Nature reserves and national parks play a crucial role in sheltering wildlife, such as African elephants, from hunting and habitat destruction, but they have no problem at all exhausting the wildlife around them.

Researchers have examined the effect elephants have on the woody plant life in Kruger National Park, the largest protected area in South Africa, and found that elephants are the preserve's leading causes of fallen trees.

Scientists call them toxins but these bacterial proteins don't poison us, at least not directly. Instead, they restrain the growth of the bacteria that make them, establishing a dormant "persister cell" state that is tolerant to antibiotics.

Researchers at Emory University School of Medicine have obtained precise pictures showing how a toxin protein, called HigB, recognizes and rips up RNA as part of its growth-inhibition function. Their findings could lead to a better understanding of the formation of persister cells and how they maintain themselves.

Citations are a time-honored measure now used to assess scholarly standing and evaluate academic productivity by funding committees that control government research.

For that reason, citations that are critical in nature, and point out limitations, inconsistencies or flaws in previous work, can be detrimental. A new paper in Proceedings of the National Academy of Sciences finds that negative citations were more likely to criticize highly-read papers, they tended to originate from scholars who were close to the authors of the original articles in academic discipline and social distance - but at least 150 miles away geographically. 

Samples of permafrost soil are providing new ways to anticipate what may happen if northern regions of the world warm and begin to thaw.

Florida State University doctoral student Travis Drake and Florida State University Assistant Professor Robert Spencer write in a new paper that permafrost organic material is so biodegradable that as soon as it thaws, the carbon is almost immediately consumed by single-cell organisms called microbes and then released back into the air as carbon dioxide, feeding the global climate cycle. Their findings are laid out in an article published today by the Proceedings of National Academy of Sciences.

Many transgender people who want to bear children are faced with barriers in the healthcare system, argue Juno Obedin-Maliver and Harvey Makadon in a commentary published in SAGE journal Obstetric Medicine.

Husbands and wives married for a long time don't look at marital problems in the same way. When a marriage has troubles, women worry and become sad and they get frustrated. For men, it's frustration and not much more.

In a new sociology survey published in the Journal of Gerontology: Social Sciences, worry and frustration were among the most common negative emotions reported by older adults but men and women in long-term marriages deal with marriage difficulties differently.