Though marijuana use has gone up sharply since 2007, claims about its lack of harm compared to cigarettes or drugs are not based on evidence. Instead, studies have shown abnormalities in brain function and structure of long-term marijuana users and that chronic marijuana users have smaller brain volume in the orbitofrontal cortex (OFC), a part of the brain commonly associated with addiction, but also increased brain connectivity. 

But the effects of chronic marijuana use on the brain may depend on the age of first use and duration of use, according to researchers. 

The need for a moral higher power may have been as necessary for adapting to a dangerous world as physical adaptations, according to a new paper.

The authors suggest that societies with less access to food and water are more likely to believe in such deities. They believe there is a strong correlation between belief in high gods who enforce a moral code and other societal characteristics. Political complexity - namely a social hierarchy beyond the local community - and the practice of animal husbandry were both strongly associated with a belief in moralizing gods, though how raising livestock factored in is a mystery, since everyone did it.

Boston, MA - Among pregnant women infected with HIV, the use of antiretroviral (ARV) medications early in pregnancy to treat their HIV or to prevent mother-to-child transmission of HIV does not appear to increase the risk of birth defects in their infants, according to a new study led by Harvard School of Public Health (HSPH). It is one of the largest studies to date to look at the safety of ARV use during pregnancy.

While the study found that overall risk was low--in keeping with previous research that has found ARV use in pregnancy to be generally safe--the researchers did find that one ARV drug, atazanavir, was associated with increased risk of birth defects and they said it should be studied further.

The adult human body is made up of about 37 trillion cells. Microbes, mainly bacteria, outnumber body cells by 10 to 1. This huge community of microbes, called the microbiome, affects the health, development and evolution of all multicellular organisms, including humans, according to the latest craze in health supplement marketing and plenty of science papers latching onto the fad.

Symbiotic microbes can help prevent infection by disease-causing pathogens but sometimes the interaction goes the other way, with a pathogen or disease disrupting the normal community of symbiotic bacteria. In a new paper in the Proceedings of the National Academy of Sciences, a team of scientists from UC Santa Barbara say that a fungal pathogen of amphibians does just that.

The Inamori Foundation has awarded the 2014 Kyoto Prizes to biomedical engineer Dr. Robert Langer in medicine, theoretical physicist Professor Edward Witten in math, and Fukumi Shimura in the Arts. Each laureate received a diploma, a 20-karat gold Kyoto Prize medal and a cash gift of 50 million yen (approximately US $450,000) in recognition of lifelong contributions to society.  

The 1KITE project (1,000 Insect Transcriptome Evolution) seeks to understand the millions of living insect species that shape our terrestrial living space and both support and threaten our natural resources by analyzing more than 1,000 insect transcriptomes, a set of all RNA molecules.

Using a dataset consisting of 144 carefully chosen species, 1KITE scientists have just presented reliable estimates on the dates of origin and relationships of all major insect groups based on the enormous molecular dataset they collected. They show that insects originated at the same time as the earliest terrestrial plants about 480 million years ago.