Every organism needs nitrogen to survive and grow and many organisms do not have the ability to obtain nitrogen from molecular nitrogen (N2), the major component in the atmosphere because they lack the nitrogen fixation pathway and have to rely on supply of nitrogen that has been fixed by others.

The availability of fixed nitrogen, in the form of ammonium, nitrite and nitrate, consequently often limits primary production in the environment. That's one of the reasons why many fertilizers are rich in fixed nitrogen.

While politics is not yet post-racial - every criticism of the politics of a minority member of government is labeled racism - dating seems to be, according to UC San Diego sociologist Kevin Lewis after looking at patterns of 126,134 US users of the dating site OkCupid.com

A rudimentary form of life,
Haloferax volcanii, part of the family of single-celled organisms called archaea that until recently were thought to be a type of bacteria, is found in some of the harshest environments on earth. Now researchers have determined it is able to sidestep normal replication processes and reproduce by the back door.

A new computer model says it can predict, by census block group, where burglaries are likely to occur.

Using the model developed by a University of California Riverside sociologist Prof. Robert Nash Parker, the Indio police department in souther California has developed interventions to address the problem, and can better anticipate hot spots of criminal activity and deploy officers accordingly. They say they have had an 8 percent decline in thefts in the first nine months of 2013 - too small a variation to attribute to just the model but it certainly hasn't hurt.

Supercontinents have formed and broken apart throughout the geological history of Earth (see Rodinia) and about 300 million years ago, the Pangaea supercontinent was cobbled together.

While we generally attribute some instances of animal and plants existence in isolated areas to splitting continents, researchers in a new paper have instead linked Pangaea being formed to the largest mass extinction known, the Permian extinction, when up to 95% of species, 82% of genera and over 50% of families became extinct.

A research study headed by Victoria Leavitt, Ph.D. and James Sumowski, Ph.D., of Kessler Foundation, provides the first evidence for beneficial effects of aerobic exercise.

Hippocampal atrophy seen in MS is linked to the memory deficits that affect approximately 50% of individuals with MS. Despite the prevalence of this disabling symptom, there are no effective pharmacological or behavioral treatments.