Testing the saliva of healthy older people for the level of the stress hormone cortisol may help identify individuals who should be screened for problems with thinking skills, according to a study published in Neurology. The study found that people with higher levels of cortisol in the evening were more likely to have a smaller total brain volume and to perform worse on tests of thinking and memory skills.

Could the sperm harpoon the egg to facilitate fertilization? That's the intriguing possibility raised by the University of Virginia School of Medicine's discovery that a protein within the head of the sperm forms spiky filaments, suggesting that these tiny filaments may lash together the sperm and its target.

The finding, 14 years in the making, has earned the cover of the scientific journal Andrology. It represents a significant step forward in the fine dissection of the protein architecture of the sperm's acrosomal matrix, an organelle in the sperm head, and suggests a new hypothesis concerning what happens during fertilization.

By: Michael Greshko, Inside Science – Some filmmakers really know how to get into their audience’s heads, new research suggests.

Last month, a team led by Matt Bezdek, a cognitive psychologist at the Georgia Institute of Technology in Atlanta, found that suspenseful movies -- including several by director Alfred Hitchcock -- actively limit the brain’s awareness of the visual periphery. The findings provide greater insight into how movies let us temporarily escape the real world.

A new device transforms paralysis victims’ breath into words.

Billed as a tool to help bring back the art of conversation for sufferers of severe paralysis and loss of speech, the prototype analyses changes in breathing patterns and converts ‘breath signals’ into words using pattern recognition software and an analogue-to-digital converter. A speech synthesizer then reads the words aloud.

The Augmentative and Alternate Communication (AAC) device is designed for patients with complete or partial loss of voluntary muscle control who don’t have the ability to make purposeful movements such as sniffing or blinking – gestures which previous AAC devices have come to rely upon.

Before gluten sensitivity was a running joke in popular culture, medical marijuana held the preeminent position as easy humor fodder. The reason was simple: It did nothing for glaucoma, beyond the placebo range, and though the vast majority of clinical pain patients were women, 75 percent of the "medical marijuana" cardholders were men.

There is a dark undercurrent to Indiana's school culture, according to a recent statement, and it's created a secret smuggling web where young children acquire and trade illegal items.

The good news: The illegal items aren't marijuana or heroin.

The strange news: It's salt.

Parents go to great lengths to ensure the health and well-being of their developing offspring. The favor, however, may not always be returned.

Dramatic research has shown that during pregnancy, cells of the fetus often migrate through the placenta, taking up residence in many areas of the mother's body, where their influence may benefit or undermine maternal health.

The presence of fetal cells in maternal tissue is known as fetal microchimerism. The term alludes to the chimeras of ancient Greek myth--composite creatures built from different animal parts, like the goat-lion-serpent depicted in an Etruscan bronze sculpture.

If you are a hunter and accidentally shoot an endangered eagle, you could go to jail and you will certainly have a criminal record. If you are a wind turbine company, you kill 100 eagles a year and pay a token fine.  An estimated 75 to 110 golden eagles die at a wind-power generation operation in Altamont, California each year. That is about one eagle for every 8 megawatts of energy produced yet no one is in Federal prison. 

We can be concerned about erosion due to man-made causes but it is nothing like what nature will randomly do in a single year, without ever once consulting Natural Resources Defense Council or other industry-funded groups.

The historic September 2013 storm that triggered widespread flooding across Colorado's Front Range eroded the equivalent of hundreds, or even as much as 1,000 years worth of accumulated sediment from the foothills west of Boulder, researchers at the University of Colorado Boulder have discovered. The findings in Geology suggest that erosion may not always be a slow and steady process, like due to housing or shifts in vegetation, but rather can occur in sudden, rapid bursts due to extreme weather events such as hundred- and thousand-year storms.

While past research on the question has found otherwise, a new study by Defense and Veterans Affairs researchers suggests that women in the military are at no greater risk than men for developing posttraumatic stress disorder, given similar experiences--including combat.

The study involved active-duty troops and veterans who are part of the Millennium Cohort Study. That effort has more than 200,000 participants in all and the new PTSD study included more than 2,300 pairs of men and women who were matched based on an array of variables--including combat exposure--and followed about seven years, on average.