Knowledge Update

Toronto, May 16 (IANS) For decades, scientists have fiercely debated whether rapid eye movement sleep -- the phase where dreams appear -- is directly involved in memory formation. Now, a study provides evidence that this is indeed the case.

Poor sleep quality is increasingly associated with the onset of various brain disorders such as Alzheimer's and Parkinson's disease.

Results from this study, published in the journal Science, suggest that disruption in this important phase of sleep may contribute directly to memory impairment observed in Alzheimer's disease, the researchers said.

"We were able to prove for the first time that REM sleep is indeed critical for normal spatial memory formation in mice," said study co-author Sylvain Williams, professor at McGill University in Montreal, Canada.

This phase of sleep is understood to be a critical component of sleep in all mammals, including humans.

For the study, the researchers used optogenetics, a recently developed technology that enables scientists to target precisely a number of neurons and control their activity by light.

"We chose to target neurons that regulate the activity of the hippocampus, a structure that is critical for memory formation during wakefulness and is known as the 'GPS system' of the brain," Williams said.

To test the long-term spatial memory of mice, the scientists trained the rodents to spot a new object placed in a controlled environment where two objects of similar shape and volume stand. 

Mice spend more time exploring a novel object than a familiar one, showing their use of learning and recall. 

When these mice were in REM sleep, however, the researchers used light pulses to turn off their memory-associated neurons to determine if it affects their memory consolidation. 

The next day, the same rodents did not succeed the memory task learned on the previous day. Compared to the control group, their memory seemed erased, or at least impaired.

"Silencing the same neurons for similar durations outside REM episodes had no effect on memory. This indicates that neuronal activity specifically during REM sleep is required for normal memory consolidation," study's lead author Richard Boyce from McGill University noted.​

​London, May 14 (IANS) Use by human societies in primordial trade routes has shaped the genetic diversity of the camel, famously known as the 'ship of the desert,' finds a interesting study of its ancient and modern DNA.

Single-humped 'Arabian camels', properly known as 'dromedaries' (Camelus dromedarius), have been fundamental to the development of human societies, providing food and transport in desert countries, for over 3000 years.

Researchers analysed genetic information from a sample of 1,083 living dromedaries from 21 countries across the world.

The findings showed that they were genetically very similar, despite populations being hundreds of miles apart.

Centuries of cross-continental trade caused this "blurring" of genetics, the researchers explained.

"Our analysis of this extensive dataset actually revealed that there is very little defined population structure in modern dromedaries. We believe this is a consequence of cross-continental back and forth movements along historic trading routes," said Olivier Hanotte, professor at Nottingham University in Britain.

"Our results point to extensive gene flow which affects all regions except East Africa where dromedary populations have remained relatively isolated," Hanotte added.

For the research, published in the journal Proceedings of the National Academy of Science, the team combined an examination of ancient DNA sequences from bone samples from early-domesticated dromedaries from 400-1870 AD and wild ones from 5,000-1,000 BC to reveal for the first time ever a historic genetic picture of the species.

"The genetic diversity we have discovered underlines the animal's potential to adapt sustainably to future challenges of expanding desert areas and global climate change," noted Faisal Almathen from King Faisal University in Saudi Arabia.

The dromedary continues to be a vital resource in trade and agriculture in hot, dry areas of the world, providing transport, milk and meat where other species would not survive. ​

​Washington, May 14 (IANS) The local atmosphere in Mars is clear in winter, dustier in spring and summer, and windy in autumn, show measurements by NASA's Curiosity rover that has completed recording environmental patterns through two full cycles of Martian seasons.

Curiosity this week completed its second Martian year since landing inside Gale Crater nearly four years ago. The repetition helps distinguish seasonal effects from sporadic events, NASA's Jet Propulsion Laboratory said in a statement.

Each Martian year -- the time it takes the Red Planet to orbit the sun once -- lasts 687 Earth days. 

Measurements of temperature, pressure, ultraviolet light reaching the surface and the scant water vapour in the air at Gale Crater show strong, repeated seasonal changes, the statement added.

Monitoring the modern atmosphere, weather and climate fulfills a Curiosity mission goal supplementing the better-known investigations of conditions billions of years ago. 

Back then, Gale Crater had lakes and groundwater that could have been good habitats for microbes, if Mars has ever had any. 

Today, though dry and much less hospitable, environmental factors are still dynamic, the statement added.

Curiosity measured air temperatures from 15.9 degrees Celsius on a summer afternoon, to minus 100 degrees Celsius on a winter night. 

"Curiosity's weather station has made measurements nearly every hour of every day, more than 34 million so far," said Curiosity project scientist Ashwin Vasavada of NASA's Jet Propulsion Laboratory, Pasadena, California. 

"The duration is important, because it's the second time through the seasons that lets us see repeated patterns," Vasavada noted.

The similar tilts of Earth and Mars give both planets a yearly rhythm of seasons. But some differences are great, such as in comparisons between day and night temperatures.

Even during the time of the Martian year when temperatures at Gale Crater rise above freezing during the day, they plummet overnight below minus minus 90 degrees Celsius, due to the thin atmosphere. 

Also, the more-elliptical orbit of Mars, compared to Earth, exaggerates the southern-hemisphere seasons, making them dominant even at Gale Crater's near-equatorial location.

"Mars is much drier than our planet, and in particular Gale Crater, near the equator, is a very dry place on Mars," Germán Martinez, Curiosity science-team collaborator at the University of Michigan, Ann Arbor. 

"The water vapor content is a thousand to 10 thousand times less than on Earth," Martinez said.

While continuing to study the modern local environment, Curiosity is investigating geological layers of lower Mount Sharp, inside Gale Crater, to increase understanding of ancient changes in environmental conditions, NASA said.​

​Brussels, May 15 (IANS) Michael Gillon and the team from the University of Liege started their research project five years ago. Only in September last year they discovered three planets orbiting around a nearby dwarf star known as Trappist 1.

As the size and temperatures of these three "red worlds" were comparable to the Earth and other planets from our solar system, it could be the best place for finding life, Xinhua news agency quoted Belgian scientists as saying.

"We are looking for planets that could have on their surfaces the conditions like on Earth and maybe host life," said Michael Gillon, a researcher.

The study showed two of the researched planets have orbital periods of about 1.5 days and 2.4 days respectively. Orbiting time of the third one is around 10 days, Gillon said.

"We are already preparing the next phase which will be the most interesting. It is the James Webb space telescope, which is a very big space telescope that will be launching in 2018, so two years from now and with this telescope we will be able to study atmosphere. So, currently we are trying to measure the masses of the planet," he said.

Scientists from Belgium cooperate with international researchers from the US and Britain. They mainly work through the internet system connected to one of the prototype telescope based in Chile.

To detect potentially habitable planets researchers use a so-called transit method. They observe specific stars and trying to catch the planet that will pass in front of them.

"We made this programme on our small robotic telescope Trappist which is in Chile as a prototype for our more ambitious project which is called Speculoos ... It will use bigger telescopes with more sensitive instruments to explore more," he added.

With current Trappist telescope scientists were able to observe only 60 targets. With Speculoos the scope will be wider, up to 500 objects.​

Beijing, May 15 (IANS) At times when we want something and things are unavailable, we end up picking the closest substitute. But a new study suggests that we would be better off and happy picking something that is not-so-similar alternative.

The findings indicated that even though people tend to prefer the option that is most similar to the item they cannot have, they are likely to be more satisfied with the option that diverges a bit.

"Intuition suggests the next best thing is the thing most like the thing we want, but our findings suggest this intuition is wrong," said lead study author Young Eun Huh of Hong Kong University of Science and Technology.

The intuition is wrong because it fails to account for the mental comparisons we end up making between what we wanted and what we ended up with.

"The thing that is most like what we want is also easiest to compare to what we are craving and we are likely to notice that it's worse than what we want," Huh explains.

The study, published in the journal of the Association for Psychological Science, examined 101 participants with different sets of foods on how making choices involving tradeoffs influences how satisfied we feel with those choices through a series of four experiments.

Each set included one desired food and two substitute options.

The majority of participants who tasted a piece of gourmet chocolate chose chocolate-covered peanuts over a granola bar as their preferred substitute; in fact, the stronger their craving for the chocolate, the more likely they were to choose the chocolate peanuts.

The findings provide insight into how we can maximise our satisfaction with the food we eat, given the choices available.

"Life often presents all of us with situations in which we can't have exactly what we want: We might not get our dream job or be able to afford the perfect vacation," the researchers noted.​

​Washington, May 13 (IANS) In a first, the US space agency has directly observed fundamental process of nature after sending four spacecraft through an invisible whirlpool in space called magnetic reconnection, like sending sensors up into a hurricane.

The findings showed that magnetic reconnection is dominated by the physics of electrons -- thus providing crucial information about what powers this fundamental process in nature.

Magnetic reconnection is one of the prime drivers of space radiation and a key factor in the quest to learn more about our space environment and protect our spacecraft and astronauts.

The effects of this sudden release of particles and energy -- such as giant eruptions on the sun or radiation storms in near-Earth space -- have been observed throughout the solar system and beyond.

"We developed a mission called the Magnetospheric Multiscale mission (MMS) that for the first time would have the precision needed to gather observations in the heart of magnetic reconnection," said Jim Burch, principal investigator at the Southwest Research Institute in San Antonio, Texas.

"We received results faster than we could have expected. By seeing magnetic reconnection in action, we have observed one of the fundamental forces of nature," he added.

MMS is made of four identical spacecraft that were launched in March 2015.

They fly in a pyramid formation to create a full 3D map of any phenomena they observe.

On October 16, 2015, the spacecraft travelled straight through a magnetic reconnection event at the boundary where Earth's magnetic field bumps up against the sun's magnetic field.

In only a few seconds, the 25 sensors on each of the spacecraft collected thousands of observations.

"One of the mysteries of magnetic reconnection is why it's explosive in some cases, steady in others, and in some cases, magnetic reconnection doesn't occur at all," noted Tom Moore, mission scientist for MMS at NASA's Goddard Space Flight Centre in Greenbelt, Maryland.

At the edges of Earth's magnetic environment - the magnetosphere - such events allow solar radiation to enter near-Earth space.

With this new set of observations, MMS tracked what happens to electrons during magnetic reconnection.

As the four spacecraft flew across the magnetosphere's boundary, they flew directly through what's called the dissipation region where magnetic reconnection occurred.

The observations showed the electrons shot away in straight lines from the original event at hundreds of miles per second, crossing the magnetic boundaries that would normally deflect them.

Once across the boundary, the particles curved back around in response to the new magnetic fields they encountered, making a U-turn.

By watching these electrons, MMS made the first observation of the predicted breaking and interconnection of magnetic fields in space.

"The data showed the entire process of magnetic reconnection to be fairly orderly and elegant," said Michael Hesse, space scientist at Goddard, in a paper published in the journal Science.

There does not seem to be much turbulence present, or at least not enough to disrupt or complicate the process.

This suggests that it is the physics of electrons that is at the heart of understanding how magnetic field lines accelerate the particles.

Since its launch, MMS has made more than 4,000 trips through the magnetic boundaries around Earth, each time gathering information about the way the magnetic fields and particles move.​

​New York, May 13 (IANS) A sixth sense can keep a driver safe even when he or she is absent-minded or emotionally-charged but not when they text while on the wheels, a team of US researchers has found.

The researchers from University of Houston (UH) and the Texas A&M Transportation Institute (TTI) said that in all three interventions, the drivers' handling of the wheel became jittery with respect to normal driving but
texting while driving is too dangerous.

While this jittery handling resulted in significant lane deviations and unsafe driving in the case of texting distractions, in the case of absent-minded and emotionally charged distractions, jittery steering resulted in straighter trajectories with respect to a normal drive and safer driving.

"A likely explanation for this paradox is the function performed by a part of the brain called the Anterior Cingulate Cortex (ACC) -- known to automatically intervene as an error corrector when there is conflict," said Ioannis Pavlidis from University of Houston.

"In this case, the conflict comes from the cognitive, emotional and sensorimotor, or texting, stressors. This raises the levels of physiological stress, funneling 'fight or flight' energy to the driver's arms, resulting in jittery handling of the steering wheel," Pavlidis added in a university statement.

According to him, brain's ACC automatically counterbalances any strong jitter to the left with an instant equally strong jitter to the right and vice versa.

For ACC to perform this corrective function, it needs support from the driver's eye-hand coordination loop. 

"The driver's mind can wander and his or her feelings may boil but a sixth sense keeps a person safe at least in terms of veering off course," Pavlidis noted. 

What makes texting so dangerous is that it wreaks havoc into this sixth sense. 

"Self-driving cars may bypass this and other problems, but the moral of the story is that humans have their own auto systems that work wonders, until they break," the authors noted.

The work was funded, in part, by the Toyota Class Action Settlement Safety Research and Education Programme.​

Toronto, May 13 (IANS) Opening doors to development of new drugs to control weight gain and obesity, researchers have identified brain cells that play a crucial role in appetite control.

Although these cells -- known as NG2-glia cells -- exist within different parts of the brain, it is those found in a specific brain structure called the median eminence that are crucial to weight control, the findings showed.

"About 20 years ago there was a big step forward in our understanding of obesity when researchers discovered that our appetite is controlled by a key molecule called leptin. Leptin is a hormone which is produced by our fat cells, and is delivered by the blood to the brain to signal the brain that we are full and can stop eating," explained one of the researchers Maia Kokoeva from McGill University in Monthreal, Canada.

"But even though receptors for leptin were discovered soon after in the hypothalamus, a brain area that regulates food intake and body weight, it has remained unclear how exactly leptin is detected," Kokoeva noted.

So the researchers set out to explore which brain cells might play a role in the process of leptin sensing and weight gain. 

The answer, it turns out according to the new research, lies in the NG2-glia cells in median eminence.

The median eminence is a brain structure at the base of the hypothalamus. It is a bit like a busy hub or market place through which hormones and molecules of various kinds travel in both directions between the brain and the bloodstream to ensure that the body functions smoothly.

The research team discovered that without a particular group of cells (NG2-glia cells) in place in the median eminence, the leptin receptors in the brain never receive the messages from the body telling it that it is sated.

The findings were published in the journal Cell Metabolism.

The researchers are hopeful that the identification of these cells in the median eminence as crucial elements in body weight and appetite control will pave the way to new targeted anti-obesity approaches directed towards maintaining or raising the NG2-glia population in the median eminence.​

New York, May 13 (IANS) A faint blue galaxy situated about 30 million light years from the Earth and located in the constellation "Leo Minor" can shed new light on birth of the universe.

Astronomers from Indiana University (IU) found that a galaxy nicknamed Leoncino or “little lion” contains the lowest level of heavy chemical elements or “metals” ever observed in a gravitationally bound system of stars.

“Finding the most metal-poor galaxy ever is exciting since it can help contribute to a quantitative test of the Big Bang," said professor John J. Salzer from IU's Bloomington College of Arts and Sciences.

There are relatively few ways to explore conditions at the birth of the universe, but low-metal galaxies are among the most promising.

This is because the current accepted model of the start of the universe makes clear predictions about the amount of helium and hydrogen present during the Big Bang.

The ratio of these atoms in metal-poor galaxies provides a direct test of the model.

To find these low-metal galaxies, however, astronomers must look far from home. 

Our own Milky Way galaxy is a poor source of data due to the high level of heavier elements created over time by “stellar processing,” in which stars churn out heavier elements.

“Low metal abundance is essentially a sign that very little stellar activity has taken place compared to most galaxies,” added Alec S Hirschauer, graduate student in a paper appeared the Astrophysical Journal. 

Leoncino is considered a member of the “local universe,” a region of space within about one billion light years from Earth and estimated to contain several million galaxies.

Aside from low levels of heavier elements, Leoncino is unique in several other ways. 

A so-called “dwarf galaxy,” it's only about 1,000 light years in diameter and composed of several million stars. 

The Milky Way, by comparison, contains an estimated 200 billion to 400 billion stars. 

“We're eager to continue to explore this mysterious galaxy," Salzer noted.​

Abu Dhabi, May 13 (IANS/WAM) A UAE researcher has contributed to the discovery of a new species of ant, according to a paper published in the Journal of Natural History.

The study, led by Mostafa R. Sharaf of the College of Food and Agriculture Sciences at Saudi Arabia's King Saud University, describes the ant species, whose scientific name is Lepisiota omanensis, as being remarkable because of "its exceptionally long, acute and strongly curved propodeal spines".

The paper describes the new species on the basis of five specimens, one of which was collected in Oman in 2012, two of which were collected in Ain Al Waal in UAE in 2014, and two in Oman in March this year.

The UAE researcher, Huw Roberts, from the Emirates University, said: "I have so far recorded well over 400 species of insects, most of which have been identified from specimens by specialists from around the world."

"This discovery shows that we still have much to learn about the wildlife and biodiversity of the UAE," he added.​