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Arctic ice melt hastens arctic warming

MELBOURNE, May 4 (UPI) — An Australian study suggests melting sea ice as a major cause of arctic warming in the past two decades.


University of Melbourne researchers led by James Screen said the increased arctic warming was due to positive feedback between sea ice melting and atmospheric warming.

“The sea ice acts like a shiny lid on the Arctic Ocean,” Screen said. “When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it. What we found is this feedback system has warmed the atmosphere at a faster rate than it would otherwise.”

The scientists said their findings conflict with previous hypotheses that warmer air transported from lower latitudes toward the pole, or changes in cloud cover, are the primary causes of enhanced arctic warming.

The arctic region has experience the fastest warming of any area on Earth, partly caused by increasing human greenhouse gas emissions, Screen said. At the same time, the arctic ice has been declining dramatically.

Ian Simmonds, a professor at the university’s School of Earth Sciences and co-author of the research paper, says the findings are significant.

“It was previously thought that loss of sea ice could cause further warming,” Simmonds said. “Now we have confirmation this is already happening.”

The study appears in the journal Nature.

E-cigarettes helpful in quitting smoking

GENEVA, Switzerland, May 4 (UPI) — People who have used electronic cigarettes say they were a bit helpful to quit smoking, but the devices were described as unreliable, Swiss researchers say.

Study author Jean-Francois Etter of the University of Geneva in Switzerland says the study involved surveying 81 users and former users of e-cigarettes.

Ninety-five percent say the e-cigarettes were at least somewhat helpful to stop smoking.

However, some said they were concerned about potential toxicity and some described the devices as “poor quality,” “lack of reliability” and “frequent failures.”

“Although users’ comments were generally positive, many were concerned about safety and toxicity and questioned why no study has yet investigated these aspects,” Etter says in a statement.

“Several respondents were also concerned about the future legal status of e-cigarettes, and that they may possibly be banned. Very few studies have investigated these devices and research is now urgently required. There is an urgent need for research into the toxicity, efficacy and public health impact of e-cigarettes.”

The findings are published in the BMC Public Health.

Seascape strawberries: A good space berry?

WEST LAFAYETTE, Ind., May 4 (UPI) — Purdue University horticulturists say they’ve found a strawberry variety that might be a good candidate to feed astronauts on long space missions.

Professor Cary Mitchell and researcher Gioia Massa said astronauts might one day tend their own crops during long missions. The scientist tested several cultivars of strawberries and found one, called Seascape, that requires little maintenance and energy. They said Seascape strawberries are day-neutral, meaning they aren’t sensitive to the length of available daylight to flower. Seascape was tested with as much as 20 hours of daylight and as little as 10 hours and while there were fewer strawberries with less light, each berry was larger and the volume of the yields was statistically the same.

“I was astounded that even with a day-neutral cultivar we were able to get basically the same amount of fruit with half the light,” Mitchell said.

The researchers said Seascape is also a good candidate because the plans are relatively small, meeting NASA mass and volume restrictions. And since Seascape provides fewer, but larger, berries in a short period of time, there is less labor required of crew members who would have to pollinate and harvest the plants by hand.

“We’re trying to think of the whole system — growing food, preparing it and getting rid of the waste,” Massa said. “Strawberries are easy to prepare and there’s little waste.”

The study appears in the early online edition of the journal Advances in Space Research.

Brain stimulation may help depression

CHARLESTON, S.C., May 4 (UPI) — A U.S. study suggests repetitive transcranial magnetic stimulation therapy can produce significant antidepressant effects in some people.

The National Institutes of Health-funded researchers said they showed some depressed patients who don’t respond to or tolerate antidepressant medications might benefit from the non-invasive therapy.

The scientists, led by Dr. Mark George of the Medical University of South Carolina said the treatment is designed to activate underactive mood-regulating brain circuitry by targeting the top left front part of the brain with an electromagnetic coil that emits 3,000 pulses over a 37-minute session, researchers said. It can be safely administered in a doctor’s office with few side effects — unlike more invasive brain stimulation treatments, such as electroconvulsive therapy.

The treatment accounted for remissions in 14 percent of antidepressant-resistant patients actively treated, with few side effects. That compared to about 5 percent for a simulated treatment, the scientists said.

“This study should help settle the debate about whether rTMS works for depression,” said George. “We can now follow up clues suggesting ways to improve its effectiveness, and hopefully further develop a potential new class of stimulation treatments for other brain disorders.”

The study that included Harold Sackeim of Columbia University and Drs. David Avery of the University of Washington, Sarah Lisanby of Columbia University and William McDonald of Emory University appears in the journal Archives of General Psychiatry.

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Categorized | Other, Smoking
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