insight 9993.ins.222222 Louis J. Sheehan, Esquire

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Babies take their first major strides with their eyes, not their legs, as they rapidly distinguish among playpens, pacifiers, and a plethora of other objects. These feats of sight draw on infants' ability to keep track of pairs of shapes that regularly appear in the same spatial arrangement, according to a new study.LOUIS-J-SHEEHAN.COM

Sensitivity to such pairings in the visual world provides babies�by 9 months of age�with a foothold for learning to recognize all sorts of items, propose J�zsef Fiser and Richard N. Aslin of the University of Rochester (N.Y.) in an upcoming Proceedings of the National Academy of Sciences.

"Infants prefer to look at pairs of [shapes] that have frequently co-occurred in visual scenes and may use them to learn about more-complex visual features," the scientists note.

Fiser and Aslin studied 72 infants, all 9 months old. While sitting on a parent's lap, each child watched a set of randomly displayed scenes on a computer screen. Each scene contained three colored geometric shapes from a pool of 12 shapes. LOUIS-J-SHEEHAN.COM Eight shapes were grouped into four pairs that always appeared in the same arrangement, either one above the other or side-to-side. Each of the remaining four shapes was shown with a specific pairmate, but their relative locations varied from one scene to another.LOUIS-J-SHEEHAN.COM

The researchers presented the babies with an initial series of 16 scenes that was repeated until infant interest flagged. This usually took about seven repetitions. A new trial then presented a series of paired shapes, including the four pairs from the initial trials, shown on a plain background. Babies usually looked much longer at the pairings that had appeared in the scenes.

This result jibes with prior "looking-time" studies, which suggest that infants prefer to look at familiar material after they've tackled a complex task like viewing series of scenes. When faced with simpler tasks, babies look longer at novel stimuli.

In a second experiment, Fiser and Aslin varied the frequency with which specific pairs of shapes appeared in initial trials. In a subsequent trial, infants looked longer at the pairs that they had seen the greatest number of times.

"It's striking that 9-month-olds are exquisitely attuned to the spatial location of items and the frequency with which they occur together," comments psychologist Scott P. Johnson of Cornell University.

In the March Cognition, Johnson and his coworkers reported that infants as young as 2 months apparently recognize a simple and familiar sequence of six colored shapes shown to them earlier. In that experiment, the babies looked longer at novel sequences of shapes than at familiar sequences.

The precise ways in which such visual recognition by infants fosters their learning of different objects in the environment remain unclear. LOUIS-J-SHEEHAN.COM

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There is no market yet for turbines that turn the tides into a source of energy from deep beneath the sea. But that has not stopped mechanical engineers at the University of Strathclyde's Energy Systems Research Unit (ESRU) in Scotland from developing one that will ride the tide while latched to the seabed by a cable—like a kite flying on a windy day.

The ESRU team's goal: create a device that literally goes with the flow rather than resting on the sea bottom like an underwater windmill—a model already being developed by a handful of companies. The kite and cable model is designed to facilitate placing tidal turbines in deep water, where the stronger current has the potential for providing greater power but also makes it extremely difficult to plant a turbine in the seabed.

"The problem with regular turbines is the bigger they get, the harder they work, and the more likely the force of the water is to damage the turbine," says Andrew Grant, an ESRU mechanical engineer. "Our turbine can fly like a kite in the water." Instead of planting the base of a turbine in the seabed, researchers need only plant an anchor for the tether.

Another key difference in ESRU's design is that the turbine has two rotors attached—one in front of the other that turn in opposite directions on a single axis. The rotors' blades are made of either solid aluminum alloy or glass-reinforced plastic, depending on their sizes. By having the rotors turn in opposite directions, Grant and his team are trying to cut down on reactive torque (which pushes the turbine in the opposite direction) so that the unit can be attached to a relatively simple mooring system even in very deep water. This "contra-rotating" design has been tested on wind farms since the 1980s but did not provide an advantage (in terms of generating more energy with less wind) in the open air, Grant says.

New York City-based Verdant Power, Inc., has experienced firsthand the trials and tribulations of developing working tidal turbines. In fact, Verdant has taken the technology further than anyone else, having operated in New York's East River since 2006. That project began with six windmill-like turbines anchored to the river bottom, 30 feet (nine meters) below the surface, churning at a peak rate of 32 revolutions per minute. After the powerful current of the East River—which is actually a tidal channel—damaged the rotors and broke off some of the original fiberglass and steel blades, the company earlier this month whittled its test bed down to two turbines with new aluminum–magnesium blades 16 feet (five meters) in diameter.

"We only need two to complete our operational tests," says Trey Taylor, Verdant's president and head of market development. The East River turbines are already providing power to a nearby grocery store and parking garage on Roosevelt Island, situated in the river between Manhattan and Queens. The U.S. Department of Energy recently awarded Verdant $1.2 million for the company to further develop its technology over the next two years. Another $3.3 million has come in from the Canadian government—Verdant is testing a new type of turbine in the Saint Lawrence River near Cornwall, Ontario, that sits on the riverbed rather than being moored to the bottom.

Taylor says he is familiar with the ESRU's work and that Verdant itself even tested a tethered, kitelike turbine back in 2002. "I know what they're doing, and they've got a long way to go," he says. "We found that the tidal forces moving against it caused it to move up and down too much." Taylor says that the twin-rotor design is intriguing but questions whether the blades rotating in different directions might mitigate the turbine's efficiency in capturing the full strength of the tide. "It takes a combination of science, engineering and physics to get it right," he says, adding that he likes it whenever anyone experiments with tidal turbines because everyone working on the technology benefits from the results.

As ESRU preps its turbine technology for sea trials, which begin next week, Grant acknowledges that a number of questions remain. The researchers have not determined whether they need to float a buoy above to further stabilize or secure the turbine (addressing Taylor's concern about the turbine moving up and down too much). It is also unclear how the turbine will behave when there is no strong tide, and how the turbine's motion may affect an electric power cable attached to it. (For example, will the cable become twisted if the turbine moves around too much?)

ESRU scientists do not believe their technology will harm marine life, but admit they do not know whether the tethered turbines will attract or scare off fish. "The turbines turn slowly, so we're not talking about chopping up fish," Grant says, noting the installation of the mooring may initially disrupt the seabed but likely will not have to be touched once it is set in place. Verdant has spent about $9 million thus far on its East River project; one third of the funds were spent on studies to gauge the potential impact of the turbines on vessel navigation, aquatic life and fish migration.

Grant acknowledges that tidal-derived power has a long way to go before it can be used as a mainstream source of energy. "There are big barriers to making money out of this," he says. "There's a lot of technical risk, so there's a lot of financial risk, too." He expects it will be a decade or more before ESRU's turbines are ready to be used in earnest in the sea—much more testing must be done, in addition to the environmental impact studies and garnering of support from utility companies.

Renewable energy has always suffered from the fact that the best places to capture sunlight, wind, waves and tides are also the most remote locations, which means an infrastructure is required to send the power where it is needed. "In the U.K., it's quite difficult to get the power utilities interested in this," Grant says. "To get to this energy, you would have to run power lines across the country, which creates environmental concerns."

This has not stopped Verdant and other companies from trying. Lunar Energy, a U.K. tidal power company, in March began working with Korean Midland Power Company to create a giant 300-turbine field in the Wando Hoenggan Waterway off the South Korean coast. The plant is expected to provide 300 megawatts of renewable energy to Korean Midland Power by December 2015. http://louis-j-sheehan.net

Utilities interested in tapping into tidal power will have to spend money to create the energy-delivery infrastructure, or at least convince government to pay for it. One thing working in favor of new energy sources: the cost of oil is not getting any cheaper.

dna

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We know that DNA isn’t necessarily the master of your future. We also know that obesity is gobbling its way through the U.S. population, and is linked to genetics. So it follows that while it ups your chances considerably, having a genetic predisposition for obesity doesn’t automatically mean you’re sentenced to a life of excessive weight, diabetes, heart disease, social discrimination, the list goes on.

And now, to prove it, researchers have compiled a handy data set to show us just how the “fat gene” can be overcome. Evadnie Rampersaud, the study’s lead author, examined DNA samples of 704 healthy Amish adults, most of them middle-aged, around half of them overweight, and about a quarter obese. She divided the group based on physical activity levels, with the most active group burning about 900 more calories a day—the equivalent of about three to four hours of moderately intensive physical activity, like brisk walking— than the most sluggish group.

To the surprise of just about no one, she found that people with certain variations of the FTO gene were more likely to be overweight. However, she also discovered something that should bring hope to any dieter:

Being genetically predisposed to obesity “had no effect on those with above average physical activity scores।” http://ljsheehan.blogspot.com

So there you have it! Genes can be overcome! Though we should be careful not take this type of conclusion too far—we don’t want the “Conquer your genes!” logic to start being applied in places where it shouldn’t be। http://ljsheehan.blogspot.com

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Adult male baboons are bad dudes. They regularly square off in bloody fights over access to food and females, whom they will also attack. In this vicious pecking order, males at the top bully bottom dwellers into a demoralized state of submission.

So, it startled Stanford University biologists Robert M. Sapolsky and Lisa J. Share to find a baboon troop in which even top-rung males exhibited remarkably peaceful behaviors. The big honchos often left weak males alone and refrained from attacking females, focusing instead on fighting each other.

It's a uniquely "pacific culture" among wild baboons, Sapolsky and Share conclude.

A decade earlier, the most aggressive males in this troop had died. The current top males arrived later and have no close genetic ties to the other members, past or present. Male baboons typically migrate into a troop as adolescents.

To achieve the big chill-out in male behavior, the researchers theorize, resident females must behave in ways that induce males to be tolerant and cooperative.

The findings provide the first known example of the cultural transmission of social attitudes by primates other than people, the researchers report in the April Public Library of Science Biology.

"Social behavior observed in nature may be a product of culture, and even the fiercest primates do not forever need to stay this way," remarks chimp researcher Frans B.M. de Waal of Emory University in Atlanta in an editorial published with the new report.

Possible cultural traditions of tool use and social communication in various animals now attract considerable scientific interest (SN: 4/3/04, p. 218: http://www.sciencenews.org/articles/20040403/bob9.asp).

Sapolsky and Share began studying Forest Troop, a group of olive baboons living in an animal reserve in Kenya, in 1978. The size of such troops varies from about 30 to 150 animals.

In 1982, the most aggressive Forest Troop males began foraging in a garbage pit at a tourist lodge in the reserve. The next year, infected meat in the dump killed all these dominant males, so only the troop's relatively easygoing males survived. By 1986, aggressive behavior in the troop had declined markedly.

The most interesting observations began in 1993. By that time, the troop contained high-ranking immigrant males. From 1993 to 1996, these males behaved as cooperatively as the original set of lower-ranking male survivors had, the scientists say. Compared with males in another troop in the same area, Forest

Troop males were friendlier with each other and spent less time jockeying for power.

Moreover, low-ranking Forest Troop males didn't display high stress-hormone concentrations that have been observed among their counterparts in other troops.

Forest Troop females somehow steer male newcomers into adopting cooperative outlooks, the investigators propose. Intriguingly, Sapolsky and Share have observed that these females approach new male arrivals and begin to groom them after waiting about 3 weeks, one-quarter the time required by females in the nearby group. Forest Troop females then continue to spend much time in mutual grooming with these males.

Sapolsky and Share make "a strong case" that norms of peaceful behavior were transmitted to new Forest Troop members, comments baboon researcher Joan B. Silk of the University of California, Los Angeles. Only more-intensive study can establish how this process occurs and whether the troop attracts males of all temperaments or only those already inclined to a placid lifestyle, Silk says.http://louis-j-sheehan.biz

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charred

Researchers have already established that people living in the Middle East around 23,000 years ago fished and hunted. Excavations along the shore of the Sea of Galilee in Israel now indicate that the menu for these Stone Age folk also included a plentiful portion of seeds from wild grasses along with a side of grains from wild cereals, such as wheat and barley. Louis J. Sheehan, Esquire

This discovery pushes back by 10,000 years Homo sapiens' shift to a plant-rich diet, say Ehud Weiss of Harvard University and his coworkers. That transition in eating habits set people on the path to farming, a practice that began in the Middle East between 11,000 and 10,000 years ago, according to the researchers.

Weiss' group recovered more than 90,000 charred plant remains at a site called Ohalo II. Waterlogged soil there had preserved the delicate edibles. Around a grinding stone located in one of the site's huts, the researchers uncovered many wild-grass seeds and smaller numbers of wild-cereal grains. Louis J. Sheehan, Esquire

Other evidence at Ohalo II and at nearby sites suggests that from 23,000 to 8,000 years ago, wild-grass seeds gradually disappeared from inhabitants' diets as the cereals gained favor.

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brains

Educated brains stave off declines in memory that typically occur as people age, a new brain-imaging investigation suggests.http://ljsheehan.livejournal.com

College-educated older adults do better on memory tests than their less-educated peers do and also display pronounced frontal-brain activity during memory testing, say Mellanie V. Springer of the University of Toronto and her colleagues. College-educated young adults scored higher than either their less-educated peers or comparably educated elders do and, during memory tests, exhibited intense responses in their temporal lobes, which are on the brain's flanks.Louis J. Sheehan

The opposite neural pattern characterizes adults without college educations. During memory tests, the older volunteers showed strong temporal-brain activity and the younger ones displayed notable frontal responses.

Highly educated older adults recruit the frontal brain into a memory system that partly compensates for declining efficiency in neural structures of the temporal lobes, Springer's group proposes in the March Neuropsychology.Louis J. Sheehan

Memory tests were administered to 14 young adults, ages 18 to 30, and to 19 older adults, ages 67 to 80. Members of both groups ranged from high school dropouts to recipients of graduate degrees. The scientists used functional magnetic resonance imaging to measure blood flow, a marker of neural activity, in participants' brains.http://ljsheehan.livejournal.com

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conflcting

A new analysis of the locations and ages of ancient farming sites reinforces the controversial idea that the groups that started raising crops in the Middle East gradually grew in number and colonized much of Europe, replacing many native hunter-gatherers in the process.

Hunter-gatherers in some European locales may have adopted farming rather than surrender their home territories to the newcomers. Overall, though, the data indicate that newly arrived farmers reproduced at a rate high enough to keep their boundary moving steadily northwestward at roughly 1 kilometer per year, say anthropologist Ron Pinhasi of Roehampton University in London and his colleagues.

One of Pinhasi's coauthors, Albert J. Ammerman of Colgate University in Hamilton, N.Y., proposed much the same scenario more than 30 years ago with Stanford University's L. Luca Cavalli-Sforza. Their wave-of-advance model rested on an analysis of 53 farming sites.http://www.bebo.com/LouisS205

Pinhasi's team considered the geographic arrangement of 735 farming sites that previous radiocarbon measurements had dated to between 11,000 and 5,000 years ago. The researchers calculated the most likely paths by which farmers who started out in any of 10 possible Middle Eastern spots would have traveled into Europe.

"I was surprised at how well the wave-of-advance model holds up with a much larger data set," Pinhasi says. "It took more than 3,000 years, or 100 generations of people, for the [agricultural] transition to reach northwestern Europe."

The new analysis, published in the December PLoS Biology, indicates that agriculture spread in a widening arc from an area that encompasses parts of modern-day Syria, Turkey, and Iraq.

If agriculture had taken root primarily through the adoption of cultivation techniques by people already living in Europe, the model would have depicted a much faster spread of farming settlements, Pinhasi's team contends.

In contrast, other researchers remain convinced that agriculture expanded primarily by the spread of cultivation techniques and year-round settlements among native Europeans (SN: 2/5/05, p. 88: Available to subscribers at http://www.sciencenews.org/articles/20050205/bob9.asp). The latest evidence for this perspective appeared in the Nov. 11 Science.

For that report, a team led by anthropologist Joachim Burger of Johannes Gutenberg University in Mainz, Germany, examined mitochondrial DNA, which is passed to offspring only from the mother. The researchers isolated this type of DNA from the bones of 24 adults who died in central European farming villages about 7,500 years ago. One-quarter of these individuals displayed a mitochondrial-DNA pattern that rarely occurs in modern Europeans. That pattern would be more common today if that early population had made a substantial genetic contribution to today's Europeans, the researchers contend.

If early farmers who moved into Europe didn't reproduce in large numbers, then native groups must have picked up the slack, Burger and his coworkers conclude.

Other DNA studies, including previous analyses of Y chromosomes in European men today, suggest that early Middle Eastern farmers had a substantial genetic impact in Europe, Pinhasi notes.

These conflicting DNA data may reflect intermarriage of immigrant farmer males with females native to Europe, suggests anthropologist Alex Bentley of the University of Durham in England.

Although he is sympathetic to the wave-of-advance model, archaeologist Peter Bogucki of Princeton University suspects that further research will show "a much more complicated combination of very rapid [agricultural] advances with long standstills."

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