Knowledge Update

London, April 11 (IANS) Ancestors of modern-day humans are thought to have wiped out the ancient Neanderthals from Europe by passing on diseases and infections when they moved out of Africa and into the continent previously dominated by them.

The Neanderthals, who would only have developed resistance to the diseases of their European environment, are most likely to have been infected with a bacterium that causes stomach ulcers, the virus that causes genital herpes, tapeworms and tuberculosis.

The researchers said that some infectious diseases are likely to be many thousands of years older than previously believed.

The diseases and infections to which the hunter-gatherers were exposed would have made them less able to find enough food and remain healthy. The diseases would have spread through sexual contact between the two species.

"Humans migrating out of Africa would have been a significant reservoir of tropical diseases," said Charlotte Houldcroft from the University of Cambridge in Britain.

"For the Neanderthal population of Eurasia, adapted to that geographical infectious disease environment, exposure to new pathogens carried out of Africa may have been catastrophic," Houldcroft added.

The findings showed Helicobacter pylori -- a bacterium that causes stomach ulcers -- as highly likely to have been passed by humans to Neanderthals. 

It is estimated to have first infected humans in Africa between 88,000 to 116,000 years ago, and in Europe 52,000 years ago.

Another likely candidate is herpes simplex 2 -- the virus that causes genital herpes. Evidence in the genome of this disease suggested that it was transmitted to humans in Africa 1.6 million years ago from another, currently unknown hominin species that in turn acquired it from chimpanzees.

The researchers have challenged the view that the spread of infectious diseases exploded with the evolution of agriculture about 8,000 years ago, which saw denser and more settled human populations coexisting with livestock.

Instead, genetic data showed that many infectious diseases have been "co-evolving with humans and our ancestors for tens of thousands to millions of years, and passed from them to the animals,” the researchers noted in the paper published in the American Journal of Physical Anthropology.

"Hunter-gatherers lived in small foraging groups. Neanderthals lived in groups of between 15-30 members, for example. So disease would have broken out sporadically, but have been unable to spread very far. Once agriculture came along, these diseases had the perfect conditions to explode, but they were already around,” Houldcroft maintained.

Recent theories for the cause of Neanderthal extinction range from climate change to an early human alliance with wolves resulting in domination of the food chain.

"It is probable that a combination of factors caused the demise of Neanderthals and the evidence is building that spread of disease was an important one," Houldcroft concluded.​

​London, April 11 (IANS) Assessing the relationship between gender, BMI and notion of 'attractiveness', a new study finds that weight is intrinsically linked to attractiveness and women are the harshest judges and most harshly judged.

The findings showed that females perceive men and women with higher body mass index (BMI) as less attractive and judge other women harshly about weight in relation to beauty.

Conversely, men do not judge another man with a higher weight negatively, but still see overweight women as less attractive.

"This is the first study that looks at the relationship between BMI and attractiveness, from both gender's perspective" explained Sonia Oreffice, professor of University of Surrey in Britain.

Further, the anthropometric attributes -- physical measures of a person's size, form, and functional capacities, play a significant role in wage regressions in addition to attractiveness, showing that body size cannot be dismissed as a simple component of beauty.

The study, published in the journal Economics and Human Biology, provides insight into the relationship between body size and beauty and the wage inequality associated with it.

Body size -- height for both men and women and BMI only for men -- explains wages above and beyond beauty.

This contributes to bridge the gap between studies on the economics of anthropometric measures (including height and BMI), on one hand, and the economics of beauty, on the other, estimating the relevance of body size and beauty, the researchers concluded.​

​London, April 11 (IANS) Using data from NASA's Kepler space telescope, astrophysicists from the University of Birmingham have discovered extra-solar planets whose atmospheres have been stripped away by their host stars.

According to them, planets with gaseous atmospheres that lie very close to their host stars are bombarded by a torrent of high-energy radiation. 

Due to their proximity to the star, the heat that the planets suffer means that their "envelopes" have been blown away by intense radiation. 

This violent "stripping" occurs in planets that are made up of a rocky core with a gaseous outer layer.

"The results show that planets of a certain size that lie close to their stars are likely to have been much larger at the beginning of their lives. Those planets will have looked very different," said Dr Guy Davies from the University of Birmingham's school of physics and astronomy. 

The findings have important implications for understanding how stellar systems, like our own solar system, and their planets, evolve over time and the crucial role played by the host star.

Scientists expect to discover many such "stripped systems" using a new generation of satellites including the NASA TESS Mission which will be launched next year. 

The paper was published in the journal Nature Communications. ​

​London, April 11 (IANS) How to determine that a person is trustworthy? According to researchers, people who hold onto moral absolutes are more trusted and more valued as social partners, suggesting that people gauge others' trustworthiness based on their moral judgments.

The findings help explain that snap judgements about morality tend to be based on a set of absolute moral rules even if a person makes different decisions when given more time.

"If people who stick to moral absolutes are preferred as social partners, expressing this view will reap benefits for oneself," said lead researcher Jim AC Everett from the University of Oxford.

The team used several variations of moral dilemmas where a person must decide whether or not to sacrifice an innocent person in order to save the lives of many others. 

The results indicate that across nine experiments, more than 2,400 participants who took an absolute approach to the dilemmas (like refusing to kill an innocent person, even when this maximised the greater good) were seen as more trustworthy than those who advocated a more flexible approach. 

When asked to entrust a person with a sum of money, participants handed over more money and were more confident of getting it back, when dealing with someone who refused to sacrifice one to save many. 

"This explains why we appear to like people who stick to these intuitive moral rules -- not because they are sticklers for the letter of the law, but because the rules themselves tend to emphasize the absolute importance of respecting the wishes and desires of others," added David Pizarro from Cornell University in the US.

Our day-to-day moral decisions don't fit into the neat categories defined by moral philosophers. Instead, real life morality is suited to the complexity of real life situations, the researchers suggested in a paper that appeared in the Journal of Experimental Psychology: General. ​

New York, April 11 (IANS) Scientists have invented a “smart” paint spray can that robotically reproduces photographs as giant murals.

The computerised technique which basically spray paints a photo is not likely to spawn a wave of giant graffiti but it can be used in digital fabrication, digital and visual arts, artistic stylisation and other applications, said the team from Dartmouth college and colleagues.

The system uses an ordinary paint spray can, tracks the can's position relative to the wall or canvas and recognises what image it "wants" to paint. 

As the person waves the pre-programmed spray can around the canvas, the system automatically operates the spray on and off button to reproduce the specific image as a spray painting.

“We show that by combining computer graphics and computer vision techniques, we can bring such assistance technology to the physical world even for this very traditional painting medium, creating a somewhat unconventional form of digital fabrication,” said study co-author Wojciech Jarosz who worked as senior research scientist at Disney Research Zurich. 

“We wanted to maintain the aesthetic aspects of physical spray painting and the tactile experience of holding and waving a physical spray can while enabling unskilled users to create a physical piece of art,” he added.

The prototype includes two webcams and QR-coded cubes for tracking and a small actuation device for the spray can 00 attached via a 3D-printed mount. 

Paint commands are transmitted via radio directly connected to a servo-motor operating the spray nozzle. 

Running on a nearby computer, the real-time algorithm determines the optimal amount of paint of the current colour to spray at the spray can's tracked location. 

“The end result is that the painting reveals itself as the user waves the can around, without the user necessarily needing to know the image beforehand,” the team noted in a paper that appeared in the journal Computer & Graphics. ​

​New York, April 11 (IANS) US doctors, including an Indian American doctor reported the first case of a human patient whose severely damaged oesophagus was reconstructed using commercially available stents and skin tissues.

After the 24-year-old man was paralysed in a car crash seven years ago, doctors struggled to repair his disrupted oesophagus.

Despite several surgeries, the defect in the oesophagus was too large to repair and it was resulting in life-threatening infection, the physicians noted in the paper published in the journal in The Lancet.

The team of doctors decided to try a technique previously tested only in animals, to reconstruct the upper oesophagus with stents and skin tissue approved by the US Food and Drug Administration.

"This is a first in human operation and one that we undertook as a life-saving measure once we had exhausted all other options available to us and the patient,” Kulwinder Dua, professor at Medical College of Wisconsin in the US. 

The doctors used metal stents as a non-biological scaffold and a regenerative tissue matrix from donated human skin to rebuild a full-thickness five cm defect in the oesophagus of the patient.

They inserted an endoscope containing a wire through the man's stomach and up through what remained of his oesophagus, leading to his mouth. 

Guided by the wire, they then inserted three stents to recreate the structure of the oesophagus and covered it with skin tissue. 

The tissue was then sprayed with a gel made from the patient's own blood, which contained natural substances to attract stem cells.

Although the doctors wanted to remove the stents about three months after the surgery, the patient refused, fearing he would not be able to eat and drink; he was also worried about possible scarring. 

Nearly four years later, doctors removed the stents after the man had trouble swallowing when a problem arose with the lower stent.

One year after that, doctors examined the man's oesophagus and found that all five layers of the oesophagus had regrown, closely resembling a normal one. 

The patient now does not need a feeding tube and also has not reported any other complications.

Swallowing tests showed full recovery and functioning was also established with oesophageal muscles able to propel water and liquid along the oesophagus into the stomach in both upright and 45 degrees sitting positions.

"The approach we used is novel because we used commercially available products which are already approved for use in the human body and hence didn't require complex tissue engineering," Dua explained.

The research including animal studies and clinical trials, are now needed to investigate whether the technique can be reproduced and used in other similar cases.

“The use of this procedure in routine clinical care is still a long way off as it requires rigorous assessment in large animal studies and phase one and two clinical trials," Dua stated.

The oesophagus is a hollow muscular tube that connects the mouth to the stomach carrying food and liquids.

​Canberra, April 11 (IANS) The number of tigers in the wild has risen for the first time in 100 years, marking a major turning point in the big cat's plight against poaching and habitat loss.

Figures collated from national surveys conducted in tiger range states and from the International Union for Conservation of Nature (IUCN), estimate the number of tigers living in the wild to be around 3,890.

That is up almost 700 animals from the 2010 figure, which estimated their numbers at 3,200, ABC reported.

Current tiger estimates across Asia are: 2,226 tigers in India, 433 in Russian Siberia, 371 in Indonesia, 250 in Malaysia, 198 in Nepal, 189 in Thailand, 106 in Bangladesh, 103 in Bhutan, more than seven in China, less than five in Vietnam, two tigers in Laos, and none in Cambodia. Data on tigers in Myanmar was not available.

The World Wildlife Fund (WWF) Australia's national manager for the species, Darren Grover welcomed the news, saying it was the first increase since the turn of the 20th century.

"That's great news. It's the first positive trend for wild tiger populations in more than 100 years," he said.

In 1900, approximately 100,000 tigers were estimated to be living in the wild.

"In those 100 years or so, we've lost around 97 percent of wild tigers," Grover said.

A WWF background document said the increase was likely the result of major changes made in India, Russia, Nepal and Bhutan, including improved survey techniques and ramped up conservation efforts.

But despite the increase, Grover said there was still a long way to go before tiger range states reached their goal of doubling the number in the wild by 2022.

In 2011, about 14 countries from across the tiger range, which extends from India across South Asia and to Far East Russia, got together in St. Petersburg in Russia and agreed to the Tx2 target.

"They took 3,200 as the number at that time, so that would mean they are aiming for a wild tiger population of around 6,400 by 2022," Grover said.

"We're on the way towards that target. We're obviously making progress, but there is still quite some way to go."

Grover said some countries, such as Malaysia, China and Thailand, were holding back efforts by failing to conduct habitat surveys.

"There is some information available on how many tigers remain in those countries, but until we do those accurate surveys, we won't know for sure," he said.

"The good thing is, most of those countries have committed to doing those surveys over the next year or so, so that will enlighten us to a more accurate figure and hopefully show that that overall number is increasing further."

He said in the meantime, tourists needed to be aware of the overseas practices threatening tigers in the wild.

"While loss of habitat has been a major reason for the decline in tiger numbers, the illegal poaching of tiger and the use of products in traditional medicines is also a major factor behind the decline in tiger populations," he said.

"We really urge people who are going to these countries, if you're in markets and you are seeing what are claimed to be tiger products, don't purchase them."

"As we like to say, there's only one place where those tiger products should be, and that's in a tiger."​

London, April 11 (IANS) In a first, researchers have shown that ribose - a sugar that is one of the building blocks of genetic material in living organisms - may have formed in ice on comets.

The genetic material of all living organisms on Earth, as well as of viruses, is made up of nucleic acids, DNA and RNA. 

Scientists have long wondered about the origin of these biological compounds. 

Some believe that the Earth was seeded by comets or asteroids that contained the basic building blocks needed to form such molecules. 

Ribose, the other key component of RNA, had never yet been detected in extraterrestrial material or created in the laboratory under “astrophysical” conditions. 

Now, by simulating the evolution of the interstellar ice making up comets in the lab, French research teams have successfully obtained ribose - a key step in understanding the origin of RNA and of life.

To obtain this result, scientists at the Institut de Chimie de Nice, University of Nice-Sophia Antipolis, in France carried out a highly detailed analysis of an artificial comet.

The astrophysicists simulated the formation of dust grains coated with ice, the raw material of comets. 

They then proposed the first realistic scenario for the formation of this key compound which had never been detected in meteorites or cometary ices until now. 

Although the existence of ribose in real comets remains to be confirmed, this discovery completes the list of the molecular building blocks of life that can be formed in interstellar ice. 

“It also lends further support to the theory that comets are the source of the organic molecules that made life possible on Earth, and perhaps elsewhere in the universe,” the authors noted in a paper published in the journal Science.​

​London, April 12 (IANS) e-cigarette smoking is increasingly promoted as a safer alternative to cigarette smoking but a team of researchers has found that e-cigarettes have immediate effects on pulmonary function in mild asthmatic young smokers.

The findings showed that e-cigarette smoking caused acute pulmonary function impairment, lasting for less than 30 minutes after smoking.

"The results show that as it happens with cigarette smoking, e-cigarette smoking has more deleterious short-term effects on asthmatics compared with healthy smokers," said Andreas Lappas from the Hellenic Cancer Society in Athens, Greece. 

In a study, published in the journal CHEST, of 54 young cigarette and e-cigarettes smokers aged 18-31, 27 had mild controlled asthma and the other 27 were healthy. 

The results suggest that measurements of airway obstruction and inflammation were worse after e-cigarette sessions and these findings were more severe in asthmatics.

"It adds to the growing body of research pointing to the dangers of e-cigarettes. Especially for asthma, further research is needed in order to assess the risks of long-term e-cigarette use," Lappas added.

The study is set to be presented at the "CHEST World Congress 2016" in Shanghai, China, on April 15-17. ​

New York, April 12 (IANS) A team of scientists has discovered six new proteins that may help reveal secrets of how humans age -- potentially unlocking new insights into diabetes, Alzheimer's disease, cancer and other ageing-related problems.

The researchers found that these tiny proteins are produced naturally in the energy-generating mitochondria -- the powerhouse in human cells -- and play key roles in metabolism and cell survival.

"The findings are an important advance that will be ripe for rapid translation into drug development for diseases of ageing," said lead researcher Pinchas Cohen from University of Southern California in the US.

The amount of each protein decreases with age, leading to onset of diseases linked to older age.

To learn further, the team used computer analysis and uncovered the genes for six new proteins which were dubbed small humanin-like peptides (SHIP).

"The newly recognised SHLP family expands the understanding of the mitochondria as an intracellular signalling organelle that communicates with the rest of the body to regulate metabolism and cell fate," Cohen explained.

After identifying the six new proteins and successfully developing antibodies to test for several of them, the researchers examined both mouse tissues and human cells to determine their abundance in different organs as well as their functions. 

The proteins were distributed quite differently among organs, suggesting that the proteins have varying functions based on where they are in the body.

The results revealed that these tiny proteins plays several big roles in our bodies' cells, from decreasing the amount of damaging free radicals and controlling the rate at which cells die to boosting metabolism and helping tissues throughout the body respond better to insulin. ​