Knowledge Update

​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.

New York, Nov 30 (IANS) To make the most relevant replies appear on the top of a tweet thread, Twitter has added a "reply counter" and a "conversation ranking" to its mobile app.

​Sydney, Nov 30 (IANS) Dreamworld, the popular theme park in Australia's Gold Coast in Queensland, is set to reopen on December 10, six weeks after four people died when a ride crashed.

The park was closed after two women and two men, between the ages of 32 and 42, were killed when its Thunder River Rapids ride malfunctioned on October 25.

Dreamworld CEO Craig Davidson said in a statement on Wednesday that Dreamworld and WhiteWater World would reopen following an "unprecedented multi-level safety review", Xinhua news reported.

An inspection in November resulted in 10 improvement and prohibition notices issued for the theme parks.

However, the Thunder River Rapids ride involved in the fatal accident would be demolished.

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.

New York, Nov 29 (IANS) Your genes and place of birth can have a major effect on the formation of the microbial community in the gut -- which plays an important role in keeping one healthy, a research has showed.

The study proved that gut microbiome plays a leading role in the body's immune response. Thus, controlling the microbes in the gut could influence the immune system and disease vulnerability.

The findings showed the early life environment is very important for the formation of an individual's microbiome. 

The moderate shifts in diet, as we age, also determines exactly what functions the microbes carry out in the gut.

"We are starting to tease out the importance of different variables, like diet, genetics and the environment, on microbes in the gut. It turns out that early life history and genetics both play a role," said Janet Jansson at Pacific Northwest National Laboratory (PNNL) in Washington.

For the study, the scientists analysed more than 50,000 genetic variations in mice and linked specific genes in mouse to the presence and abundance of specific microbes in its gut.

The researchers found that the microbiome retained a clear microbial signature formed where the mice were first raised -- effectively their "hometown". 

The microbial trait -- which plays an important role in fighting infections -- also gets carried over to the next generation, the researchers said.

Further, the gut was also found to have in abundance, a specific probiotic strain of lactobacillales -- a microbe linked with higher levels of important immune cells known as T-helper cells. 

"We found that the level of T-helper cells in the blood of mice is well explained by the level of lactobacillales -- found in yogurt and very often used as a probiotic, in the gut," added Antoine Snijders from Lawrence Berkeley National Laboratory (Berkeley Lab) in California, US. 

The study was published in the journal Nature Microbiology.

​London, Nov 29 (IANS) If you drink 3-5 cups of coffee a day, new research spells good news for you! A moderate intake of coffee may provide protection against age-related cognitive decline and other neurodegenerative diseases such as Alzheimer's and Parkinson's disease, says recent research.

The researchers, from the University of Coimbra (CNC) in Portugal, suggested that regular, long-term coffee drinking may reduce the risk of Alzheimer's disease by up to 27 per cent.

The greatest protection against cognitive decline can be seen at an intake of nearly 3-5 cups of coffee per day, they said.

"Moderate coffee consumption could play a significant role in reducing cognitive decline which would impact health outcomes and healthcare spending," said Professor Rodrigo A. Cunha, at the university.

Caffeine, anti-inflammatory agents as well as antioxidants such as caffeic acid -- a polyphenol (antioxidant) found in coffee -- may be associated with the improved cognitive function, the researchers said.

Intake of up to 400mg of caffeine -- the equivalent of up to 5 cups of coffee per day -- from all sources do not raise any concerns for healthy adults, suggested European Food Safety Authority (EFSA) in its scientific opinion on the safety of caffeine. 

The research was presented at ISIC's symposium held during the European Union Geriatric Medicine Society's 2016 Congress in Lisbon recently. 

​New York, Nov 29 (IANS) The rising levels of Apple calendar spamming is frustrating the Cupertino-based tech giant's iPhone or iPad customers by "reminding" them of buying stuff they never asked for, the media reported on Tuesday. Apple's calendar app allows invites to be sent by unauthenticated users and pushed directly to a handset, a report in Forbes said. "You get a bubble alert on the calendar app, text in your inbox you have to read and depending how you have set up your device you might get a 'useful' notification that you have no choice but to read and clear," the report pointed out. The problem that Apple may face with this issue is that the success of this route to potential customers will become a popular route for spammers. According to the report, being able to mark invites as spam, to be able to blacklist addresses and to have some processing done on the server side to stop a flood of invites from a single source may help the customers deal with the issue. "If this can be implemented quickly, then calendar spam would be nothing more than a short-term annoyance," the report said. Until Apple finds a permanent solution to this problem, the tech giant's loyalists could push all spam requests into a separate calendar and then deleting that calendar eventually swiping out all the entries at once. Users may also change iCloud calendar settings from desktop to invite notifications from 'in-app' to 'email' and use email client to filter the spam.