Influence of Matric Suction on the Shear Strength Behaviour of Unsaturated Sand

As a part of the effort made to understand the behaviour of unsaturated soils, this work studies the shear strength characteristics of a cohesionless unsaturated soil. Generally, the determination of the shear strength of unsaturated soils is a great challenge to geotechnical engineers, both in terms of understanding it and the effort necessary to determine it. Matric suction is one of the stress state variables that control the shear strength of unsaturated soils. Therefore, the main aim of this study is to investigate the effect of matric suction on the shear strength characteristic of sand known commercially as Sand PR33. The shear strength behaviour of unsaturated sand is studied in this work using the constant water content triaxial test method with measurements of matric suction during the shearing stage. The tests were performed using the axis translation technique in such a way that the pore-air pressure was controlled while the pore-water pressure was measured during all tests

A Numerical Model to Predict Matric Suction Inside Unsaturated Soils

The objective of this research is to introduce a numerical simulation model to predict approximate values of the matric suction inside unsaturated soils that have low water contents. The proposed model can be used to predict the relationship between the water content and the matric suction of a studied soil to construct the soil-water characteristic curve. In addition, the model can be utilized to combine the predicted matric suction with the soil parameters obtained experimentally, which enables us to explain how matric suction can affect the behaviour of unsaturated soils, without the need to utilize advanced measuring devices or special testing techniques. The model has given good results, especially when studying coarse-grained soils

Three Stage Cool Flame Droplet Burning Behavior of n-Alkane Droplets at Elevated Pressure Conditions: Hot, Warm and Cool Flame

Transient, isolated n-alkane droplet combustion is simulated at elevated pressure for helium-diluent substituted-air mixtures. We report the presence of unique quasi-steady, three-stage burning behavior of large sphero-symmetric n-alkane droplets at these elevated pressures and helium substituted ambient fractions. Upon initiation of reaction, hot-flame diffusive burning of large droplets is initiated that radiatively extinguishes to establish cool flame burning conditions in nitrogen/oxygen air at atmospheric and elevated pressures. However, at elevated pressure and moderate helium substitution for nitrogen ( X He > 20%), the initiated cool flame burning proceeds through two distinct, quasi-steady-state, cool flame burning conditions. The classical Hot flame ( 1500 K) radiatively extinguishes into a Warm flame burning mode at a moderate maximum reaction zone temperature ( 970 K), followed by a transition to a lower temperature ( 765 K), quasi-steady Cool flame burning condition. The reaction zone (flame) temperatures are associated with distinctly different yields in intermediate reaction products within the reaction zones and surrounding near-field, and the flame-standoff ratios characterizing each burning mode progressively decrease. The presence of all three stages first appears with helium substitution near 20%, and the duration of each stage is observed to be strongly dependent on helium substitutions level between 2060%. For helium substitution greater than 60%, the hot flame extinction is followed by only the lower temperature cool flame burning mode. In addition to the strong coupling between the diffusive loss of both energy and species and the slowly evolving degenerate branching in the low and negative temperature coefficient (NTC) kinetic regimes, the competition between the low-temperature chain branching and intermediate-temperature chain termination reactions control the Warm and Cool flame quasi-steady conditions and transitioning dynamics

A Simpler Method for Predicting Weight Loss in the First Year after Roux-en-Y Gastric Bypass

Factors postulated to predict weight loss after gastric bypass surgery, include race, age, gender, technique, height, and initial weight. This paper contained 1551 gastric bypass patients (85.9% female). Operations were performed by one surgeon (MLO) at community hospitals in Southern California from 1989 to 2008 with 314 being laparoscopic and 1237 open. We created the following equation: In[percent weight] = At2 − Bt, where t was the time after operation (days) and A and B are constants. Analysis was completed on R-software. The model fits with R2 value 0.93 and gives patients a realistic mean target weight with a confidence interval of 95% for the first year. Conclusion. We created a curve predicting weight loss after surgery as a percentage of initial weight. Initial weight was the single most important predictor of weight loss after surgery. Other recorded variables accounted for less than 1% of variability. Unknown factors account for the remaining 6-7%

Recurrence after correction of acquired ankle equinus deformity in children using Ilizarov technique

To describe our Ilizarov technique for the treatment of acquired equinus deformity in children and to determine if compliance with continuous use of an ankle foot orthosis (after removal of the fixator and until skeletal maturity) can influence the severity of recurrence. A cohort of 26 children with post-traumatic or post-burn contractures producing an equinus deformity was followed up for a minimum of 2 years after skeletal maturity. Cases with a bony deformity and/or nerve injury were excluded from this study. All patients were managed by a percutaneous tendo-Achilles lengthening followed by application of an Ilizarov external fixator. Post-operative treatment was in the form of gradual correction at a rate of 0.5 mm per day. Correction started from the second postoperative day until an over-correction of 15 degrees dorsiflexion was achieved. Ankle range of movement was encouraged 4 weeks prior to removal of the external fixator. On removal of the fixator, a posterior splint was applied until substituted by an ankle foot orthoses (AFO). The AFO was used continuously during the first 2–3 months and at nighttime thereafter until skeletal maturity. Fifteen children were compliant with the use of the AFO until skeletal maturity and 11 non-compliant. We compared the recurrence and the size of deformity between the two groups. The rate of recurrence, degree of equinus at recurrence and number of episodes of external fixation surgery showed statistical significant differences (P < 0.01) between the groups. The Ilizarov technique for treatment of acquired equinus deformity secondary to soft tissue scarring is a safe and effective technique. The use of an AFO until skeletal maturity can decrease the risk and degree of recurrence

Common mental disorders in mothers of children attending out-patient malnutrition clinics in rural North-western Nigeria: a cross-sectional study.

BACKGROUND: Children with uncomplicated severe acute malnutrition are managed routinely within out-patient malnutrition treatment programs. These programs do not offer maternal mental health support services, despite maternal mental health playing a significant role in the nutritional status of children. Additionally, the burden of maternal Common Mental Disorders (CMDs) is poorly described among mothers of children attending these programs. This study thus determined the burden and risk factors for maternal CMDs among children attending out-patient malnutrition clinics in rural North-western Nigeria. METHODS: We conducted a cross-sectional study among 204 mothers of children with severe acute malnutrition who attending eight out-patient malnutrition clinics in Jigawa, North-western Nigeria. We used the World Health Organization Self-Reporting Questionnaire-20 (WHO SRQ-20) screening tool, a recognised and validated proxy measure for CMDs to identify mothers with CMDs. The prevalence of maternal CMDs was determined by identifying the proportion of mothers with SRQ scores of ≥8. Risk factors for CMD were determined using multivariable logistic regression. RESULTS: Maternal CMD prevalence in children attending these facilities was high at 40.7%. Non-receipt of oral polio vaccine (OPV) (AOR 6.23, 95%CI 1.85 to 20.92) increased the odds for CMD. While spousal age above 40 (AOR 0.95, 95%CI 0.90 to 0.99) and long years spent married (AOR 0.92, 95%CI 0.85 to 0.98) decreased the odds for CMD. CONCLUSIONS: Our findings indicate maternal CMD burden is high in out-patient malnutrition clinics in North-western Nigeria. Maternal mental health services would need to be integrated into the community management of acute malnutrition programs to provide more holistic care, and possibly improve long-term outcomes after discharge from these programs

Factors associated with early growth in Egyptian infants: implications for addressing the dual burden of malnutrition.

Optimal nutrition is critical to the attainment of healthy growth, human capital and sustainable development. In Egypt, infants and young children face overlapping forms of malnutrition, including micronutrient deficiencies, stunting and overweight. Yet, in this setting, little is known about the factors associated with growth during the first year of life. A rise in stunting in Lower Egypt from 2005 to 2008 prompted this implementation research study, which followed a longitudinal cohort of infants from birth to 1 year of age within the context of a USAID-funded maternal and child health integrated programme. We sought to determine if growth patterns and factors related to early growth differed in Lower and Upper Egypt, and examined the relationship between weight loss and subsequent stunting at 12 months of age. Growth patterns revealed that length-for-age z-score (LAZ) decreased and weight-for-length z-score (WLZ) increased from 6 to 12 months of age in both regions. One-quarter of infants were stunted and nearly one-third were overweight by 12 months of age in lower Egypt. Minimum dietary diversity was significantly associated with WLZ in Lower Egypt (β = 0.22, P \u3c 0.05), but not in Upper Egypt. Diarrhoea, fever and programme exposure were not associated with any growth outcome. Weight loss during any period was associated with a twofold likelihood of stunting at 12 months in Lower Egypt, but not Upper Egypt. In countries, like Egypt, facing the nutrition transition, infant and young child nutrition programmes need to address both stunting and overweight through improving dietary quality and reducing reliance on energy-dense foods

Factors associated with early growth in Egyptian infants: implications for addressing the dual burden of malnutrition

Optimal nutrition is critical to the attainment of healthy growth, human capital and sustainable development. In Egypt, infants and young children face overlapping forms of malnutrition, including micronutrient deficiencies, stunting and overweight. Yet, in this setting, little is known about the factors associated with growth during the first year of life. A rise in stunting in Lower Egypt from 2005 to 2008 prompted this implementation research study, which followed a longitudinal cohort of infants from birth to 1 year of age within the context of a USAID-funded maternal and child health integrated programme. We sought to determine if growth patterns and factors related to early growth differed in Lower and Upper Egypt, and examined the relationship between weight loss and subsequent stunting at 12 months of age. Growth patterns revealed that length-for-age z-score (LAZ) decreased and weight-for-length z-score (WLZ) increased from 6 to 12 months of age in both regions. One-quarter of infants were stunted and nearly one-third were overweight by 12 months of age in lower Egypt. Minimum dietary diversity was significantly associated with WLZ in Lower Egypt (β = 0.22, P < 0.05), but not in Upper Egypt. Diarrhoea, fever and programme exposure were not associated with any growth outcome. Weight loss during any period was associated with a twofold likelihood of stunting at 12 months in Lower Egypt, but not Upper Egypt. In countries, like Egypt, facing the nutrition transition, infant and young child nutrition programmes need to address both stunting and overweight through improving dietary quality and reducing reliance on energy-dense foods

Plaguicidas y cáncer de mama en mujeres cordobesas

Exposure to environmental contaminants is an important public health problem, specially because of its possible carcinogenic effect. The raising incidence of cancer breast in Spain, together with the absence of clear association between this pathology and exposure to pesticides motivated us to assess the possible etiological role of pesticides in breast cancer development among women living in the province of Cordoba.We conducted a case-control study including women subjected to surgical interference because of breast lesions in Reina Sofia University Hospital. All women were subjected to interview questionnaire, histopathological study of the lump and determinations of four pesticides (HCB, HCH, p, p’DDE and Aldrin) in breast fat using gas chromatography.The histopathological study identified 69 women with malignant lesions (cases) and 65 women with benign lesions (controls). Analytic determination of the 4 pesticides detected high levels of p, p’DDE in all samples, followed by HCB and Aldrin and less levels and frequency of HCH.The univariate analysis identified the age, lactation period, and levels of Aldrin as risk factors for malignant lesions, meanwhile the multivariate analysis identified the levels of Aldrin as the most significant risk factor (p &lt; 0.001).Causal relation was found between Aldrin and breast cancer, suggesting the need for future studies taking in consideration possible confusion factors.La exposición a contaminantes ambientales constituye en la actualidad un problema importante en salud pública, sobre todo con respecto al papel que dichos tóxicos juegan como carcinogenéticos. Este hecho junto con la incidencia creciente del cáncer de mama en España y de que no existe una relación clara entre esta patología y la exposición a plaguicidas, conduce a plantearnos evaluar el papel de los plaguicidas como factor de riesgo en el cáncer de mama en mujeres cordobesas.Se realiza un estudio de casos-controles en 134 mujeres que fueron sometidas a intervenciones quirúrgicas por lesiones mamarias en el Hospital Universitario Reina Sofía de Córdoba. A todas se les realiza un cuestionario, así como un estudio anatomopatológico y determinaciones en grasa mamaria de cuatro plaguicidas (HCB, HCH, p,p’DDE y Aldrín) mediante cromatografía de gases.Tras el estudio anatomopatológico se estableció que 69 presentaban lesiones malignas (casos) y 65 lesiones benignas (controles). Las determinaciones analíticas respecto a los 4 plaguicidas, detectan niveles elevados de p,p’DDE en todas las muestras, seguidas del HCB y Aldrín y en menores niveles y muestras se detecta el HCH.El análisis univariante detectó la edad, duración de la lactancia y niveles de Aldrín como factores de riesgo en las lesiones malignas, pero el análisis multivariante identificó los niveles del pesticida Aldrín como el factor más significativo en dichas lesiones (p &lt; 0.001).Se establece la relación causal entre Aldrín y cáncer de mama, y se sugiere la necesidad de realizar nuevos estudios para eliminar los factores de confusión