Brockhaus and Efron Encyclopedia Dictionary

Brockhaus and Efron Encyclopedia Dictionary

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Due to fluctuations in the weather over the past 50,000 years—as well as the arrival of modern humans—many large North American mammals, from giant beavers to woolly mammoths, became extinct. But there was such a wealth of species then that the extinctions didn’t harm the ecosystem as much as scientists have thought. An analysis by geophysicist Matt Davis ’16PhD shows that the “functional diversity” (the range of roles species play in an ecosystem) dropped about 40 percent, but survivors picked up some of the slack. But today, there’s much less redundancy in our ecosystems. “Future extinctions will cause even more rapid drops in functional richness,” Davis notes: we could lose half of our functional diversity if just a handful of the species now at risk are lost. The work appeared in Proceedings of the Royal Society B.


There may be new hope for the roughly one in twenty women of childbearing age whose pregnancies repeatedly end in miscarriage. In Fertility and Sterility, Harvey J. Kliman, who directs the Medical School’s Reproductive and Placental Research Unit, and his colleagues reported on a group of high-risk women who used vaginal supplements of the hormone progesterone, both before pregnancy and during the first ten weeks of gestation. The women were significantly more likely—68 percent versus 51 percent—to carry a fetus to term than those who didn’t use progesterone. Scientists believe the progesterone helps the endometrial lining of the uterus to nourish the developing embryo.


One way the Affordable Care Act was designed to lower medical costs was through a provision known as the Hospital Readmission Reduction Program. Beginning in 2012, the HRRP slapped significant financial penalties on a subset of the country’s hospitals—those whose readmission rates for Medicare patients with heart attacks, heart failure, or pneumonia exceeded the national average. According to an impact study led by Yale cardiologist Nihar R. Desai, the approach seems to be working. Desai’s team, writing in the Journal of the American Medical Association, noted that while readmission rates have declined across the nation, those at hospitals facing the financial hit dropped the most.

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