Tag Archives: Biology

Strategic or random? How the brain chooses


Howard Hughes Medical Institute – The brain excels at integrating information from past experiences to guide decision-making in new situations. But in certain circumstances, random behavior may be preferable. An animal might have the best chance of avoiding a predator if it moves unpredictably, for example.

When faced with a weak competitor, the animals made strategic choices based on the outcomes of previous trials. But when a sophisticated competitor made strong predictions, the rats ignored past experience and made random selections in search of a reward. more> http://tinyurl.com/knpaxcw

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New discovery in living cell signaling


By Lynn Yarris – The cellular signaling networks of living cells start with receptor proteins residing on a cell’s surface that detect and interact with the environment. Signals from these receptors are transmitted to chemical networks within the cell that process the incoming information, make decisions, and direct subsequent cellular activities.

“Although cellular signaling networks perform logical operations like a computer microprocessor, they do not operate in the same way,” Jay Groves, a chemist with Berkeley Lab’s Physical Biosciences Division and UC Berkeley’s Chemistry Department, says. “The individual computational steps in a standard computer are deterministic; the outcome is determined by the inputs. For the chemical reactions that compose a cellular signaling network, however, the molecular level outcomes are defined by probabilities only. This means that the same input can lead to different outcomes.” more> http://tinyurl.com/osa5jj9

Scientists unravel widespread natural adhesion system


R&D – Adhesion is an extremely important factor in living nature: insects can climb up walls, plants can twine up them, and cells are able to adhere to surfaces.

“We discovered that the actual moment of detachment—or more precisely: the moment when a defect in the contact area starts to develop up to its complete separation—lasts only a few micro-seconds.”

“This can be achieved only if a homogeneous stress distribution exists between the mushroom-shaped adhesive element and the surface,” Lars Heepe explains. Reaching such high speeds in this short time requires very much elastic energy, which can only be stored when stress in contact is homogeneously distributed. more> http://tinyurl.com/mj89lsp

New key to organism complexity identified


R&D Magazine – The enormously diverse complexity seen amongst individual species within the animal kingdom evolved from a surprisingly small gene pool. For example, mice effectively serve as medical research models because humans and mice share 80% of the same protein-coding genes. The key to morphological and behavioral complexity, a growing body of scientific evidence suggests, is the regulation of gene expression by a family of DNA-binding proteins called “transcription factors.” Now, a team of researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley has discovered the secret behind how one these critical transcription factors is able to perform—a split personality. more> http://tinyurl.com/bc5ahuu

Animal smarts: What do dolphins and dogs know?


BOOK REVIEW

The Genius of Dogs, Author: Brian Hare.

By Seth Borenstein – Dolphins are so distantly related to humans that it’s been 95 million years since we had even a remotely common ancestor. Yet when it comes to intelligence, social behavior and communications, some researchers say dolphins come as close to humans as our ape and monkey cousins.

“Think of it like a toolbox,” Duke University researcher Brian Hare said. “Some species have an amazing hammer. Some species have an amazing screwdriver.”

For dogs, a primary tool is their obsessive observation of humans and ability to understand human communication, Hare said. For example, dogs follow human pointing so well that they understand it whether it’s done with a hand or a foot; chimps don’t, said Hare, whose upcoming book is called “The Genius of Dogs.” more> http://tinyurl.com/7zs6m3a

Homo Politicus: Why Washington Never Learns


Cover of "On Aggression"

Cover of On Aggression

BOOK REVIEW

On Aggression, Author: Konrad Lorenz.

By Ralph Benko – Washington is awash with brains. Here are Think Tanks galore. Here are entire departments of federal agencies given over to nothing but research and analysis of how to solve our national (and local, and world) problems. PhD’s from every college in the land, perhaps world, are more than happy to drop everything to advise Washington “how to.” Brains galore.

Yes, here is inevitable partisanship. And yes, some Think Tanks were doomed at birth to the role of propagandist instead of rigorous analyst.

Chimpanzees, animals well known to be capable of learning by imitation, copy only higher-ranking members of their species. From a group of these apes, a low-ranking individual was taken and taught to remove bananas from a specially constructed feeding apparatus by very complicated manipulations. When this ape, together with his feeding apparatus, was brought back to the group, the higher-ranking animals tried to take away the bananas which he had acquired for himself, but none of them thought of watching their inferior at work and learning something from him. Then the higher-ranking chimpanzee was removed and taught to use the apparatus in the same way, and when he was put back in the group the other members watched him with great interest and soon learned to imitate him.

Washington is all about social dominance, not competence. more> http://is.gd/ItawTp

Scientists target bacteria ‘quorum sensing’ as route to antibacterial therapies


R&D Mag – During quorum sensing, bacteria produce, detect, and exchange signaling molecules known as autoinducers. This process is crucial to disease development because it ultimately controls the way that bacteria express “virulence factors“—the molecules that enable the bacteria to colonize a host, evade and compromise the host’s immune response, exit and enter cells, and obtain nutrients.

By studying how to inhibit quorum sensing, scientists may be able create antibacterial pharmaceuticals for a variety of ailments.

Recently, in part due to work performed at NSLS, researchers from Princeton University and the Howard Hughes Medical Institute learned how to block a quorum-sensing mechanism in the bacteria. more> http://twurl.nl/1pn07z?