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Friday, 6 October, 2017 - 13:17

Ever wondered if natural surroundings give out subtle hints before going through landscape level transformations? Scientists from Princeton University (USA) and Indian Institute of Science (India), have collaborated to try and figure out if there are any such hints or signs in nature, which can help in predicting transformations within grassland and woodland habitats in Serengeti-Mara. The researchers were working on ‘Critical Slowing Down’ (CSD), a phenomenon where as ecosystems approach natural landscape-level changes (regime shifts), they tend to become slow to recover from external disturbances in nature (also called perturbations). A few common examples of such perturbations are earthquakes, floods, storms, forest fires and even human-induced alteration of forests, wetlands and other natural landscapes. The researchers used ‘rainfall’ as a potential indicator, that brings about changes among grassland-woodland landscapes. With the help of information retrieved from satellite imagery and by using advanced statistical modelling, they have come close to predicting these transformations before they occur. ‘CSD effect’ has been tested and proven in laboratory settings as well as in well-mixed landscape systems. But this is the first time scientists are trying to study its effect on a large landscape-level scale. The study was also able to detect ‘sensitive regions’ within the grassland-woodland habitat which are more prone to regime shifts. The researchers further suggested that more such landscape-level experiments on the ‘CSD effect’ are needed, to prove it as a robust technique in identifying early signs of changes within large ecosystems. 

Section: General, Science, Ecology Source: Link
Thursday, 5 October, 2017 - 12:49

Research at the Indian Institute of Science, Bengaluru and Vikram Sarabhai Space Centre, Thiruvananthapuram indicates that black carbon (BC) aerosol emissions from aircrafts could be impacting the stratospheric ozone layer. Aerosols are minute particles suspended in the atmosphere that interact with incoming and terrestrial radiation affecting the earth’s climate. Some aerosols, such as sulphates and,  nitrates cool the atmosphere. BC, on the other hand, is a positive climate forcing agent, absorbing radiation across a wide range of wavelengths. Near the earth’s surface, BC concentration is known to disturb large scale atmospheric phenomena such as the Asian monsoon, and melt the Himalayan glaciers. By heating the lower atmosphere, it can also set off a convection system lifting the BC across the tropopause. Hence, it is important to understand the vertical distribution of BC under strong convection, such as over India during the monsoons. Lidar based studies have shown a near steady vertical distribution up to a height of 3 km. Recently, for the first time in India, hydrogen balloons were sent up into the atmosphere, over Hyderabad, to study the impacts of elevated BC concentration layers. Their in-situ measurements revealed sharp confined layers of BC at high altitudes of 4.5 km and 8 km over the Indian region. In the current study, researchers revisited these high-altitude balloon measurements to investigate possible causes for the presence of confined BC layers using a regional chemistry transport model. The model simulated vertical profile matched with the balloon measurements at lower altitudes of 3 km, but failed to capture the sharp confined BC peaks at high altitudes. This led the team to look for other sources of local BC injection at mid and upper troposphere, such as air traffic emissions. When incorporated into the model, it showed sharp BC layers in the vertical profiles akin to the observed BC profiles, indicating a causal role. The team also found noticeable levels of aerosols in the stratosphere using CALIPSO Lidar data over India. With an average residence time of 1 year, stratospheric BC aerosol pose a serious concern to the ozone layer and the new study is a step in the right direction.

Section: General, Science, Engineering, Health Source: Link
Wednesday, 4 October, 2017 - 15:01

Hepatitis C Virus (HCV) affects 6-11 million people in India. Chronic HCV infection is the leading cause for liver-related deaths worldwide. In India, HCV infection was estimated to be responsible for 59,000 deaths in the year 2015. Moreover, untreated HCV infection could also lead to substantial economic burden. However, the advent of directly acting antivirals (DAAs), is proving to be a game changer in HCV treatment. Directly acting antivirals target specific enzymes and the genetic material in HCV, hence stopping the spread of the infection. A recent study by a team of researchers from the Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), Massachusetts General Hospital and the World Health Organization (WHO) indicate that treatment of HCV by DAAs are not only cost effective but actually saves lifetime costs for treating infected patients. DAAs which were introduced in 2011, are remarkably successful in the battle against HCV infection, with cure rates above 95 percent. In developed countries like the US, treatment with DAAs is very expensive - reaching nearly $ 65,000. However the costs come down drastically for countries like India to a mere $ 300. This has been possible solely because of the agreements with the pharmaceutical companies that developed these drugs and generic drug manufacturers in India that produce similar versions of the drug. The study has revealed the profitability of such a system for treatment of HCV as the data strongly suggests that money on HCV treatment today, can be recovered in the form of reduced health care expenditure within a decade. Despite the low cost, it has been seen that only a small proportion of people needing these drugs have received them. The researchers attribute this to the lack of funding for HCV treatment and the absence of sufficient data showcasing the advantages of generic DAAs. This study therefore provides a strong evidence for policy makers in countries like India to invest in HCV treatment and screening and also advocate the use of generic DAAs.

Section: General, Science, Health Source: Link
Tuesday, 3 October, 2017 - 15:24

Climate change is here and governments around the world are trying their best to stem its debilitating impacts. REDD+ (Reduce Emissions from Deforestation and forest Degradation), a programme to encourage the sustainable management of existing forests that take in large amounts of greenhouse gases, is a step in this direction. However, there are technical difficulties in measuring the effectiveness of REDD+. Scientists from the Center for International Climate Research, Oslo and the Indian Institute of Science, Bangalore have now combined different methods in an attempt to address these difficulties. By combining the knowledge from characteristics of forest plantations and the market forces that forest managers respond to, current methodologies that measure REDD+ effectiveness can be improved. The scientists also found that management of REDD+ projects have consequences at the national and international levels. In places where the forests protected under REDD+ grow slowly, outside forests cater to the demand and thus, prices for forestry products do not increase widely. In contrast, in places where forests grow quickly, there is no such need to increase production in outside forests and thus, prices rise up in the first year. These differences are, however, ironed out over time by market forces. Responses to forest characteristics have consequences for the amount of carbon swallowed by the forests – protected and unprotected -- due to either change in production or change in carbon storage. In places that have a chance to adapt better to market forces (like in places with slow-growing forests), the costs of implementing REDD+ projects increase.  But it is also important to consider indirect effects. When forests are protected, those who buy timber and other forestry products will turn to unprotected plantations to make up for this deficit. Prices and volume of forestry products from these unprotected plantations will increase. This has a cascading effect on the local economic market which also seeps into the foreign trade. By combining the best of different approaches and by considering different perspectives, the current work can now tell us if REDD+ projects are effective.

Section: General, Science, Society, Policy Source: Link
Thursday, 28 September, 2017 - 12:34

Qissa-e-Sanjan, or the Story of Sanjan, records the epic tale of Parsi migration. It describes how a section of Zoroastrians left Iran to escape the Islamic conquest, and found India’s shores at Sanjan in Gujarat. Instead of a welcome they were presented with a full glass of milk, which symbolically suggested that there was no space for the newcomers. The priest then added a spoonful of sugar without spilling the milk, a promise that the Parsis would assimilate with the local community. Like sugar in milk, the Parsis found a new home. A recent study conducted by scientists from several countries including India, Pakistan and the United Kingdom, has actually retraced this tale. DNA samples were collected from Indian and Pakistani Parsis, as well as the remains of Parsis from the 15-16th century. The study found that both the Indian and Pakistani Parsi were more closely related to Iranians rather than their neighbours, Gujaratis and Sindhis. Interestingly, they are more closely related to the Iranians from several centuries ago than they are to modern day Iranians. This goes on to prove that the population fled Iran before the conquest, an evidence they carry today in their genes. After analysing specific sequences, the study concluded that there was first a male migration from Iran. Following which, there was an assimilation of women from South Asian. However, there is evidence of high level of interbreeding too as it is considered important to preserve their religion and culture. Today, the Indian government is taking steps to preserve the Parsi population which is slowly dwindling. Like sugar in milk they have added their distinct sweetness to the Indian community and become a part of it. They have still retained their distinct sweetness, even in their DNA! It is a rarity when science, history and stories have come together to explain the interesting origin of a people.

Section: General, Science, Society Source: Link
Wednesday, 27 September, 2017 - 12:15

Lentil (Lens sp.)  is an edible pulse cultivated as a staple food throughout the regions of India, Sri Lanka, Pakistan, Bangladesh and Nepal. It is an important dietary supplement in the Indian sub-continent. In a new study, scientists from the Indian Council of Agricultural Research (ICAR) have evaluated 162 genotypes including wild accessions, landraces, breeding lines and cultivars of lentil for their salt tolerance. This was based on four broad factors. First, the morphological characteristics like germination, seedling growth, biomass accumulation, seedling survivability and salinity scores were assessed. Next, anatomical characteristics such as root and shoot anatomy were examined, followed by analysis of physiological characteristics such as Na+, Cl-, K+ concentrations. Lastly, molecular characteristics such as proline and antioxidant activities were considered. The researchers evaluated the genotypes under hydroponics, where plants are grown without soil but only mineral enriched nutrient water, and under field experiments. The study reveals that growing plants in hydroponics helps in distinguishing the salt tolerant varieties from their non-tolerant counterpart at the seedling stage. The important finding of the study was that out of the 162 genotypes studied, the wild accession ILWL-137 and the breeding line PDL-1 genotypes proved to be more salt tolerant, whereas the cultivated lines turned out to be salt sensitive. Under 120mM concentration of salt stress in the hydroponics, the wild genotypes showed thick epidermis and increased vascular bundles. This modification helps in slowing down the uptake and transport of salts such as Na+ and Cl- to the plant parts. Under stress, plants tend to produce H2O2 as a signaling molecule for defense. Decreased H2O2 production was observed in wild genotypes when compared to the other cultivars. Increased K+ and proline accumulation was observed which indicates the adjustment capacity of the plants to the salt stress. An increase in antioxidant enzyme activities, seedling growth, biomass and seedling survivability , pods and seed yield were observed. All these characters help in distinguishing a salt tolerant variety of lentil from a salt sensitive one at different stages of their growth period, i.e., seedling, vegetative, reproductive, etc. While the molecular characterization of the 162 genotypes was unsuccessful in categorizing the genotypes based on salt tolerance, the assortment helped in selecting contrasting lines for further studies on improving salt tolerance in lentil. These findings help in selection of the right characteristics of salt tolerance and for incorporating them in cultivated genotypes through conventional breeding or genetic engineering.

Section: General, Science Source: Link
Tuesday, 26 September, 2017 - 11:10

Do you wish sometimes that you didn’t understand the consequences of cancer? The disease continues to terrorize mankind, mentally and economically. In order to develop therapy, you need suitable drug targets. Step in, non-B structures. These are simply, irregular DNA structures. A few examples of these structures are G-quadruplex or GQ, which is rich in guanine and intercalated motif or i-motif which is a guanine-rich and cytosine-rich DNA quadruplex. Several reports summarize that these structures could be related to genetic instability. Double stranded breaks or DSBs spell doom for DNA as they interrupt replication during cell division. Though the mechanism of DSB is still poorly understood, a few hints have been observed. Genome wide mapping and analyses of Spo11-catalyzed DSBs in Saccharomyces cerevisiae have shown a relation between DSBs and high guanine/cytosine-rich motifs. Is it possible that these non-B DNA structures are the culprits at meiosis specific DSB sites? Scientists at the Indian Institute of Science, Bangalore, have demonstrated that the guanine-rich sequence and cytosine rich sequence, which were derived from a meiosis-specific DSB site are capable of folding into a GQ and i-motif conformation respectively in S.cerevisiae cells. Both structures were found to be stable under physiological conditions. The conformations are also capable of blocking primer extension by DNA polymerase. Flow cytometry revealed decreased levels of green fluorescent protein or gfp mRNA expression of 75-85% as compared with the control, which suggest that i-motif and GQ can poke their noses in between cellular processes involving DNA or RNA. Particularly in S.cerevisiae, the C-terminal of the Hop1 protein, called as Hop1CTD formed a discrete band in the gel during the electrophoretic mobility shift assay indicating that it binds efficiently to the i-motif structure. This could mean that Hop 1 plays a role in processing of meiosis specific DSB-ends. In conclusion, the non-B structure can prove to be a significant angel and devil. They are capable of messing with replication and contribute to cancer, but there’s a sunny side too. They can serve as good drug targets as their presence will aid in detecting and studying mutations which will serve as a potential gateway to lessen the repercussions of genetic diseases in the future.

Section: General, Science, Health Source: Link
Monday, 25 September, 2017 - 08:11

The need for effective and rapid bone regeneration treatments is crucial now more than ever, due to the ever-rising number of bone defects and fractures. Conventional bone regeneration like grafts suffer from a shortage of available donors as well as added complications due to the immune rejection of the grafts. To overcome these issues, newer methods of bone regeneration like bone tissue engineering, are fast becoming the preferred method of treatment, owing to their ease of use, lower medical costs as well as the absence of complications associated with bone grafts. Bone tissue engineering involves surgically implanting biodegradable biomaterials in the form of three dimensional (3D) scaffolds that can support and aid bone cells and growth factors naturally found in the body to repair the damaged bones. Scientists from the Indian Institute of Science, Bengaluru have now comprehensively studied polymers derived from two families of polyesters to come up with ways of manipulating the properties of these biomaterials. They synthesized biodegradable polymers made up of monomers of either galactitol and adipic acid or galactitol and dodecanedioic acid, and further crosslinked them with monomers such as citric acid, glutaric acid, maleic acid, malic acid, succinic acid, and tartaric acid. These crosslinking monomers are non-toxic and are naturally found in the body or in foods that we commonly eat, and are easy to both produce artificially as well as metabolize in the body. The scientists systematically compared the physical properties of the different polymers obtained with the varying crosslinking processes, and tried to correlate them with the patterns of their crosslinking. Their study demonstrates that properties like mechanical strength and hydrophobicity could be increased with increase in cross-linking. On the other hand, properties like biodegradability and sustained release of drugs attached to these biomaterials, could be decreased with increase in crosslinking. Thus, a smart and appropriate selection of cross-linking monomers can be a very effective tool for modulating the physical & chemical properties of the biodegradable biomaterials.

Section: General, Science, Technology, Health Source: Link
Friday, 22 September, 2017 - 11:43

Polycyclic aromatic hydrocarbons (PAHs) are a group of chemicals produced after burning wood, coal, garbage, gas and oil. PAHs might occur naturally from sources like volcanoes and forest fire or they might be produced by various human activities. More than 100 PAHs are known and many of them are very common around us. The smoke of a cigarette, meat cooked in high temperature, naphthalene - the toilet deodorizer and asphalt covering the roads, all contain PAHs. Polycyclic aromatic hydrocarbons are commercially used for making dyes, medicine, pesticides and plastic. A research group from Indian Institute of Technology (Indian School of Mines), Dhanbad has recently reported their assessment on the risks of developing a cancer following exposure to PAHs in contaminated soils and sediments across India. Accumulation of PAH in our surrounding might be a major threat to us as many PAHs are considered as potential cancer causing agents. The concentration of PAH from different regions of India were found to differ significantly. A nearby industry or unplanned discharges of untreated industrial effluents were found to be major causes leading to the accumulation of PAHs. Ingestion of these chemicals into our body could happen in many ways; in soils, maximum exposure happens through skin whereas contaminated food is the major route of exposure to PAHs in sediments. Although the potential risks from soil PAHs in India are in an acceptable range, the high risk potential for PAHs in sediments is a major concern. One need to take special precautions to remain protected from exposure to these chemicals. Avoiding fish from contaminated sediments and reducing exposure to skin by covering our body are some potential solutions. This study also indicated that some special regions of India like Bhavnagar coast, Raniganj, Sunderban, Raipur and Delhi are heavily polluted with PAHs and special measures should be ensured by the government to reduce exposure.

Section: General, Science, Health, Society Source: Link
Thursday, 21 September, 2017 - 12:33

The term vaccine needs no introduction to most people living in the 21st century, but vaccines are also widely used for preventing diseases in animals like cattle and Foot and mouth disease is one such disease, which affects hoofed animals like cow, pigs, goat and sheep. Vaccines for foot and mouth disease are made by inactivating the foot and mouth disease virus (or FMDV), but retaining the integrity of a viral particle called the 146S particle.  This particle is vital for triggering the animal’s immune system to produce neutralizing antibodies against FMDV and building immunity against the foot and mouth disease. Historically, the FMD virus was inactivated using formaldehyde treatment, which often led to improper inactivation, and served the risk of causing an infection. Further, replacements like binary-ethylenimine and N-acetyl-ethylenimine were effective in inactivating the virus, but were found to be toxic and did not have the potency of formaldehyde. Scientists further thought of using a combination of these inactivating agents to achieve the optimal inactivation rates. This approach has mostly been successful, in terms of increasing both the inactivation rates of the virus as well as the yield of 146S particles obtained for making the vaccines. Now, scientists from Indian Veterinary Research Institute, Bengaluru have conducted an extensive study to evaluate the inactivation of Indian vaccine strains of FMDV using a combination of reagents like formaldehyde, binary ethylenimine and glutaraldehyde. Their study shows that in general, using a combination of binary ethylenimine and formaldehyde was seen to be a better inactivation agent than using binary ethylenimine with glutaraldehyde, or using only binary ethylamine. They also saw no major changes in the 146S content of the virus strains during the inactivation process. Using such a combination of inactivating agents could allow the inactivation process to be carried out much faster, and could aid in the development of a faster, safer and more standardized vaccine production process.

Section: General, Science, Health Source: Link

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