2,005 research outputs found

    Efficient adaptive integration of functions with sharp gradients and cusps in n-dimensional parallelepipeds

    Full text link
    In this paper, we study the efficient numerical integration of functions with sharp gradients and cusps. An adaptive integration algorithm is presented that systematically improves the accuracy of the integration of a set of functions. The algorithm is based on a divide and conquer strategy and is independent of the location of the sharp gradient or cusp. The error analysis reveals that for a C0C^0 function (derivative-discontinuity at a point), a rate of convergence of n+1n+1 is obtained in RnR^n. Two applications of the adaptive integration scheme are studied. First, we use the adaptive quadratures for the integration of the regularized Heaviside function---a strongly localized function that is used for modeling sharp gradients. Then, the adaptive quadratures are employed in the enriched finite element solution of the all-electron Coulomb problem in crystalline diamond. The source term and enrichment functions of this problem have sharp gradients and cusps at the nuclei. We show that the optimal rate of convergence is obtained with only a marginal increase in the number of integration points with respect to the pure finite element solution with the same number of elements. The adaptive integration scheme is simple, robust, and directly applicable to any generalized finite element method employing enrichments with sharp local variations or cusps in nn-dimensional parallelepiped elements.Comment: 22 page

    Head lice infestation in school children of a low socioeconomy area of Tabriz city, Iran

    Get PDF
    Head lice infestation (HLI) caused by Pediculus humanus var capitis (Pediculus capitis) is a world wild public health concern that affects mostly school aged children. HLI does not produce an illness, but itis physically unpleasant and an unbearable social stigma. Over a five months period from July to November, 2006, 2795 school children from a low socio-economy area of Tabriz city enrolled in 13 elementary and high schools (governmental school) including 1948 girls (69.69 %) and 847 boys (30.30%) were examined for the presence of Pediculus capitis (nits, adults and immature). During this study all the infested cases were seen among girls and there was no infestation in boys. School girls aged 10-14 years constituted the highest infestation rate (6.5%) and the lowest infestation rate was seen in girls aged 15-18 years old (1.6%). The infestation rate in 5-9 years old children was 5.7%. The overall infestation rate in the studied population was 3.64%. There was a significant difference between infestation rates among the age groups X2 = 15.43, df = 2, p = 0.0004). But there was no significantdifference between the infestation rates of 5-9 and 10-14  groups(X2=0.36, df=1, p=0.55). Pediculosis is a public health issue in many parts of the world. Certainly, personal hygiene practices and socioeconomic status influence the level of prevalence of pediculosis. The lowest infestation rate in 15-18 years old children in this study may indicates that the better personal hygiene practices includingregular combing and washing of the hair is the main reason for reducing the head lice infestation rate in this group in comparison with the two other groups. The overall infestation rate in the present study isprobably one of the lowest infestation rates in Iran and in the region

    Is opioid dependency related to coping strategies?

    Get PDF
    Using opioid for recreational purposes has a very long history in Iran. Social influence is a useful framework in understanding how the social environment affects the individual's behavioral choices to use drugs. We compared opioid dependents (n=149) with controls (n=221) on measures of coping strategies using the Jalowiec Coping Scale and some socioeconomic factors. The differences in 10 of 15 coping strategies were significant in the study groups (P<0.05). Although, the combined score of problem-oriented and affective-oriented items did not show any significant difference between the two groups. There was a significant relation between opioid dependence with smoking cigarettes (P<0.001), lower education (P=0.002), being employed (P<0.001), having children (P<0.001), and being married (P<0.001). Educational programs to improve problem solving and coping skills can be helpful to reduce the rate of dependency to opioid and smoking cigarettes. © 2015, Sadeghali Taziki, et al

    Generalized Duffy transformation for integrating vertex singularities

    Get PDF
    For an integrand with a 1/r vertex singularity, the Duffy transformation from a triangle (pyramid) to a square (cube) provides an accurate and efficient technique to evaluate the integral. In this paper, we generalize the Duffy transformation to power singularities of the form p(x)/r α , where p is a trivariate polynomial and α &gt; 0 is the strength of the singularity. We use the map (u, v, w) → (x, y, z) : x = u β , y = x v, z = x w, and judiciously choose β to accurately estimate the integral. For α = 1, the Duffy transformation (β = 1) is optimal, whereas if α ≠ 1, we show that there are other values of β that prove to be substantially better. Numerical tests in two and three dimensions are presented that reveal the improved accuracy of the new transformation. Higher-order partition of unity finite element solutions for the Laplace equation with a derivative singularity at a re-entrant corner are presented to demonstrate the benefits of using the generalized Duffy transformation

    Decomposability in formal conformance testing

    Get PDF
    We study the problem of deriving a specification for a third-party component, based on the specification of the system and the environment in which the component is supposed to reside. Particularly, we are interested in using component specifications for conformance testing of black-box components, using the theory of input-output conformance (ioco) testing. We propose and prove sufficient criteria for decompositionality, i.e., that components conforming to the derived specification will always compose to produce a correct system with respect to the system specification. We also study the criteria for strong decomposability, by which we can ensure that only those components conforming to the derived specification can lead to a correct system

    Effects of Zataria multiflora and Eucalyptus globolus essential oils on haematological parameters and respiratory burst activity in Cyprinus carpio

    Get PDF
    The present study was undertaken to investigate the effects of Zataria multiflora and Eucalyptus globolus essential oils on some haematological parameters and respiratory burst activity in common carp (Cyprinus carpio). 260 fish (30±5g) were randomly distributed in 13 treatment groups; each one in three replicates and different doses of essential oils in 16-17ºC were administrated. The fish were sampled on day 1, 2, 8, 15 and 22 after the 8-day trial. Haematological parameters (red blood cell count, haematocrit) and respiratory burst activity were then evaluated in all treatment groups. The results suggest that essential oils especially Zataria multiflora in dietary intake significantly enhanced respiratory burst activity of blood neutrophlis (P< 0.05). Meanwhile, essential oils had moderate effects on RBC and haematocrit. Significant increases in RBC and haematocrit levels were just noted in T11 treatment group (P< 0.05). This study indicates that dietary administration of Zataria multiflora and Eucalyptus globolus essential oils could be used to promote the health status of common carp during temperature stress

    Coenzyme Q10 in the treatment of heart failure: A systematic review of systematic reviews

    Get PDF
    Introduction: This article is an attempt to provide an overview of systematic reviews to determine the efficacy of CQ10 supplementation in the treatment of patients with CVD. Method and material: All reviews were identified through a systematic search of the following databases: Cochrane, DARE, Ovid, EMBASE, ISI Web of Knowledge, and PubMed. Check references studies and the quality of the studies was assessed by means of AMSTTAR. No meta-analyses were performed due to the heterogeneity of studies. Result: Extracted data for Seven systematic reviews for primary outcomes, net changes in cardiac output, cardiac index, New York Heart Association functional classification, improved survival, based on existing evidence, there is a case for use of CoQ10 as an adjunctive therapy in congestive heart failure, especially in those patients unable to tolerate mainstream medical therapies. Conclusion: Evidence suggests that the CoQ10 supplement may be a useful tool for managing patients with heart failure. © 2018

    A high-order fully coupled electro-fluid-dynamics solver for multiphase flow simulations

    Get PDF
    A high-order discontinuous Galerkin Finite Element solver is developed for solving electro-fluid-dynamics problems. The solver is employed to perform numerical simulations of deformation of a droplet suspended in another immiscible liquid by applying steady and oscillatory electric fields. The level set method is adopted to represent the common interface of the droplet and surrounding medium. Electrostatics equation with a jump in the dielectric property at the interface is solved to find the electric field distribution. The incompressible Navier-Stokes equations including the surface tension force are solved to find the flow field. The Electrostatics and Navier-Stokes equations are coupled through changes in the geometry because of the deformation of the droplet and the dielectrophoretic body force, which is present at the interface

    Elevation of CD56brightCD16- lymphocytes in MDR pulmonary tuberculosis

    Get PDF
    Background: Protective immune responses induced in the majority of people infected with Mycobacterium tuberculosis enable them to control TB infection. Objective: The aim of this study was to investigate CD56 and CD16 positive peripheral blood mononuclear cells (PBMCs) and leukocyte subsets from multi-drug resistant pulmonary tuberculosis (MDR-TB), and compare them with nonresistant (NR) TB patients and healthy controls. Methods: 13 MDR-tuberculosis patients, 20 NR-TB individuals and 40 healthy subjects were included. Peripheral blood mononuclear cells were double stained with fluorochrome conjugated antibodies against CD56 and CD16 cell surface markers. The phenotype of positive cells was then analyzed by flow cytometry and the percent- ages of CD56+ CD16+, CD56- CD16+, CD56dimCD16+/-, and CD56brightCD16+/- subsets were calculated. Results: There was a significant decline in the percentage of CD56+CD16+ lymphocytes in both MDR and NR-TB patients compared with healthy controls. We also observed lower proportions of CD56dim/brightCD16+ in addition to higher percentages of CD56dim/brightCD16- subsets in all TB patients (p�0.05). In MDR- TB, our findings demonstrated a distinct phenotypic feature with increased levels of CD56brightCD16- in comparison with both NR-TB and healthy subjects. Conclusion: Considering the function of CD56/CD16 expressing cells in TB, we suggest that pheno- typic characteristics of PBMCs in MDR-TB may correlate with their status of drug re- sistance and probably with their high mortality rates
    corecore