There is a heated national debate about gun control.

Two mathematicians have designed parameters they say can help best prevent both one-on-one killings and mass shootings in the United States. Their findings, that properly-enforced gun laws will help, are not new. Like hockey, 'enforce the rules we already have' would seem to apply to guns. Instead, the cultural focus is on 'assault weapons', a tiny fraction of gun homicides, while ignoring the psychiatric common denominator and that the overwhelming number of gun deaths are suicides - not mass shootings.  Shooting sprees happen just as often in European countries where guns are banned as they happen in the US. 

X chromosomes are special, even for genetic material. They differ in number between men and women and to achieve equality between sexes, one out of two X chromosomes in women is silenced.

In Drosophila, the opposite happens: in male flies, the only available X chromosome is highly activated, to compensate for the absence of the second X-chromosome.

A "structure-based" approach to drug design has led to identification of compounds with the potential to delay or treat Alzheimer's disease, and possibly Parkinson's, Lou Gehrig's disease and other degenerative disorders.

Structure-based drug design, in which the physical structure of a targeted protein is used to help identify compounds that will interact with it, has already been used to generate therapeutic agents for a number of infectious and metabolic diseases. 

A new projection estimates that by the middle of this century there could be an average 56 percent drop in the amount of water stored in peak snowpack in the McKenzie River watershed of the Oregon Cascade Range -   if there is a 3.6 degree Fahrenheit temperature increase.

Similar impacts may be found on low-elevation maritime snow packs around the world.

40 years ago, a technique now used for detecting tiny quantities of molecules, in situations from crime scene forensic analysis, to drug detection, to establishing the origins of works of art, was discovered.

But despite there being a dozen CSI shows that use this on American television, you probably never heard of it. 

In the early 1970s, researchers discovered that by roughening the metal surface upon which the molecules they were examining had been placed, they could increase the signal by which they could detect these molecules - by a million times. It became arguably the most sensitive method of analysis on surfaces that anyone has ever come up with.

Natural killer cells (NK cells) are part of our innate immune system. As they first line of defense, researchers agree that the body needs as many active NK cells as possible.

But, as is often the case, there can be too much of a good thing and researchers at the Helmholtz Centre for Infection Research (HZI) have shown how.