Knowledge Update

New York, July 8 (IANS) A study of numerous seasonal dark streaks called "recurring slope lineae" or RSLs found at a canyon network on Mars has offered important clues that liquid water could be present on the Red Planet.

Water pulled from the atmosphere by salts, or mechanisms with no flowing water involved, remain possible explanations for the occurrence of RSLs in part of the Valles Marineris region near Mars' equator.

"There are so many of them, it's hard to keep track," said study led author Matthew Chojnacki from the University of Arizona.

"The occurrence of recurring slope lineae in these canyons is much more widespread than previously recognised. As far as we can tell, this is the densest population of them on the planet, so if they are indeed associated with contemporary aqueous activity, that makes this canyon system an even more interesting area than it is just from the spectacular geology alone," he added.

The team examined the geological context of canyonland RSL sites and also calculated how much water would need to be present if the streaks are due to liquid water seeping through a thin surface layer to darken the ground.

Many of the sites where RSLs were previously identified are on inner walls of impact craters. At that type of site, a conceivable explanation could be that an extensive underground layer holding water was punctured by the crater-forming impact long ago and still feeds warm-season flows.

If it is seeping water that darkens RSLs, the amount of liquid water required each year to form the streaks in the studied portion of Valles Marineris would total about 10 to 40 Olympic-size swimming pools (about 30,000 to 100,000 cubic metres), the researchers estimate. 

However, no such underground layer fits the ridge or peak shapes at several of the RSL sites in the new study.

Another possible mechanism previously proposed for RSLs is that some types of salts so strongly pull water vapour out of the Martian atmosphere that liquid brine forms at the ground surface. 

The new study results, reported recently by NASA, bolsters the link between RSL and salts. Some sites bear bright, persistent streaks near the dark, seasonal ones. The bright streaks might result from salt left behind after evaporation of brine.

"There do seem to be more ways atmosphere and surface interact in the canyons than in blander topography, such as clouds trailing out of the canyons and low-lying haze in the canyons," Chojnacki said.

Another factor added by the new study is that RSLs not only darken the surface, but are also associated with material moving downslope. The research documents slumping and other three-dimensional changes at some RSL sites, occurring seasonally in tandem with the streaks.​

New York, July 8 (IANS) A team of astronomers has discovered a strange world with its three suns in the sky, witnessing either constant daylight or triple sunrises and sunsets each day depending on the seasons that may last longer than human lifetimes.

Using direct imaging, the team led by the University of Arizona researchers found that the giant planet HD 131399Ab is unlike any other known world with the widest known orbit within a multi-star system. 

Located about 340 light years from Earth in the constellation Centaurus, HD 131399Ab is believed to be about 16 million years old, making it one of the youngest exoplanets discovered to date. 

"HD 131399Ab is one of the few exoplanets that have been directly imaged, and it's the first one in such an interesting dynamical configuration," said Daniel Apai from the University of Arizona. 

According to study lead author Kevin Wagner, a doctoral student in Apai's research group, for about half of the planet’s orbit, which lasts 550 Earth-years, three stars are visible in the sky, the fainter two always much closer together, and changing in apparent separation from the brightest star throughout the year.

"For much of the planet’s year the stars appear close together, giving it a familiar night-side and day-side with a unique triple-sunset and sunrise each day," Wagner said.

"As the planet orbits and the stars grow farther apart each day, they reach a point where the setting of one coincides with the rising of the other - at which point the planet is in near-constant daytime for about one-quarter of its orbit, or roughly 140 Earth-years," he added.

The study was recently published in the journal Science.

The researchers used the Spectro-Polarimetric High-Contrast Exoplanet Research Instrument (SPHERE) installed on the Very Large Telescope operated by the European Southern Observatory in Chile to make the discovery.

Planets in multi-star systems are of special interest to astronomers and planetary scientists because they provide an example of how planet formation functions in these extreme scenarios. 

While multi-star systems seem exotic to us in our orbit around our solitary star - multi-star systems are in fact just as common as single stars.​

​London, July 9 (IANS) Living near the highway could cost your heart dear as researchers have found that risk of heart attack goes up with the amount of traffic noise to which you are exposed.

The increase in risk - though slight - is greatest with road and rail traffic noise, less with aircraft noise, researchers said.

For the study Andreas Seidler from Germany's Dresden University of Technology and his co-authors evaluated information from statutory health insurers on over a million Germans over the age of 40.

In this case-control study of secondary data, the addresses of persons living in the Rhine-Main region were matched precisely to road, rail, and traffic noise exposure measurements for 2005. 

When the analysis was restricted to patients who died of heart attack up to 2014/2015, a statistically significant association was found between noise exposure and the risk of heart attack. 

The authors believe the lower risk from aircraft noise can be explained by the fact that, unlike road and rail traffic noise, aircraft noise never remains continuously above 65 dB (decibel). 

They also see indications from their analysis that exposure to traffic noise influences not just the genesis, but the course of a heart attack.

The findings appeared in the journal Deutsches Arzteblatt International.

Although strictly speaking these results show only an association between traffic noise and heart attack, the authors believe that the sheer numbers of people affected by noise pollution mean that it is now right to start intensive efforts towards effective prevention of traffic noise. 

This study is part of the Europe-wide NORAH (Noise-Related Annoyance, Cognition, and Health) study investigating the health consequences of traffic noise.​

​London, July 9 (IANS) A team of scientists has demonstrated how the natural movement of bacteria could be harnessed to assemble and power microscopic 'windfarms' - or other man-made micro-machines such as smartphone components.

Using computer simulations, the scientists from Oxford University demonstrated that the chaotic swarming effect of dense active matter such as bacteria can be organised to turn cylindrical rotors and provide a steady power source. 

"Many of society's energy challenges are on the gigawatt scale, but some are downright microscopic. One potential way to generate tiny amounts of power for micromachines might be to harvest it directly from biological systems such as bacteria suspensions," said study co-author Tyler Shendruk.

The study results were published recently in the journal 'Science Advances'.

Swimming bacteria are normally too disordered to extract any useful power from. But when the team immersed a lattice of 64 symmetric microrotors into a dense bacterial suspension, the bacteria spontaneously organised itself in such a way that neighbouring rotors began to spin in opposite directions - a simple structural organisation reminiscent of a windfarm.

"The amazing thing is that we didn't have to pre-design microscopic gear-shaped turbines. The rotors just self-assembled into a sort of bacterial windfarm," Shendruk said.

"When we did the simulation with a single rotor in the bacterial turbulence, it just got kicked around randomly. But when we put an array of rotors in the living fluid, they suddenly formed a regular pattern, with neighbouring rotors spinning in opposite directions," he added.

At micro scales, the simulations show that the flow generated by biological assemblies is capable of reorganising itself in such a way as to generate a persistent mechanical power for rotating an array of microrotors, which could be harnessed to power micro-machines​

​New York, July 9 (IANS) Researchers have discovered a new gene that controls blood vessel formation -- presenting a possible new drug target for cancer and heart disease.

The joint team from Duke-NUS Medical School (Duke-NUS) and the National Heart Centre Singapore (NHCS) uncovered a role for the gene, Wars2, in the process of angiogenesis - a process controlling formation of a network of blood vessels that enables the body to deliver the nutrients necessary to keep the tissues and organs alive and healthy.

"Using different genetic techniques, we inhibited Wars2 function in both rats and zebrafish, and the resulting animals showed impairment of blood vessel formation within the heart and in the rest of the body," said Mao Wang from Duke-NUS, the co-first author of the study.

To confirm the involvement of Wars2 in angiogenesis, the researchers increased the effect of Wars2 and showed that blood vessel formation was enhanced. 

Specifically, they were able to determine that Wars2 plays an important role in supplying sufficient endothelial cells, the building blocks of blood vessels, for angiogenesis, according to the study published recently in the journal Nature Communications.

"Finding a way to control angiogenesis not only provides a target for the development of anti-cancer therapies, but may also prove useful in similarly starving abnormal blood vessel growth elsewhere in the body, like in diabetic eye disease," said Stuart Cook of Duke-NUS.​

London, July 9 (IANS) Cholesterol lowering statins have the potential to significantly reduce mortality and improve survival rates of patients with lung, breast, prostate and bowel cancer, says a study involving an Indian-origin researcher.

"Statins have some of the best mortality evidence amongst all cardiovascular medications and statin use in patients with a diagnosis of high cholesterol is possibly the main reason that this diagnosis appears to be protective against death in patients with lung, breast, prostate and bowel cancer," said Rahul Potluri from Aston University.

High cholesterol is strongly associated with obesity, which in turn, is associated with a higher risk of a number of forms of cancer.

The 14-year study of one million people has found that patients with cancer were less likely to die if they had a diagnosis of high cholesterol than if they did not. 

Having a diagnosis of high cholesterol was associated with a 22 per cent lower risk of death in patients with lung cancer, 43 per cent lower risk of death in breast cancer, 47 per cent lower risk of death in prostate cancer and 30 per cent lower risk of death in bowel cancer.

Previous studies found an association between having high cholesterol and developing breast cancer. Animal studies showed that giving statins for high cholesterol could reduce the risk of breast cancer. 

"Our research suggests that there's something about having a high cholesterol diagnosis that improves survival and the extent to which it did that was quite striking in the four cancers studied," added lead author Paul Carter from Aston University in Birmingham, Britain. 

"The results of this study strengthens the argument for a clinical trial evaluating the possible protective effect of statins and other routinely used cardiovascular medications such as aspirin, blood pressure medications, beta-blockers and ACE inhibitors in patients with cancer," Potluri noted.

In the new study, the team investigated the association between high cholesterol and mortality with lung, breast, prostate and bowel cancer patients, between 1 January 2000 and 31 March 2013. 

Out of a total of 9,29,552 patients, 7997 had lung cancer, 5481 had breast cancer, 4629 had prostate cancer and 4570 had bowel cancer.

"Patients with cancer who are at high risk or have established cardiovascular disease should be given statins as per current guidelines. I don't think at the moment we can give statins for cancer per se. But this could change if there was a positive result in the clinical trial,” Potluri concluded.

The findings were presented at Frontiers in CardioVascular Biology (FCVB) 2016 in Italy, recently.​

​Chicago, July 8 (IANS) How do you build rapport with a new employer or someone on a first date? Eat the same food as your companion, a study has revealed.

According to the study published online in Journal of Consumer Psychology, researchers from the University of Chicago launched a series of experiments to determine whether similar food consumption facilitates a sense of closeness and trust between adults.

The researchers tested the influence of food in a study in which pairs were assigned to opposing sides of a labour negotiation. 

Some pairs ate similar foods during the negotiations while others ate different foods. The pairs that had eaten similar foods reached an agreement almost twice as quickly as the groups that ate dissimilar foods.

"People tend to think that they use logic to make decisions, and they are largely unaware that food preferences can influence their thinking. On a very basic level, food can be used strategically to help people work together and build trust," said Ayelet Fishbach, Professor, University of Chicago.

At large group meetings, organisers could limit the number of food options in order to encourage similar food consumption, which could lead to increased trust and collaboration, suggested the study.

The researchers also discovered that these findings applied to marketing products. Participants trusted information from advertisers when consumers ate the same type of food as advertisers giving a testimonial about the product.​

​Vienna, July 8 (IANS) Weight loss from bariatric surgery appears to reverse the premature ageing associated with obesity, according to a research.

The study revealed whether bariatric surgery -- a procedure that bypasses the gastrointestinal tract and leaves only a pouch of stomach and the resulting weight loss could reverse the premature ageing in obese patients.

The study included 76 patients who were 40 years old on average and had a body mass index (BMI) of at least 35 kg/m2. The average BMI was 44.5 kg/m2. All patients had been unable to lose weight through lifestyle changes and were referred for bariatric surgery.

The researchers collected blood samples before surgery and one and two years afterwards. They compared the levels of premature ageing markers in the blood before and after surgery.

One year after surgery BMI had significantly dropped to an average of 27.5 kg/m2, which amounts to a 38 per cent reduction.

This was accompanied by decreases in the pro-inflammatory cytokines plasminogen activator inhibitor-1 and interleukin-6 and an increase in the anti-inflammatory cytokine interleukin-10.

"Obese people are prematurely old. Bariatric surgery drastically reduces the amount of food patients can eat. People lose around 30 to 40 per cent of their whole body weight in the first year," said Philipp Hohensinner, Researcher at the Medical University of Vienna.

Patients had longer telomeres and less inflammation two years later. Telomeres are the internal clock of each cell. Telomeres get shorter when a cell divides or when oxidative stress causes them to break. 

When the telomeres get very short the cell can no longer divide and is replenished or stays in the body as an aged cell. Previous research found that obese women had shorter telomeres compared to women with a healthy weight, which amounted to an added eight years of life.

Two years after surgery, patients had telomeres that were 80 per cent longer than they had been before the procedure. The researchers also evaluated telomere oxidation which causes the telomeres to break and get shorter.​

Toronto, July 8 (IANS) Recent public education campaigns recommending home blood pressure monitoring may have inadvertently contributed to the rise in emergency visits for hypertension, a study says.

The findings do not suggest that home blood pressure monitoring should be discouraged. What it says is that high blood pressure in itself is not necessarily an emergency.

But aggressive home monitoring of blood pressure may be driving patients to emergency departments despite the lack of other emergency conditions, such as stroke.

"We encourage patients to monitor their blood pressure at home if they have been diagnosed with hypertension, but not every high blood pressure reading is an emergency," explained lead study author Clare Atzema from Sunnybrook Health Sciences Centre in Toronto, Ontario, Canada.

During the study period, between 2002 and 2012, in which visits to Ontario emergency departments for hypertension increased from 15,793 to 25,950 per year, the proportion of patients admitted to the hospital as a result decreased from 9.9 per cent to 7.1 per cent. 

Among the patients whose emergency department visit ended in admission to the hospital, the most frequent hospital diagnoses were stroke, renal failure and heart failure. 

"Stroke remains a huge killer and we do appreciate patients with hypertension being so conscientious about monitoring their readings," Atzema noted. 

The study was published online in Annals of Emergency Medicine, journal for the American College of Emergency Physicians.

"Patients should be aware that unless their high blood pressure coincides with symptoms of a medical emergency, such as chest pain, severe headache, nausea or shortness of breath, they probably do not need to visit the ER emergency room),” Atzema said.

"We of course encourage them to follow up as soon as possible with their regular physician. If there is any doubt, come to the emergency department: we would rather have you come without an emergency than stay home with one," Atzema pointed out.​