Quantification, characterization and risk assessment of microplastics from five major estuaries along the northern Bay of Bengal coast

Microplastics (MPs) as hazardous contaminants has drawn the rapid attention of the general public due to their omnipresence and adverse impacts on ecosystems and human health. Despite this, understanding of MPs contamination levels in the estuarine ecosystems along the Bay of Bengal coast remains very limited. This research focused on the presence, spatial distribution, morpho-chemical characteristics and ecological implications of MPs in water and sediment from five key estuaries (Meghna, Karnaphuli, Matamuhuri, Bakkhali, and Naf rivers) within the Bengal delta. Out of the five estuaries, the Meghna exhibited the least amount of MPs in both surface water (150.00 ± 65.62 items/m3) and sediment (30.56 ± 9.34 items/kg). In contrast, the highest occurrence of MPs was recorded in Karnaphuli river water (350.00 ± 69.22 items/m3) and Matamuhuri river sediment (118.33 ± 26.81 items/kg). ANOVA indicated a statistically significant distinction (p < 0.01) among the examined estuaries. Most identified MPs were fibers and < 0.5 mm in size in both water and sediment samples. Transparent MPs were dominant in both water (42.28%) and sediment (45.22%). Besides violet, red, blue, pink and green colored MPs were also observed. Various polymer types, including PE, PP, PET, PS, Nylon, EVA, and ABS, were detected, with PE being the dominant one. Based on the polymer risk index (PHI), the estuaries were classified as hazard level V, signifying a severe level of MP contamination. However, the potential ecological hazardous index (PHI), potential ecological risk index (RI), and pollution load index (PLI) indicated moderate pollution levels. This study offers initial insights into the pollution caused by MPs in major estuaries of Bengal delta, which policymakers can utilize to implement suitable management strategies.

Vertical distribution, contamination status and ecological risk assessment of heavy metals in core sediments from a mangrove-dominated tropical river

Understanding the vertical distribution of heavy metals aids in tracing the contamination history, however, it is limited for mangrove-dominated river. Thus, this study aimed to assess the vertical distribution of nine heavy metals and their possible ecological risk in several layers of core sediments from a mangrove-dominated river inside the Sundarban mangrove forest (World heritage and Ramsar site), Bangladesh. 45 core samples from five stations were analyzed using Flame Atomic Absorption Spectrophotometer (FAAS). The findings showed that, with the exception of Fe, Ni, and Cu, which suggested increased metal release in recent times, higher metal levels were recorded in the surface layer (0-10 cm), followed by the middle layer (10-20 cm), and inner layer (20-30 cm) of sediment cores. When compared to non-industrial forest sediment, core sediment from industrial sites contained noticeably more metals (p < 0.05). Overall, the mean metal concentration (mg/kg) followed the increasing order of Cd < As < Pb < Cu < Cr < Zn < Ni < Mn < Fe. Among the studied metals, the levels of Cd and Ni exceeded the average shale value. Contamination indices such as enrichment factor (EF), contamination factor (CF), and geo-accumulation index (I_geo) showed that the studied sediments were only contaminated by Cd. Ecological risk assessed by ecological risk factor (E_rⁱ) and risk index (RI) suggested that the analyzed heavy metals, with the exception of Cd, posed no significant ecological threats. All of the heavy metals analyzed might have originated from similar anthropogenic sources, according to the correlation matrix, cluster analysis (CA), and principal component analysis (PCA).

Global geographical discrepancy in numerical distribution of cardiovascular surgeries and human resource development in South Asia

Objective

The region South Asia is in the south-central part of the Asian continent. The 8 countries of the area, Afghanistan, Bangladesh, Bhutan, India, Nepal, The Maldives, Pakistan, and Sri Lanka collectively possess 1.8 billion people living in 5.1 million square miles. Covering 2.96% of World's surface, this area is inhabited by 23.9% of the world population. The objective of this study was to observe the number of cardiac operations in South Asia and the human resource development facilities of cardiac surgery in the region.

Methods

Information was collected from the surgeons and anesthetists through personal visits, phone calls, and emails. The websites of various organizations were also checked.

Results

The estimated number of cardiac operations collectively performed in the South Asian countries was between 250,000 and 300,000 as of 2019. With more than 6 times the US population, these nations combined performed less than half of the annual number of cardiac operations performed in the United States. The number of operations per million population ranged from 62 to 271 in different countries. This indicates that there should be more capacity-building of surgeons to meet the growing demand of operations. India, Pakistan, Bangladesh, Sri Lanka, and Nepal have their own education and training systems for cardiovascular surgeons. A substantial portion of the seats available for cardiovascular surgery courses remained vacant in South Asia these days.

Conclusions

Five countries have their various surgical education and training programs. There should be coordinated efforts to increase the production of new cardiac surgeons in the region.

Antidiarrheal, Analgesic, and Anthelmintic Activities of Honeys in the Sundarbans Mangrove Forest, Bangladesh

This study evaluated the antidiarrheal, analgesic, and anthelmintic activities of honey samples from the Sundarbans mangrove forest of Bangladesh. Composite raw honey (RH), and its diethyl ether (DEH), ethanol (ETH), methanol (MEH), and distilled water (DWH) fractions were investigated. RH and its fractions strongly inhibited castor oil-induced diarrheal episodes in mice at a concentration of 250 mg/kg body weight (b.w.) (P<0.05). At this concentration, RH, DEH, ETH, MEH, and DWH showed inhibitory activity on diarrheal episodes at 43.8, 47.4, 29.8, 12.3, and 38.5%, respectively, whereas for the inhibitory activity for the positive control (PC, 3 mg loperamide/kg b.w.) was 47.4%. Similarly, DEH (250 mg/kg b.w.) showed strongest inhibition (63.5%) of acetic acid-induced writhing in mice, followed by RH (55.7%), ETH (46.2%), MEH (37.6%), and DWH (32.9%). In a hot plate test, mice treated with DEH at a concentration 250 mg/kg b.w. showed the greatest increase in response time, followed by treatment with RH. RH was further used in an anthelmintic test, where it showed a strong dose-dependent reduction in both the paralysis time and the time until death of the parasite, Paramphistomum cervi. Honeys in the Sundarbans could therefore be of great use as nutraceuticals.

Mapping and validation of QTLs for cold tolerance at seedling stage in rice from an indica cultivar Habiganj Boro VI (Hbj.BVI)

Yellowing, stunting, and seedling death associated with cold stress is a common problem in many Asian countries for winter rice cultivation. Improvement of cultivars through marker-assisted selection of QTLs for cold tolerance at seedling stage from locally adapted germplasm/cultivar is the most effective and sustainable strategy to resolve this problem. A study was undertaken to map QTLs from 151 F2:3 progenies of a cross between a cold susceptible variety, BR1 and a locally adapted traditional indica cultivar, Hbj.BVI. A total of six significant QTLs were identified for two cold tolerance indices-cold-induced leaf discoloration and survival rate after a recovery period of seven days on chromosomes 6, 8, 11, and 12. Among these QTLs, qCTSL-8-1 and qCTSS-8-1 being co-localized into RM7027-RM339 on chromosome 8 and qCTSL-12-1 and qCTSS-12-1 into RM247-RM2529 on chromosome 12 showed 12.78 and 14.96% contribution, respectively, to the total phenotypic variation for cold tolerance. Validation of QTL effect in BC1F3 population derived a cross between a cold susceptible BRRI dhan28 and Hbj.BVI showed dominating effect of qCTSL-12-1 on cold tolerance at seedling stage and it became stronger when one or more other QTLs were co-segregated with it. These results suggest that the QTLs identified in this study are stable and effective on other genetic background also, which warrant the use of these QTLs for further study aiming to cultivar development for seedling stage cold tolerance.

Knowledge and attitude towards voluntary blood donation among Dhaka University students in Bangladesh

This cross sectional descriptive study was conducted among the students of the University of Dhaka, Bangladesh, to assess their knowledge and attitudinal variables towards voluntary, non-remunerated blood donation. Two hundred students were selected to participate in this study and were interviewed face to face on various aspects of blood donation using a structured questionnaire. Eighty two per cent of the participants showed a positive attitude towards blood donation, however, only 16 per cent of the respondents in this study had actually ever donated blood voluntarily. Among the non-donor respondents, physical harm and fear were found to be the common reasons for not donating blood. The results also showed that a high number of respondents (93%) had a negative attitude towards paid blood donation. We suggest that appropriate motivational campaign should be launched immediately among this young section of the population to convert this favourable "attitude" towards blood donation into a regular "practice" in order to increase the voluntary blood donation in Bangladesh.

Use of four types of litter for rearing broilers

1. One hundred and forty four Shaver broiler chicks (Starbro 15) were reared from 4 d to 56 d of age on 4 types of litter: sawdust, paddy straw, sand and rice husk each spread to a depth of 75 mm. 2. Birds reared on rice husk litter showed the greatest food consumption, greatest weight gain, best food conversion efficiency and scored highest in production number. 3. Survivability was also highest with rice husk group (94.4%) but differences in this variable were not thought to be attributable to types of litter. 4. Breast blisters were found only in birds reared on sand (8.3%). 5. It was concluded that rice husk is a suitable litter for rearing broilers on the floor, particularly in paddy-growing countries.