Stochastic modeling of water movement in the saturated-unsaturated zone

A model for the one-dimensional transient water movement in the incorporated saturated-unsaturated zone was developed. Hysteresis in the soil water retention and hydraulic conductivity relationships was considered. The model considered layered geologic formations. The Monte Carlo method was used to incorporate the stochastic nature of hydraulic conductivity into the flow model. Outputs of the flow model include pressure head, water content at various depths, and the water table elevation. Outputs from the Monte Carlo simulation were used to predict the mean and standard deviation of those output variables;The major components of the flow model were the soil water flow, precipitation, infiltration, plant system, hydraulic conductivity, and soil water retention. The first order nearest neighbor model was used to handle the stochastic property of saturated hydraulic conductivity with the assumption that hydraulic conductivity was log normally distributed. Mualem\u27s conceptual model, with modification for higher order scanning curves, was used for the hysteretic soil water retention. The modified Holtan\u27s equation with Bailey\u27s iteration method was used for the infiltration component. Van Genuchten\u27s models for the relative hydraulic conductivity and soil water retention were used. An implicit method was used to solve for the pressure head based on the finite difference equation;Two Monte Carlo runs, consisting of 100 simulations each, were made varying the hydraulic conductivity distribution. The flow system consisted of 160 cm of soil divided into two sublayers. The spatial and temporal step sizes of 10 cm and 0.2 hour were used in the simulation. Input standard deviations of log saturated hydraulic conductivity used were 20% and 40% of the mean of log saturated conductivity. The Monte Carlo method was shown to be satisfactory when applied to study the stochastic flow problems

Effect of a Er, Cr:YSGG laser and a Er:YAG laser treatment on oral biofilm-contaminated titanium

Implant surface decontamination is a challenging procedure for therapy of peri-implant disease. Objective: This study aimed to compare the effectiveness of decontamination on oral biofilm-contaminated titanium surfaces in Er:YAG laser, Er, Cr:YSGG laser, and plastic curette. Methodology: For oral biofilms formation, six participants wore an acrylic splint with eight titanium discs in the maxillary arch for 72 hours. A total of 48 contaminated discs were distributed among four groups: untreated control; decontamination with plastic curettes; Er, Cr:YSGG laser; and Er:YAG laser irradiation. Complete plaque removal was estimated using naked-eye and the time taken was recorded; the residual plaque area was measured and the morphological alteration of the specimen surface was observed by scanning electron microscopy. The total bacterial load and the viability of adherent bacteria were quantified by live or dead cell labeling with fluorescence microscopy. Results: The mean treatment time significantly decreased based on the treatment used in the following order: Er:YAG, Er, Cr:YSGG laser, and plastic curettes (234.9±25.4 sec, 156.1±12.7 sec, and 126.4±18.6 sec, P=0.000). The mean RPA in the Er, Cr:YSGG laser group (7.0±2.5%) was lower than Er:YAG and plastic curettes groups (10.3±2.4%, 12.3±3.6%, p=0.023). The viable bacteria on the titanium surface after Er, Cr:YSGG laser irradiation was significantly lower compared to the decontamination with plastic curette (P=0.05) but it was not significantly different from the Er:YAG laser irradiation. Conclusion: We found that Er:YAG laser and Er, Cr:YSGG laser irradiation were effective methods for decontaminations without surface alterations

Soil heat and water flow with a partial surface mulch

A computer model using the alternating direction implicit (ADI) finite difference method to study two-dimensional coupled soil heat and water flow with a partial surface mulch cover is developed. A new, simplified computational procedure, which has only tridiagonal matrix problems, for the ADI method is introduced. The model uses a soil surface energy balance equation to determine soil surface boundary conditions for both heat and water flow. The inputs required for the computer simulations are weather data, soil thermal and hydraulic properties, and mulch data. Numerical experiments are performed to examine the effects of soil type, mulch width, and weather conditions on soil heat and water movement. For continuous evaporation and drainage, 10-day simulations were performed for each combination of clay, loam, and sand soil and fractions of mulch cover of 0, 0.5, 0.8, and 1.0 of the row interval width. For repetitive evaporation and infiltration, 15-day simulations were performed. The mulch cover greatly reduces evaporation loss and the amplitude of daily soil temperature, water content, and pressure head variations. Large spatial variations in temperature and soil water content are predicted near the interface of mulch and bare soil surface. The soil hydraulic properties have important roles in controlling soil surface water content. The present model reasonably describes the soil thermal and hydrologic environments and thus can be applied successfully in soil science and groundwater hydrology and can be extended to related disciplines

Why is son preference so persistent in East and South Asia? a cross-country study of China, India, and the Republic of Korea

Son preference has persisted in the face of sweeping economic and social changes in China, India, and the Republic of Korea. The authors attribute this to their similar family systems, which generate strong disincentives to raise daughters while valuing adult women's contributions to the household. Urbanization, female education, and employment can only slowly change these incentives without more direct efforts by the state and civil society to increase the flexibility of the kinship system such that daughters and sons can be perceived as being more equally valuable. Much can be done to this end through social movements, legislation, and the mass media.Gender and Development,Health Monitoring&Evaluation,Anthropology,Public Health Promotion,Population&Development,Adolescent Health,Anthropology,Life Sciences&Biotechnology,Health Monitoring&Evaluation,Population&Development

Incidental finding of a Sertoli-Leydig cell tumor in a postmenopausal woman with complex endometrial hyperplasia

Sertoli-Leydig cell tumors (SLCTs) arise from the non-germ cell component of the ovary and typically present in young women with evidence of hyperandrogenism such as precocious puberty, amenorrhea, hirsutism and virilization. It is very rare accounting for less than 0.2% of all ovarian tumors, and because of the rarity, no standardized treatment approach has reached a consensus. The prognosis is generally good with complete reversion of symptoms after surgery, although some cases have been reported to be malignant. Recently the need for DICER1 mutations testing in paediatric patients has been emphasized for the surveillance of possible synchronous tumors and affected family members. Authors present here a case of Sertoli-Leydig cell tumor incidentally found while performing a hysterectomy with bilateral salpingo-oophorectomy in a postmenopausal woman with endometrial hyperplasia that caused intractable vaginal bleeding

Algebraic Properties of Riemannian Manifolds

Algebraic properties are explored for the curvature tensors of Riemannian manifolds, using the irreducible decomposition of curvature tensors. Our method provides a powerful tool to analyze the irreducible basis as well as an algorithm to determine the linear dependence of arbitrary Riemann polynomials. We completely specify 13 independent basis elements for the quartic scalars and explicitly find 13 linear relations among 26 scalar invariants. Our method provides several completely new results, including some clues to identify 23 independent basis elements from 90 quintic scalars, that are difficult to find otherwise.Comment: A few typos corrected; 40 pages (4 appendices: 16 pages). To appear in General Relativity and Gravitatio

Effectiveness of an integrated adventure-based training and health education program in promoting regular physical activity among childhood cancer survivors

Background: There is growing concern about declining levels of physical activity in childhood cancer survivors. This study aimed to examine the effectiveness of an integrated adventure-based training and health education program in promoting changes in exercise behavior and enhancing the physical activity levels, self-efficacy, and quality of life of Hong Kong Chinese childhood cancer survivors. Methods: A randomized controlled trial, two-group pretest and repeated post-test, between-subjects design was conducted to 71 childhood cancer survivors (9- to 16-year-olds). Participants in the experimental group joined a 4-day integrated adventure-based training and health education program. Control group participants received the same amount of time and attention as the experimental group but not in such a way as to have any specific effect on the outcome measures. Participants' exercise behavior changes, levels of physical activity, self-efficacy, and quality of life were assessed at the time of recruitment, 3, 6, and 9 months after starting the intervention. Results: Participants in the experimental group reported statistically significant differences in physical activity stages of change (p < 0.001), higher levels of physical activity (p < 0.001) and self-efficacy (p = 0.04) than those in the control group. Besides, there were statistically significant mean differences (p < 0.001) in physical activity levels (-2.6), self-efficacy (-2.0), and quality of life (-4.3) of participants in the experimental group from baseline to 9 months after starting the intervention. Conclusions: The integrated adventure-based training and health education program was found to be effective in promoting regular physical activity among childhood cancer survivors. Copyright © 2013 John Wiley & Sons, Ltd.postprin