Month: December 2013

How brain balances learning new skills while retaining old ones

Researchers have developed a new computational model that explains how the brain maintains the balance between plasticity and stability, and how it can learn very similar tasks without interference between them.

To learn new motor skills, the brain must be plastic: able to rapidly change the strengths of connections between neurons, forming new patterns that accomplish a particular task. However, if the brain were too plastic, previously learned skills would be lost too easily.
The key, the neuroscientists at MIT said, is that neurons are constantly changing their connections with other neurons. However, not all of the changes are functionally relevant- they simply allow the brain to explore many possible ways to execute a certain skill, such as a new tennis stroke.

“Your brain is always trying to find the configurations that balance everything so you can do two tasks, or three tasks, or however many you’re learning. There are many ways to solve a task, and you’re exploring all the different ways,” lead author Robert Ajemian said.

As the brain learns a new motor skill, neurons form circuits that can produce the desired output- a command that will activate the body’s muscles to perform a task such as swinging a tennis racket. Perfection is usually not achieved on the first try, so feedback from each effort helps the brain to find better solutions.

This works well for learning one skill, but complications arise when the brain is trying to learn many different skills at once. Because the same distributed network controls related motor tasks, new modifications to existing patterns can interfere with previously learned skills.

That connectivity offers an advantage, however, because it allows the brain to test out so many possible solutions to achieve combinations of tasks. The constant changes in these connections, which the researchers call hyper plasticity, is balanced by another inherent trait of neurons- they have a very low signal to noise ratio, meaning that they receive about as much useless information as useful input from their neighbors.

The MIT team said noise is a critical element of the brain’s learning ability. They found that it allows the brain to explore many solutions, but it can only be utilized if the network is hyper plastic.

The study was published in the National Academy of Sciences

Source: news track india

Stressed parents make for obese kids

Researchers including an Indian-origin scientist have linked parental stress to weight gain in children.

The study found that children whose parents have high levels of stress have a Body Mass Index, or BMI, about 2 per cent higher than those whose parents have low levels of stress.

Children with higher parental stress also gained weight at a 7 per cent higher rate during the study period than other children.

Those figures may sound low, said lead author Dr. Ketan Shankardass, but they’re significant because they are happening in children, whose bodies and eating and exercise habits are still developing. Plus, if that weight gain continues and is compounded over a lifetime, it could lead to serious obesity and health issues.

Dr. Shankardass, a social epidemiologist with the hospital’s Centre for Research on Inner City Health, studied data collected during the Children’s Health Study, one of the largest and most comprehensive investigations into the long-term effects of air pollution on the respiratory health of children.

The childrens’ BMI was calculated each year. Their parents were given a questionnaire to measure their perceived psychological stress that asked how often in the last month they were able or unable to control important things in their life and whether things were going their way or their difficulties were piling up so high they could not overcome them.

Dr. Shankardass noted that more than half the students followed in the California study were Hispanic, and that the effects of stress on their BMI was greater than children of other ethnic backgrounds.

The research has been published in the journal Pediatric Obesity.

Source: top news

Brain cancer cure closer to reality

Scientists have identified a mechanism that can help treat brain cancer and a drug that decreases brain tumour growth.

The researchers at the University of Calgary’s Hotchkiss Brain Institute (HBI) have made a discovery that could lead to better treatment for patients suffering from brain cancer.

HBI member V. Wee Yong, PhD and research associate Susobhan Sarkar, PhD, and their team including researchers from the Department of Clinical Neurosciences and the university’s Southern Alberta Cancer Research Institute, looked at human brain tumour samples and discovered that specialized immune cells in brain tumour patients are compromised.

The researchers took this discovery and, in an animal model, identified a drug that is able to re-activate those immune cells and reduce brain tumour growth, thereby increasing the lifespan of mice two to three times.

Our brains normally contain specialized cells, called microglia, that defend against injury or infection. “Microglia are the brain’s own dedicated immune system,” explains Yong. “And in this study, we have formally demonstrated for the first time that these cells are compromised in living brain tumour patients.”

As with other forms of cancer, brain tumours start as individual stem-like cells – called brain tumour initiating cells (BTICs). These cells quickly divide and grow, eventually forming a mass, or tumour. Yong and his team have discovered that the tumour disables microglia, permitting the rapid proliferation of BTICs, which ultimately leads to brain tumour growth.

In addition to discovering this mechanism, Yong and Sarkar also identified a drug – amphotericin B (AmpB) – to reactivate microglia that in an animal model, showed a significant reduction in brain tumour growth.

The study was published in the journal Nature Neuroscience.

Source: Ani news

Corn oil better at cutting cholesterol than extra virgin olive oil

Researchers have shown that corn oil significantly lowers cholesterol with more favorable changes in total cholesterol (TC) and LDL-C than extra virgin olive oil.

The scientists were led by lead researcher, Dr. Kevin C Maki, PhD, of Biofortis, the clinical research arm of Merieux NutriSciences.

Among the 54 healthy men and women in the feeding study, consumption of foods made with corn oil resulted in significantly lower levels of LDL (bad) cholesterol and total cholesterol than the same foods made with extra virgin olive oil.

Corn oil lowered LDL cholesterol by 10.9 percent compared to extra virgin olive oil’s 3.5 percent reduction1,2, and total cholesterol decreased by 8.2 percent with corn oil compared to 1.8 percent for extra virgin olive oil. (Read: 8 natural cholesterol busters)

Study participants received four tablespoons of corn oil or extra virgin olive oil in the foods provided every day, consistent with the Dietary Guidelines for Americans recommendations. All foods were provided to the study participants as part of a weight maintenance diet.

The randomized, double-blind, controlled crossover clinical trial assessed the effects of dietary oils on fasting lipoprotein lipids.

The study compared the effects of corn and extra virgin olive oil on LDL cholesterol (primary outcome variable), total cholesterol, HDL cholesterol (good cholesterol), Non-HDL cholesterol

Source: health India

Four healthy reasons to eat seafood

Many researchers have shown that seafood, especially fatty fish, can be good for your overall health. It is a good source of omega-3 fatty acids, minerals and vitamins.

Healthy heart

Scientists have long ago noticed that the Inuits have low levels of heart disease since they depend mostly on seafood for sustenance and research over the years have proved this to be true. A recent research revealed that including one portion of seafood in your weekly diet may halve the chances of suffering a heart attack as more omega-3 help lower the amount of bad cholesterol and triglycerides in the blood.

Sharp brain

Oily fish also helps to support brain and nerve function thereby lowering the risk of developing dementia and Alzheimer’s disease.

Flexible joint

Fish oil is known to reduce inflammation and help prevent rheumatoid arthritis and other degenerative joint diseases.

Boost immunity

Seafood is packed with minerals like zinc, iodine and selenium. They help in the smooth running of the body, control growth and metabolism and help prevent diseases like cancer. Vitamins in seafood also help to keep the skin and eyesight healthy and help strengthen bones and teeth.

Source: Zee news

 

phone addicts are less likely to be happy: New study

  1. Those who can’t resist a ring are also more likely to suffer anxiety
  2.  Social network sites also listed as sources of stress

If you are constantly on your mobile phone, most onlookers might think you have lots of friends and a busy social life.

However, those attached to the phone are likely to be less happy than those who can resist a ring or a message alert, says a study.

Avid mobile phone users also suffer from higher anxiety while students see their class work suffer with lower marks than those who are able to switch off.

Researchers studied more than 500 students to look at their daily phone usage and gauge how it affected their outlook on life.

They found that far from making people feel more connected to friends the phone only heightened their anxiety as many felt obligated to keep in constant touch.

They found users suffered heightened anxiety as many felt obligated to keep in constant touch.

Others had trouble disconnecting from social media sites such as Facebook.

The study by scientists Jacob Barkley, Aryn Karpinski and Andrew Lepp is in stark contrast to previous research that found mobile phones improve social interaction and help reduce feelings of isolation.

Previous research has claimed that mobile phones improve social interaction and help reduce feelings of isolation.

But the latest study by Kent University in Ohio found constant phone use was linked to greater stress.

One student said: ‘The social network sometimes just makes me feel a little bit tied to my phone.

‘It makes me feel like I have another obligation in my life.’

Another complained that having a mobile phone meant that he could always be contacted at any time.

The researchers used a clinical measure of anxiety and each student’s level of satisfaction with their own life in the analysis.

Researcher Andrew Lepp added: ‘There is no me time or solitude left in some of these students’ lives and I think mental health requires a bit of personal alone time to reflect, look inward, process life’s events, and just recover from daily stressors.’

Those taking part, aged from 18 to 22, allowed the study team to access their exam results, known in the US as a grade point average (GPA), from university records.

‘Also, a few of the students we interviewed reported sending texts constantly throughout the day from morning to night that in itself might be stressful.’

There are now more mobile phones in the UK than people with the latest figures showing 80.2 million subscription.

The popularity in recent years of smart phones, such as the iPhone, has meant that 94 per cent of all adults own a mobile.

Source: mail online

 

Foods with Zinc can fight Diabetes Mellitus

Diabetes is an escalating issue in the United States, and there are no signs of this health ailment diminishing. According to the American Diabetes Association, 23.6 million adults and children have diabetes in the U.S. That is 7.8% of the population according to the latest data formed from 2007, and 1.6 million new cases are diagnosed each year. Luckily, there are many natural remedies that may aid in suppressing the negative effects of diabetes. Many of these remedies may completely cure or prevent diabetes when used properly.

Research shows that zinc, an essential trace element responsible for more than 300 enzyme functions, can aid in normalizing the negative effects of diabetes mellitus. According to the study, zinc has been shown to mitigate the harmful effects of diabetes by improving glycemic control in type I and type II diabetes. Many of the enzyme systems in which zinc is a necessity for are involved with the metabolism of blood sugar, and therefore make zinc a natural catalyst for insulin secretion.

The pancreas is an endocrine gland responsible for producing hormones like glucagon, somatostatin, and–you guessed it–insulin. The beta cells that secrete insulin in your pancreas are also highly stored with zinc. Without the high concentrations of zinc, the beta cells suffer. Luckily, beta cells are equipped with their own special transporter called ‘zinc transporter 80, which makes it easy for the beta cells to store the zinc. However, it is known that any metamorphosis of the genes in the zinc transporter 8 causes type 2 diabetes. It is also now known that antibodies against the zinc transporter are present in type 1 diabetic patients, which means that these antibodies are associated with type 1 diabetes.

It is no wonder why zinc is as popular as it is for supplementation. In addition to mending the difficulties brought on by diabetes, zinc also serves to maintain a healthy immune system, controls hair loss, halts impotence, improves brain function, prevents loss of taste or smell, and much more. Although supplementation is a viable option to obtain the amount of zinc that you need, it is not the only option thanks to the abundant amount of foods rich in zinc that are available to the general public. To reap the many benefits of zinc, one could include any of the following foods into their diet:

Wheat Germ
Sesame Flour and Tahini
Low Fat Roast Beef
Roasted Pumpkin and Squash Seeds
Dried Water Melon Seeds
Cocoa Powder and Chocolate
Peanuts
Almonds
Avocado
Bananas
Cashew
Cheese
Chickpeas (including hummus and falafel)
Crab, Dungeness
Cucumber
Fish
Kiwi Fruit
Lettuce
Lima Beans
Olives
Onion

Source: Information center

Dengue cases in New Delhi reach 5,462

The number of dengue cases in the capital has reached 5,462, a municipal health officer said Monday.

Though the number reported every week has reduced, the cases are still being witnessed in different parts of the city.

Most cases have been reported from the north zone (2,167), followed by south (1,642) and east (1,508) zones.

An additional 69 cases have been reported from the National Capital Region, including parts of Uttar Pradesh and Haryana.

Having surpassed the 2012 figure, the number of cases this year is nearing the 2010 figure (6,229).

Source: New Indian Express

Study shows air pollution more deadly than thought

The effect of long-term exposure to air pollution is associated with increased mortality even when the pollution is below European Union limits, shows new research.

The research was conducted by the Utrecht University. The researchers, led by Utrecht professor Rob Beelen, used data from the European Study of Cohorts for Air Pollution Effects (ESCAPE), which included data from 13 European countries and a total of 367,251 people, Xinhua reported Monday.

With each increase of 5 mg per cubic metre of particulate matter, the risk that someone dies increases by seven percent, the study showed.

“This is the difference between a busy street in the city, and a place without the influence of traffic,” Rob Beelen said.

The air quality norm in Europe is 25 mg per cubic metre, but the research showed the risks are still significant under 15 mg.

“Our findings show that there are significant health benefits to be gained when the concentrations of particulate matter will be further reduced,” Beelen added.

Particulate matter is the collective name for airborne particles that are so small that they penetrate deep into the lungs. The traffic is a major source, but factory plants and heating plants contribute to affect human health.

Source: xinhua

New technique identifies pathogens in patient samples faster, in great detail

A team of Danish investigators has shown how to identify pathogens faster, directly from clinical samples. The research appears in the Journal of Clinical Microbiology.
The investigators used a technique known as whole genome sequencing to identify and completely characterize bacteria causing urinary tract infections. In just 18 hours, they identified the culprit microorganisms, characterized the pathogens’ patterns of antibiotic susceptibility, and identified specific strains.

“Using conventional methodologies this would have taken several days to weeks, and even using whole genome sequencing on cultured bacteria would have taken an extra day,” says Frank M Aarestrup of the Technical University of Denmark, Lyngby, an author on the study.

According to the researchers, their work will help patients heal more quickly and avoid unnecessarily prolonged illness and even death. It will also help prevent outbreaks of hospital-acquired disease, and identify emerging infections.

“Rapid identification of the causative agent, and of any antibiotic resistance is crucial to choosing the correct treatment for individual patients,” says Aarestrup. “Choosing the wrong antibiotic will lead to longer infections and in the worst case, deaths.”

The investigators also identified bacteria in the patient samples that they did not detect using conventional techniques. “Lactobacillus iners, Gardnerella vaginalis, Prevotella, and A. urinae have all been implicated in [urinary tract infections], even though their precise roles as pathogens and normal colonizers of the genital tract have not been firmly established,” write the researchers. They note that by conventional methods A. urinae is rarely identified but frequently misclassified.

The ability to identify strains in patients with repeated infections enables the doctor to know whether the patient’s infection is new, or recurrent. And the typing of bacterial strains enables rapid comparison of bacteria from different patients, so that doctors can detect the spread of infections within the hospital, and identify emerging infections.

“Whole genome sequencing may still be too expensive for routine use in most clinical microbial laboratories,” the researchers write. But they predict that rapidly falling prices and automation will render it a standard technology for infection detection and control, in and out of the hospital.

Source: India Medical Times