Knowledge Update

​Washington, Sep 30 (IANS) Using data from NASA's Fermi Gamma-ray Space Telescope, scientists have found the first gamma-ray binary in another galaxy and the most luminous one ever seen.

The dual-star system, dubbed LMC P3, contains a massive star and a crushed stellar core that interact to produce a cyclic flood of gamma rays, the highest-energy form of light.

"Fermi has detected only five of these systems in our own galaxy, so finding one so luminous and distant is quite exciting," said lead researcher Robin Corbet from NASA's Goddard Space Flight Center in Greenbelt, Maryland.

Gamma-ray binaries are prized because the gamma-ray output changes significantly during each orbit and sometimes over longer time scales.

"This variation lets us study many of the emission processes common to other gamma-ray sources in unique detail," Corbet added.

These rare systems contain either a neutron star or a black hole and radiate most of their energy in the form of gamma rays.

LMC P3 is the most luminous such system known in gamma rays, X-rays, radio waves and visible light, and it's only the second one discovered with Fermi.

LMC P3 lies within the expanding debris of a supernova explosion located in the Large Magellanic Cloud (LMC), a small nearby galaxy about 163,000 light-years away.

In 2012, scientists using NASA's Chandra X-ray Observatory found a strong X-ray source within the supernova remnant and showed that it was orbiting a hot, young star many times the sun's mass.

Corbet's team discovered a 10.3-day cyclic change centred near one of several gamma-ray point sources recently identified in the LMC.

Prior to Fermi's launch, gamma-ray binaries were expected to be more numerous than they have turned out to be.

"It is certainly a surprise to detect a gamma-ray binary in another galaxy before we find more of them in our own," said Guillaume Dubus, a team member at the Institute of Planetology and Astrophysics of Grenoble in France.

A paper describing the discovery is forthcoming in The Astrophysical Journal.

New York, Sep 30 (IANS) Hypertension or high blood pressure is rapidly increasing in children, largely as a consequence of their obesity.

This high blood pressure in children and adolescents can significantly affect their mental skills, a study has found. 

In the study, children with hypertension performed low on cognitive tests on visual and verbal memory, processing speed, and verbal skills.

Children with sleep issues were found to have had hypertension, which intensified the effect of poor sleep on cognition and executive function, the researchers said. 

Knowing how these physical changes might affect cognitive skills could be important in future studies that assess whether anti-hypertensive treatments could improve cognitive performance in children with hypertension and reverse or prevent future adult hypertension-related problems, said Marc B. Lande from the University of Rochester in New York, US.

In the study, researchers compared different tests of cognitive skills in 75 children aged between 10-18 years with newly-diagnosed hypertension and 75 children without hypertension. 

The children with hypertension were not cognitively impaired, but rather performing less well than children without hypertension.

Overall, this study provides evidence that hypertension in children is associated with a subtle pattern of decreased performance on cognitive testing, the authors concluded. 

The study is forthcoming in The Journal of Pediatrics.

​New York, Oct 1 (IANS) Do we have an inherited hunting instinct, like dogs, cats and other predators? Quite likely, as the popularity of the augmented reality game Pokemon Go suggests, according to a new study.

Pokemon Go allows players to catch virtual wild animals in real-world locations through the mobile phone camera.

"It is possible that we all have the hunting instinct, but it has never been proven," said study author Vladimir Dinets, Assistant Research Professor of Psychology at University of Tennessee, Knoxville in the US.

"The recent explosive popularity of the Pokemon Go game, which allows players to hunt for virtual animals across a real terrain, shows how addictive such proxies can be and how many people can enjoy hunting-like behaviour despite being city dwellers completely isolated from natural environments," Dinets said. 

Hunting has played a major role in human history, helping humans survive and populate the world, but whether we have a an inherited hunting instinct or not is not known.

"The take-home message of the study is that we have predatory instincts and have to be aware of them. But this doesn't mean that we have to be real predators; instead, we can follow these instincts in more intelligent ways," Dinets added.

The study was published recently in the open-access journal Humanimalia.

New York, Sep 30 (IANS) Humans reached the southern cone of South America some 14,000 years ago, earlier than previously thought, says a study based on ancient artifacts found at an archaeological site in Argentina.

Humans' arrival in southern South America 14,000 years ago may represent the last step in the expansion of Homo sapiens throughout the world and the final continental colonisation, the researchers said.

Approximately 13,000 years ago, a prehistoric group of hunter-gathers known as the Clovis people lived in Northern America. 

Previous research suggests that the Clovis culture was one of the earliest cultures in South America. 

However, the new research from the Pampas region of Argentina supports the hypothesis that early Homo sapiens arrived in the South America earlier than the Clovis hunters did.

The evidence for earlier human arrival in South Americas comes from a rich archaeological site in southeastern South America called Arroyo Seco 2. 

"The Arroyo Seco 2 site contains a rich archaeological record, exceptional for South America, to explain the expansion of Homo sapiens into the Americas and their interaction with extinct Pleistocene mammals," the study said.

A group of scientists led by Gustavo Politis from Universidad Nacional del Centro de la Provincia de Buenos Aires presented the research in a new study published in the journal PLOS ONE.

At Arroyo Seco 2, the researchers excavated ancient tools, bone remains from a variety of extinct species, and broken animal bones containing fractures caused by human tools. 

They used radiocarbon dating to determine the age of the mammal bones and analyzed the specimens under a microscope.

The analysis revealed the presence of limb bones from extinct mammals at the site, which may indicate human activities of transporting and depositing animal carcasses for consumption at a temporary camp. 

The bones of some mammal species were concentrated in a specific part of the site, which could indicate designated areas for butchering activities. 

Microscopic examination also revealed that some bones contained fractures most likely caused by stone tools. 

The remains were dated between 14,064 and 13,068 years ago, and the authors believe that Arroyo Seco 2 may have been occupied by humans during that time.

This timeline, along with evidence from other South American sites, indicates that humans may have arrived in southern South America prior to the Clovis people inhabiting the Americas, but after the onset of the Last Glacial Maximum, the last glacial period, which took place 19,000 to 20,000 years ago, the researchers said.

Washington, Sep 30 (IANS) Chemistry in the surface material on Mars contributed dynamically to the make-up of its atmosphere over time, a study has found.

The findings come from the NASA's Curiosity rover's Sample Analysis at Mars, or SAM, instrument suite, which studied the gases xenon and krypton in the Mars atmosphere.

The two gases can be used as tracers to help scientists investigate the evolution and erosion of the Martian atmosphere. 

The SAM team ran a series of first-of-a-kind experiments to measure all the isotopes of xenon and krypton in the Martian atmosphere, a paper published in the journal Earth and Planetary Science Letters said.

The team's method is called static mass spectrometry, and it is good for detecting gases or isotopes that are present only in trace amounts. 

"The unique capability to measure in situ the six and nine different isotopes of krypton and xenon allows scientists to delve into the complex interactions between the Martian atmosphere and crust," said Michael Meyer, lead scientist for the Mars Exploration Programme at NASA Headquarters in Washington. 

"Discovering these interactions through time allows us to gain a greater understanding of planetary evolution," Meyer noted.

A lot of information about xenon and krypton in Mars' atmosphere came from analyses of Martian meteorites and measurements made by the Viking mission.

"What we found is that earlier studies of xenon and krypton only told part of the story," lead author of the report Pamela Conrad, and SAM's Deputy Principal Investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland, said.

"SAM is now giving us the first complete in situ benchmark against which to compare meteorite measurements," Conrad noted.

New York, Sep 25 (IANS) Healthy city design and planning in densely populated countries like India can reduce growing epidemics, injuries and non-communicable (NCD) diseases such as heart disease, diabetes and cancer, finds a new study.

According to the study, published in the journal The Lancet, health gains can be achieved if cities are designed in a way that shops, facilities, work and public transportation are within walking distance of most residents.

By 2050, the US, China and India are predicted to see their populations increase by 33, 38 and 96 per cent respectively, the study found.

Sprawling residential developments lead to declines in physical activity, increases in air pollution and higher rates of road death and serious injury.

Researchers studied how to implement timely research into city design, planning and policy to improve the health of a city's residents. 

"Shifting from city infrastructure that encourages the use of automobiles to a design providing safe and easy walking, cycling and public transportation options would reduce traffic injuries, air pollution and physical inactivity," said James F. Sallis, researcher at the University of California San Diego School of Medicine, US.

Additionally, limitations in the ability of people to walk or cycle in their daily commute makes public transportation expensive to deliver, which can lead to an increase in chronic disease and injury.

"Many city leaders around the world are not applying the lessons of research to make cities as healthy as possible," said Sallis.

To improve the effectiveness and implementation of research, Sallis and team suggested that studies must include collaborations between scientists and multisector policy makers and address questions that are relevant to city leaders, including information about public opinion and costs. 

"City planning policies can affect health, both positively and negatively. A major incentive to make changes now is that designing cities for health and active transport, rather than automobile-dependence also makes the cities more environmentally sustainable," Sallis added.

London, Sep 26 (IANS) Low and moderate levels of physical activity may significantly lower the risk of bacterial infection, a new study has found.

Regular physical activity is known to have various health benefits including reduced risk of obesity, cardiovascular diseases, diabetes, colon and breast cancer, as well as depression.

The results showed that compared with sedentary behaviour, low leisure-time physical activity was associated with a 10 per cent lower risk of any suspected bacterial infection, said Kathrine Pape Madsen from the Aalborg University, in Denmark.

Further, compared with individuals classified as sedentary, those undertaking low and moderate levels of leisure-time physical activity were associated with a 21 per cent and 32 per cent reduction of suspected cystitis -- urinary tract infections. 

Suspected respiratory tract bacterial infections, however, were not associated with physical activity level, the study said.

Physical inactivity has been identified as the fourth leading risk factor for global mortality causing an estimated 3.2 million deaths globally, according to World health Organisation.

In the study, the researchers examined the relationship between leisure-time physical activity and suspected bacterial infections during a one-year follow up.

Information on leisure-time physical activity was obtained from the 2007 and 2010 North Denmark Region Health Surveys of 18,874 Danes. 

Suspected bacterial infections were determined based on filled prescriptions for antibiotics. 

During a one year follow-up, 5368 participants filled at least one antibiotic prescription.

There was a statistically significant difference between physical activity level and filling any antibiotic prescriptions among women but not among men.

Washington, Sep 26 (IANS) Scientist have developed a set of five instruments that can potentially advance NASAs understanding of wind and weather conditions on the surface of Mars that can help ascertain the planet's habitability.

The US space agency sends rovers to the surface of Mars to photograph the landscape and operate scientific experiments to understand the habitat for humans or other kinds of life.

One of those future rover missions may host the Martian Aqueous Habitat Reconnaissance Suite (MAHRS), a set of five instruments that can take surface measurements in the search for habitable environments, NASA said.

Developed at NASA Glenn Research Centre in partnership with the University of Michigan, MAHRS is specifically focused on searching for wet brine environments in the shallow subsurface of Mars.

"Brine environments are where you would look for life," said Project Manager Dan Vento of NASA.

"Any water that exists today on Mars would likely be in the form of a brine if is in a liquid state," he added.

The MAHRS research hardware includes an optical microscope to study the size and characteristics of settling dust on Mars. 

"The interesting feature about the microscope, is that the electronics architecture can support a camera lens or hyperspectral sensor depending on the scientific goals of the mission," Norman Prokop from NASA Glenn Research Centre said.

Mounted to the microscope, a radiometre measures the amount of solar energy absorbed at the surface to study the amount of dust in the Martian atmosphere. 

Less energy making it to the surface means more dust in the atmosphere is absorbing the solar energy.

A saltation probe, which would hang vertically off the bottom of a rover, measures the impact of soil and dust swirling on the Martian surface. 

Because it is close to the ground, it can measure the impact, mass and velocity of soil as it hits the probe, giving researchers an indication of wind energy and soil movement.

The scientists also developed a soil wetness sensor, which measures water content on the surface and detects the formation of liquid brine.

And finally, Michigan engineers are testing an electric field sensor to measure electrical charges in the atmosphere caused by airborne dust, NASA said. As it sits and spins on a rover arm, it will measure weather patterns and indicate the level of erosion on Mars.

As NASA seeks to develop more sophisticated scientific devices for solar system exploration, this integrated suite of instruments can potentially advance understanding of wind and weather conditions on the surface of Mars and the implications for habitability.

NASA's Mars rover missions advance understanding about the Red Planet and serves in preparation for planned human-crew missions to Mars beginning in the 2030s.

​Sydney, Sep 26 (IANS) Managing diabetes could become much cheaper and simpler as researchers in Australia have developed a copper film that can detect glucose from body fluids containing salt, such as sweat or tears.

Researchers at the University of Wollongong's (UOW) Institute for Superconducting and Electronic Materials (ISEM) reported demonstration of the first construction of copper with a sponge-like porous structure, which can quickly and accurately detect glucose in salt-based fluids.

"The sponge-like porous structure greatly increases the surface area and therefore enhances the sensitivity required to trigger an electrochemical signal," said Professor Yusuke Yamauchi.

"The extraordinary sensing performance of the copper film is probably attributed to its intrinsically good reaction toward glucose oxidation," Yamauchi noted.

"This makes this copper film a good candidate for the direct detection of glucose to satisfy the requirements of diverse applications, such as diabetes management," he added.

People with diabetes often have low levels of insulin, a hormone that converts sugars to energy, which means they have to closely watch their glucose or blood-sugar levels to prevent further chronic health complications.

Foods, physical activity and other factors can influence glucose levels.

This has led medical device manufactures toward developing continuous glucose monitors that can be inserted just under the skin, providing the wearer with regular blood-sugar readings, removing the need for regular finger-pricking to extract a drop of blood for sugar measurement.

But the technology remains expensive, mainly due to the use of precious metals such as platinum in the sensor.

"Precious metals such as gold and platinum have very good conductivity but they are very expensive and we wanted to focus on more abundant and cheaper metals," Yamauchi said.

So the researchers developed a porous copper film with the sponge-like structure.

Testing revealed the film has high selectivity, reacting to glucose without interference from other acids and sugars that can be present in sweat, said the study published in the journal Angewandte Chemie.

The researchers believe the copper film could be integrated into a wearable sensor or a smartwatch, providing continual glucose readings to the wearer, which could also be sent via wireless to their doctor.

Washington, Sep 27 (IANS) Nasa on Monday released further evidence to show that there may be oceans on Europa -- Jupiter's largest moon.

Releasing new images captured from the Hubble Space Telescope, the space research organisation announced "surprising evidence of activity" on Europa which could be water vapour erupting from the icy moon, the telegraph reported.

Hubble made its latest identification by studying Europa as it passed in front of Jupiter.

The telescope looked in ultraviolet wavelengths to see if the giant planet's light was in any way being absorbed by material emanating from the moon's surface.

Ten times Hubble looked and on three of those occasions it spied what appeared to be "dark fingers" extending from the edge of Europa.

William Sparks, the lead astronomer on the study, said he could think of no natural phenomenon other than water plumes that might produce such protuberances.

"We're not aware of any instrumental artefacts that could cause these features; they are statistically significant. But we remain cautious because we are working at difficult wavelengths for Hubble," the BBC quoted him as saying.

"We do not claim to have proven the existence of plumes, but rather to have contributed evidence that such activity may be present."

Nonetheless, the location for the putative jets looks very similar to the region where Hubble earlier this decade detected an excess of oxygen and hydrogen -- the component parts of water, the BBC reported.

Europa is one of the largest of Jupiter's 67 known moons. In late 2013 the Hubble telescope observed water vapour erupting from Europa, in what was hailed as a ‘tremendously exciting' discovery.

Previous scientific findings had already pointed to the existence of an ocean located under Europa's icy crust, but it was thought teams in the future would have to drill through the thick layer of ice before any signs of life would be detectable.

Lorenz Roth of Southwest Research Institute in San Antonio said at the time that if the plumes of vapour were connected to the ocean beneath the crust they could start searching for life nearer the surface.

"This means that future investigations can directly investigate the chemical makeup of Europa's potentially habitable environment without drilling through layers of ice," the telegraph quoted him as saying.

"And that is tremendously exciting."

Participants in the teleconference included Paul Hertz, director of NASA's Astrophysics Division; William Sparks of the Space Telescope Science Institute in Baltimore; Britney Schmidt of the Georgia Institute of Technology; and Jennifer Wiseman, senior Hubble project scientist at NASA's Goddard Space Flight Centre.