Gaseous ring around young star raises questions

Astronomers have detected a mysterious ring of carbon monoxide gas around the young star V1052 Cen, which is about 700 light years away in the southern constellation Centaurus.

The ring is part of the star’s planet-forming disk, and it’s as far from V1052 Cen as Earth is from the sun. Discovered with the European Southern Observatory’s Very Large Telescope, its edges are uniquely crisp.

Carbon monoxide often is detected near young stars, but the gas usually is spread through the planet-forming disk. What’s different about this ring is that it is shaped more like a rope than a dinner plate, says Charles Cowley, professor emeritus of astronomy, LSA, who led the international research effort.

“It’s exciting because this is the most constrained ring we’ve ever seen, and it requires an explanation,” Cowley says. “At present time, we just don’t understand what makes it a rope rather than a dish.”

Perhaps magnetic fields hold it in place, the researchers say. Maybe “shepherding planets” are reining it in like several of Saturn’s moons control certain planetary rings.

“What makes this star so special is its very strong magnetic field and the fact that it rotates extremely slow compared to other stars of the same type,” says Swetlana Hubrig, of the Leibniz Institute for Astrophysics Potsdam, Germany.

The star’s unique properties first caught the researchers’ attention in 2008, and they have been studying it intensely ever since.

Understanding the interaction between central stars, their magnetic fields and planet-forming disks is crucial for astronomers to reconstruct the solar system’s history. It also is important to account for the diversity of the known planetary systems beyond our own.

The findings are newly published online in Astronomy and Astrophysics.

— Nicole Casal Moore , News Service

Drug use, lack of parent involvement led some teens to carry handguns

Teens who carry handguns often do not have a parent involved in their lives and likely use drugs, a new study reports.

“Youth handgun carrying is a powerful driver of youth violence and injury in the United States,” says Brian Perron, associate professor of social work at the School of Social Work, noting that a better understanding of this phenomenon is important to inform youth violence policy and prevention efforts.

Using data from the National Survey on Drug Use and Health, the study examined teen behavior, parental involvement and prevention. In a sample of 17,842 teens nationwide between the ages of 12 and 17 about 3 percent of them reported carrying a handgun in the past year.

Those who carried guns were more likely to be male and to have been in jail, the study found.

In addition, delinquent behaviors — such as attacking someone, selling drugs or stealing more than $50 — also increased the odds of carrying a handgun.

The strongest factor contributing to gun possession involved a lack of parental involvement. If a parent told the teen they had done a good job in the last year or that they were proud of what they had done, the teens were less likely to carry the gun, researchers say.

But the ability for parents to spend more time with their children, which would have significant benefits, isn’t always possible. Perron says economic stresses on families might heighten the probability of teens selling drugs, which increases the need for greater self-protection and hence handgun carrying.

The findings appear in the current issue of Journal of Interpersonal Violence.

— Jared Wadley, News Service

Gene linked to pancreatic cancer growth, U-M study finds

A mutant protein found in nearly all pancreatic cancers plays a role not only in the cancer’s development but in its continued growth, according to a new study from Comprehensive Cancer Center researchers. The finding suggests a possible target for developing new ways to treat this deadly disease.

Researchers have known that mutations in the Kras gene are what cause pancreatic cancer to develop. These mutations frequently are seen in common precancerous lesions, suggesting it has an early role in pancreatic cancer.

The new study, published in the February Journal of Clinical Investigation, finds that in mice, mutant Kras also keeps the tumor growing and helps precancerous tumors grow into invasive cancer. When the researchers turned off Kras, the tumors disappeared and showed no signs of recurring.

The researchers were able to manipulate Kras in a mouse model that they designed to look at Kras at various points in pancreatic cancer development. In the precancerous lesions, turning off Kras eliminated the tumors in mice and the pancreas tissue returned to normal, with no signs of the cancer returning. With invasive cancer, inactivating Kras killed off the cancer but left the pancreas with fibrous areas similar to scar tissue. Tumors did not recur.

Researchers hope this finding provides the basis for future drug development.

“Right now no drugs specifically target Kras, but there are drugs that target the cellular processes downstream of Kras. We next need to figure out which of these downstream effectors of Kras are important in pancreatic cancer,” says study author Marina Pasca di Magliano, assistant professor of surgery and of cell and developmental biology at the Medical School.

Additional U-M authors are Meredith Collins, Filip Bednar, Yaqing Zhang, Jean-Christophe Brisset, Stefanie Galban, Craig Galban, Sabita Rakshit, and Karen Flannagan.

— Nicole Fawcett, Comprehensive Cancer Center

Companies transforming social networks to social dollars

Companies are fast adapting marketing strategies to leverage social media since Americans now spend more of their online time engaged in virtual networks than in any other activity.

New research from Stephen M. Ross School of Business marketing professor Puneet Manchanda suggests a significant payoff for companies that set up their own online communities. Using data from an unnamed retailer of books, CDs and DVDs, Manchanda found a 19 percent bump in incremental revenue from customers after they joined the online community. He calls this revenue “social dollars.”

His paper, “Social Dollars: The Economic Impact of Consumer Participation in a Firm-Sponsored Online Community,” also shows this spending persists over time, well after the novelty of joining the network wears off, and doesn’t cannibalize between channels. In this case, the company sells products both online and in stores, and network members spent more in both. The spending increase came via more frequent purchases, rather than bigger receipts.

This monetary reward is in addition to the benefits of a hosted social online community, such as customer engagement and the ability to better target promotions.

The study is one of the first to examine empirical evidence of social network outcomes.

“Most of the research on the effectiveness of social networks is based on self-reported data,” says Manchanda, the Isadore and Leon Winkelman Professor of Marketing. “There’s little actual evidence people change their behavior once they join an online community in terms of actual outcomes. So we wanted to see if we could find these social dollars and our research confirmed their existence. We stress-tested the findings in multiple ways because the results surprised us at first.”

Manchanda’s co-authors are Ross School doctoral candidates Grant Packard and Adithya Pattabhiramaiah.

— Terry Kosdrosky, Stephen M. Ross School of Business

Increased reliance on newer ocular imaging technologies may undermine patient care

Over the past decade, ophthalmologists and optometrists have turned to a range of newer technologies — beyond visual field testing and straightforward fundus photography — to evaluate patients with and suspected of having open-angle glaucoma.

But a new study published in the January issue of Ophthalmology reports that increased reliance on these newer technologies as a replacement for the more traditional visual field testing and fundus photography may undermine patient care.

The investigation focused on trends in eye care provider use of three methods for evaluating patients with open-angle glaucoma or suspected glaucoma: visual field testing, fundus photography, and other ocular imaging technologies.

Among these newer imaging technologies, the three most commonly relied upon approaches are confocal scanning laser ophthalmoscopy (CSLO), scanning laser polarimetry (SLP), and optical coherence tomography (OCT) — all of which evaluate the optic nerve or retinal nerve fiber layer tissue, the structures in the back of the eye which can be damaged by glaucoma.

“Over the past decade, we found a substantial increase in the use of newer ocular imaging devices and a dramatic decrease in the use of visual field testing in the management of patients with and suspected of having open-angle glaucoma by ophthalmologists and optometrists,” says Dr. Joshua D. Stein, a glaucoma specialist at the W.K. Kellogg Eye Center who reported the findings.

“Until these newer imaging devices can be demonstrated to identify the presence of open-angle glaucoma and capture disease progression as well as more traditional methods do, providers should use these devices as an adjunct to — not a replacement for — visual field testing and fundus photography.”

Additional U-M authors are Nidhi Talwar, Alejandra LaVerne, Bin Nan and Dr. Paul Lichter.

— Barbara Sefton, Ophthalmology & Visual Science

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