Knowledge Update

​New York, July 24 (IANS) Dietary changes in the US could feed significantly more people from existing agricultural land, suggests a new study that takes into account the per-person land requirements of different diets.

Using 10 different scenarios ranging from the average American diet to a purely vegan one, a team led by scientists from the Tufts University estimated that agricultural land in the contiguous US could have the capacity to feed up to 800 million people -- twice what can be supported based on current average diets.

The new "food-print" model, published recently in the journal Elementa, shows that a vegetarian diet that includes dairy products could feed the most people from the area of land available.

"Our approach challenges the 20th century emphasis on increasing yield and production. Improving crop yields remains vitally important, but it is not the only way to increase the number of people fed per acre. Our aim is to identify potential agricultural-sustainability strategies by addressing both food consumption and production," said lead author Christian Peters.

The researchers found that a lacto-vegetarian diet (a vegetarian diet that includes dairy products) had the highest carrying capacity, meaning that it could feed the most people from the area of land available.

Diets including some meat can feed more people than vegan diets, depending on estimates of how much land is suitable for crop cultivation, while the baseline diet had the lowest carrying capacity and required eight times more land than a vegan diet.

As the amount of meat in the diet was reduced between scenarios, the amount of land necessary for crops to feed livestock was also reduced.

"In our study, the estimates of carrying capacity for each diet are sensitive to assumptions about the area available for cultivated cropping. Furthermore, since most diet scenarios were consistent with the Dietary Guidelines for Americans, differences in carrying capacity should represent the trade-offs for food preferences rather than nutritional quality," Peters said.​

​Beijing, July 26 (IANS) Archaeologists have confirmed traces of ancient humans, dating back to over 10,000 years, at an altitude of 4,000 metres in China's Qinghai-Tibet plateau.

Hou Guangliang of Qinghai Normal University confirmed that the prehistoric ash layer discovered in 2013 is a residue of human activity, Xinhua news agency reported.

Dozens of stone tools were found at the same site, showing signs of civilisation in the plateau, making it the oldest evidence of human activity at over 4,000 metres.

The discovery is of great significance to research on how ancient humans coped in extreme environments, Hou said.

The plateau has an average altitude of 4,000 metres where winter temperatures can drop to -40 degrees Celsius.​

​London, July 28 (IANS) The impact of low physical capacity on risk of death is second only to smoking, a 45 year study in middle-aged men has found.

"The risk associated with low aerobic capacity was evident throughout more than four decades and suggests that being physically active can have a big impact over a lifetime," said lead author Per Ladenvall from Sahlgrenska Academy at the University of Gothenburg, Sweden. 

"The effect of aerobic capacity on risk of death was second only to smoking," Ladenvall noted.

The study included 792 men from a representative sample of 50-year-old men in Gothenburg recruited in 1963. 

In 1967, at 54 years of age, the men did an exercise test. Of those, 656 men also did a maximum exercise test in which they pushed themselves to the limit. 

The remaining men were excluded from the maximum exercise test because they had a health condition that could make it unsafe. 

Maximal oxygen uptake, called VO2 max, was measured in a sub-population of the 656 men using ergospirometry.

After the initial examination in 1967, the men were followed up until 2012, at the age of 100 years. Several physical examinations were performed, about one every 10 years. Data on all-cause death was obtained from the National Cause of Death Registry.

"We found that low aerobic capacity was associated with increased rates of death,” Ladenvall said.

The findings, published in the European Journal of Preventive Cardiology, showed that low physical capacity is a greater risk for death than high blood pressure or high cholesterol.

"We have come a long way in reducing smoking. The next major challenge is to keep us physically active and also to reduce physical inactivity, such as prolonged sitting," Ladenvall noted.​

New York, July 28 (IANS) Scientists have developed a new space boot with built-in sensors and tiny "haptic" motors whose vibrations can help astronauts avoid the risk of tripping over obstacles.

Falls in space can jeopardise astronauts' missions and even their lives. 

If an astronaut trips over moon rocks, getting to his or her feet in a bulky, pressurised spacesuit can consume time and precious oxygen reserves. Falls also increase the risk that the suit will be punctured. 

Since most falls happen because spacesuits limit astronauts' ability to both see and feel the terrain around them, reseachers from the Massachusetts Institute of Technology (MIT) developed the boot with built-in sensors to guide the wearer around or over obstacles.

"A lot of students in my lab are looking at this question of how you map wearable-sensor information to a visual display, or a tactile display, or an auditory display, in a way that can be understood by a nonexpert in sensor technologies," said Leia Stirling from MIT's Institute for Medical Engineering and Science.

"This initial pilot study allowed Alison [Gibson, a graduate student in AeroAstro and first author on the paper] to learn about how she could create a language for that mapping," Stirling added.

The team presented a prototype of the boot recently at the International Conference on Human-Computer Interaction in Toronto, Canada.

The work could also have applications in the design of navigation systems for the visually impaired. The development of such systems has been hampered by a lack of efficient and reliable means of communicating spatial information to users.​

London, July 28 (IANS) The “screen-and-treat” initiative for hepatitis B may reduce deadly complications of the virus, according to a new study.

The study, published in the journal The Lancet Global Health, suggested that the programme is cost effective and may be able to prevent complications of the disease.

To track hepatitis infection, the researchers ran a pilot study testing people for the virus in communities in Gambia, West Africa.

In the “screen and treat” programme, the researchers used a cheap instant test to screen around 6,000 people for the virus in the Gambian community and referred infected individuals for further liver tests and treatment. 

They also screened around 6000 blood samples from blood banks where some donor's blood was infected with hepatitis B. If an infected sample was detected, the researchers contacted the donor and referred them for tests and treatment.

“Hepatitis B is the leading cause of liver cancer and cirrhosis in Sub-Saharan Africa. Yet most patients do not realise they are infected until they develop severe symptoms,” said Maud Lemoine, researcher at the Imperial College London.

The new study found 9 per cent of individuals and 13 per cent of potential blood donors tested positive for the hepatitis B virus. However, of those screened only 4 per cent of the individuals tested were deemed to have infection severe enough to require treatment with antivirals.

The initiative also had a good screening coverage of 70 per cent, and the patients who required the antivirals kept to their medication schedule over the next year, suggested the study.

“Our study shows that screen-and-treat programmes targeting the general population are a feasible -- and successful -- intervention in Sub-Saharan Africa, and should be implemented in other areas in the continent," added Lemoine.

The hepatitis B virus infects around 250 million people worldwide and is transmitted through blood and bodily fluids. However the virus causes no immediate symptoms, and can remain silent in the body for decades until triggering severe complications such as liver damage (cirrhosis) and cancer.​

​New Delhi, July 26 (IANS) Chinese internet and technology conglomerate LeEco has launched a new video membership brand targeted at young consumers at the San Diego International Comic-Con (SDCC) held between July 21 and 24 at the San Diego Convention Centre in the US. The "Letv membership for Z-Generation" was launched on July 22 at an event hosted by famous talk show comedian Joe Wong. It aims to bring a wide range of online, offline and online-to-offline membership privileges and benefits, including free movie tickets, priority to buy movie and TV show merchandise, fan events, birthday package, production site visits, offline parties, movie previews, and participation in cast selection and crowdfunding. LeEco has entered into a strategic cooperation agreement with American film production/distribution studio Lionsgate to license content from its Comic-Con HQ streaming service, under which "Letv membership for Z-Generation subscribers" can view hours of exclusive content.​

Beijing, July 26 (IANS) Chinese smartphone manufacturer Gionee on Tuesday unveiled its much-awaited flagship smartphones M6 and M6 Plus. M6 is equipped with a front fingerprint scanner, privacy protection and malware destruction although it lacks the hardware encryption feature. While M6 is packed with 5000mAh battery, M6 Plus houses 6020mAh battery unit. M6 features a 5.5-inch full HD AMOLED display, 4GB RAM, 64GB in-built memory that can be expanded up to 128GB and runs on Amigo 3.2 operating system on top of Android 6.0. M6 sports 13MP rear camera and a 8MP front camera. "Gionee M6 has outstanding performance via the breakthrough software and hardware which will make every consumer smile from their heart," said William Lu, President, Gionee, in a statement.​

​Beijing, July 26 (IANS) Chinese smartphone maker Oppo is now the leader in the home smartphone market with 23 per cent market share, followed by Huawei with 17.4 per cent and Vivo with 12 per cent, a media report said on Tuesday. Oppo's market share right now is also more than both Apple and Samsung combined in China. Apple's share in China has shrunk to 2014 levels at nine per cent and Xiaomi is at a three-year low with 6.8 per cent. Back in 2014, Oppo was responsible for less than two per cent of the smartphones sold in China. By June 2015, Oppo's share has grown up to 6.1 per cent and now in June this year, its up to a historic high at 22.9 per cent, tech website GSMArena reported. Prior to this, Huawei and Xiaomi were leading the way. In fact, Xiaomi appears to only make 6.8 per cent of China’s smartphones, down from 15.1 per cent in the previous year. Oppo R9, sold elsewhere as Oppo F1 Plus, is the best-selling device in June with five per cent market share. Oppo will be launching its next selfie-focused smartphone, the Oppo F1s, a successor to the popular Oppo F1 device, on August 3. Billed as a "selfie expert," the device can have some improvements in the camera compared to that of its predecessor but it's still not confirmed exactly what will be better this time around.​

​Beijing, July 26 (IANS) Riding on smartphone sales like its flagship H1 device, Chinese smartphone maker Huawei has posted a 40 per cent half-yearly profit.

"We are confident that Huawei will maintain its current momentum, and round out the full year in a positive financial position backed by sound ongoing operations,"

​Washington, July 26 (IANS) India has discovered large, highly enriched accumulations of natural gas hydrates in the Bay of Bengal that has the potential to be tapped, according to the US Geological Survey (USGS), which participated in the discovery efforts.