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Comment by Dr. Krishna Kumari Challa on December 11, 2013 at 6:07am

Coldest place on earth is at 'soul crushing' -93.2°C
Nasa satellites have found the coldest place on earth. At a desolate and remote ice plateau in East Antarctica, temperatures hit a "soul-crushing" -93.2 degrees Celsius (-135 degrees Fahrenheit). This beat the previous record of -89.2 degrees Celsius measured at the Vostok Research Station in East Antarctica on July 21, 1983.

"I've never been in conditions that cold and I hope I never am," Ted Scambos, lead scientist at the National Snow and Ice Data Center (NSIDC) said. "I am told that every breath is painful and you have to be extremely careful not to freeze part of your throat or lungs when inhaling."

The measurements were made between 2003 and 2013 by the MODIS sensor on board Nasa's Aqua satellite and during the 2013 Southern Hemisphere winter by Landsat 8, a new satellite launched early this year by Nasa and the US Geological Survey.

Scientists were puzzled by the fact that these very low temperature spots were found in a 1,000-kilometer long swath on the highest section of the East Antarctic ice divide.

http://timesofindia.indiatimes.com/home/science/Coldest-place-on-ea...

Comment by Dr. Krishna Kumari Challa on December 7, 2013 at 7:32am

According to IUCN counts, the countries with the highest numbers of species at risk of extinction are Ecuador (2,301), the U.S., Malaysia (1,226), Indonesia (1,206) and Mexico (1,074). India, China, Brazil, Tanzania and Australia round out the top ten; each of those nations has more than 900 species at risk of extinction on the IUCN Red List.
What do those numbers actually tell us? Both a lot and not much. Ecuador has the highest number of endangered species — not because the species there are more threatened but because the country made an intense effort over the last 15 years to evaluate its biodiversity. You can see the result of this work most notably in the assessment of Ecuador’s plants, which revealed that 1,843 of its native species are at risk.
The results of similar assessments are visible in other countries’ data. The U.S., for example, has the highest numbers of fishes (236) and mollusks (301) known to be at risk, as well as the highest number of recorded extinctions (257) on the IUCN Red List. Indonesia has largest number of mammals at risk (185), Brazil has the most birds (151), and Madagascar has the highest number of at-risk reptiles (136).

Of course numbers alone don’t tell the full story. Craig Hilton-Taylor, head of the IUCN Red List Unit, cautions that “you cannot use any of the country totals to show reliably which country has more threatened species than another” as they don’t reflect a country’s size, biodiversity levels, or other factors.
Meanwhile, an awful lot of species haven’t been assessed at all, or have only been assessed at national levels and not throughout their range, which may include several countries. Projects underway around the world will eventually help to fill that knowledge gap. “Brazil and South Africa are busy assessing all of their species,” Hilton-Taylor reports, “so those countries will suddenly have much higher numbers of threatened plants than all others because of the size of their respective floras.” Brazil is home to about 30,000 species and South African almost 20,000, so the Red List numbers will probably swell over the next few years.
http://blogs.scientificamerican.com/extinction-countdown/2013/12/05...

Comment by Dr. Krishna Kumari Challa on December 7, 2013 at 7:01am

Comment by Dr. Krishna Kumari Challa on December 6, 2013 at 10:02am

How mosquitoes are drawn to human skin and breath
Part 2
"Such compounds can play a significant role in the control of mosquito-borne diseases and open up very realistic possibilities of developing ways to use simple, natural, affordable and pleasant odors to prevent mosquitoes from finding humans," Ray said. "Odors that block this dual-receptor for CO2 and skin odor can be used as a way to mask us from mosquitoes. On the other hand, odors that can act as attractants can be used to lure mosquitoes away from us into traps. These potentially affordable 'mask' and 'pull' strategies could be used in a complementary manner, offering an ideal solution and much needed relief to people in Africa, Asia and South America -- indeed wherever mosquito-borne diseases are endemic. Further, these compounds could be developed into products that protect not just one individual at a time but larger areas, and need not have to be directly applied on the skin."

Currently, CO2 is the primary lure in mosquito traps. Generating CO2 requires burning fuel, evaporating dry ice, releasing compressed gas or fermentation of sugar -- all of which is expensive, cumbersome, and impractical for use in developing countries. Compounds identified in this study, like cyclopentanone, offer a safe, affordable and convenient alternative that can finally work with surveillance and control traps.
Source: University of California - Riverside

Comment by Dr. Krishna Kumari Challa on December 6, 2013 at 10:01am

How mosquitoes are drawn to human skin and breath
Part 1
Female mosquitoes, which can transmit deadly diseases like malaria, dengue fever, West Nile virus and filariasis, are attracted to us by smelling the carbon dioxide we exhale, being capable of tracking us down even from a distance. But once they get close to us, they often steer away toward exposed areas such as ankles and feet, being drawn there by skin odors. Why does the mosquito change its track and fly towards skin? How does it detect our skin? What are the odors from skin that it detects? And can we block the mosquito skin odor sensors and reduce attractiveness?

Recent research done by scientists at the University of California, Riverside can now help address these questions. They report on Dec. 5 in the journal Cell that the very receptors in the mosquito's maxillary palp that detect carbon dioxide are ones that detect skin odors as well, thus explaining why mosquitoes are attracted to skin odor -- smelly socks, worn clothes, bedding -- even in the absence of CO2.
"It was a real surprise when we found that the mosquito's CO2 receptor neuron, designated cpA, is an extremely sensitive detector of several skin odorants as well, and is, in fact, far more sensitive to some of these odor molecules as compared to CO2," said Anandasankar Ray, an associate professor in the Department of Entomology and the project's principal investigator. "For many years we had primarily focused on the complex antennae of mosquitoes for our search for human-skin odor receptors, and ignored the simpler maxillary palp organs."
Until now, which mosquito olfactory neurons were required for attraction to skin odor remained a mystery. The new finding -- that the CO2-sensitive olfactory neuron is also a sensitive detector of human skin -- is critical not only for understanding the basis of the mosquito's host attraction and host preference, but also because it identifies this dual receptor of CO2 and skin-odorants as a key target that could be useful to disrupt host-seeking behavior and thus aid in the control of disease transmission.
To test whether cpA activation by human odor is important for attraction, the researchers devised a novel chemical-based strategy to shut down the activity of cpA in Aedes aegypti, the dengue-spreading mosquito. They then tested the mosquito's behavior on human foot odor -- specifically, on a dish of foot odor-laden beads placed in an experimental wind tunnel -- and found the mosquito's attraction to the odor was greatly reduced.
Next, using a chemical computational method they developed, the researchers screened nearly half a million compounds and identified thousands of predicted ligands. They then short-listed 138 compounds based on desirable characteristics such as smell, safety, cost and whether these occurred naturally. Several compounds either inhibited or activated cpA neurons of which nearly 85 percent were already approved for use as flavor, fragrance or cosmetic agents. Better still, several were pleasant-smelling, such as minty, raspberry, chocolate, etc., increasing their value for practical use in mosquito control.
The researchers then zeroed in on two compounds: ethyl pyruvate, a fruity-scented cpA inhibitor approved as a flavor agent in food; and cyclopentanone, a minty-smelling cpA activator approved as a flavor and fragrance agent. By inhibiting the cpA neuron, ethyl pyruvate was found in their experiments to substantially reduce the mosquito's attraction towards a human arm. By activating the cpA neuron, cyclopentanone served as a powerful lure, like CO2, attracting mosquitoes to a trap.
http://esciencenews.com/articles/2013/12/05/how.mosquitoes.are.draw...

Comment by Dr. Krishna Kumari Challa on December 6, 2013 at 9:57am

Study shows how water dissolves stone, molecule by molecule
http://esciencenews.com/articles/2013/12/05/study.shows.how.water.d...

Comment by Dr. Krishna Kumari Challa on December 6, 2013 at 7:09am

The Replication Myth: Shedding Light on One of Science’s Dirty Little Secrets
http://blogs.scientificamerican.com/guest-blog/2013/12/04/the-repli...

Comment by Dr. Krishna Kumari Challa on December 4, 2013 at 9:44am

Just Thinking About Light Or Dark Can Change Your Pupil Size!
Animals involuntarily constrict or dilate their pupils if they are sensing either too much or not enough light entering the eye, respectively. Now, a new study from a pair of Norwegian researchers has found that simply imagining a scene that is either too brightly or dimly lit can affect the size of your pupils.

“Visual imagery is a private and subjective experience which is not accompanied by strongly felt or visible physiological changes,” explained study author Bruno Laeng, a psychological scientist from the University of Oslo. “It is a particularly difficult topic to research, as years of controversy about the nature of mental imagery testifies.”

Along with his University of Oslo colleague Unni Sulutvedt, Laeng performed a series of experiments to determine if they could access subjective mental imagery by tracking the size of pupils. The Norwegian team started by having participants look at a display while triangles of different degrees of brightness were shown. Later, participants were asked to actively imagine those triangles.

The researchers wrote in their report in the journal Psychological Science that participants’ pupils would vary in size according to an original triangle’s brightness. For example, when imagining brighter triangles, participants’ pupils were smaller and when imagining darker triangles, participants’ pupils were dilated.

In another series of experiments, participants’ pupils also dilated or constricted when they were told to picture a dark room or a face in the sun compared with a face in the shade. Additional experiments demonstrated that the results were not due to voluntary changes in pupil size or the mental effort spent imagining scenes, the researchers said.

“Because humans cannot voluntarily constrict the eyes’ pupils, the presence of pupillary adjustments to imaginary light presents a strong case for mental imagery as a process based on brain states similar to those which arise during actual perception,” Laeng said.

The research team suggested that their findings could be applied to future studies involving the mental experiences of animals, babies, and even patients with neurological problems.

http://www.redorbit.com/news/health/1113018564/mental-imagery-affec...

Comment by Dr. Krishna Kumari Challa on December 4, 2013 at 9:42am

Study shows energy drinks 'significantly increased' heart contractions

A new study has showed that energy drinks can affect the heart beats of even healthy adults hours after consumption.
Test subjects were monitored using an MRI scanner after drinking the heavily caffeinated beverages, with researchers from the University of Bonn reporting the drinks “significantly increased” heart contraction rates.

"Until now, we haven't known exactly what effect these energy drinks have on the function of the heart," said Dr. Jonas Dörner, one of the study’s authors. “There are concerns about the products' potential adverse side effects on heart function, especially in adolescents and young adults, but there is little or no regulation of energy drink sales.”

"Usually energy drinks contain taurine and caffeine as their main pharmacological ingredients. The amount of caffeine is up to three times higher than in other caffeinated beverages like coffee or cola.”

Dörner also noted that the side-effects of consuming large amounts of caffeine could include “a rapid heart rate, palpitations, rise in blood pressure and, in the most severe cases, seizures or sudden death”.

http://www.independent.co.uk/news/science/study-shows-energy-drinks...

Comment by Dr. Krishna Kumari Challa on December 4, 2013 at 9:40am

Men And Women’s Brains Are ‘Strikingly’ Complimentary
Men and women have ‘striking’ differences in their neural wiring that might explain some of the behavioral differences between the two sexes, according to a study published Monday in the Proceedings of National Academy of Sciences.

The study was one of the largest to date to create to compare the connectomes, neural maps of the brain, of men and women.

The results revealed that men have far greater neural connectivity from front to back and within one brain hemisphere, suggesting their brains are structured to facilitate connectivity between perception and coordinated action. However, in females, this wiring goes between the left and right brain hemispheres, suggesting that women facilitate communication between the analytic and intuitive parts of the brain, the researchers said.

“These maps show us a stark difference – and complementarity – in the architecture of the human brain that helps provide a potential neural basis as to why men excel at certain tasks, and women at others,” said study leader Ragini Verma, PhD, an associate professor in the department of Radiology at the Perelman School of Medicine at the University of Pennsylvania.

For instance, on average, men are more likely better at learning and performing a single task at hand, like cycling or navigating directions, whereas women have superior memory and social cognition skills, making them better equipped for multitasking and creating solutions that work for a group. In other words, they have what’s called a mentalistic approach.

The human brain is a complex roadmap of neural pathways linking many networks that help us process information and react accordingly, with behavior controlled by several of these sub-networks working in conjunction.

Although previous research has revealed gender differences in the brain, the current study is the first to show the neural wiring connecting regions across the whole brain among a large population.

http://www.redorbit.com/news/science/1113017910/male-and-female-bra...

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