Knowledge Update

New York, Sep 21 (IANS) Exposure to certain common chemicals called endocrine-disrupting chemicals found in several consumer products, including plastic bottles, may reduce levels of vitamin D in the bloodstream, says a study.

Endocrine-disrupting chemicals (EDC) are found in everyday products and throughout the environment. Bisphenol A (BPA), a known EDC, is often found in plastics and other consumer products. 

"Nearly every person on the planet is exposed to BPA and another class of endocrine-disrupting chemicals called phthalates, so the possibility that these chemicals may even slightly reduce vitamin D levels has widespread implications for public health," said the study's first author Lauren Johns from the University of Michigan School of Public Health in Ann Arbor.

EDCs are chemicals or mixtures of chemicals that can cause adverse health effects by interfering with hormones in the body. 

"Vitamin D plays a broad role in maintaining bone and muscle health. In addition, low vitamin D levels have been implicated in outcomes of numerous conditions such as cardiovascular disease, diabetes and cancer," Johns said.

The study examined data from 4,667 US adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2010. 

The participants provided blood samples so their vitamin D levels could be measured. To measure EDC exposure, the participants had their urine analysed for substances left behind after the body metabolised phthalates and BPA.

The study, published in the Journal of Clinical Endocrinology & Metabolism, found people who were exposed to larger amounts of phthalates were more likely to have low levels of vitamin D in the bloodstream than the participants who were exposed to smaller amounts of the EDCs. 

The link was strongest in women. There also was an association between exposure to higher levels of BPA and reduced vitamin D levels in women, although the relationship was not statistically significant in men.

"More research is needed into why an association exists, but it is possible that EDCs alter the active form of vitamin D in the body through some of the same mechanisms that they use to impact similar reproductive and thyroid hormones," senior author of the study John Meeker, Professor at the University of Michigan, explained.

​New York, Sep 19 (IANS) Refuting claims that it is updating the astrological signs, NASA has said that it did not do it as the space agency studies astronomy not astrology.

"We did not change any Zodiac signs, we just did the math. The Space Place (an educational page for kids run by NASA) article was about how astrology is not astronomy, how it was a relic of ancient history and pointed out the science and math that did come from observations of the night sky," NASA spokesperson Dwayne Brown told Gizmodo.

Last week a news spread that 86 per cent of the people now have a different star sign as NASA had decided to update the astrological signs for the first time in 2,000 years. 

In NASA's educational page for children called Space Place, the agency discussed how, some 3,000 years ago, the ancient Babylonians were keen sky-watchers and thought that the changing positions of constellations throughout the year could be linked to certain behaviours or events on Earth.

As a result of this, those sky-watchers invented the zodiac.

"So, as Earth orbits the Sun, the Sun would appear to pass through each of the 12 parts of the zodiac. Since the Babylonians already had a 12-month calendar (based on the phases of the Moon), each month got a slice of the zodiac all to itself," Science Alert reported on Monday citing the article in Space Place. 

But seeing as this happened 3,000 years ago, things were a bit arbitrary, and for whatever reason, the Babylonians left a constellation out of their zodiac -- Ophiuchus, the report said. 

"Even then, some of the chosen 12 did not fit neatly into their assigned slice of the pie and slopped over into the next one," Space Place noted, adding, "To make a tidy match with their 12-month calendar, the Babylonians ignored the fact that the Sun actually moves through 13 constellations, not 12."

NASA said that due to a tiny wobble in the Earth's axis, the position of those constellations has shifted. This means that those constellations are no longer in the same spots today as they were when the ancient Babylonians were looking up.

But that has nothing to do with change of zodiac signs.

​London, Sep 19 (IANS) Individuals with autism spectrum disorder (ASD) are either over- or under-sensitive to sensory information.

The severity of social difficulties experienced by them daily may increase according to their senstitiveness to touch, which may be more than their visual or auditory sensitivities, a study has found.

The study showed that the sense of touch may play a more crucial role in individuals with ASD than previously assumed. 

For some with ASD, busy and crowded environments such as supermarkets are overwhelming, while others may be less sensitive to pain, or dislike being touched.

They may have difficulties in determining which tactile sensations belong to the action of someone else, the study said.

"The results can yield a novel and crucial link between sensory and social difficulties within the autism spectrum," said Eliane Deschrijver from Ghent University in Belgium.

A normal human brain can detect very quickly when a touch is not their own. However, this process is different in the brain of adults with ASD. 

Their brain may signal to a much lesser extent, when an external touch sensation does not correspond to their own touch.

Individuals who experienced stronger sensory difficulties showed a stronger disturbance in their brain. They were also the ones that experienced more severe social difficulties, the researchers said.

"It is the first time that a relationship could be identified between the way individuals with ASD process tactile information in their brain, and their daily social difficulties," Deschrijver noted.

"These findings can primarily lead to a better understanding of the complex disorder, and of associated difficulties," added Roeljan Wiersema, Professor at Ghent University in Belgium.

In the study, the researchers investigated how the brain of individuals with and without ASD uses own touch to understand touch sensations in the actions of others.

In a series of experiments with electro-encephalography (EEG), the scientists showed that the brain activity of adults with ASD differs from that of adults without ASD while processing touch.

The findings were published online in the journal Social, Cognitive and Affective Neuroscience.

New York, Sep 19 (IANS) Larger-bodied marine animals are more likely to become extinct than smaller creatures, and humans are to be largely blamed for this, say researchers.

It is a pattern that is unprecedented in the history of life on Earth, and one that is likely driven by human fishing, said the study published in the journal Science.

"We've found that extinction threat in the modern oceans is very strongly associated with larger body size," said Jonathan Payne, a paleobiologist at Stanford University's School of Earth, Energy & Environmental Sciences.

"This is most likely due to people targeting larger species for consumption first," Payne noted.

For the study, the researchers put modern extinction in context by comparing them with Earth's five previous mass extinctions.

"We used the fossil record to show, in a concrete, convincing way, that what is happening in the modern oceans is really different from what has happened in the past," study co-author Noel Heim, a postdoctoral researcher in Payne's lab, said. 

Specifically, the authors found that the modern era is unique in the extent to which creatures with larger body sizes are being preferentially targeted for extinction. 

"What our analysis shows is that for every factor of 10 increase in body mass, the odds of being threatened by extinction go up by a factor of 13 or so," Payne said. 

"The bigger you are, the more likely you are to be facing extinction," Payne noted.

The selective extinction of large-bodied animals could have serious consequences for the health of marine ecosystems, the scientists say, because they tend to be at the tops of food webs and their movements through the water column and the seafloor help cycle nutrients through the oceans, the scientists said.

​New York, Sep 20 (IANS) Some mosquitoes are more likely to feed on cattle than on humans if they carry a specific chromosomal rearrangement in their genes, thus reducing their odds of transmitting the malaria parasite, a new study has found.

The parasite causing the disease is carried by Anopheles mosquitoes species that transmit it to humans by biting them. One of these species is Anopheles arabiensis, which is the primary vector of malaria in East African countries.

Rates of malaria transmission depends on whether mosquitoes bite humans. When mosquitoes bite cattle, malaria does not spread because these animals are dead-end hosts.

The transmission also depends whether mosquitoes rest after their meals in areas where they are likely to encounter pesticides, the study said.

Using a population genomics approach, the study established an association between human feeding and a specific chromosomal rearrangement in the major east African malaria vector.

"Whether there is a genetic basis to feeding preferences in mosquitoes has long been debated. This work paves the way for identifying specific genes that affect this critically important trait," said Bradley Main, researcher at the University of California - Davis, in the US.

In the study, the team sequenced the genomes of 23 human-fed and 25 cattle-fed mosquitoes collected indoors and outdoors from the Kilobero Valley in Tanzania.

An analysis of these genomes allowed them to identify a chromosomal rearrangement -- known as the 3Ra inversion -- associated with cattle feeding.

It however did not appear to have an impact on the mosquitoes' resting behaviours.

Using genetics to better understand and track mosquito behaviour can improve local control strategies.

This knowledge may also open novel avenues for stopping malaria's spread, such as genetically modifying mosquitoes to prefer cattle over people, the researchers noted, in the paper published in the journal PLOS Genetics.

New York, Sep 20 (IANS) Our visual experiences are not be linked to our understanding of numbers, a study, led by an Indian-origin researcher, of people born blind has revealed.

The study showed that the visual cortex -- the part of the brain that receives and processes sensory nerve impulses from the eyes -- in blind people is highly involved in numerical reasoning, suggesting that the brain is vastly more adaptable than previously believed. 

"The number network in brain develops totally independently of visual experience. Blind people have never seen anything in their lives, but they have the same number network as people who can see," said lead author Shipra Kanjlia, a graduate student at Johns Hopkins University in Maryland, US. 

Further, the visual cortex -- also known as the visual area -- involved in doing maths is similar in both blind as well as sighted people, the study said. 

This visual cortex is extremely plastic and, when it isn't processing sight, can respond to everything from spoken language to math problems.

"The brain as a whole could be extremely adaptable, almost like a computer that -- depending on data coming in -- could reconfigure to handle almost limitless types of tasks," explained another researcher Marina Bedny, assistant professor at Johns Hopkins University.

It could someday be possible to re-route functions from a damaged area to a new spot in the brain, she said. "If we can make the visual cortex do math, then we can make any part of the brain do anything," Bedny stated.

For the study, the team involved congenitally blind people and sighted people wearing blindfolds to solve math equations and answer language questions while having a brain scan. 

With the math problems, participants heard pairs of increasingly complicated recorded equations and responded if the value for "x" was the same or different. 

The participants also heard pairs of sentences and responded if the meaning of the sentences was the same or different.

With both blind and sighted participants, the key brain network involved in numerical reasoning, the intraparietal sulcus, responded robustly as participants considered the math problems.

Meanwhile, in blind participants only, regions of the visual cortex also responded as they did math. And the visual cortex did not merely respond, the more complicated the math, the greater the activity was in the vision centre.

In addition, the study demonstrated that this re-purposed vision centre in blind people was not just responding to new functions haphazardly. But, the region has become specialised and segmented by function, like any other part of the brain. 

While some parts of the cortex are doing math, other parts are doing language, etc. 

Even in a resting state, brain scans show these new brain regions connect to traditional parts of the brain responsible for math and language in sighted people, the researchers concluded.

The findings were published online in the journal Proceedings of the National Academy of Sciences.

London, Sep 20 (IANS) Researchers, including one of Indian-origin, have found that people with epilepsy are at significantly higher risk of experiencing discrimination due to health problems than the general population.

This risk is greater for them than those with other chronic health problems such as diabetes, asthma and migraines.

People with epilepsy also had a greater likelihood of experiencing domestic violence and sexual abuse than the general population, according to the study published in the journal Epilepsia.

The analysis also found that such psychosocial adversities could help explain why individuals with epilepsy are at an increased risk of developing depression and anxiety disorders.

"We still don't know enough about why people with epilepsy develop depression and anxiety disorders much more often than the general population. Our findings suggest that adverse life events such as discrimination may be important," said senior author Dheeraj Rai from University of Bristol in Britain.

For the study, the researchers used data from the the Adult Psychiatric Morbidity Survey 2007 that included comprehensive interviews with 7,403 individuals living in private residences in England. 

Doctor-diagnosed epilepsy and other chronic conditions were established by self-report.

Discrimination, domestic violence, physical and sexual abuse, and other stressful life events were assessed using computerised self-completion and a face-to-face interview, respectively.

The researchers found that people with epilepsy were sevenfold more likely to have reported experiencing discrimination due to health problems than the general population without epilepsy. 

"This paper demonstrates that despite all of the advances made over the last 100 years, the experience of discrimination continues to be a significant problem for people with epilepsy," first author of the study Victoria Nimmo-Smith from University of Bristol said.

London, Sep 16 (IANS) Envy is the most common basic personality trait shaping human behaviour -- and is found among almost one-third of the human population, an interesting study has found.

The study on human behaviour found that 90 per cent of the human population can be divided into four main basic personality traits -- optimistic, pessimistic, trusting and envious. 

In the study, the researchers from Universidad de Zaragoza in Spain analysed the responses of 541 volunteers to hundreds of social dilemmas.

Participants were put into pairs and given options that either led to collaboration or conflict with others. 

Based on the results, the researchers developed a computer programme to classify people according to their behaviour.

The largest proportion of people (30 per cent) turned out to be "envious". They did not mind what they achieved as long as they were better than everyone else.

While the optimists (20 per cent) believed that they and their partner will make the best choice for both of them, the pessimists (20 per cent) selected options which they saw as the lesser of two evils.

The trusting group (20 per cent) were born collaborators who always cooperated and did not mind if they win or lose.

There is a fifth, undefined group, representing 10 per cent, which the algorithm is unable to classify in relation to a clear type of behaviour, the researchers said. 

The researchers argue that this allows them to infer the existence of a wide range of subgroups made up of individuals who do not respond in a determined way to any of the outlined models. 

"The results go against theories which states that humans act purely rationally for example, and, therefore, they should be taken into consideration in redesigning social and economic policies, as well as those involved in cooperation," said Yamir Moreno from the Universidad de Zaragoza. 

"These types of studies are important because they improve existing theories on human behaviour by giving them an experimental base," Moreno concluded in the study published in the journal Science Advances. 

New York, Sep 17 (IANS) A team of researchers has discovered a new mechanism for a bacterial toxin to inhibit inflammation in a commonly inherited autoinflammatory disease.

Familial Mediterranean fever (FMF), also known as Armenian disease, is a hereditary inflammatory disorder caused by mutations in MEFV -- a gene that leads to continuous activation of a protein called pyrin -- causing problems in regulating inflammation in the body. 

The study showed that a toxin in Yersinia pestis, which is the bacterial agent of plague, targets and inhibits the protein pyrin. 

"This finding is very significant because it may explain the natural selection process behind a chronic condition that affects a high prevalence of people originating around the Mediterranean Sea," said lead author James Bliska, Professor at the Stony Brook University in New York, US. 

Thousands of individuals from many ethnic origins of the Mediterranean, such as Armenians, Italians, Greeks and Arabs have FMF, the study said.

In addition, the bacterial toxin hijacks human kinases to phosphorylate and inhibits pyrin, a process that could be translated into therapeutics for FMF, Bliska added.

The hereditary inflammatory disease of FMF usually strikes individuals at some point in childhood and continues throughout adulthood. 

They occur in bouts called attacks that last one to three days. Arthritic attacks may last for weeks or months.

Fever, abdominal pain, chest pain, achy, swollen joints, constipation followed by diarrhea, a red rash on legs, especially below the knees, muscle aches, a swollen, tender scrotum, include the signs and symptoms of FMF.

There are treatments but no cures, and complications such as arthritis and vasculitis can occur after many prolonged inflammatory episodes. 

The findings, published in Cell Host & Microbe, can be used to better understand the genetic origins of FMF and explore new therapies for the disease.