Knowledge Update

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.

​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.

New York, Oct 25 (IANS) In a first, Harvard University researchers have made an entirely 3D-printed organ-on-a-chip with integrated sensing that can offer a viable alternative to traditional animal testing.

"We are pushing the boundaries of three-dimensional printing by developing and integrating multiple functional materials within printed devices," said coauthor of the study Jennifer Lewis.

"This study is a powerful demonstration of how our platform can be used to create fully functional, instrumented chips for drug screening and disease modeling," Lewis noted.

Organs-on-chips mimic the structure and function of native tissue and have emerged as a promising alternative to traditional animal testing. 

However, the fabrication and data collection process for organs-on-chips is expensive and laborious. Currently, these devices are built in clean rooms using a complex, multi-step lithographic process and collecting data requires microscopy or high-speed cameras.

"Our approach was to address these two challenges simultaneously via digital manufacturing," Travis Busbee, coauthor of the paper and graduate student in the Lewis Lab, pointed out. 

"By developing new printable inks for multi-material 3D printing, we were able to automate the fabrication process while increasing the complexity of the devices," Busbee said.

Built by a fully automated, digital manufacturing procedure, the 3D-printed heart-on-a-chip can be quickly fabricated in customised form factors allowing researchers to easily collect reliable data for short-term and long-term studies.

The researchers believe that the new approach to manufacturing, described in the journal in Nature Materials, may one day allow researchers to rapidly design organs-on-chips, also known as microphysiological systems, that match the properties of a specific disease or even an individual patient's cells.

"This new programmable approach to building organs-on-chips not only allows us to easily change and customise the design of the system by integrating sensing but also drastically simplifies data acquisition," study first author Johan Ulrik Lind said.

​Toronto, Oct 25 (IANS) Dismissing a common perception that dinosaurs were solitary, vicious monsters, researchers have found evidence that just like most modern animals, these gigantic creatures too loved company and they lived and died together in groups.

"The common mythology of dinosaurs depicts solitary, vicious monsters running around eating everything," said one of the researchers Gregory Funston from University of Alberta in Canada. 

"Our discovery demonstrates that dinosaurs are more similar to modern animals than people appreciate," Funston noted.

"This evidence shows that dinosaurs were social beings with gregarious behaviour who lived and died together in groups," he added.

The discovery comes from a site in Mongolia, first encountered by paleontologists a decade ago. The site contained thousands of shards of destroyed bone, belying the telltale evidence of a previous discovery by fossil poachers. 

After conducting additional field work, scientists discovered a bonebed with an assemblage of bird-like Avimimus dinosaurs, who were extremely rare prior to this discovery.

Though it is common knowledge that modern birds form flocks, this is the first evidence of flocking behavior in bird-like dinosaurs, Funston explained.

"With an assemblage like this, you can't really understand why the dinosaurs died together unless you see the field site," Funston said. 

"We can tell that they were living together around the time of death, but the mystery still remains as to why," he added.

The findings on the bird-like dinosaur Avimimus from the late-Cretaceous period were published in the journal Scientific Reports.

​London, Oct 23 (IANS) There is no link between how hungry we feel and the amount of calories we consume, reveals a study.

It suggests that food marketed as having appetite-modifying properties does not alter our calorie intake. 

The findings, published in the journal Food and Science Nutrition, highlighted the health claims made by the food industry and the way in which many products are advertised -- especially those aimed at people trying to lose weight.

"The food industry is littered with products which are marketed on the basis of their appetite-modifying properties. Whilst these claims may be true, they shouldn't be extended to imply that energy intake will be reduced as a result," said Bernard Corfe, Researcher at the University of Sheffield. 

Researchers analysed 462 scientific studies and arrived at the conclusion that appetite ratings failed to correspond with energy intake -- the number of calories consumed -- in the majority of studies.

Corfe said, "For example, you could eat a meal which claims to satisfy your appetite and keep you feeling full-up for a long period of time but nonetheless go on to consume a large amount of calories later on." 

The research team suggested that more research is needed to examine other factors governing actual food intake, including sensorial environment, social factors, entrained behaviour relating to food timing, along with our innate physical regulation of intake.

​New York, Oct 22 (IANS) Household dysfunction or any adverse event in childhood may have a short-term affect on a child's health and weight in early days as well, finds a study.

The study suggested that children exposed to early adversity also have increased risk for asthma, infection, somatic complaints, and sleep disruption. 

Maternal mental health issues are associated with elevated cortisol levels, and maltreatment is associated with a lower cortisol profile.

For the study, the researchers examined 39 cohort studies to determine the effect that adverse childhood experiences have on health and biological outcomes in children.

"The majority of research on early adversity has looked at long-term adult outcomes. While this research has helped identify the problem, we must also deepen our understanding of what is happening in the brains and bodies of our children as they experience adversity," said Debby Oh, Researcher at the Center for Youth Wellness, US in a statement.

The researchers suggested that with appropriate intervention, children are able to recover from some of these negative health effects, making early detection a powerful tool to protect the health and well-being of children before long-term adult outcomes occur.