Biology // Current TV

Ancient body clock discovered that helps to keep all living things on time

The mechanism that controls the internal 24-hour clock of all forms of life from human... more

JRBarilla
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Article: How synthetic biology will bring us cheaper plastics by ruining the poorest nations on Earth.

The Sins of Syn Bio. How synthetic biology will bring us cheaper plastics by ruining... more

frankpatton
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Ape Genius

A PBS Nova presentation on the growing cultural intelligence of the greater apes.

Vierotchka
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Do Bees do a better Democracy then us?

On bees and democracy, interesting observation.

Vierotchka
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Jumpin Jammerz ($45-60) For You

Jumpin Jammerz ($45-60) For You.We’re scratching our heads as to why these seem... more

kamoo
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Dead Birds Fall in Italy, Sweden, U.S. (AR, LA, KY) | Millions of Dead Fish Found in Brazil, New Zealand, U.S. (MD, SC) | Constant Updates | Photos | Videos

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EthicalVegan
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Panda Cow” Born in Larimer County

Panda Cow” Born in Larimer County.The miniature panda cow is the result of... more

websmeo
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Panda Cow’ Born In Nothern Colorado

Latest News Updates A rare miniature cow with markings similar to a panda bear was... more

imranweb0321
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Latest News Panda Cow’ Born In Nothern Colorado

Recently Complete Animal News Updates CAMPION, Colo. A rare miniature cow with... more

imranweb0321
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Obesity is a growing global health problem, and we all know why, don't we? It's the fault of corporations that sell corn syrup, and a starkly unequal society (why would you want to quit smoking if you're trapped below the poverty level?) Or, if you prefer a different flavor of self-righteousness, how about: a lack of personal responsibility and moral fiber (nobody made you eat all those fries, mister). Ideologues on the left and on the right like to claim they have this one covered. So what I liked about this paper is the way it plays havoc with the usual talking points. It reports that over the past 50 years, as American people became fatter, so did American chimpanzees, rats, marmosets, dogs, cats and other animals. That can't be because the chimps took office jobs and the cats got into eating out. Our public conversation about the causes of obesity is missing something.

In the paper, published last month in the Proceedings of the Royal Society B, Yann Klimentidis and his co-authors looked at animals' adult body weight over the past five decades in 24 populations of eight different species that live around people—from wild rats in Baltimore to captive chimpanzees. Every one showed an increase in average body weight over time. As Carrie Arnold reported, the average weight of lab mice in the study rose 12 percent per decade, and captive marmosets gained an average of 9 percent per decade. Chimps, for some reason, are doing especially badly, as Travis Saunders noted at Obesity Panacea: Their average body weight has risen 33 percent per decade.

What's causing this multi-species obesity epidemic? If it were humanity—if, for instance, people used to eating more themselves were giving more food to their dogs and cats and lab rats—then untamed populations shouldn't have been affected. But the researchers found that feral animals were also getting pudgier. The street rats in Baltimore showed an average weight increase of nearly 7 percent per decade. That's more than the captive rats in the study, whose average gain was 3 percent.

In any event, because lab protocols track precisely how animals are housed and fed, the Klimentidis et al. could show that the weight gain in lab animals wasn't caused by changes in their food or activities.

So what is the underlying cause? The answer, say the researchers, is to ideologues what garlic is to a vampire: We don't know. A good overview of the possibilities is here (hat tip to Saunders, who recommends this very interesting paper). David Allison of the University of Alabama, one of the Royal Society B study's authors, told Arnold he thinks the answer or answers likely will be found in industrial chemicals and viruses. It appears that the question's wide open, to (I hope) the consternation of people who want us to believe they have figured obesity out.

Their ideology is prone to close our minds. But the actual science of obesity appears likely to blow them wide open.

Klimentidis, Y., Beasley, T., Lin, H., Murati, G., Glass, G., Guyton, M., Newton, W., Jorgensen, M., Heymsfield, S., Kemnitz, J., Fairbanks, L., & Allison, D. (2010). Canaries in the coal mine: a cross-species analysis of the plurality of obesity epidemics Proceedings of the Royal Society B: Biological Sciences DOI: 10.1098/rspb.2010.1890

Keith, S., Redden, D., Katzmarzyk, P., Boggiano, M., Hanlon, E., Benca, R., Ruden, D., Pietrobelli, A., Barger, J., Fontaine, K., Wang, C., Aronne, L., Wright, S., Baskin, M., Dhurandhar, N., Lijoi, M., Grilo, C., DeLuca, M., Westfall, A., & Allison, D. (2006). Putative contributors to the secular increase in obesity: exploring the roads less traveled International Journal of Obesity, 30 (11), 1585-1594 DOI: 10.1038/sj.ijo.0803326Obesity is a growing global health problem, and we all know why, don't we?... more

UtopianSky
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Tragedy in Black and White | A Journey to the Future of Antarctica

December 10, 2010 Tragedy in Black and White By ELIZABETH ROYTE FRASER’S... more

EthicalVegan
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Don't trust what you see!

Brain’s visual circuits edit what we see before we see it.

The brain’s visual neurons continually develop predictions of what they will perceive and then correct erroneous assumptions as they take in additional external information, according to new research done at Duke University.

This new mechanism for visual cognition challenges the currently held model of sight and could change the way neuroscientists study the brain. Neurons in the brain predict and edit what we see before we see it, the researchers found.

The new vision model is called predictive coding. It is more complex and adds an extra dimension to the standard model of sight. The prevailing model has been that neurons process incoming data from the retina through a series of hierarchical layers. In this bottom-up system, the lower neurons first detect an object’s features, such as horizontal or vertical lines. The neurons send that information to the next level of brain cells that identify other specific features and feed the emerging image to the next layer of neurons, which add additional details. The image travels up the neuron ladder until it is completely formed.

But new brain imaging data from a study led by Duke researcher Tobias Egner provides “clear and direct evidence” that the standard picture of vision, called feature detection, is incomplete. The data, published Dec. 8 in the Journal of Neuroscience, show that the brain predicts what it will see and edits those predictions in a top-down mechanism, said Egner, who is an assistant professor of psychology and neuroscience.

In this system, the neurons at each level form and send context-sensitive predictions about what an image might be to the next lower neuron level. The predictions are compared with the incoming sensory data. Any mismatches, or prediction errors, between what the neurons expected to see and what they observe are sent up the neuron ladder. Each neuron layer then adjusts its perceptions of an image in order to eliminate prediction error at the next lower layer.

Finally, once all prediction error is eliminated, “the visual cortex has assigned its best guess interpretation of what an object is, and a person actually sees the object,” Egner said. He noted that this happens subconsciously in a matter of milliseconds. “You never even really know you’reface and house imagesdoing it,” he said.

Egner and his colleagues wanted to capture the process almost as it happened. The team used functional Magnetic Resonance Imaging, or fMRI, brain scans of the fusiform face area (FFA), a region that deals with recognizing faces. The researchers monitored 16 subjects’ brains as they observed faces or houses framed in different colored boxes that predicted the likelihood of the picture being a face or house.

Study participants were told to press a button when they observed an inverted image of a face or house, but the researchers were measuring something else. By changing the face-frame or house-frame color combination, the researchers controlled and measured the FFA neural response to tease apart responses to the stimulus, face expectation and error processing.

If the feature detection model were correct, the FFA neural response should be stronger for faces than houses, irrespective of the subjects’ expectations. But Egner and his colleagues found that if subjects had a high expectation of seeing a face, their neural response was nearly the same whether they were actually shown a face or a house. The study goes on to use computational modeling to show that this pattern of neural activation can only be explained by a shared contribution from face expectation and prediction error.

This study provides support for a “very different view” of how the visual system works, said Scott Murray, a University of Washington neuroscientist who was not involved in the research. Instead of high neuron firing rates providing information about the presence of a particular feature, high firing rates are instead associated with a deviation from what neurons expect to see, Murray explained. “These deviation signals presumably provide useful tags for something the visual system has to process more to understand.”

Egner said that theorists have been developing the predictive coding model for the past 30 years, but no previous studies have directly tested it against the feature detection model. “This paper is provocative and motions toward a change in the preconception of how vision works. In essence, more scientists may become more sympathetic to the new model,” he said.

Murray also said that the findings could influence the way neuroscientists continue to study the brain. Most research assumes that if a brain region has a large response to a particular visual image, and then it is somehow responsible for, or specialized for, processing the content of the image. This research “challenges that assumption,” he said, explaining that future studies have to take into account expectations that participants have for the visual images being presented.Brain’s visual circuits edit what we see before we see it. The brain’s... more

UtopianSky
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Q'Orianka Kilcher: Rights of Indigenous Peoples

Speaking at the International Forum on Globalization, Q'Orianka challenges... more

Mobius2012
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Researchers find a 'liberal gene'

Liberals may owe their political outlook partly to their genetic make-up, according to new research from the University of California, San Diego, and Harvard University. Ideology is affected not just by social factors, but also by a dopamine receptor gene called DRD4. The study's authors say this is the first research to identify a specific gene that predisposes people to certain political views.

Appearing in the latest edition of The Journal of Politics published by Cambridge University Press, the research focused on 2,000 subjects from The National Longitudinal Study of Adolescent Health. By matching genetic information with maps of the subjects' social networks, the researchers were able to show that people with a specific variant of the DRD4 gene were more likely to be liberal as adults, but only if they had an active social life in adolescence.

Dopamine is a neurotransmitter affecting brain processes that control movement, emotional response, and ability to experience pleasure and pain. Previous research has identified a connection between a variant of this gene and novelty-seeking behavior, and this behavior has previously been associated with personality traits related to political liberalism.

Lead researcher James H. Fowler of UC San Diego and his colleagues hypothesized that people with the novelty-seeking gene variant would be more interested in learning about their friends' points of view. As a consequence, people with this genetic predisposition who have a greater-than-average number of friends would be exposed to a wider variety of social norms and lifestyles, which might make them more liberal than average. They reported that "it is the crucial interaction of two factors -- the genetic predisposition and the environmental condition of having many friends in adolescence -- that is associated with being more liberal." The research team also showed that this held true independent of ethnicity, culture, sex or age.

Fowler concludes that the social and institutional environment cannot entirely explain a person's political attitudes and beliefs and that the role of genes must be taken into account. "These findings suggest that political affiliation is not based solely on the kind of social environment people experience," said Fowler, professor of political science and medical genetics at UC San Diego.

"It is our hope that more scholars will begin to explore the potential interaction of biology and environment," he said. "The way forward is to look for replication in different populations and age groups."Liberals may owe their political outlook partly to their genetic make-up, according to... more