Saturday, November 21, 2009

EMOTIONS INCREASE OR DECREASE PAIN

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Getting a flu shot this fall? Canadians scientists have found that focusing on a pretty image could alleviate the sting of that vaccine. According to a new Université de Montréal study, published in the latest edition of the Proceedings of the National Academy of Sciences (PNAS), negative and positive emotions have a direct impact on pain.

"Emotions – or mood – can alter how we react to pain since they're interlinked," says lead author Mathieu Roy, who completed the study as a Université de Montréal PhD student and is now a post-doctoral fellow at Columbia University. "Our tests revealed when pain is perceived by our brain and how that pain can be amplified when combined with negative emotions."

As part of the study, 13 subjects were recruited to undergo small yet painful electric shocks, which caused knee-jerk reactions controlled by the spine that could be measured. During the fMRI process, subjects were shown a succession of images that were either pleasant (i.e. summer water-skiing), unpleasant (i.e. a vicious bear) or neutral (i.e. a book). Brain reaction was simultaneously measured in participants through functional magnetic resonance imaging (fMRI).

The fMRI readings allowed the scientists to divide emotion-related brain activity from pain-related reactions. "We found that seeing unpleasant pictures elicited stronger pain in subjects getting shocks than looking at pleasant pictures," says Dr. Roy.

The discovery provides scientific evidence that pain is governed by mood and builds on Dr. Roy's previous studies that showed how pleasant music could decrease aches. "Our findings show that non-pharmaceutical interventions – mood enhancers such as photography or music – could be used in the healthcare to help alleviate pain. These interventions would be inexpensive and adaptable to several fields," he stresses.

(Photo: U. Montreal)

Université de Montréal

RAPID STAR FORMATION SPOTTED IN 'STELLAR NURSERIES' OF INFANT GALAXIES

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The Universe's infant galaxies enjoyed rapid growth spurts forming stars like our sun at a rate of up to 50 stars a year, according to scientists at Durham University.

The findings show that "stellar nurseries" within the first galaxies gave birth to stars at a much more rapid rate than previously expected, the researchers from Durham's Institute for Computational Cosmology revealed.

The research looked back 12.5 billion years to one of the most distant known galaxies, about one billion years after the Big Bang.

Using a technique called gravitational lensing – where distant galaxies are magnified using the gravity of a nearby galaxy cluster – the scientists observed the rapid bursts of star formation in the galaxy called MS1358arc.

Within the star-forming regions, new stars were being created at a rate of about 50 stars per year - around 100 times faster than had been previously thought.

The researchers, who say their work represents the most detailed study of a galaxy at such a young age, believe the observed galaxy is typical of others in the early Universe.

They say the galaxy, which measures 6,000 light years across, also has all the characteristics that would allow it to eventually evolve into a galaxy such as our Milky Way, giving an insight into how our sun and galaxy formed.

The Durham researchers based their findings on observations from the Gemini North telescope, based in Hawaii, and NASA's Hubble and Spitzer Space Telescopes. The research appears in the Monthly Notices of the Royal Astronomical Society. The research was funded by the Royal Astronomical Society.

Lead author Dr Mark Swinbank, in the Institute for Computational Cosmology, at Durham University, said: "The runaway effect in this galaxy suggests it is growing much faster than expected.

"Given the size of the star forming regions, we would expect it to be forming stars at the rate of about one sun per year, but it seems to be much more active than that.

"We think this galaxy is fairly typical of galaxies at this time and we expect that the Milky Way once looked like this as it formed its first stars.

"In effect we are seeing the first generation of stars being born in a galaxy like the Milky Way. This gives unique insight into the birth of our own galaxy."

The researchers say most of the observed stars eventually exploded as supernovae, spewing debris back into space where it formed into new stars

Dr Swinbank added: "In this respect these stars are the seeds of future star formation in the Universe."

Royal Astronomical Society President Professor Andy Fabian said: "It is exciting to see such a detailed picture of a very distant galaxy.

"This pioneering work shows what our own galaxy might have looked like when it was a tenth of its present age."

(Photo: Dr Johan Richard, Durham University)

Durham University

WELL-TRAVELED WASPS PROVIDE HOPE FOR VANISHING SPECIES

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They may only be 1.5mm in size, but the tiny wasps that pollinate fig trees can travel over 160km in less than 48 hours, according to research from scientists at the University of Leeds. The fig wasps are transporting pollen ten times further than previously recorded for any insect.

The fig wasps travel these distances in search of trees to lay their eggs, which offers hope that trees pollinated by similar creatures have a good chance of surviving if they become isolated through deforestation.

"Fig trees provide very important food for vertebrates," explains Dr Stephen Compton of the University's Faculty of Biological Sciences. "More birds and animals feed on fig trees than on any other plant in the rainforest. Our research shows that trees pollinated by this type of insect should be very resistant to forest fragmentation."

"Fig wasps are weak flyers," added Dr Compton. "They fly up in an air column and are then carried by wind until they sense host figs at which point they drop close to the ground and hunt out the scent of the tree which is specific to them.

"As adult wasps live for just 48 hours, they must have travelled these distances incredibly fast. It took our field scientists and volunteers nearly two weeks to walk 250km and map the fig trees used in the research."

Using a unique mix of field work and genetic tests, the researchers tracked the movement of pollen between trees and used this as the marker for insect movement.

The scientists mapped all the African fig trees (Ficus sycomorus) along 250km of the Ugab River valley in the Namib Desert. Due to the climate, the trees were only able to survive near the river, which made it possible to identify each of the 79 trees in the area individually.

The trees were DNA tested and seedlings grown from their fruit. Genetic tests on the seedlings enabled the researchers to identify which trees had cross-pollinated. As the trees are only pollinated by the fig wasp Ceratosolen arabicus, the scientists were able to map the distances travelled by the insects.

"This is the first research to identify each individual tree, rather than extrapolate the genetic mix from a sample," said Professor Philip Gilmartin, formerly from Leeds and now at the University of Durham. "We were basically paternity testing trees: we knew which tree was the 'mother' and because we already had the DNA results for the other trees, it was easy to identify the 'father'. It meant we were tracking the route of an individual grain of pollen."

The shortest distance recorded for cross-pollination was 14km and the furthest 164km. Trees were not necessarily pollinated by their nearest neighbour, and some pollen came from unidentified trees, indicating that some insects were travelling even longer distances than those recorded.

(Photo: U. Leeds)

University of Leeds

DOES GREEN TEA PREVENT CANCER?

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Although scientists are reluctant to officially endorse green tea as a cancer prevention method, evidence continues to grow about its protective effects, including results of a new study published in Cancer Prevention Research, a journal of the American Association for Cancer Research, which suggests some reduction in oral cancer.

Vassiliki Papadimitrakopoulo, M.D., professor of medicine in the Department of Thoracic/Head and Neck Medical Oncology at the University of Texas M. D. Anderson Cancer Center, and colleagues tested green tea extract taken orally for three months at three doses among 41 patients: 500 mg/m2, 750 mg/m2 or 1,000 mg/m2.

The researchers assessed clinical response in oral pre-malignant lesions and found 58.8 percent of patients at the highest doses displayed clinical response, compared with 18.2 percent among those taking placebo. They also observed a trend toward improved histology, and a trend towards improvement in a handful of biomarkers that may be important in predicting cancer development.

Patients were followed for 27.5 months and at the end of the study period, 15 developed oral cancer. Although there was no difference in oral cancer development overall between those who took green tea and those who did not, patients who presented with mild to moderate dysplasia had a longer time to develop oral cancer if they took green tea extract.

Although encouraged by the results, Papadimitrakopoulo cautioned against any recommendations that green tea could definitely prevent cancer.

"This is a phase II study with a very limited number of patients who took what would be the equivalent of drinking eight to 10 cups of green tea every single day," said Papadimitrakopoulo. "We cannot with certainty claim prevention benefits from a trial this size."

Dong Shin, M.D., professor of hematology and medical oncology and Blomeyer Endowed Chair in Cancer Research at Emory School of Medicine, agreed, but said this trial is certainly a step in the right direction.

"A clinical trial with a natural compound is no easy task, and these researchers have accomplished that," said Shin, an editorial board member of Cancer Prevention Research. "The lack of toxicity is also important because often when you give supplements at higher doses than what would occur naturally, you induce nausea and vomiting. That did not happen in this trial."

Neither researchers had a reason why patients concerned about cancer should not drink green tea, but they cautioned against relying on the beverage to definitively reduce their risk of cancer.

"The goal of this kind of research is to determine whether or not these supplements have long-term prevention effects. More research including studies in which individuals at high risk are exposed to these supplements for longer time period is still needed to answer that sort of question," said Papadimitrakopoulo.

(Photo: Dong Shin, M.D)

The American Association for Cancer Research

THE HUMBLE BEGINNINGS OF A KING

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Tyrannosaurus rex and related large carnivorous dinosaurs together form the family Tyrannosauridae. A long forgotten fossil skull in the collections of the Natural History Museum in London has now provided crucial clues to the early stages of the lengthy evolutionary history of these fearsome predators.

Almost a century after its discovery, the specimen, named Proceratosaurus, has now been recognized as the oldest known relative of the Tyrannosauridae. With the help of an ultramodern imaging technique, a team of researchers led by Dr. Oliver Rauhut from LMU Munich and Dr. Angela Milner from the Natural History Museum London, have been able to show that Proceratosaurus resembled its approximately 100-million-years younger descendant T. rex in a number of ways. The teeth, the jaws, and the structure of the cranial cavity of the two species have many features in common. Proceratosaurus weighed only about 40 kg, says Rauhut. Nevertheless, like the later tyrannosauroids, the animal obviously depended on its powerful biting apparatus. Later modifications of the jaw muscles and the overall structure of the cranium then gave rise to the perfect hunting weapon wielded by T. rex.

Among the dinosaur specimen housed in the collections of the Natural History Museum in London is an almost complete skull that was found in the West of England about 100 years ago. The fossil was initially misclassified, but was later recognized as representing an otherwise unknown genus, which was named Proceratosaurus. The skull has only recently been subject to detailed study by a team led by the palaeontologist Dr. Oliver Rauhut, who holds dual appointments in the Department of Geological and Environmental Sciences at Ludwig-Maximilians-Universität (LMU) in Munich and the Bavarian State Collection for Paleontology and Geology, and Dr Angela Milner, Associate Keeper of Palaeontology at the Natural History Museum in London.

This skull, which had been overlooked for so long, turns out to be a spectacular find. Proceratosaurus is the earliest known ancestor of the family Tyrannosauridae (named after its most famous representative Tyrannosaurus rex). Proceratosaurus and T. rex were both bipedal carnivores and each had a massive body, short and stubby forelimbs, a powerful tail, and sharp teeth set in a bulky skull. The best known members of the family, T. rex, lived during the late cretaceous period, although smaller species are known from the earlier Jurassic era.

Little is known about the origins and later evolution of this important group of dinosaurs. Proceratosaurus could now cast much needed light on the process. "It is quite astonishing that this fossil has received so little attention, since it is one of the best preserved dinosaur skulls in Europe", reports Rauhut. Parts of the skull that were still embedded in the rock matrix and these had to be exposed carefully by preparator Scott Moore-Fay at the Natural History Museum in London; the team also used an advanced imaging technique to probe the detailed structure of the fossil.

"Computerized tomography is a wonderful method, because it offers us a non-destructive means of visualizing the internal structures of fossils", says Angela Milner, the researcher responsible for the specimen at the Natural History Museum, who personally took the fossil to Texas, where the tomographic scan was performed. Detailed studies of the resulting images and of the skull itself were subsequently carried out back in London.

The investigations uncovered a wide range of features in the cranial cavity, teeth and jaws that Proceratosaurus shares with the huge T. rex, despite the fact that the Proceratosaurus skull is about 100 million years older and much smaller. The Proceratosaurus cranium was about five times less massive than that of its mighty relative, and the intact animal appears to have weighed only about 40 kg. Mature specimens of Tyrannosaurus, in contrast, weighed in at up to eight tons.

Because the Proceratosaurus skull already displays characteristics that are typical of its later descendants, the powerful jaw with its slicing teeth was probably the animal's most important weapon. "It is likely that this hunting strategy developed first", says Rauhut. The basic tool kit was perfected in later tyrannosaurids: The skull became more robust and the jaw muscles larger and, overall, the body increased enormously in size. Proceratosaurus also confirms that the tyrannosauridae developed over a very long stretch of time, and gave rise to a great diversity of forms. Further members of the family surely await discovery."

Ludwig-Maximilians-Universität

SCIENTISTS PRODUCE FIRST DRAFT OF PIG GENOME

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A global collaboration, supported in the UK in part by BBSRC, has produced a first draft of the genome of a domesticated pig, an achievement that will lead to insights in agriculture, medicine, conservation and evolution.

A red-haired Duroc pig from a farm at the University of Illinois will now be among the growing list of domesticated animals that have had their genomes sequenced.

“The pig is a unique animal that is important for food and that is used as an animal model for human disease,” said Larry Schook, a University of Illinois professor of biomedical sciences and leader of the sequencing project. “And because the native wild animals are still in existence, it is a really exciting animal to look at to learn about the genomic effects of domestication.” he said.

UK scientists have contributed to both the sequencing, conducted primarily at the Sanger Institute, and to annotation of the genome (funded by BBSRC), by the Ensembl team at the Sanger Institute, the European Bioinformatics Institute and The Roslin Institute. BBSRC provided support for the UK contribution to the multinational effort through research grant funding and core support to The Roslin Institute. Support for a first sequencing of the pig genome was a key recommendation of a review of BBSRC’s farm animal genomics research in 2005.

“This is a great day for the pig research community,” said Professor Alan Archibald, of The Roslin Institute, “When we launched the international pig gene mapping project almost 20 years ago, few if any of us thought a pig genome sequence was attainable or affordable.”

The Duroc is one of five major breeds used in pork production around the world and is one of about 200 breeds of domesticated pigs. There are also numerous varieties of wild boar, the non-domesticated pigs that are believed to have originated in Eurasia.
The sequencing project involved an international team of scientists and genome-sequencing centres. The USDA National Institute of Food and Agriculture provided $10 million in initial funding. The effort cost about $24.3 million, with additional support from the USDA Agricultural Research Service and other international funders.

The draft sequence, which is about 98% complete, will allow researchers to pinpoint genes that are useful to pork production or are involved in immunity or other important physiological processes in the pig. It will enhance breeding practices, offer insight into diseases that afflict pigs (and, sometimes, also humans) and will assist in efforts to preserve the global heritage of rare, endangered and wild pigs. It also will be important for the study of human health because pigs are very similar to humans in their physiology, behavior and nutritional needs.

“We are excited to have the swine genome sequence and anticipate this will accelerate the rate of genetic improvement in swine as the bovine sequence is impacting the dairy industry’s genetic gains,” said Steve Kappes, deputy administrator of Animal Production and Protection for the USDA Agricultural Research Service.

The pig genome sequence is an essential first tool that will allow scientists to delve into the health, science and natural history of the pig, Schook said.

“This is just the end of the beginning of the process,” he said. “Now we’re just beginning to be able to answer a lot of questions about the pig.”

“We are delighted to have contributed to this important collaboration,” said Professor Allan Bradley, the director of the Wellcome Trust Sanger Institute, which performed most of the sequencing. “This sequence provides a tool of real value in helping the research community to better understand human diseases, in particular by facilitating cardiovascular, pulmonary, gastrointestinal and immunological studies. Thanks to the immediate release of sequence data as it has been produced, the scientific impact of this research is already being felt.”

Biotechnology and Biological Sciences Research Council

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