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

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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

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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

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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

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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

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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

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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

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