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Comment by Dr. Krishna Kumari Challa on April 11, 2014 at 2:18pm

Did Life Originate At Deep Sea Vents?
Recent research by geochemists Eoghan Reeves, Jeff Seewald, and Jill McDermott at Woods Hole Oceanographic Institution (WHOI) is the first to test a fundamental assumption of this ‘metabolism first’ hypothesis, and finds that it may not have been as easy as previously assumed. Instead, their findings could provide a focus for the search for life on other planets. The work is published in Proceedings of the National Academy of Science.

In 1977, scientists discovered biological communities unexpectedly living around seafloor hydrothermal vents, far from sunlight and thriving on a chemical soup rich in hydrogen, carbon dioxide, and sulfur, spewing from the geysers. Inspired by these findings, scientists later proposed that hydrothermal vents provided an ideal environment with all the ingredients needed for microbial life to emerge on early Earth. A central figure in this hypothesis is a simple sulfur-containing carbon compound called “methanethiol” – a supposed geologic precursor of the Acetyl-CoA enzyme present in many organisms, including humans. Scientists suspected methanethiol could have been the “starter dough” from which all life emerged.

http://www.redorbit.com/news/science/1113118229/did-life-originate-...

Comment by Dr. Krishna Kumari Challa on April 10, 2014 at 6:51am

Scientists have found that drinking water can activate different areas of the brain, depending on whether the subject is thirsty or satiated.

Brains Know When To Stop Drinking Water
Our brains are hardwired to stop us from drinking more water than is healthy, according to a new brain imaging study led by The University Of Melbourne and the Florey Institute of Neuroscience and Mental Health in Australia.

The study found a ‘stop mechanism’ that controlled the brain signals telling an individual to stop drinking water when no longer thirsty, as well as the effects of drinking more water than required on the brain.

Published in Proceedings of the National Academy of Sciences, the research used magnetic resonance imaging to scan two physiological conditions of the brain, starting with scanning brain regions during the experience of thirst. Participants were then removed from the scanner and asked to drink to satiation or ‘overdrink’ and returned for further scanning.

Different areas of the brain involved in emotional decision-making were activated when people drank water after becoming thirsty and when study participants followed instructions to keep drinking when no longer thirsty.” 



“The brain regions determining the signals to stop drinking have not previously been recognized in this context. It identifies an important component in regulation and this ‘stop mechanism’ may prevent complications from excessive water intake”.
Scientists have found that drinking water can activate different areas of the brain, depending on whether the subject is thirsty or satiated.

Our brains are hardwired to stop us from drinking more water than is healthy, according to a new brain imaging study led by The University Of Melbourne and the Florey Institute of Neuroscience and Mental Health in Australia.

The study found a ‘stop mechanism’ that controlled the brain signals telling an individual to stop drinking water when no longer thirsty, as well as the effects of drinking more water than required on the brain.

Published in Proceedings of the National Academy of Sciences, the research used magnetic resonance imaging to scan two physiological conditions of the brain, starting with scanning brain regions during the experience of thirst. Participants were then removed from the scanner and asked to drink to satiation or ‘overdrink’ and returned for further scanning.


Researcher Professor Derek Denton from the Faculty of Medicine, Dentistry and Health Sciences at the University of Melbourne said the study provided insight into the human instincts that determine survival behavior and are also of medical importance. 



“Different areas of the brain involved in emotional decision-making were activated when people drank water after becoming thirsty and when study participants followed instructions to keep drinking when no longer thirsty.” 



“The brain regions determining the signals to stop drinking have not previously been recognized in this context. It identifies an important component in regulation and this ‘stop mechanism’ may prevent complications from excessive water intake,” he said.

Overdrinking can reduce the salt concentration of the blood that can result in the swelling of the brain, a potentially fatal condition. Also known as polydipsia, it has been found in some patients with schizophrenia and in some marathon runners.
“This is a study of elements of gratification and how the body programs accurate behavior. In revealing aspects of gratification control, the data are relevant to study the gratification of other instincts, such as food intake, salt intake and sexual behavior”.
''Regional brain responses associated with drinking water during thirst and after its satiation''
http://www.pnas.org/content/111/14/5379

Comment by Dr. Krishna Kumari Challa on April 10, 2014 at 6:43am

Researchers have found that inflammation of the nervous system is higher in patients with chronic fatigue syndrome (CFS) than in healthy people.

The study, published in The Journal of Nuclear Medicine, suggests that using positron emission tomography (PET) scans to detect brain inflammation could be an objective diagnostic test for CFS.
''Toward a clearer diagnosis of chronic fatigue syndrome''
http://www.riken.jp/en/pr/press/2014/20140404_1/

Comment by Dr. Krishna Kumari Challa on April 10, 2014 at 6:41am

Scientists in Taiwan has uncovered how a viral DNA polymerase breaks the golden Watson-Crick rule.
Replication of DNA occurs in all living organisms and forms the basis of biological inheritance. DNA is formed and replicated through the pairing of the four nucleotides, adenine (A), thymine (T), cytosine (C) and guanine (G) in a specific pattern: A pairs with T and C pairs with G. This is known as the Watson-Crick base-pairing rule. The synthesis of new strands of DNA is facilitated by enzymes called DNA polymerases.

Scientists have long been fascinated by the fidelity of the DNA polymerase reaction — the way in which the pairing rule is invariably followed. However, in recent years scientists have discovered polymerases that do not follow the Watson-Crick rule, and have sought explanations for how these enzymes function.

Recently published in the chemistry periodical Journal of American Chemistry, Tsai’s research investigated a DNA polymerase from the African swine fever virus named Pol X. Pol X is unusual because it can get G to pair with itself, on top of following the Watson-Crick rule.
In conventional DNA polymerization, the enzyme firsts binds to the DNA, and only subsequently the free nucleotides. This allows the DNA sequence to determine which nucleotide binds, restricting the binding to nucleotides complementary to the DNA template. The team found, however, that Pol X is able to bind nucleotides in the absence of DNA.

“Kinetic studies suggested that Pol X does not follow the established mechanistic paradigm that DNA polymerases bind DNA before binding to a nucleotide,” Tsai explained.

The results demonstrate the first solution structural view of DNA polymerase catalysis and a novel mechanism for non-Watson-Crick incorporation by a low-fidelity DNA polymerase.
''How a Low-Fidelity DNA Polymerase Chooses Non-Watson–Crick from Watson–Crick Incorporation''
http://pubs.acs.org/doi/abs/10.1021/ja4102375

Comment by Dr. Krishna Kumari Challa on April 10, 2014 at 6:38am

An interdisciplinary research team of researchers has designed ultra-fast electrical circuits using quantum tunneling.
Quantum Tunneling Speeds Up Circuits
- http://www.nus.edu.sg/

Comment by Dr. Krishna Kumari Challa on April 10, 2014 at 6:07am

Hand Soap Ingredient Can Up Body Bacteria Burden
Residues of the antimicrobial agent triclosan can paradoxically boost bacterial growth in our bodies, by giving microbes a comfortable biofilm in which to rest.
http://www.scientificamerican.com/podcast/episode/triclosan-biofilm...

Comment by Dr. Krishna Kumari Challa on April 10, 2014 at 6:03am

Comment by Dr. Krishna Kumari Challa on April 9, 2014 at 7:05am

A speedy particle from beyond the solar system is the new record holder for the highest-energy neutrino ever detected, researchers from the IceCube experiment announced April 7 at a meeting of the American Physical Society.

Buried under an Antarctic glacier, IceCube consists of thousands of detectors looking for flashes of light triggered when neutrinos, particles that barely interact with anything as they cruise the cosmos, collide with the ice. Incorporating a year’s worth of new data, researchers announced that IceCube detected nine additional high-energy neutrinos for a total of 37.

One of the nine neutrinos struck the ice with a record 2 million billion electron volts of energy. Continuing the tradition of naming neutrinos after Muppets, the scientists named it Big Bird.
https://www.sciencenews.org/blog/science-ticker/meet-big-bird-highe...

Comment by Dr. Krishna Kumari Challa on April 9, 2014 at 7:03am

A study found that up to half of 2 year olds were picky eaters. Food choosiness isn’t just a way for a kid to drive a parent mad. Pickiness actually makes sense: When kids are bombarded with new and unusual foods, sticking with safe, familiar choices is a good way to avoid eating something dangerous.
''Prevalence of picky eaters among infants and toddlers and their caregivers’ decisions about offering a new food''
http://www.journals.elsevierhealth.com/periodicals/yjada/article/S0...
Taste preferences start in the womb. Fetuses slurp up amniotic fluid, seasoned with whatever mom just ate. (You’re welcome for the seasoned amniotic fluid imagery.) These flavors, such as carrots or garlic, tap into the fetus’s taste system, which begins to form in the first trimester. The more exposure to a certain taste, the more a baby is to eventually like it. Babies whose mothers drank a lot of carrot juice while pregnant and breastfeeding preferred carrot-flavored cereal, for instance.
Familiarity breeds yum, in this case. And I was amazed when I saw just what familiarity means to young kids. Some recent work suggests that to get kids used to a certain flavor, that food should be offered and tasted anywhere from six to 14 times. That’s a whole lot of tasting. And lots of parents don’t have that kind of patience. Most parents reported giving their kids a new food three to five times before giving up. Only 6 to 9 percent of parents kept offering a new food six to 10 times.

This kind of intense exposure can transform a reviled food into a familiar one, making the kid more likely to eat it. One study had parents give their child a tiny taste of one of six raw vegetables (carrots, cucumbers, tomatoes, celery, green peppers or red peppers) every day for 14 days. After this intense tasting exposure, kids were more likely to eat the veggie, the researchers found.

''If your kid hates broccoli, try, try again
Repeated exposure to foods may be the antidote to picky eating''
https://www.sciencenews.org/blog/growth-curve/if-your-kid-hates-bro...

Comment by Dr. Krishna Kumari Challa on April 9, 2014 at 5:59am

Stress alters children's genomes

Poverty and unstable family environments shorten chromosome-protecting telomeres in nine-year-olds.
Growing up in a stressful social environment leaves lasting marks on young chromosomes, a study of African American boys has revealed. Telomeres, repetitive DNA sequences that protect the ends of chromosomes from fraying over time, are shorter in children from poor and unstable homes than in children from more nurturing families.
http://www.nature.com/news/stress-alters-children-s-genomes-1.14997

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