Oct. 17, 2013 — This is the best-preserved fossil find yet from the early era of our genus. The particularly interesting aspect is that it displays a combination of features that were unknown to us before the find. The skull, found in Dmanisi by anthropologists from the University of Zurich as part of a collaboration with colleagues in Georgia funded by the Swiss National Science Foundation, has the largest face, the most massively built jaw and teeth and the smallest brain within the Dmanisi group.find yet from the early era of our genus. The particularly interesting aspect is that it displays a combination of features that were unknown to us before the find. The skull, found in Dmanisi by anthropologists from the University of Zurich as part of a collaboration with colleagues in Georgia funded by the Swiss National Science Foundation, has the largest face, the most massively built jaw and teeth and the smallest brain within the Dmanisi group. It is the fifth skull to be discovered in Dmanisi. Previously, four equally well-preserved hominid skulls as well as some skeletal parts had been found there. Taken as a whole, the finds show that the first representatives of the genus Homo began to expand from Africa through Eurasia as far back as 1.85 million years ago.Diversity within a species instead of species diversityBecause the skull is completely intact, it can provide answers to various questions which up until now had offered broad scope for speculation. These relate to none less than the evolutionary beginning of the genus Homo in Africa around two million years ago at the beginning of the Ice Age, also referred to as the Pleistocene. …Leggi il seguito
Oct. 17, 2013 — Modest increases in marketing and outreach to local communities can increase the amount of physical activity that occurs in parks, providing a cost-effective way to potentially improve a community’s health, according to a new RAND Corporation study.The project, which examined 50 parks across Los Angeles, found that simple interventions such as increased signage boosted physical activity by 7 to 12 percent over the study period in relation to parks that did not make changes. The findings are published online by the American Journal of Preventive Medicine.”The study shows that environmental cues influence and change individual behavior, including physical behavior,” said Dr. Deborah A. Cohen, the study’s lead author and a senior natural scientist at RAND, a nonprofit research organization. “When physical activity opportunities and reminders become more obvious, whether they are overt signs or notices for classes or new walking paths, they may lead people to becoming more active, especially if they are already in a park.”Although most Americans live in a community with a network of parks and recreation facilities suited to exercise, most do not meet the national guidelines for physical activity. Those recommendations suggest adults engage in physical activity for 150 minutes per week, while children should do so for 60 minutes per day.An increase in physical activity among people in Finland over the past few decades has been attributed, in part, to an increased focus on local parks and sports facilities. In contrast, many U.S. municipalities — including Los Angeles — have trimmed support for public physical activity programs and parks.RAND researchers wanted to examine whether, given limited resources, parks could adjust their programming and outreach efforts to increase activity if they had better information about local use and activity preferences. The second question was whether the involvement of park advisory boards composed of community members would help improve the decisions made by park directors.To conduct the project, 50 parks in the City of Los Angeles that included a recreation center and full-time staff were randomized into three groups. …Leggi il seguito
May 29, 2013 — Improvements in crop water productivity — the amount of food produced per unit of water consumed — have the potential to improve both food security and water sustainability in many parts of the world, according to a study published online in Environmental Research Letters May 29 by scientists with the University of Minnesota’s Institute on the Environment (IonE) and the Institute of Crop Science and Resource Conservation (INRES) at the University of Bonn, Germany.
Led by IonE postdoctoral research scholar Kate A. Brauman, the research team analyzed crop production, water use and crop water productivity by climatic zone for 16 staple food crops: wheat, maize, rice, barley, rye, millet, sorghum, soybean, sunflower, potato, cassava, sugarcane, sugar beet, oil palm, rapeseed (canola) and groundnut (peanut). Together these crops constitute 56 percent of global crop production by tonnage, 65 percent of crop water consumption, and 68 percent of all cropland by area. The study is the first of its kind to look at water productivity for this many crops at a global scale.
The wide range of variation in crop water productivity in places that have similar climates means that there are lots of opportunities for improving the trade-off between food and water. And the implications of doing so are substantial: The researchers calculated that in drier regions, bringing up the very lowest performers to just the 20th percentile could increase annual production on rain-fed cropland enough to provide food for an estimated 110 million people without increasing water use or using additional cropland. On irrigated cropland, water consumption could be reduced enough to meet the annual domestic water demands of nearly 1.4 billion people while maintaining current production.
“Since crop production consumes more freshwater than any other human activity on the planet, the study has significant implications for addressing the twin challenges of water stress and food insecurity,” says Brauman.
For example, if low crop water productivity in precipitation-limited regions were raised to the 20th percentile of water productivity, specific to particular crops and climates, total rain-fed food production in Africa could be increased by more than 10 percent without exploiting additional cropland. Similar improvements in crop water productivity on irrigated cropland could reduce total water consumption some 8-15 percent in precipitation-limited regions of Africa, Asia, Europe and South America.
Because the study is global in scope, it is able to identify potential locations for interventions, crops to pay attention to, and opportunities for the biggest improvements in crop water management. Specific solutions for improving crop per drop will vary by location and climatic zone over time, however.Leggi il seguito
May 28, 2013 — The offspring of parents who live to a ripe old age are more likely to live longer themselves, and less prone to cancer and other common diseases associated with ageing, a study has revealed.
Experts at the University of Exeter Medical School, supported by the National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care in the South West Peninsula (NIHR PenCLAHRC), led an international collaboration which discovered that people who had a long-lived mother or father were 24% less likely to get cancer. The scientists compared the children of long-lived parents to children whose parents survived to average ages for their generation.
The scientists classified long-lived mothers as those who survived past 91 years old, and compared them to those who reached average age spans of 77 to 91. Long-lived fathers lived past 87 years old, compared with the average of 65 to 87 years. The scientists studied 938 new cases of cancer that developed during the 18 year follow-up period.
The team also involved experts from the National Institute for Health and Medical Research in France (Institut national de la santé et de la recherche médicale), the University of Michigan and the University of Iowa. They found that overall mortality rates dropped by up to 19 per cent for each decade that at least one of the parents lived past the age of 65. For those whose mothers lived beyond 85, mortality rates were 40 per cent lower. The figure was a little lower (14 per cent) for fathers, possibly because of adverse lifestyle factors such as smoking, which may have been more common in the fathers.
In the study, published in the Journals of Gerontology: Series A, the scientists analysed data from a series of interviews conducted with 9,764 people taking part in the Health and Retirement Study. The participants were based in America, and were followed up over 18 years, from 1992 to 2010. They were interviewed every two years, with questions including the ages of their parents and when they died. In 2010 the participants were in their seventies.
Professor William Henley, from the University of Exeter Medical School, said: “Previous studies have shown that the children of centenarians tend to live longer with less heart disease, but this is the first robust evidence that the children of longer-lived parents are also less likely to get cancer. We also found that they are less prone to diabetes or suffering a stroke. These protective effects are passed on from parents who live beyond 65 — far younger than shown in previous studies, which have looked at those over the age of 80. Obviously children of older parents are not immune to contracting cancer or any other diseases of ageing, but our evidence shows that rates are lower. We also found that this inherited resistance to age-related diseases gets stronger the older their parents lived.”
Ambarish Dutta, who worked on the project at the University of Exeter Medical School and is now at the Asian Institute of Public Health at the Ravenshaw University in India, said: “Interestingly from a nature versus nurture perspective, we found no evidence that these health advantages are passed on from parents-in-law. Despite being likely to share the same environment and lifestyle in their married lives, spouses had no health benefit from their parents-in-law reaching a ripe old age. If the findings resulted from cultural or lifestyle factors, you might expect these effects to extend to husbands and wives in at least some cases, but there was no impact whatsoever.”
In analysing the data, the team made adjustments for sex, race, smoking, wealth, education, body mass index, and childhood socioeconomic status. They also excluded results from those whose parents died prematurely (ie mothers who died younger than 61 or fathers younger than 46).
The study could not look at the various sub groups of cancer, as numbers did not allow accurate estimates. This study was carried out in preparation for a more detailed analysis of factors explaining why some people seem to age more slowly than others. Future work will use the UK Biobank, which analyses a cohort of 500,000 participants.
Other collaborators on the paper were Dr Jean-Marie Robine, of the Institut National de la Santé et de la Recherche Médical, Dr Kenneth Langa of the University of Michigan, Professor Robert Wallace of the University of Iowa and Professor David Melzer, of the University of Exeter Medical School.Leggi il seguito
Mar. 14, 2013 — Green tea and coffee may help lower your risk of having a stroke, especially when both are a regular part of your diet, according to research published in Stroke: Journal of the American Heart Association.
“This is the first large-scale study to examine the combined effects of both green tea and coffee on stroke risks,” said Yoshihiro Kokubo, M.D., Ph.D., F.A.H.A., F.A.C.C., F.E.S.C., lead author of the study at Japan’s National Cerebral and Cardiovascular Center. “You may make a small but positive lifestyle change to help lower the risk of stroke by adding daily green tea to your diet.”
Researchers asked 83,269 Japanese adults about their green tea and coffee drinking habits, following them for an average 13 years. They found that the more green tea or coffee people drink, the lower their stroke risks.
People who drank at least one cup of coffee daily had about a 20 percent lower risk of stroke compared to those who rarely drank it.
People who drank two to three cups of green tea daily had a 14 percent lower risk of stroke and those who had at least four cups had a 20 percent lower risk, compared to those who rarely drank it.
People who drank at least one cup of coffee or two cups of green tea daily had a 32 percent lower risk of intracerebral hemorrhage, compared to those who rarely drank either beverage. (Intracerebral hemorrhage happens when a blood vessel bursts and bleeds inside the brain. About 13 percent of strokes are hemorrhagic.)
Participants in the study were 45 to 74 years old, almost evenly divided in gender, and were free from cancer and cardiovascular disease.
During the 13-years of follow-up, researchers reviewed participants’ hospital medical records and death certificates, collecting data about heart disease, strokes and causes of death. They adjusted their findings to account for age, sex and lifestyle factors like smoking, alcohol, weight, diet and exercise.
Green tea drinkers in the study were more likely to exercise compared to non-drinkers.
Previous limited research has shown green tea’s link to lower death risks from heart disease, but has only touched on its association with lower stroke risks. Other studies have shown inconsistent connections between coffee and stroke risks.
Initial study results showed that drinking more than two cups of coffee daily was linked to increasing coronary heart disease rates in age- and sex-adjusted analysis. But researchers didn’t find the association after factoring in the effects of cigarette smoking — underscoring smoking’s negative health impact on heart and stroke health.
A typical cup of coffee or tea in Japan was approximately six ounces. “However, our self-reported data may be reasonably accurate, because nationwide annual health screenings produced similar results, and our validation study showed relatively high validity.” Kokubo said. “The regular action of drinking tea, coffee, largely benefits cardiovascular health because it partly keeps blood clots from forming.”
Tea and coffee are the most popular drinks in the world after water, suggesting that these results may apply in America and other countries.
It’s unclear how green tea affects stroke risks. A compound group known as catechins may provide some protection. Catechins have an antioxidant anti-inflammatory effect, increasing plasma antioxidant capacity and anti-thrombogenic effects.
Some chemicals in coffee include chlorogenic acid, thus cutting stroke risks by lowering the chances of developing type 2 diabetes.
Further research could clarify how the interaction between coffee and green tea might help further lower stroke risks, Kokubo said.
Co-authors are: Isao Saito, M.D., Ph.D.; Kazumasa Yamagishi, M.D., Ph.D.; Hiroshi Yatsuya, M.D., Ph.D.; Junko Ishihara, Ph.D.; Manami Inoue, M.D., Ph.D.; and Shoichiro Tsugane, M.D., Ph.D.
The study was supported by Grants-in-Aid for Cancer Research and the Third-Term Comprehensive Ten-Year Strategy for Cancer Control from the Ministry of Health, Labour and Welfare of Japan.Leggi il seguito
May 29, 2013 — People lie about their health related behaviors. It’s a problem that has long bedeviled health research on issues ranging from diet to exercise to smoking. And it’s not just that we have faulty memories. Many of us stretch the truth to make ourselves seem more virtuous in the eyes of the person in the white coat. That makes drawing conclusions about behaviors that affect health from self-reported records tricky.
Kusum Ailawadi, the Charles Jordan 1911 TU’12 Professor of Marketing at Tuck, has found a way around this problem — at least with regard to diet. Ailawadi and her colleagues examined data on several years of household food purchases from a marketing database that tracks what people buy at the store by having them scan their groceries with a device at home.
Paired with information on the same consumers’ health status and other demographics and data on the nutritional content of groceries, the researchers were able to track the link between factors such as income, food price, self-control, and health knowledge and the nutritional quality of their food purchases. “We know that recall is not accurate and we know people, especially obese people, are hesitant to admit to unhealthy eating,” says Ailawadi. “We were interested in actual purchasing behavior.”
The researchers were also able to study how food-buying patterns changed in the household following one member’s diagnosis of Type 2 diabetes, a chronic disease strongly linked with obesity. The latter point is of particular interest to Ailawadi given the expanding obesity epidemic and the ensuing scrutiny of processed food companies’ marketing practices.
According to the Centers for Disease Control and Prevention, the number of Americans with diabetes has more than tripled in the last 30 years to 20.9 million. As many as 95 percent of the cases are Type 2 diabetes and tens of millions more Americans are considered pre-diabetic, a situation that has helped lead to bans on trans fats and large servings of sugary drinks in New York City.
Some of the researchers’ findings were expected. In families where the head of household is highly educated and interested in nutrition, purchases of fatty and sugary foods were lower than in others. But price had the greatest effect by far on the healthfulness of peoples’ food purchases. In families where there was a Type 2 diabetes diagnosis, total purchases of sugary foods declined. Other results were more surprising. The study examined the performance of people with “high self-control,” as defined by healthy practices such as regular exercise and infrequent consumption of fast food or late-night snacks. As expected, the self-controllers bought less junk food like sugary cola and potato chips. Yet they offset this benefit with greater quantity of “healthy foods” like yogurt and cereal, leading to greater overall consumption of calories and sugar. This paradox of consuming more because of a perception of healthy attributes is known as a “health halo bias.”
“They’re putting more of the healthy foods in their mouths,” says Ailawadi. “They focus on quality and not on quantity: Is a food healthy or unhealthy? Once they categorize it as healthy they don’t focus on how much of it they’re eating.”
The study also finds that households with high levels of education, nutrition interest, and self-control were no better at responding to a diabetes diagnosis than others, although high income spurred improved responses. Also, households where a woman was diagnosed with diabetes or where the patient was younger made healthier changes than households where a man or an older person was diagnosed.
In addition, consumption of fatty foods like processed meats and salty snacks increased in households following a Type 2 diabetes diagnosis — even though doctors advise diabetics to cut both sugar and fat in their diets. As for sugar reduction, it came mainly from high-sugar colas and juices where low-sugar alternatives are easily available. Consumption of treats like cookies and ice cream did not decline following a diabetes diagnosis. “They taste good, they make you feel good,” says Ailawadi. “The human palate loves the combination of fat and sugar so they are hard to resist. And it doesn’t help that less unhealthy versions of these products are sold at a substantial price premium over the high fat/high sugar versions.”Leggi il seguito
May 29, 2013 — A study at the University of California, San Diego School of Medicine identified a protein that is responsible for regulating blood vessel growth by mediating the efficient removal of cholesterol from the cells. Unregulated development of blood vessels can feed the growth of tumors.
The work, led by Yury Miller, MD, PhD, associate professor of medicine at UC San Diego, will be published in the advance online edition of the journal Nature on May 29.
Cholesterol is a structural component of the cell and is indispensable for normal cellular function, although its excess often leads to abnormal proliferation, migration, inflammatory responses or cell death. The researchers studied how the removal of cholesterol from endothelial cells (cells that line the blood vessels) impacts the development of new blood vessels, the process called angiogenesis.
According to Miller, removal of excess cholesterol from endothelial cells is essential for restraining excessive growth of blood vessels.
“Too much cholesterol increases the abundance of lipid rafts, areas in the plasma membrane where surface receptors initiate signaling events leading to angiogenesis,” Miller said. VEGFR2 is such a receptor, playing a central role in the development of blood vessels. Research into the process of angiogenesis suggests that VEGF-induced signaling within endothelial cells is important to tumor growth.
In this study, the scientists show that apoA-I binding protein (AIBP) is secreted by surrounding tissues and facilitates cholesterol removal from endothelial cells. This process interferes with the VEGFR2 receptor function, in turn inhibiting angiogenesis.
“Studying the process in zebrafish, we found that the timing and the pattern of AIBP expression is such that it helps guide segmental arteries to grow strictly in the dorsal direction, instead of an aberrant sideways direction,” said first author Longhou Fang, who added that future studies will explore if AIBP or its derivatives can be used to inhibit pathologic angiogenesis in tumors. Alternatively, blocking AIBP activity in the heart may, in principle, stimulate re-growth of blood vessels after a heart attack.
Additional contributors to the study include Soo-Ho Choi, Ji Sun Baek, Chao Liu, Felicidad Almazan, Philipp Wiesner, Adam Taleb, Elena Deer, Jennifer Pattison and Andrew C. Li, UCSD Department of Medicine; and Florian Ulrich and Jesús Torres-Vázquez, Skirball Institute of Biomolecular Medicine at New York University Langone Medical Center.
The study was funded in part by National Institutes of Health grants HL093767, HL055798 and HL114734; a fellowship from the UC Tobacco-Related Disease Program; and a UCSD Neuroscience Microscopy Facility Grant.Leggi il seguito
May 29, 2013 — Researchers at the Perelman School of Medicine, University of Pennsylvania have developed a new gene therapy to thwart a potential influenza pandemic. Specifically, investigators in the Gene Therapy Program, Department of Pathology and Laboratory Medicine, directed by James M. Wilson, MD, PhD, demonstrated that a single dose of an adeno-associated virus (AAV) expressing a broadly neutralizing flu antibody into the nasal passages of mice and ferrets gives them complete protection and substantial reductions in flu replication when exposed to lethal strains of H5N1 and H1N1 flu virus. These strains were isolated from samples associated from historic human pandemics — one from the infamous 1918 flu pandemic and another from 2009.
Wilson, Anna Tretiakova, PhD, Senior Research Scientist, Maria P. Limberis, PhD, Research Assistant Professor, all from the Penn Gene Therapy Program, and colleagues published their findings online this week in Science Translational Medicine ahead of print. In addition to the Penn scientists, the international effort included colleagues from the Public Health Agency of Canada, Winnipeg; the University of Manitoba, Winnipeg; and the University of Pittsburgh. Tretiakova is also the director of translational research, and Limberis is the director of animal models core, both with the Gene Therapy Program.
“The experiments described in our paper provide critical proof-of-concept in animals about a technology platform that can be deployed in the setting of virtually any pandemic or biological attack for which a neutralizing antibody exists or can be easily isolated,” says Wilson. “Further development of this approach for pandemic flu has taken on more urgency in light of the spreading infection in China of the lethal bird strain of H7N9 virus in humans.”
At the Ready Influenza infections are the seventh leading cause of death in the United States and result in almost 500,000 deaths worldwide per year, according to the Centers for Disease Control. The emergence of a new influenza pandemic remains a threat that could result in a much loss of life and worldwide economic disruption.
There is also interest by the military in developing an off-the-shelf prophylactic vaccine should soldiers be exposed to weaponized strains of infectious agents in biologic warfare.
Human antibodies with broad neutralizing activity against various influenza strains exist but their direct use as a prophylactic treatment is impractical. Now, yearly flu vaccines are made by growing the flu virus in eggs. The viral envelope proteins on the exterior, namely hemagglutinin, are cleaved off and used as the vaccine, but vary from year to year, depending on what flu strains are prevalent. However, high mutation rates in the proteins result in the emergence of new viral types each year, which elude neutralization by preexisting antibodies in the body (specifically specific receptor binding sites on the virus that are the targets of neutralizing antibodies).
This approach has led to annual vaccinations against seasonal strains of flu viruses that are predicted to emerge during the upcoming season. Strains that arise outside of the human population, for example in domestic livestock, are distinct from those that normally circulate in humans, and can lead to deadly pandemics.
These strains are also not effectively controlled by vaccines developed to human strains, as with the 2009 H1N1 pandemic. The vaccine development time for that strain, and in general, was not fast enough to support vaccination in response to an emerging pandemic.
Knowing this, the Penn team proposed a novel approach that does not require the elicitation of an immune response, which does not provide sufficient breadth to be useful against any strain of flu other than the one for which it was designed, as with conventional approaches.
The Penn approach is to clone into a vector a gene that encodes an antibody that is effective against many strains of flu and to engineer cells that line the nasal passages to express this broadly neutralizing antibody, effectively establishing broad-based efficacy against a wide range of flu strains.
A Broad Approach The rational for targeting nasal epithelial cells for antibody expression was to focus this expression to the site of the body where the virus usually enters the body and replicates which is the nasal and oral mucosa. Antibodies are normally expressed from B lymphocytes so one challenge was to design vectors that could deliver antibody genes to the non- lymphoid respiratory cells of the nasal and lung passages and could express functional antibody protein.
Targeting the respiratory cells was achieved through the use of a vector based on a primate virus — AAV9 — which was discovered in the Wilson laboratory and evaluated previously by Limberis for possibly treating patients with cystic fibrosis. The team constructed a genetic payload for AAV9 that expressed an antibody that was showed by other investigators to have broad activity against flu.
Efficacy of the treatment was tested in mice that were exposed to lethal quantities of three strains of H5N1 and two strains of H1N1, all of which have been associated with historic human pandemics (including the infamous H1N1 1918).
Flu virus rapidly replicated in untreated animals all of which needed to be euthanized. However, pretreatment with the AAV9 vector virtually shut down virus replication and provided complete protection against all strains of flu in the treated animals. The efficacy of this approach was also demonstrated in ferrets, which provide a more authentic model of human pandemic flu infection.
“The novelty of this approach is that we’re using AAV and we’re delivering the prophylactic vaccine to the nose in a non-invasive manner, not a shot like conventional vaccines that passively transfer antibodies to the general circulation,” says Limberis.
“There’s a long history of using antibodies for cancer and autoimmune disease, but only two have been approved for infectious diseases,” notes Tretikova. “This novel technique has allowed for the development of a prophylactic passive vaccine that is cost effective, easily administered, and quickly manufactured.”
The team is working with various stakeholders to accelerate the development of this product for pandemic flu and to explore the potential of AAV vectors as generic delivery vehicles for countermeasures of biological and chemical weapons.
The research was supported in part by ReGenX, the Public Health Agency of Canada (#531252), the Canadian Institutes of Health Research (#246355) and the National Institutes of Health (GM083602).Leggi il seguito
May 29, 2013 — Though its surface has been turned to carbon, the bunny-like features can still be easily observed with a microscope. This rabbit sculpture, the size of a typical bacterium, is one of several whimsical shapes created by a team of Japanese scientists using a new material that can be molded into complex, highly conductive 3-D structures with features just a few micrometers across. Combined with state-of-the-art micro-sculpting techniques, the new resin holds promise for making customized electrodes for fuel cells or batteries, as well as biosensor interfaces for medical uses. The research team, which includes physicists and chemists from Yokohama National University, Tokyo Institute of Technology, and the company C-MET, Inc., presents its results in a paper published today in the Optical Society’s (OSA) open-access journal Optical Materials Express.
The work opens a door for researchers trying to create conductive materials in almost any complex shape at the microscopic or cellular level. “One of the most promising applications is 3-D microelectrodes that could interface with the brain,” says Yuya Daicho, graduate student at Yokohama National University and lead author of the paper. These brain interfaces, rows of needle-shaped electrodes pointing in the same direction like teeth on combs, can send or receive electrical signals from neurons and can be used for deep brain stimulation and other therapeutic interventions to treat disorders such as epilepsy, depression, and Parkinson’s disease. “Although current microelectrodes are simple 2-D needle arrays,” Daicho says, “our method can provide complex 3-D electrode arrays” in which the needles of a single device have different lengths and tip shapes, giving researchers more flexibility in designing electrodes for specialized purposes. The authors also envision making microscopic 3-D coils for heating applications.
Currently, researchers have access to materials that can be used to make complex 3-D structures. But the commercially available resins that work best with modern 3-D shaping techniques do not respond to carbonization, a necessary part of the electrode preparation process. In this stage, a structure is baked at a temperature high enough to turn its surface to carbon. The process of “carbonizing,” or charring, increases the conductivity of the resin and also increases its surface area, both of which make it a good electrode. Unfortunately, this process also destroys the resin’s shape; a sphere becomes an unrecognizable charred blob. What researchers needed were new materials that could be crafted using 3-D shaping techniques but that would also survive the charring process.
The Japanese team, led by Daicho and his advisor Shoji Maruo, sought to develop materials that would fit these needs. Trained as a chemist, Daicho developed a light-sensitive resin that included a material called Resorcinol Diglycidyl Ether (RDGE), typically used to dilute other resins but never before used in 3-D sculpting. The new mixture had a unique advantage over other compounds — it was a liquid, and therefore potentially suitable for manipulation using the preferred 3-D sculpting methods.
Daicho, Maruo, and colleagues tested three different concentrations of RDGE in their new compounds. Though there was shrinkage, the materials held their shapes during the charring process (controlled shrinkage of a microstructure can be a good thing in cases where miniaturization of a structure is desired). The resin with the lowest concentration of RDGE shrank 30 percent, while that with the highest concentration shrank 20 percent.
The researchers also tested their new resin’s ability to be manipulated using techniques specifically suited for 3-D shaping. In one technique, called microtransfer molding, the light-sensitive liquid was molded into a desired shape and then hardened by exposure to ultraviolet (UV) light. The other technique, preferred because of its versatility, made use of the liquid resin’s property of solidifying when exposed to a laser beam. In this process, called two-photon polymerization, researchers used the laser to “draw” a shape onto the liquid resin and build it up layer by layer. Once the objects were shaped, they were carbonized and viewed with a scanning electron microscope (SEM).
In addition to crafting pyramids and discs, the researchers reproduced the well-known “Stanford bunny,” a shape commonly used in 3-D modeling and computer graphics. Maruo says that when he first saw a picture of the rabbit structure taken with the SEM, he was delighted at how well it had held up during the charring process.
“When we got the carbon bunny structure, we were very surprised,” Maruo says. It was exciting, he continues, to see that “even with a very simple experimental structure, we could get this complicated 3-D carbon microstructure.” The rabbit’s shape would be much more difficult, expensive, and time-consuming to create using any of the existing processes compatible with carbonization, he adds.
Next steps for the team include fabricating usable carbon microstructures, as well as charring the resins at temperatures above the 800 degrees Celsius tested in this study. Moving to higher temperatures may destroy the microstructures, Maruo says, but there is a chance they will turn the surfaces into graphite, a higher-quality conductor than the carbonized surfaces they have created so far.Leggi il seguito
May 1, 2013 — A Boston University School of Medicine (BUSM) study shows a mind-body class elective for medical students helps increase their self-compassion and ability to manage thoughts and tasks more effectively. The study, published in Medical Education Online, also discusses how this innovative course may help medical students better manage stress and feel more empowered to use mind-body skills with their patients.
Allison Bond, MA, a third-year medical student at BUSM, served as the paper’s first author. The course was designed and taught by co-author Heather Mason, MA, founder and director of the Minded Institute.
“An effective career in medicine requires technical competence and expertise, but just as important is the ability to empathize and connect with others, including patients,” said Robert Saper, MD, MPH, director of integrative medicine at Boston Medical Center and associate professor of family medicine at BUSM. However, medical students experience tremendous demands from workload, stress and competition from other students to succeed, resulting in burnout and a decreased ability to connect with patients, according to studies.
“Research has shown that mindfulness meditation and yoga may increase psychological well-being, which is why we looked at how a course based on these principles could impact medical students,” said Bond.
The 11-week course, Embodied Health: Mind-Body Approaches to Well-Being, was open to first and second year medical students in good academic standing. It was developed to teach students about mind-body approaches, and the neuroscience behind the activities, that they might not otherwise learn in medical school but could use to help their patients achieve better overall health. Offered for the first time in Spring 2012, it met once weekly and included a 30 minute lecture about the neuroscience of yoga, relaxation and breathing exercises followed by a 60 minute yoga, deep breathing and mediation session. Each student was asked to practice the techniques (breathing, yoga, etc.) at least three times a week.
Participants filled out surveys before the course began and after it ended, and were asked about perceived empathy, perceived stress, self-regulation (ability to develop, implement and flexibly maintain planned behavior to achieve goals) and self-compassion. They also were asked to compose a one-page essay at the completion of the course to discuss if what they learned helped them personally and whether it influenced their ability to cope with stress or enhanced their sense of well-being.
Overall, responses indicate a statistically significant increase in self-regulation and self-compassion. There also was a decrease in perceived stress and an increase in empathy, although not statistically significant. The essays also indicate that the course helped many students:
feel more aware of their bodies,
feel a sense of community among their peers despite the competitive environment,
build confidence in using mind-body skills with patients and
better manage stress.
“Our study provides compelling evidence that mind-body approaches have benefits for medical students and could have a positive impact on their interaction with peers and patients,” said Bond.Leggi il seguito
Could depression and PMS really be culture-bound syndromes rather than biological entities? For sure, no one is arguing than they are not genuine illnesses ï¿½ to the patient, the symptoms are real and painful. I used to be …Leggi il seguito
Electrical engineering professor Claire Gmachl will succeed chemical and biological engineering professor Pablo Debenedetti as vice dean of the School of Engineering and Applied Science, the University announced …Leggi il seguito
"It also should raise awareness about potential harms of chemical contaminants in biologic agents used in warfare and the risks associated with waste handling and other chemical processes that generate dioxin or …Leggi il seguito
Learning Biology might be tough if you know the meaning of terminology. Jot down and take the help of an online science tutor. Biology tutoring uses flash cards describing each terminology with its definition, examples and …Leggi il seguito
In our latest science article Kalliopi Dodou and Paul Whiteley take a look at the study of the of small molecule metabolites found in biological fluids In our latest science article Kalliopi Dodou and Paul Whiteley take a look at …Leggi il seguito
NSTA, MIT Take Biology, Pedagogy Online. 4/13/2013 – NSTA Reportsï¿½Lynn Petrinjak. There's no excuse for anyone interested in science to echo Sam Cooke's classic lyrics, ï¿½don't know much biology, don't know much about a science book …Leggi il seguito
Steven L. Jacques. Depts. of Biomedical Engineering & Dermatology, Oregon Health & Science University. ï¿½Optically probing the nanoarchitecture of cells and tissues.ï¿½ Optical measurements are sensitive to structures on the …Leggi il seguito
“The purpose of science is not to cure us of a sense of mystery. The purpose of science is to constantly reinvent it.”The last 35 hours of lectures has shown me the fullLeggi il seguito
Un post di particolare interesse via: Videos matching: biology online: Learn 8th Std Science-Biology with Mahesh Tutorials Ink School OnlineLeggi il seguito