Knowledge Update

Seoul, March 15 (IANS) Challenging a commonly held theory that changes in the Earth's orbit triggered Sahara desertification, a new study suggests that humans may have played an active role in the transition of a lush green landscape into the world's largest hot desert thousands of years ago.

The desertification of the Sahara has long been a target for scientists trying to understand climate and ecological tipping points. 

Most studies done to date point to changes in the Earth's orbit or natural changes in vegetation as the major driving forces.

In a new paper published in the journal Frontiers in Earth Science, David Wright from Seoul National University in South Korea challenges the conclusions of these studies.

"In East Asia there are long established theories of how Neolithic populations changed the landscape so profoundly that monsoons stopped penetrating so far inland," said Wright. 

Evidence of human-driven ecological and climatic change has been documented in Europe, North America and New Zealand, said Wright who believed that similar scenarios could also apply to the Sahara.

To test his hypothesis, Wright reviewed archaeological evidence documenting the first appearances of pastoralism across the Saharan region, and compared this with records showing the spread of scrub vegetation, an indicator of an ecological shift towards desert-like conditions. 

The findings confirmed his thoughts.

Beginning approximately 8,000 years ago in the regions surrounding the Nile River, pastoral communities began to appear and spread westward, increasing at the same time the spread of scrub vegetation, the study said.

Growing agricultural addiction had a severe effect on the region's ecology. As more vegetation was removed by the introduction of livestock, it increased the albedo (the amount of sunlight that reflects off the earth's surface) of the land, which in turn influenced atmospheric conditions sufficiently to reduce monsoon rainfall. 

The weakening monsoons caused further desertification and vegetation loss, promoting a feedback loop which eventually spread over the entirety of the modern Sahara, the study said.

London, March 15 (IANS) Stimulating the brain with electricity may synchronise brain waves and help improve short-term working memory that could improve treatments for people with traumatic brain injury, stroke or epilepsy, a study has found.

According to researchers, applying a weak electrical current through the scalp can align different parts of the brain, synchronising brain waves and enabling people to perform better on tasks involving working memory.

"What we observed is that people performed better when the two waves had the same rhythm and at the same time," said lead author Ines Ribeiro Violante, a neuroscientist at the Imperial College London.

"The hope is that it could eventually be used for patients with brain injury, or even those who have suffered a stroke or who have epilepsy," Violante added. 

For the study, published in the journal eLife, the team used a technique called transcranial alternating current stimulation (TACS) to manipulate the brain's regular rhythm in 10 volunteers.

Using TCAS, the researchers targeted two brain regions -- the middle frontal gyrus and the inferior parietal lobule -- known to be involved in working memory.

The findings revealed that when the brain regions were stimulated in sync, reaction times on the memory tasks improved.

Functional MRI images of the brain showed changes in activity occurring during stimulation, with the electrical current potentially modulating the flow of information.

"The results show that when the stimulation was in sync, there was an increase in activity in those regions involved in the task. When it was out of sync, the opposite effect was seen.

"The hope is that it could eventually be used for patients with brain injury, or even those who have suffered a stroke or who have epilepsy," Violante added.

​London, March 14 (IANS) Suffering from severe back pain? Blame your clothing and accessories such as skinny jeans, oversized bags and those worn on one side of the body, coats with large fluffy hoods, high heeled shoes and backless shoes, according to a survey from the British Chiropractic Association (BCA). The survey showed that three-quarters (73 per cent) of women have suffered with back pain and their wardrobe could be a major cause of the discomfort. "While overloaded and heavy handbags are a common culprit, some more unexpected items like skinny jeans can also wreak havoc -- they restrict free movement in areas such as the hips and knees, affecting the way we hold our bodies," Tim Hutchful, chiropractor at BCA, said in a statement on Tuesday. "New trends such as asymmetric hemlines, oversized sleeves and hoods and heavy jewellery can also create problems," Hutchful added. While over a quarter (28 per cent) of women are aware clothing effects their back, one-third of women (33 per cent) were completely unaware that their choice of clothing could impact their back or neck health. "I am always surprised at how many of my patients are unaware that their clothing and accessories can affect their back health and their posture and, equally, how many decide their outfit-choice outweighs their pain," Hutchful said. Suggesting a slew of measures to reduce the impact on the posture and overall health, Hutchful suggested: "Try and limit the number of times you wear skinny jeans or high heels every week where you're giving your body a break, or try investing in a backpack for days when you have a lot to carry around."

London, March 14 (IANS) If your kid is spending three or more hours daily in front of TV, using computers, games consoles, tablets and smartphones, he or she may be at risk of developing diabetes, a study has showed. The findings showed that children with increased exposure to digital screens may be at risk of having high adiposity levels, which describes total body fat, and, crucially, insulin resistance, which occurs when cells fail to respond to insulin, the hormone produced by the pancreas to control levels of blood glucose. "Our findings suggest that reducing screen time may be beneficial in reducing Type 2 diabetes risk factors, in both boys and girls, from an early age," said Claire. M. Nightingale from St George's, University of London. "This is particularly relevant, given rising levels of Type 2 diabetes, the early emergence of Type 2 diabetes risk, and recent trends suggesting that screen time-related activities are increasing in childhood and may pattern screen-related behaviours in later life," Nightingale added, in a paper published in the journal Archives of Disease in Childhood. Children who reported spending three or more hours of daily screen time showed high ponderal index -- an indicator of weight in relation to height -- and skinfolds thickness and fat mass -- indicators of total body fat -- than in those who said they spent an hour or less on it. Further, there was also a strong link between a daily quota of three or more hours of screen time and levels of leptin, the hormone that controls appetite, glucose and insulin resistance, the researchers said. For the study, the team assessed a sample of nearly 4,500 9-10 year old pupils from 200 primary schools in London, Birmingham and Leicester for a series of metabolic and cardiovascular risk factors.

New York, March 14 (IANS) US tech giant Apple is expected to host an event where it will unveil the new iPad Pro lineup, a larger iPhone SE model with 128GB storage and new Apple Watch bands. "Rumours widely suggest at least a trio of new iPad Pro models will be unveiled as early as this month, including an all-new 10.5-inch model with slimmer bezels and updated 9.7-inch and 12.9-inch versions," tech website macrumors.com reported on Tuesday. The new 10.5-inch iPad Pro will not include Home button and is also rumored to have a higher-resolution display and quad microphones. The updated 12.9-inch iPad Pro is expected to feature a 12MP rear camera and True Tone display using advanced four-channel ambient light sensors to automatically adapt the colour and intensity of the display to match the light in the surrounding environment. Apple is also said to launch a 5.8-inch iPhone 8 with an OLED display, that may be called 'iPhone X', along with two other devices -- updated iPhone 7 and iPhone 7 Plus (with brand names as iPhone 7S and iPhone 7S Plus). The company is also planning to introduce a new connector type for accessories for the iPhone, iPad and other devices through its official Made-for-iPhone (MFi) licensing programme. Called 'Ultra Accessory Connector' (UAC), the eight-pin connector is slightly less thick than USB-C and near half as wide as both USB-C and Lightning.

​Beijing, March 14 (IANS) Retail trade in China began 2017 with a cumulative increase of 9.5 per cent between January and February -- as compared to the same period in 2016 -- which is below economists' expectations of 10.5 percent and also its slowest growth in 11 years since February 2006, official date revealed on Tuesday. According to the National Bureau of Statistics data, with a slowdown in trade, investment in fixed assets rose to 8.9 per cent year-on-year making it its largest rise since June with real estate reaching its peak in two years to stand at 8.9 per cent and industrial production accelerating to 6.3 per cent year-on-year -- three-tenths more than in December, Efe news reported. The 9.5 per cent increase in China's retail sales was seven-tenths below the rise recorded in the same period in 2016 and almost point and a half below that of December. Analysts blame this slight slowdown on the previous year's trend, as well as a decline in car sales -- affected by the partial withdrawal of the tax incentive they enjoyed until the end of the year -- fell by 1 per cent from 2016. Industrial production or industrial value-added, too, experienced a slight rise of 6.3 per cent, as compared to 5.4 per cent in the same period in 2016. This indicator measures the activity of large companies with an annual turnover of at least 20 million yuan (about $2 million). The production of steel and other metals, including cement, improved early this year, while glass, mobile phones and industrial robots saw a slowdown. Investment in fixed assets started the year with a faster growth rate, as compared to the 8.1 per cent in January and February 2016, and 7.9 per cent in the fourth quarter of last year. China, during its annual plenary session of the National People's Congress held on March 5 in Beijing, has set its growth target at 6.5 percent for 2017 as compared to 6.7 percent attained in 2016.

​Shanghai, March 14 (IANS) More than 2,000 restaurants in Shanghai have installed see-through kitchens in a bid to improve food safety, a media report said.

In these restaurants, a piece of glass separates the kitchen from the dining area so that both diners and regulators have a clear idea of what is going on behind the scenes, the People's Daily said in the report on Monday.

Currently, the number of see-through kitchens in the Pudong, where the idea was first implemented last September, has grown from 200 to 730. 

More than 70 per cent of those kitchens are also under real-time monitoring through a closed-circuit TV system, which is played on screens mounted for anyone to see. 

Wu Haiqin, an employee of the Pudong District Market Supervision Administration (PDMSA), told the People's Daily that see-through kitchens are only suitable for restaurants that do not require complicated processing. 

In order to better guarantee food safety, the closed-circuit TV systems have been gradually installed as an alternative, Wu added.

Food safety has become a hot topic once again during the ongoing fifth meeting of the 12th National People's Congress. As a result, more stringent food security regulations will be implemented in Shanghai starting from March 20. 

In the next several years, all restaurants exceeding a certain size in Shanghai will made to install see-through kitchens. 

In addition, closed-circuit TV systems will be gradually adopted by the cafeterias of schools and other institutions around the city. 

​Buenos Aires, March 14 (IANS) The worlds first fluorescent frog has been discovered in the Amazon basin in Argentina, a media report said on Tuesday.

Scientists at the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires made the discovery by accident while studying the pigment of polka-dot tree frogs, a species common to the rainforest, the Guardian said in the report.

In normal light the frog appears to have a dull, mottled brown-green skin with red dots, but under UV light it glows a bright fluorescent green.

Fluorescence -- the ability to absorb light at short wavelengths and re-emit it at longer wavelengths -- is uncommon in creatures that live on land.

The translucent frog was found to use a combination of lymph and glandular emissions to fluoresce.

The researchers, who published their discovery on Monday in Proceedings of the National Academy of Sciences, found that the trait enhanced the brightness of the frog by 19-29 per cent depending on the level of ambient light in its surroundings, the daily said.

The compound causing the blue-green glow of the polka-dot tree frog was not previously thought to exist in vertebrates and its discovery has excited researchers.

"This is very different from fluorophores found in other vertebrates, which are usually proteins or polyenic chains," Maria Gabriella Lagoria, a photochemist at the University of Buenos Aires and study co-author, told Chemistry World.

The discovery opens up the possibility that other amphibians may be able to fluoresce, particularly those with translucent skin similar to that of the tree frog.

Speaking to the journal Nature, which first published news of the fluorescent frog, co-author Julian Faivovich expressed his hope that the discovery would inspire interest in the phenomenon, saying he hoped scientists would "start carrying a UV flashlight to the field".

​London, March 14 (IANS) Although parenthood may have its share of woes, it could also hold the key to long life, particularly in older age, when health and capacity may start to decline, finds a new study.

The findings suggested that the risks of death were lower among those who had had at least one child than they were among those who were childless -- and more so among men than among women -- and were not affected by the sex of the child(ren).

"We started first at the age of 60 and we looked all the way up to the age of 100," Karin Modig from Karolinska Institute Sweden was quoted as saying by guardian.com.

At age 60, the difference in the one-year risk of death was 0.06 per cent among men and 0.16 per cent among women.

The one-year risk of death for an 80-year-old man with a child was 7.4 per cent, for example, compared with 8.3 per cent for a childless man of the same age.

The gap in absolute death risks between the two groups rose with increasing age, and was somewhat larger for men than it was for women.

By the age of 90, these differences had risen to 1.47 per cent among men and to 1.10 per cent among women.

Further, the difference in death risk was 1.2 per cent among unmarried men and 0.6 per cent among those who were married.

"Our finding that the association grew stronger when parents became older is further in agreement with study suggesting that childless people face support deficits only towards the end of life," the researchers noted, in the paper published online in the Journal of Epidemiology & Community Health.

For the study, the team tracked the lifespan from the age of 60 onwards of all men (704,481) and women (725,290) in Sweden.

Tokyo, March 14 (IANS) Japanese authorities sent a robot to the Fukushima nuclear plant on Tuesday to measure radiation levels inside and evaluate its condition ahead of a future dismantling of a reactor.

The self-propelled, remotely-operated robot is equipped with a video camera, thermometer as well as dosimeter -- to measure radiation -- among other sensors, said the Tokyo Electric Power Company (TEPCO), the maker of the bot, in a statement.

Using the recorded data and footage, experts will try to ascertain the presence of melted fuel that could have leaked from the reactor core and accumulated at the bottom of the containment vessel, something they have been unable to verify so far, Efe news reported.

Determining the exact conditions inside the reactor is a necessary step for drafting a plan on the future recovery of the nuclear fuel; a task that has been made difficult by fatal radiation levels at the heart of the nuclear installations.

TEPCO had introduced two bots into the reactor earlier but while the first one could not make it out of the reactor, the second one became inoperative due to extreme radiation.

Another robot that TEPCO sent was also damaged by radiation, but managed to record footage that supplied important information on conditions inside, said the company.

Reactors No. 1, 2 and 3 had suffered partial meltdowns due to an earthquake and a tsunami that hit Japan in March 2011.

The Fukushima nuclear accident is considered the world's worst since Ukraine's Chernobyl disaster in 1986.