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May 15, 2008, 8:23 PM CT

Visual System Equipped With "Future Seeing Powers"

Visual System Equipped With
Catching a football. Maneuvering through a room full of people. Jumping out of the way when a golfer yells "fore." Most would agree these seemingly simple actions require us to perceive and quickly respond to a situation. Assistant Professor of Cognitive Science at Rensselaer Polytechnic Institute Mark Changizi argues they require something more - our ability to foresee the future.

It takes our brain nearly one-tenth of a second to translate the light that hits our retina into a visual perception of the world around us. While a neural delay of that magnitude may seem minuscule, imagine trying to catch a ball or wade through a store full of people while always perceiving the very recent (one-tenth of a second prior) past. A ball passing within one meter of you and traveling at one meter per second in reality would be roughly six degrees displaced from where you perceive it, and even the slowest forward-moving person can travel at least ten centimeters in a tenth of a second.

Changizi claims the visual system has evolved to compensate for neural delays, allowing it to generate perceptions of what will occur one-tenth of a second into the future, so that when an observer actually perceives something, it is the present rather than what happened one-tenth of a second ago. Using his hypothesis, called "perceiving-the-present," he was able to systematically organize and explain more than 50 types of visual illusions that occur because our brains are trying to perceive the near future. His findings are described in May-recent issue of the journal Cognitive Science.........

Posted by: Mike      Read more         Source


May 14, 2008, 8:30 PM CT

Attitudes to stem cell research

Attitudes to stem cell research
Unlike most scientific and technological advances, which tend to take their place silently in society, biotechnology often finds itself the center of public debate and regulatory attention, due partly to the moral issues posed by a number of of its applications.

In this second BBVA Foundation international study on Attitudes to Biotechnology (the first was in 2003), the sample has been enlarged from nine to twelve European countries (Austria, Czech Republic, Gera number of, Denmark, Spain, France, Ireland, Italy, Netherlands, Poland, United Kingdom and Sweden), with the addition of countries from other continents; namely the United States, Japan and Israel. The selection of countries was informed by both their demographical weight and their variability from the standpoint of religious beliefs and cultural traditions.

Information was gathered through 1,500 face-to-face interviews in each country with subjects aged 18 and over (around 22,500 interviewees in all) conducted between April 2007 and February 2008. The design and analysis of the survey were the work of the Department of Social Studies and Public Opinion of the BBVA Foundation.

The present study focuses on attitudes towards one biotechnology application: research with embryos for the purpose of obtaining stem cells. In particular, it analyzes how far public opinion is informed about stem cells, expectations and reservations regarding research with embryonic stem cells and differences in support for such research depending on the origin of the embryos used. Attention also goes to the attitudes held on the creation of hybrid embryos for stem cell research.........

Posted by: Scott      Read more         Source


May 14, 2008, 7:33 PM CT

Alzheimer's-like brain tangles in nonhuman primates

Alzheimer's-like brain tangles in nonhuman primates
Alzheimers brain tangles
Scientists at the Yerkes National Primate Research Center, Emory University, have discovered the first conclusive evidence of Alzheimer's-like neurofibrillary brain tangles in an aged nonhuman primate. The unprecedented finding, described in the online issue of the Journal of Comparative Neurology, has the potential to move the scientific community one step closer to understanding why age-related neurodegenerative diseases, such as Alzheimer's disease, are uniquely human and seem to never fully manifest in other species--including our closest evolutionary relative, the chimpanzee.

Lead scientists Rebecca Rosen, a doctoral student who is conducting her research at Yerkes, and Lary Walker, PhD, a neuroscientist and research professor at Yerkes, in collaboration with colleagues at UCLA, made the unanticipated finding during a routine post-mortem study of an aged, female chimpanzee that died of natural causes. The scientists also discovered deposits of beta-amyloid protein in plaques and blood vessels of the chimp's brain tissue, eventhough these changes were infrequent in comparison to Alzheimer's disease in humans.

"We've seen these plaques in aged chimpanzees before, but this is the first time scientists have found both hallmark features of Alzheimer's disease--plaques and neurofibrillary tangles--in a nonhuman primate," explains Walker.........

Posted by: Daniel      Read more         Source


May 12, 2008, 9:41 PM CT

What's the difference between a human and a fruit fly?

What's the difference between a human and a fruit fly?
Fruit flies are dramatically different from humans not in their number of genes, but in the number of protein interactions in their bodies, as per researchers who have developed a new way of estimating the total number of interactions between proteins in any organism.

The new research, published recently (13 May 2008) in the Proceedings of the National Academy of Sciences journal, shows that humans have approximately 10 times more protein interactions than the simple fruit fly, and 20 times as a number of as simple, single-cell yeast organisms.

This contradicts comparisons between the numbers of genes in different organisms, which yield surprising results: humans have approximately 24,000 genes, but fruit flies are not far behind, with approximately 14,000 genes.

The interaction between different proteins is behind all physiological systems in the human body. When the body digests food, responds to a change in temperature, or fights off an infection, numerous combinations of protein interactions are involved. However, until now it has been impossible to calculate the numbers of interactions that take place within different organisms.

Professor Michael Stumpf from Imperial College Londons Department of Life Sciences, one of the papers authors, explains the significance of the new study, saying:........

Posted by: Scott      Read more         Source


May 11, 2008, 9:16 AM CT

Concerns over childhood and adolescent obesity

Concerns over childhood and adolescent obesity
Study findings presented at the May 2008 Pediatric Academic Societies and Asian Society for Pediatric Research Joint Meeting indicate that childhood and adolescent obesity negatively impacts vascular endothelial function, which relates to cardiac health.

Obesity has been increasing rapidly in the U.S. during the past 20 years and obesity in adults has been associated with cardiovascular disease. The occurence rate of obesity in children is also increasing and a number of cardiovascular diseases that are manifested in adulthood may actually begin in childhood. It is known that healthy endothelium (a single cell layer that lines all blood vessels) is key to maintaining vascular health. Endothelial dysfunction is a primary contributor to atherosclerotic cardiovascular disease (the buildup of fatty deposits on the inside walls of arteries) in adults and is linked to increased risk of heart attacks, stroke, and congestive heart failure. Endothelial function can be measured non-invasively in children using venous occlusion plethysmography (VOP), a technique that measures responses of arm blood vessel responses to an inflatable cuff that externally halts and restarts blood flow. This method has been shown to correlate with coronary artery function in adults with heart disease.........

Posted by: JoAnn      Read more         Source


May 11, 2008, 9:12 AM CT

How body size is regulated?

How body size is regulated?
Researchers are beginning to unravel the question why people distinctly vary in size. In cooperation with researchers of the HelmholtzZentrum M√ľnchen, an international genome-wide study has discovered ten new genes that influence body height and thus provides new insights into biological pathways that are important for human growth.

This meta-analysis, reported in the latest issue of Nature Genetics, is based on data from more than 26,000 study participants. It verifies two already known genes, but also discovered ten new genes. Altogether they explain a difference in body size of about 3.5 centimeters.

The analysis produced some biologically insightful findings. Several of the identified genes are targeted by the microRNA let-7, which affects the regulation of other genes. This connection was completely unknown until now. Several other SNPs may affect the structure of chromatin, the chromosome-surrounding proteins. Moreover, the results could have relevance for patients with inherited growth problems, or with problems in bone development, because some of the newly discovered genes have rare mutations, known to be linked to anomalous skeletal growth. Further functional studies are necessary to completely elucidate the biological mechanisms behind this growing list of genes correlation to height.........

Posted by: JoAnn      Read more         Source


May 8, 2008, 9:00 PM CT

Do antidepressants enhance immune function?

Do antidepressants enhance immune function?
Infection with human immunodeficiency virus (HIV), which leads to acquired immunodeficiency syndrome (AIDS), is an epidemic of global concern. As per the most recent estimates, released in November 2007, by the Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO), an estimated 33.2 million worldwide are living with HIV infection currently. Eventhough the rates of infection appear to be decreasing, there are obviously immense implications for achieving improvements in HIV/AIDS therapy.

The functioning of natural killer (NK) cells, which are a major element of the innate immunity system and are involved in the bodys first line of defense against infections such as HIV, is decreased in both HIV and depression. A group of scientists who have previously observed that stress and depression impair NK cell function and accelerate the course of HIV/AIDS are now publishing a new report in the May 1st issue of Biological Psychiatry.

In this study, they recruited both depressed and non-depressed HIV-infected women and studied the ex vivo effects of three drugs, a selective serotonin reuptake inhibitor (SSRI), a substance P antagonist, and a glucocorticoid antagonist, on their NK cell activity. These drugs were selected because, as the authors state, each affect[s] underlying regulatory systems that have been extensively investigated in both stress and depression research as well as immune and viral research. The researchers observed that the SSRI citalopram, and the substance P antagonist CP 96,345, but not the glucocorticoid receptor antagonist RU486, increased NK cell activity. As per Dr. Dwight Evans, corresponding author of the article: The present findings provide evidence that natural killer cell function in HIV infection may be enhanced by selective serotonin reuptake inhibition and also by substance P antagonism in both depressed and non-depressed individuals.........

Posted by: JoAnn      Read more         Source


May 8, 2008, 8:47 PM CT

New Cancer Gene Discovered

New Cancer Gene Discovered
Scientists at the OU Cancer Institute have identified a new gene that causes cancer. The ground-breaking research appears Monday in Nature's cancer journal Oncogene.

The gene and its protein, both called RBM3, are vital for cell division in normal cells. In cancers, low oxygen levels in the tumors cause the amount of this protein to go up dramatically. This causes cancer cells to divide uncontrollably, leading to increased tumor formation.

Scientists used new powerful technology to genetically "silence" the protein and reduce the level of RBM3 in malignant cells. The approach stopped cancer from growing and led to cell death. The new technique has been tested successfully on several types of cancers - breast, pancreas, colon, lung, ovarian and prostate.

"We are excited about this discovery because most cancers are thought to come from mutations in genes, and our studies, for the first time, have shown that too much of this type of protein actually causes normal cells to turn into cancer cells," said Shrikant Anant, Ph.D., a cancer biologist at the OU Cancer Institute and principal investigator on the project.

Anant said they found RBM3 protein in every stage of a number of cancers, and the amount of protein increased as the cancer grew. The protein helped the cancer grow faster, avoid cell death and was part of the process that formed new blood vessels to feed the tumor.........

Posted by: Janet      Read more         Source


May 6, 2008, 10:41 PM CT

Hunger hormone: makes food look more attractive

Hunger hormone: makes food look more attractive
A new brain-imaging study by scientists at the Montreal Neurological Institute, McGill University reveals that ghrelin - a stomach hormone, acts on specific regions of the brain to enhance our response to food related cues and eating for pleasure. This study, reported in the May 7 issue of Cell Metabolism, is critical to advance understanding and treating obesity, a condition affecting millions world-wide.

Appetite was previously thought of as being controlled by two separate mechanisms: homeostatic and non-homeostatic or hedonic food consumption. Homeostatic feeding is controlled by hormones such as ghrelin, that act on the brain to tell the body when to eat in an attempt to keep a constant body weight. Hedonic consumption is triggered by visual or smell cues. For example, wanting to eat a piece of cake just because it looks good and will bring pleasure when eaten. This study demonstrates that both food consumption behaviours are inter-connected and a key player in their regulation is the stomach hormone ghrelin.

"Our study demonstrates that ghrelin actually activates certain regions of the brain to be more responsive to visual food cues, thereby enhancing the hedonic and incentive responses to food-related cues,' says Dr. Alain Dagher, neurologist at the Montreal Neurological Institute, McGill University and principal investigator in the study. "Ghrelin is a hormone that triggers hunger, and is secreted by the stomach [when it is empty]. An easy analogy would be to think about when you go shopping on an empty stomach, you tend to buy more food and products higher in calories. The reason is that your brain views the food as more appealing, largely due to the action of ghrelin on the brain".........

Posted by: JoAnn      Read more         Source


May 6, 2008, 9:54 PM CT

Safety Of Gene Therapy Using Adult Stem Cells

Safety Of Gene Therapy Using Adult Stem Cells
A new study by UC Davis scientists provides evidence that methods using human bone marrow-derived stem cells to deliver gene treatment to cure diseases of the blood, bone marrow and certain types of cancer do not cause the development of tumors or leukemia. The study was published online in the May 6, 2008 issue of Molecular Therapy.

"The results of our decade-long study of adult human stem cell transplantation shows that there is little risk of adverse events caused by gene transfer, and that adult human stem cells do not pose a cancer risk when implanted into different organs," said Jan Nolta, senior author of the study and director of the UC Davis Stem Cell Program.

Nolta and her colleagues tested the safety of gene transfer into bone marrow stem cells from human donors in more than 600 mice. None of the transplanted mice developed leukemia or solid tumors caused by the gene treatment therapy, during the evaluation period of up to 18 months.

"These data are critical for advancing stem cell research leading toward therapies," Nolta said. "We've shown that adult stem cells follow natural cues to reach target locations, they function normally when they get there and do not exhibit the unchecked cell growth that is the hallmark of cancer."

Gene treatment trials using human bone marrow cells began in the early part of 1990s and have since included roughly 1,000 patients worldwide. In 2000, a leukemia-like condition emerged in three participants in a clinical trial in France, halting the trial and calling into question the safety of the method. Scientists suspected that the gene transferred in this trial gave the transplanted cells an enhanced growth capacity that led to the cancers.........

Posted by: Scott      Read more         Source



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Did you know?
Scientists at Yale have brought to light a mechanism that regulates the way an internal organelle, the Golgi apparatus, duplicates as cells prepare to divide, according to a report in Science Express.Graham Warren, professor of cell biology, and colleagues at Yale study Trypanosoma brucei, the parasite that causes Sleeping Sickness. Like a number of parasites, it is exceptionally streamlined and has only one of each internal organelle, making it ideal for studying processes of more complex organisms that have a number of copies in each cell.

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