Evaluation of microbiological quality of dried baim (Mastacembelus armatus) in Bangladesh

A study was performed for five months to assess the microbiological quality of dried Baim (Mastacembelus armatus) in Sylhet region of Bangladesh. A total of 45 dried samples were randomly collected on monthly basis from three different sources of Sylhet region; one from producer (drying yard of Lamagaji) and others from retail market (Bandar Bazar) and control (prepared in laboratory). The mean total plate count (TPC) of dried Baim from producer, retail market and control were observed 6.20 ± 0.72 ×105, 9.64 ± 1.58 ×105 and 1.61 ± 1.06×105 cfu/g, respectively, whereas, average total fungal count (TFC) were estimated 3.77 ± 0.81 ×103, 4.65 ± 1.08 ×103 and 1.78 ± 0.64 ×103 cfu/g, respectively. TPC and TFC of dried Baim of retail market were found significantly (P<0.05) highest and significantly (P<0.05) lowest in control samples than others. Twenty five samples from each source were analyzed to determine pathogenic E. coli and Salmonella sp. Hundred percent samples of dried Baim of producer and retail market were found contaminated by E. coli whereas; the controlled samples were free of E. coli. Likewise, the dried Baim samples of producer and retail market were contaminated 60% and 80% respectively with Salmonella. Dried baim sample from market was 100%, producer sample was 62% and control sample was 32% contaminated with fungi. The most common fungus species in samples were Aspergillus fumigatus, Fuserium proliferatum and Rhizopus stolonifer. The overall microbiological quality of control samples was comparatively better than the commercially produced dried Baim in Sylhet region

Effects of oxytetracycline residues in Thai Koi (Anabas testudineus Bloch) collected from Sylhet, Bangladesh

The present study was conducted to determine the levels of oxytetracycline residues in Thai Koi (Anabas testudineus Bloch) collected from some local fish markets of Sylhet Sadar Upazilla, Bangladesh during March to August, 2016. For the purpose of the study, 24 fresh Thai Koi fish samples were randomly collected from four (4) local markets of Sylhet Sadar Upazilla. Concentration of oxytetracycline residues in collected fish samples were determined by High Performance Liquid Chromatography (HPLC) at the Food Toxicology Laboratory of Institute of Food Science and Technology, Bangladesh Council of Scientific and Industrial Research, Dhaka. The results showed that 9 (37.50%) samples with detectable amount of oxytetracycline residues (mean = 42.30±3.00 ppb) were found in Thai Koi. Oxytetracycline residues level below detection limit was also reported in 15 (62.50%) samples of Thai Koi during this study. The detected residues of oxytetracycline in this fish sample did not exceed the maximum residue limit (MRL) 100 ppb recommended by the European Commission. Though residue level of oxytetracycline is lower than the MRL but long term exposure could be hazardous for human health. For that reason, control of antibiotic usage in aquaculture, regular residue monitoring, legislations and regulations for the use of antimicrobials in aquaculture and food safety education are utmost things in this regard

A bio-sustainable approach for reducing Eucalyptus tree-caused agricultural ecosystem hazards employing Trichoderma bio-sustained spores and mycorrhizal networks

The presence of the exotic Eucalyptus tree in crop-growing soil and the accumulation of its undecomposed leaves is a significant ecological hazard. The waxy coating on the leaves and the phenolic compounds takes a long time to break down under normal conditions. It is necessary to explore various fungi that can degrade these leaves for an eco-friendly solution to this problem. In this study, spores of nine native Trichoderma strains were produced on wheat agar using a lactic acid-induced sporulation strategy (LAISS). Trichoderma biosustained spores and Serendipita indica (SI) spores were applied to a rice field with accumulated Eucalyptus leaves under continuous ponding (CP) and alternate flooding and wetting conditions (AFW). Among the strains, TI04 (Trichoderma viride) and TI15 (Trichoderma citrinoviride) showed faster (5 days) and massive sporulation (1.06–1.38 × 1011 CFU/g) in LAISS. In vitro, TI04 and TI15 biosustained on Eucalyptus leaves and improved rice seedling growth and SI infection under greenhouse conditions. In the rice-field experiment, Trichoderma-treatment had a threefold yield (percentage) increase from control, with TI04 (CP) increasing the yield by 30.79, TI04 (AFW) by 29.45, TI15 (CP) by 32.72, and TI15 (AFW) rising by 31.91. Remarkably, unfilled grain yield significantly decreased in all the Trichoderma treatments. Under AFW conditions, TI04 and TI15 showed a higher pH increase. Furthermore, TI04 and TI15 under AFW had higher water productivity (t ha−1 cm−1) of 0.0763 and 0.0791, respectively, and the highest rates (percentage) of SI colonization of 86.36 and 83.16, respectively. According to the findings, LAISS-produced Trichoderma spores can be applied to break down persistent wastes and restore agricultural ecosystems through increased mycorrhizae networking

Uniform and non-uniform EBGS assisted microstrip transmission line as microwave filter

EEE/201

Effects of aflatoxin contaminated feed on the fingerlings of tilapia (Oreochromis niloticus Linnaeus, 1758)

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<0.05) in T3 (39%). Higher survival rate was also demonstrated in treatment T0 (90%) and T1 (90%) whereas significantly decreased in treatment T2 (60%) and T3 (40%). The residue of aflatoxin was not detected in T0 and T1. On the contrary, the residual effect in tilapia fingerling was evident in T2 and T3 treatment. The findings of the present study revealed that aflatoxin contaminated feed is harmful for the growth performance and survival of O. niloticus fingerlings. Further study is necessary to safeguard the aquaculture production as well as to produce healthy food for human consumption

Effect of Polyamine on Pigmentation, Reactive Oxidative Species and Antioxidant under Drought in Maize (Zea mays L.)

To examine polyamines (PAs) effect in modulating the drought induced by polyethylene glycol (PEG) in maize (Zea mays L.) seedlings (variety Khoibhutta, 8 day seedlings grown in petri dish in incubator) were subjected to 20% PEG (polyethylene glycol) followed by 20 µmol PAs, Putrescine (Put), Spermidine (Spd) and Spermine (Spm) with PEG solution for 48 hours. Sharp decrease in Relative Water Content (RWC), Chl a, Chl b, carotenoid (Car) and total pigment content was observed under drought compared to control condition, while PAs application reversed their decreasing trends. PEG significantly increased Reactive Oxidative Species (ROS) [superoxide (O2•−) and H2O2], Methyl Glyoxal (MG), Melondialdehyde (MDA) and Lipoxigenase (LOX) activity, while Pas decreased the contents considerably (except MG) as compared to those under drought. Drought increased proline content, which was further augmented in PA treatments. PAs failed to incline glyoxalase’s (Gly-I and Gly-II) activities, reduced under PEG. The activity and western blot confirmed the accumulation of Glutathione S-Transferase (GST) under drought, but PAs failed to augment the activity. Ascorbic Acid (AsA) and Glutathione (GSH) got oxidized into Dehydroascorbate (DHA) and oxidized Glutathione (GSSG) under drought but PAs effectively maintained homeostasis. Superoxide Dismutase (SOD), Peroxidase (POD), Ascorbate Peroxidase (APX), Glutathione Peroxidase (GPX), Monodehydroascorbatereductase (MDHAR), Dehydroascorbatereductase (DHAR), and Glutathione Reductase (GR) inclined in drought stressed seedlings, while Catalase (CAT) activity decreased under drought. PAs addition increased SOD, POD, GPX, CAT, MDHAR, and GR activities, but declined DHAR activity. These findings suggested important role of PAs in increasing tolerance under short term drought by modulating antioxidant effect

Developing an integrated catchment management through water quality assessment, landuse changes analysis, soil erosion study & community engagement in Bertam River Catchment, Cameron Highlands, Malaysia

The rapid boost in construction and agro-tourism activities has significantly threatened the water quality within Bertam River Catchment, Cameron Highlands (BRCC) in Malaysia during the last two decades. The scenario has drawn the attention to investigate the relationship between land use and water quality for the sustainable development of BRCC. Hence, the current research aims at developing an effective model for the sustainable management of BRCC using integrated assessment of scientific findings with quantitative social information. Scientific assessment was carried out to determine the spatio-temporal variations of water quality, to assess the landuse changes and their impacts on water quality, as well as to estimate the spatial distribution of soil erosion under different landuses. To investigate water quality, samples were collected six times from January 2014 to February 2015 from twelve preselected stations. A total of fourteen water quality parameters were analyzed. For landuse study, four-time series landuse maps (1984, 1997, 2004 and 2010) were used to analyze the land pattern changes by change detection technique using GIS approach. The revised universal soil loss equation (RUSLE) model was applied to estimate the soil erosion rate. A community based survey was also conducted using a well-structured questionnaire. The results of water quality assessment showed significant temporal and spatial differences (p20o) with the passage of time. The urban and agricultural landuses are mainly related to water quality deterioration, where the forest is associated with better water quality within BRCC. The results of soil erosion assessment indicated that the annual average soil loss rate of the catchment was predicted to be 123.23 ton/ ha/ year. Individually, the average rate for Upper, Middle and Lower sub-catchment was 27.60, 31.80 and 63.83 ton/ ha/ year respectively. Agricultural activities were the main contributor to higher soil erosion in different sub-catchments. The topography of the catchment also played a major role in controlling soil movement. Community-based survey findings showed that the people have good knowledge and perception of the catchment environment. Therefore, significant associations were observed between the scientific findings and communities‘ observations. Considering all the social and scientific findings, the proposed integrated model for BRCC management suggest that the authorities should provide the scientific information through internet and organizing workshops to motivate and create awareness. Similarly, whenever they take any initiative for management program within BRCC considering the scientific findings, they should focus more on the aged, higher educated and older residents for their higher level of awareness and positive willingness for participation. Overall, the findings of this study suggest that the effective implementation of socio-scientific integrated approach by the authorities can be an innovative initiative towards the development of sustainable catchment management

Multi-functional Polymer Composite Insulations Reinforced with Boron Nitride Nanosheets

Polymers are widely used in insulation applications, including cable insulation, battery casing, and polymer electrolytes, due to their significant advantages of low-cost availability and ease of manufacturing processability. However, their poor mechanical, thermal, and electrochemical properties pose substantial material safety, stability, and performance challenges. We show that two-dimensional (2D) boron nitride (BN) nanosheets can alleviate these concerns if appropriately designed and embedded into the polymer matrix. To achieve this, the challenges stemming from such design and fabrication include BN compatibility and molecular interactions with the host polymer matrix, alignment, and assembly of the BN nanosheets in the host polymer matrix should be addressed. This thesis focuses on investigating the effect of BN nanosheets in polyethylene (PE) insulative polymer materials. Two types of BN nanosheets, pristine and silane-modified, were chosen for this study to reveal the effect of interfacial interactions between BN nanosheets and PE molecular chains on their mechanical, thermal, and tribological properties. The results indicate that the silane functionalization increases molecular interactions at the PE and BN nanosheets interface, thus increasing mechanical reinforcement and thermal conductivity. As a result, the wear resistance of the polymer composite is also improved, as evident by experimental results. The effect of functionalized BN nanosheets was further investigated for poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF) based insulative polymer electrolytes. High-energy density LMBs suffer from thermal runaway and dendritic lithium growth, limiting long-term cycling. This thesis employed PVdF-BN composite as the battery electrolyte to address these concerns, with highly aligned BN nanosheets. Utilizing a custom-designed direct ink writing (DIW) process, highly aligned BN nanosheets were embedded in PVdF polymer composite electrolytes, enabling novel architectural designs for safe LMBs. The PVdF-BN composite electrolyte possesses higher thermal conductivity, enabling faster heat dissipation than the polymer electrolytes without BN nanosheets. The improved heat dissipation regulates uniform heat distribution and prevents hotspot formation and thermal runaway. On the other hand, dendritic lithium is mechanistically suppressed by aligned BN nanosheets. As a result, PVdF-BN composite electrolyte containing symmetric lithium cells exhibits stable Li plating/stripping over 2000 cycles without short-circuiting. This DIW printed electrolyte could be used as a model for other electrolytes or electrodes, thus enabling new chemistry and improved performances in energy-storage devices

Adverse Impact of Land Use Changes on Degrading Environment in Bertam River Catchment, Cameron Highlands, Malaysia

The present study investigates the changes in pattern of land usage within the Bertam River Catchment, Cameron Highlands, Malaysia to understand the potential impact of such changes on environment. Digitization, change detection and slope analysis techniques were applied to analyze the changing status and trends of land usage over time (1984-2010) using GIS approach. Ten categories of landuse were identified and mapped. The analytical results revealed that substantial expansion of market gardening (16.37 km2) and urban area (4.15 km2) has taken place during the study period resulting in significant decrease in forest area (22.85 km2). A major modification of floriculture land type (8.04 km2) from market gardening was also observed in the study area. Land use changes were characterized by expansion of the land use types with higher development pressure (agricultural activities and urban) and reduction of some land use types with higher environmental value (forest and scrubland). All these changes were directly related to human impact and driven by socio-economic activities. The study revealed that the economic benefit from rapid landuse changes had ultimately resulted in potential impacts on environmental degradation in the area. Sustainable landuse planning and management is urgent to handle the equilibrium between environmental conservation with land use development and utilization

Acute food insecurity and short-term coping strategies of urban and rural households of Bangladesh during the lockdown period of COVID-19 pandemic of 2020: report of a cross-sectional survey

Introduction We conducted a cross-sectional survey to assess the extent and to identify the determinants of food insecurity and coping strategies in urban and rural households of Bangladesh during the month-long, COVID-19 lockdown period.Setting Selected urban and rural areas of Bangladesh.Participants 106 urban and 106 rural households.Outcome variables and method Household food insecurity status and the types of coping strategies were the outcome variables for the analyses. Multinomial logistic regression analyses were done to identify the determinants.Results We found that around 90% of the households were suffering from different grades of food insecurity. Severe food insecurity was higher in urban (42%) than rural (15%) households. The rural households with mild/moderate food insecurity adopted either financial (27%) or both financial and food compromised (32%) coping strategies, but 61% of urban mild/moderate food insecure households applied both forms of coping strategies. Similarly, nearly 90% of severely food insecure households implemented both types of coping strategies. Living in poorest households was significantly associated (p value <0.05) with mild/moderate (regression coefficient, β: 15.13, 95% CI 14.43 to 15.82), and severe food insecurity (β: 16.28, 95% CI 15.58 to 16.97). The statistically significant (p <0.05) determinants of both food compromised and financial coping strategies were living in urban areas (β: 1.8, 95% CI 0.44 to 3.09), living in poorest (β: 2.7, 95% CI 1 to 4.45), poorer (β: 2.6, 95% CI 0.75 to 4.4) and even in the richer (β: 1.6, 95% CI 0.2 to 2.9) households and age of the respondent (β: 0.1, 95% CI 0.02 to 0.21).Conclusion Both urban and rural households suffered from moderate to severe food insecurity during the month-long lockdown period in Bangladesh. But, poorest, poorer and even the richer households adopted different coping strategies that might result in long-term economic and nutritional consequences