What's one of your worst memories? How did it make you feel? According to psychologists, remembering the emotions felt during a negative personal experience, such as how sad you were or how embarrassed you felt, can lead to emotional distress, especially when you can't stop thinking about it.

When these negative memories creep up, thinking about the context of the memories, rather than how you felt, is a relatively easy and effective way to alleviate the negative effects of these memories, a new study suggests.

Durham, NC — Ancient DNA adds a twist to the story of how barnyard chickens came to be, finds a study to be published April 21 in the journal Proceedings of the National Academy of Sciences.

Analyzing DNA from the bones of chickens that lived 200-2300 years ago in Europe, researchers report that just a few hundred years ago domestic chickens may have looked far different from the chickens we know today.

The results suggest that some of the traits we associate with modern domestic chickens -- such as their yellowish skin -- only became widespread in the last 500 years, much more recently than previously thought.

"It's a blink of an eye from an evolutionary perspective," said co-author Greger Larson at Durham University in the United Kingdom.

Durham, NC — Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first
warm spell or rainy day would risk disaster. More than just an insurance policy against late frosts or unexpected dry spells, it turns out that seed dormancy has long-term advantages too: Plants whose seeds put off sprouting until conditions are more certain give rise to more species, finds in a team of researchers working at the National Evolutionary Synthesis Center in North Carolina.

Parts of the landscape underlying the massive Greenland ice sheet may have been undisturbed for almost 3 million years, since the island became completely ice-covered, say researchers who based their discovery on an analysis of the chemical composition of silts recovered from the bottom of an ice core more than 3,000 meters long. 

The find suggests "pre-glacial landscapes can remain preserved for long periods under continental ice sheets." 

In the time since the ice sheet formed "the soil has been preserved and only slowly eroded, implying that an ancient landscape underlies 3,000 meters of ice at Summit, Greenland," they conclude.

Most academics don't like competition but in the field of artificial intelligence, everyone wants to square off against the best in their discipline.

In June, the International Planning Competition held every two years will take place in  New Hampshire. It  is divided into four categories, the most significant of which is considered the “deterministic track”. This is for programs designed to eliminate any element of chance from automated planning in a wide range of fields, such as logistics, robot manipulation, satellite movement and transport. 

Mercury levels in excess of U.S. Environmental Protection Agency health thresholds for potential impacts to fish, birds, and humans have been detected in fish in some of the most remote national park lakes and streams in the western United States and Alaska.

 Mercury is harmful to human and wildlife health. It arises from natural sources, such as volcanic eruptions, and from human sources such as burning fossil fuels in power plants. Mercury is distributed at local or regional scales as a result of current and historic mining activities. Human activities have increased levels of atmospheric mercury at least three fold during the past 150 years.