An epoch, or era, is a fixed point of time, commonly selected on account of some remarkable event by which it has been distinguished, and which is made the beginning or determining point of a particular year from which all other years, whether preceding or ensuing, are computed. In the Christian countries, the creation and the birth of Christ are the most important of the historical epochs. The creation has formed the foundation of various chronologies, the chief of which are: 1. The epoch adopted by Bossuet, Ussher, and other Catholic and Protestant divines, which places the creation in 4004 BC. 2. The Era of Constantinople (adopted by Russia), which places it in 5508 BC. 3. The Era of Antioch, used until 284 AD, placed the creation 5502 BC. 4. The Era of Aexandria, which made the creation 5492 BC. This is also the Abyssinian Era. 5. The Jewish Era, which places the creation in 3760 BC.
The Greeks computed their time by periods of four years, called Olympiads, from the occurrence every fourth year of the Olympic games. The first Olympiad, being the year in which Coroebus was victor in the Olympic games, was in the year 776 BC.
The Romans dated from the supposed era of the foundation of their city (Ab Urbe Condita, A.U.C.), the 21st of April, in the third year of the sixth Olympiad, or 753 BC (according to some authorities 752 BC).
The Christian Era, or mode of computing from the birth of Christ as a starting-point, was first introduced in the 6th century, and was generally adopted by the year 1000. This event is believed to have taken place earlier, perhaps by four years, than the received date.
The Julian epoch, based on the coincidence of the solar, lunar, and indictional periods, is fixed at 4713 BC, and is the only epoch established on an astronomical basis.
The Mohammedan Era, or Hejira, commences on the 16th of July, 622, and the years are computed by lunar months.
The Chinese traditionally reckoned their time by cycles of 60 years. Instead of numbering them as we do, they traditionally gave a different name to every year in the cycle. Research Epoch
John Elwes was an English miser. He was born about 1712 ab dided in 1789. His own name was Meggot, but he changed it on succeeding to an estate left him by his uncle, Sir Harvey Elwes. He was educated at Westminter School, and in his younger days was noted for his skill in horsemanship and love of the chase. He was elected member for Berkshire in 1774. His fortune and parsimonious habits increased in equal ratio, and at his death in 1789 he left, besides entailed estates, a fortune of half a million to his two natural sons. Research John Elwes
Normal red blood cells are of four main groups in relation to their behaviour when mixed with bloodplasma (or serum) of another individual. Similarly the plasma (and serum) of each individual belongs to one of four groups. If cells of one group meet plasma of an 'incompatible' group, the cells stick together in blocks. These clumps obstruct blood vessels and may cause death. The interaction of the incompatible cells and plasma is called 'agglutination'. The provocative substance in the cells is called the agglutlnogen, while the defensive substance in the plasma is the agglutinin. A similar mechanism develops in relation to our immunity to infections by certain bacteria and viruses. In blood transfusion, the amount of plasma administered is small in relation to the large amount of plasma in the recipient's circulation. On the other hand, even a small quantity of cells given to a patient whose plasma will not tolerate that particular type of cell, will lead to clumping of the donor's cells in the recipient's blood vessels. The importance therefore lies in the cells of the donor and the plasma of the recipient.l Plasma and serum for this purpose are identical and the serum obtained when a small quantity of blood is allowed to clot is used for testing against the donor's red cells. In order to determine a patient's blood group, a small quantity of blood is obtained from a finger or ear prick and immediately mixed with citrate to prevent clotting; the cells are then tested against special serum of known groups. To obtain the patient's serum for cross-matching, 5 ml of blood is taken, by vein puncture, and allowed to clot.
The four common groups have been numbered variously. The Moss classification I, II, III, and IV was used extensively until the adoption of the International A, B, O classification, which describes the groups according to the presence or absence of the specific cell factors, which are of two types, A and B. Thus we have four blood groups in the international system. In the first of these, both cell factors are present but no serum factors. The serum factors are called anti-A and anti-B, and obviously the cellfactor A and the serum factor anti-A could not exist in the same person. The second group contains cellfactor A and serum factor anti-B. The third group contains cellfactor B with serum factor anti-A, and the fourth group contains neither cellfactor but both serum factors. The fourth group could therefore be given to any of the other groups and the cells, having no clumping factors, would be tolerated in any recipient. On the other hand, the first group with both cell factors could not be given to any other group. The terms universal donor, Group O (MossIV), and universal recipient, Group AB (MossI), were used to amplify the earlier grouping system. Transfusion with the wrong group of blood is usually fatal so that very great care has to be taken in the determination of the blood group, both of donor and recipient.
Since the 1950s hitherto unexplained incompatability was found to be due to the presence of other factors than the A, B, O, agglutinogens. The most important of these is the rhesus cellfactor. Certain monkeys (Rhesus species) have this factor naturally, but it is present in only 85 per cent of white people in England and America. The other 15 per cent - Rh negative - may become sensitized to Rh positive cells by repeated transfusion of Rh positive blood. A rhesus negative mother whose husband is ph positive may produce an Rh positive baby. A battle occurs between the unborn baby's cells and the mother's plasma. The baby may die before birth (miscarriage) or be born with very severe anaemia and jaundice. If born alive, the baby is treated by complete replacement of its blood to get rid of the mother' s sensitized Rh negative plasma. This is 'exsanguination-transfusion'. During the 1950s blood grouping in preparation for transfusion became a complex and very responsible task. In most hospitals it is undertaken by specialists - perhaps a pathologist or transfusion officer. During the 1980s as HIV paranoia spread, even more testing started to be done. Research Blood Groups
The AB-1 was a Brazilian two-seat tandem training sailplane first flown in 1965 at the Nova Iguacu Aero Club in Rio de Janeiro. The AB-1 was a braced high-wing monoplane of mixed wood and metal construction. Research AB-1
The Bloch MB 174 was a French light reconnaissance bomber of the Second World War that saw service with the Vichy French air force after the occupation of France. The Bloch MB 174 was powered by two Gnome-Rhone 14N-48/49 radial piston engines providing a top speed of 530 kmh and a range of 1285 km, depending upon payload. The Bloch MB 174 carried a crew of three and was armed with two 7.5 mm MAC 1934 M39 fixed forward-firing machine-guns in the wing leading edges, two 7.5 mm MAC 1934 trainable rearward-firing machine-guns on a SAMM AB-68 mounting in the dorsal position and three 7.5 mm MAC 1934 M39 trainable rearward-firing machine-guns in the ventral position, and up to 400 kg of bombs in a lower-fuselage weapons bay. Research Bloch MB 174
The Potez 63 was a French three-seater light-attack, army co-operation and tactical reconnaissance warplane of the Second World War, serving from 1939 to 1945. The Potez 63 was powered by two Gnome-Rhone 14M-4/5 radial piston engines each rated at 700 hp providing a top speed of 264 mph and a maximum range of 1500 km. It was armed with one 7.5 mm MAC 1934 fixed, forward-firing machine-gun under the central fuselage, one 7.5 mm MAC 1934 fixed, rearward-firing machine-gun in the rear fuselage, one 7.5 mm MAC 1934 trainable, rearward-firing machine-gun in the rear cockpit; or in the revised standard variant; three 7.5 mm MAC 1934 fixed, forward-firing machine-guns firing as one in the nose under the central fuselage, four 7.5 mm MAC 1934 fixed, forward-firing machine-guns in two optional two-gun under-wing packs, three 7.5 mm MAC 1934 M39 rearward-firing machine-guns in the rear fuselage, two 7.5 mm MAC 1934 trainable rearward-firing machine-guns on a SAM AB-68 mounting in the rear cockpit. Research Potez 63
Saab are a Swedish aircraft and automobile manufacturer, originally founded as Svenska Aeroplan AB at Trollhattan in 1937 for the development and production of military aircraft. In 1939 SAAB was amalgamated with the Aircraft Division of the Svenska Jarnvagsverkstaderna rolling stock factory in Linkoping which had been making military and civilian aircraft since 1930. Research Saab
SCA is an abbreviation for Shuttle Carrier Aircraft
SCA is an abbreviation for SCGCITE Authorization
SCA is an abbreviation for Self Controlled Assembly
SCA is an abbreviation for Service Cryptologic Agency
SCA is an abbreviation for Stabilization Control Amplifier
SCA is an abbreviation for Sub Contract Administrator
SCA is an abbreviation for Sequencer Control Assembly
SCA is an abbreviation for Small-Caliber Ammunition
SCA is an abbreviation for SubChannel Adapter
SCA is an abbreviation for Supersonic Cruising Aircraft
SCA is an abbreviation for SchipperkeClub of America
SCA is an abbreviation for School and College Ability
SCA is an abbreviation for Science Clubs of America
SCA is an abbreviation for Screen Composers Association
SCA is an abbreviation for Senior Citizens of America
SCA is an abbreviation for Shipbuilders Council of America
SCA is an abbreviation for Society of Consumer Affairs
SCA is an abbreviation for Soybean Council of America
SCA is an abbreviation for Speech Communication Association
SCA is an abbreviation for Stock Company Association
SCA is an abbreviation for Sub-Contract Authorization
SCA is an abbreviation for SuezCanal Authority
SCA is an abbreviation for Survey of College Achievement
SCA is an abbreviation for Svenska CelluloseAB
SCA is an abbreviation for Switzerland Cheese Association
SCA is an abbreviation for Synagogue Council of America Research SCA
AB is an abbreviation for Able Seaman
AB is an abbreviation for Able Bodied Seaman
AB is an abbreviation for Air Base
AB is an abbreviation for Airborne
AB is an abbreviation for Airman Basic
AB is an abbreviation for Alberta
AB is an abbreviation for Artium Baccalaureus
AB is an abbreviation for Assault Breaker
AB is an abbreviation for About
AB is an abbreviation for Abridgment
AB is an abbreviation for Army Board
AB is an abbreviation for Anchor Bolt
AB is an abbreviation for At Bat Research AB
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Ab
