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Sample records for general epidemiological parameters

  1. General epidemiological parameters of viral hepatitis A, B, C, and E in six regions of China: a cross-sectional study in 2007.

    Science.gov (United States)

    Lu, Jian; Zhou, Yongdong; Lin, Xiaojing; Jiang, Yongzhen; Tian, Ruiguang; Zhang, Yonghui; Wu, Jia; Zhang, Fengwei; Zhang, Yong; Wang, Yue; Bi, Shengli

    2009-12-24

    Viral hepatitis is a serious health burden worldwide. To date, few reports have addressed the prevalence of hepatitis A, B, C, and E in China. Therefore, the general epidemiological parameters of viral hepatitis remain unknown. In this cross-sectional study, we performed a serological prevalence analysis of viral hepatitis A, B, C, and E in 8,762 randomly selected Chinese subjects, which represented six areas of China. The overall prevalence of anti-Hepatitis C virus antibody (anti-HCV) was 0.58%, which was much lower than was estimated by WHO. The prevalences of Hepatitis B virus surface antigen (HBsAg), anti-Hepatitis B virus surface protein antibody (HBsAb), and anti-Hepatitis B virus core protein antibody (HBcAb) were 5.84%, 41.31%, and 35.92%, respectively, whereas in the group of subjects less than 5 years old, these prevalences were 1.16%, 46.77%, and 8.69% respectively, which suggests that the Hepatitis B virus (HBV)-carrier population is decreasing, and the nationwide HBV vaccine program has contributed to the lowered HBV prevalence in the younger generation in China. Meanwhile, a large deficit remains in coverage provided by the national HBV immune program. In addition, our data suggested the possibility that HBsAb may not last long enough to protect people from HBV infection throughout life. The overall prevalence of anti-Hepatitis A virus antibody (anti-HAV) and anti-Hepatitis E virus antibody (anti-HEV) were as high as 72.87% and 17.66%, respectively. The indices increased with age, which suggests that a large proportion of Chinese adults are protected by latent infection. Furthermore, the pattern of HEV infection was significantly different among ethnic groups in China. Our study provided much important information concerning hepatitis A, B, C, and E prevalence in China and will contribute to worldwide oversight of viral hepatitis.

  2. Parameter Estimation in Epidemiology: from Simple to Complex Dynamics

    Science.gov (United States)

    Aguiar, Maíra; Ballesteros, Sebastién; Boto, João Pedro; Kooi, Bob W.; Mateus, Luís; Stollenwerk, Nico

    2011-09-01

    We revisit the parameter estimation framework for population biological dynamical systems, and apply it to calibrate various models in epidemiology with empirical time series, namely influenza and dengue fever. When it comes to more complex models like multi-strain dynamics to describe the virus-host interaction in dengue fever, even most recently developed parameter estimation techniques, like maximum likelihood iterated filtering, come to their computational limits. However, the first results of parameter estimation with data on dengue fever from Thailand indicate a subtle interplay between stochasticity and deterministic skeleton. The deterministic system on its own already displays complex dynamics up to deterministic chaos and coexistence of multiple attractors.

  3. Assessment of epidemiological parameters and their use in epidemiological and forecasting models of cereal airborne diseases

    DEFF Research Database (Denmark)

    Vallavieille-Pope, C. de; Giosue, S.; Munk, L.

    2000-01-01

    Assessments of epidemiological parameters (e.g. infection efficiency, latent period, spore production) are required for the prediction of epidemic progress, for the estimation of components of partial resistance for different host plant cultivars and for the estimation of fitness components of pa...

  4. Assessment of epidemiological parameters and their use in epidemiological and forecasting models of cereal airborne diseases

    DEFF Research Database (Denmark)

    Vallavieille-Pope, C. de; Giosue, S.; Munk, L.

    2000-01-01

    Assessments of epidemiological parameters (e.g. infection efficiency, latent period, spore production) are required for the prediction of epidemic progress, for the estimation of components of partial resistance for different host plant cultivars and for the estimation of fitness components...

  5. Parameter space of general gauge mediation

    Energy Technology Data Exchange (ETDEWEB)

    Rajaraman, Arvind [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: arajaram@uci.edu; Shirman, Yuri [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: yshirman@uci.edu; Smidt, Joseph [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: jsmidt@uci.edu; Yu, Felix [Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)], E-mail: felixy@uci.edu

    2009-07-27

    We study a subspace of General Gauge Mediation (GGM) models which generalize models of gauge mediation. We find superpartner spectra that are markedly different from those of typical gauge and gaugino mediation scenarios. While typical gauge mediation predictions of either a neutralino or stau next-to-lightest supersymmetric particle (NLSP) are easily reproducible with the GGM parameters, chargino and sneutrino NLSPs are generic for many reasonable choices of GGM parameters.

  6. Parameter and uncertainty estimation for mechanistic, spatially explicit epidemiological models

    Science.gov (United States)

    Finger, Flavio; Schaefli, Bettina; Bertuzzo, Enrico; Mari, Lorenzo; Rinaldo, Andrea

    2014-05-01

    Epidemiological models can be a crucially important tool for decision-making during disease outbreaks. The range of possible applications spans from real-time forecasting and allocation of health-care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. Our spatially explicit, mechanistic models for cholera epidemics have been successfully applied to several epidemics including, the one that struck Haiti in late 2010 and is still ongoing. Calibration and parameter estimation of such models represents a major challenge because of properties unusual in traditional geoscientific domains such as hydrology. Firstly, the epidemiological data available might be subject to high uncertainties due to error-prone diagnosis as well as manual (and possibly incomplete) data collection. Secondly, long-term time-series of epidemiological data are often unavailable. Finally, the spatially explicit character of the models requires the comparison of several time-series of model outputs with their real-world counterparts, which calls for an appropriate weighting scheme. It follows that the usual assumption of a homoscedastic Gaussian error distribution, used in combination with classical calibration techniques based on Markov chain Monte Carlo algorithms, is likely to be violated, whereas the construction of an appropriate formal likelihood function seems close to impossible. Alternative calibration methods, which allow for accurate estimation of total model uncertainty, particularly regarding the envisaged use of the models for decision-making, are thus needed. Here we present the most recent developments regarding methods for parameter and uncertainty estimation to be used with our mechanistic, spatially explicit models for cholera epidemics, based on informal measures of goodness of fit.

  7. Generalized Schur functions and augmented Schur parameters

    NARCIS (Netherlands)

    Dijksma, Aad; Wanjala, Gerald; Forster, KH; Jonas, P; Langer, H

    2006-01-01

    Every Schur function s(z) is the uniform limit of a sequence of finite Blaschke products on compact subsets of the open unit disk. The Blaschke products in the sequence are defined inductively via the Schur parameters of s(z). In this note we prove a similar result for generalized Schur functions.

  8. General collision branching processes with two parameters

    Institute of Scientific and Technical Information of China (English)

    CHEN AnYue; LI JunPing

    2009-01-01

    A new class of branching models, the general collision branching processes with two parameters, is considered in this paper. For such models, it is necessary to evaluate the absorbing probabilities and mean extinction times for both absorbing states. Regularity and uniqueness criteria are firstly established. Explicit expressions are then obtained for the extinction probability vector, the mean extinction times and the conditional mean extinction times. The explosion behavior of these models is investigated and an explicit expression for mean explosion time is established. The mean global holding time is also obtained. It is revealed that these properties are substantially different between the super-explosive and sub-explosive cases.

  9. Regularization Parameter Selections via Generalized Information Criterion.

    Science.gov (United States)

    Zhang, Yiyun; Li, Runze; Tsai, Chih-Ling

    2010-03-01

    We apply the nonconcave penalized likelihood approach to obtain variable selections as well as shrinkage estimators. This approach relies heavily on the choice of regularization parameter, which controls the model complexity. In this paper, we propose employing the generalized information criterion (GIC), encompassing the commonly used Akaike information criterion (AIC) and Bayesian information criterion (BIC), for selecting the regularization parameter. Our proposal makes a connection between the classical variable selection criteria and the regularization parameter selections for the nonconcave penalized likelihood approaches. We show that the BIC-type selector enables identification of the true model consistently, and the resulting estimator possesses the oracle property in the terminology of Fan and Li (2001). In contrast, however, the AIC-type selector tends to overfit with positive probability. We further show that the AIC-type selector is asymptotically loss efficient, while the BIC-type selector is not. Our simulation results confirm these theoretical findings, and an empirical example is presented. Some technical proofs are given in the online supplementary material.

  10. General collision branching processes with two parameters

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A new class of branching models,the general collision branching processes with two parameters,is considered in this paper.For such models,it is necessary to evaluate the absorbing probabilities and mean extinction times for both absorbing states.Regularity and uniqueness criteria are firstly established.Explicit expressions are then obtained for the extinction probability vector,the mean extinction times and the conditional mean extinction times.The explosion behavior of these models is investigated and an explicit expression for mean explosion time is established.The mean global holding time is also obtained.It is revealed that these properties are substantially different between the super-explosive and sub-explosive cases.

  11. On generalized trigonometric functions with two parameters

    OpenAIRE

    Bhayo, Barkat Ali; Vuorinen, Matti

    2011-01-01

    The generalized $p$-trigonometric and ($p,q$)-trigonometric functions were introduced by P. Lindqvist and S. Takeuchi, respectively. We prove some inequalities and present a few conjectures for the ($p,q$)-functions.

  12. Generalized M-Fluctuation Tests for Parameter Instability

    OpenAIRE

    Zeileis, Achim; Hornik, Kurt

    2003-01-01

    A general class of fluctuation tests for parameter instability in an M-estimation framework is suggested. The tests are based on partial sum processes of M-estimation scores for which functional central limit theorems are derived under the null hypothesis of parameter stability and local alternatives. Special emphasis is given to parameter instability in (generalized) linear regression models and it is shown that the introduced M-fluctuation tests contain a large number of parameter instabili...

  13. Inferring epidemiological parameters from phylogenetic information for the HIV-1 epidemic among MSM

    Science.gov (United States)

    Quax, Rick; van de Vijver, David A. M. C.; Frentz, Dineke; Sloot, Peter M. A.

    2013-09-01

    The HIV-1 epidemic in Europe is primarily sustained by a dynamic topology of sexual interactions among MSM who have individual immune systems and behavior. This epidemiological process shapes the phylogeny of the virus population. Both fields of epidemic modeling and phylogenetics have a long history, however it remains difficult to use phylogenetic data to infer epidemiological parameters such as the structure of the sexual network and the per-act infectiousness. This is because phylogenetic data is necessarily incomplete and ambiguous. Here we show that the cluster-size distribution indeed contains information about epidemiological parameters using detailed numberical experiments. We simulate the HIV epidemic among MSM many times using the Monte Carlo method with all parameter values and their ranges taken from literature. For each simulation and the corresponding set of parameter values we calculate the likelihood of reproducing an observed cluster-size distribution. The result is an estimated likelihood distribution of all parameters from the phylogenetic data, in particular the structure of the sexual network, the per-act infectiousness, and the risk behavior reduction upon diagnosis. These likelihood distributions encode the knowledge provided by the observed cluster-size distrbution, which we quantify using information theory. Our work suggests that the growing body of genetic data of patients can be exploited to understand the underlying epidemiological process.

  14. Parameter Estimation for a Computable General Equilibrium Model

    DEFF Research Database (Denmark)

    Arndt, Channing; Robinson, Sherman; Tarp, Finn

    2002-01-01

    We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of non-linear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...

  15. Parameter Estimation for a Computable General Equilibrium Model

    DEFF Research Database (Denmark)

    Arndt, Channing; Robinson, Sherman; Tarp, Finn

    We introduce a maximum entropy approach to parameter estimation for computable general equilibrium (CGE) models. The approach applies information theory to estimating a system of nonlinear simultaneous equations. It has a number of advantages. First, it imposes all general equilibrium constraints...

  16. Sieve likelihood ratio inference on general parameter space

    Institute of Scientific and Technical Information of China (English)

    SHEN Xiaotong; SHI Jian

    2005-01-01

    In this paper,a theory on sieve likelihood ratio inference on general parameter spaces(including infinite dimensional) is studied.Under fairly general regularity conditions,the sieve log-likelihood ratio statistic is proved to be asymptotically x2 distributed,which can be viewed as a generalization of the well-known Wilks' theorem.As an example,a emiparametric partial linear model is investigated.

  17. The epidemiology of suicide and attempted suicide in Dutch general practice 1983-2003.

    NARCIS (Netherlands)

    Marquet, R.L.; Bartelds, A.I.M.; Kerkhof, A.J.F.M.; Schellevis, F.G.; Zee, J. van der

    2005-01-01

    BACKGROUND: Many patients attempting or committing suicide consult their general practitioner (GP) in the preceding period, indicating that GPs might play an important role in prevention. The aim of the present study was to analyse the epidemiology of suicidal behaviour in Dutch general practice in

  18. The epidemiology of suicide and attempted suicide in Dutch general practice 1983-2003.

    NARCIS (Netherlands)

    Marquet, R.L.; Bartelds, A.I.M.; Kerkhof, A.J.F.M.; Schellevis, F.G.; Zee, J. van der

    2005-01-01

    BACKGROUND: Many patients attempting or committing suicide consult their general practitioner (GP) in the preceding period, indicating that GPs might play an important role in prevention. The aim of the present study was to analyse the epidemiology of suicidal behaviour in Dutch general practice in

  19. Epidemiology of carbapenemase producing Enterobacteriaceae in a general hospital

    Directory of Open Access Journals (Sweden)

    Amina Kandeel

    2015-06-01

    Full Text Available Objective: Detect the presence of carbapenemases producing Enterobacteriaceae (CPE and associated epidemiologi­cal, microbiological, and clinical characteristics of patients in our hospital Methods: During 15 months period, all non duplicate Enterobacteriaceae isolates with reduced susceptibility to car­bapenem detected by MicroScan WalkAway system and confirmed by E test were collected. These suspected isolates were further screened by modified Hodge test and carbapenemase inhibition discs to identify CPE. Results: Out of 54 suspected Enterobacteriaceae isolates, 44 (88.5% isolates were either extended spectrum beta-lac­tamases (ESBLs or AmpC producers with porin loss whereas 10 isolates (18.5% were confirmed to produce carbapen­emase representing (0.74% of the total Enterobacteriaceae. Among these 10 isolates, 6 were OXA 48 producers and 2 isolates were class B and class A each. Six out of the 10 CPE were detected in ICU and specimen source was tracheal aspirate in 5 CPE isolates. All CPE isolates were sensitive to colistin and all but one to tigecycline. All patients had history of previous antibiotic exposure and hospital stays for more than 5 days. Conclusion: Although CPE is not the main cause of carbapenem resistance in Enterobacteriaceae in our setting, its emergence there represents a serious infection control and therapeutic challenge. This mandates its early detection using MHT and carbapenemase inhibition tests together with strict infection control measures to limit its spread. J Mi­crobiol Infect Dis 2015;5(2: 57-62

  20. Learning regularization parameters for general-form Tikhonov

    Science.gov (United States)

    Chung, Julianne; Español, Malena I.

    2017-07-01

    Computing regularization parameters for general-form Tikhonov regularization can be an expensive and difficult task, especially if multiple parameters or many solutions need to be computed in real time. In this work, we assume training data is available and describe an efficient learning approach for computing regularization parameters that can be used for a large set of problems. We consider an empirical Bayes risk minimization framework for finding regularization parameters that minimize average errors for the training data. We first extend methods from Chung et al (2011 SIAM J. Sci. Comput. 33 3132-52) to the general-form Tikhonov problem. Then we develop a learning approach for multi-parameter Tikhonov problems, for the case where all involved matrices are simultaneously diagonalizable. For problems where this is not the case, we describe an approach to compute near-optimal regularization parameters by using operator approximations for the original problem. Finally, we propose a new class of regularizing filters, where solutions correspond to multi-parameter Tikhonov solutions, that requires less data than previously proposed optimal error filters, avoids the generalized SVD, and allows flexibility and novelty in the choice of regularization matrices. Numerical results for 1D and 2D examples using different norms on the errors show the effectiveness of our methods.

  1. Linear generalized synchronization of chaotic systems with uncertain parameters

    Institute of Scientific and Technical Information of China (English)

    Jia Zhen

    2008-01-01

    A more general form of projective synchronization,so called linear generalized synchronization(LGS)is proposed,which includes the generalized projective synchronization(GPS)and the hybrid projective synchronization(HPS)as its special cases.Based on the adaptive technique and Lyapunov stability theory,a general method for achieving the LGS between two chaotic or hyperchaotic systems with uncertain parameters in any scaling matrix is presented.Some numerical simulations are provided to show the effectiveness and feasibility of the proposed synchronization method.

  2. The epidemiology of teaching and training General Practices in England.

    Science.gov (United States)

    Rees, Eliot L; Gay, Simon P; McKinley, Robert K

    2016-11-01

    There is no national picture of teaching and training practices or the communities they serve. We aimed to describe the association between general practices' engagement with education and their characteristics, locality and patients' health-status and satisfaction. This data linkage study of all English practices calculated odds ratios for teaching and training status and practice, locality and patient variables. Teaching and training practices are larger than practices which do neither (mean list size (SD) 7074 (3736), 10112 (4934), and 5327 (3368) respectively, p quality and outcomes framework scores (0.507 (0.211, 0.804)) and (0.996 (0.650, 1.342)) respectively than those which did not. Educationally engaged practices are unrepresentative in serving less ethnically diverse and (for training practices) less urban environments. Investment is needed to increase the proportion of educational practices in diverse urban localities.

  3. Contemporary epidemiology of gout in the UK general population

    Science.gov (United States)

    2011-01-01

    Introduction The objective of this study was to investigate the contemporary incidence of gout, examine potential risk factors, and evaluate specific gout treatment patterns in the general population. Methods Using the health improvement network (THIN) UK primary care database, we estimated the incidence of gout based on 24,768 newly diagnosed gout patients among a cohort of 1,775,505 individuals aged 20 to 89 years between 2000 and 2007. We evaluated potential risk factors for incident gout in a nested case-control study with 50,000 controls frequency-matched by age, sex and calendar time. We calculated odds ratios (OR) by means of unconditional logistic regression adjusting for demographic variables, lifestyle variables, relevant medical conditions and drug exposures. Results The incidence of gout per 1,000 person-years was 2.68 (4.42 in men and 1.32 in women) and increased with age. Conventional risk factors were significantly and strongly associated with the risk of gout, with multivariate ORs of 3.00 (95% confidence interval (CI)) for excessive alcohol intake (that is, more than 42 units per week), 2.34 (95% CI 2.22 to 2.47) for obesity (body mass index > = 30 kg/m2), 2.48 (95% CI 2.19 to 2.81) for chronic renal impairment, and 3.00 (95% CI 2.85 to 3.15) for current diuretic use. For other medical conditions the multivariate OR were 1.84 (95% CI 1.70 to 2.00) for heart failure, 1.45 (95% CI 1.18 to 1.79) for hypertriglyceridemia and 1.12 (95% CI 1.04 to 1.22) for psoriasis. Use of cyclosporine was associated with an OR of 3.72 (95% CI, 2.17 to 6.40). Among gout-specific therapies, allopurinol was the most frequently used with a one-year cumulative incidence of 28% in a cohort of incident gout diagnosed from 2000 to 2001. Use of gout-specific treatment has not changed over recent years except for an increase of colchicine. Conclusions The contemporary incidence of gout in UK remains substantial. In this general population cohort, associations with previously

  4. Epidemiology of Hepatitis C Virus in Bangladeshi General Population

    Directory of Open Access Journals (Sweden)

    Mamun Al-Mahtab

    2009-11-01

    Full Text Available Background: Hepatitis C virus is encountered sporadically in Bangladesh. It results in a wide range liver diseases, with asymptomatic acute hepatitis rarely at one end to HCC at the other end of the spectrum. Methods: 1018 individuals of different age groups and sex with varied religious, educational and social backgrounds were tested for anti-HCV by ELISA. Before testing, blood samples were preserved at -20°C. The study was conducted in a semi-urban location on the outskirts of Dhaka. Results: 0.88% tested positive for anti HCV. None of them tested positive for HBsAg. There was a male predominance and those who tested positive were mostly between 17 and 50 years of age. Major risk factors for exposure to HBV appeared to be injudicious use of injectable medications, treatment by unqualified, traditional practitioners, mass-vaccination against cholera and smallpox, barbers and body piercing. Conclusion: HCV remains an important cause of morbidity and mortality in Bangladesh. Key words: HCV; prevalence; general population; Bangladesh.DOI: 10.3329/bsmmuj.v2i1.3705 BSMMU J 2009; 2(1: 14-17

  5. Parameter Estimation for Generalized Brownian Motion with Autoregressive Increments

    CERN Document Server

    Fendick, Kerry

    2011-01-01

    This paper develops methods for estimating parameters for a generalization of Brownian motion with autoregressive increments called a Brownian ray with drift. We show that a superposition of Brownian rays with drift depends on three types of parameters - a drift coefficient, autoregressive coefficients, and volatility matrix elements, and we introduce methods for estimating each of these types of parameters using multidimensional times series data. We also cover parameter estimation in the contexts of two applications of Brownian rays in the financial sphere: queuing analysis and option valuation. For queuing analysis, we show how samples of queue lengths can be used to estimate the conditional expectation functions for the length of the queue and for increments in its net input and lost potential output. For option valuation, we show how the Black-Scholes-Merton formula depends on the price of the security on which the option is written through estimates not only of its volatility, but also of a coefficient ...

  6. Estimating epidemiological parameters for bovine tuberculosis in British cattle using a Bayesian partial-likelihood approach.

    Science.gov (United States)

    O'Hare, A; Orton, R J; Bessell, P R; Kao, R R

    2014-05-22

    Fitting models with Bayesian likelihood-based parameter inference is becoming increasingly important in infectious disease epidemiology. Detailed datasets present the opportunity to identify subsets of these data that capture important characteristics of the underlying epidemiology. One such dataset describes the epidemic of bovine tuberculosis (bTB) in British cattle, which is also an important exemplar of a disease with a wildlife reservoir (the Eurasian badger). Here, we evaluate a set of nested dynamic models of bTB transmission, including individual- and herd-level transmission heterogeneity and assuming minimal prior knowledge of the transmission and diagnostic test parameters. We performed a likelihood-based bootstrapping operation on the model to infer parameters based only on the recorded numbers of cattle testing positive for bTB at the start of each herd outbreak considering high- and low-risk areas separately. Models without herd heterogeneity are preferred in both areas though there is some evidence for super-spreading cattle. Similar to previous studies, we found low test sensitivities and high within-herd basic reproduction numbers (R0), suggesting that there may be many unobserved infections in cattle, even though the current testing regime is sufficient to control within-herd epidemics in most cases. Compared with other, more data-heavy approaches, the summary data used in our approach are easily collected, making our approach attractive for other systems.

  7. Estimating parameters for generalized mass action models with connectivity information

    Directory of Open Access Journals (Sweden)

    Voit Eberhard O

    2009-05-01

    Full Text Available Abstract Background Determining the parameters of a mathematical model from quantitative measurements is the main bottleneck of modelling biological systems. Parameter values can be estimated from steady-state data or from dynamic data. The nature of suitable data for these two types of estimation is rather different. For instance, estimations of parameter values in pathway models, such as kinetic orders, rate constants, flux control coefficients or elasticities, from steady-state data are generally based on experiments that measure how a biochemical system responds to small perturbations around the steady state. In contrast, parameter estimation from dynamic data requires time series measurements for all dependent variables. Almost no literature has so far discussed the combined use of both steady-state and transient data for estimating parameter values of biochemical systems. Results In this study we introduce a constrained optimization method for estimating parameter values of biochemical pathway models using steady-state information and transient measurements. The constraints are derived from the flux connectivity relationships of the system at the steady state. Two case studies demonstrate the estimation results with and without flux connectivity constraints. The unconstrained optimal estimates from dynamic data may fit the experiments well, but they do not necessarily maintain the connectivity relationships. As a consequence, individual fluxes may be misrepresented, which may cause problems in later extrapolations. By contrast, the constrained estimation accounting for flux connectivity information reduces this misrepresentation and thereby yields improved model parameters. Conclusion The method combines transient metabolic profiles and steady-state information and leads to the formulation of an inverse parameter estimation task as a constrained optimization problem. Parameter estimation and model selection are simultaneously carried out

  8. The epidemiology of hand eczema in the general population--prevalence and main findings

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Johansen, Jeanne D; Linneberg, Allan;

    2010-01-01

    . This study aimed to review the epidemiology of hand eczema in the general population. Literature was examined using Pubmed-Medline, Biosis, Science Citation Index, and dermatology text books. On the basis of studies performed between 1964 and 2007, the point prevalence of hand eczema was around 4%, the 1...

  9. Adaptive generalized functional synchronization of Chaotic systems with unknown parameters

    Institute of Scientific and Technical Information of China (English)

    Wang Dong-Feng; Han Pu

    2008-01-01

    A universal adaptive generalized functional synchronization approach to any two different or identical chaotic systems with unknown parameters is proposed,based on a unified mathematical expression of a large class of chaotic system.Self-adaptive parameter law and control law are given in the form of a theorem.The synchronization between the three-dimensional R(o)ssler chaotic system and the four-dimensional Chen's hyper-chaotic system is studied as an example for illustration.The computer simulation results demonstrate the feasibility of the method proposed.

  10. Testing for one Generalized Linear Single Order Parameter

    DEFF Research Database (Denmark)

    Ellegaard, Niels Langager; Christensen, Tage Emil; Dyre, Jeppe

    work the order parameter may be chosen to have a non-exponential relaxation. The model predictions contradict the general consensus of the properties of viscous liquids in two ways: (i) The model predicts that following a linear isobaric temperature step, the normalized volume and entalpy relaxation...... functions are identical. This assumption conflicts with some (but not all) reports, utilizing the Tool-Narayanaswamy formalism to extrapolate from non-linear measurements to the linear regime. (ii) The model predicts that the theoretical "linear Prigogine-Defay" ratio is one. This ratio has never been...... responses or extrapolate from measurements of a glassy state away from equilibrium. Starting from a master equation description of inherent dynamics, we calculate the complex thermodynamic response functions. We device a way of testing for the generalized single order parameter model by measuring 3 complex...

  11. [Genetic epidemiology of schizophrenia in the population of Tomsk Oblast. Dependence of parameters of the occurrence of schizophrenia among relatives on the method of proband sample formation].

    Science.gov (United States)

    Ritsner, M S; Karas', S I; Sherina, O L; Boiarintseva, I G; Gutkevich, E V

    1989-04-01

    The program of genetic-epidemiological study of schizophrenia in five districts of the Tomsk region is presented. According to standardized methods, 610 diagnosed patients (epidemiological register) were examined, 74.1% of them being at random registered as probands (452 families of the epidemiological sample). 229 probands of non-epidemiological sample were registered in psychiatric hospitals. Schizophrenia occurrence parameters among first-degree relatives of probands of the non-epidemiological sample were regularly overestimated, as compared to the epidemiological sample. The methodical sources of contradictions in clinico-genealogical studies are discussed; the conclusion about representativeness+ of the probands' epidemiological sample is made.

  12. Constitution and monitoring of an epidemiological surveillance network with sentinel general practitioners.

    Science.gov (United States)

    Chauvin, P

    1994-08-01

    The Réseau National Télé-informatique de surveillance et d'information sur les Maladies Transmissibles (RNTMT) (French communicable diseases computerised surveillance network) comprises a network of sentinel general practitioners (SGP). These benevolent volunteers are responsible for the weekly epidemiological surveillance. Since its creation, 1,700 SGPs have participated in the RNTMT, representing a total of more than 120,000 connections to the RNTMT telematic service center. The principal motivation of these benevolent SGPs was to 'actively participate in public health', although only a minority of them (17.6%) had any training in this field. Such a system, based on the benevolent and voluntary activity of SGPs, requires a good understanding of SGPs' attitudes towards epidemiological surveillance in general and the tool used, in order to quantitatively and qualitatively follow their participation and to provide regular and useful feedback to the surveillance actors.

  13. Inversion of generalized relaxation time distributions with optimized damping parameter

    Science.gov (United States)

    Florsch, Nicolas; Revil, André; Camerlynck, Christian

    2014-10-01

    Retrieving the Relaxation Time Distribution (RDT), the Grains Size Distribution (GSD) or the Pore Size Distribution (PSD) from low-frequency impedance spectra is a major goal in geophysics. The “Generalized RTD” generalizes parametric models like Cole-Cole and many others, but remains tricky to invert since this inverse problem is ill-posed. We propose to use generalized relaxation basis function (for instance by decomposing the spectra on basis of generalized Cole-Cole relaxation elements instead of the classical Debye basis) and to use the L-curve approach to optimize the damping parameter required to get smooth and realistic inverse solutions. We apply our algorithm to three examples, one synthetic and two real data sets, and the program includes the possibility of converting the RTD into GSD or PSD by choosing the value of the constant connecting the relaxation time to the characteristic polarization size of interest. A high frequencies (typically above 1 kHz), a dielectric term in taken into account in the model. The code is provided as an open Matlab source as a supplementary file associated with this paper.

  14. A review of epidemiological parameters from Ebola outbreaks to inform early public health decision-making.

    Science.gov (United States)

    Van Kerkhove, Maria D; Bento, Ana I; Mills, Harriet L; Ferguson, Neil M; Donnelly, Christl A

    2015-01-01

    The unprecedented scale of the Ebola outbreak in West Africa has, as of 29 April 2015, resulted in more than 10,884 deaths among 26,277 cases. Prior to the ongoing outbreak, Ebola virus disease (EVD) caused relatively small outbreaks (maximum outbreak size 425 in Gulu, Uganda) in isolated populations in central Africa. Here, we have compiled a comprehensive database of estimates of epidemiological parameters based on data from past outbreaks, including the incubation period distribution, case fatality rate, basic reproduction number (R 0 ), effective reproduction number (R t ) and delay distributions. We have compared these to parameter estimates from the ongoing outbreak in West Africa. The ongoing outbreak, because of its size, provides a unique opportunity to better understand transmission patterns of EVD. We have not performed a meta-analysis of the data, but rather summarize the estimates by virus from comprehensive investigations of EVD and Marburg outbreaks over the past 40 years. These estimates can be used to parameterize transmission models to improve understanding of initial spread of EVD outbreaks and to inform surveillance and control guidelines.

  15. The epidemiology of hand eczema in the general population--prevalence and main findings

    DEFF Research Database (Denmark)

    Thyssen, Jacob P; Johansen, Jeanne D; Linneberg, Allan

    2010-01-01

    Numerous studies have investigated the prevalence and risk factors of hand eczema in the general population. These studies are of high value as they tend to be less biased than studies using clinical populations and as they are important for healthcare decision makers when they allocate resources....... This study aimed to review the epidemiology of hand eczema in the general population. Literature was examined using Pubmed-Medline, Biosis, Science Citation Index, and dermatology text books. On the basis of studies performed between 1964 and 2007, the point prevalence of hand eczema was around 4%, the 1......-year prevalence nearly 10%, whereas the lifetime prevalence reached 15%. Based on seven studies, the median incidence rate of hand eczema was 5.5 cases/1000 person-years (women = 9.6 and men = 4.0). A high incidence rate was associated with female sex, contact allergy, atopic dermatitis, and wet work...

  16. A general method of estimating stellar astrophysical parameters from photometry

    CERN Document Server

    Belikov, A N

    2008-01-01

    Applying photometric catalogs to the study of the population of the Galaxy is obscured by the impossibility to map directly photometric colors into astrophysical parameters. Most of all-sky catalogs like ASCC or 2MASS are based upon broad-band photometric systems, and the use of broad photometric bands complicates the determination of the astrophysical parameters for individual stars. This paper presents an algorithm for determining stellar astrophysical parameters (effective temperature, gravity and metallicity) from broad-band photometry even in the presence of interstellar reddening. This method suits the combination of narrow bands as well. We applied the method of interval-cluster analysis to finding stellar astrophysical parameters based on the newest Kurucz models calibrated with the use of a compiled catalog of stellar parameters. Our new method of determining astrophysical parameters allows all possible solutions to be located in the effective temperature-gravity-metallicity space for the star and se...

  17. EPIPOI: A user-friendly analytical tool for the extraction and visualization of temporal parameters from epidemiological time series

    Directory of Open Access Journals (Sweden)

    Alonso Wladimir J

    2012-11-01

    Full Text Available Abstract Background There is an increasing need for processing and understanding relevant information generated by the systematic collection of public health data over time. However, the analysis of those time series usually requires advanced modeling techniques, which are not necessarily mastered by staff, technicians and researchers working on public health and epidemiology. Here a user-friendly tool, EPIPOI, is presented that facilitates the exploration and extraction of parameters describing trends, seasonality and anomalies that characterize epidemiological processes. It also enables the inspection of those parameters across geographic regions. Although the visual exploration and extraction of relevant parameters from time series data is crucial in epidemiological research, until now it had been largely restricted to specialists. Methods EPIPOI is freely available software developed in Matlab (The Mathworks Inc that runs both on PC and Mac computers. Its friendly interface guides users intuitively through useful comparative analyses including the comparison of spatial patterns in temporal parameters. Results EPIPOI is able to handle complex analyses in an accessible way. A prototype has already been used to assist researchers in a variety of contexts from didactic use in public health workshops to the main analytical tool in published research. Conclusions EPIPOI can assist public health officials and students to explore time series data using a broad range of sophisticated analytical and visualization tools. It also provides an analytical environment where even advanced users can benefit by enabling a higher degree of control over model assumptions, such as those associated with detecting disease outbreaks and pandemics.

  18. The role of epidemiological quality parameters in a mammography screening programme; Die Rolle der epidemiologischen Qualitaetsparameter im Mammographie-Screeningprogramm

    Energy Technology Data Exchange (ETDEWEB)

    Becker, N. [Deutsches Krebsforschungszentrum, Heidelberg (Germany). Abt. Klinische Epidemiologie

    2006-11-15

    In the recently established mammography screening programme, for the first time in Germany an extensive data collection for prompt quantification of specified quality parameters will be intrinsic to an early detection programme. Epidemiological parameters taken from the European Guidelines are central. This article outlines how epidemiology is involved in quality assurance of cancer screening and why epidemiological quality indicators will be quantified. The reasons for focussing on those parameters, on which the European Guidelines and now the German programme are based, and their significance in the long-term effectiveness of this programme are explained. (orig.) [German] Bei dem gerade im Aufbau begriffenen Mammographie-Screeningprogramm wird erstmalig in Deutschland eine umfangreiche Datenerhebung zur zeitnahen Quantifizierung bestimmter Qualitaetsparameter zum integralen Bestandteil eines Frueherkennungsprogramms. Ein Herzstueck dieser in europaeischen Richtlinien festgelegten und in das deutsche Programm uebernommenen Parameter sind epidemiologische Groessen. In dem vorliegenden Beitrag wird dargestellt, weshalb im Kontext der Qualitaetssicherung von Krebsfrueherkennung die Epidemiologie eine Rolle spielt, und warum epidemiologische Qualitaetsparameter zu quantifizieren sind. Darauf aufbauend wird erlaeutert, aus welchen Gruenden man gerade diejenigen Groessen gewaehlt hat, die im Zentrum der europaeischen Richtlinien und nun auch der Qualitaetssicherung des deutschen Programms stehen, und was sie hinsichtlich der langfristigen Effektivitaet des Programms aussagen. (orig.)

  19. Parameter Estimation for a Computable General Equilibrium Model

    DEFF Research Database (Denmark)

    Arndt, Channing; Robinson, Sherman; Tarp, Finn

    . Second, it permits incorporation of prior information on parameter values. Third, it can be applied in the absence of copious data. Finally, it supplies measures of the capacity of the model to reproduce the historical record and the statistical significance of parameter estimates. The method is applied...

  20. On a six-parameter generalized Burr XII distribution

    OpenAIRE

    A. K. Olapade

    2008-01-01

    In this paper, we derive a probability density function that generalizes the Burr XII distribution. The cumulative distribution function and the $n^{th}$ moment of the generalized distribution are obtained while the distribution of some order statistics of the distribution are established. A theorem that relate the new distribution to another statistical distribution is established.

  1. Neuropathic pain in the general population: a systematic review of epidemiological studies.

    Science.gov (United States)

    van Hecke, O; Austin, Sophie K; Khan, Rafi A; Smith, B H; Torrance, N

    2014-04-01

    Most patients with neuropathic pain symptoms present and are managed in primary care, with only a minority being referred for specialist clinical assessment and diagnoses. Previous reviews have focused mainly on specific neuropathic pain conditions based in specialist settings. This is the first systematic review of epidemiological studies of neuropathic pain in the general population. Electronic databases were searched from January 1966 to December 2012, and studies were included where the main focus was on neuropathic pain prevalence and/or incidence, either as part of a specific neuropathic pain-related condition or as a global entity in the general population. We excluded studies in which data were extracted from pain or other specialist clinics or focusing on specific population subgroups. Twenty-one articles were identified and underwent quality assessment and data extraction. Included studies differed in 3 main ways: method of data retrieval, case ascertainment tool used, and presentation of prevalence/incidence rates. This heterogeneity precluded any meta-analysis. We categorised comparable incidence and prevalence rates into 2 main subgroups: (1) chronic pain with neuropathic characteristics (range 3-17%), and (2) neuropathic pain associated with a specific condition, including postherpetic neuralgia (3.9-42.0/100,000 person-years [PY]), trigeminal neuralgia (12.6-28.9/100,000 PY), painful diabetic peripheral neuropathy (15.3-72.3/100,000 PY), glossopharyngeal neuralgia (0.2-0.4/100,000 PY). These differences highlight the importance of a standardised approach for identifying neuropathic pain in future epidemiological studies. A best estimate of population prevalence of pain with neuropathic characteristics is likely to lie between 6.9% and 10%. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  2. Adaptive generalized projective synchronization of two different chaotic systems with unknown parameters

    Institute of Scientific and Technical Information of China (English)

    Zhang Ruo-Xun; Yang Shi-Ping

    2008-01-01

    This paper presents a general method of the generalized projective synchronization and the parameter identification between two different chaotic systems with unknown parameters.This approach is based on Lyapunov stability theory,and employs a combination of feedback control and adaptive control.With this method one can achieve the generalized projective synchronization and realize the parameter identifications between almost all chaotic (hyperchaotic) systems with unknown parameters.Numerical simulations results are presented to demonstrate the effectiveness of the method.

  3. Epidemiology of Giant Cell Tumor in Dr. Hasan Sadikin General Hospital Bandung from 2010-2013

    Directory of Open Access Journals (Sweden)

    Kirtana Gunasegaran

    2016-06-01

    Full Text Available Background: Giant cell tumor (GCT of bone is a primary bone tumor. It is commonly seen in South East Asia and found in female around 20–45 years old. The GCT mostly occurs in epiphysis around the knee. The patients normally suffer from pain, swelling, limitation of joint movement, and pathologic fracture. This study aimed to determine the epidemiology of GCT of the bone based on age, sex, location, type, metastases, and recurrence in Dr. Hasan Sadikin General Hospital Bandung. Methods: A descriptive study with retrospective cohort using total sampling method was used to obtain 33 medical records of patients with GCT of bone in Department of Orthopedic & Traumatology and Anatomical Pathology Dr. Hasan Sadikin General Hospital Bandung in the period of January 2010–December 2013. Results: The GCT of bone was mostly found in female of 20 to 29 years old and around 32 years old in male. Distal femur will be the most common site while zygoma, mandibular vertebrae, proximal tibia were rare sites. Twenty nine cases were benign lesion and the rest (4 cases were malignant. The probability of GCT of bone to metastasize to lungs was very low. Four recurrences occurred within a year. Conclusions: The GCT of bone in male mostly occurs in the third and fourth decade of age. It is found around the knee, mostly benign, rarely metastasize to the lungs and recurrence happens within a year.

  4. On Parameters Estimation of Lomax Distribution under General Progressive Censoring

    Directory of Open Access Journals (Sweden)

    Bander Al-Zahrani

    2013-01-01

    Full Text Available We consider the estimation problem of the probability S=P(Ygeneral progressive censored data. The maximum likelihood estimator and Bayes estimators are obtained using the symmetric and asymmetric balanced loss functions. The Markov chain Monte Carlo (MCMC methods are used to accomplish some complex calculations. Comparisons are made between Bayesian and maximum likelihood estimators via Monte Carlo simulation study.

  5. Clinical and epidemiological aspects of generalized meningococcal infections in children and adolescents of Saint-Petersburg

    Directory of Open Access Journals (Sweden)

    Yu. V. Lobzin

    2016-01-01

    Full Text Available Generalized meningococcal infection belongs to the group of diseases with a high risk of initiation of life-threatening conditions and death outcomes. There was carried out a retrospective analysis of clinical and epidemiological features of generalized meningococcal infections in children and adolescents of Saint Petersburg in 1995–2014 on the basis of the analysis of 884 medical records of the patients hospitalized at Scientific Research Institute of Children’s Infections. With general prevalence of the children of the first years of life among the patients, there has been revealed the tendency to reduction in the portion of children of the first year of life from 41,4% in 1995 to 22,2% by 2014, and the increase in the number of patients of 1–3 years old from 19,3–30,5% in 1995–1996 to 46,4–46,4% in 2013–2014. Among the number of etiologically identified cases (59,4% the majority of them has been caused by serogroup B meningococcus (58,5%, in 24,2% – by serogroup C meningococcus, in 11,2% – by serogroup A meningococcus, and in 6,1% – by rare (W135/Y and unspecified strains N.meningitidis. Within the recent years there has been identified the tendency of rate growth concerning the diseases caused by serogroup C meningococci, remarkable for a severe course and high rate of death cases. Total death indicator for the investigated period has averaged 4,2%, with the variability from 0 to 12,5% for different years.

  6. Evaluation of oxidative and antioxidative parameters in generalized anxiety disorder.

    Science.gov (United States)

    Emhan, Ali; Selek, Salih; Bayazıt, Hüseyin; Fatih Karababa, İbrahim; Katı, Mahmut; Aksoy, Nurten

    2015-12-30

    Generalized anxiety disorder (GAD) is a prevalent psychiatric disorder. The exact causes of GAD still unknown, in addition to neurochemical and neuroanatomic disorders, genetic and environmental factors are discussed in etiology. In our study we aimed to evaluate the oxidative metabolism's status and investigate the role of oxidative metabolites in GAD. Blood samples were taken from enrolled subjects in appropriate way and total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) were studied in Harran University Biochemistry Labs. Results were compared between groups. The patients' TOS and OSI levels were significantly higher than control group. The patients' TAS levels were significantly lower than controls'. According to our findings, oxidative stress mechanism might have a role in GAD pathophysiology. In the future, total antioxidants may be used as a biologic marker in GAD etiology but more research is needed.

  7. [Clinical and epidemiological characteristics of humeral supracondylar fractures in pediatric patients in a Regional General Hospital].

    Science.gov (United States)

    Barrón-Torres, Erika Alejandrina; Sánchez-Cruz, Juan Francisco; Cruz-Meléndez, José Ramses

    2015-01-01

    Supracondylar humerus fractures are common in children between 5-7 years of age and more frequent in the males, 90-95% of these fractures are in extension mechanism, the urgency of immediate attention is to prevent complications and sequelae. To establish the clinical and epidemiological profile of supracondylar humerus fractures, in a General Regional Hospital from the Instituto Mexicano del Seguro Social in Yucatan Mexico, during 2011-2013. A cross-sectional study. Strength association was measured by odds ratios and statistical significance with chi(2) test, p value was considered in < 0.05 RESULTS: 56 cases were analyzed, the mean age was 2.6 ± 5.33 years, the mechanism of injury was falling over at home, male gender is associated with extent injure mechanism (OR 5.6, 95% CI 1.0-30.1, p = 0.03), we observed that at most time elapsed between injury and medical means more hospital days (r = 0.40; p = 0.002), surgical treatment was established in 44 cases (78.6%), 18 (40.9%) with closed technique and placement of cloves and 26 (59.1%) with open reduction, in 100% cross configuration was used, ten complications were reported. Supracondylar humerus fractures are a common injury in children, males are more likely to be injured by extension, and the speed in medical treatment is an important issue. Copyright © 2015. Published by Masson Doyma México S.A.

  8. The epidemiology of hand eczema in the general population--prevalence and main findings.

    Science.gov (United States)

    Thyssen, Jacob P; Johansen, Jeanne D; Linneberg, Allan; Menné, Torkil

    2010-02-01

    Numerous studies have investigated the prevalence and risk factors of hand eczema in the general population. These studies are of high value as they tend to be less biased than studies using clinical populations and as they are important for healthcare decision makers when they allocate resources. This study aimed to review the epidemiology of hand eczema in the general population. Literature was examined using Pubmed-Medline, Biosis, Science Citation Index, and dermatology text books. On the basis of studies performed between 1964 and 2007, the point prevalence of hand eczema was around 4%, the 1-year prevalence nearly 10%, whereas the lifetime prevalence reached 15%. Based on seven studies, the median incidence rate of hand eczema was 5.5 cases/1000 person-years (women = 9.6 and men = 4.0). A high incidence rate was associated with female sex, contact allergy, atopic dermatitis, and wet work. Atopic dermatitis was the single most important risk factor for hand eczema. Hand eczema resulted in medical consultations in 70%, sick leave (> 7 days) in about 20%, and job change in about 10%. Mean sick time was longer among those with allergic hand eczema than those with atopic and irritant hand eczema. Moderate to severe extension of hand eczema was the strongest risk factor for persistence of hand eczema. Other risk factors included early onset of hand eczema and childhood eczema. The aetiology of hand eczema is multifactorial and includes environmental as well as genetic factors. Future studies should focus on unresolved areas of hand eczema, for example, genetic predisposition.

  9. The epidemiology of suicide and attempted suicide in Dutch general practice 1983–2003

    Science.gov (United States)

    Marquet, Richard L; Bartelds, Aad IM; Kerkhof, Ad JFM; Schellevis, François G; van der Zee, Jouke

    2005-01-01

    Background Many patients attempting or committing suicide consult their general practitioner (GP) in the preceding period, indicating that GPs might play an important role in prevention. The aim of the present study was to analyse the epidemiology of suicidal behaviour in Dutch General Practice in order to find possible clues for prevention. Method Description of trends in suicide and suicide attempts occurring from 1983–2003 in the Dutch General Practice Sentinel Network, representing 1% of the Dutch population. The data were analysed with regard to: 1) suicidal behaviour trends and their association with household situation; 2) presence of depression, treatment of depression and referral rate by GPs; 3) contact with GP before suicide or suicide attempt and discussion of suicidal ideation. Results Between 1983 and 2003 the annual number of suicide and suicide attempts decreased by 50%. Sixty percent of the patients who committed or attempted suicide were diagnosed as depressed, of whom 91% were treated by their GP with an antidepressant. Living alone was a risk factor for suicide (odds ratio 1.99; 95% CI 1.50 to 2.64), whereas living in a household of 3 or more persons was a relative risk for a suicide attempt (odds ratio 1.81; 95% CI 1.34 to 2.46). Referral to a psychiatrist or other mental health professionals occurred in 65% of the cases. GPs recalled having discussed suicidal ideation in only 7% of the cases, and in retrospect estimated that they had foreseen suicide or suicide attempts in 31% and 22% of the cases, respectively, if there had been contact in the preceding month. Conclusion With regard to the prescription of antidepressants and referral of suicidal patients to a psychiatrist, Dutch GPs fulfil their role as gatekeeper satisfactorily. However, since few patients discuss their suicidal ideation with their GP, there is room for improvement. GPs should take the lead to make this subject debatable. It may improve early recognition of depressed

  10. The epidemiology of suicide and attempted suicide in Dutch general practice 1983–2003

    Directory of Open Access Journals (Sweden)

    Schellevis François G

    2005-11-01

    Full Text Available Abstract Background Many patients attempting or committing suicide consult their general practitioner (GP in the preceding period, indicating that GPs might play an important role in prevention. The aim of the present study was to analyse the epidemiology of suicidal behaviour in Dutch General Practice in order to find possible clues for prevention. Method Description of trends in suicide and suicide attempts occurring from 1983–2003 in the Dutch General Practice Sentinel Network, representing 1% of the Dutch population. The data were analysed with regard to: 1 suicidal behaviour trends and their association with household situation; 2 presence of depression, treatment of depression and referral rate by GPs; 3 contact with GP before suicide or suicide attempt and discussion of suicidal ideation. Results Between 1983 and 2003 the annual number of suicide and suicide attempts decreased by 50%. Sixty percent of the patients who committed or attempted suicide were diagnosed as depressed, of whom 91% were treated by their GP with an antidepressant. Living alone was a risk factor for suicide (odds ratio 1.99; 95% CI 1.50 to 2.64, whereas living in a household of 3 or more persons was a relative risk for a suicide attempt (odds ratio 1.81; 95% CI 1.34 to 2.46. Referral to a psychiatrist or other mental health professionals occurred in 65% of the cases. GPs recalled having discussed suicidal ideation in only 7% of the cases, and in retrospect estimated that they had foreseen suicide or suicide attempts in 31% and 22% of the cases, respectively, if there had been contact in the preceding month. Conclusion With regard to the prescription of antidepressants and referral of suicidal patients to a psychiatrist, Dutch GPs fulfil their role as gatekeeper satisfactorily. However, since few patients discuss their suicidal ideation with their GP, there is room for improvement. GPs should take the lead to make this subject debatable. It may improve early

  11. Epidemiological pattern of tattoo skin disease: a potential general health indicator for cetaceans.

    Science.gov (United States)

    Van Bressem, Marie-Françoise; Van Waerebeek, Koen; Aznar, Francisco Javier; Raga, Juan Antonio; Jepson, Paul D; Duignan, Pádraig; Deaville, Rob; Flach, Leonardo; Viddi, Francisco; Baker, John R; Di Beneditto, Ana Paula; Echegaray, Mónica; Genovo, Tilen; Reyes, Julio; Felix, Fernando; Gaspar, Raquel; Ramos, Renata; Peddemors, Vic; Sanino, Gian Paolo; Siebert, Ursula

    2009-07-23

    The presence of tattoo skin disease (TSD) was examined in 1392 free-ranging and dead odontocetes comprising 17 species from the Americas, Europe, South Africa, New Zealand and Greenland. We investigated whether TSD prevalence varied with sex, age and health status. TSD was encountered in cetaceans from the Pacific and Atlantic Oceans as well as in those from the North, Mediterranean and Tasman Seas. No clear patterns related to geography and host phylogeny were detected, except that prevalence of TSD in juveniles and, in 2 species (dusky dolphin Lagenorhynchus obscurus and Burmeister's porpoise Phocoena spinipinnis), in adults was remarkably high in samples from Peru. Environmental factors and virus properties may be responsible for this finding. Sex did not significantly influence TSD prevalence except in the case of Peruvian P. spinipinnis. Generally, there was a pattern of TSD increase in juveniles compared to calves, attributed to the loss of maternal immunity. Also, in most samples, juveniles seemed to have a higher probability of suffering TSD than adults, presumably because more adults had acquired active immunity following infection. This holo-endemic pattern was inverted in poor health short-beaked common dolphins Delphinus delphis and harbour porpoises Phocoena phocoena from the British Isles, and in Chilean dolphins Cephalorhynchus eutropia from Patagonia, where adults showed a higher TSD prevalence than juveniles. Very large tattoos were seen in some adult odontocetes from the SE Pacific, NE Atlantic and Portugal's Sado Estuary, which suggest impaired immune response. The epidemiological pattern of TSD may be an indicator of cetacean population health.

  12. Epidemiology and genetics of common mental disorders in the general population: the PEGASUS-Murcia project

    Science.gov (United States)

    Navarro-Mateu, Fernando; Tormo, MJ; Vilagut, G; Alonso, J; Ruíz-Merino, G; Escámez, T; Salmerón, D; Júdez, J; Martínez, S; Navarro, C

    2013-01-01

    environmental interactions in the aetiology of common mental disorders in representative samples of the general population. A collaborative multidisciplinary research approach offers the potential to advance our knowledge of the underlying complex interactions and this opens the field for further innovative study designs in psychiatric epidemiology. PMID:24302509

  13. Generalized synchronization with uncertain parameters of nonlinear dynamic system via adaptive control.

    Science.gov (United States)

    Yang, Cheng-Hsiung; Wu, Cheng-Lin

    2014-01-01

    An adaptive control scheme is developed to study the generalized adaptive chaos synchronization with uncertain chaotic parameters behavior between two identical chaotic dynamic systems. This generalized adaptive chaos synchronization controller is designed based on Lyapunov stability theory and an analytic expression of the adaptive controller with its update laws of uncertain chaotic parameters is shown. The generalized adaptive synchronization with uncertain parameters between two identical new Lorenz-Stenflo systems is taken as three examples to show the effectiveness of the proposed method. The numerical simulations are shown to verify the results.

  14. Determining Rheological Parameters of Generalized Yield-Power-Law Fluid Model

    Directory of Open Access Journals (Sweden)

    Stryczek Stanislaw

    2004-09-01

    Full Text Available The principles of determining rheological parameters of drilling muds described by a generalized yield-power-law are presented in the paper. Functions between tangent stresses and shear rate are given. The conditions of laboratory measurements of rheological parameters of generalized yield-power-law fluids are described and necessary mathematical relations for rheological model parameters given. With the block diagrams, the methodics of numerical solution of these relations has been presented. Rheological parameters of an exemplary drilling mud have been calculated with the use of this numerical program.

  15. Bridging the data gaps in the epidemiology of hepatitis C virus infection in Malaysia using multi-parameter evidence synthesis.

    Science.gov (United States)

    McDonald, Scott A; Mohamed, Rosmawati; Dahlui, Maznah; Naning, Herlianna; Kamarulzaman, Adeeba

    2014-11-07

    Collecting adequate information on key epidemiological indicators is a prerequisite to informing a public health response to reduce the impact of hepatitis C virus (HCV) infection in Malaysia. Our goal was to overcome the acute data shortage typical of low/middle income countries using statistical modelling to estimate the national HCV prevalence and the distribution over transmission pathways as of the end of 2009. Multi-parameter evidence synthesis methods were applied to combine all available relevant data sources - both direct and indirect - that inform the epidemiological parameters of interest. An estimated 454,000 (95% credible interval [CrI]: 392,000 to 535,000) HCV antibody-positive individuals were living in Malaysia in 2009; this represents 2.5% (95% CrI: 2.2-3.0%) of the population aged 15-64 years. Among males of Malay ethnicity, for 77% (95% CrI: 69-85%) the route of probable transmission was active or a previous history of injecting drugs. The corresponding proportions were smaller for male Chinese and Indian/other ethnic groups (40% and 71%, respectively). The estimated prevalence in females of all ethnicities was 1% (95% CrI: 0.6 to 1.4%); 92% (95% CrI: 88 to 95%) of infections were attributable to non-drug injecting routes of transmission. The prevalent number of persons living with HCV infection in Malaysia is estimated to be very high. Low/middle income countries often lack a comprehensive evidence base; however, evidence synthesis methods can assist in filling the data gaps required for the development of effective policy to address the future public health and economic burden due to HCV.

  16. Epidemiology of Hepatitis E in Pregnant Women and Children in Iran: A General Overview

    Science.gov (United States)

    Taherkhani, Reza; Farshadpour, Fatemeh

    2016-01-01

    Abstract From an epidemiological point of view, hepatitis E is an old infection in Iran, but only recently has its importance as a public health concern been considered from research and public health standpoints. As such, there is still a long road ahead to clarify the real burden of hepatitis E virus (HEV) infection in Iran. According to the available epidemiological studies, the seroprevalence of HEV infection among pregnant women is between 3.6% and 7.4%, and among Iranian children is between 0.9% to 8.5%, varying by geographic regions within the country and directly dependent upon the sanitary status of each. In addition to evaluating the sanitation level of a society, community-based seroprevalence studies of HEV infection demonstrate the most prevalent risk factors, the major routes of transmission, and the epidemiological patterns of HEV among that country’s population. In this review, the current knowledge about the pathogenesis and epidemiology of HEV infection in pregnant women and children in Iran, as well as the recent advances in diagnosis, prevention and treatment of HEV infection have been summarized. PMID:27777896

  17. Bayesian Decision-theoretic Methods for Parameter Ensembles with Application to Epidemiology

    CERN Document Server

    Ginestet, Cedric E

    2011-01-01

    Parameter ensembles or sets of random effects constitute one of the cornerstones of modern statistical practice. This is especially the case in Bayesian hierarchical models, where several decision theoretic frameworks can be deployed. The estimation of these parameter ensembles may substantially vary depending on which inferential goals are prioritised by the modeller. Since one may wish to satisfy a range of desiderata, it is therefore of interest to investigate whether some sets of point estimates can simultaneously meet several inferential objectives. In this thesis, we will be especially concerned with identifying ensembles of point estimates that produce good approximations of (i) the true empirical quantiles and empirical quartile ratio (QR) and (ii) provide an accurate classification of the ensemble's elements above and below a given threshold. For this purpose, we review various decision-theoretic frameworks, which have been proposed in the literature in relation to the optimisation of different aspec...

  18. PARAMETER REGION FOR EXISTENCE OF SOLITONS IN GENERALIZED KdV EQUATION

    Institute of Scientific and Technical Information of China (English)

    ShengPingxing

    2003-01-01

    This paper considers the generalized KdV equation with or without natural boundary conditions and provides a parameter region for solitons and solitary waves,and also modifies a result of Zabusky's.The solitary bifurcation has been discussed.

  19. Admissible Estimators in the General Multivariate Linear Model with Respect to Inequality Restricted Parameter Set

    Directory of Open Access Journals (Sweden)

    Liu Gang

    2009-01-01

    Full Text Available By using the methods of linear algebra and matrix inequality theory, we obtain the characterization of admissible estimators in the general multivariate linear model with respect to inequality restricted parameter set. In the classes of homogeneous and general linear estimators, the necessary and suffcient conditions that the estimators of regression coeffcient function are admissible are established.

  20. A General Approach for Synchronization of Chaotic Systems with Parameters Perturbation

    Institute of Scientific and Technical Information of China (English)

    LONG Min; QIU Shui-Sheng; PENG Fei

    2005-01-01

    By making use of the theory of stability for dynamical systems, a general approach for synchronization of chaotic systems with parameters perturbation is presented, and a general method for determining control function is introduced. The Rossler system is employed to verify the effectiveness of the method, and the theoretical results are confirmed by simulations.

  1. Unknown parameter's variance-covariance propagation and calculation in generalized nonlinear least squares problem

    Institute of Scientific and Technical Information of China (English)

    TAO Hua-xue; GUO Jin-yun

    2005-01-01

    The unknown parameter's variance-covariance propagation and calculation in the generalized nonlinear least squares remain to be studied now,which didn't appear in the internal and external referencing documents. The unknown parameter's variance-covariance propagation formula, considering the two-power terms, was concluded used to evaluate the accuracy of unknown parameter estimators in the generalized nonlinear least squares problem. It is a new variance-covariance formula and opens up a new way to evaluate the accuracy when processing data which have the multi-source,multi-dimensional, multi-type, multi-time-state, different accuracy and nonlinearity.

  2. Generalized projective synchronization of a class of chaotic (hyperchaotic) systems with uncertain parameters

    Institute of Scientific and Technical Information of China (English)

    Jia Zhen; Lu Jun-An; Deng Guang-Ming; Zhang Qun-Jiao

    2007-01-01

    In this paper is investigated the generalized projective synchronization of a class of chaotic (or hyperchaotic) systems, in which certain parameters can be separated from uncertain parameters. Based on the adaptive technique, the globally generalized projective synchronization of two identical chaotic (hyperchaotic) systems is achieved by designing a novel nonlinear controller. Furthermore, the parameter identification is realized simultaneously. A sufficient condition for the globally projective synchronization is obtained. Finally, by taking the hyperchaotic Lü system as example, some numerical simulations are provided to demonstrate the effectiveness and feasibility of the proposed technique.

  3. Robust seismicity forecasting based on Bayesian parameter estimation for epidemiological spatio-temporal aftershock clustering models.

    Science.gov (United States)

    Ebrahimian, Hossein; Jalayer, Fatemeh

    2017-08-29

    In the immediate aftermath of a strong earthquake and in the presence of an ongoing aftershock sequence, scientific advisories in terms of seismicity forecasts play quite a crucial role in emergency decision-making and risk mitigation. Epidemic Type Aftershock Sequence (ETAS) models are frequently used for forecasting the spatio-temporal evolution of seismicity in the short-term. We propose robust forecasting of seismicity based on ETAS model, by exploiting the link between Bayesian inference and Markov Chain Monte Carlo Simulation. The methodology considers the uncertainty not only in the model parameters, conditioned on the available catalogue of events occurred before the forecasting interval, but also the uncertainty in the sequence of events that are going to happen during the forecasting interval. We demonstrate the methodology by retrospective early forecasting of seismicity associated with the 2016 Amatrice seismic sequence activities in central Italy. We provide robust spatio-temporal short-term seismicity forecasts with various time intervals in the first few days elapsed after each of the three main events within the sequence, which can predict the seismicity within plus/minus two standard deviations from the mean estimate within the few hours elapsed after the main event.

  4. Epidemiología de la enfermedad de Chagas, Departamento General Paz, Argentina Chagas' disease epidemiology in the province of General Paz, Argentina

    Directory of Open Access Journals (Sweden)

    Elena B Oscherov

    2003-02-01

    Full Text Available OBJETIVO: El objetivo del presente trabajo fue investigar la colonización por triatominos en ambientes domésticos y peridomésticos y evaluar la seroprevalencia de infectados chagásicos en localidades rurales. MÉTODOS: La investigación se realizó en General Paz, Corrientes, Argentina. Las viviendas y peridomicilios se seleccionaron mediante un muestreo simple al azar. La búsqueda de triatominos se efectuó por el método captura/hora/hombre. Los insectos se identificaron taxonómicamente y se clasificaron según sexo y edad. La infección por Trypanosoma cruzi se detectó por observación directa de las heces al microscopio y por la técnica de la reacción en cadena de la polimerasa (PCR. Se evaluaron serológicamente a pobladores voluntarios mediante las técnicas de hemaglutinación indirecta (HAI y ensayo inmunoenzimático (ELISA. Se hallaron los índices de infestación, densidad, colonización, infección natural y dispersión. RESULTADOS: Se analizaron 42 viviendas y 50 peridomicilios. En el domicilio los índices de infestación e infección de Triatoma infestans fueron 23,8 y 19,4 respectivamente. Los índices de densidad, colonización y dispersión fueron 2,1; 47,0 y 50,0 respectivamente. La infestación del peridomicilio por T. infestans fue 5,9% y por T. sordida 11,8%. T. sordida resultó infectada por Trypanosoma cruzi en un 2,0%. La seroprevalencia al T. cruzi de los 85 pacientes fue del 22,3%. CONCLUSIONES: Se estima que en el área investigada la transmisión del T. cruzi está interrumpida. Sin embargo, la presencia de infectados humanos y de T. infestans parasitadas posibilitan el reinicio del ciclo de transmisión. Se proponen acciones de rociado con insecticidas con el objeto de eliminar las poblaciones del vector.OBJECTIVE: The aim of this study was to evaluate triatomine colonization in domestic and peridomestic ecotopes and to assess the seroprevalence of Chagas' disease in rural areas. METHODS: The study was

  5. Fatty liver and light manual labor: an epidemiological survey in Tianjin by controlled attenuation parameter

    Directory of Open Access Journals (Sweden)

    LI Hai

    2015-07-01

    Full Text Available Objective To investigate the incidence and possible related factors for fatty liver among workers engaged in light manual labor in Tianjin, China. Methods Among 800 healthy workers engaged in light manual labor randomly selected from a company in Tianjin, a total of 602 healthy workers completed physical examination and data collection. The content of fat and liver stiffness were determined by controlled attenuation parameter (CAP using FibroScan, and the disease history, body mass, height, blood pressure, and living habits in all subjects were investigated. The possible related factors for different degrees of fatty liver were analyzed. Between-group comparison of continuous data was performed using the Kruskal-Wallis H test, and comparison of categorical data was performed using χ2 test with row×column tables. Pairwise comparison was performed using χ2 segmentation method, and the agreement between CAP and color ultrasound was analyzed using the Kappa coefficient. Results Among the 602 subjects, there were 180 (29.9%, 195 (32.3%, and 227 (37.7% subjects with severe fatty liver, moderate fatty liver, and no fatty liver, respectively. There were significant differences in age, body mass index, waist-hip ratio, smoking, drinking, history of diabetes, and family history between the above three groups according to CAP (P<0.05 for all. With higher sensitivity, CAP achieved a significantly higher detection rate of fatty liver than traditional color ultrasound (62.3% vs 44.0%, P=0.000. The agreement between two methods was poor (Kappa value <0.4. Conclusion Among the so-called “healthy people” engaged in light manual labor, the incidence of fatty liver has exceeded 60%, which is associated with body mass index, waist-hip ratio, bad living habits, history of diabetes, and family history of fatty liver. CAP can noninvasively detect fatty liver with higher sensitivity and less time; however, its clinical significance needs further studies.

  6. An appraisal of clinicopathological parameters in Japanese encephalitis and changing epidemiological trends in upper Assam, India

    Directory of Open Access Journals (Sweden)

    Saurav Jyoti Patgiri

    2014-01-01

    Full Text Available Context: Japanese encephalitis (JE, an acute mosquito-borne viral disease, is one of the leading causes of viral encephalitis in the South-East Asian region. JE is endemic in Assam. The morbidity and mortality due to JE is significant with outbreaks every year during the monsoons. Aims: The aim was to study the clinicopathological profile of JE; to examine their role in predicting disease outcome; and to document the increase in the incidence of JE among the adult population in this region. Materials and Methods: Clinically suspected acute encephalitis syndrome (AES cases admitted in Assam Medical College and Hospital during the period of May 2011 to April 2012 were tested by JE virus specific Immunoglobulin M capture ELISA. Statistical Analysis Used: Data analysis was performed using SPSS version 16.0. Results: Out of 424 AES cases, 194 were JE positive. The occurrence of JE in adults was higher (P < 0.001 than the pediatric age group. The study recorded a high rate of renal dysfunction in JE cases. A single case of JE induced abortion and two cases of JE-neurocysticercosis co-infections were documented. Regression analysis revealed that adult population, unconsciousness, paresis and elevated cerebrospinal fluid protein level were associated with a worse prognosis in JE cases. Mortality in JE positive cases was higher than the JE negative cases (P = 0.001. Conclusion: The study attempts to highlight the role played by a combination of clinical and laboratory parameters in assessing the severity and outcome in JE and may help in directing the limited medical resources toward those that need it the most.

  7. Molecular epidemiology of hepatitis C infection in Cyprus within the general population and high-risk cohorts

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    Kostrikis Leondios G

    2011-10-01

    Full Text Available Abstract Background Initial data on the molecular epidemiology of HCV infection in Cyprus showed a highly polyphyletic infection and multiple points of introduction into the general population. The continuation and expansion of this investigation is presented here including high risk groups. Findings The samples include additional subjects from the general population, a group of inmates and HIV/HCV coinfected individuals, whose strains were amplified by RT-PCR and sequenced in partial Core-E1 and NS5B regions. The results confirm the broad genotype distribution and polyphyletic infection on the island, and no new subtypes were found. Monophyletic clusters between strains of the prisoners and the injecting drug users imply sharing of infected equipment, and highlight the risk of widespread transmission in these cohorts, although no spill-over to the general population was observed. Conclusions The results of this study underline the impact of population movements and high-risk population groups on the changing molecular epidemiology of HCV, with strains moving to Europe from Asia, Africa and Eastern Europe by means of immigration and modern transmission routes.

  8. Cytological spectrum of salivary gland lesions and their correlation with epidemiological parameters

    Directory of Open Access Journals (Sweden)

    Vaneet Kaur Sandhu

    2017-01-01

    Full Text Available Background: The role fine-needle aspiration (FNA in the diagnosis of salivary gland lesions has evolved over the years. Although clinical and radiological parameters help to narrow the differential diagnosis the tissue diagnosis still remains the gold standard. Materials and Methods: This study is from January 2013 to December 2015 in our Department of Pathology where 170 salivary gland lesions were aspirated. The aim of the present study was to analyze adequacy rate in relation to the size of lesion and to evaluate varied cytological spectrum of salivary gland lesions with emphasis on differential diagnosis and to correlate cytological diagnosis with age, gender and anatomical site. Results: The 170 cytological smears were categorized into two groups: Group 1 adequate aspirations (88.2%, Group 2 inadequate aspirations (11.7%. The adequate aspirations were subdivided as neoplastic (53.33% and nonneoplastic (46.66%. The distribution of the various neoplastic lesions (80; 53.33% were 66 (82.5% benign, 12 (15% were malignant and 2 (2.5% were suspicious of malignancy. Among benign neoplasms, the pleomorphic adenoma (62; 93.3% was the most frequent followed by Warthins tumor (4; 6%. The most common malignant neoplasms were adenoid cystic carcinoma (6; 50%, followed by mucoepidermoid carcinoma (4; 33.3%, malignant lymphoma (1; 8.3% and metastatic carcinomatous deposits (1; 8.3%. In two cases, cytological picture indicated suspicion for malignancy however specific tumor typing could not be done. The neoplasms occurred more frequently in the parotid gland (65%, followed by submandibular gland (21.3% and minor salivary glands (13.8%. The nonneoplastic lesions (70 included 68.6% cases of chronic sialadenitis, 17.1% cases were reported as mucocele, 11.4% cases of acute sialadenitis 2.9% cases as tubercular granulomas. Conclusion: FNA cytology provides useful information on the management of salivary gland lesions and prevents unnecessary surgery in cases

  9. First-order method of zoom lens design by means of generalized parameters.

    Science.gov (United States)

    Khorokhorov, Alexei M; Piskunov, Dmitry E; Shirankov, Alexander F

    2016-08-01

    A method of paraxial zoom lens design is proposed that makes it possible to determine the optical powers and component movements of a zoom lens with the required zoom ratio. The method is based on the theory of generalized parameters, which can be used to analyze a zoom system by varying only one parameter. All possible zoom lenses with two movable components are considered for an object at infinity.

  10. Determination and generalization of the effects of design parameters on Francis turbine runner performance

    Directory of Open Access Journals (Sweden)

    Ece Ayli

    2016-01-01

    Full Text Available The runner design is the most challenging part of the turbine design process. Several parameters determine the performance and cavitation characteristics of the runner: the metal angle (flow beta angle, the alpha angle, the blade beta angle, the runner inlet and outlet diameters, and the blade height. All of these geometrical parameters need to be optimized to ensure that the head, flow rate and power requirements of the system are met. A hydraulic designer has to allocate time to optimize these parameters and should be experienced in carrying out the iterative design process. In this article, the turbine runner parameters that affect the performance and cavitation characteristics of designed turbines are examined in detail. Furthermore, turbines are custom designed according to the properties of hydroelectric power plants; this makes the design process even more challenging, as the rotational speed, runner geometry, system head and flow rate vary for each turbine. The effects of the design parameters are examined for four different turbine runners specifically designed and used in actual power plants in order to obtain general results and generalizations applicable to turbine design aided by computational fluid dynamics (CFD. The flow behavior, flow angles, head losses, pressure distribution, and cavitation characteristics are computed, analyzed, and compared. To assist hydraulic designers, the general influences of these parameters on the performance of turbines are summarized and empirical formulations are derived for runner performance characterization.

  11. Bayesian Statistics and Parameter Constraints on the Generalized Chaplygin Gas Model using SNe Ia Data

    CERN Document Server

    Colistete, R C; Goncalves, S V B

    2004-01-01

    The type Ia supernovae (SNe Ia) observational data are used to estimate the parameters of a cosmological model with cold dark matter and the generalized Chaplygin gas model (GCGM). The GCGM depends essentially on five parameters: the Hubble constant, the parameter $\\bar{A}$ related to the velocity of the sound, the equation of state parameter $\\alpha$, the curvature of the Universe and the fraction density of the generalized Chaplygin gas (or the cold dark matter). The parameter $\\alpha$ is allowed to take negative values and to be greater than 1. The Bayesian parameter estimation yields $\\alpha = - 0.86^{+6.01}_{-0.15}$, $H_0 = 62.0^{+1.32}_{-1.42} km/Mpc.s$, $\\Omega _{k0}=-1.26_{-1.42}^{+1.32}$, $\\Omega_{m0} = 0.00^{+0.86}_{-0.00}$, $\\Omega_{c0} = 1.39^{+1.21}_{-1.25}$, $\\bar A =1.00^{+0.00}_{-0.39}$, $t_0 = 15.3^{+4.2}_{-3.2}$ and $q_0 = -0.80^{+0.86}_{-0.62}$, where $t_0$ is the age of the Universe and $q_0$ is the value of the deceleration parameter today. Our results indicate that a Universe completely ...

  12. Epidemiology of respiratory tract infections in Dutch general practice: a historical analysis.

    NARCIS (Netherlands)

    Schellevis, F.G.; Donker, G.

    2007-01-01

    Aims: To describe time trends in the incidence of respiratory tract infections in general practice in the Netherlands and its relation to sex and age. Design and Methods: Data will be presented from several morbidity surveys conducted in general practices in the Netherlands: the Intermittent Morbidi

  13. Marginal Maximum A Posteriori Item Parameter Estimation for the Generalized Graded Unfolding Model

    Science.gov (United States)

    Roberts, James S.; Thompson, Vanessa M.

    2011-01-01

    A marginal maximum a posteriori (MMAP) procedure was implemented to estimate item parameters in the generalized graded unfolding model (GGUM). Estimates from the MMAP method were compared with those derived from marginal maximum likelihood (MML) and Markov chain Monte Carlo (MCMC) procedures in a recovery simulation that varied sample size,…

  14. Markov Chain Monte Carlo Estimation of Item Parameters for the Generalized Graded Unfolding Model

    Science.gov (United States)

    de la Torre, Jimmy; Stark, Stephen; Chernyshenko, Oleksandr S.

    2006-01-01

    The authors present a Markov Chain Monte Carlo (MCMC) parameter estimation procedure for the generalized graded unfolding model (GGUM) and compare it to the marginal maximum likelihood (MML) approach implemented in the GGUM2000 computer program, using simulated and real personality data. In the simulation study, test length, number of response…

  15. Computer-assisted semen analysis parameters as predictors for fertility of men from the general population

    DEFF Research Database (Denmark)

    Larsen, L; Scheike, Thomas Harder; Jensen, Tina Kold;

    2000-01-01

    The predictive value of sperm motility parameters obtained by computer-assisted semen analysis (CASA) was evaluated for the fertility of men from general population. In a prospective study with couples stopping use of contraception in order to try to conceive, CASA was performed on semen samples...

  16. Constraining Parameters of Generalized Cosmic Chaplygin Gas in Loop Quantum Cosmology

    CERN Document Server

    Ranjit, Chayan

    2014-01-01

    We have assumed the FRW universe in loop quantum cosmology (LQC) model filled with the dark matter and the Generalized Cosmic Chaplygin gas (GCCG) type dark energy where dark matter follows the linear equation of state. We present the Hubble parameter in terms of the observable parameters $\\Omega_{m0}$ and $H_{0}$ with the redshift $z$ and the other parameters like $A$, $B$, $w_{m}$, $ \\omega$ and $\\alpha$ which coming from our model. From Stern data set (12 points)\\& SNe Type Ia 292 data (from \\cite{Riess1,Riess2,Astier}) we have obtained the bounds of the arbitrary parameters by minimizing the $\\chi^{2}$ test. The best-fit values of the parameters are obtained by 66\\%, 90\\% and 99\\% confidence levels. Next due to joint analysis with Stern+BAO and Stern+BAO+CMB observations, we have also obtained the bounds of the parameters ($A,B$) by fixing some other parameters $\\alpha$, $w_{m}$ and $\\omega$. From the best fit values of the parameters, we have obtained the distance modulus $\\mu(z)$ for our theoretical...

  17. Eating disorders behaviours and diagnoses: epidemiology and comorbidity in the general population

    OpenAIRE

    Solmi, F.

    2014-01-01

    Introduction: Studies investigating prevalence and comorbidity of eating disorders (ED) and disordered eating in large general population samples are limited. This thesis adds to the existing literature by employing general population studies to investigate prevalence and comorbidity of disordered eating and ED in adults and adolescents. Secondary aims were to explore occurrence of ED in relation to ethnicity and patterns of service use. Methods: The studies included in this thesis employed t...

  18. Post-Newtonian parameter γ in generalized non-local gravity

    Science.gov (United States)

    Zhang, Xue; Wu, YaBo; Yang, WeiQiang; Zhang, ChengYuan; Chen, BoHai; Zhang, Nan

    2017-10-01

    We investigate the post-Newtonian parameter γ and derive its formalism in generalized non-local (GNL) gravity, which is the modified theory of general relativity (GR) obtained by adding a term m 2 n-2 R☐-n R to the Einstein-Hilbert action. Concretely, based on parametrizing the generalized non-local action in which gravity is described by a series of dynamical scalar fields ϕ i in addition to the metric tensor g μν, the post-Newtonian limit is computed, and the effective gravitational constant as well as the post-Newtonian parameters are directly obtained from the generalized non-local gravity. Moreover, by discussing the values of the parametrized post-Newtonian parameters γ, we can compare our expressions and results with those in Hohmann and Järv et al. (2016), as well as current observational constraints on the values of γ in Will (2006). Hence, we draw restrictions on the nonminimal coupling terms F̅ around their background values.

  19. Optimization of the dressing parameters in cylindrical grinding based on a generalized utility function

    Science.gov (United States)

    Aleksandrova, Irina

    2016-01-01

    The existing studies, concerning the dressing process, focus on the major influence of the dressing conditions on the grinding response variables. However, the choice of the dressing conditions is often made, based on the experience of the qualified staff or using data from reference books. The optimal dressing parameters, which are only valid for the particular methods and dressing and grinding conditions, are also used. The paper presents a methodology for optimization of the dressing parameters in cylindrical grinding. The generalized utility function has been chosen as an optimization parameter. It is a complex indicator determining the economic, dynamic and manufacturing characteristics of the grinding process. The developed methodology is implemented for the dressing of aluminium oxide grinding wheels by using experimental diamond roller dressers with different grit sizes made of medium- and high-strength synthetic diamonds type ??32 and ??80. To solve the optimization problem, a model of the generalized utility function is created which reflects the complex impact of dressing parameters. The model is built based on the results from the conducted complex study and modeling of the grinding wheel lifetime, cutting ability, production rate and cutting forces during grinding. They are closely related to the dressing conditions (dressing speed ratio, radial in-feed of the diamond roller dresser and dress-out time), the diamond roller dresser grit size/grinding wheel grit size ratio, the type of synthetic diamonds and the direction of dressing. Some dressing parameters are determined for which the generalized utility function has a maximum and which guarantee an optimum combination of the following: the lifetime and cutting ability of the abrasive wheels, the tangential cutting force magnitude and the production rate of the grinding process. The results obtained prove the possibility of control and optimization of grinding by selecting particular dressing

  20. The epidemiology of contact allergy in the general population--prevalence and main findings

    DEFF Research Database (Denmark)

    Thyssen, Jacob Pontoppidan; Linneberg, Allan; Menné, Torkil

    2007-01-01

    1966 and 2007. The most prevalent contact allergens were nickel, thimerosal, and fragrance mix. The median nickel allergy prevalence was 8.6% (range 0.7-27.8%) and demonstrates that nickel was an important cause of contact allergy in the general population and that it was widespread in both men...

  1. Sensitivity of a general circulation model to land surface parameters in African tropical deforestation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Maynard, K.; Royer, J.F. [Meteo-France CNRM, 42 Avenue G. Coriolis, 31057, Toulouse Cedex 1 (France)

    2004-06-01

    During the last two decades, several land surface schemes for use in climate, regional and/or mesoscale, hydrological and ecological models have been designed. Incorrect parametrization of land-surface processes and prescription of the surface parameters in atmospheric modeling, can result in artificial changes of the horizontal gradient of the sensible heat flux. Thus, an error in horizontal temperature gradient within the lower atmosphere may be introduced. The reliability of the model depends on the quality of boundary layer scheme implemented and its sensitivity to the bare soil and vegetation parameters. In this study, a series of sensitivity experiments has been conducted over broad time scales, using a version of the ARPEGE Climate Model coupled to the ISBA land surface scheme in order to investigate model sensitivity to separate changes in land surface parameters over Africa. Effects of perturbing vegetation cover, distribution of soil depth, albedo of vegetation, roughness length, leaf area index and minimum stomatal resistance were explored by using a simple statistical analysis. Identifying which parameters are important in controlling turbulent energy fluxes, temperature and soil moisture is dependent on which variables are used to determine sensibility, which type of vegetation and climate regime is being simulated and the magnitude and sign of the parameter change. This study does not argue that a particular parameter is important in ISBA, rather it shows that no general ranking of parameters is possible. So, it is essential to specify all land surface parameters with greater precision when attempting to determine the climate response to modification of the land surface. The implication of ISBA being sensitive to parameters that cannot be validated suggests that there will always be considerable doubt over the predictive quality of land-surface schemes. (orig.)

  2. Epidemiology of unintentional injuries in childhood: a population-based survey in general practice

    Science.gov (United States)

    Otters, Hanneke; Schellevis, François G; Damen, Jurgen; van der Wouden, Johannes C; van Suijlekom-Smit, Lisette W A; Koes, Bart W

    2005-01-01

    This study aimed to assess the incidence of unintentional injuries presented in general practice, and to identify children at risk from experiencing an unintentional injury. We used the data of all 0–17-year-old children from a representative survey in 96 Dutch general practices in 2001. We computed incidence rates and multilevel multivariate regression analysis in different age strata and identified patient and family characteristics associated with an elevated injury risk. Nine thousand four hundred and eighty-four new injury episodes were identified from 105 353 new health problems presented in general practice, giving an overall incidence rate of 115 per 1000 person years (95% confidence interval [CI] = 113 to 118). Sex and residence in rural areas are strong predictors of injury in all age strata. Also, in children aged 0–4 years, a higher number of siblings is associated with elevated injury risk (≥3 siblings odds ratio [OR] = 1.57, 95% CI = 1.19 to 2.08) and in the 12–17-year-olds, ethnic background and socioeconomic class are associated with experiencing an injury (non-western children OR = 0.67, 95% CI = 0.54 to 0.81; low socioeconomic class OR = 1.39, 95% CI = 1.22 to 1.58). Unintentional injury is a significant health problem in children in general practice, accounting for 9% of all new health problems in children. In all age groups, boys in rural areas are especially at risk to experience an injury. PMID:16105373

  3. The Epidemiology of Major Depressive Episode in the Iraqi General Population.

    Directory of Open Access Journals (Sweden)

    Ali Obaid Al-Hamzawi

    Full Text Available To assess the prevalence, symptom severity, functional impairment, and treatment of major depressive episode (MDE in the Iraqi general population.The Iraq Mental Health Survey is a nationally representative face-to-face survey of 4,332 non-institutionalized adults aged 18+ interviewed in 2006-2007 as part of the WHO World Mental Health Surveys. Prevalence and correlates of DSM-IV MDE were determined with the WHO Composite International Diagnostic Interview (CIDI.Lifetime and 12-month prevalence of MDE were 7.4% and 4.0%, respectively. Close to half (46% of the 12-month MDE cases were severe/very severe. MDE was more common among women and those previously married. Median age of onset was 25.2. Only one-seventh of 12-month MDE cases received treatment despite being associated with very substantial role impairment (on average 70 days out of role in the past year.MDE is a commonly occurring disorder in the Iraqi general population and is associated with considerable disability and low treatment. Efforts are needed to decrease the barriers to treatment and to educate general medical providers in Iraq about the recognition and treatment of depression.

  4. Evolution of the Brans-Dicke Parameter in Generalized Chameleon Cosmology

    Institute of Scientific and Technical Information of China (English)

    Mubasher Jami; D.Momeni

    2011-01-01

    @@ Motivated by an earlier study of Sahoo and Singh[Mod.Phys.Lett.A 17(2002)2409],we investigate the time dependence of the Brans-Dicke parameter ω(t)for an expanding Universe in the generalized Brans-Dicke Chameleon cosmology,and obtain an explicit dependence of ω(t)in different expansion phases of the Universe.Also,we discuss how the observed accelerated expansion of the observable Universe can be accommodated in the present formalism.%Motivated by an earlier study of Sahoo and Singh [Mod. Phys. Lett. A 17(2002)2409], we investigate the time dependence of the Brans-Dicke parameter ui(t) for an expanding Universe in the generalized Brans-Dicke Chameleon cosmology, and obtain an explicit dependence of uj(t) in different expansion phases of the Universe. Also, we discuss how the observed accelerated expansion of the observable Universe can be accommodated in the present formalism.

  5. A survey of French general practitioners on the epidemiology of wounds in family practice

    Directory of Open Access Journals (Sweden)

    Sarazin M

    2015-06-01

    Full Text Available Marianne Sarazin,1–3 Florence Roberton,4 Rodolphe Charles,4 Alessandra Falchi,1,2,5 Solange Gonzales Chiappe,1–3 Thierry Blanchon,1,2 Frédéric Lucht,6 Thomas Hanslik1,2,7,8 1INSERM, UMR_S 1136, F-75012, Paris, France; 2Sorbonne Universités, UPMC University Paris 06, UMR_S 1136, F-75012, Paris, France; 3DIM, Centre Hospitalier, 42 700 Firminy, France; 4Département de médecine générale, Faculté de médecine Jacques Lisfranc, F-42023 Saint Etienne, CE France; 5EA 7310, Laboratoire de Virologie, Université de Corse, F-20250 Corte, France; 6CIC-EC3, CHU Saint Etienne, F-42277 Saint-Priest en Jarez, CE France; 7UVSQ, Université de Versailles Saint Quentin, F-78000 Versailles, France; 8Assistance Publique Hôpitaux de Paris, service de Médecine Interne, Hôpital Ambroise Paré, F-92100 Boulogne Billancourt, France Background: To measure the frequency and nature of wounds in patients treated in general practice and to describe the patients' tetanus vaccination status and the sources providing information about this status. Methods: A descriptive, prospective, week-long, national electronic survey was conducted among general practitioners within the Sentinelles network. Results: The participation rate was 12.6% (95% confidence interval [CI], 10.6%–14.6%; 130 general practitioners: 197 patients with wounds were reported, and 175 of them were described. Wound frequency was 1.4 (95% CI, 1.2–1.6 per 100 consultations. These wounds had an acute character in 76 (95% CI, 69.7–82.3 of cases, were mostly of traumatic origin (54.8% of cases; 95% CI, 47.5%–62.1%, were more than 24 hours old (67.1%; 95% CI, 59.1%–75.1%, and were clean, without bone and/or muscle decay (94%; 95% CI, 90.5%–97.5%. Vaccination status was known for 71 (95% CI, 64–78 patients. According to the 2013 immunization schedule, 21% (95% CI, 13.9%–28.1% of the patients had not updated their vaccinations, mostly among the patients older than 75 years. Conclusion

  6. Descriptive epidemiology of stigma against depression in a general population sample in Alberta

    Directory of Open Access Journals (Sweden)

    Wang JianLi

    2010-04-01

    Full Text Available Abstract Background Mental health illnesses, such as depression, are responsible for a growing disease burden worldwide. Unfortunately, effective treatment is often impeded by stigmatizing attitudes of other individuals, which have been found to lead to a number of negative consequences including reduced help-seeking behavior and increased social distance. Despite the high prevalence of depression in Canada, little research has been conducted to examine stigma against depression in the Canadian general population. Such information is crucial to understanding the current state of stigmatizing attitudes in the Canadian communities, and framing future stigma reduction initiatives. The objectives of this study were to estimate the percentages of various stigmatizing attitudes toward depression in a general population sample and to compare the percentages by demographics and socioeconomic characteristics. Methods We conducted a cross-sectional telephone survey in Alberta, Canada, between February and June 2006. Random digit dialing was used to recruit participants who were aged 18-74 years old (n = 3047. Participants were presented a case vignette describing a depressed individual, and responded to a 9-item Personal Stigma questionnaire. The percentages of stigmatizing attitudes were estimated and compared by demographic and socioeconomic variables. Results Among the participants, 45.9% endorsed that depressed individuals were unpredictable and 21.9% held the view that people with depression were dangerous. Significant differences in stigmatizing attitudes were found by gender, age, education, and immigration status. A greater proportion of men than women held stigmatizing views on each stigma item. No consistent trend emerged by age in stigma against depression. Participants with higher levels of education reported less stigmatizing attitudes than those with less education. Participants who were not born in Canada were more likely to hold

  7. [Etiology and epidemiology of 547 episodes of acute viral hepatitis diagnosed in adults in a general hospital (1983-1994)].

    Science.gov (United States)

    Rodriguez, M; Martinez, A; Sala, P; Pérez, R; Linares, A; Sánchez-Lombraña, J L; Rodrigo, L

    1996-01-01

    The etiology and epidemiology of 547 consecutive episodes of acute viral hepatitis in adults and diagnosed in a general hospital over 12 years (1983-1994) were prospectively analyzed as were the changes observed during the two halves of the study period. Of the 547 episodes, 25.4% were of type A, 41.1% type B, 21.9% type C, 6.6% non A, non B, non C, 2.4% type D, 1.1% by cytomegalovirus and 1.4% by the Epstein-Barr virus. The proportion of hepatitis A increased from 21.5% from 1983-1988 to 34.1% from 1989-1994 (p = 0.002), while hepatitis C decreased from 24.9% to 15.3% (p = 0.01) during the same periods. The proportion of hepatitis B observed in intravenous drug addicts fell from 56.1% in the first period to 39.3% in the second period (p = 0.03), while sexually transmitted hepatitis B rose from 7.3% to 22.9% (p = 0.002). A decrease was observed in the cases of hepatitis C in both periods in the intravenous drug addict cases (60.6% vs. 34.6%; p = 0.03) with an increase being observed in the C virus transmitted by unapparent mechanisms (2.1% vs. 23.1%; p = 0.001). These results suggest that modifications may currently be observed in the epidemiology of the viral hepatitis in Spain and that these trends should be taken into account when planning preventive strategies.

  8. Post-Newtonian parameter $\\gamma$ for multiscalar-tensor gravity with a general potential

    CERN Document Server

    Hohmann, Manuel; Kuusk, Piret; Randla, Erik; Vilson, Ott

    2016-01-01

    We compute the parametrized post-Newtonian parameter $\\gamma$ in the case of a static point source for multiscalar-tensor gravity with completely general nonderivative couplings and potential in the Jordan frame. Similarly to the single massive field case $\\gamma$ depends exponentially on the distance from the source and is determined by the length of a vector of non-minimal coupling in the space of scalar fields and its orientation relative to the mass eigenvectors. Using data from the Cassini tracking experiment, we estimate bounds on a general theory with two scalar fields. Our formalism can be utilized for a wide range of models, which we illustrate by applying it to nonminimally coupled Higgs SU(2) doublet, general hybrid metric-Palatini gravity, linear ($\\Box^{-1}$) and quadratic ($\\Box^{-2}$) nonlocal gravity.

  9. A community-based epidemiological study of health anxiety and generalized anxiety disorder.

    Science.gov (United States)

    Lee, Sing; Lam, Ivy M H; Kwok, Kathleen P S; Leung, Candi M C

    2014-03-01

    This community-based study examined the frequency of worry about personal health in respondents with and without generalized anxiety disorder (GAD), and the impact of health anxiety on the disorder. A random community-based telephone survey of 5118 Chinese respondents aged 18-64 was conducted. A fully structured questionnaire covered the DSM-IV-TR criteria of GAD, major depressive episode (MDE), eight domains of worry, the seven-item Whiteley Index (WI-7), health service use, and socio-demographic information. Worry about personal health ranked fifth (75.6%) among eight domains of worries examined. GAD respondents with high level of health anxiety were significantly older, less educated, and had lower family income. High health anxiety significantly increased the occurrence of one-year MDE, previous persistent worry, previous persistent low mood, number of domains of worries, number of non-core DSM-IV-TR GAD symptoms, health service use, and mistrust of doctors. Health anxiety is common in GAD and may signify greater severity of the disorder. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. INTRA-ABDOMINAL INFECTION AND ACUTE ABDOMEN-EPIDEMIOLOGY, DIAGNOSIS AND GENERAL PRINCIPLES OF SURGICAL MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Jovanović Dušan

    2015-03-01

    Full Text Available Intra-abdominal infections are multifactorial and present an complex inflammatory response of the peritoneum to microorganisms followed by exudation in the abdominal cavity and systemic response Despite advances in management and critical care of patients with acute generalized peritonitis due to hollow viscus perforation, prognosis is still very poor, with high mortality rate. Early detection and adequate treatment is essential to minimize complications in the patient with acute abdomen. Prognostic evaluation of complicated IAI by modern scoring systems is important to assess the severity and the prognosis of the disease. Control of the septic source can be achieved either by nonoperative or operative means. Nonoperative interventional procedures include percutaneous drainages of abscesses. The management of primary peritonitis is non-surgical and antibiotic- treatment. The management of secondary peritonitis include surgery to control the source of infection, removal of toxins, bacteria, and necrotic tissue, antibiotic therapy, supportive therapy and nutrition. "Source control" is sine qua non of success and adequate surgical procedure involves closure or resection of any openings into the gastrointestinal tract, resection of inflamed tissue and drainage of all abdominal and pelivic collections.

  11. Rosacea: current state of epidemiology.

    Science.gov (United States)

    Tan, Jerry; Berg, Mats

    2013-12-01

    Case definitions are critical in epidemiologic research. However, modern disease indicators must now consider complex data from gene-based research along with traditional clinical parameters. Rosacea is a skin disorder with multiple signs and symptoms. In individuals, these features may be multiple or one may predominate. While studies on the epidemiology of rosacea have previously been sparse, there has been a recent increase in research activity. A broader body of epidemiological information that includes a greater variety of countries beyond Northern Europe and general population-based demographics is needed. As there are operational issues in current case definitions of rosacea subtypes--rationalization and standardization--universal consistent applications in future research is also imperative. Further improvement in disease definition combining new research information along with clinical pragmatism should increase the accuracy of rosacea case ascertainment and facilitate further epidemiological research.

  12. CONSTANCES: a general prospective population-based cohort for occupational and environmental epidemiology: cohort profile

    Science.gov (United States)

    Goldberg, Marcel; Carton, Matthieu; Descatha, Alexis; Leclerc, Annette; Roquelaure, Yves; Santin, Gaëlle; Zins, Marie

    2017-01-01

    Why the cohort was set up? CONSTANCES is a general-purpose cohort with a focus on occupational and environmental factors. Cohort participants CONSTANCES was designed as a randomly selected sample of French adults aged 18–69 years at inception; 200 000 participants will be included. Data collection phases At enrolment, the participants are invited to complete questionnaires and to attend a health screening centre (HSC) for a health examination. A biobank will be set up. The follow-up includes an yearly self-administered questionnaire, a periodic visit to an HSC and linkage to social and national health administrative databases. Main types of data collected Data collected for participants include social and demographic characteristics, socioeconomic status, life events and behaviours. Regarding occupational and environmental factors, a wealth of data on organisational, chemical, biological, biomechanical and psychosocial lifelong exposure, as well as residential characteristics, are collected at enrolment and during follow-up. The health data cover a wide spectrum: self-reported health scales, reported prevalent and incident diseases, long-term chronic diseases and hospitalisations, sick-leaves, handicaps, limitations, disabilities and injuries, healthcare usage and services provided, and causes of death. Control of selection effects To take into account non-participation and attrition, a random cohort of non-participants was set up and will be followed through the same national databases as participants. Data access Inclusions begun at the end of 2012 and more than 110 000 participants were already included by September 2016. Several projects on occupational and environmental risks already applied to a public call for nested research projects. PMID:27884936

  13. Design and Feasibility of an International Study Assessing the Prevalence of Contact Allergy to Fragrances in the General Population : The European Dermato-Epidemiology Network Fragrance Study

    NARCIS (Netherlands)

    Rossi, Marta; Coenraads, Pieter-Jan; Diepgen, Thomas; Svensson, Ake; Elsner, Peter; Goncalo, Margarida; Bruze, Magnus; Naldi, Luigi

    2010-01-01

    Background/Aims: Data on contact allergy to fragrances in the general population are limited. Data from allergological services suggest that the frequency of contact allergy to fragrances is increasing. The European Dermato-Epidemiology Network (EDEN) Fragrance Study aims to obtain reliable data on

  14. Epidemiología de la enfermedad de Chagas, Departamento General Paz, Argentina

    Directory of Open Access Journals (Sweden)

    Oscherov Elena B

    2003-01-01

    Full Text Available OBJETIVO: El objetivo del presente trabajo fue investigar la colonización por triatominos en ambientes domésticos y peridomésticos y evaluar la seroprevalencia de infectados chagásicos en localidades rurales. MÉTODOS: La investigación se realizó en General Paz, Corrientes, Argentina. Las viviendas y peridomicilios se seleccionaron mediante un muestreo simple al azar. La búsqueda de triatominos se efectuó por el método captura/hora/hombre. Los insectos se identificaron taxonómicamente y se clasificaron según sexo y edad. La infección por Trypanosoma cruzi se detectó por observación directa de las heces al microscopio y por la técnica de la reacción en cadena de la polimerasa (PCR. Se evaluaron serológicamente a pobladores voluntarios mediante las técnicas de hemaglutinación indirecta (HAI y ensayo inmunoenzimático (ELISA. Se hallaron los índices de infestación, densidad, colonización, infección natural y dispersión. RESULTADOS: Se analizaron 42 viviendas y 50 peridomicilios. En el domicilio los índices de infestación e infección de Triatoma infestans fueron 23,8 y 19,4 respectivamente. Los índices de densidad, colonización y dispersión fueron 2,1; 47,0 y 50,0 respectivamente. La infestación del peridomicilio por T. infestans fue 5,9% y por T. sordida 11,8%. T. sordida resultó infectada por Trypanosoma cruzi en un 2,0%. La seroprevalencia al T. cruzi de los 85 pacientes fue del 22,3%. CONCLUSIONES: Se estima que en el área investigada la transmisión del T. cruzi está interrumpida. Sin embargo, la presencia de infectados humanos y de T. infestans parasitadas posibilitan el reinicio del ciclo de transmisión. Se proponen acciones de rociado con insecticidas con el objeto de eliminar las poblaciones del vector.

  15. Synthetic Weyl points in generalized parameter space and their topological properties

    CERN Document Server

    Wang, Qiang; Liu, Hui; Wan, Xiangang; Zhu, Shining; Chan, C T

    2016-01-01

    Weyl fermions1 do not appear in nature as elementary particles, but they are now found to exist as nodal points in the band structure of electronic and classical wave crystals. Novel phenomena such as Fermi arcs and chiral anomaly have fueled the interest of these topological points which are frequently perceived as monopoles in momentum space. Here, we demonstrate that generalized Weyl points can exist in a parameter space and we report the first observation of such nodal points in one-dimensional photonic crystals in the optical range. The reflection phase inside the band gap of a truncated photonic crystal exhibits vortexes in the parameter space where the Weyl points are defined and they share the same topological charges as the Weyl points. These vortexes guarantee the existence of interface states, the trajectory of which can be understood as "Fermi arcs" emerging from the Weyl nodes.

  16. General RG Equations for Physical Neutrino Parameters and their Phenomenological Implications

    CERN Document Server

    Casas, J A; Ibarra, Alejandro; Navarro, I

    2000-01-01

    The neutral leptonic sector of the Standard Model presumably consists of three neutrinos with non-zero Majorana masses with properties further determined by three mixing angles and three CP-violating phases. We derive the general renormalization group equations for these physical parameters and apply them to study the impact of radiative effects on neutrino physics. In particular, we examine the existing solutions to the solar and atmospheric neutrino problems, derive conclusions on their theoretical naturalness, and show how some of the measured neutrino parameters could be determined by purely radiative effects. For example, the mass splitting and mixing angle suggested by solar neutrino data could be entirely explained as a radiative effect if the small angle MSW solution is realized. On the other hand, the mass splitting required by atmospheric neutrino data is probably determined by unknown physics at a high energy scale. We also discuss the effect of non-zero CP-violating phases on radiative corrections...

  17. A New Insight into the Earthquake Recurrence Studies from the Three-parameter Generalized Exponential Distributions

    Science.gov (United States)

    Pasari, S.; Kundu, D.; Dikshit, O.

    2012-12-01

    Earthquake recurrence interval is one of the important ingredients towards probabilistic seismic hazard assessment (PSHA) for any location. Exponential, gamma, Weibull and lognormal distributions are quite established probability models in this recurrence interval estimation. However, they have certain shortcomings too. Thus, it is imperative to search for some alternative sophisticated distributions. In this paper, we introduce a three-parameter (location, scale and shape) exponentiated exponential distribution and investigate the scope of this distribution as an alternative of the afore-mentioned distributions in earthquake recurrence studies. This distribution is a particular member of the exponentiated Weibull distribution. Despite of its complicated form, it is widely accepted in medical and biological applications. Furthermore, it shares many physical properties with gamma and Weibull family. Unlike gamma distribution, the hazard function of generalized exponential distribution can be easily computed even if the shape parameter is not an integer. To contemplate the plausibility of this model, a complete and homogeneous earthquake catalogue of 20 events (M ≥ 7.0) spanning for the period 1846 to 1995 from North-East Himalayan region (20-32 deg N and 87-100 deg E) has been used. The model parameters are estimated using maximum likelihood estimator (MLE) and method of moment estimator (MOME). No geological or geophysical evidences have been considered in this calculation. The estimated conditional probability reaches quite high after about a decade for an elapsed time of 17 years (i.e. 2012). Moreover, this study shows that the generalized exponential distribution fits the above data events more closely compared to the conventional models and hence it is tentatively concluded that generalized exponential distribution can be effectively considered in earthquake recurrence studies.

  18. Generalized two-mode coherent-entangled state with real parameters

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The coherent-entangled state |α, x; λ> with real parameters λ is proposed in the two-mode Fock space, which exhibits the properties of both the coherent and entangled states. The completeness relation of |α, x; λ> is proved by virtue of the technique of integral within an ordered product of operators. The corresponding squeezing operator is derived, with its own squeezing properties. Furthermore, generalized P-representation in the coherent-entangled state is constructed. Finally, it is revealed that superposition of the coherent-entangled states may produce the EPR entangled state.

  19. Different parameters support generalization and discrimination learning in Drosophila at the flight simulator.

    Science.gov (United States)

    Brembs, Björn; Hempel de Ibarra, Natalie

    2006-01-01

    We have used a genetically tractable model system, the fruit fly Drosophila melanogaster to study the interdependence between sensory processing and associative processing on learning performance. We investigated the influence of variations in the physical and predictive properties of color stimuli in several different operant-conditioning procedures on the subsequent learning performance. These procedures included context and stimulus generalization as well as color, compound, and conditional discrimination (colors and patterns). A surprisingly complex dependence of the learning performance on the colors' physical and predictive properties emerged, which was clarified by taking into account the fly-subjective perception of the color stimuli. Based on estimates of the stimuli's color and brightness values, we propose that the different tasks are supported by different parameters of the color stimuli; generalization occurs only if the chromaticity is sufficiently similar, whereas discrimination learning relies on brightness differences.

  20. Epidemiologic profile of otorhinolaryngological, head and neck disorders in a tertiary hospital unit in Greece: a challenge for general practitioners?

    Directory of Open Access Journals (Sweden)

    Rachiotis Georgios

    2006-06-01

    Full Text Available Abstract Background In Greece, primary care is still developing. The aim of this study was to define the epidemiologic profile of common otorhinolaryngological, head and neck disorders in order to help general practitioners to deal with them in a primary care future. Methods A total of 6771 patients attended the Otorhinolaryngology emergency department of the University General Hospital of Heraklion (Crete, between January and December 2004. All cases were included in this retrospective study. The registry of the Otorhinolaryngology emergency department was analysed and age, sex, seasonality and clinical diagnosis were tabulated. All patients were evaluated by Otorhinolaryngologists. The classification of the cases was based on the main symptom or clinical sign that conditioned the reason for seeking care. Diagnoses were also coded according to the International Classification of Diseases (ICD-10. Results The male to female ratio was 1:1. The mean age for females was 36.3 years standard deviation (SD: 21.1 and for males was 36.8 years (SD = 22.0. Eight hundred eighty six patients (13.1% formed the paediatric sub-group. Over 60% of the cases were classified in ten major groups of diagnosis. Acute tonsillitis (12.3% and acute pharyngitis (9.0% were the most common causes of all medical visits, followed by otitis media (7.6% and external ear canal obstruction by ear wax (6.2%. Oedema of the larynx was detected in 0.4%. A negative diagnosis of otorhinolaryngological, head and neck disorder was formulated in 553 patients (8.2%. Hospitalization rate was 5.2%. The highest rate of visits was registered in March. Conclusion Most patients used the facility as a primary care service. Real emergencies were a minority. Recovering data about which areas of Otorhinolaryngology deserve more emphasis might help primary health care providers to diagnose and manage the common otorhinolaryngological, head and neck disorders properly.

  1. A general method for parameter estimation in light-response models.

    Science.gov (United States)

    Chen, Lei; Li, Zhong-Bin; Hui, Cang; Cheng, Xiaofei; Li, Bai-Lian; Shi, Pei-Jian

    2016-06-13

    Selecting appropriate initial values is critical for parameter estimation in nonlinear photosynthetic light response models. Failed convergence often occurs due to wrongly selected initial values when using currently available methods, especially the kind of local optimization. There are no reliable methods that can resolve the conundrum of selecting appropriate initial values. After comparing the performance of the Levenberg-Marquardt algorithm and other three algorithms for global optimization, we develop a general method for parameter estimation in four photosynthetic light response models, based on the use of Differential Evolution (DE). The new method was shown to successfully provide good fits (R(2) > 0.98) and robust parameter estimates for 42 datasets collected for 21 plant species under the same initial values. It suggests that the DE algorithm can efficiently resolve the issue of hyper initial-value sensitivity when using local optimization methods. Therefore, the DE method can be applied to fit the light-response curves of various species without considering the initial values.

  2. A general method for parameter estimation in light-response models

    Science.gov (United States)

    Chen, Lei; Li, Zhong-Bin; Hui, Cang; Cheng, Xiaofei; Li, Bai-Lian; Shi, Pei-Jian

    2016-06-01

    Selecting appropriate initial values is critical for parameter estimation in nonlinear photosynthetic light response models. Failed convergence often occurs due to wrongly selected initial values when using currently available methods, especially the kind of local optimization. There are no reliable methods that can resolve the conundrum of selecting appropriate initial values. After comparing the performance of the Levenberg–Marquardt algorithm and other three algorithms for global optimization, we develop a general method for parameter estimation in four photosynthetic light response models, based on the use of Differential Evolution (DE). The new method was shown to successfully provide good fits (R2 > 0.98) and robust parameter estimates for 42 datasets collected for 21 plant species under the same initial values. It suggests that the DE algorithm can efficiently resolve the issue of hyper initial-value sensitivity when using local optimization methods. Therefore, the DE method can be applied to fit the light-response curves of various species without considering the initial values.

  3. Prediction of the effective parameters of the nanofluids using the generalized stochastic perturbation method

    Science.gov (United States)

    Kamiński, Marcin; Ossowski, Rafał Leszek

    2014-01-01

    The paper presents the results concerning a new problem of homogenization of the fluids filled with a random volume fraction of nanoparticles. We use a variety of probabilistic and statistical methods applied for numerical determination of the effective physical properties of different fluids filled with nanoparticles. The new probabilistic approach in the form of a higher order stochastic perturbation method is employed here, which is based on a higher order Taylor expansion of input random quantities and the resulting homogenized parameters using a general order series with random coefficients; it is contrasted with the Monte Carlo simulation and analytical symbolic integration. All computer methods are used to determine up to the fourth probabilistic moments and coefficients for effective specific heat, viscosity, heat conductivity and mass density for some nanofluids of modern technological importance. The volume fraction of the nanoparticles is treated in this study as the input Gaussian parameter truncated to the positive values and uniquely defined by the expectation, where its coefficient of variation is an additional parameter in our analysis. Computational experiments are performed here using computer algebra system MAPLE and they demonstrate a very good agreement of the probabilistic characteristics computed using analytical, perturbation and simulation methods.

  4. On the Generalization Capabilities of the Ten-Parameter Jiles-Atherton Model

    Directory of Open Access Journals (Sweden)

    Gabriele Maria Lozito

    2015-01-01

    Full Text Available This work proposes an analysis on the generalization capabilities for the modified version of the classic Jiles-Atherton model for magnetic hysteresis. The modified model takes into account the use of dynamic parameterization, as opposed to the classic model where the parameters are constant. Two different dynamic parameterizations are taken into account: a dependence on the excitation and a dependence on the response. The identification process is performed by using a novel nonlinear optimization technique called Continuous Flock-of-Starling Optimization Cube (CFSO3, an algorithm belonging to the class of swarm intelligence. The algorithm exploits parallel architecture and uses a supervised strategy to alternate between exploration and exploitation capabilities. Comparisons between the obtained results are presented at the end of the paper.

  5. Parameter estimation in the presence of the most general Gaussian dissipative reservoir

    Science.gov (United States)

    Jarzyna, Marcin; Zwierz, Marcin

    2017-01-01

    We analyze the performance of quantum parameter estimation in the presence of the most general Gaussian dissipative reservoir. We derive lower bounds on the precision of phase estimation and a closely related problem of frequency estimation. For both problems we show that it is impossible to achieve the Heisenberg limit asymptotically in the presence of such a reservoir. However, we also find that for any fixed number of probes used in the setup there exists a Gaussian dissipative reservoir, which, in principle, allows for the Heisenberg-limited performance for that number of probes. We discuss a realistic implementation of a frequency estimation scheme in the presence of a Gaussian dissipative reservoir in a cavity system.

  6. Chemically induced transition phenomena in polyurethanes as seen from generalized mode Grueneisen parameters

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, U; Philipp, M; Bactavatchalou, R; Sanctuary, R; Baller, J; Zielinski, B; Krueger, J K [Laboratoire de Physique des Materiaux, Universite du Luxembourg, 162A, Avenue de la Faiencerie, L-1115 (Luxembourg); Possart, W; Alnot, P [Laboratoire Europeen de Recherche, Universitaire Saarland-Lorraine (Luxembourg)], E-mail: ulrich.mueller@uni.lu

    2008-05-21

    Many phenomenological properties of reactive polymers like polyurethanes increase or decrease continuously in the course of the curing process before saturating at the end of the chemical reaction. This holds true for instance for the mass density, the refractive index, the chemical turnover and the hypersonic properties. The reason for this monotone behaviour is that the chemical reaction behaves like a continuous succession of irreversible phase transitions. These transitions are superposed by the sol-gel transition and possibly by the chemically induced glass transition, with the drawback that the latter two highlighted transitions are often hidden by the underlying curing process. In this work we propose generalized mode Grueneisen parameters as an alternative probe for elucidating the polymerization process itself and the closely related transition phenomena. As a model system we use polyurethane composed of a diisocyanate and varying ratios of difunctional and trifunctional alcohols.

  7. Anxiolytic and antidepressant effect of zinc on rats and its impact on general behavioural parameters

    Directory of Open Access Journals (Sweden)

    Samardžić Janko

    2013-01-01

    Full Text Available Background/Aim. Zinc is an essential element which has considerable interaction with gamma-aminobutyric acid A type receptors (GABAA and glutamate receptors in the central nervous system (CNS. It is believed that zinc acts as a potent inhibitor of glutamate N-methyl-D-aspartate (NMDA receptors, and binding to structurally specific site on the GABAA receptor leads to inhibition of GABA dependent Cl-pass. The aim of our research was to test the anxiolytic and antidepressant effects of zinc after single application and its influence on general behavioural parameters after repeated administration. Methods. Male Wistar rats were treated with increasing doses of zinc histidine dehydrate (10, 20, 30 mg/kg, i.p.. To determine anxiolytic and antidepressant properties of zinc two models were used: elevated plus maze (EPM and forced swim test (FST. Behavioural parameters (stillness and mobility were, also, recorded after single and repeated administration of active substance. Results. Testing animals in the EPM showed a statistically significant difference as follows: dose of 20 mg/kg significantly increased the time animals spent in open arms, indicating an acute anxiolytic effect, while doses of 30 mg/kg significantly reduced the time in the open arms, indicating a potentially anxiogenic effect. Testing the animals by FST showed a statistically significant difference in immobility time of animals treated with the lowest applied (10 mg/kg and highest applied (30 mg/kg doses of zinc, compared to the control group. The first day of testing behavioral parameters showed the tendency to increase locomotor activity of the animals with the lowest dose of zinc (10 mg/kg, while the following day revealed a reduced activity with the highest dose applied (30 mg/kg. Conclusion. Zinc has important effects on the CNS: After single application, in all doses zinc showed antidepressant effects. The effects of zinc on anxiety and locomotor activity showed dose

  8. Anxiolytic and antidepressive effects of magnesium in rats and their effect on general behavioural parameters

    Directory of Open Access Journals (Sweden)

    Samardžić Janko

    2011-01-01

    Full Text Available Magnesium (Mg is an essential element that catalyses more than 300 enzyme systems. Its effects on the central nervous system are exhibited through the blocking of activity of N-methyl D-aspartat (NMDA receptors and potentiating of GABA-ergic neurotransmission. Due to the vast importance of these two neurotransmission systems in the fine regulation of the central integrative function activity, the aim of this research was to test the anxiolytic and antidepressive effects of magnesium, after acute and repeated application, and its influence on general behavioural parameters. In this research Wistar albino rats were treated with increasing doses of Mg chloride 6-hydrate (MgCl 10, 20, 30 mg/kg. In order to determine anxiolytic and antidepressive properties of magnesium two models were used: elevated plus maze (EPM and forced swim test (FST. Behavioural parameters (stillness and mobility were recorded during acute and repeated administration of the active substance. Results of EPM testing showed no significant difference between groups, p>0.05. After acute application of increasing doses of magnesium chloride hydrate in FST, we showed the statistically significant difference in immobility time between the group of animals treated with Mg and the control group treated with the solvent, p<0.01. The statistically significant difference between groups treated with the lowest and the middle dose of magnesium and the controls was observed already on the first day of examining behavioural parameters (p=0.020, p=0.010. Our research has showed that magnesium, following acute administration, increases locomotor activity, and has an antidepressive but not an anxiolytic effect.

  9. Multi-parameter vital sign database to assist in alarm optimization for general care units.

    Science.gov (United States)

    Welch, James; Kanter, Benjamin; Skora, Brooke; McCombie, Scott; Henry, Isaac; McCombie, Devin; Kennedy, Rosemary; Soller, Babs

    2016-12-01

    Continual vital sign assessment on the general care, medical-surgical floor is expected to provide early indication of patient deterioration and increase the effectiveness of rapid response teams. However, there is concern that continual, multi-parameter vital sign monitoring will produce alarm fatigue. The objective of this study was the development of a methodology to help care teams optimize alarm settings. An on-body wireless monitoring system was used to continually assess heart rate, respiratory rate, SpO2 and noninvasive blood pressure in the general ward of ten hospitals between April 1, 2014 and January 19, 2015. These data, 94,575 h for 3430 patients are contained in a large database, accessible with cloud computing tools. Simulation scenarios assessed the total alarm rate as a function of threshold and annunciation delay (s). The total alarm rate of ten alarms/patient/day predicted from the cloud-hosted database was the same as the total alarm rate for a 10 day evaluation (1550 h for 36 patients) in an independent hospital. Plots of vital sign distributions in the cloud-hosted database were similar to other large databases published by different authors. The cloud-hosted database can be used to run simulations for various alarm thresholds and annunciation delays to predict the total alarm burden experienced by nursing staff. This methodology might, in the future, be used to help reduce alarm fatigue without sacrificing the ability to continually monitor all vital signs.

  10. [Drug advertising to the general public: conceptual parameters of a risk producer practice].

    Science.gov (United States)

    Nascimento, Alvaro César

    2010-11-01

    This article analyzes some concepts relating to marketing, advertising, medications, regulation and manipulation. It discusses ethical and health surveillance parameters of drugs advertising for the general public. The focus of this work is the analysis of contradictions from a conceptual point of view between the practice of pharmaceutical advertising as a tool for the increase of sales and the conquest of markets versus the policy of rational use of medicines. Academic studies and monitoring of drugs advertising conducted by the National Health Surveillance Agency show that the contents of the advertising pieces oriented towards the general public overestimate the - sometimes dubious - qualities of their medication, focusing almost exclusively on the benefits and put them in a central position in the therapeutic process. They also fail to mention the risks inherent in their use. Rather than focusing on regulatory proposals aimed at creating constraints to this practice, this article discusses the impossibility, considering the interests of public health, of the coexistence of marketing with the policies for the correct, rational and safe use of drugs.

  11. Evaluating the influence of epidemiological parameters and host ecology on the spread of phocine distemper virus through populations of harbour seals.

    Directory of Open Access Journals (Sweden)

    Catriona M Harris

    Full Text Available BACKGROUND: Outbreaks of phocine distemper virus (PDV in Europe during 1988 and 2002 were responsible for the death of around 23,000 and 30,000 harbour seals, respectively. These epidemics, particularly the one in 2002, provided an unusual opportunity to estimate epidemic parameters for a wildlife disease. There were marked regional differences in the values of some parameters both within and between epidemics. METHODOLOGY AND PRINCIPAL FINDINGS: We used an individual-based model of seal movement that allowed us to incorporate realistic representations of space, time and animal behaviour into a traditional epidemiological modelling framework. We explored the potential influence of a range of ecological (foraging trip duration, time of epidemic onset, population size and epidemiological (length of infectious period, contact rate between infectious and susceptible individuals, case mortality parameters on four readily-measurable epidemic characteristics (number of dead individuals, duration of epidemic, peak mortality date and prevalence and on the probability that an epidemic would occur in a particular region. We analysed the outputs as if they were the results of a series of virtual experiments, using Generalised Linear Modelling. All six variables had a significant effect on the probability that an epidemic would be recognised as an unusual mortality event by human observers. CONCLUSIONS: Regional and temporal variation in contact rate was the most likely cause of the observed differences between the two epidemics. This variation could be a consequence of differences in the way individuals divide their time between land and sea at different times of the year.

  12. [The information on a sanitary-and-epidemiologic condition of general educational establishments and catering services of schoolboys].

    Science.gov (United States)

    Onishchenko, G G

    2008-01-01

    The federal service on supervision in sphere of protection of the rights of consumers and well-being of the person develops normative and methodical documents, including sanitary rules and the norms defining hygienic parameters of food value of food raw material and foodstuff, children used in a feed and teenagers; requirements to catering services of pupils of various types of teaching and educational establishments. Decisions of the Main state health officer of the Russian Federation, the conditions directed on improvement and catering services in educational establishments are published. At participation of Rospotrebnadzor's experts on subjects of the Russian Federation the regional programs directed on improvement of catering services of pupils are developed. The information on a condition of general educational establishments with offers on improvement of a sanitary-engineering condition, goes to address of enforcement authorities.

  13. Studies on nutritional status in general surgery patients by clinical, anthropometric, and laboratory parameters.

    Science.gov (United States)

    Butters, M; Straub, M; Kraft, K; Bittner, R

    1996-06-01

    We assessed the nutritional status of general surgery patients with and without cancer from a western European population in this prospective study. Anamnestic (weight development, abdominal complaints) and anthropometric (fat tissue measurements) data were collected on six groups of patients: cancer of the stomach (n = 13), pancreas (n = 13), colorectal (n = 23), breast (n = 12), and two control groups with benign diseases, ages 20-45 and 50-75 y. From these data, body mass index and ideal body weight were calculated. Concentrations of albumin, transferrin, retinol-binding protein, prealbumin, and creatinine height index were determined by biochemical tests. A weight loss of more than 10% was found in only 31% of gastric and 61% of pancreatic cancer patients. Significant values from anthropometric data were also found only in these groups. In biochemical tests, only the creatinine height index was reduced in all patients with pancreatic cancer. The remaining laboratory changes were so unspecific in all other parameters that no conclusions could be drawn as to the status of the patient's nutritional condition. For the evaluation of nutritional status, only relatively simple and inexpensive anamnestic and anthropometric measurements are necessary.

  14. The Advanced Camera for Surveys General Catalog: Structural Parameters for Approximately Half a Million Galaxies

    CERN Document Server

    Griffith, Roger L; Newman, Jeffrey A; Moustakas, Leonidas A; Stern, Daniel; Comerford, Julia M; Davis, Marc; Lotz, Jennifer M; Barden, Marco; Conselice, Christopher J; Capak, Peter L; Faber, S M; Kirkpatrick, J Davy; Koekemoer, Anton M; Koo, David C; Noeske, Kai G; Scoville, Nick; Sheth, Kartik; Shopbell, Patrick; Willmer, Christopher N A; Weiner, Benjamin

    2012-01-01

    We present the Advanced Camera for Surveys General Catalog (ACS-GC), a photometric and morphological database using publicly available data obtained with the Advanced Camera for Surveys (ACS) instrument on the Hubble Space Telescope. The goal of the ACS-GC database is to provide a large statistical sample of galaxies with reliable structural and distance measurements to probe the evolution of galaxies over a wide range of look-back times. The ACS-GC includes over 490,000 astronomical sources (stars + galaxies) derived from the AEGIS, COSMOS, GEMS, and GOODS surveys. Galapagos was used to construct photometric (SExtractor) and morphological (Galfit) catalogs. The analysis assumes a single S\\'ersic model for each object to derive quantitative structural parameters. We include publicly available redshifts from the DEEP2, COMBO-17, TKRS, PEARS, ACES, CFHTLS,and zCOSMOS surveys to supply redshifts (spectroscopic and photometric) for a considerable fraction (~71%) of the imaging sample. The ACS-GC includes color po...

  15. [Malignant melanoma of the skin as evidenced by epidemiological cancer registries in Germany -- incidence, clinical parameters, variations in recording].

    Science.gov (United States)

    Lehnert, M; Eberle, A; Hentschel, S; Katalinic, A; Kieschke, J; Schmidtmann, I; Schubert-Fritschle, G; Stegmaier, C; Hense, H-W

    2005-10-01

    To exclude bias of registration evidenced by relevant differences among German cancer registries in the incidence of malignant melanoma (melanocarcinoma). Cancer registries in the Federal German states of Hamburg, Schleswig-Holstein, Bremen, Rhineland-Palatinate, Saarland, the Munich District and the County of Münster featured registration data of malignant melanoma diagnosed in 2000 A. D. Figures and incidence rates, distribution of T-stage of the primary tumour were analysed as well as the distribution of sources reporting melanoma to the registries. Details of outpatient treatment of cutaneous melanoma by dermatologists in private practice were investigated. Data of 2,471 malignant melanoma cases were analysed. The highest age standardised incidence rates were 15.7 per 100,000 women and 19 per 100,000 men while the lowest rates were reported as 7.8 and 6.6 per 100,000, respectively (European standard). The proportion of stage T1 tumours varied between 21.5 and 59.2 %. We observed remarkable variations in the structure of reporting sources among the registries. The proportion of reports from dermatologists in private practice varied between 2.2 and 62 %, with higher proportions associated with more T1-T2 tumours but also lower completeness of stage reports. No clear association was identified between incidence of melanoma and reporting sources. Malignant melanomas of smaller size (T1-T2) are reported more frequently in an outpatient setting but very often without data. Hospital departments of dermatology contribute high-quality data with better completeness especially for later stage melanomas. Desirable inclusion of notifications from nationwide operating dermatopathology laboratories is complicated by the Federal German structure of cancer registration. Especially in case of malignant melanoma of the skin notification reports from all sectors of the health care system are imperative for valid epidemiological results.

  16. Histopathologic, stereologic, epidemiologic, and clinical parameters in the prognostic evaluation of squamous cell carcinoma of the oral cavity

    DEFF Research Database (Denmark)

    Bundgaard, T; Bentzen, S M; Wildt, J

    1996-01-01

    = .01), vascular invasion (P = .02), depth (P = .006), and mean histologic score. Tobacco consumption was borderline significant (P = .055). A multivariate analysis using the Cox proportional hazard analysis showed that both clinical (stage, P tobacco...... in terms of cause-specific survival for T stage (P consumption (P = .03), stereologic estimates of nuclear volume (P = .04), and the histomorphologic parameters mode of invasion (P = .001), pattern (P...... consumption, P = .0054), morphohistopathologic (mode of invasion P

  17. " Evaluation Of Some Epidemiologic Parameters, Risk Factors, Clinical And Audiological Characteristics Of 48 Patients With Sudden Sensorineural Hearing Loss "

    Directory of Open Access Journals (Sweden)

    M. Amiridavan

    2006-05-01

    Full Text Available Background and Aim: Sudden Sensorineural Hearing Loss (SSNHL is an emergency situation, and is one of the most controversial subjects in domain of otolaryngology. In this article, we have analyzed some Epidemiologic Characteristics, clinical features, audiological Characteristics, and other findings in routine serological tests and MRI of 48 cases with SSNHL ,who came or were referred to us in the past 2 years. Study design: Cross sectional. Materials and Methods: In 48 patients with chief complaint of SSNHL, from June 2003 to Feb. 2005, who were admitted in clinic of otolaryngology- in Kashani Hospital -Isfahan- Iran, physical examination and history taking, audiological evaluation, MRI,and serological tests were performed in a similar way , and data were analyzed by SPSS software. Results: From 48 cases(M:28 ,F:20 with mean age of 40.9(+/-15.9 years, left ear was involved in 26 cases (54.1% ,and right ear in 19 cases (39.5% ,and in 3 cases (6.3%,both sides were involved. The severity of hearing loss was “subjectively” HIGH in 78% of patients, and the mean threshold of hearing had been calculated as 69 dB. The most common pattern in pure tone audiometry curves ,was ‘flat pattern’(75% ,and then ,’down sloping pattern’(16%.The most adjunctive clinical symptom was “tinnitus”(in 78.7%, and 40% of patients had “true vertigo”. 44.4% of our patients had some evidences of upper respiratory tract infections (URIs during recent 2 weeks. Positive family history, smoking, alcohol intake ,oral contraceptive and ototoxic drugs consumption were uncommon. 24% of cases (11 of 39 had increased ESR, and 100% of 39 patients had negative VDRL. Diabetes mellitus was the most common underlying disease (in 6 cases.From 20 patients ,who were succeeded to perform brain and ear MRI, 2 cases had tumor in internal auditory canal and cerebellopontine angle. Conclusion: SSNHL has some limitations in being studied histopathologically or in the form of

  18. Generalized function of the parameters in the storage-discharge relation for low flows

    Science.gov (United States)

    Fujimura, Kazumasa; Iseri, Yoshihiko; Kanae, Shinjiro; Murakami, Masahiro

    2015-04-01

    The accurate estimation of low flows can contribute to better water resource management and more reliable evaluation of the impact of climate change on water resources. For the case of low flows, the nonlinearity of the discharge Q associated with the storage S was originally proposed by Horton (1936) as the power function Q=KSN, where K is a constant and N is the exponent. Although the Q(S) relations for groundwater runoff from unconfined aquifers have been treated as second-order polynomial functions on the basis of the hydraulic investigation by Ding (1966), the general power function Q = KNSN was introduced into the unit hydrograph model for overland flow and the parameters K and N were calibrated by Ding (2011). According to recent studies, the value of the exponent N is varied between 1 and 3 or higher by calibration (e.g., Wittenberg, 1994 and Ding, 2011); however, it is currently unclear whether the optimum value of N has the rule. Fujimura et al. (2014) applied the general power function Q = KNSN for low flows in mountainous basins over a period spanning more than 10 years using hourly data, and carried out sensitivity analysis using a hydrological model for 19 900 sets of the two parameters K and N, in which the exponent N was varied between 1 and 100 in steps of 0.5. The results showed that the optimum relation between N and K could be characterized by the exponential function K=1/(α Nβ), where α and β are constants. Moreover, the lowest error in the sensitivity analysis was obtained by using an exponent N of 100. The aim of this study is to extend the previous study of Fujimura et al. to clarify the properties of the K(N) relations. A sensitivity analysis is performed efficiently using a hydrological model, in which the exponent N is varied between 1 and 100 000 along the neighborhood of the exponential function K=1/(α Nβ). The hourly hydrological model used in this study comprises the Diskin-Nazimov infiltration model, groundwater recharge and

  19. Sequence-based Parameter Estimation for an Epidemiological Temporal Aftershock Forecasting Model using Markov Chain Monte Carlo Simulation

    Science.gov (United States)

    Jalayer, Fatemeh; Ebrahimian, Hossein

    2014-05-01

    Introduction The first few days elapsed after the occurrence of a strong earthquake and in the presence of an ongoing aftershock sequence are quite critical for emergency decision-making purposes. Epidemic Type Aftershock Sequence (ETAS) models are used frequently for forecasting the spatio-temporal evolution of seismicity in the short-term (Ogata, 1988). The ETAS models are epidemic stochastic point process models in which every earthquake is a potential triggering event for subsequent earthquakes. The ETAS model parameters are usually calibrated a priori and based on a set of events that do not belong to the on-going seismic sequence (Marzocchi and Lombardi 2009). However, adaptive model parameter estimation, based on the events in the on-going sequence, may have several advantages such as, tuning the model to the specific sequence characteristics, and capturing possible variations in time of the model parameters. Simulation-based methods can be employed in order to provide a robust estimate for the spatio-temporal seismicity forecasts in a prescribed forecasting time interval (i.e., a day) within a post-main shock environment. This robust estimate takes into account the uncertainty in the model parameters expressed as the posterior joint probability distribution for the model parameters conditioned on the events that have already occurred (i.e., before the beginning of the forecasting interval) in the on-going seismic sequence. The Markov Chain Monte Carlo simulation scheme is used herein in order to sample directly from the posterior probability distribution for ETAS model parameters. Moreover, the sequence of events that is going to occur during the forecasting interval (and hence affecting the seismicity in an epidemic type model like ETAS) is also generated through a stochastic procedure. The procedure leads to two spatio-temporal outcomes: (1) the probability distribution for the forecasted number of events, and (2) the uncertainty in estimating the

  20. Towards all-order Laurent expansion of generalized hypergeometric functions around rational values of parameters

    Energy Technology Data Exchange (ETDEWEB)

    Kalmykov, M.Yu.; Kniehl, B.A. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2008-07-15

    We prove the following theorems: 1) The Laurent expansions in {epsilon} of the Gauss hypergeometric functions {sub 2}F{sub 1}(I{sub 1}+a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z), {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+a{epsilon},I{sub 2}+(p/q)+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z) and {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+ a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+(p)/(q)+c{epsilon};z), where I{sub 1},I{sub 2},I{sub 3},p,q are arbitrary integers, a,b,c are arbitrary numbers and {epsilon} is an infinitesimal parameter, are expressible in terms of multiple polylogarithms of q-roots of unity with coefficients that are ratios of polynomials; 2) The Laurent expansion of the Gauss hypergeometric function {sub 2}F{sub 1}(I{sub 1}+(p)/(q)+a{epsilon},I{sub 2}+b{epsilon};I{sub 3}+c{epsilon};z) is expressible in terms of multiple polylogarithms of q-roots of unity times powers of logarithm with coefficients that are ratios of polynomials; 3) The multiple inverse rational sums {sigma}{sup {infinity}}{sub j=1}({gamma}(j))/({gamma}(1+j-(p)/(q))) (z{sup j})/(j{sup c}) S{sub a{sub 1}}(j-1).. S{sub a{sub p}}(j-1) and the multiple rational sums {sigma}{sup {infinity}}{sub j=1} ({gamma}(j+(p)/(q)))/({gamma}(1+j)) (z{sup j})/(j{sup c}) S{sub a{sub 1}}(j-1).. S{sub a{sub p}}(j-1), where S{sub a}(j)={sigma}{sup j}{sub k=1}(1)/(k{sup a}) is a harmonic series and c is an arbitrary integer, are expressible in terms of multiple polylogarithms; 4) The generalized hypergeometric functions {sub p}F{sub p.1}((vector)A+(vector)a{epsilon};(vector)B+(vector)b{epsilon},(p)/(q)+B{sub p-1};z) and {sub p}F{sub p-1}((vector)A+(vector)a{epsilon},(p)/(q)+A{sub p};(vector)B+(vector)b{epsilon};z) are expressible in terms of multiple polylogarithms with coefficients that are ratios of polynomials. (orig.)

  1. Automation of the CHARMM General Force Field (CGenFF) II: Assignment of bonded parameters and partial atomic charges

    Science.gov (United States)

    Vanommeslaeghe, K.; Raman, E. Prabhu; MacKerell, A. D.

    2012-01-01

    Molecular mechanics force fields are widely used in computer-aided drug design for the study of drug candidates interacting with biological systems. In these simulations, the biological part is typically represented by a specialized biomolecular force field, while the drug is represented by a matching general (organic) force field. In order to apply these general force fields to an arbitrary drug-like molecule, functionality for assignment of atom types, parameters and partial atomic charges is required. In the present article, algorithms for the assignment of parameters and charges for the CHARMM General Force Field (CGenFF) are presented. These algorithms rely on the existing parameters and charges that were determined as part of the parametrization of the force field. Bonded parameters are assigned based on the similarity between the atom types that define said parameters, while charges are determined using an extended bond-charge increment scheme. Charge increments were optimized to reproduce the charges on model compounds that were part of the parametrization of the force field. A “penalty score” is returned for every bonded parameter and charge, allowing the user to quickly and conveniently assess the quality of the force field representation of different parts of the compound of interest. Case studies are presented to clarify the functioning of the algorithms and the significance of their output data. PMID:23145473

  2. Review on the New Development of General Epidemiological Concept%从哲学的角度探讨广义流行病学概念发展

    Institute of Scientific and Technical Information of China (English)

    秦雅楠; 滕国兴

    2012-01-01

    The new research fruits from related theory of many disciplines are use for reference, the study apply the dialectical logic and formal logic method to explore the new development of the epidemiological concept -connotation (definition) and denotation (classification) in new epidemiological development history and present situation. The results reveal that general epidemiology is a science which reveals the regularity of occurrence, development and distribution, analysis the relation, nature and strength between public health events and certain influencing elements, which are essential tools to formulate effective, safe economic and acceptable strategies and measures to prevent public health problems caused by exposure, which will help to summarizes the theoretical system of the perfect epidemiology science.%应用辩证逻辑、形式逻辑方法;借鉴诸多学科相关理论的新成果;结合流行病学发展历史与现状;探讨了流行病学概念新发展.研究结果表明;广义流行病学是一门揭示公众卫生问题的发生、发展与分布规律;分析问题与因素间关联的有无、性质及强度;研究应对策略、措施的有效性、安全性、经济性和可接受性;总结完善流行病学理论体系的科学.

  3. Generalized Extreme Value's shape parameter and its nature for extreme precipitation using long time series and Bayesian approach

    Science.gov (United States)

    Ragulina, Galina; Reitan, Trond

    2016-04-01

    Assessing the probability of extreme precipitation events is of great importance in civil planning. This requires understanding of how return values change with different return periods, which is essentially described by the Generalized Extreme Value distribution's shape parameter. Some works in the field have suggested a constant shape parameter, while our analysis indicates a non-universal value. We first re-analyse an older precipitation dataset (169 stations) extended by Norwegian data (71 stations). We show that while each set seems to have a constant shape parameter, it differs between the two datasets, indicating regional differences. For a more comprehensive analysis of spatial effects, we examine a global dataset (1495 stations). We provide shape parameter maps for two models. We find clear evidence for the shape parameter being dependent on elevation while the effect of latitude remains uncertain. Our results confirm an explanation in terms of dominating precipitation systems based on a proxy derived from the Köppen-Geiger climate classification.

  4. The Epidemiology of Pulmonary Nontuberculous Mycobacteria: Data from a General Hospital in Athens, Greece, 2007–2013

    Directory of Open Access Journals (Sweden)

    Marios Panagiotou

    2014-01-01

    Full Text Available Background. The epidemiology of pulmonary nontuberculous mycobacteria (NTM in Greece is largely unknown. Objectives. To determine the incidence and the demographic, microbiological, and clinical characteristics of patients with pulmonary NTM infection and pulmonary NTM disease. Methods. A retrospective review of the demographic, microbiological, and clinical characteristics of patients with NTM culture-positive respiratory specimens from January 2007 to May 2013. Results. A total of 120 patients were identified with at least one respiratory NTM isolate and 56 patients (46% fulfilled the microbiological ATS/IDSA criteria for NTM disease. Of patients with adequate data, 16% fulfilled the complete ATS/IDSA criteria for NTM disease. The incidence of pulmonary NTM infection and disease was 18.9 and 8.8 per 100.000 inpatients and outpatients, respectively. The spectrum of NTM species was high (13 species and predominated by M. avium-intracellulare complex (M. avium (13%, M. intracellulare (10%, M. gordonae (14%, and M. fortuitum (12%. The ratio of isolation of NTM to M. tuberculosis in all hospitalized patients was 0.59. Conclusions. The first data on the epidemiology of pulmonary NTM in Athens, Greece, are presented. NTM infection is common in patients with chronic respiratory disease. However, only a significantly smaller proportion of patients fulfill the criteria for NTM disease.

  5. Modeling phase equilibria of alkanols with the simplified PC-SAFT equation of state and generalized pure compound parameters

    DEFF Research Database (Denmark)

    Grenner, Andreas; Kontogeorgis, Georgios; von Solms, Nicolas

    2007-01-01

    The simplified PC-SAFT equation of state has been applied to liquid-liquid, vapor-liquid and solid-liquid equilibria for mixtures containing 1-or 2-alkanols with alkanes, aromatic hydrocarbons, CO2 and water. For the alkanols we use generalized pure compound parameters. This means that two...

  6. An alternative order-parameter for non-equilibrium generalized spin models on honeycomb lattices

    Science.gov (United States)

    Sastre, Francisco; Henkel, Malte

    2016-04-01

    An alternative definition for the order-parameter is proposed, for a family of non-equilibrium spin models with up-down symmetry on honeycomb lattices, and which depends on two parameters. In contrast to the usual definition, our proposal takes into account that each site of the lattice can be associated with a local temperature which depends on the local environment of each site. Using the generalised voter motel as a test case, we analyse the phase diagram and the critical exponents in the stationary state and compare the results of the standard order-parameter with the ones following from our new proposal, on the honeycomb lattice. The stationary phase transition is in the Ising universality class. Finite-size corrections are also studied and the Wegner exponent is estimated as ω =1.06(9).

  7. Bianchi Type-II inflationary models with constant deceleration parameter in general relativity

    Indian Academy of Sciences (India)

    C P Singh; S Kumar

    2007-05-01

    Einstein's field equations are considered for a locally rotationally symmetric Bianchi Type-II space–time in the presence of a massless scalar field with a scalar potential. Exact solutions of scale factors and other physical parameters are obtained by using a special law of variation for Hubble's parameter that yields a constant value of deceleration parameter. To get inflationary solutions, a flat region is considered in which the scalar potential is constant. Power-law and exponential cases are studied and in both solutions there is an anisotropic expansion of the cosmic fluid, but the fluid has vanishing vorticity. A detailed study of geometrical and kinematical properties of solutions has been carried out.

  8. Parameter Estimation of Approximated Generalized Least Squares Estimators for the Generalized Pareto Distribution%广义Pareto分布近似广义最小二乘估计

    Institute of Scientific and Technical Information of China (English)

    赵旭; 薛留根; 李婧兰; 程维虎

    2012-01-01

    The generalized Pareto distribution(GPD) is one of the most important distribution in statistics analysis.This paper is based on sample quantiles of the GPD.First,the shape parameter estimator that has high estimated precision is solved,then the approximated generalized least squares estimation expressions of the location and scale parameters are obtained for the GPD.The proposed method is easy and has no limitation for the shape parameter.In addition,it has high estimation accuracy under Monte-Carlo simulation tests.%广义Pareto分布(generalized Pareto distribution,GPD)是统计分析中的一个极为重要的分布.对基于广义Pareto分布的若干个样本分位数进行了研究.首先,求解具有较高精度的形状参数的参数估计;其次,得出广义Pareto分布位置参数及尺度参数的近似广义最小二乘估计.本方法简单易行,对形状参数的存在条件没有限制,通过Monte Carlo模拟验证了该方法具有较高的精度.

  9. A general form of the cross energy parameter of equations of state

    DEFF Research Database (Denmark)

    Coutinho, Joao A. P.; Panayiotis, Vlamos; Kontogeorgis, Georgios

    2000-01-01

    . The proposed rule is derived from molecular considerations, namely, the London−Mie theory. The typically used geometric mean (GM) and other combining rules can be deducted from this expression from different values of the parameter n, which is the attractive tail of the Mie potential. We show that using this n...

  10. Epidemiologic parameters and evaluation of control measure for 2009 novel influenza a (H1N1 in Xiamen, Fujian Province, China

    Directory of Open Access Journals (Sweden)

    Shen Jinyu

    2012-01-01

    Full Text Available Abstract Background Containment of influenza A H1N1 virus spread was implemented successfully in Xiamen, with large-scale inoculation to reduce morbidity. To identify beneficial elements and to guide decision-making in epidemic containment, we analyzed the epidemiologic parameters and evaluated the control measures. Method We determined various parameters from laboratory-confirmed cases, including incubation period, duration of illness and reproductive number (R0, and evaluated the control measures. Results There were1414 cases with dates of onset between June 14, 2009 and March 22, 2010. The incidence was 56.79/100,000, and mortality was 0.12/100,000. The incidence during the community epidemic phase was 6.23 times higher than in the containment phase. A total of 296,888 subjects were inoculated with domestic influenza H1N1 virus cleavage vaccine. An epidemic curve showed that vaccination in students cut the peak incidence of illness significantly. Men (relative risk (RR = 1.30, 95% confidence interval (CI: 1.17-1.45 and persons aged 0-14 years were at greater risk of infection. The incidence increased with younger age (χ2 = 950.675, p = ∞. Morbidity was lower in urban than in rural areas (RR = 0.56, 95%CI: 0.50-0.62. The median incubation time was 2 days, median duration of symptoms was 7 days, and the within-school reproductive number was 1.35. Conclusion Our analysis indicated that the characteristics of this novel influenza virus were similar to those of seasonal influenza. The principle of "interception of imported cases" applied at Xiamen ports, and vaccination of students effectively limited the spread of the influenza pandemic and reduced the epidemic peak.

  11. Denoising Algorithm Based on Generalized Fractional Integral Operator with Two Parameters

    Directory of Open Access Journals (Sweden)

    Hamid A. Jalab

    2012-01-01

    Full Text Available In this paper, a novel digital image denoising algorithm called generalized fractional integral filter is introduced based on the generalized Srivastava-Owa fractional integral operator. The structures of n×n fractional masks of this algorithm are constructed. The denoising performance is measured by employing experiments according to visual perception and PSNR values. The results demonstrate that apart from enhancing the quality of filtered image, the proposed algorithm also reserves the textures and edges present in the image. Experiments also prove that the improvements achieved are competent with the Gaussian smoothing filter.

  12. Epidemiology of general joint hypermobility and basis for the proposed criteria for benign joint hypermobility syndrome: review of the literature

    DEFF Research Database (Denmark)

    Remvig, Lars; Jensen, Dorte V; Ward, Robert C

    2007-01-01

    This literature review of generalized joint hypermobility (GJH) syndromes discusses information regarding sex-, age-, and race-related factors from publications that specifically document validated GJH criteria.......This literature review of generalized joint hypermobility (GJH) syndromes discusses information regarding sex-, age-, and race-related factors from publications that specifically document validated GJH criteria....

  13. Epidemiology of general joint hypermobility and basis for the proposed criteria for benign joint hypermobility syndrome: review of the literature

    DEFF Research Database (Denmark)

    Remvig, Lars; Jensen, Dorte V; Ward, Robert C

    2007-01-01

    This literature review of generalized joint hypermobility (GJH) syndromes discusses information regarding sex-, age-, and race-related factors from publications that specifically document validated GJH criteria.......This literature review of generalized joint hypermobility (GJH) syndromes discusses information regarding sex-, age-, and race-related factors from publications that specifically document validated GJH criteria....

  14. A Generalized Information Criterion for Parameters under an Umbrella Order Restriction

    Institute of Scientific and Technical Information of China (English)

    宋海燕; 陶剑; 史宁中

    2005-01-01

    The detection of the configuration of parameters is one of the most important problems im statistical studies. It is well known that the Akaike's information criterion (AIC) is a key tool for this problem (see [1]). Usually, the AIC is defined as: AIC(μ) := l(μ) -p, where l(μ) is the log-likelihood with the maximum likelihood estimator (MLE) μ for μ,

  15. Estimating parameters of generalized integrate-and-fire neurons from the maximum likelihood of spike trains.

    Science.gov (United States)

    Dong, Yi; Mihalas, Stefan; Russell, Alexander; Etienne-Cummings, Ralph; Niebur, Ernst

    2011-11-01

    When a neuronal spike train is observed, what can we deduce from it about the properties of the neuron that generated it? A natural way to answer this question is to make an assumption about the type of neuron, select an appropriate model for this type, and then choose the model parameters as those that are most likely to generate the observed spike train. This is the maximum likelihood method. If the neuron obeys simple integrate-and-fire dynamics, Paninski, Pillow, and Simoncelli (2004) showed that its negative log-likelihood function is convex and that, at least in principle, its unique global minimum can thus be found by gradient descent techniques. Many biological neurons are, however, known to generate a richer repertoire of spiking behaviors than can be explained in a simple integrate-and-fire model. For instance, such a model retains only an implicit (through spike-induced currents), not an explicit, memory of its input; an example of a physiological situation that cannot be explained is the absence of firing if the input current is increased very slowly. Therefore, we use an expanded model (Mihalas & Niebur, 2009 ), which is capable of generating a large number of complex firing patterns while still being linear. Linearity is important because it maintains the distribution of the random variables and still allows maximum likelihood methods to be used. In this study, we show that although convexity of the negative log-likelihood function is not guaranteed for this model, the minimum of this function yields a good estimate for the model parameters, in particular if the noise level is treated as a free parameter. Furthermore, we show that a nonlinear function minimization method (r-algorithm with space dilation) usually reaches the global minimum.

  16. A new and consistent parameter for measuring the quality of multivariate analytical methods: Generalized analytical sensitivity.

    Science.gov (United States)

    Fragoso, Wallace; Allegrini, Franco; Olivieri, Alejandro C

    2016-08-24

    Generalized analytical sensitivity (γ) is proposed as a new figure of merit, which can be estimated from a multivariate calibration data set. It can be confidently applied to compare different calibration methodologies, and helps to solve literature inconsistencies on the relationship between classical sensitivity and prediction error. In contrast to the classical plain sensitivity, γ incorporates the noise properties in its definition, and its inverse is well correlated with root mean square errors of prediction in the presence of general noise structures. The proposal is supported by studying simulated and experimental first-order multivariate calibration systems with various models, namely multiple linear regression, principal component regression (PCR) and maximum likelihood PCR (MLPCR). The simulations included instrumental noise of different types: independently and identically distributed (iid), correlated (pink) and proportional noise, while the experimental data carried noise which is clearly non-iid.

  17. Expectation-Maximization Algorithms for Obtaining Estimations of Generalized Failure Intensity Parameters

    Directory of Open Access Journals (Sweden)

    Makram KRIT

    2016-01-01

    Full Text Available This paper presents several iterative methods based on Stochastic Expectation-Maximization (EM methodology in order to estimate parametric reliability models for randomly lifetime data. The methodology is related to Maximum Likelihood Estimates (MLE in the case of missing data. A bathtub form of failure intensity formulation of a repairable system reliability is presented where the estimation of its parameters is considered through EM algorithm . Field of failures data from industrial site are used to fit the model. Finally, the interval estimation basing on large-sample in literature is discussed and the examination of the actual coverage probabilities of these confidence intervals is presented using Monte Carlo simulation method.

  18. Variable Selection for Generalized Varying Coefficient Partially Linear Models with Diverging Number of Parameters

    Institute of Scientific and Technical Information of China (English)

    Zheng-yan Lin; Yu-ze Yuan

    2012-01-01

    Semiparametric models with diverging number of predictors arise in many contemporary scientific areas. Variable selection for these models consists of two components: model selection for non-parametric components and selection of significant variables for the parametric portion.In this paper,we consider a variable selection procedure by combining basis function approximation with SCAD penalty.The proposed procedure simultaneously selects significant variables in the parametric components and the nonparametric components.With appropriate selection of tuning parameters,we establish the consistency and sparseness of this procedure.

  19. A generalized ARFIMA process with Markov-switching fractional differencing parameter

    OpenAIRE

    Tsay, Wen-Jen; Härdle, Wolfgang Karl

    2007-01-01

    We propose a general class of Markov-switching-ARFIMA processes in order to combine strands of long memory and Markov-switching literature. Although the coverage of this class of models is broad, we show that these models can be easily estimated with the DLV algorithm proposed. This algorithm combines the Durbin-Levinson and Viterbi procedures. A Monte Carlo experiment reveals that the finite sample performance of the proposed algorithm for a simple mixture model of Markov-switching mean and ...

  20. Parameter estimation of linear and quadratic chirps by employing the fractional fourier transform and a generalized time frequency transform

    Indian Academy of Sciences (India)

    Shishir B Sahay; T Meghasyam; Rahul K Roy; Gaurav Pooniwala; Sasank Chilamkurthy; Vikram Gadre

    2015-06-01

    This paper is targeted towards a general readership in signal processing. It intends to provide a brief tutorial exposure to the Fractional Fourier Transform, followed by a report on experiments performed by the authors on a Generalized Time Frequency Transform (GTFT) proposed by them in an earlier paper. The paper also discusses the extension of the uncertainty principle to the GTFT. This paper discusses some analytical results of the GTFT. We identify the eigenfunctions and eigenvalues of the GTFT. The time shift property of the GTFT is discussed. The paper describes methods for estimation of parameters of individual chirp signals on receipt of a noisy mixture of chirps. A priori knowledge of the nature of chirp signals in the mixture – linear or quadratic is required, as the two proposed methods fall in the category of model-dependent methods for chirp parameter estimation.

  1. Generalized Grüneisen parameters and low temperature limit of lattice thermal expansion of cadmium and zirconium

    Indian Academy of Sciences (India)

    S Sindhu; C S Menon

    2006-09-01

    The generalized Grüneisen parameters ($_{j}^{'}$) and ($_{j}^{''}$) for cadmium and zirconium were calculated from the second- and third-order elastic constants to determine the low temperature limit of the volume thermal expansion of these metals of hexagonal symmetry. The low temperature limit of cadmium and zirconium was calculated to be positive values indicating a positive volume expansion down to 0 K even though many Grüneisen gammas were found to be negative.

  2. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection

    Science.gov (United States)

    Lai, Zhi-Hui; Leng, Yong-Gang

    2015-01-01

    A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application. PMID:26343671

  3. A generalized Lyapunov theory for robust root clustering of linear state space models with real parameter uncertainty

    Science.gov (United States)

    Yedavalli, R. K.

    1992-01-01

    The problem of analyzing and designing controllers for linear systems subject to real parameter uncertainty is considered. An elegant, unified theory for robust eigenvalue placement is presented for a class of D-regions defined by algebraic inequalities by extending the nominal matrix root clustering theory of Gutman and Jury (1981) to linear uncertain time systems. The author presents explicit conditions for matrix root clustering for different D-regions and establishes the relationship between the eigenvalue migration range and the parameter range. The bounds are all obtained by one-shot computation in the matrix domain and do not need any frequency sweeping or parameter gridding. The method uses the generalized Lyapunov theory for getting the bounds.

  4. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection.

    Science.gov (United States)

    Lai, Zhi-Hui; Leng, Yong-Gang

    2015-08-28

    A two-dimensional Duffing oscillator which can produce stochastic resonance (SR) is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR) model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.

  5. Generalized Parameter-Adjusted Stochastic Resonance of Duffing Oscillator and Its Application to Weak-Signal Detection

    Directory of Open Access Journals (Sweden)

    Zhi-Hui Lai

    2015-08-01

    Full Text Available A two-dimensional Duffing oscillator which can produce stochastic resonance (SR is studied in this paper. We introduce its SR mechanism and present a generalized parameter-adjusted SR (GPASR model of this oscillator for the necessity of parameter adjustments. The Kramers rate is chosen as the theoretical basis to establish a judgmental function for judging the occurrence of SR in this model; and to analyze and summarize the parameter-adjusted rules under unmatched signal amplitude, frequency, and/or noise-intensity. Furthermore, we propose the weak-signal detection approach based on this GPASR model. Finally, we employ two practical examples to demonstrate the feasibility of the proposed approach in practical engineering application.

  6. A generalized Lyapunov theory for robust root clustering of linear state space models with real parameter uncertainty

    Science.gov (United States)

    Yedavalli, R. K.

    1992-01-01

    The problem of analyzing and designing controllers for linear systems subject to real parameter uncertainty is considered. An elegant, unified theory for robust eigenvalue placement is presented for a class of D-regions defined by algebraic inequalities by extending the nominal matrix root clustering theory of Gutman and Jury (1981) to linear uncertain time systems. The author presents explicit conditions for matrix root clustering for different D-regions and establishes the relationship between the eigenvalue migration range and the parameter range. The bounds are all obtained by one-shot computation in the matrix domain and do not need any frequency sweeping or parameter gridding. The method uses the generalized Lyapunov theory for getting the bounds.

  7. Application of a generalized likelihood function for parameter inference of a carbon balance model using multiple, joint constraints

    Science.gov (United States)

    Hammerle, Albin; Wohlfahrt, Georg; Schoups, Gerrit

    2014-05-01

    Advances in automated data collection systems enabled ecologists to collect enormous amounts of varied data. Data assimilation (or data model synthesis) is one way to make sense of this mass of data. Given a process model designed to learn about ecological processes these data can be integrated within a statistical framework for data interpretation and extrapolation. Results of such a data assimilation framework clearly depend on the information content of the observed data, on the associated uncertainties (data uncertainties, model structural uncertainties and parameter uncertainties) and underlying assumptions. Parameter estimation is usually done by minimizing a simple least squares objective function with respect to the model parameters - presuming Gaussian, independent and homoscedastic errors (formal approach). Recent contributions to the (ecological) literature, however, have questioned the validity of this approach when confronted with significant errors and uncertainty in the model forcing (inputs) and model structure. Very often residual errors are non-Gaussian, correlated and heteroscedastic. Thus these error sources have to be considered and residual-errors have to be described in a statistically correct fashion order to draw statistically sound conclusions about parameter- and model predictive-uncertainties. We examined the effects of a generalized likelihood (GL) function on the parameter estimation of a carbon balance model. Compared with the formal approach, the GL function allows for correlation, non-stationarity and non-normality of model residuals. Carbon model parameters have been constrained using three different datasets, each of them modelled by its own GL function. As shown in literature the use of different datasets for parameter estimation reduces the uncertainty in model parameters and model predictions and does allow for a better quantification and for more insights into model processes.

  8. DETERMINATION ALGORITHM OF OPTIMAL GEOMETRICAL PARAMETERS FOR COMPONENTS OF FREIGHT CARS ON THE BASIS OF GENERALIZED MATHEMATICAL MODELS

    Directory of Open Access Journals (Sweden)

    O. V. Fomin

    2013-10-01

    Full Text Available Purpose. Presentation of features and example of the use of the offered determination algorithm of optimum geometrical parameters for the components of freight cars on the basis of the generalized mathematical models, which is realized using computer. Methodology. The developed approach to search for optimal geometrical parameters can be described as the determination of optimal decision of the selected set of possible variants. Findings. The presented application example of the offered algorithm proved its operation capacity and efficiency of use. Originality. The determination procedure of optimal geometrical parameters for freight car components on the basis of the generalized mathematical models was formalized in the paper. Practical value. Practical introduction of the research results for universal open cars allows one to reduce container of their design and accordingly to increase the carrying capacity almost by100 kg with the improvement of strength characteristics. Taking into account the mass of their park this will provide a considerable economic effect when producing and operating. The offered approach is oriented to the distribution of the software packages (for example Microsoft Excel, which are used by technical services of the most enterprises, and does not require additional capital investments (acquisitions of the specialized programs and proper technical staff training. This proves the correctness of the research direction. The offered algorithm can be used for the solution of other optimization tasks on the basis of the generalized mathematical models.

  9. A general model for estimation of daily global solar radiation using air temperatures and site geographic parameters in Southwest China

    Science.gov (United States)

    Li, Mao-Fen; Fan, Li; Liu, Hong-Bin; Guo, Peng-Tao; Wu, Wei

    2013-01-01

    Estimation of daily global solar radiation (Rs) from routinely measured temperature data has been widely developed and used in many different areas of the world. However, many of them are site specific. It is assumed that a general model for estimating daily Rs using temperature variables and geographical parameters could be achieved within a climatic region. This paper made an attempt to develop a general model to estimate daily Rs using routinely measured temperature data (maximum (Tmax, °C) and minimum (Tmin, °C) temperatures) and site geographical parameters (latitude (La, °N), longitude (Ld, °E) and altitude (Alt, m)) for Guizhou and Sichuan basin of southwest China, which was classified into the hot summer and cold winter climate zone. Comparison analysis was carried out through statistics indicators such as root mean squared error of percentage (RMSE%), modeling efficiency (ME), coefficient of residual mass (CRM) and mean bias error (MBE). Site-dependent daily Rs estimating models were calibrated and validated using long-term observed weather data. A general formula was then obtained from site geographical parameters and the better fit site-dependent models with mean RMSE% of 38.68%, mean MBE of 0.381 MJ m-2 d-1, mean CRM of 0.04 and mean ME value of 0.713.

  10. General analytical procedure for determination of acidity parameters of weak acids and bases.

    Science.gov (United States)

    Pilarski, Bogusław; Kaliszan, Roman; Wyrzykowski, Dariusz; Młodzianowski, Janusz; Balińska, Agata

    2015-01-01

    The paper presents a new convenient, inexpensive, and reagent-saving general methodology for the determination of pK a values for components of the mixture of diverse chemical classes weak organic acids and bases in water solution, without the need to separate individual analytes. The data obtained from simple pH-metric microtitrations are numerically processed into reliable pK a values for each component of the mixture. Excellent agreement has been obtained between the determined pK a values and the reference literature data for compounds studied.

  11. AN EPIDEMIOLOGICAL STUDY TO KNOW PREVALENCE OF HIV PATIENTS WITH STI CO-INFECTIONS IN OSMANIA GENERAL HOSPITAL FROM JUNE 2014-JULY 2015

    Directory of Open Access Journals (Sweden)

    Vijay Sekhar

    2015-10-01

    Full Text Available An Epidemiological study was conducted to know Prevalence of HIV patients with other STI co-infections in Osmania General Hospital from June 2014 - July 2015. A total of 339 HIV positive patients were selected and screened for other STIs with thorough clinical examination and with relevant investigations like STS, Serological tests for Hep-B, Hep-C and HSV. For patients with Genital ulcers, dark ground illumination (DGI, smear for multinucleated giant cells, Gram's stain, and Giemsa staining of tissue smears were done. In cases presenting with urethral discharge, KOH & Gram's stain were done. The findings were recorded in the STD case file. VAGINO-CERVICAL discharge was the most common STI in Females and HERPES GENITALIS was the most common STI in Males. Genital Molluscum was the least common STI in both sexes.

  12. Edge subdivision and edge multisubdivision versus some domination related parameters in generalized corona graphs

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    Magda Dettlaff

    2016-01-01

    Full Text Available Given a graph \\(G=(V,E\\, the subdivision of an edge \\(e=uv\\in E(G\\ means the substitution of the edge \\(e\\ by a vertex \\(x\\ and the new edges \\(ux\\ and \\(xv\\. The domination subdivision number of a graph \\(G\\ is the minimum number of edges of \\(G\\ which must be subdivided (where each edge can be subdivided at most once in order to increase the domination number. Also, the domination multisubdivision number of \\(G\\ is the minimum number of subdivisions which must be done in one edge such that the domination number increases. Moreover, the concepts of paired domination and independent domination subdivision (respectively multisubdivision numbers are defined similarly. In this paper we study the domination, paired domination and independent domination (subdivision and multisubdivision numbers of the generalized corona graphs.

  13. At risk, or not at risk: Epidemiological approaches for assessing psychiatric (genetic) risk factors in the general population

    NARCIS (Netherlands)

    Breetvelt, E.J.

    2013-01-01

    This thesis “At risk, or not at risk” describes several approaches - cross-sectional, prospective, phenotype mining and forward genetics - for assessing psychiatric (genetic) risk factors in a general population study. The aims were 1) to investigate how routine and follow-up data from populationbas

  14. General order parameter based correlation analysis of protein backbone motions between experimental NMR relaxation measurements and molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qing; Shi, Chaowei [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Yu, Lu [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); High Magnetic Field Laboratory, Chinese Academy of Science, Hefei, Anhui, 230031 (China); Zhang, Longhua [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Xiong, Ying, E-mail: yxiong73@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); Tian, Changlin, E-mail: cltian@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at The Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, 230026 (China); High Magnetic Field Laboratory, Chinese Academy of Science, Hefei, Anhui, 230031 (China)

    2015-02-13

    Internal backbone dynamic motions are essential for different protein functions and occur on a wide range of time scales, from femtoseconds to seconds. Molecular dynamic (MD) simulations and nuclear magnetic resonance (NMR) spin relaxation measurements are valuable tools to gain access to fast (nanosecond) internal motions. However, there exist few reports on correlation analysis between MD and NMR relaxation data. Here, backbone relaxation measurements of {sup 15}N-labeled SH3 (Src homology 3) domain proteins in aqueous buffer were used to generate general order parameters (S{sup 2}) using a model-free approach. Simultaneously, 80 ns MD simulations of SH3 domain proteins in a defined hydrated box at neutral pH were conducted and the general order parameters (S{sup 2}) were derived from the MD trajectory. Correlation analysis using the Gromos force field indicated that S{sup 2} values from NMR relaxation measurements and MD simulations were significantly different. MD simulations were performed on models with different charge states for three histidine residues, and with different water models, which were SPC (simple point charge) water model and SPC/E (extended simple point charge) water model. S{sup 2} parameters from MD simulations with charges for all three histidines and with the SPC/E water model correlated well with S{sup 2} calculated from the experimental NMR relaxation measurements, in a site-specific manner. - Highlights: • Correlation analysis between NMR relaxation measurements and MD simulations. • General order parameter (S{sup 2}) as common reference between the two methods. • Different protein dynamics with different Histidine charge states in neutral pH. • Different protein dynamics with different water models.

  15. The center for epidemiologic studies depression scale: support for a bifactor model with a dominant general factor and a specific factor for positive affect.

    Science.gov (United States)

    Gomez, Rapson; McLaren, Suzanne

    2015-06-01

    For the Center for Epidemiologic Studies Depression Scale (CES-D) ratings, the study examined support for a bifactor model, and also the internal consistency reliability and external validity of the factors in this model. Participants (N = 1,178) were older adults from the general community who completed the CES-D. Confirmatory factor analysis of their ratings indicated support for the bifactor model. For this model, the general factor explained most of the covariance in the scores of the CES-D items for Depressed Affect, Somatic Symptoms and Retarded Activity, and Interpersonal Difficulties items. Most of the covariance in the scores of the Positive Affect (PA) scale was explained by its own specific factor. Additional analyses showed support for internal consistencies and external validities of general factors based on all the CES-D items, and when PA items were excluded, and also the PA-specific factor. The findings support the use of a total CES-D score without the PA items and also the concurrent use of the PA scale score. © The Author(s) 2014.

  16. Evaluation of some laboratory parameters in patients with chronic generalized periodontitis associated with persistent herpesvirus infection

    Directory of Open Access Journals (Sweden)

    T. M. Volosovets

    2015-04-01

    Full Text Available Introduction. The nature of local pathogenetic mechanisms of periodontal tissue lesions is the result of the interaction of various etiopathogenetical determinants. The researchers almost do not consider influence of persistent herpes virus infection on the state of immunobiological organism resistance and deterioration of the overall prognosis of dental disease. Aim. To identify the features of laboratory parameters in 45 patients with periodontal pathology associated with herpes virus infection. Material and methods. Laboratory study of 45 people with periodontal pathology associated with herpes virus infection (group I, 20 individuals with periodontal pathology without concomitant herpes infection (group II and 10 individuals without periodontal pathology and without concomitant herpes viral infections (control group, namely: determining the amount of gingival fluid according to M. Barer et al. and determining therein the content of inflammatory mediators – histamine and serotonin according to B. Mykhailychenko, adsorption reaction of microorganisms was studied according to M. Danilevsky and T. Bilenchuk. Results. Amount of gingival fluid in persons of I and II groups had significant difference (p<0,05 between both among them and in comparison with the control group. The content of histamine and serotonin in the gingival fluid of individuals of I and II groups had significant difference (p<0,05 between them, it was also significantly (p<0,01 higher than the corresponding figures for patients of the control group. Indices of RAM-positive cells in patients of groups I and II were significantly lower (p<0,05 than in the control group. In addition, indices of group I were significantly lower (p <0,05 than in group II. Conclusions. Persistent herpes infection significantly affects the state of immunobiological organism resistance and worsens the overall prognosis of periodontal tissue pathology.

  17. Effect of Smoothing in Generalized Linear Mixed Models on the Estimation of Covariance Parameters for Longitudinal Data.

    Science.gov (United States)

    Mullah, Muhammad Abu Shadeque; Benedetti, Andrea

    2016-11-01

    Besides being mainly used for analyzing clustered or longitudinal data, generalized linear mixed models can also be used for smoothing via restricting changes in the fit at the knots in regression splines. The resulting models are usually called semiparametric mixed models (SPMMs). We investigate the effect of smoothing using SPMMs on the correlation and variance parameter estimates for serially correlated longitudinal normal, Poisson and binary data. Through simulations, we compare the performance of SPMMs to other simpler methods for estimating the nonlinear association such as fractional polynomials, and using a parametric nonlinear function. Simulation results suggest that, in general, the SPMMs recover the true curves very well and yield reasonable estimates of the correlation and variance parameters. However, for binary outcomes, SPMMs produce biased estimates of the variance parameters for high serially correlated data. We apply these methods to a dataset investigating the association between CD4 cell count and time since seroconversion for HIV infected men enrolled in the Multicenter AIDS Cohort Study.

  18. Epidemiology of gastroesophageal reflux disease:A general population-based study in Xi'an of Northwest China

    Institute of Scientific and Technical Information of China (English)

    Jin-Hai Wang; Jin-Yan Luo; Lei Dong; Jun Gong; Ming Tong

    2004-01-01

    AIM: Gastroesophageal reflux disease (GERD) is a common disorder in the Western population, but detailed populationbased data in China are limited. The aim of this study was to understand the epidemiology of symptomatic gastroesophageal reflux (SGER) in adults of Xi′an, a northwestern city of China,and to explore the potential risk factors of GERD.METHODS: Symptoms suggestive of GERD, functional dyspepsia (FD), irritable bowel syndrome (IBS), upper respiratory diseases and some potential risk factors were investigated in a face-to-face manner in a region-stratified random samples of 2 789 residents aged 18-70 years in Xi′an by using a standardized questionnaire.METHODS: With a response rate of 91.8%, the prevalence of SGER was 16.98% (95% CI, 14.2-18.92) in Xi′an adults,and no gender-related difference was observed (P<0.05).SGER was more common among subjects aged 30-70 years than in those aged 18-29 years (P<0.01). The prevalence of SGER in rural, urban and suburban subjects was 21.07%,17.44% and 12.12%, respectively, and there was a significant difference between rural, urban and suburban regions (P<0.05). Compared with subjects without SGER,the prevalence of symptoms suggestive of FD and IBS,pneumonia, asthma, bronchitis, laryngitis, pharyngitis,chronic cough, wheeze, globus sensation, oral ulcer and snore was significantly increased in subjects with SGER (P<0.01). Heavy smoking (OR=5.76; CI, 3.70-6.67), heavy alcohol use (OR=2.85; CI, 1.67-4.49), peptic ulcer (OR=5.76;CI, 3.99-8.32), cerebral palsy (OR=3.97; CI, 1.97-8.00),abdominal operation (OR=2.69; CI, 1.75-4.13), obesity (OR=2.16; CI, 1.47-3.16), excessive food intake (OR=1.43;CI, 1.17-1.15), sweet food (OR=1.23; CI, 0.89-1.54),and consumption of coffee (OR=1.23; CI, 0.17-2.00) were independently associated with SGER. The episodes of GERD were commonly precipitated by dietary factors (66.05%),followed by body posture (26.54%), iii temper (23.72%),fatigue (22.32%) and stress (10

  19. Epidemiological factors associated with ESBL- and non ESBL-producing E. coli causing urinary tract infection in general practice.

    Science.gov (United States)

    Hertz, Frederik Boëtius; Schønning, Kristian; Rasmussen, Steen Christian; Littauer, Pia; Knudsen, Jenny Dahl; Løbner-Olesen, Anders; Frimodt-Møller, Niels

    2016-01-01

    The purpose of the study was to evaluate how use of antibiotics precedes the presence of ESBL-producing E.coli in general practice. The authors performed a triple-case-control study where three case groups were individually compared to a single control group of uninfected individuals. Urine samples were prospectively collected and retrospective statistical analyses were done. This study included 98 cases with urinary tract infection (UTI) caused by ESBL-producing E. coli, 174 with antibiotic-resistant (non-ESBL) E. coli, 177 with susceptible E. coli and 200 with culture negative urine samples. Case groups had significantly higher use of antibiotics than the control group within 30 days before infection (p ESBL group had significantly more hospital admissions than the other case groups (p ESBL-producing E. coli. Exposure to antibiotics was a risk factor for UTI with E. coli, while prior antibiotic usage was not an indisputable predictor for infection with ESBL-producing E.coli in general practice.

  20. Robust Adaptive Sliding Mode Control for Generalized Function Projective Synchronization of Different Chaotic Systems with Unknown Parameters

    Directory of Open Access Journals (Sweden)

    Xiuchun Li

    2013-01-01

    Full Text Available When the parameters of both drive and response systems are all unknown, an adaptive sliding mode controller, strongly robust to exotic perturbations, is designed for realizing generalized function projective synchronization. Sliding mode surface is given and the controlled system is asymptotically stable on this surface with the passage of time. Based on the adaptation laws and Lyapunov stability theory, an adaptive sliding controller is designed to ensure the occurrence of the sliding motion. Finally, numerical simulations are presented to verify the effectiveness and robustness of the proposed method even when both drive and response systems are perturbed with external disturbances.

  1. The epidemiological profile of pediatric patients admitted to the general intensive care unit in an Ethiopian university hospital

    Directory of Open Access Journals (Sweden)

    Abebe T

    2015-01-01

    Full Text Available Teshome Abebe, Mullu Girmay, Girma G/Michael, Million Tesfaye Department of Anesthesia, Jimma University, Jimma, Ethiopia Background: In least developing countries, there are few data on children's critical care. This makes the provision of aid and improvement of outcome difficult. Objectives: To describe admission and outcome patterns of children managed in a general intensive care unit at Jimma University Specialized Hospital (JUSH, Ethiopia, over a 5-year period. Methods: A retrospective cross-sectional study design was used. All children from birth to 14 years of age who were admitted to the general ICU of the hospital from 2009–2013 were included. Patient charts and ICU documentation log were reviewed. Results: A total of 170 children were admitted to the ICU of JUSH over the study period. The greater share was taken by males (54.7%, with a male-to-female ratio of 1.2:1. The overall mortality rate was 40%. The majority of the children were in the age range of 10–14 years (38.8%. Of the total number of patients admitted, 34.7% were trauma cases, 45.8% of whom died. The highest percentage, 69.5%, of trauma patients were admitted for head injuries. Among the trauma cases, burn and polytrauma were the second and third leading causes (15.3% of admission. Postoperative patients and medical patients accounted for the rest of the admitted cases (28.2% and 27.6% of the cases respectively. Conclusion: The leading cause of admission and death was trauma. Postoperative and medical causes of admission were also significant. The mortality rate in the ICU was very high, and this could be due to various factors. Further research benchmarking and interventions are highly recommended. Keywords: trauma, critical care, pediatric, ICU, ventilation, oxygenation

  2. Image Denoising via Bayesian Estimation of Statistical Parameter Using Generalized Gamma Density Prior in Gaussian Noise Model

    Science.gov (United States)

    Kittisuwan, Pichid

    2015-03-01

    The application of image processing in industry has shown remarkable success over the last decade, for example, in security and telecommunication systems. The denoising of natural image corrupted by Gaussian noise is a classical problem in image processing. So, image denoising is an indispensable step during image processing. This paper is concerned with dual-tree complex wavelet-based image denoising using Bayesian techniques. One of the cruxes of the Bayesian image denoising algorithms is to estimate the statistical parameter of the image. Here, we employ maximum a posteriori (MAP) estimation to calculate local observed variance with generalized Gamma density prior for local observed variance and Laplacian or Gaussian distribution for noisy wavelet coefficients. Evidently, our selection of prior distribution is motivated by efficient and flexible properties of generalized Gamma density. The experimental results show that the proposed method yields good denoising results.

  3. Deriving amplification factors from simple site parameters using generalized regression neural networks: implications for relevant site proxies

    Science.gov (United States)

    Boudghene Stambouli, Ahmed; Zendagui, Djawad; Bard, Pierre-Yves; Derras, Boumédiène

    2017-07-01

    Most modern seismic codes account for site effects using an amplification factor (AF) that modifies the rock acceleration response spectra in relation to a "site condition proxy," i.e., a parameter related to the velocity profile at the site under consideration. Therefore, for practical purposes, it is interesting to identify the site parameters that best control the frequency-dependent shape of the AF. The goal of the present study is to provide a quantitative assessment of the performance of various site condition proxies to predict the main AF features, including the often used short- and mid-period amplification factors, Fa and Fv, proposed by Borcherdt (in Earthq Spectra 10:617-653, 1994). In this context, the linear, viscoelastic responses of a set of 858 actual soil columns from Japan, the USA, and Europe are computed for a set of 14 real accelerograms with varying frequency contents. The correlation between the corresponding site-specific average amplification factors and several site proxies (considered alone or as multiple combinations) is analyzed using the generalized regression neural network (GRNN). The performance of each site proxy combination is assessed through the variance reduction with respect to the initial amplification factor variability of the 858 profiles. Both the whole period range and specific short- and mid-period ranges associated with the Borcherdt factors Fa and Fv are considered. The actual amplification factor of an arbitrary soil profile is found to be satisfactorily approximated with a limited number of site proxies (4-6). As the usual code practice implies a lower number of site proxies (generally one, sometimes two), a sensitivity analysis is conducted to identify the "best performing" site parameters. The best one is the overall velocity contrast between underlying bedrock and minimum velocity in the soil column. Because these are the most difficult and expensive parameters to measure, especially for thick deposits, other

  4. Hepatitis B virus infections and risk factors among the general population in Anhui Province, China: an epidemiological study

    Directory of Open Access Journals (Sweden)

    Li Xiaoqing

    2012-04-01

    Full Text Available Abstract Background Hepatitis B is one of the most common infectious diseases in China. The aim of this study was to determine the prevalence of hepatitis B surface antigen (HBsAg among the general population and the risk factors associated with HBV infection in Anhui province, China. Methods A provincial serosurvey was conducted in four cities, and selected through stratified clustering sampling. Data on demographics, immunization history, medical history, family medical history, and life history were collected, along with serum tested for HBsAg. Completed surveys were analysed from 8,875 participants. Results Overall prevalence of HBsAg was 7.44%. Using multivariate analysis, older age was a risk factor for HBsAg infection among children younger than 15 years. Among adults 15-59 years old, the risk factors were male gender, a history of surgical operations, at least one HBsAg-positive family member, and non-vaccination. For adults older than 59 years, the risk factor was a blood transfusion history. Conclusions Though Anhui province has already reached the national goal of reducing HBsAg prevalence to less than 1% among children younger than 5 years, there are still several risk factors for HBsAg infection among the older population. Immunization programs should continue to focus on adults, and interventions should be taken to reduce risk factors associated with being infected with Hepatitis B.

  5. Admission of foreign citizens to the general teaching hospital of bologna, northeastern Italy: An epidemiological and clinical survey

    Directory of Open Access Journals (Sweden)

    Sergio Sabbatani

    2006-04-01

    Full Text Available BACKGROUND: The emergency regarding recent immigration waves into Italy makes continued healthcare monitoring of these populations necessary. METHODS: Through a survey of hospital admissions carried out during the last five years at the S. Orsola-Malpighi General Hospital of Bologna (Italy, all causes of admission of these subjects were evaluated, together with their correlates. Subsequently, we focused on admissions due to infectious diseases. All available data regarding foreign citizens admitted as inpatients or in Day-Hospital settings of our teaching hospital from January 1, 1999, to March 31, 2004, were assessed. Diagnosis-related group (DRG features, and single discharge diagnoses, were also evaluated, and a further assessment of infectious diseases was subsequently made. RESULTS: Within a comprehensive pool of 339,051 hospitalized patients, foreign citizen discharges numbered 7,312 (2.15%, including 2,542 males (34.8% and 4,769 females (65.2%. Males had a mean age of 36.8±14.7 years, while females were aged 30.8±12.2 years. In the assessment of the areas of origin, 34.6% of hospitalizations were attributed to patients coming from Eastern Europe, 15.3% from Northern Africa, 7.3% (comprehensively from Western Europe and United States, 6.9% from the Indian subcontinent, 5.9% from sub-Saharan Africa, 5.7% from Latin America, 4.1% from China, 2.5% from the Philippines, and 1.1% from the Middle East. Among women, most hospitalizations (58.8% were due to obstetrical-gynecological procedures or diseases, including assistance with delivery (27.1%, and pregnancy complications (18.7%, followed by psycho-social disturbances (5.9%, malignancies (5.1%, gastrointestinal diseases (4.7%, and voluntary pregnancy interruption (4.4%. Among men, the most frequent causes of admissions were related to trauma (15.9%, followed by gastroenteric disorders (12%, heart-vascular diseases (8.9%, psycho-social disorders (8.4%, respiratory (7.1%, kidney (6.1%, liver

  6. Admission of foreign citizens to the general teaching hospital of bologna, northeastern Italy: An epidemiological and clinical survey

    Directory of Open Access Journals (Sweden)

    Sergio Sabbatani

    Full Text Available BACKGROUND: The emergency regarding recent immigration waves into Italy makes continued healthcare monitoring of these populations necessary. METHODS: Through a survey of hospital admissions carried out during the last five years at the S. Orsola-Malpighi General Hospital of Bologna (Italy, all causes of admission of these subjects were evaluated, together with their correlates. Subsequently, we focused on admissions due to infectious diseases. All available data regarding foreign citizens admitted as inpatients or in Day-Hospital settings of our teaching hospital from January 1, 1999, to March 31, 2004, were assessed. Diagnosis-related group (DRG features, and single discharge diagnoses, were also evaluated, and a further assessment of infectious diseases was subsequently made. RESULTS: Within a comprehensive pool of 339,051 hospitalized patients, foreign citizen discharges numbered 7,312 (2.15%, including 2,542 males (34.8% and 4,769 females (65.2%. Males had a mean age of 36.8±14.7 years, while females were aged 30.8±12.2 years. In the assessment of the areas of origin, 34.6% of hospitalizations were attributed to patients coming from Eastern Europe, 15.3% from Northern Africa, 7.3% (comprehensively from Western Europe and United States, 6.9% from the Indian subcontinent, 5.9% from sub-Saharan Africa, 5.7% from Latin America, 4.1% from China, 2.5% from the Philippines, and 1.1% from the Middle East. Among women, most hospitalizations (58.8% were due to obstetrical-gynecological procedures or diseases, including assistance with delivery (27.1%, and pregnancy complications (18.7%, followed by psycho-social disturbances (5.9%, malignancies (5.1%, gastrointestinal diseases (4.7%, and voluntary pregnancy interruption (4.4%. Among men, the most frequent causes of admissions were related to trauma (15.9%, followed by gastroenteric disorders (12%, heart-vascular diseases (8.9%, psycho-social disorders (8.4%, respiratory (7.1%, kidney (6.1%, liver

  7. Epidemiology of Suicide and Associated Socio-Demographic Factors in Emergency Department Patients in 7 General Hospitals in Northwestern China.

    Science.gov (United States)

    Zhao, Cheng-jin; Dang, Xing-bo; Su, Xiao-li; Bai, Jia; Ma, Long-yang

    2015-09-15

    This study aimed to illustrate the characteristics of suicide attempters treated in the Emergency Departments of 7 general hospitals in Xi'an and to provide relevant data for early psychological treatment. Between October 2010 and September 2014, 155 suicide attempters were treated in the Emergency Departments. Data were collected using a semi-structured questionnaire. Descriptive statistics, chi-square tests, and multivariate analyses were used to identify the factors associated with suicidal behaviors. Females outnumbered males at a ratio of 3.7 to 1. The greatest proportion of cases was in the age group of 21 to 30 years (52.9%). Patients who finished middle school or high school accounted for most of the suicide attempters (50.3%). The most common method used for attempted suicide was drug ingestion (86.5%). The majority of cases attempted suicide at home (74.8%) during the night. Marriage frustration, work and study problems, family fanaticism and conflict, somatic disease, and history of mental disorders were all significantly associated with suicide attempts. The ratio of patients to be discharged or to die were similar in occupation, marital status, and the place of suicide attempt; however, the results were different in gender, age, educational level, methods used for suicide, time of day, and reason. Suicide is an important public health problem and is multidimensional in nature. Future studies with larger samples are expected to provide more specific knowledge of the effect of each social factor on the suicide risk in Chinese in order to improve the prevention of suicides.

  8. Epidemiology of multimorbidity within the Brazilian adult general population: Evidence from the 2013 National Health Survey (PNS 2013)

    Science.gov (United States)

    de Azevedo-Marques, João Mazzoncini; Coxon, Domenica; Santos, Jair Lício Ferreira

    2017-01-01

    Middle-income countries are facing a growing challenge of adequate health care provision for people with multimorbidity. The objectives of this study were to explore the distribution of multimorbidity and to identify patterns of multimorbidity in the Brazilian general adult population. Data from 60202 adults, aged ≥18 years that completed the individual questionnaire of the National Health Survey 2013 (Portuguese: “Pesquisa Nacional de Saúde”–“PNS”) was used. We defined multimorbidity as the presence of two or more chronic conditions, including self-reported diagnoses and responses to the 9-item Patient Health Questionnaire for depression. Multivariate Poisson regression analyses were used to explore relationship between multimorbidity and demographic factors. Exploratory tetrachoric factor analysis was performed to identify multimorbidity patterns. 24.2% (95% CI 23.5–24.9) of the study population were multimorbid, with prevalence rate ratios being significantly higher in women, older people and those with lowest educational level. Multimorbidity occurred earlier in women than in men, with half of the women and men aged 55–59 years and 65–69 years, respectively, were multimorbid. The absolute number of people with multimorbidity was approximately 2.5-fold higher in people younger than 65 years than older counterparts (9920 vs 3945). Prevalence rate ratios of any mental health disorder significantly increased with the number of physical conditions. 46.7% of the persons were assigned to at least one of three identified patterns of multimorbidity, including: “cardio-metabolic”, “musculoskeletal-mental” and “respiratory” disorders. Multimorbidity in Brazil is as common as in more affluent countries. Women in Brazil develop diseases at younger ages than men. Our findings can inform a national action plan to prevent multimorbidity, reduce its burden and align health-care services more closely with patients’ needs. PMID:28182778

  9. Seismic source parameters of the induced seismicity at The Geysers geothermal area, California, by a generalized inversion approach

    Science.gov (United States)

    Picozzi, Matteo; Oth, Adrien; Parolai, Stefano; Bindi, Dino; De Landro, Grazia; Amoroso, Ortensia

    2017-04-01

    The accurate determination of stress drop, seismic efficiency and how source parameters scale with earthquake size is an important for seismic hazard assessment of induced seismicity. We propose an improved non-parametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for the attenuation and site contributions. Then, the retrieved source spectra are inverted by a non-linear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (ML 2-4.5) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations of the Lawrence Berkeley National Laboratory Geysers/Calpine surface seismic network, more than 17.000 velocity records). We find for most of the events a non-selfsimilar behavior, empirical source spectra that requires ωγ source model with γ > 2 to be well fitted and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes, and that the proportion of high frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with the earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that, in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping fault in the fluid pressure diffusion.

  10. Epidemiological Profile of Hepatitis B Virus Infection in Iran in the Past 25 years; A Systematic Review and Meta-analysis of General Population Studies.

    Science.gov (United States)

    Mohammadi, Zahra; Keshtkar, Abbasali; Eghtesad, Sareh; Jeddian, Alireza; Pourfatholah, Ali Akbar; Maghsudlu, Mahtab; Zadsar, Maryam; Mahmoudi, Zahra; Shayanrad, Amaneh; Poustchi, Hossein; Malekzadeh, Reza

    2016-01-01

    BACKGROUND Chronic hepatitis B virus (HBV) infection is one of the most important health problems worldwide with a high rate of morbidity and mortality. It is a major risk factor for cirrhosis and liver cancer. Currently, Iran is located in the intermediate HBV zone; however, recent studies have provided some evidence indicating an epidemiological change in the country. The aim of this study was to estimate the prevalence of HBV in Iran. METHODS A systematic review was conducted to evaluate the studies performed in the past 25 years that have reported the prevalence of HBV infection and its associated factors in the Iranian general population (1990-2014). Any study assessing and reporting serum Hbs Ag levels was included in this review. RESULTS After excluding all impertinent studies, 19 eligible studies were included in the analysis. The overall prevalence of HBV was 3% (95% CI 2% to 3%). Its distribution showed that the prevalence of HBV varies in different provinces from 0.87% to 8.86%. The HBV rate was highest in the Golestan (8.86%) and lowest in the Kurdistan (0.87%) provinces. CONCLUSION This study provides some evidence about the prevalence of HBV in Iran. However, the collected data was very heterogenic, even within a single province, which made it hard to estimate a single-point prevalence. High quality studies are needed to find reliable information about HBV prevalence and to decrease the heterogeneity of results in the country.

  11. Epidemiology of general obesity, abdominal obesity and related risk factors in urban adults from 33 communities of Northeast China: the CHPSNE study.

    Science.gov (United States)

    Wang, Hao; Wang, Jing; Liu, Miao-Miao; Wang, Da; Liu, Yu-Qin; Zhao, Yang; Huang, Mei-Meng; Liu, Yang; Sun, Jing; Dong, Guang-Hui

    2012-11-12

    Obesity increases the risk of many diseases. However, there has been little literature about the epidemiology of obesity classified by body mass index (BMI) or waist (abdominal obesity) among urban Chinese adults. This study is to fill the gap by assessing the prevalence of obesity and associated risk factors among urban Chinese adults. A representative sample of 25,196 urban adults aged 18 to 74 years in Northeast China was selected and measurements of height, weight and waist circumference (WC) were taken from 2009-2010. Definitions of overweight and obesity by the World Health Organization (WHO) were used. The overall prevalence rates of general obesity and overweight classified by BMI were 15.0% (15.7% for men and 14.3% for women, pobesity was 37.6% (31.1% for men and women 43.9% for women, pobesity, alcohol drinking, or former cigarette smoking were at high risk of obesity classified by BMI or WC, whereas those with a higher level of education, higher family income, or a healthy and balanced diet were at low risk of obesity. Analysis stratified by gender showed that men with a higher level education level, a white-collar job, a cadre job, or higher family income were the high risk group, and women with a higher level of education or higher family income were the low risk group. Obesity and overweight have become epidemic in urban populations in China; associations of risk factors with obesity differ between men and women.

  12. Parasuicide and drug self-poisoning: analysis of the epidemiological and clinical variables of the patients admitted to the Poisoning Treatment Centre (CAV, Niguarda General Hospital, Milan

    Directory of Open Access Journals (Sweden)

    Manfré Sergio

    2005-04-01

    Full Text Available Abstract Epidemiological knowledge of parasuicides and drug self-poisoning is still limited by a lack of data. A number of preliminary studies, which require further analysis, evidenced that parasuicidal acts occur more often among females, that the peak rate is generally recorded between the ages of 15 and 34 years and psychotropic medications seems to be the most frequently used. The aim of this study was to describe the demographic and clinical variables of a sample of subjects admitted to the Posisoning Treatment Centre (CAV, Niguarda General Hospital, Milan, following drug self-poisoning. Furthermore, this study is aimed to identify the risk factors associated to parasuicidal gestures, with special care for the used drugs, the presence of psychiatric or organic disorders, alcoholism and drug addiction. The study included the 201 patients attending the CAV in 1999 and 2000 who satisfied the criteria of self-poisoning attempts: 106 cases in 1999 and 95 in 2000. The sample had a prevalence of females (64%. The peak rates of parasuicides from drug self-poisoning were reached between 21 and 30 years among the females, and 31 and 40 years among the males. 81.6% of the patients used one or more psychoactive drugs, the most frequent being the benzodiazepines (58.7%, classic neuroleptics (16.9% and new-generation antidepressants (SSRIs, SNRIs, NARIs (12.9%. The prevalence of mood disorders was higher among females (64% vs 42%, whereas schizophrenia was more frequently diagnosed in males (22% vs 10%. 61% (33% had a history of previous attempted suicides. The presence of clinically relevant organic diseases was observed in 24.9% of the sample.

  13. A general theory of secondary recrystallization in grain oriented Fe-Si: Metallurgical parameters controlling the microstructural evolution

    Science.gov (United States)

    Abbruzzese, G.; Campopiano, A.

    1994-05-01

    The secondary recrystallization (SR) process and the related effects on the magnetic properties of silicon-iron are discussed in the framework of the general statistical theory of grain growth including texture and Zener drag influence. It has been shown that SR in silicon-iron is related to a selective growth process experienced by Goss grains due to specific grain boundary conditions generated by the surrounding grains (texture). In this paper some examples showing the specific role of various microstructural parameters influencing the selectivity of SR (such as Zener drag intensity and its drop rate, initial grain size, etc.), are discussed and related to the magnetic properties, which are mainly controlled by the final average grain size and orientation.

  14. Epidemiology: Then and Now.

    Science.gov (United States)

    Kuller, Lewis H

    2016-03-01

    Twenty-five years ago, on the 75th anniversary of the Johns Hopkins Bloomberg School of Public Health, I noted that epidemiologic research was moving away from the traditional approaches used to investigate "epidemics" and their close relationship with preventive medicine. Twenty-five years later, the role of epidemiology as an important contribution to human population research, preventive medicine, and public health is under substantial pressure because of the emphasis on "big data," phenomenology, and personalized medical therapies. Epidemiology is the study of epidemics. The primary role of epidemiology is to identify the epidemics and parameters of interest of host, agent, and environment and to generate and test hypotheses in search of causal pathways. Almost all diseases have a specific distribution in relation to time, place, and person and specific "causes" with high effect sizes. Epidemiology then uses such information to develop interventions and test (through clinical trials and natural experiments) their efficacy and effectiveness. Epidemiology is dependent on new technologies to evaluate improved measurements of host (genomics), epigenetics, identification of agents (metabolomics, proteomics), new technology to evaluate both physical and social environment, and modern methods of data collection. Epidemiology does poorly in studying anything other than epidemics and collections of numerators and denominators without specific hypotheses even with improved statistical methodologies.

  15. A general framework for a reliable multivariate analysis and pattern recognition in high-dimensional epidemiological data, based on cluster robustness: a tutorial to enrich the epidemiologists' toolkit.

    Science.gov (United States)

    Lefèvre, T; Chauvin, P

    2015-02-01

    In an epidemiologist's toolbox, three main types of statistical tools can be found: means and proportions comparisons, linear or logistic regression models and Cox-type regression models. All these techniques have their own multivariate formulations, so that biases can be accounted for. Nonetheless, there is an entire set of natively massive multivariate techniques, which are based on weaker assumptions than classical statistical techniques are, and which seem to be underestimated or remain unknown to most epidemiologists. These techniques are used for pattern recognition or clustering – that is, for retrieving homogeneous groups in data without any a priori about these groups. They are widely used in connex domains such as genetics or biomolecular studies. Most clustering techniques require tuning specific parameters so that groups can be identified in data. A critical parameter to set is the number of groups the technique needs to discover. Different approaches to find the optimal number of groups are available, such as the silhouette approach and the robustness approach. This article presents the key aspects of clustering techniques (how proximity between observations is defined and how to find the number of groups), two archetypal techniques (namely the k-means and PAM algorithms) and how they relate to more classical statistical approaches. Through a theoretical, simple example and a real data application, we provide a complete framework within which classical epidemiological concerns can be reconsidered. We show how to (i) identify whether distinct groups exist in data, (ii) identify the optimal number of groups in data, (iii) label each observation according to its own group and (iv) analyze the groups identified according to separate and explicative data. In addition, how to achieve consistent results while removing sensitivity to initial conditions is explained. Clustering techniques, in conjunction with methods for parameter tuning, provide the

  16. Role of the parameters involved in the plan optimization based on the generalized equivalent uniform dose and radiobiological implications

    Science.gov (United States)

    Widesott, L.; Strigari, L.; Pressello, M. C.; Benassi, M.; Landoni, V.

    2008-03-01

    We investigated the role and the weight of the parameters involved in the intensity modulated radiation therapy (IMRT) optimization based on the generalized equivalent uniform dose (gEUD) method, for prostate and head-and-neck plans. We systematically varied the parameters (gEUDmax and weight) involved in the gEUD-based optimization of rectal wall and parotid glands. We found that the proper value of weight factor, still guaranteeing planning treatment volumes coverage, produced similar organs at risks dose-volume (DV) histograms for different gEUDmax with fixed a = 1. Most of all, we formulated a simple relation that links the reference gEUDmax and the associated weight factor. As secondary objective, we evaluated plans obtained with the gEUD-based optimization and ones based on DV criteria, using the normal tissue complication probability (NTCP) models. gEUD criteria seemed to improve sparing of rectum and parotid glands with respect to DV-based optimization: the mean dose, the V40 and V50 values to the rectal wall were decreased of about 10%, the mean dose to parotids decreased of about 20-30%. But more than the OARs sparing, we underlined the halving of the OARs optimization time with the implementation of the gEUD-based cost function. Using NTCP models we enhanced differences between the two optimization criteria for parotid glands, but no for rectum wall.

  17. Multiband Gravitational-Wave Astronomy: Parameter Estimation and Tests of General Relativity with Space- and Ground-Based Detectors

    Science.gov (United States)

    Vitale, Salvatore

    2016-07-01

    With the discovery of the binary-black-hole (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the Evolved Laser Interferometer Space Antenna (eLISA) band a few years before they finally merge in the band of ground-based detectors. This would allow for premerger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBHs are indeed luminous in the electromagnetic band. In this Letter we explore a quite different aspect of multiband GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBHs and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA will not be refined by the ground based detectors, whereas joint analysis will yield precise characterization of the newly formed black hole and improve consistency tests of general relativity.

  18. Multiband Gravitational-Wave Astronomy: Parameter Estimation and Tests of General Relativity with Space- and Ground-Based Detectors.

    Science.gov (United States)

    Vitale, Salvatore

    2016-07-29

    With the discovery of the binary-black-hole (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the Evolved Laser Interferometer Space Antenna (eLISA) band a few years before they finally merge in the band of ground-based detectors. This would allow for premerger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBHs are indeed luminous in the electromagnetic band. In this Letter we explore a quite different aspect of multiband GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBHs and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA will not be refined by the ground based detectors, whereas joint analysis will yield precise characterization of the newly formed black hole and improve consistency tests of general relativity.

  19. Use of replacement blood donors to study the epidemiology of major blood-borne viruses in the general population of Maputo, Mozambique.

    Science.gov (United States)

    Cunha, Lina; Plouzeau, Chloé; Ingrand, Pierre; Gudo, Joël Paulo Samo; Ingrand, Isabelle; Mondlane, José; Beauchant, Michel; Agius, Gérard

    2007-12-01

    The seroprevalence rates of human immunodeficiency virus (HIV), human T-cell leukemia/lymphoma virus (HTLV), hepatitis B virus (HBV), hepatitis D virus (HDV), and hepatitis C virus (HCV) in Mozambique are poorly documented. The epidemiology of these infections was studied in the Maputo region. All donors attending the blood bank during the study period were interviewed and underwent serological and molecular tests for markers of virus exposure. Thus, 1,578 consecutive replacement blood donors were investigated, as they undergo no selection (other than their relation with a patient needing a transfusion), and may thus provide reliable estimates of the prevalence rates in the general population. The age-standardized prevalence rates among 15- to 49-year-old men and women were, respectively, 12.3 and 15.4% for HIV and 0.9 and 1.2% for HTLV. Low educational status (P = 0.014) and tattooing/scarification (P = 0.023) were predictive of HIV infection in multivariate analysis. The age-adjusted prevalence rates of markers of hepatotropic virus among men and women were, respectively, 10.6 and 4.5% for hepatitis B surface antigen (HBsAg), 1.2 and 1.0% for anti-HCV, and 0 and 0% for anti-HDV. Two percent of donors had viral co-infections, involving most frequently the combination of HIV and HBsAg +. A significant association was found between anti-HIV and anti-HBc (P = 0.012). HBsAg was associated with the place of birth (P = 0.011) and a history of transfusion (P = 0.069). Smokers had higher seroprevalence rates than nonsmokers for HIV (P Mozambique. (c) Wiley-Liss, Inc.

  20. Effect of Preload Alterations on Left Ventricular Systolic Parameters Including Speckle-Tracking Echocardiography Radial Strain During General Anesthesia.

    Science.gov (United States)

    Weber, Ulrike; Base, Eva; Ristl, Robin; Mora, Bruno

    2015-08-01

    Frequently used parameters for evaluation of left ventricular systolic function are load-sensitive. However, the impact of preload alterations on speckle-tracking echocardiographic parameters during anesthesia has not been validated. Therefore, two-dimensional (2D) speckle-tracking echocardiography radial strain (RS) was assessed during general anesthesia, simulating 3 different preload conditions. Single-center prospective observational study. University hospital. Thirty-three patients with normal left ventricular systolic function undergoing major surgery. Transgastric views of the midpapillary level of the left ventricle were acquired at 3 different positions. Fractional shortening (FS), fractional area change (FAC), and 2D speckle-tracking echocardiography RS were analyzed in the transgastric midpapillary view. Considerable correlation above 0.5 was found for FAC and FS in the zero and Trendelenburg positions (r = 0.629, r = 0.587), and for RS and FAC in the anti-Trendelenburg position (r = 0.518). In the repeated-measures analysis, significant differences among the values measured at the 3 positions were found for FAC and FS. For FAC, there were differences up to 2.8 percentage points between the anti-Trendelenburg position and the other 2 positions. For FS, only the difference between position zero and anti-Trendelenburg was significant, with an observed change of 1.66. Two-dimensional RS was not significantly different at all positions, with observed changes below 1 percentage point. Alterations in preload did not result in clinically relevant changes of RS, FS, or FAC. Observed changes for RS were smallest; however, the variation of RS was larger than that of FS or FAC. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. New approach to assess bioequivalence parameters using generalized gamma mixed-effect model (model-based asymptotic bioequivalence test).

    Science.gov (United States)

    Chen, Yuh-Ing; Huang, Chi-Shen

    2014-02-28

    In the pharmacokinetic (PK) study under a 2x2 crossover design that involves both the test and reference drugs, we propose a mixed-effects model for the drug concentration-time profiles obtained from subjects who receive different drugs at different periods. In the proposed model, the drug concentrations repeatedly measured from the same subject at different time points are distributed according to a multivariate generalized gamma distribution, and the drug concentration-time profiles are described by a compartmental PK model with between-subject and within-subject variations. We then suggest a bioequivalence test based on the estimated bioavailability parameters in the proposed mixed-effects model. The results of a Monte Carlo study further show that the proposed model-based bioequivalence test is not only better on maintaining its level but also more powerful for detecting the bioequivalence of the two drugs than the conventional bioequivalence test based on a non-compartmental analysis or the one based on a mixed-effects model with a normal error variable. The application of the proposed model and test is finally illustrated by using data sets in two PK studies.

  2. A twelve year follow-up study on osteoarthritis of the knee in the general population : an epidemiological study of classification criteria, risk factors and prognostic factors

    NARCIS (Netherlands)

    J.S.A.G. Schouten (Jan S.A.G.)

    1991-01-01

    textabstractCriteria to diagnose the disease or assess the outcome need to be considered in every epidemiological study . The criteria are needed to classify participants as those having the disease or outcome and those who have not. Classification criteria are not always uniformly accepted and comm

  3. [Normal values of temporal parameters of ECG in children according to results of clinico-epidemiological study ECG-screening of children and adolescents in Russian federation].

    Science.gov (United States)

    Miklashevich, I M; Shkol'nikova, M A; Kalinin, L A; Abdullatipova, I V; Osokina, G G; Deev, A D; Blinova, A V; Drozdova, A I; Lebed'kova, S E; Muratov, R A; Verevkina, O N; Timukova, A K; Lunegova, E V; Kozlova, L V; Svintsova, L I; Khomiakova, O I; Ashcheulova, N L

    2009-01-01

    In order to obtain reliable information about time-domain ECG parameters in Russian children and to analyse their links with physiological changes the Project "ECG screening of children and adolescents of the Russian Federation" was carried out in 2003-2008. Time domain ECG parameters were studied in the representative sample of 5387 healthy individuals aged 0 to 18 years. In each age group, lower and upper limits of the norm for heart rate (HR), P wave, PQ and QRS intervals were defined as 2nd and 98th percentiles of their distribution. The equivalent limits of QT interval duration were defined as its 5th and 95th percentiles. Relationship between time domain parameters of pediatric ECG and HR was analyzed as well as relationship of these parameters with sex and age. The most important differences from prior pediatric studies completed 30 years ago were obtained for the heart rate limits. Among children aged 0 to 3, there was a tendency toward lowering of age-specific lower limits and elevation of age-specific upper limits. At ages older than 3 years, there was a tendency toward lowering of both the upper and the lower limits of HR. The newly obtained 2nd percentiles of the heart rate were lower than the known lower limits in nearly all ages. This indicates the necessity for revision of criteria of bradicardia in children. The present study showed that 5th and 95th percentiles of QTc interval (Bazett's formula) varied between 340 ms and 465 ms and were not significantly dependent on children's age and only for ages under 13 also on sex. Results of the study allowed to build age-specific ranges of norm for the time domain ECG parameters presented in a tabular form.

  4. Typing of the pilus-protein-encoding FCT region and biofilm formation as novel parameters in epidemiological investigations of Streptococcus pyogenes isolates from various infection sites.

    Science.gov (United States)

    Köller, Thomas; Manetti, Andrea Guido Oreste; Kreikemeyer, Bernd; Lembke, Cordula; Margarit, Immaculada; Grandi, Guido; Podbielski, Andreas

    2010-04-01

    Streptococcus pyogenes is an important human pathogen for which an association between infection site and selected epidemiological or functional markers has previously been suggested. However, the studies involved often used strains with an insufficiently defined clinical background and laboratory history. Thus, the major goal of the present study was to investigate these relationships in 183 prospectively collected, well-defined, low-passage isolates from a North-East German centre for tertiary care. For each isolate the clinical background (91 respiratory, 71 skin and 21 invasive isolates) and antibiotic-resistance pattern was recorded. All isolates were classified according to their emm type, antibiotic-resistance and PFGE pattern ( SmaI restriction analysis of genomic DNA). As novel discriminatory methods we performed a PCR-based typing of the pilus-protein-encoding FCT region (FCT) and biofilm-formation phenotyping in various culture media. Forty-one isolates were found to be resistant to at least one of the tested antibiotics. emm typing revealed emm28, emm12 , emm1, emm4, emm89 and emm2 as the most frequent types in our collection. The novel FCT typing showed isolates encoding FCT types 4 and 2 to be the most common. Overall 113 strains with unique combinations of emm and FCT types, antibiotic-resistance and PFGE patterns were identified. The majority of all isolates revealed an association of biofilm-formation capacity with growth media. Comparing all results for potential associations, no correlation could be established between the anatomical site of isolation and the emm or the FCT type. There was no relationship between biofilm formation and emm type, antibiotic-resistance or PFGE patterns. However, a novel association between biofilm formation and FCT type became obvious among strains from our collection.

  5. Epidemiological causality.

    Science.gov (United States)

    Morabia, Alfredo

    2005-01-01

    Epidemiological methods, which combine population thinking and group comparisons, can primarily identify causes of disease in populations. There is therefore a tension between our intuitive notion of a cause, which we want to be deterministic and invariant at the individual level, and the epidemiological notion of causes, which are invariant only at the population level. Epidemiologists have given heretofore a pragmatic solution to this tension. Causal inference in epidemiology consists in checking the logical coherence of a causality statement and determining whether what has been found grossly contradicts what we think we already know: how strong is the association? Is there a dose-response relationship? Does the cause precede the effect? Is the effect biologically plausible? Etc. This approach to causal inference can be traced back to the English philosophers David Hume and John Stuart Mill. On the other hand, the mode of establishing causality, devised by Jakob Henle and Robert Koch, which has been fruitful in bacteriology, requires that in every instance the effect invariably follows the cause (e.g., inoculation of Koch bacillus and tuberculosis). This is incompatible with epidemiological causality which has to deal with probabilistic effects (e.g., smoking and lung cancer), and is therefore invariant only for the population.

  6. Gradient Theory simulations of pure fluid interfaces using a generalized expression for influence parameters and a Helmholtz energy equation of state for fundamentally consistent two-phase calculations.

    Science.gov (United States)

    Dahms, Rainer N

    2015-05-01

    The fidelity of Gradient Theory simulations depends on the accuracy of saturation properties and influence parameters, and require equations of state (EoS) which exhibit a fundamentally consistent behavior in the two-phase regime. Widely applied multi-parameter EoS, however, are generally invalid inside this region. Hence, they may not be fully suitable for application in concert with Gradient Theory despite their ability to accurately predict saturation properties. The commonly assumed temperature-dependence of pure component influence parameters usually restricts their validity to subcritical temperature regimes. This may distort predictions for general multi-component interfaces where temperatures often exceed the critical temperature of vapor phase components. Then, the calculation of influence parameters is not well defined. In this paper, one of the first studies is presented in which Gradient Theory is combined with a next-generation Helmholtz energy EoS which facilitates fundamentally consistent calculations over the entire two-phase regime. Illustrated on pentafluoroethane as an example, reference simulations using this method are performed. They demonstrate the significance of such high-accuracy and fundamentally consistent calculations for the computation of interfacial properties. These reference simulations are compared to corresponding results from cubic PR EoS, widely-applied in combination with Gradient Theory, and mBWR EoS. The analysis reveals that neither of those two methods succeeds to consistently capture the qualitative distribution of obtained key thermodynamic properties in Gradient Theory. Furthermore, a generalized expression of the pure component influence parameter is presented. This development is informed by its fundamental definition based on the direct correlation function of the homogeneous fluid and by presented high-fidelity simulations of interfacial density profiles. The new model preserves the accuracy of previous temperature

  7. CEDR: Comprehensive Epidemiologic Data Resource

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The Department of Energy (DOE) and its predecessor agencies have a long history of epidemiologic research programs. The main focus of these programs has been the Health and Mortality Study of the DOE work force. This epidemiologic study began in 1964 with a feasibility study of workers at the Hanford facility. Studies of other populations exposed to radiation have also been supported, including the classic epidemiologic study of radium dial painters and studies of atomic bomb survivors. From a scientific perspective, these epidemiologic research program have been productive, highly credible, and formed the bases for many radiological protection standards. Recently, there has been concern that, although research results were available, the data on which these results were based were not easily obtained by interested investigators outside DOE. Therefore, as part of an effort to integrate and broaden access to its epidemiologic information, the DOE has developed the Comprehensive Epidemiologic Data Resource (CEDR) Program. Included in this effort is the development of a computer information system for accessing the collection of CEDR data and its related descriptive information. The epidemiologic data currently available through the CEDAR Program consist of analytic data sets, working data sets, and their associated documentation files. In general, data sets are the result of epidemiologic studies that have been conducted on various groups of workers at different DOE facilities during the past 30 years.

  8. Corrigendum for "The generalized strong recurrence for non-zero rational parameters" Archiv der Mathematik 95 (2010), 549-555

    CERN Document Server

    Nakamura, Takashi

    2012-01-01

    In the present paper, we prove that self-approximation of $\\log \\zeta (s)$ with $d=0$ is equivalent to the Riemann Hypothesis. Next, we show self-approximation of $\\log \\zeta (s)$ with respect to all nonzero real numbers $d$. Moreover, we partially filled a gap existing in "The strong recurrence for non-zero rational parameters" and prove self-approximation of $\\zeta(s)$ for $0 \

  9. Distributed Time-Varying Formation Robust Tracking for General Linear Multiagent Systems With Parameter Uncertainties and External Disturbances.

    Science.gov (United States)

    Hua, Yongzhao; Dong, Xiwang; Li, Qingdong; Ren, Zhang

    2017-05-18

    This paper investigates the time-varying formation robust tracking problems for high-order linear multiagent systems with a leader of unknown control input in the presence of heterogeneous parameter uncertainties and external disturbances. The followers need to accomplish an expected time-varying formation in the state space and track the state trajectory produced by the leader simultaneously. First, a time-varying formation robust tracking protocol with a totally distributed form is proposed utilizing the neighborhood state information. With the adaptive updating mechanism, neither any global knowledge about the communication topology nor the upper bounds of the parameter uncertainties, external disturbances and leader's unknown input are required in the proposed protocol. Then, in order to determine the control parameters, an algorithm with four steps is presented, where feasible conditions for the followers to accomplish the expected time-varying formation tracking are provided. Furthermore, based on the Lyapunov-like analysis theory, it is proved that the formation tracking error can converge to zero asymptotically. Finally, the effectiveness of the theoretical results is verified by simulation examples.

  10. Local and generalized height-diameter models with random parameters for mixed, uneven-aged forests in Northwestern Durango, Mexico

    Directory of Open Access Journals (Sweden)

    Sacramento Corral-Rivas

    2014-02-01

    Full Text Available Background We used mixed models with random components to develop height-diameter (h-d functions for mixed, uneven-aged stands in northwestern Durango (Mexico, considering the breast height diameter (d and stand variables as predictors. Methods The data were obtained from 44 permanent plots used to monitor stand growth under forest management in the study area. Results The generalized Bertalanffy-Richards model performed better than the other generalized models in predicting the total height of the species under study. For the genera Pinus and Quercus, the models were successfully calibrated by measuring the height of a subsample of three randomly selected trees close to the mean d, whereas for species of the genera Cupressus, Arbutus and Alnus, three trees were also selected, but they are specifically the maximum, minimum and mean d trees. Conclusions The presented equations represent a new tool for the evaluation and management of natural forest in the region.

  11. Phylogenetically resolving epidemiologic linkage.

    Science.gov (United States)

    Romero-Severson, Ethan O; Bulla, Ingo; Leitner, Thomas

    2016-03-08

    Although the use of phylogenetic trees in epidemiological investigations has become commonplace, their epidemiological interpretation has not been systematically evaluated. Here, we use an HIV-1 within-host coalescent model to probabilistically evaluate transmission histories of two epidemiologically linked hosts. Previous critique of phylogenetic reconstruction has claimed that direction of transmission is difficult to infer, and that the existence of unsampled intermediary links or common sources can never be excluded. The phylogenetic relationship between the HIV populations of epidemiologically linked hosts can be classified into six types of trees, based on cladistic relationships and whether the reconstruction is consistent with the true transmission history or not. We show that the direction of transmission and whether unsampled intermediary links or common sources existed make very different predictions about expected phylogenetic relationships: (i) Direction of transmission can often be established when paraphyly exists, (ii) intermediary links can be excluded when multiple lineages were transmitted, and (iii) when the sampled individuals' HIV populations both are monophyletic a common source was likely the origin. Inconsistent results, suggesting the wrong transmission direction, were generally rare. In addition, the expected tree topology also depends on the number of transmitted lineages, the sample size, the time of the sample relative to transmission, and how fast the diversity increases after infection. Typically, 20 or more sequences per subject give robust results. We confirm our theoretical evaluations with analyses of real transmission histories and discuss how our findings should aid in interpreting phylogenetic results.

  12. Constraints on the general solutions of Einstein cosmological equations by Hubble parameter times cosmic age: a historical perspective

    CERN Document Server

    Gonzalo, Julio A

    2013-01-01

    In a historical perspective, compact solutions of Einstein's equations, including the cosmological constant and the curvature terms, are obtained, starting from two recent observational estimates of the Hubble's parameter (H0) and the "age" of the universe (t0). Cosmological implications for {\\Lambda}CDM ({\\Lambda} Cold Dark Matter), KOFL (k Open Friedman-Lemaitre), plus two mixed solutions are investigated, under the constraints imposed by the relatively narrow current uncertainties. Quantitative results obtained for the KOFL case seem to be compatible with matter density and the highest observed red-shifts from distant galaxies, while those obtained for the {\\Lambda}CDM may be more difficult to reconcile.

  13. Optimization of GATE and PHITS Monte Carlo code parameters for uniform scanning proton beam based on simulation with FLUKA general-purpose code

    Energy Technology Data Exchange (ETDEWEB)

    Kurosu, Keita [Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Takashina, Masaaki; Koizumi, Masahiko [Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Moskvin, Vadim P., E-mail: vadim.p.moskvin@gmail.com [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States)

    2014-10-01

    Although three general-purpose Monte Carlo (MC) simulation tools: Geant4, FLUKA and PHITS have been used extensively, differences in calculation results have been reported. The major causes are the implementation of the physical model, preset value of the ionization potential or definition of the maximum step size. In order to achieve artifact free MC simulation, an optimized parameters list for each simulation system is required. Several authors have already proposed the optimized lists, but those studies were performed with a simple system such as only a water phantom. Since particle beams have a transport, interaction and electromagnetic processes during beam delivery, establishment of an optimized parameters-list for whole beam delivery system is therefore of major importance. The purpose of this study was to determine the optimized parameters list for GATE and PHITS using proton treatment nozzle computational model. The simulation was performed with the broad scanning proton beam. The influences of the customizing parameters on the percentage depth dose (PDD) profile and the proton range were investigated by comparison with the result of FLUKA, and then the optimal parameters were determined. The PDD profile and the proton range obtained from our optimized parameters list showed different characteristics from the results obtained with simple system. This led to the conclusion that the physical model, particle transport mechanics and different geometry-based descriptions need accurate customization in planning computational experiments for artifact-free MC simulation.

  14. A general method to derive tissue parameters for Monte Carlo dose calculation with multi-energy CT

    Science.gov (United States)

    Lalonde, Arthur; Bouchard, Hugo

    2016-11-01

    To develop a general method for human tissue characterization with dual- and multi-energy CT and evaluate its performance in determining elemental compositions and quantities relevant to radiotherapy Monte Carlo dose calculation. Ideal materials to describe human tissue are obtained applying principal component analysis on elemental weight and density data available in literature. The theory is adapted to elemental composition for solving tissue information from CT data. A novel stoichiometric calibration method is integrated to the technique to make it suitable for a clinical environment. The performance of the method is compared with two techniques known in literature using theoretical CT data. In determining elemental weights with dual-energy CT, the method is shown to be systematically superior to the water-lipid-protein material decomposition and comparable to the parameterization technique. In determining proton stopping powers and energy absorption coefficients with dual-energy CT, the method generally shows better accuracy and unbiased results. The generality of the method is demonstrated simulating multi-energy CT data to show the potential to extract more information with multiple energies. The method proposed in this paper shows good performance to determine elemental compositions from dual-energy CT data and physical quantities relevant to radiotherapy dose calculation. The method is particularly suitable for Monte Carlo calculations and shows promise in using more than two energies to characterize human tissue with CT.

  15. A general method to derive tissue parameters for Monte Carlo dose calculation with multi-energy CT.

    Science.gov (United States)

    Lalonde, Arthur; Bouchard, Hugo

    2016-11-21

    To develop a general method for human tissue characterization with dual- and multi-energy CT and evaluate its performance in determining elemental compositions and quantities relevant to radiotherapy Monte Carlo dose calculation. Ideal materials to describe human tissue are obtained applying principal component analysis on elemental weight and density data available in literature. The theory is adapted to elemental composition for solving tissue information from CT data. A novel stoichiometric calibration method is integrated to the technique to make it suitable for a clinical environment. The performance of the method is compared with two techniques known in literature using theoretical CT data. In determining elemental weights with dual-energy CT, the method is shown to be systematically superior to the water-lipid-protein material decomposition and comparable to the parameterization technique. In determining proton stopping powers and energy absorption coefficients with dual-energy CT, the method generally shows better accuracy and unbiased results. The generality of the method is demonstrated simulating multi-energy CT data to show the potential to extract more information with multiple energies. The method proposed in this paper shows good performance to determine elemental compositions from dual-energy CT data and physical quantities relevant to radiotherapy dose calculation. The method is particularly suitable for Monte Carlo calculations and shows promise in using more than two energies to characterize human tissue with CT.

  16. Prospects of Dynamical Determination of General Relativity Parameter β and Solar Quadrupole Moment {J}_{2\\odot } with Asteroid Radar Astronomy

    Science.gov (United States)

    Verma, Ashok K.; Margot, Jean-Luc; Greenberg, Adam H.

    2017-08-01

    We evaluated the prospects of quantifying the parameterized post-Newtonian parameter β and solar quadrupole moment {J}2⊙ with observations of near-Earth asteroids with large orbital precession rates (9 to 27 arcsec century-1). We considered existing optical and radar astrometry, as well as radar astrometry that can realistically be obtained with the Arecibo planetary radar in the next five years. Our sensitivity calculations relied on a traditional covariance analysis and Monte Carlo simulations. We found that independent estimates of β and {J}2⊙ can be obtained with precisions of 6 × 10-4 and 3 × 10-8, respectively. Because we assumed rather conservative observational uncertainties, as is the usual practice when reporting radar astrometry, it is likely that the actual precision will be closer to 2 × 10-4 and 10-8, respectively. A purely dynamical determination of solar oblateness with asteroid radar astronomy may therefore rival the helioseismology determination.

  17. Corneal refractive power and its associations with ocular and general parameters: the Central India Eye and Medical Study.

    Science.gov (United States)

    Jonas, Jost B; Nangia, Vinay; Sinha, Ajit; Gupta, Rajesh

    2011-09-01

    To investigate the normal distribution of corneal refractive power (CRP) and its associations with other ocular and systemic parameters in the Central Indian population. Population-based study. The Central India Eye and Medical Study is a population-based study performed in a rural region of Central India. The study comprised 4711 subjects aged 30+ years. A detailed ophthalmic and medical examination was performed. Horizontal and vertical CRP were measured using a non-automatic keratometer. Corneal refractive power. After excluding pseudophakic or aphakic eyes, keratometric measurements were available on 9024 eyes of 4617 study participants (98.0%) with a mean age of 49.1±13.2 years (range, 30-100 years) and a mean refractive error of -0.20±1.52 diopters (D). Mean horizontal CRP was 44.60±1.68 D (mean ± standard deviation; range, 36.5-52.0 D), and vertical CRP was 44.62±1.74 D (range, 37.75-52.0 D) with no significant difference between both parameters (P=0.27). In multivariate analysis, CRP was significantly (P eyes with CRP ≥48 D were excluded. Horizontal CRP increased with higher age, lower level of education, lower body height, thinner central cornea, deeper anterior chamber, shorter axial length, and myopic refractive error. The association with age may be of importance for refractive surgery. The association of a steeper cornea with a shorter body stature and a shorter axial length parallels an association between shorter body length and shorter axial length without association with refractive error. The association among steeper cornea, shorter body length, and lower educational level complements the association between shorter body length and lower educational level. The correlation between steeper cornea and deeper anterior chamber may be explained geometrically. Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  18. Exposure to ionizing radiations having a medical origin. Propositions for the implementation and the development of epidemiology surveillance activities in general population; Exposition aux rayonnements ionisants d'origine medicale. Propositions pour la mise en place et le developpement d'activites de surveillance epidemiologique en population generale

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-09-01

    This report gives propositions relative to the implementation and the development of epidemiology surveillance activities in general population in relation with medical exposure to ionizing radiations. It is intended for the General Direction of Health and General Direction of Nuclear Safety and Radiation Protection. These propositions have been elaborated by a work group coordinated and run by InVS and gathering the following organisms: French Agency of sanitary safety of health products (A.F.S.S.A.P.S.), Center of Quality Assurance of technological applications in the area of health (C.A.A.T.S.), Direction of Hospitals and Care organization (D.H.O.S.), General Direction of Health (D.G.S.), General Direction of Nuclear Safety and Radiation Protection (D.G.S.N.R.), National Federation of radiologists physicists (F.N.M.R.), institute of Radiation Protection and Nuclear Safety (I.R.S.N.), INSERM 'epidemiology of cancers', French Society of Biology and Nuclear Medicine (S.F.B.M.N.), French Society of Medical Physics (S.F.P.M.), French Society of Radiology (S.F.R.). (N.C.)

  19. Epidemiology chapter.

    Science.gov (United States)

    Wolfram, J H; Butaev, M K; Duysheev, A; Gabbasova, A R; Khasanov, O S; Kulakov, Yu K; Mkrtchyan, A R; Myrzabekov, A M; Nurgaziev, R Z; Tsirel'son, L E; Willer, R D; Yaraev, R G; Zheludkov, M M

    2010-10-01

    This chapter outlines the epidemiology of brucellosis in the Russian Federation and in five countries bordering Russia. Since the Soviet Union's dissolution, Russia and the newly formed independent republics have failed to maintain policies to control brucellosis and other zoonotic diseases. Many of these republics, due to weak animal control and prevention systems and dangerous food preparation practices, are still burdened with the human cost of brucellosis. The final summary of this section provides an example of the successful transboundary cooperative efforts between Arizona and Mexico, which could be applied to the situation between Russia and the bordering independent republics.

  20. Associations of common variants in HFE and TMPRSS6 with iron parameters are independent of serum hepcidin in a general population: a replication study.

    Science.gov (United States)

    Galesloot, Tessel E; Geurts-Moespot, Anneke J; den Heijer, Martin; Sweep, Fred C G J; Fleming, Robert E; Kiemeney, Lambertus A L M; Vermeulen, Sita H; Swinkels, Dorine W

    2013-09-01

    Genome-wide association studies have convincingly shown that single nucleotide polymorphisms (SNPs) in HFE and TMPRSS6 are associated with iron parameters. It was commonly thought that these associations could be explained by the intermediate effect on hepcidin concentration. A recent study in an isolated Italian population, however, concluded that these associations were not exclusively dependent on hepcidin values. We report here the second study to investigate the role of hepcidin in the associations between common variants in HFE and TMPRSS6 with iron parameters. We extracted 101 SNPs in HFE and TMPRSS6 from genome-wide imputed SNP data of 1832 individuals from the general population (Nijmegen Biomedical Study). Single locus and haplotype associations with serum iron parameters and hepcidin were studied using linear regression analyses. We found that HFE rs1800562 and TMPRSS6 rs855791 are the main determinants of HFE and TMPRSS6 related variation in serum iron, ferritin, transferrin saturation, and total iron binding capacity. These SNPs are associated with the ratios hepcidin/ferritin (pserum hepcidin (p>0.2). Adjustment for hepcidin or the ratio hepcidin/ferritin did not decrease the strength of the SNP-iron parameter associations. Our results do not support an intermediate role for hepcidin in the SNP-iron parameter associations, which confirms previous findings, and indicate a pleiotropic SNP effect on the hepcidin ratios and the iron parameters. Taken together, this suggests that there might be other, yet unknown, serum hepcidin independent mechanisms which play a role in the association of HFE and TMPRSS6 variants with serum iron parameters.

  1. Benefit of general anesthesia monitored by bispectral index compared with monitoring guided only by clinical parameters. Systematic review and meta-analysis.

    Science.gov (United States)

    Oliveira, Carlos Rogério Degrandi; Bernardo, Wanderley Marques; Nunes, Victor Moisés

    The bispectral index parameter is used to guide the titration of general anesthesia; however, many studies have shown conflicting results regarding the benefits of bispectral index monitoring. The objective of this systematic review with meta-analysis is to evaluate the clinical impact of monitoring with the bispectral index parameter. The search for evidence in scientific information sources was conducted during December 2013 to January 2015, the following primary databases: Medline/PubMed, LILACS, Cochrane, CINAHL, Ovid, SCOPUS and TESES. The criteria for inclusion in the study were randomized controlled trials, comparing general anesthesia monitored, with bispectral index parameter with anesthesia guided solely by clinical parameters, and patients aged over 18 years. The criteria for exclusion were studies involving anesthesia or sedation for diagnostic procedures, and intraoperative wake-up test for surgery of the spine. The use of monitoring with the bispectral index has shown benefits reducing time to extubation, orientation in time and place, and discharge from both the operating room and post anesthetic care unit. The risk of nausea and vomiting after surgery was reduced by 12% in patients monitored with bispectral index. Occurred a reduction of 3% in the risk of cognitive impairment postoperatively at 3 months postoperatively and 6% reduction in the risk of postoperative delirium in patients monitored with bispectral index. Furthermore, the risk of intraoperative memory has been reduced by 1%. Clinically, anesthesia monitoring with the BIS can be justified because it allows advantages from reducing the recovery time after waking, mainly by reducing the administration of general anesthetics as well as the risk of adverse events. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

  2. [Benefit of general anesthesia monitored by bispectral index compared with monitoring guided only by clinical parameters. Systematic review and meta-analysis].

    Science.gov (United States)

    Oliveira, Carlos Rogério Degrandi; Bernardo, Wanderley Marques; Nunes, Victor Moisés

    The bispectral index parameter is used to guide the titration of general anesthesia; however, many studies have shown conflicting results regarding the benefits of bispectral index monitoring. The objective of this systematic review with meta-analysis is to evaluate the clinical impact of monitoring with the bispectral index parameter. The search for evidence in scientific information sources was conducted during December 2013 to January 2015, the following primary databases: Medline/PubMed, LILACS, Cochrane, CINAHL, Ovid, SCOPUS and TESES. The criteria for inclusion in the study were randomized controlled trials, comparing general anesthesia monitored, with bispectral index parameter with anesthesia guided solely by clinical parameters, and patients aged over 18 years. The criteria for exclusion were studies involving anesthesia or sedation for diagnostic procedures, and intraoperative wake-up test for surgery of the spine. The use of monitoring with the bispectral index has shown benefits reducing time to extubation, orientation in time and place, and discharge from both the operating room and post anesthetic care unit. The risk of nausea and vomiting after surgery was reduced by 12% in patients monitored with bispectral index. Occurred a reduction of 3% in the risk of cognitive impairment postoperatively at 3 months postoperatively and 6% reduction in the risk of postoperative delirium in patients monitored with bispectral index. Furthermore, the risk of intraoperative memory has been reduced by 1%. Clinically, anesthesia monitoring with the BIS can be justified because it allows advantages from reducing the recovery time after waking, mainly by reducing the administration of general anesthetics as well as the risk of adverse events. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  3. Oncology. Pt. 1. General part, epidemiology - pathogenesis - basic principles of therapy. 2. upd. ed.; Die Onkologie. T. 1. Allgemeiner Teil, Epidemiologie - Pathogenese - Grundprinzipien der Therapie

    Energy Technology Data Exchange (ETDEWEB)

    Hiddemann, Wolfgang [Muenchen Univ. Klinikum Grosshadern (Germany). Medizinische Klinik und Poliklinik III; Bartram Claus R. (eds.) [Heidelberg Univ. (Germany). Inst. fuer Humangenetik

    2010-07-01

    The book Oncology is aimed to communicate the compiled knowledge on tumor development and cancer: fundamental knowledge base, practice related know-how for diagnostics and therapy. Part 1 includes the following chapters: epidemiology and pathogenesis, basic principles of diagnostics, basic principles of therapy, complication of malign growth, tumors in the gastrointestinal tract, female genital carcinomas, kidney and urinary tract carcinomas, respiratory tract and lung carcinomas, carcinomas in the head - neck area, bone and soft tissue carcinomas, pediatric tumors, hematological neoplasm, other carcinomas. The book can be used as reference for clinical work. [German] Die gesamte Onkologie - verlaessliches Wissen fuer Ihre Kompetenz. ''Die Onkologie'' stellt sich der Herausforderung, das staendig wachsende Wissen ueber Tumorerkrankungen in seiner Gesamtheit zu vermitteln. Sowohl inhaltlich als auch didaktisch auf hoechsten Niveau: Fundiertes Grundlagenwissen zum umfassenden Nachschlagen Praxisrelevantes Know-how fuer Diagnostik und Therapie Systematischer Aufbau fuer das Verstaendnis der komplexen Zusammenhaenge Die Onkologie - eine Enzyklopaedie der modernen klinischen Tumorlehre. Angesehene Experten aus Klinik, Forschung und Praxis liefern Ihnen in Teil1 klinisches Grundlagenwissen zu den Grundprinzipien der Therapie, Epidemiologie, Aetiologie und Pathogenese, sowie zu Komplikationen des malignen Wachstums. Zum Nachschlagen und Anwenden: finden Sie alle Optionen - auch fuer Ihren schwierigsten Fall. Der uebersichtliche Aufbau und die exzellenten Abbildungen erleichtern Ihnen das schnelle Auffinden und Verstaendnis der gesuchten Informationen. Fuer den Alltag onkologisch taetiger Aerzte ist Die Onkologie ein unentbehrlicher Meilenstein. (orig.)

  4. From epidemiology to daily life : Linking daily life stress reactivity to persistence of psychotic experiences in a longitudinal general population study

    NARCIS (Netherlands)

    Collip, Dina; Wigman, Johanna T. W.; Myin-Germeys, Inez; Jacobs, Nele; Derom, Catherine; Thiery, Evert; Wichers, Marieke; van Os, Jim

    2013-01-01

    Subclinical psychotic experiences at the level of the general population are common, forming an extended psychosis phenotype with clinical psychosis. Persistence of subclinical experiences is associated with transition to later mental disorder. Increased daily life stress reactivity is considered an

  5. Modulational instability and higher-order rogue waves with parameters modulation in a coupled integrable AB system via the generalized Darboux transformation.

    Science.gov (United States)

    Wen, Xiao-Yong; Yan, Zhenya

    2015-12-01

    We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.

  6. Modulational instability and higher-order rogue waves with parameters modulation in a coupled integrable AB system via the generalized Darboux transformation

    Science.gov (United States)

    Wen, Xiao-Yong; Yan, Zhenya

    2015-12-01

    We study higher-order rogue wave (RW) solutions of the coupled integrable dispersive AB system (also called Pedlosky system), which describes the evolution of wave-packets in a marginally stable or unstable baroclinic shear flow in geophysical fluids. We propose its continuous-wave (CW) solutions and existent conditions for their modulation instability to form the rogue waves. A new generalized N-fold Darboux transformation (DT) is proposed in terms of the Taylor series expansion for the spectral parameter in the Darboux matrix and its limit procedure and applied to the CW solutions to generate multi-rogue wave solutions of the coupled AB system, which satisfy the general compatibility condition. The dynamical behaviors of these higher-order rogue wave solutions demonstrate both strong and weak interactions by modulating parameters, in which some weak interactions can generate the abundant triangle, pentagon structures, etc. Particularly, the trajectories of motion of peaks and depressions of profiles of the first-order RWs are explicitly analyzed. The generalized DT method used in this paper can be extended to other nonlinear integrable systems. These results may be useful for understanding the corresponding rogue-wave phenomena in fluid mechanics and related fields.

  7. Epidemiology and Clinical Parameters of Adult Human ...

    African Journals Online (AJOL)

    on the 6 months' visit, giving a follow‑up rate of 95.2% (381/400). There was ... Adult HIV/AIDS at initiation of antiretroviral therapy in Nigeria. 218 .... transmitted infections, low levels of condom use and poverty. Our data set .... Rice BD, et al.

  8. Impact of Material and Architecture Model Parameters on the Failure of Woven Ceramic Matrix Composites (CMCs) via the Multiscale Generalized Method of Cells

    Science.gov (United States)

    Liu, Kuang C.; Arnold, Steven M.

    2011-01-01

    It is well known that failure of a material is a locally driven event. In the case of ceramic matrix composites (CMCs), significant variations in the microstructure of the composite exist and their significance on both deformation and life response need to be assessed. Examples of these variations include changes in the fiber tow shape, tow shifting/nesting and voids within and between tows. In the present work, the effects of many of these architectural parameters and material scatter of woven ceramic composite properties at the macroscale (woven RUC) will be studied to assess their sensitivity. The recently developed Multiscale Generalized Method of Cells methodology is used to determine the overall deformation response, proportional elastic limit (first matrix cracking), and failure under tensile loading conditions. The macroscale responses investigated illustrate the effect of architectural and material parameters on a single RUC representing a five harness satin weave fabric. Results shows that the most critical architectural parameter is weave void shape and content with other parameters being less in severity. Variation of the matrix material properties was also studied to illustrate the influence of the material variability on the overall features of the composite stress-strain response.

  9. [Workshop on Molecular Epidemiology of Viral Diseases].

    Science.gov (United States)

    Gómez, B; Cabrera, L; Arias, C F

    1997-01-01

    A workshop on viral epidemiology was held on September 29, 1995 at the Medical School of the Universidad Nacional Autónoma de Mexico. The aim of this workshop was to promote interaction among scientists working in viral epidemiology. Eighteen scientists from ten institutions presented their experiences and work. General aspects of the epidemiology of meaningful viral diseases in the country were discussed, and lectures presented on the rota, polio, respiratory syncytial, dengue, papiloma, rabies, VIH and hepatitis viruses.

  10. Efficient determination of the critical parameters and the statistical quantities for Klein-Gordon and sine-Gordon equations with a singular potential using generalized polynomial chaos methods

    CERN Document Server

    Chakraborty, Debananda

    2011-01-01

    We consider the Klein-Gordon and sine-Gordon type equations with a point-like potential, which describes the wave phenomenon in disordered media with a defect. The singular potential term yields a critical phenomenon--that is, the solution behavior around the critical parameter value bifurcates into two extreme cases. Pinpointing the critical value with arbitrary accuracy is even more challenging. In this work, we adopt the generalized polynomial chaos (gPC) method to determine the critical values and the mean solutions around such values. First, we consider the critical value associated with the strength of the singular potential for the Klein-Gordon equation. We expand the solution in the random variable associated with the parameter. The obtained partial differential equations are solved using the Chebyshev collocation method. Due to the existence of the singularity, the Gibbs phenomenon appears in the solution, yielding a slow convergence of the numerically computed critical value. To deal with the singul...

  11. Mathematical epidemiology

    CERN Document Server

    Driessche, Pauline; Wu, Jianhong

    2008-01-01

    Based on lecture notes of two summer schools with a mixed audience from mathematical sciences, epidemiology and public health, this volume offers a comprehensive introduction to basic ideas and techniques in modeling infectious diseases, for the comparison of strategies to plan for an anticipated epidemic or pandemic, and to deal with a disease outbreak in real time. It covers detailed case studies for diseases including pandemic influenza, West Nile virus, and childhood diseases. Models for other diseases including Severe Acute Respiratory Syndrome, fox rabies, and sexually transmitted infections are included as applications. Its chapters are coherent and complementary independent units. In order to accustom students to look at the current literature and to experience different perspectives, no attempt has been made to achieve united writing style or unified notation. Notes on some mathematical background (calculus, matrix algebra, differential equations, and probability) have been prepared and may be downlo...

  12. A New General Method for Simultaneous Fitting of Temperature- and Concentration-Dependence of Reaction Rates Yields Kinetic and Thermodynamic Parameters for HIV Reverse Transcriptase Specificity.

    Science.gov (United States)

    Li, An; Ziehr, Jessica L; Johnson, Kenneth A

    2017-03-02

    Recent studies have demonstrated the dominant role of induced-fit in enzyme specificity of HIV reverse transcriptase and many other enzymes. However, relevant thermodynamic parameters are lacking and equilibrium thermodynamic methods are of no avail because the key parameters can only determined by kinetic measurement. By modifying KinTek Explorer software, we present a new general method for globally fitting data collected over a range of substrate concentrations and temperatures and apply it to HIV reverse transcriptase. Fluorescence stopped-flow methods were used to record the kinetics of enzyme conformational changes that monitor nucleotide binding and incorporation. The nucleotide concentration dependence was measured at temperatures ranging from 5 to 37C and the raw data were fit globally to derive a single set of rate constants at 37C and a set of activation enthalpy terms to account for the kinetics at all other temperatures. This comprehensive analysis afforded thermodynamic parameters for nucleotide binding (Kd, ΔG, ΔH, ΔS at 37C), and kinetic parameters for enzyme conformational changes and chemistry (rate constants and activation enthalpy). Comparisons between wild-type enzyme and a mutant resistant to nucleoside analogs used to treat HIV infections reveal that the ground state binding is weaker and the activation enthalpy for the conformational change step is significantly larger for the mutant. Further studies to explore the structural underpinnings of the observed thermodynamics and kinetics of the conformational change step may help to design better analogs to treat HIV infections and other diseases. Our new method is generally applicable to enzyme and chemical kinetics.

  13. A MEASUREMENT OF SOCIAL SUPPORT IN EPIDEMIOLOGIC RESEARCH - THE SOCIAL EXPERIENCES CHECKLIST TESTED IN A GENERAL-POPULATION IN THE NETHERLANDS

    NARCIS (Netherlands)

    VANOOSTROM, MA; TIJHUIS, MAR; DEHAES, JCJM; KROMHOUT, D

    1995-01-01

    Study objective - This study aimed to examine in a general population the psychometric qualities of an instrument designed to measure positive and negative social experiences that had been developed in a clinical setting. Design - The Netherlands monitoring project on cardiovascular disease risk fac

  14. SU-E-T-254: Optimization of GATE and PHITS Monte Carlo Code Parameters for Uniform Scanning Proton Beam Based On Simulation with FLUKA General-Purpose Code

    Energy Technology Data Exchange (ETDEWEB)

    Kurosu, K [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Osaka (Japan); Department of Medical Physics ' Engineering, Osaka University Graduate School of Medicine, Osaka (Japan); Takashina, M; Koizumi, M [Department of Medical Physics ' Engineering, Osaka University Graduate School of Medicine, Osaka (Japan); Das, I; Moskvin, V [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN (United States)

    2014-06-01

    Purpose: Monte Carlo codes are becoming important tools for proton beam dosimetry. However, the relationships between the customizing parameters and percentage depth dose (PDD) of GATE and PHITS codes have not been reported which are studied for PDD and proton range compared to the FLUKA code and the experimental data. Methods: The beam delivery system of the Indiana University Health Proton Therapy Center was modeled for the uniform scanning beam in FLUKA and transferred identically into GATE and PHITS. This computational model was built from the blue print and validated with the commissioning data. Three parameters evaluated are the maximum step size, cut off energy and physical and transport model. The dependence of the PDDs on the customizing parameters was compared with the published results of previous studies. Results: The optimal parameters for the simulation of the whole beam delivery system were defined by referring to the calculation results obtained with each parameter. Although the PDDs from FLUKA and the experimental data show a good agreement, those of GATE and PHITS obtained with our optimal parameters show a minor discrepancy. The measured proton range R90 was 269.37 mm, compared to the calculated range of 269.63 mm, 268.96 mm, and 270.85 mm with FLUKA, GATE and PHITS, respectively. Conclusion: We evaluated the dependence of the results for PDDs obtained with GATE and PHITS Monte Carlo generalpurpose codes on the customizing parameters by using the whole computational model of the treatment nozzle. The optimal parameters for the simulation were then defined by referring to the calculation results. The physical model, particle transport mechanics and the different geometrybased descriptions need accurate customization in three simulation codes to agree with experimental data for artifact-free Monte Carlo simulation. This study was supported by Grants-in Aid for Cancer Research (H22-3rd Term Cancer Control-General-043) from the Ministry of Health

  15. Realization of a Four Parameter Family of Generalized One-Dimensional Contact Interactions by Three Nearby Delta Potentials with Renormalized Strengths

    CERN Document Server

    Shigehara, T; Mishima, T; Cheon, T; Cheon, Taksu

    1999-01-01

    We propose a new method to construct a four parameter family of quantum-mechanical point interactions in one dimension, which is known as all possible self-adjoint extensions of the symmetric operator $T=-\\Delta \\lceil C^{\\infty}_{0}({\\bf R} \\backslash\\{0\\})$. It is achieved in the small distance limit of equally spaced three neighboring Dirac's $\\delta$ potentials. The strength for each $\\delta$ is appropriately renormalized according to the distance and it diverges, in general, in the small distance limit. The validity of our method is ensured by numerical calculations. In general cases except for usual $\\delta$, the wave function discontinuity appears around the interaction and one can observe such a tendency even at a finite distance level.

  16. General aspects of peptide selectivity towards lipid bilayers and cell membranes studied by variation of the structural parameters of amphipathic helical model peptides.

    Science.gov (United States)

    Dathe, Margitta; Meyer, Jana; Beyermann, Michael; Maul, Björn; Hoischen, Christian; Bienert, Michael

    2002-02-01

    Model compounds of modified hydrophobicity (Eta), hydrophobic moment (mu) and angle subtended by charged residues (Phi) were synthesized to define the general roles of structural motifs of cationic helical peptides for membrane activity and selectivity. The peptide sets were based on a highly hydrophobic, non-selective KLA model peptide with high antimicrobial and hemolytic activity. Variation of the investigated parameters was found to be a suitable method for modifying peptide selectivity towards either neutral or highly negatively charged lipid bilayers. Eta and mu influenced selectivity preferentially via modification of activity on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) bilayers, while the size of the polar/hydrophobic angle affected the activity against 1-palmitoyl-2-oleoylphosphatidyl-DL-glycerol (POPG). The influence of the parameters on the activity determining step was modest in both lipid systems and the activity profiles were the result of the parameters' influence on the second less pronounced permeabilization step. Thus, the activity towards POPC vesicles was determined by the high permeabilizing efficiency, however, changes in the structural parameters preferentially influenced the relatively moderate affinity. In contrast, intensive peptide accumulation via electrostatic interactions was sufficient for the destabilization of highly negatively charged POPG lipid membranes, but changes in the activity profile, as revealed by the modification of Phi, seem to be preferentially caused by variation of the low permeabilizing efficiency. The parameters proved very effective also in modifying antimicrobial and hemolytic activity. However, their influence on cell selectivity was limited. A threshold value of hydrophobicity seems to exist which restricted the activity modifying potential of mu and Phi on both lipid bilayers and cell membranes.

  17. Worldwide epidemiology of fibromyalgia.

    Science.gov (United States)

    Queiroz, Luiz Paulo

    2013-08-01

    Studying the epidemiology of fibromyalgia (FM) is very important to understand the impact of this disorder on persons, families and society. The recent modified 2010 classification criteria of the American College of Rheumatology (ACR), without the need of tender points palpation, allows that larger and nationwide surveys may be done, worldwide. This article reviews the prevalence and incidence studies done in the general population, in several countries/continents, the prevalence of FM in special groups/settings, the association of FM with some sociodemographic characteristics of the population, and the comorbidity of FM with others disorders, especially with headaches.

  18. A generalized nonlinear tempeature response function for some growth and developmental parameters in kiwifruit (Actinidia deliciosa (A. Chev. C. F. Liang & A. R. Ferguson

    Directory of Open Access Journals (Sweden)

    Streck Nereu Augusto

    2003-01-01

    Full Text Available Temperature is a major factor that affects metabolic processes in living organisms. Thermal time has been widely used to account for the effects of temperature on crop growth and development. However, the thermal time approach has been criticized because it assumes a linear relationship between the rate of crop growth or development and temperature. The response of the rate of crop growth and development to temperature is nonlinear. The objective of this study was to develop a generalized nonlinear temperature response function for some growth and developmental parameters in kiwifruit (Actinidia deliciosa (A. Chev. C. F. Liang & A. R. Ferguson. The nonlinear function has three coefficients (the cardinal temperatures, which were 0ºC, 25ºC, and 40ºC. Data of temperature response of relative growth rate, relative leaf area growth, net photosynthesis rate, and leaf appearance rate in kiwifruit (female cv. Hayward at two light levels, which are from published research, were used as independent data for evaluating the performance of the nonlinear and the thermal time functions. The results showed that the generalized nonlinear response function is better than the thermal time approach, and the temperature response of several growth and developmental parameters in kiwifruit can be described with the same response function.

  19. Accurate estimation of seismic source parameters of induced seismicity by a combined approach of generalized inversion and genetic algorithm: Application to The Geysers geothermal area, California

    Science.gov (United States)

    Picozzi, M.; Oth, A.; Parolai, S.; Bindi, D.; De Landro, G.; Amoroso, O.

    2017-05-01

    The accurate determination of stress drop, seismic efficiency, and how source parameters scale with earthquake size is an important issue for seismic hazard assessment of induced seismicity. We propose an improved nonparametric, data-driven strategy suitable for monitoring induced seismicity, which combines the generalized inversion technique together with genetic algorithms. In the first step of the analysis the generalized inversion technique allows for an effective correction of waveforms for attenuation and site contributions. Then, the retrieved source spectra are inverted by a nonlinear sensitivity-driven inversion scheme that allows accurate estimation of source parameters. We therefore investigate the earthquake source characteristics of 633 induced earthquakes (Mw 2-3.8) recorded at The Geysers geothermal field (California) by a dense seismic network (i.e., 32 stations, more than 17.000 velocity records). We find a nonself-similar behavior, empirical source spectra that require an ωγ source model with γ > 2 to be well fit and small radiation efficiency ηSW. All these findings suggest different dynamic rupture processes for smaller and larger earthquakes and that the proportion of high-frequency energy radiation and the amount of energy required to overcome the friction or for the creation of new fractures surface changes with earthquake size. Furthermore, we observe also two distinct families of events with peculiar source parameters that in one case suggests the reactivation of deep structures linked to the regional tectonics, while in the other supports the idea of an important role of steeply dipping faults in the fluid pressure diffusion.

  20. Epidemiological factors associated with ESBL- and non ESBL-producing E. coli causing urinary tract infection in general practice

    DEFF Research Database (Denmark)

    Hertz, Frederik Boetius; Schønning, Kristian; Rasmussen, Steen Christian

    2016-01-01

    The purpose of the study was to evaluate how use of antibiotics precedes the presence of ESBL-producing E.coli in general practice. The authors performed a triple-case-control study where three case groups were individually compared to a single control group of uninfected individuals. Urine samples...... were prospectively collected and retrospective statistical analyses were done. This study included 98 cases with urinary tract infection (UTI) caused by ESBL-producing E. coli, 174 with antibiotic-resistant (non-ESBL) E. coli, 177 with susceptible E. coli and 200 with culture negative urine samples...

  1. Coccidioidomycosis: epidemiology

    Directory of Open Access Journals (Sweden)

    Brown J

    2013-06-01

    Full Text Available Jennifer Brown,1 Kaitlin Benedict,2 Benjamin J Park,2 George R Thompson III1,31Department of Internal Medicine, Division of Infectious Diseases, University of California, Davis Medical Center, Sacramento, CA, USA; 2Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, USA; 3Department of Medical Microbiology and Immunology, One Shields Avenue, Tupper Hall, Coccidioidomycosis Serology Laboratory, University of California, Davis, CA, USAAbstract: Coccidioidomycosis consists of a spectrum of disease, ranging from a mild, self-limited, febrile illness to severe, life-threatening infection. It is caused by the soil-dwelling fungi, Coccidioides immitis and C. posadasii, which are present in diverse endemic areas. Climate changes and environmental factors affect the Coccidioides lifecycle and influence infection rates. The incidence of coccidioidomycosis has risen substantially over the past two decades. The vast majority of Coccidioides infections occur in the endemic zones, such as California, Arizona, Mexico, and Central America. Infections occurring outside those zones appear to be increasingly common, and pose unique clinical and public health challenges. It has long been known that elderly persons, pregnant women, and members of certain ethnic groups are at risk for severe or disseminated coccidioidomycosis. In recent years, it has become evident that persons with immunodeficiency diseases, diabetics, transplant recipients, and prisoners are also particularly vulnerable.Keywords: coccidioidomycosis, Coccidioides, epidemiology, incidence, risk factors, geography

  2. Gonorrhoea and Syphilis Epidemiology in Flemish General Practice 2009–2013: Results from a Registry-based Retrospective Cohort Study Compared with Mandatory Notification

    Directory of Open Access Journals (Sweden)

    Christoph Schweikardt

    2016-09-01

    Full Text Available Background: The number of newly diagnosed gonorrhoea and syphilis cases has increased in Flanders in recent years. Our aim was to investigate, to which extent these diagnoses were registered by general practitioners (GPs, and to examine opportunities and limits of the Intego database in this regard. Methods: Data from a retrospective cohort study based on the Flemish Intego general practice database was analyzed for the years 2009–2013. Case definitions were applied. Due to small case numbers obtained, cases were pooled and averaged over the observation period. Frequencies were compared with those calculated from figures of mandatory notification. Results: A total of 91 gonorrhoea and 23 syphilis cases were registered. The average Intego annual frequency of gonorrhoea cases obtained was 11.9 (95% Poisson confidence interval (CI 9.6; 14.7 per 100,000 population, and for syphilis 3.0 (CI 1.9; 4.5, respectively, while mandatory notification was calculated at 14.0 (CI: 13.6, 14.4 and 7.0 (CI: 6.7, 7.3, respectively. Conclusion: In spite of limitations such as small numbers and different case definitions, comparison with mandatory notification suggests that the GP was involved in the large majority of gonorrhoea cases, while the majority of new syphilis cases did not come to the knowledge of the GP.

  3. [Eco-epidemiology: towards epidemiology of complexity].

    Science.gov (United States)

    Bizouarn, Philippe

    2016-05-01

    In order to solve public health problems posed by the epidemiology of risk factors centered on the individual and neglecting the causal processes linking the risk factors with the health outcomes, Mervyn Susser proposed a multilevel epidemiology called eco-epidemiology, addressing the interdependence of individuals and their connection with molecular, individual, societal, environmental levels of organization participating in the causal disease processes. The aim of this epidemiology is to integrate more than a level of organization in design, analysis and interpretation of health problems. After presenting the main criticisms of risk-factor epidemiology focused on the individual, we will try to show how eco-epidemiology and its development could help to understand the need for a broader and integrative epidemiology, in which studies designed to identify risk factors would be balanced by studies designed to answer other questions equally vital to public health.

  4. Epidemiological survey of generalized anxiety disorder in Yunfu City%云浮市广泛性焦虑障碍流行病学调查

    Institute of Scientific and Technical Information of China (English)

    钟书铭; 肖垚南; 陈妙扬; 郑洪波; 张璐璐; 陈丁玲; 卢冬艳

    2015-01-01

    目的:了结云浮市15岁以上人群广泛性焦虑障碍的患病率及分布特点。方法采用初级单位含量比例分层整体随机抽样方法,以美国精神障碍诊断与统计手册第4版(DSM-Ⅳ)轴障碍定式临床检查患者版(SCID-Ⅰ/P)对全市5县区2373人进行入户面访调查。结果广泛性焦虑障碍的时点患病率为0.46%,其中男性为0.30%,女性为0.69%,该疾病与无业或失业状态关系密切,精神科就诊率为18.18%。结论广泛性焦虑障碍在云浮市患病率较高,就诊率较低,健全社区精神卫生服务有利于降低其发生发展。%Objective To describe the prevalence and distribution of generalized anxiety disorder among people aged above 15 years in Yunfu city. Methods A total of 2 373 subjects were randomly selected from 5 rural and rural-urban fringe zone by the elementary unit stratified cluster sampling method. They were assessed by face to face interview with United States Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-Ⅳ) AxisⅠDisorders-style version of the clinical examination of patients (SCID-Ⅰ/P). Results The current prevalence of gen-eralized anxiety disorder was 0.46%. It was 0.30%of male and 0.69%of female. The disease was closely associated with unemployed status, and its rate of visiting the doctors was 18.8%. Conclusion The prevalence of generalized anxiety disorder in Yunfu city was relatively high, while the visiting rate was low. Occurrence and development of the disease could be reduced by improving mental health service.

  5. From epidemiology to daily life: linking daily life stress reactivity to persistence of psychotic experiences in a longitudinal general population study.

    Directory of Open Access Journals (Sweden)

    Dina Collip

    Full Text Available Subclinical psychotic experiences at the level of the general population are common, forming an extended psychosis phenotype with clinical psychosis. Persistence of subclinical experiences is associated with transition to later mental disorder. Increased daily life stress reactivity is considered an endophenotype for psychotic disorders. We examined, in a longitudinal framework, whether baseline momentary assessment markers of stress reactivity would predict persistence of subclinical psychotic experiences over time. In a general population sample of female twins (N = 566, the Experience Sampling Method (ESM; repetitive random sampling of momentary emotions, psychotic experiences and context was used to assess (emotional and psychotic daily life stress reactivity. Persistence of subclinical psychotic experiences was based on the Community Assessment of Psychic Experiences (CAPE, assessed three times over 14 months post-baseline. It was investigated whether baseline daily life emotional and psychotic stress reactivity predicted persistence of psychotic experiences over time. Higher levels of emotional stress reactivity (a decrease in positive and an increase in negative affect in response to stress, and increased psychotic reactivity to daily stress was found in individuals with persistent psychotic experiences over time compared to individuals with transient psychotic experiences. The results suggest that markers of daily life stress reactivity may predict "macro-level" persistence of normally transient expression of psychotic liability over time. Linking daily life markers of altered reactivity in terms of emotions and psychotic experiences to longitudinal persistence of psychotic experiences, associated with increased risk of transition to overt mental disorder, may contribute to earlier and more accurate diagnosis of risk.

  6. Viral marketing as epidemiological model

    CERN Document Server

    Rodrigues, Helena Sofia

    2015-01-01

    In epidemiology, an epidemic is defined as the spread of an infectious disease to a large number of people in a given population within a short period of time. In the marketing context, a message is viral when it is broadly sent and received by the target market through person-to-person transmission. This specific marketing communication strategy is commonly referred as viral marketing. Due to this similarity between an epidemic and the viral marketing process and because the understanding of the critical factors to this communications strategy effectiveness remain largely unknown, the mathematical models in epidemiology are presented in this marketing specific field. In this paper, an epidemiological model SIR (Susceptible- Infected-Recovered) to study the effects of a viral marketing strategy is presented. It is made a comparison between the disease parameters and the marketing application, and simulations using the Matlab software are performed. Finally, some conclusions are given and their marketing impli...

  7. 珠海市将军社区结核病流行病学调查结果与全国第五次结核病流行病学抽样调查结果比对分析%Alignment Analysis of the Results about Zhuhai General Community Tuberculosis Epidemiological Survey and the Fifth National Tuberculosis Epidemiological Survey

    Institute of Scientific and Technical Information of China (English)

    董秋兰; 张璟; 杨睿; 赵金利; 欧青叶

    2012-01-01

    This survey aims to understand the prevalence status and trend of tuberculosis (TB) in Zhuhai general community,evaluate the implementation of Zhuhai TB Control Programme (2001 - 2010) ,and lay the foundation for making the plan of the next five year. According to the survey of the fifth national tuberculosis epidemiology and embodiment, people over 15 years old in sampled survey points of Zhuhai general community were administered symptoms investigation and chest X- ray, received TB knowledge questionnaire. Those with suspected pulmonary TB symptoms or with sus- pected pulmonary TB lesion shown by X-ray were performed sputum smear and culture examination. The results about Zhuhai general community tuberculosis epidemiological survey and the fifth nation- al tuberculosis epidemiological survey are compared and analyzed. This survey has following finding. First,by the implementation of Zhuhai TB Control Programme (2001 - 2010) ,TB patients of Zhuhai general community got effective control,management and treatment. Secondly,the knowledge of tuberculsis's prevention and control of the public is still relatively poor,and it is necessary to carry out health promotion activities targeted diversity and phased.%为了了解珠海市将军社区结核病流行现状和趋势,评价《珠海市结核病防治规划(2001—2010年)》执行情况,为制定珠海市下一个5年规划奠定基础。按照《全国第五次结核病流行病学抽样调查及实施方案》,对将军社区二组≥15岁居民进行症状调查、摄胸片和结核病防治知识知晓情况问卷调查,对可疑患者行痰涂片、痰培养和社会经济情况问卷调查。对将军社区结核病流行病学调查情况同全国第五次结核病流行病学抽样调查结果进行比对分析,发现通过施行《珠海市结核病防治规划(2001—2010年)》,将军社区肺结核病人得到了有效的控制、管理和治疗,但市民的结核病防治知识仍

  8. Increase in sickness absence with psychiatric diagnosis in Norway: a general population-based epidemiologic study of age, gender and regional distribution

    Directory of Open Access Journals (Sweden)

    Brage Sören

    2006-08-01

    Full Text Available Abstract Background The aim of this study was to assess the incidence of sickness absence with psychiatric diagnoses from 1994–2000, and the distribution across gender, age groups, diagnostic groups and regions in a general population. Methods The population at risk was defined as all individuals aged 16–66 years who were entitled to sickness benefits in 1994, 1996, 1998 and 2000 (n = 2,282,761 in 2000. All individuals with a full-time disability pension were excluded. The study included approximately 77% of the Norwegian population aged 16–66 years. For each year, the study base started on 1 January and ended on 31 December. Individuals that were sick-listed for more than 14/16 consecutive days with a psychiatric diagnosis on their medical certificate were selected as cases. Included in this study were data for Norway, the capital city Oslo and five regions in the southeast of the country. Results Sickness absence with psychiatric diagnoses increased in all age groups, in women and men, and in all regions. At the national level, the cumulative incidence increased in women from 1.7% in 1994 to 4.6% in 2000, and in men from 0.8% in 1994 to 2.2% in 2000. The highest cumulative incidence was found in middle-aged women and men (30–59 years. Women had a higher incidence than men in all stratification groups. The cumulative incidences in 2000 varied between 4.6% to 5.6% in women in the different regions, and for men the corresponding figures were 2.1% to 3.2%. Throughout the four years studied, women in Oslo had more than twice as high incidence levels of sickness absence with alcohol and drug diagnoses as the country as a whole. There were some differences between regions in sickness absence with specific psychiatric diagnoses, but they were small and most comparisons were non-significant. Conclusion Sickness absence with psychiatric diagnoses increased between 1994 and 2000 in Norway. The increase was highest in the middle-aged, and in women

  9. Degenerative lumbar spondylolisthesis: an epidemiological perspective: the Copenhagen Osteoarthritis Study

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Sonne-Holm, Stig; Rovsing, Hans;

    2007-01-01

    STUDY DESIGN: A cross-sectional epidemiological survey of 4151 participants of the Copenhagen Osteoarthritis Study. OBJECTIVE: To identify prevalences and individual risk factors for degenerative lumbar spondylolisthesis. SUMMARY OF BACKGROUND DATA: The Copenhagen Osteoarthritis Study has...... registered health parameters since 1976. In 1993, standardized, lateral radiographs of the lumbar spine were recorded. There were 1533 men and 2618 women. METHODS: Statistical correlations were made between degenerative spondylolisthesis, and physical, occupational, and general epidemiological data. RESULTS......: A total of 254 cases of lumbar slip were found (males 2.7%, females 8.4%). In females, no significant relationship between age at menopause or childbirths and the presence of degenerative spondylolisthesis were found. In women, relationships between body mass index (BMI) in 1976 and L4 olisthesis (P = 0...

  10. Hematological Parameters and Hemozoin-Containing Leukocytes and Their Association with Disease Severity among Malaria Infected Children: A Cross-Sectional Study at Pawe General Hospital, Northwest Ethiopia

    Directory of Open Access Journals (Sweden)

    Muluken Birhanu

    2017-01-01

    Full Text Available Hematological parameter changes are the most common complications in malaria. We aimed to determine the hematological parameters and hemozoin-containing leukocytes and their association with disease severity in malaria infected children aged between 1 and 15 years. A facility-based cross-sectional study was conducted at Pawe General Hospital from July 31 to December 30, 2014. Demographic and clinical data were collected using structured questionnaire. Blood specimen was collected from each study participant for hematological investigations. Data were analyzed using SPSS version 20. The overall prevalence of anemia was 40.3%, most of which were mildly anemic. Leukocytosis was found in 15.4% of study participants. More than a fourth (27% of the children had severe malaria. Hemozoin-containing monocytes and neutrophils were found in 80.1% and 58.9% of the study participants, respectively. Under-five years of age (AOR = 3.01, 95% CI: 1.83–7.39, P5% (AOR = 6.26, 95% CI: 2.14–14.29, P5% (AOR = 7.93, 95% CI: 3.09–16.86, P<0.001, and high density parasitemia (AOR = 1.90, 95% CI: 1.13–3.18, P=0.015 were associated with severe malaria. Hemozoin-containing leukocytes, leukocytosis, and other identified associated factors should be considered for proper management of children with severe malaria.

  11. Design of the image detection system for general parts geometric parameters%通用零件几何参数图像检测系统设计

    Institute of Scientific and Technical Information of China (English)

    张建; 温坚; 林菁

    2009-01-01

    Gave image detection system for general parts geometric parameters,the optical lens,industrial digital camera and micro-computer constitute the basic detection system;designed to test preparation,test system to adjust,image acquisition,etreatment,boundary identification,and system parameters to strike a job detect calibration process;described the detection aspect of the role and application of the key questions;designed detect application software;established a detection system,comparison test for typical parts.Gave the detection system is the best and practical.%为实现通用零件几何参数图像检测,采用光学镜头、工业数字摄像机和微型计算机构成基本检测系统,包括测试准备、测试系统调整、图像获取、预处理、边界确定、参数求取和系统标定等检测工作环节.阐述各检测环节的作用和应用中的关键问题、检测应用软件设计.通过所构建的检测系统,对典型零件进行对比测试表明,给出的通用零件几何参数图像检测系统是实用的.

  12. 混合双参数广义Pareto分布的参数估计%Estimation of Parameters of Mixed Generalized Pareto Distribution

    Institute of Scientific and Technical Information of China (English)

    刘媚; 汤银才

    2009-01-01

    Pareto分布族因其厚尾特点,在金融分析、寿命分析中都是非常重要的统汁模型,但是对于混合双参广义Pareto分布,在模型参数估计时,传统的矩法估计和极大似然估计在理论上可以实现,实践时比较困难,本文应用EM算法之ECM算法,研究了混合广义Pareto分布在完全数据场合下的参数估计问题,并模拟说明EM算法来估计混合广义Pareto分布是一种容易实现又非常有效的方法.%Generalized Pareto distribution plays an important role in financial and life time data analysis for its fat-tailed. However we may encounter enormous difficulties when we try to estimate the model by traditional methods such as maximize likelihood (ML) estimation and moment estimation, though they make sense theoretically. In this paper, we employ ECM algorithm of an extension EM algorithm to obtain the parameter estimation for the mixed Generalized Pareto model with complete sample. Simulations are also made to demonstrate the efficiency of this estimation.

  13. Inapplicability of exact constraints and a minimal two-parameter generalization to the DFT+U based correction of self-interaction error

    Science.gov (United States)

    Moynihan, Glenn; Teobaldi, Gilberto; O'Regan, David D.

    2016-12-01

    In approximate density-functional theory (DFT), the self-interaction error is an electron delocalization anomaly associated with underestimated insulating gaps. It exhibits a predominantly quadratic energy-density curve that is amenable to correction using efficient, constraint-resembling methods such as DFT + Hubbard U (DFT+U ). Constrained DFT (cDFT) enforces conditions on DFT exactly, by means of self-consistently optimized Lagrange multipliers, and while its use to automate error corrections is a compelling possibility, we show that it is limited by a fundamental incompatibility with constraints beyond linear order. We circumvent this problem by utilizing separate linear and quadratic correction terms, which may be interpreted either as distinct constraints, each with its own Hubbard U type Lagrange multiplier, or as the components of a generalized DFT+U functional. The latter approach prevails in our tests on a model one-electron system, H2+ , in that it readily recovers the exact total energy while symmetry-preserving pure constraints fail to do so. The generalized DFT+U functional moreover enables the simultaneous correction of the total energy and ionization potential, or the correction of either together with the enforcement of Koopmans' condition. For the latter case, we outline a practical, approximate scheme by which the required pair of Hubbard parameters, denoted as U1 and U2, may be calculated from first principles.

  14. Estudio epidemiológico de las urgencias en cirugía oral y maxilofacial en un hospital general Epidemiological study of oral and maxillofacial emergencies in a general hospital

    Directory of Open Access Journals (Sweden)

    B. Peral Cagigal

    2004-12-01

    Full Text Available Objetivo. La demanda de asistencia en los Servicios de Urgencias Hospitalarias está en constante crecimiento desde hace varias décadas y en especial en la Cirugía Maxilofacial. El objetivo de este estudio es realizar un análisis epidemiológico de las urgencias que se producen en dicha especialidad. Diseño del estudio. Estudio transversal y observacional de pacientes atendidos por Cirugía Maxilofacial en el Servicio de Urgencias del Hospital Río Hortega de Valladolid durante el año 2002. Se analizaron 1.970 pacientes y 10 variables. Resultados. Se atendieron 1.970 pacientes, de los cuales el 55,8% fueron hombres. La mayor presión asistencial se produjo en domingo (15,8% y en el mes de junio (10,9%. El rango de edad con mayor demanda asistencial fue de los 0 a los 10 años (22,6%. La etiología más común por la que los pacientes fueron atendidos resultaron ser los accidentes (55,1% y el grupo diagnóstico los traumatismos (55,6%. El tipo de tratamiento inmediato más frecuente fue el médico (58,5%. Fueron ingresados el 9,4% de los pacientes y revisados en consulta un 33,1%. El 90,3% de los pacientes pertenecían al área del hospital. Conclusiones. El rango de edad más frecuente de los pacientes atendidos es de 0 a 10 años y la mayoría de los pacientes que acuden a urgencias son hombres. El día con mayor presión asistencial es el domingo y el mes con mayor número de urgencias y de ingresos es junio. La etiología por la que acuden más frecuentemente a urgencias son los accidentes y la traumatología configura la patología maxilofacial con mayor demanda de atención urgente en nuestro hospital. El tratamiento más frecuente es el médico.Objective. The demand placed on emergency care units continues to increase at a growing rate, in special Maxillofacial Surgery. The objective of the study is to perform an epidemiological analyses in the emergency maxillofacial area. Design. Transversal observational study of the patients

  15. Networks and the Epidemiology of Infectious Disease

    CERN Document Server

    Danon, Leon; House, Thomas; Jewell, Chris P; Keeling, Matt J; Roberts, Gareth O; Ross, Joshua V; Vernon, Matthew C

    2010-01-01

    The science of networks has revolutionised research into the dynamics of interacting elements. It could be argued that epidemiology in particular has embraced the potential of network theory more than any other discipline. Here we review the growing body of research concerning the spread of infectious diseases on networks, focusing on the interplay between network theory and epidemiology. The review is split into four main sections, which examine: the types of network relevant to epidemiology; the multitude of ways these networks can be characterised; the statistical methods that can be applied to infer the epidemiological parameters on a realised network; and finally simulation and analytical methods to determine epidemic dynamics on a given network. Given the breadth of areas covered and the ever-expanding number of publications, a comprehensive review of all work is impossible. Instead, we provide a personalised overview into the areas of network epidemiology that have seen the greatest progress in recent ...

  16. [Ways of urban sanitary and epidemiological well-being management].

    Science.gov (United States)

    Kreĭmer, M A

    2010-01-01

    The scientific rationale for preventive measures based on sanitary-and-epidemiological surveillance on environmental objects is considered. The sizes of functional zones and space for various types of communal services and amenities and leisure are regulated to ensure good urban vital activities. Multistorey housing causes an increase in the number of negative factors per area units and in their impact on health. A proposal has been made for the standardization of the ranges of urban population upsurge and size, by using the sanitary-and-hygienic rules and norms rather than climatic parameters. A criterion system for assessing the data of statistical observations has been substantiated and 5 levels of analysis and managerial decision-making have been proposed. Cause-and-effect relations may be determined for the parameters of the second level; models of program-oriented studies for the third level, only sanitary-and-epidemiological surveillance is possible for the fourth and fifth levels. The space planning scheme must provide for water supply reserves, generation areas for pure air coming into the town, and waste disposal areas. The general layout may use statistical observation parameters characterizing the second level of occurrence of negative phenomena. The statistical observation parameters characterizing the third and fourth levels of occurrence of negative phenomena may be used for municipal improvements and sanitary maintenance. These characterizing the fourth and fifth level may be used for prevention in therapeutic-and-prophylactic institutions.

  17. International Lymphoma Epidemiology Consortium

    Science.gov (United States)

    The InterLymph Consortium, or formally the International Consortium of Investigators Working on Non-Hodgkin's Lymphoma Epidemiologic Studies, is an open scientific forum for epidemiologic research in non-Hodgkin's lymphoma.

  18. Ehrlichiosis: Statistics and Epidemiology

    Science.gov (United States)

    ... a tick Diseases transmitted by ticks Statistics and Epidemiology Recommend on Facebook Tweet Share Compartir On this ... Holman RC, McQuiston JH, Krebs JW, Swerdlow DL. Epidemiology of human ehrlichiosis and anaplasmosis in the United ...

  19. [General epidemiology of invasive fungal disease].

    Science.gov (United States)

    Pemán, Javier; Salavert, Miguel

    2012-02-01

    Invasive mycoses associated with high morbidity and mortality rates are increasing among immunocompromised or severely ill patients. Candida, Cryptococcus, Pneumocystis and Aspergillus are most prevalent agents with varying distribution as regards geography, patient condition and hospital units. The latest multicentre candidaemia survey conducted in Spain, showed C. albicans as the most frequently isolated species followed by C. parapsilosis, C. glabrata, C. tropicalis and C. krusei in contrast with other European or American studies where C. glabrata was second in rank. Aspergillus spp. is the leading agent causing invasive mycoses among filamentous fungi followed by Fusarium spp., Scedosporium spp. and zygomycetes. Aspergillus fumigatus is the most common agent in invasive aspergillosis (and azole-resistant isolates have been reported) but in the last few years Aspergillus flavus, Aspergillus nidulans and Aspergillus terreus have been isolated with increasing frequency variable with geographical factors, patients' underlying conditions or previous antifungal treatments.

  20. [Dermato-epidemiology].

    Science.gov (United States)

    Apfelbacher, C J; Diepgen, T L; Weisshaar, E

    2011-11-01

    Dermato-epidemiology is an important scientific discipline which investigates skin diseases using epidemiological methods. Epidemiology is the science of the distribution and determinants of disease in specified populations. We describe fundamental terms of dermato-epidemiology (measures of disease occurrence, measures of risk), different study types (observational studies, interventional studies), the selection of statistical tests, bias and confounding as well as the principles of evidence-based dermatology, and give illustrative examples.

  1. Parameter Estimation of Generalized Partial Probability Weighted Moments for the Generalized Pareto Distribution%广义Pareto分布的广义有偏概率加权矩估计方法

    Institute of Scientific and Technical Information of China (English)

    赵旭; 程维虎; 李婧兰

    2012-01-01

    The generalized Pareto distribution (GPD) is one of the most important distribution in statistics analysis that has been widely used in finance, insurance, hydrology and meteorology applications and so on. While traditional estimation methods, such as maximum likelihood (ML), methods of moments (MOM) and probability weighted moments (PWM) methods have been extensively applied, the use of these methods are often restricted. Alternative approaches (e.g., generalized probability weighted moments, L-moments and LH-moments) exist but they use complete or non-censored samples. However, censored samples are often encountered in hydrology and meteorology fields. In this article, we propose a computationally easy method from censored data for fitting the GPD, which is resistant against extremely small or large outliers, I.e., they will be robust with the lower and upper breakdown points. This method is based on probability weighted moments. Firstly, we solve shape parameter estimator which has high estimated precision, then the location and scale parameters are given for the GPD. Simulation studies show that the proposed method performs well compared to traditional techniques.%广义Pareto分布(GPD)是统计分析中一个极为重要的分布,被广泛应用于金融、保险、水文及气象等领域.传统的参数估计方法如极大似然估计、矩估计及概率加权矩估计方法等已被广泛应用,但使用中存在一定的局限性.虽然提出很多改进方法如广义概率加权矩估计、L矩和LH矩法等,但都是研究完全样本的估计问题,而在水文及气象等应用领域常出现截尾样本.本文基于概率加权矩理论,利用截尾样本对三参数GPD提出一种应用范围广且简单易行的参数估计方法,可有效减弱异常值的影响.首先求解出具有较高精度的形状参数的参数估计,其次得出位置参数及尺度参数的参数估计.通过Monte Carlo模拟说明该方法估计精度较高.

  2. Epidemiology of Lyme Disease

    Directory of Open Access Journals (Sweden)

    Dennis J White

    1991-01-01

    Full Text Available Investigation of the epidemiology of Lyme disease depends upon information generated from several sources. Human disease surveillance can be conducted by both passive and active means involving physicians, public health agencies and laboratories. Passive and active tick surveillance programs can document the extent of tick-borne activity, identify the geographic range of potential vector species, and determine the relative risk of exposure to Lyme disease in specific areas. Standardized laboratory services can play an important role in providing data. Epidemiologists can gain a better understanding of Lyme disease through the collection of data from such programs. The interpretation of data and provision of information to the medical and general communities are important functions of public health agencies.

  3. Cancer Epidemiology Matters Blog

    Science.gov (United States)

    The Cancer Epidemiology Matters blog helps foster a dialogue between the National Cancer Institute's (NCI) Epidemiology and Genomics Research Program (EGRP), extramural researchers, and other individuals, such as clinicians, community partners, and advocates, who are interested in cancer epidemiology and genomics.

  4. Multi-band gravitational-wave astronomy: parameter estimation and tests of general relativity with space and ground-based detectors

    CERN Document Server

    Vitale, Salvatore

    2016-01-01

    With the discovery of the black hole binary (BBH) coalescence GW150914 the era of gravitational-wave (GW) astronomy has started. It has recently been shown that BBH with masses comparable to or higher than GW150914 would be visible in the eLISA band a few years before they finally merge in the band of ground-based detectors. This would allow for pre-merger electromagnetic alerts, dramatically increasing the chances of a joint detection, if BBH are indeed luminous in the electromagnetic band. In this paper we explore a quite different aspect of multi-band GW astronomy, and verify if, and to what extent, measurement of masses and sky position with eLISA could improve parameter estimation and tests of general relativity with ground-based detectors. We generate a catalog of 200 BBH and find that having prior information from eLISA can reduce the uncertainty in the measurement of source distance and primary black hole spin by up to factor of 2 in ground-based GW detectors. The component masses estimate from eLISA ...

  5. An animated depiction of major depression epidemiology

    Directory of Open Access Journals (Sweden)

    Patten Scott B

    2007-06-01

    Full Text Available Abstract Background Epidemiologic estimates are now available for a variety of parameters related to major depression epidemiology (incidence, prevalence, etc.. These estimates are potentially useful for policy and planning purposes, but it is first necessary that they be synthesized into a coherent picture of the epidemiology of the condition. Several attempts to do so have been made using mathematical modeling procedures. However, this information is not easy to communicate to users of epidemiological data (clinicians, administrators, policy makers. Methods In this study, up-to-date data on major depression epidemiology were integrated using a discrete event simulation model. The mathematical model was animated in Virtual Reality Modeling Language (VRML to create a visual, rather than mathematical, depiction of the epidemiology. Results Consistent with existing literature, the model highlights potential advantages of population health strategies that emphasize access to effective long-term treatment. The paper contains a web-link to the animation. Conclusion Visual animation of epidemiological results may be an effective knowledge translation tool. In clinical practice, such animations could potentially assist with patient education and enhanced long-term compliance.

  6. Automated spatial and thematic generalization using a context transformation model: integrating steering parameters, classification and aggregation hierarchies, reduction factors, and topological structures for multiple abstractions.

    NARCIS (Netherlands)

    Richardson, D.E.

    1993-01-01

    This dissertation presents a model for spatial and thematic digital generalization. To do so, the development of digital generalization over the last thirty years is first reviewedThe approach to generalization taken in this research differs from other existing works as it tackles the task from a da

  7. Mapping epidemiology's past to inform its future: metaknowledge analysis of epidemiologic topics in leading journals, 1974-2013.

    Science.gov (United States)

    Trinquart, Ludovic; Galea, Sandro

    2015-07-15

    An empiric perspective on what epidemiology has studied over time might inform discussions about future directions for the discipline. We aimed to identify the main areas of epidemiologic inquiry and determine how they evolved over time in 5 high-impact epidemiologic journals. We analyzed the titles and abstracts of 20,895 articles that were published between 1974 and 2013. In 5 time periods that reflected approximately equal numbers of articles, we identified the main topics by clustering terms based on co-occurrence. Infectious disease and cardiovascular disease epidemiology were the prevailing topics over the 5 periods. Cancer epidemiology was a major topic from 1974 to 2001 but disappeared thereafter. Nutritional epidemiology gained relative importance from 1974 to 2013. Environmental epidemiology appeared during 1996-2001 and continued to be important, whereas 2 clusters related to methodology and meta-analysis in genetics appeared during 2008-2013. Several areas of epidemiology, including injury or psychiatric epidemiology, did not make an appearance as major topics at any time. In an ancillary analysis of 6 high-impact general medicine journals, we found patterns of epidemiologic articles that were overall consistent with the findings in epidemiologic journals. This metaknowledge investigation allowed identification of the dominant topics in and conversely those that were absent from 5 major epidemiologic journals. We discuss implications for the field.

  8. 中山市27062例体检人群EB病毒感染状况的临床调查研究%Clinical epidemiological investigation on EBV infection status in the general population in Zhongshan City

    Institute of Scientific and Technical Information of China (English)

    张丽娟; 周小军

    2011-01-01

    Objective To investigate the EB vims (EBV) infection status in the general population of Zhongshan City, Guangdong province, where with a very higher incidence of nasopharyngeal carcinoma (NPC), based on a clinical epidemiological study. Method Investigated in this study were 27 062 local people for healih care examination in our Hospital from January 2007 to December 2008, with their ill history recorded and serum samples collected for determination of EBV-associated antibodies assayed by the procedures of enzvme-. Labeled immunosorbent assay (ELISA). Then, an analysis was made on the infecting rates of EBV among different gender and different populations at various age subgroups, with a special focus on the relative risk ratio of EBV infection rate in a special age subgroup. Results In this group of studied population, the total EBV infection rate was 1.09%, with such a rate being 1.33% in male and 0.73% in female subgroups (x2=21.8522,P<0.01). People at the two subgroups of age from 50 to 59 and 60 to 69 years old showed that the EBV infection rates were significantly higher than those among other subgroups of age from 20 to 29, 30 to 39, and 40 to 49 years old respectively, with statistical significance among them (P<0.05), suggesting that the middle-aged and older people having a higher risk of EBV infection. Conclusions EBV infection rate is 1.09% in the general population in Zhongshan City, where the incidence of NPC is much higher, with a much increased risk of EBV infection in male than in female. It is also true for a much higher risk of EBV infection among the middle-aged and older persons (50 to 69-year-old) in the general population. So, intensive health care should be given to the people at these subgroups of age regarding the prevention and treatment of EBV infection.%目的 对鼻咽癌高发区广东省中山市普通人群EB病毒感染状况进行临床流行病学调查.方法 收集中山市中医院保健中心2007年1月~2008年12

  9. Modeling Corporate Epidemiology

    CERN Document Server

    Waber, Benjamin; Cebrian, Manuel; Crane, Riley; Danon, Leon; Pentland, Alex

    2010-01-01

    Corporate responses to illness is currently an ad-hoc, subjective process that has little basis in data on how disease actually spreads at the workplace. Additionally, many studies have shown that productivity is not an individual factor but a social one: in any study on epidemic responses this social factor has to be taken into account. The barrier to addressing this problem has been the lack of data on the interaction and mobility patterns of people in the workplace. We have created a wearable Sociometric Badge that senses interactions between individuals using an infra-red (IR) transceiver and proximity using a radio transmitter. Using the data from the Sociometric Badges, we are able to simulate diseases spreading through face-to-face interactions with realistic epidemiological parameters. In this paper we construct a curve trading off productivity with epidemic potential. We are able to take into account impacts on productivity that arise from social factors, such as interaction diversity and density, wh...

  10. Optimization of GATE and PHITS Monte Carlo code parameters for spot scanning proton beam based on simulation with FLUKA general-purpose code

    Energy Technology Data Exchange (ETDEWEB)

    Kurosu, Keita [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Department of Radiology, Osaka University Hospital, Suita, Osaka 565-0871 (Japan); Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Moskvin, Vadim P. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Department of Radiation Oncology, St. Jude Children’s Research Hospital, Memphis, TN 38105 (United States)

    2016-01-15

    Spot scanning, owing to its superior dose-shaping capability, provides unsurpassed dose conformity, in particular for complex targets. However, the robustness of the delivered dose distribution and prescription has to be verified. Monte Carlo (MC) simulation has the potential to generate significant advantages for high-precise particle therapy, especially for medium containing inhomogeneities. However, the inherent choice of computational parameters in MC simulation codes of GATE, PHITS and FLUKA that is observed for uniform scanning proton beam needs to be evaluated. This means that the relationship between the effect of input parameters and the calculation results should be carefully scrutinized. The objective of this study was, therefore, to determine the optimal parameters for the spot scanning proton beam for both GATE and PHITS codes by using data from FLUKA simulation as a reference. The proton beam scanning system of the Indiana University Health Proton Therapy Center was modeled in FLUKA, and the geometry was subsequently and identically transferred to GATE and PHITS. Although the beam transport is managed by spot scanning system, the spot location is always set at the center of a water phantom of 600 × 600 × 300 mm{sup 3}, which is placed after the treatment nozzle. The percentage depth dose (PDD) is computed along the central axis using 0.5 × 0.5 × 0.5 mm{sup 3} voxels in the water phantom. The PDDs and the proton ranges obtained with several computational parameters are then compared to those of FLUKA, and optimal parameters are determined from the accuracy of the proton range, suppressed dose deviation, and computational time minimization. Our results indicate that the optimized parameters are different from those for uniform scanning, suggesting that the gold standard for setting computational parameters for any proton therapy application cannot be determined consistently since the impact of setting parameters depends on the proton irradiation

  11. [Epidemiology and public policies].

    Science.gov (United States)

    Barata, Rita Barradas

    2013-03-01

    The present essay deals with the relation between epidemiology and public policies, highlighting the epidemiology position in the public health field, analyzing the impact of public policies over epidemiological profile and contributions from epidemiology to the lay down, implementation and evaluation of public health policies. In the first title, the essay debates the links between the epidemiology and public health field, the social determinants and political action framework proposed by the WHO's Commission on Social Determinants of Health, and different approaches of health policies. In the second title the essay analyses the reduction of child stunting in Brazil as an example of public policies that impact epidemiological profile. The third title presents three strategic topics for the application of public health policies: reduction of social inequalities in health, health promotion and regulation of products and services that have impact over health. The fourth title discusses the possibilities and difficulties to combine the epidemiological knowledge in the lay down, implementation and evaluation of public policies and, finally, material examples of such relation between epidemiology and public policies are presented.

  12. The future of epidemiology.

    Science.gov (United States)

    Ness, Roberta B; Andrews, Elizabeth B; Gaudino, James A; Newman, Anne B; Soskolne, Colin L; Stürmer, Til; Wartenberg, Daniel E; Weiss, Stanley H

    2009-11-01

    In this article, the authors discuss current challenges and opportunities in epidemiology that will affect the field's future. Epidemiology is commonly considered the methodologic backbone for the fields of public health and outcomes research because its practitioners describe patterns of disease occurrence, identify risk factors and etiologic determinants, and demonstrate the usefulness of interventions. Like most aspects of science, epidemiology is in rapid flux. Several factors that are influencing and will continue to influence epidemiology and the health of the public include factors fundamental to framing the discipline of epidemiology (i.e., its means of communication, its methodologies, its access to data, its values, its population perspective), factors relating to scientific advances (e.g., genomics, comparative effectiveness in therapeutics), and factors shaping human health (e.g., increasing globalism, the environment, disease and lifestyle, demographics, infectious disease).

  13. Radiobiology and Epidemiology

    Energy Technology Data Exchange (ETDEWEB)

    Desaintes, C; Holmstock, L

    2001-04-01

    The main objectives of research in the field of radiobiology and epidemiology performed at the Belgian Nuclear Research Centre SCK-CEN are: (1) to study cancer mortality in nuclear workers in Belgium and to co-ordinate the Belgian contribution to the 'International Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry'; (2) to elucidate the molecular basis of individual susceptibility to ionizing radiation in mammalian embryo during the early phases of its development; (3) to assess the genetic risk of maternal exposure to ionizing radiation; (4) to elucidate the cellular mechanisms leading to brain damage after prenatal irradiation; (5) to monitor the early variations of gene expression induced by ionising radiation and cytokines; (6) to evaluate the use of cytokines and natural substances for improving radiotherapy protocols; (6) to advise authorities and to provide the general population with adequate information concerning the health risk arising from radiation exposure. Progress and major achievements in these topical areas in 2000 are reported.

  14. PROBABILITY SAMPLING DESIGNS FOR VETERINARY EPIDEMIOLOGY

    OpenAIRE

    Xhelil Koleci; Coryn, Chris L.S.; Kristin A. Hobson; Rruzhdi Keci

    2011-01-01

    The objective of sampling is to estimate population parameters, such as incidence or prevalence, from information contained in a sample. In this paper, the authors describe sources of error in sampling; basic probability sampling designs, including simple random sampling, stratified sampling, systematic sampling, and cluster sampling; estimating a population size if unknown; and factors influencing sample size determination for epidemiological studies in veterinary medicine.

  15. Welcome to epidemiology and health.

    Science.gov (United States)

    Choi, Bo Youl

    2009-10-29

    The Korean Society of Epidemiology publishes a scholarly journal titled 'Korean Journal of Epidemiology', which announces and discusses the results of epidemiological studies from the past 30 yr. Since its first publication in 1979, the journal has contributed to the advancement of epidemiology as well as the prevention and control of disease, and the promotion of health in Korea.In 2009, the editorial board has decided to publish the journal in English to contribute internationally, and change the journal's name. The new name of the journal is 'Epidemiology and Health'.The abstract and full text of articles will be published as an open access online journal, which will be posted onto the homepage (http://www.e-epih.org/) in real time for anyone in the world to access free of charge. Our editorial policy is that 'Epidemiology and Health' is open to every researcher in fields related to epidemiology, regardless of membership, his or her major and nationality.Editorials, lectures, review papers, original articles, epidemic and case investigations, brief communications and letters will be published to generate active discussion through the journal along with the publication of the papers.'Epidemiology and Health' welcomes articles from various fields of epidemiology, such as 1) infectious diseases epidemiology, 2) chronic diseases epidemiology, 3) nutritional epidemiology, 4) clinical epidemiology, 5) pharmacoepidemiology, 6) genetic or molecular epidemiology, 7) social epidemiology, 8) environmental or occupational epidemiology, 9) epidemiological methods and biostatistics, 10) disease prevention and control, 11) health promotion and, 12) all other fields related to epidemiology.

  16. La epidemiología ocupacional como herramienta básica para la salud de los trabajadores Occupational epidemiology as a basic tool for workers' health

    Directory of Open Access Journals (Sweden)

    Caristina Robaina Aguirre

    2006-06-01

    Full Text Available Se realizó un pequeño bosquejo del desarrollo de la Epidemiología como ciencia y su importancia en salud pública en general. Se transita por las definiciones de vieja y nueva epidemiología, de enfermedades crónicas, transmisibles y no transmisibles, del concepto de epidemiología social, etc. para posteriormente hablar de la importancia de la Epidemiología Ocupacional en la Salud PúblicaA review of the development of Epidemiology as a science, and its significance in public health in general, was made. The old and new definitions of epidemiology, of chronic, transmissible and non-transmissible diseases, of social epidemiology concept, etc., are analysed to further deal with the importance of Occupational Epidemiology in Public Health.

  17. Associations of common variants in HFE and TMPRSS6 with iron parameters are independent of serum hepcidin in a general population: a replication study

    NARCIS (Netherlands)

    Galesloot, T.E.; Geurts-Moespot, A.; Heijer, M. den; Sweep, F.C.; Fleming, R.E.; Kiemeney, L.A.L.M.; Vermeulen, S.; Swinkels, D.W.

    2013-01-01

    BACKGROUND: Genome-wide association studies have convincingly shown that single nucleotide polymorphisms (SNPs) in HFE and TMPRSS6 are associated with iron parameters. It was commonly thought that these associations could be explained by the intermediate effect on hepcidin concentration. A recent

  18. Epidemiology of recurrent venous thrombosis

    Directory of Open Access Journals (Sweden)

    D.D. Ribeiro

    2012-01-01

    Full Text Available Venous thrombosis, including deep vein thrombosis and pulmonary embolism, is a common disease that frequently recurs. Recurrence can be prevented by anticoagulants, but this comes at the risk of bleeding. Therefore, assessment of the risk of recurrence is important to balance the risks and benefits of anticoagulant treatment. This review briefly outlines what is currently known about the epidemiology of recurrent venous thrombosis, and focuses in more detail on potential new risk factors for venous recurrence. The general implications of these findings in patient management are discussed.

  19. Epidemiology of Autoimmune Bullous Diseases

    Directory of Open Access Journals (Sweden)

    Erkan Alpsoy

    2011-06-01

    Full Text Available We have very limited knowledge about aotuimmune bullous disesases which are important causes of morbidity and mortality. They are generally rare disases in population. The yearly over all incidences of pemphigus and bullous pemhigoid are between 0.5 to 16.1/million and 2.5 to 42.8/million, respectively. Pemphigus vulgaris is the major type of pemphigus and it is most prevalent between ages of 40 and 50. Bullous pemphigoid is tpypically most prevalent in ages of over 70. In this review the results obtained from the studies which are especially about epidemiology of pemphigus and bullous pemphigoid were analised according to geographic regions.

  20. The epidemiology of contact allergy. Allergen exposure and recent trends

    DEFF Research Database (Denmark)

    Thyssen, J P

    2009-01-01

    Contact allergy is frequent among dermatitis patients and subjects in the general population. This review aims to update the reader on the epidemiology of contact allergy epidemics. It presents recent epidemiological data on metals, fragrances, hair dyes, preservatives and thiurams. It concludes ...

  1. Evolution and social epidemiology.

    Science.gov (United States)

    Nishi, Akihiro

    2015-11-01

    Evolutionary biology, which aims to explain the dynamic process of shaping the diversity of life, has not yet significantly affected thinking in social epidemiology. Current challenges in social epidemiology include understanding how social exposures can affect our biology, explaining the dynamics of society and health, and designing better interventions that are mindful of the impact of exposures during critical periods. I review how evolutionary concepts and tools, such as fitness gradient in cultural evolution, evolutionary game theory, and contemporary evolution in cancer, can provide helpful insights regarding social epidemiology.

  2. 基于Kramers逃逸速率的Dung振子广义调参随机共振研究%Generalized parameter-adjusted sto chastic resonance of Duffing oscillator based on Kramers rate

    Institute of Scientific and Technical Information of China (English)

    冷永刚; 赖志慧

    2014-01-01

    The stochastic resonance (SR) of two-dimensional Duffing oscillator is studied in this paper. We propose the generalized parameter-adjustment SR of Duffing oscillator. On the basis of Kramers rate, we build a discrimination function of the SR of Duffing oscillator, and we expound the generalized parameter-adjustment SR laws of Duffing oscil-lator under different noise intensity and signal frequency conditions. The general method of generating the generalized parameter-adjustment SR of Duffing oscillator is also given in this paper.%以二维Duffing振子的随机共振为研究对象,提出Duffing振子的广义调参随机共振。以Kramers逃逸速率为基础,建立了Duffing振子随机共振的判别函数,阐述了Duffing振子在不同噪声强度及信号频率输入条件下的广义调参随机共振规律,并给出了Duffing振子广义调参随机共振的一般方法。

  3. Mathematical and statistical approaches to AIDS epidemiology

    CERN Document Server

    1989-01-01

    The 18 research articles of this volume discuss the major themes that have emerged from mathematical and statistical research in the epidemiology of HIV. The opening paper reviews important recent contributions. Five sections follow: Statistical Methodology and Forecasting, Infectivity and the HIV, Heterogeneity and HIV Transmission Dynamics, Social Dynamics and AIDS, and The Immune System and The HIV. In each, leading experts in AIDS epidemiology present the recent results. Some address the role of variable infectivity, heterogeneous mixing, and long periods of infectiousness in the dynamics of HIV; others concentrate on parameter estimation and short-term forecasting. The last section looks at the interaction between the HIV and the immune system.

  4. Determination of the correlation relationship of pedagogical tests of general physical training with a set of parameters describing the morphological features and canoeists.

    Directory of Open Access Journals (Sweden)

    Flerchuk Viktor Viktorovich

    2011-09-01

    Full Text Available Correlation connections of tests are certain to on general physical preparation with indexes morphological possibilities of sportsmen. 15 sportsmen took part in research. Propensity of sportsmen is set to certain distances in competition activity. Directions of selection and orientation of sportsmen are recommended to work of different orientation.

  5. Cancer Epidemiology Cohorts

    Science.gov (United States)

    Cohort studies are fundamental for epidemiological research by helping researchers better understand the etiology of cancer and provide insights into the key determinants of this disease and its outcomes.

  6. Epidemiology & Genomics Research Program

    Science.gov (United States)

    The Epidemiology and Genomics Research Program, in the National Cancer Institute's Division of Cancer Control and Population Sciences, funds research in human populations to understand the determinants of cancer occurrence and outcomes.

  7. Occupational cancer epidemiology.

    Science.gov (United States)

    Boffetta, Paolo

    2011-01-01

    Occupational cancer epidemiology has led to the identification of more than 40 agents, groups of agents, and exposure circumstances which cause cancer in humans. This evidence has been followed by preventive and control measures. There are four areas where occupational cancer epidemiology may contribute important results in the future: surveillance of workers exposed to carcinogens, identification of new carcinogens and target organs, study of interactions, and research on special exposure circumstances.

  8. An introduction to epidemiologic and statistical methods useful in environmental epidemiology.

    Science.gov (United States)

    Nitta, Hiroshi; Yamazaki, Shin; Omori, Takashi; Sato, Tosiya

    2010-01-01

    Many developments in the design and analysis of environmental epidemiology have been made in air pollution studies. In the analysis of the short-term effects of particulate matter on daily mortality, Poisson regression models with flexible smoothing methods have been developed for the analysis of time-series data. Another option for such studies is the use of case-crossover designs, and there have been extensive discussions on the selection of control periods. In the Study on Respiratory Disease and Automobile Exhaust project conducted by the Japanese Ministry of the Environment, we adopted a new 2-stage case-control design that is efficient when both exposure and disease are rare. Based on our experience in conducting air pollution epidemiologic studies, we review 2-stage case-control designs, case-crossover designs, generalized linear models, generalized additive models, and generalized estimating equations, all of which are useful approaches in environmental epidemiology.

  9. Study of Hematological Parameters in Children Suffering from Iron Deficiency Anaemia in Chattagram Maa-o-Shishu General Hospital, Chittagong, Bangladesh

    Directory of Open Access Journals (Sweden)

    Abu Syed Mohammed Mujib

    2014-01-01

    Full Text Available A total of 150 (30.61% anemic patients out of 490 patients diagnosed to have iron deficiency anemia (IDA have been selected for the first time in Bangladesh. For detailed study, blood samples from 150 anemic patients along with 25 controls were analyzed. Analysis of variance showed significant P value between mean platelet volume (MPV in females (8.08 μm3 and males (7.59 μm3 (P<0.05 in iron deficiency anemia patients. Besides, the value of white blood cells (WBC in males (10946.08/cmm was significantly higher than in females (9470.833/cmm (P<0.05. The significant correlation was observed among hemoglobin levels with hematocrits, hemoglobin with RBC, RBC with hematocrits, and MCV with MCH as well as MCH with MCHC. However, the negative correlation was observed between the hematological variables neutrophils and lymphocytes (r=-0.989. The common complaints we have found in the survey were weight loss 73.33%, attention problem 68%, dyspepsia 65%, decrease of appetite 72%, weakness 68%, diarrhea 65%, and headache 55% among IDA patients. ANOVA showed significant statistical difference in all the hematological and biochemical parameters. Analysis of variance test between anemias with only one of three biochemical parameters decreased and control showed that this group does not have iron deficiency.

  10. Efficient computation of the maximum a posteriori path and parameter estimation in integrate-and-fire and more general state-space models.

    Science.gov (United States)

    Koyama, Shinsuke; Paninski, Liam

    2010-08-01

    A number of important data analysis problems in neuroscience can be solved using state-space models. In this article, we describe fast methods for computing the exact maximum a posteriori (MAP) path of the hidden state variable in these models, given spike train observations. If the state transition density is log-concave and the observation model satisfies certain standard assumptions, then the optimization problem is strictly concave and can be solved rapidly with Newton-Raphson methods, because the Hessian of the loglikelihood is block tridiagonal. We can further exploit this block-tridiagonal structure to develop efficient parameter estimation methods for these models. We describe applications of this approach to neural decoding problems, with a focus on the classic integrate-and-fire model as a key example.

  11. General scan in flavor parameter space in models with vector quark doublets and an enhancement in the B → Xsγ process

    Science.gov (United States)

    Wang, Wenyu; Xiong, Zhao-Hua; Zhao, Xin-Yan

    2016-09-01

    In models with vector-like quark doublets, the mass matrices of up and down type quarks are related. Precise diagonalization of the mass matrices has become an obstacle in numerical studies. In this work we first propose a diagonalization method. As its application, in the Standard Model with one vector-like quark doublet we present the quark mass spectrum and Feynman rules for the calculation of B → Xsγ. We find that i) under the constraints of the CKM matrix measurements, the mass parameters in the bilinear term are constrained to a small value by the small deviation from unitarity; ii) compared with the fourth generation extension of the Standard Model, there is an enhancement to the B → Xsγ process in the contribution of vector-like quarks, resulting in a non-decoupling effect in such models. Supported by Natural Science Foundation of China (11375001) and Talents Foundation of Education Department of Beijing

  12. General scan in flavor parameter space in the models with vector quark doublets and an enhancement in $B\\to X_s\\gamma$ process

    CERN Document Server

    Wang, Wenyu; Zhao, Xin-Yan

    2016-01-01

    In the models with vector like quark doublets, the mass matrices of up and down type quarks are related. Precise diagonalization for the mass matrices became an obstacle in the numerical studies. In this work we propose a diagonalization method at first. As its application, in the standard model with one vector like quark doublet we present quark mass spectrum, Feynman rules for the calculation of $B\\to X_s\\gamma$. We find that i) under the constraints of the CKM matrix measurements, the mass parameters in the bilinear term are constrained to a small value by the small deviation from unitarity; ii) compared with the fourth generation extension of the standard model, there is an enhancement to $B\\to X_s\\gamma$ process in the contribution of vector like quark, resulting a non-decoupling effect in such models.

  13. The associations between atrial fibrillation and parameters of nutritional status assessment in the general hospital population - a cross-sectional analysis of medical documentation.

    Science.gov (United States)

    Budzyński, Jacek; Anaszewicz, Marzena

    2017-01-01

    Atrial fibrillation (AF) and nutrition status abnormalities are two of the most significant epidemics in current health care. The aim of this study was to determine the relationship between the prevalence and outcome of AF, and the parameters of nutritional status among consecutive, real-life patients hospitalised in a university hospital. Analysis of the medical documentation of 4930 consecutive patients aged ≥ 18 years hospitalised for more than one day with diagnoses of cardiovascular disorders. Patients admitted with a diagnosis of AF (n = 512) compared to their counterparts without AF less frequently had an NRS-2002 score ≥ 3, normal range of body mass index (BMI), higher blood haemoglobin, and lower low density lipoprotein cholesterol (LDL-C) concentration. In logistic regression analysis, the risk of a hospitalisation due to AF was negatively related to BMI, NRS-2002 score, and the value of the difference between ideal and actual body mass. Urgent admission and having an NRS-2002 score ≥ 3 remained the only significant variables determining the risk of in-hospital death. Blood concentration of LDL-C and urgent admission were the only significant variables determining risk of 30-day rehospitalisation in the studied population. Inpatients with AF had a lower prevalence of normal body mass. Patients with an AF diagnosis had different risk factors for in-hospital death and 30-day rehospitalisation than their counterparts with diagnosis of cardiovascular diseases but without AF; however, the parameters of nutritional status played an important role in both patient groups. The obesity and cholesterol paradoxes were also observed.

  14. Comparative demography of an epiphytic lichen: support for general life history patterns and solutions to common problems in demographic parameter estimation.

    Science.gov (United States)

    Shriver, Robert K; Cutler, Kerry; Doak, Daniel F

    2012-09-01

    Lichens are major components in many terrestrial ecosystems, yet their population ecology is at best only poorly understood. Few studies have fully quantified the life history or demographic patterns of any lichen, with particularly little attention to epiphytic species. We conducted a 6-year demographic study of Vulpicida pinastri, an epiphytic foliose lichen, in south-central Alaska. After testing multiple size-structured functions to describe patterns in each V. pinastri demographic rate, we used the resulting estimates to construct a stochastic demographic model for the species. This model development led us to propose solutions to two general problems in construction of demographic models for many taxa: how to simply but accurately characterize highly skewed growth rates, and how to estimate recruitment rates that are exceptionally difficult to directly observe. Our results show that V. pinastri has rapid and variable growth and, for small individuals, low and variable survival, but that these traits are coupled with considerable longevity (e.g., >50 years mean future life span for a 4-cm(2) thallus) and little deviation of the stochastic population growth rate from the deterministic expectation. Comparisons of the demographic patterns we found with those of other lichen studies suggest that their relatively simple architecture may allow clearer generalities about growth patterns for lichens than for other taxa, and that the expected pattern of faster growth rates for epiphytic species is substantiated.

  15. Epidemiological characteristics of 6 species of muldrug-resistant organisms in general hospitals%综合医院6种多药耐药菌流行特征分析

    Institute of Scientific and Technical Information of China (English)

    黄娟; 胡绮萍; 黎燕宁; 郭世辉; 覃金爱; 黄小红; 张云; 韦巧灵; 张影华; 李兰兰

    2016-01-01

    目的:了解常见多药耐药菌(MDRO )在综合医院的流行特征,为临床提供预防控制依据。方法收集2014年1-12月107051例患者临床资料,分析MDRO感染率及科室分布,进行统计分析。结果2014年1-12月监测的6种MDRO及感染病例634例,感染率为0.59%,6种MDRO检出例数及其构成比分别为耐碳青霉烯类抗菌药物的鲍氏不动杆菌(CR‐AB)326例(51.42%)、耐碳青霉烯类抗菌药物的铜绿假单胞菌(CR‐PA )115例(18.14%)、M RSA 161例(25.39%)、耐碳青霉烯类抗菌药物的大肠埃希菌(CR‐E .coli)9例(1.42%)、耐碳青霉烯类抗菌药物的肺炎克雷伯菌(CR‐KP)7例(1.10%)、泛耐药肠杆菌科细菌(XDR‐ENT )16例(2.52%);CR‐AB、CR‐PA和MRSA在烧伤整形外科分布最多,其次是ICU和中医科病区;CR‐E .coli、CR‐KP和XDR‐ENT散在分布于少数科室;分离出的MDRO中,医院感染例数占总例数的49.68%,CR‐AB、XDR‐ENT、CR‐PA、CR‐E .coli、CR‐KP和 MRSA 医院感染病例的构成比分别为57.56%、56.25%、46.96%、44.44%、42.86%和36.65%。结论综合医院MDRO的感染率比较低;CR‐AB是最常见的MDRO ,其次是MRSA和CR‐PA ;烧伤整形外科病房、ICU和中医科病房是MDRO管理的重点科室;MDRO社区感染和医院感染的预防控制均应重视。%OBJECTIVE To understand the epidemiological characteristics of multidrug‐resistant organisms (MDROs) so as to provide guidance for clinical prevention and control .METHODS The clinical data were collected from 107 051 patients who were treated in hospitals from Jan 2014 to Dec 2014 .The incidence of MDROs infection and distribution of departments were statistically analyzed .RESULTS A total of 6 species of MDROs were moni‐tored from Jan 2014 to Dec 2014 ,and 634 patients had MDROs infections ,with the infection rate 0 .59

  16. Can cortical silent period and motor threshold be practical parameters in the comparison of patients with generalized epilepsy and patients with psychogenic non-epileptic seizures?.

    Science.gov (United States)

    İpekdal, İlker H; Karadaş, Ömer; Ulaş, Ümit H; Vural, Okay

    2013-01-01

    This study aimed to compare the cortical excitability of patients with generalized tonic-clonic seizures (GTCSs) and that of patients with psychogenic non-epileptic seizures (PNESs). Patients were classified into groups according to their electroencephalogram (EEG) findings and seizure types: group 1 = GTCS with an abnormal EEG, group 2 = GTCS with a normal EEG and group 3 = PNES with a normal EEG. The control group included healthy volunteers with normal EEGs. Cortical silent period (CSP) and motor threshold (MT) were measured for all groups and the results were compared. CSPs were significantly prolonged in groups 1 and 2 when compared with group 3 and the control group. No differences were found between the MT measurements of all groups. The prolongation of CSP may demonstrate the differences between the pathophysiological mechanisms of GTCS and those of PNES. Copyright © 2012 S. Karger AG, Basel.

  17. Michel parameters for τ decays τ→lνν̄ (l=e, μ) in a general two Higgs doublet model with μ−τ flavor violation

    Energy Technology Data Exchange (ETDEWEB)

    Tobe, Kazuhiro [Department of Physics, Nagoya University,Nagoya, 464-8602 (Japan); Kobayashi-Maskawa Institute for the Origin of Particles and the Universe,Nagoya University, Nagoya, 464-8602 (Japan)

    2016-10-21

    In a general two Higgs doublet model (2HDM), the anomaly of muon anomalous magnetic moment (muon g-2) can be explained by μ−τ flavor violating Yukawa couplings, motivated by the recent CMS excess in Higgs boson decay h→μτ. We study Michel parameters for τ decays τ→lνν̄ (l=e, μ) in the 2HDM with the lepton flavor violation, and show that they can be sensitive to the flavor structure as well as the Lorentz and chiral structures of the model. We find that the correction to the Michel parameter ξ{sub μ} in τ→μνν̄ is correlated to the contribution to the muon g-2, and it can be as large as 10{sup −4}−10{sup −2} in the parameter region where the μ−τ flavor violating Yukawa couplings explain the muon g-2 anomaly. Therefore the precision measurement of the Michel parameter at the level of 10{sup −4}−10{sup −2} would significantly probe the interesting parameter space for the solution to the muon g-2 anomaly.

  18. Epidemiology and the Tobacco Epidemic: How Research on Tobacco and Health Shaped Epidemiology.

    Science.gov (United States)

    Samet, Jonathan M

    2016-03-01

    In this article, I provide a perspective on the tobacco epidemic and epidemiology, describing the impact of the tobacco-caused disease epidemic on the field of epidemiology. Although there is an enormous body of epidemiologic evidence on the associations of smoking with health, little systematic attention has been given to how decades of research have affected epidemiology and its practice. I address the many advances that resulted from epidemiologic research on smoking and health, such as demonstration of the utility of observational designs and important parameters (the odds ratio and the population attributable risk), guidelines for causal inference, and systematic review approaches. I also cover unintended and adverse consequences for the field, including the strategy of doubt creation and the recruitment of epidemiologists by the tobacco industry to serve its mission. The paradigm of evidence-based action for addressing noncommunicable diseases began with the need to address the epidemic of tobacco-caused disease, an imperative for action documented by epidemiologic research.

  19. Epidemiology, molecular epidemiology, and risk factors for renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Chiara Paglino

    2011-12-01

    Full Text Available Despite only accounting for approximately 2% of all new primary cancer cases, renal cell carcinoma (RCC incidence has dramatically increased over time. Incidence rates vary greatly according to geographic areas, so that it is extremely likely that exogenous risk factors could play an important role in the development of this cancer. Several risk factors have been linked with RCC, including cigarette smoking, obesity, hypertension (and antihypertensive drugs, chronic kidney diseases (also dialysis and transplantation, as well as the use of certain analgesics. Furthermore, although RCC has not generally been considered an occupational cancer, several types of occupationally-derived exposures have been implicated in its pathogenesis. These include exposure to asbestos, chlorinated solvents, gasoline, diesel exhaust fumes, polycyclic aromatic hydrocarbons, printing inks and dyes, cadmium and lead. Finally, families with a predisposition to the development of renal neoplasms were identified and the genes involved discovered and characterized. Therefore, there are now four well-characterized, genetically determined syndromes associated with an increased incidence of kidney tumors, i.e., Von Hippel Lindau (VHL, Hereditary Papillary Renal Carcinoma (HPRC, Birt-Hogg-Dubé Syndrome (BHD, and Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC. This review will address present knowledge about the epidemiology, molecular epidemiology and risk factors of RCC.

  20. Understanding epidemiological transition in India

    Science.gov (United States)

    Yadav, Suryakant; Arokiasamy, Perianayagam

    2014-01-01

    Background Omran's theory explains changing disease patterns over time predominantly from infectious to chronic noncommunicable diseases (NCDs). India's epidemiological transition is characterized by dual burden of diseases. Kumar addressed low mortality and high morbidity in Kerala, which seems also to be true for India as a country in the current demographic scenario. Methods NSS data (1986–1987, 1995–1996, 2004) and aggregated data on causes of death provided by Registrar General India (RGI) were used to examine the structural changes in morbidity and causes of death. A zero-inflated poisson (ZIP) regression model and a beta-binomial model were used to corroborate the mounting age pattern of morbidity. Measures, namely the 25th and 75th percentiles of age-at-death and modal age-at-death, were used to examine the advances in mortality transition. Objective This study addressed the advances in epidemiological transition via exploring the structural changes in pattern of diseases and progress in mortality transition. Results The burden of NCDs has been increasing in old age without replacing the burden of communicable diseases. The manifold rise of chronic diseases in recent decades justifies the death toll and is responsible for transformation in the age pattern of morbidity. Over time, deaths have been concentrated near the modal age-at-death. Modal age-at-death increased linearly by 5 years for females (r2=0.9515) and males (r2=0.9020). Significant increase in modal age-at-death ascertained the dominance of old age mortality over the childhood/adult age mortality. Conclusions India experiences a dual burden of diseases associated with a remarkable transformation in the age pattern of morbidity and mortality, contemporaneous with structural changes in disease patterns. Continued progress in the pattern of diseases and mortality transition, accompanied by a linear rise in ex, unravels a compelling variation in advances found so far in epidemiological

  1. [Sperm DNA fragmentation: association with semen parameters in young men].

    Science.gov (United States)

    Osadchuk, L V; Tataru, D A; Kuznetsova, N N; Kleshev, M A; Markova, E V; Svetlakov, A V

    2016-12-01

    Abnormal sperm DNA integrity is an important risk factor for male infertility. The aim of this work was to examine sperm DNA fragmentation in a cohort of young male volunteers (n=111; age 21.0+/-0.2 years) from the general population and establish the association between the level of sperm DNA fragmentation and sperm functional parameters. Sperm DNA fragmentation index (DFI) was determined by SCSA (sperm chromatin structure assay) using flow cytometry. Standard semen parameters (concentration, motility, and morphology) were evaluated according to the WHO guidelines (2010). and conclusions. In the study cohort, 79.0%, 12.4% and 8.6% of men had normal (DFIfragmentation, respectively. Men with impaired spermatogenesis had greater IDF values (14.53+/-1.43%) than men with normal semen parameters (8.88+/-0.77%, pfragmentation using SCSA technique can be employed in epidemiological studies of male fertility.

  2. Epidemiological Study of Greek University Students' Mental Health

    Science.gov (United States)

    Kounenou, Kalliope; Koutra, Aikaterini; Katsiadrami, Aristea; Diacogiannis, Georgios

    2011-01-01

    In the present study, 805 Greek students participated by filling in self-report questionnaires studying depression (Center for Epidemiological Studies Depression Scale), general health status (General Health Questionnaire), general psychopathology (Symptom Checklist-90-R), and personal demographic features. Some of the more prevalent findings…

  3. [Kolsky register of births as an instrument of epidemiologic studies of female reproductive health].

    Science.gov (United States)

    Vaktstold, A; Talykova, L V; Chashchin, V P; Nieboer, E; Zotov, A M; Nikanov, A N; Romanova, N P; Udland, Iu Io

    2006-01-01

    The authors evaluate possible use of Monchegorsk retrospective birth database for demographic and epidemiologic studies of various female reproductive health parameters, newborn health parameters, as well as their connections with occupational and other environmental factors.

  4. en epidemiología

    Directory of Open Access Journals (Sweden)

    Ana V. Diez Roux

    2008-01-01

    Full Text Available La epidemiología sociocultural se caracteriza por la integración de procesos sociales, culturales, económicos y políticos con procesos biológicos en el estudio de los determinantes de la salud. Por definición, esto implica la consideración de determinantes especificados a múltiples niveles, desde los genes hasta las características de la sociedad en su totalidad. En este artículo se analizan diversos problemas metodológicos que surgen en epidemiología (y en las ciencias sociales en general por la presencia de múltiples niveles de organización que pueden ser relevantes para entender las causas de la salud y la enfermedad. Se subraya la necesidad de investigar conjuntamente (o de integrar determinantes de la salud definidos a distintos niveles. El artículo concluye con un examen de las implicaciones de la presencia de múltiples niveles para el estudio de los determinantes sociales o culturales de la salud.

  5. 平方误差损失函数下广义Pareto分布参数的Bayes估计%Bayes Estimation of Parameter of Generalized Pareto Distribution under Squared Error Loss Function

    Institute of Scientific and Technical Information of China (English)

    刘婉贞

    2013-01-01

    The paper aims to study the Bayes estimation of the parameter of the generalized Parato distribu-tion, basing on the parameter prior which is inverse Gamma prior distribution. Bayes estimators are obtained by us-ing the squared error loss function. The author also compares the MLE estimator with the Bayes estimator through Monte Carlo simulation.%本文在参数的先验分布为逆伽玛先验分布条件下研究广义Pareto分布参数的Bayes估计问题,并在平方误差损失函数下,导出了参数的Bayes估计。文末通过Monte Carlo数值模拟试验对极大似然估计和Bayes估计进行了比较。

  6. Ophthalmic epidemiology in Europe

    DEFF Research Database (Denmark)

    Delcourt, Cécile; Korobelnik, Jean-François; Buitendijk, Gabriëlle H S

    2016-01-01

    The European Eye Epidemiology (E3) consortium is a recently formed consortium of 29 groups from 12 European countries. It already comprises 21 population-based studies and 20 other studies (case-control, cases only, randomized trials), providing ophthalmological data on approximately 170,000 Euro...

  7. Inflammatory bowel disease epidemiology

    DEFF Research Database (Denmark)

    Burisch, Johan; Munkholm, Pia

    2013-01-01

    The occurrence of inflammatory bowel disease (IBD) is increasing worldwide, yet the reasons remain unknown. New therapeutic approaches have been introduced in medical IBD therapy, but their impact on the natural history of IBD remains uncertain. This review will summarize the recent findings in t...... in the epidemiology of IBD....

  8. [Toxoplasmosis: Epidemiology, Diagnosis, Treatment].

    Science.gov (United States)

    Khryanin, A A; Reshetnikov, O V; Kuvshinova, I N

    2015-01-01

    The up-to-date literature and original data on the epidemiology, diagnosis and treatment of toxoplasmosis are presented. Particular attention is paid to the parasite infection during pregnancy. Spiramycin is the drug of choice for acute toxoplasmosis in pregnant women.

  9. Molecular epidemiology of ascariasis

    DEFF Research Database (Denmark)

    Betson, Martha; Halstead, Fennella; Nejsum, Peter

      We are using molecular epidemiology techniques to study the population structure of Ascaris obtained from humans and pigs. Worms were obtained from human hosts on Zanzibar and in Uganda, Bangladesh, Guatemala and Nepal and Ascaris from pigs were collected from in Uganda, Tanzania, Denmark...

  10. Epidemiology of Down Syndrome

    Science.gov (United States)

    Sherman, Stephanie L.; Allen, Emily G.; Bean, Lora H.; Freeman, Sallie B.

    2007-01-01

    Down syndrome (DS) is the most commonly identified genetic form of mental retardation and the leading cause of specific birth defects and medical conditions. Traditional epidemiological studies to determine the prevalence, cause, and clinical significance of the syndrome have been conducted over the last 100 years. DS has been estimated to occur…

  11. Triangulation in aetiological epidemiology.

    Science.gov (United States)

    Lawlor, Debbie A; Tilling, Kate; Davey Smith, George

    2016-12-01

    Triangulation is the practice of obtaining more reliable answers to research questions through integrating results from several different approaches, where each approach has different key sources of potential bias that are unrelated to each other. With respect to causal questions in aetiological epidemiology, if the results of different approaches all point to the same conclusion, this strengthens confidence in the finding. This is particularly the case when the key sources of bias of some of the approaches would predict that findings would point in opposite directions if they were due to such biases. Where there are inconsistencies, understanding the key sources of bias of each approach can help to identify what further research is required to address the causal question. The aim of this paper is to illustrate how triangulation might be used to improve causal inference in aetiological epidemiology. We propose a minimum set of criteria for use in triangulation in aetiological epidemiology, summarize the key sources of bias of several approaches and describe how these might be integrated within a triangulation framework. We emphasize the importance of being explicit about the expected direction of bias within each approach, whenever this is possible, and seeking to identify approaches that would be expected to bias the true causal effect in different directions. We also note the importance, when comparing results, of taking account of differences in the duration and timing of exposures. We provide three examples to illustrate these points. © The Author 2017. Published by Oxford University Press on behalf of the International Epidemiological Association.

  12. The Epidemiology of Pheochromocytoma

    DEFF Research Database (Denmark)

    Ladefoged Ebbehøj, Andreas

    2017-01-01

    Pheochromocytoma and catecholamine secreting paraganglioma (PPGL) are exceedingly rare endocrine tumours, but remain a frequent diagnostic dilemma due to their potential life-threatening nature. Reliable data on the epidemiology of PPGL is lacking and no time trends in incidence rates (IR) have...

  13. Epidemiology of burns

    NARCIS (Netherlands)

    Dokter, Jan

    2016-01-01

    The aim of this thesis is to understand the epidemiology, treatment and outcomes of specialized burn care in The Netherlands. This thesis is mainly based on historical data of the burn centre in Rotterdam from 1986, combined with historical data from the burn centres in Groningen and Beverwijk from

  14. Epidemiology and treatment of mucormycosis.

    Science.gov (United States)

    Lewis, Russell E; Kontoyiannis, Dimitrios P

    2013-09-01

    Mucormycosis is an uncommon but aggressive opportunistic fungal infection that afflicts patients with severe underlying immunosuppression, uncontrolled hyperglycemia and/or ketoacidosis, patients with iron overload resulting from frequent blood transfusions or blood disorders and occasionally healthy patients who are inoculated with fungal spores through traumatic injuries. The clinical presentation of mucormycosis is initially indistinguishable from other common infections, and if not diagnosed early and aggressively treated, it is almost always fatal. In this article we summarize recent changes in the epidemiology of mucormycosis, discuss diagnostic and clinical clues suggestive of the infection and provide a general strategy for managing the infection in the absence of data from well-controlled, prospective clinical trials.

  15. Fibromyalgia: Prevalence, epidemiologic profiles and economic costs.

    Science.gov (United States)

    Cabo-Meseguer, Asensi; Cerdá-Olmedo, Germán; Trillo-Mata, José Luis

    2017-07-19

    Fibromyalgia is an idiopathic chronic condition that causes widespread musculoskeletal pain, hyperalgesia and allodynia. This review aims to approach the general epidemiology of fibromyalgia according to the most recent published studies, identifying the general worldwide prevalence of the disease, its basic epidemiological profiles and its economic costs, with specific interest in the Spanish and Comunidad Valenciana cases. Fibromyalgia affects, on average, 2.10% of the world's population; 2.31% of the European population; 2.40% of the Spanish population; and 3.69% of the population in the Comunidad Valenciana. It supposes a painful loss of the quality of life of the people who suffer it and the economic costs are enormous: in Spain is has been estimated at more than 12,993 million euros annually. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  16. Epidemiological models for the spread of anti-malarial resistance

    Directory of Open Access Journals (Sweden)

    Antia R

    2003-02-01

    Full Text Available Abstract Background The spread of drug resistance is making malaria control increasingly difficult. Mathematical models for the transmission dynamics of drug sensitive and resistant strains can be a useful tool to help to understand the factors that influence the spread of drug resistance, and they can therefore help in the design of rational strategies for the control of drug resistance. Methods We present an epidemiological framework to investigate the spread of anti-malarial resistance. Several mathematical models, based on the familiar Macdonald-Ross model of malaria transmission, enable us to examine the processes and parameters that are critical in determining the spread of resistance. Results In our simplest model, resistance does not spread if the fraction of infected individuals treated is less than a threshold value; if drug treatment exceeds this threshold, resistance will eventually become fixed in the population. The threshold value is determined only by the rates of infection and the infectious periods of resistant and sensitive parasites in untreated and treated hosts, whereas the intensity of transmission has no influence on the threshold value. In more complex models, where hosts can be infected by multiple parasite strains or where treatment varies spatially, resistance is generally not fixed, but rather some level of sensitivity is often maintained in the population. Conclusions The models developed in this paper are a first step in understanding the epidemiology of anti-malarial resistance and evaluating strategies to reduce the spread of resistance. However, specific recommendations for the management of resistance need to wait until we have more data on the critical parameters underlying the spread of resistance: drug use, spatial variability of treatment and parasite migration among areas, and perhaps most importantly, cost of resistance.

  17. Molecular Epidemiology of Foodborne Pathogens

    Science.gov (United States)

    Chen, Yi; Brown, Eric; Knabel, Stephen J.

    The purpose of this chapter is to describe the basic principles and advancements in the molecular epidemiology of foodborne pathogens. Epidemiology is the study of the distribution and determinants of infectious diseases and/or the dynamics of disease transmission. The goals of epidemiology include the identification of physical sources, routes of transmission of infectious agents, and distribution and relationships of different subgroups. Molecular epidemiology is the study of epidemiology at the molecular level. It has been defined as "a science that focuses on the contribution of potential genetic and environmental risk factors, identified at the molecular level, to the etiology, distribution and prevention of diseases within families and across populations".

  18. 基于改进粒子群优化的广义K分布杂波模型参数估计方法%Parameter estimation for generalized K-distribution clutter model based on improved particle swarm optimization

    Institute of Scientific and Technical Information of China (English)

    刘峥; 张翼; 何峻; 付强

    2011-01-01

    In the modeling, simulation and classification of the clutter, the estimation of model parameters of the clutter is an important research area. For the frequently adopted generalized K-distribution clutter model,the speckle and amplitude modulation components are both assumed to obey the generalized Gamma distribution. It turns out that the parameter estimation in this model is difficult due to high-dimensionality and nonlinearity. In order to solve this problem, this paper applies the improved particle swarm optimization (PSO) to the estimation of parameters of the generalized K-distribution. Specifically, the paper adopts the uniform design method to initialize the particle swarm and employs the strategy of across and mutation to improve the global convergence performance of the standard PSO. In fact, the proposed method can accurately estimate each parameter of the clutter model. Moreover, the method has the advantages of low computation burden, fast convergence rate and preferable stability. It is demonstrated by simulation results that the method is of good adaptability and estimation accuracy, which proves its effectiveness and exactness.%在杂波建模、仿真和分类识别研究中,杂波模型参数估计是一个重要的内容.广义K分布杂波模型的散斑分量和幅度调制分量均服从广义Gamma分布,参数估计存在高维、非线性等问题.将改进的粒子群优化算法应用于广义K分布杂波模型参数估计,采用均匀设计方法初始化粒子群,利用交叉变异策略改善粒子群优化的全局收敛性,该方法能准确地估计杂波模型各参数,计算简单,收敛速度较快,稳定性较好.仿真实验结果表明该方法具有良好的适应性和估计精度,验证了其有效性和准确性.

  19. The epidemiology of anxiety disorders: a review

    OpenAIRE

    Martin, Patrick

    2003-01-01

    Epidemiological studies show that anxiety disorders are highly prevalent and an important cause of functional impairment; they constitute the most frequent menial disorders in the community. Phobias are the most common with the highest rates for simple phobia and agoraphobia. Panic disorder (PD) and obsessive-compulsive disorder (OCD) are less frequent (2% lifetime prevalence), and there are discordant results for social phobia (SP) (2%-16%) and generalized anxiety disorder (GAD) (3%-30%). Th...

  20. The effects of ionic strength and organic matter on virus inactivation at low temperatures: general likelihood uncertainty estimation (GLUE) as an alternative to least-squares parameter optimization for the fitting of virus inactivation models

    Science.gov (United States)

    Mayotte, Jean-Marc; Grabs, Thomas; Sutliff-Johansson, Stacy; Bishop, Kevin

    2017-06-01

    This study examined how the inactivation of bacteriophage MS2 in water was affected by ionic strength (IS) and dissolved organic carbon (DOC) using static batch inactivation experiments at 4 °C conducted over a period of 2 months. Experimental conditions were characteristic of an operational managed aquifer recharge (MAR) scheme in Uppsala, Sweden. Experimental data were fit with constant and time-dependent inactivation models using two methods: (1) traditional linear and nonlinear least-squares techniques; and (2) a Monte-Carlo based parameter estimation technique called generalized likelihood uncertainty estimation (GLUE). The least-squares and GLUE methodologies gave very similar estimates of the model parameters and their uncertainty. This demonstrates that GLUE can be used as a viable alternative to traditional least-squares parameter estimation techniques for fitting of virus inactivation models. Results showed a slight increase in constant inactivation rates following an increase in the DOC concentrations, suggesting that the presence of organic carbon enhanced the inactivation of MS2. The experiment with a high IS and a low DOC was the only experiment which showed that MS2 inactivation may have been time-dependent. However, results from the GLUE methodology indicated that models of constant inactivation were able to describe all of the experiments. This suggested that inactivation time-series longer than 2 months were needed in order to provide concrete conclusions regarding the time-dependency of MS2 inactivation at 4 °C under these experimental conditions.

  1. Epidemiological studies on syncope

    DEFF Research Database (Denmark)

    Ruwald, Martin Huth

    2013-01-01

    of the patients play an essential role. In epidemiology these factors have major impact on the outcome of the patients. Until recently, even the definition of syncope differed from one study to another which has made literature reviews difficult. Traditionally the data on epidemiology of syncope has been taken...... from smaller studies from different clinical settings with wide differences in patient morbidity. Through the extensive Danish registries we examined the characteristics and prognosis of the patients hospitalized due to syncope in a nationwide study. The aims of the present thesis were to investigate......, prevalence and cardiovascular factors associated with the risk of syncope, 4) the prognosis in healthy individuals discharged after syncope, and 5) the prognosis of patients after syncope and evaluation of the CHADS2 score as a tool for short- and long-term risk prediction. The first studies of the present...

  2. Epidemiology of colorectal cancer

    Science.gov (United States)

    Marley, Andrew R; Nan, Hongmei

    2016-01-01

    Colorectal cancer is currently the third deadliest cancer in the United States and will claim an estimated 49,190 U.S. lives in 2016. The purpose of this review is to summarize our current understanding of this disease, based on nationally published statistics and information presented in peer-reviewed journal articles. Specifically, this review will cover the following topics: descriptive epidemiology (including time and disease trends both in the United States and abroad), risk factors (environmental, genetic, and gene-environment interactions), screening, prevention and control, and treatment. Landmark discoveries in colorectal cancer risk factor research will also be presented. Based on the information reviewed for this report, we suggest that future U.S. public health efforts aim to increase colorectal cancer screening among African American communities, and that future worldwide colorectal cancer epidemiology studies should focus on researching nutrient-gene interactions towards the goal of improving personalized treatment and prevention strategies.

  3. Landmarks in the history of cancer epidemiology.

    Science.gov (United States)

    Greenwald, Peter; Dunn, Barbara K

    2009-03-15

    The application of epidemiology to cancer prevention is relatively new, although observations of the potential causes of cancer have been reported for more than 2,000 years. Cancer was generally considered incurable until the late 19th century. Only with a refined understanding of the nature of cancer and strategies for cancer treatment could a systematic approach to cancer prevention emerge. The 20th century saw the elucidation of clues to cancer causation from observed associations with population exposures to tobacco, diet, environmental chemicals, and other exogenous factors. With repeated confirmation of such associations, researchers entertained for the first time the possibility that cancer, like many of the infectious diseases of the time, might be prevented. By the mid-20th century, with antibiotics successfully addressing the majority of infectious diseases and high blood pressure treatment beginning to affect the prevalence of heart disease in a favorable direction, the focus of much of epidemiology shifted to cancer. The early emphasis was on exploring, in greater depth, the environmental, dietary, hormonal, and other exogenous exposures for their potential associations with increased cancer risk. The first major breakthrough in identifying a modifiable cancer risk factor was the documentation of an association between tobacco smoking and lung cancer. During the past four decades, epidemiologic studies have generated population data identifying risk factors for cancers at almost every body site, with many cancers having multiple risk factors. The development of technologies to identify biological molecules has facilitated the incorporation of these molecular manifestations of biological variation into epidemiologic studies, as markers of exposure as well as putative surrogate markers of cancer outcome. This technological trend has, during the past two decades, culminated in emphasis on the identification of genetic variants and their products as

  4. The Epidemiology of Sarcoma

    OpenAIRE

    Burningham Zachary; Hashibe Mia; Spector Logan; Schiffman Joshua D

    2012-01-01

    Abstract Sarcomas account for over 20% of all pediatric solid malignant cancers and less than 1% of all adult solid malignant cancers. The vast majority of diagnosed sarcomas will be soft tissue sarcomas, while malignant bone tumors make up just over 10% of sarcomas. The risks for sarcoma are not well-understood. We evaluated the existing literature on the epidemiology and etiology of sarcoma. Risks for sarcoma development can be divided into environmental exposures, genetic susceptibility, a...

  5. Epigenetic epidemiology of cancer.

    Science.gov (United States)

    Barrow, Timothy M; Michels, Karin B

    2014-12-05

    Epigenetic epidemiology includes the study of variation in epigenetic traits and the risk of disease in populations. Its application to the field of cancer has provided insight into how lifestyle and environmental factors influence the epigenome and how epigenetic events may be involved in carcinogenesis. Furthermore, it has the potential to bring benefit to patients through the identification of diagnostic markers that enable the early detection of disease and prognostic markers that can inform upon appropriate treatment strategies. However, there are a number of challenges associated with the conduct of such studies, and with the identification of biomarkers that can be applied to the clinical setting. In this review, we delineate the challenges faced in the design of epigenetic epidemiology studies in cancer, including the suitability of blood as a surrogate tissue and the capture of genome-wide DNA methylation. We describe how epigenetic epidemiology has brought insight into risk factors associated with lung, breast, colorectal and bladder cancer and review relevant research. We discuss recent findings on the identification of epigenetic diagnostic and prognostic biomarkers for these cancers.

  6. Assessing performance of feedlot operations using epidemiology.

    Science.gov (United States)

    Corbin, Marilyn J; Griffin, Dee

    2006-03-01

    The progressive feedlot veterinarian must be well versed not only in individual production animal medicine, but also in population-based medicine. Feedlot health programs must be goal oriented, and evaluation of these goals is accomplished through diligent use of record systems and analytic evaluation of these record systems. Basic feedlot monitoring parameters include health and economic parameters in addition to the use of bench marking parameters between and among feed yards. When these parameters have significant changes, steps should be initiated to begin field investigations. Feedlot epidemiology uses several novel applications such as partial budgeting, risk assessment, and packing plant audits to provide scientifically sound and economically feasible solutions for the feeding industry.

  7. Epidemiology of adult asthma in Asia: toward a better understanding

    OpenAIRE

    Song, Woo-Jung; Kang, Min-Gyu; Chang, Yoon-Seok; Cho, Sang-Heon

    2014-01-01

    Asia is the world's most dynamic area. Asthma is a major chronic disease in Asia, like other continents. However, unlike childhood asthma, the epidemiological burden of asthma in Asian adults has been unclear. Here we reviewed the currently available literatures on the epidemiology of adult asthma in the Asian community populations. Adult asthma prevalence was generally lower in Asian than in Europe, but the increasing trends suggested the disease burden to rise in the near future. However, f...

  8. Parameter Estimation

    DEFF Research Database (Denmark)

    2011-01-01

    of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to generate a set......In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  9. The North Staffordshire Osteoarthritis Project – NorStOP: Prospective, 3-year study of the epidemiology and management of clinical osteoarthritis in a general population of older adults

    Directory of Open Access Journals (Sweden)

    Dziedzic Krysia

    2004-01-01

    Full Text Available Abstract Background The clinical syndrome of joint pain and stiffness in older people is the commonest cause of disability and health care consultation in this age group. Yet there have been few prospective studies of its course over time and its impact on personal and social life. We plan a cohort study in the general population aged 50 years and over to determine the course and prognosis of hand, hip, knee and foot pain, and the impact of these syndromes on participation levels and health care use. Methods All patients aged 50 years and over registered with 3 local general practices are to be recruited to a population-based cohort study through the use of a two-stage mailing process. Participants will initially complete a "Health Survey" questionnaire. This will collect information on several areas of life including socio-demographics, general health, physical function, participation, and bodily pain. Those who state that they have experienced any hand problem or any pain in their hands, hips, knees, or feet in the previous 12 months, and also give permission to be re-contacted, will be mailed a "Regional Pains Survey" questionnaire which collects detailed information on the four selected body regions (hand, hips, knees, feet. Follow-up data for the three-year period subsequent to cohort recruitment will be collected through two sources: i general practice medical records and ii repeat mailed survey.

  10. Epidemiology of neurocysticercosis in Brazil.

    Science.gov (United States)

    Agapejev, S

    1996-01-01

    A revision of literature was done with the objective of tracing an epidemiologic profile of neurocysticercosis (NCC) in Brazil. The prevalence was 0.12-9% in autopsies. The frequency was 0.03-7.5% in clinical series and 0.68-5.2% in seroepidemiological studies. The disease corresponds to 0.08-2.5% of admissions to general hospitals. Patient origin was rural in 30-63% of cases. The most involved age range (64-100%) was 11 to 60 years, with a predominance (22-67%) between 21 and 40 years. The male sex was the most affected (51-80%). In the severe forms there was a predominance of urban origin (53-62%) and of the female sex (53-75%). The period of hospitalization ranges from 1 to 254 days and 33 to 50% of patients suffer 1.7 +/- 1.4 admissions. The clinical picture was variable, with a predominance of epileptic syndrome (22-92%) and intracranial hypertension (19-89%). Psychiatric manifestations were associated in 9-23% of patients. Lethality was 0.29% in terms of all diseases in general and 4.8-25.9% in terms of neurologic diseases. The asymptomatic form was detected in 6% of patients in clinical series and in 48.5% of case from autopsies. The racemose form and ventricular localization also was observed as asymptomatic form. Among the patients with cutaneous cysticercosis 65% of them showed neurologic manifestations.

  11. Epidemiological Approaches to Metal Toxicology

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Budtz-Jørgensen, Esben

    2014-01-01

    to their propensity to cause chronic or delayed toxicity, epidemiological studies of metal toxicity have focused on a wide variety of organ systems, subtle effects as well as mortality, and differences in susceptibility. Toxic metals often serve as paradigms of environmental and occupational toxicity....... For these reasons, this chapter highlights the fields within epidemiology that are most relevant to toxic metals and discusses where these substances serve to illustrate important epidemiological concepts. Chapter sections include subjects such as epidemiological terms, study design, study population, exposure......Epidemiological methods are crucial to extract as much valid information as possible from human metal exposures. Thus, modern epidemiological approaches have elucidated human health effects that were not apparent in the past. At the same time, metal toxicology has served as a useful arena...

  12. Trichinosis: Epidemiology in Thailand

    Institute of Scientific and Technical Information of China (English)

    Natthawut Kaewpitoon; Soraya Jatesadapattaya Kaewpitoon; Chutikan Philasri; Ratana Leksomboon; Chanvit Maneenin; Samaporn Sirilaph; Prasit Pengsaa

    2006-01-01

    Trichinosis is one of the most common food-borne parasitic zoonoses in Thailand and many outbreaks are reported each year. This paper reviews the history, species,and epidemiology of the disease and food habits of the people with an emphasis on the north, northeast, central and south regions of Thailand. The earliest record of trichinosis in Thailand was in 1962 in the Mae Sariang District, Mae Hong Son Province. Since then, about 130 outbreaks have been reported involving 7392 patients and 97 deaths (1962-2005). The highest number of cases, 557, was recorded in 1983. The annual epidemiological surveillance reports of the Bureau of Epidemiology,Department of Disease Control, Ministry of Public Health,Thailand, show that trichinosis cases increased from 61 in 1997 to 351 in 1998.In contrast to these figures, the number of reported cases decreased to 16 in 1999 and 128 cases in 2000. There was no record of trichinosis in 2001, but then the figures for 2002, 2003 and 2004 were 289, 126 and 212 respectively. The infected patients were mostly in the 35-44 years age group and the disease occurred more frequently in men than women at a ratio of 1.7-2.0:1. There were 84 reported cases of trichinosis in Chiang Rai, Nan, Chiang Mai, Si Sa ket,Nakhon Phanom, Kalasin, Nakhon Ratchasima, Nakhon Nayok, Nakhon Pathom and Surat Thani, provinces located in different parts of Thailand in 2005. The outbreaks were more common in the northern areas, especially in rural areas where people ate raw or under-cooked pork and/or wild animals. This indicates the need for health education programs to prevent and control trichinosis as soon as possible in the high-risk areas.

  13. 自适应控制参数的通用差异演化算法研究%Research on generalized differential evolution algorithm based on adaptive controlling parameter

    Institute of Scientific and Technical Information of China (English)

    简平; 邹鹏; 熊伟; 陈治科

    2012-01-01

    为提高求解多目标优化问题效率,对通用差异演化(GDE)算法及其自适应参数控制问题进行了研究.首先,分析了GDE3算法的编码、交叉、变异、选择等原理和算法流程;然后,利用个体的适应度作为参数调整的依据,并结合一定的调整概率提出一种新的对缩放因子和交叉概率参数自适应控制策略,提高算法的搜索能力;最后,通过典型的多目标函数对自适应控制参数的通用演化算法( selfGDE3)、GDE3和非劣分层遗传算法2(NSGA-Ⅱ)的性能进行比较分析,结果表明,selfGDE3算法具有良好的搜索性能.%In order to solve the multi-objective optimization problem efficiently, this paer researched on generalized differential evolution algorithm and the method of adaptive controlling parameter. Firstly, it analyzed the principle and process of generalized differential evolution algorithm 3,including coding,crossover,mutation. Secondly, the algorithm put forward adaptive controlling strategy to crossover and mutation parameter based on the fitness of individual and the adjusting probability, which improved the performance of algorithm. Finally, it compared the performance of selfGDE3 , GDE3 and NSGA- II through testing some benchmark functions. The results show the feasibility of selfGDE3.

  14. Epidemiology of tuberculosis immunology.

    Science.gov (United States)

    Fox, G J; Menzies, D

    2013-01-01

    Immunological impairment plays a major role in the epidemiology of TB. Globally, the most common causes of immunological impairment are malnutrition, diabetes, HIV/AIDS, aging, and smoking. With the notable exception of HIV, each factor leads to relatively mild immunological impairment in individuals. However, as these conditions affect a significant proportion of the population, they contribute substantially to the incidence of TB at a global scale. Understanding immunological impairment is central to understanding the global TB pandemic, and vital to the development of effective disease control strategies.

  15. Epidemiology of Brain Tumors.

    Science.gov (United States)

    McNeill, Katharine A

    2016-11-01

    Brain tumors are the commonest solid tumor in children, leading to significant cancer-related mortality. Several hereditary syndromes associated with brain tumors are nonfamilial. Ionizing radiation is a well-recognized risk factor for brain tumors. Several industrial exposures have been evaluated for a causal association with brain tumor formation but the results are inconclusive. A casual association between the common mutagens of tobacco, alcohol, or dietary factors has not yet been established. There is no clear evidence that the incidence of brain tumors has changed over time. This article presents the descriptive epidemiology of the commonest brain tumors of children and adults.

  16. Epidemiologia social Social epidemiology

    Directory of Open Access Journals (Sweden)

    Rita Barradas Barata

    2005-03-01

    Full Text Available Este artigo trata da emergência da epidemiologia social concomitantemente ao surgimento da epidemiologia como disciplina científica, destacando as condições teóricas e epistemológicas desse aparecimento. Em seguida são enfocadas as razões para o declínio dessa abordagem, assim como para seu ressurgimento na década de 60, no século XX. São apresentadas as diferentes correntes teóricas atualmente vigentes na epidemiologia social, destacando as características gerais e as limitações de cada uma delas. Especial atenção é dada às seguintes formulações: a eco-epidemiologia proposta por Mervin Susser, a teoria do capital social, a perspectiva do curso de vida, a teoria da produção social da doença e a teoria ecosocial elaborada por Nancy Krieger. O panorama traçado pretende demonstrar a vitalidade dessa abordagem, bem como indicar a diversidade de aspectos em seu interior. Para finalizar são apontados alguns dilemas e desafios.This paper reviews the latest trends in social epidemiology. It analyzes the emergence of epidemiology as a scientific discipline in the nineteenth century focusing on the main characteristics of the episteme of the period. This paper also analyzes the decline of the social approach in the beginning of the twentieth century and the resurgence of social interest in the sixties. The multiple approaches of social epidemiology currently adopted are commented. The study also emphasizes Susser's proposal of ecoepidemiology, describing its characteristics and pointing out limitations. Next, there is a discussion of the social capital theory and its potentialities for epidemiological studies. The life course perspective is also analyzed, mentioning its psychological and material versions. Latin America's social production of the health and disease process is presented along with an overview of Nancy Krieger's social ecoepidemiology. Finally, some dilemmas and challenges for the future are presented.

  17. Analysis of peripheral blood parameter in children patients with acute generalized pustular psoriasis%儿童急性泛发性脓疱型银屑病外周血参数分析

    Institute of Scientific and Technical Information of China (English)

    王艺蓉; 程茹虹; 李明; 姚志荣

    2015-01-01

    Objective:To determine the changes of the levels of peripheral blood platelet parameters, Cre-active protein (CRP) and eosnophils (EOS) in children with acute generalized pustular psoriasis (AGPP). Methods:The levels of peripheral blood platelet parameters, CRP and EOS in 41 children with AGPP, 37 healthy children and 31 children with psoriasis vulgaris were detected. Results: The levels of PLT count, platelet hematocrit ( PCT) and CRP in the active stage of AGPP group were higher than those in the other two groups ( P0.05). The levels of PLT count, PCT and CRP in the recovery stage of AGPP were lower than those in active stage. Conclusion:Platelet parameters and CRP level could be as assistant indicators in monitoring the progression of children with AGPP.%目的::明确儿童急性泛发型脓疱性银屑病(AGPP)血小板参数、C反应蛋白(CRP)及嗜酸粒细胞水平变化。方法:检测41例儿童AGPP患者、37例健康儿童对照及31例儿童寻常型银屑病患者( PV)血小板参数、CRP及嗜酸粒细胞水平。结果: AGPP进展期PLT计数、血小板压积( PCT), CRP均显著高于儿童PV患者及儿童正常对照组( P0.05)。消退期AGPP患者PLT计数、PCT及CRP显著低于进展期AGPP患者( P<0.05)。结论:血小板参数及CRP水平可作为AGPP病程进展及治疗评价的参考指标。

  18. Epidemiology in Ethiopia 200 years after John Snow's birth.

    Science.gov (United States)

    Enquselassie, Fikre

    2013-10-01

    The year 2013 marks exactly 200 years since John Snow, known as the father of modern epidemiology, was born. In 19th century, epidemiologists like John Snow, concentrated almost entirely upon infectious diseases of humans measuring the burden of disease, describing pattern and attempting to understand the transmission dynamics. During the second half of the 20th century; big changes occurred so that epidemiologists in the developed world started to use systematized approaches to investigate the etiologies, conditions and to evaluate interventions through different study designs. However, the situation in the developing world is not the same as the rest of the world. Even 200 years after Snow's birth, epidemiological capacity is lowest in Africa. This article attempts to describe that Ethiopia is not exceptional. In the past few decades, there have been some attempts to build capacity in the country by launching training programs in clinical epidemiology, general epidemiology and field epidemiology. However, not only few epidemiologists are trained, but, limited funding, high-teaching burdens, poor working conditions and low salaries are among important contributors for epidemiological brain drain in Ethiopia. Thus, strengthening learning opportunities and rewarding career paths are required to increase human resource capacity and retain skilled personnel in the field of epidemiology.

  19. Transforming Epidemiology for 21st Century Medicine and Public Health

    Energy Technology Data Exchange (ETDEWEB)

    Khoury, Muin J [National Institutes of Health; Lam, Tram Kim [National Institutes of Health; Ioannidis, John [Stanford University; Hartge, Patricia [National Institutes of Health; Spitz, Margaret R. [Baylor College of Medicine, Huston; Buring, Julie E. [Brigham and Women' s Hospital; Chanock, Stephen J. [National Institutes of Health; Tourassi, Georgia [ORNL; Zauber, Ann [Memorial Sloan-Kettering Cancer Center; Schully, Sheri D [National Institutes of Health

    2013-01-01

    n 2012, the National Cancer Institute (NCI) engaged the scientific community to provide a vision for cancer epidemiology in the 21st century. Eight overarching thematic recommendations, with proposed corresponding actions for consideration by funding agencies, professional societies, and the research community emerged from the collective intellectual discourse. The themes are (i) extending the reach of epidemiology beyond discovery and etiologic research to include multilevel analysis, intervention evaluation, implementation, and outcomes research; (ii) transforming the practice of epidemiology by moving toward more access and sharing of protocols, data, metadata, and specimens to foster collaboration, to ensure reproducibility and replication, and accelerate translation; (iii) expanding cohort studies to collect exposure, clinical, and other information across the life course and examining multiple health-related endpoints; (iv) developing and validating reliable methods and technologies to quantify exposures and outcomes on a massive scale, and to assess concomitantly the role of multiple factors in complex diseases; (v) integrating big data science into the practice of epidemiology; (vi) expanding knowledge integration to drive research, policy, and practice; (vii) transforming training of 21st century epidemiologists to address interdisciplinary and translational research; and (viii) optimizing the use of resources and infrastructure for epidemiologic studies. These recommendations can transform cancer epidemiology and the field of epidemiology, in general, by enhancing transparency, interdisciplinary collaboration, and strategic applications of new technologies. They should lay a strong scientific foundation for accelerated translation of scientific discoveries into individual and population health benefits.

  20. Articulatory Parameters.

    Science.gov (United States)

    Ladefoged, Peter

    1980-01-01

    Summarizes the 16 parameters hypothesized to be necessary and sufficient for linguistic phonetic specifications. Suggests seven parameters affecting tongue shapes, three determining the positions of the lips, one controlling the position of the velum, four varying laryngeal actions, and one controlling respiratory activity. (RL)

  1. Parameter Estimation

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian;

    2011-01-01

    of optimisation techniques coupled with dynamic solution of the underlying model. Linear and nonlinear approaches to parameter estimation are investigated. There is also the application of maximum likelihood principles in the estimation of parameters, as well as the use of orthogonal collocation to generate a set...

  2. Epidemiology of Dissociative Disorders: An Overview

    Directory of Open Access Journals (Sweden)

    Vedat Sar

    2011-01-01

    Full Text Available General psychiatric assessment instruments do not cover DSM-IV dissociative disorders. Many large-scale epidemiological studies led to biased results due to this deficit in their methodology. Nevertheless, screening studies using diagnostic tools designed to assess dissociative disorders yielded lifetime prevalence rates around 10% in clinical populations and in the community. Special populations such as psychiatric emergency ward applicants, drug addicts, and women in prostitution demonstrated the highest rates. Data derived from epidemiological studies also support clinical findings about the relationship between childhood adverse experiences and dissociative disorders. Thus, dissociative disorders constitute a hidden and neglected public health problem. Better and early recognition of dissociative disorders would increase awareness about childhood traumata in the community and support prevention of them alongside their clinical consequences.

  3. Epidemiological studies of cancer in aircrew.

    Science.gov (United States)

    Hammer, Gaël P; Blettner, Maria; Zeeb, Hajo

    2009-10-01

    Exposure to cosmic ionising radiation, in addition to other specific occupational risks, is of concern to aircrew members. Epidemiological studies provide an objective way to assess the health of this occupational group. We systematically reviewed the epidemiological literature on health of aircrew members since 1990, focusing on cancer as the endpoint of interest. Sixty-five relevant publications were identified and reviewed. Whereas overall cancer incidence and mortality was generally lower than in the comparison population, consistently elevated risks were reported for breast cancer incidence in female aircrew members and for melanoma in both male and female aircrew members. Brain cancer was increased in some studies among pilots. Occasionally trends of increasing cancer mortality or incidence with increasing estimated radiation dose were reported. Ionising radiation is considered to contribute little if at all to the elevated risks for cancers among aircrew, whereas excess ultraviolet radiation is a probable cause of the increased melanoma risk.

  4. [Epidemiological significance of the metabolic syndrome].

    Science.gov (United States)

    Horáková, D; Azeem, K; Dumbrovská, L; Vlčková, J; Horák, V; Kollárová, H

    From an epidemiological point of view, the metabolic syndrome is a group of risk factors causally, rather than coincidentally, related to insulin resistance. The metabolic syndrome is a condition with relatively high prevalence rates in both the Czech Republic and in other developed countries. There is a clear trend of increasing prevalence in both sexes depending on age. In the Czech Republic, the syndrome is less common in females (25.5%) than in males (37.6%). Epidemiological studies found white (Europoid race) males to be at higher risk due to abdominal obesity. The definition of the metabolic syndrome has evolved over time and helps to identify individuals at high risk of developing cardiovascular disease and type 2 diabetes, hence the use of the term cardiometabolic syndrome. Early detection of metabolic syndrome symptoms including insulin resistance should be performed mainly by general practitioners as part of regular check-ups.

  5. Global epidemiology of sporotrichosis.

    Science.gov (United States)

    Chakrabarti, Arunaloke; Bonifaz, Alexandro; Gutierrez-Galhardo, Maria Clara; Mochizuki, Takashi; Li, Shanshan

    2015-01-01

    Sporotrichosis is an endemic mycosis caused by the dimorphic fungus Sporothrix schenckii sensu lato. It has gained importance in recent years due to its worldwide prevalence, recognition of multiple cryptic species within the originally described species, and its distinctive ecology, distribution, and epidemiology across the globe. In this review, we describe the current knowledge of the taxonomy, ecology, prevalence, molecular epidemiology, and outbreaks due to S. schenckii sensu lato. Despite its omnipresence in the environment, this fungus has remarkably diverse modes of infection and distribution patterns across the world. We have delved into the nuances of how sporotrichosis is intimately linked to different forms of human activities, habitats, lifestyles, and environmental and zoonotic interactions. The purpose of this review is to stimulate discussion about the peculiarities of this unique fungal pathogen and increase the awareness of clinicians and microbiologists, especially in regions of high endemicity, to its emergence and evolving presentations and to kindle further research into understanding the unorthodox mechanisms by which this fungus afflicts different human populations.

  6. Clinical Epidemiology Of Stroke

    Directory of Open Access Journals (Sweden)

    Nagaraja D

    2005-01-01

    Full Text Available Stroke is a huge public health problem because of its high morbidity and disability. The epidemiology of stroke is of relevance to construct practical paradigms to tackle this major health issue in the community. Recent data have shown that about 72-86% of strokes are ischemic, 9-18% are due to hemorrhage (intracerebral of subarachnoid and the rest are undefined. The risk factors for stroke are multiple and combined. At present, stroke is no more considered as unavoidable and untreatable. It is an emergency and specialized units and teams improve outcome and lower costs. Death related to stroke is declining in many countries and in both sexes. This decrease in multifactorial. The detection and more effective treatment of hypertension may play an important factor, as well as the improved medical care and improvement in diagnostic procedures. While stroke incidence appears stable and stroke mortality is slowly declining, the absolute magnitude of stroke is likely to grow over the next 30 years. as the population ages, the absolute number of stroke victims and demands on healthcare and other support systems is likely to increase substantially in the future. Keeping this in perspective, this chapter shall focus on the epidemiology of stroke in the world and in Indian, in particular.

  7. Molecular Epidemiology of Amebiasis

    Science.gov (United States)

    Ali, Ibne Karim M.; Clark, C. Graham; Petri, William A.

    2008-01-01

    Entamoeba histolytica, the causative agent of human amebiasis, remains a significant cause of morbidity and mortality in developing countries and is responsible for up to 100,000 deaths worldwide each year. Entamoeba dispar, morphologically indistinguishable from E. histolytica, is more common in humans in many parts of the world. Similarly Entamoeba moshkovskii, which was long considered to be a free-living ameba, is also morphologically identical to E. histolytica and E. dispar, and is highly prevalent in some E. histolytica endemic countries. However, the only species to cause disease in humans is E. histolytica. Most old epidemiological data on E. histolytica are unusable as the techniques employed do not differentiate between the above three Entamoeba species. Molecular tools are now available not only to diagnose these species accurately but also to study intra-species genetic diversity. Recent studies suggest that only a minority of all E. histolytica infections progress to development of clinical symptoms in the host and there exist population level differences between the E. histolytica strains isolated from the asymptomatic and symptomatic individuals. Nevertheless the underlying factors responsible for variable clinical outcome of infection by E. histolytica remain largely unknown. We anticipate that the recently completed E. histolytica genome sequence and new molecular techniques will rapidly advance our understanding of the epidemiology and pathogenicity of amebiasis. PMID:18571478

  8. The Epidemiology of Sarcopenia.

    Science.gov (United States)

    Dodds, Richard Matthew; Roberts, Helen Clare; Cooper, Cyrus; Sayer, Avan Aihie

    2015-01-01

    The aim of this review is to describe the epidemiology of sarcopenia, specifically prevalence, health outcomes, and factors across the life course that have been linked to its development. Sarcopenia definitions involve a range of measures (muscle mass, strength, and physical performance), which tend to decline with age, and hence sarcopenia becomes increasingly prevalent with age. Less is known about prevalence in older people in hospital and care homes, although it is likely to be higher than in community settings. The range of measures used, and the cutpoints suggested for each, presents a challenge for comparing prevalence estimates between studies. The importance of sarcopenia is highlighted by the range of adverse health outcomes that strength and physical performance (and to a lesser extent, muscle mass) have been linked to. This is shown most strikingly by the finding of increased all-cause mortality rates among those with weaker grip strength and slower gait speed. A life course approach broadens the window for our understanding of the etiology of sarcopenia and hence the potential intervention. An example is physical activity, with increased levels across midadulthood appearing to increase muscle mass and strength in early old age. Epidemiologic studies will continue to make an important contribution to our understanding of sarcopenia and possible avenues for intervention and prevention.

  9. Generalized derivations and general relativity

    CERN Document Server

    Heller, M; Pysiak, L; Sasin, W

    2013-01-01

    We construct differential geometry (connection, curvature, etc.) based on generalized derivations of an algebra A. Such a derivation, introduced by Bresar in 1991, is given by a linear mapping u: A -> A such that there exists a usual derivation d of A satisfying the generalized Leibniz rule u(a b) = u(a) b + a d(b) for all a,b in A. The generalized geometry "is tested" in the case of the algebra of smooth functions on a manifold. We then apply this machinery to study the generalized general relativity. We define the Einstein-Hilbert action and deduce from it Einstein's field equations. We show that for a special class of metrics containing, besides the usual metric components, only one non-zero term, the action reduces to O'Hanlon action that is a Brans-Dicke action with potential and with the parameter \\omega equal to zero. We also show that the generalized Einstein equations (with zero energy-stress tensor) are equivalent to those of the Kaluza-Klein theory satisfying a "modified cylinder condition" and hav...

  10. Epidemiological study on neurosis of internal medicine outpatient department in general hospital%大连市综合医院内科门诊神经症流行病学调查

    Institute of Scientific and Technical Information of China (English)

    孙月吉; 杜娟; 宛思莹; 刘启贵; 刘凤英; 曲芳; 陈锦波

    2008-01-01

    目的 了解综合科医院内科门诊神经症的发生率,探讨神经症发生特点.方法 采用了整群分层抽样方法,2006年7~8月,连续收集了3所大连市三级甲等综合科医院门诊病人600人.经神经症筛查量表筛查出阳性者,同时行DSM-Ⅳ确立诊断,符合诊断者309名作为研究对象.结果 内科门诊神经症病人的检出率约为57.43%(309例),非神经症约为42.56%(229例);其中焦虑210例,约占神经症总数的68%;广泛性焦虑115例,约37%;惊恐障碍67例,约占神经症总数的21.7%;抑郁伴发惊恐障碍28例,约占占神经症总数的9.6%.抑郁伴发广泛性焦,约占总数的14.2%.其他神经症患者83例,约占神经症总数的26.8%.重度抑郁障碍患者占总样本的3%;神经症患者不同诊断组之间的睡眠时间、累计就诊次数、累计医疗费用和累计就诊时间等均差异有显著性(P<0.01).自认病情态度和对内科医生诊断治疗的满意程度,各组之间差异有显著性(P=0.000).所调查的各组患者所经历的特殊检查(P=0.034)以及有无镇静止痛药物治疗均差异有显著性(P=0.000).结论 综合性医院内科门诊患者的精神障碍问题严重,其中以神经症为最常见.焦虑障碍在综合性医院内科门诊最常见.%Objective To investigate the prevalence status of neurosis among outpatients in internal medicine department of general hospital, and to find some characteristics of the neurosis. Methods 600 outpatients visiting the internal medicine department were investigated ,and they are from 3 general hospital in Dalian:seeond I-Iospital,Jinzhou hospital and second teaching hospital affiliated to Dalian medical university. 309 neurosis were selected with neurosis screening scale, and met the DSM-IV. Results Higher prevalence (57.43%) was found in neurosis of general hospital. The results showed that the prevalence rate of anxiety disorder is 68% within the neurosis, which included general anxiety (37.00%) and

  11. Molecular epidemiology studies on occupational and environmental exposure to mutagens and carcinogens, 1997-1999.

    OpenAIRE

    2000-01-01

    Molecular epidemiology is a new and evolving area of research, combining laboratory measurement of internal dose, biologically effective dose, biologic effects, and influence of individual susceptibility with epidemiologic methodologies. Biomarkers evaluated were selected according to basic scheme: biomarkers of exposure--metabolites in urine, DNA adducts, protein adducts, and Comet assay parameters; biomarkers of effect--chromosomal aberrations, sister chromatid exchanges, micronuclei, mutat...

  12. Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees.

    Science.gov (United States)

    Kenah, Eben; Britton, Tom; Halloran, M Elizabeth; Longini, Ira M

    2016-04-01

    Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology.

  13. Inventory parameters

    CERN Document Server

    Sharma, Sanjay

    2017-01-01

    This book provides a detailed overview of various parameters/factors involved in inventory analysis. It especially focuses on the assessment and modeling of basic inventory parameters, namely demand, procurement cost, cycle time, ordering cost, inventory carrying cost, inventory stock, stock out level, and stock out cost. In the context of economic lot size, it provides equations related to the optimum values. It also discusses why the optimum lot size and optimum total relevant cost are considered to be key decision variables, and uses numerous examples to explain each of these inventory parameters separately. Lastly, it provides detailed information on parameter estimation for different sectors/products. Written in a simple and lucid style, it offers a valuable resource for a broad readership, especially Master of Business Administration (MBA) students.

  14. The new epidemiology of nephrolithiasis.

    Science.gov (United States)

    Shoag, Jonathan; Tasian, Greg E; Goldfarb, David S; Eisner, Brian H

    2015-07-01

    Historically nephrolithiasis was considered a disease of dehydration and abnormal urine composition. However, over the past several decades, much has been learned about the epidemiology of this disease and its relation to patient demographic characteristics and common systemic diseases. Here we review the latest epidemiologic studies in the field.

  15. Cancer Epidemiology Data Repository (CEDR)

    Science.gov (United States)

    In an effort to broaden access and facilitate efficient data sharing, the Epidemiology and Genomics Research Program (EGRP) has created the Cancer Epidemiology Data Repository (CEDR), a centralized, controlled-access database, where Investigators can deposit individual-level de-identified observational cancer datasets.

  16. Epidemiology of infections in women.

    Science.gov (United States)

    Risser, Jan M H; Risser, William L; Risser, Amanda L

    2008-12-01

    This article describes the epidemiologic profiles of sexually transmitted infections seen in US women. We present a brief description of the infectious agent, describe the epidemiology of the infection among women in terms of race/ethnicity and age (if those data are available), and present what is known about the behavioral risk factors associated with acquisition.

  17. Epidemiological evidence in forensic pharmacovigilance.

    Science.gov (United States)

    Persaud, Nav; Healy, David

    2012-01-01

    Until recently epidemiological evidence was not regarded as helpful in determining cause and effect. It generated associations that then had to be explained in terms of bio-mechanisms and applied to individual patients. A series of legal cases surrounding possible birth defects triggered by doxylamine (Bendectin) and connective tissue disorders linked to breast implants made it clear that in some instances epidemiological evidence might have a more important role, but the pendulum swung too far so that epidemiological evidence has in recent decades been given an unwarranted primacy, partly perhaps because it suits the interests of certain stakeholders. Older and more recent epidemiological studies on doxylamine and other antihistamines are reviewed to bring out the ambiguities and pitfalls of an undue reliance on epidemiological studies.

  18. [Epidemiology of urinary lithiasis].

    Science.gov (United States)

    Joual, A; Rais, H; Rabii, R; el Mrini, M; Benjelloun, S

    1997-01-01

    The objective of this study was to analyse the epidemiological profile of urinary stones based on one thousand cases observed in our institution over a 10-year period. The mean age of the patients was 45 years and two-thirds of patients were males. The kidney was the commonest site of stones, in 57.8% of cases. The stone was radiopaque in 86.4% of cases and was a staghorn calculus in 12.2% of cases. An associated renal malformation was observed in 10.4% of cases. Urinary stones is therefore a common disease, essentially observed in a young population and characterized by recurrence. It therefore constitutes a public health problem and prevention consists of detecting recurrences and treating stone-inducing factors.

  19. [Epidemiology of tuberculosis].

    Science.gov (United States)

    Mjid, M; Cherif, J; Ben Salah, N; Toujani, S; Ouahchi, Y; Zakhama, H; Louzir, B; Mehiri-Ben Rhouma, N; Beji, M

    2015-01-01

    Tuberculosis is a contagious disease caused by Mycobacterium tuberculosis. It represents, according to World Health Organization (WHO), one of the most leading causes of death worldwide. With nearly 8 million new cases each year and more than 1 million deaths per year, tuberculosis is still a public health problem. Despite of the decrease in incidence, morbidity and mortality remain important partially due to co-infection with human immunodeficiency virus and emergence of resistant bacilli. All WHO regions are not uniformly affected by TB. Africa's region has the highest rates of morbidity and mortality. The epidemiological situation is also worrying in Eastern European countries where the proportion of drug-resistant tuberculosis is increasing. These regional disparities emphasize to develop screening, diagnosis and monitoring to the most vulnerable populations. In this context, the Stop TB program, developed by the WHO and its partner's, aims to reduce the burden of disease in accordance with the global targets set for 2015.

  20. Cancer epidemiology of woodworking.

    Science.gov (United States)

    Mohtashamipur, E; Norpoth, K; Lühmann, F

    1989-01-01

    The literature published between 1965 and 1989 on the cancer epidemiology of woodworking in furniture industries and carpentry shops in 17 countries is reviewed. Included are some unpublished data obtained through personal communication with epidemiologists or collected from doctoral dissertations. Of 5,785 cases with sino-nasal cancers, about 23% were found to be woodworkers. Dusty jobs, especially wood processing using high-speed machines, are mainly associated with the enhanced incidence of nasal adenocarcinomas. The latency periods of the latter tumors ranged from 7 to 69 years in five European countries. A variety of neoplasias of the respiratory, digestive, and urinary tracts as well as the hemopoietic and lymphatic systems, including Hodgkin's disease are reported to be significantly associated with occupational exposure to wood dust. These data suggest that the exposure to some types of wood dust might cause a systemic rather than local neoplastic disorder.

  1. The Epidemiology of Sarcoma

    Directory of Open Access Journals (Sweden)

    Burningham Zachary

    2012-10-01

    Full Text Available Abstract Sarcomas account for over 20% of all pediatric solid malignant cancers and less than 1% of all adult solid malignant cancers. The vast majority of diagnosed sarcomas will be soft tissue sarcomas, while malignant bone tumors make up just over 10% of sarcomas. The risks for sarcoma are not well-understood. We evaluated the existing literature on the epidemiology and etiology of sarcoma. Risks for sarcoma development can be divided into environmental exposures, genetic susceptibility, and an interaction between the two. HIV-positive individuals are at an increased risk for Kaposi’s sarcoma, even though HHV8 is the causative virus. Radiation exposure from radiotherapy has been strongly associated with secondary sarcoma development in certain cancer patients. In fact, the risk of malignant bone tumors increases as the cumulative dose of radiation to the bone increases (p for trend

  2. Epidemiology of gliomas.

    Science.gov (United States)

    Ostrom, Quinn T; Gittleman, Haley; Stetson, Lindsay; Virk, Selene M; Barnholtz-Sloan, Jill S

    2015-01-01

    Gliomas are the most common type of primary intracranial tumors. Some glioma subtypes cause significant mortality and morbidity that are disproportionate to their relatively rare incidence. A very small proportion of glioma cases can be attributed to inherited genetic disorders. Many potential risk factors for glioma have been studied to date, but few provide explanation for the number of brain tumors identified. The most significant of these factors includes increased risk due to exposure to ionizing radiation, and decreased risk with history of allergy or atopic disease. The potential effect of exposure to cellular phones has been studied extensively, but the results remain inconclusive. Recent genomic analyses, using the genome-wide association study (GWAS) design, have identified several inherited risk variants that are associated with increased glioma risk. The following chapter provides an overview of the current state of research in the epidemiology of intracranial glioma.

  3. Epidemiology of Helicobacter pylori infection.

    Science.gov (United States)

    Leja, Mārcis; Axon, Anthony; Brenner, Hermann

    2016-09-01

    This review of recent publications related to the epidemiology of Helicobacter pylori highlights the origin of the infection, its changing prevalence, transmission, and outcome. A number of studies have addressed the ancestor roots of the bacteria, and the first genomewide analysis of bacterial strains suggests that its coexistence with humans is more ancient than previously thought. As opposed to the generally declining prevalence of H. pylori (including China and Japan), in Sweden, the prevalence of atrophic gastritis in the young population has risen. The prevalence of the infection remains high in the indigenous populations of the Arctic regions, and reinfection rates are high. A high prevalence is permanently found in the Siberian regions of Russia as well. Several studies, some of which used multiplex serology, addressed prevalence of and risks associated with various H. pylori serotypes, thereby enabling more precise risk assessment. Transmission of H. pylori was discussed, specifically fecal-oral transmission and the use of well-water and other unpurified water. Finally, the long-term course of H. pylori infection was considered, with an estimated 89% of noncardia gastric cancer cases being attributable to the infection. © 2016 John Wiley & Sons Ltd.

  4. Epidemiology of acne vulgaris.

    Science.gov (United States)

    Bhate, K; Williams, H C

    2013-03-01

    Despite acne being an almost universal condition in younger people, relatively little is known about its epidemiology. We sought to review what is known about the distribution and causes of acne by conducting a systematic review of relevant epidemiological studies. We searched Medline and Embase to the end of November 2011. The role of Propionibacterium acnes in pathogenesis is unclear: antibiotics have a direct antimicrobial as well as an anti-inflammatory effect. Moderate-to-severe acne affects around 20% of young people and severity correlates with pubertal maturity. Acne may be presenting at a younger age because of earlier puberty. It is unclear if ethnicity is truly associated with acne. Black individuals are more prone to postinflammatory hyperpigmentation and specific subtypes such as 'pomade acne'. Acne persists into the 20s and 30s in around 64% and 43% of individuals, respectively. The heritability of acne is almost 80% in first-degree relatives. Acne occurs earlier and is more severe in those with a positive family history. Suicidal ideation is more common in those with severe compared with mild acne. In the U.S.A., the cost of acne is over 3 billion dollars per year in terms of treatment and loss of productivity. A systematic review in 2005 found no clear evidence of dietary components increasing acne risk. One small randomized controlled trial showed that low glycaemic index (GI) diets can lower acne severity. A possible association between dairy food intake and acne requires closer scrutiny. Natural sunlight or poor hygiene are not associated. The association between smoking and acne is probably due to confounding. Validated core outcomes in future studies will help in combining future evidence.

  5. Epidemiologia do desenvolvimento cognitivo de escolares em Jequié, Bahia, Brasil: procedimentos de avaliação e resultados gerais Epidemiology of schoolchildren's cognitive development in Jequié, Bahia State, Brazil: assessment procedures and general results

    Directory of Open Access Journals (Sweden)

    Darci Neves Santos

    2002-06-01

    Full Text Available Este artigo descreve metodologia, aplicação e utilidade do teste das Matrizes Progressivas de Raven e do Teste de Sondagem Intelectual (TSI, comparando-os ainda com o rendimento escolar do aluno, em Jequié, Bahia. O Raven, que avalia o raciocínio não-verbal, foi aplicado a 374 escolares (7 a 17 anos. Somente 231 TSI foram respondidos porque requeriam habilidades de leitura e escrita. Foram coletadas notas escolares para todos os participantes. Um questionário avaliando recursos da escola e perfil do professor foi respondido por duzentos professores. Os escores dos testes Raven e TSI apresentaram uma boa correlação entre si (r = 0,53, p This paper describes the methodology, applicability and utility of the Raven Progressive Matrix (Raven Test and the Brazilian Intellectual Probe (TSI, comparing them with school achievement in a typical medium-size urban community of Northeastern Brazil. 388 schoolchildren (7-17 years old were examined, with 371 Raven tests applied. Only 231 TSIs were completed, since 106 students were illiterate. School grades were obtained for all participants. A questionnaire evaluating school resources, and teacher profiles was answered by 200 teachers. Raven and TSI test scores were highly correlated (r = 0.53, p < 0.001, but both correlated weakly with overall school grade (r = 0.22, p < 0.001 and r = 0.12, p < 0.07 respectively. For individual school grades, the Raven scores showed statistically significant correlation with all subjects, while the Brazilian TSI presented statistically significant correlation only with geography, history and sciences. Boys' mean scores were higher than girls' for both the Raven and the TSI Tests, but for the school grades girls performed better. In general, level of cognitive development was below that expected for children in the age-group analyzed.

  6. A General Survey of Cause and Epidemiological Factors of Congenital Megacolon%先天性巨结肠症病因和流行因素的初步调查

    Institute of Scientific and Technical Information of China (English)

    李国光; 何尚浦; 王果; 林惠钧; 童尔昌

    1985-01-01

    @@ 我院在天门县卫生局和基层医务人员协助与支持下,于1982年对该县先巨症流行情况作了调查,并结合武汉市部分先巨症病例,对其病因学进行了初步探讨,结果报告如下: 调查方法 一、普查 对天门县在1980年、1981年和1982年1~9月份的两年零九个月期间新生儿中发生的先巨症进行普查.同时,普查了该县黄潭公社十一年来的发病情况.%A general survey made in Tainmen county in 1982 revealed the incidence of congenital megacolon was found to be 2.6 per 10,000 living infants in the past three years. No obvious correlation was found between the incidence and the consumption of farm insecticides upon statistical analysis. 90 cases of megacolon from Tainmen county and Wuhan city were studied at the same time. In comparison with the paired control group,there showed no cssential difference as to their maternal history of contact with farm insecticides,history of child-birth and to their birth weight or course of delivery. But the occurence of abnormal menstral cycle (half year before pregnancy),abdominal pain,trauma,mental stress and drug abuse of the diseased group during pregnancy revealed significant statistical difference With the control.

  7. Kinetics methods for clinical epidemiology problems.

    Science.gov (United States)

    Corlan, Alexandru Dan; Ross, John

    2015-11-17

    Calculating the probability of each possible outcome for a patient at any time in the future is currently possible only in the simplest cases: short-term prediction in acute diseases of otherwise healthy persons. This problem is to some extent analogous to predicting the concentrations of species in a reactor when knowing initial concentrations and after examining reaction rates at the individual molecule level. The existing theoretical framework behind predicting contagion and the immediate outcome of acute diseases in previously healthy individuals is largely analogous to deterministic kinetics of chemical systems consisting of one or a few reactions. We show that current statistical models commonly used in chronic disease epidemiology correspond to simple stochastic treatment of single reaction systems. The general problem corresponds to stochastic kinetics of complex reaction systems. We attempt to formulate epidemiologic problems related to chronic diseases in chemical kinetics terms. We review methods that may be adapted for use in epidemiology. We show that some reactions cannot fit into the mass-action law paradigm and solutions to these systems would frequently exhibit an antiportfolio effect. We provide a complete example application of stochastic kinetics modeling for a deductive meta-analysis of two papers on atrial fibrillation incidence, prevalence, and mortality.

  8. Generalized Probability Functions

    Directory of Open Access Journals (Sweden)

    Alexandre Souto Martinez

    2009-01-01

    Full Text Available From the integration of nonsymmetrical hyperboles, a one-parameter generalization of the logarithmic function is obtained. Inverting this function, one obtains the generalized exponential function. Motivated by the mathematical curiosity, we show that these generalized functions are suitable to generalize some probability density functions (pdfs. A very reliable rank distribution can be conveniently described by the generalized exponential function. Finally, we turn the attention to the generalization of one- and two-tail stretched exponential functions. We obtain, as particular cases, the generalized error function, the Zipf-Mandelbrot pdf, the generalized Gaussian and Laplace pdf. Their cumulative functions and moments were also obtained analytically.

  9. Voltage Step Point Detection and Parameter Identification of General Dynamic Load Model%通用动态负荷模型电压阶跃检测和参数辨识方法

    Institute of Scientific and Technical Information of China (English)

    王立地; 何昕; 朴在林

    2014-01-01

    It is of significance for parameter identification of general dynamic load model to determine the position of equivalent step point in gradually-varying voltage signal and adopt reasonable signal preprocessing method. To meet the requirement of the dynamic load modeling experiment, the equivalent voltage step is adopted to take the place of gradually varied voltage signal, and the clustering analysis is led into the detection of equivalent voltage step point. Considering distribution characteristic of numerical value of voltage in a certain time interval and combining with wavelet denoising, the load signal is preprocessed;based on the platform of MATLAB and by means of development tool of graphics user interface (GUI) the parameter identification of general dynamic active load model is implemented. Experimental results show that, with the clustering method, the gradually-varying voltage step point can be effectively detected on the basis of the signal processed by average filtering and wavelet denoising;and utilizing the signal denoised by bior3.7 wavelet with the 4-th level decomposition for parameter identification, the obtained result is of the highest stability. The proposed method is suitable for load modeling with power recovery characteristic and off-line analysis under the condition of gradually-varied voltage due to manually changing the position of transformer tap and so on.%如何确定渐变电压信号等效阶跃点位置和采取合理的信号预处理方法对通用动态负荷模型参数辨识有重要影响。针对动态负荷建模试验的需要,利用等效电压阶跃来代替电压渐变信号,把聚类分析引入等效电压阶跃点检测中。在一定时间区间内考虑电压数值的分布特性,结合小波去噪进行负荷信号预处理,基于MATLAB平台,借助GUI(图形用户界面)开发手段,实现了通用动态有功负荷模型的参数辨识。实验结果表明:采用聚类分析方法,可以有效

  10. Sewage epidemiology and illicit drug research: the development of ethical research guidelines

    NARCIS (Netherlands)

    J Prichard; W. Hall; P. de Voogt; E. Zuccato

    2014-01-01

    Aims To discuss the need to develop ethical guidelines for researchers using sewage epidemiology to monitor drug use in the general population and specific precincts, including prisons, schools and workplaces. Method Describe current applications of sewage epidemiology, identify potential ethical ri

  11. The European concerted action on air pollution epidemiology

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann-Liebrich, U. [Basel Univ. (Switzerland). Inst. for Social and Preventive Medicine

    1995-12-31

    The European Concerted Action on Air Pollution Epidemiology was started in 1990 with the aim of bringing together European researchers in the field and improving research through collaboration and by preparing documents which would help to this end and by organizing workshops. A further aim was to stimulate cooperative research. Air pollution epidemiology investigates human effects of community air pollution by epidemiological methods. Epidemiology in general investigates the distribution and determinants of health-related states and events in populations. Diseases in which air pollution may play a significant role are mainly diseases of the respiratory system, for example chronic non-specific lung disease and lung cancer. Most diseases caused by air pollution can also be caused by other factors. Air pollution epidemiology is therefore specific in the expo variable (community air pollution) rather than in the type of health effects being studied. Air pollution epidemiology is beset with some specially challenging difficulties: ubiquitous exposure and as a consequence limited heterogeneity in exposure, low relative risks, few or specific health end points, and strong confounding. Further on the exposure-effect relationship is complicated by assumptions inherent to different study designs which relate to the exposure duration necessary to produce a certain health effect. In reports and workshops the concerted action tries to propose strategies to deal with these problems. (author)

  12. Self-organized criticality in human epidemiology

    Science.gov (United States)

    Stollenwerk, Nico

    2005-07-01

    As opposed to most sociological fields, data are available in good quality for human epidemiology, describing the interaction between individuals being susceptible to or infected by a disease. Mathematically, the modelling of such systems is done on the level of stochastic master equations, giving likelihood functions for real live data. We show in a case study of meningococcal disease, that the observed large fluctuations of outbreaks of disease among the human population can be explained by the theory of accidental pathogens, leading the system towards a critical state, characterized by power laws in outbreak distributions. In order to make the extremely difficult parameter estimation close to a critical state with absorbing boundary possible, we investigate new algorithms for simulation of the disease dynamics on the basis of winner takes all strategies, and combine them with previously developed parameter estimation schemes.

  13. Epidemiology of gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Katherine D Crew; Alfred I Neugut

    2006-01-01

    The incidence and mortality of gastric cancer have fallen dramatically in US and elsewhere over the past several decades. Nonetheless, gastric cancer remains a major public health issue as the fourth most common cancer and the second leading cause of cancer death worldwide. Demographic trends differ by tumor location and histology. While there has been a marked decline in distal, intestinal type gastric cancers, the incidence of proximal, diffuse type adenocarcinomas of the gastric cardia has been increasing, particularly in the Western countries. Incidence by tumor sub-site also varies widely based on geographic location, race, and socioeconomic status. Distal gastric cancer predominates in developing countries, among blacks, and in lower socioeconomic groups, whereas proximal tumors are more common in developed countries, among whites, and in higher socio-economic classes. Diverging trends in the incidence of gastric cancer by tumor location suggest that they may represent two diseases with different etiologies. The main risk factors for distal gastric cancer include Helicobacter pylori (H pylori) infection and dietary factors, whereas gastroesophageal reflux disease and obesity play important roles in the development of proximal stomach cancer. The purpose of this review is to examine the epidemiology and risk factors of gastric cancer, and to discuss strategies for primary prevention.

  14. Epidemiology of delayed ejaculation.

    Science.gov (United States)

    Di Sante, Stefania; Mollaioli, Daniele; Gravina, Giovanni Luca; Ciocca, Giacomo; Limoncin, Erika; Carosa, Eleonora; Lenzi, Andrea; Jannini, Emmanuele A

    2016-08-01

    A large body of literature on diminished ejaculatory disorders has been generated without the use of a clear diagnostic definition. Many studies have not distinguished between the orgasm and ejaculation disorders leading to doubtful results. Delayed ejaculation (DE) is one of the diminished ejaculatory disorders, which range from varying delays in ejaculatory latency to a complete inability to ejaculate. The present review is aimed at providing a comprehensive overview of the current knowledge on the definition and epidemiology of diminished ejaculatory disorders. We focus on the acquired diseases, such as benign prostatic hyperplasia (BPH) and specific drug regimens that may cause an iatrogenic form of ejaculatory disorder. In addition, the impact of aging is discussed since the prevalence of DE appears to be moderately but positively related to age. Finally, we also focus on the importance of the hormonal milieu on male ejaculation. To date, evidence on the endocrine control of ejaculation is derived from small clinical trials, but the evidence suggests that hormones modulate the ejaculatory process by altering its overall latency.

  15. Epidemiology of severe trauma.

    Science.gov (United States)

    Alberdi, F; García, I; Atutxa, L; Zabarte, M

    2014-12-01

    Major injury is the sixth leading cause of death worldwide. Among those under 35 years of age, it is the leading cause of death and disability. Traffic accidents alone are the main cause, fundamentally in low- and middle-income countries. Patients over 65 years of age are an increasingly affected group. For similar levels of injury, these patients have twice the mortality rate of young individuals, due to the existence of important comorbidities and associated treatments, and are more likely to die of medical complications late during hospital admission. No worldwide, standardized definitions exist for documenting, reporting and comparing data on severely injured trauma patients. The most common trauma scores are the Abbreviated Injury Scale (AIS), the Injury Severity Score (ISS) and the Trauma and Injury severity Score (TRISS). Documenting the burden of injury also requires evaluation of the impact of post-trauma impairments, disabilities and handicaps. Trauma epidemiology helps define health service and research priorities, contributes to identify disadvantaged groups, and also facilitates the elaboration of comparable measures for outcome predictions.

  16. Molecular epidemiology of giardiasis.

    Science.gov (United States)

    Cacciò, Simone M; Ryan, Una

    2008-08-01

    Giardia duodenalis is a widespread parasite of mammalian species, including humans. Due to its invariant morphology, investigation on aspects such as host specificity and transmission patterns requires a direct genetic characterization of cysts/trophozoites from host samples. A number of molecular assays have been developed to help unravel the complex epidemiology of this infection. A coherent picture has emerged from those studies, indicating the existence of seven genetic groups (or assemblages), two of which (A and B) are found in both humans and animals, whereas the remaining five (C-G) are host-specific. Sequence-based surveys have identified a number of genotypes within assemblages A and B in animal species, some of which may have zoonotic potential. Recently, however, molecular approaches have been complicated by the recognition of intra-isolate sequence heterogeneity (i.e., "mixed templates", that affects identification of subtypes within each assemblage), and by the unreliable assignment of isolates to G. duodenalis assemblages generated by different genetic markers. This raises concerns about previous interpretation of genotyping data, especially when single genetic markers have been used. The mechanisms that may be responsible for these findings, including allelic sequence heterozygosity and meiotic recombination, are discussed.

  17. Microtia: epidemiology and genetics.

    Science.gov (United States)

    Luquetti, Daniela V; Heike, Carrie L; Hing, Anne V; Cunningham, Michael L; Cox, Timothy C

    2012-01-01

    Microtia is a congenital anomaly of the ear that ranges in severity from mild structural abnormalities to complete absence of the ear, and can occur as an isolated birth defect or as part of a spectrum of anomalies or a syndrome. Microtia is often associated with hearing loss and patients typically require treatment for hearing impairment and surgical ear reconstruction. The reported prevalence varies among regions, from 0.83 to 17.4 per 10,000 births, and the prevalence is considered to be higher in Hispanics, Asians, Native Americans, and Andeans. The etiology of microtia and the cause of this wide variability in prevalence are poorly understood. Strong evidence supports the role of environmental and genetic causes for microtia. Although some studies have identified candidate genetic variants for microtia, no causal genetic mutation has been confirmed. The application of novel strategies in developmental biology and genetics has facilitated elucidation of mechanisms controlling craniofacial development. In this paper we review current knowledge of the epidemiology and genetics of microtia, including potential candidate genes supported by evidence from human syndromes and animal models. We also discuss the possible etiopathogenesis in light of the hypotheses formulated to date: Neural crest cells disturbance, vascular disruption, and altitude.

  18. TUBERCULOSIS: EPIDEMIOLOGY AND CONTROL

    Directory of Open Access Journals (Sweden)

    Giorgia Sulis

    2014-10-01

    Full Text Available Tuberculosis (TB is a major public health concern worldwide: despite a regular, although slow, decline in incidence over the last decade, as many as 8.6 million new cases and 1.3 million deaths were estimated to have occurred in 2012. TB is by all means a poverty-related disease, mainly affecting the most vulnerable populations in the poorest countries. The presence of multidrug-resistant strains of M. tuberculosis in most countries, with some where prevalence is high, is among the major challenges for TB control, which may hinder recent achievements especially in some settings. Early TB case detection especially in resource-constrained settings and in marginalized groups remains a challenge, and about 3 million people are estimated to remain undiagnosed or not notified and untreated. The World Health Organization (WHO has recently launched the new global TB strategy for the “post-2015 era” aimed at “ending the global TB epidemic” by 2035, based on the three pillars that emphasize patient-centred TB care and prevention, bold policies and supportive systems, and intensified research and innovation. This paper aims to provide an overview of the global TB epidemiology as well as of the main challenges that must be faced to eliminate the disease as a public health problem everywhere.

  19. Pemphigus: Epidemiology and Pathogenesis

    Directory of Open Access Journals (Sweden)

    Yelda Karıncaoğlu

    2008-08-01

    Full Text Available Pemphigus, a group of bullous diseases affecting the oral mucosa and the skin, is caused by antibody-mediated autoimmune reaction to desmogleins (Dsg, desmosomal transmembrane glycoproteins, leading to acantholysis. Pemphigus has a worldwide distribution but the incidence in patients of Jewish origin is higher. The disease has a peak incidence of occurrence between the 4th and 6th decades. While various environmental factors have been implicated as triggering agents, HLA association is probably the most important predisposing factor. Pemphigus, is caused by antibody-mediated autoimmune reaction to desmosomal cadherins, Dsg1, and Dsg3. Recent molecular studies have shown that acantholysis can occur also in the presence of antibodies against 9a nicotinic acetylcholine receptor. Pemphigus is currently divided into three distinct varieties, i.e., pemphigus vulgaris (PV, pemphigus foliaceus (PF and other variants of pemphigus, depending on clinical features, the level of separation in the epidermis, and immunologic characteristics of auto-antigens. Blistering pathogenesis differ for each of the types of pemphigus. PV is characterized by IgG autoantibodies against Dsg 3, whereas the target of PF is Dsg1, although about 50% of PV patients also have Dsg1 autoantibodies. Lesion distribution is related to the location of the antigen (Dgs 3 and/or Dgs 1 in the epithelium and specific autoantibody production. This article reviews the epidemiology and pathogenesis of pemphigus.

  20. Metabolomics and Epidemiology Working Group

    Science.gov (United States)

    The Metabolomics and Epidemiology (MetEpi) Working Group promotes metabolomics analyses in population-based studies, as well as advancement in the field of metabolomics for broader biomedical and public health research.

  1. Genomic Resources for Cancer Epidemiology

    Science.gov (United States)

    This page provides links to research resources, complied by the Epidemiology and Genomics Research Program, that may be of interest to genetic epidemiologists conducting cancer research, but is not exhaustive.

  2. Sample Cancer Epidemiology Grant Applications

    Science.gov (United States)

    The National Cancer Institute frequently receives questions from investigators for examples of successfully funded grant applications. Several investigators agreed to let the Epidemiology and Genomics Research Program post excerpts of their grant applications online.

  3. Molecular epidemiology of heartwater (Ehrlichia ruminantium infection) in The Gambia

    NARCIS (Netherlands)

    Faburay, B.

    2007-01-01

    Heartwater is caused by Ehrlichia ruminantium and transmitted by ticks of the genus Amblyomma. It occurs in sub-Saharan Africa and in the Caribbean and affects domestic ruminants. There is general lack of information on the epidemiology of the disease in The Gambia. Results of a countrywide

  4. Molecular epidemiology of heartwater (Ehrlichia ruminantium infection) in The Gambia

    NARCIS (Netherlands)

    Faburay, B.

    2007-01-01

    Heartwater is caused by Ehrlichia ruminantium and transmitted by ticks of the genus Amblyomma. It occurs in sub-Saharan Africa and in the Caribbean and affects domestic ruminants. There is general lack of information on the epidemiology of the disease in The Gambia. Results of a countrywide serologi

  5. Sociocultural epidemiology: an essential approach.

    Directory of Open Access Journals (Sweden)

    Paul Hersch-Martínez

    2013-09-01

    Full Text Available The necessity of an inclusive epidemiological approach, capable to attend the diverse dimensions involved in health damage as a reflective phenomenon of society is analyzed. The range of perspectives involved requires an inclusive methodological scope and applicative channels, in order to deal with sanitary realities systematically related to culture and social organization. Some constitutive elements of sociocultural epidemiology are underlined, shaping an operative proposal that can enhance the relationship between disciplines and sectors regarding specific outstanding public health problems.

  6. Understanding disease control: influence of epidemiological and economic factors.

    Directory of Open Access Journals (Sweden)

    Katarzyna Oleś

    Full Text Available We present a model of disease transmission on a regular and small world network and compare different control options. Comparison is based on a total cost of epidemic, including cost of palliative treatment of ill individuals and preventive cost aimed at vaccination or culling of susceptible individuals. Disease is characterized by pre-symptomatic phase, which makes detection and control difficult. Three general strategies emerge: global preventive treatment, local treatment within a neighborhood of certain size and only palliative treatment with no prevention. While the choice between the strategies depends on a relative cost of palliative and preventive treatment, the details of the local strategy and, in particular, the size of the optimal treatment neighborhood depend on the epidemiological factors. The required extent of prevention is proportional to the size of the infection neighborhood, but depends on time till detection and time till treatment in a non-nonlinear (power law. The optimal size of control neighborhood is also highly sensitive to the relative cost, particularly for inefficient detection and control application. These results have important consequences for design of prevention strategies aiming at emerging diseases for which parameters are not nessecerly known in advance.

  7. Epidemiology of hepatitis B virus in Bangladeshi general population

    Institute of Scientific and Technical Information of China (English)

    Mamun-Al Mahtab; Salimur Rahman; Md. Fazal Karim; Mobin Khan; Graham Foster; Susannah Solaiman; Shahrin Afroz

    2008-01-01

    BACKGROUND: Hepatitis B virus (HBV) is encountered sporadically the year round in Bangladesh. It results in a wide range of liver diseases, with asymptomatic acute hepatitis at one end to hepatocellular carcinoma (HCC) at the other end of the spectrum. METHODS: All 1018 individuals of different age groups and sex with varied religious, educational and social backgrounds were tested for HBsAg by ELISA. The positive samples were further tested by ELISA for HBeAg. Before testing, blood samples were preserved at-20℃. The study was conducted in a semi-urban location on the outskirts of Dhaka. RESULTS: Of the 1018 individuals, 5.5%tested positive for HBsAg. None were tested positive for anti-HCV. Among the HBsAg-positive population, 58.93% were HBeAg-positive and the rest 41.07% HBeAg-negative. There was a male predominance and those who were tested positive were mostly between 16 and 50 years of age. Major risk factors for exposure to HBV appeared to be injudicious use of injectable medications, treatment by unqualiifed, traditional practitioners, mass-vaccination against cholera and smallpox, barbers and body piercing. CONCLUSION: HBV remains a major cause of morbidity and mortality in Bangladesh and we have a long way to go before we may bid farewell to this deadly menace.

  8. Generalized Grueneisen parameters and the low temperature thermal expansion of high-T{sub c} superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}

    Energy Technology Data Exchange (ETDEWEB)

    Jayachandran, K.P.; Menon, C.S. [School of Pure and Applied Physics, Mahatma Gandhi University, Kottayam, Kerala (India)

    2002-01-14

    The anisotropy of low temperature thermal expansion of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} (Bi 2212) is analysed theoretically using quasiharmonic theory of thermal expansion. Vibrational anharmonicity as determined by the generalized Grueneisen parameters (GPs){gamma}'{sub j} and {gamma}''{sub j} of the various normal mode frequencies of the lattice has been studied. {gamma}'{sub j} refers to change in frequencies due to a uniform areal strain perpendicular to the c-axis and {gamma}''{sub j} to the change in frequencies due to a uniform areal strain along the c-axis of the Bi 2212 crystal. The generalized GPs are calculated using the second-order elastic constants (SOECs) and third-order elastic constants (TOECs). The SOECs and TOECs are calculated using deformation theory. The strain energy density {phi} is estimated by taking into account the interactions of nine nearest neighbours of each atom in the unit cell of Bi 2212. The energy density thus obtained is compared with the strain-dependent lattice energy from the continuum model approximation to obtain the complete set of non-vanishing SOECs and TOECs of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}. Generally, {gamma}''{sub j} exhibits higher values than {gamma}'{sub j}. Thus the crystal is more anharmonic along the c-axis than in the ab-plane. The longitudinal acoustic mode 3'' is the most anisotropic of all the mode gammas. The transverse acoustic mode {gamma}{sub 1}' attains negative values from {theta}=25 deg. to 55 deg., where {theta} is the angle made by the direction of wave propagation with the c-axis of the crystal Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}. The low temperature limit of the effective Grueneisen functions {gamma}-bar{sub parall}(0), which is parallel to the c-axis of Bi 2212, is almost double the value of {gamma}-bar {sub perpendicular} (0). Hence the discrepancy in the vibrational anharmonicity along the c-axis and along the CuO{sub 2

  9. Optomechanical parameter estimation

    CERN Document Server

    Ang, Shan Zheng; Bowen, Warwick P; Tsang, Mankei

    2013-01-01

    We propose a statistical framework for the problem of parameter estimation from a noisy optomechanical system. The Cram\\'er-Rao lower bound on the estimation errors in the long-time limit is derived and compared with the errors of radiometer and expectation-maximization (EM) algorithms in the estimation of the force noise power. When applied to experimental data, the EM estimator is found to have the lowest error and follow the Cram\\'er-Rao bound most closely. With its ability to estimate most of the system parameters, the EM algorithm is envisioned to be useful for optomechanical sensing, atomic magnetometry, and classical or quantum system identification applications in general.

  10. Relative risk regression analysis of epidemiologic data.

    Science.gov (United States)

    Prentice, R L

    1985-11-01

    Relative risk regression methods are described. These methods provide a unified approach to a range of data analysis problems in environmental risk assessment and in the study of disease risk factors more generally. Relative risk regression methods are most readily viewed as an outgrowth of Cox's regression and life model. They can also be viewed as a regression generalization of more classical epidemiologic procedures, such as that due to Mantel and Haenszel. In the context of an epidemiologic cohort study, relative risk regression methods extend conventional survival data methods and binary response (e.g., logistic) regression models by taking explicit account of the time to disease occurrence while allowing arbitrary baseline disease rates, general censorship, and time-varying risk factors. This latter feature is particularly relevant to many environmental risk assessment problems wherein one wishes to relate disease rates at a particular point in time to aspects of a preceding risk factor history. Relative risk regression methods also adapt readily to time-matched case-control studies and to certain less standard designs. The uses of relative risk regression methods are illustrated and the state of development of these procedures is discussed. It is argued that asymptotic partial likelihood estimation techniques are now well developed in the important special case in which the disease rates of interest have interpretations as counting process intensity functions. Estimation of relative risks processes corresponding to disease rates falling outside this class has, however, received limited attention. The general area of relative risk regression model criticism has, as yet, not been thoroughly studied, though a number of statistical groups are studying such features as tests of fit, residuals, diagnostics and graphical procedures. Most such studies have been restricted to exponential form relative risks as have simulation studies of relative risk estimation

  11. CLINICAL, EPIDEMIOLOGICAL AND MYCOLOGICA

    Directory of Open Access Journals (Sweden)

    Ratheesh T

    2014-09-01

    Full Text Available BACKGROUND: Tinea versicolor is a chronic, mild, usually asymptomatic infection of the stratum corneum. The lesions are discrete or confluent and appear as discolored or hypo pigmented areas of the skin. The affected areas are located principally on the chest, abdomen, upper extremities and back. The etiologic agent is the lipophilic yeast Pityrosporum orbiculare, part of the normal flora of the human skin. This study is undertaken to know “clinical, patterns of the disease with respect to morphology and distribution, associated conditions and epidemiological factors like age, sex distribution and seasonal variation of the disease”. METHODS: Two hundred patients of tinea versicolor were selected. Patients belonging to the age group of above 10 years and below 60 years belonging to both sexes were selected and included in the study group after taking consent. A detailed history was taken with particular reference to onset, duration, symptoms and treatment taken and were recorded. Factors like – seasonal variation, family history and presence of any associated illnesses was also noted. A thorough clinical examination was done with reference to the location, the color, the extent of the lesions, the margins, the type of lesions and the details were recorded. Potassium hydroxide (KOH examination and Wood’s lamp examination were done in all the patients before therapy. RESULTS: Out of 200 patients, majority of them belong to 2nd and 3rd decade of life (72%. The Male: Female ratio was 1.5:1. There was a family history of 16%. The trunk was the most common site involved. Majority of the patients had exacerbation in summer. The most common associated dermatoses were acne vulgaris, immunosuppression and infections. INTERPRETATION AND CONCLUSION: Tinea versicolor is a disease of worldwide distribution, although it is significantly more common in humid and tropical climates. The true incidence cannot be estimated precisely because the disease is

  12. Supergranular Parameters

    Science.gov (United States)

    Udayashankar, Paniveni

    2016-07-01

    I study the complexity of supergranular cells using intensity patterns from Kodaikanal solar observatory. The chaotic and turbulent aspect of the solar supergranulation can be studied by examining the interrelationships amongst the parameters characterizing supergranular cells namely size, horizontal flow field, lifetime and physical dimensions of the cells and the fractal dimension deduced from the size data. The findings are supportive of Kolmogorov's theory of turbulence. The Data consists of visually identified supergranular cells, from which a fractal dimension 'D' for supergranulation is obtained according to the relation P α AD/2 where 'A' is the area and 'P' is the perimeter of the supergranular cells. I find a fractal dimension close to about 1.3 which is consistent with that for isobars and suggests a possible turbulent origin. The cell circularity shows a dependence on the perimeter with a peak around (1.1-1.2) x 105 m. The findings are supportive of Kolmogorov's theory of turbulence.

  13. False positives in cancer epidemiology.

    Science.gov (United States)

    McLaughlin, Joseph K; Tarone, Robert E

    2013-01-01

    A recent attempt to estimate the false-positive rate for cancer epidemiology studies is based on agents in International Agency for Research on Cancer (IARC) category 3 (agent not classifiable as to its carcinogenicity to humans) in the IARC Monographs Program. The estimation method is critiqued regarding biases caused by its reliance on the IARC classification criteria for assessing carcinogenic potential. The privileged position given to epidemiologic studies by the IARC criteria ensures that the percentage of positive epidemiologic studies for an agent will depend strongly on the IARC category to which the agent is assigned. Because IARC category 3 is composed of agents with the lowest-assessed carcinogenic potential to which the estimation approach in question could be applied, a spuriously low estimated false-positive rate was necessarily the outcome of this approach. Tendentious estimation approaches like that employed will by necessity produce spuriously low and misleading false positive rates. The recently reported estimates of the false-positive rate in cancer epidemiology are seriously biased and contribute nothing substantive to the literature on the very real problems related to false-positive findings in epidemiology.

  14. [Epidemiology of mood disorders].

    Science.gov (United States)

    Rouillon, Frédéric

    2008-02-29

    The 12 months and lifetime prevalence of is respectively 5 and 9% in the general population; moreover 10 to 20% of general practice patients are depressed. Depression is involved in about 40 to 80% of suicide and induces one of the greatest social burden. Mood disorders are more frequent in women, individual living alone and people with low socio-economic level. Risk factors are stressfull life events, biological vulnerability (genetic factors), somatic diseases, psychiatric comorbidity including personality disorders and addictions. Depressive disorders are underdiagnosed and undertreated despite efficacious pharmacological and psychotherapeutic strategies in their treatment. It's the reason why public health programs to prevent depression have been promoted by many countries like European Alliance against Depression. Their efficacy must be evaluated as their cost-efficiency.

  15. Topics in General Relativity theory: Gravitational-wave measurements of black-hole parameters; gravitational collapse of a cylindrical body; and classical-particle evolution in the presence of closed, timelike curves

    Science.gov (United States)

    Echeverria, Fernando

    I study three different topics in general relativity. The first study investigates the accuracy with which the mass and angular momentum of a black hole can be determined by measurements of gravitational waves from the hole, using a gravitational-wave detector. The black hole is assumed to have been strongly perturbed and the detector measures the waves produced by its resulting vibration and ring-down. The uncertainties in the measured parameters arise from the noise present in the detector. It is found that the faster the hole rotates, the more accurate the measurements will be, with the uncertainty in the angular momentum decreasing rapidly with increasing rotation speed. The second study is an analysis of the gravitational collapse of an infinitely long, cylindrical dust shell, an idealization of more realistic, finite-length bodies. It is found that the collapse evolves into a naked singularity in finite time. Analytical expressions for the variables describing the collapse are found at late times, near the singularity. The collapse is also followed, with a numerical simulation, from the start until very close to the singularity. The singularity is found to be strong, in the sense that an observer riding on the shell will be infinitely stretched in one direction and infinitely compressed in another. The gravitational waves emitted from the collapse are also analyzed. The last study focuses on the consequences of the existence of closed time like curves in a worm hole space time. One might expect that such curves might cause a system with apparently well-posed initial conditions to have no self-consistent evolution. We study the case of a classical particle with a hard-sphere potential, focusing attention on initial conditions for which the evolution, if followed naively, is self-inconsistent: the ball travels to the past through the worm hole colliding with its younger self, preventing itself from entering the worm hole. We find, surprisingly, that for all

  16. JPRS Report, Epidemiology.

    Science.gov (United States)

    2007-11-02

    Market Bans Export of UK Cows To Combat Disease [Godfrey Brown; London THE DAILY TELEGRAPH, 27 Jul 89] 28 JPRS-TEP-89-016 28 SEPTEMBER 1989 SUB...gathered that ’Stebatin’ injection used to cure kalaazar has been scanty in the market . Taking advan- tage of this situation some dishonest druggists...population in need of money. It is generally believed that professional blood donors in Gujarat include drug addicts, hotel boys, hostel students or

  17. Propaganda de medicamentos para grande público: parâmetros conceituais de uma prática produtora de risco Drug advertising to the general public: conceptual parameters of a risk producer practice

    Directory of Open Access Journals (Sweden)

    Álvaro César Nascimento

    2010-11-01

    Full Text Available Este artigo analisa alguns conceitos relativos a marketing, propaganda, medicamento, regulação e manipulação, discutindo parâmetros éticos e de vigilância sanitária relativos à prática da propaganda de medicamentos para o grande público. O foco deste trabalho é a análise das contradições, desde o ponto de vista conceitual, da prática da propaganda farmacêutica como instrumento de elevação das vendas e conquista de mercados versus a política de uso racional de medicamentos. Estudos acadêmicos e a monitoração da propaganda farmacêutica realizada pela Agência Nacional de Vigilância Sanitária demonstram que os conteúdos das peças publicitárias de medicamentos direcionadas ao grande público superestimam as qualidades do produto, enaltecem quase exclusivamente seus benefícios, colocando-os em uma posição central no processo terapêutico; e omitem os riscos inerentes à sua utilização e exageram suas qualidades, às vezes duvidosas. Mais que se debruçar sobre propostas reguladoras que objetivariam criar constrangimentos a esta prática, este artigo discute a impossibilidade, considerando-se os interesses da saúde pública, da convivência de interesses tão díspares quanto os do marketing - que busca sempre expandir mercados - e das políticas de uso correto, racional e seguro de medicamentos.This article analyzes some concepts relating to marketing, advertising, medications, regulation and manipulation. It discusses ethical and health surveillance parameters of drugs advertising for the general public. The focus of this work is the analysis of contradictions from a conceptual point of view between the practice of pharmaceutical advertising as a tool for the increase of sales and the conquest of markets versus the policy of rational use of medicines. Academic studies and monitoring of drugs advertising conducted by the National Health Surveillance Agency show that the contents of the advertising pieces oriented

  18. General introduction

    NARCIS (Netherlands)

    Emmelkamp, P.; Ehring, T.; Emmelkamp, P.; Ehring, T.

    2014-01-01

    This introductory chapter of this two-volume handbook commences with an overview of the book, which is aimed to provide a comprehensive overview of the current knowledge on the phenomenology, classification, epidemiology, etiology, and clinical management of anxiety disorders. Whereas Volume 1

  19. Epidemiology of stuttering: 21st century advances.

    Science.gov (United States)

    Yairi, Ehud; Ambrose, Nicoline

    2013-06-01

    Epidemiological advances in stuttering during the current century are reviewed within the perspectives of past knowledge. The review is organized in six sections: (a) onset, (b) incidence, (c) prevalence, (d) developmental paths, (e) genetics and (f) subtypes. It is concluded that: (1) most of the risk for stuttering onset is over by age 5, earlier than has been previously thought, with a male-to-female ratio near onset smaller than what has been thought, (2) there are indications that the lifespan incidence in the general population may be higher than the 5% commonly cited in past work, (3) the average prevalence over the lifespan may be lower than the commonly held 1%, (4) the effects of race, ethnicity, culture, bilingualism, and socioeconomic status on the incidence/prevalence of stuttering remain uncertain, (5) longitudinal, as well as incidence and prevalence studies support high levels of natural recovery from stuttering, (6) advances in biological genetic research have brought within reach the identification of candidate genes that contribute to stuttering in the population at large, (7) subtype-differentiation has attracted growing interest, with most of the accumulated evidence supporting a distinction between persistent and recovered subtypes. Readers will be exposed to a summary presentation of the most recent data concerning basic epidemiological factors in stuttering. Most of these factors also pertain to children's risks for experiencing stuttering onset, as well as risks for persistency. The article also aims to increase awareness of the implications of the information to research, and professional preparation that meets the epidemiology of the disorder. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Defending legitimate epidemiologic research: combating Lysenko pseudoscience.

    Science.gov (United States)

    Enstrom, James E

    2007-10-10

    This analysis presents a detailed defense of my epidemiologic research in the May 17, 2003 British Medical Journal that found no significant relationship between environmental tobacco smoke (ETS) and tobacco-related mortality. In order to defend the honesty and scientific integrity of my research, I have identified and addressed in a detailed manner several unethical and erroneous attacks on this research. Specifically, I have demonstrated that this research is not "fatally flawed," that I have not made "inappropriate use" of the underlying database, and that my findings agree with other United States results on this relationship. My research suggests, contrary to popular claims, that there is not a causal relationship between ETS and mortality in the U.S. responsible for 50,000 excess annual deaths, but rather there is a weak and inconsistent relationship. The popular claims tend to damage the credibility of epidemiology. In addition, I address the omission of my research from the 2006 Surgeon General's Report on Involuntary Smoking and the inclusion of it in a massive U.S. Department of Justice racketeering lawsuit. I refute erroneous statements made by powerful U.S. epidemiologists and activists about me and my research and I defend the funding used to conduct this research. Finally, I compare many aspect of ETS epidemiology in the U.S. with pseudoscience in the Soviet Union during the period of Trofim Denisovich Lysenko. Overall, this paper is intended to defend legitimate research against illegitimate criticism by those who have attempted to suppress and discredit it because it does not support their ideological and political agendas. Hopefully, this defense will help other scientists defend their legitimate research and combat "Lysenko pseudoscience."

  1. Epidemiología de campo y epidemiología social Field epidemiology and social epidemiology

    Directory of Open Access Journals (Sweden)

    Javier Segura del Pozo

    2006-03-01

    Full Text Available Mediante la comparación de la epidemiología de campo y la epidemiología social, se pretende reflexionar sobre los imaginarios no explícitos que operan en ambos ámbitos, necesariamente convergentes, sobre los obstáculos de la práctica epidemiológica actual para alcanzar su función social y sobre la necesidad de cambiar las bases epistemológicas, metodológicas y prácticas que operan en la epidemiología, empezando por la formación del epidemiólogo de campo. La epidemiología de campo tiende a la acción sin marco teórico. La epidemiología social, por el contrario, tiende a los desarrollos teóricos (reflexión e investigación sobre los determinantes sociales alejados de la acción, debido a los limitantes para cambiar las políticas públicas. Otras diferencias se sitúan en el nivel de intervención (micro/macroespacios, el objeto de intervención (control del brote frente a control de las desigualdades y en la forma de articular la comunicación con la sociedad. Se asemejan en la preocupación por el método, la predominancia de una orientación positivista y condicionada por la estadística, aunque en proceso de cierta apertura epistemológica, la tensión experimentada entre relacionarse con un mundo virtual de bases de datos o con la sociedad real, su situación en la periferia del sistema político-social-institucional-profesional y por estar abocadas a la frustración profesional. Finalmente, se formulan 10 interrogantes a los epidemiólogos de campo sobre su práctica actual, a través de los cuales se podría evaluar si están realizando una epidemiología social, y se sugieren cambios para introducir en la formación y práctica del epidemiólogo.Comparing field epidemiology and social epidemiology, we pretend to think about the no explicit images and meanings operating in both necessary convergent fields, about the obstacles present in epidemiological practice to fulfil its social function and about the necessity of

  2. Epidemiology of idiopathic pulmonary fibrosis

    Directory of Open Access Journals (Sweden)

    Ley B

    2013-11-01

    Full Text Available Brett Ley, Harold R Collard Department of Medicine, Division of Pulmonary and Critical Care Medicine, University of California San Francisco, San Francisco, California, USA Abstract: Idiopathic pulmonary fibrosis is a chronic fibrotic lung disease of unknown cause that occurs in adults and has a poor prognosis. Its epidemiology has been difficult to study because of its rarity and evolution in diagnostic and coding practices. Though uncommon, it is likely underappreciated both in terms of its occurrence (ie, incidence, prevalence and public health impact (ie, health care costs and resource utilization. Incidence and mortality appear to be on the rise, and prevalence is expected to increase with the aging population. Potential risk factors include occupational and environmental exposures, tobacco smoking, gastroesophageal reflux, and genetic factors. An accurate understanding of its epidemiology is important, especially as novel therapies are emerging. Keywords: idiopathic pulmonary fibrosis, epidemiology, incidence, prevalence, mortality, risk factors

  3. An epidemiological study of 500 paediatric burn patients in Mumbai, India

    Directory of Open Access Journals (Sweden)

    Verma S

    2007-01-01

    Full Text Available Aim: To study the epidemiological data of paediatric burn patients to determine the role of demographic distribution and epidemiological parameters for assessment of mortality rate and development of burn prevention strategy. Materials and Methods : Epidemiological data of 500 patients admitted to the Burns and Plastic Surgery Unit of B.J. Wadia Hospital, Mumbai over a period of six years (2000-2005 was reviewed from medical records. Age, sex, demographic distribution, seasonal variation, total body surface area (TBSA involved, type and place of burn injury, parental occupation, family size, first aid and mortality rate were studied. Result: Median age group for patient was 3.44 years (range one month to 14 years. The majority (24% of burns occurred in children between the one to two years age group. Male to female sex ratio was 1.38:1. Most of the patients were from the defined demographic region served by the hospital. A significant number of patients however were from outside this region. Burn injury occurred predominantly during winter. Most common type of burn was scalds which occurred mainly in domestic circumstances. In the majority of patients, less than 10% TBSA was involved. All patients were managed as per the unit protocol. Mortality rate was 10.4%. Mortality rate was high in patients having more than 40% TBSA involvement. Seventy-three per cent of the total deaths occurred in the patients coming from regions outside the demographic region served by the hospital. Parental occupation, family size and the first aid did not affect the mortality rate. Conclusion: Availability of a burn care unit in the vicinity can decrease the mortality rates in the paediatric burn patients. An intense and focused burn prevention campaign to educate the general population about dangerous aetiological factors will decrease the incidence of paediatric burns.

  4. Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies.

    Science.gov (United States)

    Magnuson, B A; Burdock, G A; Doull, J; Kroes, R M; Marsh, G M; Pariza, M W; Spencer, P S; Waddell, W J; Walker, R; Williams, G M

    2007-01-01

    Aspartame is a methyl ester of a dipeptide used as a synthetic nonnutritive sweetener in over 90 countries worldwide in over 6000 products. The purpose of this investigation was to review the scientific literature on the absorption and metabolism, the current consumption levels worldwide, the toxicology, and recent epidemiological studies on aspartame. Current use levels of aspartame, even by high users in special subgroups, remains well below the U.S. Food and Drug Administration and European Food Safety Authority established acceptable daily intake levels of 50 and 40 mg/kg bw/day, respectively. Consumption of large doses of aspartame in a single bolus dose will have an effect on some biochemical parameters, including plasma amino acid levels and brain neurotransmitter levels. The rise in plasma levels of phenylalanine and aspartic acid following administration of aspartame at doses less than or equal to 50 mg/kg bw do not exceed those observed postprandially. Acute, subacute and chronic toxicity studies with aspartame, and its decomposition products, conducted in mice, rats, hamsters and dogs have consistently found no adverse effect of aspartame with doses up to at least 4000 mg/kg bw/day. Critical review of all carcinogenicity studies conducted on aspartame found no credible evidence that aspartame is carcinogenic. The data from the extensive investigations into the possibility of neurotoxic effects of aspartame, in general, do not support the hypothesis that aspartame in the human diet will affect nervous system function, learning or behavior. Epidemiological studies on aspartame include several case-control studies and one well-conducted prospective epidemiological study with a large cohort, in which the consumption of aspartame was measured. The studies provide no evidence to support an association between aspartame and cancer in any tissue. The weight of existing evidence is that aspartame is safe at current levels of consumption as a nonnutritive

  5. PARAMETER ESTIMATION OF EXPONENTIAL DISTRIBUTION

    Institute of Scientific and Technical Information of China (English)

    XU Haiyan; FEI Heliang

    2005-01-01

    Because of the importance of grouped data, many scholars have been devoted to the study of this kind of data. But, few documents have been concerned with the threshold parameter. In this paper, we assume that the threshold parameter is smaller than the first observing point. Then, on the basis of the two-parameter exponential distribution, the maximum likelihood estimations of both parameters are given, the sufficient and necessary conditions for their existence and uniqueness are argued, and the asymptotic properties of the estimations are also presented, according to which approximate confidence intervals of the parameters are derived. At the same time, the estimation of the parameters is generalized, and some methods are introduced to get explicit expressions of these generalized estimations. Also, a special case where the first failure time of the units is observed is considered.

  6. [Epidemiology and maternal thrombosis].

    Science.gov (United States)

    Bosson, Jean-Luc

    2003-01-01

    The monthly incidence of deep vein thrombosis during pregnancy varies from 0.1 to 0.8 per 1000 pregnancies, depending on the study. These figures are undoubtedly an underestimation because they were determined from clinical events with no estimation of asymptomatic forms which, in general, increase the prevalence about 3-fold. Although the absolute figures are reliable, the consequences in terms of maternal mortality and post-phlebitis sequelae warrant the careful attention paid to this condition. Moreover, it should be recalled that the prevalence of superficial venous thrombosis is similar and may be associated with a risk of pulmonary embolism.

  7. Nephrogenic systemic fibrosis: epidemiology update

    DEFF Research Database (Denmark)

    Marckmann, P.

    2008-01-01

    Purpose of review The aim of this article is to outline the history of nephrogenic systemic fibrosis, a new and serious disease of patients with renal failure, and to give an update on its aetiology and prevalence. Recent findings Epidemiological and histochemical studies demonstrated that gadoli......Purpose of review The aim of this article is to outline the history of nephrogenic systemic fibrosis, a new and serious disease of patients with renal failure, and to give an update on its aetiology and prevalence. Recent findings Epidemiological and histochemical studies demonstrated...

  8. An epidemiological model of Rift Valley fever

    Directory of Open Access Journals (Sweden)

    Nicole P. Leahy

    2007-08-01

    Full Text Available We present and explore a novel mathematical model of the epidemiology of Rift Valley Fever (RVF. RVF is an Old World, mosquito-borne disease affecting both livestock and humans. The model is an ordinary differential equation model for two populations of mosquito species, those that can transmit vertically and those that cannot, and for one livestock population. We analyze the model to find the stability of the disease-free equlibrium and test which model parameters affect this stability most significantly. This model is the basis for future research into the predication of future outbreaks in the Old World and the assessment of the threat of introduction into the New World.

  9. Assessment of the risk of colorectal cancer in Poland on the basis of the analysis of epidemiological indicators

    Directory of Open Access Journals (Sweden)

    Grażyna R. Wiraszka

    2015-03-01

    Full Text Available Malignant tumours are one of the leading causes of death, as well as one of the most important health problems, in Poland and worldwide. Aim of the research was to assess the risk of colorectal cancer in a population of men and women in Poland based on the analysis of data from the most recent studies and epidemiological sources, particularly from the National Cancer Registry. In this study, epidemiological indicators of incidence and deaths for general colorectal cancer (ICD-10: C18–C21 as well as for particular cancer locations (C18 – colon, C19 – rectosigmoid junction, C20 – rectum, C21 – anus and anal canal analized in men and women in Poland in 2011 as well as the profile of these parameters in years 1999–2011. The incidence for colorectal cancer (CRC in man: structure indicators (SI – 12.4%, age standardized rates (ASR – 30.2/105; in women: SI – 10.0%, ASR – 18.0/105. The deaths due to CRC in men: SI – 11.4%, ASR – 19.8/105; in women: SI – 11.8%, ASR – 10.2/105. Colorectal cancer is a serious threat to the health of Poles, characterised by its dynamics increasing with population age, by high incidence and mortality, as well as by a persistent, constant tendency for increasing epidemiological rates, especially among men. The differentiation of epidemiological rates follows from tumour location. Higher incidence and mortality rates are registered for the population of men and among the residents of Western Poland.

  10. Gallbladder cancer: epidemiology and outcome

    Directory of Open Access Journals (Sweden)

    Hundal R

    2014-03-01

    Full Text Available Rajveer Hundal, Eldon A Shaffer Division of Gastroenterology, Department of Medicine, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada Abstract: Gallbladder cancer, though generally considered rare, is the most common malignancy of the biliary tract, accounting for 80%-95% of biliary tract cancers. An early diagnosis is essential as this malignancy progresses silently with a late diagnosis, often proving fatal. Its carcinogenesis follows a progression through a metaplasia-dysplasia-carcinoma sequence. This comprehensive review focuses on and explores the risks, management, and outcomes for primary gallbladder carcinoma. Epidemiological studies have identified striking geographic and ethnic disparities – inordinately high occurrence in American Indians, elevated in Southeast Asia, yet quite low elsewhere in the Americas and the world. Age, female sex, congenital biliary tract anomalies, and a genetic predisposition represent important risk factors that are immutable. Environmental triggers play a critical role in eliciting cancer developing in the gallbladder, best exemplified by cholelithiasis and chronic inflammation from biliary tract and parasitic infections. Mortality rates closely follow incidence; those countries with the highest prevalence of gallstones experience the greatest mortality from gallbladder cancer. Vague symptoms often delay the diagnosis of gallbladder cancer, contributing to its overall progression and poor outcome. Surgery represents the only potential for cure. Some individuals are fortunate to be incidentally found to have gallbladder cancer at the time of cholecystectomy being performed for cholelithiasis. Such an early diagnosis is imperative as a late presentation connotes advanced staging, nodal involvement, and possible recurrence following attempted resection. Overall mean survival is a mere 6 months, while 5-year survival rate is only 5%. The dismal prognosis, in part, relates to the

  11. Statistical inference to advance network models in epidemiology.

    Science.gov (United States)

    Welch, David; Bansal, Shweta; Hunter, David R

    2011-03-01

    Contact networks are playing an increasingly important role in the study of epidemiology. Most of the existing work in this area has focused on considering the effect of underlying network structure on epidemic dynamics by using tools from probability theory and computer simulation. This work has provided much insight on the role that heterogeneity in host contact patterns plays on infectious disease dynamics. Despite the important understanding afforded by the probability and simulation paradigm, this approach does not directly address important questions about the structure of contact networks such as what is the best network model for a particular mode of disease transmission, how parameter values of a given model should be estimated, or how precisely the data allow us to estimate these parameter values. We argue that these questions are best answered within a statistical framework and discuss the role of statistical inference in estimating contact networks from epidemiological data.

  12. Epigenetics: origins and implications for cancer epidemiology.

    Science.gov (United States)

    Nise, Melissa S; Falaturi, Puran; Erren, Thomas C

    2010-02-01

    This paper provides information on the evolution of the 'epigenetics' concept since Aristotle and draws attention to the importance of epigenetic implications for cancer epidemiology in the years to come. Clearly, to understand origins of the concept of epigenetics, it is worthwhile to consider historical arguments associated with evolution. Equally clearly, in the last half of the 20th century, great advances in the understanding of epigenetics and, more specifically, great advances in the understanding of epigenetics in cancer have been made. However, reaping the full benefits of epigenetics lies beyond the predominant experimental studies of today. In general, epigenetics opens many doors in the field of cancer, but it also adds another level of complex, inter-related, and multi-dimensional information to research, and to its interpretation. Overall, future cancer studies should consider, or at least be sensitive to, epigenetic effects and mechanisms. Moving the focus beyond 'pristine' inheritance via DNA alone, cancer epidemiology investigating epigenetic exposures such as environmental factors (exposure to heavy metals, air pollution, arsenic and other toxins), dietary patterns (starvation, famine, contamination), and lifestyle habits (smoking, level of physical activity, and BMI) in populations has the prospect to significantly benefit future cancer prevention and treatment schemes.

  13. Why do people participate in epidemiological research?

    Science.gov (United States)

    Slegers, Claudia; Zion, Deborah; Glass, Deborah; Kelsall, Helen; Fritschi, Lin; Brown, Ngiare; Loff, Bebe

    2015-06-01

    Many assumptions are made about public willingness to participate in epidemiological research, yet few empirical studies have been conducted to ascertain whether such assumptions are correct. Our qualitative study of the public and of expert stakeholders leads us to suggest that people are generally prepared to participate in epidemiological research, particularly if it is conducted by a trusted public institution such as a government health department, charity, or university. However, there is widespread community distrust of research conducted or sponsored by pharmaceutical companies. Individuals are prompted to take part if the study concerns an illness they or a family member or friend have personally experienced or if they believe the research will confer a widespread public benefit. Preferences vary about the mode of contact for the research to be conducted. Willingness to participate in telephone surveys has decreased in recent years, and this may be a consequence of an increase in calls to homes by telemarketers and market researchers. Participants also stressed the importance of knowing where their names and contact details were sourced and suggested that this information be available to prospective study participants as a matter of course in the first approach or letter. We provide valuable information to epidemiologists in designing studies.

  14. Evolving epidemiology of HIV-associated malignancies.

    Science.gov (United States)

    Shiels, Meredith S; Engels, Eric A

    2017-01-01

    The purpose of this review is to describe the epidemiology of cancers that occur at an elevated rate among people with HIV infection in the current treatment era, including discussion of the cause of these cancers, as well as changes in cancer incidence and burden over time. Rates of Kaposi sarcoma, non-Hodgkin lymphoma and cervical cancer have declined sharply in developed countries during the highly active antiretroviral therapy era, but remain elevated 800-fold, 10-fold and four-fold, respectively, compared with the general population. Most studies have reported significant increases in liver cancer rates and decreases in lung cancer over time. Although some studies have reported significant increases in anal cancer rates and declines in Hodgkin lymphoma rates, others have shown stable incidence. Declining mortality among HIV-infected individuals has resulted in the growth and aging of the HIV-infected population, causing an increase in the number of non-AIDS-defining cancers diagnosed each year in HIV-infected people. The epidemiology of cancer among HIV-infected people has evolved since the beginning of the HIV epidemic with particularly marked changes since the introduction of modern treatment. Public health interventions aimed at prevention and early detection of cancer among HIV-infected people are needed.

  15. Epidemiology of thymoma and associated malignancies.

    Science.gov (United States)

    Engels, Eric A

    2010-10-01

    Thymoma is a rare malignancy of unknown etiology. The author examined patterns in thymoma incidence in the US general population using data from Surveillance, Epidemiology, and End Results (SEER) cancer registries. Prior studies concerning the risk of additional malignancies in thymoma patients were reviewed. Based on cancer registry data, the overall incidence of thymoma in the US is 0.13 per 100,000 person-years. Thymoma is exceedingly uncommon in children and young adults, rises in incidence in middle age, and peaks in the seventh decade of life. Thymoma incidence is especially high among Asians and Pacific Islanders in the US. While several studies based at single treatment centers have suggested that thymoma patients have a broadly increased risk for other malignancies, follow up data from US cancer registries support a more limited spectrum of cancer risk. In particular, thymoma patients have a subsequently elevated risk for developing B-cell non-Hodgkin's lymphoma. Based on limited data, thymoma patients may also have an elevated risk for developing soft tissue sarcomas. Thymoma is a rare malignancy. The excess risk for non-Hodgkin's lymphoma is consistent with an effect of immune disturbance arising from the thymoma or its treatment. While descriptive epidemiologic data may yield clues to the etiology of thymoma, large multi-center case-control studies will be required to formally evaluate environmental and genetic risk factors.

  16. Psoriasis: epidemiology, natural history, and differential diagnosis

    Directory of Open Access Journals (Sweden)

    Basko-Plluska JL

    2012-09-01

    Full Text Available Juliana L Basko-Plluska, Vesna Petronic-RosicDepartment of Medicine, Section of Dermatology, University of Chicago, Chicago, IL, USAAbstract: Psoriasis is a chronic, immune-mediated, inflammatory disease which affects primarily the skin and joints. It occurs worldwide, but its prevalence varies considerably between different regions of the world. Genetic susceptibility as well as environmental factors play an important role in determining the development and prognosis of psoriasis. Genome-wide association studies have identified many genetic loci as potential psoriasis susceptibility regions, including PSORS1 through PSORS7. Histocompatibility antigen (HLA studies have also identified several HLA antigens, with HLA-Cw6 being the most frequently associated antigen. Epidemiological studies identified several modifiable risk factors that may predispose individuals to developing psoriasis or exacerbate pre-existing disease. These include smoking, obesity, alcohol consumption, diet, infections, medications and stressful life events. The exact mechanism by which they trigger psoriasis remains to be elucidated; however, existing data suggest that they are linked through Th1-mediated immunological pathways. The natural history of psoriasis varies depending on the clinical subtype as well as special circumstances, including pregnancy and HIV infection. In general, psoriasis is a chronic disease with intermittent remissions and exacerbations. The differential diagnosis is vast and includes many other immune-mediated, inflammatory disorders.Keywords: psoriasis, epidemiology, natural history, differential diagnosis

  17. NASA Remote Sensing Data for Epidemiological Studies

    Science.gov (United States)

    Maynard, Nancy G.; Vicente, G. A.

    2002-01-01

    In response to the need for improved observations of environmental factors to better understand the links between human health and the environment, NASA has established a new program to significantly improve the utilization of NASA's diverse array of data, information, and observations of the Earth for health applications. This initiative, lead by Goddard Space Flight Center (GSFC) has the following goals: (1) To encourage interdisciplinary research on the relationships between environmental parameters (e.g., rainfall, vegetation) and health, (2) Develop practical early warning systems, (3) Create a unique system for the exchange of Earth science and health data, (4) Provide an investigator field support system for customers and partners, (5) Facilitate a system for observation, identification, and surveillance of parameters relevant to environment and health issues. The NASA Environment and Health Program is conducting several interdisciplinary projects to examine applications of remote sensing data and information to a variety of health issues, including studies on malaria, Rift Valley Fever, St. Louis Encephalitis, Dengue Fever, Ebola, African Dust and health, meningitis, asthma, and filariasis. In addition, the NASA program is creating a user-friendly data system to help provide the public health community with easy and timely access to space-based environmental data for epidemiological studies. This NASA data system is being designed to bring land, atmosphere, water and ocean satellite data/products to users not familiar with satellite data/products, but who are knowledgeable in the Geographic Information Systems (GIS) environment. This paper discusses the most recent results of the interdisciplinary environment-health research projects and provides an analysis of the usefulness of the satellite data to epidemiological studies. In addition, there will be a summary of presently-available NASA Earth science data and a description of how it may be obtained.

  18. On Generalized Bell Polynomials

    Directory of Open Access Journals (Sweden)

    Roberto B. Corcino

    2011-01-01

    Full Text Available It is shown that the sequence of the generalized Bell polynomials Sn(x is convex under some restrictions of the parameters involved. A kind of recurrence relation for Sn(x is established, and some numbers related to the generalized Bell numbers and their properties are investigated.

  19. Parameter Estimation Through Ignorance

    CERN Document Server

    Du, Hailiang

    2015-01-01

    Dynamical modelling lies at the heart of our understanding of physical systems. Its role in science is deeper than mere operational forecasting, in that it allows us to evaluate the adequacy of the mathematical structure of our models. Despite the importance of model parameters, there is no general method of parameter estimation outside linear systems. A new relatively simple method of parameter estimation for nonlinear systems is presented, based on variations in the accuracy of probability forecasts. It is illustrated on the Logistic Map, the Henon Map and the 12-D Lorenz96 flow, and its ability to outperform linear least squares in these systems is explored at various noise levels and sampling rates. As expected, it is more effective when the forecast error distributions are non-Gaussian. The new method selects parameter values by minimizing a proper, local skill score for continuous probability forecasts as a function of the parameter values. This new approach is easier to implement in practice than alter...

  20. Epidemiology of COPD

    Directory of Open Access Journals (Sweden)

    C. Raherison

    2009-12-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is responsible for early mortality, high death rates and significant cost to health systems. The projection for 2020 indicates that COPD will be the third leading cause of death worldwide (from sixth in 1990 and fifth leading cause of years lost through early mortality or handicap (disability-adjusted life years (12th in 1990. Active smoking remains the main risk factor, but other factors are becoming better known, such as occupational factors, infections and the role of air pollution. Prevalence of COPD varies according to country, age and sex. This disease is also associated with significant comorbidities. COPD is a disorder that includes various phenotypes, the continuum of which remains under debate. The major challenge in the coming years will be to prevent onset of smoking along with early detection of the disease in the general population.

  1. Effect of Correlations Between Model Parameters and Nuisance Parameters When Model Parameters are Fit to Data

    CERN Document Server

    Roe, Byron

    2013-01-01

    The effect of correlations between model parameters and nuisance parameters is discussed, in the context of fitting model parameters to data. Modifications to the usual $\\chi^2$ method are required. Fake data studies, as used at present, will not be optimum. Problems will occur for applications of the Maltoni-Schwetz \\cite{ms} theorem. Neutrino oscillations are used as examples, but the problems discussed here are general ones, which are often not addressed.

  2. Candida infections : detection and epidemiology

    NARCIS (Netherlands)

    Borst, A. (Annemarie)

    2002-01-01

    Despite the fact that the yeast Candida is the number 4 cause of bloodstream infections in the United States and ranks number 8 in Europe, adequate detection methods are lacking. Furthermore, relatively little is known about the epidemiology of Candida. Our aim was to improve the detection and ident

  3. Brain Tumor Epidemiology Consortium (BTEC)

    Science.gov (United States)

    The Brain Tumor Epidemiology Consortium is an open scientific forum organized to foster the development of multi-center, international and inter-disciplinary collaborations that will lead to a better understanding of the etiology, outcomes, and prevention of brain tumors.

  4. Molecular epidemiology of glanders, Pakistan.

    Science.gov (United States)

    Hornstra, Heidie; Pearson, Talima; Georgia, Shalamar; Liguori, Andrew; Dale, Julia; Price, Erin; O'Neill, Matthew; Deshazer, David; Muhammad, Ghulam; Saqib, Muhammad; Naureen, Abeera; Keim, Paul

    2009-12-01

    We collected epidemiologic and molecular data from Burkholderia mallei isolates from equines in Punjab, Pakistan from 1999 through 2007. We show that recent outbreaks are genetically distinct from available whole genome sequences and that these genotypes are persistent and ubiquitous in Punjab, probably due to human-mediated movement of equines.

  5. Glossary for econometrics and epidemiology.

    Science.gov (United States)

    Gunasekara, F Imlach; Carter, K; Blakely, T

    2008-10-01

    Epidemiologists and econometricians are often interested in similar topics-socioeconomic position and health outcomes-but the different languages that epidemiologists and economists use to interpret and discuss their results can create a barrier to mutual communication. This glossary defines key terms used in econometrics and epidemiology to assist in bridging this gap.

  6. Molecular Epidemiology of Glanders, Pakistan

    OpenAIRE

    Hornstra, Heidie; Pearson, Talima; Georgia, Shalamar; Liguori, Andrew; Dale, Julia; Price, Erin; O’Neill, Matthew; DeShazer, David; Muhammad, Ghulam; Saqib, Muhammad; Naureen, Abeera; Keim, Paul

    2009-01-01

    We collected epidemiologic and molecular data from Burkholderia mallei isolates from equines in Punjab, Pakistan from 1999 through 2007. We show that recent outbreaks are genetically distinct from available whole genome sequences and that these genotypes are persistent and ubiquitous in Punjab, probably due to human-mediated movement of equines.

  7. Implementation epidemiology: The study of the frequency ...

    African Journals Online (AJOL)

    Campus, Kuala Lumpur, Malaysia .... of new epidemiological findings into policy action the American College of Epidemiology ..... The underlying contexts of seat belt wearing rates in a community relate to the economic, social, political and.

  8. Why does epidemiology need better questionnaires?

    DEFF Research Database (Denmark)

    Tong, S.; Ring, I.; Olsen, Jørn

    2003-01-01

    The authors argue for the use of validated questionnaires whenever possible to improve the quality of epidemiological research.......The authors argue for the use of validated questionnaires whenever possible to improve the quality of epidemiological research....

  9. Mitochondrial DNA and Cancer Epidemiology Workshop

    Science.gov (United States)

    A workshop to review the state-of-the science in the mitochondrial DNA field and its use in cancer epidemiology, and to develop a concept for a research initiative on mitochondrial DNA and cancer epidemiology.

  10. The evolving epidemiology of inflammatory bowel disease.

    LENUS (Irish Health Repository)

    Shanahan, Fergus

    2009-07-01

    Epidemiologic studies in inflammatory bowel disease (IBD) include assessments of disease burden and evolving patterns of disease presentation. Although it is hoped that sound epidemiologic studies provide aetiological clues, traditional risk factor-based epidemiology has provided limited insights into either Crohn\\'s disease or ulcerative colitis etiopathogenesis. In this update, we will summarize how the changing epidemiology of IBD associated with modernization can be reconciled with current concepts of disease mechanisms and will discuss studies of clinically significant comorbidity in IBD.

  11. Travel epidemiology: the Saudi perspective.

    Science.gov (United States)

    Memish, Ziad A; Venkatesh, S; Ahmed, Qanta A

    2003-02-01

    The Kingdom of Saudi Arabia occupies four-fifths of the Arabian Peninsula, with a land area of 2 million square kilometres. Saudi Arabia holds a unique position in the Islamic world, as the custodian of the two holiest places of Islam, in Mecca and Medina. Annually, some 2 million Muslims from over 140 countries embark on Hajj. This extraordinary en masse migration is a unique forum for the study of travel epidemiology since the Hajj carries various health risks, both communicable and non-communicable, often on a colossal scale. Non-communicable hazards of the Hajj include stampede and motor vehicle trauma, fire-related burn injuries and accidental hand injury during animal slaughter. Communicable hazards in the form of outbreaks of multiple infectious diseases have been reported repeatedly, during and following the Hajj. Meningococcal meningitis, gastroenteritis, hepatitis A, B and C, and various zoonotic diseases comprise some of the possible infectious hazards at the Hajj. Many of these infectious and non-infectious hazards can be avoided or averted by adopting appropriate prophylactic measures. Physicians and health personnel must be aware of these risks to appropriately educate, immunize and prepare these travellers facing the unique epidemiological challenges of Hajj in an effort to minimize untoward effects. Travel epidemiology related to the Hajj is a new and exciting area, which offers valuable insights to the travel specialist. The sheer scale of numbers affords a rare view of migration medicine in action. As data is continually gathered and both national and international policy making is tailored to vital insights gained through travel epidemiology, the Hajj will be continually safeguarded. Practitioners will gain from findings of travel related epidemiological changes in evolution at the Hajj: the impact of vaccinating policies, infection control policies and public health are afforded a real-world laboratory setting at each annual Hajj, allowing us to

  12. GENERAL INFORMATION

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    World Jour nal of Cardiolog y(World J Cardiol,WJC,online ISSN1949-8462,DOI:10.4330)is a peer-reviewed open access(OA)academic journal that aims to guide clinical practice and improve diagnostic and therapeutic skills of clinicians.Aim and scope WJC covers topics concerning arrhythmia,heart failure,vascular disease,stroke,hypertension,prevention and epidemiology,dyslipidemia and metabolic disorders,cardiac imaging,pediatrics,nursing,

  13. Generalized Lotka stability.

    Science.gov (United States)

    Smith, J D H; Zhang, C

    2015-08-01

    The recently developed macroscopic approach to demography describes the age distribution of mothers and the net maternity function for a given human population entirely in terms of five parameters. Tracking of these parameters provides a number of new tools for analyzing populations and predicting their future states. Within the macroscopic approach, the new concept of generalized Lotka stability is presented in this paper, as an extension of a strong version of classic Lotka stability. The two leading parameters of the macroscopic approach, the Malthusian parameter r and the perturbation s, are computed from population data and plotted in two-dimensional parameter space. Generalized Lotka stability is then defined in terms of the movement of the (r,s)-vector over time. It may be observed in a number of human populations at specific periods of their history.

  14. Introduction to general and generalized linear models

    CERN Document Server

    Madsen, Henrik

    2010-01-01

    IntroductionExamples of types of data Motivating examples A first view on the modelsThe Likelihood PrincipleIntroduction Point estimation theory The likelihood function The score function The information matrix Alternative parameterizations of the likelihood The maximum likelihood estimate (MLE) Distribution of the ML estimator Generalized loss-function and deviance Quadratic approximation of the log-likelihood Likelihood ratio tests Successive testing in hypothesis chains Dealing with nuisance parameters General Linear ModelsIntroduction The multivariate normal distribution General linear mod

  15. Recommendations for epidemiological studies on COPD

    DEFF Research Database (Denmark)

    Bakke, P S; Rönmark, E; Eagan, T

    2011-01-01

    The prevalence of chronic obstructive pulmonary disease (COPD) has been extensively studied, especially in Western Europe and North America. Few of these data are directly comparable because of differences between the surveys regarding composition of study populations, diagnostic criteria...... of the disease and definitions of the risk factors. Few community studies have examined phenotypes of COPD and included other ways of characterising the disease beyond that of spirometry. The objective of the present Task Force report is to present recommendations for the performance of general population...... studies in COPD in order to facilitate comparable and valid estimates on COPD prevalence by various risk factors. Diagnostic criteria in epidemiological settings, and standardised methods to examine the disease and its potential risk factors are discussed. The paper also offers practical advice...

  16. Epidemiology of hepatocellular carcinoma (HCC) in hemophilia.

    Science.gov (United States)

    Shetty, Shrimati; Sharma, Nitika; Ghosh, Kanjaksha

    2016-03-01

    Hepatocellular carcinoma (HCC) is an important cause of increasing mortality in elderly hemophilia population. Majority of the patients treated with virus non-inactivated factor concentrates prepared from large plasma pools prior to 1985 have been found to be infected with hepatitis C virus (HCV), a major risk factor for HCC. A PubMed search of articles published until February 2015 was performed utilizing the keywords hemophilia, malignancy, neoplasm, cancer, mortality, ageing hemophilia, epidemiology, hepatocellular carcinoma and liver cancer and the relevant articles were included. Contradictory reports are available in literature on the incidence of cancers in general in hemophilia population. Almost all the studies where the incidence of HCC or mortality due to HCC have been analyzed in hemophilia population show that a vast majority of these patients are HCV infected. The incidence of HCC though higher in hemophilic population is related to the higher incidence of HCV infection and not due to the hemophilia phenotype.

  17. Causation and models of disease in epidemiology.

    Science.gov (United States)

    Broadbent, Alex

    2009-12-01

    Nineteenth-century medical advances were entwined with a conceptual innovation: the idea that many cases of disease which were previously thought to have diverse causes could be explained by the action of a single kind of cause, for example a certain bacterial or parasitic infestation. The focus of modern epidemiology, however, is on chronic non-communicable diseases, which frequently do not seem to be attributable to any single causal factor. This paper is an effort to resolve the resulting tension. The paper criticises the monocausal model of disease, so successful in the nineteenth century. It also argues that a multifactorial model of disease can only be satisfactory if it amounts to more than a mere rejection of the monocausal model. A third alternative, the contrastive model, is proposed and defended on the grounds that it links the notions of disease and of general explanation, while avoiding the philosophical naiveties and practical difficulties of the monocausal model.

  18. AN EPIDEMIOLOGICAL SURVEY OF CHOLELITHIASIS IN SHANGHAI

    Institute of Scientific and Technical Information of China (English)

    叶忻; 韩天权; 王保钢; 肖志坤

    2003-01-01

    Objective To obtain a general overview of gallstone disease in Shanghai.Methods3415 citizens aged>20 in the community of Shanghai were randomly selected to undergo a clinical epidemiological study and an ultrasound examination to screen for cholelithiasis.ResultsOverall prevalence rate of gallstones was 6.5%(8.6% in women and 5.1% in men). Among the 3415 persons investigated, 65 had already undergone cholecystectomy.The percentage of asymptomatic gallstone was 70.5%. Prevalence of gallstone diseases(gallstones plus cholecystectomy) increased with age significantly.ConclusionCompared to the research in Shanghai ten years ago, especially for the persons older than 50 years, the gallstone disease has become more frequent. The proportion of asymptomatic gallstones and the awareness is increasing.

  19. An epidemiological study of histrionic personality disorder.

    Science.gov (United States)

    Nestadt, G; Romanoski, A J; Chahal, R; Merchant, A; Folstein, M F; Gruenberg, E M; McHugh, P R

    1990-05-01

    In conjunction with the Epidemiological Catchment Area (ECA) survey conducted in Baltimore, MD, a two-stage probability sample of community subjects was developed with a full psychiatric examination employing DSM-III criteria. This report details the observations on those subjects diagnosed with the DSM-III diagnosis Histrionic Personality Disorder. The results indicate that this condition can be diagnosed reliably and that it is a valid construct. It has a prevalence of 2.1% in a general population. Males and females are equally affected, suggesting that prior reports of an increased prevalence in females was an expression of ascertainment bias found in hospital-based studies. The diagnosis is associated with clear evidence of disturbance in the emotional, behavioural, and social realms. Individuals with this disorder tend to use health care facilities more frequently than others.

  20. Perfil epidemiológico general de las quejas médicas atendidas en la Comisión Nacional de Arbitraje Médico. 1996-2007 Epidemiological general profile of complaints treated at the National Medical Arbitration Commission. 1996-2007

    Directory of Open Access Journals (Sweden)

    Germán E Fajardo-Dolci

    2009-04-01

    Full Text Available OBJETIVO: Analizar las quejas médicas atendidas en un periodo de 11 años con el fin de formular recomendaciones para prevenirlas y mejorar la planeación para su atención. MATERIAL Y MÉTODOS: Se estudiaron las quejas de la Comisión Nacional de Arbitraje Médico (Conamed recibidas entre 1996 y 2007 y se utilizaron medidas de estadística descriptiva para conocer su perfil general en relación con las variables de tiempo, lugar y persona. También se determinó la frecuencia de mala práctica médica evidente, así como la gravedad del daño que producen. RESULTADOS: La solicitud de atención de quejas se incrementó entre 1996 y 2007, y existió menor demanda de atención en julio y diciembre. Dos estados del país concentran 69.7% de las quejas y 74% proviene de instituciones públicas. El 58% son de mujeres y los grupos de 25 a 34, y de 65 y más años tienen el mayor porcentaje. En 27% de las quejas atendidas hay evidencia de mala práctica médica y ginecología y obstetricia presenta el mayor porcentaje de quejas, daño físico y gravedad del daño. Las quejas por tratamiento son casi cuatro veces más que las de diagnóstico. CONCLUSIONES: Es necesario mejorar la calidad del diagnóstico y el tratamiento e identificar medidas efectivas para el costo que reduzcan la mala práctica médica y la gravedad del daño físico en los pacientes.OBJECTIVE: To analyze medical complaints over a period of 11 years, for making recommendations for prevention and improving planning for responding. MATERIAL AND METHODS: We studied the medical complaints at the National Medical Arbitration Commission (Conamed, per its acronym in Spanish between 1996 and 2007 using descriptive statistics to identify their general profile in relation to the variables of time, place and person. We also studied the frequency of evident medical malpractice as well as the severity of the damage it produces. RESULTS: The request for responses to medical complaints increased

  1. History and philosophy of modern epidemiology

    DEFF Research Database (Denmark)

    Andersen, Hanne

    2012-01-01

    Epidemiological studies of chronic diseases began around the mid-20th century. Contrary to the infectious disease epidemiology which had prevailed at the beginning of the 20th century and which had focused on single agents causing individual diseases, the chronic disease epidemiology which emerge...

  2. General Dentist

    Science.gov (United States)

    ... Some general dentists work in government health services, research programs, higher education, corporations and even the military. ?xml:namespace> What kind of procedures do general dentists provide? ?xml:namespace> Many general dentists are ...

  3. Childhood brain tumor epidemiology: a brain tumor epidemiology consortium review.

    Science.gov (United States)

    Johnson, Kimberly J; Cullen, Jennifer; Barnholtz-Sloan, Jill S; Ostrom, Quinn T; Langer, Chelsea E; Turner, Michelle C; McKean-Cowdin, Roberta; Fisher, James L; Lupo, Philip J; Partap, Sonia; Schwartzbaum, Judith A; Scheurer, Michael E

    2014-12-01

    Childhood brain tumors are the most common pediatric solid tumor and include several histologic subtypes. Although progress has been made in improving survival rates for some subtypes, understanding of risk factors for childhood brain tumors remains limited to a few genetic syndromes and ionizing radiation to the head and neck. In this report, we review descriptive and analytical epidemiology childhood brain tumor studies from the past decade and highlight priority areas for future epidemiology investigations and methodological work that is needed to advance our understanding of childhood brain tumor causes. Specifically, we summarize the results of a review of studies published since 2004 that have analyzed incidence and survival in different international regions and that have examined potential genetic, immune system, developmental and birth characteristics, and environmental risk factors. Cancer Epidemiol Biomarkers Prev; 23(12); 2716-36. ©2014 AACR.

  4. The fitting of general force-of-infection models to wildlife disease prevalence data

    Science.gov (United States)

    Heisey, D.M.; Joly, D.O.; Messier, F.

    2006-01-01

    Researchers and wildlife managers increasingly find themselves in situations where they must deal with infectious wildlife diseases such as chronic wasting disease, brucellosis, tuberculosis, and West Nile virus. Managers are often charged with designing and implementing control strategies, and researchers often seek to determine factors that influence and control the disease process. All of these activities require the ability to measure some indication of a disease's foothold in a population and evaluate factors affecting that foothold. The most common type of data available to managers and researchers is apparent prevalence data. Apparent disease prevalence, the proportion of animals in a sample that are positive for the disease, might seem like a natural measure of disease's foothold, but several properties, in particular, its dependency on age structure and the biasing effects of disease-associated mortality, make it less than ideal. In quantitative epidemiology, the a??force of infection,a?? or infection hazard, is generally the preferred parameter for measuring a disease's foothold, and it can be viewed as the most appropriate way to a??adjusta?? apparent prevalence for age structure. The typical ecology curriculum includes little exposure to quantitative epidemiological concepts such as cumulative incidence, apparent prevalence, and the force of infection. The goal of this paper is to present these basic epidemiological concepts and resulting models in an ecological context and to illustrate how they can be applied to understand and address basic epidemiological questions. We demonstrate a practical approach to solving the heretofore intractable problem of fitting general force-of-infection models to wildlife prevalence data using a generalized regression approach. We apply the procedures to Mycobacterium bovis (bovine tuberculosis) prevalence in bison (Bison bison) in Wood Buffalo National Park, Canada, and demonstrate strong age dependency in the force of

  5. Medical care epidemiology and unwarranted variation: the Israeli case.

    Science.gov (United States)

    Goodman, David C; Goodman, Andrew A

    2017-01-01

    In an article in this Journal, Mendlovic and colleagues report on regional variation in medical care across Israeli regions. This study joins a growing literature demonstrating generally high variation in the provision of health care services within developed countries. This commentary summarizes the status of medical care epidemiology and its studies of unwarranted variation in health care, and provides a conceptual framework to guide future studies. Recommendations are offered for advancing studies in Israel that could guide policy development and clinical improvement.

  6. Chapter 8. Tea and Cancer Prevention: Epidemiological Studies

    OpenAIRE

    Yuan, Jian-Min; Sun, Canlan; Butler, Lesley M

    2011-01-01

    Experimental studies have consistently shown the inhibitory activities of tea extracts on tumorigenesis in multiple model systems. Epidemiologic studies, however, have produced inconclusive results in humans. A comprehensive review was conducted to assess the current knowledge on tea consumption and risk of cancers in humans. In general, consumption of black tea was not associated with lower risk of cancer. High intake of green tea was consistently associated with reduced risk of upper gastro...

  7. Parasomnias: epidemiology and management.

    Science.gov (United States)

    Wills, Laurel; Garcia, John

    2002-01-01

    disorder can include head banging or body rocking at sleep onset or during the night. Tooth grinding is a common sleep-related behaviour that, when severe, can result in dental injury. Hypnagogic hallucinations (experience of dream imagery at sleep onset) and sleep-onset paralysis (experience of muscle/body paralysis as one is falling asleep) are symptoms rather than diagnostic categories. These phenomena classically occur in many individuals with narcolepsy, but also may occur in healthy sleep-deprived individuals. Safety precautions and good general sleep hygiene measures are recommended for individuals with a parasomnia, as the disorder can be exacerbated by sleep deprivation and various other factors. When the events are frequent or particularly dramatic, medication with a long- or medium-acting benzodiazepine, such as clonazepam, at bedtime is effective therapy in most cases of non-REM disorders of arousal and RBD. A dental guard may be helpful in tooth grinders. Relaxation training and guided imagery may be helpful strategies for some patients, especially those with disorders of arousal or rhythm movement disorders. There is no evidence of any association between parasomnias and psychiatric illness. Demystification of these conditions and reassurance, particularly for parents of paediatric patients, is an important aspect of clinical intervention.

  8. [The modern epidemiological characteristics of oto- and rhinosinusogenic intracranial complications].

    Science.gov (United States)

    Yanov, Yu K; Krivopalov, A A; Korneyenkov, A A; Shcherbuk, Yu A; Artyushkin, S A; Vakhrushev, S G; Piskunov, V S; Tuzikov, N A

    2015-01-01

    The objective of the present study was to survey epidemiology of oto- and rhinosinusogenic intracranial complications that are currently diagnosed at the territory of the Russian Federation. The work was based on the analysis of the official statistical reports together with the data obtained from the chief specialists responsible for the otorhinolaryngological services in 32 subjects of the Russian Federation during the period from 2009 to 2014. It was shown that the state of the otorhinolaryngological service in the period covered by the study was characterized by the reduction in the number of beds available for the patients presenting with ENT pathology by 14.0% and the lowering of the hospitalization rate for the general population by 6.3%. The frequency of oto- and rhinosinusogenic intracranial complications among the patients hospitalized to occupy the beds intended for the care of the patients suffering from ENT diseases was estimated at 0.03% and intrahospital lethality at 21.2%. The prevalence of pyogenic intracranial complications associated with the inflammatyory pathology affecting ENT was 0.61 per 100.000 population per year, with the mortality rate amounting to 0.17 fatal outcomes per 100.000 population per year. The study revealed significant correlation of the principal medico-statistical characteristics of high-frequency oscillatory ventilation (HFOV)---?? between themselves and with the parameters of ENT morbidity and activities of the otorhinolaryngological services at the territory of a given administrative territory. It is concluded that the improvement of the quality of healthcare for the population presenting with intracranial complications and inflammatory ENT diseases is possible only on the baseis of the combined and interdisciplinary approach to the solution of the problem.

  9. "Epidemiological criminology": coming full circle.

    Science.gov (United States)

    Akers, Timothy A; Lanier, Mark M

    2009-03-01

    Members of the public health and criminal justice disciplines often work with marginalized populations: people at high risk of drug use, health problems, incarceration, and other difficulties. As these fields increasingly overlap, distinctions between them are blurred, as numerous research reports and funding trends document. However, explicit theoretical and methodological linkages between the 2 disciplines remain rare. A new paradigm that links methods and statistical models of public health with those of their criminal justice counterparts is needed, as are increased linkages between epidemiological analogies, theories, and models and the corresponding tools of criminology. We outline disciplinary commonalities and distinctions, present policy examples that integrate similarities, and propose "epidemiological criminology" as a bridging framework.

  10. Epidemiology of cancer in Malaysia.

    Science.gov (United States)

    Lo, E K

    1985-12-01

    Some information on cancer in Malaysia are available, and its epidemiology is described. There is a need for systematic and coordinated collection of cancer statistics which are essential to patient management, cancer control programme formulation, implementation and evaluation. The decision of the Ministry of Health to introduce National Cancer Registry and to encourage epidemiological studies, which will ultimately lead to the utilization of data and introduction of control and preventive activities for cancers are positive steps in the right direction. Meanwhile, curative and palliative treatment is available from the existing hospital facilities, and preventive activities such as actions on smoking and health will be continued until such time when a comprehensive prevention and control programme for cancers in the country is evolved.

  11. [Epidemiology of burns in France].

    Science.gov (United States)

    Latarjet, Jacques; Ravat, François

    2012-01-01

    As with most traumas, the epidemiology of the "burn" health-event has long been neglected by public health doctors and rarely considered by burns specialists. There were therefore few verified data and many approximations and preconceived ideas. The gathering of information recently undertaken in France enables the reliability of the data to be improved and the diagnostic and demographic elements relating to hospitalised patients with burns to be established.

  12. Current Epidemiology of Genitourinary Trauma

    Science.gov (United States)

    McGeady, James B.; Breyer, Benjamin N.

    2013-01-01

    Synopsis This article reviews recent publications evaluating the current epidemiology of urologic trauma. It begins by providing a brief explanation of databases that have been recently used to study this patient population, then proceeds to discuss each genitourinary organ individually, discussing the most relevant and up to date information published for each one. The conclusion of the article briefly discusses possible future research and development areas pertaining to the topic. PMID:23905930

  13. Epidemiological characteristics of gastric cancer

    OpenAIRE

    Šipetić Sandra B.; Tomić-Kundaković Slađana; Vlajinac Hristina D.; Maksimović Nataša; Knežević Anita; Kisić Darija

    2005-01-01

    Introduction. Gastric cancer was the third most common cancer worldwide in 2000, accounting for approximately 876 000 new cases or 9% of the global cancer burden. Epidemiological characteristics As a result of changes in diet, the incidence of gastric cancer has decreased in most countries. Now days, consumption of fresh vegetables and fruits is increasing in regard to canned food. In addition to unhealthy diet, the main risk factors for gastric cancer are H. pylori infection, alcohol consump...

  14. A Generalized Information Criterion for Parameters under an Umbrella Order Restriction%伞形序约束下参数的一个广义信息准则

    Institute of Scientific and Technical Information of China (English)

    宋海燕; 陶剑

    2005-01-01

    @@ The detection of the configuration of parameters is one of the most important problems in statistical studies. It is well known that the Akaike's information criterion (AIC) is a key tool for this problem (see [1]). Usually, the AIC is defined as: AIC(^,μ) := l(^,μ) -p,where l(^,μ) is the log-likelihood with the maximum likelihood estimator (MLE) (^,μ) for μ,and p is the dimension of μ.

  15. [Epidemiological dynamics of Dengue on Easter Island].

    Science.gov (United States)

    Canals, Mauricio; González, Christian; Canals, Andrea; Figueroa, Daniela

    2012-08-01

    Dengue is considered an emerging disease with an increasing prevalence especially in South America. In 2002, an epidemic of classic Dengue (DENV-1) occurred unexpectedly on Easter Island, where it had never been detected before. It reappeared in 2006-2007 and 2008, 2009 and 2011. The aim of this study was to estimate the most relevant parameters of the epidemiological dynamics of transmission of Dengue on Easter Island and to model the dynamics since 2002, comparing the predictions with the actual situation observed. Of the total cases, 52.27% were females and 47.73% men. The average age of infection was 31.38 ± 18.37 years, similar in men and women. We estimated the reproductive number R0 = 3.005 with an IC0,95 = [1.92, 4.61]. The inter-epidemic period reached an estimated T = 5.20 to 6.8 years. The case simulation showed recurrent epidemics with decreasing magnitude (damped oscillations), which is a known phenomenon in models of dengue and malaria. There was good qualitative fit to the epidemiological dynamics from 2002 onwards. It accurately predicted the rise in cases between 2006 and 2011. The predicted number of cases during the 2002 epidemic is greater than the confirmed cases and the predicted epidemic was faster than notified cases. Interepidemic period in the simulation was 6.72 years between 2002 and 2008 and 4.68 years between 2008 and 2013. From the theoretical perspective, the first epidemic had affected 94% of the population (approximately 3500 cases), but 639 were reported suggesting underreporting and a lot of sub-clinical cases occurred. Future epidemic of decreasing size are expected, although the main danger are epidemics of hemorrhagic dengue fever resulting from the introduction of different dengue virus serotypes.

  16. [Epidemiological research on environmental health risks and their economic consequences].

    Science.gov (United States)

    Haucke, F; Holle, R; Wichmann, H E

    2009-12-01

    In environmental health research, methods for quantitative analysis of human population studies data are gaining importance. In recent years, it has been realized that they can also provide an important link to the economic view on environmental health effects. In this review, fundamental concepts and methods from environmental epidemiology and health economics are presented and it is shown how they can be linked in order to support environmental policy decisions. In addition, the characteristics of environmental epidemiology and the role of epidemiologic studies in risk assessment are discussed. From the economic point of view, cost-of-illness studies and cost effectiveness studies are the main approaches, and we have placed special focus on methods of monetary valuation of health effects that are generally proposed in the environmental context. Two conceptually differing strategies to combine epidemiologic and economic evidence are presented: the environmental attributable fraction model as a top-down approach and the impact pathway approach which follows a bottom-up analysis strategy. Finally, two examples are used to illustrate the application of these concepts and methods: health risks caused by fine particle air pollution and their costs, and the cost-effectiveness of radon exposure reduction policies.

  17. Stories From the Evolution of Guidelines for Causal Inference in Epidemiologic Associations: 1953–1965

    OpenAIRE

    Blackburn, Henry; Labarthe, Darwin

    2012-01-01

    Guidelines for causal inference in epidemiologic associations were a major contribution to modern epidemiologic analysis in the 1960s. This story recounts dramatic elements in a series of exchanges leading to their formulation and effective use in the 1964 Report of the Advisory Committee to the US Surgeon General on Smoking and Health, the landmark report which concluded that cigarette smoking caused lung cancer. The opening salvo was precipitated by Ancel Keys' presentation of an ecologic c...

  18. Genetic epidemiology of familial aggregation of cancer.

    Science.gov (United States)

    Schneider, N R; Williams, W R; Chaganti, R S

    1986-01-01

    Literature pertaining to genetic epidemiological studies of familial cancer has been reviewed from a historical perspective. Although interest in the question of heritability of cancer was extant at least as early as the beginning of the nineteenth century, early investigators were unable to produce consistent and meaningful evidence pertaining to the issue because of unsystematic methods of data collection and inadequate methods of data analysis. During the early twentieth century, developments in the fields of genetics, statistics, and epidemiology provided concepts and methods that permitted investigators to recognize important deficiencies in past studies, and to design others in which the critical comparisons could be made between patient groups and control groups. Registries of cancer incidence in large populations became available in several countries in the middle twentieth century, providing a standard "control group" for comparison. Large surveys of site-specific cancer experience in families, rigorously designed and analyzed, found for most kinds of cancers a two- to threefold increased risk for close relatives of propositi. These studies also reemphasized the great difficulty in obtaining even minimally complete family health history information, and the importance of verifying all reported cases with medical or vital records. Although clinical and laboratory investigation will be necessary to understand the mechanisms by which human genes may predispose to cancer, epidemiological approaches can estimate the extent to which genetic etiological factors may be present in a population, whether a general population or one defined by other factors under investigation. Population-based studies are already of practical significance to the clinical geneticist in the estimation of risk of eventual cancer development in unaffected family members, and can be expected to continue to identify specific groups and characteristics associated with genetic cancer

  19. Generalized Lindley Distribution

    Directory of Open Access Journals (Sweden)

    H. Zakerzadeh

    2009-06-01

    Full Text Available In this paper, we introduce a three–parameter generalization of the Lindley distribution. This includes as special cases the exponential and gamma distributions. The distribution exhibits decreasing, increasing and bathtub hazard rate depending on its parameters. We study various properties of the new distribution and provide numerical examples to show the flexibility of the model. We also derive a bivariate version of the proposed distribution.

  20. Respiratory effects of environmental pollution: epidemiological data.

    Science.gov (United States)

    Baldacci, S; Viegi, G

    2002-01-01

    A recent document of the American Thoracic Society and two previous reports of the International Union Against Tuberculosis and Lung Disease have summarized the negative health effects due to air pollution in a list ranging from the increase of mortality to the perception of bad odors. A significant attempt to estimate, on an annual basis, the negative effects of air pollution from particulate matter less than 10 microns in aerodynamic diameter (PM10) has been carried out on data from Austria, France, and Switzerland: e.g. in France, air pollution from PM10 is responsible annually for 31,700 deaths, 36,700 new cases of chronic bronchitis and 577,000 attacks of asthma in adults, 450,000 cases of acute bronchitis and 243,000 attacks of asthma in children. Recently, a study on the long-term effects of air pollution on about 500,000 residents in metropolitan US areas evidenced that each 10 micrograms/m3 elevation in fine particulate air pollution is associated with approximately a 4%, 6% and 8% increased risk of all-cause, cardiopulmonary and lung cancer mortality, respectively. Some Italian experiences have also confirmed respiratory health damages from air pollution, namely the prospective epidemiologic studies on general population samples of the Po Delta and Pisa areas; the cross-sectional study on schoolchildren of the 'Italian study on respiratory disorders in childhood and environment' (SIDRIA); and a meta-analysis of the Italian studies on short-term effects of air pollution. In conclusion, epidemiologic studies suggest that air pollution plays an important role in the exacerbation and in the pathogenesis of chronic respiratory diseases. Thus, respiratory physicians, as well as public health professionals, should advocate for a cleaner environment.

  1. Epidemiology and etiology of denture stomatitis.

    Science.gov (United States)

    Gendreau, Linda; Loewy, Zvi G

    2011-06-01

    Denture stomatitis, a common disorder affecting denture wearers, is characterized as inflammation and erythema of the oral mucosal areas covered by the denture. Despite its commonality, the etiology of denture stomatitis is not completely understood. A search of the literature was conducted in the PubMed electronic database (through November 2009) to identify relevant articles for inclusion in a review updating information on the epidemiology and etiology of denture stomatitis and the potential role of denture materials in this disorder. Epidemiological studies report prevalence of denture stomatitis among denture wearers to range from 15% to over 70%. Studies have been conducted among various population samples, and this appears to influence prevalence rates. In general, where reported, incidence of denture stomatitis is higher among elderly denture users and among women. Etiological factors include poor denture hygiene, continual and nighttime wearing of removable dentures, accumulation of denture plaque, and bacterial and yeast contamination of denture surface. In addition, poor-fitting dentures can increase mucosal trauma. All of these factors appear to increase the ability of Candida albicans to colonize both the denture and oral mucosal surfaces, where it acts as an opportunistic pathogen. Antifungal treatment can eradicate C. albicans contamination and relieve stomatitis symptoms, but unless dentures are decontaminated and their cleanliness maintained, stomatitis will recur when antifungal therapy is discontinued. New developments related to denture materials are focusing on means to reduce development of adherent biofilms. These may have value in reducing bacterial and yeast colonization, and could lead to reductions in denture stomatitis with appropriate denture hygiene.

  2. [Teratology and epidemiology in the study of environmental teratogens].

    Science.gov (United States)

    Cayré, R; Sánchez-Gómez, C; Moreno-Rodríguez, R A; de la Cruz, M V

    1992-07-01

    The processes of cellular migration, cellular differentiation and cellular multiplication are studied, since these are the basic developmental processes upon which teratogenic agents act resulting in congenital malformations. We also carefully analyze the interactions between teratogen-embryo in order to establish adequate parameters for analysis of environmental teratogens, as well as experimental teratogenesis and epidemiology. Information on the pathogenesis of congenital malformations obtained from experimental teratology in an adequate biological model, can be extrapolated to the human. The etiology of congenital malformations resulting from environmental teratogens can only be elucidated through epidemiology, since there is species specificity. Such a study must fulfill the following prerequisites: diagnosis of the congenital malformation, ruling out genetic factors in the family tree and determination of the exact time of exposure to the possible teratogen during the pregnancy.

  3. Epidemiology.

    Science.gov (United States)

    Walsh, Kyle M; Ohgaki, Hiroko; Wrensch, Margaret R

    2016-01-01

    More than 250,000 new cases of primary malignant brain tumors are diagnosed annually worldwide, 77% of which are gliomas. A small proportion of gliomas are caused by the inheritance of rare high-penetrance genetic variants or high-dose radiation. Since 2009, inherited genetic variants in 10 regions near eight different genes have been consistently associated with glioma risk via genome-wide association studies. Most of these variants increase glioma risk by 20-40%, but two have higher relative risks. One on chromosome 8 increases risk of IDH-mutated gliomas sixfold and another that affects TP53 function confers a 2.5-fold increased risk of glioma. Functions of some of the other risk variants are known or suspected, but future research will determine functions of other risk loci. Recent progress also has been made in defining subgroups of glioma based on acquired alterations within tumors. Allergy history has been consistently associated with reduced glioma risk, though the mechanisms have not yet been clarified. Future studies will need to be large enough so that environmental and constitutive genetic risk factors can be examined within molecularly defined, etiologically homogeneous subgroups.

  4. Epidemiology and Diagnosis of Hypoparathyroidism.

    Science.gov (United States)

    Clarke, Bart L; Brown, Edward M; Collins, Michael T; Jüppner, Harald; Lakatos, Peter; Levine, Michael A; Mannstadt, Michael M; Bilezikian, John P; Romanischen, Anatoly F; Thakker, Rajesh V

    2016-06-01

    Hypoparathyroidism is a disorder characterized by hypocalcemia due to insufficient secretion of PTH. Pseudohypoparathyroidism is a less common disorder due to target organ resistance to PTH. This report summarizes the results of the findings and recommendations of the Working Group on Epidemiology and Diagnosis of Hypoparathyroidism. Each contributing author reviewed the recent published literature regarding epidemiology and diagnosis of hypoparathyroidism using PubMed and other medical literature search engines. The prevalence of hypoparathyroidism is an estimated 37 per 100 000 person-years in the United States and 22 per 100 000 person-years in Denmark. The incidence in Denmark is approximately 0.8 per 100 000 person-years. Estimates of prevalence and incidence of hypoparathyroidism are currently lacking in most other countries. Hypoparathyroidism increases the risk of renal insufficiency, kidney stones, posterior subcapsular cataracts, and intracerebral calcifications, but it does not appear to increase overall mortality, cardiovascular disease, fractures, or malignancy. The diagnosis depends upon accurate measurement of PTH by second- and third-generation assays. The most common etiology is postsurgical hypoparathyroidism, followed by autoimmune disorders and rarely genetic disorders. Even more rare are etiologies including parathyroid gland infiltration, external radiation treatment, and radioactive iodine therapy for thyroid disease. Differentiation between these different etiologies is aided by the clinical presentation, serum biochemistries, and in some cases, genetic testing. Hypoparathyroidism is often associated with complications and comorbidities. It is important for endocrinologists and other physicians who care for these patients to be aware of recent advances in the epidemiology, diagnosis, and genetics of this disorder.

  5. Perfil clínico, epidemiológico e etiológico de pacientes com pneumonia adquirida na comunidade internados em um hospital geral da microrregião de Sumaré, SP Clinical, epidemiological, and etiological profile of inpatients with community-acquired pneumonia at a general hospital in the Sumaré microregion of Brazil

    Directory of Open Access Journals (Sweden)

    Maria Rita Donalisio

    2011-04-01

    Full Text Available OBJETIVO: Analisar aspectos clínicos, etiológicos e epidemiológicos das pneumonias adquiridas na comunidade (PAC em indivíduos internados. MÉTODOS: Foram estudados prospectivamente 66 pacientes com PAC maiores de 14 anos no Hospital Estadual Sumaré, localizado na cidade de Sumaré (SP, entre outubro de 2005 e setembro de 2007. Coletamos dados sobre história clínica, exame clínico, escore pneumonia severity index (PSI e exames laboratoriais (hemocultura, bacterioscopia/cultura de escarro, sorologias para Chlamydophila pneumoniae, Mycoplasma pneumoniae e Legionella pneumophila, além de antígenos urinários de Legionella sp. e Streptococcus pneumoniae. RESULTADOS: A idade média dos pacientes foi de 53 anos, a maioria tinha baixa escolaridade, e 55,7% apresentavam pelo menos uma comorbidade no momento da internação. O percentual de idosos vacinados contra influenza entre os internados foi significativamente menor que os da comunidade dos municípios da microrregião de Sumaré (52,6% vs. > 70%. A febre foi menos frequente entre os idosos (p OBJECTIVE: To analyze the clinical, etiological, and epidemiological aspects of community-acquired pneumonia (CAP in hospitalized individuals. METHODS: We prospectively studied 66 patients (> 14 years of age with CAP admitted to the Hospital Estadual Sumaré, located in the Sumaré microregion of Brazil, between October of 2005 and September of 2007. We collected data related to clinical history, physical examination, pneumonia severity index (PSI scores, and laboratory tests (blood culture; sputum smear microscopy and culture; serology for Chlamydophila pneumoniae, Mycoplasma pneumoniae, and Legionella pneumophila; and detection of Legionella sp. and Streptococcus pneumoniae antigens in urine. RESULTS: The mean age of patients was 53 years. Most had a low level of education, and 55.7% presented with at least one comorbidity at the time of hospitalization. The proportion of elderly people vaccinated

  6. Epidemiology of Ciguatera in Florida

    OpenAIRE

    Radke, Elizabeth G.; Reich, Andrew; Morris, John Glenn

    2015-01-01

    Ciguatera is the most commonly reported marine food-borne illness worldwide. Because there is a biological plausibility that ciguatera may be impacted by long-term climate variability and Florida is on the northern border of the geographic distribution of ciguatera, it is important to update our understanding of its epidemiology in Florida. We performed an analysis of 291 reports in Florida from 2000 to 2011 and an e-mail survey of 5,352 recreational fishers to estimate incidence and underrep...

  7. An introduction to mathematical epidemiology

    CERN Document Server

    Martcheva, Maia

    2015-01-01

    The book is a comprehensive, self-contained introduction to the mathematical modeling and analysis of infectious diseases. It includes model building, fitting to data, local and global analysis techniques. Various types of deterministic dynamical models are considered: ordinary differential equation models, delay-differential equation models, difference equation models, age-structured PDE models and diffusion models. It includes various techniques for the computation of the basic reproduction number as well as approaches to the epidemiological interpretation of the reproduction number. MATLAB code is included to facilitate the data fitting and the simulation with age-structured models.

  8. Intrathoracic neoplasia: Epidemiology and etiology

    Energy Technology Data Exchange (ETDEWEB)

    Weller, R.E.

    1992-05-01

    Neoplasms of the thorax encompass those derived from the thoracic wall, trachea, mediastinum, lungs and pleura. They represent a wide variety of lesions including benign and malignant tumors arising from many tissues. The large surface area, 60 to 90 m{sup 2} in man, represented by the respiratory epithelium and associated thoracic structures are ideal targets for carcinogens carried by inspired air. The topic of discussion in this report is the epidemiology, etiology, and mechanisms of spontaneous intrathoracic neoplasia in animals and man. Much of what we know or suspect about thoracic neoplasia in animals has been extrapolated from experimentally-induced neoplasms.

  9. Epidemiological investigation of esophageal carcinoma

    Institute of Scientific and Technical Information of China (English)

    Hong Zhang; Shao-Hua Chen; You-Ming Li

    2004-01-01

    AIM: To review the characteristics of esophageal carcinoma in recent 30 years in the epidemiological investigation.METHODS: A total of 1 520 cases of esophageal carcinoma in the First Affiliated Hospital of Zhejiang University Medical College admitted from 1970 until now were reviewed. Their age, gender, position of carcinoma and histological type were analyzed.RESULTS: The morbidity of esophageal carcinoma was increasing during the observation period. Compared with the 1970s (9.5%), the ratio of adenocarcinoma significantly increased after the 1980s (19.1%). The difference was significant (P≤0.05).CONCLUSION: The morbidity of esophageal adenocarcinoma was increasing and advanced clinical study should be strengthened.

  10. Integrative cancer epidemiology--the next generation.

    Science.gov (United States)

    Spitz, Margaret R; Caporaso, Neil E; Sellers, Thomas A

    2012-12-01

    We outline an integrative approach to extend the boundaries of molecular cancer epidemiology by integrating modern and rapidly evolving "omics" technologies into state-of-the-art molecular epidemiology. In this way, one can comprehensively explore the mechanistic underpinnings of epidemiologic observations in cancer risk and outcome. We highlight the exciting opportunities to collaborate across large observational studies and to forge new interdisciplinary collaborative ventures.

  11. Genetic epidemiological study of schizophrenia: reproduction behaviour.

    Science.gov (United States)

    Ritsner, M; Sherina, O; Ginath, Y

    1992-06-01

    Data from the Tomsk Epidemiological Register and epidemiological family sample were used to study the relationship between schizophrenics' reproductive behaviour (marital status and fertility rate), severity of ICD-9 schizophrenia and risk of illness among relatives of probands. The results are interpreted in terms of multifactorial threshold and single monolocus models. Their importance for the interpretation of epidemiological data (a change of prevalence rate, cohort effect and clinical polymorphism) is discussed.

  12. Integrative Cancer Epidemiology - The Next Generation

    Science.gov (United States)

    Spitz, Margaret R.; Caporaso, Neil E.; Sellers, Thomas A.

    2012-01-01

    Summary We outline an integrative approach to extend the boundaries of molecular cancer epidemiology by integrating modern and rapidly evolving “omics” technologies into state-of-the-art molecular epidemiology. In this way, one can comprehensively explore the mechanistic underpinnings of epidemiologic observations into cancer risk and outcome. We highlight the exciting opportunities to collaborate across large observational studies and to forge new interdisciplinary collaborative ventures. PMID:23230187

  13. COPD in Taiwan: a National Epidemiology Survey

    Directory of Open Access Journals (Sweden)

    Cheng SL

    2015-11-01

    Full Text Available Shih-Lung Cheng,1,2 Ming-Cheng Chan,3 Chin-Chou Wang,4 Ching-Hsiung Lin,5 Hao-Chien Wang,6 Jeng-Yuan Hsu,3 Liang-Wen Hang,7,8 Chee-Jen Chang,9 Diahn-Warng Perng,10,* Chong-Jen Yu6,* On behalf of the Taiwan COPD Consortium 1Department of Internal Medicine, Far Eastern Memorial Hospital, New Taipei City, 2Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li City, Taoyuan County, 3Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, 4Division of Pulmonary and Critical Care Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, 5Division of Chest Medicine, Changhua Christian Hospital, Changhua City, Changhua County, 6Department of Internal Medicine, National Taiwan University Hospital, Taipei, 7Department of Pulmonary and Critical Care Medicine, Sleep Medicine Center, China Medical University Hospital, 8Department of Respiratory Therapy, College of Health Care, China Medical University, Taichung, 9Biostatistical Center for Clinical Research, Chang Gung Memorial Hospital, Linkou Branch, Guishan Township, Taoyuan County, 10Department of Chest Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, Republic of China *These authors contributed equally to this work Objectives: To determine the prevalence of COPD in Taiwan and to document the disease characteristics and associated risk factors.Methods: We conducted a random cross-sectional national survey of adults older than 40 years in Taiwan. Respiratory health screening questions identified subjects with diagnosed COPD or whose reported symptoms also fulfilled an epidemiological case definition; these were eligible to complete the survey, which also included indices of symptom severity and disability and questions on comorbidities, medical treatments, smoking habits, and occupations potentially harmful to respiratory health. Subjects with diagnosed COPD were subdivided by smoking status. Subjects who fulfilled the case definition

  14. Maximum Likelihood Estimates of Parameters in Various Types of Distribution Fitted to Important Data Cases.

    OpenAIRE

    Hirose, Hideo

    1998-01-01

    TYPES OF THE DISTRIBUTION:13;Normal distribution (2-parameter)13;Uniform distribution (2-parameter)13;Exponential distribution ( 2-parameter)13;Weibull distribution (2-parameter)13;Gumbel Distribution (2-parameter)13;Weibull/Frechet Distribution (3-parameter)13;Generalized extreme-value distribution (3-parameter)13;Gamma distribution (3-parameter)13;Extended Gamma distribution (3-parameter)13;Log-normal distribution (3-parameter)13;Extended Log-normal distribution (3-parameter)13;Generalized ...

  15. Maximum Likelihood Estimates of Parameters in Various Types of Distribution Fitted to Important Data Cases.

    OpenAIRE

    Hirose, Hideo

    1998-01-01

    TYPES OF THE DISTRIBUTION:13;Normal distribution (2-parameter)13;Uniform distribution (2-parameter)13;Exponential distribution ( 2-parameter)13;Weibull distribution (2-parameter)13;Gumbel Distribution (2-parameter)13;Weibull/Frechet Distribution (3-parameter)13;Generalized extreme-value distribution (3-parameter)13;Gamma distribution (3-parameter)13;Extended Gamma distribution (3-parameter)13;Log-normal distribution (3-parameter)13;Extended Log-normal distribution (3-parameter)13;Generalized ...

  16. Genetics and epidemiology, congenital anomalies and cancer

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, J.M. [Univ. of British Columbia, Vancouver (Canada)

    1997-03-01

    Many of the basic statistical methods used in epidemiology - regression, analysis of variance, and estimation of relative risk, for example - originally were developed for the genetic analysis of biometric data. The familiarity that many geneticists have with this methodology has helped geneticists to understand and accept genetic epidemiology as a scientific discipline. It worth noting, however, that most of the work in genetic epidemiology during the past decade has been devoted to linkage and other family studies, rather than to population-based investigations of the type that characterize much of mainstream epidemiology. 30 refs., 2 tabs.

  17. Epidemiological studies of esophageal cancer in the era of genome-wide association studies

    Institute of Scientific and Technical Information of China (English)

    An-Hui; Wang; Yuan; Liu; Bo; Wang; Yi-Xuan; He; Ye-Xian; Fang; Yong-Ping; Yan

    2014-01-01

    Esophageal cancer(EC) caused about 395000 deaths in 2010. China has the most cases of EC and EC is the fourth leading cause of cancer death in China. Esophageal squamous cell carcinoma(ESCC) is the predominant histologic type(90%-95%), while the incidence of esophageal adenocarcinoma(EAC) remains extremely low in China. Traditional epidemiological studies have revealed that environmental carcinogens are risk factors for EC. Molecular epidemiological studies revealed that susceptibility to EC is influenced by both environmental and genetic risk factors. Of all the risk factors for EC, some are associated with the risk of ESCC and others with the risk of EAC. However, the details and mechanisms of risk factors involved in the process for EC are unclear. The advanced methods and techniques used in human genome studies bring a great opportunity for researchers to explore and identify the details of those risk factors or susceptibility genes involved inthe process of EC. Human genome epidemiology is a new branch of epidemiology, which leads the epidemiology study from the molecular epidemiology era to the era of genome wide association studies(GWAS). Here we review the epidemiological studies of EC(especially ESCC) in the era of GWAS, and provide an overview of the general risk factors and those genomic variants(genes, SNPs, miRNAs, proteins) involved in the process of ESCC.

  18. Epidemiologic aspects of neural tube defects in the United States: changing concepts and their importance for screening and prenatal diagnostic programs

    Energy Technology Data Exchange (ETDEWEB)

    Sever, L.E.; Strassburg, M.A.

    1983-09-01

    This report considers several major epidemiologic aspects of neural tube defects (NTDs). After examining briefly the approaches and goals of epidemiology the traditional epidemiologic concepts of NTDs are reviewed and new interpretations of the epidemiology of these defects is suggested. Three major topics are addressed: (1) that much of our knowledge of the epidemiology of the NTDs comes from areas or periods of high rates of occurrence and that generalizations based on these data may not be applicable to low incidence situations; (2) that the etiology of these defects is multifactorial, involving interaction between genetic and nongenetic factors which may differ in their relative importance between populations; and (3) that anencephalus and spina bifida may be more epidemiologically and etiologically distinct than is usually appreciated. A final consideration deals with some recent contributions of epidemiology to screening and prenatal diagnosis programs.

  19. Preliminary results on epidemiology of Coconut Lethal Yellowing in Ghana

    Directory of Open Access Journals (Sweden)

    Bonnot François

    2009-03-01

    Full Text Available Epidemiological studies are of major importance in understanding the determinants of plant diseases in order to control the risks of their spreading. A research programme on the epidemiology of coconut lethal yellowing, or Cape Saint Paul Wilt Disease (CSPWD, in Ghana was launched in March 2007. The objective was to characterize the distribution and spread of the disease in space and time at various scales, and their relation with the environment. This article presents the general strategy used to evaluate the incidence of CSPWD along with the environmental, ecological and agronomical variables at regional level. A survey was undertaken on 1,166 plots of Coconut Sector Development Project (CSDP planted with Malayan Yellow Dwarf (MYD × Vanuatu Tall (VTT hybrids in Western Region and Central Region. Preliminary results on the distribution of CSPWD and outside variables at regional scale, along with their relations, are given.

  20. Systems Epidemiology: What’s in a Name?

    Science.gov (United States)

    Dammann, O.; Gray, P.; Gressens, P.; Wolkenhauer, O.; Leviton, A.

    2014-01-01

    Systems biology is an interdisciplinary effort to integrate molecular, cellular, tissue, organ, and organism levels of function into computational models that facilitate the identification of general principles. Systems medicine adds a disease focus. Systems epidemiology adds yet another level consisting of antecedents that might contribute to the disease process in populations. In etiologic and prevention research, systems-type thinking about multiple levels of causation will allow epidemiologists to identify contributors to disease at multiple levels as well as their interactions. In public health, systems epidemiology will contribute to the improvement of syndromic surveillance methods. We encourage the creation of computational simulation models that integrate information about disease etiology, pathogenetic data, and the expertise of investigators from different disciplines. PMID:25598870

  1. Metabolomic Approaches in Cancer Epidemiology

    Directory of Open Access Journals (Sweden)

    Mukesh Verma

    2015-08-01

    Full Text Available Metabolomics is the study of low molecular weight molecules or metabolites produced within cells and biological systems. It involves technologies such as mass spectrometry (MS and nuclear magnetic resonance spectroscopy (NMR that can measure hundreds of thousands of unique chemical entities (UCEs. The metabolome provides one of the most accurate reflections of cellular activity at the functional level and can be leveraged to discern mechanistic information during normal and disease states. The advantages of metabolomics over other “omics” include its high sensitivity and ability to enable the analysis of relatively few metabolites compared with the number of genes and messenger RNAs (mRNAs. In clinical samples, metabolites are more stable than proteins or RNA. In fact, metabolomic profiling in basic, epidemiologic, clinical, and translational studies has revealed potential new biomarkers of disease and therapeutic outcome and has led to a novel mechanistic understanding of pathogenesis. These potential biomarkers include novel metabolites associated with cancer initiation, regression, and recurrence. Unlike genomics or even proteomics, however, the degree of metabolite complexity and heterogeneity within biological systems presents unique challenges that require specialized skills and resources to overcome. This article discusses epidemiologic studies of altered metabolite profiles in several cancers as well as challenges in the field and potential approaches to overcoming them.

  2. Epidemiology of tibial shaft fractures

    Directory of Open Access Journals (Sweden)

    Grecco Marco Aurélio Sertório

    2002-01-01

    Full Text Available In this work an epidemiological analysis on tibial shaft fractures was performed. During four years, our service treated 179 fractures, 132 in male, 47 in female, aged 14 to 83 years. The 21 to 30-year-old patiens were the more injured. Of these, 120 were open and 59 close fractures of which prevailing cause was road traffic accident. The study based on patients promptuaries analyses and radiographs. The fractures occurred 97 times in the middle third (54.18%; 102 times (56.98% presented simple fragments, and 57 (31.38% oblique lines. We treated close and open fractures, respectively, 48 and 38 cases with plaster cast immobilization; 3 and 67 with external fixation after plaster cast immobilization; 5 and 12 with osteosynthesis by means of plate and screws, and 2 and 3 with external fixation only. In both close and open fractures, respectively, 7 and 20 cases of pseudarthrosis and 1 and 11 of infections have occurred. With the data obtained we verified an actual validity of the epidemiological studies as a contribution for better identifying lesions features and their treatment and complications. This allows proceedings and apprenticeship refinement.

  3. [Epidemiology of acromegaly in Spain].

    Science.gov (United States)

    Sesmilo, Gemma

    2013-10-01

    Epidemiology of acromegaly in Spain does not differ from that reported in other published series. Prevalence rate is approximately 60 cases per million, peak incidence occurs in middle age, more women are affected (61%), and there is a substantial delay between occurrence of the first symptoms and diagnosis. Studies REA (Spanish Acromegaly Registry) and OASIS analyzed the epidemiology, clinical characteristics, and management of the disease in Spain. Surgery, performed in more than 80% of patients, has been (and continues to be) the main treatment for the past four decades. In the past decade, however, more patients have received somatostatin analogs (SSAs) as first-line treatment. Use of radiation therapy has significantly decreased in recent decades. Somatostatin analogs (SSAs) are the most commonly used drugs, administered to 85% of patients; however, only 12%-15% continue on drug treatment alone. The surgical remission rate was 38.4% in the last decade, with a significant improvement over decades. Preoperative treatment with SSAs has no influence on surgical cure rates. Second-line therapies used after surgical failure in the past decade included SSAs in 49% of patients, repeat surgery in 27%, radiotherapy in 11%, pegvisomant in 15%, and dopamine agonists in 5%. Mean cost of acromegaly treatment was 9.668€ (data estimated in 2009 and adjusted in 2010), of which 71% was due to the cost of SSAs. Patients treated with pegvisomant have a more aggressive form of the disease and higher comorbidity rates.

  4. Epidemiology of childhood food allergy.

    Science.gov (United States)

    Dyer, Ashley A; Gupta, Ruchi

    2013-06-01

    Food allergy is a public health problem that affects nearly 6 million children in the United States. The extent to which children, families, and communities live with food allergies varies as much as the range of clinical symptoms associated with the disease itself. Food allergy is defined as the reproducible adverse event that elicits a pathologic immunoglobulin E (IgE)-mediated or non-IgE-mediated reaction. Once an allergic child ingests a specific food allergen, the reaction can result in clinical symptoms ranging from mild hives to life-threatening anaphylaxis.Not surprisingly, food allergies have been shown to limit social interactions and impair children's quality of life due to the ubiquity of food where children live, learn, and play. To ensure the safety of our children, the development of sound policy, clinical practice, and health programs must be informed by current research characterizing childhood food allergy at the population level. To set the stage for understanding the current evidence base, this article reviews: 1) epidemiology of childhood food allergy; 2) severity of symptoms; 3) geographic distribution of childhood food allergy; 4) tolerance; 5) economic impact of childhood food allergy; and 6) future directions in childhood food allergy epidemiological research.

  5. Epidemiology: second-rate science?

    Science.gov (United States)

    Parascandola, M

    1998-01-01

    In recent years epidemiology has come under increasing criticism in regulatory and public arenas for being "unscientific." The tobacco industry has taken advantage of this, insisting for decades that evidence linking cigarettes and lung cancer falls short of proof. Moreover, many epidemiologists remain unduly skeptical and self-conscious about the status of their own causal claims. This situation persists in part because of a widespread belief that only the laboratory can provide evidence sufficient for scientific proof. Adherents of this view erroneously believe that there is no element of uncertainty or inductive inference in the "direct observation" of the laboratory researcher and that epidemiology provides mere "circumstantial" evidence. The historical roots of this attitude can be traced to philosopher John Stuart Mill and physiologist Claude Bernard and their influence on modern experimental thinking. The author uses the debate over cigarettes and lung cancer to examine ideas of proof in medical science and public health, concluding that inductive inference from a limited sample to a larger population is an element in all empirical science.

  6. The dynamics of tuberculosis epidemiology.

    Science.gov (United States)

    Rieder, Hans L

    2014-01-01

    A conceptual framework to study the epidemiologic basis of tuberculosis control is provided. The basic model to discuss the epidemiology of tuberculosis is based on a classification of tuberculosis based on its pathogenesis with exposure, latent infection, tuberculosis, and death from tuberculosis, showing the conditional probabilities leading from one to the next step in the chain of events. Historical data are utilized to demonstrate how the dynamics of tuberculosis over multiple decades have contributed to shape the present. It is shown that the key concept to understand the dynamics is related to current and past incidence and prevalence of latent infection with M. tuberculosis. The dynamics of the epidemic are shaped both by the behaviour of the causative organism of tuberculosis as well as the population structure and changes that take place in parallel in which M. tuberculosis thrives. Both the present and the future shape of the epidemic, as well as the principles applied to its control lie very much in the past of a society. While new risk factors such as HIV or diabetes have been or are emerging more strongly, it is noted that the majority of all new cases emerging cannot be pinned to one or the other such factor. It is the historical experience of a population that offers the most valuable key to understanding the present and the future.

  7. The New Epidemiology--A Challenge to Health Administration. Issues in Epidemiology for Administration.

    Science.gov (United States)

    Crichton, Anne, Ed.; Neuhauser, Duncan, Ed.

    The role of epidemiology in health administration is considered in 11 articles, and three course descriptions and a bibliography are provided. Titles and authors include the following: "The Need for Creative Managerial Epidemiology" (Gary L. Filerman); "The Growing Role of Epidemiology in Health Administration" (Maureen M.…

  8. Generalized product

    OpenAIRE

    Greco,Salvatore; Mesiar, Radko; Rindone, Fabio

    2014-01-01

    Aggregation functions on [0,1] with annihilator 0 can be seen as a generalized product on [0,1]. We study the generalized product on the bipolar scale [–1,1], stressing the axiomatic point of view. Based on newly introduced bipolar properties, such as the bipolar increasingness, bipolar unit element, bipolar idempotent element, several kinds of generalized bipolar product are introduced and studied. A special stress is put on bipolar semicopulas, bipolar quasi-copulas and bipolar copulas.

  9. Generalized product

    OpenAIRE

    Greco, Salvatore; Mesiar, Radko; Rindone, Fabio

    2014-01-01

    Aggregation functions on [0,1] with annihilator 0 can be seen as a generalized product on [0,1]. We study the generalized product on the bipolar scale [–1,1], stressing the axiomatic point of view. Based on newly introduced bipolar properties, such as the bipolar increasingness, bipolar unit element, bipolar idempotent element, several kinds of generalized bipolar product are introduced and studied. A special stress is put on bipolar semicopulas, bipolar quasi-copulas and bipolar copulas.

  10. Noncommutativity Parameter and Composite Fermions

    CERN Document Server

    Jellal, A

    2003-01-01

    In this note, we would like to determine some particular values of noncommutativity parameter $\\te$ and show that the Murthy-Shankar approach is in fact a particular case of a more general one. Indeed, using fractional quantum Hall effect (FQHE) experimental data, one can give a measurement of $\\te$. This measurement can be obtained by considering some values of the filling factor $\

  11. Noncommutativity Parameter and Composite Fermions

    OpenAIRE

    Jellal, Ahmed

    2002-01-01

    We determine some particular values of the noncommutativity parameter \\theta and show that the Murthy-Shankar approach is in fact a particular case of a more general one. Indeed, using the fractional quantum Hall effect (FQHE) experimental data, we give a measurement of \\theta. This measurement can be obtained by considering some values of the filling factor \

  12. Generalized Galilean Genesis

    CERN Document Server

    Nishi, Sakine

    2015-01-01

    The galilean genesis scenario is an alternative to inflation in which the universe starts expanding from Minkowski in the asymptotic past by violating the null energy condition stably. Several concrete models of galilean genesis have been constructed so far within the context of galileon-type scalar-field theories. We give a generic, unified description of the galilean genesis scenario in terms of the Horndeski theory, i.e., the most general scalar-tensor theory with second-order field equations. In doing so we generalize the previous models to have a new parameter (denoted by {\\alpha}) which results in controlling the evolution of the Hubble rate. The background dynamics is investigated to show that the generalized galilean genesis solution is an attractor, similarly to the original model. We also study the nature of primordial perturbations in the generalized galilean genesis scenario. In all the models described by our generalized genesis Lagrangian, amplification of tensor perturbations does not occur as ...

  13. Análise da situação da poliomielite em uma amostra de crianças da cidade de São Paulo, com o auxílio de um parâmetro de vigilância epidemiológica Analysis of the poliomyelitis situation in the city of S. Paulo, Brazil by means of an epidemiologic surveillance parameter

    Directory of Open Access Journals (Sweden)

    Klaus E. Stewien

    1977-09-01

    Full Text Available A situação da poliomielite é analisada em uma amostra de crianças de 0-10 anos de idade da cidade de São Paulo, assistidas pelo Hospital Menino Jesus, com o auxílio de um parâmetro de vigilância epidemiológica - o fator r da dinâmica da imunização. Os resultados de um recente inquérito soro-epidemiológico foram transformados matematicamente na curva de crescimento expressa pela função exponencial y = a+(1-a (1-rt, aumentando-se, com isto, consideravelmente o valor informativo do inquérito. A análise mostrou que pela vacinação oral se imunizaram efetivamente cerca de 50% e 60% do total dos indivíduos da população infantil de 0-10 anos de idade contra os poliovírus dos tipos 1 e 2, respectivamente. Além disto, houve em decorrência da circulação de poliovírus, nesta população, em média, cerca de 85 infecções com poliovírus do tipo 1 e 70 infecções com o poliovírus do tipo 2, por 1.000 habitantes, por ano. Tendo em vista que o coeficiente de morbidade da poliomielite alcança cifras da ordem 31 e 27 casos por 100.000 habitantes, respectivamente nos grupos etários de 0-1 e 1-2 anos de idade, os autores recomendam que não sejam poupados esforços no sentido de que as crianças sejam efetivamente vacinadas dentro do esquema de imunização estabelecido, recebendo a 1ª dose da vacina já aos 2 ou 3 meses de idade.The situation of poliomyelitis in the city of São Paulo is analysed by means of an epidemiologic surveillance parameter - the "r" factor of immunization events. The results of a recent sero-epidemiologic survey realized in this City were transformed into the catalytic growth curve y = a + (1 - a (1 - e-rt. The informative value of the survey is therefore considerably enhanced. The analysis showed that about 50% and 60% of the population of children 0-10 years old were immunized by oral polio vaccination against type 1 and 2 polioviruses, respectivilly-Further, the average rate of effective contacts

  14. GESDB: a platform of simulation resources for genetic epidemiology studies.

    Science.gov (United States)

    Yao, Po-Ju; Chung, Ren-Hua

    2016-01-01

    Computer simulations are routinely conducted to evaluate new statistical methods, to compare the properties among different methods, and to mimic the observed data in genetic epidemiology studies. Conducting simulation studies can become a complicated task as several challenges can occur, such as the selection of an appropriate simulation tool and the specification of parameters in the simulation model. Although abundant simulated data have been generated for human genetic research, currently there is no public database designed specifically as a repository for these simulated data. With the lack of such a database, for similar studies, similar simulations may have been repeated, which resulted in redundant work. Thus, we created an online platform, the Genetic Epidemiology Simulation Database (GESDB), for simulation data sharing and discussion of simulation techniques for genetic epidemiology studies. GESDB consists of a database for storing simulation scripts, simulated data and documentation from published articles as well as a discussion forum, which provides a platform for discussion of the simulated data and exchanging simulation ideas. Moreover, summary statistics such as the simulation tools that are most commonly used and datasets that are most frequently downloaded are provided. The statistics will be informative for researchers to choose an appropriate simulation tool or select a common dataset for method comparisons. GESDB can be accessed at http://gesdb.nhri.org.twDatabase URL: http://gesdb.nhri.org.tw.

  15. Economic epidemiology of avian influenza on smallholder poultry farms.

    Science.gov (United States)

    Boni, Maciej F; Galvani, Alison P; Wickelgren, Abraham L; Malani, Anup

    2013-12-01

    Highly pathogenic avian influenza (HPAI) is often controlled through culling of poultry. Compensating farmers for culled chickens or ducks facilitates effective culling and control of HPAI. However, ensuing price shifts can create incentives that alter the disease dynamics of HPAI. Farmers control certain aspects of the dynamics by setting a farm size, implementing infection control measures, and determining the age at which poultry are sent to market. Their decisions can be influenced by the market price of poultry which can, in turn, be set by policy makers during an HPAI outbreak. Here, we integrate these economic considerations into an epidemiological model in which epidemiological parameters are determined by an outside agent (the farmer) to maximize profit from poultry sales. Our model exhibits a diversity of behaviors which are sensitive to (i) the ability to identify infected poultry, (ii) the average price of infected poultry, (iii) the basic reproductive number of avian influenza, (iv) the effect of culling on the market price of poultry, (v) the effect of market price on farm size, and (vi) the effect of poultry density on disease transmission. We find that under certain market and epidemiological conditions, culling can increase farm size and the total number of HPAI infections. Our model helps to inform the optimization of public health outcomes that best weigh the balance between public health risk and beneficial economic outcomes for farmers.

  16. Economic epidemiology of avian influenza on smallholder poultry farms☆

    Science.gov (United States)

    Boni, Maciej F.; Galvani, Alison P.; Wickelgren, Abraham L.; Malani, Anup

    2013-01-01

    Highly pathogenic avian influenza (HPAI) is often controlled through culling of poultry. Compensating farmers for culled chickens or ducks facilitates effective culling and control of HPAI. However, ensuing price shifts can create incentives that alter the disease dynamics of HPAI. Farmers control certain aspects of the dynamics by setting a farm size, implementing infection control measures, and determining the age at which poultry are sent to market. Their decisions can be influenced by the market price of poultry which can, in turn, be set by policy makers during an HPAI outbreak. Here, we integrate these economic considerations into an epidemiological model in which epidemiological parameters are determined by an outside agent (the farmer) to maximize profit from poultry sales. Our model exhibits a diversity of behaviors which are sensitive to (i) the ability to identify infected poultry, (ii) the average price of infected poultry, (iii) the basic reproductive number of avian influenza, (iv) the effect of culling on the market price of poultry, (v) the effect of market price on farm size, and (vi) the effect of poultry density on disease transmission. We find that under certain market and epidemiological conditions, culling can increase farm size and the total number of HPAI infections. Our model helps to inform the optimization of public health outcomes that best weigh the balance between public health risk and beneficial economic outcomes for farmers. PMID:24161559

  17. Chlorine dioxide water disinfection: a prospective epidemiology study

    Energy Technology Data Exchange (ETDEWEB)

    Michael, G.E.; Miday, R.K.; Bercz, J.P.; Miller, R.G.; Greathouse, D.G.; Kraemer, D.F.; Lucas, J.B.

    1981-01-01

    An epidemiologic study of 198 persons exposed for 3 months to drinking water disinfected with chlorine dioxide was conducted in a rural village. A control population of 118 nonexposed persons was also studied. Pre-exposure hematologic and serum chemical parameters were compared with test results after 115 days of exposure. Chlorite ion levels in the water averaged approximately 5 ppM during the study period. Statistical analysis (ANOVA) of the data failed to identify any significant exposure-related effects. This study suggests that future evaluations of chlorine dioxide disinfection should be directed toward populations with potentially increased sensitivity to hemolytic agents.

  18. Some applications of categorical data analysis to epidemiological studies.

    Science.gov (United States)

    Grizzle, J E; Koch, G G

    1979-10-01

    Several examples of categorized data from epidemiological studies are analyzed to illustrate that more informative analysis than tests of independence can be performed by fitting models. All of the analyses fit into a unified conceptual framework that can be performed by weighted least squares. The methods presented show how to calculate point estimate of parameters, asymptotic variances, and asymptotically valid chi 2 tests. The examples presented are analysis of relative risks estimated from several 2 x 2 tables, analysis of selected features of life tables, construction of synthetic life tables from cross-sectional studies, and analysis of dose-response curves.

  19. Epidemiology of traumatic brain injury in Europe

    NARCIS (Netherlands)

    W. Peeters (Wouter); R. van den Brande (Ruben); S. Polinder (Suzanne); A. Brazinova (Alexandra); E.W. Steyerberg (Ewout); H.F. Lingsma (Hester); A.I.R. Maas (Andrew)

    2015-01-01

    textabstractBackground: Traumatic brain injury (TBI) is a critical public health and socio-economic problem throughout the world, making epidemiological monitoring of incidence, prevalence and outcome of TBI necessary. We aimed to describe the epidemiology of traumatic brain injury in Europe and to

  20. Neuropathic pain: epidemiology, risk factors and prevention

    OpenAIRE

    Kamerman, Peter

    2016-01-01

    Neuropathic pain: epidemiology, risk factors and prevention. Presented in a teaching workshop at the 22nd World Congress of Neurology, Santiago, Chile, 2015 (Workshop title: Neuropathic pain - advice for clinical practice; chair: AL Oaklander, USA).The presentation covers the epidemiology of neuropathic pain.

  1. Epidemiology, diagnosis and management of food allergy

    NARCIS (Netherlands)

    Le, T.T.M.

    2013-01-01

    This thesis describes the epidemiology, diagnosis and management of food allergy. Epidemiology This thesis shows that the prevalence of self-reported adverse food reactions in children and adults was high: 17-25% for all foods and 10-11% for 24 preselected, so-called priority foods. The prevalence o

  2. Processing, Analysis, and General Evaluation of Well-Driller Logs for Estimating Hydrogeologic Parameters of the Glacial Sediments in a Ground-Water Flow Model of the Lake Michigan Basin

    Science.gov (United States)

    Arihood, Leslie D.

    2009-01-01

    In 2005, the U.S. Geological Survey began a pilot study for the National Assessment of Water Availability and Use Program to assess the availability of water and water use in the Great Lakes Basin. Part of the study involves constructing a ground-water flow model for the Lake Michigan part of the Basin. Most ground-water flow occurs in the glacial sediments above the bedrock formations; therefore, adequate representation by the model of the horizontal and vertical hydraulic conductivity of the glacial sediments is important to the accuracy of model simulations. This work processed and analyzed well records to provide the hydrogeologic parameters of horizontal and vertical hydraulic conductivity and ground-water levels for the model layers used to simulated ground-water flow in the glacial sediments. The methods used to convert (1) lithology descriptions into assumed values of horizontal and vertical hydraulic conductivity for entire model layers, (2) aquifer-test data into point values of horizontal hydraulic conductivity, and (3) static water levels into water-level calibration data are presented. A large data set of about 458,000 well driller well logs for monitoring, observation, and water wells was available from three statewide electronic data bases to characterize hydrogeologic parameters. More than 1.8 million records of lithology from the well logs were used to create a lithologic-based representation of horizontal and vertical hydraulic conductivity of the glacial sediments. Specific-capacity data from about 292,000 well logs were converted into horizontal hydraulic conductivity values to determine specific values of horizontal hydraulic conductivity and its aerial variation. About 396,000 well logs contained data on ground-water levels that were assembled into a water-level calibration data set. A lithology-based distribution of hydraulic conductivity was created by use of a computer program to convert well-log lithology descriptions into aquifer or

  3. Epidemiology of Haemophilus ducreyi Infections.

    Science.gov (United States)

    González-Beiras, Camila; Marks, Michael; Chen, Cheng Y; Roberts, Sally; Mitjà, Oriol

    2016-01-01

    The global epidemiology of Haemophilus ducreyi infections is poorly documented because of difficulties in confirming microbiological diagnoses. We evaluated published data on the proportion of genital and nongenital skin ulcers caused by H. ducreyi before and after introduction of syndromic management for genital ulcer disease (GUD). Before 2000, the proportion of GUD caused by H. ducreyi ranged from 0.0% to 69.0% (35 studies in 25 countries). After 2000, the proportion ranged from 0.0% to 15.0% (14 studies in 13 countries). In contrast, H. ducreyi has been recently identified as a causative agent of skin ulcers in children in the tropical regions; proportions ranged from 9.0% to 60.0% (6 studies in 4 countries). We conclude that, although there has been a sustained reduction in the proportion of GUD caused by H. ducreyi, this bacterium is increasingly recognized as a major cause of nongenital cutaneous ulcers.

  4. [Scientific journalism and epidemiological risk].

    Science.gov (United States)

    Luiz, Olinda do Carmo

    2007-01-01

    The importance of the communications media in the construction of symbols has been widely acknowledged. Many of the articles on health published in the daily newspapers mention medical studies, sourced from scientific publications focusing on new risks. The disclosure of risk studies in the mass media is also a topic for editorials and articles in scientific journals, focusing the problem of distortions and the appearance of contradictory news items. The purpose of this paper is to explore the meaning and content of disclosing scientific risk studies in large-circulation daily newspapers, analyzing news items published in Brazil and the scientific publications used as their sources during 2000. The "risk" is presented in the scientific research projects as a "black box" in the meaning of Latour, with the news items downplaying scientific disputes and underscoring associations between behavioral habits and the occurrence of diseases, emphasizing individual aspects of the epidemiological approach, to the detriment of the group.

  5. Trends of Dengue Disease Epidemiology

    Directory of Open Access Journals (Sweden)

    Cucunawangsih

    2017-03-01

    Full Text Available Dengue disease is an emerging mosquito-borne viral infection transmitted between humans by Aedes spp. that are distributed mainly in the tropical and subtropical region along with chikungunya and zika diseases. The distribution of dengue disease is influenced by local variation, such as geography, rainfall, temperature, and rapid urbanization or migration. The epidemy of mosquito-borne infection significantly led to increased number of cases and hyperendemicity which induce a more severe form of dengue accompanied by cocirculation of chikungunya and zika. The rapid global spreading of dengue disease created public health burdens that are presently unfulfilled by the absence of specific therapy, simple diagnosis tool for the early phase, and effective and efficient vector control system. This review highlights the current situation of dengue distribution, epidemiology, and new strategies for early dengue diagnosis and risk prediction of severity that can be used to improve oversight and alleviate the heavy burden of the disease.

  6. Epidemiology of acute wrist trauma

    DEFF Research Database (Denmark)

    Larsen, C F; Lauritsen, Jens

    1993-01-01

    Epidemiological data on wrist injuries in a population can be used for planning by applying them to criteria for care and thus deriving estimates of provisions for care according to currently desirable standards. In a 1-year study all patients > or = 15 years with acute wrist trauma and treated...... in the emergency room were examined according to an algorithm until a diagnosis was established. The overall incidence of wrist trauma was 69 per 10,000 inhabitants per year. Incidence of wrist trauma requiring x-ray examination was 58 per 10,000 per year. The incidence of distal radius fractures was 27 per 10...... using data from a population-based study. A completeness rate of 0.56 (95% confidence interval: 0.31-0.78) was found. An x-ray had been taken for all patients reporting a fracture thus justifying the use of fractures as an incidence measure when comparing groups of patients with wrist trauma....

  7. Epidemiological studies of oral cancer.

    Science.gov (United States)

    Pindborg, J J

    1977-06-01

    The FDI has shown considerable interest in the oral cancer and has in recent years arranged three symposia on the subject. The incidence of oral cancer shows marked geographic differences mostly depending upon environmental factors. In the present paper the epidemiology of oral cancer is illustrated by the relative frequency to total number of cancers and incidence rates from a number of countries. Canada has the highest rate of cancer of the vermilion border, which is extremely rare among dark-skinned people. Even within one country differences may be found, a fact which is illustrated by findings from Czechoslovakia and India. In most of the studies dealing with the etiology of oral cancer tobacco usage in its various forms is shown to be the outstanding factor.

  8. Epidemiology of acute wrist trauma

    DEFF Research Database (Denmark)

    Larsen, C F; Lauritsen, Jens

    1993-01-01

    Epidemiological data on wrist injuries in a population can be used for planning by applying them to criteria for care and thus deriving estimates of provisions for care according to currently desirable standards. In a 1-year study all patients > or = 15 years with acute wrist trauma and treated...... in the emergency room were examined according to an algorithm until a diagnosis was established. The overall incidence of wrist trauma was 69 per 10,000 inhabitants per year. Incidence of wrist trauma requiring x-ray examination was 58 per 10,000 per year. The incidence of distal radius fractures was 27 per 10...... using data from a population-based study. A completeness rate of 0.56 (95% confidence interval: 0.31-0.78) was found. An x-ray had been taken for all patients reporting a fracture thus justifying the use of fractures as an incidence measure when comparing groups of patients with wrist trauma....

  9. On Markov parameters in system identification

    Science.gov (United States)

    Phan, Minh; Juang, Jer-Nan; Longman, Richard W.

    1991-01-01

    A detailed discussion of Markov parameters in system identification is given. Different forms of input-output representation of linear discrete-time systems are reviewed and discussed. Interpretation of sampled response data as Markov parameters is presented. Relations between the state-space model and particular linear difference models via the Markov parameters are formulated. A generalization of Markov parameters to observer and Kalman filter Markov parameters for system identification is explained. These extended Markov parameters play an important role in providing not only a state-space realization, but also an observer/Kalman filter for the system of interest.

  10. Molecular epidemiology and evolution of fish Novirhabdoviruses

    Science.gov (United States)

    Kurath, Gael

    2014-01-01

    The genus Novirhabdoviridae contains several of the important rhabdoviruses that infect fish hosts. There are four established virus species: Infectious hematopoietic necrosis virus (IHNV), Viral hemorrhagic septicemia virus (VHSV), Hirame rhabdovirus(HIRRV), and Snakehead rhabdovirus (SHRV). Viruses of these species vary in host and geographic range, and they have all been studied at the molecular and genomic level. As globally significant pathogens of cultured fish, IHNV and VHSV have been particularly well studied in terms of molecular epidemiology and evolution. Phylogenic analyses of hundreds of field isolates have defined five major genogroups of IHNV and four major genotypes of VHSV worldwide. These phylogenies are informed by the known histories of IHNV and VHSV, each involving a series of viral emergence events that are sometimes associated with host switches, most often into cultured rainbow trout. In general, IHNV has relatively low genetic diversity and a narrow host range, and has been spread from its endemic source in North American to Europe and Asia due to aquaculture activities. In contrast, VHSV has broad host range and high genetic diversity, and the source of emergence events is virus in widespread marine fish reservoirs in the northern Atlantic and Pacific Oceans. Common mechanisms of emergence and host switch events include use of raw feed, proximity to wild fish reservoirs of virus, and geographic translocations of virus or naive fish hosts associated with aquaculture.

  11. The epidemiology of systemic lupus erythematosus.

    Science.gov (United States)

    Jiménez, Sònia; Cervera, Ricard; Font, Josep; Ingelmo, Miguel

    2003-08-01

    Systemic lupus erythematosus (SLE) is the most diverse of the autoimmune diseases because it may affect any organ of the body and display a broad spectrum of clinical and immunological manifestations. Although previously considered a rare disease, SLE now appears to be relatively common in certain groups of the population. This is probably due to the development of several immunological tests that have allowed the description of many atypical or benign cases that otherwise might not be diagnosed. Furthermore, with the introduction since 1982 of a set of more sensitive criteria for SLE classification, more cases can nowadays be detected. In the present article, we review the most important data regarding the incidence and prevalence of this disease in the general population, the epidemiologic information on the patterns of disease expression in specific subsets and the studies on mortality in SLE. An important amount of information comes from the data obtained from the "Euro-Lupus Cohort," a series of 1000 patients with SLE from several European countries that have been followed prospectively since 1991.

  12. Epidemiology of Stuttering: 21st Century Advances

    Science.gov (United States)

    Yairi, Ehud; Ambrose, Nicoline

    2012-01-01

    Epidemiological advances in stuttering during the current century are reviewed within the perspectives of past knowledge. The review is organized in six sections: (a) onset (b) incidence (c) prevalence (d) developmental paths, (e) genetics and (f) subtypes. It is concluded that: (1) most of the risk for stuttering onset is over by age 5, earlier than has been previously thought, with a male-to-female ratio near onset smaller than what has been thought, (2) there are indications that the lifespan incidence in the general population may be higher than the 5% commonly cited in past work, (3) the average prevalence over the lifespan may be lower than the commonly held 1%, (4) the effects of race, ethnicity, culture, bilingualism, and socioeconomic status on the incidence/prevalence of stuttering remain uncertain, (5) longitudinal, as well as incidence and prevalence studies support high levels of natural recovery from stuttering, (6) advances in biological genetic research have brought within reach the identification of candidate genes that contribute to stuttering in the population at large, (7) subtype-differentiation has attracted growing interest, with most of the accumulated evidence supporting a distinction between persistent and recovered subtypes. PMID:23773662

  13. DOE (Department of Energy) Epidemiologic Research Program

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The objective of the Department of Energy (DOE) Epidemiologic Research Program is to determine the human health effects resulting from the generation and use of energy, and of the operation of DOE facilities. The program is divided into seven general areas of activity; the Radiation Effects Research Foundation (RERF) which supports studies of survivors of the atomic weapons in Hiroshima and Nagasaki, mortality and morbidity studies of DOE workers, studies on internally deposited alpha emitters, medical/histologic studies, studies on the aspects of radiation damage, community health surveillance studies, and the development of computational techniques and of databases to make the results as widely useful as possible. Excluding the extensive literature from the RERF, the program has produced 340 publications in scientific journals, contributing significantly to improving the understanding of the health effects of ionizing radiation exposure. In addition, a large number of public presentations were made and are documented elsewhere in published proceedings or in books. The purpose of this bibliography is to present a guide to the research results obtained by scientists supported by the program. The bibliography, which includes doctoral theses, is classified by laboratory and by year and also summarizes the results from individual authors by journal.

  14. Epidemiologic characterization of Colorado backyard bird flocks.

    Science.gov (United States)

    Smith, Emily I; Reif, John S; Hill, Ashley E; Slota, Katharine E; Miller, Ryan S; Bjork, Kathe E; Pabilonia, Kristy L

    2012-06-01

    Backyard gallinaceous bird flocks may play an important role in the spread of infectious diseases within poultry populations as well as the transmission of zoonotic diseases to humans. An epidemiologic characterization was conducted of Colorado backyard flocks to gather information on general flock characteristics, human movement of birds, human-bird interaction, biosecurity practices, and flock health. Our results suggest that backyard poultry flocks in Colorado are small-sized flocks (68.6% of flocks had backyard flock environment may promote bird-to-bird transmission as well as bird-to-human transmission of infectious disease. Birds are primarily housed with free access to the outside (96.85%), and many are moved from the home premises (46.06% within 1 yr). Human contact with backyard flocks is high, biosecurity practices are minimal, and bird health is negatively impacted by increased movement events. Increased knowledge of backyard bird characteristics and associated management practices can provide guidelines for the development of measures to decrease disease transmission between bird populations, decrease disease transmission from birds to humans, and increase the overall health of backyard birds.

  15. Diagnosis and epidemiology of Helicobacter pylori infection.

    Science.gov (United States)

    Calvet, Xavier; Ramírez Lázaro, María-José; Lehours, Philippe; Mégraud, Francis

    2013-09-01

    A limited amount of new information was published in the field of diagnosis and epidemiology of Helicobacter pylori this last year. Besides some improvement in current tests, it is interesting to note the attempts to identify severe disease, for example gastric cancer, by breath analysis using nanomaterial-based sensors. In contrast, the predictive value for gastric cancer and atrophy of pepsinogen determinations was found inadequate. Prevalence studies of H. pylori infection have been carried out in adults and children around the world in the general population but also in specific communities. The usual risk factors were found. In addition, a Japanese study highlighted the role of grandmothers in the familial transmission of H. pylori. A study showed that the infection may not always readily establish itself in children, given the number of transient infections observed. It was also noted that after eradication, a first-year relapse is likely to be a recurrence of the previous infection, while later on it is probably a reinfection with a new strain.

  16. Tea and cancer prevention: epidemiological studies.

    Science.gov (United States)

    Yuan, Jian-Min; Sun, Canlan; Butler, Lesley M

    2011-08-01

    Experimental studies have consistently shown the inhibitory activities of tea extracts on tumorigenesis in multiple model systems. Epidemiological studies, however, have produced inconclusive results in humans. A comprehensive review was conducted to assess the current knowledge on tea consumption and risk of cancers in humans. In general, consumption of black tea was not associated with lower risk of cancer. High intake of green tea was consistently associated with reduced risk of upper gastrointestinal tract cancers after sufficient control for confounders. Limited data support a protective effect of green tea on lung and hepatocellular carcinogenesis. Although observational studies do not support a beneficial role of tea intake on prostate cancer risk, phase II clinical trials have demonstrated an inhibitory effect of green tea extract against the progression of prostate pre-malignant lesions. Green tea may exert beneficial effects against mammary carcinogenesis in premenopausal women and recurrence of breast cancer. There is no sufficient evidence that supports a protective role of tea intake on the development of cancers of the colorectum, pancreas, urinary tract, glioma, lymphoma, and leukemia. Future prospective observational studies with biomarkers of exposure and phase III clinical trials are required to provide definitive evidence for the hypothesized beneficial effect of tea consumption on cancer formation in humans.

  17. Epidemiology of yaws: an update

    Directory of Open Access Journals (Sweden)

    Kazadi WM

    2014-04-01

    Full Text Available Walter M Kazadi,1 Kingsley B Asiedu,2 Nsiire Agana,3 Oriol Mitjà4,51Office of the WHO Representative for Papua New Guinea, World Health Organization, Port Moresby, Papua New Guinea; 2Department of Control of Neglected Tropical Diseases, World Health Organization, Geneva, Switzerland; 3Public Health Division, Ghana Health Service, Accra, Ghana; 4Barcelona Centre for International Health Research, Hospital Clinic, University of Barcelona, Barcelona, Spain; 5Lihir Medical Centre-International SOS, Newcrest Mining, Lihir Island, Papua New GuineaAbstract: Yaws, a neglected tropical disease, is targeted for eradication by 2020 through large-scale mass-treatment programs of endemic communities. A key determinant for the success of the eradication campaign is good understanding of the disease epidemiology. We did a review of historical trends and new information from endemic countries, with the aim of assessing the state of knowledge on yaws disease burden. Transmission of yaws is now present in Africa, Asia, and the South Pacific. At least 12 countries are known to harbor yaws cases and 21 to 42 million people live in endemic areas. Between 2008 and 2012 more than 300,000 new cases were reported to the World Health Organization. Yaws presented high geographical variation within a country or region, high seasonality for incidence of active disease, and evidence that low standards of hygiene predispose to suffering of the disease. Key data issues include low levels of reporting, potential misdiagnosis, and scarce documentation on prevalence of asymptomatic infections. Currently available data most likely underestimates the magnitude of the disease burden. More effort is needed in order to refine accuracy of data currently being reported. A better characterization of the epidemiology of yaws globally is likely to positively impact on planning and implementation of yaws eradication.Keywords: eradication, Treponema pertenue, endemic countries, prevalence

  18. On the epidemiology of influenza

    Directory of Open Access Journals (Sweden)

    Scragg Robert

    2008-02-01

    Full Text Available Abstract The epidemiology of influenza swarms with incongruities, incongruities exhaustively detailed by the late British epidemiologist, Edgar Hope-Simpson. He was the first to propose a parsimonious theory explaining why influenza is, as Gregg said, "seemingly unmindful of traditional infectious disease behavioral patterns." Recent discoveries indicate vitamin D upregulates the endogenous antibiotics of innate immunity and suggest that the incongruities explored by Hope-Simpson may be secondary to the epidemiology of vitamin D deficiency. We identify – and attempt to explain – nine influenza conundrums: (1 Why is influenza both seasonal and ubiquitous and where is the virus between epidemics? (2 Why are the epidemics so explosive? (3 Why do they end so abruptly? (4 What explains the frequent coincidental timing of epidemics in countries of similar latitude? (5 Why is the serial interval obscure? (6 Why is the secondary attack rate so low? (7 Why did epidemics in previous ages spread so rapidly, despite the lack of modern transport? (8 Why does experimental inoculation of seronegative humans fail to cause illness in all the volunteers? (9 Why has influenza mortality of the aged not declined as their vaccination rates increased? We review recent discoveries about vitamin D's effects on innate immunity, human studies attempting sick-to-well transmission, naturalistic reports of human transmission, studies of serial interval, secondary attack rates, and relevant animal studies. We hypothesize that two factors explain the nine conundrums: vitamin D's seasonal and population effects on innate immunity, and the presence of a subpopulation of "good infectors." If true, our revision of Edgar Hope-Simpson's theory has profound implications for the prevention of influenza.

  19. SOME EPIDEMIOLOGIC DATA ON ORAL CLEFTS IN THE NORTHERN NETHERLANDS, 1981-1988

    NARCIS (Netherlands)

    CORNEL, MC; SPREEN, JA; MEIJER, [No Value; SPAUWEN, PHM; DHAR, BK; TENKATE, LP

    1992-01-01

    Cleft lip with or without cleft palate [CL(P)] has a high incidence in the northern Netherlands. Several epidemiological parameters for oral clefts, including both CL(P) and cleft palate (CP), were analysed and compared with the literature. Except for the high prevalence at birth of isolated CL(P) n

  20. Dynamics of shigellosis epidemics: estimating individual-level transmission and reporting rates from national epidemiologic data sets.

    Science.gov (United States)

    Joh, Richard I; Hoekstra, Robert M; Barzilay, Ezra J; Bowen, Anna; Mintz, Eric D; Weiss, Howard; Weitz, Joshua S

    2013-10-15

    Shigellosis, a diarrheal disease, is endemic worldwide and is responsible for approximately 15,000 laboratory-confirmed cases in the United States every year. However, patients with shigellosis often do not seek medical care. To estimate the burden of shigellosis, we extended time-series susceptible-infected-recovered models to infer epidemiologic parameters from underreported case data. We applied the time-series susceptible-infected-recovered-based inference schemes to analyze the largest surveillance data set of Shigella sonnei in the United States from 1967 to 2007 with county-level resolution. The dynamics of shigellosis transmission show strong annual and multiyear cycles, as well as seasonality. By using the schemes, we inferred individual-level parameters of shigellosis infection, including seasonal transmissibilities and basic reproductive number (R0). In addition, this study provides quantitative estimates of the reporting rate, suggesting that the shigellosis burden in the United States may be more than 10 times the number of laboratory-confirmed cases. Although the estimated reporting rate is generally under 20%, and R0 is generally under 1.5, there is a strong negative correlation between estimates of the reporting rate and R0. Such negative correlations are likely to pose identifiability problems in underreported diseases. We discuss complementary approaches that might further disentangle the true reporting rate and R0.