Peristaltic Transport of a Physiological Fluid in an Asymmetric Porous Channel in the Presence of an External Magnetic Field

The paper deals with a theoretical investigation of the peristaltic transport of a physiological fluid in a porous asymmetric channel under the action of a magnetic field. The stream function, pressure gradient and axial velocity are studied by using appropriate analytical and numerical techniques. Effects of different physical parameters such as permeability, phase difference, wave amplitude and magnetic parameter on the velocity, pumping characteristics, streamline pattern and trapping are investigated with particular emphasis. The computational results are presented in graphical form. The results are found to be in perfect agreement with those of a previous study carried out for a non-porous channel in the absence of a magnetic field

Peristaltic Transport of a Couple Stress Fluid: Some Applications to Hemodynamics

The present paper deals with a theoretical investigation of the peristaltic transport of a couple stress fluid in a porous channel. The study is motivated towards the physiological flow of blood in the micro-circulatory system, by taking account of the particle size effect. The velocity, pressure gradient, stream function and frictional force of blood are investigated, when the Reynolds number is small and the wavelength is large, by using appropriate analytical and numerical methods. Effects of different physical parameters reflecting porosity, Darcy number, couple stress parameter as well as amplitude ratio on velocity profiles, pumping action and frictional force, streamlines pattern and trapping of blood are studied with particular emphasis. The computational results are presented in graphical form. The results are found to be in good agreement with those of Shapiro et. al \cite{r25} that was carried out for a non-porous channel in the absence of couple stress effect. The present study puts forward an important observation that for peristaltic transport of a couple stress fluid during free pumping when the couple stress effect of the fluid/Darcy permeability of the medium, flow reversal can be controlled to a considerable extent. Also by reducing the permeability it is possible to avoid the occurrence of trapping phenomenon

Electrochemical deprotonation of phosphate on stainless steel

Voltammetric experiments performed in phosphate buffer at constant pH 8.0 on platinum and stainless steel revealed clear reduction currents, which were correlated to the concentrations of phosphate. On the basis of the reactions proposed previously, a model was elaborated, assuming that both H2PO4 and HPO4 2 underwent cathodic deprotonation, and including the acid–base equilibriums. A kinetic model was derived by analogy with the equations generally used for hydrogen evolution. Numerical fitting of the experimental data confirmed that the phosphate species may act as an efficient catalyst of hydrogen evolution via electrochemical deprotonation. This reaction may introduce an unexpected reversible pathway of hydrogen formation in the mechanisms of anaerobic corrosion. The possible new insights offered by the electrochemical deprotonation of phosphate in microbially influenced corrosion was finally discussed

Early Detection of Critical Pulmonary Shunts in Infants

This paper aims to improve the design of modern Medical Cyber Physical Systems through the addition of supplemental noninvasive monitors. Specifically, we focus on monitoring the arterial blood oxygen content (CaO2), one of the most closely observed vital signs in operating rooms, currently measured by a proxy - peripheral hemoglobin oxygen saturation (SpO2). While SpO2 is a good estimate of O2 content in the finger where it is measured, it is a delayed measure of its content in the arteries. In addition, it does not incorporate system dynamics and is a poor predictor of future CaO2 values. Therefore, as a first step towards supplementing the usage of SpO2, this work introduces a predictive monitor designed to provide early detection of critical drops in CaO2 caused by a pulmonary shunt in infants. To this end, we develop a formal model of the circulation of oxygen and carbon dioxide in the body, characterized by unknown patient-unique parameters. Employing the model, we design a matched subspace detector to provide a near constant false alarm rate invariant to these parameters and modeling uncertainties. Finally, we validate our approach on real-patient data from lung lobectomy surgeries performed at the Children\u27s Hospital of Philadelphia. Given 198 infants, the detector predicted 81% of the critical drops in CaO2 at an average of about 65 seconds earlier than the SpO2-based monitor, while achieving a 0:9% false alarm rate (representing about 2 false alarms per hour)

Nutritional valuation of schoolchildren from three Ibero-American countries: A comparative analysis of the references proposed by International Obesity Task Force (IOTF) and World Health Organization (WHO)

Introducción: El índice de masa corporal (IMC) resulta un indicador útil para valorar la condición nutricional en la infancia y adolescencia. Si bien no existe consenso respecto a los valores o puntos de corte de IMC que deben utilizarse para la diagnosis del sobrepeso, la obesidad o la insuficiencia ponderal, las referencias propuestas por la Organización Mundial de la Salud (OMS) y la International Obesity Task Force (IOTF) son las más aceptadas. No obstante, existen discrepancias importantes en los resultados obtenidos en función de una u otra referencia. Objetivo: Analizar y comparar la condición nutricional de una muestra internacional a partir del IMC, mediante la aplicación simultánea de las referencias recomendadas por la IOTF y la OMS. Métodos: Se calculó el IMC de 1289 escolares de 10 a 13 años de México, Venezuela y España. A cada niño le fue atribuida una categoría nutricional (bajo peso, normopeso, sobrepeso y obesidad) utilizando el criterio de la IOTF (puntos de corte equivalentes a 18,5; 25 y 30 en adultos) y OMS (-1 DE: bajo peso + 1 DE: sobrepeso y +2 DE: obesidad). Las prevalencias de estado nutricional obtenidas por cada criterio fueron comparadas mediante la prueba de Chi-Cuadrado. Resultados: El porcentaje de escolares en cada una de las categorías nutricionales varió significativamente en función de la referencia empleada. La prevalencia de malnutrición por exceso o por defecto fue, en ambos sexos y en los tres países, superior al emplear los parámetros OMS. La referencia OMS evidenció un 10,9% menos de niños normonutridos y un 13,1% más de malnutridos que la IOTF. Discusión: Los resultados de esta investigación permiten inferir que la referencia propuesta por la OMS resulta ser más “preventiva” al momento de identificar individuos malnutridos. Se subraya la importancia de especificar los criterios empleados para la determinación del estado nutricional en los estudios de carácter epidemiológico, así como de contrastar las referencias empleadas para el diagnóstico. Conclusiones: Las referencias OMS para IMC sobrestiman la prevalencia de bajo peso, sobrepeso y obesidad en relación a los puntos de corte propuestos por el IOTF para el diagnóstico de la malnutrición.Introduction: Body Mass Index (BMI) is a useful tool for assessing nutritional status in childhood and adolescence. Although there is no consensus on BMI values or cutoffs to be used for the diagnosis of overweight, obesity and underweight references proposed by World Health Organization (WHO) and International Obesity Task Force (IOTF) are the most accepted. However, there are significant discrepancies in the results obtained in terms of either reference. Objective: To analyze and compare the nutritional status of an international sample from IMC, by simultaneous application of IOTF and WHO recommended references. Methods: 1289 schoolchildren’s BMI between 10 and 13 years of Mexico, Venezuela and Spain was estimated. Each child was assigned a nutritional category (underweight, normal weight, overweight and obese) using the IOTF criteria (points cut equivalent to 18,5, 25 and 30 in adults) and WHO (-1 SD: low weight +1 DE: overweight and +2 SD: obesity). The prevalence of nutritional status of each criterion was compared using the Chi-square test. Results: The percentage of students in each of the nutritional categories mottled significantly depending on the reference used. The prevalence of excess or defect malnutrition, in both sexes and in all three countries, was exceeded using the WHO parameters. WHO reference showed 10,9% less than well-nourished children and 13,1 % more malnourished than the IOTF. Discussion: The results of this research allow inferring that the reference proposed by WHO appears to be more “protecting” when identifying malnourished individuals. The importance of specifying the criteria for determination of nutritional status in epidemiologic studies, as well as to contrast the references used for diagnosis, is emphasized. Conclusions: The WHO BMI references overestimate the prevalence of underweight, overweight and obesity in relation to the cutoff points proposed by the IOTF for diagnosing malnutrition.Fil: Bergel Sanchís, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Cesani Rossi, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Cordero, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucuman. Instituto Superior de Estudios Sociales; ArgentinaFil: Navazo, Bárbara. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Departamento Científico de Antropología. Cátedra de Antropología Biológica Iv; ArgentinaFil: Olmedo, S.. Programa de Ecología Reproductiva del Gran Chaco Argentino. Formosa; ArgentinaFil: Quintero, F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Departamento Científico de Antropología. Cátedra de Antropología Biológica Iv; ArgentinaFil: Sardi, Marina Laura. Universidad Nacional de la Plata. Facultad de Cs.naturales y Museo. Departamento de Antropología; ArgentinaFil: Torres, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; Argentina. Universidad de Buenos Aires. Facultad de Filosofía y Letras; ArgentinaFil: Arechiga, J.. Universidad Nacional Autónoma de México; MéxicoFil: Méndez de Pérez, B. Universidad Nacional de Venezuela; VenezuelaFil: Marrodán, M. D.. Universidad Complutense de Madrid; Españ

Active management of the third stage of labour with and without controlled cord traction: a randomised, controlled, non-inferiority trial.

BACKGROUND: Active management of the third stage of labour reduces the risk of post-partum haemorrhage. We aimed to assess whether controlled cord traction can be omitted from active management of this stage without increasing the risk of severe haemorrhage. METHODS: We did a multicentre, non-inferiority, randomised controlled trial in 16 hospitals and two primary health-care centres in Argentina, Egypt, India, Kenya, the Philippines, South Africa, Thailand, and Uganda. Women expecting to deliver singleton babies vaginally (ie, not planned caesarean section) were randomly assigned (in a 1:1 ratio) with a centrally generated allocation sequence, stratified by country, to placental delivery with gravity and maternal effort (simplified package) or controlled cord traction applied immediately after uterine contraction and cord clamping (full package). After randomisation, allocation could not be concealed from investigators, participants, or assessors. Oxytocin 10 IU was administered immediately after birth with cord clamping after 1-3 min. Uterine massage was done after placental delivery according to local policy. The primary (non-inferiority) outcome was blood loss of 1000 mL or more (severe haemorrhage). The non-inferiority margin for the risk ratio was 1·3. Analysis was by modified intention-to-treat, excluding women who had emergency caesarean sections. This trial is registered with the Australian and New Zealand Clinical Trials Registry, ACTRN 12608000434392. FINDINGS: Between June 1, 2009, and Oct 30, 2010, 12,227 women were randomly assigned to the simplified package group and 12,163 to the full package group. After exclusion of women who had emergency caesarean sections, 11,861 were in the simplified package group and 11,820 were in the full package group. The primary outcome of blood loss of 1000 mL or more had a risk ratio of 1·09 (95% CI 0·91-1·31) and the upper 95% CI limit crossed the pre-stated non-inferiority margin. One case of uterine inversion occurred in the full package group. Other adverse events were haemorrhage-related. INTERPRETATION: Although the hypothesis of non-inferiority was not met, omission of controlled cord traction has very little effect on the risk of severe haemorrhage. Scaling up of haemorrhage prevention programmes for non-hospital settings can safely focus on use of oxytocin. FUNDING: United States Agency for International Development and UN Development Programme/UN Population Fund/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction, Department of Reproductive Health and Research

Harvesting Electricity with Geobacter bremensis Isolated from Compost

Electrochemically active (EA) biofilms were formed on metallic dimensionally stable anode-type electrode (DSA), embedded in garden compost and polarized at +0.50 V/SCE. Analysis of 16S rRNA gene libraries revealed that biofilms were heavily enriched in Deltaproteobacteria in comparison to control biofilms formed on non-polarized electrodes, which were preferentially composed of Gammaproteobacteria and Firmicutes. Among Deltaproteobacteria, sequences affiliated with Pelobacter and Geobacter genera were identified. A bacterial consortium was cultivated, in which 25 isolates were identified as Geobacter bremensis. Pure cultures of 4 different G. bremensis isolates gave higher current densities (1400 mA/m2 on DSA, 2490 mA/m2 on graphite) than the original multi-species biofilms (in average 300 mA/m2 on DSA) and the G. bremensis DSM type strain (100–300 A/m2 on DSA; 2485 mA/m2 on graphite). FISH analysis confirmed that G. bremensis represented a minor fraction in the original EA biofilm, in which species related to Pelobacter genus were predominant. The Pelobacter type strain did not show EA capacity, which can explain the lower performance of the multi-species biofilms. These results stressed the great interest of extracting and culturing pure EA strains from wild EA biofilms to improve the current density provided by microbial anodes