TOP 100 SCIENCE SITES
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| Famed Tasmanian devil euthanized after tumor found By KRISTEN GELINEAU 2010-09-01T07:44:54ZSYDNEY (AP) -- A Tasmanian devil named Cedric, once thought to be immune to a contagious facial cancer threatening the iconic creatures with extinction, has been euthanized after succumbing to the disease, researchers said Wednesday.... hosted.ap.org |
Mystery bird: Hamerkop, Scopus umbretta Demsystified! I also include a list of interesting traits that this fascinating mystery bird possessesHamerkop, Scopus umbretta, also known as the hammerkop, hammerkopf, hammerhead, hammerhead stork, umbrette, umber bird, tufted umber, or anvilhead. This bird was photographed at Ngorongoro Crater, northern Tanzania.Image: Dan Logen, 23 January 2010. [larger view]. Nikon D300, 600mm lens with 1.4 extender, ISO 500, f/9, 1/400 secThis legendary and distinctive African mystery bird species is just so peculiar that instead of asking a specific question about one of its many remarkable traits, I am instead interested to know what you think is most fascinating about this species. Is it possible to choose just one trait?Here's a list what I find remarkable about the hamerkop: To a casual observer, this long-legged wading bird resembles a heron or perhaps a stork, but it is currently placed in the pelican and cormorant group, Pelecaniformes, although it is classified into Ciconiiformes (storks, herons, egrets, ibises, and spoonbills) by other authorities This species is so peculiar in so many ways that it is the only member of its taxonomic family (Scopidae) and genus (Scopus) Its middle toenail has a rough comb-like edge (a pectinate toe), as do the herons (this toe is used to groom its feathers) It soars with its neck stretched out like a stork or ibis, but during flapping flight, it coils its neck back so that it resembles a heron Convergent evolution is the reason this bird's bill looks similar those of the shoebill, Balaeniceps rex, and the boat-billed heron, Cochlearius cochlearius (neither of which appear to be closely related to the hamerkop) The hamerkop's feet are partially webbed. Is this a morphological relic from this species' evolutionary past? Hamerkop behaviour is strange, too. For example, as many as 10 individuals may join displays where they run circles around each other, all calling loudly, raising their crests and fluttering their wings. What is the evolutionary function for this behaviour? They also engage in "false mounting", where one bird stands on top of another, but they may not be mates and they do not copulate. Is this some sort of dominance behaviour? Their nests are truly astonishing objects as well. The nests are huge, often large enough for a human to sit in, and the outside is decorated with brightly coloured objects. Do these decorations serve a purpose? If so, what might that be? Not only are their nests huge, but these birds are obsessive about building lots of them, too. Even when the adults are not breeding, each pair constructs three to five nests every year – what is the evolutionary "reason" for such a large energy expenditure on building structures that the birds may never use? If you have bird images, video or mp3 files that you'd like to share with a large and appreciate audience, feel free to email them to me for consideration.GrrlScientistguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
Quarks, gluons and jets | Jon Butterworth The LHC paper I've been working on for the past few months is finally out. It shows quarks and gluons doing what they should do, and I love itIn July we (ATLAS) released a preliminary version of our first jet cross section measurement, and showed it at the International Conference on High Energy Physics (ICHEP) in Paris. Today we submitted the final version of this measurement to the European Physical Journal and to the archive."Cross section" in this context is basically a probability. If you fire two footballs at each other, they have a bigger cross-sectional area than two snooker balls, so they are more likely to hit each other. A "jet cross section" is a measure of how likely we are to see jets when we fire two protons at each other.Jets are what quarks and gluons do when they try to escape. The proton is made up of quarks stuck together by gluons. Most of the fundamental forces get weaker with distance - the Earth's gravitational pull gets weaker the further out into space you go, for example. But the strong nuclear force is the other way round.The force between two quarks actually gets stronger as you pull them apart, more like an elastic band. When two quarks in LHC protons bounce off each other they head away really quickly, feeling almost no force at first (physics buzzwords: asymptotic freedom. See this Nobel Prize citation). But at some point that has to end, because as they get further and further from the protons they were knocked out of, the force pulling them back gets stronger and stronger.You can think of the quarks as being the ends of the elastic band. They fly away from each other until at some point the band snaps and two new ends (new quarks) are produced. Eventually, we see a spray of hadrons (particles, like the proton, which contain quarks and generate amusing typos). Because the initial quarks get kicked so hard, this spray is collimated into a jet, and despite all the splitting and production of new quarks, the direction of the jet reflects pretty well the initial direction of the quark.ResultSo, what you see in the plot below reflects the distribution of quarks and gluons scattered in collisions at the LHC.When we collide protons, we really care most about the collisions between the proton's constituents - quarks or gluons. Unfortunately the quarks and gluons only carry a fraction of the energy of the proton, and we have no way of choosing how much. If the fraction was a half, for example, then we would have jets with 1750 gigaelectronvolts (GeV) of energy (half of 3.5 TeV). But most of the quarks and gluons carry much smaller fractions.To have a real measurement of this, and show that the theory prediction (quantum chromodynamics, labelled QCD on the plot) agrees with the data, is a real achievement. It directly involved dozens of people, and less directly hundreds. One key component is the energy calibration which I described here.This result, like the minimum bias results, is part of finding our feet in the new energy regime of the LHC - but these collisions are much closer to where we want to be. And we already have about 300 times more data to play with than is shown here, with more flooding in. We are already using these data to look for new forces and particles (see here and here).PSWhen we put the preliminary results out, I wrote an earlier version of this article. Unlike the data, it changed quite a bit in between! In a good way.Jon Butterworthguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
UK scientists develop urine test to detect prostate cancer risk Breakthrough could mean more accurate predictions of disease, which affects around 35,000 men in Britain each yearBritish scientists may have paved the way for a simple and reliable test to discover which men are at high risk of developing prostate cancer, it has emerged.The breakthrough could mean more accurate predictions of the disease which affects around 35,000 men in Britain each year, leading to 10,000 deaths.A urine test to detect levels of the protein MSMB could replace current blood testing for the disease after research showed the protein is present at reduced levels in men diagnosed with the disease.Levels also appear to be affected by tumour aggressiveness.Currently doctors rely on blood tests for prostate specific antigen (PSA) to assess the risk and progress of the disease.MSMB level is affected by a genetic change linked to prostate cancer.The research, published in the online journal Public Library of Science ONE, shows that the urine test has proven to be twice as precise as the current method.Study leader Dr Hayley Whitaker, from Cancer Research UK charity's Cambridge Research Institute, said: "We looked in tissue and urine from over 350 men with and without prostate cancer to find out how much MSMB they had."We then looked to see who had the genetic change. It was really exciting to find out that the genetic change and the amount of protein were linked."The protein is easy to detect because it is found in urine and would potentially be a very simple test to carry out on men to identify those most at risk of developing the disease."Dr Kate Holmes, research manager at The Prostate Cancer Charity, said: "These preliminary results show that MSMB, a protein produced by the prostate gland, is found at significantly lower levels in the urine of men diagnosed with prostate cancer than those without the disease. The study also found that men with an aggressive tumour were also likely to have lower levels of the protein in their urine."The study suggests that measuring levels of this protein could potentially be a powerful way to predict how likely a man is to develop prostate cancer."However, further research on a much larger scale is needed to determine how effective the detection of MSMB in the urine is for predicting the risk of, and potentially even diagnosing, prostate cancer."The research could led to urine testing kits, less expensive than the blood testing, at GP surgeries, with results available within hours. A trial on 1,200 men is currently underway and is expected the be completed by Christmas.Further larger-scale trials will also have to be carried out. Men found to have low levels of MSMB could then be closely monitored with the aim of detecting the disease, should it develop, as early as possible.Prostate cancerCancerMedical researchCancerHealthCaroline Daviesguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
A Conversation With Julian L. Seifter: A Nephrologist and Patient Dr. Julian L. Seifter, 61, specializes in treating patients who have chronic kidney disease. “Everyone needs the opportunity to forget their disease for a while and think of other things,” he says. feeds.nytimes.com |