Presidency University, Kolkata

About: Presidency University, Kolkata is a education organization based out in Kolkata, West Bengal, India. It is known for research contribution in the topics: Crystal & Single crystal. The organization has 2759 authors who have published 4750 publications receiving 53794 citations. The organization is also known as: Presidency College & Hindu College.

Mechanism of Salinity Tolerance in Plants: Physiological, Biochemical, and Molecular Characterization

Abstract: Salinity is a major abiotic stress limiting growth and productivity of plants in many areas of the world due to increasing use of poor quality of water for irrigation and soil salinization. Plant adaptation or tolerance to salinity stress involves complex physiological traits, metabolic pathways, and molecular or gene networks. A comprehensive understanding on how plants respond to salinity stress at different levels and an integrated approach of combining molecular tools with physiological and biochemical techniques are imperative for the development of salt-tolerant varieties of plants in salt-affected areas. Recent research has identified various adaptive responses to salinity stress at molecular, cellular, metabolic, and physiological levels, although mechanisms underlying salinity tolerance are far from being completely understood. This paper provides a comprehensive review of major research advances on biochemical, physiological, and molecular mechanisms regulating plant adaptation and tolerance to salinity stress.

In the realm of the Hubble tension - a review of solutions

Abstract: The $\Lambda$CDM model provides a good fit to a large span of cosmological data but harbors areas of phenomenology. With the improvement of the number and the accuracy of observations, discrepancies among key cosmological parameters of the model have emerged. The most statistically significant tension is the $4-6\sigma$ disagreement between predictions of the Hubble constant $H_0$ by early time probes with $\Lambda$CDM model, and a number of late time, model-independent determinations of $H_0$ from local measurements of distances and redshifts. The high precision and consistency of the data at both ends present strong challenges to the possible solution space and demand a hypothesis with enough rigor to explain multiple observations--whether these invoke new physics, unexpected large-scale structures or multiple, unrelated errors. We present a thorough review of the problem, including a discussion of recent Hubble constant estimates and a summary of the proposed theoretical solutions. Some of the models presented are formally successful, improving the fit to the data in light of their additional degrees of freedom, restoring agreement within $1-2\sigma$ between {\it Planck} 2018, using CMB power spectra data, BAO, Pantheon SN data, and R20, the latest SH0ES Team measurement of the Hubble constant ($H_0 = 73.2 \pm 1.3{\rm\,km\,s^{-1}\,Mpc^{-1}}$ at 68\% confidence level). Reduced tension might not simply come from a change in $H_0$ but also from an increase in its uncertainty due to degeneracy with additional physics, pointing to the need for additional probes. While no specific proposal makes a strong case for being highly likely or far better than all others, solutions involving early or dynamical dark energy, neutrino interactions, interacting cosmologies, primordial magnetic fields, and modified gravity provide the best options until a better alternative comes along.[Abridged]

Raman and infrared spectra of carbonates of calcite structure

Abstract: The Raman and mid-range infrared spectra have been measured on natural limestone and dolomite minerals. The carbonate minerals show four prominent absorption bands in the regions 1450–1420, 890–870, 720–700 and 1000–1100 cm−1. The positions of the wavenumbers are unique for each carbonate mineral and are thus diagnostic of their mineralogy. Calcite and dolomite groups are characterized by the Raman wavenumbers at 288 and 309 cm−1 and the infrared absorption bands at 712 and 728 cm−1, respectively. The principal wavenumber at 1092 cm−1 in the limestone spectra is accompanied by two satellites with values of 1062 and 1075 cm−1. The observed non-split peaks ν2 and ν4 in the infrared spectra of limestone indicate the presence of calcite structure in all these samples. The principal reflections occurring at the d-spacings, 3.03482, 1.91658 and 1.87962 A, confirm the presence of calcite structure in limestone minerals. The principal reflections occurring at the d-spacings, 3.037, 1.79179 and 2.19750 A, confirm the existence of dolomite structure in the dolomite minerals. The calculated lattice parameters for the limestone minerals are: a = 4.9781 A, c = 17.1188 A and V = 367.392(A)3 and the corresponding values for the dolomite minerals are: a = 4.8247 A, c = 15.9868 A and V = 322.28 (A)3. Copyright © 2006 John Wiley & Sons, Ltd.