Flow Characteristics of Distinctly Viscous Multilayered Intestinal Fluid Motion

The goal of this investigation is to study the three layered (core layer, intermediate layer, and peripheral layer) tubular flow of power law fluids with variable viscosity by peristalsis in order to investigate the strength of the role played by an artificially generated intermediate layer to ease constipation. The solution is carried out under the long wavelength and low Reynolds number approximations in the wave frame of reference as the flow is creeping one. The stream functions for each layer such as core layer, intermediate layer, and peripheral layer are determined. The expressions for axial pressure gradient, interfaces, trapping, and reflux limits are obtained. The effects of power law index and viscosities on pressure across one wavelength, mechanical efficiency, and trapping are discussed numerically. It is found that the pressure required to restrain flow rates and the mechanical efficiency increase with the viscosities of the intermediate and peripheral layers as well as with the flow behaviour index. It is observed that the axisymmetric flow in intestines is less prone to constipation than two-dimensional flow and may be more easily overcome with introducing a viscous intermediate layer

PVP2004-3094 Computational Analysis of Heat Transfer Enhancement Due to Rectangular Ribs in a Turbulent Duct Flow

ABSTRACT A computational analysis of heat transfer enhancement due to artificial roughness in the form of rectangular ribs has been carried out. A turbulence model is selected by comparing the predictions of different turbulence models with experimental results available in the literature. A detailed analysis of heat transfer variation within inter rib region is done by using the selected turbulence model. The analysis shows that peak in local heat transfer coefficient occurs at the point of reattachment of the separated flow as observed experimentally. The results predict a significant enhancement of heat transfer in comparison to that for a smooth surface. There is a good matching between the predictions by SST k-w and experimental results

Deoxyfluorination tunes the aggregation of cellulose and chitin oligosaccharides and highlights the role of specific hydroxyl groups in the crystallization process

Cellulose and chitin are abundant structural polysaccharides exploited by nature in a large number of applications thanks to their crystallinity. Chemical modifications are commonly employed to tune polysaccharide physical and mechanical properties, but generate heterogeneous mixtures. Thus, the effect of such modifications is not well understood at the molecular level. In this work, we examined how deoxyfluorination (site and pattern) impact the solubility and aggregation of well-defined cellulose and chitin oligomers. While deoxyfluorination increased solubility in water and lowered the crystallinity of cellulose oligomers, chitin was much less affected by the modification. The OH/F substitution also highlighted the role of specific hydroxyl groups in the crystallization process. This work provides guidelines for the design of cellulose- and chitin-based materials. A similar approach can be imagined to prepare cellulose and chitin analogues capable of withstanding enzymatic degradation

Transcriptomic resources for evolutionary studies in flat periwinkles and related species

The flat periwinkles, Littorina fabalis and L. obtusata, comprise two sister gastropod species that have an enormous potential to elucidate the mechanisms involved in ecological speciation in the marine realm. However, the molecular resources currently available for these species are still scarce. In order to circumvent this limitation, we used RNA-seq data to characterize the transcriptome of four individuals from each species sampled in different locations across the Iberian Peninsula. Four de novo transcriptome assemblies were generated, as well as a pseudo-reference using the L. saxatilis reference transcriptome as backbone. After transcripts’ annotation, variant calling resulted in the identification of 19,072 to 45,340 putatively species-diagnostic SNPs. The discriminatory power of a subset of these SNPs was validated by implementing an independent genotyping assay to characterize reference populations, resulting in an accurate classification of individuals into each species and in the identification of hybrids between the two. These data comprise valuable genomic resources for a wide range of evolutionary and conservation studies in flat periwinkles and related taxa

Effectiveness of female community health volunteers in the detection and management of low-birth-weight in Nepal

Introduction: Low birth weight (LBW) is a major risk factor for neonatal death. However, most neonates in low-income countries are not weighed at birth. This results in many LBW infants being overlooked. Female community health volunteers (FCHVs) in Nepal are non-health professionals who are living in local communities and have already worked in a field of reproductive and child health under the government of Nepal for more than 20 years. The effectiveness of involving FCHVs to detect LBW infants and to initiate prompt action for their care was studied in rural areas of Nepal. Methods: FCHVs were tasked with weighing all neonates born in selected areas using color-coded spring scales. Supervisors repeated each weighing using electronic scales as the gold standard comparator. Data on the relative birth sizes of the infants, as assessed by their mothers, were also collected and compared with the measured weights. Each of the 205 FCHVs involved in the study was asked about the steps that she would take when she came across a LBW infant, and knowledge of zeroing a spring scale was also assessed through individual interviews. The effect of the background social characteristics of the FCHVs on their performance was examined by logistic regression. This study was nested within a community-based neonatal sepsis-management intervention surveillance system, which facilitated an assessment of the performance of the FCHVs in weighing neonates, coverage of FCHVs’ visits, and weighing of babies through maternal interviews. Results: A total of 462 babies were weighed, using both spring scales and electronic scales, within 72 hours of birth. The prevalence of LBW, as assessed by the gold standard method, was 28%. The sensitivity of detection of LBW by FCHVs was 89%, whereas the sensitivity of the mothers’ perception of size at birth was only 40%. Of the 205 FCHVs participating in the study, 70% of FCHVs understood what they should do when they identified LBW and very low birth weight (VLBW) infants. Ninety-six per cent could describe how to zero a scale and approximately 50% could do it correctly. Seventy-seven per cent of FCHVs weighed infants at least once during the study period, and 19 of them (12%) miscategorized infant weights. Differences were not detected between the background social characteristics of FCHVs who miscategorized infants and those who did not. On the basis of maternal reporting, 67% of FCHVs who visited infants had weighed them. Conclusions: FCHVs are able to correctly identify LBW and VLBW infants using spring scales and describe the correct steps to take after identification of these infants. Use of FCHVs as newborn care providers allows for utilization of their logistical, geographical, and cultural strengths, particularly a high level of access to neonates, that can complement the Nepalese healthcare system. Providing additional training to and increasing supervision of local FCHVs regarding birth weight measurement will increase the identification of high-risk neonates in resource-limited settings

Cross-sectional study of asthma and rhinitis symptoms in the context of exposure to air pollution in Nepal

Asthma is common in children worldwide, although its prevalence varies substantially by location. The prevalence of wheeze over a 12-month period ranged from 2.1% to 32.2% in the older age group (13–14 years) and 4.1% to 32.1% in the younger age group (6–7 years) [1]. There is a positive association between current symptoms of asthma in younger and older children with gross national income [2], and it is generally slightly less common in girls than boys in the younger group [1–3]. Exposure to air pollution is associated with asthma exacerbations. Odds ratios for wheeze in the past year and the use of solely an open fire for cooking were 2.17 (95% CI 1.64–2.87) for children aged 6–7 years and 1.35 (95% CI 1.11–1.64) for children aged 13–14 years [4]. Nepalese children are exposed to high levels of indoor air pollution from the burning of biomass fuels [5]. This study aimed to estimate their prevalence of asthma, and to investigate the association of air pollution and risk of wheeze and rhinitis symptoms using personal exposure estimates of air pollution

Eff ect of antenatal multiple micronutrient supplementation on anthropometry and blood pressure in mid-childhood in Nepal: follow-up of a double-blind randomised controlled trial

Background In 2002–04, we did a randomised controlled trial in southern Nepal, and reported that children born to mothers taking multiple micronutrient supplements during pregnancy had a mean birthweight 77 g greater than children born to mothers taking iron and folic acid supplements. Children born to mothers in the study group were a mean 204 g heavier at 2·5 years of age and their systolic blood pressure was a mean 2·5 mm Hg lower than children born to mothers in the control group. We aimed to follow up the same children to mid-childhood (age 8·5 years) to investigate whether these diff erences would be sustained. Methods For this follow-up study, we identifi ed children from the original trial and measured anthropometry, body composition with bioelectrical impedance (with population-specifi c isotope calibration), blood pressure, and renal dimensions by ultrasound. We documented socioeconomic status, household food security, and air pollution. Main outcomes of the follow-up at 8 years were Z scores for weight-for-age, height-for-age, and body-mass index (BMI)-forage according to WHO Child Growth Standards for children aged 5–19 years, and blood pressure. This study is registered with the International Standard Randomised Controlled Trial register, number ISRCTN88625934. Findings Between Sept 21, 2011, and Dec 7, 2012, we assessed 841 children (422 in the control group and 419 in the intervention group). Unadjusted diff erences (intervention minus control) in Z scores were 0·05 for weight-for-age (95% CI –0·09 to 0·19), 0·02 in height-for-age (–0·10 to 0·15), and 0·04 in BMI-for-age (–0·09 to 0·18). We recorded no diff erence in blood pressure. Adjusted diff erences were similar for all outcomes. Interpretation We recorded no diff erences in phenotype between children born to mothers who received antenatal multiple micronutrient or iron and folate supplements at age 8·5 years. Our fi ndings did not extend to physiological diff erences or potential longer-term eff ects