Knowledge Update

​Toronto, March 18 (IANS) Opening up a whole new paradigm for treating or even indefinitely postponing the onset of osteoporosis, researchers have found that a single injection of stem cells could potentially restore the normal bone structure in those affected by the condition in which bones become brittle as a result of loss of tissue.

With age-related osteoporosis, the inner structure of the bone diminishes, leaving the bone thinner, less dense, and losing its function. 

The disease is responsible for an estimated 8.9 million fractures per year worldwide.

But how can an injection of stem cells reverse the ravages of age in the bones?

The researchers earlier demonstrated a causal effect between mice that developed age-related osteoporosis and low or defective mesenchymal stem cells (MSCs) in these animals.

"We reasoned that if defective MSCs are responsible for osteoporosis, transplantation of healthy MSCs should be able to prevent or treat osteoporosis," said senior author of the study William Stanford, professor at the University of Ottawa in Canada.

To test that theory, the researchers injected osteoporotic mice with MSCs from healthy mice.

Stem cells are "progenitor" cells, capable of dividing and changing into all the different cell types in the body. 

Able to become bone cells, MSCs have a second unique feature, ideal for the development of human therapies -- these stem cells can be transplanted from one person to another without the need for matching (needed for blood transfusions, for instance) and without being rejected.

After six months post-injection, a quarter of the life span of these animals, the osteoporotic bone had astonishingly given way to healthy, functional bone.

The findings were published in the journal Stem Cells Translational Medicine.

"We had hoped for a general increase in bone health," study co-author John Davies, professor at the University of Toronto, said. 

"But the huge surprise was to find that the exquisite inner "coral-like" architecture of the bone structure of the injected animals--which is severely compromised in osteoporosis--was restored to normal," Davies noted.

While there are currently no human stem cell trials looking at a systemic treatment for osteoporosis, the long-range results of the study point to the possibility that as little as one dose of stem cells might offer long-term relief.​

​New York, March 18 (IANS) A new equation developed by scientists can predict more accurately your walking energy expenditure, thus replacing the leading standardised equations used for close to half a century that were based on the assumption that one size fits all.

"Our new equation is formulated to apply regardless of the height, weight and speed of the walker. It's appreciably more accurate," said Lindsay Ludlow, a researcher at the Southern Methodist University (SMU) in Dallas.

The equation developed by SMU scientists, which was recently described in in the Journal of Applied Physiology, is about four times more accurate for adults and children together, and about two to three times more accurate for adults only, Ludlow said.

"The economy of level walking is a lot like shipping packages -- there is an economy of scale," said Peter Weyand, a study co-author. "Big people get better gas mileage when fuel economy is expressed on a per-pound basis," he added.

The research comes at a time when greater accuracy combined with mobile technology, such as wearable sensors, is increasingly being used in real time to monitor the body's status. 

The researchers note that some devices use the old standardised equations, while others use a different method to estimate the calories burned.​

New York, March 18 (IANS) Having more ideal cardiovascular health is linked with better brain processing speed and is more likely to prevent the decline in brain function that sometimes accompanies ageing, according to a study.

The researchers from the University of Miami and the Columbia University used the American Heart Association's "Life's Simple Seven" definition of cardiovascular health, which includes tobacco avoidance, ideal levels of weight, physical activity, healthy diet, blood pressure, cholesterol and glucose.

"Achieving the health metrics of Life's Simple 7 is associated with a reduced risk of strokes and heart attacks, even among the elderly," said study lead author Hannah Gardener from the University of Miami.

"The finding that they may also impact cognitive, or brain function underscores the importance of measuring, monitoring and controlling these seven factors by patients and physicians," Gardener added.

At the beginning of the study, published recently in Journal of the American Heart Association, 1,033 participants were tested for memory, thinking and brain processing speed.

Brain processing speed measures how quickly a person is able to perform tasks that require focused attention. Approximately six years later, 722 participants repeated the cognitive testing, which allowed researchers to measure performance over time.

The researchers found that having more cardiovascular health factors was associated with less decline over time in processing speed, memory and executive functioning, which is associated with focusing, time management and other cognitive skills.

"In addition, further study is needed to identify the age ranges, or periods over the life course, during which cardiovascular health factors and behaviours may be most influential in determining late-life cognitive impairment, and how behavioural and health modifications may influence cognitive performance and mitigate decline over time," Gardener said.​

​London, March 19 (IANS) A source of cosmic rays radiating energies 100 times greater than those achieved at the largest terrestrial particle accelerator -- the Large Hadron Collider at the European Organisation for Nuclear Research (CERN) -- has been found in the innermost region of our Milky Way galaxy.

The source was revealed after a detailed analysis of the data collected by the H.E.S.S. observatory in Namibia, which was published in the latest issue of the journal Nature. 

H.E.S.S. observatory is being run by an international collaboration of 42 institutions in 12 countries and has been mapping the centre of our galaxy in very high energy gamma rays for over the past 10 years.

"Somewhere within the central 33 light years of the Milky Way there is an astrophysical source capable of accelerating protons to energies of about one petaelectronvolt, continuously for at least 1,000 years," said Emmanuel Moulin from the Saclay Nuclear Research Centre in France. 

Cosmic rays with energies up to approximately 100 teraelectronvolts (TeV)1 are produced in our galaxy by objects such as supernova remnants and pulsar wind nebulae. 

Theoretical arguments and direct measurements of cosmic rays reaching the Earth indicate, however, that the cosmic-ray factories in our galaxy should be able to provide particles up to one petaelectronvolt (PeV)2 at least. 

While many multi-TeV accelerators have been discovered in recent years, the search for the sources of the highest energy Galactic cosmic rays has been unsuccessful.

The electrically-charged cosmic rays are strongly deflected by the interstellar magnetic fields that pervade our galaxy. Their path through the cosmos is randomised by these deflections, making it impossible to directly identify the astrophysical sources responsible for their production. 

Thus, for more than a century, the origin of the cosmic rays has remained one of the most enduring mysteries of science.

In analogy to the "Tevatron" -- the first human-built accelerator that reached energies of 1 TeV -- this new class of cosmic accelerator has been dubbed a "Pevatron."

​London, March 19 (IANS) Researchers have found that the blue tit, collared flycatcher and pied flycatcher have the fastest eyesight in the animal kingdom, with their vision being more than twice as fast as humans.

Thought to be the fastest of any vertebrate animal, their remarkable vision system, allows them to see the world around them in slow motion.

“Bird species similar to the blue tit, collared flycatcher and pied flycatcher, both ecologically and physiologically, probably also share the faculty of superfast vision,” said lead researcher Anders Ödeen, lecturer at Uppsala University in Sweden.

The study, published in the journal PLOS ONE, showed that perching birds, or passerines, have eyes with a temporal visual resolution -- precision of a measurement with respect to time -- of up to 146Hz.

It is at least 50Hz faster than any other vertebrate, and well over twice as fast as the 60Hz a human eye can detect, the researchers pointed out adding that this indicates an evolutionary history of natural selection for fast vision in these bird species. 

That the small airborne birds need to detect and track objects whose image moves very swiftly across the retina to be able to see and avoid all branches when they take cover from predators by flying straight into bushes, gives an explanation for their fast vision. 

The findings raise concerns about the welfare of small caged birds, especially those kept in areas with modern low-energy or flickering lighting light, which can cause stress, behavioural disturbances and various forms of discomfort in humans and birds alike.

Yet it appears perching birds may have traded their ultra-sharp vision at the expense of sharpness.

While the record for the sharpest vision still rests with eagles, which can detect finer details than any other animal, perching birds can only see in low resolution.

For the study, the team trained wild-caught birds to receive a food reward by distinguishing between a pair of lamps, one flickering and one shining a constant light. 

Temporal resolution was then determined by increasing the flicker rate to a threshold at which the birds could no longer tell the lamps apart. 

These birds are increasingly often kept in rooms lit with low-energy light bulbs, fluorescent lamps or LED lighting. Many of these flicker at 100 Hz, which is invisible to humans but perhaps not to small birds in captivity.

​New York, March 18 (IANS) Ever wondered how your working memory functions in the brain? A new study finds that bursts of neural activity take place as the brain holds information in mind.When the mind holds a sentence just read or a phone number that one is about to dial, then the individual is engaging a critical brain system known as working memory.
The new study upends the notion that brain cells associated with information fire continuously and instead reveals that as information is held in working memory, neurons -- nerve cells -- fire in sporadic and coordinated bursts."Your brain operates in a very sporadic, periodic way, with lots of gaps in between the information the brain represents," said one of the lead authors Mikael Lundqvist, postdoctoral researcher at the Massachusetts Institute Of Technology (MIT) in the US.

Our brain actually works in a very periodic fashion, sending packets of information around.These cyclical bursts could help the brain to hold multiple items in working memory at the same time, the researchers explained."By having these different bursts coming at different moments in time, you can keep different items in memory separate from one another," added one of the authors Earl Miller, professor at MIT.
It would be worthwhile to look for this kind of cyclical activity in other cognitive functions such as attention, the researchers suggested in the study, published in the journal Neuron.The team recorded neuron activity in animals as they were shown a sequence of three coloured squares, each in a different location. 

Then, the squares were shown again, but one of them had changed colour. The animals were trained to respond when they noticed the square that had changed colour -- a task requiring them to hold all three squares in working memory for about two seconds.

The researchers found that as the items were held in working memory, ensembles of neurons in the prefrontal cortex were active in brief bursts, and these bursts only occurred in recording sites in which information about the squares was stored. The bursting was most frequent at the beginning of the task, when the information was encoded, and at the end, when the memories were read out.​

​Toronto, March 18 (IANS) Some baby monkeys develop faster than others in the same population, and this is best explained by the threat of infanticide they face from adult males, says a study.

"Infanticide occurs in many animals, including carnivores like lions and bears, rodents like mice, and in primates," said lead researcher Iulia Badescu from University of Toronto."Typically, an adult male kills an infant sired by another male so that he can mate with the mother and sire his own infants with her," Badescu noted.
In this study that appeared online in the journal Animal Behaviour, the researchers looked at infant development in wild ursine colobus monkeys. Black-and-white colobus includes several species of medium-sized monkeys found throughout equatorial Africa. 
They have black bodies with white hair that sometimes forms a bushy white beard and sideburns, or can extend down the back like a 'cape' and down the tail.
Colobus babies are born pure white and their coat colour changes to grey after a few weeks before turning black-and-white between two and five months. The researchers were intrigued by the fact that infants varied in the age at which their coats became grey, and then black and white. 

They also realised that these colour transitions were helpful to track the development of the infants, in a non-intrusive fashion.Earlier research at the study site, Boabeng-Fiema Monkey Sanctuary in Ghana, established that some scenarios are more likely to lead to infanticide by males. Groups with multiple males, for example, have more instances of infanticide.

The team observed nine groups of ursine colobus monkeys in the wild over a period of eight years (2007 to 2014). 
"We found that infants facing a greater risk of infanticide developed faster than infants facing lesser risk," Pascale Sicotte, professor at University of Calgary in Canada, explained.​

Tokyo, March 16 (IANS) To understand the effects of microgravity on crystal growth, a team of Japanese researchers has measured the growth of crystals in a specially-designed chamber on board the International Space Station (ISS).
The researchers monitored the very slow growth and dissolution rate -- approximately one centimetre per second of the crystals by a method called laser interferometry.

This was the first time the technique had been used onboard the orbiting international laboratory to measure the growth rate of the crystals at various temperatures.

“We are interested in the growth mechanisms of a space-grown protein crystal -- a lysozyme crystal -- as a model crystal to understand why space-grown crystals sometimes do show better quality than the Earth-grown crystals," explained Tomoya Yamazaki, PhD student in Katsuo Tsukamoto's lab in Tohoku University's department of earth and planetary science in Sendai, Japan.

To observe this, Yamazaki and his colleagues developed unique growth cells suitable for long-term projects for about six months.

For the researchers studying protein crystal growth, that distance was 250 miles up -- the altitude at which the ISS orbits the Earth.

The experimental process, known as NanoStep, was performed in the Japanese Experimental Module (KIBO) of the ISS.

Tsukamoto and his colleagues had previously measured the growth rates of protein crystals under simulated microgravity by using a Russian recoverable satellite and aircraft in parabolic flights.

The researchers took precise measurements of the growth rate of the lysozyme crystals versus their driving force and supersaturation. This also yielded crucial information about the growth mechanism.

Tsukamoto and his colleagues detailed the growth method in the journal Review of Scientific Instruments.

While the researchers expected growth rates of the crystal solution to be slower because of the suppression of solution convection, the results instead showed an increased growth rate.

Extended projects for the researchers using the same apparatus to test the growth of different crystals, such as glucose isomerase crystals, are currently in preparation.​

​New York, March 15 (IANS) Forget the toxic material lithium as researchers from the Massachusetts Institute of Technology (MIT) have come up with an alternative system for generating electricity which harnesses heat and uses no metals or toxic materials for powering smartphones or cars, even deep space missions.

The new approach is based on a discovery announced in 2010 by Michael Strano, the Carbon P. Dubbs professor in chemical engineering at the MIT, and his co-workers.

A wire made from tiny cylinders of carbon known as carbon nanotubes can produce an electrical current when it is progressively heated from one end to the other, for example, by coating it with a combustible material and then lighting one end to let it burn like a fuse.

Now, Strano and his team have increased the efficiency of the process more than a thousandfold and have produced devices that can put out power that can be produced by today's best batteries. 

The researchers, however, caution that it could take some years to develop the concept into a commercialisable product.

“It's actually remarkable that this [phenomenon] hasn't been studied before. The latest experiments show good agreement between theory and experimental results, providing strong confirmation of the underlying mechanism,” said Strano in a paper published in the journal Energy & Environmental Science.

Already, the device is powerful enough to show that it can power simple electronic devices such as an LED light. 

Unlike batteries that can gradually lose power if they are stored for long periods, the new system should have a virtually indefinite shelf life. 

That could make it suitable for uses such as a deep-space probe that remains dormant for many years as it travels to a distant planet and then needs a quick burst of power to send back data when it reaches its destination.

Basically, the effect arises as a pulse of heat pushes electrons through the bundle of carbon nanotubes, carrying the electrons with it like a bunch of surfers riding a wave.

The improvements in efficiency, Strano says, "brings [the technology] from a laboratory curiosity to being within striking distance of other portable energy technologies," such as lithium-ion batteries or fuel cells. 

In their latest version, the device is more than one percent efficient in converting heat energy to electrical energy, the team reports, which is "orders of magnitude more efficient than what's been reported before." 

In fact, the energy efficiency is about 10,000 times greater than that reported in the original discovery paper.

“It took lithium-ion technology 25 years to get where they are” in terms of efficiency, Strano pointed out, whereas this technology has had only about a fifth of that development time. ​

London, March 15 (IANS) Researchers have presented a new model for what dark matter might be, a discovery that can lead scientists to invisible dark matter that is all around us yet no one has ever seen it and no one knows what it really is.

Physical calculations state that approximately 27 percent of the universe is dark matter. Only five percent is the matter of which all known materials consist: from the smallest ant to the largest galaxy.

For decades, researchers have tried to detect this invisible dark matter.

“Maybe it's because we have looked after dark particles in a way that will never be able to reveal them. Maybe dark matter is of a different character and needs to be looked for in a different way,” explained Martin Sloth, associate professor at University of Southern Denmark.

For decades, physicists have been working on the theory that dark matter is light and therefore interacts weakly with ordinary matter.

This means that the particles are capable of being produced in colliders.

This theory's dark particles are called weakly-interacting massive particles (WIMPs), and they are theorised to have been created in an inconceivably large number shortly after the birth of the universe 13.7 billion years ago.

“But since no experiments have ever seen even a trace of a WIMP, it could be that we should look for a heavier dark particle that interacts only by gravity and thus would be impossible to detect directly,” said Sloth.

Sloth and his colleagues call their version of such a heavy particle a PIDM (Planckian Interacting Dark Matter) particle.

Together with postdoc McCullen Sandora from CP3-Origins and postdoc Mathias Garny from CERN, Sloth now presents a new model for what dark matter might be in a paper published in the journal Physical Review Letters.
In their new model, they calculated how the required number of PIDM particles could have been created in the early universe.

“It was possible, if it was extremely hot. To be more precise the temperatures in the early universe must have been the highest possible in the Big Bang theory,” added Sloth.

“If the universe indeed was as hot as calculated in our model, several gravitational waves from the very early childhood of the universe would have been created. We might be able to find out in the near future,” he pointed out.

With this, Sloth refers to a number of planned experiments around the world that will be able to detect signals from very early gravitational waves.

“If these experiments do not detect such signals, then our model will be falsified. Thus gravitational waves can be used to test our model,” he added.

More than 10 different experiments are planned.

The team aims to measure the polarisation of the cosmic background radiation, either from the ground or with instruments sent up in a balloon or satellite to avoid atmospheric disturbances.​