Science Special News

Collapse
This is a sticky topic.
X
X
 
  • Time
  • Show
Clear All
new posts
  • Rasputin
    Senior Member
    • Jan 2005
    • 63906

    #1351
    The DNA so dangerous it does not exist

    Submitted by Marvy: Could there be forbidden sequences in the genome - ones so harmful that they are not compatible with life? One group of researchers thinks so. Unlike most genome sequencing projects which set out to search for genes that are conserved within and between species, their goal is to identify "primes": DNA sequences and chains of amino acids so dangerous to life that they do not exist."It's like looking for a needle that's not actually in the haystack," says Greg Hampikian, professor of genetics at Boise State University in Idaho, who is leading the project. "There must be some DNA or protein sequences that are not compatible with life, perhaps because they bind some essential cellular component, for example, and have therefore been selected out of circulation. There may also be some that are lethal in some species, but not others. We're looking for those sequences."

    To do this, Hampikian and his colleage Tim Anderson, also at Boise, have developed software that calculates all the possible sequences of nucleotides - the "letters" of DNA - up to a certain length, and then scans sequence databases such as the US National Institutes of Health's Genbank to identify the smallest sequences that aren't present. Those that don't occur in one species but do in others are termed "nullomers", while those that aren't found in any species are termed primes.

    iran

    Comment

    • Rasputin
      Senior Member
      • Jan 2005
      • 63906

      #1352
      Black hole found in ancient lair

      A black hole has been found inside a compact group of ancient stars known as a globular cluster. Astronomers say the discovery is interesting because many doubted black holes could exist in such locations. Some computer simulations had suggested a newly formed black hole would simply be ejected from the cluster as a result of gravitational interactions. Tom Maccarone, of the University of Southampton (UK), and colleagues report the finding in the journal Nature. It was made using the European Space Agency's XMM-Newton satellite, with follow-up observations on the US space agency's Chandra Space Telescope - both are sensitive to the X-ray light that is emitted when gas consumed by a black hole is torn apart. The international team says its work provides the first convincing evidence that some black holes might not only survive but grow and flourish in globular clusters. What has astonished the scientists is how quickly the black hole was found. "We were preparing for a long, systematic search of thousands of globular clusters with the hope of finding just one black hole," said Dr Maccarone. "But bingo, we found one as soon as we started the search. It was only the second globular cluster we looked at."

      The black hole is located in a globular cluster associated with a galaxy named NGC 4472, some 55 million light-years away. Globular clusters are among the oldest structures in the Universe. They contain thousands to millions of stars packed into a region of space just a few tens of light-years across. These high densities should lead to frequent interactions and even collisions; and some models have suggested that large black holes - several hundred times the mass of our Sun - could develop in the densest inner regions of clusters.

      iran

      Comment

      • Rasputin
        Senior Member
        • Jan 2005
        • 63906

        #1353
        "UFO crash" reported in South Africa

        Submitted by Telemachos: A UFO was sighted at Lephalale, where it was described as a strange object "on an orange cloud, singing like a million turbines" - hitting the earth with a bang at 04:33 on Saturday. That's according to Leonie Ras, the administrative manager of Lephalale (Ellisras) who witnessed the spectacle at her daughter's farm just east of the town on Saturday morning. "I was lying on my bed reading SMS-messages when I heard a noise like an Airbus aircraft firing up its motors." "It was raining but there was no thunder or lightning. The noise grew louder and eventually it sounded like a million turbines screaming in unison," Ras said. She walked to the bedroom window and saw the clouds taking on a bright orange-red colour. "Suddenly, a bright object plunged from the clouds to the earth, at a terrible speed, and hit the ground with an almighty bang." "It looked like Haley's comet, round in the front and with an orange-red tail following behind." When the UFO hit the ground the low-lying clouds went orange.

        "It was so exceptional that I started crying. I wished my children and grandchildren could have seen it. I had not been drinking and I was in full control of my faculties," she said. She calculated that the object must have hit the ground near Beauty, between the Tambotie and Palele rivers. Cobus Nel, her son-in-law, who was also in the house, woke up from the commotion. "I woke up to a terrible rumbling, followed by a sound like an explosion. I woke my wife up, so that she could also listen, because the rumbling lasted more than a minute, becoming louder, then we heard the bang," Nel said. Lephlale's fire service, police and disaster control centres seemed to have slept through the commotion.

        iran

        Comment

        • Rasputin
          Senior Member
          • Jan 2005
          • 63906

          #1354
          Human brain evolution slows to a crawl

          The human brain underwent explosive growth after we split from our chimp cousins, but the pace of evolutionary change among the thousands of genes expressed in brain tissue has since slowed, says a new study in PLOS Biology. The researchers involved speculate that the higher complexity of the biochemical network in the brain places strong constraints on the ability of most brain-related genes to change. "We found that genes expressed in the human brain have in fact slowed down in their evolution, contrary to some earlier reports," says study author Chung-I Wu, at the University of Chicago. "The more complex the brain, it seems, the more difficult it becomes for brain genes to change. Calibrated against the genomic average, brain-expressed genes in humans appear to have evolved more slowly than in chimpanzees." To gauge the speed with which both humans and chimpanzees accumulated small differences in gene sequences, Wu and co-researchers in Asia decided to sequence several thousand genes expressed in the brain of the macaque monkey and compare them with available genomic sequences from human, chimpanzee, and mice. What they found was that the "more advanced" species had faster overall rates of evolution.

          On average, the genes from humans and chimpanzees changed faster than genes from monkeys, which changed faster than those from mice. They explained the trend as a correlate of smaller population size in the more advanced species. Species with smaller population size can more easily escape the harsh scrutiny of natural selection. When they compared the pace of evolution among genes expressed in the brain, however, the order was reversed. When calibrated against the genomic average, brain genes in humans evolved more slowly than in other primates, which were slower than mice.

          iran

          Comment

          • Rasputin
            Senior Member
            • Jan 2005
            • 63906

            #1355
            Lost lakes of Titan are found at last

            Lakes of methane have been spotted on Saturn's largest moon, Titan, boosting the theory that this strange, distant world bears beguiling similarities to Earth, according to a new study. Titan has long intrigued space scientists, as it is the only moon in the Solar System to have a dense atmosphere -- and its atmosphere, like Earth's, mainly comprises nitrogen. Titan's atmosphere is also rich in methane, although the source for this vast store of hydrocarbons is unclear. Methane, on the geological scale, has a relatively limited life. A molecule of the compound lasts several tens of millions of years before it is broken up by sunlight. Given that Titan is billions of years old, the question is how this atmospheric methane gets to be renewed. Without replenishment, it should have disappeared long ago. A popular hypothesis is that it comes from a vast ocean of hydrocarbons. But when the US spacecraft Cassini sent down a European lander, Huygens, to Titan in 2005, the images sent back were of a rugged landscape veiled in an orange haze.

            There were indeed signs of methane flows and methane precipitation, but nothing at all that pointed to any sea of the stuff. But a flyby by Cassini on July 22 last year has revealed, thanks to a radar scan, 75 large, smooth, dark patches between three and 70 kilometers across (two and 42 miles) across that appear to be lakes of liquid methane, scientists report on Thursday. They believe the lakes prove that Titan has a "methane cycle" -- a system that is like the water cycle on Earth, in which the liquid evaporates, cools and condenses and then falls as rain, replenishing the surface liquid.

            iran

            Comment

            • Rasputin
              Senior Member
              • Jan 2005
              • 63906

              #1356
              Calf with two faces born at Va. farm

              One of the newest arrivals at ***k Heldreth's dairy farm is drawing crowds. A calf with two faces was born Dec. 27 at Heldreth Dairy Farm, and word has spread in southwest Virginia as residents flock to his farm. The animal is normal from its tail until its unusually large head. The calf breathes out of two noses and has two tongues, which move independently, according to Heldreth. There appears to be a single socket containing two eyes where the heads split."It's the craziest thing I've ever seen," the dairyman said.During the calf's birth, Heldreth said he first thought there were two calves.The calf has two lower jaws, but only one mouth. Heldreth feeds her through a tube, and acknowledges he probably can't maintain that feeding schedule for long.The calf was the product of artificial insemination, which was supposed to create a genetically superior specimen. "Genetically, this is one of my better calves," he said.Bob James, a professor in the dairy science department at Virginia Tech and Heldreth's former teacher, said such births are unusual."In my 25 years, I've seen it maybe two or three times, but it's pretty rare," he said.

              James said the abnormality could be caused by a developmental problem or a genetic quirk.According to MedicineNet.com, the condition is called diprosopus. It happens when twins start to form and don't completely separate. In most cases, the twins are completely fused with one set of limbs, but part or all the face is duplicated.Heldreth said the calf doesn't appear to have any other physical ailments or complications."It's as healthy as can be," he said.Heldreth expects many more people will be curious enough to stop by.

              iran

              Comment

              • Rasputin
                Senior Member
                • Jan 2005
                • 63906

                #1357
                The mysterious history of tattoos

                Humans have marked their bodies with tattoos for thousands of years. These permanent designs—sometimes plain, sometimes elaborate, always personal—have served as amulets, status symbols, declarations of love, signs of religious beliefs, adornments and even forms of punishment. Joann Fletcher, research fellow in the department of archaeology at the University of York in Britain, describes the history of tattoos and their cultural significance to people around the world, from the famous " Iceman," a 5,200-year-old frozen mummy, to today’s Maori.In terms of tattoos on actual bodies, the earliest known examples were for a long time Egyptian and were present on several female mummies dated to c. 2000 B.C. But following the more recent discovery of the Iceman from the area of the Italian-Austrian border in 1991 and his tattoo patterns, this date has been pushed back a further thousand years when he was carbon-dated at around 5,200 years old.

                There's certainly evidence that women had tattoos on their bodies and limbs from figurines c. 4000-3500 B.C. to occasional female figures represented in tomb scenes c. 1200 B.C. and in figurine form c. 1300 B.C., all with tattoos on their thighs. Also small bronze implements identified as tattooing tools were discovered at the town site of Gurob in northern Egypt and dated to c. 1450 B.C. And then, of course, there are the mummies with tattoos, from the three women already mentioned and dated to c. 2000 B.C. to several later examples of female mummies with these forms of permanent marks found in Greco-Roman burials at Akhmim.

                iran

                Comment

                • Rasputin
                  Senior Member
                  • Jan 2005
                  • 63906

                  #1358
                  Meteorite shoots through house roof

                  Submitted by Irishdish: The mysterious object that shot through the roof of a two-story home earlier this week was identified by scientists as a meteorite, police said Friday. But the fate of the extraterrestrial mass, likely formed with the solar system some 4.6 billion years ago, has emerged as another unknown in the case of the second known meteorite to fall in New Jersey.Its new owners, a married couple with a son, expressed some interest in putting the meteorite on a small-scale tour so local schoolchildren could see it, said Jeremy Delaney, a Rutgers University meteoriticist who was among four scientists who identified the object for police and later met the family.Eventually the family will have to decide whether to keep the meteorite, give it to an academic institution such as a museum or sell it to a collector.What's for sure is that the object will be in high demand.Rarely on landings do meteorites come in contact with people. So when they do, the space artifacts are connected with a story that generates interest all around.The American Museum of Natural History in New York City and the Smithsonian Institution in Washington D.C., both of which have extensive meteorite collections, likely will have interest, Delaney said.Depending on the rarity of a given meteorite, researchers sometimes spend several years looking at the same chunk that fell from space."By looking at these objects, we have the ability to explore our deep, deep past," Delaney said.

                  "Meteorites have given scientists clues about life on Mars and the rest of our solar system."New Jersey's only other known meteorite, weighing an ounce, fell in Deal in 1829.The precise research value of New Jersey's newest meteorite won't be known unless it ends up in the hands of scientists who would study its composition.But Delaney said the Freehold meteorite might be of some interest to researchers because it is rich in metals, a sign that it came from the deep interior of an asteroid."We all want to know where it's from and you won't get that until you do some analysis," said Peter Elliott, a Colts Neck metallurgist who also helped identify the meteorite.

                  iran

                  Comment

                  • Rasputin
                    Senior Member
                    • Jan 2005
                    • 63906

                    #1359
                    Huge object sighted over Cambridge

                    Sam Willey: I have recently been in touch with a very credible UFO witness who at 11pm on December 24th 2006 in Wisbech, Cambridgeshire UK was taking her dog for a walk as she looked above a house she noticed a massive circular shaped object in the sky. She said that the craft was high up in the air and 100 yards across swirling slowly in a counter clockwise motion. The witness added that the craft had “jagged edges” and had dashes of bright light around it. The object was witnessed completely stationary for around 30 minutes after this time it then began to move up the street. The witness rushed inside and told her husband what she had witnessed her husband then proceeded to also view the craft. As the object moved up the street the witness told me that she felt extremely frightened by what she was seeing. On the phone she said “it was the strangest thing I have ever seen” she also stated that she has never really took much notice of reports of unknown craft in the skies but now has a different view. The craft stayed in view for around 3 hours during this time the craft slowly moved up the street and eventually right over the witnesses home the craft then proceeded off into the distance. I personally spoke with this witness on the phone on December 29th 2006 five days after the event and I can confirm that she is a credible witness who sounded extremely genuine and I consider this report of the highest credibility.

                    This key witness has informed me that she knows that other people saw this object including her friend who she spoke to after the incident her friend is located 2 miles away from her and was also able to see the object with this in mind it is logical to assume that this craft must have been huge. The witness has got in contact with a local newspaper who will be featuring an article sometime in the near future this case has also been reported on by a local radio station. I spoke again with the eyewitness on January 5th 2007 she told me that she also got in contact with the BBC news about the incident but the BBC have not yet covered the mysterious event in any form. The local radio station mentioned above said they believe the object could be explained by lasers however the witness has told me it was not any kind of laser she also states that she does not believe this was a secret government test. I will be keeping in touch with the witness and will post the latest updates.If you saw anything unusual on December 24th 2006 in the Cambridge area I urge you to come forward you can contact me anytime using the following email address - sam@alienationsam.com <mailto:sam@alienationsam.com> if you would prefer to speak to me directly then please send me your telephone number and I will get back to you as quickly as possible.

                    iran

                    Comment

                    • Rasputin
                      Senior Member
                      • Jan 2005
                      • 63906

                      #1360
                      Untangling the mystery of the Inca

                      Incan civilization was a technological marvel. When the Spanish conquistadors arrived in 1532, they found an empire that spanned nearly 3,000 miles, from present-day Ecuador to Chile, all served by a high-altitude road system that included 200-foot suspension bridges built of woven reeds. It was the Inca who constructed Machu Picchu, a cloud city terraced into a precarious stretch of earth hanging between two Andean peaks. They even put together a kind of Bronze Age Internet, a system of messenger posts along the major roads. In one day, Incan runners amped on coca leaves could relay news some 150 miles down the network.Yet, if centuries of scholarship are to be believed, the Inca, whose rule began 2,000 years after Homer, never figured out how to write. It's an enigma known as the Inca paradox, and for nearly 500 years it has stood as one of the great historical puzzles of the Americas. But now a Harvard anthropologist named Gary Urton may be close to untangling the mystery.His quest revolves around strange, once-colorful bundles of knotted strings called khipu (pronounced KEY-poo). The Spanish invaders noticed the khipu soon after arriving but never understood their significance – or how they worked.Once, at the beginning of the 17th century, a group of Spaniards traveling in the central Peruvian highlands east of modern-day Lima encountered an old Indian carrying khipu that he insisted held a record of "all [the Spanish] had done, both the good and the bad."

                      Angered, the Spanish burned the man's khipu, as they did countless others over the years.Some of the knots did survive, though, and for centuries people wondered if the old man had been speaking the truth. Then, in 1923, an anthropologist named Leland Locke provided an answer: The khipu were files. Each knot represented a different number, arranged in a decimal system, and each bundle likely held census data or summarized the contents of storehouses. Roughly a third of the existing khipu don't follow the rules Locke identified, but he speculated that these "anomalous" khipu served some ceremonial or other function. The mystery was considered more or less solved.

                      iran

                      Comment

                      • Rasputin
                        Senior Member
                        • Jan 2005
                        • 63906

                        #1361
                        Report suggests Mars microbes overlooked

                        Two NASA space probes that visited Mars 30 years ago may have stumbled upon alien microbes on the Red Planet and inadvertently killed them, a scientist theorizes in a paper released Sunday. This new report, based on a more expansive view of where life can take root, may have NASA looking for a different type of Martian life form when its next Mars spacecraft is launched later this year, one of the space agency‘s top scientists told The Associated Press. In the ‘70s, the Viking mission found no signs of life. But it was looking for Earth-like life, in which salt water is the internal liquid of living cells. Given the cold dry conditions of Mars, that life could have evolved on Mars with the key internal fluid consisting of a mix of water and hydrogen peroxide, said Dirk Schulze-Makuch, author of the new research. The Viking experiments of the ‘70s wouldn‘t have noticed alien hydrogen peroxide-based life and, in fact, would have killed it by drowning and overheating the microbes, said Schulze-Makuch, a geology professor at Washington State University. "The problem was that they didn‘t have any clue about the environment on Mars at that time," Schulze-Makuch said. "This kind of adaptation makes sense from a biochemical viewpoint." Schulze-Makuch acknowledges he can‘t prove that Martian microbes exist, but given the Martian environment and how evolution works, "it makes sense."

                        Schulze-Makuch‘s research coincides with work being completed by a National Research Council panel nicknamed the "weird life" committee. The group worries that scientists may be too Earth-centric when looking for extraterrestrial life. The problem for scientists is that "you only find what you‘re looking for," said Penn State University geosciences professor Katherine Freeman, a reviewer of the NRC work. "Logical consistency is nice, but it‘s not enough anymore," McKay said.

                        iran

                        Comment

                        • Rasputin
                          Senior Member
                          • Jan 2005
                          • 63906

                          #1362
                          See the future by concentrating on the past

                          The ability to "see" oneself in the future is a remarkable human trait — some would say unique — that is not well understood. That's despite the fact that we probably spend as much time thinking about the future as we do thinking about the present. Now new research from Washington University in St. Louis suggests that it's precisely because we can remember the past that we can visualize the future. "Our findings provide compelling support for the idea that memory and future thought are highly interrelated and help explain why future thought may be impossible without memories," says doctoral candidate Karl Szpunar, lead author of a report on the research in the Jan. 1 issue of the Proceedings of the National Academy of Sciences.The findings are consistent with other research showing that persons with little memory of the past, such as young children or individuals suffering from amnesia, are less able to see themselves in the future."Specifically, individuals, be they depressive patients, young children, or amnesiacs, who are unable to vividly recollect their past also seem to be unable to form specific mental images of the future," the researchers say in their report.

                          "If you have an amnesic person who can't remember the past, they're also not at all good about thinking about what they might be doing tomorrow or envisioning any kind of personal future," adds Kathleen McDermott, principal investigator for the university's memory and cognition lab and a co-author of the report.

                          iran

                          Comment

                          • Rasputin
                            Senior Member
                            • Jan 2005
                            • 63906

                            #1363
                            Hubble makes 3D dark matter map

                            Astronomers have mapped the cosmic "scaffold" of dark matter upon which stars and galaxies are assembled. Dark matter does not reflect or emit detectable light, yet it accounts for most of the mass in the Universe. The study, published in Nature journal, provides the best evidence yet that the distribution of galaxies follows the distribution of dark matter. This is because dark matter attracts "ordinary" matter through its gravitational pull. Scientists presented details of their research during a news conference here at the 209th meeting of the American Astronomical Society (AAS) in Seattle, Washington. It involved nearly 1,000 hours of observations with the Hubble Space Telescope. According to one researcher, the findings provide "beautiful confirmation" of standard theories to explain how structures in the Universe evolved over billions of years. Ordinary matter - gas, stars, planets and galaxies - makes up just one-sixth of all matter in the Universe. The remainder is unseen. While previous studies of dark matter relied on simulations, this one details its large-scale distribution in 3D. For astronomers, the challenge of mapping the Universe has been described as similar to mapping a city from night-time aerial snapshots showing only street lights.

                            Dark matter is invisible, so only the luminous galaxies can be seen directly. The new images are equivalent to seeing a city, its suburbs and country roads in daylight for the first time. Yet puzzling discrepancies remain. The map of mass distribution is based on measurements of about half a million distant galaxies. Lead author Richard Massey and his colleagues used a technique called weak gravitational lensing to detect the dark matter. To reach us, the light from galaxies has to pass through intervening dark matter.

                            iran

                            Comment

                            • Rasputin
                              Senior Member
                              • Jan 2005
                              • 63906

                              #1364
                              Image of Jesus sighted in tree

                              Some people in Florida say the image of Jesus has appeared in a tree. A woman discovered it a week before Christmas. The images appears in Daryl Brown's front yard. Brown just moved to Florida from Texas. He say’s it is giving his family comfort about their move to their new home. "It's a blessing for me just coming to town, getting introduced and meeting new people out here ... When she showed me that, I said, 'OK, there is a Jesus.'" said Brown. The likeness has created a buzz in the neighborhood and has many residents at a loss for words. "I see the face, eyes, and you can see the crown," said one neighbor. "I can't say what I feel, I just feel it," said another neighbor. The image was discovered a week before Christmas by a woman walking her dog, the report said. Overjoyed by what she saw, the woman shared the news with her neighbor.

                              Similar to other cases of similar sightings, there will be skeptics. However, Brown said no skeptic could convince him the image is anything but Jesus Christ. "Jesus don't just pop up like that. If you know the word of Jesus and you believe in Jesus, then there you go. He does exist," Brown said.

                              iran

                              Comment

                              • Rasputin
                                Senior Member
                                • Jan 2005
                                • 63906

                                #1365
                                Mystery lingers over Chicago UFO claims

                                The Federal Aviation Administration says it must have been a weird weather phenomenon, and United Airlines denies any knowledge of the case. But though it has been two months since what appeared to be an unidentified flying object (UFO) was spotted over Chicago's O'Hare International Airport, the incident is still raising questions about what exactly was seen and whether the authorities are trying to downplay it.As many as a dozen United Airlines employees swear the mysterious object they saw on Nov. 7 was real—hovering for several minutes above the United Airlines terminal and then shooting up through the clouds so powerfully that it left an eerie hole in overcast skies. "At first we laughed to each other" when the report came over the radio, a witness told the National UFO Reporting Center, a Seattle-based nonprofit that maintains a UFO hotline and is listed as a resource in the FAA's official Aeronautical Information Manual. But then I saw the "dark gray, hazy, round object" and seconds later "there was an almost perfect circle in the cloud layer where the craft had been." His statement is published on the Web site of the National UFO Reporting Center, which says its policy is to protect the anonymity of its witnesses.So was it a UFO? A secret military aircraft? And why did it take two months for the details to come out?

                                It may sound like the oldest hoax in the book, but the United workers—including several pilots—who say they saw the object are reportedly upset their claims have been ignored. The FAA has said it won't be investigating the incident further, and it wasn't until this week that The Chicago Tribune broke the story, speaking to several unnamed witnesses after a tip-off from the head of the National UFO Reporting Center. Peter Davenport heads that organization, and has a lot to say about the way the incident has been handled.

                                iran

                                Comment

                                Working...