Indian Institute of Science
  • Bengaluru, Karnataka, India
Recent publications
An ecohydrological assessment of lotic ecosystems would provide insights into understanding the symbiotic interactions of hydrological and ecological processes for sustainable catchment management to ensure water security and achieve sustainable development goals (SDG). Global monitoring reveals changing climate patterns due to the unabated anthropogenic activities altering the ecohydrological behavior of waterscapes and thus affecting the sustenance of natural resources. The current research investigates the ecohydrological footprint using a modified water balance method by accounting for climatic and land-use trends across three river catchments in the northern portion of the Central Western Ghats. Assessment of landscape dynamics using temporal remote sensing data indicates the reduction in forest cover in Mahadayi, Ghataprabha, and Malaprabha river basins with increased anthropogenic activities. Evaluation of climate trends shows rising temperatures over 0.4 °C in the last century with increasing rainfall. The consequence of enhanced rainfall is increased overland flows to the extent of 35–80% in all river basins. Water availability in streams during all seasons is evident in the catchment dominated by native forest cover, while streams are intermittent and seasonal at the transition zone and plains. Analyses of temperature and rainfall in the last century indicate higher spatial variations directly influencing surface and subsurface hydrology. The reduced native forest cover has directly affected the variations in the local temperatures and precipitation patterns. This highlights the need for maintaining the ecological integrity of watersheds with native vegetation cover for sustaining the natural resources (water, etc.) that support the livelihood of farmers with socio-economic benefits.
We consider the problem of verifying the safety of the trajectories of a camera-based autonomous vehicle in a given 3D-scene. We give a procedure to verify that all trajectories starting from a given initial region reach a specified target region safely without colliding with obstacles on the way. We also give a prioritization-based falsification procedure that collects unsafe trajectories. Both our procedures are based on the key notion of image-invariant regions, which are regions within which the captured images are identical. We evaluate our methods on a model of an autonomous road-following drone in a variety of 3D-scenes; our experimental results demonstrate the feasibility and benefits of our approach for both safety analysis and falsification.
The development and operation of a nanosensor for detecting the poisonous 1-chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine (Atrazine) are described in this study for the first time. The carbon electrode (CE) surface was modified with cysteine-substituted naphthalene diimide to create this sensitive platform. The developed nanosensor (NDI-cys/GCE) was evaluated for its ability to sense Atrazine using differential pulse voltammetry and cyclic voltammetry. To achieve the best response from the target analyte, the effects of several parameters were examined to optimize the conditions. The cysteine-substituted naphthalene diimide significantly improved the signals of the Atrazine compared to bare GCE due to the synergistic activity of substituted naphthalene diimide and cysteine molecules. Under optimal conditions, atrazine detection limits at the (NDI-cys/GCE) were reported to be 94 nM with a linear range of 10-100 μM. The developed sensing platform also showed positive results when used to detect the atrazine herbicide in real tap water, wastewater, and milk samples. Furthermore, a reasonable recovery rate for real-time studies, repeatability, and stability revealed that the developed electrochemical platform could be used for sample analysis.
We studied the electrical transport, Hall effect, and magnetic properties of monoclinic layered ferromagnet Cr 2.76 Te 4. Our studies demonstrate Cr 2.76 Te 4 to be a soft ferromagnet with strong magnetocrystalline anisotropy. Below 50 K, the system shows an antiferromagnetic-like transition. Interestingly, between 50 and 150 K, we observe fluctuating magnetic moments between in-plane and out-of-plane orientations, leading to non-coplanar spin structure. On the other hand, the electrical resistivity data suggest it to be metallic throughout the measured temperature range, except a kink at around 50 K due to AFM ordering. The Rhodes-Wohlfarth ratio µ eff µ s = 1.89(> 1) calculated from our magnetic studies confirms that Cr 2.76 Te 4 is an itinerant ferromagnet. Large anomalous Hall effect has been observed due to the skew-scattering of impurities and the topological Hall effect has been observed due to non-coplanar spin-structure in the presence of strong magnetocrystalline anisotropy. We examined the mechanism of anomalous Hall effect by employing the first principles calculations.
Sleep is a dynamic and controlled set of physiological and behavioural practices during which the stabilisation and restoration processes of the body take place properly. Therefore, sleep disorders, especially chronic insomnia, can harm an individual’s physical and mental health. However, the therapeutic alternatives are limited and possess severe side effects. Thus, in this study, we aimed to investigate the anti-insomnia effect of a polyherbal formulation (Sleep) (SLP) on p-chlorophenyalanine (PCPA) induced insomnia in rats. Intraperitoneal injection of PCPA induced the experimental condition, and the therapeutic effect of SLP was evaluated by studying the sleep pattern and expression of various neurotransmitters and receptors, along with neurotrophins. Moreover, insomnia-associated oxidative stress and inflammation were also studied. From the findings, we found that the SLP-supplemented animals improved their sleeping behaviour and that the major neurotransmitters, hormones, and receptors were maintained at an equilibrium level. Furthermore, the neurotrophin level was increased and pro-inflammatory cytokines were reduced. The evaluation of oxidative stress markers shows that the antioxidants were significantly boosted, and as a result, lipid peroxidation was prevented. The overall findings suggest that SLP can be used as an effective medication for the treatment of sleep disorders like insomnia as it triggers the major neurotransmitter system.
The microRNA miR319 and its target JAW-TCP transcription factors regulate the proliferation-to-differentiation transition of leaf pavement cells in diverse plant species. In young Arabidopsis leaf primordia, JAW-TCPs are detected towards the distal region whereas the major mRNA319-encoding gene MIR319C , is expressed at the base. Little is known about how this complementary expression pattern of MIR319C and JAW-TCPs is generated. Here, we show that MIR319C is initially expressed uniformly throughout the incipient primordia and is later abruptly down-regulated at the distal region, with concomitant distal appearance of JAW-TCP s, when leaves grow to ~100 μm long. Loss of JAW-TCPs causes distal extension of the MIR319C expression domain, whereas ectopic TCP activity restricts MIR319C more proximally. JAW-TCPs are recruited to and are capable of depositing histone H3K27me3 repressive marks on the MIR319C chromatin. JAW-TCP s fail to repress MIR319C in transgenic seedlings where the TCP-binding cis -elements on MIR319C are mutated, causing miR319 gain-of-function-like phenotype in the embryonic leaves. Based on these results, we propose a model for growth patterning in leaf primordia wherein MIR319C and JAW-TCPs repress each other and divide the uniformly growing primordia into distal differentiation zone and proximal proliferation domain.
Coronal rain occurs in thermally unstable coronal loops, and comprises cool plasma condensations, falling towards the solar surface, guided by the magnetic field. Sometimes the coronal rain clumps are seen to be subjected to transverse oscillations. The numerical simulations have indicated that coronal rain can onset kink oscillations in coronal loops and can affect the properties of oscillations. In this proceeding, we present the analysis of transverse oscillations in conjunction with coronal rain. Atmospheric Imaging Assembly (AIA) is used to examine the characteristics of coronal loop oscillation before and after coronal rain development. The analysis showed that the amplitude and period of oscillations are greater during coronal rain.
The modeling and control of epidemics, such as the novel Coronavirus, have become crucial on a global scale, for effective management of epidemic situations. This paper is focused on using the mean field approach for modeling and control of epidemics. The mean field approach is an effective alternative to the classical approach of using continuous time Markov decision process (CTMDP) models, which suffer from the curse of dimensionality and entail knowledge of global state information. The mean field approach captures the collective behavior of a dynamic system consisting of numerous interacting nodes representing individuals in the population. The objectives of this paper are twofold: (a) to provide an overview of the mean field approach to epidemic modeling and control, and (b) to present recent advances in this area. Emphasizing the importance of containing and suppressing epidemic spread through non-pharmaceutical interventions, the paper highlights the need to minimize loss of lives, reduce suffering, and alleviate the burden on the public healthcare system. A potential challenge here is the presence of a section of the population who act on their free will and deviate from recommended best practices, which could lead to a potential public health crisis. Motivated by this, the paper explores two specific threads to modeling and control. The first thread assumes that individual nodes comply with a socially optimal control policy mandated by a regulatory authority. The second thread allows for independent and strategic behavior by the individual nodes, modeled as a mean field game, where the strategies of rational agents are based on mean field Nash equilibria. The paper begins by discussing the modeling of epidemics using an extended SIVR (Susceptible-Infected-Vaccinated-Recovered) compartmental model, accompanied by an illustrative example. Next, a literature review is provided, focusing on the mean field approach for socially optimal control of epidemics and how a regulatory authority can effectively contain the spread. Subsequently, the paper presents an update on the use of mean field game-based approaches in studying epidemic spread and control. Finally, future research directions in this important area are discussed.
Rare diseases (RDs) are those that affect a small fraction of the total population. In India, where resources are scarce, the healthcare infrastructure and policy framework are focused on mitigating diseases that affect a large number of people. As a result, many cases of RDs remain unreported, undiagnosed, and untreated. To understand the current level of RD awareness among healthcare professionals (HCPs) and researchers, as they are key stakeholders in diagnosis, treatment, policy making, and drug development, we conducted a survey based on identification of an RD, time for diagnosis, treatment options, and relationship with family history and geographic location. The survey was divided into two parts, one for researchers and the other for healthcare professionals, each consisting of 22 questions. We observed that among all our respondents, 31% of researchers and 29% of HCPs did not know the time required for diagnosis of a rare disease they mentioned in the survey. They identified the importance of family history but failed to realize its association with geographic location. The results from the exploratory study can provide information for enabling larger studies to develop recommendations and policies that can improve awareness about RDs in healthcare communities.
India has a massive burden of rare diseases (RDs), with an estimated 96 million people living with RDs but limited options for treatment. Repurposing drugs used for other common conditions are essential alternative for RDs due to their cost-effectiveness and reduced timeline. India’s patent regime prevents the evergreening of drugs, and a large generic manufacturing industry provides ample opportunity to explore the potential of repurposed drugs for treating RDs, known as repurposed orphan drugs (ROD). However, there is no portal or other source for information on orphan drugs in India. This study assesses the availability of RODs in India through quantitative analysis. In the absence of a separate orphan drug designation in India, we consider USFDA-approved orphan-designated products as the reference. We searched USFDA-approved RODs in recognized sources in India, such as CDSCO, AYUSH gazette, FSSAI, and Indian Pharmacopeia, which provides a list of drugs approved for marketing in India. We classified the drugs into separate groups based on their record from different sources and explored the regulatory implications of the differential representations. We found that almost 76% of the USFDA-approved RODs are listed in one of the Indian regulatory bodies’ records either in the same form (61%) or in a different fixed-dose combination. For 67 drugs no information was found, these drugs have to be imported for use. Only 17 of the 43 RDs mentioned in the National Policy for Rare Diseases, matched the indications listed for approval of one of the 279 RODs identified in the study. This underscores the scarcity of RD treatment and the pressing need for accessibility in India. This information on RODs will help relevant stakeholders to efficiently manage RDs in India. The study also highlights existing gaps in Indian regulatory databases that limits access to accurate information about the availability of drugs.
In this work, we present algorithms for the processing of periodic and non-periodic signals or data, both, in the spatial and temporal domains. For periodic data, we propose a Newton–Raphson-based algorithm that identifies the amplitudes, frequencies and phases of the sinusoidal components in the input signal to a high degree of accuracy. The algorithm is based firstly on the systematic identification of the candidate periodic functions that pass through most of the sampled data, and then identifying the ‘correct solution’ from among these multiple candidate solutions, i.e., identifying the input signal that actually generated the data. Since the final solution passes through all the data points almost exactly, and since it is periodic, the ‘leakage loss’ is almost zero. For non-periodic temporal signals, we devise an approximation for the continuous time Fourier transform, and show by means of various examples that it yields accurate results. Regarding computational efficiency, the Newton–Raphson based algorithm for periodic signals is obviously computationally more expensive than standard techniques which treat parameter estimation as a linear problem, but the emphasis at this stage in on developing a robust algorithm. The algorithm for non-periodic temporal signals is, however, computationally efficient as well, since it just involves a summation of derived expressions over the number of time intervals used in the approximation.
We show that the Friedmann–Lemaître–Robertson–Walker (FLRW) framework has an instability towards the growth of fluid flow anisotropies, even if the Universe is accelerating. This flow (tilt) instability in the matter sector is invisible to Cosmic No-Hair Theorem-like arguments, which typically only flag shear anisotropies in the metric. We illustrate our claims in the setting of “dipole cosmology”, the maximally Copernican generalization of FLRW that can accommodate a flow. Simple models are sufficient to show that the cosmic flow need not track the shear, even in the presence of a positive cosmological constant. We also emphasize that the growth of the tilt hair is fairly generic if the effective equation of state $$w \rightarrow -1$$ w → - 1 at late times (as it does in standard cosmology), irrespective of the precise model of dark energy. The generality of our theoretical result puts various recent observational claims about late time anisotropies and cosmic dipoles in a new light.
Correction for ‘Influence of time dependent laser-irradiation for tuning the linear–nonlinear optical response of quaternary Ag10In15S15Se60 films for optoelectronic applications’ by Abinash Parida et al., RSC Adv., 2023, 13, 4236–4248, https://doi.org/10.1039/D2RA07981J.
Colloidal processing of ceramics has gained significant attention in recent years owing to its widespread application in biomedical and various industrial sectors. Polymer-assisted colloidal synthesis offers additional advantages and possibilities for development of advanced ceramic materials. This review enumerates the ancient techniques for ceramic production, the factors influencing the surface chemistry in colloidal processing of ceramics, together with the description of the interparticle forces, such as electrostatic and van der Waals interaction, steric and depletion, that contribute majorly to surface chemistry involved in colloidal processing of ceramics. The literature pertaining to the surface chemical interactions of various ceramic materials with polymeric additives are surveyed. Finally, the developments underlying major advancements in colloidal processing of ceramic materials are highlighted.
A bstract The partition functions of free bosons as well as fermions on AdS 2 are not smooth as a function of their masses. For free bosons, the partition function on AdS 2 is not smooth when the mass saturates the Breitenlohner-Freedman bound. We show that the expectation value of the scalar bilinear on AdS 2 exhibits a kink at the BF bound and the change in slope of the expectation value with respect to the mass is proportional to the inverse radius of AdS 2 . For free fermions, when the mass vanishes the partition function exhibits a kink. We show that expectation value of the fermion bilinear is discontinuous and the jump in the expectation value is proportional to the inverse radius of AdS 2 . We then show the supersymmetric actions of the chiral multiplet on AdS 2 × S ¹ and the hypermultiplet on AdS 2 × S ² demonstrate these features. The supersymmetric backgrounds are such that as the ratio of the radius of AdS 2 to S ¹ or S ² is dialled, the partition functions as well as expectation of bilinears are not smooth for each Kaluza-Klein mode on S ¹ or S ² . Our observation is relevant for evaluating one-loop partition function in the near horizon geometry of extremal black holes.
The present study uses Galinstan as a test fluid to investigate the shock-induced atomisation of a liquid metal droplet in a high-Weber-number regime $(We \sim 400\unicode{x2013}8000)$ . Atomisation dynamics is examined for three test environments: oxidizing (Galinstan–air), inert (Galinstan–nitrogen) and conventional fluids (deionised water–air). Due to the readily oxidizing nature of liquid metals, their atomisation in an industrial scale system is generally carried out in inert atmosphere conditions. However, no previous study has considered gas-induced secondary atomisation of liquid metals in inert conditions. Due to experimental challenges associated with molten metals, laboratory scale models are generally tested for conventional fluids like deionised water, liquid fuels, etc. The translation of results obtained from conventional fluid to liquid metal atomisation is rarely explored. Here a direct multiscale spatial and temporal comparison is provided between the atomisation dynamics of conventional fluid and liquid metals under oxidizing and inert conditions. The liquid metal droplet undergoes breakup through the shear-induced entrainment mode for the studied range of Weber number values. The prevailing mechanism is explained based on the relative dominance of droplet deformation and Kelvin–Helmholtz wave formation. The study provides quantitative and qualitative similarities for the three test cases and explains the differences in morphology of fragmenting secondary droplets in the oxidizing test case (Galinstan–air) due to rapid oxidation of the fragmenting ligaments. A phenomenological framework is postulated for predicting the morphology of secondary droplets. The formation of flake-like secondary droplets in the Galinstan air test case is based on the oxidation rate of liquid metals and the properties of the oxide layer formed on the atomizing ligament surface.
A method has been described for accessing α‐seleno alkyl boronates. The selenoboration was achieved via the diboration of carbonyl compounds to give α‐oxyl boronates, which then undergo 1,2‐metalate rearrangement in the presence of lithium selenolates and trifluoroacetic anhydride (TFAA). A variety of structurally diverse substrates were compatible with this protocol and efficiently provides difunctionalized products from simple starting materials. The presence of the boronic ester in the resulting organoselenium compounds serves as a versatile synthetic handle for various functionalizations. Mechanistic studies revealed that the binding of selenium nucleophile to both the boron centers in α‐oxyl boronate esters.
The high prevalence of oral potentially-malignant disorders exhibits diverse severity and risk of malignant transformation, which mandates a Point-of-Care diagnostic tool. Low patient compliance for biopsies underscores the need for minimally-invasive diagnosis. Oral cytol-ogy, an apt method, is not clinically applicable due to a lack of definitive diagnostic criteria and subjective interpretation. The primary objective of this study was to identify and evaluate the efficacy of biomarkers for cytology-based delineation of high-risk oral lesions. A comprehensive systematic review and meta-analysis of biomarkers recognized a panel of markers (n: 10) delineating dysplastic oral lesions. In this observational cross sectional study, immu-nohistochemical validation (n: 131) identified a four-marker panel, CD44, Cyclin D1, SNA-1, and MAA, with the best sensitivity (>75%; AUC>0.75) in delineating benign, hyperplasia, and mild-dysplasia (Low Risk Lesions; LRL) from moderate-severe dysplasia (High Grade Dysplasia: HGD) along with cancer. Independent validation by cytology (n: 133) showed that expression of SNA-1 and CD44 significantly delineate HGD and cancer with high sensitivity (>83%). Multiplex validation in another cohort (n: 138), integrated with a machine learning model incorporating clinical parameters, further improved the sensitivity and specificity (>88%). Additionally, image automation with SNA-1 profiled data set also provided a high sensitivity (sensitivity: 86%). In the present study, cytology with a two-marker panel, detecting aberrant glycosylation and a glycoprotein, provided efficient risk stratification of oral lesions. Our study indicated that use of a two-biomarker panel (CD44/SNA-1) integrated with clinical parameters or SNA-1 with automated image analysis (Sensitivity >85%) or mul-tiplexed two-marker panel analysis (Sensitivity: >90%) provided efficient risk stratification of PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.
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9,109 members
Utkarsh Jain
  • Department of Microbiology and Cell Biology
Tapajyoti Das gupta
  • Department of Instrumentation and Applied Physics
Mohit Kumar Jolly
  • Centre for BioSystems Science and Engineering
Kiruba Daniel
  • Department of Instrumentation and Applied Physics
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Address
Malleswaram, 560012, Bengaluru, Karnataka, India
Head of institution
Prof. Govindan Rangarajan, Director
Website
www.iisc.ac.in