A study was conducted to investigate the accumulation and distribution of arsenic in different fractions of rice grain (
Oryza sativa L.) collected from arsenic affected area of Bangladesh. The ...agricultural soil of study area has become highly contaminated with arsenic due to the excessive use of arsenic-rich underground water (0.070
±
0.006
mg
l
−1,
n
=
6) for irrigation. Arsenic content in tissues of rice plant and in fractions of rice grain of two widely cultivated rice varieties, namely BRRI dhan28 and BRRI hybrid dhan1, were determined. Regardless of rice varieties, arsenic content was about 28- and 75-folds higher in root than that of shoot and raw rice grain, respectively. In fractions of parboiled and non-parboiled rice grain of both varieties, the order of arsenic concentrations was; rice hull
>
bran-polish
>
brown rice
>
raw rice
>
polish rice. Arsenic content was higher in non-parboiled rice grain than that of parboiled rice. Arsenic concentrations in parboiled and non-parboiled brown rice of BRRI dhan28 were 0.8
±
0.1 and 0.5
±
0.0
mg
kg
−1 dry weight, respectively while those of BRRI hybrid dhan1 were 0.8
±
0.2 and 0.6
±
0.2
mg
kg
−1 dry weight, respectively. However, parboiled and non-parboiled polish rice grain of BRRI dhan28 contained 0.4
±
0.0 and 0.3
±
0.1
mg
kg
−1 dry weight of arsenic, respectively while those of BRRI hybrid dhan1 contained 0.43
±
0.01 and 0.5
±
0.0
mg
kg
−1 dry weight, respectively. Both polish and brown rice are readily cooked for human consumption. The concentration of arsenic found in the present study is much lower than the permissible limit in rice (1.0
mg
kg
−1) according to WHO recommendation. Thus, rice grown in soils of Bangladesh contaminated with arsenic of 14.5
±
0.1
mg
kg
−1 could be considered safe for human consumption.
Staphylococcus aureus is responsible for large numbers of hospital-related and community-acquired infections. In this study, we investigated the presence of S. aureus and methicillin-resistant S. ...aureus (MRSA) in 100 samples from animals (55 cattle, 36 dogs, and 9 cats) and 150 samples from hospitalized human patients. The samples were collected from healthy and diseased animals and from diseased humans and included milk, wound swab, pus, exudates, nasal swab and diabetic ulcer. Initially, S. aureus was isolated and identified by colony morphology, Gram staining, and biochemical tests (catalase and coagulase tests). The S. aureus-positive samples were examined by polymerase chain reaction (PCR) to determine their MRSA status.
Of the 100 animal samples, 29 were positive for S. aureus. Four samples (13.8%) from dogs were MRSA-positive, but samples from cattle and cats were MRSA-negative. Of the 150 human samples we collected, 64 were S. aureus-positive and, of these, 34 (53.1%) were MRSA-positive. Most (28%) of the MRSA samples were isolated from surgical wound swabs, followed by the pus from skin infections (11%), exudates from diabetic ulcers (6%), exudates from burns (4%), and aural swabs (3%). By contrast, a low MRSA detection rate (n = 4) was seen in the non-human isolates, where all MRSA bacteria were isolated from nasal swabs from dogs. The antimicrobials susceptibility testing results showed that S. aureus isolates with mecA genes showed resistance to penicillin (100%), oxacillin (100%), erythromycin (73.5%), ciprofloxacin (70.6%), and gentamicin (67.7%). The lowest resistance was found against ceftazidime, and no vancomycin-resistant isolates were obtained.
We detected S. aureus and MRSA in both human and canine specimens. Isolates were found to be resistant to some of the antimicrobials available locally. MRSA carriage in humans and animals appears to be a great threat to effective antimicrobials treatment. The prudent use of antimicrobials will reduce the antimicrobial resistance. Our findings will help to find the most appropriate treatment and to reduce antimicrobial resistance in the future by implementing prudent use of antimicrobials. Further studies are required to better understand the epidemiology of MRSA human-animal inter-species transmission in Bangladesh.
We conducted a systematic review and meta‐analysis of population‐based cohort studies of maternal body mass index (BMI) and risk of adverse birth and health outcomes in low‐ and middle‐income ...countries. PubMed, Embase, CINAHL and the British Nursing Index were searched from inception to February 2014. Forty‐two studies were included. Our study found that maternal underweight was significantly associated with higher risk of preterm birth (odds ratio OR, 1.13; 95% confidence interval CI, 1.01–1.27), low birthweight (OR, 1.66; 95% CI, 1.50–1.84) and small for gestational age (OR, 1.85; 95% CI, 1.69–2.02). Compared with mothers with normal BMI, overweight or obese mothers were at increased odds of gestational diabetes, pregnancy‐induced hypertension, pre‐eclampsia, caesarean delivery and post‐partum haemorrhage. The population‐attributable risk (PAR) indicated that if women were entirely unexposed to overweight or obesity during the pre‐pregnancy or early pregnancy period, 14% to 35% fewer women would develop gestational diabetes, pre‐eclampsia or pregnancy‐induced hypertension in Brazil, China, India, Iran or Thailand. The highest PAR of low birthweight attributable to maternal underweight was found in Iran (20%), followed by India (18%), Thailand (10%) and China (8%). Treatment and prevention of maternal underweight, overweight or obesity may help reduce the burden on maternal and child health in developing countries.
In recent years Deep Learning has brought about a breakthrough in Medical Image Segmentation. In this regard, U-Net has been the most popular architecture in the medical imaging community. Despite ...outstanding overall performance in segmenting multimodal medical images, through extensive experimentations on some challenging datasets, we demonstrate that the classical U-Net architecture seems to be lacking in certain aspects. Therefore, we propose some modifications to improve upon the already state-of-the-art U-Net model. Following these modifications, we develop a novel architecture, MultiResUNet, as the potential successor to the U-Net architecture. We have tested and compared MultiResUNet with the classical U-Net on a vast repertoire of multimodal medical images. Although only slight improvements in the cases of ideal images are noticed, remarkable gains in performance have been attained for the challenging ones. We have evaluated our model on five different datasets, each with their own unique challenges, and have obtained a relative improvement in performance of 10.15%, 5.07%, 2.63%, 1.41%, and 0.62% respectively. We have also discussed and highlighted some qualitatively superior aspects of MultiResUNet over classical U-Net that are not really reflected in the quantitative measures.
A glass house experiment was conducted to investigate the effect of soil arsenic on photosynthetic pigments, chlorophyll-a and -b, and their correlations with rice yield and growth. The experiment ...was designed with three replications of six arsenic treatments viz. control, 10, 20, 30, 60, 90
mg of As
kg
−1 soil. Arsenic concentration in initial soil, to which the above mentioned concentrations of arsenic were added, was 6.44
±
0.24
mg
kg
−1. Both chlorophyll-a and -b contents in rice leaf decreased significantly (
p
<
0.05) with the increase of soil arsenic concentrations. No rice plant survived up to maturity stage in soil treated with 60 and 90
mg of As
kg
−1. The highest chlorophyll-a and -b contents were observed in control treatment (2.62
±
0.24 and 2.07
±
0.14
mg
g
−1 were the average values of chlorophyll-a and -b, respectively of the five rice varieties) while 1.50
±
0.20 and 1.04
±
0.08
mg
g
−1 (average of five rice varieties) of chlorophyll-a and -b, respectively were the lowest. The content of photosynthetic pigments in these five rice varieties did not differ significantly (
p
>
0.05) from each other in control treatment though they differed significantly (
p
<
0.05) from each other in 30
mg of As
kg
−1 soil treatment. Among the five rice varieties, chlorophyll content in BRRI dhan 35 was found to be mostly affected with the increase of soil arsenic concentration while BRRI hybrid dhan 1 was least affected. Well correlations were observed between chlorophyll content and rice growth and yield suggesting that arsenic toxicity affects the photosynthesis which ultimately results in the reduction of rice growth and yield.
The objective of this work was to produce renewable liquid fuel (bio-oil) from locally produced bagasse by pyrolysis in a batch feeding and fixed bed reactor. The experiments were performed at ...different temperatures ranging from 300 to 600
°C. The bio-oil was collected from two condensers of different temperatures and defined as oil-1 and oil-2. The maximum total yield of bio-oil was found to be 66.0
wt% based on bagasse. The carbon based non-condensable gases were CO, CO
2, methane, ethane, ethene, propane and propene. The density and viscosity of oil-1 were found to be 1130
kg/m
3 and 19.32 centipoise and that were 1050
kg/m
3 and 4.25 centipoise for oil-2, respectively. The higher heating values (HHV) of them were 17.25 and 19.91
MJ/kg, respectively. The pH of the bio-oils was found to be around 3.5 and 4.5 for oil-1 and oil-2, respectively. The water, solid and ash contents of oil-1 and oil-2 were determined and found to be around 15, 0.02 and 0.03
wt% and 11, 0.01 and 0.02
wt%, respectively based on bagasse.
•Cd-free CZTS solar cells with improved photo-conversion efficiency.•Incorporation of SnS HTL into CZTS-based solar cells reduces the VOC deficit.•TiO2 ETL could be a good alternative to CdS in ...CZTS-based solar cells.•Metals like Au, Ir, Ni & W can be used as back metal contact materials.
Cu2ZnSnS4 chalcogenide semiconductor is a very promising absorber material for solar cells and no longer fulfilled its realistic goals due to the possible challenge of defect-free fabrication, non-optimized buffer layer alignment and device configuration. In this article, we proposed a new planner structure defined as (SnS/CZTS/TiO2/ITO) using Ni and Al as a back and front contact materials, respectively, and simulated its photovoltaic (PV) performance using SCAPS-1D. In the simulation, defect densities were added to each layer and the interface between the buffer layer and the absorber layer. This work demonstrated the promising role of SnS HTL and TiO2 ETL in reducing the Voc deficit of CZTS-based solar cells by forming more favourable band alignment with the absorber layer, reducing non-radiative recombination at the interfaces. In response to changes in the material properties of different layers (such as thickness, carrier concentration, defect density), working temperature, and back contact metal work function, the PV performance of the new architecture for CZTS solar cells was investigated and optimized. The study of PV performance optimization revealed that a relatively thicker absorber layer with low carrier concentration showed better PV performances, while ETL and HTL with a thinner and higher carrier concentration are required to enhance PV performances. Power conversion efficiency of >30%, Voc of >1.09 V, Jsc of >32 mA/cm2 and FF of >87% was predicted for CZTS solar cells with the new architecture. The findings of this study suggest that SnS and TiO2 are expected to become HTL and ETL, respectively, for fabricating low cost, high efficiency, and Cd-free CZTS-based heterojunction solar cell.
Malnutrition in children under five years remains a significant problem in Bangladesh, despite substantial socio-economic progress and a decade of interventions aimed at improving it. Although ...several studies have been conducted to identify the important risk factors of malnutrition, none of them assess the role of low birth weight (LBW) despite its high prevalence (36%). This study examines the association between LBW and malnutrition using data from the Bangladesh Demographic and Health Survey (BDHS) 2011 and provides practical guidelines for improving nutritional status of children.
Malnutrition in children is measured in terms of their height-for-age, weight-for-height, and weight-for-age. Children whose Z-scores for either of these indices are below two standard deviations (-2SD) from median of WHO's reference population are considered as stunted, wasted or underweight, respectively. The association between malnutrition and LBW was investigated by calculating adjusted risk-ratio (RR), which controls for potential confounders such as child's age and sex, mother's education and height, length of preceding-birth-interval, access to food, area of residence, household socio-economic status. Adjusted RR was calculated using both Cochran-Mantel-Haenszel approach and multivariable logistic regression models controlling for confounder.
The prevalence of malnutrition was markedly higher in children with LBW than those with normal birth-weights (stunting: 51% vs 39%; wasting: 25% vs 14% and underweight: 52% vs 33%). While controlling for the known risk factors, children with LBW had significantly increased risk of becoming malnourished compared to their counter part with RR 1.23 (95% CI:1.16-1.30), 1.71 (95% CI:1.53-1.92) and 1.47 (95% CI: 1.38-1.56) for stunting, wasting and underweight, respectively. The observed associations were not modified by factors known to reduce the prevalence of malnutrition, such as higher education of mother, better household socio-economic conditions and longer birth-interval.
Higher education of mother, better household socio-economic conditions and prolonged birth intervals alone are not sufficient in bringing about substantial reductions in prevalence of child malnutrition in Bangladesh. Targeted interventions should be designed to reduce prevalence of LBW in addition to improving mother's education and other socio-demographic conditions.
The protection against emerging SARS-CoV-2 variants by pre-existing antibodies elicited due to the current vaccination or natural infection is a global concern. We aimed to investigate the rate of ...SARS-CoV-2 infection and its clinical features among infection-naïve, infected, vaccinated, and post-infection-vaccinated individuals. A cohort was designed among icddr,b staff registered for COVID-19 testing by real-time reverse transcriptase-polymerase chain reaction (rRT-PCR). Reinfection cases were confirmed by whole-genome sequencing. From 19 March 2020 to 31 March 2021, 1644 (mean age, 38.4 years and 57% male) participants were enrolled; where 1080 (65.7%) were tested negative and added to the negative cohort. The positive cohort included 750 positive patients (564 from baseline and 186 from negative cohort follow-up), of whom 27.6% were hospitalized and 2.5% died. Among hospitalized patients, 45.9% had severe to critical disease and 42.5% required oxygen support. Hypertension and diabetes mellitus were found significantly higher among the hospitalised patients compared to out-patients; risk ratio 1.3 and 1.6 respectively. The risk of infection among positive cohort was 80.2% lower than negative cohort (95% CI 72.6-85.7%; p < 0.001). Genome sequences showed that genetically distinct SARS-CoV-2 strains were responsible for reinfections. Naturally infected populations were less likely to be reinfected by SARS-CoV-2 than the infection-naïve and vaccinated individuals. Although, reinfected individuals did not suffer severe disease, a remarkable proportion of naturally infected or vaccinated individuals were (re)-infected by the emerging variants.
Arsenic concentration in raw rice is not only the determinant in actual dietary exposure. Though there have been many reports on arsenic content in raw rice and different tissues of rice plant, ...little is known about arsenic content retained in cooked rice after being cooked following the traditional cooking methods employed by the people of arsenic epidemic areas. A field level experiment was conducted in Bangladesh to investigate the influence of cooking methods on arsenic retention in cooked rice. Rice samples were collected directly from a severely arsenic affected area and also from an unaffected area, to compare the results. Rice was cooked according to the traditional methods employed by the population of subjected areas. Arsenic concentrations were 0.40
±
0.03 and 0.58
±
0.12 mg/kg in parboiled rice of arsenic affected area, cooked with excess water and 1.35
±
0.04 and 1.59
±
0.07 mg/kg in gruel for BRRI dhan28 and BRRI hybrid dhan1, respectively. In non-parboiled rice, arsenic concentrations were 0.39
±
0.04 and 0.44
±
0.03 mg/kg in rice cooked with excess water and 1.62
±
0.07 and 1.74
±
0.05 mg/kg in gruel for BRRI dhan28 and BRRI hybrid dhan1, respectively. Total arsenic content in rice, cooked with limited water (therefore gruel was absorbed completely by rice) were 0.89
±
0.07 and 1.08
±
0.06 mg/kg (parboiled) and 0.75
±
0.04 and 1.09
±
0.06 mg/kg (non-parboiled) for BRRI dhan28 and BRRI hybrid dhan1, respectively. Water used for cooking rice contained 0.13 and 0.01 mg of As/l for contaminated and non-contaminated areas, respectively. Arsenic concentrations in cooked parboiled and non-parboiled rice and gruel of non-contaminated area were significantly lower (
p
<
0.01) than that of contaminated area. The results imply that cooking of arsenic contaminated rice with arsenic contaminated water increases its concentration in cooked rice.
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