Knowledge Update

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.

Washington, Sep 27 (IANS) The moon was formed by a planetary object hitting the infant Earth some 4.5 billion years ago, say researchers who studied a layer of iron and other elements.

The authors argue this was the same impact that sent a great mass of debris hurtling into space, creating the moon.

The scientists used laboratory simulations of an Earth impact as evidence that a stratified layer beneath the rocky mantle -- which appears in seismic data -- was created when Earth was struck by a smaller object.

"Our experiments bring additional evidence in favour of the giant impact hypothesis," said Maylis Landeau, post-doctoral fellow in Johns Hopkins University's department of Earth and Planetary Sciences.

"The giant impact scenario also explains the stratification inferred by seismology at the top of the present-day Earth's core. This result ties the present-day structure of Earth's core to its formation," added Landeau, now a Marie Curie Fellow at University of Cambridge.

According to Peter Olson, Research Professor at Johns Hopkins, the giant impact argument for the formation of the moon is the most prevalent scientific hypothesis on how Earth satellite was formed, but it is still considered unproven because there's been no "smoking gun" evidence.

"We're saying this stratified layer might be the smoking gun," said Olson. "Its properties are consistent with it being a vestige of that impact."

Their argument is based on seismic evidence of the composition of the stratified layer -- believed to be some 200 miles thick and lie 1,800 miles below Earth's surface -- and on laboratory experiments simulating the turbulence of the impact.

The turbulence, in particular, is believed to account for the stratification -- meaning a mix of materials in layers rather than a homogeneous composition -- at the top of the core.

The stratified layer is believed to consist of a mix of iron and lighter elements, including oxygen, sulphur and silicon.

The very existence of this layer is understood from seismic imaging, as it lies far too deep underground to be sampled directly.

The study was published in the journal Nature Geoscience.

London, Sep 27 (IANS) Bilingual educational programmes in those subjects that were taught in English have a negative effect on the level of competence and knowledge in students, finds a study.

Bilingual education programmes, in which a substantial part of the teaching is done in a language different from the mother tongue and from the language of the students' surroundings, have been introduced in countries such as India, Spain and the US. 

The researchers analysed the effects of these programmes and have found a negative effect on the level of competence and knowledge displayed by the students who have followed this bilingual programme in those subjects that were taught in English.

The study, which was published in the journal Economic Inquiry, used data from the test of essential knowledge administered by the Community of Madrid when students complete their elementary education.

"These students and teachers are making an additional effort because they have to teach and learn the subjects in a language that is not theirs. They have to spend more time and make a greater effort to learn English, which can affect their learning of the specific material taught in subjects such as Science, History and Geography," said Jesus Carro, researcher at the Universidad Carlos III de Madrid, Spain.

This negative result is more pronounced in those students whose parents have a lower level of education, while the difference is hardly noticeable in students whose parents have a higher level of studies.

"We can establish a number of hypotheses with the regard to the reasons behind this, such as that they receive more help at home, they have greater resources, they are more exposed to situations where other languages are used or that are linguistically richer," Carro added. 

According to the study, it is possible that the negative effect that has been detected will disappear at that point because, in secondary school, the students have a higher level of English

​New York, Sep 27 (IANS) Scientists know that stimulating the brain via electricity or other means may help ease the symptoms of various neurological and psychiatric disorders like epilepsy and depression.

Now, researchers from the University of Pennsylvania and University at Buffalo have discovered that stimulation of a single region of the brain affects the activation of other regions and large-scale activity within the brain.

"We don't have a good understanding of the effects of brain stimulation," said first author Sarah Muldoon, assistant professor of mathematics in University at Buffalo's college of arts and sciences.

"When a clinician has a patient with a certain disorder, how can they decide which parts of the brain to stimulate? Our study is a step toward better understanding how brain connectivity can better inform these decisions," she added.

If you look at the architecture of the brain, it appears to be a network of interconnected regions that interact with each other in complicated ways. 

"The question we asked in this study was how much of the brain is activated by stimulating a single region. We found that some regions have the ability to steer the brain into a variety of states very easily when stimulated, while other regions have less of an effect," explained Danielle S Bassett, associate professor of bioengineering in the University of Pennsylvania.

The study used a computational model to simulate brain activity in eight individuals whose brain architecture was mapped.

The research examined the impact of stimulating each of 83 regions within each subject's brain. While results varied by person, common trends emerged.

Network hubs -- areas of the brain that are strongly connected to other parts of the brain via the brain's white matter -- displayed what researchers call a "high functional effect": 

Stimulating these regions resulted in the global activation of many brain regions.

These patterns suggest that doctors could pursue two classes of therapies when it comes to brain stimulation: a "broad reset" that alters global brain dynamics, or a more targeted approach that focuses on the dynamics of just a few regions.

The research was published in the journal PLOS Computational Biology.

New York, Sep 28 (IANS) US researchers have designed a peptide-based nanoparticle, which when injected into an injured joint will not only suppress the inflammation immediately but also reduce the destruction of cartilage, thus lowering the risk for osteoarthritis.

Osteoarthritis is a type of arthritis that occurs when flexible tissue at the ends of bones wears down.

In this study, the nanoparticles were injected locally shortly after injury into the joint of the participants to penetrate into the injured cartilage to prevent cartilage breakdown that could eventually cause osteoarthritis. 

Within 24 hours the nanoparticles were at work to tame the inflammation in the joint, the researchers said. 

"These nanoparticles remain in the joint longer (than the traditional anti-inflammotory drugs) and help prevent cartilage degeneration," said Associate Professor Christine Pham from Washington University in St. Louis in the US. 

"The nanoparticles are injected directly into the joint, and due to their size, they easily penetrate into the cartilage to enter the injured cells," added Professor Samuel Wickline of Washington University. 

The newly developed nanoparticles carry a peptide derived from a natural protein called melittin that has been modified to enable it to bind to a molecule called small interfering RNA (siRNA). 

The melittin delivers siRNA to the damaged joint, interfering with inflammation in cells.

It is more than 10 times smaller than a red blood cell, which helps them penetrate deeply into tissues, the researchers noted. 

The findings were reported online in the early edition of the Proceedings of the National Academy of Sciences.