Archive for March, 2011

Study Finds Sleepwalkers Learn as They Go Through the Motions

By Valerie Ross | March 27, 2011 4:34 pm

What’s the News: By videotaping sleepwalkers as they got some shut-eye (with their permission, of course), French and Swiss researchers caught on tape what other studies have deduced through brain recordings and memory tasks: As we sleep, our brains seem to replay what we learned during the day. See an example of a a sleepwalker’s re-enactments here:

How the Heck:

  • The researchers recruited 19 sleepwalkers and 20 people with sleep behavior disorder, who physically act out their dreams, plus 18 people without any sleep disorders.
  • All the subjects learned a physical skill: hitting particular buttons arrayed around them in response to different prompts from a computer.
  • The researchers then videotaped each person as they slept. One of the sleepwalkers lifted her arms during REM sleep and started moving her hands in a familiar pattern: an “obvious and accurate re-enactment of a short fragment of the recently learned sequence of movements,” the researchers wrote.

What’s the Context:

  • whole lot of research has suggested that a good night’s sleep can improve memory not just for physical tasks like this one, but for words, facts, pictures, and spatial information.
  • Most of these studies have compared how sleep-deprived and well-rested people performed on memory tests, or looked at how closely brain activity during sleep resembled brain activity as people learned something new.  Watching people who act out their thoughts as they sleep provides a more direct view of what the brain’s up to.

Not So Fast:

  • Some scientists think that sleep’s impact on memory isn’t as simple as locking down everything we’ve learned. Sleep may only solidify memories when we know we’ll be tested, or may actually help us prune unimportant memories rather than fortify the important ones.
  • Others aren’t convinced that sleep helps us solidify memories at all; they argue that, at best, we can cement what we’ve learned while sleeping just as well as we can while we’re awake.

Reference: “Evidence for the Re-Enactment of a Recently Learned Behavior during Sleepwalking” Delphine Oudiette et al. doi:10.1371/journal.pone.0018056

Image: WikimediaCommons / Chad Fitz

CATEGORIZED UNDER: Mind & Brain
MORE ABOUT: dreams, sleep, sleepwalking

New Archeology Find Buries Theory on First Americans, Re-Opening a Gaping Mystery

By Patrick Morgan | March 25, 2011 5:06 pm

What’s the News: Archeologists have discovered thousands of stone tools in Texas that are over 15,000 years old. The find is important because it is over 2,000 years older than the so-called Clovis culture, which had previously thought to be the first human culture in North America. As Texas A&M University anthropologist Michael Waters says, “This is almost like a baseball bat to the side of the head of the archaeological community to wake up and say, ‘hey, there are pre-Clovis people here, that we have to stop quibbling and we need to develop a new model for peopling of the Americas’.”

How the Heck:

  • At a site on Buttermilk Creek in central Texas, Archeologists discovered 15,528 items, ranging from chert flakes to blades and chisels.
  • The first indication that the tools were older than anything previous seen on North America came from their stratigraphic horizon: The excavated layer was underneath a layer of classic Clovis tools. (The sediments showed no indication of mixing after the tools were dropped.)
  • The most conclusive evidence came from a dating technique called optically stimulated luminescence (OSL) dating, which indicates how long minerals have been underground. Over 60 OSL dates revealed the tools to be about 15,500 years old, much older than the up-to-13,500-year-old Clovis culture.

What’s the Context:

Not So Fast:

  • Some anthropologists say that the “Clovis first” theory went out of style years ago, and that this study only puts the nail in the Clovis coffin.
  • Others are skeptical about this present finding, noting that OSL dating is less reliable than radiocarbon dating and that the site’s deposits are “potentially problematic” because they’re located on an old floodplain and could have been transported by water.

The Future Holds: Now it’s time for archeologists to rethink the North American narrative of migration: How did humans first populate the continent? As James Adovasio, the executive director of the Mercyhurst Archaeological Institute, told NPR, “Everything we’re learning now, from genetics, from linguistic data, from geological data, from archaeological data, suggests that the peopling process is infinitely more complicated than we might have imagined 50 years ago, or even 20 years ago.”

Reference: The Buttermilk Creek Complex and the Origins of Clovis at the Debra L. Friedkin Site, Texas. By Michael R. Waters et al. DOI: 10.1126/science.331.6024.1512

Image: Courtesy of Michael R. Waters

CATEGORIZED UNDER: Human Origins

To Boldly Grow Where No Sperm Has Grown Before: in a Petri Dish

By Patrick Morgan | March 25, 2011 1:09 pm

What’s the News: For the first time in medical history, scientists have successfully grown mouse sperm in a laboratory. As Northwestern University cell biologist Erwin Goldberg told New Scientist, “People have been trying to do this for years.” It’s hoped that being able to grow sperm outside the testes will lead to improved fertility treatments for men.

How the Heck:

  • The concept is simple: Combine the right dosage of chemicals that will provide nourishment to testes in a petri dish. Actually finding the magic amount is a tedious process of trial and error.
  • First, the team genetically engineered mice “so that a protein only present in fully grown sperm would fluoresce green.”
  • Next, the scientists extracted germ cells (which produce sperm) from the newborn mice testes, and put them in a bath of agarose gel, fetal bovine serum, testosterone, and other chemicals.
  • After about a month, they discovered that virtually half of the lab-grown sperm were glowing, indicating that they were fully grown.
  • They then used in vitro fertilization to impregnate female mice, who eventually gave birth to fertile mice themselves.

Context:

Not So Fast:

  • The researchers developed offspring using only 100 sperm cells; doctors would like to see “millions if possible” to make successful fertility treatments in humans.
  • Scientists may have observed “healthy and reproductively competent offspring,” but they don’t delve into the possible long-term side effects of creating people from sperm developed off the traditional route. In vitro sperm creation could be compared to IVF, a technique that leads to greater risk of diabetes and some other conditions. Researchers still aren’t sure why this is, though they have made some headway, discovering that the DNA of IVF-babies actually differs from other children.

Next Up: This technique still needs to be proved in humans, and if it is, it could have wide-ranging effects. For example, in the future, doctors might be able to extract testicular tissue from young boys—who haven’t yet developed mature sperm—and then grow sperm in the lab. Or for infertile men, doctors could extract germ cells, produce sperm, and then find out what’s wrong with them.

Reference: “In vitro production of functional sperm in cultured neonatal mouse testes” Takuya Sato et al. doi:10.1038/nature09850

Image: Wikimedia Commons / Bobjgalindo

CATEGORIZED UNDER: Health & Medicine, Living World

The Little-Known 2007 Energy Law That May Have a Big Effect on Oil Consumption

By Patrick Morgan | March 25, 2011 10:46 am

What’s the News: In a much-ignored speech last week (not ignored by Grist), Sen. Jeff Bingaman (D-N.M.) argued that the U.S. could become less vulnerable to spiking oil prices if we used less of it (surprise!). The crux of the talk was a graph he showed of our country’s estimated petroleum imports, and specifically, the significant change inprojection between 2008 and 2011 (blue and red lines above). Our now-declining gas and oil imports are in part a result of the Energy Independence and Security Act of 2007.

How the Heck:

  • Our petroleum imports are projected to decline because the Energy Act included strategic changes to biofuel and fuel efficiency policies. For example, automakers are required to increase fleetwide gas mileage to 35 miles per gallon by 2020 and more money is being funneled into biofuel production.
  • As Bingaman said in his speech, the act will save the U.S. billions of oil barrels—more than the 23 billion that we now have in U.S. proven oil reserves.
  • The bottom line is that by including more biofuels into our gasoline and supporting alternative energies, we’ll require less petroleum and thereby rely less on the petrostates. The concept is simple, but it carries a wallop once you actually see the graph.

What’s the Context:

Not So Fast: Some green-tech writers think the EIA’s predictions are more fiction than fact. According to Chris Nelder at Green Chip Stocks, the EIA’s predictions often “present a picture of the future that looks like a continuation of the best parts of the past, with none of the bad parts.” The assumption that our oil imports will keep on declining hinges partly on technologies that haven’t been invented yet and the hope that all the policies included in the Energy Act come to fruition. The only thing you can’t argue against is that petroleum demands right now are much lower than we had expected, thanks in due part to the Energy Act. What’s more, the economy has largely sputtered since 2008, which tends to tamp down demand for energy. The graph might be more valuable if it showed oil consumption per unit of economic activity.

Image: EIA

CATEGORIZED UNDER: Environment

Scientists Use Bird-O-Vision to Learn Why Some Cuckoos Are Expert Counterfeiters

By Patrick Morgan | March 24, 2011 2:47 pm

What’s the News: The reproductive life of a cuckoo is both easy—it lays its eggs in others birds’ nests, and lets them feed the young—and difficult: cuckoos are involved in an “evolutionary arms race” with other birds, finds a new study. Even as cuckoos improve their counterfeiting skills—producing eggs that look more like others birds’—the host birds get better and better at identifying the forged eggs.

How the Heck:

  • Knowing that birds have four types of color-sensitive cone cells in their eyes, allowing them to see ultraviolet wavelengths, researchers used a spectroscope to measure the amount of light reflected from hundreds of cuckoo and host-bird eggs. They then fed this data into models to produce images showing how birds see the different types of eggs.
  • They discovered that while cuckoo and redstart eggs have a high degree of color overlap, cuckoo eggs targeted for dunnock nests did not.
  • Here’s the kicker: Redstarts and dunnocks don’t spot forgeries equally. Redstarts are more discerning of foreign eggs and readily kick out cuckoo forgeries, while the dumb dunnocks accept even the most mismatched eggs. So these findings suggest that cuckoos targeting redstarts evolved the ability to create better forgeries because the redstart has such a good eye. With dunnocks, that evolutionary force wasn’t at play because the birds are so accepting of forgeries; why bother?

What’s the Context:

The Future Holds: Scientists still aren’t sure why some hosts, like the dunnock, are so accepting of cuckoo eggs. Some scientists argue that this is because the risk in mistakenly rejecting a real egg outweighs the cost of raising a cuckoo egg. The jury’s still out.

Reference: “AVIAN VISION AND THE EVOLUTION OF EGG COLOR MIMICRY IN THE COMMON CUCKOO” Mary Caswell Stoddard and Martin Stevens. DOI: 10.1111/j.1558-5646.2011.01262.x

Image: NHM

CATEGORIZED UNDER: Living World

Nerve Cells Reach Out and Touch Someone: Electronic Components

By Patrick Morgan | March 24, 2011 10:44 am

What’s the News: Scientists have discovered a new technique for linking semiconducting tubes with mouse nerve cell tendrils: They let the cells do the work for them. After creating biologically friendly semiconductor tubes, they found that nerve cells’ tendril-like axons didn’t shy away. “They seem to like the tubes,” University of Wisconsin-Madison biomedical engineer Justin Williams told Science News. This represents a step toward new technology involving computer-brain networks.

How the Heck: The trick was to create tubes of layered germanium and silicone (which insulate the nerve’s electrical signals) that were big enough for the nerve cell’s threadlike projections to enter but too small for the cell body: When seeded with live mouse nerve cells, the only way the cells could interact with the tubes was be sending tendrils into it—which is just what they did.

What’s the Context:

Not So Fast: The researchers don’t yet know whether the connected nerves are actually talking with each other.

Next Up: Now they want to hook the tubes to voltage sensors that can “listen” to the cells communicating with each other. If successful, this could lead to new drug tests where doctors can actually measure how nerve cells respond to certain types of drugs, leading to further innovations in the battle against neurological diseases like Parkinson’s.

Image: Minrui Yu, University of Wisconsin–Madison

Reference: “Semiconductor Nanomembrane Tubes: Three-Dimensional Confinement for Controlled Neurite Outgrowth”  Minrui Yu et al. DOI: 10.1021/nn103618d

CATEGORIZED UNDER: Technology

Amazon Opens App Store for Android; Apple Is Displeased

By Patrick Morgan | March 23, 2011 10:48 pm

What’s the News: Despite Apple’s recent lawsuit against Amazon’s use of the term “Appstore,” Amazon successfully began selling applications for the Google Android smart phone yesterday. The launch unveiled two previously unmentioned perks: a free-app-of-the-day promotion and a feature called Test Drive that allows users to try apps on Amazon’s website before buying them.

What’s the Context:

  • Amazon’s Appstore, which provides over 3,800 Android apps and is in direct competition with Google’s own “Android Market,” drew the ire of Apple last week because of ownership issues over the name’s similarity to Apple’s own “App Store.” The company says Amazon’s use of the name will “confuse and mislead customers.”
  • Another way Amazon is luring people to the new store is by providing a different premium app for free each day. The first free app was Angry Birds Rio.
  • As Discoblog has covered, apps have a way of creating controversy, from Apple’s rejection of an application by a Pulitzer Prize winning cartoonist to a fair number of somewhat raunchy apps.
  • And weird apps are always game for Discoblog too, including iPhone translators that speak for you and the app that (may) clear your acne.

Not So Fast: As some tech gurus note, Amazon’s app-purchasing process is confusing for some people, and involves bypassing the Android Market and allowing “third-party apps to be installed from outside sources.” Confusion aside, this process could make you vulnerable to viruses as well.

The Future Holds: Amazon says it will soon integrate its apps into its recommendation engine, allowing you to see apps that may be relevant to you just like you can see suggested books. There’s still no official news as to whether Amazon’s Kindle will eventually be able to run the Android operation system.

Image: Amazon

CATEGORIZED UNDER: Technology

Grounded Ship Leaking Oil—& Potentially Rats—Threatens Endangered Penguins

By Patrick Morgan | March 23, 2011 1:27 pm

What’s the News: After running aground last week on a remote island off the coast of South Africa, a freighter has leaked over 800 tons of fuel oil, coating an estimated 20,000 already-endangered penguins. “The scene at Nightingale [Island] is dreadful as there is an oil slick around the entire island,” said Tristan Conservation Officer Trevor Glass said in a statement. But even worse, authorities fear that the rats from the soybean-toting ship will swim to the island and destroy the bird population.

What’s the Context:

  • The MS Oliva was traveling from Brazil to Singapore when it ran aground last Wednesday for unknown reasons, breaking up on Saturday and pouring some of its 1,500 tons of heavy oil into the surrounding waters.
  • There are over 200,000 Northern Rockhopper Penguins (nearly half the world’s population of this species) on the Tristan Da Cunha archipelago, which includes Nightingale Island. This cleanup job is especially difficult because these islands lie 1,700 miles from the closest land, South Africa, making it much more difficult to launch a significant response—not good for birds who’re already listed on the international endangered list.
  • The biggest danger to the penguins would be if if any rats make it from the ship to the island, as they can feast on baby birds unhindered. Like the birds from William Stolzenburg’s Rat Island—a gripping account of the challenges in ridding rats from infested islands—these remote birds “evolved in a world devoid of land-bound mammals,” and so are pretty much defenseless against rats.
  • 80beats has covered oil spills in the past, including last year’s BP spill and its effects on wildlife.
  • In that spill, the pelican was the oil-covered bird species that symbolized environmental disaster.

The Future Holds: Though a salvage tug left Cape Town, South Africa, last Thursday, the earliest it will arrive to help remove fuel is this Wednesday. With little to salvage, authorities say that cleanup is now the main task at hand. As Jay Holcomb, the director emeritus of the International Bird Rescue Research Center, told the New York Times, “Many of the birds have been oiled for over a week, which limits their chances of survival.”

Image: Wikimedia Commons / Arjan Haverkamp

CATEGORIZED UNDER: Environment, Living World

Study Finds Religion May Be Going “Extinct” in Some Countries

By Patrick Morgan | March 22, 2011 5:33 pm

What’s the News: Looking at census data from nine countries, a team of scientists have made the bold assertion that religion is headed for extinction and it’s all based on a mathematical model of the complex social motives behind joining religious groups. As they note in their abstract, “People claiming no religious affiliation constitute the fastest growing ‘religious’ minority in many countries throughout the world.”

How the Heck:

  • The theory behind their model “posits that social groups that have more members are going to be more attractive to join, and … that social groups have a social status or utility,” Richard Wiener from the University of Arizona told the BBC. You could call it the Facebook effect.
  • So they looked at census data spanning the past century from Australia, Austria, Canada, the Czech Republic, Finland, Ireland, the Netherlands, New Zealand and Switzerland, and discovered that an increasing number of people identify themselves as “non-affiliated” with religion. For example, 40% of the Netherlands and 60% of the Czech Republic is unaffiliated.
  • Using a nonlinear dynamics model, which allows researchers to track outcomes from a number of factors, the scientists accounted for the “social and utilitarian merits” of being in a non-religious category, concluding that religion will die in societies wherever non-religious affiliation is more socially useful than religious affiliation—which seems to be the trend in the nine countries studied.

What’s the Context:

Not So Fast: The model’s limitations are many, including its simplistic network structure, as Weiner told the BBC: It assumes that each person is equally influenced by every other person. It also assumes that mere social utility is the driving reason behind people’s religious affiliations, ignoring a slew of other, difficult to measure, non-social factors underlying faith, such as the strength of deeply personal religious convictions and a (potential) basic human tendency to believe in something larger than ourselves. The study is based on the premise that religious networks behave the same was as do speakers of a common language and non-religious social groups, a reasonable but debatable assumption.

Reference: “A mathematical model of social group competition with application to the growth of religious non-affiliation.” Authors: Daniel M. Abrams, Haley A. Yaple, Richard J. Wiener. arXiv:1012.1375

Image: flickr / DominusVobiscum

CATEGORIZED UNDER: Human Origins, Mind & Brain

The Best (Cambridge, London) and Worst (Moscow, Taipei) Cities for Science

By Patrick Morgan | March 22, 2011 1:59 pm

What’s the News: Many evaluations of scientific excellence singling out specific universities or departments, but two European researchers have taken a different approach: They rated the top scientific cities by looking at what proportion of published science articles are highly cited. Cambridge, Massachusetts, came out as the winner in physics and chemistry (no surprise there—MIT and Harvard) for having lots of influential papers; London was tops in psychology; Moscow was the chemistry and physics loser; and Taipei, Taiwan was the low achiever in psychology.



How the Heck:

  • Researchers used a science database called Web of Science to count the number of total papers and influential papers produced in cities around the world in 2008. (In chemistry, for example, a total of 10,460 papers were published that year.)
  • The expectation was that 10% of each city’s papers would appear in the top 10% of the most-cited papers. Researchers tallied up the number of actually influential papers from each city and compared that with the expected figure.
  • The under-performing cities are plotted on Google Maps as red dots, while the over-performing are green. For example, on the chemistry-cities map, Moscow’s circle is the largest because it’s publishing the most chemistry papers, but it’s red because only 5 of its papers were in the top 10% of most-cited chemistry papers, far below the expected figure of 47.7 (10% of its output).

What’s the Context:

  • The northernmost city with more than expected highly cited papers was Tromso, Norway, proving that science can prosper even in the icy, inhospitable stretches of the Norwegian Sea.
  • While fewer in number than North America, Europe, and China, there is still some thriving science cities in countries in the Middle East, including Oman and Iran—though Iraq is noticeably blank.
  • Compared to the maps of physics and chemistry, there are far more successful psychology cities.

Not So Fast: As the researchers note, the study fuzzes over any distinctions that emerge on a smaller scale than a city—for instance, the maps don’t show any difference between a city with one superstar who publishes 10 influential papers and another city with a group of 10 researchers who each publish 1. And since the scoring is based on citations, it’s subject to biases based on renown, language, and resources; the same paper published by a famous researcher at Oxford will get more notice than if it were published in Nigeria.

Reference: arxiv.org/abs/1103.3216: Lutz Bornmann and Loet Leydesdorff, Which Cities Produce Worldwide More Excellent Papers Than Can Be Expected? A New Mapping Approach—Using Google Maps—Based On Statistical Significance Testing

CATEGORIZED UNDER: Technology, Top Posts
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