Knowledge Update

New York, June 3 (IANS) A massive amount of ammonia gas lies beneath the colourful clouds on Jupiter, astronomers have revealed, a discovery coming just a month prior to the arrival of NASA's Juno spacecraft at the planet on July 4.

Using the Karl G. Jansky Very Large Array in New Mexico, the researchers from University of California-Berkeley measured radio emissions from Jupiter's atmosphere in wavelength bands where clouds are transparent. 

The observers were able to see as deep as 100 km below the cloud tops, a largely unexplored region where clouds form.

The planet's thermal radio emissions are partially absorbed by ammonia gas. Based on the amount of absorption, the researchers could determine how much ammonia is present and at what depth.

“We, in essence, created a three-dimensional picture of ammonia gas in Jupiter's atmosphere, which reveals upward and downward motions within the turbulent atmosphere," said principal author Imke de Pater, a UC Berkeley professor of astronomy.

The map bears a striking resemblance to visible-light images taken by amateur astronomers and the Hubble Space Telescope.

The study will shed light on similar processes occuring on other giant planets in our solar system and on newly-discovered giant exoplanets around distant stars.

The radio map shows ammonia-rich gases rising into and forming the upper cloud layers.

Conversely, the radio maps show ammonia-poor air sinking into the planet, similar to how dry air descends from above the cloud layers on Earth.

The map also shows that hotspots -- so-called because they appear bright in radio and thermal infrared images -- are ammonia-poor regions that encircle the planet like a belt just north of the equator. Between these hotspots are ammonia-rich upwellings that bring ammonia from deeper in the planet.

“With radio, we can peer through the clouds and see that those hotspots are interleaved with plumes of ammonia rising from deep in the planet, tracing the vertical undulations of an equatorial wave system," said UC Berkeley research astronomer Michael Wong.

The observations were reported in the journal Science at a time when NASA's Juno spacecraft plans, in part, to measure the amount of water in the deep atmosphere where the Very Large Array looked for ammonia.

"Maps like ours can help put their data into the bigger picture of what's happening in Jupiter's atmosphere," de Pater noted.​

​London, June 3 (IANS) A test to identify long-term memory loss is likely to provide an early indication of Alzheimer's disease and potentially help in reversing its effects by the development of new treatment, new research suggests.

Alzheimer's disease is caused by proteins building up in the brain to form structures called plagues and tangles. This leads to the loss of connection between nerve cells and, eventually, to the death of the nerve cells and loss of brain tissue.

The findings showed that testing memory over a long timescale reveals early deficits in the brain's ability to remember. These are not detected by checks for short-term forgetfulness, which is the current practice for diagnosis.

When short-term memory is used to diagnose Alzheimer's disease - as is currently the case - it may not reveal the true extent of memory loss at the onset of the condition.

By testing long-term memory, it may be possible to detect the earliest signs of Alzheimer's disease and offer interventions sooner.

A brain scan in combination with a memory test could identify early abnormalities in the brain activity of Alzheimer's patients that would be otherwise undetected, the researchers said.

The researchers studied long-term memory in young mice, some of which had the equivalent of very early stage Alzheimer's disease, and some of which were healthy.

Both groups were taught to locate a hidden platform in a pool filled with water, using signs on the wall of the room to navigate.

The results showed that when tested shortly after the initial task, both groups of mice were able to remember the way to their destination.

However, when both groups were tested one week later, the mice in the Alzheimer's group had significantly more difficulty remembering the route.

Tests revealed that brain activity was normal in both groups of mice at their young age when no task was involved.

"We recognise that tests with animals must be interpreted with caution, but the use of these genetic models in conjunction with appropriate testing is pointing at an important dimension of early diagnosis," said lead researcher Richard Morris, Professor at University of Edinburgh in Britain. 

"It is widely acknowledged that earlier intervention is needed to effectively treat Alzheimer's disease, and better diagnostic tools are needed for that. We believe that our approach could make a significant contribution," added Vassilios Beglopoulos from University of Edinburgh.

New York, June 3 (IANS) Each injury could mean a little more for the elderly -- more impact and more healing time. A new study has now found that the skin's ability to repair itself takes longer as we age because the healing function of sweat glands declines with time.

"We've identified, for the first time, the cellular mechanisms of altered skin wound repair in elderly patients," said study first author Laure Rittie from the University of Michigan.

The researchers compared 18 elderly person's skin to 18 young adults' skin, to see how each group healed from skin lesions. 

The lesions were smaller than the diametre of a pencil eraser, performed under local anesthesia.

The researchers had already determined that eccrine sweat glands, which are located throughout the body, are important for wound closure. 

They are major contributors of new cells that replace the cells that were lost due to injury. This finding led to a new research question.

"Since we know elderly people tend to sweat less than young adults, we concentrated on this healing function of sweat glands," Rittie said.

In young people, they discovered sweat glands contributed more cells to wound closure than in aged adults. 

The cells in aged skin were not as cohesive, either. Fewer cells participating, spaced further apart, means a delay in wound closure and a thinner repaired epidermis in aged versus young skin.

It was not that the sweat glands were less active in older people, rather, that the environment in the ageing skin had been slowly degraded, making the skin structures less able to support the new cells that were generated, the study said.

The findings were published in the journal Aging Cell.

"This tells us that, beyond the frustrating appearance, skin ageing also negatively impacts the ability of the skin to repair itself," Rittie noted.​

​London, June 3 (IANS) Your loving dog may have come into being independently from two separate -- possibly now extinct -- wolf populations that lived on opposite sides of the Eurasian continent, new research has revealed.

An international team of scientists compared genetic data with existing archaeological evidence and found that dogs may have been domesticated not once, as widely believed, but twice.

A review of the archaeological record shows that early dogs appear in both the East and West more than 12,000 years ago, but in Central Asia no earlier than 8,000 years ago.

"Our ancient DNA evidence, combined with the archaeological record of early dogs, suggests that we need to reconsider the number of times dogs were domesticated independently,” said professor Greger Larson from University of Oxford.

The project on dog domestication, led by University of Oxford, reconstructed the evolutionary history of dogs by first sequencing the genome (at Trinity College Dublin) of a 4,800-year old medium-sized dog from bone excavated at the Neolithic Passage Tomb of Newgrange, Ireland.

The team (including French researchers based in Lyon and at the National Museum of Natural History in Paris) also obtained mitochondrial DNA from 59 ancient dogs living between 14,000 to 3,000 years ago and then compared them with the genetic signatures of more than 2,500 previously studied modern dogs.

Combined, the new findings suggest that dogs were first domesticated from geographically separated wolf populations on opposite sides of the Eurasian continent.

At some point after their domestication, the eastern dogs dispersed with migrating humans into Europe where they mixed with and mostly replaced the earliest European dogs.

Most dogs today are a mixture of both Eastern and Western dogs -- one reason why previous genetic studies have been difficult to interpret.

The new genetic evidence also shows a population turnover in Europe that appears to have mostly replaced the earliest domestic dog population there, which supports the evidence that there was a later arrival of dogs from elsewhere.

"The Newgrange dog bone had the best preserved ancient DNA we have ever encountered, giving us prehistoric genome of rare high quality. It is not just a postcard from the past, rather a full package special delivery,” added senior author professor Dan Bradley from Trinity College Dublin in a paper appared in the journal Science.

"With so much new and exciting data to come, we will finally be able to uncover the true history of man's best friend,” noted professor Keith Dobney, co-author from Liverpool University.​

​London, June 3 (IANS) The elderly are less willing to indulge in risk-taking behaviour for potential rewards when compared to youngsters because of the declining levels of dopamine in the brain, finds a study.

Dopamine is a chemical in the brain involved in predicting which actions will lead to rewards and has been known to fall by up to 10 per cent every decade throughout adult life.

The findings showed that older people were not overall more risk-averse as well as they didn't make much mistakes as compared to young adults. 

Rather, the elderly were found simply less attracted to big rewards and this made them less willing to take risks to try to get them, the researchers said.

"The findings offer a potential neuroscientific explanation, suggesting that a natural decline in dopamine with age might make people less receptive to the positive approach than they would have been when they were younger," said lead author Robb Rutledge from University College London.

The steady decline in risky choices with age matched up with the declining dopamine level.

However, they were no different to younger participants when it came to choosing risky gambles to avoid losing points. 

"As one ages, the dopamine levels naturally decline explaining the reason why one is less likely to seek rewards," added Rutledge.

The study, published in Current Biology, involving 25,189 smartphone users aged 18-69, found that older people were less likely to choose risky gambles to win more points in a smartphone app called The Great Brain Experiment.

In the game, players start with 500 points and aim to win as many points as possible in 30 different trials where they must choose between a safe option and a risky 50/50 gamble.

"This study is an excellent example of the use of digital technology to produce new and robust insights into the workings of the brain," explained Raliza Stoyanova from the neuroscience and mental health team at Wellcome Trust in Britain.​

Bangkok, June 3 (IANS) The discovery of more than 40 dead tiger cubs in Thailand's Tiger Temple represents only a "tiny proportion" of the enormous extent of an illegal trade in wildlife that is "pushing species to the brink of extinction", the UNEP-UNODC said on Friday.

"While circumstances of their death remain unclear, sadly, those tiger cubs represent only a tiny proportion of the enormous extent of an illegal trade in wildlife that is pushing species to the brink of extinction. Indeed, only around 4,000 tigers are left in the wild," United Nations Environment Programme-United Nations Office on Drugs and Crime (UNODC) said in a statement.

"Until the illegal trade in wildlife is stopped, we are only likely to see more of these types of situations," the statement added.

The theme for World Environment Day on June 5 this year is the illegal trade in wildlife to raise awareness of this severe problem. Tigers are one of the key species in the campaign.

The illegal trade in wildlife, estimated to profit criminals to the tune of billions of dollars annually worldwide, comprises everything from the lucrative trade in Tiger parts in East Asia to ivory from African elephants, the organisations said.

"It undermines our environment, economies, communities and security."

"The commendable action by Thailanda's authorities, coordinated by the Department of National Parks, Wildlife and Plant Conservation, highlights the need for constant vigilance by wildlife law enforcement authorities to the threat posed by traffickers."

"Given the extent of the illegal wildlife market in Asia it is important for all countries to unite and eradicate these illegal practices," the statement said.

Officials had recovered 40 dead tiger cubs, just one to two days old, from a freezer at Wat Pha Luang Ta Bua temple, known as the "Tiger Temple", on Wednesday, EFE news reported.

The cubs were not recorded in the register for wild animals the temple has to maintain by law and that means the protection department will press charges for illegal possession, besides other possible offences.​

​New York, June 3 (IANS) By fabricating tiny lasers directly on silicon, an international group of scientists has found a way that could make microprocessors run faster without consuming more power.

The group of scientists from Hong Kong University of Science and Technology, the University of California, Santa Barbara, Sandia National Laboratories and Harvard University grew tiny high-performance lasers directly on silicon wafers.

Reported in the journal Applied Physics Letters, the group said integrating subwavelength cavities -- the essential building blocks of tiny lasers -- onto silicon enabled them to create and demonstrate high-density on-chip light-emitting elements.

"Putting lasers on microprocessors boosts their capabilities and allows them to run at much lower powers, which is a big step toward photonics and electronics integration on the silicon platform," said professor Kei May Lau from Hong Kong University of Science and Technology.

The scientists used "tiny whispering gallery mode lasers -- only 1 micron in diameter -- that are 1,000 times shorter in length and 1 million times smaller in area than those currently used."

In terms of applications, the group's tiny lasers on silicon are ideally suited for high-speed data communications.​

​New York, June 2 (IANS) Some periodic comets -- objects that orbit the Sun in 200 years or less -- may regularly split in two and then reunite down the road, a new study has found.

According to a team from Purdue University and University of Colorado Boulder (CU-Boulder), this may be a repeating process fundamental to comet evolution.

Led by Purdue postdoctoral fellow Masatoshi Hirabayashi and CU-Boulder Professor Daniel Scheeres, the team studied a rubber duck-shaped comet known as 67P/Churyumov-Gerasimenko (67P). 

Images of 67P show two cracks on the comet's neck that connects its two larger lobes.

In order to reconstruct the past life of 67P, the team used numerical models in which the spin rate was cranked up from its roughly one rotation every 12 hours today to one rotation every seven to nine hours.

The models showed the faster spin would lead to more stress and the formation of two similar cracks on the neck of 67P in the same location.

"Our spin analysis predicted exactly where these cracks would form," Scheeres said, adding that "we now have a new understanding of how some comets may evolve over time".

The models run by the team showed that if 67P's spin is increased to less than seven hours per rotation, the head will pop off.

"The head and body aren't going to be able to escape from each other," he said. 

"They will begin orbiting each other, and in weeks, days or even hours they will come together again during a slow collision, creating a new comet nucleus configuration," Scheeres noted.

This pattern could go on for the life of the comet, said Scheeres in a paper published in the journal Nature.​

Washington, June 3 (IANS) A wearable artificial kidney could be developed as a viable, new dialysis technology that allows patients to be mobile and untethered during treatment, results of a US Food and Drug Administration-authorised clinical trial suggest.

The technology may become an alternative to conventional hemodialysis for people with end-stage kidney disease. 

Present-day treatment generally requires three sessions a week on a stationary machine that restricts patients' ability to walk around while it is attached and running.

In contrast, a wearable device would allow patients to be mobile and untethered. It could also provide additional treatment benefits from longer sessions or more frequent days of dialysis.

The trial of a prototype for such a device was performed with seven patients at University of Washington Medical Center in Seattle.

Those leading the trial included the inventor of the device, Wearable Artificial Kidney prototype, Victor Gura of Cedar-Sinai Medical Center in Los Angeles.

The findings were reported in the journal JCI Insights.

The trial was conducted to determine the safety and efficacy of the device - its ability to take over some functions of failed kidneys. 

The researchers also wanted to ask the participants about their impressions of the experimental treatment, and to compare those with standard dialysis treatment.

The patients were treated with the device for up to 24 hours.

In the patients studied, the device was shown to effectively clear the blood of waste products, like urea, creatinine and and phosphorus, while also removing excess water and salt. These are normally filtered out and removed by working kidneys.

While the usual diet for patients on standard dialysis is highly limited, their blood fluid volume of those on the wearable device remained balanced during the test, even without any diet restrictions.

Regulating the volume and composition of body fluids is another job of normal kidneys.

During the trial, the participants tolerated the treatment well and did not have any serious, adverse effects. 

However, this trial of the device was stopped after the seventh patient because of technical problems with the device. These included the excessive formation of carbon dioxide gas bubbles in the dialysis solution, and intermittent variations in solution and blood flow.

Nevertheless, the findings provide proof of concept that a wearable devise along these lines could be developed as a viable, novel dialysis technology, the researchers said​

​New York, June 3 (IANS) Social media giant Facebook on Friday announed that it will pull its own "Notify" app -- created to send notifications from a list of news sources including Bloomberg Business, CNN and The New York Times on to your locked smartphone screen -- from App Store.