Community based risk assessment and adaptation to climate change in the coastal wetlands of Bangladesh

In recent decades, community based adaptation to climate change has gained enormous attention from scientists, policy makers and development professionals. This paper presents community based risk assessment for identification of risk and local adaptation practices as a response to climate change. The south-western coastal region of Bangladesh was selected as the study area and historical change-chronology study was conducted using statistical analyses and studying community perception. The community’s experience suggests risks are shifting both in magnitude and direction with the increasing frequencies of hydro-meteorological events and their irregularities are threatening adaptation capacities as they are affecting the sensitivity and production of the ecosystem of the region. Communities are increasingly depending on non-agricultural activities while the required time to be spent earning livelihoods is increasing. People are migrating from their traditional occupations towards non-agricultural ccupations. In such cases, local adaptation practices are almost absent in the region except for the application of more incentives to compensate production losses. Concerned authorities need to understand the nature of community adaptation and perceptions of climate change in coastal Bangladesh if the country wants to stride forward to negotiate climate change

From interpolative contractive mappings to generalized Ciric-quasi contraction mappings

[EN] In this article we consider a restricted version of Ciric-quasi contraction mapping for showing that this mapping generalizes several known interpolative type contractive mappings. Also here we introduce the concept of interpolative strictly contractive type mapping T and prove a fixed point theorem for such mapping over a T-orbitally compact metric space. Some examples are given in support of our established results. Finally we give an observation regarding (λ, α, β)-interpolative Kannan contractions introduced by Gaba et al.First and second authors acknowledge financial support awarded by the Council of Scientific and Industrial Research, New Delhi, India, through research fellowship for carrying out research work leading to the preparation of this manuscript.Roy, K.; Panja, S. (2021). From interpolative contractive mappings to generalized Ciric-quasi contraction mappings. Applied General Topology. 22(1):109-120. https://doi.org/10.4995/agt.2021.14045OJS109120221C. B. Ampadu, Some fixed point theory results for the interpolative Berinde weak operator, Earthline Journal of Mathematical Sciences 4 no. 2 (2020), 253-271. https://doi.org/10.34198/ejms.4220.253271S. Banach, Sur les opérations dans les ensembles abstraits et leur application aux équations intégrales, Fund. Math. 3 (1922), 133-181. https://doi.org/10.4064/fm-3-1-133-181L. B. Ciric, A generalization of Banach's contraction principle, Proc. Amer. Math. Soc. 45, no. 2 (1974), 267-273. https://doi.org/10.2307/2040075H. Garai, L. K. Dey and T. Senapati, On Kannan-type contractive mappings, Numerical Functional Analysis and Optimization 39, no. 13 (2018), 1466-1476. https://doi.org/10.1080/01630563.2018.1485157L. B. Ciric, Generalized contractions and fixed-point theorems, Publ. Inst. Math. 12 (1971), 19-26.Y. U. Gaba and E. Karapinar, A new approach to the interpolative contractions, Axioms 8, no. 4 (2019), 110. https://doi.org/10.3390/axioms8040110E. Karapinar, Revisiting the Kannan type contractions via interpolation. Adv. Theory Nonlinear Anal. Appl. 2, no. 2 (2018), 85-87. https://doi.org/10.31197/atnaa.431135E. Karapinar, R. P. Agarwal and H. Aydi, Interpolative Reich-Rus-Ciric type contractions on partial metric spaces, Mathematics 6, no. 11 (2018), 256. https://doi.org/10.3390/math6110256E. Karapinar, O. Alqahtani and H. Aydi, On interpolative Hardy-Rogers type contractions, Symmetry 11, no. 1 (2018), 8. https://doi.org/10.3390/sym11010008A. F. Roldán López de Hierro, E. Karapinar and A. Fulga, Multiparametric contractions and related Hardy-Roger type fixed point theorems, Mathematics 8, no. 6 (2020), 957. https://doi.org/10.3390/math806095

Sensitivity of Water Dynamics to Biologically Significant Surfaces of Monomeric Insulin: Role of Topology and Electrostatic Interactions

In addition to the biologically active monomer of the protein Insulin circulating in human blood, the molecule also exists in dimeric and hexameric forms that are used as storage. The Insulin monomer contains two distinct surfaces, namely the dimer forming surface (DFS) and the hexamer forming surface (HFS) that are specifically designed to facilitate the formation of the dimer and the hexamer, respectively. In order to characterize the structural and dynamical behaviour of interfacial water molecules near these two surfaces (DFS and HFS), we performed atomistic molecular dynamics simulations of Insulin with explicit water. Dynamical characterization reveals that the structural relaxation of the hydrogen bonds formed between the residues of DFS and the interfacial water molecules is faster than those formed between water and that of the HFS. Furthermore, the residence times of water molecules in the protein hydration layer for both the DFS and HFS are found to be significantly higher than those for some of the other proteins studied so far, such as HP-36 and lysozyme. The surface topography and the arrangement of amino acid residues work together to organize the water molecules in the hydration layer in order to provide them with a preferred orientation. HFS having a large polar solvent accessible surface area and a convex extensive nonpolar region, drives the surrounding water molecules to acquire predominantly a clathrate-like structure. In contrast, near the DFS, the surrounding water molecules acquire an inverted orientation owing to the flat curvature of hydrophobic surface and interrupted hydrophilic residual alignment. We have followed escape trajectory of several such quasi-bound water molecules from both the surfaces and constructed free energy surfaces of these water molecules.These free energy surfaces reveal the differences between the two hydration layers.Comment: 34 pages, 10 figure

Generalized cone b−random metric space with some random fixed point theorems

In this paper, we introduce generalized cone b−random metric space and prove some random fixed point theorems for mappings satisfying various contractive type conditions. Also some stochastic fixed point theorems for integral type contractive mappings have been proved in the above framework.Publisher's Versio

A NEW GENERALIZATION OF M-METRIC SPACE WITH SOME FIXED POINT THEOREMS

In this paper, we introduce a new sequential space as a generalization of M − metricspaces and M b − metric spaces. In this generalized space we define two contractive mappings namely m − contraction and m − quasi-contraction and prove some fixed point theorems for such type of mappings. Several illustrative examples have been presented in strengthening the hypothesis of our theorems

Review on Analysis of Low Pass Finite Impulse Response Filter Using Window functions

Finite impulse response (FIR) filter plays a pivotal role in digital signal processing, multirate signal processing and speech analysis in the communication field. Implementation of the FIR filter employing MATLAB simulation tool can ease the computational complexity and enhance the filter performance to a greater extent. This review paper is based on the analysis of low pass FIR (Finite Impulse Response) filter using different windowing techniques. Rectangular window, Hamming window and Kaiser windows are basically considered for our simulation work . MATLAB programming tools are used to characterize the magnitude and phase response of low pass FIR filter and then analyze the input and output signal in frequency domain as well as time domain for the three window functions under consideration

Hydrochemistry, water quality and land use signatures in an ephemeral tidal river : implications in water management in the southwestern coastal region of Bangladesh

Despite its complexity and importance in managing water resources in populous deltas, especially in tidal areas, literatures on tidal rivers and their land use linkage in connection to water quality and pollution are rare. Such information is of prior need for Integrated Water Resource Management in water scarce and climate change vulnerable regions, such as the southwestern coast of Bangladesh. Using water quality indices and multivariate analysis, we present here the land use signatures of a dying tidal river due to anthropogenic perturbation. Correlation matrix, hierarchical cluster analysis, factor analysis, and bio-geo-chemical fingerprints were used to quantify the hydro-chemical and anthropogenic processes and identify factors influencing the ionic concentrations. The results show remarkable spatial and temporal variations (p <0.05) in water quality parameters. The lowest solute concentrations are observed at the mid reach of the stream where the agricultural and urban wastewater mix. Agricultural sites show higher concentration of DO, Na+ and K+ reflecting the effects of tidal spill-over and shrimp wastewater effluents nearby. Higher level of Salinity, EC, Cl-, HCO3 (-), NO3 (-), PO4 (3-) and TSS characterize the urban sites indicating a signature of land use dominated by direct discharge of household organic waste into the waters. The spatial variation in overall water quality suggests a periodic enhancement of quality especially for irrigation and non-drinking purposes during monsoon and post-monsoon, indicating significant influence of amount of rainfall in the basin. We recommend that, given the recent trend of increasing precipitation and ground water table decrease, such dying tidal river basins may serve as excellent surface water reservoir to supplement quality water supply to the region.Peer reviewe

Environmental study on water quality of Mayur River with reference to suitability for irrigation

ABSTRACT The farmers residing in the western fringe of Khulna city in Bangladesh use the sewage-fed water of the Mayur River for irrigation as good quality surface water is not available as well as higher cost in groundwater irrigation. The present study was undertaken to evaluate the suitability of this river water for irrigation during the hot summer months (March to May) since this period is more sensitive to crop agriculture in the study area. A total of 30 water samples, 10 in each month from 10 stations, were collected and analyzed for pH, EC, TDS, major cations (Na, K, Ca, Mg) and anions (Cl, HCO 3 , NO 3 , PO 4 , SO 4 ), Chemical data were used for calculation of SAR, Na%, RSC, PI, KI and MR for better understanding the suitability of river water for irrigation use. Wilcox diagram and USSL diagram were also adopted in the present study to verify the suitability of river water quality for irrigation. The results revealed that water of the Mayur River was alkaline in nature like major world rivers. Sodium was the most dominant cation throughout the sampling period, whereas sulfate was the most dominat anion in March and May, and chloride in April. The river water was found to be safe for irrigation with respect to pH and PI. However, some usual and calculated parameters like EC, TDS, hardness, alkalinity, chloride, sulfate, nitrate, sodium, Na%, SAR, KI, MR and Ca/Mg restricted the Mayr River water for use in irrigation. The RSC values indicated the water to be safe during April and May and permissible to severe in March. The USSL and Wilcox diagrams indicated high salinity in the water with high sodium being unsuitable for irrigation. The findings call for an immediate management plan to protect this invaluable resource