Woolly rhinos came down from the cold

Ice Age icons were pre-adapted to harsh climate, new fossils suggestWeb edition : Thursday, September 1st, 2011 COOL RHINOFossils of a new species of woolly rhino, shown here in an artist's reconstruction, have turned up in pre–Ice Age deposits high in the foothills of the Himalayas.Julie Naylor

A new trove of mammal fossils found high in the foothills of the Himalayas suggests that Tibet may have been a harsh, cold testing ground where woolly rhinos and other big mammals developed their cold-climate cool well before the Ice Age began.

Among the treasures from the Zanda Basin is the oldest fossil yet found of a woolly rhino, dating from about 3.7 million years ago, says vertebrate paleontologist Xiaoming Wang from the Natural History Museum of Los Angeles County. The complete skull and several neck vertebrae of the now extinct animal represent a new species, Coelodonta thibetana, Wang and his colleagues report in the Sept. 2 Science.

“It’s an important find,” says vertebrate paleontologist Donald R. Prothero of Occidental College in Los Angeles, who studies the evolution of mammals, including woolly rhinos. The paper is the first evidence for the idea that the lineage of the iconic Ice Age giant, and maybe other species, had already evolved cold-weather adaptations instead of developing them as the big chill set in 2.8 million years ago.

HIGH-ALTITUDE FINDSPaleontologists working in Tibet discovered the skull and lower jaw, shown here in a digital composite, of an ancient species of woolly rhino, Coelodonta thibetana.Image courtesy of Xiaoming Wang

When the Ice Age did come, descendants of the early Tibetan rhinos could have moved gradually off the plateau to lower altitudes throughout Eurasia. Wang and his colleagues note that fossil locations of three later woolly rhino species fit the pattern of a lineage that diversified down and out of the high plateau. “Tibet as a special environment probably is the cradle of some of the cold-adapted species of the Ice Age,” Wang concludes.

That’s a reasonable scenario, Prothero says. “I don’t think it’s been suggested before because there was no evidence for it.”

Wang and his colleagues found such evidence in the Zanda Basin, which sits 3,700 to 4,500 meters above sea level and is surrounded by even higher peaks. “It’s like working on top of Mount Whitney,” the highest peak in the contiguous United States, Wang says.

Toward the end of the field season in August 2007, Wang himself was exploring late in the afternoon a few miles from his colleagues when he stumbled onto a big piece of fossilized bone. Recognizing it as a vertebra, he swung his hammer at a promising spot — and uncovered a hint of what he calls the biggest discovery of his career. “Here is a tooth of a woolly rhino revealed by one single whack of my hammer,” he remembers.

Subtle characteristics identified the skull as a more ancestral species than later, Ice Age woolly rhinos. The Tibetan rhino already had such adaptations as a forward-leaning, flattened horn convenient for sweeping aside snow while foraging for food. The research team estimates the skull came from a mid-sized rhino about the size of today’s Indian and black rhinos. The fossils did not include hair, so paleontologists can only speculate about how woolly it might have been.

In addition to the newly named C. thibetana, the basin has also revealed other cold-adapted mammals whose descendants might have spread during the Ice Age, such as blue sheep and the Tibetan wild ass.

Some Ice Age mammals “probably came from high elevations and were pre-adapted to cold, but I wouldn’t want to say everything followed this pattern,” Prothero cautions. “In the real world nature is always more complex.”

Found in: Life

View the original article here

Fighting flames with greener materials

New flame retardants rely on alternating nanolayers of relatively nontoxic materialsWeb edition : Wednesday, August 31st, 2011 FOAMING BUBBLESAn electron micrograph shows cotton fabric coated with 20 paired layers of chemicals before (left column) and after (right column) burning. Bubbles in the lower right photo show the coating’s heat-triggered foaming.Y.-C. Li et al/Advanced Materials 2011/Wiley-VCH Verlag

Materials scientists in Texas have developed flexible coatings mere billionths of a meter thick that keep cotton clothing from going up in flames and plastic foam from melting. Unlike the widely used but potentially toxic flame retardants they've been designed to replace, these nano-coatings appear relatively safe, their designers say.

Yu-Chin Li and Jaime Grunlan of Texas A&M University in College Station described their team’s new technologies August 31 at the American Chemical Society national meeting in Denver.

Because fabric fibers are so thin, “being able to fire-retard them is a big deal,” observes chemist Charles Wilkie of Marquette University in Milwaukee, a fire-retardant specialist not involved with the new work. “So I’m encouraged. The new work is impressive.”

Grunlan’s team has been seeking safer alternatives to brominated fire retardants, some of which have been banned over concerns about their potential toxic effects. The researchers’ initial prototypes consisted of alternating layers of garden variety clay and a commercial polymer. But the polymer, a synthetic chemical, did not rely on renewable, green constituents. So the engineers swapped it out for an inexpensive waste material: chitosan, a natural compound extracted from shrimp and lobster shells.

Like the earlier clay-based recipes the group had worked with, the new formulation proved disappointing on cotton fabric, Grunlan says. But it was a game changer for plastic foam, such as the type used as cushioning in furniture. Untreated foam held over a propane torch flame for 10 seconds quickly ignited, melted and burned up. But after applying 10 dual layers of clay and chitosan to an identical piece of foam, the 10-second flame created a thin veneer of char but left the interior unscathed.

Still intent on finding fabric protectants, the team turned to materials that intumesce — undergo a foaming chemical reaction — at high temperatures. In the construction industry, millimeter-thick intumescent coatings on steel girders protect a skyscraper’s skeleton. Grunlan’s group scaled the technology down to nanometer-thick alternating layers of the compounds, polysodium phosphate and poly-allylamine. 

When cotton fabric treated with 10 alternating layers of each chemical was exposed to a flame for 10 seconds, the fabric charred but didn’t burn up, Grunlan says. The only sign of damage was localized, minor charring where the flame touched the fabric. Li, Grunlan and colleagues published details of these experiments online July 29 in Advanced Materials.

These data “sound really good,” Wilkie says — if the concern is preventing ignition of flammable materials. But in the real world, fires last considerably longer than 10 seconds, he points out, so these materials might retard burning or limit its spread, but wouldn’t withstand an inferno.

Vince Baranauskas of NanoSonic Inc. in Pembroke, Va., a firm that engineers materials including fire retardants, cautions that nano-layered flame retardants may not be feasible on a commercial scale. “Alternating dips would cost a great deal more than the fabric itself,” he says.

But Serge Bourbigot of the University of Lille in Villeneuve d'Ascq, France, remains optimistic. The new nanolayer fire retardants — with or without intumescence — are novel and show great potential, he says, even if they might need refinements before they are marketed.

Found in: Environment, Molecules and Technology

View the original article here

News in Brief: Body & Brain

One defense against diarrhea and early hints of diabetes in obese children in this week’s newsWeb edition : Wednesday, August 31st, 2011

Body’s diarrhea defense
The body has a biological mechanism tailor-made to fend off infections by Clostridium difficile, a bacterium responsible for many hospital-acquired diarrheal infections. Reporting online August 21 in Nature Medicine, researchers at Case Western Reserve University and colleagues from other institutions show that a compound called S-nitrosoglutathione can bind to toxins secreted by the microbe and neutralize them before they damage cells. Increased levels of S-nitrosoglutathione in the guts of mice protected them from C. difficile, the researchers report. —Nathan Seppa

Third graders en route to adult disease
Obese but apparently healthy children 7 to 9 years old were twice as likely to be insulin resistant (a hallmark of impending diabetes) as were normal weight children their age, a team of scientists from U.S. universities finds. The scientists compared a range of features characterizing the blood, vascular health and fat-processing in 123 children. A whole host of prediabetes and pre-heart disease changes were evident in the obese youngsters. These children also were beginning to store fat outside of normal sites, the researchers report online August 25 in Obesity. The results “highlight the importance of interventions to prevent and manage obesity” very early in life. —Janet Raloff

Found in: Body & Brain

View the original article here

Obesity can turn body fat toxic

A lucky few escape the link with disease-causing inflammation, two studies findWeb edition : Friday, September 2nd, 2011

Obesity can trigger inflammation in the fat cells found just below the skin, creating an environment that has been linked with the development of both diabetes and heart disease, two new studies indicate.

The findings suggest that people need to worry about all types of body fat, not just the deeply embedded fat that earlier work had focused on. But the new work also hints that some face a higher risk than others.

In the body, most fat clusters under the skin in what’s known as subcutaneous adipose tissue. Much of the rest, called visceral fat, accumulates within muscle and between organs deeper inside the body. For more than a decade, studies have shown that obesity triggers visceral fat to begin spewing hormonelike chemicals called cytokines. These proinflammatory chemicals have been linked with metabolic syndrome, a constellation of abnormalities that can include impaired insulin sensitivity (known as insulin resistance), fat buildup around the waist, high blood pressure and low concentrations of HDL, the good cholesterol.

“There’s been this sort of ill-proven idea that subcutaneous adipose tissue is not harmful and that visceral adipose tissue is the vicious demon that makes us sick,” says Gökhan S. Hotamisligil of the Harvard School of Public Health in Boston, who was not involved in the studies. The new data, he says, reinforce the fact that subcutaneous fat is far from benign.

In one study, Ishwarlal Jialal of the University of California, Davis Medical Center in Sacramento and his colleagues sampled blood and subcutaneous fat from 65 men and women. Most were clinically overweight or obese, and 39 had metabolic syndrome.

Subcutaneous fat from people with metabolic syndrome was rife with macrophages, a type of immune molecule that normally kills unwanted cells. But here, Jialal says, macrophages “appeared to be conspiring with fat cells to produce a host of proinflammatory cytokines,” whose levels correlated with an individual’s insulin resistance.

This proinflammatory environment was absent in people without metabolic syndrome — even among people who were very obese, the researchers report in the November Journal of Clinical Endocrinology & Metabolism, in an article posted online August 24. Although obesity predisposes people to develop metabolic syndrome, concludes Jialal, it takes more than excess fat to trigger it.

A related trial, published in the July 12 Journal of the American College of Cardiology, probed inflammation and metabolic impairments associated with subcutaneous fat in 109 obese men and women and 17 lean individuals. Some had diabetes but none had known heart disease.

“We found no inflammation in the fat of lean individuals,” who also had healthy blood vessel function, notes cardiologist Noyan Gokce of Boston University School of Medicine. In contrast, roughly 70 percent of the obese people had metabolic syndrome or at least some abnormal metabolic parameters in blood tests. These people also showed evidence of inflammation-promoting fat and impaired blood vessel function.

But the big surprise, Gokce says, was that the other roughly 30 percent of the obese people had very little inflammation inside their fat, little evidence of insulin resistance and vascular function that was the same as in lean people. “So it seems that the quantity of fat may not be nearly as important as its quality.”

The new data “open up the idea that maybe we should revisit subcutaneous fat as a major player in the metabolic consequences of obesity,” says Alyssa Hasty of Vanderbilt University School of Medicine in Nashville.

Found in: Body & Brain

View the original article here

News in Brief: Molecules

Tracking the source of wines’ deep reds, fish oil goes to the brain and more in this week’s news. Web edition : Sunday, September 4th, 2011

Red, red wine
Scientists can now tell whether a glass of deep red vino acquires its color from grapes or rice. Deep reds can attract a higher price and winemakers will sometimes blend wines with Rossissimo, a wine that’s extra rich in red pigment. In some markets pigments extracted from black rice are also used as “correctors,” but in Italy this practice is frowned upon. Reporting in the Sept. 9 Analytica Chimica Acta, Italian researchers report that high-end spectroscopic techniques can discern rice red from Rossissimo red. —Rachel Ehrenberg

Omega-3s down, suicide risk up
The heart-healthy omega-3 fatty acids found in fish oils might also help keep the head healthy. A new study finds that U.S. military personnel who were at high risk for suicide also had low levels of DHA, or docosahexaenoic acid, the major omega-3 used by the brain. The study does not establish cause and effect, but it adds to a growing body of evidence linking low levels of omega-3s with mood problems including depression. Researchers from the National Institutes of Health and the Uniformed Services University of the Health Sciences in Bethesda, Md., report the work online August 23 in the Journal of Clinical Psychiatry. —Rachel Ehrenberg

Wines’ notes
Descriptions of wine typically involve notes of fruit or musk, not piano or woodwind. But people do make associations between a wine’s scent and particular musical instruments, new research shows. When 30 study participants had to choose a sound to match a wine’s bouquet, five odors were consistently linked with particular instruments, scientists from the University of Oxford in England report in an upcoming Chemical Senses. Vanilla and apricot connoted woodwind and piano; blackberry also inspired primarily piano; and musky wines were linked to brass. —Rachel Ehrenberg

Found in: Molecules

View the original article here

FOR KIDS: Possible new saltwater stains on Mars

Dark streaks that grow in spring, fade in winter may point to saltwater on the Red PlanetWeb edition : Wednesday, August 31st, 2011 This image of a slope inside a Martian crater is actually a combination of several pictures taken by an instrument onboard the Mars Reconnaissance Orbiter. Scientists suspect the long, thin dark streaks are signs of saltwater that flows and then evaporates.HiRISE, MRO, LPL (U. Arizona), NASA

Here on Earth, it’s easy to find saltwater: Just head to the nearest sea. Oceans cover most of Earth’s surface, which means if you were to transport yourself to a random spot on our planet, you would probably end up all wet.

Visit the new Science News for Kids website to read the full story: Possible new saltwater stains on Mars

Found in: Science News For Kids

View the original article here

A lighter Higgs, but chase continues

Target narrows with new estimated mass for elusive particleWeb edition : Thursday, September 1st, 2011 An actual collision between two protons produces showers of particles whose paths and energies are recorded by the Large Hadron Collider’s CMS detector. This spray of electrons (thick red lines) and muons (thin red lines) looks similar to what would be expected from the Higgs, but could also be a background fluctuation.L. Taylor and T. McCauley/COPYRIGHT CERN 2011

In the hunt for the Higgs boson, the world’s most powerful particle collider has tightened the net. New data collected this year by CERN’s Large Hadron Collider near Geneva narrow the range of allowable masses for the hypothetical particle, whose existence would confirm the mechanism thought to give mass to other particles.

To fit with the standard model, the cornerstone of modern particle physics, the Higgs must now be lighter than 145 billion electron volts, or GeV. Team members from LHC’s ATLAS and CMS experiments presented their results August 22 in Mumbai, India at the International Symposium on Lepton Photon Interactions at High Energies.

This new limit goes beyond previous results from the Tevatron at the Fermi National Accelerator Laboratory in Batavia, Ill. — which directly excluded 156 to 177 GeV by looking for debris left behind when the Higgs breaks down, and indirectly ruled out masses above 185 GeV using theoretical calculations and measurements of other particles.

“We’ve now confirmed with direct searches that the mass of standard model Higgs, if it exists, is light,” says CERN’s Fabiola Gianotti, a spokeswoman for ATLAS.

Even as it runs out of room to hide, though, the Higgs is still playing hard to get. Faint hints of the Higgs that turned up at the LHC in July — particles with energies that could indicate a lighter Higgs — have only grown fainter in the new LHC data. No statistically significant signs of the Higgs have appeared in the rest of the remaining mass range.

A lighter Higgs is harder to find at the LHC. At lower energies, its signature tends to fade into the background. But CERN physicists still expect to discover or rule out the existence of such a particle in the next two years.

Found in: Atom & Cosmos and Matter & Energy

View the original article here

Saffron takes on cancer

Harvested from the Crocus sativus flower (shown), saffron stifles liver cancer’s growth in rats and even inhibits the proliferation of human liver cancer cells, a new study finds. KENPEI/Wikimedia Commons

Best known as a food seasoning and dye, saffron can also stifle liver cancer in rats, tests show. In a report in the September Hepatology, researchers find that the spice suppresses a slew of known cancer-related compounds and boosts several beneficial ones.

Saffron is an expensive spice made from the Crocus sativus flower. Past studies have hinted it has benefits against depression, inflammation, memory loss and as an antioxidant. Studies in animals and in human cells have even suggested that saffron can inhibit certain cancers. “But the exact mechanism of the anticancer effect of saffron is unclear,” says Amr Amin, a molecular biologist at United Arab Emirates University in Al-Ain.

Although the spice has been used as a folk remedy for centuries, only in recent decades has its value been tested in the laboratory. In the new study, Amin and his colleagues fed saffron to 24 rats daily for 24 weeks. Two weeks into the regimen the researchers injected the animals with diethylnitrosamine and 2-acetylaminofluorene, a chemical combination known to cause liver cancer.

Eight other rats getting a similar injection combo received distilled water instead of saffron. Six of them developed cancerous growths called nodules on the liver during the course of the study, whereas only four of the 24 rats getting saffron developed nodules. Of eight rats that got the highest dose of saffron, none developed any nodules.

Amin says his team chose to study liver cancer because cancers that spread from other organs, such as the colon or breast, often end up there.

Saffron kept in check a cell-proliferation protein called Ki-67 and reduced other compounds linked to liver damage and oxidative stress. Oxidative stress results from an imbalance between unstable, reactive molecules called free radicals and the antioxidants that sop them up. This tilt can lead to aberrant cell growth, a precursor to cancer, Amin says. Antioxidants, including one called superoxide dismutase, were restored in the rats getting saffron.

A separate series of tests on human liver cancer cells showed that saffron inhibits the action of key proteins — NF-kappa B, interleukin-8 and tumor necrosis factor receptor 1 — that contribute to cell proliferation and inflammation. Other evidence shows that saffron switches on programmed cell death in cancerous cells, a failsafe mechanism that is often shut down in cancer.

“This is very extensive work, and the quality is very good,” says Tapas Saha, a molecular biologist at the Georgetown University Lombardi Comprehensive Cancer Center. But Saha, who wasn’t involved in this study, says that scaling up these findings to apply them as a treatment in people might be a challenge. Saffron must be hand-picked, he notes, and so the price remains high. “Saffron is such a costly material,” he says, “that it’s very difficult to understand how it can be a drug.”

Synthetic versions of the important saffron components might be less expensive. Amin says further research may delineate those constituents.  Meanwhile, the team plans to test the spice in liver cancer patients.

Found in: Body & Brain

View the original article here

Middle school scientists recognized

Finalists in inaugural Broadcom MASTERS competition announcedWeb edition : Wednesday, August 31st, 2011

Thirty talented sixth-, seventh- and eighth-graders have raised the bar for the question, “Are you smarter than a middle schooler?” These science-minded youngsters have advanced to the final round of a new national competition, the first ever Broadcom Math, Applied Sciences, Technology and Engineering for Rising Stars program, or MASTERS event.

Finalists were chosen for their original research projects, which covered a range of scientific topics — from the cognitive benefits of yoga to the physics that gives light to LEDs. Following last year’s Deepwater Horizon oil spill, one student in Texas tested how oil and chemicals that disperse oil impact algae. Another used a computer simulation to investigate dark matter’s influence on rotating galaxies.

In October the selected students will travel to Washington, D.C., where they will present their projects to the public, visit Capitol Hill to meet members of Congress and vie for prizes in team challenges.

“Middle school is the time when a boy or girl first develops independent desires and interests,” says Paula Golden, executive director of Broadcom Foundation and director of community affairs for Broadcom Corp. “Engaging in a science or engineering project at this age may well ignite a passion that will inspire a middle schooler to stay with math and science.”

The 2011 Broadcom MASTERS is sponsored by the Broadcom Foundation and Society for Science & the Public, which publishes Science News. Past finalists of another competition administered by SSP — the annual Intel Science Talent Search for high school seniors — have gone on to win Nobel Prizes, among other accolades.

“In addition to launching science careers, SSP’s competitions motivate students to view the world through a scientific lens, essential for the navigation of issues that affect everyone in today’s complex global society,” says Elizabeth Marincola, president of SSP and publisher of Science News. 

In its first year, the Broadcom MASTERS program received 1,476 entries from students who were nominated by local science fairs in 45 states, Washington, D.C., and Puerto Rico. A panel of scientists and engineers whittled the applicants down to 300 semifinalists.

The selection of the 30 finalists on August 31 brought good news for the participating schools: Each winner’s school will receive $1,000 from the Broadcom Foundation. A single overall winner, to be announced at an October 4 gala, will receive the top prize, a $25,000 educational award presented by the Samueli Foundation, a private foundation based in Corona Del Mar, Calif.

2011 Broadcom MASTERS Finalists

ARIZONA
Meagen Bethel, Tucson, Doolen Middle School

CALIFORNIA
Namrata Balasingam, San Jose, Challenger School, Strawberry Park
Braden Benedict, Rancho Palos Verdes, Saint John Fisher Parish School
Daniel Feeny, Woodside, Woodside Elementary School
Crystal Poole, San Diego, Thurgood Marshall Middle School

FLORIDA
Maria Grimmett, Jupiter, The Weiss School
Nikhil Patel, Geneva, Stanford Middle School

HAWAII
Robert Heckman, Kailua, Kailua Intermediate School
Jordan Kamimura, Hilo, Hilo Intermediate School

MASSACHUSETTS
Nathan Han, Boston, Jackson Mann K-8 School
Emily Sarkisian, Mansfield, St. Mary’s Catholic School

MINNESOTA
Roshini Asirvatham, Rochester, Friedell Middle School
Carolyn Johns, Eden Prairie, Central Middle School

NORTH CAROLINA
Justin Barber, Raleigh, St. Timothy’s School
Chad Campbell, Hampstead, Topsail Middle School

NEW MEXICO
Coleman Kendrick, Los Alamos, Los Alamos Middle School

OHIO
Kyle Davis, Sunbury, Big Walnut Middle School
Jennifer Markley, Westerville, Walnut Springs Middle School
Samantha Rowland, Tipp City, Tippecanoe Middle School

OREGON
Valerie Ding, Portland, Summa North at Meadow Park Middle School
Anirudh Jain, Portland, Summa North at Meadow Park Middle School
Mahita Tovinkere, Portland, Stoller Middle School

PENNSYLVANIA
Benjamin Hylak, West Grove, Sacred Heart School

PUERTO RICO
Adriana Monzon, Guaynabo, Academia del Perpetuo Socorro

SOUTH CAROLINA
William White, Hilton Head, Hilton Head Preparatory School

TEXAS
Ria Chhabra, Plano, Renner Middle School
Alicia D’Souza, Plano, C.M. Rice Middle School
Lauren Hall, Corpus Christi, School of Science and Technology
I-Chun Lin, Plano, Schimelpfenig Middle School

WASHINGTON
Katherine Landoni, Sequim, Sequim Middle School

Found in: Science & Society and Science News For Kids

View the original article here

Oldest hand axes found

African discoveries offer glimpse of early tool-making complexityWeb edition : Thursday, September 1st, 2011 OLD AND EDGYA stone hand ax (shown from different angles), dating to 1.76 million years ago, comes from the earliest known culture to have made such implements.P.-J. Texier, copyright MPK/WTAP

A patch of soil in East Africa has yielded the oldest known stone hand axes and picks, examples of what researchers call the Acheulian industry.

Acheulian implements unearthed at Kenya’s Kokiselei site date to 1.76 million years ago, slightly older than previous finds (SN: 1/31/09, p. 11), say geologist Christopher Lepre of Rutgers University and his colleagues. Carefully shaped, double-edged hand axes and picks lay among much simpler tools — sharp flakes pounded off stones — at Kokiselei, the scientists report in the Sept. 1 Nature.

These finds underscore suspicions that stone flakes used as chopping devices, early tools known as the Oldowan industry, did not get supplanted by hand-ax making, Lepre says. Instead, the more complex Acheulian devices emerged while Oldowan implements — which first appeared about 2.6 million years ago in the same region — were still popular, although it’s unclear how long the two types of tools were used simultaneously at Kokiselei. Hand axes and other double-edged tools typify the Acheulian industry.

Homo erectus, a possible direct ancestor of modern humans, made Acheulian tools and perhaps Oldowan ones as well at Kokiselei, Lepre’s team suggests. Or, another hominid species might have crafted Oldowan artifacts there.

“If Acheulian tools gave hominids an edge in Africa, then perhaps groups lacking that technology were forced to find resources elsewhere, like Eurasia,” Lepre says.

In line with that proposal, other researchers have unearthed H. erectus fossils at Dmanisi, a West Asian site as old as Kokiselei, along with simple chopping stones but no hand axes. It remains unsettled whether H. erectus, which first appeared around 2 million years ago, evolved in Africa or Asia.

Lepre’s team estimated the age of the Kokiselei tools by taking measurements in and around artifact-bearing soil of ancient reversals in Earth’s magnetic field, combined with previously dated volcanic ash layers sandwiching the finds.

Archaeologists familiar with the new paper say that it moves the origin of Acheulian tools back a bit closer to the evolutionary debut of H. erectus, an interesting but not unexpected development.

Excavations at Israel’s 'Ubeidiya Formation have recovered 1.5 million-year-old hand axes and picks, presumably made by H. erectus, that resemble those from Kokiselei, remarks Naama Goren-Inbar of the Hebrew University of Jerusalem. Acheulian sites in Tanzania and India also date to as early as 1.5 million years ago.

Some sets of Oldowan and Acheulian artifacts look much alike, implying that the same hominid species could have produced both tool types, Goren-Inbar says.

Harvard University’s Ofer Bar-Yosef agrees. “Homo erectus could have made all of the stone tools at Kokiselei,” he asserts.

Fossils are needed to confirm that H. erectus made these implements, comments John Shea of Stony Brook University in New York. Simple flakes struck off stones augmented more complex tools throughout the Stone Age, although archaeologists often ignore Oldowan artifacts at modern human sites, Shea argues.

Found in: Anthropology, Archaeology and Humans

View the original article here

News in Brief: Earth & Environment

The supercontinent of the future, pollutants from laundry detergent and more in this week’s news Web edition : Saturday, September 3rd, 2011

Clouds intensify soot’s Arctic heating
Reining in soot production could dramatically slow Arctic warming, Mark Jacobson of Stanford University reported August 31 in Denver at the American Chemical Society’s national meeting. Soot’s presence in water droplets heats clouds much more than it does the black carbon particles between cloud droplets, new computer analyses show — which Jacobson says “helps to explain the burning off of clouds in polluted regions.” Once clouds disappear, more sunlight reaches the surface to melt sea ice and warm Arctic waters. But curbing all soot that now wafts into the Arctic could within 15 years eliminate 15 to 20 percent of the total warming contribution to the region, which could reduce the net temperature rise by 50 percent, his computer projections indicate. —Janet Raloff

Bedrock can help the climate
Researchers from the University of California, Davis offer data that could overturn the conventional wisdom about where new nitrogen in land-based ecosystems comes from. It’s supposed to come from the atmosphere. Butforests and local soils underlain with nitrogen-rich sedimentary rock contain 50 percent more nitrogen, a fertilizer, than do those atop nitrogen-poor rock, the scientists report in the Sept. 1 Nature. These researchers fingerprinted the bonus nitrogen to the weathering of bedrock below. Forests and soils over nitrogen-releasing rock also contained substantially more carbon than in nitrogen-poor areas, the scientists found, demonstrating that bedrock can dramatically boost the carbon-sequestering climate benefits of some forests. —Janet Raloff

Clean-smelling clothes dirty the air
Fragrance chemicals in detergents and dryer sheets can release toxic chemicals — none listed on product labels — especially into the air vented from a dryer. Anne Steinemann of the University of Washington in Seattle and her colleagues did laundry using no products, scented detergents, and detergents plus dryer sheets. The researchers report online August 19 in Air Quality, Atmosphere & Health finding substantial quantities of airborne organics including seven chemicals considered hazardous, two of which are potential carcinogens: acetaldehyde and benzene. Acetaldehyde measurements, if extrapolated to all users of the top five detergent brands throughout the county, could equal 6 percent of that toxic chemical’s releases from area cars if all the detergents produce the same levels the test detergent did, the researchers calculate. —Janet Raloff

Triggering earthquakes
Injecting carbon dioxide deep underground to keep it from entering the atmosphere can trigger earthquakes on local faults, a new study suggests. Scientists from the Lawrence Berkeley National Laboratory in California and the Côte d’Azur Observatory in France simulated what would happen if carbon dioxide entered an underground reservoir with a common kind of fault nearby. Depending on how and when the injection was done, an earthquake of up to magnitude 4.5 could occur, the team reports in a paper to appear in Geophysical Research Letters. Oil exploration, geothermal and other companies want to understand the conditions under which injections cause earthquakes. —Alexandra Witze

Supercontinent of the future
Continental drift, combined with heat from deep within Earth, could push North America, Eurasia, Australia and Africa together to form a new supercontinent in the Northern Hemisphere within the next 250 million years. Although scientists know about past supercontinents such as Pangaea, speculating about future landmasses has been something of a guessing game. Now, scientists in Japan have modeled heat welling up from Earth’s mantle and suggested exactly how that could drive today’s continents together. Antarctica and South America never join the future supercontinent, the team reports online August 17 in Terra Nova. —Alexandra Witze

Found in: Earth and Environment

View the original article here

News in Brief: Life

Bird marriages hurt by city hubbub, tadpoles poison their own kind and more in this week's newsWeb edition : Thursday, September 1st, 2011 TURTLE TRACKINGHawksbill turtles like the one shown here are surprising researchers by heading into forested estuaries instead of reef waters.Aquaimages/Wikimedia Commons

Hawksbill turtles in funny places

Tracking imperiled hawksbill turtles in the eastern Pacific with satellite tags has left turtle biologists startled by locations in completely unexpected places. In the Caribbean and Indo-Pacific regions, hawksbills cruise reefs and waters near shore that face open ocean. Yet tag data revealed most of the 12 female turtles followed along the Pacific coast of El Salvador, Honduras, Nicaragua and Ecuador were hanging out in shallower waters such as inshore estuaries and seemed to especially like mangrove forests. Turtle conservation strategies need rethinking, an international research team reports online August 31 in Biology Letters. —Susan Milius

Urban noise ruined my marriage

Traffic rumbling and other urban noise that prompt males of a European bird species called the great tit to cut back on sexy, low-pitched morning serenades may lead to more philandering by their female partners. In the latest twist in studies on how human noise affects city-dwelling animals, researchers at Leiden University and Gronigen University in the Netherlands experimented with sound and song at tit nest boxes. Female birds preferred deeper voices, and males that didn’t croon low as much were more likely to be cuckolded than those that did, Wouter Halfwerk and his colleagues report Aug. 30 in  Proceedings of the National Academy of Sciences. —Susan Milius

Tadpole-on-tadpole WMD

A new avenue for research on chemicals to control the massive, poisonous cane toads that are spreading across Australia has come from the tadpoles of the species. Chemical cues that the tadpoles release into the water can suppress the development of cane toad embryos still in eggs such that they hatch into punier tadpoles that don’t survive or grow well, report researchers from the University of Sydney online August 31 in Biology Letters. The toads, introduced in a regrettable attempt to control another pest, are disrupting the native ecosystems. —Susan Milius

Found in: Life

View the original article here

News in Brief: Humans

Humans and Neandertals may not have interbred, after all, the backlash of selfishness and more in this week's news

No Neandertal hanky-panky
New mitochondrial DNA analyses indicate that Neandertals didn’t occasionally interbreed with Stone Age humans, as proposed in a recent study of Neandertal nuclear DNA, say evolutionary biologist Guido Barbujani of the University of Ferrara in Italy and his colleagues. Barbujani’s team analyzed maternally inherited mitochondrial DNA from European Neandertals, Stone Age Europeans and living Europeans. If nuclear DNA lines leading to Neandertals and Europeans are older than corresponding mitochondrial DNA lines, then a long period of shared ancestry could explain why Neandertals and today’s Europeans share some nuclear DNA, the researchers propose online August 24 in the American Journal of Physical Anthropology. —Bruce Bower

Psychling dynamics
Although cyclist Alberto Contador won the 2009 Tour de France, he was criticized for defecting from his teammates and sprinting ahead when tactics demanded patience. A new analysis suggests that criticism was on mark. When strong riders break away from their companions, it helps the defector but hurts the team, researchers report in an upcoming issue of Complexity. University of Colorado at Boulder scientists and a sports psychologist from a professional team developed a bike racing model incorporating variables such as cooperation, defection, speed, distance and effort. The model nicely captures real racing dynamics: below-average riders fare better as defectors, above-average riders as cooperators, and when a strong rider does defect, it really screws his team. —Rachel Ehrenberg

Depression-fighting beliefs
Strong religious and spiritual beliefs may defend against recurrences of depression, especially if this mood disorder runs in a person’s family. Among individuals tracked for 10 years, those who considered religion and spirituality important in their lives displayed a markedly lower rate of major depression than those who didn’t, say psychologist Lisa Miller of Columbia University in New York City and her colleagues. Religion’s protective effect was greatest for those who had depressed mothers, the researchers  report online August 24in the American Journal of Psychiatry. Most of those high-risk individuals had been treated for bouts of depression before the study began. —Bruce Bower

Neandertals’ varied menu
Often portrayed as meat-obsessed big-game hunters, Neandertals may have had broader tastes. Neandertals that lived in southern France between 250,000 and 125,000 years ago ate fish, birds and starchy plants as well as wild cattle,  deer and wild horses, two anthropologists report online August 24 in PLoS ONE. Microscopic residue and edge-wear patterns on Neandertal stone tools previously unearthed at a French site called Payre reveal a varied diet that may have been missed in previous studies of butchered animal bones, say Bruce Hardy of Kenyon College in Gambier, Ohio, and Marie-Hélène Moncel of the National Museum of Natural History in Paris. —Bruce Bower

Found in: Humans

View the original article here

Acid oceans helped fuel mass extinction

The question of what killed most life on Earth 250 million years ago is a veritable Murder on the Orient Express, with multiple characters all dealing part of the deathblow. Now, scientists have learned how one of the assassins — acid — could have performed its part of the deed.

High levels of atmospheric carbon dioxide would have turned the oceans more than acidic enough to kill off marine critters, a computer simulation indicates.

“This would have been another stressor in the system that might have pushed things toward extinction,” says Alvaro Montenegro, a climate modeler at St. Francis Xavier University in Antigonish, Nova Scotia. He and his colleagues describe the finding in a paper published online August 2 in Paleoceanography.

At the end of the Permian period of geologic time, more than 90 percent of marine species and three-quarters of terrestrial species vanished. Leading suspects in the die-off include oxygen-starved oceans, a belch of hydrogen sulfide from the deep, a shutdown of great marine nutrient cycles, and massive volcanic eruptions.

Using a climate model developed at the University of Victoria, Montenegro and  colleagues set up nine hypothetical worlds — mixing and matching possible continental arrangements, seafloor topographies and levels of atmospheric carbon dioxide. Then the researchers fired up the model and watched how carbon flowed through the ocean and atmosphere.

At atmospheric carbon dioxide levels of 3,000 parts per million — roughly 10 times modern preindustrial levels — much of the gas dissolved in seawater, forming carbonic acid and releasing hydrogen ions. Acidity is measured on the pH scale; the lower the number, the more acidic the waters. Today’s oceans have a pH of around 8.1; those in the modeled end-Permian world dropped to around 7.3 near the equator and 7.1 near the poles. Such acidity would have made it hard for many marine organisms to use calcium carbonate to build protective shells, Montenegro says.

Today’s oceans also are growing more acidic because of carbon dioxide belched into the atmosphere by fossil fuel burning and other sources. Back then, most of the gas probably came from huge volcanic eruptions in Siberia.

How quickly carbon dioxide built up in the atmosphere would have affected how acidic the ocean got, says Jonathan Payne, a paleobiologist at Stanford University. If gas concentrations increased quickly, he says, “then this model may be a reasonable representation of how climate was changing at the time.” If gas built up slowly, the oceans may have been able to buffer the change in other ways.

But the model doesn’t include factors such as carbon weathering off land surfaces and into the oceans — an important player in the carbon cycle, says Lee Kump, a modeler at Pennsylvania State University in University Park. Including such effects, he says, could better show how life’s worst extinction came to pass.

Found in: Earth, Life and Paleobiology

View the original article here

News in Brief: Genes & Cells

Bacterium’s DNA mostly unused, the death of Black Death and more in this week’s newsWeb edition : Friday, September 2nd, 2011

Life’s essentials
Most of the DNA in the bacterium Caulobacter crescentus really isn’t necessary. Researchers used genetic tricks to map out the pages of the bacterium’s genetic instruction book that are essential to life in the lab. Of Caulobacter’s 3,876 genes, only 480 are essential, Stanford microbiologist Lucy Shapiro  and her colleagues report online August 30 in Molecular Systems Biology. Also necessary are 402 pieces of DNA that govern activity of genes and 130 pieces of DNA that don’t encode proteins. Of the 130 “non-coding” bits, “90 don’t fit any of the categories we know about, and we don’t have a clue what they do,” Shapiro says. —Tina Hesman Saey

Black Death bacterium is extinct
Fear not. A version of the plague bacterium that wiped out at least 30 percent of Europe’s population between 1347 and 1351 is a goner. Scientists have debated whether the plague bacterium Yersinia pestis really caused the Black Death because that plague had different symptoms than modern outbreaks of bubonic or pneumonic plague. Now scientists from the University of Tübingen in Germany and McMaster University in Canada and colleagues have found traces of Y. pestis in skeletons of Black Death victims. The team reports online August 29 in the Proceedings of the National Academy of Sciences that the Black Death bacterium was genetically different from modern plague strains and probably no longer exists. —Tina Hesman Saey

Yellow eyes get less sleep
Elderly people’s sleeping problems may be due to a natural yellowing of the eyes with age, a new study suggests. Researchers at the University of Copenhagen examined 970 Danish people between 30 and 60 years old. The team found that as people age, the lenses of their eyes yellow slightly, blocking out blue light wavelengths that help synchronize the body’s daily rhythms. The less blue light that got through to the retina, the more likely people were to have sleep disturbances, the researchers report in the Sept. 1 Sleep. Yellowing is sped up in smokers and people with diabetes and heart disease. —Tina Hesman Saey

Ancient antibiotic resistance
People have been fighting bacteria with antibiotics for more than 70 years, but a new study finds that the microbes have had at least a 30,000-year head start on building resistance. The finding, published online August 31 in Nature, contradicts the idea that resistance to antibiotics is a modern phenomenon brought about by misusing the drugs. Researchers at McMaster University in Hamilton, Canada, and colleagues isolated ancient DNA about 30,000 years old from the permafrost near Dawson City, Canada, and found genes for proteins that work together to inactivate the antibiotic vancomycin. Resistance to that antibiotic was previously thought to have first arisen in the late 1980s. —Tina Hesman Saey

Found in: Genes & Cells

View the original article here

News in Brief: Genes & Cells

A family without fingerprints and the long-term harm of sleep skimping in this week’s news Web edition : Friday, August 19th, 2011

No fingerprints
Members of a Swiss family who lack fingerprints have a mutation in a gene called SMARCAD1, Eli Sprecher of Tel Aviv University in Israel and colleagues report. The mutation, which also reduces the density of sweat glands in the hands, leads to a problem with a version of the gene’s protein that is made only in the skin, the team writes in the August 12 American Journal of Human Genetics. The researchers don’t yet know whether the gene is involved in creating the pattern of fingerprints or just in building the skin ridges that make up the print. —Tina Hesman Saey

Chronic sleep loss can cause permanent harm
Repeatedly skimping on sleep can add up to permanent health damage, a new study in rats suggests. Carol Everson and Aniko Szabo of the Medical College of Wisconsin in Milwaukee restricted rats’ sleep in repeated 10-day bouts, with two days in between to rest up. The rats lost weight despite chowing down on far more food and water than usual. The animals’ hormones were messed up, and they developed other problems as well, the researchers report August 11 in PLoS ONE. Even after four months of recovery, the rats still had hormone imbalances and were eating 20 percent more and drinking 35 percent more than rested rats. —Tina Hesman Saey

Found in: Genes & Cells

View the original article here

Antidepressants show signs of countering Alzheimer’s

Mice and human data link treatment to less plaque in the brainWeb edition : Monday, August 22nd, 2011

Widely used antidepressants may reduce the ominous brain plaques associated with Alzheimer’s disease, a new study in mice and humans finds.

Brain scans of people who have taken antidepressants reveal fewer clumps of the protein amyloid-beta, a target of Alzheimer’s prevention strategies, when compared with people who have not taken the drugs.

Many in the field voiced caution about the results. But if borne out by further study, the findings may point to a new, relatively safe way to treat and prevent Alzheimer’s disease, which is the sixth leading cause of death in the United States.

“I think this is a wonderful piece of news, and I think there’s going to be a lot of excitement about this,” says internist Michael Weiner, who leads the Alzheimer’s Disease Neuroimaging Initiative at the Veterans Affairs Medical Center campus of the University of California, San Francisco. “It points the way towards a possible approach to treating Alzheimer’s disease that people have not been talking about very much.”

In the study, mice genetically engineered to overproduce amyloid-beta, or A-beta, were given one of three selective serotonin reuptake inhibitors, a class of antidepressants that boost circulating levels of the chemical messenger serotonin in the brain. After a single dose of the antidepressants, A-beta levels dropped in the fluid that surrounds mouse brain cells, researchers report online the week of August 22 in the Proceedings of the National Academy of Sciences. A full day after receiving the drug, the mice’s A-beta levels fell by nearly a quarter.

Long-term, chronic administration of the drug had a larger effect. Engineered mice that took the SSRI citalopram for four months had about half the A-beta plaques in their brains as mice that hadn’t had the drug. This reduction seems to happen through a protein called ERK, which serves as the middleman between brain cells’ serotonin-sensing proteins and A-beta production.

Figuring out the details of this process may open the door for developing new ways to prevent A-beta buildup, says study coauthor John Cirrito of the Washington University School of Medicine in St. Louis.

To see if a similar effect might be happening in people, the scientists scanned the brains of 186 cognitively normal elderly people and looked for signs of A-beta plaques. The team used a compound called PIB that binds to big clumps of A-beta in the brain and glows on a PET scan.

Of these participants, 52 reported that they had taken an antidepressant in the last five years. These people, researchers found, had about half the A-beta load in their brains as the people who hadn’t taken an antidepressant. What’s more, the length of time the participants took the drugs correlated with the density of A-beta plaques in the brain — the longer the antidepressant dose, the less plaque.

“We think there are influences going in two opposite directions,” says study coauthor and psychiatrist Yvette Sheline, also of Washington University. “We think depression pushes you toward dementia, but antidepressant treatment pushes you toward protection.”

Finding similar results in mice and humans lends the study credibility, Weiner says. “When you have animal data and human data coming together, then you start to get really excited,” he says.

Still, Weiner and others caution that it would be premature to conclude that antidepressants protect against A-beta buildup or that fewer plaques necessarily translate into less disease.

The study uncovered an association — not a clear-cut cause and effect, Weiner notes. “We cannot say with certainty that the reason why people who took the SSRIs have lower cortical amyloid is due to the fact that they took SSRIs,” he says.

And molecular neuroscientist Heather Snyder of the Alzheimer’s Association in Chicago points out that even if antidepressants are shown to reduce A-beta, scientists still don’t know how A-beta levels affect the brain. “We don’t really know what modulating amyloid will do to cognition,” she says. “And we don’t know if we need to reduce it by 10 percent or 20 percent, or if it needs to be completely reversed.”

Another confounding factor is that A-beta can take several forms in the brain, from small molecules to large, sticky clumps, and some forms may be more dangerous than others. Interpreting the A-beta clumps that PIB detects in human brain scans remains challenging.

“We’re being very cautious,” Cirrito says. “There are a lot of people on these drugs and we don’t want to get anybody overly excited without reason.” He and his colleagues plan to test whether acute doses of SSRIs change A-beta levels in the cerebrospinal fluid of healthy human subjects.

Even if the new findings are replicated in larger studies, a major question about Alzheimer’s and antidepressants remains, Sheline says. “The real question is — which this paper sheds no light on — does that mean that long-term, they [SSRI-treated people] will have less of a risk of dementia? And that’s exactly the big study that needs to be done.”

Found in: Body & Brain and Genes & Cells

View the original article here

News in Brief: Molecules/Matter & Energy

Metamaterial warp drives, secrets of coffee rings and more in this week's newsWeb edition : Sunday, August 21st, 2011

Toy warp drive proposed
A physicist who previously created a toy universe out of metamaterials that bend light in unusual ways has now dreamed up a way to use those materials to build a warp drive. Simulations by Igor Smolyaninov at the University of Maryland in College Park show that moving faster than light is still impossible in toy universes, just as it is in the real one. But the right material should allow superspeed travel at up to one-quarter light speed — by riding in a moving spacetime bubble, he reports in an upcoming issue of Physical Review B. —Devin Powell.

Butterflies sip like sponges
To sip nectar, a butterfly uses a proboscis that looks like straw but also works like a sponge. At the small scales of butterfly existence, liquid is just too thick to be slurped, a team led by researchers at Clemson University in South Carolina reports. X-ray images of butterfly feeding tubes reveal pores that draw fluid upward by capillary action, the same process that pulls water through a paper towel. This anatomy may help butterflies dine on a greater variety of foods, and its principle could be borrowed to design probes that sample the liquid inside cells, the researchers report online August 17 in the Journal of the Royal Society Interface. —Devin Powell.

Coffee ring regulation
Starbucks tables everywhere rejoice: There’s a way to prevent the coffee ring effect. The quiet drying of spilled coffee on a countertop produces a crusty edge because round particles flee in a frenzy from the center of the spill. But oblong particles in the liquid can’t flee that well and end up spreading out uniformly, University of Pennsylvania scientists report in the Aug. 18 Nature. Upping the number of elongated particles compared to spherical ones can prevent ring formation, suggesting that particle shape influences fluid interactions. The finding could help in designing better inks, paints and even foams and lotions.—Rachel Ehrenberg

Found in: Matter & Energy and Molecules

View the original article here

News in Brief: Body & Brain

Leukemia gene therapy, the brain tickle of beautiful voices and more in this week's newsWeb edition : Thursday, August 18th, 2011

Gene therapy for leukemia
Tweaking immune cells to attack cancer cells in leukemia patients can bring about remission, a small study shows. Scientists at the University of Pennsylvania genetically altered immune T cells to target malignant cells in chronic lymphocytic leukemia patients and mass produced the T cells before injecting them into three patients. The modified cells gravitated to bone marrow, where they killed malignant cells. In two of three patients tested the cancer went into remission, and a portion of the genetically modified T cells persisted, possibly as a cadre of defenders on standby. The researchers report the findings in the Aug. 10 Science Translational Medicine. —Nathan Seppa

Gout drug lessens flares
A drug approved in 2010 for treatment of gout has proved its worth, reducing symptoms over six months in many people who had failed to get relief from standard medications. The routine therapy for gout fails in about 3 percent of the 5 million to 6 million people in the United States who have it. A drug called pegloticase, which is given by intravenous infusion over two hours, gained approval last year for chronic gout. Two clinical trials in the United States, Canada and Mexico of people who had failed to improve? on standard drugs now show that of 65 of 169 patients getting pegloticase (Krystexxa) every two or four weeks for six months had reduced uric acid in the blood, a standard measure. The biweekly group had better symptom reduction. —Nathan Seppa

Live longer with exercise
Just 15 minutes of moderate daily exercise seems to extend life. A team of U.S. and Taiwanese researchers kept track of physical activity levels in more than 400,000 adults age 20 and older in Taiwan using questionnaires. Compared with sedentary people who didn’t exercise, those putting in 92 minutes a week — 15 minutes a day on average — were 14 percent less likely to die over an average follow-up period of eight years. The benefits applied to both sexes and to all age groups, the researchers report online August 16 in the Lancet.  —Nathan Seppa

Granddaddy’s stress changes grandson’s brain
What your grandfather experienced in the womb may change your brain. Grandfather mice who were stressed out in utero went on to produce grandsons with more feminine brains, a study in the Aug. 17 Journal of Neuroscience shows. In male descendents of stressed-out grandfathers, genes important for brain development switched their behavior to become more like the gene activity in female mice’s brains. These results may offer a way to link stress and neurological disorders that strike males and females differently, such as autism spectrum disorders, Christopher Morgan and Tracy Bale of the University of Pennsylvania write in the study. —Laura Sanders

Beautiful voices tickle the brain
From Laura: Attractive voices tickle the part of the brain that normally handles visual input, a new study finds. In the study, participants listened to different voices saying “had” and later rated how attractive the voices were. Voices rated more attractive were associated with greater brain activity in a region near the part of the brain that responds to faces, an international team of scientists reports in an upcoming Cerebral Cortex. That the brain detects and responds to vocal beauty suggests that people may be tuned in to hidden, nonverbal forms of communication. —Laura Sanders

Why autistic brains confuse pronouns
The brains of people with autism behave abnormally when grappling with pronouns such as “you” and “I.” While answering a question that contained the word “you,” adults with autism had a weaker connection between two key brain regions than unaffected participants, Akiko Mizuno of Carnegie Mellon University in Pittsburgh and colleagues report in an upcoming Brain. This weak brain connection vanished when the question omitted pronouns and instead used people’s names. The results help explain why children with autism often have trouble with the concept of self-identity, sometimes referring to themselves as “you.” —Laura Sanders

Found in: Body & Brain

View the original article here

News in Brief: Humans

Prehistoric assembly lines, a trigger for riots and more in this week's newsWeb edition : Monday, August 22nd, 2011

Early start for advanced tools
Large-scale production of sophisticated stone tools, using standardized assembly steps, emerged a surprisingly long time ago. Between 400,000 and 200,000 years ago, unidentified members of the genus Homo regularly made slender, sharp-edged blades and other animal-butchery implements at Qesem Cave in what’s now Israel, say archaeologist Ron Shimelmitz of Tel Aviv University and his colleagues. Analyses of thousands of Qesem stone artifacts, and experimental reproductions of these finds, indicate that the implements were made in stages requiring as much planning as Neandertal tools that didn’t appear until 200,000 years ago, the researchers will report in the Journal of Human Evolution.  —Bruce Bower

A fate worse than death
Patients in persistent vegetative states often get tagged as having less mental capacity than the dead. Ending up in biological limbo is also regarded as a fate worse than death, say psychologist Kurt Gray of the University of Maryland in College Park and his colleagues. Religious and non-religious participants alike attributed less mental activity to vegetative patients than to the dead, due to afterlife beliefs and a tendency to assume that deceased but unseen people still have minds, the scientists will report in Cognition. Religious people also usually advocated life support for vegetative patients despite regarding such states as worse than death. —Bruce Bower

Food fights
Violent protests in North Africa and the Middle East in 2008 and 2011 coincided with large spikes in global food prices, a new study shows. The analysis, which spans January 1990 to May 2011, suggests that high global food prices are a precipitating condition for social unrest, say Yaneer Bar-Yam and colleagues at the New England Complex Systems Institute in Cambridge, Mass. Their study, posted at arXiv.org on August 11, also calculates a food price threshold above which vulnerable populations typically find themselves in desperate straits. This indicator could help guide policy interventions.—Rachel Ehrenberg

Found in: Humans

View the original article here

Science & the Public: Blacks far less likely than whites to land NIH grants

Among minority scientists applying for National Institutes of Health research grants, blacks alone face a substantially lower likelihood of being successful than whites, a new study finds. This investigation, which was prompted by the research agency itself, will catalyze further probes and a host of changes, promises NIH director Francis Collins.

The findings emerge from a study published online Aug. 18 in Science. Donna Ginther of the University of Kansas in Lawrence and her colleagues probed the success rates of Ph.D. investigators working at U.S. institutions in winning NIH grants between 2002 and 2006. Over that time, more than 40,000 individuals submitted a total of 83,188 applications. Each hoped for the opportunity to dip deeply from a pool of funds averaging about $1.4 billion annually.

Researchers who described themselves as Hispanic had grant success rates comparable to whites. Initially, Asians appeared to have a 4 percentage-point lower success rate than whites. But when Ginther’s group reanalyzed the data, restricting the applicants to U.S. citizens, the Asian disadvantage vanished. (Says Collins, this suggests that applicants who didn’t fare well here might have been non-native English speakers with a language barrier to articulating their ideas cogently.)

But nothing erased the black disadvantage, Ginther’s team found.

“These data are deeply troubling,” Collins says. “Even after controlling for all of the factors that were considered to be important for predicting success” — like education and NIH training, the labs in which they ended up working, the number of research papers they’ve authored — “black applicants were 10 percentage points less likely than white applicants to receive research grants.”

Numerically, he told reporters, that translates to about 27 percent of white researcher’s grant applications winning funding, compared to only about 17 percent of those submitted by blacks.

“It is certainly a situation that we all agree is unacceptable and requires intervention,” Collins says.

On the drawing board
He and Lawrence Tabak, the principal deputy director of NIH, broadly outline an action plan to deal with the problem in a report that also appears online in Science. Details, however, await the findings of a pair of new advisory groups that Collins created.

Tabak co-chairs one of these: a diversity in biomedical research working group. He reports that in its initial teleconference, the group discussed how to probe obstacles to the recruitment of first-rate applications from minority scientists and to ensure that those proposing the best science have an equally high chance of landing NIH funds.

“This is a committee that is not designed to produce a glossy report that will sit on shelves,” Tabak says, but rather to provide Collins “tangible action items” by next June.

One issue NIH plans to take on immediately: how to adequately “blind” grant reviewers to applicants so that any chance of bias is minimized — without also eliminating important details that might reflect the quality of a scientist’s research or resources.

NIH already strips off a researcher’s stated race or ethnicity from a grant proposal before reviewers judge its merit. However, names and the background of the principal investigator remain — which in some instances may offer clues. Such as a first name like Kwame or L’Shaniqua, or perhaps reference to an applicant having attended a historically black college.

In an experiment set to begin soon, Collins promised to investigate whether further blinding is needed. His agency will simultaneously subject some collections of grant applications to two review panels, then compare their results. One panel will receive applications that contain the same information as in the past; the other will receive proposals from which all names and identifying characteristics have been removed.

Boosting help, enriching opportunities
While the magnitude of the black disadvantage might have surprised NIH, the agency has long known that blacks play a bit role in biomedical research. They constitute 10.2 percent of the U.S. population, Collins notes, yet only 1.2 percent of researchers leading projects financed by NIH (through investigator-led — or RO1 — grants).

The newly quantified disadvantage highlighted by Ginther’s team might reflect weaker training of black researchers on how to craft a winning application, less access to mentoring on research design, some subtle bias on the part of grant-review committees — or a combination of all these. Collins vows his new advisory groups will look into each.

For instance, not all grant applications are scored for quality. Those that reviewers feel will fall within the lower half are just rejected.

Ginther’s group now reports that among grant proposals that were scored highly, race and ethnicity had no impact on funding success. This suggests that blacks may face some disadvantage in drafting a compelling proposal.

Collins now promises NIH will soon offer extra assistance to inexperienced grant applicants and be “supporting innovative approaches to encourage more extensive and effective local mentoring of junior faculty” by the academic institutions at which they work. He adds that his new advisory groups will also consider how NIH might encourage researchers who weren’t successful the first time around to reapply for a grant (since most successful applicants have to try a few times before they land a grant — and blacks are less likely to do that).

Sitting in on grant deliberations should help young faculty of all ethnic backgrounds get a better taste of how research proposals are judged and what’s most likely to wow their peers. Scientists recruited to review grants, however, tend to be older, more experienced individuals. Collins aims to change this by actively recruiting “promising junior faculty” to become reviewers: “We aim to have 50 of these early career reviewers assigned to each of NIH’s three rounds of grant reviews in the 2012 fiscal year, which begins Oct. 1."

At a briefing for reporters, Tabak noted that NIH has already begun sharing what it’s learned with officials at the National Science Foundation, Department of Defense, Energy Department and Education Department. From those discussions, he says, it sounds like these agencies are also open to investigating whether racial or ethnic disparities may exist among applicants for their grants.

Found in: Biomedicine and Food Science

View the original article here

News in Brief: Atom & Cosmos

Getting to supernova
White dwarf stars often don’t waltz together when they die. A new survey of 41 “Type Ia” supernovas, the explosions these dwarfs die in when they suck too much material off another star, found sodium gas flowing away from many of the explosions. But white dwarfs are mostly made of carbon and oxygen, so the sodium gas was probably thrown off by an ordinary or giant star. That suggests that the dwarfs weren’t eating their own kind. Knowing how Type Ia supernovas form is important because astronomers use their brightness to help measure cosmic distances. An international team of researchers reports the discovery in the Aug. 12 Science. —Alexandra Witze

Sunspots rising
Magnetic fields lurking deep beneath the sun’s surface could signal the imminent emergence of sunspots. Using the Solar and Heliospheric Observatory satellite, scientists have spotted such fields, much stronger than models had predicted, up to 65,000 kilometers below the surface. Over the course of a day or two, the magnetic disturbances rise upward and eventually trigger the formation of sunspots. Knowing sunspots are coming could help people better prepare for telecommunications and other outages caused by space weather, Stathis Ilonidis of Stanford University and colleagues write in the Aug. 19 Science. —Alexandra Witze

Found in: Atom & Cosmos

View the original article here

Butterfly species a master of disguise

Tasty Heliconius numata butterflies (right) mimic the wing patterns of foul-tasting Melinaea butterflies (left) to avoid getting eaten. Genetic tricks using a supergene allow the butterflies to faithfully masquerade as other species. © Mathieu Joron

The tasty Heliconius numata butterfly evades predators by copying the wing patterns of foul-tasting Melinaea butterflies. H. numata, also known as the passion-vine butterfly, has to get the pattern exactly right or a sharp-eyed bird will spot the fake and gobble it up.

Born mimics, members of the species lock in wing patterns with flipped-around bits of DNA, Richard ffrench-Constant of the University of Exeter in England and colleagues report online August 14 in Nature.

The flipped DNA causes six or more genes — on a section of a chromosome important in setting wing patterns in butterflies and peppered moths — to be inherited as a single unit, a supergene. Different versions of the super­gene allow H. numata to adopt seven different wing patterns reminiscent of several bad-tasting species.

Other Heliconius butterflies mimic only one nonpalatable species. Researchers aren’t sure if other butterfly species use DNA flipping to determine their patterns. 

Found in: Genes & Cells and Life

View the original article here

Stress spears deployed service personnel

LAS VEGAS — Soldiers fighting at the tip of the spear — the leading edge of combat — confront fighting, suffering and dying. But the success of those soldiers’ operations depends on a huge network of service and support personnel who themselves face considerable and often overlooked war stress, says military sociologist Wilbur Scott of the U.S. Air Force Academy in Colorado Springs.

After returning from one or more deployments, National Guard combat service personnel — including clerks, truck drivers, medics and supply officers — displayed slightly less emotional resilience and described having experienced more stress while overseas and after returning home than their comrades engaged in combat, Scott reported August 20 at the annual meeting of the American Sociological Association.

In particular, combat service personnel cited deployment stress triggered by exposure to danger, life-threatening situations and death.

Their responses reflect the changed nature of warfare, Scott suggested. In Iraq and Afghanistan, counterinsurgency efforts have replaced conventional warfare. “While those in combat arms typically are thought of as being at the tip of the spear, this thinking applies more accurately to conventional settings rather than those encountered in Iraq and Afghanistan,” Scott said.

Combat units not only fight and kill but establish relationships with local officials, head local building projects and encourage trust in local governments. Service personnel work in the midst of operations, where they can encounter guerilla attacks or roadside bombs.

Poor coping upon returning from National Guard deployment — whether among former service personnel or combat troops — usually involved excessive alcohol drinking, abuse of prescription drugs and carrying a gun for protection, Scott said. Those behaviors are a potentially deadly mix.

Such findings underscore the need to provide programs that ease veterans back into civilian life, commented military sociologist Bradford Booth of ICF International, a private research and consulting firm in Fairfax, Va. Booth directed a pilot study of a government-funded program for 4,000 National Guard members returning home in 2007 from a year in Iraq.

In that study, those who attended three once-a-month training sessions — which focused on mental health issues, strengthening marriages, financial counseling and other topics — displayed signs of adjusting better than vets who declined to attend training.

Although traditionally regarded as “weekend warriors,” National Guard volunteers now regularly get deployed for up to one year in Iraq and Afghanistan.

Scott and his colleagues surveyed 1,460 Army National Guard soldiers, including 969 deployed solely to war zones in Afghanistan or Iraq.

Whether combat or service personnel, soldiers returning from war zones were most likely to report having grappled with and found some meaning in their military experiences. Yet they also reported the most symptoms of post-traumatic stress disorder and the worst difficulties readjusting to civilian life.

“Experiencing personal growth from going through tough times doesn’t mean you’re doing well,” Scott said.

Found in: Humans and Science & Society

View the original article here

Lager's mystery ingredient found

Galls — growths resulting from a fungal infection — grow on southern beech trees in Northern Patagonia. Scientists recently found a wild yeast that gave rise to a hybrid yeast used to brew lagers in such galls on trees growing in and near two national parks in Argentina.Diego Libkind

Lager beers got their start in Bavaria, but it was a little South American spice that really kicked things off.

Scientists have known for decades that a hybrid species of yeast, Saccharomyces pastorianus, is the microbe that ferments lagers. It’s also well known that one parent of S. pastorianus is the common baking and brewing yeast Saccharomyces cerevisiae. But the other parent of lager yeast has eluded scientists, who have scoured Europe and North America looking for it.

Turns out they were looking in the wrong hemisphere. An international team of researchers led by Chris Todd Hittinger of the University of Wisconsin–Madison and Diego Libkind of the Argentinean National Council for Scientific and Technical Research in Bariloche has tracked the missing wild parent of lager yeast to the beech forests of Patagonia. The researchers report the capture of the newly discovered yeast, dubbed Saccharomyces eubayanus, online the week of August 22 in the Proceedings of the National Academy of Sciences.

“I got chills reading [about] it, I was so excited,” says Barbara Dunn, a comparative geneticist at Stanford University who has been on the trail of the wild yeast herself. “It is incredibly surprising that it is from Patagonia.”

Libkind found S. eubayanus in galls — pale peach, balloonlike structures resulting from fungal infections — on Patagonian beech trees. The galls, full of sugar, house S. eubayanus and another wild yeast that ferment the sugars. It’s generally chilly in Patagonia, just the way lager yeast like it. Lagers are brewed at 4° to 9° Celsius (39° to 48° Fahrenheit).

The S. cerevisiae yeast used for making ales, wines and other alcoholic beverages don’t like the cold, preferring temperatures of about 15° to 25° C (59° to 77° F). So when Germans started brewing beers in the winter to avoid summertime contaminants such as molds, bacteria and other things that skunk beer, the new brewing conditions would have favored the creation of a hybrid lager yeast based on S. cerevisiae and a cold-loving relative, says Antonis Rokas, an evolutionary biologist at Vanderbilt University.

The surprise is where that partner came from. Bavarian brewers started making cold-brewed beers in the 15th century, before Columbus crossed the Atlantic (although the lagers didn’t have a big breakout in popularity until much later). S. eubayanus probably hopped a ship for Europe sometime early in the 16th century. The researchers aren’t sure exactly how S. eubayanus got to Bavaria; perhaps by hitching a ride on pieces of beech wood or barrels made of beech, or on fruit or even in the belly of a fruit fly. However it got to Europe, when S. eubayanus arrived it found a ready-made niche and a partner to merge with, Rokas speculates.

It’s also possible that S. eubayanus lives or lived in some forgotten pocket of the Old World, Hittinger says. “Obviously we haven’t searched every habitat on the entire globe.”

Knowing the identity of the wild parent may help scientists learn how the lager hybrids formed and how domestication genetically changed the yeast, Rokas says. Brewers may also be able to create new hybrid strains that can be tailored for modern brewing practices.

Found in: Genes & Cells

View the original article here

Spoilers freshen up stories

People who read the last page of a mystery novel first may be on to something. Giving away plot surprises generally makes readers like stories better, say psychology graduate student Jonathan Leavitt and psychologist Nicholas Christenfeld, both of the University of California, San Diego.

Volunteers especially enjoyed classic short stories, including mysteries and tales with ironic twists, after seeing spoiler paragraphs that revealed how the yarns ended, Leavitt and Christenfeld report in a paper published online August 12 in Psychological Science.

“Spoilers may enhance story enjoyment by making texts easier to read and understand, leading to deeper comprehension, or they may reduce readers’ anxiety about what’s to come, allowing them to focus on a story’s aesthetic details,” Leavitt says. These responses could explain why a favorite book can be read many times with undiminished pleasure, he suggests.

It’s also possible that spoilers amplify stories’ appeal by increasing tension, Leavitt adds. Giving away the ending of, say, Oedipus Rex may elicit pleasurable tension as a reader contemplates the title character marching unknowingly to his doom.

“The impact of suspense on enjoyment seems likely to be more complicated than the simple take-home point of this new article,” remarks psychologist Leigh Ann Vaughn of Ithaca College in New York. Spoilers may apply a pleasant oomph to well-told tales but could easily intensify readers’ distaste for unappealing or boring stories, Vaughn suggests.

Leavitt and Christenfeld recruited 819 college students to read short ironic-twist tales, mysteries and literary stories. For each story, the researchers created a spoiler paragraph that revealed the outcome in a seemingly inadvertent way. Data from students who had previously read these stories were excluded.

Each volunteer read one story after reading a spoiler beforehand, a second story with the spoiler incorporated as the opening paragraph and a third narrative with no spoiler.

Some spoilers in the new study revealed ironic plot twists, such as mentioning that a condemned man’s apparent escape from hanging is just a momentary fantasy, or they demystified crimes, such as divulging that an apparent target of attempted murder turned out to be the perpetrator.

Spoilers also spiced up subtler stories. One paragraph overtly disclosed that a teenage boy and girl watching a couple struggle with a baby were glimpsing their own future, while the couple relived their own past upon seeing the teens.

Overall, participants reported liking all stories best after first reading spoilers. Spoilers incorporated into the beginning of the text had no effect on story enjoyment, yielding no more pleasure than unspoiled stories.

That result may be due to peoples’ general belief that spoilers ruin stories. So giving away outcomes in a way that seems unintended — as in artfully worded prefatory paragraphs or book reviews — may be necessary to enrich reader satisfaction, Leavitt proposes.

Birthday presents wrapped in cellophane, like stories preceded by spoilers, would give recipients an unexpected thrill, he predicts. “In both cases, the outcome is known, yet there is still pleasure in unraveling the clues, or the plastic wrap, as the case may be,” Leavitt says.

Found in: Humans and Psychology

View the original article here

News in Brief: Earth & Environment

Antarctic ice flows, atmospheric response to nuclear fallout and more in this week's news Web edition : Saturday, August 20th, 2011 Moving Antarctic ice forms a tributary system across the continent in this map based on satellite radar.Science/AAAS

Icy flows

A new map of Antarctica assembled from satellite radar data reveals how ice shifted around on the frozen continent between 2007 and 2009. Ice flowing through narrow channels forms a river-like tributary system that accounts for much of the movement, a team led by Eric Rignot of the University of California, Irvine reports online August 18 in Science.  Researchers want to better understand how great ice sheets like Antarctica’s respond as global temperatures rise. —Alexandra Witze

Arctic may get breather in sea-ice losses

Roughly half of the recent loss of summertime Arctic sea ice appears to be due to greenhouse gas emissions as a result of human activity, the rest from natural climate variability, report scientists at the National Center for Atmospheric Research in Boulder, Colo. Their new analyses also indicate that even as global warming continues, summer Arctic sea ice losses could pause. “We could see a 10-year period of stable ice or even an increase,” says lead author Jennifer Kay. Her team’s analyses appeared online August 11 in Geophysical Research Letters. —Janet Raloff

Japanese fallout left electric signature

Radioactive fallout from the tsunami-crippled Fukushima reactors in Japan caused a rapid and dramatic response in the atmosphere’s electric field. The effect, brought about by a change in the atmosphere’s charge, showed up 150 kilometers southwest of the nuclear facility. Similar changes have occurred elsewhere after nuclear weapons tests and the Chernobyl accident, usually as rain washed fallout from the air. The Japanese radiation signature instead marked the arrival of fallout carried by dry low-altitude winds, scientists from Japan and Sweden reported online August 12 in Geophysical Research Letters. They conclude that early-warning electrical sensors be installed around all reactors to detect fallout. —Janet Raloff

Found in: Earth and Environment

View the original article here

Magnitude 5.8 earthquake hits Virginia

A map released by the USGS reveals the epicenter of Tuesday’s earthquake in Virginia (red star), as well as areas of "very strong" shaking with the potential for "moderate" damage (orange). Less intense shaking fades to turquoise.USGSThe seismically sleepy mid-Atlantic states were struck by a magnitude 5.8 earthquake on August 23. At 1:51 p.m. EDT on Tuesday an earthquake struck Virginia, 135 kilometers southwest of Washington, D.C. It’s among the largest temblors to strike the state in recorded history.

The quake’s epicenter was located in central Virginia about 61 kilometers northwest of Richmond, at a preliminary estimated depth of 6 kilometers. Reports of the quake were posted on the U.S. Geological Survey’s Did You Feel It? website from as far away as Ohio and New York. That’s not unusual for earthquakes on the East Coast, which are commonly felt over a wide area.

“An event of the same size is felt over a much larger area in the East, compared to the West,” says Charles Ammon, an earthquake seismologist at Pennsylvania State University in University Park.

Vibrations from an 1897 temblor centered on Virginia’s Giles County, magnitude 5.9, reached Georgia and Pennsylvania and as far westward as Kentucky and Indiana. Chimneys crumbled and visible fissures appeared during this event.

On Tuesday, buildings rattled and lights flickered as people took to the streets in the nation’s capital. Both the U.S. Capitol Building and the Pentagon were evacuated, the Associated Press reported — as was the building that houses the USGS Earthquake Hazards Program in Reston, Va. While it’s unclear if the city’s buildings suffered much structural damage from the quake, three pinnacles did snap off the central tower of the Washington National Cathedral, says Richard Weinberg, media spokesperson. Stone masons and engineers are assessing the full extent of the damage.

Earthquakes in the mid-Atlantic tend to be small — like last year’s magnitude 3.6 temblor beneath Germantown, Md. The East Coast lacks the active fault systems created by colliding continental plates characteristic of California and the West Coast. The crust that underlies the mid-Atlantic region tends to be older, cooler and more stable. The recent quake likely started on a previously unknown fault that has been dormant for a long time in the middle of the Central Virginia Seismic Zone.

The East Coast isn’t entirely immune to big ones, though. In 1886 an earthquake registering between magnitude 6.6 and 7.3 hit Charleston, S.C., damaging an estimated 2,000 buildings and killing dozens of people.

A small magnitude 2.8 aftershock gently rocked Virginia again at 2:46 p.m. Rumors, spread in some initial news reports about the event, that this latest earthquake is a foreshock coming before a larger event are just speculation.

“There’s no scientific method that could identify a foreshock,” says Ammon.

Found in: Earth and Earth Science

View the original article here

The Iceman's last meal: goat

Researchers examine the stomach contents of a famous 5,300-year-old mummyWeb edition : Monday, August 22nd, 2011 Scientists have only now discovered the stomach of the 5,300-year-old Iceman mummy, because many of the internal organs had shrunk and moved from their original positions.South Tyrol Museum of Archaeology

Outside of the Nancy Grace show, few people have had their final hours as poked, prodded and scrutinized as much as Ötzi, the “Iceman” who died high in the Italian Alps 5,300 years ago.

Hikers discovered his frozen, mummified body in 1991. Two decades later, scientists have a good idea of what happened to Ötzi: Fleeing pursuers, he retreated to the mountains only to be shot in the back with an arrow. But even today, the Iceman is still giving up surprises.

New, more detailed radiological images of the mummy have revealed his stomach for the first time and shown that he didn’t die hungry. Within an hour of his murder, Ötzi ate a big meal mostly of the wild goat called ibex, reports a team led by Albert Zink, head of the Institute for Mummies and the Iceman in Bolzano, Italy.

“We now think that he must have felt quite safe, because otherwise he wouldn’t have had this big meal,” Zink says. “This was a really big surprise.” The work was published online August 17 in the Journal of Archaeological Science.

The Iceman may have eaten meat fairly regularly, the scientists suggest; the new scans also uncovered three gallstones, a sign that his diet could have been richer in animal products than researchers thought. And newfound signs of heavy strain in Ötzi’s knees may mean he walked a lot in mountainous terrain — as opposed to being a valley dweller who wandered up high just before his death.

In life, Ötzi was a brown-eyed, long-haired man in his mid-40s who stood 5 foot 3 inches tall, average height for the Copper Age. In death, he became one of the world’s best-preserved mummies, thanks to the ice that encased him soon after his murder. When climbers found Ötzi sticking out of a retreating glacier front in September 1991, scientists rushed his body into a climate- and humidity-controlled cell so he wouldn’t thaw.

Until now, the closest researchers had gotten to Ötzi’s last meal was locating and taking samples from his colon. It contained the remains of several meals, including the meat of red deer and ibex along with vegetables and grains like einkorn, a local wheat.

But in 2005 Zink’s team took new and more detailed X-ray computed tomography images of the mummy, quickly sliding the frozen corpse in and out of a hospital scanner. Those images revealed an organ once thought to be part of the colon but now recognizable as the long-sought stomach. After death, many of the Iceman’s organs shrank and moved from their original locations, and nobody had recognized the stomach because it had shifted into the upper abdomen, Zink says.

In November, the researchers pulled some of Ötzi’s stomach contents out through an incision in the abdominal wall. Preliminary DNA analysis of the fatty tissue shows it came from an ibex.

“What we have found is that he consumed an omnivorous diet,” says Klaus Oeggl, a paleobotanist at the University of Innsbruck in Austria who is analyzing the nonmeat parts of the stomach contents. The Iceman’s last several meals contained a mix of meat, vegetables and grains, but with a lot more meat in his final meal.

To Zink, a full stomach suggests that Ötzi wasn’t actively fleeing from his pursuers just before he died. Oeggl, however, speculates that the Iceman could have gotten a head start on those chasing him, then sat down for a break before an enemy surprised and shot him from behind.

“I’ve been on top of this particular mountain, and it’s an ideal place to stop and have a rest, maybe have something to eat,” adds Frank Rühli, head of the Center for Evolutionary Medicine at the University of Zurich in Switzerland. Once the arrow hit Ötzi, Rühli and other scientists reported in 2007, it tore open an artery and sent him into fatal hemorrhagic shock. He died on the spot.

Other evidence supports the theory that the Iceman had been under stress in the days before he died. In his last 33 hours, Ötzi moved from up near the timber line to down among the trees and up again into the realm of ice, as shown by pollen grains from various alpine plant species lodged in his body.  

Ötzi also had a deep laceration on his right hand that he received at least several days before he died.

One factor that may have made the Iceman’s life uncomfortable — though it certainly didn’t kill him — was the state of his teeth. Rühli and his colleagues recently took a close look at Ötzi’s teeth and found that the Iceman had a lot of cavities. “The whole oral health of the Iceman was much worse than we had thought before,” says Rühli.

In October, Iceman scientists will gather in Bolzano for a 20th anniversary symposium to talk about what they’ve learned about the life and death of Ötzi. That will probably include the first complete analysis of the Iceman’s nuclear DNA, which has been finished but not yet formally published.

Found in: Humans

View the original article here

The world's oldest profession: chef

CHEW, CHEW, SLEEP, CHEWThis chimp and other non-human primates spend nearly half their time eating, but new research demonstrates that the cooking skills of Homo erectus allowed the lineage to save time and extract more nutrients, paving the way for bigger brains.Ronan Donovan

Nearly 2 million years ago, it seems the original naked chef was cooking up a storm. Homo erectus, the extinct hominid that’s a mere branch or so away from humans on the family tree, was the first to master cooking, new evidence suggests. This seminal event had huge implications for hominid evolution, giving the ancestors of modern humans time and energy for activities such as running, thinking deep thoughts and inventing things like the wheel and beer-can chicken.

“In the big picture, eating cooked food has huge ramifications,” says Harvard’s Chris Organ, a coauthor of the new study. Cooking and other food-processing techniques aren’t just time-savers; they provide a bigger nutritional punch than a raw diet. The new work is further evidence that cooking literally provided food for thought, making it easier for the body to extract calories from the diet that could then be used to grow a nice, big brain.

Humans are the only animals who cook, and compared to our living primate relatives we spend very little time gathering and eating food. We also have smaller jaws and teeth.

Homo erectus also had small teeth relative to others in the human lineage, and the going idea was that hominids must have figured out how to soften up their food by the time that H. erectus evolved. But behavioral traits such as the ability to whip up a puree or barbecue ribs don’t fossilize, so a real rigorous test of the H. erectus-as-chef hypothesis was lacking.

Organ and his colleagues, including Harvard’s Richard Wrangham, an early champion of the cooking hypothesis, decided to quantify the time one would expect humans to spend eating by looking at body size and feeding time in our living primate relatives. After building a family tree of primates, the researchers found that people spend a tenth as much time eating relative to their body size compared with their evolutionary cousins — a mere 4.7 percent of daily activity rather than the expected 48 percent if humans fed like other primates.

Then the team looked at tooth size within the genus Homo. From H. erectus on down to H. sapiens, teeth are much smaller than would be predicted based on what is seen in other primates, the team reports online the week of August 22 in the Proceedings of the National Academy of Sciences.

“Tooth size becomes dramatically smaller than what we would expect,” says paleoanthropologist David Strait of the University at Albany in New York, who was not involved with the work. “This is really compelling indirect evidence the human lineage became adapted to and dependent on cooking their food by the time Homo erectus evolved.”

Found in: Humans

View the original article here