Virological evidence cannot prove transmission in HIV criminal cases, warn experts in this week’s BMJ.

Viral phylogenetics provides a way of assessing the relations between viruses from different people. It allows us to estimate the probability that viruses from two particular people have a recent common origin. But there are serious limitations on what can and cannot be inferred using this technique.

The recent flurry of criminal cases brought against people in the United Kingdom accused of infecting their sexual partner(s) with HIV has resulted in several convictions, write Professor Deenan Pillay and colleagues in an editorial.

Apes bite and try to break a tube to retrieve the food inside while children follow the experimenter's example to get inside the tube to retrieve the prize, showing that even before preschool, toddlers are more sophisticated in their social learning skills than their closest primate relatives, according to a new report.

This innate proficiency allows them to excel in both physical and social skills as they begin school and progress through life.

"We compared three species to determine which abilities and skills are distinctly human," explained Esther Herrmann of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany and lead author of the research paper.

Here are nine of the smallest, faintest, most compact galaxies ever observed in the distant universe. Blazing with the brilliance of millions of stars, each of the newly discovered galaxies is a hundred to a thousand times smaller than our Milky Way Galaxy.

"These are among the lowest mass galaxies ever directly observed in the early universe," says Nor Pirzkal of the Space Telescope Science Institute and the European Space Agency in Baltimore, Md.

The conventional model for galaxy evolution predicts that small galaxies in the early universe evolved into the massive galaxies of today by coalescing.

It’s well known that the child’s brain has a remarkable capacity for change, but controversy rages about the extent to which such plasticity exists in the adult human brain -- particularly, in the part responsible for vision.

Now, scientists from The Johns Hopkins University and MIT offer evidence -- derived from both brain imaging and behavioral studies -- that the adult visual cortex (the area of the brain that receives images from the eyes) does, indeed, have the ability to reorganize. Moreover, that reorganization affects visual perception.

A new study led by the University of Colorado at Boulder indicates biologists trying to save Colorado's native greenback cutthroat trout from extinction over the past several decades through hatchery propagation and restocking efforts have, in most cases, inadvertently restored the wrong fish.

According to a sophisticated DNA analysis, five of nine "relic" populations of what biologists believed to be greenback cutthroat trout living in isolated pockets of the state actually are Colorado River cutthroat trout, a closely related subspecies, said lead author Jessica Metcalf, a researcher in CU-Boulder's ecology and evolutionary biology department.

Physicists at the University of Michigan have coaxed two separate atoms to communicate with a sort of quantum intuition that Albert Einstein called "spooky."

In doing so, the researchers have made an advance toward super-fast quantum computing. The research could also be a building block for a quantum internet.

Scientists used light to establish what's called "entanglement" between two atoms, which were trapped a meter apart in separate enclosures (think of entangling like controlling the outcome of one coin flip with the outcome of a separate coin flip).