Knowledge Update

​New York, March 25 (IANS) Turmeric, an essential ingredient that spices up an Indian curry, may help fight drug-resistant tuberculosis, new research has found.

In Asia, turmeric is already used to treat many health conditions and it has anti-inflammatory, antioxidant and perhaps even anticancer properties, the study pointed out.

Researchers have now found that by stimulating human immune cells called macrophages, curcumin - a substance in turmeric -- was able to successfully remove Mycobacterium tuberculosis, the causative bacterium of tuberculosis (TB), from experimentally infected cells in culture. 

The process relied on inhibiting the activation of a cellular molecule called nuclear factor-kappa B.

"Our study has provided basic evidence that curcumin protects against Mycobacterium tuberculosis infection in human cells," said lead author of the study Xiyuan Bai from the University of Colorado School of Medicine in the US.

The findings appeared in the journal Respirology. 

The ability of curcumin to modulate the immune response to Mycobacterium tuberculosis points to a potential new tuberculosis treatment that would be less prone to the development of drug resistance.

"The protective role of curcumin to fight drug-resistant tuberculosis still needs confirmation, but if validated, curcumin may become a novel treatment to modulate the host immune response to overcome drug-resistant tuberculosis," Bai noted.​

​Washington, March 25 (IANS) In a nod to extraterrestrial mountaineers of the future, scientists working on NASA's Cassini mission have identified the highest point on Saturn's largest moon Titan.

Titan's tallest peak is 10,948 feet high and is found within a trio of mountainous ridges called the Mithrim Montes.

The researchers found that all of Titan's highest peaks are about 10,000 feet in elevation.

The study used images and other data from Cassini's radar instrument, which can peer through the obscuring smog of Titan's atmosphere to reveal the surface in detail.

"It's not only the highest point we've found so far on Titan, but we think it's the highest point we're likely to find," said Stephen Wall, deputy lead of the Cassini radar team at NASA.

Most of Titan's tallest mountains appear to be close to the equator.

The researchers identified other peaks of similar height within the Mithrim Montes, as well as in the rugged region known as Xanadu.

"As explorers, we're motivated to find the highest or deepest places partly because it's exciting. But Titan's extremes also tell us important things about forces affecting its evolution," added Jani Radebaugh, a Cassini radar team associate at Brigham Young University in Utah.

Mountains and cliffs on Earth usually are found in locations where forces have shoved the surface upward from underneath.

The Himalaya and Andes Mountains are examples of places where interior forces are at work today.

Cassini has found that Titan also has rain and rivers that erode its landscape.

According to Radebaugh, the process probably proceeds much more slowly on Titan than on the Earth because, at 10 times Earth's distance from the sun, there is less energy to power erosive processes in the moon's atmosphere.

The fact that Titan has significant mountains suggests that some active tectonic forces could be affecting the surface, for example, related to Titan's rotation, tidal forces from Saturn or cooling of the crust.

The next step for the researchers will be trying to figure out what could produce such tall peaks on an icy ocean world.

"There is lot of value in examining the topography of Titan in a broad, global sense, since it tells us about forces acting on the surface from below as well as above," said Radebaugh.

The results were presented at the 47th annual lunar and planetary science conference in Texas on Thursday.​

​London, March 25 (IANS) Eating a diet rich in vitamin C may slow the progression of cataract -- a condition that may lead to blindness, reveals a study, adding that environmental factors and diet also influence cataract more than genetic factors.

The findings showed that those participants who had a higher intake of vitamin C were associated with a 33 percent risk reduction of cataract progression and had "clearer" lenses 10 years after the study than those who had consumed less vitamin C as part of their diet.

"The findings of this study could have significant impact, particularly for the ageing population globally, by suggesting that simple dietary changes such as increased intake of fruit and vegetables as part of a healthier diet could help protect them from cataracts," said lead study author Chris Hammond from the Kings College London.

"While we cannot avoid getting older, diabetes and smoking are also risk factors for this type of cataract, and so a healthy balanced diet and lifestyle generally should reduce the risk of needing a cataract operation," Hammond added.

Cataract is a common condition in which the lens of the eye becomes cloudy as a result of oxidation over time. 

The study, published in the journal Ophthalmology, looked at the progression of cataracts in the eyes of 324 pairs of female twins over 10 years by examining photographs of the participant's lenses that allowed them to analyse the level of opacity of the lens in detail. 

Participant intake of vitamin C was also measured using a food questionnaire.

The study found that environmental factors -- including diet -- influenced cataract more than genetic factors, which only explained a third of the change in lens opacity.

It is thought that increased intake of vitamin C has a protective effect on cataract progression by increasing the vitamin C available in the eye fluid.

"The human body cannot manufacture vitamin C, so we depend on vitamins in the food we eat. We did not find a significantly reduced risk in people who took vitamin tablets, so it seems that a healthy diet is better than supplements,” added study's first author Kate Yonova-Doing.​

​New York, March 25 (IANS) What has brain to do with glucose metabolism? A lot, say researchers, suggesting that not just your pancreas, a group of neurons in the hypothalamus area also plays a vital role in maintaining blood glucose levels.

The team from Rockefeller University and Rensselaer Polytechnic Institute have used magnetic forces to remotely control the flow of ions into specifically targeted cells in mice.

Jeffrey Friedman, head of the laboratory of molecular genetics, and colleagues successfully employed this system to study the role of the central nervous system in glucose metabolism.

“These results are exciting because they provide a broader view of how blood glucose is regulated -- they emphasize how crucial the brain is in this process," Friedman said.

“Having a new means for controlling neural activity, one that doesn't require an implant and allows you to elicit rapid responses, fills a useful niche between the methods that are already available,” added the scientist in a paper which appeared in the journal Nature.

The new study is the first to turn neurons on and off remotely with radio waves and magnetic fields.

Using this novel method, the researchers investigated the role these glucose sensing neurons play in blood glucose metabolism.

Hormones released by the pancreas, including insulin, maintain stable levels of glucose in the blood.

A region of the brain called the ventromedial hypothalamus was thought to play a role in regulating blood glucose.

Friedman and colleagues found that when they switched these neurons on with magnetic forces, blood glucose increased, insulin levels decreased, and behaviourally, the mice ate more.

When they inhibited the neurons, on the other hand, the opposite occurred, and blood glucose decreased.

“We tend to think about blood glucose being under the control of the pancreas, so it was surprising that the brain can affect blood glucose in either direction to the extent that it can," Friedman noted.

The system has several advantages that make it ideal for studies on other circuits in the brain or elsewhere.

It can be applied to any circuit, including dispersed cells like those involved in the immune system.

In addition to its utility as a research tool, the technique may also have clinical applications.

“Depending on the type of cell we target and the activity we enhance or decrease within that cell, this approach holds potential in development therapies for metabolic and neurologic diseases,” explained Jonathan Dordick from Rensselaer.​

New York, March 25 (IANS) Do you love Swiss chocolates more than those from Indonesia? You may thank diverse yeast population for that particular taste as researchers have found that those differences may play an important role in the characteristics of chocolate and coffee from different parts of the world.

In comparison to the yeasts found in vineyards around the world, those associated with coffee and cacao beans show much greater diversity, the findings showed.

"Our study suggests a complex interplay between human activity and microbes involved in the production of coffee and chocolate," said Aimee Dudley of the Pacific Northwest Diabetes Research Institute in Seattle, US. 

"Humans have transported and cultivated the plants, but at least for one important species, their associated microbes have arisen from transport and mingling in events that are independent of the transport of the plants themselves," Dudley noted.

Coffee and cacao trees originally grew in Ethiopia and the Amazon rain forest. They are now widely cultivated across the "bean belt" that surrounds the equator. 

After they are picked, both cacao and coffee beans are fermented for a period of days to break down the surrounding pulp. 

This microbe-driven process also has an important influence on the character and flavour of the beans.

To explore further, the researchers bought unroasted coffee and cacao beans grown in Central and South America, Africa, Indonesia or the Middle East and isolated the associated yeast in their Seattle laboratory. 

Genetic analysis of those yeast strains revealed that yeasts from coffee and cacao beans were substantially more diverse than the wine yeasts. 

Interestingly, the genetic signatures of the yeast strains strongly clustered according to the geographic origin of the beans, the study said.

In fact, this association was so strong that they were able to accurately determine the origin of the beans solely from the DNA sequences of their associated yeasts, Dudley said.

The findings appeared in the journal Current Biology.

The findings showed that the yeast strains associated with coffee and cacao have multiple, independent origins. 

The researchers believe that the findings could lead to improvements in chocolate and coffee. ​

​London, March 22 (IANS) The time and date of birth determines our horoscope and the characteristics associated with it. However, a new study reveals a specific marker in our genes, which gives us the horoscope by the seasons of birth and shows how it influences so many things in our life.

The study showed that the season a person is born in influences a wide range of things: From risk of allergic disease, to height and lifespan. 

But, relatively little is known about how a one-time exposure, such as the season of birth, could hold lasting effects.

A specific marker that has been discovered on human deoxyribonucleic acid (DNA) has been instrumental in linking the season of birth to risk of allergy in later life.

“It might sound like a horoscope by the seasons, but now we have scientific evidence for how that horoscope could work. Because season of birth influences so many things, the epigenetic marks discovered in this study could also potentially be the mechanism for other seasonally influenced diseases and traits too, not just allergy,” said lead author Gabrielle Lockett from University of Southampton in Britain.

The findings, published in the journal Allergy, revealed that particular epigenetic marks (specifically, DNA methylation) were associated with season of birth and still present 18 years later. 

Also, this epigenetic marks exposed the link to allergic disease, for example people born in autumn had an increased risk of eczema compared to those born in spring.

“Epigenetic marks are attached onto DNA, and can influence gene expression (the process by which specific genes are activated to produce a required protein) for years, maybe even into the next generation,” explained one of the researchers John Holloway, professor at Southampton University.

While these results have clinical implications in mediating against allergy risk, we are not advising altering pregnancy timing,” Holloway added.

The team conducted epigenetic scanning on DNA samples from a group of people born on the Isle of Wight in Britain and the results were validated in a cohort of Dutch children.​

A new technique developed by a team of chemists at Stanford University has shown promise to be thousands of times more sensitive than current techniques to diagnose diseases -- whether it is a cancer or a virus like HIV.

Found effective in laboratory experiments, the technique, described in the journal ACS Central Science, is now being put to test in real-world clinical trials.

When a disease begins growing in the body, the immune system responds by producing antibodies.

Fishing these antibodies or related biomarkers out of the blood is one way that scientists infer the presence of a disease.

This involves designing a molecule that the biomarker will bind to, and which is adorned with an identifying "flag." Through a series of specialized chemical reactions, known as an immunoassay, researchers can isolate that flag, and the biomarker bound to it, to provide a proxy measurement of the disease.

The new technique, developed in the lab of Carolyn Bertozzi, professor of chemistry at Stanford, augments this standard procedure with powerful DNA screening technology.

In this case, the chemists replaced the standard flag with a short strand of DNA, which can then be teased out of the sample using DNA isolation technologies that are far more sensitive than those possible for traditional antibody detections.

The researchers tested their technique, with its signature DNA flag, against four commercially available tests for a biomarker for thyroid cancer.

It outperformed the sensitivity of all of them, by at least 800 times, and as much as 10,000 times.

By detecting the biomarkers of disease at lower concentrations, physicians could theoretically catch diseases far earlier in their progression.

"The thyroid cancer test has historically been a fairly challenging immunoassay, because it produces a lot of false positives and false negatives, so it wasn't clear if our test would have an advantage," said study co-author Peter Robinson.

"We suspected ours would be more sensitive, but we were pleasantly surprised by the magnitude," Robinson noted.

Based on the success of the thyroid screening, the group has won a few grants to advance the technique into clinical trials for screening other diseases including HIV.​

New York, March 20 (IANS)

​London, March 20 (IANS) A team of German scientists has found out what actually happens if we try to remember things that took place years or decades ago?

The study revealed that the neural networks involved in retrieving very old memories are quite distinct from those used to remember recent events.

"For the very first time we were able to show that the retrieval of old and recent memories are supported by distinct brain networks," said Magdalena Sauvage, professor at Ruhr-University Bochum in Germany.

When we remember events which occurred recently, the hippocampus -- the portion of the brain, thought to be the centre of emotion, memory, and the autonomic nervous system -- is activated, said the paper appeared in the journal eLIFE.

Hippocampus contains the cornu ammonis regions 1 and 3 (CA1 and CA3), which plays a major role in retrieving recent memories.

For the study, the team monitored brain activity in mice during the retrieval of memories that are one day to one year old - e.g. up to the mouse-equivalent of 40 human years.

For their study they applied a high-resolution molecular imaging technique, which detects the expression of a particular gene tied to plasticity processes and this way sheds light on cognitive processes.

The CA3 region, believed to be the place of memory storage in the hippocampus, no longer plays a role when we remember very old memories.

Rather, the involvement of the CA1 region persists and the cortical areas -- largest part of the brain -- adjacent to the hippocampus become involved.

The reason for the differential involvement of the hippocampal sub-regions could lie in the mechanisms supported by CA3.

In CA3, memories can be retrieved on the basis of single features of an original memory, which are used as cues. 

"Since the memory for single features degrades over time, we speculate that they might ultimately be of no more use as cues, hence retrieving memory would then essentially rely on CA1 and other processes taking place in the parahippocampal region of the brain," explained Sauvage.​

​Cape Town, March 20 (IANS) South Africans actively took part in the Earth Hour campaign by switching off lights from 8.30-9.30 p.m., saving an average of 515 mw electricity during the hour, authorities said on Sunday.

As part of its support for the Earth Hour campaign, the country's electricity utility Eskom measured the reduction in electricity used during the hour on Saturday, Xinhua reported.

"We would like to encourage people to take action beyond this one hour, and to make energy efficiency and environmental conservation part of their daily lifestyles," Eskom said.

People are encouraged to reduce their energy consumption every day by using electricity efficiently, and switching off all non-essential lights and household appliances, said the utility.

Commercial customers, particularly shopping centres and office blocks, can also make a big difference by switching off non-essential lights and not leaving office equipment such as computers in standby mode after hours, it added.

Earth Hour is an annual global event, initiated in Sydney, in 2007 to encourage people to switch off lights and unused appliances for an hour as a symbolic demonstration of their commitment to action against climate change.​