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Aims: Transplant (T) aman is occupying a major portion of rice based cropping system in Sylhet region, Bangladesh. Still majority of farmers are circled to cultivate local T. aman rice cultivars, but the overall yield is very low. Agronomic management can be a good option to boost up the yield potential of these local cultivars. This study was conducted to observe the influence of planting geometry on the yield of local aman cultivars. Study Design: Randomized complete block design. Place and Duration of Study: The experiment was conducted to find out optimum plant density of local cultivars of T. aman rice during the period from August 2017 to December 2017 at farmer’s field located at Jointapur, Sylhet. Methodology: The study were replicated thrice in randomized complete block design considering four rice cultivars viz. Beruin (V1), Moinasail (V2), Nagrasail (V3) and, BRRI dhan49 (Control, check variety) (V4) and four plant spacings viz. (15 × 15) cm (S1), (20 × 15) cm (S2), (20 × 20) cm (S3) and (20×25) cm (S4). Results: The results indicated that the highest grain yield were recorded in (2.65 t ha-1) in the variety V4, which was statistically similar with V3 (2.60 t ha-1). The highest grain yield (2.87 t ha-1) was obtained (V4 × S4) while the lowest (1.58 t ha-1) from (V1 × S1). Among the local varieties highest grain yield (2.64 t ha-1) recorded in (V3 × S4) which was statistically similar (V4 × S4). Conclusion: Outcomes of the study revealed that Nagrasail (V3) with (20 × 25) cm plant spacing is a promising option, and isthe best one for local T. aman cultivar cultivation in Sylhet region.

Aims: In any agricultural production system, combining organic and chemical fertilizers into the soil is regarded as a useful management practice since it boosts soil fertility and crop growth. The goal of the current study was to ascertain the effects of combined organic and inorganic fertilizer treatment on the yield contributing traits, yield, nutrient uptake and nutrient use efficiency of BRRI dhan89 in a single Boro cropping area. Study Design: With three replications, the experiment was set up in a two factor RCB design. Organic fertilizer treatment was regarded as Factor-a, while inorganic fertilizer as Factor-b. Place and Duration of Study: The experiment was conducted in a farmer's field in Nagarkanda, Faridpur, Bangladesh from December 2021 to May 2022. Methodology: Factor-a comprises two treatments named cowdung (CD) and poultry manure (PM). Factor-b comprises five treatments named T0 (control), T1, T2, T3, and T4. In the main field, organic fertilizers were used just two weeks prior to transplanting. In all inorganic fertilizer treatments, Urea top dressed in three installments at 15 DAT, 30 DAT and 5 days before panicle initiation. In T4 treatment, MoP split at two installments, one during final land preparation and another 5 days before panicle initiation. Results: The highest no. of effective tillers, yield contributing traits, grain yield, straw yield, nutrient concentration (%) in both grain and straw, nutrient uptake by grain and straw observed in organic fertilizer treatment PM, inorganic fertilizer treatment T4 and treatment interaction PM × T4 whereas the lowest found in CD, T0 and CD × T0. The maximum nutrient use efficiency was recorded by PM × T4 treatment interaction and minimum in CD × T1. Conclusion: Comparing all of the treatments employed in the current study, the treatment interaction PM × T4 generated the best results for BRRI dhan89 in a single Boro cropping area.

To identify suitable nitrogen management practices for local fine and aromatic rice cultivars an experiment was carried out at Farmer’s field at Jointapur, Sylhet region of Bangladesh during the period from August 2017 to December 2017. The experiment was replicated thrice in randomized complete block design assigning factor A: rice cultivars viz. Beruin (V1), Moinasail (V2), Nagrasail (V3) and, BRRI dhan49 (Control, check variety) (V4) and factor B: N sources viz. N 100% chemical (F1) , 50% N from FYM + 50% from Urea (F2) , 50% N from Vermicompost+ 50% from Urea (F3) and farmers practice (F4). Nutrients P,K, S and Zn (100%) were supplied from chemical sources of triple super phosphate, muriate of potash, gypsum and zinc sulphate, respectively. Only N was supplied from different organic and inorganic (urea) sources. Fertilizers were applied at the rate of 140-33-38 kg ha-1 of NPK for farmers’ practice, 90-15-60-12-1 kg ha-1 N, P, K, S and Zn for the variety of BRRI dhan49 and 45-9-33-9-1 kg ha-1 N, P, K, S and Zn for 3 local rice varieties. The results indicate that, BRRI dhan49 (V4) gave the highest yield (2.97 t ha-1) among the varieties. Among the local varieties Nagrasail (V3) gave the highest yield (2.24 t ha-1). In case of farmers practice, highest grain yield was obtained F4 (3.50t ha-1) followed by F1 (2.32 t ha-1). Interaction effect also revealed, the highest grain yield (3.23 t ha-1) in (V4× F4). Among the local varieties Nagrasail gave highest grain yield (2.58 t ha-1) along with F4. Farmer’s practice fertilizer management is a promising option, and Nagrasailis the best one for local T. aman cultivars cultivation in Sylhet region of Bangladesh.

The associations between digital media use and mental well-being among children and adolescents have been inconclusive. We examined (i) the associations between digital media use and mental health outcomes, anxiety, depression, and ADHD, (ii) whether family resilience and neighborhood factors attenuate the associations, and (iii) whether sleep mediates these associations. We used the National Survey of Children’s Health data from 2019 to 2020. A total of 45,989 children’s (6–17 years) data were analyzed in this study. Multivariate logistic regression was used to assess the associations between digital media use and anxiety, depression, and ADHD. Path models and Paramed command in STATA were used to test the role of sleep as a mediator of these associations. The prevalence of heavy digital media users (who spent 4 or more hours per day) among the analytic sample was 30.52%, whereas anxiety was 13.81%, depression was 5.93%, and ADHD was 12.41%. Children in the heavy media user group had 63% increased odds of anxiety (95% CI: 1.32–2.01) and 99% increased odds of depression (95% CI: 1.35–2.94) after adjusting for sociodemographic factors, compared to the children in light media user group (who spent Conclusions: Family resilience and neighborhood factors protect against the harmful effects of digital media use. Further research is needed to examine the relationships of media contents, the presence of electronic devices in bedrooms, and sleep quality with mental health. What is Known: • Spending long hours on digital media may adversely affect children and adolescents' health and development. However, the mediating role of sleep in the association between digital media use and mental health outcomes is inconclusive. What is New: • Digital media use has detrimental effects on anxiety and depression. However, family resilience and neighborhood factors attenuated the association. The study highlights the importance of positive family functioning and neighborhood conditions reducing the harmful effects of digital media use.

Adequate and effective disaster preparedness in each sector is indispensable to abate disaster impacts and intensify disaster resilience in Bangladesh for achieving sustainable development goals by 2030. Though university students can play a significant role in promoting and strengthening disaster management activities in the community by sharing their knowledge and experience on disasters, very few studies focused on students' disaster preparedness. In this study, we assessed university students' perceived and actual disaster preparedness and explored the factors influencing disaster preparedness of male and female students. The cross-sectional survey method was adopted to collect 704 student respondents' data from the Dhaka University using a structured questionnaire by face-to-face interview. We found that university students perceived that they were moderately prepared for disaster; however, their actual disaster preparedness was relatively low. Disaster likelihood and disaster knowledge significantly influenced students’ perceived and actual disaster preparedness. However, no statistically significant mean differences were found between the male and female respondents regarding their perceived and actual disaster preparedness. In addition, students with higher disaster knowledge were more likely to have a higher perceived and actual disaster preparedness. Moreover, gender-segregated multiple linear regression analyses showed that disaster knowledge was significantly associated with the male students' actual and perceived preparedness, and female students' perceived preparedness. Besides, disaster concern and university preparedness were significant predictors of the female students' perceived preparedness, whereas male students' perceived preparedness was significantly influenced by disaster likelihood and university preparedness. Therefore, it is recommended that disaster education should be introduced into the university curricula, including disaster management training, drills, and simulations. The study provides strong evidence of the need for developing a comprehensive disaster plan at the university and has policy implications. However, further research is needed to explore college and school students' disaster preparedness knowledge and practice in Bangladesh.

Trace metals contamination is ubiquitous in the riverine environments of Bangladesh. Trace metals contamination is increasing rapidly in Dhaleshwari River due to rapid urbanization and industrialization along the riverbank, especially after the establishment of the Tannery Industrial Estate at Savar in Dhaka District. As a result, aquatic ecosystems, including fish and prawn species of the river, are contaminated by various trace and toxic metals. We examined the concentrations of 10 trace metals (Cr, Fe, Zn, Mn, Co, Ni, Cu, As, Hg, and Pb) in 20 different fish and prawn species (n = 41) which are commonly found in the Dhaleshwari River using energy-dispersive X-ray fluorescence (EDXRF) method. The potential human health risks (noncarcinogenic and carcinogenic) of the trace metals were calculated by using Target Hazard Quotient (THQ), Hazard Index (HI), and Target Cancer Risk (TR) indices. The mean concentration (mg/kg; ww) of the trace metals in analyzed riverine fish and prawn species was in the order of Fe > Zn > Cu > Cr > Mn > Co > Hg > Ni > Pb > As. The highest concentration of Fe (74.67 mg/kg) and Cr (4.64 mg/kg) was found in Mystus bleekeri, whereas Zn (38.89 mg/kg) and Cu (17.47 mg/kg) were found in Rohtee cotio and Glossogobius guiris, respectively. The target hazard quotient (THQ) values were less than 1 (no detrimental health effects) for all the specific metals in most of the species except M. bleekeri (1.61), G. guiris (1.29), Corica soborna (1.28) for Cr, and Macrobrachium malcolmsonii (1.19) for Hg indicate that the noncarcinogenic health risk to humans by consuming those species was relatively low. However, nine out of twenty species found higher Hazard Index (HI) values than the recommended value (HI = 1), indicating that regular consumption of these fishes may have considerable harmful effects on human health. The highest HI value (2.85) was found in M. bleekeri. Moreover, target cancer risk (TR) values showed that frequent intake of some species for prolonged periods might pose a carcinogenic risk due to Cr and Ni contamination as they were higher than the maximum accepted value of 10−4. Based on the present study, it is imperative to take an urgent initiative to control or prevent the trace metals contamination in the Dhaleshwari River and minimize the human health risks associated with the consumption of fish and prawn species in this river in Bangladesh.

A stabilizing control scheme based on a Lyapunov function is proposed for wireless power transfer (or WPT) systems. A state-space model of the WPT system is developed and the Lyapunov function is formulated based on an energy equation of the system involving state variables. The internal resistance of a battery varies during charge and discharge. Therefore, if a WPT system is used to charge a battery, its output load will vary. Furthermore, the coupling coefficient between the transmitter (primary) and receiver (secondary) coils decreases when they are misaligned. Comparative case studies are conducted to verify the efficacy of the proposed controller in maintaining stability of the WPT system under load variation and acute misalignment of transmitter and receiver coils.

As frontline health caregivers, nurses must be adequately prepared to respond effectively to disasters. Therefore, it is necessary to assess nurses' disaster management capacity to know their preparedness levels, especially for a densely populated Megapolis like Dhaka, which is at high risk of disasters. Thus, the study aimed to examine Dhaka city nurses' knowledge, skills, preparedness (KSP) for disasters and explore the factors influencing the KSP levels. A self-explanatory descriptive survey questionnaire was developed adopting the Disaster Preparedness Evaluation Tool (DPET) in Bangla language for quantitative data collection. Following multistage sampling, 410 nurses' data were collected from eight hospitals in Dhaka city. The nurses in Dhaka city had moderate levels of knowledge, skills, and preparedness for disaster management, reflecting that they need more development to deal with disasters effectively. Moreover, multiple linear regression analyses indicate that nurses' disaster knowledge, skills, and preparedness scores were significantly positively associated with training on disaster management (p < 0.001) and disaster response experience (p < 0.001). In addition, one-half of the respondents demanded more drills and exercises on disaster management in their workplaces to enhance their disaster skills and preparedness. Furthermore, disaster education should be incorporated into the nursing curriculum, which would play a seminal role in preparing them for future disaster management.

Background: Human health and well-being are adversely affected by the multidimensional effects of COVID-19. This study examined the prevalence of anxiety and depression, and their association with some less explored factors like perceived and relative health status, having elderly members in the family, fear for own and family future, and others from the Asian context. Methods: Using a cross-sectional online survey, data were collected from the population aged 18 and above years, on socio-demographic and economic attributes, and two separate twelve-item scales were used to assess the level of anxiety and depression. The score of anxiety (x=21.74 and s=8.20; α=0.897) and depression (x=24.38 and s =10.30; α=0.937) were ranges from 12 to 60. High scores of anxiety and depression scales indicate higher levels of anxiety and depression. Both descriptive and multivariate analyses were performed to report the level of anxiety and depression by socio-demographic and other attributes; multivariate linear regression (forwarded method) was used to analyze the effects of each predictor on the anxiety and depression scores. Results: The findings revealed that respondents' concern for their family's future has a significant positive effect on anxiety scores but has a significant negative effect on depression scores; On the other hand, having elderly family members has a significant association with lower anxiety scores but higher depression scores. Poor conditions of (1) perceived physical health status in comparison with others, (2) self-evaluated physical health status, and (3) perceived physical health status in comparison to before COVID-19 lead to significantly higher anxiety scores. Anxiety score remained the most critical factor among all the predictors in explaining depression score. Limitations: Anxiety and depression of all people are not reflected in the results as we used online platforms to collect data. Some misclassifications might occur for using self-reported outcome measures and socially desirable responses collected through the cross-sectional survey. Conclusions: The increased level of anxiety and depression during COVID-19 of adult people in Bangladesh are associated with several factors of which their greater concern about the future of their own and family members and health-related attributes are important. These findings may lead to developing interventions to reduce the psychological crisis during the pandemic in Bangladesh. Funding Information: None. Declaration of Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Ethics Approval Statement: The research was conducted in accordance with the Helsinki Declaration as revised 1989. Informed consent.

Every year thousands of people are being displaced in coastal areas of Bangladesh due to natural calamities associated with climate change, known as Internally Displaced Peoples (IDPs). Climate change adaptation measures play a significant role in coping with the alteration of climatic components, while various forms of barriers hinder the sustainability of adaptation. This research was conducted to understand the perception of IDPs on climate change impact on health in the coastal areas of Bangladesh, including the adaptation practices and barriers to the coping strategies. To fulfill the objective, 420 individual surveys were conducted randomly in two Sub-districts of Khulna district in Bangladesh. The findings reveal that the riverbank erosion and cyclones were the primary reasons for displacement, and the social relationships were hampered in the new places of living. Also, the temperature in summer and winter, and the rainfall intensity increased, whereas rainfall slightly decreased over the last ten years. Differences of opinion were identified about the effects of the changing climatic variables on the respondents' health between the previous and present locations. Despite practicing different adaptive strategies, the weak financial condition and a lack of access to health care information are mostly hindering the sustainability of adaptation. This research may help policymakers in taking proper initiatives to ensure sustainable adaptation practices in the coastal areas.

Every year thousands of people are being displaced in coastal areas of Bangladesh due to natural calamities associated with climate change, known as Internally Displaced Peoples (IDPs). Climate change adaptation measures play a significant role in coping with the alteration of climatic components, while various forms of barriers hinder the sustainability of adaptation. This research was conducted to understand the perception of IDPs on climate change impact on health in the coastal areas of Bangladesh, including the adaptation practices and barriers to the coping strategies. To fulfill the objective, 420 individual surveys were conducted randomly in two Sub-districts of Khulna district in Bangladesh. The findings reveal that the riverbank erosion and cyclones were the primary reasons for displacement, and the social relationships were hampered in the new places of living. Also, the temperature in summer and winter, and the rainfall intensity increased, whereas rainfall slightly decreased over the last ten years. Differences of opinion were identified about the effects of the changing climatic variables on the respondents' health between the previous and present locations. Despite practicing different adaptive strategies, the weak financial condition and a lack of access to health care information are mostly hindering the sustainability of adaptation. This research may help policymakers in taking proper initiatives to ensure sustainable adaptation practices in the coastal areas., Environmental hazard; Environmental health; Environmental pollution; Coastal geography; Natural hazard; Climate change; Health; Impact; Adaptation; Barriers; Coastal areas

Safety culture plays a significant role to reduce unintentional deaths and injuries in many industries and educational institutions especially in developing counties; however, students are more susceptible to accidents in Bangladesh, little attention has given to promote safety culture at university campuses. This study aimed to investigate the current level of safety attitude and awareness, and safety behaviors of the Dhaka University students and to examine the factors associated with the safety culture at the university campus. A cross-sectional survey was conducted among 964 randomly selected students of the Dhaka University using a paper-based structured questionnaire composed of 14 items related to safety attitude and awareness, and another 14 items related to safety behaviors. The study found that the safety attitude and awareness, and safety behaviors levels of the students are not satisfactory enough. The female university students have a significantly higher level of safety culture than their male counterparts. However, we find no significant difference in the safety culture between resident and non-resident students, and among the students of different age groups, academic disciplines, and academic years. It is therefore recommended that various safety education courses, training, and awareness programs should be aimed to improve and promote safety culture at the universities in Bangladesh with special attention to male students. Further studies are needed to investigate the safety culture of school and college students in rural and urban areas of Bangladesh.

In this paper a scalable and controllable dc microgrid architecture has been presented with a source-end to load-end one-way communication based control interface to substantiate efficacious power sharing among five power management units (PMUs) attached to batteries. The system comprises a source converter and a load converter. The source converter consists of a maximum power point tracking (MPPT) controller with a boost average model and the load converter consists of a fanout node and five PMUs. The voltage of the photo voltaic (PV) array is boosted up to 400 V for transmission purpose. Perturb and observation algorithm is used for MPPT implementation. A pulse width modulation (PWM) switched full bridge (FB) converter in the fanout node is constructed to lower the source-end voltage and to generate a fixed intermittent dc bus of 48 V. Buck converter topology is used to design the PMUs and each PMU is controlled in a way to generate an output voltage suitable for a 12 V battery charging application. Sensing the solar irradiance level a one-way communication premise is designed to control the power flow towards and sharing among the PMUs so that the more important units receive more power in a crisis situation. The proposed framework has been tested in MATLAB/Simulink platform and the performance evaluations yield to system efficiencies of more than 85% for different irradiance levels.

This paper documents a scalable dc microgrid architecture offering phase shifted full bridge (PSFB) converter based power management units (PMUs). There is a set of two PMUs connected to 36 V and 12 V batteries respectively. The energy source is a photo-voltaic (PV) array of 315 W maximum power. A source converter comprising a maximum power point tracking (MPPT) unit and a boost converter has been designed to generate a dc bus. The MPPT unit applies incremental conductance method to detect the peak power condition. A load converter comprises a set of parallely connected PMUs and batteries and PMUs are responsible for supplying power to the batteries and utility loads. PSFB converter in each PMU enables zero voltage transition by phase shifted pulse width modulation (PWM). In this paper the overall system is modeled and simulated on MATLAB/Simulink platform. A generic Lead acid battery model has been used and a voltage source converter (VSC) with an R-L load has been delivered power. The behavior of the system has been tested in both without and with load situations and the evaluated power efficiency values corroborate the reliability of the proposed design. The respective MATLAB/Simulink simulation waveforms and results are presented in this paper.

Bangladesh – one of the most densely populated countries of the world— has plentiful water sources, but these sources are being polluted continuously. Both surface water and groundwater sources are contaminated with different contaminants like toxic trace metals, coliforms as well as other organic and inorganic pollutants. As most of the population uses these water sources, especially groundwater sources which contain an elevated amount of arsenic throughout the country; health risk regarding consuming water is very high. Death due to water-borne diseases is widespread in Bangladesh, particularly among children. Anthropogenic sources such as untreated industrial effluents, improper disposal of domestic waste, agricultural runoffs are the main contributors regarding water pollution. A total water pollution status of this country, as well as the sources of this severe condition, is crucial to evaluate public health risk. For this purpose, we reviewed hundreds of well recognized international and national journals, conference proceedings and other related documents to draw a complete picture of recent water pollution status and its impact on public health; also the sources of water pollution are identified.

Results of four representative pedons of the Old Himalayan piedmont, collected horizonwise from Thakurgaon district, revealed that the color of the topsoil was dark grayish brown to dark yellowish brown and that of the subsoils was dark yellowish brown to light olive-brown and light brownish grey when moist. The soils have moderately well drained conditions except Baliadangi soils which are imperfectly drained. Prismatic to subangular blocky structure has been developed in subsurface horizons of all the profiles, whereas massive structure was found in the surface horizons. Sand was by far the dominant fraction in the soils. The texture of the soils varied from clay loam to sandy loam. The irregular vertical distribution patterns of sand/silt ratio in the profiles indicate the heterogeneous nature of the parent materials. The pH of the soils ranged from 5.4 to 6.26. The organic matter contents as well as total nitrogen of these soils were, in general, low. The C/N ratios of the soils varied from 4.3 to 10.3. The cation exchange capacity (CEC) in most of the studied soils were low. Calcium and magnesium were the dominant cations in all the soils. DOI: http://dx.doi.org/10.3329/jasbs.v38i2.15610 J. Asiat. Soc. Bangladesh, Sci. 38(2): 199-206, December 2012

Freshwater crab Paratelphusha lamellifrons from Padma River were investigated for proximate and fatty acid composition. Proximate analyses of the claw and body meat of crab revealed the presence of moisture, crude protein, crude lipid and ash and their amount ranges between 71.72%-81.30%, 35.01%-49.06%, 13.24%-17.64% and 19.62%-22.12% respectively, on a dry weight basis. Except lipid (17.64%), claw meat content higher amount of moisture (81.30%), protein (49.06%) and ash (22.12%) compared to body meat. The fatty acid composition was analyzed by GC-FID and total 12 types of fatty acid were recorded in the fat isolated from crab. Among the recorded fatty acids MUFA were observed as the highest (42.85%), SFA were the second (25.96%) whereas, polyunsaturated (PUFA) were the lowest (15.02%). The fatty acid compositions showed that the SFA, MUFA and PUFA were dominated by palmitic acid (20.49%), oleic acid (23.99%) and linoleic acid (9.81%) respectively. The proximate and fatty acid composition of the present study demonstrated that these species (P. lamellifrons) are a promising source of essential fatty acids ω-3 and ω-6 namely, DHA and EPA.

DOI: http://dx.doi.org/10.3329/dujbs.v21i2.11519Dhaka Univ. J. Biol. Sci. 21(2): 201-205, 2012 (July)

Ultrasound elastography is a medical imaging technique to visualize the tissue stiffness using a conventional ultrasound machine. To compute the elastogram, the radiofrequency echo signals are acquired before and after a small applied deformation. Then the local tissue displacement field is estimated by searching the peak of the cross-correlation function between small segments of pre- and post- deformation signals. Finally, the corresponding strain distribution is imaged by differentiating the displacement field. However, the pre- and post- signals are not exactly the shifted versions of one another and hence the displacement estimation is inaccurate and the resulting strain image is highly noisy. In this paper, we propose a novel technique to estimate the strain image from the ratios of the peak frequencies of the pre- and post- deformation signals. Unlike other time/frequency domain reported schemes, our proposed technique does not use cross-correlation or any other similarity measures and directly estimate the strain in the power spectral density domain. Simulation experiments are conducted at various strain conditions and the results show that the proposed method can be an effective and computationally efficient algorithm for ultrasound elastography.

Neural Network (NN) is widely used in all aspects of process engineering activities, such as modeling, design, optimization and control. In this paper work, in absence of real plant data, simulated data (such as sales gas flow rate, pressure, raw gases flow rates and input heat flow associated with a heater used after dehydration) from a detailed model of Kailashtilla gas processing plant (KGP) within HYSYS is used to develop NN based model. Thereafter NN based model is trained and validated from HYSYS simulator generated data and that framework can predict the output data (sales gas flow rate and pressure) very closely with the simulated HYSYS plant data. The preliminary results show that the NN based correlation is adequately able to model and generate workable profiles for the process.