Anderson I.,University of Vermont |
ACI Materials Journal | Year: 2015
This laboratory study investigated the durability of pervious concrete containing fly ash to freezing and thawing and salt exposure in a field-representative environment. Pervious concrete was prepared by replacing cement with 0, 10, 20, and 30% fly ash. The specimens were subjected to one slow freezing-and-thawing cycle per day up to 100 days in a drained condition with sodium chloride solution with concentrations of 0, 2, 4, 8, and 12%. The void content, compressive strength, and hydraulic conductivity of the mixtures were all within the range of typical pervious concrete applications. Freezing-and-thawing testing suggested that for all concentrations of salt solution, 10 and 20% fly ash replacement improved freezing-and-thawing durability. Specimens with 30% fly ash showed more damage than that of the 0% control. The greatest damage from salt solutions was seen in 8%, 4%, and 2% concentrations, respectively. Water and 12% salt solution showed little damage across all mixture designs. © 2015, American Concrete Institute. All rights reserved.
In this Dec. 4, 2015 photo, books about marijuana lay on a table in the office of University of Vermont pharmacology professor Wolfgang Dostmann in Burlington, Vt. The College of Medicine is offering a new class on the science of medical marijuana. UVM is one of the first accredited academic programs in the country to offer a pharmacology class on medical cannabis. Professors said they are hampered by a lack of research on the topic. (AP Photo/Lisa Rathke) More BURLINGTON, Vt. (AP) — As more states allow for the use of medical marijuana, the University of Vermont is offering a course in the science of the drug — and the professors say they are challenged by a lack of research on what has long been a taboo topic. Other institutions have offered classes in marijuana law and policy, but the university's medical school is likely the country's first to offer a full course on medical cannabis, according to the Association of American Medical Colleges. Other medical schools have touched on the topic. "What we're trying to do with this course is to sort of demystify this whole subject matter, to try to treat this like any other drug, like alcohol or amphetamines or opioids," said Vermont pharmacology professor Wolfgang Dostmann. "Just demystify the whole thing and say what it is, what is going on with it, how does it work." Twenty three-states, including Vermont, allow the use of medical cannabis for a range of conditions or symptoms from glaucoma to HIV and cancer, although the drug is still illegal under federal law. The Massachusetts Medical Society, an accredited institution, is offering online medical marijuana courses including one on pharmacology, but it's also limited because of the lack of research on the topic. Medical cannabis is clearly a hot topic. Nearly 90 graduate and undergraduate students have signed up for the Vermont class, which is to start in the spring, forcing the professors to expand the classroom twice. The class is also open to the general public, allowing members of the Legislature, or those in law enforcement or medicine, to attend. Alice Peng, a pharmacology graduate student who plans to go medical school, signed up because she's interested in the potential for marijuana to treat pain. "I also do work in the cancer center in the hospital, and so I see a lot of cancer patients, and I would be really interested in seeing how it would help their chronic pain," she said. But the professors say they are hampered by a lack of access to high-quality research. "There's so much information out there that's just hearsay," said Vermont pharmacology professor Karen Lounsbury. The course will cover cannabis taxonomy; medical chemistry of cannabinoids, the chemicals found in marijuana; physiological effects of the drug; emerging therapeutic applications; and the historical, political and socioeconomic influences on marijuana legislation. Dostmann, whose expertise is in pharmacokinetics, or how a drug works in the body, and Lounsbury, who focuses on the body's physiological and biological response to a drug, will teach some of the course. Students will also benefit from what's happening with marijuana in Vermont. A university research affiliate and head of a Vermont medical marijuana dispensary will discuss the plant's biology. An associate business professor who is part of a Vermont think tank working to develop technology to research uses of medical marijuana products will talk about economic impacts. Students may also visit the Legislature, which is expected to discuss legalizing marijuana for recreational use. Books exist on the science of marijuana, but they also cover topics like how to clean pipes or cook with the plant, not what the university wants to teach students. So Lounsbury and Dostmann plan to write their own textbook for future studies. And if the class attracts stoners, the professors hope it will motivate them to study pharmacology. Above all, they hope they can raise awareness about a potentially useful drug. "Without having enough clinical trials," Lounsbury said, "we won't really know whether this is applicable or whether it is a snake oil." This story has been corrected to show the name of the organization is the Association of American Medical Colleges.
Manukyan N.,University of Vermont |
Eppstein M.J.,University of Vermont |
Proceedings of the 2013 International Conference on Collaboration Technologies and Systems, CTS 2013 | Year: 2013
Teams comprising diverse individuals have been shown to increase the collective creativity in jointly solving problems. However, in contexts where the purpose of collaboration is knowledge diffusion in complex environments, it is not clear whether team diversity will help or hinder effective learning. For example, in organized quality improvement collaboratives (QICs), healthcare institutions exchange information on clinical practices and outcomes with the aim of improving health outcomes at their own institutions. However, what works in one hospital may not work in others with different local contexts, due to non-linear interactions among various treatments and practices. While there is limited evidence that some QICs have resulted in improved care, it is not yet clear what factors contribute to the effectiveness of these team collaborations. In this study, we use an agent-based model to study how different strategies of team formation, including team diversity and size, affect quality improvement in simulated collaborative environments. We show that, in this context, teams comprising similar individuals outperform those with more diverse teams, and that this advantage increases with the complexity of the landscape and level of noise in assessing fitness. Furthermore, we show that larger teams of relatively homogeneous agents perform better than smaller teams, and that effective learning through team collaborations is dependent on the level of knowledge of team members' performance levels. Thus, our results suggest that groups of similar hospitals should collaborate as a single team and openly share detailed information regarding their clinical practices and outcomes. To facilitate this, we propose a virtual collaboration framework that would allow hospitals to efficiently identify potentially better practices in use at other institutions similar to theirs, without any institutions having to sacrifice the privacy of their own data. Our results may also have implications for other types of data-driven diffusive learning, such as in personalized medicine. © 2013 IEEE.
Vargas S.,National Autonomous University of Mexico |
Estevez M.,National Autonomous University of Mexico |
Hernandez-Martinez A.R.,National Autonomous University of Mexico |
Rangel D.,National Autonomous University of Mexico |
And 2 more authors.
International Journal of Food Science and Technology | Year: 2012
Using dielectric measurements, it was possible to determine the concentration of bio- and free-calcium in a corn dough prepared mixing commercial powder of alkaline-cooked ground-corn kernel (maize), Zea mays, with different concentrations of Ca(OH) 2 and the same amount of water. This allows determining the conditions to obtain dough with high bio-calcium content and consequently high nutritional value. The samples were placed in the interior of a small parallel-plate capacitor. The capacitance and the cell current profiles were obtained with the corresponding relaxation times as a function of the Ca concentration. With this information, it was possible to determine the threshold concentration at which the Ca ions are not longer linked chemically to the cornstarch molecules and move freely in the interior of the dough. A model based on the ionic conductivity was developed to explain the dependence of the relaxation times with the Ca concentration. © 2012 The Authors. International Journal of Food Science and Technology © 2012 Institute of Food Science and Technology.
The new study finds that if losses of wild bees continue, United States crop production could be destabilized. We've said it again and again, so excuse me for saying it again, but the bees are in trouble and we have to do something. While every species plays a role in the ecosystem, we are directly reliant on bees for pollinating the plants that feed us. But while most of the focus has been on commercial honeybees, our wild apian friends are in trouble too. With that knowledge in hand, a team of researchers created the first national study to map U.S. wild bees. What they found confirms that our native buzzing pollinators are disappearing from many of the country's most vital farmlands, from California's Central Valley and the Midwest corn belt to the Mississippi River valley. © PNAS"If losses of these crucial pollinators continue, the new nationwide assessment indicates that farmers will face increasing costs – and that the problem may even destabilize the nation's crop production," notes the study, the findings of which were published in the Proceedings of the National Academy of Sciences. Led by Insu Koh, the scientists estimate that wild bee abundance between 2008 and 2013 declined in almost one-quarter of the contiguous U.S. In addition 39 percent of U.S. croplands that rely on pollinators face a potentially debilitating mismatch between increasing demand for pollination and a diminishing supply of wild bees. "Until this study, we didn't have a national mapped picture about the status of wild bees and their impacts on pollination," says Koh, a researcher at UVM's Gund Institute for Ecological Economics. The report calls for seven million acres of land to be protected as pollinator habitat over the next five years. "It's clear that pollinators are in trouble," says Taylor Ricketts, the senior author of the study and director of UVM's Gund Institute. "But what's been less clear is where they are in the most trouble – and where their decline will have the most consequence for farms and food." © PNASThe map shows 139 counties in key agricultural regions of California, the Pacific Northwest, the upper Midwest and Great Plains, west Texas, and the southern Mississippi River valley that appear to be most threatened by the mismatch between decreasing wild bee supply and increasing crop pollination demand. In particular, the study found that crops like pumpkins, watermelons, pears, peaches, plums, apples and blueberries which are most reliant on pollinators have the strongest pollination mismatch. "These are the crops most likely to run into pollination trouble," says Taylor Ricketts, Gund Professor in UVM's Rubenstein School of Environment and Natural Resources. "whether that's increased costs for managed pollinators, or even destabilized yields." We've known for a while the culprits at play in the fate of wild bees – pesticides, climate change, and diseases. But the new research also suggests that turning bee habitat into cropland is to blame as well. In 11 key states where bee numbers are falling, the amount of land tilled to grow corn skyrocketed by a whopping 200 percent in five years. Former bee havens are now reserved for raising corn. "These results reinforce recent evidence that increased demand for corn in biofuel production has intensified threats to natural habitats in corn-growing regions," the new study notes. "Wild bees are a precious natural resource we should celebrate and protect," says Ricketts. "If managed with care, they can help us continue to produce billions of dollars in agricultural income and a wonderful diversity of nutritious food." "Now we have a map of the hotspots," adds Koh. "It's the first spatial portrait of pollinator status and impacts in the U.S." The researchers hope the new tool will help protect wild bees and pinpoint habitat restoration efforts. See all the data and maps at the University of Vermont website.