.... to North America from Europe during the early 1800's. Europeans sailing to North America would fill their ships ballast with wet sand taken from shores of Europe, a habitat where purple loosestrife thrived. Upon arrival in North America the ballast would be dumped overboard on the shoreline. By 1830 the plant was well established along the New England seaboard. Purple loosestrife seeds were also found in sheep and livestock feed that was imported from Europe during this period. This new organism was introduced to a new habitat free from traditional parasites, predators and competitors, purple loosestrife thrived in the environmental conditions and .....

.... of the particle, however, is not the only factor that determines whether it will pass through the membrane. There is also the concentration gradient, which relates to the amount of a certain substance inside the cell as opposed to outside the cell. The further down the gradient, the lower the concentration of a substance. This brings into play the processes of diffusion, osmosis, and active transport, all of which involve only small simple molecules. Diffusion is the movement of a substance from a region of high concentration, to a region of low concentration of that substance. In other words, a movement down the concentration gradient. Osmosis is very simila .....

.... can greatly improve the economy of a nation. A comparison between the efficiency of the transportation systems of the United Stated and Japan points this out. In 1990 Americans spent 17.9 percent of the GNP on transportation, whereas the Japanese spent only 10.79 percent on transportation. This difference of nearly 7 percent, gives the Japanese economy much more money for investing in their future. Our Economy is not the only thing we should worry about, and it is also not the only thing that can be improved by the use of bicycles. There are several major problems that could be drastically reduced by the increased use of bicycles. Traffic would be a l .....

.... consisted of, one experimental and two control grids set up to determine differences between survival, growth, and reproduction in areas supplied with freshly cut white spruce (Picea glauca) and aspen (Populus tremuloides). Similar trends were obtained in all three areas: population size, survivorship, reproduction and growth. Between critical winters of 1981-1982 the experimental grid area lost 77% of its population as compared to 79% and 96% loss for the control grids. Determining the survival rates, the authors used mark-recapture techniques, it was found that probabilities for survivorship in experimental grid (0.79+0.10) were similar to that of c .....

.... methods may be used to prevent iron from rusting: (1) alloying the iron so that it will be chemically resistant to corrosion which is the most satisfactory method of the three but also is the most expensive. A good example of this method is stainless steel. (2) Coating the iron with a material that will react with the corroding substances more readily than the iron does which leads it to protect the iron from corroding. This method is also satisfactory but is also expensive. The most common example of this method is galvanizing, in which iron is covered with zinc. (3) Covering iron with an air proof and also a water proof substance. This method is the l .....

.... to the central nervous systeem exsit. People with attention deficit disorder ( ) are easily distracted, and may be unable to focus more than a few moments on mental tasks. . They lack the ability to block out noise. A simple noise can capture their attention. children are often in a state of confusion. They are poor at prioritizing, recognizing what is important, and making decisions based on reverent factors ( Taylor 15) While observing a child with for one hour a few key things stood out. The child failed to complete tasks assigned to him and he was unable to follow more than one instruction at a time. Attention Deficit Disorder affects social and fam .....

.... in sand near the shore and takes about thirty-six hours to dig itself out of the nest. When it is born it is the about the size of a child's hand. It eats the Portuguese Man of War, a very deadly jellyfish. It has very tough skin so it does not have to worry about getting stung by the jellyfish. It lives in the ocean all of its life and lays its eggs on the shore, when the babies are born they go on their own to their own life. The turtle lives in a type of weed which floats in the ocean drifting with the currents, the environment is very bad for the turtle since there is a lot of offshore dumping by ships, polluting the ocean. There is a total of thir .....

.... nuclear waste." The issue now is, how do we dispose of these nuclear wastes? Scientist have thought of several methods to dispose the nuclear by- products. They tried to chemically treat the waste and reuse it, but "that would cost a fortune". They thought of launching the waste into outer space but it too will cost a fortune. They tried to dump barrels filled with nuclear waste into the ocean but they started leaking. As you can see, there is a great need for a nuclear waste disposal site. These sites may sound frightening, but it may be the only way for us to dispose the devastation we had longed to create. In 1986, the decision for a nuclear waste deposi .....