Social status has impact on mammals’ overall health pic
High social status has its privileges when it comes to aging – even in wild animals.
In a first-of-its-kind study involving a wild species, Michigan State University researchers have shown that social and ecological factors affect animal health. The results, published in Biology Letters, focused on spotted hyenas in Kenya.
“High-ranking members in hyena clans reproduce more, they live longer and appear to be in better overall health,” said Nora Lewin, MSU doctoral student of zoology and co-lead author. “If you want to see the hierarchy of spotted hyenas, throw down some fresh meat near them. It’s quickly apparent who’s dominant and who’s not.”
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Lewin and her teammates focused on telomeres, caps at the end of each strand of DNA that protect chromosomes from deterioration. These biomarkers are regarded as important signs of aging and stress in many species, including humans. Shrinking telomeres are a signal that cells are sliding into defensive mode, stressful actions that could soon lead to cell – and to the organism’s – death. High-ranking hyenas had longer telomeres than their subordinates. msu.edu
Duke study questions current statin guidelines
The newest guidelines for the use of cholesterol-lowering statins in people at risk of heart disease may be too generic – excluding middle-aged adults who could benefit from the drugs, and over-prescribing in older adults – according to a new study from the Duke University Medical Center’s Clinical Research Institute.
But small adjustments to guidelines could enable doctors to catch more people between the ages of 40 and 55 with premature heart disease and prevent them from prescribing unnecessary medications for many adults older than 65, according to the analysis published this month in the Journal of the American College of Cardiology.
Duke biostatistician Michael Pencina, a senior author of the paper, said: “We were interested in how tailoring the guidelines could get beneficial treatment to those who really need it, and avoid over-treating patients whose risk may only be their sex and age.”
The statin guidelines have been debated since the American Heart Association and American College of Cardiology issued them in 2013, resulting in about 13 million new people being recommended for treatment, including most adults older than 60. dukemednews.org
Researcher track slave origins through teeth found buried
Researchers have analyzed the DNA of ancient teeth to identify the regional origin of three African slaves buried more than 300 years ago on a former Dutch colony in the Caribbean.
The development could open the door to broadening the understanding of African-American ancestry linked to the European trade in slaves, which often is limited by scant historical record-keeping and incomplete genome and population data, according to the study published online Monday in the journal Proceedings of the National Academy of Sciences.
“I like to think of DNA as another type of archive, another type of record that we can use in order to understand the past,” said the study’s lead author, Hannes Schroeder, an archaeologist who studies ancient DNA at the Natural History Museum of Denmark.
When they were unearthed accidentally in 2010 during the construction of an office complex, the three skeletons in the Zoutsteeg area of Philipsburg, on the Dutch side of St. Martin, offered strong clues that they had not been born there.
The two men and one woman, ages 25 to 40, probably died between 1660 and 1680, when St. Martin was ruled by the French and Dutch. Although archives of the slave trade have expanded greatly, they mention only one docking at St. Martin in the last half of the 17th century, and do not list even the port of embarkation, let alone the origin of the slaves themselves.
“There is a lot of information in there, but when it comes to trying to pinpoint ethnic origins, there are no records telling you where a particular individual comes from,” Schroeder said.
Since the publication five years ago of the first ancient genome, researchers have begun shifting focus to relatively recent DNA in areas where little data have been published, including Africa and the Americas. Los Angeles Times