Knowledge Update

​New York, Oct 4 (IANS) Do you know why some people are better at performing complex duties and multi-tasking? Because their brains are not static and the level of coordination between different parts of their brains seems to ebb and flow.

After analysing the brains of people at rest or carrying out complex tasks, researchers at Stanford University have learnt that the integration between those brain regions also fluctuates.

When the brain is more integrated, people do better on complex tasks.

"The brain is stunning in its complexity and I feel like, in a way, we've been able to describe some of its beauty in this story," said study lead author Mac Shine, post-doctoral researcher in the lab of Russell Poldrack, Professor of psychology.

"We've been able to say, 'Here's this underlying structure that you would never have guessed was there, that might help us explain the mystery of why the brain is organized in the way that it is,"" Shine added.

For the past 100 years, scientists have understood that different areas of the brain serve unique purposes. Only recently have they realised that the organisation isn't static.

In a three-part project, the researchers used open source data from the Human Connectome Project to examine how separate areas of the brain coordinate their activity over time - both while people are at rest and while they are attempting a challenging mental task.

They then tested a potential neurobiological mechanism to explain these findings.

For the resting state condition, the researchers used a novel analysis technique to examine functional magnetic resonance imaging (fMRI) data of people who weren't doing any particular task.

They found that even without any intentional stimulation, the brain network fluctuates between periods of higher and lower coordinated blood flow in the different areas of the brain.

The researchers found that the brains of participants were more integrated while working on complicated task than they were during quiet rest.

"This research shows really clear relationships between how the brain is functioning at a network level and how the person's actually performing on these psychological tasks," noted co-author Poldrack in a paper appeared in the journal Neuron.

The researchers plan to further investigate the connection between neural gain and integration in the brain.

They also want to figure out how universal these findings are to other behaviours, such as attention and memory.

This research may also eventually help us better understand cognitive disorders, such as Alzheimer's disease or Parkinson's disease.

​London, Oct 4 (IANS) Suffering from those itchy red pimples? Take heart, as your skin may age more slowly than those with no history of acne, a study has found.

Signs of ageing such as wrinkles and skin thinning often appear much later in people who have experienced acne in their lifetime. 

It has been suggested that this is due to increased oil production but there are likely to be other factors involved, the study said.

The findings revealed that people who have previously suffered from acne are likely to have longer telomeres in their white blood cells, meaning that their cells could be better protected against ageing.

Telomeres are repetitive nucleotide sequences found at the end of chromosomes, which protect them from deteriorating during the process of replication. 

The telomeres gradually break down and shrink as cells age, eventually leading to cell death, which is a normal part of human growth and ageing.

"Our findings suggest that the cause could be linked to the length of telomeres which appears to be different in acne sufferers and means their cells may be protected against ageing," said lead author Simone Ribero, a dermatologist at King's College London. 

Previous studies have shown that white blood cell telomere length can be predictive of biological ageing and is linked with telomere length in other cells in the body.

"For many years dermatologists have identified that the skin of acne sufferers appears to age more slowly than in those who have not experienced any acne in their lifetime. Whilst this has been observed in clinical settings, the cause of this was previously unclear," Ribero said.

'Longer telomeres are likely to be one factor explaining the protection against premature skin ageing in individuals who previously suffered from acne," added Veronique Bataille from King's College London. 

In the study the team measured the length of white blood cell telomeres in 1,205 twins. 

A quarter of the twins reported having experienced acne in their lifetime.

Statistical analyses which adjusted for age, relatedness, weight and height showed that telomere length in acne sufferers was significantly longer, meaning that white blood cells were more protected from the usual deterioration with age. 

The researchers also examined gene expression in pre-existing skin biopsies from the same twins to identify possible gene pathways linked to acne. 

One gene pathway (the p53 pathway), which regulates programmed cell death, was found to be less expressed in acne sufferers' skin. 

This requires further investigation to identify other genes involved in cell ageing and how they differ in acne sufferers, the researchers noted, in the paper published in the Journal of Investigative Dermatology.

Washington, Oct 4 (IANS) After collecting some key samples on the Red Planet for the past four years, NASA's Curiosity rover is driving toward uphill destinations as part of its two-year mission extension that commenced from October 1.

The destinations include a ridge capped with material rich in the iron-oxide mineral hematite, about two-and-half km ahead and an exposure of clay-rich bedrock beyond that.

These are key exploration sites on lower Mount Sharp where Curiosity is currently investigating evidence of ancient, water-rich environments that contrast with the harsh, dry conditions on the surface of Mars today.

"We continue to reach higher and younger layers on Mount Sharp. Even after four years of exploring near and on the mountain, it still has the potential to completely surprise us," said Indian-origin project scientist Ashwin Vasavada from NASA's Jet Propulsion Laboratory, Pasadena, California.

Curiosity has taken more than 180,000 images since landing on Mars in August 2012. 

Newly available vistas include the rover's latest self-portrait from the colour camera at the end of its arm and a scenic panorama from the colour camera at the top of the mast.

"Curiosity's assignment is the ongoing study of ancient habitability and the potential for life," said Curiosity Programme Scientist Michael Meyer from NASA.

This latest drill site -- the 14th for Curiosity -- is in a geological layer about 600 feet thick called the Murray formation. 

Curiosity has climbed nearly half of this formation's thickness so far and found it consists primarily of mudstone, formed from mud that accumulated at the bottom of ancient lakes. 

The findings indicate that the lake environment was enduring, not fleeting. 

For roughly the first half of the new two-year mission extension, the rover team anticipates investigating the upper half of the Murray formation.

"We will see whether that record of lakes continues further," Vasavada said. 

The "Hematite Unit" and "Clay Unit" above the Murray formation were identified from Mars orbiter observations before Curiosity's landing. 

"The Hematite and the Clay units likely indicate different environments from the conditions recorded in older rock beneath them and different from each other. It will be interesting to see whether either or both were habitable environments," added Vasavada.

The mission is also monitoring the modern environment of Mars, including natural radiation levels.

New York, Oct 4 (IANS) US researchers have identified 41 genes that may cause gum disease, paving the way for developing compounds that can be used in targeted treatment of severe periodontitis before loss of teeth and supportive bone occurs.

Periodontal disease is inflammation of the tissue around the teeth, often causing shrinkage of the gums and loosening of the teeth.

In the study, the team "reverse-engineered" the gene expression data to build a map of the genetic interactions that lead to periodontitis and identify individual genes that appear to have the most influence on the disease.

"Our approach narrows down the list of potentially interesting regulatory genes involved in periodontitis," said Panos N Papapanou, Professor at Columbia University Medical Center (CUMC) in New York.

"This allows us to focus on the handful of genes that represent the most important players in the process rather than the whole transcriptome," Papapanou added.

The researchers examined RNA from healthy and diseased gum tissues of 120 patients with periodontitis. 

Many of the genes identified by Papapanou and his team are implicated in immune and inflammatory pathways, confirming laboratory and clinical observations of the development of periodontal disease.

"Now it's important to do the downstream work of validating these master regulator genes in the lab before we can test these genes in experimental models," Papapanou noted in the paper published in the Journal of Dental Research.

Beijing, Oct 2 (IANS) China will have 240 million people aged 60 or above by 2020.

By 2020, senior citizens will make up 17 per cent of the population, Xinhua news agency on Sunday quoted Liu Qian, deputy head of the National Health and Family Planning Commission, as saying.

Liu said there were more than 260 million chronically ill patients in the country. These illnesses were to blame for over 86 per cent of deaths in China.

Liu said the per capita annual spending on health was estimated at around $472 last year.

​New York, Oct 2 (IANS) Using a food additive, a team of researchers has created environment-friendly plastic solar cells that can be manufactured at room temperature.

The efficient, semi-printed solar cells have implications for large-scale commercial production, said the researchers from North Carolina State University and the Chinese Academy of Sciences.

Two of the key advantages are that these cells can be mass produced in the open air environment and that the process doesn't pose health or environmental hazards, said Long Ye, post-doctoral research scholar in physics at NC State.

Ye and his colleagues developed a semi-printed plastic solar cell that utilised o-methylanisole (o-MA) as the solvent. 

O-MA is a commonly used flavouring agent in foods and is non-toxic to humans.

Plastic solar cells are popular because they are lightweight, flexible, transparent and inexpensive to manufacture. 

Unfortunately, the halogen-containing solvents used in their manufacture are an obstacle to large-scale commercialisation. 

These solvents are key to making sure that the solar cell's morphology, or structure, maximises its energy efficiency. However, they are environmentally hazardous. 

"Hopefully, this work can help pave the way for printing solar cells in ambient air (room temperature)," Ye added in a paper that appeared in the journal Chemistry of Materials.

​London, Oct 2 (IANS) Excessive sugar consumption -- specifically the sugar fructose such as in soda -- has been linked to a rise in metabolic disease worldwide, a study has found.

Some investigators contend that commonly consumed amounts of sugar do not contribute to this epidemic. While others are convinced that excessive sugar ingestion is a major cause.

"There is still significant controversy as to whether sugar consumption is a major contributor to the development of diabetes," said senior author Mark Herman, Assistant Professor at Duke University.

However, "the study reveals a specific mechanism by which consuming fructose in large amounts, such as in soda, can cause problems", Herman added.

Insulin is a key hormone that regulates blood glucose after eating. Insulin resistance, when the body's metabolic tissues stop responding normally to insulin, is one of the earliest detectable changes in the progression to diabetes.

The likely cause of insulin resistance may not be the build-up of fat in the liver, as commonly believed, but may be caused by excess sugar in the liver that activates a molecular factor known as carbohydrate-responsive element-binding protein, or ChREBP.

ChREBP may then contribute to the development of both fatty liver and increased glucose production, the researchers said.

The ChREBP protein is found in several metabolic organs in mice, humans and other mammals.

"We found that no matter how much insulin the pancreas made, it couldn't override the processes started by this protein, ChREBP, to stimulate glucose production. This would ultimately cause blood sugar and insulin levels to increase, which over time can lead to insulin resistance elsewhere in the body," Herman explained.

To test their hypothesis, researchers studied mice that were genetically altered so their liver insulin signalling pathways were maximally activated -- in other words, their livers should not have been able to produce any glucose.

The researchers found that even in these mice, eating fructose triggered ChREBP-related processes in the liver, causing it to make more and more glucose, despite insulin signals telling it to stop.

Previous studies have reported that high fructose diets can cause multiple metabolic problems in humans and animals, including insulin resistance and fatty liver disease.

The finding could also help scientists one day diagnose metabolic disorders earlier on, potentially allowing patients to make changes to their diets and lifestyles sooner to prevent more serious complications.

The study published in the Journal of Clinical Investigation.

Sydney, Oct 2 (IANS) Researchers have found three-dimensional prints of a 400 million year old fish fossil that can reveal the possible evolutionary origins of human teeth.

The printed fish fossil was found around Lake Burrinjuck in southeast Australia, by researchers from The Australian National University (ANU) and Queensland Museum in Australia.

The team digitally dissected the jaws of a fossil Buchanosteus -- an armoured fish from the extinct placoderm group -- and used the 3-D prints to learn how the jaws moved and whether the fish had teeth.

"We are conducting further research on the internal tissue structure of tooth-like denticles in the mouth of the fish fossil, to determine whether they represent a transitional stage in the evolution of teeth," said Gavin Young, palaeontologist at The Australian National University (ANU).

In the study, the team used high-resolution CT scan to investigate the internal structure of very fragile fossil skulls and braincases that have been acid-etched from limestone rock.

"It's great that we are able to use recent technology, such as micro-CT scanning and 3-D printing, to examine some of the earliest known evidence of tooth-like structures in the most primitive jawed fishes," noted Carole Burrow from Queensland Museum.

The study helped determine when and how teeth -- a characteristic feature of all animal species with jaws, including humans -- had originated in evolutionary history.

The results were published in the journal Biology Letters.

​London, Oct 2 (IANS) Family history and environment of the residential area are responsible for the differences between individual immune systems, a study has found.

The study published in the journal Trends in Immunology, discusses what shapes our immune system and how it might be applied.

The study has shown that air quality, food, stress levels, sleep patterns, and lifestyle choices had a strong combined effect on immune responses.

"Diversity isn't just programmed into our genes -- it emerges from how our genes respond to the environment," said Adrian Liston, researcher at the Translational Immunology Laboratory, Belgium.

Long-term infections are responsible for most of the differences between individual immune systems. 

These interactions slowly change the cellular makeup of immune system and make it more sensitive to that specific virus but also easier for other infections to slip past its defences. 

"People without these infections don't experience these cellular changes and even with the occasional cold or fever, their immune systems stay relatively stable over time. The exception is when a person is elderly," Liston added.

Researchers have shown that ageing changes how our immune system responds to threats. 

According to the study, as one gets older an organ called the thymus gradually stops producing T cells, which are made to help to fight off infection. Without new T cells, older people are more likely to get sick and less likely to respond to vaccines.

Beyond T cells, ageing also seems to broadly change the way our immune systems react. 

"A lot of diseases that we associated with ageing have an inflammatory component, which suggests there is likely immune involvement," said Michelle Linterman, researcher at the Babraham Institute, Britain.

"Understanding how the immune system changes with age is going to be hugely important for treating age-related diseases in the future," Linterman added. 

Washington, Oct 1 (IANS) Homeopathic teething tablets and gels may pose a health risk to infants and children, the US Food and Drug Administration (FDA) has warned.

Consumers should stop using these products and dispose of any in their possession, FDA recommended on Friday. 

Homeopathic teething tablets and gels are distributed by CVS, Hyland's, and possibly others, and are sold in retail stores and online, the US drug regulator said in a statement.

Following the FDA's warning, CVS announced a voluntary withdrawal of all brands of homeopathic teething products sold in its retail stores and online at CVS.com.

"Consumers should seek medical care immediately if their child experiences seizures, difficulty breathing, lethargy, excessive sleepiness, muscle weakness, skin flushing, constipation, difficulty urinating, or agitation after using homeopathic teething tablets or gels," FDA said.

"Teething can be managed without prescription or over-the-counter remedies," said Janet Woodcock, Director of the FDA's Center for Drug Evaluation and Research. 

"We recommend parents and caregivers not give homeopathic teething tablets and gels to children and seek advice from their health care professional for safe alternatives," Woodcock noted.

The FDA is analysing adverse events reported to the agency regarding homeopathic teething tablets and gels, including seizures in infants and children who were given these products, since a 2010 safety alert about homeopathic teething tablets. 

The FDA is currently investigating this issue, including testing product samples.