January 25, 2011, 8:00 AM CT
Fear Is Quickly Learned During Infancy
There's a reason why Hollywood makes movies like Arachnophobia and Snakes on a Plane: Most people are afraid of spiders and snakes. A new paper published in Current Directions in Psychological Science, a journal of the Association for Psychological Science, reviews research with infants and toddlers and finds that we aren't born afraid of spiders and snakes, but we can learn these fears very quickly.
One theory about why we fear spiders and snakes is because so a number of are poisonous; natural selection may have favored people who stayed away from these dangerous critters. Indeed, several studies have observed that it's easier for both humans and monkeys to learn to fear evolutionarily threatening things than non-threatening things. For example, research by Arne Ohman at the Karolinska Institute in Sweden, you can teach people to associate an electric shock with either photos of snakes and spiders or photos of flowers and mushrooms-but the effect lasts a lot longer with the snakes and spiders. Similarly, Susan Mineka's research (from Northwestern University) shows that monkeys that are raised in the lab aren't afraid of snakes, but they'll learn to fear snakes much more readily than flowers or rabbits.
The authors of the Current Directions in Psychological Science paper have studied how infants and toddlers react to scary objects. In one set of experiments, they showed infants as young as 7 months old two videos side by side-one of a snake and one of something non-threatening, such as an elephant. At the same time, the scientists played either a fearful voice or a happy voice. The babies spent more time looking at the snake videos when listening to the fearful voices, but showed no signs of fear themselves.........
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January 25, 2011, 7:48 AM CT
Unrealistic optimism common in early cancer trials
Can optimism be ethically problematic? Yes, as per a newly released study, which found unrealistic optimism prevalent among participants in early-phase cancer trials and suggested that it may compromise informed consent.
A number of cancer scientists and ethicists assume that hope and optimism in the research context are "always ethically benign, without considering the possibility that they reflect a bias," write the authors of the study, which appears in IRB: Ethics & Human Research
"Others have claimed that unrealistic expectations for benefit are a result of misunderstanding and that the proper response to them is to provide patient-subjects with more information�" But the study cast doubt on both assumptions.
The study included 72 patients with cancer who were enrolled in early-phase oncology trials in the New York metropolitan area between August 2008 and October 2009. Questionnaires assessed signs of unrealistic optimism, as well as participants' understanding of the trials' purpose. Unrealistic optimism, which social psychology experts define as being specific to a situation and consider a form of bias, is distinct from "dispositional optimism," which is a general outlook on life and is neither realistic nor unrealistic. Individuals can have one form of optimism without the other.........
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January 25, 2011, 7:41 AM CT
Practicing retrieval is best tool for learning
Research findings by Jeffrey D. Karpicke, a Purdue assistant professor of psychological sciences who studies learning and memory, show that the time students invest in rereading or reviewing their notes would be better spent practicing retrieval, such as self-testing, to ensure better learning. (Purdue University photo/Andrew Hancock)
The time students invest in rereading or reviewing their notes would be better spent practicing retrieval to ensure better learning, as per new research from Purdue University.
"We continue to show that practicing retrieval, or testing yourself, is a powerful, robust tool for learning," said Jeffrey D. Karpicke (pronounced CAR-picky), an assistant professor of psychological sciences who studies learning and memory. "Our new research shows that practicing retrieval is an even more effective strategy than engaging in elaborative studying.
"Educators, scientists and students are often focused on getting things 'in memory,' so techniques that encourage students to elaborate on the material are often popular. But learning is fundamentally about retrieving, and our research shows that practicing retrieval while you study is crucial to learning. Self-testing enriches and improves the learning process, and there needs to be more focus on using retrieval as a learning strategy".
He also observed that most students are not good at judging the success of their study habits.
"When students have the material right in front of them, they think they know it better than they actually do," he said. "A number of students do not realize that putting the material away and practicing retrieval is such a potent study strategy".........
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January 25, 2011, 7:26 AM CT
Conversion of brain tumor cells into blood vessels
Glioblastoma tumor cells (shown in green) can transform into endothelial cells (shown in red), which line the interior surface of a tumor vessel.
Credit: Courtesy of Dr. Yasushi Soda, Salk Institute for Biological Studies
Glioblastoma, the most common and lethal form of brain cancer and the disease that killed Massachusetts Senator Ted Kennedy, resists nearly all therapy efforts, even when attacked simultaneously on several fronts. One explanation can be found in the tumor cells' unexpected flexibility, discovered scientists at the Salk Institute for Biological Studies.
When faced with a life-threatening oxygen shortage, glioblastoma cells can shift gears and morph into blood vessels to ensure the continued supply of nutrients, reports a team led by Inder Verma, Ph.D., in a feature article in this week's issue of the Proceedings of the National Academy of Sciences
Their study not only explains why cancer therapys that target angiogenesis--the growth of a network of blood vessels that supplies nutrients and oxygen to malignant tissues--routinely fail in glioblastoma, but the findings may also spur the development of drugs aimed at novel targets.
"This surprising effect of anti-angiogenic treatment with drugs such as Avastin tells us that we have to rethink glioblastoma combination treatment," says senior author Verma, a professor in the Laboratory of Genetics and holder of the Irwin and Joan Jacobs Chair in Exemplary Life Science. "Disrupting the formation of tumor blood vessels is not enough; we also have to prevent the conversion of tumor cells into blood vessels cells".........
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January 25, 2011, 7:24 AM CT
'Engineered organ' model for breast cancer research
Purdue researchers' new model for breast cancer research, called "breast on-a-chip," mimics the branching mammary duct system. (Purdue University/Leary laboratory - Reproduced by permission of The Royal Society of Chemistry)
Purdue University scientists have reproduced portions of the female breast in a tiny slide-sized model dubbed "breast on-a-chip" that will be used to test nanomedical approaches for the detection and therapy of breast cancer.
The model mimics the branching mammary duct system, where most breast cancers begin, and will serve as an "engineered organ" to study the use of nanoparticles to detect and target tumor cells within the ducts.
Sophie Lelièvre, associate professor of basic medical sciences in the School of Veterinary Medicine, and James Leary, SVM Professor of Nanomedicine and professor of basic medical sciences in the School of Veterinary Medicine and professor of biomedical engineering in the Weldon School of Biomedical Engineering, led the team.
Purdue team creates 'engineered organ' model for breast cancer research.
Januarty 20, 2011 Print Version.
Purdue researchers' new model for breast cancer research, called "breast on-a-chip," mimics the branching mammary duct system. (Purdue University/Leary laboratory - Reproduced by permission of The Royal Society of Chemistry).
WEST LAFAYETTE, Ind. - Purdue University scientists have reproduced portions of the female breast in a tiny slide-sized model dubbed "breast on-a-chip" that will be used to test nanomedical approaches for the detection and therapy of breast cancer.........
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January 25, 2011, 7:10 AM CT
Workers most invested in their jobs have highest stress levels
A workplace's key employees appears to be at the greatest risk of experiencing high levels of work stress, as per a newly released study by the Centre for Addiction and Mental Health (CAMH).
In a survey of 2,737 workers, 18 per cent reported that their job was "highly stressful."
The odds of having high stress were greater if workers were managers or professionals, if they thought their poor job performance could negatively affect others, or if they worked long or variable hours. The study was published in this month's International Journal of Occupational and Environmental Medicine
"The people who report high stress are the ones most invested in their jobs," says Dr. Carolyn Dewa, Senior Scientist and Head of CAMH's Work and Well-being Research and Assessment Program. "Employers should be very concerned with keeping this population healthy. From a business perspective, it is in a company's best interest to support these workers." .
The job characteristics linked to stress pointed to workers who were engaged and responsible. If workers felt their poor job performance could result in any physical injury, damage to company's equipment or reputation, or a financial loss, they were twice as likely to report high stress.
Having a worksite remote from their home, or having to entertain or travel for their jobs also increased the odds of being stressed. So did variable hours such as being on call, doing shift work or having a compressed work week.........
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January 22, 2011, 6:34 AM CT
Preventing tooth decay in the youngest American Indians
The dark stained decay is irreversible loss of tooth tissue that must be repaired with dental treatment. The white patch on the tooth is an earlier stage of decay which can be stopped without drilling and filling.
Credit: Andrea Ferreira Zandoná, DDS, PhD, Indiana University School of Dentistry
-A study conducted in four American Indian communities in the Pacific Northwest presents an effective strategy to convince mothers to switch young children from drinking sweetened soda to water and shows that eliminating these sugary drinks from the diets of the youngest members of the tribe significantly decreased tooth decay.
The results of the dental arm of "The Toddler Overweight and Tooth Decay Prevention Study" (TOTS), which targeted American Indians from birth to 30 months of age, appear in the current issue (Volume 20, Number 4) of the peer evaluated journal Ethnicity & Disease
The arrival of Europeans brought diseases such as measles, influenza and smallpox to the Americas. Less well known is that Europeans also brought premature tooth decay to American Indians by introducing sugar and sugared foods. Before the adoption of European food patterns, tooth decay was mostly a disease of old age in the New World. With the addition of sugar to the American Indian diet, tooth decay became a disease that begins early in life. Today American Indians of all ages, a number of without adequate or timely access to dental care, are severely affected by tooth decay.
To implement TOTS the scientists worked closely with tribal councils. In three of the four communities, good tasting water was made readily available in water fountains and inexpensive, refillable gallon jugs. Sugared soda was removed from tribal stores, and substitution of water for soda was actively encouraged through community outreach programs. Families received food counseling and breastfeeding support through tribal community health workers.........
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January 22, 2011, 6:32 AM CT
Defense mechanism against bacteria
Under standard laboratory conditions, the human beta-defensin 1 (hBD-1), a human antibiotic naturally produced in the body, had always shown only little activity against microbes. Nevertheless the human body produces it in remarkable quantities. The solution to the puzzle was the investigation process itself, as the research group led by Dr. Jan Wehkamp at the Dr. Margarete Fischer-Bosch Institute for Clinical Pharmacology of the Stuttgart-based Robert Bosch Hospital found out.
Before the research group took a new approach to this research, defensins were commonly tested in the presence of oxygen, eventhough little oxygen is present, for example, in the human intestine. Starting out from the discovery that a special antibiotic-activating protein of the human body is diminished in patients with inflammatory bowel diseases, Crohn's Disease and Ulcerative Colitis, the working group investigated how defensins act under low-oxygen conditions. During their investigations the researchers found out that under these conditions hBD-1 unfolds a strong antibiotic activity against lactic acid bacteria and yeast.
Furthermore the scientists discovered that another human protein, thioredoxin, is able to activate beta-defensin 1 even in the presence of oxygen. Moritz Marcinowski and Professor Johannes Buchner from the Department of Chemistry at the Technical University of Munich, used circular dichroism spectroscopy to elucidate the differences between the folded inactive and the unfolded active form of the protein.........
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January 21, 2011, 10:34 PM CT
Meditation changes brain structure
Participating in an 8-week mindfulness meditation program appears to make measurable changes in brain regions linked to memory, sense of self, empathy and stress. In a study that will appear in the January 30 issue of Psychiatry Research: Neuroimaging,
a team led by Massachusetts General Hospital (MGH) scientists report the results of their study, the first to document meditation-produced changes over time in the brain's grey matter.
"Eventhough the practice of meditation is linked to a sense of peacefulness and physical relaxation, practitioners have long claimed that meditation also provides cognitive and psychological benefits that persist throughout the day," says Sara Lazar, PhD, of the MGH Psychiatric Neuroimaging Research Program, the study's senior author. "This study demonstrates that changes in brain structure may underlie some of these reported improvements and that people are not just feeling better because they are spending time relaxing".
Prior studies from Lazar's group and others found structural differences between the brains of experienced mediation practitioners and individuals with no history of meditation, observing thickening of the cerebral cortex in areas linked to attention and emotional integration. But those investigations could not document that those differences were actually produced by meditation.........
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January 21, 2011, 8:32 PM CT
Genetic code for form of pancreatic cancer
Researchers at Johns Hopkins have deciphered the genetic code for a type of pancreas cancer, called neuroendocrine or islet cell tumors. The work, described online in the Jan. 20 issue of Science
Express, shows that patients whose tumors have certain coding "mistakes" live twice as long as those without them.
"One of the most significant things we learned is that each patient with this kind of rare cancer has a unique genetic code that predicts how aggressive the disease is and how sensitive it is to specific therapys," says Nickolas Papadopoulos, Ph.D., associate professor at the Johns Hopkins Kimmel Cancer Center and director of translational genetics at Hopkins' Ludwig Center. "What this tells us is that it appears to be more useful to classify cancers by gene type rather than only by organ or cell type."
Pancreatic neuroendocrine cancers account for about five percent of all pancreas cancers. Some of these tumors produce hormones that have noticeable effects on the body, including variations in blood sugar levels, weight gain, and skin rashes while others have no such hormone "signal".
In contrast, hormone-free tumors grow silently in the pancreas, and "a number of are difficult to distinguish from other pancreas cancer types," as per Ralph Hruban, M.D., professor of pathology and oncology, and director of the Sol Goldman Pancreatic Cancer Research Center at Johns Hopkins.........
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