A new study correlates Finland's national tobacco policies - less smoking, more snus, for those addicted to nicotine - seem to be radically reducing the incidence of subarachnoid hemorrhage, the most fatal form of stroke.

Previously it was thought that in Finland approximately a thousand people suffer subarachnoid hemorrhage (SAH) every year - most of them adults of working age. Up to half of those afflicted die within a year. Subarachnoid hemorrhage is typically caused by a ruptured cerebral aneurysm, which leads to a sudden increase in the intracranial pressure. Smoking is a key risk factor for SAH and lots of other diseases, whereas nicotine, the addictive component, is not. 

Atmospheric scientists overwhelmingly deny the existence of a secret, elite-driven plot to release harmful chemicals into the air from high-flying aircraft, according to the first peer-reviewed journal paper to address the "chemtrails" conspiracy theory.

Researchers from the University of California, Irvine, the Carnegie Institution for Science and the nonprofit Near Zero organization asked 77 atmospheric chemists and geochemists if they had come across evidence of such a large-scale spraying program, and 76 responded that they had not. The survey results were published Wednesday in Environmental Research Letters.

Plant scientists at the University of Cambridge have found that the cucumber mosaic virus (CMV) alters gene expression in the tomato plants it infects, causing changes to air-borne chemicals - the scent - emitted by the plants. Bees can smell these subtle changes, and glasshouse experiments have shown that bumblebees prefer infected plants over healthy ones.

Scientists say that by indirectly manipulating bee behaviour to improve pollination of infected plants by changing their scent, the virus is effectively paying its host back. This may also benefit the virus: helping to spread the pollen of plants susceptible to infection and, in doing so, inhibiting the chance of virus-resistant plant strains emerging.

Researchers at Technical University of Munich discovered that our brain actively takes sugar from the blood. Prior to this, researchers around the world had assumed that this was a purely passive process. An international team led by diabetes expert Matthias Tschöp reported in the journal 'Cell' that transportation of sugar into the brain is regulated by so-called glia cells that react to hormones such as insulin or leptin; previously it was thought that this was only possible for neurons.

You shouldn't believe everything you read. The CDC insists salt is a problem, and the FDA asked for voluntary warning labels after the sue-and-settle lawyer group Center for Science in the Public Interest kept harassing them. Yet the evidence shows salt in a normal diet is no problem. And no quote on Facebook that has a picture of Einstein included is any more accurate. The US government promotes a prediabetes designation that has the rest of the world scratching their heads.

Even textbooks are often wrong. That is the problem with voting on science. 

Being hospitalized with infection was associated with an increased risk of suicide death and the highest risk of suicide was among those individuals with hepatitis and HIV or AIDS, according to a study published online by JAMA Psychiatry.

While psychological predictors of suicide have been studied extensively, less attention has been paid to the effect of biological factors, such as infection.

Helene Lund-Sørensen, B.M., of Copenhagen University Hospital, Denmark, and coauthors used Danish nationwide registers to investigate associations between infectious diseases and the risk of death by suicide.