Thursday, April 22, 2010

OUR UNIVERSE AT HOME WITHIN A LARGER UNIVERSE?

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IU theoretical physicist Nikodem Poplawski in research published in "Physics Letters B" uses Euclidean-based mathematical modeling to suggest that all black holes may have wormholes inside which exist universes created at the same time as the black holes.

Poplawski takes advantage of the Euclidean-based coordinate system called isotropic coordinates to describe the gravitational field of a black hole and to model the radial geodesic motion of a massive particle into a black hole.

In studying the radial motion through the event horizon (a black hole's boundary) of two different types of black holes -- Schwarzschild and Einstein-Rosen, both of which are mathematically legitimate solutions of general relativity -- Poplawski admits that only experiment or observation can reveal the motion of a particle falling into an actual black hole. But he also notes that since observers can only see the outside of the black hole, the interior cannot be observed unless an observer enters or resides within.

"This condition would be satisfied if our universe were the interior of a black hole existing in a bigger universe," he said. "Because Einstein's general theory of relativity does not choose a time orientation, if a black hole can form from the gravitational collapse of matter through an event horizon in the future then the reverse process is also possible. Such a process would describe an exploding white hole: matter emerging from an event horizon in the past, like the expanding universe."

A white hole is connected to a black hole by an Einstein-Rosen bridge (wormhole) and is hypothetically the time reversal of a black hole. Poplawski's paper suggests that all astrophysical black holes, not just Schwarzschild and Einstein-Rosen black holes, may have Einstein-Rosen bridges, each with a new universe inside that formed simultaneously with the black hole.

"From that it follows that our universe could have itself formed from inside a black hole existing inside another universe," he said.

By continuing to study the gravitational collapse of a sphere of dust in isotropic coordinates, and by applying the current research to other types of black holes, views where the universe is born from the interior of an Einstein-Rosen black hole could avoid problems seen by scientists with the Big Bang theory and the black hole information loss problem which claims all information about matter is lost as it goes over the event horizon (in turn defying the laws of quantum physics).

This model in isotropic coordinates of the universe as a black hole could explain the origin of cosmic inflation, Poplawski theorizes.

(Photo: Indiana U.)

Indiana University

SENSITIVE NERVE CELLS

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In Germany alone, more than 300,000 people are afflicted by Parkinson's disease and the number is growing steadily. However, despite comprehensive research, scientists are still somewhat in the dark as to the molecular changes that trigger this illness. Scientists at the Max Planck Institute of Neurobiology in Martinsried, together with colleagues from Munich and Hamburg, now demonstrated with a new animal model that nerve cells do not begin to die to the extent found in "Parkinson's" until three conditions come together. The results of this study could lead to the development of preventative measures for patients with certain genetic defects, i.e. with a higher predisposition for the disease. These findings are, at any rate, an important step forward in our understanding of this illness.

In the last ten years, various genes that play a role in the outbreak of the hereditary form of Parkinson's disease have been identified. In addition, nerve cell growth factors, such as GDNF, were found to reduce the rate at which nerve cells are destroyed in the brain areas afflicted in Parkinson's disease. However, the hope that this was going to help us towards a better understanding of the disease so far seemed to be unfounded. The treatment with GDNF, as indeed with other, similar growth factors, has not yet left the clinical trial phase. As the brain cells dying in Parkinson's disease are embedded in sensitive brain tissue, their detailed investigation is impossible in humans. The development of animal models in which defined genetic and/or pharmacological manipulations can be made is therefore essential for a good understanding of the molecular and cellular diseases causes. However, a major drawback of Parkinson's research is that so far most animal models fail to display the accelerated loss of nerve cells symptomatic for this illness, thus preventing a thorough analysis of Parkinson's disease mechanisms.

Together with colleagues from the Helmholtz Centre in Munich and the Centre for Molecular Neurobiology in Hamburg, scientists from the Max Planck Institute of Neurobiology in Martinsried have now been able to show that a significant cell death in the brain region afflicted in Parkinson's patients occurs only when three conditions join forces. "Although we had an inkling that this might be the case, we had no actual proof up to now", Liviu Aron explains about his study. In a mouse model, three prerequisites had to be fulfilled: a defective disease gene (in this case the DJ-1 gene), a deficiency in responding to a growth factor and the aging of the animal. In other words, nerve cells which lack the DJ-1 gene and which, in addition, cannot react to the pro-survival signals initiated by the growth factor are particularly prone to die as the mouse ages. "The discovered connection between the response to a growth factor and the DJ-1 gene is extremely interesting", adds Rüdiger Klein, the leader of the study. "Environmental factors influence the supply with growth factors and their interactions with genetic factors may help to better understand Parkinson's disease." The analysis of the complex mechanisms that set in during the process of aging is likely to keep scientists busy for some time.

Complementary genetic investigations into the fruit fly Drosophila revealed that a connection between the growth factor responses and the DJ-1 gene can already be found here. The researchers thus assume that this interaction arose early in evolutionary history and has since then been preserved. This newly discovered connection may open up a new form of therapy for patients with certain genetic defects. Here, a specific medication with GDNF might be more effective in curbing the development of the illness than in other patients. Another vital step towards the goal of finding and fighting the cause of this affliction has been made.

(Photo: Max Planck Institute of Neurobiology / L. Aron)

Max Planck Institute

BELIEF THAT INTENTIONAL WEIGHT LOSS IS HARMFUL TO SENIORS IS UNFOUNDED

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A new study by researchers at Wake Forest University Baptist Medical Center is the first to refute the widely held belief that intentional weight loss in older adults leads to increased risk of death.

In fact, the research shows that seniors who intentionally exercised and/or modified their diets to lose weight were half as likely to die within eight years of follow-up as their peers who did not work toward weight loss, said M. Kyla Shea, Ph.D., first author on the study and a research associate in the Department of Internal Medicine, Section on Gerontology and Geriatric Medicine.

“It was an unusually strong and surprising finding,” Shea said. “Our data suggest that people should not be concerned about trying or recommending weight loss to address obesity-related health problems in older adults.”

The study, funded by the National Institute on Aging, is currently available online and is scheduled to appear in a future print issue of the Journal of Gerontology: Medical Sciences.

Prior to this study, research that has looked at the association between mortality and weight loss has not factored in the many different potential causes of the weight loss. So, using a more rigorous randomized trial approach, Shea and colleagues sought to prove or disprove the idea that older individuals who actively tried to lose weight increased their risk of death.

The research team re-analyzed data from a study of 318 community-dwelling, older adults over age 60, all with knee arthritis, who were enrolled in a trial assessing the effects of weight loss and/or exercise on physical function in the late 1990s. The initial weight-loss intervention took place over a period of 18 months from 1996 through 1998, during which time the 159 individuals in the intervention groups actively lost an average of 10.5 pounds. The non-intervention group lost an average of 3.1 pounds naturally.

The researchers then checked to see if the study participants were still living eight years later.

“Overall, we found that there were far fewer deaths – half the number – in the group of participants that lost weight compared to the group that did not,” Shea said.

The finding was unexpected to seasoned gerontologists.

“For years, the medical community has relied on multiple epidemiological studies that suggested that older people who lost weight were more likely to die,” said Stephen B. Kritchevsky, Ph.D., director of the J. Paul Sticht Center on Aging at the Medical Center. “Weight loss in old folks is just understood to be a bad prognostic sign. The data that people have been using has been unable to separate the cause and effect of the weight loss, however, and our study suggests that the weight loss they’ve been studying may be the result of other health problems and not of intentional weight loss.”

The participants in this study had a constellation of common health problems occurring in aging adults, Kritchevsky added.

“These were the seniors living out in the community, getting around and doing their daily tasks just like your neighbor,” he said. “All were overweight and dealing with the signs of aging when the study started.”

When the researchers evaluated the effect of weight loss in the oldest of the participants –75 and older – they found the same reduction in mortality as they saw in the younger group – those 60 and older – who lost weight.

Weight loss in older adults has been shown to help several medical problems, Kritchevsky said, such as high blood pressure, high cholesterol and high fasting glucose levels. However, physicians have been hesitant to recommend weight loss in older adults because of a concern for mortality based on previous research.

“This study puts to rest a lot of unfounded concerns about how to address the epidemic of obesity among our older adults,” Kritchevsky said.

He cautioned that the study was relatively small and the results should be confirmed in other trials, but that the data gathered from this analysis are sufficient enough to rule out any significant excess risk due to intentional weight loss and to suggest that there may be a mortality benefit to losing the weight, as well.

Wake Forest University Baptist Medical Center

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