18 by xiagong0815


                                                                                                                                       Just 20 minutes to younger muscles
                                                                                                                                            Just 20 minutes of this stuff a day can help keep your muscles young. We’re talking about exercise.Yep, the timeless physique
                                                                                                                                       is just minutes away. It appears that, regardless of age, 20 minutes may be all the daily exercise needed to somehow reverse age-
                                                                                                                                       related decline in muscle stem cells, those master cells critical to new muscle growth. Remember Jack LaLanne, the country’s first
                                                                                                                                       uberfit exercise guru who lived to the ripe old age of 96? Turns out he was really on to something. But don’t worry. You probably
                                                                                                                                       don’t have to become an exercise fanatic like Jack to keep your muscles regenerating as you grow older. In an animal study, just
                                                                                                                                       20 minutes on a treadmill 6 days a week was enough to bestow up to triple the number of stem cells produced in the test subjects.
                                                                                                                                       And those extra stem cells are likely behind the subsequent jump in new muscle fibers and additional muscle mass that those test
                                                                                                                                       subjects experienced as well. One other benefit: The older rats in the study also exhibited an uptick in “spontaneous locomotion”
                                                                                                                                       - a naturally occurring increase in their physical activity levels.
fridAY, August 26, 2011

Solar system not home to only
nine planets; it also recognizes five ‘dwarf planets’
               NEW YORK: For three-quarters of a century, school                                                                                                                                                     than four hours, making it one of the fastest-spinning bodies
           kids learned that our solar system has nine planets: Mer-                                                                                                                                                 in the solar system. This super-charged spin is responsible
           cury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune                                                                                                                                                for Haumea’s oblong shape, pushing the dwarf planet out-
           and Pluto.                                                                                                                                                                                                ward substantially at the equator.
               But things changed nearly five years ago, as reported in                                                                                                                                                   Scientists recently discovered that 75 percent of
           SPACE. On Aug. 24, 2006, the International Astronomical                                                                                                                                                   Haumea’s surface is covered with crystalline water ice, simi-
           Union (IAU) struck Pluto from the list, demoting it to the                                                                                                                                                lar to the stuff found in your freezer.
           newly created category of “dwarf planet.” The move was
           spurred by the discovery of multiple large bodies orbiting                                                                                                                                                                         Makemake
           even farther from the sun than distant Pluto - particularly an                                                                                                                                                Brown’s team also discovered Makemake, spotting the
           object called Eris, which appeared to be bigger than Pluto.                                                                                                                                               dwarf planet in 2005.
               As a result, the IAU came up with a new definition of                                                                                                                                                     Astronomers aren’t sure of Makemake’s exact size, but
           “planet”: A body that circles the sun without being some                                                                                                                                                  the dwarf planet is thought to be about three-quarters as big
           other object’s satellite, is large enough to be rounded by its                                                                                                                                            as Pluto. It’s therefore likely the third-largest dwarf planet,
           own gravity (but not so big that it begins to undergo nuclear                                                                                                                                             after Eris and Pluto.
           fusion, like a star) and has “cleared its neighborhood” of                                                                                                                                                    Makemake orbits the sun from slightly farther away
           most other orbiting bodies.                                                                                                                                                                               than Pluto, at an average distance of 4.26 billion miles, and
               Since Pluto shares orbital space with lots of other ob-                                                                                                                                               completes an orbit every 310 years or so.
           jects out in the Kuiper Belt - the ring of icy bodies beyond                                                                                                                                                  Makemake is the second-brightest Kuiper Belt object
           Neptune - it didn’t make the cut. So Pluto was newly classi-                                                                                                                                              (after Pluto) and can be seen with a high-end amateur tele-
           fied as a dwarf planet, which tend to be smaller than “true”                                                                                                                                              scope, according to the IAU.
           planets and fall short on the “clearing your neighborhood”                                                                                                                                                    Like Pluto and Eris, Makemake appears to be a reddish
           criterion. Although hundreds, or perhaps thousands, more                                                                                                                                                  color in the visible-light spectrum. Scientists think its sur-
           solar system bodies may eventually join the list, the IAU                                                                                                                                                 face is covered by a layer of frozen methane, and the distant
           officially recognizes just five dwarf planets at the moment.                                                                                                                                              world has no known moons.
           Here’s a brief tour of all five: Pluto, Eris, Haumea, Make-
           make and Ceres.                                                                                                                                                                                                                       Ceres
                                                                                                                                                                                                                         Ceres is the only dwarf planet not found in the freez-
                                       Pluto                                                                                                                                                                         ing cold, faraway Kuiper Belt. Rather, it orbits in the main
                Pluto was discovered by American Clyde Tombaugh in                                                                                                                                                   asteroid belt between Mars and Jupiter, completing one lap
           1930, as part of a search for the mythical “Planet X” that                                                                                                                                                around the sun every 4.6 years.
           was thought to be perturbing the orbit of Uranus.                   FILE-Artist’s rendering of Eris, announced in July 2005 by Mike Brown of Caltech. It is more massive than Pluto. The                      Ceres is by far the largest object in the asteroid belt, con-
                The dwarf planet was initially believed to be at least         sun is in the background. (Agencies)                                                                                                  taining about one-third of the belt’s mass. However, at 590
           the size of Earth, but astronomers now know that it’s about                                                                                                                                               miles across, it is the smallest known dwarf planet.
           1,455 miles across - less than 20 percent as big as our plan-      - composed mainly of nitrogen, methane and carbon mon-             considerably more rock (and less ice) than its Kuiper Belt              Because it’s so much closer to Earth than the other dwarf
           et. And Pluto is just 0.2 percent as massive as Earth.             oxide- that extends about 1,860 into space.                        neighbor. However, the surfaces of the two dwarf planets            planets, Ceres was discovered far earlier. Italian astronomer
                Pluto has an extremely elliptical orbit that’s not in the         Pluto will start coming into clearer focus in a few years’     appear to be similar, composed primarily of nitrogen ice.           Giuseppe Piazzi spotted it first, on Jan. 1, 1801. For the
           same plane as the eight official planets’ orbits. On average,      time. NASA’s New Horizons probe is due to make a close                                                                                 next half-century, many astronomers regarded Ceres as a
           the dwarf planet cruises around the sun at a distance of 3.65      flyby of the dwarf planet in July 2015, marking the first time                               Haumea                                    true planet.
           billion miles taking 248 years to complete one circuit.            a spacecraft has ever visited the frigid, faraway world.                Haumea, a Kuiper Belt denizen orbiting slightly beyond             That changed when it became apparent that Ceres was
                Because it’s so far from the sun, Pluto is one of the cold-                                                                      Pluto, was discovered by Brown and his team in late 2004.           just one of many bodies hurtling through space in the as-
           est places in the solar system, with surface temperatures                                       Eris                                  It’s one of the weirdest objects in the solar system.               teroid belt.
           hovering around minus 375 degrees Fahrenheit.                          Caltech astronomer Mike Brown led the team that dis-                Haumea measures about 1,200 miles across, making it                Scientists and the world will get a much better look
                While Pluto is tough to study because it’s so far away,       covered Eris in 2005. The find spurred the IAU to strip Pluto      nearly as wide as Pluto. But Haumea is just one-third as            at Ceres less than four years from now. In February 2015,
           scientists think the dwarf planet is about 70 percent rock         of its planethood and create the “dwarf planet” category           massive as Pluto, partly because it’s not spherical. Rather,        NASA’s Dawn spacecraft - which is currently orbiting Vesta,
           and 30 percent ice. Its surface is covered predominantly           a year later. Eris is virtually the same size as Pluto, but it’s   Haumea is shaped like a giant American football.                    the asteroid belt’s second-largest resident - will arrive at
           with nitrogen ice. The dwarf planet has a thin atmosphere          about 25 percent more massive, suggesting that Eris contains            The dwarf planet also completes one full rotation in less      Ceres to undertake a detailed study of the dwarf planet.

               Saudi Arabia discovers                                                  ‘Shrew’ is oldest ‘true’ mammal; age of
               9,000 year-old                                                          placental mammals goes back 160 million years ago
               civilization                                                                WASHINGTON: A shrew-like animal that snagged               suggested it was closer to placental mammals than mar-                 “This molecular time estimate places the time of split
                                                                                       insects from ferns lining the shores of freshwater lakes       supials on the mammal family tree. The next-oldest true           between marsupials and placentals around middle Juras-
                    JEDDAH, Saudi Arabia: Saudi Arabia is excavating a                 160 million years ago, might be one of the first “true”        mammal fossil dates back about 125 million years.                 sic, around 165 million years ago,” Luo said. “Previously,
               new archeological site that will show horses were domesti-              mammals to walk the Earth, back when the dinosaurs                 “We are placing this fossil closer to the placental line      the oldest record[ed placental fossil] was 125 million
               cated 9,000 years ago in the Arabian Peninsula, the country’s           roamed, a new fossil suggests in a report in LiveScience.      than the marsupial line, though it is definitely still be-        years ago, so there was a substantial gap between the fos-
               antiquities expert said Wednesday.                                          The new fossil, discovered in what is now Liaoning         tween the two groups,” Luo said. “It’s related and part           sil record and the molecular estimates.”
                    The discovery of the civilization, named Al-Maqar after            Province in China, is the oldest evidence of the diver-        of our ancestry, but it may not be the direct grandmother              By pushing back the placental-marsupial division by
               the site’s location, will challenge the theory that the domesti-        gence of these “true” or placental mammals from their          to our lineage.”                                                  35 million years, this fossil shows that even during the
               cation of animals took place 5,500 years ago in Central Asia,           marsupial counterparts, and indicates the mammalian                The date this fossil sets for the divergence of placen-       age of feathered dinosaurs mammals were expanding
               said Ali Al-Ghabban, Vice-President of Antiquities and Muse-            lineage was evolving faster than expected during the Ju-       tals and marsupials, 160 million years ago, agrees well           and evolving into new groups quicker than previously
               ums at the Saudi Commission for Tourism & Antiquities.                  rassic Period.                                                 with dates garnered from previous genomic analyses.               believed.
                    “This discovery will change our knowledge concerning                   “We can really conclude that the age of placental
               the domestication of horses and the evolution of culture in             mammals goes back to over 160 million years ago,”
               the late Neolithic period,” Ghabban told a news conference              study researcher Zhe-Xi Luo, of the Carnegie Museum
               in the Red Sea port of Jeddah.                                          of Natural History in Pittsburgh, told LiveScience. “It’s
                    “The Maqar Civilization is a very advanced civilization            an evolutionary milestone for mammal evolution.”
               of the Neolithic period. This site shows us clearly, the roots of           True mammals - those that have taken over much
               the domestication of horses 9,000 years ago.”                           of the world and make up 90 percent of today’s mam-
                    The site also includes remains of mummified skeletons,             mals - are different from marsupials in several ways. Most
               arrowheads, scrapers, grain grinders, tools for spinning and            importantly, marsupials give birth to very immature ba-
               weaving, and other tools that are evidence of a civilization            bies, which then climb into a pouch on the mother’s belly
               that is skilled in handicrafts.                                         where they feed and grow. Placental mammals stay in the
                    Saudi Arabia, the world’s largest oil exporter, is trying to       womb for this time, until fully developed.
               diversify its economy away from oil and hopes to increase                   The new fossil species, now called Juramaia sinensis,
                                                                                                                                                                                                                                                                 FILE-The earliest-
               its tourism.                                                            included an incomplete skull, partial skeleton and im-
                                                                                                                                                                                                                                                                 known eutherian
                    Last year the SCTA launched exhibitions in Barcelona’s             pressions of soft tissue, such as hair.
                                                                                                                                                                                                                                                                 mammal hunting
               CaixaForum museum and Paris’s Louvre museum showcas-                        Even though the soft tissue that would show marsupi-
                                                                                                                                                                                                                                                                 on a tree fern.
               ing historic findings of the Arabian Peninsula. -Reuters                al or placental traits - mammary glands or a pouch - had
                                                                                       not been retained the fossil’s forepaw bones and teeth

Higgs boson may be a mirage, scientists hint Injecting mosquitoes
                                             with bacteria can stop dengue fever
               GENEVA: Scientists chasing a particle they believe
           may have played a vital role in creation of the universe
           indicated that they were coming to accept it might not
                                                                              Under what is known as the Standard Model of
                                                                         physics, the boson, which was named after British physi-
                                                                         cist Peter Higgs, is posited as having been the agent that
           exist after all. But they stressed that if the so-called      gave mass and energy to matter just after the Big Bang            LONDON: Injecting bacteria into mosquitoes can block them          eration.” O’Neill said there were two theories to explain why the
           Higgs boson turns out to have been a mirage, the way          13.7 billion years ago. As a result, flying debris from       from transmitting the dengue virus and help control the spread of      Wolbachia was able to block the uptake of dengue. One was that
           would be open for advances into territory dubbed “new         that primeval explosion could come together as stars,         a disease that kills 20,000 people a year in more than 100 coun-       the Wolbachia boosts the mosquito’s immune system and protects
           physics” to try to answer one of the great mysteries          planets and galaxies. In the subterranean LHC, which          tries, scientists have said, in a report in The Guardian. In two pa-   it from viruses such as dengue. The second was that the Wolbachia
           of the cosmos. The CERN research center, who’s giant          began operating at the end of March 2010, CERN engi-          pers published in the journal Nature on Thursday, researchers in       competes with dengue for food inside the mosquito, making it
           Large Hadron Collider (LHC) has been the focus of the         neers and physicists have created billions of miniature       Australia showed how female mosquitoes infected with the Wol-          harder for the dengue virus to replicate.
           search, said it had reported to a conference in Mumbai        versions of the Big Bang by smashing particles together       bachia bacteria passed the bug easily to their offspring, making            More than 50 million people in more than 100 countries fall
           that possible signs of the Higgs noted last month were        at just a fraction under the speed of light.                  them all dengue-free. They said such infected mosquitoes should        sick and 20,000 die each year from dengue fever. There is no vac-
           now seen as less significant.                                      The results of those collisions are monitored by         be released into the wild, so that the spread of dengue to people      cine or specific treatment for the disease.
               A number of scientists from the center went on            hundreds of physicists not just at CERN but in linked         may be reduced.                                                             The only method of prevention is to control mosquito popu-
           to make comments that raised the possibility that the         laboratories around the world which sift through the              “The main feature we saw was their ability to reduce den-          lations through eliminating breeding sites and using insecticides.
           mystery particle might not exist.                             vast volumes of information generated by the LHC.             gue transmission,” said Professor Scott O’Neill, lead author and       O’Neill’s team released nearly 299,000 infected mosquitoes in
               “Whatever the final verdict on Higgs, we are now               Scientists at the US Fermilab near Chicago have          science faculty dean at Monash University. “It almost completely       January at more than 370 sites in north-eastern Australia, and the
           living in very exciting times for all involved in the quest   been in a parallel search in their Tevatron collider for      abolished dengue virus in the body of the mosquito.”                   bacteria spread into the wild mosquito population successfully,
           for new physics,” Guido Tonelli, from one of the two          nearly 30 years. Last month they said they hoped to               In their experiment, O’Neill and his colleagues injected the       with their offspring also infected over a three-month period.
           LHC detectors chasing the Higgs, said as the new ob-          establish if the Higgs exists by the end of September,        bacteria into more than 2,500 embryos of Aedes aegypti mosqui-              The team is seeking approval to release such infected mos-
           servations were announced.                                    when the Tevatron closes down.                                toes that can spread dengue fever. After they hatched, they were       quitoes into dengue-endemic sites in Vietnam, Thailand, Indonesia
               CERN’s statement said new results, which updated               For some scientists, the Higgs remains the simplest      treated to blood meals laced with the dengue virus, and none           and Brazil to see if it reduces rates of dengue transmission in peo-
           findings that caused excitement at another scientific         explanation of how matter got mass. It remains unclear        picked up the virus.                                                   ple. “It is an alternative strategy for dengue control which could
           gathering in Grenoble last month, “show that the elu-         what could replace it as an explanation. “We know                 “The [Wolbachia] bacteria doesn’t spread environmentally.          be low-cost and sustainable and suitable for deployment in large
           sive Higgs particle, if it exists, is running out of places   something is missing, we simply don’t quite know what         It gets passed on from mother to children through the eggs,”           urban cities in the developing world,” O’Neill said.
           to hide.”                                                     this new something might be,” wrote CERN blogger              O’Neill told Reuters. “When an infected male mates with an un-              But he added: “With any control [measure] over time, we
               The centre’s research director Sergio Bertolucci          Pauline Gagnon.                                               infected female, all her eggs die. That gives an indirect benefit to   might expect them to become less effective, like insecticides.
           told the conference, at the Indian city’s Tata Institute of        “There are many models out there; we simply need         the females with Wolbachia because when they mate with infected             “We don’t know how long that might take to occur. If it pro-
           Fundamental Research, that if the Higgs did not exist         to be nudged in the right direction,” added Gagnon, an        males, their eggs hatch normally ... all their eggs haveWolbachia in   vides effective control for 20-30 years, that is still a very good step
           “its absence will point the way to new physics.”              experimental physicist. -Reuters                              them so Wolbachia gets more and more common with every gen-            forward for dengue control.”

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