Knowledge Update

New York, Sep 23 (IANS) A gene that can potentially reduce female mosquitoes has been identified by a team of US researchers. That's good news for malaria, dengue, Zika control. The bad news is this happens over generations of moquitoes.

Female mosquitoes draw human blood to facilitate their egg production and are also the prime carriers of the pathogens that cause deadly diseases like malaria, Zika, and dengue fever.

The study found that placing a particular Y chromosome gene on the autosomes of Anopheles stephensi mosquitoes -- a species responsible for transmitting malaria -- killed off 100 per cent of all female embryos that inherited this gene.

The extra copy of this gene, which the researchers call Guy1, is passed on to both sexes but only males survive, the study said. 

"The Guy1 protein is a strong candidate of the male determining factor in Anopheles stephensi," said Zhijian "Jake" Tu, Professor at the Virginia Polytechnic Institute and State University in the US.

"The extra copy of the Guy1 gene is only passed down to half of the progeny, leaving some females among the mosquitoes that did not inherit the gene in the next generation," added Frank Criscione from Virginia Polytechnic Institute and State University in the US.

In order to produce all male offspring, all progeny needs to inherit this extra copy of Guy1, which can potentially be achieved by using genome-editing, the researchers stated, in the paper published in the journal eLife.

London, Sep 23 (IANS) Researchers have found a potential new way of stopping one of the most aggressive types of brain tumour from spreading, which could also lead the way to better patient survival.

Glioblastoma, which is one of the most common types of malignant brain tumours in adults, grow fast as well as spread easily. 

The tumour has threadlike tendrils that extend into other parts of the brain making it difficult to remove it all, the study from the University of Southampton in Britain said.

The findings suggest that by blocking specific enzymes called ADAM10 and ADAM17, the tumour can be stopped from growing and spreading. 

It also moves the cancer cells away from the place where they were growing which could allow them to be removed through traditional cancer treatments such as radiotherapy, chemotherapy or surgery, the researchers noted.

"Glioblastoma is a devastating disease which is often untreatable. We have found that blocking ADAMs may lead to reduced tumour growth and less recurrence following conventional treatments, improving the chance of complete surgical removal and improving survival rates," said Sandrine Willaime-Morawek, Lecturer at the University of Southampton in Britain.

The current treatment regimens are ineffective against the small population of cancer stem cells residing in the tumourigenic niche. 

These tumours are highly proliferative and infiltrative resulting in a median patient survival of only 14 months from diagnosis.

However, the new therapeutic approach could involve the removal of these cells from the microenvironment that maintains the cancer stem cell phenotype, the researchers concluded in the paper published in the journal Molecular Neurobiology. 

Jerusalem, Sep 23 (IANS) Using a membrane extract from spinach leaves, Israeli researchers have developed a bio-photo-electro-chemical (BPEC) cell device that produces electricity and hydrogen from water using sunlight.

The BPEC cell is based on the naturally occurring process of photosynthesis in plants in which light drives electrons that produce storable chemical energetic molecules that are the fuels of all cells in the animals and plants.

The BPEC cell and plant membranes absorbs sunlight and convert it into a flow of electrons. In order to utilise photosynthesis for producing electric current, the researchers added an iron-based compound to the solution. 

This compound mediates the transfer of electrons from the biological membranes to the electrical circuit, enabling the creation of an electric current in the cell.

The electrical current can also be channelled to form hydrogen gas through the addition of electric power from a small photovoltaic cell that absorbs the excess light. 

This makes possible the conversion of solar energy into chemical energy that is stored as hydrogen gas formed inside the BPEC cell, suggested the study published in the journal Nature Communications.

This energy can be also converted into heat and electricity when necessary by burning the hydrogen, in the same way hydrocarbon fuels are used.

However, unlike the combustion of hydrocarbon fuels -- which emit greenhouse gases (carbon dioxide) into the atmosphere and pollute the environment -- the product of hydrogen combustion is clean water. 

Therefore, this is a closed cycle that begins with water and ends with water, allowing the conversion and storage of solar energy in hydrogen gas, which could be a clean and sustainable substitute for hydrocarbon fuel.

"The combination of natural (leaves) and artificial (photovoltaic cell and electronic components), and the need to make these components communicate with each other, are complex engineering challenges that required us to join forces," said Avner Rothschild, researcher at the Technion-Israel Institute of Technology, at Haifa, in Israel.

​New York, Sep 24 (IANS) When strict deadlines are in place, workers tend to complete their tasks at the last minute, often leading to lower quality outcomes, a new study shows.

In the study, the researchers from Syracuse University examined the impact of deadlines using large-scale patent data. 

The findings showed that patent applications tend to cluster around the end of the month and those month-end applications are, on average, more complex. 

Moreover, the work quality is lower for tasks completed at month-end.

"Our study is valuable because it examined work flows, task complexity and work quality across thousands of firms for several decades," said Natarajan Balasubramanian, associate professor at the Whitman School of Management at Syracuse University in New York, US. 

"We now have novel, large-scale evidence for the effect of deadlines on job-flows and have quantifiably demonstrated the negative effects deadlines can have on work quality," Balasubramanian added.

The study suggests that managers need to be vigilant about understanding the negative work quality effects of using deadlines, and should review to fully discern if the benefit of accelerating projects outweighs the possible negative effects on work quality, the researchers said.

"Further, to the extent that the use of deadlines leads to poorer-quality and 'fuzzier' patents, deadlines have broader implications for the process of technological innovation," Balasubramanian noted.

The study is forthcoming in Management Science.

​London, Sep 24 (IANS) Infants whose mothers had a higher level of a particular type of vitamin B during pregnancy may be at a lower risk of developing eczema -- inflammation of the skin -- researchers have found.

The study, from the University of Southampton in Britain, is the first to link maternal serum levels of nicotinamide -- a naturally occurring form of vitamin B3 -- and related metabolites to the risk of atopic eczema -- the most common form of eczema -- in the child.

The results showed that offspring of mothers with higher levels of nicotinamide had a 30 per cent lower chance of developing atopic eczema at 12 months. 

There was an even stronger association with higher levels of anthranilic acid, a tryptophan metabolite.

Nicotinamide and related nutrients are important for the body's immune responses and energy metabolism, the study said.

Levels of nicotinamide are maintained through intake of foods such as fish, meat, chicken, mushrooms, nuts and coffee as well as tryptophan, an amino acid found in most proteins. 

Nicotinamide can improve the overall structure, moisture and elasticity of skin and therefore could potentially alter the disease processes associated with eczema, the researchers noted. 

Further, the study showed a gradual association between higher maternal nicotinamide and anthranilic acid levels and a lower risk of atopic eczema, suggesting that the development of eczema is not simply prevented by the presence of these nutrients.

"Nicotinamide cream has been used in the treatment of eczema but the link between the mother's levels of nicotinamide during pregnancy and the offspring's risk of atopic eczema has not been previously studied. The findings point to potentially modifiable influences on this common and distressing condition," said lead researcher Sarah El-Heis from the University of Southampton.

For the study, published in Clinical and Experimental Allergy, the team assessed the amount of nicotinamide and related tryptophan metabolites during pregnancy in 497 women who took part in the Southampton Women's Survey. 

The team studied the rates of eczema in their children at ages 6 and 12 months.

The study supports the concept that eczema partly originates as a baby develops in the womb and could reveal ways of reducing the risk of the skin condition, the researchers said.

"More research is needed to investigate this interesting association, but the findings are further evidence of the potential benefits of eating a healthy balanced diet during pregnancy," added Keith Godfrey, professor at the University of Southampton.

New York, Sep 22 (IANS) Smoking, a leading preventable cause of deaths worldwide, impacts the human DNA for more than 30 years even after one quits, a study has found.

The findings showed that smoking leaves its "footprint" on the human genome in the form of DNA methylation -- a process by which cells control gene activity.

Methylation, one of the mechanisms of the regulation of gene expression, affects what genes are turned on, which has implications for the development of smoking-related diseases.

"Our study has found compelling evidence that smoking has a long-lasting impact on our molecular machinery, an impact that can last more than 30 years," said lead author Roby Joehanes, instructor at Harvard Medical School in Massachusetts, US.

For people who stopped smoking, the majority of DNA methylation sites returned to the levels that are seen in those who never smoked within five years of quitting it.

However, some DNA methylation sites persisted even after 30 years of quitting.

Even decades after stopping, former smokers are at long-term risk of developing diseases including cancers, chronic obstructive pulmonary disease, and stroke. 

The most statistically significant methylation sites were linked to genes enriched for association with numerous diseases caused by cigarette smoking, such as cardiovascular diseases and certain cancers.

DNA methylation could be an important sign that reveals an individual's smoking history, and could provide researchers with potential targets for new therapies, the researchers said.

For the study, the team conducted a meta-analysis of DNA methylation sites across the human genome using blood samples taken from nearly 16,000 participants.

The researchers compared DNA methylation sites in current and former smokers to those who never smoked.

Smoking-associated DNA methylation sites were associated with more than 7,000 genes, or one-third of known human genes.

The researchers suggest that some of these long-lasting methylation sites may be marking genes potentially important for former smokers who are still at increased risk of developing certain diseases. 

The discovery of smoking-related DNA methylation sites raises the possibility of developing biomarkers to evaluate a patient's smoking history, as well as potentially developing new treatments targeted at these methylation sites.

The results were published in the journal Circulation: Cardiovascular Genetics.

Washington, Sep 22 (IANS) The microbes that people have brought with them so far to the International Space Station -- and left behind -- are the focus of a new collaborative research opportunity from NASA and the non-profit Alfred P. Sloan Foundation.

Microbiome research on the space station is an important area of research for NASA as it prepares astronauts for future long duration spaceflight. 

"NASA is incredibly excited to partner with the Sloan Foundation through a Space Act Agreement to look at the microbiome of the space station to better understand how to control the microbial environment in future human exploration spacecraft," David Tomko, space biology programme scientist at NASA, said in a statement on Thursday.

More than 200 people have crossed the airlock threshold to the International Space Station to conduct research that benefits people on Earth and NASA's ambitious plan to send humans to Mars.

Humans bring microbes everywhere they go ? some of which reside inside the body, such as the intestinal tract. Others are outside the body on skin and clothes, for example. 

When these collective microbial communities enter a human-made environment like the International Space Station they create their own microbial ecosystem known as the Microbiome of Built Environments (MoBE).

NASA is seeking proposals from postdoctoral fellows to analyse the microbial communities inside the space station to determine how the communities colonise, adapt and evolve. 

The researchers will have access to a collection of space station microbial samples gathered over a decade or more, and archived at NASA's Johnson Space Center in Houston.

​New York, Sep 22 (IANS) Children and teenagers who are obese have different microorganisms living in their digestive tract than those who are lean, according to a new study.

The study finds gut microbiota or gut flora is closely related to fat distribution in children and teenagers.

"Our findings show children and teenagers with obesity have a different composition of gut flora than lean youth," said Nicola Santoro, Researcher at the Yale University in Connecticut, US. 

"This suggests that targeted modifications to the specific species composing the human microbiota could be developed and could help to prevent or treat early-onset obesity in the future," said Santoro. 

The study examined gut microbiota and weight in 84 children and teenagers, who were between seven and 20 years old. The participants included 27 obese, 35 severely obese, seven overweight and 15 with normal weight.

The researchers analysed the participants' gut microbiota and performed an MRI to measure body fat partitioning. They also tested blood samples and reviewed their three-day food diary.

They found eight groups of gut microbiota that were linked to the amount of fat in the body. Four of the microbial communities were seen flourishing in children and teens with obesity as compared to their normal-weight counterparts.

Smaller amounts of the other four microbial groups were found in participants, who were obese compared to children and teenagers of normal weight. 

The gut microbiota found in youth, who were obese, tended to be more efficient at digesting carbohydrates than those found in teenagers and children's gut from normal weight category.

In addition, the children with obesity had higher levels of short chain fatty acids in the blood than those of normal weight. 

The study found short chain fatty acids -- produced by some gut bacteria -- to be associated with the production of fat in the liver.

"Our research suggests that short chain fatty acids can be converted to fat within the liver and then accumulate in the fat tissue," said Santoro.

The researchers said this association could signal that children with certain gut bacteria face a long-term risk of developing obesity. 

The study was published in the journal Clinical Endocrinology and Metabolism.

Washington, Sep 23 (IANS) Astronomers using NASA's Hubble Space Telescope, and a trick of nature, have confirmed the existence of a planet orbiting two stars in the system OGLE-2007-BLG-349, located 8,000 light-years away towards the centre of our galaxy.

The planet orbits roughly 483 million kilometres from the stellar duo, about the distance from the asteroid belt to our sun, NASA said in a statement on Thursday.

It completes an orbit around both stars roughly every seven years. The two red dwarf stars are a mere 11 million miles apart, or 14 times the diametre of the moon's orbit around Earth.

The Hubble observations represent the first time such a three-body system has been confirmed using the gravitational microlensing technique.

Gravitational microlensing occurs when the gravity of a foreground star bends and amplifies the light of a background star that momentarily aligns with it. The particular character of the light magnification can reveal clues to the nature of the foreground star and any associated planets.

The objects were discovered in 2007 by an international collaboration of five different groups. These ground-based observations uncovered a star and a planet, but a detailed analysis also revealed a third body that astronomers could not definitively identify.

"The ground-based observations suggested two possible scenarios for the three-body system: a Saturn-mass planet orbiting a close binary star pair or a Saturn-mass and an Earth-mass planet orbiting a single star," explained the paper's first author David Bennett of the NASA Goddard Space Flight Center in Greenbelt, Maryland. 

The sharpness of the Hubble images allowed the research team to separate the background source star and the lensing star from their neighbours in the very crowded star field. 

The Hubble observations revealed that the starlight from the foreground lens system was too faint to be a single star, but it had the brightness expected for two closely orbiting red dwarf stars, which are fainter and less massive than our sun. 

"So, the model with two stars and one planet is the only one consistent with the Hubble data," Bennett said.

NASA's Kepler probe has discovered 10 other planets orbiting tight binary stars, but these are all much closer to their stars than the one studied by Hubble.

The team's results have been accepted for publication in The Astronomical Journal.

​London, Sep 23 (IANS) Dysregulation of the DNA -- an important cause of ageing -- does not take place in some people, while in some individuals, the DNA appears to be youthful despite their advanced years.

This dysregulation of the DNA can act as a precursor to various diseases, including cancer, and on the other hand, youthful DNA may prevent the disease, the researchers have found.

The DNA of young people is regulated to express the right genes at the right time. With the passing of years, the regulation of the DNA gradually gets disrupted, which is an important cause of ageing, the study said. 

"The study suggests that the dysregulation of the DNA is a fundamental process that could push the risk of different diseases in the wrong direction," said Bas Heijmans, an epigeneticist at the Leiden University Medical Center in the Netherlands. 

Further, in cancer cells changes in the regulation of the DNA at the same sites was found as if the differences occurring with ageing were a precursor of the disease, the study said. 

"We therefore want to study whether a dysregulated DNA increases the risk of different forms of cancer and, conversely, a 'youthful' DNA is protective," added Roderick Slieker from Leiden University Medical Center.

For the study, the researchers charted the regulation of the DNA of over 3,000 people by measuring the level of methylation -- a process by which cells control gene activity -- at close to half a million sites across the human DNA. 

Not everyone in the study showed equal evidence of an age-related dysregulation of the DNA. They were looking for sites where the difference in regulation increased between people as life progressed. 

Some elderly people had DNA that was regulated as if they were still 25 years old. In these individuals, genes characteristic of the ageing process were much less active, the researchers said.

"We believe we may have caught the ageing process in the act. The dysregulation of the DNA that we discovered went hand in hand with higher activity in genes that continuously try to repair damage to cells. This process is not fully effective and in the long run leads to ageing," Heijmans explained, in the research published in the journal Genome Biology.