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Friday, 24 November, 2017 - 13:54

Venkata S. Murthy Gudlavalleti from the Indian Institute of Public Health, Hyderabad has been studying childhood blindness in the country to understand the causes, severity and extent of the disability.

According to a World Health Organization estimate, globally, around 19 million children are visually impaired, and 1.4 million of those are blind. In India, the number is close to 8 out of every 10000 children. As childhood blindness is also considered as an important indicator of the state of child health and primary care services in a country, the numbers reflect a larger issue of lack of diagnostic and care centres in the country.

Dr. Gudlavalleti set out to find the prevalence of childhood blindness and some of the common causes for the disability. Childhood blindness is an important parameter, since children born with the disease then must live their lives without sight, a parameter termed as blind years lived. It is found that after adult cataract, a condition which causes blurred vision due to the lens in the eye becoming opaque, childhood blindness is next, in terms of blind years lived. This means the children have to survive for long without the ability of sight.

Due to lack of available data on the prevalence, Dr. Gudlavalleti used under-five mortality rates, or the number of infants dying before reaching an age of five, as an approximate proxy for the prevalence of the disability in low and middle-income families. The study also found whole globe lesions, corneal scarring, retinal pathology, and afflictions of the lens to be some of the common causes for blindness in children. However, data was again lacking in around 60% of the region in South Asia to determine a specific cause for the blindness. The study also found that the number of avoidable cases of blindness was around 50%.

The study points to a need for comprehensive eye care centres for both, avoidable and incurable blindness, while also stressing on early diagnostics, required to identify the disability early on and prompt management to address the scourge of childhood blindness.

Section: General, Science, Health Source: Link
Thursday, 23 November, 2017 - 15:39

An international team of scientists from University of Glasgow, UK, Chinese Academy of Sciences, China, Institute of Solar Terrestrial Physics, Russia, West Kentucky University, USA, National Academy of Sciences of Ukraine, Ukraine and Indian Institute of Science, Education and Research (IISER)- Pune, India have proposed a novel method to accurately study radio observations of the sun.

While staring at the sun, a question that sometimes pop-up is, how do we know what the sun is made of, if the light from the sun is blindingly bright to our instruments? We study such objects by looking at them through forms of light other than visible light. This could include radio, Infrared, x-rays and UV rays. Solar radio observations or observing the radio waves emitted by the star, especially, could reveal unique insights into the outer solar atmosphere.

One challenge in studying the radio waves, however, is distinguishing the intrinsic properties of the source of the radio waves from the effects of radio wave propagation. As the corona of the Sun, an area of intense magnetic fields and high temperatures, affects the propagation of the radio waves, studying the source of the waves would require eliminating the effects of the corona, during calculations.

In the new study, the scientists have been able to characterize the fine structures produced during a radio burst or a solar flare emitting radio waves. Using Low Frequency Array telescopes, that provides high-time resolution images and allows imaging the sun at scales much smaller than that of radio wave propagation on the sun, the scientists were able to quantitatively characterize the frequency and spatial properties of the propagating radio wave on the solar surface.

Their observations have shown that the spatial characteristics or the manner in which a wave propagates is guided by the effects of radio wave propagation more than that of the intrinsic emission source of the waves. These observations could allow for better models of the solar surface, with a better accuracy of source brightness temperatures, giving us an accurate picture of our parent star- the Sun.

Section: General, Science, Technology Source: Link
Wednesday, 22 November, 2017 - 13:54

A team, including scientists from University of California, Santa Barbara, USA and Indian Institute of Technology -Kanpur, have developed a new technique to reduce the amount of carbon dioxide produced while making hydrogen. The new method not only reduces the amount of greenhouse gases, but also allows for the reuse of carbon that is produced in the reaction.

Hydrogen fuel cells are hailed as the best alternative to fossil fuels, packing more energy than the latter and being much cleaner, as the only byproduct produced is water. Large scale production and storage of hydrogen, however, remains a challenge with research in the area very active.

In the new study, the scientists wanted to reduce the amount of carbon dioxide produced while making hydrogen through methane pyrolysis. Conventionally, a process called steam reformation of methane, where high temperature steam reacts with methane to produce hydrogen, in the presence of a solid catalyst, has been employed to produce hydrogen. The high temperature reaction also releases carbon dioxide- a greenhouse gas, which in turn reacts with the solid catalyst. Over time, the carbon deposited over the solid catalyst renders it inactive, requiring a change of the catalyst.

For their new method, the scientists replaced the solid catalyst with a mixture of active catalysts of methane, like nickel, palladium and platinum, and low-melting temperature metals, like indium, gallium, and tin. The mixture produces a molten metal alloy which can act as a catalyst for the pyrolysis of methane into hydrogen and carbon. Unlike conventional methods, the molten metal alloy allows the insoluble carbon produced during the methane pyrolysis, to float up through the alloy to form a layer at the top that can be skimmed off. Once removed, the carbon can be stored or incorporated into composite materials. As the carbon floats to the surface and does not stick to the catalyst, the catalyst does not get deactivated over time, avoiding replacement of the catalyst. The new method allowed for a conversion of 95% of the methane into pure hydrogen, with no carbon dioxide or other by-products, providing a cleaner way of producing the clean energy source- hydrogen.

 

Section: General, Science, Technology Source: Link
Tuesday, 21 November, 2017 - 12:56

In a first, scientists from Indian Institute of Technology Ropar (IIT RPR), Rupnagar, University of Edinburgh and Indian Institute of Technology Kharagpur (IIT Kgp) have demonstrated a phenomenon called ‘inverse Marangoni effect’ using nanodroplets of pure water.

A stationary drop of liquid, like water, will start moving from hotter to colder regions or from region with lower to higher surface tension. This is called as the Marangoni effect. A drop of water in an unevenly heating frying pan, will start darting around frantically, partly due to the Marangoni effect.  The effect is seen in most pure liquids, like water, for which the surface tension-- the property that makes liquids like water form a parabolic droplet instead of spreading flat on a surface, decreases with an increase in temperature.

For the study, the scientists set out to demonstrate the inverse of the Marangoni effect using pure water. Although the inverse effect has been observed in liquid mixtures, this was the first time it was demonstrated in a pure liquid like water.

To demonstrate this, they had to drive an immobile droplet in the opposite direction of the surface tension gradient. With the help of simulations of molecular dynamics, the scientist studied the effect of a changing surface tension coefficient and changing wetting parameter on a surface with different wettability’s. Wetting is the ability of a liquid to maintain contact with the surface, and wettability of a surface, tells us how much a liquid can stick to that surface. The scientist studied the effect of these changing parameters with changing temperatures.

The studies show that pure liquids do indeed demonstrate inverse Marangoni effect at small enough scales, where the inertial effects of the droplet are negligible. The scientists used nanodroplets of water, droplets with a diameter of a billionth of a meter. At these scales the inertial properties of the droplets are negligible enough for the changing surface tension and wetting parameters to drive the droplet against a temperature gradient. The discovery could be used for processes like electronic chip cooling to efficiently manage the heat, by moving droplets into warmer regions.

Section: General, Science Source: Link
Monday, 20 November, 2017 - 15:39

Scientists from the National Institute of Plant Genome Research have identified a protein that helps bacteria consume fungi.

Bacteria are single cellular life forms that have been on the Earth for approximately 3.5 billion years. In all their time on Earth they have adapted to different climates and region, interacting with all other life forms that subsequently evolved on the planet.

Like all organisms, bacteria too must compete with others sharing their environment, for sources of nutrition. Hence many bacteria are observed to release antifungal metabolites and toxins, to compete with fungi. Mycophagy is a process which takes this interaction a step further. Through their various antibiotics, toxins and enzymes bacteria can digest and consume fungi themselves.

In their recent study the scientists have isolated the bacterium Burkholderia gladioli strain NGJ1 from rice seeds and studied its antifungal effect on Ralstonia solanacearum, a fungal pathogen of rice plants. Through different confrontation assays experiments, the bacteria were allowed to come in contact with the fungal species.

The experiments showed that after a week of exposure, the bacteria were seen growing on the fungus. Under normal conditions the fungus is known to produce sclerotia, which are hard dormant bodies which store nutrients for the fungi in extreme conditions. In the presence of the bacteria only a few sclerotia were produced which were unable to germinate.

To understand the mechanism through which the bacteria were attacking the fungal cells, the scientists genetically modified the bacteria to not express the type three secretion system (T3SS). T3SS is a protein found in pathogenic bacteria. In the absence of this system the bacterium lost the ability of mycophagy. Using online tools, the scientists further identified that the protein Bg_9562 in the T3SS was similar to proteins in viral tails. The purified protein Bg_9562 was also seen to have a broad spectrum anti-fungal activity that could potentially be harnessed against fungal agents that are pathogenic to crops.

Section: General, Science Source: Link
Friday, 17 November, 2017 - 15:39

Researchers from Washington University, St. Louis, USA surveyed Indian households to determine the ease of obtaining education and factors that hinder the process, in the country.

The United Nations Development Program which sets the sustainable development goals for a country has declared access to and quality of education as an important factor for sustainable development. Improving the quality of education means, providing equal opportunities for children from all economic classes and being inclusive of the disabled. India has adopted several measures since 2000 to meet some of these goals, yet problems of inclusiveness and support to complete a course for the differently abled, persists. Today, the country boasts of around 96% enrolment of children, between 6 and 14 years of age, from rural settings. Reservations for disabled persons, girls and other economically backward classes has also ensured equal opportunities. However, the challenge of providing quality education remains.

For their study, the researchers interviewed 1294 households in New Delhi. Of the 2559 individuals who were interviewed, the sample consisted of young and educated persons, with a greater proportion of Hindus, male heads of households, educated members of the household, and disabled persons. The households were asked about the different limitations they faced in functioning and performing activities as well as questions about access, retention and barriers to education, arising due to health problems.

The study points to the difficulties a disabled child goes through to obtain and retain the same services, that others don’t have to. The study showed that disabled students were far less likely to start school, and once enrolled, they were also most likely to dropout of schools, before completing their high school. The difficulties faced were found to be greater for girls, children from economically weaker classes, and children from households where the head of the household is uneducated. The researchers also stressed the need for more data to accurately assess learning outcomes and implication of early assessment, also suggesting for education to be looked at as a complex and dynamic phenomenon.

Section: General, Science, Society Source: Link
Thursday, 16 November, 2017 - 15:45

In a new study, scientists have found a revegetated coal mine to be an excellent site for long-term storage of carbon.

Coal mining was once the backbone of our energy requirements for the country. Even today, India is the fourth largest producer of coal and has the fifth largest coal reserves in the world. However, once coal has been extracted from a mine, the mines are usually discarded or converted into other industries or tourist attractions.

Scientists from Indian Institute of Technology, Dhanbad are now studying discarded surface coal mines, to determine the potential of using them as enormous carbon sinks, capable of storing large amounts of the greenhouse gas for a long period.

Carbon Sequestration is the process of storing carbon for long periods. Wetlands, forests, peat bogs are all excellent sources for carbon sequestration, storing millions of tons of carbon. For their new study, the scientists wanted to study the carbon sequestration potential and mine soil quality of revegetated carbon mines. They studied three types of sites—Young, intermediate and old, depending on how much time passed since revegetation of the mine. Soil quality was assessed by studying the accretion of soil organic carbon (SOC), available Nitrogen and Soil Carbon Dioxide Flux. They then compared the results obtained to a reference forest site.

The study revealed a threefold increase in SOC and a five-fold increase Nitrogen concentration, in a revegetated coal mine, after 14 years of revegetation, which was found to be equivalent to the reference site. Carbon sequestered by the sites between 2 to 14 years after revegetation also showed a significant increase, with above ground biomass accounting for the maximum share of sequestered carbon. The study also revealed an increase in carbon dioxide concentration with age.

The study revealed other details about the soil and vegetation in the place too. Soil respiration was found to be influenced by temperature more than the soil moisture content. The study also identified North Indian Rosewood (Dalbergia sissoo) and Katsagon (Heterophragma adenophyllum) species trees to be ideal for revegetation of such sites. The study gives us an excellent alternative to combat the effect of greenhouse gases, while recycling our discarded coal mines.

Section: General, Science, Ecology Source: Link
Wednesday, 15 November, 2017 - 15:41

On 26th of January 2001, India was gearing up to celebrate the country’s 51st Republic Day, when an event that lasted a little longer than 2 minutes, devastated the country. Kutch region in Gujarat was hit by a 7.7 magnitude earthquake. The death toll was estimated to be around 13,000, with wide scale devastation to property. The incident flattened many villages and destroyed many historic and heritage buildings.

The buildings of the region were found to be a mix of modern single and multistoried structures as well as traditional structures, and many of these structures weren’t designed to withstand severe quakes. Bhuj in Gujarat was one of the worst affected areas, with extensive damage caused to several buildings and structures in the region.   

Scientists from the Center for Earth Sciences at Indian Institute of Science set out to study the reason for the widespread destruction. Although effects like ground liquefaction and failure, where the soil gets saturated and loses its strength due to constant shaking generally caused by quakes, were noticed in many parts hit by the earthquake, these effects weren’t prominent in Bhuj. Yet, the devastation in the region was extensive, suggesting site response or the behavior of the site to the quakes, to be an important factor for the destruction.

The researchers applied a method called horizontal to vertical spectral ratio method to ambient vibrations (HVSR-AV) to examine if site response had any significant role in the observed damage. The scientist also considered the weathered sandstone exposed in the city to be a resonating layer, which could resonate with the vibrations caused by the quake.

The amount of data available does not allow the scientists to make a quantitative modelling, however, the results suggest that site effects, like ground liquefaction, weren’t important contributing factors to the destruction caused and other unknown factors could be the reason. More importantly, the study helped the scientists verify the efficacy of the HVSR-AV method in predicting the effects of a quake, especially in low-seismicity areas.

Section: General, Science Source: Link
Tuesday, 14 November, 2017 - 14:52

Humans have used nanoparticles since antiquity. Stone age workers, artists during the renaissance, and ancient metallurgists have all used nanoparticles either for decorations or to enhance the properties of materials.

Today, nanoparticles play an important role in many engineering and medical applications. Metal nanoparticles like gold, silver, zinc, platinum etc. have been used for coloring and strengthening materials, as catalysts in chemical reactions etc. Palladium is one such material commonly used to make metal nanoparticles. Palladium Nanoparticles (Pd NP) are increasingly being used as a catalyst in many oxidation and reduction reactions.

In a new study, scientists from Dibrugarh University, Dibrugarh and University of Aveiro, Portugal, with assistance from the Department of Biotechnology, India have developed a new biogenic method of synthesizing palladium nanoparticles. Using leaf extracts and starch, the scientists were able to synthesize highly dispersed Pd NPs.

The scientist collected fresh green leaves of Garcinia pedunculata, better known as Bar Thekera in Assamese, from Dergaon area in Assam. The leaves are chopped and turned into an aqueous solution which served as a bio-reductant, reducing Palladium acetate into palladium nanoparticles, while starch served as a bio-stabilizer, keeping the reactions stable. Once synthesized, the solution was viewed under spectrophotometer and a Transmission Electron Microscope to verify the presence of the Pd NPs.

On synthesizing the particles, the scientists then performed chemical reactions using the Pd NPs as a catalyst. They tested the effect of the nano particles in three situations or reactions – in Suzuki- Miyaura reaction, Selective oxidation of alcohols to corresponding carbonyl compounds and reducing toxic Chromium into a non-toxic form. The newly synthesized Pd nanoparticles were proven to be an effective catalyst in all three reactions. The scientists also found another remarkable property of the Pd NPS – the particles also exhibited anti-microbial and anti-biofilm properties. When exposed to a newly discovered multidrug resistant bacterial strain—Cronobacter sakazakii, the Pd NPs were found to prevent the growth of the bacteria suggesting uses in medical applications as well. The newly developed method can be considered as a ‘green way’ to synthesize Palladium nanoparticles.

Section: General, Science, Technology Source: Link
Monday, 13 November, 2017 - 12:21

The Red Panda (Ailurus fulgens) is an animal with soft reddish-brown fur, is only seen in the temperate forests of the Himalayas that includes parts of India, China, Nepal, Bhutan and Myanmar.

Unlike the popular misconception, the Red Panda is not closely related to the Giant Panda. In fact, the Red Panda is put in the Family Ailuridae, all to itself, and is more closely related to racoons, weasels and skunks.  But like the Giant Panda, this small mammal’s diet is also made up of mostly bamboo, although it may also eat smaller mammals, birds, flowers, fruits and berries.

But the Red Panda is facing a lot of threats today; from loss or fragmentation of its bamboo. Estimates put the current global population of Red Pandas at about 10,000 individuals and has been put under the ‘Endangered’ category of the International Union for the Conservation of Nature’s (IUCN) Red List

A group of researchers conducted a study on Red Pandas and the factors that affect its occurrence in the Dhorpatan Hunting Reserve in Nepal. 

The researchers hypothesised that a greater number of Red Pandas would be found in areas with less human interference, like livestock grazing and bamboo extraction, high number of Arundinaria sp. of bamboo, which makes up 81.7% of the Red Panda’s diet in this reserve, and higher amount of forest cover. Field surveys were then done to gain information about the occurrence of the mammal in this reserve.

Red Panda were indeed found in areas with higher amount of bamboo and decreased where bamboo extraction was high. The study also showed that the mammal preferred elevations below 4000m, as previously believed.

As local communities that live within the reserve depend on bamboo to feed their livestock and also to make baskets which are sold in local markets, conservation and managements plans for the Red Panda would have to take into account the interests of both the panda and the indigenous human communities suggest the researchers.

Section: General, Science, Ecology Source: Link

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