Vampire bat study may lead to better rabies-control strategies
A new study of rabies in vampire bats in Peru has found that culling bats — a common rabies control strategy — does not reduce rates of rabies exposure in bat colonies, and may even be counterproductive.
The findings may eventually help public health and agriculture officials in Peru develop more effective methods for preventing rabies infections in humans and livestock, according to a team of scientists from the United States and Peru led by Daniel Streicker, a postdoctoral associate at the University of Georgia Odum School of Ecology.
Photo by Oscar Centty, National University of San Marcos.
The study was published online in the Proceedings of the Royal Society B. The research team includes U-M population ecologist Pejman Rohani.
“Our paper represents a significant move forward in the study of an important class of infectious diseases in a setting where the economic impact on livestock and the burden on humans is substantial,” says Rohani, a professor of ecology and evolutionary biology, a professor of complex systems and a professor of epidemiology at the School of Public Health.
Rabies is a serious problem in South America. Human deaths are increasingly recognized in the Amazon rainforest, and cattle die from the disease each year by the thousands. While rabies is present in most bat populations in South America, vampire bats — the only bat species that feed on mammals’ blood — are responsible for the majority of human and livestock infections. The encroachment of cattle farming and human settlements into areas with existing vampire bat populations has only exacerbated the problem.
Since the 1970s, efforts to control the spread of rabies in Peru have focused on culling vampire bats using poison or even explosives, on the assumption that if the size of the bat colony could be reduced enough, rabies virus would die out in that colony.
— Beth Gavrilles, University of Georgia
Hospitals’ communication in residency matching may stress doctors-in-training
Many hospitals offer residency programs for doctors in training, allowing them to complete the education needed to become practicing physicians. Hospitals find those residents using National Residency Matching Program (NRMP) rules, but a new study finds wide variation in the interpretation of those rules.
The NRMP rules are intended to minimize pressure on residency candidates, says lead author Dr. Diana S. Curran, residency program director for the Department of Obstetrics and Gynecology. But her study, published in the Journal of Graduate Medical Education, found that the rules may instead be leading to stress for both OB-GYN residents and program directors.
The results suggest that programs may be communicating their match intentions, especially to favored candidates. Curran and her co-authors surveyed OB-GYN residency program directors across the United States in an online survey.
The majority of respondents (76.6 percent) reported that their programs initiated contact with residency candidates after interviewing them either all of the time (28.7 percent), most of the time (21.3 percent) or sometimes (26.6 percent). Only 23.4 percent reported never initiating post-interview contact with candidates.
Eighty-four percent of the program directors reported that candidates asked about their ranking status after the interview, with 1.1 percent reporting that they informed the candidate about his/her chance and 16.0 percent reporting that they provide a vague answer to candidate inquiries. Sixty-percent of programs informed inquiring candidates that their rank could not be revealed, however 51.5 percent also reported that highly desirable candidates might be contacted to inform them they were ranked to match.
Curran and her co-authors say adherence to NRMP rules are crucial in the very stressful match process.
Additional authors, all of the Department of Obstetrics and Gynecology: Pamela B. Andreatta, Dr. Clark E. Nugent, Samantha R. Dewald and Dr. Timothy R.B. Johnson.
— Mary Masson, UMHS Public Relations
Satiric news decreases bias against Arab-Americans and Al Jazeera
Satiric news coverage — a format seen on programs such as “The Daily Show with Jon Stewart” — decreases Arab American prejudice and bias against Al Jazeera English.
A new U-M study finds that Americans can change their views about Al Jazeera English, a global news network, depending on how it is covered by other media.
AJE has not been welcomed in the United States, in part, because many people associate it with Al Qaeda and other American adversaries. Many Americans presume the network is biased and driven by an anti-American agenda.
Katie Brown and William Youmans, the study’s authors and doctoral candidates in the Department of Communication Studies, say their research shows that the bias against AJE correlates with prejudice against Arab Americans. In an online experiment, both bias and prejudice decrease among viewers of lighter, comedic news programming.
“It seems a one-two punch of a satiric soft news framing of the network and actual exposure to AJE can together overcome antipathy toward AJE,” the researchers say.
How other media frame AJE may help its entry into the U.S. market, they suggested.
Satirical shows skewering the mainstream’s portrayal of AJE as a platform for terrorism also can change some Americans’ views toward Arab-Americans.
“Given the increased discrimination against Arab-Americans in the wake of the war on terror, this suggests satire can decrease prejudice,” Brown says.
The findings appear in the current issue of Journal of Intercultural Communication Research.
— Jared Wadley, News Service
Why do fat cells get fat? U-M findings point a plump finger at a new suspect
As the world fights obesity at the human level, scientists at U-M and their colleagues have made a surprising finding at the microscopic level that could help fuel that fight.
Their work helps explain why fat-storing cells get fatter, and burn fat slower, as obesity sets in. If their findings from mice can be shown to apply to humans, they may provide a new target for obesity-fighting drugs.
By studying the tiny signals that fat-storing cells send to one another, the team has shown a crucial and previously unknown role for a molecule called Sfrp5.
The results, which appear online and will be in the July issue of the Journal of Clinical Investigation, surprised them.
In a series of experiments, the team showed that Sfrp5 influences a signaling pathway known as WNT to stimulate fat cells — called adipocytes — to grow larger and to suppress the rate at which fat is burned in the mitochondria inside them.
By stopping cells from making Sfrp5, they were able to make mice that didn’t get as fat as quickly because their adipocytes didn’t grow large — even when the mice were fed a high-fat diet. They even showed the impact when transplanting fat from Sfrp5 — deficient mice into other mice.
The research was performed in the Medical School laboratory of Ormond MacDougald, the Faulkner Collegiate Professor of Physiology, a professor of internal medicine, professor of molecular and integrative physiology, and a member of the Brehm Center for Diabetes Research.
Working with postdoctoral fellow and first author Dr. Hiroyuki Mori, and colleagues, MacDougald says the team built on its previous findings about the importance of WNT signaling in fat cell development.
While pharmaceutical companies are already looking at WNT signaling as a possible target for drugs related to bone formation, the new findings suggest that perhaps the same signaling pathway could be a target for anti-obesity drugs.
— Kara Gavin, UMHS Public Relations
Lab-on-a-chip detects trace levels of toxic vapors in homes near Utah air base
A lab-on-a-chip technology that measures trace amounts of air contaminants in homes was successfully field-tested by researchers at U-M.
Even in the presence of 50 other indoor air contaminants, the U-M-built microsystem found levels of the targeted contaminant so low that it would be analogous to finding a particular silver dollar in a roll stretching from Detroit to Salt Lake City.
“This is the first (known) study of its kind,” says Ted Zellers, professor in the School of Public Health and the Department of Chemistry, LSA, and project director.
“Most lab-on-a-chip technologies are used for biomedical analysis of liquids,” Zellers says. “Our technology is designed for monitoring contaminants in the air, and this groundbreaking study is the first to prove that it can work outside the laboratory in real-life applications.”
The applications are potentially limitless because the device, called a microfabricated gas chromatograph, can be tailored to detect any contaminants, Zellers says. For instance, the team is adapting the same technology to detect certain industrial chemicals in the breath and saliva of exposed workers, biomarkers of cancer and other chronic disease, and markers of explosives for airport screening applications.
The Department of Defense contracted the U-M team to adapt and test two prototypes devices in homes near Utah’s Hill Air Force Base to measure indoor concentrations of trichloroethylene, or TCE. TCE was used on military bases until the 1970s, and improper disposal caused TCE to become a pervasive groundwater contaminant that can seep into homes above plumes.
A series of articles describing the results appears in the journal Environmental Science & Technology.
Additional U-M authors are Sun Kyu Kim, Hungwei Chang and Jonathan Bryant-Genevier.
— Laura Bailey, News Service
