Knowledge Update

​London, May 10 (IANS) An international team of astrophysicists has detected an intense wind from one of the closest known black holes to the Earth.

The team led by professor Phil Charles from the University of Southampton observed "V404 Cygni" which went into a bright and violent outburst in June 2015 after more than 25 years of quiescence.

They began taking optical measurements of the black hole's accretion disc using the Gran Telescopio CANARIAS (GTC) - the biggest optical-infrared telescope in the world in the Canary Islands.

The results show the presence of a wind of neutral material (unionised hydrogen and helium), which is formed in the outer layers of the accretion disc, regulating the accretion of material by the black hole.

This wind, detected for the first time in a system of this type, has a very high velocity (3,000 kms per second) so that it can escape from the gravitational field around the black hole.

“Its presence allows us to explain why the outburst, in spite of being bright and very violent, with continuous changes in luminosity and ejections of mass in the form of jets, was also very brief, lasting only two weeks,” explained professor Charles.

“V404 Cygni” is a black hole within a binary system located in the constellation of Cygnus. At only 8,000 light years away, it is one of the closest known black holes to the Earth and has a particularly large accretion disc (with a radius of about 10 million kms), making its outbursts especially bright at all wavelengths (X-rays, visible, infrared and radio waves).

The observations also revealed the presence of a nebula formed from material expelled by the wind.

This phenomenon, which has been observed for the first time in a black hole, also allows scientists to estimate the quantity of mass ejected into the interstellar medium.

“This outburst of 'V404 Cygni' will help us understand how black holes swallow material via their accretion discs,” noted Teo Muñoz Darias, researcher at the Instituto de Astrofísica de Canarias (IAC) in a paper published in the journal Nature.​

New York, May 10 (IANS) An experimental malaria vaccine has been found to protect a small number of healthy people from infection for more than one year after immunisation, says a study.

The vaccine, known as the PfSPZ Vaccine, was developed and produced by US-based biotechnology firm Sanaria.

"It is now clear that administering the PfSPZ Vaccine intravenously confers long-term, sterile protection in a small number of participants, which has not been achieved with other current vaccine approaches," said principal investigator of the trial Robert Seder from National Institute of Allergy and Infectious Diseases (NIAID), part of the US National Institutes of Health.

NIAID researchers and collaborators at the University of Maryland School of Medicine in Baltimore conducted the clinical evaluation of the vaccine, which involved immunisation and exposing willing healthy adults to the malaria-causing parasite Plasmodium falciparum (P. falciparum) in a controlled setting.

The parasites that cause malaria are transmitted to humans through the bite of an infected mosquito. 

The PfSPZ Vaccine is composed of live, but weakened P. falciparum sporozoites -- the early developmental form of the parasite.

Previous research showed the PfSPZ Vaccine to be highly protective three weeks after immunisation. In this trial, researchers assessed if protection could last for five months to a year.

For the phase one clinical trial, the researchers enrolled 101 healthy adults aged 18 to 45 years who had never had malaria. 

Of these volunteers, 59 received the vaccine and 32 participants served as controls and were not vaccinated. 

Vaccine recipients were divided into several groups to assess the roles of the route of administration, dose, and number of immunisations in conferring short- and long-term protection against malaria.

To evaluate how well the vaccine prevented malaria infection, all participants - including the control participants who were not vaccinated - were exposed at varying times to the bites of mosquitoes carrying the same P. falciparum strain from which the vaccine was derived. 

The researchers found that the vaccine provided malaria protection for more than one year in 55 percent of people without prior malaria infection. 

The findings were published in the journal Nature Medicine.

In those individuals, the vaccine appeared to confer sterile protection, meaning the individuals would be protected against disease and could not further transmit malaria. 

The vaccinations were also well-tolerated among participants, and there were no serious adverse events attributed to vaccination, said the study.​

Washington, May 10 (IANS) Presence of warm water in the Pacific Ocean due to a stalled El Nino in 2014 stacked the deck for a monstrous version of the warming climate cycle to occur in 2015, a study says.

Easterly winds in the tropical Pacific Ocean stalled a potential El Nino in 2014 and left a swath of warm water in the central Pacific. This left over warm water gave the current El Nino a head start, the researchers explained.

El Nino and La Nina are the warm and cool phases of a recurring climate pattern across the tropical Pacific Ocean called the El Nino-Southern Oscillation, or ENSO. 

The warm and cool phases shift back and forth every two to seven years, and each phase triggers predictable disruptions in temperature, wind, and rain across the globe. 

During El Nino events, water temperatures at the sea surface are higher than normal. Low-level surface winds, which normally blow east to west along the equator, or easterly winds, start blowing the other direction, west to east, or westerly.

In the spring of 2014, strong westerly winds near the equator in the western and central Pacific Ocean created a buzz among scientists - they saw the winds as a sign of a large El Nino event to come in the winter of 2014, said lead author of the study Aaron Levine, a climate scientist at US National Oceanic and Atmospheric Administration (NOAA) Pacific Marine Environmental Laboratory in Seattle, Washington.

But as the summer progressed, El Niño did not form the way scientists expected it to. Sea surface temperatures in the eastern Pacific never warmed enough to truly be called an El Nino, and the buzz fizzled out.

But then, in the spring of 2015, episodes of very strong westerly wind bursts occurred and became more frequent throughout the summer. 

Following a pattern set by previous large El Ninos, 2015 to 2016 became one of the three strongest El Ninos on record, along with 1982 to 1983 and 1997 to 1998, Levine said.

The findings will be published in a forthcoming issue of the journal Geophysical Research Letters.

​Washington, May 10 (IANS) Turning the traditional knowledge on its head that young Earth had a thicker atmosphere, scientists, including an Indian-origin researcher, have found that air at that time exerted at most half the pressure of today's atmosphere.

The new finding reverses the commonly accepted idea that the early Earth had a thicker atmosphere to compensate for weaker sunlight.

The finding also has implications for which gases were in that atmosphere and how biology and climate worked on the early planet.

"For the longest time, people have been thinking the atmospheric pressure might have been higher back then, because the sun was fainter," said lead author Sanjoy Som, who did the work as part of his doctorate in earth and space sciences at University of Washington.

The team used bubbles trapped in 2.7 billion-year-old rocks to reach this conclusion.

"Our result is the opposite of what we were expecting," he added in a paper published in the journal Nature Geoscience.
Som is currently doing astrobiology research at NASA's Ames Research Centre in California.

The idea of using bubbles trapped in cooling lava as a "paleobarometer" to determine the weight of air in our planet's youth occurred decades ago to co-author Roger Buick, professor of earth and space sciences.

A potential site in western Australia was discovered by co-author Tim Blake of University of western Australia.

There, the Beasley River has exposed 2.7 billion-year-old basalt lava.

A stream of molten rock quickly cools from top and bottom, and bubbles trapped at the bottom are smaller than those at the top.

The size difference records the air pressure pushing down on the lava as it cooled, 2.7 billion years ago.

Rough measurements in the field suggested a surprisingly lightweight atmosphere.

More rigorous x-ray scans from several lava flows confirmed the result: The bubbles indicate that the atmospheric pressure at that time was less than half of today's.

Earth 2.7 billion years ago was home only to single-celled microbes, sunlight was about one-fifth weaker and the atmosphere contained no oxygen.

But this finding points to conditions being even more otherworldly than previously thought.

A lighter atmosphere could affect wind strength and other climate patterns and would even alter the boiling point of liquids.

Other geological evidence clearly shows liquid water on Earth at that time so the early atmosphere must have contained more heat-trapping greenhouse gases like methane and carbon dioxide and less nitrogen.

The result also reinforces Buick's 2015 finding that microbes were pulling nitrogen out of Earth's atmosphere some three billion years ago.

"People will need to rewrite the textbooks," the authors noted.

The researchers will now look for other suitable rocks to confirm the findings and learn how atmospheric pressure might have varied through time.​

London, May 10 (IANS) In a finding that could change the way the most common form of stroke is treated globally, researchers have shown that modified dosage of a clot-busting drug can reduce risk of serious bleeding in the brain and improve survival rates.

Intravenous rtPA (or alteplase) is given to people suffering acute ischaemic stroke and works by breaking up clots blocking the flow of blood to the brain.

However, it can cause serious bleeding in the brain in around five per cent of cases, with many of these proving fatal.

Compared to standard dose (0.9mg/kg body weight), the lower dose (0.6mg/kg) of rtPA reduced rates of serious bleeding in the brain, known as intracerebral haemorrhage (ICH), by two thirds, showed the results of the trial of more than 3,000 patients in 100 hospitals worldwide.

"Most patients who have a major stroke want to know they will survive but without being seriously dependent on their family. We have shown this to be the case with the lower dose of the drug,” said one of the researchers Tom Robinson, professor at University of Leicester in Britain.

The findings were published in the New England Journal of Medicine.

"At the moment you could have a stroke but end up dying from a bleed in the brain. It's largely unpredictable as to who will respond and who is at risk with rtPA,” lead author of the study Craig Anderson, professor at Sydney Medical School, University of Sydney in Australia.

"What we have shown is that if we reduce the dose level, we maintain most of the clot busting benefits of the higher dose but with significantly less major bleeds and improved survival rates. On a global scale, this approach could save the lives of many tens of thousands of people,” Anderson noted.​

​New York, May 6 (IANS) Although India managed to counter a steep decline in its vulture population in mid-1990s, these efficient scavengers are in danger of disappearing in many parts of the world primarily due to the presence of toxins in the carrion they consume.

Poisoning is the greatest extinction risk facing vultures, and impacts 88 percent of threatened vulture species, the study said.

Now, the center of the vulture crisis is in sub-Saharan Africa, the researchers noted.

In the mid-1990s India experienced a precipitous vulture decline, with more than 95 percent of vultures disappearing by the early 2000s. 

"That was a massive collapse that led a lot of people to really focus more attention on vultures," said one of the researchers Evan Buechley from University of Utah in the US.

The cause was eventually traced to diclofenac, a veterinary anti-inflammatory drug that relieved pain in cattle, but proved highly toxic to vultures. 

Hundreds of vultures would flock to each cattle carcass. And if the cow had recently been treated with diclofenac, hundreds of vultures would die. 

Because of this highly gregarious feeding behaviour, less than one percent of cattle carcasses contaminated with diclofenac could account for the steep vulture decline. 

Fortunately, international cooperation led to a total ban on veterinary diclofenac use. 

The numbers of vultures have stabilised, and are now showing signs of slowly increasing, Buechley said.

Losses of vultures can allow other scavengers to flourish, Buechley pointed out in a report published in the journa Biological Conservation.

For example, following the decline of vultures, India experienced a strong uptick in feral dogs --by an estimated seven million. 

The increase in dogs, potentially feeding on disease-ridden carcasses, is thought to have at least partially caused the rabies outbreak that was estimated to have killed 48,000 people from 1992-2006 in India -- deaths that may have been avoided if not for the disappearance of vultures.

Members of the Parsi sect of Zoroastrianism experienced a different impact. For thousands of years, the Parsi people have placed their dead on exposed mountaintops or tall towers for vultures to consume. The practice is called "sky burial."

But with few vultures and unable to properly handle their dead, the Parsis experienced a crisis within the faith. ​

Some constructed captive vulture aviaries. Others talked about desiccating bodies using focused solar mirrors. The Parsis' plight exemplifies the vultures' role in south Asian society -- and the various impacts if the vultures are not there.

Although the vulture crisis in Africa is ongoing, the researchers can predict what the outcome will be, based on previous experiences in India. 

Crows, gulls, rats and dogs will boom. And the rabies outbreak in India may just be a prologue, because several sub-Saharan Africa countries already have the highest per-capita rabies infection rates in the world, the researchers noted.

​New York, May 6 (IANS) Researchers have developed a miniature camera that can be mounted onto the eyeglasses of people who are legally blind -- vision with 20/200 or worse in the better eye -- and dramatically improve their ability to read an email or a newspaper article.

Made using optical character-recognition technology, the artificial vision device can be easily mounted onto the eyeglasses and works either by pointing at an item, tapping on it, or pressing a trigger button.



A wire attaches the device to a small pack containing its battery and computer. It recognises text and reads it to the user using an earpiece that transmits sound, and can also be programmed to recognise faces and commercial products.

The camera device offers hope to patients with age-related macular degeneration -- leading cause of permanent impairment of reading and fine or close-up vision in the elderly -- who are beyond medical or surgical therapy for the condition, researchers said.

“The device offers new hope for the large and growing number of individuals with age-related macular degeneration or advanced-stage glaucoma, two of the leading causes of vision loss among the elderly,” said one of the researchers Mark Mannis, professor at University of California in the US.

The device, which can be carried, fit into a pocket or attached to a belt, can also help older adults who are struggling with vision loss to better perform daily activities and could potentially bring greater independence, the researchers added in the paper published online in the journal JAMA Ophthalmology.

The team conducted a pilot study and analysed 12 participants with low vision, six men and six women, with an average age of 62. 

Using the device, the study participants were significantly better able to perform activities of daily living. 

"Our results show that it can be a very useful aid for patients with low vision in performing activities of daily living, and increase their functional independence," said another researcher Elad Moisseiev.​

​Washington, May 7 (IANS) Scientists have detected atomic oxygen in the Martian atmosphere for the first time since the last observation 40 years ago.

Atomic oxygen -- an elemental form of oxygen that does not exist in Earth's atmosphere -- affects how other gases escape Mars and therefore has a significant impact on the planet's atmosphere. 

An instrument onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA) - a joint project of NASA and the German Aerospace Center - helped detect these atoms in the upper layers of the Martian atmosphere known as the mesosphere, NASA said in a statement.

"Atomic oxygen in the Martian atmosphere is notoriously difficult to measure," said SOFIA project scientist Pamela Marcum. 

"To observe the far-infrared wavelengths needed to detect atomic oxygen, researchers must be above the majority of Earth’s atmosphere and use highly sensitive instruments, in this case a spectrometer. SOFIA provides both capabilities," Marcum noted.

The scientists could detect only about half the amount of oxygen expected, which may be due to variations in the Martian atmosphere. 

The Viking and Mariner missions of the 1970s made the last measurements of atomic oxygen in the Martian atmosphere. 

These more recent observations were possible thanks to SOFIA’s airborne location, flying between 37,000-45,000 feet, above most of the infrared-blocking moisture in Earth’s atmosphere, NASA said.

The advanced detectors on one of the observatory’s instruments, the German Receiver for Astronomy at Terahertz Frequencies (GREAT), enabled astronomers to distinguish the oxygen in the Martian atmosphere from oxygen in Earth’s atmosphere.

The findings were presented in a paper published in the journal Astronomy and Astrophysics.

SOFIA is a Boeing 747SP jetliner modified to carry a 100-inch diametre telescope.​

​London, May 7 (IANS) Most people feel that friendship is a two-way street, but only half of your buddies would actually consider you their friend, a study has found, adding that this limits their ability to influence them and further impacts on human behaviour.

Companies and social groups that depend on social influence for collective action, information dissemination and product promotion could improve their strategies and interventions.

"It turns out that we're very bad at judging who our friends are and difficulty in determining the reciprocity of friendship significantly limits our ability to engage in cooperative arrangements," said Erez Shmueli from Tel Aviv University.

“We learned that we can't rely on our instincts or intuition. There must be an objective way to measure these relationships and quantify their impact," Shmueli added in a paper published in the journal PLoS One.

The team conducted extensive social experiments and examined six friendship surveys from some 600 students in Israel, Europe and the United States to assess friendship levels and expectations of reciprocity.

They then developed an algorithm that examines several objective features of a perceived friendship -- the number of common friends or the total number of friends and then distinguish between unidirectional and reciprocal.

The findings showed that 95 percent of participants think that their relationships were reciprocal.

"If you think someone is your friend, you expect him to feel the same way. But in fact that's not the case -- only 50 percent of those polled matched up in the bidirectional friendship category."

"Reciprocal relationships are important because of social influence as influence is the name of the game," Shmueli stated.​

New York, May 7 (IANS) Researchers have developed a new antibody-based drug that has the potential to slow down the replication of the human immunodeficiency virus (HIV) in the body and may also provide a better strategy for long-term control of the deadly infection.

Anti-retroviral therapy -- a combination of drugs that slows the replication of HIV in the body -- currently used to treat HIV has drawbacks. If a person discontinues his or her treatment, even missing a few doses, the level of the virus in the body is able to rebound quickly.

In the antibody therapy, the researchers used 3BNC117 -- a molecule -- also called as a broadly neutralising antibody because it has the ability to fight a wide range of HIV strains.

The findings of the first clinical trial showed that using the antibody could greatly reduce the amount of virus that is present in an individual's blood.

"This study provides evidence that a single dose of an antibody stimulates patients' immune response, enabling them to make new or better antibodies against the virus," said lead author Till Schoofs, postdoctoral fellow at The Rockefeller University in the US. 

For the study, published in the journal Science, the team included 15 patients, in the clinical trial, who had high levels of the virus in their blood, and 12 other patients whose virus levels were being controlled with antiretroviral therapy (ART). 

The patients were infused with a single dose of 3BNC117 and were monitored over a six-month period.

In 14 out of 15 patients who had higher levels of the virus at the time they were given the antibody were seen making new antibodies that could neutralise a number of different strains of HIV.

It usually takes several years for the body to begin to make good antibodies against HIV. So there might be an even better effect later on, especially if patients are given more than one dose of 3BNC117, the researchers added.

To determine further benefits of treatment with 3BNC117, the researchers conducted another study, also published in the journal Science, in a mouse model. 

The results revealed that 3BNC117 was able to engage the animals' immune cells and accelerate their clearance of HIV-infected cells. 

"This shows that the antibody not only can exert pressure on the virus, but also can shorten the survival of infected cells," first author of the study Ching-Lan Lu, doctoral student at The Rockefeller University, noted. 

Further, the researchers plan to test 3BNC117 in combination with other antibodies that target HIV, to determine whether an even stronger antiviral effect can be found.