WorldWideScience

Sample records for random order exposures

  1. Ordered random variables theory and applications

    CERN Document Server

    Shahbaz, Muhammad Qaiser; Hanif Shahbaz, Saman; Al-Zahrani, Bander M

    2016-01-01

    Ordered Random Variables have attracted several authors. The basic building block of Ordered Random Variables is Order Statistics which has several applications in extreme value theory and ordered estimation. The general model for ordered random variables, known as Generalized Order Statistics has been introduced relatively recently by Kamps (1995).

  2. Cloud Macroscopic Organization: Order Emerging from Randomness

    Science.gov (United States)

    Yuan, Tianle

    2011-01-01

    Clouds play a central role in many aspects of the climate system and their forms and shapes are remarkably diverse. Appropriate representation of clouds in climate models is a major challenge because cloud processes span at least eight orders of magnitude in spatial scales. Here we show that there exists order in cloud size distribution of low-level clouds, and that it follows a power-law distribution with exponent gamma close to 2. gamma is insensitive to yearly variations in environmental conditions, but has regional variations and land-ocean contrasts. More importantly, we demonstrate this self-organizing behavior of clouds emerges naturally from a complex network model with simple, physical organizing principles: random clumping and merging. We also demonstrate symmetry between clear and cloudy skies in terms of macroscopic organization because of similar fundamental underlying organizing principles. The order in the apparently complex cloud-clear field thus has its root in random local interactions. Studying cloud organization with complex network models is an attractive new approach that has wide applications in climate science. We also propose a concept of cloud statistic mechanics approach. This approach is fully complementary to deterministic models, and the two approaches provide a powerful framework to meet the challenge of representing clouds in our climate models when working in tandem.

  3. Birth Order, Club Membership and Mass Media Exposure

    Science.gov (United States)

    Tomeh, Aida K.

    1976-01-01

    Examines the relationship between birth order, club membership and mass media exposure for women college students in Lebanon. Findings show the total membership rate and mass media consumption are higher among last born girls than first born. Birth order differences are explained in terms of the differential socialization of children. (Author)

  4. Quantitative measure of randomness and order for complete genomes

    Science.gov (United States)

    Kong, Sing-Guan; Fan, Wen-Lang; Chen, Hong-Da; Wigger, Jan; Torda, Andrew E.; Lee, H. C.

    2009-06-01

    We propose an order index, ϕ , which gives a quantitative measure of randomness and order of complete genomic sequences. It maps genomes to a number from 0 (random and of infinite length) to 1 (fully ordered) and applies regardless of sequence length. The 786 complete genomic sequences in GenBank were found to have ϕ values in a very narrow range, ϕg=0.031-0.015+0.028 . We show this implies that genomes are halfway toward being completely random, or, at the “edge of chaos.” We further show that artificial “genomes” converted from literary classics have ϕ ’s that almost exactly coincide with ϕg , but sequences of low information content do not. We infer that ϕg represents a high information-capacity “fixed point” in sequence space, and that genomes are driven to it by the dynamics of a robust growth and evolution process. We show that a growth process characterized by random segmental duplication can robustly drive genomes to the fixed point.

  5. Order-based representation in random networks of cortical neurons.

    Directory of Open Access Journals (Sweden)

    Goded Shahaf

    2008-11-01

    Full Text Available The wide range of time scales involved in neural excitability and synaptic transmission might lead to ongoing change in the temporal structure of responses to recurring stimulus presentations on a trial-to-trial basis. This is probably the most severe biophysical constraint on putative time-based primitives of stimulus representation in neuronal networks. Here we show that in spontaneously developing large-scale random networks of cortical neurons in vitro the order in which neurons are recruited following each stimulus is a naturally emerging representation primitive that is invariant to significant temporal changes in spike times. With a relatively small number of randomly sampled neurons, the information about stimulus position is fully retrievable from the recruitment order. The effective connectivity that makes order-based representation invariant to time warping is characterized by the existence of stations through which activity is required to pass in order to propagate further into the network. This study uncovers a simple invariant in a noisy biological network in vitro; its applicability under in vivo constraints remains to be seen.

  6. Ordering statistics of four random walkers on a line

    Science.gov (United States)

    Helenbrook, Brian; ben-Avraham, Daniel

    2018-05-01

    We study the ordering statistics of four random walkers on the line, obtaining a much improved estimate for the long-time decay exponent of the probability that a particle leads to time t , Plead(t ) ˜t-0.91287850 , and that a particle lags to time t (never assumes the lead), Plag(t ) ˜t-0.30763604 . Exponents of several other ordering statistics for N =4 walkers are obtained to eight-digit accuracy as well. The subtle correlations between n walkers that lag jointly, out of a field of N , are discussed: for N =3 there are no correlations and Plead(t ) ˜Plag(t) 2 . In contrast, our results rule out the possibility that Plead(t ) ˜Plag(t) 3 for N =4 , although the correlations in this borderline case are tiny.

  7. Long range order and giant components of quantum random graphs

    CERN Document Server

    Ioffe, D

    2006-01-01

    Mean field quantum random graphs give a natural generalization of classical Erd\\H{o}s-R\\'{e}nyi percolation model on complete graph $G_N$ with $p =\\beta /N$. Quantum case incorporates an additional parameter $\\lambda\\geq 0$, and the short-long range order transition should be studied in the $(\\beta ,\\lambda)$-quarter plane. In this work we explicitly compute the corresponding critical curve $\\gamma_c$, and derive results on two-point functions and sizes of connected components in both short and long range order regions. In this way the classical case corresponds to the limiting point $(\\beta_c ,0) = (1,0)$ on $\\gamma_c$.

  8. Magnetic and superconducting order in some random pseudobinary compounds

    International Nuclear Information System (INIS)

    Dongen, J.C.M. van.

    1982-01-01

    This thesis presents the results of a study on the magnetic and superconducting ordering phenomena in some random pseudobinary compounds. In the investigations ternary systems are utilised in which two of the elements form a binary intermetallic compound, e.g. PdH, GdCu and YCo 2 . A third element is then randomly substituted into one of the sublattices without changing the basic intermetallic compound structure. In chapter II a study is presented on the Kondo effect and spin-glass freezing of the magnetic impurities Cr, Mn, and Fe in superconducting palladium hydride. Chapter III contains a study on crystal structure transformations and magnetic ordering phenomena in GdCusub(1-x)Gasub(x) and related pseudobinary compounds. In Chapter IV experiments on the magnetic properties and the electrical resistivity of the transition metal Laves phase compounds Y(Cosub(1-x)Fesub(x)) 2 , Y(Irsub(1-x)Fesub(x)) 2 and Hf(Cosub(1-x)Fesub(x)) 2 are described. (Auth.)

  9. Fuzzy Random Walkers with Second Order Bounds: An Asymmetric Analysis

    Directory of Open Access Journals (Sweden)

    Georgios Drakopoulos

    2017-03-01

    Full Text Available Edge-fuzzy graphs constitute an essential modeling paradigm across a broad spectrum of domains ranging from artificial intelligence to computational neuroscience and social network analysis. Under this model, fundamental graph properties such as edge length and graph diameter become stochastic and as such they are consequently expressed in probabilistic terms. Thus, algorithms for fuzzy graph analysis must rely on non-deterministic design principles. One such principle is Random Walker, which is based on a virtual entity and selects either edges or, like in this case, vertices of a fuzzy graph to visit. This allows the estimation of global graph properties through a long sequence of local decisions, making it a viable strategy candidate for graph processing software relying on native graph databases such as Neo4j. As a concrete example, Chebyshev Walktrap, a heuristic fuzzy community discovery algorithm relying on second order statistics and on the teleportation of the Random Walker, is proposed and its performance, expressed in terms of community coherence and number of vertex visits, is compared to the previously proposed algorithms of Markov Walktrap, Fuzzy Walktrap, and Fuzzy Newman–Girvan. In order to facilitate this comparison, a metric based on the asymmetric metrics of Tversky index and Kullback–Leibler divergence is used.

  10. Order out of Randomness: Self-Organization Processes in Astrophysics

    Science.gov (United States)

    Aschwanden, Markus J.; Scholkmann, Felix; Béthune, William; Schmutz, Werner; Abramenko, Valentina; Cheung, Mark C. M.; Müller, Daniel; Benz, Arnold; Chernov, Guennadi; Kritsuk, Alexei G.; Scargle, Jeffrey D.; Melatos, Andrew; Wagoner, Robert V.; Trimble, Virginia; Green, William H.

    2018-03-01

    Self-organization is a property of dissipative nonlinear processes that are governed by a global driving force and a local positive feedback mechanism, which creates regular geometric and/or temporal patterns, and decreases the entropy locally, in contrast to random processes. Here we investigate for the first time a comprehensive number of (17) self-organization processes that operate in planetary physics, solar physics, stellar physics, galactic physics, and cosmology. Self-organizing systems create spontaneous " order out of randomness", during the evolution from an initially disordered system to an ordered quasi-stationary system, mostly by quasi-periodic limit-cycle dynamics, but also by harmonic (mechanical or gyromagnetic) resonances. The global driving force can be due to gravity, electromagnetic forces, mechanical forces (e.g., rotation or differential rotation), thermal pressure, or acceleration of nonthermal particles, while the positive feedback mechanism is often an instability, such as the magneto-rotational (Balbus-Hawley) instability, the convective (Rayleigh-Bénard) instability, turbulence, vortex attraction, magnetic reconnection, plasma condensation, or a loss-cone instability. Physical models of astrophysical self-organization processes require hydrodynamic, magneto-hydrodynamic (MHD), plasma, or N-body simulations. Analytical formulations of self-organizing systems generally involve coupled differential equations with limit-cycle solutions of the Lotka-Volterra or Hopf-bifurcation type.

  11. Complexities of sibling analysis when exposures and outcomes change with time and birth order.

    Science.gov (United States)

    Sudan, Madhuri; Kheifets, Leeka I; Arah, Onyebuchi A; Divan, Hozefa A; Olsen, Jørn

    2014-01-01

    In this study, we demonstrate the complexities of performing a sibling analysis with a re-examination of associations between cell phone exposures and behavioral problems observed previously in the Danish National Birth Cohort. Children (52,680; including 5441 siblings) followed up to age 7 were included. We examined differences in exposures and behavioral problems between siblings and non-siblings and by birth order and birth year. We estimated associations between cell phone exposures and behavioral problems while accounting for the random family effect among siblings. The association of behavioral problems with both prenatal and postnatal exposure differed between siblings (odds ratio (OR): 1.07; 95% confidence interval (CI): 0.69-1.66) and non-siblings (OR: 1.54; 95% CI: 1.36-1.74) and within siblings by birth order; the association was strongest for first-born siblings (OR: 1.72; 95% CI: 0.86-3.42) and negative for later-born siblings (OR: 0.63; 95% CI: 0.31-1.25), which may be because of increases in cell phone use with later birth year. Sibling analysis can be a powerful tool for (partially) accounting for confounding by invariant unmeasured within-family factors, but it cannot account for uncontrolled confounding by varying family-level factors, such as those that vary with time and birth order.

  12. Ground-state properties of ordered, partially ordered, and random Cu-Au and Ni-Pt alloys

    DEFF Research Database (Denmark)

    Ruban, Andrei; Abrikosov, I. A.; Skriver, Hans Lomholt

    1995-01-01

    We have studied the ground-state properties of ordered, partially ordered, and random Cu-Au and Ni-Pt alloys at the stoichiometric 1/4, 1/2, and 3/4 compositions in the framework of the multisublattice single-site (SS) coherent potential approximation (CPA). Charge-transfer effects in the random ...... for the ordered alloys are in good agreement with experimental data. For all the alloys the calculated ordering energy and the equilibrium lattices parameters are found to be almost exact quadratic functions of the long-range-order parameter....... and the partially ordered alloys are included in the screened impurity model. The prefactor in the Madelung energy is determined by the requirement that the total energy obtained in direct SS CPA calculations should equal the total energy given by the Connolly-Williams expansion based on Green’s function...

  13. On mean square displacement behaviors of anomalous diffusions with variable and random orders

    International Nuclear Information System (INIS)

    Sun Hongguang; Chen Wen; Sheng Hu; Chen Yangquan

    2010-01-01

    Mean square displacement (MSD) is used to characterize anomalous diffusion. Recently, models of anomalous diffusion with variable-order and random-order were proposed, but no MSD analysis has been given so far. The purpose of this Letter is to offer a concise derivation of MSD functions for the variable-order model and the random-order model. Numerical results are presented to illustrate the analytical results. In addition, we show how to establish a variable-random-order model for a given MSD function which has clear application potentials.

  14. Complexities of sibling analysis when exposures and outcomes change with time and birth order

    OpenAIRE

    Sudan, M; Kheifets, LI; Arah, OA; Divan, HA; Olsen, J

    2014-01-01

    In this study, we demonstrate the complexities of performing a sibling analysis with a re-examination of associations between cell phone exposures and behavioral problems observed previously in the Danish National Birth Cohort. Children (52,680; including 5441 siblings) followed up to age 7 were included. We examined differences in exposures and behavioral problems between siblings and non-siblings and by birth order and birth year. We estimated associations between cell phone exposures and b...

  15. Piecewise linearisation of the first order loss function for families of arbitrarily distributed random variables

    NARCIS (Netherlands)

    Rossi, R.; Hendrix, E.M.T.

    2014-01-01

    We discuss the problem of computing optimal linearisation parameters for the first order loss function of a family of arbitrarily distributed random variable. We demonstrate that, in contrast to the problem in which parameters must be determined for the loss function of a single random variable,

  16. A stochastic collocation method for the second order wave equation with a discontinuous random speed

    KAUST Repository

    Motamed, Mohammad; Nobile, Fabio; Tempone, Raul

    2012-01-01

    In this paper we propose and analyze a stochastic collocation method for solving the second order wave equation with a random wave speed and subjected to deterministic boundary and initial conditions. The speed is piecewise smooth in the physical

  17. Robust Fuzzy Control for Fractional-Order Uncertain Hydroturbine Regulating System with Random Disturbances

    Directory of Open Access Journals (Sweden)

    Fengjiao Wu

    2016-01-01

    Full Text Available The robust fuzzy control for fractional-order hydroturbine regulating system is studied in this paper. First, the more practical fractional-order hydroturbine regulating system with uncertain parameters and random disturbances is presented. Then, on the basis of interval matrix theory and fractional-order stability theorem, a fuzzy control method is proposed for fractional-order hydroturbine regulating system, and the stability condition is expressed as a group of linear matrix inequalities. Furthermore, the proposed method has good robustness which can process external random disturbances and uncertain parameters. Finally, the validity and superiority are proved by the numerical simulations.

  18. Robust Fuzzy Control for Fractional-Order Uncertain Hydroturbine Regulating System with Random Disturbances

    OpenAIRE

    Fengjiao Wu; Guitao Zhang; Zhengzhong Wang

    2016-01-01

    The robust fuzzy control for fractional-order hydroturbine regulating system is studied in this paper. First, the more practical fractional-order hydroturbine regulating system with uncertain parameters and random disturbances is presented. Then, on the basis of interval matrix theory and fractional-order stability theorem, a fuzzy control method is proposed for fractional-order hydroturbine regulating system, and the stability condition is expressed as a group of linear matrix inequalities. ...

  19. First-order corrections to random-phase approximation GW calculations in silicon and diamond

    NARCIS (Netherlands)

    Ummels, R.T.M.; Bobbert, P.A.; van Haeringen, W.

    1998-01-01

    We report on ab initio calculations of the first-order corrections in the screened interaction W to the random-phase approximation polarizability and to the GW self-energy, using a noninteracting Green's function, for silicon and diamond. It is found that the first-order vertex and self-consistency

  20. Estimation methods with ordered exposure subject to measurement error and missingness in semi-ecological design

    Directory of Open Access Journals (Sweden)

    Kim Hyang-Mi

    2012-09-01

    Full Text Available Abstract Background In epidemiological studies, it is often not possible to measure accurately exposures of participants even if their response variable can be measured without error. When there are several groups of subjects, occupational epidemiologists employ group-based strategy (GBS for exposure assessment to reduce bias due to measurement errors: individuals of a group/job within study sample are assigned commonly to the sample mean of exposure measurements from their group in evaluating the effect of exposure on the response. Therefore, exposure is estimated on an ecological level while health outcomes are ascertained for each subject. Such study design leads to negligible bias in risk estimates when group means are estimated from ‘large’ samples. However, in many cases, only a small number of observations are available to estimate the group means, and this causes bias in the observed exposure-disease association. Also, the analysis in a semi-ecological design may involve exposure data with the majority missing and the rest observed with measurement errors and complete response data collected with ascertainment. Methods In workplaces groups/jobs are naturally ordered and this could be incorporated in estimation procedure by constrained estimation methods together with the expectation and maximization (EM algorithms for regression models having measurement error and missing values. Four methods were compared by a simulation study: naive complete-case analysis, GBS, the constrained GBS (CGBS, and the constrained expectation and maximization (CEM. We illustrated the methods in the analysis of decline in lung function due to exposures to carbon black. Results Naive and GBS approaches were shown to be inadequate when the number of exposure measurements is too small to accurately estimate group means. The CEM method appears to be best among them when within each exposure group at least a ’moderate’ number of individuals have their

  1. Effects of randomness on chaos and order of coupled logistic maps

    International Nuclear Information System (INIS)

    Savi, Marcelo A.

    2007-01-01

    Natural systems are essentially nonlinear being neither completely ordered nor completely random. These nonlinearities are responsible for a great variety of possibilities that includes chaos. On this basis, the effect of randomness on chaos and order of nonlinear dynamical systems is an important feature to be understood. This Letter considers randomness as fluctuations and uncertainties due to noise and investigates its influence in the nonlinear dynamical behavior of coupled logistic maps. The noise effect is included by adding random variations either to parameters or to state variables. Besides, the coupling uncertainty is investigated by assuming tinny values for the connection parameters, representing the idea that all Nature is, in some sense, weakly connected. Results from numerical simulations show situations where noise alters the system nonlinear dynamics

  2. An AES chip with DPA resistance using hardware-based random order execution

    International Nuclear Information System (INIS)

    Yu Bo; Li Xiangyu; Chen Cong; Sun Yihe; Wu Liji; Zhang Xiangmin

    2012-01-01

    This paper presents an AES (advanced encryption standard) chip that combats differential power analysis (DPA) side-channel attack through hardware-based random order execution. Both decryption and encryption procedures of an AES are implemented on the chip. A fine-grained dataflow architecture is proposed, which dynamically exploits intrinsic byte-level independence in the algorithm. A novel circuit called an HMF (Hold-Match-Fetch) unit is proposed for random control, which randomly sets execution orders for concurrent operations. The AES chip was manufactured in SMIC 0.18 μm technology. The average energy for encrypting one group of plain texts (128 bits secrete keys) is 19 nJ. The core area is 0.43 mm 2 . A sophisticated experimental setup was built to test the DPA resistance. Measurement-based experimental results show that one byte of a secret key cannot be disclosed from our chip under random mode after 64000 power traces were used in the DPA attack. Compared with the corresponding fixed order execution, the hardware based random order execution is improved by at least 21 times the DPA resistance. (semiconductor integrated circuits)

  3. An AES chip with DPA resistance using hardware-based random order execution

    Science.gov (United States)

    Bo, Yu; Xiangyu, Li; Cong, Chen; Yihe, Sun; Liji, Wu; Xiangmin, Zhang

    2012-06-01

    This paper presents an AES (advanced encryption standard) chip that combats differential power analysis (DPA) side-channel attack through hardware-based random order execution. Both decryption and encryption procedures of an AES are implemented on the chip. A fine-grained dataflow architecture is proposed, which dynamically exploits intrinsic byte-level independence in the algorithm. A novel circuit called an HMF (Hold-Match-Fetch) unit is proposed for random control, which randomly sets execution orders for concurrent operations. The AES chip was manufactured in SMIC 0.18 μm technology. The average energy for encrypting one group of plain texts (128 bits secrete keys) is 19 nJ. The core area is 0.43 mm2. A sophisticated experimental setup was built to test the DPA resistance. Measurement-based experimental results show that one byte of a secret key cannot be disclosed from our chip under random mode after 64000 power traces were used in the DPA attack. Compared with the corresponding fixed order execution, the hardware based random order execution is improved by at least 21 times the DPA resistance.

  4. Variances as order parameter and complexity measure for random Boolean networks

    International Nuclear Information System (INIS)

    Luque, Bartolo; Ballesteros, Fernando J; Fernandez, Manuel

    2005-01-01

    Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We compute its value analytically and compare it with the results of numerical experiments. Finally, we propose a complexity measure based on the compromise between temporal and spatial variances. This new order parameter and its related complexity measure can be easily applied to other complex systems

  5. Variances as order parameter and complexity measure for random Boolean networks

    Energy Technology Data Exchange (ETDEWEB)

    Luque, Bartolo [Departamento de Matematica Aplicada y EstadIstica, Escuela Superior de Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain); Ballesteros, Fernando J [Observatori Astronomic, Universitat de Valencia, Ed. Instituts d' Investigacio, Pol. La Coma s/n, E-46980 Paterna, Valencia (Spain); Fernandez, Manuel [Departamento de Matematica Aplicada y EstadIstica, Escuela Superior de Ingenieros Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain)

    2005-02-04

    Several order parameters have been considered to predict and characterize the transition between ordered and disordered phases in random Boolean networks, such as the Hamming distance between replicas or the stable core, which have been successfully used. In this work, we propose a natural and clear new order parameter: the temporal variance. We compute its value analytically and compare it with the results of numerical experiments. Finally, we propose a complexity measure based on the compromise between temporal and spatial variances. This new order parameter and its related complexity measure can be easily applied to other complex systems.

  6. Residual and Past Entropy for Concomitants of Ordered Random Variables of Morgenstern Family

    Directory of Open Access Journals (Sweden)

    M. M. Mohie EL-Din

    2015-01-01

    Full Text Available For a system, which is observed at time t, the residual and past entropies measure the uncertainty about the remaining and the past life of the distribution, respectively. In this paper, we have presented the residual and past entropy of Morgenstern family based on the concomitants of the different types of generalized order statistics (gos and give the linear transformation of such model. Characterization results for these dynamic entropies for concomitants of ordered random variables have been considered.

  7. Modular Transformations, Order-Chaos Transitions and Pseudo-Random Number Generation

    Science.gov (United States)

    Bonelli, Antonio; Ruffo, Stefano

    Successive pairs of pseudo-random numbers generated by standard linear congruential transformations display ordered patterns of parallel lines. We study the "ordered" and "chaotic" distribution of such pairs by solving the eigenvalue problem for two-dimensional modular transformations over integers. We conjecture that the optimal uniformity for pair distribution is obtained when the slope of linear modular eigenspaces takes the value n opt =maxint (p/√ {p-1}), where p is a prime number. We then propose a new generator of pairs of independent pseudo-random numbers, which realizes an optimal uniform distribution (in the "statistical" sense) of points on the unit square (0, 1] × (0, 1]. The method can be easily generalized to the generation of k-tuples of random numbers (with k>2).

  8. Simulation-based production planning for engineer-to-order systems with random yield

    NARCIS (Netherlands)

    Akcay, Alp; Martagan, Tugce

    2018-01-01

    We consider an engineer-to-order production system with unknown yield. We model the yield as a random variable which represents the percentage output obtained from one unit of production quantity. We develop a beta-regression model in which the mean value of the yield depends on the unique

  9. Order of exposure to pleasant and unpleasant odors affects autonomic nervous system response.

    Science.gov (United States)

    Horii, Yuko; Nagai, Katsuya; Nakashima, Toshihiro

    2013-04-15

    When mammals are exposed to an odor, that odor is expected to elicit a physiological response in the autonomic nervous system. An unpleasant aversive odor causes non-invasive stress, while a pleasant odor promotes healing and relaxation in mammals. We hypothesized that pleasant odors might reduce a stress response previously induced by an aversive predator odor. Rats were thus exposed to pleasant and unpleasant odors in different orders to determine whether the order of odor exposure had an effect on the physiological response in the autonomic nervous system. The first trial examined autonomic nerve activity via sympathetic and parasympathetic nerve response while the second trial examined body temperature response. Initial exposure to a pleasant odor elicited a positive response and secondary exposure to an unpleasant odor elicited a negative response, as expected. However, we found that while initial exposure to an unpleasant odor elicited a negative stress response, subsequent secondary exposure to a pleasant odor not only did not alleviate that negative response, but actually amplified it. These findings were consistent for both the autonomic nerve activity response trial and the body temperature response trial. The trial results suggest that exposure to specific odors does not necessarily result in the expected physiological response and that the specific order of exposure plays an important role. Our study should provide new insights into our understanding of the physiological response in the autonomic nervous system related to odor memory and discrimination and point to areas that require further research. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Estimating overall exposure effects for the clustered and censored outcome using random effect Tobit regression models.

    Science.gov (United States)

    Wang, Wei; Griswold, Michael E

    2016-11-30

    The random effect Tobit model is a regression model that accommodates both left- and/or right-censoring and within-cluster dependence of the outcome variable. Regression coefficients of random effect Tobit models have conditional interpretations on a constructed latent dependent variable and do not provide inference of overall exposure effects on the original outcome scale. Marginalized random effects model (MREM) permits likelihood-based estimation of marginal mean parameters for the clustered data. For random effect Tobit models, we extend the MREM to marginalize over both the random effects and the normal space and boundary components of the censored response to estimate overall exposure effects at population level. We also extend the 'Average Predicted Value' method to estimate the model-predicted marginal means for each person under different exposure status in a designated reference group by integrating over the random effects and then use the calculated difference to assess the overall exposure effect. The maximum likelihood estimation is proposed utilizing a quasi-Newton optimization algorithm with Gauss-Hermite quadrature to approximate the integration of the random effects. We use these methods to carefully analyze two real datasets. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Magnetic ordering at low temperatures in some random superconducting and insulating compounds

    International Nuclear Information System (INIS)

    Hueser, D.

    1985-01-01

    This thesis presents the results of some investigations on the magnetic ordering phenomena in some random superconducting and insulating materials. The results are described of an investigation of the coexistence of superconductivity and random magnetic freezing in (Th,Nd)Ru 2 . On the basis of various measurements as function of temperature and external magnetic field the author found that spin glass-like freezing can occur far below the superconductivity and even that a sample may re-enter the superconducting state below a freezing temperature. Associated with the isothermal remanent magnetization of a random magnetic material he observed strong anomalies in the critical field versus temperature curves. Also a magnetic field memory effect has been found. (Auth.)

  12. Virtual reality exposure therapy for social anxiety disorder: a randomized controlled trial.

    Science.gov (United States)

    Anderson, Page L; Price, Matthew; Edwards, Shannan M; Obasaju, Mayowa A; Schmertz, Stefan K; Zimand, Elana; Calamaras, Martha R

    2013-10-01

    This is the first randomized trial comparing virtual reality exposure therapy to in vivo exposure for social anxiety disorder. Participants with a principal diagnosis of social anxiety disorder who identified public speaking as their primary fear (N = 97) were recruited from the community, resulting in an ethnically diverse sample (M age = 39 years) of mostly women (62%). Participants were randomly assigned to and completed 8 sessions of manualized virtual reality exposure therapy, exposure group therapy, or wait list. Standardized self-report measures were collected at pretreatment, posttreatment, and 12-month follow-up, and process measures were collected during treatment. A standardized speech task was delivered at pre- and posttreatment, and diagnostic status was reassessed at 3-month follow-up. Analysis of covariance showed that, relative to wait list, people completing either active treatment significantly improved on all but one measure (length of speech for exposure group therapy and self-reported fear of negative evaluation for virtual reality exposure therapy). At 12-month follow-up, people showed significant improvement from pretreatment on all measures. There were no differences between the active treatments on any process or outcome measure at any time, nor differences on achieving partial or full remission. Virtual reality exposure therapy is effective for treating social fears, and improvement is maintained for 1 year. Virtual reality exposure therapy is equally effective as exposure group therapy; further research with a larger sample is needed, however, to better control and statistically test differences between the treatments.

  13. The Schwinger Dyson equations and the algebra of constraints of random tensor models at all orders

    International Nuclear Information System (INIS)

    Gurau, Razvan

    2012-01-01

    Random tensor models for a generic complex tensor generalize matrix models in arbitrary dimensions and yield a theory of random geometries. They support a 1/N expansion dominated by graphs of spherical topology. Their Schwinger Dyson equations, generalizing the loop equations of matrix models, translate into constraints satisfied by the partition function. The constraints have been shown, in the large N limit, to close a Lie algebra indexed by colored rooted D-ary trees yielding a first generalization of the Virasoro algebra in arbitrary dimensions. In this paper we complete the Schwinger Dyson equations and the associated algebra at all orders in 1/N. The full algebra of constraints is indexed by D-colored graphs, and the leading order D-ary tree algebra is a Lie subalgebra of the full constraints algebra.

  14. Random textures of the order parameter of superfluid sup 3 He-B in aerogel

    CERN Document Server

    Fomin, Yu A

    2002-01-01

    The scheme for describing the properties of the superfluid sup 3 He in the aerogel is proposed in accordance with the Ginzburg and Landau theory. The aerogel effect on the order parameter is described by the random tensor field. This field exerts desorientation effect on the order parameter in the sup 3 He A-phase, but it does not influence the order parameter orientation in the B-phase, if there is no magnetic field. The change in the order parameter texture, originating in the B-phase in the aerogel in the magnetic field, is considered. Fluctuations of the sup 3 He-B anisotropy axis direction are correlated on the length, inversely proportional to the field intensity and having the macroscopic scale

  15. Is Exposure Necessary? A Randomized Clinical Trial of Interpersonal Psychotherapy for PTSD

    Science.gov (United States)

    Markowitz, John C.; Petkova, Eva; Neria, Yuval; Van Meter, Page E.; Zhao, Yihong; Hembree, Elizabeth; Lovell, Karina; Biyanova, Tatyana; Marshall, Randall D.

    2015-01-01

    Background Exposure to trauma reminders has been considered imperative in psychotherapy for posttraumatic stress disorder (PTSD). No treatment benefits all patients, however. We tested Interpersonal Psychotherapy, which has demonstrated antidepressant efficacy and showed promise in pilot PTSD research, as a non-exposure-based, non-cognitive behavioral PTSD treatment. Methods A randomized, fourteen-week trial compared Interpersonal Psychotherapy; Prolonged Exposure, an exposure-based exemplar; and Relaxation Therapy, an active control psychotherapy. Subjects were 110 unmedicated patients having DSM-IV chronic PTSD and Clinician-Administered PTSD Scale (CAPS) score >50. Randomization stratified for comorbid major depression. We hypothesized Interpersonal Psychotherapy would be no more than minimally inferior (CAPS difference 30% CAPS improvement) were: Interpersonal Psychotherapy 63%, Prolonged Exposure 47%, Relaxation Therapy 38% (n.s.). Interpersonal psychotherapy and Prolonged Exposure CAPS outcome differed by 5.5 points (n.s.); the null hypothesis of more than minimal Interpersonal Psychotherapy inferiority was rejected (p=0.035). Patients with comorbid major depression dropped out from Prolonged Exposure nine times more than non-depressed Prolonged Exposure patients. Interpersonal Psychotherapy and Prolonged Exposure improved quality of life and social functioning more than Relaxation Therapy. Conclusions This first controlled study of individual Interpersonal Psychotherapy for PTSD demonstrated non-inferiority to the “gold standard” PTSD treatment. Interpersonal Psychotherapy had (non-significantly) lower attrition and higher response rates than Prolonged Exposure. Contradicting a widespread clinical belief, PTSD treatment may not require cognitive behavioral exposure to trauma reminders. Moreover, as differential therapeutics, patients with comorbid major depression may fare better in Interpersonal Psychotherapy than Prolonged Exposure. PMID:25677355

  16. Defining Higher-Order Turbulent Moment Closures with an Artificial Neural Network and Random Forest

    Science.gov (United States)

    McGibbon, J.; Bretherton, C. S.

    2017-12-01

    Unresolved turbulent advection and clouds must be parameterized in atmospheric models. Modern higher-order closure schemes depend on analytic moment closure assumptions that diagnose higher-order moments in terms of lower-order ones. These are then tested against Large-Eddy Simulation (LES) higher-order moment relations. However, these relations may not be neatly analytic in nature. Rather than rely on an analytic higher-order moment closure, can we use machine learning on LES data itself to define a higher-order moment closure?We assess the ability of a deep artificial neural network (NN) and random forest (RF) to perform this task using a set of observationally-based LES runs from the MAGIC field campaign. By training on a subset of 12 simulations and testing on remaining simulations, we avoid over-fitting the training data.Performance of the NN and RF will be assessed and compared to the Analytic Double Gaussian 1 (ADG1) closure assumed by Cloudy Layers Unified By Binormals (CLUBB), a higher-order turbulence closure currently used in the Community Atmosphere Model (CAM). We will show that the RF outperforms the NN and the ADG1 closure for the MAGIC cases within this diagnostic framework. Progress and challenges in using a diagnostic machine learning closure within a prognostic cloud and turbulence parameterization will also be discussed.

  17. SOERP, Statistics and 2. Order Error Propagation for Function of Random Variables

    International Nuclear Information System (INIS)

    Cox, N. D.; Miller, C. F.

    1985-01-01

    1 - Description of problem or function: SOERP computes second-order error propagation equations for the first four moments of a function of independently distributed random variables. SOERP was written for a rigorous second-order error propagation of any function which may be expanded in a multivariable Taylor series, the input variables being independently distributed. The required input consists of numbers directly related to the partial derivatives of the function, evaluated at the nominal values of the input variables and the central moments of the input variables from the second through the eighth. 2 - Method of solution: The development of equations for computing the propagation of errors begins by expressing the function of random variables in a multivariable Taylor series expansion. The Taylor series expansion is then truncated, and statistical operations are applied to the series in order to obtain equations for the moments (about the origin) of the distribution of the computed value. If the Taylor series is truncated after powers of two, the procedure produces second-order error propagation equations. 3 - Restrictions on the complexity of the problem: The maximum number of component variables allowed is 30. The IBM version will only process one set of input data per run

  18. An MGF-based unified framework to determine the joint statistics of partial sums of ordered random variables

    KAUST Repository

    Nam, Sungsik; Alouini, Mohamed-Slim; Yang, Hongchuan

    2010-01-01

    Order statistics find applications in various areas of communications and signal processing. In this paper, we introduce an unified analytical framework to determine the joint statistics of partial sums of ordered random variables (RVs

  19. Numerical solution of second-order stochastic differential equations with Gaussian random parameters

    Directory of Open Access Journals (Sweden)

    Rahman Farnoosh

    2014-07-01

    Full Text Available In this paper, we present the numerical solution of ordinary differential equations (or SDEs, from each orderespecially second-order with time-varying and Gaussian random coefficients. We indicate a complete analysisfor second-order equations in specially case of scalar linear second-order equations (damped harmonicoscillators with additive or multiplicative noises. Making stochastic differential equations system from thisequation, it could be approximated or solved numerically by different numerical methods. In the case oflinear stochastic differential equations system by Computing fundamental matrix of this system, it could becalculated based on the exact solution of this system. Finally, this stochastic equation is solved by numericallymethod like E.M. and Milstein. Also its Asymptotic stability and statistical concepts like expectationand variance of solutions are discussed.

  20. Neutron Transport in Spatially Random Media: An Assessment of the Accuracy of First Order Smoothing

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    2000-01-01

    A formalism has been developed for studying the transmission of neutrons through a spatially stochastic medium. The stochastic components are represented by absorbing plates of randomly varying strength and random position. This type of geometry enables the Feinberg-Galanin-Horning method to be employed and leads to the solution of a coupled set of linear equations for the flux at the plate positions. The matrix of the coefficients contains members that are random and these are solved by simulation. That is, the strength and plate positions are sampled from uniform distributions and the equations solved many times (in this case 10 5 simulations are carried out). Probability distributions for the plate transmission and reflection factors are constructed from which the mean and variance can be computed.These essentially exact solutions enable closure approximations to be assessed for accuracy. To this end, we have compared the mean and variance obtained from the first order smoothing approximation of Keller with the exact results and have found excellent agreement for the mean values but note deviations of up to 40% for the variance. Nevertheless, for the problems considered here, first order smoothing appears to be of practical value and is very efficient numerically in comparison with simulation

  1. Implementation of an Automatic Stop Order and Initial Antibiotic Exposure in Very Low Birth Weight Infants.

    Science.gov (United States)

    Tolia, Veeral N; Desai, Sujata; Qin, Huanying; Rayburn, Polli D; Poon, Grace; Murthy, Karna; Ellsbury, Dan L; Chiruvolu, Arpitha

    2017-01-01

    Objective  To evaluate if an antibiotic automatic stop order (ASO) changed early antibiotic exposure (use in the first 7 days of life) or clinical outcomes in very low birth weight (VLBW) infants. Study Design  We compared birth characteristics, early antibiotic exposure, morbidity, and mortality data in VLBW infants (with birth weight  48 hours. Secondary outcomes included mortality, early mortality, early onset sepsis (EOS), and necrotizing enterocolitis. Results  Birth characteristics were similar between the two groups. We observed reduced median antibiotic exposure (pre-ASO: 6.5 DOT vs. Post-ASO: 4 DOT; p   48 hours (63.4 vs. 41.3%; p  < 0.001). There were no differences in mortality (12.1 vs 10.2%; p  = 0.44), early mortality, or other reported morbidities. EOS accounted for less than 10% of early antibiotic use. Conclusion  Early antibiotic exposure was reduced after the implementation of an ASO without changes in observed outcomes. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  2. Single exposure optically compressed imaging and visualization using random aperture coding

    Energy Technology Data Exchange (ETDEWEB)

    Stern, A [Electro Optical Unit, Ben Gurion University of the Negev, Beer-Sheva 84105 (Israel); Rivenson, Yair [Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer-Sheva 84105 (Israel); Javidi, Bahrain [Department of Electrical and Computer Engineering, University of Connecticut, Storrs, Connecticut 06269-1157 (United States)], E-mail: stern@bgu.ac.il

    2008-11-01

    The common approach in digital imaging follows the sample-then-compress framework. According to this approach, in the first step as many pixels as possible are captured and in the second step the captured image is compressed by digital means. The recently introduced theory of compressed sensing provides the mathematical foundation necessary to combine these two steps in a single one, that is, to compress the information optically before it is recorded. In this paper we overview and extend an optical implementation of compressed sensing theory that we have recently proposed. With this new imaging approach the compression is accomplished inherently in the optical acquisition step. The primary feature of this imaging approach is a randomly encoded aperture realized by means of a random phase screen. The randomly encoded aperture implements random projection of the object field in the image plane. Using a single exposure, a randomly encoded image is captured which can be decoded by proper decoding algorithm.

  3. Cognitive Therapy Versus Exposure and Applied Relaxation in Social Phobia: A Randomized Controlled Trial

    Science.gov (United States)

    Clark, David M.; Ehlers, Anke; Hackmann, Ann; McManus, Freda; Fennell, Melanie; Grey, Nick; Waddington, Louise; Wild, Jennifer

    2006-01-01

    A new cognitive therapy (CT) program was compared with an established behavioral treatment. Sixty-two patients meeting Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) criteria for social phobia were randomly assigned to CT, exposure plus applied relaxation (EXP = AR), or wait-list (WAIT). CT…

  4. Radiation-induced segregation behavior in random and ordered face-centered cubic materials

    International Nuclear Information System (INIS)

    Bui, T.X.; Robertson, I.M.; Klatt, J.L.; Averback, R.S.; Kirk, M.A.

    1993-01-01

    Radiation-induced segregation has been studied in random solid solution alloys Ni-10%Al and Ni-6%Si, and in the ordered (L1 2 structure) intermetallics Ni 3 Si and Ni 3 Al. These materials were irradiated with 2 MeV He + ions at a temperature between 0.45 and 0.55T m and at an ion dose rate of approximately 1x10 -4 dpa per second. Subsequent Auger Electron Spectroscopy analysis showed that silicon segregated to the surface in the Ni-6% Si and Ni 3 Si alloys, and aluminum segregated away from the near surface region in the Ni-10% Al alloy. The Ni 3 Al samples exhibited no detectable segregation with respect to depth from the sample surface. The mechanisms that may give rise to this resistance to radiation induced segregation will be examined in terms of the mobility of the alloying constituents, ordering energies and atomic sizes. (orig.)

  5. Will electrical cyber-physical interdependent networks undergo first-order transition under random attacks?

    Science.gov (United States)

    Ji, Xingpei; Wang, Bo; Liu, Dichen; Dong, Zhaoyang; Chen, Guo; Zhu, Zhenshan; Zhu, Xuedong; Wang, Xunting

    2016-10-01

    Whether the realistic electrical cyber-physical interdependent networks will undergo first-order transition under random failures still remains a question. To reflect the reality of Chinese electrical cyber-physical system, the "partial one-to-one correspondence" interdependent networks model is proposed and the connectivity vulnerabilities of three realistic electrical cyber-physical interdependent networks are analyzed. The simulation results show that due to the service demands of power system the topologies of power grid and its cyber network are highly inter-similar which can effectively avoid the first-order transition. By comparing the vulnerability curves between electrical cyber-physical interdependent networks and its single-layer network, we find that complex network theory is still useful in the vulnerability analysis of electrical cyber-physical interdependent networks.

  6. Role of Educational Exposure in the Association Between Myopia and Birth Order.

    Science.gov (United States)

    Guggenheim, Jeremy A; Williams, Cathy

    2015-12-01

    Visual impairment due to myopia is an important public health issue. A prior analysis of population-based cohorts aged 15 to 22 years recruited from the United Kingdom and Israel suggested myopia and high myopia were approximately 10% more common in first-born compared with later-born children. To examine whether myopia was associated with birth order in an earlier generation than studied previously and, if so, whether the association was attenuated after adjusting for education exposure, as predicted by the hypothesis that the education of children with later birth orders is less intense. Cross-sectional study of UK Biobank participants recruited from 2006 to 2010. Analysis was restricted to participants aged 40 to 69 years who had a vision assessment, self-reported white ethnicity, and no history of eye disorders (N = 89,120). Myopia and high myopia were defined as autorefraction of -0.75 diopters (D) or less and -6.00 D or less, respectively. Birth order and information on potential confounders including highest educational qualification ascertained using a structured questionnaire. Odds ratios (ORs) for myopia and high myopia by birth order, using logistic regression and adjusting for age and sex (model 1) or age, sex, and highest educational qualification (model 2). In model 1 (no adjustment for education), birth order was associated with both myopia and high myopia (eg, comparing first- vs second-born individuals; OR, 1.12; 95% CI, 1.08-1.16; P = 1.40E-11 and OR, 1.21; 95% CI, 1.11-1.30; P = 3.60E-06 for myopia and high myopia, respectively). The risk for myopia became progressively lower for later birth orders, suggesting a dose response. In model 2 (after adjusting for education), the effect sizes were attenuated by approximately 25% (OR, 1.09; 95% CI, 1.05-1.12; P = 1.30E-06 and OR, 1.15; 95% CI, 1.06-1.25; P = 4.60E-04 for myopia and high myopia, respectively) and the apparent dose response was abolished. These data suggest that the

  7. A stochastic collocation method for the second order wave equation with a discontinuous random speed

    KAUST Repository

    Motamed, Mohammad

    2012-08-31

    In this paper we propose and analyze a stochastic collocation method for solving the second order wave equation with a random wave speed and subjected to deterministic boundary and initial conditions. The speed is piecewise smooth in the physical space and depends on a finite number of random variables. The numerical scheme consists of a finite difference or finite element method in the physical space and a collocation in the zeros of suitable tensor product orthogonal polynomials (Gauss points) in the probability space. This approach leads to the solution of uncoupled deterministic problems as in the Monte Carlo method. We consider both full and sparse tensor product spaces of orthogonal polynomials. We provide a rigorous convergence analysis and demonstrate different types of convergence of the probability error with respect to the number of collocation points for full and sparse tensor product spaces and under some regularity assumptions on the data. In particular, we show that, unlike in elliptic and parabolic problems, the solution to hyperbolic problems is not in general analytic with respect to the random variables. Therefore, the rate of convergence may only be algebraic. An exponential/fast rate of convergence is still possible for some quantities of interest and for the wave solution with particular types of data. We present numerical examples, which confirm the analysis and show that the collocation method is a valid alternative to the more traditional Monte Carlo method for this class of problems. © 2012 Springer-Verlag.

  8. Measuring order in disordered systems and disorder in ordered systems: Random matrix theory for isotropic and nematic liquid crystals and its perspective on pseudo-nematic domains

    Science.gov (United States)

    Zhao, Yan; Stratt, Richard M.

    2018-05-01

    Surprisingly long-ranged intermolecular correlations begin to appear in isotropic (orientationally disordered) phases of liquid crystal forming molecules when the temperature or density starts to close in on the boundary with the nematic (ordered) phase. Indeed, the presence of slowly relaxing, strongly orientationally correlated, sets of molecules under putatively disordered conditions ("pseudo-nematic domains") has been apparent for some time from light-scattering and optical-Kerr experiments. Still, a fully microscopic characterization of these domains has been lacking. We illustrate in this paper how pseudo-nematic domains can be studied in even relatively small computer simulations by looking for order-parameter tensor fluctuations much larger than one would expect from random matrix theory. To develop this idea, we show that random matrix theory offers an exact description of how the probability distribution for liquid-crystal order parameter tensors converges to its macroscopic-system limit. We then illustrate how domain properties can be inferred from finite-size-induced deviations from these random matrix predictions. A straightforward generalization of time-independent random matrix theory also allows us to prove that the analogous random matrix predictions for the time dependence of the order-parameter tensor are similarly exact in the macroscopic limit, and that relaxation behavior of the domains can be seen in the breakdown of the finite-size scaling required by that random-matrix theory.

  9. Does quasi-long-range order in the two-dimensional XY model really survive weak random phase fluctuations?

    International Nuclear Information System (INIS)

    Mudry, Christopher; Wen Xiaogang

    1999-01-01

    Effective theories for random critical points are usually non-unitary, and thus may contain relevant operators with negative scaling dimensions. To study the consequences of the existence of negative-dimensional operators, we consider the random-bond XY model. It has been argued that the XY model on a square lattice, when weakly perturbed by random phases, has a quasi-long-range ordered phase (the random spin wave phase) at sufficiently low temperatures. We show that infinitely many relevant perturbations to the proposed critical action for the random spin wave phase were omitted in all previous treatments. The physical origin of these perturbations is intimately related to the existence of broadly distributed correlation functions. We find that those relevant perturbations do enter the Renormalization Group equations, and affect critical behavior. This raises the possibility that the random XY model has no quasi-long-range ordered phase and no Kosterlitz-Thouless (KT) phase transition

  10. The sink strengths of voids and the expected swelling for both random and ordered void distributions

    International Nuclear Information System (INIS)

    Quigley, T.M.; Murphy, S.M.; Bullough, R.; Wood, M.H.

    1981-10-01

    The sink strength of a void has been obtained when the void is a member of a random or ordered distribution of voids. The former sink strength derivation has employed the embedding model and the latter the cellular model. In each case the spatially varying size-effect interaction between the intrinsic point defects and the voids has been included together with the presence of other sink types in addition to the voids. The results are compared with previously published sink strengths that have made use of an approximate representation for the size-effect interactions, and indicate the importance of using the exact form of the interaction. In particular the bias for interstitials compared with vacancies of small voids is now much reduced and contamination of the surfaces of such voids no longer appears essential to facilitate the nucleation and growth of the voids. These new sink strengths have been used, in conjunction with recently published dislocation sink strengths, to calculate the expected swelling of materials containing network dislocations and voids. Results are presented for both the random and the void lattice situations. (author)

  11. Randomness in preference orderings, outcomes and attribute tastes: An application to journey time risk

    DEFF Research Database (Denmark)

    Batley, Richard; Ibáñez Rivas, Juan Nicolás

    2012-01-01

    estimate a mean ‘reliability ratio’ (ratio of the value of standard deviation of journey time to the value of scheduled journey time) of 2.07, against a median of 0.85. The properties of the distribution of the reliability ratio suggest a predominant behaviour of aversion to journey time risk.......Within the broad area of probabilistic modelling of individual discrete choice, we develop three strands of discussion. First, we outline a theoretical framework for the modelling of individual discrete choice under risk, distinguishing between three specific sources of randomness; in preference...... orderings, in outcomes, and in attribute tastes. Second, we apply this theoretical modelling framework to the domain of journey time risk (or ‘reliability’), a subject which has acquired prominence in the transportation policies of many countries. Third, we apply the modelling framework empirically, based...

  12. Some Limit Properties of Random Transition Probability for Second-Order Nonhomogeneous Markov Chains Indexed by a Tree

    Directory of Open Access Journals (Sweden)

    Shi Zhiyan

    2009-01-01

    Full Text Available We study some limit properties of the harmonic mean of random transition probability for a second-order nonhomogeneous Markov chain and a nonhomogeneous Markov chain indexed by a tree. As corollary, we obtain the property of the harmonic mean of random transition probability for a nonhomogeneous Markov chain.

  13. REGULAR METHOD FOR SYNTHESIS OF BASIC BENT-SQUARES OF RANDOM ORDER

    Directory of Open Access Journals (Sweden)

    A. V. Sokolov

    2016-01-01

    Full Text Available The paper is devoted to the class construction of the most non-linear Boolean bent-functions of any length N = 2k (k = 2, 4, 6…, on the basis of their spectral representation – Agievich bent squares. These perfect algebraic constructions are used as a basis to build many new cryptographic primitives, such as generators of pseudo-random key sequences, crypto graphic S-boxes, etc. Bent-functions also find their application in the construction of C-codes in the systems with code division multiple access (CDMA to provide the lowest possible value of Peak-to-Average Power Ratio (PAPR k = 1, as well as for the construction of error-correcting codes and systems of orthogonal biphasic signals. All the numerous applications of bent-functions relate to the theory of their synthesis. However, regular methods for complete class synthesis of bent-functions of any length N = 2k are currently unknown. The paper proposes a regular synthesis method for the basic Agievich bent squares of any order n, based on a regular operator of dyadic shift. Classification for a complete set of spectral vectors of lengths (l = 8, 16, … based on a criterion of the maximum absolute value and set of absolute values of spectral components has been carried out in the paper. It has been shown that any spectral vector can be a basis for building bent squares. Results of the synthesis for the Agievich bent squares of order n = 8 have been generalized and it has been revealed that there are only 3 basic bent squares for this order, while the other 5 can be obtained with help the operation of step-cyclic shift. All the basic bent squares of order n = 16 have been synthesized that allows to construct the bent-functions of length N = 256. The obtained basic bent squares can be used either for direct synthesis of bent-functions and their practical application or for further research in order to synthesize new structures of bent squares of orders n = 16, 32, 64, …

  14. IRFK2D: a computer program for simulating intrinsic random functions of order k

    Science.gov (United States)

    Pardo-Igúzquiza, Eulogio; Dowd, Peter A.

    2003-07-01

    IRFK2D is an ANSI Fortran-77 program that generates realizations of an intrinsic function of order k (with k equal to 0, 1 or 2) with a permissible polynomial generalized covariance model. The realizations may be non-conditional or conditioned to the experimental data. The turning bands method is used to generate realizations in 2D and 3D from simulations of an intrinsic random function of order k along lines that span the 2D or 3D space. The program generates two output files, the first containing the simulated values and the second containing the theoretical generalized variogram for different directions together with the theoretical model. The experimental variogram is calculated from the simulated values while the theoretical variogram is the specified generalized covariance model. The generalized variogram is used to assess the quality of the simulation as measured by the extent to which the generalized covariance is reproduced by the simulation. The examples given in this paper indicate that IRFK2D is an efficient implementation of the methodology.

  15. First-order reversal curves of single domain particles: diluted random assemblages and chains

    Science.gov (United States)

    Egli, R.

    2009-04-01

    Exact magnetic models can be used to calculate first-order reversal curves (FORC) of single domain (SD) particle assemblages, as shown by Newell [2005] for the case of isolated Stoner-Wohlfarth particles. After overcoming experimental difficulties, a FORC diagram sharing many similarities to Newell's model has been measured on a lake sediment sample (see A.P. Chen et al., "Quantification of magnetofossils using first-order reversal curves", EGU General Assembly 2009, Abstracts Vol. 11, EGU2009-10719). This sample contains abundant magnetofossils, as shown by coercivity analysis and electron microscopy, therefore suggesting that well dispersed, intact magnetosome chains are the main SD carriers. Subtle differences between the reversible and the irreversible contributions of the measured FORC distribution suggest that magnetosome chains might not be correctly described by the Stoner-Wohlfarth model. To better understand the hysteresis properties of such chains, a simple magnetic model has been implemented, taking dipole-dipole interactions between particles within the same chain into account. The model results depend on the magnetosome elongation, the number of magnetosomes in a chain, and the gap between them. If the chain axis is subparallel to the applied field, the magnetic moment reverses by a pseudo-fanning mode, which is replaced by a pseudo-coherent rotation mode at greater angles. These reversal modes are intrinsically different from coherent rotation assumed Stoner-Wohlfarth model, resulting in FORC diagrams with a smaller reversible component. On the other hand, isolated authigenic SD particles can precipitate in the sediment matrix, as it might occur for pedogenic magnetite. In this case, an assembly of randomly located particles provides a possible model for the resulting FORC diagram. If the concentration of the particles is small, each particle is affected by a random interaction field whose statistical distribution can be calculated from first

  16. Anisotropy of the monomer random walk in a polymer melt: local-order and connectivity effects

    International Nuclear Information System (INIS)

    Bernini, S; Leporini, D

    2016-01-01

    The random walk of a bonded monomer in a polymer melt is anisotropic due to local order and bond connectivity. We investigate both effects by molecular-dynamics simulations on melts of fully-flexible linear chains ranging from dimers (M  =  2) up to entangled polymers (M  =  200). The corresponding atomic liquid is also considered a reference system. To disentangle the influence of the local geometry and the bond arrangements, and to reveal their interplay, we define suitable measures of the anisotropy emphasising either the former or the latter aspect. Connectivity anisotropy, as measured by the correlation between the initial bond orientation and the direction of the subsequent monomer displacement, shows a slight enhancement due to the local order at times shorter than the structural relaxation time. At intermediate times—when the monomer displacement is comparable to the bond length—a pronounced peak and then decays slowly as t −1/2 , becoming negligible when the displacement is as large as about five bond lengths, i.e. about four monomer diameters or three Kuhn lengths. Local-geometry anisotropy, as measured by the correlation between the initial orientation of a characteristic axis of the Voronoi cell and the subsequent monomer dynamics, is affected at shorter times than the structural relaxation time by the cage shape with antagonistic disturbance by the connectivity. Differently, at longer times, the connectivity favours the persistence of the local-geometry anisotropy, which vanishes when the monomer displacement exceeds the bond length. Our results strongly suggest that the sole consideration of the local order is not enough to understand the microscopic origin of the rattling amplitude of the trapped monomer in the cage of the neighbours. (paper)

  17. Application of random coherence order selection in gradient-enhanced multidimensional NMR

    International Nuclear Information System (INIS)

    Bostock, Mark J.; Nietlispach, Daniel

    2016-01-01

    Development of multidimensional NMR is essential to many applications, for example in high resolution structural studies of biomolecules. Multidimensional techniques enable separation of NMR signals over several dimensions, improving signal resolution, whilst also allowing identification of new connectivities. However, these advantages come at a significant cost. The Fourier transform theorem requires acquisition of a grid of regularly spaced points to satisfy the Nyquist criterion, while frequency discrimination and acquisition of a pure phase spectrum require acquisition of both quadrature components for each time point in every indirect (non-acquisition) dimension, adding a factor of 2 N -1 to the number of free- induction decays which must be acquired, where N is the number of dimensions. Compressed sensing (CS) ℓ 1 -norm minimisation in combination with non-uniform sampling (NUS) has been shown to be extremely successful in overcoming the Nyquist criterion. Previously, maximum entropy reconstruction has also been used to overcome the limitation of frequency discrimination, processing data acquired with only one quadrature component at a given time interval, known as random phase detection (RPD), allowing a factor of two reduction in the number of points for each indirect dimension (Maciejewski et al. 2011 PNAS 108 16640). However, whilst this approach can be easily applied in situations where the quadrature components are acquired as amplitude modulated data, the same principle is not easily extended to phase modulated (P-/N-type) experiments where data is acquired in the form exp (iωt) or exp (-iωt), and which make up many of the multidimensional experiments used in modern NMR. Here we demonstrate a modification of the CS ℓ 1 -norm approach to allow random coherence order selection (RCS) for phase modulated experiments; we generalise the nomenclature for RCS and RPD as random quadrature detection (RQD). With this method, the power of RQD can be extended

  18. Loss of long-range magnetic order in a nanoparticle assembly due to random anisotropy

    International Nuclear Information System (INIS)

    Binns, C; Howes, P B; Baker, S H; Marchetto, H; Potenza, A; Steadman, P; Dhesi, S S; Roy, M; Everard, M J; Rushforth, A

    2008-01-01

    We have used soft x-ray photoemission electron microscopy (XPEEM) combined with x-ray magnetic circular dichroism (XMCD) and DC SQUID (superconducting quantum interference device) magnetometry to probe the magnetic ground state in Fe thin films produced by depositing size-selected gas-phase Fe nanoparticles with a diameter of 1.7 nm (∼200 atoms) onto Si substrates. The depositions were carried out in ultrahigh vacuum conditions and thicknesses of the deposited film in the range 5-50 nm were studied. The magnetometry data are consistent with the film forming a correlated super-spin glass with a magnetic correlation length ∼5 nm. The XPEEM magnetic maps from the cluster-assembled films were compared to those for a conventional thin Fe film with a thickness of 20 nm produced by a molecular beam epitaxy (MBE) source. Whereas a normal magnetic domain structure is observed in the conventional MBE thin film, no domain structure could be observed in any of the nanoparticle films down to the resolution limit of the XMCD based XPEEM (100 nm) confirming the ground state indicated by the magnetometry measurements. This observation is consistent with the theoretical prediction that an arbitrarily weak random anisotropy field will destroy long-range magnetic order

  19. An Authenticated Key Agreement Scheme Based on Cyclic Automorphism Subgroups of Random Orders

    Directory of Open Access Journals (Sweden)

    Yang Jun

    2017-01-01

    Full Text Available Group-based cryptography is viewed as a modern cryptographic candidate solution to blocking quantum computer attacks, and key exchange protocols on the Internet are one of the primitives to ensure the security of communication. In 2016 Habeeb et al proposed a “textbook” key exchange protocol based on the semidirect product of two groups, which is insecure for use in real-world applications. In this paper, after discarding the unnecessary disguising notion of semidirect product in the protocol, we establish a simplified yet enhanced authenticated key agreement scheme based on cyclic automorphism subgroups of random orders by making hybrid use of certificates and symmetric-key encryption as challenge-and-responses in the public-key setting. Its passive security is formally analyzed, which is relative to the cryptographic hardness assumption of a computational number-theoretic problem. Cryptanalysis of this scheme shows that it is secure against the intruder-in-the-middle attack even in the worst case of compromising the signatures, and provides explicit key confirmation to both parties.

  20. Exposure to virtual social interactions in the treatment of social anxiety disorder: A randomized controlled trial.

    Science.gov (United States)

    Kampmann, Isabel L; Emmelkamp, Paul M G; Hartanto, Dwi; Brinkman, Willem-Paul; Zijlstra, Bonne J H; Morina, Nexhmedin

    2016-02-01

    This randomized controlled trial investigated the efficacy of a stand-alone virtual reality exposure intervention comprising verbal interaction with virtual humans to target heterogeneous social fears in participants with social anxiety disorder. Sixty participants (Mage = 36.9 years; 63.3% women) diagnosed with social anxiety disorder were randomly assigned to individual virtual reality exposure therapy (VRET), individual in vivo exposure therapy (iVET), or waiting-list. Multilevel regression analyses revealed that both treatment groups improved from pre-to postassessment on social anxiety symptoms, speech duration, perceived stress, and avoidant personality disorder related beliefs when compared to the waiting-list. Participants receiving iVET, but not VRET, improved on fear of negative evaluation, speech performance, general anxiety, depression, and quality of life relative to those on waiting-list. The iVET condition was further superior to the VRET condition regarding decreases in social anxiety symptoms at post- and follow-up assessments, and avoidant personality disorder related beliefs at follow-up. At follow-up, all improvements were significant for iVET. For VRET, only the effect for perceived stress was significant. VRET containing extensive verbal interaction without any cognitive components can effectively reduce complaints of generalized social anxiety disorder. Future technological and psychological improvements of virtual social interactions might further enhance the efficacy of VRET for social anxiety disorder. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Internet-Delivered Exposure Therapy for Fibromyalgia: A Randomized Controlled Trial.

    Science.gov (United States)

    Hedman-Lagerlöf, Maria; Hedman-Lagerlöf, Erik; Axelsson, Erland; Ljótsson, Brjánn; Engelbrektsson, Johanna; Hultkrantz, Sofia; Lundbäck, Karolina; Björkander, Daniel; Wicksell, Rikard K; Flink, Ida; Andersson, Erik

    2018-06-01

    Fibromyalgia (FM) is a common and disabling chronic pain disorder, for which existing pharmacological and psychological treatments have yet yielded insufficient effects. Previous literature has shown that exposure therapy may be an effective treatment for chronic pain. This study constitutes the first randomized controlled trial evaluating exposure therapy for FM. A total of 140 participants with diagnosed FM were randomized to a 10-week Internet-delivered exposure treatment (iExp; n=70) or a waitlist control condition (WLC; n=70). Primary outcome measure were FM symptoms and impact, and secondary outcome measures were fatigue, disability, quality of life, pain-related distress and avoidance behaviors, insomnia, depression, and anxiety. Data retention was high (100% data completion at posttreatment for primary outcome, 96% at 6-month follow-up and 94% at 12-month follow-up). Results showed that participants in the iExp group made large and superior improvements compared with WLC on FM symptoms and impact (B, -1.93; z, -10.14; P<0.001, between-group Cohen d=0.90), as well as all secondary outcomes (between-group Cohen d ranging from 0.44 to 1.38) with sustained results. We conclude that iExp seems to be an efficacious treatment for FM compared with no treatment, and the results also highlight the potential increase of accessibility by using the Internet format to deliver psychological treatments for these patients. Future trials with active control conditions are warranted.

  2. Exposure to bisphenol A from drinking canned beverages increases blood pressure: randomized crossover trial.

    Science.gov (United States)

    Bae, Sanghyuk; Hong, Yun-Chul

    2015-02-01

    Bisphenol A (BPA) is a chemical used in plastic bottles and inner coating of beverage cans, and its exposure is almost ubiquitous. BPA has been associated with hypertension and decreased heart rate variability in the previous studies. The aim of the present study was to determine whether increased BPA exposure from consumption of canned beverage actually affects blood pressure and heart rate variability. We conducted a randomized crossover trial with noninstitutionalized adults, who were aged ≥60 years and recruited from a local community center. A total of 60 participants visited the study site 3 times, and they were provided the same beverage in 2 glass bottles, 2 cans, or 1 can and 1 glass bottle at a time. The sequence of the beverage was randomized. We then measured urinary BPA concentration, blood pressure, and heart rate variability 2 hours after the consumption of each beverage. The paired t test and mixed model were used to compare the differences. The urinary BPA concentration increased after consuming canned beverages by >1600% compared with that after consuming glass bottled beverages. Systolic blood pressure adjusted for daily variance increased by ≈4.5 mm Hg after consuming 2 canned beverages compared with that after consuming 2 glass bottled beverages, and the difference was statistically significant. The parameters of the heart rate variability did not show statistically significant differences.The present study demonstrated that consuming canned beverage and consequent increase of BPA exposure increase blood pressure acutely. © 2014 American Heart Association, Inc.

  3. Predictors of Suicide Ideation in a Random Digit Dial Study: Exposure to Suicide Matters.

    Science.gov (United States)

    van de Venne, Judy; Cerel, Julie; Moore, Melinda; Maple, Myfanwy

    2017-07-03

    Suicide is an important public health concern requiring ongoing research to understand risk factors for suicide ideation. A dual-frame, random digit dial survey was utilized to identify demographic and suicide-related factors associated with suicide ideation in a statewide sample of 1,736 adults. The PH-Q 9 Depression scale suicide ideation question was used to assess current suicide ideation in both the full sample and suicide exposed sub-sample. Being non-married and having previous suicide exposure were separately associated with higher risks of suicide ideation in the full sample. Being male, having increased suicide exposures, and having increased perceptions of closeness to the decedent increased risks, while older age decreased risks for the suicide exposed. Implications for future screening and research are discussed.

  4. Secondhand Smoke Exposure Reduction Intervention in Chinese Households of Young Children: A Randomized Controlled Trial.

    Science.gov (United States)

    Abdullah, Abu S; Hua, Fu; Khan, Hafiz; Xia, Xiao; Bing, Qi; Tarang, Kheradia; Winickoff, Jonathan P

    2015-01-01

    To assess whether a theory-based, community health worker-delivered intervention for household smokers will lead to reduced secondhand smoke exposure to children in Chinese families. Smoking parents or caregivers who had a child aged 5 years or younger at home were randomized to the intervention group (n = 164) to receive smoking hygiene intervention or to the comparison group (n = 154). The intervention was delivered by trained community health workers. Outcomes were assessed at 2- and 6- month follow-up. Of the 318 families randomized, 98 (60%) of 164 intervention group and 82 (53%) of 154 of controls completed 6-month follow-up assessment. At the 6-month follow-up, 62% of intervention and 45% of comparison group households adopted complete smoking restrictions at home (P = .022); total exposure (mean number of cigarettes per week ± standard deviation) from all smokers at home in the past 7 days was significantly lower among children in the intervention (3.29 ± 9.06) than the comparison (7.41 ± 14.63) group (P = .021); and mean urine cotinine level (ng/mL) was significantly lower in the intervention (0.030 ± .065) than the comparison (0.087 ± .027) group, P exposure to secondhand smoke. These findings have implications for the development of primary health care-based secondhand smoke exposure reduction and family oriented smoking cessation interventions as China moves toward a smoke-free society. Copyright © 2015 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  5. Sunlight exposure or vitamin D supplementation for vitamin D-deficient non-western immigrants: a randomized clinical trial

    NARCIS (Netherlands)

    Wicherts, I.S.; Boeke, A.J.P.; van der Meer, I.M.; van Schoor, N.M.; Knol, D.L.; Lips, P.T.A.M.

    2011-01-01

    Summary: Vitamin D deficiency is very common in non-western immigrants. In this randomized clinical trial, vitamin D 800 IU/day or 100,000 IU/3 months were compared with advised sunlight exposure. Vitamin D supplementation was more effective than advised sunlight exposure in improving vitamin D

  6. 29 CFR 570.57 - Exposure to radioactive substances and to ionizing radiations (Order 6).

    Science.gov (United States)

    2010-07-01

    ... to Their Health or Well-Being § 570.57 Exposure to radioactive substances and to ionizing radiations... radioactive substances and to ionizing radiations are particularly hazardous and detrimental to health for... involves exposure to ionizing radiations in excess of 0.5 rem per year. (b) Definitions. As used in this...

  7. Randomized and quantum algorithms for solving initial-value problems in ordinary differential equations of order k

    Directory of Open Access Journals (Sweden)

    Maciej Goćwin

    2008-01-01

    Full Text Available The complexity of initial-value problems is well studied for systems of equations of first order. In this paper, we study the \\(\\varepsilon\\-complexity for initial-value problems for scalar equations of higher order. We consider two models of computation, the randomized model and the quantum model. We construct almost optimal algorithms adjusted to scalar equations of higher order, without passing to systems of first order equations. The analysis of these algorithms allows us to establish upper complexity bounds. We also show (almost matching lower complexity bounds. The \\(\\varepsilon\\-complexity in the randomized and quantum setting depends on the regularity of the right-hand side function, but is independent of the order of equation. Comparing the obtained bounds with results known in the deterministic case, we see that randomized algorithms give us a speed-up by \\(1/2\\, and quantum algorithms by \\(1\\ in the exponent. Hence, the speed-up does not depend on the order of equation, and is the same as for the systems of equations of first order. We also include results of some numerical experiments which confirm theoretical results.

  8. The effectiveness of Narrative Exposure Therapy with traumatised firefighters in Saudi Arabia: a randomized controlled study.

    Science.gov (United States)

    Alghamdi, Mohammed; Hunt, Nigel; Thomas, Shirley

    2015-03-01

    Firefighters are exposed to many traumatic events. The psychological costs of this exposure increase the risk of Post-Traumatic Stress disorder (PTSD), depression and anxiety. This study examined the effectiveness of Narrative Exposure Therapy (NET) as a short-term treatment for reducing PTSD symptoms among Saudi firefighters. A randomized waiting-list control study was conducted with 34 traumatized firefighters were randomly allocated to NET or Waiting-list Control (WLC). The NET group received four therapy sessions of 60-90 min over a three-week period; those in the WLC condition received the same sessions after a three-week waiting period. Participants in both groups were assessed at baseline, immediately post-intervention and at 3 and 6 month follow ups. NET led to significant reductions in PTSD symptoms, anxiety and depression compared with WLC. After the WLC group received treatment, it showed the same improvements as the NET group. This occurred immediately post-treatment in both groups, but was not sustained at 3 and 6 month follow ups. Coping strategies and social support led to significant changes only in follow up times. NET was effective in reducing PTSD symptoms in traumatised Saudi firefighters. This finding could be helpful in the management of PTSD among people who work as first responders such as firefighters, police officers and emergency medical personal, as well as security officers. Copyright © 2015. Published by Elsevier Ltd.

  9. Higher order moments of a sum of random variables: remarks and applications.

    Directory of Open Access Journals (Sweden)

    Luisa Tibiletti

    1996-02-01

    Full Text Available The moments of a sum of random variables depend on both the pure moments of each random addendum and on the addendum mixed moments. In this note we introduce a simple measure to evaluate the relative impedance to attach to the latter. Once the pure moments are fixed, the functional relation between the random addenda leading to the extreme values is also provided. Applications to Finance, Decision Theory and Actuarial Sciences are also suggested.

  10. Order acceptance in food processing systems with random raw material requirements

    NARCIS (Netherlands)

    Kilic, Onur A.; van Donk, Dirk Pieter; Wijngaard, Jacob; Tarim, S. Armagan

    This study considers a food production system that processes a single perishable raw material into several products having stochastic demands. In order to process an order, the amount of raw material delivery from storage needs to meet the raw material requirement of the order. However, the amount

  11. A Naturalistic, Randomized Pilot Trial of E-Cigarettes: Uptake, Exposure, and Behavioral Effects.

    Science.gov (United States)

    Carpenter, Matthew J; Heckman, Bryan W; Wahlquist, Amy E; Wagener, Theodore L; Goniewicz, Maciej L; Gray, Kevin M; Froeliger, Brett; Cummings, K Michael

    2017-12-01

    Background: Most studies of electronic nicotine delivery systems (ENDS) compare self-selected users versus nonusers. The few randomized studies to date generally support a positive impact on reducing smoking behavior, but these studies are focused on guided ENDS use. This study presents a randomized, naturalistic trial of ENDS with prospective outcomes of uptake and behavioral changes in smoking. Methods: Adult smokers with minimal ENDS history were randomized in a 2:1 ratio to receive product for 3 weeks ( n = 46), or not ( n = 22). Changes in nicotine delivery (16 vs. 24 mg), midway through the study allowed a compelling opportunity to examine two ENDS products compared with the control group. Primary outcomes, assessed via daily diaries during sampling period and in-person laboratory visits over 4 months, included uptake and usage of ENDS, cessation-related outcomes, and exposure to smoke constituents. Results: All ENDS participants tried product at least once, with 48% of 24 mg and 30% of 16 mg using their assigned product for the entire sampling period. Within the 24 mg ENDs group, 57% made an independent purchase of ENDS, versus 28% of 16 mg, and 14% of control participants ( P = 0.01). Smokers in both ENDS groups significantly reduced their smoking, whereas control participants did not ( P = 0.03). Cessation behaviors (quit attempts, biologically verified abstinence) numerically but not statistically favored ENDS participants. Conclusions: Results suggest that cigarette smokers are willing to use ENDS with trends toward reduced cigarette smoking and positive changes in cessation-related behaviors. Impact: Randomized, naturalistic trials such as presented herein are needed to understand the population impact of e-cigarettes. Cancer Epidemiol Biomarkers Prev; 26(12); 1795-803. ©2017 AACR . ©2017 American Association for Cancer Research.

  12. Single order soft X-ray diffraction with quasi-random radius pinhole array spectroscopic photon sieves

    International Nuclear Information System (INIS)

    Zhang Qiang-Qiang; Wei Lai; Yang Zu-Hua; Qian Feng; Fan Quan-Ping; Zhang Bo; Gu Yu-Qiu; Cao Lei-Feng

    2014-01-01

    A novel single order diffraction grating in the soft X-ray region, called quasi-random radius pinhole array spectroscopic photon sieves (QRSPS), is proposed in this paper. This new grating is composed of pinholes on a substrate, whose radii are quasi-random, while their centers are regular. Analysis proves that its transmittance function across the grating bar is similar to that of sinusoidal transmission gratings. Simulation results show that the QRSPS can suppress higher-order diffraction effectively. And the QRSPS would still retain its characteristic of single order diffraction when we take the effect of X-ray penetration into account. These properties indicate that the QRSPS can be used in the soft X-ray spectra measurement. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  13. In-car nocturnal blue light exposure improves motorway driving: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Jacques Taillard

    Full Text Available Prolonged wakefulness greatly decreases nocturnal driving performance. The development of in-car countermeasures is a future challenge to prevent sleep-related accidents. The aim of this study is to determine whether continuous exposure to monochromatic light in the short wavelengths (blue light, placed on the dashboard, improves night-time driving performance. In this randomized, double-blind, placebo-controlled, cross-over study, 48 healthy male participants (aged 20-50 years drove 400 km (250 miles on motorway during night-time. They randomly and consecutively received either continuous blue light exposure (GOLite, Philips, 468 nm during driving or 2*200 mg of caffeine or placebo of caffeine before and during the break. Treatments were separated by at least 1 week. The outcomes were number of inappropriate line crossings (ILC and mean standard deviation of the lateral position (SDLP. Eight participants (17% complained about dazzle during blue light exposure and were removed from the analysis. Results from the 40 remaining participants (mean age ± SD: 32.9±11.1 showed that countermeasures reduced the number of inappropriate line crossings (ILC (F(2,91.11 = 6.64; p<0.05. Indeed, ILC were lower with coffee (12.51 [95% CI, 5.86 to 19.66], p = 0.001 and blue light (14.58 [CI, 8.75 to 22.58], p = 0.003 than with placebo (26.42 [CI, 19.90 to 33.71]. Similar results were found for SDLP. Treatments did not modify the quality, quantity and timing of 3 subsequent nocturnal sleep episodes. Despite a lesser tolerance, a non-inferior efficacy of continuous nocturnal blue light exposure compared with caffeine suggests that this in-car countermeasure, used occasionally, could be used to fight nocturnal sleepiness at the wheel in blue light-tolerant drivers, whatever their age. More studies are needed to determine the reproducibility of data and to verify if it can be generalized to women.ClinicalTrials.gov NCT01070004.

  14. Competing order parameters in quenched random alloys: Fe/sub 1-x/Co/sub x/Cl2

    International Nuclear Information System (INIS)

    Wong, P.; Horn, P.M.; Birgeneau, R.J.; Safinya, C.R.; Shirane, G.

    1980-01-01

    A study is reported of the magnetic properties of the random alloy Fe/sub 1-x/Co/sub x/Cl 2 , which represents an archetypal example of a system with competing orthogonal spin anisotropies. Behavior similar to previous experiments and theoretical predictions is found, but with important qualitative and quantitative differences; in particular the phase transition in one variable is drastically altered by the existence of long-range order in the other variable. It is hypothesized that this is due to microscopic random-field effects

  15. TEM study of long range ordering in a Ni-25Mo-8Cr alloy subjected to 4000 hour exposure

    International Nuclear Information System (INIS)

    Dymek, S.; Wrobel, M.; Blicharski, M.; Gazdowicz, J.

    1999-01-01

    The Ni-25Mo-8Cr (wt.%) alloy exhibits high-temperature strength and ductility, low thermal expansion characteristics, good oxidation resistance and excellent fabricability. The effect of prolong exposure to the working temperatures (650 o C-700 o C) on the stability of microstructure and deformation behaviour at this temperatures have not been fully understand yet. This research has been undertaken to fill this gap. The objective of this paper is to discuss the effects of 4000 hours exposure to temperature 650 o C on the stability of the ordered phase and its influence on the mechanical properties

  16. Complexities of sibling analysis when exposures and outcomes change with time and birth order

    NARCIS (Netherlands)

    Sudan, Madhuri; Kheifets, Leeka I.; Arah, Onyebuchi A.; Divan, Hozefa A.; Olsen, Jørn

    2014-01-01

    In this study, we demonstrate the complexities of performing a sibling analysis with a re-examination of associations between cell phone exposures and behavioral problems observed previously in the Danish National Birth Cohort. Children (52,680; including 5441 siblings) followed up to age 7 were

  17. Randomized Exposure to Food Advertisements and Eating in the Absence of Hunger Among Preschoolers.

    Science.gov (United States)

    Emond, Jennifer A; Lansigan, Reina K; Ramanujam, Archana; Gilbert-Diamond, Diane

    2016-12-01

    Preschoolers in the United States are heavily exposed to unhealthy food advertisements. Whether such exposure promotes cued eating has not been documented in this age group. Randomized experiment among 60 children, aged 2 to 5 years, recruited in 2015-2016 from New Hampshire and Vermont. Children completed the experiment at a behavioral laboratory. Children were provided with a healthy snack to consume upon arrival then randomized to view a 14-minute TV program embedded with advertisements for either a food or a department store. Children were provided 2 snack foods to consume ad libitum while viewing the TV program; 1 of those snacks was the food advertised. Eating in the absence of hunger (EAH) was operationalized as the kilocalories of snack foods consumed. t tests were used to compare EAH by advertisement condition; linear regression models assessed effect modification by the child's age, sex, BMI percentile, and parental feeding restriction. Mean age was 4.1 (SD 0.9) years, 55% of children were male, 80% were non-Hispanic white, and 20% were overweight or obese. There were no differences in child or socioeconomic characteristics by advertisement condition. Child BMI was not related to EAH. Mean kilocalories consumed during the EAH phase was greater among children exposed to the food advertisements (126.8, SD: 58.5) versus those exposed to the nonfood advertisements (97.3, SD: 52.3; P = .04), an effect driven by greater consumption of the advertised food (P < .01). There was no evidence of effect modification. Findings suggest that food advertisement exposure may encourage obesogenic-eating behaviors among the very young. Copyright © 2016 by the American Academy of Pediatrics.

  18. Effects of cue-exposure treatment on neural cue reactivity in alcohol dependence: a randomized trial.

    Science.gov (United States)

    Vollstädt-Klein, Sabine; Loeber, Sabine; Kirsch, Martina; Bach, Patrick; Richter, Anne; Bühler, Mira; von der Goltz, Christoph; Hermann, Derik; Mann, Karl; Kiefer, Falk

    2011-06-01

    In alcohol-dependent patients, alcohol-associated cues elicit brain activation in mesocorticolimbic networks involved in relapse mechanisms. Cue-exposure based extinction training (CET) has been shown to be efficacious in the treatment of alcoholism; however, it has remained unexplored whether CET mediates its therapeutic effects via changes of activity in mesolimbic networks in response to alcohol cues. In this study, we assessed CET treatment effects on cue-induced responses using functional magnetic resonance imaging (fMRI). In a randomized controlled trial, abstinent alcohol-dependent patients were randomly assigned to a CET group (n = 15) or a control group (n = 15). All patients underwent an extended detoxification treatment comprising medically supervised detoxification, health education, and supportive therapy. The CET patients additionally received nine CET sessions over 3 weeks, exposing the patient to his/her preferred alcoholic beverage. Cue-induced fMRI activation to alcohol cues was measured at pretreatment and posttreatment. Compared with pretreatment, fMRI cue-reactivity reduction was greater in the CET relative to the control group, especially in the anterior cingulate gyrus and the insula, as well as limbic and frontal regions. Before treatment, increased cue-induced fMRI activation was found in limbic and reward-related brain regions and in visual areas. After treatment, the CET group showed less activation than the control group in the left ventral striatum. The study provides first evidence that an exposure-based psychotherapeutic intervention in the treatment of alcoholism impacts on brain areas relevant for addiction memory and attentional focus to alcohol-associated cues and affects mesocorticolimbic reward pathways suggested to be pathophysiologically involved in addiction. Copyright © 2011 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  19. Efficacy of virtual reality exposure therapy for treatment of dental phobia: a randomized control trial.

    Science.gov (United States)

    Raghav, Kumar; Van Wijk, A J; Abdullah, Fawzia; Islam, Md Nurul; Bernatchez, Marc; De Jongh, Ad

    2016-02-27

    Virtual Reality Exposure Therapy (VRET) is found to be a promising and a viable alternative for in vivo exposure in the treatment of specific phobias. However, its usefulness for treating dental phobia is unexplored. The aims of the present study are to determine: (a) the efficacy of VRET versus informational pamphlet (IP) control group in terms of dental trait and state anxiety reductions at 1 week, 3 months and 6 months follow-up (b) the real-time physiological arousal [heart rate (HR)] of VRET group participants during and following therapy (c) the relation between subjective (presence) and objective (HR) measures during VRET. This study is a single blind, randomized controlled trial with two parallel arms in which participants will be allocated to VRET or IP with a ratio of 1:1. Thirty participants (18-50 years) meeting the Phobia Checklist criteria of dental phobia will undergo block randomization with allocation concealment. The primary outcome measures include participants' dental trait anxiety (Modified Dental Anxiety Scale and Dental Fear Survey) and state anxiety (Visual Analogue Scale) measured at baseline (T0), at intervention (T1), 1-week (T2), 3 months (T3) and 6 months (T4) follow-up. A behavior test will be conducted before and after the intervention. The secondary outcome measures are real-time evaluation of HR and VR (Virtual Reality) experience (presence, realism, nausea) during and following the VRET intervention respectively. The data will be analyzed using intention-to-treat and per-protocol analysis. This study uses novel non-invasive VRET, which may provide a possible alternative treatment for dental anxiety and phobia. ISRCTN25824611 , Date of registration: 26 October 2015.

  20. Cue exposure therapy for the treatment of opiate addiction: results of a randomized controlled clinical trial.

    Science.gov (United States)

    Marissen, Marlies A E; Franken, Ingmar H A; Blanken, Peter; van den Brink, Wim; Hendriks, Vincent M

    2007-01-01

    Persistent cue reactivity to drug-related stimuli is a well-known phenomenon among abstinent drug users and has been found to be a predictor of relapse. Cue exposure therapy (CET) aims to reduce this cue reactivity by exposing abstinent drug users to conditioned drug-related stimuli while preventing their habitual response, i.e. drug use. 127 abstinent heroin-dependent Dutch inpatients were randomized to CET (n = 65; 55 completers) and placebo psychotherapy treatment (PPT) (n = 62; 59 completers). It was examined whether CET would lead to a decrease in drug-related cue reactivity (using mixed-design ANOVA) and subsequently to lower dropout and relapse rates (using logistic regression) compared to PPT. Both groups responded with a similar decrease in self-reported cue reactivity (craving, mood). The CET group did show a significant decrease in physiological reactivity (skin conductance) compared to PPT. However, dropout and relapse rates were, contrary to our expectations, significantly higher in the CET group. This is the first randomized controlled trial showing that CET, compared to a non-specific psychotherapy, might increase dropout and relapse rates among abstinent heroin-dependent clients in a drug-free setting. Caution is warranted when applying CET in this specific context. Copyright 2007 S. Karger AG, Basel.

  1. Efficacy of succimer chelation of mercury at background exposures in toddlers: a randomized trial

    Science.gov (United States)

    Cao, Yang; Chen, Aimin; Jones, Robert L.; Radcliffe, Jerilynn; Dietrich, Kim N.; Caldwell, Kathleen L.; Peddada, Shyamal; Rogan, Walter J.

    2011-01-01

    Objective To examine whether succimer, a mercaptan compound known to reduce blood lead concentration in children, reduces blood mercury concentration. Study Design We used samples from a randomized clinical trial of succimer chelation for lead-exposed children. We measured mercury in pre-treatment samples from 767 children. We also measured mercury in blood samples drawn 1 week after treatment began (N=768) and in a 20% random sample of the children who received the maximum 3 courses of treatment (N=67). A bootstrap-based isotonic regression method was used to compare the trend over time in the difference between the adjusted mean mercury concentrations in the succimer group and the placebo group. Results The adjusted mean organic mercury concentration in the succimer group relative to the placebo group fell from 99% at baseline to 82% after three courses of treatment (p for trend = 0.048), but this resulted from the prevention of the age-related increase in the succimer group. Conclusion Succimer chelation for low level organic mercury exposure in children has limited efficacy. PMID:20889164

  2. Exposure to a multi-level multi-component childhood obesity prevention community-randomized controlled trial: patterns, determinants, and implications.

    Science.gov (United States)

    Trude, Angela Cristina Bizzotto; Kharmats, Anna Yevgenyevna; Jones-Smith, Jessica C; Gittelsohn, Joel

    2018-05-22

    For community interventions to be effective in real-world conditions, participants need to have sufficient exposure to the intervention. It is unclear how the dose and intensity of the intervention differ among study participants in low-income areas. We aimed to understand patterns of exposure to different components of a multi-level multi-component obesity prevention program to inform our future impact analyses. B'more Healthy Communities for Kids (BHCK) was a community-randomized controlled trial implemented in 28 low-income zones in Baltimore in two rounds (waves). Exposure to three different intervention components (corner store/carryout restaurants, social media/text messaging, and youth-led nutrition education) was assessed via post-intervention interviews with 385 low-income urban youths and their caregivers. Exposure scores were generated based on self-reported viewing of BHCK materials (posters, handouts, educational displays, and social media posts) and participating in activities, including taste tests during the intervention. For each intervention component, points were assigned for exposure to study materials and activities, then scaled (0-1 range), yielding an overall BHCK exposure score [youths: mean 1.1 (range 0-7.6 points); caregivers: 1.1 (0-6.7), possible highest score: 13]. Ordered logit regression analyses were used to investigate correlates of youths' and caregivers' exposure level (quartile of exposure). Mean intervention exposure scores were significantly higher for intervention than comparison youths (mean 1.6 vs 0.5, p selection bias may exist affecting causal inference. ClinicalTrials.gov, NCT02181010 . Retrospectively registered on 2 July 2014.

  3. An MGF-based unified framework to determine the joint statistics of partial sums of ordered random variables

    KAUST Repository

    Nam, Sungsik

    2010-11-01

    Order statistics find applications in various areas of communications and signal processing. In this paper, we introduce an unified analytical framework to determine the joint statistics of partial sums of ordered random variables (RVs). With the proposed approach, we can systematically derive the joint statistics of any partial sums of ordered statistics, in terms of the moment generating function (MGF) and the probability density function (PDF). Our MGF-based approach applies not only when all the K ordered RVs are involved but also when only the Ks(Ks < K) best RVs are considered. In addition, we present the closed-form expressions for the exponential RV special case. These results apply to the performance analysis of various wireless communication systems over fading channels. © 2006 IEEE.

  4. Application of a stratified random sampling technique to the estimation and minimization of respirable quartz exposure to underground miners

    International Nuclear Information System (INIS)

    Makepeace, C.E.; Horvath, F.J.; Stocker, H.

    1981-11-01

    The aim of a stratified random sampling plan is to provide the best estimate (in the absence of full-shift personal gravimetric sampling) of personal exposure to respirable quartz among underground miners. One also gains information of the exposure distribution of all the miners at the same time. Three variables (or strata) are considered in the present scheme: locations, occupations and times of sampling. Random sampling within each stratum ensures that each location, occupation and time of sampling has equal opportunity of being selected without bias. Following implementation of the plan and analysis of collected data, one can determine the individual exposures and the mean. This information can then be used to identify those groups whose exposure contributes significantly to the collective exposure. In turn, this identification, along with other considerations, allows the mine operator to carry out a cost-benefit optimization and eventual implementation of engineering controls for these groups. This optimization and engineering control procedure, together with the random sampling plan, can then be used in an iterative manner to minimize the mean value of the distribution and collective exposures

  5. Random balance designs for the estimation of first order global sensitivity indices

    International Nuclear Information System (INIS)

    Tarantola, S.; Gatelli, D.; Mara, T.A.

    2006-01-01

    We present two methods for the estimation of main effects in global sensitivity analysis. The methods adopt Satterthwaite's application of random balance designs in regression problems, and extend it to sensitivity analysis of model output for non-linear, non-additive models. Finite as well as infinite ranges for model input factors are allowed. The methods are easier to implement than any other method available for global sensitivity analysis, and reduce significantly the computational cost of the analysis. We test their performance on different test cases, including an international benchmark on safety assessment for nuclear waste disposal originally carried out by OECD/NEA

  6. Random balance designs for the estimation of first order global sensitivity indices

    Energy Technology Data Exchange (ETDEWEB)

    Tarantola, S. [Joint Research Centre, European Commission, Institute of the Protection and Security of the Citizen, TP 361, Via E. Fermi 1, 21020 Ispra (Vatican City State, Holy See,) (Italy)]. E-mail: stefano.tarantola@jrc.it; Gatelli, D. [Joint Research Centre, European Commission, Institute of the Protection and Security of the Citizen, TP 361, Via E. Fermi 1, 21020 Ispra (VA) (Italy); Mara, T.A. [Laboratory of Industrial engineering, University of Reunion Island, BP 7151, 15 avenue Rene Cassin, 97 715 Saint-Denis (France)

    2006-06-15

    We present two methods for the estimation of main effects in global sensitivity analysis. The methods adopt Satterthwaite's application of random balance designs in regression problems, and extend it to sensitivity analysis of model output for non-linear, non-additive models. Finite as well as infinite ranges for model input factors are allowed. The methods are easier to implement than any other method available for global sensitivity analysis, and reduce significantly the computational cost of the analysis. We test their performance on different test cases, including an international benchmark on safety assessment for nuclear waste disposal originally carried out by OECD/NEA.

  7. Exposure and non-fear emotions: A randomized controlled study of exposure-based and rescripting-based imagery in PTSD treatment.

    Science.gov (United States)

    Langkaas, Tomas Formo; Hoffart, Asle; Øktedalen, Tuva; Ulvenes, Pål G; Hembree, Elizabeth A; Smucker, Mervin

    2017-10-01

    Interventions involving rescripting-based imagery have been proposed as a better approach than exposure-based imagery when posttraumatic stress disorder (PTSD) is associated with emotions other than fear. Prior research led to the study's hypotheses that (a) higher pretreatment non-fear emotions would predict relatively better response to rescripting as compared to exposure, (b) rescripting would be associated with greater reduction in non-fear emotions, and (c) pretreatment non-fear emotions would predict poor response to exposure. A clinically representative sample of 65 patients presenting a wide range of traumas was recruited from patients seeking and being offered PTSD treatment in an inpatient setting. Subjects were randomly assigned to 10 weeks of treatment involving either rescripting-based imagery (Imagery Rescripting; IR) or exposure-based imagery (Prolonged Exposure; PE). Patients were assessed on outcome and emotion measures at pretreatment, posttreatment and 12 months follow-up. Comparison to control benchmarks indicated that both treatments were effective, but no outcome differences between them appeared. None of the initial hypotheses were supported. The results from this study challenge previous observations and hypotheses about exposure mainly being effective for fear-based PTSD and strengthen the notion that exposure-based treatment is a generally effective treatment for all types of PTSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Finding Order in Randomness: Single-Molecule Studies Reveal Stochastic RNA Processing | Center for Cancer Research

    Science.gov (United States)

    Producing a functional eukaryotic messenger RNA (mRNA) requires the coordinated activity of several large protein complexes to initiate transcription, elongate nascent transcripts, splice together exons, and cleave and polyadenylate the 3’ end. Kinetic competition between these various processes has been proposed to regulate mRNA maturation, but this model could lead to multiple, randomly determined, or stochastic, pathways or outcomes. Regulatory checkpoints have been suggested as a means of ensuring quality control. However, current methods have been unable to tease apart the contributions of these processes at a single gene or on a time scale that could provide mechanistic insight. To begin to investigate the kinetic relationship between transcription and splicing, Daniel Larson, Ph.D., of CCR’s Laboratory of Receptor Biology and Gene Expression, and his colleagues employed a single-molecule RNA imaging approach to monitor production and processing of a human β-globin reporter gene in living cells.

  9. In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Cristina Botella

    Full Text Available Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31 versus an Augmented Reality system (N = 32 in a randomized controlled trial. "One-session treatment" guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants' expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.

  10. In Vivo versus Augmented Reality Exposure in the Treatment of Small Animal Phobia: A Randomized Controlled Trial.

    Science.gov (United States)

    Botella, Cristina; Pérez-Ara, M Ángeles; Bretón-López, Juana; Quero, Soledad; García-Palacios, Azucena; Baños, Rosa María

    2016-01-01

    Although in vivo exposure is the treatment of choice for specific phobias, some acceptability problems have been associated with it. Virtual Reality exposure has been shown to be as effective as in vivo exposure, and it is widely accepted for the treatment of specific phobias, but only preliminary data are available in the literature about the efficacy of Augmented Reality. The purpose of the present study was to examine the efficacy and acceptance of two treatment conditions for specific phobias in which the exposure component was applied in different ways: In vivo exposure (N = 31) versus an Augmented Reality system (N = 32) in a randomized controlled trial. "One-session treatment" guidelines were followed. Participants in the Augmented Reality condition significantly improved on all the outcome measures at post-treatment and follow-ups. When the two treatment conditions were compared, some differences were found at post-treatment, favoring the participants who received in vivo exposure. However, these differences disappeared at the 3- and 6-month follow-ups. Regarding participants' expectations and satisfaction with the treatment, very positive ratings were reported in both conditions. In addition, participants from in vivo exposure condition considered the treatment more useful for their problem whereas participants from Augmented Reality exposure considered the treatment less aversive. Results obtained in this study indicate that Augmented Reality exposure is an effective treatment for specific phobias and well accepted by the participants.

  11. A unified model for transfer alignment at random misalignment angles based on second-order EKF

    International Nuclear Information System (INIS)

    Cui, Xiao; Qin, Yongyuan; Yan, Gongmin; Liu, Zhenbo; Mei, Chunbo

    2017-01-01

    In the transfer alignment process of inertial navigation systems (INSs), the conventional linear error model based on the small misalignment angle assumption cannot be applied to large misalignment situations. Furthermore, the nonlinear model based on the large misalignment angle suffers from redundant computation with nonlinear filters. This paper presents a unified model for transfer alignment suitable for arbitrary misalignment angles. The alignment problem is transformed into an estimation of the relative attitude between the master INS (MINS) and the slave INS (SINS), by decomposing the attitude matrix of the latter. Based on the Rodriguez parameters, a unified alignment model in the inertial frame with the linear state-space equation and a second order nonlinear measurement equation are established, without making any assumptions about the misalignment angles. Furthermore, we employ the Taylor series expansions on the second-order nonlinear measurement equation to implement the second-order extended Kalman filter (EKF2). Monte-Carlo simulations demonstrate that the initial alignment can be fulfilled within 10 s, with higher accuracy and much smaller computational cost compared with the traditional unscented Kalman filter (UKF) at large misalignment angles. (paper)

  12. A unified model for transfer alignment at random misalignment angles based on second-order EKF

    Science.gov (United States)

    Cui, Xiao; Mei, Chunbo; Qin, Yongyuan; Yan, Gongmin; Liu, Zhenbo

    2017-04-01

    In the transfer alignment process of inertial navigation systems (INSs), the conventional linear error model based on the small misalignment angle assumption cannot be applied to large misalignment situations. Furthermore, the nonlinear model based on the large misalignment angle suffers from redundant computation with nonlinear filters. This paper presents a unified model for transfer alignment suitable for arbitrary misalignment angles. The alignment problem is transformed into an estimation of the relative attitude between the master INS (MINS) and the slave INS (SINS), by decomposing the attitude matrix of the latter. Based on the Rodriguez parameters, a unified alignment model in the inertial frame with the linear state-space equation and a second order nonlinear measurement equation are established, without making any assumptions about the misalignment angles. Furthermore, we employ the Taylor series expansions on the second-order nonlinear measurement equation to implement the second-order extended Kalman filter (EKF2). Monte-Carlo simulations demonstrate that the initial alignment can be fulfilled within 10 s, with higher accuracy and much smaller computational cost compared with the traditional unscented Kalman filter (UKF) at large misalignment angles.

  13. Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

    Science.gov (United States)

    Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

    2016-03-29

    Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

  14. Brief narrative exposure therapy for posttraumatic stress in Iraqi refugees: a preliminary randomized clinical trial.

    Science.gov (United States)

    Hijazi, Alaa M; Lumley, Mark A; Ziadni, Maisa S; Haddad, Luay; Rapport, Lisa J; Arnetz, Bengt B

    2014-06-01

    Many Iraqi refugees suffer from posttraumatic stress. Efficient, culturally sensitive interventions are needed, and so we adapted narrative exposure therapy into a brief version (brief NET) and tested its effects in a sample of traumatized Iraqi refugees. Iraqi refugees in the United States reporting elevated posttraumatic stress (N = 63) were randomized to brief NET or waitlist control conditions in a 2:1 ratio; brief NET was 3 sessions, conducted individually, in Arabic. Positive indicators (posttraumatic growth and well-being) and symptoms (posttraumatic stress, depressive, and somatic) were assessed at baseline and 2- and 4-month follow-up. Treatment participation (95.1% completion) and study retention (98.4% provided follow-up data) were very high. Significant condition by time interactions showed that those receiving brief NET had greater posttraumatic growth (d = 0.83) and well-being (d = 0.54) through 4 months than controls. Brief NET reduced symptoms of posttraumatic stress (d = -0.48) and depression (d = -0.46) more, but only at 2 months; symptoms of controls also decreased from 2 to 4 months, eliminating condition differences at 4 months. Three sessions of brief NET increased growth and well-being and led to symptom reduction in highly traumatized Iraqi refugees. This preliminary study suggests that brief NET is both acceptable and potentially efficacious in traumatized Iraqi refugees. Copyright © 2014 International Society for Traumatic Stress Studies.

  15. Single-session gamified virtual reality exposure therapy for spider phobia vs. traditional exposure therapy: study protocol for a randomized controlled non-inferiority trial.

    Science.gov (United States)

    Miloff, Alexander; Lindner, Philip; Hamilton, William; Reuterskiöld, Lena; Andersson, Gerhard; Carlbring, Per

    2016-02-02

    Traditional one-session exposure therapy (OST) in which a patient is gradually exposed to feared stimuli for up to 3 h in a one-session format has been found effective for the treatment of specific phobias. However, many individuals with specific phobia are reluctant to seek help, and access to care is lacking due to logistic challenges of accessing, collecting, storing, and/or maintaining stimuli. Virtual reality (VR) exposure therapy may improve upon existing techniques by facilitating access, decreasing cost, and increasing acceptability and effectiveness. The aim of this study is to compare traditional OST with in vivo spiders and a human therapist with a newly developed single-session gamified VR exposure therapy application with modern VR hardware, virtual spiders, and a virtual therapist. Participants with specific phobia to spiders (N = 100) will be recruited from the general public, screened, and randomized to either VR exposure therapy (n = 50) or traditional OST (n = 50). A behavioral approach test using in vivo spiders will serve as the primary outcome measure. Secondary outcome measures will include spider phobia questionnaires and self-reported anxiety, depression, and quality of life. Outcomes will be assessed using a non-inferiority design at baseline and at 1, 12, and 52 weeks after treatment. VR exposure therapy has previously been evaluated as a treatment for specific phobias, but there has been a lack of high-quality randomized controlled trials. A new generation of modern, consumer-ready VR devices is being released that are advancing existing technology and have the potential to improve clinical availability and treatment effectiveness. The VR medium is also particularly suitable for taking advantage of recent phobia treatment research emphasizing engagement and new learning, as opposed to physiological habituation. This study compares a market-ready, gamified VR spider phobia exposure application, delivered using consumer VR hardware, with

  16. Waiting time analysis for MX/G/1 priority queues with/without vacations under random order of service discipline

    Directory of Open Access Journals (Sweden)

    Norikazu Kawasaki

    2000-01-01

    Full Text Available We study MX/G/1 nonpreemptive and preemptive-resume priority queues with/without vacations under random order of service (ROS discipline within each class. By considering the conditional waiting times given the states of the system, which an arbitrary message observes upon arrival, we derive the Laplace-Stieltjes transforms of the waiting time distributions and explicitly obtain the first two moments. The relationship for the second moments under ROS and first-come first-served disciplines extends the one found previously by Takacs and Fuhrmann for non-priority single arrival queues.

  17. The Relationship of Dynamical Heterogeneity to the Adam-Gibbs and Random First-Order Transition Theories of Glass Formation

    OpenAIRE

    Starr, Francis W.; Douglas, Jack F.; Sastry, Srikanth

    2013-01-01

    We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and stri...

  18. Fixed, low radiant exposure vs. incremental radiant exposure approach for diode laser hair reduction: a randomized, split axilla, comparative single-blinded trial.

    Science.gov (United States)

    Pavlović, M D; Adamič, M; Nenadić, D

    2015-12-01

    Diode lasers are the most commonly used treatment modalities for unwanted hair reduction. Only a few controlled clinical trials but not a single randomized controlled trial (RCT) compared the impact of various laser parameters, especially radiant exposure, onto efficacy, tolerability and safety of laser hair reduction. To compare the safety, tolerability and mid-term efficacy of fixed, low and incremental radiant exposures of diode lasers (800 nm) for axillary hair removal, we conducted an intrapatient, left-to-right, patient- and assessor-blinded and controlled trial. Diode laser (800 nm) treatments were evaluated in 39 study participants (skin type II-III) with unwanted axillary hairs. Randomization and allocation to split axilla treatments were carried out by a web-based randomization tool. Six treatments were performed at 4- to 6-week intervals with study subjects blinded to the type of treatment. Final assessment of hair reduction was conducted 6 months after the last treatment by means of blinded 4-point clinical scale using photographs. The primary endpoint was reduction in hair growth, and secondary endpoints were patient-rated tolerability and satisfaction with the treatment, treatment-related pain and adverse effects. Excellent reduction in axillary hairs (≥ 76%) at 6-month follow-up visit after receiving fixed, low and incremental radiant exposure diode laser treatments was obtained in 59% and 67% of study participants respectively (Z value: 1.342, P = 0.180). Patients reported lower visual analogue scale (VAS) pain score on the fixed (4.26) than on the incremental radiant exposure side (5.64) (P diode laser treatments were less painful and better tolerated. © 2015 European Academy of Dermatology and Venereology.

  19. Spatiotemporal prediction of daily ambient ozone levels across China using random forest for human exposure assessment.

    Science.gov (United States)

    Zhan, Yu; Luo, Yuzhou; Deng, Xunfei; Grieneisen, Michael L; Zhang, Minghua; Di, Baofeng

    2018-02-01

    In China, ozone pollution shows an increasing trend and becomes the primary air pollutant in warm seasons. Leveraging the air quality monitoring network, a random forest model is developed to predict the daily maximum 8-h average ozone concentrations ([O 3 ] MDA8 ) across China in 2015 for human exposure assessment. This model captures the observed spatiotemporal variations of [O 3 ] MDA8 by using the data of meteorology, elevation, and recent-year emission inventories (cross-validation R 2  = 0.69 and RMSE = 26 μg/m 3 ). Compared with chemical transport models that require a plenty of variables and expensive computation, the random forest model shows comparable or higher predictive performance based on only a handful of readily-available variables at much lower computational cost. The nationwide population-weighted [O 3 ] MDA8 is predicted to be 84 ± 23 μg/m 3 annually, with the highest seasonal mean in the summer (103 ± 8 μg/m 3 ). The summer [O 3 ] MDA8 is predicted to be the highest in North China (125 ± 17 μg/m 3 ). Approximately 58% of the population lives in areas with more than 100 nonattainment days ([O 3 ] MDA8 >100 μg/m 3 ), and 12% of the population are exposed to [O 3 ] MDA8 >160 μg/m 3 (WHO Interim Target 1) for more than 30 days. As the most populous zones in China, the Beijing-Tianjin Metro, Yangtze River Delta, Pearl River Delta, and Sichuan Basin are predicted to be at 154, 141, 124, and 98 nonattainment days, respectively. Effective controls of O 3 pollution are urgently needed for the highly-populated zones, especially the Beijing-Tianjin Metro with seasonal [O 3 ] MDA8 of 140 ± 29 μg/m 3 in summer. To the best of the authors' knowledge, this study is the first statistical modeling work of ambient O 3 for China at the national level. This timely and extensively validated [O 3 ] MDA8 dataset is valuable for refining epidemiological analyses on O 3 pollution in China. Copyright © 2017 Elsevier Ltd. All rights

  20. Optimal Order of Successive Office Hysteroscopy and Endometrial Biopsy for the Evaluation of Abnormal Uterine Bleeding: A Randomized Controlled Trial.

    Science.gov (United States)

    Sarkar, Papri; Mikhail, Emad; Schickler, Robyn; Plosker, Shayne; Imudia, Anthony N

    2017-09-01

    To estimate the optimal order of office hysteroscopy and endometrial biopsy when performed successively for evaluation of abnormal uterine bleeding. Patients undergoing successive office hysteroscopy and endometrial biopsy were included in a single-blind, prospective, randomized trial. The primary outcome was to evaluate the effect of order of procedures on patients' pain score. Prespecified secondary outcomes include procedure duration, hysteroscopic visualization of the uterine cavity, endometrial sample adequacy, and number of attempts at biopsy. Pain scores were assessed using a visual analog scale from 0 to 10 and endometrial sample adequacy was determined from the histopathology report. Hysteroscopy images were recorded. Sample size of 34 per group (n=68) was determined to be adequate to detect a difference of 20% in visual analog scale score between hysteroscopy first (group A) and biopsy first (group B) at α of 0.05 and 80% power. Between October 2015 and January 2017, 78 women were randomized to group A (n=40) and group B (n=38). There was no difference in global pain perception [7 (0-10) vs 7 (0-10); P=.57, 95% CI 5.8-7.1]. Procedure duration [3 (1-9) vs 3 (2-10), P=.32, 95% CI 3.3-4.1] and endometrial sample adequacy (78.9% vs 75.7%, P=.74) were similar in both groups. Group A patients had better endometrial visualization (Pabnormal uterine bleeding, the global pain perception, and time required are independent of the order in which procedures are performed. Performing hysteroscopy first ensures better image, whereas biopsy first yields adequate tissue sample with fewer attempts. ClinicalTrials.gov, NCT02472184.

  1. Randomization of grab-sampling strategies for estimating the annual exposure of U miners to Rn daughters.

    Science.gov (United States)

    Borak, T B

    1986-04-01

    Periodic grab sampling in combination with time-of-occupancy surveys has been the accepted procedure for estimating the annual exposure of underground U miners to Rn daughters. Temporal variations in the concentration of potential alpha energy in the mine generate uncertainties in this process. A system to randomize the selection of locations for measurement is described which can reduce uncertainties and eliminate systematic biases in the data. In general, a sample frequency of 50 measurements per year is sufficient to satisfy the criteria that the annual exposure be determined in working level months to within +/- 50% of the true value with a 95% level of confidence. Suggestions for implementing this randomization scheme are presented.

  2. Overcoming Barriers to Disseminating Exposure Therapies for Anxiety Disorders: A Pilot Randomized Controlled Trial of Training Methods

    OpenAIRE

    Harned, Melanie S.; Dimeff, Linda A.; Woodcock, Eric A.; Skutch, Julie M.

    2011-01-01

    The present study evaluated methods for training mental health providers (N=46) in exposure therapies (ETs) for anxiety disorders. A pilot randomized controlled trial compared: 1) an interactive, multimedia online training (ET OLT), 2) the ET OLT plus a brief Motivational Interviewing-based intervention (ET OLT + MI), and 3) a placebo control OLT. Assessments were completed at baseline, post-training, and one week following training. Both ET OLT and ET OLT + MI received high satisfaction rati...

  3. Encouraging GPs to undertake screening and a brief intervention in order to reduce problem drinking: a randomized controlled trial

    DEFF Research Database (Denmark)

    Hansen, Lars Jørgen; Olivarius, Niels de Fine; Beich, Anders

    1999-01-01

    intervention, problem drinking, randomized controlled trial, family practice, marketing of health services......intervention, problem drinking, randomized controlled trial, family practice, marketing of health services...

  4. A randomized controlled study of power posing before public speaking exposure for social anxiety disorder: No evidence for augmentative effects.

    Science.gov (United States)

    Davis, Michelle L; Papini, Santiago; Rosenfield, David; Roelofs, Karin; Kolb, Sarah; Powers, Mark B; Smits, Jasper A J

    2017-12-01

    This manuscript details a randomized controlled study designed to test the efficacy of power posing (i.e., briefly holding postures associated with dominance and power) as an augmentative strategy for exposure therapy for social anxiety disorder (SAD). Seventy-three individuals diagnosed with SAD were assigned to one of three conditions: power posing, submissive posing, or rest (no posing) prior to participating in an exposure therapy session. Participants were assessed for between-group differences in pre- and post-manipulation salivary hormone levels, within-session subjective experiences of fear, and pre- and 1-week post-treatment SAD severity outcome measures. Though the intervention resulted in decreased SAD symptom severity one week later, analyses revealed no significant between-group differences on any tested variables. Accordingly, this study provides no evidence to suggest that power posing impacts hormone levels or exposure therapy outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. A multi-tier higher order Conditional Random Field for land cover classification of multi-temporal multi-spectral Landsat imagery

    CSIR Research Space (South Africa)

    Salmon, BP

    2015-07-01

    Full Text Available In this paper the authors present a 2-tier higher order Conditional Random Field which is used for land cover classification. The Conditional Random Field is based on probabilistic messages being passed along a graph to compute efficiently...

  6. Mendelian randomization analysis of a time-varying exposure for binary disease outcomes using functional data analysis methods.

    Science.gov (United States)

    Cao, Ying; Rajan, Suja S; Wei, Peng

    2016-12-01

    A Mendelian randomization (MR) analysis is performed to analyze the causal effect of an exposure variable on a disease outcome in observational studies, by using genetic variants that affect the disease outcome only through the exposure variable. This method has recently gained popularity among epidemiologists given the success of genetic association studies. Many exposure variables of interest in epidemiological studies are time varying, for example, body mass index (BMI). Although longitudinal data have been collected in many cohort studies, current MR studies only use one measurement of a time-varying exposure variable, which cannot adequately capture the long-term time-varying information. We propose using the functional principal component analysis method to recover the underlying individual trajectory of the time-varying exposure from the sparsely and irregularly observed longitudinal data, and then conduct MR analysis using the recovered curves. We further propose two MR analysis methods. The first assumes a cumulative effect of the time-varying exposure variable on the disease risk, while the second assumes a time-varying genetic effect and employs functional regression models. We focus on statistical testing for a causal effect. Our simulation studies mimicking the real data show that the proposed functional data analysis based methods incorporating longitudinal data have substantial power gains compared to standard MR analysis using only one measurement. We used the Framingham Heart Study data to demonstrate the promising performance of the new methods as well as inconsistent results produced by the standard MR analysis that relies on a single measurement of the exposure at some arbitrary time point. © 2016 WILEY PERIODICALS, INC.

  7. Reduction of seizure occurrence from exposure to auditory stimulation in individuals with neurological handicaps: a randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Mark Bodner

    Full Text Available The purpose of this work was to determine in a clinical trial the efficacy of reducing or preventing seizures in patients with neurological handicaps through sustained cortical activation evoked by passive exposure to a specific auditory stimulus (particular music. The specific type of stimulation had been determined in previous studies to evoke anti-epileptiform/anti-seizure brain activity.The study was conducted at the Thad E. Saleeby Center in Harstville, South Carolina, which is a permanent residence for individuals with heterogeneous neurological impairments, many with epilepsy. We investigated the ability to reduce or prevent seizures in subjects through cortical stimulation from sustained passive nightly exposure to a specific auditory stimulus (music in a three-year randomized controlled study. In year 1, baseline seizure rates were established. In year 2, subjects were randomly assigned to treatment and control groups. Treatment group subjects were exposed during sleeping hours to specific music at regular intervals. Control subjects received no music exposure and were maintained on regular anti-seizure medication. In year 3, music treatment was terminated and seizure rates followed. We found a significant treatment effect (p = 0.024 during the treatment phase persisting through the follow-up phase (p = 0.002. Subjects exposed to treatment exhibited a significant 24% decrease in seizures during the treatment phase, and a 33% decrease persisting through the follow-up phase. Twenty-four percent of treatment subjects exhibited a complete absence of seizures during treatment.Exposure to specific auditory stimuli (i.e. music can significantly reduce seizures in subjects with a range of epilepsy and seizure types, in some cases achieving a complete cessation of seizures. These results are consistent with previous work showing reductions in epileptiform activity from particular music exposure and offers potential for achieving a non

  8. Transient modeling of non-Fickian transport and first-order reaction using continuous time random walk

    Science.gov (United States)

    Burnell, Daniel K.; Hansen, Scott K.; Xu, Jie

    2017-09-01

    Contaminants in groundwater may experience a broad spectrum of velocities and multiple rates of mass transfer between mobile and immobile zones during transport. These conditions may lead to non-Fickian plume evolution which is not well described by the advection-dispersion equation (ADE). Simultaneously, many groundwater contaminants are degraded by processes that may be modeled as first-order decay. It is now known that non-Fickian transport and reaction are intimately coupled, with reaction affecting the transport operator. However, closed-form solutions for these important scenarios have not been published for use in applications. In this paper, we present four new Green's function analytic solutions in the uncoupled, uncorrelated continuous time random walk (CTRW) framework for reactive non-Fickian transport, corresponding to the quartet of conservative tracer solutions presented by Kreft and Zuber (1978) for Fickian transport. These consider pulse injection for both resident and flux concentration combined with detection in both resident and flux concentration. A pair of solutions for resident concentration temporal pulses with detection in both flux and resident concentration is also presented. We also derive the relationship between flux and resident concentration for non-Fickian transport with first-order reaction for this CTRW formulation. An explicit discussion of employment of the new solutions to model transport with arbitrary upgradient boundary conditions as well as mobile-immobile mass transfer is then presented. Using the new solutions, we show that first-order reaction has no effect on the anomalous spatial spreading rate of concentration profiles, but produces breakthrough curves at fixed locations that appear to have been generated by Fickian transport. Under the assumption of a Pareto CTRW transition distribution, we present a variety of numerical simulations including results showing coherence of our analytic solutions and CTRW particle

  9. Yohimbine Enhancement of Exposure Therapy for Social Anxiety Disorder: A Randomized Controlled Trial

    NARCIS (Netherlands)

    Smits, J.A.J.; Rosenfield, D.; Davis, M.L.; Julian, K.; Handelsman, P.R.; Otto, M.W.; Tuerk, P.; Shiekh, M.; Rosenfield, B.; Hofmann, S.G.; Powers, M.B.

    2014-01-01

    Background Preclinical and clinical trials suggest that yohimbine may augment extinction learning without significant side effects. However, previous clinical trials have only examined adults with specific phobias. Yohimbine has not yet been investigated in the augmentation of exposure therapy for

  10. Therapist-Aided Exposure for Women with Lifelong Vaginismus: Mediators of Treatment Outcome: A Randomized Waiting List Control Trial.

    Science.gov (United States)

    Ter Kuile, Moniek M; Melles, Reinhilde J; Tuijnman-Raasveld, Charlotte C; de Groot, Helen E; van Lankveld, Jacques J D M

    2015-08-01

    Therapist-aided exposure seems an effective treatment for lifelong vaginismus, but mechanisms of action have not yet been established. The purpose of the present study was to investigate whether treatment outcome of a therapist-aided exposure treatment was mediated by changes in positive and negative penetration beliefs or feelings of sexual disgust. Participants with lifelong vaginismus were allocated at random to a 3-month exposure (n = 35) or a waiting list control condition (n = 35). Full intercourse was assessed daily during 12 weeks. Secondary outcome measures (complaints about vaginismus and coital pain) were assessed at baseline and after 12 weeks. Possible mediators: penetration beliefs (catastrophic pain beliefs, genital incompatibility beliefs, perceived control beliefs) and feelings of sexual disgust were assessed at baseline and 6 weeks. Treatment outcome (coital frequency, symptoms of vaginismus, and coital pain) at 12 weeks was mediated by changes in negative and positive penetration beliefs at 6 weeks, in particular by more pronounced reduction of catastrophic pain penetration beliefs. No evidence was found that changes in feelings of sexual disgust mediated treatment outcome. The results strongly suggest that therapist-aided exposure affects negative penetration beliefs and that these changes in negative penetration beliefs mediate treatment outcome in women with lifelong vaginismus. Implications for treatment are discussed. © 2015 International Society for Sexual Medicine.

  11. E-learning in order to improve drug prescription for hospitalized older patients: a cluster-randomized controlled study.

    Science.gov (United States)

    Franchi, Carlotta; Tettamanti, Mauro; Djade, Codjo Dgnefa; Pasina, Luca; Mannucci, Pier Mannuccio; Onder, Graziano; Gussoni, Gualberto; Manfellotto, Dario; Bonassi, Stefano; Salerno, Francesco; Nobili, Alessandro

    2016-07-01

    The aim of the study was to evaluate the effect of an e-learning educational program meant to foster the quality of drug prescription in hospitalized elderly patients. Twenty geriatric and internal medicine wards were randomized to intervention (e-learning educational program) or control (basic geriatric pharmacology notions). Logistic regression analysis was used in order to assess the effect of the intervention on the use of potentially inappropriate medication (PIM, primary outcome) at hospital discharge. Secondary outcomes were a reduced prevalence of at least one potential drug-drug interaction (DDI) and potentially severe DDI at discharge. Mortality rate and incidence of re-hospitalizations were other secondary outcomes assessed at the 12-month follow-up. A total of 697 patients (347 in the intervention and 350 in the control arms) were enrolled. No difference in the prevalence of PIM at discharge was found between arms (OR 1.29 95%CI 0.87-1.91). We also found no decrease in the prevalence of DDI (OR 0.67 95%CI 0.34-1.28) and potentially severe DDI (OR 0.86 95%CI 0.63-1.15) at discharge, nor in mortality rates and incidence of re-hospitalization at 12-month follow-up. This e-learning educational program had no clear effect on the quality of drug prescription and clinical outcomes in hospitalized elderly patients. Given the high prevalence of PIMs and potential DDIs recorded in the frame of this study, other approaches should be developed in order to improve the quality of drug prescription in this population. © 2016 The British Pharmacological Society.

  12. A Randomized, Controlled Trial of Meditation Compared to Exposure Therapy and Education Control on PTSD in Veterans

    Science.gov (United States)

    2015-10-01

    score >45. Exclusion criteria: Service related trauma within last 3 months, history of schizophrenia, bipolar disorder , dementia, moderate or severe...7.7% 0.0% 8.3% 0.191 Bipolar disorder , % 7.7% 10.3% 13.9% 0.681 Substance use disorder , % 30.8% 43.6% 41.7% 0.458 Major depressive disorder ...Award Number: W81XWH-12-1-0576 TITLE: A Randomized, Controlled Trial of Meditation Compared to Exposure Therapy and Education Control on PTSD in

  13. A randomized controlled Alzheimer's disease prevention trial's evolution into an exposure trial: the PREADViSE Trial.

    Science.gov (United States)

    Kryscio, R J; Abner, E L; Schmitt, F A; Goodman, P J; Mendiondo, M; Caban-Holt, A; Dennis, B C; Mathews, M; Klein, E A; Crowley, J J

    2013-01-01

    To summarize the ongoing prevention of Alzheimer's disease (AD) by vitamin E and selenium (PREADViSE) trial as an ancillary study to SELECT (a large prostate cancer prevention trial) and to present the blinded results of the first year as an exposure study. PREADViSE was designed as a double blind randomized controlled trial (RCT). SELECT terminated after median of 5.5 years of exposure to supplements due to a futility analysis. Both trials then converted into an exposure study. In the randomized component PREADViSE enrolled 7,547 men age 62 or older (60 if African American). Once the trial terminated 4,246 of these men volunteered for the exposure study. Demographics were similar for both groups with exposure volunteers having baseline mean age 67.3 ± 5.2 years, 15.3 ± 2.4 years of education, 9.8% African Americans, and 22.0% reporting a family history of dementia. In the RCT men were randomly assigned to either daily doses of 400 IU of vitamin E or placebo and 200 µg of selenium or placebo using a 2x2 factorial structure. In the RCT, participants completed the memory impairment screen (MIS), and if they failed, underwent a longer screening (based on an expanded Consortium to Establish a Registry in AD [CERAD] battery). CERAD failure resulted in visits to their clinician for medical examination with records of these examinations forwarded to the PREADViSE center for further review. In the exposure study, men are contacted by telephone and complete the telephone version of the memory impairment screen (MIS-T) screen. If they fail the MIS-T, a modified telephone interview of cognitive status (TICS-M) exam is given. A failed TICS-M exam also leads to a visit to their clinician for an in-depth examination and forwarding of records for a centralized consensus diagnosis by expert clinicians. A subgroup of the men who pass the MIS-T also take the TICS-M exam for validation purposes. While this ancillary trial was open to all 427 SELECT clinical sites, only 130 (30

  14. Influence of Teaching Strategies and its Order of Exposure on Pre-Clinical Teeth Arrangement - A Pilot Study.

    Science.gov (United States)

    Jeyapalan, Karthigeyan; Mani, Uma Maheswari; Christian, Jayanth; Seenivasan, Madhan Kumar; Natarajan, Parthasarathy; Vaidhyanathan, Anand Kumar

    2016-10-01

    Teeth arrangement is a vital skill for the undergraduate dental student. The attainment of skills depends largely on the methodology of teaching. In a dental curriculum, the students are exposed to a wide variety of inputs and teaching methodologies from different sources. The educational unit in dental school must identify the sequence of teaching methods that enhance the learning and practising ability of students. The aim of this study was to evaluate the effectiveness of three different teaching methodologies for teeth arrangement and compare the differences between the orders of exposure to each teaching methodology on the development of teeth arrangement skills. The first year B.D.S students were study participants and were divided into three groups A, B, C. They were exposed to three teaching patterns namely live demonstration with video assisted teaching, group discussion with hand-outs and lectures with power point presentation. After each teaching methodology, their skill was assessed. The groups were exposed to three methodologies in different order for three arrangements. The scores obtained were analysed using Kruskal Wallis rank sum test and Dunn test for statistical significance. Significantly higher scores in the teeth arrangement procedure were obtained by the Group A students who were exposed initially to live demonstration with video-assisted teaching. Difference in the scores was noted among and within the groups. The difference between Group A and Group C was statistically significant after both first and third teeth arrangement (p=0.0031, p=0.0057). The study suggests each pre-clinical practice should begin with a live demonstration to enhance immediate learning absorption followed by lectures with power point presentation and group discussion for retention of knowledge and memory retrieval.

  15. Partitioning of fresh crude oil between floating, dispersed and sediment phases: Effect of exposure order to dispersant and granular materials.

    Science.gov (United States)

    Boglaienko, Daria; Tansel, Berrin

    2016-06-15

    When three or more high and low energy substrates are mixed, wetting order can significantly affect the behavior of the mixture. We analyzed the phase distribution of fresh floating Louisiana crude oil into dispersed, settled and floating phases depending on the exposure sequence to Corexit 9500A (dispersant) and granular materials. In the experiments artificial sea water at salinity 34‰ was used. Limestone (2.00-0.300 mm) and quartz sand (0.300-0.075 mm) were used as the natural granular materials. Dispersant Corexit 9500A increased the amount of dispersed oil up to 33.76 ± 7.04%. Addition of granular materials after the dispersant increased dispersion of oil to 47.96 ± 1.96%. When solid particles were applied on the floating oil before the dispersant, oil was captured as oil-particle aggregates and removed from the floating layer. However, dispersant addition led to partial release of the captured oil, removing it from the aggregated form to the dispersed and floating phases. There was no visible oil aggregation with the granular materials when quartz or limestone was at the bottom of the flask before the addition of oil and dispersant. The results show that granular materials can be effective when applied from the surface for aggregating or dispersing oil. However, the granular materials in the sediments are not effective neither for aggregating nor dispersing floating oil. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Cue exposure therapy for the treatment of opiate addiction: results of a randomized controlled clinical trial

    NARCIS (Netherlands)

    Marissen, Marlies A. E.; Franken, Ingmar H. A.; Blanken, Peter; van den Brink, Wim; Hendriks, Vincent M.

    2007-01-01

    BACKGROUND: Persistent cue reactivity to drug-related stimuli is a well-known phenomenon among abstinent drug users and has been found to be a predictor of relapse. Cue exposure therapy (CET) aims to reduce this cue reactivity by exposing abstinent drug users to conditioned drug-related stimuli

  17. The relationship of dynamical heterogeneity to the Adam-Gibbs and random first-order transition theories of glass formation.

    Science.gov (United States)

    Starr, Francis W; Douglas, Jack F; Sastry, Srikanth

    2013-03-28

    We carefully examine common measures of dynamical heterogeneity for a model polymer melt and test how these scales compare with those hypothesized by the Adam and Gibbs (AG) and random first-order transition (RFOT) theories of relaxation in glass-forming liquids. To this end, we first analyze clusters of highly mobile particles, the string-like collective motion of these mobile particles, and clusters of relative low mobility. We show that the time scale of the high-mobility clusters and strings is associated with a diffusive time scale, while the low-mobility particles' time scale relates to a structural relaxation time. The difference of the characteristic times for the high- and low-mobility particles naturally explains the well-known decoupling of diffusion and structural relaxation time scales. Despite the inherent difference of dynamics between high- and low-mobility particles, we find a high degree of similarity in the geometrical structure of these particle clusters. In particular, we show that the fractal dimensions of these clusters are consistent with those of swollen branched polymers or branched polymers with screened excluded-volume interactions, corresponding to lattice animals and percolation clusters, respectively. In contrast, the fractal dimension of the strings crosses over from that of self-avoiding walks for small strings, to simple random walks for longer, more strongly interacting, strings, corresponding to flexible polymers with screened excluded-volume interactions. We examine the appropriateness of identifying the size scales of either mobile particle clusters or strings with the size of cooperatively rearranging regions (CRR) in the AG and RFOT theories. We find that the string size appears to be the most consistent measure of CRR for both the AG and RFOT models. Identifying strings or clusters with the "mosaic" length of the RFOT model relaxes the conventional assumption that the "entropic droplets" are compact. We also confirm the

  18. A randomized noninferiority trial of standard versus enhanced risk reduction and adherence counseling for individuals receiving post-exposure prophylaxis following sexual exposures to HIV.

    Science.gov (United States)

    Roland, Michelle E; Neilands, Torsten B; Krone, Melissa R; Coates, Thomas J; Franses, Karena; Chesney, Margaret A; Kahn, James S; Martin, Jeffrey N

    2011-07-01

    The National HIV/AIDS Strategy proposes to scale-up post-exposure prophylaxis (PEP). Intensive risk reduction and adherence counseling appear to be effective but are resource intensive. Identifying simpler interventions that maximize the HIV prevention potential of PEP is critical. A randomized noninferiority study comparing 2 (standard) or 5 (enhanced) risk reduction counseling sessions was performed. Adherence counseling was provided in the enhanced arm. We measured changes in unprotected sexual intercourse acts at 12 months, compared with baseline; HIV acquisition; and PEP adherence. Outcomes were stratified by degree of baseline risk. We enrolled 457 individuals reporting unprotected intercourse within 72 h with an HIV-infected or at-risk partner. Participants were 96% male and 71% white. There were 1.8 and 2.3 fewer unprotected sex acts in the standard and enhanced groups. The maximum potential risk difference, reflected by the upper bound of the 95% confidence interval, was 3.9 acts. The difference in the riskier subset may have been as many as 19.6 acts. The incidence of HIV seroconversion was 2.9% and 2.6% among persons randomized to standard and enhanced counseling, respectively, with a maximum potential difference of 3.4%. The absolute and maximal HIV seroconversion incidence was 9.9% and 20.4% greater in the riskier group randomized to standard, compared with enhanced, counseling. Adherence outcomes were similar, with noninferiority in the lower risk group and concerning differences among the higher-risk group. Risk assessment is critical at PEP initiation. Standard counseling is only noninferior for individuals with lower baseline risk; thus, enhanced counseling should be targeted to individuals at higher risk. © The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.

  19. Baby Shampoo to Relieve the Discomfort of Tear Gas and Pepper Spray Exposure: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    James E. Winslow III

    2018-02-01

    Full Text Available Introduction: Oleoresin capsicum (OC or pepper spray, and tear gas (CS are used by police and the military and produce severe discomfort. Some have proposed that washing with baby shampoo helps reduce this discomfort. Methods: We conducted a prospective, randomized, controlled study to determine if baby shampoo is effective in reducing the severity and duration of these effects. Study subjects included volunteers undergoing OC or CS exposure as part of their police or military training. After standardized exposure to OC or CS all subjects were allowed to irrigate their eyes and skin ad lib with water. Those randomized to the intervention group were provided with baby shampoo for application to their head, neck, and face. Participants rated their subjective discomfort in two domains on a scale of 0–10 at 0, 3, 5, 10, and 15 minutes. We performed statistical analysis using a two-tailed Mann-Whitney Test. Results: There were 58 participants. Of 40 subjects in the OC arm of the study, there were no significant differences in the ocular or respiratory discomfort at any of the time points between control (n=19 and intervention (n=21 groups. Of 18 subjects in the CS arm, there were no significant differences in the ocular or skin discomfort at any of the time points between control (n=8 and intervention (n=10 groups. Conclusion: Irrigation with water and baby shampoo provides no better relief from OC- or CS-induced discomfort than irrigation with water alone.

  20. Baby Shampoo to Relieve the Discomfort of Tear Gas and Pepper Spray Exposure: A Randomized Controlled Trial.

    Science.gov (United States)

    Stopyra, Jason P; Winslow, James E; Johnson, James C; Hill, Keith D; Bozeman, William P

    2018-03-01

    Oleoresin capsicum (OC) or pepper spray, and tear gas (CS) are used by police and the military and produce severe discomfort. Some have proposed that washing with baby shampoo helps reduce this discomfort. We conducted a prospective, randomized, controlled study to determine if baby shampoo is effective in reducing the severity and duration of these effects. Study subjects included volunteers undergoing OC or CS exposure as part of their police or military training. After standardized exposure to OC or CS all subjects were allowed to irrigate their eyes and skin ad lib with water. Those randomized to the intervention group were provided with baby shampoo for application to their head, neck, and face. Participants rated their subjective discomfort in two domains on a scale of 0-10 at 0, 3, 5, 10, and 15 minutes. We performed statistical analysis using a two-tailed Mann-Whitney Test. There were 58 participants. Of 40 subjects in the OC arm of the study, there were no significant differences in the ocular or respiratory discomfort at any of the time points between control (n=19) and intervention (n=21) groups. Of 18 subjects in the CS arm, there were no significant differences in the ocular or skin discomfort at any of the time points between control (n=8) and intervention (n=10) groups. Irrigation with water and baby shampoo provides no better relief from OC- or CS-induced discomfort than irrigation with water alone.

  1. Influence of random daughter exposure rate, unattachment fraction, and disequilibrium on occurrence of lung tumors

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Dagle, G.E.; Busch, R.H.; Buschbom, R.L.

    1983-10-01

    Groups of male, specific-pathogen-free (SPF), Wistar rats were exposed to several concentrations of radon daughters and uranium ore dust to clarify the roles of exposure rate, unattached RaA daughters, and the degree of radon daughter disequilibrium, in the development of respiratory system disease. Modeled, human-dosimetric data indicate that the dose to sensitive tissues of the respiratory tract increases with increasing radon-daughter unattachment fraction and degree of disequilibrium. Experimental verification of these dose-effect relationships is needed to protect the health of workers and of the public exposed to radon-daughter environments. Data bearing on these relationships as well as updated results of experiments designed to test the role of radon-daughter exposure rate on lung-tumor incidence are reported. 13 references, 3 tables

  2. Therapist-aided exposure for women with lifelong vaginismus: a randomized waiting-list control trial of efficacy.

    Science.gov (United States)

    Ter Kuile, Moniek M; Melles, Reinhilde; de Groot, H Ellen; Tuijnman-Raasveld, Charlotte C; van Lankveld, Jacques J D M

    2013-12-01

    Vaginismus is commonly described as a persistent difficulty in allowing vaginal entry of a penis or other "objects" (e.g., tampons, fingers, speculum). Lifelong vaginismus is diagnosed when a woman has never been able to have intercourse. The aim of this study was to investigate the efficacy of therapist-aided exposure for lifelong vaginismus. Seventy women and their partners were randomly allocated to exposure or a waiting-list control period of 3 months. The main outcome measure (intercourse ability) was assessed daily during 12 weeks. Secondary outcome measures were complaints about vaginismus, coital pain, coital fear, sexual distress, and sexual functioning. The exposure treatment consisted of a maximum of three 2-hr sessions during 1 week at a university hospital. Each participant performed vaginal penetration exercises herself, in the presence of her partner and a female therapist. Two follow-up sessions were scheduled over a 5-week period. Thirty-one out of 35 (89%; 95% CI [72%, 96%]) participants reported having had sexual intercourse at posttreatment compared with 4 out of 35 (11%; 95% CI [4%, 28%]) participants in the control condition. In most of the successfully treated women (90%), intercourse was possible within the first 2 weeks of treatment. Moreover, treatment resulted in clinical improvement regarding other symptoms related to vaginismus, coital fear, coital pain, and sexual distress. No treatment effects were found regarding other aspects of sexual functioning in women or their partners. This study provides evidence of the efficacy of therapist-aided exposure therapy for women with lifelong vaginismus.

  3. Law & Order, CSI, and NCIS: The Association Between Exposure to Crime Drama Franchises, Rape Myth Acceptance, and Sexual Consent Negotiation Among College Students.

    Science.gov (United States)

    Hust, Stacey J T; Marett, Emily Garrigues; Lei, Ming; Ren, Chunbo; Ran, Weina

    2015-01-01

    Previous research has identified that exposure to the crime drama genre lowers rape myth acceptance and increases sexual assault prevention behaviors such as bystander intervention. However, recent content analyses have revealed marked differences in the portrayal of sexual violence within the top three crime drama franchises. Using a survey of 313 college freshmen, this study explores the influence of exposure to the three most popular crime drama franchises: Law & Order, CSI, and NCIS. Findings indicate that exposure to the Law & Order franchise is associated with decreased rape myth acceptance and increased intentions to adhere to expressions of sexual consent and refuse unwanted sexual activity; whereas exposure to the CSI franchise is associated with decreased intentions to seek consent and decreased intentions to adhere to expressions of sexual consent. Exposure to the NCIS franchise was associated with decreased intentions to refuse unwanted sexual activity. These results indicate that exposure to the specific content of each crime drama franchise may have differential results on sexual consent negotiation behaviors.

  4. Exploring the pullback attractors of a low-order quasigeostrophic ocean model subject to deterministic and random forcing

    Science.gov (United States)

    Ghil, M.; Pierini, S.; Chekroun, M.

    2017-12-01

    A low-order quasigeostrophic model [1] captures several key features of intrinsic low-frequency variability of the oceans' wind-driven circulation. This double-gyre model is used here as a prototype of an unstable and nonlinear dynamical system with time-dependent forcing to explore basic features of climate change in the presence of natural variability. The studies rely on the theoretical framework of nonautonomous dynamical systems and of their pullback attractors (PBAs), namely the time-dependent invariant sets that attract all trajectories initialized in the remote past [2,3]. Ensemble simulations help us explore these PBAs. The chaotic PBAs of the periodically forced model [4] are found to be cyclo-stationary and cyclo-ergodic. Two parameters are then introduced to analyze the topological structure of the PBAs as a function of the forcing period; their joint use allows one to identify four distinct forms of sensitivity to initial state that correspond to distinct types of system behavior. The model's response to periodic forcing turns out to be, in most cases, very sensitive to the initial state. The system is then forced by a synthetic aperiodic forcing [5]. The existence of a global PBA is rigorously demonstrated. We then assess the convergence of trajectories to this PBA by computing the probability density function (PDF) of trajectory localization in the model's phase space. A sensitivity analysis with respect to forcing amplitude shows that the global PBA experiences large modifications if the underlying autonomous system is dominated by small-amplitude limit cycles, while the changes are less dramatic in a regime characterized by large-amplitude relaxation oscillations. The dependence of the attracting sets on the choice of the ensemble of initial states is analyzed in detail. The extension to random dynamical systems is described and connected to the model's autonomous and periodically forced behavior. [1] Pierini, S., 2011. J. Phys. Oceanogr., 41, 1585

  5. A randomized controlled study of exposure therapy as aftercare for alcohol use disorder

    DEFF Research Database (Denmark)

    Mellentin, Angelina Isabella; Nielsen, Bent; Nielsen, Anette Søgaard

    2016-01-01

    on exposing individuals to alcohol cues in order to reduce cravings as well as the likelihood of relapse. The aims of the study are: 1) to investigate whether CET aftercare delivered via a smartphone or in group sessions increases the effect of Cognitive Behavioural Treatment in groups of alcohol dependent...... psychological treatment whenever and wherever the patient finds it convenient....

  6. Narrative exposure therapy for PTSD increases top-down processing of aversive stimuli - evidence from a randomized controlled treatment trial

    Directory of Open Access Journals (Sweden)

    Adenauer Hannah

    2011-12-01

    Full Text Available Abstract Background Little is known about the neurobiological foundations of psychotherapy for Posttraumatic Stress Disorder (PTSD. Prior studies have shown that PTSD is associated with altered processing of threatening and aversive stimuli. It remains unclear whether this functional abnormality can be changed by psychotherapy. This is the first randomized controlled treatment trial that examines whether narrative exposure therapy (NET causes changes in affective stimulus processing in patients with chronic PTSD. Methods 34 refugees with PTSD were randomly assigned to a NET group or to a waitlist control (WLC group. At pre-test and at four-months follow-up, the diagnostics included the assessment of clinical variables and measurements of neuromagnetic oscillatory brain activity (steady-state visual evoked fields, ssVEF resulting from exposure to aversive pictures compared to neutral pictures. Results PTSD as well as depressive symptom severity scores declined in the NET group, whereas symptoms persisted in the WLC group. Only in the NET group, parietal and occipital activity towards threatening pictures increased significantly after therapy. Conclusions Our results indicate that NET causes an increase of activity associated with cortical top-down regulation of attention towards aversive pictures. The increase of attention allocation to potential threat cues might allow treated patients to re-appraise the actual danger of the current situation and, thereby, reducing PTSD symptoms. Registration of the clinical trial Number: NCT00563888 Name: "Change of Neural Network Indicators Through Narrative Treatment of PTSD in Torture Victims" ULR: http://www.clinicaltrials.gov/ct2/show/NCT00563888

  7. Trauma management therapy with virtual-reality augmented exposure therapy for combat-related PTSD: A randomized controlled trial.

    Science.gov (United States)

    Beidel, Deborah C; Frueh, B Christopher; Neer, Sandra M; Bowers, Clint A; Trachik, Benjamin; Uhde, Thomas W; Grubaugh, Anouk

    2017-08-23

    Virtual reality exposure therapy (VRET) realistically incorporates traumatic cues into exposure therapy and holds promise in the treatment of combat-related posttraumatic stress disorder (PTSD). In a randomized controlled trial of 92 Iraq and Afghanistan veterans and active duty military personnel with combat-related PTSD, we compared the efficacy of Trauma Management Therapy (TMT; VRET plus a group treatment for anger, depression, and social isolation) to VRET plus a psychoeducation control condition. Efficacy was evaluated at mid- and post-treatment, and at 3- and 6-month follow-up. Consistent with our hypothesis, VRET resulted in significant decreases on the Clinician Administered PTSD Scale and the PTSD Checklist-Military version for both groups. Also consistent with our hypothesis, significant decreases in social isolation occurred only for those participants who received the TMT group component. There were significant decreases for depression and anger for both groups, although these occurred after VRET and before group treatment. All treatment gains were maintained six-months later. Although not part of the original hypotheses, sleep was not improved by either intervention and remained problematic. The results support the use of VRET as an efficacious treatment for combat-related PTSD, but suggest that VRET alone does not result in optimal treatment outcomes across domains associated with PTSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Probability calculus of fractional order and fractional Taylor's series application to Fokker-Planck equation and information of non-random functions

    International Nuclear Information System (INIS)

    Jumarie, Guy

    2009-01-01

    A probability distribution of fractional (or fractal) order is defined by the measure μ{dx} = p(x)(dx) α , 0 α (D x α h α )f(x) provided by the modified Riemann Liouville definition, one can expand a probability calculus parallel to the standard one. A Fourier's transform of fractional order using the Mittag-Leffler function is introduced, together with its inversion formula; and it provides a suitable generalization of the characteristic function of fractal random variables. It appears that the state moments of fractional order are more especially relevant. The main properties of this fractional probability calculus are outlined, it is shown that it provides a sound approach to Fokker-Planck equation which are fractional in both space and time, and it provides new results in the information theory of non-random functions.

  9. Proteome Analysis of Thyroid Cancer Cells After Long-Term Exposure to a Random Positioning Machine

    Science.gov (United States)

    Pietsch, Jessica; Bauer, Johann; Weber, Gerhard; Nissum, Mikkel; Westphal, Kriss; Egli, Marcel; Grosse, Jirka; Schönberger, Johann; Eilles, Christoph; Infanger, Manfred; Grimm, Daniela

    2011-11-01

    Annulling gravity during cell culturing triggers various types of cells to change their protein expression in a time dependent manner. We therefore decided to determine gravity sensitive proteins and their period of sensitivity to the effects of gravity. In this study, thyroid cancer cells of the ML-1 cell line were cultured under normal gravity (1 g) or in a random positioning machine (RPM), which simulated near weightlessness for 7 and 11 days. Cells were then sonicated and proteins released into the supernatant were separated from those that remained attached to the cell fragments. Subsequently, both types of proteins were fractionated by free-flow isoelectric focussing (FF-IEF). The fractions obtained were further separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to which comparable FF-IEF fractions derived from cells cultured either under 1 g or on the RPM had been applied side by side. The separation resulted in pairs of lanes, on which a number of identical bands were observed. Selected gel pieces were excised and their proteins determined by mass spectrometry. Equal proteins from cells cultured under normal gravity and the RPM, respectively, were detected in comparable gel pieces. However, many of these proteins had received different Mascot scores. Quantifying heat shock cognate 71 kDa protein, glutathione S-transferase P, nucleoside diphosphate kinase A and annexin-2 by Western blotting using whole cell lysates indicated usefulness of Mascot scores for selecting the most efficient antibodies.

  10. Narrative exposure therapy versus interpersonal psychotherapy. A pilot randomized controlled trial with Rwandan genocide orphans.

    Science.gov (United States)

    Schaal, Susanne; Elbert, Thomas; Neuner, Frank

    2009-01-01

    The aim of the present study was to evaluate the efficacy of treatment modules for trauma spectrum disorders in a sample of Rwandan genocide orphans. Twenty-six orphans (originally 27) who presented with posttraumatic stress disorder (PTSD) at first assessment continued to meet a PTSD DSM-IV diagnosis 6 months after their initial assessment. They were offered participation in a controlled treatment trial. A group adaptation of interpersonal psychotherapy (IPT, n = 14) was compared to individual narrative exposure therapy (NET, n = 12). The last NET session involved guided mourning. Each treatment program consisted of 4 weekly sessions. Main outcome measures were diagnostic status and symptoms of PTSD and depression assessed before treatment, at 3 months post-test and at 6 months follow-up using the Clinician-Administered PTSD Scale, Mini-International Neuropsychiatric Interview, and Hamilton Rating Scale. At post-test, there were no significant group differences between NET and IPT on any of the examined outcome measures. At 6-month follow-up, only 25% of NET, but 71% of IPT participants still fulfilled PTSD criteria. There was a significant time x treatment interaction in the severity of PTSD [Wilks' Lambda = 0.75, F(2,23) = 3.93; p < 0.05] and depression symptoms [Wilks' Lambda = 0.23, F(2,23) = 3.40; p = 0.05]. At follow-up, NET participants were significantly more improved than IPT participants with respect to both the severity of symptoms of PTSD and depression. Individual NET in combination with group-based mourning comprises an effective treatment for traumatized survivors who have to bear the loss of loved ones and have been suffering from symptoms of PTSD and depression. Copyright 2009 S. Karger AG, Basel.

  11. Personal child and mother carbon monoxide exposures and kitchen levels: methods and results from a randomized trial of woodfired chimney cookstoves in Guatemala (RESPIRE).

    Science.gov (United States)

    Smith, Kirk R; McCracken, John P; Thompson, Lisa; Edwards, Rufus; Shields, Kyra N; Canuz, Eduardo; Bruce, Nigel

    2010-07-01

    During the first randomized intervention trial (RESPIRE: Randomized Exposure Study of Pollution Indoors and Respiratory Effects) in air pollution epidemiology, we pioneered application of passive carbon monoxide (CO) diffusion tubes to measure long-term personal exposures to woodsmoke. Here we report on the protocols and validations of the method, trends in personal exposure for mothers and their young children, and the efficacy of the introduced improved chimney stove in reducing personal exposures and kitchen concentrations. Passive diffusion tubes originally developed for industrial hygiene applications were deployed on a quarterly basis to measure 48-hour integrated personal carbon monoxide exposures among 515 children 0-18 months of age and 532 mothers aged 15-55 years and area samples in a subsample of 77 kitchens, in households randomized into control and intervention groups. Instrument comparisons among types of passive diffusion tubes and against a continuous electrochemical CO monitor indicated that tubes responded nonlinearly to CO, and regression calibration was used to reduce this bias. Before stove introduction, the baseline arithmetic (geometric) mean 48-h child (n=270), mother (n=529) and kitchen (n=65) levels were, respectively, 3.4 (2.8), 3.4 (2.8) and 10.2 (8.4) p.p.m. The between-group analysis of the 3355 post-baseline measurements found CO levels to be significantly lower among the intervention group during the trial period: kitchen levels: -90%; mothers: -61%; and children: -52% in geometric means. No significant deterioration in stove effect was observed over the 18 months of surveillance. The reliability of these findings is strengthened by the large sample size made feasible by these unobtrusive and inexpensive tubes, measurement error reduction through instrument calibration, and a randomized, longitudinal study design. These results from the first randomized trial of improved household energy technology in a developing country and

  12. Effects of exposure to bodies of different sizes on perception of and satisfaction with own body size: two randomized studies.

    Science.gov (United States)

    Bould, Helen; Carnegie, Rebecca; Allward, Heather; Bacon, Emily; Lambe, Emily; Sapseid, Megan; Button, Katherine S; Lewis, Glyn; Skinner, Andy; Broome, Matthew R; Park, Rebecca; Harmer, Catherine J; Penton-Voak, Ian S; Munafò, Marcus R

    2018-05-01

    Body dissatisfaction is prevalent among women and associated with subsequent obesity and eating disorders. Exposure to images of bodies of different sizes has been suggested to change the perception of 'normal' body size in others. We tested whether exposure to different-sized (otherwise identical) bodies changes perception of own and others' body size, satisfaction with body size and amount of chocolate consumed. In Study 1, 90 18-25-year-old women with normal BMI were randomized into one of three groups to complete a 15 min two-back task using photographs of women either of 'normal weight' (Body Mass Index (BMI) 22-23 kg m -2 ), or altered to appear either under- or over-weight. Study 2 was identical except the 96 participants had high baseline body dissatisfaction and were followed up after 24 h. We also conducted a mega-analysis combining both studies. Participants rated size of others' bodies, own size, and satisfaction with size pre- and post-task. Post-task ratings were compared between groups, adjusting for pre-task ratings. Participants exposed to over- or normal-weight images subsequently perceived others' bodies as smaller, in comparison to those shown underweight bodies ( p  < 0.001). They also perceived their own bodies as smaller (Study 1, p  = 0.073; Study 2, p  = 0.018; mega-analysis, p  = 0.001), and felt more satisfied with their size (Study 1, p  = 0.046; Study 2, p  = 0.004; mega-analysis, p  = 0.006). There were no differences in chocolate consumption. This study suggests that a move towards using images of women with a BMI in the healthy range in the media may help to reduce body dissatisfaction, and the associated risk of eating disorders.

  13. Gender differences in first and secondhand smoke exposure, spirometric lung function and cardiometabolic health in the old order Amish: A novel population without female smoking.

    Science.gov (United States)

    Reed, Robert M; Dransfield, Mark T; Eberlein, Michael; Miller, Michael; Netzer, Giora; Pavlovich, Mary; Pollin, Toni I; Scharf, Steven M; Shuldiner, Alan R; Sin, Don; Mitchell, Braxton D

    2017-01-01

    Due to their relatively homogeneous lifestyle and living environment, the Amish offer a novel opportunity to study the health associations of tobacco smoke exposure, particularly secondhand smoke. We hypothesized that secondhand smoke exposure is associated with worse pulmonary and cardiometabolic health. We examined cross-sectional data on 3568 Amish study participants, including tobacco use and secondhand smoke exposure from family members included in the study. Thirty-four percent of Amish men reported ever smoking. Of this proportion, 64% used cigars, 46% cigarettes, and 21% pipes. Less than 1% of women reported ever smoking. Smoking was associated with lower spirometric lung function, higher body mass index, lower HDL cholesterol, higher heart rate, lower ankle-brachial index, and larger aortic diameter in men. A greater number of sources of secondhand smoke exposure (defined from the total of spouses, parents, and siblings who smoke) was associated with higher body mass index (p = 0.03) and with higher fasting glucose in men (p = 0.01), but not in women (p = 0.007 for sex*secondhand smoke interaction). Secondhand smoke exposure was also associated with reduced HDL cholesterol only in women (p = 0.002) and a lower heart rate only in men (p = 0.006). Smoking habits among the Old Order Amish are notable for the absence of female participation and a high proportion of cigar and pipe use. Smoking is associated with decreased spirometric indices of lung function and increased cardiovascular risk in this population and secondhand smoke exposure is associated with a greater burden of risk factors for cardiovascular disease. Sex differences in correlations could reflect differences in exposure patterns, mechanisms, or susceptibilities.

  14. Approximate Forward Difference Equations for the Lower Order Non-Stationary Statistics of Geometrically Non-Linear Systems subject to Random Excitation

    DEFF Research Database (Denmark)

    Köylüoglu, H. U.; Nielsen, Søren R. K.; Cakmak, A. S.

    Geometrically non-linear multi-degree-of-freedom (MDOF) systems subject to random excitation are considered. New semi-analytical approximate forward difference equations for the lower order non-stationary statistical moments of the response are derived from the stochastic differential equations...... of motion, and, the accuracy of these equations is numerically investigated. For stationary excitations, the proposed method computes the stationary statistical moments of the response from the solution of non-linear algebraic equations....

  15. The reinforcing value of vegetables does not increase with repeated exposure during a randomized controlled provided vegetable intervention among overweight and obese adults

    Science.gov (United States)

    Objective: The primary aim of this randomized controlled trial is to determine whether the relative reinforcing value (RRV) of vegetables compared to a snack food can be increased through repeated exposure (incentive sensitization) to amounts of vegetables recommended by the Dietary Guidelines for A...

  16. No Effects of D-Cycloserine Enhancement in Exposure with Response Prevention Therapy in Panic Disorder with Agoraphobia : A Double-Blind, Randomized Controlled Trial

    NARCIS (Netherlands)

    Hofmeijer-Sevink, Mieke Klein; Duits, Puck; Rijkeboer, Marleen M.; Hoogendoorn, Adriaan W; Van Megen, Harold J.; Vulink, Nienke C.; Denys, Damiaan A.; Van Den Hout, Marcel A.; van Balkom, Anton J L M; Cath, Danielle C.

    2017-01-01

    Purpose/Background D-cycloserine (DCS) is a partial N-methyl-D-aspartate receptor agonist that potentially augments response to exposure therapy in anxiety disorders by enhancing extinction learning. This randomized, double-blinded, placebo-controlled augmentation trial examined (1) the

  17. No Effects of D-Cycloserine Enhancement in Exposure With Response Prevention Therapy in Panic Disorder With Agoraphobia : A Double-Blind, Randomized Controlled Trial

    NARCIS (Netherlands)

    Hofmeijer-Sevink, Mieke Klein; Duits, Puck; Rijkeboer, Marleen M; Hoogendoorn, Adriaan W; van Megen, Harold J; Vulink, Nienke C; Denys, D.; van den Hout, Marcel A; van Balkom, Anton J L M; Cath, Danielle C

    2017-01-01

    PURPOSE/BACKGROUND: D-cycloserine (DCS) is a partial N-methyl-D-aspartate receptor agonist that potentially augments response to exposure therapy in anxiety disorders by enhancing extinction learning. This randomized, double-blinded, placebo-controlled augmentation trial examined (1) the

  18. No Effects of D-Cycloserine Enhancement in Exposure With Response Prevention Therapy in Panic Disorder With Agoraphobia : A Double-Blind, Randomized Controlled Trial

    NARCIS (Netherlands)

    Hofmeijer-Sevink, Mieke Klein; Duits, Puck; Rijkeboer, Marleen M.; Hoogendoorn, Adriaan W.; van Megen, Harold J.; Vulink, Nienke C.; Denys, Damiaan A.; van den Hout, Marcel A.; van Balkom, Anton J.; Cath, Danielle C.

    2017-01-01

    Purpose/Background: D-cycloserine (DCS) is a partial N-methyl-Daspartate receptor agonist that potentially augments response to exposure therapy in anxiety disorders by enhancing extinction learning. This randomized, double-blinded, placebo-controlled augmentation trial examined (1) the

  19. No Effects of D-Cycloserine Enhancement in Exposure With Response Prevention Therapy in Panic Disorder With Agoraphobia A Double-Blind, Randomized Controlled Trial

    NARCIS (Netherlands)

    Hofmeijer-Sevink, Mieke Klein; Duits, Puck; Rijkeboer, Marleen M.; Hoogendoorn, Adriaan W.; van Megen, Harold J.; Vulink, Nienke C.; Denys, Damiaan A.; van den Hout, Marcel A.; van Balkom, Anton J.; Cath, Danielle C.

    2017-01-01

    Purpose/Background: D-cycloserine (DCS) is a partial N-methyl-Daspartate receptor agonist that potentially augments response to exposure therapy in anxiety disorders by enhancing extinction learning. This randomized, double-blinded, placebo-controlled augmentation trial examined (1) the

  20. Hierarchical random additive process and logarithmic scaling of generalized high order, two-point correlations in turbulent boundary layer flow

    Science.gov (United States)

    Yang, X. I. A.; Marusic, I.; Meneveau, C.

    2016-06-01

    Townsend [Townsend, The Structure of Turbulent Shear Flow (Cambridge University Press, Cambridge, UK, 1976)] hypothesized that the logarithmic region in high-Reynolds-number wall-bounded flows consists of space-filling, self-similar attached eddies. Invoking this hypothesis, we express streamwise velocity fluctuations in the inertial layer in high-Reynolds-number wall-bounded flows as a hierarchical random additive process (HRAP): uz+=∑i=1Nzai . Here u is the streamwise velocity fluctuation, + indicates normalization in wall units, z is the wall normal distance, and ai's are independently, identically distributed random additives, each of which is associated with an attached eddy in the wall-attached hierarchy. The number of random additives is Nz˜ln(δ /z ) where δ is the boundary layer thickness and ln is natural log. Due to its simplified structure, such a process leads to predictions of the scaling behaviors for various turbulence statistics in the logarithmic layer. Besides reproducing known logarithmic scaling of moments, structure functions, and correlation function [" close="]3/2 uz(x ) uz(x +r ) >, new logarithmic laws in two-point statistics such as uz4(x ) > 1 /2, 1/3, etc. can be derived using the HRAP formalism. Supporting empirical evidence for the logarithmic scaling in such statistics is found from the Melbourne High Reynolds Number Boundary Layer Wind Tunnel measurements. We also show that, at high Reynolds numbers, the above mentioned new logarithmic laws can be derived by assuming the arrival of an attached eddy at a generic point in the flow field to be a Poisson process [Woodcock and Marusic, Phys. Fluids 27, 015104 (2015), 10.1063/1.4905301]. Taken together, the results provide new evidence supporting the essential ingredients of the attached eddy hypothesis to describe streamwise velocity fluctuations of large, momentum transporting eddies in wall-bounded turbulence, while observed deviations suggest the need for further extensions of the

  1. An MGF-based unified framework to determine the joint statistics of partial sums of ordered i.n.d. random variables

    KAUST Repository

    Nam, Sungsik

    2014-08-01

    The joint statistics of partial sums of ordered random variables (RVs) are often needed for the accurate performance characterization of a wide variety of wireless communication systems. A unified analytical framework to determine the joint statistics of partial sums of ordered independent and identically distributed (i.i.d.) random variables was recently presented. However, the identical distribution assumption may not be valid in several real-world applications. With this motivation in mind, we consider in this paper the more general case in which the random variables are independent but not necessarily identically distributed (i.n.d.). More specifically, we extend the previous analysis and introduce a new more general unified analytical framework to determine the joint statistics of partial sums of ordered i.n.d. RVs. Our mathematical formalism is illustrated with an application on the exact performance analysis of the capture probability of generalized selection combining (GSC)-based RAKE receivers operating over frequency-selective fading channels with a non-uniform power delay profile. © 1991-2012 IEEE.

  2. Enhancement of exposure therapy in participants with specific phobia: A randomized controlled trial comparing yohimbine, propranolol and placebo.

    Science.gov (United States)

    Meyerbröker, K; Morina, N; Emmelkamp, P M G

    2018-05-04

    Recent research indicates that pharmacological agents may enhance psychotherapeutic outcome. Yet, empirical results have not been conclusive with respect to two pharmacological agents, yohimbine hydrochloride (YOH) and propranolol. YOH is suggested to enhance emotional memory by elevating norepinephrine, whereas the β-adrenergic receptor antagonist propranolol might help better cope with feared situations by reducing accompanying bodily sensations. In this controlled trial, fifty-six participants with specific phobia were randomly assigned to either 1) virtual reality exposure therapy (VRET) plus YOH, 2) VRET plus Propranolol, or 3) VRET plus placebo. Participants in all conditions received three sessions of VRET over a period of two weeks. We conducted 2 × 3 repeated measures MANOVA's. Results showed a significant effect for time, with partial eta squared ranging from ηp2 = 0.647 to ηp2 = 0.692, for specific phobia, yet no significant interaction effects were found. No significant differences were found when VRET with YOH or a beta-blocker was compared to VRET with a non-active placebo. Implications for clinical practice and future research are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Influence of second-order random wave kinematics on the design loads of offshore wind turbine support structures

    DEFF Research Database (Denmark)

    Natarajan, Anand

    2014-01-01

    . The second-order nonlinear water kinematics is developed based on a Gram Charlier series expansion using the first four stochasticmoments of thewave process. Thewave surface velocities and accelerations are expressed using a Taylor series expansion about themean sea level, which satisfies to the second...

  4. Averaging Principle for the Higher Order Nonlinear Schrödinger Equation with a Random Fast Oscillation

    Science.gov (United States)

    Gao, Peng

    2018-04-01

    This work concerns the problem associated with averaging principle for a higher order nonlinear Schrödinger equation perturbed by a oscillating term arising as the solution of a stochastic reaction-diffusion equation evolving with respect to the fast time. This model can be translated into a multiscale stochastic partial differential equations. Stochastic averaging principle is a powerful tool for studying qualitative analysis of stochastic dynamical systems with different time-scales. To be more precise, under suitable conditions, we prove that there is a limit process in which the fast varying process is averaged out and the limit process which takes the form of the higher order nonlinear Schrödinger equation is an average with respect to the stationary measure of the fast varying process. Finally, by using the Khasminskii technique we can obtain the rate of strong convergence for the slow component towards the solution of the averaged equation, and as a consequence, the system can be reduced to a single higher order nonlinear Schrödinger equation with a modified coefficient.

  5. Averaging Principle for the Higher Order Nonlinear Schrödinger Equation with a Random Fast Oscillation

    Science.gov (United States)

    Gao, Peng

    2018-06-01

    This work concerns the problem associated with averaging principle for a higher order nonlinear Schrödinger equation perturbed by a oscillating term arising as the solution of a stochastic reaction-diffusion equation evolving with respect to the fast time. This model can be translated into a multiscale stochastic partial differential equations. Stochastic averaging principle is a powerful tool for studying qualitative analysis of stochastic dynamical systems with different time-scales. To be more precise, under suitable conditions, we prove that there is a limit process in which the fast varying process is averaged out and the limit process which takes the form of the higher order nonlinear Schrödinger equation is an average with respect to the stationary measure of the fast varying process. Finally, by using the Khasminskii technique we can obtain the rate of strong convergence for the slow component towards the solution of the averaged equation, and as a consequence, the system can be reduced to a single higher order nonlinear Schrödinger equation with a modified coefficient.

  6. Treatment of Implant Exposure due to Skin Necroses after Skin Sparing Mastectomy: Initial Experiences Using a Not Selective Random Epigastric Flap.

    Science.gov (United States)

    Echazarreta-Gallego, Estíbaliz; Pola-Bandrés, Guillermo; Arribas-Del Amo, María Dolores; Gil-Romea, Ismael; Sousa-Domínguez, Ramón; Güemes-Sánchez, Antonio

    2017-10-01

    Breast prostheses exposure is probably the most devastating complication after a skin sparing mastectomy (SSM) and implant-based, one-stage, breast reconstruction. This complication may occur in the immediate post-operative period or in the weeks and even months after the procedure. In most cases, the cause is poor skin coverage of the implant due to skin necrosis. Eight consecutive cases of implant exposure (or risk of exposure) due to skin necrosis in SSM patients over a period of 5 years, all patients were treated using a random epigastric rotation flap, executed by the same medical team. A random epigastric flap (island or conventional rotation flap) was used to cover the skin defect. All the patients completed the procedure and all prostheses were saved; there were no cases of flap necrosis or infection. Cases of skin necrosis after SSM and immediate implant reconstruction, in which the implant is at risk of exposure, can be successfully treated with a random epigastric rotation flap.

  7. Differential effect of exposure-based therapy and cognitive therapy on post-traumatic stress disorder symptom clusters: A randomized controlled trial.

    Science.gov (United States)

    Horesh, Danny; Qian, Meng; Freedman, Sara; Shalev, Arieh

    2017-06-01

    A question remains regarding differential effects of exposure-based versus non-exposure-based therapies on specific post-traumatic stress disorder (PTSD) symptom clusters. Traumatized emergency room patients were randomized to receive prolonged exposure (PE) or cognitive therapy (CT) without exposure. PE/CT had no differential effect on individual symptom clusters, and change in total PTSD score remained significant even after controlling for the reductions in all three symptom clusters. In addition, baseline levels of PTSD avoidance/intrusion/hyperarousal did not moderate the effects of PE and CT on total PTSD symptom scores. Taken together, these findings challenge the notion that PE and CT are specifically, and differentially, useful in treating one particular PTSD symptom cluster. Despite their different theoretical backgrounds and techniques, the notion that PE and CT (without exposure) target different PTSD symptoms was not confirmed in this study. Thus, both interventions may in fact be equally effective for treating intrusion, avoidance and hyperarousal symptoms. Baseline levels of avoidance, intrusion and hyperarousal may not be good a priori indicators for PTSD treatment selection. The effect of PE and CT on PTSD as a whole does not seem to depend on a reduction in any specific symptom cluster. These findings indicate that exposure and non-exposure interventions may lead to similar results in terms of reductions in specific PTSD symptoms. It is quite possible that individual PTSD clusters may respond to therapy in an inter-related fashion, with one cluster affecting the other. © 2016 The British Psychological Society.

  8. Virtual reality cue exposure for the relapse prevention of tobacco consumption: a study protocol for a randomized controlled trial.

    Science.gov (United States)

    Giovancarli, Camille; Malbos, Eric; Baumstarck, Karine; Parola, Nathalie; Pélissier, Marie-Florence; Lançon, Christophe; Auquier, Pascal; Boyer, Laurent

    2016-02-19

    Successful interventions have been developed for smoking cessation, but the success of smoking relapse prevention interventions has been limited. In particular, cognitive behavioural therapy (CBT) has been hampered by a high relapse rate. Because relapses can be due to the presence of conditions associated with tobacco consumption (such as drinking in bars with friends), virtual reality exposure therapy (VRET) can generate synthetic environments that represent risk situations for the patient in the context of relapse prevention. The primary objective of this study is to evaluate the effectiveness of CBT coupled with VRET, in comparison to CBT alone, in the prevention of smoking relapse. The secondary objectives are to assess the impact of CBT coupled with VRET on anxiety, depression, quality of life, self-esteem and addictive comorbidities (such as alcohol, cannabis, and gambling). A third objective examines the feasibility and acceptability of VR use considering elements such as presence, cybersickness and number of patients who complete the VRET program. The present study is a 14-month (2 months of therapy followed by 12 months of follow-up), prospective, comparative, randomized and open clinical trial, involving two parallel groups (CBT coupled with VRET versus CBT alone). The primary outcome is the proportion of individuals with tobacco abstinence at 6 months after the end of the therapy. Abstinence is defined by the total absence of tobacco consumption assessed during a post-test interview and with an apparatus that measures the carbon monoxide levels expired. A total of 60 individuals per group will be included. This study is the first to examine the efficacy of CBT coupled with VRET in the prevention of smoking relapse. Because VRET is simple to use and has a low cost, this interactive therapeutic method might be easily implemented in clinical practice if the study confirms its efficacy. ClinicalTrials.gov Identifier: NCT02205060 (registered 25 July 2014).

  9. A randomized male tolerance study of dapivirine gel following multiple topical penile exposures (MTN 012/IPM 010).

    Science.gov (United States)

    Cranston, Ross D; Hoesley, Craig; Carballo-Diéguez, Alex; Hendrix, Craig W; Husnik, Marla; Levy, Lisa; Hall, Wayne; Soto-Torres, Lydia; Nel, Annalene M

    2014-02-01

    Dapivirine (DPV) is a nonnucleoside reverse transcriptase inhibitor with a favorable safety profile following vaginal application. A penile tolerance study was conducted prior to further development of DPV as a candidate vaginal microbicide. Twenty-four circumcised and 24 uncircumcised (N=48) healthy HIV-negative male participants aged 18 years or older were randomized 2:1:1 to apply DPV 0.05% gel, matched placebo gel, or universal placebo gel, respectively, to their penis once daily for 7 sequential days. The safety, acceptability, and pharmacokinetic profile of DPV 0.05% gel were assessed by the presence of Grade 2 or higher genitourinary adverse events (AEs) and systemic AEs, a behavioral questionnaire, and pharmacokinetic plasma blood draw, respectively, at the final clinic visit (FCV). There were no Grade 2 genitourinary AEs in 47 participants completing the FCV. One participant in the DPV arm failed to attend the FCV. There were 13 AEs reported; all were Grade 1 except one Grade 2 corneal laceration unrelated to study product. Participants liked the gel to a moderate extent, yet 72% reported they would be "very likely" to use a gel like the one they used in the study every time they have intercourse. DPV was detectable in plasma in all 23 DPV arm study participants at the FCV. On average, the circumcised participants' DPV concentrations were 54% of those in uncircumcised participants (p=0.07). Topical seven-day penile application of DPV 0.05% gel was locally and systemically safe, was acceptable to male participants, and resulted in systemic exposure to the drug.

  10. Sample size adjustments for varying cluster sizes in cluster randomized trials with binary outcomes analyzed with second-order PQL mixed logistic regression.

    Science.gov (United States)

    Candel, Math J J M; Van Breukelen, Gerard J P

    2010-06-30

    Adjustments of sample size formulas are given for varying cluster sizes in cluster randomized trials with a binary outcome when testing the treatment effect with mixed effects logistic regression using second-order penalized quasi-likelihood estimation (PQL). Starting from first-order marginal quasi-likelihood (MQL) estimation of the treatment effect, the asymptotic relative efficiency of unequal versus equal cluster sizes is derived. A Monte Carlo simulation study shows this asymptotic relative efficiency to be rather accurate for realistic sample sizes, when employing second-order PQL. An approximate, simpler formula is presented to estimate the efficiency loss due to varying cluster sizes when planning a trial. In many cases sampling 14 per cent more clusters is sufficient to repair the efficiency loss due to varying cluster sizes. Since current closed-form formulas for sample size calculation are based on first-order MQL, planning a trial also requires a conversion factor to obtain the variance of the second-order PQL estimator. In a second Monte Carlo study, this conversion factor turned out to be 1.25 at most. (c) 2010 John Wiley & Sons, Ltd.

  11. Effects of a randomized intervention promoting healthy children's meals on children's ordering and dietary intake in a quick-service restaurant.

    Science.gov (United States)

    Anzman-Frasca, Stephanie; Braun, Abbey C; Ehrenberg, Sarah; Epstein, Leonard H; Gampp, April; Leone, Lucia A; Singh, Anita; Tauriello, Sara

    2018-08-01

    Children's consumption of restaurant foods is associated with higher energy intake and lower nutritional quality compared to foods prepared at home. The aim of this pilot study was to test whether an in-restaurant intervention promoting healthy children's meals (i.e. two meals that met nutrition recommendations and were thus healthier than typical children's meal offerings across leading restaurants) affected children's meal selection and intake. Families with 4-to-8-year-old children were recruited from one location of Anderson's Frozen Custard, a regional quick-service restaurant chain. Families were randomly assigned to return to the restaurant during an intervention or control period and were blinded to group assignment. All families received free meals. During the intervention period families also received placemats featuring two healthy "Kids' Meals of the Day" upon restaurant entry. After families finished dining, researchers recorded children's orders and collected leftovers for quantifying dietary intake via weighed plate waste. Poisson regression and chi-square tests were used to compare children's orders between study groups, and t-tests were used to test for differences in dietary intake among children ordering a promoted healthy entrée (main dish) versus those who did not. Fifty-eight families participated. Children who were exposed to the study placemats prior to ordering ordered a significantly greater number of healthy food components compared to controls (p = 0.03). Overall, in the intervention group, 21% of children ordered a healthy entrée or side dish, versus 7% of controls. Children who ordered one of the promoted healthy entrées consumed less saturated fat across the total meal compared to those who did not (p = 0.04). Manipulating the prominence of healthy choices in restaurants may shift children's meal selections. Future research should build on these initial promising results, aiming to increase the potency of the intervention

  12. Infectious exposure in the first years of life and risk of central nervous system tumours in children: analysis of birth order, childcare attendance and seasonality of birth

    Science.gov (United States)

    Schmidt, L S; Kamper-Jørgensen, M; Schmiegelow, K; Johansen, C; Lähteenmäki, P; Träger, C; Stokland, T; Grell, K; Gustafson, G; Kogner, P; Sehested, A; Schüz, J

    2010-01-01

    Background: An infective, mostly viral basis has been found in different human cancers. To test the hypothesis of a possible infectious aetiology for central nervous system (CNS) tumours in children, we investigated the associations with proxy measures of exposure to infectious disease. Methods: In a large case–control study nested in the populations of Denmark, Norway, Sweden, and Finland of 4.4 million children, we studied the association of birth order and seasonal variation of birth with subsequent risk for CNS tumours. We identified 3983 children from the national cancer registries, and information on exposure was obtained from the high-quality national administrative health registries. We investigated the association between childcare attendance during the first 2 years of life and the risk for CNS tumours in a subset of Danish children with CNS tumours, using information from the Danish Childcare database. Results: We observed no association between birth order and risk of CNS tumours overall (odds ratio (OR) for second born or later born vs first born, 1.03; 95% confidence interval (CI), 0.96–1.10) or by histological subgroup, and children with CNS tumours did not show a seasonal variation of birth that was distinct from that of the background population. Childcare attendance compared with homecare showed a slightly increased OR (1.29; 95% CI, 0.90–1.86) for CNS tumours, with the highest risk observed in children attending a crèche. The strongest association was observed for embryonal CNS tumours. We found no effect of age at enrolment or duration of enrolment in childcare. Conclusion: These results do not support the hypothesis that the burden of exposure to infectious disease in early childhood has an important role in the aetiology of paediatric CNS tumours. PMID:20461079

  13. Infectious exposure in the first years of life and risk of central nervous system tumours in children: analysis of birth order, childcare attendance and seasonality of birth.

    Science.gov (United States)

    Schmidt, L S; Kamper-Jørgensen, M; Schmiegelow, K; Johansen, C; Lähteenmäki, P; Träger, C; Stokland, T; Grell, K; Gustafson, G; Kogner, P; Sehested, A; Schüz, J

    2010-05-25

    An infective, mostly viral basis has been found in different human cancers. To test the hypothesis of a possible infectious aetiology for central nervous system (CNS) tumours in children, we investigated the associations with proxy measures of exposure to infectious disease. In a large case-control study nested in the populations of Denmark, Norway, Sweden, and Finland of 4.4 million children, we studied the association of birth order and seasonal variation of birth with subsequent risk for CNS tumours. We identified 3983 children from the national cancer registries, and information on exposure was obtained from the high-quality national administrative health registries. We investigated the association between childcare attendance during the first 2 years of life and the risk for CNS tumours in a subset of Danish children with CNS tumours, using information from the Danish Childcare database. We observed no association between birth order and risk of CNS tumours overall (odds ratio (OR) for second born or later born vs first born, 1.03; 95% confidence interval (CI), 0.96-1.10) or by histological subgroup, and children with CNS tumours did not show a seasonal variation of birth that was distinct from that of the background population. Childcare attendance compared with homecare showed a slightly increased OR (1.29; 95% CI, 0.90-1.86) for CNS tumours, with the highest risk observed in children attending a crèche. The strongest association was observed for embryonal CNS tumours. We found no effect of age at enrolment or duration of enrolment in childcare. These results do not support the hypothesis that the burden of exposure to infectious disease in early childhood has an important role in the aetiology of paediatric CNS tumours.

  14. Impact of Exposure to Electronic Cigarette Advertising on Susceptibility and Trial of Electronic Cigarettes and Cigarettes in US Young Adults: A Randomized Controlled Trial.

    Science.gov (United States)

    Villanti, Andrea C; Rath, Jessica M; Williams, Valerie F; Pearson, Jennifer L; Richardson, Amanda; Abrams, David B; Niaura, Raymond S; Vallone, Donna M

    2016-05-01

    This study assessed the impact of brief exposure to four electronic cigarette (e-cigarette) print advertisements (ads) on perceptions, intention, and subsequent use of e-cigarettes and cigarettes in US young adults. A randomized controlled trial was conducted in a national sample of young adults from an online panel survey in 2013. Participants were randomized to ad exposure or control. Curiosity, intentions, and perceptions regarding e-cigarettes were assessed post-exposure and e-cigarette and cigarette use at 6-month follow-up. Analyses were conducted in 2014. Approximately 6% of young adults who had never used an e-cigarette at baseline tried an e-cigarette at 6-month follow-up, half of whom were current cigarette smokers at baseline. Compared to the control group, ad exposure was associated with greater curiosity to try an e-cigarette (18.3% exposed vs. 11.3% unexposed, AOR = 1.63, 95% CI = 1.18, 2.26) among never e-cigarette users and greater likelihood of e-cigarette trial at follow-up (3.6% exposed vs. 1.2% unexposed, AOR = 2.85; 95% CI = 1.07, 7.61) among never users of cigarettes and e-cigarettes. Exploratory analyses did not find an association between ad exposure and cigarette trial or past 30-day use among never users, nor cigarette use among smokers over time. Curiosity mediated the relationship between ad exposure and e-cigarette trial among e-cigarette never users. Exposure to e-cigarette ads may enhance curiosity and limited trial of e-cigarettes in never users. Future studies are needed to examine the net effect of curiosity and trial of e-cigarettes on longer-term patterns of tobacco use. This randomized trial provides the first evidence of the effect of e-cigarette advertising on a behavioral outcome in young adults. Compared to the control group, ad exposure was associated with greater curiosity to try an e-cigarette among never e-cigarette users and greater likelihood of e-cigarette trial at follow-up in a small number of never e

  15. Effect of calorie or exercise labels on menus on calories and macronutrients ordered and calories from specific foods in Hispanic participants: a randomized study.

    Science.gov (United States)

    Shah, Meena; Bouza, Brooke; Adams-Huet, Beverley; Jaffery, Manall; Esposito, Phil; Dart, Lyn

    2016-12-01

    The effect of menu labels on food choices is unknown in Hispanics. This study evaluated the impact of menu labels on calories and macronutrients ordered in Hispanics. 372 Hispanics (18-65 years) were randomly assigned to menus with no labels (NL) (n=127), rank-ordered calorie labels plus a statement on energy needs per meal (CL) (n=123), or rank-ordered exercise labels showing minutes of brisk walking necessary to burn the food calories (EL) (n=122). The menus had identical food choices. Participants were instructed to select foods from the assigned menu as if having lunch in a fast food restaurant. One-way analysis of variance found no difference in calories ordered (median (25th and 75th centiles)) by menu condition (NL: 785.0 (465.0, 1010.0) kcal; CL: 790.0 (510.0, 1020.0) kcal; EL: 752.5 (520.0, 1033.8) kcal; p=0.75). Calories from specific foods and macronutrient intake were not different by menu condition. Menu label use was 26.8% in the CL and 25.4% in the EL condition. Calories ordered were not different between those who used and those who did not use the labels. Regression analysis showed that perception of being overweight (p=0.02), selecting foods based on health value (p<0.0001), and meeting exercise guidelines (p<0.0001) were associated with fewer calories ordered. Logistic regression showed that selecting foods based on health value (p=0.01) was associated with higher food label use. Menu labels did not affect food choices in Hispanic participants. Future studies should determine if nutrition, exercise, and weight perception counseling prior to menu labels intervention would result in better food choices. NCT02804503; post-results. Copyright © 2016 American Federation for Medical Research.

  16. Efficacy of the RADPAD Protection Drape in Reducing Operators' Radiation Exposure in the Catheterization Laboratory: A Sham-Controlled Randomized Trial.

    Science.gov (United States)

    Vlastra, Wieneke; Delewi, Ronak; Sjauw, Krischan D; Beijk, Marcel A; Claessen, Bimmer E; Streekstra, Geert J; Bekker, Robbert J; van Hattum, Juliette C; Wykrzykowska, Joanna J; Vis, Marije M; Koch, Karel T; de Winter, Robbert J; Piek, Jan J; Henriques, José P S

    2017-11-01

    Interventional cardiologists are increasingly exposed to radiation-induced diseases like cataract and the stochastic risk of left-sided brain tumors. The RADPAD is a sterile, disposable, lead-free shield placed on the patient with the aim to minimize operator-received scatter radiation. The objective of the trial was to examine the RADPAD's efficacy in a real-world situation. In the current, double-blind, sham-controlled, all-comer trial, patients undergoing diagnostic catheterization or percutaneous coronary interventions were randomized in a 1:1:1 ratio to a radiation absorbing shield (RADPAD), standard treatment (NOPAD), or a sham shield (SHAMPAD). The sham shield allowed testing for shield-induced radiation behavior. The primary outcome was the difference in relative exposure of the primary operator between the RADPAD and NOPAD arms and was defined as the ratio between operator's exposure (E in µSv) and patient exposure (dose area product in mGy·cm 2 ), measured per procedure. A total of 766 consecutive coronary procedures were randomized to the use of RADPAD (N=255), NOPAD (N=255), or SHAMPAD (N=256). The use of RADPAD was associated with a 20% reduction in relative operator exposure compared with that of NOPAD ( P =0.01) and a 44% relative exposure reduction compared with the use of a SHAMPAD ( P RADPAD radiation shield reduced operator radiation exposure compared with procedures with NOPAD or SHAMPAD. This study supports the routine use of RADPAD in the catheterization laboratory. URL: https://www.clinicaltrials.gov. Unique identifier: NCT03139968. © 2017 American Heart Association, Inc.

  17. Influence of inhomogeneous static magnetic field-exposure on patients with erosive gastritis: a randomized, self- and placebo-controlled, double-blind, single centre, pilot study.

    Science.gov (United States)

    Juhász, Márk; Nagy, Viktor L; Székely, Hajnal; Kocsis, Dorottya; Tulassay, Zsolt; László, János F

    2014-09-06

    This pilot study was devoted to the effect of static magnetic field (SMF)-exposure on erosive gastritis. The randomized, self- and placebo-controlled, double-blind, pilot study included 16 patients of the 2nd Department of Internal Medicine, Semmelweis University diagnosed with erosive gastritis. The instrumental analysis followed a qualitative (pre-intervention) assessment of the symptoms by the patient: lower heartburn (in the ventricle), upper heartburn (in the oesophagus), epigastric pain, regurgitation, bloating and dry cough. Medical diagnosis included a double-line upper panendoscopy followed by 30 min local inhomogeneous SMF-exposure intervention at the lower sternal region over the stomach with peak-to-peak magnetic induction of 3 mT and 30 mT m(-1) gradient at the target site. A qualitative (post-intervention) assessment of the same symptoms closed the examination. Sham- or SMF-exposure was used in a double-blind manner. The authors succeeded in justifying the clinically and statistically significant beneficial effect of the SMF- over sham-exposure on the symptoms of erosive gastritis, the average effect of inhibition was 56% by p = 0.001, n = 42 + 96. This pilot study was aimed to encourage gastroenterologists to test local, inhomogeneous SMF-exposure on erosive gastritis patients, so this intervention may become an evidence-based alternative or complementary method in the clinical use especially in cases when conventional therapy options are contraindicated. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  18. Effects of Moxa (Folium Artemisiae argyi Smoke Exposure on Heart Rate and Heart Rate Variability in Healthy Young Adults: A Randomized, Controlled Human Study

    Directory of Open Access Journals (Sweden)

    Yingxue Cui

    2013-01-01

    Full Text Available Objective. To determine the effects of the moxa smoke on human heart rate (HR and heart rate variability (HRV. Methods. Fifty-five healthy young adults were randomly divided into experimental (n=28 and control (n=27 groups. Experimental subjects were exposed to moxa smoke (2.5 ± 0.5 mg/m3 twice for 25 minutes in one week. ECG monitoring was performed before, during, and after exposure. Control subjects were exposed to normal indoor air in a similar environment and similarly monitored. Followup was performed the following week. Short-term (5 min HRV parameters were analyzed with HRV analysis software. SPSS software was used for statistical analysis. Results. During and after the first exposure, comparison of percentage changes or changes in all parameters between groups showed no significant differences. During the second exposure, percentage decrease in HR, percentage increases in lnTP, lnHF, lnLF, and RMSSD, and increase in PNN50 were significantly greater in the experimental group than in control. Conclusion. No significant adverse HRV effects were associated with this clinically routine 25-minute exposure to moxa smoke, and the data suggests that short-term exposure to moxa smoke might have positive regulating effects on human autonomic function. Further studies are warranted to confirm these findings.

  19. The impact of multiple interventions to reduce household exposure to second-hand tobacco smoke among women: a cluster randomized controlled trial in Kalutara district, Sri Lanka

    Directory of Open Access Journals (Sweden)

    A. M. A. A. P. Alagiyawanna

    2017-10-01

    Full Text Available Abstract Background Second-hand smoke (SHS in households remains a serious public health problem in Sri Lanka, partly due to a lack of voluntary prohibitions of tobacco smoking inside houses. Women are especially at risk of being exposed. Effective community based interventions to reduce the SHS in households targeting women is scarce. The objective of this study was to examine the impact of a multi-component intervention on household SHS exposure among Sri Lankan women. Methods Thirty clusters of 25 women (aged 18–65 from 750 households were randomized into the intervention and control groups. Women in the intervention group were exposed to activities which focused on improving knowledge on the health effects of SHS, attitudes towards SHS exposure, right to a smoke-free living and women empowerment against smoking. The duration of the intervention was six months. The comparison group received no intervention. The primary outcome of interest was self-reported SHS exposure in the household within 7 days prior to data collection. The secondary outcomes were exposure in the past 30 days, knowledge of the health risks of exposure, attitudes towards exposure, right to smoke-free living, women empowerment against smoking, and smoking inside the homes. Results Final assessment was in 329 (89.6% in the intervention group and 309 (85.8% in the comparison group. Following the intervention, significantly lower proportion of women in the intervention group as compared to the control group reported SHS exposure in their households within 7-days (9.2% vs. 15.3%, p = 0.02 and 30-days (13.6% vs. 21.6%, p = 0.008 prior to the post survey. As compared to the control group, significantly higher median scores were observed in the intervention group on the knowledge of the health risks of exposure to SHS (p < 0.001, attitudes on exposure to SHS (p = 0.004, right to smoke free living (p = 0.001 and women empowerment (p < 0.001. Conclusion Multi

  20. 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.

  1. Axitinib dose titration: analyses of exposure, blood pressure and clinical response from a randomized phase II study in metastatic renal cell carcinoma.

    Science.gov (United States)

    Rini, B I; Melichar, B; Fishman, M N; Oya, M; Pithavala, Y K; Chen, Y; Bair, A H; Grünwald, V

    2015-07-01

    In a randomized, double-blind phase II trial in patients with metastatic renal cell carcinoma (mRCC), axitinib versus placebo titration yielded a significantly higher objective response rate. We evaluated pharmacokinetic and blood pressure (BP) data from this study to elucidate relationships among axitinib exposure, BP change, and efficacy. Patients received axitinib 5 mg twice daily during a lead-in period. Patients who met dose-titration criteria were randomized 1:1 to stepwise dose increases with axitinib or placebo. Patients ineligible for randomization continued without dose increases. Serial 6-h and sparse pharmacokinetic sampling were carried out; BP was measured at clinic visits and at home in all patients, and by 24-h ambulatory BP monitoring (ABPM) in a subset of patients. Area under the plasma concentration-time curve from 0 to 24 h throughout the course of treatment (AUCstudy) was higher in patients with complete or partial responses than those with stable or progressive disease in the axitinib-titration arm, but comparable between these groups in the placebo-titration and nonrandomized arms. In the overall population, AUCstudy and efficacy outcomes were not strongly correlated. Mean BP across the population was similar when measured in clinic, at home, or by 24-h ABPM. Weak correlations were observed between axitinib steady-state exposure and diastolic BP. When grouped by change in diastolic BP from baseline, patients in the ≥10 and ≥15 mmHg groups had longer progression-free survival. Optimal axitinib exposure may differ among patients with mRCC. Pharmacokinetic or BP measurements cannot be used exclusively to guide axitinib dosing. Individualization of treatment with vascular endothelial growth factor receptor tyrosine kinase inhibitors, including axitinib, is thus more complex than anticipated and cannot be limited to a single clinical factor. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical

  2. Energy Contents of Frequently Ordered Restaurant Meals and Comparison with Human Energy Requirements and US Department of Agriculture Database Information: A Multisite Randomized Study

    Science.gov (United States)

    Urban, Lorien E.; Weber, Judith L.; Heyman, Melvin B.; Schichtl, Rachel L.; Verstraete, Sofia; Lowery, Nina S.; Das, Sai Krupa; Schleicher, Molly M.; Rogers, Gail; Economos, Christina; Masters, William A.; Roberts, Susan B.

    2017-01-01

    Background Excess energy intake from meals consumed away from home is implicated as a major contributor to obesity, and ~50% of US restaurants are individual or small-chain (non–chain) establishments that do not provide nutrition information. Objective To measure the energy content of frequently ordered meals in non–chain restaurants in three US locations, and compare with the energy content of meals from large-chain restaurants, energy requirements, and food database information. Design A multisite random-sampling protocol was used to measure the energy contents of the most frequently ordered meals from the most popular cuisines in non–chain restaurants, together with equivalent meals from large-chain restaurants. Setting Meals were obtained from restaurants in San Francisco, CA; Boston, MA; and Little Rock, AR, between 2011 and 2014. Main outcome measures Meal energy content determined by bomb calorimetry. Statistical analysis performed Regional and cuisine differences were assessed using a mixed model with restaurant nested within region×cuisine as the random factor. Paired t tests were used to evaluate differences between non–chain and chain meals, human energy requirements, and food database values. Results Meals from non–chain restaurants contained 1,205±465 kcal/meal, amounts that were not significantly different from equivalent meals from large-chain restaurants (+5.1%; P=0.41). There was a significant effect of cuisine on non–chain meal energy, and three of the four most popular cuisines (American, Italian, and Chinese) had the highest mean energy (1,495 kcal/meal). Ninety-two percent of meals exceeded typical energy requirements for a single eating occasion. Conclusions Non–chain restaurants lacking nutrition information serve amounts of energy that are typically far in excess of human energy requirements for single eating occasions, and are equivalent to amounts served by the large-chain restaurants that have previously been criticized

  3. Energy Contents of Frequently Ordered Restaurant Meals and Comparison with Human Energy Requirements and U.S. Department of Agriculture Database Information: A Multisite Randomized Study.

    Science.gov (United States)

    Urban, Lorien E; Weber, Judith L; Heyman, Melvin B; Schichtl, Rachel L; Verstraete, Sofia; Lowery, Nina S; Das, Sai Krupa; Schleicher, Molly M; Rogers, Gail; Economos, Christina; Masters, William A; Roberts, Susan B

    2016-04-01

    Excess energy intake from meals consumed away from home is implicated as a major contributor to obesity, and ∼50% of US restaurants are individual or small-chain (non-chain) establishments that do not provide nutrition information. To measure the energy content of frequently ordered meals in non-chain restaurants in three US locations, and compare with the energy content of meals from large-chain restaurants, energy requirements, and food database information. A multisite random-sampling protocol was used to measure the energy contents of the most frequently ordered meals from the most popular cuisines in non-chain restaurants, together with equivalent meals from large-chain restaurants. Meals were obtained from restaurants in San Francisco, CA; Boston, MA; and Little Rock, AR, between 2011 and 2014. Meal energy content determined by bomb calorimetry. Regional and cuisine differences were assessed using a mixed model with restaurant nested within region×cuisine as the random factor. Paired t tests were used to evaluate differences between non-chain and chain meals, human energy requirements, and food database values. Meals from non-chain restaurants contained 1,205±465 kcal/meal, amounts that were not significantly different from equivalent meals from large-chain restaurants (+5.1%; P=0.41). There was a significant effect of cuisine on non-chain meal energy, and three of the four most popular cuisines (American, Italian, and Chinese) had the highest mean energy (1,495 kcal/meal). Ninety-two percent of meals exceeded typical energy requirements for a single eating occasion. Non-chain restaurants lacking nutrition information serve amounts of energy that are typically far in excess of human energy requirements for single eating occasions, and are equivalent to amounts served by the large-chain restaurants that have previously been criticized for providing excess energy. Restaurants in general, rather than specific categories of restaurant, expose patrons to

  4. Effects of smartphone diaries and personal dosimeters on behavior in a randomized study of methods to document sunlight exposure

    DEFF Research Database (Denmark)

    Køster, Brian; Søndergaard, Jens; Nielsen, Jesper Bo

    2016-01-01

    study. We examined the effects of wearing dosimeters and filling out diaries, measurement period and recall effect on the sun-related behavior in Denmark in 2012.Our sample included 240 participants eligible by smartphone status and who took a vacation during weeks 26-32 in 2012, randomized by gender...

  5. A Randomized Male Tolerance Study of Dapivirine Gel Following Multiple Topical Penile Exposures (MTN 012/IPM 010)

    OpenAIRE

    Cranston, Ross D.; Hoesley, Craig; Carballo-Diéguez, Alex; Hendrix, Craig W.; Husnik, Marla; Levy, Lisa; Hall, Wayne; Soto-Torres, Lydia; Nel, Annalene M.

    2014-01-01

    Dapivirine (DPV) is a nonnucleoside reverse transcriptase inhibitor with a favorable safety profile following vaginal application. A penile tolerance study was conducted prior to further development of DPV as a candidate vaginal microbicide. Twenty-four circumcised and 24 uncircumcised (N=48) healthy HIV-negative male participants aged 18 years or older were randomized 2:1:1 to apply DPV 0.05% gel, matched placebo gel, or universal placebo gel, respectively, to their penis once daily for 7 se...

  6. Adverse respiratory effect of acute β-blocker exposure in asthma: a systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Morales, Daniel R; Jackson, Cathy; Lipworth, Brian J; Donnan, Peter T; Guthrie, Bruce

    2014-04-01

    β-Blockers are avoided in asthma over concerns regarding acute bronchoconstriction. Risk is greatest following acute exposure, including the potential for antagonism of β2-agonist rescue therapy. A systematic review of databases was performed to identify all randomized, blinded, placebo-controlled clinical trials evaluating acute β-blocker exposure in asthma. Effect estimates for changes in respiratory function, symptoms, and β2-agonist response were pooled using random effects meta-analysis with heterogeneity investigated. Acute selective β-blockers in the doses given caused a mean change in FEV1 of −6.9% (95% CI, −8.5 to −5.2), a fall in FEV1 of ≥20% in one in eight patients (P=.03), symptoms affecting one in 33 patients (P=.18), and attenuation of concomitant β2-agonist response of −10.2% (95% CI, −14.0 to −6.4). Corresponding values for acute nonselective β-blockers in the doses given were −10.2% (95% CI, −14.7 to −5.6), one in nine patients (P=.02), one in 13 patients (P=.14), and −20.0% (95% CI, −29.4 to −10.7). Following investigation of heterogeneity, clear differences were found for celiprolol and labetalol. A dose-response relationship was demonstrated for selective β-blockers. Selective β-blockers are better tolerated but not completely risk-free. Risk from acute exposure may be mitigated using the smallest dose possible and β-blockers with greater β1-selectivity. β-Blocker-induced bronchospasm responded partially to β2-agonists in the doses given with response blunted more by nonselective β-blockers than selective β-blockers. Use of β-blockers in asthma could possibly be based upon a risk assessment on an individual patient basis.

  7. Does short-term exposure to mobile phone base station signals increase symptoms in individuals who report sensitivity to electromagnetic fields? A double-blind randomized provocation study.

    Science.gov (United States)

    Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Mirshekar-Syahkal, Dariush; Rasor, Paul; Deeble, Roger; Fox, Elaine

    2007-11-01

    Individuals with idiopathic environmental illness with attribution to electromagnetic fields (IEI-EMF) believe they suffer negative health effects when exposed to electromagnetic fields from everyday objects such as mobile phone base stations. This study used both open provocation and double-blind tests to determine if sensitive and control individuals experience more negative health effects when exposed to base station-like signals compared with sham. Fifty-six self-reported sensitive and 120 control participants were tested in an open provocation test. Of these, 12 sensitive and 6 controls withdrew after the first session. The remainder completed a series of double-blind tests. Subjective measures of well-being and symptoms as well as physiological measures of blood volume pulse, heart rate, and skin conductance were obtained. During the open provocation, sensitive individuals reported lower levels of well-being in both the global system for mobile communication (GSM) and universal mobile telecommunications system (UMTS) compared with sham exposure, whereas controls reported more symptoms during the UMTS exposure. During double-blind tests the GSM signal did not have any effect on either group. Sensitive participants did report elevated levels of arousal during the UMTS condition, whereas the number or severity of symptoms experienced did not increase. Physiological measures did not differ across the three exposure conditions for either group. Short-term exposure to a typical GSM base station-like signal did not affect well-being or physiological functions in sensitive or control individuals. Sensitive individuals reported elevated levels of arousal when exposed to a UMTS signal. Further analysis, however, indicated that this difference was likely to be due to the effect of order of exposure rather than the exposure itself.

  8. Laser confers less embryo exposure than acid tyrode for embryo biopsy in preimplantation genetic diagnosis cycles: a randomized study.

    Science.gov (United States)

    Geber, Selmo; Bossi, Renata; Lisboa, Cintia B; Valle, Marcelo; Sampaio, Marcos

    2011-04-28

    We compared two methods of zona pellucida drilling. 213 embryos were biopsied with acid Tyrode. Each biopsy took 3 minutes and the entire procedure ~29 minutes. 5% of blastomeres lysed, 49% of embryos became blastocyst and 36% of patients became pregnant. 229 embryos were biopsied with laser. Each biopsy took 30 seconds and the entire procedure ~7 minutes. 2.5% of blastomeres lysed, 50.6% of embryos became blastocyst and 47% of patients became pregnant. We can conclude that laser can be used for embryo biopsy. Reduction of embryo exposure and of removed blastomeres is associated with increased blastocysts available for transfer and a better clinical outcome.

  9. Laser confers less embryo exposure than acid tyrode for embryo biopsy in preimplantation genetic diagnosis cycles: a randomized study

    Directory of Open Access Journals (Sweden)

    Valle Marcelo

    2011-04-01

    Full Text Available Abstract We compared two methods of zona pellucida drilling. 213 embryos were biopsied with acid Tyrode. Each biopsy took 3 minutes and the entire procedure ~29 minutes. 5% of blastomeres lysed, 49% of embryos became blastocyst and 36% of patients became pregnant. 229 embryos were biopsied with laser. Each biopsy took 30 seconds and the entire procedure ~7 minutes. 2.5% of blastomeres lysed, 50.6% of embryos became blastocyst and 47% of patients became pregnant. We can conclude that laser can be used for embryo biopsy. Reduction of embryo exposure and of removed blastomeres is associated with increased blastocysts available for transfer and a better clinical outcome.

  10. Higher order optical aberrations and visual acuity in a randomized controlled trial comparing transepithelial versus epithelium-off corneal crosslinking for progressive keratoconus

    Directory of Open Access Journals (Sweden)

    Godefrooij DA

    2017-10-01

    Full Text Available Daniel A Godefrooij, Mustapha El Kandoussi, Nienke Soeters, Robert PL Wisse Utrecht Cornea Research Group, Department of Ophthalmology, University Medical Center Utrecht, Utrecht, the Netherlands Purpose: The purpose of this study was to compare the effects of transepithelial crosslinking (trans-CXL versus epithelium-off crosslinking (epi-off CXL for progressive keratoconus with respect to the development of higher order aberrations (HOAs and their effects on visual acuity.Materials and methods: A total of 61 patients were randomized and examined preoperatively and 1, 3, 6, and 12 months postoperatively in an academic referral center. Total corneal HOAs were compared between the two treatment groups using mixed linear modeling. Types of HOAs (coma, trefoil, and spherical aberration that differed between groups were entered in a multivariable analysis to test their effect on uncorrected distance visual acuity (UDVA and corrected distance visual acuity (CDVA.Results: The epi-off CXL group had more flattening in maximal keratometry compared to the trans-CXL group (P=0.02. UDVA did not differ significantly between the groups (P=0.59; however, CDVA was significantly more improved in the trans-CXL group (P=0.02. Horizontal trefoil improved more in the epi-off group compared to the trans-CXL group (P=0.04, whereas the other HOAs were virtually unchanged in both groups. Differences in changes in HOAs between the two groups had no effect on either UCVA (P=0.76 or CDVA (P=0.96.Conclusion: Although HOAs are clinically relevant determinants of vision quality in keratoconus patients, the change in total HOAs post treatment did not differ between the trans-CXL and epi-off CXL groups. Only horizontal trefoil differed significantly post treatment between the trans-CXL and epi-off CXL groups. However, this difference did not independently affect either UDVA or CDVA. Trans-CXL provides no benefit over epi-off CXL regarding visual relevant HOAs. Keywords

  11. Pre-exposure prophylaxis for the prevention of HIV infection in high risk populations: a meta-analysis of randomized controlled trials.

    Directory of Open Access Journals (Sweden)

    Junjun Jiang

    Full Text Available Nearly ten randomized controlled trials (RCTs of pre-exposure prophylaxis (PrEP have been completed or are ongoing worldwide to evaluate the effectiveness of PrEP in HIV transmission among HIV-uninfected high risk populations. The purpose of this study was to evaluate the role of PrEP to prevent HIV transmission through a Mata-analysis.A comprehensive computerized literature search was carried out in PubMed, EMbase, Ovid, Web of Science, Science Direct, Wan Fang, CNKI and related websites to collect relevant articles (from their establishment date to August 30, 2013. The search terms were "pre-exposure prophylaxis", "high risk population", "HIV infection", "reduction", "relative risk" and "efficacy". We included any RCT assessing PrEP for the prevention of HIV infection in high risk populations. Interventions of the studies were continuously daily or intermittent doses of single or compound antiretrovirals (ARVs before HIV exposure or during HIV exposure. A meta-analysis was conducted using Stata 10.0. A random-effects method was used to calculate the pooled relative risk (RR and 95% confidence intervals (CI for all studies included.Seven RCTs involving 14,804 individuals in high risk populations were eligible for this study. The number of subjects in the experimental groups was 8,195, with HIV infection rate of 2.03%. The number of subjects in the control groups was 6,609, with HIV infection rate of 4.07%. The pooled RR was 0.53 (95% CI = 0.40 ∼ 0.71, P<0.001. The re-analyzed pooled RR were 0.61 (95% CI = 0.48 ∼ 0.77, P<0.001, 0.49 (95% CI = 0.38 ∼ 0.63, P<0.001, respectively, by excluding the largest study or two studies without statistical significance. Publication bias analysis revealed a symmetry funnel plot. The fail-safe number was 1,022.These results show that PrEP is an effective strategy for reducing new HIV infections in high risk populations.

  12. Constitution of a group of Czech and French uranium miners in order to estimate lung cancer risk linked to low chronic exposure to radon decay products

    International Nuclear Information System (INIS)

    Tirmarche, M.; Tomasek, L.

    1996-01-01

    West Bohemian and French uranium miners are characterized by a long duration of exposure to radon and its decay products, in comparison to most of the other groups of miners, studied in the recent international joint analysis by the National Cancer Institute (NCI) in USA. This analysis has confirmed the linearly increasing risk of lung cancer by cumulative radon exposure, describing the different factors that may influence this dose-response relationship. One of the main factors presently discussed is the influence of the exposure-rate effect: in other words, has the same cumulated exposure spread over 10 years the same risk of lung cancer as if it is cumulated in 2 years? The implication of an inverse exposure-rate effect for low chronic exposures as well as some methodological approaches will be discussed and tested by using the data of the Czech and French cohorts. These two cohorts present annual exposures varying by a factor of 5 to 10, French exposure rates being close or even less than 0.1 Working Level during the last 20 years. The project is integrated in a larger European project on uranium miners, co-ordinated by IPSN. (author)

  13. Ultrasound simulator-assisted teaching of cardiac anatomy to preclinical anatomy students: A pilot randomized trial of a three-hour learning exposure.

    Science.gov (United States)

    Canty, David Jeffrey; Hayes, Jenny A; Story, David Andrew; Royse, Colin Forbes

    2015-01-01

    Ultrasound simulation allows students to virtually explore internal anatomy by producing accurate, moving, color, three-dimensional rendered slices from any angle or approach leaving the organs and their relationships intact without requirement for consumables. The aim was to determine the feasibility and efficacy of self-directed learning of cardiac anatomy with an ultrasound simulator compared to cadavers and plastic models. After a single cardiac anatomy lecture, fifty university anatomy students participated in a three-hour supervised self-directed learning exposure in groups of five, randomized to an ultrasound simulator or human cadaveric specimens and plastic models. Pre- and post-tests were conducted using pictorial and non-pictorial multiple-choice questions (MCQs). Simulator students completed a survey on their experience. Four simulator and seven cadaver group students did not attend after randomization. Simulator use in groups of five students was feasible and feedback from participants was very positive. Baseline test scores were similar (P = 0.9) between groups. After the learning intervention, there was no difference between groups in change in total test score (P = 0.37), whether they were pictorial (P = 0.6) or non-pictorial (P = 0.21). In both groups there was an increase in total test scores (simulator +19.8 ±12.4%% and cadaver: +16.4% ± 10.2, P human cadaveric prosections for learning cardiac anatomy. © 2014 American Association of Anatomists.

  14. Kids Safe and Smokefree (KiSS): a randomized controlled trial of a multilevel intervention to reduce secondhand tobacco smoke exposure in children.

    Science.gov (United States)

    Lepore, Stephen J; Winickoff, Jonathan P; Moughan, Beth; Bryant-Stephens, Tyra C; Taylor, Daniel R; Fleece, David; Davey, Adam; Nair, Uma S; Godfrey, Melissa; Collins, Bradley N

    2013-08-30

    Secondhand smoke exposure (SHSe) harms children's health, yet effective interventions to reduce child SHSe in the home and car have proven difficult to operationalize in pediatric practice. A multilevel intervention combining pediatric healthcare providers' advice with behavioral counseling and navigation to pharmacological cessation aids may improve SHSe control in pediatric populations. This trial uses a randomized, two-group design with three measurement periods: pre-intervention, end of treatment and 12-month follow-up. Smoking parents of children parents about child SHSe, advise about SHSe harms, and refer smokers to cessation resources. After receiving clinic intervention, eligible parents are randomized to receive: (a) a 3-month telephone-based behavioral counseling intervention designed to promote reduction in child SHSe, parent smoking cessation, and navigation to access nicotine replacement therapy or cessation medication or (b) an attention control nutrition education intervention. Healthcare providers and assessors are blind to group assignment. Cotinine is used to bioverify child SHSe (primary outcome) and parent quit status. This study tests an innovative multilevel approach to reducing child SHSe. The approach is sustainable, because clinics can easily integrate the tobacco intervention prompts related to "ask, advise, and refer" guidelines into electronic health records and refer smokers to free evidence-based behavioral counseling interventions, such as state quitlines. NCT01745393 (clinicaltrials.gov).

  15. A randomized, double-blind evaluation of D-cycloserine or alprazolam combined with virtual reality exposure therapy for posttraumatic stress disorder in Iraq and Afghanistan War veterans.

    Science.gov (United States)

    Rothbaum, Barbara Olasov; Price, Matthew; Jovanovic, Tanja; Norrholm, Seth D; Gerardi, Maryrose; Dunlop, Boadie; Davis, Michael; Bradley, Bekh; Duncan, Erica J; Rizzo, Albert; Ressler, Kerry J

    2014-06-01

    The authors examined the effectiveness of virtual reality exposure augmented with D-cycloserine or alprazolam, compared with placebo, in reducing posttraumatic stress disorder (PTSD) due to military trauma. After an introductory session, five sessions of virtual reality exposure were augmented with D-cycloserine (50 mg) or alprazolam (0.25 mg) in a double-blind, placebo-controlled randomized clinical trial for 156 Iraq and Afghanistan war veterans with PTSD. PTSD symptoms significantly improved from pre- to posttreatment across all conditions and were maintained at 3, 6, and 12 months. There were no overall differences in symptoms between D-cycloserine and placebo at any time. Alprazolam and placebo differed significantly on the Clinician-Administered PTSD Scale score at posttreatment and PTSD diagnosis at 3 months posttreatment; the alprazolam group showed a higher rate of PTSD (82.8%) than the placebo group (47.8%). Between-session extinction learning was a treatment-specific enhancer of outcome for the D-cycloserine group only. At posttreatment, the D-cycloserine group had the lowest cortisol reactivity and smallest startle response during virtual reality scenes. A six-session virtual reality treatment was associated with reduction in PTSD diagnoses and symptoms in Iraq and Afghanistan veterans, although there was no control condition for the virtual reality exposure. There was no advantage of D-cycloserine for PTSD symptoms in primary analyses. In secondary analyses, alprazolam impaired recovery and D-cycloserine enhanced virtual reality outcome in patients who demonstrated within-session learning. D-cycloserine augmentation reduced cortisol and startle reactivity more than did alprazolam or placebo, findings that are consistent with those in the animal literature.

  16. Effect of leucine supplementation on fat free mass with prolonged hypoxic exposure during a 13-day trek to Everest Base Camp: a double-blind randomized study.

    Science.gov (United States)

    Wing-Gaia, Stacie L; Gershenoff, Dana C; Drummond, Micah J; Askew, E Wayne

    2014-03-01

    Loss of body weight and fat-free mass (FFM) are commonly noted with prolonged exposure to hypobaric hypoxia. Recent evidence suggests protein supplementation, specifically leucine, may potentially attenuate loss of FFM in subcaloric conditions during normoxia. The purpose of this study was to determine if leucine supplementation would prevent the loss of FFM in subcaloric conditions during prolonged hypoxia. Eighteen physically active male (n = 10) and female (n = 8) trekkers completed a 13-day trek in Nepal to Everest Base Camp with a mean altitude of 4140 m (range 2810-5364 m). In this double-blind study, participants were randomized to ingest either leucine (LEU) (7 g leucine, 93 kcal, 14.5 g whey-based protein) or an isocaloric isonitrogenous control (CON) (0.3 g LEU, 93 kcal, 11.3 g collagen protein) twice daily prior to meals. Body weight, body composition, and circumferences of bicep, thigh, and calf were measured pre- and post-trek. There was a significant time effect for body weight (-2.2% ± 1.7%), FFM (-1.7% ± 1.5%), fat mass (-4.0% ± 6.9%), and circumferences (p FFM (CON -2.1 ± 1.5%; LEU -1.2 ± 1.6%), fat mass (CON -2.9% ± 5.9%; LEU -5.4% ± 8.1%), or circumferences. Although a significant loss of body weight, FFM, and fat mass was noted in 13 days of high altitude exposure, FFM loss was not attenuated by leucine. Future studies are needed to determine if leucine attenuates loss of FFM with longer duration high altitude exposure.

  17. Analysis of high-altitude de-acclimatization syndrome after exposure to high altitudes: a cluster-randomized controlled trial.

    Science.gov (United States)

    He, Binfeng; Wang, Jianchun; Qian, Guisheng; Hu, Mingdong; Qu, Xinming; Wei, Zhenghua; Li, Jin; Chen, Yan; Chen, Huaping; Zhou, Qiquan; Wang, Guansong

    2013-01-01

    The syndrome of high-altitude de-acclimatization commonly takes place after long-term exposure to high altitudes upon return to low altitudes. The syndrome severely affects the returnee's quality of life. However, little attention has been paid to careful characterization of the syndrome and their underlying mechanisms. Male subjects from Chongqing (n = 67, 180 m) and Kunming (n = 70, 1800 m) visited a high-altitude area (3650 m) about 6 months and then returned to low-altitude. After they came back, all subjects were evaluated for high-altitude de-acclimatization syndrome on the 3(rd), 50(th), and 100(th). Symptom scores, routine blood and blood gas tests, and myocardial zymograms assay were used for observation their syndrome. The results showed that the incidence and severity of symptoms had decreased markedly on the 50(th) and 100(th) days, compared with the 3(rd) day. The symptom scores and incidence of different symptoms were lower among subjects returning to Kunming than among those returning to Chongqing. On the 3(rd) day, RBC, Hb, Hct, CK, CK-MB, and LDH values were significantly lower than values recorded at high altitudes, but they were higher than baseline values. On the 50(th) day, these values were not different from baseline values, but LDH levels did not return to baseline until the 100(th) day. These data show that, subjects who suffered high-altitude de-acclimatization syndrome, the recovery fully processes takes a long time (≥ 100(th) days). The appearance of the syndrome is found to be related to the changes in RBC, Hb, Hct, CK, CK-MB, and LDH levels, which should be caused by reoxygenation after hypoxia.

  18. Effects of a liquefied petroleum gas stove intervention on pollutant exposure and adult cardiopulmonary outcomes (CHAP): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Fandiño-Del-Rio, Magdalena; Goodman, Dina; Kephart, Josiah L; Miele, Catherine H; Williams, Kendra N; Moazzami, Mitra; Fung, Elizabeth C; Koehler, Kirsten; Davila-Roman, Victor G; Lee, Kathryn A; Nangia, Saachi; Harvey, Steven A; Steenland, Kyle; Gonzales, Gustavo F; Checkley, William

    2017-11-03

    Biomass fuel smoke is a leading risk factor for the burden of disease worldwide. International campaigns are promoting the widespread adoption of liquefied petroleum gas (LPG) in resource-limited settings. However, it is unclear if the introduction and use of LPG stoves, in settings where biomass fuels are used daily, reduces pollution concentration exposure, improves health outcomes, or how cultural and social barriers influence the exclusive adoption of LPG stoves. We will conduct a randomized controlled, field intervention trial of LPG stoves and fuel distribution in rural Puno, Peru, in which we will enroll 180 female participants aged 25-64 years and follow them for 2 years. After enrollment, we will collect information on sociodemographic characteristics, household characteristics, and cooking practices. During the first year of the study, LPG stoves and fuel tanks will be delivered to the homes of 90 intervention participants. During the second year, participants in the intervention arm will keep their LPG stoves, but the gas supply will stop. Control participants will receive LPG stoves and vouchers to obtain free fuel from distributors at the beginning of the second year, but gas will not be delivered. Starting at baseline, we will collect longitudinal measurements of respiratory symptoms, pulmonary function, blood pressure, endothelial function, carotid artery intima-media thickness, 24-h dietary recalls, exhaled carbon monoxide, quality-of-life indicators, and stove-use behaviors. Environmental exposure assessments will occur six times over the 2-year follow-up period, consisting of 48-h personal exposure and kitchen concentration measurements of fine particulate matter and carbon monoxide, and 48-h kitchen concentrations of nitrogen dioxide for a subset of 100 participants. Findings from this study will allow us to better understand behavioral patterns, environmental exposures, and cardiovascular and pulmonary outcomes resulting from the adoption of

  19. Neutron scattering study of unstable magnetic long-range order in the random two-dimensional Ising antiferromagnets Rb/sub 2/Cosub(c)Mgsub(1-c)F/sub 4/

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, H; Suzuki, M [Ochanomizu Univ., Tokyo (Japan). Dept. of Physics; Hutchings, M T [UKAEA Atomic Energy Research Establishment, Harwell. Materials Physics Div.

    1979-01-01

    The spin correlation between two-dimensionally (2D) ordered antiferromagnetic layers in the random antiferromagnets Rb/sub 2/Cosub(c)Mgsub(1-c)F/sub 4/ depends strongly on the rate at which the sample is cooled through the Neel point Tsub(N) and decreases markedly with decreasing Co/sup 2 +/ ion concentration c. Preliminary data are presented which indicate that the order below sub(N) is metastable and relaxes to a fully correlated 3D ordered state on a finite, measurable, time-scale.

  20. Much of the variation in breast pathology quality assurance data in the UK can be explained by the random order in which cases arrive at individual centres, but some true outliers do exist.

    Science.gov (United States)

    Cross, Simon S; Stephenson, Timothy J; Harrison, Robert F

    2011-10-01

    To investigate the role of random temporal order of patient arrival at screening centres in the variability seen in rates of node positivity and breast cancer grade between centres in the NHS Breast Screening Programme. Computer simulations were performed of the variation in node positivity and breast cancer grade with the random temporal arrival of patients at screening centres based on national UK audit data. Cumulative mean graphs of these data were plotted. Confidence intervals for the parameters were generated, using the binomial distribution. UK audit data were plotted on these control limit graphs. The results showed that much of the variability in the audit data could be accounted for by the effects of random order of arrival of cases at the screening centres. Confidence intervals of 99.7% identified true outliers in the data. Much of the variation in breast pathology quality assurance data in the UK can be explained by the random order in which cases arrive at individual centres. Control charts with confidence intervals of 99.7% plotted against the number of reported cases are useful tools for identification of true outliers. 2011 Blackwell Publishing Limited.

  1. Random-field effects on the order in the diluted weakly anisotropic antiferromagnet K2NixZn1-xF4

    DEFF Research Database (Denmark)

    Dikken, B. J.; Arts, A. F. M.; Wijn, H. W. de

    1984-01-01

    With the use of neutron diffraction, the effects of random fields are studied in the diluted quadratic-layer antiferromagnet K2NixZn1-xF4 for x=0.96, 0.85, and 0.75. Upon cooling in external fields as small as H∼0.1 T, the systems quench into a nonequilibrium domain state characterized...

  2. Effect of Prolonged Exposure Therapy Delivered Over 2 Weeks vs 8 Weeks vs Present-Centered Therapy on PTSD Symptom Severity in Military Personnel: A Randomized Clinical Trial.

    Science.gov (United States)

    Foa, Edna B; McLean, Carmen P; Zang, Yinyin; Rosenfield, David; Yadin, Elna; Yarvis, Jeffrey S; Mintz, Jim; Young-McCaughan, Stacey; Borah, Elisa V; Dondanville, Katherine A; Fina, Brooke A; Hall-Clark, Brittany N; Lichner, Tracey; Litz, Brett T; Roache, John; Wright, Edward C; Peterson, Alan L

    2018-01-23

    Effective and efficient treatment is needed for posttraumatic stress disorder (PTSD) in active duty military personnel. To examine the effects of massed prolonged exposure therapy (massed therapy), spaced prolonged exposure therapy (spaced therapy), present-centered therapy (PCT), and a minimal-contact control (MCC) on PTSD severity. Randomized clinical trial conducted at Fort Hood, Texas, from January 2011 through July 2016 and enrolling 370 military personnel with PTSD who had returned from Iraq, Afghanistan, or both. Final follow-up was July 11, 2016. Prolonged exposure therapy, cognitive behavioral therapy involving exposure to trauma memories/reminders, administered as massed therapy (n = 110; 10 sessions over 2 weeks) or spaced therapy (n = 109; 10 sessions over 8 weeks); PCT, a non-trauma-focused therapy involving identifying/discussing daily stressors (n = 107; 10 sessions over 8 weeks); or MCC, telephone calls from therapists (n = 40; once weekly for 4 weeks). Outcomes were assessed before and after treatment and at 2-week, 12-week, and 6-month follow-up. Primary outcome was interviewer-assessed PTSD symptom severity, measured by the PTSD Symptom Scale-Interview (PSS-I; range, 0-51; higher scores indicate greater PTSD severity; MCID, 3.18), used to assess efficacy of massed therapy at 2 weeks posttreatment vs MCC at week 4; noninferiority of massed therapy vs spaced therapy at 2 weeks and 12 weeks posttreatment (noninferiority margin, 50% [2.3 points on PSS-I, with 1-sided α = .05]); and efficacy of spaced therapy vs PCT at posttreatment. Among 370 randomized participants, data were analyzed for 366 (mean age, 32.7 [SD, 7.3] years; 44 women [12.0%]; mean baseline PSS-I score, 25.49 [6.36]), and 216 (59.0%) completed the study. At 2 weeks posttreatment, mean PSS-I score was 17.62 (mean decrease from baseline, 7.13) for massed therapy and 21.41 (mean decrease, 3.43) for MCC (difference in decrease, 3.70 [95% CI,0.72 to 6.68]; P = .02

  3. Development of a Virtual Reality Exposure Tool as Psychological Preparation for Elective Pediatric Day Care Surgery: Methodological Approach for a Randomized Controlled Trial.

    Science.gov (United States)

    Eijlers, Robin; Legerstee, Jeroen S; Dierckx, Bram; Staals, Lonneke M; Berghmans, Johan; van der Schroeff, Marc P; Wijnen, Rene Mh; Utens, Elisabeth Mwj

    2017-09-11

    Preoperative anxiety in children is highly prevalent and is associated with adverse outcomes. Existing psychosocial interventions to reduce preoperative anxiety are often aimed at distraction and are of limited efficacy. Gradual exposure is a far more effective way to reduce anxiety. Virtual reality (VR) provides a unique opportunity to gradually expose children to all aspects of the operating theater. The aims of our study are (1) to develop a virtual reality exposure (VRE) tool to prepare children psychologically for surgery; and (2) to examine the efficacy of the VRE tool in a randomized controlled trial (RCT), in which VRE will be compared to care as usual (CAU). The VRE tool is highly realistic and resembles the operating room environment accurately. With this tool, children will not only be able to explore the operating room environment, but also get accustomed to general anesthesia procedures. The PREoperative Virtual reality Intervention to Enhance Wellbeing (PREVIEW) study will be conducted. In this single-blinded RCT, 200 consecutive patients (aged 4 to 12 years) undergoing elective day care surgery for dental, oral, or ear-nose-throat problems, will be randomly allocated to the preoperative VRE intervention or CAU. The primary outcome is change in child state anxiety level between baseline and induction of anesthesia. Secondary outcome measures include child's postoperative anxiety, emergence delirium, postoperative pain, use of analgesics, health care use, and pre- and postoperative parental anxiety. The VRE tool has been developed. Participant recruitment began March 2017 and is expected to be completed by September 2018. To our knowledge, this is the first RCT evaluating the effect of a VRE tool to prepare children for surgery. The VRE intervention is expected to significantly diminish preoperative anxiety, postoperative pain, and the use of postoperative analgesics in pediatric patients. The tool could create a less stressful experience for both

  4. Development of a Virtual Reality Exposure Tool as Psychological Preparation for Elective Pediatric Day Care Surgery: Methodological Approach for a Randomized Controlled Trial

    Science.gov (United States)

    Eijlers, Robin; Legerstee, Jeroen S; Dierckx, Bram; Staals, Lonneke M; Berghmans, Johan; van der Schroeff, Marc P; Wijnen, Rene MH

    2017-01-01

    Background Preoperative anxiety in children is highly prevalent and is associated with adverse outcomes. Existing psychosocial interventions to reduce preoperative anxiety are often aimed at distraction and are of limited efficacy. Gradual exposure is a far more effective way to reduce anxiety. Virtual reality (VR) provides a unique opportunity to gradually expose children to all aspects of the operating theater. Objective The aims of our study are (1) to develop a virtual reality exposure (VRE) tool to prepare children psychologically for surgery; and (2) to examine the efficacy of the VRE tool in a randomized controlled trial (RCT), in which VRE will be compared to care as usual (CAU). Methods The VRE tool is highly realistic and resembles the operating room environment accurately. With this tool, children will not only be able to explore the operating room environment, but also get accustomed to general anesthesia procedures. The PREoperative Virtual reality Intervention to Enhance Wellbeing (PREVIEW) study will be conducted. In this single-blinded RCT, 200 consecutive patients (aged 4 to 12 years) undergoing elective day care surgery for dental, oral, or ear-nose-throat problems, will be randomly allocated to the preoperative VRE intervention or CAU. The primary outcome is change in child state anxiety level between baseline and induction of anesthesia. Secondary outcome measures include child’s postoperative anxiety, emergence delirium, postoperative pain, use of analgesics, health care use, and pre- and postoperative parental anxiety. Results The VRE tool has been developed. Participant recruitment began March 2017 and is expected to be completed by September 2018. Conclusions To our knowledge, this is the first RCT evaluating the effect of a VRE tool to prepare children for surgery. The VRE intervention is expected to significantly diminish preoperative anxiety, postoperative pain, and the use of postoperative analgesics in pediatric patients. The tool

  5. Effect of virtual reality exposure therapy on social participation in people with a psychotic disorder (VRETp): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Pot-Kolder, Roos; Veling, Wim; Geraets, Chris; van der Gaag, Mark

    2016-01-13

    Many patients with a psychotic disorder participate poorly in society. When psychotic disorders are in partial remission, feelings of paranoia, delusions of reference, social anxiety and self-stigmatization often remain at diminished severity and may lead to avoidance of places and people. Virtual reality exposure therapy (VRET) is an evidence-based treatment for several anxiety disorders. For patients with a psychotic disorder, the VRETp was developed to help them experience exposure to feared social situations. The present study aims to investigate the effects of VRETp on social participation in real life among patients with a psychotic disorder. The study is a single-blind randomized controlled trial with two conditions: the active condition, in which participants receive the virtual reality treatment together with treatment as usual (TAU), and the waiting list condition, in which participants receive TAU only. The two groups are compared at baseline, at 3 months posttreatment and at 6 months follow-up. All participants on the waiting list are also offered the virtual reality treatment after the follow-up measurements are completed. The primary outcome is social participation. Secondary outcomes are quality of life, interaction anxiety, depression and social functioning in general. Moderator and mediator analyses are conducted with stigma, cognitive schemata, cognitive biases, medication adherence, simulator sickness and presence in virtual reality. If effective, a cost-effectiveness analysis will be conducted. Results from the posttreatment measurement can be considered strong empirical indicators of the effectiveness of VRETp. The 6-month follow-up data may provide reliable documentation of the long-term effects of the treatment on the outcome variables. Data from pre-treatment and mid-treatment can be used to reveal possible pathways of change. Current Controlled Trials: ISRCTN12929657 . Date of registration: 8 September 2015.

  6. Improved cortisol exposure-time profile and outcome in patients with adrenal insufficiency: a prospective randomized trial of a novel hydrocortisone dual-release formulation.

    Science.gov (United States)

    Johannsson, G; Nilsson, A G; Bergthorsdottir, R; Burman, P; Dahlqvist, P; Ekman, B; Engström, B E; Olsson, T; Ragnarsson, O; Ryberg, M; Wahlberg, J; Biller, B M K; Monson, J P; Stewart, P M; Lennernäs, H; Skrtic, S

    2012-02-01

    Patients with treated adrenal insufficiency (AI) have increased morbidity and mortality rate. Our goal was to improve outcome by developing a once-daily (OD) oral hydrocortisone dual-release tablet with a more physiological exposure-time cortisol profile. The aim was to compare pharmacokinetics and metabolic outcome between OD and the same daily dose of thrice-daily (TID) dose of conventional hydrocortisone tablets. We conducted an open, randomized, two-period, 12-wk crossover multicenter trial with a 24-wk extension at five university hospital centers. The trial enrolled 64 adults with primary AI; 11 had concomitant diabetes mellitus (DM). The same daily dose of hydrocortisone was administered as OD dual-release or TID. We evaluated cortisol pharmacokinetics. Compared with conventional TID, OD provided a sustained serum cortisol profile 0-4 h after the morning intake and reduced the late afternoon and the 24-h cortisol exposure. The mean weight (difference = -0.7 kg, P = 0.005), systolic blood pressure (difference = -5.5 mm Hg, P = 0.0001) and diastolic blood pressure (difference: -2.3 mm Hg; P = 0.03), and glycated hemoglobin (absolute difference = -0.1%, P = 0.0006) were all reduced after OD compared with TID at 12 wk. Compared with TID, a reduction in glycated hemoglobin by 0.6% was observed in patients with concomitant DM during OD (P = 0.004). The OD dual-release tablet provided a more circadian-based serum cortisol profile. Reduced body weight, reduced blood pressure, and improved glucose metabolism were observed during OD treatment. In particular, glucose metabolism improved in patients with concomitant DM.

  7. Infectious exposure in the first years of life and risk of central nervous system tumours in children: analysis of birth order, childcare attendance and seasonality of birth

    DEFF Research Database (Denmark)

    Schmidt, L S; Kamper-Jørgensen, M; Schmiegelow, K

    2010-01-01

    An infective, mostly viral basis has been found in different human cancers. To test the hypothesis of a possible infectious aetiology for central nervous system (CNS) tumours in children, we investigated the associations with proxy measures of exposure to infectious disease....

  8. Attitudes of women in their forties toward the 2009 USPSTF mammogram guidelines: a randomized trial on the effects of media exposure.

    Science.gov (United States)

    Davidson, AuTumn S; Liao, Xun; Magee, B Dale

    2011-07-01

    The objective of the study was to assess women's attitudes toward 2009 US Preventive Services Task Force mammography screening guideline changes and evaluate the role of media in shaping opinions. Two hundred forty-nine women, aged 39-49 years, presenting for annual examinations randomized to read 1 of 2 articles, and survey completion comprised the design of the study. Eighty-eight percent overestimated the lifetime breast cancer (BrCa) risk. Eighty-nine percent want yearly mammograms in their 40s. Eighty-six percent felt the changes were unsafe, and even if the changes were doctor recommended, 84% would not delay screening until age 50 years. Those with a friend/relative with BrCa were more likely to want annual mammography in their forties (92% vs 77%, P = .001), and feel changes unsafe (91% vs 69%, P ≤ .0001). Participants with previous false-positive mammograms were less likely to accept doctor-recommended screening delay until age 50 years (8% vs 21%, P = .01). Women overestimate BrCa risk. Skepticism of new mammogram guidelines exists, and is increased by exposure to negative media. Those with prior false-positive mammograms are less likely to accept changes. Copyright © 2011 Mosby, Inc. All rights reserved.

  9. A Randomized Controlled Clinical Trial of Dialogical Exposure Therapy versus Cognitive Processing Therapy for Adult Outpatients Suffering from PTSD after Type I Trauma in Adulthood.

    Science.gov (United States)

    Butollo, Willi; Karl, Regina; König, Julia; Rosner, Rita

    2016-01-01

    Although there are effective treatments for posttraumatic stress disorder (PTSD), there is little research on treatments with non-cognitive-behavioural backgrounds, such as gestalt therapy. We tested an integrative gestalt-derived intervention, dialogical exposure therapy (DET), against an established cognitive-behavioural treatment (cognitive processing therapy, CPT) for possible differential effects in terms of symptomatic outcome and drop-out rates. We randomized 141 treatment-seeking individuals with a diagnosis of PTSD to receive either DET or CPT. Therapy length in both treatments was flexible with a maximum duration of 24 sessions. Dropout rates were 12.2% in DET and 14.9% in CPT. Patients in both conditions achieved significant and large reductions in PTSD symptoms (Impact of Event Scale - Revised; Hedges' g = 1.14 for DET and d = 1.57 for CPT) which were largely stable at the 6-month follow-up. At the posttreatment assessment, CPT performed statistically better than DET on symptom and cognition measures. For several outcome measures, younger patients profited better from CPT than older ones, while there was no age effect for DET. Our results indicate that DET merits further research and may be an alternative to established treatments for PTSD. It remains to be seen whether DET confers advantages in areas of functioning beyond PTSD symptoms. © 2015 S. Karger AG, Basel.

  10. Babies Living Safe & Smokefree: randomized controlled trial of a multilevel multimodal behavioral intervention to reduce low-income children’s tobacco smoke exposure

    Directory of Open Access Journals (Sweden)

    Bradley N. Collins

    2017-03-01

    Full Text Available Abstract Background Addressing children’s tobacco smoke exposure (TSE remains a public health priority. However, there is low uptake and ineffectiveness of treatment, particularly in low-income populations that face numerous challenges to smoking behavior change. A multilevel intervention combining system-level health messaging and advice about TSE delivered at community clinics that disseminate the Special Supplemental Nutrition Program for Women, Infants and Children (WIC, combined with nicotine replacement and intensive multimodal, individual-level behavioral intervention may improve TSE control efforts in such high-risk populations. Methods/Design This trial uses a randomized two-group design with three measurement points: baseline, 3-month and 12-month follow-up. The primary outcome is bioverified child TSE; the secondary outcome is bioverified maternal quit status. Smoking mothers of children less than 6 years old are recruited from WIC clinics. All participants receive WIC system-level intervention based on the “Ask, Advise, Refer (AAR” best practices guidelines for pediatrics clinics. It includes training all WIC staff about the importance of maternal tobacco control; and detailing clinics with AAR intervention prompts in routine work flow to remind WIC nutrition counselors to ask all mothers about child TSE, advise about TSE harms and benefits of protection, and refer smokers to cessation services. After receiving the system intervention, mothers are randomized to receive 3 months of additional treatment or an attention control intervention: (1 The multimodal behavioral intervention (MBI treatment includes telephone counseling sessions about child TSE reduction and smoking cessation, provision of nicotine replacement therapy, a mobile app to support cessation efforts, and multimedia text messages about TSE and smoking cessation; (2 The attention control intervention offers equivalent contact as the MBI and includes nutrition

  11. An MGF-based unified framework to determine the joint statistics of partial sums of ordered i.n.d. random variables

    KAUST Repository

    Nam, Sungsik; Yang, Hongchuan; Alouini, Mohamed-Slim; Kim, Dongin

    2014-01-01

    framework to determine the joint statistics of partial sums of ordered i.n.d. RVs. Our mathematical formalism is illustrated with an application on the exact performance analysis of the capture probability of generalized selection combining (GSC)-based RAKE

  12. Efficacy of two different house screening interventions against exposure to malaria and anaemia in children in The Gambia: a randomized controlled trial

    Science.gov (United States)

    Kirby, Matthew J; Ameh, David; Green, Clare; Jawara, Musa; Milligan, Paul J; Bottomley, Christian; Snell, Paul C; Conway, David J; Lindsay, Steve W

    2013-01-01

    Summary Background House screening should protect people against malaria. We assessed whether two types of house screening, full screening of windows, doors and closing eaves or installing netting ceilings in local houses, could reduce malaria vector house entry and anaemia in children, in an area of seasonal transmission. Methods 500 occupied houses in and near Farafenni town in The Gambia were randomly assigned to receive full screening, screened ceilings, or no screening, in an area where coverage of insecticide-treated nets was low. Screening was not treated with insecticide. Exposure to mosquitoes indoors was assessed by fortnightly light trap collections, and haemoglobin (Hb) concentration and the prevalence of anaemia and parasitaemia measured in children, aged 6 months to 10 years old, at the end of the transmission season. Findings The mean number of Anopheles gambiae sensu lato mosquitoes, the principal malaria vector, was reduced by 59% in houses with full screening (95% CI 46, 69; pceilings (95% CI 30, 60; pceilings, adjusted OR 0.51, (0.27, 0.96; p=0.04). Mean Hb concentration was higher in children living in fully screened houses and in houses with screened ceilings (104g/L in both groups), than those in unscreened houses (100g/L); adjusted estimates of the differences 3.7g/L (0.3, 7.2; p=0.03) and 4.2g/L (0.6, 7.7; p=0.02) respectively. There was no evidence of an effect on the prevalence of malaria infection. Interpretation House screening substantially reduced the number of mosquitoes inside houses and can contribute to prevention of anaemia in children. Funding Medical Research Council PMID:19732949

  13. Mindfulness-based relapse prevention combined with virtual reality cue exposure for methamphetamine addiction: Study protocol for a randomized controlled trial.

    Science.gov (United States)

    Chen, XiJing; Wang, Dongmei; Zhou, Lidan; Winkler, Markus; Pauli, Paul; Sui, Nan; Li, Yonghui

    2018-04-18

    Mindfulness-based relapse prevention (MBRP) is a method that combines cognitive behavioral relapse prevention with mindfulness practice. Research shows that MBRP can effectively reduce negative emotions and craving in people with substance use disorders (SUDs). An important part of MBRP is to practice mindfulness meditation to cope with high-risk situations for relapse, such as stimuli and situations associated with drug taking. Virtual reality cue exposure (VRCE) may be a complementary approach to MBRP as it allows for controlled and graded presentations of various high-risk situations with distal and proximal drug cues. The aim of the study is to investigate the effects of MBRP combined with VRCE, in comparison to MBRP alone or treatment as usual, on craving and emotional responses in people with methamphetamine use disorders. The study is a parallel randomized controlled study including 180 participants with methamphetamine use disorders. Three parallel groups will receive 8 weeks of MBRP combined with VRCE, MBRP alone, or treatment as usual, respectively. Craving, virtual cue reactivity, anxiety, depression, emotion regulation, mindfulness and drug-related attention bias will be assessed at pre-treatment, post-treatment, and 3 and 6 months of follow-up. This innovative study aims at investigating the effects of MBRP combined with VRCE in people with SUDs. The combined intervention may have important clinical implications for relapse prevention due to its ease of application and high cost-effectiveness. This study may also stimulate research on the neuronal and psychological mechanisms of MBRP in drug addiction. ChiCTR-INR-17013041. Copyright © 2018. Published by Elsevier Inc.

  14. Effects of patient-directed music intervention on anxiety and sedative exposure in critically ill patients receiving mechanical ventilatory support: a randomized clinical trial.

    Science.gov (United States)

    Chlan, Linda L; Weinert, Craig R; Heiderscheit, Annie; Tracy, Mary Fran; Skaar, Debra J; Guttormson, Jill L; Savik, Kay

    2013-06-12

    Alternatives to sedative medications, such as music, may alleviate the anxiety associated with ventilatory support. To test whether listening to self-initiated patient-directed music (PDM) can reduce anxiety and sedative exposure during ventilatory support in critically ill patients. Randomized clinical trial that enrolled 373 patients from 12 intensive care units (ICUs) at 5 hospitals in the Minneapolis-St Paul, Minnesota, area receiving acute mechanical ventilatory support for respiratory failure between September 2006 and March 2011. Of the patients included in the study, 86% were white, 52% were female, and the mean (SD) age was 59 (14) years. The patients had a mean (SD) Acute Physiology, Age and Chronic Health Evaluation III score of 63 (21.6) and a mean (SD) of 5.7 (6.4) study days. Self-initiated PDM (n = 126) with preferred selections tailored by a music therapist whenever desired while receiving ventilatory support, self-initiated use of noise-canceling headphones (NCH; n = 122), or usual care (n = 125). Daily assessments of anxiety (on 100-mm visual analog scale) and 2 aggregate measures of sedative exposure (intensity and frequency). Patients in the PDM group listened to music for a mean (SD) of 79.8 (126) (median [range], 12 [0-796]) minutes/day. Patients in the NCH group wore the noise-abating headphones for a mean (SD) of 34.0 (89.6) (median [range], 0 [0-916]) minutes/day. The mixed-models analysis showed that at any time point, patients in the PDM group had an anxiety score that was 19.5 points lower (95% CI, -32.2 to -6.8) than patients in the usual care group (P = .003). By the fifth study day, anxiety was reduced by 36.5% in PDM patients. The treatment × time interaction showed that PDM significantly reduced both measures of sedative exposure. Compared with usual care, the PDM group had reduced sedation intensity by -0.18 (95% CI, -0.36 to -0.004) points/day (P = .05) and had reduced frequency by -0.21 (95% CI, -0.37 to -0.05) points/day (P

  15. Random Fields

    Science.gov (United States)

    Vanmarcke, Erik

    1983-03-01

    Random variation over space and time is one of the few attributes that might safely be predicted as characterizing almost any given complex system. Random fields or "distributed disorder systems" confront astronomers, physicists, geologists, meteorologists, biologists, and other natural scientists. They appear in the artifacts developed by electrical, mechanical, civil, and other engineers. They even underlie the processes of social and economic change. The purpose of this book is to bring together existing and new methodologies of random field theory and indicate how they can be applied to these diverse areas where a "deterministic treatment is inefficient and conventional statistics insufficient." Many new results and methods are included. After outlining the extent and characteristics of the random field approach, the book reviews the classical theory of multidimensional random processes and introduces basic probability concepts and methods in the random field context. It next gives a concise amount of the second-order analysis of homogeneous random fields, in both the space-time domain and the wave number-frequency domain. This is followed by a chapter on spectral moments and related measures of disorder and on level excursions and extremes of Gaussian and related random fields. After developing a new framework of analysis based on local averages of one-, two-, and n-dimensional processes, the book concludes with a chapter discussing ramifications in the important areas of estimation, prediction, and control. The mathematical prerequisite has been held to basic college-level calculus.

  16. The Effect of Solvent, Hydrogen Peroxide and Dioxide Titanium on Degradation of PCBs, Using Microwave Radiation in Order to Reduce Occupational Exposure

    Directory of Open Access Journals (Sweden)

    Tajik Reza

    2014-07-01

    Full Text Available Polychlorinated biphenyls (PCBs are one group of persistent organic pollutants (POPs that are of international concern because of global distribution, persistence, and toxicity. Removal of these compounds from the environment remains a very difficult challenge because the compounds are highly hydrophobic and have very low solubility in water. A 900 W domestic microwave oven, pyrex vessel reactor, pyrex tube connector and condensing system were used in this experiment. Radiation was discontinuous and ray powers were 540, 720 and 900 W. The PCBS were analyzed by GC-ECD. The application of microwave radiation and H2O2/TiO2 agents for the degradation of polychlorinated biphenyl contaminated oil was explored in this study. PCB – contaminated oil was treated in a pyrex reactor by microwave irradiation at 2450 MHz with the addition of H2O2/TiO2. A novel grain TiO2 (GT01 was used. The determination of PCB residues in oil by gas chromatography (GC revealed that rates of PCB decomposition were highly dependent on microwave power, exposure time, ratio to solvent with transformer oil in 3:1, the optimal amount of GT01 (0.2 g and 0.116 mol of H2O2 were used in the study. It was suggested that microwave irradiation with the assistance of H2O2/TiO2 might be a potential technology for the degradation of PCB – contaminated oil. The experiments show that MW irradiation, H2O2 oxidant and TiO2 catalyst lead to a degradation efficiency of PCBs only in the presence of ethanol. The results showed that the addition of ethanol significantly enhanced degradation efficiency of PCBs.

  17. In a randomized trial, the live attenuated tetravalent dengue vaccine TV003 is well-tolerated and highly immunogenic in subjects with flavivirus exposure prior to vaccination.

    Directory of Open Access Journals (Sweden)

    Stephen S Whitehead

    2017-05-01

    Full Text Available Infection caused by the four serotypes of dengue virus (DENV-1-4 is a leading cause of mosquito-borne disease. Clinically-severe dengue disease is more common when secondary dengue infection occurs following prior infection with a heterologous dengue serotype. Other flaviviruses such as yellow fever virus, Japanese encephalitis virus, and Zika virus, can also elicit antibodies which are cross-reactive to DENV. As candidate dengue vaccines become available in endemic settings and for individuals who have received other flavivirus vaccines, it is important to examine vaccine safety and immunogenicity in these flavivirus-experienced populations. We performed a randomized, controlled trial of the National Institutes of Health live attenuated tetravalent dengue vaccine candidate (TV003 in fifty-eight individuals with prior exposure to flavivirus infection or vaccine. As in prior studies of this vaccine in flavivirus-naive volunteers, flavivirus-experienced subjects received two doses of vaccine six months apart and were followed closely for clinical events, laboratory changes, viremia, and neutralizing antibody titers. TV003 was well tolerated with few adverse events other than rash, which was predominately mild. Following one dose, 87% of vaccinees had an antibody response to all four serotypes (tetravalent response, suggesting a robust immune response. In addition, 76% of vaccinees were viremic; mean peak titers ranged from 0.68–1.1 log10 PFU/mL and did not differ by serotype. The second dose of TV003 was not associated with viremia, rash, or a sustained boost in antibody titers indicating that a single dose of the vaccine is likely sufficient to prevent viral replication and thus protect against disease. In comparison to the viremia and neutralizing antibody response elicited by TV003 in flavivirus-naïve subjects from prior studies, we found that subjects who were flavivirus-exposed prior to vaccination exhibited slightly higher DENV-3 viremia

  18. Random magnetism

    International Nuclear Information System (INIS)

    Tsallis, C.

    1980-03-01

    The 'ingredients' which control a phase transition in well defined system as well as in random ones (e.g. random magnetic systems) are listed and discussed within a somehow unifying perspective. Among these 'ingredients' we find the couplings and elements responsible for the cooperative phenomenon, the topological connectivity as well as possible topological incompatibilities, the influence of new degrees of freedom, the order parameter dimensionality, the ground state degeneracy and finally the 'quanticity' of the system. The general trends, though illustrated in magnetic systems, essentially hold for all phase transitions, and give a basis for connection of this area with Field theory, Theory of dynamical systems, etc. (Author) [pt

  19. Random magnetism

    International Nuclear Information System (INIS)

    Tsallis, C.

    1981-01-01

    The 'ingredients' which control a phase transition in well defined systems as well as in random ones (e.q. random magnetic systems) are listed and discussed within a somehow unifying perspective. Among these 'ingredients' the couplings and elements responsible for the cooperative phenomenon, the topological connectivity as well as possible topological incompatibilities, the influence of new degrees of freedom, the order parameter dimensionality, the ground state degeneracy and finally the 'quanticity' of the system are found. The general trends, though illustrated in magnetic systems, essentially hold for all phase transitions, and give a basis for connection of this area with Field theory, Theory of dynamical systems, etc. (Author) [pt

  20. Random networking : between order and chaos

    NARCIS (Netherlands)

    Hofstad, van der R.W.

    2007-01-01

    With the arrival of the Internet, a good understanding of networks has become important for everyone. Network theory, which originated in the eighteenth century with Euler, and in the nineteenth century withMarkov, has until recently concentrated its attentionmainly on regular types of graphs. In

  1. Ordered Consumer Search

    OpenAIRE

    Armstrong, Mark

    2016-01-01

    The paper discusses situations in which consumers search through their options in a deliberate order, in contrast to more familiar models with random search. Topics include: network effects (consumers may be better off following the same search order as other consumers); the use of price and non-price advertising to direct search; the impact of consumers starting a new search with their previous supplier; the incentive sellers have to merge or co-locate with other sellers; and the incentive a...

  2. Internet-Based Self-Help with Therapist Feedback and in Vivo Group Exposure for Social Phobia: A Randomized Controlled Trial

    Science.gov (United States)

    Andersson, Gerhard; Carlbring, Per; Holmstrom, Annelie; Sparthan, Elisabeth; Furmark, Tomas; Nilsson-Ihrfelt, Elisabeth; Buhrman, Monica; Ekselius, Lisa

    2006-01-01

    Sixty-four individuals with social phobia (social anxiety disorder) were assigned to a multimodal cognitive-behavioral treatment package or to a waiting list control group. Treatment consisted of a 9-week, Internet-delivered, self-help program that was combined with 2 group exposure sessions in real life and minimal therapist contact via e-mail.…

  3. Development of a virtual reality exposure tool as psychological preparation for elective pediatric day care surgery: Methodological approach for a randomized controlled trial

    NARCIS (Netherlands)

    Eijlers, R.; Legerstee, J.S.; Dierckx, B.; Staals, L.M.; Berghmans, J.; van der Schroeff, M.P.; Wijnen, R.M.H.; Utens, E.M.W.J.

    Background Preoperative anxiety in children is highly prevalent and is associated with adverse outcomes. Existing psychosocial interventions to reduce preoperative anxiety are often aimed at distraction and are of limited efficacy. Gradual exposure is a far more effective way to reduce anxiety.

  4. Development of a Virtual Reality Exposure Tool as Psychological Preparation for Elective Pediatric Day Care Surgery: Methodological Approach for a Randomized Controlled Trial

    NARCIS (Netherlands)

    Eijlers, Robin; Legerstee, Jeroen S.; Dierckx, Bram; Staals, Lonneke M.; Berghmans, Johan; van der Schroeff, Marc P.; Wijnen, Rene M. H.; Utens, Elisabeth M. W. J.

    2017-01-01

    Preoperative anxiety in children is highly prevalent and is associated with adverse outcomes. Existing psychosocial interventions to reduce preoperative anxiety are often aimed at distraction and are of limited efficacy. Gradual exposure is a far more effective way to reduce anxiety. Virtual reality

  5. Partially ordered models

    NARCIS (Netherlands)

    Fernandez, R.; Deveaux, V.

    2010-01-01

    We provide a formal definition and study the basic properties of partially ordered chains (POC). These systems were proposed to model textures in image processing and to represent independence relations between random variables in statistics (in the later case they are known as Bayesian networks).

  6. Research on random service system efficiency of sorted storage manual order picking manners%分类存储人工拣选随机服务系统效率研究

    Institute of Scientific and Technical Information of China (English)

    朱杰; 周丽; 郭键

    2012-01-01

    The manual order picking system with order arrival as Poisson flow, and single picking servicer can be considered as M/G/l random service system. This paper studies the efficiency optimization problem of manual order picking system. We also analyze the stochastic characteristics of arrived orders goods categories and items number. The paper establishes picker route stochastic models under sorted storage return-type and S-type picking for logistics distribution center to deduce corresponding picking time distribution functions. Experiment results show that the two models approximate all approach simulation better under permitted error conditions. Compare the two picking manners with five kinds of goods order frequency and storage assignment, and then get application situations. This paper provides reference for estimation picking time and waiting time of traditional rectangular logistic distribution center, and provides basis for choosing storage strategy.%可以把订单服从泊松输入、单个拣选人员提供服务的人工拣选作业系统看作M/G/1随机服务系统,研究此随机服务系统的效率优化问题.分析订单到达的物品种类与件数随机特性,建立分类存储返回型与S型拣选距离随机模型,分别推导相应的拣选时间分布.仿真结果表明,两个模型的结果能在误差允许条件下较好地与仿真逼近.比较5种物品订购频率和货位分配情况下的返回型和S型拣选方式,得出两种拣选方式各自适用的情况.研究结论可以为传统矩形配送中心的订单拣选时间、等待时间估计提供参考,可为拣选路径方式选择提供依据.

  7. Exposure-Response Relationship for Ombitasvir and Paritaprevir/Ritonavir in Hepatitis C Virus Subgenotype 1b-Infected Japanese Patients in the Phase 3 Randomized GIFT-I Study.

    Science.gov (United States)

    Gopalakrishnan, Sathej; Khatri, Amit; Mensing, Sven; Redman, Rebecca; Menon, Rajeev; Zha, Jiuhong

    2016-04-01

    The all-oral 2 direct-acting antiviral (DAA) regimen of ombitasvir/paritaprevir/ritonavir 25/150/100 mg once a day has been evaluated in hepatitis C virus subgenotype 1b-infected Japanese adults in the GIFT-I study. The aim of this analysis was to evaluate potential relationships between DAA exposures and laboratory abnormalities/adverse events of peripheral edema in patients in GIFT-I. The GIFT-I study consisted of a randomized, double-blind, placebo-controlled substudy in patients without cirrhosis and an open-label substudy in patients with compensated cirrhosis. Patients received ombitasvir/paritaprevir/ritonavir for 12 weeks. Exposure-response relationships between individual components of the ombitasvir/paritaprevir/ritonavir regimen and clinical parameters of interest were explored using pharmacokinetic and clinical data from patients in the study. Graphical analyses were performed. For events that occurred in at least 10 patients (total bilirubin elevation ≥grade 2 and peripheral edema ≥grade 1), multivariate logistic regression analyses were used to identify significant relationships between predictor variables (drug exposures) and response variables (probability of adverse events or laboratory abnormalities), with consideration for the effect of potential covariates and baseline status of response variables. Data from 321 noncirrhotic and 42 compensated cirrhotic patients were analyzed. There were 14 events of peripheral edema (10 at grade 1 and 4 at grade 2) in patients who received concomitant administration of calcium channel blockers and ombitasvir/paritaprevir/ritonavir. There was no apparent relationship between the incidences of peripheral edema and exposures of paritaprevir, ombitasvir, or ritonavir. There was a shallow relationship between total bilirubin elevation and exposures of paritaprevir which is an inhibitor of bilirubin transporter organic anion-transporting polypeptide 1B. Based on graphical analyses, exposures of paritaprevir

  8. Effects of reducing exposure to air pollution on submaximal cardiopulmonary test in patients with heart failure: Analysis of the randomized, double-blind and controlled FILTER-HF trial.

    Science.gov (United States)

    Vieira, Jefferson L; Guimaraes, Guilherme V; de Andre, Paulo A; Saldiva, Paulo H Nascimento; Bocchi, Edimar A

    2016-07-15

    Air pollution exposure could mitigate the health benefits of exercise in patients with heart failure (HF). We tested the effects of a respiratory filter on HF patients exposed to air pollution during exercise. Ancillary analysis of the FILTER-HF trial, focused on the exercise outcomes. In a randomized, double-blind, 3-way crossover design, 26 HF patients and 15 control volunteers were exposed to clean air, unfiltered dilute diesel engine exhaust (DE), or filtered DE for 6min during a submaximal cardiopulmonary testing in a controlled-exposure facility. Prospectively collected data included six-minute walking test [6mwt], VO2, VE/VCO2 Slope, O2Pulse, pulmonary ventilation [VE], tidal volume, VD/Vt, oxyhemoglobin saturation and CO2-rebreathing. Compared to clean air, DE adversely affected VO2 (11.0±3.9 vs. 8.4±2.8ml/kg/min; preduced the particulate concentration from 325±31 to 25±6μg/m(3), and was associated with an increase in VO2 (10.4±3.8ml/kg/min; preduce the adverse effects of pollution on VO2 and O2Pulse. Given the worldwide prevalence of exposure to traffic-related air pollution, these findings are relevant for public health especially in this highly susceptible population. The filter intervention holds great promise that needs to be tested in future studies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  9. Investigation of Resonance Effect Caused by Local Exposure of Extremely Low Frequency Magnetic Field on Brain Signals: A Randomize Clinical Trial

    Directory of Open Access Journals (Sweden)

    Rasul Zadeh Tabataba’ei K

    2011-03-01

    Full Text Available Background and Objectives: Some studies have investigated the effects of extremely low frequency magnetic fields (ELF-MFs on brain signals, but only few of them have reported that humans exposed to magnetic fields exhibit changes in brain signals at the frequency of stimulation, i.e. resonance effect. In most investigations, researchers usually take advantage of a uniform field which encompasses the head. The aim of present study was to expose different parts of the brain to ELF-MFs locally and to investigate variation of brain signal and resonance effect.Methods: The subjects consisting of 19 male-students with the mean age of 25.6±1.6 years participated in this study. Local ELF-MFs with 3, 5, 10, 17 and 45Hz frequencies and 240 μT intensity was applied on five points (T3, T4, Cz, F3 and F4 of participants scalp Separately in 10-20 system. In the end, relative power over this points in common frequency bands and at the frequency of magnetic fields was evaluated by paired t-test.Results: Exposure of Central area by local magnetic field caused significant change (p<0.05 in the forehead alpha band. Reduction in the alpha band over central area was observed when temporal area was exposed to ELF MF.Conclusion: The results showed that resonance effect in the brain signals caused by local magnetic field exposure was not observed and change in every part of the relative power spectrum might occur. The changes in the EEG bands were not limited necessarily to the exposure point.

  10. Strong relationship between oral dose and tenofovir hair levels in a randomized trial: hair as a potential adherence measure for pre-exposure prophylaxis (PrEP.

    Directory of Open Access Journals (Sweden)

    Albert Y Liu

    Full Text Available Pre-exposure prophylaxis (PrEP trials using tenofovir-based regimens have demonstrated that high levels of adherence are required to evaluate efficacy; the incorporation of objective biomarkers of adherence in trial design has been essential to interpretation, given the inaccuracy of self-report. Antiretroviral measurements in scalp hair have been useful as a marker of long-term exposure in the HIV treatment setting, and hair samples are relatively easy and inexpensive to collect, transport, and store for analysis. To evaluate the relationship between dose and tenofovir concentrations in hair, we examined the dose proportionality of tenofovir in hair in healthy, HIV-uninfected adults.A phase I, crossover pharmacokinetic study was performed in 24 HIV-negative adults receiving directly-observed oral tenofovir tablets administered 2, 4, and 7 doses/week for 6 weeks, with a ≥3-week break between periods. Small samples of hair were collected after each six-week period and analyzed for tenofovir concentrations. Geometric-mean-ratios compared levels between each pair of dosing conditions. Intensive plasma pharmacokinetic studies were performed during the daily-dosing period to calculate areas-under-the-time-concentration curves (AUCs.Over 90% of doses were observed per protocol. Median tenofovir concentrations in hair increased monotonically with dose. A log-linear relationship was seen between dose and hair levels, with an estimated 76% (95% CI 60-93% increase in hair level per 2-fold dose increase. Tenofovir plasma AUCs modestly predicted drug concentrations in hair.This study found a strong linear relationship between frequency of dosing and tenofovir levels in scalp hair. The analysis of quantitative drug levels in hair has the potential to improve adherence measurement in the PrEP field and may be helpful in determining exposure thresholds for protection and explaining failures in PrEP trials. Hair measures for adherence monitoring may also

  11. Trauma-related shame and guilt as time-varying predictors of posttraumatic stress disorder symptoms during imagery exposure and imagery rescripting--A randomized controlled trial.

    Science.gov (United States)

    Øktedalen, Tuva; Hoffart, Asle; Langkaas, Tomas Formo

    2015-01-01

    The specific aims of this study are to examine trauma-related shame and guilt as time-varying predictors of symptoms of posttraumatic stress disorder (PTSD). Sixty-five patients were included in the statistical analyses and the multilevel modeling analyses supported three major findings. (i) Patients with a higher level of shame and guilt at the start of treatment displayed a higher level of PTSD symptoms over the course of treatment compared to other patients. (ii) Time-specific change in shame and guilt predicted the level of PTSD symptoms 3 days later from session to session during treatment. (iii) No significant differences were evident between prolonged exposure (PE) and modified PE to include imagery rescripting in the within-person process of change in PTSD symptoms from session to session during therapy. This trial reports the first evidence that within-person change in shame and guilt predicts change in PTSD symptoms from session to session during treatment.

  12. A randomly-controlled study on the cardiac function at the early stage of return to the plains after short-term exposure to high altitude.

    Directory of Open Access Journals (Sweden)

    Qiquan Zhou

    Full Text Available High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m and returned to the plains (1500 m after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP, left ventricular ejection fraction (LVEF, left ventricular fraction shortening (LVFS, cardiac function index (Tei index were tested. Levels of serum creatine kinase isoform MB (CK-MB, lactate dehydrogenase isoenzyme-1 (LDH-1, endothelin-1 (ET-1, nitrogen oxide (NO, serum hypoxia-inducible factor-1α (HIF-1α, 8-iso-prostaglandin F(2α (8-iso PGF(2α, superoxide dismutase (SOD and malonaldehyde (MDA were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15(th day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (P<0.01. We also found that changes in Tei index was positively correlated with mPAP, ET-1, HIF-1α and 8-iso PGF(2α levels, and negatively correlated with the level of NO, LVEF, LVFS, CK-MB and LDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time.

  13. Aperiodic order

    CERN Document Server

    Grimm, Uwe

    2017-01-01

    Quasicrystals are non-periodic solids that were discovered in 1982 by Dan Shechtman, Nobel Prize Laureate in Chemistry 2011. The mathematics that underlies this discovery or that proceeded from it, known as the theory of Aperiodic Order, is the subject of this comprehensive multi-volume series. This second volume begins to develop the theory in more depth. A collection of leading experts, among them Robert V. Moody, cover various aspects of crystallography, generalising appropriately from the classical case to the setting of aperiodically ordered structures. A strong focus is placed upon almost periodicity, a central concept of crystallography that captures the coherent repetition of local motifs or patterns, and its close links to Fourier analysis. The book opens with a foreword by Jeffrey C. Lagarias on the wider mathematical perspective and closes with an epilogue on the emergence of quasicrystals, written by Peter Kramer, one of the founders of the field.

  14. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

    Statistical Tests That Do Not Require Random Sampling Randomization Tests Numerical Examples Randomization Tests and Nonrandom Samples The Prevalence of Nonrandom Samples in Experiments The Irrelevance of Random Samples for the Typical Experiment Generalizing from Nonrandom Samples Intelligibility Respect for the Validity of Randomization Tests Versatility Practicality Precursors of Randomization Tests Other Applications of Permutation Tests Questions and Exercises Notes References Randomized Experiments Unique Benefits of Experiments Experimentation without Mani

  15. Response of Vitamin D Concentration to Vitamin D3 Administration in Older Adults without Sun Exposure: A Randomized Double-Blind Trial.

    Science.gov (United States)

    Schwartz, Janice B; Kane, Lynn; Bikle, Daniel

    2016-01-01

    To determine the dose-response relationship between 25-hydroxyvitamin D (25(OH)D) and supplemental vitamin D3 in elderly nursing home residents. Randomized double-blind investigation. Nursing home. Of 81 women (n=51) and men (n=30) (mean age 87.4±8) enrolled, 72 completed the study. Sixteen weeks of oral vitamin D3 at 800, 2,000, or 4,000 IU/d or 50,000 IU/wk. The main outcome was 25(OH)D concentrations (tandem mass spectrometry) after 16 weeks. Free 25(OH)D and intact parathyroid hormone (iPTH) were also analyzed. Safety monitoring of calcium and estimated glomerular filtration rate was performed, and adherence and clinical status were measured. 25(OH)D concentrations increased with dose (Pd than 800 or 2,000 IU/d, but 800 IU and 2,000 IU/d did not differ. One subject receiving 800 IU/d had concentrations less than 20 ng/mL. All subjects receiving more than 2000 IU/d had concentrations of 20 ng/mL and greater. Free 25(OH)D concentrations rose with total 25(OH) vitamin D. Total and free 25(OH)D were related to calcium concentrations; only free 25(OH)D was related to iPTH. 25(OH)D increased linearly with 800 to 4,000 IU/d and 50,000 IU/wk of vitamin D3, without a ceiling effect. Data suggest that some elderly adults will require more than 800 IU/d of vitamin D3 to ensure adequate vitamin D levels. Changes in 25(OH)D with vitamin D3 were related to starting concentrations (greatest with the lowest concentrations and unchanged with 800 and 2,000 IU/d if 20-40 ng/mL). Relationships between serum calcium and iPTH and free 25(OH)D suggest the potential for free 25(OH)D in defining optimal 25(OH)D concentrations. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

  16. Premeal Low-Fat Yogurt Consumption Reduces Postprandial Inflammation and Markers of Endotoxin Exposure in Healthy Premenopausal Women in a Randomized Controlled Trial

    Science.gov (United States)

    Pei, Ruisong; DiMarco, Diana M; Putt, Kelley K; Martin, Derek A; Chitchumroonchokchai, Chureeporn; Bruno, Richard S; Bolling, Bradley W

    2018-01-01

    Abstract Background Metabolic endotoxemia is associated with obesity and contributes to postprandial inflammation. Objective We aimed to determine if low-fat yogurt consumption prevents postprandial inflammation and dysmetabolism in healthy women by inhibiting biomarkers of metabolic endotoxemia. Methods Premenopausal women defined as obese and nonobese [body mass index (BMI, in kg/m2) 30–40 and 18.5–27, respectively, n = 120] were randomly assigned to consume 339 g of low-fat yogurt (YN, yogurt nonobese; YO, yogurt obese) or 324 g of soy pudding (CN, control nonobese; CO, control obese) for 9 wk (n = 30/group). The intervention foods each supplied 330 kcal with 3 g fat, 66 g carbohydrate, and 4–6 g protein. At weeks 0 and 9, participants ingested 226 g of yogurt or 216 g of soy pudding before a meal providing 56–60 g fat, 82 g carbohydrate, and 28–30 g protein. Plasma soluble CD14 (sCD14), lipopolysaccharide-binding protein (LBP), LPS activity, interleukin-6 (IL-6), glucose, triglyceride, and insulin were measured hourly for 4 h to assess differences in postprandial responses between groups by 2-factor ANOVA. Results Premeal yogurt consumption prevented the postprandial decrease in sCD14 net incremental area under the curve (net iAUC) by 72% in obese individuals at week 0 (P = 0.0323). YN and YO had ≥40% lower net iAUC of LBP-to-sCD14 ratio and plasma IL-6 concentration than CN and CO, respectively (P yogurt consumption, ΔAUC of LBP-to-sCD14 ratios of YO and YN were less than half of those of the control groups (P = 0.0093). Conclusion Yogurt consumption improved postprandial metabolism and biomarkers of metabolic endotoxemia in healthy premenopausal women. Premeal yogurt consumption is a feasible strategy to inhibit postprandial dysmetabolism and thus may reduce cardiometabolic risk. This trial was registered at clinicaltrials.gov as NCT01686204. PMID:29767743

  17. A healthy diet with and without cereal grains and dairy products in patients with type 2 diabetes: study protocol for a random-order cross-over pilot study--Alimentation and Diabetes in Lanzarote--ADILAN.

    Science.gov (United States)

    Fontes-Villalba, Maelán; Jönsson, Tommy; Granfeldt, Yvonne; Frassetto, Lynda A; Sundquist, Jan; Sundquist, Kristina; Carrera-Bastos, Pedro; Fika-Hernándo, María; Picazo, Óscar; Lindeberg, Staffan

    2014-01-02

    Research on the role of nutrition in type 2 diabetes has largely focused on macro/micronutrient composition and dietary fiber intake, while fewer studies have tested the effects of differing food choice. Some observational studies and short-term intervention studies suggest that a food pattern mimicking the diet with which humans evolved positively influences glucose control and associated endocrine systems. Such a food pattern mainly differs from other common healthy food patterns in its absence of cereal grains and dairy products. The primary aim of this pilot study is to determine the effect of two healthy diets with or without cereal grains and dairy products on glucose control, while keeping participants' weight stable and other food parameters, such as macro/micronutrient composition, dietary fiber and glycemic load, the same in both diets. We intend to include 15 adult patients with a medical diagnosis of type 2 diabetes mellitus with or without medication and with an increased waist circumference (≥ 80 cm for women and ≥ 94 cm for men) in a random-order cross-over diet intervention study during two periods of four-weeks separated by a six-week washout period. Patients will be instructed to eat two healthy diets according to official dietary guidelines with respect to macro/micronutrient composition and fiber content, but differing in the type of food included, with one diet being without cereal grains and dairy products. Lunch will be served in a hospital kitchen for control of nutrient intake, while the rest of the meals will be eaten at home according to specific directions. The energy content of the diets will be individually adjusted to maintain a stable body weight during the two four-week intervention periods. Primary outcomes will be change in fasting plasma glucagon and fructosamine, while secondary outcomes include change in fasting glucose and glycated hemoglobin, glucose and glucagon response during oral glucose tolerance test, blood

  18. A healthy diet with and without cereal grains and dairy products in patients with type 2 diabetes: study protocol for a random-order cross-over pilot study - Alimentation and Diabetes in Lanzarote -ADILAN

    Science.gov (United States)

    2014-01-01

    Background Research on the role of nutrition in type 2 diabetes has largely focused on macro/micronutrient composition and dietary fiber intake, while fewer studies have tested the effects of differing food choice. Some observational studies and short-term intervention studies suggest that a food pattern mimicking the diet with which humans evolved positively influences glucose control and associated endocrine systems. Such a food pattern mainly differs from other common healthy food patterns in its absence of cereal grains and dairy products. The primary aim of this pilot study is to determine the effect of two healthy diets with or without cereal grains and dairy products on glucose control, while keeping participants’ weight stable and other food parameters, such as macro/micronutrient composition, dietary fiber and glycemic load, the same in both diets. Methods/Design We intend to include 15 adult patients with a medical diagnosis of type 2 diabetes mellitus with or without medication and with an increased waist circumference (≥ 80 cm for women and ≥ 94 cm for men) in a random-order cross-over diet intervention study during two periods of four-weeks separated by a six-week washout period. Patients will be instructed to eat two healthy diets according to official dietary guidelines with respect to macro/micronutrient composition and fiber content, but differing in the type of food included, with one diet being without cereal grains and dairy products. Lunch will be served in a hospital kitchen for control of nutrient intake, while the rest of the meals will be eaten at home according to specific directions. The energy content of the diets will be individually adjusted to maintain a stable body weight during the two four-week intervention periods. Primary outcomes will be change in fasting plasma glucagon and fructosamine, while secondary outcomes include change in fasting glucose and glycated hemoglobin, glucose and glucagon response during oral

  19. Exposure Forecaster

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Exposure Forecaster Database (ExpoCastDB) is EPA's database for aggregating chemical exposure information and can be used to help with chemical exposure...

  20. Does the therapy manual or the therapist matter most in treatment of obsessive-compulsive disorder? A randomized controlled trial of exposure with response or ritual prevention in 118 patients.

    Science.gov (United States)

    van Oppen, Patricia; van Balkom, Anton J L M; Smit, Johannes H; Schuurmans, Josien; van Dyck, Richard; Emmelkamp, Paul M G

    2010-09-01

    The importance of the therapist's education and experience for the successful behavior treatment of obsessive-compulsive disorder (OCD) has not been investigated. Data on the relative effectiveness of self-controlled versus therapist-controlled in vivo exposure with response or ritual prevention (ERP) have yielded conflicting results. The present study compared the effectiveness of 4 different modes of delivery of ERP in a referred sample of OCD patients. Of the 146 eligible OCD outpatients, 118 patients enrolled in this randomized controlled trial and were randomly assigned to (1) therapist-controlled ERP performed by experienced behavior therapists; (2) therapist-controlled ERP performed by master's students of clinical psychology; (3) self-controlled ERP performed by experienced behavior therapists; and (4) self-controlled ERP performed by master's students of clinical psychology. This trial was performed from January 1999 to January 2005. Our analyses revealed no significant differences in clinical outcome between any of the different modes of delivery of ERP at posttreatment. The different ERP modes of delivery were associated with significant pretreatment to posttreatment improvement on all measurements, with large effect sizes on the primary outcome measure, the Yale-Brown Obsessive Compulsive Scale. Our results indicate that clinically inexperienced master's students with no postgraduate training can be as capable as experienced and certified behavior therapists in treating OCD patients, as long as therapists adhere to a standardized treatment manual and adequate training and supervision is provided. In contrast to other studies, we did not find a supposed benefit of therapist-controlled ERP versus self-controlled ERP in patients with OCD. www.trialregister.nl Identifier: NTR1444. © Copyright 2010 Physicians Postgraduate Press, Inc.

  1. Challenges in higher order mode Raman amplifiers

    DEFF Research Database (Denmark)

    Rottwitt, Karsten; Nielsen, Kristian; Friis, Søren Michael Mørk

    2015-01-01

    A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed......A higher order Raman amplifier model that take random mode coupling into account ispresented. Mode dependent gain and signal power fluctuations at the output of the higher order modeRaman amplifier are discussed...

  2. A pilot randomized controlled trial of Dialectical Behavior Therapy with and without the Dialectical Behavior Therapy Prolonged Exposure protocol for suicidal and self-injuring women with borderline personality disorder and PTSD.

    Science.gov (United States)

    Harned, Melanie S; Korslund, Kathryn E; Linehan, Marsha M

    2014-04-01

    This study evaluates the efficacy of integrating PTSD treatment into Dialectical Behavior Therapy (DBT) for women with borderline personality disorder, PTSD, and intentional self-injury. Participants were randomized to DBT (n=9) or DBT with the DBT Prolonged Exposure (DBT PE) protocol (n=17) and assessed at 4-month intervals during the treatment year and 3-months post-treatment. Treatment expectancies, satisfaction, and completion did not differ by condition. In DBT+DBT PE, the DBT PE protocol was feasible to implement for a majority of treatment completers. Compared to DBT, DBT+DBT PE led to larger and more stable improvements in PTSD and doubled the remission rate among treatment completers (80% vs. 40%). Patients who completed the DBT PE protocol were 2.4 times less likely to attempt suicide and 1.5 times less likely to self-injure than those in DBT. Among treatment completers, moderate to large effect sizes favored DBT+DBT PE for dissociation, trauma-related guilt cognitions, shame, anxiety, depression, and global functioning. DBT with the DBT PE protocol is feasible, acceptable, and safe to administer, and may lead to larger improvements in PTSD, intentional self-injury, and other outcomes than DBT alone. The findings require replication in a larger sample. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Random walk on random walks

    NARCIS (Netherlands)

    Hilário, M.; Hollander, den W.Th.F.; Sidoravicius, V.; Soares dos Santos, R.; Teixeira, A.

    2014-01-01

    In this paper we study a random walk in a one-dimensional dynamic random environment consisting of a collection of independent particles performing simple symmetric random walks in a Poisson equilibrium with density ¿¿(0,8). At each step the random walk performs a nearest-neighbour jump, moving to

  4. Assessment of exposures to ionizing radiation in industries and activities implementing raw materials which naturally contain radionuclides and which are not used because of their radioactive properties. Assessment of the 25. of May 2005 Order related to these activities

    International Nuclear Information System (INIS)

    2009-12-01

    This report proposes an assessment of the exposure of workers and of population to reinforced natural radioactivity associated to some particular professional activities, i.e. activities where raw materials which are used, are naturally radioactive, for example: coal combustion in thermal power plants, ore processing (tin, aluminium, copper, titanium, niobium, bismuth, thorium), production of refractory ceramics, production or use of thorium compounds, zircon or baddeleyite production, and so on. After a presentation of the French national regulation, the report gives an assessment of its application through different measurements or surveys, notably dosimetry performed on workers or population exposure measurements, or some waste management activities. It discusses the evolution opportunities of this regulation, either in the French framework or at the European level

  5. Safety, adherence and acceptability of intermittent tenofovir/emtricitabine as HIV pre-exposure prophylaxis (PrEP among HIV-uninfected Ugandan volunteers living in HIV-serodiscordant relationships: a randomized, clinical trial.

    Directory of Open Access Journals (Sweden)

    Freddie M Kibengo

    Full Text Available BACKGROUND: Efficacy of oral pre-exposure prophylaxis (PrEP in prevention of HIV acquisition has been evaluated using a daily regimen. However, adherence to long term daily medication is rarely perfect. Intermittent regimen may be a feasible alternative. Preclinical studies have demonstrated effectiveness of intermittent PrEP in SHIV prevention among animals. However, little is known about intermittent PrEP regimens. DESIGN: Seventy two HIV-uninfected volunteers in HIV serodiscordant couple relationships in Uganda were randomly assigned to receive daily oral Tenofovir/Emtricitabine (TDF/FTC-Truvada or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day oral TDF/FTC or placebo in a 2:1:2:1 ratio. Volunteers and study staff were blinded to drug assignment, but not to regimen assignment. METHODS: Volunteers were followed for 4 months after randomization, with monthly clinical and laboratory safety assessments and comprehensive HIV risk reduction services. Adherence was monitored using medication event monitoring system (MEMS and self-report. Sexual activity data were collected via daily short text message (SMS and self-report. HIV-specific immune responses were assessed by IFN-γ ELISPOT. RESULTS: Both daily and intermittent oral TDF/FTC regimens were well tolerated. Median MEMS adherence rates were 98% (IQR: 93-100 for daily PrEP regimen, 91% (IQR: 73-97 for fixed intermittent dosing and 45% (IQR: 20-63 for post-coital dosing. SMS response rate was 74%, but increased to 80% after excluding server outages; results may have been affected by the novelty of this measure. The majority of volunteers expressed willingness with no particular preference for either regimen. CONCLUSIONS: Both daily and intermittent oral PrEP dosing regimens were safe. Adherence was high for daily and fixed intermittent dosing; post-coital dosing was associated with poor adherence. Fixed intermittent PrEP regimens may be

  6. Order Aggressiveness and Order Book Dynamics

    OpenAIRE

    Anthony D. Hall; Nikolaus Hautsch

    2004-01-01

    In this paper, we study the determinants of order aggressiveness and traders' order submission strategy in an open limit order book market. Using order book data from the Australian Stock Exchange, we model traders' aggressiveness in market trading, limit order trading as well as in order cancellations on both sides of the market using a six-dimensional autoregressive intensity model. The information revealed by the open order book plays an important role in explaining the degree of order agg...

  7. Random magnetism

    International Nuclear Information System (INIS)

    Tahir-Kheli, R.A.

    1975-01-01

    A few simple problems relating to random magnetic systems are presented. Translational symmetry, only on the macroscopic scale, is assumed for these systems. A random set of parameters, on the microscopic scale, for the various regions of these systems is also assumed. A probability distribution for randomness is obeyed. Knowledge of the form of these probability distributions, is assumed in all cases [pt

  8. A Randomized, Double-blind Evaluation of D-cycloserine or Alprazolam Combined with Virtual Reality Exposure Therapy for Posttraumatic Stress Disorder (PTSD) in Iraq and Afghanistan War Veterans

    Science.gov (United States)

    Rothbaum, Barbara Olasov; Price, Matthew; Jovanovic, Tanja; Norrholm, Seth D.; Gerardi, Maryrose; Dunlop, Boadie; Davis, Michael; Bradley, Bekh; Duncan, Erica; Rizzo, Albert “Skip”; Ressler, Kerry J.

    2014-01-01

    Objective To determine the effectiveness of Virtual Reality Exposure (VRE) augmented with D-cycloserine (50mg) or alprazolam (0.25mg), compared to placebo, in reducing PTSD due to military trauma in Iraq and Afghanistan. Method A double-blind, placebo-controlled randomized clinical trial comparing augmentation methods for VRE for subjects (n= 156) with PTSD was conducted. Results PTSD symptoms significantly improved from pre- to post-treatment over the 6-session VRE treatment (p<.001) across all conditions and were maintained at 3, 6, and 12 months follow-up. There were no overall differences between the D-cycloserine group on symptoms at any time-point. The alprazolam and placebo conditions significantly differed on the post-treatment Clinician Administered PTSD scale (p = .006) and the 3-month post-treatment PTSD diagnosis, such that the alprazolam group showed greater rates of PTSD (79.2% alprazolam vs. 47.8% placebo). Between-session extinction learning was a treatment-specific enhancer of outcome for the D-cycloserine group only (p<.005). At post-treatment, the D-cycloserine group was the lowest on cortisol reactivity (p<.05) and startle response during VR scenes (p<.05). Conclusions A small number of VRE sessions were associated with reduced PTSD diagnosis and symptoms in Iraq/Afghanistan veterans, although there was no control condition for the VRE. Overall, there was no advantage of D-cycloserine on PTSD symptoms in primary analyses. In secondary analyses, benzodiazepine use during treatment may impair recovery, and D-cycloserine may enhance VRE in patients who demonstrate within-session learning. D-cycloserine augmentation treatment in PTSD patients may reduce cortisol and startle reactivity compared to the alprazolam and placebo treatment, consistent with the animal literature. PMID:24743802

  9. Correlation order, merging and diversification

    NARCIS (Netherlands)

    Dhaene, J.; Denuit, M.; Vanduffel, S.

    2009-01-01

    We investigate the influence of the dependence between random losses on the shortfall and on the diversification benefit that arises from merging these losses. We prove that increasing the dependence between losses, expressed in terms of correlation order, has an increasing effect on the shortfall,

  10. Radiation exposure during ESWL

    International Nuclear Information System (INIS)

    McCullough, D.L.; Van Swearingen, F.L.; Dyer, R.B.; Appel, B.

    1987-01-01

    This paper discusses exposure to ionizing radiation by the ESWL patient and for health professionals. Although the patient is exposed acutely to the highest level of radiation, the lithotripter team is chronically exposed to ionizing radiation at varying levels. Attention to detail is important in reducing that exposure. The operator should follow the guidelines set forth in this chapter in order to minimize exposure to the patient, himself or herself, and to all co-workers. At the present time, investigation of an alternative modality for stone localization, ultrasound, is being investigated

  11. Randomized random walk on a random walk

    International Nuclear Information System (INIS)

    Lee, P.A.

    1983-06-01

    This paper discusses generalizations of the model introduced by Kehr and Kunter of the random walk of a particle on a one-dimensional chain which in turn has been constructed by a random walk procedure. The superimposed random walk is randomised in time according to the occurrences of a stochastic point process. The probability of finding the particle in a particular position at a certain instant is obtained explicitly in the transform domain. It is found that the asymptotic behaviour for large time of the mean-square displacement of the particle depends critically on the assumed structure of the basic random walk, giving a diffusion-like term for an asymmetric walk or a square root law if the walk is symmetric. Many results are obtained in closed form for the Poisson process case, and these agree with those given previously by Kehr and Kunter. (author)

  12. Exposure levels and determinants of inhalable dust exposure in bakeries.

    Science.gov (United States)

    Burstyn, I; Teschke, K; Kennedy, S M

    1997-12-01

    The study's objectives were to measure full-shift exposure to inhalable dust in bakeries and define the determinants of full-shift exposure. Inhalable dust was measured gravimetrically. Ninety-six bakery workers, employed in seven different bakeries, participated in the study. Two side-by-side full-shift inhalable dust samples were obtained from each study participant on a single occasion. Samples were collected on 18 days selected at random. During the entire sampling period, bakers were observed and information on 14 different tasks was recorded at 15 min intervals. Other production characteristics were also recorded for each sampling day. These task and production variables were used in statistical modelling to identify significant predictors of exposure. The mean full-shift inhalable dust exposure was 8.2 mg/m3 (range: 0.1-110 mg/m3). A regression model explained 79% of the variability in exposure. The model indicated that tasks such as weighing, pouring and operating dough-brakers and reversible sheeters increased the exposure, while packing, catching and decorating decreased the exposure. Bread and bun production lines were associated with increased full-shift inhalable dust exposure, while cake production and substitution of dusting with the use of divider oil were associated with decreased exposure. Production tasks and characteristics are strong predictors of personal full-shift exposures to flour dust among bakers; these can be altered to reduce exposure levels.

  13. PrEP Chicago: A randomized controlled peer change agent intervention to promote the adoption of pre-exposure prophylaxis for HIV prevention among young Black men who have sex with men.

    Science.gov (United States)

    Young, Lindsay E; Schumm, Phil; Alon, Leigh; Bouris, Alida; Ferreira, Matthew; Hill, Brandon; Khanna, Aditya S; Valente, Thomas W; Schneider, John A

    2018-02-01

    Advances in biomedical prevention strategies such as pre-exposure prophylaxis (PrEP) represent a new opportunity for reducing HIV incidence among young Black men who have sex with men, for whom the number of new HIV infections continues to rise. However, studies have documented low rates of PrEP uptake in this community. Research suggests that the peer networks of young Black men who have sex with men play important roles in their sexual health decisions. PrEP Chicago is a randomized controlled trial network intervention designed to increase PrEP uptake among young Black men who have sex with men living in Chicago. The aims of this study are twofold. Aim 1 is to estimate the effectiveness of a peer change agent intervention for (1) increasing the number of referrals made to a PrEP information line, (2) increasing the rate of PrEP adoption among non-participant peers, and (3) increasing PrEP knowledge, attitudes, and intentions among participants. Aim 2 is to determine the individual and network variables that explain peer change agent effectiveness. PrEP Chicago is a social network intervention that utilizes the influence of peer change agents to link young Black men who have sex with men in Chicago to PrEP. Young Black men who have sex with men were recruited using respondent-driven sampling. Once screened for eligibility, participants were randomly assigned to either one of two treatment sequences: (1) intervention treatment in Year 1 followed by a minimal contact attention control in Year 2 or (2) the minimal contact attention control in Year 1 followed by treatment in Year 2. The treatment consists of a PrEP/peer change agent training workshop followed by booster calls for 12 months. The attention control consists of a sex diary activity designed to help participants assess sexual risk. Psychosocial, sexual health, and network data are collected from all participants at baseline and at 12- and 24-month follow-ups. In total, 423 participants aged 18-35 have

  14. Clinical trial of modulatory effects of oxytocin treatment on higher-order social cognition in autism spectrum disorder: a randomized, placebo-controlled, double-blind and crossover trial.

    Science.gov (United States)

    Preckel, Katrin; Kanske, Philipp; Singer, Tania; Paulus, Frieder M; Krach, Sören

    2016-09-21

    Autism spectrum disorders are neurodevelopmental conditions with severe impairments in social communication and interaction. Pioneering research suggests that oxytocin can improve motivation, cognition and attention to social cues in patients with autism spectrum disorder. The aim of this clinical trial is to characterize basic mechanisms of action of acute oxytocin treatment on neural levels and to relate these to changes in different levels of socio-affective and -cognitive functioning. This clinical study is a randomized, double-blind, cross-over, placebo-controlled, multicenter functional magnetic resonance imaging study with two arms. A sample of 102 male autism spectrum disorder patients, diagnosed with Infantile Autistic Disorder (F84.0 according to ICD-10), Asperger Syndrome (F84.5 according to ICD-10), or Atypical Autism (F84.1 according to ICD-10) will be recruited and will receive oxytocin and placebo nasal spray on two different days. Autism spectrum disorder patients will be randomized to determine who receives oxytocin on the first and who on the second visit. Healthy control participants will be recruited and case-control matched to the autism spectrum disorder patients. The primary outcome will be neural network activity, measured with functional magnetic resonance imaging while participants perform socio-affective and -cognitive tasks. Behavioral markers such as theory of mind accuracy ratings and response times will be assessed as secondary outcomes in addition to physiological measures such as skin conductance. Trait measures for alexithymia, interpersonal reactivity, and social anxiety will also be evaluated. Additionally, we will analyze the effect of oxytocin receptor gene variants and how these potentially influence the primary and secondary outcome measures. Functional magnetic resonance imaging assessments will take place at two time points which will be scheduled at least two weeks apart to ensure a sufficient wash-out time after oxytocin

  15. The effectiveness and cost evaluation of pain exposure physical therapy and conventional therapy in patients with complex regional pain syndrome type 1. Rationale and design of a randomized controlled trial

    NARCIS (Netherlands)

    Barnhoorn, K.J.; Oostendorp, R.A.B.; van Dongen, R.T.M.; Klomp, F.P.; Samwel, H.; van der Wilt, G.J.; Adang, E.M.M.; Groenewoud, H.; van de Meent, H.; Frolke, J.P.M.

    2012-01-01

    Background: Pain Exposure Physical Therapy is a new treatment option for patients with Complex Regional Pain Syndrome type 1. It has been evaluated in retrospective as well as in prospective studies and proven to be safe and possibly effective. This indicates that Pain Exposure Physical Therapy is

  16. Order aggressiveness and order book dynamics

    DEFF Research Database (Denmark)

    Hall, Anthony D.; Hautsch, Nikolaus

    2006-01-01

    In this paper, we study the determinants of order aggressiveness and traders’ order submission strategy in an open limit order book market. Applying an order classification scheme, we model the most aggressive market orders, limit orders as well as cancellations on both sides of the market...... employing a six-dimensional autoregressive conditional intensity model. Using order book data from the Australian Stock Exchange, we find that market depth, the queued volume, the bid-ask spread, recent volatility, as well as recent changes in both the order flow and the price play an important role...... in explaining the determinants of order aggressiveness. Overall, our empirical results broadly confirm theoretical predictions on limit order book trading. However, we also find evidence for behavior that can be attributed to particular liquidity and volatility effects...

  17. Autonomous Byte Stream Randomizer

    Science.gov (United States)

    Paloulian, George K.; Woo, Simon S.; Chow, Edward T.

    2013-01-01

    Net-centric networking environments are often faced with limited resources and must utilize bandwidth as efficiently as possible. In networking environments that span wide areas, the data transmission has to be efficient without any redundant or exuberant metadata. The Autonomous Byte Stream Randomizer software provides an extra level of security on top of existing data encryption methods. Randomizing the data s byte stream adds an extra layer to existing data protection methods, thus making it harder for an attacker to decrypt protected data. Based on a generated crypto-graphically secure random seed, a random sequence of numbers is used to intelligently and efficiently swap the organization of bytes in data using the unbiased and memory-efficient in-place Fisher-Yates shuffle method. Swapping bytes and reorganizing the crucial structure of the byte data renders the data file unreadable and leaves the data in a deconstructed state. This deconstruction adds an extra level of security requiring the byte stream to be reconstructed with the random seed in order to be readable. Once the data byte stream has been randomized, the software enables the data to be distributed to N nodes in an environment. Each piece of the data in randomized and distributed form is a separate entity unreadable on its own right, but when combined with all N pieces, is able to be reconstructed back to one. Reconstruction requires possession of the key used for randomizing the bytes, leading to the generation of the same cryptographically secure random sequence of numbers used to randomize the data. This software is a cornerstone capability possessing the ability to generate the same cryptographically secure sequence on different machines and time intervals, thus allowing this software to be used more heavily in net-centric environments where data transfer bandwidth is limited.

  18. On randomly interrupted diffusion

    International Nuclear Information System (INIS)

    Luczka, J.

    1993-01-01

    Processes driven by randomly interrupted Gaussian white noise are considered. An evolution equation for single-event probability distributions in presented. Stationary states are considered as a solution of a second-order ordinary differential equation with two imposed conditions. A linear model is analyzed and its stationary distributions are explicitly given. (author). 10 refs

  19. Occupational Exposure Assessment of Tehran Metro Drivers to Extremely Low Frequency Magnetic Fields

    Directory of Open Access Journals (Sweden)

    mohammad reza Monazzam

    2016-03-01

    Full Text Available Introduction: Occupational exposure to Extremely Low Frequency Magnetic Fields (ELF-MFs in train drivers is an integral part of the driving task and creates concern about driving jobs. The present study was designed to investigate the occupational exposure of Tehran train drivers to extremely low frequency magnetic fields. Methods: In order to measure the driver’s exposure, from each line, a random sample in AC and DC type trains was selected and measurements were done according to the IEEE std 644-1994 using a triple axis TES-394 device. Train drivers were then compared with national occupational exposure limit guidelines. Results: The maximum and minimum mean exposure was found in AC external city trains (1.2±1.5 μT and DC internal city trains (0.31±0.2 μT, respectively. The maximum and minimum exposure was 9 μT and 0.08 μT in AC trains of line 5, respectively. In the internal train line, maximum and minimum values were 5.4 μT and 0.08 μT in AC trains. Conclusions: In none of the exposure scenarios in different trains, the exposure exceeded the national or international occupational exposure limit guidelines. However, this should not be the basis of safety in these fields

  20. Solution Methods for Structures with Random Properties Subject to Random Excitation

    DEFF Research Database (Denmark)

    Köylüoglu, H. U.; Nielsen, Søren R. K.; Cakmak, A. S.

    This paper deals with the lower order statistical moments of the response of structures with random stiffness and random damping properties subject to random excitation. The arising stochastic differential equations (SDE) with random coefficients are solved by two methods, a second order...... the SDE with random coefficients with deterministic initial conditions to an equivalent nonlinear SDE with deterministic coefficient and random initial conditions. In both methods, the statistical moment equations are used. Hierarchy of statistical moments in the markovian approach is closed...... by the cumulant neglect closure method applied at the fourth order level....

  1. Natural radio-exposure

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Although the amounts are small, man is exposed on a daily basis to alpha, beta, and gamma radiation emitted by radioactive elements present in the earth's crust. The natural radioactive elements are measurable, either by physicochemical means or by radiometric methods and can be the cause of external or internal exposure in man. Also of importance is cosmic radiation. Of galactic or solar origin, primary cosmic rays cause external radiation exposure. The majority of these particles disintegrate rapidly. They reach the ground at a mean rate of the order of one particle per square centimeter per minute

  2. Experimental effects of exposure to pornography

    DEFF Research Database (Denmark)

    Hald, Gert Martin; Malamuth, Neil N

    2015-01-01

    Using a randomly selected community sample of 200 Danish young adult men and women in a randomized experimental design, the study investigated the effects of a personality trait (agreeableness), past pornography consumption, and experimental exposure to non-violent pornography on attitudes...... supporting violence against women (ASV). We found that lower levels of agreeableness and higher levels of past pornography consumption significantly predicted ASV. In addition, experimental exposure to pornography increased ASV but only among men low in agreeableness. This relationship was found...

  3. Reconstructing random media

    International Nuclear Information System (INIS)

    Yeong, C.L.; Torquato, S.

    1998-01-01

    We formulate a procedure to reconstruct the structure of general random heterogeneous media from limited morphological information by extending the methodology of Rintoul and Torquato [J. Colloid Interface Sci. 186, 467 (1997)] developed for dispersions. The procedure has the advantages that it is simple to implement and generally applicable to multidimensional, multiphase, and anisotropic structures. Furthermore, an extremely useful feature is that it can incorporate any type and number of correlation functions in order to provide as much morphological information as is necessary for accurate reconstruction. We consider a variety of one- and two-dimensional reconstructions, including periodic and random arrays of rods, various distribution of disks, Debye random media, and a Fontainebleau sandstone sample. We also use our algorithm to construct heterogeneous media from specified hypothetical correlation functions, including an exponentially damped, oscillating function as well as physically unrealizable ones. copyright 1998 The American Physical Society

  4. Certified higher-order recursive path ordering

    NARCIS (Netherlands)

    Koprowski, A.; Pfenning, F.

    2006-01-01

    The paper reports on a formalization of a proof of wellfoundedness of the higher-order recursive path ordering (HORPO) in the proof checker Coq. The development is axiom-free and fully constructive. Three substantive parts that could be used also in other developments are the formalizations of the

  5. Topological orders in rigid states

    International Nuclear Information System (INIS)

    Wen, X.G.

    1990-01-01

    The authors study a new kind of ordering topological order in rigid states (the states with no local gapless excitations). This paper concentrates on characterization of the different topological orders. As an example the authors discuss in detail chiral spin states of 2+1 dimensional spin systems. Chiral spin states are described by the topological Chern-Simons theories in the continuum limit. The authors show that the topological orders can be characterized by a non-Abelian gauge structure over the moduli space which parametrizes a family of the model Hamiltonians supporting topologically ordered ground states. In 2 + 1 dimensions, the non-Abelian gauge structure determines possible fractional statistics of the quasi-particle excitations over the topologically ordered ground states. The dynamics of the low lying global excitations is shown to be independent of random spatial dependent perturbations. The ground state degeneracy and the non-Abelian gauge structures discussed in this paper are very robust, even against those perturbations that break translation symmetry. The authors also discuss the symmetry properties of the degenerate ground states of chiral spin states. The authors find that some degenerate ground states of chiral spin states on torus carry non-trivial quantum numbers of the 90 degrees rotation

  6. Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J.C.; Ibrahim, S.R.; Brincker, Rune

    Abstraet Thispaper demansirates how to use the Random Decrement (RD) technique for identification o flinear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing...

  7. Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Ibrahim, S. R.; Brincker, Rune

    This paper demonstrates how to use the Random Decrement (RD) technique for identification of linear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing a new...

  8. Random Decrement

    DEFF Research Database (Denmark)

    Asmussen, J. C.; Ibrahim, R.; Brincker, Rune

    1998-01-01

    This paper demonstrates how to use the Random Decrement (RD) technique for identification of linear structures subjected to ambient excitation. The theory behind the technique will be presented and guidelines how to choose the different variables will be given. This is done by introducing a new...

  9. Random dynamics

    International Nuclear Information System (INIS)

    Bennett, D.L.; Brene, N.; Nielsen, H.B.

    1986-06-01

    The goal of random dynamics is the derivation of the laws of Nature as we know them (standard model) from inessential assumptions. The inessential assumptions made here are expressed as sets of general models at extremely high energies: gauge glass and spacetime foam. Both sets of models lead tentatively to the standard model. (orig.)

  10. Random dynamics

    International Nuclear Information System (INIS)

    Bennett, D.L.

    1987-01-01

    The goal of random dynamics is the derivation of the laws of Nature as we know them (standard model) from inessential assumptions. The inessential assumptions made here are expressed as sets of general models at extremely high energies: Gauge glass and spacetime foam. Both sets of models lead tentatively to the standard model. (orig.)

  11. Random Dynamics

    Science.gov (United States)

    Bennett, D. L.; Brene, N.; Nielsen, H. B.

    1987-01-01

    The goal of random dynamics is the derivation of the laws of Nature as we know them (standard model) from inessential assumptions. The inessential assumptions made here are expressed as sets of general models at extremely high energies: gauge glass and spacetime foam. Both sets of models lead tentatively to the standard model.

  12. Neutron exposure

    International Nuclear Information System (INIS)

    Prillinger, G.; Konynenburg, R.A. van

    1998-01-01

    As a result of the popularity of the Agencies report 'Neutron Irradiation Embrittlement of Reactor Pressure Vessel Steels' of 1975, it was decided that another report on this broad subject would be of use. In this report, background and contemporary views on specially identified areas of the subject are considered as self-contained chapters, written by experts. In chapter 6, LWR-PV neutron transport calculations and dosimetry methods and how they are combined to evaluate the neutron exposure of the steel of pressure vessels are discussed. An effort to correlate neutron exposure parameters with damage is made

  13. Wetting transitions: First order or second order

    International Nuclear Information System (INIS)

    Teletzke, G.F.; Scriven, L.E.; Davis, H.T.

    1982-01-01

    A generalization of Sullivan's recently proposed theory of the equilibrium contact angle, the angle at which a fluid interface meets a solid surface, is investigated. The generalized theory admits either a first-order or second-order transition from a nonzero contact angle to perfect wetting as a critical point is approached, in contrast to Sullivan's original theory, which predicts only a second-order transition. The predictions of this computationally convenient theory are in qualitative agreement with a more rigorous theory to be presented in a future publication

  14. Asbestos Exposure Assessment Database

    Science.gov (United States)

    Arcot, Divya K.

    2010-01-01

    Exposure to particular hazardous materials in a work environment is dangerous to the employees who work directly with or around the materials as well as those who come in contact with them indirectly. In order to maintain a national standard for safe working environments and protect worker health, the Occupational Safety and Health Administration (OSHA) has set forth numerous precautionary regulations. NASA has been proactive in adhering to these regulations by implementing standards which are often stricter than regulation limits and administering frequent health risk assessments. The primary objective of this project is to create the infrastructure for an Asbestos Exposure Assessment Database specific to NASA Johnson Space Center (JSC) which will compile all of the exposure assessment data into a well-organized, navigable format. The data includes Sample Types, Samples Durations, Crafts of those from whom samples were collected, Job Performance Requirements (JPR) numbers, Phased Contrast Microscopy (PCM) and Transmission Electron Microscopy (TEM) results and qualifiers, Personal Protective Equipment (PPE), and names of industrial hygienists who performed the monitoring. This database will allow NASA to provide OSHA with specific information demonstrating that JSC s work procedures are protective enough to minimize the risk of future disease from the exposures. The data has been collected by the NASA contractors Computer Sciences Corporation (CSC) and Wyle Laboratories. The personal exposure samples were collected from devices worn by laborers working at JSC and by building occupants located in asbestos-containing buildings.

  15. Exposure Prophylaxis

    African Journals Online (AJOL)

    opsig

    health care workers who report exposure to HIV at work whether given PEP or not ... breast milk, amniotic fluid, cerebrospinal fluid, pericardial fluid ... or skin lesions [1]. Other body fluid like sweat, tears, saliva, urine and stool do not contain significant quantities of HIV unless there is blood mixed with them[1,2]. HIV is not ...

  16. Characterizations of the random order values by Harsanyi payoff vectors

    NARCIS (Netherlands)

    Derks, J.; van der Laan, G.; Vasil'ev, V.

    2006-01-01

    A Harsanyi payoff vector (see Vasil'ev in Optimizacija Vyp 21:30-35, 1978) of a cooperative game with transferable utilities is obtained by some distribution of the Harsanyi dividends of all coalitions among its members. Examples of Harsanyi payoff vectors are the marginal contribution vectors. The

  17. Ordered particles versus ordered pointers in the hybrid ordered plasma simulation (HOPS) code

    International Nuclear Information System (INIS)

    Anderson, D.V.; Shumaker, D.E.

    1993-01-01

    From a computational standpoint, particle simulation calculations for plasmas have not adapted well to the transitions from scalar to vector processing nor from serial to parallel environments. They have suffered from inordinate and excessive accessing of computer memory and have been hobbled by relatively inefficient gather-scatter constructs resulting from the use of indirect indexing. Lastly, the many-to-one mapping characteristic of the deposition phase has made it difficult to perform this in parallel. The authors' code sorts and reorders the particles in a spatial order. This allows them to greatly reduce the memory references, to run in directly indexed vector mode, and to employ domain decomposition to achieve parallelization. The field model solves pre-maxwell equations by interatively implicit methods. The OSOP (Ordered Storage Ordered Processing) version of HOPS keeps the particle tables ordered by rebuilding them after each particle pushing phase. Alternatively, the RSOP (Random Storage Ordered Processing) version keeps a table of pointers ordered by rebuilding them. Although OSOP is somewhat faster than RSOP in tests on vector-parallel machines, it is not clear this advantage will carry over to massively parallel computers

  18. Random packing of colloids and granular matter

    NARCIS (Netherlands)

    Wouterse, A.

    2008-01-01

    This thesis deals with the random packing of colloids and granular matter. A random packing is a stable disordered collection of touching particles, without long-range positional and orientational order. Experimental random packings of particles with the same shape but made of different materials

  19. Passing the Baton: Community-based ethnography to design a randomized clinical trial on the effectiveness of oral pre-exposure prophylaxis for HIV prevention among Black men who have sex with men

    OpenAIRE

    Garcia, Jonathan; Colson, Paul W.; Parker, Caroline; Hirsch, Jennifer S.

    2015-01-01

    Although HIV interventions and clinical trials increasingly report the use of mixed methods, studies have not reported on the process through which ethnographic or qualitative findings are incorporated into RCT designs. We conducted a community-based ethnography on social and structural factors that may affect the acceptance of and adherence to oral pre-exposure prophylaxis (PrEP) among Black men who have sex with men (BMSM). We then devised the treatment arm of an adherence clinical trial dr...

  20. The mere exposure effect with scene stimuli

    OpenAIRE

    八木 , 善彦

    2016-01-01

     The mere exposure effect refers to the phenomenon where previous exposures to stimuli increasesubsequent affective preference for those stimuli. It has been indicated that with specific stimulus-category(i.e., paintings, matrices, and photographs of scene), repeated exposure has little or oppositeeffect on affective ratings. In this study, two experiments were conducted in order to explore theeffect of stimulus-category on the mere exposure effects. Photographs of young woman’s(Experiment1)a...

  1. Wishful Thinking? Inside the Black Box of Exposure Assessment.

    Science.gov (United States)

    Money, Annemarie; Robinson, Christine; Agius, Raymond; de Vocht, Frank

    2016-05-01

    Decision-making processes used by experts when undertaking occupational exposure assessment are relatively unknown, but it is often assumed that there is a common underlying method that experts employ. However, differences in training and experience of assessors make it unlikely that one general method for expert assessment would exist. Therefore, there are concerns about formalizing, validating, and comparing expert estimates within and between studies that are difficult, if not impossible, to characterize. Heuristics on the other hand (the processes involved in decision making) have been extensively studied. Heuristics are deployed by everyone as short-cuts to make the often complex process of decision-making simpler, quicker, and less burdensome. Experts' assessments are often subject to various simplifying heuristics as a way to reach a decision in the absence of sufficient data. Therefore, investigating the underlying heuristics or decision-making processes involved may help to shed light on the 'black box' of exposure assessment. A mixed method study was conducted utilizing both a web-based exposure assessment exercise incorporating quantitative and semiqualitative elements of data collection, and qualitative semi-structured interviews with exposure assessors. Qualitative data were analyzed using thematic analysis. Twenty-five experts completed the web-based exposure assessment exercise and 8 of these 25 were randomly selected to participate in the follow-up interview. Familiar key themes relating to the exposure assessment exercise emerged; 'intensity'; 'probability'; 'agent'; 'process'; and 'duration' of exposure. However, an important aspect of the detailed follow-up interviews revealed a lack of structure and order with which participants described their decision making. Participants mostly described some form of an iterative process, heavily relying on the anchoring and adjustment heuristic, which differed between experts. In spite of having undertaken

  2. Exposures series

    OpenAIRE

    Stimson, Blake

    2011-01-01

    Reaktion Books’ Exposures series, edited by Peter Hamilton and Mark Haworth-Booth, is comprised of 13 volumes and counting, each less than 200 pages with 80 high-quality illustrations in color and black and white. Currently available titles include Photography and Australia, Photography and Spirit, Photography and Cinema, Photography and Literature, Photography and Flight, Photography and Egypt, Photography and Science, Photography and Africa, Photography and Italy, Photography and the USA, P...

  3. Court orders on procreation.

    Science.gov (United States)

    Matevosyan, Naira R

    2016-01-01

    The aim of this study is to empirically evaluate judgments entered from 1913 to 2013 in the matters of compulsory sterilization. Holdings and dispositions at the U.S. Appellate and Supreme courts are randomly located in LexisNexis using Shepard's symbols. Continuous variables are processed with the Mantel-Haenszel method. Court orders are used as units of analysis. The majority of cases (56.4 %) concern minors at a mean age of 11.7 years. Forty-four (80 %) petitions are filed by the parents or guardians; 11 (20 %) are parens patriae. Petitions for female sterilization are denied in 56.4 % cases under the Federal Laws (2 U.S.C. 431; 28 U.S.C; 29 U.S.C; 42 U.S.C; 424 U.S.), Procedural due process clause of the 14th Amendment, statutes, and common law precedents. Petitions for female sterilization are granted in 36.4 % cases under the statutory penal codes, the Law of the land, precedents, and the dicta. No significant associations are found between the parity and degree of mental impairment (r = 0.342). Substantial correlations are met between the gender, degree of impairment (r (2) = 0.724), and dispositions (r (2) = 802). The mean age of women is 20.78 years; the mean age of men is 30.25 years. Correlations fail to establish reasoning between the age of the subjects and the entered judgments (r (2) = 0. 356). (1) The female/male ratio (8:1) and age gap of the respondents indicate on a disproportionate impact of the statutes. (2) The procedure of sterilization in itself is incommensurate with equality, as the volume of surgery is uneven in males and females. (3) The case law is instructive with respect to which arguments have not been advanced. (4) Lastly, due to the etiological intricacy of mental impairment, with genetic transmission strikingly different in men and women, expert-witnesses ought to act in a medical vacuum because there is no mathematical certainty as to the transmission mode of the traits in question (exon and intron mutations, triplet repeat

  4. On nonlinear reduced order modeling

    International Nuclear Information System (INIS)

    Abdel-Khalik, Hany S.

    2011-01-01

    When applied to a model that receives n input parameters and predicts m output responses, a reduced order model estimates the variations in the m outputs of the original model resulting from variations in its n inputs. While direct execution of the forward model could provide these variations, reduced order modeling plays an indispensable role for most real-world complex models. This follows because the solutions of complex models are expensive in terms of required computational overhead, thus rendering their repeated execution computationally infeasible. To overcome this problem, reduced order modeling determines a relationship (often referred to as a surrogate model) between the input and output variations that is much cheaper to evaluate than the original model. While it is desirable to seek highly accurate surrogates, the computational overhead becomes quickly intractable especially for high dimensional model, n ≫ 10. In this manuscript, we demonstrate a novel reduced order modeling method for building a surrogate model that employs only 'local first-order' derivatives and a new tensor-free expansion to efficiently identify all the important features of the original model to reach a predetermined level of accuracy. This is achieved via a hybrid approach in which local first-order derivatives (i.e., gradient) of a pseudo response (a pseudo response represents a random linear combination of original model’s responses) are randomly sampled utilizing a tensor-free expansion around some reference point, with the resulting gradient information aggregated in a subspace (denoted by the active subspace) of dimension much less than the dimension of the input parameters space. The active subspace is then sampled employing the state-of-the-art techniques for global sampling methods. The proposed method hybridizes the use of global sampling methods for uncertainty quantification and local variational methods for sensitivity analysis. In a similar manner to

  5. Radiation exposure and infant cancer

    Energy Technology Data Exchange (ETDEWEB)

    Watari, T [Tokyo Univ. (Japan). Faculty of Medicine

    1974-12-01

    Medical exposures accompanied by an increase in radiation use in the field of pediatrics were described. Basic ideas and countermeasures to radiation injuries were outlined. In order to decrease the medical exposure, it is necessary for the doctor, x-ray technician and manufacturer to work together. The mechanism and characteristics of radio carcinogenesis were also mentioned. Particularly, the following two points were described: 1) How many years does it take before carcinogenesis appears as a result of radiation exposure in infancy 2) How and when does the effect of fetus exposure appear. Radiosensitivity in infants and fetuses is greater than that of an adult. The occurrence of leukemia caused by prenatal exposure was reviewed. The relation between irradiation for therapy and morbidity of thyroid cancer was mentioned. Finally, precautions necessary for infants, pregnant women and nursing mothers when using radioisotopes were mentioned.

  6. A randomized, multicentre study of directed daylight exposure times of 11/2 vs. 21/2 h in daylight-mediated photodynamic therapy with methyl aminolaevulinate in patients with multiple thin actinic keratoses of the face and scalp

    DEFF Research Database (Denmark)

    Wiegell, S.R.; Fabricius, S.; Philipsen, P.A.

    2011-01-01

    , time of day or time of year during which the treatment was performed. Treatment was well tolerated, with a mean ± SD maximal pain score of 1·3 ± 1·5. Conclusions: Daylight-mediated MAL-PDT is an effective, convenient and nearly pain-free treatment for patients with multiple thin AKs. Daylight-mediated......, the inconvenience of clinic attendance and discomfort during therapy are significant drawbacks. Daylight-mediated PDT could potentially reduce these and may serve as an alternative to conventional PDT. Objectives: To compare the efficacy of methyl aminolaevulinate (MAL)-PDT with 11/2 vs. 21/2 h of daylight exposure...

  7. Staggered chiral random matrix theory

    International Nuclear Information System (INIS)

    Osborn, James C.

    2011-01-01

    We present a random matrix theory for the staggered lattice QCD Dirac operator. The staggered random matrix theory is equivalent to the zero-momentum limit of the staggered chiral Lagrangian and includes all taste breaking terms at their leading order. This is an extension of previous work which only included some of the taste breaking terms. We will also present some results for the taste breaking contributions to the partition function and the Dirac eigenvalues.

  8. First-order inflation

    International Nuclear Information System (INIS)

    Kolb, E.W.

    1991-01-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been reviewed. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result if inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. (orig.)

  9. First-order inflation

    International Nuclear Information System (INIS)

    Kolb, E.W.; Chicago Univ., IL

    1990-09-01

    In the original proposal, inflation occurred in the process of a strongly first-order phase transition. This model was soon demonstrated to be fatally flawed. Subsequent models for inflation involved phase transitions that were second-order, or perhaps weakly first-order; some even involved no phase transition at all. Recently the possibility of inflation during a strongly first-order phase transition has been revived. In this talk I will discuss some models for first-order inflation, and emphasize unique signatures that result in inflation is realized in a first-order transition. Before discussing first-order inflation, I will briefly review some of the history of inflation to demonstrate how first-order inflation differs from other models. 58 refs., 3 figs

  10. Computer generation of random deviates

    International Nuclear Information System (INIS)

    Cormack, John

    1991-01-01

    The need for random deviates arises in many scientific applications. In medical physics, Monte Carlo simulations have been used in radiology, radiation therapy and nuclear medicine. Specific instances include the modelling of x-ray scattering processes and the addition of random noise to images or curves in order to assess the effects of various processing procedures. Reliable sources of random deviates with statistical properties indistinguishable from true random deviates are a fundamental necessity for such tasks. This paper provides a review of computer algorithms which can be used to generate uniform random deviates and other distributions of interest to medical physicists, along with a few caveats relating to various problems and pitfalls which can occur. Source code listings for the generators discussed (in FORTRAN, Turbo-PASCAL and Data General ASSEMBLER) are available on request from the authors. 27 refs., 3 tabs., 5 figs

  11. Random tensors

    CERN Document Server

    Gurau, Razvan

    2017-01-01

    Written by the creator of the modern theory of random tensors, this book is the first self-contained introductory text to this rapidly developing theory. Starting from notions familiar to the average researcher or PhD student in mathematical or theoretical physics, the book presents in detail the theory and its applications to physics. The recent detections of the Higgs boson at the LHC and gravitational waves at LIGO mark new milestones in Physics confirming long standing predictions of Quantum Field Theory and General Relativity. These two experimental results only reinforce today the need to find an underlying common framework of the two: the elusive theory of Quantum Gravity. Over the past thirty years, several alternatives have been proposed as theories of Quantum Gravity, chief among them String Theory. While these theories are yet to be tested experimentally, key lessons have already been learned. Whatever the theory of Quantum Gravity may be, it must incorporate random geometry in one form or another....

  12. Human exposure to nickel

    Energy Technology Data Exchange (ETDEWEB)

    Grandjean, P

    1984-01-01

    In order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. Thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. Occupational exposures may lead to the retention of 100 micrograms of nickel per day. Environmental nickel levels depend particularly on natural sources, pollution from nickel-manufacturing industries and airborne particles from combustion of fossil fuels. Absorption from atmospheric nickel pollution is of minor concern. Vegetables usually contain more nickel than do other food items. Certain products, such as baking powder and cocoa powder, have been found to contain excessive amounts of nickel, perhaps related to nickel leaching during the manufacturing process. Soft drinking-water and acid beverages may dissolve nickel from pipes and containers. Scattered studies indicate a highly variable dietary intake of nickel, but most averages are about 200-300 micrograms/day. In addition, skin contact to a multitude of metal objects may be of significance to the large number of individuals suffering from contact dermatitis and nickel allergy. Finally, nickel alloys are often used in nails and prostheses for orthopaedic surgery, and various sources may contaminate intravenous fluids. Thus, human nickel exposure originates from a variety of sources and is highly variable. Occupational nickel exposure is of major significance, and leaching of nickel may add to dietary intakes and to cutaneous exposures. 79 references.

  13. Bayesian calibration of simultaneity in audiovisual temporal order judgments.

    Directory of Open Access Journals (Sweden)

    Shinya Yamamoto

    Full Text Available After repeated exposures to two successive audiovisual stimuli presented in one frequent order, participants eventually perceive a pair separated by some lag time in the same order as occurring simultaneously (lag adaptation. In contrast, we previously found that perceptual changes occurred in the opposite direction in response to tactile stimuli, conforming to bayesian integration theory (bayesian calibration. We further showed, in theory, that the effect of bayesian calibration cannot be observed when the lag adaptation was fully operational. This led to the hypothesis that bayesian calibration affects judgments regarding the order of audiovisual stimuli, but that this effect is concealed behind the lag adaptation mechanism. In the present study, we showed that lag adaptation is pitch-insensitive using two sounds at 1046 and 1480 Hz. This enabled us to cancel lag adaptation by associating one pitch with sound-first stimuli and the other with light-first stimuli. When we presented each type of stimulus (high- or low-tone in a different block, the point of simultaneity shifted to "sound-first" for the pitch associated with sound-first stimuli, and to "light-first" for the pitch associated with light-first stimuli. These results are consistent with lag adaptation. In contrast, when we delivered each type of stimulus in a randomized order, the point of simultaneity shifted to "light-first" for the pitch associated with sound-first stimuli, and to "sound-first" for the pitch associated with light-first stimuli. The results clearly show that bayesian calibration is pitch-specific and is at work behind pitch-insensitive lag adaptation during temporal order judgment of audiovisual stimuli.

  14. Past exposure

    International Nuclear Information System (INIS)

    Dropkin, G.; Clark, D.

    1992-01-01

    Past Exposure uses confidential company documents, obtained by the Namibia Support Committee over several years, to draw attention to risks to workers' health and the environment at Roessing Uranium mine. Particular reference is made to discussion of dust levels, radiation hazards, uranium poisoning, environmental leaks, especially from the tailings dam, and the lack of monitoring of thorium. In relation to agreements between trades unions and mines, agreements reached by RTZ-owned Canadian in Canada, and British Nuclear Fuels in the UK, are discussed. (UK)

  15. Fast exposure time decision in multi-exposure HDR imaging

    Science.gov (United States)

    Piao, Yongjie; Jin, Guang

    2012-10-01

    Currently available imaging and display system exists the problem of insufficient dynamic range, and the system cannot restore all the information for an high dynamic range (HDR) scene. The number of low dynamic range(LDR) image samples and fastness of exposure time decision impacts the real-time performance of the system dramatically. In order to realize a real-time HDR video acquisition system, this paper proposed a fast and robust method for exposure time selection in under and over exposure area which is based on system response function. The method utilized the monotony of the imaging system. According to this characteristic the exposure time is adjusted to an initial value to make the median value of the image equals to the middle value of the system output range; then adjust the exposure time to make the pixel value on two sides of histogram be the middle value of the system output range. Thus three low dynamic range images are acquired. Experiments show that the proposed method for adjusting the initial exposure time can converge in two iterations which is more fast and stable than average gray control method. As to the exposure time adjusting in under and over exposed area, the proposed method can use the dynamic range of the system more efficiently than fixed exposure time method.

  16. Statistical power in parallel group point exposure studies with time-to-event outcomes: an empirical comparison of the performance of randomized controlled trials and the inverse probability of treatment weighting (IPTW) approach.

    Science.gov (United States)

    Austin, Peter C; Schuster, Tibor; Platt, Robert W

    2015-10-15

    Estimating statistical power is an important component of the design of both randomized controlled trials (RCTs) and observational studies. Methods for estimating statistical power in RCTs have been well described and can be implemented simply. In observational studies, statistical methods must be used to remove the effects of confounding that can occur due to non-random treatment assignment. Inverse probability of treatment weighting (IPTW) using the propensity score is an attractive method for estimating the effects of treatment using observational data. However, sample size and power calculations have not been adequately described for these methods. We used an extensive series of Monte Carlo simulations to compare the statistical power of an IPTW analysis of an observational study with time-to-event outcomes with that of an analysis of a similarly-structured RCT. We examined the impact of four factors on the statistical power function: number of observed events, prevalence of treatment, the marginal hazard ratio, and the strength of the treatment-selection process. We found that, on average, an IPTW analysis had lower statistical power compared to an analysis of a similarly-structured RCT. The difference in statistical power increased as the magnitude of the treatment-selection model increased. The statistical power of an IPTW analysis tended to be lower than the statistical power of a similarly-structured RCT.

  17. Impact of one's own mobile phone in stand-by mode on personal radiofrequency electromagnetic field exposure.

    Science.gov (United States)

    Urbinello, Damiano; Röösli, Martin

    2013-01-01

    When moving around, mobile phones in stand-by mode periodically send data about their positions. The aim of this paper is to evaluate how personal radiofrequency electromagnetic field (RF-EMF) measurements are affected by such location updates. Exposure from a mobile phone handset (uplink) was measured during commuting by using a randomized cross-over study with three different scenarios: disabled mobile phone (reference), an activated dual-band phone and a quad-band phone. In the reference scenario, uplink exposure was highest during train rides (1.19 mW/m(2)) and lowest during car rides in rural areas (0.001 mW/m(2)). In public transports, the impact of one's own mobile phone on personal RF-EMF measurements was not observable because of high background uplink radiation from other people's mobile phone. In a car, uplink exposure with an activated phone was orders of magnitude higher compared with the reference scenario. This study demonstrates that personal RF-EMF exposure is affected by one's own mobile phone in stand-by mode because of its regular location update. Further dosimetric studies should quantify the contribution of location updates to the total RF-EMF exposure in order to clarify whether the duration of mobile phone use, the most common exposure surrogate in the epidemiological RF-EMF research, is actually an adequate exposure proxy.

  18. Alzheimer random walk

    Science.gov (United States)

    Odagaki, Takashi; Kasuya, Keisuke

    2017-09-01

    Using the Monte Carlo simulation, we investigate a memory-impaired self-avoiding walk on a square lattice in which a random walker marks each of sites visited with a given probability p and makes a random walk avoiding the marked sites. Namely, p = 0 and p = 1 correspond to the simple random walk and the self-avoiding walk, respectively. When p> 0, there is a finite probability that the walker is trapped. We show that the trap time distribution can well be fitted by Stacy's Weibull distribution b(a/b){a+1}/{b}[Γ({a+1}/{b})]-1x^a\\exp(-a/bx^b)} where a and b are fitting parameters depending on p. We also find that the mean trap time diverges at p = 0 as p- α with α = 1.89. In order to produce sufficient number of long walks, we exploit the pivot algorithm and obtain the mean square displacement and its Flory exponent ν(p) as functions of p. We find that the exponent determined for 1000 step walks interpolates both limits ν(0) for the simple random walk and ν(1) for the self-avoiding walk as [ ν(p) - ν(0) ] / [ ν(1) - ν(0) ] = pβ with β = 0.388 when p ≪ 0.1 and β = 0.0822 when p ≫ 0.1. Contribution to the Topical Issue "Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  19. Work Tasks as Determinants of Grain Dust and Microbial Exposure in the Norwegian Grain and Compound Feed Industry.

    Science.gov (United States)

    Straumfors, Anne; Heldal, Kari Kulvik; Wouters, Inge M; Eduard, Wijnand

    2015-07-01

    The grain and compound feed industry entails inevitable risks of exposure to grain dust and its microbial content. The objective of this study was therefore to investigate task-dependent exposure differences in order to create knowledge basis for awareness and exposure reducing measures in the Norwegian grain and compound feed industry. A total of 166 samples of airborne dust were collected by full-shift personal sampling during work in 20 grain elevators and compound feed mills during one autumn season and two winter seasons. The personal exposure to grain dust, endotoxins, β-1→3-glucans, bacteria, and fungal spores was quantified and used as individual outcomes in mixed models with worker nested in company as random effect and different departments and tasks as fixed effects. The exposure levels were highest in grain elevator departments. Exposure to endotoxins was particularly high. Tasks that represented the highest and lowest exposures varied depending on the bioaerosol component. The most important determinants for elevated dust exposure were cleaning and process controlling. Cleaning increased the dust exposure level by a factor of 2.44 of the reference, from 0.65 to 1.58mg m(-3), whereas process controlling increased the dust exposure level by a factor of 2.97, from 0.65 to 1.93mg m(-3). Process controlling was associated with significantly less grain dust exposure in compound feed mills and the combined grain elevators and compound feed mills, than in grain elevators. The exposure was reduced by a factor of 0.18 and 0.22, from 1.93 to 0.34mg m(-3) and to 0.42mg m(-3), respectively, compared with the grain elevators. Inspection/maintenance, cleaning, and grain rotation and emptying were determinants of higher exposure to both endotoxin and β-1→3-glucans. Seed winnowing was in addition a strong determinant for endotoxin, whereas mixing of animal feed implied higher β-1→3-glucan exposure. Cleaning was the only task that contributed significantly to

  20. Eczema, birth order, and infection.

    Science.gov (United States)

    Hughes, Ann Maree; Crouch, Simon; Lightfoot, Tracy; Ansell, Pat; Simpson, Jill; Roman, Eve

    2008-05-15

    The association between infections occurring in the first 2 years of life and development of eczema was investigated in 1,782 control children from a national population-based case-control study in the United Kingdom conducted over the period 1991-1996. Dates of eczema and infectious diagnoses were ascertained from contemporaneously collected primary care records. Children diagnosed with eczema before the age of 2 years had more prior clinically diagnosed infections recorded than did children without eczema (rate ratio = 1.26, 95% confidence interval (CI): 1.18, 1.36). The difference in infection rates between children with and without eczema was apparent from birth and throughout the first 2 years of life. As expected, compared with children of second or higher birth order, those firstborn were at increased risk of eczema (p = 0.020); however, the relation between eczema and prior infection was evident only among children of second or higher birth order and not among firstborn children (rate ratio = 1.45, 95% CI: 1.32, 1.59, and rate ratio = 1.08, 95% CI: 0.98, 1.20, respectively). The authors' results are consistent with the notion that the association between birth order and eczema is unlikely to be attributable to variations in early infectious exposure.

  1. Fractional-order devices

    CERN Document Server

    Biswas, Karabi; Caponetto, Riccardo; Mendes Lopes, António; Tenreiro Machado, José António

    2017-01-01

    This book focuses on two specific areas related to fractional order systems – the realization of physical devices characterized by non-integer order impedance, usually called fractional-order elements (FOEs); and the characterization of vegetable tissues via electrical impedance spectroscopy (EIS) – and provides readers with new tools for designing new types of integrated circuits. The majority of the book addresses FOEs. The interest in these topics is related to the need to produce “analogue” electronic devices characterized by non-integer order impedance, and to the characterization of natural phenomena, which are systems with memory or aftereffects and for which the fractional-order calculus tool is the ideal choice for analysis. FOEs represent the building blocks for designing and realizing analogue integrated electronic circuits, which the authors believe hold the potential for a wealth of mass-market applications. The freedom to choose either an integer- or non-integer-order analogue integrator...

  2. Order Management - Today's focus

    DEFF Research Database (Denmark)

    Barfod, Ari

    1996-01-01

    Small and mid-range companies throughout the world have moved towards customer-specific production during the last few years, but often, the order flow has not changed to meet new demands. Customer orders pass through a laarge number of departments, such as sales, construction, pre...... to the final product.In the paper, a new method for improving order flow is presented, including an extended use of activity chain models....

  3. Color ordering in QCD

    OpenAIRE

    Schuster, Theodor

    2013-01-01

    We derive color decompositions of arbitrary tree and one-loop QCD amplitudes into color ordered objects called primitive amplitudes. Furthermore, we derive general fermion flip and reversion identities spanning the null space among the primitive amplitudes and use them to prove that all color ordered tree amplitudes of massless QCD can be written as linear combinations of color ordered tree amplitudes of $\\mathcal{N}=4$ super Yang-Mills theory.

  4. Protein domain organisation: adding order

    Directory of Open Access Journals (Sweden)

    Kummerfeld Sarah K

    2009-01-01

    degree of clustering and more domain pairs in forward and reverse orientation in different proteins relative to random graphs with identical degree distributions. While these features were statistically over-represented, they are still fairly rare. Looking in detail at the proteins involved, we found strong functional relationships within each cluster. In addition, the domains tended to be involved in protein-protein interaction and are able to function as independent structural units. A particularly striking example was the human Jak-STAT signalling pathway which makes use of a set of domains in a range of orders and orientations to provide nuanced signaling functionality. This illustrated the importance of functional and structural constraints (or lack thereof on domain organisation.

  5. Protein domain organisation: adding order.

    Science.gov (United States)

    Kummerfeld, Sarah K; Teichmann, Sarah A

    2009-01-29

    reverse orientation in different proteins relative to random graphs with identical degree distributions. While these features were statistically over-represented, they are still fairly rare. Looking in detail at the proteins involved, we found strong functional relationships within each cluster. In addition, the domains tended to be involved in protein-protein interaction and are able to function as independent structural units. A particularly striking example was the human Jak-STAT signalling pathway which makes use of a set of domains in a range of orders and orientations to provide nuanced signaling functionality. This illustrated the importance of functional and structural constraints (or lack thereof) on domain organisation.

  6. Random pulse generator

    International Nuclear Information System (INIS)

    Guo Ya'nan; Jin Dapeng; Zhao Dixin; Liu Zhen'an; Qiao Qiao; Chinese Academy of Sciences, Beijing

    2007-01-01

    Due to the randomness of radioactive decay and nuclear reaction, the signals from detectors are random in time. But normal pulse generator generates periodical pulses. To measure the performances of nuclear electronic devices under random inputs, a random generator is necessary. Types of random pulse generator are reviewed, 2 digital random pulse generators are introduced. (authors)

  7. Random matrices and random difference equations

    International Nuclear Information System (INIS)

    Uppuluri, V.R.R.

    1975-01-01

    Mathematical models leading to products of random matrices and random difference equations are discussed. A one-compartment model with random behavior is introduced, and it is shown how the average concentration in the discrete time model converges to the exponential function. This is of relevance to understanding how radioactivity gets trapped in bone structure in blood--bone systems. The ideas are then generalized to two-compartment models and mammillary systems, where products of random matrices appear in a natural way. The appearance of products of random matrices in applications in demography and control theory is considered. Then random sequences motivated from the following problems are studied: constant pulsing and random decay models, random pulsing and constant decay models, and random pulsing and random decay models

  8. Toward a Principled Sampling Theory for Quasi-Orders.

    Science.gov (United States)

    Ünlü, Ali; Schrepp, Martin

    2016-01-01

    Quasi-orders, that is, reflexive and transitive binary relations, have numerous applications. In educational theories, the dependencies of mastery among the problems of a test can be modeled by quasi-orders. Methods such as item tree or Boolean analysis that mine for quasi-orders in empirical data are sensitive to the underlying quasi-order structure. These data mining techniques have to be compared based on extensive simulation studies, with unbiased samples of randomly generated quasi-orders at their basis. In this paper, we develop techniques that can provide the required quasi-order samples. We introduce a discrete doubly inductive procedure for incrementally constructing the set of all quasi-orders on a finite item set. A randomization of this deterministic procedure allows us to generate representative samples of random quasi-orders. With an outer level inductive algorithm, we consider the uniform random extensions of the trace quasi-orders to higher dimension. This is combined with an inner level inductive algorithm to correct the extensions that violate the transitivity property. The inner level correction step entails sampling biases. We propose three algorithms for bias correction and investigate them in simulation. It is evident that, on even up to 50 items, the new algorithms create close to representative quasi-order samples within acceptable computing time. Hence, the principled approach is a significant improvement to existing methods that are used to draw quasi-orders uniformly at random but cannot cope with reasonably large item sets.

  9. Toward a Principled Sampling Theory for Quasi-Orders

    Science.gov (United States)

    Ünlü, Ali; Schrepp, Martin

    2016-01-01

    Quasi-orders, that is, reflexive and transitive binary relations, have numerous applications. In educational theories, the dependencies of mastery among the problems of a test can be modeled by quasi-orders. Methods such as item tree or Boolean analysis that mine for quasi-orders in empirical data are sensitive to the underlying quasi-order structure. These data mining techniques have to be compared based on extensive simulation studies, with unbiased samples of randomly generated quasi-orders at their basis. In this paper, we develop techniques that can provide the required quasi-order samples. We introduce a discrete doubly inductive procedure for incrementally constructing the set of all quasi-orders on a finite item set. A randomization of this deterministic procedure allows us to generate representative samples of random quasi-orders. With an outer level inductive algorithm, we consider the uniform random extensions of the trace quasi-orders to higher dimension. This is combined with an inner level inductive algorithm to correct the extensions that violate the transitivity property. The inner level correction step entails sampling biases. We propose three algorithms for bias correction and investigate them in simulation. It is evident that, on even up to 50 items, the new algorithms create close to representative quasi-order samples within acceptable computing time. Hence, the principled approach is a significant improvement to existing methods that are used to draw quasi-orders uniformly at random but cannot cope with reasonably large item sets. PMID:27965601

  10. Self-correcting random number generator

    Science.gov (United States)

    Humble, Travis S.; Pooser, Raphael C.

    2016-09-06

    A system and method for generating random numbers. The system may include a random number generator (RNG), such as a quantum random number generator (QRNG) configured to self-correct or adapt in order to substantially achieve randomness from the output of the RNG. By adapting, the RNG may generate a random number that may be considered random regardless of whether the random number itself is tested as such. As an example, the RNG may include components to monitor one or more characteristics of the RNG during operation, and may use the monitored characteristics as a basis for adapting, or self-correcting, to provide a random number according to one or more performance criteria.

  11. Order in Chaos

    DEFF Research Database (Denmark)

    Hansen, Bertel Teilfeldt; Olsen, Asmus Leth

    2014-01-01

    Ballot order effects are well documented in established democracies, but less so in fragile post-conflict settings. We test for the presence of ballot order effects in the 2010 parliamentary election in Afghanistan. Turning out for the 2010 election was a potentially life-threatening endeavor for...

  12. Survivor bias in Mendelian randomization analysis

    DEFF Research Database (Denmark)

    Vansteelandt, Stijn; Dukes, Oliver; Martinussen, Torben

    2017-01-01

    Mendelian randomization studies employ genotypes as experimental handles to infer the effect of genetically modified exposures (e.g. vitamin D exposure) on disease outcomes (e.g. mortality). The statistical analysis of these studies makes use of the standard instrumental variables framework. Many...... of these studies focus on elderly populations, thereby ignoring the problem of left truncation, which arises due to the selection of study participants being conditional upon surviving up to the time of study onset. Such selection, in general, invalidates the assumptions on which the instrumental variables...... analysis rests. We show that Mendelian randomization studies of adult or elderly populations will therefore, in general, return biased estimates of the exposure effect when the considered genotype affects mortality; in contrast, standard tests of the causal null hypothesis that the exposure does not affect...

  13. Tailored Random Graph Ensembles

    International Nuclear Information System (INIS)

    Roberts, E S; Annibale, A; Coolen, A C C

    2013-01-01

    Tailored graph ensembles are a developing bridge between biological networks and statistical mechanics. The aim is to use this concept to generate a suite of rigorous tools that can be used to quantify and compare the topology of cellular signalling networks, such as protein-protein interaction networks and gene regulation networks. We calculate exact and explicit formulae for the leading orders in the system size of the Shannon entropies of random graph ensembles constrained with degree distribution and degree-degree correlation. We also construct an ergodic detailed balance Markov chain with non-trivial acceptance probabilities which converges to a strictly uniform measure and is based on edge swaps that conserve all degrees. The acceptance probabilities can be generalized to define Markov chains that target any alternative desired measure on the space of directed or undirected graphs, in order to generate graphs with more sophisticated topological features.

  14. Put order picking system

    Directory of Open Access Journals (Sweden)

    Đurđević Dragan D.

    2014-01-01

    Full Text Available Nowadays the warehouse is very important logistic component of the supply chain, where order-picking systems have important role. Due to the significant impact on logistics performance permanent goals are to increase efficiency and reduce the cost of these systems. To achieve these goals, there are different researches, and their success is determined by the achieved performances. Performances order picking process are dependent on the applied technology concepts of order-picking system, as well as the ways in which it is organized and managed. In addition to the standard conceptions (the man to good and good to the man is one of the newer, so-called. 'put' system - the inverse order-picking. The aim of this paper is to describe this concept, point out its core strengths and weaknesses and provide a basis that may be of importance in the development of warehouse technological solutions and application of this order-picking systems concept.

  15. Narcissism and birth order.

    Science.gov (United States)

    Eyring, W E; Sobelman, S

    1996-04-01

    The purpose of this investigation was to clarify the relationship between birth-order position and the development of narcissism, while refining research and theory. The relationship between birth-order status and narcissism was examined with a sample of 79 undergraduate students (55 women and 24 men). These subjects were placed in one of the four following birth-order categories of firstborn, second-born, last-born, and only children. These categories were chosen given their significance in Adlerian theory. Each subject completed the Narcissistic Personality Inventory and a demographic inventory. Based on psychodynamic theory, it was hypothesized that firstborn children were expected to score highest, but statistical significance was not found for an association between narcissism and birth order. Further research is urged to investigate personality theory as it relates to parenting style and birth order.

  16. Effectiveness of cognitive behavioral therapy integrated with systematic desensitization, cognitive behavioral therapy combined with eye movement desensitization and reprocessing therapy, and cognitive behavioral therapy combined with virtual reality exposure therapy methods in the treatment of flight anxiety: a randomized trial.

    Science.gov (United States)

    Triscari, Maria Teresa; Faraci, Palmira; Catalisano, Dario; D'Angelo, Valerio; Urso, Viviana

    2015-01-01

    The purpose of the research was to compare the effectiveness of the following treatment methods for fear of flying: cognitive behavioral therapy (CBT) integrated with systematic desensitization, CBT combined with eye movement desensitization and reprocessing therapy, and CBT combined with virtual reality exposure therapy. Overall, our findings have proven the efficacy of all interventions in reducing fear of flying in a pre- to post-treatment comparison. All groups showed a decrease in flight anxiety, suggesting the efficiency of all three treatments in reducing self-report measures of fear of flying. In particular, our results indicated significant improvements for the treated patients using all the treatment programs, as shown not only by test scores but also by participation in the post-treatment flight. Nevertheless, outcome measures maintained a significant effect at a 1-year follow-up. In conclusion, combining CBT with both the application of eye movement desensitization and reprocessing treatment and the virtual stimuli used to expose patients with aerophobia seemed as efficient as traditional cognitive behavioral treatments integrated with systematic desensitization.

  17. Passing the baton: Community-based ethnography to design a randomized clinical trial on the effectiveness of oral pre-exposure prophylaxis for HIV prevention among Black men who have sex with men.

    Science.gov (United States)

    Garcia, Jonathan; Colson, Paul W; Parker, Caroline; Hirsch, Jennifer S

    2015-11-01

    Although HIV interventions and clinical trials increasingly report the use of mixed methods, studies have not reported on the process through which ethnographic or qualitative findings are incorporated into RCT designs. We conducted a community-based ethnography on social and structural factors that may affect the acceptance of and adherence to oral pre-exposure prophylaxis (PrEP) among Black men who have sex with men (BMSM). We then devised the treatment arm of an adherence clinical trial drawing on findings from the community-based ethnography. This article describes how ethnographic findings informed the RCT and identifies distilled themes and findings that could be included as part of an RCT. The enhanced intervention includes in-person support groups, online support groups, peer navigation, and text message reminders. By describing key process-related facilitators and barriers to conducting meaningful mixed methods research, we provide important insights for the practice of designing clinical trials for 'real-world' community settings. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. A paediatric X-ray exposure chart

    Energy Technology Data Exchange (ETDEWEB)

    Knight, Stephen P, E-mail: stephen.knight@health.qld.gov.au [Department of Medical Imaging, Royal Children' s Hospital, Brisbane, Queensland (Australia)

    2014-09-15

    The aim of this review was to develop a radiographic optimisation strategy to make use of digital radiography (DR) and needle phosphor computerised radiography (CR) detectors, in order to lower radiation dose and improve image quality for paediatrics. This review was based on evidence-based practice, of which a component was a review of the relevant literature. The resulting exposure chart was developed with two distinct groups of exposure optimisation strategies – body exposures (for head, trunk, humerus, femur) and distal extremity exposures (elbow to finger, knee to toe). Exposure variables manipulated included kilovoltage peak (kVp), target detector exposure and milli-ampere-seconds (mAs), automatic exposure control (AEC), additional beam filtration, and use of antiscatter grid. Mean dose area product (DAP) reductions of up to 83% for anterior–posterior (AP)/posterior–anterior (PA) abdomen projections were recorded postoptimisation due to manipulation of multiple-exposure variables. For body exposures, the target EI and detector exposure, and thus the required mAs were typically 20% less postoptimisation. Image quality for some distal extremity exposures was improved by lowering kVp and increasing mAs around constant entrance skin dose. It is recommended that purchasing digital X-ray equipment with high detective quantum efficiency detectors, and then optimising the exposure chart for use with these detectors is of high importance for sites performing paediatric imaging. Multiple-exposure variables may need to be manipulated to achieve optimal outcomes.

  19. Random distributed feedback fibre lasers

    Energy Technology Data Exchange (ETDEWEB)

    Turitsyn, Sergei K., E-mail: s.k.turitsyn@aston.ac.uk [Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET (United Kingdom); Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Babin, Sergey A. [Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation); Churkin, Dmitry V. [Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET (United Kingdom); Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation); Vatnik, Ilya D.; Nikulin, Maxim [Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation); Podivilov, Evgenii V. [Novosibirsk State University, 2 Pirogova str., 630090, Novosibirsk (Russian Federation); Institute of Automation and Electrometry SB RAS, 1 Ac. Koptug. ave., 630090, Novosibirsk (Russian Federation)

    2014-09-10

    The concept of random lasers exploiting multiple scattering of photons in an amplifying disordered medium in order to generate coherent light without a traditional laser resonator has attracted a great deal of attention in recent years. This research area lies at the interface of the fundamental theory of disordered systems and laser science. The idea was originally proposed in the context of astrophysics in the 1960s by V.S. Letokhov, who studied scattering with “negative absorption” of the interstellar molecular clouds. Research on random lasers has since developed into a mature experimental and theoretical field. A simple design of such lasers would be promising for potential applications. However, in traditional random lasers the properties of the output radiation are typically characterized by complex features in the spatial, spectral and time domains, making them less attractive than standard laser systems in terms of practical applications. Recently, an interesting and novel type of one-dimensional random laser that operates in a conventional telecommunication fibre without any pre-designed resonator mirrors–random distributed feedback fibre laser–was demonstrated. The positive feedback required for laser generation in random fibre lasers is provided by the Rayleigh scattering from the inhomogeneities of the refractive index that are naturally present in silica glass. In the proposed laser concept, the randomly backscattered light is amplified through the Raman effect, providing distributed gain over distances up to 100 km. Although an effective reflection due to the Rayleigh scattering is extremely small (∼0.1%), the lasing threshold may be exceeded when a sufficiently large distributed Raman gain is provided. Such a random distributed feedback fibre laser has a number of interesting and attractive features. The fibre waveguide geometry provides transverse confinement, and effectively one-dimensional random distributed feedback leads to the

  20. Random distributed feedback fibre lasers

    International Nuclear Information System (INIS)

    Turitsyn, Sergei K.; Babin, Sergey A.; Churkin, Dmitry V.; Vatnik, Ilya D.; Nikulin, Maxim; Podivilov, Evgenii V.

    2014-01-01

    The concept of random lasers exploiting multiple scattering of photons in an amplifying disordered medium in order to generate coherent light without a traditional laser resonator has attracted a great deal of attention in recent years. This research area lies at the interface of the fundamental theory of disordered systems and laser science. The idea was originally proposed in the context of astrophysics in the 1960s by V.S. Letokhov, who studied scattering with “negative absorption” of the interstellar molecular clouds. Research on random lasers has since developed into a mature experimental and theoretical field. A simple design of such lasers would be promising for potential applications. However, in traditional random lasers the properties of the output radiation are typically characterized by complex features in the spatial, spectral and time domains, making them less attractive than standard laser systems in terms of practical applications. Recently, an interesting and novel type of one-dimensional random laser that operates in a conventional telecommunication fibre without any pre-designed resonator mirrors–random distributed feedback fibre laser–was demonstrated. The positive feedback required for laser generation in random fibre lasers is provided by the Rayleigh scattering from the inhomogeneities of the refractive index that are naturally present in silica glass. In the proposed laser concept, the randomly backscattered light is amplified through the Raman effect, providing distributed gain over distances up to 100 km. Although an effective reflection due to the Rayleigh scattering is extremely small (∼0.1%), the lasing threshold may be exceeded when a sufficiently large distributed Raman gain is provided. Such a random distributed feedback fibre laser has a number of interesting and attractive features. The fibre waveguide geometry provides transverse confinement, and effectively one-dimensional random distributed feedback leads to the

  1. Order of blood draw

    DEFF Research Database (Denmark)

    Cornes, Michael; van Dongen-Lases, Edmée; Grankvist, Kjell

    2017-01-01

    does occur if order of draw is not followed during blood collection and when performing venipuncture under less than ideal circumstances, thus putting patient safety at risk. Moreover, given that order of draw is not difficult to follow and knowing that ideal phlebotomy conditions and protocols...... Medicine Working Group for the Preanalytical Phase (EFLM WG-PRE) provides an overview and summary of the literature with regards to order of draw in venous blood collection. Given the evidence presented in this article, the EFLM WG-PRE herein concludes that a significant frequency of sample contamination...

  2. Mathematics of aperiodic order

    CERN Document Server

    Lenz, Daniel; Savinien, Jean

    2015-01-01

    What is order that is not based on simple repetition, that is, periodicity? How must atoms be arranged in a material so that it diffracts like a quasicrystal? How can we describe aperiodically ordered systems mathematically? Originally triggered by the – later Nobel prize-winning – discovery of quasicrystals, the investigation of aperiodic order has since become a well-established and rapidly evolving field of mathematical research with close ties to a surprising variety of branches of mathematics and physics. This book offers an overview of the state of the art in the field of aperiodic order, presented in carefully selected authoritative surveys. It is intended for non-experts with a general background in mathematics, theoretical physics or computer science, and offers a highly accessible source of first-hand information for all those interested in this rich and exciting field. Topics covered include the mathematical theory of diffraction, the dynamical systems of tilings or Delone sets, their cohomolog...

  3. Order-Disorder Theory

    International Nuclear Information System (INIS)

    Kasteleyn, P.W.

    1971-01-01

    Apology. 1. Order-disorder transitions; 2. The Ising model; 3. The classical theories; 4. The exact analysis of the Ising model; 5. Series expansions; 6. Relations between critical indices; 7. Other models; 8. Concluding remarks. (author)

  4. Ordered groups and topology

    CERN Document Server

    Clay, Adam

    2016-01-01

    This book deals with the connections between topology and ordered groups. It begins with a self-contained introduction to orderable groups and from there explores the interactions between orderability and objects in low-dimensional topology, such as knot theory, braid groups, and 3-manifolds, as well as groups of homeomorphisms and other topological structures. The book also addresses recent applications of orderability in the studies of codimension-one foliations and Heegaard-Floer homology. The use of topological methods in proving algebraic results is another feature of the book. The book was written to serve both as a textbook for graduate students, containing many exercises, and as a reference for researchers in topology, algebra, and dynamical systems. A basic background in group theory and topology is the only prerequisite for the reader.

  5. Topics in random walks in random environment

    International Nuclear Information System (INIS)

    Sznitman, A.-S.

    2004-01-01

    Over the last twenty-five years random motions in random media have been intensively investigated and some new general methods and paradigms have by now emerged. Random walks in random environment constitute one of the canonical models of the field. However in dimension bigger than one they are still poorly understood and many of the basic issues remain to this day unresolved. The present series of lectures attempt to give an account of the progresses which have been made over the last few years, especially in the study of multi-dimensional random walks in random environment with ballistic behavior. (author)

  6. Mobile food ordering application

    OpenAIRE

    Yang, Fan

    2014-01-01

    The purpose of this thesis was to build a food ordering client server application for Tom Yum Thai Oy, which is a Thai restaurant in Vaasa. For the customer, this application provides a view of current food information (category, name, image,price, description etc.) on the website and Android application. The customer can order food from these two platforms. For the administrator in restaurant, this application offers a series of operations to add, update, delete and query the information of ...

  7. Operator ordering and causality

    OpenAIRE

    Plimak, L. I.; Stenholm, S. T.

    2011-01-01

    It is shown that causality violations [M. de Haan, Physica 132A, 375, 397 (1985)], emerging when the conventional definition of the time-normal operator ordering [P.L.Kelley and W.H.Kleiner, Phys.Rev. 136, A316 (1964)] is taken outside the rotating wave approximation, disappear when the amended definition [L.P. and S.S., Annals of Physics, 323, 1989 (2008)] of this ordering is used.

  8. A prospective, randomized, fellow eye comparison of WaveLight® Allegretto Wave® Eye-Q versus VISX CustomVue™ STAR S4 IR™ in laser in situ keratomileusis (LASIK: analysis of visual outcomes and higher order aberrations

    Directory of Open Access Journals (Sweden)

    Moshirfar M

    2011-09-01

    Full Text Available Majid Moshirfar1, Brent S Betts2, Daniel S Churgin3, Maylon Hsu1, Marcus Neuffer1, Shameema Sikder4, Dane Church5, Mark D Mifflin11John A Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, UT, USA; 2Temple University School of Medicine, Philadelphia, PA, USA; 3University of Arizona College of Medicine – Phoenix, Phoenix, AZ, USA; 4Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA; 5Virginia Commonwealth University School of Medicine, Richmond, VA, USAPurpose: To compare outcomes in visual acuity, refractive error, higher-order aberrations (HOAs, contrast sensitivity, and dry eye in patients undergoing laser in situ keratomileusis (LASIK using wavefront (WF guided VISX CustomVue and WF optimized WaveLight Allegretto platforms.Methods: In this randomized, prospective, single-masked, fellow eye study, LASIK was performed on 44 eyes (22 patients, with one eye randomized to WaveLight Allegretto, and the fellow eye receiving VISX CustomVue. Postoperative outcome measures at 3 months included uncorrected distance visual acuity (UDVA, corrected distance visual acuity (CDVA, refractive error, root-mean-square (RMS value of total and grouped HOAs, contrast sensitivity, and Schirmers testing.Results: Mean values for UDVA (logMAR were -0.067 ± 0.087 and -0.073 ± 0.092 in the WF optimized and WF guided groups, respectively (P = 0.909. UDVA of 20/20 or better was achieved in 91% of eyes undergoing LASIK with both lasers while UDVA of 20/15 or better was achieved in 64% of eyes using the Allegretto platform, and 59% of eyes using VISX CustomVue (P = 1.000. In the WF optimized group, total HOA increased 4% (P = 0.012, coma increased 11% (P = 0.065, and spherical aberration increased 19% (P = 0.214, while trefoil decreased 5% (P = 0.490. In the WF guided group, total HOA RMS decreased 9% (P = 0.126, coma decreased 18% (P = 0.144, spherical aberration decreased 27% (P = 0.713 and trefoil

  9. On the limit distribution of lower extreme generalized order statistics

    Indian Academy of Sciences (India)

    Abstract. In a wide subclass of generalized order statistics (gOs), which contains most of the known and important models of ordered random variables, weak conver- gence of lower extremes are developed. A recent result of extreme value theory of m−gOs (as well as the classical extreme value theory of ordinary order ...

  10. On the Limit Distribution of Lower Extreme Generalized Order Statistics

    Indian Academy of Sciences (India)

    In a wide subclass of generalized order statistics ( g O s ) , which contains most of the known and important models of ordered random variables, weak convergence of lower extremes are developed. A recent result of extreme value theory of m − g O s (as well as the classical extreme value theory of ordinary order statistics) ...

  11. A randomized, placebo-controlled, four-period crossover, definitive QT study of the effects of APF530 exposure, high-dose intravenous granisetron, and moxifloxacin on QTc prolongation

    International Nuclear Information System (INIS)

    Mason, Jay W; Moon, Thomas E; O’Boyle, Erin; Dietz, Albert

    2014-01-01

    Regulatory concern about potential QT-interval prolongation by serotonin-receptor antagonist antiemetics prompted product-label changes. The first-generation serotonin-receptor antagonist granisetron is available in oral (PO), intravenous (IV), and transdermal formulations. APF530 is a formulation that provides sustained release of granisetron when administered as a single subcutaneous (SC) injection. The Phase I study reported here evaluated effects of APF530 on electrocardiographic intervals. This single-site, double-blind, placebo-controlled, four-period crossover trial randomized healthy men and women to receive varying sequences of APF530 1 g SC, granisetron 50 μg/kg IV, moxifloxacin 400 mg PO, and placebo. Subjects were assessed for 49 hours after each treatment. The primary objective was to evaluate differences between baseline-adjusted, heart rate-corrected QT-interval change using the Fridericia rate correction (dQTcF) for APF530 1 g SC and placebo. Electrocardiograms were performed at various times throughout the assessment period. Pharmacokinetics and safety were evaluated. The upper one-sided 95% confidence interval (CI) for mean baseline-adjusted dQTcF at each post-dose time point between APF530 and placebo excluded 10 ms, indicating that APF530 1 g SC had no clinically significant effect on QTcF. Maximum observed QTcF change was 4.15 ms (90% CI, 0.94 to 7.36) at Hour 3. No clinically significant changes in other electrocardiogram intervals were observed. APF530 SC pharmacokinetics were as expected, with slow absorption (maximum plasma concentration 35.8 ng/mL, median time to maximum plasma concentration 11.1 hours) and slow elimination (mean half-life 18.6 hours; systemic clearance 20.2 L/hour) of granisetron versus the expected early peak concentration and elimination of granisetron IV. APF530 SC was well tolerated. Adverse events, most commonly constipation and SC injection-site reactions, were generally mild and quickly resolved. APF530 1 g SC did

  12. A randomized, placebo-controlled, four-period crossover, definitive QT study of the effects of APF530 exposure, high-dose intravenous granisetron, and moxifloxacin on QTc prolongation

    Directory of Open Access Journals (Sweden)

    Mason JW

    2014-03-01

    Full Text Available Jay W Mason,1 Thomas E Moon,2 Erin O’Boyle,3 Albert Dietz41Department of Medicine, University of Utah, Salt Lake City, UT, 2Tarizona eHealth Services, Inc., San Carlos, CA, 3AP Pharma, Redwood City, CA, 4Spaulding Clinical Research, West Bend, WI, USABackground: Regulatory concern about potential QT-interval prolongation by serotonin-receptor antagonist antiemetics prompted product-label changes. The first-generation serotonin-receptor antagonist granisetron is available in oral (PO, intravenous (IV, and transdermal formulations. APF530 is a formulation that provides sustained release of granisetron when administered as a single subcutaneous (SC injection. The Phase I study reported here evaluated effects of APF530 on electrocardiographic intervals.Methods: This single-site, double-blind, placebo-controlled, four-period crossover trial randomized healthy men and women to receive varying sequences of APF530 1 g SC, granisetron 50 μg/kg IV, moxifloxacin 400 mg PO, and placebo. Subjects were assessed for 49 hours after each treatment. The primary objective was to evaluate differences between baseline-adjusted, heart rate-corrected QT-interval change using the Fridericia rate correction (dQTcF for APF530 1 g SC and placebo. Electrocardiograms were performed at various times throughout the assessment period. Pharmacokinetics and safety were evaluated.Results: The upper one-sided 95% confidence interval (CI for mean baseline-adjusted dQTcF at each post-dose time point between APF530 and placebo excluded 10 ms, indicating that APF530 1 g SC had no clinically significant effect on QTcF. Maximum observed QTcF change was 4.15 ms (90% CI, 0.94 to 7.36 at Hour 3. No clinically significant changes in other electrocardiogram intervals were observed. APF530 SC pharmacokinetics were as expected, with slow absorption (maximum plasma concentration 35.8 ng/mL, median time to maximum plasma concentration 11.1 hours and slow elimination (mean half-life 18.6 hours

  13. ORDERED WEIGHTED DISTANCE MEASURE

    Institute of Scientific and Technical Information of China (English)

    Zeshui XU; Jian CHEN

    2008-01-01

    The aim of this paper is to develop an ordered weighted distance (OWD) measure, which is thegeneralization of some widely used distance measures, including the normalized Hamming distance, the normalized Euclidean distance, the normalized geometric distance, the max distance, the median distance and the min distance, etc. Moreover, the ordered weighted averaging operator, the generalized ordered weighted aggregation operator, the ordered weighted geometric operator, the averaging operator, the geometric mean operator, the ordered weighted square root operator, the square root operator, the max operator, the median operator and the min operator axe also the special cases of the OWD measure. Some methods depending on the input arguments are given to determine the weights associated with the OWD measure. The prominent characteristic of the OWD measure is that it can relieve (or intensify) the influence of unduly large or unduly small deviations on the aggregation results by assigning them low (or high) weights. This desirable characteristic makes the OWD measure very suitable to be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. Finally, based on the OWD measure, we develop a group decision making approach, and illustrate it with a numerical example.

  14. Arguments from Developmental Order.

    Science.gov (United States)

    Stöckle-Schobel, Richard

    2016-01-01

    In this article, I investigate a special type of argument regarding the role of development in theorizing about psychological processes and cognitive capacities. Among the issues that developmental psychologists study, discovering the ontogenetic trajectory of mechanisms or capacities underpinning our cognitive functions ranks highly. The order in which functions are developed or capacities are acquired is a matter of debate between competing psychological theories, and also philosophical conceptions of the mind - getting the role and the significance of the different steps in this order right could be seen as an important virtue of such theories. Thus, a special kind of strategy in arguments between competing philosophical or psychological theories is using developmental order in arguing for or against a given psychological claim. In this article, I will introduce an analysis of arguments from developmental order, which come in two general types: arguments emphasizing the importance of the early cognitive processes and arguments emphasizing the late cognitive processes. I will discuss their role in one of the central tools for evaluating scientific theories, namely in making inferences to the best explanation. I will argue that appeal to developmental order is, by itself, an insufficient criterion for theory choice and has to be part of an argument based on other core explanatory or empirical virtues. I will end by proposing a more concerted study of philosophical issues concerning (cognitive) development, and I will present some topics that also pertain to a full-fledged 'philosophy of development.'

  15. Birth order and psychopathology.

    Science.gov (United States)

    Risal, Ajay; Tharoor, Hema

    2012-07-01

    Ordinal position the child holds within the sibling ranking of a family is related to intellectual functioning, personality, behavior, and development of psychopathology. To study the association between birth order and development of psychopathology in patients attending psychiatry services in a teaching hospital. Hospital-based cross-sectional study. Retrospective file review of three groups of patients was carried out. Patient-related variables like age of onset, birth order, family type, and family history of mental illness were compared with psychiatry diagnosis (ICD-10) generated. SPSS 13; descriptive statistics and one-way analysis of variance (ANOVA) were used. Mean age of onset of mental illness among the adult general psychiatry patients (group I, n = 527) was found to be 33.01 ± 15.073, while it was 11.68 ± 4.764 among the child cases (group II, n = 47) and 26.74 ± 7.529 among substance abuse cases (group III, n = 110). Among group I patients, commonest diagnosis was depression followed by anxiety and somatoform disorders irrespective of birth order. Dissociative disorders were most prevalent in the first born child (36.7%) among group II patients. Among group III patients, alcohol dependence was maximum diagnosis in all birth orders. Depression and alcohol dependence was the commonest diagnosis in adult group irrespective of birth order.

  16. Birth Order and Psychopathology

    Directory of Open Access Journals (Sweden)

    Ajay Risal

    2012-01-01

    Full Text Available Context: Ordinal position the child holds within the sibling ranking of a family is related to intellectual functioning, personality, behavior, and development of psychopathology. Aim: To study the association between birth order and development of psychopathology in patients attending psychiatry services in a teaching hospital. Settings and Design: Hospital-based cross-sectional study. Materials and Methods: Retrospective file review of three groups of patients was carried out. Patient-related variables like age of onset, birth order, family type, and family history of mental illness were compared with psychiatry diagnosis (ICD-10 generated. Statistical Analysis: SPSS 13; descriptive statistics and one-way analysis of variance (ANOVA were used. Results: Mean age of onset of mental illness among the adult general psychiatry patients (group I, n = 527 was found to be 33.01 ± 15.073, while it was 11.68 ± 4.764 among the child cases (group II, n = 47 and 26.74 ± 7.529 among substance abuse cases (group III, n = 110. Among group I patients, commonest diagnosis was depression followed by anxiety and somatoform disorders irrespective of birth order. Dissociative disorders were most prevalent in the first born child (36.7% among group II patients. Among group III patients, alcohol dependence was maximum diagnosis in all birth orders. Conclusions: Depression and alcohol dependence was the commonest diagnosis in adult group irrespective of birth order.

  17. The birth order puzzle.

    Science.gov (United States)

    Zajonc, R B; Markus, H; Markus, G B

    1979-08-01

    Studies relating intellectual performance to birth order report conflicting results, some finding intellectual scores to increase, others to decrease with birth order. In contrast, the relationship between intellectual performance and family size is stable and consistently replicable. Why do these two highly related variables generate such divergent results? This birth order puzzle is resolved by means of the confluence model that quantifies the influences upon intellectual growth arising within the family context. At the time of a new birth, two opposing influences act upon intellectual growth of the elder sibling: (a) his or her intellectual environment is "diluted" and (b) he or she loses the "last-born's handicap" and begins serving as an intellectual resource to the younger sibling. Since these opposite effects are not equal in magnitude, the differences in intellectual performance among birth ranks are shown to be age dependent. While elder children may surpass their younger siblings in intellectual performance at some ages, they may be overtaken by them at others. Thus when age is taken into consideration, the birth order literature loses its chaotic character and an orderly pattern of results emerges.

  18. Arguments from Developmental Order

    Directory of Open Access Journals (Sweden)

    Richard eStöckle-Schobel

    2016-05-01

    Full Text Available In this article, I investigate a special type of argument regarding the role of development in theorising about psychological processes and cognitive capacities. Among the issues that developmental psychologists study, discovering the ontogenetic trajectory of mechanisms or capacities underpinning our cognitive functions ranks highly. The order in which functions are developed or capacities are acquired is a matter of debate between competing psychological theories, and also philosophical conceptions of the mind – getting the role and the significance of the different steps in this order right could be seen as an important virtue of such theories.Thus, a special kind of strategy in arguments between competing philosophical or psychological theories is using developmental order in arguing for or against a given psychological claim. In this article, I will introduce an analysis of arguments from developmental order, which come in two general types: arguments emphasising the importance of the early cognitive processes and arguments emphasising the late cognitive processes. I will discuss their role in one of the central tools for evaluating scientific theories, namely in making inferences to the best explanation. I will argue that appeal to developmental order is, by itself, an insufficient criterion for theory choice and has to be part of an argument based on other core explanatory or empirical virtues. I will end by proposing a more concerted study of philosophical issues concerning (cognitive development, and I will present some topics that also pertain to a full-fledged ‘philosophy of development’.

  19. Birth order and Risk of Childhood Cancer: A Pooled Analysis from Five U.S. States

    Science.gov (United States)

    Von Behren, Julie; Spector, Logan G.; Mueller, Beth A.; Carozza, Susan E.; Chow, Eric J.; Fox, Erin E.; Horel, Scott; Johnson, Kimberly J.; McLaughlin, Colleen; Puumala, Susan E.; Ross, Julie A.; Reynolds, Peggy

    2010-01-01

    The causes of childhood cancers are largely unknown. Birth order has been used as a proxy for prenatal and postnatal exposures, such as frequency of infections and in utero hormone exposures. We investigated the association between birth order and childhood cancers in a pooled case-control dataset. The subjects were drawn from population-based registries of cancers and births in California, Minnesota, New York, Texas, and Washington. We included 17,672 cases less than 15 years of age who were diagnosed from1980-2004 and 57,966 randomly selected controls born 1970-2004, excluding children with Down syndrome. We calculated odds ratios and 95% confidence intervals using logistic regression, adjusted for sex, birth year, maternal race, maternal age, multiple birth, gestational age, and birth weight. Overall, we found an inverse relationship between childhood cancer risk and birth order. For children in the fourth or higher birth order category compared to first-born children, the adjusted OR was 0.87 (95% CI: 0.81, 0.93) for all cancers combined. When we examined risks by cancer type, a decreasing risk with increasing birth order was seen in the central nervous system (CNS) tumors, neuroblastoma, bilateral retinoblastoma, Wilms tumor, and rhabdomyosarcoma. We observed increased risks with increasing birth order for acute myeloid leukemia but a slight decrease in risk for acute lymphoid leukemia. These risk estimates were based on a very large sample size which allowed us to examine rare cancer types with greater statistical power than in most previous studies, however the biologic mechanisms remain to be elucidated. PMID:20715170

  20. On stochastic differential equations with random delay

    International Nuclear Information System (INIS)

    Krapivsky, P L; Luck, J M; Mallick, K

    2011-01-01

    We consider stochastic dynamical systems defined by differential equations with a uniform random time delay. The latter equations are shown to be equivalent to deterministic higher-order differential equations: for an nth-order equation with random delay, the corresponding deterministic equation has order n + 1. We analyze various examples of dynamical systems of this kind, and find a number of unusual behaviors. For instance, for the harmonic oscillator with random delay, the energy grows as exp((3/2) t 2/3 ) in reduced units. We then investigate the effect of introducing a discrete time step ε. At variance with the continuous situation, the discrete random recursion relations thus obtained have intrinsic fluctuations. The crossover between the fluctuating discrete problem and the deterministic continuous one as ε goes to zero is studied in detail on the example of a first-order linear differential equation

  1. Occupational sun exposure and mycosis fungoides

    DEFF Research Database (Denmark)

    Morales-Suárez-Varela, Maria M.; Olsen, Jorn; Johansen, Preben

    2006-01-01

    OBJECTIVE: We sought to study the association between occupational sun exposure and mycosis fungoides (MF), a peripheral T-cell lymphoma. SUBJECTS and METHODS: A European multicenter case-control study including seven rare cases (one being MF) was conducted between 1995 and 1997. From the 118...... accepted cases, 104 were interviewed, of which 76 were definite cases. Population controls were selected randomly from the regions of case ascertainment. Information based on occupational experiences was coded according to industry types. A job exposure matrix was created according to the expected exposure...

  2. Nuclear order in copper

    DEFF Research Database (Denmark)

    Annila, A.J.; Clausen, K.N.; Lindgård, P-A.

    1990-01-01

    A new ordering vector k=(2π/a)(0, 2/3, 2/3) for fcc antiferromagnets has been found by neutron-diffraction experiments at nanokelvin temperatures in the nuclear-spin system of a 65Cu single crystal. The corresponding reflection together with the previously observed (100) Bragg peak show the prese......A new ordering vector k=(2π/a)(0, 2/3, 2/3) for fcc antiferromagnets has been found by neutron-diffraction experiments at nanokelvin temperatures in the nuclear-spin system of a 65Cu single crystal. The corresponding reflection together with the previously observed (100) Bragg peak show...

  3. 'Good Order and Police'

    DEFF Research Database (Denmark)

    Mührmann-Lund, Jørgen

    2016-01-01

    The emergence of police ordinances and police authorities in the early modern period has traditionally been seen as a way to discipline society in order to increase the power of the absolutist state. However, recent investigations of early modern policing in German and French regions show...... focused on local needs even after the creation of a royal police office in 1682. Policing mainly concerned the welfare and privileges of burghers in market towns until the introduction of a country police in 1791, when agrarian reforms began to erode the patriarchal order in the countryside. As a new way...

  4. Pervasive randomness in physics: an introduction to its modelling and spectral characterisation

    Science.gov (United States)

    Howard, Roy

    2017-10-01

    An introduction to the modelling and spectral characterisation of random phenomena is detailed at a level consistent with a first exposure to the subject at an undergraduate level. A signal framework for defining a random process is provided and this underpins an introduction to common random processes including the Poisson point process, the random walk, the random telegraph signal, shot noise, information signalling random processes, jittered pulse trains, birth-death random processes and Markov chains. An introduction to the spectral characterisation of signals and random processes, via either an energy spectral density or a power spectral density, is detailed. The important case of defining a white noise random process concludes the paper.

  5. Infinitely robust order and local order-parameter tulips in Apollonian networks with quenched disorder

    Science.gov (United States)

    Kaplan, C. Nadir; Hinczewski, Michael; Berker, A. Nihat

    2009-06-01

    For a variety of quenched random spin systems on an Apollonian network, including ferromagnetic and antiferromagnetic bond percolation and the Ising spin glass, we find the persistence of ordered phases up to infinite temperature over the entire range of disorder. We develop a renormalization-group technique that yields highly detailed information, including the exact distributions of local magnetizations and local spin-glass order parameters, which turn out to exhibit, as function of temperature, complex and distinctive tulip patterns.

  6. Higher-Order Hierarchies

    DEFF Research Database (Denmark)

    Ernst, Erik

    2003-01-01

    This paper introduces the notion of higher-order inheritance hierarchies. They are useful because they provide well-known benefits of object-orientation at the level of entire hierarchies-benefits which are not available with current approaches. Three facets must be adressed: First, it must be po...

  7. The Ordered Apology

    NARCIS (Netherlands)

    van Dijck, Gijs

    2017-01-01

    Psychological research has demonstrated that an apology can contribute to the well-being of the receiver of the apology. However, the legal community has only cautiously embraced the idea of claiming and ordering apologies in a legal procedure. The conventional wisdom is that apologies that are

  8. Even order snake resonances

    International Nuclear Information System (INIS)

    Lee, S.Y.

    1993-01-01

    We found that the perturbed spin tune due to the imperfection resonance plays an important role in beam depolarization at snake resonances. We also found that even order snake resonances exist in the overlapping intrinsic and imperfection resonances. Due to the perturbed spin tune shift of imperfection resonances, each snake resonance splits into two

  9. On Todorcevic orderings

    Czech Academy of Sciences Publication Activity Database

    Balcar, Bohuslav; Pazák, Tomáš; Thümmel, E.

    2015-01-01

    Roč. 228, č. 2 (2015), s. 173-192 ISSN 0016-2736 Institutional support: RVO:67985840 ; RVO:67985556 Keywords : partial ordering * countable chain condition * forcing Subject RIV: BA - General Mathematics Impact factor: 0.553, year: 2015 http://library.utia.cas.cz/separaty/2015/SI/pazak-0437623.pdf

  10. Birth Order Debate Resolved?

    Science.gov (United States)

    Zajonc, R. B.

    2001-01-01

    Critiques Rodgers et al.'s June 2000 research on the relation between birth order and intelligence, which suggests that it is a methodological illusion. Explains how the intellectual environment and the teaching function (whereby older children tutor younger ones) contribute to the growth of intellectual maturity, the first negatively and the…

  11. Order Division Automated System.

    Science.gov (United States)

    Kniemeyer, Justin M.; And Others

    This publication was prepared by the Order Division Automation Project staff to fulfill the Library of Congress' requirement to document all automation efforts. The report was originally intended for internal use only and not for distribution outside the Library. It is now felt that the library community at-large may have an interest in the…

  12. The Birth Order Puzzle.

    Science.gov (United States)

    Zajonc, R. B.; And Others

    1979-01-01

    Discusses the controversy of the relationship between birth order and intellectual performance through a detailed evaluation of the confluence model which assumes that the rate of intellectual growth is a function of the intellectual environment within the family and associated with the special circumstances of last children. (CM)

  13. The 'final order' problem

    NARCIS (Netherlands)

    Teunter, RH; Haneveld, WKK

    1998-01-01

    When the service department of a company selling machines stops producing and supplying spare parts for certain machines, customers are offered an opportunity to place a so-called final order for these spare parts. We focus on one customer with one machine. The customer plans to use this machine up

  14. Indoor exposure to natural radiation in Denmark

    International Nuclear Information System (INIS)

    Ulbak, K.; Stenum, B.; Soerensen, A.; Majborn, B.; Boetter-Jensen, L.; Nielsen, S.P.

    1988-01-01

    Assessment of the exposures to the Danish population from different natural radiation sources including building materials, drinking water, fly ash etc. has been performed from 1975 and up till now. In 1987 a comprehensive nationwide investigation of the gamma exposures and radon levels in 500 randomly selected Danish dwellings will be concluded by the National Institute of Radiation Hygiene. At the same time the Danish authorities will publish a control strategy for limiting the exposure of the Danish population from natural sources, especially from radon daughter exposure in dwellings. The presentation will outline the main results of the nationwide survey in Danish dwellings together with the main principles behind and the consequences of the initiated control strategy for limiting the exposures from natural radioactive sources

  15. An introduction to random interlacements

    CERN Document Server

    Drewitz, Alexander; Sapozhnikov, Artëm

    2014-01-01

    This book gives a self-contained introduction to the theory of random interlacements. The intended reader of the book is a graduate student with a background in probability theory who wants to learn about the fundamental results and methods of this rapidly emerging field of research. The model was introduced by Sznitman in 2007 in order to describe the local picture left by the trace of a random walk on a large discrete torus when it runs up to times proportional to the volume of the torus. Random interlacements is a new percolation model on the d-dimensional lattice. The main results covered by the book include the full proof of the local convergence of random walk trace on the torus to random interlacements and the full proof of the percolation phase transition of the vacant set of random interlacements in all dimensions. The reader will become familiar with the techniques relevant to working with the underlying Poisson Process and the method of multi-scale renormalization, which helps in overcoming the ch...

  16. Radiation exposure in homes through radon and thoron daughter products

    International Nuclear Information System (INIS)

    Schmier, H.

    1984-01-01

    In a random selection of about 6000 homes in the Federal Republic of Germany, the radon concentration in room air has been measured using a simple dosemeter developed by Karlsruhe Nuclear Research Centre. The mean radon concentration has been determined to be approximately 40-50 Bqu/m 3 . If this experiment is taken as a representative survey for the FRG, the mean dose contributed by the natural radiation exposure through radon and its short-lived decay products to the effective annual dose to the lungs can be computed to be about 1 mSv (100 mrem), using the internationally accepted conversion factors. Apart from this survey, special radon measuring programmes have been carried out, including simultaneous recording of meteorological data, in order to obtain information on the parameters to be taken into account when describing the daily variations of radon concentrations. (orig./DG) [de

  17. Medical exposure and the effects of radiation

    International Nuclear Information System (INIS)

    Okuyama, Chio

    2011-01-01

    Radiation gives cracks to genes. The influence is divided into deterministic effect with a threshold value, and the stochastic effect (tumor and genetic effect) which increases according to the exposure amount. Although we are put to various non-artificial radiations, which we cannot be avoided, on the earth, the contamination by artificial radiation can be defended. Artificial radioactive exposure includes medical exposure and non-medical exposure for example by nuclear power plant. As to medical examinations using radiation, the inquiry about the radiation exposure is increasing after the occurrence of the first nuclear power plant disaster of Fukushima. While concern about non-medical radioactive exposure increases, the uneasiness to medical irradiation is also increasing. The dose limit by artificial radioactive exposure other than medical exposure is set up in order to prevent the influence on the health. While the dose limit of the public exposure is set to the lower value than the total dose of non-artificial exposure concerning of a safety margin for all people, the dose limit of medical exposure is not defined, since it is thought that medical irradiation has a benefit for those who receive irradiation. Making an effort to decrease the radiation dose in performing the best medical treatment is the responsibility with which we are burdened. (author)

  18. Magnetic Excitations and Magnetic Ordering in Praseodymium

    DEFF Research Database (Denmark)

    Houmann, Jens Christian Gylden; Chapellier, M.; Mackintosh, A. R.

    1975-01-01

    The dispersion relations for magnetic excitons propagating on the hexagonal sites of double-hcp Pr provide clear evidence for a pronounced anisotropy in the exchange. The energy of the excitations decreases rapidly as the temperature is lowered, but becomes almost constant below about 7 K......, in agreement with a random-phase-approximation calculation. No evidence of magnetic ordering has been observed above 0.4 K, although the exchange is close to the critical value necessary for an antiferromagnetic state....

  19. Robert's rules of order

    CERN Document Server

    Robert, Henry M; Balch, Thomas J; Seabold, Daniel E; Gerber, Shmuel

    2011-01-01

    The only authorized edition of the classic work on parliamentary procedure, with new and enhanced features, including how to conduct electronic meetings. Robert's Rules of Order is the book on parliamentary procedure for parliamentarians and anyone involved in an organization, association, club, or group and the authoritative guide to smooth, orderly, and fairly conducted meetings and assemblies. This newly revised edition is the only book on parliamentary procedure to have been updated since 1876 under the continuing program of review established by General Henry M. Robert himself, in cooperation with the official publisher of Robert's Rules. The eleventh edition has been thoroughly revised to address common inquiries and incorporate new rules, interpretations, and procedures made necessary by the evolution of parliamentary procedure, including new material relating to electronic communication and "electronic meetings."

  20. Fragile Thermodynamic Order

    International Nuclear Information System (INIS)

    Bernhoeft, N.; Lander, G.H.; Colineau, E.

    2003-01-01

    An asymmetric shift in the position of the magnetic Bragg peak with respect to the fiducial lattice has been observed by resonant X-ray scattering in a diverse series of antiferromagnetic compounds. This apparent violation of Bragg's law is interpreted in terms of a dynamically phased order parameter. We demonstrate the use of this effect as a novel probe of fragile or dynamic thermodynamic order in strongly correlated electronic systems. In particular, fresh light is shed on the paradoxical situation encountered in URu 2 Si 2 where the measured entropy gain on passing through T Neel is incompatible with the ground state moment estimated by neutron diffraction. The intrinsic space-time averaging of the probe used to characterise the thermodynamic macroscopic state may play a crucial and previously neglected role. In turn, this suggests the further use of resonant X-ray scattering in investigations of systems dominated by quantum fluctuations. (author)

  1. Transnational Normative Orders

    DEFF Research Database (Denmark)

    Kjaer, Poul F.

    2013-01-01

    No weakening, but rather an expansion, of statehood can be observed in the contemporary world. This does not, on the other hand, imply that extensive forms of constitutional ordering do not exist outside the realm of states. Instead, the evolution of world society has been characterized by a prot......No weakening, but rather an expansion, of statehood can be observed in the contemporary world. This does not, on the other hand, imply that extensive forms of constitutional ordering do not exist outside the realm of states. Instead, the evolution of world society has been characterized...... as represented by the constitutional subject. Third, constitutionalism denotes the institutionalization of a double function, in the form of a principle-based and legally fortified striving toward universal inclusion, providing a sense of direction in time through an articulated form of constitutional...

  2. Transnational Normative Orders

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2017-01-01

    No weakening, but rather an expansion, of statehood can be observed in the contemporary world. This does not, on the other hand, imply that extensive forms of constitutional ordering do not exist outside the realm of states. Instead, the evolution of world society has been characterized by a prot......No weakening, but rather an expansion, of statehood can be observed in the contemporary world. This does not, on the other hand, imply that extensive forms of constitutional ordering do not exist outside the realm of states. Instead, the evolution of world society has been characterized...... as represented by the constitutional subject. Third, constitutionalism denotes the institutionalization of a double function, in the form of a principle-based and legally fortified striving toward universal inclusion, providing a sense of direction in time through an articulated form of constitutional...

  3. Ordered cones and approximation

    CERN Document Server

    Keimel, Klaus

    1992-01-01

    This book presents a unified approach to Korovkin-type approximation theorems. It includes classical material on the approximation of real-valuedfunctions as well as recent and new results on set-valued functions and stochastic processes, and on weighted approximation. The results are notonly of qualitative nature, but include quantitative bounds on the order of approximation. The book is addressed to researchers in functional analysis and approximation theory as well as to those that want to applythese methods in other fields. It is largely self- contained, but the readershould have a solid background in abstract functional analysis. The unified approach is based on a new notion of locally convex ordered cones that are not embeddable in vector spaces but allow Hahn-Banach type separation and extension theorems. This concept seems to be of independent interest.

  4. Are Limit Orders Rational?

    Czech Academy of Sciences Publication Activity Database

    Šmíd, Martin

    2007-01-01

    Roč. 14, č. 4 (2007), s. 32-38 ISSN 0572-3043 R&D Projects: GA ČR(CZ) GA402/06/1417; GA ČR GA402/04/1294; GA ČR GD402/03/H057 Institutional research plan: CEZ:AV0Z10750506 Keywords : market microstructure * limit order market * portfolio selection Subject RIV: AH - Economics

  5. Birth Order and Psychopathology

    OpenAIRE

    Risal, Ajay; Tharoor, Hema

    2012-01-01

    Context: Ordinal position the child holds within the sibling ranking of a family is related to intellectual functioning, personality, behavior, and development of psychopathology. Aim: To study the association between birth order and development of psychopathology in patients attending psychiatry services in a teaching hospital. Settings and Design: Hospital-based cross-sectional study. Materials and Methods: Retrospective file review of three groups of patients was carried out. Patient-relat...

  6. Testing hypotheses in order

    OpenAIRE

    Paul R. Rosenbaum

    2008-01-01

    In certain circumstances, one wishes to test one hypothesis only if certain other hypotheses have been rejected. This ordering of hypotheses simplifies the task of controlling the probability of rejecting any true hypothesis. In an example from an observational study, a treated group is shown to be further from both of two control groups than the two control groups are from each other. Copyright 2008, Oxford University Press.

  7. Increased body satisfaction after exposure to thin ideal children's television in young girls showing thin ideal internalisation.

    Science.gov (United States)

    Anschutz, Doeschka J; Engels, Rutger C M E; Van Strien, Tatjana

    2012-01-01

    This study tested the direct effect of watching thin ideal children's television on body satisfaction in preadolescent girls (6-8 years old). A within-subject design was used in which girls (N = 51) were tested three times. They watched television clips in random order containing either (1) thin ideal animated characters or (2) animated characters with no thin ideal features or (3) 'real' human actors with no thin ideal features. After watching, their state body satisfaction was measured. Girls with higher levels of thin ideal internalisation showed higher body satisfaction after exposure to the thin ideal characters than after exposure to animated or real characters featuring no thin ideal features. No differences on body satisfaction between the exposure conditions were found in girls with lower levels of thin ideal internalisation. The results might suggest that young girls who internalised the thin ideal are inspired by thin ideal characters in children's media.

  8. Hierarchical partial order ranking

    International Nuclear Information System (INIS)

    Carlsen, Lars

    2008-01-01

    Assessing the potential impact on environmental and human health from the production and use of chemicals or from polluted sites involves a multi-criteria evaluation scheme. A priori several parameters are to address, e.g., production tonnage, specific release scenarios, geographical and site-specific factors in addition to various substance dependent parameters. Further socio-economic factors may be taken into consideration. The number of parameters to be included may well appear to be prohibitive for developing a sensible model. The study introduces hierarchical partial order ranking (HPOR) that remedies this problem. By HPOR the original parameters are initially grouped based on their mutual connection and a set of meta-descriptors is derived representing the ranking corresponding to the single groups of descriptors, respectively. A second partial order ranking is carried out based on the meta-descriptors, the final ranking being disclosed though average ranks. An illustrative example on the prioritisation of polluted sites is given. - Hierarchical partial order ranking of polluted sites has been developed for prioritization based on a large number of parameters

  9. Factors affecting medication-order processing time.

    Science.gov (United States)

    Beaman, M A; Kotzan, J A

    1982-11-01

    The factors affecting medication-order processing time at one hospital were studied. The order processing time was determined by directly observing the time to process randomly selected new drug orders on all three work shifts during two one-week periods. An order could list more than one drug for an individual patient. The observer recorded the nature, location, and cost of the drugs ordered, as well as the time to process the order. The time and type of interruptions also were noted. The time to process a drug order was classified as six dependent variables: (1) total time, (2) work time, (3) check time, (4) waiting time I--time from arrival on the dumbwaiter until work was initiated, (5) waiting time II--time between completion of the work and initiation of checking, and (6) waiting time III--time after the check was completed until the order left on the dumbwaiter. The significant predictors of each of the six dependent variables were determined using stepwise multiple regression. The total time to process a prescription order was 58.33 +/- 48.72 minutes; the urgency status of the order was the only significant determinant of total time. Urgency status also significantly predicted the three waiting-time variables. Interruptions and the number of drugs on the order were significant determinants of work time and check time. Each telephone interruption increased the work time by 1.72 minutes. While the results of this study cannot be generalized to other institutions, pharmacy managers can use the method of determining factors that affect medication-order processing time to identify problem areas in their institutions.

  10. Exposure to Poverty and Productivity.

    Directory of Open Access Journals (Sweden)

    Patricio S Dalton

    Full Text Available We study whether exposure to poverty can induce affective states that decrease productivity. In a controlled laboratory setting, we find that subjects randomly assigned to a treatment, in which they view a video featuring individuals that live in extreme poverty, exhibit lower subsequent productivity compared to subjects assigned to a control treatment. Questionnaire responses, as well as facial recognition software, provide quantitative measures of the affective state evoked by the two treatments. Subjects exposed to images of poverty experience a more negative affective state than those in the control treatment. Further analysis shows that individuals in a more positive emotional state exhibit less of a treatment effect. Also, those who exhibit greater attentiveness upon viewing the poverty video are less productive. The results are consistent with the notion that exposure to poverty can induce a psychological state in individuals that adversely affects productivity.

  11. Exposure to Poverty and Productivity

    Science.gov (United States)

    2017-01-01

    We study whether exposure to poverty can induce affective states that decrease productivity. In a controlled laboratory setting, we find that subjects randomly assigned to a treatment, in which they view a video featuring individuals that live in extreme poverty, exhibit lower subsequent productivity compared to subjects assigned to a control treatment. Questionnaire responses, as well as facial recognition software, provide quantitative measures of the affective state evoked by the two treatments. Subjects exposed to images of poverty experience a more negative affective state than those in the control treatment. Further analysis shows that individuals in a more positive emotional state exhibit less of a treatment effect. Also, those who exhibit greater attentiveness upon viewing the poverty video are less productive. The results are consistent with the notion that exposure to poverty can induce a psychological state in individuals that adversely affects productivity. PMID:28125621

  12. Noise exposure in marching bands

    Science.gov (United States)

    Keefe, Joseph

    2005-09-01

    Previous studies involving orchestras have shown that music ensembles can produce hazardous noise levels. There are no similar data for marching bands and pep bands. In order to evaluate the noise levels produced by marching and pep bands, 1/3-octave-band sound-pressure levels were measured while these groups rehearsed and performed. Data were collected while marching with the bands to ensure a realistic environment. Comparing these data to OSHA and NIOSH criteria, marching and pep band exposures often exceed safe values. For typical exposures, OSHA doses range from 11% to 295%, while NIOSH doses range from 35% to 3055%. Exposures that would be considered hazardous in the workplace are common in marching and pep bands; students and band directors should take steps to recognize the risk posed by various instruments and various locations, and should implement hearing conservation efforts.

  13. Random broadcast on random geometric graphs

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Elsasser, Robert [UNIV OF PADERBORN; Friedrich, Tobias [ICSI/BERKELEY; Sauerwald, Tomas [ICSI/BERKELEY

    2009-01-01

    In this work, we consider the random broadcast time on random geometric graphs (RGGs). The classic random broadcast model, also known as push algorithm, is defined as: starting with one informed node, in each succeeding round every informed node chooses one of its neighbors uniformly at random and informs it. We consider the random broadcast time on RGGs, when with high probability: (i) RGG is connected, (ii) when there exists the giant component in RGG. We show that the random broadcast time is bounded by {Omicron}({radical} n + diam(component)), where diam(component) is a diameter of the entire graph, or the giant component, for the regimes (i), or (ii), respectively. In other words, for both regimes, we derive the broadcast time to be {Theta}(diam(G)), which is asymptotically optimal.

  14. Quantumness, Randomness and Computability

    International Nuclear Information System (INIS)

    Solis, Aldo; Hirsch, Jorge G

    2015-01-01

    Randomness plays a central role in the quantum mechanical description of our interactions. We review the relationship between the violation of Bell inequalities, non signaling and randomness. We discuss the challenge in defining a random string, and show that algorithmic information theory provides a necessary condition for randomness using Borel normality. We close with a view on incomputablity and its implications in physics. (paper)

  15. Fractional Order Generalized Information

    Directory of Open Access Journals (Sweden)

    José Tenreiro Machado

    2014-04-01

    Full Text Available This paper formulates a novel expression for entropy inspired in the properties of Fractional Calculus. The characteristics of the generalized fractional entropy are tested both in standard probability distributions and real world data series. The results reveal that tuning the fractional order allow an high sensitivity to the signal evolution, which is useful in describing the dynamics of complex systems. The concepts are also extended to relative distances and tested with several sets of data, confirming the goodness of the generalization.

  16. Partially ordered algebraic systems

    CERN Document Server

    Fuchs, Laszlo

    2011-01-01

    Originally published in an important series of books on pure and applied mathematics, this monograph by a distinguished mathematician explores a high-level area in algebra. It constitutes the first systematic summary of research concerning partially ordered groups, semigroups, rings, and fields. The self-contained treatment features numerous problems, complete proofs, a detailed bibliography, and indexes. It presumes some knowledge of abstract algebra, providing necessary background and references where appropriate. This inexpensive edition of a hard-to-find systematic survey will fill a gap i

  17. Ordering, materiality and multiplicity

    DEFF Research Database (Denmark)

    van der Duim, René; Ren, Carina Bregnholm; Jóhannesson, Gunnar Thór

    2013-01-01

    In this article we discuss how ANT has been translated into tourism research and show how it has impacted the field by presenting three concepts integral to the ANT approach: ordering, materiality and multiplicity. We first introduce ANT and draw attention to current ANT studies in tourism......, followed by a discussion of how newer approaches within post-ANT urge us to face the ontological politics, which we engage in when performing tourism research. In conclusion we argue that ANT enables a radical new way at looking at tourism, tourism destinations and objects and investigations...... into the ontological condition of tourism....

  18. Gender Orders Unbound?

    DEFF Research Database (Denmark)

    During the last thirty years, the modernisation of gender relations has been dynamic and comprehensive, shaped by the conflicting forces of globalisation as well as women's movements around the world. As the patterns of segregation and discrimination of the classical industrial gender order erode......, new complexities and contentions in gender relations emerge at various sites such as politics, work and families. The main aim of the book is to trace formal as well as informal gender contracts as they emerge in everyday life and also in new norms and regulations set by state and enterprises. Core...... issues are the chances and the barriers for equality and new forms of gender reciprocity and solidarity....

  19. How random is a random vector?

    Science.gov (United States)

    Eliazar, Iddo

    2015-12-01

    Over 80 years ago Samuel Wilks proposed that the "generalized variance" of a random vector is the determinant of its covariance matrix. To date, the notion and use of the generalized variance is confined only to very specific niches in statistics. In this paper we establish that the "Wilks standard deviation" -the square root of the generalized variance-is indeed the standard deviation of a random vector. We further establish that the "uncorrelation index" -a derivative of the Wilks standard deviation-is a measure of the overall correlation between the components of a random vector. Both the Wilks standard deviation and the uncorrelation index are, respectively, special cases of two general notions that we introduce: "randomness measures" and "independence indices" of random vectors. In turn, these general notions give rise to "randomness diagrams"-tangible planar visualizations that answer the question: How random is a random vector? The notion of "independence indices" yields a novel measure of correlation for Lévy laws. In general, the concepts and results presented in this paper are applicable to any field of science and engineering with random-vectors empirical data.

  20. How random is a random vector?

    International Nuclear Information System (INIS)

    Eliazar, Iddo

    2015-01-01

    Over 80 years ago Samuel Wilks proposed that the “generalized variance” of a random vector is the determinant of its covariance matrix. To date, the notion and use of the generalized variance is confined only to very specific niches in statistics. In this paper we establish that the “Wilks standard deviation” –the square root of the generalized variance–is indeed the standard deviation of a random vector. We further establish that the “uncorrelation index” –a derivative of the Wilks standard deviation–is a measure of the overall correlation between the components of a random vector. Both the Wilks standard deviation and the uncorrelation index are, respectively, special cases of two general notions that we introduce: “randomness measures” and “independence indices” of random vectors. In turn, these general notions give rise to “randomness diagrams”—tangible planar visualizations that answer the question: How random is a random vector? The notion of “independence indices” yields a novel measure of correlation for Lévy laws. In general, the concepts and results presented in this paper are applicable to any field of science and engineering with random-vectors empirical data.

  1. Medium wave exposure characterisation using exposure quotients.

    Science.gov (United States)

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Pinar, Iván

    2010-06-01

    One of the aspects considered in the International Commission on Non-Ionizing Radiation Protection guidelines is that, in situations of simultaneous exposure to fields of different frequencies, exposure quotients for thermal and electrical stimulation effects should be examined. The aim of the present work was to analyse the electromagnetic radiation levels and exposure quotients for exposure to multiple-frequency sources in the vicinity of medium wave radio broadcasting antennas. The measurements were made with a spectrum analyser and a monopole antenna. Kriging interpolation was used to prepare contour maps and to estimate the levels in the towns and villages of the zone. The results showed that the exposure quotient criterion based on electrical stimulation effects to be more stringent than those based on thermal effects or power density levels. Improvement of dosimetry evaluations requires the spectral components of the radiation to be quantified, followed by application of the criteria for exposure to multiple-frequency sources.

  2. Integration of Probabilistic Exposure Assessment and Probabilistic Hazard Characterization

    NARCIS (Netherlands)

    Voet, van der H.; Slob, W.

    2007-01-01

    A method is proposed for integrated probabilistic risk assessment where exposure assessment and hazard characterization are both included in a probabilistic way. The aim is to specify the probability that a random individual from a defined (sub)population will have an exposure high enough to cause a

  3. The students’ coordinating conjunction acquisition order

    Directory of Open Access Journals (Sweden)

    Deby Irawan

    2018-03-01

    Full Text Available This study is aimed at uncovering the students’ acquisition order of coordinating conjunction for then to seek the possible causes of such phenomenon. Quantitative approach with implicational scaling and qualitative approach with case study were employed with test, focused-group interview, and document analysis of some related textbooks as the instruments. A test consist of 70 questions about the usage of seven coordinating conjunctions in which each word is represented by 10 questions was given to the 13 students of eleventh grade of senior high school for the data collection related to the students’ acquisition order. The documents were then analyzed through several steps as suggested by the expert. The results show that the students acquire “and”, “so”, “for”, “but”, “or”, “yet”, and “nor” as in order. The external factors which influence the order are the formal complexity of each conjunction and the lack of exposure of coordinating conjunction both in the teaching activity and textbooks. Thus, teachers are suggested to provide more explicit teaching on coordinating conjunction and necessary knowledge about the usage of each word. Also, book writers should provide ample exposure to give students more knowledge about the usage of those conjunctions in a meaningful context.

  4. Ordered photonic microstructures

    Science.gov (United States)

    Chen, Kevin Ming

    2001-09-01

    This thesis examines novel photonic materials systems possessing order in the atomic, microscopic, and macroscopic dimensional regimes. In the atomic order regime, a structure-property investigation is done for Er2O3 in which the first report of room temperature photoluminescence (PL) is provided. Thin films of the rare earth oxide were deposited via reactive sputtering of Er metal in an Ar/O2 ambient, and subsequently annealed to promote grain growth. Heat treatment consisting of a 650°C followed by 1000°C anneal produces maximum crystallinity as measured by glancing angle x-ray diffraction. These films show characteristic PL at λ = 1.54 μm. In the microscopic order regime, omnidirectional reflectors and thin film microcavities are demonstrated using sol-gel and solid-state materials. A first demonstration of omnidirectional reflectivity in sol-gel structures was accomplished using a dielectric stack consisting of 12 spin-on SiO 2/TiO2 quarterwave sol-gel films. Similarly, solid-state dielectric stacks consisting of 6 Si/SiO2 sputtered films were used to demonstrate the same principle. Microcavities were formed using solgel structures, producing a low quality factor Q = 35 due to limitations in film thickness control and lossy interfaces from stress-induced cracks. The high index contrast Si/SiO2 microcavities enabled Q ~ 1000 using 17 total layers following hydrogenation of dangling bonds within the amorphous Si films. Combining fabrication processes for the solid-state microcavity and Er2O3 films, a device was fabricated to demonstrate photoluminescence enhancement of an Er2O3 film embedded in a microcavity. The structure consisted of 3-bilayer mirrors on either side of an SiO2/Er2O3/SiO2 cavity. The Q ~ 300 was near the theoretical value for such a structure. At room temperature, PL of Er2O3 was enhanced by a factor of 1000 in the microcavity compared to a single thin film. In the macroscopic order regime, self-assembly of micron- sized SiO 2 and

  5. Personal exposure control system

    International Nuclear Information System (INIS)

    Tanabe, Ken-ichi; Akashi, Michio

    1994-01-01

    Nuclear power stations are under strict radiation control. Exposure control for nuclear workers is the most important operation, and so carefully thought out measures are taken. This paper introduces Fuji Electric's personal exposure control system that meets strict exposure control and rationalizes control operations. The system has a merit that it can provide required information in an optimum form using the interconnection of a super minicomputer and exposure control facilities and realizes sophisticated exposure control operations. (author)

  6. Society's general exposure to risk

    International Nuclear Information System (INIS)

    Lidstone, R.F.

    1981-10-01

    Canadian and world experience with accidents and disease is reviewed in order to identify risk information that might extend the societal perspective on health risk beyond daily concerns. The level of exposure to catastrophic risks is compared to that associated with commonly experienced risks. An examination of current and historical levels of Canadian mortality risk is included. The association between mortality risk and Canadian industrial activity is also examined. Some prospects for utilizing these risk benchmarks are then discussed

  7. An unbiased estimator of the variance of simple random sampling using mixed random-systematic sampling

    OpenAIRE

    Padilla, Alberto

    2009-01-01

    Systematic sampling is a commonly used technique due to its simplicity and ease of implementation. The drawback of this simplicity is that it is not possible to estimate the design variance without bias. There are several ways to circumvent this problem. One method is to suppose that the variable of interest has a random order in the population, so the sample variance of simple random sampling without replacement is used. By means of a mixed random - systematic sample, an unbiased estimator o...

  8. The Emerging World Order

    Directory of Open Access Journals (Sweden)

    PETER COLLECOTT

    2014-05-01

    Full Text Available It is common ground amongst almost all commentators that the world has changed radically over the past 25 years – the 25 years since the fall of the Berlin Wall heralded the ending of the Cold War, the reunification of a tragically divided Europe, and the acceleration of the process of globalisation which has its only comparable period in the decades leading up to the First World War in 1914. When analyzing the Emerging World Order it is important to cover more than Brazil economy or any other individual BRICs or other Emerging Powers. Instead, our analysis will provide a global view about the economic and political global power structures which are evolving and forming before our eyes, and then to talk about the challenges these emerging realities pose for us in Europe, and in the West in general.

  9. The new Wuergassen order

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    In the contentious administrative matter concerning the contestation of several partial licenses for the Wuergassen nuclear power station, the Supreme Court of Administration for Nordrhein-Westfalen, has also dismissed the appeal of the plaintiff from the dismissal of the action delivered by the Minden administrative court. The order was passed on 20th February, 1975 - VII A 911/69 - and agrees with the dismissal by the Federal Administrative Court. The plaintiff was a private person. The defendants were the licensing authorities, the Minister for Economy, and the Minister fuer Wirtschaft, Mittelstand und Verkehr of Nordrhein-Westfalen. Also summoned was the Preussische Elektrizitaets-AG, Hannover, to whom the contested licenses had been issued. The value in litigation was fixed at DM 10,000. One half of the extra-judicial costs of the summoned was declared repayable. Some of the grounds upon which the judgment was based are presented in detail. (orig./AK) [de

  10. Higher Order Mode Fibers

    DEFF Research Database (Denmark)

    Israelsen, Stine Møller

    This PhD thesis considers higher order modes (HOMs) in optical fibers. That includes their excitation and characteristics. Within the last decades, HOMs have been applied both for space multiplexing in optical communications, group velocity dispersion management and sensing among others......-radial polarization as opposed to the linear polarization of the LP0X modes. The effect is investigated numerically in a double cladding fiber with an outer aircladding using a full vectorial modesolver. Experimentally, the bowtie modes are excited using a long period grating and their free space characteristics...... and polarization state are investigated. For this fiber, the onset of the bowtie effect is shown numerically to be LP011. The characteristics usually associated with Bessel-likes modes such as long diffraction free length and selfhealing are shown to be conserved despite the lack of azimuthal symmetry...

  11. Birth order and myopia.

    Science.gov (United States)

    Guggenheim, Jeremy A; McMahon, George; Northstone, Kate; Mandel, Yossi; Kaiserman, Igor; Stone, Richard A; Lin, Xiaoyu; Saw, Seang Mei; Forward, Hannah; Mackey, David A; Yazar, Seyhan; Young, Terri L; Williams, Cathy

    2013-12-01

    An association between birth order and reduced unaided vision (a surrogate for myopia) has been observed previously. We examined the association between birth order and myopia directly in four subject groups. Subject groups were participants in (1) the Avon Longitudinal Study of Parents and Children (ALSPAC; UK; age 15 years; N = 4401), (2) the Singapore Cohort Study of Risk Factors for Myopia (SCORM; Singapore; age 13 years; N = 1959), (3) the Raine Eye Health Study (REHS; Australia; age 20 years; N = 1344), and (4) Israeli Defense Force Pre-recruitment Candidates (IDFC; Israel; age 16-22 years; N = 888,277). The main outcome was odds ratios (OR) for myopia in first-born versus non-first-born individuals after adjusting for potential risk factors. The prevalence of myopia was numerically higher in first-born versus non-first-born individuals in all study groups, but the strength of evidence varied widely. Adjusted ORs (95% confidence intervals, CIs) were: ALSPAC, 1.31 (1.05-1.64); SCORM, 1.25 (0.89-1.77); REHS, 1.18 (0.90-1.55); and IDFC, 1.04 (1.03-1.06). In the large IDFC sample, the effect size was greater (a) for the first-born versus fourth- or higher-born comparison than for the first-born versus second/third-born comparison (p 4000 participants provided strong statistical support for the association. The available evidence suggested the relationship was independent of established risk factors such as time outdoors/reading, and thus may arise through a different causal mechanism.

  12. Sensitivity analysis of ranked data: from order statistics to quantiles

    NARCIS (Netherlands)

    Heidergott, B.F.; Volk-Makarewicz, W.

    2015-01-01

    In this paper we provide the mathematical theory for sensitivity analysis of order statistics of continuous random variables, where the sensitivity is with respect to a distributional parameter. Sensitivity analysis of order statistics over a finite number of observations is discussed before

  13. Everolimus with reduced calcineurin inhibitor in thoracic transplant recipients with renal dysfunction: a multicenter, randomized trial

    DEFF Research Database (Denmark)

    Gullestad, Lars; Iversen, Martin; Mortensen, Svend-Aage

    2010-01-01

    The proliferation signal inhibitor everolimus offers the potential to reduce calcineurin inhibitor (CNI) exposure and alleviate CNI-related nephrotoxicity. Randomized trials in maintenance thoracic transplant patients are lacking.......The proliferation signal inhibitor everolimus offers the potential to reduce calcineurin inhibitor (CNI) exposure and alleviate CNI-related nephrotoxicity. Randomized trials in maintenance thoracic transplant patients are lacking....

  14. Development of three-dimensional shoulder kinematic and electromyographic exposure variation analysis methodology in violin musicians.

    Science.gov (United States)

    Reynolds, Jonathan F; Leduc, Robert E; Kahnert, Emily K; Ludewig, Paula M

    2014-01-01

    A total of 11 male and 19 female violinists performed 30-second random-ordered slow and fast musical repertoire while right shoulder three-dimensional kinematic, and upper trapezius and serratus anterior surface electromyography (EMG) data were summarised using exposure variation analysis (EVA), a bivariate distribution of work time spent at categories of signal amplitude, and duration spent at a fixed category of amplitude. Sixty-two per cent of intraclass correlation coefficients [1,1] for all kinematic and EMG variables exceeded 0.75, and 40% of standard error of the measurement results were below 5%, confirming EVA reliability. When fast repertoire was played, increases in odds ratios in short duration cells were seen in 23 of 24 possible instances, and decreases in longer duration cells were seen in 17 instances in all EVA arrays using multinomial logistic regression with random effects, confirming a shift towards shorter duration. A reliable technique to assess right shoulder kinematic and EMG exposure in violinists was identified. A reliable method of measuring right shoulder motion and muscle activity exposure variation in violinists was developed which can be used to assess ergonomic risk in other occupations. Recently developed statistical methods enabled differentiation between fast and slow musical performance of standardised musical repertoire.

  15. Numerical study of microphase separation in gels and random media

    International Nuclear Information System (INIS)

    Uchida, Nariya

    2004-01-01

    Microphase separation in gels and random media is numerically studied using a Ginzburg-Landau model. A random field destroys long-range orientational (lamellar) order and gives rise to a disordered bicontinuous morphology. The dependence of the correlation length on the field strength is distinct from that of random-field magnets

  16. Average-case analysis of incremental topological ordering

    DEFF Research Database (Denmark)

    Ajwani, Deepak; Friedrich, Tobias

    2010-01-01

    Many applications like pointer analysis and incremental compilation require maintaining a topological ordering of the nodes of a directed acyclic graph (DAG) under dynamic updates. All known algorithms for this problem are either only analyzed for worst-case insertion sequences or only evaluated...... experimentally on random DAGs. We present the first average-case analysis of incremental topological ordering algorithms. We prove an expected runtime of under insertion of the edges of a complete DAG in a random order for the algorithms of Alpern et al. (1990) [4], Katriel and Bodlaender (2006) [18], and Pearce...

  17. Taste the feeling or feel the tasting: Tactile exposure to food texture promotes food acceptance.

    Science.gov (United States)

    Nederkoorn, Chantal; Theiβen, Julia; Tummers, Michelle; Roefs, Anne

    2018-01-01

    The texture of food can be a reason why children reject it: It matters if food is crispy, slimy, smooth or has pips and bits in it. In general, mere exposure is the best method to increase acceptance of food: becoming more familiar with a food by repeated exposure increases liking for it. However, exposure to texture can be difficult, as children can be reluctant to try tasting it. In the current study, it is tested if acceptance of a food with a specific texture is improved after exposure to the feel of it, with hands only. Sixty-six children (between 3 and 10 years old) were randomly assigned to either the exposure or control condition. In the exposure condition, children played with an colourless and odourless jelly with their hands and in the control group, children played a board game. Afterwards, children were asked to taste 3 desserts (in balanced order): smooth strawberry yoghurt, strawberry yoghurt with pieces and strawberry jelly. Results showed that the children in the exposure condition ate specifically more of the jelly dessert - the texture of which they had been pre-exposed to - compared to the children in control condition. No group differences were found for the other two desserts. The results imply that feeling the texture of a food with hands increases the acceptance of food with the same texture. Playing with food with hands seems therefore be a first step in getting familiar with food and might help to increase variety of food intake. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Tetrachloroethylene exposure and bladder cancer risk

    DEFF Research Database (Denmark)

    Vlaanderen, Jelle; Straif, Kurt; Ruder, Avima

    2014-01-01

    BACKGROUND: In 2012, the International Agency for Research on Cancer classified tetrachloroethylene, used in the production of chemicals and the primary solvent used in dry cleaning, as "probably carcinogenic to humans" based on limited evidence of an increased risk of bladder cancer in dry...... cleaners. OBJECTIVES: We assessed the epidemiological evidence for the association between tetrachloroethylene exposure and bladder cancer from published studies estimating occupational exposure to tetrachloroethylene or in workers in the dry-cleaning industry. METHODS: Random-effects meta-analyses were...... carried out separately for occupational exposure to tetrachloroethylene and employment as a dry cleaner. We qualitatively summarized exposure-response data because of the limited number of studies available. RESULTS: The meta-relative risk (mRR) among tetrachloroethylene-exposed workers was 1.08 (95% CI...

  19. Exposure of healthy subjects with emissions from a gas metal arc welding process: part 3--biological effect markers and lung function.

    Science.gov (United States)

    Brand, P; Bischof, K; Siry, L; Bertram, J; Schettgen, T; Reisgen, U; Kraus, T; Gube, M

    2013-01-01

    Metal active gas welding (MAG) is a widely-used welding technique resulting in high emissions of welding fume particles. This study investigated whether short-term exposure to these fume particles results in changes in lung function and early stages of inflammatory reactions. Twelve healthy, young male subjects were exposed to MAG fumes for 6 h with three different exposure concentrations in a three-fold cross-over study design. Exposure was performed in the "Aachen Workplace Simulation Laboratory" under controlled conditions with constant fume concentration. Fume concentrations were 0, 1, and 2.5 mg m(-3) in randomized order. Before and after each exposure, spirometry, and impulse oscillometry were performed and breath condensate samples were collected in order to quantify inflammatory markers like Nitrate, Nitrite, Nitrotyrosine, Hydroxyprolin and Malondialdehyde. A significant dependency on the exposure concentration could not be established for any of the endpoint parameters. In healthy, young subjects neither changes in spirometry nor changes in inflammatory markers measured in exhaled breath condensate could be detected after short-term exposure.

  20. A National Study on Nurses' Exposure to Occupational Violence in Lebanon: Prevalence, Consequences and Associated Factors.

    Directory of Open Access Journals (Sweden)

    Mohamad Alameddine

    Full Text Available Healthcare institutions have commonly reported exposure of employees, particularly nurses, to high levels of occupational violence. Despite such evidence in the Middle East Region, there is a dearth of national studies that have systematically investigated this phenomenon. This study investigates the prevalence, characteristics, consequences and factors associated with nurses' exposure to occupational violence in Lebanon.A cross-sectional design was utilized to survey a nationally representative sample of 915 nurses registered with the Order of Nurses in Lebanon. Stratified random sampling by governorate was utilized. Individually-mailed questionnaires collected information on exposure to violence, degree of burnout and demographic/professional background. The main outcome variables were exposure to verbal abuse (never, 1-3, 4-9 and 10+ times and physical violence (never, ever over the past 12-months. Descriptive statistics were used to estimate prevalence of violence. Multivariable, binomial and multinomial regression models were carried out to investigate the correlates of exposure to verbal abuse and physical violence, respectively.Response rate was 64.8%. Over the last year, prevalence of nurses' exposure to verbal abuse was 62%, (CI: 58-65% and physical violence was 10%, (CI: 8-13%. Among respondents, 31.7% of nurses indicated likelihood to quit their jobs and 22.3% were undetermined. Furthermore, 54.1% reported high levels of emotional exhaustion and 28.8% reported high levels of depersonalization. Compared to nurses with no exposure to verbal abuse, nurses reporting high exposure had high levels of emotional exhaustion (OR:6.4; CI:1.76-23.32, depersonalization (OR:6.8; CI: 3-15 and intention to quit job (OR:3.9; CI: 1.8-8.3. They further reported absence of anti-violence policies at their institutions (OR: 3; CI: 1.5-6.3. Nurses that were ever exposed to physical violence were more likely to be males (OR: 2.2; CI: 1.1-4.3, working day and

  1. Hidden temporal order unveiled in stock market volatility variance

    Directory of Open Access Journals (Sweden)

    Y. Shapira

    2011-06-01

    Full Text Available When analyzed by standard statistical methods, the time series of the daily return of financial indices appear to behave as Markov random series with no apparent temporal order or memory. This empirical result seems to be counter intuitive since investor are influenced by both short and long term past market behaviors. Consequently much effort has been devoted to unveil hidden temporal order in the market dynamics. Here we show that temporal order is hidden in the series of the variance of the stocks volatility. First we show that the correlation between the variances of the daily returns and means of segments of these time series is very large and thus cannot be the output of random series, unless it has some temporal order in it. Next we show that while the temporal order does not show in the series of the daily return, rather in the variation of the corresponding volatility series. More specifically, we found that the behavior of the shuffled time series is equivalent to that of a random time series, while that of the original time series have large deviations from the expected random behavior, which is the result of temporal structure. We found the same generic behavior in 10 different stock markets from 7 different countries. We also present analysis of specially constructed sequences in order to better understand the origin of the observed temporal order in the market sequences. Each sequence was constructed from segments with equal number of elements taken from algebraic distributions of three different slopes.

  2. Assessment of Human Exposure to ENMs.

    Science.gov (United States)

    Jiménez, Araceli Sánchez; van Tongeren, Martie

    2017-01-01

    Human exposure assessment of engineered nanomaterials (ENMs) is hampered, among other factors, by the difficulty to differentiate ENM from other nanomaterials (incidental to processes or naturally occurring) and the lack of a single metric that can be used for health risk assessment. It is important that the exposure assessment is carried out throughout the entire life-cycle as releases can occur at the different stages of the product life-cycle, from the synthesis, manufacture of the nano-enable product (occupational exposure) to the professional and consumer use of nano-enabled product (consumer exposure) and at the end of life.Occupational exposure surveys should follow a tiered approach, increasing in complexity in terms of instruments used and sampling strategy applied with higher tiers in order tailor the exposure assessment to the specific materials used and workplace exposure scenarios and to reduce uncertainty in assessment of exposure. Assessment of consumer exposure and of releases from end-of-life processes currently relies on release testing of nano-enabled products in laboratory settings.

  3. Dioxin Exposure Initiative

    Science.gov (United States)

    The Dioxin Exposure Initiative (DEI) is no longer active. This page contains a summary of the dioxin exposure initiative with illustrations, contact and background information.Originally supported by scientist Matthew Lorber, who retired in Mar 2017.

  4. Exposure scenarios for workers

    NARCIS (Netherlands)

    Marquart, H.; Northage, C.; Money, C.

    2007-01-01

    The new European chemicals legislation REACH (Registration, Evaluation, Authorisation and restriction of Chemicals) requires the development of Exposure Scenarios describing the conditions and risk management measures needed for the safe use of chemicals. Such Exposure Scenarios should integrate

  5. Left truncation results in substantial bias of the relation between time-dependent exposures and adverse events

    NARCIS (Netherlands)

    Hazelbag, Christijan M; Klungel, Olaf H; van Staa, Tjeerd P; de Boer, Anthonius; Groenwold, Rolf H H

    PURPOSE: To assess the impact of random left truncation of data on the estimation of time-dependent exposure effects. METHODS: A simulation study was conducted in which the relation between exposure and outcome was based on an immediate exposure effect, a first-time exposure effect, or a cumulative

  6. Left truncation results in substantial bias of the relation between time-dependent exposures and adverse events

    NARCIS (Netherlands)

    Hazelbag, Christijan M.; Klungel, Olaf H.; van Staa, Tjeerd P.; de Boer, Anthonius; Groenwold, Rolf H H

    2015-01-01

    PURPOSE: To assess the impact of random left truncation of data on the estimation of time-dependent exposure effects. METHODS: A simulation study was conducted in which the relation between exposure and outcome was based on an immediate exposure effect, a first-time exposure effect, or a cumulative

  7. Aggressive Orders and the Resiliency of a Limit Order Market

    NARCIS (Netherlands)

    Degryse, H.A.; de Jong, F.C.J.M.; van Ravenswaaij, M.; Wuyts, G.

    2002-01-01

    We analyze the resiliency of a pure limit order market for large and small capitalization stocks as well as stocks with different tick sizes.We explore the issue of resiliency by investigating the order flow around aggressive orders that move prices.The impact of aggressive orders is gauged in three

  8. Virtual reality exposure therapy

    OpenAIRE

    Rothbaum, BO; Hodges, L; Kooper, R

    1997-01-01

    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

  9. Occupational exposures. Annex H

    International Nuclear Information System (INIS)

    1982-01-01

    This Annex focuses on significant changes in the pattern of occupational exposure which have appeared since the 1972 and 1962 reports, and presents information on trends or particular causes of high exposures. A further objective is to clarify the reasons for which the Committee requires data on occupational exposure, and to suggest areas in which better data collection or analysis may be performed. Data are also reviewed on accidents involving the exposure of workers to substantial radiation doses.

  10. Natural radiation exposure indoors

    International Nuclear Information System (INIS)

    Brown, L.; Cliff, K.D.; Wrixon, A.D.

    1981-01-01

    A brief review is presented of the state of knowledge of indoor natural radiation exposure in the U.K. and the current survey work the N.R.P.B. is carrying out in this field. Discussion is limited in this instance to the improvement in estimation of population exposure and the identification of areas and circumstances in which high exposure occur, rather than the study of properties of a building and methods of building affecting exposure to radiation. (U.K.)

  11. A Technique: Exposure Therapy

    Directory of Open Access Journals (Sweden)

    Serkan AKKOYUNLU

    2013-07-01

    Full Text Available Introduction: Exposure with response prevention is an effective treatment for all anxiety disorders. According to the behavioral learning theories, fears which are conditioned via classical conditioning are reinforced by respondent conditioning. Avoidance and safety seeking behaviors prevent disconfirmation of anxious beliefs. In exposure client faces stimulates or cues that elicit fear or distress, by this avoidance is inhibited. Clients are also encouraged to resists performing safety seeking behaviors or rituals that they utilize to reduce fear or distress. Accomplishing these habituation or extinction is achieved. In addition to this clients learn that feared consequences does not realize or not harmful as they believed by experiencing. Emotional processing is believed to be the mechanism of change in exposure.Objective: The aim of this review is to provide a definition of exposure and its effectiveness briefly, and describe how to implement exposure, its steps and remarkable aspects using. Exposure therapies and treatments that involve exposure are proved to be effective in all anxiety disorders. Exposure therapy can be divided in three parts: Assessment and providing a treatment rationale, creating an exposure hierarchy and response prevention plan, implementing exposure sessions. Clients must also continue to perform exposure between sessions. Therapy transcripts are also provided to exemplify these parts. Conclusion: Exposure with response prevention is a basic and effective technique. Every cognitive behavior therapist must be able to implement this technique and be cognizant of pearls of this procedure.

  12. Radiation exposure records management

    International Nuclear Information System (INIS)

    Boiter, H.P.

    1975-12-01

    Management of individual radiation exposure records begins at employment with the accumulation of data pertinent to the individual and any previous occupational radiation exposure. Appropriate radiation monitorinng badges or devices are issued and accountability established. A computer master file is initiated to include the individual's name, payroll number, social security number, birth date, assigned department, and location. From this base, a radiation exposure history is accumulated to include external ionizing radiation exposure to skin and whole body, contributing neutron exposure, contributing tritium exposure, and extremity exposure. It is used also to schedule bioassay sampling and in-vivo counts and to provide other pertinent information. The file is used as a basis for providing periodic reports to management and monthly exposure summaries to departmental line supervision to assist in planning work so that individual annual exposures are kept as low as practical. Radiation exposure records management also includes documentation of radiation surveys performed by the health physicist to establish working rates and the individual estimating and recording his estimated exposure on a day-to-day basis. Exposure information is also available to contribute to Energy Research and Development Administration statistics and to the National Transuranium Registry

  13. Assessment of human exposures

    Energy Technology Data Exchange (ETDEWEB)

    Lebret, E [RIVM-National Inst. of Public Health and Environmental Protection (Netherlands)

    1996-12-31

    This article describes some of the features of the assessment of human exposure to environmental pollutants in epidemiological studies. Since exposure assessment in air pollution epidemiology studies typically involve professionals from various backgrounds, interpretation of a concepts like `exposure` may vary. A brief descriptions is therefore given by way of introduction

  14. Assessment of human exposures

    Energy Technology Data Exchange (ETDEWEB)

    Lebret, E. [RIVM-National Inst. of Public Health and Environmental Protection (Netherlands)

    1995-12-31

    This article describes some of the features of the assessment of human exposure to environmental pollutants in epidemiological studies. Since exposure assessment in air pollution epidemiology studies typically involve professionals from various backgrounds, interpretation of a concepts like `exposure` may vary. A brief descriptions is therefore given by way of introduction

  15. Virtual reality exposure therapy for social phobia

    OpenAIRE

    Herbelin, Bruno

    2005-01-01

    This thesis presents researches and experiments performed in collaboration with a psychiatrist in order to validate and improve the use of virtual reality in social phobia psychotherapy. Cognitive and behavioral therapies are strongly based on the exposure to anxiety provoking stimuli. Virtual reality seems to be appropriate for such exposures as it allows for on-demand reproduction of reality. The idea has been validated for the treatment of various phobias but is more delicate in the case o...

  16. Randomizer for High Data Rates

    Science.gov (United States)

    Garon, Howard; Sank, Victor J.

    2018-01-01

    NASA as well as a number of other space agencies now recognize that the current recommended CCSDS randomizer used for telemetry (TM) is too short. When multiple applications of the PN8 Maximal Length Sequence (MLS) are required in order to fully cover a channel access data unit (CADU), spectral problems in the form of elevated spurious discretes (spurs) appear. Originally the randomizer was called a bit transition generator (BTG) precisely because it was thought that its primary value was to insure sufficient bit transitions to allow the bit/symbol synchronizer to lock and remain locked. We, NASA, have shown that the old BTG concept is a limited view of the real value of the randomizer sequence and that the randomizer also aids in signal acquisition as well as minimizing the potential for false decoder lock. Under the guidelines we considered here there are multiple maximal length sequences under GF(2) which appear attractive in this application. Although there may be mitigating reasons why another MLS sequence could be selected, one sequence in particular possesses a combination of desired properties which offsets it from the others.

  17. Chaos, complexity, and random matrices

    Science.gov (United States)

    Cotler, Jordan; Hunter-Jones, Nicholas; Liu, Junyu; Yoshida, Beni

    2017-11-01

    Chaos and complexity entail an entropic and computational obstruction to describing a system, and thus are intrinsically difficult to characterize. In this paper, we consider time evolution by Gaussian Unitary Ensemble (GUE) Hamiltonians and analytically compute out-of-time-ordered correlation functions (OTOCs) and frame potentials to quantify scrambling, Haar-randomness, and circuit complexity. While our random matrix analysis gives a qualitatively correct prediction of the late-time behavior of chaotic systems, we find unphysical behavior at early times including an O(1) scrambling time and the apparent breakdown of spatial and temporal locality. The salient feature of GUE Hamiltonians which gives us computational traction is the Haar-invariance of the ensemble, meaning that the ensemble-averaged dynamics look the same in any basis. Motivated by this property of the GUE, we introduce k-invariance as a precise definition of what it means for the dynamics of a quantum system to be described by random matrix theory. We envision that the dynamical onset of approximate k-invariance will be a useful tool for capturing the transition from early-time chaos, as seen by OTOCs, to late-time chaos, as seen by random matrix theory.

  18. Quantum random walks using quantum accelerator modes

    International Nuclear Information System (INIS)

    Ma, Z.-Y.; Burnett, K.; D'Arcy, M. B.; Gardiner, S. A.

    2006-01-01

    We discuss the use of high-order quantum accelerator modes to achieve an atom optical realization of a biased quantum random walk. We first discuss how one can create coexistent quantum accelerator modes, and hence how momentum transfer that depends on the atoms' internal state can be achieved. When combined with microwave driving of the transition between the states, a different type of atomic beam splitter results. This permits the realization of a biased quantum random walk through quantum accelerator modes

  19. Random clustering ferns for multimodal object recognition

    OpenAIRE

    Villamizar Vergel, Michael Alejandro; Garrell Zulueta, Anais; Sanfeliu Cortés, Alberto; Moreno-Noguer, Francesc

    2017-01-01

    The final publication is available at link.springer.com We propose an efficient and robust method for the recognition of objects exhibiting multiple intra-class modes, where each one is associated with a particular object appearance. The proposed method, called random clustering ferns, combines synergically a single and real-time classifier, based on the boosted assembling of extremely randomized trees (ferns), with an unsupervised and probabilistic approach in order to recognize efficient...

  20. Gamma radiographic exposure time indicator

    International Nuclear Information System (INIS)

    Risbud, V.H.; Thiagarajan, A.; Gangadharan, P.

    1979-01-01

    In industrial radiography, with the proper selection of source and film, the radiographic quality depends very much on the exposure time, which in turn depends upon the source strength and the source to film distance. Conventional methods to arrive at correct exposure time involve time consuming calculations and in these methods the knowledge of the above mentioned parameters is imperative. An instrument to determine the required exposure time has been developed which indicates exposure times in about 30 secs. This covers two commonly used gamma radiography sources, viz., 192 Ir and 60 Co and six commonly used radiography films of different speeds. Knowledge of source strength and source to film distance is not required with the use of this instrument. With a knowledge of the total exposure required by the film to give the required sensitivity and by the measurement of radiation level at the film location, the correct exposure time is determined. The radiation level is measured by placing a GM counter behind the radiographic specimen at the film location. To match the responses of the film and the GM counter, the counter is incorporated in a suitably designed probe. In this instruments, an integrator to integrate the GM-pulses and a constant current integrator (timer) are started simultaneously. The voltage at the GM-pulse integrator is compared with a preselected voltage, (selected on the basis of film type, source, source strength and order of object thickness) by a comparator. The comparator is so adjusted that when the GM-pulse integrator voltage exceeds the preselected voltage, it switches its state and stops the integration of constant current. The constant current integrator output which is proportional to the time taken for the GM-pulse integrator to reach the preselected voltage, is read on a meter graduated in terms of exposure time. The instrument can measure exposure times from 5 minutes to 10 hours read in two ranges, the range-changing being automatic

  1. OCCUPATIONAL EXPOSURE AND COPD

    DEFF Research Database (Denmark)

    Würtz, Else Toft

    Chronic Obstructive Pulmonary Disease (COPD) is a common disease. The main risk factor is smoking although 15% of the COPD cases are expected to be preventable if the occupational exposures from vapour, gas, dust, and fume were eliminated; the population attributable fraction (PAF). The thesis...... addresses the association between occupational exposure and COPD in a population-based cohort of Danes aged 45-84-years. 4717 participants were included at baseline and 2624 at the four year follow-up. COPD was defined by spirometry and the occupational exposure was based on specialist defined jobs...... and questionnaires. The main occupational exposure was organic dust and 49% reported no lifetime occupational exposure. The results suggest occupational exposures to be associated to COPD also in never smokers and women. We found an exposure-response relation in the cross sectional analyses. The results...

  2. Predictors of monoterpene exposure in the Danish furniture industry.

    Science.gov (United States)

    Hagström, Katja; Jacobsen, Gitte; Sigsgaard, Torben; Schaumburg, Inger; Erlandsen, Mogens; Schlunssen, Vivi

    2012-04-01

    Individuals who work with pine in the furniture industry may be exposed to monoterpenes, the most abundant of which are α-pinene, β-pinene, and Δ(3)-carene. Monoterpenes are suspected to cause dermatitis and to harm the respiratory system. An understanding of the predictors of monoterpene exposure is therefore important in preventing these adverse effects. These predictors may include general characteristics of the work environment and specific work operations. We sought to assess the extent to which workers are exposed to monoterpenes and to identify possible predictors of monoterpene exposure in the pine furniture industry in Denmark. Passive measurements of the levels of selected monoterpenes (α-pinene, β-pinene, and Δ(3)-carene) were performed on 161 subjects from 17 pine furniture factories in Viborg County, Denmark; one sample was acquired from each worker. Additionally, wood dust samples were collected from 145 workers. Data on potential predictors of exposure were acquired over the course of the day on which the exposure measurements were recorded and could be assigned to one of four hierarchic ordered levels: worker, machine, department, and factory. In addition to univariate analyses, a mixed model was used to account for imbalances within the data and random variation with each of the hierarchically ordered levels. The geometric mean (GM) monoterpene content observed over the 161 measurements was 7.8 mg m(-3) [geometric standard deviation (GSD): 2.4]; the GM wood dust level over 145 measurements was 0.58 mg m(-3) (GSD: 1.49). None of the measured samples exceeded the occupational exposure limit for terpenes in Denmark (25 ppm, 150 mg m(-3)). In the univariate analyses, half of the predictors tested were found to be significant; the multivariate model indicated that only three of the potential predictors were significant. These were the recirculation of air in rooms used for the processing of wood (a factory level predictor), the presence of a

  3. On a randomly imperfect spherical cap pressurized by a random ...

    African Journals Online (AJOL)

    On a randomly imperfect spherical cap pressurized by a random dynamic load. ... In this paper, we investigate a dynamical system in a random setting of dual ... characterization of the random process for determining the dynamic buckling load ...

  4. Exposure to inequality affects support for redistribution.

    Science.gov (United States)

    Sands, Melissa L

    2017-01-24

    The distribution of wealth in the United States and countries around the world is highly skewed. How does visible economic inequality affect well-off individuals' support for redistribution? Using a placebo-controlled field experiment, I randomize the presence of poverty-stricken people in public spaces frequented by the affluent. Passersby were asked to sign a petition calling for greater redistribution through a "millionaire's tax." Results from 2,591 solicitations show that in a real-world-setting exposure to inequality decreases affluent individuals' willingness to redistribute. The finding that exposure to inequality begets inequality has fundamental implications for policymakers and informs our understanding of the effects of poverty, inequality, and economic segregation. Confederate race and socioeconomic status, both of which were randomized, are shown to interact such that treatment effects vary according to the race, as well as gender, of the subject.

  5. Exposure to inequality affects support for redistribution

    Science.gov (United States)

    Sands, Melissa L.

    2017-01-01

    The distribution of wealth in the United States and countries around the world is highly skewed. How does visible economic inequality affect well-off individuals’ support for redistribution? Using a placebo-controlled field experiment, I randomize the presence of poverty-stricken people in public spaces frequented by the affluent. Passersby were asked to sign a petition calling for greater redistribution through a “millionaire’s tax.” Results from 2,591 solicitations show that in a real-world-setting exposure to inequality decreases affluent individuals’ willingness to redistribute. The finding that exposure to inequality begets inequality has fundamental implications for policymakers and informs our understanding of the effects of poverty, inequality, and economic segregation. Confederate race and socioeconomic status, both of which were randomized, are shown to interact such that treatment effects vary according to the race, as well as gender, of the subject. PMID:28069960

  6. Blocked Randomization with Randomly Selected Block Sizes

    Directory of Open Access Journals (Sweden)

    Jimmy Efird

    2010-12-01

    Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

  7. Acute Exposure to Low-to-Moderate Carbon Dioxide Levels and Submariner Decision Making.

    Science.gov (United States)

    Rodeheffer, Christopher D; Chabal, Sarah; Clarke, John M; Fothergill, David M

    2018-06-01

    Submarines routinely operate with higher levels of ambient carbon dioxide (CO2) (i.e., 2000 - 5000 ppm) than what is typically considered normal (i.e., 400 - 600 ppm). Although significant cognitive impairments are rarely reported at these elevated CO2 levels, recent studies using the Strategic Management Simulation (SMS) test have found impairments in decision-making performance during acute CO2 exposure at levels as low as 1000 ppm. This is a potential concern for submarine operations, as personnel regularly make mission-critical decisions that affect the safety and efficiency of the vessel and its crew while exposed to similar levels of CO2. The objective of this study was to determine if submariner decision-making performance is impacted by acute exposure to levels of CO2 routinely present in the submarine atmosphere during sea patrols. Using a subject-blinded balanced design, 36 submarine-qualified sailors were randomly assigned to receive 1 of 3 CO2 exposure conditions (600, 2500, or 15,000 ppm). After a 45-min atmospheric acclimation period, participants completed an 80-min computer-administered SMS test as a measure of decision making. There were no significant differences for any of the nine SMS measures of decision making between the CO2 exposure conditions. In contrast to recent research demonstrating cognitive deficits on the SMS test in students and professional-grade office workers, we were unable to replicate this effect in a submariner population-even with acute CO2 exposures more than an order of magnitude greater than those used in previous studies that demonstrated such effects.Rodeheffer CD, Chabal S, Clarke JM, Fothergill DM. Acute exposure to low-to-moderate carbon dioxide levels and submariner decision making. Aerosp Med Hum Perform. 2018; 89(6):520-525.

  8. Random walks, random fields, and disordered systems

    CERN Document Server

    Černý, Jiří; Kotecký, Roman

    2015-01-01

    Focusing on the mathematics that lies at the intersection of probability theory, statistical physics, combinatorics and computer science, this volume collects together lecture notes on recent developments in the area. The common ground of these subjects is perhaps best described by the three terms in the title: Random Walks, Random Fields and Disordered Systems. The specific topics covered include a study of Branching Brownian Motion from the perspective of disordered (spin-glass) systems, a detailed analysis of weakly self-avoiding random walks in four spatial dimensions via methods of field theory and the renormalization group, a study of phase transitions in disordered discrete structures using a rigorous version of the cavity method, a survey of recent work on interacting polymers in the ballisticity regime and, finally, a treatise on two-dimensional loop-soup models and their connection to conformally invariant systems and the Gaussian Free Field. The notes are aimed at early graduate students with a mod...

  9. Order-sorted Algebraic Specifications with Higher-order Functions

    DEFF Research Database (Denmark)

    Haxthausen, Anne Elisabeth

    1995-01-01

    This paper gives a proposal for how order-sorted algebraic specification languages can be extended with higher-order functions. The approach taken is a generalisation to the order-sorted case of an approach given by Mller, Tarlecki and Wirsing for the many-sorted case. The main idea in the proposal...

  10. Order Quantity Distributions in Make-to-Order Manufacturing

    DEFF Research Database (Denmark)

    Eriksen, Poul Svante; Nielsen, Peter

    2011-01-01

    and control with a special emphasis on the make-to-order environment is presented. A methodological framework for analyzing the behavior of orders and investigate the validity of the assumptions is given. Furthermore, an analytical approach to identify the horizon needed for aggregating orders to achieve...

  11. Mechanical properties of ordered alloys

    International Nuclear Information System (INIS)

    Kroupa, F.

    1977-06-01

    A survey is given of the metallophysical fundamentals of the mechanical properties of ordered two-phase alloys. Alloys of this type have a superlattice structure in a substitution mixed crystal. Ordering is achieved by slow cooling or by annealing below the critical temperature, during which ordering domains (antiphase domains) are formed. At a high degree of ordering, the dislocations are concentrated to form pairs, so-called super-dislocations. The mechanical properties may be selectively changed by varying different parameters (size of the ordering domains, degree of ordering, energy of the antiphase boundaries) by a special composition and heat treatment.(GSC) [de

  12. Media and youth: access, exposure, and privatization.

    Science.gov (United States)

    Roberts, D F

    2000-08-01

    To describe U.S. youth's access and exposure to the full array of media, as well as the social contexts in which media exposure occurs. A cross-sectional national random sample of 2065 adolescents aged 8 through 18 years, including oversamples of African-American and Hispanic youth, completed questionnaires about use of television, videotapes, movies, computers, video games, radio, compact discs, tape players, books, newspapers, and magazines. U.S. youngsters are immersed in media. Most households contain most media (computers and video game systems are the exception); the majority of youth have their own personal media. The average youth devotes 6 3/4 h to media; simultaneous use of multiple media increases exposure to 8 h of media messages daily. Overall, media exposure and exposure to individual media vary as a function of age, gender, race/ethnicity, and family socioeconomic level. Television remains the dominant medium. About one-half of the youth sampled uses a computer daily. A substantial proportion of children's and adolescents' media use occurs in the absence of parents. American youth devote more time to media than to any other waking activity, as much as one-third of each day. This demands increased parental attention and research into the effects of such extensive exposure.

  13. Misuse of randomization

    DEFF Research Database (Denmark)

    Liu, Jianping; Kjaergard, Lise Lotte; Gluud, Christian

    2002-01-01

    The quality of randomization of Chinese randomized trials on herbal medicines for hepatitis B was assessed. Search strategy and inclusion criteria were based on the published protocol. One hundred and seventy-six randomized clinical trials (RCTs) involving 20,452 patients with chronic hepatitis B...... virus (HBV) infection were identified that tested Chinese medicinal herbs. They were published in 49 Chinese journals. Only 10% (18/176) of the studies reported the method by which they randomized patients. Only two reported allocation concealment and were considered as adequate. Twenty percent (30...

  14. Human biomonitoring of chromium and nickel from an experimental exposure to manual metal arc welding fumes of low and high alloyed steel.

    Science.gov (United States)

    Bertram, Jens; Brand, Peter; Schettgen, Thomas; Lenz, Klaus; Purrio, Ellwyn; Reisgen, Uwe; Kraus, Thomas

    2015-05-01

    The uptake and elimination of metals from welding fumes is currently not fully understood. In the Aachen Workplace Simulation Laboratory (AWSL) it is possible to investigate the impact of welding fumes on human subjects under controlled exposure conditions. In this study, the uptake and elimination of chromium or chromium (VI) respectively as well as nickel was studied in subjects after exposure to the emissions of a manual metal arc welding process using low or high alloyed steel. In this present study 12 healthy male non-smokers, who never worked as welders before, were exposed for 6h to welding fumes of a manual metal arc welding process. In a three-fold crossover study design, subjects were exposed in randomized order to either clean air, emissions from welding low alloyed steel, and emissions from welding high alloyed steel. Particle mass concentration of the exposure aerosol was 2.5mg m(-3). The content of chromium and nickel in the air was determined by analysing air filter samples on a high emission scenario. Urine analysis for chromium and nickel was performed before and after exposure using methods of human biomonitoring. There were significantly elevated chromium levels after exposure to welding fumes from high alloyed steel compared to urinary chromium levels before exposure to high alloyed welding fumes, as well as compared to the other exposure scenarios. The mean values increased from 0.27 µg l(-1) to 18.62 µg l(-1). The results were in good agreement with already existing correlations between external and internal exposure (German exposure equivalent for carcinogenic working materials EKA). The variability of urinary chromium levels was high. For urinary nickel no significant changes could be detected at all. Six-hour exposure to 2.5mg m(-3) high alloyed manual metal arc welding fumes lead to elevated urinary chromium levels far higher (7.11-34.16 µg l(-1)) than the German biological exposure reference value (BAR) of 0.6 µg l(-1) directly after

  15. The Effect of Uncertainty in Exposure Estimation on the Exposure-Response Relation between 1,3-Butadiene and Leukemia

    Directory of Open Access Journals (Sweden)

    George Maldonado

    2009-09-01

    Full Text Available Abstract: In a follow-up study of mortality among North American synthetic rubber industry workers, cumulative exposure to 1,3-butadiene was positively associated with leukemia. Problems with historical exposure estimation, however, may have distorted the association. To evaluate the impact of potential inaccuracies in exposure estimation, we conducted uncertainty analyses of the relation between cumulative exposure to butadiene and leukemia. We created the 1,000 sets of butadiene estimates using job-exposure matrices consisting of exposure values that corresponded to randomly selected percentiles of the approximate probability distribution of plant-, work area/job group-, and year specific butadiene ppm. We then analyzed the relation between cumulative exposure to butadiene and leukemia for each of the 1,000 sets of butadiene estimates. In the uncertainty analysis, the point estimate of the RR for the first non zero exposure category (>0–<37.5 ppm-years was most likely to be about 1.5. The rate ratio for the second exposure category (37.5–<184.7 ppm-years was most likely to range from 1.5 to 1.8. The RR for category 3 of exposure (184.7–<425.0 ppm-years was most likely between 2.1 and 3.0. The RR for the highest exposure category (425.0+ ppm-years was likely to be between 2.9 and 3.7. This range off RR point estimates can best be interpreted as a probability distribution that describes our uncertainty in RR point estimates due to uncertainty in exposure estimation. After considering the complete probability distributions of butadiene exposure estimates, the exposure-response association of butadiene and leukemia was maintained. This exercise was a unique example of how uncertainty analyses can be used to investigate and support an observed measure of effect when occupational exposure estimates are employed in the absence of direct exposure measurements.

  16. Birth Order and Child Health

    OpenAIRE

    Lundberg, Evelina; Svaleryd, Helena

    2017-01-01

    Previous research has established that birth order affects outcomes such as educational achievements, IQ and earnings. The mechanisms behind these effects are, however, still largely unknown. In this paper, we examine birth-order effects on health, and whether health at young age could be a transmission channel for birth-order effects observed later in life. We find no support for the birth-order effect having a biological origin; rather firstborns have worse health at birth. This disadvantag...

  17. Olson Order of Quantum Observables

    Science.gov (United States)

    Dvurečenskij, Anatolij

    2016-11-01

    M.P. Olson, Proc. Am. Math. Soc. 28, 537-544 (1971) showed that the system of effect operators of the Hilbert space can be ordered by the so-called spectral order such that the system of effect operators is a complete lattice. Using his ideas, we introduce a partial order, called the Olson order, on the set of bounded observables of a complete lattice effect algebra. We show that the set of bounded observables is a Dedekind complete lattice.

  18. With or without pheromone habituation: possible differences between insect orders?

    Science.gov (United States)

    Suckling, David Maxwell; Stringer, Lloyd D; Jiménez-Pérez, Alfredo; Walter, Gimme H; Sullivan, Nicola; El-Sayed, Ashraf M

    2018-06-01

    Habituation to sex pheromones is one of the key mechanisms in mating disruption, an insect control tactic. Male moths often show reduced sexual response after pre-exposure to female sex pheromone. Mating disruption is relatively rare in insect orders other than Lepidoptera. As a positive control we confirmed habituation in a moth (Epiphyas postvittana) using 24 h pre-exposure to sex pheromone to reduce subsequent activation behaviour. We then tested the impact of pre-exposure to sex or trail pheromone on subsequent behavioural response with insects from three other orders. Similar pre-exposure for 24 h to either sex pheromone [Pseudococcus calceolariae (Homoptera) and apple leaf curling midge Dasineura mali (Diptera), or trail pheromone of Argentine ants (Linepithema humile (Hymenoptera)], followed by behavioural assay in clean air provided no evidence of habituation after pre-exposure in these latter cases. The moths alone were affected by pre-exposure to pheromone. For pests without habituation, sustained attraction to a point source may make lure and kill more economical. Improved knowledge of behavioural processes should lead to better success in pest management and mechanisms should be investigated further to inform studies and practical efforts generally enhancing effectiveness of pheromone-based management. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  19. [Occupational exposure to nanoparticles. Assessment of workplace exposure].

    Science.gov (United States)

    Bujak-Pietrek, Stella

    2010-01-01

    Nanotechnology is currently one of the most popular branch of science. It is a technology that enables designing, manufacturing and application of materials and structures of very small dimensions, and its products are applied in almost every field of life. Nanoparticles are the structures having one or more dimensions of the order of 100 nm or less. They are used in precise mechanics, electronics, optics, medicine, pharmacy, cosmetics and many other spheres. Due to their very small size, nanostructures have completely different and specific properties, unknown for the bulk of materials. Fast-growing nanotechnology provides a wide spectrum of applications, but it also brings about new and unknown danger to human health. Nanotechnology is the branch that has developed rather recently, and much information about health risk and its influence on the environment is beyond our knowledge. Nanoparticles, released in many technological processes, as well as manufactured nanoparticles can induce occupational hazards to workers. The lack of regulations and standards, compulsory in the manufacture and use ofnanoparticles is a fundamental problem faced in the evaluation of exposure. Another problem is the choice of proper measurement equipment for surveying of very small particles - their number, mass and surface area in the workpost air. In this article, the possibility and scope of exposure assessment is discussed and a brief specification of available instrumentation for counting and assessing the parameters essential for classifying the exposure to nanoparticles is presented.

  20. Order Theory in Environmental Sciences

    DEFF Research Database (Denmark)

    Sørensen, P. B.; Brüggemann, R.; Lerche, D. B.

    This is the proceeding from the fifth workshop in Order Theory in Environ-mental Science. In this workshop series the concept of Partial Order Theory is development in relation to application and the use is tested based on specific problems. The Partial Order Theory will have a potential use...

  1. Archimedeanization of ordered vector spaces

    OpenAIRE

    Emelyanov, Eduard Yu.

    2014-01-01

    In the case of an ordered vector space with an order unit, the Archimedeanization method has been developed recently by V.I Paulsen and M. Tomforde. We present a general version of the Archimedeanization which covers arbitrary ordered vector spaces.

  2. Monitoring of radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service.

  3. Monitoring of radiation exposure

    International Nuclear Information System (INIS)

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service

  4. Warehouse Order-Picking Process. Review

    Directory of Open Access Journals (Sweden)

    E. V. Korobkov

    2015-01-01

    Full Text Available This article describes basic warehousing activities, namely: movement, information storage and transfer, as well as connections between typical warehouse operations (reception, transfer, assigning storage position and put-away, order-picking, hoarding and sorting, cross-docking, shipping. It presents a classification of the warehouse order-picking systems in terms of manual labor on offer as well as external (marketing channels, consumer’s demand structure, supplier’s replenishment structure and inventory level, total production demand, economic situation and internal (mechanization level, information accessibility, warehouse dimensionality, method of dispatch for shipping, zoning, batching, storage assignment method, routing method factors affecting the designing systems complexity. Basic optimization considerations are described. There is a literature review on the following sub-problems of planning and control of orderpicking processes.A layout design problem has been taken in account at two levels — external (facility layout problem and internal (aisle configuration problem. For a problem of distributing goods or stock keeping units the following methods are emphasized: random, nearest open storage position, and dedicated (COI-based, frequency-based distribution, as well as class-based and familygrouped (complimentary- and contact-based one. Batching problem can be solved by two main methods, i.e. proximity order batching (seed and saving algorithms and time-window order batching. There are two strategies for a zoning problem: progressive and synchronized, and also a special case of zoning — bucket brigades method. Hoarding/sorting problem is briefly reviewed. Order-picking routing problem will be thoroughly described in the next article of the cycle “Warehouse order-picking process”.

  5. Wood smoke in a controlled exposure experiment with human volunteers

    DEFF Research Database (Denmark)

    Riddervold, Ingunn Skogstad; Bønløkke, Jakob Hjort; Mølhave, Lars

    2011-01-01

    Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung...... function and normal bronchial reactivity were randomly exposed for 3h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m3 (low) and 400 µg/m3 (high) under controlled environmental conditions.......0007), “irritative body perceptions” (p = 0.0127), “psychological/neurological effects” (p = 0.0075) and “weak inflammatory responses” (p = 0.0003). Furthermore, significant effects (p = 0.0192) on self-reported general mucosa irritation were found. In conclusion, exposure to wood smoke affected symptom rating...

  6. Evidence of significant bias in an elementary random number generator

    International Nuclear Information System (INIS)

    Borgwaldt, H.; Brandl, V.

    1981-03-01

    An elementary pseudo random number generator for isotropically distributed unit vectors in 3-dimensional space has ben tested for bias. This generator uses the IBM-suplied routine RANDU and a transparent rejection technique. The tests show clearly that non-randomness in the pseudo random numbers generated by the primary IBM generator leads to bias in the order of 1 percent in estimates obtained from the secondary random number generator. FORTRAN listings of 4 variants of the random number generator called by a simple test programme and output listings are included for direct reference. (orig.) [de

  7. Ordered delinquency: the "effects" of birth order on delinquency.

    Science.gov (United States)

    Cundiff, Patrick R

    2013-08-01

    Juvenile delinquency has long been associated with birth order in popular culture. While images of the middle child acting out for attention or the rebellious youngest child readily spring to mind, little research has attempted to explain why. Drawing from Adlerian birth order theory and Sulloway's born-to-rebel hypothesis, I examine the relationship between birth order and a variety of delinquent outcomes during adolescence. Following some recent research on birth order and intelligence, I use new methods that allow for the examination of between-individual and within-family differences to better address the potential spurious relationship. My findings suggest that contrary to popular belief, the relationship between birth order and delinquency is spurious. Specifically, I find that birth order effects on delinquency are spurious and largely products of the analytic methods used in previous tests of the relationship. The implications of this finding are discussed.

  8. Using exposure windows to explore an elusive biomarker: blood manganese.

    Science.gov (United States)

    Baker, Marissa G; Stover, Bert; Simpson, Christopher D; Sheppard, Lianne; Seixas, Noah S

    2016-05-01

    We sought to understand the time course between exposure to manganese (Mn) and uptake into the blood, to allow a more meaningful interpretation of exposure biomarker data, and to determine the utility of blood as a biomarker of Mn exposure. Welder trainees were monitored over the course of a five-quarter training program. Each quarter, trainees gave eight blood samples and had personal air monitoring four times. A mixed model was fit to obtain estimates of airborne exposure by welding type (fixed effect), adjusted for subject (random effect). Considering weekends and days absent as zero exposure, estimated exposures were summed over various exposure windows and related to measured blood manganese (MnB) using a mixed model. A relationship consistent with zero was found between MnB and modeled 1 or 7 days of exposure. After 30 days of preceding exposure, a 1 mg-days/m(3) increase in air Mn is associated with a 0.57 ng/mL increase in MnB (95% CI -0.04, 1.19). Considering a 90-day exposure window and a cumulative exposure window, a 1 mg-days/m(3) increase in air Mn is associated with a 0.26 (95% CI 0.005, 0.51) and 0.09 (95% CI 0.006, 0.17) ng/mL increase in MnB, respectively. From this analysis, MnB may begin to act as a biomarker of Mn exposure over longer time periods, or at higher levels of exposure. This novel study design allowed investigation of how MnB relates to different time windows of exposure, representing the most robust Mn exposure assessment in the biomarker literature.

  9. Random surfaces and strings

    International Nuclear Information System (INIS)

    Ambjoern, J.

    1987-08-01

    The theory of strings is the theory of random surfaces. I review the present attempts to regularize the world sheet of the string by triangulation. The corresponding statistical theory of triangulated random surfaces has a surprising rich structure, but the connection to conventional string theory seems non-trivial. (orig.)

  10. Derandomizing from random strings

    NARCIS (Netherlands)

    Buhrman, H.; Fortnow, L.; Koucký, M.; Loff, B.

    2010-01-01

    In this paper we show that BPP is truth-table reducible to the set of Kolmogorov random strings R(K). It was previously known that PSPACE, and hence BPP is Turing-reducible to R(K). The earlier proof relied on the adaptivity of the Turing-reduction to find a Kolmogorov-random string of polynomial

  11. Competition for order flow and smart order routing systems

    OpenAIRE

    Foucault, Thierry; Menkveld, Albert

    2006-01-01

    We study changes in liquidity following the introduction of a new electronic limit order market when, prior to its introduction, trading is centralized in a single limit order market. We also study how automation of routing decisions and trading fees affect the relative liquidity of rival markets. The theoretical analysis yields three main predictions: (i) consolidated depth is larger in the multiple limit order markets environment, (ii) consolidated bid-ask spread is smaller in the multiple ...

  12. Dow's chemical exposure index guide

    International Nuclear Information System (INIS)

    Marshall, J.T.; Mundt, A.

    1995-01-01

    A number of events in the 1970's and 1980's impacted the course of process safety. Incidents such as Flixborough, Seveso, Three-Mile Island, and Bhopal are well known throughout industry and are recognized as examples of major disasters. Even though events leading up to these disasters were completely different they had one common element between them: a substance was released from a manufacturing unit, became airborne and presented a hazard of such magnitude as to place the safety of both employees and the surrounding public in jeopardy. As a result, industry became increasingly concerned regarding potential loss, in human and economic terms, as plants and equipment grew in size. The Flixborough incident raised the level of concern for process safety, particularly in terms of the hazards presented by fire and explosion. Seveso and Three-Mile Island emphasized the need to consider far-field exposure. The Bhopal incident created an urgent need to recognize and understand the expected downwind impact of potential releases of acutely toxic substances to the air. In order to meet this need, the Dow Chemical Company, a recognized leader in the area of safety and loss prevention, presented a Chemical Exposure Index in 1986. AIChE has recently published an updated version entitled Dow's Chemical Exposure Index Guide. 7 refs., 5 figs

  13. Random-site cation ordering and dielectric properties of PbMg.sub.1/3./sub.Nb.sub.2./3./sub.O.sub.3./sub.-PbSc.sub.1/2./sub.Nb.sub.1/2./sub.O.sub.3./sub

    Czech Academy of Sciences Publication Activity Database

    Raevski, I. P.; Prosandeev, S. A.; Emelyanov, S. M.; Savenko, F. I.; Zakharchenko, I. N.; Bunina, O. A.; Bogatin, A. S.; Raevskaya, S. I.; Sahkar, E. V.; Jastrabík, Lubomír

    2003-01-01

    Roč. 53, - (2003), s. 475-487 ISSN 1058-4587 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010914 Keywords : cation ordering * dielectric properties * relaxors Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.608, year: 2003

  14. Quantum random number generator

    Science.gov (United States)

    Soubusta, Jan; Haderka, Ondrej; Hendrych, Martin

    2001-03-01

    Since reflection or transmission of a quantum particle on a beamsplitter is inherently random quantum process, a device built on this principle does not suffer from drawbacks of neither pseudo-random computer generators or classical noise sources. Nevertheless, a number of physical conditions necessary for high quality random numbers generation must be satisfied. Luckily, in quantum optics realization they can be well controlled. We present an easy random number generator based on the division of weak light pulses on a beamsplitter. The randomness of the generated bit stream is supported by passing the data through series of 15 statistical test. The device generates at a rate of 109.7 kbit/s.

  15. Quantum random number generator

    Science.gov (United States)

    Pooser, Raphael C.

    2016-05-10

    A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

  16. Birth order, neuroticism, and psychoticism among Iranian children.

    Science.gov (United States)

    Makaremi, A

    1992-12-01

    To investigate the effects of birth order, parents' education, and parents' occupation on four dimensions of the Junior Eysenck Personality Questionnaire, 262 elementary school students (100 boys and 162 girls) were selected randomly from four elementary schools in Shiraz. Analyses showed the main effects of birth order were significant on Neuroticism and Lie scales. Further, the effects of mothers' occupation on the Lie scale and fathers' education on the Neuroticism scale were significant.

  17. High Dynamic Range Imaging Using Multiple Exposures

    Science.gov (United States)

    Hou, Xinglin; Luo, Haibo; Zhou, Peipei; Zhou, Wei

    2017-06-01

    It is challenging to capture a high-dynamic range (HDR) scene using a low-dynamic range (LDR) camera. This paper presents an approach for improving the dynamic range of cameras by using multiple exposure images of same scene taken under different exposure times. First, the camera response function (CRF) is recovered by solving a high-order polynomial in which only the ratios of the exposures are used. Then, the HDR radiance image is reconstructed by weighted summation of the each radiance maps. After that, a novel local tone mapping (TM) operator is proposed for the display of the HDR radiance image. By solving the high-order polynomial, the CRF can be recovered quickly and easily. Taken the local image feature and characteristic of histogram statics into consideration, the proposed TM operator could preserve the local details efficiently. Experimental result demonstrates the effectiveness of our method. By comparison, the method outperforms other methods in terms of imaging quality.

  18. Perturbation Solutions for Random Linear Structural Systems subject to Random Excitation using Stochastic Differential Equations

    DEFF Research Database (Denmark)

    Köyluoglu, H.U.; Nielsen, Søren R.K.; Cakmak, A.S.

    1994-01-01

    perturbation method using stochastic differential equations. The joint statistical moments entering the perturbation solution are determined by considering an augmented dynamic system with state variables made up of the displacement and velocity vector and their first and second derivatives with respect......The paper deals with the first and second order statistical moments of the response of linear systems with random parameters subject to random excitation modelled as white-noise multiplied by an envelope function with random parameters. The method of analysis is basically a second order...... to the random parameters of the problem. Equations for partial derivatives are obtained from the partial differentiation of the equations of motion. The zero time-lag joint statistical moment equations for the augmented state vector are derived from the Itô differential formula. General formulation is given...

  19. Paternal Exposures and Pregnancy

    Science.gov (United States)

    ... increased risk for birth defects. Can the father’s workplace exposures affect my pregnancy? There have been a number of studies looking ... else could a father’s work exposure affect a pregnancy? Men exposed to ... chemicals in the workplace may carry these agents on their clothes and ...

  20. Exposure to natural radiation

    International Nuclear Information System (INIS)

    Green, B.M.R.

    1985-01-01

    A brief report is given of a seminar on the exposure to enhanced natural radiation and its regulatory implications held in 1985 at Maastricht, the Netherlands. The themes of the working sessions included sources of enhanced natural radiation, parameters influencing human exposure, measurement and survey programmes, technical countermeasures, risk and assessment studies, philosophies of dose limitations and national and international policies. (U.K.)

  1. Exposures of the elbow.

    Science.gov (United States)

    Axelrod, Terry S

    2014-11-01

    This article describes the basic bony, ligamentous, and neurologic anatomy of the structures about the elbow. The surgical exposures of the elbow joint are described, providing details of the various posterior, lateral, and medial approaches to the articular segments. Clinical applications describing the potential benefits of each surgical exposure are provided as examples. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Default settings of computerized physician order entry system order sets drive ordering habits.

    Science.gov (United States)

    Olson, Jordan; Hollenbeak, Christopher; Donaldson, Keri; Abendroth, Thomas; Castellani, William

    2015-01-01

    Computerized physician order entry (CPOE) systems are quickly becoming ubiquitous, and groups of orders ("order sets") to allow for easy order input are a common feature. This provides a streamlined mechanism to view, modify, and place groups of related orders. This often serves as an electronic equivalent of a specialty requisition. A characteristic, of these order sets is that specific orders can be predetermined to be "preselected" or "defaulted-on" whenever the order set is used while others are "optional" or "defaulted-off" (though there is typically the option is to "deselect" defaulted-on tests in a given situation). While it seems intuitive that the defaults in an order set are often accepted, additional study is required to understand the impact of these "default" settings in an order set on ordering habits. This study set out to quantify the effect of changing the default settings of an order set. For quality improvement purposes, order sets dealing with transfusions were recently reviewed and modified to improve monitoring of outcome. Initially, the order for posttransfusion hematocrits and platelet count had the default setting changed from "optional" to "preselected." The default settings for platelet count was later changed back to "optional," allowing for a natural experiment to study the effect of the default selections of an order set on clinician ordering habits. Posttransfusion hematocrit values were ordered for 8.3% of red cell transfusions when the default order set selection was "off" and for 57.4% of transfusions when the default selection was "preselected" (P default order set selection was "optional," increased to 59.4% when the default was changed to "preselected" (P default selection was returned to "optional." The posttransfusion platelet count rates during the two "optional" periods: 7.0% versus 7.5% - were not statistically different (P = 0.620). Default settings in CPOE order sets can significantly influence physician selection of

  3. Health protection guidelines for electromagnetic field exposures

    International Nuclear Information System (INIS)

    Taki, Masao

    1999-01-01

    In order to protect human health from excessive exposure to electromagnetic fields safety guidelines have been established by national and international organizations. The International Commission on Nonionization Radiation Protection is one of these organizations, whose guidelines are briefly regarded as typical. The activities on this issue in various countries are reviewed. Recent situations and the problems still unsolved are also discussed. (author)

  4. Self-reported acute health symptoms and exposure to companion animals

    Science.gov (United States)

    Background: In order to understand the etiological burden of disease associated with acute health symptoms (e.g. gastrointestinal [GI], respiratory, dermatological), it is important to understand how common exposures influence these symptoms. Exposures to familiar and unfamiliar ...

  5. Radiation camera exposure control

    International Nuclear Information System (INIS)

    Martone, R.J.; Yarsawich, M.; Wolczek, W.

    1976-01-01

    A system and method for governing the exposure of an image generated by a radiation camera to an image sensing camera is disclosed. The exposure is terminated in response to the accumulation of a predetermined quantity of radiation, defining a radiation density, occurring in a predetermined area. An index is produced which represents the value of that quantity of radiation whose accumulation causes the exposure termination. The value of the predetermined radiation quantity represented by the index is sensed so that the radiation camera image intensity can be calibrated to compensate for changes in exposure amounts due to desired variations in radiation density of the exposure, to maintain the detectability of the image by the image sensing camera notwithstanding such variations. Provision is also made for calibrating the image intensity in accordance with the sensitivity of the image sensing camera, and for locating the index for maintaining its detectability and causing the proper centering of the radiation camera image

  6. Changes in serum 25-hydroxyvitamin D and cholecalciferol after one whole-body exposure in a commercial tanning bed

    DEFF Research Database (Denmark)

    Langdahl, Jacob H; Schierbeck, Louise Lind; Bang, Ulrich Christian

    2012-01-01

    We wanted to evaluate the cutaneous synthesis of 25OHD and cholecalciferol after one whole-body exposure to ultraviolet radiation type B (UVB) in a randomized setup. Healthy volunteers were randomized to one whole-body exposure in a commercial tanning bed with UVB emission (UVB/UVA ratio 1...

  7. Universal medium-range order of amorphous metal oxides.

    Science.gov (United States)

    Nishio, Kengo; Miyazaki, Takehide; Nakamura, Hisao

    2013-10-11

    We propose that the structure of amorphous metal oxides can be regarded as a dual-dense-random-packing structure, which is a superposition of the dense random packing of metal atoms and that of oxygen atoms. Our ab initio molecular dynamics simulations show that the medium-range order of amorphous HfO2, ZrO2, TiO2, In2O3, Ga2O3, Al2O3, and Cu2O is characterized by the pentagonal-bipyramid arrangement of metal atoms and that of oxygen atoms, and prove the validity of our dual-random-sphere-packing model. In other words, we find that the pentagonal medium-range order is universal independent of type of metal oxide.

  8. On reflexivity of random walks in a random environment on a metric space

    International Nuclear Information System (INIS)

    Rozikov, U.A.

    2002-11-01

    In this paper, we consider random walks in random environments on a countable metric space when jumps of the walks of the fractions are finite. The transfer probabilities of the random walk from x is an element of G (where G is the considering metric space) are defined by vector p(x) is an element of R k , k>1, where {p(x), x is an element of G} is the set of independent and indentically distributed random vectors. For the random walk, a sufficient condition of nonreflexivity is obtained. Examples for metric spaces Z d free groups and free product of finite numbers cyclic groups of the second order and some other metric spaces are considered. (author)

  9. Counterbalancing for Serial Order Carryover Effects in Experimental Condition Orders

    Science.gov (United States)

    Brooks, Joseph L.

    2012-01-01

    Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed…

  10. Ordering within Moral Orders to Manage Classroom Trouble

    Science.gov (United States)

    Doherty, Catherine; McGregor, Rowena; Shield, Paul

    2016-01-01

    This paper demonstrates how classroom trouble warranting teacher intervention can stem from transgressions in different layers of the complex moral order regulating classroom interactions. The paper builds from Durkheim's treatment of schooling as the institution responsible for the inculcation of a shared moral order, Bernstein's distinction…

  11. Complete Normal Ordering 1: Foundations

    CERN Document Server

    Ellis, John; Skliros, Dimitri P.

    2016-01-01

    We introduce a new prescription for quantising scalar field theories perturbatively around a true minimum of the full quantum effective action, which is to `complete normal order' the bare action of interest. When the true vacuum of the theory is located at zero field value, the key property of this prescription is the automatic cancellation, to any finite order in perturbation theory, of all tadpole and, more generally, all `cephalopod' Feynman diagrams. The latter are connected diagrams that can be disconnected into two pieces by cutting one internal vertex, with either one or both pieces free from external lines. In addition, this procedure of `complete normal ordering' (which is an extension of the standard field theory definition of normal ordering) reduces by a substantial factor the number of Feynman diagrams to be calculated at any given loop order. We illustrate explicitly the complete normal ordering procedure and the cancellation of cephalopod diagrams in scalar field theories with non-derivative i...

  12. Substrate induced ordering of molecular adsorbates on Au(111)

    International Nuclear Information System (INIS)

    Schott, J.H.; White, H.S.; Arana, C.R.

    1992-01-01

    Using scanning tunneling microscopy in dimethylformate, [Ru(bpy) 2 (bpy-(CH 2 ) x -bpy) 2+ ] (x = 4 and 5) monolayers adsorbed on the unreconstructed and √3 x 22 reconstructed surfaces of Au(111) were imaged in this paper. The substrate had a highly ordered pattern on the reconstructed surface, but random spatial distribution on the unreconstructed surface. 17 refs., 3 figs

  13. Nonparametric Bayesian predictive distributions for future order statistics

    Science.gov (United States)

    Richard A. Johnson; James W. Evans; David W. Green

    1999-01-01

    We derive the predictive distribution for a specified order statistic, determined from a future random sample, under a Dirichlet process prior. Two variants of the approach are treated and some limiting cases studied. A practical application to monitoring the strength of lumber is discussed including choices of prior expectation and comparisons made to a Bayesian...

  14. Birth Order, Schooling, and Earnings.

    OpenAIRE

    Behrman, Jere R; Taubman, Paul

    1986-01-01

    Birth-order effects are posited by many to affect earnings and schooling. The authors show how such effects can be interpreted to shift either the earnings possibility frontier for siblings or parental preferences. The authors find empirical evidence for birth- order effects on (age-adjusted) schooling and on earnings for young U.S. adults, though the latter is not robust for all specifications. The examination of intrahousehold allocations suggests that these birth-order differences occur, d...

  15. Ordering variable for parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Zoltan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Soper, Davison E. [Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science

    2014-01-15

    The parton splittings in a parton shower are ordered according to an ordering variable, for example the transverse momentum of the daughter partons relative to the direction of the mother, the virtuality of the splitting, or the angle between the daughter partons. We analyze the choice of the ordering variable and conclude that one particular choice has the advantage of factoring softer splittings from harder splittings graph by graph in a physical gauge.

  16. Ordering variable for parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Zoltán [DESY,Notkestrasse 85, 22607 Hamburg (Germany); Soper, Davison E. [Institute of Theoretical Science, University of Oregon,Eugene, OR 97403-5203 (United States)

    2014-06-30

    The parton splittings in a parton shower are ordered according to an ordering variable, for example the transverse momentum of the daughter partons relative to the direction of the mother, the virtuality of the splitting, or the angle between the daughter partons. We analyze the choice of the ordering variable and conclude that one particular choice has the advantage of factoring softer splittings from harder splittings graph by graph in a physical gauge.

  17. Algorithms over partially ordered sets

    DEFF Research Database (Denmark)

    Baer, Robert M.; Østerby, Ole

    1969-01-01

    in partially ordered sets, answer the combinatorial question of how many maximal chains might exist in a partially ordered set withn elements, and we give an algorithm for enumerating all maximal chains. We give (in § 3) algorithms which decide whether a partially ordered set is a (lower or upper) semi......-lattice, and whether a lattice has distributive, modular, and Boolean properties. Finally (in § 4) we give Algol realizations of the various algorithms....

  18. Ordering variable for parton showers

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2014-01-01

    The parton splittings in a parton shower are ordered according to an ordering variable, for example the transverse momentum of the daughter partons relative to the direction of the mother, the virtuality of the splitting, or the angle between the daughter partons. We analyze the choice of the ordering variable and conclude that one particular choice has the advantage of factoring softer splittings from harder splittings graph by graph in a physical gauge.

  19. Liquid crystalline order in polymers

    CERN Document Server

    Blumstein, Alexandre

    1978-01-01

    Liquid Crystalline Order in Polymers examines the topic of liquid crystalline order in systems containing rigid synthetic macromolecular chains. Each chapter of the book provides a review of one important area of the field. Chapter 1 discusses scattering in polymer systems with liquid crystalline order. It also introduces the field of liquid crystals. Chapter 2 treats the origin of liquid crystalline order in macromolecules by describing the in-depth study of conformation of such macromolecules in their unassociated state. The chapters that follow describe successively the liquid crystalli

  20. Executive Orders-Barack Obama

    Data.gov (United States)

    National Archives and Records Administration — Executive orders are official documents, numbered consecutively, through which the President of the United States manages the operations of the Federal Government....

  1. Effects of mobility on ordering dynamics

    International Nuclear Information System (INIS)

    Baronchelli, Andrea; Pastor-Satorras, Romualdo

    2009-01-01

    Models of ordering dynamics allow us to understand natural systems in which an initially disordered population homogenizes some traits via local interactions. The simplest of these models, with wide applications ranging from evolutionary to social dynamics, are the Voter and Moran processes, usually defined in terms of static or randomly mixed individuals that interact with a neighbor to copy or modify a discrete trait. Here we study the effects of diffusion in Voter/Moran processes by proposing a generalization of ordering dynamics in a metapopulation framework, in which individuals are endowed with mobility and diffuse through a spatial structure represented as a graph of patches upon which interactions take place. We show that diffusion dramatically affects the time to reach the homogeneous state, independently of the underlying network's topology, while the final consensus emerges through different local/global mechanisms, depending on the mobility strength. Our results highlight the crucial role played by mobility in ordering processes and set up a general framework that allows its effect to be studied on a large class of models, with implications in the understanding of evolutionary and social phenomena. (letter)

  2. Hybrid reduced order modeling for assembly calculations

    International Nuclear Information System (INIS)

    Bang, Youngsuk; Abdel-Khalik, Hany S.; Jessee, Matthew A.; Mertyurek, Ugur

    2015-01-01

    Highlights: • Reducing computational cost in engineering calculations. • Reduced order modeling algorithm for multi-physics problem like assembly calculation. • Non-intrusive algorithm with random sampling. • Pattern recognition in the components with high sensitive and large variation. - Abstract: While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system.

  3. Hybrid reduced order modeling for assembly calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Youngsuk, E-mail: ysbang00@fnctech.com [FNC Technology, Co. Ltd., Yongin-si (Korea, Republic of); Abdel-Khalik, Hany S., E-mail: abdelkhalik@purdue.edu [Purdue University, West Lafayette, IN (United States); Jessee, Matthew A., E-mail: jesseema@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Mertyurek, Ugur, E-mail: mertyurek@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2015-12-15

    Highlights: • Reducing computational cost in engineering calculations. • Reduced order modeling algorithm for multi-physics problem like assembly calculation. • Non-intrusive algorithm with random sampling. • Pattern recognition in the components with high sensitive and large variation. - Abstract: While the accuracy of assembly calculations has considerably improved due to the increase in computer power enabling more refined description of the phase space and use of more sophisticated numerical algorithms, the computational cost continues to increase which limits the full utilization of their effectiveness for routine engineering analysis. Reduced order modeling is a mathematical vehicle that scales down the dimensionality of large-scale numerical problems to enable their repeated executions on small computing environment, often available to end users. This is done by capturing the most dominant underlying relationships between the model's inputs and outputs. Previous works demonstrated the use of the reduced order modeling for a single physics code, such as a radiation transport calculation. This manuscript extends those works to coupled code systems as currently employed in assembly calculations. Numerical tests are conducted using realistic SCALE assembly models with resonance self-shielding, neutron transport, and nuclides transmutation/depletion models representing the components of the coupled code system.

  4. Spatial serial order processing in schizophrenia.

    Science.gov (United States)

    Fraser, David; Park, Sohee; Clark, Gina; Yohanna, Daniel; Houk, James C

    2004-10-01

    The aim of this study was to examine serial order processing deficits in 21 schizophrenia patients and 16 age- and education-matched healthy controls. In a spatial serial order working memory task, one to four spatial targets were presented in a randomized sequence. Subjects were required to remember the locations and the order in which the targets were presented. Patients showed a marked deficit in ability to remember the sequences compared with controls. Increasing the number of targets within a sequence resulted in poorer memory performance for both control and schizophrenia subjects, but the effect was much more pronounced in the patients. Targets presented at the end of a long sequence were more vulnerable to memory error in schizophrenia patients. Performance deficits were not attributable to motor errors, but to errors in target choice. The results support the idea that the memory errors seen in schizophrenia patients may be due to saturating the working memory network at relatively low levels of memory load.

  5. Neurophysiological evidence that perceptions of fluency produce mere exposure effects.

    Science.gov (United States)

    Leynes, P Andrew; Addante, Richard J

    2016-08-01

    Recent exposure to people or objects increases liking ratings, the "mere exposure effect" (Zajonc in American Psychologist, 35, 117-123, 1968), and an increase in processing fluency has been identified as a potential mechanism for producing this effect. This fluency hypothesis was directly tested by altering the trial-by-trial image clarity (i.e., fluency) while Event-Related Potentials (ERPs) were recorded. In Experiment 1, clarity was altered across two trial blocks that each had homogenous trial-by-trial clarity, whereas clarity varied randomly across trials in Experiment 2. Blocking or randomizing image clarity across trials was expected to produce different levels of relative fluency and alter mere exposure effects. The mere exposure effect (i.e., old products liked more than new products) was observed when stimulus clarity remained constant across trials, and clear image ERPs were more positive than blurry image ERPs. Importantly, these patterns were reversed when clarity varied randomly across test trials, such that participants liked clear images more than blurry (i.e., no mere exposure effect) and clear image ERPs were more negative than blurry image ERPs. The findings provide direct experimental support from both behavioral and electrophysiological measures that, in some contexts, mere exposure is the product of top-down interpretations of fluency.

  6. Random number generation

    International Nuclear Information System (INIS)

    Coveyou, R.R.

    1974-01-01

    The subject of random number generation is currently controversial. Differing opinions on this subject seem to stem from implicit or explicit differences in philosophy; in particular, from differing ideas concerning the role of probability in the real world of physical processes, electronic computers, and Monte Carlo calculations. An attempt is made here to reconcile these views. The role of stochastic ideas in mathematical models is discussed. In illustration of these ideas, a mathematical model of the use of random number generators in Monte Carlo calculations is constructed. This model is used to set up criteria for the comparison and evaluation of random number generators. (U.S.)

  7. Quantum random access memory

    OpenAIRE

    Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo

    2007-01-01

    A random access memory (RAM) uses n bits to randomly address N=2^n distinct memory cells. A quantum random access memory (qRAM) uses n qubits to address any quantum superposition of N memory cells. We present an architecture that exponentially reduces the requirements for a memory call: O(log N) switches need be thrown instead of the N used in conventional (classical or quantum) RAM designs. This yields a more robust qRAM algorithm, as it in general requires entanglement among exponentially l...

  8. Randomization of inspections

    International Nuclear Information System (INIS)

    Markin, J.T.

    1989-01-01

    As the numbers and complexity of nuclear facilities increase, limitations on resources for international safeguards may restrict attainment of safeguards goals. One option for improving the efficiency of limited resources is to expand the current inspection regime to include random allocation of the amount and frequency of inspection effort to material strata or to facilities. This paper identifies the changes in safeguards policy, administrative procedures, and operational procedures that would be necessary to accommodate randomized inspections and identifies those situations where randomization can improve inspection efficiency and those situations where the current nonrandom inspections should be maintained. 9 refs., 1 tab

  9. Random phenomena; Phenomenes aleatoires

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G. [Commissariat a l' energie atomique et aux energies alternatives - CEA, C.E.N.G., Service d' Electronique, Section d' Electronique, Grenoble (France)

    1963-07-01

    This document gathers a set of conferences presented in 1962. A first one proposes a mathematical introduction to the analysis of random phenomena. The second one presents an axiomatic of probability calculation. The third one proposes an overview of one-dimensional random variables. The fourth one addresses random pairs, and presents basic theorems regarding the algebra of mathematical expectations. The fifth conference discusses some probability laws: binomial distribution, the Poisson distribution, and the Laplace-Gauss distribution. The last one deals with the issues of stochastic convergence and asymptotic distributions.

  10. The exposure data landscape for manufactured chemicals.

    Science.gov (United States)

    Egeghy, Peter P; Judson, Richard; Gangwal, Sumit; Mosher, Shad; Smith, Doris; Vail, James; Cohen Hubal, Elaine A

    2012-01-01

    The U.S. Environmental Protection Agency is developing chemical screening and prioritization programs to evaluate environmental chemicals for potential risk to human health in a rapid and efficient manner. As part of these efforts, it is important to catalog available information on chemical toxicity and exposure from widely dispersed sources. The main objective of this analysis is to define important aspects of the exposure space and to catalog the available exposure information for chemicals being considered for analysis as part of the U.S. EPA ToxCast™ screening and prioritization program. Publicly available exposure data have been extracted into ACToR (Aggregated Computational Toxicology Resource), which combines information for hundreds of thousands of chemicals from >600 public sources. We use data from ACToR to assess the exposure data landscape for environmental chemicals. Of the roughly 100,000 chemicals that have at least limited toxicity information available, less than one-fifth also have exposure information - and for most of these the information is of limited utility (e.g., production volume). Readily accessible data on concentrations in exposure-related media are only available for a much smaller fraction. Among these, the largest number of chemicals is measured in water with over 1150 unique compounds, followed by 788 substances measured in soil, and 670 in air. These small numbers clearly reflect a focus of resources on those substances previously identified as possibly posing a hazard to human health. Exposure to a much broader number of chemicals will need to be measured in order to fully realize the envisioned goal of using exposure information to guide toxicity testing. Published by Elsevier B.V.

  11. Fourth-Order Spatial Correlation of Thermal Light

    International Nuclear Information System (INIS)

    Wen Feng; Zhang Xun; Sun Jia; Song Jian-Ping; Zhang Yan-Peng; Xue Xin-Xin

    2014-01-01

    We investigate the fourth-order spatial correlation properties of pseudo-thermal light in the photon counting regime, and apply the Klyshko advanced-wave picture to describe the process of four-photon coincidence counting measurement. We deduce the theory of a proof-of-principle four-photon coincidence counting configuration, and find that if the four randomly radiated photons come from the same radiation area and are indistinguishable in principle, the fourth-order correlation of them is 24 times larger than that when four photons come from different radiation areas. In addition, we also show that the higher-order spatial correlation function can be decomposed into multiple lower-order correlation functions, and the contrast and visibility of low-order correlation peaks are less than those of higher orders, while the resolutions all are identical. This study may be useful for better understanding the four-photon interference and multi-channel correlation imaging

  12. Warehouse order-picking process. Order-picker routing problem

    Directory of Open Access Journals (Sweden)

    E. V. Korobkov

    2015-01-01

    Full Text Available This article continues “Warehouse order-picking process” cycle and describes order-picker routing sub-problem of a warehouse order-picking process. It draws analogies between the orderpickers’ routing problem and traveling salesman’s problem, shows differences between the standard problem statement of a traveling salesman and routing problem of warehouse orderpickers, and gives the particular Steiner’s problem statement of a traveling salesman.Warehouse layout with a typical order is represented by a graph, with some its vertices corresponding to mandatory order-picker’s visits and some other ones being noncompulsory. The paper describes an optimal Ratliff-Rosenthal algorithm to solve order-picker’s routing problem for the single-block warehouses, i.e. warehouses with only two crossing aisles, defines seven equivalent classes of partial routing sub-graphs and five transitions used to have an optimal routing sub-graph of a order-picker. An extension of optimal Ratliff-Rosenthal order-picker routing algorithm for multi-block warehouses is presented and also reasons for using the routing heuristics instead of exact optimal algorithms are given. The paper offers algorithmic description of the following seven routing heuristics: S-shaped, return, midpoint, largest gap, aisle-by-aisle, composite, and combined as well as modification of combined heuristics. The comparison of orderpicker routing heuristics for one- and two-block warehouses is to be described in the next article of the “Warehouse order-picking process” cycle.

  13. Incremental exposure facilitates adaptation to sensory rearrangement. [vestibular stimulation patterns

    Science.gov (United States)

    Lackner, J. R.; Lobovits, D. N.

    1978-01-01

    Visual-target pointing experiments were performed on 24 adult volunteers in order to compare the relative effectiveness of incremental (stepwise) and single-step exposure conditions on adaptation to visual rearrangement. The differences between the preexposure and postexposure scores served as an index of the adaptation elicited during the exposure period. It is found that both single-step and stepwise exposure to visual rearrangement elicit compensatory changes in sensorimotor coordination. However, stepwise exposure, when compared to single-step exposur in terms of the average magnitude of visual displacement over the exposure period, clearly enhances the rate of adaptation. It seems possible that the enhancement of adaptation to unusual patterns of sensory stimulation produced by incremental exposure reflects a general principle of sensorimotor function.

  14. Smoke exposure at western wildfires.

    Science.gov (United States)

    Timothy E. Reinhardt; Roger D. Ottmar

    2000-01-01

    Smoke exposure measurements among firefighters at wildfires in the Western United States between 1992 and 1995 showed that altogether most exposures were not significant, between 3 and 5 percent of the shift-average exposures exceeded occupational exposure limits for carbon monoxide and respiratory irritants. Exposure to benzene and total suspended particulate was not...

  15. Major depression and secondhand smoke exposure.

    Science.gov (United States)

    Patten, Scott B; Williams, Jeanne V A; Lavorato, Dina H; Woolf, Benjamin; Wang, Jian Li; Bulloch, Andrew G M; Sajobi, Tolulope

    2018-01-01

    Epidemiological studies have consistently linked smoking to poor mental health. Among non-smokers, some studies have also reported associations between secondhand smoke exposure and psychological symptoms. However, an association between secondhand smoke exposure and depressive disorders has not been well established. This analysis used cross-sectional data from a series of 10 population surveys conducted in Canada between 2003 and 2013. The surveys targeted the Canadian household population, included a brief structured interview for past year major depressive episode (MDE) and included items assessing secondhand smoke exposure. We used two-stage individual-level random-effects meta-regression to synthesize results from these surveys. Over the study interval, about 20% of non-smokers reported substantial exposure to secondhand smoke. In this group, the pooled annual prevalence of MDE was 6.1% (95% CI 5.3-6.9) compared to 4.0% (95% CI 3.7-4.3) in non-smokers without secondhand smoke exposure. The crude odds ratio was 1.5 (95% CI 1.4-1.7). With adjustment for a set of potential confounding variables the odds ratio was unchanged, 1.4 (95% CI 1.2 - 1.6). These results provide additional support for public health measures aimed at reducing secondhand smoke exposure. A causal connection between secondhand smoke exposure and MDEs cannot be confirmed due to the cross-sectional nature of the data. Longitudinal studies are needed to establish temporal sequencing. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Generation of high order modes

    CSIR Research Space (South Africa)

    Ngcobo, S

    2012-07-01

    Full Text Available with the location of the Laguerre polynomial zeros. The Diffractive optical element is used to shape the TEM00 Gassian beam and force the laser to operate on a higher order TEMp0 Laguerre-Gaussian modes or high order superposition of Laguerre-Gaussian modes...

  17. Orderings for conjugate gradient preconditionings

    Science.gov (United States)

    Ortega, James M.

    1991-01-01

    The effect of orderings on the rate of convergence of the conjugate gradient method with SSOR or incomplete Cholesky preconditioning is examined. Some results also are presented that help to explain why red/black ordering gives an inferior rate of convergence.

  18. Order and disorder in matter

    CERN Document Server

    Careri, Giorgio

    1984-01-01

    Order and Disorder in Matter offers a comprehensive and up-to-date view of structures and processes in matter, in terms of the evolving concepts of order and disorder. Particular emphasis is given to the recent evolution of these concepts and their relationship to the more complex systems in nature.

  19. Tunable random packings

    International Nuclear Information System (INIS)

    Lumay, G; Vandewalle, N

    2007-01-01

    We present an experimental protocol that allows one to tune the packing fraction η of a random pile of ferromagnetic spheres from a value close to the lower limit of random loose packing η RLP ≅0.56 to the upper limit of random close packing η RCP ≅0.64. This broad range of packing fraction values is obtained under normal gravity in air, by adjusting a magnetic cohesion between the grains during the formation of the pile. Attractive and repulsive magnetic interactions are found to affect stongly the internal structure and the stability of sphere packing. After the formation of the pile, the induced cohesion is decreased continuously along a linear decreasing ramp. The controlled collapse of the pile is found to generate various and reproducible values of the random packing fraction η

  20. Random maintenance policies

    CERN Document Server

    Nakagawa, Toshio

    2014-01-01

    Exploring random maintenance models, this book provides an introduction to the implementation of random maintenance, and it is one of the first books to be written on this subject.  It aims to help readers learn new techniques for applying random policies to actual reliability models, and it provides new theoretical analyses of various models including classical replacement, preventive maintenance and inspection policies. These policies are applied to scheduling problems, backup policies of database systems, maintenance policies of cumulative damage models, and reliability of random redundant systems. Reliability theory is a major concern for engineers and managers, and in light of Japan’s recent earthquake, the reliability of large-scale systems has increased in importance. This also highlights the need for a new notion of maintenance and reliability theory, and how this can practically be applied to systems. Providing an essential guide for engineers and managers specializing in reliability maintenance a...

  1. Theory of random sets

    CERN Document Server

    Molchanov, Ilya

    2017-01-01

    This monograph, now in a thoroughly revised second edition, offers the latest research on random sets. It has been extended to include substantial developments achieved since 2005, some of them motivated by applications of random sets to econometrics and finance. The present volume builds on the foundations laid by Matheron and others, including the vast advances in stochastic geometry, probability theory, set-valued analysis, and statistical inference. It shows the various interdisciplinary relationships of random set theory within other parts of mathematics, and at the same time fixes terminology and notation that often vary in the literature, establishing it as a natural part of modern probability theory and providing a platform for future development. It is completely self-contained, systematic and exhaustive, with the full proofs that are necessary to gain insight. Aimed at research level, Theory of Random Sets will be an invaluable reference for probabilists; mathematicians working in convex and integ...

  2. A review of instrumental variable estimators for Mendelian randomization.

    Science.gov (United States)

    Burgess, Stephen; Small, Dylan S; Thompson, Simon G

    2017-10-01

    Instrumental variable analysis is an approach for obtaining causal inferences on the effect of an exposure (risk factor) on an outcome from observational data. It has gained in popularity over the past decade with the use of genetic variants as instrumental variables, known as Mendelian randomization. An instrumental variable is associated with the exposure, but not associated with any confounder of the exposure-outcome association, nor is there any causal pathway from the instrumental variable to the outcome other than via the exposure. Under the assumption that a single instrumental variable or a set of instrumental variables for the exposure is available, the causal effect of the exposure on the outcome can be estimated. There are several methods available for instrumental variable estimation; we consider the ratio method, two-stage methods, likelihood-based methods, and semi-parametric methods. Techniques for obtaining statistical inferences and confidence intervals are presented. The statistical properties of estimates from these methods are compared, and practical advice is given about choosing a suitable analysis method. In particular, bias and coverage properties of estimators are considered, especially with weak instruments. Settings particularly relevant to Mendelian randomization are prioritized in the paper, notably the scenario of a continuous exposure and a continuous or binary outcome.

  3. Operon Gene Order Is Optimized for Ordered Protein Complex Assembly

    Science.gov (United States)

    Wells, Jonathan N.; Bergendahl, L. Therese; Marsh, Joseph A.

    2016-01-01

    Summary The assembly of heteromeric protein complexes is an inherently stochastic process in which multiple genes are expressed separately into proteins, which must then somehow find each other within the cell. Here, we considered one of the ways by which prokaryotic organisms have attempted to maximize the efficiency of protein complex assembly: the organization of subunit-encoding genes into operons. Using structure-based assembly predictions, we show that operon gene order has been optimized to match the order in which protein subunits assemble. Exceptions to this are almost entirely highly expressed proteins for which assembly is less stochastic and for which precisely ordered translation offers less benefit. Overall, these results show that ordered protein complex assembly pathways are of significant biological importance and represent a major evolutionary constraint on operon gene organization. PMID:26804901

  4. 2D gravity, random surfaces and all that

    International Nuclear Information System (INIS)

    Ambjoern, J.

    1990-11-01

    I review the recent progress in 2d gravity and discuss the new numerical simulations for 2d gravity and for random surfaces in d>2. The random surface theories of interest in d>2 have extrinsic curvature terms, and for a finite value of the extrinsic curvature coupling there seems to be a second order phase transition where the string tension scales. (orig.)

  5. The potts chain in a random field: an exact solution

    International Nuclear Information System (INIS)

    Riera, R.; Chaves, C.M.G.F.; Santos, Raimundo R. dos.

    1984-01-01

    An exact solution is presented for the one-dimensional q-state Potts model in a quenched random field. The ferromagnetic phase is unstable against any small random field perturbation. The correlation function and the Edwards-Anderson order parameter Q are discussed. For finite q only the phase with Q ≠ 0 is present. (Author) [pt

  6. A simple consensus algorithm for distributed averaging in random ...

    Indian Academy of Sciences (India)

    Random geographical networks are realistic models for wireless sensor ... work are cheap, unreliable, with limited computational power and limited .... signal xj from node j, j does not need to transmit its degree to i in order to let i compute.

  7. Quantum Random Networks for Type 2 Quantum Computers

    National Research Council Canada - National Science Library

    Allara, David L; Hasslacher, Brosl

    2006-01-01

    Random boolean networks (RBNs) have been studied theoretically and computationally in order to be able to use their remarkable self-healing and large basins of altercation properties as quantum computing architectures, especially...

  8. Waltzing between Order and Ordering - a Social Practice Perspective

    DEFF Research Database (Denmark)

    Sørensen, Brian Vejrum; Boer, Harry

    2007-01-01

    Organisations are often depicted as strategic intention seeking entities creating strategic objects that form pockets of order in uncertain environments. This design-based view of strategic development is challenged in this paper. The paper illustrates that organisations in building dynamic capab...... change. We find that potentially stabilising objects are underutilised as part of the ongoing ordering process, because they are generally treated as fixed objects rather than as common ground for negotiation and thus dynamic capabilities. ...

  9. Counterbalancing for serial order carryover effects in experimental condition orders

    OpenAIRE

    Brooks, Joseph L

    2012-01-01

    Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed for generating counterbalanced sequences for repeated-measures designs including those with multiple observations of each condition on one participant...

  10. Sampling problems for randomly broken sticks

    Energy Technology Data Exchange (ETDEWEB)

    Huillet, Thierry [Laboratoire de Physique Theorique et Modelisation, CNRS-UMR 8089 et Universite de Cergy-Pontoise, 5 mail Gay-Lussac, 95031, Neuville sur Oise (France)

    2003-04-11

    Consider the random partitioning model of a population (represented by a stick of length 1) into n species (fragments) with identically distributed random weights (sizes). Upon ranking the fragments' weights according to ascending sizes, let S{sub m:n} be the size of the mth smallest fragment. Assume that some observer is sampling such populations as follows: drop at random k points (the sample size) onto this stick and record the corresponding numbers of visited fragments. We shall investigate the following sampling problems: (1) what is the sample size if the sampling is carried out until the first visit of the smallest fragment (size S{sub 1:n})? (2) For a given sample size, have all the fragments of the stick been visited at least once or not? This question is related to Feller's random coupon collector problem. (3) In what order are new fragments being discovered and what is the random number of samples separating the discovery of consecutive new fragments until exhaustion of the list? For this problem, the distribution of the size-biased permutation of the species' weights, as the sequence of their weights in their order of appearance is needed and studied.

  11. Quantum randomness and unpredictability

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, Gregg [Quantum Communication and Measurement Laboratory, Department of Electrical and Computer Engineering and Division of Natural Science and Mathematics, Boston University, Boston, MA (United States)

    2017-06-15

    Quantum mechanics is a physical theory supplying probabilities corresponding to expectation values for measurement outcomes. Indeed, its formalism can be constructed with measurement as a fundamental process, as was done by Schwinger, provided that individual measurements outcomes occur in a random way. The randomness appearing in quantum mechanics, as with other forms of randomness, has often been considered equivalent to a form of indeterminism. Here, it is argued that quantum randomness should instead be understood as a form of unpredictability because, amongst other things, indeterminism is not a necessary condition for randomness. For concreteness, an explication of the randomness of quantum mechanics as the unpredictability of quantum measurement outcomes is provided. Finally, it is shown how this view can be combined with the recently introduced view that the very appearance of individual quantum measurement outcomes can be grounded in the Plenitude principle of Leibniz, a principle variants of which have been utilized in physics by Dirac and Gell-Mann in relation to the fundamental processes. This move provides further support to Schwinger's ''symbolic'' derivation of quantum mechanics from measurement. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Fast physical random bit generation with chaotic semiconductor lasers

    Science.gov (United States)

    Uchida, Atsushi; Amano, Kazuya; Inoue, Masaki; Hirano, Kunihito; Naito, Sunao; Someya, Hiroyuki; Oowada, Isao; Kurashige, Takayuki; Shiki, Masaru; Yoshimori, Shigeru; Yoshimura, Kazuyuki; Davis, Peter

    2008-12-01

    Random number generators in digital information systems make use of physical entropy sources such as electronic and photonic noise to add unpredictability to deterministically generated pseudo-random sequences. However, there is a large gap between the generation rates achieved with existing physical sources and the high data rates of many computation and communication systems; this is a fundamental weakness of these systems. Here we show that good quality random bit sequences can be generated at very fast bit rates using physical chaos in semiconductor lasers. Streams of bits that pass standard statistical tests for randomness have been generated at rates of up to 1.7 Gbps by sampling the fluctuating optical output of two chaotic lasers. This rate is an order of magnitude faster than that of previously reported devices for physical random bit generators with verified randomness. This means that the performance of random number generators can be greatly improved by using chaotic laser devices as physical entropy sources.

  13. Metaheuristic approaches to order sequencing on a unidirectional picking line

    Directory of Open Access Journals (Sweden)

    AP de Villiers

    2013-06-01

    Full Text Available In this paper the sequencing of orders on a unidirectional picking line is considered. The aim of the order sequencing is to minimise the number of cycles travelled by a picker within the picking line to complete all orders. A tabu search, simulated annealing, genetic algorithm, generalised extremal optimisation and a random local search are presented as possible solution approaches. Computational results based on real life data instances are presented for these metaheuristics and compared to the performance of a lower bound and the solutions used in practise. The random local search exhibits the best overall solution quality, however, the generalised extremal optimisation approach delivers comparable results in considerably shorter computational times.

  14. The Ising model coupled to 2d orders

    Science.gov (United States)

    Glaser, Lisa

    2018-04-01

    In this article we make first steps in coupling matter to causal set theory in the path integral. We explore the case of the Ising model coupled to the 2d discrete Einstein Hilbert action, restricted to the 2d orders. We probe the phase diagram in terms of the Wick rotation parameter β and the Ising coupling j and find that the matter and the causal sets together give rise to an interesting phase structure. The couplings give rise to five different phases. The causal sets take on random or crystalline characteristics as described in Surya (2012 Class. Quantum Grav. 29 132001) and the Ising model can be correlated or uncorrelated on the random orders and correlated, uncorrelated or anti-correlated on the crystalline orders. We find that at least one new phase transition arises, in which the Ising spins push the causal set into the crystalline phase.

  15. Hazards of radiation exposure

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1982-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risks to health from exposure to low levels of radiation. There is scant data on somatic and genetic risks at environmental and occupational levels of radiation exposure. The available data on radiation induced carcinogenesis and mutagenesis are for high doses and high dose rates of radiation. Risk assessments for low level radiation are obtained using these data, assuming a linear dose-response relationship. During uranium mining the chief source of radiation hazard is inhalation of radon daughters. The correlation between radon daughter exposure and the increased incidence of lung cancer has been well documented. For radiation exposures at and below occupational limits, the associated risk of radiation induced cancers and genetic abnormalities is small and should not lead to a detectable increase over naturally occurring rates

  16. Personal Chemical Exposure informatics

    Science.gov (United States)

    Chemical Exposure science is the study of human contact with chemicals (from manufacturing facilities, everyday products, waste) occurring in their environments and advances knowledge of the mechanisms and dynamics of events that cause or prevent adverse health outcomes. (adapted...

  17. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2002-01-01

    Behavioral, neurochemical, and immunocytochemical studies characterized the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and permethrin (PM...

  18. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2001-01-01

    Behavioral, neurochemical, and immunocytochemical studies characterized the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and permethrin (PM...

  19. Insecticide Exposure in Parkinsonism

    National Research Council Canada - National Science Library

    Bloomquist, Jeffrey

    2003-01-01

    Behavioral, neurochemical, and immunocytochemical studies are characterizing the possible role of insecticide exposure in the etiology of Parkinson's disease as it may relate to Gulf War Syndrome. Chlorpyrifos (CP) and/or permethrin (PM...

  20. Minimizing Exposure at Work

    Science.gov (United States)

    ; Environment Human Health Animal Health Safe Use Practices Food Safety Environment Air Water Soil Wildlife Home Page Pesticide Health and Safety Information Safe Use Practices Minimizing Exposure at Work Pesticides - Pennsylvania State University Cooperative Extension Personal Protective Equipment for Working