The odds of being attacked and castrated by a variety of parasitic flatworms increases for marine horn snails the farther they are found from the tropics. A Smithsonian-led research team discovered this exception to an otherwise globally observed pattern -- usually biodiversity is greatest in the tropics and decreases toward the poles.

Pygmy sloths wander inland in addition to inhabiting the mangrove fringes of their island refuge. A Smithsonian visiting scientist realized that the population size of the pygmy sloth was underestimated; a new, higher estimate for the number of sloths on Panama's Escudo de Veraguas Island points to how little is known about the species, and it underscores the need to conserve the sloths' isolated home.

A nanobiosensor for the early diagnosis of certain types of cancer, as well as nervous system diseases such as multiple sclerosis and neuromyelitis optica, was developed by researches in São Paulo State, Brazil. The nanometric sensor is capable of identifying biomarkers of these pathological conditions. An article about the nanobiosensor has just been published as a cover feature by IEEE Sensors Journal.

Olive baboon troops decide where to move democratically, despite their hierarchical social order, according to a new report in Science magazine by Smithsonian researchers and colleagues. At the Mpala Research Centre in Kenya, the team conducted the first-ever group-level GPS tracking study of primates, finding that any individual baboon can contribute to a troop's collective movement.

Animals wearing new tagging and tracking devices give a real-time look at their behavior and at the environmental health of the planet, say research associates at the Smithsonian Tropical Research Institute in the June 12 issue of Science magazine.

Researchers working at the Institut Pasteur in Montevideo (member of the Institut Pasteur International Network), in collaboration with the Uruguayan Medical School, obtained for the first time ever high-resolution images of the Bovine Leukemia Virus (BLV) capsid protein. Their images reveal unprecedented elements of flexibility in this protein, which are key for the assembly of the infectious particle. These findings, reported today in Science, represent a major progress in understanding retrovirus biology, opening new avenues towards the development of antiretroviral therapies.

Scientists raised the estimated number of tropical tree species to at least 40,000 to 53,000, the Smithsonian reports. Many tropical tree species risk extinction because of their rarity and restriction to small geographic areas, reaffirming the need for comprehensive, pan-tropical conservation efforts.