July 23, 2008, 4:46 PM CT
Why eating less can help the environment
An estimated 19 percent of total energy used in the USA is taken up in the production and supply of food. Currently, this mostly comes from non-renewable energy sources which are in short supply. It is therefore of paramount importance that ways of reducing this significant fuel consumption in the US food system are found. In a paper (1) just reported in the Springer journal Human Ecology, David Pimentel and colleagues at Cornell University in New York set out many strategies which could potentially cut fossil energy fuel use in the food system by as much as 50 percent.
The first, and very astute suggestion they put forward is that individuals eat less, particularly considering that the average American consumes an estimated 3,747 calories a day, a staggering 1200-1500 calories over recommendations. Traditional American diets are high in animal products, and junk and processed foods in particular, which by their nature use more energy than that used to produce staple foods such as potatoes, rice, fruits and vegetables. By just reducing junk food intake and converting to diets lower in meat, the average American could have a massive impact on fuel consumption as well as improving his or her health.
Further savings are possible in the food production industry. The authors suggest that moving towards more traditional, organic farming methods would help because conventional meat and dairy production is extremely energy intensive. Similarly, in crop production, reduced pesticide use, increased use of manure, cover crops and crop rotations improve energy efficiency.........
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July 23, 2008, 4:43 PM CT
Want a reason to love your lower belly fat?
Fat removed from the lower abdomen and inner thigh through liposuction was found to be an excellent source of stem cells, with higher stem cell concentrations than other areas of the body, reports a Brazilian-based study in August's Plastic and Reconstructive Surgery
, the official medical journal of the American Society of Plastic Surgeons (ASPS). This is the first study of its kind to examine whether fat tissues from different areas of the body vary in stem cell concentration.
"Adult stem cells, derived from our own tissues, hold strong promise for improved clinical therapies," said J. Peter Rubin, MD, a member of the ASPS Fat Grafting Task Force who is involved in pre-clinical trial work on stem cells taken from fat. "The potential for healing and repairing injury or disease through stem cells, including conditions like breast cancer and reconstruction, heart failure, spinal injuries, diabetes and Parkinson's disease are incredible. We may be able to more permanently and naturally get rid of pesky wrinkles or augment breasts with stem cell enriched fat in the future as well. Knowing more about the biology of stem cells will be of great value when we are ready for clinical trials in this country".
In the study, 23 female patients having liposuction in at least four different body areas agreed to have their fat isolated for adult stem cells and analyzed to determine stem cell concentrations. The body areas that were liposuctioned were: lower abdomen, upper abdomen, inner knee, inner thigh, flank and hips.........
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July 23, 2008, 4:40 PM CT
Giving The Right Exercise Advice
It is common knowledge that regular exercise supports physical and mental well-being. Despite this and recommendations from health care providers, the majority of patients with chronic illnesses remain inactive. In a new study, University of Missouri scientists observed that adults with chronic illness who received interventions focused on behavior-changing strategies significantly increased their physical activity levels. In contrast, interventions based on cognitive approaches, which attempt to change knowledge, beliefs and attitudes, and are most usually used by health care providers, did not improve physical activity.
"The information that physicians are giving patients isn't working. Patients are not motivated when they hear 'exercise is good; it will improve your health.' What works is providing patients with simple, action-orientated strategies to increase their activity levels," said Vicki Conn, professor and associate dean of research in the MU Sinclair School of Nursing.
Behavior strategies include feedback, goal setting, self-monitoring, and stimulus or cues. Self-monitoring, any method where participants record and track their activity over time, significantly increased awareness and provided motivation for improvement, Conn said.........
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July 23, 2008, 4:37 PM CT
Human visual system could make powerful computer
Since the idea of using DNA to create faster, smaller, and more powerful computers originated in 1994, researchers have been scrambling to develop successful ways to use genetic code for computation. Now, new research from a professor at Rensselaer Polytechnic Institute suggests that if we want to carry out artificial computations, all we have to do is literally look around.
Assistant Professor of Cognitive Science Mark Changizi has begun to develop a technique to turn our eyes and visual system into a programmable computer. His findings are published in the latest issue of the journal Perception
Harnessing the computing power of our visual system, as per Changizi, requires visually representing a computer program in such a way that when an individual views the representation, the visual system naturally carries out the computation and generates a perception.
Ideally, we would be able to glance at a complex visual stimulus (the software program), and our visual system (the hardware) would automatically and effortlessly generate a perception, which would inform us of the output of the computation, Changizi said.
Changizi has begun successfully applying his approach by developing visual representations of digital circuits. A large and important class of computations used in calculators, computers, phones, and most of today's electronic products, digital circuits are constructed from assemblies of logic gates, and always have an output value of zero or one.........
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July 23, 2008, 4:34 PM CT
Exercise could be the heart's fountain of youth
Absence may make the heart grow fonder, but endurance exercise seems to make it younger. As per a research studyconducted at Washington University School of Medicine in St. Louis, older people who did endurance exercise training for about a year ended up with metabolically much younger hearts. The scientists also showed that by one metabolic measure, women benefited more than men from the training.
"We know that the heart deteriorates as people get older, and that's largely because they don't stay as active as they used to," says first author Pablo F. Soto, M.D., instructor in medicine in the Cardiovascular Division. "Past research has suggested that exercise can reverse some effects of aging, and we wanted to see what effect it would have specifically on the heart."
The scientists measured heart metabolism in sedentary older people both at rest and during administration of dobutamine, a drug that makes the heart race as if a person were exercising vigorously. At the start of the study, they observed that in response to the increased energy demands produced by dobutamine, the hearts of the study subjects didn't increase their uptake of energy in the form of glucose (blood sugar).
But after endurance exercise training which involved walking, running or cycling exercises three to five days a week for about an hour per session the participants' hearts doubled their glucose uptake during high-energy demand, just as younger hearts do.........
Posted by: Daniel Read more Source
July 23, 2008, 4:24 PM CT
Omega-3 Fatty Acids Could Slow Acute Wound Healing
A recent study shows that popular fish oil supplements have an effect on the healing process of small, acute wounds in human skin. But whether that effect is detrimental, as scientists initially suspected, remains a mystery.
The omega-3 fatty acids found in fish oils are widely considered to benefit cardiovascular health and other diseases correlation to chronic inflammation because of their anti-inflammatory properties. But insufficient inflammation during the initial stage of wound healing may delay the advancement of later stages.
In the study, blister wounds on the arms of people taking fish oil supplements were in comparison to the wounds of people taking a placebo. The wounds healed in about the same amount of time - but at the local cellular level, something unexpected happened. The levels of proteins linked to initiating and sustaining inflammation were higher in the blister fluid in people who had taken the active fish oil supplements. The scientists had expected those proteins to be lowered by the increased systemic presence of omega-3 fatty acids in the blood.
"That finding was hard to explain," said Jodi McDaniel, lead author of the study and an assistant professor of nursing at Ohio State University. "These proteins may have other functions that we don't yet fully understand. And our results also suggested there could be a difference between men and women in the amount of inflammatory proteins that are produced, because on average, women had lower levels of one of the proteins." .........
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July 22, 2008, 8:30 PM CT
How carrots help us see the color orange
One of the easiest ways to identify an object is by its color -- perhaps it is because children's books encourage us to pair certain objects with their respective colors. Why else would so a number of of us automatically assume carrots are orange, grass is green and apples are red?
In two experiments by Holger Mitterer and Jan Peter de Ruiter from the Max Planck Institute for Psycholinguistics, perception of color and color constancy (the ability to see the same color under varying light conditions) were examined using different hues of orange and yellow. By using these hues on different objects, the scientists hoped to show that knowledge of objects can be used to identify color.
In one experiment, half of the participants saw traditionally-colored orange objects in their respective hue, while the other participants saw the same objects in an ambiguous hue between yellow and orange. The participants that saw the ambiguous hue on traditionally-colored orange objects later called the item with that ambiguous hue "orange". Apparently, seeing the ambiguous hue on a traditionally-colored orange objects led participants to redefine that hue to be proper "orange".
In the second experiment, participants saw the same hues, but now on objects that could be any color (e.g., a car). Some participants were shown objects that ranged from the ambiguous color from the first experiment to a strong yellow hue, while others were shown objects in a range of strong orange hues to the ambiguous color. Just as in the first experiment, participants then had to identify a sock that had been colored with an ambiguous hue. This second experiment revealed no differences between the two groups, showing conclusively that it was only the knowledge of how objects are naturally colored that made them redefine the colors in the first experiment.........
Posted by: JoAnn Read more Source
July 22, 2008, 8:03 PM CT
No need for gene screens in breast cancer families
Research reported today should provide relief to women who are worried after a relative's breast cancer diagnosis. The study in the open access journal BMC Cancer
shows that a family history of breast cancer does not give a useful indication of the likelihood that a woman will develop it herself at an early age.
An increased risk of breast cancer for relatives of patients with breast cancer has been demonstrated in a number of studies. As physicians and the general population have become more aware of this increased risk, the demand for referring healthy women with a family history of breast cancer for intensive screening or genetic testing has risen. Geertruida H. de Bock led a team from Leiden University Medical Centre in the Netherlands who investigated whether the increased risk was significant enough to accurately predict breast cancer.
As per de Bock, "Due to the low prevalence of early breast cancer in the population, the predictive value of a family history of breast cancer was 13% before the age of 70, 11% before the age of 50, and 1% before the age of 30." These numbers are much lower than most women would probably expect. As the authors explain, "Applying family history related criteria results in the screening of a number of women who will not develop breast cancer at an early age".........
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July 22, 2008, 7:57 PM CT
Has Cancer Spread?
Michael Odell, M.D.
For patients with head and neck cancer, accurately determining how advanced the cancer is and detecting secondary cancers commonly means undergoing numerous tests - until now. New Saint Louis University research has observed that the PET-Computerized axial tomography scanner can be used as a stand-alone tool to detect secondary cancers, which occur in 5 to 10 percent of head and neck cancer patients.
The study findings, which were presented on Tuesday, July 22, at the 7th International Conference on Head and Neck Cancer in San Francisco, Calif., will streamline care for head and neck cancer patients allowing them to begin therapy earlier, says Michael Odell, M.D., assistant professor of otolaryngology at Saint Louis University School of Medicine.
"There has been a lot of confusion about the best ways to evaluate head and neck cancer patients to see if their cancer has spread," said Odell, the study's primary author.
"Traditionally, doctors used a number of different tests, such as chest X-rays, Computerized axial tomography scans, ultrasounds, bone scans and blood work. Patients went through too a number of unnecessary procedures because there was no real consensus on the best way to evaluate them."
As per Odell, when choosing the appropriate therapy plan for head and neck cancer patients, it is critical to accurately stage the primary cancer and detect secondary cancers. Odell's research shows PET-Computerized axial tomography scanning can replace all the other traditional tests.........
Posted by: Janet Read more Source
July 22, 2008, 7:55 PM CT
Does too much sun cause melanoma?
We are continuously bombarded with messages about the dangers of too much sun and the increased risk of melanoma (the less common and deadliest form of skin cancer), but are these dangers real, or is staying out of the sun causing us more harm than good?
Two experts debate the issue on BMJ.com today.
Sam Shuster, a consultant dermatologist at Norfolk and Norwich University Hospital, says that sun exposure is the major cause of the common forms of skin cancer, which are all virtually benign, but not the rarer, truly cancerous melanoma.
Shuster says that the common skin cancers develop in pale, sun exposed skin and are less frequent in people who avoid the sun and use protection. In contrast, melanoma is correlation to ethnicity rather than pigmentation and in 75% of cases occurs on relatively unexposed sites, particularly on the feet of Africans. Melanoma occurrence decreases with greater sun exposure and can be increased by sunscreens, while sun bed exposure has a small inconsistent effect. Therefore, he concludes, any causative effect of ultraviolet light on melanoma can only be minimal.
There is strong evidence that the reported increase in melanoma incidence is an artefact caused by the incorrect classification of non-malignant naevi as cancerous melanomas, this, he argues, explains why melanoma mortality has changed little despite the great increase in alleged incidence.........
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