Knowledge Update

​London, July 1 (IANS) In hope for people suffering from dementia, accidents or traumatic events, a team of researchers has managed to erase unpleasant memories in mice using a "genetic switch."

The team from KU Leuven (Belgium) and the Leibniz Institute for Neurobiology (Germany) found that that some memories can also be erased when one particular gene is switched off.

The team trained mice that had been genetically modified in one single gene: neuroplastin.

This gene, which is investigated by only a few groups in the world, is very important for brain plasticity.

In humans, changes in the regulation of the neuroplastin gene have recently been linked to decreased intellectual abilities and schizophrenia.

“We were amazed to find that deactivating one single gene is enough to erase associative memories formed before or during the learning trials,” said Professor Detlef Balschun from the KU Leuven's laboratory for biological psychology.

“Switching off the neuroplastin gene has an impact on the behaviour of the mice, because it interferes with the communication between their brain cells,” he informed.

In the study, the mice were trained to move from one side of a box to the other as soon as a lamp lights up, thus avoiding a foot stimulus.

This learning process is called associative learning.

When the scientists switched off the neuroplastin gene after conditioning, the mice were no longer able to perform the task properly.

In other words, they showed learning and memory deficits that were specifically related to associative learning.

The control mice with the neuroplastin gene switched on, by contrast, could still do the task perfectly.

By measuring the electrical signals in the brain, the KU Leuven team discovered clear deficits in the cellular mechanism used to store memories.

These changes are even visible at the level of individual brain cells, as postdoctoral researcher Victor Sabanov was able to show.

"This is still basic research. We still need further research to show whether neuroplastin also plays a role in other forms of learning,” said Balschun adds in a paper published in the journal Biological Psychiatry.​

​Beijing, July 1 (IANS) Long-term exposure to air pollution, which has risen to alarming levels in the past years, is likely to cause damages to the kidneys, irrespective of age, warns a study.

The findings showed that air pollution increased the chances of developing membranous nephropathy -- an immune disorder of the kidneys -- that can lead to kidney failure.

Long-term exposure to high levels of particulate matter (PM 2.5) was associated with an increased risk of membranous nephropathy.

Previous studies have showed that increased exposure to air pollution may raise respiratory and cardiovascular diseases.

To examine how particulate matter in the air is affecting kidney health, a team analysed data on kidney biopsies taken over 11 years from 71,151 patients from 938 hospitals in 282 cities across China, encompassing all age groups.

The areas with high levels of fine particulate air pollution had the highest rates of membranous nephropathy.

On average, the likelihood of developing membranous nephropathy increased 13 per cent annually over the 11-year study period.

"Our primary finding is that the frequency of membranous nephropathy has doubled over the last decade in China. We show that the increase corresponds closely with the regional distribution of particulate air pollution," said lead author Fan Fan Hou of China's Southern Medical University.

The results, which appear in an upcoming issue of the Journal of the American Society of Nephrology (JASN), calls for attention on the role of air pollution in the development of kidney disease in urban areas, the researchers concluded.​

​New York, July 1 (IANS) Researchers have identified a protein that acts as a powerful protectant against free radicals -- a molecule that causes cell damage and death as well as ageing.

The findings showed that Lysosomes -- the protein that comprise the cell's recycling centre, are crucial for cleaning up injured and dying parts of the cells.

“Free radicals are guilty in the ageing process. If we have chemical compounds that can directly activate this channel, we can lower the oxidative stress in ageing and other diseases," said lead researcher Haoxing Xu, Associate Professor at University of Michigan, in the US.

Lysosomes were found to have a radical-sensing ability to know that the body has many free radicals.

Thus, when lysosomes "sense" an overload of free radicals, they activate a calcium channel on their membranes. 

This triggers the expression of many genes and the production of more and stronger lysosomes, which spurs into overdrive to get rid of the damaged parts of the cells.

"The result will be that cell damage and free radical levels could be reduced, and one can possibly slow down ageing," Xu added.

Ironically, the protein is activated by excessive free radicals. Human mutations of the gene for this protein are previously known to cause a rare, neurodegenerative disease, said the paper published in the journal Nature Communications.​

​Washington, June 30 (IANS) A new study has confirmed the link between eating canned food and increased exposure to a chemical linked to diabetes, cardiovascular disease and other health effects.

The study, by researchers at Stanford and Johns Hopkins universities, with a first-of-its-kind sample including thousands of people of various ages, and geographic and socioeconomic backgrounds, highlights the challenges consumers face in trying to limit their exposure to the chemical Bisphenol A (BPA), Xinhua news agency reported on Thursday.

Published in the recent issue of Environmental Research, the study of 7,669 participants, 6 years and older with 24-hour dietary recall information and urinary BPA concentrations from year 2003 through 2008 establishes the link that the more canned food consumed, the higher the BPA, confirming canned food's outsized influence on exposure to BPA.

"I could eat three cans of peaches, and you could eat one can of cream of mushroom soup and have a greater exposure to BPA," said lead author Jennifer Hartle, a postdoctoral researcher at the Stanford Prevention Research Centre.

According to the study, the consumption of one canned food to none was found to be associated with 24 per cent higher urinary BPA concentrations; and the consumption of two or more canned foods to none was associated with 54 per cent higher urinary BPA concentrations.

BPA is a compound used to make, among other things, resins that coat the inside of food cans and jar lids. Previous research has focused on analysing levels of BPA in canned products and measuring BPA exposure within groups of fewer than 75 people.

The new study also finds that different foods have different amounts of BPA contamination, and particular kinds of canned food are associated with higher urinary BPA concentrations. The worst offenders, in descending order: canned soup, canned pasta, canned vegetables and fruit.

The state of California has listed BPA as a female reproductive toxicant, and the US Food and Drug Administration (FDA) has restricted its use in some products, such as baby bottles, sippy cups and liquid infant formula canned linings. 

However, the FDA said the federal agency is still working to "answer key questions and clarify uncertainties about BPA".​

​London, June 30 (IANS) Researchers in Norway have identified a blood bio-marker that could indicate the long-term risk of developing cardiovascular diseases

The findings of the research at the Norwegian University of Science and Technology (NTNU) showed that the bio-marker -- called circulating microRNAs -- can predict ten-year risk for myocardial infarction -- a blockage of blood flow to the heart muscle.

"Our study showed that by measuring a combination of five different microRNAs and adding this information to the traditional risk factors for cardiovascular disease, we could identify those that were going to experience a myocardial infarction with considerably improved precision," said lead author Anja Bye, researcher at NTNU.

Regular analysis of blood for microRNAs, rather than just cholesterol and triglycerides, can provide 77.6 per cent accurate results of the risk of heart disease, the researchers noted.

Traditionally, it was risk factors such as body mass index (BMI), blood pressure, smoking and dietary habits that have indicated the health of the heart.

Though these did provide a degree of accuracy, results still overlooked 15-20 per cent of myocardial infarction patients who were on the “low risk” list based on lifestyle factors.

For the study, published in the Journal of Molecular and Cellular Cardiology, the team looked at 212 healthy participants aged between 40-70 years that either died from myocardial infarction within ten years or remained healthy at the time of the final study in 2006.​

​Washington, June 30 (IANS) Researchers have developed a unique, multifunctional smart material that can change shape from heat or light and and also heal its scratches.

Smart materials that can react to external stimuli, like light or heat, have been an interesting novelty and look almost magical as they mysteriously fold and unfold themselves. 

They have a variety of potential applications, such as for actuators, drug delivery systems and self-assembling devices. For instance, smart materials could change shape to unfold a solar panel on a space satellite without need of a battery-powered mechanical device.

But smart materials haven't come into widespread use because they are difficult to make and often can only perform one function at a time. 

The Washington State University research team developed a material that allows multiple functions at once with the potential to add more.

A paper describing the material was published in Applied Materials & Interfaces, a journal of the American Chemical society.

The team worked with a class of long-chain molecules, called liquid crystalline networks (LCNs), which provide order in one direction and give material unique properties. 

The researchers took advantage of the way the material changes in response to heat to induce a unique three-way shape shifting behaviour. 

They added groups of atoms that react to polarised light and used dynamic chemical bonds to improve the material's reprocessing abilities.

"We knew these different technologies worked independently and tried to combine them in a way that would be compatible,'' said one of the lead researchers Michael Kessler, Professor at Washington State University.

The resulting material reacts to light, can remember its shape as it folds and unfolds and can heal itself when damaged. 

For instance, a razor blade scratch on the material can be fixed by applying ultraviolet light.

The material's movements can be pre-programmed and its properties tailored, the researchers said.​

​London, June 30 (IANS) The universe is becoming gradually cleaner as more and more cosmic dust is being mopped up by the formation of stars within galaxies, an international team of astronomers has revealed.

Peering back 12 billion years using the Herschel space telescope to produce far-infrared images of the sky, the team led by researchers at Cardiff University was able to observe the very early formation of galaxies and compare them to galaxies that have formed much more recently.

"Our results show that the reason for this evolution is that galaxies used to contain more dust and gas in the past, and the universe is gradually becoming cleaner as the dust is used up," said co-leader of the project Steve Eales, Professor at Cardiff University's School of Physics and Astronomy.

The findings were presented at the National Astronomy Meeting in Nottingham, Britain. 

Cosmic dust is comprised of tiny solid particles that are found everywhere in space between the stars. The dust and the gas in the universe is the raw material out of which stars and galaxies form.

Though this blanket of material is key to the formation of stars and galaxies, it also acts as a sponge, absorbing almost half of the light emitted by stellar objects and making them impossible to observe with standard optical telescopes.

The Herschel space telescope was launched in 2009 to provide researchers better tool for probing this hidden universe.​

​London, June 30 (IANS) Sleeping more or less than the average seven hours may increase the risk of developing diabetes in men, a new study warns.

The findings showed that men who slept the least and the most were more likely to have an impaired ability to process sugar compared to men who slept an average amount of about seven hours.

The men at either end of the spectrum had higher blood sugar levels than men who got the average amount of sleep.

Conversely, women who slept less or more than average were more responsive to the hormone insulin than women who slept the average amount.

They also had enhanced function of beta cells - the cells in the pancreas that produce the hormone insulin.

This suggests lost sleep may not put women at increased risk of developing diabetes, the study said.

"In men, sleeping too much or too little was related to less responsiveness of the cells in the body to insulin, reducing glucose uptake and thus increasing the risk of developing diabetes in the future," said Femke Rutters from VU University in the Netherlands.

During the last 50 years, the average self-reported sleep duration for individuals has decreased by 1.5 to two hours.

The prevalence of diabetes has doubled in the same time period, the researchers noted.

"Even when you are healthy, sleeping too much or too little can have detrimental effects on your health," Rutters said adding, "this research shows how important sleep is to a key aspect of health - glucose metabolism."

The study, published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism, is the first to show opposite effects of lost sleep on diabetes risk in men and women.

In the cross-sectional study, the team examined the sleep duration and diabetes risk factors in 788 healthy adults ranging in age from 30 to 60 years old.

The researchers observed sex-specific relationships between sleep duration and glucose metabolism in the participants.​

​New York, June 30 (IANS) Facebook has made changes in news feed ranking to ensure you do not miss updates from families and friends amid the flood of information on the social media platform of over a billion users.

"The goal of News Feed is to show people the stories that are most relevant to them. Today, we’re announcing an update to News Feed that helps you see more posts from your friends and family,” Facebook executive Adam Mosseri wrote on a blogpost on Wednesday.

The new changes mean that wedding photographs of your close friend would get more prominence than the stories linked to what happened in Turkey or for that matter in India.

"When we launched News Feed in 2006, it was hard to imagine the challenge we now face: far too much information for any one person to consume,” Mosseri said.

"In the decade since, more than a billion people have joined Facebook, and today they share a flood of stories every day. That’s why stories in News Feed are ranked ? so that people can see what they care about first, and don’t miss important stuff from their friends,” Mosseri explained.

"If the ranking is off, people don’t engage, and leave dissatisfied. So one of our most important jobs is getting this ranking right,” the post said.

The social networking giant recently faced allegations of political bias in the selection or prominence of stories in its "Trending Topics" feature. An internal investigation of the organisation, however, revealed no evidence of any systematic political bias.

"Facebook was built on the idea of connecting people with their friends and family. That is still the driving principle of News Feed today,” Mosseri said.

"We are not in the business of picking which issues the world should read about. We are in the business of connecting people and ideas ? and matching people with the stories they find most meaningful,” Mosseri pointed out.​

​New York, June 29 (IANS) Adolescents living in neighbourhoods with more greenery may exhibit less aggressive behaviour, finds a new study.

The findings showed that increasing greenery levels like parks, golf courses or fields, might lead to a 12 per cent decrease in clinical cases of aggressive behaviour. 

"Our study provides new evidence that increasing neighbourhood greenery may be an effective alternative intervention strategy for an environmental public health approach that has not been considered yet," said Diana Younan, doctoral student, at the University of California in the US. 

Nine to 18-year-olds who lived in places with more greenery had significantly less aggressive behaviour than those living in neighbourhoods with less greenery. 

Both short-term (one to six months) and long-term (one to three years) exposure to green spaces within 1,000 metres of residences were associated with reduced aggressive behaviour. 

The behavioural benefit of green spaces equated to approximately two to two-and-a-half years of adolescent maturation.

In addition, these benefits existed for both boys and girls of all ages and races/ethnicities, and across populations with different socio-economic backgrounds and living in communities with different neighbourhood quality.

"It is important that we target aggressive behaviours early. Identifying effective measures to reduce aggressive and violent behaviours in adolescents is a pressing issue facing societies worldwide," Younan added.

Factors such as age, gender, race/ethnicity, socio-economic status, parents' educational background, occupation, income level, or marital status and whether their mother smoked while pregnant or was depressed did not affect the findings.

For the study, the team followed 1,287 adolescents from Southern California who were aged nine to 18 years to see whether greenery surrounding the home could reduce aggressive behaviour.

The results will be published in the forthcoming issue of the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP). ​