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WASHINGTON – Hibernating bears ordered their forcefulness demands on low, but unlike most another animals that verify daylong winter naps they don't apprehensiveness discover rattling much, researchers reportable Thursday.

Figuring discover how they revilement forcefulness ingest but ease ready their embody temperature relatively hearty could digit period hit essential implications for treating victims of hunch attack, stroke and another conditions, scientists hope.

The embody temperature of diminutive asleep mammals crapper drop to nearby freezing. But that is not the housing for the more human-sized black bears, according to the newborn investigate published in the book Science. The findings also were presented at the period meeting of the dweller Association for the Advancement of Science.

The study's grownup author, Brian M. Barnes of the Institute for Arctic Biology at the University of Alaska, noted that after hibernating, black bears don't undergo the expiration of pearl and hooligan mass that occurs in humans after a daylong period of inactivity.

He said that if scientists could meliorate see the mechanisms behindhand the lower metabolous demand, it strength be doable to amend newborn therapies and medicines for people.

While it would require a aggregation more research, scientists feature discernment how the impact of hibernation works strength aid in preventing osteoporosis and hooligan atrophy from disuse — mayhap allowing doctors digit period to place injured, unfit grouping in a identify of suspended or baritone aliveness until they are healed.

Barnes, Oivind Toien and colleagues unnatural fivesome black bears — three males and digit females — that Alaska wildlife officials had categorised as nuisances and distant from areas around people.

The bears were provided with wooden nest boxes fitted with cameras and good recorders as substantially as instruments to measure gas consumption. The bears each had implanted transmitters to measure their temperature, hunch evaluate and hooligan activity.

The scientists found that kinda than having their temperature drop to nearby freezing, the bears went through cycles of individual life when their temperature lapse to 86 degrees. Then they began symptom and the readings climbed backwards to about 97 degrees, nearly normal.

However, modify though they remained relatively warm, the bears' metastasis lapse to rattling baritone levels. Their gas ingest was baritone by 75 percent from season rates and their hunch evaluate lapse from 55 beatniks per minute to 14 beatniks per minute.

In another surprise, the researchers discovered that bears, like groggy grouping in the morning, are andante to better from hibernation. The researchers had expected to find the animals' metastasis backward to connatural levels correct away. But instead, the bears' metabolous rates did not return to their astir levels for digit to three full weeks.

Biologist Lynn Rogers of the North dweller Bear Center in Ely, Minn., said his studies hit shown that hibernation varies with how substantially fed bears are.

"Well-fed bears don't hit to drop their temperature as such ... The bears that are skinny hit to drop their temperatures to as baritone as 88, and become such more indolent in their dens."

If well-fed bears "are sleeping, I crapper usually hear their hunch rate; it echoes in the habitation on a stilly winter day. If the skinny ones are sleeping, it's hornlike to wake them up and you can't hear a hunch rate," he said in a ring interview.

Gerhard Heldmaier, a doc in birdlike physiology at Philipps University in Marburg, Germany, termed it surprising that, unlike diminutive mammals, the baritone metastasis is primarily answerable for hibernation in bears, with temperature playing only a secondary role.

Yet the study shows that modify without a major temperature drop, bears do in fact hibernate, said Heldmaier, who was not conception of the investigate team.

The investigate was based by the U.S. Army Medical Research and Materiel Command, National Science Foundation, National Institutes of Health, Stanford University, dweller Heart Association and the senator Program.

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Online: http://www.sciencemag.org

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