Dust in the Solar Wind: The first infrared images of the Crab Nebula turned up a bit of a surprise when studied by U of M astronomers: The expected cosmic dust was missing. The Crab Nebula is the remains of a supernova—a star that ran out of fuel, collapsed, and exploded—first visible from Earth in the year 1054. It ejected huge amounts of gas and dust, including super-fine cosmic dust, which is visible in a more recent supernova, first detected in 1987. The finest dust particles are now missing, possibly vaporized by intense ultraviolet radiation or destroyed by speeding protons and electrons. Researchers are looking at energy patterns in the nebula to hypothesize about the dust, which in turn may lead to new ideas about how elements ejected from supernovas become new stars and planets. The images come from the Spitzer Space Telescope, a unique device following the Earth’s orbit by a million miles. Operated by Cal Tech’s Jet Propulsion Laboratory, Spitzer is open to outside researchers for specific projects.

In a breakthrough that made news coast-to-coast, University of Minnesota researchers reversedmemory loss in mice genetically engineered to suffer brain atrophy similar to that caused by Alzheimer’s disease. The findings raise the hope that the same can someday be done for humans and also challenge assumptions about how the disease develops.

Led by Dr. Karen Hsiao Ashe, who created the “Alzheimer’s mice” almost a decade ago, researchers first isolated the gene that apparently causes brain degeneration and memory loss in Alzheimer’s. But after “switching off” that gene in Alzheimer’s mice and putting them through a maze, researchers found that memory loss in the animals hadn’t simply halted, their memory had significantly recovered. Further, this recovery occurred even though tangles of proteins within brain cells, believed to be one of the primary causes of memory loss, remained intact. Now, researchers believe the tangles might be a protective reaction to the disease.”

Ashe, who holds the Edmund Wallace and Anne Marie Tulloch chairs in Neurology and Neuroscience, is now working to identify and understand the proteins that set off the tangle reaction, hoping to find treatments that could reverse some Alzheimer’srelated memory loss. Similar work is already under way on the proteins that cause plaque buildup between brain cells, believed to be the other major cause of memory loss.

The results were published in the July 15 issue of the journal Science.

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A STEP TOWARD BLOCKING HIV
Finding ways to block HIV transmission will be easier thanks to new U of M research. For the first time, HIV was successfully transmitted into human tissue in a lab setting. Previous studies have used monkeys or monkey tissue to study transmission, and finding ways to recreate sexual transmission in human tissue has proven technically difficult. But U researchers successfully introduced HIV cells to tissue from female reproductive tracts under microscopes and observed the HIV binding to the tissue and rapidly invading and infecting it. This suggests that discovering methods to block the HIV cells from binding may be a key to preventing male-to-female sexual transmission, which is now the fastest-growing category of new HIV infections. Read the full Academic Health Center news release.

NATURAL LEADERS
Add leadership to the list of personality traits now linked to genetics. U researchers surveyed 325 pairs of twins on subjects such as the leadership roles they have played over the years and their desire to influence others, be the center of attention, persist when others give up, and be with other people. By comparing answers given by identical twins and fraternal twins (who share only half of their inherited genes), they concluded that about 30 percent of leadership is genetic, a small but significant percentage. Study leaders say the next steps are to evaluate what environmental factors play roles in creating leaders. Read more about this study here.

DETECTING BREAST CANCER
Magnetic resonance imaging catches almost all breast tumors, but only magnetic resonance spectroscopy can accurately distinguish benign tumors from malignant ones, a U study has found. The spectroscopy methods, which add 7 to 10 minutes to the imaging procedure, enable radiologists to distinguish chemical compounds in the tissue. In the study, four radiologists studied magnetic resonance evidence from 55 breast cancer cases where diagnosis had been confirmed by biopsies. When spectroscopic readings were included, they more often detected cancerous tumors and had greater agreement on the findings. Researchers urge the use of spectroscopic readings whenever standard imaging is inconclusive. Related research article. More on breast cancer advances.

CHEATING OPTIONS
Stock options do not drive executives to do better. Rather, according to a U study, they drive them to cheat. A doctoral student and a professor of management compared 435 companies that were forced to restate and lower reported profits with similar companies that did not run into such problems. The study found that the higher the proportion of executive pay that was in stock options the more likely the company was to overstate profits. The study also found that companies with such accounting problems were more likely to be those that were doing worse than competitors, as well as those that posted a very good year the year before.

ANEMIA AND HEART FAILURE
Anemia—low blood hemoglobin caused by poor iron stores—greatly increases the risk of complication and death in heart failure patients. Between one-quarter and one-half of heart failure patients suffer from anemia. Patients with healthy hemoglobin levels had a 21 percent lower death rate in the first year after heart failure, while those whose hemoglobin increased after heart failure had a 22 percent lower death rate. Patients whose hemoglobin levels dropped to anemic levels after heart failure experienced 47 percent more hospitalizations. Anemia can be treated with supplements, though researchers caution that it is not clear whether anemia causes the increase in complications or if the most severe heart failure causes the anemia.