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. 

Many people know about ultrasound because of its popularity in prenatal imaging - grainy, grey outlines of babies made using reflected sound waves. A new 'acoustic diode' could dramatically improve future ultrasound images by changing the way those sound waves are transmitted.

A new paper in Cell Reports finds that it doesn't take a lot of genetic changes to spur the evolution of new species—even if the original populations are still in contact and exchanging genes.

Once evolutionary divergence happens, though, it evolves rapidly, ultimately leading to fully genetically isolated species.

To reveal genetic differences critical for speciation,the researchers analyzed the genomes of two closely related butterfly species, Heliconius cydno and H. pachinus, which only recently diverged. Occupying similar ecological habitats and able to interbreed, these butterfly species still undergo a small amount of genetic exchange.

A new paper says that people who are aware of their own thoughts and emotions - mindful  - show less neural response to positive feedback than their less mindful peers. 

That means they are typically less impulsive.

Trait mindfulness is characterized by an ability to recognize and accept one's thoughts and emotions without judgment. Mindful individuals are much better at letting their feelings and thoughts go rather than getting carried away.

The world's best supercomputers are staggeringly inefficient and energy-intensive machines and the human brain is staggering in its own right; putting a brain's information into CDs would require a skyscraper full of them and, unlike MP3s, there is no way to just create a compression algorithm.

The 86 billion neurons in our brains are connected by synapses that not only complete myriad logic circuits, they also they continuously adapt to stimuli, strengthening some connections while weakening others. We call that process learning and its rapid, highly efficient computational processes can't be matched.