cholora essays

cholora essays Cholera is a bacterial disease caused through the alimentary route. This bacterium that cause is Vibria Cholerae. Where there is any environmental disaster including great floods, earthquakes and any other natural disaster there is likely to be an outbreak of Cholera. It is most commonly found in places such as Africa, southern and South East Asia and the Middle East but some isolated breaks have occurred in Australia, Japan, Europe and United States of America. Its mostly been found in lower socioeconomic groups and almost always in the warmer months. Humans seem to be the only receiver but there may be other animals that are affected by it. There is no known natural reservoir of the organism. In an endemic situation Children are the highest effected, and by early adulthood they acquire antibodies. If a region has not been affected by an epidemic but an out break then on most cases an adult is as venerable as a child. Although the symptoms are painless and acute, the victim will be affected by watery diarrhea, which is full of specks of mucus and epithelial cells which contain an enormous amount of vibros, and effortless vomiting. Because of this major loss of fluid most of the symptoms are ill efficient water related such as great thirst, weakness, wrinkled skin, sunken eyes, pinched facial expression, muscel cramps and cardiovascular problems, anuria and acidosis. If the victim is not constantly re-hydrated then symptoms such as collapses, shock and death may follow. The disease can be serious but also can lead to shock and kill you with in two to three hours. More commonly when the disease has its first outbreak it takes 3 to 4 hour for the body to be effected by shock and then another 18 hours to several days to die. The disease is spread or transmitted through feces or vomitus of a carrier with an all ready active infection. Outbreaks can be caused by contaminated water supplies, unhygienic hands, utensil ...

Prehistoric Life During the Permian Period

Prehistoric Life During the Permian Period The Permian period was, literally, a time of beginnings and endings. It was during the Permian that the strange therapsids, or mammal-like reptiles, first appearedand a population of therapsids went on to spawn the very first mammals of the ensuing Triassic period. However, the end of the Permian witnessed the most severe mass extinction in the history of the planet, even worse than the one that doomed the dinosaurs tens of millions of years later. The Permian was the last period of the Paleozoic Era (542-250 million years ago), preceded by the Cambrian, Ordovician, Silurian, Devonian and Carboniferous periods. Climate and Geography As during the preceding Carboniferous period, the climate of the Permian period was intimately linked with its geography. Most of the earths land mass remained locked up in the supercontinent of Pangea, with remote offshoots comprising present-day Siberia, Australia, and China. During the early Permian period, large portions of southern Pangea were covered by glaciers, but conditions warmed considerably by the beginning of the Triassic period, with the reappearance of vast rain forests at or near the equator. Ecosystems around the globe also became significantly drier, which spurred the evolution of new types of reptiles better adapted to cope with the arid climate. Terrestrial Life During the Permian Period Reptiles: The most important event of the Permian period was the rise of synapsid reptiles (an anatomical term denoting the appearance of a single hole in the skull, behind each eye). During the early Permian, these synapsids resembled crocodiles and even dinosaurs, as witness famous examples like Varanops and Dimetrodon. By the end of the Permian, a population of  synapsids had branched off into therapsids, or mammal-like reptiles; at the same time, the very first archosaurs appeared, diapsid reptiles characterized by the two holes in their skulls behind each eye. A quarter of a billion years ago, no one could have predicted that these archosaurs were destined to evolve into the very first dinosaurs of the Mesozoic Era, as well as pterosaurs and crocodiles!Amphibians: The increasingly dry conditions of the Permian period were not kind to prehistoric amphibians, which found themselves out-competed by more adaptable reptiles (which could venture further onto dry land to lay their to ugh-shelled eggs, whereas amphibians were constrained to living near bodies of water). Two of the most notable amphibians of the early Permian were the six-foot-long Eryops and the bizarre Diplocaulus, which looked like a tentacled boomerang. Insects: During the Permian period, conditions werent yet ripe for the explosion of insect forms seen during the ensuing Mesozoic Era. The most common insects were giant cockroaches, the tough exoskeletons of which gave these arthropods a selective advantage over other terrestrial invertebrates, as well as various types of dragonflies, which werent quite as impressive as their plus-sized forebears of the earlier Carboniferous period, like the foot-long Megalneura. Marine Life During the Permian Period The Permian period has yielded surprisingly few fossils of marine vertebrates; the best-attested genera are prehistoric sharks like Helicoprion and Xenacanthus and prehistoric fish like Acanthodes. (This doesnt mean the worlds oceans werent well-stocked with sharks and fish, but rather that the geologic conditions didnt lend themselves to the fossilization process.) Marine reptiles were extremely scarce, especially compared to their explosion in the ensuing Triassic period; one of the few identified examples is the mysterious Claudiosaurus. Plant Life During the Permian Period If youre not a paleobotanist, you may or may not be interested in the replacement of one weird variety of prehistoric plant  (the lycopods) by another weird variety of prehistoric plant (the glossopterids). Suffice it to say that the Permian witnessed the evolution of new varieties of seed plants, as well as the spread of ferns, conifers, and cycads (which were an essential source of food to the reptiles of the Mesozoic Era). The Permian-Triassic Extinction Everyone knows about the K/T Extinction Event that wiped out the dinosaurs 65 million years ago, but the most severe mass extinction in earths history was the one that transpired at the end of the Permian period, which annihilated 70 percent of terrestrial genera and a whopping 95 percent of marine genera. No one knows exactly what caused the Permian-Triassic Extinction, though a series of massive volcanic eruptions resulting in a depletion of atmospheric oxygen is the most likely culprit. It was this great dying at the end of the Permian that opened up the earths ecosystems to new kinds of terrestrial and marine reptiles, and led, in turn, to the evolution of dinosaurs.