Knowledge Update

Mumbai, Dec 15 (IANS) A study by Indian researchers suggests that a population of neutron stars can generate gravitational waves continuously, a finding that could provide an opportunity to study these waves almost permanently.

The study by Professor Sudip Bhattacharyya of the Tata Institute of Fundamental Research (TIFR), Mumbai, and Professor Deepto Chakrabarty of the Massachusetts Institute of Technology (MIT) in the US found that a population of neutron stars should spin around their axes much faster than the highest observed spin rate of any neutron star. 

The observed lower spin rates are possible if these neutron stars emit gravitational waves continuously, and hence spin down, the researchers said.

Gravitational waves emitted by massive objects is a prediction of Albert Einstein's general theory of relativity, which has recently been discovered during transient phenomena of black hole mergers. 

But the detection of continuous gravitational waves, which could provide an opportunity to study these waves almost permanently, is still elusive. 

Neutron stars are the densest observable objects in the universe, with a fistful of stellar material outweighing a mountain on Earth. 

While such stars are not bigger than a city, in size, they have more material than in the Sun crammed inside them. 

A population of these stars can increase their spin rate by the transfer of matter from a normal companion star. 

In fact, some of them have been observed to spin several hundred times in a second around their own axes.

In the 1970s, it was theoretically worked out how fast these neutron stars could spin, and since then this has formed the basis of studies of these stars. 

But the new study -- published in the The Astrophysical Journal -- showed that for episodic mass transfer, which happens for many neutron stars, the stellar spin rate should be much higher, and the star could easily attain a spin rate more than a thousand times per second. 

Since no neutron star has been observed with such a high spin rate, the team pointed out that many of these stars are likely to be slowed down by continuously emitting gravitational waves.

The new study provides a strong indication that many fast spinning neutron stars generate gravitational waves continuously, and careful observations should be made to detect such waves.

​Washington, Dec 15 (IANS) US space agency NASA launched a constellation of eight small satellites on Thursday designed to aid weather forecasters in understanding and predicting hurricane intensity.

The eight observatories comprising the Cyclone Global Navigation Satellite System (CYGNSS) were delivered to a low-Earth orbit by the US aerospace firm Orbital ATK's Pegasus XL rocket at 8.37 a.m. (local time), Xinhua news agency reported.

The rocket and its micro-satellite payload were air-launched from Orbital ATK's modified L-1011 aircraft, nicknamed Stargazer, which first flew to about 39,000 feet over the Atlantic Ocean and then released the rocket.

NASA said the $157 million CYGNSS mission will team up with the Global Positioning System (GPS) constellation to measure ocean surface winds in and near the eye of the storm throughout the life cycle of hurricanes.

"This will be the first time that satellites can peer through heavy tropical rainfall into the middle of hurricanes and predict how intense they are before and during landfall," it added.

​London, Dec 15 (IANS) Researchers have in a breakthrough study found that brains of people genetically inclined towards Alzheimer's are likely to show abnormal immune reactions as early as about seven years before the expected onset of dementia.

These immune responses can be detected by means of a protein known as "TREM2" and found in the cerebrospinal fluid, offering physicians the possibility to trace the progression of the disease, the study said. 

Thus, when the researchers measured the levels of TREM2 -- segregated by certain immune cells of the brain called microglia -- they were able to detect an increasing immune activity of the brain. 

"The activity of the microglia is stimulated by the dying brain cells, not by the deposits of amyloid proteins, called plaques, which also occur in Alzheimer's disease," said Christian Haass, Professor at Ludwig Maximilian University (LMU) in Munich, Germany.

The rise of TREM2 levels years before the expected occurrence of dementia symptoms can be monitored and thus the timing for the onset of dementia can be precisely predicted, the researchers noted.

"TREM2 levels could therefore be a biomarker used to track immune activity while Alzheimer's is progressing, irrespective of whether the disease is genetic or not. TREM2 may also serve as a therapeutic marker to monitor drug response," explained Michael Ewers, Professor at Ludwig Maximilian University (LMU). 

For the study, the team included 127 individuals, with an average age of 40 years, who had a genetic predisposition to Alzheimer's. The vast majority showed no symptoms of dementia or had only minor cognitive impairments. 

The study results are published in the journal Science Translational Medicine.

​London, Dec 15 (IANS) A cost-effective saliva test may have the potential to act as non-invasive marker of immunity and thus enable assessment of vaccination and protection against bacterial infections such as pneumococcal infections in the human body, a study has found.

Saliva test can be an attractive method of specimen collection particularly for children and the elderly, the researchers said.

"Saliva sampling is non-invasive, requires no specialist training or equipment, and may be more cost-effective," said lead author Jennifer Heaney from the University of Birmingham in Britain.

The study showed that IgG Pn antibodies in saliva correlated with antibody levels in serum in infants. 

Protection against bacterial infection is usually inferred by measuring antibody levels in blood serum.

But taking blood samples involves a number of logistical considerations and may not always be feasible, especially in developing countries or where children are involved. 


"The suggestion that antibody levels in saliva may be indicative of those in serum therefore has important implications for markers of immunity and vaccination in many parts of the world," Heaney added. 

Previous research showed that lower levels of antibodies in saliva are associated with of an elevated risk of mortality, and that saliva sampling to determine IgA secretion rate has the potential to be used as an indicator of overall health by professionals as part of a general check-up.

For the study, samples of both blood and saliva were taken from 72 healthy adults. Samples were then analysed to test for concentrations of IgG, IgM and IgA antibodies against 12 pneumococcal (Pn) antigens.

The results showed that in general, higher antibody concentrations in serum were associated with higher concentrations in saliva, with the strongest relationships observed for IgA antibodies.

The study was published in the journal Biomarkers.

​Beijing, Dec 14 (IANS) Video bloggers in China must register their real identities before publishing anything online from January 1, the Ministry of Culture announced Wednesday.

New York, Dec 14 (IANS) Researchers at the University of Wisconsin - Madison in the US are developing a smartphone app that can help reduce risk of injuries in factory workers due to the strain of repetitive motion required to perform their work.

​Colombo, Dec 14 (IANS) The Maldives tourism industry has seen a remarkable growth this year, contributing to strengthening the archipelago nation's economy, the country's embassy in Colombo said on Wednesday.

"The growth has been achieved with the dynamic economic policies introduced by President Abdullah Yameen to transform the economy of Maldives," Xinhua news agency cited an embassy statement as saying.

Maldives this year unveiled seven new resorts, including Huravalhi Island Resort, featuring the world's largest underwater restaurant.

The government said 20 new resorts would be unveiled next year.

"With the opening of the new resorts and influx of tourism investments, the industry has become a catalyst for the governments key pledge of youth employment," the embassy statement said.

In addition to the new resorts in April, the government also launched the expansion of the Ibrahim Nasir International Airport with a 3,400 metre long and 65 metre wide new runway to cater to the expanding tourism industry.

Upon completion of the expansion, 7.5 million passengers would be catered annually, creating thousands of job opportunities for the youth of the country.

​New York, Dec 14 (IANS) Researchers have found that eating food low in carbohydrates is safe for up to six months and can also help reduce more weight than following a low-fat diet. "Adhering to a short-term low-carb diet appears to be safe and may be associated with weight reduction," said lead researcher Heather Fields, MD, an internal medicine physician at Mayo Clinic in Arizona, US. "We encourage patient to eat real food and avoid highly processed foods, especially processed meats, such as bacon, sausage, deli meats, hot dogs, and ham when following any particular diet," Fields noted. Depending on the diet, participants lost between two-and-a-half to almost nine more pounds than those who followed a low-fat diet, showed the findings published in the Journal of the American Osteopathic Association. Analysing research published over more than a decade, Fields reviewed articles that addressed potential adverse effects and overall safety of low-carb diets. Diets that heavily restrict carbohydrates often lead to greater consumption of meats -- some of which have been implicated in worsened all-cause mortality and increased cancer risk. While available studies did not consistently address the source or quality of proteins and fats consumed in such diets, they did show short-term efficacy in weight loss without negative effects on blood pressure, glucose, and cholesterol, compared with other diets.

New York, Dec 14 (IANS) Claimed to boost physical activity levels and promote public health, augmented reality game Pokemon Go's health benefits are just moderate as well as short-lived, researchers say. Pokemon Go is a smartphone-based game that projects graphics onto the real world and has been downloaded over 500 million times since its launch in July 2016 in many countries. The findings showed that the game improves physical activity such as walking only moderately, and the effect is lost in a matter of six weeks. The first week of installation saw that the daily average steps increased by 955 additional steps. However, the number of steps gradually decreased over the following five weeks and by the sixth week the number had returned to pre-installation levels. "Our results indicate that the health impact of Pokemon Go might be moderate. Even if smaller amounts of physical activity might also be important for health outcomes, the increase in steps from Pokemon Go, as with many physical activity interventions, was not sustained over time," said Katherine Howe from Harvard University. The results remained the same even after accounting for a number of factors that may have influenced the findings, such as age, sex, race, weight status, and walkability of the area of residence, the study reported. "Over a six-week period one can do a lot to increase physical activity. We just have to be more creative about finding ways to get people to keep exercising," the researchers said. Further, the effect of Pokemon Go on physical activity might be different in children, and there might also be other potential benefits associated with the game, such as increased social connectedness and improved mood, they added. For the study, published in the journal BMJ, researchers conducted an online survey of 1,182 participants, out of which 560 between the age of 18-35, reported playing Pokemon Go.

​New York, Dec 14 (IANS) NASA's Curiosity rover has detected boron for the first time on the surface of Mars, indicating the potential for long-term habitable groundwater in the ancient past.

"No prior mission to Mars has found boron," said Patrick Gasda of the US Department of Energy's Los Alamos National Laboratory in New Mexico. 

"If the boron that we found in calcium sulfate mineral veins on Mars is similar to what we see on Earth, it would indicate that the groundwater of ancient Mars that formed these veins would have been 0-60 degrees Celsius and neutral-to-alkaline pH," Gasda noted.

The temperature, pH, and dissolved mineral content of the groundwater could make it habitable, according to the scientists.

The boron was identified by the rover's laser-shooting Chemistry and Camera (ChemCam) instrument, which was developed at Los Alamos National Laboratory in conjunction with the French space agency. 

Boron is famously associated with arid sites where much water has evaporated away. However, environmental implications of the boron found by Curiosity are still open to debate.

Whether Martian life has ever existed is still unknown. No compelling evidence for it has been found. When Curiosity landed in Mars' Gale Crater in 2012 the mission's main goal was to determine whether the area ever offered an environment favourable for microbes.

Curiosity is currently climbing a layered Martian mountain and finding rock-composition evidence of how ancient lakes and wet underground environments changed, billions of years ago.

The discovery of boron is only one of several recent findings related to the composition of Martian rocks. 

Hematite and clay minerals are among the other ingredients found to be more abundant in layers farther uphill, compared with lower, older layers examined earlier in the mission.

"The boron and clay underline the mobility of elements and electrons, and that is good for life," John Grotzinger of the California Institute of Technology, Pasadena, California, pointed out.

The findings were discussed in San Francisco during the American Geophysical Union conference.