Two Greenland Glaciers Lose Enough Ice to Fill Lake Erie

ScienceDaily — A new study aimed at refining the way scientists measure ice loss in Greenland is providing a "high-definition picture" of climate-caused changes on the island.

And the picture isn't pretty.

In the last decade, two of the largest three glaciers draining that frozen landscape have lost enough ice that, if melted, could have filled Lake Erie.

The three glaciers -- Helheim, Kangerdlugssuaq and Jakobshavn Isbrae -- are responsible for as much as one-fifth of the ice flowing out from Greenland into the ocean.

"Jakobshavn alone drains somewhere between 15 and 20 percent of all the ice flowing outward from inland to the sea," explained Ian Howat, an assistant professor of earth sciences at Ohio State University. His study appears in the current issue of the journal Geophysical Research Letters.

As the second largest holder of ice on the planet, and the site of hundreds of glaciers, Greenland is a natural laboratory for studying how climate change has affected these ice fields.

Researchers focus on the "mass balance" of glaciers, the rate of new ice being formed as snow falls versus the flow of ice out into the sea.

The new study suggests that, in the last decade, Jakobshavn Isbrae has lost enough ice to equal 11 years' worth of normal snow accumulation, approximately 300 gigatons (300 billion tons) of ice.

"Kangerdlugssuaq would have to stop flowing and accumulate snowfall for seven years to regain the ice it has lost," said Howat, also a member of the Byrd Polar Research Center at Ohio State.

Surprisingly, the researchers found that the third glacier, Helheim, had actually gained a small amount of mass over the same period. It gained approximately one-fifteenth of what Jakobshavn had lost, Howat said.

The real value of the research, however, is the confirmation that the new techniques Howat and his colleagues developed will provide scientists a more accurate idea of exactly how much ice is being lost.

"These glaciers change pretty quickly. They speed up and then slow down. There's a pulsing in the flow of ice," Howat said. "There's variability, a seasonal cycle and lots of different changes in the rate that ice is flowing through these glaciers."

Past estimates, he said, have been merely snapshots of what was going on at these glaciers in terms of mass loss. "We really need to sample them very frequently or else we won't really know how much change has occurred.

"This new research pumps up the resolution and gives us a kind of high-definition picture of ice loss," he said.

To get this longer-timeframe image, Howat and colleagues drew on data sets provided by at least seven orbiting satellites and airplanes, as well as other sources.

"To get a good picture of what's going on, we need different tools and each one of these satellites plays an important role and adds more information," Howat said.

The next step is to look at the next-largest glaciers in Greenland and work their way down through smaller and smaller ice flows.

"Currently, the missing piece is ice thickness data for all of the glaciers, but a NASA aircraft is up there getting it. When that's available, we'll be able to apply this technique to the entire Greenland ice sheet and get a monthly total mass balance for the last 10 years or so," he said.

Along with Howat, Yushin Ahn, a postdoctoral fellow at Ohio State's Byrd Polar Research Center; Ian Jouglin of the University of Washington; Michael van den Broeke and Jan Lenaerts, both of Utrecht University in the Netherlands, worked on the project.

The work is supported in part by the National Aeronautics and Space Administration and by the Climate, Water and Carbon Program at Ohio State.

Source: Sciencedaily.com

Wildlife in Trouble from Oil Palm Plantations, Researchers Say

ScienceDaily — Forest fragmentation driven by demand for palm oil is having a catastrophic effect on multiple levels of biodiversity, scientists from Queen Mary, University of London have discovered.

The researchers are worried that unless steps are taken to safeguard and manage the remaining forest, then certain species will struggle to survive.

The study, which focused on bats as an indicator of environmental change, was published in the journal Ecology Letters.

The team conducted bat surveys in pristine forest and also in forest patches of varying size in central Peninsular Malaysia. They recorded the numbers of different species present and also assessed the level of genetic diversity within populations of some species.

Lead author Matthew Struebig, jointly based at Queen Mary University of London and the University of Kent, said: "We found that smaller forest areas support fewer species, and that those species that remain face an eventual decline, potentially leading to local extinction in the long-term."

When the team compared the number of species present to genetic diversity within populations they found that fragmentation appeared to have an even greater impact on genetic loss, which might also be important for long-term population viability.

"We found that in order to retain the numbers of bat species seen in pristine forest, forest patches had to be larger than 650 hectares, however to retain comparable levels of genetic diversity, areas needed to be greater than 10,000 hectares," he said.

Co-author Stephen Rossiter, also at Queen Mary, emphasised that the findings could have important implications for forest management in the face of the ever-growing demand for oil palm plantations.

He said: "We found that while more species existed in larger forest patches, even small fragments contributed to overall diversity. Therefore, conservation managers should aim to protect existing small fragments, while seeking to join up small forest areas to maximise diversity."

Source: Sciencedaily.com

Octopuses Make Some Pretty Good Moves

ScienceDaily — In case you thought that octopuses were smart only in guessing the outcome of soccer matches (remember the late Paul the octopus in Germany who picked all the right winners in last year's world cup matches in Johannesburg?), scientists at the Hebrew University of Jerusalem have now shown that not only are they smart, they can make some pretty good moves as well.

Octopuses are among the most developed invertebrates. They have large brains and are fast learners. With eight arms and no rigid skeleton, they perform many tasks like crawling, swimming, mating and hunting. And unlike most animals such as humans -- who are restricted in their movements by a rigid skeleton which helps in determining the position of their limbs -- octopuses have limitless flexibility.

But because they have no such rigid structure, it was believed that the octopuses have only limited control over their eight flexible limbs. However, the Hebrew University researchers have shown otherwise. They developed a three-choice, transparent, plexiglass maze that required the octopus to use a single arm and direct it to a visually marked compartment outside of its tank of water that contained a food reward.

The octopuses in the experiment learned to insert a single arm through a central tube, out of the water, and into the correct marked goal compartment to retrieve the food reward. This success was dependent on visual information, which the octopuses were able to translate into a series of coordinated movements made by a single arm and retrieve the food. They were also able to repeat this process.

The completion of this task shows for the first time that an octopus can direct a single arm in a complex movement to a target location. Motor control issues, such as this, are the basis of an ongoing European Union research project aimed at building a "robot octopus." To understand how the octopus controls its movements, and to what extent it controls them, is therefore an important base for the design of the control architecture of a robot devoid of a rigid skeleton.

The research was reported on in a recent edition of Current Biology, and was authored by Tamar Gutnick, Prof. Binyamin Hochner and Dr. Michael Kuba of the Interdisciplinary Center for Neural Computation at the Alexander Silberman Institute of Life Sciences at the Hebrew University, and Dr. Ruth A. Byrne of the Medical University of Vienna, Austria.

Source: Sciencedaily.com

Archaeologists Uncover Oldest Mine in the Americas

ScienceDaily (May 19, 2011) — Archaeologists have discovered a 12,000-year-old iron oxide mine in Chile that marks the oldest evidence of organized mining ever found in the Americas, according to a report in the June issue of Current Anthropology.

A team of researchers led by Diego Salazar of the Universidad de Chile found the 40-meter trench near the coastal town of Taltal in northern Chile. It was dug by the Huentelauquen people -- the first settlers in the region -- who used iron oxide as pigment for painted stone and bone instruments, and probably also for clothing and body paint, the researchers say.

The remarkable duration and extent of the operation illustrate the surprising cultural complexity of these ancient people. "It shows that [mining] was a labor-intensive activity demanding specific technical skills and some level of social cooperation transmitted through generations," Salazar and his team write.

An estimated 700 cubic meters and 2,000 tons of rock were extracted from the mine. Carbon dates for charcoal and shells found in the mine suggest it was used continuously from around 12,000 years ago to 10,500 years ago, and then used again around 4,300 years ago. The researchers also found more than 500 hammerstones dating back to the earliest use of the mine.

"The regular exploitation of [the site] for more than a millennium … indicates that knowledge about the location of the mine, the properties of its iron oxides, and the techniques required to exploit and process these minerals were transmitted over generations within the Huentelauquen Cultural Complex, thereby consolidating the first mining tradition yet known in America," the researchers write. The find extends "by several millennia the mining sites yet recorded in the Americas."

Before this find, a North American copper mine dated to between 4,500 and 2,600 years ago was the oldest known in the Americas.

Source: Sciencedaily.com

Extremely Obese Children Have Higher Prevalence of Psoriasis, Higher Heart Disease Risk

ScienceDaily (May 18, 2011) — Children who are overweight or obese have a significantly higher prevalence of psoriasis, and teens with psoriasis, regardless of their body weight, have higher cholesterol levels, according to a Kaiser Permanente study published online in the Journal of Pediatrics. The study findings suggest that higher heart disease risk for patients with psoriasis starts in childhood in the form of higher cholesterol levels.

Psoriasis is a chronic inflammatory disease of the skin that often starts early in life and, according to the National Psoriasis Foundation, affects more than 7 million Americans.

"This study suggests a link between obesity and psoriasis in children," said study lead author Corinna Koebnick, PhD, a research scientist at the Kaiser Permanente Southern California's Department of Research & Evaluation in Pasadena, Calif. "But our study findings also suggest that the higher heart disease risk for patients with psoriasis starts in childhood in the form of higher cholesterol levels. We may need to monitor youth with psoriasis more closely for cardiovascular risk factors, especially if they are obese."

Researchers used electronic health records to study 710,949 racially and ethnically diverse children and found that obese children were almost 40 percent more likely to have psoriasis than normal weight children. Extremely obese children were almost 80 percent more likely to have psoriasis than normal weight children. Additionally, among youth with psoriasis, it was four times more likely that the psoriasis would be severe or more widespread in obese youth than what was seen in normal weight children. Additionally, teens with psoriasis had 4 to16 percent higher cholesterol levels and liver enzymes, regardless of their weight, than youth without this condition.

"Very little is known about psoriasis in children where the disease is mostly viewed and treated as a burdensome skin condition and less considered a metabolic disease," adds Dr. Koebnick.

"Psoriasis may also put children at risk for metabolic disease, as seen in adults, so studies such as these are extremely important in helping primary care providers learn the best way to care for these children," notes co-author Amy Porter, MD, Southern California Permanente Medical Group's regional physician lead for weight management, and pediatrician at Kaiser Permanente's Baldwin Park Medical Center.

Epidemiologic studies in adults have shown that patients with psoriasis are at a higher risk of developing metabolic conditions such as diabetes, hypertension, heart attack and stroke. In adults, obesity has also been linked to a higher risk of developing psoriasis, and obesity, like psoriasis, is also associated with an increased risk of cardiovascular disease, metabolic syndrome and diabetes.

"Both conditions are characterized by a chronic low-level inflammation," notes Dr. Koebnick. "Yet, we know little to nothing about the metabolic risk of psoriasis, especially when combined with obesity in children." Psoriasis in children may increase blood cholesterol levels, and this may additionally be triggered by the presence of obesity. While the present study has limitations due to its cross-sectional design where both body weight and information on psoriasis were assessed at the same time, future studies based on this cohort will address these issues.

"It has been well described that adults with psoriasis have increased cardiovascular risk factors, but we have now examined these issues in children. As we follow these patients over 30-40 years, we will be able to determine if these increased cardiovascular risk factors in turn increase the risk for major adverse cardiac events," said study senior author, Jashin J. Wu, M.D., director of clinical research and the associate residency program, and director for the department of dermatology at Kaiser Permanente Los Angeles Medical Center.

This study is part of the Kaiser Permanente Southern California Children's Health Study, Kaiser Permanente's ongoing work to identify and treat childhood obesity through research and community programs.

Other study authors included: Mary Helen Black, MS, PhD, Ning Smith, MS, and Steven J. Jacobsen, MD, PhD, from the Kaiser Permanente Department of Research & Evaluation in Pasadena, Calif.; Amy H. Porter, MD, from the Kaiser Permanente Baldwin Park Medical Center; and Jack K. Der-Sarkissian, MD, and Jashin J Wu, MD from the Kaiser Permanente Medical Center, Los Angeles.

Source: Sciencedaily.com