Detection of Campylobacter spp. in farmed sheep in Mymensingh division of Bangladesh: Prevalence, risk factors, and antimicrobial susceptibility status.

Background and Aim: Campylobacter infections in sheep may be asymptomatic or cause enteritis, ileitis, infertility, and abortion. Thus, this study aimed to estimate the prevalence of Campylobacter spp. in farming sheep and to detect risk factors, molecular patterns, and antimicrobial susceptibility status of these pathogens. Materials and Methods: Four hundred and eight fecal samples were collected from 12 flocks in the Mymensingh and Sherpur districts. Samples were tested by both basic (culture and biochemical tests) and molecular (initially 16S rRNA and later hipO gene-based polymerase chain reaction). Furthermore, the antimicrobial susceptibility status of Campylobacter jejuni was confirmed using disk diffusion. Flock- and animal-level data were captured using semi-structured interviews with farm owners under bivariate and multivariate logistic regression analyses to confirm the risk factors for Campylobacter-positive status. Results: The prevalence of C. jejuni staining at the animal and flock levels was 8.82% (36/408) and 66.70% (8/12), respectively. The age of sheep was identified as an important risk factor. Up to 1 year of age, sheep were 3.78 times more likely to be infected with C. jejuni (95% confidence interval: 1.0736-13.3146, p = 0.038). Of the 36 isolates of C. jejuni, all were found to be fully susceptible (100%) to gentamicin and ciprofloxacin. In this study, three antimicrobial agents, oxytetracycline, azithromycin, and ceftriaxone, were fully resistant (100%). The majority of isolates were resistant to a combination of 4-6 antimicrobial agents. Conclusion: The present study highlights the predominant maintenance of zoonotic Campylobacter species in sheep, and their burden on human health is enormous. Therefore, environmental, animal, and human health needs to be focused under a One Health lens to mitigate the occurrence of Campylobacter in farm settings and to prevent further introduction to animals and humans.

Recycled Household Ash in Rice Paddies of Bangladesh for Sustainable Production of Rice Without Altering Grain Arsenic and Cadmium.

In Bangladesh most agronomic biomass (straw, husk, dried dung) is burnt for domestic cooking use. Consequently, the soil is continuously stripped of mineral nutrients and carbon (C) substrate. Here we investigate if recycling of household ash (ash) as fertilizer can sustainably improve soil fertility as well as minimise accumulation of toxic elements (As, Cd) in rice grain. Large scale field trials across two geographic regions (Barind, Madhupur) and two seasons (wet, dry) and with application of 3 fertiliser treatments (NPKS, ash, NPKS + ash) were conducted. At the end of each season, the impact of region*season*treatment on soil microbial comunities, rice yield, and grain quality (As, Cd, nutrient elements) was assessed. When compared to conventional field application rates of NPKS (control), application of ash boosted rice yield by circa. 20% in both regions during wet and dry season, with no effect on rice grain carcinogenic inorganic arsenic (iAs), dimethylarsonic acid (DMA) or cadmium (Cd), but with potential to increase zinc (Zn). For soil microbial communities, a significant region and season effect as well as correlation with elements in rice grain was observed, amongst these Cd, Zn, iAs and DMA. This study illustrates that application of ash can reduce the requirement for expensive chemical fertiliser, whilst at the same time increasing rice yield and maintaining grain quality, making farming in Bangladesh more sustainable and productive. The study also implies that the combined impact of region, season, and soil microbes determines accumulation of elements in rice grain. Supplementary Information: The online version contains supplementary material available at 10.1007/s12403-023-00539-y.

Development of DynamicMC for PHITS Monte Carlo package.

Previously, we have developed DynamicMC for modeling relative movement of Oak Ridge National Laboratory phantom in a radiation field for the Monte Carlo N-Particle package (Health Physics. 2023,124(4):301-309). Using this software, three-dimensional dose distributions in a phantom irradiated by a certain mono-energetic (Mono E) source can be deduced through its graphical user interface. In this study, we extended DynamicMC to be used in combination with the Particle and Heavy Ion Transport code System (PHITS) by providing it with a higher flexibility for dynamic movement for an anthropomorphic phantom. For this purpose, we implemented four new functions into the software, which are (1) to generate not only Mono E sources but also those having an energy spectrum of an arbitrary radioisotope (2) to calculate the absorbed doses for several radiologically important organs (3) to automatically average the calculated absorbed doses along the path of the phantom and (4) to generate user-defined slab shielding materials. The first and third items utilize the PHITS-specific modalities named radioisotope-source and sumtally functions, respectively. The computational cost and complexity can be dramatically reduced with these features. We anticipate that the present work and the developed open-source tools will be in the interest of nuclear radiation physics community for research and teaching purposes.

Comparative Efficacy of Foliar Plus Soil Application of Urea versus Conventional Application Methods for Enhanced Growth, Yield, Agronomic Efficiency, and Economic Benefits in Rice.

The experiment was conducted at the research field, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur from December 2017 to May 2018 to find out the best treatment of foliar application of urea on the growth and yield of boro rice cv. BRRI dhan28. The experiment consisted of 10 treatments, laid out in a randomized complete block design in triplicate. The recommended doses (RD) of urea, TSP, MOP, gypsum, ZnSO4, and borax were applied during land preparation except for urea at 250, 75, 100, 75, 7, and 5 kg ha-1, respectively, where urea was applied as per treatment specification. The results revealed that the application of N fertilizer as foliage along with soil significantly influenced the growth, plant characteristics, and yield of BRRI dhan28. There was no significant difference between T8 (70% in soil and 10% as foliage) and T9 (100% in soil) treatment regarding the maximum panicle length (21.43 and 20.71 cm), fertile grains (117.40 and 113.30), total grains (134.40 and 130.97), 1000-grain weight (24.56 and 23.56 g), grain yield (5.91 and 5.74 t ha-1), straw yield (7.83 and 7.92 t ha-1), biological yield (13.74 and 13.66 t ha-1), and harvest index (43.01 and 42.02%), respectively, in this study. These results indicated that N fertilization as direct soil application (70%) and as foliage application (10%), i.e., 80% N fertilization, produced the highest grain yield and major yield traits which we received by 100% N fertilization as soil that was practiced traditionally by the farmers. The effect of overfertilization (T10) was not positive, producing the highest number of noneffective tillers and sterile grains (nonfilled grains). Therefore, it is possible to achieve an equivalent or more yield by saving 20% urea by the combination of soil (70%) and foliage (10%) application as compared to the traditional method of fertilizer application (100% in soil).

On the effectiveness of proton boron fusion therapy (PBFT) at cellular level.

The present work introduced a framework to investigate the effectiveness of proton boron fusion therapy (PBFT) at the cellular level. The framework consisted of a cell array generator program coupled with PHITS Monte Carlo package with a dedicated terminal-based code editor that was developed in this work. The framework enabled users to model large cell arrays with normal, all boron, and random boron filled cytoplasm, to investigate the underlying mechanism of PBFT. It was found that alpha particles and neutrons could be produced in absence of boron mainly because of nuclear reaction induced by proton interaction with 16O, 12C and 14N nuclei. The effectiveness of PBFT is highly dependent on the incident proton energy, source size, cell array size, buffer medium thickness layer, concentration and distribution of boron in the cell array. To quantitatively assess the effectiveness of PBFT, of the total energy deposition by alpha particle for different cases were determined. The number of alpha particle hits in cell cytoplasm and nucleus for normal and 100 ppm boron were determined. The obtained results and the developed tools would be useful for future development of PBFT to objectively determine the effectiveness of this treatment modality.

RadStat: An open-source statistical analysis tool for counts obtained by a GM counter.

The interaction of ionizing radiation with matter is a stochastic process and statistical analysis of such a process would be a crucial step in understanding radioactivity. Geiger-Müller (GM) counter is a widely used radiation detector used in nuclear radiation surveying, which produces counts upon exposure to a radioactive source. There are a variety of multi-purpose software that can be used to perform statistical analysis of measured counts from a GM counter. However, statistical analysis is a lengthy, error prone and time-consuming process, which gets more tedious when the number of measurements increases. In the present work, we have developed an open-source and easy-to-use graphical user interface (GUI) computer program named RadStat for statistical analysis of counts measured by a GM counter. RadStat has its own scripting syntaxes and bundled with gnuplot for quick visualization of output results. We believe the present open-source GUI program would be a useful tool for research and teaching of nuclear radiation physics.

Development of PHITS graphical user interface for simulation of positron emitting radioisotopes production in common biological materials during proton therapy.

The Monte Carlo (MC) method is a powerful tool for modeling nuclear radiation interaction with matter. A variety of MC software packages has been developed, especially for applications in radiation therapy. Most widely used MC packages require users to write their own input scripts for their systems, which can be a time consuming and error prone process and requires extensive user experience. In the present work, we have developed a graphical user interface (GUI) bundled with a custom-made 3D OpenGL visualizer for PHITS MC package. The current version focuses on modeling proton induced positron emitting radioisotopes, which in turn can be used for verification of proton ranges in proton therapy. The developed GUI program does not require extensive user experience. The present open-source program is distributed under GPLv3 license that allows users to freely download, modify, recompile and redistribute the program.

Cytokinin and gibberellic acid-mediated waterlogging tolerance of mungbean (Vigna radiata L. Wilczek).

BACKGROUND: Mungbean (Vigna radiata L. Wilczek) is one of the most important pulse crops, well-known for its protein-rich seeds. Growth and productivity are severely undermined by waterlogging. METHODS: In this study, we aim to evaluate how two promising phytohormones, namely cytokinin (CK) and gibberellic acid (GA3), can improve waterlogging tolerance in mungbean by investigating key morphological, physiological, biochemical, and yield-related attributes. RESULTS: Our results showed that foliar application of CK and GA3 under 5-day of waterlogged conditions improved mungbean growth and biomass, which was associated with increased levels of photosynthetic rate and pigments. Waterlogged-induced accumulation of reactive oxygen species and the consequently elevated levels of malondialdehyde were considerably reduced by CK and GA3 treatments. Mungbean plants sprayed with either CK or GA3 suffered less oxidative stress due to the enhancement of total phenolics and flavonoids levels. Improvement in the contents of proline and total soluble sugars indicated a better osmotic adjustment following CK and GA3 treatments in waterlogged-exposed plants. Most fundamentally, CK or GA3-sprayed waterlogged-stressed mungbean plants demonstrated better performance in the aforementioned parameters after the 15-day recovery period as compared to water-sprayed waterlogged-exposed plants. Our results also revealed that CK and GA3 treatments increased yield-associated features in the waterlogged-stressed plant. Here, both phytohormones are efficient in improving mungbean resistance to waterlogging. However, CK was found to be more effective. Overall, our findings suggested that CK or GA3 could be used for managing waterlogging-induced damage to mungbean and perhaps in other cash crops.

Proton range monitoring using 13N peak for proton therapy applications.

The Monte Carlo method is employed in this study to simulate the proton irradiation of a water-gel phantom. Positron-emitting radionuclides such as 11C, 15O, and 13N are scored using the Particle and Heavy Ion Transport Code System Monte Carlo code package. Previously, it was reported that as a result of 16O(p,2p2n)13N nuclear reaction, whose threshold energy is relatively low (5.660 MeV), a 13N peak is formed near the actual Bragg peak. Considering the generated 13N peak, we obtain offset distance values between the 13N peak and the actual Bragg peak for various incident proton energies ranging from 45 to 250 MeV, with an energy interval of 5 MeV. The offset distances fluctuate between 1.0 and 2.0 mm. For example, the offset distances between the 13N peak and the Bragg peak are 2.0, 2.0, and 1.0 mm for incident proton energies of 80, 160, and 240 MeV, respectively. These slight fluctuations for different incident proton energies are due to the relatively stable energy-dependent cross-section data for the 16O(p,2p2n)13N nuclear reaction. Hence, we develop an open-source computer program that performs linear and non-linear interpolations of offset distance data against the incident proton energy, which further reduces the energy interval from 5 to 0.1 MeV. In addition, we perform spectral analysis to reconstruct the 13N Bragg peak, and the results are consistent with those predicted from Monte Carlo computations. Hence, the results are used to generate three-dimensional scatter plots of the 13N radionuclide distribution in the modeled phantom. The obtained results and the developed methodologies will facilitate future investigations into proton range monitoring for therapeutic applications.

Arsenic dynamics in paddy soil under traditional manuring practices in Bangladesh.

Fertilization with organic matter (farm yard manure and/or rice straw) is thought to enhance arsenic (As) mobilization into soil porewaters, with subsequent As assimilation by rice roots leading to enhanced translocation to the grain. Here, interlinked experiments (field manuring and soil batch culture) were conducted to find the effect of organic matter at a field application rate practiced in Bangladesh (5 t/ha) on As mobilization in soil for paddies impacted by As contaminated groundwater irrigation, a widespread phenomenon in Bangladesh where the experiments were conducted. Total As concentration in a paddy soil (Sonargaon) ranged from 21.9 to 8.1 mg/kg down the soil profile and strongly correlated with TOC content. Arsenic, Fe, Mn, and DOC release into soil solution, and As speciation, are intimately linked to OM amendment, soil depth and temporal variation. Organic matter amendments lead to increased mobilization of As into both soil porewaters and standing surface waters. The As speciation in the porewater was dominated by inorganic As (Asi) (arsenite and arsenate), with traces amounts of methylated species (DMAV and MMAV) only being found with OM amendment. It was noted in field trials that OM fertilization greatly enhanced As mobility to surface waters, which may have major implications for the fate of As in paddy agronomic ecosystems.

Modifying the Parboiling of Rice to Remove Inorganic Arsenic, While Fortifying with Calcium.

Using village-based rice processing plants in rural Bangladesh, this study considered how parboiling rice could be altered to reduce the content of the carcinogen inorganic arsenic. Parboiling is normally conducted with rough rice (i.e., where the husk is intact) that is soaked overnight at ambient temperatures, and then either steamed or boiled for ∼10 min, followed by drying. Across 13 geographically dispersed facilities it was found that a simple alteration parboiling wholegrain, instead of rough rice, decreased the inorganic arsenic content by 25% ( P = 0.002) in the final polished grain. Also, parboiling wholegrain had little impact on milling quality of the final polished rice. The wholegrain parboiling approach caused statistically significant median enrichment of calcium, by 213%; and a reduction in potassium, by 40%; with all other nutrient elements tested being unaffected. Milled parboiled rough rice had an enriched inorganic arsenic compared to nonparboiled milled rice, but parboiling of wholegrain rice did not enrich inorganic arsenic in the final milled product. Polished rice produced from the parboiling of both rough and wholegrain rice significantly reduced cadmium compared to nonparboiled polished rice, by 25%. This study also identified that trimethylarsine oxide and tretramethylarsonium are widely elevated in the husk and bran of rice and, therefore, gives new insights into the biogeochemical cycling of arsenic in paddy ecosystems.

Elevated Trimethylarsine Oxide and Inorganic Arsenic in Northern Hemisphere Summer Monsoonal Wet Deposition.

For arsenic speciation, the inputs for wet deposition are not well understood. Here we demonstrate that trimethylarsine oxide (TMAO) and inorganic arsenic are the dominant species in monsoonal wet deposition in the summer Indian subcontinent, Bangladesh, with inorganic arsenic dominating, accounting for ∼80% of total arsenic in this medium. Lower concentrations of both species were found in monsoonal wet deposition in the winter Indian subcontinent, Sri Lanka. The only other species present was dimethylarsinic acid (DMAA), but this was usually below limits of detection (LoD). We hypothesize that TMAO and inorganic arsenic in monsoonal wet deposition are predominantly of marine origin. For TMAO, the potential source is the atmospheric oxidation of marine derived trimethylarsine. For inorganic arsenic, our evidence suggests entrainment of water column inorganic arsenic into atmospheric particulates. These conclusions are based on weather trajectory analysis and on the strong correlations with known wet deposition marine derived elements: boron, iodine, and selenium. The finding that TMAO and inorganic arsenic are widely present and elevated in monsoonal wet deposition identifies major knowledge gaps that need to be addressed regarding the understanding of arsenic's global cycle.

Assessing the genetic diversity of rice originating from Bangladesh, Assam and West Bengal.

BACKGROUND: Genetic diversity among rice cultivars from Bangladesh and North East India was assessed using a custom 384-SNP microarray assay. A total of 511 cultivars were obtained from several sources, choosing landraces likely to be from the aus subpopulation and modern improved cultivars from Bangladesh. Cultivars from the OryzaSNP set and Rice Diversity Panel 1 (RDP1) were also included for reference. RESULTS: The population analysis program STRUCTURE was used to infer putative population groups in the panel, revealing four groups: indica (76 cultivars), japonica (55) and two distinct groups within the aus subpopulation (aus-1 = 99, aus-2 = 151). Principal Component Analysis was used to confirm the four population groups identified by STRUCTURE. The analysis revealed cultivars that belonged to neither aus-1 nor aus-2 but which are clearly aus based on the combined probabilities of their membership of the two aus groups which have been termed aus-admix (96). Information obtained from the panel of 511 cultivars was used to assign rice groups to 74 additional landraces obtained from Assam and West Bengal. While both the aus-1 and aus-2 groups were represented approximately equally in India, aus-2 (which includes cultivar N 22) was more common in Bangladesh, but was not found at all in West Bengal. CONCLUSIONS: Examining the distribution of landrace names within theaus-1 and aus-2 groups suggests that aus-1 is associated with the term "boro", a word used to describe a winter growing season in Bangladesh and Assam. The information described here has been used to select a population of 300 cultivars for Genome Wide Association studies of the aus rice subpopulation.

Lead in rice: analysis of baseline lead levels in market and field collected rice grains.

In a large scale survey of rice grains from markets (13 countries) and fields (6 countries), a total of 1578 rice grain samples were analysed for lead. From the market collected samples, only 0.6% of the samples exceeded the Chinese and EU limit of 0.2 µg g(-1) lead in rice (when excluding samples collected from known contaminated/mine impacted regions). When evaluating the rice grain samples against the Food and Drug Administration's (FDA) provisional total tolerable intake (PTTI) values for children and pregnant women, it was found that only people consuming large quantities of rice were at risk of exceeding the PTTI from rice alone. Furthermore, 6 field experiments were conducted to evaluate the proportion of the variation in lead concentration in rice grains due to genetics. A total of 4 of the 6 field experiments had significant differences between genotypes, but when the genotypes common across all six field sites were assessed, only 4% of the variation was explained by genotype, with 9.5% and 11% of the variation explained by the environment and genotype by environment interaction respectively. Further work is needed to identify the sources of lead contamination in rice, with detailed information obtained on the locations and environments where the rice is sampled, so that specific risk assessments can be performed.

Genome wide association mapping of grain arsenic, copper, molybdenum and zinc in rice (Oryza sativa L.) grown at four international field sites.

The mineral concentrations in cereals are important for human health, especially for individuals who consume a cereal subsistence diet. A number of elements, such as zinc, are required within the diet, while some elements are toxic to humans, for example arsenic. In this study we carry out genome-wide association (GWA) mapping of grain concentrations of arsenic, copper, molybdenum and zinc in brown rice using an established rice diversity panel of ∼ 300 accessions and 36.9 k single nucleotide polymorphisms (SNPs). The study was performed across five environments: one field site in Bangladesh, one in China and two in the US, with one of the US sites repeated over two years. GWA mapping on the whole dataset and on separate subpopulations of rice revealed a large number of loci significantly associated with variation in grain arsenic, copper, molybdenum and zinc. Seventeen of these loci were detected in data obtained from grain cultivated in more than one field location, and six co-localise with previously identified quantitative trait loci. Additionally, a number of candidate genes for the uptake or transport of these elements were located near significantly associated SNPs (within 200 kb, the estimated global linkage disequilibrium previously employed in this rice panel). This analysis highlights a number of genomic regions and candidate genes for further analysis as well as the challenges faced when mapping environmentally-variable traits in a highly genetically structured diversity panel.

A simple preparation of a stable CdS-polyacrylamide nanocomposite: structure, thermal and optical properties.

A facile approach was employed for the preparation of stable luminescent nanocomposites of CdS quantum dots (QDs) and polyacrylamide (PAM) through the cross coupling chemistry. Initially, CdS QDs were synthesized in a well controlled manner using 3-mercaptopropionic acid as a capping agent. Then, carboxylic acid groups on CdS QDs were chemically incorporated into PAM matrices with the assistance of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride and N-hydroxysulfosuccinimide coupling agents. FT-IR analysis was used to investigate the chemical incorporation of CdS QDs in PAM matrices via the covalent protocol. The XPS elemental mapping studies further suggested the formation of CdS-PAM nanocomposites. FE-SEM and TEM images were engaged to study the morphologies, and distribution of CdS QDs in the PAM networks. The physical structure of the CdS-PAM nanocomposites was investigated by XRD analysis. Thermal stability of the nanocomposites was observed to be enhanced in compare to PAM as evidenced from TGA data. The UV-vis and photoluminescence studies of the CdS-PAM nanocomposites suggested their promising optical applications.

Variation in rice cadmium related to human exposure.

Cereal grains are the dominant source of cadmium in the human diet, with rice being to the fore. Here we explore the effect of geographic, genetic, and processing (milling) factors on rice grain cadmium and rice consumption rates that lead to dietary variance in cadmium intake. From a survey of 12 countries on four continents, cadmium levels in rice grain were the highest in Bangladesh and Sri Lanka, with both these countries also having high per capita rice intakes. For Bangladesh and Sri Lanka, there was high weekly intake of cadmium from rice, leading to intakes deemed unsafe by international and national regulators. While genetic variance, and to a lesser extent milling, provide strategies for reducing cadmium in rice, caution has to be used, as there is environmental regulation as well as genetic regulation of cadmium accumulation within rice grains. For countries that import rice, grain cadmium can be controlled by where that rice is sourced, but for countries with subsistence rice economies that have high levels of cadmium in rice grain, agronomic and breeding strategies are required to lower grain cadmium.

Immobilization of proteins onto poly(2-hydroxyethyl methacrylate) functionalized Fe-Au/core-shell nanoparticles via adsorption strategy.

Biocompatible magnetic nanocomposites of Fe-AuNPs and poly(2-hydroxylethyl methacrylate) (PHEMA) were employed as a strategic protein immobilization platform. The hybrid magnetic nanocomposites were prepared by applying a 'grafting to' ATRP protocol. Fe-AuNPs having Fe core and Au shell were initially prepared by the inverse micelle method. Disulfide-containing PHEMA (DT-PHEMA) was grafted to the Fe-AuNPs surface by taking the advantages of the thiol chemistry. The grafting of DT-PHEMA to the Fe-AuNPs was confirmed by relevant spectroscopic analyses. The superparamagnetic property, a basic requirement for facile protein immobilization, of the magnetic nanocomposites was measured by the SQUID analysis. Lysozyme, gamma-globulins and bovine serum albumin (BSA) were immobilized onto magnetic nanocomposites via the adsorption strategy. The absorption intensity of lysozyme, gamma-globulins and BSA on the PHEMA grafted Fe-AuNPs were observed to be higher than that of bare Fe-AuNPs.

A facile route towards the synthesis of polystyrene/zinc oxide nanocomposites.

ZnO nanoparticles were covalently wrapped by polystyrene (PS) through surface thiol-lactam initiated radical polymerization using the grafting from approach. The surface of ZnO nanoparticles was initially modified by 3-mercapto propyltrimethoxysilane to afford thiol functionalized ZnO nanoparticles (ZnO-SH). The controlled radical polymerization of styrene (St) was subsequently accomplished by using an initiating system of ZnO-SH and butyrolactam. FT-IR, XPS, XRD, TGA, DSC, TEM and DLS were employed to investigate the chemical structure, morphology, thermal properties, the size and size distribution of nanocomposites. The dispersibility of ZnO nanoparticles was observed to be significantly improved upon functionalization by PS brushes. The controlled nature of the surface initiated thiol-lactam aided polymerization of St from the ZnO nanoparticles surface was confirmed by GPC analysis.

Synthesis and characterization of TiO2/poly(methyl methacrylate) nanocomposites via surface thiol-lactam initiated radical polymerization.

An approach to the surface modification of TiO2 nanoparticles was described based on the thiol functionalization of TiO2 followed by thiol-lactam initiated radical polymerization (TLIRP) of methyl methacrylate (MMA). FT-IR, XRD and XPS analyses confirmed the grafting of the polymer on the TiO2 surface. TGA analysis revealed superior thermal stability of PMMA-g-TiO2 compared with PMMA. TEM measurements and time-dependent phase monitoring suggested much higher colloidal stability of PMMA-g-TiO2 than TiO2 in toluene. The controlled nature of the TLIRP of MMA from the surface of TiO2 was determined by GPC analysis.