Knowledge Update

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. 

​Toronto, Nov 28 (IANS) Children exposed to tobacco smoke in early childhood adopt anti-social behaviour, engage in proactive and reactive aggression, and face conduct problems at school, even drop out at age 12, a research has showed.

Exposure to tobacco smoke is toxic to the developing brain at a time when it is most vulnerable to environment input, the researchers said.

"Young children have little control over their exposure to household tobacco smoke, which is considered toxic to the brain at a time when its development is exponential," said lead author and Professor Linda Pagani from the University of Montreal in Quebec, Canada. 

Parents who smoke near their children often inadvertently expose them to second- and third-hand smoke. 

Abnormal brain development can result from chronic or transient exposure to toxic chemicals and gases in second-hand tobacco smoke. These compounds eventually solidify and create third-hand smoke. 

In the study, the researchers found compelling evidence that suggests other dangers to developing brain systems that govern behavioural decisions, social and emotional life as well as cognitive functioning.

Anti-social behaviour is characterised by proactive intent to harm others, lack prosocial feelings, and violate social norms. 

Such behaviours include aggression, criminal offences, theft, refusal to comply with authority, destruction of property and is also associated with academic problems in later childhood. 

"These long-term associations should encourage policy-makers and public health professionals to raise awareness among parents about the developmental risks of second-hand smoke exposure," Pagani said. 

For the study, published in the journal Indoor Air, the team examined 1,035 boys and girls born in 1997 and 1998. 

Their parents reported whether anyone smoked at home when their children were aged 1.5 to 7.5 years. At age 12, their children self-reported their anti-social behaviour and academic characteristics.

London, Nov 28 (IANS) Using a combination of artificial intelligence (AI) and brain scanning technology, a team of researchers has developed a novel method that can help remove specific fears from the brain.

The new technique that could read and identify a fear memory can pave way of treating patients with conditions such as post-traumatic stress disorder (PTSD) and phobias, the study said.

Neuroscientists, from the University of Tokyo, developed 'Decoded Neurofeedback' -- which used brain scanning to monitor activity in the brain, and identify complex patterns of activity that resembled a specific fear memory. 

In the study, the team included 17 healthy volunteers in whom a fear memory was created by administering a brief electric shock when they saw a certain computer image. 

Using brain scanner, the researchers monitored the volunteers' mental activity and were able to spot signs of that specific fear memory. Using AI algorithms, they also developed a fast and accurate method of reading the fear.

The findings showed that the volunteers' brains showed brain patterns of that specific fear memory, even when they were resting and not consciously aware of the fear. 

Because the researchers could decode these brain patterns quickly, they gave the participants a reward of small amount of money, so that the fear memories would become associated with rewards. However, the volunteers were told that the reward depended on their brain activity, although they didn't know how. 

At the end of the reward therapy that continued for three days, the team showed the volunteers the pictures previously associated with the shocks.

"We could not identify enhanced activity in the amygdala -- the brain's fear centre. This meant that we were been able to reduce the fear memory without the volunteers ever consciously experiencing the fear memory in the process," said lead author Ai Koizumi from the University of Tokyo. 

The study was published in the journal Nature Human Behaviour.

New Delhi, Nov 28 (IANS) A father's love can have a special influence on young adults, while it can boost the maths grades of the teenage daughter, it may improve the language skills in the son, researchers said.

The study found that fathers from low-income families support their teenagers in ways that result in greater optimism, self-efficacy, and, ultimately, higher achievement at school. 

This is even true for men with low levels of education or those who were not proficient enough in English to help their children with their homework.

"Low-income fathers affect their adolescents' beliefs about themselves and their future, and these beliefs influence their achievement by increasing their determination...," said Marie-Anne Suizzo from the University of Texas in the US.

These positive effects extend to both sons and daughters, albeit in different ways, the study said. 

Experiencing their father's warmth first influences daughters' sense of optimism and then spills over into their feeling more determined and certain about their academic abilities. This in turn leads to better math grades. 

There is a more direct link between the father's involvement and teenage boy's belief in their ability to succeed on the academic front. 

Fathers' involvement with teenage boys' belief in their ability to succeed on the academic front, results in heightened self-confidence and their success in English language, arts classes, the researchers explained.

Counselors and educators should encourage fathers to communicate warmth and acceptance to their children, because of the positive influence these emotions have on their well-being, Suizzo suggested.

In the study, published in the journal Sex Roles, the team analysed 183 sixth-graders from low-income, ethnic minority families. They asked about how optimistic and motivated they were about their schoolwork, and how their experiences were with their fathers. 

New York, Nov 28 (IANS) US researchers have identified neuro-metabolite alterations across the brain that linked stuttering to changes in brain circuits that control speech production and circuits that support attention and emotion.

Stuttering is a speech disorder in which the flow of speech is disrupted by involuntary repetitions and prolongations of sounds and syllables.

The study found that affected brain regions included major nodes of the speech-production network -- associated with the regulation of motor activity, the default-mode network -- involved in the regulation of attention -- and the emotional-memory network -- responsible for regulating emotion.

Attention-regulating portions of the brain are related to control circuits that are important in governing behaviour, the researchers said. 

"People with changes here are more likely to stutter and have more severe stuttering. And emotions like anxiety and stress also tend to make stuttering worse, likely because this network interacts with language and attention control circuits," said lead author Bradley S. Peterson, Director at Children's Hospital Los Angeles (CHLA) in the US. 

For the study, the scientists performed proton shift imaging of the brain in 47 children and 47 adults, both with and without stuttering.

The results confirmed that disturbances in neuronal or membrane metabolism contribute to the development of stuttering.

The study was published online in the Journal of the American Medical Association (JAMA).