Discoveries Charging Forward Researchers at the University of Minnesota College of Biological Sciences have created a molecular image of the process by which electricity moves through cells, an achievement that could provide insights to minimizing energy loss in a wide range of systems, from the human body to electrical power grids. The image, obtained by using x-ray crystallography, provides a unique view of the extraordinary chemical process that enables human beings to exist by channeling energy to create complex molecules such as protein and DNA. One researcher with the National Institutes of Health likened the advance to being behind the stage at a magic show and seeing for the first time how a trick is performed. The research was published in the March 12 issue of Science.
Carbon Conundrum Planting new forests and restoring prairies may be beneficial for aesthetic and ecological reasons, but not enough idle land is available for conversion to significantly offset carbon dioxide emissions, according to a multidisciplinary study by University of Minnesota researchers. Plants take up carbon dioxide from the atmosphere to build leaf, stem, and root biomass, some of which is then transferred to soil, where it can reside for decades before eventually being broken down by soil organisms and returned to the atmosphere. Some policymakers and scientists view this process, known as carbon sequestration, as a possible way to combat global warming. However, the U study found that the potential to offset substantial emissions is constrained by a lack of available land. For example, if 10 percent of current cropland in the Upper Midwest were converted into a combination of new forests and grasslands, less than 5 percent of total carbon dioxide emissions for the region would be offset. Rather than convert land, however, researchers recommended implementing land use policies that protect current carbon stores, such as peatlands and wetlands. The study appeared online in the January issue of Frontiers in Ecology and the Environment. 12
S u m m e r 2 0 1 0 M I N N E S O TA
The more obese a person is, the higher his or her risk of stroke, regardless of race or gender and irrespective of whether obesity is measured by body mass index (BMI), waist circumference, or hipto-waist ratio. Those are key findings of a University of Minnesota Medical School study that followed 13,549 middle-aged black and white men and women in four U.S. communities from 1987 through 2005. The study also found that incidence of stroke differed substantially between blacks and whites. For example, black women were found to have three times higher incidence of stroke than white women in both the lowest and the highest weight categories. Previously, researchers had not established a clear correlation between overweight and obesity and stroke, especially among blacks. Likewise, scientists were uncertain about which measure of excess weight was most closely associated with disease risk. The study appeared in the January 21 online edition and in the March print issue of Stroke: Journal of the American Heart Association.
Go Where Thou Wilt The disease attacking your tomato plants this summer may have its origin in a fungus that migrated from a completely unrelated organism, according to a study by the University of Minnesota Department of Plant Pathology. The study, published in the March 18 online issue of Nature, found that fungi are more adaptable than previously thought and may “horizontally” transfer genes. The process, which was unknown prior to the study, is similar to the way bacteria quickly develop antibiotic resistance. Researchers made the discovery while studying three strains of Fusarium, a fungus that causes disease on various species of plants, including tomatoes. They found that Fusarium oxysporum, the strain that causes tomato wilt, is carried on special chromosomes that move easily between fungal strains. The process by which the chromosomes move is unknown.
CARBON CONUNDRUM ILLUSTRATION BY JOHN DAWSON/NATIONAL GEOGRAPHIC/GETTY IMAGES; OBESITY BY DANIEL BEJAR
No Matter What, Obesity Raises Stroke Risk