Influence of mangrove forests on subjective and psychological wellbeing of coastal communities: Case studies in Malaysia and Indonesia.

Mangrove forests possess multiple functions for the environment and society through their valuable ecosystem services. Along with this, the mangrove forests have large and diverse social values, in combination contributing to the health and wellbeing of the surrounding communities. This study aims (i) to assess the benefits of mangrove forests and their impact on subjective and psychological wellbeing of coastal communities and (ii) to understand the challenges coastal communities face that limit sustainable wellbeing. We have used a mixed methodological approach, combining workshop, interview, and survey, to obtain qualitative and quantitative information from two coastal communities in Malaysia and Indonesia. For quantitative data, 67 participants from both coastal communities participated using a pre-tested structured questionnaire. To obtain opinions from key informants in Malaysia and Indonesia, we organized two stakeholders' workshops and community interviews. When merging these interviews and workshops, we identified the following three themes related to the perception of mangrove forest benefits: (1) the advantage of living in a natural countryside; (2) the natural resources supporting employment, income, and family security; and (3) the increase in subjective and psychological wellbeing. The mean score of wellbeing for Indonesian participants (28.6) was slightly higher than that for Malaysian participants (26.2) and was significant. Overall, the respondents felt happy because the combination of job security and leisure activities supports feeling content and satisfied. The analyses also suggest that the combination of exposure to coastal environments and stress reduction promotes good mental health; however, diagnostic health data are lacking. The lower score of mental wellbeing in Malaysia is attributed to respondents involved in risky fishing activities and local regions with excessive tourism. The findings from this study imply that coastal mangrove forest management plays an important role in the living conditions of coastal communities and their subjective and psychological wellbeing. Hence, restoration and sustainability of mangrove ecosystem are important.

Hydrothermal synthesis of PVP-passivated clove bud-derived carbon dots for antioxidant, catalysis, and cellular imaging applications.

In recent times, carbon dots (CDs) are emerging for numerous interdisciplinary applications by modulating their inherent chemical functionality during or post-synthesis modification. The current study reports the hydrothermal synthesis of polyvinylpyrrolidone K-30 (PVP) passivated clove bud-derived carbon dots (PPCCDs) for multifaceted applications. The adopted technique is facile and environmentally friendly for the production of CDs with in situ PVP passivation. Physicochemical characterization of CDs is performed using various spectroscopic and microscopic techniques. The study reveals the formation of nitrogen-doped spherical PPCCDs with an average hydrodynamic size of ∼ 4.9 nm. It is also evident that there is modulation in optical properties and quantum efficiency as a result of PVP passivation. The study further demonstrates their suitability in biological environments as observed by pH stability, photostability, and cytocompatibility results. PPCCDs have shown significant antioxidant activity against DPPH (EC50: 57 µg/mL), suppression of superoxide anion radical (EC50: 53 µg/mL), and an efficient catalytic activity towards degradation of Rhodamine-B (Rh-B) dye. UV-Visible spectroscopy unveil the reaction mechanism during antioxidant and catalytic activities of CDs that are validated by Electron paramagnetic resonance (EPR) spectroscopy with an indication of effective electron or proton donating abilities. Its bioimaging potential is evidenced through cellular fluorescence imaging with 3T3 and L929 cell lines.

Drinking water quality of Chattogram city in Bangladesh: An analytical and residents' perception study.

Residents of Chattogram city areas in Bangladesh use drinking water from three sources, namely CWASA (Chattogram Water supply and Sewerage Authority), groundwater (tube-well), and commercial jar. In this study, we examined the quality of drinking water from these sources following an analytical and residents' perception. Water samples (both untreated and treated) from above three sources were collected from six locations across Chattogram city, and pH, total dissolved solids (TDS), total suspended solids (TSS), bicarbonate, electrical conductivity (EC), salinity, and microbial load were studied following the state-of-art testing methods. A total of 149 respondents were interviewed to understand their perception on the physical properties of water. The pH value of water from all sources and locations and irrespective of treatments, varied from 6.54 to 7.02. TDS of tube-well water in two locations exceeded the standard limit (1000 mg/l). In most locations, TSS varied from 40 to 1888 mg/l (treated and untreated) against the standard value of 10 mg/l, while bicarbonate of CWASA and tube-well water in most locations was also higher than the permissible amount (500 mg/l). Except for jar water, EC of CWASA and tube-well water (treated and untreated) in most locations were higher than the standard value (500 µS) and a similar situation was observed for salinity content. The microbial load was found beyond the permissible limit (0 CFU/ml) for all sources and locations. These parameters of water quality have also been reflected in residents' perceptions of drinking water. Respondents reported an unpleasant odour (56%), the presence of suspended particles (17%), and so CWASA water is not good for drinking (76%). Authorities (CWASA) need to take action toward a safe drinking water supply for residents.

Capacity development and safety measures for health care workers exposed to COVID-19 in Bangladesh.

BACKGROUND: The safety of health care workers (HCWs) in Bangladesh and the factors associated with getting COVID-19 have been infrequently studied. The aim of this study was to address this gap by assessing the capacity development and safety measures of HCWs in Bangladesh who have been exposed to COVID-19 and by identifying the factors associated with respondents' self-reported participation in capacity development trainings and their safety practices. METHODS: This cross-sectional study was based on an online survey of 811 HCWs working at 39 dedicated COVID-19 hospitals in Bangladesh. A pretested structured questionnaire consisting of questions related to respondents' characteristics, capacity development trainings and safety measures was administered. Binary logistic regressions were run to assess the association between explanatory and dependent variables. RESULTS: Among the respondents, 58.1% had been engaged for at least 2 months in COVID-19 care, with 56.5% of them attending capacity development training on the use of personal protective equipment (PPE), 44.1% attending training on hand hygiene, and 35% attending training on respiratory hygiene and cough etiquette. Only 18.1% reported having read COVID-19-related guidelines. Approximately 50% of the respondents claimed that there was an inadequate supply of PPE for hospitals and HCWs. Almost 60% of the respondents feared a high possibility of becoming COVID-19-positive. Compared to physicians, support staff [odds ratio (OR) 4.37, 95% confidence interval (CI) 2.25-8.51] and medical technologists (OR 8.77, 95% CI 3.14-24.47) were more exhausted from working in COVID-19 care. Respondents with longer duty rosters were more exhausted, and those who were still receiving infection prevention and control (IPC) trainings were less exhausted (OR 0.54, 95% CI 0.34-0.86). Those who read COVID-19 guidelines perceived a lower risk of being infected by COVID-19 (OR 0.44, 95% CI 0.29-0.67). Compared to the respondents who strongly agreed that hospitals had a sufficient supply of PPE, others who disagreed (OR 2.68, 95% CI 1.31-5.51) and strongly disagreed (OR 5.05, 95% CI 2.15-11.89) had a higher apprehension of infection by COVID-19. CONCLUSION: The findings indicated a need for necessary support, including continuous training, a reasonable duty roster, timely diagnosis of patients, and an adequate supply of quality PPE.

Peoples' understanding, acceptance, and perceived challenges of vaccination against COVID-19: A cross-sectional study in Bangladesh.

In order to eliminate COVID-19, many countries provided vaccinations. However, success depends on peoples' knowledge levels and rates of acceptance. But, previous research on this topic is currently lacking in Bangladesh. This cross-sectional study aimed at to investigate Bangladeshi peoples' knowledge, acceptance, and perception of challenges regarding COVID-19 vaccines. Quantitative data were collected using an online survey (n = 1975) and face-to-face interviews (n = 2200) with a pre-tested structured questionnaire. In addition, seven open-ended interviews were conducted with health experts regarding challenges of vaccination. Binary logistic regression analyses were conducted to assess the association between explanatory and dependent variables. Effect size was estimated to understand the magnitude of relationship between two variables. Of 4175 respondents, 92.6% knew about COVID-19 vaccines, while only 37.4% believed vaccines to be effective in controlling COVID-19. Nearly 46% of respondents believed that COVID-19 vaccines have side-effects, and 16.4% of respondents believed that side-effects could be life-threatening. Only 60.5% of respondents indicated that they would receive the COVID-19 vaccine. Out of 1650 respondents (39.5%) who did not intend to receive the vaccine, 948 (57.4%) believed that they would be naturally protected. Regressions results indicated that men had higher rates of knowledge regarding the vaccine. In addition, rural respondents demonstrated lower knowledge regarding the vaccine. Furthermore, education had a significant association with knowledge of COVID-19 vaccines. Respondents with university education had more knowledge regarding the vaccine (Odds ratio, OR = 29.99; 95% confidence interval, CI 11.40-78.90, effect size 1.88; p = 0.01) and correct dosage (OR 27.34; 95% CI 15.25-49.00, effect size 1.83; p = 0.01). However, women (OR 1.16; 95% CI 0.96-1.40, effect size 0.08) and rural (OR 1.24; 95% CI 1.07-1.44, effect size 0.12; p = 0.01) respondents were more enthusiastic regarding receiving the COVID-19 vaccine. Higher educated respondents showed higher probability of receiving the vaccine. Those who believed in the effectiveness of the COVID-19 vaccine were 11.57 times more interested (OR 11.57; 95% CI 8.92-15.01, effect size 1.35; p = 0.01) in receiving the vaccine. Open-ended interviews identified several challenges toward successful COVID-19 vaccination. Mass awareness creation, uninterrupted supply, equitable distribution, and sectoral coordination were suggested to achieve at least 70% immunization across the country.

Tuning of structural and optical properties with enhanced catalytic activity in chemically synthesized Co-doped MoS2 nanosheets.

Molybdenum disulfide (MoS2) nanosheets, due to having a highly active nature, being low cost and having unique physical and chemical properties, have shown their efficacy in the catalytic reduction of nitroarenes. Doping of transition metal ions in molybdenum disulfide (MoS2) nanosheets is a well-known strategy to enhance their catalytic efficiency for the reduction of nitroarenes, however, finding the optimum dopant amount is still a subject of ongoing research. Herein, we have synthesized few-layered cobalt (Co) doped MoS2 nanosheets with different cobalt content (2%, 4%, 6% and 8%) through the solvothermal approach, taking sodium molybdate dihydrate (Na2MoO4·2H2O), thiourea (CH4N2S) and cobalt acetate tetrahydrate [Co(CH3COO)2·4H2O] as precursors and their catalytic performance has been affirmed by monitoring the reduction of p-nitrophenol by NaBH4 in real time using UV-visible absorption spectroscopy. The 6% Co doped MoS2 nanosheets have exhibited superior catalytic activity with a pseudo-first order rate constant of 3.03 × 10-3 s-1 attributed to the abundant defects in the active edge sites having a dominant metallic 1T phase with Co ion activated defective basal planes, sulphur (S) edges, synergistic structural and electronic modulation between MoS2 and Co ions and enhanced electron transfer assisted through redox cycling in the active sites. An attempt has also been made to study the manipulation of structural and optical properties with cobalt doping in MoS2 nanosheets to establish a correlation between the catalytic efficiency and dopant content. This study demonstrates that proper tuning of Co doping in MoS2 nanosheets paves the way in searching for a potential alternative of a noble metal catalyst for the catalytic reduction of nitroarenes.

Psychological and Livelihood Impacts of COVID-19 on Bangladeshi Lower Income People.

The objective of this research is to understand the psychological and livelihood-related impacts of coronavirus disease 2019 (COVID-19) on Bangladeshi lower income group people who depend on daily earnings for their living. Following the convenience sampling method, 576 respondents were interviewed for quantitative data and 30 in-depth interviews for qualitative information in several districts of Bangladesh. To 94.1% respondents, livelihood has been affected by the COVID-19 outbreak with an overall score of 3.20 ± 0.77 on a 4-point Likert-type scale. In comparison to unemployed respondents, daily workers have been hardly affected by the COVID-19 outbreak (odds ratio [OR] = 7.957; P < .01), and so they are going outside more frequently in search of jobs (OR = 9.984, P < .01). Due to fear of COVID-19 infection and lack of livelihood means, respondents (76.6%) have been stressed out (overall score 3.19 ± 0.81 on a 4-point Likert-type scale), and those working in industries (OR = 5.818, P < .01), farmers (OR = 3.029, P < .05), and day laborers (OR = 2.651, P < .05) have been highly stressed.

The effect of Ca-bearing contents in chitosan on Pb 2+, Cd 2+ and Cu 2+ adsorption and its adsorption mechanism.

The preparation of chitosan has been investigated for more than half century; however, the application of chitosan for heavy metal (HM) adsorption is still under research. This study investigated the effects of chitosan with chemically controlled Ca-bearing contents (CBC) on Pb2+, Cd2+ and Cu2+ adsorption in the solution with the initial pH values of 2.10, 4.14 and 6.13. Highly purified chitosan showed the optimum HM adsorption at the initial pH values of 4.14 and 6.13, and the adsorption mechanism was chemisorption involving valence forces through sharing or exchange of electrons between the chitosan and HM ions. Highly purified chitosan prepared from HCl treated chitin only showed effective for Pb2+, however, those prepared from CH3COOH treated chitin showed effective for Pb2+, Cd2+ and Cu2+ adsorption due to a little amount of CBC. The HM adsorption mechanisms of partly purified chitosan were precipitation due to CBC and biosorption. Chitosan with 73% CBC showed the optimum adsorption of Pb2+ (755 mg/g) at an initial pH value of 2.10 while Cd2+ (979 mg/g) and Cu2+ (877 mg/g) at the initial pH values of 4.14 and 6.13. High Ca(OH)2-bearing chitosan prepared from HCl and H2SO4 treated chtin showed the optimum Cd2+ (978 mg/g) and Cu2+ (852 mg/g) adsorption at an initial pH value of 2.10. Biosorption isotherm and kinetics models showed that the adsorption data of Pb2+, Cd2+ and Cu2+ onto the surface of chitosan was well-fitted by Langmuir model and Pseudo-second-order model with correlation coefficient (R2 > 0.95 and R2 > 0.91, respectively). Pseudo-second-order model showed that the adsorption capacity strongly depended on CBC in chitosan and initial pH value of HM solution. It is concluded that the HM adsorption by the prepared chitosan is a chemical process that was supported by CBC of chitosan through elevating solution pH value.

Knowledge, attitudes, and practices toward the novel coronavirus among Bangladeshis: Implications for mitigation measures.

The current novel coronavirus (nCoV) pandemic, COVID-19, was first reported in December 2019 in Wuhan, China, and has spread globally, causing startling loss of life, stalling the global economy, and disrupting social life. One of the challenges to contain COVID-19 is convincing people to adopt personal hygiene, social distancing, and self-quarantine practices that are related to knowledge, attitudes, and practices (KAP) of the residents of respective countries. Bangladesh, a densely populated country with a fast-growing economy and moderate literacy rate, has shown many hiccups in its efforts to implement COVID-19 policies. Understanding KAP may help policy makers produce informed decisions. This study assessed KAP in relation to COVID-19 in Bangladesh. An online survey using a pre-tested questionnaire conducted in late March 2020 attained 1,837 responses across Bangladesh. Ultimately, 1,589 completed responses were included in a statistical analysis to calculate KAP scores and their interrelations with sociodemographic variables. The overall KAP was poor, with only 33% of the participants demonstrating good knowledge, whereas 52.4% and 44.8% of the subjects showed good attitudes and practices, respectively. Sociodemographic factors had strong bearings on the KAP scores. Significantly higher KAP scores were evident in females over males, among aged 45 years and older over younger participants, and among retired workers and homemakers over students and public service employees. This study indicated a panic fuelled by poor understanding of COVID-19 associated facts and the need for the government to ensure more granular and targeted awareness campaigns in a transparent and factual manner to foster public confidence and ensure more meaningful public participation in mitigation measures. This study provides a KAP baseline regarding COVID-19 among Bangladeshis.

Suppression of charge and antiferromagnetic ordering in La0.5Ca0.5MnO3 nanoparticles.

The intermediate band-width manganite La0.5Ca0.5MnO3 has a CE type charge, orbital and antiferromagnetic order below 195 K owing to strong electronic correlation and commensurability effect. We have critically investigated in details all the possible mechanisms behind the destabilization of charge/orbital ordering in La0.5Ca0.5MnO3 with the reduction of grain size in the nanometric regime as evidenced from our various experimental results. We have tried to found out a universal scenario to explain such behavior in nanometric manganites in general. This study shows that the room temperature Pnma perovskite structure, correlated with the lattice distortion, Mn-O distances and octahedral tilts, is practically unaffected with the reduction of particle size. However, in these nanocrystalline La0.5Ca0.5MnO3, the stable charge ordered state with antiferromagnetic ordering becomes significantly suppressed and FM ordering spontaneously appears below T(c) = 260 K as compared to its bulk counterpart. From strong experimental evidences on nano and bulk manganites, we revisit this issue and also discuss the absence of correlation between size reduction and pressure effects on manganites. We argue from a phenomenological analysis that the above observations could be best attributed to enhanced surface disorder in the nanosized half-doped manganite grains which is likely to be general in all nano size charge ordered manganites.