Knowledge Update

New York, July 21 (IANS) Scientists have developed a new tool to scan the human brain for changes in synapses that are associated with common brain disorders.

A synapse is a junction between two nerve cells, consisting of a minute gap across which impulses pass.

The team from Yale University set out to develop a method for measuring the number of synapses, or synaptic density, in the living brain.

To quantify synapses throughout the brain, they combined Positron Emission Tomography (PET) scanning technology with biochemistry. 

A radioactive tracer was developed that, when injected into the body, binds with a key protein that is present in all synapses across the brain. 

The researchers used the imaging technique in both baboons and humans and confirmed that the new method did serve as a marker for synaptic density. 

It also revealed synaptic loss in three patients with epilepsy compared to healthy individuals.

"This is the first time we have synaptic density measurement in live human beings," said study senior author Richard Carson. 

"Up to now any measurement of synaptic density was post-mortem," he added in a paper published in the journal Science Translational Medicine.

The technique may provide insights into the diagnosis and treatment of a broad range of disorders, including epilepsy and Alzheimer's disease.​

​London, July 21 (IANS) Exercise therapy is as effective as surgery for middle-aged patients with a common type of knee injury known as meniscal tear, a study has revealed.

Meniscal tear is the damage to the rubbery discs that cushion the knee joint.

According to the study published in the journal The BMJ, the researchers suggested that supervised exercise therapy be considered a treatment option for middle-aged patients with this type of knee damage.

The research suggests that arthroscopic knee surgery offers little benefit for most patients.

The researchers carried out a randomised controlled trial for the study to compare exercise therapy with arthroscopic surgery among middle-aged patients with degenerative meniscal tears.

They identified 140 affected adults (average age 50 years), almost all of whom had no definitive x-ray evidence of osteoarthritis.

Half of the patients received a supervised exercise programme over 12 weeks (two-three sessions each week) and half received arthroscopic surgery followed by simple daily exercises to perform at home.

Thigh muscle strength was assessed at three months and knee function was recorded at two years.

No clinically relevant difference was found between the two groups for outcomes such as pain, function in sport and recreation, and knee-related quality of life. At three months, muscle strength had improved in the exercise group of patients.

No adverse events occurred in either group during the two-year follow-up. Of all participants in the exercise group, 13 crossed over to surgery during the follow-up period -- with no additional benefits.

"Supervised exercise therapy showed positive effects over surgery in improving thigh muscle strength, at least in short term. Our results should encourage clinicians and middle aged patients with degenerative meniscal tear and no radiographic evidence of osteoarthritis to consider supervised structured exercise therapy as a treatment option," University of Helsinki researcher Teppo Jarvinen said.​

Washington, July 21 (IANS) Using NASA's Hubble Space Telescope, a team of astronomers has conducted the first search for atmospheres around Earth-sized exoplanets beyond our solar system and found indications that increase the chances of presence of life on two rocky exoplanets.

The exoplanets TRAPPIST-1b and TRAPPIST-1c -- approximately 40 light years away -- are unlikely to have puffy, hydrogen-dominated atmospheres usually found on gaseous worlds.

"The lack of a smothering hydrogen-helium envelope increases the chances for habitability on these planets," said team member Nikole Lewis from Space Telescope Science Institute (STScI) in Baltimore. 

"If they had a significant hydrogen-helium envelope, there is no chance that either one of them could potentially support life because the dense atmosphere would act like a greenhouse," he added.

The planets orbit a red dwarf star at least 500 million years old, in the constellation of Aquarius.

TRAPPIST-1b completes a circuit around its red dwarf star in 1.5 days and TRAPPIST-1c in 2.4 days.

The planets are between 20 and 100 times closer to their star than the Earth is to the Sun.

Because their star is so much fainter than our sun, researchers think that at least one of the planets, TRAPPIST-1c, may be within the star's habitable zone, where moderate temperatures could allow for liquid water to pool.

Julien de Wit from the Massachusetts Institute of Technology led a team of scientists to observe the planets in near-infrared light using Hubble's Wide Field Camera 3.

They used spectroscopy to decode the light and reveal clues to the chemical makeup of an atmosphere.

"These initial Hubble observations are a promising first step in learning more about these nearby worlds, whether they could be rocky like the Earth, and whether they could sustain life," said Geoff Yoder, acting associate administrator for NASA's Science Mission Directorate in Washington.

"This is an exciting time for NASA and exoplanet research," he added.

The researchers hope to use Hubble to conduct follow-up observations to search for thinner atmospheres, composed of elements heavier than hydrogen, like those of the Earth and Venus.

"With more data, we could perhaps detect methane or see water features in the atmospheres, which would give us estimates of the depth of the atmospheres," noted Hannah Wakeford from NASA's Goddard Space Flight Centre in a paper appeared in the journal Nature.

Observations from future telescopes, including NASA's James Webb Space Telescope, will help determine the full composition of these atmospheres and hunt for potential bio-signatures.

Webb also will analyse a planet's temperature and surface pressure -- key factors in assessing its habitability.​

Geneva, July 22 (IANS) The World Meteorological Organisation (WMO) on Thursday warned global temperatures for the first six months of this year shattered more records, meaning 2016 is on track to be the world's hottest year on record.

WMO noted June marked the 14th consecutive month of record heat for land and oceans and the 378th consecutive month with temperatures above the 20th century average. The last month with temperatures below the 20th century average was December 1984, Xinhua reported.

"Another month, another record. And another. And another. Decades-long trends of climate change are reaching new climaxes, fuelled by the strong 2015-2016 El Nino," WMO Secretary-General Petteri Taalas was quoted as saying.

"The El Nino event, which turned up the Earth's thermostat, has now disappeared. Climate change, caused by heat-trapping greenhouse gases, will not. This means we face more heatwaves, more extreme rainfall and potential for higher impact tropical cyclones," Taalas added.

Meanwhile, carbon dioxide concentrations have passed the symbolic milestone of 400 parts per million (ppm) in the atmosphere so far this year. Carbon dioxide levels vary according to the season, but the underlying trend is upwards. They showed a surprising increase for the first half of 2016, rising in June 2016 to nearly 407 ppm, four ppm greater than in June 2015.

United Nations Secretary-General Ban Ki-moon has invited leaders to a special event on September 21 to deposit their instruments of ratification, acceptance, approval or accession to the Paris Agreement on climate change. 

It will also provide an opportunity for other countries to publicly commit to the agreement before the end of 2016.

London, July 20 (IANS) Greater fluctuations in "bad" cholesterol levels are likely to cause worse cognitive function like acute memory loss in elderly adults, says a research.

The findings showed that greater fluctuations in low-density lipoprotein cholesterol (LDL), or "bad" cholesterol can affect blood flow to the brain -- a process which could lead to memory loss and even Alzheimer's, according to American Heart Association. 

The study participants with the highest LDL cholesterol variability took 2.7 seconds longer on average to finish a cognitive test to name ink colours of colour words written in different ink (for example, the word blue written in red ink), compared to individuals with the lowest variability.

"While this might seem like a small effect, it is significant at a population level," said lead author Roelof Smit, doctoral student at Leiden University in the Netherlands.

The link between variability and declining cognitive function was found regardless of average bad cholesterol levels or use of cholesterol-lowering statin drugs.

In addition, greater fluctuations in bad cholesterol can lead to greater white matter hyper-intensity load -- which has been linked to dysfunctioning in endothelial cells that make up the inner lining of blood vessels, and can further lead to a cardiovascular disease.

LDL cholesterol variability may also be important to neurocognitive function, said the paper published in the journal Circulation.

"These results add an important puzzle piece to the emerging evidence that heart risk factors are closely related to brain health," Smit added.

Measurements fluctuate because of diet, exercise, frequency of cholesterol-lowering statins and other factors.

However, these fluctuations might also reflect an increasingly impaired homeostasis -- the balance between food intake and energy expenditure -- for example, due to age or underlying disease, added J. Wouter Jukema, Professor at the Leiden University.

For the study, the team involved 4,428 elderly participants from Scotland, Ireland and the Netherlands. The participants either had pre-existing heart disease or were at a higher risk for developing the condition because of histories of hypertension, cigarette smoking or diabetes.

They examined associations between LDL cholesterol variability and four cognitive measures: colour-word test for selective attention, letter-digit coding to assess information processing speed and picture-word learning to test verbal memory in two ways -- immediate recall and delayed recall after 20 minutes.​

​New York, July 20 (IANS) Researchers from Facebook's Connectivity Lab have developed a new technology that can one day make light-based wireless communications -- a far superior technology than the ones based on radio frequencies or microwaves -- a reality in the future.

The new technology can pave the way for fast optical wireless networks capable of delivering internet service to far-flung places.

"A large fraction of people don't connect to the internet because the wireless communications infrastructure is not available where they live, mostly in very rural areas of the world," said Tobias Tiecke, who led the research team. 

Light-based wireless communication, also called free-space optical communications, offers a promising way to bring the internet to areas where optical fibres and cell towers can be challenging to deploy in a cost-effective way. 

Using laser light to carry information across the atmosphere can potentially offer very high bandwidths and data capacity, but one of the primary challenges has been how to precisely point a very small laser beam carrying the data at a tiny light detector that is some distance away.

The Facebook researchers used fluorescent materials instead of traditional optics to collect light and concentrated it onto a small photodetector. 

They combined this light collector, which featured 126 sq cm of surface that can collect light from any direction, with existing telecommunications technology to achieve data rates of more than 2 gigabits-per-second (Gbps).

"We demonstrated the use of fluorescent optical fibres that absorb one colour of light and emit another colour," Tiecke said. 

"The optical fibres absorb light coming from any direction over a large area, and the emitted light travels inside the optical fibre, which funnels the light to a small, very fast photodetector," he added in a paper described in the journal Optica.

The new light collector uses plastic optical fibres containing organic dye molecules that absorb blue light and emit green light. 

This setup replaces the classical optics and motion platform typically required to point the light to the collection area.

The fast speeds are possible because less than two nanoseconds lapse between the blue light absorption and the green light emission. 

In addition, by incorporating a signal modulation method called orthogonal frequency division multiplexing, or OFDM, the researchers transmitted more than 2 Gbps despite the system's bandwidth of 100 MHz.

Toronto, July 20 (IANS) Reading fiction might be good for your mental health but exploring inner lives of characters like Jane Eyre or Anna Karenina can form ideas about others' emotions, motives and ideas, suggested a study.

According to the study published in journal Trends in Cognitive Sciences, a psychologist-novelist shows that reading or watching narratives may encourage empathy. 

"This intersection between literature and psychology has only taken off in the last few years. In part, because researchers are recognising that there is something important about imagination," said Keith Oatley, Professor, the University of Toronto Department.

Reading fiction and perhaps especially literary fiction simulates a kind of social world, prompting understanding and empathy in the reader, revealed the study. 

According to the research, people were asked to imagine phrases like "a dark blue carpet" and "an orange striped pencil" while staying in an functional magnetic resonance imaging (fMRI) machine. 

Three such phrases were enough activate the hippocampus -- brain region associated with learning and memory, suggested the study.

"This points to the power of the reader's own mind, writers don't need to describe scenarios exhaustively to draw out the reader's imagination -- they only need to suggest a scene," added Oatley. 

To measure this empathetic response the researchers were the first to use the "Mind of the Eyes Test", in which participants view 36 photographs of people's eyes and for each choose among four terms to indicate what the person is thinking or feeling. 

The researchers found that reading narrative fiction gave rise to significantly higher scores than it did while reading non-fictional books.

Similar empathy-boosting effects have been found when participants watched the fictional television drama - The West Wing or played a video game with a narrative storyline, suggested the study.

Further studies have shown that narratives can even generate empathy for a race or culture that is dissimilar to one's own.

New York, July 20 (IANS) Ants belonging to a South American group switched from a hunter-gatherer lifestyle to subsistence farming of fungi that grew on decomposing, woody plant matter some 55 to 60 million years ago, shortly after the dinosaurs died out, new research has found.

By contrast, humans began subsistence farming around 10,000 years ago, progressing to industrialised agriculture only in the past century. 

The genes of the ant farmers and their fungal crops revealed a surprisingly ancient history of mutual adaptations, said the study published in the journal Nature Communications.

This evolutionary give-and-take led to some species -- the leafcutter ants, for example -- developing industrial-scale farming that surpasses human agriculture in its efficiency, the researchers said.

Much of the research on fungus-farming ants came from scientists working in Panama through the Smithsonian Tropical Research Institute, headquartered in Panama City, during the past 25 years. 

The key chapters of the history of ant agriculture were written into the genes of both the insects and their crop fungi. 

"The ants lost many genes when they committed to farming fungi," said Jacobus Boomsma, Research Associate at Smithsonian Tropical Research Institute.

This tied the fate of the ants to their food -- with the insects depending on the fungi for nutrients, and the fungi increasing their likelihood of survival if they produced more nutritious crop. 

"It led to an evolutionary cascade of changes, unmatched by any other animal lineage studied so far," Boomsma, who is also a biology professor at the University of Copenhagen in Denmark.

The researchers found that leafcutter ant species cut and sow their underground farms daily with fresh, green plant matter, cultivating a fully domesticated species of fungus on an industrial scale that can sustain colonies with up to millions of ants.

Put in human terms, Boomsma said, the leafcutter ants' success is akin to people figuring out how to grow a single, all-purpose, disease-, pest- and drought-resistant superfood at an industrial scale, "by the time of the ancient Greek civilisation."

New York, July 20 (IANS) In addition to environmental benefits, shifting away from inefficient and polluting fuel-based lighting -- such as candles, firewood, and kerosene lanterns -- to solar-LED systems can spur economic development as well -- to the tune of two million potential new jobs, a study says.

The researchers analysed how the transition from polluting fuel-based lighting to solar-LED lighting would impact employment and job creation.

"People like to talk about making jobs with solar energy, but it's rare that the flip side of the question is asked -- how many people will lose jobs who are selling the fuels that solar will replace," said researcher Evan Mills from Lawrence Berkeley National Laboratory (Berkeley Lab).

The University of California manages Berkeley Lab for the US Department of Energy's Office of Science.

"We set out to quantify the net job creation. The good news is, we found that we will see many more jobs created than we lose," Mills noted.

The findings were published in the journal Energy for Sustainable Development.

There are about 274 million households worldwide that lack access to electricity.

But Mills' study focused on the "poorest of the poor", or about 112 million households, largely in Africa and Asia, that cannot afford even a mini solar home system, which might power a fan, a few lights, a phone charger, and a small TV.

Mills found that fuel-based lighting today provides 150,000 jobs worldwide. 

Because there is very little data in this area, his analysis is based on estimating the employment intensity of specific markets and applying it to the broader non-electrified population. He also drew on field observations in several countries to validate his estimates.

He did a similar analysis for the emerging solar-LED industry and found that every one million of these lanterns provides an estimated 17,000 jobs.

These values include employees of these companies based in developing countries but exclude upstream jobs in primary manufacturing by third parties such as those in factories in China. 

Assuming a three-year product life and a target of three lanterns per household, this corresponded to about two million jobs globally, more than compensating for the 150,000 jobs that would be lost in the fuel-based lighting marke, the study said.

Furthermore, Mills' research found that the quality of the jobs would be much improved. 

"With fuel-based lighting a lot of these people are involved in the black market and smuggling kerosene over international borders, and child labour is often involved in selling the fuel," he said. 

"These new solar jobs will be much better jobs -- they're legal, healthy, and more stable and regular," he added.

The new jobs span the gamut, from designing and manufacturing products to marketing and distributing them.