PAPER Topics

... to the cells of treated individuals. Yet with each passing decade, bacteria that defy not only single but multiple antibiotics -- and therefore are extremely difficult to control -- have become increasingly common. What is more, strains of at least three bacterial species capable of causing life-threatening illnesses (Enterococcus faecalis, Mycobacterium tuberculosis and Pseudomonas aeruginosa) already evade every antibiotic in the clinician's stockpile of more than 100 drugs. In part because of the rise in resistance to antibiotics, the death rates for some communicable diseases (such as tuberculosis) have started to rise again, after having declined in the industrial nations. How did w ...

... other words, the size and power of their reactions. The most typical form of is the mixture of sulfur, charcoal, and potassium nitrate. Another form of this powder is known as the brown form, this is a mixture of saltpeter, charcoal, and sulfur. These pieces tend to look like little hexagonal or octagonal milk chocolate pieces. However these can be modified in a way to form a more harsh explosion. This method is known as grading, were powder size is modified to hold a higher concentration of a particular substance. The charcoal used in such is considered to be ash from the wood of a willow. The different types of can be modeled in such ratios such as 6:5:5 or 6:5:2. Any considerab ...

... are used for rearing young, and the other dwelling burrow is used by both sexes as a place to rest, sleep and eat. Burrows have a problem with maintaining a flow of air through them. If a platypus stays in a burrow for too long it will begin to use up its supply of oxygen. The nesting burrow has an entrance above water level to increase oxygen supply, whereas the dwelling burrows are located below water level. has a bill like a duck, and a tail like a beaver. Some believe it is a cross between a duck, beaver, and fish. lays eggs and suckles its young. Roughly half the size of a household cat, the adult male’s average length is about 50cm and can weigh up to 2.4 kg. The female ...

... ozone layer. When these s do brake down, they released atomic chlorine which then would react with the ozone and convert it back into plain oxygen. The even worse part of all this is that these chlorine molecules do not become inactive after the first reaction with the ozone and would be available to destroy more ozone molecules. Thus this process would be the function of a catalyst; a single chlorine atom involved in a chain reaction to destroy many ozone molecules. Rowland and Molina eventually agreed that this thinning of the ozone shield can cause a catastrophe for Earth's living beings, including humans, by allowing large amounts of the deadly ultraviolet-B radiation to reach to Eart ...

... The body of a coral animal consists of a polyp, which is the living portion of the coral. A polyp is a hollow, cylindrical structure attached at one end to a surface, the other end is a mouth surrounded by tentacles which gather food and can sting prey to paralyse it. Polyps live in colonies, which grow from 1 to 7 inches, depending on the species. Coral polyps are classified as animals. Microscopic algae live within the animal tissues in a symbiotic relationship. The algae turn sunlight into carbon and sugars, which are then available to the polyp. In turn the polyp filters particles out of the water and excretes waste (nitrogen and phosphorus) that becomes available to the symbiotic alga ...

... are burned or felled at the rate of 1800 hectares (about 4500 acres) every hour! (Dwyer 39) Deforestation started hundreds of years ago, but only became a major problem in the second half of this century, when it increased dramatically. It was enhanced by the Brazilian government which started cutting down the forest to construct a vast network of highways in an effort to establish a good transportation system and improve Brazil's economy. The government wanted to encourage the country's development by transporting poor families from overpopulated areas of the country to Amazonia. Many poor people saw emigration into the Amazon as an opportunity to attain a higher standard of liv ...

... (y en la actualidad en pocos lugares en donde todavía se usa este tipo de pesticida), las dioxinas llegaron hasta nosotros no solo por el aire sino que directamente por los alimentos. Son lipofílicos, es decir solubles en las grasas y sus moléculas están unidas por enlaces fuertes que les dan una vida media entre los 7 y los 30 años, por esto se les llama moléculas persistentes. Existen una variedades de dioxinas, siendo las más tóxicas la 2,3,7,8 tetraclorodibenzodioxina (TCDD), la cual reúne a los Dibenzofuranos policlorados, las dibenzodioxinas policloradas y los bifenilos policlorados, más en general, hablando de dioxinas y furanos. Su estructura molecular es: Por to ...

... are rather common, but some people tend to experience some bizarre dreams. Early in the 20th century, Sigmund Freud believed that dream content was composed of the mental processes different from that used in the awake state. He believed this was what dominated the dreaming mind. He described this "process" as characterized by more primitive mechanisms, by rapid shifts in energy and emotion, and by a great deal of sexual and aggressive content derived from childhood. (Hartmann, E. 1997) There are 4 stages of sleep. The individual goes from awake to stage 1, then to 2, 3, and finally 4, the deepest stage of sleep. After spending about 20 minutes in stage 4, they return to stage ...

... isn't what we were designed for" (1). Everyone, at some point, has experienced the feelings that Wright describes. And with the pronoun ‘we' Wright tells his readers, ‘Yes, I have been through the same things.' This sort of statement is like a token of good will. The readers feel that Wright understands their plight and thus are more likely to listen to what he has to say. With this trust established, Wright moves on to the task of building confidence in his readers. He lives up to his title of science writer by providing various statistics ("As of 1993, 37% of Americans felt they could trust most people, down from 58% in 1960" (4).) and reporting the findings of numer ...

... chlorides. Chlorine also strongly reacts with nonmetals such as sulfur, phosphorus, and other halogens. If you were to mix hydrogen and chlorine gases and keep them in a cool dark place, the mixture would be stable, but if it were exposed to sunlight, it would cause a strong explosion. If a burning candle were placed in a sealed container of chlorine, it would keep burning, and it would produce thick, black, smoke, leaving behind soot. There are five oxides that chlorine can form: chlorine monoxide; dichloride monoxide; chlorine dioxide; chlorine heptoxide; and chlorine hexoxide. Chlorine is used in bleaching agents, disinfectants, monomers (plastics), solvents, and pesticides. It is also u ...