In particle physics, a kaon called a K meson and denoted K, is any of a group of four mesons distinguished by a quantum number called strangeness. In the quark model they are understood to be bound states of a strange quark and an up or down antiquark. Kaons have proved to be a copious source of information on the nature of fundamental interactions since their discovery in cosmic rays in 1947, they were essential in establishing the foundations of the Standard Model of particle physics, such as the quark model of hadrons and the theory of quark mixing. Kaons have played a distinguished role in our understanding of fundamental conservation laws: CP violation, a phenomenon generating the observed matter–antimatter asymmetry of the universe, was discovered in the kaon system in 1964. Moreover, direct CP violation was discovered in the kaon decays in the early 2000s by the NA48 experiment at CERN and the KTeV experiment at Fermilab; the four kaons are: K−, negatively charged has mass 493.677±0.013 MeV and mean lifetime ×10−8 s.
K+ positively charged must have mass and lifetime equal to that of K−. Experimentally, the mass difference is 0.032±0.090 MeV, consistent with zero. K0, neutrally charged has mass 497.648±0.022 MeV. It has mean squared charge radius of −0.076±0.01 fm2. K0, neutrally charged has the same mass; as the quark model shows, assignments that the kaons form two doublets of isospin. One doublet of strangeness +1 contains the K+ and the K0; the antiparticles form the other doublet. See Notes on neutral kaons in the article List of mesons, neutral kaon mixing, below.^ Strong eigenstate. No definite lifetime.^ Weak eigenstate. Makeup is missing small CP–violating term.^ The mass of the K0L and K0S are given as that of the K0. However, it is known that a minute difference between the masses of the K0L and K0S on the order of 3.5×10−6 eV/c2 exists. Although the K0 and its antiparticle K0 are produced via the strong force, they decay weakly. Thus, once created the two are better thought of as superpositions of two weak eigenstates which have vastly different lifetimes: The long-lived neutral kaon is called the KL, decays into three pions, has a mean lifetime of 5.18×10−8 s.
The short-lived neutral kaon is called the KS, decays into two pions, has a mean lifetime 8.958×10−11 s. An experimental observation made in 1964 that K-longs decay into two pions was the discovery of CP violation. Main decay modes for K+: Decay modes for the K− are charge conjugates of the ones above; the discovery of hadrons with the internal quantum number "strangeness" marks the beginning of a most exciting epoch in particle physics that now, fifty years has not yet found its conclusion... by and large experiments have driven the development, that major discoveries came unexpectedly or against expectations expressed by theorists. — I. I. Bigi and A. I. Sanda, CP violation, In 1947, G. D. Rochester and Clifford Charles Butler of the University of Manchester published two cloud chamber photographs of cosmic ray-induced events, one showing what appeared to be a neutral particle decaying into two charged pions, one which appeared to be a charged particle decaying into a charged pion and something neutral.
The estimated mass of the new particles was rough, about half a proton's mass. More examples of these "V-particles" were slow in coming; the first breakthrough was obtained at Caltech, where a cloud chamber was taken up Mount Wilson, for greater cosmic ray exposure. In 1950, 30 charged and 4 neutral V-particles were reported. Inspired by this, numerous mountaintop observations were made over the next several years, by 1953, the following terminology was adopted: "L-meson" meant muon or pion. "K meson" meant a particle intermediate in mass between the nucleon. "Hyperon" meant any particle heavier than a nucleon. The decays were slow. However, production in pion-proton reactions proceeds much faster, with a time scale of 10−23 s; the problem of this mismatch was solved by Abraham Pais who postulated the new quantum number called "strangeness", conserved in strong interactions but violated by the weak interactions. Strange particles appear copiously due to "associated production" of a strange and an antistrange particle together.
It was soon shown that this could not be a multiplicative quantum number, because that would allow reactions which were never seen in the new synchrotrons which were commissioned in Brookhaven National Laboratory in 1953 and in the Lawrence Berkeley Laboratory in 1955. Two different decays were found for charged strange mesons: The intrinsic parity of a pion is P = −1, parity is a multiplicative quantum number. Therefore, the two final states have different parity, it was thought that the initial states should have different parities, hence be two distinct particles. However, with precise measurements, no difference was found between the masses and lifetimes of each indicating that they are the
Wbaldino Acosta was an Argentine politician who served as Governor of his province of San Juan. Acosta was a lawyer and was active in public life, heading the provincial boxing federation in 1978. In 1971 he had joined the important San Juan party, the Partido Bloquista, led by Leopoldo Bravo who served several times as Governor and Senator, he became active in politics in 1981 becoming a provincial minister in 1983 the Chief of Police. In 1987, Acosta was elected vice-governor of San Juan with Carlos Gómez Centurión. On 16 May 1999, Acosta was elected once again as vice-governor of San Juan accompanying the Renewal Crusade party's Alfredo Avelín who won with 55%, heading the list of the Alliance for Work and Education which would win the Presidency of Argentina the same year. Avelín's period in office was marked by economic turbulence and public unrest in San Juan, like the country as a whole. By 2001, provincial employees were not paid and the province had become insolvent. In 2002, Avelín was impeached and deposed as governor by a majority of provincial deputies following massive demonstrations.
Acosta's party had joined the opposition parties in deposing Acosta was made governor. He stood in the subsequent 2003 election but came third behind José Luis Gioja of the Justicialist Party, he subsequently opposed his party's decision to back Gioja and the national government of Néstor Kirchner. Acosta died aged 69 in 2007 following a brain haemorrhage, he had married Teresita Beatriz Zapata in 1970 and had three children
The Men's Freestyle 74 kg at the 1984 Summer Olympics as part of the wrestling program were held at the Anaheim Convention Center, California. The wrestlers are divided into 2 groups; the winner of each group decided by a double-elimination system. LegendTF — Won by Fall ST — Won by Technical Superiority, 12 points difference PP — Won by Points, 1-7 points difference, the loser with points PO — Won by Points, 1-7 points difference, the loser without points SP — Won by Points, 8-11 points difference, the loser with points SO — Won by Points, 8-11 points difference, the loser without points P0 — Won by Passivity, scoring zero points P1 — Won by Passivity, while leading by 1-7 points PS — Won by Passivity, while leading by 8-11 points DC — Won by Decision, 0-0 score PA — Won by Opponent Injury DQ — Won by Forfeit DNA — Did not appear L — Losses ER — Round of Elimination CP — Classification Points TP — Technical Points Dave Schultz Martin Knosp Šaban Sejdi Rajinder Singh Naomi Higuchi Han Myung-Woo Marc Mongeon Pekka Rauhala Official Report
Fasciola hepatica known as the common liver fluke or sheep liver fluke, is a parasitic trematode of the class Trematoda, phylum Platyhelminthes. It infects the livers including humans; the disease caused by the fluke is called fasciolosis or fascioliasis, a type of helminthiasis and has been classified as a neglected tropical disease. Fasciolosis is classified as a plant/food-borne trematode infection acquired through eating the parasite's metacercariae encysted on plants. F. hepatica, distributed worldwide, has been known as an important parasite of sheep and cattle for decades and causes significant economic losses in these livestock species, up to £23 million in the UK alone. Because of its large size and economic importance, it has been the subject of many scientific investigations and may be the best-known of any trematode species. F. hepatica's closest relative is Fasciola gigantica. These two flukes are sister species. Fasciola hepatica occurs in the liver of a definitive host and its lifecycle is indirect.
Definitive hosts of the fluke are cattle and buffaloes. Wild ruminants and other mammals, including humans, can act as definitive hosts as well; the life cycle of F. hepatica goes through the intermediate host and several environmental larval stages. Intermediate hosts of F. hepatica are air-breathing freshwater snails from the family Lymnaeidae. Although several lymnaeid species susceptible to F. hepatica have been described, the parasite develops only in one or two major species on each continent. Galba truncatula is the main snail host in Europe in Asia and South America. Lymnaea viator, L. neotropica, Pseudosuccinea columella, L. cubensis are most common intermediate hosts in Central and South America. Several other lymnaeid snails may be or experimentally infected with F. hepatica, but their role in transmission of the fluke is low. The list of lymnaeid snails that may serve as natural or experimental intermediate hosts of F. hepatica include: Austropeplea ollula Austropeplea tomentosa Austropeplea viridis Fossaria bulimoides Galba truncatula Lymnaea cousini Lymnaea cubensis Lymnaea diaphana Lymnaea humilis Lymnaea neotropica Lymnaea occulta Lymnaea stagnalis Lymnaea viatrix Omphiscola glabra Pseudosuccinea columella Radix auricularia Radix lagotis Radix natalensis Radix peregra Radix rubiginosa Stagnicola caperata Stagnicola fuscus Stagnicola palustris Stagnicola turriculaThe metacercariae are released from the freshwater snail as cercariae, form cysts on various surfaces including aquatic vegetation.
The mammalian host eats this vegetation and can become infected. Humans can acquire these infections through drinking contaminated water and eating freshwater plants such as watercress. Inside the duodenum of the mammalian host, the metacercariae are released from within their cysts. From the duodenum, they burrow into the peritoneal cavity, they migrate through the intestines and liver, into the bile ducts. Inside the bile ducts, they develop into an adult fluke. In humans, the time taken for F. hepatica to mature from metacercariae into an adult fluke is 3 to 4 months. The adult flukes can produce up to 25,000 eggs per fluke per day; these eggs are passed out into freshwater. Once in freshwater, the eggs become embryonated, allowing them to hatch as miracidia, which find a suitable intermediate snail host of the Lymnaeidae family. Inside this snail, the miracidia develop into sporocysts to rediae to cercariae; the cercariae are released from the snail to form metacercariae and the life cycle begins again.
Fasciola hepatica is one of the largest flukes of the world, reaching a length of 30 mm and a width of 13 mm. It is leaf-shaped, pointed at the back, wide in the front; the oral sucker is small but powerful and is located at the end of a cone-shape projection at the anterior end. The acetabulum is located at the anterior end; the outer surface of the fluke is called the tegument. This is composed of scleroprotein, its primary function is to protect the fluke from the destructive digestive system of the host, its used for renewal of the surface plasma membrane and the active uptake of nutrients, the uptake of some compounds make flukes more resistant to be killed by the digestive system of host. On the surface of the tegument are small spines; these spines are single-pointed just prior to the fluke entering the bile ducts, they become multipointed. At the anterior end of the fluke, the spines have between 10 and 15 points, whereas at the posterior end, they have up to 30 points; the tegument is a syncytial epithelium.
This means it is made from the fusion of many cells, each containing one nucleus, to produce a multinucleated cell membrane. In the case of F. hepatica, no nuclei are in the outer cytoplasm between the basal and apical membranes. Thus, this region is referred to as anucleate. Instead, the nuclei are found in the cell bodies known as tegumental cells, these connect to the outer cytoplasm via thin cytoplasmic strands; the tegumental cells contain the usual cytoplasmic organelles. The tegument plays a key role in the fluke's infection of the host. Studies have shown that certain parts of the tegument can suppress the immune response of the mammalian host; this means that the fluke is able to weaken the immune response, increase
The University of Kentucky College of Dentistry is the dental school of the University of Kentucky. It is located in the city of Lexington, United States, it is one of two dental schools in Kentucky. The University of Kentucky College of Dentistry was established in 1962. In addition to the Doctor of Dental Medicine degree, the University of Kentucky College of Dentistry offers postdoctoral programs in six fields of study: General Practice Dentistry Oral and Maxillofacial Surgery Orofacial Pain Orthodontics Pediatric Dentistry PeriodonticsAll seven programs hold current and full accreditation by the Commission on Dental Accreditation. Two departments and twelve divisions make up the college: Department of Oral Health Practice Division of Endodontics Division of Oral Diagnosis, Oral Medicine and Oral and Maxillofacial Radiology Division of Periodontology Division of Restorative Dentistry Division of Prosthodontics Department of Oral Health Science Division of Oral and Maxillofacial Surgery Division of Pediatric Dentistry Division of Adult Dentistry Division of Oral Pathology Division of Orofacial Pain Division of Orthodontics Division of Public Health Dentistry
Anthony Ingham was an English professional footballer who played more than 500 games in the Football League as a defender for Leeds United and Queens Park Rangers. He holds the appearance record for QPR. During the Second World War Ingham served in the Royal Navy, he completed an electrical apprenticeship while playing part-time for Harrogate Town, where he made his debut in 1939/40 at the age of 14. He signed for Leeds United in the summer of 1947, made his League debut for the club in October of the same year in a 3-2 defeat at West Bromwich Albion; however he played only for The Whites, joined Queens Park Rangers in June 1950 for a fee of £5,000. He made his debut against Doncaster Rovers in November 1950, retired 13 years having made a club record 548 appearances in all senior competitions, 514 in the League. After retiring as a player in May 1963, he held various positions with QPR and went on to become a director of the club. A function room at Loftus Road is named in Ingham's honour. On 21 April 2010, Tony Ingham died of an illness at the age of 85