Moderate alcohol consumption may change the structure of the heart in ways that increases the risk of atrial fibrillation leading to a stroke, a study suggests.

Atrial fibrillation is a known risk factor for stroke and the irregular pumping of blood can lead to clots, which may travel to the brain and cause a stroke.

"There is growing evidence that moderate alcohol intake may be a risk factor for atrial fibrillation, the most common heart rhythm disturbance in the world, but the mechanism by which alcohol may lead to atrial fibrillation is unknown," said Gregory Marcus, researcher at the University of California, San Francisco.

Marcus and his colleagues in the study published in the Journal of the American Heart Association looked at damage to the left atrium of the heart as a possible pathway between alcohol and atrial fibrillation.

The researchers evaluated data from more than 5,000 adults collected over several years including echocardiograms, medical history and self-reported alcohol intake.

The study participants who are in their 40s to 60s, reported on average just over one drink per day. The overall rate of atrial fibrillation in the group was 8.4 cases per 1,000 persons per year -- meaning over a 10-year period, eight out of 100 persons were likely to develop atrial fibrillation.

Every additional drink per day was associated with 0.16 millimetre enlargement of the left atrium, highlighting a possible site of physical damage caused by drinking.

The new findings also shed light on the complex relationship between alcohol and heart health.

Research has shown that moderate drinking can reduce the risk of heart attack while increasing the risk of atrial fibrillation.

Marcus's team captured this theory and found that patients in counties permitting alcohol sales were more likely to have atrial fibrillation but less likely to have heart attacks and congestive heart failure.

"Alcohol's abilities to protect and harm the heart likely operate through different mechanisms and vary from person to person," Marcus added.

A new study finds that fish oil helps to boosts brain functions and also improves mood as it contains Omega-3 fatty acids.

Fish oil helps athletes and soldiers to manage intense training better.

The finding suggests that low concentration of fish oil in the blood and also lack of physical activity may contribute to the high levels of depressed mood among soldiers returning from combat.

Fish oil content is especially important for soldiers due to the consistent training and physical regiments performed in and out of combat and risk of traumatic brain injury.

Researchers worked with 100 soldiers to identify which factors affected the moods of those returning from combat for the study.

The study was published in the journal Military Medicine.

"We looked at how physical activity levels and performance measures were related to mood state and resiliency. What we found was the decrease in physical activity and the concentration of fish oil and Omega-3s in the blood were all associated with resiliency and mood," said Richard Kreider, Researcher at the Texas A and M University.

The study originated from research that examined Omega-3 fatty acid levels of soldiers who committed suicide compared to non-suicide control and found lower Omega-3 levels in the blood were associated with increased risk of being in the suicide group.

According to the researchers, these findings are significant toward addressing some of the issues many soldiers face.

"The mental health of soldiers is a serious concern and it is exciting to consider that appropriate diet and exercise might have a direct impact on improving resiliency," said Nicholas Barringer, Researcher at the Texas A and M University.

In order to properly measure soldiers physically, Kreider and Barringer developed a formula that has the potential to assist in effectively screening soldiers with potential post-traumatic stress disorder (PTSD) ahead of time.

The formula measures a number of factors including fitness and psychometric assessments, physical activity and additional analysis.

"By improving resiliency in service members, we can potentially decrease the risk of mental health issues. Early identification can potentially decrease the risk of negative outcomes for our active service members as well as our separated and retired military veterans," Barringer added.

"The military is using some of our exercise, nutrition, and performance-related work and the findings may help identify soldiers at risk for depression when they return from combat tours," Kreider added.

The study mentioned that by working to identify such high-risk issues faced by soldiers, it can set a precedent that will benefit not only the military leadership, but also the general public.

Old age may slow down memory and other physical and cognitive skills, but the brain has the remarkable potential to reduce these effects, a study has found.

In order to process the information that we receive every day, our brain builds categories into which we sort everything that makes up the world around us.

The study found that this process of categorisation changes as we age. The brains of elderly struggle to categorise and rapidly switch focus from one to another.

"Older people find it harder to switch from one strategy to the other," said Sabrina Schenk, neuroscientist at Ruhr-Universitat Bochum (RUB) in Germany.

But, their brains compensate by paying more attention to detail than younger adults, the study said.

While the young adults spread their attention wide and gather information from different sources, the elderly focus their attention, looking more at detail, the researchers explained.

"To a certain extent, the brain is able to slow down negative effects of ageing by increasing its level of attentiveness," Schenk added.

In the study, the participants were asked to sort circles with varying colour combinations into one of two categories.

Some of the circles were very similar to each other; others were distinctly different. To which category the circles belonged was indicated by a feedback during the test.

The researchers not only documented the participants' answers, they also recorded their brain waves via an electroencephalogram (EEG) and used an eye tracker to trace their line of vision.

The results showed that both young and older participants had no difficulties categorising the similar looking circles -- the learning mechanism of both groups were comparable.

It was only in the later stages of the experiment, when distinct looking circles where shown, that differences between the groups became apparent.

Older participants found it more difficult to categorise these exceptions than their younger counterparts.

The measurements of brain waves also showed that the elderly develop a particular selective attentiveness.

In other words, they pay more attention to details and look more closely than younger people. This was also confirmed by the eye tracker, the researchers concluded in the paper published in the journal Neuropsychologia.

Neuroscientists have identified two brain regions that are involved in creating panoramic memories and help us to merge fleeting views of our surroundings into a seamless, 360-degree panorama.

As we look at a scene, visual information flows from our retinas into the brain, which has regions that are responsible for processing different elements of what we see, such as faces or objects.

"Our understanding of our environment is largely shaped by our memory for what's currently out of sight," said lead author Caroline Robertson, post doctoral student at the Massachusetts Institute of Technology (MIT) in the US.

The study found the hubs in the brain where your memories for the panoramic environment are integrated with your current field of view.

The researchers suspected that areas involved in processing scenes -- the occipital place area (OPA), the retrosplenial complex (RSC), and parahippocampal place area (PPA) -- might also be involved in generating panoramic memories of a place such as a street corner.

Brain scans conducted on study participants revealed that when participants saw two images that they knew were linked, the response patterns in the RSC and OPA regions were similar.

However, this was not the case for image pairs that the participants had not seen as linked.

This suggests that the RSC and OPA, but not the PPA, are involved in building panoramic memories of our surroundings, the researchers said.

"Our hypothesis was that as we begin to build memory of the environment around us, there would be certain regions of the brain where the representation of a single image would start to overlap with representations of other views from the same scene," Robertson added.

For the study, the team used immersive virtual reality headsets, which allowed them to show people many different panoramic scenes, the researchers showed participants images from 40 street corners in Boston's Beacon Hill neighbourhood.

The images were presented in two ways. Half the time, participants saw a 100-degree stretch of a 360-degree scene, but the other half of the time, they saw two noncontinuous stretches of a 360-degree scene.

After showing participants these panoramic environments, the researchers then showed them 40 pairs of images and asked if they came from the same street corner.

Participants were much better able to determine if pairs came from the same corner if they had seen the two scenes linked in the 100-degree image than if they had seen them unlinked, said the paper appearing in the journal Current Biology.

A new influenza virus that affects cattle has an official name -- influenza D, as proposed by South Dakota State University researchers -- including one of Indian origin -- who discovered it.

The executive committee of the International Committee of Taxonomy of Viruses approved naming the new virus influenza D, Professor Feng Li said in a university statement on Thursday.

It was named Influenza D virus because of its distinctness from other influenza types -- A, B and C.

Though South Dakota State University alumnus Ben Hause isolated the virus from a diseased pig in 2011, he later found that cattle were the primary reservoir for influenza D.

Hause identified and characterised the new virus as part of his doctoral research under Li's tutelage.

This is the first influenza virus identified in cattle, Li explained.

Li and Professor Radhey Shyam Kaushik secured a US National Institutes of Health grant for nearly $400,000 to study the biology, genetics and evolution of the new virus.

Ultimately, the goal is to determine whether influenza D, which has 50 per cent similarity to human influenza C, can cause problems in humans, according to Kaushik.

However, he noted, "the virus has not been shown to be pathogenic in humans. No one should be afraid of this".

The research group showed that influenza D is spread only through direct contact and proved a guinea pig can be used as an animal model to study the virus.

Influenza D antibodies have been identified in blood samples from sheep and goats, but the virus does not affect poultry.

Studies are underway to compare the virulence among the bovine and swine influenza D strains and human influenza C using the guinea pig model.

"If the virus can undergo reassortment in combination with a closely related human influenza virus, it may be able to form a new strain that could pose more of a threat to humans," Kaushik explained.