Knowledge Update

​London, Oct 30 (IANS) Oceans may be responsible for making the Earth move in and out of ice ages every 100,000 years, finds a study.

According to the study published in the journal Geology, oceans sucking carbon dioxide (CO2) out of the atmosphere may have triggered this phenomena. 

Dubbed the "100,000-year problem", this phenomena has been occurring for the past million years or so and leads to vast ice sheets covering North America, Europe and Asia.

By studying the chemical make-up of tiny fossils on the ocean floor, the team discovered that there was more CO2 stored in the deep ocean during the ice age periods at regular intervals every 100,000 years.

This suggested that extra carbon dioxide was being pulled from the atmosphere and into the oceans at this time, subsequently lowering the temperature on the Earth and enabling vast ice sheets to engulf the Northern Hemisphere.

"We can think of the oceans as inhaling and exhaling carbon dioxide, so when the ice sheets are larger, the oceans have inhaled carbon dioxide from the atmosphere, making the planet colder. When the ice sheets are small, the oceans have exhaled carbon dioxide, so there is more in the atmosphere which makes the planet warmer," said Carrie Lear, researcher at the Cardiff University, Britain. 

"By looking at the fossils of tiny creatures on the ocean floor, we showed that when ice sheets were advancing and retreating every 100,000 years, the oceans were inhaling more carbon dioxide in the cold periods, suggesting that there was less left in the atmosphere," Lear added.

Marine algae play a key role in removing CO2 from the atmosphere as it is an essential ingredient of photosynthesis.

CO2 is put back into the atmosphere when deep ocean water rises to the surface through a process called upwelling. But when a vast quantity of sea ice is present, this prevents the CO2 from being exhaled, which could make the ice sheets bigger and prolong the ice age.

The last ice age ended about 11,500 years ago, and began 21,000 years ago, according to earlier study reports.

​London, Oct 28 (IANS) Researchers have confirmed an unassuming brown pebble, found more than a decade ago by a fossil hunter in Sussex, as the first example of fossilised brain tissue from a dinosaur.

The tissues resemble those seen in modern crocodiles and birds, said the study reported in a Special Publication of the Geological Society of London.

The fossilised brain, found by fossil hunter Jamie Hiscocks near Bexhill in Sussex in 2004, is most likely from a species similar to Iguanodon - a large herbivorous dinosaur that lived during the Early Cretaceous Period, about 133 million years ago, according to the study.

"The chances of preserving brain tissue are incredibly small, so the discovery of this specimen is astonishing," said study co-author Alex Liu from the University of Cambridge.

According to the researchers, the reason this particular piece of brain tissue has been so well preserved is that the dinosaur's brain was essentially 'pickled' in a highly acidic and low-oxygen body of water -- similar to a bog or swamp -- shortly after its death. 

"What we think happened is that this particular dinosaur died in or near a body of water, and its head ended up partially buried in the sediment at the bottom," David Norman from the University of Cambridge, noted.

"Since the water had little oxygen and was very acidic, the soft tissues of the brain were likely preserved and cast before the rest of its body was buried in the sediment," Norman noted.

Working with colleagues from the University of Western Australia, the researchers used scanning electron microscope (SEM) techniques in order to identify the tough membranes, or meninges, that surrounded the brain itself, as well as strands of collagen and blood vessels.

The structure of the fossilised brain, and in particular that of the meninges, shows similarities with the brains of modern-day descendants of dinosaurs, namely birds and crocodiles, the study said.

​London, Oct 28 (IANS) Patients could soon be diagnosed with early-stage arthritis several years before the onset of physical and irreversible symptoms, thanks to a new test developed by researchers at the University of Warwick in Britain.

The test can provide an early diagnosis of osteoarthritis (OA) and also distinguish this from early-stage rheumatoid arthritis (RA) and other self-resolving inflammatory joint disease.

"For the first time we measured small fragments from damaged proteins that leak from the joint into blood," said lead researcher Naila Rabbani of Warwick Medical School.

The test, which could be available to patients within two years, identifies the chemical signatures found in the plasma of blood joint proteins damaged by oxidation, nitration and glycation; the modification of proteins with oxygen, nitrogen and sugar molecules.

"The combination of changes in oxidised, nitrated and sugar-modified amino acids in blood enabled early stage detection and classification of arthritis - osteoarthritis, rheumatoid arthritis or other self-resolving inflammatory joint disease," Rabbani noted.

By diagnosing which type of arthritis a patient will develop at an early-stage will allow for appropriate treatment that will provide the best chance for effective treatment and potential prevention, the researchers said.

Patients with early-stage and advanced OA, RA or other inflammatory joint disease were recruited for the study alongside a control group of those with good skeletal health.

The researchers analysed plasma and synovial fluid samples from both groups.

Through their analysis, published in the journal Arthritis Research and Therapy, the researchers detected damaged proteins in characteristic patterns in the samples of those patients with early and advanced OA and RA.

These damages proteins were found at markedly lower levels in the samples of those in the control group -- providing the researchers with the identifiable biomarkers necessary for early detection and diagnosis.

​New York, Oct 28 (IANS) Teachers underrating girls' ability to solve problems in Mathematics will likely contribute to the widening of gender gap in the subject, finds a study.

According to the study, published in the journal AERA Open, beginning in early elementary school boys outperform girls in math -- especially among the highest math achievers. 

This leads to teachers giving lower ratings to girls' math skills while both the genders have similar achievement and behaviour towards the subject. 

"Despite changes in the educational landscape, our findings suggest that the gender gaps observed among children who entered kindergarten in 2010 are strikingly similar to what we saw in children who entered kindergarten in 1998," said Joseph Robinson Cimpian, Associate Professor at the New York University.

Data showed that boys and girls began kindergarten with similar math proficiency, but disparities developed by Grade 3 with girls lagging behind. The gap was particularly large among the highest math achievers.

Research also revealed disparities in teacher perceptions of students, with teachers rating the math skill of girls lower than those of similarly behaving and performing boys.

Finally, the researchers examined gendered patterns of learning behaviours to try and explain why boys are more likely to score as high math achievers. 

They found that girls' more studious approaches to learning pay off by boosting them at the bottom of the achievement distribution, but do not help the persistent gap at the top as much.

The researchers explored the early development of gender gaps in math, including when disparities first appear, where in the distribution such gaps develop, and whether the gaps have changed over the years. 

In addition to math achievement, they examined two potential contributors to gender gaps: students' learning behaviours and teacher expectations.

Overall, the researchers found remarkable consistency across both cohorts. They observed that the gender gap at the top of the distribution (among the highest achievers in math) develops before students enter kindergarten, worsens through elementary school, and has not improved over the last decade.

London, Oct 28 (IANS) Researchers have created a three-dimensional mammary gland model that could pave the way for a better understanding of the mechanisms of breast cancer.

"Much of how breast tissues respond to external stimuli such as hormones is, as yet, unknown. In order to fully tackle the mechanisms that lie behind breast cancer we first need to understand how healthy breast tissue develops," said one of the researchers Trevor Dale, Professor at Cardiff University School of Biosciences in Britain. 

"This model allows us to really study the basic biology of how the breast develops - how hormones work, what are the genetic influences," Thierry Jarde from Biomedicine Discovery Institute, Monash University in Melbourne, Australia, added.

The researchers succeeded in creating a three-dimensional mammary gland model that will pave the way for a better understanding of the mechanisms of breast cancer.

Using a cocktail of growth factors, the scientists were able to grow mouse mammary cells into three-dimensional mammary tissue.

Known as an 'organoid', the model, reported in the journal Nature Communications, mimics the structure and function of a real mammary gland. 

This would enable researchers to increase their understanding of how breast tissue develops, and provides an active model for the study of disease and drug screening.

As well as determining how to grow these life-like mammary glands, researchers also discovered how to maintain them in culture to allow ongoing experimentation.

​London, Oct 28 (IANS) Male teenagers with a higher resting heart rate and increased level of blood pressure may be at an high risk of developing psychiatric disorders such as obsessive-compulsive disorder (OCD), schizophrenia and other anxiety disorders, a study has found.

The findings showed that men in their late teenage with a resting heart rate above 82 beats per minute had 69 per cent increased risk for OCD, 21 per cent increased risk for schizophrenia and 18 per cent increased risk for anxiety disorders compared with those whose resting heart rates were below 62 beats per minute. 

Besides resting heart rate, changes in blood pressure, regulated by the autonomic nervous system, have been observed in some patients with psychiatric disorders but the results have been inconsistent.

Lower resting heart rate and blood pressure were also associated with substance use disorders and violent behaviour, said Antti Latvala from the University of Helsinki, Finland.

For the study the team used data of more than one million men in Sweden whose resting heart rate and blood pressure were measured at military conscription (average age 18) from 1969 to 2010 to examine whether differences in cardiac autonomic function were associated with psychiatric disorders.

The results were published online by JAMA Psychiatry.

Washington, Oct 28 (IANS) It took more than a year but the last bits of science data from New Horizons' Pluto flyby -- stored on the spacecraft's digital recorders since July 2015 -- arrived safely on Earth this week, NASA said.

The final item - a segment of a Pluto-Charon observation sequence taken by the Ralph/LEISA imager - from New Horizons spacecraft travelled over 5.5 billion kilometers to reach earth, the US space agency said in statement on Thursday.

The downlink came via NASA's Deep Space Network station in Canberra, Australia. It was the last of the 50-plus total gigabits of Pluto system data transmitted to Earth by New Horizons over the past 15 months.

"We have our pot of gold," said Mission Operations Manager Alice Bowman of Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland.

"There's a great deal of work ahead for us to understand the 400-plus scientific observations that have all been sent to Earth. And that's exactly what we're going to do-after all, who knows when the next data from a spacecraft visiting Pluto will be sent?" Alan Stern, New Horizons principal investigator from Southwest Research Institute in Boulder, Colorado, added. 

Because it had only one shot at its target, New Horizons was designed to gather as much data as it could, as quickly as it could - taking about 100 times more data on close approach to Pluto and its moons than it could have sent home before flying onward. 
The spacecraft was programmed to send select, high-priority datasets home in the days just before and after close approach, and began returning the vast amount of remaining stored data in September 2015.

Bowman said the team will conduct a final data-verification review before erasing the two onboard recorders, and clearing space for new data to be taken during the New Horizons Kuiper Belt Extended Mission (KEM).

KEM will include a series of distant Kuiper Belt object observations and a close encounter with a small Kuiper Belt object, 2014 MU69, on January 1, 2019, NASA said.

Canberra, Oct 28 (IANS) Life expectancy in Australia has hit a new high, with babies born in 2015 expected to live two years longer than those born in 2005, according to a report issued on Friday.

The Australian Bureau of Statistics (ABS) report showed that life expectancy had hit 84.5 years for females and 80.4 years for males, but demographics expert Peter McDonald of the University of Melbourne said that the statistics assume no improvements in healthcare and were therefore conservative estimates.

"They are not any individual's lifetime; they are just telling you the expectation of life you would get if life expectancy didn' t change... and for the last 200 years it has been going up," he said.

ABS Director of Demography Beidar Cho said the life expectancy for Australians in 2015 was comparable for other first-world nations.

"Babies born today have the highest estimated life expectancy ever recorded in Australia," Cho said in a statement.

"Male life expectancy at birth reached 80.4 years in 2015, increasing from 80.3 in 2014. Female life expectancy also increased to 84.5 years in 2015 from 84.4 in the previous year."

"For both men and women, Australia has a higher life expectancy than similar countries such as Canada, New Zealand, the UK and the US."

Meanwhile in 2005, the life expectancy of Australians was at 83.3 years for women and 78.5 years for men.

"In 2013-2015, the male and female combined life expectancy at birth estimate for Australia was 82.4 years. This was 11.9 years higher than the world average of 70.5 years in 2010-2015," Cho added.

New York, Oct 27 (IANS) US scientists have in a breakthrough research found that realistic sensations of touch can be restored in human amputees by directly stimulating the nervous system.

In the study, neuroscientists from the University of Chicago used neuroprosthetic devices to turn the pressure "felt" by a prosthetic hand into a signal that feeds directly into the parts of the brain that deal with hand movement and touch.

"If you want to create a dexterous hand for use in an amputee or a quadriplegic patient, you need to not only be able to move it, but have sensory feedback from it," said Sliman Bensmaia, Associate Professor at the University of Chicago.

"The idea is that if we can reproduce natural-feeling sensations exactly, the amputee won't have to think about it, he can just interact with objects naturally and automatically," Bensmaia added.

The team worked with two male subjects who each lost an arm after traumatic injuries. 

Both subjects were implanted with neural interfaces, devices embedded with electrodes that were attached to the median, ulnar and radial nerves of the arm. 

Those are the same nerves that would carry signals from the hand were still intact, the researchers said.

The results showed that a single feature of electrical stimulation -- dubbed the activation charge rate -- can determine the strength of the sensation -- such as intensity discrimination, magnitude scaling, and intensity matching. 

By changing the activation charge rate, the team could change sensory magnitude in a highly predictable way. 

By modulating the number of nerve fibres stimulated and the frequency of stimulation, sensory information could be transmitted such that the amputees could distinguish distinct levels of tactile intensity, that is, the difference between a seven and a 10 on a scale of intensity.

However, these artificial touch will only be as good as the devices providing input, the researchers stated. 

The study was published in the journal Science Translational Medicine.