Science & TechnologyS


Info

Sleep deprivation is a global epidemic, says international sleep study

Brett Smith
RedOrbit
Wed, 04 Sep 2013 00:18 UTC
Sleep Deprivation
© Twin Design / Shutterstock
A new international poll from the National Sleep Foundation (NSF) found stark differences in sleeping habits among residents of the United States, Canada, Mexico, the United Kingdom, Germany and Japan for people between the ages of 25 and 55 years old.

While the Americans and Japanese in the study reported having the least amount of sleep during the week on average, Canadians and Mexicans reported the most, at just over seven hours per weeknight.

"As the first international public opinion poll on sleep, the National Sleep Foundation 2013 Bedroom Poll makes an important contribution to the field," said Namni Goel, an associate professor of psychology at the University of Pennsylvania and a member of the NSF 2013 International Bedroom Poll expert panel.

"Although we know that everyone sleeps, the rather remarkable cultural differences within this universal experience have not been adequately explored. It is NSF's hope that this initial poll will inspire more research on this critical yet understudied topic."

The survey suggested that most people around the world - from the western Pacific to North America to Europe - are not getting enough sleep. Less than one-half of people in Mexico, the United States, Canada, the United Kingdom and Germany report getting a good night's sleep every night or almost every night on weeknights. Just over half of Japanese participants, 54 percent, said they consistently get a good night's sleep.
Read More...
Robot

Remote controlled canines, a dog handler's best friend

Lee Rannals
RedOrbit
Tue, 03 Sep 2013 18:12 UTC
Remote Controlled Dogs
© Thinkstock
Canines are already powerful weapons against drug smugglers and natural disasters, but man's best friend is about to get a little more help. Scientists writing in the International Journal of Modeling, Identification and Control say they have created a way for humans to control a dog using a remote control.

The team created a device equipped with a microprocessor, wireless radio, GPS receiver, and an 'attitude and heading reference system.' This system helps to provide autonomous guidance for a canine using the embedded command module, which utilizes vibration and tones to help guide the canine in the direction it needs to go.

Researchers said that preliminary tests in both structured and non-structured environments show obedience accuracy of up to almost 98 percent. They envision this device being particularly useful in search and rescue situations where dogs are able to go into areas that are too narrow or dangerous for humans.

"The ability to autonomously control a canine has far reaching [implications]," the team wrote in the journal.
Read More...
Info

Hormone therapy may pose higher cancer risk in some women

Bahar Gholipour
LiveScience
Tue, 03 Sep 2013 15:01 UTC
HRT
© Dreamstime
Taking hormones to treat the symptoms of menopause is thought to increase women's risk of breast cancer, but this risk doesn't rise equally in all women, a new study finds.

The increase in risk varies depending on a woman's race, body mass index (BMI) and breast density, and some women may benefit from hormone therapy while facing little increase in cancer risk, the study found.

The researchers looked at nearly 1.65 million postmenopausal women ages 45 and older, and found that leaner women, as well as women with denser breasts, were more likely to see the detrimental effects of hormone replacement therapy (HRT) on their breast-cancer risk.

Among underweight and normal-weight women (defined as having a BMI lower than 25) in the study, those who used HRT had a 35 percent increased risk of breast cancer compared with those who did not use HRT. For obese women (those with a BMI of 30 or higher), the risk of breast cancer did not appear to be affected by hormone use.

Among women with extremely dense breasts, those who took HRT had a 40 percent increased risk of breast cancer compared with those who didn't take hormones, according to the study. High breast density means the breast is made up of more connective tissue, relative to the amount of fat tissue.
Read More...
Info

New fungus species found killing salamanders

Susan Milius
ScienceNews
Tue, 03 Sep 2013 15:43 UTC
Salamander
© Frank Pasmans One of Europe's fire salamander species, Salamandra salamandra (shown), is under attack from a newly discovered fungus.
The rogue chytrid fungus that has devastated more than 200 kinds of amphibians worldwide has an accomplice: a second species that researchers have discovered attacking fire salamanders.

Populations of frogs, salamanders and their relatives have been dwindling worldwide, and in 1999 scientists identified a surprising contributing factor - the fungus now nicknamed Bd. This Batrachochytrium dendrobatidis was the first member of the phylum of fungi called chytrids found to attack, and often kill, vertebrates. Now genetic tests have identified a second vertebrate-killing chytrid, the newly named Batrachochytrium salamandrivorans.

Researchers found the new fungus when volunteers reported a population crash in a yellow-and-black fire salamander, Salamandra salamandra, in the Netherlands. Numbers of salamanders fell to 4 percent of previous population levels in just three years. But genetic tests failed to find Bd, leading An Martel of Ghent University's veterinary center in Merelbeke, Belgium and her colleagues to realize that they had found another chytrid.

Lab tests showed that fungus spores from a sick salamander caused the disease in another one, Martel and her colleagues report September 2 in Proceedings of the National Academy of Sciences.

"It looks very cruel," Martel says. Within days of infection, the fungus eats away the skin of a salamander until scientists need a microscope to see skin remnants. Martel can treat animals in captivity but what to do in the wild remains a puzzle. "You cannot treat an environment with an antifungal," she says.
Read More...
Info

Researchers look to quantify viral diversity of mammals

Brett Smith
RedOrbit
Tue, 03 Sep 2013 15:39 UTC
Bats
© Thinkstock
In late 2002, the SARS epidemic ripped through Southeast Asia and rattled worldwide confidence in medical technology's capacity to prevent pandemics like those that have plagued human populations throughout history.

It was later discovered that the novel virus had spread to humans from mammals in Southeast Asia. By 2003, scientists had isolated the SARS virus from meat samples taken from a local market in Guangdong, China.

A new study published in the journal mBio attempts to get out in front of the next pandemic by estimating the total number of unknown diseases that could be found in mammals and the costs associated with identifying those viruses. Based on the work of a large international team, the report stated that there are at least 320,000 viruses in mammals awaiting discovery and collecting evidence of these viruses would cost approximately $6.3 billion.

"Historically, our whole approach to discovery has been altogether too random," said lead author Simon Anthony, a scientist at the Center for Infection and Immunity (CII) at Columbia University. "What we currently know about viruses is very much biased towards those that have already spilled over into humans or animals and emerged as diseases. But the pool of all viruses in wildlife, including many potential threats to humans, is actually much deeper."

"A more systematic, multidisciplinary, and One Health framework is needed if we are to understand what drives and controls viral diversity and following that, what causes viruses to emerge as disease-causing pathogens," he added.
Read More...
Info

Meteorite crater in Brazil reveals biggest extinction in Earth history


Culturekiosque
Tue, 03 Sep 2013 15:15 UTC
Perth, Australia - It's well known that the dinosaurs were wiped out 66 million years ago when a meteor hit what is now southern Mexico but evidence is accumulating that the biggest extinction of all, 252.3m years ago, at the end of the Permian period, was also triggered by an impact that changed the climate.

While the idea that an impact caused the Permian extinction has been around for a while, what's been missing is a suitable crater to confirm it. Associate Professor Eric Tohver of the University of Western Australia's School of Earth and Environment believes he has found the impact crater which reveals though the trigger was the same, the details are significantly different.

Last year Dr Tohver redated an impact structure that straddles the border of the states of Mato Grosso and Goiás in Brazil, called the Araguainha crater, to 254.7m years, with a margin of error of plus or minus 2.5m years. Previous estimates had suggested Araguainha was 10m years younger, but Dr Tohver has put it within geological distance of the extinction date.

The Chicxulub crater in Mexico, is 180km in diameter while the Araguainha is 40 kilometres across and was thought to be too small to have caused the chain reaction which brought about such mass extinction.
Read More...
Frog

Tiny Gardiner's frog listens with its mouth

Victoria Gill
BBC
Tue, 03 Sep 2013 14:15 UTC
Gardiner's frog
© UnknownThe Gardiner's frog is one of the world's smallest
Scientists have discovered how one of the world's smallest frogs is able to hear with its mouth.

The tiny, earless Gardiner's frog was assumed to be deaf.

But this study published in the Proceedings of the National Academy of Sciences revealed that it uses its mouth cavity to convey sound signals to its brain.

The discovery solves the mystery of why the earless frog produces loud, high-pitched squeaks.

The diminutive frogs, which live in the forests of the Seychelles, have no middle ear region at all, meaning they have no resonating eardrum.

Researchers had therefore assumed that the animals had no way to amplify and transmit sound waves from the environment into the inner ear and, via nerve cells, to the brain.

The Gardiner's frog is one of the world's smallest

But this research revealed that the species defied those assumptions.

The scientists made recordings of the frogs' calls and played them back to wild frogs in order to observe their behaviour.
Read More...
Question

Scientists baffled to discover that Venus' spin is slowing down

Tallbloke
Tallbloke's Talkshop
Mon, 02 Sep 2013 21:54 UTC
Venus
© Tallbloke's TalkshopPioneer photo of Venus in the UV.
More 'baffled scientists'. Good fun isn't it? From MNN:

Scientists mapping Venus's surface with the European Space Agency's Venus Express orbiter recently received a shock when features on the planet's surface appeared to have moved up to 12.4 miles from where they were expected to be, reports National Geographic.

The measurements, if correct, would seem to indicate that Venus' rotation has slowed by 6.5 minutes - a dramatic decrease on a planetary level - compared to when it was last measured just 16 years ago.

That last measurement was taken during NASA's Magellan mission in the 1990s, when a single rotation of Venus was calculated to take 243.015 Earth days. Magellan used the passing speed of surface features on the planet to make its calculation, and scientists have long held that measurement as the standard.

"When the two maps did not align, I first thought there was a mistake in my calculations, as Magellan measured the value [of Venus's spin] very accurately," said planetary scientist Nils Müller. "But we have checked every possible error we could think of."
Read More...
Fireball 5

Did ancient Earth-chilling meteor crash near Canada?

Becky Oskin
LiveScience
Mon, 02 Sep 2013 14:00 UTC
Impact Event
© Mukul SharmaThe high temperatures of the meteorite impact 12,900 years ago produced mm-sized spherules of melted glass with the mullite and corundum crystal structure shown here.
A meteor or comet impact near Quebec heaved a rain of hot melted rock along North America's Atlantic Coast about 12,900 years ago, a new study claims.

Scientists have traced the geochemical signature of the BB-sized spherules that rained down back to their source, the 1.5-billion-year-old Quebecia terrane in northeastern Canada near the Gulf of Saint Lawrence.

At the time of the impact, the region was covered by a continental ice sheet, like Antarctica and Greenland are today.

"We have provided evidence for an impact on top of the ice sheet," said study co-author Mukul Sharma, a geochemist at Dartmouth College in Hanover, N.H. The results were published today (Sept. 2) in the journal Proceedings of the National Academy of Sciences.
Read More...
Magnify

Human origins: Are we primate-pig hybrids?

Eugene M. McCarthy
macroevolution.net
Sun, 25 Aug 2013 00:00 UTC
The Hybrid Hypothesis
A new theory of human origins

Image
© UnknownChimpanzee
This article is a little different from others on this site, because it's about the findings of my own research. I'm a geneticist whose work focuses on hybrids and, particularly, the role of hybridization in the evolutionary process. Here, I report certain facts, which seem to indicate that human origins can be traced to hybridization, specifically to hybridization involving the chimpanzee (but not the kind of hybridization you might suppose!). You can access detailed and documented discussions supporting this claim from links on this page. But I'll summarize the basic reasoning here, without a lot of citations and footnotes. (If you would like to read an even briefer summary, click here; read about some objections to the theory here; also, a recent news story)
Read More...