Ligand cross-feeding resolves bacterial vitamin B12 auxotrophies.

Cobalamin (vitamin B12, herein referred to as B12) is an essential cofactor for most marine prokaryotes and eukaryotes1,2. Synthesized by a limited number of prokaryotes, its scarcity affects microbial interactions and community dynamics2-4. Here we show that two bacterial B12 auxotrophs can salvage different B12 building blocks and cooperate to synthesize B12. A Colwellia sp. synthesizes and releases the activated lower ligand α-ribazole, which is used by another B12 auxotroph, a Roseovarius sp., to produce the corrin ring and synthesize B12. Release of B12 by Roseovarius sp. happens only in co-culture with Colwellia sp. and only coincidently with the induction of a prophage encoded in Roseovarius sp. Subsequent growth of Colwellia sp. in these conditions may be due to the provision of B12 by lysed cells of Roseovarius sp. Further evidence is required to support a causative role for prophage induction in the release of B12. These complex microbial interactions of ligand cross-feeding and joint B12 biosynthesis seem to be widespread in marine pelagic ecosystems. In the western and northern tropical Atlantic Ocean, bacteria predicted to be capable of salvaging cobinamide and synthesizing only the activated lower ligand outnumber B12 producers. These findings add new players to our understanding of B12 supply to auxotrophic microorganisms in the ocean and possibly in other ecosystems.

Distinct glycoconjugate cell surface structures make the pelagic diatom Thalassiosira rotula an attractive habitat for bacteria.

Interactions between marine diatoms and bacteria have been studied for decades. However, the visualization of physical interactions between these diatoms and their colonizers is still limited. To enhance our understanding of these specific interactions, a new Thalassiosira rotula isolate from the North Sea (strain 8673) was characterized by scanning electron microscopy and confocal laser scanning microscopy (CLSM) after staining with fluorescently labeled lectins targeting specific glycoconjugates. To investigate defined interactions of this strain with bacteria the new strain was made axenic and co-cultivated with a natural bacterial community and in two- or three-partner consortia with different bacteria of the Roseobacter group, Gammaproteobacteria and Bacteroidetes. The CLSM analysis of the consortia identified six out of 78 different lectins as very suitable to characterize glycoconjugates of T. rotula. The resulting images show that fucose-containing threads were the dominant glycoconjugates secreted by the T. rotula cells but chitin and to a lesser extent other glycoconjugates were also identified. Bacteria attached predominantly to the fucose glycoconjugates. The colonizing bacteria showed various attachment patterns such as adhering to the diatom threads in aggregates only or attaching to both the surfaces and the threads of the diatom. Interestingly the colonization patterns of single bacteria differed strikingly from those of bacterial co-cultures, indicating that interactions between two bacterial species impacted the colonization of the diatom. Our observations help to better understand physical interactions and specific colonization patterns of distinct bacterial mono- and co-cultures with an abundant diatom of costal seas.

Robust Photoelectrochemical Route for the Ambient Fixation of Dinitrogen into Ammonia over a Nanojunction Assembled from Ceria and an Iron Boride/Phosphide Cocatalyst.

The nitrogen reduction reaction is of great scientific significance as a hydrogen fuel carrier as well as a source of value-added products; in context to this, photoelectrochemical (PEC) nitrogen fixation emerges as an effective and environmentally benign strategy to meet the need. Hence, the current work reports an effective catalytic system containing a low-cost iron boride-based cocatalyst onto the CeO2 nanosheet matrix for photoelectrochemical nitrogen reduction reaction. The harmonized electronic property and the ensemble effect of phosphorus and boron in FeB/P with unsaturated metal sites make it a site-selective cocatalyst for nitrogen adsorption and its polarization. Furthermore, the low Fermi level of iron borophosphide enhances the trapping of photogenerated electrons from CeO2 and productively provides it to the adsorbed nitrogen species. The observed peculiar photocurrent behavior confirms the interaction of photogenerated electrons with adsorbed nitrogen species and its subsequent reduction by the surrounding protonic environment. The optimized CeO2-FeB/P photoelectrocatalyst exhibited an excellent NH3 yield velocity, i.e., 9.54 µg/h/cm2 at -0.12 V vs RHE with a solar-to-chemical conversion efficiency of 0.046% under ambient conditions. The same catalyst is also very active under near-zero biasing conditions and possesses impressive durability even after multiple uses. This work might strategically direct a promising way for the exploration of new photoelectrocatalytic systems for effective PEC-nitrogen reduction reaction.

Cardiac Registries During the COVID-19 Pandemic: Lessons Learned.

PURPOSE OF THIS REVIEW: We discuss the role of observational studies and cardiac registries during the COVID-19 pandemic. We focus on published cardiac registries and highlight contributions to the field that have had clinical implications. RECENT FINDINGS: We included observational studies of COVID-19 patients published in peer-reviewed medical journals with defined inclusion and exclusion criteria, defined study design, and primary outcomes. A PubMed and MEDLINE literature review results in 437 articles, of which 52 include patients with COVID-19 with cardiac endpoints. From July 2020 to December 2021, the average time from last data collected to publication was 8.9 ± 4.1 months, with an increasing trend over time (R = 0.9444, p < 0.0001). Of the 52 articles that met our inclusion criteria, we summarize main findings of 4 manuscripts on stroke, 14 on acute coronary syndrome, 4 on cardiac arrest, 7 on heart failure, 7 on venous thromboembolism, 5 on dysrhythmia, and 11 on different populations at risk for cardiovascular. Registries are cost effective, not disruptive to essential health services, and can be rapidly disseminated with short intervals between last data point collected and publication. In less than 2 years, cardiac registries have filled important gaps in knowledge and informed the care of COVID-19 patients with cardiovascular conditions.

Role of home visits by volunteer community health workers: to improve the coverage of micronutrient powders in rural Bangladesh.

OBJECTIVE: We assessed the role of home visits by Shasthya Shebika (SS) - female volunteer community health workers (CHWs) - in improving the distribution of micronutrient powder (MNP), and explored the independent effects of caregiver-provider interaction on coverage variables. DESIGN: We used data from three cross-sectional surveys undertaken at baseline (n 1927), midline (n 1924) and endline (n 1540) as part of an evaluation of a home fortification programme. We defined an exposure group as one that had at least one SS visit to the caregiver's household in the 12 months preceding the survey considering three outcome variables - message (ever heard), contact (ever used) and effective coverage (regular used) of MNP. We performed multiple logistic regressions to explore the determinants of coverage, employed an 'interaction term' and calculated an odds ratio (OR) to assess the modifying effect of SS's home visits on coverage. SETTINGS: Sixty-eight sub-districts from ten districts of Bangladesh. PARTICIPANTS: Children aged 6-59 months and their caregivers. RESULTS: A home visit from an SS positively impacts message coverage at both midline (ratio of OR 1·70; 95 % CI 1·25, 2·32; P < 0·01) and endline (ratio of OR 3·58; 95 % CI 2·22, 5·78; P < 0·001), and contact coverage both at midline (ratio of OR 1·48; 95 % CI 1·06, 2·07; P = 0·021) and endline (ratio of OR 1·74; 95 % CI 1·23, 2·47; P = 0·002). There was no significant effect of a SS's home visit on effective coverage. CONCLUSIONS: The households visited by BRAC's volunteer CHWs have better message and contact coverage among the children aged 6-59 months.

Understanding drivers of private-sector compliance to large-scale food fortification: A case study on edible oil value chains in Bangladesh.

Micronutrient deficiency is a pertinent global challenge that affects billions of people and has deleterious health effects. Large-scale food fortification (LSFF) is a cost- effective way to tackle micronutrient deficiency and improve health outcomes, particularly in low- and middle-income countries (LMICs). However, the success of LSFF in LMICs is often hampered by limited compliance with fortification mandates by the private sector, who supply fortified foods. In this paper, we use a case study of the edible oil produced in Bangladesh to analyze the factors facilitating and impeding this compliance by for-profit actors. We identified four bottlenecks that disincentivize private sector actors' decision to comply. First, fortified and non-fortified products co-exist in the market, disincentivizing producers to invest in fortification. Second, the lack of traceability reduces the risk for large-scale producers' non-compliance with the regulation. Third, small-scale producers face economic pressures that prevent them from adequately fortifying oil products. Lastly, law enforcement is currently inconsistent, allowing the supply of under-fortified oil in the market. Given the evidence, we recommend to strengthen the control of bulk item fortification through more frequent and rigorous surveillance at the production level. This will ensure that resource constrained consumers who also have the greatest potential to benefit from added nutrients, remain able to access affordable and nutrient-enriched food.

Efficient Photon Conversion via Double Charge Dynamics CeO2-BiFeO3 p-n Heterojunction Photocatalyst Promising toward N2 Fixation and Phenol-Cr(VI) Detoxification.

For better exciton separation and high catalytic activity, the most trailblazing stratagem is to construct defect engineered low-dimensional p-n heterojunction framed photocatalytic systems. In this context, we have developed a rod-sheet (1D-2D) p-n heterojunction of MCeO2-BiFeO3 by a simple hydrothermal method and scrutinized its photocatalytic performance toward N2 fixation and phenol/Cr(VI) detoxification. The intimate contact between MCeO2 and BiFeO3 in the junction material is well established via X-ray diffraction (XRD), UV-vis diffuse reflectance spectrosopy (DRS), transmission electron microscopy (TEM), and photoelectrochemical studies. Further, scanning electron microscopy (SEM) and TEM pictures clearly support the decoration of MCeO2 nanorods over BiFeO3 sheets and also depict the junction boundary. Additionally, photoluminescence (PL), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), and Raman measurements give solid evidence toward the presence of an oxygen vacancy. Moreover, the Mott-Schottky result indicates a feasible band edge potential favoring the p-n heterojunction with a built-in electric field between BiFeO3 and MCeO2 favoring a double charge dynamic. The MCeO2-BFO p-n junction displays a notable catalytic activity, i.e., 98.2% Cr(VI) reduction and 85% phenol photo-oxidation, and produces 117.77 µmol h-1 g-1 of ammonia under light irradiation. Electrochemical analysis suggests a four-electron/five proton-coupled N2 photoreduction pathway. The designed oxygen vacancy oriented p-n heterojunction suffering double charge migration shows significant catalytic performance due to effective electron-hole separation as justified via PL, electrochemical impedance spectra (EIS), and Bode phase analysis.

Impact of urbanisation on urban heat island intensity during summer and winter over Indian metropolitan cities.

Industrial and economic development along with the rapid growth in urban population over the global cities is generating a warmer inner core in comparison to the surrounding natural landscape, the common feature of the phenomena of urban heat island (UHI). In the earlier part of the study, the spatial relationship of the changes in the land cover types and land surface temperature (LST) is analysed for metropolitan cities of India during winter season using remote sensing techniques. In the present study, an attempt has been made to estimate the UHI intensities over the metropolitan cities of India during summer season. The LST estimated using the Landsat 7 ETM+ images reveals the presence of a unique form of surface UHIs in the dense built-up areas of different cities. The intensities of UHIs over these cities during summer season are noticed to be in the range of 10.5-14 °C. Delhi possesses the highest UHI intensity in the range of 13.4-14.0 °C, and Kolkata possessed the lowest UHI intensity in the range of 10.5-11.7 °C. Higher-temperature zones (hotspots) are noticed to be increasing within the built-up areas and barren lands. The temperature of hotspots for the northern cities Delhi and Jaipur is observed to be in the range of 45-50 °C and is highest among the cities under consideration. On comparison with the winter results, the LST ranges, UHI intensities and the hotspot ranges for summer season are found be noticeably higher. The LST distribution and the UHI pattern of these cities are found to different during summer season in comparison to the winter season.

One-Pot-Architectured Au-Nanodot-Promoted MoS2/ZnIn2S4: A Novel p-n Heterojunction Photocatalyst for Enhanced Hydrogen Production and Phenol Degradation.

Developing effective and simple one-pot synthetic strategies regarding the formation of heterojunction photocatalytic semiconductors remains an intense challenge in research pursuits. Further scheming of the p-n heterojunction has sustained renewed interest in catalysis, photocatalysis, energy storage, and conversion because they easily accelerate the bulk charge separation efficiency. Thus we have successfully designed a Au-MoS2/ZnIn2S4 heterojunction photocatalyst for the first time by adopting a simple one-pot hydrothermal technique, followed by a deposition-precipitation method. By adjusting the mole ratio of Mo with that of Zn and In precursors, we have fabricated a MoS2/ZnIn2S4 p-n heterojunction photocatalyst, and the established p-n heterojunction between MoS2 and ZnIn2S4 is demonstrated by various physicochemical and morphological characterizations. An interfacial junction is created between MoS2 and ZnIn2S4 at the depletion region via an in situ formation mechanism, leading to the enhancement of the charge separation through the p-n heterojunction and thus improving the photocatalytic activity. Moreover, the photocatalytic activity is projected to further improve by the incorporation of Au nanodots on the surface of MoS2/ZnIn2S4 photocatalysts. The increase in activity is due to the generation and participation of a large number of direct-electron-transfer-induced hot electrons in the photochemical reaction. From the experimental results, Au-MoS2/ZnIn2S4 heterojunction photocatalysts with only 1% MoS2 and 1% Au loading content displayed a 561.25 µmol/h H2 evolution rate and 84% degradation of phenol, which are nearly 15 and 6 times higher than those neat ZnIn2S4. In addition Au-MoS2/ZnIn2S4 photocatalysts exhibit a photocurrent density of ∼2.56 mAcm-2, which is nearly 2.4 times higher than that of the MoS2/ZnIn2S4 heterojunction photocatalyst. This exertion represents the synergetic enhancement of photocatalytic activity through the p-n heterojunction as well as the hot-electron participation by the metal nanocatalyst, which is an inspiration for developing efficient photocatalysts.

Using a gender lens to understand eating behaviours of adolescent females living in low-income households in Bangladesh.

Adolescence is a critical period characterized by rapid physical, psychological, and social development and growth. In Bangladesh, high rates of undernutrition persist among adolescent females living in low-income households. Prevalence of adolescent marriage and pregnancy is extremely high, with almost half of Bangladeshi women giving birth by 18 years of age. Qualitative research was carried out from April to June 2017 to examine individual, social, and environmental factors influencing eating behaviours of female adolescents between 15 and 19 years of age living in low-income families in urban and rural settings in Bangladesh. Methods included freelisting exercises (33), key informant interviews (11), in-depth interviews (24), direct observations (16), and focus group discussions (12). Findings show that household food insecurity necessitates adjustments in meal food quality and frequency. Gender norms prescribe that females receive small meal portions and make sacrifices in food consumption so that male family members can eat more. Work and school schedules cause long breaks between meal consumption, restricting food intake of adolescent females for extended periods. Gender discrimination and its manifestations likely amplify susceptibility to psychological stresses in adolescent females. An inferior social position makes adolescent females living in food insecure households vulnerable to undernutrition, with factors affecting food deprivation increasing as they approach childbearing. Policies to increase age of marriage and reduce adolescent pregnancy must continue. Programmes must ensure that school-going adolescents eat adequately during the school day. Prolonging school education and strengthening the economic viability of women should alter cultural expectations regarding marriage age and normative female roles.

Architecture of Biperovskite-Based LaCrO3/PbTiO3 p-n Heterojunction with a Strong Interface for Enhanced Charge Anti-recombination Process and Visible Light-Induced Photocatalytic Reactions.

Erection of a resourceful p-n heterojunction is a state-of-the-art tactic to flourish the charge anti-recombination process at the heterojunction interface and boost the photocatalytic activities under visible light irradiation. In the present work, we have engineered a new series of PbTiO3/LaCrO3 (PT/LC) p-n heterojunction through a facile two-step combustion process. The structural, interface, and optical analysis distinctly revealed a strong intact between p-type LaCrO3 and n-type PbTiO3, elucidating their electronic channelization and substantial reduction of electron-hole recombination at the PbTiO3/LaCrO3 interface, which extend the lifetime and population of photogenerated charges in the p-n heterojunction material. The asymmetry photocurrent in the opposite directions and an inverted characteristic V-shape Mott-Schottky plot of the optimal PT/LC (7/3) material demonstrated the construction of a p-n heterojunction. The optimal p-n heterojunction possesses excellent photostability, and it revealed the highest photocatalytic activity toward degradation of phenol, that is, 86% and hydrogen generation, that is, 343.57 µmol in 2 h. The enhanced photocatalytic activities of the p-n heterojunction materials in comparison to pristine ones are due to the higher separation charge carriers across the p-n heterojunction interface, which was deeply elucidated by carrying out electrochemical impedance spectroscopy, time-resolved photoluminescence spectroscopy, and photoluminescence analyses. These materials pave a new way to design the interface intact photocatalyst with an ultrafast approach for migration of photoexcited electrons across the p-n heterojunction and enhance the photocatalytic activities.

Fabrication of Hierarchical Two-Dimensional MoS2 Nanoflowers Decorated upon Cubic CaIn2S4 Microflowers: Facile Approach To Construct Novel Metal-Free p-n Heterojunction Semiconductors with Superior Charge Separation Efficiency.

Due to the enormous demand for effective conversion of solar energy and large-scale hydrogen production, cost-effective and long-lasting photocatalysts are believed to be necessary for global production of sustainable and clean hydrogen fuel. Robust and highly efficient p-n heterojunction photocatalysts have a striking ability to enhance light-harvesting capacity and retard the recombination of photoexcitons. A series of p-MoS2/n-CaIn2S4 heterojunction composites with different MoS2 contents have been synthesized via a facile two-step hydrothermal technique in which rose-like p-MoS2 nanoflowers are decorated upon n-type cubic CIS microflowers. In the synthesis protocol highly dispersed MoS2 nanoflowers provided more active edge sites for the growth of c-CIS nuclei, leading to a hierarchical architecture with intimate interfacial contact. The formation of a hierarchical flower-like morphology of the photocatalyst has been established by an HRTEM and FESEM study. Electrochemical characterization, especially the slope of the curve from Mott-Schottky analysis and nature of the current from LSV, reveals the p-n heterojunction nature of the composite photocatalyst. The fabricated heterojunction photocatalysts were further examined for visible light photocatalytic H2 evolution. Far exceeding those for the neat c-CIS and MoS2, it is seen that the p-MoS2/n-CIS heterojunction photocatalyst with an optimum content of MoS2 exhibited enhanced H2 evolution using a 0.025 M Na2S/Na2SO3 solution as hole quenching agent under visible light illumination. The 0.5 wt % p-MoS2/n-CIS photocatalyst presents a higher H2 production rate of 602.35 µmol h-1 with 0.743 mA cm-2 photocurrent density, 19 times and 8 times higher than those of neat c-CIS, respectively. This superior photocatalyic activity is due to the efficient separation of electron-hole charge carriers at the interface, as supported by a photoluminescence study and EIS measurements.

Factors associated with child hunger among food insecure households in Bangladesh.

BACKGROUND: Hunger is associated with food insecurity at the household level and is considered as a global public health problem with long term adverse consequences on children's health. This study aims to determine the factors associated with child hunger from a nationally representative sample in Bangladesh among food insecure households. METHODS: Data was derived from the Food Security and Nutritional Surveillance Project; 14,712 children aged 6-59 months belonging to food insecure households contributed to the analysis. Information on food security at the household level was collected for 30 days preceding the survey. Descriptive statistics served to illustrate the variables studied and multiple logistic regression analysis was conducted to identify the significant risk factors for child hunger. RESULTS: Overall 10% of the children were found to be hungry. After adjusting for seasonality, residence type and education level of household head, the variables - female headed households [OR: 1.87 (1.43-2.45); p < 0.001], severely food insecure households [OR: 10.5 (1.43-76.6); p < 0.05], households having women with no education [OR: 1.56 (1.27-1.92); p < 0.05], poorest asset quintile [OR: 1.50 (1.11-2.15); p < 0.05] and the amount of rice consumed per household per week [OR: 0.94 (0.92-0.96); p < 0.001] were found to be significantly and independently associated with child hunger. CONCLUSIONS: Out of the potential risk factors examined, our study found significant and independent association of five variables with child hunger: sex of the household head, household food insecurity status, educational status of household women and asset index. Despite all sampled household being food insecure, degree of household food insecurity status appeared to be the strongest predictor of child hunger.

Determinants of age-specific undernutrition in children aged less than 2 years-the Bangladesh context.

Globally, undernutrition affects nearly half of all children aged less than 5 years. It is more prominent in low- and middle-income countries. This study aimed to identify the age-specific risk factors for different categories of undernutrition among Bangladeshi children aged less than 2 years. Data of 10,291 children aged less than 2 years were collected between October 2011 to November 2013 through the Food Security Nutritional Surveillance Project in Bangladesh. Simple logistic regression established bivariate relationships between the categories of undernutrition and the relevant risk factors. Multiple logistic regression constructed the age-specific regression models depicting the independent association and effect size of the risk factors contributing to the various categories of undernutrition among study population. Stunting was prevalent among 30.9% of the study children, whereas 9.7% were wasted and 24.9% were underweight. Being a male child, increase in age, maternal body mass index and education, and household food insecurity were the strongest predictors for all categories of undernutrition in terms of effect size. Our study shows that the different categories of childhood undernutrition have different age-specific risk factors. Maternal body mass index and household food insecurity were the common age-specific risk factors for all categories of undernutrition. We expect our findings to enhance the existing evidence base for the risk factors of undernutrition among children aged less than 2 years.

First-Principles Investigations of Novel Guanidine-Based Dyes.

In the pursuit of finding efficient D-π-A organic dyes as photosensitizers for dye-sensitized solar cells (DSSCs), first-principles calculations of guanidine-based dyes [A1-A18] were executed using density functional theory (DFT). The various electronic and optical properties of guanidine-based organic dyes with different D-π-A structural modifications were investigated. The structural modification of guanidine-based dyes largely affects the properties of molecules, such as excitation energies, the oscillator strength dipole moment, the transition dipole moment, and light-harvesting efficiencies. The energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is responsible for the reduction and injection of electrons. Modification of the guanidine subunit by different structural modifications gave a range of HOMO-LUMO energy gaps. Chemical and optical characteristics of the dyes indicated prominent charge transfer and light-harvesting efficiencies. The wide electronic absorption spectra of these guanidine-based dyes computed by TD-DFT-B3LYP with 6-31G, 6-311G, and cc-PVDZ basis sets have been observed in the visible region of spectra due to the presence of chromophore groups of dye molecules. Better anchorage of dyes to the surface of TiO2 semiconductors helps in charge-transfer phenomena, and the results suggested that -COOH, -CN, and -NO2 proved to be proficient anchoring groups, making dyes very encouraging candidates for DSSCs. Molecular electrostatic potential explained the electrostatic potential of organic dyes, and IR spectrum and conformational analyses ensured the suitability of organic dyes for the fabrication of DSSCs.

Effects of healthcare spending on public health status: An empirical investigation from Bangladesh.

The escalation of healthcare spending in many nations, particularly in emerging countries such as Bangladesh, may be largely attributed to the growing demand for healthcare services. Evidently, there has been a significant expansion in the public funding allocated to the health sector in Bangladesh, intending to enhance health outcomes. Therefore, the purpose of this study was to examine the impact of healthcare expenditure on health outcomes, specifically focusing on the reduction in different mortality rates and the transmission of various infectious diseases. A total of 30 years of data (1990-2019) on the health sector of Bangladesh were collected from different national and international sources. The Vector Autoregression with Exogenous Variables (VARX) model was employed to determine the effects of healthcare expenditure on health outcomes. Results revealed that the per capita health expenditure and the number of doctors showed a significant positive impact on life expectancy and maternal and child health. Also, the government's annual budget on the health sector and number of doctors had a significant positive impact on lowering deaths by Diphtheria, Cholera, Tuberculosis, and Malaria diseases. In order to develop a sustainable healthcare system within the nation, it is imperative for the government to prioritize the allocation of sufficient and effective healthcare funding to cater to the needs of the populace.

Fabrication of nano filler doped PVA/starch biodegradable composites with enhanced thermal conduction, water barrier and antimicrobial performance for food industry.

In this work there was investigated the synergistic effect of the nanomaterials-the Montmorillonite (MMT) and the vanadium pentoxide (V2O5) on the polyvinyl alcohol (PVA)/starch composite. The composite films were prepared by the solvent casting method. The characterization of the composites showed that the addition of the MMT and the V2O5 to PVA/starch composite decreased the water solubility and water absorption capacity of the film. Both of the reinforcement materials enriched values of thermal conductivity and thermal stability of the composite. The TG/DTA and universal testing machine (UTM) analysis exhibited that MMT and V2O5 augmented the thermal robustness and tensile strength of composites and decreased the strain to break. It was also observed that greater MMT concentration accelerates mechanical strength deterioration of the film owing to agglomeration. The scanning electron microscopy (SEM) analysis reflected great change in the surface morphology of the films in the presence and absence of MMT and V2O5. This was due to the interaction amid constituents of the composite. The chemical interaction between the PVA, Starch, MMT and the V2O5 was also established via Fourier-transform infrared spectroscopy (FTIR) analysis, which revealed fluctuations in the absorbance position and intensity of the PVA/Starch. Antimicrobial activities against seven different cultures of bacteria (both-gram positive and -negative) and one fungus (Candida albicans), exposed that antimicrobial performance of the PVA amplified upon addition of the starch, MMT and V2O5, making these composites prospective candidates for the biodegradable packaging materials.

Vitamin B12 is not shared by all marine prototrophic bacteria with their environment.

Vitamin B12 (cobalamin, herein B12) is an essential cofactor involved in amino acid synthesis and carbon resupply to the TCA cycle for most prokaryotes, eukaryotic microorganisms, and animals. Despite being required by most, B12 is produced by only a minor fraction of prokaryotes and therefore leads to complex interaction between prototrophs and auxotrophs. However, it is unknown how B12 is provided by prototrophs to auxotrophs. In this study, 33 B12 prototrophic alphaproteobacterial strains were grown in co-culture with Thalassiosira pseudonana, a B12 auxotrophic diatom, to determine the bacterial ability to support the growth of the diatom by sharing B12. Among these strains, 18 were identified to share B12 with the diatom, while nine were identified to retain B12 and not support growth of the diatom. The other bacteria either shared B12 with the diatom only with the addition of substrate or inhibited the growth of the diatom. Extracellular B12 measurements of B12-provider and B12-retainer strains confirmed that the cofactor could only be detected in the environment of the tested B12-provider strains. Intracellular B12 was measured by LC-MS and showed that the concentrations of the different B12-provider as well as B12-retainer strains differed substantially. Although B12 is essential for the vast majority of microorganisms, mechanisms that export this essential cofactor are still unknown. Our results suggest that a large proportion of bacteria that can synthesise B12 de novo cannot share the cofactor with their environment.

Impact of market-based home fortification with micronutrient powder on childhood anemia in Bangladesh: a modified stepped wedge design.

Background: Anemia poses a significant public health problem, affecting 1.6 billion people and contributing to the loss of 68.4 million disability-adjusted life years. We assessed the impact of a market-based home fortification program with micronutrient powder (MNP) called Pushtikona-5 implemented by Bangladesh Rural Advancement Committee (BRAC) on the prevalence of anemia among children aged 6-59 months in Bangladesh. Methods: We used a modified stepped wedged design and conducted three baseline, two midline, and three endline surveys to evaluate the Pushtikona-5 program implemented through three BRAC program platforms. We interviewed children's caregivers, and collected finger-prick blood samples from children to measure hemoglobin concentration. We also collected data on coverage of Pushtikona-5 and infant and young child feeding (IYCF) practices. We performed bivariate and multivariable analysis and calculated adjusted risk ratios (ARRs) to assess the effect of program outcomes. Results: A total of 16,936 households were surveyed. The prevalence of anemia was 46.6% at baseline, dropping to 32.1% at midline and 31.2% at endline. These represented adjusted relative reductions of 34% at midline (RR 0.66, 95%CI 0.62 to 0.71, value of p <0.001) and 32% at endline (RR 0.68, 95%CI 0.64 to 0.71, value of p <0.001) relative to baseline. Regarding MNP coverage, at baseline, 43.5% of caregivers surveyed had heard about MNP; 24.3% of children had ever consumed food with MNP, and only 1.8% had consumed three or more sachets in the 7 days preceding the survey. These increased to 63.0, 36.9, and 4.6%, respectively, at midline and 90.6, 68.9, and 11.5%, respectively, at endline. Conclusion: These results show evidence of a reduction in the prevalence of anemia and an improvement in coverage. This study provides important evidence of the feasibility and potential for impact of linking market-based MNP distribution with IYCF promotion through community level health workers.