Knowledge Update

Washington, Oct 26 (IANS) Astronauts aboard the International Space Station have started planting their third on-orbit crop of red romaine lettuce, NASA said.

"Early this morning, NASA astronaut Shane Kimbrough initiated the Veg-03 experiment, one of his first science assignments as a new crew member aboard the orbiting laboratory," the US space agency said in a statement on Wednesday.

Astronomers are using a plant growth system called "Veggie" for their experiment.

The Veg-03 crop will be the Veggie team's first on-orbit attempt at a new, repetitive harvest technique termed ‘Cut-and-Come-Again'.

"Once the plants are approximately four weeks old, a selection of leaves can be harvested for a bit of fresh lettuce and possibly science samples. Meanwhile, some leaves are left intact along with the core of the plant, and will continue to grow and produce more leaves," explained said Nicole Dufour, NASA's Veggie project manager. 

"We expect this will increase the on-orbit crop yield, as well as allow for more opportunities to supplement our astronauts' diets with fresh, nutritious food from the same plants, which is an important goal of the ‘pick-and-eat' food concept," Dufour noted.

The team is anxiously awaiting germination results, expected early next week, Dufour said.

Astronauts on future long-duration space missions will need to be able to grow their own food to supplement their diets. 

Using the Veggie plant growth facility aboard the station, Veg-03 builds on the successes of previous studies, including Veg-01, which resulted in the first-ever on-orbit harvest and sampling of fresh produce during the summer of 2015. 

Techniques learned from Veggie crops will help NASA prepare for the Journey to Mars.

​Washington, Oct 26 (IANS) In good news for stroke and spinal cord injury patients, researchers have designed a lower-limb robot exoskeleton -- a wearable robot that features natural knee movement to help patients regain the ability to walk or help strengthen their muscles.

Researchers from Beihang University in China and Aalborg University in Denmark developed the wearable robot to greatly improve patients' comfort and willingness to wear it for gait rehabilitation.

The team's approach focused on the knee joint, one of the most complex mechanical systems within the human body and a critical player during gait.

The knee joint's motion is actuated by several skeletal muscles along its articular surfaces, and its center of rotation moves.

"Our new design features a parallel knee joint to improve the bio-imitability and adaptability of the exoskeleton," explained Weihai Chen, professor at Beihang University.

Movement transparency is critical when wearing a robot for gait rehab.

When wearing the exoskeleton, its movement should be synchronised and consistent with a patient's natural movement.

For this, the team focused on bionic mechanical design.

"To improve the transparency of the robot, we studied the structure of the human body, then built our model based on a biometric design of the lower limb exoskeleton," Chen said.

This design is the first known use of a parallel mechanism at the knee joint to imitate skeletal muscles.

As far as its applications, the exoskeleton's main role will be to help stroke or spinal cord injury patients with their rehab.

"We plan to streamline it to be wearable and to provide a comfortable training experience," Chen noted in the journal Review of Scientific Instruments.

The team is also developing virtual reality games to help make the training process more enjoyable.

The next step for the team is to collaborate with hospitals, because testing the robot out with patients can provide critical feedback from patients and doctors.

London, Oct 25 (IANS) A protein found in the blood of pregnant women could be used to develop tests to determine the health of their babies and aid decisions on early elective deliveries, a study reveals.

Low levels of the blood marker known as DLK1 can predict poor foetal growth and complications in pregnancy, and could be used as a non-invasive prenatal diagnostic, the study suggested.

"Measuring DLK1 levels in the mother's blood could be a reliable and non-invasive way of predicting whether there are likely to be complications, especially those that cause reduced nutrient supply to the baby," said Marika Charalambous, researcher at the Queen Mary University of London.

DLK1 is a protein that is found in high levels in the mother's blood during pregnancy, in humans and rodents. But little has been known about its source, what it does, and whether it can indicate anything about the health of a foetus.

The study published in the journal Nature Genetics initially used mice experiments that involved knocking out the gene in either the foetus or the mother, and then measuring the mother's DLK1 level to determine its source.

The researchers found that the protein originates from the embryo which means that its levels in maternal blood could provide a direct readout of the embryo's biological state.

The researchers studied 129 first-time mothers, taking measurements of DLK1 levels in their blood and recording the outcomes of their pregnancies. 

They found that low DLK1 levels were associated with reduced growth of the foetus resulting from pregnancy complications, including poor blood flow through the umbilical cord.

The team then looked at how DLK1 affects the metabolism of a pregnant mouse. When fasting for 24 hours, humans start a process known as 'ketosis', which is what the Atkins diet is based on, and involves burning the energy from fat stores to keep the body functioning.

When DLK1 was inactivated in pregnant mice, their fasting response was impaired by not being able to begin ketosis. This indicated the importance of DLK1 in providing energy for the foetus and their growth, and DLK1 levels in the mother were found to be a good predictor of the mass of their offspring.

​Sydney, Oct 25 (IANS) Increased muscle strength may help to improve brain function in adults who suffer from mild cognitive impairment (MCI), shows a new study.

MCI defines people who have reduced cognitive abilities such as reduced memory, but are still able to live independently. It is a precursor to Alzheimer's disease.

The findings published in the Journal of American Geriatrics show a positive causal link between muscle adaptations to progressive resistance training and the functioning of the brain among those over the age of 55 with MCI.

"What we found in this follow-up study is that the improvement in cognition function was related to their muscle strength gains. The stronger people became, the greater the benefit for their brain," said Yorgi Mavros, researcher at the University of Sydney, Australia.

The study participants were aged between 55 and 86 and were divided into four groups doing either: resistance exercise and computerised cognitive training; resistance exercise and a placebo computerised training (watching nature videos); brain training and a placebo exercise programme (seated stretching/calisthenics); or placebo physical exercise and placebo cognitive training.

Participants doing resistance exercise prescribed weight lifting sessions twice week for six months, working to at least 80 per cent of their peak strength. As they got stronger, the amount of weight they lifted on each machine was increased to maintain the intensity at 80 per cent of their peak strength.

The cognitive training and placebo activities did not have this benefit. The benefits persisted even 12 months after the supervised exercise sessions ended.

"The more we can get people doing resistance training like weight lifting, the more likely we are to have a healthier ageing population," Mavros added.

The study suggested that exercising frequently, at least twice a week and at a high intensity will give the maximum benefit for brain.

​San Francisco, Oct 25 (IANS) Online Payment gateway PayPal has joined social media giant Facebook where the service will now be available in Messenger for people in the US to shop via chatbots.

London, Oct 25 (IANS) Do not be surprised if tomorrow your children are taught by robots in their primary school classrooms as Spanish researchers are close to developing robotic tutors that can detect the emotional state of children while interacting with educational software which will ultimately improve their learning experience.

​London, Oct 25 (IANS) Telling self-serving lies may gradually lead people to a bigger one and finally push them down a slippery slope where their brains may start to adapt to the dishonesty, making deceit look much easier, an interesting study has revealed.

The findings showed that telling small lies desensitises our brains to the associated negative emotions and may encourage us to tell bigger lies in future.

Further, amygdala -- a part of the brain associated with emotion -- was found to be most active when people first lied for their personal gain. 

The amygdala's response to lying declined with every lie while the magnitude of the lies escalated. 

Larger drops in amygdala activity predicted bigger lies in future, the researchers said.

"When we lie for personal gain, our amygdala produces a negative feeling that limits the extent to which we are prepared to lie," said Tali Sharot from University College London (UCL).

"However, this response fades as we continue to lie, and the more it falls the bigger our lies become. This may lead to a 'slippery slope' where small acts of dishonesty escalate into more significant lies," Sharot observed.

For the study, the team included 80 volunteers who took part in a team estimation task that involved guessing the number of pennies in a jar and sending their estimates to unseen partners using a computer. 

Participants were told that aiming for the most accurate estimate would benefit them and their partner and over-estimating the amount would benefit the volunteer at their partner's expense. 

The results revealed that people started by slightly exaggerating their estimates which elicited strong amygdala responses. 

Their exaggerations escalated as the experiment went on while their amygdala responses declined.

The researchers only tested dishonesty in this experiment, but the same principle may also apply to escalations in other actions such as risk taking or violent behaviour, they stated, in the study published in the journal Nature Neuroscience.

​London, Oct 25 (IANS) Along with our skin that loses the firmness and elasticity of the youth, our brain too starts to sag as we age, researchers say.

A recent study found that as humans age, their brain folds and the tension on the cerebral cortex -- the outer layer of neural tissue in our brains -- appears to decrease. 

Previous research has shown that this folding of the cortex across mammalian species follows a universal law -- that is, regardless of size and shape, they all fold in the same way.

"Our study has shown that we can use this same law to study changes in the human brain," said lead author Yujiang Wang from the Newcastle University in Britain.

However, this effect was more pronounced in individuals with Alzheimer's disease, the researchers said.

"In Alzheimer's disease, this effect is observed at an earlier age and is more pronounced. The next step will be to see if there is a way to use the changes in folding as an early indicator of disease," Wang added. 

The study also found that male and female brains differ in size, surface area, and the degree of folding. 

Indeed, female brains tend to be slightly less folded than male brains of the same age. Despite this, male and female brains are shown to follow exactly the same law, the researchers said.

The study sheds light on the underlying mechanisms which affect brain folding and could be used in the future to help diagnose brain diseases, the researchers observed.

"More work is needed in this area but it does suggest that the effect Alzheimer's disease has on the folding of the brain is akin to premature ageing of the cortex," Wang noted in the paper that appeared in the journal PNAS.

London, Oct 25 (IANS) Human-made noise can have a detrimental impact on an animal's use of information from scent, thereby putting them at greater risk of being attacked by predators, new research has found.

One obvious way in which human-made noise can cause animals problems is through the masking of valuable acoustic information.

"What our study shows for the first time is that there could also be disruption to the use of olfactory information; human-made noise could affect decision-making based on information gathered using a different sense," said lead author of the study Amy Morris-Drake from the University of Bristol in England.

Using field-based experimental trials on dwarf mongooses in South Africa, the researchers combined sound recordings and fecal samples to demonstrate that road-noise playback negatively affected the mongooses' ability to detect predator feces. 

Even after detection, the additional noise led to less information gathering and less vigilance, making the mongooses more vulnerable to danger, according to the study published in the journal Current Biology.

"We've known for a long time that noise from urbanisation, traffic and airports can detrimentally affect humans by causing stress, sleep deprivation, cardiac problems and slower learning. What's becoming increasingly clear is that a lot of other species -- mammals, birds, fish, insects and amphibians -- are also impacted in all sorts of ways by anthropogenic, or human-made, noise," Andy Radford from the University of Bristol noted.

Closely monitoring the mongooses, the team found that their adaptive responses to predatory cues, such as increased inspection of the cue, vigilance scanning for danger and more time spent near the safety of the burrow, were all disrupted by road traffic noise.

New York, Oct 25 (IANS) A drug, which is already used in high doses in medical detoxification emergencies, may help prevent many age-related health problems when used at much lower levels, suggests new research conducted on rats.

The drug N-acetyl-cysteine, or NAC might help maintain levels of a known antioxidant glutathione and prevent the routine metabolic declines associated with ageing, said the study published in the journal Redox Biology.

"Using NAC as a prophylactic, instead of an intervention, may allow glutathione levels to be maintained for detoxification in older adults," the researchers said.

The detoxification compound glutathione, helps resist the toxic stresses of everyday life -- but its levels decline with age and this sets the stage for a wide range of age-related health problems.

"We've known for some time of the importance of glutathione as a strong antioxidant," said lead author Tory Hagen, Professor at Oregon State University in the US.

"What this study pointed out was the way that cells from younger animals are far more resistant to stress than those from older animals," Hagen noted.

Decline of the detoxification mechanisms are linked to cardiovascular disease, diabetes and cancer, according to scientists.

"In young animal cells, stress doesn't cause such a rapid loss of glutathione. The cells from older animals, on the other hand, were quickly depleted of glutathione and died twice as fast when subjected to stress," Hagen said.

"But pre-treatment with NAC increased glutathione levels in the older cells and largely helped offset that level of cell death," Hagen pointed out.