Knowledge Update

​London, Feb 1 (IANS) Observing a curious neutron star in a binary system known as the 'Rapid Burster', scientists have found that its magnetic field could explain 40-year-old mystery surrounding its puzzling X-ray bursts.

Discovered in the 1970s, the Rapid Burster is a binary system comprising a low-mass star in its prime and a neutron star -- the compact remnant of a massive star's demise. 

The scientists discovered that its magnetic field creates a gap around the star, largely preventing it from feeding on matter from its stellar companion. 

Gas builds up until, under certain conditions, it hits the neutron star all at once, producing intense flashes of X-rays. 

The discovery, reported in the journal Monthly Notices of the Royal Astronomical Society: Letters, was made with space telescopes including European Space Agency's XMM-Newton and NASA's NuSTAR (Nuclear Spectroscopic Telescope Array) and Swift missions.

In a a binary system known as the 'Rapid Burster', the gravitational pull of the dense remnant strips the other star of some of its gas; the gas forms an accretion disc and spirals towards the neutron star.

As a result of this accretion process, most neutron star binaries continuously release large amounts of X-rays, which are punctuated by additional X-ray flashes every few hours or days.

Scientists can account for these 'type-I' bursts, in terms of nuclear reactions that are ignited in the inflowing gas -- mainly hydrogen - when it accumulates on the neutron star's surface.

But the Rapid Burster is a peculiar source: at its brightest, it does emit these type-I flashes, while during periods of lower X-ray emission, it exhibits the much more elusive 'type-II' bursts - these are sudden, erratic and extremely intense releases of X-rays.

"The Rapid Burster is the archetypal system to investigate type-II bursts - it's where they were first observed and the only source that shows both type-I and type-II bursts," said lead author Jakob van den Eijnden from Anton Pannekoek Institute for Astronomy in Amsterdam, The Netherlands.

Despite 40 years of searches, type-II bursts have been detected only in one other source besides the Rapid Burster. 

Known as the Bursting Pulsar and discovered in the 1990s, this binary system exhibits only type-II bursts.

Because of the scarcity of sources that display this phenomenon, the underlying physical mechanisms have long been debated, but the new study of the Rapid Burster could provide evidence for what is occurring.

New York, Feb 1 (IANS) Researchers have invented a hand-held breath monitor that can potentially detect flu virus and help prevent flu epidemics from spreading.

The device could eventually be available in drug stores so that people can be diagnosed quickly and take advantage of medicines used to treat the flu in its earliest stages. 

"I think that technology like this is going to revolutionise personalised diagnostics," said Perena Gouma, Professor at The University of Texas at Arlington in the US.

"This will allow people to be proactive and catch illnesses early and the technology can easily be used to detect other diseases such as Ebola virus disease, simply by changing the sensors," said Gouma, who has described her invention in the journal Sensors.

Gouma's device is similar to the breathalysers used by police officers when they suspect a driver to be under the influence of alcohol. 

A patient simply exhales into the device, which uses semiconductor sensors like those in a household carbon monoxide detector.

The difference is that these sensors are specific to the gas detected, yet still inexpensive, and can isolate biomarkers associated with the flu virus and indicate whether or not the patient has the flu. 

Researchers believe that the device may help prevent flu epidemics from spreading, protecting both individuals as well as the public health.

Gouma and her team relied on existing medical literature to determine the quantities of known biomarkers present in a person's breath when afflicted with a particular disease, then applied that knowledge to find a combination of sensors for those biomarkers that is accurate for detecting the flu. 

Gouma found that the breath monitor may detect the flu virus possibly as well as tests done in a doctor's office.

​New York, Feb 1 (IANS) Astronauts' brains compress and expand during spaceflight, show results of brain scans before and after space missions.

The researchers examined structural MRIs in 12 astronauts who spent two weeks as shuttle crew members, and 14 who spent six months on the International Space Station. 

All experienced increases and decreases in gray matter in different parts of the brain, with the changes more pronounced the longer the astronauts spent time in space, according to the study published in the journal Nature Microgravity.

"We found large regions of gray matter volume decreases, which could be related to redistribution of cerebrospinal fluid in space," said principal investigator Rachael Seidler, Professor at University of Michigan in the US.

"Gravity is not available to pull fluids down in the body, resulting in so-called puffy face in space. This may result in a shift of brain position or compression," Seidler noted.

The researchers also found increases in gray matter volume in regions that control leg movement and process sensory information from legs, which may reflect changes related to the brain learning how to move in microgravity. 

These changes were greater in space station astronauts because their brains were learning and adapting all the time. 

"It's interesting because even if you love something, you won't practice more than an hour a day," Seidler said. 

But the brain changes researchers observed were equivalent to someone practicing a new skill round-the-clock. 

"In space, it's an extreme example of neuroplasticity in the brain because you're in a microgravity environment 24 hours a day," Seidler said. 

Seidler said the brain changes could reflect new connections between neurons.

"The behaviour may return to normal, but the way the brain controls the behaviour may change," she said. 

The findings may lead to new ways of thinking about certain health conditions -- for example, people on long-duration bed rest or people who have normal pressure hydrocephalus, a condition in which cerebrospinal spinal fluid accumulates in ventricles in the brain and causes pressure. 

​New York, Feb 1 (IANS) Children exposed to complications shortly before or during birth are more likely to develop autism spectrum disorder (ASD), says a study.

The perinatal complications that had the highest association with ASD were birth asphyxia -- deprivation of oxygen during the birthing process -- and preeclampsia, a pregnancy complication characterised by high blood pressure and signs of damage to other organ systems, according to the study published in the American Journal of Perinatology.

Other perinatal complications that were associated with ASD included premature separation of the placenta from the uterus, breech/transverse fetal presentation, fetal dystocia/abnormal size or position, and a prolapsed/exposed umbilical cord.

For this study, researchers examined the electronic health records of 594,638 children born in Kaiser Permanente hospitals in Southern California between 1991 and 2009.

During this time, 6,255 of these children were diagnosed with autism spectrum disorder (ASD), 37 per cent of whom experienced perinatal complications. 

Researchers found that children exposed to complications during birth were at a 10 per cent increased risk of developing ASD, compared to children who did not experience perinatal complications.

That number rose to a 22 per cent increased risk of developing ASD for children exposed to complications before labour began. 

The study also showed that children exposed to complications both before and during birth had a 44 per cent greater risk of developing ASD than children who did not experience perinatal complications.

"Our study suggests that children exposed to certain perinatal complications, especially birth asphyxia and preeclampsia, were more likely to be diagnosed with ASD than those who were not exposed," said study lead author Darios Getahun from Kaiser Permanente Southern California Department of Research & Evaluation. 

"While there currently is no cure for ASD, early identification of children who may be at risk of developing the disorder is extremely important, as research shows that early intervention treatment services for children with ASD can greatly improve their development," Getahun noted.

​Kathmandu, Jan 31 (IANS) Nepal has geared up to develop a strong disaster response plan for major airports following the devastating earthquake in the country on April 2015.

Considering possible disasters in future, more than 30 officials from government agencies and airports, military and humanitarian partners and international experts were discussing the action plan at a four-day workshop which kicked off here on Tuesday, Xinhua news agency reported.

The event plans to assess and strengthen post-disaster preparedness and arrangements at two of Nepal's most strategic airports, the Tribhuwan International Airport (TIA) here and the one at Nepalgunj in the western part of the country.

Addressing the inaugural session, Tourism Secretary Shankar Prasad Adhikari said the disaster response capacity of TIA was not sufficient during the earthquake.

"We have to focus on further developing our airports' capacities," he said.

Being a landlocked country, Nepal relies heavily on air routes to transport aid supplies during emergency.

Right after the disaster that killed nearly 9,000 people, the country's only international airport was flooded with humanitarian aid supplies and rescue and relief teams coming from all around the world.

Large aircraft were unable to land at the airport as the runway was damaged from the influx of flights delivering aid.

Valerie Julliand, the UN Development Fund Resident Coordinator for Nepal, said: "We just can't wait for another disaster to strike to have a strong and effective contingency plans to manage the flow of emergency relief goods to the people in need. If Nepal really works on a good action plan, Nepal can transform its vulnerability of being landlocked into strength."

During the workshop, participants and trainers will evaluate the current level of preparedness at the two airports, go through trainings and provide concrete recommendations.

The workshop will also identify priorities for investment in national infrastructure that could further improve Nepal's resilience of emergency supply chains during a disaster. 

​Dubai, Jan 31 (IANS/WAM) The Dubai Health Authority (DHA) has announced plans to launch a new smart phone app to help users locate blood donation centres near them.

The app, to be launched in April, will enable potential donors to answer an eligibility questionnaire and read pre-donation advisory material on their mobile phones prior to visiting blood-donor centres.

"The new system and smart application will help streamline the blood donation process and provide a smart solution that allows donors to locate the nearest blood donation centre, or Mobile Blood Donation Unit, via their mobile phone," said Amani Al Jassmi, director of Information Technology at the DHA.

The app will also allow donors to receive appreciation letters, blood donation reminders and notifications of forthcoming blood donation campaigns.

Additionally, the app will store information of registered donors who agree to donate blood during emergencies and disasters and also reach out to them if the need arises.

May Raouf, director of the DHA Blood Donation Centre, said: "The aim of developing this app is to help the centre stay connected with all its donors, and provide both donors and potential donors with ease of use so that they are encouraged to donate blood and save lives."

​Bogota, Jan 31 (IANS) Colombia will host the 16th World Summit of Nobel Peace Laureates here on Thursday where 31 laureates will speak on peace, reconciliation and development, the media reported.

Colombian President Juan Manuel Santos will inaugurate the event, his office said.

The summit, organised by the Permanent Secretariat of the World Summit of Nobel Peace Laureates and the Bogota Chamber of Commerce, will end on February 5.

It is the first time the summit will be held in Latin America.

Earlier venues have been Barcelona (2015), Rome (2014), Warsaw (2013), Chicago (2012), Hiroshima (2010), Berlin (2009), Paris (2008) and Rome (1999 to 2007).

London, Jan 31 (IANS) A novel gene-editing method has been found to partially restore sight in rats bred with a hereditary condition called retinitis pigmentosa -- a condition that causes blindness in humans.

The researchers believe that the method could lead to new therapies for diseases of the eye, brain and heart.

Despite recent advances in editing targeted genes within cultured cells, editing genes within living organisms has remained elusive because current tools are inefficient. 

This is especially the case for non-dividing cells, which make up most adult tissues, including those of the brain, the pancreas, the eyes and the ears.

"For the first time, we have a method to edit the genome of non-dividing cells in the body. This could mean revolutionary new therapies for diseases of the eye, brain and heart," said study co-author Mo Li, Assistant Professor of Bioscience at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia.

Current gene-editing techniques typically use a natural DNA repair pathway, called homology-directed repair (HDR), to insert genetic material. 

However, this pathway is inefficient and not readily accessible in non-dividing cells. Another natural DNA repair pathway, called non-homologous end-joining (NHEJ), is more efficient in higher organisms and is active in non-dividing cells.

Studies have shown that NHEJ is error prone when used to turn off targeted genes but highly precise when used to insert DNA sequences into a gene. 

Until now, NHEJ had not been used for gene insertion in non-dividing cells, especially in tissues inside living adult animals.

So the research team developed a new technique called homology-independent targeted integration (HITI), which uses the gene-editing tool CRISPR-Cas9 to cut DNA at a specific location. The new genetic material is then inserted into the cut DNA using the NHEJ repair pathway.

The team found their method compared favourably to other gene-editing techniques, according to the study published in the journal Nature. 

"The new technology is considerably more efficient than existing methods," said Pierre Magistretti, Dean of the Biological and Environmental Science and Engineering Division at KAUST.

The researchers used the method for gene-replacement therapy in rats bred with a hereditary condition called retinitis pigmentosa. 

This condition causes blindness in humans and is caused by a mutation in the Mertk gene. 

The team aimed to restore Mertk function by inserting a copy of the missing DNA segment into the gene. 

Tests revealed partial restoration of sight, the study said.

London, Jan 31 (IANS) Repeated antibiotic treatment not only can increase bacteria's resistance to drugs but also help them reproduce faster than before, warns a new study.

The finding that growth of bacteria can be stimulated by antibiotics underlines the importance of using the right antibiotic on patients as soon as possible.

For the study, the researchers exposed E.coli bacteria to eight rounds of antibiotic treatment over four days and found the bug -- which can cause severe stomach pain, diarrhoea and kidney failure in humans -- had increased antibiotic resistance with each treatment.

This had been expected, but researchers were surprised to find mutated E.coli reproduced faster than before encountering the drugs and formed populations that were three times larger because of the mutations.

This was only seen in bacteria exposed to antibiotics -- and when researchers took the drug away, the evolutionary changes were not undone and the new-found abilities remained, said the study published in the journal Nature Ecology & Evolution.

"Our research suggests there could be added benefits for E.coli bacteria when they evolve resistance to clinical levels of antibiotics," said lead author Robert Beardmore, Professor at University of Exeter in Britain.

"It's often said that Darwinian evolution is slow, but nothing could be further from the truth, particularly when bacteria are exposed to antibiotics," Beardmore said.

"Bacteria have a remarkable ability to rearrange their DNA and this can stop drugs working, sometimes in a matter of days," Beardmore explained. 

The researchers tested the effects of the antibiotic doxycycline on E.coli as part of a study of DNA changes brought about by antibiotics.

"It is said by some that drug resistance evolution doesn't take place at high dosages but our paper shows that it can and that bacteria can change in ways that would not be beneficial for the treatment of certain types of infection," Mark Hewlett, also of the University of Exeter, pointed out.

"This shows it's important to use the right antibiotic on patients as soon as possible so we don't see adaptations like these in the clinic," Hewlett noted.

​London, Jan 31 (IANS) There has been no improvement since 1998 in survival rates for heart failure patients, a new study has found.

Researchers from the University of Oxford looked at routinely collected medical records from 54,313 patients with heart failure and found 81.3 per cent survived for one year, 51.5 per cent survived for two years, and 29.5 per cent survived for 10 years, following diagnosis with the condition.

"Getting an accurate estimate of heart failure prognosis is vital for those who commission healthcare services, so resources can be allocated appropriately," said Clare Taylor, a primary care researcher at the University of Oxford.

Survival rates, between 1998 and 2012, for people aged over 45 with heart failure showed no improvement though, in contrast to cancer survival rates in the Britain which have doubled in the last 40 years.

"Perhaps more importantly, this allows patients to make more informed choices about treatments and possible end-of-life care. While the survival rates were better than other studies, we disappointingly did not see any improvement over time," added Taylor.

According to the study published in the journal Family Practice, heart failure is a common long-term condition affecting around nine lakh in the Britain and represents the second highest cost to the National Health Service for any disease after stroke.

"An estimated one to two in every 100 adults in the west currently live with the condition," the study noted.

The paper found that survival rate estimates vary depending on a person's age, gender, other health conditions and blood pressure.