You are here

Science News

Kharagpur Wednesday, 25 April, 2018 - 08:00

In the past century, fossil fuels like petrol and diesel have powered our vehicles, machines and in fact, our world! But the era of these fuels is coming to an end; all our petroleum reserves are soon ending, and the increasing pollution due to these fuels is making the world sick. Now, our hope lies in biofuels—fuels produced by organic wastes that are renewable and eco-friendly, unlike fossil fuels. In a step that can make biofuels a reality, researchers at the India Institute of Technology Kharagpur are scripting a new roadmap for India's biofuel demands by exploring efficient ways to produce biohydrogen.

"Biofuels can be harnessed easily. It can also be used in existing combustion engines after blending with petroleum diesel to various degrees. No separate transportation infrastructures would be required for such fuels", says Prof. Debabrata Das, in his article in the journal INAE Letters. He also leads the Bioprocess Engineering Laboratory at IIT Kharagpur where researchers are developing expertise in the field of biohydrogen production.

Biohydrogen is the hydrogen produced from organic wastes. As a fuel, hydrogen has the highest energy density, yielding 143 kJ per gram. Compare that with diesel that yields about 48kJ per gram! It is also a clean fuel, emitting no poisonous gases when burnt, and is eco-friendly too. While natural hydrogen is abundant, it is easy to use the hydrogen produced by fermentation of organic wastes as fuel.

In their research, spanning over many years, the researchers have investigated different kinds of chemical processes, bacteria and the organic medium needed to produce the most amount of hydrogen. “The main objective of the research work is to improve the biohydrogen production process with the primary emphasis being to increase yields of hydrogen from the existing processes using organic wastes”, they say.

The centre-piece in the production of biohydrogen are the microorganisms that break up the carbohydrates in the organic wastes and produce hydrogen as a byproduct. In this study, the researchers investigated a wide range of potential hydrogen producing microorganisms, including those that tolerate a very high temperature (thermophiles) and those that grow best in moderate temperatures (mesophiles). They found that Klebsiella pneumoniae, a lactose producing bacteria, produces hydrogen at a higher rate than other mesophilic organisms. It works best at an optimum temperature of 36 °C and a pH of 6.5.

The researchers also studied various organic media which these microorganisms ferment to produce hydrogen. Algal biomass (organic waste rich in algae), deoiled cakes of groundnut, coconut and mustard, starchy wastewater, plant dry matter, cane molasses and cheese whey were some of the medium studied. Using mathematical models, they designed bioreactors, where the fermentation takes place. They studied the composition of the biomass and the breakdown products and measured the amount of hydrogen obtained from each medium.

The researchers have also investigated the potential of acidogenic bacteria—bacteria that produce fatty acids and acetic acid as byproducts—in the fermentation process without oxygen. They have also employed an innovative approach of ‘dark’ fermentation—fermentation in the absence of light—followed by the removal of carbon dioxide to harness only the hydrogen. This method yields the maximum production of hydrogen.

Funded by the Ministry of New and Renewable Energy (MNRE—India), Defence Research and Development Organisation (DRDO—India), and the Department of Biotechnology the researchers have developed customised bioreactors to produce hydrogen continuously for use in fuel cells and other applications. They have built a prototype with a 20-litre bioreactor that uses agricultural residues, and the live demonstration of the same can be seen here.

The researchers are now vying for large-scale hydrogen production for commercial applications. “Our endeavour with large-scale biohydrogen production has motivated us to commercialise biohydrogen production process for decentralised energy solution”, they say. So far, the bioreactor at the institute has been able to produce 76.2m3 of hydrogen using 10,000 litres of cane molasses supplemented with groundnut de-oiled cake at 34–37 °C.

With natural sources of energy like the fossil fuels unable to quench the world’s energy demands, biohydrogen holds hopes of clean, green and cheap energy for the future. “Hydrogen production using organic wastes/residues could become a promising way for economical and sustainable clean energy generation which also leads to waste management”, the researchers say.

Section: General, Science, Technology, News Source: Link
Indore Tuesday, 24 April, 2018 - 08:10

“The only thing that is constant is change”, said Heraclitus, the Greek philosopher. This adage is apt for organisations as they need to evolve with new and unique ideas to live in the present. Hence, many of them spend much of their revenues on research and innovation. While companies in the US and China spend around 60-70% of their earnings on research, private sector companies in India invest only about 20% as of 2016.

One way the companies recoup the spending on inventions is by obtaining a patent—a legal document that prevents others from using, making or selling their invention without permission—thus monopolising on it. However, in developing countries like India, the spending on research has always been low due to weak policies that protect the patents. Now, a new study by researchers at the Indian Institute of Technology Indore, India; University of North Texas, USA and the National Institute of Technology Goa, has shown that the changes made to patent policies in 2005 have boosted research and development in India.

Patent laws in India have existed as far back as the 19th century. One of the most pivotal changes in came in 2005, when India decided to comply with the Trade-Related Aspects of Intellectual Property Rights or the TRIPS agreement. TRIPS is an international legal agreement between member nations of the World Trade Organization that sets down minimum standards for the regulation of intellectual property. Complying with TRIPS brought India’s patent policy close to the international norms through several changes like increasing the patent duration to 20 years and allowing patents on food and pharmaceutical products.

The researchers of this study looked at the impact of changes to the existing patent policies on the intensity of research and development from 1989 to 2010. “For some changes in the patent policy, we have found positive impact”, remarks Dr. Ruchi Sharma, the lead author of the study, in an interview to Research Matters. The study was published in The Journal of World Intellectual Property and was funded by the Indian Council of Social Science Research.

The results of the study show that the spending on research and development in the private sector in India has been increasing since 1989. In the period between 1989 and 1990, the research and development expenditure was close to 0.06% of the total sales of these companies. This number jumped to around 0.40% during 2004-2005 when Indian patent policies complied with TRIPS and gradually increased to 0.48% in 2007-2008.

To ascertain that the significant increase is due to changes in the patent policies, the researchers looked at other factors that promote innovation like the increase in exports, technological improvements, and changes in tariff rates and economic policies. They found that each of these factors did play a role in influencing the spending on research. However, on investigating the aspects of the patent policy itself, they found that the increase in patent protection duration to 20 years, better enforcement mechanisms and complying with international norms significantly impacted the spending on research. Industries involved in the manufacture of chemical products, botanical products, communication equipment, pharmaceuticals, etc. recorded a notably greater spending on research.

While the findings are good news for a country like India that has enormous innovation potential, the researchers opine that changes in the patent policies  is just one step in the right direction. “Having made changes in the patent policy as per TRIPS, there is no immediate need to strengthen the laws further”, says Dr. Sharma. However, allowing industries to access better technology and promoting exports could further increase research spending and innovation, the researchers suggest.

Section: General, Science, Policy, Deep-dive Source:
Dhanbad Monday, 23 April, 2018 - 16:34

Scientist from Indian Institute of Technology (India School of Mines), Dhanbad, Jharkhand are studying the potential environmental risks and hazards of coal ash, by studying the composition of the by product.

India is largely dependent on coal power, which provides for more than 62% of the country’s electrical supply needs. The country also hosts vast coal reserves, in West Bengal, Madhya Pradesh, Bihar etc, and little to no oil reserves. This makes coal the most important source of energy for the country. Coal is often used in thermal power plants, where heat from burning coal is used to produce steam from water, which in turn generates electricity.

The coal is often burned in large furnaces, giving rise to two types of by-products; fly ash and bottom ash—together called coal ash. The bottom ash gets collected at the bottom of the furnace, while the lighter fly ash, which gets blown upward, is collected by precipitators or filters. The components of t fly ash depends on the coal mineral that was used, but usually contains large amounts of Silicon dioxide (SiO2), aluminium oxide (Al2O3) and Calcium Oxide (CaO), with trace concentrations of other elements, like arsenic, mercury, lead, cobalt, manganese etc.

For their study, the researchers wanted to study the potential environmental risk posed by the coal ash emitted from thermal power plants (TPP) in India. Five TPPs in the country were chosen for the study. The researchers performed a physical, chemical and mineralogical characterization of the fly ash that was collected from the five TPPs. Further analysis of the fly ash and bottom ash was also performed to identify the trace elements present.

Their results showed that the fly ash was primarily enriched with Silicon dioxide (SiO2), aluminium oxide (Al2O3), Iron Oxide (Fe2O3) and small concentrations of Calcium Oxide (CaO) and magnesium oxide (MgO). While, minerals like quartz, mullite, hematite, and magnetite were also observed. Trace concentration of elements like Chromium, Lead, Mercury and Arsenic were also present in the fly ash, in varying concentrations.

Next, the researchers studied the environmental risk posed by the various elements and minerals by conducting geoaccumulation index (I geo) and potential ecological risk index (PERI) studies. The results show that while one of the five TPPs studies posed a moderate risk, the four other TPPs were considered as low risk. The study shows that, while coal burning may still contribute towards a warming planet, the immediate implications due to pollutants being released into the atmosphere from the fly ash can be neglected.

Section: General, Science, Society, News Source: Link
Netherlands Monday, 23 April, 2018 - 08:09

India, the land of diversity, is bestowed with several cultures. The vast number of languages spoken here is a testimonial to that fact. While learning these languages is exciting, studying them is fascinating for another reason—they help us understand the little-known history of the Dravidians, who lived in the subcontinent before the speakers of Indo-Aryan languages arrived around 1500 BC. So far, not much is known about their origin and their dispersal across the country. Now, a study by a group of researchers from the Max Planck Institute for Psycholinguistics, the Netherlands, has tried to reconstruct the Dravidian language family tree in an attempt to understand Dravidian history. The results show that these languages are as old as 4500 years! So what does that mean?

The Dravidian language family is one of the world's primary language families. It has 80 varieties, spoken by over 200 million people in south, central and north India. Interestingly, the Kurukh language of Nepal and the Brahui language of Pakistan and Afghanistan belong to the Dravidian family. Certain languages of the Dravidian language family are known to have been written for over 2000 years, and influenced Vedic Sanskrit and modern Indo-Aryan languages, thus playing a significant role in contact between Indo-European and Austroasiatic language families.

Previous linguistic studies have tried to understand the relationship between various Dravidian language subgroups and have recognised four main branches of the language family. The South Dravidian I subgroup consists of Tamil, Malayalam, Irula, Kodava, Kurumba, Kota, Toda, Badaga, Kannada, Koraga and Tulu, among others. The South Dravidian II subgroup has Telugu, Gondi and Kuvi, and others. The Central Dravidian subgroup comprises Gadaba, Parji and Kolami, and the North Dravidian subgroup has Brahui, Kurukh and Malto languages.

An interesting fact about the Dravidian family of languages is that there many smaller, spoken ones, which are not well-studied. The researchers of this study, published in the journal Royal Society Open Science, focused on a representative sample of languages to reconstruct the Dravidian language family tree by using first-hand data.

“We collected 100 items of basic vocabulary from native speakers of a diverse sample of Dravidian languages”, says Dr. Annemarie Verkerk, an author of the study. They used the Swadesh list, a compilation of primary vocabulary that can help in assessing the relationship between existing languages alongside the changes over time, devised by the linguist Morris Swadesh.

While previous studies on the Dravidian family of languages have used datasets derived from dictionaries, this study combined data collected first-hand with advanced statistical analysis. “Swadesh’s 100-concept elicitation list was used to collect lexical data for 20 languages. Responses were recorded and written down if this was possible. For some spoken languages, informants did not want to write down responses in non-native scripts. Recordings and written transcripts were transcribed to the International Phonetic Alphabet (IPA). Cognate (relatedness) coding of the responses was performed using the Dravidian Etymological Dictionary”, explains Dr. Verkerk, talking about the methods used in the study.

Map of the Dravidian languages in India, Pakistan, Afghanistan and Nepal adapted from Ethnologue (Source:rsos.royalsocietypublishing.org R. Soc. open sci. 5: 171504)

The researchers used a Bayesian phylogenetic inference method, a probability-based statistical approach that estimates the evolutionary history and relationships of a set of species or languages based on some prior data. Commonly used in ecology, this approach deduced a set of highly probable language trees, rather than a single ‘best’ language tree.

The findings are then compared to a commonly used reference tree namely Krishnamurti’s family tree, which classifies the languages into three main groups—South I and South II, Central and North. B. Krishnamurti, a linguist, is one of the most prominent figures in the study of the Dravidian languages as he applied modern comparative linguistic theory to study the diverse Dravidian languages and their relationships. The results of his work are used as a reference in further studies on Dravidian languages.

However, the researchers of this study found that there is a significant split between South I and the three other groups, which is estimated to have happened 2500-3000 years ago, a little latter than the expansion of the Southern Neolithic civilisation between 4000 and 3000 years ago. The agricultural practices in this period provide external evidence through crop vocabulary for the findings of this study.

The researchers incorporated historical and linguistic data, mostly evidence on when the written Dravidian languages are first attested in inscriptions, in the language tree to estimate the age of the Dravidian language family. Using these data, they found that the Dravidian language tree to be approximately 4500 years old, coinciding with the archaeological findings regarding the Southern Neolithic, a definitive period on the archaeological timescale. The Neolithic period in South India which lasted from 5000 years ago to 3400 years ago, is characterised by man-made artefacts like the ash mounds produced by early agricultural communities.

A NeighborNet visualization of differences relating to the vocabulary of languages. Colour-coding gives subgroup affiliation: red, South I; blue, Central; purple, North; yellow, South II. (Source: rsos.royalsocietypublishing.org R. Soc. open sci. 5: 171504)

While the analysis is informative about when the Dravidian languages originated and when they diversified, it does not tell us much about where this may have happened.

“The current analysis is an investigation of the genealogy of languages. It does not incorporate information about the current geographical information of languages, nor does it reconstruct where ancestors of the Dravidian languages were spoken in the past. However, this is possible, and this has been done for other language families”, says Dr. Verkerk.

The use of a Bayesian phylogenetic technique for linguistics makes the current study an interesting one. “The methods employed in this study have been started to be used in linguistics from 2000 onwards. They have been met with scepticism by historical linguists, who invented the 'standard' way to study the history of language, the so-called comparative method. The comparative approach makes a feature-by-feature comparison of two or more languages with common descent from a shared ancestor, to extrapolate and infer the properties of the ancestor. However, phylogenetic techniques for linguists build on the comparative method and are gaining more acceptance now”, explains Dr. Verkerk.

The study is one of the few based on the best-supported analysis that provides the current best estimate of Dravidian descent, throwing light onto the movement of ancient populations into and through South Asia. It shows that dating languages is one of the critical steps in understanding the history of Eurasia.

Section: General, Science, Society, Deep-dive Source:
Bengaluru Sunday, 22 April, 2018 - 08:59
Section: General, Science, Ecology, Society, News, Infographics Source:
Bengaluru Saturday, 21 April, 2018 - 08:12

Neutrinos are the elusive sub-atomic particles in the Universe. They are abundant throughout the universe and tens of thousands pass through our body every second!

'Neutrino' which literally means 'little neutral one' has neither mass nor charge, and it travels almost at the speed of light. They interact by weak-nuclear force, a force acting in the short range. They barely interact with matter. It is estimated that a whopping one light year thick block of lead is needed to stop a neutrino! That's one half trillion kilometers!

So how do we detect them? Predicted by Wolfgang Pauli in 1931, neutrinos were discovered in 1959. In the recent times, physicists are coming up with ingenious ways to detect them. Neutrino telescopes like Super-Kamiokande in Japan and IceCube in the South Pole are built to detect and observe these tiny elusive particles.

Scientists theorize that neutrinos were formed even before atoms during the Big Bang. They're commonplace in all nuclear reactions, like the ones that power our cities or the stars in sky! Since neutrinos do not interact with matter, unlike light, a sudden burst of neutrino can signal  a supernova (death of a star). These neutrino bursts act as an early warning for astronomers helping them prepare before the light from the supernova reaches the earth!

More neutrino research will demystify many objects and phenomena in the Universe including the gamma rays, black holes and dark matter.

Section: General, Science, Policy, Scitoons, SciQs Source:
Bengaluru Friday, 20 April, 2018 - 07:59

In this series, we detail on how ‘abused’ antibiotics are helping superbugs and why we tend to so

“We are giving antibiotics to more than 75% of patients. Even for the common cold, we prescribe two tablets of Septran [co-trimoxazole]”

This is not a confession of a doctor or a surgeon, but of a self-taught rural pharmacist! While his intentions to cure the ill may be good, does he/she know what that translates to? Turns out, THEY HAVE NO IDEA!

The discovery of antibiotics, their ubiquitousness, and the ease of accessibility has transformed healthcare. Fatal diseases like pneumonia and typhoid can now be cured, and surgeries can be performed without any risk of infections. And the epicenter of this transformation was the healthcare sector. Pharmaceutical industries became the producers of these magic pills called antibiotics and doctors – armed with their knowledge and expertise – became their guardians, and pharmacists the helpers. We, the people, owing to our trust in the healthcare system, became the proud consumers.

But, over the years, the roles have mixed up, and that has worked in favor of superbugs. Superbugs are certain bacteria that have defied antibiotics, developed resistance to them and are now threatening our existence. Now, we have superbugs resistant to tuberculosis, influenza and a host of other diseases. The problem is so severe that the World Health Organization has put out a  list of superbugs, urging researchers to come up with better antibiotics against these malefactors.

“Not getting the right drugs for the right duration is one of the leading causes of Anti-microbial resistance (AMR)”, says Prof. Joy Sarojini Michael of the Christian Medical College (CMC), Vellore. “This mainly happens due to the wrong prescription by doctors/quacks as a result of their lack of knowledge”, she adds.

If the prescription by doctors is questionable, can we really trust the prescription by a pharmacist? Or self-medication?

Antibiotics caught in the game of perceptions

The fact that pharmacists are turning into doctors and prescribing antibiotics for health issues like the common cold, are concerning for many reasons. Firstly, they are not entitled to prescribe antibiotics, or for that matter, any drug! Secondly, antibiotics do not cure a common cold, since it is caused by a virus, and should be treated by antivirals, not antibiotics. Thirdly, they may have no clue about the medical history of the infected person and might prescribe an antibiotic that might be allergic. If so, then why do people approach pharmacists for drug-prescription in the first place?

Perceptions of people in the healthcare sector-- doctors, patients, pharmacists -- form the driving force behind the rise of superbugs in India.

In a study, researchers at CMC Vellore studied the perceptions of people, pharmacists and doctors in the Vellore region to better understand the causes behind the misuse of antibiotics. It was a group discussion based qualitative study conducted in 2013. The researchers found that people’s financial status and accessibility to doctors were major determinants of people visiting doctors. “To see a doctor, we take leave from work and stand in a queue. Finally, the doctor will prescribe, possibly the same drug as the pharmacist. So, we go to pharmacy shop instead to get it quicker”, remarked one of the participants in the discussion who hailed from Vellore.

There is no cheer in the rural areas of the country either. With healthcare services already in the dismal state, people opt to take self-medication. “For dysentery, we have separate native treatment. Allopathic medicines have side effects”, they perceive, as told by one who participated in the survey. When enquired about the knowledge of antibiotics and antibiotics resistance, most people knew which antibiotics cured which symptoms, but had little idea of what antibiotics resistance meant.

If you thought the pharmacists and doctors, who are well aware of the repercussions of misuse/overuse of antibiotics, were any responsible, you could not be farther from the truth!  In the study, one doctor is said to have admitted, “If we ask for investigations on the first day, the patient never turns up again! So, instead, we immediately give antibiotics and watch for two days. Nobody bothers about diagnosis, only symptom relief.”

The pharma companies are compliant in this ploy too. “Reputed pharma companies offer complementaries for prescribing their drugs. If you prescribe more, they offer air-conditioned car or free tickets... Of late, we are forced to try new antibiotics”, confessed another doctor.

The pharmacists have a different motivation to sell antibiotics without prescription, to prescribe antibiotics, or to even change prescriptions. One pharmacist, interviewed for the study, confessed – “Nobody likes to lose business. We give whatever the customers ask. Competition, the location of shops, license issues...everything has become commercialized.”

Though there are different perceptions about the use of antibiotics, there is one overarching commonality – the antibiotics prescription depends more on sociological factors like quick recovery, patient satisfaction, and commercial incentives rather than biological factors like proper diagnosis and cure.

Added to this is the fact that the Indian market offers more than 10,000 antibiotics formulations; while the National List of Essential Medicines – containing medicines that satisfy the priority healthcare needs of the majority of the population – contains only 21 antibiotics and two antibiotics combinations. This disparity itself points to a vast misuse of antibiotics.

“We need to be proactive. Already we are behind and the bacteria are developing new ways of surviving”, cautions Prof. Sujith J. Chandy, the lead author of the above-mentioned study and a professor at CMC Vellore. “The problem is that AMR is a multifactorial problem and therefore the solution is complex, and interventions have to be at all levels and including all stakeholders. Some of the factors are difficult to change, but some are slightly easier. For our part, we need to promote health education, hygiene practices, and antibiotic use by using them in the right dose, right duration, right frequency”, he adds.

Until scientists develop better alternatives to current antibiotics, and the government strengthens regulation on its usage, the best we can do is to advocate the judicious use of antibiotics – the right dose, the right duration, and the right frequency go a long way to keep these superbugs at bay. After all, as responsible citizens, we also have a responsibility towards our country, don’t we?
 

Section: General, Science, Health, Deep-dive, Featured Source:
Bengaluru Thursday, 19 April, 2018 - 17:50

In a step that could ease some tension about India's Neutrino Observatory, the Indian National Science Academy (INSA), the National Academy of Sciences (NAS) and Indian Academy of Sciences (IAS) have issued a joint statement supporting the India-based neutrino observatory to be set up in Bodi West Hills in Theni district of Tamil Nadu.

The India-based Neutrino Observatory (INO) is a multi-institutional collaboration to build a world-class underground laboratory to study high energy and nuclear physics. The primary goal of the laboratory is to study neutrinos—fundamental particles with almost no mass that are produced either by radioactivity in the atmosphere, or by the Sun, or by high energy particles coming from space. The laboratory will consist of a large cavern longer but narrower than an average football pitch, and several smaller caverns. These are accessed by a 2100 m long and 7.5 m wide tunnel. The laboratory will also house one of the world’s most massive magnetised iron plates weighing a whopping 50,000 tons!

However, the rosy dream of INO being a full-fledged, underground science laboratory for studies in physics, biology, geology and hydrology has run into obstacles since its inception in 2002. The project faced initial setbacks when the first chosen location in Singara near Nilgiri Hills, Tamil Nadu faced immense protest from environmental groups, due to a perceived threat to Mudumalai Tiger Reserve. It was then shifted to Bodi West Hills in Theni, where the project again raised many environmental concerns, again due to its proximity to Mathikettan Shola National Park in Kerala. In a whiff of relief, the Ministry of Environment, Forest and Climate Change, Government of India, finally provided the clearance for the project to go ahead as a special case, after obtaining the necessary permissions from the State Pollution Control Board and forest clearances, on 26th March 2018.

The INO project is of the nation's largest scientific project yet, where nearly 100 scientists, from 25 research institutes and universities across the country, would be collaborating to create new waves in particle physics with their research. In their statement, the three premier academies also highlighted the same, affirming their support to INO. “The Science Academies of India are strongly supportive of the establishment of such an experimental facility for its intrinsic scientific value”, reads the statement.

The statement also appealed to the nation to support the collaborative effort—“The science academies hereby appeal to people of the district, state, and country to support this educational and research project wholeheartedly. A successful INO experiment will be a major technological and scientific national achievement.”

Section: General, Science, News Source: Link
Bengaluru Thursday, 19 April, 2018 - 14:27

A new study by scientists from Indian Institute of Science (IISc) has shown that hues of different colours generate large gamma oscillation in the primary visual cortex, the region of the brain that processes visual information. Reddish hues were seen to cause the strongest oscillations.

While monitoring the electrical activity of a brain, gamma oscillations or oscillation of neurons at frequency range around 30 to 80 hertz, are known to be a prominent signature of sensory stimulation, like seeing, touching and hearing. These oscillations are influenced by the properties of the stimulus and behavioural state. Gamma oscillations also play a purported role in natural vision, evidence for which is still lacking, and in cognitive functions, like paying attention.

Although gamma oscillations generated by the visual senses have been studied before, these studies were conducted using light from an achromatic (colourless) lens. In their new study, the scientists wanted to understand the response of the gamma oscillations, when different colours are presented in the field of view.

Tests conducted on monkeys have shown a dependence of the gamma oscillations to properties of the colour, like hue and saturation. Three adult female monkeys were shown flashing colours of different hue, saturation and luminance, while the gamma oscillations were recorded using probes implanted surgically.

“We show that gamma oscillations of extremely high magnitude (peak increase of ∼300-fold in some cases), far exceeding the gamma generated by optimally tuned achromatic gratings, are induced… by full-field color stimuli of different hues” say the authors about the result of the study.

They also noted that the gamma oscillations the strongest oscillations were recorded for long-wavelengths or reddish hues. The oscillations depended by the purity of the hue and increased with hue saturation. Interestingly, the luminance, or the intensity or brightness of the light did not appear to influence the oscillations. They also noted a strong correlation between L and M cone cell (types of photoreceptor cells in the eye) contrast produced by the stimuli. This, the author suggest gamma oscillations could be a marker of the specific mechanisms underlying this L-M cone contrast.

“These findings provide insights into the generation of gamma oscillations, as well as the processing of color along the visual pathway” say the authors about the importance of their work.
 

Section: General, Science, News Source: Link
Mumbai Thursday, 19 April, 2018 - 07:54

India is infamously called the ‘diabetes capital of the world’. With over 40 million diabetics in the country, we have a distinction of having the highest number of diabetics for any country. This has huge implications on the country’s healthcare, forcing doctors, scientists and citizens to work together to manage and remediate this condition. Now, researchers at the Indian Institute of Technology Bombay (IIT Bombay) have some sweet news for diabetics. They have developed a polymer based bioartificial pancreas that can be implanted inside the body, thus helping in managing diabetes.

Diabetes mellitus is a chronic metabolic disorder in which sugar levels in the blood are very high for a prolonged period. In a healthy person, the body breaks up the carbohydrates in the food, into glucose, which supplies energy. This is done with the help of a hormone called insulin, produced in the pancreas. However, in a diabetic, the body either does not make enough insulin (Type 1 diabetes), or cannot use the insulin it produces (Type 2 diabetes). In some cases, it could be a combination of both.

To treat Type 1 diabetes, a condition affecting three out of 100,000 children of 0–14 years, doctors recommend the use of insulin injections, insulin pumps, or transplantation of either the whole pancreas or islet cells — part of the pancreas that produces insulin. Recently, there has been considerable progress in developing bioartificial pancreas with islet cells which mimic the function of a natural pancreas. However, a persistent roadblock has been the issue of biocompatibility — the body treats the bioartificial pancreas as a ‘foreign’ object, triggering the immune system’s response, which can degrade the function of the artificial pancreas.

In this study, the researchers have developed a bioartificial pancreas using polymer based hollow fibre membrane that is biocompatible and can also grow and sustain insulin producing cells on it. “A hollow fibre membrane is a narrow tube about 1 mm in diameter with pores in the wall ”, explains Prof. Jayesh Bellare from IIT Bombay, who led the study. “When liquid is passed through the tube (also called lumen), the wall selectively retains certain constituents and allows others to pass through”, he says, adding that this sort of ‘selective separation’ is used in many processes, including dialysis.

The researchers made these patented hollow fibre membranes using a polymer called polysulfone, which is known for its toughness and stability, with an additive compound called TPGS (d-α-Tocopheryl polyethylene glycol 1000 succinate). “The advantage of our hollow fibre membrane is that it supports the cells to grow by mimicking the extracellular matrix in which the cells naturally grow, and simultaneously, allows insulin to reach the patient while preventing an immune reaction from cells if they are of foreign origin”, remarks Prof. Bellare.

The inner side of the hollow fibre membranes developed by the researchers has pores in the nanometer range and is responsible for the selective separation of insulin. The rest of the membrane is more porous and has bigger pores which provide support.  The researchers made the bio-artificial pancreas by placing together one or more hollow fibres to form a small bioreactor — a container-like structure where insulin is produced.

The researchers have tested their device with both human stem cells derived from umbilical cord, as well as islet cells from pig pancreas. “For the first time ever, we have successfully encapsulated human stem cells and porcine cells in our novel and patented material derived hollow fibre membrane”, says Prof. Bellare. The researchers then implanted these devices into diabetic mice for 30 days and found that these implants caused no abnormalities to other organs. In addition, the immune cells of the mice did not attack the implants, and blood vessels were also seen growing on the cells of the implants.

The research could improve the quality of life for more than 542,000 children in the world living with Type 1 diabetes. So how far are we from seeing this bioartificial pancreas in action? “Although there is a long way to go for making islet transplantation a cure for diabetes, but with the right material and cell type, this can become a reality”, says Prof. Bellare. As a next step, the researchers plan to continue studying the how the new device behaves in large animals. “Much more will be needed to bring this in human trial; the basic technology has been demonstrated in our work”, he concludes.

Section: General, Science, Technology, Health, Deep-dive Source:

Pages