1,400 research outputs found

    Torsional Vibrations of Finite Hollow Poroelastic Circular Cylinders

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    In this paper, the problem of torsional vibrations of a homogeneous, isotropic poroelastic hollow cylinder of finite length is solved. Results of solid cylinder of finite length and classical theory of elasticity are obtained as a particular case. Frequency is calculated numerically for different materials and presented in tables

    Multienzyme Immobilized Polymeric Membrane Reactor for the Transformation of a Lignin Model Compound

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    We have developed an integrated, multienzyme functionalized membrane reactor for bioconversion of a lignin model compound involving enzymatic catalysis. The membrane bioreactors were fabricated through the layer-by-layer assembly approach to immobilize three different enzymes (glucose oxidase, peroxidase and laccase) into pH-responsive membranes. This novel membrane reactor couples the in situ generation of hydrogen peroxide (by glucose oxidase) to oxidative conversion of a lignin model compound, guaiacylglycerol-β-guaiacyl ether (GGE). Preliminary investigation of the efficacy of these functional membranes towards GGE degradation is demonstrated under convective flow mode. Over 90% of the initial feed could be degraded with the multienzyme immobilized membranes at a residence time of approximately 22 s. GGE conversion product analysis revealed the formation of oligomeric oxidation products upon reaction with peroxidase, which may be a potential hazard to membrane bioreactors. These oxidation products could further be degraded by laccase enzymes in the multienzymatic membranes, explaining the potential of multi enzyme membrane reactors. The multienzyme incorporated membrane reactors were active for more than 30 days of storage time at 4 °C. During this time span, repetitive use of the membrane reactor was demonstrated involving 5–6 h of operation time for each cycle. The membrane reactor displayed encouraging performance, losing only 12% of its initial activity after multiple cycles of operation

    Treatment-seeking and recovery among young undernourished children post-hospital discharge in Bangladesh: a qualitative study

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    Introduction: Post-hospital discharge mortality is high among undernourished children in many low and middle-income countries. Although a number of quantitative studies have highlighted a range of potential socio-cultural, economic and health system factors influencing paediatric post-discharge treatment-seeking and recovery, few studies have explored family and provider perspectives of the post-discharge period in-depth. Methods: This work was part of a large, multi-country prospective cohort study, the Childhood Acute Illness and Nutrition (CHAIN) Network. We conducted a qualitative sub-study to understand the post-discharge treatment-seeking and recovery experiences of families of undernourished children aged 2–23 months admitted in a rural and urban icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh) hospital. Methods included repeat in-depth interviews (73 interviews in total) with 29 family members of 17 purposively selected children. These data were supplemented by interviews with 33 health workers, and by observations in hospitals and homes. Results: Important drivers of treatment-seeking perceived to support recovery included advice provided to family members while in hospital, media campaigns on hygiene practice, availability of free treatment, and social and financial support from family members, relatives and neighbours. Key perceived challenges included low household incomes, mothers having to juggle multiple responsibilities in addition to caring for the sick child, lack of support (sometimes violence) from the child’s father, and family members’ preference for relatively accessible drug shops, physicians or healers over hospital admission. Conclusion: Development of interventions that address the challenges that families face is essential to support post-discharge adherence to medical advice and recovery. Potential interventions include strengthening information giving during hospitalization on what post-discharge care is needed and why, reducing direct and indirect costs associated with hospital visits, engaging fathers and other ‘significant others’ in post-discharge advice, and building mobile phone-based support for follow-up care

    Unintended consequences of programmatic changes to infant and young child feeding practices in Bangladesh

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    BRAC, an international development organization, implemented a home‐fortification programme from 2014 to 2018 in Bangladesh. This study aimed to understand the unintended consequences of programmatic changes that occurred during the implementation of the programme on the prevalence of good infant and young child feeding (IYCF) practices and other associated factors. We used pooled data from eight cross‐sectional surveys and data from a series of qualitative investigations carried out as part of a mixed‐methods evaluation approach. A total of 6,479 caregivers of children aged 6 to 23 months participated in the surveys. The prevalence of good IYCF practices increased from baseline (42.1%) to midline (45.3%), but it decreased at the endline survey (31.9%). Qualitative investigations identified several reasons for low IYCF practices at the programme level, such as the withdrawal of community health worker (CHW) incentives for promoting IYCF, providing incentives for the home‐fortification of micronutrient powder (MNP) and changing the focus from IYCF promotion to MNP promotion. A multivariable generalized estimating equation model for pooled data revealed that caregivers were 28% (adjusted risk ratio [ARR]: 0.72, 95% CI [0.67, 0.78]) less likely to maintain good IYCF practices during the period when CHWs were not incentivized to promote IYCF compared to the period when CHWs were incentivized to promote it. The prevalence of good IYCF practices decreased from both baseline and midline to the endline survey due to the unintended consequences of the programmatic changes. An integrated intervention strategy to promote the home‐fortification of MNP and IYCF could be helpful to avoid unintended negative consequences of programmatic changes.This research was funded by the Children's Investment Fund Foundation (CIFF; UK), grant number GR-01136

    Implementation of the World's largest measles-rubella mass vaccination campaign in Bangladesh: a process evaluation

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    Background: Gavi, the Vaccine Alliance, supported a mass vaccination Measles-Rubella Campaign (MRC) in Bangladesh during January–February 2014

    Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition

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    Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs

    The role of multiple marks in epigenetic silencing and the emergence of a stable bivalent chromatin state

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    We introduce and analyze a minimal model of epigenetic silencing in budding yeast, built upon known biomolecular interactions in the system. Doing so, we identify the epigenetic marks essential for the bistability of epigenetic states. The model explicitly incorporates two key chromatin marks, namely H4K16 acetylation and H3K79 methylation, and explores whether the presence of multiple marks lead to a qualitatively different systems behavior. We find that having both modifications is important for the robustness of epigenetic silencing. Besides the silenced and transcriptionally active fate of chromatin, our model leads to a novel state with bivalent (i.e., both active and silencing) marks under certain perturbations (knock-out mutations, inhibition or enhancement of enzymatic activity). The bivalent state appears under several perturbations and is shown to result in patchy silencing. We also show that the titration effect, owing to a limited supply of silencing proteins, can result in counter-intuitive responses. The design principles of the silencing system is systematically investigated and disparate experimental observations are assessed within a single theoretical framework. Specifically, we discuss the behavior of Sir protein recruitment, spreading and stability of silenced regions in commonly-studied mutants (e.g., sas2, dot1) illuminating the controversial role of Dot1 in the systems biology of yeast silencing.Comment: Supplementary Material, 14 page

    Assessing sustainment of health worker outcomes beyond program end: Evaluation results from an infant and young child feeding intervention in Bangladesh

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    Introduction: Alive and Thrive (A&T) implemented infant and young child feeding (IYCF) interventions in Bangladesh. We examine the sustained impacts on health workers' IYCF knowledge, service delivery, job satisfaction, and job readiness three years after the program's conclusion. Methods: We use data from a cluster-randomized controlled trial design, including repeated cross-sectional surveys with health workers in 2010 (baseline, n = 290), 2014 (endline, n = 511) and 2017 (post-endline, n = 600). Health workers in 10 sub-districts were trained and incentivized to deliver intensified IYCF counseling, and participated in social mobilization activities, while health workers in 10 comparison sub-districts delivered standard counseling activities. Accompanying mass media and policy change activities occurred at the national level. The primary outcome is quality of IYCF service delivery (number of IYCF messages reportedly communicated during counseling); intermediate outcomes are IYCF knowledge, job satisfaction, and job readiness. We also assess the role of hypothesized modifiers of program sustainment, i.e. activities of the program: comprehensiveness of refresher trainings and receipt of financial incentives. Multivariable difference-in-difference linear regression models, including worker characteristic covariates and adjusted for clustering at the survey sampling level, are used to compare differences between groups (intervention vs. comparison areas) and over time (baseline, endline, post-endline). Results: At endline, health workers in intervention areas discussed significantly more IYCF topics than those in comparison areas (4.9 vs. 4.0 topics, p < 0.001), but levels decreased and the post-endline gap was no longer significant (4.0 vs. 3.3 topics, p = 0.067). Comprehensive refresher trainings were protective against deterioration in service delivery. Between baseline and endline, the intervention increased health workers' knowledge (3.5-point increase in knowledge scores in intervention areas, vs. 1.5-point increase in comparison areas, p < 0.0001); and this improvement persisted to post-endline, suggesting a sustained program effect on knowledge. Job satisfaction and readiness both saw improvements among workers in intervention areas during the project period (baseline to endline) but regressed to a similar level as comparison areas by post-endline. Discussion: Our study showed sustained impact of IYCF interventions on health workers' knowledge, but not job satisfaction or job readiness—and, critically, no sustained program effect on service delivery. Programs of limited duration may seek to assess the status of and invest in protective factors identified in this study (e.g., refresher trainings) to encourage sustained impact of improved service delivery. Studies should also prioritize collecting post-endline data to empirically test and refine concepts of sustainment
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