High Prevalence of Vitamin D Deficiency among Bangladeshi Children: An Emerging Public Health Problem

Background: Recent studies suggested that vitamin D deficiency among children is widespread worldwide. Most of the Asian countries are suffering from high prevalence of vitamin D deficiency, especially in children. However, the vitamin D deficiency of Bangladeshi children has not been investigated yet. The objective of the study was to assess the prevalence of vitamin D deficiency among children in Dhaka city, Bangladesh. Methods: A cross-sectional study was designed. Children aged 0 month to 16 years attended Pediatrics’ clinics with minor illness were conveniently recruited. After obtaining informed written consent, venous blood was taken and serum 25(OH)D levels were determined by direct enzyme-linked immunosorbent assay. Descriptive statistics were performed for age, sex, biochemical parameters. Socio-economic status (SES) was estimated using a wealth index, producing a weighted score. Scores were categorized into quintiles, with category 1 representing the poorest and category 5 the richest. Serum 25(OH)D was categorized: deficient as Results: 31.88% children of 0 - 1 year had deficient serum 25(OH)D level and 52.17% children had insufficient level. Among 2 - 5 years’ group, 38.16% were deficient and 50% were insufficient. Among the 6 - 11 years group, 41.02% were deficient and 52.56% were insufficient. Among 12 - 16 years group, 46.75% were deficient and 51.95% were insufficient. That means, serum 25-hydroxyvitamin D deficiency and insufficiency rate is found very high among Bangladeshi children. Conclusions: The prevalence of vitamin D deficiency and insufficiency among children in Bangladesh is high. The study recommended that vitamin D supplementation in Bangladeshi children should be formally launched from first day of birth up to adolescence.

Reproductive Isolating Mechanisms in the Bangladesh Coastal Bullfrog Hoplobatrachus litoralis and Its Congeneric Species Revealed by Crossing Experiments and Examination on Spermatogenesis of the Hybrids

To elucidate reproductive isolating mechanisms in the Bangladesh coastal bullfrog Hoplobatrachus litoralis and its congeneric species, we performed crossing experiments using three species： H. litoralis, H. tigerinus and H. rugulosus. In addition, we conducted histological observations on spermatogenesis of the hybrids. The reciprocal hybrids between H. litoralis and H. tigerinus developed normally with somewhat lower viability at the metamorphosis stage compared with the controls. Most of the metamorphosed frogs became mature. On the other hand, almost all hybrids between female H. rugulosus and male H. litoralis or H. tigerinus died of underdevelopment at the tadpole stage, and only a few hybrids metamorphosed normally and survived to maturity. The inner structures of the testes of the control H. litoralis and H. tigerinus were completely normal, with seminiferous tubules filled with compact bundles of normal spermatozoa. Those of the reciprocal hybrids between H. litoralis and H. tigerinus were almost normal or slightly abnormal, with seminiferous tubules that contained pycnotic nuclei in addition to normal bundles of normal spermatozoa, which demonstrates slight abnormalities in spermatogenesis. In contrast, the hybrids between female H. rugulosus and male H. litoralis or H. tigerinus had no bundles of spermatozoa nor spermatids in the seminiferous tubules, which indicates entirely abnormal spermatogenesis. Meiotic chromosome figures in the reciprocal hybrids between H. litoralis and H. tigerinus showed slight abnormalities, with the occurrence of univalents and increase of rod-shaped bivalents. These results indicate that H. litoralis and H. tigerinus are not isolated from each other by hybrid inviability nor by hybrid sterility, although the hybrids showed somewhat abnormal spermatogenesis in hybrids and that H. rugulosus is isolated from both H. litoralis and H. tigerinus by incomplete hybrid inviability and complete hybrid sterility.

Age-Structured Population Projection of Bangladesh by Using a Partial Differential Model with Quadratic Polynomial Curve Fitting

In this paper, the age-specific population of Bangladesh based on a linear first order (hyperbolic) partial differential equation which is known as Von-Foerster Equation is studied. Applying quadratic polynomial curve fitting, the total population and population density of Bangladesh are projected for the years 2001 to 2050 based on the explicit upwind finite difference scheme for the age-structured population model based on given data (source: BBS & ICDDR, B) for initial value in the year 2001. For each age-group, the future birth rates and death rates are estimated by using quadratic polynomial curve fitting of the data for the years 2001 to 2012. Quadratic polynomial curve fitting is also used for the boundary value as the (0 - 4) age-group population based on the population size of the age-group for the years 2001 to 2012.

The Ecotoxicological Effects of Microplastics on Primary Producers in the Marine Environment

Plastic debris is an emerging environmental threat all over the world.But its effect and distribution in the marine ecosystem is barely known.Microplastics abundance in the marine vegetated area is about 2 to 3 times higher than the bare site in the ocean.Although seagrass meadows trap huge amount of microplastics over the ocean floor,a considerable amount of microplastics are also sink incorporating with the marine aggregates from the epipelagic zone of the ocean.Scavenging of microplastics by diatom aggregation decreases the sinking rate of them rather than cryptophyte.As we know,marine snow is the leading carbon source for zoobenthos,but the ubiquitous presence of microplastics damages cell of different microalgae which may alter the food webs of marine ecosystems.Additionally,microplastics releases immense amount of dissolved organic carbons(DOC)in the surrounding seawater that stimulates the growth of heterotrophic microorganisms as well as their functional activity.Plastic debris result in outbreaks of disease in the marine environment and coral reefs are highly affected by it.When coral reef comes in contact with microplastics,the disease infestation rate of the reef increases massively.Three major disease viz.,skeletal eroding band,white syndrome and black band of coral reef causes approximately 46%of reef mortality due to microplastics consumption.Due to complex structure and size,the corals accumulates huge amount of microplastics that increases growth of pathogens by hampering the coral immune system.Existing scientific evidence presents that exposure of microplastics in aquatic environments triggers a wide variety of toxic insult from feeding disruption to reproductive performance,disturbances in energy metabolism throughout the ocean.The present review focused on the ecotoxicological effect of microplastics on primary producers of ocean,its uptake,accumulation,and excretion,and its probable toxicity with risk assessment approaches.

Lax-Friedrich Scheme for the Numerical Simulation of a Traffic Flow Model Based on a Nonlinear Velocity Density Relation

A fluid dynamic traffic flow model based on a non-linear velocity-density function is considered. The model provides a quasi-linear first order hyperbolic partial differential equation which is appended with initial and boundary data and turns out an initial boundary value problem (IBVP). A first order explicit finite difference scheme of the IBVP known as Lax-Friedrich’s scheme for our model is presented and a well-posedness and stability condition of the scheme is established. The numerical scheme is implemented in order to perform the numerical features of error estimation and rate of convergence. Fundamental diagram, density, velocity and flux profiles are presented.

Estimation of the Stability of a River Island and Its Suitability for Installing Solar Based Power Plant in Bangladesh

Bangladesh, situated in tropical and subtropical regions, receives significant amount of solar energy, making it an ideal location for solar energy production. However, determining suitable sites in the country for solar based power plant establishment turns out to be a difficult task given its dense population. This study aims to the identification of such a potential site by assessing the stability of the Jamuna river Island to be proposed as a site for developing solar based power plant. The research concentrates on Fulchhari union of Gaibandha district, one of the three major islands in the Jamuna river, utilizing two GIS-based multi-criteria decision-making (MCDM) techniques. One is Digital Shoreline Analysis System (DSAS) for stability analysis, and another is Analytical Hierarchy Process (AHP) for suitability evaluation. For the stability analysis of the island, Landsat satellite imagery of 1990, 1995, 2000, 2005, 2010, 2015 and 2020 covering a long term of 30 years period were investigated. Based on average change rates, the bankline of the island was divided into 2 accretion zones in the south and south-eastern direction, and 8 erosion zones. Along with the bankline changes, climatological, geomorphological, and environmental factors have been adopted to modeling process for suitability analysis. The optimal locations for solar based power plants have been demonstrated by a suitability map, where high and standard potential area is about 60% of the area of Fulchhari union. Production may be enhanced up to 5 times more with the consideration of utilizing the moderate optimum zone.

Predictive car-following scheme for improving traffic flows on urban road networks

Driving behavior is one of the main reasons that causes bottleneck on the freeway or restricts the capacity of signalized intersections.This paper proposes a car-following scheme in a model predictive control(MPC)framework to improve the traffic flow behavior,particularly in stopping and speeding up of individual vehicles in dense urban traffic under a connected vehicle(CV)environment.Using information received through vehicle-to-vehicle(V2V)communication,the scheme predicts the future states of the preceding vehicle and computes the control input by solving a constrained optimization problem considering a finite future horizon.The objective function is to minimize the weighted costs due to speed deviation,control input,and unsafe gaps.The scheme shares the planned driving information with the following vehicles so that they can make better cooperative driving decision.The proposed car-following scheme is simulated in a typical driving scenario with multiple vehicles in dense traffic that has to stop at red signals in multiple intersections.The speeding up or queue clearing and stopping characteristics of the traffic using the proposed scheme is compared with the existing car-following scheme through numerical simulation.

An AI-driven microstructure optimization framework for elastic properties of titanium beyond cubic crystal systems

Materials design aims to identify the material features that provide optimal properties for various engineering applications,such as aerospace,automotive,and naval.One of the important but challenging problems for materials design is to discover multiple polycrystalline microstructures with optimal properties.This paper proposes an end-to-end artificial intelligence(AI)-driven microstructure optimization framework for elastic properties of materials.In this work,the microstructure is represented by the Orientation Distribution Function(ODF)that determines the volume densities of crystallographic orientations.The framework was evaluated on two crystal systems,cubic and hexagonal,for Titanium(Ti)in Joint Automated Repository for Various Integrated Simulations(JARVIS)database and is expected to be widely applicable for materials with multiple crystal systems.The proposed framework can discover multiple polycrystalline microstructures without compromising the optimal property values and saving significant computational time.