... pero ya dejaron de ser efectivas pues algunas clases de insectos, lograron transformarse para que las dioxinas no surgieran un efecto mortífero en ellos y por tanto dejaron de ser efectivas. Esto llevó a que por algún tiempo (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 tóxi ...
... agreement was simply to coordinate research and technical activities related to the human genome. The initial planning process culminated in 1990 with the publication of a joint research plan, ‘Understanding Out Genetic Inheritance: The U.S. Human Genome Project the First Five Years FY 1991- 1995.' The goal of the HGP is to generate a series of tools that will change biological research. The complete nucleotide sequence of human DNA is approximately 50,000 to 100,000 genes in the human genome. The Human Genome Project estimated to take ten to twenty years to complete. During this time its anticipated that physical and genetic maps of the human genome will be ...
... and sick. Both the idealized wolf and the demonic wolf are creations of the human mind. It is not easy to transcend the image of the Big Bad Wolf that has filled our myths and legends, but if we know only this wolf we do not truly know the wolf at all. And what we do not know, we fear. Our fear is perhaps the greatest threat to the survival of the wolf, for it causes us to react rather than act, to repel rather than respect. But this fear and hatred did not always separate man and beast Man the hunter once looked on the wolf the hunter with admiration. Man and wolf both used their keen intelligence to overcome the disadvantages they faced in their day- ...
... energy, they are able to separate and to overcome the force of the atmospheric pressure and form the gas (water vapor) that makes up the bubbles you see in the boiling process. The standard temperature at which this occurs is 100 C or 212 F. In the very early stages of heating, you may see some small bubbles even though the water is only warm. This is some air that is dissolved in the cold water and is being expelled by the heating. This is not boiling. As the water nears the boiling point, some areas of the container close to the heat source may be hot enough to cause some boiling in that area which produces some local bubbles. To be sure that all of the ...
... each other ever since. Today the universe is still expanding, as astronomers have observed. The Steady State model says that the universe does not evolve or change in time. There was no beginning in the past, nor will there be change in the future. This model assumes the perfect cosmological principle. This principle says that the universe is the same everywhere on the large scale, at all times.2 It maintains the same average density of matter forever. There are observational evidences found that can prove the Big Bang model is more reasonable than the Steady State model. First, the redshifts of distant galaxies. Redshift is a Doppler effect which ...
... do not have any mass. Ideal gases obtain no volume unlike real gases which obtain small volumes. Also, since ideal gas particles excerpt no attractive forces, their collisions are elastic. Real gases excerpt small attractive forces. The pressure of an ideal gas is much greater than that of a real gas since its particles lack the attractive forces which hold the particles back when they collide. Therefore, they collide with less force. The differences between ideal gases and real gases can be viewed most clearly when the pressure is high, the temperature is low, the gas particles are large, and when the gas particles excerpt strong attractive forces. ...
... in the eighties and nineties (Brown, 15). These figures demonstrate that humanity is not effectively controlling and limiting its use of fossil fuels. As a result, acid rain falls upon the earth destroying what is left of the planet's forests and, an estimated 37 percent of the fish species that inhabit thelakes and streams of North America are either in jeopardy or extinct. A second indicator that displays humanity's misuse of technoscience is the global economy. Global economic statistics show the results of the applications of technoscience. In 1995, the global economy grew by an estimated 3.7 percent the largest gain since the 4.6 percent growth in 1980 (Brown ...
... alpha Ursa Majoris. Polaris, in the Little Dipper (Ursa Minor), is gamma (designated by the Greek lower-case letter gamma) Ursa Minoris, and Betelgeuse, in Orion, is gamma Orionis. VARIABLE STARS (those which periodically change in brightness) have lettered names, such as RR Lyrae in the constellation Lyra. Fainter stars are known by their numbers in a catalog; HD 12938 is the 12,938th star in the Henry Draper Catalogue. CHARACTERISTICS OF STARS Each star in the universe has its own position, motion, size, mass, chemical composition, and temperature. Some stars are grouped into clusters, and stars and star clusters are collected in the larger groupings called ...
... oceans are at risk. So just how much oil is put in the oceans? According to a study conducted by the World Research Institute, "…between 3 and 6 million tons of oil are discharged into the oceans every year" (Gorman 48). To put this in perspective, that is approximately 4 football stadiums filled to the top with oil. That is just every year…and this has been going on for more than a decade. In total, 45 million tons of oil in the past ten years that have been put into the oceans. There are several ways that oil ends up in the oceans. One method is through drilling accidents and another is through spillage from tankers and other transports. In 1990 alone, ...
... exploration. Advancements in rocketry after World War II enabled our machines to break the grip of Earth's gravity and travel to the Moon and to other planets. The United States has sent automated spacecraft, then human-crewed expeditions, to explore the Moon. Our automated machines have orbited and landed on Venus and Mars; explored the Sun's environment; observed comets, and made close-range surveys while flying past Mercury, Jupiter, Saturn, Uranus and Neptune. These travelers brought a quantum leap in our knowledge and understanding of the solar system. Through the electronic sight and other "senses" of our automated spacecraft, color and comp ...
