Knowledge Update

​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.​

​New York, April 21 (IANS) In one of the largest studies on the genes involved in human behaviour, a team of over 190 researchers from 140 institutions in 17 countries has found genetic variants associated with our feelings of well-being, depression and neuroticism.

The researchers, however, advise caution when interpreting the results as genetic variants do not determine whether someone develops depressive symptoms, neuroticism or has a poor sense of wellbeing.

“In this paper, we applied advanced statistical analyses and meta-analysed or combined, results across a large number of studies which is the most powerful way to conduct this type of genetics research," said Dr Alexis Frazier-Wood, assistant professor of pediatrics and nutrition at Baylor College of Medicine and Texas Children's Hospital.

“We found three genetic variants associated with subjective well-being -- how happy a person thinks or feels about his or her life. We also found two genes harboring variants associated with depressive symptoms and 11 genes where variation was associated with neuroticism,” explained Dr Frazier-Wood.

How people think and feel about their lives depends on multiple factors, including genes.

“Genetics is only one factor that influences these psychological traits. The environment is at least as important, and it interacts with the genetic effects,” added Dr Daniel Benjamin, associate professor at University of Southern California Dornsife College of Letters, Arts and Sciences and corresponding author.

The information in this report allows researchers to look at possible ways to study these conditions.

“We can start studying the functions of these genes to begin to understand why biologically some people are more predisposed to feel this way than others," said Frazier-Wood in a paper published in the journal Nature Genetics.​

New York, April 21 (IANS) A team of US scientists has invented a new way to create three-dimensional (3D) human heart tissue from stem cells that offers cheaper and faster method to create heart tissue for testing drugs and modelling disease.

The tissue also opens the door for a precision medicine approach to treating heart disease.

"We have bioengineered micro-scale heart tissues with a method that can easily be reproduced, which will enable scientists in stem cell biology and the drug industry to study heart cells in their proper context," said Nathaniel Huebsch, postdoctoral fellow at San Francisco-based at the Gladstone Institutes.

"In turn, this will enhance our ability to discover treatments for heart disease," Huebsch added.

Creating heart cells from induced pluripotent stem cells (iPSCs) that are derived from a patient's skin cells is inadequate for drug testing because they do not properly predict how a drug will affect adult heart cells.

Additionally, heart cells created from iPSCs are challenging to make and work with, so creating large quantities can be difficult.

The micro-heart muscle addresses these concerns. Forcing the cells to organise and stretch into 3D tissue helps spur development and coaxes them into resembling more mature cells that can better predict how a drug will affect adult heart cells.

The new method, published in the journal Scientific Reports, requires a thousand-fold fewer cells to grow the tissue than other tissue engineering techniques.

Using fewer cells allows the scientists to do many more experiments with the same amount of resources.

"The beauty of this technique is that it is very easy and robust and still allows you to create three-dimensional miniature tissues that function like normal tissues," said senior author Bruce Conklin, senior investigator at Gladstone.

"We think that the micro-heart muscle will provide a superior resource for conducting research and developing therapies for heart disease," he noted.​

Toronto, April 21 (IANS) While planning a visual task, your brain initially reflects the visual goal accurately but errors accumulate during a memory delay and further escalate during the final action, say scientists from York University.

“Think of all the times you see something and plan to act on it but after only a short delay, you make a mistake," said professor Doug Crawford. 

“For example, before my morning coffee kicks in, I'm great at making silly mistakes like putting the honey away in the fridge instead of the peanut butter,” he added.

For the study, led by Amirsaman Sajad in Crawford's visuomotor neuroscience lab, researchers recorded signals in the frontal cortex area of the brain during the delay between target-related visual activity and intended gaze-related motor activity. 

The visual response and memory activity for the time in between was then analysed.

“We looked at what happens from vision to memory to action and how the spatial code changes through time in the frontal cortex,” said Sajad.

“In the Olympics tennis analogy, when a high degree of accuracy is required, a one-second delay in frontal cortex processing could make the difference between an Olympic gold and silver,” Crawford noted.

The findings, published in the journal eNeuro, are of particular significance to research in diseases affecting frontal cortex function “because if errors accumulate in healthy individuals, the accumulations would be much worse with diseases that affect frontal cortex function,” the authors noted.​

​Washington, April 21 (IANS) The International Space Station (ISS) is providing researchers a unique opportunity to study muscle loss and to investigate means for muscle preservation for people on the Earth.

"Rodent Research-3", a study sponsored by US-based pharmaceutical company Eli Lilly and Company and the Centre for the Advancement of Science in Space (CASIS), focuses on assessing the ability of a novel compound to prevent skeletal muscle wasting and weakness in mice exposed to long-duration spaceflight.

The investigation was launched aboard the eighth SpaceX resupply mission to the space station this month.

The astronauts on the space station follow rigorous exercise programmes that apply forces to their musculoskeletal systems and help them stay strong throughout their missions.

Mice exposed to spaceflight have proved to be valuable research models to understand, target and treat causes of human muscle atrophy.

"This includes modelling serious diseases that involve muscle wasting such as muscular dystrophy, amyotrophic lateral sclerosis, cancer cachexia and even ageing-related musculoskeletal frailty," said Rosamund Smith, research fellow at Eli Lilly and Company.

The ability to expose all muscles of an organism to conditions that induce muscle atrophy is not easily achieved on Earth.

"Lilly is excited to have the opportunity to conduct this investigation in space," Smith added in a NASA statement.

Loss of muscle function, rather than just a decrease in muscle size, is the critical aspect that leads to problems with physical performance in patients suffering from muscle-wasting conditions.

"The 'Rodent Research-3' study is unique not only in the experimental compound that will be tested but also because, for the first time, muscle function of the mice will be assessed during spaceflight," noted Janet Beegle, Rodent Research-3 project manager at NASA.

Although the primary research focus of "Rodent Research-3" is skeletal muscle, the investigators are studying other organ systems such as bone, both at the tissue and molecular levels.

The goal is to characterise tissue responses to spaceflight and observe how these changes vary with the length of time spent in microgravity.

"The findings will advance our understanding of the risks that long-term space exploration poses to astronauts, and can be applied towards the development of countermeasures to protect astronaut health," the researchers pointed out.

Results will be applied to ongoing discovery efforts at Eli Lilly and Company, seeking treatments for serious muscle-wasting diseases and conditions that may potentially help patients afflicted with degenerative diseases to stay strong.​

Washington, April 20 (IANS) Three solar observatories have captured the most comprehensive observations of an electromagnetic phenomenon called a "current sheet", strengthening the evidence that the understanding of solar flares is correct.

A "current sheet" is a very fast and flat flow of electrically-charged material, defined in part by its extreme thinness compared to its length and width.

"Current sheets" form when two oppositely-aligned magnetic fields come in close contact, creating very high magnetic pressure.

The multi-faceted view of the December 2013 flare was made possible by three solar-watching missions: NASA's Solar Dynamics Observatory (SDO), NASA's Solar and Terrestrial Relations Observatory (STEREO) and Hinode, a collaboration between the space agencies of Japan, the US, Britain and Europe.

Solar flares are intense bursts of light from the sun. They are created when complicated magnetic fields suddenly and explosively rearrange themselves, converting magnetic energy into light.

"The existence of a 'current sheet' is crucial in all our models of solar flares," said James McAteer, astrophysicist at New Mexico State University.

"These observations make us much more comfortable that our models are good," he added.

The strongest solar flares can impact the Earth's atmosphere and interfere with our communications systems and also disrupt onboard satellite electronics.

Unlike other space weather events, solar flares travel at the speed of light, meaning we get no warning that they are coming.

Better models lead to better forecasting, said Michael Kirk, space scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

"These complementary observations allowed unprecedented measurements of magnetic reconnection in three dimensions. This will help refine how we model and predict the evolution of solar flares," Kirk added.

Because "current sheets" are so closely associated with magnetic reconnection, observing a "current sheet" in such detail backs up the idea that magnetic reconnection is the force behind solar flares.

"You have to be watching at the right time, at the right angle, with the right instruments to see a current sheet," said McAteer in the study published in the Astrophysical Journal Letters.

The new study is unique in that several measurements of the current sheet -- such as speed, temperature, density and size -- were observed from more than one angle or derived from more than method.​

​London, April 20 (IANS) As the world gets prepared to build smart cities, new research led by an Indian-origin scientist has highlighted the dangerous effects of indoor pollution on human health and has called for policies to ensure closer monitoring of air quality.

According to Prashant Kumar from the University of Surrey, the research offers insight into "Sick Building Syndrome" and how new smart cities could help combat air quality issues.

When we think of the term "air pollution", we tend to think of car exhausts or factory fumes expelling grey smoke.

"However, there are actually various sources of pollution that have a negative effect on air quality, many of which are found inside our homes and offices. From cooking residue to paints, varnishes and fungal spores the air we breathe indoors is often more polluted than that outside," explained Kumar.

In 2012, indoor air pollution was linked to 4.3 million deaths globally, compared with 3.7 million for outdoor air pollution.

Urban dwellers typically spend 90 percent of their time indoors and this has been linked to "Sick Building Syndrome" where people exhibit a range of ill-health effects related to breathing indoor air.

"It is essential that we are able to effectively monitor indoor air pollution so that we can better understand when and where levels are worst, and in turn offer solutions to make our air healthier," added Kumar in the journal Science of the Total Environment.

"Our work looks at the use of small, low-energy monitoring sensors that would be able to gather real-time data and tell families or workers when levels of pollutants are too high," he continued.

With this research, we are calling for greater importance to be placed on ensuring buildings are built with indoor pollution monitoring in mind. As we enter the age of smart cities this is one way in which technology will actively benefit health, the authors noted.

A collaborative effort of European, Australian and British researchers led by the University of Surrey, the study assesses the harmful effects of indoor pollution in order to make recommendations on how best to monitor and negate these outcomes.

In another paper published earlier in the journal Environmental Pollution, Kumar and PhD student Anju Goel also found that outdoor air pollution was at a high where buildings were located at traffic intersections.

Even where there was low traffic volume, traffic intersections with densely built up surroundings showed twice the concentration than at open junctions.

Exposure to these concentrations showed that ground floor dwellings in these areas were exposed to twice as many harmful particles.

"This has important implications for town planning and we should consider whether we really want schools, offices or hospitals to be built within these environments," Kumar noted.​