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Comment by Dr. Krishna Kumari Challa on June 24, 2016 at 5:24am

Why is life not possible without water?
According to scientists...
Water is the basic unit of life and it is impossible to live without it. Ever wondered why? A new study has an explanation that may answer many such questions.

Ohio State University lead researcher Dongping Zhong along with his team shed new light on how and why water is essential to life. Zhong called the study a ‘major step forward’ in the understanding of water-protein interactions.

The study finds the strongest evidence that proteins can't fold themselves, but can fold into particular shapes to enable biological reactions.

Zhong, who is also a professor of chemistry and biochemistry, and his team used ultra-fast laser pulses to take snapshots of water molecules moving around a DNA polymerase, the kind of protein that helps DNA reproduce.
The findings showed how water molecules typically flow around each other at picosecond speeds, while proteins fold at nanosecond speeds, 1,000 times slower.
Previously, Zhong’s group demonstrated that the water molecules slow down when they encounter a protein. Water molecules are still moving 100 times faster than a protein when they connect with it.

In the new study, the researchers were able to determine that the water molecules directly touched the protein’s ‘side chains,’ the portions of the protein molecule that bind and unbind with each other to enable folding and function. The researchers were also able to note the timing of movement in the molecules.

Water can’t arbitrarily shape a protein, Zhong explained. Proteins can only fold and unfold in a few different ways depending on the amino acids they’re made of.

The study is published in the Proceedings of the National Academy of Sciences.

Comment by Dr. Krishna Kumari Challa on June 22, 2016 at 6:09am

Right use of hand sanitizers:
Q: How much time should we spend on cleaning our hands with sanitizers?
A scientific answer: To kill bacteria, rub for at least 15 to 30 seconds. After 45 seconds, you’re not doing much more good!
To provide more evidence-based guidance on hand sanitizer use, scientists from Geneva University Hospitals in Switzerland used E. coli bacteria to contaminate the hands of 23 health care workers. Then each person received a 3-milliliter squeeze of hand sanitizer. Participants were instructed to rub for different amounts of time, ranging from 10 to 60 seconds. The concentration of bacteria plunged after 10 and 15 seconds of friction, and then dropped slightly more after 30 seconds. But significant reductions in bacteria stopped at the 45-second mark — a curious finding that researcher Daniela Pires says she and her colleagues cannot explain.

The research was presented June 18 at ASM Microbe 2016, a meeting of the American Society for Microbiology and the Interscience Conference on Antimicrobial Agents and Chemotherapy.

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Q: Where do kids get their tooth decay microbes?

Scientific reply: Very little from mothers! Very limited quantity from the kisses mom's present their children!

New data show that the most common cause of tooth decay, the bacterium Streptococcus mutans (that cause dental caries), doesn’t always come from mother-to-child transmission.

Researchers from the University of Alabama at Birmingham studied 119 children in rural Alabama and 414 of their household contacts, tracking the path of S. mutans. Contrary to expectation, 40 percent of the children did not share any strains with their mothers. Instead, those strains usually overlapped with those of siblings and cousins. And 72 percent of children carried a strain of S. mutans that no one else in the family had, probably picked up from other children at school, day care or other locations. The research was presented June 17 at ASM Microbe 2016, a meeting of the American Society for Microbiology and the Interscience Conference on Antimicrobial Agents and Chemotherapy.

These findings indicate the importance of considering horizontal, as well as vertical, acquisition of S. mutans in prevention strategies for dental caries.

Comment by Dr. Krishna Kumari Challa on June 22, 2016 at 5:50am

Host Inflammatory Response to Mosquito Bites Enhances the Severity of Arbovirus Infection
Some mosquito-borne viruses appear to benefit from their victims’ immune responses to bug bites. Simply put, the body’s defensive reaction to pathogens, including dengue or West Nile, acts as a handmaiden for the viruses themselves. The first glimpses into exactly how these pathogens manage to hijack the body’s defense systems to enhance disease were revealed recently in a new mouse study.
When immune cells travel to the itchy, red site of a mosquito bite, they may inadvertently be infected with a mosquito-borne virus and then help spread the infection throughout the body. The resulting higher viral loads make the recipient sicker than would be the case if the virus were introduced without a bite. This revelation points to a potential new target for combating mosquito-borne diseases: the bite site itself.
The research team found that neutrophils, white blood cells that act as the body’s first line of defense against invaders, fuel inflammation at the bite site—thus trapping the virus there. A few hours later immune system responders called myeloid cells show up and become infected, and their cellular machinery is hijacked to replicate the virus. The immune-system soldiers then help spread the virus in the body, ultimately increasing morbidity and mortality.
Within a day, most mice that received a bite and subsequent virus-jab showed a 10-fold increase in virus numbers at the site of infection, compared with mice that had only been inoculated with virus. Such high viral loads allow the virus to more readily spread to remote tissues—and may also boost chances of transmitting the disease to other carriers. The higher virus count also proved lethal for many bite victims.
To confirm that neutrophils and myeloid cells help the virus thrive, the researchers conducted separate experiments that depleted the neutrophils or blocked myeloid cells from deploying. In both altered states the mice actually had lower viral loads and got less sick.
The new findings are particularly alluring for researchers because they may point to one target—the bite site—for fighting disease formation more effectively. “If you can inhibit bite inflammation, you could have a way of stopping viruses before they establish infection.

http://www.cell.com/immunity/fulltext/S1074-7613(16)30205-9

Comment by Dr. Krishna Kumari Challa on June 21, 2016 at 5:47am

The cells lining blood vessels in the brain form tight, tough-to-penetrate junctions that prevent toxic molecules from slipping into the brain.
The blood-brain barrier blocks cancer drugs from reaching tumor cells in the brain, creating a significant drug-delivery problem.
Now, preliminary results from a Phase I/II clinical trial suggest that a small implant that emits ultrasound waves can safely open the blood-brain barrier in people, potentially allowing drugs in (Sci. Transl. Med. 2016).
http://stm.sciencemag.org/content/8/343/343re2
A sound attack on brain tumors

Brain tumors are difficult to treat with chemotherapy because the blood-brain barrier greatly limits the delivery of drugs into the brain. Carpentier et al. have developed a pulsed ultrasound device, which they implanted into the skull of patients with glioblastoma, an aggressive and difficult to treat brain tumor, in a first-in-human trial. At regularly scheduled treatment sessions, the researchers activated the ultrasound device by connecting it to a power source, disrupting the blood-brain barrier long enough for subsequent chemotherapy to reach the brain. The authors confirmed that this approach was well tolerated and showed evidence of effectiveness to disrupt the blood-brain barrier, paving the way for further development of this therapeutic approach.

Comment by Dr. Krishna Kumari Challa on June 17, 2016 at 7:17am

Correction: Drinking very hot beverages can cause cancer of oesophagus says WHO
Researchers from the World Health Organisation (WHO) recently announced that coffee and herbal tea consumed at normal serving temperatures do not cause cancer and should not be labelled as carcinogenic.

The findings have knocked the cancer risk of these drinks down to zero, some 25 years after the WHO classified coffee as a possible carcinogen that could lead to bladder cancer. But the scientists still say that drinking extremely hot beverages might cause cancer of the oesophagus.
The conclusion was drawn after 23 scientists from the WHO's International Agency for Research on Cancer (IARC) reviewed more than 1,000 studies on coffee’s link to cancer. They report that, "there was inadequate evidence for the carcinogenicity of coffee drinking overall".
While the team didn’t go into detail about what "extremely hot" actually means, they do say that coffee consumed at "serving temperature" is fine. That means somewhere around 65 degrees Celsius (150 degrees Fahrenheit).

It’s not that the coffee suddenly becomes a carcinogen when heated to a high temperature, though. The researchers instead think that repeated scalding of the throat might lead to the formation of tumours, though evidence of this is currently limited.

These results suggest that drinking very hot beverages is one probable cause of oesophagal cancer and that it is the temperature, rather than the drinks themselves, that appears to be responsible.
To make a good cup of coffee, the water temperature while brewing should be somewhere between 90.5 degrees Celsius (195 degrees Fahrenheit) and 96 degrees Celsius (205 degrees Fahrenheit). When served, that temperature drops rather quickly. If it didn’t, the coffee would be too hot to comfortably drink, which is what you should avoid.

The basic rule of thumb here is that if the coffee burns you, wait a few minutes. Not only will this possibly reduce your risk of oesophageal cancer, it will make for a better coffee drinking experience, because who wants a side of pain with their morning cup of coffee?
The American Institute for Cancer Research says:

"Coffee’s possible link to cancer is a well-studied one, with over 1,000 studies on the topic. Early in the research, some studies hinted that coffee might increase cancer risk. Larger and more well-designed studies now suggest the opposite: it may be protective for some cancers."

Cancer isn’t the only disease that coffee could reduce. Earlier this year, researchers from the University of Southampton in the UK found positive results with liver disease, concluding that "having two cups of coffee a day appears to reduce the chances of developing the disease by 44 percent, based on data from 430,000 individuals spread over nine studies.
Let's be clear though - despite the wealth of research into the potential health benefits of coffee, nothing definitive has yet been found. It could be that we're trying really hard to find something beneficial in drinking coffee, because that would be very convenient, given how many of us do it. So we have to remain skeptical for now.

As the research continues, we might find real health benefits in our coffee drinking, but we really don’t need more of an excuse other than it tastes delicious and we're all really, really tired.

A summary of the IARC's findings was published in The Lancet Oncology.
http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(16)30239-X/fulltext

Comment by Dr. Krishna Kumari Challa on June 17, 2016 at 6:20am

Life-forming molecule found in interstellar space!
For the first time ever, scientists have detected a complex organic molecule called a chiral molecule in the reaches of interstellar space, and the discovery could greatly enhance our understanding of how biological life came to be on Earth – and maybe even life's prospects for evolving elsewhere in the galaxy.

The molecule in question, propylene oxide, was discovered in a gigantic gas cloud called Sagittarius B2, located about 390 light-years from the centre of the Milky Way. Sagittarius B2 has a mass around 3 million times the mass of the Sun, and now we know that this huge conglomeration contains chiral molecules in its midst, which had never previously been detected outside our Solar System.
This is the first molecule detected in interstellar space that has the property of chirality, making it a pioneering leap forward in our understanding of how prebiotic molecules are made in the Universe and the effects they may have on the origins of life.
Chirality is a geometric property of molecules, where asymmetric molecules display an almost identical chemical composition, but in an altered configuration – much like a mirror image – in what are called left-handed or right-handed versions.

It's a key chemical property of life on Earth, where every molecule that helps to form living things – such as amino acids, proteins, enzymes, and sugars – appears in only the left- or right-handed version of itself. This is called homochirality, and while it gives a biological benefit – as the matching molecules can fit better with one another to make larger organic structures – nobody knows how this 'chiral bias' came about.

As such, the discovery that chirality exists well outside our Solar System – with the detection of a 'handed' molecule in Sagittarius B2 – is a pretty big deal. Why? Because it could help explain why life essentially picks one molecular orientation over another.

"Propylene oxide is among the most complex and structurally intricate molecules detected so far in space."
Detecting this molecule opens the door for further experiments determining how and where molecular handedness emerges, and why one form may be slightly more abundant than the other."

The researchers identified the molecular signature of propylene oxide using the Green Bank Telescope (GBT) in West Virginia, with supporting observations coming from the CSIRO's Parkes radio telescope in Australia.
The team thinks complex molecules like this could form in the gas cloud from thin mantles of ice that develop on extremely tiny dust grains floating in space. These ice mantles would enable the molecules to form larger molecular structures, and help produce other chemical reactions within the cloud should the ice evaporate.

It sounds like a glacial process, but the fact that chiral molecules are doing this at all in deep space could help explain how they later make their way onto asteroids and comets – which might end up seeding the molecules on the surface of planets in the event of an impact.
In other words, these molecules – and the chance we now have to study them in isolation – could tell us a lot about where life comes from and how it evolves the way it does, including why it's so choosey about being a lefty or a righty.
The findings are published in Science.
http://science.sciencemag.org/content/early/2016/06/13/science.aae0328

Comment by Dr. Krishna Kumari Challa on June 15, 2016 at 9:28am

A nanomaterial-based, wide-color-varying fluorescent test paper much like classical pH test paper, has been developed to detect arsenic in water. The paper describing it was published in Analytical Chemistry.
To develop this test paper, the team used modified red quantum dots to obtain super-sensitivity to arsenic(III), or As(III). A small amount of cyan carbon dots with spectral blue-green components were added to produce a composited red fluorescence. The sensory solution was then printed onto a piece of filter paper.

In the presence of As(III), a range of colors is displayed—from red to cyan—clearly detecting a dosage scale as low as 5 parts per billion (ppb). According to World Health Organization’s guidelines, 10 ppb of As(III) in drinking water is considered safe.

http://pubs.acs.org/doi/abs/10.1021/acs.analchem.6b01248

Comment by Dr. Krishna Kumari Challa on June 15, 2016 at 8:47am

Laser-Scanning Tech Reveals Hidden Cities in Cambodia
Archaeologists in Cambodia say they uncovered previously unknown hidden cities near the Temples of Angkor Wat, which is part of one of the most important archaeological sites in Southeast Asia.

Using airborne laser scanning technology and covering an area of more than 734 square miles, experts revealed multiple cities that are around 900 to 1,400 years old. Some are so large that they rival the size of Cambodia’s capital, Phnom Penh.

“We have entire cities discovered beneath the forest that no one knew were there,” said Dr. Damian Evans, an Australian archaeologist with the Cambodian Archaeological Lidar (light detection and ranging) Initiative (CALI), which has been mapping the country.

This study, one of the largest of its kind, was an extension of a previous survey in 2012 that uncovered a large, interconnected system between cities. The results of the 2015 study, were released in full on 13th June, 2016, in the Journal of Archaeological Science, show the full scale of the city and subsequently the Khmer Empire, which at its peak in the 12th century, may have been the largest empire on Earth.

The discoveries not only expand on the collective history of the region, but also might give researchers clues into the empire’s collapse around the 15th century.

“There’s an idea that somehow the Thais invaded and everyone fled down south–that didn’t happen, there are no cities [revealed by the aerial survey] that they fled to,” Evans said. “It calls into question the whole notion of an Angkorian collapse.”

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Air Pollution Gives Storm Clouds a Stronger, Longer Life

More particulate matter in the air can build stronger, longer-lasting thunderstorms over the tropics, leading to more extreme storms. 

Clouds are built of tiny aerosol particles of dust or pollution from fossil fuel burning that suck up water vapor. Now these cloud particles with time they combine with each other, and become big. And when they become big, due to gravity, they fall out, and we call it rain.

When more aerosols seed the air, like in places with lots of industrial or agricultural pollution, the same amount of water vapor gets absorbed by a larger number of aerosols… meaning tinier-than-usual cloud particle size.

That's important, because it makes the cloud bigger and larger and stronger and live longer. Three to 24 hours longer. And it can produce more extreme storms when the rain finally comes. The study is in the Proceedings of the National Academy of Sciences. [Sudip Chakraborty et al., Relative influence of meteorological conditions and aerosols on the...]

A silver lining:  longer-lasting clouds also reflect more light back into space, which could end up somewhat cooling the planet!

Comment by Dr. Krishna Kumari Challa on June 15, 2016 at 8:42am

Tiny fossils show how environment affects species
Fossils resembling miniaturised popcorn that date back millions of years provide the first statistical evidence that number of species on Earth depends on how the environment changes, according to a new study.
By analysing the fossil record of microscopic aquatic creatures called planktonic foraminifera, the research from University of Southampton in the UK shows that environmental changes put a cap on species richness.
A changing environment alters how many species we see - the spatial gradient of more species in the tropics than at the poles is pervasive evidence for its large-scale impact.
Analyses of how species numbers have changed over time have assumed that any limit has always been the same, even through periods of massive climate upheaval.
New data reject this idea of fixed rules for competition among species and instead show that the limit to the number of species that can co-exist on Earth is much more dynamic. Climate and geology are always changing, and the limit changes with them.
While previous research typically focused individually on either biological, climate change or geological explanations, this new research examined the co-dependence of these factors on how species interact.
Looking at the fossil history of 210 evolutionary species of macroperforate planktonic foraminifera in the Cenozoic Era from 65 million years ago to the present, the study found that the number of species was almost certainly controlled by competition among themselves and probably kept within a finite upper limit.
Scientists used mathematical models to reveal how environmental changes influence both the rate of diversification among species and how many species can co-exist at once.
New results suggest that the world is full of species, but that the precise fullness varies through time as environmental changes alter the outcome of competition among species.
Scientists have long argued that environmental changes are likely to impact the number of species that can co-exist on Earth, but the fossil record is usually too incomplete for powerful statistical testing.
"Microfossils - especially planktonic foraminifera - give us a record with almost no gaps".
The study was published in the journal Ecology Letters.

Comment by Dr. Krishna Kumari Challa on June 15, 2016 at 6:00am

When we watch and listen to someone speak, our brain combines the visual information of the movement of the speaker’s mouth with the speech sounds that are produced by this movement.
A part of the continuous speech stream called the envelope, which is the slow rising and falling in the amplitude of the speech, was tracked in auditory areas of the brain. Conversely, the visual cortex tracked mouth movements. So what role does tracking the lip movements of a speaker play in speech perception?
Two areas of the brain actively track lip movements during speech. The first area was the visual cortex. This presumably tracks the lips as a visual signal. The second area was the left motor cortex. The ability of the motor cortex to track lip movements is important for understanding audiovisual speech. Some scientists suggest that the motor system helps to predict the upcoming sound signal by simulating the speaker’s intended mouth movement.
- eLifesciences

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