Knowledge Update

Toronto, June 12 (IANS) Ancient geologic events may have left deep 'scars' that can play a crucial role in earthquakes, mountain formation, and other ongoing geomorphological processes on our planet, says a new study.

An international team of geologists has created super-computer models that suggest former plate boundaries could stay hidden deep beneath the Earth's surface. 

These multi-million-year-old geological structures, situated at sites away from existing plate boundaries, may trigger changes in the structure and properties at the surface in the interior regions of continents.

"This is a potentially major revision to the fundamental idea of plate tectonics," said study lead author Philip Heron from University of Toronto.

Heron, together with University of Aberdeen geologist Randell Stephenson, has proposed a "perennial plate tectonic map" of the Earth to help illustrate how ancient processes may have present-day implications, according to the study published recently in the journal Nature Communications.

"It's based on the familiar global tectonic map that is taught starting in elementary school," said co-author Russell Pysklywec, who is also chair of University of Toronto's department of earth sciences. 

"What our models redefine and show on the map are dormant, hidden, ancient plate boundaries that could also be enduring or 'perennial' sites of past and active plate tectonic activity," he added.

The team used Toronto's SciNet -- Canada's most powerful computer and one of the most powerful in the world -- to make numerical models of the crust and upper-mantle into which they could introduce ancient scar-like anomalies.

Using these models, the researchers found that different parts of the mantle below the Earth's crust may control the folding, breaking, or flowing of the Earth's crust within plates -- in the form of mountain-building and seismic activity -- when under compression.

In this way, the mantle structures dominate over shallower structures in the crust that had previously been seen as the main cause of such deformation within plates.

"The mantle is like the thermal engine of the planet and the crust is an eggshell above," said Pysklywec. "We're looking at the enigmatic and largely unexplored realm in the Earth where these two regions meet," he added.

The simulations show that mantle anomalies are generated through ancient plate tectonic processes, such as the closing of ancient oceans, and can remain hidden at sites away from normal plate boundaries until reactivation generates tectonic folding, breaking, or flowing in plate interiors.​

​London, June 11 (IANS) Prolonged repetitive physical workload increases the risk of developing rheumatoid arthritis, new research has found.

The findings suggest that building workers are particularly vulnerable to developing the condition.

For example, exposure to repeated vibration , carrying or lifting weights greater than 10 kg, bending/turning, and working with hands either below knee level, or above shoulder level may put people at higher risk of developing the inflammatory disorder affecting many joints, including those in the hands and feet, the findings showed.

For the study, the researchers analysed information from a population of 3,680 rheumatoid arthritis patients and 5,935 matched controls included in the Swedish Epidemiological Investigation of Rheumatoid Arthritis (EIRA). 

To investigate whether some people are more susceptible than others, the risk was compared in participants with and without a specific genotype (HLA-DRB1), and an analysis was performed in relation to the presence/absence of ACPA (anti-citrullinated protein antibodies) among rheumatoid arthritis patients.

"We found that some types of physical workload increased the odds of developing RA (rheumatoid arthritis) more than others," said Pingling Zeng from Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden. 

"There also appeared to be a significant interaction between genetic makeup, in terms of HLA-DRB1 genes, and the risk of ACPA-positive RA from specific types of physical workload," she noted.

The estimated odds ratio of developing rheumatoid arthritis in exposed versus unexposed participants was greater than or equal to 1.5, the study said.

The findings were presented at the European League Against Rheumatism Annual Congress (EULAR 2016) in London.

"These new insights into the cause of RA may hopefully lead to effective strategies to prevent the development of RA, particularly in those RA patients with a susceptible genotype," Zeng concluded.​

New York, June 8 (IANS) Formed in the early stages of universe, carbon planets consisting of graphite, carbides and diamonds might have been the first potentially habitable worlds, suggests a new research.

"This work shows that even stars with a tiny fraction of the carbon in our solar system can host planets," said lead author and Harvard University student Natalie Mashian.

"We have good reason to believe that alien life will be carbon-based, like life on the Earth, so this also bodes well for the possibility of life in the early universe," she added.

The early universe consisted mostly of hydrogen and helium, and lacked chemical elements like carbon and oxygen necessary for life as we know it.

Only after the first stars exploded as supernovae and seeded the second generation did planet formation and life become possible.

The study, published recently in the journal Monthly Notices of the Royal Astronomical Society, examined a particular class of old stars known as carbon-enhanced metal-poor stars (CEMP).

"These stars are fossils from the young universe," said Mashian's PhD thesis advisor Avi Loeb from Harvard-Smithsonian Centre for Astrophysics. 

"By studying them, we can look at how planets, and possibly life in the universe, got started," he added.

Although lacking in iron and other heavy elements compared to Sun, CEMP stars have more carbon than expected given their age. 

According to the researchers, a dedicated search for planets around CEMP stars would help in finding out "how early planets may have formed in the infant universe". 

"We'll never know if they exist unless we look," Mashian said.​

New York, June 8 (IANS) An international team of astronomers has discovered a “hot Jupiter” exoplanet that is so massive and close to its parent star that it influences the star's rotation with its gravity, media reported.

The planet, called HATS-18b, is about 2,100 light years away, Popular Mechanics reported on Tuesday.

Hot Jupiters are giant exoplanets that orbit close to their parent stars. Also known as roaster planets, they orbit their stars in a short time and can be easily observed in transit. 

The newly discovered exoplanet orbits its star in just 0.84 days, has a radius about 1.34 times that of Jupiter, and has twice the mass of the Jovian gas giant in our solar system, the report said.

The research team was led by Kaloyan Penev of Princeton University. 

"The high planet mass, combined with its short orbital period, implies strong tidal coupling between the planetary orbit and the star," said the researchers.

"In fact, given its inferred age, [the star] HATS-18 shows evidence of significant tidal spin up," the authors said.

The new findings were presented in a paper published online on arXiv.org.

“The HATS-18 system is among the best systems (and often the best system) for testing a multitude of star--planet interactions, be they gravitational, magnetic or radiative, as well as planet formation and migration theories,” the authors noted.​

​Sydney, June 11 (IANS) Regular exercise of any type in middle age - from walking the dog to mountain climbing -- is the best lifestyle change you can make to prevent memory loss in the later years, suggest results of a 20-year study.

"The message from our study is very simple. Do more physical activity, it doesn’t matter what, just move more and more often. It helps your heart, your body and prevents obesity and diabetes and now we know it can help your brain,” said study author Cassandra Szoeke, associate professor at the University of Melbourne in Australia.

"It could even be something as simple as going for a walk, we weren’t restrictive in our study about what type,” Szoeke noted.

For the study, the researchers followed 387 Australian women from the Women’s Healthy Ageing Project for two decades. 

The women were aged 45 to 55-years-old when the study began in 1992.

The research team made notes of their lifestyle factors, including exercise and diet.

They were also asked to learn a list of 10 unrelated words and attempt to recall them half an hour later, known as an Episodic Verbal Memory test.

When measuring the amount of memory loss over 20 years, frequent physical activity, normal blood pressure and high good cholesterol were all strongly associated with better recall of the words.

In the study more weekly exercise was associated with better memory.

The findings suggest that regular exercise could protect people from dementia typically characterised by memory impairment.

"We now know that brain changes associated with dementia take 20 to 30 years to develop,” Szoeke said in a University of Melbourne media release.

"The evolution of cognitive decline is slow and steady, so we needed to study people over a long time period. We used a verbal memory test because that’s one of the first things to decline when you develop Alzheimer’s Disease,” Szoeke explained.

The best effects came from cumulative exercise, that is, how much you do and how often over the course of your life, she said.​

New York, June 12 (IANS) Scientists have identified for the first time a tiny liver protein that when disrupted can lead to cardiovascular disease as well as fatty liver disease -- a precursor to cancer.

Lipoproteins (VLDL) are crucial for healthy liver function. Normal VLDL secretion must be kept in a delicate balance as too little VLDL secretion causes fatty liver and, potentially, liver cancer. 

Lipoproteins are also known to increase cholesterol levels, a risk factor for plaque buildup in the arteries. 

In a study, published recently in the Journal of Biological Chemistry, Shadab Siddiqi from University of Central Florida found a tiny protein -- called a Small Valosin-Containing Protein Interacting Protein (SVIP) -- that regulates how much VLDL is secreted into the blood. 

"SVIP in the liver must be regulated properly to ensure optimum health," Siddiqi said.

He equates the operation of the tiny protein to a manually operated car. "To run smoothly, the driver must synchronise the gas pedal and the clutch. If the two aren't synchronised, the car doesn't move easily; it has fits and starts and ultimately stalls," he said.

The study also suggests that high levels of myristic acid in the diet -- through animal and dairy fats -- keep SVIP from properly regulating the liver's secretion of VLDL.

"These findings suggest that our diet modulates the complex molecular processes that have profound effects on our health and lifespan," Siddiqi explained. 

"The challenge will be in creating a therapy that does not impact the liver's many other functions," he added.​

London, June 12 (IANS) An analysis of microscopic aquatic creatures called planktonic foraminifera, whose fossil remains now resemble miniaturised popcorn, has provided the first statistical evidence that the number of species that can exist on the Earth depends on how the environment changes.

"While the idea of infinite species on a finite Earth is clearly fanciful, the relevance of upper limits to diversity is still a fractious debate amongst evolutionary biologists, ecologists and palaeontologists," said study lead author Thomas Ezard from the University of Southampton.

"We are the first to show statistically that this upper limit is environmentally dependent. It's intuitive that a changing environment alters how many species we see -- the spatial gradient of more species in the tropics than at the poles is pervasive evidence for its large-scale impact," Ezard added.

While previous research typically focused individually on either biological, climate change or geological explanations, this new study -- published recently in the journal Ecology Letters -- examined the co-dependence of these factors on how species interact.

Looking at the fossil history of 210 evolutionary species of macroperforate planktonic foraminifera in the Cenozoic Era from 65 million years ago to the present, the researchers found that the number of species was almost certainly controlled by competition among themselves and probably kept within a finite upper limit.

"We used mathematical models to reveal how environmental changes influence both the rate of diversification among species and how many species can co-exist at once. Our results suggest that the world is full of species, but that the precise fullness varies through time as environmental changes alter the outcome of competition among species," Ezard said. ​

​London, June 8 (IANS) An experiment by the European Space Agency (ESA) has passed a series of crucial tests with flying colours -- paving the way for gravitational wave observatory scheduled for launch in 2034.

A crucial component of the experiment is a two-kg cube made up of a high-purity gold and platinum alloy, which is currently sailing through space almost completely free of any force other than gravity. 

The project has proved in principle that a formation of such cubes flown in space will be able to function as a space-based gravitational wave observatory, which will be able to detect signals from supermassive black hole collisions and other violent events that would be impossible to see on Earth. 

Details of the experiment -- Laser Interferometer Space Antenna (LISA) Pathfinder mission -- was recently published in the journal Physical Review Letters. 

The free-falling test mass, as the gold and platinum cube is known, is nestled inside the shell-like LISA Pathfinder spacecraft, and has been orbiting a location in space called Lagrangian Point 1 (L1) since February 2016. 

At L1, the gravitational pull of the Earth and Sun are such that objects near the point execute orbits around L1 in much the same way that a satellite orbits the Earth.

The LISA Pathfinder mission is a crucial test of systems that will be incorporated in three spacecraft that will comprise the Laser Interferometer Space Antenna (LISA) gravitational wave observatory scheduled to commence in 2034. 

Each LISA spacecraft will contain two test masses like the one currently in the LISA Pathfinder spacecraft. The LISA Pathfinder mission's extraordinary success is a crucial step on the way to launching the LISA observatory.​

​New York, June 10 (IANS) Clouds or haze enveloping the atmosphere of exoplanets, including "hot Jupiters", could be preventing a substantial amount of water from being detected by space telescopes, says a study led by an Indian-origin scientist.

Astronomers have found many hot Jupiters -- whose mass are similar to that of Jupiter but are much closer to their parent star than Jupiter is to the Sun -- with water in their atmosphere, but others appear to have none.

"The motivation of our study was to see what these planets would be like if they were grouped together, and to see whether they share any atmospheric properties," said lead author Aishwarya Iyer from NASA's Jet Propulsion Laboratory-Pasadena, California.

"Clouds or haze seem to be on almost every planet we studied," Iyer said. "You have to be careful to take clouds or haze into account, or else you could underestimate the amount of water in an exoplanet's atmosphere by a factor of two," he added.

The clouds themselves are likely not made of water, as the planets taken into account can reach a scorching 1,100 degrees Celsius, meaning any water they host would take the form of water vapour.

In the study, published recently in the Astrophysical Journal, scientists looked at a set of 19 hot Jupiters previously observed by Hubble. The telescope's Wide Field Camera 3 had detected water vapor in the atmospheres of 10 of these planets, and no water on the other nine. 

But that information was spread across more than a dozen studies. The methods of analysing and interpretation varied because the studies were conducted separately. There had not been one overarching analysis of all these planets.

Iyer's team combined the datasets for all 19 hot Jupiters to create an average overall light spectrum for the group of planets. They then compared these data to models of clear, cloud-free atmospheres and those with various cloud thicknesses.

The scientists determined that, for almost every planet they studied, haze or clouds were blocking half of the atmosphere, on average.

"In some of these planets, you can see water peeking its head up above the clouds or haze, and there could still be more water below," Iyer said.

Scientists do not yet know the nature of these clouds or hazes, including what they are they made of.​

​London, June 11 (IANS) The Hubble Space Telescope has uncovered a mysterious solitary dwarf galaxy - a type that is smaller and messier than its cosmic cousins, lacking the majestic swirl of a spiral or the coherence of an elliptical.

This galaxy is known as UGC 4879. There are about 2.3 million light years between UGC 4879 and its closest neighbor, Leo A, which is about the same distance as that between the Andromeda Galaxy and the Milky Way, the European Space Agency said in a statement.

Launched in 1990, the Hubble Space Telescope (HST) is a project of international cooperation between NASA and the European Space Agency.

This galaxyÂ’s isolation means that it has not interacted with any surrounding galaxies, making it an ideal laboratory for studying star formation uncomplicated by interactions with other galaxies, the statement added.

Studies of UGC 4879 have revealed a significant amount of star formation in the first four billion years after the Big Bang, followed by a strange nine-billion-year lull in star formation that ended one billion years ago by a more recent re-ignition. 

The reason for this behaviour, however, remains mysterious, and the solitary galaxy continues to provide ample study material for astronomers looking to understand the complex mysteries of star birth throughout the universe.​