Knowledge Update

​Sydney, Dec 1 (IANS) Australia welcomed the first day of its summer on Thursday with a surge in the maximum temperatures that are expected to soar past 40 degrees Celsius, reports said.

As sun tilted towards the southern hemisphere heatwave was projected for Queensland and New South Wales states, Xinhua news reported.

Temperatures are expected to soar past 40 degrees Celsius over the next three to five days, nine degrees above the December average.

This has forced authorities to activate a safety plan usually reserved for floods and cyclones due to the high risk of heatstroke.

Australia's weather bureau said heatwaves have taken more lives in the 200 years than any other natural hazard downunder.

"For every 100,000 people exposed to a category five heatwave, you would get at least three fatalities," Risk Frontiers' lead catastrophe loss modeller Thomas Loridan said.

Australia's Bureau of Meteorology have rated the heatwave hitting southeast Queensland and northern New South Wales as "severe to extreme".

Washington, Dec 1 (IANS) NASA scientists are developing artificial intelligence for underwater drones that could be used to understand Earths marine environments as well as track signs of life below the surface of icy oceans believed to exist on Jupiter's moon Europa.

While satellites can study the ocean surface, their signals cannot penetrate the water and therefore robotic submersibles have become critical tools for ocean research. 

"Autonomous drones are important for ocean research, but today's drones don't make decisions on the fly," said Steve Chien, who leads the Artificial Intelligence Group at NASA's Jet Propulsion Laboratory, Pasadena, California. 

"In order to study unpredictable ocean phenomena, we need to develop submersibles that can navigate and make decisions on their own, and in real-time. Doing so would help us understand our own oceans -- and maybe those on other planets," Chien said in a NASA statement.

If confirmed, the oceans on moons like Europa are thought to be some of the most likely places to host life in the outer solar system.

If successful, this project could lead to submersibles that can plot their own course as they go, based on what they detect in the water around them. 

That could change how scientists collect data, while also developing the kind of autonomy needed for planetary exploration, said Andrew Thompson, Assistant Professor at California Institute of Technology (Caltech).

"Our goal is to remove the human effort from the day-to-day piloting of these robots and focus that time on analysing the data collected," Thompson said.

"We want to give these submersibles the freedom and ability to collect useful information without putting a hand in to correct them," Thompson noted.

As part of this research, a team of scientists from NASA and other institutions recently used a fleet of six coordinated drones to study Monterey Bay, California.

The fleet roved for miles seeking out changes in temperature and salinity. To plot their routes, forecasts of these ocean features were sent to the drones from shore.

The drones also sensed how the ocean actively changed around them. 

New York, Dec 1 (IANS) Using data from four different telescopes, a team of astronomers led by an Indian-origin researcher has reported that an asteroid discovered last year is the tiniest known asteroid.

At two meters (six feet) in diameter, the asteroid, named 2015 TC25, is also one of the brightest near-Earth asteroids ever discovered, the researchers said.

"If we can discover and characterise asteroids and meteoroids this small, then we can understand the population of objects from which they originate: large asteroids, which have a much smaller likelihood of impacting Earth," said Vishnu Reddy, Assistant Professor at University of Arizona's Lunar and Planetary Laboratory in the US .

"In the case of 2015 TC25, the likelihood of impacting Earth is fairly small," Reddy, an alumnus of Madurai Kamraj University in Tamil Nadu, said.

Small near-Earth asteroids such as 2015 TC25 are in the same size range as meteorites that fall on Earth. Astronomers discover them frequently, but not very much is known about them as they are difficult to characterise. 

By studying such objects in more detail, astronomers hope to better understand the parent bodies from which these meteorites originate.

Discovered by the University of Arizona's Catalina Sky Survey last October, 2015 TC25 was studied extensively by Earth-based telescopes during a close flyby that saw the micro world sailing past Earth at 128,000 kilometres, a mere third of the distance to the moon.

In a paper published in The Astronomical Journal, Reddy noted that new observations from the NASA Infrared Telescope Facility and Arecibo Planetary Radar showed that the surface of the asteroid is similar to a rare type of highly reflective meteorite called an aubrite. 

Aubrites consist of very bright minerals, mostly silicates, that formed in an oxygen-free, basaltic environment at very high temperatures. Only one out of every 1,000 meteorites that fall on Earth belong to this class.

"This is the first time we have optical, infrared and radar data on such a small asteroid, which is essentially a meteoroid," Reddy said. 

"You can think of it as a meteorite floating in space that hasn't hit the atmosphere and made it to the ground - yet," Reddy noted.

New York, Dec 1 (IANS) Lucy -- the common name accorded to the world-famous fossilised remains of an early human ancestor who lived 3.18 million years ago -- was adept at walking on her two legs as well as climbing trees, researchers have determined.

Evidence preserved in the internal skeletal structure of Lucy, a member of the ancient human species known as Australopithecus afarensis, suggests that she climbed trees, the study said.

Since Lucy's discovery in Ethiopia 42 years ago, paleontologists have debated whether she spent her life walking on the ground or combined walking with frequent tree climbing.

The new analysis, published in the journal PLOS ONE, showed that Lucy's upper limbs were heavily built, similar to tree-climbing chimpanzees, supporting the idea that she often used her arms to pull herself up, most likely onto tree branches. 

"It may seem unique from our perspective that early hominins like Lucy combined walking on the ground on two legs with a significant amount of tree climbing, but Lucy did not know she was unique," said one of the researchers John Kappelman from The University of Texas at Austin in the US.

Researchers also suggested that because her foot was better adapted for bipedal locomotion -- or upright walking -- rather than grasping, Lucy had to rely on upper-body strength when climbing, which resulted in more heavily built upper-limb bones.

"We were able to undertake this study thanks to the relative completeness of Lucy's skeleton," study's lead author Christopher Ruff, Professor at Johns Hopkins University School of Medicine, noted. 

"Our analysis required well-preserved upper and lower limb bones from the same individual, something very rare in the fossil record," Ruff said.

A recent study by Kappelman proposed that Lucy probably died after falling from a tall tree, where she may have been nesting to avoid predators. 

​London, Dec 1 (IANS) Patients whose human immunodeficiency virus (HIV) strains developed a resistance to older generation drugs are also resistant to modern drugs, a new study led by an Indian-origin scientist has found.

Resistance to a drug typically occurs when patients doesn't take their medication regularly enough, and for first-line treatments to work, patients generally need to take their medication 85-90 per cent of the time. 

The findings revealed that HIV can be resistant to many different drugs simultaneously.

In the study, the researchers found that 16 per cent of people who stopped responding to modern first-line treatments had HIV mutations associated with resistance to an older generation of drugs called thymidine analogues.

Among patients with a thymidine analogue mutation, 80 per cent were also resistant to tenofovir -- the main drug in most modern HIV treatment and prevention strategies.

"We were very surprised to see that so many people were resistant to both drugs, as we didn't think this was possible," said lead author Ravi Gupta, Professor at University College London.

Mutations for thymidine analogue resistance were previously thought to be incompatible with mutations for tenofovir resistance, but now HIV can be resistant to both at once, the researchers said, adding "this emphasises the need to check the genetic profile of patient's virus before prescribing first-line treatments, as they may have already developed resistance to other treatments that they did not mention having taken." 

Further, in order to prevent these multi-resistant strains from developing, the researchers asserted that there is a need for cheap, reliable resistance testing kits to help screen for drug resistance before giving treatment.

"However, until such kits are widely available, we could test the amount of virus in the bloodstream before and after giving treatment that could help detect treatment failure earlier and switch patients to second line drugs," Gupta said.

If a patient's virus becomes resistant to first-line drugs, the next stage is the expensive second-line treatment with greater side effects.

For the study, published in The Lancet Infectious Diseases, the team studied 712 HIV patients across the world whose HIV was not controlled by antiretrovirals.

Washington, Nov 29 (IANS) The first HIV vaccine efficacy study in seven years has begun in South Africa to test whether a modified vaccine candidate can provide effective protection against the AIDS virus, the US National Institutes of Health said.

The study -- called HVTN 702 -- aims to enroll 5,400 sexually active men and women aged 18 to 35 years, making it the largest and most advanced HIV vaccine clinical trial to take place in South Africa, Xinhua news agency reported.

"If deployed alongside our current armoury of proven HIV prevention tools, a safe and effective vaccine could be the final nail in the coffin for HIV," said Director of the National Institute of Allergy and Infectious Diseases (NIAID), Anthony Fauci in a statement.

The experimental vaccine regimen being tested in HVTN 702 is based on the one investigated in the RV144 clinical trial in Thailand that was found to be 31.2 per cent effective at preventing HIV infection over the 3.5-year follow-up after vaccination.

The new trial, to be conducted at 15 sites across South Africa, where more than 1,000 people become infected with HIV every day, aims to test whether it will provide greater and more sustained protection than the RV144 regimen.

Volunteers will been randomly assigned to receive either the investigational vaccine regimen or a placebo. All participants will receive a total of five injections over one year, and results are expected in late 2020.

"If an HIV vaccine were found to work in South Africa, it could dramatically alter the course of the pandemic," said HVTN 702 Protocol Chair and President of the South African Medical Research Council Glenda Gray. 

​Tokyo, Nov 29 (IANS) In an important step towards the search for extra-terrestrial life, astronomers in Japan have observed the transit of a potentially habitable Earth-like extra-solar planet known as K2-3d.

A transit is a phenomenon in which a planet passes in front of its parent star, blocking a small amount of light from the star, like a shadow of the planet.

While transits have previously been observed for thousands of other extra-solar planets, K2-3d is important because there is a possibility that it might harbour extra-terrestrial life, the researchers said.

The group of researchers from the National Astronomical Observatory of Japan (NAOJ) and University of Tokyo, among others, observed the transit using the MuSCAT instrument on the Okayama Astrophysical Observatory 188-cm telescope. 

K2-3d is an extra-solar planet about 150 light-years away that was discovered by the NASA K2 mission (the Kepler telescope's "second light").

About 30 potentially habitable planets that also have transiting orbits were discovered by the NASA Kepler mission, but most of these planets orbit fainter, more distant stars. 

Because it is closer to Earth and its host star is brighter, K2-3d is a more interesting candidate for detailed follow-up studies, the researchers said.

By observing its transit precisely using the next generation of telescopes, such as Thirty Meter Telescope (TMT), the scientists expect to be able to search the atmosphere of the planet for molecules related to life, such as oxygen.

The study, published in The Astronomical Journal, also succeeded in measuring the orbital period of the planet with a high precision of about 18 seconds. 

This greatly improved the forecast accuracy for future transit times. So now researchers will know exactly when to watch for the transits using the next generation of telescopes. 

K2-3d's size is 1.5 times the size of the Earth. The planet orbits its host star, which is half the size of the Sun, with a period of about 45 days. 

Compared to the Earth, the planet orbits close to its host star (about one-fifth of the Earth-Sun distance). 

But, because the temperature of the host star is lower than that of the Sun, calculations showed that this is the right distance for the planet to have a relatively warm climate like that of the Earth's.

​Sydney, Nov 29 (IANS) Australian researchers have reported the use of a new ultra-thin catalyst to split water into its two components, oxygen and hydrogen, to be converted and used as fuel, a report said on Tuesday.

The researchers at the Griffith University used the sheet-like, highly efficient catalysts that has long-term stability and help spur the process to create economically viable clean fuel.

The latest research was published in the Nature Energy journal, Xinhua news reported.

Just as sunlight generates electricity, the water-splitting process could do the same via the generation of clean chemical fuel such as hydrogen, a report quoted Professor Huijin Zhao, the director of Griffith's Centre.

Hydrogen would be a promising clean fuel over petrol in the foreseeable future, Zhao said.

"Scientifically it's already demonstrated, it's already working but to do this in a way that's economically viable, there's still a bit of work to do and we need government policy, general public support," he said.

"You also need those big companies to realise they should not dig up out of the ground anymore," he said.

"It's not just a simple technology issue."

New York, Nov 29 (IANS) A low-mass supernova -- a star exploding at the end of its life-cycle -- triggered the formation of our solar system, says a study based on new models an evidence from meteorites.

Supernova left forensic evidence in meteorites that formed at the birth of our solar system.

For the study, a research team led by University of Minnesota Professor Yong-Zhong Qian examined telltale patterns of short-lived radionuclides that stellar explosion produced and which are preserved today as isotopic anomalies in meteorites.

As the debris from the formation of the solar system, meteorites are comparable to the leftover bricks and mortar in a construction site. 

About 4.6 billion years ago, some event disturbed a cloud of gas and dust, triggering the gravitational collapse that led to the formation of the solar system. 

The collapse formed the proto-Sun with a surrounding disc where the planets were eventually born. But what was not known conclusively was what initiated the event.

Scientists had already suspected that a supernova would have enough energy to trigger the disturbance, but there was no conclusive evidence to support this theory.

The researchers realised that previous efforts in studying the formation of the solar system were focused on a high-mass supernova trigger, which would have left behind a set of nuclear fingerprints that are not present in the meteoric record.

Qian and his collaborators decided to test whether a low-mass supernova, about 12 times heavier than our sun, could explain the meteoritic record. 

They began their research by examining Beryllium-10, a short-lived nucleus that has four protons (hence the fourth element in the periodic table) and six neutrons, weighing 10 mass units. This nucleus is widely distributed in meteorites.

In fact the ubiquity of Beryllium-10 was something of a mystery in and of itself. 

Using new models of supernovae, Qian and his collaborators showed that Beryllium-10 can be produced by supernovae of both low and high masses. 

However, only a low-mass supernova triggering the formation of the solar system is consistent with the overall meteoritic record, said the study published in the journal Nature Communications.

Meteorites tell us what the solar system is made of and in particular, what short-lived nuclei the triggering supernova provided.

"This is the forensic evidence we need to help us explain how the solar system was formed," Qian said. 

"It points to a low-mass supernova as the trigger," Qian noted.