Knowledge Update

​London, July 16 (IANS) Repeated stimulation of muscles can restore movement after a paralytic attack, finds a study that could pave a new opportunity to rehabilitate patients with spinal cord damage.

In the study, two patients with spinal cord injuries caused by trauma received a form of treatment that combined transcranial magnetic stimulation with simultaneous peripheral nerve stimulation repeatedly for nearly six months.

One patient was paraplegic -- paralysed from the knees down, and the other was tetraplegic -- partial or total loss of use of all four limbs and torso --, with some voluntary movement of the hands but no capacity to grasp.

After approximately six months of the stimulation treatment, the paraplegic patient could bend both ankles, and the tetraplegic could grasp an object.

"We observed strengthened neural connections and partial restoration of movement to muscles which the patients were previously entirely unable to use," said Anastasia Shulga, Neurologist, at University of Helsinki in Finland.

The movement restored during the treatment was still present a month after the stimulation treatment had ended.

"This is a case study with two patients only, but we think the results are promising," added Jyrki Makela from Helsinki University Hospital, pointing out that rehabilitation of patients with chronic spinal cord injuries is highly challenging, and new treatment methods are sorely needed.

Long-term stimulation treatment of this type was used for the first time to rehabilitate patients paralysed as a result of a spinal cord injury.

Further study is needed to confirm whether such long-term stimulation can be used in rehabilitation after spinal cord injury or can be used in combination with other therapeutic strategies, the researchers concluded.​

​​​​Toronto, July 16 (IANS) Hypertension is the single major risk factor for stroke, which is a highly preventable medical condition globally, irrespective of age and sex, reveals a study led by an Indian-origin researcher.

Stroke which is caused when poor blood flow to the brain results in cell death, is the leading cause of mortality and disability, particularly in low-income and middle-income countries.

The findings showed that 47.9 per cent of stokes were caused as a result of hypertension whereas physical inactivity caused 35.8 per cent.

"The study confirmed that hypertension is the most important modifiable risk factor in all regions and is therefore the key target in reducing the burden of stroke globally," said Salim Yusuf, Professor at McMaster University in Ontario, Canada.

Poor diet and obesity caused 23.2 per cent and 18.6 per cent of strokes, respectively.

While smoking caused 12.4 per cent, heart diseases was accounted for 9.1 per cent of strokes.

Diabetes resulted in 3.9 per cent and alcohol intake in 5.8 per cent of strokes.

Stress caused 5.8 per cent and lipids 26.8 per cent of strokes.

When combined together, the total for all ten risk factors was 90.7 per cent, which was similar in all regions, age groups and in men and women, the researchers said.

"The wider reach confirms the ten modifiable risk factors associated with 90 per cent of stroke cases in all major regions of the world, young and older and in men and women,” said Martin O'Donnell, Associate Professor at McMaster University.

Further, hypertension was found as the highest reason behind strokes in Southeast Asia (59.6 per cent), whereas in western Europe, North America and Australia it caused 38.8 per cent of strokes.

Alcohol intake was found lowest in western Europe, North America, Australia but at 10.4 per cent and 10.7 per cent it was highest in Africa and south Asia, respectively. Physical inactivity was found as the highest reason of strokes in China.

In addition, ischaemic stroke -- caused by blood clots -- accounted for 85 per cent of strokes and haemorrhagic stroke -- bleeding in the brain -- accounted for 15 per cent of strokes, was found as the two major types of strokes.

"The study included better health education, more affordable healthy food, avoidance of tobacco and more affordable medication for hypertension and dyslipidaemia -- abnormal amount of lipids in the blood -- as global population-level interventions to reduce stroke," Yusuf added. 

Governments, health organisations, and individuals should proactively reduce the global burden of stroke, said the paper published in The Lancet.

For the study, the team included 6000 participants from 22 countries and later an additional 20000 individuals from 32 countries in Europe, Asia, America, Africa and Australia.​

​​Washington, July 16 (IANS) The US space agency is ready to proceed with the final design and construction of its next Mars rover, currently targeted to launch in the summer of 2020 and arrive on the Red Planet in February 2021, NASA said.

The Mars 2020 rover will investigate a region of Mars where the ancient environment may have been favourable for microbial life, probing the Martian rocks for evidence of past life.

"This mission marks a significant milestone in NASA’s Journey to Mars - to determine whether life has ever existed on Mars, and to advance our goal of sending humans to the Red Planet,” said Geoffrey Yoder, Acting Associate Administrator of NASA’s Science Mission Directorate in Washington. 

Throughout its investigation, it will collect samples of soil and rock and cache them on the surface for potential return to Earth by a future mission.

"The Mars 2020 rover is the first step in a potential multi-mission campaign to return carefully selected and sealed samples of Martian rocks and soil to Earth,” Yoder noted.

To reduce risk and provide cost savings, the 2020 rover will look much like its six-wheeled, one-tonne predecessor, Curiosity, which landed on Mars in 2012, but with an array of new science instruments and enhancements to explore Mars as never before, NASA said in a statement.

The Mars 2020 rover will use the same sky crane landing system as Curiosity, but will have the ability to land in a more challenging terrain with two enhancements, making more rugged sites eligible as safe landing candidates, the US space agency pointed out.

The Mars 2020 mission has already passed an extensive review process and a major development milestone.

Once a mission receives preliminary approval, it must go through four rigorous technical and programmatic reviews -- known as Key Decision Points (KDP) to proceed through the phases of development prior to launch. 

Phase A involves concept and requirements definition, Phase B is preliminary design and technology development, Phase C is final design and fabrication, and Phase D is system assembly, testing, and launch. Mars 2020 has just passed its KDP-C milestone.

"Since Mars 2020 is leveraging the design and some spare hardware from Curiosity, a significant amount of the mission's heritage components have already been built during Phases A and B,” George Tahu, Mars 2020 Programme Executive at NASA Headquarters in Washington said. 

"With the KDP to enter Phase C completed, the project is proceeding with final design and construction of the new systems, as well as the rest of the heritage elements for the mission," Tahu added.​

​London, July 16 (IANS) Nearly half of the parents in Britain think heavy social media use is hampering their children's moral development, a British poll revealed on Saturday.

Only 15 per cent of parents thought that popular social media websites such as Facebook provided a positive influence on a young person’s character, said the poll from the Jubilee Centre for Character and Virtues, University of Birmingham.

The team of researchers found that 40 per cent of parents were "concerned" or "extremely concerned" about the negative and potentially harmful impact of social media.

"There are some surprising findings in the poll, not the least the low level of agreement that social media can enhance or support a young person's character or moral development," lead researcher Dr Blaire Morgan said in a university statement.

According to the report, 24 percent of the respondents said forgiveness and self-control were the qualities that were least present in them, followed by honesty (21 per cent), fairness (20 per cent) and humility (18 per cent).

"Sixty percent of parents named anger and hostility as the most negative trait displayed, followed by arrogance (51 per cent), ignorance (43 per cent), bad judgment (41 per cent) and hatred (36 per cent)," the report noted.

Meanwhile, the top five character strengths promoted at least once a month on social media sites were identified as humour (52 per cent), appreciation of beauty (51 per cent), creativity (44 per cent), love (39 per cent) and courage (39 per cent).​

​New York, July 16 (IANS) Turtles developed shells as a tool for burrowing underground to escape harsh climatic conditions, a study has found, contradicting the traditional belief that they used their shells for their protection.

The study was conducted on new fossil material, a 15 cm long specimen of the 260- million-year-old, partially shelled, proto turtle or stem turtle, Eunotosaurus Africanus from the Karoo Basin of South Africa, which indicated that the initiation of rib broadening was an adaptive response to fossoriality. 

Numerous fossorial animal -- one that is adapted to digging and life underground such as the badger -- correlates are expressed throughout Eunotosaurus' skeleton.

These stem turtles indicate that the shell did not evolve for protection, rather adaptation related to digging was the initial impetus in the origin of the shell.

"The earliest beginnings of the turtle shell was not for protection but rather for digging underground to escape the harsh South African environment where these early proto turtles lived," said lead author Tyler Lyson, Paleontologist Denver Museum of Nature & Science in Colorado, US.

The adaptations related to fossoriality likely facilitated movement of stem turtles into aquatic environments early in the groups' evolutionary history, and this ecology may have played an important role in stem turtles surviving the Permian/Triassic extinction event that occurred about 252-million-years ago, said the paper published in the journal Current Biology.

Further, the developmental and fossil data showed that one of the first steps toward the shelled body plan was broadening of the ribs.

The distinctly broadened ribs -- that play a crucial role in ventilating the lungs and are used to support the body during locomotion -- has a serious impact on both breathing and speed in these quadrupedal animals. 

These broadened ribs stiffen the torso, which shortens an animals stride length and slows it down, interfering with breathing.

"We knew from both the fossil record and observations how the turtle shell develops into modern turtles that one of the first major changes toward a shell was the broadening of the ribs," Lyson added.

The broad ribs of Eunotosaurus provide an intrinsically stable base on which to operate a powerful forelimb digging mechanism.

Most of these features are widely distributed along the turtle stem and into the crown clade, indicating the common ancestor of Eunotosaurus and modern turtles possessed a body plan significantly influenced by digging, the researchers concluded.​

​Toronto, July 15 (IANS) After analysing Kepler space telescope data, astronomers from the University of Toronto, Canada, have found a clear understanding yet of a class of exoplanets called 'Warm Jupiters', showing that many have unexpected planetary companions.

The analysis provides strong evidence of the existence of two distinct types of 'Warm Jupiters', each with their own formation and dynamical history.

The two types include those that have companions and thus, likely formed where we find them today and those with no companions that likely migrated to their current positions.

“Our findings suggest that a big fraction of 'Warm Jupiters' cannot have migrated to their current positions dynamically and that it would be a good idea to consider more seriously that they formed where we find them,” said Chelsea Huang, a Dunlap Fellow at the Dunlap Institute for Astronomy and Astrophysics, University of Toronto.

Warm Jupiters are large, gas-giant exoplanets -- planets found around stars other than the Sun.

They are comparable in size to the gas-giants in our solar system.

But unlike the Sun's family of giant planets, “Warm Jupiters” orbit their parent stars at roughly the same distance that Mercury, Venus and the Earth circle the Sun.

They take 10 to 200 days to complete a single orbit.

Because of their proximity to their parent stars, they are warmer than our system's cold gas giants -- though not as hot as “Hot Jupiters” which are typically closer to their parent stars than Mercury.

Instead of finding "lonely", companion-less “Warm Jupiters”, the team found that 11 of the 27 targets they studied have companions ranging in size from Earth-like to Neptune-like.

“The number of 'Warm Jupiters' with smaller neighbours may be even higher. We may find that more than half have companions,” Huang noted in a paper published in the Astrophysical Journal.​

London, July 15 (IANS) Levels of global biodiversity loss are no longer within the safe limit and this may negatively impact the ecosystem function and the sustainability of human societies, a new study has revealed.

According to the study, levels of biodiversity loss are so high that if left unchecked, they could undermine efforts towards long-term sustainable development.

"We know biodiversity loss affects ecosystem function but how it does this is not entirely clear. What we do know is that in many parts of the world, we are approaching a situation where human intervention might be needed to sustain ecosystem function," said Tim Newbold of the University College of London.

The researchers found that grasslands, savannas and shrublands were most affected by biodiversity loss, followed closely by many of the world's forests and woodlands. 

The ability of biodiversity in these areas to support key ecosystem functions such as growth of living organisms and nutrient cycling has become increasingly uncertain, suggested the study published in the journal Science.

For 58.1 per cent of the world's land surface which is home to 71.4 per cent of the global population, the level of biodiversity loss is substantial enough to question the ability of ecosystems to support human societies, revealed the study.

"It's worrying that land use has already pushed biodiversity below the level proposed as a safe limit," said Andy Purvis, Professor at the Imperial College, London.

The team used data from hundreds of scientists to analyse 2.38 million records for 39,123 species at 18,659 sites which were then applied to estimate how biodiversity in every square kilometre land has changed since before humans modified the habitat.

They found that biodiversity hotspots are facing threat, showing a decline. Other high biodiversity areas, such as Amazonia, which have seen no land use change have higher levels of biodiversity and more scope for proactive conservation.​

​New York, July 15 (IANS) By creating a virtual tissue model of diabetes in the eye, researchers have shown precisely how a small protein that can both damage or grow blood vessels in the eye causes vision loss and blindness in people with diabetes.

The study, reported in the journal PLOS Computational Biology, could also lead to better treatment for diabetic retinopathy, which currently requires multiple, invasive procedures that are not always effective in the long term.

A common cause of vision loss in people with diabetes, diabetic retinopathy is responsible for one percent of all blindness worldwide.

"With the current epidemic of diabetes in adults, the number of people with vision damage from diabetes will continue to rise," said lead author on the study Thomas Gast from Indiana University School of Optometry in the US.

"This paper establishes a step-by-step pathway from a diabetic's elevated blood sugars to the vascular complications in the eye. Therapeutically, understanding a disease can lead to improved treatments," Gast noted.

A major way diabetic retinopathy threatens vision is diabetic edema. In this condition, the smallest vessels supplying the retina with oxygen become leaky, causing fluid to swell the central retinal area and impairing the type of vision required for precise activities such as reading.

This happens because the loss of blood flow in a vessel causes the local oxygen level to drop, which stimulates local production of vascular endothelial growth factor, or VEGF, a protein which in most tissues causes the growth of new blood vessels to repair damage. 

However, in a retina with elevated sugar levels, instead of repairing the damage, physicians observe a cascade of damage that propagates from the initial blocked vessel. 

The rate and area of the damage's progression also vary greatly between patients in a seemingly unpredictable way.

The virtual retina model in the study provided strong evidence for why this pattern of disease progression was so variable, and predicted where damage would occur next. 

It showed that the blockage of one vessel causes a local loss of oxygen in the retina, which triggers release of VEGF that spreads over a larger region, which, in turn increases the probability of blockage in the surrounding vessels, creating a "domino effect".​

​New York, July 16 (IANS) A malfunctioning immune system may be responsible for social deficits in neurological diseases such as autism-spectrum disorders and schizophrenia, suggests new research.

"Our findings contribute to a deeper understanding of social dysfunction in neurological disorders, such as autism and schizophrenia, and may open new avenues for therapeutic approaches," said Vladimir Litvak, Assistant Professor at the University of Massachusetts Medical School in the US.

The study was published in the journal Nature.

The researchers developed and employed a novel systems-biology approach to investigate the complex dialogue between immune signalling and brain function in health and disease.

Using this approach, the scientists found that immune system signalling can directly affect, and even change, social behaviour in mice and other model animals.

The researchers predicated an unexpected role for interferon gamma (IFN-?), an important substance secreted by immune cells, in promoting social brain functions.

In the course of the research, they found that blocking IFN-? in mice made mouse brains become hyperactive and caused atypical social behaviour. 

Restoring of IFN-?-signalling in the brain normalised brain activity and social behaviour. 

"The brain and the adaptive immune system were thought to be isolated from each other, and any immune activity in the brain was perceived as a sign of pathology,” said Jonathan Kipnis from the University of Virginia.

"And now, not only are we showing that they are closely interacting, but some of our behaviour traits might have evolved because of our immune response to pathogens," Kipnis explained.​

​New York, July 17 (IANS) Researchers have created a comprehensive molecular atlas of brain development in non-human primate that could shed crucial light on what makes human brain development distinct.

This analysis uncovered features of the genetic code underlying brain development in our close evolutionary relative, while revealing distinct features of human brain development by comparison.

"This is the most complete spatiotemporal map we have for any mammal's development, and we have it in a model system that provides directly meaningful insight into human brain development, structure, and function," said Ed Lein, investigator at Allen Institute for Brain Science, a US-based non-profit medical research organisation.

"This exceptional dataset is useful for exploring precisely where and when genes are active in relation to the events of brain development and the onset of brain disorders," Lein noted in an analysis of the atlas published in the journal Nature.

The study is based on the US National Institutes of Health (NIH) Blueprint Non-Human Primate (NHP) Atlas, a publicly available resource created by the Allen Institute and colleagues at the University of California, Davis and the California National Primate Research Centre.

The goal of the NHP atlas was to marry the techniques of modern transcriptomics with the rich history of anatomical developmental studies by measuring gene activity at a series of ten important stages in prenatal and postnatal brain development.

At each stage, a technique called laser microdissection was used to precisely isolate fine layers and nuclei of cortical and subcortical brain regions associated with human psychiatric disease, thereby creating a high resolution time series of the generation and maturation of these brain regions and their underlying cell types.

The authors collaborated with colleagues at the Baylor College of Medicine to use this molecular map to pinpoint when and where candidate genes for diseases like autism and schizophrenia become active.

"This tremendous resource is freely available to the research community and will guide important research into the etiology of many developmental disorders for years to come," Michelle Freund, programme officer at National Institute of Mental Health, noted.​