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 York, July 26 (IANS) In a first, a team of astronomers has found that the Milky Way's halo is spinning in the same direction and at comparable speed as the galaxy's disk -- providing a potential explanation for the "missing" mass of our galaxy.

"This flies in the face of expectations. People just assumed that the disk of the Milky Way spins while this enormous reservoir of hot gas is stationary -- but that is wrong. This hot gas reservoir is rotating as well, just not quite as fast as the disk," said Edmund Hodges-Kluck from the University of Michigan.

The new knowledge sheds light on how individual atoms have assembled into stars, planets and galaxies like our own, and what the future holds for these galaxies.

The researchers used the archival data obtained by XMM-Newton -- a European Space Agency telescope. The results of their analysis was recently published in the Astrophysical Journal.

According to the team, our galaxy's hot gaseous halo is several times larger than the Milky Way disk and composed of ionised plasma.

Because motion produces a shift in the wavelength of light, the U-M researchers measured such shifts around the sky using lines of very hot oxygen. 

What they found was groundbreaking: The line shifts measured by the researchers show that the galaxy's halo spins in the same direction as the disk of the Milky Way and at a similar speed -- 643737.6 kmph for the halo versus 869045.76 kmph for the disk.

Scientists have long puzzled over why almost all galaxies, including the Milky Way, seem to lack most of the matter that they otherwise would expect to find. 

Astronomers believe that about 80 per cent of the matter in the universe is the mysterious "dark matter" that, so far, can only be detected by its gravitational pull. But even most of the remaining 20 per cent of "normal" matter is missing from galaxy disks. 

According to the researchers, learning about the direction and speed of the spinning halo can help us learn both how the material got there in the first place and the rate at which we expect the matter to settle into the galaxy.​

​Washington, July 23 (IANS) Showing empathy comes more out of careful reasoning instead of gut intuition, new research has revealed.

According to the study, systematic reasoning appears to beat intuition for recognising emotions in others.

"Cultivating successful personal and professional relationships requires the ability to accurately infer the feelings of others - that is, to be empathically accurate. Some are better at this than others, a difference that may be explained in part by mode of thought," said Jennifer Lerner, Researcher, Harvard University in the study published in the Journal of Personality and Social Psychology. 

According to the researcher, individuals process information and make decisions in different ways. Some choose to follow their instincts and go with what feels right to them (i.e., intuitive), while others plan carefully and analyse the information available to them before deciding (i.e., systematic).

The researchers conducted four studies, involving over 900 participants, to examine the relationship between the two modes of thought and empathetic accuracy. 

The first determined that most people believe intuition is a better guide than systematic thinking to accurately infer other's thoughts and feelings. 

However, the other three studies found that the opposite is true, revealed the study.

"These findings are important because they show that commonly held assumptions about what makes someone a good emotional mind reader may be wrong," added Lerner.​

​Toronto, July 23 (IANS) In a first, Canadian veterinary researchers have successfully produced three wood bison calves using in vitro fertilisation.

Indigenous to Canada, the wood bison are threatened both by disease and loss of habitat.

Between 5,000 and 7,000 wood bison remain in the wild -- less than five per cent of their original numbers. 

Scientists hope that this reproductive breakthrough by researchers from the University of Saskatchewan will help retain genetic diversity and eventually rebuild the depleted wild herds.

"The babies look great," said Gregg Adams, Professor at Western College of Veterinary Medicine (WCVM), University of Saskatchewan.

"They're keeping up with mom, and I'm really happy about it," Adams said in a university statement.

Researchers produced them in a laboratory, then transferred the embryos into surrogate mothers more than nine months ago. The bison cows gave birth to the calves earlier this month, the statement added.

A fourth calf was produced from a frozen embryo that was taken from a bison cow in 2012 and transferred to a surrogate mother in 2015 -- another reproductive first for the bison species, the researchers said.

"The whole objective of our programme is to conserve the species. I think what we're doing with advanced reproductive technologies is really designed to preserve the genetic diversity (of the animals)," Adams said. 

"If we can preserve the genetic diversity, I'll feel like I've done my job. That will benefit both the wild populations as well as any livestock producers," Adams noted.​

​Tokyo, July 25 (IANS) Researchers have discovered a very unusual zoantharian species on the east coast of Okinawa Island in Japan.

Generally, most known zoantharians are colonial (hence their common name of 'colonial anemones'), and many dwell in shallow waters of subtropical and tropical regions, where their large colonies can be found on coral reefs.

But the new species, named Sphenopus exilis, were leading solitary lives, the researchers reported in the journal ZooKeys.

"This report demonstrates how much more research is needed on these understudied ecosystems," said lead author Takuma Fujii from Kagoshima University in Japan.

"The only reason this species was discovered was that the right person was in the right place at the right time," said study co-author James Davis Reimer from the University of Ryukyus in Nishihara, Japan.

Solitary zoantharian species, such as this one, are known from a scant few reports, and only three species are described, all reported more than 100 years ago from the Indo-Pacific region.

The new species is much smaller than the other three Sphenopus species, with its polyps measuring approximately three cm in length, the study said.​

London, July 25 (IANS) To better treat a variety of diseases, researchers have developed soft, flexible and motor-less microrobots that can be remotely controlled with electromagnetic fields.

Made up of a biocompatible hydrogel and magnetic nanoparticles, these microbots can move and swim inside the patient's body when an electromagnetic field is applied, accoding to the researchers from Ecole Polytechnique Federale De Lausanne, Switzerland who developed bio-inspired robots that looks and moves like a bacterium. 

To build one of these microrobots, the nanoparticles were first placed inside layers of a biocompatible hydrogel. 

Then, an electromagnetic field was applied to orientate the nanoparticles at different parts of the robot, followed by a polymerisation step to "solidify" the hydrogel. 

After this, the robot was placed in water where it folded in specific ways depending on the orientation of the nanoparticles inside the gel, to form the final overall 3D architecture of the microrobot.

Once the final shape was achieved, an electromagnetic field was used to make the robot swim. Then, when heated, the robot changed shape and unfolded. 

This fabrication approach allowed the researchers to build microrobots that mimic the bacterium that causes African trypanosomiasis, otherwise known as sleeping sickness. 

This particular bacterium uses a flagellum for propulsion, but hides it away once inside a person's bloodstream as a survival mechanism.

The researchers tested different microrobot designs to come up with one that imitated this behaviour. The prototype robot has a bacterium-like flagellum that enables it to swim. When heated with a laser, the flagellum wraps around the robot's body and is "hidden".

Scientists around the world have been studying ways to use miniature robots to better treat a variety of diseases. 

The robots are designed to enter the human body, where they can deliver drugs at specific locations or perform precise operations like clearing clogged-up arteries.

The work was published in the journal Nature Communications.​