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Comment by Dr. Krishna Kumari Challa on December 12, 2016 at 8:43am

Effects of c- section births on evolution

Caesarean section (or C-section) deliveries can save lives when babies are too large to be born naturally - or if there are other health complications - but they also appear to be affecting how humans are evolving, scientists report.

In the past, larger babies and mothers with narrow pelvis sizes might both have died in labour.  Thanks to C-sections, that's now a lot less likely, but it also means that those 'at risk' genes from mothers with narrow pelvises are being carried into future generations.

Cases where a baby can't fit through the birth canal have increased from 30 in 1,000 births in the 1960s to 36 in 1,000 today because of this C-section effect, according to estimates from researchers at the University of Vienna in Austria.  That's a significant shift in just half a century.

"Without modern medical intervention, such problems often were lethal and this is, from an evolutionary perspective, selection.

The team used a mathematical model based on obstructed child birth data to reach their estimates.

More detailed studies would be required to actually confirm the link between C-sections and evolution, as all we have now is a hypothesis based on the birth data. But Mitteroecker and his colleagues say it's important to consider the effect the rise in these procedures is having.

There are already a few conflicting evolutionary forces at work here, scientists think, in what's known as the obstetrical dilemma.

The 'dilemma' is that the larger a baby is when it's born, the more likely its chances of survival. At the same time, women have evolved with smaller pelvic sizes to aid upright walking and to limit the chances of premature births.

Both evolutionary pressures are working to try and keep babies healthy... but they're also working against each other.

"One side of this selective force - namely the trend towards smaller babies - has vanished due to caesarean sections.

This evolutionary trend will continue but perhaps only slightly and slowly.

Cliff-edge model of obstetric selection in humans

http://www.pnas.org/content/early/2016/11/29/1612410113

Comment by Dr. Krishna Kumari Challa on December 12, 2016 at 7:13am

The BIG Bell Test.

The experiment - coordinated by ICFO-The Institute of Photonic Sciences in Spain - powered by human randomness is aimed to demonstrate that the microscopic world is in fact as strange as quantum physics predicts. 

Predictions such as particles behaving in a random way, determining their properties only when we look at them; strange instantaneous interactions at a distance - were all questioned by Einstein, who rejected them completely. 

During the 48 hours in which it was November 30th at different place on the planet, participants contributed to the initiative, generating sequences of zeros and ones as random as possible through a video game. 

Each of these bits was used to control in real-time the experimental conditions of the labs. 

They moved mirrors, polarising filters, waveplates - elements located on optical tables and that affect the type of measurements that are made on the different quantum systems in each lab. 

Together all the participants provided scientists with millions of unpredictable, independent decisions which were used to measure their particles. 

This independence is a crucial feature for the conclusions of the Bell tests to be valid. 

Using the sequences provided by the participants, the scientists have been able to verify whether or not their particles were intertwined by the "spooky action at a distance" that Einstein could not accept. 

The Bell test states that experimentalists have to do their measurements with the help of human decisions and calculate the "Bell parameter" (known as the parameter S). 

If the world is, as Einstein believes, predictable and without "spooky actions at a distance", then S cannot be greater than 2. Otherwise, the inequality has been violated, indicating the presence of intrinsically quantum phenomena. 

By 13:00 Central European Time (CET), the minimum number of participations needed to assure enough bits to power the experiments had already been surpassed, registering above 1,000 bits per second in a stable manner over the course of several hours. 

By early afternoon, some of the labs had been able to obtain preliminary results, confirming violations of Bell's inequality, and thus refuting Einstein, giving their complete support to the predictions of quantum physics. 

"The project required contributions from many people in very different areas: the scientists pushed their experiments to new limits, the public very generously gave us their time in support of science, and educators found new ways to communicate between these two groups," said Morgan Mitchell, professor at ICFO.

Comment by Dr. Krishna Kumari Challa on December 12, 2016 at 6:54am

5th world conference on research integrity

May 18th to 31st, 2017, Amsterdam, The Nederlands

To  promote the integrity of research – from proper design methodology to ethical submission and publication to making research data available for re-use.

Themes include transparency and accountability, building on the premise that the honesty and reliability of research are best served by openly sharing all aspects of research and by taking personal responsibility for it. It also draws attention to the urgent need to fight questionable research practices. 

More details here: http://www.wcri2017.org/

Comment by Dr. Krishna Kumari Challa on December 6, 2016 at 8:30am

The 'BIG Bell Test: worldwide quantum experiments powered by human randomness' aims to conduct a series of quantum experiments in labs around the world that, for the first time, will be controlled by human decisions made by

volunteers across the world. On November 30th, for the first time, participants around the world took part in a unique worldwide experiment with the aim of testing the laws of quantum physics. 

Coordinated by ICFO-The Institute of Photonic Sciences, 12 laboratories from around the world collaborated for the BIG Bell Test: worldwide quantum experiments powered by human randomness with the aim of demonstrating experimentally that the nanoscale world is as strange as quantum physics predicts, consisting of particles in superstates that collapse only when observed; strange instantaneous interactions at a distance; predictions that were questioned by Einstein, who rejected them completely.

During the 48 hours during which it was November 30th somewhere on the planet, participants contributed to the initiative, generating sequences of zeros and ones through a video game to produce sequences of numbers that were as random as possible. Each of these bits was used to control the experimental conditions of the labs in real time. They moved mirrors, polarizing filters, waveplates—elements located on optical tables that affected the types of measurements made on the quantum systems in each lab.

All the participants provided scientists with millions of unpredictable, independent decisions that were used to measure their particles. This independence is a crucial feature for the conclusions of the Bell tests to be valid. Using the sequences provided by the participants, the scientists verified whether or not their particles were intertwined by the quantum entanglement that Einstein could not accept. In a nutshell, the Bell test states that experimentalists have to conduct their measurements with the help of human decisions and calculate the "Bell parameter" (also known as the parameter S). If the universe is predictable and without quantum entanglement, then S cannot be greater than two. That is, S should always be less than two. Otherwise, the inequality has been violated, indicating the presence of intrinsic quantum phenomena.

By 13:00 CET, the minimum number of participations needed to provide enough bits to power the experiments had already been surpassed, registering above 1000 bits per second in a stable manner over the course of several hours. By early afternoon CET, some of the labs had been able to obtain preliminary results, confirming violations of Bell's inequality, and thus confirming the predictions of quantum physics.

 

Comment by Dr. Krishna Kumari Challa on November 24, 2016 at 8:44am

Must read ... An open letter from women of science

 Women scientists' pledge...

https://500womenscientists.org/#our-pledge

Comment by Dr. Krishna Kumari Challa on November 24, 2016 at 8:05am

How what you eat effects your gut...

Mucus plays a major role in your gut. There are antimicrobial peptides and proteins that are present in the environment. Bacteria live in your gut and forage on the carbohydrates. And it's a lubricant, it helps sweep contents down the GI tract, without injuring the epithelial layer. In the colon, the mucus builds a wall: a barrier against friendly bacteria, as well as pathogens that could be transiting through. But here's the problem: your gut bacteria may chew right through that wall—if you skimp on fiber in your diet. 

In the studies conducted on mice, extreme high-fiber diet helped keep the mucus barrier intact. But in mice that had zero fiber—or the kind of soluble fiber typically added to processed foods—the fiber-eating members of the gut dwindled. Their absence opened up more space for mucus-munching bacteria, which increased in number, and tore through the protective mucus wall—leaving intestinal cells open for microbial attack. The study's published in the journal Cell. 

Your diet could predispose how you react to an enteric pathogen. Eating natural vegetables, raw vegetables, cooked veggies, whole grains, is definitely good for you. Interestingly, the mice's gut bacteria bounced back within a day to a change in diet. 

A Dietary Fiber-Deprived Gut Microbiota Degrades the Colonic Mucus Barrier and Enhances Pathogen Susceptibility

http://www.cell.com/cell/abstract/S0092-8674(16)31464-7

Comment by Dr. Krishna Kumari Challa on November 18, 2016 at 8:43am

Scientists have hacked a plant's genes to make it use sunlight more efficiently — a breakthrough that could eventually dramatically increase the amount of food grown.

Photosynthesis is how plants convert sunlight, carbon dioxide and water into food. But it's a very inefficient process, using less than 1 percent of the energy available.

By genetically modifying part of the plant's protective system, which kicks into gear when too much sunlight beams down, scientists were able to increase leaf growth between 14 and 20 percent in experiments with tobacco plants, according to a study published on 18th Nov., 2016 in the journal Science .

http://science.sciencemag.org/content/354/6314/857

Comment by Dr. Krishna Kumari Challa on November 18, 2016 at 8:31am

Popular heartburn drugs —  under investigation for possible links to dementia, kidney and heart problems — have a new health concern to add to the list. An analysis of almost 250,000 medical records in Denmark has found an association with stroke.

Researchers from the Danish Heart Foundation in Copenhagen studied patients undergoing gastric endoscopy from 1997 to 2012. About 9,500 of all patients studied suffered from ischemic strokes, which occur when a blood clot blocks a blood vessel in the brain.

Overall, the risk of stroke was 21 percent higher in patients taking a proton pump inhibitor, a drug that relieves heartburn, the researchers reported November 15 during the American Heart Association’s annual meeting. While those patients also tended to be older and sicker to start with, the level of risk was associated with dose, the researchers found. People taking the lowest drug doses (between 10 and 20 milligrams a day, depending on the drug) did not have a higher risk. At the highest doses, though, Prevacid (more than 60 mg/day) carried a 30 percent higher risk and Protonix (more than 80 mg/day) a 94 percent higher risk. For Prilosec and Nexium, stroke risk fell within that range.  

T.S. Sehested et al. Proton pump inhibitor use increases the associated risk of first-ti.... American Heart Association Scientific Sessions, New Orleans, November 15, 2016.

M. Rosen. Heartburn drugs can damage cells that line blood vessels. Science News. Vol. 189, June 11, 2016, p. 8.

V. Savarino et al. The appropriate use of proton pump inhibitors (PPIs): Need for a re.... European Journal of Internal Medicine. Published online October 23, 2016. doi: 10.1016/j.ejim.2016.10.007. 

Comment by Dr. Krishna Kumari Challa on November 18, 2016 at 7:11am

Birds and other marine animals are eating the plastic we discard into the ocean as it breaks down into small pieces.Why? 

Two scientists from the University of California, Davis think they have the answer: the birds are drawn by the smell of a dimethyl sulfide released by plastic -- the same chemical released by phytoplankton.

Some birds (which the paper describes as “procellariiform species”) have a strong sense of smell, and respond to a certain chemical, dimethyl sulfide, as a cue to find their prey. And in a study released on 16th Nov., 2016 in Science Advances, their suspicions were confirmed.

Dimethyl sulfide is released by phytoplankton as it gets eaten by a predator or breaks down in the ocean or on shore, signaling to these birds and others to come eat the phytoplankton’s predators (like krill).

Dr. Nevitt and Mr. Savoca found that the chemical is also released when tiny pieces of plastic are present in the ocean, often a result of “biofouling,” which describes the process when algae colonizes pieces of plastic, and then die or are eaten by other organisms.

In this study, the scientists used plastic beads of the type used in bottles, bags, textiles and hundreds of applications, ranging from four to six millimeters in diameter. After the microplastics had been in the ocean for about three weeks, dimethyl sulfide was found in the water and air around them in concentrations high enough that these types of birds may be able to smell, the scientists found, using tools that are otherwise meant for measuring sulfur in beer or wine.

The study suggests that the odor of dimethyl sulfide on or around marine plastic debris is “maladaptive foraging behavior” — that the birds are using their evolutionary traits to forage for food in ways that might be bad for them, causing problems like chemical toxicity or obstruction. According to the study, a recent projection model concluded that more than 99 percent of all seabird species will have eaten plastic debris by 2050.

Dr. Nevitt said that the study could have implications for other marine animals. Those that eat similar species to these birds — like baleen whales — or those that may also be attracted to dimethyl sulfide — like sea turtles — could be at risk. The researchers hope the study will help determine strategies for how to fight this growing environmental problem, as plastic pollution increases in the ocean.

http://advances.sciencemag.org/content/2/11/e1600395

Comment by Dr. Krishna Kumari Challa on November 11, 2016 at 7:40am

Why Neanderthal DNA wasn't much successful...

Neanderthals and modern humans got separated  from a common ancestor about half a million years ago.

Living in colder climes in Eurasia, Neanderthals evolved barrel chests, large skulls and strong hands. In Africa, modern humans acquired shorter faces, a prominent chin and slender limbs. Then, roughly 50,000 years ago, the two species encountered one another and interbred, as modern humans spread out of Africa.

The legacy of this interbreeding has been the subject of much scientific inquiry in the past few years. Today, up to 4 percent of the genes of non-Africans are Neanderthal in origin.. These may have influenced a diverse range of traits, including keratin production, disease risk. Where did all the other Neanderthal DNA go? Why did a Neanderthal-human hybrid not prevail?

Two recent studies converge on an explanation. They suggest the answer comes down to different population sizes between Neanderthals and modern humans, and this principle of population genetics: In small populations, natural selection is less effective.

Neanderthals have this small population over hundreds of thousands of years, presumably because they’re living in very rough conditions. As a result, Neanderthals were more inbred than modern humans and accumulated more mutations that have a slightly adverse effect, such as increasing one’s risk of disease, but do not prevent one from reproducing .

After Neanderthals started mating with humans, natural selection in the larger human population started excluding.

http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pg...

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