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The ultrafast monitoring of deoxyribonucleic acid (DNA) dynamic structural changes is an emerging and rapidly growing research topic in biotechnology. The existing optical spectroscopy used to identify different dynamical DNA structures lacks quick response while requiring large consumption of samples and bulky instrumental facilities. It is highly demanded to develop an ultrafast technique that monitors DNA structural changes with the external stimulus or cancer‐related disease scenarios. Here, we demonstrate a novel photonic integrated graphene‐optofluidic device to monitor DNA structural changes with the ultrafast response time. Our approach is featured with an effective and straightforward design of decoding the electronic structure change of graphene induced by its interactions with DNAs in different conformations using ultrafast nanosecond pulse laser and achieving refractive index sensitivity of ~3 × 10−5 RIU. This innovative technique for the first time allows us to perform ultrafast monitoring of the conformational changes of special DNA molecules structures, including G‐quadruplex formation by K+ ions and i‐motif formation by the low pH stimulus. The graphene‐optofluidic device as presented here provides a new class of label‐free, ultrafast, ultrasensitive, compact, and cost‐effective optical biosensors for medical and healthcare applications.

Aflatoxin contamination, particularly common in cultured fishes in Asian countries, are considered unsafe both for fish and human health. However, the presence of aflatoxin in cultured fish feed and their effect are still under estimated in Bangladesh. The present study aimed to assess the effects of aflatoxin on growth performance and residues in tilapia (Oreochromis niloticus) fingerlings. Fish feed were treated with several concentration of aflatoxin as 0 ppb (T0, control), 25 ppb (T1), 50 ppb (T2) and 100 ppb (T3) and fed the tilapia fingerlings (n=10) in individual glass aquaria (24×12×12 inch, 105-litre capacity) conditions for 12 weeks. Comparatively higher body length (cm) and weight gain (g) were observed in treatment T0 (1.68 and 4.98) and T1 (1.60 and 5.48) than those of treatment T2 (1.31 and 4.06) and T3 (1.20 and 3.10), respectively. The specific growth rate (SGR) were almost similar in treatment T0 (52%), T1 (51%) and T2 (52%) whereas declined significantly (p

Kaptai Lake (KL), the largest inland watershed in Bangladesh (ca. 700 km2) and one of Southeast Asia’s largest artificial reservoirs, features an abundant variety of indigenous fishery species. Moreover, it provides a plethora of ecological benefits to society. Nevertheless, the KL is suffering from multidimensional natural and anthropogenic stressors that threaten these wetlands’ sustainability. Though the legal framework assures sustainable conservation of fisheries resources, the implementation scenarios of fisheries laws, regulations, and policies in the KL wetland are insufficient. This study aimed at assessing the fisher’s perception of the regulation implementation efficiency of the Protection and Conservation Fish Act of 1950, while analyzing the effectiveness of the legal framework in the context of biodiversity conservation and the management sustainability of KL. By integrating qualitative and quantitative data collected through participatory Rural Appraisal (PRA) tools viz. 225 interviews with fishers, four focus group discussions, and 12 key informant interviews, the investigation was performed in four selected areas in KL. The findings show that fishers routinely disregard laws and restrictions of the Protection and Conservation of Fish Act 1950 due to various socioeconomic and political forces. Although the annual fish harvest rate from KL appears to be increasing, the lake is losing its charismatic biological diversity primarily due to inappropriate and ineffective enforcement of fishing regulations. Many fishers believe that they still follow the act’s significant laws and regulations while being involved in several destructive and prohibited fishing practices. There is a link between community awareness, the scope of the act’s provisions, the effectiveness of its enforcement, and the strength of its execution. One of the leading causes of biodiversity loss in the KL is inadequate and ineffective fishing regulations. Improvement in the enforcement of the fishing act may be the prominent option to ensure better biodiversity conservation and sustainable management of this wetland. This result calls for functional and policy attention to revising the regulations to account for socioeconomic and political elements contributing to environmental degradation. This study also highlights the urgent need for transdisciplinary collaboration initiatives and synchronous cooperation among the agencies in order to effectively implement the fishing laws and contribute to better conservation and sustainability of the Kaptai lake fisheries resources.

Fisheries and the aquaculture sector can play a significant role in the achievement of several of the goals of the 2030 Sustainable Development agenda. However, the current COVID-19 situation can negatively impact the fisheries sector, impeding the pace of the achievement of development goals. Therefore, this paper highlighted the performance and challenges of the fisheries sector in Bangladesh, emphasising the impact of COVID-19 and the significance of this sector for achieving the Sustainable Development Goals (SDGs), through primary fieldwork and secondary data. The total fish production in the country has increased more than six times over the last three decades (7.54 to 43.84 lakh MT) with improved culture techniques and extension services. Inland closed water contributions have increased to 16%, while inland open water has declined to 10%, and marine fisheries have dropped to 6% over the past 18 financial years (2000–2001 to 2018–2019). COVID-19, a significant health crisis, has also affected various issues associated with aquatic resources and communities. Transportation obstacles and complexity in the food supply, difficulty in starting production, labour crisis, sudden illness, insufficient consumer demand, commodity price hikes, creditor’s pressure, and reduced income were identified as COVID-19 drivers affecting the fisheries sector. The combined effect of these drivers poses a significant threat to a number of the SDGs, such as income (SDG1), nutrition (SDG2), and food security (SDG3 and SDG12), which require immediate and comprehensive action. Several recommendations were discussed, the implementation of which are important to the achievement of the SDGs and the improved management of the aquatic sector (SDG14—life below, and SDG16—life above water).

Tanguar Haor (TH) is considered one of the Ecologically Critical Areas (ECAs) of Bangladesh and is internationally recognized as RAMSAR wetland (2nd Ramsar site) known to provide multiple ecosystem services to the society. Nevertheless, multidimensional threats and stressors, the capacity to supply ESs, and the biodiversity of the TH significantly degrades and threatens this wetland’s conservation and sustainability. Although the legal framework promises the sustainable conservation of fisheries resources, information on the implementation scenarios of fisheries laws, regulations, and policies in the TH Ramsar are scant. By merging qualitative and quantitative data of primary and secondary sources, this research aimed to analyze the legal framework to check the effectiveness of regulations for non-conflicting fisheries resources and the sustainable conservation of the TH Ramsar. Primary empirical data were collected by employing Participatory Rural Appraisal (PRA) tools, i.e., 204 semi-structured questionnaire-based individual interviews with fishers, three focus group discussions, and 14 key informants’ interviews in three fishing villages in the TH. In contrast, secondary data was set by reviewing published literature and related official documents. Results showed that, due to weak enforcement with inadequate surveillance and poor implementation of the legal framework, there was a high non-compliance with fishing laws, rules, and policies. Destructive and prohibited fishing gears, e.g., the use of small mesh fine nylon nets (current jal), purse seine net (ber jal), and the harvesting during ban period-illicit catch were widespread in the study areas. In addition, catching undersized fish, fishing at the restricted areas (sanctuary area), and fishing during spawning seasons occur often. There is a crying need for a comprehensive legal and policy framework to contextualize the local context, ensure the proper implementation of the fishing laws and regulations, increase the managerial inefficiency of enforcing agencies, ensure livelihood support during the fishing ban, and afford good alternative income options are still significant issues for good governance in the Tanguar Haor ECA. Findings might help to identify the gaps and misunderstanding of the existing legal practice while submitting urgent attention to the need for drawing a comprehensive legal and policy framework (contextually modified according to the local context), taking initiatives and acting synchronously for proper implementation, and calling transdisciplinary collaboration and cooperation among the agencies that may ensure the non-conflicting use of the natural resources of the TH that can be also helpful for the better conservation of this Ramsar wetland.

The Meghna river estuary has had substantial importance in supporting the coastal community’s livelihood for decades, but the pressure on it is immense due to many anthropogenic drivers. The present study aimed to assess its ecosystem services (ES) according to the framework of the standard international classification of ecosystem services (CICES). This study also identified the drivers, pressure, state, impact, and responses (DPSIR), and the factors responsible for ES changes in the Meghna river estuarine ecosystems. By merging both quantitative and qualitative data, a total of 19 sub-categories of ES were found, among which eight are provisioning, seven are regulatory, and four are cultural services, according to the CICES framework. From the results, it can be concluded that food provisioning from the Hilsha fishery, the national fish as a part of cultural heritage, and nursery habitat functions were the top provisional, regulatory, and cultural services to the society in the study areas and beyond. However, several threats and stressors of both anthropogenic and natural origins were identified as drivers of ES changes, such as overexploitation, destructive and illegal fishing, heavy river bed siltation, and natural hazards such as extreme cyclonic events, floods, and sea levels rising. This study underlines the urgency of research and policy attention to address the challenges, and of transforming management regimes to an ecosystem-based approach, which is part of nature-based solutions according to the International Union for Conservation of Nature (IUCN), which refers to the present case, and particularly to fishery co-management. Creating alternative income sources and raising community awareness regarding the importance of maintaining the healthy condition of the river basins, and comprehensive compliance with the rules and regulations are proposed in order to ensure these estuarine ecosystems’ sustainability.

By employing empirical and secondary data (qualitative and quantitative), this study demonstrates how social equity (with its three dimensions) can meaningfully address the conservation of the coastal social&ndash, ecological system (SES), without losing diverse ecosystem services (ES) in south-east coastal Bangladesh. Based on this proposition, this study assesses the available ES and identifies the drivers responsible for ES changes, arguing for the application of social equity for resource conservation. The findings show that communities along Bangladesh&rsquo, s south-eastern coast use several ES for food, medicine, income, livelihoods, and cultural heritage. However, this valuable ecosystem is currently experiencing numerous threats and stressors of anthropogenic and natural origin. In particular, large-scale development activities, driven by the blue growth agenda, and neoliberalism policy, pose a risk to the local communities by degrading coastal ecosystem services. Escaping this situation for coastal natural resource-dependent communities in Bangladesh will require a transformation in the governance structure. Implementing the Small-Scale Fisheries (SSF) Guidelines that call for initiating policy change to deliver social justice to small-scale fisheries would help to address coastal ecosystem service conservation in Bangladesh.

The present study was conducted to determine the persistence of oxytetracycline residue in Tilapia (Oreochromis niloticus) available in local fish markets of Sylhet Sadar Upazila. To carry out this experiment, 24 fish samples were randomly collected from four (4) local fish markets under study area from March 2016 to August 2016. Fish samples were analyzed by using High Performance Liquid Chromatography (HPLC) method to detect amount of residues of oxytetracycline. In this study, detectable oxytetracycline residues were observed in five (5) samples of Tilapia ranged between 23.77-39.94 ppb (mean 38.88±2.99 ppb). Oxytetracycline residues less than limit of detection were also found in 19 (79.17%) samples. The detected residues of oxytetracycline in these fish samples did not exceed the maximum residue limit (MRL) 100 ppb recommended by the European Commission. However, long term persistence of high level oxytetracyclines could be a potential hazardous for public health. For this reason supervision of antibiotic uses and monitoring of optimum MRL in Tilapia are utmost needed for farmed fish species.Bangladesh J. Sci. Ind. Res.53(1), 41-46, 2018

The south-east coast, specifically the Cox’s Bazar region, of Bangladesh has achieved a tremendous impetus for producing a large volume of dried fish by involving thousands of marginalized coastal people. This study aimed to assess the socio-economic profile, livelihood strategies, and resilience of the communities engaged in fish drying on the south-east coast using a mixed-methods approach and an Analytic Hierarchy Process (AHP). The study’s findings revealed that communities involved in drying were socio-economically undeveloped due to their lower literacy, unstable incomes, and labor-intensive occupations. Apart from notable child labor employed in fish drying in Nazirertek, female workers had relatively higher participation than males. Nevertheless, the female workers had less control over their daily wages and reported working at USD 3.54–5.89 per day, which was relatively lower than male workers who received USD 4.15–8.31 per day. Through fish drying activities, very few workers, producers, and traders were found to be self-reliant. In contrast, the livelihoods of the workers were not as secure as the processors and traders. In addition to suffering from various shocks and constraints, dried fish processors and workers, dried fish traders, off-season income, an abundance of fish species, fish drying facilities, trader’s association, and social interrelationship played a significant role in maintaining community resilience. The study recommends appropriate interventions to alternative income diversification options, strong collaboration between communities, local authorities, and government for sustainable livelihoods and better community resilience.

Biodiesel, which comprises of fatty acid esters, is an alternative fuel for diesel engines. However, biodiesel has poorer cold flow properties (CFPs; i.e., cloud point (CP), cold filter plugging point (CFPP), and pour point (PP)) than diesel fuel. This study aims to reduce the PP, CFPP, and CP of two different biodiesels, namely, Cocos nucifera (coconut) and Calophyllum inophyllum (C. inophyllum), using polymethyl acrylate (PMA) additives. This study also investigates the effect of PMA on other biodiesel properties. Various physicochemical properties were measured and compared with the ASTM D6751 and EN14214 standards. Differential scanning calorimetry was used to observe the crystal behavior of the biodiesel blends. Results showed that 20% of biodiesel blended with diesel (B20) and 0.03 wt% of PMA showed the highest improvement in the CP, PP, and CFPP. This study also investigates the influence of PMA on oxidation stability, flash point, heating value, and kinematic viscosity. These properties of B20 satisfy the ASTM D6751 and EN14214 standards. The process of crystal aggrandizement and the rate of wax crystal precipitation of B20 can be modified by PMA, resulting in enhanced CFPs of the biodiesel blend. Therefore, PMA is an effective cold-flow-improving additive for coconut-based and C. inophyllum-based biodiesel blends. Moreover, the results indicated that 20% coconut and C. inophyllum biodiesel blends with 0.03 wt% of PMA can be used in cold climate areas without any problem in terms of fuel physicochemical quality.

The health conditions of freshwater mud eel, Monopterus cuchia of Ailee beel, Mymensingh district was investigated through clinical and histopathological observations from September 2005 to March 2006. Monthly sampling of water quality parameters like temperature, dissolved oxygen, pH and total hardness were carried out. Water temperature and total hardness were at reduced level for fish during the months of November to January in the beel. Clinically weak body, rough skin, deep ulcer and grey brownish colour of the body were noticed especially from November to January. Major pathology in the skin and muscle such as loss of epidermis and dermis, necrosis of myotoms, huge vacuum spaces, marked melanomacrophage and fungal granuloma were found in December and January. Marked melanomacrophages, severe haemorrhage, vaccums, hepatic necrosis, fat droplets were found in the liver. In kidney numerous haemorrhagic areas, necrosis, few fat droplets and many fungal granulomas were seen in December and January. Histopathologically, sampled fishes were found normal in September and October and reduced pathological signs were observed in February and March. Clinically and pathologically eels were found to be more affected in December and January. Reduced temperature and total hardness might have played role in the occurrence of clinical and pathological changes in fish during the period. The fishes were affected by EUS, with the evidence of development of fungal granuloma in skin, muscle and kidney. Keywords: Health; Freshwater eel; Disease; Ailee beel DOI: 10.3329/jbau.v7i2.4755 J. Bangladesh Agril. Univ. 7(2): 421-426, 2009