WorldWideScience

Sample records for dependent variables results

  1. Asymptotic Results for Tail Probabilities of Sums of Dependent and Heavy-Tailed Random Variables

    Institute of Scientific and Technical Information of China (English)

    Kam Chuen YUEN; Chuancun YIN

    2012-01-01

    Abstract Let X1,X2,...be a sequence of dependent and heavy-tailed random variables with distributions F1,F2,…. on (-∞,∞),and let т be a nonnegative integer-valued random variable independent of the sequence {Xk,k≥ 1}.In this framework,the asymptotic behavior of the tail probabilities of the quantities Sn =n∑k=1 Xk and S(n) =max1≤k≤n Sk for n > 1,and their randomized versions Sт and S(т) are studied.Some applications to the risk theory are presented.

  2. Energy-dependent variability from accretion flows

    OpenAIRE

    Zdziarski, Andrzej A.

    2005-01-01

    We develop a formalism to calculate energy-dependent fractional variability (rms) in accretion flows. We consider rms spectra resulting from radial dependencies of the level of local variability (as expected from propagation of disturbances in accretion flows) assuming the constant shape of the spectrum emitted at a given radius. We consider the cases when the variability of the flow is either coherent or incoherent between different radial zones. As example local emission, we consider blackb...

  3. Integrating models that depend on variable data

    Science.gov (United States)

    Banks, A. T.; Hill, M. C.

    2016-12-01

    Models of human-Earth systems are often developed with the goal of predicting the behavior of one or more dependent variables from multiple independent variables, processes, and parameters. Often dependent variable values range over many orders of magnitude, which complicates evaluation of the fit of the dependent variable values to observations. Many metrics and optimization methods have been proposed to address dependent variable variability, with little consensus being achieved. In this work, we evaluate two such methods: log transformation (based on the dependent variable being log-normally distributed with a constant variance) and error-based weighting (based on a multi-normal distribution with variances that tend to increase as the dependent variable value increases). Error-based weighting has the advantage of encouraging model users to carefully consider data errors, such as measurement and epistemic errors, while log-transformations can be a black box for typical users. Placing the log-transformation into the statistical perspective of error-based weighting has not formerly been considered, to the best of our knowledge. To make the evaluation as clear and reproducible as possible, we use multiple linear regression (MLR). Simulations are conducted with MatLab. The example represents stream transport of nitrogen with up to eight independent variables. The single dependent variable in our example has values that range over 4 orders of magnitude. Results are applicable to any problem for which individual or multiple data types produce a large range of dependent variable values. For this problem, the log transformation produced good model fit, while some formulations of error-based weighting worked poorly. Results support previous suggestions fthat error-based weighting derived from a constant coefficient of variation overemphasizes low values and degrades model fit to high values. Applying larger weights to the high values is inconsistent with the log

  4. Energy-dependent variability from accretion flows

    CERN Document Server

    Zdziarski, A A

    2005-01-01

    We develop a formalism to calculate energy-dependent fractional variability (rms) in accretion flows. We consider rms spectra resulting from radial dependencies of the level of local variability (as expected from propagation of disturbances in accretion flows) assuming the constant shape of the spectrum emitted at a given radius. We consider the cases when the variability of the flow is either coherent or incoherent between different radial zones. As example local emission, we consider blackbody, Wien and thermal Comptonization spectra. In addition to numerical results, we present a number of analytical formulae for the resulting rms. We also find an analytical formula for the disc Wien spectrum, which we find to be a very good approximation to the disc blackbody. We compare our results to the rms spectrum observed in an ultrasoft state of GRS 1915+105.

  5. Benford's Law and Continuous Dependent Random Variables

    CERN Document Server

    Becker, Thealexa; Miller, Steven J; Ronan, Ryan; Strauch, Frederick W

    2011-01-01

    Many systems exhibit a digit bias. For example, the first digit base 10 of the Fibonacci numbers, or of $2^n$, equals 1 not 10% or 11% of the time, as one would expect if all digits were equally likely, but about 30% of the time. This phenomenon, known as Benford's Law, has many applications, ranging from detecting tax fraud for the IRS to analyzing round-off errors in computer science. The central question is determining which data sets follow Benford's law. Inspired by natural processes such as particle decay, our work examines models for the decomposition of conserved quantities. We prove that in many instances the distribution of lengths of the resulting pieces converges to Benford behavior as the number of divisions grow. The main difficulty is that the resulting random variables are dependent, which we handle by a careful analysis of the dependencies and tools from Fourier analysis to obtain quantified convergence rates.

  6. Limited dependent variable models for panel data

    NARCIS (Netherlands)

    Charlier, E.

    1997-01-01

    Many economic phenomena require limited variable models for an appropriate treatment. In addition, panel data models allow the inclusion of unobserved individual-specific effects. These models are combined in this thesis. Distributional assumptions in the limited dependent variable models are

  7. Validity of a Residualized Dependent Variable after Pretest Covariance Adjustments: Still the Same Variable?

    Science.gov (United States)

    Nimon, Kim; Henson, Robin K.

    2015-01-01

    The authors empirically examined whether the validity of a residualized dependent variable after covariance adjustment is comparable to that of the original variable of interest. When variance of a dependent variable is removed as a result of one or more covariates, the residual variance may not reflect the same meaning. Using the pretest-posttest…

  8. Evolution variable dependence of jet substructure

    CERN Document Server

    Sakaki, Yasuhito

    2015-01-01

    Studies on jet substructure have evolved significantly in recent years. Jet substructure is essentially determined by QCD radiations and non-perturbative effects. Predictions of jet substructure are usually different among Monte Carlo event generators, and are governed by the parton shower algorithm implemented. For leading logarithmic parton shower, even though one of the core variables is the evolution variable, its choice is not unique. We examine evolution variable dependence of the jet substructure by developing a parton shower generator that interpolates between different evolution variables using a parameter $\\alpha$. Jet shape variables and associated jet rates for quark and gluon jets are used to demonstrate the $\\alpha$-dependence of the jet substructure. We find angular ordered shower predicts wider jets, while relative transverse momentum ($p_{\\bot}$) ordered shower predicts narrower jets. This is qualitatively in agreement with the missing phase space of $p_{\\bot}$ ordered showers. Such differenc...

  9. The "Life Potential": a new complex algorithm to assess "Heart Rate Variability" from Holter records for cognitive and diagnostic aims. Preliminary experimental results showing its dependence on age, gender and health conditions

    CERN Document Server

    Barra, Orazio A

    2013-01-01

    Although HRV (Heart Rate Variability) analyses have been carried out for several decades, several limiting factors still make these analyses useless from a clinical point of view. The present paper aims at overcoming some of these limits by introducing the "Life Potential" (BMP), a new mathematical algorithm which seems to exhibit surprising cognitive and predictive capabilities. BMP is defined as a linear combination of five HRV Non-Linear Variables, in turn derived from the thermodynamic formalism of chaotic dynamic systems. The paper presents experimental measurements of BMP (Average Values and Standard Deviations) derived from 1048 Holter tests, matched in age and gender, including a control group of 356 healthy subjects. The main results are: (a) BMP always decreases when the age increases, and its dependence on age and gender is well established; (b) the shape of the age dependence within "healthy people" is different from that found in the general group: this behavior provides evidence of possible illn...

  10. Independent, dependent, and other variables in healthcare and chaplaincy research.

    Science.gov (United States)

    Flannelly, Laura T; Flannelly, Kevin J; Jankowski, Katherine R B

    2014-01-01

    This article begins by defining the term variable and the terms independent variable and dependent variable, providing examples of each. It then proceeds to describe and discuss synonyms for the terms independent variable and dependent variable, including treatment, intervention, predictor, and risk factor, and synonyms for dependent variable, such as response variables and outcomes. The article explains that the terms extraneous, nuisance, and confounding variables refer to any variable that can interfere with the ability to establish relationships between independent variables and dependent variables, and it describes ways to control for such confounds. It further explains that even though intervening, mediating, and moderating variables explicitly alter the relationship between independent variables and dependent variables, they help to explain the causal relationship between them. In addition, the article links terminology about variables with the concept of levels of measurement in research.

  11. Analytic results for the Tsallis thermodynamic variables

    CERN Document Server

    Bhattacharyya, Trambak; Mogliacci, Sylvain

    2016-01-01

    We analytically investigate the thermodynamic variables of a hot and dense system, in the framework of the Tsallis non-extensive classical statistics. After a brief review, we start by recalling the corresponding massless limits for all the thermodynamic variables. We then present the detail of calculation for the exact massive result regarding the pressure -- valid for all values of the $q$-parameter -- as well as the Tsallis $T$-, $\\mu$- and $m$- parameters, the former characterizing the non-extensivity of the system. The results for other thermodynamic variables, in the massive case, readily follow from appropriate differentiations of the pressure, for which we provide the necessary formulas. For the convenience of the reader, we tabulate all of our results. A special emphasis is put on the method used in order to perform these computations, which happens to reduce cumbersome momentum integrals into simpler ones. Numerical consistency between our analytic results and the corresponding usual numerical integ...

  12. Cardinality-dependent Variability in Orthogonal Variability Models

    DEFF Research Database (Denmark)

    Mærsk-Møller, Hans Martin; Jørgensen, Bo Nørregaard

    2012-01-01

    During our work on developing and running a software product line for eco-sustainable greenhouse-production software tools, which currently have three products members we have identified a need for extending the notation of the Orthogonal Variability Model (OVM) to support what we refer to as car......During our work on developing and running a software product line for eco-sustainable greenhouse-production software tools, which currently have three products members we have identified a need for extending the notation of the Orthogonal Variability Model (OVM) to support what we refer...

  13. Maximal Inequalities for Dependent Random Variables

    DEFF Research Database (Denmark)

    Hoffmann-Jorgensen, Jorgen

    2016-01-01

    Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X...

  14. Variability dependencies in product family engineering

    NARCIS (Netherlands)

    Jaring, M; Bosch, J; VanDerLinden, F

    2004-01-01

    In a product family context, software architects anticipate product diversification and design architectures that support variants in both space (multiple contexts) and time (changing contexts). Product diversification is based on the concept of variability: a single architecture and a set of compon

  15. Bayesian Network Models for Local Dependence among Observable Outcome Variables

    Science.gov (United States)

    Almond, Russell G.; Mulder, Joris; Hemat, Lisa A.; Yan, Duanli

    2009-01-01

    Bayesian network models offer a large degree of flexibility for modeling dependence among observables (item outcome variables) from the same task, which may be dependent. This article explores four design patterns for modeling locally dependent observations: (a) no context--ignores dependence among observables; (b) compensatory context--introduces…

  16. Generalized linear models for categorical and continuous limited dependent variables

    CERN Document Server

    Smithson, Michael

    2013-01-01

    Introduction and OverviewThe Nature of Limited Dependent VariablesOverview of GLMsEstimation Methods and Model EvaluationOrganization of This BookDiscrete VariablesBinary VariablesLogistic RegressionThe Binomial GLMEstimation Methods and IssuesAnalyses in R and StataExercisesNominal Polytomous VariablesMultinomial Logit ModelConditional Logit and Choice ModelsMultinomial Processing Tree ModelsEstimation Methods and Model EvaluationAnalyses in R and StataExercisesOrdinal Categorical VariablesModeling Ordinal Variables: Common Practice versus Best PracticeOrdinal Model AlternativesCumulative Mod

  17. Future-dependent Flow Policies with Prophetic Variables

    DEFF Research Database (Denmark)

    Li, Ximeng; Nielson, Flemming; Nielson, Hanne Riis

    2016-01-01

    future-dependent flow policies- policies that can depend on not only the current values of variables, but also their final values. The final values are referred to using what we call prophetic variables, just as the initial values can be referenced using logical variables in Hoare logic. We develop......Content-dependency often plays an important role in the information flow security of real world IT systems. Content dependency gives rise to informative policies and permissive static enforcement, and sometimes avoids the need for downgrading. We develop a static type system to soundly enforce...... and enforce a notion of future-dependent security for open systems, in the spirit of "non-deducibility on strategies". We also illustrate our approach in scenarios where future-dependency has advantages over present-dependency and avoids mixtures of upgradings and downgradings....

  18. The functional central limit theorem for strong near-epoch dependent random variables

    Institute of Scientific and Technical Information of China (English)

    QIU Jin; LIN Zhengyan

    2004-01-01

    The functional central limit theorem for strong near-epoch dependent sequences of random variables is proved.The conditions given improve on previous results in the literature concerning dependence and heterogeneity.

  19. Structural Response Analysis under Dependent Variables Based on Probability Boxes

    National Research Council Canada - National Science Library

    Xiao, Z; Yang, G

    2015-01-01

      This paper considers structural response analysis when structural uncertainty parameters distribution cannot be specified precisely due to lack of information and there are complex dependencies in the variables...

  20. Fixed transaction costs and modelling limited dependent variables

    NARCIS (Netherlands)

    Hempenius, A.L.

    1994-01-01

    As an alternative to the Tobit model, for vectors of limited dependent variables, I suggest a model, which follows from explicitly using fixed costs, if appropriate of course, in the utility function of the decision-maker.

  1. Discovery of Fourier-dependent time lags in cataclysmic variables

    NARCIS (Netherlands)

    Scaringi, S.; Körding, E.; Groot, P.J.; Uttley, P.; Marsh, T.; Knigge, C.; Maccarone, T.; Dhillon, V.S.

    2013-01-01

    We report the first study of Fourier-frequency-dependent coherence and phase/time lags at optical wavelengths of cataclysmic variables (MV Lyr and LU Cam) displaying typical flickering variability in white light. Observations were performed on the William Herschel Telescope using ULTRACAM. Light

  2. Multivariate Regression with Monotone Missing Observation of the Dependent Variables

    NARCIS (Netherlands)

    Raats, V.M.; van der Genugten, B.B.; Moors, J.J.A.

    2002-01-01

    Multivariate regression is discussed, where the observations of the dependent variables are (monotone) missing completely at random; the explanatory variables are assumed to be completely observed.We discuss OLS-, GLS- and a certain form of E(stimated) GLS-estimation.It turns out that

  3. LARGE DEVIATIONS AND MODERATE DEVIATIONS FOR SUMS OF NEGATIVELY DEPENDENT RANDOM VARIABLES

    Institute of Scientific and Technical Information of China (English)

    Liu Li; Wan Chenggao; Feng Yanqin

    2011-01-01

    In this article, we obtain the large deviations and moderate deviations for negatively dependent (ND) and non-identically distributed random variables defined on (-∞, +∞). The results show that for some non-identical random variables, precise large deviations and moderate deviations remain insensitive to negative dependence structure.

  4. Growth variability in a tissue governed by stress dependent growth

    Science.gov (United States)

    Alim, Karen; Boudaoud, Arezki

    2012-02-01

    Cell wall mechanics lie at the heart of plant cell growth and tissue morphogenesis. Conversely, mechanical forces generated at tissue level can feedback on cellular dynamics. Differential growth of neighboring cells is one eminent origin of mechanical forces and stresses in tissues where cells adhere to each other. How can stresses arising from differential growth orchestrate large scale tissue growth? We show that cell growth coupled to the cell's main stress can reduce or increase tissue growth variability. Employing a cell-based two dimensional tissue model we investigate the dynamics of a tissue with stress depending growth dynamics. We find that the exact cell division rule strongly affects not only the tissue geometry and topology but also its growth dynamics. Our results should enable to infer underlying growth dynamics from live tissue statistics.

  5. Inter-laboratory consistency and variability in the buccal micronucleus cytome assay depends on biomarker scored and laboratory experience: results from the HUMNxl international inter-laboratory scoring exercise.

    Science.gov (United States)

    Bolognesi, Claudia; Knasmueller, Siegfried; Nersesyan, Armen; Roggieri, Paola; Ceppi, Marcello; Bruzzone, Marco; Blaszczyk, Ewa; Mielzynska-Svach, Danuta; Milic, Mirta; Bonassi, Stefano; Benedetti, Danieli; Da Silva, Juliana; Toledo, Raphael; Salvadori, Daisy Maria Fávero; Groot de Restrepo, Helena; Filipic, Metka; Hercog, Klara; Aktas, Ayça; Burgaz, Sema; Kundi, Michael; Grummt, Tamara; Thomas, Philip; Hor, Maryam; Escudero-Fung, Maria; Holland, Nina; Fenech, Michael

    2017-03-01

    The buccal micronucleus cytome (BMNcyt) assay in uncultured exfoliated epithelial cells from oral mucosa is widely applied in biomonitoring human exposures to genotoxic agents and is also proposed as a suitable test for prescreening and follow-up of precancerous oral lesions. The main limitation of the assay is the large variability observed in the baseline values of micronuclei (MNi) and other nuclear anomalies mainly related to different scoring criteria. The aim of this international collaborative study, involving laboratories with different level of experience, was to evaluate the inter- and intra-laboratory variations in the BMNcyt parameters, using recently implemented guidelines, in scoring cells from the same pooled samples obtained from healthy subjects (control group) and from cancer patients undergoing radiotherapy (treated group). The results indicate that all laboratories correctly discriminated samples from the two groups by a significant increase of micronucleus (MN) and nuclear bud (NBUD) frequencies and differentiated binucleated (BN) cells, associated with the exposure to ionizing radiation. The experience of the laboratories was shown to play an important role in the identification of the different cell types and nuclear anomalies. MN frequency in differentiated mononucleated (MONO) and BN cells showed the greatest consistency among the laboratories and low variability was also detected in the frequencies of MONO and BN cells. A larger variability was observed in classifying the different cell types, indicating the subjectivity in the interpretation of some of the scoring criteria while reproducibility of the results between scoring sessions was very good. An inter-laboratory calibration exercise is strongly recommended before starting studies with BMNcyt assay involving multiple research centers. © The Author 2016. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions

  6. Statistical Dependence of Pipe Breaks on Explanatory Variables

    Directory of Open Access Journals (Sweden)

    Patricia Gómez-Martínez

    2017-02-01

    Full Text Available Aging infrastructure is the main challenge currently faced by water suppliers. Estimation of assets lifetime requires reliable criteria to plan assets repair and renewal strategies. To do so, pipe break prediction is one of the most important inputs. This paper analyzes the statistical dependence of pipe breaks on explanatory variables, determining their optimal combination and quantifying their influence on failure prediction accuracy. A large set of registered data from Madrid water supply network, managed by Canal de Isabel II, has been filtered, classified and studied. Several statistical Bayesian models have been built and validated from the available information with a technique that combines reference periods of time as well as geographical location. Statistical models of increasing complexity are built from zero up to five explanatory variables following two approaches: a set of independent variables or a combination of two joint variables plus an additional number of independent variables. With the aim of finding the variable combination that provides the most accurate prediction, models are compared following an objective validation procedure based on the model skill to predict the number of pipe breaks in a large set of geographical locations. As expected, model performance improves as the number of explanatory variables increases. However, the rate of improvement is not constant. Performance metrics improve significantly up to three variables, but the tendency is softened for higher order models, especially in trunk mains where performance is reduced. Slight differences are found between trunk mains and distribution lines when selecting the most influent variables and models.

  7. Sampling designs dependent on sample parameters of auxiliary variables

    CERN Document Server

    Wywiał, Janusz L

    2015-01-01

    The book offers a valuable resource for students and statisticians whose work involves survey sampling. An estimation of the population parameters in finite and fixed populations assisted by auxiliary variables is considered. New sampling designs dependent on moments or quantiles of auxiliary variables are presented on the background of the classical methods. Accuracies of the estimators based on original sampling design are compared with classical estimation procedures. Specific conditional sampling designs are applied to problems of small area estimation as well as to estimation of quantiles of variables under study. .

  8. Testing Dependent Correlations with Nonoverlapping Variables: A Monte Carlo Simulation

    Science.gov (United States)

    Silver, N. Clayton; Hittner, James B.; May, Kim

    2004-01-01

    The authors conducted a Monte Carlo simulation of 4 test statistics or comparing dependent correlations with no variables in common. Empirical Type 1 error rates and power estimates were determined for K. Pearson and L. N. G. Filon's (1898) z, O. J. Dunn and V. A. Clark's (1969) z, J. H. Steiger's (1980) original modification of Dunn and Clark's…

  9. Complete Moment Convergence and Mean Convergence for Arrays of Rowwise Extended Negatively Dependent Random Variables

    Directory of Open Access Journals (Sweden)

    Yongfeng Wu

    2014-01-01

    Full Text Available The authors first present a Rosenthal inequality for sequence of extended negatively dependent (END random variables. By means of the Rosenthal inequality, the authors obtain some complete moment convergence and mean convergence results for arrays of rowwise END random variables. The results in this paper extend and improve the corresponding theorems by Hu and Taylor (1997.

  10. Human phoneme recognition depending on speech-intrinsic variability.

    Science.gov (United States)

    Meyer, Bernd T; Jürgens, Tim; Wesker, Thorsten; Brand, Thomas; Kollmeier, Birger

    2010-11-01

    The influence of different sources of speech-intrinsic variation (speaking rate, effort, style and dialect or accent) on human speech perception was investigated. In listening experiments with 16 listeners, confusions of consonant-vowel-consonant (CVC) and vowel-consonant-vowel (VCV) sounds in speech-weighted noise were analyzed. Experiments were based on the OLLO logatome speech database, which was designed for a man-machine comparison. It contains utterances spoken by 50 speakers from five dialect/accent regions and covers several intrinsic variations. By comparing results depending on intrinsic and extrinsic variations (i.e., different levels of masking noise), the degradation induced by variabilities can be expressed in terms of the SNR. The spectral level distance between the respective speech segment and the long-term spectrum of the masking noise was found to be a good predictor for recognition rates, while phoneme confusions were influenced by the distance to spectrally close phonemes. An analysis based on transmitted information of articulatory features showed that voicing and manner of articulation are comparatively robust cues in the presence of intrinsic variations, whereas the coding of place is more degraded. The database and detailed results have been made available for comparisons between human speech recognition (HSR) and automatic speech recognizers (ASR).

  11. The discovery of timescale-dependent color variability of quasars

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yu-Han; Wang, Jun-Xian; Chen, Xiao-Yang [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zheng, Zhen-Ya, E-mail: sunyh92@mail.ustc.edu.cn, E-mail: jxw@ustc.edu.cn [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)

    2014-09-01

    Quasars are variable on timescales from days to years in UV/optical and generally appear bluer while they brighten. The physics behind the variations in fluxes and colors remains unclear. Using Sloan Digital Sky Survey g- and r-band photometric monitoring data for quasars in Stripe 82, we find that although the flux variation amplitude increases with timescale, the color variability exhibits the opposite behavior. The color variability of quasars is prominent at timescales as short as ∼10 days, but gradually reduces toward timescales up to years. In other words, the variable emission at shorter timescales is bluer than that at longer timescales. This timescale dependence is clearly and consistently detected at all redshifts from z = 0 to 3.5; thus, it cannot be due to contamination to broadband photometry from emission lines that do not respond to fast continuum variations. The discovery directly rules out the possibility that simply attributes the color variability to contamination from a non-variable redder component such as the host galaxy. It cannot be interpreted as changes in global accretion rate either. The thermal accretion disk fluctuation model is favored in the sense that fluctuations in the inner, hotter region of the disk are responsible for short-term variations, while longer-term and stronger variations are expected from the larger and cooler disk region. An interesting implication is that one can use quasar variations at different timescales to probe disk emission at different radii.

  12. The Discovery of Timescale-Dependent Color Variability of Quasars

    CERN Document Server

    Sun, Yu-Han; Chen, Xiao-Yang; Zheng, Zhen-Ya

    2014-01-01

    Quasars are variable on timescales from days to years in UV/optical, and generally appear bluer while they brighten. The physics behind the variations in fluxes and colors remains unclear. Using SDSS g and r band photometric monitoring data of quasars in Stripe 82, we find that although the flux variation amplitude increases with timescale, the color variability exhibits opposite behavior. The color variability of quasars is prominent at timescales as short as ~ 10 days, but gradually reduces toward timescales up to years. In other words, the variable emission at shorter timescales is bluer than that at longer timescales. This timescale dependence is clearly and consistently detected at all redshifts from z = 0 to 3.5, thus can not be due to contaminations to broadband photometry from emission lines which do not respond to fast continuum variations. The discovery directly rules out the possibility that simply attributes the color variability to contamination from a non-variable redder component, such as the h...

  13. THE TIME DOMAIN SPECTROSCOPIC SURVEY: VARIABLE SELECTION AND ANTICIPATED RESULTS

    Energy Technology Data Exchange (ETDEWEB)

    Morganson, Eric; Green, Paul J. [Harvard Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 (United States); Anderson, Scott F.; Ruan, John J. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Myers, Adam D. [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Eracleous, Michael; Brandt, William Nielsen [Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Kelly, Brandon [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106-9530 (United States); Badenes, Carlos [Department of Physics and Astronomy and Pittsburgh Particle Physics, Astrophysics and Cosmology Center (PITT PACC), University of Pittsburgh, 3941 O’Hara St, Pittsburgh, PA 15260 (United States); Bañados, Eduardo [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Blanton, Michael R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Bershady, Matthew A. [Department of Astronomy, University of Wisconsin, 475 N. Charter St., Madison, WI 53706 (United States); Borissova, Jura [Instituto de Física y Astronomía, Universidad de Valparaíso, Av. Gran Bretaña 1111, Playa Ancha, Casilla 5030, and Millennium Institute of Astrophysics (MAS), Santiago (Chile); Burgett, William S. [GMTO Corp, Suite 300, 251 S. Lake Ave, Pasadena, CA 91101 (United States); Chambers, Kenneth, E-mail: emorganson@cfa.harvard.edu [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); and others

    2015-06-20

    We present the selection algorithm and anticipated results for the Time Domain Spectroscopic Survey (TDSS). TDSS is an Sloan Digital Sky Survey (SDSS)-IV Extended Baryon Oscillation Spectroscopic Survey (eBOSS) subproject that will provide initial identification spectra of approximately 220,000 luminosity-variable objects (variable stars and active galactic nuclei across 7500 deg{sup 2} selected from a combination of SDSS and multi-epoch Pan-STARRS1 photometry. TDSS will be the largest spectroscopic survey to explicitly target variable objects, avoiding pre-selection on the basis of colors or detailed modeling of specific variability characteristics. Kernel Density Estimate analysis of our target population performed on SDSS Stripe 82 data suggests our target sample will be 95% pure (meaning 95% of objects we select have genuine luminosity variability of a few magnitudes or more). Our final spectroscopic sample will contain roughly 135,000 quasars and 85,000 stellar variables, approximately 4000 of which will be RR Lyrae stars which may be used as outer Milky Way probes. The variability-selected quasar population has a smoother redshift distribution than a color-selected sample, and variability measurements similar to those we develop here may be used to make more uniform quasar samples in large surveys. The stellar variable targets are distributed fairly uniformly across color space, indicating that TDSS will obtain spectra for a wide variety of stellar variables including pulsating variables, stars with significant chromospheric activity, cataclysmic variables, and eclipsing binaries. TDSS will serve as a pathfinder mission to identify and characterize the multitude of variable objects that will be detected photometrically in even larger variability surveys such as Large Synoptic Survey Telescope.

  14. The Time Domain Spectroscopic Survey: Variable Selection and Anticipated Results

    Science.gov (United States)

    Morganson, Eric; Green, Paul J.; Anderson, Scott F.; Ruan, John J.; Myers, Adam D.; Eracleous, Michael; Kelly, Brandon; Badenes, Carlos; Bañados, Eduardo; Blanton, Michael R.; Bershady, Matthew A.; Borissova, Jura; Brandt, William Nielsen; Burgett, William S.; Chambers, Kenneth; Draper, Peter W.; Davenport, James R. A.; Flewelling, Heather; Garnavich, Peter; Hawley, Suzanne L.; Hodapp, Klaus W.; Isler, Jedidah C.; Kaiser, Nick; Kinemuchi, Karen; Kudritzki, Rolf P.; Metcalfe, Nigel; Morgan, Jeffrey S.; Pâris, Isabelle; Parvizi, Mahmoud; Poleski, Radosław; Price, Paul A.; Salvato, Mara; Shanks, Tom; Schlafly, Eddie F.; Schneider, Donald P.; Shen, Yue; Stassun, Keivan; Tonry, John T.; Walter, Fabian; Waters, Chris Z.

    2015-06-01

    We present the selection algorithm and anticipated results for the Time Domain Spectroscopic Survey (TDSS). TDSS is an Sloan Digital Sky Survey (SDSS)-IV Extended Baryon Oscillation Spectroscopic Survey (eBOSS) subproject that will provide initial identification spectra of approximately 220,000 luminosity-variable objects (variable stars and active galactic nuclei across 7500 deg2 selected from a combination of SDSS and multi-epoch Pan-STARRS1 photometry. TDSS will be the largest spectroscopic survey to explicitly target variable objects, avoiding pre-selection on the basis of colors or detailed modeling of specific variability characteristics. Kernel Density Estimate analysis of our target population performed on SDSS Stripe 82 data suggests our target sample will be 95% pure (meaning 95% of objects we select have genuine luminosity variability of a few magnitudes or more). Our final spectroscopic sample will contain roughly 135,000 quasars and 85,000 stellar variables, approximately 4000 of which will be RR Lyrae stars which may be used as outer Milky Way probes. The variability-selected quasar population has a smoother redshift distribution than a color-selected sample, and variability measurements similar to those we develop here may be used to make more uniform quasar samples in large surveys. The stellar variable targets are distributed fairly uniformly across color space, indicating that TDSS will obtain spectra for a wide variety of stellar variables including pulsating variables, stars with significant chromospheric activity, cataclysmic variables, and eclipsing binaries. TDSS will serve as a pathfinder mission to identify and characterize the multitude of variable objects that will be detected photometrically in even larger variability surveys such as Large Synoptic Survey Telescope.

  15. Quadratic time dependent Hamiltonians and separation of variables

    Science.gov (United States)

    Anzaldo-Meneses, A.

    2017-06-01

    Time dependent quantum problems defined by quadratic Hamiltonians are solved using canonical transformations. The Green's function is obtained and a comparison with the classical Hamilton-Jacobi method leads to important geometrical insights like exterior differential systems, Monge cones and time dependent Gaussian metrics. The Wei-Norman approach is applied using unitary transformations defined in terms of generators of the associated Lie groups, here the semi-direct product of the Heisenberg group and the symplectic group. A new explicit relation for the unitary transformations is given in terms of a finite product of elementary transformations. The sequential application of adequate sets of unitary transformations leads naturally to a new separation of variables method for time dependent Hamiltonians, which is shown to be related to the Inönü-Wigner contraction of Lie groups. The new method allows also a better understanding of interacting particles or coupled modes and opens an alternative way to analyze topological phases in driven systems.

  16. Weak laws of large numbers for arrays of rowwise negatively dependent random variables

    Directory of Open Access Journals (Sweden)

    R. L. Taylor

    2001-01-01

    Full Text Available Weak laws of large numbers for arrays of rowwise negatively dependent random variables are obtained in this paper. The more general hypothesis of negative dependence relaxes the usual assumption of independence. The moment conditions are similar to previous results, and the stochastic bounded condition also provides a generalization of the usual distributional assumptions.

  17. Exercise Training Improves Heart Rate Variability after Methamphetamine Dependency

    Science.gov (United States)

    Dolezal, Brett A.; Chudzynski, Joy; Dickerson, Daniel; Mooney, Larissa; Rawson, Richard A.; Garfinkel, Alan; Cooper, Christopher B.

    2014-01-01

    Purpose Heart rate variability (HRV) reflects a healthy autonomic nervous system and is increased with physical training. Methamphetamine dependence (MD) causes autonomic dysfunction and diminished HRV. We compared recently abstinent MD participants with age-matched, drug free controls (DF) and also investigated whether HRV can be improved with exercise training in the MD participants. Methods In 50 participants (MD=28; DF=22) resting heart rate (R-R intervals) was recorded over 5 min while seated using a monitor affixed to a chest strap. Previously reported time-domain (SDNN, RMSSD, pNN50) and frequency-domain (LFnu, HFnu, LF/HF) parameters of HRV were calculated with customized software. MD were randomized to thrice weekly exercise training (ME=14) or equal attention without training (MC=14) over 8 weeks. Groups were compared using paired and unpaired t-tests. Statistical significance was set at P≤0.05. Results Participant characteristics were matched between groups: age 33±6 years; body mass 82.7±12 kg, BMI 26.8±4.1 kg•min−2, mean±SD. Compared with DF, the MD group had significantly higher resting heart rate (P<0.05), LFnu, and LF/HF (P<0.001) as well as lower SDNN, RMSSD, pNN50 and HFnu (all P<0.001). At randomization, HRV indices were similar between ME and MC groups. However, after training, the ME group significantly (all P<0.001) increased SDNN (+14.7±2.0 ms, +34%), RMSSD (+19.6±4.2 ms, +63%), pNN50 (+22.6±2.7%, +173%), HFnu (+14.2±1.9, +60%) and decreased HR (−5.2±1.1 beats·min−1, −7%), LFnu (−9.6±1.5, −16%) and LF/HF (−0.7±0.3, −19%). These measures did not change from baseline in the MC group. Conclusion HRV, based on several conventional indices, was diminished in recently abstinent, methamphetamine dependent individuals. Moreover, physical training yielded a marked increase of HRV representing increased vagal modulation or improved autonomic balance. PMID:24162556

  18. Epoch-dependent absorption line profile variability in lambda Cep

    CERN Document Server

    Uuh-Sonda, J M; Eenens, P; Mahy, L; Palate, M; Gosset, E; Flores, C A

    2014-01-01

    We present the analysis of a multi-epoch spectroscopic monitoring campaign of the O6Ief star lambda Cep. Previous observations reported the existence of two modes of non-radial pulsations in this star. Our data reveal a much more complex situation. The frequency content of the power spectrum considerably changes from one epoch to the other. We find no stable frequency that can unambiguously be attributed to pulsations. The epoch-dependence of the frequencies and variability patterns are similar to what is seen in the wind emission lines of this and other Oef stars, suggesting that both phenomena likely have the same, currently still unknown, origin.

  19. Effect of methamphetamine dependence on heart rate variability.

    Science.gov (United States)

    Henry, Brook L; Minassian, Arpi; Perry, William

    2012-05-01

    Methamphetamine (METH) is an increasing popular and highly addictive stimulant associated with autonomic nervous system (ANS) dysfunction, cardiovascular pathology and neurotoxicity. Heart rate variability (HRV) has been used to assess autonomic function and predict mortality in cardiac disorders and drug intoxication, but has not been characterized in METH use. We recorded HRV in a sample of currently abstinent individuals with a history of METH dependence compared to age- and gender-matched drug-free comparison subjects. HRV was assessed using time domain, frequency domain, and non-linear entropic analyses in 17 previously METH-dependent and 21 drug-free comparison individuals during a 5 minute rest period. The METH-dependent group demonstrated significant reduction in HRV, reduced parasympathetic activity, and diminished heartbeat complexity relative to comparison participants. More recent METH use was associated with increased sympathetic tone. Chronic METH exposure may be associated with decreased HRV, impaired vagal function, and reduction in heart rate complexity as assessed by multiple methods of analysis. We discuss and review evidence that impaired HRV may be related to the cardiotoxic or neurotoxic effects of prolonged METH use.

  20. Exercise training improves heart rate variability after methamphetamine dependency.

    Science.gov (United States)

    Dolezal, Brett Andrew; Chudzynski, Joy; Dickerson, Daniel; Mooney, Larissa; Rawson, Richard A; Garfinkel, Alan; Cooper, Christopher B

    2014-06-01

    Heart rate variability (HRV) reflects a healthy autonomic nervous system and is increased with physical training. Methamphetamine dependence (MD) causes autonomic dysfunction and diminished HRV. We compared recently abstinent methamphetamine-dependent participants with age-matched, drug-free controls (DF) and also investigated whether HRV can be improved with exercise training in the methamphetamine-dependent participants. In 50 participants (MD = 28; DF = 22), resting heart rate (HR; R-R intervals) was recorded over 5 min while seated using a monitor affixed to a chest strap. Previously reported time domain (SDNN, RMSSD, pNN50) and frequency domain (LFnu, HFnu, LF/HF) parameters of HRV were calculated with customized software. MD were randomized to thrice-weekly exercise training (ME = 14) or equal attention without training (MC = 14) over 8 wk. Groups were compared using paired and unpaired t-tests. Statistical significance was set at P ≤ 0.05. Participant characteristics were matched between groups (mean ± SD): age = 33 ± 6 yr; body mass = 82.7 ± 12 kg, body mass index = 26.8 ± 4.1 kg·min. Compared with DF, the MD group had significantly higher resting HR (P increased SDNN (+14.7 ± 2.0 ms, +34%), RMSSD (+19.6 ± 4.2 ms, +63%), pNN50 (+22.6% ± 2.7%, +173%), HFnu (+14.2 ± 1.9, +60%), and decreased HR (-5.2 ± 1.1 bpm, -7%), LFnu (-9.6 ± 1.5, -16%), and LF/HF (-0.7 ± 0.3, -19%). These measures did not change from baseline in the MC group. HRV, based on several conventional indices, was diminished in recently abstinent, methamphetamine-dependent individuals. Moreover, physical training yielded a marked increase in HRV, representing increased vagal modulation or improved autonomic balance.

  1. Efficient Estimation of Mutual Information for Strongly Dependent Variables

    CERN Document Server

    Gao, Shuyang; Galstyan, Aram

    2014-01-01

    We demonstrate that a popular class of nonparametric mutual information (MI) estimators based on k-nearest-neighbor graphs requires number of samples that scales exponentially with the true MI. Consequently, accurate estimation of MI between two strongly dependent variables is possible only for prohibitively large sample size. This important yet overlooked shortcoming of the existing estimators is due to their implicit reliance on local uniformity of the underlying joint distribution. We introduce a new estimator that is robust to local non-uniformity, works well with limited data, and is able to capture relationship strengths over many orders of magnitude. We demonstrate the superior performance of the proposed estimator on both synthetic and real-world data.

  2. Characterizing heart rate variability by scale-dependent Lyapunov exponent

    Science.gov (United States)

    Hu, Jing; Gao, Jianbo; Tung, Wen-wen

    2009-06-01

    Previous studies on heart rate variability (HRV) using chaos theory, fractal scaling analysis, and many other methods, while fruitful in many aspects, have produced much confusion in the literature. Especially the issue of whether normal HRV is chaotic or stochastic remains highly controversial. Here, we employ a new multiscale complexity measure, the scale-dependent Lyapunov exponent (SDLE), to characterize HRV. SDLE has been shown to readily characterize major models of complex time series including deterministic chaos, noisy chaos, stochastic oscillations, random 1/f processes, random Levy processes, and complex time series with multiple scaling behaviors. Here we use SDLE to characterize the relative importance of nonlinear, chaotic, and stochastic dynamics in HRV of healthy, congestive heart failure, and atrial fibrillation subjects. We show that while HRV data of all these three types are mostly stochastic, the stochasticity is different among the three groups.

  3. Dependence of NAO variability on coupling with sea ice

    Science.gov (United States)

    Strong, Courtenay; Magnusdottir, Gudrun

    2011-05-01

    The variance of the North Atlantic Oscillation index (denoted N) is shown to depend on its coupling with area-averaged sea ice concentration anomalies in and around the Barents Sea (index denoted B). The observed form of this coupling is a negative feedback whereby positive N tends to produce negative B, which in turn forces negative N. The effects of this feedback in the system are examined by modifying the feedback in two modeling frameworks: a statistical vector autoregressive model ( F VAR) and an atmospheric global climate model ( F CAM) customized so that sea ice anomalies on the lower boundary are stochastic with adjustable sensitivity to the model's evolving N. Experiments show that the variance of N decreases nearly linearly with the sensitivity of B to N, where the sensitivity is a measure of the negative feedback strength. Given that the sea ice concentration field has anomalies, the variance of N goes down as these anomalies become more sensitive to N. If the sea ice concentration anomalies are entirely absent, the variance of N is even smaller than the experiment with the most sensitive anomalies. Quantifying how the variance of N depends on the presence and sensitivity of sea ice anomalies to N has implications for the simulation of N in global climate models. In the physical system, projected changes in sea ice thickness or extent could alter the sensitivity of B to N, impacting the within-season variability and hence predictability of N.

  4. Tail dependence of random variables from ARCH and heavy tailed bilinear models

    Institute of Scientific and Technical Information of China (English)

    潘家柱

    2002-01-01

    Discussed in this paper is the dependent structure in the tails of distributions of random variables from some heavy-tailed stationary nonlinear time series. One class of models discussed is the first-order autoregressive conditional heteroscedastic (ARCH) process introduced by Engle (1982). The other class is the simple first-order bilinear models driven by heavy-tailed innovations. We give some explicit formulas for the asymptotic values of conditional probabilities used for measuring the tail dependence between two random variables from these models. Our results have significant meanings in finance.

  5. On the dependence of QCD splitting functions on the choice of the evolution variable

    CERN Document Server

    Jadach, S; Placzek, W; Skrzypek, M

    2016-01-01

    We show that already at the NLO level the DGLAP evolution kernel Pqq starts to depend on the choice of the evolution variable. We give an explicit example of such a variable, namely the maximum of transverse momenta of emitted partons and we identify a class of evolution variables that leave the NLO Pqq kernel unchanged with respect to the known standard MS-bar results. The kernels are calculated using a modified Curci-Furmanski-Petronzio method which is based on a direct Feynman-graphs calculation.

  6. On the dependence of QCD splitting functions on the choice of the evolution variable

    Science.gov (United States)

    Jadach, S.; Kusina, A.; Placzek, W.; Skrzypek, M.

    2016-08-01

    We show that already at the NLO level the DGLAP evolution kernel P qq starts to depend on the choice of the evolution variable. We give an explicit example of such a variable, namely the maximum of transverse momenta of emitted partons and we identify a class of evolution variables that leave the NLO P qq kernel unchanged with respect to the known standard overline{MS} results. The kernels are calculated using a modified Curci-Furmanski-Petronzio method which is based on a direct Feynman-graphs calculation.

  7. Necessary and sufficient conditions for moderate deviations of dependent random variables with heavy tails

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    This paper studies the moderate deviations of real-valued extended negatively dependent(END) random variables with consistently varying tails.The moderate deviations of partial sums are first given.The results are then used to establish the necessary and sufficient conditions for the moderate deviations of random sums under certain circumstances.

  8. Burrell-Optical-Kepler Survey (BOKS) II: Early Variability Results

    Science.gov (United States)

    Howell, Steve B.; Feldmeier, J.; von Braun, K.; Everett, M.; Mihos, C.; Harding, P.; Knox, C.; Sherry, W.; Lee, T.; Ciardi, D.; Rudick, C.; Proctor, M.; van Belle, G.

    2006-12-01

    We present preliminary results for the photometric time-series data obtained with the BOKS survey (see BOKS I poster Feldmeier et al.). The BOKS survey covers about 1 square degree in the constellation of Cygnus. We obtained nearly 2000 SDSS r-band images spanning a total time period of 39 days. Each point source in our BOKS survey is also present in the single epoch, 7-color photometric survey catalogue being produced by the NASA Discovery program Kepler mission. Light curves of approximately 60,000 point sources, spanning r=14 to 20, are examined and discussed. We will present variability demographics for the BOKS survey including characterization of the light curves into variable classes based on type, color, amplitude, and any extra-solar planet transit candidates.

  9. Delay-slope-dependent stability results of recurrent neural networks.

    Science.gov (United States)

    Li, Tao; Zheng, Wei Xing; Lin, Chong

    2011-12-01

    By using the fact that the neuron activation functions are sector bounded and nondecreasing, this brief presents a new method, named the delay-slope-dependent method, for stability analysis of a class of recurrent neural networks with time-varying delays. This method includes more information on the slope of neuron activation functions and fewer matrix variables in the constructed Lyapunov-Krasovskii functional. Then some improved delay-dependent stability criteria with less computational burden and conservatism are obtained. Numerical examples are given to illustrate the effectiveness and the benefits of the proposed method.

  10. Motivation as an independent and a dependent variable in medical education: a review of the literature.

    Science.gov (United States)

    Kusurkar, R A; Ten Cate, Th J; van Asperen, M; Croiset, G

    2011-01-01

    Motivation in learning behaviour and education is well-researched in general education, but less in medical education. To answer two research questions, 'How has the literature studied motivation as either an independent or dependent variable? How is motivation useful in predicting and understanding processes and outcomes in medical education?' in the light of the Self-determination Theory (SDT) of motivation. A literature search performed using the PubMed, PsycINFO and ERIC databases resulted in 460 articles. The inclusion criteria were empirical research, specific measurement of motivation and qualitative research studies which had well-designed methodology. Only studies related to medical students/school were included. Findings of 56 articles were included in the review. Motivation as an independent variable appears to affect learning and study behaviour, academic performance, choice of medicine and specialty within medicine and intention to continue medical study. Motivation as a dependent variable appears to be affected by age, gender, ethnicity, socioeconomic status, personality, year of medical curriculum and teacher and peer support, all of which cannot be manipulated by medical educators. Motivation is also affected by factors that can be influenced, among which are, autonomy, competence and relatedness, which have been described as the basic psychological needs important for intrinsic motivation according to SDT. Motivation is an independent variable in medical education influencing important outcomes and is also a dependent variable influenced by autonomy, competence and relatedness. This review finds some evidence in support of the validity of SDT in medical education.

  11. Variability of interconnected wind plants: correlation length and its dependence on variability time scale

    Science.gov (United States)

    St. Martin, Clara M.; Lundquist, Julie K.; Handschy, Mark A.

    2015-04-01

    The variability in wind-generated electricity complicates the integration of this electricity into the electrical grid. This challenge steepens as the percentage of renewably-generated electricity on the grid grows, but variability can be reduced by exploiting geographic diversity: correlations between wind farms decrease as the separation between wind farms increases. But how far is far enough to reduce variability? Grid management requires balancing production on various timescales, and so consideration of correlations reflective of those timescales can guide the appropriate spatial scales of geographic diversity grid integration. To answer ‘how far is far enough,’ we investigate the universal behavior of geographic diversity by exploring wind-speed correlations using three extensive datasets spanning continents, durations and time resolution. First, one year of five-minute wind power generation data from 29 wind farms span 1270 km across Southeastern Australia (Australian Energy Market Operator). Second, 45 years of hourly 10 m wind-speeds from 117 stations span 5000 km across Canada (National Climate Data Archive of Environment Canada). Finally, four years of five-minute wind-speeds from 14 meteorological towers span 350 km of the Northwestern US (Bonneville Power Administration). After removing diurnal cycles and seasonal trends from all datasets, we investigate dependence of correlation length on time scale by digitally high-pass filtering the data on 0.25-2000 h timescales and calculating correlations between sites for each high-pass filter cut-off. Correlations fall to zero with increasing station separation distance, but the characteristic correlation length varies with the high-pass filter applied: the higher the cut-off frequency, the smaller the station separation required to achieve de-correlation. Remarkable similarities between these three datasets reveal behavior that, if universal, could be particularly useful for grid management. For high

  12. Initial CGE Model Results Summary Exogenous and Endogenous Variables Tests

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Brian Keith [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Boero, Riccardo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rivera, Michael Kelly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-07

    The following discussion presents initial results of tests of the most recent version of the National Infrastructure Simulation and Analysis Center Dynamic Computable General Equilibrium (CGE) model developed by Los Alamos National Laboratory (LANL). The intent of this is to test and assess the model’s behavioral properties. The test evaluated whether the predicted impacts are reasonable from a qualitative perspective. This issue is whether the predicted change, be it an increase or decrease in other model variables, is consistent with prior economic intuition and expectations about the predicted change. One of the purposes of this effort is to determine whether model changes are needed in order to improve its behavior qualitatively and quantitatively.

  13. Investigation of Dependence between Time-zero and Time-dependent Variability in High-k NMOS Transistors

    CERN Document Server

    Hassan, Mohammad Khaled

    2016-01-01

    Bias Temperature Instability (BTI) is a major reliability concern in CMOS technology, especially with High dielectric constant (High-\\k{appa}/HK) metal gate (MG) transistors. In addition, the time independent process induced variation has also increased because of the aggressive scaling down of devices. As a result, the faster devices at the lower threshold voltage distribution tail experience higher stress, leading to additional skewness in the BTI degradation. Since time dependent dielectric breakdown (TDDB) and stress-induced leakage current (SILC) in NMOS devices are correlated to BTI, it is necessary to investigate the effect of time zero variability on all these effects simultaneously. To that effect, we propose a simulation framework to model and analyze the impact of time-zero variability (in particular, random dopant fluctuations) on different aging effects. For small area devices (~1000 nm2) in 30nm technology, we observe significant effect of Random Dopant Fluctuation (RDF) on BTI induced variabili...

  14. An edgeworth expansion for a sum of M-Dependent random variables

    Directory of Open Access Journals (Sweden)

    Wan Soo Rhee

    1985-01-01

    Full Text Available Given a sequence X1,X2,…,Xn of m-dependent random variables with moments of order 3+α (0<α≦1, we give an Edgeworth expansion of the distribution of Sσ−1(S=X1+X2+…+Xn, σ2=ES2 under the assumption that E[exp(it Sσ1] is small away from the origin. The result is of the best possible order.

  15. Age Dependent Variability in Gene Expression in Fischer 344 ...

    Science.gov (United States)

    Recent evidence suggests older adults may be a sensitive population with regard to environmental exposure to toxic compounds. One source of this sensitivity could be an enhanced variability in response. Studies on phenotypic differences have suggested that variation in response does increase with age. However, few reports address the question of variation in gene expression as an underlying cause for increased variability of phenotypic response in the aged. In this study, we utilized global analysis to compare variation in constitutive gene expression in the retinae of young (4 mos), middle-aged (11 mos) and aged (23 mos) Fischer 344 rats. Three hundred and forty transcripts were identified in which variance in expression increased from 4 to 23 mos of age, while only twelve transcripts were found for which it decreased. Functional roles for identified genes were clustered in basic biological categories including cell communication, function, metabolism and response to stimuli. Our data suggest that population stochastically-induced variability should be considered in assessing sensitivity due to old age. Recent evidence suggests older adults may be a sensitive population with regard to environmental exposure to toxic compounds. One source of this sensitivity could be an enhanced variability in response. Studies on phenotypic differences have suggested that variation in response does increase with age. However, few reports address the question of variation in

  16. New approximating results for data with errors in both variables

    Science.gov (United States)

    Bogdanova, N.; Todorov, S.

    2015-05-01

    We introduce new data from mineral water probe Lenovo Bulgaria, measured with errors in both variables. We apply our Orthonormal Polynomial Expansion Method (OPEM), based on Forsythe recurrence formula to describe the data in the new error corridor. The development of OPEM gives the approximating curves and their derivatives in optimal orthonormal and usual expansions including the errors in both variables with special criteria.

  17. New Results On the Sum of Two Generalized Gaussian Random Variables

    KAUST Repository

    Soury, Hamza

    2015-01-01

    We propose in this paper a new method to compute the characteristic function (CF) of generalized Gaussian (GG) random variable in terms of the Fox H function. The CF of the sum of two independent GG random variables is then deduced. Based on this results, the probability density function (PDF) and the cumulative distribution function (CDF) of the sum distribution are obtained. These functions are expressed in terms of the bivariate Fox H function. Next, the statistics of the distribution of the sum, such as the moments, the cumulant, and the kurtosis, are analyzed and computed. Due to the complexity of bivariate Fox H function, a solution to reduce such complexity is to approximate the sum of two independent GG random variables by one GG random variable with suitable shape factor. The approximation method depends on the utility of the system so three methods of estimate the shape factor are studied and presented.

  18. New Results on the Sum of Two Generalized Gaussian Random Variables

    KAUST Repository

    Soury, Hamza

    2016-01-06

    We propose in this paper a new method to compute the characteristic function (CF) of generalized Gaussian (GG) random variable in terms of the Fox H function. The CF of the sum of two independent GG random variables is then deduced. Based on this results, the probability density function (PDF) and the cumulative distribution function (CDF) of the sum distribution are obtained. These functions are expressed in terms of the bivariate Fox H function. Next, the statistics of the distribution of the sum, such as the moments, the cumulant, and the kurtosis, are analyzed and computed. Due to the complexity of bivariate Fox H function, a solution to reduce such complexity is to approximate the sum of two independent GG random variables by one GG random variable with suitable shape factor. The approximation method depends on the utility of the system so three methods of estimate the shape factor are studied and presented [1].

  19. On an asymptotic distribution of dependent random variables on a 3-dimensional lattice.

    Science.gov (United States)

    Harvey, Danielle J; Weng, Qian; Beckett, Laurel A

    2010-06-15

    We define conditions under which sums of dependent spatial data will be approximately normally distributed. A theorem on the asymptotic distribution of a sum of dependent random variables defined on a 3-dimensional lattice is presented. Examples are also presented.

  20. Irreducibility Results for Compositions of Polynomials in Several Variables

    Indian Academy of Sciences (India)

    Anca Iuliana Bonciocat; Alexandru Zaharescu

    2005-05-01

    We obtain explicit upper bounds for the number of irreducible factors for a class of compositions of polynomials in several variables over a given field. In particular, some irreducibility criteria are given for this class of compositions of polynomials.

  1. On Direction of Dependence in Latent Variable Contexts

    Science.gov (United States)

    von Eye, Alexander; Wiedermann, Wolfgang

    2014-01-01

    Approaches to determining direction of dependence in nonexperimental data are based on the relation between higher-than second-order moments on one side and correlation and regression models on the other. These approaches have experienced rapid development and are being applied in contexts such as research on partner violence, attention deficit…

  2. A duality approach to the worst case value at risk for a sum of dependent random variables with known covariances

    OpenAIRE

    Brice Franke; Michael Stolz

    2009-01-01

    We propose an approach to the aggregation of risks which is based on estimation of simple quantities (such as covariances) associated to a vector of dependent random variables, and which avoids the use of parametric families of copulae. Our main result demonstrates that the method leads to bounds on the worst case Value at Risk for a sum of dependent random variables. Its proof applies duality theory for infinite dimensional linear programs.

  3. Intraspecific variability of European larch for wood properties: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Paques, L.E.; Rozenberg, P. [Institut National de Recherches Agronomiques (INRA), 45 - Olivet (France). Station d`Amelioration des Arbres Forestiers

    1995-12-31

    Wood properties of several natural populations of European larch (Larix decidua Mill) were determined from samples collected in one replicate of the II. International IUFRO provenance experiment, planted in Brittany in 1959. According to provenances, proportion of heartwood ranges from 35 to 58% of basal area, basic density from 442 to 505 g/dm{sup 3} and Young modulus of elasticity from 8474 to 14522 MPa. Positive correlations between girth and heartwood proportion and between wood density and modulus of elasticity but negative correlations between ring width and both density and MOE have been found both at the individual and at the population levels. Variability between and within provenances is high for two major traits (proportion of heartwood and Young modulus of elasticity) for which a SW - NE gradient is shown. For wood density parameters including pilodyn, a greater homogeneity is observed. Besides a now largely recognized superiority for growth traits, Central European populations from the Sudetan Mountains and Central Poland would also produce wood with better properties. On the reverse, Alpine populations from the French Alps growing at low elevations have a slower growth, a denser wood with less heartwood and less strength. Used as a control, the hybrid larch origin (Larix x eurolepis) represents the best compromise for wood properties with the highest strength but an average wood density and one of the highest proportion of heartwood. These preliminary results must be confirmed from a larger set of provenances and completed with other major wood properties such as durability and shrinkage. 17 refs, 2 figs, 6 tabs

  4. Validation of spatial variability in downscaling results from the VALUE perfect predictor experiment

    Science.gov (United States)

    Widmann, Martin; Bedia, Joaquin; Gutiérrez, Jose Manuel; Maraun, Douglas; Huth, Radan; Fischer, Andreas; Keller, Denise; Hertig, Elke; Vrac, Mathieu; Wibig, Joanna; Pagé, Christian; Cardoso, Rita M.; Soares, Pedro MM; Bosshard, Thomas; Casado, Maria Jesus; Ramos, Petra

    2016-04-01

    VALUE is an open European network to validate and compare downscaling methods for climate change research. Within VALUE a systematic validation framework to enable the assessment and comparison of both dynamical and statistical downscaling methods has been developed. In the first validation experiment the downscaling methods are validated in a setup with perfect predictors taken from the ERA-interim reanalysis for the period 1997 - 2008. This allows to investigate the isolated skill of downscaling methods without further error contributions from the large-scale predictors. One aspect of the validation is the representation of spatial variability. As part of the VALUE validation we have compared various properties of the spatial variability of downscaled daily temperature and precipitation with the corresponding properties in observations. We have used two test validation datasets, one European-wide set of 86 stations, and one higher-density network of 50 stations in Germany. Here we present results based on three approaches, namely the analysis of i.) correlation matrices, ii.) pairwise joint threshold exceedances, and iii.) regions of similar variability. We summarise the information contained in correlation matrices by calculating the dependence of the correlations on distance and deriving decorrelation lengths, as well as by determining the independent degrees of freedom. Probabilities for joint threshold exceedances and (where appropriate) non-exceedances are calculated for various user-relevant thresholds related for instance to extreme precipitation or frost and heat days. The dependence of these probabilities on distance is again characterised by calculating typical length scales that separate dependent from independent exceedances. Regionalisation is based on rotated Principal Component Analysis. The results indicate which downscaling methods are preferable if the dependency of variability at different locations is relevant for the user.

  5. Energy decay of a variable-coefficient wave equation with nonlinear time-dependent localized damping

    Directory of Open Access Journals (Sweden)

    Jieqiong Wu

    2015-09-01

    Full Text Available We study the energy decay for the Cauchy problem of the wave equation with nonlinear time-dependent and space-dependent damping. The damping is localized in a bounded domain and near infinity, and the principal part of the wave equation has a variable-coefficient. We apply the multiplier method for variable-coefficient equations, and obtain an energy decay that depends on the property of the coefficient of the damping term.

  6. Early and Midterm Results Following Interventional Coarctoplasty: Evaluation of Variables that Can Affect the Results

    Science.gov (United States)

    Bassiri, Hossein Ali; Shafe, Omid; Sarpooshi, Javad

    2017-01-01

    Background and Objectives Stent coarctoplasty has been approved as the treatment of choice for adult patients with coarctation of the aorta. We have evaluated the early and midterm clinical and procedural results after interventional coarctoplasty. Also, variables that can affect these results were evaluated. Subjects and Methods Gathering clinical, angiographic and procedural data, we evaluated the pre-specified outcomes, including procedural success, complications, the incidence of hypertension after coarctoplasty etc., after the procedure. The effect of pre-specified variables including aortic arch shape, coarctation type and etc. on the procedural result was evaluated. Results Between February 2005 through March 2014, 133 stent coarctoplasty procedures were performed. Median age was 23.5 years old (interquartile range [IQR]:19-28), and 105 (71.9%) were male. Nearly all of the patients were undergone stent coarctoplasty, mostly with cheatham platinum (CP) stents. There was no association between aortic arch morphology and acute procedural complications. Balloon length more than 40 mm (p=0.028), aorta diameter at the site of Coarctation larger than 2.35 mm (p=0.008) was associated with higher rate of restenosis during follow-up. Comparison between the prevalence of hypertension (HTN) before and after coarctoplasty showed a significant reduction in the prevalence of HTN (117 [91.4%] vs. 95 [74.2%] p<0.001). Conclusion Stent coarctoplasty is a low-risk procedure with favorable early and delayed outcomes. Most mortality is related to the patient's comorbid conditions and not to the procedure. PMID:28154597

  7. Stable limits for sums of dependent infinite variance random variables

    DEFF Research Database (Denmark)

    Bartkiewicz, Katarzyna; Jakubowski, Adam; Mikosch, Thomas;

    2011-01-01

    The aim of this paper is to provide conditions which ensure that the affinely transformed partial sums of a strictly stationary process converge in distribution to an infinite variance stable distribution. Conditions for this convergence to hold are known in the literature. However, most...... of these results are qualitative in the sense that the parameters of the limit distribution are expressed in terms of some limiting point process. In this paper we will be able to determine the parameters of the limiting stable distribution in terms of some tail characteristics of the underlying stationary...

  8. Process depending morphology and resulting physical properties of TPU

    Energy Technology Data Exchange (ETDEWEB)

    Frick, Achim, E-mail: achim.frick@hs-aalen.de; Spadaro, Marcel, E-mail: marcel.spadaro@hs-aalen.de [Institute of Polymer Science and Processing (iPSP), Aalen University (Germany)

    2015-12-17

    Thermoplastic polyurethane (TPU) is a rubber like material with outstanding properties, e.g. for seal applications. TPU basically provides high strength, low frictional behavior and excellent wear resistance. Though, due to segmented structure of TPU, which is composed of hard segments (HSs) and soft segments (SSs), physical properties depend strongly on the morphological arrangement of the phase separated HSs at a certain ratio of HSs to SSs. It is obvious that the TPU deforms differently depending on its bulk morphology. Basically, the morphology can either consist of HSs segregated into small domains, which are well dispersed in the SS matrix or of few strongly phase separated large size HS domains embedded in the SS matrix. The morphology development is hardly ruled by the melt processing conditions of the TPU. Depending on the morphology, TPU provides quite different physical properties with respect to strength, deformation behavior, thermal stability, creep resistance and tribological performance. The paper deals with the influence of important melt processing parameters, such as temperature, pressure and shear conditions, on the resulting physical properties tested by tensile and relaxation experiments. Furthermore the morphology is studied employing differential scanning calorimeter (DSC), transmission light microscopy (TLM), scanning electron beam microscopy (SEM) and transmission electron beam microscopy (TEM) investigations. Correlations between processing conditions and resulting TPU material properties are elaborated. Flow and shear simulations contribute to the understanding of thermal and flow induced morphology development.

  9. [Multiple dependent variables LS-SVM regression algorithm and its application in NIR spectral quantitative analysis].

    Science.gov (United States)

    An, Xin; Xu, Shuo; Zhang, Lu-Da; Su, Shi-Guang

    2009-01-01

    In the present paper, on the basis of LS-SVM algorithm, we built a multiple dependent variables LS-SVM (MLS-SVM) regression model whose weights can be optimized, and gave the corresponding algorithm. Furthermore, we theoretically explained the relationship between MLS-SVM and LS-SVM. Sixty four broomcorn samples were taken as experimental material, and the sample ratio of modeling set to predicting set was 51 : 13. We first selected randomly and uniformly five weight groups in the interval [0, 1], and then in the way of leave-one-out (LOO) rule determined one appropriate weight group and parameters including penalizing parameters and kernel parameters in the model according to the criterion of the minimum of average relative error. Then a multiple dependent variables quantitative analysis model was built with NIR spectrum and simultaneously analyzed three chemical constituents containing protein, lysine and starch. Finally, the average relative errors between actual values and predicted ones by the model of three components for the predicting set were 1.65%, 6.47% and 1.37%, respectively, and the correlation coefficients were 0.9940, 0.8392 and 0.8825, respectively. For comparison, LS-SVM was also utilized, for which the average relative errors were 1.68%, 6.25% and 1.47%, respectively, and the correlation coefficients were 0.9941, 0.8310 and 0.8800, respectively. It is obvious that MLS-SVM algorithm is comparable to LS-SVM algorithm in modeling analysis performance, and both of them can give satisfying results. The result shows that the model with MLS-SVM algorithm is capable of doing multi-components NIR quantitative analysis synchronously. Thus MLS-SVM algorithm offers a new multiple dependent variables quantitative analysis approach for chemometrics. In addition, the weights have certain effect on the prediction performance of the model with MLS-SVM, which is consistent with our intuition and is validated in this study. Therefore, it is necessary to optimize

  10. Synaptic Variability Introduces State-Dependent Modulation of Excitatory Spinal Cord Synapses

    Directory of Open Access Journals (Sweden)

    David Parker

    2015-01-01

    Full Text Available The relevance of neuronal and synaptic variability remains unclear. Cellular and synaptic plasticity and neuromodulation are also variable. This could reflect state-dependent effects caused by the variable initial cellular or synaptic properties or direct variability in plasticity-inducing mechanisms. This study has examined state-dependent influences on synaptic plasticity at connections between excitatory interneurons (EIN and motor neurons in the lamprey spinal cord. State-dependent effects were examined by correlating initial synaptic properties with the substance P-mediated plasticity of low frequency-evoked EPSPs and the reduction of the EPSP depression over spike trains (metaplasticity. The low frequency EPSP potentiation reflected an interaction between the potentiation of NMDA responses and the release probability. The release probability introduced a variable state-dependent subtractive influence on the postsynaptic NMDA-dependent potentiation. The metaplasticity was also state-dependent: it was greater at connections with smaller available vesicle pools and high initial release probabilities. This was supported by the significant reduction in the number of connections showing metaplasticity when the release probability was reduced by high Mg2+ Ringer. Initial synaptic properties thus introduce state-dependent influences that affect the potential for plasticity. Understanding these conditions will be as important as understanding the subsequent changes.

  11. Synaptic Variability Introduces State-Dependent Modulation of Excitatory Spinal Cord Synapses.

    Science.gov (United States)

    Parker, David

    2015-01-01

    The relevance of neuronal and synaptic variability remains unclear. Cellular and synaptic plasticity and neuromodulation are also variable. This could reflect state-dependent effects caused by the variable initial cellular or synaptic properties or direct variability in plasticity-inducing mechanisms. This study has examined state-dependent influences on synaptic plasticity at connections between excitatory interneurons (EIN) and motor neurons in the lamprey spinal cord. State-dependent effects were examined by correlating initial synaptic properties with the substance P-mediated plasticity of low frequency-evoked EPSPs and the reduction of the EPSP depression over spike trains (metaplasticity). The low frequency EPSP potentiation reflected an interaction between the potentiation of NMDA responses and the release probability. The release probability introduced a variable state-dependent subtractive influence on the postsynaptic NMDA-dependent potentiation. The metaplasticity was also state-dependent: it was greater at connections with smaller available vesicle pools and high initial release probabilities. This was supported by the significant reduction in the number of connections showing metaplasticity when the release probability was reduced by high Mg(2+) Ringer. Initial synaptic properties thus introduce state-dependent influences that affect the potential for plasticity. Understanding these conditions will be as important as understanding the subsequent changes.

  12. Statistical Portfolio Estimation under the Utility Function Depending on Exogenous Variables

    Directory of Open Access Journals (Sweden)

    Kenta Hamada

    2012-01-01

    Full Text Available In the estimation of portfolios, it is natural to assume that the utility function depends on exogenous variable. From this point of view, in this paper, we develop the estimation under the utility function depending on exogenous variable. To estimate the optimal portfolio, we introduce a function of moments of the return process and cumulant between the return processes and exogenous variable, where the function means a generalized version of portfolio weight function. First, assuming that exogenous variable is a random process, we derive the asymptotic distribution of the sample version of portfolio weight function. Then, an influence of exogenous variable on the return process is illuminated when exogenous variable has a shot noise in the frequency domain. Second, assuming that exogenous variable is nonstochastic, we derive the asymptotic distribution of the sample version of portfolio weight function. Then, an influence of exogenous variable on the return process is illuminated when exogenous variable has a harmonic trend. We also evaluate the influence of exogenous variable on the return process numerically.

  13. Initial Results from the Variable Intensity Sonic Boom Propagation Database

    Science.gov (United States)

    Haering, Edward A., Jr.; Cliatt, Larry J., II; Bunce, Thomas J.; Gabrielson, Thomas B.; Sparrow, Victor W.; Locey, Lance L.

    2008-01-01

    An extensive sonic boom propagation database with low- to normal-intensity booms (overpressures of 0.08 lbf/sq ft to 2.20 lbf/sq ft) was collected for propagation code validation, and initial results and flight research techniques are presented. Several arrays of microphones were used, including a 10 m tall tower to measure shock wave directionality and the effect of height above ground on acoustic level. A sailplane was employed to measure sonic booms above and within the atmospheric turbulent boundary layer, and the sailplane was positioned to intercept the shock waves between the supersonic airplane and the ground sensors. Sailplane and ground-level sonic boom recordings were used to generate atmospheric turbulence filter functions showing excellent agreement with ground measurements. The sonic boom prediction software PCBoom4 was employed as a preflight planning tool using preflight weather data. The measured data of shock wave directionality, arrival time, and overpressure gave excellent agreement with the PCBoom4-calculated results using the measured aircraft and atmospheric data as inputs. C-weighted acoustic levels generally decreased with increasing height above the ground. A-weighted and perceived levels usually were at a minimum for a height where the elevated microphone pressure rise time history was the straightest, which is a result of incident and ground-reflected shock waves interacting.

  14. On an asymptotic distribution of dependent random variables on a 3-dimensional lattice✩

    Science.gov (United States)

    Harvey, Danielle J.; Weng, Qian; Beckett, Laurel A.

    2010-01-01

    We define conditions under which sums of dependent spatial data will be approximately normally distributed. A theorem on the asymptotic distribution of a sum of dependent random variables defined on a 3-dimensional lattice is presented. Examples are also presented. PMID:20436940

  15. A CENTRAL LIMIT THEOREM FOR STRONG NEAR-EPOCH DEPENDENT RANDOM VARIABLES

    Institute of Scientific and Technical Information of China (English)

    LIN ZHENGYAN; QIU JIN

    2004-01-01

    In this paper, a central limit theorem for strong near-epoch dependent sequences of random variables introduced in [9] is showed. Under the same moments condition,the authors essentially weaken the "size" requirement mentioned in other papers about near epoch dependence.

  16. Some Exact Results for the Schroedinger Wave Equation with a Time Dependent Potential

    Science.gov (United States)

    Campbell, Joel

    2009-01-01

    The time dependent Schroedinger equation with a time dependent delta function potential is solved exactly for many special cases. In all other cases the problem can be reduced to an integral equation of the Volterra type. It is shown that by knowing the wave function at the origin, one may derive the wave function everywhere. Thus, the problem is reduced from a PDE in two variables to an integral equation in one. These results are used to compare adiabatic versus sudden changes in the potential. It is shown that adiabatic changes in the p otential lead to conservation of the normalization of the probability density.

  17. Variables predicting elevated portal pressure in alcoholic liver disease. Results of a multivariate analysis

    DEFF Research Database (Denmark)

    Krogsgaard, K; Christensen, E; Gluud, C

    1987-01-01

    In 46 alcoholic patients the association of wedged-to-free hepatic-vein pressure with other variables (clinical, histologic, hemodynamic, and liver function data) was studied by means of multiple regression analysis, taking the wedged-to-free hepatic-vein pressure as the dependent variable. Four ...

  18. The Timescale-dependent Color Variability of Quasars Viewed with /GALEX

    Science.gov (United States)

    Zhu, Fei-Fan; Wang, Jun-Xian; Cai, Zhen-Yi; Sun, Yu-Han

    2016-11-01

    In a recent work by Sun et al., the color variation of quasars, namely the bluer-when-brighter trend, was found to be timescale dependent using the SDSS g/r band light curves in Stripe 82. Such timescale dependence, i.e., bluer variation at shorter timescales, supports the thermal fluctuation origin of the UV/optical variation in quasars, and can be modeled well with the inhomogeneous accretion disk model. In this paper, we extend the study to much shorter wavelengths in the rest frame (down to extreme UV) using GALaxy Evolution eXplorer (GALEX) photometric data of quasars collected in two ultraviolet bands (near-UV and far-UV). We develop Monte Carlo simulations to correct for possible biases due to the considerably larger photometric uncertainties in the GALEX light curves (particularly in the far-UV, compared with the SDSS g/r bands), which otherwise could produce artificial results. We securely confirm the previously discovered timescale dependence of the color variability with independent data sets and at shorter wavelengths. We further find that the slope of the correlation between the amplitude of the color variation and timescale appears even steeper than predicted by the inhomogeneous disk model, which assumes that disk fluctuations follow a damped random walk (DRW) process. The much flatter structure function observed in the far-UV compared with that at longer wavelengths implies deviation from the DRW process in the inner disk, where rest-frame extreme UV radiation is produced.

  19. The Timescale-Dependent Color Variability of Quasars Viewed with GALEX

    CERN Document Server

    Zhu, Fei-Fan; Cai, Zhen-Yi; Sun, Yu-Han

    2016-01-01

    In recent work done by Sun et. al., the color variation of quasars, namely the bluer-when-brighter trend, was found to be timescale-dependent using SDSS $g/r$ band light curves in the Stripe 82. Such timescale dependence, i.e., bluer variation at shorter timescales, supports the thermal fluctuation origin of the UV/optical variation in quasars, and can be well modeled with the inhomogeneous accretion disk model. In this paper, we extend the study to much shorter wavelengths in the rest frame (down to extreme UV), using GALaxy Evolution eXplorer (GALEX) photometric data of quasars collected in two ultraviolet bands (near-UV and far-UV). We develop Monte-Carlo simulations to correct possible biases due to the considerably larger photometric uncertainties in GALEX light curves (particularly in far-UV, comparing with SDSS $g/r$ bands), which otherwise could produce artificial results. We securely confirm the previously discovered timescale dependence of the color variability with independent datasets and at short...

  20. A Bayesian Alternative to Mutual Information for the Hierarchical Clustering of Dependent Random Variables.

    Directory of Open Access Journals (Sweden)

    Guillaume Marrelec

    Full Text Available The use of mutual information as a similarity measure in agglomerative hierarchical clustering (AHC raises an important issue: some correction needs to be applied for the dimensionality of variables. In this work, we formulate the decision of merging dependent multivariate normal variables in an AHC procedure as a Bayesian model comparison. We found that the Bayesian formulation naturally shrinks the empirical covariance matrix towards a matrix set a priori (e.g., the identity, provides an automated stopping rule, and corrects for dimensionality using a term that scales up the measure as a function of the dimensionality of the variables. Also, the resulting log Bayes factor is asymptotically proportional to the plug-in estimate of mutual information, with an additive correction for dimensionality in agreement with the Bayesian information criterion. We investigated the behavior of these Bayesian alternatives (in exact and asymptotic forms to mutual information on simulated and real data. An encouraging result was first derived on simulations: the hierarchical clustering based on the log Bayes factor outperformed off-the-shelf clustering techniques as well as raw and normalized mutual information in terms of classification accuracy. On a toy example, we found that the Bayesian approaches led to results that were similar to those of mutual information clustering techniques, with the advantage of an automated thresholding. On real functional magnetic resonance imaging (fMRI datasets measuring brain activity, it identified clusters consistent with the established outcome of standard procedures. On this application, normalized mutual information had a highly atypical behavior, in the sense that it systematically favored very large clusters. These initial experiments suggest that the proposed Bayesian alternatives to mutual information are a useful new tool for hierarchical clustering.

  1. A Bayesian Alternative to Mutual Information for the Hierarchical Clustering of Dependent Random Variables.

    Science.gov (United States)

    Marrelec, Guillaume; Messé, Arnaud; Bellec, Pierre

    2015-01-01

    The use of mutual information as a similarity measure in agglomerative hierarchical clustering (AHC) raises an important issue: some correction needs to be applied for the dimensionality of variables. In this work, we formulate the decision of merging dependent multivariate normal variables in an AHC procedure as a Bayesian model comparison. We found that the Bayesian formulation naturally shrinks the empirical covariance matrix towards a matrix set a priori (e.g., the identity), provides an automated stopping rule, and corrects for dimensionality using a term that scales up the measure as a function of the dimensionality of the variables. Also, the resulting log Bayes factor is asymptotically proportional to the plug-in estimate of mutual information, with an additive correction for dimensionality in agreement with the Bayesian information criterion. We investigated the behavior of these Bayesian alternatives (in exact and asymptotic forms) to mutual information on simulated and real data. An encouraging result was first derived on simulations: the hierarchical clustering based on the log Bayes factor outperformed off-the-shelf clustering techniques as well as raw and normalized mutual information in terms of classification accuracy. On a toy example, we found that the Bayesian approaches led to results that were similar to those of mutual information clustering techniques, with the advantage of an automated thresholding. On real functional magnetic resonance imaging (fMRI) datasets measuring brain activity, it identified clusters consistent with the established outcome of standard procedures. On this application, normalized mutual information had a highly atypical behavior, in the sense that it systematically favored very large clusters. These initial experiments suggest that the proposed Bayesian alternatives to mutual information are a useful new tool for hierarchical clustering.

  2. Variability in the results of inr (international normalized ratio: a comparison of six commercial thromboplastin brands

    Directory of Open Access Journals (Sweden)

    Fernanda Daniela Serralvo

    2015-05-01

    Full Text Available Introduction: The efficacy and safety in treatment with oral anticoagulants are dependent on the monitoring of the effect of anticoagulants by the prothrombin time (PT. The system INR (International Normalized Ratio was developed to minimize the variability in the PT, mainly because of the thromboplastin reagent used. Objective: Compare the results of INR employing six thromboplastins and plasmas of patients using oral anticoagulants. Materials and Methods: For this study, 96 patients using oral anticoagulants and that had TP collected for monitoring anticoagulants were selected randomly. INR values were determined using six commercially available thromboplastin brands. Results and Discussion: Of the 96 patients, 29 were with the INR between 2 and 3 when used reagents Dade-Behring®, Human do Brasil® and Diagnostica Stago®. Regardless of the range of INR, the results obtained with the reagent Labtest® were statistically different from the Dade-Behring®, from Diagnostica Stago®, Trinity Biotech and Bios Diagnostica®. With INR between 2 and 3 only differences were observed between the results of brands and Bios Diagnostica® Labtest®. With INR above 3, the results of Labtest® were different from the Dade-Behring®, from Diagnostica Stago®, Trinity Biotech® and Bios Diagnostica®. Conclusion: Despite the establishment of INR, there are still significant differences in INR results depending on the thromboplastin brand used, which can interfere with the therapeutic approach in relation to oral anticoagulants.

  3. Time-dependent sleep stage transition model based on heart rate variability.

    Science.gov (United States)

    Takeda, Toki; Mizuno, Osamu; Tanaka, Tomohiro

    2015-01-01

    A new model is proposed to automatically classify sleep stages using heart rate variability (HRV). The generative model, based on the characteristics that the distribution and the transition probabilities of sleep stages depend on the elapsed time from the beginning of sleep, infers the sleep stage with a Gibbs sampler. Experiments were conducted using a public data set consisting of 45 healthy subjects and the model's classification accuracy was evaluated for three sleep stages: wake state, rapid eye movement (REM) sleep, and non-REM sleep. Experimental results demonstrated that the model provides more accurate sleep stage classification than conventional (naive Bayes and Support Vector Machine) models that do not take the above characteristics into account. Our study contributes to improve the quality of sleep monitoring in the daily life using easy-to-wear HRV sensors.

  4. Ionic strength-dependent changes in tentacular ion exchangers with variable ligand density. II. Functional properties.

    Science.gov (United States)

    Bhambure, Rahul; Angelo, James M; Gillespie, Christopher M; Phillips, Michael; Graalfs, Heiner; Lenhoff, Abraham M

    2017-07-14

    The effect of ligand density was studied on protein adsorption and transport behavior in tentacular cation-exchange sorbents at different ionic strengths. Results were obtained for lysozyme, lactoferrin and a monoclonal antibody (mAb) in order to examine the effects of protein size and charge. The combination of ligand density and ionic strength results in extensive variability of the static and dynamic binding capacities, transport rate and binding affinity of the proteins. Uptake and elution experiments were performed to quantify the transport behavior of selected proteins, specifically to estimate intraparticle protein diffusivities. The observed trend of decreasing uptake diffusivities with an increase in ligand density was correlated to structural properties of the ligand-density variants, particularly the accessible porosity. Increasing the ionic strength of the equilibration buffer led to enhanced mass transfer during uptake, independent of the transport model used, and specifically for larger proteins like lactoferrin and mAb, the most significant effects were evident in the sorbent of the highest ligand density. For lysozyme, higher ligand density leads to higher static and dynamic binding capacities whereas for lactoferrin and the mAb, the binding capacity is a complex function of accessible porosity due to ionic strength-dependent changes. Ligand density has a less pronounced effect on the elution rate, presumably due to ionic strength-dependent changes in the pore architecture of the sorbents. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Spatial variability and its scale dependency of observed and modeled soil moisture under different climate conditions

    Directory of Open Access Journals (Sweden)

    B. Li

    2012-09-01

    Full Text Available Past studies on soil moisture spatial variability have been mainly conducted in catchment scales where soil moisture is often sampled over a short time period. Because of limited climate and weather conditions, the observed soil moisture often exhibited smaller dynamic ranges which prevented the complete revelation of soil moisture spatial variability as a function of mean soil moisture. In this study, spatial statistics (mean, spatial variability and skewness of in situ soil moisture measurements (from a continuously monitored network across the US, modeled and satellite retrieved soil moisture obtained in a warm season (198 days were examined at large extent scales (>100 km over three different climate regions. The investigation on in situ measurements revealed that their spatial moments strongly depend on climates, with distinct mean, spatial variability and skewness observed in each climate zone. In addition, an upward convex shape, which was revealed in several smaller scale studies, was observed for the relationship between spatial variability of in situ soil moisture and its spatial mean across dry, intermediate, and wet climates. These climate specific features were vaguely or partially observable in modeled and satellite retrieved soil moisture estimates, which is attributed to the fact that these two data sets do not have climate specific and seasonal sensitive mean soil moisture values, in addition to lack of dynamic ranges. From the point measurements to satellite retrievals, soil moisture spatial variability decreased in each climate region. The three data sources all followed the power law in the scale dependency of spatial variability, with coarser resolution data showing stronger scale dependency than finer ones. The main findings from this study are: (1 the statistical distribution of soil moisture depends on spatial mean soil moisture values and thus need to be derived locally within any given area; (2 the boundedness of soil

  6. Rethinking the dependent variable in voting behavior: On the measurement and analysis of electoral utilities

    NARCIS (Netherlands)

    Eijk, van der Cees; Brug, van der Wouter; Kroh, Martin; Franklin, Mark

    2006-01-01

    As a dependent variable, party choice did not lend itself to analysis by means of powerful multivariate methods until the coming of discrete-choice models, most notably conditional logit and multinomial logit. These methods involve estimating effects on party preferences (utilities) that are post ho

  7. Panel data models extended to spatial error autocorrelation or a spatially lagged dependent variable

    NARCIS (Netherlands)

    Elhorst, J. Paul

    2001-01-01

    This paper surveys panel data models extended to spatial error autocorrelation or a spatially lagged dependent variable. In particular, it focuses on the specification and estimation of four panel data models commonly used in applied research: the fixed effects model, the random effects model, the

  8. Comparing apples and oranges: the dependent variable problem in comparing and evaluating climate change adaptation policies

    NARCIS (Netherlands)

    Dupuis, J.; Biesbroek, G.R.

    2013-01-01

    An increasing number of studies have compared climate change adaptation policies within and between different countries. In this paper we show that these comparative studies suffer from what is known as the ‘‘dependent variable problem’ – the indistinctness of the phenomenon that is being measured,

  9. Comparing apples and oranges: the dependent variable problem in comparing and evaluating climate change adaptation policies

    NARCIS (Netherlands)

    Dupuis, J.; Biesbroek, G.R.

    2013-01-01

    An increasing number of studies have compared climate change adaptation policies within and between different countries. In this paper we show that these comparative studies suffer from what is known as the ‘‘dependent variable problem’ – the indistinctness of the phenomenon that is being measured,

  10. Parametric and Semiparametric Estimation in Models with Misclassified Categorical Dependent Variables

    NARCIS (Netherlands)

    Dustmann, C.; van Soest, A.H.O.

    1999-01-01

    We consider both a parametric and a semiparametric method to account for classification errors on the dependent variable in an ordered response model. The methods are applied to the analysis of self-reported speaking fluency of male immigrants in Germany. We find some substantial differences in para

  11. Parametric and Semiparametric Estimation in Models with Misclassified Categorical Dependent Variables

    NARCIS (Netherlands)

    Dustmann, C.; van Soest, A.H.O.

    1999-01-01

    We consider both a parametric and a semiparametric method to account for classification errors on the dependent variable in an ordered response model. The methods are applied to the analysis of self-reported speaking fluency of male immigrants in Germany. We find some substantial differences in

  12. Field Dependency, n Power and Locus of Control Variables in Alcohol Aversion.

    Science.gov (United States)

    Query, William T.

    1983-01-01

    Compared individual differences and treatment effectiveness in male volunteer alcoholics (N=47) in a 10-day electroconditioning aversion program. Follow-up showed combination therapy was more successful. Internals and hard liquor drinkers tended to be abstinent as predicted. Field dependency was a more unstable variable for outcome. (Author/JAC)

  13. A Maximum Likelihood Method for Latent Class Regression Involving a Censored Dependent Variable.

    Science.gov (United States)

    Jedidi, Kamel; And Others

    1993-01-01

    A method is proposed to simultaneously estimate regression functions and subject membership in "k" latent classes or groups given a censored dependent variable for a cross-section of subjects. Maximum likelihood estimates are obtained using an EM algorithm. The method is illustrated through a consumer psychology application. (SLD)

  14. Dose dependency and individual variability of the lipopolysaccharide-induced bovine acute phase protein response

    DEFF Research Database (Denmark)

    Jacobsen, S.; Andersen, P.H.; Tølbøll, T.

    2004-01-01

    In order to investigate the dose dependency and the individual variability of the lipopolysaccharide (LPS)-induced acute phase protein response in cattle, 8 nonlactating, nonpregnant Danish Holstein cows were challenged 3 times each by intravenous injection of increasing doses (10, 100, and 1000 ng...... for several days after each LPS injection, and their increase or decrease was significantly related to LPS dose. In addition to dose dependency, the response was also dependent on the individual, as APP concentrations differed significantly among cows. To compare APP production in 2 consecutive challenges...

  15. Variability of Creatinine Measurements in Clinical Laboratories: Results from the CRIC Study

    Science.gov (United States)

    Joffe, Marshall; Hsu, Chi-yuan; Feldman, Harold I.; Weir, Matthew; Landis, J.R.; Hamm, L. Lee

    2010-01-01

    Objectives Estimating equations using serum creatinine (SCr) are often used to assess glomerular filtration rate (GFR). Such creatinine (Cr)-based formulae may produce biased estimates of GFR when using Cr measurements that have not been calibrated to reference laboratories. In this paper, we sought to examine the degree of this variation in Cr assays in several laboratories associated with academic medical centers affiliated with the Chronic Renal Insufficiency Cohort (CRIC) Study; to consider how best to correct for this variation, and to quantify the impact of such corrections on eligibility for participation in CRIC. Variability of Cr is of particular concern in the conduct of CRIC, a large multicenter study of subjects with chronic renal disease, because eligibility for the study depends on Cr-based assessment of GFR. Methods A library of 5 large volume plasma specimens from apheresis patients was assembled, representing levels of plasma Cr from 0.8 to 2.4 mg/dl. Samples from this library were used for measurement of Cr at each of the 14 CRIC laboratories repetitively over time. We used graphical displays and linear regression methods to examine the variability in Cr, and used linear regression to develop calibration equations. We also examined the impact of the various calibration equations on the proportion of subjects screened as potential participants who were actually eligible for the study. Results There was substantial variability in Cr assays across laboratories and over time. We developed calibration equations for each laboratory; these equations varied substantially among laboratories and somewhat over time in some laboratories. The laboratory site contributed the most to variability (51% of the variance unexplained by the specimen) and variation with time accounted for another 15%. In some laboratories, calibration equations resulted in differences in eligibility for CRIC of as much as 20%. Conclusions The substantial variability in SCr assays

  16. The effect of small scale variablity in isotopic composition of precipitation on hydrograph separation results

    Science.gov (United States)

    Fischer, Benjamin; van Meerveld, Ilja; Seibert, Jan

    2016-04-01

    became more important. The spatial variability in the isotopic composition of rainfall also affected the minimum fraction pre-event water. Even in events with small spatial differences in the isotopic composition of rainfall, the minimum pre-event water fraction in streamflow was highly dependent on the location of the sampler. The effect of the location of the rainfall sampler was for 4 out of the 10 events as large as the choice of the method to weigh the temporal variability in rainfall isotopic composition. Our results show the importance of accounting for the spatial variability in stable isotope composition of rainfall and that rainfall should be sampled at more than one location, even for small headwater catchments. Failure to do so can significantly affect the minimum fraction of pre-event water in streamflow and thus our understanding of runoff generation mechanisms.

  17. Further improvement on delay-range-dependent stability results for linear systems with interval time-varying delays.

    Science.gov (United States)

    Liu, Pin-Lin

    2013-11-01

    This paper provides an improved delay-range-dependent stability criterion for linear systems with interval time-varying delays. No model transformation and no slack matrix variable are introduced. Furthermore, overly bounding for some cross term is avoided. The resulting criterion has advantages over some previous ones in that it involves fewer matrix variables but has less conservatism, which is established theoretically. Finally, two numerical examples are given to show the effectiveness of the proposed results.

  18. Time-dependent reliability of corrosion-affected RC beams-Part 1: Estimation of time-dependent strengths and associated variability

    Energy Technology Data Exchange (ETDEWEB)

    Bhargava, Kapilesh, E-mail: kapilesh_66@yahoo.co.u [Architecture and Civil Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Mori, Yasuhiro [Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8603 (Japan); Ghosh, A.K. [Reactor Safety Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India)

    2011-05-15

    Research highlights: Predictive models for corrosion-induced damages in RC structures. Formulations for time-dependent flexural and shear strengths of corroded RC beams. Methodology for mean and c.o.v. for time-dependent strengths of corroded RC beams. Simple estimation of mean and c.o.v. for flexural strength with loss of bond. - Abstract: The structural deterioration of reinforced concrete (RC) structures due to reinforcement corrosion is a major worldwide problem. Damages to RC structures due to reinforcement corrosion manifest in the form of expansion, cracking and eventual spalling of the cover concrete; thereby resulting in serviceability and durability degradation of such structures. In addition to loss of cover, RC structure may suffer structural damages due to loss of reinforcement cross-sectional area, and loss of bond between corroded reinforcement and surrounding cracked concrete, sometimes to the extent that the structural failure becomes inevitable. This paper forms the first part of a study which addresses time-dependent reliability analyses of RC beams affected by reinforcement corrosion. In this paper initially the predictive models are presented for the quantitative assessment of time-dependent damages in RC beams, recognized as loss of mass and cross-sectional area of reinforcing bar, loss of concrete section owing to the peeling of cover concrete, and loss of bond between corroded reinforcement and surrounding cracked concrete. Then these models have been used to present analytical formulations for evaluating time-dependent flexural and shear strengths of corroded RC beams, based on the standard composite mechanics expressions for RC sections. Further by considering variability in the identified basic variables that could affect the time-dependent strengths of corrosion-affected RC beams, the estimation of statistical descriptions for the time-dependent strengths is presented for a typical simply supported RC beam. The statistical descriptions

  19. On a Camassa-Holm type equation with two dependent variables

    Energy Technology Data Exchange (ETDEWEB)

    Falqui, Gregorio [SISSA, Via Beirut 2/4, I-34014 Trieste (Italy)

    2006-01-13

    We consider a generalization of the Camassa-Holm (CH) equation with two dependent variables, called CH2, introduced in a paper by Liu and Zhang (Liu S-Q and Zhang Y 2005 J. Geom. Phys. 54 427-53). We briefly provide an alternative derivation of it based on the theory of Hamiltonian structures on (the dual of) a Lie algebra. The Lie algebra involved here is the same algebra as underlies the NLS hierarchy. We study the structural properties of the hierarchy defined by the CH2 equation within the bi-Hamiltonian theory of integrable PDEs, and provide its Lax representation. Then we explicitly discuss how to construct classes of solutions, both of peakon and of algebro-geometrical type. Finally we sketch the construction of a class of singular solutions, defined by setting to zero one of the two dependent variables.

  20. Stochasticity and Determinism: How Density-Independent and Density-Dependent Processes Affect Population Variability

    OpenAIRE

    Jan Ohlberger; Rogers, Lauren A.; Nils Chr. Stenseth

    2014-01-01

    A persistent debate in population ecology concerns the relative importance of environmental stochasticity and density dependence in determining variability in adult year-class strength, which contributes to future reproduction as well as potential yield in exploited populations. Apart from the strength of the processes, the timing of density regulation may affect how stochastic variation, for instance through climate, translates into changes in adult abundance. In this study, we develop a lif...

  1. Nanostructures study of CNT nanofluids transport with temperature-dependent variable viscosity in a muscular tube

    Science.gov (United States)

    Akbar, Noreen Sher; Abid, Syed Ali; Tripathi, Dharmendra; Mir, Nazir Ahmed

    2017-03-01

    The transport of single-wall carbon nanotube (CNT) nanofluids with temperature-dependent variable viscosity is analyzed by peristaltically driven flow. The main flow problem has been modeled using cylindrical coordinates and flow equations are simplified to ordinary differential equations using long wavelength and low Reynolds' number approximation. Analytical solutions have been obtained for axial velocity, pressure gradient and temperature. Results acquired are discussed graphically for better understanding. It is observed that with an increment in the Grashof number the velocity of the governing fluids starts to decrease significantly and the pressure gradient is higher for pure water as compared to single-walled carbon nanotubes due to low density. As the specific heat is very high for pure water as compared to the multi-wall carbon nanotubes, it raises temperature of the muscles, in the case of pure water, as compared to the multi-walled carbon nanotubes. Furthermore, it is noticed that the trapped bolus starts decreasing in size as the buoyancy forces are dominant as compared to viscous forces. This model may be applicable in biomedical engineering and nanotechnology to design the biomedical devices.

  2. Cataclysmic variables in Globular clusters: First results on the analysis of the MOCCA simulations database

    CERN Document Server

    Belloni, Diogo; Askar, Abbas; Hypki, Arkadiusz

    2016-01-01

    In this first investigation of the MOCCA database with respect to cataclysmic variables, we found that for models with Kroupa initial distributions, considering the standard value of the efficiency of the common-envelope phase adopted in BSE, no single cataclysmic variable was formed only via binary stellar evolution, i. e., in order to form them, strong dynamical interactions have to take place. Our results also indicate that the population of cataclysmic variables in globular clusters are, mainly, in the last stage of their evolution and observational selection effects can change drastically the expected number and properties of observed cataclysmic variables.

  3. Bayesian Techniques for Comparing Time-dependent GRMHD Simulations to Variable Event Horizon Telescope Observations

    Science.gov (United States)

    Kim, Junhan; Marrone, Daniel P.; Chan, Chi-Kwan; Medeiros, Lia; Özel, Feryal; Psaltis, Dimitrios

    2016-12-01

    The Event Horizon Telescope (EHT) is a millimeter-wavelength, very-long-baseline interferometry (VLBI) experiment that is capable of observing black holes with horizon-scale resolution. Early observations have revealed variable horizon-scale emission in the Galactic Center black hole, Sagittarius A* (Sgr A*). Comparing such observations to time-dependent general relativistic magnetohydrodynamic (GRMHD) simulations requires statistical tools that explicitly consider the variability in both the data and the models. We develop here a Bayesian method to compare time-resolved simulation images to variable VLBI data, in order to infer model parameters and perform model comparisons. We use mock EHT data based on GRMHD simulations to explore the robustness of this Bayesian method and contrast it to approaches that do not consider the effects of variability. We find that time-independent models lead to offset values of the inferred parameters with artificially reduced uncertainties. Moreover, neglecting the variability in the data and the models often leads to erroneous model selections. We finally apply our method to the early EHT data on Sgr A*.

  4. Modelling the statistical dependence of rainfall event variables by a trivariate copula function

    Directory of Open Access Journals (Sweden)

    M. Balistrocchi

    2011-01-01

    Full Text Available In many hydrological models, such as those derived by analytical probabilistic methods, the precipitation stochastic process is represented by means of individual storm random variables which are supposed to be independent of each other. However, several proposals were advanced to develop joint probability distributions able to account for the observed statistical dependence. The traditional technique of the multivariate statistics is nevertheless affected by several drawbacks, whose most evident issue is the unavoidable subordination of the dependence structure assessment to the marginal distribution fitting. Conversely, the copula approach can overcome this limitation, by splitting the problem in two distinct items. Furthermore, goodness-of-fit tests were recently made available and a significant improvement in the function selection reliability has been achieved. Herein a trivariate probability distribution of the rainfall event volume, the wet weather duration and the interevent time is proposed and verified by test statistics with regard to three long time series recorded in different Italian climates. The function was developed by applying a mixing technique to bivariate copulas, which were formerly obtained by analyzing the random variables in pairs. A unique probabilistic model seems to be suitable for representing the dependence structure, despite the sensitivity shown by the dependence parameters towards the threshold utilized in the procedure for extracting the independent events. The joint probability function was finally developed by adopting a Weibull model for the marginal distributions.

  5. Size dependent differences in litter consumption of isopods: preliminary results.

    Science.gov (United States)

    Vilisics, Ferenc; Szekeres, Sándor; Hornung, Elisabeth

    2012-01-01

    A series of experiments were applied to test how leaf orientation within microcosms affect consumption rates (Experiment 1), and to discover intra-specific differences in leaf litter consumption (Experiment 2) of the common isopod species Porcellio scaber and Porcellionides pruinosus. A standardised microcosm setup was developed for feeding experiments to maintain standard conditions. A constant amount of freshly fallen black poplar litter was provided to three distinct size class (small, medium, large) of woodlice. We measured litter consumption after a fortnight. We maintained appr. constant isopod biomass for all treatments, and equal densities within each size class. We hypothesized that different size classes differ in their litter consumption, therefore such differences should occur even within populations of the species. We also hypothesized a marked difference in consumption rates for different leaf orientation within microcosms. Our results showed size-specific consumption patterns for Porcellio scaber: small adults showed the highest consumption rates (i.e. litter mass loss / isopod biomass) in high density microcosms, while medium-sized adults of lower densities ate the most litter in containers. Leaf orientation posed no significant effect on litter consumption.

  6. Size dependent differences in litter consumption of isopods: preliminary results

    Directory of Open Access Journals (Sweden)

    Ferenc Vilisics

    2012-03-01

    Full Text Available A series of experiments were applied to test how leaf orientation within microcosms affect consumption rates (Experiment 1, and to discover intra-specific differences in leaf litter consumption (Experiment 2 of the common isopod species Porcellio scaber and Porcellionides pruinosus. A standardised microcosm setup was developed for feeding experiments to maintain standard conditions. A constant amount of freshly fallen black poplar litter was provided to three distinct size class (small, medium, large of woodlice. We measured litter consumption after a fortnight. We maintained appr. constant isopod biomass for all treatments, and equal densities within each size class. We hypothesized that different size classes differ in their litter consumption, therefore such differences should occur even within populations of the species. We also hypothesized a marked difference in consumption rates for different leaf orientation within microcosms. Our results showed size-specific consumption patterns for P. scaber: small adults showed the highest consumption rates (i.e. litter mass loss / isopod biomass in high density microcosms, while medium-sized adults of lower densities ate the most litter in containers. Leaf orientation posed no significant effect on litter consumption.

  7. Anatomy of a population cycle: the role of density dependence and demographic variability on numerical instability and periodicity.

    Science.gov (United States)

    Row, Jeffrey R; Wilson, Paul J; Murray, Dennis L

    2014-07-01

    Determining the causes of cyclic fluctuations in population size is a central tenet in population ecology and provides insights into population regulatory mechanisms. We have a firm understanding of how direct and delayed density dependence affects population stability and cyclic dynamics, but there remains considerable uncertainty in the specific processes contributing to demographic variability and consequent change in cyclic propensity. Spatiotemporal variability in cyclic propensity, including recent attenuation or loss of cyclicity among several temperate populations and the implications of habitat fragmentation and climate change on this pattern, highlights the heightened need to understand processes underlying cyclic variation. Because these stressors can differentially impact survival and productivity and thereby impose variable time delays in density dependence, there is a specific need to elucidate how demographic vital rates interact with the type and action of density dependence to contribute to population stability and cyclic variation. Here, we address this knowledge gap by comparing the stability of time series derived from general and species-specific (Canada lynx: Lynx canadensis; small rodents: Microtus, Lemmus and Clethrionomys spp.) matrix population models, which vary in their demographic rates and the direct action of density dependence. Our results reveal that density dependence acting exclusively on survival as opposed to productivity is destabilizing, suggesting that a shift in the action of population regulation toward reproductive output may decrease cyclic propensity and cycle amplitude. This result was the same whether delayed density dependence was pulsatile and acted on a single time period (e.g. t-1, t-2 or t-3) vs. more constant by affecting a successive range of years (e.g. t-1,…, t-3). Consistent with our general models, reductions in reproductive potential in both the lynx and small rodent systems led to notably large drops in

  8. Bayesian Network Models for Local Dependence among Observable Outcome Variables. Research Report. ETS RR-06-36

    Science.gov (United States)

    Almond, Russell G.; Mulder, Joris; Hemat, Lisa A.; Yan, Duanli

    2006-01-01

    Bayesian network models offer a large degree of flexibility for modeling dependence among observables (item outcome variables) from the same task that may be dependent. This paper explores four design patterns for modeling locally dependent observations from the same task: (1) No context--Ignore dependence among observables; (2) Compensatory…

  9. Distance and Azimuthal Dependence of Ground‐Motion Variability for Unilateral Strike‐Slip Ruptures

    KAUST Repository

    Vyas, Jagdish Chandra

    2016-06-21

    We investigate near‐field ground‐motion variability by computing the seismic wavefield for five kinematic unilateral‐rupture models of the 1992 Mw 7.3 Landers earthquake, eight simplified unilateral‐rupture models based on the Landers event, and a large Mw 7.8 ShakeOut scenario. We include the geometrical fault complexity and consider different 1D velocity–density profiles for the Landers simulations and a 3D heterogeneous Earth structure for the ShakeOut scenario. For the Landers earthquake, the computed waveforms are validated using strong‐motion recordings. We analyze the simulated ground‐motion data set in terms of distance and azimuth dependence of peak ground velocity (PGV). Our simulations reveal that intraevent ground‐motion variability Graphic is higher in close distances to the fault (<20  km) and decreases with increasing distance following a power law. This finding is in stark contrast to constant sigma‐values used in empirical ground‐motion prediction equations. The physical explanation of a large near‐field Graphic is the presence of strong directivity and rupture complexity. High values of Graphic occur in the rupture‐propagation direction, but small values occur in the direction perpendicular to it. We observe that the power‐law decay of Graphic is primarily controlled by slip heterogeneity. In addition, Graphic, as function of azimuth, is sensitive to variations in both rupture speed and slip heterogeneity. The azimuth dependence of the ground‐motion mean μln(PGV) is well described by a Cauchy–Lorentz function that provides a novel empirical quantification to model the spatial dependency of ground motion. Online Material: Figures of slip distributions, residuals to ground‐motion prediction equations (GMPEs), distance and azimuthal dependence, and directivity predictor of ground‐motion variability for different source models.

  10. Variation among Species in the Temperature Dependence of the Reappearance of Variable Fluorescence following Illumination.

    Science.gov (United States)

    Burke, J J

    1990-06-01

    The relationship between the thermal dependence of the reappearance of chlorophyll variable fluorescence following illumination and temperature dependence of the apparent Michaelis constant (K(m)) of NADH hydroxypyruvate reductase for NADH was investigated in cool and warm season plant species. Brancker SF-20 and SF-30 fluorometers were used to evaluate induced fluorescence transients from detached leaves of wheat (Triticum aestivum L. cv TAM-101), cotton (Gossypium hirsutum L. cv Paymaster 145), tomato (Lycopersicon esculentum cv Del Oro), bell pepper (Capsicum annuum L. cv California Wonder), and petunia (Petunia hybrida cv. Red Sail). Following an illumination period at 25 degrees C, the reappearance of variable fluorescence during a dark incubation was determined at 5 degrees C intervals from 15 degrees C to 45 degrees C. Variable fluorescence recovery was normally distributed with the maximum recovery observed at 20 degrees C in wheat, 30 degrees C in cotton, 20 degrees C to 25 degrees C in tomato, 30 to 35 degrees C in bell pepper and 25 degrees C in petunia. Comparison of the thermal response of fluorescence recovery with the temperature sensitivity of the apparent K(m) of hydroxypyruvate reductase for NADH showed that the range of temperatures providing fluorescence recovery corresponded with those temperatures providing the minimum apparent K(m) values (viz. the thermal kinetic window).

  11. Saddlepoint expansions for sums of Markov dependent variables on a continuous state space

    DEFF Research Database (Denmark)

    Jensen, J.L.

    1991-01-01

    here very similar to the classical results for i.i.d. variables. In particular we establish also conditions under which the expansions hold uniformly over the range of the saddlepoint. Expansions are also derived for sums of the form f(X1, X0)+f(X2, X1)+...+f(Xn, Xn-1) although the uniformity result...

  12. Variables predicting elevated portal pressure in alcoholic liver disease. Results of a multivariate analysis

    DEFF Research Database (Denmark)

    Krogsgaard, K; Christensen, E; Gluud, C;

    1987-01-01

    In 46 alcoholic patients the association of wedged-to-free hepatic-vein pressure with other variables (clinical, histologic, hemodynamic, and liver function data) was studied by means of multiple regression analysis, taking the wedged-to-free hepatic-vein pressure as the dependent variable. Four...... variables showed significant independent association with the wedged-to-free hepatic-vein pressure: indocyanine green clearance (p = 0.031), degree of necrosis (p = 0.023), degree of hepatic architectural destruction (graded as: preserved architecture, nodules alternating with preserved architecture......, totally destroyed architecture) (p = 2.3 X 10(-6) and sex (p = 0.0024), male sex being associated with higher wedged-to-free hepatic-vein pressure. The multiple coefficient of determination (R2) was 0.63; thus, 63% of the variation in the wedged-to-free hepatic-vein pressure was 'explained' by variation...

  13. Alaskan soil carbon stocks: spatial variability and dependence on environmental factors

    Directory of Open Access Journals (Sweden)

    U. Mishra

    2012-09-01

    Full Text Available The direction and magnitude of soil organic carbon (SOC changes in response to climate change depend on the spatial and vertical distributions of SOC. We estimated spatially resolved SOC stocks from surface to C horizon, distinguishing active-layer and permafrost-layer stocks, based on geospatial analysis of 472 soil profiles and spatially referenced environmental variables for Alaska. Total Alaska state-wide SOC stock was estimated to be 77 Pg, with 61% in the active-layer, 27% in permafrost, and 12% in non-permafrost soils. Prediction accuracy was highest for the active-layer as demonstrated by highest ratio of performance to deviation (1.5. Large spatial variability was predicted, with whole-profile, active-layer, and permafrost-layer stocks ranging from 1–296 kg C m−2, 2–166 kg m−2, and 0–232 kg m−2, respectively. Temperature and soil wetness were found to be primary controllers of whole-profile, active-layer, and permafrost-layer SOC stocks. Secondary controllers, in order of importance, were found to be land cover type, topographic attributes, and bedrock geology. The observed importance of soil wetness rather than precipitation on SOC stocks implies that the poor representation of high-latitude soil wetness in Earth system models may lead to large uncertainty in predicted SOC stocks under future climate change scenarios. Under strict caveats described in the text and assuming temperature changes from the A1B Intergovernmental Panel on Climate Change emissions scenario, our geospatial model indicates that the equilibrium average 2100 Alaska active-layer depth could deepen by 11 cm, resulting in a thawing of 13 Pg C currently in permafrost. The equilibrium SOC loss associated with this warming would be highest under continuous permafrost (31%, followed by discontinuous (28%, isolated (24.3%, and sporadic (23.6% permafrost areas. Our high-resolution mapping of soil carbon stock reveals the

  14. Category learning in Alzheimer's disease and normal cognitive aging depends on initial experience of feature variability.

    Science.gov (United States)

    Phillips, Jeffrey S; McMillan, Corey T; Smith, Edward E; Grossman, Murray

    2017-04-01

    Semantic category learning is dependent upon several factors, including the nature of the learning task, as well as individual differences in the quality and heterogeneity of exemplars that an individual encounters during learning. We trained healthy older adults (n=39) and individuals with a diagnosis of Alzheimer's disease or Mild Cognitive Impairment (n=44) to recognize instances of a fictitious animal, a "crutter". Each stimulus item contained 10 visual features (e.g., color, tail shape) which took one of two values for each feature (e.g., yellow/red, curly/straight tails). Participants were presented with a series of items (learning phase) and were either told the items belonged to a semantic category (explicit condition) or were told to think about the appearance of the items (implicit condition). Half of participants saw learning items with higher similarity to an unseen prototype (high typicality learning set), and thus lower between-item variability in their constituent features; the other half learned from items with lower typicality (low typicality learning set) and higher between-item feature variability. After the learning phase, participants were presented with test items one at a time that varied in the number of typical features from 0 (antitype) to 10 (prototype). We examined between-subjects factors of learning set (lower or higher typicality), instruction type (explicit or implicit), and group (patients vs. elderly control). Learning in controls was aided by higher learning set typicality: while controls in both learning set groups demonstrated significant learning, those exposed to a high-typicality learning set appeared to develop a prototype that helped guide their category membership judgments. Overall, patients demonstrated more difficulty with category learning than elderly controls. Patients exposed to the higher-typicality learning set were sensitive to the typical features of the category and discriminated between the most and least

  15. Alaskan soil carbon stocks: spatial variability and dependence on environmental factors

    Directory of Open Access Journals (Sweden)

    U. Mishra

    2012-05-01

    Full Text Available The direction and magnitude of soil organic carbon (SOC changes in response to climate change depend on the spatial and vertical distributions of SOC. We estimated spatially-resolved SOC stocks from surface to C horizon, distinguishing active-layer and permafrost-layer stocks, based on geospatial analysis of 472 soil profiles and spatially referenced environmental variables for Alaska. Total Alaska state-wide SOC stock was estimated to be 77 Pg, with 61% in the active-layer, 27% in permafrost, and 12% in non-permafrost soils. Prediction accuracy was highest for the active-layer as demonstrated by highest ratio of performance to deviation (1.5. Large spatial variability was predicted, with whole-profile, active-layer, and permafrost-layer stocks ranging from 1–296 kg C m−2, 2–166 kg m−2, and 0–232 kg m−2, respectively. Temperature and soil wetness were found to be primary controllers of whole-profile, active-layer, and permafrost-layer SOC stocks. Secondary controllers, in order of importance, were: land cover type, topographic attributes, and bedrock geology. The observed importance of soil wetness rather than precipitation on SOC stocks implies that the poor representation of high-latitude soil wetness in Earth System Models may lead to large uncertainty in predicted SOC stocks under future climate change scenarios. Under strict caveats described in the text and assuming temperature changes from the A1B Intergovernmental Panel on Climate Change emissions scenario, our geospatial model indicates that the equilibrium average 2100 Alaska active-layer depth could deepen by 11 cm, resulting in a thawing of 13 Pg C currently in permafrost. The equilibrium SOC loss associated with this warming would be highest under continuous permafrost (31%, followed by discontinuous (28%, isolated (24.3%, and sporadic (23.6% permafrost areas. Our high resolution mapping of soil carbon stock reveals the potential

  16. Degree of multicollinearity and variables involved in linear dependence in additive-dominant models

    Directory of Open Access Journals (Sweden)

    Juliana Petrini

    2012-12-01

    Full Text Available The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567, yearling weight (n=58,124, and scrotal circumference (n=20,371 of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.

  17. Stochasticity and determinism: how density-independent and density-dependent processes affect population variability.

    Science.gov (United States)

    Ohlberger, Jan; Rogers, Lauren A; Stenseth, Nils Chr

    2014-01-01

    A persistent debate in population ecology concerns the relative importance of environmental stochasticity and density dependence in determining variability in adult year-class strength, which contributes to future reproduction as well as potential yield in exploited populations. Apart from the strength of the processes, the timing of density regulation may affect how stochastic variation, for instance through climate, translates into changes in adult abundance. In this study, we develop a life-cycle model for the population dynamics of a large marine fish population, Northeast Arctic cod, to disentangle the effects of density-independent and density-dependent processes on early life-stages, and to quantify the strength of compensatory density dependence in the population. The model incorporates information from scientific surveys and commercial harvest, and dynamically links multiple effects of intrinsic and extrinsic factors on all life-stages, from eggs to spawners. Using a state-space approach we account for observation error and stochasticity in the population dynamics. Our findings highlight the importance of density-dependent survival in juveniles, indicating that this period of the life cycle largely determines the compensatory capacity of the population. Density regulation at the juvenile life-stage dampens the impact of stochastic processes operating earlier in life such as environmental impacts on the production of eggs and climate-dependent survival of larvae. The timing of stochastic versus regulatory processes thus plays a crucial role in determining variability in adult abundance. Quantifying the contribution of environmental stochasticity and compensatory mechanisms in determining population abundance is essential for assessing population responses to climate change and exploitation by humans.

  18. The dependence of J/ψ-nucleon inelastic cross section on the Feynman variable

    Institute of Scientific and Technical Information of China (English)

    DUAN Chun-Gui; LIU Na; MIAO Wen-Dan

    2011-01-01

    By means of two typical sets of nuclear parton distribution functions,meanwhile taking account of the energy loss of the beam proton and the nuclear absorption of the charmonium states traversing the nuclear matter in the uniform framework of the Glauber model,a leading order phenomenological analysis is given in the color evaporation model of the E866 experimental data on J/Ψ production differential cross section ratios RFe/Be(xF).It is shown that the energy loss effect of beam proton on RFe/Be(xF)is more important than the nuclear effects on parton distribution functions in the high Feynman variable xF region.It is found that the J/Ψ-nucleon inelastic cross section depends on the Feynman variable XF and increases linearly with XF in the region xF > 0.2.

  19. Method of frequency dependent correlations: investigating the variability of total solar irradiance

    Science.gov (United States)

    Pelt, J.; Käpylä, M. J.; Olspert, N.

    2017-03-01

    Context. This paper contributes to the field of modeling and hindcasting of the total solar irradiance (TSI) based on different proxy data that extend further back in time than the TSI that is measured from satellites. Aims: We introduce a simple method to analyze persistent frequency-dependent correlations (FDCs) between the time series and use these correlations to hindcast missing historical TSI values. We try to avoid arbitrary choices of the free parameters of the model by computing them using an optimization procedure. The method can be regarded as a general tool for pairs of data sets, where correlating and anticorrelating components can be separated into non-overlapping regions in frequency domain. Methods: Our method is based on low-pass and band-pass filtering with a Gaussian transfer function combined with de-trending and computation of envelope curves. Results: We find a major controversy between the historical proxies and satellite-measured targets: a large variance is detected between the low-frequency parts of targets, while the low-frequency proxy behavior of different measurement series is consistent with high precision. We also show that even though the rotational signal is not strongly manifested in the targets and proxies, it becomes clearly visible in FDC spectrum. A significant part of the variability can be explained by a very simple model consisting of two components: the original proxy describing blanketing by sunspots, and the low-pass-filtered curve describing the overall activity level. The models with the full library of the different building blocks can be applied to hindcasting with a high level of confidence, Rc ≈ 0.90. The usefulness of these models is limited by the major target controversy. Conclusions: The application of the new method to solar data allows us to obtain important insights into the different TSI modeling procedures and their capabilities for hindcasting based on the directly observed time intervals.

  20. Re-examining the ontogeny of the context preexposure facilitation effect in the rat through multiple dependent variables.

    Science.gov (United States)

    Pisano, M V; Ferreras, S; Krapacher, F A; Paglini, G; Arias, C

    2012-07-15

    The capability to acquire context conditioning does not emerge until weaning, at least when the defining features of the context lack explicit and salient olfactory cues. Contextual learning deficits in preweanling rats have been associated with functional immaturity of the dorsal hippocampus. According to recent studies, the so-called context preexposure facilitation effect (CPFE) - a hippocampus-dependent effect - is not observed until postnatal day 23 (PD23). In these studies the footshock intensity employed was higher (1.5 mA) than in adult studies, and context conditioning was inferred from a single behavioral measure (percentage of freezing). The present study examined the CPFE on PD17 and PD23 by analyzing multiple dependent variables, including fecal boli and an ethogram covering the complete behavioral repertoire of the rat. A non-shocked control group was included in the design and two footshock intensities were employed (0.5 and 1.5 mA). Results showed clear evidence of contextual fear conditioning in preweanling and weanling rats, as well as evidence of conditioned fear in non-preexposed rats from both age groups. In some cases, some dependent variables, such as grooming or vertical exploration, were more sensitive than freezing for detecting evidence of memory. Strong fear responses were detected in weanling (but not preweanling) rats, when rats were evaluated in a different context from the one employed at conditioning. These results indicate that preweanling rats are capable of acquiring contextual conditioning, even in a context lacking explicit odor cues, and highlight the importance of multiple dependent variables for analyzing the ontogeny of memory.

  1. The Time Domain Spectroscopic Survey: Variable Object Selection and Anticipated Results

    CERN Document Server

    Morganson, Eric; Anderson, Scott F; Ruan, John J; Myers, Adam D; Eracleous, Michael; Kelly, Brandon; Badenes, Carlos; Banados, Eduardo; Blanton, Michael R; Bershady, Matthew A; Borissova, Jura; Brandt, William Nielsen; Burgett, William S; Chambers, Kenneth; Draper, Peter W; Davenport, James R A; Flewelling, Heather; Garnavich, Peter; Hawley, Suzanne L; Hodapp, Klaus W; Isler, Jedidah C; Kaiser, Nick; Kinemuchi, Karen; Kudritzki, Rolf P; Metcalfe, Nigel; Morgan, Jeffrey S; Paris, Isabelle; Parvizi, Mahmoud; Poleski, Radoslaw; Price, Paul A; Salvato, Mara; Shanks, Tom; Schlafly, Eddie F; Schneider, Donald P; Shen, Yue; Stassun, Keivan; Tonry, John T; Walter, Fabian; Waters, Chris Z

    2015-01-01

    We present the selection algorithm and anticipated results for the Time Domain Spectroscopic Survey (TDSS). TDSS is an SDSS-IV eBOSS subproject that will provide initial identification spectra of approximately 220,000 luminosity-variable objects (variable stars and AGN) across 7,500 square degrees selected from a combination of SDSS and multi-epoch Pan-STARRS1 photometry. TDSS will be the largest spectroscopic survey to explicitly target variable objects, avoiding pre-selection on the basis of colors or detailed modeling of specific variability characteristics. Kernel Density Estimate (KDE) analysis of our target population performed on SDSS Stripe 82 data suggests our target sample will be 95% pure (meaning 95% of objects we select have genuine luminosity variability of a few magnitudes or more). Our final spectroscopic sample will contain roughly 135,000 quasars and 85,000 stellar variables, approximately 4,000 of which will be RR Lyrae stars which may be used as outer Milky Way probes. The variability-sele...

  2. Weighted sums of subexponential random variables and asymptotic dependence between returns on reinsurance equities

    NARCIS (Netherlands)

    J.L. Geluk (Jaap); C.G. de Vries (Casper)

    2004-01-01

    textabstractAsymptotic tail probabilities for bivariate linear combinations of subexponential random variables are given. These results are applied to explain the joint movements of the stocks of reinsurers. Portfolio investment and retrocession practices in the reinsurance industry, for reasons of

  3. Independent Sampling vs Interitem Dependencies in Whole Report Processing: Contributions of Processing Architecture and Variable Attention.

    Science.gov (United States)

    Busey, Thomas A.; Townsend, James T.

    2001-04-01

    All current models of visual whole report processing assume perceptual independence among the displayed items in which the perceptual processing of individual items is not affected by other items in the display. However, models proposed by Townsend (1981, Acta Psychologica 47, 149-173), Shibuya and Bundesen (1988, Journal of Experimental Psychology: Human Perception and Performance 14, 591-600), and Bundesen (1990, Psychological Review 97, 523-547) contain postperceptual buffers that must predict negative dependencies. The perceptual-independence assumption forms what we term the modal model class. A recent example of a model that assumes perceptual independence is the Independent Sampling Model of Loftus, Busey, and Senders (1993, Perception and Psychophysics 54, 535-554). The fundamental independence assumption has only been directly tested once before, where tests revealed no dependencies except those produced by guessing. The present study tests the independence assumption using several different statistics and, contrary to most extant models of whole report, finds significant positive dependence. Poisson models do predict a positive dependence and we develop a succinctly parameterized version, the Weighted Path Poisson Model, which allows the finishing order to be a weighted probabilistic mechanism. However, it does not predict the data quite as well as a new model, the Variable Attention Model, which allows independence within trials (unlike the Poisson models). This model assumes that attention (or, potentially, other aspects such as signal quality) varies widely across trials, thus predicting an overall positive dependence. Intuitions for and against the competing models are discussed. In addition, we show, through mimicking formulae, that models which contain the proper qualitative type of dependence structure can be cast in either serial or parallel form. Copyright 2001 Academic Press.

  4. Timing and Variability of Galactose Metabolic Gene Activation Depend on the Rate of Environmental Change.

    Directory of Open Access Journals (Sweden)

    Truong D Nguyen-Huu

    2015-07-01

    Full Text Available Modulation of gene network activity allows cells to respond to changes in environmental conditions. For example, the galactose utilization network in Saccharomyces cerevisiae is activated by the presence of galactose but repressed by glucose. If both sugars are present, the yeast will first metabolize glucose, depleting it from the extracellular environment. Upon depletion of glucose, the genes encoding galactose metabolic proteins will activate. Here, we show that the rate at which glucose levels are depleted determines the timing and variability of galactose gene activation. Paradoxically, we find that Gal1p, an enzyme needed for galactose metabolism, accumulates more quickly if glucose is depleted slowly rather than taken away quickly. Furthermore, the variability of induction times in individual cells depends non-monotonically on the rate of glucose depletion and exhibits a minimum at intermediate depletion rates. Our mathematical modeling suggests that the dynamics of the metabolic transition from glucose to galactose are responsible for the variability in galactose gene activation. These findings demonstrate that environmental dynamics can determine the phenotypic outcome at both the single-cell and population levels.

  5. Precipitation variability on global pasturelands may affect food security in livestock-dependent regions

    Science.gov (United States)

    Sloat, L.; Gerber, J. S.; Samberg, L. H.; Smith, W. K.; West, P. C.; Herrero, M.; Brendan, P.; Cecile, G.; Katharina, W.; Smith, W. K.

    2016-12-01

    The need to feed an increasing number of people while maintaining biodiversity and ecosystem services is one of the key challenges currently facing humanity. Livestock systems are likely to be a crucial piece of this puzzle, as urbanization and changing diets in much of the world lead to increases in global meat consumption. This predicted increase in global demand for livestock products will challenge the ability of pastures and rangelands to maintain or increase their productivity. The majority of people that depend on animal production for food security do so through grazing and herding on natural rangelands, and these systems make a significant contribution to global production of meat and milk. The vegetation dynamics of natural forage are highly dependent on climate, and subject to disruption with changes in climate and climate variability. Precipitation heterogeneity has been linked to the ecosystem dynamics of grazing lands through impacts on livestock carrying capacity and grassland degradation potential. Additionally, changes in precipitation variability are linked to the increased incidence of extreme events (e.g. droughts, floods) that negatively impact food production and food security. Here, we use the inter-annual coefficient of variation (CV) of precipitation as a metric to assess climate risk on global pastures. Comparisons of global satellite measures of vegetation greenness to climate reveal that the CV of precipitation is negatively related to mean annual NDVI, such that areas with low year-to-year precipitation variability have the highest measures of vegetation greenness, and vice versa. Furthermore, areas with high CV of precipitation support lower livestock densities and produce less meat. A sliding window analysis of changes in CV of precipitation over the last century shows that, overall, precipitation variability is increasing in global pasture areas, although global maps reveal a patchwork of both positive and negative changes. We use

  6. Low risk of development of substance dependence for barbiturates and clobazam prescribed as antiepileptic drugs: results from a questionnaire study.

    Science.gov (United States)

    Uhlmann, Carmen; Fröscher, Walter

    2009-01-01

    There is no systematical research about the topic of dependence on antiepileptic drugs (AED) for patients with epilepsy, despite the fact that barbiturates and benzodiazepines comprise a potential risk of dependence. We hypothesize that there is no psychological substance dependence for patients with epilepsy, possibly because of their outcome expectations. The aim of the study was to examine these patients in terms of substance dependence. One hundred inpatients at the Lake Constance Epilepsy Center were asked about their experiences with AED in terms of dependence in a structured interview. We registered general statements about dependence of AED, markers for substance dependence, and outcome expectations. About 50% of the patients reported withdrawal symptoms and the development of tolerance, but less than 10% noticed loss of control and craving. Withdrawal symptoms and development of tolerance were significantly lower in a group of patients without barbiturates or clobazam versus patients with barbiturates or/and clobazam. There was no significant difference between these two groups in psychological criteria of dependence, that is, loss of control and craving. Outcome expectations of AED were clearly related to the efficacy against seizures, and only to a small amount to psychotropic effects. The study demonstrates that physiological variables of dependence are present more in patients with epilepsy with a permanent intake of barbiturates or clobazam, but psychological variables of dependence are rarely present in epileptic patients, with or without an intake of barbiturates and clobazam. These results confirm our hypothesis that substance dependence is not a major problem in benzodiazepines and barbiturates in patients with epilepsy. Outcome expectations seem to be related mainly to the anticonvulsant and not the psychotropic effect. This might be the reason for the absence of dependence.

  7. First results from the RAO Variable Star Search Program: I. Background, Procedure, and Results from RAO Field 1

    CERN Document Server

    Williams, Michael D

    2011-01-01

    We describe an ongoing variable star search program and present the first reduced results of a search in a 19 square degree (4.4\\circle x 4.4\\circle) field centered on J2000 {\\alpha} = 22:03:24, {\\delta} = +18:54:32. The search was carried out with the Baker-Nunn Patrol Camera located at the Rothney Astrophysical Observatory in the foothills of the Canadian Rockies. A total of 26,271 stars were detected in the field, over a range of about 11-15 (instrumental) magnitudes. Our image processing made use of the IRAF version of the DAOPHOT aperture photometry routine and we used the ANOVA method to search for periodic variations in the light curves. We formally detected periodic variability in 35 stars, that we tentatively classify according to light curve characteristics: 6 EA (Algol), 5 EB ({\\beta} Lyrae), 19 EW (W UMa), and 5 RR (RR Lyrae) stars. Eleven of the detected variable stars have been reported previously in the literature. The eclipsing binary light curves have been analyzed with a package of light cur...

  8. VISTA Variables in the V\\'ia L\\'actea (VVV): Halfway Status and Results

    CERN Document Server

    Hempel, Maren; Dékány, István; Saito, Roberto K; Lucas, Philip W; Emerson, Jim; Ahumada, Andrea V; Aigrain, Suzanne; Alonso, Maria Victoria; Alonso-García, Javier; Amôres, Eduardo B; Angeloni, Rodolfo; Arias, Julia; Bandyopadhyay, Reba; Barbá, Rodolfo H; Barbuy, Beatriz; Baume, Gustavo; Beamin, Juan Carlos; Bedin, Luigi; Bica, Eduardo; Borissova, Jordanka; Bronfman, Leonardo; Carraro, Giovanni; Catelan, Márcio; Clariá, Juan J; Contreras, Carlos; Cross, Nicholas; Davis, Christopher; de Grijs, Richard; Drew, Janet E; Fariña, Cecilia; Feinstein, Carlos; Lajús, Eduardo Fernández; Folkes, Stuart; Gamen, Roberto C; Geisler, Douglas; Gieren, Wolfgang; Goldman, Bertrand; González, Oscar; Gosling, Andrew; Gunthardt, Guillermo; Gurovich, Sebastian; Hambly, Nigel C; Hanson, Margaret; Hoare, Melvin; Irwin, Mike J; Ivanov, Valentin D; Jordán, Andrés; Kerins, Eamonn; Kinemuchi, Karen; Kurtev, Radostin; Longmore, Andy; López-Corredoira, Martin; Maccarone, Tom; Martín, Eduardo; Masetti, Nicola; Mennickent, Ronald E; Merlo, David; Messineo, Maria; Mirabel, I Félix; Monaco, Lorenzo; Bidin, Christian Moni; Morelli, Lorenzo; Padilla, Nelson; Palma, Tali; Parisi, Maria Celeste; Parker, Quentin; Pavani, Daniela; Pietrukowicz, Pawel; Pietrzynski, Grzegorz; Pignata, Giuliano; Rejkuba, Marina; Rojas, Alejandra; Roman-Lopes, Alexandre; Ruiz, Maria Teresa; Sale, Stuart E; Saviane, Ivo; Schreiber, Matthias R; Schröder, Anja C; Sharma, Saurabh; Smith, Michael; Sodré, Laerte; Soto, Mario; Stephens, Andrew W; Tamura, Motohide; Tappert, Claus; Thompson, Mark A; Toledo, Ignacio; Valenti, Elena; Vanzi, Leonardo; Weidmann, Walter; Zoccali, Manuela

    2014-01-01

    The VISTA Variables in the V\\'ia L\\'actea (VVV) survey is one of six public ESO surveys, and is now in its 4th year of observing. Although far from being complete, the VVV survey has already delivered many results, some directly connected to the intended science goals (detection of variables stars, microlensing events, new star clusters), others concerning more exotic objects, e.g. novae. Now, at the end of the fourth observing period, and comprising roughly 50% of the proposed observations, the actual status of the survey, as well some of the results based on the VVV data, are presented.

  9. Altered blood oxygen level-dependent signal variability in chronic post-traumatic stress disorder during symptom provocation

    Directory of Open Access Journals (Sweden)

    Ke J

    2015-07-01

    Full Text Available Jun Ke,1,* Li Zhang,2,* Rongfeng Qi,1,* Qiang Xu,1 Weihui Li,2 Cailan Hou,3 Yuan Zhong,1 Zhiqiang Zhang,1 Zhong He,4 Lingjiang Li,2,5 Guangming Lu11Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, 2Mental Health Institute, the Second Xiangya Hospital, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, 3Guangdong Academy of Medical Science, Guangdong General Hospital, Guangdong Mental Health Center, Guangzhou, 4Department of Radiology of the Second Xiangya Hospital, Central South University, Changsha, 5Shenzhen Kangning Hospital of Guangdong Province, Shenzhen, People’s Republic of China*These authors contributed equally to this workBackground: Recent research suggests that variability in brain signal provides important information about brain function in health and disease. However, it is unknown whether blood oxygen level-dependent (BOLD signal variability is altered in post-traumatic stress disorder (PTSD. We aimed to identify the BOLD signal variability changes of PTSD patients during symptom provocation and compare the brain patterns of BOLD signal variability with those of brain activation.Methods: Twelve PTSD patients and 14 age-matched controls, who all experienced a mining accident, underwent clinical assessment as well as fMRI scanning while viewing trauma-related and neutral pictures. BOLD signal variability and brain activation were respectively examined with standard deviation (SD and general linear model analysis, and compared between the PTSD and control groups. Multiple regression analyses were conducted to explore the association between PTSD symptom severity and these two brain measures across all subjects as well as in the PTSD group.Results: PTSD patients showed increased activation in the middle occipital gyrus compared with controls, and an inverse correlation was found between PTSD

  10. Exact statistical results for binary mixing and reaction in variable density turbulence

    Science.gov (United States)

    Ristorcelli, J. R.

    2017-02-01

    We report a number of rigorous statistical results on binary active scalar mixing in variable density turbulence. The study is motivated by mixing between pure fluids with very different densities and whose density intensity is of order unity. Our primary focus is the derivation of exact mathematical results for mixing in variable density turbulence and we do point out the potential fields of application of the results. A binary one step reaction is invoked to derive a metric to asses the state of mixing. The mean reaction rate in variable density turbulent mixing can be expressed, in closed form, using the first order Favre mean variables and the Reynolds averaged density variance, ⟨ρ2⟩ . We show that the normalized density variance, ⟨ρ2⟩ , reflects the reduction of the reaction due to mixing and is a mix metric. The result is mathematically rigorous. The result is the variable density analog, the normalized mass fraction variance ⟨c2⟩ used in constant density turbulent mixing. As a consequence, we demonstrate that use of the analogous normalized Favre variance of the mass fraction, c″ ⁣2˜ , as a mix metric is not theoretically justified in variable density turbulence. We additionally derive expressions relating various second order moments of the mass fraction, specific volume, and density fields. The central role of the density specific volume covariance ⟨ρ v ⟩ is highlighted; it is a key quantity with considerable dynamical significance linking various second order statistics. For laboratory experiments, we have developed exact relations between the Reynolds scalar variance ⟨c2⟩ its Favre analog c″ ⁣2˜ , and various second moments including ⟨ρ v ⟩ . For moment closure models that evolve ⟨ρ v ⟩ and not ⟨ρ2⟩ , we provide a novel expression for ⟨ρ2⟩ in terms of a rational function of ⟨ρ v ⟩ that avoids recourse to Taylor series methods (which do not converge for large density differences). We have derived

  11. Heart rate variability biofeedback in patients with alcohol dependence: a randomized controlled study

    Directory of Open Access Journals (Sweden)

    Penzlin AI

    2015-10-01

    Full Text Available Ana Isabel Penzlin,1 Timo Siepmann,2 Ben Min-Woo Illigens,3 Kerstin Weidner,4 Martin Siepmann4 1Institute of Clinical Pharmacology, 2Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Saxony, Germany; 3Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; 4Department of Psychotherapy and Psychosomatic Medicine, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Saxony, Germany Background and objective: In patients with alcohol dependence, ethyl-toxic damage of vasomotor and cardiac autonomic nerve fibers leads to autonomic imbalance with neurovascular and cardiac dysfunction, the latter resulting in reduced heart rate variability (HRV. Autonomic imbalance is linked to increased craving and cardiovascular mortality. In this study, we sought to assess the effects of HRV biofeedback training on HRV, vasomotor function, craving, and anxiety. Methods: We conducted a randomized controlled study in 48 patients (14 females, ages 25–59 years undergoing inpatient rehabilitation treatment. In the treatment group, patients (n=24 attended six sessions of HRV biofeedback over 2 weeks in addition to standard rehabilitative care, whereas, in the control group, subjects received standard care only. Psychometric testing for craving (Obsessive Compulsive Drinking Scale, anxiety (Symptom Checklist-90-Revised, HRV assessment using coefficient of variation of R-R intervals (CVNN analysis, and vasomotor function assessment using laser Doppler flowmetry were performed at baseline, immediately after completion of treatment or control period, and 3 and 6 weeks afterward (follow-ups 1 and 2. Results: Psychometric testing showed decreased craving in the biofeedback group immediately postintervention (OCDS scores: 8.6±7.9 post-biofeedback versus 13.7±11.0 baseline [mean ± standard deviation], P<0.05, whereas craving was unchanged at

  12. High interindividual variability in dose-dependent reduction in speed of movement after exposing C. elegans to shock waves.

    Science.gov (United States)

    Angstman, Nicholas B; Kiessling, Maren C; Frank, Hans-Georg; Schmitz, Christoph

    2015-01-01

    In blast-related mild traumatic brain injury (br-mTBI) little is known about the connections between initial trauma and expression of individual clinical symptoms. Partly due to limitations of current in vitro and in vivo models of br-mTBI, reliable prediction of individual short- and long-term symptoms based on known blast input has not yet been possible. Here we demonstrate a dose-dependent effect of shock wave exposure on C. elegans using shock waves that share physical characteristics with those hypothesized to induce br-mTBI in humans. Increased exposure to shock waves resulted in decreased mean speed of movement while increasing the proportion of worms rendered paralyzed. Recovery of these two behavioral symptoms was observed during increasing post-traumatic waiting periods. Although effects were observed on a population-wide basis, large interindividual variability was present between organisms exposed to the same highly controlled conditions. Reduction of cavitation by exposing worms to shock waves in polyvinyl alcohol resulted in reduced effect, implicating primary blast effects as damaging components in shock wave induced trauma. Growing worms on NGM agar plates led to the same general results in initial shock wave effect in a standard medium, namely dose-dependence and high interindividual variability, as raising worms in liquid cultures. Taken together, these data indicate that reliable prediction of individual clinical symptoms based on known blast input as well as drawing conclusions on blast input from individual clinical symptoms is not feasible in br-mTBI.

  13. Do drug treatment variables predict cognitive performance in multidrug-treated opioid-dependent patients? A regression analysis study

    Directory of Open Access Journals (Sweden)

    Rapeli Pekka

    2012-11-01

    Full Text Available Abstract Background Cognitive deficits and multiple psychoactive drug regimens are both common in patients treated for opioid-dependence. Therefore, we examined whether the cognitive performance of patients in opioid-substitution treatment (OST is associated with their drug treatment variables. Methods Opioid-dependent patients (N = 104 who were treated either with buprenorphine or methadone (n = 52 in both groups were given attention, working memory, verbal, and visual memory tests after they had been a minimum of six months in treatment. Group-wise results were analysed by analysis of variance. Predictors of cognitive performance were examined by hierarchical regression analysis. Results Buprenorphine-treated patients performed statistically significantly better in a simple reaction time test than methadone-treated ones. No other significant differences between groups in cognitive performance were found. In each OST drug group, approximately 10% of the attention performance could be predicted by drug treatment variables. Use of benzodiazepine medication predicted about 10% of performance variance in working memory. Treatment with more than one other psychoactive drug (than opioid or BZD and frequent substance abuse during the past month predicted about 20% of verbal memory performance. Conclusions Although this study does not prove a causal relationship between multiple prescription drug use and poor cognitive functioning, the results are relevant for psychosocial recovery, vocational rehabilitation, and psychological treatment of OST patients. Especially for patients with BZD treatment, other treatment options should be actively sought.

  14. Cast microstructure of Inconel 713C and its dependence on solidification variables

    Energy Technology Data Exchange (ETDEWEB)

    Bhambri, A.K.; Kattamis, T.Z.; Morral, J.E.

    1975-03-01

    The dependence of cast microstructure of Inconel 713C on solidification variables was investigated over a wide range of local cooling rates, epsilon, and thermal gradients in the liquid at the solid-liquid interface, G. The shape of MC carbide particles was found to depend greatly on: 1) the G/R ratio at the solid-liquid interface, where R is growth rate, through the effect of this ratio on the solid phase, ..gamma../sub g/, growth morphology. Under planar front growth conditions the carbide particles were octahedral, under cellular growth conditions they were plate-like, elongated along the cellular growth direction, and under dendritic growth conditions they were irregularly shaped; 2) the local cooling rate, epsilon, when ..gamma.. was dendritic, with a transition from octahedral to dendritic with increasing epsilon. The size of MC carbide particles was found to be controlled by coarsening and to become finer with increasing epsilon. In this alloy the composition of the MC carbide was established as (Nb/sub 0/./sub 63/Ti/sub 0/./sub 31/M0/sub 0/./sub 06/)C and was practically independent of local cooling rate. Other observations were that the precipitation of ..gamma.., d the formation of nonequilibrium eutectics, such as MC-..gamma.., ..gamma..-..gamma..' or MC-..gamma..-..gamma..' were suppressed at splat-cooling rates. Also, microsegregation of all alloying elements with the exception of aluminum was normal, with concentration increasing from the dendrite center-line to the dendrite arm boundary. Aluminum behaved in the opposite manner. Within the cooling rate range used herein, this variable had only a slight effect on microsegregation.

  15. Time-dependent reliability of corrosion-affected RC beams. Part 3: Effect of corrosion initiation time and its variability on time-dependent failure probability

    Energy Technology Data Exchange (ETDEWEB)

    Bhargava, Kapilesh, E-mail: kapil_66@barc.gov.i [Architecture and Civil Engineering Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Mori, Yasuhiro [Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8603 (Japan); Ghosh, A.K. [Reactor Safety Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India)

    2011-05-15

    This paper forms the third part of a study which addresses time-dependent reliability analyses of reinforced concrete (RC) beams affected by reinforcement corrosion. Parts 1 and 2 of the reliability study are presented in companion papers. Part 1 of the reliability study presents evaluation of probabilistic descriptions for time-dependent strengths of a typical simply supported corrosion-affected RC beam. These probabilistic descriptions, i.e., mean and coefficient of variation (c.o.v.) for the time-dependent strengths are presented for two limit states: (a) flexural failure; and (b) shear failure. Part 2 of the reliability study presents evaluation of time-dependent failure probability for the considered RC beam by utilizing the information on probabilistic descriptions for time-dependent strengths available in Part 1. Evaluation of time-dependent failure probability considering the variability in time-dependent strengths and/or time-dependent degradation functions is also presented. This paper investigates the effects of time to corrosion initiation and its variability on failure probability of the same RC beam presented in companion papers. By considering variability in the identified variables that could affect the expected time of first corrosion, simple estimations are presented for mean time to corrosion initiation and variability associated with time to corrosion initiation. Evaluation of time-dependent failure probability for the beam is presented by considering estimated probabilistic descriptions, i.e., mean and c.o.v. for time to corrosion initiation. Parametric analyses show that failure probability for the beam is sensitive to the mode of strength degradation and time to corrosion initiation.

  16. THE DIFFERENCES IN MORAL, GROUP IDENTITY AND THE PERCON’S VARIABILITY DEPENDING ON THE EDUCATION

    Directory of Open Access Journals (Sweden)

    Irina Aleksandrobna Kolinichenko

    2017-06-01

    Results. The results of the study have revealed the dominance of all specified assessment parameters in the group of test subjects with incomplete higher education: higher level of moral development in all dilemmas (the opposition of life values (compassion and following the law, self-interest – the interests of the city (law, business (benefit and law, personal interests (career and the freedom of another person, except for the dilemma of the opposition between the interests of a majority and a single person. The differences have also been revealed between the two groups of test subjects according to the group identity, group variability, the desirability of the common categories of identity.

  17. Variable Viscosity Effects on Time Dependent Magnetic Nanofluid Flow past a Stretchable Rotating Plate

    Directory of Open Access Journals (Sweden)

    Ram Paras

    2016-01-01

    Full Text Available An attempt has been made to describe the effects of geothermal viscosity with viscous dissipation on the three dimensional time dependent boundary layer flow of magnetic nanofluids due to a stretchable rotating plate in the presence of a porous medium. The modelled governing time dependent equations are transformed a from boundary value problem to an initial value problem, and thereafter solved by a fourth order Runge-Kutta method in MATLAB with a shooting technique for the initial guess. The influences of mixed temperature, depth dependent viscosity, and the rotation strength parameter on the flow field and temperature field generated on the plate surface are investigated. The derived results show direct impact in the problems of heat transfer in high speed computer disks (Herrero et al. [1] and turbine rotor systems (Owen and Rogers [2].

  18. Near-infrared thermal emission from near-Earth asteroids: Aspect-dependent variability

    CERN Document Server

    Moskovitz, Nicholas A; DeMeo, Francesca E; Binzel, Richard P; Endicott, Thomas; Yang, Bin; Howell, Ellen S; Vervack, Ronald J; Fernandez, Yanga R

    2016-01-01

    Here we explore a technique for constraining physical properties of near-Earth asteroids (NEAs) based on variability in thermal emission as a function of viewing aspect. We present case studies of the low albedo, near-Earth asteroids (285263) 1998 QE2 and (175706) 1996 FG3. The Near-Earth Asteroid Thermal Model (NEATM) is used to fit signatures of thermal emission in near-infrared (0.8 - 2.5 micron) spectral data. This analysis represents a systematic study of thermal variability in the near-IR as a function of phase angle. The observations of QE2 imply that carefully timed observations from multiple viewing geometries can be used to constrain physical properties like retrograde versus prograde pole orientation and thermal inertia. The FG3 results are more ambiguous with detected thermal variability possibly due to systematic issues with NEATM, an unexpected prograde rotation state, or a surface that is spectrally and thermally heterogenous. This study highlights the potential diagnostic importance of high ph...

  19. Time dependent simulations of multiwavelength variability of the blazar Mrk 421 with a Monte Carlo multi-zone code

    CERN Document Server

    Chen, Xuhui; Liang, Edison; Boettcher, Markus

    2011-01-01

    (abridged) We present a new time-dependent multi-zone radiative transfer code and its application to study the SSC emission of Mrk 421. The code couples Fokker-Planck and Monte Carlo methods, in a 2D geometry. For the first time all the light travel time effects (LCTE) are fully considered, along with a proper treatment of Compton cooling, which depends on them. We study a set of simple scenarios where the variability is produced by injection of relativistic electrons as a `shock front' crosses the emission region. We consider emission from two components, with the second one either being pre-existing and co-spatial and participating in the evolution of the active region, or spatially separated and independent, only diluting the observed variability. Temporal and spectral results of the simulation are compared to the multiwavelength observations of Mrk 421 in March 2001. We find parameters that can adequately fit the observed SEDs and multiwavelength light curves and correlations. There remain however a few o...

  20. Temperature and field-dependent transport measurements in continuously tunable tantalum oxide memristors expose the dominant state variable

    Science.gov (United States)

    Graves, Catherine E.; Dávila, Noraica; Merced-Grafals, Emmanuelle J.; Lam, Si-Ty; Strachan, John Paul; Williams, R. Stanley

    2017-03-01

    Applications of memristor devices are quickly moving beyond computer memory to areas of analog and neuromorphic computation. These applications require the design of devices with different characteristics from binary memory, such as a large tunable range of conductance. A complete understanding of the conduction mechanisms and their corresponding state variable(s) is crucial for optimizing performance and designs in these applications. Here we present measurements of low bias I-V characteristics of 6 states in a Ta/ tantalum-oxide (TaOx)/Pt memristor spanning over 2 orders of magnitude in conductance and temperatures from 100 K to 500 K. Our measurements show that the 300 K device conduction is dominated by a temperature-insensitive current that varies with non-volatile memristor state, with an additional leakage contribution from a thermally-activated current channel that is nearly independent of the memristor state. We interpret these results with a parallel conduction model of Mott hopping and Schottky emission channels, fitting the voltage and temperature dependent experimental data for all memristor states with only two free parameters. The memristor conductance is linearly correlated with N, the density of electrons near EF participating in the Mott hopping conduction, revealing N to be the dominant state variable for low bias conduction in this system. Finally, we show that the Mott hopping sites can be ascribed to oxygen vacancies, where the local oxygen vacancy density responsible for critical hopping pathways controls the memristor conductance.

  1. First Results from MASIV: The Micro-Arcsecond Scintillation-Induced Variability Survey

    CERN Document Server

    Lovell, J; Bignall, H E; Kedziora-Chudczer, L L; MacQuart, J P; Rickett, B; Tzioumis, A K

    2003-01-01

    We are undertaking a large-scale, Micro-Arcsecond Scintillation-Induced Variability (MASIV) survey of the northern sky, Dec > 0 deg, at 4.9 GHz with the VLA. Our objective is to construct a sample of 100 to 150 scintillating extragalactic sources with which to examine both the microarcsecond structure and the parent populations of these sources, and to probe the turbulent interstellar medium responsible for the scintillation. We report on our first epoch of observations which revealed variability on timescales ranging from hours to days in 85 of 710 compact flat-spectrum sources. The number of highly variable sources, those with RMS flux density variations greater than 4% of the mean, increases with decreasing source flux density but rapid, large amplitude variables such as J1819+3845 are very rare. When compared with a model for the scintillation due to irregularities in a 500 pc thick electron layer, our preliminary results indicate maximum brightness temperatures ~10E+12 K, similar to those obtained from V...

  2. Dependence of P-wave dispersion on mean arterial pressure as an independent hemodynamic variable in school children

    Directory of Open Access Journals (Sweden)

    Elibet Chávez González

    2013-09-01

    Full Text Available Introduction:The relationship between diastolic dysfunction and P-wave dispersion (PWD in the electrocardiogram has been studied for some time. In this regard, echocardiography is emerging as a diagnostic tool to improve risk stratification for mild hypertension.Objective:To determine the dependence of PWD on the electrocardiogram and on echocardiographic variables in a pediatric population.Methods: Five hundred and fifteen children from three elementary schools were studiedfrom a total of 565 children. Those whose parents did not want them to take part in the study, as well as those with known congenital diseases, were excluded. Tests including 12-lead surface ECGs and 4 blood pressure (BP measurements were performed. Maximum and minimum P-values were measured, and the PWD on the electrocardiogram was calculated. Echocardiography for structural measurements and the pulsed Doppler of mitral flow were also performed.Results: A significant correlation in statistical variables was found between PWD and mean BP for pre-hypertensive and hypertensive children, i.e., r= 0.32, p <0.01 and r= 0.33, p <0.01, respectively. There was a significant correlation found between PWD and the left atrial area (r= 0.45 and p <0.01.Conclusions: We highlight the dependency between PWD, the electrocardiogram and  mean  blood pressure. We also draw attention to the dependence of PWD on the left atrial area.  This result provides an explanation for earlier changes in atrial electrophysiological and hemodynamic characteristics in pediatric patients.

  3. A numerical study of comparison of two one-state-variable, rate- and state-dependent friction evolution laws

    Institute of Scientific and Technical Information of China (English)

    Jeen-Hwa Wang

    2009-01-01

    The two one-state-variable, rate- and state-dependent friction laws, i.e., the slip and slowness laws, are compared on the basis of dynamical behavior of a one-degree-of-freedom spring-slider model through numerical simulations. Results show that two (normalized) model parameters, i.e., △(the normalized characteristic slip distance) and β-α (the difference in two normalized parameters of friction laws), control the solutions. From given values of △, β, and α, for the slowness laws, the solution exists and the unique non-zero fixed point is stable when △>(β-α), yet not when △<β-α). For the slip law, the solution exists for large ranges of model parameters and the number and stability of the non-zero fixed points change from one case to another. Results suggest that the slip law is more appropriate for controlling earthquake dynamics than the slowness law.

  4. Metallurgical coke quality depending on the variability of properties of coking coal mixes components

    Energy Technology Data Exchange (ETDEWEB)

    M. Kaloc; S. Bartusek; S. Czudek [VSB-TU Ostrava (Czech Republic)

    2005-07-01

    The main sources for this report are the experiences acquired by the long lasting practice of the coking coal mixes preparing and tuning them in accordance with the variable qualitative properties of the coals mined in the coalfields of the OKD Company Ostrava. The systematic database, made by summarizing the values of measured indexes, became a very useful instrument for the coal mixes composing with regard on the two today very important points of view, namely: Contemporary presence and the long lasting availability of the definite coal type from any local source. Price basis influencing strongly the economics of the coke production. The method of prognostic estimating of the metallurgical coke quality dependence on the coking mixes composition, developed some time ago by authors of presented paper, was published in the Cokemaking International Vol. 13, 2/2001 (Czudek S. and al.: Simulation of Carbonization Process under Laboratory Conditions). The original procedure was newly accomplished by implementing a special method of the multi criteria evaluation of the definite coal components. New method is based on special processing of the technologic significant qualitative properties of the mined coal brands enabling deeply estimate the impacts of their application in metallurgical coke production. The importance of this evaluating system exceeds largely the well known method that is incorporated in the international coal classification. The main advantage of the new method is the fully respecting of the specialties marking the geographic different coalfields. (Abstract only)

  5. Satellite derived precipitation and freshwater flux variability and its dependence on the North Atlantic Oscillation

    Science.gov (United States)

    Andersson, Axel; Bakan, Stephan; Graßl, Hartmut

    2010-08-01

    The variability of satellite retrieved precipitation and freshwater flux from the `Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data' (HOAPS) is assessed with special emphasis on the `North Atlantic Oscillation' (NAO). To cover also land areas, a novel combination of the satellite derived precipitation climatology with the rain gauge based `Full Data Reanalysis Product Version 4', of the `Global Precipitation Climatology Centre' (GPCC) is used. This yields unique high-resolution, quasi-global precipitation fields compiled from two independent data sources. Over the ocean, the response of the freshwater balance and the related parameters to the NAO is investigated for the first time by using a purely satellite based data set. A strong dependence of precipitation patterns to the state of the NAO is found. On synoptic scale this is in accordance with earlier findings by other satellite based and reanalysis products. Furthermore, the consistency of the combined HOAPS-3/GPCC data set allows also detailed regional analyses of precipitation patterns. The response of HOAPS-3 freshwater flux to the NAO is dominated by precipitation at mid and high latitudes, while for the subtropical regions the feedback of the evaporation is stronger.

  6. A classification of substance-dependent men on temperament and severity variables.

    Science.gov (United States)

    Henderson, Melinda J; Galen, Luke W

    2003-06-01

    This study examined the validity of classifying substance abusers based on temperament and dependence severity, and expanded the scope of typology differences to proximal determinants of use (e.g., expectancies, motives). Patients were interviewed about substance use, depression, and family history of alcohol and drug abuse. Self-report instruments measuring temperament, expectancies, and motives were completed. Participants were 147 male veterans admitted to inpatient substance abuse treatment at a U.S. Department of Veterans Affairs medical center. Cluster analysis identified four types of users with two high substance problem severity and two low substance problem severity groups. Two, high problem severity, early onset groups differed only on the cluster variable of negative affectivity (NA), but showed differences on antisocial personality characteristics, hypochondriasis, and coping motives for alcohol. The two low problem severity groups were distinguished by age of onset and positive affectivity (PA). The late onset, low PA group had a higher incidence of depression, a greater tendency to use substances in solitary contexts, and lower enhancement motives for alcohol compared to the early onset, high PA cluster. The four-cluster solution yielded more distinctions on external criteria than the two-cluster solution. Such temperament variation within both high and low severity substance abusers may be important for treatment planning.

  7. Near-infrared thermal emission from near-Earth asteroids: Aspect-dependent variability

    Science.gov (United States)

    Moskovitz, Nicholas A.; Polishook, David; DeMeo, Francesca E.; Binzel, Richard P.; Endicott, Thomas; Yang, Bin; Howell, Ellen S.; Vervack, , Ronald J.; Fernández, Yanga R.

    2017-03-01

    Here we explore a technique for constraining physical properties of near-Earth asteroids (NEAs) based on variability in thermal emission as a function of viewing aspect. We present case studies of the low albedo, near-Earth asteroids (285263) 1998 QE2 and (175706) 1996 FG3. The Near-Earth Asteroid Thermal Model (NEATM) is used to fit signatures of thermal emission in near-infrared (0.8 - 2.5 μm) spectral data. This analysis represents a systematic study of thermal variability in the near-IR as a function of phase angle. The observations of QE2 imply that carefully timed observations from multiple viewing geometries can be used to constrain physical properties like retrograde versus prograde pole orientation and thermal inertia. The FG3 results are more ambiguous with detected thermal variability possibly due to systematic issues with NEATM, an unexpected prograde rotation state, or a surface that is spectrally and thermally heterogenous. This study highlights the potential diagnostic importance of high phase angle thermal measurements on both sides of opposition. We find that the NEATM thermal beaming parameters derived from our near-IR data tend to be of order10's of percent higher than parameters from ensemble analyses of longer wavelength data sets. However, a systematic comparison of NEATM applied to data in different wavelength regimes is needed to understand whether this offset is simply a reflection of small number statistics or an intrinsic limitation of NEATM when applied to near-IR data. With the small sample presented here, it remains unclear whether NEATM modeling at near-IR wavelengths can robustly determine physical properties like pole orientation and thermal inertia.

  8. Demographic models reveal the shape of density dependence for a specialist insect herbivore on variable host plants.

    Science.gov (United States)

    Miller, Tom E X

    2007-07-01

    1. It is widely accepted that density-dependent processes play an important role in most natural populations. However, persistent challenges in our understanding of density-dependent population dynamics include evaluating the shape of the relationship between density and demographic rates (linear, concave, convex), and identifying extrinsic factors that can mediate this relationship. 2. I studied the population dynamics of the cactus bug Narnia pallidicornis on host plants (Opuntia imbricata) that varied naturally in relative reproductive effort (RRE, the proportion of meristems allocated to reproduction), an important plant quality trait. I manipulated per-plant cactus bug densities, quantified subsequent dynamics, and fit stage-structured models to the experimental data to ask if and how density influences demographic parameters. 3. In the field experiment, I found that populations with variable starting densities quickly converged upon similar growth trajectories. In the model-fitting analyses, the data strongly supported a model that defined the juvenile cactus bug retention parameter (joint probability of surviving and not dispersing) as a nonlinear decreasing function of density. The estimated shape of this relationship shifted from concave to convex with increasing host-plant RRE. 4. The results demonstrate that host-plant traits are critical sources of variation in the strength and shape of density dependence in insects, and highlight the utility of integrated experimental-theoretical approaches for identifying processes underlying patterns of change in natural populations.

  9. High interindividual variability in dose-dependent reduction in speed of movement after exposing C. elegans to shock waves

    Directory of Open Access Journals (Sweden)

    Nicholas Baker Angstman

    2015-02-01

    Full Text Available In blast-related mild traumatic brain injury (br-mTBI little is known about the connections between initial trauma and expression of individual clinical symptoms. Partly due to limitations of current in vitro and in vivo models of br-mTBI, reliable prediction of individual short- and long-term symptoms based on known blast input has not yet been possible. Here we demonstrate a dose-dependent effect of shock wave exposure on C. elegans using shock waves that share physical characteristics with those hypothesized to induce br-mTBI in humans. Increased exposure to shock waves resulted in decreased mean speed of movement while increasing the proportion of worms rendered paralyzed. Recovery of these two behavioral symptoms was observed during increasing post-traumatic waiting periods. Although effects were observed on a population-wide basis, large interindividual variability was present between organisms exposed to the same highly controlled conditions. Reduction of cavitation by exposing worms to shock waves in polyvinyl alcohol resulted in reduced effect, implicating primary blast effects as damaging components in shock wave induced trauma. Growing worms on NGM agar plates led to the same general results in initial shock wave effect in a standard medium, namely dose-dependence and high interindividual variability, as raising worms in liquid cultures. Taken together, these data indicate that reliable prediction of individual clinical symptoms based on known blast input as well as drawing conclusions on blast input from individual clinical symptoms is not feasible in br-mTBI.

  10. A functional limit theorem for partial sums of dependent random variables with infinite variance

    CERN Document Server

    Basrak, Bojan; Segers, Johan

    2010-01-01

    Under an appropriate regular variation condition, the affinely normalized partial sums of a sequence of independent and identically distributed random variables converges weakly to a non-Gaussian stable random variable. A functional version of this is known to be true as well, the limit process being a stable L\\'evy process. The main result in the paper is that for a stationary, regularly varying sequence for which clusters of high-threshold excesses can be broken down into asymptotically independent blocks, the properly centered partial sum process still converges to a stable L\\'evy process. Due to clustering, the L\\'evy triple of the limit process can be different from the one in the independent case. The convergence takes place in the space of c\\`adl\\`ag functions endowed with Skorohod's $M_1$ topology, the more usual $J_1$ topology being inappropriate as the partial sum processes may exhibit rapid successions of jumps within temporal clusters of large values, collapsing in the limit to a single jump. The ...

  11. VARIABLE STEP-SIZE IMPLICIT-EXPLICIT LINEAR MULTISTEP METHODS FOR TIME-DEPENDENT PARTIAL DIFFERENTIAL EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    Dong Wang; Steven J. Ruuth

    2008-01-01

    Implicit-explicit (IMEX) linear multistep methods are popular techniques for solving partial differential equations (PDEs) with terms of different types. While fixed time-step versions of such schemes have been developed and studied, implicit-explicit schemes also naturally arise in general situations where the temporal smoothness of the solution changes. In this paper we consider easily implementable variable step-size implicit-explicit (VSIMEX) linear multistep methods for time-dependent PDEs. Families of order-p, p-step VSIMEX schemes are constructed and analyzed, where p ranges from 1 to 4. The corresponding schemes are simple to implement and have the property that they reduce to the classical IMEX schemes whenever constant time step-sizes are imposed. The methods are validated on the Burgers' equation. These results demonstrate that by varying the time step-size, VSIMEX methods can outperform their fixed time step counterparts while still maintaining good numerical behavior.

  12. Preliminary experimental results on studying possibility of variable mass liner (VML) formation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The main objective of the present experiment was to study the formation process and initial stage of acceleration of a variable-mass plasma liner (VML). The method is based on magnetic acceleration of a liner with the mass reduced during such acceleration. The experiment was carried out on February 16 at VNIIEF. This report describes the results of measurements obtained in the experiment and preliminary analysis of the results characterizing operation of the test facility main units: helical EMG; 5-module disk EMG 400 mm in diameter (DEMG); ponderomotive unit (PU) with a cylindric condensed liner and a special tooth-cutoff. The first part of the report presents measurement results obtained on the VNIIEF`s diagnostic equipment that are compared with those obtained by American specialists on their diagnostic equipment. Information submitted by American specialists is included in part 2 of this report. The second part of the report presents preliminary computational-theoretic analysis of the main measured results describing operation of DEMG TL system in the experiment; experimental data are compared with theoretical ones obtained before and after the experiment. But more emphasis is placed on the data preliminary analysis indicating that in the experiment a variable mass liner is formed (VML or plasma bubble).

  13. Radial dependence of line profile variability in seven O9--B0.5 stars

    CERN Document Server

    Martins, F; Hillier, D J; Donati, J -F; Bouret, J -C

    2014-01-01

    Massive stars show a variety of spectral variability: presence of discrete absorption components in UV P-Cygni profiles, optical line profile variability, X-ray variability, radial velocity modulations. Our goal is to study the spectral variability of single OB stars to better understand the relation between photospheric and wind variability. For that, we rely on high spectral resolution, high signal-to-noise ratio optical spectra collected with the spectrograph NARVAL on the Telescope Bernard Lyot at Pic du Midi. We investigate the variability of twelve spectral lines by means of the Temporal Variance Spectrum (TVS). The selected lines probe the radial structure of the atmosphere, from the photosphere to the outer wind. We also perform a spectroscopic analysis with atmosphere models to derive the stellar and wind properties, and to constrain the formation region of the selected lines. We show that variability is observed in the wind lines of all bright giants and supergiants, on a daily timescale. Lines form...

  14. Variable conductance heat pipe technology. [research project resulting in heat pipe experiment on OAO-3 satellite

    Science.gov (United States)

    Anderson, W. T.; Edwards, D. K.; Eninger, J. E.; Marcus, B. D.

    1974-01-01

    A research and development program in variable conductance heat pipe technology is reported. The project involved: (1) theoretical and/or experimental studies in hydrostatics, (2) hydrodynamics, (3) heat transfer into and out of the pipe, (4) fluid selection, and (5) materials compatibility. The development, fabrication, and test of the space hardware resulted in a successful flight of the heat pipe experiment on the OAO-3 satellite. A summary of the program is provided and a guide to the location of publications on the project is included.

  15. Using rain-on-snow events to evaluate the quality of bias correction to represent complex inter-variable dependencies

    Science.gov (United States)

    Rössler, Ole; Bosshard, Thomas; Weingartner, Rolf

    2016-04-01

    A key issue for adaptation planning is the information of projections about changes of extremes. Climate projections of meteorological extremes and their downscaling are a challenge on their own. Yet - at least in hydrology - meteorological extremes are not necessarily hydrological extremes. These can also result from a sequence of days with only moderate meteorological conditions, too. This sequences are called "storylines". In climate change impact assess studies it is relevant to know, whether these meteorological storylines are represented in regional climate models, and how well can bias correction preserve or improve the representation. One storyline leading to hydrological extremes are rain-on-snow events, and more specifically rain-on-snowfall events. These events challenge the regional climate model and the bias correction in terms of representing absolute values and inter-variable dependences. This study makes use of the rain-on-snow-storylines to evaluate the performance of regional climate models and a bias correction method in reproducing complex inter-variable dependencies. At first, we applied a hydrological model to a mesoscale catchment in Switzerland that is known to be effected by rain-on-snow events. At second, the ERA-Interim driven regional climate model RCA4.5 - developed at SMHI - with a spatial resolution of 0.11 * 0.11 degree was used to drive the hydrological model. At third, bias-correction of the RCM was done applying the distribution based scaling (DBS) bias-correction method (Yang et al., 2010) developed at the SMHI. The bias-corrected data then also served as driving input data to the hydrological model. Based on the simulated runoff, as well as simulated precipitation, temperature, and snow pack data, an algorithm to detect rain-on-snow events was applied. Finally, the presence or absents of rain-on-snow events for the three different climate input data, ERA.RCA4.5, DBS corrected ERA.RC4 and observed climate, are evaluated within

  16. Disaggregating measurement uncertainty from population variability and Bayesian treatment of uncensored results.

    Science.gov (United States)

    Strom, Daniel J; Joyce, Kevin E; MacLellan, Jay A; Watson, David J; Lynch, Timothy P; Antonio, Cheryl L; Birchall, Alan; Anderson, Kevin K; Zharov, Peter A

    2012-04-01

    In making low-level radioactivity measurements of populations, it is commonly observed that a substantial portion of net results is negative. Furthermore, the observed variance of the measurement results arises from a combination of measurement uncertainty and population variability. This paper presents a method for disaggregating measurement uncertainty from population variability to produce a probability density function (PDF) of possibly true results. To do this, simple, justifiable and reasonable assumptions are made about the relationship of the measurements to the measurands (the 'true values'). The measurements are assumed to be unbiased, that is, that their average value is the average of the measurands. Using traditional estimates of each measurement's uncertainty, a likelihood PDF for each individual's measurand is produced. Then using the same assumptions and all the data from the population of individuals, a prior PDF of measurands for the population is produced. The prior PDF is non-negative, and the average is equal to the average of the measurement results for the population. Using Bayes's theorem, posterior PDFs of each individual measurand are calculated. The uncertainty in these bayesian posterior PDFs appears to be all Berkson with no remaining classical component. The method is applied to baseline bioassay data from the Hanford site. The data include (90)Sr urinalysis measurements of 128 people, (137)Cs in vivo measurements of 5337 people and (239)Pu urinalysis measurements of 3270 people. The method produces excellent results for the (90)Sr and (137)Cs measurements, since there are non-zero concentrations of these global fallout radionuclides in people who have not been occupationally exposed. The method does not work for the (239)Pu measurements in non-occupationally exposed people because the population average is essentially zero relative to the sensitivity of the measurement technique. The method is shown to give results similar to

  17. Effects of Shear Dependent Viscosity and Variable Thermal Conductivity on the Flow and Heat Transfer in a Slurry

    Directory of Open Access Journals (Sweden)

    Ling Miao

    2015-10-01

    Full Text Available In this paper we study the effects of variable viscosity and thermal conductivity on the heat transfer in the pressure-driven fully developed flow of a slurry (suspension between two horizontal flat plates. The fluid is assumed to be described by a constitutive relation for a generalized second grade fluid where the shear viscosity is a function of the shear rate, temperature and concentration. The heat flux vector for the slurry is assumed to follow a generalized form of the Fourier’s equation where the thermal conductivity k depends on the temperature as well as the shear rate. We numerically solve the governing equations of motion in the non-dimensional form and perform a parametric study to see the effects of various dimensionless numbers on the velocity, volume fraction and temperature profiles. The different cases of shear thinning and thickening, and the effect of the exponent in the Reynolds viscosity model, for the temperature variation in viscosity, are also considered. The results indicate that the variable thermal conductivity can play an important role in controlling the temperature variation in the flow.

  18. "Exercise Dependence"--A Problem or Natural Result of High Activity?

    Science.gov (United States)

    Phelan, Suzanne; Bond, Dale S.; Lang, Wei; Jordan, Dustin; Wing, Rena R.

    2011-01-01

    Objectives: To compare physical activity (PA) and exercise dependence (ED) in 267 weight-loss maintainers (WLM) and 213 normal-weight (NW) controls. Methods: PA and ED assessed via accelerometery and the Exercise Dependence Questionnaire. Results: WLM had higher PA levels and ED scores than those of NW (P less than 0.0001). WLM status (P = 0.006)…

  19. Some results on convergence rates for probabilities of moderate deviations for sums of random variables

    Directory of Open Access Journals (Sweden)

    Deli Li

    1992-01-01

    Full Text Available Let X, Xn, n≥1 be a sequence of iid real random variables, and Sn=∑k=1nXk, n≥1. Convergence rates of moderate deviations are derived, i.e., the rate of convergence to zero of certain tail probabilities of the partial sums are determined. For example, we obtain equivalent conditions for the convergence of series ∑n≥1(ψ2(n/nP(|Sn|≥nφ(n only under the assumptions convergence that EX=0 and EX2=1, where φ and ψ are taken from a broad class of functions. These results generalize and improve some recent results of Li (1991 and Gafurov (1982 and some previous work of Davis (1968. For b∈[0,1] and ϵ>0, letλϵ,b=∑n≥3((loglognb/nI(|Sn|≥(2+ϵnloglogn.The behaviour of Eλϵ,b as ϵ↓0 is also studied.

  20. The derivative-dependent functional variable separation for the evolution equations

    Institute of Scientific and Technical Information of China (English)

    Zhang Shun-Li; Lou Sen-Yue; Qu Chang-Zheng

    2006-01-01

    This paper studies variable separation of the evolution equations via the generalized conditional symmetry. To illustrate, we classify the extended nonlinear wave equation utt = A(u,ux)uxx+B(u,ux,ut) which admits the derivativedependent functional separable solutions (DDFSSs). We also extend the concept of the DDFSS to cover other variable separation approaches.

  1. NO x emissions from large point sources: variability in ozone production, resulting health damages and economic costs

    Science.gov (United States)

    Mauzerall, Denise L.; Sultan, Babar; Kim, Namsoug; Bradford, David F.

    We present a proof-of-concept analysis of the measurement of the health damage of ozone (O 3) produced from nitrogen oxides (NO=NO+NO) emitted by individual large point sources in the eastern United States. We use a regional atmospheric model of the eastern United States, the Comprehensive Air quality Model with Extensions (CAMx), to quantify the variable impact that a fixed quantity of NO x emitted from individual sources can have on the downwind concentration of surface O 3, depending on temperature and local biogenic hydrocarbon emissions. We also examine the dependence of resulting O 3-related health damages on the size of the exposed population. The investigation is relevant to the increasingly widely used "cap and trade" approach to NO x regulation, which presumes that shifts of emissions over time and space, holding the total fixed over the course of the summer O 3 season, will have minimal effect on the environmental outcome. By contrast, we show that a shift of a unit of NO x emissions from one place or time to another could result in large changes in resulting health effects due to O 3 formation and exposure. We indicate how the type of modeling carried out here might be used to attach externality-correcting prices to emissions. Charging emitters fees that are commensurate with the damage caused by their NO x emissions would create an incentive for emitters to reduce emissions at times and in locations where they cause the largest damage.

  2. Time-dependence in Relativistic Collisionless Shocks: Theory of the Variable "Wisps" in the Crab Nebula

    CERN Document Server

    Spitkovsky, A; Spitkovsky, Anatoly; Arons, Jonathan

    2004-01-01

    We describe results from time-dependent numerical modeling of the collisionless reverse shock terminating the pulsar wind in the Crab Nebula. We treat the upstream relativistic wind as composed of ions and electron-positron plasma embedded in a toroidal magnetic field, flowing radially outward from the pulsar in a sector around the rotational equator. The relativistic cyclotron instability of the ion gyrational orbit downstream of the leading shock in the electron-positron pairs launches outward propagating magnetosonic waves. Because of the fresh supply of ions crossing the shock, this time-dependent process achieves a limit-cycle, in which the waves are launched with periodicity on the order of the ion Larmor time. Compressions in the magnetic field and pair density associated with these waves, as well as their propagation speed, semi-quantitatively reproduce the behavior of the wisp and ring features described in recent observations obtained using the Hubble Space Telescope and the Chandra X-Ray Observator...

  3. State-dependent variability of dynamic functional connectivity between frontoparietal and default networks relates to cognitive flexibility.

    Science.gov (United States)

    Douw, Linda; Wakeman, Daniel G; Tanaka, Naoaki; Liu, Hesheng; Stufflebeam, Steven M

    2016-12-17

    The brain is a dynamic, flexible network that continuously reconfigures. However, the neural underpinnings of how state-dependent variability of dynamic functional connectivity (vdFC) relates to cognitive flexibility are unclear. We therefore investigated flexible functional connectivity during resting-state and task-state functional magnetic resonance imaging (rs-fMRI and t-fMRI, resp.) and performed separate, out-of-scanner neuropsychological testing. We hypothesize that state-dependent vdFC between the frontoparietal network (FPN) and the default mode network (DMN) relates to cognitive flexibility. Seventeen healthy subjects performed the Stroop color word test and underwent t-fMRI (Stroop computerized version) and rs-fMRI. Time series were extracted from a cortical atlas, and a sliding window approach was used to obtain a number of correlation matrices per subject. vdFC was defined as the standard deviation of connectivity strengths over these windows. Higher task-state FPN-DMN vdFC was associated with greater out-of-scanner cognitive flexibility, while the opposite relationship was present for resting-state FPN-DMN vdFC. Moreover, greater contrast between task-state and resting-state vdFC related to better cognitive performance. In conclusion, our results suggest that not only the dynamics of connectivity between these networks is seminal for optimal functioning, but also that the contrast between dynamics across states reflects cognitive performance.

  4. Time-dependent simulations of emission from FSRQ PKS1510-089: multiwavelength variability of external Compton and SSC models

    CERN Document Server

    Chen, Xuhui; Liang, Edison; Boettcher, Markus

    2012-01-01

    [abridged] We present results of modeling the SED and multiwavelength variability of the bright FSRQ PKS1510-089 with our time-dependent multizone Monte Carlo/Fokker-Planck code (Chen et al. 2001). As primary source of seed photons for inverse Compton scattering, we consider radiation from the broad line region (BLR), from the molecular torus, and the local synchrotron radiation (SSC). Different scenarios are assessed by comparing simulated light curves and SEDs with one of the best flares by PKS1510-089, in March 2009. The time-dependence of our code and its correct handling of light travel time effects allow us to fully take into account the effect of the finite size of the active region, and in turn to fully exploit the information carried by time resolved observed SEDs, increasingly available since the launch of Fermi. We confirm that the spectrum adopted for the external radiation has an important impact on the modeling of the SED, in particular for the lower energy end of the Compton component, observed...

  5. Exact and asymptotic results for insurance risk models with surplus-dependent premiums

    CERN Document Server

    Albrecher, Hansjörg; Palmowski, Zbigniew; Regensburger, Georg; Rosenkranz, Markus

    2011-01-01

    In this paper we develop a symbolic technique to obtain asymptotic expressions for ruin probabilities and discounted penalty functions in renewal insurance risk models when the premium income depends on the present surplus of the insurance portfolio. The analysis is based on boundary problems for linear ordinary differential equations with variable coefficients. The algebraic structure of the Green's operators allows us to develop an intuitive way of tackling the asymptotic behavior of the solutions, leading to exponential-type expansions and Cram\\'er-type asymptotics. Furthermore, we obtain closed-form solutions for more specific cases of premium functions in the compound Poisson risk model.

  6. The OmegaWhite Survey for Short-Period Variable Stars I: Overview and First Results

    CERN Document Server

    Macfarlane, S A; Ramsay, G; Groot, P J; Woudt, P A; Drew, J E; Barentsen, G; Eisloffel, J

    2015-01-01

    We present the goals, strategy and first results of the OmegaWhite survey: a wide-field high-cadence $g$-band synoptic survey which aims to unveil the Galactic population of short-period variable stars (with periods $<$ 80 min), including ultracompact binary star systems and stellar pulsators. The ultimate goal of OmegaWhite is to cover 400 square degrees along the Galactic Plane reaching a depth of $g = $ 21.5 mag (10$\\sigma$), using OmegaCam on the VLT Survey Telescope (VST). The fields are selected to overlap with surveys such as the Galactic Bulge Survey (GBS) and the VST Photometric H$\\alpha$ Survey of the Southern Galactic Plane (VPHAS+) for multi-band colour information. Each field is observed using 38 exposures of 39 s each, with a median cadence of $\\sim$2.7 min for a total duration of two hours. Within an initial 26 square degrees, we have extracted the light curves of 1.6 million stars, and have identified 613 variable candidates which satisfy our selection criteria. Furthermore, we present the ...

  7. Effects of spatial variability of precipitation for process-orientated hydrological modelling: results from two nested catchments

    Directory of Open Access Journals (Sweden)

    D. Tetzlaff

    2005-01-01

    Full Text Available The importance of considering the spatial distribution of rainfall for process-oriented hydrological modelling is well-known. However, the application of rainfall radar data to provide such detailed spatial resolution is still under debate. In this study the process-oriented TACD (Tracer Aided Catchment model, Distributed model had been used to investigate the effects of different spatially distributed rainfall input on simulated discharge and runoff components on an event base. TACD is fully distributed (50x50 m2 raster cells and was applied on an hourly base. As model input rainfall data from up to 11 ground stations and high resolution rainfall radar data from an operational C-band radar were used. For seven rainfall events the discharge simulations were investigated in further detail for the mountainous Brugga catchment (40 km2 and the St. Wilhelmer Talbach (15.2 km2 sub-basin, which are located in the Southern Black Forest Mountains, south-west Germany. The significance of spatial variable precipitation data was clearly demonstrated. Dependent on event characteristics, localized rain cells were occasionally poorly captured even by a dense ground station network, and this resulted in insufficient model results. For such events, radar data can provide better input data. However, an extensive data adjustment using ground station data is required. Therefore, a new method was developed that considers the rainfall intensity distribution. The use of the distributed catchment model allowed further insights into spatially variable impacts of different rainfall estimates. Impacts for discharge predictions are the largest in areas that are dominated by the production of fast runoff components. To conclude, the improvements for distributed runoff simulation using high resolution rainfall radar input data are strongly dependent on the investigated scale, the event characteristics, the existing

  8. Functional limit theorem for moving average processes generated by dependent random variables

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Let {Xt,t≥1} be a moving average process defined byXt = ∞∑j=0bjξt-j , where {bj,j≥0} is a sequence of real numbers and { ξt, ∞< t <∞ } is a doubly infinite sequence of strictly stationary φ- mixing random variables. Under conditions on { bj, j ≥0 }which entail that { Xt, t ≥ 1 } is either a long memory process or a linear process, we study asymptotics of Sn ( s ) = [ns]∑t=1 Xt (properly normalized). When { Xt, t≥1 } is a long memory process, we establish a functional limit theorem. When { Xt, t≥1 } is a linear process, we not only obtain the multi-dimensional weak convergence for { Xt, t≥1 }, but also weaken the moment condition on { ξt, - ∞< t <∞ } and the restriction on { bj,j≥0}. Finally, we give some applications of our results.

  9. EIT Micro-Variability Studies : Preliminary Results from the SOHO JOP 80 Campaign

    Science.gov (United States)

    Clette, F.; Berghmans, D.

    1999-09-01

    The first results from the high-cadence imaging campaign run in May 98, by several space-based instruments with ground support (SOHO JOP80), are presented. General properties and scaling laws are deduced for a fairly large sample of small-amplitude short-lived impulsive brightenings occuring locally in active region loops. From these, we derive some conclusions about similarities with soft-X ray microflares. Several classes of minor transients are distinguished, such as loop-like and twin brightenings. We find also evidence for propagating compressive waves in extended field lines rooted near one magnetic pole of the active region. This study provides a first inventory of small-scale variabilities in view of the full analysis of this huge and rich data set.

  10. Photometry of Variable Stars from Dome A, Antarctica: Results from the 2010 Observing Season

    CERN Document Server

    Wang, Lingzhi; Wang, Lifan; Ashley, Michael C B; Cui, Xiangqun; Feng, Long-Long; Gong, Xuefei; Lawrence, Jon S; Liu, Qiang; Luong-Van, Daniel; Pennypacker, Carl R; Shang, Zhaohui; Storey, John W V; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; York, Donald G; Zhou, Xu; Zhu, Zhenxi; Zhu, Zonghong

    2013-01-01

    We present results from a season of observations with the Chinese Small Telescope ARray (CSTAR), obtained over 183 days of the 2010 Antarctic winter. We carried out high-cadence time-series aperture photometry of 20,000 stars with i<15.3 mag located in a 23 square-degree region centered on the south celestial pole. We identified 188 variable stars, including 67 new objects relative to our 2008 observations, thanks to broader synoptic coverage, a deeper magnitude limit and a larger field of view. We used the photometric data set to derive site statistics from Dome A. Based on two years of observations, we find that extinction due to clouds at this site is less than 0.1 and 0.4 mag during 45% and 75% of the dark time, respectively.

  11. Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

    Science.gov (United States)

    Hock, R. A.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Chamberlin, P. C.; Woods, E. C.

    2010-01-01

    The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. . In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

  12. Thermochemoradiotherapy for advanced or recurrent head and neck cancer. Analysis of clinical results and background variables

    Energy Technology Data Exchange (ETDEWEB)

    Hoshina, Hideyuki; Takagi, Ritsuo; Nagashima, Katsuhiro; Fujita, Hajime; Miyamoto, Takeshi; Sohma, Yoh; Fukuda, Jun-ichi; Imai, Nobuyuki; Nagata, Masaki [Niigata Univ. (Japan). Faculty of Dentistry

    2001-03-01

    Eighteen patients with 25 unresectable advanced or recurrent head and neck cancers (squamous cell carcinomas) received thermochemotherapy in combination with radiotherapy. The total radiation dose ranged from 50 to 82 Gy (mean, 65.6 Gy). Patients received thermochemotherapy twice a week, for a total number of 8.8 sessions, on average. The temperature in the tumor, as a result of the hyperthermia, was over 42 deg C in 185 (84.5%) of the 219 treatments. Three kinds of heating systems were used: a 13.56-MHz radiofrequency system, a 2450-MHz microwave system, and a radiofrequency interstitial system. The total amount of administered CDDP ranged from 40 to 300 mg (mean, 110 mg), combined with PEP and/or 5FU. Background factors (tumor factors and treatment factors) were investigated in detail, and the clinical results (tumor response and the 5-year cumulative focal control rate) were evaluated. The relationship between these two results was then analyzed using univariate and multivariate statistics. The clinical results of patients with a WHO histological classification of grade 3 were poor compared with patients with a classification of grade 1 or 2. The difference between these two results was significant when analyzed using univariate statistics, but not significant when analyzed using multivariate statistics. The clinical results of patients with primary lesions surrounded by bony tissues were slightly poor compared with those of patients whose lesions were surrounded by soft tissues, but the difference between these two results was not significant. Successful treatment of refractory recurrent tumors, large tumor masses, and diffuse invasive carcinomas was not affected by the treatment factors (heating systems, heating sessions, radiation dose, and CDDP dose and drug combination). These results suggest that refractory recurrence, proximity to bony tissues, tumor size, and histological malignancy might not be prognostic variables for thermochemoradiotherapy strategy

  13. Dependency of the Cusp Density Anomaly on the Variability of Forcing Inside and Outside the Cusp

    Science.gov (United States)

    Brinkman, D. G.; Walterscheid, R. L.; Clemmons, J. H.

    2014-12-01

    the model results to CHAMP and Streak observations and assess the distinctive features of the observations in terms of the various dependencies involved. Acknowledgements: This research was supported by The Aerospace Corporation's Technical Investment program

  14. Modelling the interannual variability of extreme wave climate combining a time-dependent GEV model and Self-Organizing Maps

    Science.gov (United States)

    Izaguirre, Cristina; Mendez, Fernando J.; Camus, Paula; Minguez, Roberto; Menendez, Melisa; Losada, Iñigo J.

    2010-05-01

    It is well known that the seasonal-to-interannual variability of extreme wave climate is linked to the anomalies of the atmosphere circulation. In this work, we analyze the relationships between extreme significant wave height at a particular site and the synoptic-scale weather type. We combine a time-dependent Generalized Extreme Value (GEV) model for monthly maxima and self-organizing maps (SOM) applied to monthly mean sea level pressure field (SLP) anomalies. These time-varying SLP anomalies are encoded using principal component analysis, obtaining the corresponding spatial patterns (Empirical Orthogonal Functions, EOFs) and the temporal modes (PC, principal components). The location, scale and shape parameters of the GEV distribution are parameterized in terms of harmonic functions (seasonality) and linear covariates for the PCs (interannual variability) and the model is fitted using standard likelihood theory and an automatic parameter selection procedure, which avoids overparameterization. Thus, the resulting anomalies of the location and scale parameters with respect to the seasonality are projected to the SOM lattice obtaining the influence of every weather type on the extreme wave height probability distribution (and subsequently, return-level quantiles). The use of Self-organizing maps allows an easy visualization of the results. The application of the method to different areas in the North Atlantic Ocean helps us to quantify the importance of the North Atlantic Oscillation and the East Atlantic pattern in the location and scale parameters of the GEV probability distribution. Additionally, this work opens new forecasting possibilities for the probabilities of extreme events based on synoptic-scale patterns.

  15. Modeling Time-Dependent Behavior of Concrete Affected by Alkali Silica Reaction in Variable Environmental Conditions

    Science.gov (United States)

    Alnaggar, Mohammed; Di Luzio, Giovanni; Cusatis, Gianluca

    2017-01-01

    Alkali Silica Reaction (ASR) is known to be a serious problem for concrete worldwide, especially in high humidity and high temperature regions. ASR is a slow process that develops over years to decades and it is influenced by changes in environmental and loading conditions of the structure. The problem becomes even more complicated if one recognizes that other phenomena like creep and shrinkage are coupled with ASR. This results in synergistic mechanisms that can not be easily understood without a comprehensive computational model. In this paper, coupling between creep, shrinkage and ASR is modeled within the Lattice Discrete Particle Model (LDPM) framework. In order to achieve this, a multi-physics formulation is used to compute the evolution of temperature, humidity, cement hydration, and ASR in both space and time, which is then used within physics-based formulations of cracking, creep and shrinkage. The overall model is calibrated and validated on the basis of experimental data available in the literature. Results show that even during free expansions (zero macroscopic stress), a significant degree of coupling exists because ASR induced expansions are relaxed by meso-scale creep driven by self-equilibriated stresses at the meso-scale. This explains and highlights the importance of considering ASR and other time dependent aging and deterioration phenomena at an appropriate length scale in coupled modeling approaches. PMID:28772829

  16. Dark focus of accommodation as dependent and independent variables in visual display technology

    Science.gov (United States)

    Jones, Sherrie; Kennedy, Robert; Harm, Deborah

    1992-01-01

    When independent stimuli are available for accommodation, as in the dark or under low contrast conditions, the lens seeks its resting position. Individual differences in resting positions are reliable, under autonomic control, and can change with visual task demands. We hypothesized that motion sickness in a flight simulator might result in dark focus changes. Method: Subjects received training flights in three different Navy flight simulators. Two were helicopter simulators entailed CRT presentation using infinity optics, one involved a dome presentation of a computer graphic visual projection system. Results: In all three experiments there were significant differences between dark focus activity before and after simulator exposure when comparisons were made between sick and not-sick pilot subjects. In two of these experiments, the average shift in dark focus for the sick subjects was toward increased myopia when each subject was compared to his own baseline. In the third experiment, the group showed an average shift outward of small amount and the subjects who were sick showed significantly less outward movement than those who were symptom free. Conclusions: Although the relationship is not a simple one, dark focus changes in simulator sickness imply parasympathetic activity. Because changes can occur in relation to endogenous and exogenous events, such measurement may have useful applications as dependent measures in studies of visually coupled systems, virtual reality systems, and space adaptation syndrome.

  17. The relative dependence of Spanish landscape pattern on environmental and geographical variables over time

    NARCIS (Netherlands)

    Ortega, M.; Bunce, R.G.H.; Barrio, del J.M.G.; Elena-Rossello, R.

    2008-01-01

    The analysis of the dependence of landscape patterns on environment was carried out in order to investigate the landscape structure evolution of Spain. The underlying concept was that the dependence between landscape spatial structure and environmental factors could be gradually decreasing over

  18. Patterns of variability in early-life traits of fishes depend on spatial scale of analysis.

    Science.gov (United States)

    Di Franco, Antonio; Guidetti, Paolo

    2011-06-23

    Estimates of early-life traits of fishes (e.g. pelagic larval duration (PLD) and spawning date) are essential for investigating and assessing patterns of population connectivity. Such estimates are available for a large number of both tropical and temperate fish species, but few studies have assessed their variability in space, especially across multiple scales. The present study, where a Mediterranean fish (i.e. the white seabream Diplodus sargus sargus) was used as a model, shows that spawning date and PLD are spatially more variable at a scale of kilometres than at a scale of tens to hundreds of kilometres. This study indicates the importance of considering spatial variability of early-life traits of fishes in order to properly delineate connectivity patterns at larval stages (e.g. by means of Lagrangian simulations), thus providing strategically useful information on connectivity and relevant management goals (e.g. the creation of networks of marine reserves).

  19. The Notion of Variability in Software Architecture – Results from a Preliminary Exploratory Study

    NARCIS (Netherlands)

    Galster, Matthias; Avgeriou, Paris

    2011-01-01

    Context: In the software product line domain, the concept of variability is well recognized. However, variability in the context of software architecture still seems to be poorly understood. Objective: In this paper, we aim at contributing to the development of a basic understanding of the notion of

  20. The Notion of Variability in Software Architecture – Results from a Preliminary Exploratory Study

    NARCIS (Netherlands)

    Galster, Matthias; Avgeriou, Paris

    2011-01-01

    Context: In the software product line domain, the concept of variability is well recognized. However, variability in the context of software architecture still seems to be poorly understood. Objective: In this paper, we aim at contributing to the development of a basic understanding of the notion of

  1. Possible evidence for a variable fine structure constant from QSO absorption lines motivations, analysis and results

    CERN Document Server

    Murphy, M T; Flambaum, V V; Dzuba, V A; Churchill, C W; Prochaska, J X; Barrow, John D; Wolfe, A M

    2001-01-01

    An experimental search for variation in the fundamental coupling constants is strongly motivated by modern high-energy physics theories. Comparison of quasar absorption line spectra with laboratory spectra provides a sensitive probe for variability of the fine structure constant, alpha, over cosmological time-scales. We have previously developed and applied a new method providing an order of magnitude gain in precision over previous optical astrophysical constraints. Here we extend that work by including new quasar spectra of damped Lyman-alpha absorption systems. We also re-analyse our previous lower redshift data and confirm our initial results. The constraints on alpha come from simultaneous fitting of absorption lines of subsets of the following species: Mg I, Mg II, Al II, Al III, Si II, Cr II, Fe II, Ni II and Zn II. We present a detailed description of our methods and results based on an analysis of 49 quasar absorption systems (towards 28 QSOs) covering the redshift range 0.5 < z < 3.5. There is...

  2. The CIDA-QUEST Large Scale Variability Survey in the Orion OB Association initial results

    CERN Document Server

    Briceño, C; Calvet, N; Hartmann, L; Briceno, Cesar; Calvet, Nuria; Hartmann, Lee

    1999-01-01

    Using the 8k x 8k CCD Mosaic Camera on the 1m Schmidt telescope in Venezuela, we are conducting a large-scale, deep optical, multiepoch, photometric (BVRIHa) survey over 120 sq.deg. in the Orion OB association, aimed at identifying the low mass stellar populations with ages less than about 10 Myr. We present initial results for a 34 sq.deg. area spanning Orion 1b, 1a and the B Cloud. Using variability as our main selection criterion we derive much cleaner samples than with the usual single-epoch photometric selection, allowing us to attain a much higher efficiency in follow up spectroscopy and resulting in an preliminary list of 74 new low-mass (~ 0.4 Msun) pre-main sequence stars. Though preliminary, this list of new T Tauri stars already suggests that the fraction of accreting young stars in 1a is much lower than in 1b, which would be expected if 1a is indeed older than 1b. We are analyzing in detail the light curves of these new stars, and spectroscopy of further candidates is under way.

  3. A numerical model for density-and-viscosity-dependent flows in two-dimensional variably saturated porous media

    Science.gov (United States)

    Boufadel, Michel C.; Suidan, Makram T.; Venosa, Albert D.

    1999-04-01

    We present a formulation for water flow and solute transport in two-dimensional variably saturated media that accounts for the effects of the solute on water density and viscosity. The governing equations are cast in a dimensionless form that depends on six dimensionless groups of parameters. These equations are discretized in space using the Galerkin finite element formulation and integrated in time using the backward Euler scheme with mass lumping. The modified Picard method is used to linearize the water flow equation. The resulting numerical model, the MARUN model, is verified by comparison to published numerical results. It is then used to investigate beach hydraulics at seawater concentration (about 30 g l -1) in the context of nutrients delivery for bioremediation of oil spills on beaches. Numerical simulations that we conducted in a rectangular section of a hypothetical beach revealed that buoyancy in the unsaturated zone is significant in soils that are fine textured, with low anisotropy ratio, and/or exhibiting low physical dispersion. In such situations, application of dissolved nutrients to a contaminated beach in a freshwater solution is superior to their application in a seawater solution. Concentration-engendered viscosity effects were negligible with respect to concentration-engendered density effects for the cases that we considered.

  4. Seismic hazard from induced seismicity: effect of time-dependent hazard variables

    Science.gov (United States)

    Convertito, V.; Sharma, N.; Maercklin, N.; Emolo, A.; Zollo, A.

    2012-12-01

    of the peak-ground motion parameters (e.g., magnitude, geometrical spreading and anelastic attenuation). Moreover, we consider both the inter-event and intra-event components of the standard deviation. For comparison, we use the same dataset analyzed by Convertito et al. (2012), and for successive time windows we perform the regression analysis to infer the time-dependent coefficients of the GMPE. After having tested the statistical significance of the new coefficients and having verified a reduction in the total standard deviation, we introduce the new model in the hazard integral. Hazard maps and site-specific analyses in terms of a uniform hazard spectrum are used to compare the new results with those obtained in our previous study to investigate which coefficients and which components of the total standard deviation do really matter for refining seismic hazard estimates for induced seismicity. Convertito et al. (2012). From Induced Seismicity to Direct Time-Dependent Seismic Hazard, BSSA 102(6), doi:10.1785/0120120036.

  5. Seasonal variability in clinical care of COPD outpatients: results from the Andalusian COPD audit

    Directory of Open Access Journals (Sweden)

    López-Campos JL

    2017-03-01

    Full Text Available Jose Luis López-Campos,1,2 Maria Abad Arranz,1 Carmen Calero-Acuña,1,2 Fernando Romero-Valero,3 Ruth Ayerbe-García,4 Antonio Hidalgo-Molina,3 Ricardo I Aguilar-Pérez-Grovas,4 Francisco García-Gil,5 Francisco Casas-Maldonado,6 Laura Caballero-Ballesteros,5 María Sánchez-Palop,6 Dolores Pérez-Tejero,7 Alejandro Segado Soriano,7 Jose Calvo-Bonachera,8 Bárbara Hernández-Sierra,8 Adolfo Doménech,9 Macarena Arroyo-Varela,9 Francisco González-Vargas,10 Juan J Cruz-Rueda10 1Unidad Médico-Quirúrgica de Enfermedades Respiratorias, Instituto de Biomedicina de Sevilla (IBiS, Hospital Universitario Virgen del Rocío/Universidad de Sevilla, Seville, 2CIBER de Enfermedades Respiratorias (CIBERES, Instituto de Salud Carlos III, Madrid, 3Sección de Neumología, Hospital Puerta del Mar, Cádiz, 4Servicio de Neumología, Hospital Juan Ramón Jiménez, Huelva, 5Servicio de Neumología, Hospital Universitario Reina Sofía, Córdoba, 6Servicio de Neumología, Hospital Universitario San Cecilio, Granada, 7Sección de Neumología, Hospital Infanta Margarita, Cabra, Córdoba, 8Servicio de Neumología, Hospital Torrecárdenas, Almería, 9Servicio de Neumología, Hospital Regional Universitario de Málaga, Málaga, 10Servicio de Neumología, Hospital Universitario Virgen de las Nieves, Granada, Spain Objectives: Clinical practice in chronic obstructive pulmonary disease (COPD can be influenced by weather variability throughout the year. To explore the hypothesis of seasonal variability in clinical practice, the present study analyzes the results of the 2013–2014 Andalusian COPD audit with regard to changes in clinical practice according to the different seasons.Methods: The Andalusian COPD audit was a pilot clinical project conducted from October 2013 to September 2014 in outpatient respiratory clinics of hospitals in Andalusia, Spain (8 provinces with more than 8 million inhabitants with retrospective data gathering. For the present analysis

  6. Time-dependent excitation and ionization modelling of absorption-line variability due to GRB080310

    DEFF Research Database (Denmark)

    Vreeswijk, P.M.; De Cia, A.; Jakobsson, P.

    2013-01-01

    We model the time-variable absorption of Feii, Feiii, Siii, Cii and Crii detected in Ultraviolet and Visual Echelle Spectrograph (UVES) spectra of gamma-ray burst (GRB) 080310, with the afterglow radiation exciting and ionizing the interstellar medium in the host galaxy at a redshift of z = 2.427...

  7. Architecting product diversification - Formalizing variability dependencies in software product family engineering

    NARCIS (Netherlands)

    Jaring, M; Bosch, J; Ehrich, HD; Schewe, KD

    2004-01-01

    In a software product family context, software architects design architectures that support product diversification in both space (multiple contexts) and time (changing contexts). Product diversification is based on the concept of variability: a single architecture and a set of components support a

  8. A characterization of marginal distributions of (possibly dependent) lifetime variables which right censor each other

    NARCIS (Netherlands)

    Bedford, T.; Meilijson, I.

    1997-01-01

    It is well known that the joint distribution of a pair of lifetime variables $X_1$ and $X_2$ which right censor each other cannot be specified in terms of the subsurvival functions $$P(X_2 > X_1 > x), \\quad P(X_1 > X_2 > x)$ \\quad \\text{and} \\quad $P(X_1 = X_2 > x)$$ without additional assumptions s

  9. Age Dependent Variability in Gene Expression in Fischer 344 Rat Retina.

    Science.gov (United States)

    Recent evidence suggests older adults may be a sensitive population with regard to environmental exposure to toxic compounds. One source of this sensitivity could be an enhanced variability in response. Studies on phenotypic differences have suggested that variation in response d...

  10. Extreme Ultraviolet Variability Experiment (EVE) Multiple EUV Grating Spectrographs (MEGS): Radiometric Calibrations and Results

    Science.gov (United States)

    Hock, R. A.; Chamberlin, P. C.; Woods, T. N.; Crotser, D.; Eparvier, F. G.; Woodraska, D. L.; Woods, E. C.

    2012-01-01

    The NASA Solar Dynamics Observatory (SDO), scheduled for launch in early 2010, incorporates a suite of instruments including the Extreme Ultraviolet Variability Experiment (EVE). EVE has multiple instruments including the Multiple Extreme ultraviolet Grating Spectrographs (MEGS) A, B, and P instruments, the Solar Aspect Monitor (SAM), and the Extreme ultraviolet SpectroPhotometer (ESP). The radiometric calibration of EVE, necessary to convert the instrument counts to physical units, was performed at the National Institute of Standards and Technology (NIST) Synchrotron Ultraviolet Radiation Facility (SURF III) located in Gaithersburg, Maryland. This paper presents the results and derived accuracy of this radiometric calibration for the MEGS A, B, P, and SAM instruments, while the calibration of the ESP instrument is addressed by Didkovsky et al. ( Solar Phys., 2010, doi:10.1007/s11207-009-9485-8). In addition, solar measurements that were taken on 14 April 2008, during the NASA 36.240 sounding-rocket flight, are shown for the prototype EVE instruments.

  11. Photometric Variability in the CSTAR Field: Results from the 2008 Data Set

    Science.gov (United States)

    Wang, Songhu; Zhang, Hui; Zhou, Xu; Zhou, Ji-Lin; Fu, Jian-Ning; Yang, Ming; Liu, Huigen; Xie, Jiwei; Wang, Lifan; Wang, Lingzhi; Wittenmyer, R. A.; Ashley, M. C. B.; Feng, Long-Long; Gong, Xuefei; Lawrence, J. S.; Liu, Qiang; Luong-Van, D. M.; Ma, Jun; Peng, Xiyan; Storey, J. W. V.; Wu, Zhenyu; Yan, Jun; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhang, Tianmeng; Zhang, Xiaojia; Zhu, Zhenxi; Zou, Hu

    2015-06-01

    The Chinese Small Telescope Array (CSTAR) is the first telescope facility built at Dome A, Antarctica. During the 2008 observing season, the installation provided long-baseline and high-cadence photometric observations in the i-band for 18,145 targets within 20 {{deg }2} CSTAR field around the South Celestial Pole for the purpose of monitoring the astronomical observing quality of Dome A and detecting various types of photometric variability. Using sensitive and robust detection methods, we discover 274 potential variables from this data set, 83 of which are new discoveries. We characterize most of them, providing the periods, amplitudes, and classes of variability. The catalog of all these variables is presented along with the discussion of their statistical properties.

  12. Photometric Variability in the CSTAR Field: Results From the 2008 Data Set

    CERN Document Server

    Wang, Songhu; Zhou, Xu; Zhou, Ji-Lin; Fu, Jian-Ning; Yang, Ming; Liu, Huigen; Xie, Jiwei; Wang, Lifan; Wang, Lingzhi; Wittenmyer, R A; Ashley, M C B; Feng, Long-Long; Gong, Xuefei; Lawrence, J S; Liu, Qiang; Luong-Van, D M; Ma, Jun; Peng, Xiyan; Storey, J W V; Wu, Zhenyu; Yan, Jun; Yang, Huigen; Yang, Ji; Yuan, Xiangyan; Zhang, Tianmeng; Zhang, Xiaojia; Zhu, Zhenxi; Zou, Hu

    2015-01-01

    The Chinese Small Telescope ARray (CSTAR) is the first telescope facility built at Dome A, Antarctica. During the 2008 observing season, the installation provided long-baseline and high-cadence photometric observations in the i-band for 18,145 targets within 20 deg2 CSTAR field around the South Celestial Pole for the purpose of monitoring the astronomical observing quality of Dome A and detecting various types of photometric variability. Using sensitive and robust detection methods, we discover 274 potential variables from this data set, 83 of which are new discoveries. We characterize most of them, providing the periods, amplitudes and classes of variability. The catalog of all these variables is presented along with the discussion of their statistical properties.

  13. Accurate approximate solution to nonlinear oscillators in which the restoring force is inversely proportional to the dependent variable

    Energy Technology Data Exchange (ETDEWEB)

    Belendez, A; Gimeno, E; Mendez, D I; Alvarez, M L [Departamento de Fisica, IngenierIa de Sistemas y TeorIa de la Senal, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain); Fernandez, E [Departamento de Optica, FarmacologIa y AnatomIa, Universidad de Alicante, Apartado 99, E-03080 Alicante (Spain)], E-mail: a.belendez@ua.es

    2008-06-15

    A modified generalized, rational harmonic balance method is used to construct approximate frequency-amplitude relations for a conservative nonlinear singular oscillator in which the restoring force is inversely proportional to the dependent variable. The procedure is used to solve the nonlinear differential equation approximately. The approximate frequency obtained using this procedure is more accurate than those obtained using other approximate methods and the discrepancy between the approximate frequency and the exact one is lower than 0.40%.

  14. Three Ingredients for Improved Global Aftershock Forecasts: Tectonic Region, Time-Dependent Catalog Incompleteness, and Inter-Sequence Variability

    Science.gov (United States)

    Page, M. T.; Hardebeck, J.; Felzer, K. R.; Michael, A. J.; van der Elst, N.

    2015-12-01

    Following a large earthquake, seismic hazard can be orders of magnitude higher than the long-term average as a result of aftershock triggering. Due to this heightened hazard, there is a demand from emergency managers and the public for rapid, authoritative, and reliable aftershock forecasts. In the past, USGS aftershock forecasts following large, global earthquakes have been released on an ad-hoc basis with inconsistent methods, and in some cases, aftershock parameters adapted from California. To remedy this, we are currently developing an automated aftershock product that will generate more accurate forecasts based on the Reasenberg and Jones (Science, 1989) method. To better capture spatial variations in aftershock productivity and decay, we estimate regional aftershock parameters for sequences within the Garcia et al. (BSSA, 2012) tectonic regions. We find that regional variations for mean aftershock productivity exceed a factor of 10. The Reasenberg and Jones method combines modified-Omori aftershock decay, Utsu productivity scaling, and the Gutenberg-Richter magnitude distribution. We additionally account for a time-dependent magnitude of completeness following large events in the catalog. We generalize the Helmstetter et al. (2005) equation for short-term aftershock incompleteness and solve for incompleteness levels in the global NEIC catalog following large mainshocks. In addition to estimating average sequence parameters within regions, we quantify the inter-sequence parameter variability. This allows for a more complete quantification of the forecast uncertainties and Bayesian updating of the forecast as sequence-specific information becomes available.

  15. Contact-dependent performance variability of monolayer MoS{sub 2} field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Han, Gyuchull; Yoon, Youngki, E-mail: youngki.yoon@uwaterloo.ca [Department of Electrical and Computer Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2014-11-24

    Using self-consistent quantum transport simulations, we investigate the performance variability of monolayer molybdenum disulfide (MoS{sub 2}) field-effect transistors (FETs) with various contact properties. Varying the Schottky barrier in MoS{sub 2} FETs affects the output characteristics more significantly than the transfer characteristics. If doped contacts are realized, the performance variation due to non-ideal contacts becomes negligible; otherwise, channel doping can effectively suppress the performance variability in metal-contact devices. Our scaling study also reveals that for sub-10-nm channels, doped-contact devices can be more robust in terms of switching, while metal-contact MoS{sub 2} FETs can undergo the smaller penalty in output conductance.

  16. EXISTENCE RESULTS FOR IMPULSIVE NEUTRAL EVOLUTION DIFFERENTIAL EQUATIONS WITH STATE-DEPENDENT DELAY

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    This paper is mainly concerned with the existence of mild solutions to a first order impulsive neutral evolution differential equations with state-dependent delay. By suitable fixed point theorems combined with theories of evolution systems,we prove some existence theorems. As an application,an example is also given to illustrate the obtained results.

  17. Therapeutic effects of ritual ayahuasca use in the treatment of substance dependence--qualitative results.

    Science.gov (United States)

    Loizaga-Velder, Anja; Verres, Rolf

    2014-01-01

    This qualitative empirical study explores the ritual use of ayahuasca in the treatment of addictions. Ayahuasca is an Amazonian psychedelic plant compound created from an admixture of the vine Banisteriopsis caapi and the bush Psychotria viridis. The study included interviews with 13 therapists who apply ayahuasca professionally in the treatment of addictions (four indigenous healers and nine Western mental health professionals with university degrees), two expert researchers, and 14 individuals who had undergone ayahuasca-assisted therapy for addictions in diverse contexts in South America. The study provides empirically based hypotheses on therapeutic mechanisms of ayahuasca in substance dependence treatment. Findings indicate that ayahuasca can serve as a valuable therapeutic tool that, in carefully structured settings, can catalyze neurobiological and psychological processes that support recovery from substance dependencies and the prevention of relapse. Treatment outcomes, however, can be influenced by a number of variables that are explained in this study. In addition, issues related to ritual transfer and strategies for minimizing undesired side-effects are discussed.

  18. The Relationships between Cognitive Style of Field Dependence and Learner Variables in E-Learning Instruction

    Science.gov (United States)

    Sozcu, Omer Faruk

    2014-01-01

    This study examines the relationships between cognitive styles of field dependent learners with their attitudes towards e-learning (distance education) and instructional behavior in e-learning instruction. The Group Embedded Figures Test (GEFT) and the attitude survey (for students' preferences) towards e-learning instruction as distance education…

  19. Influence of galactic cosmic rays and solar variability on aerosols, clouds and climate: Results from the CLOUD experiment at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Curtius, Joachim [Institute for Atmosph. and Envir. Sciences, Univ. of Frankfurt am Main (Germany)

    2013-07-01

    The potential influence of ions produced from galactic cosmic rays on the formation of new aerosol particles in the atmosphere may play an important role relevant for aerosol properties, cloud formation and climate. Variability of galactic cosmic rays due to modulating influences from the sun therefore may affect (regional) climate on various time scales. A quantitative understanding of the role of ions for atmospheric aerosol formation has not been reached, but also the dependence of aerosol formation on the concentration of the nucleating substances such as gaseous sulfuric acid, ammonia and amines is missing. Here results from the CLOUD experiment at CERN are presented. CLOUD is a new aerosol and cloud chamber facility at CERN. The chamber can be exposed to a pion beam from CERN to simulate various levels of atmospheric ionization. CLOUD has been set up to investigate aerosol and cloud processes under well-controlled laboratory conditions. We find that cosmic ray ionization substantially increases the nucleation rate of pure sulfuric acid/water particles while charge effects are much less pronounced for ternary systems including ammonia or dimethylamine. The results from the CLOUD experiments have been used to develop a new parameterization of aerosol nucleation which has been included in a global climate model. Impacts of our findings for cloud formation and climate are discussed.

  20. GENERAL APROACH TO MODELING NONLINEAR AMPLITUDE AND FREQUENCY DEPENDENT HYSTERESIS EFFECTS BASED ON EXPERIMENTAL RESULTS

    Directory of Open Access Journals (Sweden)

    Christopher Heine

    2014-08-01

    Full Text Available A detailed description of the rubber parts’ properties is gaining in importance in the current simulation models of multi-body simulation. One application example is a multi-body simulation of the washing machine movement. Inside the washing machine, there are different force transmission elements, which consist completely or partly of rubber. Rubber parts or, generally, elastomers usually have amplitude-dependant and frequency-dependent force transmission properties. Rheological models are used to describe these properties. A method for characterization of the amplitude and frequency dependence of such a rheological model is presented within this paper. Within this method, the used rheological model can be reduced or expanded in order to illustrate various non-linear effects. An original result is given with the automated parameter identification. It is fully implemented in Matlab. Such identified rheological models are intended for subsequent implementation in a multi-body model. This allows a significant enhancement of the overall model quality.

  1. Modeling the Effects of a Normal-Stress-Dependent State Variable, Within the Rate- and State-Dependent Friction Framework, at Stepovers and Dip-Slip Faults

    Science.gov (United States)

    Ryan, Kenny J.; Oglesby, David D.

    2017-03-01

    The development of the rate- and state-dependent friction framework (Dieterich Appl Geophys 116:790-806, 1978; J Geophys Res 84, 2161-2168, 1979; Ruina Friction laws and instabilities: a quasistatic analysis of some dry friction behavior, Ph.D. Thesis, Brown Univ., Providence, R.I., 1980; J Geophys Res 88:10359-10370, 1983) includes the dependence of friction coefficient on normal stress (Linker and Dieterich J Geophys Res 97:4923-4940, 1992); however, a direct dependence of the friction law on time-varying normal stress in dynamic stepover and dip-slip fault models has not yet been extensively explored. Using rate- and state-dependent friction laws and a 2-D dynamic finite element code (Barall J Int 178, 845-859, 2009), we investigate the effect of the Linker-Dieterich dependence of state variable on normal stress at stepovers and dip-slip faults, where normal stress should not be constant with time (e.g., Harris and Day J Geophys Res 98:4461-4472, 1993; Nielsen Geophys Res Lett 25:125-128, 1998). Specifically, we use the relation d ψ/d t = -( α/ σ)(d σ/d t) from Linker and Dieterich (J Geophys Res 97:4923-4940, 1992), in which a change in normal stress leads to a change in state variable of the opposite sign. We investigate a range of values for alpha, which scales the impact of the normal stress change on state, from 0 to 0.5 (laboratory values range from 0.2 to 0.56). For stepovers, we find that adding normal-stress dependence to the state variable delays or stops re-nucleation on the secondary fault segment when compared to normal-stress-independent state evolution. This inhibition of jumping rupture is due to the fact that re-nucleation along the secondary segment occurs in areas of decreased normal stress in both compressional and dilational stepovers. However, the magnitude of such an effect differs between dilational and compressional systems. Additionally, it is well known that the asymmetric geometry of reverse and normal faults can lead to greater

  2. The greek infinitive in variable deliberative, principally dependent questions: an interpretation in terms of naturalness theory

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    Jerneja Kavčič

    2004-12-01

    Full Text Available In the present paper I investigate the use of the infinitive in dependent delibera­ tive clauses in Greek, a phenomenon occurring in several (modern languages, cf. Slovene Nisem vedel, kaj storiti. 'I didn't know what to do?', English I didn't know what to do., German Was tun? 'What to do?'l. In the first part I present the development of deliberative infinitive clauses in Post-Classical Greek with a special emphasis on the use of this form in two Early Byzantine prose writings (in Pratum Spirituale and in Vita Theodori Syceotae, both belonging to the 6th;7th century AD, where some peculiarities are observed. In the second part an attempt is made to interpret the basic characteristics of the Greek infinitive in dependent deliberative clauses from the perspective of Naturalness Theory.

  3. Variability in projected elevation dependent warming in boreal midlatitude winter in CMIP5 climate models and its potential drivers

    Science.gov (United States)

    Rangwala, Imtiaz; Sinsky, Eric; Miller, James R.

    2016-04-01

    The future rate of climate change in mountains has many potential human impacts, including those related to water resources, ecosystem services, and recreation. Analysis of the ensemble mean response of CMIP5 global climate models (GCMs) shows amplified warming in high elevation regions during the cold season in boreal midlatitudes. We examine how the twenty-first century elevation-dependent response in the daily minimum surface air temperature [d(ΔTmin)/dz] varies among 27 different GCMs during winter for the RCP 8.5 emissions scenario. The focus is on regions within the northern hemisphere mid-latitude band between 27.5°N and 40°N, which includes both the Rocky Mountains and the Tibetan Plateau/Himalayas. We find significant variability in d(ΔTmin)/dz among the individual models ranging from 0.16 °C/km (10th percentile) to 0.97 °C/km (90th percentile), although nearly all of the GCMs (24 out of 27) show a significant positive value for d(ΔTmin)/dz. To identify some of the important drivers associated with the variability in d(ΔTmin)/dz during winter, we evaluate the co-variance between d(ΔTmin)/dz and the differential response of elevation-based anomalies in different climate variables as well as the GCMs' spatial resolution, their global climate sensitivity, and their elevation-dependent free air temperature response. We find that d(ΔTmin)/dz has the strongest correlation with elevation-dependent increases in surface water vapor, followed by elevation-dependent decreases in surface albedo, and a weak positive correlation with the GCMs' free air temperature response.

  4. Regression mixture models : Does modeling the covariance between independent variables and latent classes improve the results?

    NARCIS (Netherlands)

    Lamont, A.E.; Vermunt, J.K.; Van Horn, M.L.

    2016-01-01

    Regression mixture models are increasingly used as an exploratory approach to identify heterogeneity in the effects of a predictor on an outcome. In this simulation study, we tested the effects of violating an implicit assumption often made in these models; that is, independent variables in the

  5. Variability in activity and results from drug assessments by pharmacy and therapeutics committees in Spanish hospitals.

    Science.gov (United States)

    Puigventós Latorre, F; Santos-Ramos, B; Ortega Eslava, A; Durán-García, M E

    2011-01-01

    To quantify the Spanish Pharmacy and Therapeutics Committees (P&TC) activity with regard to assessing and selecting drugs and describing variability in decisions made to include them. Descriptive, cross-sectional study based on a questionnaire aimed to 513 hospitals with more than 75 beds. We included questions referring to the P&TC resolutions, the therapeutic positioning and assessment reports. Recruitment was carried out between November 2007 and January 2008. Variability among P&TC conclusions were presented in five categories or levels of coincidence. One hundred and seventy-five hospitals participated, with a response rate of 34% (54% of beds). The mean (SD) number of drug-indications assessed per hospital was 10.35 (7.45). The proportion of assessments that conclude with drug inclusion or rejection was 75.3 and 21.4%, respectively. 16.2% concluded with therapeutic equivalence. Conditions for use were established for 64% of them, and 33% were included in a clinical guide. With regard to variability, 81.0% of assessments coincided with the conclusion to include or reject the drug. A contradictory decision was made for 19.0%. Drug assessment and selection activity in hospitals involve an amount of work. The proportion of drugs approved is similar in different types of hospitals. There is extensive variability as regards deciding upon inclusion and is similar to studies conducted in other countries. They indicate that a standardising methodology would be recommendable. Copyright © 2010 SEFH. Published by Elsevier Espana. All rights reserved.

  6. First results from MASIV : The microarcsecond scintillation-induced variability survey

    NARCIS (Netherlands)

    Lovell, JEJ; Jauncey, DL; Bignall, HE; Kedziora-Chudczer, L; Macquart, JP; Rickett, BJ; Tzioumis, AK

    2003-01-01

    We are undertaking a large-scale, microarcsecond scintillation-induced variability survey, MASIV, of the northern sky (decl. > 0degrees) at 4.9 GHz with the VLA. Our objective is to construct a sample of 100 to 150 scintillating extragalactic sources with which to examine both the microarcsecond

  7. Heart Rate Variability for Early Detection of Cardiac Iron Deposition in Patients with Transfusion-Dependent Thalassemia

    Science.gov (United States)

    Silvilairat, Suchaya; Charoenkwan, Pimlak; Saekho, Suwit; Tantiworawit, Adisak; Phrommintikul, Arintaya; Srichairatanakool, Somdet; Chattipakorn, Nipon

    2016-01-01

    Background Iron overload cardiomyopathy remains the major cause of death in patients with transfusion-dependent thalassemia. Cardiac T2* magnetic resonance imaging is costly yet effective in detecting cardiac iron accumulation in the heart. Heart rate variability (HRV) has been used to evaluate cardiac autonomic function and is depressed in cases of thalassemia. We evaluated whether HRV could be used as an indicator for early identification of cardiac iron deposition. Methods One hundred and one patients with transfusion-dependent thalassemia were enrolled in this study. The correlation between recorded HRV and hemoglobin, non-transferrin bound iron (NTBI), serum ferritin and cardiac T2* were evaluated. Results The median age was 18 years (range 8–59 years). The patient group with a 5-year mean serum ferritin >5,000 ng/mL included significantly more homozygous β-thalassemia and splenectomized patients, had lower hemoglobin levels, and had more cardiac iron deposit than all other groups. Anemia strongly influenced all domains of HRV. After adjusting for anemia, neither serum ferritin nor NTBI impacted the HRV. However cardiac T2* was an independent predictor of HRV, even after adjusting for anemia. For receiver operative characteristic (ROC) curve analysis of cardiac T2* ≤20 ms, only mean ferritin in the last 12 months and the average of the standard deviation of all R-R intervals for all five-minute segments in the 24-hour recording were predictors for cardiac T2* ≤20 ms, with area under the ROC curve of 0.961 (p<0.0001) and 0.701 (p = 0.05), respectively. Conclusions Hemoglobin and cardiac T2* as significant predictors for HRV indicate that anemia and cardiac iron deposition result in cardiac autonomic imbalance. The mean ferritin in the last 12 months could be useful as the best indicator for further evaluation of cardiac risk. The ability of serum ferritin to predict cardiac risk is stronger than observed in other thalassemia cohorts. HRV might be a

  8. Results of phacoemulsification of cataract complicated by lens subluxation depending on the ring setting method

    Directory of Open Access Journals (Sweden)

    N. G. Zavgorodnjaja

    2015-02-01

    Full Text Available Actuality. Cataract extraction complicated by zonular weakness remains one of the urgent problems of eye microsurgery. Aim. To increase the efficiency of cataract surgery complicated by lens subluxation through comparative analysis of frequency and structure of intra- and postoperative complications, as well as the functional results of surgical treatment of patients depending on the ring setting method. Methods and results. 91 patients (93 eyes were examined, who were operated on complicated cataract, and were divided into 2 groups depending on the method of ring setting. Conclusion. It was established that the offered method of implant capsular ring gives the opportunity to reduce the length of patients’ treatment by 2,6 day, to decrease of 28,43% for complications, and also to avoid such heavy operating complications, as a vitreous prolapse, displacement of the eye lens fragments in a vitreous body, dug up capsule bag.

  9. A method to diagnose opioid dependence resulting from heroin versus prescription opioids using the Composite International Diagnostic Interview.

    Science.gov (United States)

    Potter, Jennifer S; Prather, Kristi; Kropp, Frankie; Byrne, Mimmie; Sullivan, C Rollynn; Mohamedi, Nadia; Copersino, Marc L; Weiss, Roger D

    2010-03-01

    Treatment research with opioid-dependent populations has not traditionally distinguished between those dependent on prescription opioids versus dependent upon heroin. Evidence suggests there is a substantial subpopulation of individuals with opioid dependence resulting largely or exclusively from prescription opioid use. Because this subpopulation may respond to treatment differently from heroin users, a method for discriminating DSM-IV opioid dependence due to prescription opioid use would provide more precision when examining this population. This paper describes an innovative method using a currently available diagnostic instrument, to diagnose DSM-IV opioid dependence and distinguish between dependence resulting from prescription opioids versus dependence upon heroin.

  10. Exploring 100+ Year Variability with DASCH: Statistical Methods and Recent Results.

    Science.gov (United States)

    Miller, George Franklin; Grindlay, Jonathan E.; Los, Edward

    2014-06-01

    The Digital Access to a Sky Century at Harvard (DASCH) project is currently digitizing the roughly 500,000 photographic plates maintained by the Harvard College Observatory. The Harvard plate collection covers each point of the sky roughly 500 to 3000 times from 1885 to 1992, with limiting magnitudes ranging from B=14-18 mag and photometric accuracy within ±0.1 mag. Production scanning (roughly 400 plates/day) is proceeding in Galactic coordinates from the North Galactic Pole and is currently at roughly 40 degrees galactic latitude. The vastness of these data makes DASCH unique in its ability to systematically study variability on decade-long time scales across the entire sky. We are developing new statistical mining techniques to predictively identify the many classes of stellar variability and explore their long-term behavior, as well as discover new unusual cases/classes of variability. Most recently, we are working to implement wavelet-based algorithms into our mining routines, better allowing us to analyze localized non-periodic signals. Here we report on the progress of our mining and machine learning routines, as well as share several of the exciting new discoveries that are being made with DASCH. We gratefully acknowledge support from NSF grants AST-0407380, AST-0909073 and AST-1313370.

  11. VISTA VARIABLES IN THE VíA LÁCTEA (VVV: FIRST RESULTS AND PERSPECTIVES

    Directory of Open Access Journals (Sweden)

    R. K. Saito

    2011-01-01

    Full Text Available VISTA Variables in the Vía Láctea (VVV es un survey público de la ESO para el estudio en el infrarrojo cercano de objectos variables del bulbo de la Vía Láctea y de una sección adyacente del plano del disco. El survey empleará 1929 horas de observaciones con el telescopio de 4 m VISTA durante cinco años (2010-2014, abarcando -109 fuentes puntuales en una área de 520 grados2. A continuación se muestran los primeros resultados obtenidos por el VVV Survey, así como una visión de las posibilidades para el uso de un atlas profundo en cinco bandas en el infrarrojo cercano y un catálogo de más de 106 fuentes variables. Esperamos utilizar los datos para encontrar tránsitos planetarios en estrellas de secuencia principal de tipo tardío. Se discuten tambián la búiqueda de planetas y las futuras observaciones de seguimiento.

  12. Magnetohydrodynamic dissipative flow across the slendering stretching sheet with temperature dependent variable viscosity

    Science.gov (United States)

    Jayachandra Babu, M.; Sandeep, N.; Ali, M. E.; Nuhait, Abdullah O.

    The boundary layer flow across a slendering stretching sheet has gotten awesome consideration due to its inexhaustible pragmatic applications in nuclear reactor technology, acoustical components, chemical and manufacturing procedures, for example, polymer extrusion, and machine design. By keeping this in view, we analyzed the two-dimensional MHD flow across a slendering stretching sheet within the sight of variable viscosity and viscous dissipation. The sheet is thought to be convectively warmed. Convective boundary conditions through heat and mass are employed. Similarity transformations used to change over the administering nonlinear partial differential equations as a group of nonlinear ordinary differential equations. Runge-Kutta based shooting technique is utilized to solve the converted equations. Numerical estimations of the physical parameters involved in the problem are calculated for the friction factor, local Nusselt and Sherwood numbers. Viscosity variation parameter and chemical reaction parameter shows the opposite impact to each other on the concentration profile. Heat and mass transfer Biot numbers are helpful to enhance the temperature and concentration respectively.

  13. Time-dependent excitation and ionization modelling of absorption-line variability due to GRB 080310

    CERN Document Server

    Vreeswijk, P M; Raassen, A J J; Smette, A; De Cia, A; Woźniak, P R; Fox, A J; Vestrand, W T; Jakobsson, P

    2012-01-01

    We model the time-variable absorption of FeII, FeIII, SiII, CII and CrII detected in UVES spectra of GRB 080310, with the afterglow radiation exciting and ionizing the interstellar medium in the host galaxy at a redshift of z=2.42743. To estimate the rest-frame afterglow brightness as a function of time, we use a combination of the optical VRI photometry obtained by the RAPTOR-T telescope array -- which are presented in this paper -- and Swift's X-Ray Telescope observations. Excitation alone, which has been successfully applied for a handful of other GRBs, fails to describe the observed column-density evolution in the case of GRB 080310. Inclusion of ionization is required to explain the column-density decrease of all observed FeII levels (including the ground state 6D9/2) and increase of the FeIII 7S3 level. The large population of ions in this latter level (up to 10% of all FeIII) can only be explained through ionization of FeII, whereby a large fraction of the ionized FeII ions -- we calculate 31% using th...

  14. Spatio-temporal dependencies between hospital beds, physicians and health expenditure using visual variables and data classification in statistical table

    Directory of Open Access Journals (Sweden)

    Medyńska-Gulij Beata

    2016-06-01

    Full Text Available This paper analyses the use of table visual variables of statistical data of hospital beds as an important tool for revealing spatio-temporal dependencies. It is argued that some of conclusions from the data about public health and public expenditure on health have a spatio-temporal reference. Different from previous studies, this article adopts combination of cartographic pragmatics and spatial visualization with previous conclusions made in public health literature. While the significant conclusions about health care and economic factors has been highlighted in research papers, this article is the first to apply visual analysis to statistical table together with maps which is called previsualisation.

  15. Studies of Hot Photoluminescence in Plasmonically Coupled Silicon via Variable Energy Excitation and Temperature-Dependent Spectroscopy

    Science.gov (United States)

    2015-01-01

    By integrating silicon nanowires (∼150 nm diameter, 20 μm length) with an Ω-shaped plasmonic nanocavity, we are able to generate broadband visible luminescence, which is induced by high order hybrid nanocavity-surface plasmon modes. The nature of this super bandgap emission is explored via photoluminescence spectroscopy studies performed with variable laser excitation energies (1.959 to 2.708 eV) and finite difference time domain simulations. Furthermore, temperature-dependent photoluminescence spectroscopy shows that the observed emission corresponds to radiative recombination of unthermalized (hot) carriers as opposed to a resonant Raman process. PMID:25120156

  16. Spatio-temporal dependencies between hospital beds, physicians and health expenditure using visual variables and data classification in statistical table

    Science.gov (United States)

    Medyńska-Gulij, Beata; Cybulski, Paweł

    2016-06-01

    This paper analyses the use of table visual variables of statistical data of hospital beds as an important tool for revealing spatio-temporal dependencies. It is argued that some of conclusions from the data about public health and public expenditure on health have a spatio-temporal reference. Different from previous studies, this article adopts combination of cartographic pragmatics and spatial visualization with previous conclusions made in public health literature. While the significant conclusions about health care and economic factors has been highlighted in research papers, this article is the first to apply visual analysis to statistical table together with maps which is called previsualisation.

  17. Why should we keep measuring zenital dependence of muon flux? Results obtained at Campinas (SP) BR

    CERN Document Server

    Daniel, B; Nunes, M; Vieira, T V; Kemp, E

    2013-01-01

    The zenital dependence of muon flux which reaches the earth's surface is well known as proportional to cos^n(\\theta). Generally, for practical purposes and simplicity in calculations, n is taken as 2. However, compilations of measurements show dependence on the geographical location of the experiments as well as the muons energy range. Since analytical solutions appear to be increasingly less necessary because of the higher accessibility to low cost computational power, accurate and precise determination of the value of the exponent n, under different conditions, can be useful in the necessary calculations to estimate signals and backgrounds, either for terrestrial and underground experiments. In this work we discuss a method for measuring n using a simple muon telescope and the results obtained for measurements taken at Campinas (SP), Brazil. After validation of the method, we intend to extend the measurements for different geographic locations due to the simplicity of the method, and thus collect more value...

  18. Testing in a Random Effects Panel Data Model with Spatially Correlated Error Components and Spatially Lagged Dependent Variables

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    Ming He

    2015-11-01

    Full Text Available We propose a random effects panel data model with both spatially correlated error components and spatially lagged dependent variables. We focus on diagnostic testing procedures and derive Lagrange multiplier (LM test statistics for a variety of hypotheses within this model. We first construct the joint LM test for both the individual random effects and the two spatial effects (spatial error correlation and spatial lag dependence. We then provide LM tests for the individual random effects and for the two spatial effects separately. In addition, in order to guard against local model misspecification, we derive locally adjusted (robust LM tests based on the Bera and Yoon principle (Bera and Yoon, 1993. We conduct a small Monte Carlo simulation to show the good finite sample performances of these LM test statistics and revisit the cigarette demand example in Baltagi and Levin (1992 to illustrate our testing procedures.

  19. A new method for obtaining sharp compound Poisson approximation error estimates for sums of locally dependent random variables

    CERN Document Server

    Boutsikas, Michael V; 10.3150/09-BEJ201

    2010-01-01

    Let $X_1,X_2,...,X_n$ be a sequence of independent or locally dependent random variables taking values in $\\mathbb{Z}_+$. In this paper, we derive sharp bounds, via a new probabilistic method, for the total variation distance between the distribution of the sum $\\sum_{i=1}^nX_i$ and an appropriate Poisson or compound Poisson distribution. These bounds include a factor which depends on the smoothness of the approximating Poisson or compound Poisson distribution. This "smoothness factor" is of order $\\mathrm{O}(\\sigma ^{-2})$, according to a heuristic argument, where $\\sigma ^2$ denotes the variance of the approximating distribution. In this way, we offer sharp error estimates for a large range of values of the parameters. Finally, specific examples concerning appearances of rare runs in sequences of Bernoulli trials are presented by way of illustration.

  20. Including long-range dependence in integrate-and-fire models of the high interspike-interval variability of cortical neurons.

    Science.gov (United States)

    Jackson, B Scott

    2004-10-01

    Many different types of integrate-and-fire models have been designed in order to explain how it is possible for a cortical neuron to integrate over many independent inputs while still producing highly variable spike trains. Within this context, the variability of spike trains has been almost exclusively measured using the coefficient of variation of interspike intervals. However, another important statistical property that has been found in cortical spike trains and is closely associated with their high firing variability is long-range dependence. We investigate the conditions, if any, under which such models produce output spike trains with both interspike-interval variability and long-range dependence similar to those that have previously been measured from actual cortical neurons. We first show analytically that a large class of high-variability integrate-and-fire models is incapable of producing such outputs based on the fact that their output spike trains are always mathematically equivalent to renewal processes. This class of models subsumes a majority of previously published models, including those that use excitation-inhibition balance, correlated inputs, partial reset, or nonlinear leakage to produce outputs with high variability. Next, we study integrate-and-fire models that have (nonPoissonian) renewal point process inputs instead of the Poisson point process inputs used in the preceding class of models. The confluence of our analytical and simulation results implies that the renewal-input model is capable of producing high variability and long-range dependence comparable to that seen in spike trains recorded from cortical neurons, but only if the interspike intervals of the inputs have infinite variance, a physiologically unrealistic condition. Finally, we suggest a new integrate-and-fire model that does not suffer any of the previously mentioned shortcomings. By analyzing simulation results for this model, we show that it is capable of producing output

  1. Treatment utilization and barriers to treatment: Results of a survey of dependent methamphetamine users

    Directory of Open Access Journals (Sweden)

    Lee Nicole K

    2011-02-01

    Full Text Available Abstract Background Australia has one of the highest rates of methamphetamine use in the world; however, treatment access for methamphetamine is comparatively low. This descriptive study aimed to identify patterns of treatment utilization and perceived barriers to accessing treatment among dependent methamphetamine users in the hope that such information will enable services to more appropriately respond to this group. Methods One hundred and twenty-six methamphetamine users who had a current or past history of methamphetamine dependence were interviewed about their experiences of, and perceived barriers to, treatment. Results Treatment utilization among methamphetamine users was reportedly low. One of the main reasons cited for not accessing treatment was that methamphetamine users did not perceive their drug use to be a problem (despite apparent levels of dependence. Self-detoxification with the use of other licit and illicit drugs was high among this group. Participants identified a lack of confidence in the ability of treatment services to address methamphetamine dependence and the 'opiate-centric' nature of treatment services as significant blocks to treatment entry. Suggestions for improvement by participants included operating specialist services for methamphetamine users, placing an emphasis on responsiveness and routinely involving case management services for this group. Discussion and Conclusions To improve service delivery, treatment services should reorient their services to better address the needs of methamphetamine users by making small changes such as specific opening times for methamphetamine users or using a dedicated space for methamphetamine treatment. Alternative options such as online treatments and specialist methamphetamine clinics should be considered for methamphetamine users.

  2. Stability results for backward parabolic equations with time-dependent coefficients

    Science.gov (United States)

    Nho Hào, Dinh; Van Duc, Nguyen

    2011-02-01

    Let H be a Hilbert space with the norm || sdot || and A(t) (0 Dokl. Akad. Nauk SSSR 114 1162-5), and Agmon and Nirenberg (1963 Commun. Pure Appl. Math. 16 121-239). Our regularization method with a priori and a posteriori parameter choice yields error estimates of Hölder type. This is the only result when a regularization method for backward parabolic equations with time-dependent coefficients provides a convergence rate. Dedicated to Professor Rudolf Gorenflo on the occasion of his 80th birthday.

  3. Chemical variability and biological activities of Brassica rapa var. rapifera parts essential oils depending on geographic variation and extraction technique.

    Science.gov (United States)

    Saka, Boualem; Djouahri, Abderrahmane; Djerrad, Zineb; Souhila, Terfi; Aberrane, Sihem; Sabaou, Nasserdine; Baaliouamer, Aoumeur; Boudarene, Lynda

    2017-02-01

    In the present work, the Brassica rapa var. rapifera parts essential oils and their antioxidant and antimicrobial activities were investigated for the first time depending on geographic origin and extraction technique. GC and GC-MS analyses showed several constituents, including alcohols, aldehydes, esters, ketones, norisoprenoids, terpenic, nitrogen and sulphur compounds, totalizing 38 and 41 compounds in leaves and root essential oils, respectively. Nitrogen compounds were the main volatiles in leaves essential oils and sulphur compounds were the main volatiles in root essential oils. Qualitative and quantitative differences were found among B. rapa var. rapifera parts essential oils collected from different locations and extracted by hydrodistillation (HD) and microwave-assisted hydrodistillation (MAHD) techniques. Furthermore, our findings showed a high variability for both antioxidant and antimicrobial activities. The highlighted variability reflects the high impact of plant part, geographic variation and extraction technique on chemical composition and biological activities, which led to conclude that we should select essential oils to be investigated carefully depending on these factors, in order to isolate the bioactive components or to have the best quality of essential oil in terms of biological activities and preventive effects in food. This article is protected by copyright. All rights reserved.

  4. Insulin-dependent glucose metabolism in dairy cows with variable fat mobilization around calving.

    Science.gov (United States)

    Weber, C; Schäff, C T; Kautzsch, U; Börner, S; Erdmann, S; Görs, S; Röntgen, M; Sauerwein, H; Bruckmaier, R M; Metges, C C; Kuhla, B; Hammon, H M

    2016-08-01

    clamps, pp nonesterified fatty acid concentrations did not reach the ap levels. The study demonstrated a minor influence of different degrees of body fat mobilization on insulin metabolism in cows during the transition period. The distinct decrease in the glucose-dependent release of insulin pp is the most striking finding that explains the impaired insulin action after calving, but does not explain differences in body fat mobilization between HLFC and LLFC cows.

  5. Interval Management with Spacing to Parallel Dependent Runways (IMSPIDR) Experiment and Results

    Science.gov (United States)

    Baxley, Brian T.; Swieringa, Kurt A.; Capron, William R.

    2012-01-01

    An area in aviation operations that may offer an increase in efficiency is the use of continuous descent arrivals (CDA), especially during dependent parallel runway operations. However, variations in aircraft descent angle and speed can cause inaccuracies in estimated time of arrival calculations, requiring an increase in the size of the buffer between aircraft. This in turn reduces airport throughput and limits the use of CDAs during high-density operations, particularly to dependent parallel runways. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR) concept uses a trajectory-based spacing tool onboard the aircraft to achieve by the runway an air traffic control assigned spacing interval behind the previous aircraft. This paper describes the first ever experiment and results of this concept at NASA Langley. Pilots flew CDAs to the Dallas Fort-Worth airport using airspeed calculations from the spacing tool to achieve either a Required Time of Arrival (RTA) or Interval Management (IM) spacing interval at the runway threshold. Results indicate flight crews were able to land aircraft on the runway with a mean of 2 seconds and less than 4 seconds standard deviation of the air traffic control assigned time, even in the presence of forecast wind error and large time delay. Statistically significant differences in delivery precision and number of speed changes as a function of stream position were observed, however, there was no trend to the difference and the error did not increase during the operation. Two areas the flight crew indicated as not acceptable included the additional number of speed changes required during the wind shear event, and issuing an IM clearance via data link while at low altitude. A number of refinements and future spacing algorithm capabilities were also identified.

  6. Relationship between leukoaraiosis, carotid intima-media thickness and intima-media thickness variability: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Lucatelli, Pierleone [University of Rome la Sapienza, Department of Radiology, Rome (Italy); Raz, Eytan [New York University Langone Medical Center, Department of Radiology, New York, NY (United States); Saba, Luca [Azienda Ospedaliero Universitaria, Department of Radiology, di Cagliari - Polo di Monserrato, Cagliari (Italy); Argiolas, Giovanni Maria; Siotto, Paolo [Azienda Ospedaliera Brotzu, Department of Radiology, Cagliari (Italy); Montisci, Roberto [Azienda Ospedaliero Universitaria, Department of Vascular Surgery, di Cagliari - Polo di Monserrato, Cagliari (Italy); Wintermark, Max [University of Virginia, Department of Radiology, Neuroradiology Division, 1215 Lee Street-New Hospital, PO Box 800170, Charlottesville, VA (United States); King, Kevin S. [University of Texas Southwestern Medical Center, Department of Radiology, Dallas, TX (United States); Molinari, Filippo [Politecnico di Torino, Biolab, Department of Electronics, Torino (Italy); Ikeda, Nobutaka [Toho University Ohashi Medical Center, Division of Cardiovascular Medicine, Tokyo (Japan); Suri, Jasjit S. [AtheroPoint trademark LLC, Diagnostic and Monitoring Division, Roseville, CA (United States); University of Idaho, Department of Electrical Engineering, Pocatello, ID (United States)

    2016-12-15

    To assess the relationship between the degree of leukoaraiosis (LA), carotid intima-media thickness (IMT) and intima-media thickness variability (IMTV). Sixty-one consecutive patients, who underwent a brain MRI examination and a carotid artery ultrasound, were included in this retrospective study, which conformed with the Declaration of Helsinki. Written informed consent was waived. In each patient, right/left carotid arteries and brain hemispheres were assessed using automated software for IMT, IMTV and LA volume. The mean hemispheric LA volume was 2,224 mm{sup 3} (SD 2,702 mm{sup 3}) and there was no statistically significant difference in LA volume between the right and left hemispheres (p value = 0.628). The mean IMT and IMTV values were 0.866 mm (SD 0.170) and 0.143 mm (SD 0.100), respectively, without significant differences between the right and left sides (p values 0.733 and 0.098, respectively). The correlation coefficient between IMTV and LA volume was 0.41 (p value = 0.0001), and 0.246 (p value = 0.074) between IMT and LA volume. IMTV significantly correlates with LA volume. Further studies are warranted to verify whether this parameter can be used clinically as a marker of cerebrovascular risk. (orig.)

  7. Temperature and salinity variability in the Greek Seas based on POSEIDON stations time series: preliminary results

    Directory of Open Access Journals (Sweden)

    D. VELAORAS

    2013-07-01

    Full Text Available Temperature and salinity time series provided by three POSEIDON monitoring stations (buoys are examined in order to study the seasonal and interannual variability of the water mass characteristics. The sites at Athos (North Aegean Sea, E1M3A (Central Cretan Sea and Pylos (Eastern Ionian Sea were chosen, as these buoys provide measurements at various depths, while they represent 3 major basins respectively. The study of the T and S characteristics reveals important seasonal changes and highlights the particular characteristics of each basin. Dense water production in the Northern Aegean is found to be hindered by the presence of the surface Black Sea Water (BSW mass. On the other hand, the intermediate water mass in the Cretan Sea is shown to be ventilated during the winter season. A significant temperature and salinity increase has been monitored over both the Central Cretan and Eastern Ionian Seas starting from the middle of 2008 and 2009 respectively. This could possibly be attributed to changes in the intermediate water masses of the Eastern Mediterranean, without ruling out the possibility of water mass exchanges between the two basins.

  8. Operation results of Wertheim-Meig. Analysis of some variables (1989-2009.

    Directory of Open Access Journals (Sweden)

    Rafael E. Pérez Castro

    2011-06-01

    Full Text Available A retrospective cross-sectional study was made to 63 patients operated with the surgical technique Wertheim-Meig having cervical cancer in stage I (1A2 and 1b1 during the corresponding period to the decade (1989-2009 in the University General Hospital Camilo Cienfuegos, with the objective to determine some factors associated to this pathology , so as the morbidity of this technique. The studied group was conformed by 63 patients who had the inclusion requirements taking into consideration the stages (t1a2, T1b1 from the total of patients having a cervical cancer. The HC was checked in a retrospective way collecting variables in a form such as: age groups, clinical stage, complications and survival, arriving to the following conclusions: the highest incidence of cervical cancer was in third decade of life (31 to 40 years. As a risk factor was: having sex at 17 years old or less than this age. It was very significant. Postoperative complications were minimum. It was found a 92% of survival, 2 recurrence (3.1%, 4 deaths (6.3% and a free interval diseases of 93.6%.

  9. Methods for Minimization and Management of Variability in Long-Term Groundwater Monitoring Results

    Science.gov (United States)

    2015-12-01

    statistical analyses. A balanced dataset based on analytical results for each planned primary sample: 480 total samples Two demonstration sites... balanced dataset of analytical results from 480 groundwater samples based on analytical results for each planned primary sample: two demonstration...the peer review analyst of the staff chemist , the department supervisor, and finally the data entry personnel. The laboratory report will be

  10. Combined Prediction Model of Death Toll for Road Traffic Accidents Based on Independent and Dependent Variables

    Science.gov (United States)

    Zhong-xiang, Feng; Shi-sheng, Lu; Wei-hua, Zhang; Nan-nan, Zhang

    2014-01-01

    In order to build a combined model which can meet the variation rule of death toll data for road traffic accidents and can reflect the influence of multiple factors on traffic accidents and improve prediction accuracy for accidents, the Verhulst model was built based on the number of death tolls for road traffic accidents in China from 2002 to 2011; and car ownership, population, GDP, highway freight volume, highway passenger transportation volume, and highway mileage were chosen as the factors to build the death toll multivariate linear regression model. Then the two models were combined to be a combined prediction model which has weight coefficient. Shapley value method was applied to calculate the weight coefficient by assessing contributions. Finally, the combined model was used to recalculate the number of death tolls from 2002 to 2011, and the combined model was compared with the Verhulst and multivariate linear regression models. The results showed that the new model could not only characterize the death toll data characteristics but also quantify the degree of influence to the death toll by each influencing factor and had high accuracy as well as strong practicability. PMID:25610454

  11. Investigation of spatial resolution dependent variability in transcutaneous oxygen saturation using point spectroscopy system

    Science.gov (United States)

    Philimon, Sheena P.; Huong, Audrey K. C.; Ngu, Xavier T. I.

    2017-08-01

    This paper aims to investigate the variation in one’s percent mean transcutaneous oxygen saturation (StO2) with differences in spatial resolution of data. This work required the knowledge of extinction coefficient of hemoglobin derivatives in the wavelength range of 520 - 600 nm to solve for the StO2 value via an iterative fitting procedure. A pilot study was conducted on three healthy subjects with spectroscopic data collected from their right index finger at different arbitrarily selected distances. The StO2 value estimated by Extended Modified Lambert Beer (EMLB) model revealed a higher mean StO2 of 91.1 ± 1.3% at a proximity distance of 30 mm compared to 60.83 ± 2.8% at 200 mm. The results showed a high correlation between data spatial resolution and StO2 value, and revealed a decrease in StO2 value as the sampling distance increased. The preliminary findings from this study contribute to the knowledge of the appropriate distance range for consistent and high repeatability measurement of skin oxygenation.

  12. Assay-dependent variability of serum insulin concentrations: a comparison of eight assays.

    Science.gov (United States)

    Tohidi, Maryam; Arbab, Parvaneh; Ghasemi, Asghar

    2017-04-01

    Although insulin measurement is essential for both clinical and research purposes, there is currently no reference method for insulin assays. The aim of this study was to compare results of serum insulin determined by a number of commercially available assays. We compared eight insulin assays by analyzing 165 serum samples. Assays included two chemiluminescence (Roche and DiaSorin), four ELISA (Tosoh, Mercodia, Monobind, and Diametra), and two IRMA (Izotop and BioSource) methods. Each assay was compared with the mean of all assay methods and Bland-Altman difference plots were used to measure agreement between each assay and overall mean. Least squared perpendicular distance regression analysis (Deming's method) was used to calculate slope and intercept for bias and also for each assay vs. mean of eight assays. Findings showed that the lowest and highest median insulin concentrations varied by a factor of 1.8. Maximum and minimum correlations with mean of assays were observed for Roche (0.992) and BioSource (0.844), respectively. Significant bias was observed in six assays. In pairwise comparisons of different assays, the highest and least mean differences were 7.78 μU/mL and -0.14 μU/mL, respectively. In conclusion, serum insulin measurement with different assays showed a maximum of 1.8-fold difference, a point that should be taken into consideration in the interpretation of circulating insulin levels in both clinical and research fields.

  13. Combined Prediction Model of Death Toll for Road Traffic Accidents Based on Independent and Dependent Variables

    Directory of Open Access Journals (Sweden)

    Feng Zhong-xiang

    2014-01-01

    Full Text Available In order to build a combined model which can meet the variation rule of death toll data for road traffic accidents and can reflect the influence of multiple factors on traffic accidents and improve prediction accuracy for accidents, the Verhulst model was built based on the number of death tolls for road traffic accidents in China from 2002 to 2011; and car ownership, population, GDP, highway freight volume, highway passenger transportation volume, and highway mileage were chosen as the factors to build the death toll multivariate linear regression model. Then the two models were combined to be a combined prediction model which has weight coefficient. Shapley value method was applied to calculate the weight coefficient by assessing contributions. Finally, the combined model was used to recalculate the number of death tolls from 2002 to 2011, and the combined model was compared with the Verhulst and multivariate linear regression models. The results showed that the new model could not only characterize the death toll data characteristics but also quantify the degree of influence to the death toll by each influencing factor and had high accuracy as well as strong practicability.

  14. Analysis of laser speckle contrast images variability using a novel empirical mode decomposition: comparison of results with laser Doppler flowmetry signals variability.

    Science.gov (United States)

    Humeau-Heurtier, Anne; Abraham, Pierre; Mahe, Guillaume

    2015-02-01

    Laser Doppler flowmetry (LDF) and laser speckle contrast imaging (LSCI) have emerged as noninvasive optical modalities to monitor microvascular blood flow. Many studies proposed to extract physiological information from LDF by analyzing signals variability. By opposition, such analyses for LSCI data have not been conducted yet. We propose to analyze LSCI variability using a novel data-driven method: the complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN). CEEMDAN is suitable for nonlinear and nonstationary data and leads to intrinsic mode functions (IMFs). It is based on the ensemble empirical mode decomposition (EEMD) which relies on empirical mode decomposition (EMD). In our work the average frequencies of LSCI IMFs given by CEEMDAN are compared with the ones given by EMD and EEMD. Moreover, LDF signals acquired simultaneously to LSCI data are also processed with CEEMDAN, EMD and EEMD. We show that the average frequencies of IMFs given by CEEMDAN depend on the signal-to-noise ratio (SNR) used in the computation but, for a given SNR, the average frequencies found for LSCI are close to the ones obtained for LDF. By opposition, EEMD leads to IMFs with frequencies that do not vary much when the SNR level is higher than a threshold. The new CEEMDAN algorithm has the advantage of achieving a complete decomposition with no error in the reconstruction but our study suggests that further work is needed to gain knowledge in the adjustment of the added noise level. CEEMDAN, EMD and EEMD are data-driven methods that can provide a better knowledge of LSCI.

  15. ANALYSIS OF THE DEPENDENCE OF THE E-LEARNING USAGE ON THE STUDY RESULTS

    Directory of Open Access Journals (Sweden)

    KUNCOVÁ, M.

    2015-03-01

    Full Text Available The main aim of this paper is to compare the study results of the selected subjects of the full time and combined forms of study at the study programme Economics and Management. This programme is offered at the College of Polytechnics Jihlava and covers two fields of study - Travel and Tourism, Finance and Management. The comparison is aimed at the results of the period before the start of the e-learning (2008 for full time students and 2010 for combined form with the year 2012 (after the e-learning implementation. The results from eight biggest subjects are tested via Chi-square test of independence. It should answer the question if the e-learning has had an impact on the study results and if it is possible to find dependence between results of two different types of study, two different years, two different study branches and two different subjects. The comparison has shown the differences of combined/full time students but we have not proved the influence of the e-learning on the evaluation.

  16. Three-dimensional carotid ultrasound segmentation variability dependence on signal difference and boundary orientation.

    Science.gov (United States)

    Chiu, Bernard; Krasinski, Adam; Spence, J David; Parraga, Grace; Fenster, Aaron

    2010-01-01

    Quantitative measurements of the progression (or regression) of carotid plaque burden are important in monitoring patients and evaluating new treatment options. We previously developed a quantitative metric to analyze changes in carotid plaque morphology from 3-D ultrasound (US) on a point-by-point basis. This method requires multiple segmentations of the arterial wall and lumen boundaries to obtain the local standard deviation (SD) of vessel-wall-plus-plaque thickness (VWT) so that t-tests could be used to determine whether a change in VWT is statistically significant. However, the requirement for multiple segmentations makes clinical trials laborious and time-consuming. Therefore, this study was designed to establish the relationship between local segmentation SD and local signal difference on the arterial wall and lumen boundaries. We propose metrics to quantify segmentation SD and signal difference on a point-by-point basis, and studied whether the signal difference at arterial wall or lumen boundaries could be used to predict local segmentation SD. The ability to predict the local segmentation SD could eliminate the need of repeated segmentations of a 2-D transverse image to obtain the local segmentation standard deviation, thereby making clinical trials less laborious and saving time. Six subjects involved in this study were associated with different degrees of atherosclerosis: three carotid stenosis subjects with mean plaque area >3 cm(2) and >60% carotid stenosis were involved in a clinical study evaluating the effect of atorvastatin, a cholesterol-lowering and plaque-stabilizing drug; and three subjects with carotid plaque area >0.5 cm(2) were subjects with moderate atherosclerosis. Our results suggest that when local signal difference is higher than 8 greyscale value (GSV), the local segmentation SD stabilizes at 0.05 mm and is thus predictable. This information provides a target value of local signal difference on the arterial boundaries that should be

  17. Genetic deletion of aquaporin-1 results in microcardia and low blood pressure in mouse with intact nitric oxide-dependent relaxation, but enhanced prostanoids-dependent relaxation.

    Science.gov (United States)

    Montiel, V; Leon Gomez, E; Bouzin, C; Esfahani, H; Romero Perez, M; Lobysheva, I; Devuyst, O; Dessy, C; Balligand, J L

    2014-02-01

    The water channels, aquaporins (AQPs) are key mediators of transcellular fluid transport. However, their expression and role in cardiac tissue is poorly characterized. Particularly, AQP1 was suggested to transport other molecules (nitric oxide (NO), hydrogen peroxide (H2O2)) with potential major bearing on cardiovascular physiology. We therefore examined the expression of all AQPs and the phenotype of AQP1 knockout mice (vs. wild-type littermates) under implanted telemetry in vivo, as well as endothelium-dependent relaxation in isolated aortas and resistance vessels ex vivo. Four aquaporins were expressed in wild-type heart tissue (AQP1, AQP7, AQP4, AQP8) and two aquaporins in aortic and mesenteric vessels (AQP1-AQP7). AQP1 was expressed in endothelial as well as cardiac and vascular muscle cells and co-segregated with caveolin-1. AQP1 knockout (KO) mice exhibited a prominent microcardia and decreased myocyte transverse dimensions despite no change in capillary density. Both male and female AQP1 KO mice had lower mean BP, which was not attributable to altered water balance or autonomic dysfunction (from baroreflex and frequency analysis of BP and HR variability). NO-dependent BP variability was unperturbed. Accordingly, endothelium-derived hyperpolarizing factor (EDH(F)) or NO-dependent relaxation were unchanged in aorta or resistance vessels ex vivo. However, AQP1 KO mesenteric vessels exhibited an increase in endothelial prostanoids-dependent relaxation, together with increased expression of COX-2. This enhanced relaxation was abrogated by COX inhibition. We conclude that AQP1 does not regulate the endothelial EDH or NO-dependent relaxation ex vivo or in vivo, but its deletion decreases baseline BP together with increased prostanoids-dependent relaxation in resistance vessels. Strikingly, this was associated with microcardia, unrelated to perturbed angiogenesis. This may raise interest for new inhibitors of AQP1 and their use to treat hypertrophic cardiac

  18. Assessment of the temperature variability at the snow-ground interface - concept and first results

    Science.gov (United States)

    Hiller, Clemens; Keuschnig, Markus; Hartmeyer, Ingo; Götz, Joachim

    2014-05-01

    Bottom temperatures of the winter snow cover (BTS) represent the thermal conditions at the snow-ground interface and serve as a proxy for local permafrost ocurrence. The BTS method has been used in numerous studies to investigate local permafrost evidence and to validate larger scale permafrost distribution models. However, former studies have shown a relatively strong scattering between single measurements indicating that BTS values are sensitive to further factors. In order to identify the spatial and temporal variability and mentioned sources of irritation and to better understand their influence we applied repeated BTS measurements on a small scale test site situated below the Maurerkogel (2990 m) nearby the Kitzsteinhorn, Hohe Tauern Range, Austria. The site (c. 2000 m2) shows fairly homogenous surface conditions in terms of roughness and morphometry (bedrock with thin layer of fine-grained talus, slightly inclined to N). The measurement setup consists of a BTS grid with a minimum spacing of 5 m. Four campaigns with a total of 94 measurements were carried out from March 2012 to April 2013. Universal Temperature Logger (UTL), snow profiles and meteorological data from automatic weather stations are used to interpret the BTS values. The standard deviations of BTS values for each campaign range between 0.4 and 0.9 °C. The mean BTS value within the overall period is -3.1 °C. The near surface temperature logger shows a mean temperature of -3.7 °C in 10 cm depth covering four campaign days. Both, the correlation between near surface temperatures and BTS values as well as the low standard deviation between the BTS values demonstrate the applicability of the method under appropriate conditions.

  19. Low-Frequency Variability in the Northern Hemisphere Winter: Geographical Distribution, Structure and Time-Scale Dependence.

    Science.gov (United States)

    Kushnir, Yochanan; Wallace, John M.

    1989-10-01

    Low-frequency variability in wintertime 500 mb height is examined, with emphasis on its structure, geographical distribution, and frequency dependence. A 39-year record of 500 mb geopotential height fields from the NMC analyses is time filtered to partition the fluctuations into frequency bands corresponding to periods of 10-60 days, 60-180 days and > 180 days. Winter is defined as the six month period November through April. Variance, teleconnectivity, and anisotropy fields, and selected loading vectors derived from orthogonal and oblique rotations of the eigenvectors of the temporal correlation matrix for each band are shown and discussed.The variability in all frequency bands exhibits substantial anistropy, with meridionally elongated features arranged as zonally oriented wave trains prevailing over the continents and zonally elongated features organized in the form of north-south oriented dipole patterns prevailing over the oceanic sectors of the hemisphere. The wave trains are most pronounced in the 10-60 day variability, while the dipoles are most pronounced at lower frequencies. Eastward energy dispersion is apparent in the wave trains, but there is no evidence of phase propagation.Most of the `teleconnection patterns' identified in previous studies appear among the more prominent loading vectors. However, in most cases the loading vectors occur in pairs, in which the two patterns are in spatial quadrature with one another and account for comparable fractions of the hemispherically integrated variance. It is argued that such patterns should be interpreted as basis functions that can be linearly combined to form a continuum of anisotropic structures. Evidence of the existence of discrete `modal structures' is found only in the interannual (> 180-day period) variability, where two patterns stand out clearly above the background continuum: the Pacific-North American (PNA) pattern and the North Atlantic Oscillation (NAO). These patterns leave clear imprints upon

  20. Spatial and temporal variability of Arctic summer sea-ice albedo and its dependence on meltwater hydraulics

    Science.gov (United States)

    Eicken, H.; Perovich, D. K.; Grenfell, T. C.; Richter-Menge, J. A.; Frey, K.

    2001-12-01

    Next to ice extent and thickness, the area-averaged albedo of the summer sea-ice cover is a key parameter in determining the large-scale heat exchange over the Arctic Ocean. Various remote sensing applications have yielded a substantial data base for the former two parameters, not least due to the efforts of the National Snow and Ice Data Center (NSIDC) over the past 25 years. In contrast, the spatial and temporal variability of Arctic summer sea-ice albedo is much less well described. Despite its importance (incl. for ice-albedo feedback processes), few if any large-scale sea-ice and global circulation models actually predict summer ice based on the underlying physical processes. Most models employ simple parameterization schemes instead. Remote sensing of surface ice albedo also faces substantial challenges, some of which still need to be addressed in more detail. Here, we report on albedo measurements completed over first- and multi-year sea ice in the summers of 1998, 2000 and 2001 in the North American at the SHEBA drifting ice camp and in fast ice near Barrow, Alaska. As has been established in a number of studies, spatial and temporal variability in summer sea-ice albedo is mostly determined by the areal extent of meltwater ponding at the ice surface. Given the importance of this process, a comprehensive ice hydrological program (meltwater distribution, surface topography, meltwater flow and discharge, ice permeability) has been carried out in conjunction with the optical measurements. Measurements demonstrate that Arctic summer sea-ice albedo is critically dependent on the hydrology of surface melt ponds, as controlled by meltwater production rate, ice permeability and topography. Both, remarkable short-term variability (a reduction of albedo by 43% within two days) as well as the seasonal evolution of the pond fraction and hence area-averaged albedo are forced by changes in pond water level on the order of a few centimeters. While some of these forcing

  1. Posture-Dependent Human 3He Lung Imaging in an Open Access MRI System: Initial Results

    CERN Document Server

    Tsai, L L; Li, C -H; Rosen, M S; Patz, S; Walsworth, R L

    2007-01-01

    The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized 3He MRI of the human lung, and most other common radiological imaging modalities including PET and CT, restrict subjects to lying horizontally, minimizing most gravitational effects. In this paper, we briefly review the motivation for posture-dependent studies of human lung function, and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized 3He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions, and potentially allows for complete rotation of the orientation of the imaging su...

  2. How you evaluate treatment results in low back pain patients depends on who the patient is

    DEFF Research Database (Denmark)

    Lauridsen, Henrik Hein

    2008-01-01

    How you evaluate treatment results in low back pain patients depends on who the patient is Lauridsen, HH 1*, Hartvigsen, J1,2, Manniche, C1,3, Korsholm, L1,4, Grunnet-Nilsson, N1 1.    Clinical Locomotion Science, Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark...... of an evaluative instrument in back pain patients is complicated because of lack of head-to-head comparisons of clinimetric properties of the various instruments. In addition, little is known about instrument behaviour in clinical subgroups. The objective of this study was to concurrently compare responsiveness...... and minimal clinically important differences (MCID) for commonly used pain scales and functional instruments in four subpopulations of LBP patients. Methods The Danish versions of the Oswestry Disability Index (ODI), the 23-item Roland Morris Disability Questionnaire (RMQ), the physical function and bodily...

  3. Association between Serum Uric Acid Levels and Sleep Variables: Results from the National Health and Nutrition Survey 2005–2008

    Directory of Open Access Journals (Sweden)

    R. Constance Wiener

    2012-01-01

    Full Text Available Sleep disordered breathing as well as high serum uric acid levels are independent risk factors for cardiovascular disease. However, studies evaluating the relationship between sleep-disordered breathing and hyperuricemia are limited. We examined the 2005–2008 National Health and Nutrition Examination survey's sleep variables and high serum uric acid among 6491 participants aged ≥20 years. The sleep variables included sleep duration, snoring, snorting, and daytime sleepiness. The main outcome was high serum uric acid level, defined as levels of serum uric acid >6.8 mg/dL in males and >6.0 mg/dL in females. We found that snoring more than 5 nights per week, daytime sleepiness, and an additive composite score of sleep variables were associated with high serum uric acid in the age- , sex-adjusted model and in a multivariable model adjusting for demographic and lifestyle/behavioral risk factors. The association was attenuated with the addition of variables related to clinical outcomes such as depression, diabetes, hypertension, and high-cholesterol levels. Our results indicate a positive relationship between sleep variables, including the presence of snoring, snorting, and daytime sleepiness, and high serum uric acid levels.

  4. Short-time Variability of Blazars via Non-linear, Time-dependent Synchrotron-Self Compton Radiative Losses

    CERN Document Server

    Röken, Christian; Schöneberg, Sebastian; Schuppan, Florian

    2016-01-01

    A leptonic one-zone model accounting for the radiation emission of blazars is presented. This model describes multiple successive injections of mono-energetic, ultra-relativistic, interacting electron populations, which are subjected to synchrotron and synchrotron-self Compton radiative losses. The electron number density is computed analytically by solving a time-dependent, relativistic transport equation. Moreover, the synchrotron and synchrotron-self Compton intensities as well as the corresponding total fluences are explicitly calculated. The lightcurves and fluences are plotted for realistic parameter values, showing that the model can simultaneously explain both the specific short-time variability in the flaring of blazars and the characteristic broad-band fluence behavior.

  5. Mesoscale variability in the Arabian Sea from HYCOM model results and observations: impact on the Persian Gulf Water path

    Science.gov (United States)

    L'Hégaret, P.; Duarte, R.; Carton, X.; Vic, C.; Ciani, D.; Baraille, R.; Corréard, S.

    2015-09-01

    The Arabian Sea and Sea of Oman circulation and water masses, subject to monsoon forcing, reveal a strong seasonal variability and intense mesoscale features. We describe and analyze this variability and these features, using both meteorological data (from ECMWF reanalyses), in situ observations (from the ARGO float program and the GDEM - Generalized Digital Environmental mode - climatology), satellite altimetry (from AVISO) and a regional simulation with a primitive equation model (HYCOM - the Hybrid Coordinate Ocean Model). The model and observations display comparable variability, and the model is then used to analyze the three-dimensional structure of eddies and water masses with higher temporal and spatial resolutions than the available observations. The mesoscale features are highly seasonal, with the formation of coastal currents, destabilizing into eddies, or the radiation of Rossby waves from the Indian coast. The mesoscale eddies have a deep dynamical influence and strongly drive the water masses at depth. In particular, in the Sea of Oman, the Persian Gulf Water presents several offshore ejection sites and a complex recirculation, depending on the mesoscale eddies. The associated mechanisms range from coastal ejection via dipoles, alongshore pulses due to a cyclonic eddy, to the formation of lee eddies downstream of Ra's Al Hamra. This water mass is also captured inside the eddies via several mechanisms, keeping high thermohaline characteristics in the Arabian Sea. The variations of the outflow characteristics near the Strait of Hormuz are compared with variations downstream.

  6. Estimation of spatial variability of lignite mine dumping ground soil properties using CPTu results

    Directory of Open Access Journals (Sweden)

    Bagińska Irena

    2016-03-01

    Full Text Available The paper deals with application of CPTu test results for the probabilistic modeling of dumping grounds. The statistical measures use results from 42 CPT test points located in the lignite mine dumping ground from the region of Central Europe. Both the tip resistance qc as well as local friction fs are tested. Based on the mean values and standard deviations of measured quantities the specific zones in the dumping site profile are distinguished. For three main zones standard deviations of linearly de-trended functions, distributions of normalized de-trended values for qc and fs are examined. Also the vertical scales of fluctuation for both measured quantities are estimated. The obtained result shows that lignite mine dumping site can be successfully described with the Random Field Theory. Additional use of fs values introduces supplementary statistical information.

  7. A DNA-based system for selecting and displaying the combined result of two input variables

    DEFF Research Database (Denmark)

    Liu, Huajie; Wang, Jianbang; Song, S

    2015-01-01

    Oligonucleotide-based technologies for biosensing or bio-regulation produce huge amounts of rich high-dimensional information. There is a consequent need for flexible means to combine diverse pieces of such information to form useful derivative outputs, and to display those immediately. Here we...... demonstrate this capability in a DNA-based system that takes two input numbers, represented in DNA strands, and returns the result of their multiplication, writing this as a number in a display. Unlike a conventional calculator, this system operates by selecting the result from a library of solutions rather...

  8. Potential fitting biases resulting from grouping data into variable width bins

    CERN Document Server

    Towers, S

    2012-01-01

    When reading peer-reviewed scientific literature describing any analysis of empirical data, it is natural and correct to proceed with the underlying assumption that experiments have made good faith efforts to ensure that their analyses yield unbiased results. However, particle physics experiments are expensive and time consuming to carry out, thus if an analysis has inherent bias (even if unintentional), much money and effort can be wasted trying to replicate or understand the results, particularly if the analysis is fundamental to our understanding of the universe. In this note we discuss the significant biases that can result from data binning schemes. As we will show, if data are binned such that they provide the best comparison to a particular (but incorrect) model, the resulting model parameter estimates when fitting to the binned data can be significantly biased, leading us to too often accept the model hypothesis when it is not in fact true. When using binned likelihood or least squares methods there i...

  9. The genetic variability of the Podolica cattle breed from the Gargano area. Preliminary results

    Directory of Open Access Journals (Sweden)

    Dario Cianci

    2010-01-01

    Full Text Available The Podolica cattle breed is autochthonous of Southern Italy and denoted by its particular rusticity. This study presents the preliminary results of the genetic characterization of the Podolica breed using DNA STR markers. A total of 20 microsatellite loci were analysed in 79 individuals reared in the Gargano area. Number of polymorphisms, allele fre- quencies, deviations from Hardy-Weinberg proportions, linkage disequilibrium between loci and genetic similarities between animals were calculated. The results showed a high deficiency of heterozygotes, the observed mean of het- erozygosis being 0.449, whereas the expected mean was 0.766. Many markers showed also deviations from the Hardy- Weinberg proportions and significant linkage disequilibrium between loci. However the genetic similarity within the pop- ulation was low (0.281 and the average number of alleles per locus was high (10, representing a high genetic vari- ability. In order to explain these results, a stratification of the breed in sub-populations with a high interior genetic homo- geneity but markedly differentiated one from each other could be hypothesized; this situation probably derived from non- random mating within each herd (consanguinity and from the lack of exchange of genetic material between the herds. A further study is needed on a wider sample and extending the analysis to FAO-ISAG microsatellite panel in order to con- firm this hypothesis. This could eventually provide the information necessary for the correct management of the repro- ductive schemes and for genomic traceability of meat production.

  10. Defective CFTR-dependent CREB activation results in impaired spermatogenesis and azoospermia.

    Directory of Open Access Journals (Sweden)

    Wen Ming Xu

    Full Text Available Cystic fibrosis (CF is the most common life-limiting recessive genetic disease among Caucasians caused by mutations of the cystic fibrosis transmembrane conductance regulator (CFTR with over 95% male patients infertile. However, whether CFTR mutations could affect spermatogenesis and result in azoospermia remains an open question. Here we report compromised spermatogenesis, with significantly reduced testicular weight and sperm count, and decreased cAMP-responsive element binding protein (CREB expression in the testes of CFTR knockout mice. The involvement of CFTR in HCO(3 (- transport and the expression of the HCO(3 (- sensor, soluble adenylyl cyclase (sAC, are demonstrated for the first time in the primary culture of rat Sertoli cells. Inhibition of CFTR or depletion of HCO(3 (- could reduce FSH-stimulated, sAC-dependent cAMP production and phosphorylation of CREB, the key transcription factor in spermatogenesis. Decreased CFTR and CREB expression are also observed in human testes with azoospermia. The present study reveals a previously undefined role of CFTR and sAC in regulating the cAMP-CREB signaling pathway in Sertoli cells, defect of which may result in impaired spermatogenesis and azoospermia. Altered CFTR-sAC-cAMP-CREB functional loop may also underline the pathogenesis of various CF-related diseases.

  11. Evolution of clinical features in possible DLB depending on FP-CIT SPECT result

    Science.gov (United States)

    Moreno, Emilio; Thomas, Alan; Inglis, Fraser; Tabet, Naji; Stevens, Tim; Whitfield, Tim; Aarsland, Dag; Rainer, Michael; Padovani, Alessandro

    2016-01-01

    Objective: To test the hypothesis that core and suggestive features in possible dementia with Lewy bodies (DLB) would vary in their ability to predict an abnormal dopamine transporter scan and therefore a follow-up diagnosis of probable DLB. A further objective was to assess the evolution of core and suggestive features in patients with possible DLB over time depending on the 123I-FP-CIT SPECT scan result. Methods: A total of 187 patients with possible DLB (dementia plus one core or one suggestive feature) were randomized to have dopamine transporter imaging or to follow-up without scan. DLB features were compared at baseline and at 6-month follow-up according to imaging results and follow-up diagnosis. Results: For the whole cohort, the baseline frequency of parkinsonism was 30%, fluctuations 29%, visual hallucinations 24%, and REM sleep behavior disorder 17%. Clinician-rated presence of parkinsonism at baseline was significantly (p = 0.001) more frequent and Unified Parkinson’s Disease Rating Scale (UPDRS) score at baseline was significantly higher (p = 0.02) in patients with abnormal imaging. There was a significant increase in UPDRS score in the abnormal scan group over time (p < 0.01). There was relatively little evolution of the rest of the DLB features regardless of the imaging result. Conclusions: In patients with possible DLB, apart from UPDRS score, there was no difference in the evolution of DLB clinical features over 6 months between cases with normal and abnormal imaging. Only parkinsonism and dopamine transporter imaging helped to differentiate DLB from non-DLB dementia. PMID:27511183

  12. Variable infiltration and river flooding resulting in changing groundwater quality - A case study from Central Europe

    Science.gov (United States)

    Miotliński, Konrad; Postma, Dieke; Kowalczyk, Andrzej

    2012-01-01

    SummaryThe changes in groundwater quality occurring in a buried valley aquifer following a reduction in groundwater exploitation and enhanced infiltration due to extensive flooding of the Odra River in 1997 were investigated. Long-time series data for the chemical composition of groundwater in a large well field for drinking water supply indicated the deterioration of groundwater quality in the wells capturing water from the flooded area, which had been intensively cultivated since the 1960s. Infiltration of flooded river water into the aquifer is suggested by an elevated chloride concentration, although salt flushing from the rewatered unsaturated zone due to the enhanced recharge event is much more feasible. Concomitantly with chloride increases in the concentrations of sulphate, ferrous iron, manganese, and nickel imply the oxidation of pyrite (FeS 2) which is abundant in the aquifer. The proton production resulting from pyrite oxidation is buffered by the dissolution of calcite, while the Ca:SO 4 stoichiometry of the groundwater indicates that pyrite oxidation coupled with nitrate reduction is the dominant process occurring in the aquifer. The pyritic origin of SO42- is confirmed by the sulphur isotopic composition. The resultant Fe 2+ increase induces Mn-oxide dissolution and the mobilisation of Ni 2+ previously adsorbed to Mn-oxide surfaces. The study has a major implication for groundwater quality prediction studies where there are considerable variations in water level associated with groundwater management and climate change issues.

  13. Statistical analysis of the inherent variability in the results of evolutionary debris models

    Science.gov (United States)

    Lidtke, Aleksander A.; Lewis, Hugh G.; Armellin, Roberto

    2017-04-01

    Space debris simulations, e.g. those performed by the Inter-Agency Debris Coordination Committee (Liou et al., 2013), showed that the number of objects in orbit is likely to increase. This study analyses the uncertainty in the results of space debris simulations performed using semi-stochastic models that necessitate the use of Monte Carlo simulations, which are often used by the Inter-Agency Debris Coordination Committee, amongst other studies. Statistics of the possible numbers of objects in orbit and collisions over the next 200 years are generated for the ;mitigation only; scenario using a sample of 25,000 Monte Carlo runs. Bootstraps on the mean, median, variance, skewness and kurtosis of these distributions are performed. It is shown that the distribution of the objects predicted to be on-orbit becomes log-normal as collisions occur, and that Monte Carlo samples larger than traditionally used are needed to capture the debris simulation uncertainty.

  14. Variable levels of tissue mosaicism can confound the interpretation of chromosomal microarray results from peripheral blood.

    Science.gov (United States)

    Pal, Chandni V; Eble, Tanya N; Burnside, Rachel D; Bi, Weimin; Patel, Ankita; Franco, Luis M

    2014-01-01

    Chromosomal microarray analysis (CMA) has significantly increased the ability to diagnose medical conditions caused by copy-number variation in the human genome. Given that the regions involved in copy-number abnormalities often encompass multiple genes, it has been common practice in recent years to compare the phenotypes of individuals with specific copy-number alterations identified by CMA, with the goal of identifying the critical regions for particular elements of a disease phenotype. It is rarely mentioned that this practice relies heavily on the assumption that the absence of mosaicism on CMA from a peripheral blood sample (the most common source of DNA in current clinical practice) reflects the absence of mosaicism in other tissues. We report here a case that violates that assumption. A 28-year-old male with Charcot-Marie-Tooth disease was found by CMA to have a duplication of 17p12 along with two other abnormalities: A duplication of 12p13.33 translocated to the long arm of chromosome 3 and an interstitial duplication of 12p11.23. The patient did not have any clinical features suggestive of 12p duplication syndrome. Chromosomal microarray analysis on skin fibroblasts revealed the duplications at 17p12 and 12p11.23, but not the terminal duplication of 12p13.33. FISH analysis on skin fibroblasts confirmed the presence of very low levels of mosaicism for the terminal 12p duplication. The case illustrates how the absence of mosaicism in blood is not always indicative of the absence of mosaicism in other tissues. Even in an era of high-throughput, highly accurate DNA-based tests, it is important to remember the limitations of testing before drawing conclusions about the relationship between a test results and a clinical phenotype.

  15. Restoration enhances wetland biodiversity and ecosystem service supply, but results are context-dependent: a meta-analysis.

    Science.gov (United States)

    Meli, Paula; Rey Benayas, José María; Balvanera, Patricia; Martínez Ramos, Miguel

    2014-01-01

    Wetlands are valuable ecosystems because they harbor a huge biodiversity and provide key services to societies. When natural or human factors degrade wetlands, ecological restoration is often carried out to recover biodiversity and ecosystem services (ES). Although such restorations are routinely performed, we lack systematic, evidence-based assessments of their effectiveness on the recovery of biodiversity and ES. Here we performed a meta-analysis of 70 experimental studies in order to assess the effectiveness of ecological restoration and identify what factors affect it. We compared selected ecosystem performance variables between degraded and restored wetlands and between restored and natural wetlands using response ratios and random-effects categorical modeling. We assessed how context factors such as ecosystem type, main agent of degradation, restoration action, experimental design, and restoration age influenced post-restoration biodiversity and ES. Biodiversity showed excellent recovery, though the precise recovery depended strongly on the type of organisms involved. Restored wetlands showed 36% higher levels of provisioning, regulating and supporting ES than did degraded wetlands. In fact, wetlands showed levels of provisioning and cultural ES similar to those of natural wetlands; however, their levels of supporting and regulating ES were, respectively, 16% and 22% lower than in natural wetlands. Recovery of biodiversity and of ES were positively correlated, indicating a win-win restoration outcome. The extent to which restoration increased biodiversity and ES in degraded wetlands depended primarily on the main agent of degradation, restoration actions, experimental design, and ecosystem type. In contrast, the choice of specific restoration actions alone explained most differences between restored and natural wetlands. These results highlight the importance of comprehensive, multi-factorial assessment to determine the ecological status of degraded, restored

  16. The HI Mass Function Derived from the 30% ALFALFA Survey: First Results and Environmental Dependence

    Science.gov (United States)

    Martin, Ann

    2010-01-01

    When complete, the ALFALFA survey catalog will cover 7000 square degrees and provide a catalog with 30,000 detections, improving our understanding of the density of HI in the local Universe and its environmental dependence. Following 585 observing runs with a total of 3400 hours of telescope time, observations for the ALFALFA survey are now 77% complete. Data reduction and catalog production has been completed for two large contiguous sections in the Virgo and anti-Virgo directions ( 1600 and 530 square degrees, respectively), and the ALFALFA survey now has the largest sample of blindly HI-selected galaxies. The regions analyzed here are 07h30ALFALFA Survey and contain on the order of 10,000 HI selected galaxies in a range of local environments, out to distances of 250 Mpc. In particular, this catalog contains 300 galaxies with log HI mass less than 8.0 solar masses, providing a robust determination of the low-mass end of the HI mass function presented here. Along with these preliminary results, we compare the HI mass function in the region containing the overdense Virgo cluster to that in the anti-Virgo direction, which includes the void in the foreground of the Pisces-Perseus supercluster. Finally, we discuss future improvements to this first HI mass function estimate from the ALFALFA survey. This work is partly supported by NSF grant AST-0607007 and the Brinson Foundation.

  17. How you evaluate treatment results in low back pain patients depends on who the patient is

    DEFF Research Database (Denmark)

    Lauridsen, Henrik Hein

    2009-01-01

    only or leg pain +/- LBP. Results RMQ was the most responsive instrument in primary and secondary sector patients with LBP only (SRM=0.5-1.4; ROC=0.75-0.94) whereas ODI and RMQ showed almost similar responsiveness in primary and secondary sector patients with leg pain (ODI: SRM = 0.4-0.9; ROC = 0.......76-0.89; RMQ: SRM = 0.3-0.9; ROC = 0.72-0.88). In improved patients, the RMQ was more responsive in primary and secondary sector patients and LBP only patients (SRM=1.3-1.7) while the RMQ and ODI were equally responsive in leg pain patients (SRM=1.3 and 1.2 respectively). All pain measures demonstrated almost...... in the subpopulations. Conclusions RMQ is suitable for measuring change in LBP only patients and both ODI and RMQ are suitable for LBP patients with concurrent leg pain irrespectively of patient entry point. The MCID is baseline score dependent but only in certain subpopulations. Relative change measured using the ODI...

  18. A Cautionary Tale on the Inclusion of Variable Posttranslational Modifications in Database-Dependent Searches of Mass Spectrometry Data.

    Science.gov (United States)

    Svozil, J; Baerenfaller, K

    2017-01-01

    Mass spectrometry-based proteomics allows in principle the identification of unknown target proteins of posttranslational modifications and the sites of attachment. Including a variety of posttranslational modifications in database-dependent searches of high-throughput mass spectrometry data holds the promise to gain spectrum assignments to modified peptides, thereby increasing the number of assigned spectra, and to identify potentially interesting modification events. However, these potential benefits come for the price of an increased search space, which can lead to reduced scores, increased score thresholds, and erroneous peptide spectrum matches. We have assessed here the advantages and disadvantages of including the variable posttranslational modifications methionine oxidation, protein N-terminal acetylation, cysteine carbamidomethylation, transformation of N-terminal glutamine to pyroglutamic acid (Gln→pyro-Glu), and deamidation of asparagine and glutamine. Based on calculations of local false discovery rates and comparisons to known features of the respective modifications, we recommend for searches of samples that were not enriched for specific posttranslational modifications to only include methionine oxidation, protein N-terminal acetylation, and peptide N-terminal Gln→pyro-Glu as variable modifications. The principle of the validation strategy adopted here can also be applied for assessing the inclusion of posttranslational modifications for differently prepared samples, or for additional modifications. In addition, we have reassessed the special properties of the ubiquitin footprint, which is the remainder of ubiquitin moieties attached to lysines after tryptic digest. We show here that the ubiquitin footprint often breaks off as neutral loss and that it can be distinguished from dicarbamidomethylation events.

  19. Results of scalp cooling during anthracycline containing chemotherapy depend on scalp skin temperature

    NARCIS (Netherlands)

    Komen, M.M.; Smorenburg, C.H.; Nortier, J.W.; Ploeg, T. van der; Hurk, C.J. van den; Hoeven, J.J. van der

    2016-01-01

    OBJECTIVES: The success of scalp cooling in preventing or reducing chemotherapy induced alopecia (CIA) is highly variable between patients undergoing similar chemotherapy regimens. A decrease of the scalp skin temperature seems to be an important factor, but data on the optimum temperature reached

  20. The OmegaWhite Survey for short period variable stars - II. An overview of results from the first four years

    Science.gov (United States)

    Toma, R.; Ramsay, G.; Macfarlane, S.; Groot, P. J.; Woudt, P. A.; Dhillon, V.; Jeffery, C. S.; Marsh, T.; Nelemans, G.; Steeghs, D.

    2016-11-01

    OmegaWhite is a wide-field, high cadence, synoptic survey targeting fields in the southern Galactic plane, with the aim of discovering short period variable stars. Our strategy is to take a series of 39 s exposures in the g band of a 1 deg2 of sky lasting 2 h using the OmegaCAM wide field imager on the VLT Survey Telescope (VST). We give an overview of the initial 4 yr of data which covers 134 deg2 and includes 12.3 million light curves. As the fields overlap with the VLT Survey Telescope Hα Photometric Survey of the Galactic plane and Bulge (VPHAS+), we currently have ugriHα photometry for ˜1/3 of our fields. We find that a significant fraction of the light curves have been affected by the diffraction spikes of bright stars sweeping across stars within a few dozen of pixels over the two hour observing time interval due to the alt-az nature of the VST. We select candidate variable stars using a variety of variability statistics, followed by a manual verification stage. We present samples of several classes of short period variables, including: an ultra compact binary, a DQ white dwarf, a compact object with evidence of a 100 min rotation period, three CVs, one eclipsing binary with an 85 min period, a symbiotic binary which shows evidence of a 31 min photometric period, and a large sample of candidate δ Sct type stars including one with a 9.3 min period. Our overall goal is to cover 400 deg2, and this study indicates we will find many more interesting short period variable stars as a result.

  1. Evaluation of drug dependent persons’ health on the basis of routine laboratory test results

    Directory of Open Access Journals (Sweden)

    Beata Łangowska-Grodzka

    2016-03-01

    Conclusion: The most commonly assessed biochemical changes of reference values observed above concerned total cholesterol, AST, ALT, GTP. Alcohol or opiate dependent persons had more often increased activity of GTP, AST and ALT than those addicted to amphetamine.

  2. Influence of some formulation variables on the optimization of pH-dependent, colon-targeted, sustained-release mesalamine microspheres.

    Science.gov (United States)

    El-Bary, Ahmed Abd; Aboelwafa, Ahmed A; Al Sharabi, Ibrahim M

    2012-03-01

    The aim of this work was to understand the influence of different formulation variables on the optimization of pH-dependent, colon-targeted, sustained-release mesalamine microspheres prepared by O/O emulsion solvent evaporation method, employing pH-dependent Eudragit S and hydrophobic pH-independent ethylcellulose polymers. Formulation variables studied included concentration of Eudragit S in the internal phase and the ratios between; internal to external phase, drug to Eudragit S and Eudragit S to ethylcellulose to mesalamine. Prepared microspheres were evaluated by carrying out in vitro release studies and determination of particle size, production yield, and encapsulation efficiency. In addition, morphology of microspheres was examined using optical and scanning electron microscopy. Emulsion solvent evaporation method was found to be sensitive to the studied formulation variables. Particle size and encapsulation efficiency increased by increasing Eudragit S concentration in the internal phase, ratio of internal to external phase, and ratio of Eudragit S to the drug. Employing Eudragit S alone in preparation of the microspheres is only successful in forming acid-resistant microspheres with pulsatile release pattern at high pH. Eudragit S and ethylcellulose blend microspheres were able to control release under acidic condition and to extend drug release at high pH. The stability studies carried out at 40°C/75% RH for 6 months proved the stability of the optimized formulation. From the results of this investigation, microencapsulation of mesalamine in microspheres using blend of Eudragit S and ethylcellulose could constitute a promising approach for site-specific and controlled delivery of drug in colon.

  3. Earthquake cycles on rate-state faults: how does recurrence interval and its variability depend on fault length?

    Science.gov (United States)

    Cattania, C.; Segall, P.

    2016-12-01

    The concept of earthquake cycles is often invoked when discussing seismic risk. However, large faults exhibit more complex behavior than periodic stick-slip cycles. Some events, such as the 2004 Parkfield earthquake, are delayed relative to the mean recurrence interval; in other cases, ruptures are larger or smaller than expected. In contrast, small earthquakes can be very predictable: locked patches surrounded by aseismic creep can rupture periodically in events with similar waveforms. We use numerical tools and ideas from fracture mechanics to study the factors determining recurrence interval (T), rupture size and their variability at different scales. T has been estimated by assuming a constant stress drop and stressing rate inversely proportional to fault length (D). However, Werner & Rubin (2013) found that an energy criterion better explains the scaling of T vs. D in numerical models: on faults loaded from below, full ruptures occur when the elastic energy release rate at the top of the fault reaches the fracture energy. We run simulations of seismic cycles on rate state faults including dynamic weakening from thermal pressurization. A fault composed of a velocity weakening part over a velocity strengthening one is loaded from below at constant slip rate. We find that T increases with thermal pressurization, and verify that the energy argument, modified to account for the fracture energy from thermal pressurization, provides a good estimate of T and its scaling with D. We suggest that the recurrence interval is determined by two timescales: the time required to accumulate sufficient elastic energy for full rupture (tf), and the nucleation time, controlled by the propagation of a creep front into the velocity weakening region (tn). Both timescales depend on fault length: tf increases with D, and tn decreases. The latter is due to faster afterslip in the velocity strengthening region on larger faults. If tn < tf, partial ruptures occur; for large faults, tn

  4. Detection of suspected placental invasion by MRI: Do the results depend on observer’ experience?

    Energy Technology Data Exchange (ETDEWEB)

    Alamo, Leonor, E-mail: leonor.alamo@chuv.ch [Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Anaye, Anass; Rey, Jannick; Denys, Alban [Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Bongartz, Georg [Universitätsspital Basel (Switzerland); Terraz, Sylvain [Hôpitaux Universitaires Genève (Switzerland); Artemisia, Simona; Meuli, Reto; Schmidt, Sabine [Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland)

    2013-02-15

    Purpose: To evaluate the diagnostic value of previously described MR features used for detecting suspected placental invasion according to observers’ experience. Materials and methods: Our population included 25 pregnant women (mean age 35.16) investigated by prenatal MRI (1.5 T, T1- and T2-weighted MR-sequences without i.v. contrast), among them 12 with histopathologically proven placental invasion and 13 women (52%) without placental invasion used as control group. Two senior and two junior radiologists blindly and independently reviewed MR-examinations in view of 6 previously defined MR-features indicating presence and degree of placental invasion (placenta increta, accreta or percreta). For each reader the sensibility, specificity, and receiver operating curve (ROC) were calculated. Interobserver agreements between senior and junior readers were determined. Stepwise logistic regression was performed including the 6 MR-features predictive of placental invasion. Results: Demographics between both groups were statistically equivalent. Overall sensitivity and specificity for placental invasion was 90.9% and 75.0% for seniors and 81.8% and 61.8% for juniors, respectively. The best single MR-feature indicating placental invasion was T2-hypointense placental bands (r{sup 2} = 0.28), followed by focally interrupted myometrial border, infiltration of pelvic organs and tenting of the bladder (r{sup 2} = 0.36). Interobserver agreement for detecting placental invasion was 0.64 for seniors and 0.41 for juniors, thus substantial and moderate, respectively. Seniors detected placental invasion and depth of infiltration with significantly higher diagnostic certitude than juniors (p = 0.0002 and p = 0.0282, respectively). Conclusion: MRI can be a reliable and reproducible tool for the detection of suspected placental invasion, but the diagnostic value significantly depends on observers’ experience.

  5. Mechanical and optical behavior of a tunable liquid lens using a variable cross section membrane: modeling results

    Science.gov (United States)

    Flores-Bustamante, Mario C.; Rosete-Aguilar, Martha; Calixto, Sergio

    2016-03-01

    A lens containing a liquid medium and having at least one elastic membrane as one of its components is known as an elastic membrane lens (EML). The elastic membrane may have a constant or variable thickness. The optical properties of the EML change by modifying the profile of its elastic membrane(s). The EML formed of elastic constant thickness membrane(s) have been studied extensively. However, EML information using elastic membrane of variable thickness is limited. In this work, we present simulation results of the mechanical and optical behavior of two EML with variable thickness membranes (convex-plane membranes). The profile of its surfaces were modified by liquid medium volume increases. The model of the convex-plane membranes, as well as the simulation of its mechanical behavior, were performed using Solidworks® software; and surface's points of the deformed elastic lens were obtained. Experimental stress-strain data, obtained from a silicone rubber simple tensile test, according to ASTM D638 norm, were used in the simulation. Algebraic expressions, (Schwarzschild formula, up to four deformation coefficients, in a cylindrical coordinate system (r, z)), of the meridional profiles of the first and second surfaces of the deformed convex-plane membranes, were obtained using the results from Solidworks® and a program in the software Mathematica®. The optical performance of the EML was obtained by simulation using the software OSLO® and the algebraic expressions obtained in Mathematica®.

  6. Randomised Response Technique-An Innovative Method To Measure Culturally Sensitive Variables : Results From A Pilot Study

    Directory of Open Access Journals (Sweden)

    Soudarssanane M. B

    2003-01-01

    Full Text Available Research questions: What is the advantage of Randomized Response Technique (RRT over the conventional Direct Interview (DI and Anonymous Questionnaire (AQ in the assessment of culturally sensitive variables? Objectives: To compare the efficacy of the three methods, namely RRT, DI and AQ in the measurement of prevalence of Pre/Extra marital sex. Study design: Cross sectional study, using the three methods. Setting: A pilot study in a given community in Pondicherry. Statistical analysis: Probability equations. Results: The prevalence of pre/extra marital sex in the study population by the DI, AQ and RRT methods were 0%, 6% and 10% respectively in this pilot study. Conclusion: RRT improves validity of measurement of culturally sensitive variables both by ensuring a high participation in the study and by enabling a true response by assuring full confidentiality of information.

  7. Significance of spatial variability in precipitation for process-oriented modelling: results from two nested catchments using radar and ground station data

    Directory of Open Access Journals (Sweden)

    D. Tetzlaff

    2005-01-01

    Full Text Available The importance of considering the spatial distribution of rainfall for process-oriented hydrological modelling is well-known. However, the application of rainfall radar data to provide such detailed spatial resolution is still under debate. In this study the process-oriented TACD (Tracer Aided Catchment model, Distributed model had been used to investigate the effects of different spatially distributed rainfall input on simulated discharge and runoff components on an event base. TACD is fully distributed (50x50m2 raster cells and was applied on an hourly base. As model input rainfall data from up to 7 ground stations and high resolution rainfall radar data from operational C-band radar were used. For seven rainfall events the discharge simulations were investigated in further detail for the mountainous Brugga catchment (40km2 and the St. Wilhelmer Talbach (15.2km2 sub-basin, which are located in the Southern Black Forest Mountains, south-west Germany. The significance of spatial variable precipitation data was clearly demonstrated. Dependent on event characteristics, localized rain cells were occasionally poorly captured even by a dense ground station network, and this resulted in inadequate model results. For such events, radar data can provide better input data. However, an extensive data adjustment using ground station data is required. For this purpose a method was developed that considers the temporal variability in rainfall intensity in high temporal resolution in combination with the total rainfall amount of both data sets. The use of the distributed catchment model allowed further insights into spatially variable impacts of different rainfall estimates. Impacts for discharge predictions are the largest in areas that are dominated by the production of fast runoff components. The improvements for distributed runoff simulation using high resolution rainfall radar input data are strongly dependent on the investigated scale, the event

  8. Using XMM-Newton to study the energy dependent variability of H 1743-322 during its 2014 outburst

    CERN Document Server

    Stiele, H

    2016-01-01

    Black hole transients during bright outbursts show distinct changes of their spectral and variability properties as they evolve during an outburst, that are interpreted as evidence for changes in the accretion flow and X-ray emitting regions. We obtained an anticipated XMM-Newton ToO observation of H 1743-322 during its outburst in September 2014. Based on data of eight outbursts observed in the last 10 years we expected to catch the start of the hard-to-soft state transition. The fact that neither the general shape of the observed power density spectrum nor the characteristic frequency show an energy dependence implies that the source still stays in the low-hard state at the time of our observation near outburst peak. The spectral properties agree with the source being in the low-hard state and a Swift/XRT monitoring of the outburst reveals that H 1743-322 stays in the low-hard state during the entire outburst (a. k. a. 'failed outburst'). We derive the averaged QPO waveform and obtain phase-resolved spectra...

  9. Epidemiology of behavioral dependence: literature review and results of original studies.

    Science.gov (United States)

    Lejoyeux, M; Mc Loughlin, M; Adès, J

    2000-03-01

    The extension of the definition of dependence leads to the consideration of some impulsive disorders as a form of dependence disorder. This pathological condition is characterized by the repetitive occurrence of impulsive and uncontrolled behaviors. Other clinical characteristics are failure to resist an impulse, drive or temptation to perform some act harmful to oneself and/or others, an increasing sense of tension or excitement before acting out, and a sense of pleasure, gratification or release at the time of the behavior or shortly thereafter. Behavioral dependences most often described are pathological gambling, kleptomania, trichotillomania and compulsive buying. Studies using a specific assessment scale, the South Oaks Gambling Screen, distinguished problem gambling from pathological gambling. Social gamblers spend 5% of their money and pathological gamblers 14 to 45%. Prevalence of 'problem gambling' is 4% and pathological gambling 2%. Several studies have suggested that the incidence of pathological gambling is eight to ten times greater in alcohol-dependent patients than in the general population. No systematic study has assessed the prevalence of kleptomania. Data come from case reports. Among subjects arrested after a theft, prevalence of kleptomania varied between 0 and 24%. Trichotillomania prevalence rate is 0.6% among students. Studies using less restrictive diagnostic criteria found a prevalence rate of 3.4% in women and 1.5% in men. The disorder is often unrecognized; 40% of the cases are not diagnosed and 58% of the patients have never been treated. Prevalence studies of compulsive buying found a rate between 1 and 6% in the general population. Compulsive buying is significantly more frequent among women (90% of the cases). Study of family history of compulsive buyers showed a high frequency of alcohol-dependence disorder (20%) and depression (18%). In all cases of behavioral dependence disorders, a high level of impulsivity and sensation

  10. Planck intermediate results. XXII. Frequency dependence of thermal emission from Galactic dust in intensity and polarization

    DEFF Research Database (Denmark)

    Cardoso, J. F.; Delabrouille, J.; Ganga, K.;

    2015-01-01

    Planck has mapped the intensity and polarization of the sky at microwave frequencies with unprecedented sensitivity. We use these data to characterize the frequency dependence of dust emission. We make use of the Planck 353 GHz I, Q, and U Stokes maps as dust templates, and cross-correlate them w...

  11. Planck intermediate results. XXII. Frequency dependence of thermal emission from Galactic dust in intensity and polarization

    DEFF Research Database (Denmark)

    Cardoso, J. F.; Delabrouille, J.; Ganga, K.

    2015-01-01

    Planck has mapped the intensity and polarization of the sky at microwave frequencies with unprecedented sensitivity. We use these data to characterize the frequency dependence of dust emission. We make use of the Planck 353 GHz I, Q, and U Stokes maps as dust templates, and cross-correlate them...

  12. How Does Cognitive Behaviour Therapy Work with Opioid-Dependent Clients? Results of the UKCBTMM Study

    Science.gov (United States)

    Kouimtsidis, Christos; Reynolds, Martina; Coulton, Simon; Drummond, Colin

    2012-01-01

    Introduction: Process research in psychotherapy is important to understand how treatment works. The National Institute of Clinical Excellence guidelines suggest that in methadone maintenance treatment (MMT) for opioid dependence, drug key-working should be based on cognitive behavioural therapy (CBT) principles. This article reports the findings…

  13. Impact of ENSO variability on the Pacific Equatorial Undercurrent (EUC) sources: A modeling approach depending on the horizontal resolution

    Science.gov (United States)

    Babonneix, A.; Gourdeau, L.; Durand, F.; Menkes, C. E.; Djath, N.

    2012-04-01

    As the most powerful source of climatic variability in the Pacific Ocean, the El Niño Southern Oscillation (ENSO) deeply impacts the equatorial oceanic currents. The Pacific Equatorial UnderCurrent (EUC) is a powerful jet flowing eastward and shoaling with the thermocline in the eastern Pacific, bringing cold waters in surface that retroact with the atmosphere. Its transport has thus been found to follow significant variations at ENSO timescale, with an increased (decreased) transport in La Niña (El Niño) phases. However, the EUC mean properties also vary more slowly due to extratropical forcing. This process is able to modify the heat and mass transports of the subducted waters that feed the EUC. By changing the mean equatorial oceanic conditions, this is suspected to modulate in return the ENSO signal. The EUC sources have very different origins: contributions come from both hemispheres, in part from the Low-Latitude Western Boundary Currents (LLWBCs) and the remaining from the interior ocean. Each source follows different pathways and is characterized by particular properties which differently influences the properties of the downstream equatorial undercurrent and the cold tongue upwelling. The question of the location of the different EUC sources is thus of crucial importance. In this poster, we investigate the links between the ENSO variability and the partitioning of the EUC sources. For this purpose, we use a set of five simulations made available by the DRAKKAR project ranging from a 2° laminar resolution to a turbulent 1/12° partly resolving the meso-scale processes. Increasing models horizontal resolution is largely thought to improve the quality of the resulting simulated currents, in terms of dynamics as of variability. Results show that if some distinct elements appear in terms of mean transit times, little variations are found in terms of partitioning within the different simulations. However, we show that the partitioning between the EUC sources

  14. An inventory model of two-warehouse system with variable demand dependent on instantaneous displayed stock and marketing decisions via hybrid RCGA

    Directory of Open Access Journals (Sweden)

    A. K. Bhunia

    2011-04-01

    Full Text Available In this paper, a single item deterministic inventory model with two separate warehouses called owned warehouse/show-room (OW and rented warehouse (RW is developed. The proposed model of this paper also considers a realistic assumption regarding the storage capacity of the rented warehouse. Demand is a function of selling price, advertisement of an item and displayed inventory level in OW. The stocks of RW are shipped to OW under bulk release pattern where shortages are not allowed. We discuss different scenarios of the proposed model to address relative size of stock dependency parameters and the capacity of owned warehouse. For each scenario, the corresponding problem is formulated as a constrained mixed integer nonlinear programming problem with three integer and two non-integer variables and a real coded genetic algorithm (RCGA is developed to solve the resulted problem. The proposed model of the paper is also examined using some numerical examples and sensitivity analysis is performed.

  15. A uniqueness result for the identification of a time-dependent diffusion coefficient

    Science.gov (United States)

    Fraguela, A.; Infante, J. A.; Ramos, A. M.; Rey, J. M.

    2013-12-01

    This paper deals with the problem of determining the time-dependent thermal diffusivity coefficient of a medium, when the evolution of the temperature in a part of it is known. Such situations arise in the context of food technology, when thermal processes at high pressures are used for extending the shelf life of the food, in order to preserve its nutritional and organoleptic properties (Infante et al 2009 On the Modelling and Simulation of High Pressure Processes and Inactivation of Enzymes in Food Engineering pp 2203-29 and Otero et al 2007 J. Food Eng. 78 1463-70). The phenomenon is modeled by the heat equation involving a term which depends on the source temperature and pressure increase, and appropriate initial and boundary conditions. We study the inverse problem of determining time-dependent thermal diffusivities k, when some temperature measurements at the border and inside the medium are known. We prove the uniqueness of the inverse problem solution under suitable a priori assumptions on regularity, size and growth of k.

  16. Time-Dependent Photoionization in a Dusty Medium I Code Description and General Results

    CERN Document Server

    Perna, R; Perna, Rosalba; Lazzati, Davide

    2002-01-01

    We present a time-dependent photoionization code that combines self-consistently metal evolution and dust destruction under an intense X-ray UV radiation field. Firstly, we extend the mathematical formulation of the time-dependent evolution of dust grains under an intense radiation flux with the inclusion of the process of ion field emission (IFE). We determine the relative importance of IFE with respect to X-ray and UV sublimation as a function of grain size, intensity and hardness of the incident spectrum. We then combine the processes of dust destruction with a photoionization code that follows the evolution of the ionization states of the metals and the relative radiative transitions. Our code treats, self-consistently, the gradual recycling of metals into gas as dust is sublimated away; it allows for any initial dust grain distribution and follows its evolution in space and time. In this first paper, we use our code to study the time-dependent behaviour of the X-ray and optical opacities in the nearby en...

  17. Chronic low-grade peripheral inflammation is associated with severe nicotine dependence in schizophrenia: results from the national multicentric FACE-SZ cohort.

    Science.gov (United States)

    Fond, G; Berna, F; Andrianarisoa, M; Godin, O; Leboyer, M; Brunel, L; Aouizerate, B; Capdevielle, D; Chereau, I; D'Amato, T; Denizot, H; Dubertret, C; Dubreucq, J; Faget, C; Gabayet, F; Llorca, P M; Mallet, J; Misdrahi, D; Passerieux, C; Richieri, R; Rey, R; Schandrin, A; Urbach, M; Vidailhet, P; Boyer, L; Schürhoff, F

    2017-02-25

    Chronic peripheral inflammation (CPI) has been associated with cognitive impairment in schizophrenia (SZ). However, its sources remain unclear, more specifically it is not known whether tobacco smoking is a source of inflammation or not in SZ subjects. Moreover, nicotine (NIC), the major psychoactive compound of tobacco, shows strong anti-inflammatory properties in vitro, as well as inducing a severe biological dependence when administered repeatedly. The objective of the present study was to determine if CPI was associated with tobacco smoking and/or NIC dependence in schizophrenia. Three hundred and forty five stabilized community-dwelling SZ subjects aged 16 years or older (mean age = 32 years, 73% male) were consecutively included in the network of the FondaMental Expert Centers for Schizophrenia and assessed with validated scales. CPI was defined by a highly sensitive C-reactive protein (hsCRP) ≥3 mg/L. Current tobacco status was self-declared. Severe NIC dependence was defined by a Fagerstrom Test for Nicotine Dependence score ≥7. Overall, 159 (46.1%) were non-smokers, 117 (33.9%) and 69 (20%) were current tobacco smokers with, respectively, low and severe nicotine dependence. In a multivariate model, CPI remained associated with severe NIC dependence (29 vs 15%, OR = 2.8, p = 0.003) and body mass index (OR = 1.1, p dependence, number of daily smoked cigarettes, cannabis use, alcohol use or illness characteristics was found (all p > 0.05). CPI was associated with severe NIC dependence but not with tobacco smoking with low to moderate NIC dependence in SZ, independently of socio-demographic variables, body mass index, alcohol consumption and antidepressant intake. This result highlights the potential CPI consequences of the high prevalence of heavy tobacco smoking in SZ, indicating the importance of new therapeutic strategies for tobacco cessation in SZ.

  18. Influence of hypoxia and hypercapnia on sleep state-dependent heart rate variability behavior in newborn lambs.

    Science.gov (United States)

    Beuchée, Alain; Hernández, Alfredo I; Duvareille, Charles; Daniel, David; Samson, Nathalie; Pladys, Patrick; Praud, Jean-Paul

    2012-11-01

    Although hypercapnia and/or hypoxia are frequently present during chronic lung disease of infancy and have also been implicated in sudden infant death syndrome (SIDS), their effect on cardiac autonomic regulation remains unclear. The authors' goal is to test that hypercapnia and hypoxia alter sleep-wake cycle-dependent heart rate variability (HRV) in the neonatal period. Experimental study measuring HRV during sleep states in lambs randomly exposed to hypercapnia, hypoxia, or air. University center for perinatal research in ovines (Sherbrooke, Canada). INSERM-university research unit for signal processing (Rennes, France). Six nonsedated, full-term lambs. Each lamb underwent polysomnographic recordings while in a chamber flowed with either air or 21% O(2) + 5% CO(2) (hypercapnia) or 10% O(2) + 0% CO(2) (hypoxia) on day 3, 4, and 5 of postnatal age. Hypercapnia increased the time spent in wakefulness and hypoxia the time spent in quiet sleep (QS). The state of alertness was the major determinant of HRV characterized with linear or nonlinear methods. Compared with QS, active sleep (AS) was associated with an overall increase in HRV magnitude and short-term self-similarity and a decrease in entropy of cardiac cycle length in air. This AS-related HRV pattern persisted in hypercapnia and was even more pronounced in hypoxia. Enhancement of AS-related sympathovagal coactivation in hypoxia, together with increased heart rate regularity, may be evidence that AS + hypoxia represent a particularly vulnerable state in early life. This should be kept in mind when deciding the optimal arterial oxygenation target in newborns and when investigating the potential involvement of hypoxia in SIDS pathogenesis.

  19. Doping-dependent magnetization plateaus of a coupled spin-electron chain: exact results

    Science.gov (United States)

    Strečka, Jozef; Čisárová, Jana

    2016-10-01

    A coupled spin-electron chain composed of localized Ising spins and mobile electrons is exactly solved in an external magnetic field within the transfer-matrix method. The ground-state phase diagram involves in total seven different ground states, which differ in the number of mobile electrons per unit cell and the respective spin arrangements. A rigorous analysis of the low-temperature magnetization process reveals doping-dependent magnetization plateaus, which may be tuned through the density of mobile electrons. It is demonstrated that the fractional value of the electron density is responsible for an enhanced magnetocaloric effect due to an annealed bond disorder of the mobile electrons.

  20. Method-dependent variability in determination of prevalence of Campylobacter jejuni and Campylobacter coli in Canadian retail poultry.

    Science.gov (United States)

    Carrillo, Catherine D; Plante, Daniel; Iugovaz, Irène; Kenwell, Robyn; Bélanger, Ghislaine; Boucher, Francine; Poulin, Nathalie; Trottier, Yvon-Louis

    2014-10-01

    Campylobacter is the most frequent cause of bacterial gastroenteritis in Canada, and the illness is commonly associated with poultry consumption. Whereas Canadian retail poultry is often contaminated with campylobacters, studies on the prevalence of this organism are inconsistent due to variability in sampling and microbiological methodology. To determine the current microbiological status of Canadian poultry, and to evaluate two commonly used microbiological methods, 348 raw poultry samples were collected at retail across Canada over a period of 3 years (2007 to 2010) and were analyzed for the presence of thermophilic Campylobacter species. The overall prevalence of Campylobacter spp. was found to be 42.8% by a combination of the two testing methods, with 33.9% of the samples positive for C. jejuni, 3.7% of the samples positive for C. coli, and 5.2% of the samples positive for both. Variability in Campylobacter spp. prevalence was observed in samples obtained from different regions across Canada and from poultry with or without skin, but this was not statistically significant. In co-contaminated samples, C. jejuni was preferentially recovered from Preston agar compared with mCCDA and Campy-Cefex agar, with an increase in recovery of C. coli on all selective media after 48 h of enrichment. A subset of 214 of the poultry rinses were analyzed by both Health Canada's standard method, MFLP-46 (enrichment in Park and Sanders broth), and a second method requiring enrichment in Bolton broth. Significantly more positive samples were obtained with the MFLP-46 method (40.6%) than with the alternate method (35.0%). This improved recovery with MFLP-46 may be due to the omission of cycloheximide from this method. These results demonstrate that determination of prevalence of Campylobacter spp. on poultry products may be significantly impacted by the choice of microbiological methods used. Canadian poultry continues to be a source of exposure to Campylobacter spp.

  1. Tidal Marsh Outwelling of Dissolved Organic Matter and Resulting Temporal Variability in Coastal Water Optical and Biogeochemical Properties

    Science.gov (United States)

    Tzortziou, Maria; Neale, Patrick J.; Megonigal, J. Patrick; Butterworth, Megan; Jaffe, Rudolf; Yamashita, Youhei

    2010-01-01

    Coastal wetlands are highly dynamic environments at the land-ocean interface where human activities, short-term physical forcings and intense episodic events result in high biological and chemical variability. Long being recognized as among the most productive ecosystems in the world, tidally-influenced coastal marshes are hot spots of biogeochemical transformation and exchange. High temporal resolution observations that we performed in several marsh-estuarine systems of the Chesapeake Bay revealed significant variability in water optical and biogeochemical characteristics at hourly time scales, associated with tidally-driven hydrology. Water in the tidal creek draining each marsh was sampled every hour during several semi-diurnal tidal cycles using ISCO automated samplers. Measurements showed that water leaving the marsh during ebbing tide was consistently enriched in dissolved organic carbon (DOC), frequently by more than a factor of two, compared to water entering the marsh during flooding tide. Estimates of DOC fluxes showed a net DOC export from the marsh to the estuary during seasons of both low and high biomass of marsh vegetation. Chlorophyll amounts were typically lower in the water draining the marsh, compared to that entering the marsh during flooding tide, suggesting that marshes act as transformers of particulate to dissolved organic matter. Moreover, detailed optical and compositional analyses demonstrated that marshes are important sources of optically and chemically distinctive, relatively complex, high molecular weight, aromatic-rich and highly colored dissolved organic compounds. Compared to adjacent estuarine waters, marsh-exported colored dissolved organic matter (CDOM) was characterized by considerably stronger absorption (more than a factor of three in some cases), larger DOC-specific absorption, lower exponential spectral slope, larger fluorescence signal, lower fluorescence per unit absorbance, and higher fluorescence at visible wavelengths

  2. Threshold-dependent variability of coronary artery calcification measurements - implications for contrast-enhanced multi-detector row-computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Moselewski, Fabian [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Ferencik, Maros [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Achenbach, Stephan [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Department of Internal Medicine II (Cardiology), University of Erlangen (Germany); Abbara, Suhny [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Cury, Ricardo C. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Booth, Sarah L. [Jean Mayer USDA Human Nutrition Research Center on Aging, 711 Washington St., Boston, MA 02114 (United States); Jang, Ik-Kyung [Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Brady, Thomas J. [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States)]. E-mail: uhoffman@partners.org

    2006-03-15

    Introduction: The present study investigated the threshold-dependent variability of coronary artery calcification (CAC) measurements and the potential to quantify CAC in contrast-enhanced multi-detector row-computed tomography (MDCT). Methods: We compared the mean CT attenuation of CAC to luminal contrast enhancement of the coronary arteries in 30 patients (n = 30) undergoing standard coronary contrast-enhanced spiral MDCT. The modified Agatston score [AS], calcified plaque volume [CV], and mineral mass [MM] at four different thresholds (130, 200, 300, and 400 HU) were measured in 50 patients who underwent non-contrast-enhanced MDCT. Results: Mean CT attenuation of CAC was similar to the attenuation of the contrast-enhanced coronary lumen (CAC 297.1 {+-} 68.7 HU versus 295 {+-} 65 HU (p < 0.0001), respectively). Above a threshold of 300 HU CAC measurements significantly varied to standard measurements obtained at a threshold of 130 HU (p < 0.0001). The threshold-dependent variation of MM measurements was significantly smaller than for AS and CV (130 HU versus 400 HU: 63, 75, and 81, respectively; p < 0.001). These differences resulted in a change of age and gender based percentile category for AS in 78% of subjects. Discussion: We demonstrated that CAC measurements are threshold dependent with MM measurements having significantly less variation than AS or CV. Due to the similarity of mean CT attenuation of CAC and the contrast-enhanced coronary lumen accurate quantification of CAC may be difficult in standard coronary contrast-enhanced spiral MDCT.

  3. Modelling diameter distribution of Tetraclinis articulata in Tunisia using normal and Weibull distributions with parameters depending on stand variables

    Directory of Open Access Journals (Sweden)

    Sghaier T

    2016-10-01

    Full Text Available The objective of this study was to evaluate the effectiveness of both Normal and two-parameter Weibull distributions in describing diameter distribution of Tetraclinis articulata stands in north-east Tunisia. The parameters of the Weibull function were estimated using the moments method and maximum likelihood approaches. The data used in this study came from temporary plots. The three diameter distribution models were compared firstly by estimating the parameters of the distribution directly from individual tree measurements taken in each plot (parameter estimation method, and secondly by predicting the same parameters from stand variables (parameter prediction method. The comparison was based on bias, mean absolute error, mean square error and the Reynolds’ index error (as a percentage. On the basis of the parameter estimation method, the Normal distribution gave slightly better results, whereas the Weibull distribution with the maximum likelihood approach gave the best results for the parameter prediction method. Hence, in the latter case, the Weibull distribution with the maximum likelihood approach appears to be the most suitable to estimate the parameters for reducing the different comparison criteria for the distribution of trees by diameter class in Tetraclinis articulata forests in Tunisia.

  4. New results in gravity dependent two-phase flow regime mapping

    Science.gov (United States)

    Kurwitz, Cable; Best, Frederick

    2002-01-01

    Accurate prediction of thermal-hydraulic parameters, such as the spatial gas/liquid orientation or flow regime, is required for implementation of two-phase systems. Although many flow regime transition models exist, accurate determination of both annular and slug regime boundaries is not well defined especially at lower flow rates. Furthermore, models typically indicate the regime as a sharp transition where data may indicate a transition space. Texas A&M has flown in excess of 35 flights aboard the NASA KC-135 aircraft with a unique two-phase package. These flights have produced a significant database of gravity dependent two-phase data including visual observations for flow regime identification. Two-phase flow tests conducted during recent zero-g flights have added to the flow regime database and are shown in this paper with comparisons to selected transition models. .

  5. General Existence Results for Third-Order Nonconvex State-Dependent Sweeping Process with Unbounded Perturbations

    Directory of Open Access Journals (Sweden)

    M. Bounkhel

    2012-01-01

    Full Text Available We prove the existence of solutions for third-order nonconvex state-dependent sweeping process with unbounded perturbations of the form: -A(x(3(t∈N(K(t,ẋ(t;  A(ẍ(t+F(t,x(t,ẋ(t,ẍ(t+G(x(t,ẋ(t,ẍ(t      a.e.  [0,T], A(ẍ(t∈K(t,ẋ(t, a.e.    t∈[0,T], x(0=x0,ẋ(0=u0, ẍ(0=υ0, where T>0, K is a nonconvex Lipschitz set-valued mapping, F is an unbounded scalarly upper semicontinuous convex set-valued mapping, and G is an unbounded uniformly continuous nonconvex set-valued mapping in a separable Hilbert space H.

  6. On recoil energy dependent void swelling in pure copper: part 1, experimental results

    DEFF Research Database (Denmark)

    Singh, B.N.; Eldrup, M.; Horsewell, Andy

    2000-01-01

    , the void swelling should sensitively depend on the recoil energy since it affects strongly the intracascade clustering of SIAs and vacancies, particularly at lower recoil energies. In order to test the validity of this prediction directly by experiments, pure and annealed copper specimens were irradiated...... with 2.5 MeV electrons, 3 MeV protons and fission neutrons at about 520K. All three sets of irradiation experiments were carried out with a similar damage rate (of the order of 10-8 NRT dpa/s). Post-irradiation defect microstructures were investigated using electrical resistivity, transmission electron...... microscopy (TEM) and positron annihilation spectroscopy (PAS). The accumulation of defects in the form of planar clusters as well as voids is found to increase substantially with increasing recoil energy. This is in good accord with the predictions of the PBM....

  7. Dependence of {delta}E effect on internal stresses in nickel: Experimental results by laser interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Chicharro, J.M. [Dept. de Mecanica Aplicada e Ingenieria de Proyectos, E.T.S.I. Industriales, Universidad de Castilla-La Mancha, Avd. Camilo Jose Cela s/n, 13071 Ciudad Real (Spain)]. E-mail: josemanuel.chicharro@uclm.es; Bayon, A. [Dept. de Fisica Aplicada a los Recursos Naturales, E.T.S.I. Minas, Universidad Politecnica de Madrid, c/Rios Rosas, 21, 28003 Madrid (Spain); Salazar, F. [Dept. de Fisica Aplicada a los Recursos Naturales, E.T.S.I. Minas, Universidad Politecnica de Madrid, c/Rios Rosas, 21, 28003 Madrid (Spain)

    2006-02-15

    The speckle heterodyne interferometry is applied to the study of the dependence of Young's modulus on both the magnetic field and the internal stresses in a soft ferromagnetic material. Young's modulus is determined from the first natural longitudinal frequency of a slender magnetic rod positioned within a solenoid. Vibration of the sample is detected by an optical heterodyne system with a wide bandwidth. The samples are heated to above the Curie point and then cooled at several rates in order to induce different internal stresses. The study refers to nickel rods 10mm in diameter and 110mm in length. The grain sizes of the samples are also determined and related to changes in {delta}E.

  8. During yeast chronological aging resveratrol supplementation results in a short-lived phenotype Sir2-dependent.

    Science.gov (United States)

    Orlandi, Ivan; Stamerra, Giulia; Strippoli, Maurizio; Vai, Marina

    2017-08-01

    Resveratrol (RSV) is a naturally occurring polyphenolic compound endowed with interesting biological properties/functions amongst which are its activity as an antioxidant and as Sirtuin activating compound towards SIRT1 in mammals. Sirtuins comprise a family of NAD(+)-dependent protein deacetylases that are involved in many physiological and pathological processes including aging and age-related diseases. These enzymes are conserved across species and SIRT1 is the closest mammalian orthologue of Sir2 of Saccharomyces cerevisiae. In the field of aging researches, it is well known that Sir2 is a positive regulator of replicative lifespan and, in this context, the RSV effects have been already examined. Here, we analyzed RSV effects during chronological aging, in which Sir2 acts as a negative regulator of chronological lifespan (CLS). Chronological aging refers to quiescent cells in stationary phase; these cells display a survival-based metabolism characterized by an increase in oxidative stress. We found that RSV supplementation at the onset of chronological aging, namely at the diauxic shift, increases oxidative stress and significantly reduces CLS. CLS reduction is dependent on Sir2 presence both in expired medium and in extreme Calorie Restriction. In addition, all data point to an enhancement of Sir2 activity, in particular Sir2-mediated deacetylation of the key gluconeogenic enzyme phosphoenolpyruvate carboxykinase (Pck1). This leads to a reduction in the amount of the acetylated active form of Pck1, whose enzymatic activity is essential for gluconeogenesis and CLS extension. Copyright © 2017. Published by Elsevier B.V.

  9. An Analysis of Some Variables Affecting the Internet Dependency Level of Turkish Adolescents by Using Decision Tree Methods

    Science.gov (United States)

    Kayri, Murat; Gunuc, Selim

    2010-01-01

    Internet dependency is going to expand into social life in wide area whereas it has been accepted as a pathological and psychological disease. Knowing the basic effects of internet dependency is an inevitable approach to use the internet technology healthy. In this study, internet dependency levels of 754 students were examined with the Internet…

  10. Can weighting compensate for nonresponse bias in a dependent variable? An evaluation of weighting methods to correct for substantive bias in a mail survey among Dutch municipalities

    NARCIS (Netherlands)

    van Goor, H; Stuiver, B

    1998-01-01

    Due to a lack of pertinent data, little is known about nonresponse in substantive, generally "dependent" variables and its consequences. However, in a study on policy performance of Dutch municipalities, we were fortunately able to gather performance data fur respondents and nonrespondents from

  11. Convergence Analysis of Semi-Implicit Euler Methods for Solving Stochastic Age-Dependent Capital System with Variable Delays and Random Jump Magnitudes

    Directory of Open Access Journals (Sweden)

    Qinghui Du

    2014-01-01

    Full Text Available We consider semi-implicit Euler methods for stochastic age-dependent capital system with variable delays and random jump magnitudes, and investigate the convergence of the numerical approximation. It is proved that the numerical approximate solutions converge to the analytical solutions in the mean-square sense under given conditions.

  12. Unexpected variability of millennium green: structural color of Japanese jewel beetle resulted from thermosensitive porous organic multilayer.

    Science.gov (United States)

    Adachi, Eiki

    2007-09-01

    The Japanese jewel beetle (Chrysochroa fulgidissima) is one of the beautiful beetles showing metallic green color that is kept over a millennium. This is a typical structural color resulting from a multilayer, frequently seen in insects. It was found that the elytra unexpectedly change the color from original green to blue or red by heating at 200 degrees C or by immersing in bromoform for over 1 month. This variability implies that the multilayer consists of a thermosensitive porous material. The color change induced by heating was accompanied with elytron shrinkage; the sensitivity of the reflection peak was -0.6 nm/ degrees C in 30-65 degrees C. The porous structure was determined by positron annihilation lifetime spectroscopy; the averaged pore radius was around 0.25-0.30 nm, which is close to the size of the bromoform molecule. These features prove the thermosensitivity and porous structure of the multilayer although in unusual environments.

  13. Time-dependent hydrogen ionisation in the solar chromosphere. I: Methods and first results

    CERN Document Server

    Wedemeyer-Boehm, J L S

    2006-01-01

    An approximate method for solving the rate equations for the hydrogen populations was extended and implemented in the three-dimensional radiation (magneto-)hydrodynamics code CO5BOLD. The method is based on a model atom with six energy levels and fixed radiative rates. It has been tested extensively in one-dimensional simulations. The extended method has been used to create a three-dimensional model that extends from the upper convection zone to the chromosphere. The ionisation degree of hydrogen in our time-dependent simulation is comparable to the corresponding equilibrium value up to 500 km above optical depth unity. Above this height, the non-equilibrium ionisation degree is fairly constant over time and space, and tends to be at a value set by hot propagating shock waves. The hydrogen level populations and electron density are much more constant than the corresponding values for statistical equilibrium, too. In contrast, the equilibrium ionisation degree varies by more than 20 orders of magnitude between...

  14. Power Smoothing of a Variable-Speed Wind Turbine Generator in Association With the Rotor-Speed-Dependent Gain

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeonhee; Kang, Moses; Muljadi, Eduard; Park, Jung-Wook; Kang, Yong Cheol

    2017-07-01

    This paper proposes a power-smoothing scheme for a variable-speed wind turbine generator (WTG) that can smooth out the WTG's fluctuating power caused by varying wind speeds, and thereby keep the system frequency within a narrow range. The proposed scheme employs an additional loop based on the system frequency deviation that operates in conjunction with the maximum power point tracking (MPPT) control loop. Unlike the conventional, fixed-gain scheme, its control gain is modified with the rotor speed. In the proposed scheme, the control gain is determined by considering the ratio of the output of the additional loop to that of the MPPT loop. To improve the contribution of the scheme toward maintaining the frequency while ensuring the stable operation of WTGs, in the low rotor speed region, the ratio is set to be proportional to the rotor speed; in the high rotor speed region, the ratio remains constant. The performance of the proposed scheme is investigated under varying wind conditions for the IEEE 14-bus system. The simulation results demonstrate that the scheme successfully operates regardless of the output power fluctuation of a WTG by adjusting the gain with the rotor speed, and thereby improves the frequency-regulating capability of a WTG.

  15. Reader- and instrument-dependent variability in the electrocardiographic assessment of arrhythmogenic right ventricular dysplasia/cardiomyopathy.

    Science.gov (United States)

    Jain, Rahul; Tandri, Harikrishna; Daly, Amy; Tichnell, Crystal; James, Cynthia; Abraham, Theodore; Judge, Daniel P; Calkins, Hugh; Dalal, Darshan

    2011-05-01

    Despite the use of standardized definitions, widely varying prevalence estimates of electrocardiographic (ECG) features related to arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) have been reported in different cohorts. This study was aimed at examining the variability in the ECG interpretation resulting from the same reader, different readers, and using different ECG-resolutions. Blinded to other clinical data, 2 readers examined quantitative and qualitative ECG features of 20 (10 ARVD/C) randomly selected individuals. ECGs were recorded at standard-speed (SS) and double-speed-double-amplitude (DS) settings. The SS ECGs were scanned, magnified 4×, and evaluated using electronic calipers (EL). One reader repeated all measurements. For both readers, the intraclass correlation coefficient (ICC) for the measurement of QRS duration was good between conventional and electronic evaluation [DS vs EL: Reader 1--0.64 (0.52-0.73); Reader 2--0.67 (0.55-0.76)][SS vs EL: Reader 1--0.60 (0.47-0.70); Reader 2--0.60 (0.47-0.70)]. Using the same resolution, the intrareader ICC was good for SS [0.70 (0.59-0.78)], DS [0.85 (0.80-0.90)], and EL [0.70 (0.69-0.83)] resolutions, but deteriorated for interreader comparisons [0.50 (0.36-0.62), 0.75 (0.66-0.82), and 0.75 (0.66-0.82), respectively]. For qualitative parameters, the intra- and interreader agreement was inconsistent for all but 2 parameters. Both readers were in perfect agreement while interpreting right precordial T-wave inversion [κ= 1] and right bundle branch block morphology (RBBB) [κ= 0.83 (0.5-1.0)] even when using SS resolution. Right precordial t-wave inversion and RBBB are the only ECG parameters that can be detected consistently even using the conventionally used ECG-resolution. The substantial variability in evaluation of other parameters is not improved even with the use of higher resolutions. © 2010 Wiley Periodicals, Inc.

  16. Density dependence and climate effects in Rocky Mountain elk: an application of regression with instrumental variables for population time series with sampling error.

    Science.gov (United States)

    Creel, Scott; Creel, Michael

    2009-11-01

    1. Sampling error in annual estimates of population size creates two widely recognized problems for the analysis of population growth. First, if sampling error is mistakenly treated as process error, one obtains inflated estimates of the variation in true population trajectories (Staples, Taper & Dennis 2004). Second, treating sampling error as process error is thought to overestimate the importance of density dependence in population growth (Viljugrein et al. 2005; Dennis et al. 2006). 2. In ecology, state-space models are used to account for sampling error when estimating the effects of density and other variables on population growth (Staples et al. 2004; Dennis et al. 2006). In econometrics, regression with instrumental variables is a well-established method that addresses the problem of correlation between regressors and the error term, but requires fewer assumptions than state-space models (Davidson & MacKinnon 1993; Cameron & Trivedi 2005). 3. We used instrumental variables to account for sampling error and fit a generalized linear model to 472 annual observations of population size for 35 Elk Management Units in Montana, from 1928 to 2004. We compared this model with state-space models fit with the likelihood function of Dennis et al. (2006). We discuss the general advantages and disadvantages of each method. Briefly, regression with instrumental variables is valid with fewer distributional assumptions, but state-space models are more efficient when their distributional assumptions are met. 4. Both methods found that population growth was negatively related to population density and winter snow accumulation. Summer rainfall and wolf (Canis lupus) presence had much weaker effects on elk (Cervus elaphus) dynamics [though limitation by wolves is strong in some elk populations with well-established wolf populations (Creel et al. 2007; Creel & Christianson 2008)]. 5. Coupled with predictions for Montana from global and regional climate models, our results

  17. Variability of low-density lipoprotein cholesterol response with different doses of atorvastatin, rosuvastatin, and simvastatin: results from VOYAGER.

    Science.gov (United States)

    Karlson, Björn W; Wiklund, Olov; Palmer, Michael K; Nicholls, Stephen J; Lundman, Pia; Barter, Philip J

    2016-10-01

    Patient response to statin treatment is individual and varied. As a consequence, when using a specific-dose approach, as recommended in the 2013 American College of Cardiology/American Heart Association guideline, there will be a range of reductions in the concentration of low-density lipoprotein cholesterol (LDL-C). The aim of this study was to use individual patient data from the VOYAGER meta-analysis to determine the extent of the variability in LDL-C reduction in response to treatment across the recommended doses of different statins. The percentage change from baseline in LDL-C was calculated using individual subject data collected from 32 258 patients treated with atorvastatin 10-80 mg, rosuvastatin 5-40 mg, or simvastatin 10-80 mg. The percentage change in LDL-C for each patient was then used to generate waterfall plots that demonstrated the extent of the variability in response to treatment at all doses of the three statins. The standard deviation of LDL-C reduction for all statins and doses ranged from 12.8 to 17.9%. The percentage of patients experiencing a suboptimal response (<30% reduction in LDL-C) ranged from 5.3 to 53.3%. These results indicate that there is considerable individual variation in the LDL-C reduction at all doses of simvastatin, atorvastatin, and rosuvastatin. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  18. Flows of Carreau fluid with pressure dependent viscosity in a variable porous medium: Application of polymer melt

    Directory of Open Access Journals (Sweden)

    M.Y. Malik

    2014-06-01

    Full Text Available The present work concerns the pressure dependent viscosity in Carreau fluid through porous medium. Four different combinations of pressure dependent viscosity and pressure dependent porous medium parameters are considered for two types of flow situations namely (i Poiseuille flow and (ii Couette flow. The solutions of non-linear equations have been evaluated numerically by Shooting method along with Runge-Kutta Fehlberg method. The physical features of pertinent parameters have been discussed through graphs.

  19. Using a latent variable approach to inform gender and racial/ethnic differences in cocaine dependence: a National Drug Abuse Treatment Clinical Trials Network study.

    Science.gov (United States)

    Wu, Li-Tzy; Pan, Jeng-Jong; Blazer, Dan G; Tai, Betty; Stitzer, Maxine L; Woody, George E

    2010-06-01

    This study applies a latent variable approach to examine gender and racial/ethnic differences in cocaine dependence, to determine the presence of differential item functioning (DIF) or item-response bias to diagnostic questions of cocaine dependence, and to explore the effects of DIF on the predictor analysis of cocaine dependence. The analysis sample included 682 cocaine users enrolled in two national multisite studies of the National Drug Abuse Treatment Clinical Trials Network (CTN). Participants were recruited from 14 community-based substance abuse treatment programs associated with the CTN, including 6 methadone and 8 outpatient nonmethadone programs. Factor and multiple indicators-multiple causes (MIMIC) procedures evaluated the latent continuum of cocaine dependence and its correlates. MIMIC analysis showed that men exhibited lower odds of cocaine dependence than women (regression coefficient, beta = -0.34), controlling for the effects of DIF, years of cocaine use, addiction treatment history, comorbid drug dependence diagnoses, and treatment setting. There were no racial/ethnic differences in cocaine dependence; however, DIF by race/ethnicity was noted. Within the context of multiple community-based addiction treatment settings, women were more likely than men to exhibit cocaine dependence. Addiction treatment research needs to further evaluate gender-related differences in drug dependence in treatment entry and to investigate how these differences may affect study participation, retention, and treatment response to better serve this population.

  20. Results of Current Density Distribution Mapping in PEM Fuel Cells Dependent on Operation Parameters

    Directory of Open Access Journals (Sweden)

    Zbigniew A. Styczynski

    2013-07-01

    Full Text Available This paper presents in situ measurements of a newly developed current density measurement system for proton exchange membrane fuel cells (PEMFC. While the functional principle and technical evaluation of the measurement system were presented in a previous paper, this paper analyzes the influence of various operation parameters, including multiple start-stop operation, at the anode, cathode and cooling locations on the distribution and long-term development of the current density. The system was operated for 500 h over two years with long periods of inactivity between measurements. The measurement results are evaluated and provide additional information on how to optimize the operation modes of fuel cells, including the start and stop of such systems as well as the water balance.

  1. Using 'payment by results' to fund the treatment of dependent drug users--proceed with care!

    Science.gov (United States)

    Maynard, Alan; Street, Andrew; Hunter, Rachael

    2011-10-01

    The UK government is changing its system of payment for drug treatment services in order to reward the achievement of better patient outcomes. This is a model that may be taken up internationally. This 'payment by results' funding system will reward providers for achieving good outcomes in terms of whether clients are drug free, employed and/or not convicted of a criminal offence. Providers will also receive a payment based on health and wellbeing outcome measurement. The definition and measurement of success in achieving these outcomes is complex and challenging, as is the need to bridge treatment costs during the period in which outcomes are pursued. This experiment requires careful evaluation if the delivery of drug treatment is not to be jeopardized or fragmented.

  2. How stand productivity results from size- and competition-dependent growth and mortality.

    Directory of Open Access Journals (Sweden)

    John P Caspersen

    Full Text Available BACKGROUND: A better understanding of the relationship between stand structure and productivity is required for the development of: a scalable models that can accurately predict growth and yield dynamics for the world's forests; and b stand management regimes that maximize wood and/or timber yield, while maintaining structural and species diversity. METHODS: We develop a cohort-based canopy competition model ("CAIN", parameterized with inventory data from Ontario, Canada, to examine the relationship between stand structure and productivity. Tree growth, mortality and recruitment are quantified as functions of diameter and asymmetric competition, using a competition index (CAI(h defined as the total projected area of tree crowns at a given tree's mid-crown height. Stand growth, mortality, and yield are simulated for inventoried stands, and also for hypothetical stands differing in total volume and tree size distribution. RESULTS: For a given diameter, tree growth decreases as CAI(h increases, whereas the probability of mortality increases. For a given CAI(h, diameter growth exhibits a humped pattern with respect to diameter, whereas mortality exhibits a U-shaped pattern reflecting senescence of large trees. For a fixed size distribution, stand growth increases asymptotically with total density, whereas mortality increases monotonically. Thus, net productivity peaks at an intermediate volume of 100-150 m(3/ha, and approaches zero at 250 m(3/ha. However, for a fixed stand volume, mortality due to senescence decreases if the proportion of large trees decreases as overall density increases. This size-related reduction in mortality offsets the density-related increase in mortality, resulting in a 40% increase in yield. CONCLUSIONS: Size-related variation in growth and mortality exerts a profound influence on the relationship between stand structure and productivity. Dense stands dominated by small trees yield more wood than stands dominated by fewer

  3. Variability in estimation of self-reported dietary intake data from elite athletes resulting from coding by different sports dietitians.

    Science.gov (United States)

    Braakhuis, Andrea J; Meredith, Kelly; Cox, Gregory R; Hopkins, William G; Burke, Louise M

    2003-06-01

    A routine activity for a sports dietitian is to estimate energy and nutrient intake from an athlete's self-reported food intake. Decisions made by the dietitian when coding a food record are a source of variability in the data. The aim of the present study was to determine the variability in estimation of the daily energy and key nutrient intakes of elite athletes, when experienced coders analyzed the same food record using the same database and software package. Seven-day food records from a dietary survey of athletes in the 1996 Australian Olympic team were randomly selected to provide 13 sets of records, each set representing the self-reported food intake of an endurance, team, weight restricted, and sprint/power athlete. Each set was coded by 3-5 members of Sports Dietitians Australia, making a total of 52 athletes, 53 dietitians, and 1456 athlete-days of data. We estimated within- and between- athlete and dietitian variances for each dietary nutrient using mixed modeling, and we combined the variances to express variability as a coefficient of variation (typical variation as a percent of the mean). Variability in the mean of 7-day estimates of a nutrient was 2- to 3-fold less than that of a single day. The variability contributed by the coder was less than the true athlete variability for a 1-day record but was of similar magnitude for a 7-day record. The most variable nutrients (e.g., vitamin C, vitamin A, cholesterol) had approximately 3-fold more variability than least variable nutrients (e.g., energy, carbohydrate, magnesium). These athlete and coder variabilities need to be taken into account in dietary assessment of athletes for counseling and research.

  4. Variability in State-Dependent Plasticity of Intrinsic Properties during Cell-Autonomous Self-Regulation of Calcium Homeostasis in Hippocampal Model Neurons1,2,3

    Science.gov (United States)

    Srikanth, Sunandha

    2015-01-01

    Abstract How do neurons reconcile the maintenance of calcium homeostasis with perpetual switches in patterns of afferent activity? Here, we assessed state-dependent evolution of calcium homeostasis in a population of hippocampal pyramidal neuron models, through an adaptation of a recent study on stomatogastric ganglion neurons. Calcium homeostasis was set to emerge through cell-autonomous updates to 12 ionic conductances, responding to different types of synaptically driven afferent activity. We first assessed the impact of theta-frequency inputs on the evolution of ionic conductances toward maintenance of calcium homeostasis. Although calcium homeostasis emerged efficaciously across all models in the population, disparate changes in ionic conductances that mediated this emergence resulted in variable plasticity to several intrinsic properties, also manifesting as significant differences in firing responses across models. Assessing the sensitivity of this form of plasticity, we noted that intrinsic neuronal properties and the firing response were sensitive to the target calcium concentration and to the strength and frequency of afferent activity. Next, we studied the evolution of calcium homeostasis when afferent activity was switched, in different temporal sequences, between two behaviorally distinct types of activity: theta-frequency inputs and sharp-wave ripples riding on largely silent periods. We found that the conductance values, intrinsic properties, and firing response of neurons exhibited differential robustness to an intervening switch in the type of afferent activity. These results unveil critical dissociations between different forms of homeostasis, and call for a systematic evaluation of the impact of state-dependent switches in afferent activity on neuronal intrinsic properties during neural coding and homeostasis. PMID:26464994

  5. Polishing tool and the resulting TIF for three variable machine parameters as input for the removal simulation

    Science.gov (United States)

    Schneider, Robert; Haberl, Alexander; Rascher, Rolf

    2017-06-01

    The trend in the optic industry shows, that it is increasingly important to be able to manufacture complex lens geometries on a high level of precision. From a certain limit on the required shape accuracy of optical workpieces, the processing is changed from the two-dimensional to point-shaped processing. It is very important that the process is as stable as possible during the in point-shaped processing. To ensure stability, usually only one process parameter is varied during processing. It is common that this parameter is the feed rate, which corresponds to the dwell time. In the research project ArenA-FOi (Application-oriented analysis of resource-saving and energy-efficient design of industrial facilities for the optical industry), a touching procedure is used in the point-attack, and in this case a close look is made as to whether a change of several process parameters is meaningful during a processing. The ADAPT tool in size R20 from Satisloh AG is used, which is also available for purchase. The behavior of the tool is tested under constant conditions in the MCP 250 CNC by OptoTech GmbH. A series of experiments should enable the TIF (tool influence function) to be determined using three variable parameters. Furthermore, the maximum error frequency that can be processed is calculated as an example for one parameter set and serves as an outlook for further investigations. The test results serve as the basic for the later removal simulation, which must be able to deal with a variable TIF. This topic has already been successfully implemented in another research project of the Institute for Precision Manufacturing and High-Frequency Technology (IPH) and thus this algorithm can be used. The next step is the useful implementation of the collected knowledge. The TIF must be selected on the basis of the measured data. It is important to know the error frequencies to select the optimal TIF. Thus, it is possible to compare the simulated results with real measurement

  6. Planck intermediate results. XXII. Frequency dependence of thermal emission from Galactic dust in intensity and polarization

    CERN Document Server

    Ade, P A R; Aniano, G; Armitage-Caplan, C; Arnaud, M; Atrio-Barandela, F; Aumont, J; Baccigalupi, C; Banday, A J; Barreiro, R B; Battaner, E; Benabed, K; Benoit-Lévy, A; Bernard, J -P; Bersanelli, M; Bielewicz, P; Bock, J J; Bond, J R; Borrill, J; Bouchet, F R; Boulanger, F; Burigana, C; Cardoso, J -F; Catalano, A; Chamballu, A; Chiang, H C; Colombo, L P L; Combet, C; Couchot, F; Coulais, A; Crill, B P; Curto, A; Cuttaia, F; Danese, L; Davies, R D; Davis, R J; de Bernardis, P; de Zotti, G; Delabrouille, J; Désert, F -X; Dickinson, C; Diego, J M; Donzelli, S; Doré, O; Douspis, M; Dunkley, J; Dupac, X; Enßlin, T A; Eriksen, H K; Falgarone, E; Fanciullo, L; Finelli, F; Forni, O; Frailis, M; Fraisse, A A; Franceschi, E; Galeotta, S; Ganga, K; Ghosh, T; Giard, M; González-Nuevo, J; Górski, K M; Gregorio, A; Gruppuso, A; Guillet, V; Hansen, F K; Harrison, D L; Helou, G; Hernández-Monteagudo, C; Hildebrandt, S R; Hivon, E; Hobson, M; Holmes, W A; Hornstrup, A; Jaffe, A H; Jaffe, T R; Jones, W C; Keihänen, E; Keskitalo, R; Kisner, T S; Kneissl, R; Knoche, J; Kunz, M; Kurki-Suonio, H; Lagache, G; Lamarre, J -M; Lasenby, A; Lawrence, C R; Leahy, J P; Leonardi, R; Levrier, F; Liguori, M; Lilje, P B; Linden-Vørnle, M; López-Caniego, M; Lubin, P M; Macías-Pérez, J F; Maffei, B; Magalhães, A M; Maino, D; Mandolesi, N; Maris, M; Marshall, D J; Martin, P G; Martínez-González, E; Masi, S; Matarrese, S; Mazzotta, P; Melchiorri, A; Mendes, L; Mennella, A; Migliaccio, M; Miville-Deschênes, M -A; Moneti, A; Montier, L; Morgante, G; Mortlock, D; Munshi, D; Murphy, J A; Naselsky, P; Nati, F; Natoli, P; Netterfield, C B; Noviello, F; Novikov, D; Novikov, I; Oppermann, N; Oxborrow, C A; Pagano, L; Pajot, F; Paoletti, D; Pasian, F; Perdereau, O; Perotto, L; Perrotta, F; Piacentini, F; Pietrobon, D; Plaszczynski, S; Pointecouteau, E; Polenta, G; Popa, L; Pratt, G W; Rachen, J P; Reach, W T; Reinecke, M; Remazeilles, M; Renault, C; Ricciardi, S; Riller, T; Ristorcelli, I; Rocha, G; Rosset, C; Roudier, G; Rubiño-Martín, J A; Rusholme, B; Salerno, E; Sandri, M; Savini, G; Scott, D; Spencer, L D; Stolyarov, V; Stompor, R; Sudiwala, R; Sutton, D; Suur-Uski, A -S; Sygnet, J -F; Tauber, J A; Terenzi, L; Toffolatti, L; Tomasi, M; Tristram, M; Tucci, M; Valenziano, L; Valiviita, J; Van Tent, B; Vielva, P; Villa, F; Wandelt, B D; Zacchei, A; Zonca, A

    2014-01-01

    Planck has mapped the intensity and polarization of the sky at microwave frequencies with unprecedented sensitivity. We make use of the Planck 353 GHz I, Q, and U Stokes maps as dust templates, and cross-correlate them with the Planck and WMAP data at 12 frequencies from 23 to 353 GHz, over circular patches with 10 degree radius. The cross-correlation analysis is performed for both intensity and polarization data in a consistent manner. We use a mask that focuses our analysis on the diffuse interstellar medium at intermediate Galactic latitudes. We determine the spectral indices of dust emission in intensity and polarization between 100 and 353 GHz, for each sky-patch. The mean values, $1.63\\pm0.03$ for polarization and $1.52\\pm0.02$ for intensity, for a mean dust temperature of 18.7 K, are close, but significantly different. We determine the mean spectral energy distribution (SED) of the microwave emission, correlated with the 353 GHz dust templates, by averaging the results of the correlation over all sky-p...

  7. Azimuthal Dependence of the Ground Motion Variability from Scenario Modeling of the 2014 Mw6.0 South Napa, California, Earthquake Using an Advanced Kinematic Source Model

    Science.gov (United States)

    Gallovič, F.

    2016-11-01

    Strong ground motion simulations require physically plausible earthquake source model. Here, I present the application of such a kinematic model introduced originally by Ruiz et al. (Geophys J Int 186:226-244, 2011). The model is constructed to inherently provide synthetics with the desired omega-squared spectral decay in the full frequency range. The source is composed of randomly distributed overlapping subsources with fractal number-size distribution. The position of the subsources can be constrained by prior knowledge of major asperities (stemming, e.g., from slip inversions), or can be completely random. From earthquake physics point of view, the model includes positive correlation between slip and rise time as found in dynamic source simulations. Rupture velocity and rise time follows local S-wave velocity profile, so that the rupture slows down and rise times increase close to the surface, avoiding unrealistically strong ground motions. Rupture velocity can also have random variations, which result in irregular rupture front while satisfying the causality principle. This advanced kinematic broadband source model is freely available and can be easily incorporated into any numerical wave propagation code, as the source is described by spatially distributed slip rate functions, not requiring any stochastic Green's functions. The source model has been previously validated against the observed data due to the very shallow unilateral 2014 Mw6 South Napa, California, earthquake; the model reproduces well the observed data including the near-fault directivity (Seism Res Lett 87:2-14, 2016). The performance of the source model is shown here on the scenario simulations for the same event. In particular, synthetics are compared with existing ground motion prediction equations (GMPEs), emphasizing the azimuthal dependence of the between-event ground motion variability. I propose a simple model reproducing the azimuthal variations of the between-event ground motion

  8. How stand productivity results from size- and competition-dependent growth and mortality.

    Science.gov (United States)

    Caspersen, John P; Vanderwel, Mark C; Cole, William G; Purves, Drew W

    2011-01-01

    A better understanding of the relationship between stand structure and productivity is required for the development of: a) scalable models that can accurately predict growth and yield dynamics for the world's forests; and b) stand management regimes that maximize wood and/or timber yield, while maintaining structural and species diversity. We develop a cohort-based canopy competition model ("CAIN"), parameterized with inventory data from Ontario, Canada, to examine the relationship between stand structure and productivity. Tree growth, mortality and recruitment are quantified as functions of diameter and asymmetric competition, using a competition index (CAI(h)) defined as the total projected area of tree crowns at a given tree's mid-crown height. Stand growth, mortality, and yield are simulated for inventoried stands, and also for hypothetical stands differing in total volume and tree size distribution. For a given diameter, tree growth decreases as CAI(h) increases, whereas the probability of mortality increases. For a given CAI(h), diameter growth exhibits a humped pattern with respect to diameter, whereas mortality exhibits a U-shaped pattern reflecting senescence of large trees. For a fixed size distribution, stand growth increases asymptotically with total density, whereas mortality increases monotonically. Thus, net productivity peaks at an intermediate volume of 100-150 m(3)/ha, and approaches zero at 250 m(3)/ha. However, for a fixed stand volume, mortality due to senescence decreases if the proportion of large trees decreases as overall density increases. This size-related reduction in mortality offsets the density-related increase in mortality, resulting in a 40% increase in yield. Size-related variation in growth and mortality exerts a profound influence on the relationship between stand structure and productivity. Dense stands dominated by small trees yield more wood than stands dominated by fewer large trees, because the relative growth rate of small

  9. RESULTS OF SUGAR BEET PRODUCTION DEPENDING ON THE HYBRIDS SELECTION AND THE NUMBER OF FUNGICIDE APPLICATION

    Directory of Open Access Journals (Sweden)

    Andrija Kristek

    2015-12-01

    Full Text Available The study of the production values of 10 sugar beet hybrids was conducted on chernozem soil type in Eastern Croatia (Tovarniklocation. The used treatments with and without fungicides application were investigated in 2013 and 2014. Sugar beet hybrids used in the study originate from three market-leading sugar beet seed companies in Croatia, whose varieties provide disease tolerance to C. beticola. The years of the study were quite warm with higher mean monthly air temperature (°C and increased amount of rainfall, as compared to the long-term mean. In the second year of the study, due to increased amount of rainfall (mm in July and August, as well as the total loss ofstrobilurin efficiency and low effectiveness ofthe cyproconazole treatment, the destruction ofthe leaves by C. beticola Sacc. was significantly higher. The results of the study showed a huge coherence of sugar beet yield and quality with leaf conservation through the vegetation (the number of treatment, and with the hybrids. Due to leaves destruction on control treatments, as compared to fungicide application three times, the sugar beet root yield was reduced on the average by 9.79 t ha'1 (10.03%, sugar content by 0.69% (rel. 4.89% and sugar yield by 2.041 ha1 (17.04%. On the other hand, three fungicide applications increased the root yield by 4.881 ha1 (5.26%, sugar content by 0.52% and sugar yield by 0.99 t ha1 (9.01% as compared to one fungicide application. All sugar beet hybrids of the study were strongly negatively affected the control treatment, indicating repeated fungicide application against C. beticola as a regular agricultural practices. On the average, for all variations of fungicides applications, the sugar beet hybrid Jadranka had significantly higher root yield in comparison with other hybrids included in the study. Moreover, the highest sugar content achieved Sandor, Marianka and Kundera. Significantly higher sugar yield had a hybrid Jadranka.

  10. MRI screening for silicone breast implant rupture: accuracy, inter- and intraobserver variability using explantation results as reference standard

    Energy Technology Data Exchange (ETDEWEB)

    Maijers, M.C.; Ritt, M.J.P.F. [VU University Medical Centre, Department of Plastic, Reconstructive and Hand Surgery, De Boelelaan 1117, PO Box 7057, Amsterdam (Netherlands); Niessen, F.B. [VU University Medical Centre, Department of Plastic, Reconstructive and Hand Surgery, De Boelelaan 1117, PO Box 7057, Amsterdam (Netherlands); Jan van Goyen Clinic, Department of Plastic Surgery, Amsterdam (Netherlands); Veldhuizen, J.F.H. [MRI Centre, Amsterdam (Netherlands); Manoliu, R.A. [MRI Centre, Amsterdam (Netherlands); VU University Medical Centre, Department of Radiology, Amsterdam (Netherlands)

    2014-06-15

    The recall of Poly Implant Prothese (PIP) silicone breast implants in 2010 resulted in large numbers of asymptomatic women with implants who underwent magnetic resonance imaging (MRI) screening. This study's aim was to assess the accuracy and interobserver variability of MRI screening in the detection of rupture and extracapsular silicone leakage. A prospective study included 107 women with 214 PIP implants who underwent explantation preceded by MRI. In 2013, two radiologists blinded for previous MRI findings or outcome at surgery, independently re-evaluated all MRI examinations. A structured protocol described the MRI findings. The ex vivo findings served as reference standard. In 208 of the 214 explanted prostheses, radiologists agreed independently about the condition of the implants. In five of the six cases they disagreed (2.6 %), but subsequently reached consensus. A sensitivity of 93 %, specificity of 93 %, positive predictive value of 77 % and negative predictive value of 98 % was found. The interobserver agreement was excellent (kappa value of 0.92). MRI has a high accuracy in diagnosing rupture in silicone breast implants. Considering the high kappa value of interobserver agreement, MRI appears to be a consistent diagnostic test. A simple, uniform classification, may improve communication between radiologist and plastic surgeon. (orig.)

  11. Multifractal analysis of heart rate variability and laser Doppler flowmetry fluctuations:comparison of results from different numerical methods

    Energy Technology Data Exchange (ETDEWEB)

    Humeau, Anne; Buard, Benjamin; Chapeau-Blondeau, Francois; Rousseau, David [Laboratoire d' Ingenierie des Systemes Automatises (LISA), Universite d' Angers, 62 avenue Notre Dame du Lac, 49000 Angers (France); Mahe, Guillaume; Abraham, Pierre, E-mail: anne.humeau@univ-angers.f [Laboratoire de Physiologie et d' Explorations Vasculaires, UMR CNRS 6214-INSERM 771, Centre Hospitalier Universitaire d' Angers, 49033 Angers cedex 01 (France)

    2010-10-21

    To contribute to the understanding of the complex dynamics in the cardiovascular system (CVS), the central CVS has previously been analyzed through multifractal analyses of heart rate variability (HRV) signals that were shown to bring useful contributions. Similar approaches for the peripheral CVS through the analysis of laser Doppler flowmetry (LDF) signals are comparatively very recent. In this direction, we propose here a study of the peripheral CVS through a multifractal analysis of LDF fluctuations, together with a comparison of the results with those obtained on HRV fluctuations simultaneously recorded. To perform these investigations concerning the biophysics of the CVS, first we have to address the problem of selecting a suitable methodology for multifractal analysis, allowing us to extract meaningful interpretations on biophysical signals. For this purpose, we test four existing methodologies of multifractal analysis. We also present a comparison of their applicability and interpretability when implemented on both simulated multifractal signals of reference and on experimental signals from the CVS. One essential outcome of the study is that the multifractal properties observed from both the LDF fluctuations (peripheral CVS) and the HRV fluctuations (central CVS) appear very close and similar over the studied range of scales relevant to physiology.

  12. Multifractal analysis of heart rate variability and laser Doppler flowmetry fluctuations:comparison of results from different numerical methods

    Science.gov (United States)

    Humeau, Anne; Buard, Benjamin; Mahé, Guillaume; Chapeau-Blondeau, François; Rousseau, David; Abraham, Pierre

    2010-10-01

    To contribute to the understanding of the complex dynamics in the cardiovascular system (CVS), the central CVS has previously been analyzed through multifractal analyses of heart rate variability (HRV) signals that were shown to bring useful contributions. Similar approaches for the peripheral CVS through the analysis of laser Doppler flowmetry (LDF) signals are comparatively very recent. In this direction, we propose here a study of the peripheral CVS through a multifractal analysis of LDF fluctuations, together with a comparison of the results with those obtained on HRV fluctuations simultaneously recorded. To perform these investigations concerning the biophysics of the CVS, first we have to address the problem of selecting a suitable methodology for multifractal analysis, allowing us to extract meaningful interpretations on biophysical signals. For this purpose, we test four existing methodologies of multifractal analysis. We also present a comparison of their applicability and interpretability when implemented on both simulated multifractal signals of reference and on experimental signals from the CVS. One essential outcome of the study is that the multifractal properties observed from both the LDF fluctuations (peripheral CVS) and the HRV fluctuations (central CVS) appear very close and similar over the studied range of scales relevant to physiology.

  13. Relationship of Speed, Agility, Neuromuscular Power, and Selected Anthropometrical Variables and Performance Results of Male and Female Junior Tennis Players.

    Science.gov (United States)

    Munivrana, Goran; Filipčić, Aleš; Filipčić, Tjaša

    2015-07-01

    The aim of the study was to analyses the relation between the selected speed, agility, and neuromuscular power test items. The sample of subjects consisted of 154 male and 152 female young tennis players. Using six motor and three anthropometrical tests we investigate differences between males and females and between two age categories. Finally, we analyzed the relation between motor and anthropometrical tests and a player's tennis performance. The correlation between the two agility test items and 5-m sprint is very large in male players, while only moderate with 20-m sprint in female category. Male tennis players have higher correlations between speed test items and neuromuscular test items. The speed test item (5-m sprint) has large correlation with a player's tennis performance. One-way analysis of variance results indicated that young male tennis players performed significantly better than females in all motor test items. Significant differences between genders have not been revealed only in the body mass index. Differences between the males aged 18& under and 16& under have been noted as significant in all test items, except the vertical jump, while differences between the females have been noted as significant in three anthropometrical tests, quarter jump, and the fan-drill test. Regression analyses have shown that the system of prediction variables explains a relatively small part of variance (46%--males and 40%--females). In both genders, it has been revealed that test items measuring speed significantly influence a player's tennis performance.

  14. Variability in blood oxygen level dependent (BOLD signal in patients with stroke-induced and primary progressive aphasia

    Directory of Open Access Journals (Sweden)

    B. Bonakdarpour

    2015-01-01

    Full Text Available Although fMRI is increasingly used to assess language-related brain activation in patients with aphasia, few studies have examined the hemodynamic response function (HRF in perilesional, and contralesional areas of the brain. In addition, the relationship between HRF abnormalities and other variables such as lesion size and severity of aphasia has not been explored. The objective of this study was to investigate changes in HRF signal during language-related neural activation in patients with stroke-induced aphasia (SA. We also examined the status of the HRF in patients with aphasia due to nonvascular etiology, namely, primary progressive aphasia (PPA. Five right handed SA patients, three PPA patients, and five healthy individuals participated in the study. Structural damage was quantified with T1-weighted MR images. Functional MR imaging was performed with long trial event-related design and an overt naming task to measure BOLD signal time to peak (TTP and percent signal change (ΔS. In SA patients, the average HRF TTP was significantly delayed in the left hemisphere regions involved in naming compared to healthy participants and PPA patients. However, ΔS was not different in SA patients compared to the other two groups. Delay in HRF TTP in the left hemisphere naming network of SA patients was correlated with lesion size and showed a negative correlation with global language function. There were no significant differences in the HRF TTP and ΔS in the right hemisphere homologues of the naming network or in the left and the right occipital control regions across the three groups. In PPA patients, HRF had a normal pattern. Our results indicate that abnormal task-related HRF is primarily found in the left hemisphere language network of SA patients and raise the possibility that abnormal physiology superimposed on structural damage may contribute to the clinical deficit. Follow-up investigations in a larger sample of age-matched healthy individuals

  15. Existence and controllability results for damped second order impulsive functional differential systems with state-dependent delay

    Directory of Open Access Journals (Sweden)

    M. Mallika Arjunan

    2014-01-01

    Full Text Available In this paper, we investigate the existence and controllability of mild solutions for a damped second order impulsive functional differential equation with state-dependent delay in Banach spaces. The results are obtained by using Sadovskii's fixed point theorem combined with the theories of a strongly continuous cosine family of bounded linear operators. Finally, an example is provided to illustrate the main results.

  16. How many replicate tests do I need?$-$ Variability of cookstove performance and emissions has implications for obtaining useful results

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yungang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Sohn, Michael D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Gadgil, Ashok J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division; Wang, Yilun [ISO Innovative Analytics San Francisco, CA (United States); Lask, Kathleen M. [Univ. of California, Berkeley, CA (United States). College of Engineering Applied Science and Technology Program; Kirchstetter, Thomas W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Environmental Energy Technologies Division

    2013-02-01

    Almost half of the world’s population still cooks on biomass cookstoves of poor efficiency and primitive design, such as three stone fires (TSF). Emissions from biomass cookstoves contribute to adverse health effects and climate change. A number of “improved cookstoves” with higher energy efficiency and lower emissions have been designed and promoted across the world. During the design development, and for selection of a stove for dissemination, the stove performance and emissions are commonly evaluated, communicated and compared using the arithmetic average of replicate tests made using a standardized laboratory-based test, commonly the water boiling test (WBT). However, published literature shows different WBT results reported from different laboratories for the same stove technology. Also, there is no agreement in the literature on how many replicate tests should be performed to ensure “significance” in the reported average performance. This matter has not received attention in the rapidly growing literature on stoves, and yet is crucial for estimating and communicating the performance of a stove, and for comparing the performance between stoves. We present results of statistical analyses using data from a number of replicate tests of performance and emission of the Berkeley-Darfur Stove (BDS) and the TSF under well-controlled laboratory conditions. We observed moderate variability in the test results for the TSF and BDS when measuring several characteristics. Here we focus on two as illustrative: time-to-boil and PM2.5 (particulate matter less than or equal to 2.5 micrometers in diameter) emissions. We demonstrate that interpretation of the results comparing these stoves could be misleading if only a small number of replicates had been conducted. We then describe a practical approach, useful to both stove testers and designers, to assess the number of replicates needed to obtain useful data. Caution should be exercised in attaching high credibility to

  17. Analysis of Student and School Level Variables Related to Mathematics Self-Efficacy Level Based on PISA 2012 Results for China-Shanghai, Turkey, and Greece

    Science.gov (United States)

    Usta, H. Gonca

    2016-01-01

    This study aims to analyze the student and school level variables that affect students' self-efficacy levels in mathematics in China-Shanghai, Turkey, and Greece based on PISA 2012 results. In line with this purpose, the hierarchical linear regression model (HLM) was employed. The interschool variability is estimated at approximately 17% in…

  18. Identifying long-term variations in vegetation and climatic variables and their scale-dependent relationships: A case study in Southwest Germany

    Science.gov (United States)

    Liu, Zhiyong; Menzel, Lucas

    2016-12-01

    and precipitation regimes. For the scale-dependent relationships between NDVI and precipitation, the 2-month and 8-month scales generally present the strongest negative correlation. The most significant positive correlations between NDVI and temperature are obtained at the 8- to 16-month scales for most vegetation types. The results of the present study might be beneficial for water resources management as well as agricultural and ecological development planning in Rhineland-Palatinate, and also provide a helpful reference for other regions with similar climate condition.

  19. A Pareto-Based Adaptive Variable Neighborhood Search for Biobjective Hybrid Flow Shop Scheduling Problem with Sequence-Dependent Setup Time

    Directory of Open Access Journals (Sweden)

    Huixin Tian

    2016-01-01

    Full Text Available Different from most researches focused on the single objective hybrid flowshop scheduling (HFS problem, this paper investigates a biobjective HFS problem with sequence dependent setup time. The two objectives are the minimization of total weighted tardiness and the total setup time. To efficiently solve this problem, a Pareto-based adaptive biobjective variable neighborhood search (PABOVNS is developed. In the proposed PABOVNS, a solution is denoted as a sequence of all jobs and a decoding procedure is presented to obtain the corresponding complete schedule. In addition, the proposed PABOVNS has three major features that can guarantee a good balance of exploration and exploitation. First, an adaptive selection strategy of neighborhoods is proposed to automatically select the most promising neighborhood instead of the sequential selection strategy of canonical VNS. Second, a two phase multiobjective local search based on neighborhood search and path relinking is designed for each selected neighborhood. Third, an external archive with diversity maintenance is adopted to store the nondominated solutions and at the same time provide initial solutions for the local search. Computational results based on randomly generated instances show that the PABOVNS is efficient and even superior to some other powerful multiobjective algorithms in the literature.

  20. Planting strategies of maize farmers in Kenya: a simultaneous equations analysis in the presence of discrete dependent variables

    CSIR Research Space (South Africa)

    Hassan, RM

    1996-11-01

    Full Text Available - rectly through its influence on cropping intensity (Yl). Female farmers may have preferences for cer- tain varietal traits, that may be different from those of male farmers. Again, experience and knowledge (age, education... of family size and available farm land. 4. The sex, education, and age of the farmer. Whereas the age variable is measured on a continuous scale, dichotomous indices are used to code sex (male, female) and education (none...

  1. Variable Stars in the LMC Globular Cluster NGC 2257 New: Results Based on 2007-08 B, V Photometry

    Science.gov (United States)

    Nemec, James M.; Walker, Alistair R.; Jeon, Young-Beom

    2009-09-01

    The variable star population in the Large Magellanic Cloud outer-halo globular cluster NGC 2257 has been reinvestigated using photometry (to ~20th mag) of over 400 new B, V CCD images taken with the CTIO 0.9-m telescope on 14 nights in Dec'07 and Jan'08. The derived periods of most of the stars are consistent with the pulsation periods derived previously, and where there were discrepancies these have been resolved. Accurate Fourier coefficients and parameters were computed for the B and V light curves. Six new variable stars were discovered (V45-V50), including a bright candidate long-period variable star showing secondary oscillations (V45). Examination of archival HST images and previously-published photometry shows that the excess brightness of two bright RR Lyrae stars (V48, V50) is due to contamination from close red giant branch stars. Among the previously known variable stars three double-mode (RRd) RR Lyrae stars (V8, V16 and V34) and several Blazhko variables were discovered. The total number of cluster variable stars now stands at forty-seven: 23 RRab stars, four of which show Blazhko light-curve variations; 20 RRc stars, one showing clear Blazhko variations and another showing possible Blazhko variations; the three RRd stars, all having the dominant period ~0.36 day and period ratios P1/P0~0.7450, and the LPV located near the tip of the red giant branch. A comparison with similar stars in other environments shows that the RRd stars in NGC 2257 are most similar to those in IC 4499.

  2. [Dependence of effects of weak combined low-frequency variable and constant magnetic fields on the intensity of asexual reproduction of planarians Dugesia tigrina on the magnitude of the variable field].

    Science.gov (United States)

    Novikov, V V; Sheĭman, I M; Lisitsyn, A S; Kliubin, A V; Fesenko, E E

    2002-01-01

    It was shown that the stimulating effect of weak combined magnetic fields (constant component 42 microT, frequency of the variable component 3.7 Hz) on the division of planarians depends on the amplitude of the variable component of the field. The effect is particularly pronounced at 40 (the main maximum), 120, 160, and 640 nT. Narrow ranges of effective amplitudes alternate in some cases with equally narrow ranges in which the system does not respond to he treatment. In the range of super weak amplitudes of the variable field (0.1 and 1 nT), the stimulating effect is poorly pronounced. The data obtained indicate the presence of narrow amplitude windows in the response of the biological systems to weak and super weak magnetic fields. In a special series of experiments, it was shown that the effect of fields on planarians is partially mediated via aqueous medium preliminarily treated with weak magnetic fields. It is noteworthy that in experiments with water treated with weak magnetic fields, there were no pronounced maxima and minima in the magnitude of the effect in the range of amplitude of the variable magnetic field from 40 to 320 nT.

  3. Restored river corridors: first results on the effects of flow variability on vegetation cuttings survival rate and related root architecture

    Science.gov (United States)

    Pasquale, N.; Perona, P.; Jiang, Z.; Burlando, P.

    2009-04-01

    Understanding and predicting the evolution of river alluvial bed forms toward a vegetated or a non-vegetated morphology have important implications for restored river corridors and the related ecosystem functioning (see also Schäppi et al, this session). Vegetation recruitment and growth on non-cohesive material of river corridors, such as gravel bars and islands of braided river, depend on the ability of roots to develop and anchor efficiently such to resist against flow erosion. In this work, we study the interannual morphological evolution of a gravel bar island, the survival rate and the growth of a number of plots with different density and orientation of transplanted cuttings (Salix Alba), the space and time dynamics of which depend on erosion and deposition processes due to floods. Our purpose is to identify island locations where the hydrodynamic conditions are more suitable for plants germination, growth and survival in relation to the river hydrograph statistics. This information is a first step to build a stochastic model able to predict the future evolution and progress of the restoration action of the investigated river reach. We focus at the main island of River Thur at Niederneunforn (Canton Thurgau, Switzerland), the restoration success of which is investigated from a mechanistic viewpoint in the research project "REstored CORridor Dynamics" (www.record.ethz.ch). Accordingly, we analyze two recent Digital Elevation Models (1 year difference), which were first corrected to account for the river bathymetry, and then we compare them in order to extract relevant interannual morphological changes. Using a two dimensional numerical hydrodynamic model we simulate several flow conditions ranging from the minimum recorded flow up to the one that completely inundates the island. Hence, we build inundation maps of the island that we associate to the frequency and the submergence duration of every area. We then correlate such results to the observed survival

  4. Variability of photovoltaic panels efficiency depending on the value of the angle of their inclination relative to the horizon

    Directory of Open Access Journals (Sweden)

    Majdak Marek

    2017-01-01

    Full Text Available The objective of this paper was to determine the relationship between the efficiency of photovoltaic panels and the value of the angle of their inclination relative to the horizon. For the purpose of experimental research have been done tests on the photovoltaic modules made of monocrystalline, polycrystalline and amorphous silicon. The experiment consisted of measurement of the voltage and current generated by photovoltaic panels at a known value of solar radiation and a specified resistance value determined by using resistor with variable value of resistance and known value of the angle of their inclination relative to the horizon.

  5. Statistical Frequency-Dependent Analysis of Trial-to-Trial Variability in Single Time Series by Recurrence Plots.

    Science.gov (United States)

    Tošić, Tamara; Sellers, Kristin K; Fröhlich, Flavio; Fedotenkova, Mariia; Beim Graben, Peter; Hutt, Axel

    2015-01-01

    For decades, research in neuroscience has supported the hypothesis that brain dynamics exhibits recurrent metastable states connected by transients, which together encode fundamental neural information processing. To understand the system's dynamics it is important to detect such recurrence domains, but it is challenging to extract them from experimental neuroscience datasets due to the large trial-to-trial variability. The proposed methodology extracts recurrent metastable states in univariate time series by transforming datasets into their time-frequency representations and computing recurrence plots based on instantaneous spectral power values in various frequency bands. Additionally, a new statistical inference analysis compares different trial recurrence plots with corresponding surrogates to obtain statistically significant recurrent structures. This combination of methods is validated by applying it to two artificial datasets. In a final study of visually-evoked Local Field Potentials in partially anesthetized ferrets, the methodology is able to reveal recurrence structures of neural responses with trial-to-trial variability. Focusing on different frequency bands, the δ-band activity is much less recurrent than α-band activity. Moreover, α-activity is susceptible to pre-stimuli, while δ-activity is much less sensitive to pre-stimuli. This difference in recurrence structures in different frequency bands indicates diverse underlying information processing steps in the brain.

  6. The impact of clinical and demographic variables on cognitive performance in methamphetamine-dependent individuals in rural South Carolina.

    Science.gov (United States)

    Price, Kimber L; DeSantis, Stacia M; Simpson, Annie N; Tolliver, Bryan K; McRae-Clark, Aimee L; Saladin, Michael E; Baker, Nathaniel L; Wagner, Mark T; Brady, Kathleen T

    2011-01-01

    Inconsistencies in reports on methamphetamine (METH) associated cognitive dysfunction may be attributed, at least in part, to the diversity of study sample features (eg, clinical and demographic characteristics). The current study assessed cognitive function in a METH-dependent population from rural South Carolina, and the impact of demographic and clinical characteristics on performance. Seventy-one male (28.2%) and female (71.8%) METH-dependent subjects were administered a battery of neurocognitive tests including the Test of Memory Malingering (TOMM), Shipley Institute of Living Scale, Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Grooved Pegboard Test, California Verbal Learning Test (CVLT), and Wisconsin Card Sorting Test (WCST). Demographic and clinical characteristics (eg, gender, frequency of METH use) were examined as predictors of performance. Subjects scored significantly lower than expected on one test of attention and one of fine motor function, but performed adequately on all other tests. There were no predictors of performance on attention; however, more frequent METH use was associated with better performance for males and worse for females on fine motor skills. The METH-dependent individuals in this population exhibit very limited cognitive impairment. The marked differences in education, Intellectual Quotient (IQ), and gender in our sample when compared to the published literature may contribute to these findings. Characterization of the impact of clinical and/or demographic features on cognitive deficits could be important in guiding the development of treatment interventions. © American Academy of Addiction Psychiatry.

  7. Study of time reversibility/irreversibility of cardiovascular data: theoretical results and application to laser Doppler flowmetry and heart rate variability signals

    Science.gov (United States)

    Humeau-Heurtier, Anne; Mahé, Guillaume; Chapeau-Blondeau, François; Rousseau, David; Abraham, Pierre

    2012-07-01

    Time irreversibility can be qualitatively defined as the degree of a signal for temporal asymmetry. Recently, a time irreversibility characterization method based on entropies of positive and negative increments has been proposed for experimental signals and applied to heart rate variability (HRV) data (central cardiovascular system (CVS)). The results led to interesting information as a time asymmetry index was found different for young subjects and elderly people or heart disease patients. Nevertheless, similar analyses have not yet been conducted on laser Doppler flowmetry (LDF) signals (peripheral CVS). We first propose to further investigate the above-mentioned characterization method. Then, LDF signals, LDF signals reduced to samples acquired during ECG R peaks (LDF_RECG signals) and HRV recorded simultaneously in healthy subjects are processed. Entropies of positive and negative increments for LDF signals show a nonmonotonic pattern: oscillations—more or less pronounced, depending on subjects—are found with a period matching the one of cardiac activity. However, such oscillations are not found with LDF_RECG nor with HRV. Moreover, the asymmetry index for LDF is markedly different from the ones of LDF_RECG and HRV. The cardiac activity may therefore play a dominant role in the time irreversibility properties of LDF signals.

  8. Variability in upwelling intensity and nutrient regime in the coastal upwelling system offshore Namibia: results from sediment archives

    Science.gov (United States)

    Emeis, Kay-Christian; Struck, Ulrich; Leipe, Thomas; Ferdelman, Timothy G.

    2009-03-01

    The coastal upwelling system offshore Namibia is ideally suited to address a focal question of the Integrated Marine Biogeochemistry and Ecosystem Research Programme: what are the mechanisms that drive long-term changes in ecosystems? Considerable interannual variability in climatic forcing is indicated by long time series of meteorological and remote sensing observation; these accompany considerable interannual to interdecadal changes in the upwelling intensity over the last 100 years, as well as a centennial trend. On longer time scales, the only archives available are sediment records spanning the late Holocene. To decipher the sediment record, we mapped surface-sediment patterns of proxies for physical (sea surface temperature/SST from alkenone unsaturation indexes) and nutrient (δ15N on bulk sedimentary N) variables. Their present-day surface-sediment patterns outline the coastal upwelling cells and filaments and associated high productivity area. Analysed in an array of dated sediment cores, the spatial patterns of SST suggest long-term (>100 years) variability in the location and intensity of individual upwelling cells. The patterns of δ15N outline an area of intense denitrification near the coast, and advection of water with low-oxygen concentrations in the undercurrent from the North. δ15N exhibits considerable downcore variability, in particular over the last 50 years. The variability appears to be governed by differences in extent of denitrification and thus of the shelf oxygen balance, which appears to have deteriorated in the last 50 years. Together, the data suggest that SST and denitrification conditions have remained in the narrow bounds outlined by today’s patterns in surface sediments, but that spatially small variability in upwelling intensity and make-up of upwelling feed waters induced considerable changes in the lower trophic levels of the coastal upwelling ecosystem over the last 6,000 years. Attempts to correlate proxy records from

  9. New Variable Stars Discovered by Data Mining Images Taken During Recent Asteroid Photometric Observations. Results from the Year 2015

    Science.gov (United States)

    Papini, R.; Franco, L.; Marchini, A.; Salvaggio, F.

    2015-12-01

    During the past year the authors observed several asteroids for the purpose of determining the rotational period. Typically, this task requires a time series images acquisition on a single field for all the night, weather permitting, for a few nights although not consecutive. Routinely checking this "goldmine," allowed us to discover 14 variable stars not yet listed in catalogs or databases. While the most of the new variables are eclipsing binaries (GSC 01394-01889, GSC 00853-00371, CSS_J171124.7-004042, GSC05065-00218, UCAC4-386-142199, UCAC4 398-127457, UCAC4 384-148138, UCAC4 398-127590, UCAC4-383-155837, GSC-05752-01113, GSC 05765-01271), a few belong to RR Lyrae class (UCAC4 388-136835, 2MASS J20060657-1230376, UCAC4 386-142583). Since asteroid work is definitely time-consuming, follow-up is quite a difficult task for a small group. Further observations of these new variables are therefore strongly encouraged in order to better characterize these stars, especially RR Lyrae ones whose data combined with those taken during professional surveys seem to suggest the presence of a Blazhko effect.

  10. The OmegaWhite Survey for short period variable stars II: An overview of results from the first four years

    CERN Document Server

    Toma, Ruxandra; MacFarlane, Sally; Groot, Paul; Woudt, Patrick; Dhillon, Vik; Jeffery, C Simon; Marsh, Tom; Nelemans, Gijs; Steeghs, Danny

    2016-01-01

    OmegaWhite is a wide-field, high cadence, synoptic survey targeting fields in the southern Galactic plane, with the aim of discovering short period variable stars. Our strategy is to take a series of 39 s exposures in the g band of a 1 square degree of sky lasting 2 h using the OmegaCAM wide field imager on the VLT Survey Telescope (VST). We give an overview of the initial 4 years of data which covers 134 square degrees and includes 12.3 million light curves. As the fields overlap with the VLT Survey Telescope Halpha Photometric Survey of the Galactic plane and Bulge (VPHAS+), we currently have $ugriH\\alpha$ photometry for ~1/3 of our fields. We find that a significant fraction of the light curves have been affected by the diffraction spikes of bright stars sweeping across stars within a few dozen of pixels over the two hour observing time interval due to the alt-az nature of the VST. We select candidate variable stars using a variety of variability statistics, followed by a manual verification stage. We pres...

  11. Clinical and scientific results in perinatal care of pregnancy complicated by insulin dependent diabetes mellitus in Croatia.

    Science.gov (United States)

    Djelmis, J

    1998-01-01

    At the Department of Obstetrics and Gynecology, Perinatal Unit for Diabetes and Fetal Growth, School of Medicine, Zagreb, perinatal care of pregnancies complicated with insulin dependent diabetes melitus (IDDM), has been performed for more than 36 years. The intention of this review is to show our own results in the management of IDDM pregnancies and the latest clinical advances in perinatal care of such pregnancies. Pregnancy complicated with IDDM is at risk because of numerous maternal, fetal and neonatal complications. Recent advances in medicine, especially in diabetology and perinatology, helps clinician avoid or lessen antenatal or perinatal complications in IDDM pregnancies. The main result of improved perinatal care is that today fetal and neonatal mortality in IDDM pregnancy is almost equal to that of healthy pregnant population. Intensive preconceptual care and optimal regulation of IDDM have resulted not only in decreased perinatal mortality but also in a decreased rate of congenital malformation. Tight glycemia control during pregnancy has a beneficial effect on fetal growth. Intensive control of fetal growth, verification of lung maturation at term by amniocenthesis, and control of fetal oxygenation will result in delivery of a mature eutrophic newborn with the lowest rate of neonatal complications possible. Perinatal mortality of less than 2% in IDDM pregnancy can be obtained by planned delivery between 38 and 39 weeks of gestation by either vaginal route or cesarean section, depending on indications. After delivery, intensive care of the newborn is necessary.

  12. Intraspecies Variability Affects Heterotypic Biofilms of Porphyromonas gingivalis and Prevotella intermedia: Evidences of Strain-Dependence Biofilm Modulation by Physical Contact and by Released Soluble Factors.

    Science.gov (United States)

    Barbosa, Graziela Murta; Colombo, Andrea Vieira; Rodrigues, Paulo Henrique; Simionato, Maria Regina Lorenzetti

    2015-01-01

    It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P. gingivalis and P

  13. Knockout of arsenic (+3 oxidation state) methyltransferase results in sex-dependent changes in phosphatidylcholine metabolism in mice.

    Science.gov (United States)

    Huang, Madelyn C; Douillet, Christelle C; Stýblo, Miroslav

    2016-12-01

    Arsenic (+3 oxidation state) methyltransferase is the key enzyme in the methylation pathway for inorganic arsenic. We have recently shown that As3mt knockout (KO) has a profound effect on metabolomic profiles in mice. Phosphatidylcholine species (PCs) were the largest group of metabolites altered in both plasma and urine. The present study used targeted analysis to investigate the KO-associated changes in PC profiles in the liver, the site of PC synthesis. Results show that As3mt KO has a systemic effect on PC metabolism and that this effect is sex dependent.

  14. Dependence of laser-induced breakdown spectroscopy results on pulse energies and timing parameters using soil simulants.

    Science.gov (United States)

    Kurek, Lauren; Najarian, Maya L; Cremers, David A; Chinni, Rosemarie C

    2013-09-23

    The dependence of some LIBS detection capabilities on lower pulse energies (<100 mJ) and timing parameters were examined using synthetic silicate samples. These samples were used as simulants for soil and contained minor and trace elements commonly found in soil at a wide range of concentrations. For this study, over 100 calibration curves were prepared using different pulse energies and timing parameters; detection limits and sensitivities were determined from the calibration curves. Plasma temperatures were also measured using Boltzmann plots for the various energies and the timing parameters tested. The electron density of the plasma was calculated using the full-width half maximum (FWHM) of the hydrogen line at 656.5 nm over the energies tested. Overall, the results indicate that the use of lower pulse energies and non-gated detection do not seriously compromise the analytical results. These results are very relevant to the design of field- and person-portable LIBS instruments.

  15. Impact of High-Cut-Off Dialysis on Renal Recovery in Dialysis-Dependent Multiple Myeloma Patients: Results from a Case-Control Study.

    Directory of Open Access Journals (Sweden)

    Hans U Gerth

    Full Text Available High-cut-off hemodialysis (HCO-HD can effectively reduce high concentrations of circulating serum free light chains (sFLC in patients with dialysis-dependent acute kidney injury (AKI due to multiple myeloma (MM. Therefore, the aim of this study was to analyze renal recovery in a retrospective single-center cohort of dialysis-dependent MM patients treated with either conventional HD (conv. HD or HCO-HD.The final cohort consisted of 59 patients treated with HCO-HD (n = 42 or conv. HD (n = 17. A sustained sFLC response was detected in a significantly higher proportion of HCO-HD patients (83.3% compared with conv. HD patients (29.4%; p = 0.007. The median duration of sFLC required to reach values <1000 mg/l was 14.5 days in the HCO-HD group and 36 days in the conv. HD group. The corresponding rates of renal recovery were 64.3% and 29.4%, respectively (chi-squared test, p = 0.014. Multivariate regression and decision tree analysis (recursive partitioning revealed HCO-HD (adjusted odds ratio [OR] 6.1 [95% confidence interval (CI 1.5-24.5], p = 0.011 and low initial uric acid values (adjusted OR 1.3 [95%CI 1.0-1.7], p = 0.045 as independent and paramount variables associated with a favorable renal outcome.In summary, the results from this retrospective case-control study suggest in addition to novel agent-based chemotherapy a benefit of HCO-HD in sFLC removal and renal outcome in dialysis-dependent AKI secondary to MM. This finding was especially pertinent in patients with low initial uric acid values, resulting in a promising renal recovery rate of 71.9%. Further prospective studies are warranted.

  16. Loss of predominant Shank3 isoforms results in hippocampus-dependent impairments in behavior and synaptic transmission.

    Science.gov (United States)

    Kouser, Mehreen; Speed, Haley E; Dewey, Colleen M; Reimers, Jeremy M; Widman, Allie J; Gupta, Natasha; Liu, Shunan; Jaramillo, Thomas C; Bangash, Muhammad; Xiao, Bo; Worley, Paul F; Powell, Craig M

    2013-11-20

    The Shank3 gene encodes a scaffolding protein that anchors multiple elements of the postsynaptic density at the synapse. Previous attempts to delete the Shank3 gene have not resulted in a complete loss of the predominant naturally occurring Shank3 isoforms. We have now characterized a homozygous Shank3 mutation in mice that deletes exon 21, including the Homer binding domain. In the homozygous state, deletion of exon 21 results in loss of the major naturally occurring Shank3 protein bands detected by C-terminal and N-terminal antibodies, allowing us to more definitively examine the role of Shank3 in synaptic function and behavior. This loss of Shank3 leads to an increased localization of mGluR5 to both synaptosome and postsynaptic density-enriched fractions in the hippocampus. These mice exhibit a decrease in NMDA/AMPA excitatory postsynaptic current ratio in area CA1 of the hippocampus, reduced long-term potentiation in area CA1, and deficits in hippocampus-dependent spatial learning and memory. In addition, these mice also exhibit motor-coordination deficits, hypersensitivity to heat, novelty avoidance, altered locomotor response to novelty, and minimal social abnormalities. These data suggest that Shank3 isoforms are required for normal synaptic transmission/plasticity in the hippocampus, as well as hippocampus-dependent spatial learning and memory.

  17. Measures of Heart Rate Variability in 24-h ECGs Depend on Age but Not Gender of Healthy Children

    Directory of Open Access Journals (Sweden)

    Waldemar Bobkowski

    2017-05-01

    Full Text Available Many methods computing heart rate variability (HRV have been applied in studies in children. Not all of these methods have a comprehensive physiological interpretation, and not all of studies are in agreement with the Task Force Standards on HRV from 1996, and the New Joint Position Statement on the advances of HRV from 2015. The study aim was to analyse HRV in the 24-h ECGs of healthy children by the Poincare plots and Lomb-Scargle periodograms, and to follow proper HRV recommendations. Additionally, we investigated the associations between age, children's sex and measured HRV indices. One hundred healthy children, aged 3–18 underwent 24-h ECG Holter monitoring. HRV was analyzed by the Poincaré plots and spectral by Lomb-Scargle periodograms of RR intervals. The Mann-Whitney test was used to compare sex differences in HRV, the van Elteren's test was used to correct for the age-gender interaction, and non-parametric Spearman correlation was applied to analyse the association between age and HRV indices. None of the HRV measures differed significantly between boys and girls. None of the HRV indices was modified by the age-gender interaction. There were statistically significant associations of age with measures of ultra-low (rho = 0.42; p < 0.0001, very low (rho = 0.35; p = 00004 and low (rho = 0.30; p = 0.0028 frequency powers, the ratio of the low to high frequency power (rho = 0.38; p = 0.0001, indices of long-term (SD2; rho = 0.37; p = 0.0002 and total (SDNN; rho = 0.33; p = 0.0008 HRV, and the contribution of the long-term HRV to total HRV (CL; rho = 0.32; p = 0.0012. In general, HRV parameters derived from the analyses of Poincaré plots and Lomb-Scargle periodograms appear not to be affected by gender, however, most of them increase with age in the 24-h ECG recordings in healthy children.

  18. Can Tongue Acupuncture Enhance Body Acupuncture? First Results from Heart Rate Variability and Clinical Scores in Patients with Depression

    Directory of Open Access Journals (Sweden)

    Xian Shi

    2014-01-01

    Full Text Available Tongue acupuncture (TA is a method which is not used in western medicine and even in China it is applied very rarely in clinical practice. This study aimed at investigating whether additional TA can improve the efficacy of body acupuncture (BA in patients with depression. Twenty patients with a mean age of ± SD of 42.9±11.2 years were randomly divided into two groups (n=10 patients each, one group receiving BA (Zusanli, Sanyinjiao, Neiguan, Shenting, Yintang, and Baihui and the other receiving BA and TA (Liver, Heart, and Brain. The quantitative and qualitative outcome measures were heart rate (HR, heart rate variability (HRV, and different clinical scores. We found that in both groups all scores and HR improved significantly, whereas HRV increased partly significantly. It seems that TA can enhance acute and treatment effects of BA in patients with depression. The investigation of de qi sensation in TA needs further attention.

  19. Several results from numerical investigation of nonlinear waves connected to blood flow in an elastic tube of variable radius

    CERN Document Server

    Dimitrova, Zlatinka I

    2015-01-01

    We investigate flow of incompressible fluid in a cylindrical tube with elastic walls. The radius of the tube may change along its length. The discussed problem is connected to the blood flow in large human arteries and especially to nonlinear wave propagation due to the pulsations of the heart. The long-wave approximation for modeling of waves in blood is applied. The obtained model Korteweg-deVries equation possessing a variable coefficient is reduced to a nonlinear dynamical system of 3 first order differential equations. The low probability of arising of a solitary wave is shown. Periodic wave solutions of the model system of equations are studied and it is shown that the waves that are consequence of the irregular heart pulsations may be modeled by a sequence of parts of such periodic wave solutions.

  20. Conditional acceptability of random variables

    Directory of Open Access Journals (Sweden)

    Tasos C Christofides

    2016-06-01

    Full Text Available Abstract Acceptable random variables introduced by Giuliano Antonini et al. (J. Math. Anal. Appl. 338:1188-1203, 2008 form a class of dependent random variables that contains negatively dependent random variables as a particular case. The concept of acceptability has been studied by authors under various versions of the definition, such as extended acceptability or wide acceptability. In this paper, we combine the concept of acceptability with the concept of conditioning, which has been the subject of current research activity. For conditionally acceptable random variables, we provide a number of probability inequalities that can be used to obtain asymptotic results.

  1. The GALEX Time Domain Survey. II. Wavelength-Dependent Variability of Active Galactic Nuclei in the Pan-STARRS1 Medium Deep Survey

    CERN Document Server

    Hung, T; Jones, D O; Kirshner, R P; Chornock, R; Berger, E; Rest, A; Huber, M; Narayan, G; Scolnic, D; Waters, C; Wainscoat, R; Martin, D C; Forster, K; Neill, J D

    2016-01-01

    We analyze the wavelength-dependent variability of a sample of spectroscopically confirmed active galactic nuclei (AGN) selected from near-UV ($NUV$) variable sources in the GALEX Time Domain Survey that have a large amplitude of optical variability (difference-flux S/N $>$ 3) in the Pan-STARRS1 Medium Deep Survey (PS1 MDS). By matching GALEX and PS1 epochs in 5 bands ($NUV$, $g_{P1}$, $r_{P1}$, $i_{P1}$, $z_{P1}$) in time, and taking their flux difference, we create co-temporal difference-flux spectral energy distributions ($\\Delta f$SEDs) using two chosen epochs for each of the 23 objects in our sample on timescales of about a year. We confirm the "bluer-when-brighter" trend reported in previous studies, and measure a median spectral index of the $\\Delta f$SEDs of $\\alpha_{\\lambda}$ = 2.1 that is consistent with an accretion disk spectrum. We further fit the $\\Delta f$SEDs of each source with a standard accretion disk model in which the accretion rate changes from one epoch to the other. In our sample, 17 o...

  2. Results of the application of the American Diabetes Association guidelines regarding tobacco dependency in subjects with diabetes mellitus.

    Science.gov (United States)

    Albareda, Mercè; Sánchez, Lucinda; González, Joana; Viguera, Jaume; Mestrón, Antonio; Vernet, Angels; Vila, Lluís

    2009-09-01

    The objective of the study was to evaluate the stages of change for cessation in smoking after the application of American Diabetes Association recommendations in diabetic patients who smoke. This longitudinal descriptive study involved smokers with diabetes mellitus (DM) who were attended for their DM between September 2003 and December 2006. Intervention used was dependent on the stage of change for cessation (according to Prochaska and Di Clemente). For precontemplation subjects, a brief session was carried out where information regarding the risks of smoking in conjunction with DM was given. Patients at the contemplation stage of smoking cessation were offered the chance to participate in a cessation program. Later evaluation was carried out after a follow-up of more than 6 months. Seven hundred thirty-three subjects with DM were evaluated, including 156 smokers (21.28%): 103 (66.02%) in the precontemplation stage, 25 (16.02%) in the contemplation stage, 12 (7.69%) in the preparation stage, 12 (7.69%) in the action stage, and 4 (2.56%) in the maintenance stage. By the last follow-up, 65 (41.6%) subjects had quit smoking (36 ex-smokers), of whom 20 (30.77%) had subsequently relapsed. The use of the American Diabetes Association recommendations for the treatment of tobacco dependence in diabetes treatment results in an increased change of smoking cessation stages in subjects with DM as well as a higher overall percentage in abstinence.

  3. Interobserver variability in gross tumor volume delineation for hepatocellular carcinoma. Results of Korean Radiation Oncology Group 1207 study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Suk [Jeju National University School of Medicine, Department of Radiation Oncology, Jeju National University Hospital, Jeju (Korea, Republic of); Kim, Jun Won; Lee, Ik Jae [Yonsei University College of Medicine, Department of Radiation Oncology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Yoon, Won Sup [Korea University Medical Center, Department of Radiation Oncology, Ansan Hospital, Ansan (Korea, Republic of); Kang, Min Kyu [Kyungpook National University School of Medicine, Department of Radiation Oncology, Daegu (Korea, Republic of); Kim, Tae Hyun [National Cancer Center, Center for Liver Cancer, Goyang (Korea, Republic of); Kim, Jin Hee [Keimyung University School of Medicine, Department of Radiation Oncology, Dongsan Medical Center, Daegu (Korea, Republic of); Lee, Hyung-Sik [Dong-A University College of Medicine, Department of Radiation Oncology, Busan (Korea, Republic of); Park, Hee Chul [Sungkyunkwan University School of Medicine, Department of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of); Jang, Hong Seok; Kay, Chul Seung [The Catholic University of Korea College of Medicine, Department of Radiation Oncology, Seoul (Korea, Republic of); Yoon, Sang Min [University of Ulsan College of Medicine, Department of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of); Kim, Mi-Sook [Korea Institute of Radiological and Medical Sciences, Department of Radiation Oncology, Seoul (Korea, Republic of); Seong, Jinsil [Yonsei University College of Medicine, Department of Radiation Oncology, Severance Hospital, Seodaemun-gu, Seoul (Korea, Republic of)

    2016-10-15

    There has been increasing use of external beam radiotherapy for localized treatment of hepatocellular carcinoma (HCC) with both palliative and curative intent. Quality control of target delineation in primary HCC is essential to deliver adequate doses of radiation to the primary tumor while preserving adjacent healthy organs. We analyzed interobserver variability in gross tumor volume (GTV) delineation for HCC. Twelve radiation oncologists specializing in liver malignancy participated in a multi-institutional contouring dummy-run study of nine HCC cases and independently delineated GTV on the same set of provided computed tomography images. Quantitative analysis was performed using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE) with kappa statistics calculating agreement between physicians. To quantify the interobserver variability of GTV delineations, the ratio of the actual delineated volume to the estimated consensus volume (STAPLE), the ratio of the common and encompassing volumes, and the coefficient of variation were calculated. The median kappa agreement level was 0.71 (range 0.28-0.86). The ratio of the actual delineated volume to the estimated consensus volume ranged from 0.19 to 1.93 (median 0.94) for all cases. The ratio of the common and encompassing volumes ranged from 0.001 to 0.56 (median 0.25). The coefficient of variation for GTV delineation ranged from 8 to 57 % (median 26 %). The interobserver variability in target delineation of HCC GTV in this study is noteworthy. Multi-institution studies involving radiotherapy for HCC require appropriate quality assurance programs for target delineation. (orig.) [German] Die externe kurative Strahlentherapie ist zunehmend bei der lokalisierten Behandlung hepatozellulaerer Karzinome (HCC) in palliativer und kurativer Absicht in Gebrauch. Eine Qualitaetskontrolle der Zielabgrenzung beim primaeren HCC ist entscheidend, um die passende Dosis fuer die

  4. Breeder and batch-dependent variability in the acquisition and performance of a motor skill in adult Long-Evans rats.

    Science.gov (United States)

    O'Bryant, Amber J; Allred, Rachel P; Maldonado, Monica A; Cormack, Lawrence K; Jones, Theresa A

    2011-10-10

    Reaching tasks are popular tools for investigating the neural mechanisms of motor skill learning and recovery from brain damage in rodents, but there is considerable unexplained variability across studies using these tasks. We investigated whether breeder, batch effects, experimenter, time of year, weight and other factors contribute to differences in the acquisition and performance of a skilled reaching task, the single pellet retrieval task, in adult male Long-Evans hooded rats. First, we retrospectively analyzed task acquisition and performance in rats from different breeding colonies that were used in several studies spanning a 3 year period in our laboratory. Second, we compared reaching variables in age-matched rats from different breeders that were trained together as a batch by the same experimenters. All rats had received daily training on the reaching task until they reached a criterion of successful reaches per attempt. We found significant breeder-dependent differences in learning rate and final performance level. This was found even when age-matched rats from different breeders were trained together by the same experimenters. There was also significant batch-to-batch variability within rats from the same breeder trained by the same experimenter. Other factors, including weight, paw preference and the experimenter, were not as strong or consistent in their contributions to differences across studies. The breeder and batch effects found within the same rat strain may reflect genetic and environmental influences on the neural substrates of motor skill learning. This is an important consideration when comparing baseline performance across studies and for controlling variability within studies.

  5. [Genetic history of Aleuts of the Komandor islands from results of analyzing variability of class II HLA genes].

    Science.gov (United States)

    Volod'ko, N V; Derbeneva, O A; Uinuk-ool, T S; Sukernik, R I

    2003-12-01

    Variability of the HLA class II genes (alleles of the DRB1, DQA1, and DQB1 loci) was investigated in a sample of Aleuts of the Commanders (n = 31), whose ancestors inhabited the Commander Islands for many thousand years. Among 19 haplotypes revealed in Aleuts of the Commanders, at most eight were inherited from the native inhabitants of the Commander Islands. Five of these haplotypes (DRB1*0401-DQA1*0301-DQB1*0301, DRB1*1401-DQA1*0101-DQB1*0503, DRB1*0802-DQA1*0401-DQB1*0402, DRB1*1101-DQA1*0501-DQB1*0301, and DRB1*1201-DQA1*0501-DQB1*0301) were typical of Beringian Mongoloids, i.e., Coastal Chukchi and Koryaks, as well as Siberian and Alaskan Eskimos. Genetic contribution of the immigrants to the genetic pool of proper Aleuts constituted about 52%. Phylogenetic analysis based on Transberingian distribution of the DRB1 allele frequencies favored the hypothesis on the common origin of Paleo-Aleuts, Paleo-Eskimos, and the Indians from the northwestern North America, whose direct ancestors survived in Beringian/southwestern Alaskan coastal refugia during the late Ice Age.

  6. Complete Convergence for Weighted Sums of WOD Random Variables

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying; ZHANG Yu; SHEN Ai-ting

    2016-01-01

    In this article, we study the complete convergence for weighted sums of widely orthant dependent random variables. By using the exponential probability inequality, we establish a complete convergence result for weighted sums of widely orthant dependent ran-dom variables under mild conditions of weights and moments. The result obtained in the paper generalizes the corresponding ones for independent random variables and negatively dependent random variables.

  7. Standardization of Operator-Dependent Variables Affecting Precision and Accuracy of the Disk Diffusion Method for Antibiotic Susceptibility Testing.

    Science.gov (United States)

    Hombach, Michael; Maurer, Florian P; Pfiffner, Tamara; Böttger, Erik C; Furrer, Reinhard

    2015-12-01

    Parameters like zone reading, inoculum density, and plate streaking influence the precision and accuracy of disk diffusion antibiotic susceptibility testing (AST). While improved reading precision has been demonstrated using automated imaging systems, standardization of the inoculum and of plate streaking have not been systematically investigated yet. This study analyzed whether photometrically controlled inoculum preparation and/or automated inoculation could further improve the standardization of disk diffusion. Suspensions of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 29213 of 0.5 McFarland standard were prepared by 10 operators using both visual comparison to turbidity standards and a Densichek photometer (bioMérieux), and the resulting CFU counts were determined. Furthermore, eight experienced operators each inoculated 10 Mueller-Hinton agar plates using a single 0.5 McFarland standard bacterial suspension of E. coli ATCC 25922 using regular cotton swabs, dry flocked swabs (Copan, Brescia, Italy), or an automated streaking device (BD-Kiestra, Drachten, Netherlands). The mean CFU counts obtained from 0.5 McFarland standard E. coli ATCC 25922 suspensions were significantly different for suspensions prepared by eye and by Densichek (P counts that were closer to the CLSI/EUCAST target of 10(8) CFU/ml than those resulting from Densichek preparation. No significant differences in the standard deviations of the CFU counts were observed. The interoperator differences in standard deviations when dry flocked swabs were used decreased significantly compared to the differences when regular cotton swabs were used, whereas the mean of the standard deviations of all operators together was not significantly altered. In contrast, automated streaking significantly reduced both interoperator differences, i.e., the individual standard deviations, compared to the standard deviations for the manual method, and the mean of the standard deviations of all operators

  8. Variability in the treatment of acute spinal cord injury in the United Kingdom: results of a national survey.

    Science.gov (United States)

    Werndle, Melissa C; Zoumprouli, Argyro; Sedgwick, Philip; Papadopoulos, Marios C

    2012-03-20

    The aim of this study was to examine how traumatic spinal cord injury is managed in the United Kingdom via a questionnaire survey of all neurosurgical units. We contacted consultant neurosurgeons and neuroanesthetists in all neurosurgical centers that manage patients with acute spinal cord injury. Two clinical scenarios-of complete and incomplete cervical spinal cord injuries-were given to determine local treatment policies. There were 175 responders from the 33 centers (36% response rate). We ascertained neurosurgical views on urgency of transfer, timing of surgery, nature and aim of surgery, as well as neuroanesthetic views on type of anesthetic, essential intraoperative monitoring, drug treatment, and intensive care management. Approximately 70% of neurosurgeons will admit patients with incomplete spinal cord injury immediately, but only 40% will admit patients with complete spinal cord injury immediately. There is no consensus on the timing or even the role of surgery for incomplete or complete injuries. Most (96%) neuroanesthetists avoid anesthetics known to elevate intracranial pressure. What was deemed essential intraoperative monitoring, however, varied widely. Many (22%) neuroanesthetists do not routinely measure arterial blood pressure invasively, central venous pressure (85%), or cardiac output (94%) during surgery. There is no consensus among neuroanesthetists on the optimal levels of arterial blood pressure, or oxygen and carbon dioxide partial arterial pressure. We report wide variability among U.K. neurosurgeons and neuroanesthetists in their treatment of acute traumatic spinal cord injury. Our findings reflect the lack of Class 1 evidence that early surgical decompression and intensive medical management of patients with spinal cord injury improves neurological outcome.

  9. Effects of daily hemodialysis on heart rate variability: results from the Frequent Hemodialysis Network (FHN) Daily Trial.

    Science.gov (United States)

    Chan, Christopher T; Chertow, Glenn M; Daugirdas, John T; Greene, Tom H; Kotanko, Peter; Larive, Brett; Pierratos, Andreas; Stokes, John B

    2014-01-01

    End-stage renal disease is associated with reduced heart rate variability (HRV), components of which generally are associated with advanced age, diabetes mellitus and left ventricular hypertrophy. We hypothesized that daily in-center hemodialysis (HD) would increase HRV. The Frequent Hemodialysis Network (FHN) Daily Trial randomized 245 patients to receive 12 months of six versus three times per week in-center HD. Two hundred and seven patients had baseline Holter recordings. HRV measures were calculated from 24-h Holter electrocardiograms at both baseline and 12 months in 131 patients and included low-frequency power (LF, a measure of sympathetic modulation), high-frequency power (HF, a measure of parasympathetic modulation) and standard deviation (SD) of the R-R interval (SDNN, a measure of beat-to-beat variation). Baseline to Month 12 change in LF was augmented by 50% [95% confidence interval (95% CI) 6.1-112%, P =0.022] and LF + HF was augmented by 40% (95% CI 3.3-88.4%, P = 0.03) in patients assigned to daily hemodialysis (DHD) compared with conventional HD. Changes in HF and SDNN were similar between the randomized groups. The effects of DHD on LF were attenuated by advanced age and diabetes mellitus (predefined subgroups). Changes in HF (r = -0.20, P = 0.02) and SDNN (r = -0.18, P = 0.04) were inversely associated with changes in left ventricular mass (LVM). DHD increased the LF component of HRV. Reduction of LVM by DHD was associated with increased vagal modulation of heart rate (HF) and with increased beat-to-beat heart rate variation (SDNN), suggesting an important functional correlate to the structural effects of DHD on the heart in uremia.

  10. Galactic model parameters of cataclysmic variables: Results from a new absolute magnitude calibration with 2MASS and WISE

    Science.gov (United States)

    Özdönmez, A.; Ak, T.; Bilir, S.

    2015-01-01

    In order to determine the spatial distribution, Galactic model parameters and luminosity function of cataclysmic variables (CVs), a J-band magnitude limited sample of 263 CVs has been established using a newly constructed period-luminosity-colours (PLCs) relation which includes J,Ks and W1-band magnitudes in 2MASS and WISE photometries, and the orbital periods of the systems. This CV sample is assumed to be homogeneous regarding to distances as the new PLCs relation is calibrated with new or re-measured trigonometric parallaxes. Our analysis shows that the scaleheight of CVs is increasing towards shorter periods, although selection effects for the periods shorter than 2.25 h dramatically decrease the scaleheight: the scaleheight of the systems increases from 192 pc to 326 pc as the orbital period decreases from 12 to 2.25 h. The z-distribution of all CVs in the sample is well fitted by an exponential function with a scaleheight of 213-10+11 pc. However, we suggest that the scaleheight of CVs in the Solar vicinity should be ∼300 pc and that the scaleheights derived using the sech2 function should be also considered in the population synthesis models. The space density of CVs in the Solar vicinity is found 5.58(1.35)×10-6 pc-3 which is in the range of previously derived space densities and not in agreement with the predictions of the population models. The analysis based on the comparisons of the luminosity function of white dwarfs with the luminosity function of CVs in this study show that the best fits are obtained by dividing the luminosity functions of white dwarfs by a factor of 350-450.

  11. Final COMPASS results on the deuteron spin-dependent structure function g1d and the Bjorken sum rule

    Directory of Open Access Journals (Sweden)

    C. Adolph

    2017-06-01

    Full Text Available Final results are presented from the inclusive measurement of deep-inelastic polarised-muon scattering on longitudinally polarised deuterons using a 6LiD target. The data were taken at 160 GeV beam energy and the results are shown for the kinematic range 1(GeV/c24GeV/c2 in the mass of the hadronic final state. The deuteron double-spin asymmetry A1d and the deuteron longitudinal-spin structure function g1d are presented in bins of x and Q2. Towards lowest accessible values of x, g1d decreases and becomes consistent with zero within uncertainties. The presented final g1d values together with the recently published final g1p values of COMPASS are used to again evaluate the Bjorken sum rule and perform the QCD fit to the g1 world data at next-to-leading order of the strong coupling constant. In both cases, changes in central values of the resulting numbers are well within statistical uncertainties. The flavour-singlet axial charge a0, which is identified in the MS‾ renormalisation scheme with the total contribution of quark helicities to the nucleon spin, is extracted at next-to-leading order accuracy from only the COMPASS deuteron data: a0(Q2=3(GeV/c2=0.32±0.02stat±0.04syst±0.05evol. Together with the recent results on the proton spin structure function g1p, the results on g1d constitute the COMPASS legacy on the measurements of g1 through inclusive spin-dependent deep inelastic scattering.

  12. Variable Stars in the Large Magellanic Cloud Globular Cluster NGC 2257. I. Results Based on 2007-2008 B, V Photometry

    Science.gov (United States)

    Nemec, James M.; Walker, Alistair; Jeon, Young-Beom

    2009-11-01

    The variable stars in the Large Magellanic Cloud star cluster NGC 2257 are reinvestigated using photometry (to ~20th mag) of over 400 new B, V CCD images taken with the CTIO 0.9 m telescope on 14 nights in 2007 December and 2008 January. New period searches have been made using two independent algorithms (CLEAN, Period04); the resultant periods of most of the stars are consistent with the pulsation periods derived previously, and where there are discrepancies these have been resolved. For the B and V light curves, accurate Fourier coefficients and parameters are given. Six new variable stars have been discovered (V45-50), including a bright candidate long-period variable star showing secondary oscillations (V45) and two anomalously bright RRc stars (V48 and V50), which are shown to be brightened and reddened by nearby red giant stars. Also discovered among the previously known variable stars are three double-mode RR Lyrae stars (V8, V16, and V34) and several Blazhko variables. Archival Hubble Space Telescope images and the photometry by Johnson et al. have been used to define better the properties of the most crowded variable stars. The total number of cluster variable stars now stands at forty-seven: 23 RRab stars, four of which show Blazhko amplitude variations; 20 RRc stars, one showing clear Blazhko variations and another showing possible Blazhko variations; the three RRd stars, all having the dominant period ~0.36 day and period ratios P 1/P 0 ~0.7450; and an LPV star located near the tip of the red giant branch. A comparison of the RRd stars with those in other environments shows them to be most similar to those in IC4499.

  13. Disability, caregiver's dependency and patterns of access to rehabilitation care: results from a national representative study in Peru.

    Science.gov (United States)

    Bernabe-Ortiz, Antonio; Diez-Canseco, Francisco; Vásquez, Alberto; Miranda, J Jaime

    2016-01-01

    To determine the prevalence of disability in Peru, explore dependency on caregiver's assistance and assess access to rehabilitation care. Data from Disability National Survey (ENEDIS), including urban and rural areas, were analyzed. Disability was defined as a permanent limitation on movement, vision, communication, hearing, learning/remembering or social relationships. Dependency was defined as the self-reported need for a caregiver to help with daily activities; and access to rehabilitation care was defined as the self-report of any therapy for disabilities. Estimates and projections were calculated using sample strata, primary sampling units and population weights, and prevalence ratios (PRs) and 95%CI were reported. From 798,308 people screened, 37,524 (5.1%; 95%CI 4.9--5.2%) had at least one disability. A total of 37,117 were included in further analysis, mean age 57.8 (SD ± 24.1) years, 52.1% women. Dependency was self-reported by 14,980 (40.5%; 95%CI: 39.2-41.9%) individuals with disabilities. A family member, usually female, was identified as a caregiver in 94.3% (95%CI: 93.3-95.3%) of dependent participants. Only 2881 (10.7%; 95%CI: 9.7-11.9%) of people with disabilities reported access to rehabilitation care. Major inequality patterns of disability burden versus access to rehabilitation care were observed by age and education level. Older age groups had higher disability burden yet lower chances of access to rehabilitation care. Conversely, the higher the education level, the lesser the overall disability burden but also the higher chances of reporting receiving care. Private healthcare insurance doubled the probability of having access to rehabilitation compared with those without insurance. Approximately 1.6 million Peruvians have at least one disability, and 40% of them require assistance with daily activities. Informal caregiving, likely female and relative-provided, is highly common. Rehabilitation care access is low and inequitable. Our results

  14. Influence of clinical and laboratory variables on faecal antigen ELISA results in dogs with canine parvovirus infection.

    Science.gov (United States)

    Proksch, A L; Unterer, S; Speck, S; Truyen, U; Hartmann, K

    2015-06-01

    False negative faecal canine parvovirus (CPV) antigen ELISA results in dogs with CPV infection are common, but the factors that lead to these false negative results are still unknown. The aim of this study was to investigate whether dogs with a false negative faecal CPV antigen ELISA result have milder clinical signs and laboratory changes, a lower faecal virus load, higher faecal and serum CPV antibody titres and a faster recovery than dogs with a positive result. Eighty dogs with CPV infection, confirmed by the presence of clinical signs and a positive faecal CPV polymerase chain reaction (PCR), were assigned to two groups according to their faecal antigen ELISA result. Time until presentation, severity of symptoms, laboratory parameters, faecal virus load, faecal and serum antibody titres, and CPV sequencing data were compared between both groups. In 38/80 dogs that were hospitalised until recovery, the time to recovery, mortality, and the course of the disease were compared between dogs with positive and negative faecal antigen ELISA results. Of the 80 dogs included, 41 (51.3%) had a false negative faecal antigen ELISA result. ELISA-negative dogs had a significantly shorter time until presentation, lower frequency of defaecation, lower faecal virus load, and higher serum antibody concentrations than ELISA-positive dogs. Laboratory changes, CPV shedding, and outcomes were not associated with faecal antigen ELISA results. In conclusion, low faecal CPV load and antibodies binding to CPV antigen in faeces are likely to be important reasons for false negative faecal antigen ELISA results. Dogs with clinical signs of CPV infection should be retested by faecal PCR.

  15. Variability in wave refraction and resultant nearshore current patterns: Exposed versus sheltered beaches along north Karnataka, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Veerayya, M.; Pankajakshan, T.

    For predominant waves approaching from directions varying between SW and WNW and periods varying from 6 to 11 sec, the refraction function (Kd) shows amplification of wave heights resulting in concentration of wave energy on headlands and reduction...

  16. Simvastatin Results in a Dose-Dependent Toxic Effect on Spiral Ganglion Neurons in an In Vitro Organotypic Culture Assay

    Directory of Open Access Journals (Sweden)

    Katharina Leitmeyer

    2016-01-01

    Full Text Available Statins are inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase, an enzyme necessary for the production of mevalonate. They are widely used as cholesterol-lowering drugs. However, conflicting data about the effect of statins on neuronal cells has been published. To explore the effect of simvastatin on spiral ganglion neurons (SGNs, SG explants of 5-day-old rats were treated with increasing concentrations of simvastatin. In addition, SG explants were treated with mevalonate and with the combination of simvastatin and mevalonate. SGN number, length of the neurites, area of nonneuronal supporting cells, and neuronal survival were analyzed. Simvastatin treatment results in a significant dose-dependent decrease of SG neurite number, length of neurites, area of supporting cells, and SG neuronal survival compared to control. Interestingly, treatment with mevalonate in addition to simvastatin increased SG neuronal survival compared to simvastatin treatment only. However, treatment with mevalonate in addition to simvastatin did not influence SG neurite number, length of neurites, and area of supporting cells compared to simvastatin treatment only. Our results suggest a neurotoxic effect of simvastatin on SGNs in vitro. Neurotoxicity seems to be at least partially mediated by the mevalonate pathway. Therefore, caution is warranted to use simvastatin as a potential otoprotective drug.

  17. Cortical axons, isolated in channels, display activity-dependent signal modulation as a result of targeted stimulation

    Directory of Open Access Journals (Sweden)

    Marta K. Lewandowska

    2016-03-01

    Full Text Available Mammalian cortical axons are extremely thin processes that are difficult to study as a result of their small diameter: they are too narrow to patch while intact, and super-resolution microscopy is needed to resolve single axons. We present a method for studying axonal physiology by pairing a high-density microelectrode array with a microfluidic axonal isolation device, and use it to study activity-dependent modulation of axonal signal propagation evoked by stimulation near the soma. Up to three axonal branches from a single neuron, isolated in different channels, were recorded from simultaneously using 10-20 electrodes per channel. The axonal channels amplified spikes such that propagations of individual signals along tens of electrodes could easily be discerned with high signal to noise. Stimulation from 10 Hz up to 160 Hz demonstrated similar qualitative results from all of the cells studied: extracellular action potential characteristics changed drastically in response to stimulation. Spike height decreased, spike width increased, and latency increased, as a result of reduced propagation velocity, as the number of stimulations and the stimulation frequencies increased. Quantitatively, the strength of these changes manifested itself differently in cells at different frequencies of stimulation. Some cells’ signal fidelity fell to 80% already at 10 Hz, while others maintained 80% signal fidelity at 80 Hz. Differences in modulation by axonal branches of the same cell were also seen for many different stimulation frequencies, starting at 10 Hz. Potassium ion concentration changes altered the behavior of the cells causing propagation failures at lower concentrations and improving signal fidelity at higher concentrations.

  18. Intra- and inter-individual variability of Aspergillus fumigatus reactive T-cell frequencies in healthy volunteers in dependency of mould exposure in residential and working environment.

    Science.gov (United States)

    Wurster, Sebastian; Weis, Philipp; Page, Lukas; Helm, Johanna; Lazariotou, Maria; Einsele, Hermann; Ullmann, Andrew J

    2017-10-01

    Invasive aspergillosis remains a deadly disease in immunocompromised patients, whereas the combination of an exaggerated immune response and continuous exposure lead to various hyperinflammatory diseases. This pilot study aimed to gain an overview of the intra- and inter-individual variability in Aspergillus fumigatus reactive T-helper cells in healthy adults and the correlation with environmental mould exposure. In this flow cytometric study, the frequencies of CD154(+) A. fumigatus reactive T cells were evaluated in 70 healthy volunteers. All subjects completed a standardised questionnaire addressing their mould exposure. Subjects with intensive mould exposure in their professional or residential surrounding demonstrated considerably higher mean frequencies of A. fumigatus reactive T-helper and T-memory cells. Comparative evaluation of multiple measurements over time demonstrated relatively conserved reactive T-cell frequencies in the absence of major changes to the exposure profile, whereas those frequently exposed in professional environment or with changes to their risk score demonstrated a marked dependency of antigen reactive T-cell frequencies on recent mould exposure. This pilot study was the first to provide data on the intra-individual variability in A. fumigatus reactive T-cell frequencies and its linkage to mould encounter. Fungus reactive T cells are to be considered a valued tool for the assessment of environmental mould exposure. © 2017 Blackwell Verlag GmbH.

  19. Experiment Description and Results for Arrival Operations Using Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR)

    Science.gov (United States)

    Baxley, Brian T.; Murdoch, Jennifer L.; Swieringa, Kurt A.; Barmore, Bryan E.; Capron, William R.; Hubbs, Clay E.; Shay, Richard F.; Abbott, Terence S.

    2013-01-01

    The predicted increase in the number of commercial aircraft operations creates a need for improved operational efficiency. Two areas believed to offer increases in aircraft efficiency are optimized profile descents and dependent parallel runway operations. Using Flight deck Interval Management (FIM) software and procedures during these operations, flight crews can achieve by the runway threshold an interval assigned by air traffic control (ATC) behind the preceding aircraft that maximizes runway throughput while minimizing additional fuel consumption and pilot workload. This document describes an experiment where 24 pilots flew arrivals into the Dallas Fort-Worth terminal environment using one of three simulators at NASA?s Langley Research Center. Results indicate that pilots delivered their aircraft to the runway threshold within +/- 3.5 seconds of their assigned time interval, and reported low workload levels. In general, pilots found the FIM concept, procedures, speeds, and interface acceptable. Analysis of the time error and FIM speed changes as a function of arrival stream position suggest the spacing algorithm generates stable behavior while in the presence of continuous (wind) or impulse (offset) error. Concerns reported included multiple speed changes within a short time period, and an airspeed increase followed shortly by an airspeed decrease.

  20. Deficiency of the cyclin-dependent kinase inhibitor, CDKN1B, results in overgrowth and neurodevelopmental delay.

    Science.gov (United States)

    Grey, William; Izatt, Louise; Sahraoui, Wafa; Ng, Yiu-Ming; Ogilvie, Caroline; Hulse, Anthony; Tse, Eric; Holic, Roman; Yu, Veronica

    2013-06-01

    Germline mutations in the cyclin-dependent kinase inhibitor, CDKN1B, have been described in patients with multiple endocrine neoplasia (MEN), a cancer predisposition syndrome with adult onset neoplasia and no additional phenotypes. Here, we describe the first human case of CDKN1B deficiency, which recapitulates features of the murine CDKN1B knockout mouse model, including gigantism and neurodevelopmental defects. Decreased mRNA and protein expression of CDKN1B were confirmed in the proband's peripheral blood, which is not seen in MEN syndrome patients. We ascribed the decreased protein level to a maternally derived deletion on chromosome 12p13 encompassing the CDKN1B locus (which reduced mRNA expression) and a de novo allelic variant (c.-73G>A) in the CDKN1B promoter (which reduced protein translation). We propose a recessive model where decreased dosage of CDKN1B during development in humans results in a neuronal phenotype akin to that described in mice, placing CDKN1B as a candidate gene involved in developmental delay.

  1. Low-frequency ac electroporation shows strong frequency dependence and yields comparable transfection results to dc electroporation.

    Science.gov (United States)

    Zhan, Yihong; Cao, Zhenning; Bao, Ning; Li, Jianbo; Wang, Jun; Geng, Tao; Lin, Hao; Lu, Chang

    2012-06-28

    Conventional electroporation has been conducted by employing short direct current (dc) pulses for delivery of macromolecules such as DNA into cells. The use of alternating current (ac) field for electroporation has mostly been explored in the frequency range of 10kHz-1MHz. Based on Schwan equation, it was thought that with low ac frequencies (10Hz-10kHz), the transmembrane potential does not vary with the frequency. In this report, we utilized a flow-through electroporation technique that employed continuous 10Hz-10kHz ac field (based on either sine waves or square waves) for electroporation of cells with defined duration and intensity. Our results reveal that electropermeabilization becomes weaker with increased frequency in this range. In contrast, transfection efficiency with DNA reaches its maximum at medium frequencies (100-1000Hz) in the range. We postulate that the relationship between the transfection efficiency and the ac frequency is determined by combined effects from electrophoretic movement of DNA in the ac field, dependence of the DNA/membrane interaction on the ac frequency, and variation of transfection under different electropermeabilization intensities. The fact that ac electroporation in this frequency range yields high efficiency for transfection (up to ~71% for Chinese hamster ovary cells) and permeabilization suggests its potential for gene delivery.

  2. CHRM2 gene predisposes to alcohol dependence, drug dependence and affective disorders: results from an extended case-control structured association study.

    Science.gov (United States)

    Luo, Xingguang; Kranzler, Henry R; Zuo, Lingjun; Wang, Shuang; Blumberg, Hilary P; Gelernter, Joel

    2005-08-15

    Cholinergic muscarinic 2 receptor (CHRM2) is implicated in memory and cognition, functions impaired in many neuropsychiatric disorders. Wang et al. [Wang, J.C., Hinrichs, A.L., Stock, H., Budde, J., Allen, R., Bertelsen, S., Kwon, J.M., Wu, W., Dick, D.M., Rice, J. et al. (2004) Evidence of common and specific genetic effects: association of the muscarinic acetylcholine receptor M2 (CHRM2) gene with alcohol dependence and major depressive syndrome. Hum. Mol. Genet., 13, 1903-1911] reported that variation in CHRM2 gene predisposed to alcohol dependence (AD) and major depressive syndrome. We examined the relationships between variation in CHRM2 and AD, drug dependence (DD) and affective disorders, using a novel extended case-control structured association (SA) method. Six markers at CHRM2 and 38 ancestry-informative markers (AIMs) were genotyped in a sample of 871 subjects, including 333 healthy controls [287 European-Americans (EAs) and 46 African-Americans (AAs)] and 538 AD and/or DD subjects (415 with AD and 346 with DD and 382 EAs and 156 AAs). The same CHRM2 markers were genotyped in a sample of 137 EA subjects with affective disorders. All of the six markers were in Hardy-Weinberg equilibrium in controls, but SNP3 (rs1824024) was in Hardy-Weinberg disequilibrium in the AD and DD groups. Using conventional case-control comparisons, some markers were nominally significantly or suggestively associated with phenotypes before or after controlling for population stratification and admixture effects, but these associations were not significant after multiple test correction. However, regression analysis identified specific alleles, genotypes, haplotypes and diplotypes that were significantly associated with risk for each disorder. We conclude that variation in CHRM2 predisposes to AD, DD and affective disorders. One haplotype block within the 5'-UTR of CHRM2 may be more important for the development of these disorders than other regions. Interaction between two

  3. A study of gender, head circumference and BMI as a variable affecting BAEP results of late teenagers

    Directory of Open Access Journals (Sweden)

    Jayesh D Solanki

    2012-01-01

    Full Text Available Background : Influence of sex on brainstem auditory evoked potential (BAEP is not well understood with few studies in India that targets young Teenagers. Aim : Our study aimed to look into gender, head circumference, and body mass index (BMI as a factor affecting BAEPs of healthy late teenagers. Materials and Methods : BAEP responses were elicited in age-matched teenager college students using standard protocol. Results of absolute latencies and interpeak latencies (IPLs were compared among Male and female groups and compared for significance as such and after normalizing head size and BMI and tested for significant difference, if any. Results: Latencies and IPLs of BAEP were lower in males when compared with females, but significance was found only for the later parameter. IPLs showing significant gender difference were for I-III and III-V but not I-V. When test groups with comparable head size and BMI were compared, the difference decreased with neither of the parameter being statistically significant. Conclusion: Utility of BAEP can be optimized by establishing normative data for every setup based on BMI and head circumference along with age and gender before using it as a clinical tool.

  4. Correction factors for determination of annual average radon concentration in dwellings of Poland resulting from seasonal variability of indoor radon

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, K., E-mail: Krzysztof.Kozak@ifj.edu.pl [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Mazur, J. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); KozLowska, B. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Karpinska, M. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); Przylibski, T.A. [WrocLaw University of Technology, Wybrzeze S. Wyspianskiego 27, 50-370 WrocLaw (Poland); Mamont-Ciesla, K. [Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warszawa (Poland); Grzadziel, D. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Stawarz, O. [Central Laboratory for Radiological Protection, Konwaliowa 7, 03-194 Warszawa (Poland); Wysocka, M. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland); Dorda, J. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Zebrowski, A. [WrocLaw University of Technology, Wybrzeze S. Wyspianskiego 27, 50-370 WrocLaw (Poland); Olszewski, J. [Nofer Institute of Occupational Medicine, Sw.Teresy od Dzieciatka Jezus 8, 91-348 lodz (Poland); Hovhannisyan, H. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Krakow (Poland); Dohojda, M. [Institute of Building Technology (ITB), Filtrowa 1, 00-611 Warszawa (Poland); KapaLa, J. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); Chmielewska, I. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland); KLos, B. [University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Jankowski, J. [Nofer Institute of Occupational Medicine, Sw.Teresy od Dzieciatka Jezus 8, 91-348 lodz (Poland); Mnich, S. [Medical University of Bialystok, Jana Kilinskiego 1, 15-089 BiaLystok (Poland); KoLodziej, R. [Central Mining Institute, Plac Gwarkow1, 40-166 Katowice (Poland)

    2011-10-15

    The method for the calculation of correction factors is presented, which can be used for the assessment of the mean annual radon concentration on the basis of 1-month or 3-month indoor measurements. Annual radon concentration is an essential value for the determination of the annual dose due to radon inhalation. The measurements have been carried out in 132 houses in Poland over a period of one year. The passive method of track detectors with CR-39 foil was applied. Four thermal-precipitation regions in Poland were established and correction factors were calculated for each region, separately for houses with and without basements. - Highlights: > Using radon concentration results in houses we calculated the correction factors. > Factors were calculated for each month, 2 house types in different regions in Poland. > They enable the evaluation of average annual radon concentration in the house. > Annual average radon concentration basing on 1 or 3 months detector exposure.

  5. Characterizing the variability in chemical composition of flowback and produced waters - results from lab and field studies

    Science.gov (United States)

    Vieth-Hillebrand, Andrea; Wilke, Franziska D. H.; Schmid, Franziska E.; Zhu, Yaling; Lipińska, Olga; Konieczyńska, Monika

    2017-04-01

    The huge volumes and unknown composition of flowback and produced waters cause major public concerns about the environmental and social compatibility of hydraulic fracturing and the exploitation of gas from unconventional reservoirs. Flowback and produced waters contain not only residues of fracking additives but also chemical species that are dissolved from the target shales themselves. Shales are a heterogeneous mixture of minerals, organic matter, and formation water and little is actually understood about the fluid-rock interactions occurring during hydraulic fracturing of the shales and their effects on the chemical composition of flowback and produced water. To overcome this knowledge gap, interactions of different shales with different artificial stimulation fluids were studied in lab experiments under ambient and elevated temperature and pressure conditions. These lab experiments showed clearly that fluid-rock interactions change the chemical composition of the initial stimulation fluid and that geochemistry of the fractured shale is relevant for understanding flowback water composition. In addition, flowback water samples were taken after hydraulic fracturing of one horizontal well in Pomeranian region, Poland and investigated for their chemical composition. With this presentation, results from lab and field studies will be presented and compared to decipher possible controls on chemical compositions of flowback and produced water.

  6. Highly variable use of diagnostic methods for sexually transmitted infections-results of a nationwide survey, Germany 2005

    Directory of Open Access Journals (Sweden)

    Hamouda Osamah

    2010-04-01

    Full Text Available Abstract Background Sexual transmitted infections (STIs have increased in Germany and other countries in Europe since the mid-nineties. To obtain a better picture of diagnostic methods used in STI testing institutions in Germany, we performed a nationwide survey amongst STI specialists in order to evaluate the quality of STI reports and provide recommendations to harmonize and possibly improve STI diagnostics in Germany. Methods We asked sentinel physicians and randomly chosen gynaecologists, urologists and dermato-venerologists, about the diagnostic methods used in 2005 to diagnose HIV, chlamydia (CT, gonorrhoea (GO and syphilis (SY in a national cross-sectional survey in order to recognize potential problems and provide recommendations. Results A total of 739/2287 (32% physicians participated. Of all participants, 80% offered tests for HIV, 84% for CT, 83% for GO and 83% for SY. Of all participants who performed HIV testing, 90% requested an antibody test, 3% a rapid test and 1% a nucleic acid amplification test (NAAT. For CT testing, NAAT was used in 33% and rapid tests in 34% of participants. GO resistance testing was performed by 31% of the participants. SY testing was performed in 98% by serology. Conclusions Diagnostic methods for STI vary highly among the participants. Diagnostic guidelines should be reviewed and harmonised to ensure consistent use of the optimal STI diagnostic methods.

  7. Increased bacterial growth efficiency with environmental variability: results from DOC degradation by bacteria in pure culture experiments

    Directory of Open Access Journals (Sweden)

    M. Eichinger

    2010-06-01

    Full Text Available This paper assesses how considering variation in DOC availability and cell maintenance in bacterial models affects Bacterial Growth Efficiency (BGE estimations. For this purpose, we conducted two biodegradation experiments simultaneously. In experiment one, a given amount of substrate was added to the culture at the start of the experiment whilst in experiment two, the same amount of substrate was added, but using periodic pulses over the time course of the experiment. Three bacterial models, with different levels of complexity, (the Monod, Marr-Pirt and the dynamic energy budget – DEB – models, were used and calibrated using the above experiments. BGE has been estimated using the experimental values obtained from discrete samples and from model generated data. Cell maintenance was derived experimentally, from respiration rate measurements. The results showed that the Monod model did not reproduce the experimental data accurately, whereas the Marr-Pirt and DEB models demonstrated a good level of reproducibility, probably because cell maintenance was built into their formula. Whatever estimation method was used, the BGE value was always higher in experiment two (the periodically pulsed substrate as compared to the initially one-pulsed-substrate experiment. Moreover, BGE values estimated without considering cell maintenance (Monod model and empirical formula were always smaller than BGE values obtained from models taking cell maintenance into account. Since BGE is commonly estimated using constant experimental systems and ignore maintenance, we conclude that these typical methods underestimate BGE values. On a larger scale, and for biogeochemical cycles, this would lead to the conclusion that, for a given DOC supply rate and a given DOC consumption rate, these BGE estimation methods overestimate the role of bacterioplankton as CO2 producers.

  8. Increased bacterial growth efficiency with environmental variability: results from DOC degradation by bacteria in pure culture experiments

    Directory of Open Access Journals (Sweden)

    M. Eichinger

    2010-02-01

    Full Text Available This paper assesses how considering variation in DOC availability and cell maintenance in bacterial models affects Bacterial Growth Efficiency (BGE estimations. For this purpose, we conducted two biodegradation experiments simultaneously. In experiment one, a given amount of substrate was added to the culture at the start of the experiment whilst in experiment two, the same amount of substrate was added, but using periodic pulses over the time course of the experiment. Three bacterial models, with different levels of complexity, (the Monod, Marr-Pirt and the dynamic energy budget (DEB model, were used, and calibrated using the above experiments. BGE has been estimated using the experimental values obtained from discrete samples and from model generated data. Cell maintenance was derived experimentally, from respiration rate measurements. The results showed that the Monod model did not reproduce the experimental data accurately, whereas the Marr-Pirt and DEB models demonstrated a good level of reproducibility, probably because cell maintenance was built into their formula. Whatever estimation method was used, the BGE value was always higher in experiment two (the periodically pulsed substrate as compared to the initially one-pulsed-substrate experiment. Moreover, BGE values estimated without considering cell maintenance (Monod model and empirical formula were always smaller than BGE values obtained from models taking cell maintenance into account. Since BGE is commonly estimated using constant experimental systems and ignore maintenance, we conclude that these typical methods underestimate BGE values. On a larger scale, and for biogeochemical cycles, this would lead to the conclusion that, for a given DOC supply rate and a given DOC consumption rate, these BGE estimation methods overestimate the role of bacterioplankton as CO2 producers.

  9. Lateral Variability of the Lower Ocean Crust at Atlantis Bank, SW Indian Ridge, Results of IODP Expedition 360

    Science.gov (United States)

    Dick, H. J.; MacLeod, C. J.; Blum, P.; Scientific Party, E.

    2016-12-01

    emplacement of small gabbro bodies, with upward compaction of late melt, often fault controlled. The primary differences in the sections are due to variations in the melt supply, which was significantly lower at Hole U1309D, resulting in incorporation of mantle peridotite screens into the section as additional gabbro intrusions were added to the base of the section.

  10. Temporal variability of nitrous oxide fluxes from a fertilized grassland in Belgium: preliminary results from dynamic closed chambers.

    Science.gov (United States)

    Beekkerk van Ruth, Joran; Moureaux, Christine; Degré, Aurore; Jérome, Elisabeth; Beckers, Yves; Bodson, Bernard; Aubinet, Marc

    2013-04-01

    This work presents preliminary results of nitrous oxide (N2O) fluxes measured by dynamic closed chambers from a fertilized grassland grazed by the Belgian Blue breed of cattle. It is part of a project funded by the public service of Wallonia (SPW-DGARNE), whose objectives are to make a carbon/CO2 balance of the grassland (Jérôme et al., 2013) and to quantify CH4 (Dumortier et al., 2013) and N2O fluxes. The site is located in Dorinne (Dorinne Terrestrial Observatory), Belgium (50° 18' 44" N; 4° 58' 07" E; 248 m al.). It is a permanent grassland of ca. 4.2 ha with a moderate slope of 1 to 2 %. Mineral fertilisation took place in March and May 2012. Two cylindrical chambers of 19,2 cm diameter and 11,5 cm height were placed inside a protected area around a micrometeorological station. An infrared gas analyser (Thermofischer 46i) was used in order to measure the N2O concentrations inside of the chambers, closed by automatically controlled lids and ventilated by a constant air flow of 1liter/min. These devices were completed by adjacent soil humidity and temperature sensors. The first measurement campaign took place during June and July 2012. The chambers were installed in the field and N2O fluxes were followed without manipulation. N2O fluxes were characterised by a background emission (between 2 and 10 ngN.m2s-1) on which intense but time limited peaks (between 50 and 300 ngN.m2s-1) superimposed. Peaks were found to be mainly linked to fertilisation and driven by precipitation. Background fluxes were found to correlate positively with soil temperature. Secondly, a manipulation experiment took place in November 2012: two different fertilizer treatments were applied to the chambers. Doses of respectively 100 and 200 kg N/ha of ammonium nitrate were sprayed in the chambers (equivalent to a 8 mm precipitation). N2O fluxes peaked shortly after fertiliser application (respectively 300 and 550 ngN.m2s-1), as well as after a posterior rain event (respectively 800 and 1500

  11. Co-occurring amphetamine use and associated medical and psychiatric comorbidity among opioid-dependent adults: results from the Clinical Trials Network

    Directory of Open Access Journals (Sweden)

    Blazer DG

    2011-07-01

    Full Text Available Daniel J Pilowsky1, Li-Tzy Wu2, Bruce Burchett2, Dan G Blazer2, George E Woody3, Walter Ling41Departments of Epidemiology and Psychiatry, Columbia University, and the New York State Psychiatric Institute, New York City, NY; 2Department of Psychiatry and Behavioral Sciences, School of Medicine, Duke University Medical Center, Durham, NC; 3Department of Psychiatry, School of Medicine, University of Pennsylvania and Treatment Research Institute, Philadelphia, PA; 4David Geffen School of Medicine, NPI/Integrated Substance Abuse Programs, University of California, Los Angeles, CA, USABackground: In response to the rising rate of treatment admissions related to illicit use of amphetamines (eg, methamphetamine, we examined the prevalence of amphetamine use among treatment-seeking, opioid-dependent adults, explored whether amphetamine users were as likely as nonamphetamine users to enroll in opioid-dependence treatment trials, and determined whether amphetamine users manifested greater levels of medical and psychiatric comorbidity than nonusers.Methods: The sample included 1257 opioid-dependent adults screened for participation in threemultisite studies of the National Drug Abuse Treatment Clinical Trials Network (CTN001-003, which studied the effectiveness of buprenorphine for opioid detoxification under varying treatment conditions. Patients were recruited from 23 addiction treatment programs across the US. Medical and psychiatric comorbidity were examined by past-month amphetamine use (current vs former and route of administration. Five mutually exclusive groups were examined, ie, nonusers, current amphetamine injectors, current amphetamine noninjectors, former amphetamine injectors, and former amphetamine noninjectors.Results: Of the sample (n = 1257, 22.3% had a history of regular amphetamine use. Of the 280 amphetamine users, 30.3% reported injection as their primary route. Amphetamine users were more likely than nonusers to be white and use more

  12. DEPENDENCE OF YKL-40 mRNA TISSUE LEVELS ON KRAS MUTATION STATUS IN COLORECTAL CANCER - PRELIMINARY RESULTS

    Directory of Open Access Journals (Sweden)

    Yana Feodorova

    2015-08-01

    Full Text Available Colorectal cancer (CRC is one of the most deadly cancers worldwide. Despite the introduction of targeted molecular therapies in the last 10 years, overall survival has not increased substantially. CRC progression is accompanied by numerous genetic and epigenetic alterations and dysregulation of several signaling pathways, among which activation of Wnt and inactivation of TGF-β signaling. The molecular heterogeneity of CRC, however, hinders the molecular subtyping of CRC and thus the identification of common biomarkers for this pathology. The only three well established biomarkers for advanced-colorectal-cancer drug treatment are negative biomarkers. These are mutations in the genes KRAS, NRAS and BRAF which determine resistance to therapy with anti-EGFR antibodies. YKL-40 is a chitin-binding glycoprotein that has been shown to play a role in extracellular tissue remodeling, angiogenesis, cell migration and inflammation. Increased serum levels of this protein have been detected in patients with CRC but the role of YKL-40 in this neoplastic disease has not been studied extensively and the precise function of YKL-40 in CRC progression is not known. In the present study we determined the KRAS mutation status and measured the mRNA levels of YKL-40 of 24 patients with sporadic CRC. In addition, we assessed the association between these two parameters by statistical analysis. We are the first to show that in CRC YKL-40 mRNA levels are dependent on the presence of KRAS mutations, being prominently elevated in the wild type background. Our results indicate the potential role of YKL-40 as a target molecule for CRC therapy.

  13. Simulating cultural transmission: preliminary results and their implications for the study of formal variability of material culture in the Central Balkan Neolithic

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    Marko Porčić

    2014-12-01

    Full Text Available In this paper, we adopt the theoretical framework of evolutionary archaeology in order to model and simulate cultural transmission between hypothetical Neolithic sites in Balkans. We simulate neutral cultural transmission in order to compare the simulation results with empirically observed patterns of material culture variability such as traditional archaeological cultures. Our preliminary results show that a series of random local interactions can result in spatial groupings of typologically similar assemblages that correspond to the spatial distributions of traditional archaeological cultures, even in the absence of any other ‘external’ factor such as an overarching regional political structure or shared collective identity.

  14. Climate-dependent sediment production: numerical modeling and field observations of variable grain size distributions from heterogeneous hillslope weathering of fractured basalt flows, Kohala Peninsula, Hawaii

    Science.gov (United States)

    Murphy, B. P.; Johnson, J. P.

    2012-12-01

    in the length scale for the reduction in chemical weathering below the surface, or the flushing depth. The flushing depth is assumed to scale linearly with MAP, but decreases exponentially with increasing soil depth, as soil capillarity will imbibe infiltration. Modeling six MAP regimes between 500 and 3000 mm produces a non-linear increase in soil depths from 0.59 m soil to 5.15 m, which is broadly consistent with field observations from Kohala Peninsula. The median corestone grain size (D50) was calculated at model completion for the 20 blocks below the soil-rock interface. In the driest regime the D50 was 98% of that for the initial column, while the D50 for the wettest regime was 56% of the initial. This sediment preparation model predicts soil depths and tracks particle size reduction with variable climate-dependent weathering rates. Incorporating this type of model into sediment-transport dependent landscape evolution models may be the key to understanding the systematic differences in topography across spatially variable climate gradients, such as Kohala Peninsula.

  15. Multiple scales of temporal variability in ecosystem metabolism rates: results from two years of continuous monitoring in a forested headwater stream

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Brian J [ORNL; Mulholland, Patrick J [ORNL; Hill, Walter [ORNL

    2007-01-01

    Headwater streams are key sites of nutrient and organic matter processing and retention, but little is known about temporal variability in gross primary production (GPP) and ecosystem respiration (ER) rates as a result of the short duration of most ecosystem metabolism measurements in lotic ecosystems. We examined temporal variability and controls on ecosystem metabolism by measuring daily rates continuously for two years in Walker Branch, a first-order deciduous forest stream. Four important scales of temporal variability in ecosystem metabolism rates were identified: (1) seasonal, (2) day-to-day, (3) episodic (storm-related), and (4) inter-annual. Seasonal patterns were largely controlled by the leaf phenology and productivity of the deciduous riparian forest. Walker Branch was strongly net heterotrophic throughout the year with the exception of the open-canopy spring when GPP and ER rates were similar. Day-to-day variability in weather conditions influenced light reaching the streambed, resulting in high day-to-day variability in GPP particularly during spring (daily light levels explained 84% of the variance in daily GPP in April). Episodic storms depressed GPP for several days in spring, but increased GPP in autumn by removing leaves shading the streambed. Storms depressed ER initially, but then stimulated ER to 2-3 times pre-storm levels for several days. Walker Branch was strongly net heterotrophic in both years of the study (NEP = -1156 and -773 g O2 m-2 y-1), with annual GPP being similar (488 and 519 g O2 m-2 y-1) but annual ER being higher in 2004 than 2005 (-1645 vs. -1292 g O2 m-2 y-1). Inter-annual variability in ecosystem metabolism (assessed by comparing 2004 and 2005 rates with previous measurements) was the result of the storm frequency and timing and the size of the spring macroalgal bloom. Changes in local climate can have substantial impacts on stream ecosystem metabolism rates and ultimately influence the carbon source and sink properties of

  16. Is magnitude variability on North-Anatolian and San-Andreas fault segments a consequence of geometry and resultant irregular tectonic loading?

    Science.gov (United States)

    Parsons, T.

    2006-12-01

    Large earthquakes of varying magnitude are observed rupturing the same fault segments on the North Anatolian fault in Turkey, and on the San Andreas fault in California. In Turkey there enough reports of historical earthquake damage [Ambraseys, 2002] to assemble a ~500-yr catalog of M greater than 7 events along the Marmara-Sea portion of the right-lateral obliquely divergent North Anatolian fault. In California, analysis by Weldon et al. [2004, 2005] from paleoseismology on the right-lateral obliquely convergent southern San Andreas fault enabled a long slip-history at the Wrightwood site. In both cases there is resolvable magnitude variation on fault segments where at least two large earthquakes ruptured the same point(s). Characteristic earthquake models posit that repeated versions of the same earthquake rupture fault segments over time, and form the basis for time-dependent probability calculations. Finite element models of the North Anatolian and San Andreas fault systems driven by geodetically-determined displacements show variable long- term stress-loading on these faults. Stressing-rate variability comes from changes in fault geometry along strike, non-uniform motions of crustal blocks, and fault interactions. The North Anatolian and San Andreas finite element models show parts of faults achieving failure stresses sooner than others. Modeled heterogeneous fault loading suggests complex rupture sequences that are consistent with observations.

  17. Blade-order-dependent radiocarbon variability in brown seaweed (Undaria pinnatifida) reflected a cold Oyashio water intrusion event in an embayment of the Sanriku coast, northeastern Japan

    Science.gov (United States)

    Satoh, N.; Fukuda, H.; Miyairi, Y.; Yokoyama, Y.; Nagata, T.

    2015-12-01

    Radiocarbon in dissolved inorganic carbon (DIC) in seawater varies greatly, both geographically and with depth. This "reservoir effect" is thought to be reflected in the radiocarbon content (∆14C) of marine organisms, via DIC fixation by primary producers and subsequent trophic transfer. The ∆14C of marine organismal soft tissues might thus provide unique information about their habitats, diets, migration and other environmental histories. However, the effectiveness of this approach has yet to be extensively explored, with data on ∆14C variability in soft tissues of marine organisms being markedly limited. Here we examined whether ∆14C values of individual pinnate blades (leaf-like structures) of brown seaweed (Undaria pinnatifida) reflect the ∆14C of DIC in the water current prevailing at the time of blade formation. The study was conducted in Otsuchi Bay located in the Sanriku coastal region, northeastern Japan, where 14C-depleted cold Oyashio current and warm Tsugaru current (high ∆14C) converge, affecting the physiology and growth of marine organisms growing there. U. pinnatifida individuals cultured in the bay (length of saprophytes, 140-215 cm) were harvested in April 2014 and ∆14C of blades were determined by accelerator mass spectrometry. Younger blades formed after the Oyashio water intrusion had significantly lower ∆14C values compared to older blades formed before the event. The ∆14C values of younger and older blades were generally consistent with the ∆14C of DIC in Oyashio (-60.5 ‰) and Tsugaru (24.9 ‰) waters, respectively. Thus, despite possible turnover of organic carbon in seaweed soft tissues, blade-order-dependent ∆14C variability appeared to strongly reflect the Oyashio intrusion event (radiocarbon shift) in the bay.

  18. Degree of multicollinearity and variables involved in linear dependence in additive-dominant models Grau de multicolinearidade e variáveis envolvidas na dependência linear em modelos aditivo-dominantes

    Directory of Open Access Journals (Sweden)

    Juliana Petrini

    2012-12-01

    Full Text Available The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567, yearling weight (n=58,124, and scrotal circumference (n=20,371 of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.O objetivo deste trabalho foi avaliar o grau de multicolinearidade e identificar as variáveis envolvidas na dependência linear em modelos aditivo-dominantes. Foram utilizados dados de peso ao nascimento (n=141.567, peso ao ano (n=58.124 e perímetro escrotal (n=20.371 de bovinos de corte compostos Montana Tropical. O diagnóstico de multicolinearidade foi baseado no fator de inflação de variância (VIF e no exame dos índices de condição e dos autovalores da matriz de correlações entre as variáveis explanatórias. O primeiro modelo estudado (RM incluiu o efeito fixo de classe de idade da mãe ao parto e

  19. Preliminary results from the ESA STSE project on SST diurnal variability, its regional extent and implications in atmospheric modelling (SSTDV:R.EX.–IM.A.M.)

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Hasager, Charlotte Bay; Høyer, Jacob L.

    2013-01-01

    This study presents some preliminary results of the ESA Support To Science Element (STSE) funded project on the Diurnal Variability of the Sea Surface Temperature, regarding its Regional Extend and Implications in Atmospheric Modelling (SSTDV:R.EX.–IM.A.M.). Comparisons of SEVIRI SST with AATSR......, the 1-dimensional General Ocean Turbulence Model (GOTM) is applied. Preliminary results show that the initial temperature and salinity profiles may give a warmer start-up in the model while the light extinction scheme is a controlling factor for the amplitude and vertical extend of the daily signal....

  20. Deferasirox in iron-overloaded patients with transfusion-dependent myelodysplastic syndromes: Results from the large 1-year EPIC study

    DEFF Research Database (Denmark)

    Gattermann, Norbert; Finelli, Carlo; Porta, Matteo Della;

    2010-01-01

    patients were chelation-naïve or previously chelated; changes were dependent on dose adjustments and ongoing iron intake. Sustained reductions in labile plasma iron were observed. Discontinuation rate (48.7%) and adverse event profile were consistent with previously reported deferasirox data in MDS...

  1. Time-dependent hydrogen ionisation in 3D simulations of the solar chromosphere. Methods and first results

    NARCIS (Netherlands)

    Leenaarts, J.; Wedemeyer-Bohm, S.

    2006-01-01

    Context. The hydrogen ionisation degree deviates substantially from statistical equilibrium under the conditions of the solar chromosphere. A realistic description of this atmospheric layer thus must account for time-dependent non-equilibrium effects. Aims. Advancing the realism of numerical simulat

  2. On the Strong Rates of Convergence for Arrays of Rowwise Extended Negatively Dep endent Random Variables

    Institute of Scientific and Technical Information of China (English)

    ZHENG Lu-lu; XU Chen; HUANG Xu-feng; WANG Xue-jun

    2014-01-01

    A general result on the strong convergence rate and complete convergence for arrays of rowwise extended negatively dependent random variables is established. As ap-plications, some well-known results on negatively dependent random variables can be easily extended to the case of arrays of rowwise extended negatively dependent random variables.

  3. The dependence on atmospheric resolution of ENSO and related East Asian-western North Pacific summer climate variability in a coupled model

    Science.gov (United States)

    Liu, Bo; Zhao, Guijie; Huang, Gang; Wang, Pengfei; Yan, Bangliang

    2017-08-01

    The authors present results for El Niño-Southern Oscillation (ENSO) and East Asian-western North Pacific climate variability simulated in a new version high-resolution coupled model (ICM.V2) developed at the Center for Monsoon System Research of the Institute of Atmospheric Physics (CMSR, IAP), Chinese Academy of Sciences. The analyses are based on the last 100-year output of a 1000-year simulation. Results are compared to an earlier version of the same coupled model (ICM.V1), reanalysis, and observations. The two versions of ICM have similar physics but different atmospheric resolution. The simulated climatological mean states show marked improvement over many regions, especially the tropics in ICM.V2 compared to those in ICM.V1. The common bias in the cold tongue has reduced, and the warm biases along the ocean boundaries have improved as well. With improved simulation of ENSO, including its period and strength, the ENSO-related western North Pacific summer climate variability becomes more realistic compared to the observations. The simulated East Asian summer monsoon anomalies in the El Niño decaying summer are substantially more realistic in ICM.V2, which might be related to a better simulation of the Indo-Pacific Ocean capacitor (IPOC) effect and Pacific decadal oscillation (PDO).

  4. Ashtekar variables

    Science.gov (United States)

    Ashtekar, Abhay

    2015-05-01

    In the spirit of Scholarpedia, this invited article is addressed to students and younger researchers. It provides the motivation and background material, a summary of the main physical ideas, mathematical structures and results, and an outline of applications of the connection variables for general relativity. These variables underlie both the canonical/Hamiltonian and the spinfoam/path integral approaches in loop quantum gravity.

  5. Intra-individual Neurocognitive Variability Confers Risk of Dependence in Activities of Daily Living among HIV-Seropositive Individuals without HIV-Associated Neurocognitive Disorders

    Science.gov (United States)

    Morgan, Erin E.; Woods, Steven Paul; Grant, Igor

    2012-01-01

    Although HIV-associated neurocognitive disorders (HAND) are the strong predictors of everyday functioning difficulties, approximately half of all functionally impaired individuals are labeled “neurocognitively normal” according to the standard neuropsychological measures, suggesting that novel predictors of functional problems in this prevalent subgroup are needed. The present study hypothesized that increased neurocognitive intra-individual variability as indexed by dispersion would be associated with poor daily functioning among 82 persons with HIV infection who did not meet research criteria for HAND. An intra-individual standard deviation was calculated across the demographically adjusted T-scores of 13 standard neuropsychological tests to represent dispersion, and functional outcomes included self-reported declines in basic and instrumental activities of daily functioning (basic activity of daily living [BADL] and instrumental activity of daily living [IADL], respectively) and medication management. Dispersion was a significant predictor of medication adherence and dependence in both BADL and IADL, even when other known predictors of functional status (i.e., age, affective distress, and indices of disease severity) were included in the models. As a significant and unique predictor of a performance on the range of daily functioning activities, neurocognitive dispersion may be indicative of deficient cognitive control expressed as inefficient regulation of neurocognitive resources in the context of competing functional demands. As such, dispersion may have clinical utility in detecting risk for functional problems among HIV-infected individuals without HAND. PMID:22337933

  6. Charge-state-dependent energy loss of slow ions. I. Experimental results on the transmission of highly charged ions

    Science.gov (United States)

    Wilhelm, Richard A.; Gruber, Elisabeth; Smejkal, Valerie; Facsko, Stefan; Aumayr, Friedrich

    2016-05-01

    We report on energy loss measurements of slow (v ≪v0 ), highly charged (Q >10 ) ions upon transmission through a 1-nm-thick carbon nanomembrane. We emphasize here the scaling of the energy loss with the velocity and charge exchange or loss. We show that a weak linear velocity dependence exists, whereas charge exchange dominates the kinetic energy loss, especially in the case of a large charge capture. A universal scaling of the energy loss with the charge exchange and velocity is found and discussed in this paper. A model for charge-state-dependent energy loss for slow ions is presented in paper II in this series [R. A. Wilhelm and W. Möller, Phys. Rev. A 93, 052709 (2016), 10.1103/PhysRevA.93.052709].

  7. Can a soda-lime glass be used to demonstrate how patterns of strength dependence are influenced by pre-cementation and resin-cementation variables?

    LENUS (Irish Health Repository)

    Hooi, Paul

    2013-01-01

    To determine how the variability in biaxial flexure strength of a soda-lime glass analogue for a PLV and DBC material was influenced by precementation operative variables and following resin-cement coating.

  8. Interaction of the phospholipid scramblase 1 with HIV-1 Tat results in the repression of Tat-dependent transcription

    Energy Technology Data Exchange (ETDEWEB)

    Kusano, Shuichi, E-mail: skusano@m2.kufm.kagoshima-u.ac.jp; Eizuru, Yoshito

    2013-04-19

    Highlights: •PLSCR1 specifically interacted with HIV-1 Tat in vitro and in vivo. •PLSCR1 repressed Tat-dependent transactivation of the HIV-1 LTR. •Suppression of PLSCR1 expression enhanced the levels of HIV-1 transcripts. •PLSCR1 reduced the nuclear localization of Tat. -- Abstract: Human phospholipid scramblase 1 (PLSCR1) is an interferon (IFN)-stimulated gene and possesses an IFN-mediated antiviral function. We show here that PLSCR1 directly interacts with human immunodeficiency virus type-1 (HIV-1) Tat. This interaction occurs both in vitro and in vivo through amino acids 160–250 of PLSCR1. Overexpression of PLSCR1 efficiently represses the Tat-dependent transactivation of the HIV-1 long terminal repeat (LTR) and reduces the nuclear translocation of Tat. In addition, shRNA-mediated suppression of endogenous PLSCR1 expression enhances the levels of gag mRNA in an HIV-1-infected T-cell line. These findings indicate that PLSCR1 negatively regulates the Tat-dependent transactivation of the HIV-1 LTR during HIV-1 infection.

  9. Explicating the Conditions Under Which Multilevel Multiple Imputation Mitigates Bias Resulting from Random Coefficient-Dependent Missing Longitudinal Data.

    Science.gov (United States)

    Gottfredson, Nisha C; Sterba, Sonya K; Jackson, Kristina M

    2017-01-01

    Random coefficient-dependent (RCD) missingness is a non-ignorable mechanism through which missing data can arise in longitudinal designs. RCD, for which we cannot test, is a problematic form of missingness that occurs if subject-specific random effects correlate with propensity for missingness or dropout. Particularly when covariate missingness is a problem, investigators typically handle missing longitudinal data by using single-level multiple imputation procedures implemented with long-format data, which ignores within-person dependency entirely, or implemented with wide-format (i.e., multivariate) data, which ignores some aspects of within-person dependency. When either of these standard approaches to handling missing longitudinal data is used, RCD missingness leads to parameter bias and incorrect inference. We explain why multilevel multiple imputation (MMI) should alleviate bias induced by a RCD missing data mechanism under conditions that contribute to stronger determinacy of random coefficients. We evaluate our hypothesis with a simulation study. Three design factors are considered: intraclass correlation (ICC; ranging from .25 to .75), number of waves (ranging from 4 to 8), and percent of missing data (ranging from 20 to 50%). We find that MMI greatly outperforms the single-level wide-format (multivariate) method for imputation under a RCD mechanism. For the MMI analyses, bias was most alleviated when the ICC is high, there were more waves of data, and when there was less missing data. Practical recommendations for handling longitudinal missing data are suggested.

  10. Optimising iron chelation therapy with deferasirox for non-transfusion-dependent thalassaemia patients: 1-year results from the THETIS study.

    Science.gov (United States)

    Taher, Ali T; Cappellini, M Domenica; Aydinok, Yesim; Porter, John B; Karakas, Zeynep; Viprakasit, Vip; Siritanaratkul, Noppadol; Kattamis, Antonis; Wang, Candace; Zhu, Zewen; Joaquin, Victor; Uwamahoro, Marie José; Lai, Yong-Rong

    2016-03-01

    Efficacy and safety of iron chelation therapy with deferasirox in iron-overloaded non-transfusion-dependent thalassaemia (NTDT) patients were established in the THALASSA study. THETIS, an open-label, single-arm, multicentre, Phase IV study, added to this evidence by investigating earlier dose escalation by baseline liver iron concentration (LIC) (week 4: escalation according to baseline LIC; week 24: adjustment according to LIC response, maximum 30mg/kg/day). The primary efficacy endpoint was absolute change in LIC from baseline to week 52. 134 iron-overloaded non-transfusion-dependent anaemia patients were enrolled and received deferasirox starting at 10mg/kg/day. Mean actual dose±SD over 1year was 14.70±5.48mg/kg/day. At week 52, mean LIC±SD decreased significantly from 15.13±10.72mg Fe/g dw at baseline to 8.46±6.25mg Fe/g dw (absolute change from baseline, -6.68±7.02mg Fe/g dw [95% CI: -7.91, -5.45]; P<0.0001). Most common drug-related adverse events were gastrointestinal: abdominal discomfort, diarrhoea and nausea (n=6 each). There was one death (pneumonia, not considered drug related). With significant and clinically relevant reductions in iron burden alongside a safety profile similar to that in THALASSA, these data support earlier escalation with higher deferasirox doses in iron-overloaded non-transfusion-dependent anaemia patients.

  11. Parent, sibling and peer influences on smoking initiation, regular smoking and nicotine dependence. Results from a genetically informative design.

    Science.gov (United States)

    Scherrer, Jeffrey F; Xian, Hong; Pan, Hui; Pergadia, Michele L; Madden, Pamela A F; Grant, Julia D; Sartor, Carolyn E; Haber, Jon Randolph; Jacob, Theodore; Bucholz, Kathleen K

    2012-03-01

    We sought to determine whether parenting, sibling and peer influences are associated with offspring ever smoking, regular smoking and nicotine dependence (ND) after controlling for familial factors. We used a twin-family design and data from structured diagnostic surveys of 1919 biological offspring (ages 12-32 years), 1107 twin fathers, and 1023 mothers. Offspring were classified into one of four familial risk groups based on twin fathers' and their co-twins' history of DSM-III-R nicotine dependence. Multivariate multinomial logistic regression was used to model familial risk, paternal and maternal parenting behavior and substance use, sibling substance use, and friend and school peer smoking, alcohol and drug use. Ever smoking was associated with increasing offspring age, white race, high maternal pressure to succeed in school, sibling drug use, and friend smoking, alcohol and drug use. Offspring regular smoking was associated with these same factors with additional contribution from maternal ND. Offspring ND was associated with increasing offspring age, male gender, biological parents divorce, high genetic risk from father and mother ND, maternal problem drinking, maternal rule inconsistency and sibling drug use, and friend smoking, alcohol and drug use. Friend smoking had the largest magnitude of association with offspring smoking. This effect remains after accounting for familial liability and numerous parent and sibling level effects. Smoking interventions may have greatest impact by targeting smoking prevention among peer groups in adolescent and young adult populations.

  12. Model prediction for temperature dependence of meson pole masses from lattice QCD results on meson screening masses

    CERN Document Server

    Ishii, Masahiro; Yahiro, Masanobu

    2016-01-01

    We propose a practical effective model by introducing temperature ($T$) dependence to the coupling strengths of four-quark and six-quark Kobayashi-Maskawa-'t Hooft interactions in the 2+1 flavor Polyakov-loop extended Nambu-Jona-Lasinio model. The $T$ dependence is determined from LQCD data on the renormalized chiral condensate around the pseudocritical temperature $T_c^{\\chi}$ of chiral crossover and the screening-mass difference between $\\pi$ and $a_0$ mesons in $T > 1.1T_c^\\chi$ where only the $U(1)_{\\rm A}$-symmetry breaking survives. The model well reproduces LQCD data on screening masses $M_{\\xi}^{\\rm scr}(T)$ for both scalar and pseudoscalar mesons, particularly in $T \\ge T_c^{\\chi}$. Using this effective model, we predict meson pole masses $M_{\\xi}^{\\rm pole}(T)$ for scalar and pseudoscalar mesons. For $\\eta'$ meson, the prediction is consistent with the experimental value at finite $T$ measured in heavy-ion collisions. We point out that the relation $M_{\\xi}^{\\rm scr}(T)-M_{\\xi}^{\\rm pole}(T) \\approx...

  13. Association of ADH4 genetic variants with alcohol dependence risk and related phenotypes: results from a larger multicenter association study.

    Science.gov (United States)

    Preuss, Ulrich W; Ridinger, Monika; Rujescu, Dan; Samochowiec, Jerzy; Fehr, Christoph; Wurst, Friedrich M; Koller, Gabriele; Bondy, Brigitta; Wodarz, Norbert; Debniak, Tadeusz; Grzywacz, Anna; Soyka, Michael; Zill, Peter

    2011-04-01

    Genetic variants of the alcohol-metabolizing enzyme ADH4, located on chromosome 4q22-4q23, have been related to alcohol dependence (AD) risk in previous research. The aim of this association study in a large multicenter sample of alcohol-dependent individuals and controls is to confirm ADH4 single nucleotide polymorphism (SNP) and haplotype association with AD and relevant related phenotypes. One thousand, six hundred and twenty-two (1622) inpatient subjects and 1469 control subjects with DSM-IV. AD from four addiction treatment centres were included. Characteristics of AD and related phenotypes including alcohol withdrawal, Cloninger's type I and II and first ages of drinking, regular drinking and AD onset were obtained using standardized structured interviews. After subjects were genotyped for 2 ADH4 polymorphisms, single SNP case-control and haplotype analyses were conducted. Both variants--rs1800759 and rs1042364--and the A-A and C-G haplotypes were significantly related to AD across samples. Furthermore, associations with AD-related phenotypes and subtypes revealed a potential protective influence of this haplotype. This study confirms the significant relationship of ADH4 variants with AD and related phenotypes. While the rs1800759 and rs1042364 A-A haplotype had a potential protective influence on the risk for several AD-related phenotypes, this effect is rather small compared to functional variants of other alcohol or acetaldehyde-metabolizing enzymes like ALDH2*2 or ADH1B*2.

  14. Monte Carlo Bayesian Inference on a Statistical Model of Sub-gridcolumn Moisture Variability Using High-resolution Cloud Observations . Part II; Sensitivity Tests and Results

    Science.gov (United States)

    da Silva, Arlindo M.; Norris, Peter M.

    2013-01-01

    Part I presented a Monte Carlo Bayesian method for constraining a complex statistical model of GCM sub-gridcolumn moisture variability using high-resolution MODIS cloud data, thereby permitting large-scale model parameter estimation and cloud data assimilation. This part performs some basic testing of this new approach, verifying that it does indeed significantly reduce mean and standard deviation biases with respect to the assimilated MODIS cloud optical depth, brightness temperature and cloud top pressure, and that it also improves the simulated rotational-Ramman scattering cloud optical centroid pressure (OCP) against independent (non-assimilated) retrievals from the OMI instrument. Of particular interest, the Monte Carlo method does show skill in the especially difficult case where the background state is clear but cloudy observations exist. In traditional linearized data assimilation methods, a subsaturated background cannot produce clouds via any infinitesimal equilibrium perturbation, but the Monte Carlo approach allows finite jumps into regions of non-zero cloud probability. In the example provided, the method is able to restore marine stratocumulus near the Californian coast where the background state has a clear swath. This paper also examines a number of algorithmic and physical sensitivities of the new method and provides guidance for its cost-effective implementation. One obvious difficulty for the method, and other cloud data assimilation methods as well, is the lack of information content in the cloud observables on cloud vertical structure, beyond cloud top pressure and optical thickness, thus necessitating strong dependence on the background vertical moisture structure. It is found that a simple flow-dependent correlation modification due to Riishojgaard (1998) provides some help in this respect, by better honoring inversion structures in the background state.

  15. Height-dependence of spatio-temporal spectra of wall-bounded turbulence - LES results and model predictions

    CERN Document Server

    Wilczek, Michael; Meneveau, Charles

    2016-01-01

    Wavenumber-frequency spectra of the streamwise velocity component obtained from large-eddy simulations are presented. Following a recent paper [Wilczek et al., J. Fluid. Mech., 769:R1, 2015] we show that the main features, a Doppler shift and a Doppler broadening of frequencies, are captured by an advection model based on the Tennekes-Kraichnan random-sweeping hypothesis with additional mean flow. In this paper, we focus on the height-dependence of the spectra within the logarithmic layer of the flow. We furthermore benchmark an analytical model spectrum that takes the predictions of the random-sweeping model as a starting point and find good agreement with the LES data. We also quantify the influence of LES grid resolution on the wavenumber-frequency spectra.

  16. [Activation-dependent characteristics of the electroencephalogram during visual information--processing: Results of an automatic interval analysis (author's transl)].

    Science.gov (United States)

    Bastek, R; Gille, H G; Gruner, P; Otto, E; Ullsperger, P

    1976-01-01

    EEG signal from fronto-occipital derivation was recorded in 16 Ss during a mental performance test (modified "Konzentrations-Leistungs-Test" including four levels of performance). A balanced changer-over design was used. Interval histograms in four frequency bands (theta, alpha, beta-1 and beta-2 bands) were determined on the basis of peak detection. A total of 44 characteristics were derived and tested (multi-factor analyses of variance, multiple mean comparison and rank tests). Twenty eight of these characteristics were proved to be dependent on activation. In the visual information-processing performances chosen, it could be demonstrated that the intraindividual changes of the spontaneous EEG activity were related predominantly to the perceptual components of the performance. On the other hand, the influence of the performance rate and of the mental-arithmetic itself was of minor relevance. During higher activation an increase in the relative abudance of the theta-band activity was also observed.

  17. [Stabilizing the social and health status of drug dependent patients with methadone. Long-term maintainance therapy--Vienna results].

    Science.gov (United States)

    Loimer, N; Werner, E; Hollerer, E; Pfersmann, V; Schmid-Siegel, B; Presslich, O

    1991-01-01

    On September 25th, 1987 methadone was legalized in Austria for therapeutic use in drug addiction treatment in case of: 1. Long-term drug addiction with intravenous application of the drug, and several unsuccessful withdrawal therapies and/or 2. opiate addiction through intravenous application of the drug along with an existing HIV-1 infection. Since than, 291 patients were treated with methadone at the drug-dependency outpatient clinic of the Psychiatric Clinic of the University of Vienna. In 1990, 96 patients treated for more than one year were investigated using a standardized questionnaire. The image in which crime, prostitution, poverty, ill health all merge was broken by this decriminalization. Methadone treatment offers a first step toward social rehabilitation for drug addicts who have been living as criminals on the fringe of society.

  18. Tensile properties of the hip joint ligaments are largely variable and age-dependent - An in-vitro analysis in an age range of 14-93 years.

    Science.gov (United States)

    Schleifenbaum, Stefan; Prietzel, Torsten; Hädrich, Carsten; Möbius, Robert; Sichting, Freddy; Hammer, Niels

    2016-10-03

    Hip joint stability is maintained by the surrounding ligaments, muscles, and the atmospheric pressure exerted via these structures. It is unclear whether the ligaments are capable of preventing dislocation solely due to their tensile properties, and to what extent they undergo age-related changes. This study aimed to obtain stress-strain data of the hip ligaments over a large age range. Stress-strain data of the iliofemoral (IL), ischiofemoral (IS) and pubofemoral ligament (PF) were obtained from cadavers ranging between 14 and 93 years using a highly standardized setting. Maximum strains were compared to the distances required for dislocation. Elastic modulus was 24.4 (IL), 22.4 (IS) and 24.9N/mm(2) (PF) respectively. Maximum strain was 84.5%, 86.1%, 72.4% and ultimate stress 10.0, 7.7 and 6.5N/mm(2) for the IL, IS and PF respectively. None of these values varied significantly between ligaments or sides. The IS' elastic modulus was higher and maximum strain lower in males. Lower elastic moduli of the PF and higher maximum strains for the IS and PF were revealed in the ≥55 compared to the <55 population. Maximum strain exceeded the dislocation distance of the IS without external hip joint rotation in females, and of the IS and cranial IL under external rotation in both genders. Tensile and failure load properties of the hip joint ligaments are largely variable. The IS and PF change age-dependently. Though the hip ligaments contribute to hip stability, the IS and cranial IL may not prevent dislocation due to their elasticity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Preliminary Results for the OECD/NEA Time Dependent Benchmark using Rattlesnake, Rattlesnake-IQS and TDKENO

    Energy Technology Data Exchange (ETDEWEB)

    DeHart, Mark D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mausolff, Zander [Univ. of Florida, Gainesville, FL (United States); Weems, Zach [Univ. of Florida, Gainesville, FL (United States); Popp, Dustin [Univ. of Florida, Gainesville, FL (United States); Smith, Kristin [Univ. of Florida, Gainesville, FL (United States); Shriver, Forrest [Univ. of Florida, Gainesville, FL (United States); Goluoglu, Sedat [Univ. of Florida, Gainesville, FL (United States); Prince, Zachary [Texas A & M Univ., College Station, TX (United States); Ragusa, Jean [Texas A & M Univ., College Station, TX (United States)

    2016-08-01

    One goal of the MAMMOTH M&S project is to validate the analysis capabilities within MAMMOTH. Historical data has shown limited value for validation of full three-dimensional (3D) multi-physics methods. Initial analysis considered the TREAT startup minimum critical core and one of the startup transient tests. At present, validation is focusing on measurements taken during the M8CAL test calibration series. These exercises will valuable in preliminary assessment of the ability of MAMMOTH to perform coupled multi-physics calculations; calculations performed to date are being used to validate the neutron transport solver Rattlesnake\\cite{Rattlesnake} and the fuels performance code BISON. Other validation projects outside of TREAT are available for single-physics benchmarking. Because the transient solution capability of Rattlesnake is one of the key attributes that makes it unique for TREAT transient simulations, validation of the transient solution of Rattlesnake using other time dependent kinetics benchmarks has considerable value. The Nuclear Energy Agency (NEA) of the Organization for Economic Cooperation and Development (OECD) has recently developed a computational benchmark for transient simulations. This benchmark considered both two-dimensional (2D) and 3D configurations for a total number of 26 different transients. All are negative reactivity insertions, typically returning to the critical state after some time.

  20. Radial deformation of single-walled carbon nanotubes on quartz substrates and the resultant anomalous diameter-dependent reaction selectivity

    Institute of Scientific and Technical Information of China (English)

    Juan Yang; Yu Liu; Daqi Zhang; Xiao Wang; Ruoming Li; Yan Li

    2015-01-01

    Owing to the unique conjugated structure, the chemical-reaction selectivity of single-walled carbon nanotubes (SWNTs) has attracted great attention. By utilizing the radial deformation of SWNTs caused by the strong interactions with the quartz lattice, we achieve an anomalous diameter-dependent reaction selectivity of quartz lattice-oriented SWNTs in treatment with iodine vapor; this is distinctly different from the widely reported and well accepted higher reaction activity in small-diameter tubes compared to large-diameter tubes. The radial deformation of SWNTs on quartz substrate is verified by detailed Raman spectroscopy and mappings in both G-band and radial breathing mode. Due to the strong interaction between SWNTs and the quartz lattice, large-diameter tubes present a larger degree of radial deformation and more delocalized partial electrons are distributed at certain sidewall sites with high local curvature. It is thus easier for the carbon--carbon bonds at these high-curvature sites on large-diameter tubes to break down during reaction. This anomalous reaction activity offers a novel approach for selective removal of small-band~aD large-diameter tubes.

  1. New Closed-Form Results on Ordered Statistics of Partial Sums of Gamma Random Variables and its Application to Performance Evaluation in the Presence of Nakagami Fading

    KAUST Repository

    Nam, Sung Sik

    2017-06-19

    Complex wireless transmission systems require multi-dimensional joint statistical techniques for performance evaluation. Here, we first present the exact closed-form results on order statistics of any arbitrary partial sums of Gamma random variables with the closedform results of core functions specialized for independent and identically distributed Nakagami-m fading channels based on a moment generating function-based unified analytical framework. These both exact closed-form results have never been published in the literature. In addition, as a feasible application example in which our new offered derived closed-form results can be applied is presented. In particular, we analyze the outage performance of the finger replacement schemes over Nakagami fading channels as an application of our method. Note that these analysis results are directly applicable to several applications, such as millimeter-wave communication systems in which an antenna diversity scheme operates using an finger replacement schemes-like combining scheme, and other fading scenarios. Note also that the statistical results can provide potential solutions for ordered statistics in any other research topics based on Gamma distributions or other advanced wireless communications research topics in the presence of Nakagami fading.

  2. Variability in the Propagation Phase of CFD-Based Noise Prediction: Summary of Results From Category 8 of the BANC-III Workshop

    Science.gov (United States)

    Lopes, Leonard; Redonnet, Stephane; Imamura, Taro; Ikeda, Tomoaki; Zawodny, Nikolas; Cunha, Guilherme

    2015-01-01

    The usage of Computational Fluid Dynamics (CFD) in noise prediction typically has been a two part process: accurately predicting the flow conditions in the near-field and then propagating the noise from the near-field to the observer. Due to the increase in computing power and the cost benefit when weighed against wind tunnel testing, the usage of CFD to estimate the local flow field of complex geometrical structures has become more routine. Recently, the Benchmark problems in Airframe Noise Computation (BANC) workshops have provided a community focus on accurately simulating the local flow field near the body with various CFD approaches. However, to date, little effort has been given into assessing the impact of the propagation phase of noise prediction. This paper includes results from the BANC-III workshop which explores variability in the propagation phase of CFD-based noise prediction. This includes two test cases: an analytical solution of a quadrupole source near a sphere and a computational solution around a nose landing gear. Agreement between three codes was very good for the analytic test case, but CFD-based noise predictions indicate that the propagation phase can introduce 3dB or more of variability in noise predictions.

  3. Dependence of the results of ecological-epidemic investigation of influenza A(H1N1) on immunity

    Science.gov (United States)

    Fathudinova, Mohinav; Alimova, Barno; Rahimova, Halima

    2016-07-01

    This report presents the results of ecology-epidemical and immunological researches influ-enza virus A (H1 N1) and acute respiratory infection in Dushanbe from 2011 till 2015. The received results epidemiological and immunological analysis showed us, that last years has been changed not only characteristics of influenza epidemic, but it can not be notice the low-er of intensively of the collective immunity to actual versions influenza viruses A and B

  4. Superorbital variability of X-ray and radio emission of Cyg X-1 - II. Dependence of the orbital modulation on the superorbital phase

    CERN Document Server

    Poutanen, Juri; Ibragimov, Askar

    2008-01-01

    We discover a pronounced dependence of the strength of the soft X-ray orbital modulation in Cyg X-1 in the hard state on its superorbital phase. We find our results can be well modelled as orbital-phase dependent X-ray absorption in an accretion bulge, located at the accretion disc edge close to the companion but displaced from the line connecting the stars by about 25^o and in the case when the disc is precessing (which appears to cause the superorbital flux modulation). Our finding are supported by the distribution of the X-ray dips showing concentration towards zero superorbital phase, which corresponds to the bulge passing through the line of sight. We Fourier analyse our model, and find it explains the previous finding of asymmetric beat (between the orbital and superorbital modulations) frequencies in the observed power spectrum, provided the disc precession is prograde. On the other hand, we find no statistically significant changes of the orbital modulation with the superorbital phase in the 15-GHz ra...

  5. Asymptotic behavior of ratio-dependent chemostat model with variable yield%具有变消耗率的比率确定型chemostat模型渐近行为

    Institute of Scientific and Technical Information of China (English)

    孙树林; 陈兰荪

    2007-01-01

    To make the theoretical analysis of the microbial continuous culture more close to the experimental results, a ratio-dependent chemostat model with variable yield is formulated. The model develops the classical Monod model and assumes that the yield is a linear function of the nutrient concentration and the microbial growth rate is a ratio-dependent type function. Qualitative analysis is implemented on this model. It is shown that the system is permanent if and only if it has a positive equilibrium. The sufficient conditions of existence of limit cycles and globally asymptotic stability of the positive equilibrium for the model are given.%为了使微生物培养的理论研究更接近于实验,建立了一个具有变消耗率的比率确定型chemostat模型.这个模型推广了经典的Monod模型,而且假定了消耗率是一个营养基的线性函数,微生物增长率是比率确定型函数.对该模型作了定性分析,证明了只要正平衡点存在系统就是持续生存的.同时也给出了系统极限环存在和正平衡点全局渐近稳定的充分条件.

  6. [Femtosecond laser-assisted lens surgery depending on interface design and laser pulse energy: results of the first 200 cases].

    Science.gov (United States)

    Mayer, W J; Klaproth, O K; Ostovic, M; Hengerer, F H; Kohnen, T

    2014-12-01

    This study was designed to evaluate the effectiveness and safety of femtosecond laser-assisted lens surgery depending on interface design and laser pulse energy settings. In this non-randomized, consecutive case series200 eyes underwent femtosecond laser-assisted (LenSx, Alcon) lens surgery between November 2012 and June 2013. Group 1 consisted of 85 eyes with 60 cataracts and 25 refractive lens exchanges (RLE) which were treated with a curved direct contact interface, and group 2 consisting of 115 eyes with 72 cataracts and 43 RLEs treated with a modified interface using an additional soft contact lens (SoftFit™, Alcon) between the corneal surface and the interface. The degree of opacity of the lens in cataract eyes was measured with a Scheimpflug camera. Afterwards, phacoemulsification was performed with intraocular lens (IOL) implantation in all eyes. Primary endpoints were the effective phacoemulsification time (EPT), the average laser treatment time and the occurrence of intraoperative complications. The mean EPT in group 1 was 1.62 ± 1.12 s (cataract 1.94 ± 1.31 s, RLE 1.29 ± 1.01 s) and in group 2 the mean EPT was 1.66 ± 0.92 s (cataract 1.98 ± 1.28 s, RLE 1.33 ± 1.22 s, p = 0.32 between groups). The laser treatment lasted on average 48.90 ± 2.45 s (group 1) and 49.70 ± 2.87 s (group 2) with an average lens fragmentation thickness of 3401.48 ± 401.12 µm (all groups). In four cases of group 1, a second applanation of the interface was necessary. Furthermore, one anterior capsule tear, 39 cases of intraoperative wrinkling of the corneal surface and 21 cases in which the corneal incision had to be opened manually were documented in group 1. In group 2 no second applanation of the interface, no anterior capsule tears and no corneal wrinkling but 9 cases with a manual opening of corneal incisions were documented (p interface and reduced laser pulse energy.

  7. Continuous Auricular Electroacupuncture Can Significantly Improve Heart Rate Variability and Clinical Scores in Patients with Depression: First Results from a Transcontinental Study

    Directory of Open Access Journals (Sweden)

    Xian Shi

    2013-01-01

    Full Text Available The goal of this study was to investigate the impact and acceptability of providing continuous auricular electroacupuncture as an adjunct to conventional medications for patients with depression. Ten patients with a mean age ± SD of 43.3 ± 10.4 years were able to provide informed consent. The quantitative and qualitative outcome measures were heart rate, heart rate variability (HRV, and different clinical scores. The study documented that a special kind of auricular electro acupuncture, applied over a period of three days, can improve various aspects of quality of life significantly but also highlighted the significant increase of HRV whilst having acupuncture treatment. In conclusion, our study shows stimulation-related and quantifiable clinical and physiological alterations in parameters after continuous auricular acupoint stimulation in patients with depression. Improved access to electro acupuncture treatment would be of major benefit for these patients. Further studies are necessary in order to verify the gained results.

  8. Variability Study of the S5 Sample

    Indian Academy of Sciences (India)

    Jun Liu; Lang Cui; Xiang Liu; Zhen Ding; Hua-Gang Song

    2014-09-01

    We present the results of flux density monitoring of the S5 sample at 5GHz with the Urumqi 25-m radio telescope during Dec. 2008 and Nov. 2009. Most sources exhibited > 2% rms variation in our one-year monitoring. Twenty-five highly variable sources were detected at a confidence level of 99%. Weaker sources show larger amplitude of variability. Sources that have a steep spectral index are not as variable in flux density as the flat spectrum objects. No galactic dependent variability was found. Supplemental IDV observations for several strong variables were performed in order to search for possible rapid variability, and to compare variability on different time-scales. The absence of short time-scale variability in S5 0633+73 indicates that mid time-scale variability is a main source of intrinsic origin.

  9. Lake records of Northern Hemisphere South American summer monsoon variability from the Cordillera Oriental, Colombia: Initial results from Lago de Tota and Laguna de Ubaque

    Science.gov (United States)

    Escobar, J.; Rudloff, O.; Bird, B. W.

    2013-12-01

    The lack of terrestrial paleoclimate records from the Northern Hemisphere Andes with decadal resolution has meant that our understanding of abrupt South American summer monsoon (SASM) variability during the Holocene is almost exclusively based on data from Southern Hemisphere sites. In order to develop a more integrated and complete picture of the SASM as a system and its response during rapid climate changes, high-resolution paleoclimate records are needed from the Northern Hemisphere Andes. We present initial results from analysis of lake sediment cores that were collected from Lago de Tota (N 5.554, W 72.916) and Laguna de Ubaque (N 4.500, W 73.935) in the Eastern Cordillera of the Colombian Andes. These sediment cores were collected in July 2013 as part on an ongoing paleoclimate research initiative in Colombia. Located in the Boyacá Provence, Lago de Tota is the largest high-altitude lake (3010 masl) in the Northern Hemisphere Andes and the second largest Andean lake in South America. As such, hydrologic changes recorded in the lake's sediment record reflect regional climate responses. Lago de Ubaque (2070 masl) is a small east facing moraine-dammed lake near the capital of Bogotá that contains finely laminated clastic sediments. The initial sedimentological and chronological results demonstrate that Lago de Tota and Laguna de Ubaque have excellent potential for resolving Northern Hemisphere SASM variability at decadal time scales or better. Such records will provide important counterparts to high-resolution paleoclimate records from the Southern Hemisphere Andes.

  10. A Shriek From the Protomental System: Faint as a result of a failure in containing the group's latent dependency

    OpenAIRE

    2003-01-01

    One of Wilfred Bion's most original conceptsis the "protomental system" (PMS). This, which transcends clinical experience, he defined as a "hypothetical" place in human psyche where in the physical and the psychical are undifferentiated, and where in the non-operative basic assumptions are repressed as a result of aconspiracy between the dominant basic assumption group and the work group. According to the protomental system hypothesis, those repressed basic assumptions would form apsychosomat...

  11. Cosmological model dependence of the galaxy luminosity function: far-infrared results in the Lemaitre-Tolman-Bondi model

    CERN Document Server

    Iribarrem, A; Gruppioni, C; February, S; Ribeiro, M B; Berta, S; Floc'h, E Le; Magnelli, B; Nordon, R; Popesso, P; Pozzi, F; Riguccini, L

    2013-01-01

    This is the first paper of a series aiming at investigating galaxy formation and evolution in the giant-void class of the Lemaitre-Tolman-Bondi (LTB) models that best fits current cosmological observations. Here we investigate the Luminosity Function (LF) methodology, and how its estimates would be affected by a change on the cosmological model assumed in its computation. Are the current observational constraints on the allowed Cosmology enough to yield robust LF results? We use the far-infrared source catalogues built on the observations performed with the Herschel/PACS instrument, and selected as part of the PACS evolutionary probe (PEP) survey. Schechter profiles are obtained in redshift bins up to z approximately 4, assuming comoving volumes in both the standard model, that is, Friedmann-Lemaitre-Robertson-Walker metric with a perfect fluid energy-momentum tensor, and non-homogeneous LTB dust models, parametrized to fit the current combination of results stemming from the observations of supernovae Ia, th...

  12. Comparison of Computational and Experimental Results for a Transonic Variable-speed Power-Turbine Blade Operating with Low Inlet Turbulence Levels

    Science.gov (United States)

    Booth, David T.; Flegel, Ashlie B.

    2015-01-01

    A computational assessment of the aerodynamic performance of the midspan section of a variable-speed power-turbine blade is described. The computation comprises a periodic single blade that represents the 2-D Midspan section VSPT blade that was tested in the NASA Glenn Research Center Transonic Turbine Blade Cascade Facility. A commercial, off-the-shelf (COTS) software package, Pointwise and CFD++, was used for the grid generation and RANS and URANS computations. The CFD code, which offers flexibility in terms of turbulence and transition modeling options, was assessed in terms of blade loading, loss, and turning against test data from the transonic tunnel. Simulations were assessed at positive and negative incidence angles that represent the turbine cruise and take-off design conditions. The results indicate that the secondary flow induced at the positive incidence cruise condition results in a highly loaded case and transitional flow on the blade is observed. The negative incidence take-off condition is unloaded and the flow is very two-dimensional. The computational results demonstrate the predictive capability of the gridding technique and COTS software for a linear transonic turbine blade cascade with large incidence angle variation.

  13. The influence of variability of calculation grids on the results of numerical modeling of geothermal doublets - an example from the Choszczno area, north-western Poland

    Science.gov (United States)

    Wachowicz-Pyzik, A.; Sowiżdżał, A.; Pająk, L.

    2016-09-01

    The numerical modeling enables us to reduce the risk related to the selection of best localization of wells. Moreover, at the stage of production, modeling is a suitable tool for optimization of well operational parameters, which guarantees the long life of doublets. The thorough selection of software together with relevant methodology applied to generation of numerical models significantly improve the quality of obtained results. In the following paper, we discuss the impact of density of calculation grid on the results of geothermal doublet simulation with the TOUGH2 code, which applies the finite-difference method. The study area is located between the Szczecin Trough and the Fore-sudetic Monocline, where the Choszczno IG-1 well has been completed. Our research was divided into the two stages. At the first stage, we examined the changes of density of polygon calculation grids used in computations of operational parameters of geothermal doublets. At the second stage, we analyzed the influence of distance between the production and the injection wells on variability in time of operational parameters. The results demonstrated that in both studied cases, the largest differences occurred in pressures measured in production and injection wells whereas the differences in temperatures were less pronounced.

  14. Mouse strain-dependent caspase activation during acetaminophen hepatotoxicity does not result in apoptosis or modulation of inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Williams, C. David [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Koerner, Michael R., E-mail: mkoern2@illinois.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Lampe, Jed N. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Farhood, Anwar [Department of Pathology, Brackenridge Hospital, Austin, TX 78701 (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States)

    2011-12-15

    The mechanisms of acetaminophen (APAP)-mediated hepatic oncotic necrosis have been extensively characterized. However, it was recently demonstrated that fed CD-1 mice have a transient caspase activation which initiates apoptosis. To evaluate these findings in more detail, outbred (Swiss Webster, SW) and inbred (C57BL/6) mice were treated with APAP with or without pan-caspase inhibitor and compared to the apoptosis model of galactosamine (GalN)/endotoxin (ET). Fasted or fed APAP-treated C57BL/6 mice showed no evidence of caspase-3 processing or activity. Interestingly, a minor, temporary increase in caspase-3 processing and activity (150% above baseline) was observed after APAP treatment only in fed SW mice. The degree of caspase-3 activation in SW mice after APAP was minor compared to that observed in GalN/ET-treated mice (1600% above baseline). The pancaspase inhibitor attenuated caspase activation and resulted in increased APAP-induced injury (plasma ALT, necrosis scoring). The caspase inhibitor did not affect apoptosis because regardless of treatment only < 0.5% of hepatocytes showed consistent apoptotic morphology after APAP. In contrast, > 20% apoptotic cells were observed in GalN/ET-treated mice. Presence of the caspase inhibitor altered hepatic glutathione levels in SW mice, which could explain the exacerbation of injury. Additionally, the infiltration of hepatic neutrophils was not altered by the fed state of either mouse strain. Conclusion: Minor caspase-3 activation without apoptotic cell death can be observed only in fed mice of some outbred strains. These findings suggest that although the severity of APAP-induced liver injury varies between fed and fasted animals, the mechanism of cell death does not fundamentally change. -- Highlights: Black-Right-Pointing-Pointer During acetaminophen overdose caspase-3 can be activated in fed mice of certain outbred strains. Black-Right-Pointing-Pointer Hepatic ATP levels are not the determining factor for caspase

  15. Loss of Ercc1 Results in a Time- and Dose-Dependent Reduction of Proliferating Early Hematopoietic Progenitors

    Directory of Open Access Journals (Sweden)

    Judith H. E. Verhagen-Oldenampsen

    2012-01-01

    Full Text Available The endonuclease complex Ercc1/Xpf is involved in interstrand crosslink repair and functions downstream of the Fanconi pathway. Loss of Ercc1 causes hematopoietic defects similar to those seen in Fanconi Anemia. Ercc1−/− mice die 3-4 weeks after birth, which prevents long-term follow up of the hematopoietic compartment. We used alternative Ercc1 mouse models to examine the effect of low or absent Ercc1 activity on hematopoiesis. Tie2-Cre-driven deletion of a floxed Ercc1 allele was efficient (>80% in fetal liver hematopoietic cells. Hematopoietic stem and progenitor cells (HSPCs with a deleted allele were maintained in mice up to 1 year of age when harboring a wt allele, but were progressively outcompeted when the deleted allele was combined with a knockout allele. Mice with a minimal Ercc1 activity expressed by 1 or 2 hypomorphic Ercc1 alleles have an extended life expectancy, which allows analysis of HSPCs at 10 and 20 weeks of age. The HSPC compartment was affected in all Ercc1-deficient models. Actively proliferating multipotent progenitors were most affected as were myeloid and erythroid clonogenic progenitors. In conclusion, lack of Ercc1 results in a severe competitive disadvantage of HSPCs and is most deleterious in proliferating progenitor cells.

  16. Single-Lung Transplant Results in Position Dependent Changes in Regional Ventilation: An Observational Case Series Using Electrical Impedance Tomography

    Directory of Open Access Journals (Sweden)

    Kollengode Ramanathan

    2016-01-01

    Full Text Available Background. Lung transplantation is the optimal treatment for end stage lung disease. Donor shortage necessitates single-lung transplants (SLT, yet minimal data exists regarding regional ventilation in diseased versus transplanted lung measured by Electrical Impedance Tomography (EIT. Method. We aimed to determine regional ventilation in six SLT outpatients using EIT. We assessed end expiratory volume and tidal volumes. End expiratory lung impedance (EELI and Global Tidal Variation of Impedance were assessed in supine, right lateral, left lateral, sitting, and standing positions in transplanted and diseased lungs. A mixed model with random intercept per subject was used for statistical analysis. Results. EELI was significantly altered between diseased and transplanted lungs whilst lying on right and left side. One patient demonstrated pendelluft between lungs and was therefore excluded for further comparison of tidal variation. Tidal variation was significantly higher in the transplanted lung for the remaining five patients in all positions, except when lying on the right side. Conclusion. Ventilation to transplanted lung is better than diseased lung, especially in lateral positions. Positioning in patients with active unilateral lung pathologies will be implicated. This is the first study demonstrating changes in regional ventilation, associated with changes of position between transplanted and diseased lung.

  17. First Results from the HI Jodrell All Sky Survey Inclination-Dependent Selection Effects in a 21-cm Blind Survey

    CERN Document Server

    Lang, R H; Kilborn, V A; Minchin, R F; Disney, M J; Jordan, C A; Grossi, M; García, D A; Freeman, K C; Phillipps, S; Wright, A E

    2003-01-01

    Details are presented of the HI Jodrell All Sky Survey (HIJASS). HIJASS is a blind neutral hydrogen (HI) survey of the northern sky, being conducted using the multibeam receiver on the Lovell Telescope at Jodrell Bank. HIJASS covers the velocity range -3500 km/s to 10000 km/s with a velocity resolution of 18.1 km/s and a spatial positional accuracy of ~2.5 arcmin. Thus far about 1115 sq deg have been surveyed. We describe the methods of detecting galaxies within the HIJASS data and of measuring their HI parameters. The properties of the resulting HI-selected sample of galaxies are described. Of the 222 sources so far confirmed, 170 (77 per cent) are clearly associated with a previously catalogued galaxy. A further 23 sources (10 percent) lie close (within 6 arcmin) to a previously catalogued galaxy for which no previous redshift exists. A further 29 sources (13 per cent) do not appear to be associated with any previously catalogued galaxy. The distributions of peak flux, integrated flux, HI mass and cz are di...

  18. CHARACTERISTICS OF TREATMENT OF PATIENTS WITH ACUTE AND CHRONIC LARYNGITIS DEPENDING ON RESULTS OF BACTERIOLOGICAL EXAMINATION OF LARYNX MICROFLORA

    Directory of Open Access Journals (Sweden)

    K. I. Chuikova

    2014-01-01

    Full Text Available This paper describes study of larynx microflora in patients with acute laryngtis and exacerbations of chronic laryngitis. Therapeutic algorithm based on bacteriologic examination data was developed reduce. New algorithm helps reduce sickness terms and to decrease prevalence of desease.123 patients of age from 18 to 60 were under observation: 43 patients with acute laryngitis and 80 patients with exacerbation of chronic laryngitis. 22 patients with acute laryngitis and 58 patients with exacerbation of chronic laryngitis underwent etiotropic treatment with antibiotics. The group of comparison with acute laryngitis (21 patients and chronic laryngitis (22 patients received treatment according to the conventional scheme.Bacteriologic examination of larynx mucous, clinical study and functional voice test (time of maximum vowels phonation before and after treatment were carried out.As a result of the research it was established that the most common causative agent of acute and chronic inflammatory larynx diseases is S. aureus as a mono culture or combined with other bacterial associations (S. аnhemolyticus, Str. viridans etc..After the end of antibacterial therapy we found symptoms as hoarseness, irritation, dry laryngopharynx, hyperemia and swelling of larynx mucous reduced eather in new treatment group than controlled group. Time of maximum vowels phonation (in seconds also increased significantly.Sickness terms after prescription of new treatment was shorter than in comparison groups: (10.9 ± 7.9 days for acute laryngitis and (12.6 ± 7.3 days for chronic laryngitis respectively. Health index was 20.8 and 19.5% respectively.

  19. Successful pod infections by Moniliophthora roreri result in differential Theobroma cacao gene expression depending on the clone's level of tolerance.

    Science.gov (United States)

    Ali, Shahin S; Melnick, Rachel L; Crozier, Jayne; Phillips-Mora, Wilberth; Strem, Mary D; Shao, Jonathan; Zhang, Dapeng; Sicher, Richard; Meinhardt, Lyndel; Bailey, Bryan A

    2014-09-01

    An understanding of the tolerance mechanisms of Theobroma cacao used against Moniliophthora roreri, the causal agent of frosty pod rot, is important for the generation of stable disease-tolerant clones. A comparative view was obtained of transcript populations of infected pods from two susceptible and two tolerant clones using RNA sequence (RNA-Seq) analysis. A total of 3009 transcripts showed differential expression among clones. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis of differentially expressed genes indicated shifts in 152 different metabolic pathways between the tolerant and susceptible clones. Real-time quantitative reverse transcription polymerase chain reaction (real-time qRT-PCR) analyses of 36 genes verified the differential expression. Regression analysis validated a uniform progression in gene expression in association with infection levels and fungal loads in the susceptible clones. Expression patterns observed in the susceptible clones diverged in tolerant clones, with many genes showing higher expression at a low level of infection and fungal load. Principal coordinate analyses of real-time qRT-PCR data separated the gene expression patterns between susceptible and tolerant clones for pods showing malformation. Although some genes were constitutively differentially expressed between clones, most results suggested that defence responses were induced at low fungal load in the tolerant clones. Several elicitor-responsive genes were highly expressed in tolerant clones, suggesting rapid recognition of the pathogen and induction of defence genes. Expression patterns suggested that the jasmonic acid-ethylene- and/or salicylic acid-mediated defence pathways were activated in the tolerant clones, being enhanced by reduced brassinosteroid (BR) biosynthesis and catabolic inactivation of both BR and abscisic acids. Finally, several genes associated with hypersensitive response-like cell death were also induced in tolerant clones. © 2014

  20. Differences in onset and abuse/dependence episodes between prescription opioids and heroin: results from the National Epidemiologic Survey on Alcohol and Related Conditions

    Directory of Open Access Journals (Sweden)

    Mannelli P

    2011-05-01

    Full Text Available Li-Tzy Wu1, George E Woody2, Chongming Yang3, Paolo Mannelli1, Dan G Blazer11Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Duke University Medical Center, Durham, NC, USA; 2Department of Psychiatry, University of Pennsylvania School of Medicine, University of Pennsylvania and Treatment Research Institute, Philadelphia, PA, USA; 3Social Science Research Institute, Duke University, Durham, NC, USAObjectives: To examine patterns of onset and abuse/dependence episodes of prescription opioid (PO and heroin use disorders in a national sample of adults, and to explore differences by gender and substance abuse treatment status.Methods: Analyses of data from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (N = 43,093.Results: Of all respondents, 5% (n = 1815 reported a history of nonmedical PO use (NMPOU and 0.3% (n = 150 a history of heroin use. Abuse was more prevalent than dependence among NMPOUs (PO abuse, 29%; dependence, 7% and heroin users (heroin abuse, 63%; dependence, 28%. Heroin users reported a short mean interval from first use to onset of abuse (1.5 years or dependence (2.0 years, and a lengthy mean duration for the longest episode of abuse (66 months or dependence (59 months; the corresponding mean estimates for PO abuse and dependence among NMPOUs were 2.6 and 2.9 years, respectively, and 31 and 49 months, respectively. The mean number of years from first use to remission from the most recent episode was 6.9 years for PO abuse and 8.1 years for dependence; the mean number of years from first heroin use to remission from the most recent episode was 8.5 years for heroin abuse and 9.7 years for dependence. Most individuals with PO or heroin use disorders were remitted from the most recent episode. Treated individuals, whether their problem was heroin or POs, tended to have a longer mean duration of an episode than untreated individuals.Conclusion: Periodic remissions

  1. Temporal Variability and Annual Fluxes of Water, Sediment and Particulate Phosphorus from a Headwater River in the Tropical Andes: Results from a High-frequency Monitoring Program

    Science.gov (United States)

    Wemple, B. C.; Schloegel, C.

    2015-12-01

    The Mazar River Project, a high-frequency hydrological monitoring program, aims to generate ecohydrological information to inform watershed management in high-mountain areas of southern Ecuador. Rapid development of hydropower, accompanied by new and improved road networks, has resulted in swift changes in land-use and land cover in Ecuador's tropical Andes, all of which underscore the need for detailed information on flow and sediment production from these river systems. National and regional payment for the protection of ecosystem services (PES) programs seek to target critical areas, such as these, for watershed conservation, but are often informed by minimal information on sustainable flows and impacts of land use activities. As part of a program to inform conservation and sustainable water management in the region, we established a hydrological monitoring station in southern Ecuador on the Mazar River, a tributary of the Paute River Basin, situated on the eastern Andean cordillera. The station is equipped with sensors to continuously monitor stream stage and turbidity and an automated sampler for event-based collection of stream water samples, providing high frequency data that reduces the uncertainty of observations. Here, we report observations of continuous runoff and turbidity over the first year of observation, present relationships between turbidity and concentrations of total suspended solids (TSS) and total particulate phosphorus (TP), and provide estimates of annual loads of TSS and TP. Runoff was highly variable over the monitoring period with flows ranging from less than 3 m3/s during baseflow to nearly 80 m3/s during the flood of record. During measured storm events, TSS exceeded 1000 mg/l with maximum measured concentrations exceeding 13 g/l during storm peaks. Turbidity was highly correlated with TSS, which was in turn highly correlated with TP, providing a robust data set for load estimation. We compare our results to other montane rivers in the

  2. First results of Indian - Current meter moorings along The equator: Vertical current structure variability at equator, 93 degrees E during February-December, 2000

    Digital Repository Service at National Institute of Oceanography (India)

    Murty, V.S.N.; Suryanarayana, A.; Sarma, M.S.S.; Tilvi, V.; Fernando, V.; Nampoothiri, G.; Sardar, A.; Gracias, D.; Khalap, S.

    are weak while the low pass filtered (49-hour) current data show considerable meso-scale variability, comprising of Intraseasonal Oscillations (ISO) of period 10-20 day and 40.5 day. The 10-20 day ISO is associated with similar variability in surface wind...

  3. Variability in the diagnosis and management of patients with Alzheimer's disease and cerebrovascular disease: results from the GALATEA multicentre, observational study.

    Science.gov (United States)

    Gil, Pedro; Ayuso, José Luis Dobato; Marey, José Manuel; Antón, Manuel; Quilo, Carlos Guzmán

    2008-01-01

    There is frequently a degree of variability among different types of dementia specialists in clinical practice in both the clinical diagnosis and the management of patients with Alzheimer's disease and cerebrovascular disease (CVD). This variability may have an adverse effect on the use of medical resources as well as on patients' well-being. The main objective of this study was to describe the current diagnosis and management of patients with Alzheimer's disease and CVD in Spain. Other objectives were to determine whether there were significant differences in the diagnosis and management of these patients depending on physician characteristics and/or patient profile. This was an epidemiological, cross-sectional, multicentre study in which 107 physicians participated and recruited patients with Alzheimer's disease and CVD. During a 1-month period, physicians collected data on diagnosis, treatment, follow-up, adverse events and other characteristics of these patients. This study was performed under naturalistic conditions, and no restrictions were imposed on the physicians. Physicians were mainly neurologists (76%), geriatricians (14%) and psychiatrists (8%) with a median age of 42 years. A total of 720 patients with a diagnosis of Alzheimer's disease and CVD were recruited. The median age of the patients was 78 years. Almost all patients were diagnosed by neuroimaging (98%) together with medical history (87%). The existence of a previous stroke coincident with cognitive deterioration was used as a diagnostic method in only 27% of patients. Among non-pharmacological treatment measures, diet was the most frequently recommended (61%), followed by cognitive stimulation (50%) and physical exercise (44%). The most commonly used pharmacological treatments were galantamine (59%), donepezil (14%) and rivastigmine (11%). The incidence of adverse events was low (3%), and all were considered non-severe. There were no significant correlations between physician age or physician

  4. Lower limbs valvular insufficiency diagnosed by color-doppler US: variability in the results using the standing or semi-Fowler position and Valsalva maneuver or distal compression

    Directory of Open Access Journals (Sweden)

    Federico Guillermo Lubinus Badillo

    2007-05-01

    Full Text Available Objectives: To determine differences in diagnosis of valvular insufficiency by color doppler ultrasonography in standing or semi-Fowler position and Valsalva maneuver or distal compression. Methodology:98 patients with 1-3 degreee valvular insufficiency were studiedAll of thew were evaluated by doppler ultrasonography in boothpositions and maneuvers. Results: There were differences betweenthe different techniques. In upper segments, a higher frequency of reflux was found with semi-Fowler plus Valsalva´s maneuver; in intermediate segments there were similar reflux prevalences using both positions; and, in lower segments, there was more reflux using standing position plus Valsalva´s maneuver. Conclusion. Depending on the venous group to evaluate, it is necessary to adapt the evaluation technique used with Doppler ultrasound color test.

  5. Dynamical Opacity-Sampling Models of Mira Variables. II: Time-Dependent Atmospheric Structure and Observable Properties of 4 M-Type Model Series

    CERN Document Server

    Ireland, Michael J; Wood, Peter R

    2011-01-01

    We present 4 model series of the CODEX dynamical opacity-sampling models of Mira variables with solar abundances, designed to have parameters similar to $o$ Cet, R Leo and R Cas. We demonstrate that the CODEX models provide a clear physical basis for the molecular shell scenario used to explain interferometric observations of Mira variables. We show that these models generally provide a good match to photometry and interferometry at wavelengths between the near-infrared and the radio, and make the model outputs publicly available. These model also demonstrate that, in order to match visible and infrared observations, the Fe-poor silicate grains that form within 3 continuum radii must have small grain radii and therefore can not drive the winds from O-rich Mira variables.

  6. Index for Wind Power Variability

    Energy Technology Data Exchange (ETDEWEB)

    Kiviluoma, Juha; Holttinen, Hannele; Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Scharff, Richard; Milligan, Michael; Weir, David Edward

    2014-11-13

    Variability of large scale wind power generation is dependent on several factors: characteristics of installed wind power plants, size of the area where the plants are installed, geographic dispersion within that area and its weather regime(s). Variability can be described by ramps in power generation, i.e. changes from time period to time period. Given enough data points, it can be described with a probability density function. This approach focuses on two dimensions of variability: duration of the ramp and probability distribution. This paper proposes an index based on these two dimensions to enable comparisons and characterizations of variability under different conditions. The index is tested with real, large scale wind power generation data from several countries. Considerations while forming an index are discussed, as well as the main results regarding what the drivers of variability experienced for different data.

  7. Integrating Standard Dependency Schemes in QCSP Solvers

    Institute of Scientific and Technical Information of China (English)

    Ji-Wei Jin; Fei-Fei Ma; Jian Zhang

    2012-01-01

    Quantified constraint satisfaction problems (QCSPs) are an extension to constraint satisfaction problems (CSPs) with both universal quantifiers and existential quantifiers.In this paper we apply variable ordering heuristics and integrate standard dependency schemes in QCSP solvers.The technique can help to decide the next variable to be assigned in QCSP solving.We also introduce a new factor into the variable ordering heuristics:a variable's dep is the number of variables depending on it.This factor represents the probability of getting more candidates for the next variable to be assigned.Experimental results show that variable ordering heuristics with standard dependency schemes and the new factor dep can improve the performance of QCSP solvers.

  8. StralSV: assessment of sequence variability within similar 3D structures and application to polio RNA-dependent RNA polymerase

    Energy Technology Data Exchange (ETDEWEB)

    Zemla, A; Lang, D; Kostova, T; Andino, R; Zhou, C

    2010-11-29

    Most of the currently used methods for protein function prediction rely on sequence-based comparisons between a query protein and those for which a functional annotation is provided. A serious limitation of sequence similarity-based approaches for identifying residue conservation among proteins is the low confidence in assigning residue-residue correspondences among proteins when the level of sequence identity between the compared proteins is poor. Multiple sequence alignment methods are more satisfactory - still, they cannot provide reliable results at low levels of sequence identity. Our goal in the current work was to develop an algorithm that could overcome these difficulties and facilitate the identification of structurally (and possibly functionally) relevant residue-residue correspondences between compared protein structures. Here we present StralSV, a new algorithm for detecting closely related structure fragments and quantifying residue frequency from tight local structure alignments. We apply StralSV in a study of the RNA-dependent RNA polymerase of poliovirus and demonstrate that the algorithm can be used to determine regions of the protein that are relatively unique or that shared structural similarity with structures that are distantly related. By quantifying residue frequencies among many residue-residue pairs extracted from local alignments, one can infer potential structural or functional importance of specific residues that are determined to be highly conserved or that deviate from a consensus. We further demonstrate that considerable detailed structural and phylogenetic information can be derived from StralSV analyses. StralSV is a new structure-based algorithm for identifying and aligning structure fragments that have similarity to a reference protein. StralSV analysis can be used to quantify residue-residue correspondences and identify residues that may be of particular structural or functional importance, as well as unusual or unexpected

  9. Genetic homogeneity but IgG subclass-dependent clinical variability of alloimmune membranous nephropathy with anti-neutral endopeptidase antibodies.

    Science.gov (United States)

    Vivarelli, Marina; Emma, Francesco; Pellé, Thimothée; Gerken, Christopher; Pedicelli, Stefania; Diomedi-Camassei, Francesca; Klaus, Günter; Waldegger, Siegfried; Ronco, Pierre; Debiec, Hanna

    2015-03-01

    Alloimmune antenatal membranous nephropathy (MN) during pregnancy results from antibodies produced by a neutral endopeptidase (NEP)-deficient mother. Here we report two recent cases that provide clues to the severity of renal disease. Mothers of the two children had circulating antibodies against NEP showing the characteristic species-dependent pattern by immunofluorescence on kidney slices. A German mother produced predominantly anti-NEP IgG4 accompanied by a low amount of IgG1. Her child recovered renal function within a few weeks. In sharp contrast, an Italian mother mainly produced complement-fixing anti-NEP IgG1, which also inhibits NEP enzymatic activity, whereas anti-NEP IgG4 has a weak inhibitory potency. Her child was dialyzed for several weeks. A kidney biopsy performed at 12 days of age showed MN, ischemic glomeruli, and arteriolar and tubular lesions. A second biopsy performed at 12 weeks of age showed aggravation with an increased number of collapsed capillary tufts. Both mothers were homozygous for the truncating deletion mutation 466delC and were thus NEP deficient. The 466delC mutation, identified in three previously described families, suggests a founder effect. Because of the potential severity of alloimmune antenatal MN, it is essential to identify families at risk by the detection of anti-NEP antibodies and NEP antigen in urine. On the basis of the five families identified to date, we propose an algorithm for the diagnosis of the disease and the prevention of complications.

  10. Dependence of the atomic level Green-Kubo stress correlation function on wavevector and frequency: molecular dynamics results from a model liquid.

    Science.gov (United States)

    Levashov, V A

    2014-09-28

    We report on a further investigation of a new method that can be used to address vibrational dynamics and propagation of stress waves in liquids. The method is based on the decomposition of the macroscopic Green-Kubo stress correlation function into the atomic level stress correlation functions. This decomposition, as was demonstrated previously for a model liquid studied in molecular dynamics simulations, reveals the presence of stress waves propagating over large distances and a structure that resembles the pair density function. In this paper, by performing the Fourier transforms of the atomic level stress correlation functions, we elucidate how the lifetimes of the stress waves and the ranges of their propagation depend on their frequency, wavevector, and temperature. These results relate frequency and wavevector dependence of the generalized viscosity to the character of propagation of the shear stress waves. In particular, the results suggest that an increase in the value of the frequency dependent viscosity at low frequencies with decrease of temperature is related to the increase in the ranges of propagation of the stress waves of the corresponding low frequencies. We found that the ranges of propagation of the shear stress waves of frequencies less than half of the Einstein frequency extend well beyond the nearest neighbor shell even above the melting temperature. The results also show that the crossover from quasilocalized to propagating behavior occurs at frequencies usually associated with the Boson peak.

  11. The effects of weight loss and salt reduction on visit-to-visit blood pressure variability: results from a multicenter randomized controlled trial.

    Science.gov (United States)

    Diaz, Keith M; Muntner, Paul; Levitan, Emily B; Brown, Michael D; Babbitt, Dianne M; Shimbo, Daichi

    2014-04-01

    As evidence suggests visit-to-visit variability (VVV) of blood pressure (BP) is associated with cardiovascular events and mortality, there is increasing interest in identifying interventions that reduce VVV of BP. We investigated the effects of weight loss and sodium reduction, alone or in combination, on VVV of BP in participants enrolled in phase II of the Trials of Hypertension Prevention. BP readings were taken at 6-month intervals for 36 months in 1820 participants with high-normal DBP who were randomized to weight loss, sodium reduction, combination (weight loss and sodium reduction), or usual care groups. VVV of BP was defined as the SD of BP across six follow-up visits. VVV of SBP was not significantly different between participants randomized to the weight loss (7.2 ± 3.1  mmHg), sodium reduction (7.1 ± 3.0  mmHg), or combined (6.9 ± 2.9  mmHg) intervention groups vs. the usual care group (6.9 ± 2.9  mmHg). In a fully adjusted model, no difference (0.0 ± 0.2  mmHg) in VVV of SBP was present between individuals who successfully maintained their weight loss vs. individuals who did not lose weight during follow-up (P = 0.93). Also, those who maintained a reduced sodium intake throughout follow-up did not have lower VVV of SBP compared to those who did not reduce their sodium intake (0.1 ± 0.3  mmHg; P = 0.77). Results were similar for VVV of DBP. These findings suggest that weight loss and sodium reduction may not be effective interventions for lowering VVV of BP in individuals with high-normal DBP.

  12. VERTICAL ATMOSPHERIC STRUCTURE IN A VARIABLE BROWN DWARF: PRESSURE-DEPENDENT PHASE SHIFTS IN SIMULTANEOUS HUBBLE SPACE TELESCOPE-SPITZER LIGHT CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Buenzli, Esther; Apai, Daniel; Flateau, Davin [Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Morley, Caroline V. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA 95060 (United States); Showman, Adam P.; Lewis, Nikole K. [Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Marley, Mark S. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Reid, I. Neill, E-mail: ebuenzli@email.arizona.edu [Space Telescope Science Institute, Baltimore, MD 21218 (United States)

    2012-12-01

    Heterogeneous clouds or temperature perturbations in rotating brown dwarfs produce variability in the observed flux. We report time-resolved simultaneous observations of the variable T6.5 brown dwarf 2MASS J22282889-431026 over the wavelength ranges 1.1-1.7 {mu}m and broadband 4.5 {mu}m. Spectroscopic observations were taken with Wide Field Camera 3 on board the Hubble Space Telescope and photometry with the Spitzer Space Telescope. The object shows sinusoidal infrared variability with a period of 1.4 hr at most wavelengths with peak-to-peak amplitudes between 1.45% and 5.3% of the mean flux. While the light curve shapes are similar at all wavelengths, their phases differ from wavelength to wavelength with a maximum difference of more than half of a rotational period. We compare the spectra with atmospheric models of different cloud prescriptions, from which we determine the pressure levels probed at different wavelengths. We find that the phase lag increases with decreasing pressure level, or higher altitude. We discuss a number of plausible scenarios that could cause this trend of light curve phase with probed pressure level. These observations are the first to probe heterogeneity in an ultracool atmosphere in both horizontal and vertical directions, and thus are an ideal test case for realistic three-dimensional simulations of the atmospheric structure with clouds in brown dwarfs and extrasolar planets.

  13. A VL-linker-VH Orientation Dependent Single Chain Variable Antibody Fragment Against Rabies Virus G Protein with Enhanced Neutralizing Potency in vivo.

    Science.gov (United States)

    Cheng, Yue; Li, Zhuang; Xi, Hualong; Gu, Tiejun; Yuan, Ruosen; Chen, Xiaoxu; Jiang, Chunlai; Kong, Wei; Wu, Yongge

    2016-01-01

    Lethal rabies can be prevented effectively by post-exposure prophylactic (PEP) with rabies immunoglobulin (RIG). Single-chain variable fragment (scFv), which is composed of a variable heavy chain (VH) and variable light chain (VL) connected by a peptide linker, may be developed as alternative to RIG for neutralizing rabies virus (RV). However, our previously constructed scFv (FV57S) with the (NH2) VH-linker-VL (COOH) orientation showed a lower neutralizing potency than its parent RIG. This orientation may inhibit FV57S from refolding into an intact and correct conformation. Therefore, the RFV57S protein with a VL-linker-VH orientation was constructed based on FV57S. A HIS tag was incorporated to aid in purification and detection of RFV57S and FV57S. However, abilities of RFV57S and FV57S to bind with the anti-HIS tag mAb were different. Therefore, a novel direct ELISA was established by utilizing a biotin-labeled truncated glycoprotein of RV. Although with similar stability and in vitro neutralizing potency as FV57S, RFV57S showed enhanced binding ability, affinity and in vivo protective efficacy against lethal dose of RV. Our studies support the feasibility of developing a scFv with reversed orientation and provide a novel method for evaluating the binding ability, stability and affinity of engineered antibodies recognizing linear epitope.

  14. Time- and state-dependent analysis of autonomic control in narcolepsy: higher heart rate with normal heart rate variability independent of sleep fragmentation.

    Science.gov (United States)

    van der Meijden, Wisse P; Fronczek, Rolf; Reijntjes, Robert H A M; Corssmit, Eleonora P M; Biermasz, Nienke R; Lammers, Gert Jan; van Dijk, J Gert; Thijs, Roland D

    2015-04-01

    Narcolepsy with hypocretin deficiency is known to alter cardiovascular control during sleep, but its aetiology is disputed. As cardiovascular control differs between sleep states, and narcolepsy affects sleep architecture, controlling for both duration and transitions of sleep states is necessary. This study therefore aimed to assess heart rate and its variability in narcolepsy during sleep taking these factors into account. The study included 12 medication-naïve patients with narcolepsy with cataplexy and hypocretin deficiency (11 male, 16-53 years old), and 12 sex- and age-matched healthy controls (11 male, 19-55 years). All subjects underwent 1-night ambulatory polysomnography recording. Cardiovascular parameters were calculated for each 30-s epoch. Heart rate was significantly higher in patients with narcolepsy than in controls in all sleep states and during wakefulness prior to sleep. Groups did not differ in heart rate variability measures. The effects of sleep state duration on heart rate and its variability were similar between patients and controls. In conclusion, heart rate was consistently higher in patients with narcolepsy than controls, independent of sleep stage and sleep fragmentation. A direct effect of hypocretin deficiency therefore seems probable.

  15. First measurement of the small-scale spatial variability of the rain drop size distribution: Results from a crucial experiment and maximum entropy modeling

    CERN Document Server

    Checa-Garcia, Ramiro

    2013-01-01

    The main challenges of measuring precipitation are related to the spatio-temporal variability of the drop-size distribution, to the uncertainties that condition the modeling of that distribution, and to the instrumental errors present in the in situ estimations. This PhD dissertation proposes advances in all these questions. The relevance of the spatial variability of the drop-size distribution for remote sensing measurements and hydro-meteorology field studies is asserted by analyzing the measurement of a set of disdrometers deployed on a network of 5 squared kilometers. This study comprises the spatial variability of integral rainfall parameters, the ZR relationships, and the variations within the one moment scaling method. The modeling of the drop-size distribution is analyzed by applying the MaxEnt method and comparing it with the methods of moments and the maximum likelihood. The instrumental errors are analyzed with a compressive comparison of sampling and binning uncertainties that affect actual device...

  16. VARIABILITY IN LEVELS OF LOW-DENSITY LIPOPROTEINS CHOLESTEROL IN PATIENTS WITH FAMILIAL HYPERCHOLESTEROLEMIA DEPENDING ON AGE AND SEX AND ITS IMPORTANCE IN THE DIAGNOSIS OF THIS DISEASE

    Directory of Open Access Journals (Sweden)

    V. А. Korneva

    2017-01-01

    Full Text Available Aim. To study the ranges of low density lipoprotein (LDL cholesterol depending on the age and gender of patients with familial hypercholesterolemia (FHC by an example of a sample of patients living in the Republic of Karelia.Material and methods. Parameters of lipid spectrum of 219 patients (aged 52.5±1.7 years; males 38.3% with heterozygous FHC were studied before the start of statin therapy. Definite FHC was diagnosed in 102 patients. Lipid profile was estimated by enzymatic calorimetric method. The diagnosis of FHC was established according to the criteria of The Dutch Lipid Clinic Network.  Genetic analysis was performed in 102 patients (46.6%; pathogenic mutation in the LDL receptor was identified in 21 patients. The control group consisted of 539 people with the excluded diagnosis of FHC (aged 46.8±0.8 years; males 53.8%.Results. We determined the level of LDL cholesterol (LDLC associated with increased frequency of mutations of the LDL receptor in patients with definite FHC; mutation frequency was 3 times higher when LDLC level was more than 6.5 mmol/L. We revealed the following characteristic intervals of the LDLC levels in patients with a definite FHC: up to 20 years old – 4.8-6.2 mmol/l; in patients of 20-29 years old – 5.9-8.2 mmol/l; in the age range of 30-39 years the upper value of the LDLC levels reached 9.6 mmol/l; in individuals of 40-49 years old a stabilization, "plateau", was observed – LDLC level did not differ significantly compared to the previous decade, and was 5.4-9.0 mmol/l. In the age range  of 50-59 years the upper LDLC level was up to 11.4 mmol/l. Similar indicators were identified in patients aged 60-69 years. Patients older than 70 years with a definite FHC an upper level of LDLC was higher and reached 12.5 mmol/l. Tendency to increase in the characteristic values of LDLC with age was observed both in men and in women. Specific age-related trends  for men (an increase from a plateau by the age of 50

  17. The global epidemiology and contribution of cannabis use and dependence to the global burden of disease: results from the GBD 2010 study.

    Directory of Open Access Journals (Sweden)

    Louisa Degenhardt

    Full Text Available AIMS: Estimate the prevalence of cannabis dependence and its contribution to the global burden of disease. METHODS: Systematic reviews of epidemiological data on cannabis dependence (1990-2008 were conducted in line with PRISMA and meta-analysis of Observational Studies in Epidemiology (MOOSE guidelines. Culling and data extraction followed protocols, with cross-checking and consistency checks. DisMod-MR, the latest version of generic disease modelling system, redesigned as a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. The disability weight associated with cannabis dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs and disability-adjusted life years (DALYs. YLDs and DALYs attributed to regular cannabis use as a risk factor for schizophrenia were also estimated. RESULTS: There were an estimated 13.1 million cannabis dependent people globally in 2010 (point prevalence0.19% (95% uncertainty: 0.17-0.21%. Prevalence peaked between 20-24 yrs, was higher in males (0.23% (0.2-0.27% than females (0.14% (0.12-0.16% and in high income regions. Cannabis dependence accounted for 2 million DALYs globally (0.08%; 0.05-0.12% in 2010; a 22% increase in crude DALYs since 1990 largely due to population growth. Countries with statistically higher age-standardised DALY rates included the United States, Canada, Australia, New Zealand and Western European countries such as the United Kingdom; those with lower DALY rates were from Sub-Saharan Africa-West and Latin America. Regular cannabis use as a risk factor for schizophrenia accounted for an estimated 7,000 DALYs globally. CONCLUSION: Cannabis dependence is a disorder primarily experienced by young adults, especially in higher income countries. It has not been shown to increase mortality as opioid and other forms of illicit drug dependence do. Our estimates

  18. The Global Epidemiology and Contribution of Cannabis Use and Dependence to the Global Burden of Disease: Results from the GBD 2010 Study

    Science.gov (United States)

    Degenhardt, Louisa; Ferrari, Alize J.; Calabria, Bianca; Hall, Wayne D.; Norman, Rosana E.; McGrath, John; Flaxman, Abraham D.; Engell, Rebecca E.; Freedman, Greg D.; Whiteford, Harvey A.; Vos, Theo

    2013-01-01

    Aims Estimate the prevalence of cannabis dependence and its contribution to the global burden of disease. Methods Systematic reviews of epidemiological data on cannabis dependence (1990-2008) were conducted in line with PRISMA and meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines. Culling and data extraction followed protocols, with cross-checking and consistency checks. DisMod-MR, the latest version of generic disease modelling system, redesigned as a Bayesian meta-regression tool, imputed prevalence by age, year and sex for 187 countries and 21 regions. The disability weight associated with cannabis dependence was estimated through population surveys and multiplied by prevalence data to calculate the years of life lived with disability (YLDs) and disability-adjusted life years (DALYs). YLDs and DALYs attributed to regular cannabis use as a risk factor for schizophrenia were also estimated. Results There were an estimated 13.1 million cannabis dependent people globally in 2010 (point prevalence0.19% (95% uncertainty: 0.17-0.21%)). Prevalence peaked between 20-24 yrs, was higher in males (0.23% (0.2-0.27%)) than females (0.14% (0.12-0.16%)) and in high income regions. Cannabis dependence accounted for 2 million DALYs globally (0.08%; 0.05-0.12%) in 2010; a 22% increase in crude DALYs since 1990 largely due to population growth. Countries with statistically higher age-standardised DALY rates included the United States, Canada, Australia, New Zealand and Western European countries such as the United Kingdom; those with lower DALY rates were from Sub-Saharan Africa-West and Latin America. Regular cannabis use as a risk factor for schizophrenia accounted for an estimated 7,000 DALYs globally. Conclusion Cannabis dependence is a disorder primarily experienced by young adults, especially in higher income countries. It has not been shown to increase mortality as opioid and other forms of illicit drug dependence do. Our estimates suggest that

  19. The nonmonotonic concentration dependence of the mean activity coefficient of electrolytes is a result of a balance between solvation and ion-ion correlations.

    Science.gov (United States)

    Vincze, Julianna; Valiskó, Mónika; Boda, Dezso

    2010-10-21

    We propose a simple model to explain the nonmonotonic concentration dependence of the mean activity coefficient of simple electrolytes without using any adjustable parameters. The primitive model of electrolytes is used to describe the interaction between ions computed by the adaptive grand canonical Monte Carlo method. For the dielectric constant of the electrolyte, we use experimental concentration dependent values. This is included through a solvation term in our treatment to describe the interaction between ions and water that changes as the dielectric constant changes with concentration. This term is computed by a Born-treatment fitted to experimental hydration energies. Our results for LiCl, NaCl, KCl, CsCl, NaBr, NaI, MgCl(2), CaCl(2), SrCl(2), and BaCl(2) demonstrate that the principal reason of the nonmonotonic behavior of the activity coefficient is a balance between the solvation and ion-ion correlation terms. This conclusion differs from previous studies that assumed that it is the balance of hard sphere repulsion and electrostatic attraction that produces the nonmonotonic behavior. Our results indicate that the earlier assumption that solvation can be taken into account by a larger, "solvated" ionic radius should be reconsidered. To explain second order effects (such as dependence on ionic size), we conclude that explicit water models are needed.

  20. Applying the Transactional Stress and Coping Model to Sickle Cell Disorder and Insulin-Dependent Diabetes Mellitus: Identifying Psychosocial Variables Related to Adjustment and Intervention

    Science.gov (United States)

    Hocking, Matthew C.; Lochman, John E.

    2005-01-01

    This review paper examines the literature on psychosocial factors associated with adjustment to sickle cell disease and insulin-dependent diabetes mellitus in children through the framework of the transactional stress and coping (TSC) model. The transactional stress and coping model views adaptation to a childhood chronic illness as mediated by…

  1. The influence of basic design variables on the acoustics of concert halls; new results derived from analysing a large number of existing halls

    DEFF Research Database (Denmark)

    Gade, Anders Christian

    1997-01-01

    , it has been possible to derive empirical regression formulae from which the influence of certain geometrical design variables can be quantified. The author has found these fairly simple relationships useful in teaching and as guide lines both in the early stages of physical hall design and in setting up...

  2. Resonant vibrations resulting from the re-engineering of a constant-speed 2-bladed turbine to a variable-speed 3-bladed turbine

    NARCIS (Netherlands)

    Fleming, P.A.; Wright, A.D.; Fingersh, L.J.; Van Wingerden, J.W.

    2011-01-01

    The CART3 (Controls Advanced Research Turbine, 3-bladed) at the National Wind Technology Center has recently been converted from a 2-bladed constant speed machine to a 3-bladed variable speed machine designed specifically for controls research. The purpose of this conversion was to develop an advanc

  3. High-resolution delineation of chlorinated volatile organic compounds in a dipping, fractured mudstone: Depth- and strata-dependent spatial variability from rock-core sampling.

    Science.gov (United States)

    Goode, Daniel J; Imbrigiotta, Thomas E; Lacombe, Pierre J

    2014-12-15

    Synthesis of rock-core sampling and chlorinated volatile organic compound (CVOC) analysis at five coreholes, with hydraulic and water-quality monitoring and a detailed hydrogeologic framework, was used to characterize the fine-scale distribution of CVOCs in dipping, fractured mudstones of the Lockatong Formation of Triassic age, of the Newark Basin in West Trenton, New Jersey. From these results, a refined conceptual model for more than 55years of migration of CVOCs and depth- and strata-dependent rock-matrix contamination was developed. Industrial use of trichloroethene (TCE) at the former Naval Air Warfare Center (NAWC) from 1953 to 1995 resulted in dense non-aqueous phase liquid (DNAPL) TCE and dissolved TCE and related breakdown products, including other CVOCs, in underlying mudstones. Shallow highly weathered and fractured strata overlie unweathered, gently dipping, fractured strata that become progressively less fractured with depth. The unweathered lithology includes black highly fractured (fissile) carbon-rich strata, gray mildly fractured thinly layered (laminated) strata, and light-gray weakly fractured massive strata. CVOC concentrations in water samples pumped from the shallow weathered and highly fractured strata remain elevated near residual DNAPL TCE, but dilution by uncontaminated recharge, and other natural and engineered attenuation processes, have substantially reduced concentrations along flow paths removed from sources and residual DNAPL. CVOCs also were detected in most rock-core samples in source areas in shallow wells. In many locations, lower aqueous concentrations, compared to rock core concentrations, suggest that CVOCs are presently back-diffusing from the rock matrix. Below the weathered and highly fractured strata, and to depths of at least 50 meters (m), groundwater flow and contaminant transport is primarily in bedding-plane-oriented fractures in thin fissile high-carbon strata, and in fractured, laminated strata of the gently

  4. High-resolution delineation of chlorinated volatile organic compounds in a dipping, fractured mudstone: depth- and strata-dependent spatial variability from rock-core sampling

    Science.gov (United States)

    Goode, Daniel J.; Imbrigiotta, Thomas E.; Lacombe, Pierre J.

    2014-01-01

    Synthesis of rock-core sampling and chlorinated volatile organic compound (CVOC) analysis at five coreholes, with hydraulic and water-quality monitoring and a detailed hydrogeologic framework, was used to characterize the fine-scale distribution of CVOCs in dipping, fractured mudstones of the Lockatong Formation of Triassic age, of the Newark Basin in West Trenton, New Jersey. From these results, a refined conceptual model for more than 55 years of migration of CVOCs and depth- and strata-dependent rock-matrix contamination was developed. Industrial use of trichloroethene (TCE) at the former Naval Air Warfare Center (NAWC) from 1953 to 1995 resulted in dense non-aqueous phase liquid (DNAPL) TCE and dissolved TCE and related breakdown products, including other CVOCs, in underlying mudstones. Shallow highly weathered and fractured strata overlie unweathered, gently dipping, fractured strata that become progressively less fractured with depth. The unweathered lithology includes black highly fractured (fissile) carbon-rich strata, gray mildly fractured thinly layered (laminated) strata, and light-gray weakly fractured massive strata. CVOC concentrations in water samples pumped from the shallow weathered and highly fractured strata remain elevated near residual DNAPL TCE, but dilution by uncontaminated recharge, and other natural and engineered attenuation processes, have substantially reduced concentrations along flow paths removed from sources and residual DNAPL. CVOCs also were detected in most rock-core samples in source areas in shallow wells. In many locations, lower aqueous concentrations, compared to rock core concentrations, suggest that CVOCs are presently back-diffusing from the rock matrix. Below the weathered and highly fractured strata, and to depths of at least 50 meters (m), groundwater flow and contaminant transport is primarily in bedding-plane-oriented fractures in thin fissile high-carbon strata, and in fractured, laminated strata of the gently

  5. On the energy dependence of the radial diffusion coefficient and spectra of inner radiation belt particles - Analytic solutions and comparison with numerical results

    Science.gov (United States)

    Westphalen, H.; Spjeldvik, W. N.

    1982-01-01

    A theoretical method by which the energy dependence of the radial diffusion coefficient may be deduced from spectral observations of the particle population at the inner edge of the earth's radiation belts is presented. This region has previously been analyzed with numerical techniques; in this report an analytical treatment that illustrates characteristic limiting cases in the L shell range where the time scale of Coulomb losses is substantially shorter than that of radial diffusion (L approximately 1-2) is given. It is demonstrated both analytically and numerically that the particle spectra there are shaped by the energy dependence of the radial diffusion coefficient regardless of the spectral shapes of the particle populations diffusing inward from the outer radiation zone, so that from observed spectra the energy dependence of the diffusion coefficient can be determined. To insure realistic simulations, inner zone data obtained from experiments on the DIAL, AZUR, and ESRO 2 spacecraft have been used as boundary conditions. Excellent agreement between analytic and numerical results is reported.

  6. 依据迭代系数状态因子分段的变步长NLMS算法%Segmental Variable Step-Size Normalized LMS Algorithm Dependent on the State Parameter of Iteration Coefficient

    Institute of Scientific and Technical Information of China (English)

    邹纯烨; 张剑云; 黄中瑞

    2015-01-01

    针对固定步长的归一化LMS算法(NLMS)存在不能同时兼顾收敛速度与稳态误差的问题,本文提出一种依据迭代系数状态因子进行分段的变步长NLMS算法。该变步长NLMS算法采用迭代系数状态因子作为表征迭代系数与实际系数的逼近状态的指标。当迭代系数状态因子值大于1,则说明迭代系数有偏离真实系数的趋势,此时采用步长因子较大的变步长方案;反之,说明迭代系数有逼近真实系数的趋势,应该采样步长因子较小的变步长方案。这样的自适应选择措施使得算法具有较强的收敛能力。理论分析和实验表明:在同样实验条件下,本文算法能够获得比其他文献更快的收敛速度和更小的稳态误差。%Fixed step size Normalized LMS algorithm can’t step out the dilemma of fast convergence rate and low excess mean-square error.To solve this problem,this paper proposed a Segmental Variable Step-Size Normalized LMS algorithm Dependent on the state parameter of iteration coefficient.This Normalized LMS algorithm employs the state parameter of it-eration coefficient to express the approximation degree between iteration coefficient and real coefficient.When the value of state parameter of iteration coefficient is larger than 1 ,which indicates that iteration coefficient tends to deviate from the re-al coefficient,at this time,variable step-size scheme that can provide larger step-size parameter is needed.However when the value of state parameter of iteration coefficient is smaller than 1 ,which indicates that iteration coefficient tends to ap-proach the real coefficient,at this time,variable step-size scheme that can provide smaller step-size parameter is needed. This adaptive selection of variable step-size scheme enables the proposed NLMS algorithm to have better convergence per-formance.Analysis and experiment results show that:under the same experimental condition,the proposed algorithm can

  7. New results on delay-range-dependent stability analysis for interval time-varying delay systems with non-linear perturbations.

    Science.gov (United States)

    Liu, Pin-Lin

    2015-07-01

    This paper studies the problem of the stability analysis of interval time-varying delay systems with nonlinear perturbations. Based on the Lyapunov-Krasovskii functional (LKF), a sufficient delay-range-dependent criterion for asymptotic stability is derived in terms of linear matrix inequality (LMI) and integral inequality approach (IIA) and delayed decomposition approach (DDA). Further, the delay range is divided into two equal segments for stability analysis. Both theoretical and numerical comparisons have been provided to show the effectiveness and efficiency of the present method. Two well-known examples are given to show less conservatism of our obtained results and the effectiveness of the proposed method.

  8. Meteorological variables affect fertility rate after intrauterine artificial insemination in sheep in a seasonal-dependent manner: a 7-year study

    Science.gov (United States)

    Palacios, C.; Abecia, J. A.

    2015-05-01

    A total number of 48,088 artificial inseminations (AIs) have been controlled during seven consecutive years in 79 dairy sheep Spanish farms (41° N). Mean, maximum and minimum ambient temperatures ( Ts), temperature amplitude (TA), mean relative humidity (RH), mean solar radiation (SR) and total rainfall of each insemination day and 15 days later were recorded. Temperature-humidity index (THI) and effective temperature (ET) have been calculated. A binary logistic regression model to estimate the risk of not getting pregnant compared to getting pregnant, through the odds ratio (OR), was performed. Successful winter inseminations were carried out under higher SR ( P 1 (maximum T, ET and rainfall on AI day, and ET and rainfall on day 15), and two variables presented OR reverse their effects in the hot or cold seasons. A forecast of the meteorological conditions could be a useful tool when AI dates are being scheduled.

  9. Relationship of push-ups and sit-ups tests to selected anthropometric variables and performance results: a multiple regression study.

    Science.gov (United States)

    Esco, Michael R; Olson, Michele S; Williford, Henry

    2008-11-01

    The purpose of this study was to explore whether selected anthropometric measures such as specific skinfold sites, along with weight, height, body mass index (BMI), waist and hip circumferences, and waist/hip ratio (WHR) were associated with sit-ups (SU) and push-ups (PU) performance, and to build a regression model for SU and PU tests. One hundred apparently healthy adults (40 men and 60 women) served as the subjects for test validation. The subjects performed 60-second SU and PU tests. The variables analyzed via multiple regression included weight, height, BMI, hip and waist circumferences, WHR, skinfolds at the abdomen (SFAB), thigh (SFTH), and subscapularis (SFSS), and sex. An additional cohort of 40 subjects (17 men and 23 women) was used to cross-validate the regression models. Validity was confirmed by correlation and paired t-tests. The regression analysis yielded a four-variable (PU, height, SFAB, and SFTH) multiple regression equation for estimating SU (R2 = 0.64, SEE = 7.5 repetitions). For PU, only SU was loaded into the regression equation (R2 = 0.43, SEE = 9.4 repetitions). Thus, the variables in the regression models accounted for 64% and 43% of the variation in SU and PU, respectively. The cross-validation sample elicited a high correlation for SU (r = 0.87) and PU (r = 0.79) scores. Moreover, paired-samples t-tests revealed that there were no significant differences between actual and predicted SU and PU scores. Therefore, this study shows that there are a number of selected, health-related anthropometric variables that account significantly for, and are predictive of, SU and PU tests.

  10. INTERACTION OF MACROECONOMIC VARIABLES WITH STOCK PRICES

    Directory of Open Access Journals (Sweden)

    ALİ ÖZER

    2013-06-01

    Full Text Available The aim of this study is to determine whether there is a relationship between ISE 100 Index and some macroeconomic variables by using monthly data of January 1996 – December 2009. ISE 100 Index was used as dependent variable and interest rates, money supply, foreign trade equilibrium, industrial production index, gold prices, exchange rates, consumer price index were used as independent variables. Least squares estimation method, Johansen-Jeselius cointegration test, Granger causality test and variance decomposition results produced by VEC model were used in the study. These analysis show that there is a long run relationship between some macroeconomic variables and stock prices.

  11. Menstrual Cycle Dependent Variability for Serum Tumor Markers CEA, AFP, CA 19-9, CA 125 and CA 15-3 in Healthy Women

    Directory of Open Access Journals (Sweden)

    Ayşe Binnur Erbağci

    1999-01-01

    Full Text Available Information on menstrual cycle dependent variation of tumor markers in healthy women is a subject of diagnostic efficiency and has an impact in elucidating the normal function of these markers. In this study midfollicular and midluteal concentrations of serum CEA, AFP, CA 19-9, CA 125, CA 15-3 and their relations with LH, FSH, prolactin, estradiol and progesterone were evaluated during ovulatory cycles in a group of 23 healthy female individuals. Samples were collected on the 7th and 21st day of the same menstrual cycle. Tumor marker and hormone concentrations were determined with chemiluminescence or electrochemiluminescence EIA methods. A significant phase-dependent difference was observed for CA 15-3, midluteal concentrations (mean ± SEM; 26.33 ± 1.56 U/ml higher than the midfollicular (mean ± SEM; 19.27 ± 1.49 U/ml concentrations (p < 0.001. But an obvious difference for other tumor markers investigated did not exist. Significant correlations of follicular and luteal CA 125 levels with body mass index of the subjects were observed (r:0.52, p < 0.05 and r:0.57, p < 0.005, respectively.

  12. Intraday Variability in Northern Hemisphere Radio Sources

    CERN Document Server

    Krichbaum, T P; Fuhrmann, L; Cimo, G; Witzel, A

    2001-01-01

    We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from now more than 40 high declination sources, which show Intraday Variability (IDV). In general, IDV is more pronounced for sources with flat radio spectra and compact VLBI structures. The frequency dependence of the variability pattern varies with source and observing time. For 0917+62, we present new VLBI images, which suggest that the variability pattern is modified by the occurrence of new jet components. For 0716+71, we show the first detection of IDV at millimeter wavelengths (32 GHz). For the physical interpretation of the IDV phenomenon, a complex source and frequency dependent superposition of interstellar scintillation and source intrinsic variability should be considered.

  13. Influence of demographic and tumour variables on prostate cancer treatment with curative intent in Spain. Results of the 2010 national prostate cancer registry.

    Science.gov (United States)

    Martínez-Jabaloyas, J M; Castelló-Porcar, A; González-Baena, A C; Cózar-Olmo, J M; Miñana-López, B; Gómez-Veiga, F; Rodriguez-Antolín, A

    2016-10-01

    The aim of this study is to determine which cancer and demographic criteria influence the indication for surgery (radical prostatectomy) or radiation therapy (external or brachytherapy) in the treatment of prostate cancer. An analysis of the 2714 patients of the 2010 National Prostate Cancer Registry treated with curative intent. The analysed variables were age, prostate-specific antigen (PSA), prostate volume, the number of biopsy cores, the percentage of positive cores, the stage, Gleason score, the type of pathologist, the presence of perineural invasion and the study centre. We analysed the association among these variables and the type of treatment (surgery vs. radiation therapy/brachytherapy), using a univariate analysis (Student's t test and chi-squared) and a binary multiple logistic regression. The 48.12% of the patients (1306/2714) were treated with surgery, and 51.88% (1,408/2,714) underwent radiation therapy/brachytherapy. Differences were observed between the patients treated with prostatectomy and those treated with radiation therapy/brachytherapy (p<.05) in age (63.50±6.5 vs. 69.0±6.7), PSA (8.76±16.97 vs. 13.21±15.88), biopsied cores, percentage of positives cores (30.0±22 vs. 38.7±29), Gleason score (G6: 53.9% vs. 46.1%; G7: 45% vs. 55% G8-10: 26.6%, 73.4%), stage (localised: 50% vs. 50%; locally advanced: 14.6% vs. 85.4%), perineural invasion and hospital centre. In the multivariate analysis, the selected independent variables were age, PSA, percentage of positives cores, stage, Gleason score and hospital centre. According to our study, age, tumour aggressiveness and stage and the centre where the patient will be treated affect the selection of curative treatment for prostate cancer. Copyright © 2016 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  14. Cell type-dependent induction of DNA damage by 1800 MHz radiofrequency electromagnetic fields does not result in significant cellular dysfunctions.

    Directory of Open Access Journals (Sweden)

    Shanshan Xu

    Full Text Available BACKGROUND: Although IARC clarifies radiofrequency electromagnetic fields (RF-EMF as possible human carcinogen, the debate on its health impact continues due to the inconsistent results. Genotoxic effect has been considered as a golden standard to determine if an environmental factor is a carcinogen, but the currently available data for RF-EMF remain controversial. As an environmental stimulus, the effect of RF-EMF on cellular DNA may be subtle. Therefore, more sensitive method and systematic research strategy are warranted to evaluate its genotoxicity. OBJECTIVES: To determine whether RF-EMF does induce DNA damage and if the effect is cell-type dependent by adopting a more sensitive method γH2AX foci formation; and to investigate the biological consequences if RF-EMF does increase γH2AX foci formation. METHODS: Six different types of cells were intermittently exposed to GSM 1800 MHz RF-EMF at a specific absorption rate of 3.0 W/kg for 1 h or 24 h, then subjected to immunostaining with anti-γH2AX antibody. The biological consequences in γH2AX-elevated cell type were further explored with comet and TUNEL assays, flow cytometry, and cell growth assay. RESULTS: Exposure to RF-EMF for 24 h significantly induced γH2AX foci formation in Chinese hamster lung cells and Human skin fibroblasts (HSFs, but not the other cells. However, RF-EMF-elevated γH2AX foci formation in HSF cells did not result in detectable DNA fragmentation, sustainable cell cycle arrest, cell proliferation or viability change. RF-EMF exposure slightly but not significantly increased the cellular ROS level. CONCLUSIONS: RF-EMF induces DNA damage in a cell type-dependent manner, but the elevated γH2AX foci formation in HSF cells does not result in significant cellular dysfunctions.

  15. Data-based estimates of the ocean carbon sink variability – first results of the Surface Ocean pCO2 Mapping intercomparison (SOCOM

    Directory of Open Access Journals (Sweden)

    C. Rödenbeck

    2015-08-01

    Full Text Available Using measurements of the surface-ocean CO2 partial pressure (pCO2 and 14 different pCO2 mapping methods recently collated by the Surface Ocean pCO2 Mapping intercomparison (SOCOM initiative, variations in regional and global sea–air CO2 fluxes have been investigated. Though the available mapping methods use widely different approaches, we find relatively consistent estimates of regional pCO2 seasonality, in line with previous estimates. In terms of interannual variability (IAV, all mapping methods estimate the largest variations to occur in the Eastern equatorial Pacific. Despite considerable spead in the detailed variations, mapping methods with closer match to the data also tend to be more consistent with each other. Encouragingly, this includes mapping methods belonging to complementary types – taking variability either directly from the pCO2 data or indirectly from driver data via regression. From a weighted ensemble average, we find an IAV amplitude of the global sea–air CO2 flux of 0.31 PgC yr−1 (standard deviation over 1992–2009, which is larger than simulated by biogeochemical process models. On a decadal perspective, the global CO2 uptake is estimated to have gradually increased since about 2000, with little decadal change prior to 2000. The weighted mean total ocean CO2 sink estimated by the SOCOM ensemble is consistent within uncertainties with estimates from ocean-interior carbon data or atmospheric oxygen trends.

  16. INVESTIGATION OF MEASUREMENT PRECISION OF LATENT VARIABLES IN EDUCATION

    Directory of Open Access Journals (Sweden)

    Anatoly A. Maslak Anatoly A.

    2014-01-01

    Full Text Available The objective of the study is to investigate the measurement accuracy of latent variables depending on a number of dichotomous test items and variation range.Methods: Investigation is based on the simulation experiments.Results: The authors make recommendations for selecting a number of dichotomous test items and variation range depending on the required measurement precision of latent variables.Scientific novelty: The research demonstrates statistical correlation between the measurement precision of latent variables and a number of test items and variation range.Importance for practice: The research results can be used while developing the questionnaires and tests for measuring the latent variables.

  17. Time-variable transit time distributions and transport: Theory and application to storage-dependent transport of chloride in a watershed

    Science.gov (United States)

    Harman, Ciaran J.

    2015-01-01

    Transport processes and pathways through many hydrodynamic systems vary over time, often driven by variations in total water storage. This paper develops a very general approach to modeling unsteady transport through an arbitrary control volume (such as a watershed) that accounts for temporal variability in the underlying transport dynamics. Controls on the selection of discharge from stored water are encapsulated in probability distributions ΩQ>(ST,t>) of age-ranked storage ST (the volume of water in storage ranked from youngest to oldest). This framework is applied to a long-term record of rainfall and streamflow chloride in a small, humid watershed at Plynlimon, UK. While a time-invariant gamma distribution for ΩQ produced a good fit to data, the fit was significantly improved when the distribution was allowed to vary with catchment storage. However, the variation was inverse to that of a "well-mixed" system where storage has a pure dilution effect. Discharge at high storage was predicted to contain a larger fraction of recent event water than at low storage. The effective volume of storage involved in transport was 3411 mm at mean catchment wetness, but declined by 71 mm per 1 mm of additional catchment storage, while the fraction of event water in discharge increased by 1.4%. This "inverse storage effect" is sufficient to reproduce the observed long-memory 1/f fractal spectral structure of stream chloride. Metrics quantifying the strength and direction of storage effects are proposed as useful signatures, and point toward a unified framework for observing and modeling coupled watershed flow and transport.

  18. Cell type-dependent induction of DNA damage by 1800 MHz radiofrequency electromagnetic fields does not result in significant cellular dysfunctions.

    Science.gov (United States)

    Xu, Shanshan; Chen, Guangdi; Chen, Chunjing; Sun, Chuan; Zhang, Danying; Murbach, Manuel; Kuster, Niels; Zeng, Qunli; Xu, Zhengping

    2013-01-01

    Although IARC clarifies radiofrequency electromagnetic fields (RF-EMF) as possible human carcinogen, the debate on its health impact continues due to the inconsistent results. Genotoxic effect has been considered as a golden standard to determine if an environmental factor is a carcinogen, but the currently available data for RF-EMF remain controversial. As an environmental stimulus, the effect of RF-EMF on cellular DNA may be subtle. Therefore, more sensitive method and systematic research strategy are warranted to evaluate its genotoxicity. To determine whether RF-EMF does induce DNA damage and if the effect is cell-type dependent by adopting a more sensitive method γH2AX foci formation; and to investigate the biological consequences if RF-EMF does increase γH2AX foci formation. Six different types of cells were intermittently exposed to GSM 1800 MHz RF-EMF at a specific absorption rate of 3.0 W/kg for 1 h or 24 h, then subjected to immunostaining with anti-γH2AX antibody. The biological consequences in γH2AX-elevated cell type were further explored with comet and TUNEL assays, flow cytometry, and cell growth assay. Exposure to RF-EMF for 24 h significantly induced γH2AX foci formation in Chinese hamster lung cells and Human skin fibroblasts (HSFs), but not the other cells. However, RF-EMF-elevated γH2AX foci formation in HSF cells did not result in detectable DNA fragmentation, sustainable cell cycle arrest, cell proliferation or viability change. RF-EMF exposure slightly but not significantly increased the cellular ROS level. RF-EMF induces DNA damage in a cell type-dependent manner, but the elevated γH2AX foci formation in HSF cells does not result in significant cellular dysfunctions.

  19. Chronic sympathoexcitation through loss of Vav3, a Rac1 activator, results in divergent effects on metabolic syndrome and obesity depending on diet.

    Science.gov (United States)

    Menacho-Márquez, Mauricio; Nogueiras, Rubén; Fabbiano, Salvatore; Sauzeau, Vincent; Al-Massadi, Omar; Diéguez, Carlos; Bustelo, Xosé R

    2013-08-01

    The role of the sympathetic nervous system, stress, and hypertension in metabolic syndrome and obesity remains unclear. To clarify this issue, we utilized genetically engineered mice showing chronic sympathoexcitation and hypertension due to lack of Vav3, a Rac1 activator. Here, we report that these animals develop metabolic syndrome under chow diet. However, they show protection from metabolic syndrome and obesity under fatty diets. These effects are elicited by α1-adrenergic- and diet-dependent metabolic changes in liver and the α1/β3 adrenergic-mediated stimulation of brown adipocyte thermogenesis. These responses seem to be engaged by the local action of noradrenaline in target tissues rather than by long-range effects of adrenaline. By contrast, they are not triggered by low parasympathetic drive or the hypertensive state present in Vav3-deficient mice. These results indicate that the sympathetic system plays divergent roles in the etiology of metabolic diseases depending on food regimen, sympathoexcitation source, and disease stage.

  20. Dependence of sports results on data of physical development, morphofunctional and special power preparedness of weight-lifters at the stage of initial preparation

    Directory of Open Access Journals (Sweden)

    Eugene Bugaev

    2016-12-01

    Full Text Available Purpose: the establishment of nature of the interrelation between sports results of weight-lifters and level of their special physical and morphofunctional preparedness. Material & Methods: 48 sportsmen of group of initial preparation of the first year of training were involved to the experiment. The research was conducted on the basis of the chair of weightlifting and boxing of Kharkov state academy of physical culture and CYSS “HTZ”. Results: the correlation between indicators of morphofunctional, high-speed and power and special (competitive preparedness of weight-lifters is revealed at the stage of initial preparation. The conducted research shows that the result of competitive exercises of the sportsmen, specializing in weightlifting at the stage of initial preparation, depends on power and high-speed and power preparedness. Conclusions: it is established that the correlation between results of competitive exercises and jumps uphill from the place, in length from the place, run on 30 m can demonstrate the interrelation of power and high-speed and power preparedness of the sportsmen, specializing in weightlifting at the stage of initial preparation.

  1. An analysis of Taguchi's on-line quality monitoring procedure for variables based on the results of a sequence of inspections

    Directory of Open Access Journals (Sweden)

    Linda Lee Ho

    2012-04-01

    Full Text Available In this paper, a procedure for the on-line process control of variables is proposed. This procedure consists of inspecting the m-th item from every m produced items and deciding, at each inspection, whether the process is out-of-control. Two sets of limits, warning (µ0 ± W and control (µ0 ± C, are used. If the value of the monitored statistic falls beyond the control limits or if a sequence of h observations falls between the warning limits and the control limits, the production is stopped for adjustment; otherwise, production goes on. The properties of an ergodic Markov chain are used to obtain an expression for the average cost per item. The parameters (the sampling interval m, the widths of the warning, the control limits W and C(W < C, and the sequence length (h are optimized by minimizing the cost function. A numerical example illustrates the proposed procedure.

  2. A Monte Carlo Study of the Momentum Dependence on the Results of Tracking Unknown Particle Species in the BaBar Detector

    Energy Technology Data Exchange (ETDEWEB)

    Sewerynek, Stephen; /British Columbia U.

    2007-04-06

    The BABAR experiment is composed of an international collaboration that will test the Standard Model prediction of CP violation. To accomplish this a new detector was constructed at the asymmetric B Factory, located at the Stanford Linear Accelerator Center. The tests will shed some light on the origins of CP violation, which is an important aspect in explaining the matter/antimatter asymmetry in the universe. In particular, the BABAR experiment will measure CP violation in the neutral B meson system. In order to succeed, the BABAR experiment requires excellent track fitting and particle species identification. Prior to the current study, track fitting was done using only one particle species--the pion. But given the momentum dependence on the accuracy of the results from this choice of particle species, a better algorithm needed to be developed. Monte Carlo simulations were carried out and a new algorithm utilizing all five particle species present in the BABAR detector was created.

  3. Variables That Can Affect Student Ratings of Their Professors

    Science.gov (United States)

    Gotlieb, Jerry

    2013-01-01

    Attribution theory was applied to help predict the results of an experiment that examined the effects of three independent variables on students' ratings of their professors. The dependent variables were students' perceptions of whether the professor caused the students' grades and student satisfaction with their professor. The results suggest…

  4. Caspofungin Treatment of Aspergillus fumigatus Results in ChsG-Dependent Upregulation of Chitin Synthesis and the Formation of Chitin-Rich Microcolonies.

    Science.gov (United States)

    Walker, Louise A; Lee, Keunsook K; Munro, Carol A; Gow, Neil A R

    2015-10-01

    Treatment of Aspergillus fumigatus with echinocandins such as caspofungin inhibits the synthesis of cell wall β-1,3-glucan, which triggers a compensatory stimulation of chitin synthesis. Activation of chitin synthesis can occur in response to sub-MICs of caspofungin and to CaCl2 and calcofluor white (CFW), agonists of the protein kinase C (PKC), and Ca(2+)-calcineurin signaling pathways. A. fumigatus mutants with the chs gene (encoding chitin synthase) deleted (ΔAfchs) were tested for their response to these agonists to determine the chitin synthase enzymes that were required for the compensatory upregulation of chitin synthesis. Only the ΔAfchsG mutant was hypersensitive to caspofungin, and all other ΔAfchs mutants tested remained capable of increasing their chitin content in response to treatment with CaCl2 and CFW and caspofungin. The resulting increase in cell wall chitin content correlated with reduced susceptibility to caspofungin in the wild type and all ΔAfchs mutants tested, with the exception of the ΔAfchsG mutant, which remained sensitive to caspofungin. In vitro exposure to the chitin synthase inhibitor, nikkomycin Z, along with caspofungin demonstrated synergistic efficacy that was again AfChsG dependent. Dynamic imaging using microfluidic perfusion chambers demonstrated that treatment with sub-MIC caspofungin resulted initially in hyphal tip lysis. However, thickened hyphae emerged that formed aberrant microcolonies in the continued presence of caspofungin. In addition, intrahyphal hyphae were formed in response to echinocandin treatment. These in vitro data demonstrate that A. fumigatus has the potential to survive echinocandin treatment in vivo by AfChsG-dependent upregulation of chitin synthesis. Chitin-rich cells may, therefore, persist in human tissues and act as the focus for breakthrough infections.

  5. Toxoplasma gondii rhoptry kinase ROP16 activates STAT3 and STAT6 resulting in cytokine inhibition and arginase-1-dependent growth control.

    Directory of Open Access Journals (Sweden)

    Barbara A Butcher

    2011-09-01

    Full Text Available The ROP16 kinase of Toxoplasma gondii is injected into the host cell cytosol where it activates signal transducer and activator of transcription (STAT-3 and STAT6. Here, we generated a ROP16 deletion mutant on a Type I parasite strain background, as well as a control complementation mutant with restored ROP16 expression. We investigated the biological role of the ROP16 molecule during T. gondii infection. Infection of mouse bone marrow-derived macrophages with rop16-deleted (ΔROP16 parasites resulted in increased amounts of IL-12p40 production relative to the ROP16-positive RH parental strain. High level IL-12p40 production in ΔROP16 infection was dependent on the host cell adaptor molecule MyD88, but surprisingly was independent of any previously recognized T. gondii triggered pathway linking to MyD88 (TLR2, TLR4, TLR9, TLR11, IL-1ß and IL-18. In addition, ROP16 was found to mediate the suppressive effects of Toxoplasma on LPS-induced cytokine synthesis in macrophages and on IFN-γ-induced nitric oxide production by astrocytes and microglial cells. Furthermore, ROP16 triggered synthesis of host cell arginase-1 in a STAT6-dependent manner. In fibroblasts and macrophages, failure to induce arginase-1 by ΔROP16 tachyzoites resulted in resistance to starvation conditions of limiting arginine, an essential amino acid for replication and virulence of this parasite. ΔROP16 tachyzoites that failed to induce host cell arginase-1 displayed increased replication and dissemination during in vivo infection. We conclude that encounter between Toxoplasma ROP16 and the host cell STAT signaling cascade has pleiotropic downstream effects that act in multiple and complex ways to direct the course of infection.

  6. Does the perception of fairness and standard of care in the health system depend on the field of study? Results of an empirical analysis.

    Science.gov (United States)

    Damm, Kathrin; Prenzler, Anne; Zuchandke, Andy

    2014-04-12

    The main challenge in the context of health care reforms and priority setting is the establishment and/or maintenance of fairness and standard of care. For the political process and interdisciplinary discussion, the subjective perception of the health care system might even be as important as potential objective criteria. Of special interest are the perceptions of academic disciplines, whose representatives act as decision makers in the health care sector. The aim of this study is to explore and compare the subjective perception of fairness and standard of care in the German health care system among students of medicine, law, economics, philosophy, and religion. Between October 2011 and January 2012, we asked freshmen and advanced students of the fields mentioned above to participate in a paper and pencil survey. Prior to this, we formulated hypotheses. The data were analysed by micro econometric regression techniques. Data from 1,088 students were included in the study. Medical students, freshmen, and advanced students perceive the standard of care significantly as being better than non-medical students. Differences in the perception of fairness are not significant between the freshmen of the academic disciplines; however, they increase with the number of study terms. Besides the field of study, further variables such as gender and health status have a significant impact on perceptions. Our results show that there are differences in the perception of fairness and standard of care between academic disciplines, which might influence the interdisciplinary discussion on health care reforms and priority setting.

  7. Relative solvation free energies calculated using an ab initio QM/MM-based free energy perturbation method: dependence of results on simulation length.

    Science.gov (United States)

    Reddy, M Rami; Erion, Mark D

    2009-12-01

    Molecular dynamics (MD) simulations in conjunction with thermodynamic perturbation approach was used to calculate relative solvation free energies of five pairs of small molecules, namely; (1) methanol to ethane, (2) acetone to acetamide, (3) phenol to benzene, (4) 1,1,1 trichloroethane to ethane, and (5) phenylalanine to isoleucine. Two studies were performed to evaluate the dependence of the convergence of these calculations on MD simulation length and starting configuration. In the first study, each transformation started from the same well-equilibrated configuration and the simulation length was varied from 230 to 2,540 ps. The results indicated that for transformations involving small structural changes, a simulation length of 860 ps is sufficient to obtain satisfactory convergence. In contrast, transformations involving relatively large structural changes, such as phenylalanine to isoleucine, require a significantly longer simulation length (>2,540 ps) to obtain satisfactory convergence. In the second study, the transformation was completed starting from three different configurations and using in each case 860 ps of MD simulation. The results from this study suggest that performing one long simulation may be better than averaging results from three different simulations using a shorter simulation length and three different starting configurations.

  8. Probability Inequalities for Extended Negatively Dep endent Random Variables and Their Applications

    Institute of Scientific and Technical Information of China (English)

    TANG Xiao-feng

    2014-01-01

    Some probability inequalities are established for extended negatively dependent (END) random variables. The inequalities extend some corresponding ones for negatively associated random variables and negatively orthant dependent random variables. By using these probability inequalities, we further study the complete convergence for END random variables. We also obtain the convergence rate O(n−1/2 ln1/2 n) for the strong law of large numbers, which generalizes and improves the corresponding ones for some known results.

  9. Is CH4 consumption by soils controlled by physics or biology? Results from a study of plot-scale variability of greenhouse gas fluxes

    Science.gov (United States)

    Maier, Martin; Paulus, Sinikka; Nicolai, Clara; Nauer, Philipp

    2017-04-01

    Soil-atmosphere fluxes of trace gases vary on different spatial scales, between landscapes and ecosystems down to the plot scale within apparently homogenous sites. The production and consumption of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) underlie different spatial and temporal changes, und thus, their interrelation is difficult to unravel. Small-scale variability in soil properties is well-known from soil surveys, affecting theoretically water availability for plants, soil aeration, vegetation, the local photosynthesis rate, and, eventually, greenhouse gas fluxes. We investigated the small scale variability of greenhouse gas fluxes in a homogenous Scots Pine stand in a former riparian flood plain. Soil-atmosphere fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) were carried out at 60 points on a 250 m2 plot with strata of diverse soil substrates and understory vegetation. Gas flux measurements were combined with soil physical lab measurements, and a soil vegetation survey. The soil was a source of CO2 and a sink for CH4 and N2O. No correlations between the fluxes and only weak correlations between the fluxes and soil physical factors were observed. CH4 and CO2 fluxes were significantly different for the soil-vegetation strata. Separating the dataset into the different soil-vegetation strata showed that CH4 consumption increased significantly with soil gas diffusivity and soil respiration. Methane consumption in the silt stratum was higher at a given soil gas diffusivity than in the sand stratum, indicating a higher methanotrophic microbe population and thus better habitats in silt. CH4 consumption increased with soil respiration in all strata, so that we speculate that the rhizosphere and decomposing organic litter (as origin of most of the soil respiration) facilitate a preferred habitat of methanotrophic microbes. The patterns of N2O consumption were more complex, but consumption seemed to be limited at locations with

  10. Does the perception of fairness and standard of care in the health system depend on the field of study? Results of an empirical analysis

    Science.gov (United States)

    2014-01-01

    Background The main challenge in the context of health care reforms and priority setting is the establishment and/or maintenance of fairness and standard of care. For the political process and interdisciplinary discussion, the subjective perception of the health care system might even be as important as potential objective criteria. Of special interest are the perceptions of academic disciplines, whose representatives act as decision makers in the health care sector. The aim of this study is to explore and compare the subjective perception of fairness and standard of care in the German health care system among students of medicine, law, economics, philosophy, and religion. Methods Between October 2011 and January 2012, we asked freshmen and advanced students of the fields mentioned above to participate in a paper and pencil survey. Prior to this, we formulated hypotheses. The data were analysed by micro econometric regression techniques. Results Data from 1,088 students were included in the study. Medical students, freshmen, and advanced students perceive the standard of care significantly as being better than non-medical students. Differences in the perception of fairness are not significant between the freshmen of the academic disciplines; however, they increase with the number of study terms. Besides the field of study, further variables such as gender and health status have a significant impact on perceptions. Conclusions Our results show that there are differences in the perception of fairness and standard of care between academic disciplines, which might influence the interdisciplinary discussion on health care reforms and priority setting. PMID:24725356

  11. The Influence of New Colored Light Stimulation Methods on Heart Rate Variability, Temperature, and Well-Being: Results of a Pilot Study in Humans

    Directory of Open Access Journals (Sweden)

    Daniela Litscher

    2013-01-01

    Full Text Available Changes of light intensity of different colors can shift many physiological parameters and conditions like melatonin, alertness, body temperature, heart rate (HR, and heart rate variability (HRV. The aim of this pilot study was to investigate acute temperature, HR, HRV, and state of mind reactivities after illumination with red (631 nm and blue (456 nm light (illuminance 140 lux for both. Seven healthy volunteers (5 females, 2 males; mean age ± SD 34.1 ± 11.9 years were investigated at the Medical University of Graz, using new color light panels. Significant decreases were found only after 10 min blue light stimulation in nose temperature (P=0.046, HR (P<0.05, and total HRV (P=0.029, in association with a significant alteration of the emotional state (stress level score, P=0.006. However, red light stimulation of the same persons did not induce the same effects in these parameters. The effect of blue light as environmental stimulation on human health is not clarified in detail and needs further investigations.

  12. Modeling Shared Variables in VHDL

    DEFF Research Database (Denmark)

    Madsen, Jan; Brage, Jens P.

    1994-01-01

    A set of concurrent processes communicating through shared variables is an often used model for hardware systems. This paper presents three modeling techniques for representing such shared variables in VHDL, depending on the acceptable constraints on accesses to the variables. Also a set of guide......A set of concurrent processes communicating through shared variables is an often used model for hardware systems. This paper presents three modeling techniques for representing such shared variables in VHDL, depending on the acceptable constraints on accesses to the variables. Also a set...

  13. Inactivation of the global regulator LaeA in Monascus ruber results in a species-dependent response in sporulation and secondary metabolism.

    Science.gov (United States)

    Liu, Qingpei; Cai, Li; Shao, Yanchun; Zhou, Youxiang; Li, Mu; Wang, Xiaohong; Chen, Fusheng

    2016-03-01

    The nuclear regulator LaeA has been proven to globally govern fungal development and secondary metabolism, but its function may be species-dependent, even though its amino acid sequences are well conserved in numerous fungi. Herein we identified the LaeA in Monascus ruber M7 (MrLaeA), and verified its role to mediate growth, sporulation and secondary metabolism. Results showed that the radial growth rate of the selected MrlaeA knock-out mutant (MrΔlaeA-22) was significantly faster than that of the parental strain M. ruber M7, and growth was accompanied by the formation of an abnormal colony phenotype with more abundant aerial hyphae. Interestingly, conidia production of the MrΔlaeA-22 strain was about thrice that of M. ruber M7, but ascospores were not observed in the MrΔlaeA-22 strain. Additionally, compared to M. ruber M7, MrΔlaeA-22 exhibited drastically reduced production of multiple secondary metabolites, especially those of the six well-known Monascus pigments and citrinin. Simultaneously, the selected MrlaeA complementation strain (MrΔlaeA::laeA-45) nearly recovered the capacity for sporulation and secondary metabolism observed in the parental strain. These results demonstrate that MrLaeA regulates not only secondary metabolism, but also asexual and sexual differentiation in M. ruber, but some of its regulation appears to differ from other fungi.

  14. Strong Laws of Large Numbers for Arrays of Rowwise NA and LNQD Random Variables

    Directory of Open Access Journals (Sweden)

    Jiangfeng Wang

    2011-01-01

    Full Text Available Some strong laws of large numbers and strong convergence properties for arrays of rowwise negatively associated and linearly negative quadrant dependent random variables are obtained. The results obtained not only generalize the result of Hu and Taylor to negatively associated and linearly negative quadrant dependent random variables, but also improve it.

  15. Phenotypic variability in Waardenburg syndrome resulting from a 22q12.3-q13.1 microdeletion involving SOX10.

    Science.gov (United States)

    Jelena, Brezo; Christina, Lam; Eric, Vilain; Fabiola, Quintero-Rivera

    2014-06-01

    Waardenburg syndrome (WS) is a neurocristopathy characterized by pigmentation abnormalities of the skin, hair, and iris, as well as sensorineural hearing loss. Contiguous gene deletions encompassing SOX10 are rare, which limits conclusions about genotype-phenotype correlation regarding patient prognosis and management. This study adds to the existing body of knowledge by characterizing a 2.4 Mb deletion [arr[hg19] 22q12.3-q13.1 (36467502-38878207)x1] encompassing SOX10 and 53 additional RefSeq genes in a 15-year-old female with atypical WS. The patient presented with developmental delay, profound bilateral sensorineural hearing loss, heterochromia iridis, hypotonia, and bilateral finger contractures. Published genomic and phenotypic profiles of patients with SOX10-encompassing deletions point toward several plausible candidate gene that could account for the considerable clinical heterogeneity. These studies suggest the existence of modifiers among the co-deleted, dosage-sensitive genes (e.g., MYH9) and among genes whose effect may depend on the unmasking of recessive mutations (e.g., PLA2G6). Finally, we highlight evidence illustrating extensive interconnectivity of SOX10-hypothesizing that haploinsufficiency of SOX10 may "unmask" subtler effects on expression or epistasis associated with variants in SOX10 targets (e.g., DHH), in its partners (e.g., PAX3, EGR2), and in genes with functional overlap (e.g., SOX8, SOX9).

  16. Prognostic relevance of the interaction between short-term, metronome-paced heart rate variability, and inflammation: results from the population-based CARLA cohort study.

    Science.gov (United States)

    Medenwald, Daniel; Swenne, Cees A; Loppnow, Harald; Kors, Jan A; Pietzner, Diana; Tiller, Daniel; Thiery, Joachim; Nuding, Sebastian; Greiser, Karin H; Haerting, Johannes; Werdan, Karl; Kluttig, Alexander

    2017-01-01

    To determine the interaction between HRV and inflammation and their association with cardiovascular/all-cause mortality in the general population. Subjects of the CARLA study (n = 1671; 778 women, 893 men, 45-83 years of age) were observed for an average follow-up period of 8.8 years (226 deaths, 70 cardiovascular deaths). Heart rate variability parameters were calculated from 5-min segments of 20-min resting electrocardiograms. High-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and soluble tumour necrosis factor-alpha receptor type 1 (sTNF-R1) were measured as inflammation parameters. The HRV parameters determined included the standard deviation of normal-to-normal intervals (SDNN), the root-mean-square of successive normal-interval differences (RMSSD), the low- and high-frequency (HF) power, the ratio of both, and non-linear parameters [Poincaré plot (SD1, SD2, SD1/SD2), short-term detrended fluctuation analysis]. We estimated hazard ratios by using covariate-adjusted Cox regression for cardiovascular and all-cause mortality incorporating an interaction term of HRV/inflammation parameters. Relative excess risk due to interactions (RERIs) were computed. We found an interaction effect of sTNF-R1 with SDNN (RERI: 0.5; 99% confidence interval (CI): 0.1-1.0), and a weaker effect with RMSSD (RERI: 0.4; 99% CI: 0.0-0.9) and HF (RERI: 0.4; 99% CI: 0.0-0.9) with respect to cardiovascular mortality on an additive scale after covariate adjustment. Neither IL-6 nor hsCRP showed a significant interaction with the HRV parameters. A change in TNF-α levels or the autonomic nervous system influences the mortality risk through both entities simultaneously. Thus, TNF-α and HRV need to be considered when predicating mortality. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

  17. Dependability of results in conference abstracts of randomized controlled trials in ophthalmology and author financial conflicts of interest as a factor associated with full publication.

    Science.gov (United States)

    Saldanha, Ian J; Scherer, Roberta W; Rodriguez-Barraquer, Isabel; Jampel, Henry D; Dickersin, Kay

    2016-04-26

    as  20 %, and unclear in 14, 5, 14, and 7 pairs, respectively. First authors reporting of one or more conflicts of interest was associated with a greater likelihood of publication (RR = 1.31; 95 % CI = 1.04 to 1.64) and a shorter time-to-publication (log-rank p = 0.026). First author conflicts of interests that were associated with publication were financial support (RR = 1.50; 95 % CI = 1.19 to 1.90) and one or more gifts (RR = 1.42; 95 % CI = 1.05 to 1.92). The association between conflicts of interest and publication remained, irrespective of the statistical significance of the results. More than half the abstract/publication pairs exhibited some amount of discordance in the main outcome results, calling into question the dependability of conference abstracts. Regardless of the main outcome results, the conflicts of interests of the abstract's first author were associated with publication.

  18. Kaempferol Activates G₂-Checkpoint of the Cell Cycle Resulting in G₂-Arrest and Mitochondria-Dependent Apoptosis in Human Acute Leukemia Jurkat T Cells.

    Science.gov (United States)

    Kim, Ki Yun; Jang, Won Young; Lee, Ji Young; Jun, Do Youn; Ko, Jee Youn; Yun, Young Ho; Kim, Young Ho

    2016-02-01

    The effect of kaempferol (3,5,7,4-tetrahydroxyflavone), a flavonoid compound that was identified in barnyard millet (Echinochloa crus-galli var. frumentacea) grains, on G2-checkpoint and apoptotic pathways was investigated in human acute leukemia Jurkat T cell clones stably transfected with an empty vector (J/Neo) or a Bcl-xL expression vector (J/Bcl-xL). Exposure of J/Neo cells to kaempeferol caused cytotoxicity and activation of the ATM/ATR-Chk1/Chk2 pathway, activating the phosphorylation of p53 (Ser-15), inhibitory phosphorylation of Cdc25C (Ser-216), and inactivation of cyclin-dependent kinase 1 (Cdk1), with resultant G2- arrest of the cell cycle. Under these conditions, apoptotic events, including upregulation of Bak and PUMA levels, Bak activation, mitochondrial membrane potential (Δψm) loss, activation of caspase-9, -8, and -3, anti-poly (ADP-ribose) polymerase (PARP) cleavage, and accumulation of apoptotic sub-G1 cells, were induced without accompanying necrosis. However, these apoptotic events, except for upregulation of Bak and PUMA levels, were completely abrogated in J/Bcl-xL cells overexpressing Bcl-xL, suggesting that the G2-arrest and the Bcl-xL-sensitive mitochondrial apoptotic events were induced, in parallel, as downstream events of the DNA-damage-mediated G2-checkpoint activation. Together these results demonstrate that kaempferol-mediated antitumor activity toward Jurkat T cells was attributable to G2-checkpoint activation, which caused not only G2-arrest of the cell cycle but also activating phosphorylation of p53 (Ser-15) and subsequent induction of mitochondriadependent apoptotic events, including Bak and PUMA upregulation, Bak activation, Δpsim loss, and caspase cascade activation.

  19. Osteopetrorickets due to Snx10 deficiency in mice results from both failed osteoclast activity and loss of gastric acid-dependent calcium absorption.

    Directory of Open Access Journals (Sweden)

    Liang Ye

    2015-03-01

    Full Text Available Mutations in sorting nexin 10 (Snx10 have recently been found to account for roughly 4% of all human malignant osteopetrosis, some of them fatal. To study the disease pathogenesis, we investigated the expression of Snx10 and created mouse models in which Snx10 was knocked down globally or knocked out in osteoclasts. Endocytosis is severely defective in Snx10-deficient osteoclasts, as is extracellular acidification, ruffled border formation, and bone resorption. We also discovered that Snx10 is highly expressed in stomach epithelium, with mutations leading to high stomach pH and low calcium solubilization. Global Snx10-deficiency in mice results in a combined phenotype: osteopetrosis (due to osteoclast defect and rickets (due to high stomach pH and low calcium availability, resulting in impaired bone mineralization. Osteopetrorickets, the paradoxical association of insufficient mineralization in the context of a positive total body calcium balance, is thought to occur due to the inability of the osteoclasts to maintain normal calcium-phosphorus homeostasis. However, osteoclast-specific Snx10 knockout had no effect on calcium balance, and therefore led to severe osteopetrosis without rickets. Moreover, supplementation with calcium gluconate rescued mice from the rachitic phenotype and dramatically extended life span in global Snx10-deficient mice, suggesting that this may be a life-saving component of the clinical approach to Snx10-dependent human osteopetrosis that has previously gone unrecognized. We conclude that tissue-specific effects of Snx10 mutation need to be considered in clinical approaches to this disease entity. Reliance solely on hematopoietic stem cell transplantation can leave hypocalcemia uncorrected with sometimes fatal consequences. These studies established an essential role for Snx10 in bone homeostasis and underscore the importance of gastric acidification in calcium uptake.

  20. Combining Speed and Accuracy in Cognitive Psychology: Is the Inverse Efficiency Score (IES a Better Dependent Variable than the Mean Reaction Time (RT and the Percentage Of Errors (PE?

    Directory of Open Access Journals (Sweden)

    Raymond Bruyer

    2011-02-01

    Full Text Available Experiments in cognitive psychology usually return two dependent variables: the percentage of errors and the reaction time of the correct responses. Townsend and Ashby (1978, 1983 proposed the inverse efficiency score (IES as a way to combine both measures and, hence, to provide a better summary of the findings. In this article we examine the usefulness of IES by applying it to existing datasets. Although IES does give a better summary of the findings in some cases, mostly the variance of the measure is increased to such an extent that it becomes less interesting. Against our initial hopes, we have to conclude that it is not a good idea to limit the statistical analyses to IES without further checking the data.

  1. Should prior FIT results be incorporated as an additional variable to estimate risk of colorectal neoplasia? A prospective study of 5,813 screening colonoscopies.

    Directory of Open Access Journals (Sweden)

    Martin C S Wong

    Full Text Available Recent studies showed that previous negative results from faecal immunochemical tests (FITs for colorectal cancer (CRC screening was associated with lower risk of advanced neoplasia (AN. We evaluated whether prior FIT results should be included to estimate the risk of AN in 2008-2012.A community-based screening practice recruited 5,813 asymptomatic residents aged 50 to 70 years in Hong Kong for CRC screening. We included study participants who had (1. positive FIT with subsequent colonoscopy workup (FIT+ group; n = 356; (2. negative FIT in three consecutive years and received a colonoscopy (FIT- group; n = 857; (3. received colonoscopy without FIT (colonoscopy group; n = 473; and (4. received both colonoscopy and FIT at the same time (combined group; n = 4,127. One binary logistic regression model evaluated whether prior FIT results were associated with colonoscopy findings of AN.The proportion of participants having AN/CRC was 18.0% (FIT+, 5.5% (FIT-, 8.0% (colonoscopy group, and 4.3% (combined group, respectively. When compared with the colonoscopy group, those in the FIT- group were not significantly more or less likely to have AN/CRC (AOR = 0.77, 95% C.I. = 0.51 to 1.18, p = 0.230. Having one (AOR = 0.73, 95% C.I. 0.48-1.12, p = 0.151 or three consecutive negative FIT result (AOR = 0.98, 95% C.I. 0.60-1.62, p = 0.944 were not associated with lower risks of AN/CRC. Subjects in the FIT+ group was 3.32-fold (95% C.I. 2.07 to 5.32, p < 0.001 more likely to have AN/CRC.These findings indicated that subjects with negative FIT findings could be risk stratified similarly as those who had not previously received FIT.

  2. Fatigue Crack Growth Rate Test Results for Al-Li 2195 Parent Metal, Variable Polarity Plasma Arc Welds and Friction Stir Welds

    Science.gov (United States)

    Hafley, Robert A.; Wagner, John A.; Domack, Marcia S.

    2000-01-01

    The fatigue crack growth rate of aluminum-lithium (Al-Li) alloy 2195 plate and weldments was determined at 200-F, ambient temperature and -320-F. The effects of stress ratio (R), welding process, orientation and thickness were studied. Results are compared with plate data from the Space Shuttle Super Lightweight Tank (SLWT) allowables program. Data from the current series of tests, both plate and weldment, falls within the range of data generated during the SLWT allowables program.

  3. Strong near-epoch dependence

    Institute of Scientific and Technical Information of China (English)

    LIN Zhengyan

    2004-01-01

    We introduce a new class of dependent sequences of random variables, which is a subclass of near-epoch dependent sequences, but can also be approximated by mixing sequences. For this kind of sequences of random variables, we call them strong nearepoch dependent sequences, a p-order, p > 2, (maximum) moment inequality is established under weaker dependence sizes.

  4. Variable laterality of corticospinal tract axons that regenerate after spinal cord injury as a result of PTEN deletion or knock-down.

    Science.gov (United States)

    Willenberg, Rafer; Zukor, Katherine; Liu, Kai; He, Zhigang; Steward, Oswald

    2016-09-01

    Corticospinal tract (CST) axons from one hemisphere normally extend and terminate predominantly in the contralateral spinal cord. We previously showed that deleting the gene phosphatase and tensin homolog (PTEN) in the sensorimotor cortex enables CST axons to regenerate after spinal cord injury and that some regenerating axons extend along the "wrong" side. Here, we characterize the degree of specificity of regrowth in terms of laterality. PTEN was selectively deleted via cortical adeno-associated virus (AAV)-Cre injections in neonatal PTEN-floxed mice. As adults, mice received dorsal hemisection injuries at T12 or complete crush injuries at T9. CST axons from one hemisphere were traced by unilateral biotinylated dextran amine (BDA) injections in PTEN-deleted mice with spinal cord injury and in noninjured PTEN-floxed mice that had not received AAV-Cre. In noninjured mice, 97.9 ± 0.7% of BDA-labeled axons in white matter and 88.5 ± 1.0% of BDA-labeled axons in gray matter were contralateral to the cortex of origin. In contrast, laterality of CST axons that extended past a lesion due to PTEN deletion varied across animals. In some cases, regenerated axons extended predominantly on the ipsilateral side; in other cases, axons extended predominantly contralaterally, and in others, axons were similar in numbers on both sides. Similar results were seen in analyses of cases from previous studies using short hairpin (sh)RNA-mediated PTEN knock-down. These results indicate that CST axons that extend past a lesion due to PTEN deletion or knock-down do not maintain the contralateral rule of the noninjured CST, highlighting one aspect of how the resultant circuitry from regenerating axons may differ from that of the uninjured CST. J. Comp. Neurol. 524:2654-2676, 2016. © 2016 Wiley Periodicals, Inc.

  5. Moderate hypoxia followed by reoxygenation results in blood-brain barrier breakdown via oxidative stress-dependent tight-junction protein disruption.

    Directory of Open Access Journals (Sweden)

    Christoph M Zehendner

    Full Text Available Re-canalization of cerebral vessels in ischemic stroke is pivotal to rescue dysfunctional brain areas that are exposed to moderate hypoxia within the penumbra from irreversible cell death. Goal of the present study was to evaluate the effect of moderate hypoxia followed by reoxygenation (MHR on the evolution of reactive oxygen species (ROS and blood-brain barrier (BBB integrity in brain endothelial cells (BEC. BBB integrity was assessed in BEC in vitro and in microvessels of the guinea pig whole brain in situ preparation. Probes were exposed to MHR (2 hours 67-70 mmHg O2, 3 hours reoxygenation, BEC or towards occlusion of the arteria cerebri media (MCAO with or without subsequent reperfusion in the whole brain preparation. In vitro BBB integrity was evaluated using trans-endothelial electrical resistance (TEER and transwell permeability assays. ROS in BEC were evaluated using 2',7'-dichlorodihydrofluorescein diacetate (DCF, MitoSox and immunostaining for nitrotyrosine. Tight-junction protein (TJ integrity in BEC, stainings for nitrotyrosine and FITC-albumin extravasation in the guinea pig brain preparation were assessed by confocal microscopy. Diphenyleneiodonium (DPI was used to investigate NADPH oxidase dependent ROS evolution and its effect on BBB parameters in BEC. MHR impaired TJ proteins zonula occludens 1 (ZO-1 and claudin 5 (Cl5, decreased TEER, and significantly increased cytosolic ROS in BEC. These events were blocked by the NADPH oxidase inhibitor DPI. MCAO with or without subsequent reoxygenation resulted in extravasation of FITC-albumin and ROS generation in the penumbra region of the guinea pig brain preparation and confirmed BBB damage. BEC integrity may be impaired through ROS in MHR on the level of TJ and the BBB is also functionally impaired in moderate hypoxic conditions followed by reperfusion in a complex guinea pig brain preparation. These findings suggest that the BBB is susceptible towards MHR and that ROS play a key role

  6. Hysteresis-like binding of coagulation factors X/Xa to procoagulant activated platelets and phospholipids results from multistep association and membrane-dependent multimerization.

    Science.gov (United States)

    Podoplelova, Nadezhda A; Sveshnikova, Anastasia N; Kurasawa, James H; Sarafanov, Andrey G; Chambost, Herve; Vasil'ev, Sergey A; Demina, Irina A; Ataullakhanov, Fazly I; Alessi, Marie-Christine; Panteleev, Mikhail A

    2016-06-01

    Binding of coagulation factors X (fX) and Xa (fXa) to activated platelets is required for the formation of membrane-dependent enzymatic complexes of intrinsic tenase and prothrombinase. We carried out an in-depth characterization of fX/fXa binding to phospholipids and gel-filtered, thrombin-activated platelets. Flow cytometry, surface plasmon resonance, and computational modeling were used to investigate interactions of fX/fXa with the membranes. Confocal microscopy was employed to study fXa binding to platelet thrombi formed in flowing whole blood under arterial conditions. Binding of fX/fXa to either vesicles or procoagulant platelets did not follow a traditional one-step reversible binding model. Their dissociation was a two-step process resulting in a plateau that was up to 10-fold greater than the saturation value observed in the association experiments. Computational modeling and experimental evidence suggested that this was caused by a combination of two-step association (mainly for fX) and multimerization on the membrane (mainly for fXa). Importantly, fX formed multimers with fXa, thereby improving its retention. The same binding/dissociation hysteresis was observed for annexin V known to form trimers on the membranes. Experiments with platelets from gray syndrome patients showed that alpha-granular factor Va provided an additional high-affinity binding site for fXa that did not affect the hysteresis. Confocal microscopy observation of fXa binding to platelet thrombi in a flow chamber and its wash-out confirmed that this phenomenon persisted under physiologically relevant conditions. This suggests its possible role of "locking" coagulation factors on the membrane and preventing their inhibition in plasma and removal from thrombi by flow.

  7. Moderate hypoxia followed by reoxygenation results in blood-brain barrier breakdown via oxidative stress-dependent tight-junction protein disruption.

    Science.gov (United States)

    Zehendner, Christoph M; Librizzi, Laura; Hedrich, Jana; Bauer, Nina M; Angamo, Eskedar A; de Curtis, Marco; Luhmann, Heiko J

    2013-01-01

    Re-canalization of cerebral vessels in ischemic stroke is pivotal to rescue dysfunctional brain areas that are exposed to moderate hypoxia within the penumbra from irreversible cell death. Goal of the present study was to evaluate the effect of moderate hypoxia followed by reoxygenation (MHR) on the evolution of reactive oxygen species (ROS) and blood-brain barrier (BBB) integrity in brain endothelial cells (BEC). BBB integrity was assessed in BEC in vitro and in microvessels of the guinea pig whole brain in situ preparation. Probes were exposed to MHR (2 hours 67-70 mmHg O2, 3 hours reoxygenation, BEC) or towards occlusion of the arteria cerebri media (MCAO) with or without subsequent reperfusion in the whole brain preparation. In vitro BBB integrity was evaluated using trans-endothelial electrical resistance (TEER) and transwell permeability assays. ROS in BEC were evaluated using 2',7'-dichlorodihydrofluorescein diacetate (DCF), MitoSox and immunostaining for nitrotyrosine. Tight-junction protein (TJ) integrity in BEC, stainings for nitrotyrosine and FITC-albumin extravasation in the guinea pig brain preparation were assessed by confocal microscopy. Diphenyleneiodonium (DPI) was used to investigate NADPH oxidase dependent ROS evolution and its effect on BBB parameters in BEC. MHR impaired TJ proteins zonula occludens 1 (ZO-1) and claudin 5 (Cl5), decreased TEER, and significantly increased cytosolic ROS in BEC. These events were blocked by the NADPH oxidase inhibitor DPI. MCAO with or without subsequent reoxygenation resulted in extravasation of FITC-albumin and ROS generation in the penumbra region of the guinea pig brain preparation and confirmed BBB damage. BEC integrity may be impaired through ROS in MHR on the level of TJ and the BBB is also functionally impaired in moderate hypoxic conditions followed by reperfusion in a complex guinea pig brain preparation. These findings suggest that the BBB is su