Knowledge Update

​New York, July 12 (IANS) The pigment that gives spinach and other plants their green colour may improve doctors' ability to examine the inner workings of the human body to enable them examine more closely for gastrointestinal illnesses, a study has revealed.

The study published in the journal Advanced Materials describes how chlorophyll-based nano-particles suspended in liquid are an effective imaging agent for the gut.

The medical imaging drink, developed to diagnose and treat gastrointestinal illnesses, is made of concentrated chlorophyll -- the pigment that gives spinach and other plants their green colour, said the study.

"Our work suggests that this spinach-like nanoparticle juice can help doctors get a better look at what is happening inside the stomach, intestines and other areas of the GI tract," said Jonathan Lovell, Assistant Professor in the School of Engineering and Applied Sciences at State University of New York (SUNY) at Buffalo, New York.

To examine the gastrointestinal tract, the researchers used X-rays, magnetic resonance imaging or ultrasounds. The researchers also performed endoscopies in which a tiny camera attached to a thin tube is inserted into the patient's body.

The study focuses on Chlorophyll -- a pigment found in spinach and other green vegetables that is essential to photosynthesis.

The researchers removed magnesium from Chlorophyll in a process which alters the pigment's chemical structure to form another edible compound called pheophytin. Pheophytin plays an important role in photosynthesis, acting as a gatekeeper that allows electrons from sunlight to enter plants.

Next, they dissolved pheophytin in a solution of soapy substances known as surfactants. The researchers were then able to remove nearly all of the surfactants, leaving nearly pure pheophytin nanoparticles.

The drink, when tested in mice, provided imaging of the gut in three modes: photoacoustic imaging, fluorescence imaging and positron emission tomography (PET).

"The veggie juice allows for techniques that are not commonly used today by doctors for imaging the gut like photoacoustic, PET, and fluorescence," said Lovell.​

​New York, July 12 (IANS) Scientists, including one of Indian-origin, have discovered that eyes could help them see progression of Alzheimer's disease even before the onset of symptoms.

The research may help overcome a major roadblock in the development of therapies for the brain disorder characterised by memory impairment.

Looking through the eye to see the brain is a key advantage of the new technology. 

"The retina of the eye is not just 'connected' to the brain -- it is part of the central nervous system," said author Swati More of the University of Minnesota.

While the brain and retina undergo similar changes due to Alzheimer's disease, "unlike the brain, the retina is easily accessible to us, making changes in the retina easier to observe", More said.

The study builds upon previous work in cells by detecting changes in the retina of mice predisposed to develop Alzheimer's.

"We saw changes in the retinas of Alzheimer's mice before the typical age at which neurological signs are observed," said More. 

"The results are close to our best-case scenario for outcomes of this project," she noted.

To test the effectiveness of the new technology in humans, researchers are scheduled to start clinical trials this month, according to the study published in the journal Investigative Ophthalmology & Visual Science (IOVS).

Early detection of Alzheimer's is critical for two reasons. 

"First, effective treatments need to be administered well before patients show actual neurological signs," one of the study authors Robert Vince from University of Minnesota noted.

"Second, since there are no available early detection techniques, drugs currently cannot be tested to determine if they are effective against early Alzheimer's disease. An early diagnostic tool like ours could help the development of drugs as well," Vince explained.​

​New York, July 12 (IANS) Girl Scouts and their parents have reported increase in energy-saving behaviours after the children participated in an intervention programme, revealed a study.

According to the study published in the journal 'Nature Energy', the researchers found that the increased energy-saving behaviour continued for more than seven months after the trial programme ended. 

The study also suggested that these kinds of educational programmes could have a significant and lasting impact on familys' energy consumption.

They also found that the intervention had an effect on parents' energy-saving behaviour for more than eight months.

"Children are a critical audience for environmental programmes, because their current behaviour likely predicts future behaviour. By adopting energy-saving behaviours now and engaging family and community members in such efforts, children can play an important role in bringing about a more sustainable future," said Hilary Boudet, Assistant Professor, Oregon State University.

For the study, the researchers developed a programme called Girls Learning Environment and Energy (GLEE) which offered two interventions designed to promote energy-saving behaviours either at home or in food and transportation decisions. 

Using a randomized control trial, the 318 participating girls, all fourth- and fifth-graders were randomly assigned to one of the programmes.

In 50 to 60-minute lessons once a week for five weeks, the Girl Scouts learned about different ways to save energy in their assigned intervention group and participated in activities designed to support the lessons.

The researchers estimated that the reported behaviour changes associated with the home energy savings intervention represent an annual household energy savings of approximately 3-5 per cent immediately following the intervention and 1-3 per cent at follow-up.

Girls participating in the food and transportation intervention also reported a significant increase in energy-saving behaviour at the end of the programme, but there was no significant change noted at the seven-month follow-up or among parents.​

New York, July 12 (IANS) In a major breakthrough, scientists have successfully restored vision in mice affected by glaucoma-like condition.

The unprecedented, if partial, restoration could pave the way to future work that enables blind people to see, the study said.

Cataracts can often be surgically removed, but there's no cure for glaucoma, said the study's senior author Andrew Huberman, Associate Professor of Neurobiology at Stanford University School of Medicine

Glaucoma, caused by excessive pressure on the optic nerve, affects nearly 70 million people worldwide. 

Vision loss due to optic-nerve damage can also accrue from injuries, retinal detachment, pituitary tumors, various brain cancers and other sources.

In experiments with mice described in a study published online in the journal Nature Neuroscience, the scientists reported regenerating severed nerves responsible for conveying visual information from the eye to the brain, thereby re-establishing the connection between their eyes and brain.

The mice were tested three weeks later after the experiment for their ability to respond to certain visual stimuli.

However, even mice whose behaviour showed restored vision on some tests failed other tests that probably required finer visual discrimination, Huberman said, suggesting the the restoration of vision in the animals was only partial.

The study was conducted in collaboration with researchers at University of California-San Diego, Harvard University and Utah State University.​

​New York, July 9 (IANS) Scientists may finally have an explanation for why some galaxies stop creating stars after a team of astrophysicists painstakingly analysed around 70,000 galaxies to understand the forces influencing star formation activity in them.

The international research team, led by researchers from the University of California, Riverside, combed through available data from the COSMOS UltraVISTA survey that give accurate distance estimates for galaxies over the past 11 billion years, and focused on the effects of external and internal processes that influence star creation in galaxies.

The processes that cause galaxies to "quench", that is, cease star formation, are not well understood and constitute an outstanding problem in the study of the evolution of galaxies. 

"By using the observable properties of the galaxies and sophisticated statistical methods, we show that, on average, external processes are only relevant to quenching galaxies during the last eight billion years," said study lead author Behnam Darvish from the University of California.

"On the other hand, internal processes are the dominant mechanism for shutting off star-formation before this time, and closer to the beginning of the universe," he added.

External processes include drag generated from an infalling galaxy within a cluster of galaxies, multiple gravitational encounters with other galaxies and the dense surrounding environment and the halting of the supply of cold gas to the galaxy.

Internal mechanisms include the presence of a black hole and "stellar outflow" (for example, high-velocity winds produced by massive young stars and supernovae that push the gas out of the host galaxy).

The finding, published recently in the Astrophysical Journal, gives astronomers an important clue towards understanding which process dominates quenching at various cosmic times. 

As astronomers detect quenched non-star-forming galaxies at different distances (and therefore times after the Big Bang), they now can more easily pinpoint what quenching mechanism was at work.​

​London, July 10 (IANS) Immunotherapy has the potential to reduce the risk of heart disease in patients suffering with rheumatoid arthritis, finds a study.

Rheumatoid arthritis is an autoimmune disease in which cytokines such as tumour necrosis factor-alpha (TNFI) and interfero-gamma (IFN), which normally protect the body, attack healthy cells

The findings showed that the combination of two anticytokines containing extra-low doses of antibodies against TNFI and IFN could improve the efficacy of standard rheumatoid arthritis therapy and decrease heart disease risk.

"In rheumatoid arthritis, patients have painful and inflamed joints. They are also at increased cardiovascular risk, particularly if their rheumatoid arthritis is not controlled," said Aida Babaeva, Professor at Volgograd State Medical University in Russia.

Further, the patients taking the combination of anticytokines had a lower rheumatoid arthritis disease activity score, as measured by the DAS28,2 and more dramatic decreases in IL-1, IL-6 and TNF alpha than the group on standard therapy alone.

The incidence of cardiovascular events (unstable angina, severe hypertensive crisis, and deterioration of chronic heart failure) was more than double in the group on conventional disease-modifying drugs alone (37 per cent) compared to those also taking the combination of anticytokines (13 per cent).

"Our findings suggest that the decreased rheumatoid arthritis disease activity with the combination of anticytokines translates into decreased cardiovascular risk," Babaeva said.

Rheumatoid arthritis is also associated with dysfunction of the blood vessel lining (called endothelium), which leads to lipid accumulation in the artery wall, plaque formation and atherosclerosis.

"Thus, decreasing disease activity may also reduce cardiovascular risk by slowing down or halting these processes," Babaeva added.

For the study, the team included 68 patients who had suffered from active rheumatoid arthritis for at least five years.

Patients were randomised to receive the combination of anti-TNF alpha and anti-IFN gamma plus standard disease-modifying therapy (38 patients) or placebo plus standard therapy (30 patients).

We recommend this new approach for preventing cardiovascular events in patients with moderate disease activity who are not receiving the standard biologics and who do not have severe complications."

The research was presented at the Frontiers in CardioVascular Biology (FCVB) 2016 in Italy, recently.​

​London, July 10 (IANS) Humans and other terrestrial animals learn how to walk in similar ways, finds an interesting study.

"We look at the emergence of walking behaviours in both human babies and infant animals, as they develop," said lead author Nadia Dominici from VU University in Netherlands.

Movements such as walking are created from the flexible combination of a small set of groups of muscles that simplify the control of locomotion, called "locomotor primitives".

The findings showed that human babies are born with just two walking primitives: the first directs the legs to bend and extend; the second commands the baby's legs to alternate -- left, right, left, right -- in order to move forward.

To walk independently, babies learn two more primitives, which is to handle balance control -- step timing and weight shifting.

These primitives are unexpectedly alike across different animals -- including rats that the study explored.

"Despite all of the differences in body structure and evolution, locomotion in several animal species could start from common primitives, maybe even stemming from a common ancestral neural network," Dominici added.

Babies are born with an instinct for walking and these are reflected when the child is held near to the floor.

The primitive stepping reflex displayed by the child shows the natural "walking" instinct, which becomes the foundation on which children build an independent walking motion, said the paper.

Understanding these first steps can improve the rehabilitation of patients recovering from spinal cord injury, and children with cerebral palsy, the researchers concluded.​

​London, July 10 (IANS) Norwegian researchers have ventured to delve into why people tend to perceive affinities between sound and body motion when experiencing music -- and agreed that it is all rooted in human cognition.

Researchers from the University of Oslo explored the theory behind the relationship between musical sound and body movement -- the so-called 'motor theory of perception'. 

They explored the relationship between musical sound and body movement -- and came up with results that showed these similarity relationships are deeply rooted in human cognition. 

The results indicated a fair amount of similarity among the participants' gestures, particularly between the vertical positioning of their hands and the pitch of the sound, according to the study published by the Journal of New Music Research.

For the study, the participants were played three-second sounds that varied in pitch and other musical qualities and were asked to trace the sounds in the air using motion capture technology. 

"Music-related motion -- both sound producing and sound accompanying -- leaves a trace in our minds and could be thought of as a kind of shape representation, one intimately linked to our experience of the salient features of musical sound," said Professor Rolf Inge Godoy of the University of Oslo.

In general, some sound features such as rhythm and texture seem to be strongly related to movement while others, such as dissonance, have a weaker sound-motion relationship. 

As a result, the researchers intend to focus their future work on researching large-scale statistical sound-motion feature correlations, providing us with more data on sound-motion similarity relationships in all kinds of musical experience.

"The basic notion here is that images of sound-producing and other sound-related motion are actively re-created in listening and in musical imagery, hence the idea that motor theory could be the basis for the similarities between sound and body movement when we experience music,” added Godoy.

Although links between musical sound and motion can be readily observed, the researchers argue that a more systematic knowledge of them is required.

In order to perceive something, one must actively simulate the motion associated with the sensory impressions.

So, when one listens to music, the person tends to mentally simulate the body movements that have gone into producing the sound. Thus the experience of a sound entails a mental image of a body motion.​

​Ottawa, July 10 (IANS) Coffee lovers who like to attend rock music concerts or work at airports should be cautious as a recent study indicates that caffeine has a serious impact on hearing.

According to a research by the McGill University in Canada, regular caffeine consumption can greatly impede hearing recovery from loud noise, even making the damage permanent, Xinhua news agency reported.

"When the ear is exposed to loud noise, it can suffer from a temporary hearing reduction, also called auditory temporary threshold shift. This disorder is usually reversible in the first 72 hours after the exposure, but if symptoms persist, the damage could become permanent," said Dr Faisal Zawawi, an otolaryngologist at McGill.

The researchers found this impact through an experiment on guinea pigs. They grouped the pigs and tested them in environments of noise without coffee, and noise with coffee.

The noise the animals were exposed to for one hour per day is similar as what people hear at a rock concert. After eight days, significant difference of hearing loss is recorded between the two groups, according to the research team.

In 2015, the European Food Safety Authority published an advice that caffeine intakes from all sources up to 400 mg per day and single doses of 200 mg might be safe for adults in the general population.

But the McGill research suggests that exposure to loud noises coupled with daily consumption of 25 mg of caffeine may have a clear negative impact on hearing recovery.​

New York, July 8 (IANS) A study of numerous seasonal dark streaks called "recurring slope lineae" or RSLs found at a canyon network on Mars has offered important clues that liquid water could be present on the Red Planet.

Water pulled from the atmosphere by salts, or mechanisms with no flowing water involved, remain possible explanations for the occurrence of RSLs in part of the Valles Marineris region near Mars' equator.

"There are so many of them, it's hard to keep track," said study led author Matthew Chojnacki from the University of Arizona.

"The occurrence of recurring slope lineae in these canyons is much more widespread than previously recognised. As far as we can tell, this is the densest population of them on the planet, so if they are indeed associated with contemporary aqueous activity, that makes this canyon system an even more interesting area than it is just from the spectacular geology alone," he added.

The team examined the geological context of canyonland RSL sites and also calculated how much water would need to be present if the streaks are due to liquid water seeping through a thin surface layer to darken the ground.

Many of the sites where RSLs were previously identified are on inner walls of impact craters. At that type of site, a conceivable explanation could be that an extensive underground layer holding water was punctured by the crater-forming impact long ago and still feeds warm-season flows.

If it is seeping water that darkens RSLs, the amount of liquid water required each year to form the streaks in the studied portion of Valles Marineris would total about 10 to 40 Olympic-size swimming pools (about 30,000 to 100,000 cubic metres), the researchers estimate. 

However, no such underground layer fits the ridge or peak shapes at several of the RSL sites in the new study.

Another possible mechanism previously proposed for RSLs is that some types of salts so strongly pull water vapour out of the Martian atmosphere that liquid brine forms at the ground surface. 

The new study results, reported recently by NASA, bolsters the link between RSL and salts. Some sites bear bright, persistent streaks near the dark, seasonal ones. The bright streaks might result from salt left behind after evaporation of brine.

"There do seem to be more ways atmosphere and surface interact in the canyons than in blander topography, such as clouds trailing out of the canyons and low-lying haze in the canyons," Chojnacki said.

Another factor added by the new study is that RSLs not only darken the surface, but are also associated with material moving downslope. The research documents slumping and other three-dimensional changes at some RSL sites, occurring seasonally in tandem with the streaks.​