|
PVA 75th Anniversary Logo 4C
PVA may refer to: Science and technology * Paraventricular nucleus of hypothalamus, a part of the brain * Patterned vertical alignment, a thin-film-transistor liquid-crystal display technology * Poikiloderma vasculare atrophicans, a skin disease * Polyvinyl acetate, an adhesive used for porous materials like wood, paper, and cloth * Polyvinyl alcohol, a water-soluble synthetic polymer * Population viability analysis, a risk-assessment method used in conservation biology * Positive vorticity advection in meteorology * Potato virus A, an agricultural disease Other uses * Paralyzed Veterans of America, a veterans' service organization * Kinder High School for the Performing and Visual Arts, in Houston, Texas, U.S. * Perkiomen Valley Academy, in Pennsylvania, U.S. * People's Volunteer Army The People's Volunteer Army (PVA) was the armed expeditionary forces deployed by the People's Republic of China during the Korean War. Although all units in the PVA were actually trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraventricular Nucleus Of Hypothalamus
The paraventricular nucleus (PVN, PVA, or PVH) is a nucleus in the hypothalamus. Anatomically, it is adjacent to the third ventricle and many of its neurons project to the posterior pituitary. These projecting neurons secrete oxytocin and a smaller amount of vasopressin, otherwise the nucleus also secretes corticotropin-releasing hormone (CRH) and thyrotropin-releasing hormone (TRH). CRH and TRH are secreted into the hypophyseal portal system and act on different targets neurons in the anterior pituitary. PVN is thought to mediate many diverse functions through these different hormones, including osmoregulation, appetite, and the response of the body to stress. Location The paraventricular nucleus lies adjacent to the third ventricle. It lies within the periventricular zone and is not to be confused with the periventricular nucleus, which occupies a more medial position, beneath the third ventricle. The PVN is highly vascularised and is protected by the blood–brain barrier, alt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thin-film-transistor Liquid-crystal Display
A thin-film-transistor liquid-crystal display (TFT LCD) is a variant of a liquid-crystal display that uses thin-film-transistor technology to improve image qualities such as addressability and contrast. A TFT LCD is an active matrix LCD, in contrast to passive matrix LCDs or simple, direct-driven (i.e. with segments directly connected to electronics outside the LCD) LCDs with a few segments. TFT LCDs are used in appliances including television sets, computer monitors, mobile phones, handheld devices, video game systems, personal digital assistants, navigation systems, projectors, and dashboards in automobiles. History In February 1957, John Wallmark of RCA filed a patent for a thin film MOSFET. Paul K. Weimer, also of RCA implemented Wallmark's ideas and developed the thin-film transistor (TFT) in 1962, a type of MOSFET distinct from the standard bulk MOSFET. It was made with thin films of cadmium selenide and cadmium sulfide. The idea of a TFT-based liquid-crystal disp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poikiloderma Vasculare Atrophicans
Poikiloderma vasculare atrophicans (PVA), is a cutaneous condition (skin disease) characterized by hypo- or hyperpigmentation (diminished or heightened skin pigmentation, respectively), telangiectasia and skin atrophy. Other names for the condition include prereticulotic poikiloderma and atrophic parapsoriasis. The condition was first described by pioneer American pediatrician Abraham Jacobi in 1906. PVA causes areas of affected skin to appear speckled red and inflamed, yellowish and/or brown, gray or grayish-black, with scaling and a thinness that may be described as "cigarette paper". On the surface of the skin, these areas may range in size from small patches, to plaques (larger, raised areas), to neoplasms (spreading, tumor-like growths on the skin). Mycosis fungoides, a type of skin lymphoma, may be a cause of PVA. The condition may also be caused by, associated with or accompany any of the following conditions or disorders: other skin lymphomas, dermatomyositis, lupus erythe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyvinyl Acetate
Polyvinyl acetate (PVA, PVAc, poly(ethenyl ethanoate)), commonly known as wood glue, PVA glue, white glue, carpenter's glue, school glue, or Elmer's glue in the US, is a widely available adhesive used for porous materials like wood, paper, and cloth. An aliphatic rubbery synthetic polymer with the formula (C4H6O2)''n'', it belongs to the polyvinyl ester family, with the general formula − COOCHCH2ˆ’. It is a type of thermoplastic. Properties The degree of polymerization of polyvinyl acetate is typically 100 to 5000, while its ester groups are sensitive to base hydrolysis and slowly convert PVAc into polyvinyl alcohol and acetic acid. The glass transition temperature of polyvinyl acetate is between 30 and 45 °C depending on the molecular weight. PVAc dispersions such as Elmer's Glue-All contain polyvinyl alcohol as a protective colloid. In alkaline conditions, boron compounds such as boric acid or borax cause the polyvinyl alcohol to cross-link, forming tac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyvinyl Alcohol
Poly(vinyl alcohol) (PVOH, PVA, or PVAl) is a water-soluble synthetic polymer. It has the idealized formula H2CH(OH)sub>''n''. It is used in papermaking, textile warp sizing, as a thickener and emulsion stabilizer in polyvinyl acetate (PVAc) adhesive formulations, in a variety of coatings, and 3D printing. It is colourless (white) and odorless. It is commonly supplied as beads or as solutions in water. Without an externally added crosslinking agent, PVA solution can be gelled through repeated freezing-thawing, yielding highly strong, ultrapure, biocompatible hydrogels which have been used for a variety of applications such as vascular stents, cartilages, contact lenses, etc. Uses PVA is used in a variety of medical applications because of its biocompatibility, low tendency for protein adhesion, and low toxicity. Specific uses include cartilage replacements, contact lenses, and eye drops. Polyvinyl alcohol is used as an aid in suspension polymerizations. Its largest applica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Viability Analysis
Population viability analysis (PVA) is a species-specific method of risk assessment frequently used in conservation biology. It is traditionally defined as the process that determines the probability that a population will go extinct within a given number of years. More recently, PVA has been described as a marriage of ecology and statistics that brings together species characteristics and environmental variability to forecast population health and extinction risk. Each PVA is individually developed for a target population or species, and consequently, each PVA is unique. The larger goal in mind when conducting a PVA is to ensure that the population of a species is self-sustaining over the long term. Uses Population viability analysis (PVA) is used to estimate the likelihood of a population’s extinction and indicate the urgency of recovery efforts, and identify key life stages or processes that should be the focus of recovery efforts. PVA is also used to identify factors that d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive Vorticity Advection
Positive vorticity advection, or PVA, is the result of more cyclonic values of vorticity advecting into lower values of vorticity. It is more generally referred to as "Cyclonic Vorticity Advection" (CVA). In the Northern Hemisphere this is positive, whilst in the Southern Hemisphere it is negative. Development Vorticity in the atmosphere is created in three different ways, which are named in their resultant vorticity. These are; Coriolis vorticity, curvature vorticity, and shear vorticity. For example, at the base of a trough, there is curvature and shear vorticity. Curvature vorticity is due to the increasing cyclonic turning as an air parcel enters the trough base. The maximum counter-clockwise spin (positive vorticity in the Northern Hemisphere) is at the trough base. Shear vorticity is caused by the difference in wind speed between air moving through the trough base (typically a jet or jet finger) and slower moving air on either poleward and equatorward side of the faster flo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potato Virus A
Potato virus A (PVA) is a plant pathogenic virus of the family ''Potyviridae''. See also * Viral diseases of potato Viral diseases of potato are a group of diseases caused by different types of viruses that affect potato crops worldwide and, although they do not affect human or animal health since they are viruses that only infect vegetables, they are a source o ... External linksICTVdB - The Universal Virus Database: Potato virus A Viral plant pathogens and diseases Potyviruses {{Virus-plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paralyzed Veterans Of America
The Paralyzed Veterans of America is a veterans' service organization in the United States of America, founded in 1946. The organization holds 33 chapters and 70 National Service Offices in the United States and Puerto Rico. It is based in Washington, D.C. The organization was founded in 1946 by a band of service members who came home from World War II with spinal cord injuries. These service members wanted to live with independence and dignity and as contributors to society, so they created the organization to be governed by its members, veterans of the armed forces living with spinal cord injury or disease such as multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease. PVA's team of legislative advocates, architects, medical professionals, lawyers, and other highly trained professionals strives to ensure that every veteran regains the freedom, independence, and quality of life they fought for. The organization is a major support ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinder High School For The Performing And Visual Arts
Kinder High School for the Performing and Visual Arts (Kinder HSPVA, HSPVA or PVA) is a secondary school located at 790 Austin Street in the downtown district of Houston, Texas. The school is a part of the Houston Independent School District. The school educates grades nine through twelve. The school is divided into six departments: instrumental music, vocal music, dance, theater (including technical theater), visual arts, and creative writing. HSPVA was placed as the top school in the Greater Houston Area by Children at Risk's 2009 annual ranking of high schools, and it has continued to be ranked as an "A" grade or higher by Children at Risk. Since 2003, HSPVA has had eight students named US Presidential Scholars in the Arts (Presidential Scholars Program) by the US Department of Education as selected by the National YoungArts Foundation ( YoungArts). As a Magnet school, HSPVA does not automatically enroll students from the surrounding neighborhood; the surrounding neighb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perkiomen Valley Academy
The Perkiomen Valley Academy (PVA) day-treatment program is one of several individual treatment and alternative educational centers for adolescents in Montgomery County, Pennsylvania. The program serves twelve- to eighteen-year-old students from the eight school districts located in western Montgomery County. Origin Originally established in 1976 as an alternative to institutionalization for socially maladjusted youth, PVA leased space in the Upper Perkiomen School District Administration Building. In June 1980, PVA made its home in a renovated tack shop on Route 73 in Obelisk, Pennsylvania. In August 1994, PVA relocated to its current education/recreation facility located on Hoffmansville Road in Frederick, Pennsylvania. Funding PVA received its first funding through a grant from the federal juvenile justice system. Students are currently referred by the Montgomery County Juvenile Probation Department, Montgomery County Office of Children and Youth, and the local school di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
People's Volunteer Army
The People's Volunteer Army (PVA) was the armed expeditionary forces deployed by the People's Republic of China during the Korean War. Although all units in the PVA were actually transferred from the People's Liberation Army under the orders of Chairman Mao Zedong, the PVA was separately constituted in order to prevent an official war with the United States. The PVA entered Korea on 19 October 1950, and completely withdrew by October 1958. The nominal commander and political commissar of the PVA was Peng Dehuai before the ceasefire agreement in 1953, although both Chen Geng and Deng Hua served as the acting commander and commissar after April 1952 due to Peng's illness. The initial (25 October – 5 November 1950) units in the PVA included 38th, 39th, 40th, 42nd, 50th, 66th Corps; totalling 250,000 men. About 3 million Chinese civilian and military personnel had served in Korea throughout the war. Background Although the United Nations Command (UN) forces were under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
