Developments of low cost riverbank protection in Bangladesh

Over the last two decades the Bangladesh Water Development Board (BWDB) has developed the widely accepted riverbank protection technology of geotextile bag revetments, consisting of multiple layers of systematically dumped geobags below low water plus a single layer of concrete blocks above low water. The original design characteristics from the early 2000s have proven sufficient for the most common application alongside largely agricultural land, with emphasis on the dimensions of the toe apron. In case of more severe design requirements, geotextile bags have been used as filter layer covered with rock. By and large geotextile bag revetments have become the backbone for a more stabilized Brahmaputra River System with a narrowed river corridor

Predictors of Locoregional Recurrence in Oral Squamous Cell Carcinoma

Introduction: Lip and oral cavity cancer is the third and fifth most frequent cancer for men & women respectively in Bangladesh. Locoregional recurrence after primary surgery is common for oral cancer due to aggressive local invasion and metastasis. The objective of this study was to analyze the predictors of locoregional failure in a tertiary center hospital. Materials and Methods: A prospective cohort study was designed to analyze the presence of recurrences of OSCC patients after surgery. The purposive sampling technique was used to include patients in the study. Excision of the primary tumor was done with neck dissection followed by reconstruction with local or regional flap. The variables considered were demographic information, site, TNM stage at diagnosis, margin status, lymph node metastasis, perineural invasion, recurrence, and the adjuvant therapy used for disease control. Patients were followed up by hospital revisits or phone calls and necessary information was collected through a standardized data collection sheet. Results: A total of 39 patients were included for data analysis. The male to female ratio was 1:2 and the most common primary site was mandibular alveolar mucosa (31%). Nearly 90% of patients were admitted with stage ׀׀׀ or ׀ᴠ lesions and tumor margin was positive in 21% of cases. Lymph node metastasis and perineural invasion were identified in 64% and 23% of cases respectively. Recurrence developed in 14 patients (36%) during the average follow-up of 13 months. Recurrences were more common in females (42%) and Postoperative histopathology showed a positive margin, perineural invasion, and N3 neck node. Univariate logistic regression analysis for locoregional recurrence showed no significant association between the variables and recurrence. Patients with clinically palpable lymph node, grade 2 lesion, presence of perineural invasion, presence of co-morbidity, patients who did not receive any adjuvant therapy, and patients who had metastatic neck node showed an increased odds ratio (OR>1). Conclusion: The clinicopathologic and treatment-related factors of recurrence in OSCC were explored in this study. Although no significant association was identified between the variables and recurrence of lesions, a high recurrence rate was observed in a shorter span of the follow-up period

Group sequential designs in pragmatic trials : feasibility and assessment of utility using data from a number of recent surgical RCTs

Background Assessing the long term effects of many surgical interventions tested in pragmatic RCTs may require extended periods of participant follow-up to assess effectiveness and use patient-reported outcomes that require large sample sizes. Consequently the RCTs are often perceived as being expensive and time-consuming, particularly if the results show the test intervention is not effective. Adaptive, and particularly group sequential, designs have great potential to improve the efficiency and cost of testing new and existing surgical interventions. As a means to assess the potential utility of group sequential designs, we re-analyse data from a number of recent high-profile RCTs and assess whether using such a design would have caused the trial to stop early. Methods Many pragmatic RCTs monitor participants at a number of occasions (e.g. at 6, 12 and 24 months after surgery) during follow-up as a means to assess recovery and also to keep participants engaged with the trial process. Conventionally one of the outcomes is selected as the primary (final) outcome, for clinical reasons, with others designated as either early or late outcomes. In such settings, novel group sequential designs that use data from not only the final outcome but also from early outcomes at interim analyses can be used to inform stopping decisions. We describe data from seven recent surgical RCTs (WAT, DRAFFT, WOLLF, FASHION, CSAW, FIXDT, TOPKAT), and outline possible group sequential designs that could plausibly have been proposed at the design stage. We then simulate how these group sequential designs could have proceeded, by using the observed data and dates to replicate how information could have accumulated and decisions been made for each RCT. Results The results of the simulated group sequential designs showed that for two of the RCTs it was highly likely that they would have stopped for futility at interim analyses, potentially saving considerable time (15 and 23 months) and costs and avoiding patients being exposed to interventions that were either ineffective or no better than standard care. We discuss the characteristics of RCTs that are important in order to use the methodology we describe, particularly the value of early outcomes and the window of opportunity when early stopping decisions can be made and how it is related to the length of recruitment period and follow-up. Conclusions The results for five of the RCTs tested showed that group sequential designs using early outcome data would have been feasible and likely to provide designs that were at least as efficient, and possibly more efficient, than the original fixed sample size designs. In general, the amount of information provided by the early outcomes was surprisingly large, due to the strength of correlations with the primary outcome. This suggests that the methods described here are likely to provide benefits more generally across the range of surgical trials and more widely in other application areas where trial designs, outcomes and follow-up patterns are structured and behave similarly

Households' perception of climate change and human health risks: A community perspective

<p>Abstract</p> <p>Background</p> <p>Bangladesh has been identified as one of the most vulnerable countries in the world concerning the adverse effects of climate change (CC). However, little is known about the perception of CC from the community, which is important for developing adaptation strategies.</p> <p>Methods</p> <p>The study was a cross-sectional survey of respondents from two villages--one from the northern part and the other from the southern part of Bangladesh. A total of 450 households were selected randomly through multistage sampling completed a semi-structure questionnaire. This was supplemented with 12 focus group discussions (FGDs) and 15 key informant interviews (KIIs).</p> <p>Results</p> <p>Over 95 percent of the respondents reported that the heat during the summers had increased and 80.2 percent reported that rainfall had decreased, compared to their previous experiences. Approximately 65 percent reported that winters were warmer than in previous years but they still experienced very erratic and severe cold during the winter for about 5-7 days, which restricted their activities with very destructive effect on agricultural production, everyday life and the health of people. FGDs and KIIs also reported that overall winters were warmer. Eighty point two percent, 72.5 percent and 54.7 percent survey respondents perceived that the frequency of water, heat and cold related diseases/health problems, respectively, had increased compared to five to ten years ago. FGDs and KIIs respondents were also reported the same.</p> <p>Conclusions</p> <p>Respondents had clear perceptions about changes in heat, cold and rainfall that had occurred over the last five to ten years. Local perceptions of climate variability (CV) included increased heat, overall warmer winters, reduced rainfall and fewer floods. The effects of CV were mostly negative in terms of means of living, human health, agriculture and overall livelihoods. Most local perceptions on CV are consistent with the evidence regarding the vulnerability of Bangladesh to CC. Such findings can be used to formulate appropriate sector programs and interventions. The systematic collection of such information will allow scientists, researchers and policy makers to design and implement appropriate adaptation strategies for CC in countries that are especially vulnerable.</p

Integrated 3D facies modeling of the Mangahewa Formation, Maui Gas Field, Taranaki Basin, New Zealand

Abstract 3D seismic data, well logs, core-based lithofacies and photographs have been combined to interpret and model the depositional facies of the Mangahewa Formation of the Maui Gas Field, Taranaki Basin, New Zealand. The primary objective of the study is to generate a robust facies model for the Middle to Late Eocene (47–37 Ma) Mangahewa Formation of the field. The facies model has included eighteen depositional facies spatially distributed over the gas field. These facies are further subgrouped into three broad depositional facies associations, namely marginal marine, shallow marine and offshore environment. We have identified that marginal marine is the most dominant facies association (64%) within the model. The model visualizes estuarine and shoreface sand geobodies dominating over other facies within the model. Both geobodies comprise over 40% of all the facies interpreted in the field. The entire modeling process involves a novel stochastic approach using unique workflow that follows 3D gridding, coding of the facies classes and multiple iterations over the interpreted facies. The model therefore realistically visualizes potential facies responsible for “good”-quality reservoir sands in the Mangahewa Formation with possible retrogradation from older to younger succession

Serological and Molecular Evidence of Q Fever in Domestic Ruminants in Bangladesh

The objective of this study was to know the herd and animal level prevalence of Q fever in domestic ruminants in some selected districts in Bangladesh. Randomly collected 111 bulk milk and 94 sera samples of cattle, sheep, and goats were tested by indirect ELISA (iELISA). DNA extracted from 23 aborted fetal membranes was analyzed by real time (rt) PCR. The positive cut-off value of iELISA in bulk milk and individual animal sera was ≥30% and ≥40%, respectively. The overall herd level prevalence of Q fever in dairy cattle was 15.6%. The prevalence of Q fever in dairy cattle was significantly higher in Sirajganj in comparison to Satkhira District (P<0.01). The overall seroprevalence of Q fever in domestic ruminants was 5.06%. Although statistically insignificant, the seroprevalence of Q fever was relatively higher in sheep (9.52%) in comparison to goats (3.33%) and cattle (3.57%). Out of 23 aborted fetal membranes, only one sheep placenta was positive in rt PCR. Q fever is present in all of the three important species of domestic ruminants in Bangladesh. It may have some role in sheep abortion as the seroprevalence is relatively higher and also one sheep placenta is rt PCR positive

Green synthesis of zinc oxide nanoparticles using Cocos nucifera leaf extract: characterization, antimicrobial, antioxidant and photocatalytic activity

Zinc oxide nanoparticles (ZnO NPs) have been successfully prepared using Cocos nucifera leaf extract and their antimicrobial, antioxidant and photocatalytic activity investigated. The structural, compositional and morphological properties of the NPs were recorded and studied systematically to confirm the synthesis. The aqueous suspension of NPs showed an ultraviolet–visible (UV–Vis) absorption maxima of 370 nm, indicating primarily its formation. X-ray diffraction analysis identified the NPs with a hexagonal wurtzite structure and an average particle size of 16.6 nm. Fourier transform infrared analysis identified some biomolecules and functional groups in the leaf extract as responsible for the encapsulation and stabilization of ZnO NPs. Energy-dispersive X-ray analysis showed the desired elemental compositions in the material. A flower-shaped morphology of ZnO NPs was observed by scanning electron microscopy, with a grain size of around 15 nm. The optical properties of the NPs were studied by UV–Vis spectroscopy, and the band gap was calculated as 3.37 eV. The prepared ZnO NPs have demonstrated antimicrobial activity against T. harzianum and S. aureus, with a zone of inhibition of 14 and 10 mm, respectively. The photocatalytic behaviour of ZnO NPs showed absorbance degradation at around 640 nm and it discoloured methylene blue dye after 1 h, with a degradation maximum of 84.29%. Thus, the prepared ZnO NPs could potentially be used in antibiotic development and pharmaceutical industries, and as photocatalysts

Rooftop PV or Hybrid Systems and Retrofitted Low-E Coated Windows for Energywise and Self-Sustainable School Buildings in Bangladesh

The electricity crisis is a common issue in Bangladesh; however, recently the electricity scenario has been getting worse due to various reasons including power generation and distribution all over the country. Meanwhile, the large number of people requires a huge amount of energy which is not possible to be met by the national grid due to the limited power generation from different plants. Among all renewable energy sources, the solar photovoltaics (PV) system is the best choice as a generation source, either off-grid or with a grid-tied connection, to reduce the pressure on the national grid. In Bangladesh, there are more than 175,000 schools, and it is possible to generate a huge amount of renewable (solar) power to supply all the schools by using rooftop PV systems. We propose a new approach that combines solar energy harvesting and savings to make the schools self-sufficient and energywise. We performed a Hybrid Optimization Model for Multiple Energy Resources (HOMER) pro simulation and find that it was possible to generate approximately 200 megawatts (MW) of power. We conducted a feasibility study on generating power from rooftop PV systems on school buildings and reduced the power consumption using retrofitted thin-film-coated glass by around 16–20% per day depending on the school size, which can help the national power grid system by either making all the schools off-grid or grid-connected to supply power to the national grid. In addition, we perform a HelioScope simulation to investigate the maximum upscaling of PV sizing for the rooftops of school buildings in Bangladesh to realize how to make each school a mini solar power station in the future. The HelioScope simulation performance showed that it was possible to generate approximately 96,993 kWh per year from one school building