Soil Loss Estimation through USLE and MMF Methods in the Lateritic Tracts of Eastern Plateau Fringe of Rajmahal Traps, India

Laterites of Birbhum district are indentified as the ‘low-level laterites’ of ‘Rarh Plain’ of West Bengal and these are very much prone to severe soil erosion (mainly surface and sub-surface water erosion) in the monsoon season (June - September). Laterites and lateritic soils (locally named ‘Kankara’) of Caniozoic upland (adjoining areas of Rampurhat I block, Birbhum and Shikaripara block, Dumka- the study area), are the direct result of monsoonal wet-dry type of morpho-climatic processes and further laterisation of fluvial deposited materials (formation of surface duricrust) which was coming from Rajmahal Hills of eastern Chotanagpur Plateau (Jharkhand) in late Pleistocene. Such type of vermiform laterites is shaped and dissected by numerous gullies and ravines, giving birth of badland topography (locally named ‘Khoai’) of both degradation and aggradation processes. Before the soil conservation practices it is helpful if the assessment of soil erosion can be transformed into a statement of how fast soil is being eroded. The estimation of rate of annual soil loss is required in that case, because we must have to predict soil loss through effective models under a wide range of conditions. In this study the entire assessment is focused on the application Universal Soil Loss Equation (USLE) and Morgan, Morgan and Finney (MMF) methods in the soil loss estimation of sample slope segments, and relative comparison and suitability of both methods in the precise estimation of predicting soil loss.Keywords: Laterite, Gully, Rainsplash, Overland flow, USLE and MM

Crystal structure and magnetic properties of spin-1/21/2 frustrated two-leg ladder compounds (C4_4H14_{14}N2_2)Cu2X6_2X_6 (XX= Cl and Br)

We have successfully synthesized single crystals, solved the crystal structure, and studied the magnetic properties of a new family of copper halides (C$_4$H$_{14}$N$_2$)Cu$_2X_6$ ($X$= Cl, Br). These compounds crystallize in an orthorhombic crystal structure with space group $Pnma$. The crystal structure features Cu$^{2+}$ dimers arranged parallel to each other that makes a zig-zag two-leg ladder-like structure. Further, there exists a diagonal interaction between two adjacent dimers which generates inter-dimer frustration. Both the compounds manifest a singlet ground state with a large gap in the excitation spectrum. Magnetic susceptibility is analyzed in terms of both interacting spin-$1/2$ dimer and two-leg ladder models followed by exact diagonalization calculations. Our theoretical calculations in conjunction with the experimental magnetic susceptibility establish that the spin-lattice can be described well by a frustrated two-leg ladder model with strong rung coupling ($J_0/k_{\rm B} \simeq 116$ K and 300 K), weak leg coupling ($J^{\prime\prime}/k_{\rm B} \simeq 18.6$ K and 105 K), and equally weak diagonal coupling ($J^{\prime }/k_{\rm B} \simeq 23.2$ K and 90 K) for Cl and Br compounds, respectively. These exchange couplings set the critical fields very high, making them experimentally inaccessible. The correlation function decays exponentially as expected for a gapped spin system. The structural aspects of both the compounds are correlated with their magnetic properties. The calculation of entanglement witness divulges strong entanglement in both the compounds which persists upto high temperatures, even beyond 370~K for the Br compound.Comment: 13 pages, 9 figures, 2 table

A case study of bilayered spin-1/21/2 square lattice compound [VO(HCOO)2⋅_2\cdot(H2_2O)]

We present the synthesis and a detail investigation of structural and magnetic properties of polycrystalline [VO(HCOO)$_2\cdot$(H$_2$O)] by means of x-ray diffraction, magnetic susceptibility, high-field magnetization, heat capacity, and electron spin resonance measurements. It crystallizes in a orthorhombic structure with space group $Pcca$. It features distorted VO$_6$ octahedra connected via HCOO linker (formate anions) forming a two-dimensional square lattice network with a bilayered structure. Analysis of magnetic susceptibility, high field magnetization, and heat capacity data in terms of the frustrated square lattice model unambiguously establish quasi-two-dimensional nature of the compound with nearest neighbour interaction $J_1/k_{\rm B} \simeq 11.7$~K and next-nearest-neighbour interaction $J_2/k_{\rm B} \simeq 0.02$~K. It undergoes a N\'eel antiferromagnetic ordering at $T_{\rm N} \simeq 1.1$~K. The ratio $\theta_{\rm CW}/T_{\rm N} \simeq 10.9$ reflects excellent two-dimensionality of the spin-lattice in the compound. A strong in-plane anisotropy is inferred from the linear increase of $T_{\rm N}$ with magnetic field, consistent with the structural data.Comment: 9 pages, 7 figures, 1 tabl

Influence of Chain Length of Alcohols on Stokes' Shift Dynamics in Catanionic Vesicles

In this paper, we explore the

Biocatalytic Transfer of Pseudaminic Acid (Pse5Ac7Ac) Using Promiscuous Sialyltransferases in a Chemoenzymatic Approach to Pse5Ac7Ac-Containing Glycosides

Pseudaminic acid (Pse5Ac7Ac) is a nonmammalian sugar present on the cell surface of a number of bacteria including Pseudomonas aeruginosa, Campylobacter jejuni, and Acinetobacter baumannii. However, the role Pse5Ac7Ac plays in host–pathogen interactions remains underexplored, particularly compared to its ubiquitous sialic acid analogue Neu5Ac. This is primarily due to a lack of access to difficult to prepare Pse5Ac7Ac glycosides. Herein, we describe the in vitro biocatalytic transfer of an activated Pse5Ac7Ac donor onto glycosyl acceptors, enabling the enzymatic synthesis of Pse5Ac7Ac-containing glycosides. In a chemoenzymatic approach, chemical synthesis initially afforded access to a late-stage Pse5Ac7Ac biosynthetic intermediate, which was subsequently converted to the desired CMP-glycosyl donor in a one-pot two-enzyme process using biosynthetic enzymes. Finally, screening a library of 13 sialyltransferases (SiaT) with the unnatural substrate enabled the identification of a promiscuous inverting SiaT capable of turnover to afford β-Pse5Ac7Ac-terminated glycosides.</p

Organic-Inorganic Nanostructure Architecture via Directly Capping Fullerenes onto Quantum Dots

A new form of fullerene-capped CdSe nanoparticles (PCBA-capped CdSe NPs), using carboxylate ligands with [60] fullerene capping groups that provides an effective synthetic methodology to attach fullerenes noncovalently to CdSe, is presented for usage in nanotechnology and photoelectric fields. Interestingly, either the internal charge transfer or the energy transfer in the hybrid material contributes to photoluminescence (PL) quenching of the CdSe moieties.open2

An ATP and Oxalate Generating Variant Tricarboxylic Acid Cycle Counters Aluminum Toxicity in Pseudomonas fluorescens

Although the tricarboxylic acid (TCA) cycle is essential in almost all aerobic organisms, its precise modulation and integration in global cellular metabolism is not fully understood. Here, we report on an alternative TCA cycle uniquely aimed at generating ATP and oxalate, two metabolites critical for the survival of Pseudomonas fluorescens. The upregulation of isocitrate lyase (ICL) and acylating glyoxylate dehydrogenase (AGODH) led to the enhanced synthesis of oxalate, a dicarboxylic acid involved in the immobilization of aluminum (Al). The increased activity of succinyl-CoA synthetase (SCS) and oxalate CoA-transferase (OCT) in the Al-stressed cells afforded an effective route to ATP synthesis from oxalyl-CoA via substrate level phosphorylation. This modified TCA cycle with diminished efficacy in NADH production and decreased CO2-evolving capacity, orchestrates the synthesis of oxalate, NADPH, and ATP, ingredients pivotal to the survival of P. fluorescens in an Al environment. The channeling of succinyl-CoA towards ATP formation may be an important function of the TCA cycle during anaerobiosis, Fe starvation and O2-limited conditions

Noncovalent Interactions of Hydrated DNA and RNA Mapped by 2D-IR Spectroscopy

Biomolecules couple to their aqueous environment through a variety of noncovalent interactions. Local structures at the surface of DNA and RNA are frequently determined by hydrogen bonds with water molecules, complemented by non-specific electrostatic and many-body interactions. Structural fluctuations of the water shell result in fluctuating Coulomb forces on polar and/or ionic groups of the biomolecular structure and in a breaking and reformation of hydrogen bonds. Two-dimensional infrared (2D-IR) spectroscopy of vibrational modes of DNA and RNA gives insight into local hydration geometries, elementary molecular dynamics, and the mechanisms behind them. In this chapter, recent results from 2D-IR spectroscopy of native and artificial DNA and RNA are presented, together with theoretical calculations of molecular couplings and molecular dynamics simulations. Backbone vibrations of DNA and RNA are established as sensitive noninvasive probes of the complex behavior of hydrated helices. The results reveal the femtosecond fluctuation dynamics of the water shell, the short-range character of Coulomb interactions, and the strength and fluctuation amplitudes of interfacial electric fields.Comment: To appear as Chapter 8 of Springer Series in Optical Sciences: Coherent Multidimensional Spectroscopy -- Editors: Cho, Minhaeng (Ed.), 201