24 pubs · 223 cites · h-index 8
Survey reveals residents' views on rooftop gardening's benefits like air quality and mental health in Dhaka.
A radiological assessment of inland freshwater fishes of wetland haor zones, near a uranium mine and Rooppur Nuclear Power Plant (RNPP) areas, was performed. Gamma spectrometric analysis showed the accumulation of 226Ra, 228Ra, and 40K in all studied fishes, with varying degree levels of concentrations. The average radioactivity levels of 226Ra, 228Ra and 40K in haor fish samples ranged from 2.76 ± 1.51 to 22.02 ± 3.81 Bq kg−1, 1.78 ± 0.69 to 21.53 ± 1.40 Bq kg−1 and 405.51 ± 22.04 to 749.80 ± 42.65 Bq kg−1, respectively. Conversely, the respective values for Bata fish samples of Rooppur Nuclear power plant sites varied from 2.66 ± 0.80 to 6.62 ± 0.81 Bq kg−1, 2.31 ± 0.62 to 5.18 ± 49.81 Bq kg−1 and 342.00 ± 4.98 to 461.45 ± 18.00 Bq kg−1, respectively. Activity levels of Taki fish (Channa punctatus) from haors zones were almost 3–4 times higher than the Meni fish (Nundus nundus) of the same locations and Bata fish (Labeo bata) of the RNPP site. The general public may attain doses of 244.54 µSv from the consumption of haor fish and 84.02 µSv from the fish of the RNPP sites yearly. The chance of an increase in cancer risk from intake of haor fish was higher than the ICRP values of 2.9 × 10−4. Univariate statistics showed that 226Ra and 228Ra radionuclides do not normally distribute, whereas 40K is normally distributed in the studied fish species. Multivariate statistical analysis demonstrated that the radioactivity and estimated radiological parameters are strongly positively correlated with 226Ra and 228Ra, and also positively correlated with 40K. Hence, it indicated that the contents in the freshwater fish species are usually controlled and influenced by similar geogenic sources and occur together. It is presumed that the radiological risk is mostly associated with and dominated by the uranium and thorium series and non-series 40K radionuclides in the freshwater fish species.
Bandarban hill district is one of the main hilly areas of Bangladesh which is surrounded by forests and enriched with ecological resources and biodiversity. Ecosystems sustain, generate for, regulate, and offer cultural services that are essential to human well-being. Hence, it is important to reconnoiter the current situation of forests’ ecosystem services available in the Bandarban hill district with the local farmers’ realization of the well-being they receive from those ecosystem services. Through the present study, it was investigated the available ecosystem resources in some two hilly upazilas of Bandarban district, the farmers’ perception towards those ecosystem services and human well-being and also farmers’ socioeconomic characteristics which influence their perception. To investigate these, 80 respondents were interviewed through the help of a semi structured interview schedule. The findings of the study suggested that 28 ecosystem services were identified and six out of these were showing increasing trend including crop and vegetable cultivation and other 22 were following decreased. The respondents received improve to moderate services from those 28 ecosystem services which were exhibited through their perception as 68% of them had moderate to improve perception towards ecosystem services. According to the study's findings, respondents who had higher levels of education, family income, agricultural training, residential distance from forests, and income from ecosystem services had better perceptions of ecosystem services and human well-being. Because the residents' perceptions would make them aware of the need to conserve the forest environment, policymakers should base future decisions on the findings of this study.
We study radiation exposure resulting from the consumption of farm-raised freshwater fish species that form an essential part of the Bangladeshi diet. The levels of radioactivity in the human diet are of particular concern, requiring assessment of possible radiological risks to human health. Therefore, a comprehensive study was carried out to determine the radioactivity levels (226Ra, 228Ra, and 40K) in fifteen commonly available varieties of farm-raised fishes. The gamma-ray spectroscopic analysis showed the presence of radionuclides of 226Ra, 228Ra, and 40K in all studied fishes, but varying degrees. The highest radioactivity levels of 226Ra, 40K, and 228Ra were observed in Rui (Labeo rohita) and Tilapia (Oreochromis mossambicus) with values of 8.50 ± 0.30, 513.28 ± 1.59, and 7.41 ± 0.15 Bqkg−1, respectively. The respective radioactivity levels were lowest in Silver carp (Hypophthalmichthys molitrix), Mola (Amblypharyngodon mola), and Koi (Anabas testudineus) with values of 0.83 ± 0.38, 171.07 ± 1.60, and 0.62 ± 0.30 Bqkg−1. The doses for 226Ra, 228Ra, and 40K due to consumption of a kilogram of farm fish were assessed and range from 5.56 (Sarputi – Puntius sarana) to 54.36 µSvy–1 (Rui – Labeo rohita), 9.77 (Koi – A. testudineus) to 116.79 µSvy–1 (Tilapia – O. mossambicus), and 24.23 (Mola – A. mola) to 72.69 µSvy–1 (Rui – Labeo rohita), respectively. In most cases, the estimated probability of an increase of cancer risk from daily intake of the farm-raised fish diet representing a minor fraction of ICRP values. Statistical analysis shows that the radioactivity and estimated radiological parameters are strongly correlated with 226Ra and 228Ra, while weakly correlated to 40K, suggesting that radiological risk is basically associated and controlled by the activity levels of uranium and thorium series radionuclides.
Investigations were carried out to evaluate the effect of gamma radiation (1.0 and 1.5 kGy) and food-grade preservative (2% potassium sorbate) on the shelf-life of refrigerated (4°C) Spotted snakehead, Channa punctata (Bloch, 1793). Quality assessments were evaluated by sensory (OS), chemical (TV), microbial (TBC and TCC) analyses. Based on control panel, OS was shown to be gradually decreased with the storage time. Irradiated and potassium sorbate treated samples were found acceptable (edible) up to 28 and 21 days, respectively of storage period. TV were lower in irradiated samples with dose of 1.5 kGy compared to other samples. Though microbial load of each of the irradiated samples were within the acceptable limits up to 28 days but 1.5 kGy dose was found more effective. Gamma radiation in combination with good refrigeration could be most effective treatment for the shelf-life extension and microbiological quality improvement for snakehead preservation. Moreover, this preservation technique may be applicable for other fish species to enhance food safety for public health issues. Jahangirnagar University J. Biol. Sci. 9(1 & 2): 1-12, 2020 (June & December)
Madhupur Sal (Shorea robusta) forest, the largest belt of natural Sal forest in Bangladesh, is rich in ecological resources and biodiversity. In recent years, human disturbance leads to biodiversity loss from the forest, and it has a successive effect on the services that the forest provides. Thus, it is crucial to explore the present condition of the forest’s available ecosystem services with local people’s consciousness about the ecosystem. The present study investigated the available ecosystem services of Madhupur Sal forest, respondents’ perception towards those services and the socio-demographic characteristics of the respondents that influenced their perception. Data were collected by interviewing 90 respondents with a focus group discussion. Most of the respondents in the study area were ethnic people (Garo). A total of 20 ecosystem services were identified where soil erosion control, mental peace and maintenance of soil fertility were the top-ranked services. About 83% of the respondents had moderately favorable perception towards ecosystem services. The study results showed that the respondents with a higher level of education, higher family annual income, and more training received on agriculture perceived ecosystem services to a greater extent than others. So, improvement of their perception towards ecosystem services can make them aware of forest biodiversity conservation.
Nitrogen (N) loss from rice production systems in the form of ammonia (NH ₃ ) can be a significant N loss pathway causing significant economic and environmental costs.
The forensically-important Dipteran flies, Lucilia sericata and Megaselia scalaris, complete their life-cycles in perishable, filthy, unhygienic and fowl-smelled natural diets, which hinder the rearing work and the indoor environment of laboratory. To overcome this unhygienic condition, a newly formulated simple, comparatively more hygienic one was prepared and evaluated for the rearing of these two flies. This artificial diet, when compared to their natural diets for rearing at different temperatures, it demonstrated no significant difference for their developmental durations. Statistical analyses proved that the difference between the natural and formulated diet was not responsible for their developmental durations; rather their rearing temperatures played a significant role in this respect. Taken together, these findings showed that the newly formulated artificial diet might facilitate the hygienic and easy rearing of these flies for forensic and medical entomology as well as other research purposes in terms of nutrition, cost-effectiveness and availability of the ingredients of diets. Asian Australas. J. Biosci. Biotechnol. 2018, 3 (2), 86-92
An optimal design of a spur is the first requirement to make it sustainable and function properly. In view of that, a thorough understanding to the hydro- and morpho-dynamics due to spurs is essential. This paper presents a literature review on the effect of spurs to obtain the most recent design criteria. Perpendicular and upstream aligned impermeable spurs have large disturbances to flow and less stability because of strong vortices and associated scour. Downstream aligned spurs minimize scour holes, but there is a chance of strong return current which could be controlled allowing flow through them. A series arrangement of spurs is important to have the desired results with a special care for the first one. Several equations have been presented in the paper for predicting the scour depth. But, they have to be used carefully. Different flow environments developed by spurs are favorable for various aquatic species. However, it is important to maintain almost a stable flow condition providing stable spurs.