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Gravitational physics in the context of Indian astronomy: A vision document
No full textContributions from the Indian gravity community have played a significant role in shaping several branches of astronomy and astrophysics. This document reviews some of the most important contributions and presents a vision for gravity research in the context of astronomy and astrophysics in India. This is an expanded version of one of the chapters in the recently released Vision Document of the Astronomical Society of India
Insulin fibrillation under physicochemical parameters of bioprocessing and intervention by peptides and surface-active agents
No full textEven after the centenary celebration of insulin discovery, there prevail challenges concerning insulin aggregation, not only after repeated administration but also during industrial production, storage, transport, and delivery, significantly impacting protein quality, efficacy, and effectiveness. The aggregation reduces insulin bioavailability, increasing the risk of heightened immunogenicity, posing a threat to patient health, and creating a dent in the golden success story of insulin therapy. Insulin experiences various physicochemical and mechanical stresses due to modulations in pH, temperature, ionic strength, agitation, shear, and surface chemistry, during the upstream and downstream bioprocessing, resulting in insulin unfolding and subsequent fibrillation. This has fueled research in the pharmaceutical industry and academia to unveil the mechanistic insights of insulin aggregation in an attempt to devise rational strategies to regulate this unwanted phenomenon. The present review briefly describes the impacts of environmental factors of bioprocessing on the stability of insulin and correlates with various intermolecular interactions, particularly hydrophobic and electrostatic forces. The aggregation-prone regions of insulin are identified and interrelated with biophysical changes during stress conditions. The quest for novel additives, surface-active agents, and bioderived peptides in decelerating insulin aggregation, which results in overall structural stability, is described. We hope this review will help tackle the real-world challenges of insulin aggregation encountered during bioprocessing, ensuring safer, stable, and globally accessible insulin for efficient management of diabetes
Influence of changes in anthropogenic and natural sources on global aerosol optical depth during COVID-19 lockdown: Ground-based observations, satellites, models
No full textWe analyze, in this study, for the first time, multi-source data - high-quality ground-based observations (Aerosol Robotic Network (AERONET)) and satellite (Moderate Resolution Imaging Spectroradiometer (MODIS) and Ozone Monitoring Instrument (OMI)) data in combination with two high resolution model (Modern-Era Retrospective Analysis for Research and Applications-2 (MERRA-2) and Copernicus Atmosphere Monitoring Service (CAMS)) outputs, and examine the changes in aerosol optical depth (AOD) across the globe during Corona Virus Disease-2019 (COVID-19) lockdown (2020) period. Statistical significance of the change in aerosol characteristics (AOD and species AODs) from normal (2017–2019 mean) to COVID (2020) period is calculated by two-tailed Student's t-test. AERONET AODs decreased by 20–40% during peak lockdown period in spring and summer of 2020 in most locations across the globe, and these changes are statistically significant. The observed magnitude of changes (increase/decrease) are consistent between AERONET and MODIS. Both global models (MERRA-2 and CAMS) capture well, observed AOD changes. OMI absorbing aerosol index captures increases in carbonaceous aerosols due to wildfires and dust. Global analysis reveals that changes in total AOD and species AODs are highest, and statistically significant during spring over Middle East, South and East Asia. Among all regions, change in dust AOD is maximum over South Asia during spring (>75%; −0.04 decrease in dust AOD in −0.05 change in total AOD) which is statistically significant. Black carbon (BC) and sea salt contribute ≤10% to AOD across the globe. Decrease in BC AOD is maximum over South Asia (50%) during spring 2020 providing a direct evidence for the impact of applied restrictions on anthropogenic activities. Decrease in AOD over North America, Europe, Russia, Middle East, South Asia, East Asia, and South East Asia led to global decrease in AOD. This quantitative documentation of changes in AODs due to reduction in aerosol components/species, their regional and seasonal variations are crucial in planning and supporting future mitigation efforts
Radial Acoustic Beamforming via Near-Field Array Processing in the Spherical Harmonics Domain
No full textWhen two speakers are in the same direction but at different distances, far-field beamforming fails to isolate the desired speech signal. We develop two radial acoustic beamformers using near-field processing for spherical microphone arrays (SMAs). First, we present the near-field array signal model in both the spatial and spherical harmonics (SH) domains, where the steering vector decomposes into separate radial and angular components - a key aspect we exploit. For the first beamformer, the desired speech time-frequency (TF) coefficients are modelled as zero-mean circular complex Gaussian random variables with time-varying variances; for the second, a Laplacian distribution is used to enhance the modelling of the desired speech at the beamformer output. Both beamformers enforce a distortionless constraint on the desired source and employ maximum likelihood estimation (MLE) to iteratively update the beamformer weights and TF-domain variances. Simulation results show our methods outperform the conventional technique in near-field scenarios
On the Applicability of Teaching–Learning-Based Optimization to Estimate the Vs Profile in Active MASW Test
No full textThis paper proposes the use of teaching–learning-based optimization on the Kausel-Roesset stiffness matrix (TLBO-KRSM) for estimating the site-specific shear wave velocity profile (Vs) in the active multichannel analysis of surface waves (MASW) test. Global search operations are carried out by teaching factor through the teaching–learning process in the TLBO algorithm to obtain converged solutions. The TLBO algorithm (free of control parameter) is expected to predict the Vs profile more accurately than traditional optimization techniques (e.g., genetic algorithm (GA), differential evolution (DE), artificial bee colony optimization (ABCO), and particle swarm optimization (PSO)). The control parameters of GA, DE, ABCO, and PSO are not sufficiently calibrated, so there is a high possibility of misinterpreting the site-specific Vs profile. It utilizes the wavelengths and phase velocities of the experimental fundamental mode dispersion curve to fix the search space of soil layer thicknesses and Vs. The proposed TLBO-KRSM algorithm and the other optimization techniques are examined on real field data sets by performing the MASW tests at the IIT Gandhinagar campus. The MASW test results are validated with downhole seismic tests along with the four datasets from various literature studies. When comparing the misfit error and the site-specific Vs profiles, the TLBO-KRSM algorithm has been found to be superior and requires less computational effort to locate the low misfit region to other optimization algorithms for estimating the Vs profiles
Early career ocean professionals’ declaration on ocean negative carbon emissions for our ocean and future
No full textThis paper highlights the urgent need to accelerate research and action on ocean carbon sinks through human intervention, known as the Global Ocean Negative Carbon Emissions (Global-ONCE) Programme, as a vital strategy in global efforts to mitigate climate change. Achieving “net zero” by 2050 cannot rely on emission reductions alone, emphasizing the necessity of complementary approaches. Global-ONCE's mission extends beyond scientific exploration. It embodies a profound commitment to protecting and restoring blue carbon ecosystems, as well as implementing ocean-based solutions that are sustainable, equitable, and inclusive. Early career ocean professionals (ECOPs) are at the heart of these efforts, and their innovative approaches, technical expertise, and passion make them indispensable leaders in advancing ONCE initiatives. ECOPs bridge the gap between science and society, playing a relevant role in integrating cutting-edge research, technological advancements, and community-driven action to address climate threats. By bringing together diverse perspectives and leveraging their interdisciplinary expertise, ECOPs ensure that ONCE strategies are grounded in scientific rigor and practical feasibility. Through advocacy, education, and collaboration, ECOPs not only spearhead research and innovation but also inspire collective action to safeguard our oceans. This paper amplifies the critical role of ECOPs as agents of change and calls for a unified global commitment to harness the ocean's potential for a climate-resilient future
Review Based Recommendations with Human-like Reasons
No full textRecommendation Systems are widely deployed for all kinds of services across various websites to enhance user experience. However, existing systems do not make efficient use of text data associated with products and users, available as reviews and blogs to relate them better. Many recent works have tried to improve the accuracy of rating prediction. However, very few works have attempted to justify the reason for a particular recommendation. Explaining the recommendation would help in gaining the trust of the user, and lend the system human-like credibility. In this paper, we propose a model that can recommend movies and generate a reasoning text to help the user understand why a film was recommended to them. We use three parallel neural networks with an enhanced BERT Embedding for Aspect Based Sentiment Analysis (ABSA) to predict rating. The Seq2Seq transformer model is used to generate the reasoning text. � 2022 Elsevier B.V., All rights reserved
Finite-time blow-up in the higher dimensional parabolic-parabolic-ODE minimal chemotaxis-haptotaxis system
No full textIn this article, we consider the following parabolic-parabolic-ODE minimal chemotaxis-haptotaxis system {ut=Δu−χ∇⋅(u∇v)−ξ∇⋅(u∇w),x∈Ω, t>0,vt=Δv−v+u,x∈Ω, t>0,wt=−vw,x∈Ω, t>0,[Formula presented]=0,x∈∂Ω, t>0,u(x,0)=u0(x),v(x,0)=v0(x),w(x,0)=w0(x),x∈Ω, in a bounded domain Ω⊂Rn,n⩾3 with smooth boundary. We show that the finite time blow-up occurs to the above system. More specifically, we establish that in a radial setting, the generic mass blow-up phenomenon observed in corresponding chemotaxis-only systems (obtained by setting w≡0) is preserved in chemotaxis-haptotaxis system. Our proof demonstrates that for a given initial mass, there exists radially symmetric positive initial data for which the corresponding solution blows-up. Moreover, we illustrate that such initial data constitute a considerably large set in the sense that it is dense in C0(Ω‾)×W1,∞(Ω)×C2(Ω‾) with respect to topology in Lp(Ω)×W1,2(Ω)×L∞(Ω), with p∈(1,[Formula presented]). Analogous results for corresponding parabolic-elliptic-ODE system [53] are already available, where the parabolic-parabolic-ODE case was open for further study