Knowledge Update

​London, April 25 (IANS) Researchers have for the first time visually depicted the movement of dinosaurs around the world during the Mesozoic Era -- from about 252 to 66 million years ago -- including a curious exodus from Europe.

The analysis -- based on "network theory" used to gather internet data -- also reaffirms previous studies that have found that dinosaurs continued to migrate to all parts of the world after Pangaea -- a supercontinent that existed during the late Paleozoic and early Mesozoic eras -- split into landmasses that are separated by oceans.

The findings revealed that although continental splitting undoubtedly reduced intercontinental migration of dinosaurs, it did not completely inhibit it.

While "network theory" is commonly used in computer science for quantifying internet data, such as friend connections on Facebook, it has only recently been applied to biology research and this is the first study to use it to on dinosaur research

The analysis also showed that all connections between Europe and other continents during the Early Cretaceous period -- 125-100 million years ago -- were out-going.

While dinosaur families were leaving Europe, no new families were migrating into Europe.

"This is a curious result that has no concrete explanation. It might be a real migratory pattern or it may be an artefact of the incomplete and sporadic nature of the dinosaur fossil record," said lead researcher Alex Dunhill at University of Leeds in Britain.

For the study, published in the Journal of Biogeography, the team used the Paleobiology database that contains every documented and accessible dinosaur fossil from around the world.

Fossil records for the same dinosaur families from different continents were then cross-mapped for different periods of time, revealing connections that show how they have migrated.​

Washington, April 25 (IANS) In one of its most ambitious projects in deep space, a team of NASA researchers are proposing to send robots at the centre of icy moons to explore the subsurface ocean for presence of life.

The two possible candidates are: the icy moons of gas giants Jupiter and Saturn which harbour sub-surface oceans perfect for hosting life.

According to a recent study, Jupiter’s moon Europa is creating a strong gravitational pull which is creating more heat on the moon's ice-sheet that is enough to support a sub-surface ocean.

But it is Saturn's icy moon Enceladus -- 500 km in diameter and 1.272 billion km away from the Earth - that serves as a leading candidate for extra-terrestrial life.

This year, one of most promising proposals that NASA Innovative Advanced Concepts Programme (NIAC) has received is from the researchers at the Jet Propulsion Laboratory (JPL) at Pasadena, California - proposing robots to explore the icy moons.

The Icy-Moon Cryovolcano Explorer (ICE) project aims to land on these moons and send a robotic explorer down the ice volcano to deploy a submersible to explore the ocean.

With a thick icy crust, Europa may be tough for a drilling robot to reach the subsurface ocean so the researchers have now turned their eyes on Enceladus.

The data from NASA's Cassini probe has strongly indicated that the cryovolcanic plumes of Enceladus probably originate in a biomolecule-friendly oceanic environment.

Enceladus, which probably has an ocean underlying its icy surface, has somehow managed to sprout multiple fissures along its south pole.

A surface-to-subsurface robotic system, the ICE will land on the surface of an icy moon, traverse to a cryovolcano, descend into its opening, perform in-situ science in the vent or crevasse and ultimately deploy underwater vehicles to explore a subsurface ocean.

ICE involves three modules: Descent Module (DM), Surface Module (SM) and autonomous underwater vehicles (AUVs_.

DM will carry AUVs and descend into a vent by using a combination of roving, climbing and hopping, like an experienced human alpinist.
SM will stay on the surface, generating power and communicating with the Earth.

DM will rely on the power and communication link provided by SM through a cable to minimise the size and weight.

Once DM reach the subsurface ocean, it will launch the AUVs to explore the exotic environment that potentially harbours life.

ICE brings three unique benefits. First, it enables in-situ science in a cryovolcano vent.

Although orbiters can perform in-situ science of plumes, relatively large dust grains are hard to reach orbital altitude. Yet it is those mineral grains that carry rich information about the habitability of the subsurface ocean.

Second, ICE enables the exploration of subsurface oceans by providing an access to it.

Third, it enables the operation of AUVs in subsurface ocean by providing three essential services: communication, localisation and power.

"A successful completion of the project will mature this exciting concept into a credible element of the growing outer planets and icy moons exploration portfolio,” the US space agency said in a statement.​

New York, April 23 (IANS) Researchers have developed a new method to map and track the function of brain circuits affected by autism spectrum disorder (ASD), especially in boys and identify the most effective treatment for an individual.

The functional biomarker physically measures the progress of patients with behavioural problems -- a tool that has been elusive in autism treatment.

"This is significant because biomarkers give us a 'why' for understanding autism in boys that we haven't had before," said one of the researchers Kevin Pelphrey, professor and director of the Autism and Neurodevelopmental Disorders Institute at the George Washington University in the US. 

The team found that the brain scan data could be an effective indicator of the function of the circuit in younger children and older patients alike.

It is particularly relevant for ASD patients who are difficult to diagnose and treat by providing a more definitive diagnosis and in developing a treatment programme when it is not clear if behavioural, drug or a combination of the treatments will be most effective.

"The behavioural symptoms of ASD are so complex and varied it is difficult to determine whether a new treatment is effective, especially within a realistic time frame," said led author Malin Bjornsdotter, assistant professor at the University of Gothenburg in Sweden.

"Brain function markers may provide the specific and objective measures required to bridge this gap," she added in the paper published in the journal JAMA Psychiatry.

In addition, the study also provides evidence that brain imaging is an important intervention tool for autism than the currently used functional MRI. 

The team analysed a series of 164 images from each of 114 individuals and discovered the brain scans of the social perception circuits only indicated ASD in boys. 

As the method only works for boys with autism, the researchers are leading a large-scale, nationwide study of girls with autism to identify equivalent techniques that will work for them.​

​New York, April 21 (IANS) Although men and women are equally influenced by tobacco, males tend to smoke more than females, finds new research that investigated gender differences in tobacco use among hunter-gathering egalitarian tribes.

“Surprisingly, even there, smoking is definitely a male thing,” said lead researcher Casey Roulette, anthropologist at Washington State University.

The study which focused on West Africa's Aka pygmy tribe found one of the largest recorded male-biased gender difference in smoking prevalence. 

The findings showed that a mere five percent of women smoked when compared to 94 percent men.

The high use by Aka men is surprising given that they generally need to work a few days on a neighbouring farm to afford one pack of cigarettes, the researchers said. 

While men spend a greater portion of their income on tobacco than women do, female tribe members tend to give away a greater portion of the tobacco they purchase.

"This suggests that men value tobacco more than women do," Roulette added in the paper published in the journal Human Nature. 

While women are not prohibited from tobacco use, the team found that the Aka females shy away from smoking because it can harm their unborn babies and children.

Many simply dislike the taste, while others abstain because it makes them unattractive to suitors. 

On the other hand, women in this hunter-gatherer society prefer men who smoke because they link tobacco use to greater risk taking and a man's subsequent ability to fend for his family. Those women who do smoke tend to be beyond their childbearing years.

"The Aka say that a woman becomes more like a man after menopause, which might also influence smoking among older women," Roulette noted.​

New York, April 22 (IANS) The way we shop and bargain for fruits and vegetables using our sensory powers, chimpanzees too use manipulative dexterity to evaluate and select figs -- a vital resource when preferred foods are scarce, say researchers.

The study demonstrates the foraging advantages of opposable fingers and careful manual prehension (the act of grasping an object with precision). 

The findings shed new light on the ecological origins of hands with fine motor control, a trait that enabled our early human ancestors to manufacture and use stone tools. 

“The supreme dexterity of the human hand is unsurpassed among mammals, a fact that is often linked to early tool use," said lead author Nathaniel J Dominy, professor of anthropology at Dartmouth College in the US.

For the study, Dominy and his colleagues observed the foraging behaviours of chimpanzees, black-and-white colobus monkeys, red colobus monkeys and red-tailed monkeys in Kibale National Park, Uganda. 

The primates depended on figs. To determine if the green figs are edible, chimpanzees ascend trees and make a series of sensory assessments.

They look at the fig's colour, smell the fig, manually palpate or touch each fig to assess the fruit's elasticity and bite the fig to determine the stiffness of the fruit. 

Colobus monkeys do not have thumbs and evaluate the ripeness of figs by using their front teeth.

The team observed the non-selection, rejection and ingestion of individual figs by chimps and collected specimens of figs.

Based on the sensory data obtained, the team estimated the predictive power that sensory information may have on chimpanzees when estimating the ripeness of figs.

The study, published in the journal Interface Focus, resembles that of humans shopping for fruits and provides new insight into how chimpanzees exhibit advanced visuomotor control during the foraging process and more broadly, on the evolution of skilled forelimb movements.​

​London, April 22 (IANS) As the world celebrated Earth Day on Friday, a team of European researchers has found substantially different climate change impacts on Earth for a global warming of 1.5 degrees Celsius and two degrees Celsius by 2100.

The two temperature limits are included in the Paris climate agreement, researchers said, adding that the additional 0.5 degrees Celsius would mean a 10 cm higher global sea-level rise by 2100, longer heat waves and would result in virtually all tropical coral reefs being at risk. 

"We found significant differences for all the impacts we considered," said Carl Schleussner, lead author of the study published in the journal Earth System Dynamics.

"We analysed the climate models used in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report focusing on the projected impacts at 1.5 degrees Celsius and two degrees Celsius warming at the regional level," Schleussner added.

The team considered 11 different indicators including extreme weather events, water availability, crop yields, coral reef degradation and sea-level rise.

With researchers from Germany, Switzerland, Austria and the Netherlands, they identified a number of hotspots around the globe where projected climate impacts at two degrees Celsius are significantly more severe than at 1.5 degrees Celsius. 

In tropical regions, the half-a-degree difference in global temperature could have detrimental consequences for crop yields, particularly in Central America and West Africa. 

On average, local tropical maize and wheat yields would reduce twice as much at 2 degree Celsius compared to a 1.5 Celsius temperature increase.

On a global scale, the researchers anticipate sea level to rise about 50cm by 2100 in a two degrees Celsius warmer world, 10 cm more than for 1.5 degrees Celsius warming. 

"Sea level rise will slow down during the 21st century only under a 1.5 degrees Celsius scenario," noted Schleussner.

"Our study shows that tropical regions -- mostly developing countries that are already highly vulnerable to climate change -- face the biggest rise in impacts between 1.5 degrees Celsius and two degrees Celsius," added William Hare, senior scientist at Climate Analytics, a non-profit climate science and policy institute.​

​Toronto, April 22 (IANS) After an asteroid impact that killed carnivorous bird-like dinosaurs some 65 million years ago, birds with toothless beaks survived on seeds in the absence of other food sources, say Canadian researchers.

When the dinosaurs became extinct, plenty of small bird-like dinosaurs disappeared along with giants like Tyrannosaurus and Triceratops.

Why only some of them survived to become modern day birds remained a mystery, researchers noted.

"The small bird-like dinosaurs in the Cretaceous -- the maniraptoran dinosaurs -- are not a well understood group. They are some of the closest relatives to modern birds and at the end of the Cretaceous, many went extinct, including the toothed birds but modern crown-group birds managed to survive the extinction," said first author of the study Derek Larson.

The team of researchers investigated whether the extinction at the end of the Cretaceous was an abrupt event or a progressive decline simply capped by the meteor impact. 

Larson and his colleagues looked for patterns of diversity in the teeth, which spanned 18 million years (up until the end of the Cretaceous). 

"The maniraptoran dinosaurs maintained a very steady level of variation through the last 18 million years of the Cretaceous. They abruptly became extinct just at the boundary," Larson said in a paper that appeared in the journal Current Biology.

The team suspected that diet might have played a part in the survival of the lineage that produced today's birds and they used dietary information and previously published group relationships from modern day birds to infer what their ancestors might have eaten. 

Larson and his colleagues hypothesised that the last common ancestor of today's birds was a toothless seed eater with a beak.

"There were bird-like dinosaurs with teeth up until the end of the Cretaceous, where they all died off very abruptly," said Larson, adding, "Some groups of beaked birds may have been able to survive the extinction event because they were able to eat seeds."​

​New York, April 22 (IANS) Although a combination of antiretroviral therapies has led to a decrease in the mortality rates in people with HIV infection, a new study has found that these patients often show signs of premature ageing.

Researchers discovered that the HIV-virus infection prematurely advances the human biological ageing process on an average by five years.

This further propels the onset of age-related diseases like cardiovascular disease, neurocognitive impairment, and liver problems, thus increasing the risk of mortality by 19 percent.

"The medical issues in treating people with HIV have changed. Now we worry about diseases related to ageing, like cardiovascular disease, neurocognitive impairment, and liver problems," said Howard Fox, professor at University of Nebraska in the US.

Researchers used methylation -- the process by which small chemical groups are attached to DNA -- as a tool to analyse the epigenetic changes in people's cells - that affect the DNA but not the sequence.

Methylation of DNA can impact how genes get translated into proteins.

There was no difference found between the methylation patterns in those people who were recently infected, that is less than five years and those with chronic infection of more than 12 years, the researchers added in the paper published in the journal Molecular Cell.

"We set out to look at the effects of HIV infection on methylation and I was surprised that we found such a strong ageing effect," said another researcher Trey Ideker, professor at University of California-San Diego.

The study included 137 patients in the analysis. Subjects who were chosen didn't have other health conditions that could skew the results. 

"People infected with HIV should be aware that they're of greater risk for age-related diseases and should work to diminish those risks by making healthy lifestyle choices regarding exercise, diet, and drug, alcohol and tobacco use," the researchers suggested.​

London, April 22 (IANS) Gender stereotyping in baby boys and girls may start as young as three months and men recognise gender of the new-born babies based on the pitch of their cries, researchers reveal.

Adults often wrongly assume babies with higher-pitched cries as females and lower-pitched cries are males.

The findings revealed that inspite of no actual difference in pitch between the voices of girls and boys before puberty, the study found that adults make assumptions about the gender of babies based on their cries.

"It is intriguing that gender stereotyping can start as young as three months, with adults attributing degrees of femininity and masculinity to babies solely based on the pitch of their cries,” said David Reby from the University of Sussex in Britain. 

The team recorded the spontaneous cries of 15 boys and 13 girls who were on average four months old and the participating adults were a mixture of parents and non-parents.

They synthetically altered the pitch of the cries while leaving all other features of the cries unchanged to ensure they could isolate the impact of the pitch alone. 

When told the gender of the baby, adults make assumptions about the degree of masculinity or femininity of the baby based on the pitch of the cry.

The results also indicate that men assume that boy babies are in more discomfort than girl babies with the same pitched cry which may indicate that this sort of gender stereotyping is more ingrained in men.

"The research shows that we tend to wrongly attribute what we know about adults -- that men have lower pitched voices than women -- to babies, when, in fact, the pitch of children's voices does not differ between sexes until puberty,” added Nicolas Mathevon from Hunter College in the US in the paper published in the journal BMC Psychology.​

New York, April 20 (IANS) What if you can watch the Earth -- its blue-and-white marbling stark against a black interstellar backdrop -- from space? The experience will sure evoke an intense awe like it happens with astronauts on the International Space Station (ISS).

Researchers from the University of Pennsylvania's positive psychology centre are now studying the phenomenon called the "overview effect" to better understand the emotions astronauts commonly recount when they look at the Blue Marble from space.

“We watch sunsets whenever we travel to beautiful places to get a little taste of this kind of experience. These astronauts are having something more extreme,” said lead researcher David Yaden. 

“By studying the more-extreme version of a general phenomenon, you can often learn more about it,” he added.

To understand the “overview effect”, Yaden and colleagues analysed excerpts from astronauts from all over the world who documented viewing the Earth from space. 

Themes emerged from the quotes, ideas like unity, vastness, connectedness and perception -- in general the sense of an overwhelming, life-changing moment.

The effort is to look at implications for space flight as the aeronautical community heads toward years-long missions to places like Mars and to understand how to induce a similar sensation for non-astronauts.

“We think of people who do a lot of meditation or climb mountains, people who are awe junkies, having these experiences. We don't [often] think of these very strict scientists reporting these blissful moments,” said Yaden in a paper appeared in the journal Psychology of Consciousness. 

They are now planning a follow-up experiment using virtual reality that gives participants the chance to Earth-gaze which could result in an experience similar to the "overview effect".

“In the end, what we care about is how to induce these experiences. They help people in some ways be more adaptive, feel more connected and reframe troubles,” the authors noted.​