Knowledge Update

​New York, Jan 12 (IANS) When a star comes close to the black hole only to be ripped apart, the outward gas streamer gathers itself into planet-size objects which are then flung across the galaxy in a game of cosmic 'spitball', new research has revealed.

The team from Harvard University noted that the closest of these planet-mass objects might be within a few hundred light-years of Earth with a weight somewhere between Neptune and several Jupiters.

"A single shredded star can form hundreds of these planet-mass objects. We wondered: Where do they end up? How close do they come to us? We developed a computer code to answer those questions," said lead author Eden Girma.

These planet-size objects glow from the heat of its formation and are very different from a typical planet because they made of star-stuff.

"It takes only a day for the black hole to shred the star and only about a year for the resulting fragments to pull themselves back together," said the study presented at the conference of American Astronomical Society recently.

Almost 95 per cent of the planet-mass objects will leave the galaxy entirely due to their speeds of about 10,000 km per second. It would take about a million years for one of these objects to reach Earth's neighborhood. 

"Since most other galaxies also have giant black holes at their cores, it is likely that the same process is at work in them," Girma added.

New York, Jan 11 (IANS) Contrary to the common perception that people who post frequent selfies on social media platforms are generally narcissists, a new study now says selfie lovers may have different motives which often extend beyond self-obsession and showing off.

After analysing their survey results and interviews, a team of researchers from Texas Tech University found that there are three categories of selfie-takers -- communicators, autobiographers and self-publicists.

"It is important to recognise that not everyone is a narcissist," said Steven Holiday, study co-author in a paper published in the journal Visual Communication Quarterly.

Communicators are those who post selfies on social media such as Facebook and Instagram primarily to engage with their friends, family or followers in a conversation.

"They are all about two-way communication," added team member Maureen "Mo" Elinzano.

Autobiographers use selfies on social media platform as a tool to record key events in their lives and preserve significant memories. 

Lastly, self-publicists are the people who love documenting their entire lives.

"Identifying and categorising the three groups is important because it's a different kind of photography than we have ever experienced before," Holiday added.

Understanding people's motives can be valuable, because years from now, our society's visual history is going to be largely comprised of selfies. 

"And to find out why people do it, that contributes a lot to the discussion on selfies and visual communication in general," added Matt Lewis, co-author.

Sydney/Kolkata, Jan 11 (IANS) Think twice before blaming the weather gods for achy joints as researchers now claim that the weather plays no part in the symptoms associated with either back pain or osteoarthritis.

A new research from The George Institute for Global Health has debunked beliefs that episodes of both back pain and arthritis can be triggered by changes in the weather, including temperature, humidity, air pressure, wind direction and precipitation.

"The belief that pain and inclement weather are linked dates back to Roman times. But our research suggests this belief may be based on the fact that people recall events that confirm their pre-existing views," said Chris Maher, of the institute.

"Human beings are very susceptible so it is easy to see why we might only take note of pain on the days when it is cold and rainy outside, but discount the days when they have symptoms but the weather is mild and sunny," he added.

The studies were carried out across Australia with average daily temperatures ranging from 5.4 degrees Celsius to 32.8 degrees Celsius.

Almost 1,000 people with lower back pain, and around 350 with knee osteoarthritis were recruited for the Australia-based studies.

Weather data from the Australian Bureau of Meteorology were sourced for the duration of the study period.

Results showed no association between back pain and temperature, humidity, air pressure, wind direction or precipitation.

However, higher temperatures did slightly increase the chances of lower back pain, but the amount of the increase was not clinically important.

Back pain affects up to a third of the world's population at any one time, while almost 10 per cent of men and 18 per cent of women over the age of 60 have osteoarthritis.

Manuela Ferreira, who led the osteoarthritis research at the institute, said: "People who suffer from either of these conditions should not focus on the weather as it does not have an important influence on your symptoms and it is outside your control."

Washington, Jan 11 (IANS) Charon -- Pluto's moon which is more than half its diameter and orbits only 12,000 or so miles away -- is slowing down the decay of Pluto's atmosphere, scientists have found.

To put that into perspective, picture our moon three times closer to Earth and as large as Mars.

A new study from the Georgia Institute of Technology has provided additional insight into this relationship and how it affects the continuous stripping of Pluto's atmosphere by solar wind. 

When Charon is positioned between the Sun and Pluto, the research indicates that the moon can significantly reduce atmospheric loss.

"Charon doesn't always have its own atmosphere. But when it does, it creates a shield for Pluto and redirects much of the solar wind around and away," said Carol Paty, associate professor in the school of earth and atmospheric sciences.

This barrier creates a more acute angle of Pluto's bow shock, slowing down the deterioration of the atmosphere. 

When Charon doesn't have an atmosphere, or when it's behind or next to Pluto (a term scientists call "downstream"), then Charon has only a minor effect on the interaction of the solar wind with Pluto.

The study's predictions, performed before the New Horizons probe collected and returned data to Earth, is consistent with the measurements made by the spacecraft about Pluto's atmospheric loss rate. 

The research was published in a special Pluto issue of the journal Icarus.

London, Jan 11 (IANS) In a first, Danish researchers including one of Indian origin, have engineered E. coli bacteria to develop a cell line that produces large quantities of the compound serine -- used in detergents, tube feeding formula and as building blocks for many key chemicals.

The researchers from The Novo Nordisk Foundation Center for Biosustainability (DTU Biosustain) believe this cell line will help produce the ingredients sustainably and at low cost. 

"This discovery is quite unique and proves that we can actually adapt cells to tolerate large amounts of serine -- something many people thought wasn't possible," said Professor Alex Toftgaard Nielsen from DTU Biosustain. 

In order to develop these cells, the team used highly specialised robots.

"Cell growth must be monitored 24 hours a day, and the cells must be transferred to new medium at a certain time of growth. Therefore, it is crucial that we use 'Adaptive Laboratory Evolution' (ALE) robots," explained lead author Hemanshu Mundhada from Technical University of Denmark.

Serine is an amino acid important for humans because it is one of the 20 amino acids forming proteins in our bodies. 

Being highly water soluble, serine finds application as moisturiser in lotions of pharma and cosmetic industry.

The first step in the development process was to produce E. coli cells that could survive high concentrations of serine. 

To achieve this, the scientists used ALE method in which they first exposed the cells to a small amount of serine. When the cells had grown accustomed to these conditions, the bacteria were transferred to a slightly higher concentration. 

The experiment was repeated several times with the cells best suited to tolerate serine.

The tolerant E. coli cells were subsequently optimised genetically to produce serine.

"We have shown that our E coli cells can use regular sugar and even residues from sugar production, molasses, in lower concentrations. We have seen promising results with less expensive sugars, which makes it even more attractive to produce serine in E. coli," Mundhada added in a paper published in the journal Metabolic Engineering.

Sydney, Jan 10 (IANS) A drug that could "melt away" cancer cells has been approved for human use in Australia, a media report said on Tuesday.

Developed in Melbourne, Venetoclax, which will be sold as Venclexta, has been approved by the Therapeutic Goods Administration (TGA) for use by patients with advanced forms of chronic lymphocytic leukaemia, Xinhua news agency reported.

The drug, which was approved for use in the US in August 2016, would be made available to patients who have not responded to standard treatments or who have not been able to undergo other therapies.

Venetoclax works by blocking the action of the BCL-2 protein which enables cancer cells to survive, a solution that researchers worldwide have been studying for more than 30 years.

Doug Hilton, the director at the Walter and Eliza Hall Institute of Medical Research, said the approval was important for patients with limited options.

"Like a lethal arrow, Venetoclax flies straight to the heart of BCL-2," Hilton told the Australian Broadcasting Corporation (ABC).

David Huang, the developer of the drug from the Walter and Eliza Hall Institute of Medical Research, won the Eureka Prize for Innovation in Medical Research in 2016. 

London, Jan 10 (IANS) Retroviruses, the family of viruses that includes HIV, are almost half a billion years old -- several hundred million years older than previously thought, claim scientists from Oxford University.

New research suggests that retroviruses have ancient marine origins, having been with their animal hosts through the evolutionary transition from sea to land.

Until now, it was thought that retroviruses were relative newcomers -- possibly as recent as 100 million years in age.

"Our research shows that retroviruses are at least 450 million years old, if not older, and that they must have originated together with, if not before, their vertebrate hosts in the early Paleozoic era," explained Dr Aris Katzourakis from Oxford University's department of zoology.

Furthermore, they would have been present in our vertebrate ancestors prior to the colonisation of land and have accompanied their hosts throughout this transition from sea to land, all the way up until the present day.

Retroviruses are a family of viruses that includes the HIV virus responsible for the AIDS pandemic. 

They can also cause cancers and immunodeficiencies in a range of animals. 

The 'retro' part of their name comes from the fact they are made of RNA, which they can convert into DNA and insert into their host genome.

In this study, the researchers unearthed genomic fossils for foamy-like retroviruses in highly diverse hosts, including ray-finned fish and amphibians in which they had not previously been found.

"We need to consider the adaptations that vertebrates have developed to combat viruses, and the corresponding viral countermeasures, as the product of a continuous arms race that stretches back hundreds of millions of years," Katzourakis noted in the journal Nature Communications.

The findings will help researchers understand more about the continuing 'arms race' between viruses and their hosts.

​Tel Aviv, Jan 10 (IANS) A team of Israeli researchers has developed a smartphone-based system to assess obstructive sleep apnea (OSA) severity while a patient is awake and analyse the sleep-wake activity.

Currently, patients are diagnosed using polysomnography (PSG) to record brain waves, blood oxygen level, heart rate, breathing and eye and leg movements overnight. 

The new system, which does not require contact sensors, can be installed onto a smartphone or other device that utilises ambient microphones. 

It both analyses speech while the user is awake and records and evaluates overnight breathing sounds using new technology that is simpler to use and significantly less expensive than PSG, said the team from Ben-Gurion University of the Negev (BGU).

"We've developed technology that could help diagnose OSA and sleep disorders in a convenient way," said Dr Yaniv Zigel, head of BGU's biomedical signal processing research lab (BSP) in a statement.

"The audio-analysis application can record speech signals from awake subjects. Now, we will be able to get a fast, OSA severity estimation without an overnight sleep study," added professor Ariel Tarasiuk, head of the sleep-wake disorders unit at Soroka University Medical Center in Beer-Sheva. 

Researchers tested the new speech and breathing sound analysis systems on more than 350 subjects, along with PSG, in laboratory and at-home settings. 

They were able to reliably evaluate sleep quality parameters such as sleep-wake activity, snoring severity and OSA using this system.

"We are excited about this non-contact sleep tracking system which does not require patients to wear uncomfortable monitoring equipment on their body," Tarasiuk added. 

The application can also be very useful for CPAP (continuous positive airway pressure) machine users who want to check the effectiveness of their sleep apnea therapy.

Abu Dhabi, Jan 10 (IANS/WAM) The Food and Agriculture Organisation (FAO) of the United Nations has lauded the decision of UAE Vice President and Prime Minister and Ruler of Dubai, Sheikh Mohammed bin Rashid Al Maktoum, to fight hunger and food waste by launching the Food Bank initiative.

Nabil Gangi, FAO Representative to the UAE, said the initiative "reflects the true spirit of giving, which has always characterised the UAE communities, and the vision of the founder of the country, late Sheikh Zayed bin Sultan Al Nahyan".

Gangi praised the initiative to turn Dubai into the first city in the region, and probably in the world, to achieve zero food waste. 

He also confirmed the FAO's readiness to continue working hand-in-hand with the United Arab Emirates government and stakeholders to ensure the success of the initiative within a sustainable food diversification strategy.

The newly-established UAE Food Bank will bring together several stakeholders to collect excess food from hotels, supermarkets, restaurants and farms. 

It will then store and package the food for distribution, while the inedible food will be recycled for different usage, including but not limited to, animal feed and fertilisers.