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Thiruvananthapuram Tuesday, 23 January, 2018 - 12:43

Scientists from Indian Institute of Space Science and Technology (IIST), Thiruvananthapuram have possibly designed the first sustainable molecular keypad lock, which can also be used as a sensor of a poisonous pesticide.

With connectivity and networking becoming increasingly ubiquitous, the need for secure locks and security measures have also increased. From the keypad locks on our smartphones, and the multi-character passwords used for banking and other websites, to the biometric passwords like fingerprints and iris scanners, today, passwords are everywhere. To keep pace with the hackers and digital criminals, all the while keeping the system small enough to fit on a smartphone, security locks have been ever evolving. One of the latest advancement in this area is the rise of molecular locks- where password are stored at a molecular level, making the system extremely small, while providing excellent measures for security too.

A conventional keypad lock, like the one on our smartphone and computer, uses electronic signals to verify the legitimacy of the password being typed in. A molecular keypad lock, on the other hand, stores the password information at a molecular level. To unlock, a particular sequence of chemical input is required. The different password combinations are stored using a combination of two or more chemicals. Often an input signal triggers fluorescent chemicals in a particular order, and if this order matches the password, the authentication becomes successful.

In their new study, the scientists from IIST used chemicals obtained from bioresources to make their molecular keypad lock. Using azobenzene derived from cardanol, a type of lipid obtained from cashew nutshell, and quantum dots derived from honey, makes the new system the first completely sustainable molecular keypad lock.

Apart from a keypad lock, the scientists also demonstrated other uses for the same system, like an IMPLICATION logic gate and an pesticide sensor, using the same system. An IMPLICATION logic gate is a type of logical operation, where the relationship between two statements holds true when one logically follows from the other. The molecular was also designed into a fluorescent probe for detection of Carbofuran, one of the most toxic pesticides in use. This makes the new device a true multipurpose tool.

“This is the first example of molecular keypad lock constructed from sustainable components and thus opens a new pathway in the field of Sustainable Molecular Electronics” claim the researchers.

Section: General, Science, Technology, News Source: Link
Bengaluru Tuesday, 23 January, 2018 - 07:50

Study investigates how successful Primary Healthcare Centres are, in tackling diabetes and hypertension.

Non-communicable diseases -- diseases that do not spread from one person to another -- like diabetes, hypertension, Parkinson’s etc., are a major public health challenge today. In India, almost one in three have hypertension (increased blood pressure) and about 8% are diabetic. A way to address this growing epidemic is to build a strong healthcare system, supported by the government, where medicines to such diseases are accessible and affordable for all. The primary health centres (PHCs) are established for the same reason. But how effective are they? A new study funded by the World Health Organisation (WHO) examines this.

“India has launched a national programme to address several non-communicable diseases, including diabetes and hypertension, in 2010. It stresses the need for a comprehensive management strategy for such diseases, including risk reduction for prevention, early diagnosis, appropriate management and specific intervention strategies for different levels of health services”, informs Dr Prashanth N S, Head of Health Equity and Evaluation team at the Institute of Public Health, Bangalore, and the lead researcher of the study.

This study, published in the journal BMJ Global Health, found many loopholes in the healthcare delivery system to combat diabetes and hypertension, in Tumkur district of Karnataka, where the study was conducted. “We chose for diabetes and hypertension because these conditions are considered low hanging fruits among non-communicable diseases; one expects that care for diabetes and hypertension is fairly universal and available at primary care levels”, says Dr. Prashanth about the choice of the diseases for the study.

The researchers selected a random sample of 1157 diabetic and/or hypertension patients, conducted a household survey, and interviewed them. They also held focussed group discussions with patients, health workers, PHC medical officers and pharmacists to understand and assess the preparedness of local health system in PHCs for addressing diabetes and hypertension.

The results revealed that less than 10% of the survey respondents got their medicines from the PHCs and 76% of them brought their medicines from private pharmacy. Although healthcare costs in a private hospital was expensive, the respondents felt that it was of a better quality. They also believed that care in PHCs was inconsistent, and required multiple visits which hurt their pockets. In addition, they preferred to go to private care also because medicines at PHCs were either unavailable or of poor quality. Nearly a third of the PHCs investigated didn’t have a doctor, pharmacist or a functional laboratory, which further accentuated the dependence on private care. Also, some of the PHCs were running out of stock of medicines for nearly 6 months!

The study also found that at a governance level, diseases like diabetes and hypertension did not appear to be among the top priorities for medical officers or health managers. Their focus was usually on mother and child care and communicable diseases. In addition, the allocation of financial and managerial resources for non-communicable diseases in general, and for diabetes and hypertension in particular, was relatively low. “The allocation of resources or activities to address non-communicable diseases at the primary healthcare level in villages is minimal, whereas the focus remains on identifying activities for the care and prevention of such diseases at the taluka and district level”, says Dr Prashanth.

To add to this, the doctors at PHCs were found to refer private care to some patients, and prescribed combination medicines -- drugs containing two or more compounds like Imol plus that contains paracetamol to reduce body temperature, ibuprofen that acts as a painkiller, and caffeine to induce sleep. Also, rampant corruption and demand for informal payment further pushed patients towards private healthcare. “Diabetes and hypertension are perceived as serious diseases, and the villagers chose to go to private sector. However, they would still receive care for non-threatening conditions like vaccinations and child care at the local PHCs”, remarks Dr Prashanth, about the findings of the study.

Health systems in low and middle-income countries are struggling to organise and manage care for diabetes and hypertension within their public health systems. Like the study found, gaps in infrastructure, human resource availability, performance and governance of local health systems were stumbling blocks in delivering good quality healthcare against non-communicable diseases. “The non-communicable disease program plan clearly mentions services for these diseases at PHC, but our study has found out otherwise”, says Dr. Prashanth.

The study highlights the urgent need for local health system planners and managers to prioritise care for diabetes and hypertension by investing in infrastructure, in improving the availability and performance of human resources, as well as in improving the credibility of government primary healthcare systems. “Our study has shown that patients, especially the poor, have to depend on expensive care in private facilities for simple and essential medicines and treatment for diabetes and hypertension in Tumkur, and possibly in several other rural areas in the state. The findings need urgent attention from the state government in ensuring basic treatment and follow-up for non-communicable diseases in government primary health centres”, signs off Dr. Prashanth. 

Section: General, Science, Health, Society, Deep-dive Source:
Vadodara Monday, 22 January, 2018 - 16:05

The Young Ecologists Talk and Interact (YETI) conference is underway at the Maharaja Saiyajirao University in Vadodara—commonly referred to as the cultural capital of Gujarat. The four-day conference, commencing on the 22nd of January and concluding on the 25th of January, 2018, gives early career ecologists an opportunity to interact with like-minded students from across the country to exchange ideas and collaborate.

In 2008, the need for networking and shared learning among the young ecologists in Bengaluru led to the creation of Students Meet in Ecology, Evolution, and Conservation Science (SMEECS). In 2009, the need for such a space through the country led to SMEECS being rechristened as YETI, and students from all over the country were invited to join the newly created online forum. Today, YETI provides an ideal platform for students, researchers, citizen scientists and hobbyists from across the country to discuss important issues related to conservation, nature and ecology.

The YETI is a first of its kind conference in India that is entirely organized by student volunteers for the students of ecology from all over the country. This year’s conference will boast of a range of activities to facilitate discussion among students, these include web seminars, poster presentations, panel discussions, workshop and plenary talks. The event includes both long and short workshops, conducted by leading experts in the field. The long workshops lasting around 3 hours long or more covers a range from topics like “The web of design: Untangling complexities of research design for ecological studies” conducted by Dr. Upamanyu Hore & Dr. Sabysachi Dasgupta, and “Crafting a story from a scientific study” conducted by Sandhya Sekar. While the short workshops will also be held on varied topics like “Writing Grants in Ecological Sciences” conducted by Dr. Sabuj Bhattacharyya, Ms. Monica Kaushik and “Scripts for data acquisition with paper-based surveys” conducted by Nishadh.K A & Powsiya H.

The students at the conference will benefit from interaction with researchers, scientists, science communicators and peers working in the field of ecology, helping them understand the work that different institutions are carrying out around the country. While students with interests outside academia will have an opportunity of interacting with people varied walks of life, this list includes but is not limited to Sofia Ashraf, Indian rapper, who has over 4 million views on YouTube for her song “Kodaikanal wont” and Saurabh Sawant, wildlife photographer.

This year marks the 10th edition of the conference. Apart from the annual conference, students interested in ecology can also access the YETI mailing list which provides periodical updates on internship, job and research opportunities in the field of ecology.

Section: General, Science, Ecology, Events Source: Link
Kerala Monday, 22 January, 2018 - 07:55

The rise of antibiotic resistance in bacteria is an alarming threat to the world today. Numerous diseases like tuberculosis, pneumonia and typhoid which could have been once controlled with antibiotic doses, are now untamable. Thanks to our indiscriminate use of antibiotics, these pathogens have now evolved genes that can make them immune to most drugs. Mastitis, an infection in the udder of cows, is one such bacterial disease and is one of the most prevalent diseases affecting dairy herds worldwide. Staphylococcus aureus and its strains are among the pathogens that cause subclinical mastitis,  invade the udders of lactating cattle, and get into humans through the milk we drink. Like its peers, now Staphylococcus is increasingly becoming resistant to antibiotics.

India is the world’s largest producer of milk. So how prevalent is mastitis among Indian cattle and what implications will it have on a nation that is so dependent on the dairy industry? In a recent study published in the journal PLOS One, scientists from the Department of Veterinary Epidemiology and Preventive Medicine, College of Veterinary and Animal Sciences, Kerala, have explored this. They have published the first ever report of persistent mastitis infection caused by drug resistant Staphylococci, with virulence factor Panton-Valentine Leukocidin (PVL), from dairy cattle in India. The presence of PVL gene is associated with the increased ability of S. aureus to cause infections.

“Staphylococci are capable of persisting in the bovine udder for years together, and they get excreted through the milk throughout this period. Once established, these bacteria will remain in the udder during the dry period (when the cow is not lactating), while other bacteria may not”, says Dr. Kulangara, from the College of Veterinary and Animal Sciences, who is also a co-author of this study.

As with other bacterial infections, dairy farmers resort to antibiotics as the first line of defence. But does that work? “Intensive antibiotic therapy attempted by western countries could bring recovery in about 52% of animals. This has also prompted Scandinavian countries to restrict the treatment and instead enforce culling and removal of cows with Staphylococcal mastitis”, says Dr. Kulangara.

The problem lies in the indiscriminate use of these antibiotics, which have already given rise to Staphylococci strains resistant to β-lactam group of antibiotics. “We don’t need to use such advanced antibiotics to treat all mastitis cases in cows”, says Dr. Kulangara, adding that countries like the USA have already recognized antibiotic resistant Staphylococcus aureus as a more serious threat than AIDS.

“Early and correct use of basic antibiotics can bring about recovery in a very high percentage of cows with mastitis, and the remaining will definitely respond to second level antibiotics. Very few may need third level antibiotics and even fewer will not respond at all. What actually happens in the field is that the vet simply goes for level three antibiotics as a first choice to assure recovery. This will surely promote development of antibiotic resistant bacteria capable of posing serious threat to the public health”, remarks Dr. Kulangara, talking about the gravity of the problem.

In this study, the scientists isolated Staphylococci from dry bovine udder and tested them for the presence of antibiotic resistant genes such as mecA, mecC, blaZ and against common antibiotics like tetracycline, cefoperazone, methicillin, oxacillin and cefoxitin, and the virulence gene PVL. “For this study, the secretions from dry udder were collected so as to define the true persistent infections, from the contamination during milking and transient infections of the udder”, says Dr Kulangara. Apart from finding these resistant genes, they also found, for the first time in India, a high level of Staphylococci resistance to the antibiotic azithromycin (27.8%).

Fortunately, Staphylococci cannot survive pasteurization. But, in a country like ours where many communities lack basic infrastructure, there are many who still consume unpasteurized milk. “It will help to a great extent if people stop consuming raw milk. But, the infrastructure for pasteurization and further packing is simply non-existent in many parts of India. So, mere pasteurization may not solve the issue for us”, opines Dr. Kulangara.

This study is an important step in bringing out the various antibiotic resistant strains of Staphylococci lurking in the country--a knowledge that is essential as these pathogens cause fatal invasive infections of skin, lungs, bloodstream and the urinary tract in humans. As drug resistance emerges as a striking threat, studies like this where both genetic as well as the antimicrobial profile of a bacteria are studied, will guide efficient treatment, spread and control of diseases in humans. 

Section: General, Science, Health, Society, Deep-dive Source:
New Delhi Saturday, 20 January, 2018 - 09:00

A coffee table book on the C V Raman International Fellowship for African Researchers, highlighting the successful journey of the programme, was launched jointly by the Federation of Indian Chambers of Commerce & Industry (FICCI) and the Department of Science and Technology (DST).

The book has been brought out by the Federation of Indian Chambers of Commerce & Industry (FICCI), in partnership with the Ministry of External Affairs (MEA) and the Department of Science & Technology (DST), Government of India. The fellowship scheme was introduced under the India-Africa Forum Summit (IAFS) to promote scientific cooperation between India and Africa.

The fellowship provides opportunities for African researchers to undertake research and training spanning between 1 to 6 months at Academic and Research Institutions in India. Since its inception, close to 500 scientists and researchers from African countries have undertaken R&D work in host institution in India. The programme has helped to take the footprint of Indian science to 40 countries across Africa.

Prof. Ashutosh Sharma, Secretary, DST noted that the C V Raman International Fellowship for African Researchers was one of the most prestigious programme of DST. He has also thanked the African partner nations for their overwhelming support in making the programme a great success and strengthening the bond of partnership through scientific and technological linkages, according to a release by FICCI.

The African scholars are able to nurture their research ideas under the guidance and mentorship of leading Indian scientists and academicians and benefit from access to advanced scientific facilities in premiere educational institutes and research laboratories in India.

Welcoming the guests, Mr. Nirankar Saxena, Deputy Secretary General, FICCI said “India’s C V Raman International Fellowship programme helps build capacity of African Researchers to scale research and cull out innovations that will shape the future of Africa and India”. Dr. Arabinda Mitra, Adviser, International Cooperation, DST who instrumented the scheme said, “The C V Raman International Fellowship is a unique programme to strengthen the bonds of scientific collaboration between India and Africa through supporting human capacity building, which will enable long term partnerships in research and development”.

Around 139 R&D institutions and laboratories, universities, colleges from across 70 cities in India have hosted African researchers under this programme over the last seven years. For a majority of the Fellows, the programme has contributed immensely to their career and helped them develop new research ideas in science and technology after returning to their home country.

The scheme has got overwhelming response from pan Africa and going forward, the partners expect to raise the number of research fellows to 1000 and continue strengthening the bond by creating a bridge of knowledge between Indian research expertise and African scholars. (Research Matters)

Section: General, Science, News, Events Source:
Mumbai Friday, 19 January, 2018 - 17:03

3.6 million lives could be lost in 2050 due to air pollution, says a recent study.

According to a new study by researchers from the Indian Institute of Technology-Bombay (IIT-B), the Health Effects Institute (HEI), and the Institute for Health Metrics and Evaluation (IHME), in 2015, only one in 1000 Indians lived in areas where particulate pollution did not exceed the permissible levels prescribed by World Health Organization (WHO).

The study, titled ‘Burden of Disease Attributable to Major Air Pollution Sources in India’ is the first comprehensive assessment on fine particulate matter (PM2.5) and their impacts on human health conducted in the country at the state and national level.

The study also found that in the same year, inhabitants of 21 Indian states and six union territories were exposed to PM2.5 levels higher than those deemed safe by the Indian annual standards. PM2.5 is a kind of air pollutant that consists of fine particles with a diameter of 2.5 microns or less. These particles can be detrimental to a person’s health, as their small size ensures that they escape the body’s mechanisms for protection against aerial pollutants, and settle in the respiratory system. Long term exposure to PM2.5 can lead to serious health complications.

The biggest culprit for air-pollution related health issues in India, in 2015, was found to be household biomass burning (23.9%) and coal combustion (15.3%), which contributed to around 268,000 and 169,000 deaths respectively.  Emissions from agricultural burning, dust, transport, other diesels, and brick kilns also contributed to the burden of air pollution, which collectively contributed to 231,000 deaths in the country.

The study was greatly helped by enhanced satellite data and India’s growing network of air pollution monitors. It  builds on the data collected by prior studies, which identified air pollution as the second highest public health risk factor, after malnutrition. Based on this data, the researchers evaluated future scenarios projecting to the year 2050 to identify the key challenges faced and to highlight possible mitigation measures.

“This systematic analysis of emissions from all sources and their impact on ambient air pollution exposure found significant contributions from regional sources (like residential biomass, agricultural residue burning and industrial coal), underlying that from local sources (like transportation and brick kilns)”, said Professor Chandra Venkataraman of IIT Bombay and one of the scientists involved in the study, in a press release. If no further measures are taken to reduce air pollution, 3.6 million lives could be lost in 2050, says the study.

To overcome these challenges, the researchers of this study recommend several actions that can be taken which could also reduce the number of human deaths by 2050. The use of LPG, piped gas and other alternative fuels could lead to the elimination of biomass use. A shift from using kerosene lamps to solar or electric sources of lighting would also significantly reduce the use of biomass. The authors recommend moving away from coal based power generation, and suggest that by 2050, 75%–80% of power generation has to be non-coal to reduce air pollution.

This study is one of the many that has sounded a warning death bell on air pollution in the country. But, are we listening?

Section: General, Science, Health, Society, Policy Source: Link
Bengaluru Friday, 19 January, 2018 - 07:33

In his 1959 lecture titled ‘There’s plenty of room at the bottom’, Richard Feynman envisioned the possibilities of manipulating and controlling things on a small scale. Today controlled manipulation of nanoscale objects, whose sizes are about a billionth of a metre, is a vast area of research. Manipulation of such nanoparticles requires trapping forces that can be focused and translated precisely. In a recent study, researchers from the Indian Institute of Science, Bengaluru, have designed a novel approach to trap and manoeuvre objects as small as 100 nm.

A major problem faced with conventional trapping techniques is their inability to hold extremely small sized objects, also called cargo. Imagine picking up grains of salt using only a pair of needles! What makes it tough is that the force required to capture a particle reduces as it’s size decreases.

So far, plasmonic tweezers -- nanosized tweezers made up of noble metals -- are used to trap such small sized cargo (think of a few molecules--that is the size we are talking about!). When illuminated by light, these tweezers create a strong electromagnetic field around themselves that can attract and trap nanoparticles that are close.

However, plasmonic tweezers have a limitation. With a limited range of influence and being fixed in space, these tweezers can only capture nanoparticles in their vicinity; hence being inefficient. “So, it is necessary to design a technique that has the efficiency of a traditional plasmonic tweezer but, at the same time, is manoeuvrable”, says Souvik Ghosh, a researcher from IISc, and a co-author of this study.

In this study, published in the journal Science Robotics, Mr. Ghosh, along with Prof. Ambarish Ghosh from Centre for Nanoscience and Engineering, IISc, have designed a new class of nanotweezers, that combines plasmonic tweezers with micro robots to design ‘mobile nanotweezers’ (MNTs) that bring together the best of both world. These nanotweezers can be driven to the target objects with precise control to capture, transport and release small sized cargo made of various materials with high speed and efficiency. "Microbots can carry/push objects very quickly, but do not work well for sub-micron objects. By combining the functions of these two technologies, we can not only trap but move very small objects very quickly" adds Mr. Ghosh.

The design of these mobile nanotweezers is inspired by microorganisms. Akin to a bacterium that moves by rotating its helical flagellum -- a cellular protrusion used for swimming -- these ferromagnetic, helical nanostructures can be moved by a uniform, rotating magnetic field, which moves and rotates along the direction of the magnetic field. By controlling the magnetic field, the motion of the nanotweezers can be controlled.

The researchers have designed two similar MNTs made of silicon dioxide. Silver and iron, combined with the nanostructures, provide plasmonic properties and magnetic properties. While the first design contains silver nanoparticles distributed across its surface, alternating layers of silver and iron are combined within the structure of the second.

The researchers tested the two designs in a fluid chamber containing some cargo particles. They magnetically steered the nanotweezers towards the cargo and when the chamber was illuminated, they observed that the nanotweezer trapped the cargo which was subsequently maneuvered and released by decreasing the illumination intensity. “The first design works very well for particles that accumulate near hot places like silica particles, while the second is very general and does not care whether the particles like heat or not. For a general application, the second design is preferred”, says Mr. Ghosh.

In addition, the researchers observed that when two particles of different sizes are present in the cargo, by decreasing the illumination, the smaller particle can be released, whereas increasing the frequency of the rotating magnetic field would release the larger particle. This unique sorting behaviour allows the transport of nanoparticles of different sizes by simply varying the two influences.

The researchers also tested their devices beyond plastic and glass particles. They successfully trapped and transported Staphylococcus aureus bacteria and subsequently released it by turning the illumination off. Illumination intensities required by these nanotweezers are almost two orders lower than that can damage living bacteria. Also fluorescent nanodiamonds, an excellent candidate for quantum sensing, was maneuvered using the MNTs.

“From being able to carry live bacteria to placing very small objects such as nanodiamonds and quantum dots at specific positions on a device, their applications could range from biomedicine to quantum technologies, sensor devices and many more”, Prof. A. Ghosh explains to Research Matters.

Apart from carrying small objects to various spots of a microfluidic device, the researchers can also localize them with high spatial resolution and then take them away if necessary. “This should open up new avenues in nanoscale assembly that did not exist before" adds Prof. Ghosh.

What comes next in this ‘small’ journey? “We are working on parallelizing the nanotweezers so that a collection of them can sort and assemble at nanoscale, just like a group of robots would work in an industrial assembly line. This will allow us to scale up our technology and will surely have tremendous commercial impact”, signs off Prof. Ghosh.

Section: General, Science, Technology, Deep-dive Source:
Bengaluru Thursday, 18 January, 2018 - 14:50

The Indian Institute of Science (IISc) proudly presents Pravega-- an annual science and cultural festival organized by the institute’s undergraduate community. The event will be held from 19 to 21 January, 2018.

This year, Pravega promises to have a little something for everyone, with a wide variety of events in diverse fields being conducted throughout the three days. For the science aficionados, there are more technical events than ever, with plenty of events like Decoherence and Hackathon being held on a national level.

The flagship event, Pravega Innovation Summit (PIS), is an unprecedented venture to bring about widespread collaboration between researchers and investors. This year will see many workshops in diverse fields, ranging from cyber security to automobile engines. The title sponsor Airbus, will also conduct a workshop for underprivileged children, to help them realize their dreams in the future.

To keep everyone entertained, the fest will feature many fun events and games, both technical and non-technical, which will be free to participate and play in. Pravega is also famous for being graced with renowned celebrities who entertain the audience, and this year promises to be the same with the well-known band Thaikkudam Bridge headlining the Pronites.

The general registrations for Pravega, as well as the Pronite registrations are free, and all are encouraged to visit the campus and satisfy their wanderlust. Details of registration can be found on pravega.org

Don’t want to participate in any events? Not a problem! Even non-participants will have plenty to catch their attention, with the cultural events and the beautiful campus to occupy their attention. Visit IISc and be a part of Pravega to experience an exquisite blend of scientific innovation and cultural delights.

Section: General, Events Source: Link
Bengaluru Thursday, 18 January, 2018 - 13:50

Prasad Raghavendra, Associate Professor of electrical engineering and computer science at the University of California, Berkeley, and David Steurer, professor of theoretical computer science at ETH Zurich have been chosen as the winners of the first Michael and Sheila Held prize. They were chosen “for a body of work which revolutionizes our understanding of optimization and complexity in computer science” announces a press release from the academy.

The duo will be awarded a cash prize of $ 100,000 during the Academy’s 155th annual meeting to be held on 29 April 2018.

Raghavendra and Steurer work on computational complexity--problems that are classified as hard and considered impossible for a computer to completely solve within a reasonable time frame. Their work helps determine if a computer can find an approximate solution to such problems. The duo showed that compared to other algorithms, semidefinite programming (SDP)—a type of optimization of complexity problems, gives the best possible approximation for several of the hard optimization problems. According to the press release from the academy,“the awardees have advanced a theoretical framework for SDP, which has led to new algorithms and a deeper understanding of SDP’s limitations.”

The Michael and Sheila Held prize presented for the first time this year, will be awarded annually to ‘honour outstanding, innovative, creative, and influential research in the areas of combinatorial and discrete optimization, or related parts of computer science, such as the design and analysis of algorithms and complexity theory’. The prize was established in 2017 by the bequest of Michael and Sheila Held.

The National Academy of Sciences (NAS) is a private, non-profit society of distinguished scholars, based in USA. The scientists are elected by their peers to membership in the NAS for outstanding contributions to research. The NAS, along with the National Academy of Engineering and National Academy of Medicine --provides science, technology, and health policy advice to the federal government and other organizations.

Section: General, Science, Events Source: Link
Bengaluru Thursday, 18 January, 2018 - 07:35

Climate change has always been a major driver that has shaped our planet’s biodiversity. Massive extinctions and severe adaptations are all a result of climate change. As we start to understand how the current change in climate is impacting us, effects of previous climate changes are hardly understood. In a rare study combining biology and paleontology, researchers from the Indian Institute of Science, Bengaluru, have shown how different climatic factors, present millions of years ago, have influenced the evolution of fan-throated lizards.

Fan-throated lizards (FTL) is a kind of agama found in India. Males of this species have an extendable dewlap or fan which is brightly coloured in some species. Until a few years ago, researchers thought that a single species of the genus Sitana, was present throughout the country. However, with increased efforts, 10 more species of Sitana and three more species of a new genus Sarada, were found over time. The study attributes this observed diversity to the onset of monsoon and subsequent aridification during the Miocene epoch--a geological period spanning from 23 million to 5.3 million years ago.

“In 2007, I saw some photographs of Sitana ponticeriana (fan-throated lizards) from Maharashtra that looked very different from those in Pondicherry. This was the first time when I got interested to study this group”, says Dr V. Deepak, the lead author of the study published in the journal Molecular Phylogenetics and Evolution. “These preliminary observations gave me the hint about the diversity within these lizards”, he recounts.

The researchers used genetic data of fan-throated lizards sampled from different regions where they were found. They then used tools to tell apart two or more distinct species tagged as a single species due to similarities in their looks and body characteristics. In their molecular dating they used five fossils and sequences of the different Fan-throated lizard species trying to understand the time at which different diversifications were observed.

“Molecular dating is a very useful tool if one understands the underlying principles. Typically, biologists rely on the information provided by paleontologists about the fossils. When paleontologists describe a fossil, they also estimate its age and the error associated with this number. Based on the morphological description of the fossil, paleontologists and neontologists (those who study living organisms as opposed to fossils) identify to which extant group (genus, family, subfamily) the fossils are related to. Given this information, a particular fossil can be placed in the molecular phylogeny to estimate the dates for the related species group of our interest”, informs Dr. Deepak about the methods used in this study.

In total, the team identified 15 species of fan-throated lizards, and discovered five potential new species of Sitana, and one new species of Sarada. They also found that the dry zone species of the Sarada-Sitana group diverged from the Sri Lankan wet zone sister genus Otocryptis at around 26 million years ago during early Miocene. Sitana and Sarada evolved as separate genera around 18 million years ago during mid-Miocene, which corresponds to the establishment of monsoon. During the late Miocene, around 11 million years ago, there was an increase in open habitats and a decline in rainforest habitats, with the initiation of aridification in South Asia. This helped Sarada and Sitana to further diversify into the present delimited species.

Also, 13 of the 15 delimited species were found from peninsular India. This greater diversity of fan throated lizards in peninsular India could be due to the availability of different types of habitat, compared to other relatively homogeneous dry zones of the subcontinent. Hence, climatic factors and landscape heterogeneity were found to have influenced current diversification  in this group.

The study has brought the evolutionary and conservation significance of the Indian arid zone, where lizard diversity is underestimated, to focus. Systematic documentation of lizards in this area is necessary, say the researchers. “I advocate taxonomy of different lizard species to be dealt with caution. One has to look at more than just traditional characters used in lizard systematics, examine as many museum specimens as possible before going out in the field. Zoological Survey of India has one of the oldest and widest arrays of collections in the country and this needs to be utilized”, recommends Dr. Deepak.

As we have entered Anthropocene, a human-influenced epoch, human-induced climate change has already started to take its toll on biodiversity. What does it mean for the fan-throated lizards? “These lizards are short-lived species with 1-2 years of lifespan. They typically breed just before monsoon when the habitats are dry and are more visible when they display and mate. After the breeding season that lasts up to 3 months, the females lay their eggs with 40 to 45 days of incubation period. This period roughly corresponds to the post-monsoon season when the young ones emerge. There is sufficient vegetation for them to hide and surplus insects to feed on. Therefore, the life cycle of these lizards is synchronized with the trends in current climatic conditions. If there is continuous disruption of the climatic cycle due to climate change it will indeed affect the long-term survival of many of the these species, particularly the range restricted species”, signs off Dr. Deepak.

Section: General, Science, Deep-dive Source:

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