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    This is the new "temporary" Science & Technology forum

    Hello,

    Please feel free to post topics scientific and technological in this forum...been sanctioned from on high.

    I'll do my best to lure people in but going to be busy with work for a few days so please add to the science topics already here and add new ones so I can get my teeth sunk in with the rest of you in a few days.

    Thap.

    PS: Well better than nothing http://www3.pak.org/gupshup/smilies/smile.gif

    #2
    No. This is not the "Technology" forum. http://www3.pak.org/gupshup/smilies/smile.gif

    However, go ahead and discuss Science topics here. Lets see. http://www3.pak.org/gupshup/smilies/smile.gif

    Comment


      #3
      Pristine,

      Is this guessing game for my benefit?

      I was just told in my thread in the cafe that S&T related topics are to be moved here.

      "Lets see"......doesn't sound very encouraging!!!...

      Pull some strings P and get a forum set up.

      Comment


        #4
        can u tell us the scientific events that took place between 1901-1905 http://www3.pak.org/gupshup/smilies/biggrin.gif

        Comment


          #5
          Well the chemist Linus Pauling and the physicist Werner Heisenberg, were both born in 1901.

          It's not a question and answer thread...there are other science/archeological topics in this forum go read em http://www3.pak.org/gupshup/smilies/smile.gif

          Comment


            #6
            Originally posted by Thap:
            Well the chemist Linus Pauling and the physicist Werner Heisenberg, were both born in 1901.
            was that a SCIENTIFIC event???

            sorry, i thought you were asking people if they any questions regarding science and stuff.

            and u still haven't told me how you figured out the concentration ratio of those firms http://www3.pak.org/gupshup/smilies/tongue.gif

            [This message has been edited by Farwa (edited November 30, 2001).]

            Comment


              #7
              was it right then?

              0.3 I mean http://www3.pak.org/gupshup/smilies/smile.gif

              Comment


                #8
                Thap don't tell Farwa anything coz she's asking for KasoTi game that is going on in Cafe.

                Comment


                  #9
                  Too bad he already told me http://www3.pak.org/gupshup/smilies/biggrin.gif

                  Comment


                    #10
                    Didn't know I was involved in espionage http://www3.pak.org/gupshup/smilies/redface.gif http://www3.pak.org/gupshup/smilies/smile.gif

                    Comment


                      #11
                      c

                      Comment


                        #12
                        Thap....stop making noise about the forum and start talking science. Unfortunately we have to justify the forum's need first.

                        Comment


                          #13
                          http://www.sciencenews.org/20011201/fob1.asp

                          Craft Probes Alien Planet's Atmosphere

                          Astronomers have long wondered what the atmospheres of planets beyond the solar system might be like. Researchers this week reported that they have now gotten their first whiff.

                          The new observations, the researchers say, demonstrate that telescopes will ultimately have the capability to measure the composition of a variety of extrasolar planets' atmospheres and search for chemical markers of life beyond Earth.

                          "This is a huge step forward in extrasolar-planet research and one of the biggest discoveries ever in planetary science," comments theorist Sara Seager of the Institute for Advanced Study in Princeton, N.J. "For the first time, we can start to understand what the atmospheres [of extrasolar planets] are made of."

                          In the new study, astronomers homed in on a hot, gaseous planet. It's about two-thirds as heavy as Jupiter and orbits the sunlike star HD 209458, located 150 light-years from Earth. Researchers were able to detect the atmosphere of the distant planet because it periodically passes directly between its parent star and Earth. During those times, light from the star travels through layers of the planet's outer atmosphere, so less light reaches Earth.

                          Using the Hubble Space Telescope, astronomers found that whenever the unseen planet crossed in front of the star, they detected a slight decrease in starlight of a particular wavelength. That wavelength corresponds to the radiation absorbed by sodium atoms, which the researchers therefore say must be present in the planet's atmosphere.

                          The technique "is like looking at a very bright search light through a dense fog," explains Seager. "If some [wavelengths of the light] get more dimmed than others . . . we can tell what the fog is made of."

                          David Charbonneau of the California Institute of Technology in Pasadena and Timothy M. Brown of the National Center for Atmospheric Research in Boulder, Colo., announced the findings on Nov. 27 in Washington, D.C. Their team will report the study in the Astrophysical Journal.

                          Charbonneau and his colleagues got their first inkling that they could study the planet's atmosphere in 1999, shortly after two other teams independently discovered the orbiting body. The two teams discerned the unseen planet by detecting the slight wobble it induces in the motion of its parent star. Residing much closer to the star than the distance at which Mercury orbits the sun, the planet whips around HD 209458 in just 3.52 days.

                          Soon after that discovery, Charbonneau, Brown, and another group of astronomers examined the star to see if its planet would periodically block some of the starlight. An observer can see that dip in brightness only if the plane in which the planet orbits is aligned edge on with respect to Earth. The body circling HD 209458 is the only known extrasolar planet to have that alignment. The dimming that researchers detected revealed the planet's mass and radius (SN: 11/20/99, p. 324: http://www.sciencenews.org/sn_arc99/11_20_99/fob1.htm).

                          The alignment, combined with the planet's proximity to its parent star, offered "a fantastic opportunity to learn about the planet's atmosphere," Charbonneau says.

                          The intense heat from HD 209458 keeps the planet's atmosphere inflated like a hot-air balloon. Seager and other researchers calculated that the atmosphere is tenuous enough that each time the planet passes in front of the star, some starlight filters through the atmosphere's outer layers rather than being blocked altogether.

                          Models suggest that planetary atmospheres contain only trace amounts of sodium. Nonetheless, Charbonneau's team searched for this element because even small amounts would absorb enough light to be detected by Hubble's spectrometer.

                          Hubble did detect a few parts per million of sodium, but that's considerably less than any of the models predicted. The atmosphere may simply contain less sodium than expected, notes Seager. Another explanation is that the alien planet's atmosphere contains dense, high-altitude clouds. These clouds would prevent starlight from penetrating deep into the atmosphere, where much of the sodium may lie.

                          Charbonneau, Brown, and their colleagues now plan to search for methane, water vapor, potassium, and other chemicals in the atmosphere.

                          The scorchingly hot planet circling HD 209458 isn't likely to support life. But astronomers can apply the same search technique to probe the atmospheres of cooler, more hospitable extrasolar planets. The atmospheres of these planets may contain oxygen and other chemicals produced by organisms, Charbonneau notes.

                          He emphasizes, however, that this method of studying planetary atmospheres works only if a planet passes directly in front of its star as seen from Earth. So-called hot Jupiters, such as the planet closely orbiting HD 209458, have about a 1 in 10 chance of having that alignment. The odds are much less for a planet that lies farther from its star because its orbit must be much more precisely aligned if starlight passing through the atmosphere is to reach Earth.

                          A network of telescopes that Charbonneau and his colleagues have just begun to use has the potential to find one correctly positioned planet each month, he estimates.

                          The group recently employed another method to study the atmosphere of the planet circling HD 209458. This time, the researchers used Hubble to measure the intensity of starlight reflected by the planet, rather than the amount transmitted through its atmosphere. The team is now analyzing the data to find variations in the intensity of the reflected light at several wavelengths. The observations may reveal the size of clouds and particles in the atmosphere, Charbonneau says.
                          Muslims are so good at dividing that they can divide the atom. If you see two Muslims, probably they belong to 3 parties.
                          Al-Ghazali

                          Comment


                            #14
                            http://www.newscientist.com/news/news.jsp?id=ns99991631

                            Predators key to forest survival

                            Greg Miller


                            A forest without predators may not be a forest for long - that is the ominous conclusion of a unique new study by an international team of scientists. The team has found that when predators vanish, herbivore populations can explode, leading to the mass destruction of plant life.

                            The team, led by John Terborgh of Duke University, conducted a census of the herbivores and trees on several islands in Lago Guri, a 4300 square kilometre lake in Venezuela that was created in 1986 when a river was dammed for hydroelectric power.

                            When the water rose, the smallest of the islands lost nearly all of the predatory animals that inhabit the mainland, such as jaguars, snakes and raptors. The situation provided a unique natural experiment to test two competing theories of how ecosystems are structured.

                            The so-called bottom-up theory, says, in effect, that the plants are in control. Proponents of this idea argue that the availability of edible plants determines how many herbivores an ecosystem can support, which in turn determines how many predators it can support.

                            The top-down theory, on the other hand, argues that the predators are in charge. They keep the herbivores in check, thereby determining the abundance of plants.


                            Population explosion


                            "Some theoretical ecologists have argued that these top-down effects aren't very important or very common," says Michael Pace of the Institute of Ecosystem Studies in Millbrook, New York. "But these kinds of observations are very hard to make in terrestrial ecosystems, which is why it's been so hard to tell."

                            Until now. The bottom-up theory predicts nothing much should have changed in the Lago Guri after the predators disappeared. But Terborgh's findings show that the absence of predators has had a profound effect on the islands' ecosystems.

                            His team found that herbivores such as howler monkeys, iguanas and leaf-cutter ants were 10 to 100 times more prevalent on the lake's six smallest islands than they were on the mainland. The density of young trees on these islands was less than half that on six larger islands in the lakes, which had retained some of their predators.


                            Back lash


                            Pace says the study illustrates nicely that top-down processes can shape ecosystems, at least in some situations. However, he adds that the pendulum could swing back to bottom-up forces if the herbivores gobble up all the edible plants on the islands. If that happens, the remaining plants could begin limiting animal populations.

                            The study's authors argue that predators play a key role in maintaining biodiversity. An overabundance of herbivores "threatens to reduce species-rich forests to an odd collection of herbivore-resistant plants," they write. "Along the way, much plant and animal diversity will probably be lost."

                            This process is already happening in North America, they say, where deer populations have ballooned, and in Malaysia, where wild pigs run rampant through some forests.
                            Muslims are so good at dividing that they can divide the atom. If you see two Muslims, probably they belong to 3 parties.
                            Al-Ghazali

                            Comment


                              #15
                              http://www.newscientist.com/news/news.jsp?id=ns99991627

                              Scientists raise spectre of gene-modified athletes

                              James Randerson


                              Gene doping, in which athletes could genetically modify themselves with performance enhancing DNA, will be almost impossible to detect according to Peter Schjerling at the Copenhagen Muscle Research Centre in Denmark.

                              And far-fetched as it may seem, we may be watching genetically-modified (GM) athletes as soon as the Beijing Olympics in 2008, according to Charles Yesalis, an expert in performance enhancing drugs at Pennsylvania State University. The predictions are being presented at the Genes in Sport Conference at University College London on Friday.

                              Schjerling believes cheats will avoid detection by injecting themselves with copies of genes naturally present in the body, such as those encoding growth factors or testosterone.

                              With so much at stake in competitions, athletes may be prepared to risk therapies that have not been fully tested, says Schjerling: "Gene doping may be available to athletes even faster than normal patients."


                              Blood booster


                              One possibility would be to inject the gene for erythropoietin (EPO), a protein that boosts red blood cell count. This allows an athlete's blood to carry more oxygen.

                              In 1998, a whole cycling team was thrown out of the Tour de France for using EPO. But while it is possible to spot the synthetic protein currently used by its molecular differences, EPO from introduced genes would be identical to natural EPO.

                              Another possible therapy that could be hijacked by the gene cheats is vascular endothelial growth factor (VEGF). Sanjay Rajagopalan and colleagues at the University of Michigan have used a GM virus to deliver the VEGF gene to patients with peripheral atherosclerotic disease. This painful disease results in the constriction of blood vessels to the limbs and can result in patients losing a limb.

                              The therapy boosts VEGF levels which widens blood vessels. But athletes could use the therapy to increase the blood supply to their muscles, in order to enhance performance.

                              This gene therapy technique employs the common cold virus to deliver the VEGF gene to cells, so even detecting the virus would not prove an athlete had been cheating.


                              Biological battle


                              Detection might be possible if an inserted gene was attached to a distinctive promoter - the genetic sequence that controls a gene's activity. However, the gene's uptake would be quite local, so to detect it you would have to take a muscle biopsy from the exact site of an injection - painful procedure with minimal chance of success.

                              Yesalis is extremely pessimistic about the International Olympic Committee's ability to keep tabs on the cheats. "There is a gross epidemic of drug use in sport at the moment, so why should I expect any great success against gene therapy" he says.

                              "Currently the battle is over who has the best chemists, in the future it will be who has the best gene therapists," he adds.
                              Muslims are so good at dividing that they can divide the atom. If you see two Muslims, probably they belong to 3 parties.
                              Al-Ghazali

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