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Comment by Dr. Krishna Kumari Challa on April 27, 2014 at 5:49am

Skin Layer Grown From Human Stem Cells Could Replace Animals In Drug, Cosmetics Testing

British scientists have developed the first labgrown epidermis — the outermost skin layer — which may replace animal testing. The new epidermis offers a cost-effective alternative lab model for testing drugs and cosmetics , and could also help to develop new therapies for rare and common skin disorders.
An international team led by King's College London and the San Francisco Veteran Affairs Medical Center has developed the epidermis with a functional permeability barrier similar to real skin. The new epidermis was grown from human pluripotent stem cells.
The epidermis forms a protective interface between the body and its external environment . The research used reprogrammed skin cells — which offer a way to produce an unlimited supply of the main type of skin cell found in the epidermis . They grew the skin cells in a low humidity environment, which gave them a barrier similar to that of true skin.

Comment by Dr. Krishna Kumari Challa on April 27, 2014 at 5:48am

Channel Makeover Bioengineered To Switch Off Neurons
Scientists have bioengineered, in neurons cultured from rats, an enhancement to a cutting edge technology that provides instant control over brain circuit activity with a flash of light.
Deisseroth’s team had pioneered the use of light pulses to control brain circuitry in animals genetically engineered to be light-responsive — optogenetics. Genes that allow the sun to control light-sensitive primitive organisms like algae, melded with genes that make fluorescent marker proteins, are fused with a deactivated virus that delivers them to specific types of neurons which they become part of — allowing pulses of light to similarly commandeer brain cells.

When a neuron fires depends on the balance of ions flowing across the cell membrane, so being able to experimentally control this cellular machinery is critical for understanding how the brain works. But until now, the optogenetic tools for turning off neurons have been much less powerful than for turning them on — a weak inhibitory pump, moving only one ion per photon of light, versus an efficient excitatory channel.

Stanford bioengineers and their colleagues recently discovered the crystal structure of channelrhodopsin, the protein borrowed from algae to achieve optogenetic control of neurons. To transform this excitatory channel into an effective inhibitory channel, the team systematically introduced mutations into the channel’s gene, gradually reshaping its structure through molecular engineering into one with optimal inhibitory properties. To become an effective inhibitory channel, its central pore needed to be lined with positive instead of negatively charged amino acids to be converted from a cation (positive ion)-conducting into an anion (negative ion) -conducting channel.

It turns out that there are economies of scale afforded by the transformed channel — the more the inhibition, the less light required to achieve the desired biological effect. This raises possible future therapeutic applications, such as in the management of pain, said Deisseroth.
http://www.nih.gov/news/health/apr2014/nimh-24.htm

Comment by Dr. Krishna Kumari Challa on April 26, 2014 at 7:26am

Comment by Dr. Krishna Kumari Challa on April 25, 2014 at 9:05am

Comment by Dr. Krishna Kumari Challa on April 25, 2014 at 8:41am

Pain makes female mice less amorous, but males ignore burning injections in pursuit of females, a new study finds. The results, published in the April 23 Journal of Neuroscience, highlight stark differences between male and female sexual behavior in mice.
Pain Reduces Sexual Motivation in Female But Not Male Mice
http://www.jneurosci.org/content/34/17/5747

Comment by Dr. Krishna Kumari Challa on April 25, 2014 at 8:39am

Gene therapy with electrical pulses spurs nerve growth
Electrical current from a cochlear implant has guided corrective genetic material into inner ear cells and stimulated nerve regeneration in deaf guinea pigs. The treatment improved the animals’ hearing sensitivity and range, researchers report April 24 in Science Translational Medicine. The gene therapy technique, which does not use viruses that could induce immune reactions, holds promise for improving the hearing of people with cochlear implants. It may also have applications in deep brain stimulation, the scientists say.
https://www.sciencenews.org/blog/science-ticker/gene-therapy-electr...

Comment by Dr. Krishna Kumari Challa on April 25, 2014 at 8:38am

Could the menstrual cycle have shaped the evolution of music?
Sexual selection theory posits fertility role in complex music
Menstrual cycle phase alters women's sexual preferences for composers of more complex music
Over 140 years ago Charles Darwin first argued that birdsong and human music, having no clear survival benefit, were obvious candidates for sexual selection. Whereas the first contention is now universally accepted, his theory that music is a product of sexual selection through mate choice has largely been neglected. Here, I provide the first, to my knowledge, empirical support for the sexual selection hypothesis of music evolution by showing that women have sexual preferences during peak conception times for men that are able to create more complex music. Two-alternative forced-choice experiments revealed that woman only preferred composers of more complex music as short-term sexual partners when conception risk was highest. No preferences were displayed when women chose which composer they would prefer as a long-term partner in a committed relationship, and control experiments failed to reveal an effect of conception risk on women's preferences for visual artists. These results suggest that women may acquire genetic benefits for offspring by selecting musicians able to create more complex music as sexual partners, and provide compelling support for Darwin's assertion ‘that musical notes and rhythm were first acquired by the male or female progenitors of mankind for the sake of charming the opposite sex’.
http://rspb.royalsocietypublishing.org/content/281/1784/20140403

Comment by Dr. Krishna Kumari Challa on April 25, 2014 at 8:18am

Citizen scientists match research tool when counting sharks
Shark data collected by citizen scientists may be as reliable as data collected using automated tools, according to results published April 23, 2014, in the open access journal PLOS ONE by Gabriel Vianna from The University of Western Australia and colleagues.
http://blogs.plos.org/citizensci/2012/12/31/top-citizen-science-pro...

Comment by Dr. Krishna Kumari Challa on April 25, 2014 at 8:16am

Ocean microbes display remarkable genetic diversity
Scientists in MIT's Department of Civil and Environmental Engineering (CEE) recently performed a cell-by-cell genomic analysis on a wild population of Prochlorococcus living in a milliliter -- less than a quarter teaspoon -- of ocean water, and found hundreds of distinct genetic subpopulations.
- Massachusetts Institute of Technology

Comment by Dr. Krishna Kumari Challa on April 25, 2014 at 8:14am

Breakthrough harnesses light for controlled chemical reaction
When chemist Tehshik Yoon looks out his office window, he sees a source of energy to drive chemical reactions. Plants "learned" to synthesize chemicals with sunlight eons ago; Yoon came to the field a bit more recently. But this week, in the journal Science, he and three collaborators detail a way to use sunlight and two catalysts to create molecules that are difficult to make with conventional techniques.

In chemistry, heat and ultraviolet (UV) light are commonly used to drive reactions. Although light can power reactions that heat cannot, UV has disadvantages, says Yoon, a chemistry professor at University of Wisconsin-Madison. The UV often used in industry carries so much energy that "it's dangerous to use, unselective, and prone to making unwanted by-products."

Many chemicals exist in two forms that are mirror images of each other, and Yoon is interested in reactions that make only one of those images.

"It's like your hands," Yoon says. "They are similar, but not identical; a left-hand glove does not fit the right hand. It's the same way with molecules in biology; many fail unless they have the correct 'handedness,' or 'chirality.'"

The pharmaceutical industry, in particular, is concerned about controlling chirality in drugs, but making those shapes is a hit-or-miss proposition with UV light, Yoon says.

He says the new technique answers a question posed by a French chemist in 1874, who suggested using light to make products with controlled chirality. "Chemists could never do that efficiently, and so the prejudice was that it was too difficult to do."
- University of Wisconsin-Madison

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