Entries in Nature (4)


Staying Safe During Adventures with Nature

Hemera Technologies/Thinkstock(WASHINGTON) -- As family and friends await the discovery of three hikers who were swept over a 317-foot waterfall in Yosemite National Park Tuesday, the three friends' presumed deaths are a reminder that when visiting parks and other nature sites, safety is key.

"Read any safety bulletin you see," said Jeffrey Olson, spokesman for the National Park Service, which oversees Yosemite. "When we put up railings at edges of places where it's obviously a long way down...we put those railings up for a reason. We want you to return again."

On Tuesday, Hormiz David, 22, of Modesto, Calif.; Ninos Yacoub, 27, of Turlock, Calif.; and Ramina Badal, 21, of Manteca, Calif., were on a church group outing at Yosemite when they climbed over a metal barricade on the Mist Trail.

"They went over the barricade and were playing in and around the water," Scott Gediman, a spokesman for Yosemite, told KFSN-TV.

Gediman said there was a sign saying "Danger" with a stick-figure person in midair.

"Apparently, they were taking photos, playing in the water," Gediman said. "One of the males lost his footing, started to slide down, the second male tried to rescue him and also lost his footing. Then the third person, the female, did. Unfortunately, it was a chain reaction of events."

They were swept over the Vernal Fall and into the Merced River.

The presumed deaths of the three hikers Tuesday bring the number of Yosemite's water-related deaths to six. Olsen said the National Park Service urges visitors to observe the signs, online tips and brochures.

"For safety, the things you do at home, at school, at work, those things you do to keep yourself safe -- don't leave those things home when you go on vacation," Olson said. "Many people say safety involves a large dose of common sense. There is plenty of adventure in national parks by staying on the safe side of a handrail."

Staying Safe With Nature

Before you head out into the wilderness, the National Park Service offered these safety tips:

-- Wear sturdy shoes and a hat.

-- Carry water and a flashlight.

-- Remember the sun and heat and poisonous snakes and plants.

-- Know your rock climbing and hiking limitations.

-- Leave an itinerary with family and friends and stick to it.

Copyright 2011 ABC News Radio


Researchers Discover Biological Pathway Linked to PTSD

Photo Courtesy - ABC News(ATLANTA) -- Although most people exposed to the horrors of war, trauma or abuse recover emotionally, up to 20 percent develop post-traumatic stress disorder -- a debilitating psychiatric disorder marked by flashbacks and nightmares.

The biological basis for PTSD remains unclear. But a new study offers clues about why some people rebound from horrific events while others relive them, and may lead to predictive tests and even treatments.

To tease out factors that contribute to PTSD risk and resilience, researchers led by Dr. Kerry Ressler, associate professor at Emory University in Atlanta, studied a group of 64 highly traumatized civilians (not veterans) treated at Atlanta's Grady Memorial Hospital, some of whom developed PTSD.

"In a lot of very impoverished, high-violence neighborhoods, we see high rates of trauma, and rates of PTSD can be as high as in veterans," Ressler said.

Based on previous evidence that the hormone-like molecule known as PACAP was important in the brain's response to stress, the researchers measured PACAP levels in the blood of their subjects. To their surprise, PACAP levels were higher in people with PTSD, and correlated with the severity of symptoms. But the boost was only significant in women.

"When we started we didn't have any expectation that there was going to have a gender specificity to it," Kessler said. "We were just looking and found a smaller effect, and then we split it by gender and found that the whole effect was in females."

The team repeated the experiment in a group of 74 traumatized women. Again, PACAP levels correlated with PTSD symptoms -- especially those considered essential for a diagnosis of PTSD: intrusive flashbacks, avoidance of trauma reminders and increased startle response.

"These data may begin to explain sex-specific differences in PTSD diagnosis, symptoms and fear physiology," Ressler and his colleagues wrote in their report, published Wednesday in Nature.

Women are known to have a higher risk of a range of anxiety disorders. But the finding of elevated PACAP in women with PTSD did more than offer a biological explanation for the gender difference; it pointed to a novel biological pathway underlying the brain's response to fear.

Copyright 2011 ABC News Radio


Aging Can Be Reversed in Mice, But What About Us?

Photo Courtesy - Getty Images(BOSTON) -- Scientists have found that by tweaking the genes of mice, they are able to slow, or even reverse the process of aging. With just a few changes, the animals were able to regenerate brain cells, and their fertility was able to be restored. Alternatively, mice aged prematurely when those changes were made in reverse order.

A report, published in the weekly online science journal Nature, shows that scientists hope similar results may be possible for humans down the road. The scientists who published the report, working out of the Dana Farber Cancer Center in Boston, worked with the chromosomes that are found inside the nuclei of all cells. By transforming the protective part of the chromosome, which guards the cell from diminishing, scientists could either accelerate, or reverse the aging process.

Some scientists say the study can be beneficial if the process eventually leads to cures for things like heart disease and diabetes, which become more debilitating with age.

So far the study has been restricted to mice.

Copyright 2011 ABC News Radio


Genetic Mutation May Lead to Violent and Reckless Behavior

Photo Courtesy - Getty Images(NEW YORK) -- In a discovery that could help scientists further understand impulsivity in humans, researchers have announced they found a genetic variant that may contribute to spontaneous violent behavior.

In a new study released in the journal Nature, a multinational research team examined the genes of 96 violent criminal offenders in Finland with behavioral disorders and compared it with DNA from a control group of 96 people in the country who had no such psychiatric diagnoses.

Scientists found that the criminal offenders were three times more likely to have a genetic mutation, known as the HTR2B Q20* mutation, than the control group.

The offenders had been diagnosed with antisocial personality disorder, borderline personality disorder or intermittent explosive disorder -- all conditions with symptoms of impulsive aggression.

The mutation was found to affect the brain's levels of serotonin, a neurotransmitter that affects mood, appetite, sleep and impulsive behavior.

"Impulsivity is a normal dimension of behavior, but it also plays a role in many psychiatric disorders, including alcoholism and suicidalism," said Dr. David Goldman, chief of the Laboratory of Neurogenetics at the National Institute on Alcohol Abuse and Alcoholism, in Bethesda, Md., and senior author of the study. "These disorders are often difficult to disentangle at the causal level, but by studying traits, we can find genes that contribute to important aspects of them."

Researchers specifically conducted the study in Finland because of its unique population and medical genetics. Goldman said modern Finns descend from a relatively small number of original settlers, which increased the chance of finding specific genes that influence impulsive behavior.

"Finns have the same degree of genetic diversity as people from other cultures, but their genetic disease diversity is reduced," said Goldman. "Genetic heterogeneity tends to be reduced in Finland because of its unique population, which was founded by two major waves of migration." 

Copyright 2010 ABC News Radio

ABC News Radio