
Operation CHASE was exposed to the public during a time when the army, especially the Chemical Corps, was under increasing public criticism. CHASE was one of the incidents which led to the near disbanding of the Chemical Corps in the aftermath of the Vietnam War. Concerns were raised over the program's effect on the ocean environment as well as the risk of chemical weapons washing up on shore. The concerns led to the Marine Protection, Research, and Sanctuaries Act of 1972, which prohibited such future missions. After a treaty was drafted by the United Nations' London Convention in 1972, an international ban came into effect as well.
See also
Dugway sheep incident
Operation Red Hat
References
Chase
Chemical weapons demilitarization
Ocean pollution
Military projects of the United States
Chase | Operation CHASE | [
"Chemistry",
"Engineering",
"Environmental_science"
] | 1,434 | [
"Ocean pollution",
"Military projects",
"Chemical weapons",
"Chemical weapons demilitarization",
"Water pollution",
"Military projects of the United States"
] |
14,435,572 | https://en.wikipedia.org/wiki/Suppressor%20of%20cytokine%20signaling%201 | Suppressor of cytokine signaling 1 is a protein that in humans is encoded by the SOCS1 gene. SOCS1 orthologs have been identified in several mammals for which complete genome data are available.
Function
This gene encodes a member of the STAT-induced STAT inhibitor (SSI), also known as suppressor of cytokine signalling (SOCS), family. SSI family members are cytokine-inducible negative regulators of cytokine signaling. The expression of this gene can be induced by a subset of cytokines, including IL2, IL3, erythropoietin (EPO), GM-CSF, and interferon-gamma (IFN-γ). The protein encoded by this gene functions downstream of cytokine receptors, and takes part in a negative feedback loop to attenuate cytokine signaling. Knockout studies in mice suggested the role of this gene as a modulator of IFN-γ action, which is required for normal postnatal growth and survival.
Several recent viral studies have shown that viral genes, such as Tax gene product (Tax), encoded by HTLV-1, could hijack SOCS1 to inhibit host antiviral pathways, as a strategy to evade host immunity.
Interactions
The suppressor of cytokine signaling 1 has been shown to interact with:
Tax,
CD117,
Colony stimulating factor 1 receptor
Growth hormone receptor,
IRS2,
Janus kinase 2, and
TEC.
See also
SOCS
JAK-STAT signaling pathway
References
Further reading
Cell signaling
Signal transduction | Suppressor of cytokine signaling 1 | [
"Chemistry",
"Biology"
] | 329 | [
"Biochemistry",
"Neurochemistry",
"Signal transduction"
] |
14,435,941 | https://en.wikipedia.org/wiki/Amiga%20productivity%20software | This article deals with productivity software created for the Amiga line of computers and covers the AmigaOS operating system and its derivatives AROS and MorphOS. It is a split of the main article, Amiga software.
History
The Amiga originally supported such prestigious software titles as WordPerfect, Electronic Arts' Deluxe Paint, and Lattice C. Newtek's Video Toaster, one of the first all-in-one graphics and video editing packages, began on the Amiga. The Video Toaster was one of the few accessories for the "big box" Amigas (2000, 3000 and 4000) that used the video slot and enabled users to turn their Amiga into the heart of an entire TV production suite. The later addition of the Video Flyer by Newtek made possible the first non-linear video editing program for the Amiga. The Amiga made 3D raytracing graphics available for the masses with Sculpt 3D. Before the Amiga, raytracing was only available for dedicated graphic workstations such as the SGI. Impulse's TurboSilver was another of the few software packages designed to support raytracing. The Amiga was well known for its 3D rendering capability, with many titles being added to the mix as the years went by. Some titles were later ported to Microsoft Windows and continue to thrive there, such as the rendering software Cinema 4D from Maxon, and LightWave from Newtek, which was originally part of the Video Toaster. The Video Toaster itself has even been ported to the Windows platform. LightWave was used for low-cost computer-generated special effects during the early 1990s, with Babylon 5 being a notable example of a TV-series utilizing LightWave. Even Microsoft produced software for use on the Amiga. AmigaBASIC, an advanced BASIC software development environment, complete with an integrated development environment (IDE), was written by Microsoft under contract.
Graphics software
Amiga had its beginnings in 1985 with a strong attitude for graphics, with its unique hardware and multimedia chipset allowing for much greater graphical support and capability than other computers of the time. The Agnus graphical chip could directly access RAM and pilot it with DMA (Direct Memory Access) privileges, and featured Bit Blitter and Copper circuits capable of moving ranges of pixels on the screen and dealing directly with the electronic beam of the TV set. It could render graphic screens of various numbers of colors (2, 4, 8, 16, 32, 64, and 4096 color HAM modes) starting from 320x200 up to 720x576 pixel graphic pages. Amiga released a vast number of graphics software programs, such as Graphicraft, Deluxe Paint, TVPaint, Photon Paint, Brilliance!, (a program entirely realized upon the suggestions and wishes of well-known computer artist Jim Sachs), Aegis Images, ArtEffect, fxPAINT by IOSpirit, Personal Paint from Cloanto, Photogenics, Express Paint, Digi Paint, XiPaint, PerfectPaint, and SketchBlock 24 bit painting program by Andy Broad for AmigaOS 4.x.
Graphic applications on AmigaOne systems
Unlike Commodore Amiga systems, AmigaOne systems have no integrated multimedia chipsets. Instead these systems, similar to Mac or PC, sport AGP/PCIe graphic cards, embedded audio AC'97 sound system, and can use PCI/PCIe audio cards, even some professional models. The expanded capability of the system's faster CPU performance, and the availability of standard expansion graphic cards, lead to a new generation of graphic software being born for the AmigaOne machines such as Hollywood "Visual Programming Suite". This made it also easy to port modern open-source software like Blender3D.
Visual programming
The Hollywood suite of programs by German software house Airsoft SoftWair is a multimedia and presentation program available for all Amiga systems (AmigaOS, MorphOS, AROS) and recently , a version of Hollywood became available for Microsoft Windows as well. It is able to load Scala projects and Microsoft PowerPoint ".PPT" files. Its module Hollywood Designer is not only a modern multimedia authoring software but also a true complete cross-platform multimedia application layer capable of creating whole Amiga programs through a Visual design approach. It also can save executables in various formats: 68k Amiga, WarpUP, AmigaOS 4 and MorphOS executables, and Intel X86 code for AROS. Recent versions of Hollywood allow for creating executable programs for Intel Windows machines, as well as Mac OS X for both PPC and Intel processors.
Modern graphic software
There is some fairly modern graphic software available for AmigaOne machines. TV Paint was released in 1991, and was one of the first commercial 32-bit graphic software on the market. The latest Amiga version (3.59) was released in 1994 and distributed publicly, although the source code was kept proprietary. It remains a valid graphic program and continues to be used despite its age due to its ease of use and vast number of features. Programs like Candy Factory for AOS 4.0 are designed to create special effects for images, brushes, and fonts to create internet objects and buttons used in designing web pages. Pixel image editor (formerly Pixel32) is available for MorphOS. Blender 3D is one of the best open source cross-platform software. A first pre-release of GIMP is available on AmigaOS 4.0 through the AmiCygnix X11 graphic engine. Beginning with release 2.1 in 2008, MorphOS has included its own standard Paint utility called Sketch, simple but powerful, and AROS has bundled with the last free version of Luna Paint, which become actually a commercial paint program for various operating systems.
Graphic utilities
The Amiga software ecosystem included a wide variety of graphic utilities with peculiar features created in order to support main graphic programs. For example, Amiga systems supported many professional software utilities such as Cinematte, CineMorph, Morph Plus, Impact!, Essence, Magic Lantern, and Pixel 3D Pro, all of which were some of the most notorious entries in the vast range of graphic utilities that could be purchased by users of the Amiga platform. Cinematte allows the user to easily make complex photo-realistic composites of subjects that are photographed against a bluescreen, or green screen background. It uses the same sophisticated techniques as modern motion picture technology for precise bluescreen compositing. CineMorph is a program used to automatically create morphing effects between two given original images, and create a compound third image, or even all the animation movies associated with the morphing effect. Morph Plus performed the same effects as Cinemorph. Impact! created physics simulation in 3D scenes. Essence was a texture maker used to apply textures on the surfaces of objects created by 3D tracing programs. Amiga Magic Lantern was a true color animation compressor and player for the Amiga. Pixel 3D Pro was used to create models for 3D objects and save them in various 3D file formats, or to transform any model object from one 3D file format to another.
Vector graphics
The most widely used formats for vector graphics in Amiga are EPS and IFF DR2D. This originated from the fact that Amiga was the first platform that ran Ghostscript natively. IFF DR2D was the original standard for vector graphics generated by Amiga ProVector and was later adopted by other applications such as Art Expression and Professional Draw. Foremost used Amiga drawing and vector graphics utilities are Aegis Draw, ProDraw (Professional Draw) from Gold Disk Inc., DrawStudio, Art Expression, ProVector, and for some basic vector graphics, also the tools of Professional Page and PageStream are useful. The most modern vector graphics programs on Amiga are actually MindSpace 1.1, which is aimed mainly at design flowcharts, mindtables, UML and diagrams, and Steam Draw, a simple 2D vector paint program available for MorphOS.
Flash and SWF
SWFTools is a collection of command line programs to convert and save various raster(bitmap) image formats from and to Flash SWF vector animation format.
Tracing software
AmigaOS featured the widely used free distributable vector-to-graphics conversion facilities Autotrace, Potrace, and XTrace, which can run also in the AROS Amiga open source clone system and MorphOS Amiga-Like systems. The desktop publishing software PageStream comes bundled with a tracing software. The structured drawing program ProVector had an optional add-on tracing utility named StylusTracer.
DXF, EMF, SVG file formats
Various programs can read DXF (almost all Amiga CAD programs), EMF, SVG, CGM, GEM, WMF, an example of converting tool that reads many formats and outputs DR2D is the Amiga program MetaView. There also exists SVG Datatype support directly in the OS, on any program, allowing the user to load and save files in the SVG (Scalable Vector Graphics) format.
Computer aided design
At its beginning the Amiga was considered to offer the most powerful graphics platform available at a reasonable price. It had various CAD programs available for it, such as X-CAD, IntelliCAD, DynaCaDD, MaxonCAD, IntroCAD, and even programs to design and test electronic circuits, such as ElektroCAD.
Animation, comics and cartoons
Due to the peculiar multimedia capabilities of the Amiga as well as the features of the bit blitter circuit, it was capable of performing advanced animation and video authoring at a professional level in the 1980s and thus seeded the creation of a vast amount of software to fill this segment of the professional video editing market. For Amiga there were available animation programs such as Aegis Animator, Lights!Camera!Action!, DeLuxe Video, Disney Animation Studio, versions later than 3 of Deluxe Paint, The Director (a BASIC-like language oriented to animation), Scala, Vision from Commodore itself, VisualFX from ClassX, Adorage Multi Effect program from proDAD, Millennium from Nova Design. ImageFX, and Art Department Pro.
Comic Setter was a tool for creating printed comics by arranging brushes representing comic characters, joining it with background images, and superimposing it the right frames and "balloons" with their own text speech and captions. It could then print the comics that were created in color.
Disney Animation Studio was one of the most powerful 2D programs for realizing animation. released on Amiga, this program was equipped with a complete cell-frame preview feature which was used by many animation studios worldwide at the time and is still used by some studios in Europe as a preview tool. The software is mainly used for independent and amateur animators.
3D modeling, rendering and animation
Amiga 3D rendering and animation software includes Sculpt 3D, TurboSilver, Aladdin4D, Videoscape 3D, Caligari, Maxon Cinema4D, Imagine, LightWave from Newtek, Real3D from Realsoft, Vista Pro, World Construction Set 3D terrain rendering programs, and Tornado3D by the Italian company Eyelight.
Amateur and professional video editing
Amiga was one of the first commercial computer platforms to allow amateur and professional video editing, due to its capability to connect to TV sets and video codecs and deal with Chroma-Key, Genlock signal, at full screen with overscan features, and a good noise-gain ratio.
Amiga and its video peripherals (mainly Genlock boxes and digitizing boxes) in the nineties were available at reasonable prices and then this made the Amiga to become one of the professional video market leader platforms. It was also capable of dealing with broadcast video production (Newtek VideoToaster), and in the age around 1992–1994, despite the Commodore demise, Amiga knew its golden age as a professional video platform and there were available for Amiga a vast amount of any kind of video software, graphic facilities and reselling of any of GFX and image gallery data files that could be applied to video productions. Amongst this software it is worth mentioning the main Amiga video-editing programs for desktop video with both linear and non-linear editing with 4.2.2 capabilities as the ones from Newtek available with VideoToaster Flyer external module for Video Toaster and just called NLE! (Non Linear Editing), Amiga MainActor, Broadcaster 32 and Elite (with Producer software), Wildfire by Andreas Maschke for vfx (now in Java), expansion Amiga cards PAR, VLab Motion (with Movieshop software) and VLab Pro.
Word processing and page layout
While desktop video proved to be a major market for the Amiga, a surge of word processing, page layout and graphic software filled out the professional needs starting from the first Amiga text program, Textcraft, which was a mix between a real word processor and an advanced text editor, capable of changing page layouts, fonts, enlarging or reducing their width, changing their colors, and adding color images to the text.
Notable word processing programs for Amiga included the then-industry standard WordPerfect up to version 4.1, Shakespeare, Excellence, Maxon Word, Final Writer, Amiga Writer, Scribble!, ProWrite, Wordworth and the little Personal Write by Cloanto.
The page layout software included Page Setter and Professional Page from Gold Disk Inc., and PageStream by Soft-Logik, known today as Grasshopper LLC. Only PageStream was ported to other platforms and continues to be developed and supported by the developers. Graphic software included vector drawing applications like Art Expression from Soft-Logik, ProVector by Stylus, Inc. (formerly Taliesin), Draw Studio, and Professional Draw from Gold Disk Inc.
Amiga lacked an office suite as the term is meant now, but integrated software was available. Pen Pal was a word processor integrated with a database and a form editor. Scribble!, Analyze!, and Organize! were bundled together as the Works! suite combining a word processor, spreadsheet, and database. Despite the similarity in name, it had no connection to Microsoft Works.
The page layout language LaTeX was available in two ports: AmigaTeX, which is no longer available (the first LaTeX can be edited with a front-end program), and PasTEX, available on Aminet repository.
Modern software AbiWord is available today on AmigaOS 4.0 through the AmiCygnix X11 graphical engine, Scriba and Papyrus Office pre-release is available for MorphOS.
Text editors
Text editors available on Amiga include Vim, Emacs and MicroEMACS (included), Cygnus Editor also known as CED, and GoldED, which then evolved in 2006 into Cubic IDE. The UNIX ne editor and the vi-clone Vim were initially developed on the Amiga.
Development of Text editors never stopped in Amiga. Since 2001, in MorphOS, a limited edition version of GoldEd called MorphEd is available, and since 2008 Cinnamon Writer and NoWin ED, a universal editor which runs on any Amiga-like platform, are available. Cinnamon Writer is increasing new features to all new releases and aspires to become a full-featured WordProcessor.
Database and spreadsheets
In the first age of Amiga (1986–1989) there were cross-platform spreadsheets available, such as MaxiPlan, which was available also for MS-DOS and Macintosh. Logistix (stylized as LoGisTiX), one of the first spreadsheets for Amiga; Microfiche Filer Plus was a database that gave the user the experience of exploring data using microfilms. SuperBase was one of the finest programs available for C64. It was then ported on Atari, Amiga, and later on PC. But on Amiga, it would become a standard reference, available in two versions Superbase Personal and SuperBase Professional It could handle SQL databases and had a query internal language such as BASIC. It was capable of creating forms and masks on records and handling multimedia files into its records years before Microsoft Access. Superbase also featured VCR control style buttons to browse records of any database. Softwood File II was another simple multimedia database that then evolved into Final Data, a good database available for Amiga from Softwood Inc. From the same firm there was Final Calc, a very powerful spreadsheet, similar to TurboCalc from the German company Schatztruhe. ProChart was a tool to draw flow charts and diagrams. Analyze! was a fairly full-featured (for the time) spreadsheet developed for the Amiga. Organize! was a flat-file database package. Gnumeric spreadsheet has also been ported on Amiga through an X11 engine called AmiCygnix.
In recent times MUIbase was born and mainly cross-platform MySQL database language became a reference on Amiga also. SQLite, a self-contained, embeddable, zero-configuration SQL database engine, can also be found available on AmigaOS 4 and MorphOS.
In February 2010, Italian programmer Andrea Palmatè ported IODBC standard to AmigaOS 4.
Science, entertainment and special use programs
Maple V is one of the best general-purpose mathematics software (a.k.a. Mathematic-CAD) ever made. It was available for Amiga, and was appreciated by many scientists using Amiga in its time. Distant Suns, Galileo, Digital Almanac and Amiga Digital Universe (from Bill Eaves for the OS4) were stellar sky exploring programs and astronomic calculators. During the age of CDTV many historic, science, and art CDs like Timetable of Science, Innovation, Timetable of Business, Politics, Grolier's Encyclopedia, Guinness Disk of Records, Video Creator, American Heritage Dictionary, Illustrated Holy Bible, Illustrated Works of Shakespeare, etc. were available.
Entertainment
Amiga featured hundreds of entertainment software projects. Some notable programs for education and learning were Adventures in Math from Free Spirit Software, Animal Kingdom from Unicorn Software, Art School all the series of Barney Bear software, the Discovery series including Discovery trivia, Donald's Alphabet Chase, Mickey's 123's and Mickey's ABC's by Disney Software, the Electric Crayon and Ferngully series of educational coloring book software (Ferngully was taken from the animated feature film), Fun School series of disks, Kid Pix set of disks from the well known Broderbund Software house, which was famous in the nineties, Miracle Piano Teaching System to teach music to kids, various tales of Mother Goose, and World Atlas by Centaur Software.
Fractals, virtual reality, artificial intelligence
ZoneXplorer from Elena Novaretti is considered amongst Amiga users one of the best fractal experience programs ever made on Amiga, if not on any platform. In 1989 the X-Specs 3D Glasses from Haitex Resources, one of the first interactive 3D solutions for home computers were created. Also created on Amiga, were the multimedia interactive TV non-immersive Virtual reality exploring software Mandala from Vivid Group Inc., and the Virtuality System Virtuality 1000 CS 3D VRML all-immersive simulator from W-Industries (then Virtuality Inc.), for game entertainment in big arcade installations and theme parks, based on A3000.
Magellan v.1.1 (Artificial Intelligence Software), not to be confused with Directory Opus Magellan, was a program to emulate Artificial intelligence responses on Amiga, by creating heuristic programmed rules based on machine learning in its form of supervised learning. The user would choose into decision trees and decision tables system of AI featured by the Magellan program, in which to input objects, and desired outputs and describe all associate conditions and rules which the machine should follow in order to output pseudo-intelligent solutions to given problems.
Route planning
AmiATLAS v.6, was a complete Route planner tool for Amiga computers. It provided worldwide interactive maps and found optimal routes for traveling from one place to another. It also featured multiple map loading, an integrated CityGuide-System with information to interesting towns, places or regions, some even with pictures, and information about many parks and points of interest.
Personal organizer, notebook, diary software
Digita Organizer v.1.1 from Digita International was the best Amiga program to let the user to note about dates, meetings, remember expiry dates, etcetera. PolyOrga for MorphOS by Frédéric Rignault.
Personal budget, home banking, accounts
Easy Banker, Home Accounts, Small Business Accounts, Small Business Manager, Account Master, Accountant, AmigaMoney, Banca Base III, HomeBank, CashMaster, Counting House, etc.
Software for special purposes
AVT (Amiga Video Transceiver), was a software and hardware Slow-scan television system originally developed by "Black Belt Systems" (USA) around 1990 for the Amiga home computer popular all over the world before the IBM PC family gained sufficient audio quality with the help of special sound cards.
Richmond Sound Design (RSD) created both show control (a.k.a. MSC or "MIDI Show Control") and theatre sound design software which was used extensively in the theatre, theme park, display, exhibit, stage managing, show and themed entertainment industries in the 1980s and 1990s and at one point in the mid 90s, there were many high-profile shows at major theme parks around the world being controlled by Amigas through software simply called Stage Manager which then evolved into its Microsoft Windows version called ShowMan. There were dozens at Walt Disney World alone and more at all other Disney, Universal Studios, Six Flags and Madame Tussauds properties as well as in many venues in Las Vegas including The Mirage hotel Volcano and Siegfried and Roy show, the MGM Grand EFX show, Broadway theatre, London's West End, the Royal Shakespeare Company's many venues, most of Branson, Missouri's theatres, and scores of theatres on cruise ships, amongst hundreds of others. RSD purchased used Amigas on the web and reconditioned them to provide enough systems for all the shows that specified them and only stopped providing new Amiga installations in 2000. There are still an unknown number of shows on cruise ships and in themed venues being run by Amigas.
See also
Amiga Internet and communications software
Amiga music software
Amiga programming languages
Amiga support and maintenance software for other information regarding software that runs on Amiga.
Notes
References
Amiga
Productivity
Lists of software
Multimedia
New media
Animation software
Multimedia software | Amiga productivity software | [
"Technology"
] | 4,609 | [
"New media",
"Lists of software",
"Computing-related lists",
"Multimedia software",
"Multimedia"
] |
14,435,972 | https://en.wikipedia.org/wiki/Stereotactic%20biopsy | Stereotactic biopsy, also known as stereotactic core biopsy, is a biopsy procedure that uses a computer and imaging performed in at least two planes to localize a target lesion (such as a tumor or microcalcifications in the breast) in three-dimensional space and guide the removal of tissue for examination by a pathologist under a microscope. Stereotactic core biopsy makes use of the underlying principle of parallax to determine the depth or "Z-dimension" of the target lesion.
Stereotactic core biopsy is extensively used by radiologists specializing in breast imaging to obtain tissue samples containing microcalcifications, which can be an early sign of breast cancer.
Uses
X-ray-guided stereotactic biopsy is used for impalpable lesions (cannot be felt manually) that are also not visible on ultrasound.
A stereotactic biopsy may be used, with x-ray guidance, for performing a fine needle aspiration for cytology and needle core biopsy to evaluate a breast lesion. However, that type of biopsy is also sometimes performed without any imaging guidance, and typically, stereotactic guidance is used for core biopsies or vacuum-assisted mammotomy.
Stereotactic core biopsy is necessary for evaluating atypical appearing calcifications found on mammogram of the breast. If the calcifications exhibit the classic "teacup" appearance of benign fibrocystic changes, then a biopsy is usually not necessary.
References
Further reading
Meyer JE, Smith DN, Lester SC, et al. Large-core needle biopsy of nonpalpable breast lesions. JAMA 1999; 281:1638-1641
External links
Stereotactic biopsy entry in the public domain NCI Dictionary of Cancer Terms
Pathology | Stereotactic biopsy | [
"Biology"
] | 374 | [
"Pathology"
] |
14,436,015 | https://en.wikipedia.org/wiki/Amiga%20support%20and%20maintenance%20software | Amiga support and maintenance software performs service functions such as formatting media for a specific filesystem, diagnosing failures that occur on formatted media, data recovery after media failure, and installation of new software for the Amiga family of personal computers—as opposed to application software, which performs business, education, and recreation functions.
The Amiga came with some embedded utility programs, but many more were added over time, often by third-party developers and companies.
Original utilities
Commodore included utility programs with the operating system. Many of these were original features, which were adopted into other systems:
Installer is a tool for the installation of Amiga software. It features a LISP-like language to handle installations. The Amiga Installer does not support dependencies or track where the installed files are delivered; it simply copies them.
AmigaGuide is a hypertext markup scheme and a browser for writing and reading web page-like documents. AmigaGuide files are text files in a simple markup language, which facilitates editing and localization in any ASCII text editor. Commodore developed the AmigaGuide format before the World Wide Web was widely known. Consumers who bought Amiga computers in a store did not receive documentation on how to write AmigaGuide documents.
Utilities borrowed from other systems
Update tools:
Updater is a utility to keep system and third party files up to date
AmiUpdate was developed by Simon Archer to keep installed third-party programs up to date.
Grunch is a software center for AmigaOS and MorphOS.
MorphUP allows MorphOS users to install and update new third-party software.
None of these update systems was widely used by the Amiga community.
Commodities and utilities
Amiga places system utilities in two standard directories:
The Utilities directory contains programs like IconEdit.
The Commodities directory (volume SYS:Tools/Commodities/ or SYS:Utilities/Commodities under AmigaOS4) contains executable applet-like utilities which enhance system usability, like for example the ScreenBlanker, the default screen saver shipped with AmigaOS. Commodities are usually loaded at system startup. Many require no interaction and do not feature any GUI interface.
A system utility called Exchange allows the user to disable, enable, hide, show, and quit Commodities.
Hard disk partitioning
AmigaOS features a standard centralized utility to partition and format hard disks, called HDToolBox.
MorphOS uses an updated version of the SCSIConfig utility (since MorphOS version 2, HDConfig) implemented by third party vendor Phase5. In spite of the name, "SCSIConfig" possessed a unique feature at the time, which was providing a consistent mechanism to manage all types of disk interfaces, including IDE, irrespective of which interface the disk(s) in question used.
Diagnostic tools
AmigaOS diagnostic tools are usually programs which display the current state of Exec and AmigaDOS activities.
Active process explorer: Scout, Ranger
System calls and messages: SnoopDOS, Snoopium
Memory management: CyberGuard, Enforcer, MemMungWall, TLSFMem by Chris Hodges
Virtual memory: GigaMem, VMM
Benchmark utilities AmiBench, AIBB
Degrading tools: Degrader (which "degrades" modern Amiga systems to performance and hardware equivalents of legacy Amiga models)
Promoting tools
Promoter and ForceMonitor are utilities that allow the user to control the resolution of Intuition screens for Amiga programs.
Game loaders
WHDLoad is a utility to install legacy Amiga games on a hard disk and load them from Workbench desktop instead of floppies, on which they were often delivered.
jst is an older utility which the developer abandoned in order to concentrate efforts on WHDLoad. Old jstloaders can be read with WHDLoad, and jst itself has some early level of WHDLoad compatibility.
Command line interfaces and text-based shells
The original Amiga CLI (Command Line Interface) had some basic editing capabilities, command templates, and other features such as ANSI compatibility and color selection. In AmigaOS 1.3, the program evolved into a complete text-based shell called AmigaShell, with command history and enhanced editing capabilities.
Third-party developers created improved shells because the console-handler standard command line device driver (or "handler" in Amiga technical language) is independent of the command-line interpreter. This program controlled text-based interfaces into Amiga. Console-handler replacements include KingCON, ViNCEd, and Conman.
Some well-known shells from other platforms were ported to Amiga. These included bash (Bourne Again SHell), CSH (C Shell), and ZSH (Z shell). The shells taken from Unix and Linux were adapted into Amiga and improved with its peculiar capabilities and functions.
The MorphOS Shell is an example of Z shell mixed with the KingCON console handler. It originated as a Unix-like shell and is provided with all the features expected from such a component: AmigaDOS commands (more than 100 commands, most of which are Unix-like), local and global variables, command substitution, command redirection, named and unnamed pipes, history, programmable menus, multiple shells in a window, ANSI compatibility, color selection, and so on. It also includes all the necessary commands for scripting.
Amiga WIMP GUI interfaces
Starting from the original Amiga WIMP standard desktop, Workbench, Amiga interfaces were enhanced by third-party developers. Amiga users are free to replace the original Workbench interface with Scalos and Directory Opus. The standard GUI toolkit, called Intuition, was enhanced in OS2.x with the introduction of GadTools; and third parties created their own toolkits such as Magic User Interface (MUI) (the standard on MorphOS systems) and ClassAct, which evolved into ReAction GUI (the standard GUI on AmigaOS 4.0).
Amiga Advanced Graphics Systems
Many users have added advanced graphics drivers to their Amiga. This lets the AmigaOS handle high resolution graphics, enhanced with millions of colors. Standard GUI interfaces with this capability are CyberGraphX, EGS, and Picasso96.
Graphical engines
Graphical libraries available on the Amiga include:
Warp3D, a 3D graphic engine for Amiga
TinyGL (MorphOS) and MiniGL (AmigaOS), implementations of subsets of the OpenGL graphics engine
X11, also available through the Amiga versions of Cygnix
Cairo Vector Library, available on AmigaOS 4 and MorphOS
SSA (Super Smooth Animation), a proprietary system for playback at 50 Hz or 60 Hz. proDAD Adorage was the first product to use this.
GTK. On Amiga it is being developed as a GTK_MUI wrapper, to map any existing graphical features of GTK to the standard Magic User Interface (MUI) graphic user interface system.
All Amiga systems can also support the SDL (Simple DirectMedia Layer) cross-platform, multimedia, and free software libraries written in C which creates an abstraction over various platforms' graphics, sound, and input APIs, allowing a developer to write a computer game or other multimedia application once and run it on many operating systems.
PostScript
Amiga supports PostScript through Ghostscript and SaxonScript (included with Saxon Publisher). Ghostview is the foremost used graphical GUI for GhostScript on the Amiga.
Since AmigaOS 2.1, in the Prefs (Preferences) system directory, there is a printer preferences program called PrinterPS, which allows the use of PostScript printers on the Amiga.
TrueType fonts, color and anim fonts
Original Amiga outline fonts (also called vector fonts) were Agfa Compugraphic fonts available since AmigaOS 2.0 with the standard utility Fountain (later called IntelliFont) from Commodore. Third-party developers added support for TrueType fonts using various libraries, such as TrueType Library I and II, and LibFreeType library.
The standard diskfont.library also supported bitmap multicolour fonts (ColorFonts), such as the commercial Kara Fonts, or even animated fonts also originally created by Kara Computer Graphics.
Font designer software
Commodore provided a bitmap font editor called FED. Personal Fonts Maker was the most widely used Amiga software to create bitmap fonts, while TypeSmith v.2.5b was the de facto standard utility to create outline fonts.
File management
Backup and recovery
In the first Amiga OS releases, Commodore included a standard floppy disk recovery utility called DiskDoctor. Its purpose was to recover files from mangled floppy disks. Unfortunately, this utility worked only with AmigaDOS standard disks. A major fault was that it did not save the recovered data on different disks, rather it saved the info on the original and performed its operations directly on the original. It wrote on original disks and destroyed non-AmigaDOS disks (mainly autobooting games) by overwriting their bootblock. DiskDoctor renamed recovered disks to "Lazarus" (after the resurrected man in the New Testament).
These features were undocumented and led to an Amiga urban legend that there was a computer virus nicknamed the Lazarus Virus, whose final purpose was to make disks unreadable and renaming it with that name. Third-party developers released data recovery programs such as DiskSalv, which was more often used to validate Amiga filesystems on hard disk partitions.
Other Amiga disk repair and backup tools included:
Floppy only: Disk Mechanic, Disk Repair, Dr. Ami
Floppy and hard drive: Ami-Back Tools, Ami-Filesafe Pro, Quarterback Tools, Amiga Tools DeLuxe, Diavolo Backup
Smart File System (SFS): SFS Recover Tool, SFSDoctor, SFSCheck 2, SFSResize 1.0
Disk copiers
During the 8 bit and 16/32 bit era, copying software was not considered illegal in many countries, and piracy was not perceived as being a crime by the users of home computers (usually young people). Commodore 64 and ZX Spectrum software was copied using cassette decks, while IBM PC, Atari 8-bit, and Amiga software was copied using special programs called disk copiers which were engineered to copy any floppy disk surface byte by byte, often using special, efficient, and advanced techniques of programming and "Disk Track driving" to maintain Floppy Disk read/write head alignment.
In the early days of the Amiga platform, about 16 disk copiers were created in a short amount of time (1985–1989) that enabled copying Amiga floppy disks, including Nibbler, QuickNibble, ZCopier, XCopy/Cachet, FastCopier, Disk Avenger, Tetra Copy (which enabled the user to play Tetris while copying disks), Cyclone, Maverick, D-Copy, Safe II, PowerCopier, Quick Copier, Marauder II (styled as "Marauder //"), Rattle Copy, and BurstNibble.
Many were legal in many countries until years later. These programs (for example, Marauder, X-Copy, and Nibbler) were then sold in packages complete with instructions, warranty, and EULA like other productivity software. Some floppy drives included LED track indicators to show if the disks were hacked by the original programmers to support up to track 82 of the disk. There were also copying solutions that included both hardware and software, like Super Card Ami II and Syncro Express I/II/III.
DFC5 could only copy standard AmigaOS formatted disks for backup purposes; however, it multitasked inside of the Amiga Workbench GUI.
X-COPY III, and later the final version, X-COPY Pro, were the most popular Amiga copy programs. They were capable of bit-by-bit copying, also called "nibbling". Although incapable of true multitasking, the programs were capable of taking advantage of Amiga configurations with multiple floppy drives; for instance, on Amiga systems with four floppy drives, X-COPY was capable of simultaneously copying from a source drive to three others. Coupled with excellent bit-by-bit replication capabilities, these features made X-COPY the de facto standard for copying floppy disks on the Amiga.
Another popular copying program was D-COPY, by a Swedish group "D-Mob", which, in spite of some innovative features and better/faster copying routines, failed to gain dominance.
Archives and compression utilities
The most popular archivers were LhA and LZX. Programs to archive ZIP, Gzip, Bzip2, and RAR files were available but seldom used, and many have an Amiga counterpart, such as 7-Zip. Utilities were available for reading and writing archive formats such as ARC, ARJ (unarchive only), the CAB files common in Windows installation, StuffIt SIT archives from Macintosh, Uuencode (used for encoding binary attachments of e-mail messages), TAR (common on UNIX and Linux), RPM (from Red Hat), and more.
Amiga supported "packed" or "crunched" (meaning compressed) executables, which were common in the age of floppy disks, when disk space and memory conservation was critical. These executable binary files had a decompress routine attached to them that would automatically unpack or decrunch (decompress) the executable upon loading into memory.
The Amiga also included "level depacking", implemented by "Titanics Cruncher", which enabled a binary executable to be decrunched as it was being loaded, requiring a very small amount of memory to do so. In general, packing and crunching was taken from the Commodore 64 cracking scene. Some crunchers, such as Time Cruncher, were "ported" from Commodore 64, displaying the same visual effects during decrunching. The CPU in the Amiga was completely different from the one in the Commodore 64, requiring a complete rewrite.
Noteworthy were TurboImploder and PowerPacker, as they were easy to use, with graphical interfaces. Other popular crunchers were DefjamPacker, TetraPack, DoubleAction, Relokit, StoneCracker, Titanics and CrunchMania. The ability to compress and decompress single files and directories on the fly has been present on the AmigaOS since at least 1994.
A similar feature was implemented relatively recently as a property in the ZFS filesystem.
The AmigaOS packers and cruncher libraries are centralized by using the XPK system. The XPK system consists of a master library and several (de)packer sublibraries. Programs use only the master library directly, while sublibraries (akin to plug-ins) implement the actual (de)compression. When unpacking/decrunching, the applications do not need to know which library was used to pack or crunch the data. XPK is a wrapper for crunchers; to decrunch non-XPK packed formats requires XFD.
Another important invention on the Amiga platform was the ADF format for creating images of Amiga floppy disks, either standard AmigaDOS floppies or non-DOS ("NDOS") ones, for use in Amiga emulators, such as WinUAE. Amiga emulators and AmigaOS (with third-party software) can use these files as if they were virtual floppy disks. Unlimited virtual floppies could be created on modern Amigas, although WinUAE on a real PC can handle only four at a time, the maximum number of floppy drives that the Amiga hardware could have connected at any one time.
All the popular Amiga compression implementations and archive files are now centralized and implemented by a single system library called XAD, which has a front-end GUI named Voodoo-X. It is included in AmigaOS 3.9 and up with UnArc. This library is modular and can handle more than 80 compression formats.
Filesystems
Amiga can use various filesystems. The historical standards are the original Amiga filesystem, called the Old File System. This was good for floppy disks but wasted space on hard disks and is considered obsolete.
The Fast File System (FFS) can handle file names up to 30 characters, has international settings (it can optionally recognise upper- and lower-case accented letters as equivalent) and could also be cached, if the users chose to format the partition with the cache option. The FFS filesystem evolved into FFS2.
Modern journaling file systems for Amiga are the Smart File System (SFS) and Professional File System (PFS).
The MultiUser File System (MuFS) supports multiple users. Using MuFS the owner of the system could grant various privileges on files by creating privileges for groups and users. It was first available with the Ariadne Ethernet card, and later standalone. The Professional File System suite has a utility to let PFS to be patched to support MuFS and MuFS features. The latest version is 1.8 and was released in 2001.
CrossDOS is a utility to read MS-DOS formatted floppy disks in FAT12 and FAT16 filesystem, either 720 KiB double-density format or high-density (1440 KiB) (on connected floppy drives that can read 1440 MS-DOS disks). It is a commercial product, and a slightly cut-down version was included with AmigaOS beginning with version 2.1.
The FAT95 library recognizes partitions of various filesystems common in other systems such as FAT16 and FAT32. It also reads DOS floppies and USB pen drives formatted with FAT16 or FAT32.
Filesystems like ext2 for Linux, NTFS from Microsoft, and more are supported by third-party developers.
MorphOS natively supports SFS, FFS/FFS2, PFS, MacOS HFS, HFS+, Linux Ext2, FAT16, FAT32, and NTFS filesystems.
Data/file types
The Datatype system of AmigaOS is a centralized, expandable, modular system describing any kind of file (text, music, image, videos). Each has a standard load/save module.
Any experienced programmer, using the Amiga Datatype programming guidelines, could create new standard datatype modules. The module could be left visible to the whole Amiga system (thus to all Amiga programs) by copying the datatype into the system directory SYS:Classes/DataTypes/, and the descriptor (used to identify files) into DEVS:DataTypes/.
This allows programs to load and save any files for which the corresponding datatypes exist. File descriptors did not need to be embedded in the executable code. An independent system of loaders was not needed for new productivity software. Amiga productivity software tools therefore have a smaller size and a more clean design than similar programs running in other operating systems.
Supported Amiga datatypes include:
MultiView
MultiView is the Amiga universal viewer. It can load and display any file for which a corresponding datatype exists.
MIME types
Modern Amiga-like operating systems such as AmigaOS 4.0 and MorphOS can handle also MIME types. Any kind of file, due to its peculiar characteristics (thanks to filename extensions), or data embedded into the file itself (for example into file header) can be associated with a program that handle it, and this feature improves and completes the capabilities of Amiga to recognize and deal with any kind of file.
Device support
USB
The only known historical USB stack for the Amiga was created for the MacroSystem DraCo Amiga clone. It supported only USB 1.0 and ceased with the demise of that platform.
Modern USB support drivers for Amiga are:
Poseidon USB stack available for AmigaOS 3, AROS, and MorphOS by Chris Hodges (open-source software). Poseidon has a modular approach to USB, and various hardware devices are supported by a certain number of HID devices.
Sirion USB stack of AmigaOS 4.0
ANAIIS (Another Native Amiga IO Interface Stack) by Gilles Pelletier
FireWire (IEEE 1394)
The only known historical Amiga support for FireWire was built for the DraCo Amiga clone by Macrosystem.
Only one FireWire interface exists for Amiga. It is named Fireworks, and it was created for the MorphOS system by programmer Pavel Fedin. It is still in an early stage of development and is freely downloadable.
Printer drivers
The print manager program TurboPrint, by German firm IrseeSoft, is the de facto standard for advanced printing on the Amiga. It is a modular program with many drivers which support many modern printers. PrintStudio Professional I and II are another well known printer driver system for the Amiga.
PrintManager v39 by Stephan Rupprecht, available at the Aminet repository, is a print spooler for AmigaOS 3.x and 4.0.
Video digitizers
Video digitizing includes DigiView; the FrameMachine Zorro II expansion card for A2000, 3000, 4000; the Impact Vision IV24 from GVP; the VidiAmiga real time digitizer; and the Paloma module for the Picasso IV graphics card.
Graphic Tablets
In the 1980s, SummaGraphics tablets were common. Summagraphics directly supported Amiga with its drivers.
In 1994, GTDriver (Graphic Tablet Driver) was the most common driver for serial port tablets, like Summagraphics MM, Summagraphics Bitpadone, CalComp 2000, Cherry, TekTronix 4967, and WACOM. It could also be used as a mouse driver.
Graphics tablets now are mainly USB devices and are automatically recognized by Amiga USB stacks. The most widely used driver for graphic tablets is FormAldiHyd. FormAldiHyd can be used with Aiptek, Aldi, Tevion, and WACOM IV (Graphire, ArtPad, A3, A4, A5, and PenPartner) graphic tablets.
The Poseidon USB driver, written by the same author as FormAldiHyd, Chris Hodges, directly supports USB graphics tablets, including ones more modern than FormAldiHyd.
Scanner drivers
Amiga programs often have scanner drivers embedded in their interface and are limited to some ancient scanner models. One example is Art Department Professional (ADPro).
In recent times, scanner management is managed by the Amiga Poseidon USB stack. Poseidon detects scanners from their signature, and loads the corresponding HIDD scanner module. The graphical interface is managed by programs like ScanTrax and ScanQuix.
Genlocks, chromakey, signal video inverters
The Amiga has special circuitry to support a genlock signal and chromakey. Genlock software vendors included GVP (Great Valley Products) (an American hardware manufacturer) and Hama, Electronic Design, and Sirius genlocks from Germany.
Infrared/remote controls
The IRCom class is a driver that supports the IRCom standard and is available for the USB Poseidon Stack.
Pegasos computers have an internal IrDA port connector for connecting infrared devices, but MorphOS offers no support for it. The internal IrDA port can be used by installing Linux.
WiFi and Bluetooth
The Amiga can use WiFi external routers connected physically through Ethernet cable and talk with remote WiFi devices. Drivers are available for Prism2 internal PCI and PCMCIA WiFi expansion cards, but there are no drivers for Bluetooth standard devices like mobile phones, Bluetooth handsets, keyboards, or mice.
A USB class exists for the Poseidon stack to use the "Wireless PC Lock" USB device by Sitecom Europe BV and engage its security functions. It is called Wireless PC Lock.
Others
In the past, drivers and hardware cards were available to drive the Polaroid Freeze Frame Digital Camera System Polaroid Digital Palette CI-3000 and Digital Palette CI 5000, with Polaroid software.
Drivers for single-frame video recorders allow users to save on tape the 3D animations created on the Amiga using Ampex and Betacam devices. Also available are time-base correctors (TBCs), a family of devices correcting timing errors; one was the Personal TBC series.
The Amiga helped to create and launch digital recorders coupled with an internal hard disk and a DVD drive for file transfer. One was Broadcaster Elite, one of the first digital video recorders, based on a SCSI system and a Zorro II Amiga expansion card.
Expansion cards could transform an Amiga into a waveform monitor or vectorscope.
The Phonepak card from GVP transformed the Amiga into a telephone switchboard, fax system, and SOHO (small office/home office) answering machine.
The Amiga was used as a video titler system in the experimental era of high-definition television. A battery of three Amigas was used as a video titler on analog HDTV experiments on HDTV NTSC 1125 lines standard, by channels like ESPN, ABC, and NBC.
See also
Amiga productivity software
Amiga music software
Amiga programming languages
Amiga Internet and communications software
References
Amiga
Support and maintenance
Lists of software | Amiga support and maintenance software | [
"Technology"
] | 5,184 | [
"Computing-related lists",
"Lists of software"
] |
14,436,317 | https://en.wikipedia.org/wiki/Doubled%20haploidy | A doubled haploid (DH) is a genotype formed when haploid cells undergo chromosome doubling. Artificial production of doubled haploids is important in plant breeding.
Haploid cells are produced from pollen or egg cells or from other cells of the gametophyte, then by induced or spontaneous chromosome doubling, a doubled haploid cell is produced, which can be grown into a doubled haploid plant. If the original plant was diploid, the haploid cells are monoploid, and the term doubled monoploid may be used for the doubled haploids. Haploid organisms derived from tetraploids or hexaploids are sometimes called dihaploids (and the doubled dihaploids are, respectively, tetraploid or hexaploid).
Conventional inbreeding procedures take six generations to achieve approximately complete homozygosity, whereas doubled haploidy achieves it in one generation. Dihaploid plants derived from tetraploid crop plants may be important for breeding programs that involve diploid wild relatives of the crops.
History
The first report of the haploid plant was published by Blakeslee et al. (1922) in Datura stramonium. Subsequently, haploids were reported in many other species. Guha and Maheshwari (1964) developed an anther culture technique for the production of haploids in the laboratory. Haploid production by wide crossing was reported in barley (Kasha and Kao, 1970) and tobacco (Burk et al., 1979). Tobacco, rapeseed, and barley are the most responsive species for doubled haploid production. Doubled haploid methodologies have now been applied to over 250 species.
Production of doubled haploids
Doubled haploids can be produced in vivo or in vitro. Haploid embryos are produced in vivo by parthenogenesis, pseudogamy, or chromosome elimination after wide crossing. The haploid embryo is rescued, cultured, and chromosome-doubling produces doubled haploids. The in vitro methods include gynogenesis (ovary and flower culture) and androgenesis (anther and microspore culture). Androgenesis is the preferred method. Another method of producing the haploids is wide crossing. In barley, haploids can be produced by wide crossing with the related species Hordeum bulbosum; fertilization is affected, but during the early stages of seed development the H. bulbosum chromosomes are eliminated leaving a haploid embryo. In tobacco (Nicotiana tabacum), wide crossing with Nicotiana africana is widely used. When N. africana is used to pollinate N. tabacum, 0.25 to 1.42 percent of the progeny survive and can readily be identified as either F1 hybrids or maternal haploids. Although these percentages appear small, the vast yield of tiny seeds and the early death of most seedlings provide significant numbers of viable hybrids and haploids in relatively small soil containers. This method of interspecific pollination serves as a practical way of producing seed-derived haploids of N. tabacum, either as an alternative method or complementary method to anther culture.
Genetics of DH population
In DH method only two types of genotypes occur for a pair of alleles, A and a, with the frequency of ½ AA and ½ aa, while in diploid method three genotypes occur with the frequency of ¼ AA, ½ Aa, ¼ aa. Thus, if AA is desirable genotype, the probability of obtaining this genotype is higher in haploid method than in diploid method. If n loci are segregating, the probability of getting the desirable genotype is (1/2)n by the haploid method and (1/4)n by the diploid method. Hence the efficiency of the haploid method is high when the number of genes concerned is large.
Studies were conducted comparing DH method and other conventional breeding methods and it was concluded that adoption of doubled haploidy does not lead to any bias of genotypes in populations, and random DHs were even found to be compatible to selected line produced by conventional pedigree method.
Applications of DHs plant breeding
Mapping quantitative trait loci
Most of the economic traits are controlled by genes with small but cumulative effects. Although the potential of DH populations in quantitative genetics has been understood for some time, it was the advent of molecular marker maps that provided the impetus for their use in identifying loci controlling quantitative traits. As the quantitative trait loci (QTL) effects are small and highly influenced by environmental factors, accurate phenotyping with replicated trials is needed. This is possible with doubled haploidy organisms because of their true breeding nature and because they can conveniently be produced in large numbers. Using DH populations, 130 quantitative traits have been mapped in nine crop species. In total, 56 DH populations were used for QTL detection.
Backcross breeding
In backcross conversion, genes are introgressed from a donor cultivar or related species into a recipient elite line through repeated backcrossing. A problem in this procedure is being able to identify the lines carrying the trait of interest at each generation. The problem is particularly acute if the trait of interest is recessive, as it will be present only in a heterozygous condition after each backcross. The development of molecular markers provides an easier method of selection based on the genotype (marker) rather than the phenotype. Combined with doubled haploidy it becomes more effective. In marker assisted backcross conversion, a recipient parent is crossed with a donor line and the hybrid (F1) backcrossed to the recipient. The resulting generation (BC1) is backcrossed and the process repeated until the desired genotypes are produced. The combination of doubled haploidy and molecular marker provides the short cut. In the backcross generation one itself, a genotype with the character of interest can be selected and converted into homozygous doubled-haploid genotype. Chen et al. (1994) used marker assisted backcross conversion with doubled haploidy of BC1 individuals to select stripe rust resistant lines in barley.
Bulked segregant analysis (BSA)
In bulked segregant analysis, a population is screened for a trait of interest and the genotypes at the two extreme ends form two bulks. Then the two bulks are tested for the presence or absence of molecular markers. Since the bulks are supposed to contrast in the alleles that contribute positive and negative effects, any marker polymorphism between the two bulks indicates the linkage between the marker and trait of interest. BSA is dependent on accurate phenotyping and the DH population has particular advantage in that they are true breeding and can be tested repeatedly. DH populations are commonly used in bulked segregant analysis, which is a popular method in marker assisted breeding. This method has been applied mostly to rapeseed and barley.
Genetic maps
Genetic maps are very important to understand the structure and organization of genomes from which evolution patterns and syntenic relationships between species can be deduced. Genetic maps also provide a framework for the mapping of genes of interest and estimating the magnitude of their effects and aid our understanding of genotype/phenotype associations. DH populations have become standard resources in genetic mapping for species in which DHs are readily available. Doubled haploid populations are ideal for genetic mapping. It is possible to produce a genetic map within two years of the initial cross regardless of the species. Map construction is relatively easy using a DH population derived from a hybrid of two homozygous parents as the expected segregation ratio is simple, i.e. 1:1. DH populations have now been used to produce genetic maps of barley, rapeseed, rice, wheat, and pepper. DH populations played a major role in facilitating the generation of the molecular marker maps in eight crop species.
Genetic studies
Genetic ratios and mutation rates can be read directly from haploid populations. A small doubled haploid (DH) population was used to demonstrate that a dwarfing gene in barley is located chromosome 5H. In another study the segregation of a range of markers has been analyzed in barley.
Genomics
Although QTL analysis has generated a vast amount of information on gene locations and the magnitude of effects on many traits, the identification of the genes involved has remained elusive. This is due to poor resolution of QTL analysis. The solution for this problem would be production of recombinant chromosome substitution line, or stepped aligned recombinant inbred lines. Here, backcrossing is carried out until a desired level of recombination has occurred and genetic markers are used to detect desired recombinant chromosome substitution lines in the target region, which can be fixed by doubled haploidy. In rice, molecular markers have been found to be linked with major genes and QTLs for resistance to rice blast, bacterial blight, and sheath blight in a map produced from DH population.
Elite crossing
Traditional breeding methods are slow and take 10–15 years for cultivar development. Another disadvantage is inefficiency of selection in early generations because of heterozygosity.
These two disadvantages can be over come by DHs, and more elite crosses can be evaluated and selected within less time.
Cultivar development
Uniformity is a general requirement of cultivated line in most species, which can be easily obtained through DH production. There are various ways in which DHs can be used in cultivar production. The DH lines themselves can be released as cultivars, they may be used as parents in hybrid cultivar production or more indirectly in the creation of breeders lines and in germplasm conservation. Barley has over 100 direct DH cultivars. According to published information there are currently around 300 DH derived cultivars in 12 species worldwide.
The relevance of DHs to plant breeding has increased markedly in recent years owing to the development of protocols for 25 species. Doubled haploidy already plays an important role in hybrid cultivar production of vegetables, and the potential for ornamental production is being vigorously examined. DHs are also being developed in the medicinal herb Valeriana officinalis to select lines with high pharmacological activity. Another interesting development is that fertile homozygous DH lines can be produced in species that have self-incompatibility systems.
Advantages of DHs
The ability to produce homozygous lines after a single round recombination saves a lot of time for the plant breeders. Studies conclude that random DH’s are comparable to the selected lines in pedigree inbreeding. The other advantages include development of large number of homozygous lines, efficient genetic analysis and development of markers for useful traits in much less time. More specific benefits include the possibility of seed propagation as an alternative to vegetative multiplication in ornamentals, and in species such as trees in which long life cycles and inbreeding depression preclude traditional breeding methods, doubled haploidy provides new alternatives.
Disadvantages of DHs
The main disadvantage with the DH population is that selection cannot be imposed on the population. But in conventional breeding selection can be practised for several generations: thereby desirable characters can be improved in the population.
In haploids produced from anther culture, it is observed that some plants are aneuploids and some are mixed haploid-diploid types. Another disadvantage associated with the double haploidy is the cost involved in establishing tissue culture and growth facilities. The over-usage of doubled haploidy may reduce genetic variation in breeding germplasm. Hence one has to take several factors into consideration before deploying doubled haploidy in breeding programmes.
Conclusions
Technological advances have now provided DH protocols for most plant genera. The number of species amenable to doubled haploidy has reached a staggering 250 in just a few decades. Response efficiency has also improved with gradual removal of species from recalcitrant category. Hence it will provide greater efficiency of plant breeding.
Tutorials
Doubled Haploids to Improve Winter Wheat
Video : Doubled Haploids: A simple method to improve efficiency of maize breeding.
References
Ardiel, G.S., Grewal, T.S., Deberdt, P., Rossnagel, B.G., and Scoles, G.J. 2002. Inheritance of resistance to covered smut in barley and development of tightly linked SCAR marker. Theoretical and applied genetics 104:457-464.
Blakelsee, A.F., Belling, J., Farhnam, M.E., and Bergner, A.D.1922. A haploid mutant in the Jimson weed, Datura stramonium. Science 55:646-647.
Burk, L.G., Gerstel, D.U., and Wernsman, E.A. 1979. Maternal haploids of Nicotiana tabacum L. from seed. Science 206:585.
Chen, F.Q., D.Prehn, P.M. Hayes, D.Mulrooney, A. Corey, and H.Vivar. 1994. Mapping genes for resistance to barley stripe rust (Puccinia striiformis f. sp. hordei). Theoretical and Applied Genetics. 88:215-219.
Friedt, W., Breun, J., Zuchner, S., and Foroughi-Wehr, B. 1986. Comparative value of androgenetic doubled haploid and conventionally selected spring barley line. Plant Breeding 97:56-63.
Guha, S., and Maheswari, S. C. 1964. In vitro production of embryos from anthers of Datura. Nature 204:497.
Immonen, S., and H. Anttila. 1996. Success in rye anther culture. Vortr. Pflanzenzuchtg. 35:237-244.
Kasha, K. J., and Kao, K. N. 1970. High frequency haploid production in barley (Hordeum vulgare L.). Nature 225: 874-876.
Kearsey, M. J. 2002. QTL analysis: Problems and (possible) solutions. p. 45-58. In: M.S. Kang (ed.), Quantitative genetics, genomics and plant breeding. CABI Publ., CAB International.
Maluszynski, M.., Kasha K. J., Forster, B.P., and Szarejko, I. 2003. Doubled haploid production in crop plants: A manual. Kluwer Academic Publ., Dordrecht, Boston, London.
Paterson, A.H., Deverna, J.W., Lanin, B., and Tanksley, S. 1990. Fine mapping of quantitative trait loci using selected overlapping recombinant chromosomes in an interspecies cross of tomato. Genetics 124:735-741.
Schon, C., M. Sanchez,T. Blake, and P.M. Hayes. 1990. Segregation of Mendelian markers in doubled haploid and F2 progeny of barley cross. Hereditas 113:69-72.
Thomas, W. T. B., B. Gertson and B.P. Forster. 2003. Doubled haploids in breeding p. 337-350. in :M. Maluszynski, K.J. Kasha, B.P. Forster and I. Szarejko (eds)., Doubled haploid production in crop plants:A Manual. Kluwer Academic Publ., Dordrecht, Boston, London.
Thomas, W.T.B., Newton, A.C., Wilson, A., Booth, A., Macaulay, M., and Keith, R. 2000. Development of recombinant chromosome substitution lines: A barley resource. SCRI Annual Report 1999/2000, 99-100.
Thomas, W.T.B., Powell, W., and Wood, W. 1984. The chromosomal location of the dwarfing gene present in the spring barley variety Golden Promise. Heredity 53:177-183.
Wang, Z., G. Taramino, D.Yang, G. Liu, S.V. Tingey, G.H. Miao, and G.L. Wang. 2001. Rice ESTs with disease-resistance gene or defense-response gene-like sequences mapped to regions containing major resistance genes or QTLs. Molecular Genetics and Genomics. 265:303-310.
William, K.J., Taylor, S.P., Bogacki, P., Pallotta, M., Bariana, H.S., and Wallwork, H. 2002. Mapping of the root lesion nematode (Pratylenchus neglectus) resistance gene Rlnn 1 in wheat. Theoretical and applied genetics 104:874-879.
Winzeler, H., Schmid, J., and Fried, P.M. 1987. Field performance of androgenetic doubled haploid spring wheat line in comparison with line selected by the pedigree system. Plant breeding 99:41-48.
Yi, H.Y., Rufty, R.C., Wernsman, E.A., and Conkling, M.C. 1998. Mapping the root-knot nematode resistance gene (Rk) in tobacco with RAPD markers. Plant Disease 82:1319-1322.
Plant breeding
Genetics
Plant genetics | Doubled haploidy | [
"Chemistry",
"Biology"
] | 3,702 | [
"Genetics",
"Plant genetics",
"Plants",
"Molecular biology",
"Plant breeding"
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14,436,459 | https://en.wikipedia.org/wiki/Japanese%20citrus | Japanese citrus fruits were first mentioned in the Kojiki and Nihonshoki, compiled in the 700s, and the Man'yōshū and Kokin Wakashū, poetry anthologies compiled in the 700s and 900s, mention the Tachibana orange as a subject of waka poetry and describe its use as a medicinal, ornamental, and incense plant.
Throughout their history, the Japanese have created and cultivated various varieties of citrus fruits, taking advantage of the mild climate that is ideal for growing citrus. In particular, from the 1600s during the Edo period (1603-1868) to the present, various varieties of citrus fruits have been produced, including Unshū, Natsumikan, Hassaku, Iyokan, and Dekopon. At present, Unshū is the most widely grown in Japan, and various cultivars have been developed.
At present, the largest citrus growing areas are located in the prefectures of Wakayama, Shizuoka, Tokushima, Kochi, Oita, Miyazaki and Ehime.
History
Citrus fruits are believed to have originated in Assam, India and the foothills of the Himalayas, and later spread throughout the world. In October 2023, published genetic research proved that the ancestor of the citrus plants originated in India more than 25 million years ago and evolved into the true citrus species in southern China 8 million years ago, followed by early citrus species such as pomelo and citron that originated in the foothills of the Himalayas. Yuzu, kunembo, and daidai, are believed to have been introduced to Japan from China between the Nara (710-794) and Muromachi periods (1336-1573).
The Kojiki and Nihon Shoki, compiled in the 700s, were the first books in Japan to describe citrus fruits. The Nihon Shoki states that a man named Tajimamori brought back citrus fruits from the Tokoyo no kuni (Land of immortality, :ja:常世の国) on the orders of Emperor Suinin, which is thought to refer to the tachibana orange that grows wild in Japan. The Man'yōshū, a collection of poems from the same period, contains many poems about tachibana orange, and because of its strong acidity at the time, it was dried and used for medicinal and ornamental purposes rather than for food. The Kokin Wakashū, compiled in the 900s, mentions that tachibana orange was burned and used as incense to give a nice fragrance to kimonos. In Japan, tachibana orange is a symbol of eternity and is the motif for the Order of Culture.
The most widely grown variety in Japan today is the unshu mikan (Citrus unshiu), also known as the satsuma orange. There are two theories about the origin of the unshu mikan. One is that unshu mikan originated in Japan, while the other is that it originated in China. According to the Japanese origin theory, several species that would serve as the parents of unshu mikan were introduced from China, and in the 1600s, they were born in Nishi-Nakajima, Higo Province (later Nagashima, Kagoshima) in Japan. The Japanese Ministry of Agriculture, Forestry and Fisheries, Ehime Prefecture and Japanese scientists support this theory of Japanese origin. Genetic research has shown that the unshu mikan is a cross between the kishu and kunembo. During the Edo period, unshu mikan were not very popular due to a superstition that eating seedless unshu mikan would make one infertile. It was not until the Meiji era (1868–1912), when modernization began, that the popularity of unshu mikan increased. From the mid-Edo period (1603–1867) to the mid-Meiji era (1868-1912), kishu mikan were the mainstay of cultivation.
From the Edo period (1603–1867) to the present, the Japanese have created numerous varieties of citrus fruits, collectively known as . It is a general term for citrus fruits shipped from January to May, after the shipping period of unshu mikan, which is from October to February. For example, natsumikan (Citrus natsudaidai) was developed around 1700,
hassaku in 1860,
and iyokan in 1886. Kiyomi, Setoka and Kanpei are also types of . dekopon, created in 1972, is one of the most popular varieties internationally. Dekopon was introduced to South Korea in the 1990s and became popular as Hallabong, was exported to California in 1998, and has been marketed as "Sumo Citrus" since 2011.
Japan's warm summer climate makes it particularly suitable for citrus plants; while they are grown all over the country, the largest citrus growing areas are located in the prefectures of Wakayama, Shizuoka, Tokushima, Kochi, Oita, Miyazaki and Ehime. In Japan, various cultivars have been developed based on the unshu mikan, and three cultivars, namely miyagawa wase, okitsu wase, and aoshima unshu, account for nearly half of the production volume of unshu mikan.
Japanese taxonomy
Japan usually follows the botanical names of the taxonomy from Tyôzaburô Tanaka, often referred to as the "Tanaka system", giving for each cultivar a separate name no matter if it is pure or a hybrid of two or more species or varieties. While elsewhere it is more popular to classify the genus citrus into species, and further into varieties, and then into cultivars or hybrid. Such a system was created by Walter Tennyson Swingle from Florida and is called the "Swingle system". The different approaches of the two systems lead to partially-overlapping or nested 'species', for example, Citrus unshiu and Citrus tangerina (Tanaka) versus Citrus reticulata (Swingle). Likewise, common terms, like "mikan", do not always align with these taxonomic groups.
Japanese citrus (partial list)
Japanese citrus fruits include the following:
References
External links
Japanese citrus glossary
Citrus
Japanese fruit
Lists of plants
Citrus | Japanese citrus | [
"Biology"
] | 1,276 | [
"Lists of biota",
"Lists of plants",
"Plants"
] |
14,437,519 | https://en.wikipedia.org/wiki/Critical%20system | A critical system is a system which must be highly reliable and retain this reliability as it evolves without incurring prohibitive costs.
There are four types of critical systems: safety critical, mission critical, business critical and security critical.
Description
For such systems, trusted methods and techniques must be used for development. Consequently, critical systems are usually developed using well-tested techniques rather than newer techniques that have not been subject to extensive practical experience. Developers of critical systems are naturally conservative, preferring to use older techniques whose strengths and weaknesses are understood, rather than new techniques which may appear to be better, but whose long-term problems are unknown.
Expensive software engineering techniques that are not cost-effective for non-critical systems may sometimes be used for critical systems development. For example, formal mathematical methods of software development have been successfully used for safety and security critical systems. One reason why these formal methods are used is that it helps reduce the amount of testing required. For critical systems, the costs of verification and validation are usually very high—more than 50% of the total system development costs.
Classification
A critical system is distinguished by the consequences associated with system or function failure. Likewise, critical systems are further distinguished between fail-operational and fail safe systems, according to the tolerance they must exhibit to failures:
Fail-operational — typically required to operate not only in nominal conditions (expected), but also in degraded situations when some parts are not working properly. For example, airplanes are fail-operational because they must be able to fly even if some components fail.
Fail-safe — must safely shut down in case of single or multiple failures. Trains are fail-safe systems because stopping a train is typically sufficient to put into safe state.
Safety critical
Safety critical systems deal with scenarios that may lead to loss of life, serious personal injury, or damage to the natural environment. Examples of safety-critical systems are a control system for a chemical manufacturing plant, aircraft, the controller of an unmanned train metro system, a controller of a nuclear plant, etc.
Mission critical
Mission critical systems are made to avoid inability to complete the overall system, project objectives or one of the goals for which the system was designed. Examples of mission-critical systems are a navigational system for a spacecraft, software controlling a baggage handling system of an airport, etc.
Business critical
Business critical systems are programmed to avoid significant tangible or intangible economic costs; e.g., loss of business or damage to reputation. This is often due to the interruption of service caused by the system being unusable. Examples of business-critical systems are clients' accounting systems for a bank, a stock-trading systems, enterprise resource planning systems, search engines, etc. These are often delineated via a business impact analysis. The term is sometimes used interchangeably with 'mission critical'; however business critical systems can be defined as those not necessary during incidents, while mission critical systems are seen as essential for any operations at any time.
Security critical
Security critical systems deal with the loss of sensitive data through theft or accidental loss.
See also
Reliability theory
Reliable system design
Redundancy (engineering)
Factor of safety
Formal methods
Notes
Control engineering
Systems engineering
Engineering failures
Maintenance
Safety
Reliability analysis | Critical system | [
"Technology",
"Engineering"
] | 648 | [
"Systems engineering",
"Reliability analysis",
"Reliability engineering",
"Technological failures",
"Engineering failures",
"Control engineering",
"Civil engineering",
"Mechanical engineering",
"Maintenance"
] |
11,758,353 | https://en.wikipedia.org/wiki/Perceptual%20attack%20time | Perceptual Attack Time (often abbreviated "PAT") is a subjective measure of the time instant at which a musical sound's rhythmic emphasis is heard. It is analogous to the perceptual centre (aka "p-centre") in speech.
It is different from both the physical onset (i.e., the time at which the sound's acoustic energy first begins) and the perceptual onset (i.e., the subjective time at which a listener first notices that the sound has begun). For a very percussive sound such as a note played on a closed hi hat cymbal the perceptual attack time may be just a few milliseconds, while for a note bowed slowly on a violin the perceptual attack time may be as much as 50–100 milliseconds after the physical onset.
Applications
Understanding the perceptual attack time of recorded sounds is important when scheduling those sounds to be played by a computer. For example, suppose you want
to play a melody on a series of notes from different instruments. If the notes' physical onsets are equally spaced, the result will probably sound a little bit unsteady or out of rhythm; to get a rhythmically correct result it's necessary to account for each sound's perceptual attack time, i.e., to schedule the notes so that their perceptual attack times, not their onsets, are spaced according to the rhythm of the melody.
References
Collins, N. (2006). "Investigating computational models of perceptual attack time", Proceedings of the 9th International Conference on Music Perception & Cognition (ICMPC9).
Gordon, J. W. (1987). The perceptual attack time of musical tones. Journal of the Acoustical Society of America, 82(1), 88–105.
Vos, J., & Rasch, R. (1981). The perceptual onset of musical tones. Perception and Psychophysics, 29(4),323–35.
Wright, M. (2008) "The Shape of an Instant: Measuring and Modeling Perceptual Attack Time with Probability Density Functions (If a Tree Falls in the Forest, When Did 57 People Hear it Make a Sound?)" Ph.D. Dissertation, Stanford University.
Experimental psychology
Rhythm and meter | Perceptual attack time | [
"Physics"
] | 493 | [
"Spacetime",
"Rhythm and meter",
"Physical quantities",
"Time"
] |
11,758,515 | https://en.wikipedia.org/wiki/Kontron | Kontron AG is a German-based multinational company that designs and manufactures embedded systems, modules and boards, and provides software products for Internet of Things and 5G technologies.
The company operates in various industrial segments (including industrial automation, communications, transportation, energy, avionics, medical, automotive, and military), manufacturing and selling its products worldwide. Kontron is a premier member of the Intel Embedded Alliance.
The corporate group was originally headquartered in Augsburg and consisted of the Kontron Europe GmbH, with its main sites in Ismaning, Augsburg, Deggendorf, and Saarbrücken (other locations included San Diego, Fremont, California, Montreal, Plzeň, Toulon, Bangalore, Taipei, Tokyo and Beijing). Kontron acquired Dolch in 2005.
At the 2007 Embedded World trade exhibition in Nuremberg, Kontron introduced a product called UGM-M72, a modular graphics card for Computer-on-Module systems, which was based on Universal Graphics Module (UGM) design specification standard published by XGI Technology and Kontron in June 2007. The card used the M72 GPU from ATI Technologies, and was 84 x 95 mm in size. Version 1.1 of UGM standard was published in July 2008, and Advanced Micro Devices (the parent company of ATI) announced in August 2008 that it would support the new standard. A web site for UGM standard was maintained by XGI and Kontron until the Great Recession in 2009.
In August 2017, Kontron was merged into Austrian-based S&T, and was renamed Kontron Group on 1 June 2022, with its corporate headquarters in Linz.
In 2022, Kontron announced the sale of its IT services business to Vinci SA in order to concentrate on its realignment as a provider of products and solutions for Internet of Things.
In July and August 2023, Kontron acquired Comlab AG (a Swiss company manufacturing data communication repeaters for railways), Hartmann and W-IE-NE-R group of companies from Phoenix Mecano, and Cellular Automotive Module Unit from Telit Cinterion. In September 2023, it was announced that Kontron acquired Altimate, the Bucharest-headquartered software company specialising in traffic control, automated fare collection, tolling, and enforcement of traffic violations.
, the subsidiaries of the group include:
Kontron Europe
Kontron Bulgaria
Kontron AIS
susietec
Kontron Technologies
Kontron Transportation
Kontron Slovenia
Kontron Medical
S&T Medtech
Smart Metering
Solutions for Power Systems
Kontron ODM/EMS Alliance
Kontron Services Austria
Kontron Hungary
Kontron Services Romania
Kontron Slovenia
Kontron Americas
Kontron Asia
See also
Kontron Group
References
Computer companies of Germany
Companies based in Augsburg
Computer companies established in 1959
Computer hardware companies
Computer systems companies
Electronics companies established in 1959
Multinational companies headquartered in Germany
German brands
Companies listed on the Frankfurt Stock Exchange | Kontron | [
"Technology"
] | 612 | [
"Computer hardware companies",
"Computer systems companies",
"Computers",
"Computer systems"
] |
11,759,876 | https://en.wikipedia.org/wiki/Radial%20immunodiffusion | Radial immunodiffusion (RID), Mancini immunodiffusion or single radial immunodiffusion assay, is an immunodiffusion technique used in immunology to determine the quantity or concentration of an antigen in a sample.
Description
Preparation
A solution containing antibody is added to a heated medium such as agar or agarose dissolved in buffered normal saline. The molten medium is then poured onto a microscope slide or into an open container, such as a Petri dish, and allowed to cool and form a gel. A solution containing the antigen is then placed in a well that is punched into the gel. The slide or container is then covered, closed or placed in a humidity box to prevent evaporation.
The antigen diffuses radially into the medium, forming a circle of precipitin that marks the boundary between the antibody and the antigen. The diameter of the circle increases with time as the antigen diffuses into the medium, reacts with the antibody, and forms insoluble precipitin complexes. The antigen is quantitated by measuring the diameter of the precipitin circle and comparing it with the diameters of precipitin circles formed by known quantities or concentrations of the antigen.
Antigen-antibody complexes are small and soluble when in antigen excess. Therefore, precipitation near the center of the circle is usually less dense than it is near the circle's outer edge, where antigen is less concentrated.
Expansion of the circle reaches an endpoint and stops when free antigen is depleted and when antigen and antibody reach equivalence. However, the clarity and density of the circle's outer edge may continue to increase after the circle stops expanding.
Interpretation
For most antigens, the area and the square of the diameter of the circle at the circle's endpoint are directly proportional to the initial quantity of antigen and are inversely proportional to the concentration of antibody. Therefore, a graph that compares the quantities or concentrations of antigen in the original samples with the areas or the squares of the diameters of the precipitin circles on a best-fit line plot will usually be a straight line after all circles have reached their endpoints (equivalence method).
Circles that small quantities of antigen create reach their endpoints before circles that large quantities create do so. Therefore, if areas or diameters of circles are measured while some, but not all, circles have stopped expanding, such a graph will be straight in the portion whose wells initially contained the smaller quantities or concentrations of antigen and will be curved in the portion whose wells contained the larger quantities or concentrations.
While circles are still expanding, a graph that compares the initial quantities or concentrations of the antigen on a logarithmic scale with the diameters or areas of the circles on a linear scale may be a straight line (kinetic method). However, circles of the precipitate are smaller and less distinct during expansion than they are after expansion has ended. Further, temperature affects the rate of expansion, but does not affect the size of a circle at its endpoint. In addition, the range of circle diameters for the same initial quantities or concentrations of antigen is smaller while some circles are enlarging than they are after all circles have reached their endpoints.
The quantity and concentration of insoluble antigen-antibody complexes at the outer edge of the circle increase with time. The clarity and density of the circle's outer edge therefore also increase with time. As a result, measurements of the sizes of circles and graphs produced from these measurements are often more accurate after circles have stopped expanding than they are when circles are still enlarging. For those reasons, it is often more desirable to take measurements after all circles have reached their endpoints than it is to take measurements while some or all circles are still enlarging.
Measurements of large circles are more accurate than are those of small circles. It is therefore often desirable to adjust the concentration of antibody and the initial quantities of antigen to assure that precipitin rings will be large.
Radial immunodiffusion techniques
One can determine the antigen concentration in a sample whose concentration is unknown by finding its location on a graph that charts the diameters of precipitin circles produced by three or more reference samples with known antigen concentrations. Two techniques often produce straight lines on such graphs. The techniques produce those lines on different types of graphs.
The techniques and their graphs are:
Measuring circles while all are expanding (kinetic method): graph charting logarithms of initial antigen concentrations vs. diameters of precipitin circles on a best-fit semi-logarithmic plot.
Measuring circles after all reach their end points (equivalence method): graph charting initial antigen concentrations vs. squares of diameters of precipitin circles on a best-fit line plot.
Notes
References
Further reading
.
External links
Introductory video on radial immunodiffusion theory and technique (10:21 minutes).
Introductory video demonstrating radial immunodiffusion technique (3:43 minutes).
Introductory lecture/slideshow illustrating radial immunodiffusion theory and technique. (6:56 minutes)
Photograph of precipitin circles in a Petri dish during radial immunodiffusion.
Biological techniques and tools
Immunologic tests | Radial immunodiffusion | [
"Biology"
] | 1,073 | [
"Immunologic tests",
"nan"
] |
11,759,970 | https://en.wikipedia.org/wiki/Trail%20ethics | Trail ethics define appropriate ranges of behavior for hikers on a public trail. It is similar to both environmental ethics and human rights in that it deals with the shared interaction of humans and nature. There are multiple agencies and groups that support and encourage ethical behavior on trails.
Trail ethics applies to the use of trails, by pedestrians, dog walkers, hikers, backpackers, mountain bikers, equestrians, hunters, and off-road vehicles.
Etiquette
Sometimes conflicts can develop between different types of users of a trail or pathway. Etiquette has developed to minimize such interference. Examples include:
When two groups meet on a steep trail, a custom has developed in some areas whereby the group moving uphill has the right-of-way.
Trail users generally avoid making loud sounds, such as shouting or loud conversation, playing music, or the use of mobile phones.
Trail users tend to avoid impacting on the land through which they travel. Users can avoid impact by staying on established trails, and durable surfaces, not picking plants, or disturbing wildlife, and carrying garbage out. The Leave No Trace movement offers a set of guidelines for low-impact hiking: "Leave nothing but footprints. Take nothing but photos. Kill nothing but time. Keep nothing but memories".
The feeding of wild animals is dangerous and can cause harm to both the animals and to other people.
Mountain bikers must yield to both hikers and riders on horses (equestrians), unless the trail is clearly designated and marked for bike-only travel. Hikers yield to equestrians.
Trails in urban areas
Some cities have worked to add pathways for pedestrians and cyclists. This can reduce the amount of vehicle traffic in busy urban areas, and make visiting downtown areas more pleasant, There can be difficulties when a path is used by people travelling at different speeds, such as pedestrians, joggers, and cyclists, and the appropriate etiquette is not observed.
Off road vehicles
In the US off-road vehicle use on public land has been criticized by some members of the government and environmental organizations including the Sierra Club and The Wilderness Society. They have noted several consequences of illegal ORV use such as pollution, trail damage, erosion, land degradation, possible species extinction, and habitat destruction which can leave hiking trails impassable. ORV proponents argue that legal use taking place under planned access along with the multiple environment and trail conservation efforts by ORV groups will mitigate these issues. Groups such as the Blue-ribbon Coalition advocate Treadlightly, which is the responsible use of public lands used for off-road activities.
See also
Tread Lightly!
Leave No Trace
"Rules of the Trail" (as applied in Mountain biking)
Clean Trails
Conservation ethic
Environmental ethics
References
External links
Clean Trails
Trail Ethics - Ontario-based Codes
Trail ethics are provided by: Leave No Trace, Inc.
Trail Etiquette in the Age of Me
Environmental ethics
Ethics | Trail ethics | [
"Environmental_science"
] | 586 | [
"Environmental ethics"
] |
11,760,070 | https://en.wikipedia.org/wiki/NatCarb | The NatCarb geoportal provides access to geospatial information and tools concerning carbon sequestration in the United States.
External links
National Energy Technology Laboratory
Carbon Sequestration Regional Partnerships
References
Carr, T.R., P.M. Rich, and J.D. Bartley. 2007. The NATCARB geoportal: linking distributed data from the Carbon Sequestration Regional Partnerships. Journal of Map and Geography Libraries (Geoscapes), "Special Issue on Department of Energy (DOE) Geospatial Science Innovations". In Press.
Carbon capture and storage | NatCarb | [
"Engineering"
] | 122 | [
"Geoengineering",
"Carbon capture and storage"
] |
11,760,149 | https://en.wikipedia.org/wiki/Angle%20of%20climb | In aerodynamics, climb gradient is the ratio between distance travelled over the ground and altitude gained, and is expressed as a percentage. The angle of climb can be defined as the angle between a horizontal plane representing the Earth's surface, and the actual flight path followed by the aircraft during its ascent.
The speed of an aircraft type at which the angle of climb is largest is called VX. It is always slower than VY, the speed for the best rate of climb.
As the latter gives the quickest way for gaining altitude levels, regardless of the distance covered during such a maneuver, it is more relevant to cruising. The maximum angle of climb on the other hand is where the aircraft gains the most altitude in a given distance, regardless of the time needed for the maneuver. This is important for clearing an obstacle, and therefore is the speed a pilot uses when executing a "short field" takeoff.
VX increases with altitude, and VY decreases with altitude until they converge at the airplane's absolute ceiling.
Best angle of climb (BAOC) airspeed for an airplane is the speed at which the maximum excess thrust is available. Excess thrust is the difference between the total drag of the aircraft, and the thrust output of the powerplant. For a jet aircraft, this speed is very close to the speed at which the total minimum drag occurs.
See also
Rate of climb
References
Aerodynamics | Angle of climb | [
"Chemistry",
"Engineering"
] | 282 | [
"Aerospace engineering",
"Aerodynamics",
"Fluid dynamics stubs",
"Fluid dynamics"
] |
11,761,108 | https://en.wikipedia.org/wiki/Natural%20history%20of%20disease | The natural history of disease is the course a disease takes in individual people from its pathological onset ("inception") until its resolution (either through complete recovery or eventual death). The inception of a disease is not a firmly defined concept. The natural history of a disease is sometimes said to start at the moment of exposure to causal agents. Knowledge of the natural history of disease ranks alongside causal understanding in importance for disease prevention and control. Natural history of disease is one of the major elements of descriptive epidemiology.
As an example, the cartilage of the knee, trapeziometacarpal and other joints deteriorates with age in most humans (osteoarthritis). There are no disease-modifying treatments for osteoarthritis---no way to slow, arrest, or reverse this pathophysiological process. There are only palliative/symptomatic treatments such as analgesics and exercises. In contrast, consider rheumatoid arthritis, a systemic inflammatory disease that damages articular cartilage throughout the body. There are now treatments that can modify that auto-immune inflammatory process (immune modulating drugs) that can slow the progression of the disease. Because these medications can alter the natural history of disease, they are referred to as disease-modifying antirheumatic drugs.
The subclinical (pre-symptomatic) and clinical (symptomatic) evolution of disease is the natural progression of a disease without any medical intervention. It constitutes the course of biological events that occurs during the development of the origin of the diseases (etiologies) to its outcome, whether that be recovery, chronicity, or death.
In regards to the natural history of disease, the goal of the medical field is to discover all of the different phases and components of each pathological process in order to intervene as early as possible and change the course of the disease before it leads to the deterioration of a patient's health.
There are two complementary perspectives for characterizing the natural history of disease. The first is that of the family doctor, who, by means of detailed clinical histories of each patient, can determine the presence of and characteristics of any new health problems. In contrast to this individualized view, the second perspective is that of the epidemiologist, who, through a combination of health records and biostatistical data, can discover new diseases and their respective evolutions, which is more of a population view.
Phases of disease
Pre-pathogenic period
In the pre-pathogenic period, the disease originates, but the patient does not yet present clinical symptoms or changes in his/her cells, tissues, or organs. This phase is defined by the host conditions, the disease agent (such as microorganisms and pathogens), and the environment.
Pathogenic period
The pathogenic period is the phase in which there are changes in the patient's cells, tissues, or organs, but the patient still does not notice any symptoms or signs of disease. This is a subclinical phase that can be subdivided into two more phases:
Incubation period vs. latency period
In transmissible diseases (like the flu), we refer to this phase as the incubation period because it's the time in which microorganisms are multiplying and producing toxins. It's fast-evolving and can last hours to days.
However, in degenerative and chronic diseases (like osteoarthritis and dementia), we refer to this phase as the latency period because it has a very slow evolution that can last months to years.
Clinical period
The clinical period is when the patient finally presents clinical signs and symptoms. That is: when the disease is clinically expressed and the affected seek health care. During this phase, if the pathological process keeps evolving spontaneously without medical intervention, it will end in one of three ways: recovery, disability, or death. Additionally, this phase can be broken down into three different periods:
Prodromal: the first signs or symptoms appear, which indicates the clinical start of the disease.
Clinical: specific signs and symptoms appear, which allows the doctor to not only identify the disease but also determine the appropriate treatment in hopes of curing the patient or at least preventing long-term damages.
Resolution: the final phase in which the disease disappears, becomes chronic, or leads to death.
Types of prevention
The medical field has developed many different interventions to diagnose, prevent, treat, and rehabilitate the natural course of disease. In artificially changing this evolution of disease, doctors hope to prevent the death of their patients by either curing them or reducing their long-term effects.
Primary prevention
Primary prevention is a group of sanitary activities that are carried out by the community, government, and healthcare personnel before a particular disease appears. This includes:
Promotion of health, which is the encouragement and defense of the population's health through actions that fall upon individuals of the community, like, for example, anti-tobacco campaigns for preventing lung cancer and other illnesses associated with tobacco.
Specific protection of health, including environmental safety and food safety. While vaccinations are carried out by medical and nursing personnel, health promotion and protection activities that influence the environment are carried out by other public health professionals.
Chemical treatment, which consists of drug administration to prevent diseases. One example of this is the administration of estrogen in menopausal women to prevent osteoporosis.
According to WHO, one of the instruments of health promotion and prevention is health education, which further deals with the transmission of information, the personal skills, and the self-esteem necessary to adopt measures intended to improve health. Health education involves the spreading of information related not only to underlying social, economic, and environmental conditions that influence health but also to factors and behaviors that put patients at risk. In addition to this, communication about the use of the healthcare system is becoming increasingly more important to primary prevention.
Secondary prevention
Secondary prevention, also called premature diagnosis or premature screening, is an early detection program. More specifically, it's an epidemiological program of universal application that is used to detect serious illnesses in particular, asymptomatic populations during the pre-pathogenic period. This form of prevention can be associated with an effective or curative treatment, and its goal is to reduce the mortality rate.
Secondary prevention is based on population screenings, and, in order to justify these screenings, the following predetermined conditions defined by Frame and Carlson in 1975 must be met:
That the disease represents an important health problem that produces noticeable effects on the quality and duration of one's life.
That the disease has a prolonged initial, asymptomatic phase and that its natural history is known.
That an effective treatment is available and accepted by the population in case the disease is found in the initial phase.
That a rapid, reliable, and easily conducted screening test is available, is well-accepted by doctors and patients, and has high sensitivity, specificity, and validity.
That the screening test is cost-effective.
That the early detection of the disease and its treatment during the asymptomatic period reduces global morbidity and/or mortality.
Tertiary prevention
Tertiary prevention is the patient's recovery once the disease has appeared. A treatment is administered in an attempt to cure or palliate the disease or some of its specific symptoms. The recovery and treatment of the patient is carried out both in primary care and in hospital care.
Tertiary prevention also occurs when a patient avoids a new contagion as a result of knowledge that he/she gained from having a different illness in the past.
Quaternary prevention
Quaternary prevention is the group of sanitary activities that mitigates or entirely bypasses the consequences of the health system's unnecessary or excessive interventions.
They are "the actions that are taken to identify patients at risk of overtreatment, to protect them from new medical interventions, and to suggest ethically acceptable alternatives." This concept is coined by the Belgian general physician, Marc Jamoulle, and is included in WONCA's Dictionary of General/Family Practice.
Example: Musculoskeletal diseases of senescence
Pre-pathogenic period
Musculoskeletal pathologies such as osteoarthritis of the knee or shoulder (rotator cuff) tendinopathy are aspects of normal human aging. Most humans eventually have evidence of these disease on imaging. In other words, they are diseases of senescence. In a sense, all humans are in the "pre-pathogenic period" for these diseases.
Pathogenic period
Latency period
Osteoarthritis and tendinopathy can remain unnoticed (asymptomatic) for years or even decades. For instance, when one shoulder with tendinopathy develops painful movement, imaging of the opposite symptom-free shoulder tends to identify comparable pathology.
Clinical period
Prodromal: The first time a person notices pain or stiffness associated with osteoarthritis or tendinopathy, it may be misperceived as a new pathology and even as an injury.
Clinical: There comes a time when the disease is symptomatic on most days and there may be deformity or stiffness (reduced motion). The person is now aware of the changes in their body. This may be a time of seeking medical advice or treatment.
Resolution: As with all diseases of senescence, there is an accommodation phase a person redefines their sense of self and no longer perceives the disease as needing active care. Another example would be presbyopia, or the need for reading glasses. Once a person understands that they need glasses to read, they adjust and this is no longer a medical problem.
Types of prevention
The concept of prevention does not apply to musculoskeletal diseases of senescence, because there are no disease modifying treatments, and the pathology seems relatively independent of environmental exposures such as activity level.
References
Bibliography
Cause (medicine)
Epidemiology | Natural history of disease | [
"Environmental_science"
] | 2,060 | [
"Epidemiology",
"Environmental social science"
] |
11,761,311 | https://en.wikipedia.org/wiki/Certified%20social%20engineering%20prevention%20specialist | Certified Social Engineering Prevention Specialist (CSEPS) refers to both an individual Mitnick Security Consulting certification and a broader professional certification program.
The CSEPS program currently offers one type of certification. To attain this certification, a candidate must attend a CSEPS training course and pass the exam proctored at completion.
The training program focuses primarily on how Social Engineering works through the use of numerous case histories and a detailed breakdown of the psychological principles related to influence. It more specifically focuses on how a malicious hacker or information thief uses Social Engineering and/or Pretexting to obtain illicit access to computer systems by duping employees, and what can be done to minimize social engineering based attacks in an organization.
The course and exam costs approximately US$2300.00 per person. The course is two days in length. The exams takes between 1 and 2 hours to complete and consists of between 50-90 multiple choice questions and an essay section dealing with specific actions taken to prevent Social Engineering in a proposed scenario.
The exam was first designed by Kevin Mitnick and Alexis Kasperavičius in 2004, with assistance from various experts in the psychology field.
In 2020 Mitnick partnered with security awareness training firm KnowBe4 and the CSEPS course material and components became the basis of the KnowBe4 Social Engineering Security Awareness Training program.
References
Professional titles and certifications
Information technology qualifications | Certified social engineering prevention specialist | [
"Technology"
] | 277 | [
"Computer occupations",
"Information technology qualifications"
] |
11,761,489 | https://en.wikipedia.org/wiki/B%C3%A1nh%20cu%E1%BB%91n | Bánh cuốn or Bánh quấn (, rolled cake) is a Vietnamese dish originating from Northern Vietnam.
In Vietnamese cuisine
Bánh cuốn is made from a thin, wide sheet of fermented rice batter filled with a mixture of cooked seasoned ground pork, minced wood ear mushroom, and minced shallots. Sides for this dish usually consist of chả lụa (Vietnamese pork sausage), sliced cucumber, and bean sprouts, with the dipping sauce, which is fish sauce, called nước chấm (fish sauce).
The rice sheet of bánh cuốn is extremely thin and delicate. It is made by steaming a slightly fermented rice batter on a cloth that is stretched over a pot of boiling water. It is a light dish and is generally eaten for breakfast everywhere in Vietnam. A different version of bánh cuốn, called bánh cuốn Thanh Trì and bánh cuốn làng Kênh, may be found in Thanh Trì, a southern district of Hanoi and Kênh village of Nam Định, an ancient village in the center of Nam Định city. Bánh cuốn Thanh Trì or Bánh cuốn làng Kênh are not rolls, but just rice sheets eaten with chả lụa, fried shallots, or prawns.
Bánh ướt is simply the unfilled rice sheet, and is typically served with bean sprouts, chopped lettuce, sliced cucumber, fresh basil and mint, fried shallots and onions, chả/giò lụa, and fish sauce.
In other countries
In regards to Vietnamese culture, Thai cuisine commonly refers to the dish as pak moh yuan (). Skilled food preparers will make each rice sheet extra thin with as much stuffing as possible. Rice sheets are usually made of arrowroot flour which gives a tapioca-like consistency. The dough may also be infused with naturally extracted herbs such as butterfly pea for blue shades and pandan for green shades. As for the stuffing, the most popular stuffing is ground pork with cilantro roots, pepper, garlic, shallots and preserved radish. Less common stuffing is chicken, mushroom, corn, coconut, bean sprouts, chives, etc. Vegetarian recipes are also available.
Pak moh yuan is often served with sauces and toppings. While sweet chili sauce is the standard, recipes from certain regions may also use seafood ingredients in their sauce. Coconut milk may be drizzled on top as a sweet option. The dish may be garnished with fried garlic and served with lettuce and fresh chili on the side.
Another variation known in Thai cuisine is khao phan (; lit. "rice wrap"). It is regarded a specialty of Uttaradit province where it is eaten freshly made in many variations, but also sun-dried. The dried versions often have spices added to them and are popularly used as a wrap for a spicy salad made with rice noodles and minced pork.
Gallery
Bánh ướt
Bánh ướt (, ), is a Vietnamese thin pancake wrapper consisting of rice noodle sheets, eaten with nước chấm, fried shallots, and a side of chả lụa (Vietnamese pork sausage).
See also
References
External links
Alice's Guide to Vietnamese Banh
Bánh cuốn on Hanoidelicious
Recipe for bánh cuốn in French: Bánh cuốn
Vietnamese rice dishes
Thai cuisine
Steamed foods
Fermented foods
Vietnamese noodle dishes
Bánh
Stuffed dishes | Bánh cuốn | [
"Biology"
] | 723 | [
"Fermented foods",
"Biotechnology products"
] |
11,761,825 | https://en.wikipedia.org/wiki/Jaroslav%20Josef%20Pol%C3%ADvka | Jaroslav Josef Polivka (20 April 1886 – 9 February 1960), Czech structural engineer who collaborated with Frank Lloyd Wright between 1946 and 1959.
Jaroslav Josef Polivka a.k.a. J. J. Polivka Civil Engineer was born in Prague in 1886. He received his undergraduate degree in structural engineering at the College of Technology in Prague in 1909. He then studied at the Federal Polytechnic Institute in Zurich, Switzerland and at the Prague Institute of Technology, where he earned a doctoral degree in 1917. After serving in the First World War, he opened his own architectural and engineering office in Prague and developed his skills in stress analysis of reinforced concrete, pre-stressed reinforced concrete and steel structures. Polivka became an expert in photo-elastic stress analysis, a technique that examines small-scale transparent models in polarized light.
In Prague Polivka worked together with avant-garde Czech architect Josef Havlíček on the Habich Building (1927–28) and Chicago Building (1927–28).
Polivka designed the structural frame of the Czech Pavilion at the Paris International Exhibition of 1937 collaborating with renown Czech architect, Jaromír Krejcar and Czech engineer René Wiesner. Two years later, he worked with Czech architect Kamil Roškot to design another Czech Pavilion at the 1939 New York World's Fair. In 1939 Polivka immigrated to the United States and took a position as research associate and lecturer at the University of California, Berkeley. In 1941, he and Victor di Suvero co-invented a structural design technique that received a patent for improvements in structures. Polivka with his son Milos translated into English Eduardo Torroja’s ‘Philosophy of Structures’ book published in 1958.
In 1946 Polivka began to work with Frank Lloyd Wright collaborating on several major projects until Wright's death in 1959. For Wright's projects Polivka performed stress analyses and investigations of specific building materials. They worked on a total of seven projects, two of which were built: the Johnson Wax Research Tower, 1946–1951 at Racine Wisconsin and the Guggenheim Museum, 1946–1959 in New York City for which Polivka managed to design out the gallery ramp perimeter columns initially required. Their other well-known design proposal was the reinforced concrete Butterfly Bridge (proposed at a world record span of 1000-ft) at the Southern Crossing of San Francisco Bay (1949–52).
Polivka performed the photoelasticity for the Podolsko Bridge is an arch bridge that spans the Vltava between Podolsko and Temešvár in Písek District, Czech Republic. At the time of its completion in 1943, it was the longest arch bridge in Czechoslovakia.
He died in Berkeley, California.
References
"Contractor Meets Close Design Tolerances in Building Long-Span Concrete Arch Bridge" J. J. Polivka, Civil Engineering, ASCE American Society of Civil Engineers January 1949
External links
Polivka archives at University at Buffalo, The State University of New York
University of California Berkeley
Structural engineers
Engineers from Prague
1886 births
1960 deaths
Frank Lloyd Wright
ETH Zurich alumni
UC Berkeley College of Engineering faculty
Czechoslovak engineers
Expatriates from Austria-Hungary in Switzerland
Czechoslovak emigrants to the United States | Jaroslav Josef Polívka | [
"Engineering"
] | 662 | [
"Structural engineering",
"Structural engineers"
] |
11,762,003 | https://en.wikipedia.org/wiki/BCODE | A bCODE is an identifier that can be sent to a mobile phone/device and used as a ticket/voucher/identification or other type of token. The bCODE is an SMS message that can be read electronically from the screen of a mobile device. Bcodes can be sent by text message, and as they are just a standard SMS they can be received on over 99% of all devices.
Bcodes have many uses such as advertising, loyalty programs, promotions, ticketing and more.
History
bCODE was developed by an Australian company from 2003 to 2005.
bCODE Technology
A bCODE is a simple SMS text message that looks something like this:
This text message is read from the screen of a mobile phone/device and decoded into a unique token ID. This ID can then be used to supply the consumer with their own unique experience.
References
External links
bCODE
Barcodes
Encodings
Automatic identification and data capture
Access control | BCODE | [
"Technology"
] | 191 | [
"Data",
"Automatic identification and data capture"
] |
11,762,174 | https://en.wikipedia.org/wiki/Ecological%20self | In environmental philosophy, ecological self is central to the school of Experiential Deep Ecology, which, based on the work of Norwegian philosopher Arne Næss, argues that through the process of self-actualisation, one transcends the notions of the individuated "egoic" self and arrives at a position of an ecological self. So long as one is working within the narrower concept of self, Næss argues, environmentally responsible behaviour is a form of altruism, a "doing good for the other", which historically has been a precarious ethical basis, usually involved in exhorting others to "be good". Næss argues that in his Ecosophy, the enlargement of the ego-self to the eco-self results in environmentally responsible behaviour as a form of self-interest.
Warwick Fox argued that Næss's philosophy was based upon a variety of "transpersonal ecology" in which self-interest was firmly embedded within the interest of the ecommunity ecosphere of which the self was eternally embedded
As deep ecologist John Seed has stated, "Deep ecology critiques the idea that we are the crown of creation, the measure of all being: that the world is a pyramid with humanity rightly on top, merely a resource, and that nature has instrumental value only". The concept of the Ecological Self goes beyond anthropocentrism, which, by contrast locates human concerns as the exclusive source of all value. It draws upon the Land Ethic of Aldo Leopold. Leopold argued that within conventional ethics, the land itself was considered only as property, occupying a role analogous to slavery in earlier societies that permitted the ownership of people. By comparison a land ethic enlarges the boundary of moral concern to include "soils, waters, plants, and animals, or collectively: the land". The basis of such a non-anthropocentric ethic, according to Leopold was that "A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise."
Like Thomas Berry and Brian Swimme, ecological philosopher Freya Mathews argues that in considering the ecological self, we need to look beyond the present to the "deep time" of ages past, in the evolution of life and the creation of the cosmos, in order to consider the real roots of human consciousness. Experiential deep ecologist Joanna Macy speaks of the Ecological Self in her book "World as Lover, World as Self", and uses the concept in her work on "Deep Time".
See also
Ecopsychology
Value-action gap
References
External links
"The Land Ethic" by Aldo Leopold
Earthprayer by John Seed
Deep ecology
Environmental ethics
Environmentalism
Self
Arne Næss | Ecological self | [
"Biology",
"Environmental_science"
] | 581 | [
"Biological hypotheses",
"Deep ecology",
"Biophilia hypothesis",
"Environmental ethics"
] |
11,763,157 | https://en.wikipedia.org/wiki/Asia-Pacific%20Journal%20of%20Chemical%20Engineering | The Asia-Pacific Journal of Chemical Engineering is a peer-reviewed scientific journal published by John Wiley & Sons on behalf of Curtin University of Technology. Until 2006 it was known as Developments in Chemical Engineering and Mineral Processing and published (in print only) by Curtin University of Technology. The current editor-in-chief is Moses O. Tadé (Curtin University of Technology).
Most cited papers
The three most-cited papers published by the journal are:
Research Article: Development of a novel autothermal reforming process and its economics for clean hydrogen production, Volume 1, Issue 1–2, Nov-Dec 2006, Pages: 5–12, Chen ZX, Elnashaie SSEH
Research Article: Review: examining the use of different feedstock for the production of biodiesel, Volume 2, Issue 5, Sep-Oct 2007, Pages: 480–486, Behzadi S, Farid MM
Research Article: The forces at work in colloidal self-assembly: a review on fundamental interactions between colloidal particles, Volume 3, Issue 3, May-Jun 2008, Pages: 255–268, Li Q, Jonas U, Zhao XS, et al.
References
External links
Chemical engineering journals
Academic journals established in 1993
Bimonthly journals
English-language journals
Wiley (publisher) academic journals | Asia-Pacific Journal of Chemical Engineering | [
"Chemistry",
"Engineering"
] | 271 | [
"Chemical engineering",
"Chemical engineering journals"
] |
11,763,255 | https://en.wikipedia.org/wiki/Applied%20Organometallic%20Chemistry | Applied Organometallic Chemistry is a monthly peer-reviewed scientific journal published since 1987 by John Wiley & Sons.
The editor-in-chief is Cornelis J. Elsevier (University of Amsterdam).
Contents
The journal includes:
reviews
full papers
communications
working methods papers
crystallographic reports
It also includes occasional reports on:
relevant conferences of applied work in the field of organometallics
including bioorganometallic chemistry
metal/organic ligand coordination chemistry.
Abstracting and indexing
The journal is abstracted and indexed in:
Biological Abstracts
BIOSIS Previews
Cambridge Structural Database
Chemical Abstracts Service
Ceramic Abstracts
ChemWeb
Compendex
Advanced Polymer Abstracts
Civil Engineering Abstracts
Mechanical & Transportation Engineering Abstracts
Current Contents/Physical
Chemical & Earth Sciences
Engineered Materials Abstracts
International Aerospace Abstracts
METADEX
PASCAL
Science Citation Index
Scopus
According to the Journal Citation Reports, the journal has a 2020 impact factor of 4.105.
Most cited papers
The three highest cited papers (> 250 citations each) are:
References
External links
Organic chemistry journals
Wiley (publisher) academic journals
Academic journals established in 1987
English-language journals
Monthly journals | Applied Organometallic Chemistry | [
"Chemistry"
] | 224 | [
"Organic chemistry journals"
] |
11,763,375 | https://en.wikipedia.org/wiki/Concatenated%20error%20correction%20code | In coding theory, concatenated codes form a class of error-correcting codes that are derived by combining an inner code and an outer code. They were conceived in 1966 by Dave Forney as a solution to the problem of finding a code that has both exponentially decreasing error probability with increasing block length and polynomial-time decoding complexity.
Concatenated codes became widely used in space communications in the 1970s.
Background
The field of channel coding is concerned with sending a stream of data at the highest possible rate over a given communications channel, and then decoding the original data reliably at the receiver, using encoding and decoding algorithms that are feasible to implement in a given technology.
Shannon's channel coding theorem shows that over many common channels there exist channel coding schemes that are able to transmit data reliably at all rates less than a certain threshold , called the channel capacity of the given channel. In fact, the probability of decoding error can be made to decrease exponentially as the block length of the coding scheme goes to infinity. However, the complexity of a naive optimum decoding scheme that simply computes the likelihood of every possible transmitted codeword increases exponentially with , so such an optimum decoder rapidly becomes infeasible.
In his doctoral thesis, Dave Forney showed that concatenated codes could be used to achieve exponentially decreasing error probabilities at all data rates less than capacity, with decoding complexity that increases only polynomially with the code block length.
Description
Let Cin be a [n, k, d] code, that is, a block code of length n, dimension k, minimum Hamming distance d, and rate r = k/n, over an alphabet A:
Let Cout be a [N, K, D] code over an alphabet B with |B| = |A|k symbols:
The inner code Cin takes one of |A|k = |B| possible inputs, encodes into an n-tuple over A, transmits, and decodes into one of |B| possible outputs. We regard this as a (super) channel which can transmit one symbol from the alphabet B. We use this channel N times to transmit each of the N symbols in a codeword of Cout. The concatenation of Cout (as outer code) with Cin (as inner code), denoted Cout∘Cin, is thus a code of length Nn over the alphabet A:
It maps each input message m = (m1, m2, ..., mK) to a codeword (Cin(m'1), Cin(m'2), ..., Cin(m'N)),
where (m'1, m'2, ..., m'N) = Cout(m1, m2, ..., mK).
The key insight in this approach is that if Cin is decoded using a maximum-likelihood approach (thus showing an exponentially decreasing error probability with increasing length), and Cout is a code with length N = 2nr that can be decoded in polynomial time of N, then the concatenated code can be decoded in polynomial time of its combined length n2nr = O(N⋅log(N)) and shows an exponentially decreasing error probability, even if Cin has exponential decoding complexity. This is discussed in more detail in section Decoding concatenated codes.
In a generalization of above concatenation, there are N possible inner codes Cin,i and the i-th symbol in a codeword of Cout is transmitted across the inner channel using the i-th inner code. The Justesen codes are examples of generalized concatenated codes, where the outer code is a Reed–Solomon code.
Properties
1. The distance of the concatenated code Cout∘Cin is at least dD, that is, it is a [nN, kK, D'] code with D' ≥ dD.
Proof:
Consider two different messages m1 ≠ m2 ∈ BK. Let Δ denote the distance between two codewords. Then
Thus, there are at least D positions in which the sequence of N symbols of the codewords Cout(m1) and Cout(m2) differ. For these positions, denoted i, we have
Consequently, there are at least d⋅D positions in the sequence of n⋅N symbols taken from the alphabet A in which the two codewords differ, and hence
2. If Cout and Cin are linear block codes, then Cout∘Cin is also a linear block code.
This property can be easily shown based on the idea of defining a generator matrix for the concatenated code in terms of the generator matrices of Cout and Cin.
Decoding concatenated codes
A natural concept for a decoding algorithm for concatenated codes is to first decode the inner code and then the outer code. For the algorithm to be practical it must be polynomial-time in the final block length. Consider that there is a polynomial-time unique decoding algorithm for the outer code. Now we have to find a polynomial-time decoding algorithm for the inner code. It is understood that polynomial running time here means that running time is polynomial in the final block length. The main idea is that if the inner block length is selected to be logarithmic in the size of the outer code then the decoding algorithm for the inner code may run in exponential time of the inner block length, and we can thus use an exponential-time but optimal maximum likelihood decoder (MLD) for the inner code.
In detail, let the input to the decoder be the vector y = (y1, ..., yN) ∈ (An)N. Then the decoding algorithm is a two-step process:
Use the MLD of the inner code Cin to reconstruct a set of inner code words y' = (y'1, ..., y'N), with y'i = MLDCin(yi), 1 ≤ i ≤ N.
Run the unique decoding algorithm for Cout on y'.
Now, the time complexity of the first step is O(N⋅exp(n)), where n = O(log(N)) is the inner block length. In other words, it is NO(1) (i.e., polynomial-time) in terms of the outer block length N. As the outer decoding algorithm in step two is assumed to run in polynomial time the complexity of the overall decoding algorithm is polynomial-time as well.
Remarks
The decoding algorithm described above can be used to correct all errors up to less than dD/4 in number. Using minimum distance decoding, the outer decoder can correct all inputs y' with less than D/2 symbols y'i in error. Similarly, the inner code can reliably correct an input yi if less than d/2 inner symbols are erroneous. Thus, for an outer symbol y'i to be incorrect after inner decoding at least d/2 inner symbols must have been in error, and for the outer code to fail this must have happened for at least D/2 outer symbols. Consequently, the total number of inner symbols that must be received incorrectly for the concatenated code to fail must be at least d/2⋅D/2 = dD/4.
The algorithm also works if the inner codes are different, e.g., for Justesen codes. The generalized minimum distance algorithm, developed by Forney, can be used to correct up to dD/2 errors.
It uses erasure information from the inner code to improve performance of the outer code, and was the first example of an algorithm using soft-decision decoding.
Applications
Although a simple concatenation scheme was implemented already for the 1971 Mariner Mars orbiter mission, concatenated codes were starting to be regularly used for deep space communication with the Voyager program, which launched two space probes in 1977. Since then, concatenated codes became the workhorse for efficient error correction coding, and stayed so at least until the invention of turbo codes and LDPC codes.
Typically, the inner code is not a block code but a soft-decision convolutional Viterbi-decoded code with a short constraint length.
For the outer code, a longer hard-decision block code, frequently a Reed-Solomon code with eight-bit symbols, is used.
The larger symbol size makes the outer code more robust to error bursts that can occur due to channel impairments, and also because erroneous output of the convolutional code itself is bursty. An interleaving layer is usually added between the two codes to spread error bursts across a wider range.
The combination of an inner Viterbi convolutional code with an outer Reed–Solomon code (known as an RSV code) was first used in Voyager 2, and it became a popular construction both within and outside of the space sector. It is still notably used today for satellite communications, such as the DVB-S digital television broadcast standard.
In a looser sense, any (serial) combination of two or more codes may be referred to as a concatenated code. For example, within the DVB-S2 standard, a highly efficient LDPC code is combined with an algebraic outer code in order to remove any resilient errors left over from the inner LDPC code due to its inherent error floor.
A simple concatenation scheme is also used on the compact disc (CD), where an interleaving layer between two Reed–Solomon codes of different sizes spreads errors across various blocks.
Turbo codes: A parallel concatenation approach
The description above is given for what is now called a serially concatenated code. Turbo codes, as described first in 1993, implemented a parallel concatenation of two convolutional codes, with an interleaver between the two codes and an iterative decoder that passes information forth and back between the codes. This design has a better performance than any previously conceived concatenated codes.
However, a key aspect of turbo codes is their iterated decoding approach. Iterated decoding is now also applied to serial concatenations in order to achieve higher coding gains, such as within serially concatenated convolutional codes (SCCCs). An early form of iterated decoding was implemented with two to five iterations in the "Galileo code" of the Galileo space probe.
See also
Gilbert–Varshamov bound
Justesen code
Singleton bound
Zyablov bound
References
Further reading
External links
University at Buffalo Lecture Notes on Coding Theory – Dr. Atri Rudra
Error detection and correction
Coding theory
Finite fields
Information theory | Concatenated error correction code | [
"Mathematics",
"Technology",
"Engineering"
] | 2,225 | [
"Discrete mathematics",
"Coding theory",
"Telecommunications engineering",
"Reliability engineering",
"Applied mathematics",
"Error detection and correction",
"Computer science",
"Information theory"
] |
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