WorldWideScience

Sample records for random media liliana

  1. 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

  2. Quechua and Spanish, Evidentiality and Aspect: Commentary on Liliana Sanchez

    Science.gov (United States)

    Muysken, Pieter

    2004-01-01

    Liliana Sanchez' paper is a welcome contribution to the growing body of literature on Andean Spanish (cf. a recent survey in Muysken, 2004a), welcome both because a well-motivated and clearly described methodology is used and because it is embedded in an explicit theoretical framework. I do not have reservations about the overall conclusions of…

  3. Electromagnetic scattering from random media

    CERN Document Server

    Field, Timothy R

    2009-01-01

    - ;The book develops the dynamical theory of scattering from random media from first principles. Its key findings are to characterize the time evolution of the scattered field in terms of stochastic differential equations, and to illustrate this framework

  4. Wave propagation and scattering in random media

    CERN Document Server

    Ishimaru, Akira

    1978-01-01

    Wave Propagation and Scattering in Random Media, Volume 2, presents the fundamental formulations of wave propagation and scattering in random media in a unified and systematic manner. The topics covered in this book may be grouped into three categories: waves in random scatterers, waves in random continua, and rough surface scattering. Random scatterers are random distributions of many particles. Examples are rain, fog, smog, hail, ocean particles, red blood cells, polymers, and other particles in a state of Brownian motion. Random continua are the media whose characteristics vary randomly an

  5. Dielectric polarization in random media

    International Nuclear Information System (INIS)

    Ramshaw, J.D.

    1984-01-01

    The theory of dielectric polarization in random media is systematically formulated in terms of response kernels. The primary response kernel K(12) governs the mean dielectric response at the point r 1 to the external electric field at the point r 2 in an infinite system. The inverse of K(12) is denoted by L(12);. it is simpler and more fundamental than K(12) itself. Rigorous expressions are obtained for the effective dielectric constant epsilon( in terms of L(12) and K(12). The latter expression involves the Onsger-Kirkwood function (epsilon(-epsilon 0 (2epsilon(+epsilon 0 )/epsilon 0 epsilon( (where epsilon 0 is an arbitrary reference value), and appears to be new to the random medium context. A wide variety of series representations for epsilon( are generated by means of general perturbation expansions for K(12) and L(12). A discussion is given of certain pitfalls in the theory, most of which are related to the fact that the response kernels are long ranged. It is shown how the dielectric behavior of nonpolar molecular fluids may be treated as a special case of the general theory. The present results for epsilon( apply equally well to other effective phenomenological coefficients of the same generic type, such as thermal and electrical conductivity, magnetic susceptibility, and diffusion coefficients

  6. Nonstationary interference and scattering from random media

    International Nuclear Information System (INIS)

    Nazikian, R.

    1991-12-01

    For the small angle scattering of coherent plane waves from inhomogeneous random media, the three dimensional mean square distribution of random fluctuations may be recovered from the interferometric detection of the nonstationary modulational structure of the scattered field. Modulational properties of coherent waves scattered from random media are related to nonlocal correlations in the double sideband structure of the Fourier transform of the scattering potential. Such correlations may be expressed in terms of a suitability generalized spectral coherence function for analytic fields

  7. Entanglement dynamics in random media

    Science.gov (United States)

    Menezes, G.; Svaiter, N. F.; Zarro, C. A. D.

    2017-12-01

    We study how the entanglement dynamics between two-level atoms is impacted by random fluctuations of the light cone. In our model the two-atom system is envisaged as an open system coupled with an electromagnetic field in the vacuum state. We employ the quantum master equation in the Born-Markov approximation in order to describe the completely positive time evolution of the atomic system. We restrict our investigations to the situation in which the atoms are coupled individually to two spatially separated cavities, one of which displays the emergence of light-cone fluctuations. In such a disordered cavity, we assume that the coefficients of the Klein-Gordon equation are random functions of the spatial coordinates. The disordered medium is modeled by a centered, stationary, and Gaussian process. We demonstrate that disorder has the effect of slowing down the entanglement decay. We conjecture that in a strong-disorder environment the mean life of entangled states can be enhanced in such a way as to almost completely suppress quantum nonlocal decoherence.

  8. Quantum optics in multiple scattering random media

    DEFF Research Database (Denmark)

    Lodahl, Peter; Lagendijk, Ad

    2005-01-01

    Quantum Optics in Multiple Scattering Random Media Peter Lodahl Research Center COM, Technical University of Denmark, Dk-2800 Lyngby, Denmark. Coherent transport of light in a disordered random medium has attracted enormous attention both from a fundamental and application point of view. Coherent......-tions that should be readily attainable experimentally is devised. Figure 1. Inverse total transmission of shot noise (left) and technical noise (right) as a function of the thickness of the ran-dom medium. The experimental data are well explained by theory (curves). [1] J. Tworzydlo and C.W.J. Beenakker, Phys. Rev...

  9. 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

  10. A randomized trial of social media from Circulation.

    Science.gov (United States)

    Fox, Caroline S; Bonaca, Marc A; Ryan, John J; Massaro, Joseph M; Barry, Karen; Loscalzo, Joseph

    2015-01-06

    Medical journals use social media to distribute the findings of published articles. Whether social media exposure to original articles improves article impact metrics is uncertain. Articles were randomized to receive targeted social media exposure from Circulation, including postings on the journal's Facebook and Twitter feeds. The primary end point was 30-day article page views. We conducted an intention-to-treat analysis comparing article page views by the Wilcoxon Rank sum test between articles randomized to social media as compared with those in the control group, which received no social media from Circulation. Prespecified subgroups included article type (population/clinical/basic), US versus non-US corresponding author, and whether the article received an editorial. Overall, 243 articles were randomized: 121 in the social media arm and 122 in the control arm. There was no difference in median 30-day page views (409 [social media] versus 392 [control], P=0.80). No differences were observed by article type (clinical, population, or basic science; P=0.19), whether an article had an editorial (P=0.87), or whether the corresponding author was from the United States (P=0.73). A social media strategy for a cardiovascular journal did not increase the number of times an article was viewed. Further research is necessary to understand and quantify the ways in which social media can increase the impact of published cardiovascular research. © 2014 American Heart Association, Inc.

  11. Remote sensing and communications in random media

    Science.gov (United States)

    Papanicolaou, George

    2003-04-01

    Reliable, high-capacity communications in scattering media can be effectively established with some basic remote sensing techniques involving time reversal. I will formulate these problems and discuss the various mathematical approaches that can be used for analysis. It turns out that stochastic analysis plays an important role and, in some cases, gives very satisfactory results. One such result is the spectacular increase in communications capacity in a richly scattering environment. I will end with a discussion of applications and computational issues that arise in the realistic simulation of communication systems.

  12. Electromagnetic Wave Propagation in Random Media

    DEFF Research Database (Denmark)

    Pécseli, Hans

    1984-01-01

    The propagation of a narrow frequency band beam of electromagnetic waves in a medium with randomly varying index of refraction is considered. A novel formulation of the governing equation is proposed. An equation for the average Green function (or transition probability) can then be derived...

  13. Synthesis of results of randomized controlled trials of contrast media

    International Nuclear Information System (INIS)

    Kinnison, M.L.; Powe, N.R.; Steinberg, E.P.

    1988-01-01

    The authors review 100 randomized controlled trials (RCTs) that examine the safety or efficacy of new low-osmolality contrast media (LOM) and focus on the 43 RCTs judged to be of the highest quality. These RCTs showed no consistent differences in nephrotoxicity between high- and low-osmolality contrast media. Certain cardiovascular parameters were altered less with low-osmolality agents during intracardiac injection, but the clinical significance of these differences in unclear. Heat and pain sensations occurred less often with low-osmolality contrast media. No differences were noted in the incidence of nausea, vomiting, urticaria, or bronchospasm. Even with numerous RCTs comparing these media, physicians still must make economically significant choices about contrast media without sufficient data about their relative safety

  14. Nonlinear evolution equations for waves in random media

    International Nuclear Information System (INIS)

    Pelinovsky, E.; Talipova, T.

    1994-01-01

    The scope of this paper is to highlight the main ideas of asymptotical methods applying in modern approaches of description of nonlinear wave propagation in random media. We start with the discussion of the classical conception of ''mean field''. Then an exactly solvable model describing nonlinear wave propagation in the medium with fluctuating parameters is considered in order to demonstrate that the ''mean field'' method is not correct. We develop new asymptotic procedures of obtaining the nonlinear evolution equations for the wave fields in random media. (author). 16 refs

  15. Depinning of interacting particles in random media

    Science.gov (United States)

    Zapperi, Stefano; Andrade, José S., Jr.; Mendes Filho, Josué

    2000-06-01

    We study the overdamped motion of interacting particles in a random medium using the model introduced by Pla and Nori [Phys. Rev. Lett. 67, 919 (1991)]. We investigate the associated depinning transition by numerical integration of the equation of motion and show evidence that the model is in the same universality class of a driven elastic chain on a rough substrate. We discuss the implications of these results for flux line motion in type-II superconductors.

  16. Exactly averaged equations for flow and transport in random media

    International Nuclear Information System (INIS)

    Shvidler, Mark; Karasaki, Kenzi

    2001-01-01

    It is well known that exact averaging of the equations of flow and transport in random porous media can be realized only for a small number of special, occasionally exotic, fields. On the other hand, the properties of approximate averaging methods are not yet fully understood. For example, the convergence behavior and the accuracy of truncated perturbation series. Furthermore, the calculation of the high-order perturbations is very complicated. These problems for a long time have stimulated attempts to find the answer for the question: Are there in existence some exact general and sufficiently universal forms of averaged equations? If the answer is positive, there arises the problem of the construction of these equations and analyzing them. There exist many publications related to these problems and oriented on different applications: hydrodynamics, flow and transport in porous media, theory of elasticity, acoustic and electromagnetic waves in random fields, etc. We present a method of finding the general form of exactly averaged equations for flow and transport in random fields by using (1) an assumption of the existence of Green's functions for appropriate stochastic problems, (2) some general properties of the Green's functions, and (3) the some basic information about the random fields of the conductivity, porosity and flow velocity. We present a general form of the exactly averaged non-local equations for the following cases. 1. Steady-state flow with sources in porous media with random conductivity. 2. Transient flow with sources in compressible media with random conductivity and porosity. 3. Non-reactive solute transport in random porous media. We discuss the problem of uniqueness and the properties of the non-local averaged equations, for the cases with some types of symmetry (isotropic, transversal isotropic, orthotropic) and we analyze the hypothesis of the structure non-local equations in general case of stochastically homogeneous fields. (author)

  17. Mathematical Problems in Imaging in Random Media

    Science.gov (United States)

    2015-01-15

    Wigner transforms and ambiguity functions . The phase space approach works for a single target or for groups of targets that are in similar motion (either...x′ ρ(~x′)bj(ω, z, ~x ′)eiβj(ω)z ′ , (4) in terms of the amplitudes aj and bj of the modal expansion of the Green’s function G(t, ~x, ~x ′). We...are normalized trigonometric functions . The random fluctuations cause net scattering effects at ranges z = ε−2Z, with Z & λo. There we have( a(ω, z

  18. Laser beam propagation through random media

    CERN Document Server

    Andrews, Larry C

    2005-01-01

    Since publication of the first edition of this text in 1998, there have been several new, important developments in the theory of beam wave propagation through a random medium, which have been incorporated into this second edition. Also new to this edition are models for the scintillation index under moderate-to-strong irradiance fluctuations; models for aperture averaging based on ABCD ray matrices; beam wander and its effects on scintillation; theory of partial coherence of the source; models of rough targets for ladar applications; phase fluctuations; analysis of other beam shapes; plus exp

  19. Distribution functions for fluids in random media

    International Nuclear Information System (INIS)

    Madden, W.G.; Glandt, E.D.

    1988-01-01

    A random medium is considered, composed of identifiable interactive sites or obstacles equilibrated at a high temperature and then quenched rapidly to form a rigid structure, statistically homogeneous on all but molecular length scales. The equilibrium statistical mechanics of a fluid contained inside this quenched medium is discussed. Various particle-particle and particle-obstacle correlation functions, which differ form the corresponding functions for a fully equilibrated binary mixture, are defined through an averaging process over the static ensemble of obstacle configurations and applications of topological reduction techniques. The Ornstein-Zernike equations also differ from their equilibrium counterparts

  20. Long time tails in stationary random media II: Applications

    NARCIS (Netherlands)

    Machta, J.; Ernst, M.H.; Dorfman, J.R.; Beijeren, H. van

    1984-01-01

    In a previous paper we developed a mode-coupling theory to describe the long time properties of diffusion in stationary, statistically homogeneous, random media. Here the general theory is applied to deterministic and stochastic Lorentz models and several hopping models. The mode-coupling theory

  1. Phase behavior of random copolymers in quenched random media

    International Nuclear Information System (INIS)

    Chakraborty, A.K.; Shakhnovich, E.I.

    1995-01-01

    In this paper, we consider the behavior of random heteropolymers in a quenched disordered medium. We develop a field theory and obtain a mean-field solution that allows for replica symmetry breaking. The presence of an external disorder leads to the formation of compact states; a homopolymeric effect. We compute the phase diagram for two classes of problems. First, we consider the situation wherein the bare heteropolymer prefers like segments to segregate, and second, we examine cases where the bare heteropolymer prefers unlike segments to mix. For the first class of systems, we find a phase diagram characterized by a replica symmetry broken phase that exists below a particular temperature. This temperature grows with the strength of the external disorder. In the second class of situations, the phase diagram is much richer. Here we find two replica symmetry broken phases with different patterns separated by a reentrant phase. The reentrant phase and one of the two replica symmetry broken phases are induced by interactions with the external disorder. The dependence of the location of the phase boundaries on the strength of the external disorder are elucidated. We discuss our results from a physical standpoint, and note the testable experimental consequences of our findings. copyright 1995 American Institute of Physics

  2. Polarization phenomena on coherent particle backscattering by random media

    International Nuclear Information System (INIS)

    Gorodnichev, E.E.; Dudarev, S.L.; Rogozkin, D.B.

    1990-01-01

    An exact solution is found for the problem of coherent enhanced backscattering of spin 1/2 particles by random media with small-radius scatterers. The polarization features in the angular spectrum are analyzed for particles reflected by three- and two-dimensional disordered systems and by medium with Anderson disorder (periodic system of random scatterers). The analysis is carried out in the case of magnetic and spin-orbit interaction with the scattering centers. The effects predicted have not any analogues on coherent backscattering of light and scalar waves

  3. Percolation, statistical topography, and transport in random media

    International Nuclear Information System (INIS)

    Isichenko, M.B.

    1992-01-01

    A review of classical percolation theory is presented, with an emphasis on novel applications to statistical topography, turbulent diffusion, and heterogeneous media. Statistical topography involves the geometrical properties of the isosets (contour lines or surfaces) of a random potential ψ(x). For rapidly decaying correlations of ψ, the isopotentials fall into the same universality class as the perimeters of percolation clusters. The topography of long-range correlated potentials involves many length scales and is associated either with the correlated percolation problem or with Mandelbrot's fractional Brownian reliefs. In all cases, the concept of fractal dimension is particularly fruitful in characterizing the geometry of random fields. The physical applications of statistical topography include diffusion in random velocity fields, heat and particle transport in turbulent plasmas, quantum Hall effect, magnetoresistance in inhomogeneous conductors with the classical Hall effect, and many others where random isopotentials are relevant. A geometrical approach to studying transport in random media, which captures essential qualitative features of the described phenomena, is advocated

  4. Radiation Transport in Random Media With Large Fluctuations

    Science.gov (United States)

    Olson, Aaron; Prinja, Anil; Franke, Brian

    2017-09-01

    Neutral particle transport in media exhibiting large and complex material property spatial variation is modeled by representing cross sections as lognormal random functions of space and generated through a nonlinear memory-less transformation of a Gaussian process with covariance uniquely determined by the covariance of the cross section. A Karhunen-Loève decomposition of the Gaussian process is implemented to effciently generate realizations of the random cross sections and Woodcock Monte Carlo used to transport particles on each realization and generate benchmark solutions for the mean and variance of the particle flux as well as probability densities of the particle reflectance and transmittance. A computationally effcient stochastic collocation method is implemented to directly compute the statistical moments such as the mean and variance, while a polynomial chaos expansion in conjunction with stochastic collocation provides a convenient surrogate model that also produces probability densities of output quantities of interest. Extensive numerical testing demonstrates that use of stochastic reduced-order modeling provides an accurate and cost-effective alternative to random sampling for particle transport in random media.

  5. Directed self-avoiding walks in random media

    International Nuclear Information System (INIS)

    Santra, S. B.; Seitz, W. A.; Klein, D. J.

    2001-01-01

    Two types of directed self-avoiding walks (SAW's), namely, three-choice directed SAW and outwardly directed SAW, have been studied on infinite percolation clusters on the square lattice in two dimensions. The walks on the percolation clusters are generated via a Monte Carlo technique. The longitudinal extension R N and the transverse fluctuation W N have been measured as a function of the number of steps N. Slight swelling is observed in the longitudinal direction on the random lattices. A crossover from shrinking to swelling of the transverse fluctuations is found at a certain length N c of the walks. The exponents related to the transverse fluctuations are seen to be unchanged in the random media even as the percolation threshold is reached. The scaling function form of the extensions are verified

  6. Of Maps and Monsters: A Discussion of Being (Non)Human, or on the Topography of “Monsters” Medieval and Modern by Liliana Sikorska

    OpenAIRE

    Mirosława Buchholtz

    2017-01-01

    The concept of humanity has taken on new meanings in the era of posthumanist debate. Engaging both prehumanist and posthumanist perspectives, Liliana Sikorska strips away layers of cognitive mappings performed over hundreds of years in Western culture to expose in her recent essay the mechanisms that have exacerbated the East–West divide. While the majority of discussed texts come from medieval and Victorian literature and culture, it becomes obvious to the reader of her book that the issues ...

  7. Generalized Optical Theorem Detection in Random and Complex Media

    Science.gov (United States)

    Tu, Jing

    The problem of detecting changes of a medium or environment based on active, transmit-plus-receive wave sensor data is at the heart of many important applications including radar, surveillance, remote sensing, nondestructive testing, and cancer detection. This is a challenging problem because both the change or target and the surrounding background medium are in general unknown and can be quite complex. This Ph.D. dissertation presents a new wave physics-based approach for the detection of targets or changes in rather arbitrary backgrounds. The proposed methodology is rooted on a fundamental result of wave theory called the optical theorem, which gives real physical energy meaning to the statistics used for detection. This dissertation is composed of two main parts. The first part significantly expands the theory and understanding of the optical theorem for arbitrary probing fields and arbitrary media including nonreciprocal media, active media, as well as time-varying and nonlinear scatterers. The proposed formalism addresses both scalar and full vector electromagnetic fields. The second contribution of this dissertation is the application of the optical theorem to change detection with particular emphasis on random, complex, and active media, including single frequency probing fields and broadband probing fields. The first part of this work focuses on the generalization of the existing theoretical repertoire and interpretation of the scalar and electromagnetic optical theorem. Several fundamental generalizations of the optical theorem are developed. A new theory is developed for the optical theorem for scalar fields in nonhomogeneous media which can be bounded or unbounded. The bounded media context is essential for applications such as intrusion detection and surveillance in enclosed environments such as indoor facilities, caves, tunnels, as well as for nondestructive testing and communication systems based on wave-guiding structures. The developed scalar

  8. Geometric Models for Isotropic Random Porous Media: A Review

    Directory of Open Access Journals (Sweden)

    Helmut Hermann

    2014-01-01

    Full Text Available Models for random porous media are considered. The models are isotropic both from the local and the macroscopic point of view; that is, the pores have spherical shape or their surface shows piecewise spherical curvature, and there is no macroscopic gradient of any geometrical feature. Both closed-pore and open-pore systems are discussed. The Poisson grain model, the model of hard spheres packing, and the penetrable sphere model are used; variable size distribution of the pores is included. A parameter is introduced which controls the degree of open-porosity. Besides systems built up by a single solid phase, models for porous media with the internal surface coated by a second phase are treated. Volume fraction, surface area, and correlation functions are given explicitly where applicable; otherwise numerical methods for determination are described. Effective medium theory is applied to calculate physical properties for the models such as isotropic elastic moduli, thermal and electrical conductivity, and static dielectric constant. The methods presented are exemplified by applications: small-angle scattering of systems showing fractal-like behavior in limited ranges of linear dimension, optimization of nanoporous insulating materials, and improvement of properties of open-pore systems by atomic layer deposition of a second phase on the internal surface.

  9. Branched flow and caustics in random media with magnetic fields

    Science.gov (United States)

    Metzger, Jakob; Fleischmann, Ragnar; Geisel, Theo

    2009-03-01

    Classical particles as well as quantum mechanical waves exhibit complex behaviour when propagating through random media. One of the dominant features of the dynamics in correlated, weak disorder potentials is the branching of the flow. This can be observed in several physical systems, most notably in the electron flow in two-dimensional electron gases [1], and has also been used to describe the formation of freak waves [2]. We present advances in the theoretical understanding and numerical simulation of classical branched flows in magnetic fields. In particular, we study branching statistics and branch density profiles. Our results have direct consequences for experiments which measure transport properties in electronic systems [3].[1] e.g. M. A. Topinka et al., Nature 410, 183 (2001), M. P. Jura et al., Nature Physics 3, 841 (2007)[2] E. J. Heller, L. Kaplan and A. Dahlen, J. Geophys. Res., 113, C09023 (2008)[3] J. J. Metzger, R. Fleischmann and T. Geisel, in preparation

  10. Percolation for a model of statistically inhomogeneous random media

    International Nuclear Information System (INIS)

    Quintanilla, J.; Torquato, S.

    1999-01-01

    We study clustering and percolation phenomena for a model of statistically inhomogeneous two-phase random media, including functionally graded materials. This model consists of inhomogeneous fully penetrable (Poisson distributed) disks and can be constructed for any specified variation of volume fraction. We quantify the transition zone in the model, defined by the frontier of the cluster of disks which are connected to the disk-covered portion of the model, by defining the coastline function and correlation functions for the coastline. We find that the behavior of these functions becomes largely independent of the specific choice of grade in volume fraction as the separation of length scales becomes large. We also show that the correlation function behaves in a manner similar to that of fractal Brownian motion. Finally, we study fractal characteristics of the frontier itself and compare to similar properties for two-dimensional percolation on a lattice. In particular, we show that the average location of the frontier appears to be related to the percolation threshold for homogeneous fully penetrable disks. copyright 1999 American Institute of Physics

  11. Of Maps and Monsters: A Discussion of Being (NonHuman, or on the Topography of “Monsters” Medieval and Modern by Liliana Sikorska

    Directory of Open Access Journals (Sweden)

    Mirosława Buchholtz

    2017-10-01

    Full Text Available The concept of humanity has taken on new meanings in the era of posthumanist debate. Engaging both prehumanist and posthumanist perspectives, Liliana Sikorska strips away layers of cognitive mappings performed over hundreds of years in Western culture to expose in her recent essay the mechanisms that have exacerbated the East–West divide. While the majority of discussed texts come from medieval and Victorian literature and culture, it becomes obvious to the reader of her book that the issues she explores are still haunting the lives of people and nations worldwide today.

  12. Can Babies Learn to Read? A Randomized Trial of Baby Media

    Science.gov (United States)

    Neuman, Susan B.; Kaefer, Tanya; Pinkham, Ashley; Strouse, Gabrielle

    2014-01-01

    Targeted to children as young as 3 months old, there is a growing number of baby media products that claim to teach babies to read. This randomized controlled trial was designed to examine this claim by investigating the effects of a best-selling baby media product on reading development. One hundred and seventeen infants, ages 9 to 18 months,…

  13. Randomized Controlled Trial of Social Media: Effect of Increased Intensity of the Intervention.

    Science.gov (United States)

    Fox, Caroline S; Gurary, Ellen B; Ryan, John; Bonaca, Marc; Barry, Karen; Loscalzo, Joseph; Massaro, Joseph

    2016-04-27

    A prior randomized controlled trial of social media exposure at Circulation determined that social media did not increase 30-day page views. Whether insufficient social media intensity contributed to these results is uncertain. Original article manuscripts were randomized to social media exposure compared with no social media exposure (control) at Circulation beginning in January 2015. Social media exposure consisted of Facebook and Twitter posts on the journal's accounts. To increase social media intensity, a larger base of followers was built using advertising and organic growth, and posts were presented in triplicate and boosted on Facebook and retweeted on Twitter. The primary outcome was 30-day page views. Stopping rules were established at the point that 50% of the manuscripts were randomized and had 30-day follow-up to compare groups on 30-day page views. The trial was stopped for futility on September 26, 2015. Overall, 74 manuscripts were randomized to receive social media exposure, and 78 manuscripts were randomized to the control arm. The intervention and control arms were similar based on article type (P=0.85), geographic location of the corresponding author (P=0.33), and whether the manuscript had an editorial (P=0.80). Median number of 30-day page views was 499.5 in the social media arm and 450.5 in the control arm; there was no evidence of a treatment effect (P=0.38). There were no statistically significant interactions of treatment by manuscript type (P=0.86), by corresponding author (P=0.35), by trimester of publication date (P=0.34), or by editorial status (P=0.79). A more intensive social media strategy did not result in increased 30-day page views of original research. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  14. Fluctuation theory for radiative transfer in random media

    International Nuclear Information System (INIS)

    Bal, Guillaume; Jing Wenjia

    2011-01-01

    We consider the effect of small scale random fluctuations of the constitutive coefficients on boundary measurements of solutions to radiative transfer equations. As the correlation length of the random oscillations tends to zero, the transport solution is well approximated by a deterministic, averaged, solution. In this paper, we analyze the random fluctuations to the averaged solution, which may be interpreted as a central limit correction to homogenization. With the inverse transport problem in mind, we characterize the random structure of the singular components of the transport measurement operator. In regimes of moderate scattering, such components provide stable reconstructions of the constitutive parameters in the transport equation. We show that the random fluctuations strongly depend on the decorrelation properties of the random medium.

  15. Condition for invariant spectrum of an electromagnetic wave scattered from an anisotropic random media.

    Science.gov (United States)

    Li, Jia; Wu, Pinghui; Chang, Liping

    2015-08-24

    Within the accuracy of the first-order Born approximation, sufficient conditions are derived for the invariance of spectrum of an electromagnetic wave, which is generated by the scattering of an electromagnetic plane wave from an anisotropic random media. We show that the following restrictions on properties of incident fields and the anisotropic media must be simultaneously satisfied: 1) the elements of the dielectric susceptibility matrix of the media must obey the scaling law; 2) the spectral components of the incident field are proportional to each other; 3) the second moments of the elements of the dielectric susceptibility matrix of the media are inversely proportional to the frequency.

  16. Long time tails in stationary random media. I. Theory

    NARCIS (Netherlands)

    Ernst, M.H.; Machta, J.; Dorfman, J.R.; Beijeren, H. van

    1984-01-01

    Diffusion of moving particles in stationary disordered media is studied using a phenomenological mode-coupling theory. The presence of disorder leads to a generalized diffusion equation, with memory kernels having power law long time tails. The velocity autocorrelation function is found to decay

  17. Experimental analysis of the flow near the boundary of random porous media

    Science.gov (United States)

    Wu, Zhenxing; Mirbod, Parisa

    2018-04-01

    The aim of this work is to experimentally examine flow over and near random porous media. Different porous materials were chosen to achieve porosity ranging from 0.95 to 0.99. In this study, we report the detailed velocity measurements of the flow over and near random porous material inside a rectangular duct using a planar particle image velocimetry (PIV) technique. By controlling the flow rate, two different Reynolds numbers were achieved. We determined the slip velocity at the interface between the porous media and free flow. Values of the slip velocity normalized either by the maximum flow velocity or by the shear rate at the interface and the screening distance K1/2 were found to depend on porosity. It was also shown that the depth of penetration inside the porous material was larger than the screening length using Brinkman's prediction. Moreover, we examined a model for the laminar coupled flow over and inside porous media and analyzed the permeability of a random porous medium. This study provided detailed analysis of flow over and at the interface of various specific random porous media using the PIV technique. This analysis has the potential to serve as a first step toward using random porous media as a new passive technique to control the flow over smooth surfaces.

  18. Uniformity transition for ray intensities in random media

    Science.gov (United States)

    Pradas, Marc; Pumir, Alain; Wilkinson, Michael

    2018-04-01

    This paper analyses a model for the intensity of distribution for rays propagating without absorption in a random medium. The random medium is modelled as a dynamical map. After N iterations, the intensity is modelled as a sum S of {{\\mathcal N}} contributions from different trajectories, each of which is a product of N independent identically distributed random variables x k , representing successive focussing or de-focussing events. The number of ray trajectories reaching a given point is assumed to proliferate exponentially: {{\\mathcal N}}=ΛN , for some Λ>1 . We investigate the probability distribution of S. We find a phase transition as parameters of the model are varied. There is a phase where the fluctuations of S are suppressed as N\\to ∞ , and a phase where the S has large fluctuations, for which we provide a large deviation analysis.

  19. Method of model reduction and multifidelity models for solute transport in random layered porous media

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhijie; Tartakovsky, Alexandre M.

    2017-09-01

    This work presents a hierarchical model for solute transport in bounded layered porous media with random permeability. The model generalizes the Taylor-Aris dispersion theory to stochastic transport in random layered porous media with a known velocity covariance function. In the hierarchical model, we represent (random) concentration in terms of its cross-sectional average and a variation function. We derive a one-dimensional stochastic advection-dispersion-type equation for the average concentration and a stochastic Poisson equation for the variation function, as well as expressions for the effective velocity and dispersion coefficient. We observe that velocity fluctuations enhance dispersion in a non-monotonic fashion: the dispersion initially increases with correlation length λ, reaches a maximum, and decreases to zero at infinity. Maximum enhancement can be obtained at the correlation length about 0.25 the size of the porous media perpendicular to flow.

  20. Development of random geometry capability in RMC code for stochastic media analysis

    International Nuclear Information System (INIS)

    Liu, Shichang; She, Ding; Liang, Jin-gang; Wang, Kan

    2015-01-01

    Highlights: • Monte Carlo method plays an important role in modeling of particle transport in random media. • Three stochastic geometry modeling methods have been developed in RMC. • The stochastic effects of the randomly dispersed fuel particles are analyzed. • Investigation of accuracy and efficiency of three methods has been carried out. • All the methods are effective, and explicit modeling is regarded as the best choice. - Abstract: Simulation of particle transport in random media poses a challenge for traditional deterministic transport methods, due to the significant effects of spatial and energy self-shielding. Monte Carlo method plays an important role in accurate simulation of random media, owing to its flexible geometry modeling and the use of continuous-energy nuclear cross sections. Three stochastic geometry modeling methods including Random Lattice Method, Chord Length Sampling and explicit modeling approach with mesh acceleration technique, have been developed in RMC to simulate the particle transport in the dispersed fuels. The verifications of the accuracy and the investigations of the calculation efficiency have been carried out. The stochastic effects of the randomly dispersed fuel particles are also analyzed. The results show that all three stochastic geometry modeling methods can account for the effects of the random dispersion of fuel particles, and the explicit modeling method can be regarded as the best choice

  1. Reporting of Randomized Trials in Common Cancers in the Lay Media.

    Science.gov (United States)

    Ribnikar, Domen; Goldvaser, Hadar; Ocana, Alberto; Templeton, Arnoud J; Seruga, Bostjan; Amir, Eitan

    2018-01-01

    Limited data exist about the role of the lay media in the dissemination of results of randomized controlled trials (RCTs) in common cancers. Completed phase III RCTs evaluating new drugs in common cancers between January 2005 and October 2016 were identified from ClinicalTrials.gov. Lay media reporting was identified by searching LexisNexis Academic. Scientific reporting was defined as presentation at an academic conference or publication in full. Associations between reporting in the lay media before scientific reporting and study design and sponsorship were evaluated using logistic regression. Of 180 RCTs identified, 52% were reported in the lay media and in 27%, lay media reporting occurred before scientific reporting with an increasing trend over time (p = 0.009). Reporting in the lay media before scientific reporting was associated with positive results (OR: 2.10, p = 0.04), targeted therapy compared to chemotherapy (OR: 4.75, p = 0.006), immunotherapy compared to chemotherapy (OR: 7.60, p = 0.02), and prostate cancer compared to breast cancer (OR: 3.25, p = 0.02). Over a quarter of all RCTs in common cancers are reported in the lay media before they are reported scientifically with an increasing proportion over time. Positive trials, studies in prostate cancer, and trials of immunotherapy are associated with early reporting in the lay media. © 2017 S. Karger AG, Basel.

  2. Trimethoprim-sulfamethoxazole in children with chronic otitis media: a randomized comparison of costs and effects.

    NARCIS (Netherlands)

    Boonacker, C.W.; Veen, E.L. van der; Wilt, G.J. van der; Schilder, A.G.M.; Rovers, M.M.

    2008-01-01

    OBJECTIVE: To study the cost-effectiveness of a 6- to 12-week course of high-dose oral trimethoprim-sulfamethoxazole in children with chronic active otitis media (COM). STUDY DESIGN: Cost-effectiveness study including both direct and indirect costs alongside a randomized placebo-controlled trial.

  3. Effects of a brief school-based media literacy intervention on digital media use in adolescents: cluster randomized controlled trial.

    Science.gov (United States)

    Walther, Birte; Hanewinkel, Reiner; Morgenstern, Matthis

    2014-09-01

    The aim of this study was to evaluate the effects of a four-session school-based media literacy curriculum on adolescent computer gaming and Internet use behavior. The study comprised a cluster randomized controlled trial with three assessments (baseline, posttest, and 12-month follow-up). At baseline, a total of 2,303 sixth and seventh grade adolescents from 27 secondary schools were assessed. Of these, 1,843 (80%) could be reached at all three assessments (Mage=12.0 years; SD=0.83). Students of the intervention group received the media literacy program Vernetzte www.Welten ("Connected www.Worlds ") implemented by trained teachers during class time. The control group attended regular class. Main outcome measures were adolescents' computer gaming and Internet use: days per month, hours per day, and addictive use patterns. Parental media monitoring and rules at home were assessed as secondary outcomes. Results of multilevel growth-curve models revealed a significant intervention effect in terms of a lower increase in self-reported gaming frequency (β = -1.10 [95% CI -2.06, -0.13]), gaming time (β = -0.27 [95% CI -0.40, -0.14]), and proportion of excessive gamers (AOR=0.21 [95% CI 0.08, 0.57]) in the intervention group. There were also significant group-time interactions for the addictive gaming scale (β=-0.08 [95% CI -0.12, -0.04]), and the Internet Addiction Scale (β = -0.06 [95% CI -0.10, -0.01]). No effect was found for days and hours of Internet use or parental media behavior. The study shows that the program Vernetzte www.Welten can influence adolescents' media use behavior. Future research should address mediating and moderating variables of program effects.

  4. Two spatial light modulator system for laboratory simulation of random beam propagation in random media.

    Science.gov (United States)

    Wang, Fei; Toselli, Italo; Korotkova, Olga

    2016-02-10

    An optical system consisting of a laser source and two independent consecutive phase-only spatial light modulators (SLMs) is shown to accurately simulate a generated random beam (first SLM) after interaction with a stationary random medium (second SLM). To illustrate the range of possibilities, a recently introduced class of random optical frames is examined on propagation in free space and several weak turbulent channels with Kolmogorov and non-Kolmogorov statistics.

  5. Incoherent neutron scattering functions for random jump diffusion in bounded and infinite media

    International Nuclear Information System (INIS)

    Hall, P.L.; Ross, D.K.

    1981-01-01

    The incoherent neutron scattering function for unbounded jump diffusion is calculated from random walk theory assuming a gaussian distribution of jump lengths. The method is then applied to calculate the scattering function for spatially bounded random jumps in one dimension. The dependence on momentum transfer of the quasi-elastic energy broadenings predicted by this model and a previous model for bounded one-dimensional continuous diffusion are calculated and compared with the predictions of models for diffusion in unbounded media. The one-dimensional solutions can readily be generalized to three dimensions to provide a description of quasi-elastic scattering of neutrons by molecules undergoing localized random motions. (author)

  6. Universality of Critically Pinned Interfaces in Two-Dimensional Isotropic Random Media

    Science.gov (United States)

    Grassberger, Peter

    2018-05-01

    Based on extensive simulations, we conjecture that critically pinned interfaces in two-dimensional isotropic random media with short-range correlations are always in the universality class of ordinary percolation. Thus, in contrast to interfaces in >2 dimensions, there is no distinction between fractal (i.e., percolative) and rough but nonfractal interfaces. Our claim includes interfaces in zero-temperature random field Ising models (both with and without spontaneous nucleation), in heterogeneous bootstrap percolation, and in susceptible-weakened-infected-removed epidemics. It does not include models with long-range correlations in the randomness and models where overhangs are explicitly forbidden (which would imply nonisotropy of the medium).

  7. Comparison of media literacy and usual education to prevent tobacco use: a cluster-randomized trial.

    Science.gov (United States)

    Primack, Brian A; Douglas, Erika L; Land, Stephanie R; Miller, Elizabeth; Fine, Michael J

    2014-02-01

    Media literacy programs have shown potential for reduction of adolescent tobacco use. We aimed to determine if an anti-smoking media literacy curriculum improves students' media literacy and affects factors related to adolescent smoking. We recruited 1170 9th-grade students from 64 classrooms in 3 public urban high schools. Students were randomized by classroom to a media literacy curriculum versus a standard educational program. In an intent-to-treat analysis, we used multilevel modeling to determine if changes in study outcomes were associated with the curricular intervention, controlling for baseline student covariates and the clustering of students within classrooms. Among participants, mean age was 14.5 years and 51% were male, with no significant differences in baseline characteristics between groups. Smoking media literacy changed more among intervention participants compared with control participants (0.24 vs. 0.08, p media literacy curriculum is more effective than a standard educational program in teaching media literacy and improving perceptions of the true prevalence of smoking among adolescents. © 2014, American School Health Association.

  8. Replica field theory for a polymer in random media

    International Nuclear Information System (INIS)

    Goldschmidt, Yadin Y.

    2000-01-01

    In this paper we revisit the problem of a (non-self-avoiding) polymer chain in a random medium which was previously investigated by Edwards and Muthukumar (EM) [J. Chem. Phys. 89, 2435 (1988)]. As noticed by Cates and Ball (CB) [J. Phys. (France) 49, 2009 (1988)] there is a discrepancy between the predictions of the replica calculation of EM and the expectation that in an infinite medium the quenched and annealed results should coincide (for a chain that is free to move) and a long polymer should always collapse. CB argued that only in a finite volume one might see a ''localization transition'' (or crossover) from a stretched to a collapsed chain in three spatial dimensions. Here we carry out the replica calculation in the presence of an additional confining harmonic potential that mimics the effect of a finite volume. Using a variational scheme with five variational parameters we derive analytically for d -1/(4-d) ∼(g ln V) -1/(4-d) , where R is the radius of gyration, g is the strength of the disorder, μ is the spring constant associated with the confining potential, and V is the associated effective volume of the system. Thus the EM result is recovered with their constant replaced by ln V as argued by CB. We see that in the strict infinite volume limit the polymer always collapses, but for finite volume a transition from a stretched to a collapsed form might be observed as a function of the strength of the disorder. For d V ' ∼exp(g 2/(2-d) L (4-d)/(2-d) ) the annealed results are recovered and R∼(Lg) 1/(d-2) , where L is the length of the polymer. Hence the polymer also collapses in the large L limit. The one-step replica symmetry breaking solution is crucial for obtaining the above results. (c) 2000 The American Physical Society

  9. First-principles modeling of electromagnetic scattering by discrete and discretely heterogeneous random media

    International Nuclear Information System (INIS)

    Mishchenko, Michael I.; Dlugach, Janna M.; Yurkin, Maxim A.; Bi, Lei; Cairns, Brian; Liu, Li; Panetta, R. Lee; Travis, Larry D.; Yang, Ping; Zakharova, Nadezhda T.

    2016-01-01

    A discrete random medium is an object in the form of a finite volume of a vacuum or a homogeneous material medium filled with quasi-randomly and quasi-uniformly distributed discrete macroscopic impurities called small particles. Such objects are ubiquitous in natural and artificial environments. They are often characterized by analyzing theoretically the results of laboratory, in situ, or remote-sensing measurements of the scattering of light and other electromagnetic radiation. Electromagnetic scattering and absorption by particles can also affect the energy budget of a discrete random medium and hence various ambient physical and chemical processes. In either case electromagnetic scattering must be modeled in terms of appropriate optical observables, i.e., quadratic or bilinear forms in the field that quantify the reading of a relevant optical instrument or the electromagnetic energy budget. It is generally believed that time-harmonic Maxwell’s equations can accurately describe elastic electromagnetic scattering by macroscopic particulate media that change in time much more slowly than the incident electromagnetic field. However, direct solutions of these equations for discrete random media had been impracticable until quite recently. This has led to a widespread use of various phenomenological approaches in situations when their very applicability can be questioned. Recently, however, a new branch of physical optics has emerged wherein electromagnetic scattering by discrete and discretely heterogeneous random media is modeled directly by using analytical or numerically exact computer solutions of the Maxwell equations. Therefore, the main objective of this Report is to formulate the general theoretical framework of electromagnetic scattering by discrete random media rooted in the Maxwell–Lorentz electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell–Lorentz equations, we trace the development

  10. First-principles modeling of electromagnetic scattering by discrete and discretely heterogeneous random media

    Science.gov (United States)

    Mishchenko, Michael I.; Dlugach, Janna M.; Yurkin, Maxim A.; Bi, Lei; Cairns, Brian; Liu, Li; Panetta, R. Lee; Travis, Larry D.; Yang, Ping; Zakharova, Nadezhda T.

    2018-01-01

    A discrete random medium is an object in the form of a finite volume of a vacuum or a homogeneous material medium filled with quasi-randomly and quasi-uniformly distributed discrete macroscopic impurities called small particles. Such objects are ubiquitous in natural and artificial environments. They are often characterized by analyzing theoretically the results of laboratory, in situ, or remote-sensing measurements of the scattering of light and other electromagnetic radiation. Electromagnetic scattering and absorption by particles can also affect the energy budget of a discrete random medium and hence various ambient physical and chemical processes. In either case electromagnetic scattering must be modeled in terms of appropriate optical observables, i.e., quadratic or bilinear forms in the field that quantify the reading of a relevant optical instrument or the electromagnetic energy budget. It is generally believed that time-harmonic Maxwell’s equations can accurately describe elastic electromagnetic scattering by macroscopic particulate media that change in time much more slowly than the incident electromagnetic field. However, direct solutions of these equations for discrete random media had been impracticable until quite recently. This has led to a widespread use of various phenomenological approaches in situations when their very applicability can be questioned. Recently, however, a new branch of physical optics has emerged wherein electromagnetic scattering by discrete and discretely heterogeneous random media is modeled directly by using analytical or numerically exact computer solutions of the Maxwell equations. Therefore, the main objective of this Report is to formulate the general theoretical framework of electromagnetic scattering by discrete random media rooted in the Maxwell–Lorentz electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell–Lorentz equations, we trace the development

  11. First-principles modeling of electromagnetic scattering by discrete and discretely heterogeneous random media

    Energy Technology Data Exchange (ETDEWEB)

    Mishchenko, Michael I., E-mail: michael.i.mishchenko@nasa.gov [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States); Dlugach, Janna M. [Main Astronomical Observatory of the National Academy of Sciences of Ukraine, 27 Zabolotny Str., 03680, Kyiv (Ukraine); Yurkin, Maxim A. [Voevodsky Institute of Chemical Kinetics and Combustion, SB RAS, Institutskaya str. 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova 2, 630090 Novosibirsk (Russian Federation); Bi, Lei [Department of Atmospheric Sciences, Texas A& M University, College Station, TX 77843 (United States); Cairns, Brian [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States); Liu, Li [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States); Columbia University, 2880 Broadway, New York, NY 10025 (United States); Panetta, R. Lee [Department of Atmospheric Sciences, Texas A& M University, College Station, TX 77843 (United States); Travis, Larry D. [NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025 (United States); Yang, Ping [Department of Atmospheric Sciences, Texas A& M University, College Station, TX 77843 (United States); Zakharova, Nadezhda T. [Trinnovim LLC, 2880 Broadway, New York, NY 10025 (United States)

    2016-05-16

    A discrete random medium is an object in the form of a finite volume of a vacuum or a homogeneous material medium filled with quasi-randomly and quasi-uniformly distributed discrete macroscopic impurities called small particles. Such objects are ubiquitous in natural and artificial environments. They are often characterized by analyzing theoretically the results of laboratory, in situ, or remote-sensing measurements of the scattering of light and other electromagnetic radiation. Electromagnetic scattering and absorption by particles can also affect the energy budget of a discrete random medium and hence various ambient physical and chemical processes. In either case electromagnetic scattering must be modeled in terms of appropriate optical observables, i.e., quadratic or bilinear forms in the field that quantify the reading of a relevant optical instrument or the electromagnetic energy budget. It is generally believed that time-harmonic Maxwell’s equations can accurately describe elastic electromagnetic scattering by macroscopic particulate media that change in time much more slowly than the incident electromagnetic field. However, direct solutions of these equations for discrete random media had been impracticable until quite recently. This has led to a widespread use of various phenomenological approaches in situations when their very applicability can be questioned. Recently, however, a new branch of physical optics has emerged wherein electromagnetic scattering by discrete and discretely heterogeneous random media is modeled directly by using analytical or numerically exact computer solutions of the Maxwell equations. Therefore, the main objective of this Report is to formulate the general theoretical framework of electromagnetic scattering by discrete random media rooted in the Maxwell–Lorentz electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell–Lorentz equations, we trace the development

  12. Non-classical radiation transport in random media with fluctuating densities

    International Nuclear Information System (INIS)

    Dyuldya, S.V.; Bratchenko, M.I.

    2012-01-01

    The ensemble averaged propagation kernels of the non-classical radiation transport are studied by means of the proposed application of the stochastic differential equation random medium generators. It is shown that the non-classical transport is favored in long-correlated weakly fluctuating media. The developed kernel models have been implemented in GEANT4 and validated against the d ouble Monte Carlo m odeling of absorptions curves of disperse neutron absorbers and γ-albedos from a scatterer/absorber random mix

  13. A scaling analysis of electronic localization in two-dimensional random media

    International Nuclear Information System (INIS)

    Ye Zhen

    2003-01-01

    By an improved scaling analysis, we suggest that there may appear two possibilities concerning the electronic localization in two-dimensional random media. The first is that all electronic states are localized in two dimensions, as conjectured previously. The second possibility is that electronic behaviors in two- and three-dimensional random systems are similar, in agreement with a recent calculation based on a direct calculation of the conductance with the use of the Kubo formula. In this case, non-localized states are possible in two dimensions, and have some peculiar properties. A few predictions are proposed. Moreover, the present analysis accommodates results from the previous scaling analysis

  14. First-Principles Modeling Of Electromagnetic Scattering By Discrete and Discretely Heterogeneous Random Media

    Science.gov (United States)

    Mishchenko, Michael I.; Dlugach, Janna M.; Yurkin, Maxim A.; Bi, Lei; Cairns, Brian; Liu, Li; Panetta, R. Lee; Travis, Larry D.; Yang, Ping; Zakharova, Nadezhda T.

    2016-01-01

    A discrete random medium is an object in the form of a finite volume of a vacuum or a homogeneous material medium filled with quasi-randomly and quasi-uniformly distributed discrete macroscopic impurities called small particles. Such objects are ubiquitous in natural and artificial environments. They are often characterized by analyzing theoretically the results of laboratory, in situ, or remote-sensing measurements of the scattering of light and other electromagnetic radiation. Electromagnetic scattering and absorption by particles can also affect the energy budget of a discrete random medium and hence various ambient physical and chemical processes. In either case electromagnetic scattering must be modeled in terms of appropriate optical observables, i.e., quadratic or bilinear forms in the field that quantify the reading of a relevant optical instrument or the electromagnetic energy budget. It is generally believed that time-harmonic Maxwell's equations can accurately describe elastic electromagnetic scattering by macroscopic particulate media that change in time much more slowly than the incident electromagnetic field. However, direct solutions of these equations for discrete random media had been impracticable until quite recently. This has led to a widespread use of various phenomenological approaches in situations when their very applicability can be questioned. Recently, however, a new branch of physical optics has emerged wherein electromagnetic scattering by discrete and discretely heterogeneous random media is modeled directly by using analytical or numerically exact computer solutions of the Maxwell equations. Therefore, the main objective of this Report is to formulate the general theoretical framework of electromagnetic scattering by discrete random media rooted in the Maxwell- Lorentz electromagnetics and discuss its immediate analytical and numerical consequences. Starting from the microscopic Maxwell-Lorentz equations, we trace the development of

  15. Echinacea purpurea and osteopathic manipulative treatment in children with recurrent otitis media: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Worden Katherine A

    2008-10-01

    Full Text Available Abstract Background Recurrent otitis media is a common problem in young children. Echinacea and osteopathic manipulative treatment have been proposed as preventive measures, but have been inadequately studied. This study was designed to assess the efficacy of Echinacea purpurea and/or osteopathic manipulative treatment (OMT for prevention of acute otitis media in otitis-prone children. Methods A randomized, placebo-controlled, two-by-two factorial trial with 6-month follow-up, conducted 1999 – 2002 in Tucson, Arizona. Patients were aged 12–60 months with recurrent otitis media, defined as three or more separate episodes of acute otitis media within six months, or at least four episodes in one year. Ninety children (44% white non-Hispanic, 39% Hispanic, 57% male were enrolled, of which 84 had follow-up for at least 3 months. Children were randomly assigned to one of four protocol groups: double placebo, echinacea plus sham OMT, true OMT (including cranial manipulation plus placebo echinacea, or true echinacea plus OMT. An alcohol extract of Echinacea purpurea roots and seeds (or placebo was administered for 10 days at the first sign of each common cold. Five OMT visits (or sham treatments were offered over 3 months. Results No interaction was found between echinacea and OMT. Echinacea was associated with a borderline increased risk of having at least one episode of acute otitis media during 6-month follow-up compared to placebo (65% versus 41%; relative risk, 1.59, 95% CI 1.04, 2.42. OMT did not significantly affect risk compared to sham (44% versus 61%; relative risk, 0.72, 95% CI 0.48, 1.10. Conclusion In otitis-prone young children, treating colds with this form of echinacea does not decrease the risk of acute otitis media, and may in fact increase risk. A regimen of up to five osteopathic manipulative treatments does not significantly decrease the risk of acute otitis media. Trial registration ClinicalTrials.gov Identifier: NCT00010465

  16. Parent-child interactions during traditional and interactive media settings: A pilot randomized control study.

    Science.gov (United States)

    Skaug, Silje; Englund, Kjellrun T; Saksvik-Lehouillier, Ingvild; Lydersen, Stian; Wichstrøm, Lars

    2018-04-01

    Parent-child interactions are pivotal for children's socioemotional development, yet might suffer with increased attention to screen media, as research has suggested. In response, we hypothesized that parent-child play on a tablet computer, as representative of interactive media, would generate higher-quality parent-child interactions than toy play or watching TV. We examined the emotional availability of mothers and their 2-year-old child during the previous three contexts using a randomized crossover design (n = 22) in a laboratory room. Among other results, mothers were more sensitive and structuring during joint gaming on a tablet than when engaged in toy play or watching TV. In addition, mothers were more hostile toward their children during play with traditional toys than during joint tablet gaming and television co-viewing. Such findings provide new insights into the impact of new media on parent-child interactions, chiefly by demonstrating that interactive media devices such as tablets can afford growth-enhancing parent-child interactions. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  17. Adjunctive social media for more effective contraceptive counseling: a randomized controlled trial.

    Science.gov (United States)

    Kofinas, Jason D; Varrey, Aneesha; Sapra, Katherine J; Kanj, Rula V; Chervenak, Frank A; Asfaw, Tirsit

    2014-04-01

    To determine whether social media, specifically Facebook, is an effective tool for improving contraceptive knowledge. English-speaking women aged 18-45 years receiving care at an urban academic center obstetrics and gynecology clinic were included and randomized to a trial of standard contraceptive education and pamphlet (n=74) compared with standard contraceptive education and Facebook (n=69) information for contraception counseling. Contraceptive knowledge was evaluated preintervention and postintervention by the Contraceptive Knowledge Inventory. We evaluated the effect of the intervention by raw score and percent increase in Contraceptive Knowledge Inventory score, participant satisfaction with counseling method, and contraceptive preference postintervention. All analyses were stratified by age group. The median raw postintervention Contraceptive Knowledge Inventory score was significantly higher in the Facebook compared with the pamphlet group (15 compared with 12, PSocial media as an adjunct to traditional in-office counseling improves patient contraceptive knowledge and increases patient preference for LARCs. ClinicalTrials.gov, www.clinicaltrials.gov, NCT01994005.

  18. Models of disordered media: some new results, including some new connections between composite-media, fluid-state, and random-flight theories

    International Nuclear Information System (INIS)

    Stell, G.

    1983-01-01

    Some new theoretical results on the microstructure of models of two-phase disordered media are given, as well as the new quantitative bounds on the thermal conductivity that follows for one such model (randomly centered spherical inclusions). A second set of results is then given for random flights, including random flights with hit expectancy prescribed in a unit hall around the flight origin. Finally, some interesting correspondences are demonstrated, via the Ornstein-Zernike equation, between random-flight results, liquid-state results and percolation-theory results. 27 references, 6 figures, 4 tables

  19. A continuous time random walk model for Darcy-scale anomalous transport in heterogeneous porous media.

    Science.gov (United States)

    Comolli, Alessandro; Hakoun, Vivien; Dentz, Marco

    2017-04-01

    Achieving the understanding of the process of solute transport in heterogeneous porous media is of crucial importance for several environmental and social purposes, ranging from aquifers contamination and remediation, to risk assessment in nuclear waste repositories. The complexity of this aim is mainly ascribable to the heterogeneity of natural media, which can be observed at all the scales of interest, from pore scale to catchment scale. In fact, the intrinsic heterogeneity of porous media is responsible for the arising of the well-known non-Fickian footprints of transport, including heavy-tailed breakthrough curves, non-Gaussian spatial density profiles and the non-linear growth of the mean squared displacement. Several studies investigated the processes through which heterogeneity impacts the transport properties, which include local modifications to the advective-dispersive motion of solutes, mass exchanges between some mobile and immobile phases (e.g. sorption/desorption reactions or diffusion into solid matrix) and spatial correlation of the flow field. In the last decades, the continuous time random walk (CTRW) model has often been used to describe solute transport in heterogenous conditions and to quantify the impact of point heterogeneity, spatial correlation and mass transfer on the average transport properties [1]. Open issues regarding this approach are the possibility to relate measurable properties of the medium to the parameters of the model, as well as its capability to provide predictive information. In a recent work [2] the authors have shed new light on understanding the relationship between Lagrangian and Eulerian dynamics as well as on their evolution from arbitrary initial conditions. On the basis of these results, we derive a CTRW model for the description of Darcy-scale transport in d-dimensional media characterized by spatially random permeability fields. The CTRW approach models particle velocities as a spatial Markov process, which is

  20. Elliptic random-walk equation for suspension and tracer transport in porous media

    DEFF Research Database (Denmark)

    Shapiro, Alexander; Bedrikovetsky, P. G.

    2008-01-01

    . The new theory predicts delay of the maximum of the tracer, compared to the velocity of the flow, while its forward "tail" contains much more particles than in the solution of the classical parabolic (advection-dispersion) equation. This is in agreement with the experimental observations and predictions......We propose a new approach to transport of the suspensions and tracers in porous media. The approach is based on a modified version of the continuous time random walk (CTRW) theory. In the framework of this theory we derive an elliptic transport equation. The new equation contains the time...... of the CTRW theory. (C) 2008 Elsevier B.V. All rights reserved....

  1. Analysis and Computation of Acoustic and Elastic Wave Equations in Random Media

    KAUST Repository

    Motamed, Mohammad

    2014-01-06

    We propose stochastic collocation methods for solving the second order acoustic and elastic wave equations in heterogeneous random media and subject to deterministic boundary and initial conditions [1, 4]. We assume that the medium consists of non-overlapping sub-domains with smooth interfaces. In each sub-domain, the materials coefficients are smooth and given or approximated by a finite number of random variable. One important example is wave propagation in multi-layered media with smooth interfaces. 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. We provide a rigorous convergence analysis and demonstrate different types of convergence of the probability error with respect to the number of collocation points under some regularity assumptions on the data. In particular, we show that, unlike in elliptic and parabolic problems [2, 3], the solution to hyperbolic problems is not in general analytic with respect to the random variables. Therefore, the rate of convergence is only algebraic. A fast spectral rate of convergence is still possible for some quantities of interest and for the wave solutions with particular types of data. We also show that the semi-discrete solution is analytic with respect to the random variables with the radius of analyticity proportional to the grid/mesh size h. We therefore obtain an exponential rate of convergence which deteriorates as the quantity h p gets smaller, with p representing the polynomial degree in the stochastic space. We have shown that analytical results and numerical examples are consistent and that the stochastic collocation method may be a valid alternative to the more traditional Monte Carlo method. Here we focus on the stochastic acoustic wave equation. Similar results are obtained for stochastic elastic equations.

  2. Planar spatial correlations, anisotropy, and specific surface area of stationary random porous media

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1998-01-01

    An earlier result of the author showed that an anisotropic spatial correlation function of a random porous medium could be used to compute the specific surface area when it is stationary as well as anisotropic by first performing a three-dimensional radial average and then taking the first derivative with respect to lag at the origin. This result generalized the earlier result for isotropic porous media of Debye et al. [J. Appl. Phys. 28, 679 (1957)]. The present article provides more detailed information about the use of spatial correlation functions for anisotropic porous media and in particular shows that, for stationary anisotropic media, the specific surface area can be related to the derivative of the two-dimensional radial average of the correlation function measured from cross sections taken through the anisotropic medium. The main concept is first illustrated using a simple pedagogical example for an anisotropic distribution of spherical voids. Then, a general derivation of formulas relating the derivative of the planar correlation functions to surface integrals is presented. When the surface normal is uniformly distributed (as is the case for any distribution of spherical voids), our formulas can be used to relate a specific surface area to easily measurable quantities from any single cross section. When the surface normal is not distributed uniformly (as would be the case for an oriented distribution of ellipsoidal voids), our results show how to obtain valid estimates of specific surface area by averaging measurements on three orthogonal cross sections. One important general observation for porous media is that the surface area from nearly flat cracks may be underestimated from measurements on orthogonal cross sections if any of the cross sections happen to lie in the plane of the cracks. This result is illustrated by taking the very small aspect ratio (penny-shaped crack) limit of an oblate spheroid, but holds for other types of flat surfaces as well

  3. Randomized controlled pilot study to compare Homeopathy and Conventional therapy in Acute Otitis Media.

    Science.gov (United States)

    Sinha, M N; Siddiqui, V A; Nayak, C; Singh, Vikram; Dixit, Rupali; Dewan, Deepti; Mishra, Alok

    2012-01-01

    To compare the effectiveness of Homeopathy and Conventional therapy in Acute Otitis Media (AOM). A randomized placebo-controlled parallel group pilot study of homeopathic vs conventional treatment for AOM was conducted in Jaipur, India. Patients were randomized by a computer generated random number list to receive either individualized homeopathic medicines in fifty millesimal (LM) potencies, or conventional treatment including analgesics, antipyretics and anti-inflammatory drugs. Patients who did not improve were prescribed antibiotics at the 3rd day. Outcomes were assessed by the Acute Otitis Media-Severity of Symptoms (AOM-SOS) Scale and Tympanic Membrane Examination over 21 days. 81 patients were included, 80 completed follow-up: 41 for conventional and 40 for homeopathic treatment. In the Conventional group, all 40 (100%) patients were cured, in the Homeopathy group, 38 (95%) patients were cured while 02 (5%) patients were lost to the last two follow-up. By the 3rd day of treatment, 4 patients were cured in Homeopathy group but in Conventional group only one patient was cured. In the Conventional group antibiotics were prescribed in 39 (97.5%), no antibiotics were required in the Homeopathy group. 85% of patients were prescribed six homeopathic medicines. Individualized homeopathy is an effective conventional treatment in AOM, there were no significant differences between groups in the main outcome. Symptomatic improvement was quicker in the Homeopathy group, and there was a large difference in antibiotic requirements, favouring homeopathy. Further work on a larger scale should be conducted. Copyright © 2011 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

  4. Engaging Moms on Teen Indoor Tanning Through Social Media: Protocol of a Randomized Controlled Trial.

    Science.gov (United States)

    Pagoto, Sherry L; Baker, Katie; Griffith, Julia; Oleski, Jessica L; Palumbo, Ashley; Walkosz, Barbara J; Hillhouse, Joel; Henry, Kimberly L; Buller, David B

    2016-11-29

    . This trial will deliver social media content grounded in theory and will test it in a randomized design with state-of-the-art measures. This will contribute much needed insights on how to employ social media for health behavior change and disease prevention both for indoor tanning and other health risk behaviors and inform future social media efforts by public health and health care organizations. Clinicaltrials.gov NCT02835807; https://clinicaltrials.gov/ct2/show/NCT02835807 (Archived by WebCite at http://www.webcitation.org/6mDMICcCE). ©Sherry L Pagoto, Katie Baker, Julia Griffith, Jessica L Oleski, Ashley Palumbo, Barbara J Walkosz, Joel Hillhouse, Kimberly L Henry, David B Buller. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 29.11.2016.

  5. Engaging Moms on Teen Indoor Tanning Through Social Media: Protocol of a Randomized Controlled Trial

    Science.gov (United States)

    Baker, Katie; Griffith, Julia; Oleski, Jessica L; Palumbo, Ashley; Walkosz, Barbara J; Hillhouse, Joel; Henry, Kimberly L; Buller, David B

    2016-01-01

    anticipate completing this study by October 2019. Conclusions This trial will deliver social media content grounded in theory and will test it in a randomized design with state-of-the-art measures. This will contribute much needed insights on how to employ social media for health behavior change and disease prevention both for indoor tanning and other health risk behaviors and inform future social media efforts by public health and health care organizations. ClinicalTrial Clinicaltrials.gov NCT02835807; https://clinicaltrials.gov/ct2/show/NCT02835807 (Archived by WebCite at http://www.webcitation.org/6mDMICcCE). PMID:27899339

  6. Media Use and Source Trust among Muslims in Seven Countries: Results of a Large Random Sample Survey

    Directory of Open Access Journals (Sweden)

    Steven R. Corman

    2013-12-01

    Full Text Available Despite the perceived importance of media in the spread of and resistance against Islamist extremism, little is known about how Muslims use different kinds of media to get information about religious issues, and what sources they trust when doing so. This paper reports the results of a large, random sample survey among Muslims in seven countries Southeast Asia, West Africa and Western Europe, which helps fill this gap. Results show a diverse set of profiles of media use and source trust that differ by country, with overall low trust in mediated sources of information. Based on these findings, we conclude that mass media is still the most common source of religious information for Muslims, but that trust in mediated information is low overall. This suggests that media are probably best used to persuade opinion leaders, who will then carry anti-extremist messages through more personal means.

  7. Lattice Boltzmann simulation of flow and heat transfer in random porous media constructed by simulated annealing algorithm

    International Nuclear Information System (INIS)

    Liu, Minghua; Shi, Yong; Yan, Jiashu; Yan, Yuying

    2017-01-01

    Highlights: • A numerical capability combining the lattice Boltzmann method with simulated annealing algorithm is developed. • Digitized representations of random porous media are constructed using limited but meaningful statistical descriptors. • Pore-scale flow and heat transfer information in random porous media is obtained by the lattice Boltzmann simulation. • The effective properties at the representative elementary volume scale are well specified using appropriate upscale averaging. - Abstract: In this article, the lattice Boltzmann (LB) method for transport phenomena is combined with the simulated annealing (SA) algorithm for digitized porous-medium construction to study flow and heat transfer in random porous media. Importantly, in contrast to previous studies which simplify porous media as arrays of regularly shaped objects or effective pore networks, the LB + SA method in this article can model statistically meaningful random porous structures in irregular morphology, and simulate pore-scale transport processes inside them. Pore-scale isothermal flow and heat conduction in a set of constructed random porous media characterized by statistical descriptors were then simulated through use of the LB + SA method. The corresponding averages over the computational volumes and the related effective transport properties were also computed based on these pore scale numerical results. Good agreement between the numerical results and theoretical predictions or experimental data on the representative elementary volume scale was found. The numerical simulations in this article demonstrate combination of the LB method with the SA algorithm is a viable and powerful numerical strategy for simulating transport phenomena in random porous media in complex geometries.

  8. A random walk approach to the diffusion of positrons in gaseous media

    International Nuclear Information System (INIS)

    Girardi-Schappo, M.; Tenfen, W.; Arretche, F.

    2013-01-01

    In this work, we present a random walk model to study the positron diffusion in gaseous media. The positron-atom interaction is described through positron-target cross sections. The main idea is to obtain how much energy a positron transfer to the environment atoms, through ionizations and electronic excitations until its annihilation, taking the ratio between each energetically available collision channel to the total one as the probability for each process to occur. As a first application, we studied how the positron diffuse in gases of helium, neon, argon and their mixtures. To characterize the positron dynamics in each system, we calculated the radiation profile generated from the annihilation, their diffusion profiles and the most probable distances for excitation and ionization. (authors)

  9. Effect of particle size distribution on permeability in the randomly packed porous media

    Science.gov (United States)

    Markicevic, Bojan

    2017-11-01

    An answer of how porous medium heterogeneity influences the medium permeability is still inconclusive, where both increase and decrease in the permeability value are reported. A numerical procedure is used to generate a randomly packed porous material consisting of spherical particles. Six different particle size distributions are used including mono-, bi- and three-disperse particles, as well as uniform, normal and log-normal particle size distribution with the maximum to minimum particle size ratio ranging from three to eight for different distributions. In all six cases, the average particle size is kept the same. For all media generated, the stochastic homogeneity is checked from distribution of three coordinates of particle centers, where uniform distribution of x-, y- and z- positions is found. The medium surface area remains essentially constant except for bi-modal distribution in which medium area decreases, while no changes in the porosity are observed (around 0.36). The fluid flow is solved in such domain, and after checking for the pressure axial linearity, the permeability is calculated from the Darcy law. The permeability comparison reveals that the permeability of the mono-disperse medium is smallest, and the permeability of all poly-disperse samples is less than ten percent higher. For bi-modal particles, the permeability is for a quarter higher compared to the other media which can be explained by volumetric contribution of larger particles and larger passages for fluid flow to take place.

  10. A stochastic multiscale framework for modeling flow through random heterogeneous porous media

    International Nuclear Information System (INIS)

    Ganapathysubramanian, B.; Zabaras, N.

    2009-01-01

    Flow through porous media is ubiquitous, occurring from large geological scales down to the microscopic scales. Several critical engineering phenomena like contaminant spread, nuclear waste disposal and oil recovery rely on accurate analysis and prediction of these multiscale phenomena. Such analysis is complicated by inherent uncertainties as well as the limited information available to characterize the system. Any realistic modeling of these transport phenomena has to resolve two key issues: (i) the multi-length scale variations in permeability that these systems exhibit, and (ii) the inherently limited information available to quantify these property variations that necessitates posing these phenomena as stochastic processes. A stochastic variational multiscale formulation is developed to incorporate uncertain multiscale features. A stochastic analogue to a mixed multiscale finite element framework is used to formulate the physical stochastic multiscale process. Recent developments in linear and non-linear model reduction techniques are used to convert the limited information available about the permeability variation into a viable stochastic input model. An adaptive sparse grid collocation strategy is used to efficiently solve the resulting stochastic partial differential equations (SPDEs). The framework is applied to analyze flow through random heterogeneous media when only limited statistics about the permeability variation are given

  11. Upscaling solute transport in naturally fractured porous media with the continuous time random walk method

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, S.; Cortis, A.; Birkholzer, J.T.

    2010-04-01

    Solute transport in fractured porous media is typically 'non-Fickian'; that is, it is characterized by early breakthrough and long tailing and by nonlinear growth of the Green function-centered second moment. This behavior is due to the effects of (1) multirate diffusion occurring between the highly permeable fracture network and the low-permeability rock matrix, (2) a wide range of advection rates in the fractures and, possibly, the matrix as well, and (3) a range of path lengths. As a consequence, prediction of solute transport processes at the macroscale represents a formidable challenge. Classical dual-porosity (or mobile-immobile) approaches in conjunction with an advection-dispersion equation and macroscopic dispersivity commonly fail to predict breakthrough of fractured porous media accurately. It was recently demonstrated that the continuous time random walk (CTRW) method can be used as a generalized upscaling approach. Here we extend this work and use results from high-resolution finite element-finite volume-based simulations of solute transport in an outcrop analogue of a naturally fractured reservoir to calibrate the CTRW method by extracting a distribution of retention times. This procedure allows us to predict breakthrough at other model locations accurately and to gain significant insight into the nature of the fracture-matrix interaction in naturally fractured porous reservoirs with geologically realistic fracture geometries.

  12. Lattice Boltzmann simulation of the gas-solid adsorption process in reconstructed random porous media

    Science.gov (United States)

    Zhou, L.; Qu, Z. G.; Ding, T.; Miao, J. Y.

    2016-04-01

    The gas-solid adsorption process in reconstructed random porous media is numerically studied with the lattice Boltzmann (LB) method at the pore scale with consideration of interparticle, interfacial, and intraparticle mass transfer performances. Adsorbent structures are reconstructed in two dimensions by employing the quartet structure generation set approach. To implement boundary conditions accurately, all the porous interfacial nodes are recognized and classified into 14 types using a proposed universal program called the boundary recognition and classification program. The multiple-relaxation-time LB model and single-relaxation-time LB model are adopted to simulate flow and mass transport, respectively. The interparticle, interfacial, and intraparticle mass transfer capacities are evaluated with the permeability factor and interparticle transfer coefficient, Langmuir adsorption kinetics, and the solid diffusion model, respectively. Adsorption processes are performed in two groups of adsorbent media with different porosities and particle sizes. External and internal mass transfer resistances govern the adsorption system. A large porosity leads to an early time for adsorption equilibrium because of the controlling factor of external resistance. External and internal resistances are dominant at small and large particle sizes, respectively. Particle size, under which the total resistance is minimum, ranges from 3 to 7 μm with the preset parameters. Pore-scale simulation clearly explains the effect of both external and internal mass transfer resistances. The present paper provides both theoretical and practical guidance for the design and optimization of adsorption systems.

  13. Correspondence between sound propagation in discrete and continuous random media with application to forest acoustics.

    Science.gov (United States)

    Ostashev, Vladimir E; Wilson, D Keith; Muhlestein, Michael B; Attenborough, Keith

    2018-02-01

    Although sound propagation in a forest is important in several applications, there are currently no rigorous yet computationally tractable prediction methods. Due to the complexity of sound scattering in a forest, it is natural to formulate the problem stochastically. In this paper, it is demonstrated that the equations for the statistical moments of the sound field propagating in a forest have the same form as those for sound propagation in a turbulent atmosphere if the scattering properties of the two media are expressed in terms of the differential scattering and total cross sections. Using the existing theories for sound propagation in a turbulent atmosphere, this analogy enables the derivation of several results for predicting forest acoustics. In particular, the second-moment parabolic equation is formulated for the spatial correlation function of the sound field propagating above an impedance ground in a forest with micrometeorology. Effective numerical techniques for solving this equation have been developed in atmospheric acoustics. In another example, formulas are obtained that describe the effect of a forest on the interference between the direct and ground-reflected waves. The formulated correspondence between wave propagation in discrete and continuous random media can also be used in other fields of physics.

  14. Happy ending: a randomized controlled trial of a digital multi-media smoking cessation intervention.

    Science.gov (United States)

    Brendryen, Håvar; Kraft, Pål

    2008-03-01

    To assess the long-term efficacy of a fully automated digital multi-media smoking cessation intervention. Two-arm randomized control trial (RCT). Setting World Wide Web (WWW) study based in Norway. Subjects (n = 396) were recruited via internet advertisements and assigned randomly to conditions. Inclusion criteria were willingness to quit smoking and being aged 18 years or older. The treatment group received the internet- and cell-phone-based Happy Ending intervention. The intervention programme lasted 54 weeks and consisted of more than 400 contacts by e-mail, web-pages, interactive voice response (IVR) and short message service (SMS) technology. The control group received a self-help booklet. Additionally, both groups were offered free nicotine replacement therapy (NRT). Abstinence was defined as 'not even a puff of smoke, for the last 7 days', and assessed by means of internet surveys or telephone interviews. The main outcome was repeated point abstinence at 1, 3, 6 and 12 months following cessation. Participants in the treatment group reported clinically and statistically significantly higher repeated point abstinence rates than control participants [22.3% versus 13.1%; odds ratio (OR) = 1.91, 95% confidence interval (CI): 1.12-3.26, P = 0.02; intent-to-treat). Improved adherence to NRT and a higher level of post-cessation self-efficacy were observed in the treatment group compared with the control group. As the first RCT documenting the long-term treatment effects of such an intervention, this study adds to the promise of digital media in supporting behaviour change.

  15. Lack of efficacy of a decongestant-antihistamine combination for otitis media with effusion ("secretory" otitis media) in children. Results of a double-blind, randomized trial.

    Science.gov (United States)

    Cantekin, E I; Mandel, E M; Bluestone, C D; Rockette, H E; Paradise, J L; Stool, S E; Fria, T J; Rogers, K D

    1983-02-10

    In a double-blind, randomized trial of 553 infants and children who had otitis media with effusion ("secretory" otitis media), we compared the efficacy of a four-week course of an oral decongestant-antihistamine combination (pseudoephedrine hydrochloride, 4 mg per kilogram of body weight per day, and chlorpheniramine maleate, 0.35 mg per kilogram per day) with that of placebo. Among patients with initially unilateral disease, resolution of middle-ear effusion occurred at four weeks in 38 per cent of those treated with placebo and 34 per cent of those treated with drug (P = 0.74). Among patients with initially bilateral disease the corresponding proportions were 19 and 21 per cent, respectively (P = 0.67). Side effects were reported more often among drug-treated than placebo-treated patients. Decongestant-antihistamine combinations do not appear to be indicated for the treatment of otitis media with effusion in infants and children.

  16. Depletion benchmarks calculation of random media using explicit modeling approach of RMC

    International Nuclear Information System (INIS)

    Liu, Shichang; She, Ding; Liang, Jin-gang; Wang, Kan

    2016-01-01

    Highlights: • Explicit modeling of RMC is applied to depletion benchmark for HTGR fuel element. • Explicit modeling can provide detailed burnup distribution and burnup heterogeneity. • The results would serve as a supplement for the HTGR fuel depletion benchmark. • The method of adjacent burnup regions combination is proposed for full-core problems. • The combination method can reduce memory footprint, keeping the computing accuracy. - Abstract: Monte Carlo method plays an important role in accurate simulation of random media, owing to its advantages of the flexible geometry modeling and the use of continuous-energy nuclear cross sections. Three stochastic geometry modeling methods including Random Lattice Method, Chord Length Sampling and explicit modeling approach with mesh acceleration technique, have been implemented in RMC to simulate the particle transport in the dispersed fuels, in which the explicit modeling method is regarded as the best choice. In this paper, the explicit modeling method is applied to the depletion benchmark for HTGR fuel element, and the method of combination of adjacent burnup regions has been proposed and investigated. The results show that the explicit modeling can provide detailed burnup distribution of individual TRISO particles, and this work would serve as a supplement for the HTGR fuel depletion benchmark calculations. The combination of adjacent burnup regions can effectively reduce the memory footprint while keeping the computational accuracy.

  17. Exclusive many-particle diffusion in disordered media and correlation functions for random vertex models

    International Nuclear Information System (INIS)

    Schuetz, G.; Sandow, S.

    1993-05-01

    We consider systems of particles hopping stochastically on d-dimensional lattices with space-dependent probabilities. We map the master equation in a Fock space where the dynamics are given by a quantum Hamiltonian (continuous time) or a transfer matrix resp. (discrete time). We show that under certain conditions the time-dependent two-point density correlation function in N-particle steady state can be computed from the probability distribution of a single particle moving in the same environment. Focussing on exclusion models where the lattice site can be occupied by at most one particle we discuss as an example for such a stochastic process a generalized Heisenberg antiferromagnet where the strength of the spin-spin coupling in space-dependent. In discrete time one obtains for one dimensional systems the diagonal-to-diagonal transfer matrix of the two dimensional six vertex model with space dependent vertex weights. For a random distribution of the vertex weights one obtains a version of the random barrier model describing diffusion of particles in disordered media. We derive exact expressions for the average two-point density correlation function in the presence of weak, correlated disorder. (authors)

  18. Simulating propagation of coherent light in random media using the Fredholm type integral equation

    Science.gov (United States)

    Kraszewski, Maciej; Pluciński, Jerzy

    2017-06-01

    Studying propagation of light in random scattering materials is important for both basic and applied research. Such studies often require usage of numerical method for simulating behavior of light beams in random media. However, if such simulations require consideration of coherence properties of light, they may become a complex numerical problems. There are well established methods for simulating multiple scattering of light (e.g. Radiative Transfer Theory and Monte Carlo methods) but they do not treat coherence properties of light directly. Some variations of these methods allows to predict behavior of coherent light but only for an averaged realization of the scattering medium. This limits their application in studying many physical phenomena connected to a specific distribution of scattering particles (e.g. laser speckle). In general, numerical simulation of coherent light propagation in a specific realization of random medium is a time- and memory-consuming problem. The goal of the presented research was to develop new efficient method for solving this problem. The method, presented in our earlier works, is based on solving the Fredholm type integral equation, which describes multiple light scattering process. This equation can be discretized and solved numerically using various algorithms e.g. by direct solving the corresponding linear equations system, as well as by using iterative or Monte Carlo solvers. Here we present recent development of this method including its comparison with well-known analytical results and a finite-difference type simulations. We also present extension of the method for problems of multiple scattering of a polarized light on large spherical particles that joins presented mathematical formalism with Mie theory.

  19. A fast random walk algorithm for computing the pulsed-gradient spin-echo signal in multiscale porous media.

    Science.gov (United States)

    Grebenkov, Denis S

    2011-02-01

    A new method for computing the signal attenuation due to restricted diffusion in a linear magnetic field gradient is proposed. A fast random walk (FRW) algorithm for simulating random trajectories of diffusing spin-bearing particles is combined with gradient encoding. As random moves of a FRW are continuously adapted to local geometrical length scales, the method is efficient for simulating pulsed-gradient spin-echo experiments in hierarchical or multiscale porous media such as concrete, sandstones, sedimentary rocks and, potentially, brain or lungs. Copyright © 2010 Elsevier Inc. All rights reserved.

  20. Radiation propagation in random media: From positive to negative correlations in high-frequency fluctuations

    International Nuclear Information System (INIS)

    Davis, Anthony B.; Mineev-Weinstein, Mark B.

    2011-01-01

    We survey research on radiation propagation or ballistic particle motion through media with randomly variable material density, and we investigate the topic with an emphasis on very high spatial frequencies. Our new results are based on a specific variability model consisting of a zero-mean Gaussian scaling noise riding on a constant value that is large enough with respect to the amplitude of the noise to yield overwhelmingly non-negative density. We first generalize known results about sub-exponential transmission from regular functions, which are almost everywhere continuous, to merely 'measurable' ones, which are almost everywhere discontinuous (akin to statistically stationary noises), with positively correlated fluctuations. We then use the generalized measure-theoretic formulation to address negatively correlated stochastic media without leaving the framework of conventional (continuum-limit) transport theory. We thus resolve a controversy about recent claims that only discrete-point process approaches can accommodate negative correlations, i.e., anti-clustering of the material particles. We obtain in this case the predicted super-exponential behavior, but it is rather weak. Physically, and much like the alternative discrete-point process approach, the new model applies most naturally to scales commensurate with the inter-particle distance in the material, i.e., when the notion of particle density breaks down due to Poissonian-or maybe not-so-Poissonian-number-count fluctuations occur in the sample volume. At the same time, the noisy structure must prevail up to scales commensurate with the mean-free-path to be of practical significance. Possible applications are discussed.

  1. Anomalous dispersion in correlated porous media: a coupled continuous time random walk approach

    Science.gov (United States)

    Comolli, Alessandro; Dentz, Marco

    2017-09-01

    We study the causes of anomalous dispersion in Darcy-scale porous media characterized by spatially heterogeneous hydraulic properties. Spatial variability in hydraulic conductivity leads to spatial variability in the flow properties through Darcy's law and thus impacts on solute and particle transport. We consider purely advective transport in heterogeneity scenarios characterized by broad distributions of heterogeneity length scales and point values. Particle transport is characterized in terms of the stochastic properties of equidistantly sampled Lagrangian velocities, which are determined by the flow and conductivity statistics. The persistence length scales of flow and transport velocities are imprinted in the spatial disorder and reflect the distribution of heterogeneity length scales. Particle transitions over the velocity length scales are kinematically coupled with the transition time through velocity. We show that the average particle motion follows a coupled continuous time random walk (CTRW), which is fully parameterized by the distribution of flow velocities and the medium geometry in terms of the heterogeneity length scales. The coupled CTRW provides a systematic framework for the investigation of the origins of anomalous dispersion in terms of heterogeneity correlation and the distribution of conductivity point values. We derive analytical expressions for the asymptotic scaling of the moments of the spatial particle distribution and first arrival time distribution (FATD), and perform numerical particle tracking simulations of the coupled CTRW to capture the full average transport behavior. Broad distributions of heterogeneity point values and lengths scales may lead to very similar dispersion behaviors in terms of the spatial variance. Their mechanisms, however are very different, which manifests in the distributions of particle positions and arrival times, which plays a central role for the prediction of the fate of dissolved substances in

  2. Comparison of Media Literacy and Usual Education to Prevent Tobacco Use: A Cluster-Randomized Trial

    Science.gov (United States)

    Primack, Brian A.; Douglas, Erika L.; Land, Stephanie R.; Miller, Elizabeth; Fine, Michael J.

    2014-01-01

    Background: Media literacy programs have shown potential for reduction of adolescent tobacco use. We aimed to determine if an anti-smoking media literacy curriculum improves students' media literacy and affects factors related to adolescent smoking. Methods: We recruited 1170 9th-grade students from 64 classrooms in 3 public urban high…

  3. Certain theories of multiple scattering in random media of discrete scatterers

    International Nuclear Information System (INIS)

    Olsen, R.L.; Kharadly, M.M.Z.; Corr, D.G.

    1976-01-01

    New information is presented on the accuracy of the heuristic approximations in two important theories of multiple scattering in random media of discrete scatterers: Twersky's ''free-space'' and ''two-space scatterer'' formalisms. Two complementary approaches, based primarily on a one-dimensional model and the one-dimensional forms of the theories, are used. For scatterer distributions of low average density, the ''heuristic'' asymptotic forms for the coherent field and the incoherent intensity are compared with asymptotic forms derived from a systematic analysis of the multiple scattering processes. For distributions of higher density, both in the average number of scatterers per wavelength and in the degree of packing of finite-size scatterers, the analysis is carried out ''experimentally'' by means of a Monte Carlo computer simulation. Approximate series expressions based on the systematic approach are numerically evaluated along with the heuristic expressions. The comparison (for both forward- and back-scattered field moments) is made for the worst-case conditions of strong multiple scattering for which the theories have not previously been evaluated. Several significant conclusions are drawn which have certain practical implications: in application of the theories to describe some of the scattering phenomena which occur in the troposphere, and in the further evaluation of the theories using experiments on physical models

  4. Mass transport in fracture media: impact of the random function model assumed for fractures conductivity

    International Nuclear Information System (INIS)

    Capilla, J. E.; Rodrigo, J.; Gomez Hernandez, J. J.

    2003-01-01

    Characterizing the uncertainty of flow and mass transport models requires the definition of stochastic models to describe hydrodynamic parameters. Porosity and hydraulic conductivity (K) are two of these parameters that exhibit a high degree of spatial variability. K is usually the parameter whose variability influence to a more extended degree solutes movement. In fracture media, it is critical to properly characterize K in the most altered zones where flow and solutes migration tends to be concentrated. However, K measurements use to be scarce and sparse. This fact calls to consider stochastic models that allow quantifying the uncertainty of flow and mass transport predictions. This paper presents a convective transport problem solved in a 3D block of fractured crystalline rock. the case study is defined based on data from a real geological formation. As the scarcity of K data in fractures does not allow supporting classical multi Gaussian assumptions for K in fractures, the non multi Gaussian hypothesis has been explored, comparing mass transport results for alternative Gaussian and non-Gaussian assumptions. The latter hypothesis allows reproducing high spatial connectivity for extreme values of K. This feature is present in nature, might lead to reproduce faster solute pathways, and therefore should be modeled in order to obtain reasonably safe prediction of contaminants migration in a geological formation. The results obtained for the two alternative hypotheses show a remarkable impact of the K random function model in solutes movement. (Author) 9 refs

  5. Bounds and Estimates for Transport Coefficients of Random and Porous Media with High Contrasts

    International Nuclear Information System (INIS)

    Berryman, J G

    2004-01-01

    Bounds on transport coefficients of random polycrystals of laminates are presented, including the well-known Hashin-Shtrikman bounds and some newly formulated bounds involving two formation factors for a two-component porous medium. Some new types of self-consistent estimates are then formulated based on the observed analytical structure both of these bounds and also of earlier self-consistent estimates (of the CPA or coherent potential approximation type). A numerical study is made, assuming first that the internal structure (i.e., the laminated grain structure) is not known, and then that it is known. The purpose of this aspect of the study is to attempt to quantify the differences in the predictions of properties of a system being modeled when such organized internal structure is present in the medium but detailed spatial correlation information may or (more commonly) may not be available. Some methods of estimating formation factors from data are also presented and then applied to a high-contrast fluid-permeability data set. Hashin-Shtrikman bounds are found to be very accurate estimates for low contrast heterogeneous media. But formation factor lower bounds are superior estimates for high contrast situations. The new self-consistent estimators also tend to agree better with data than either the bounds or the CPA estimates, which themselves tend to overestimate values for high contrast conducting composites

  6. Continuous time random walk analysis of solute transport in fractured porous media

    Energy Technology Data Exchange (ETDEWEB)

    Cortis, Andrea; Cortis, Andrea; Birkholzer, Jens

    2008-06-01

    The objective of this work is to discuss solute transport phenomena in fractured porous media, where the macroscopic transport of contaminants in the highly permeable interconnected fractures can be strongly affected by solute exchange with the porous rock matrix. We are interested in a wide range of rock types, with matrix hydraulic conductivities varying from almost impermeable (e.g., granites) to somewhat permeable (e.g., porous sandstones). In the first case, molecular diffusion is the only transport process causing the transfer of contaminants between the fractures and the matrix blocks. In the second case, additional solute transfer occurs as a result of a combination of advective and dispersive transport mechanisms, with considerable impact on the macroscopic transport behavior. We start our study by conducting numerical tracer experiments employing a discrete (microscopic) representation of fractures and matrix. Using the discrete simulations as a surrogate for the 'correct' transport behavior, we then evaluate the accuracy of macroscopic (continuum) approaches in comparison with the discrete results. However, instead of using dual-continuum models, which are quite often used to account for this type of heterogeneity, we develop a macroscopic model based on the Continuous Time Random Walk (CTRW) framework, which characterizes the interaction between the fractured and porous rock domains by using a probability distribution function of residence times. A parametric study of how CTRW parameters evolve is presented, describing transport as a function of the hydraulic conductivity ratio between fractured and porous domains.

  7. Continuous-time random-walk model for anomalous diffusion in expanding media

    Science.gov (United States)

    Le Vot, F.; Abad, E.; Yuste, S. B.

    2017-09-01

    Expanding media are typical in many different fields, e.g., in biology and cosmology. In general, a medium expansion (contraction) brings about dramatic changes in the behavior of diffusive transport properties such as the set of positional moments and the Green's function. Here, we focus on the characterization of such effects when the diffusion process is described by the continuous-time random-walk (CTRW) model. As is well known, when the medium is static this model yields anomalous diffusion for a proper choice of the probability density function (pdf) for the jump length and the waiting time, but the behavior may change drastically if a medium expansion is superimposed on the intrinsic random motion of the diffusing particle. For the case where the jump length and the waiting time pdfs are long-tailed, we derive a general bifractional diffusion equation which reduces to a normal diffusion equation in the appropriate limit. We then study some particular cases of interest, including Lévy flights and subdiffusive CTRWs. In the former case, we find an analytical exact solution for the Green's function (propagator). When the expansion is sufficiently fast, the contribution of the diffusive transport becomes irrelevant at long times and the propagator tends to a stationary profile in the comoving reference frame. In contrast, for a contracting medium a competition between the spreading effect of diffusion and the concentrating effect of contraction arises. In the specific case of a subdiffusive CTRW in an exponentially contracting medium, the latter effect prevails for sufficiently long times, and all the particles are eventually localized at a single point in physical space. This "big crunch" effect, totally absent in the case of normal diffusion, stems from inefficient particle spreading due to subdiffusion. We also derive a hierarchy of differential equations for the moments of the transport process described by the subdiffusive CTRW model in an expanding medium

  8. Continuous-time random-walk model for anomalous diffusion in expanding media.

    Science.gov (United States)

    Le Vot, F; Abad, E; Yuste, S B

    2017-09-01

    Expanding media are typical in many different fields, e.g., in biology and cosmology. In general, a medium expansion (contraction) brings about dramatic changes in the behavior of diffusive transport properties such as the set of positional moments and the Green's function. Here, we focus on the characterization of such effects when the diffusion process is described by the continuous-time random-walk (CTRW) model. As is well known, when the medium is static this model yields anomalous diffusion for a proper choice of the probability density function (pdf) for the jump length and the waiting time, but the behavior may change drastically if a medium expansion is superimposed on the intrinsic random motion of the diffusing particle. For the case where the jump length and the waiting time pdfs are long-tailed, we derive a general bifractional diffusion equation which reduces to a normal diffusion equation in the appropriate limit. We then study some particular cases of interest, including Lévy flights and subdiffusive CTRWs. In the former case, we find an analytical exact solution for the Green's function (propagator). When the expansion is sufficiently fast, the contribution of the diffusive transport becomes irrelevant at long times and the propagator tends to a stationary profile in the comoving reference frame. In contrast, for a contracting medium a competition between the spreading effect of diffusion and the concentrating effect of contraction arises. In the specific case of a subdiffusive CTRW in an exponentially contracting medium, the latter effect prevails for sufficiently long times, and all the particles are eventually localized at a single point in physical space. This "big crunch" effect, totally absent in the case of normal diffusion, stems from inefficient particle spreading due to subdiffusion. We also derive a hierarchy of differential equations for the moments of the transport process described by the subdiffusive CTRW model in an expanding medium

  9. Randomized controlled trial of juzen-taiho-to in children with recurrent acute otitis media.

    Science.gov (United States)

    Ito, Makoto; Maruyama, Yumiko; Kitamura, Ken; Kobayashi, Toshimitsu; Takahashi, Haruo; Yamanaka, Noboru; Harabuchi, Yasuaki; Origasa, Hideki; Yoshizaki, Tomokazu

    2017-08-01

    Recurrent acute otitis media (AOM) in young children is rapidly increasing worldwide. Repeated antibiotic use leads to antibiotic-resistant pathogen development. Complementary and alternative medicine approaches have been suggested as a supplemental treatment option to conventional antimicrobial medicine. This randomized, parallel-group, open-label, non-herbal medicine controlled trial assessed the efficacy of a traditional Japanese herbal medicine, juzen-taiho-to (JTT) for AOM prevention in otitis-prone children. Children prone to recurrent AOM aged 6-48 months were recruited from 26 otolaryngology clinics in Japan and received conventional AOM treatment based on Japanese guidelines with or without 2 daily oral doses of JTT (0.10-0.25g/kg/day). The mean number of AOM episodes, coryza episodes, and duration of total antibiotic administration per month were compared during 3-month intervention. At least one episode of AOM was diagnosed in 71% of JTT-group and 92% of control participants during follow-up. JTT administration reduced the frequency of AOM episodes by 57% compared with children who received conventional treatment alone (0.61±0.54 vs. 1.07±0.72 AOM instances/month; P=0.005) and also significantly decreased number of coryza episodes (P=0.015) and total antibiotic administration (P=0.024). This is the first report of recurrent AOM prevention by herbal medication. JTT appears to effectively prevent recurrent AOM in children. Subsequent double-blind studies are needed to confirm the beneficial effects of JTT on recurrent AOM and upper respiratory tract infections. Copyright © 2016. Published by Elsevier B.V.

  10. Efficacy and causal mechanism of an online social media intervention to increase physical activity: Results of a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Jingwen Zhang

    2015-01-01

    Full Text Available Objective: To identify what features of social media – promotional messaging or peer networks – can increase physical activity. Method: A 13-week social media-based exercise program was conducted at a large Northeastern university in Philadelphia, PA. In a randomized controlled trial, 217 graduate students from the University were randomized to three conditions: a control condition with a basic online program for enrolling in weekly exercise classes led by instructors of the University for 13 weeks, a media condition that supplemented the basic program with weekly online promotional media messages that encourage physical activity, and a social condition that replaced the media content with an online network of four to six anonymous peers composed of other participants of the program, in which each participant was able to see their peers' progress in enrolling in classes. The primary outcome was the number of enrollments in exercise classes, and the secondary outcomes were self-reported physical activities. Data were collected in 2014. Results: Participants enrolled in 5.5 classes on average. Compared with enrollment in the control condition (mean = 4.5, promotional messages moderately increased enrollment (mean = 5.7, p = 0.08, while anonymous social networks significantly increased enrollment (mean = 6.3, p = 0.02. By the end of the program, participants in the social condition reported exercising moderately for an additional 1.6 days each week compared with the baseline, which was significantly more than an additional 0.8 days in the control condition. Conclusion: Social influence from anonymous online peers was more successful than promotional messages for improving physical activity. Clinical Trial Registration: ClinicalTrials.gov: NCT02267369.

  11. Efficacy and causal mechanism of an online social media intervention to increase physical activity: Results of a randomized controlled trial.

    Science.gov (United States)

    Zhang, Jingwen; Brackbill, Devon; Yang, Sijia; Centola, Damon

    2015-01-01

    To identify what features of social media - promotional messaging or peer networks - can increase physical activity. A 13-week social media-based exercise program was conducted at a large Northeastern university in Philadelphia, PA. In a randomized controlled trial, 217 graduate students from the University were randomized to three conditions: a control condition with a basic online program for enrolling in weekly exercise classes led by instructors of the University for 13 weeks, a media condition that supplemented the basic program with weekly online promotional media messages that encourage physical activity, and a social condition that replaced the media content with an online network of four to six anonymous peers composed of other participants of the program, in which each participant was able to see their peers' progress in enrolling in classes. The primary outcome was the number of enrollments in exercise classes, and the secondary outcomes were self-reported physical activities. Data were collected in 2014. Participants enrolled in 5.5 classes on average. Compared with enrollment in the control condition (mean = 4.5), promotional messages moderately increased enrollment (mean = 5.7, p = 0.08), while anonymous social networks significantly increased enrollment (mean = 6.3, p = 0.02). By the end of the program, participants in the social condition reported exercising moderately for an additional 1.6 days each week compared with the baseline, which was significantly more than an additional 0.8 days in the control condition. Social influence from anonymous online peers was more successful than promotional messages for improving physical activity. ClinicalTrials.gov: NCT02267369.

  12. Multilevel and quasi-Monte Carlo methods for uncertainty quantification in particle travel times through random heterogeneous porous media

    Science.gov (United States)

    Crevillén-García, D.; Power, H.

    2017-08-01

    In this study, we apply four Monte Carlo simulation methods, namely, Monte Carlo, quasi-Monte Carlo, multilevel Monte Carlo and multilevel quasi-Monte Carlo to the problem of uncertainty quantification in the estimation of the average travel time during the transport of particles through random heterogeneous porous media. We apply the four methodologies to a model problem where the only input parameter, the hydraulic conductivity, is modelled as a log-Gaussian random field by using direct Karhunen-Loéve decompositions. The random terms in such expansions represent the coefficients in the equations. Numerical calculations demonstrating the effectiveness of each of the methods are presented. A comparison of the computational cost incurred by each of the methods for three different tolerances is provided. The accuracy of the approaches is quantified via the mean square error.

  13. Multilevel and quasi-Monte Carlo methods for uncertainty quantification in particle travel times through random heterogeneous porous media.

    Science.gov (United States)

    Crevillén-García, D; Power, H

    2017-08-01

    In this study, we apply four Monte Carlo simulation methods, namely, Monte Carlo, quasi-Monte Carlo, multilevel Monte Carlo and multilevel quasi-Monte Carlo to the problem of uncertainty quantification in the estimation of the average travel time during the transport of particles through random heterogeneous porous media. We apply the four methodologies to a model problem where the only input parameter, the hydraulic conductivity, is modelled as a log-Gaussian random field by using direct Karhunen-Loéve decompositions. The random terms in such expansions represent the coefficients in the equations. Numerical calculations demonstrating the effectiveness of each of the methods are presented. A comparison of the computational cost incurred by each of the methods for three different tolerances is provided. The accuracy of the approaches is quantified via the mean square error.

  14. Restricted use of electronic media, sleep, performance, and mood in high school athletes--a randomized trial.

    Science.gov (United States)

    Harris, Anette; Gundersen, Hilde; Mørk-Andreassen, Pia; Thun, Eirunn; Bjorvatn, Bjørn; Pallesen, Ståle

    2015-12-01

    The study aims to evaluate whether 4 weeks with restricted use of electronic media after 22:00 affects sleep, athletic performance, cognitive performance, and mood in high school athletes. Eighty-five athletes were randomized to either an intervention group (n = 44), who was instructed to not use any electronic media after 22:00, or a control condition (n = 41), where they could act as they preferred in terms of media use. Primary outcomes were sleep habits measured with a sleep diary. Secondary outcomes were (a) physical performance measured with a set of standardized tests (beep test, 20-m linear sprint, chin-up test, hanging sit-ups test, counter movement jump and sit-n-reach test); (b) cognitive performance (response time and response accuracy); and (c) positive and negative affect. Differences between groups were tested with mixed between-within subject analyses of variance. Thirty-five and 40 of the athletes in the intervention and control group, respectively, completed the study. Results showed that restricted use of electronic media after 22:00 did not improve sleep habits, athletic performance, cognitive performance, or mood in a group of high school top athletes with already good sleep habits. However, these findings give us knowledge about sleep habits and performance in this population that is of importance when designing future studies. Copyright © 2015 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.

  15. Blastocyst utilization rates after continuous culture in two commercial single-step media: a prospective randomized study with sibling oocytes.

    Science.gov (United States)

    Sfontouris, Ioannis A; Kolibianakis, Efstratios M; Lainas, George T; Venetis, Christos A; Petsas, George K; Tarlatzis, Basil C; Lainas, Tryfon G

    2017-10-01

    The aim of this study is to determine whether blastocyst utilization rates are different after continuous culture in two different commercial single-step media. This is a paired randomized controlled trial with sibling oocytes conducted in infertility patients, aged ≤40 years with ≥10 oocytes retrieved assigned to blastocyst culture and transfer. Retrieved oocytes were randomly allocated to continuous culture in either Sage one-step medium (Origio) or Continuous Single Culture (CSC) medium (Irvine Scientific) without medium renewal up to day 5 post oocyte retrieval. Main outcome measure was the proportion of embryos suitable for clinical use (utilization rate). A total of 502 oocytes from 33 women were randomly allocated to continuous culture in either Sage one-step medium (n = 250) or CSC medium (n = 252). Fertilization was performed by either in vitro fertilization or intracytoplasmic sperm injection, and embryo transfers were performed on day 5. Two patients had all blastocysts frozen due to the occurrence of severe ovarian hyperstimulation syndrome. Fertilization and cleavage rates, as well as embryo quality on day 3, were similar in the two media. Blastocyst utilization rates (%, 95% CI) [55.4% (46.4-64.1) vs 54.7% (44.9-64.6), p = 0.717], blastocyst formation rates [53.6% (44.6-62.5) vs 51.9 (42.2-61.6), p = 0.755], and proportion of good quality blastocysts [36.8% (28.1-45.4) vs 36.1% (27.2-45.0), p = 0.850] were similar in Sage one-step and CSC media, respectively. Continuous culture of embryos in Sage one-step and CSC media is associated with similar blastocyst development and utilization rates. Both single-step media appear to provide adequate support during in vitro preimplantation embryo development. Whether these observations are also valid for other continuous single medium protocols remains to be determined. NCT02302638.

  16. Peculiarities of the statistics of spectrally selected fluorescence radiation in laser-pumped dye-doped random media

    Science.gov (United States)

    Yuvchenko, S. A.; Ushakova, E. V.; Pavlova, M. V.; Alonova, M. V.; Zimnyakov, D. A.

    2018-04-01

    We consider the practical realization of a new optical probe method of the random media which is defined as the reference-free path length interferometry with the intensity moments analysis. A peculiarity in the statistics of the spectrally selected fluorescence radiation in laser-pumped dye-doped random medium is discussed. Previously established correlations between the second- and the third-order moments of the intensity fluctuations in the random interference patterns, the coherence function of the probe radiation, and the path difference probability density for the interfering partial waves in the medium are confirmed. The correlations were verified using the statistical analysis of the spectrally selected fluorescence radiation emitted by a laser-pumped dye-doped random medium. Water solution of Rhodamine 6G was applied as the doping fluorescent agent for the ensembles of the densely packed silica grains, which were pumped by the 532 nm radiation of a solid state laser. The spectrum of the mean path length for a random medium was reconstructed.

  17. The Adoption of Social Media to Recruit Participants for the Cool Runnings Randomized Controlled Trial in Australia.

    Science.gov (United States)

    Burgess, Jacqueline D; Kimble, Roy M; Watt, Kerrianne; Cameron, Cate M

    2017-10-24

    Using social media to recruit specific populations for research studies is gaining popularity. Given that mothers of young children are the most active on social media, and young children are the most at risk of preventable burn injuries, social media was used to recruit mothers of young children to a burn prevention intervention. The aim of this paper was to describe the social media recruitment methods used to enroll mothers of young children to the app-based burn prevention intervention Cool Runnings. Participants were recruited via paid Facebook and Instagram advertisements to a 2-group, parallel, single-blinded, randomized controlled trial (RCT). The advertisements were targeted at women 18 years and older, living in Queensland, Australia, with at least 1 child aged 5 to 12 months at the time of recruitment. Over the 30-day recruitment period from January to February 2016, Facebook and Instagram advertisements reached 65,268 people, generating 2573 link clicks, 1161 app downloads, and 498 enrolled participants to the Cool Runnings RCT. The cost per enrolled participant was Aus $13.08. Saturdays were the most effective day of the week for advertising results. The most popular time of day for enrolments was between 5 to 11 PM. This recruitment strategy campaign resulted in a broad reach of participants from regional, rural, and remote Queensland. Participants were representative of the population in regard to age and education levels. To our knowledge, this is the first use of social media recruitment for an injury prevention campaign. This recruitment method resulted in the rapid and cost-effective recruitment of participants with social, geographic, and economic diversity that were largely representative of the population. ©Jacqueline D Burgess, Roy M Kimble, Kerrianne Watt, Cate M Cameron. Originally published in JMIR Research Protocols (http://www.researchprotocols.org), 24.10.2017.

  18. Liesegang bands versus random crystallites in Ag2Cr2O7 - Single and mixed gelled media

    Science.gov (United States)

    Ibrahim, Huria; El-Rassy, Houssam; Sultan, Rabih

    2018-02-01

    Liesegang patterns of silver dichromate (Ag2Cr2O7) are studied in two different gel media: agar and gelatin, based on the work of Lagzi and Ueyama (2009). Whereas in gelatin, standard Liesegang bands are obtained as a result of the interdiffusion of Ag+ and Cr2 O72-, random crystallites with dendritic ramifications are observed in agar. We revisit this phenomenon and demonstrate the proposed mechanism, wherein dense heterogeneous nucleation in gelatin leads to Liesegang bands, as opposed to surface nucleation in agar yielding crystallites. We use viscosity, pH measurements, and notably scanning electron microscopy (SEM) in this endeavor.

  19. Effect of H-wave polarization on laser radar detection of partially convex targets in random media.

    Science.gov (United States)

    El-Ocla, Hosam

    2010-07-01

    A study on the performance of laser radar cross section (LRCS) of conducting targets with large sizes is investigated numerically in free space and random media. The LRCS is calculated using a boundary value method with beam wave incidence and H-wave polarization. Considered are those elements that contribute to the LRCS problem including random medium strength, target configuration, and beam width. The effect of the creeping waves, stimulated by H-polarization, on the LRCS behavior is manifested. Targets taking large sizes of up to five wavelengths are sufficiently larger than the beam width and are sufficient for considering fairly complex targets. Scatterers are assumed to have analytical partially convex contours with inflection points.

  20. A Randomized Crossover Study of Web-Based Media Literacy to Prevent Smoking

    Science.gov (United States)

    Shensa, Ariel; Phelps-Tschang, Jane; Miller, Elizabeth; Primack, Brian A.

    2016-01-01

    Feasibly implemented Web-based smoking media literacy (SML) programs have been associated with improving SML skills among adolescents. However, prior evaluations have generally had weak experimental designs. We aimed to examine program efficacy using a more rigorous crossover design. Seventy-two ninth grade students completed a Web-based SML…

  1. Radiative characterization of random fibrous media with long cylindrical fibers: Comparison of single- and multi-RTE approaches

    Science.gov (United States)

    Randrianalisoa, Jaona; Haussener, Sophia; Baillis, Dominique; Lipiński, Wojciech

    2017-11-01

    Radiative heat transfer is analyzed in participating media consisting of long cylindrical fibers with a diameter in the limit of geometrical optics. The absorption and scattering coefficients and the scattering phase function of the medium are determined based on the discrete-level medium geometry and optical properties of individual fibers. The fibers are assumed to be randomly oriented and positioned inside the medium. Two approaches are employed: a volume-averaged two-intensity approach referred to as multi-RTE approach and a homogenized single-intensity approach referred to as the single-RTE approach. Both approaches require effective properties, determined using direct Monte Carlo ray tracing techniques. The macroscopic radiative transfer equations (for single intensity or two volume-averaged intensities) with the corresponding effective properties are solved using Monte Carlo techniques and allow for the determination of the radiative flux distribution as well as overall transmittance and reflectance of the medium. The results are compared against predictions by the direct Monte Carlo simulation on the exact morphology. The effects of fiber volume fraction and optical properties on the effective radiative properties and the overall slab radiative characteristics are investigated. The single-RTE approach gives accurate predictions for high porosity fibrous media (porosity about 95%). The multi-RTE approach is recommended for isotropic fibrous media with porosity in the range of 79-95%.

  2. An application of random field theory to analysis of electron trapping sites in disordered media

    International Nuclear Information System (INIS)

    Hilczer, M.; Bartczak, W.M.

    1993-01-01

    The potential energy surface in a disordered medium is considered a random field and described using the concepts of the mathematical theory of random fields. The preexisting traps for excess electrons are identified with certain regions of excursion (extreme regions) of the potential field. The theory provides an analytical method of statistical analysis of these regions. Parameters of the cavity-averaged potential field, which are provided by computer simulation of a given medium, serve as input data for the analysis. The statistics of preexisting traps are obtained for liquid methanol as a numerical example of the random field method. 26 refs., 6 figs

  3. Neutron Transport in Finite Random Media with Pure-Triplet Scattering

    International Nuclear Information System (INIS)

    Sallaha, M.; Hendi, A.A.

    2008-01-01

    The solution of the one-speed neutron transport equation in a finite slab random medium with pure-triplet anisotropic scattering is studied. The stochastic medium is assumed to consist of two randomly mixed immiscible fluids. The cross section and the scattering kernel are treated as discrete random variables, which obey the same statistics as Markovian processes and exponential chord length statistics. The medium boundaries are considered to have specular reflectivities with angular-dependent externally incident flux. The deterministic solution is obtained by using Pomraning-Eddington approximation. Numerical results are calculated for the average reflectivity and average transmissivity for different values of the single scattering albedo and varying the parameters which characterize the random medium. Compared to the results obtained by Adams et al. in case of isotropic scattering that based on the Monte Carlo technique, it can be seen that we have good comparable data

  4. Inverse random source scattering for the Helmholtz equation in inhomogeneous media

    Science.gov (United States)

    Li, Ming; Chen, Chuchu; Li, Peijun

    2018-01-01

    This paper is concerned with an inverse random source scattering problem in an inhomogeneous background medium. The wave propagation is modeled by the stochastic Helmholtz equation with the source driven by additive white noise. The goal is to reconstruct the statistical properties of the random source such as the mean and variance from the boundary measurement of the radiated random wave field at multiple frequencies. Both the direct and inverse problems are considered. We show that the direct problem has a unique mild solution by a constructive proof. For the inverse problem, we derive Fredholm integral equations, which connect the boundary measurement of the radiated wave field with the unknown source function. A regularized block Kaczmarz method is developed to solve the ill-posed integral equations. Numerical experiments are included to demonstrate the effectiveness of the proposed method.

  5. Elliptic equation for random walks. Application to transport in microporous media

    DEFF Research Database (Denmark)

    Shapiro, Alexander

    2007-01-01

    We consider a process of random walks with arbitrary residence time distribution. We show that in many cases this process may not be described by the classical (Fick) parabolic diffusion equation, but an elliptic equation. An additional term proportional to the second time derivative takes into a...

  6. Analysis and Computation of Acoustic and Elastic Wave Equations in Random Media

    KAUST Repository

    Motamed, Mohammad; Nobile, Fabio; Tempone, Raul

    2014-01-01

    ], the solution to hyperbolic problems is not in general analytic with respect to the random variables. Therefore, the rate of convergence is only algebraic. A fast spectral rate of convergence is still possible for some quantities of interest and for the wave

  7. Distance learning strategies for weight management utilizing social media: A comparison of phone conference call versus social media platform. Rationale and design for a randomized study.

    Science.gov (United States)

    Willis, Erik A; Szabo-Reed, Amanda N; Ptomey, Lauren T; Steger, Felicia L; Honas, Jeffery J; Al-Hihi, Eyad M; Lee, Robert; Vansaghi, Lisa; Washburn, Richard A; Donnelly, Joseph E

    2016-03-01

    Management of obesity in the context of the primary care physician visit is of limited efficacy in part because of limited ability to engage participants in sustained behavior change between physician visits. Therefore, healthcare systems must find methods to address obesity that reach beyond the walls of clinics and hospitals and address the issues of lifestyle modification in a cost-conscious way. The dramatic increase in technology and online social networks may present healthcare providers with innovative ways to deliver weight management programs that could have an impact on health care at the population level. A randomized study will be conducted on 70 obese adults (BMI 30.0-45.0 kg/m(2)) to determine if weight loss (6 months) is equivalent between weight management interventions utilizing behavioral strategies by either a conference call or social media approach. The primary outcome, body weight, will be assessed at baseline and 6 months. Secondary outcomes including waist circumference, energy and macronutrient intake, and physical activity will be assessed on the same schedule. In addition, a cost analysis and process evaluation will be completed. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. There’s plenty of light at the bottom: statistics of photon penetration depth in random media

    Science.gov (United States)

    Martelli, Fabrizio; Binzoni, Tiziano; Pifferi, Antonio; Spinelli, Lorenzo; Farina, Andrea; Torricelli, Alessandro

    2016-01-01

    We propose a comprehensive statistical approach describing the penetration depth of light in random media. The presented theory exploits the concept of probability density function f(z|ρ, t) for the maximum depth reached by the photons that are eventually re-emitted from the surface of the medium at distance ρ and time t. Analytical formulas for f, for the mean maximum depth 〈zmax〉 and for the mean average depth reached by the detected photons at the surface of a diffusive slab are derived within the framework of the diffusion approximation to the radiative transfer equation, both in the time domain and the continuous wave domain. Validation of the theory by means of comparisons with Monte Carlo simulations is also presented. The results are of interest for many research fields such as biomedical optics, advanced microscopy and disordered photonics. PMID:27256988

  9. Social media-delivered sexual health intervention: a cluster randomized controlled trial.

    Science.gov (United States)

    Bull, Sheana S; Levine, Deborah K; Black, Sandra R; Schmiege, Sarah J; Santelli, John

    2012-11-01

    Youth are using social media regularly and represent a group facing substantial risk for sexually transmitted infection (STI). Although there is evidence that the Internet can be used effectively in supporting healthy sexual behavior, this has not yet extended to social networking sites. To determine whether STI prevention messages delivered via Facebook are efficacious in preventing increases in sexual risk behavior at 2 and 6 months. Cluster RCT, October 2010-May 2011. Individuals (seeds) recruited in multiple settings (online, via newspaper ads and face-to-face) were asked to recruit three friends, who in turn recruited additional friends, extending three waves from the seed. Seeds and waves of friends were considered networks and exposed to either the intervention or control condition. Exposure to Just/Us, a Facebook page developed with youth input, or to control content on 18-24 News, a Facebook page with current events for 2 months. Condom use at last sex and proportion of sex acts protected by condoms. Repeated measures of nested data were used to model main effects of exposure to Just/Us and time by treatment interaction. A total of 1578 participants enrolled, with 14% Latino and 35% African-American; 75% of participants completed at least one study follow-up. Time by treatment effects were observed at 2 months for condom use (intervention 68% vs control 56%, p=0.04) and proportion of sex acts protected by condoms (intervention 63% vs control 57%, p=0.03) where intervention participation reduced the tendency for condom use to decrease over time. No effects were seen at 6 months. Social networking sites may be venues for efficacious health education interventions. More work is needed to understand what elements of social media are compelling, how network membership influences effects, and whether linking social media to clinical and social services can be beneficial. This study is registered at www.clinicaltrials.govNCT00725959. Copyright © 2012 American

  10. Effect of nasal balloon autoinflation in children with otitis media with effusion in primary care: an open randomized controlled trial

    Science.gov (United States)

    Williamson, Ian; Vennik, Jane; Harnden, Anthony; Voysey, Merryn; Perera, Rafael; Kelly, Sadie; Yao, Guiqing; Raftery, James; Mant, David; Little, Paul

    2015-01-01

    Background: Otitis media with effusion is a common problem that lacks an evidence-based nonsurgical treatment option. We assessed the clinical effectiveness of treatment with a nasal balloon device in a primary care setting. Methods: We conducted an open, pragmatic randomized controlled trial set in 43 family practices in the United Kingdom. Children aged 4–11 years with a recent history of ear symptoms and otitis media with effusion in 1 or both ears, confirmed by tympanometry, were allocated to receive either autoinflation 3 times daily for 1–3 months plus usual care or usual care alone. Clearance of middle-ear fluid at 1 and 3 months was assessed by experts masked to allocation. Results: Of 320 children enrolled, those receiving autoinflation were more likely than controls to have normal tympanograms at 1 month (47.3% [62/131] v. 35.6% [47/132]; adjusted relative risk [RR] 1.36, 95% confidence interval [CI] 0.99 to 1.88) and at 3 months (49.6% [62/125] v. 38.3% [46/120]; adjusted RR 1.37, 95% CI 1.03 to 1.83; number needed to treat = 9). Autoinflation produced greater improvements in ear-related quality of life (adjusted between-group difference in change from baseline in OMQ-14 [an ear-related measure of quality of life] score −0.42, 95% CI −0.63 to −0.22). Compliance was 89% at 1 month and 80% at 3 months. Adverse events were mild, infrequent and comparable between groups. Interpretation: Autoinflation in children aged 4–11 years with otitis media with effusion is feasible in primary care and effective both in clearing effusions and improving symptoms and ear-related child and parent quality of life. Trial registration: ISRCTN, No. 55208702. PMID:26216608

  11. Multiple Volume Scattering in Random Media and Periodic Structures with Applications in Microwave Remote Sensing and Wave Functional Materials

    Science.gov (United States)

    Tan, Shurun

    The objective of my research is two-fold: to study wave scattering phenomena in dense volumetric random media and in periodic wave functional materials. For the first part, the goal is to use the microwave remote sensing technique to monitor water resources and global climate change. Towards this goal, I study the microwave scattering behavior of snow and ice sheet. For snowpack scattering, I have extended the traditional dense media radiative transfer (DMRT) approach to include cyclical corrections that give rise to backscattering enhancements, enabling the theory to model combined active and passive observations of snowpack using the same set of physical parameters. Besides DMRT, a fully coherent approach is also developed by solving Maxwell's equations directly over the entire snowpack including a bottom half space. This revolutionary new approach produces consistent scattering and emission results, and demonstrates backscattering enhancements and coherent layer effects. The birefringence in anisotropic snow layers is also analyzed by numerically solving Maxwell's equation directly. The effects of rapid density fluctuations in polar ice sheet emission in the 0.5˜2.0 GHz spectrum are examined using both fully coherent and partially coherent layered media emission theories that agree with each other and distinct from incoherent approaches. For the second part, the goal is to develop integral equation based methods to solve wave scattering in periodic structures such as photonic crystals and metamaterials that can be used for broadband simulations. Set upon the concept of modal expansion of the periodic Green's function, we have developed the method of broadband Green's function with low wavenumber extraction (BBGFL), where a low wavenumber component is extracted and results a non-singular and fast-converging remaining part with simple wavenumber dependence. We've applied the technique to simulate band diagrams and modal solutions of periodic structures, and to

  12. Universal shift of the Brewster angle and disorder-enhanced delocalization of p waves in stratified random media.

    Science.gov (United States)

    Lee, Kwang Jin; Kim, Kihong

    2011-10-10

    We study theoretically the propagation and the Anderson localization of p-polarized electromagnetic waves incident obliquely on randomly stratified dielectric media with weak uncorrelated Gaussian disorder. Using the invariant imbedding method, we calculate the localization length and the disorder-averaged transmittance in a numerically precise manner. We find that the localization length takes an extremely large maximum value at some critical incident angle, which we call the generalized Brewster angle. The disorder-averaged transmittance also takes a maximum very close to one at the same incident angle. Even in the presence of an arbitrarily weak disorder, the generalized Brewster angle is found to be substantially different from the ordinary Brewster angle in uniform media. It is a rapidly increasing function of the average dielectric permittivity and approaches 90° when the average relative dielectric permittivity is slightly larger than two. We make a remarkable observation that the dependence of the generalized Brewster angle on the average dielectric permittivity is universal in the sense that it is independent of the strength of disorder. We also find, surprisingly, that when the average relative dielectric permittivity is less than one and the incident angle is larger than the generalized Brewster angle, both the localization length and the disorder-averaged transmittance increase substantially as the strength of disorder increases in a wide range of the disorder parameter. In other words, the Anderson localization of incident p waves can be weakened by disorder in a certain parameter regime.

  13. EFFECT OF INTRACUFF MEDIA-ALKALINISED LIGNOCAINE, SALINE, AND AIR ON ENDOTRACHEAL TUBE INDUCED EMERGENCE PHENOMENA: A RANDOMIZED CONTROLLED STUDY

    Directory of Open Access Journals (Sweden)

    Indu S

    2016-07-01

    Full Text Available CONTEXT Emergence from general anaesthesia is associated with post extubation cough, hoarseness, sore throat, and dysphagia, which may affect the smoothness of extubation. Prophylactic interventions have been studied to reduce these tracheal morbidities with varying results. AIMS To compare the efficacy of air, alkalinised lignocaine and saline in maintaining intracuff pressure and reducing postoperative cough (PEC and sore throat (POST. SETTINGS AND DESIGN A randomised controlled study conducted in a teaching hospital. METHODS AND MATERIALS 105 patients scheduled for elective surgeries were randomly allocated into groups of 35 each. The endotracheal tube (ETT cuffs were inflated with air, alkalinised lignocaine, or saline. The intracuff pressure (ICP was initially set to 25-30 cm of H2O; measured every 30 minutes and before extubation; the minimum volume for occlusion (MOV noted. The incidence PEC and POST were monitored. STATISTICAL ANALYSIS Data analysed using Chi-square test, Fisher’s exact test; Bonferroni method allowed multiple comparisons. A p value <0.05 was considered significant. RESULTS Pre-lubricated ETT cuff inflation with liquid media maintained an acceptable ICP. Saline and alkalinised lignocaine were effective in reducing PEC and POST. Alkalinised lignocaine provided smoother extubation and fared better in the early postoperative period. CONCLUSIONS Pre-lubricated ETT cuffs with liquid media reduced PEC and POST. Alkalinised lignocaine showed better profile than saline. Optimum ICP reduces tracheal morbidity.

  14. Localization of a polymer in random media: Relation to the localization of a quantum particle

    International Nuclear Information System (INIS)

    Shiferaw, Yohannes; Goldschmidt, Yadin Y.

    2001-01-01

    In this paper we consider in detail the connection between the problem of a polymer in a random medium and that of a quantum particle in a random potential. We are interested in a system of finite volume where the polymer is known to be localized inside a low minimum of the potential. We show how the end-to-end distance of a polymer that is free to move can be obtained from the density of states of the quantum particle using extreme value statistics. We give a physical interpretation to the recently discovered one-step replica-symmetry-breaking solution for the polymer [Phys. Rev. E 61, 1729 (2000)] in terms of the statistics of localized tail states. Numerical solutions of the variational equations for chains of different length are performed and compared with quenched averages computed directly by using the eigenfunctions and eigenenergies of the Schro''dinger equation for a particle in a one-dimensional random potential. The quantities investigated are the radius of gyration of a free Gaussian chain, its mean square distance from the origin and the end-to-end distance of a tethered chain. The probability distribution for the position of the chain is also investigated. The glassiness of the system is explained and is estimated from the variance of the measured quantities

  15. 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

  16. Noninferiority, randomized, controlled trial comparing embryo development using media developed for sequential or undisturbed culture in a time-lapse setup.

    Science.gov (United States)

    Hardarson, Thorir; Bungum, Mona; Conaghan, Joe; Meintjes, Marius; Chantilis, Samuel J; Molnar, Laszlo; Gunnarsson, Kristina; Wikland, Matts

    2015-12-01

    To study whether a culture medium that allows undisturbed culture supports human embryo development to the blastocyst stage equivalently to a well-established sequential media. Randomized, double-blinded sibling trial. Independent in vitro fertilization (IVF) clinics. One hundred twenty-eight patients, with 1,356 zygotes randomized into two study arms. Embryos randomly allocated into two study arms to compare embryo development on a time-lapse system using a single-step medium or sequential media. Percentage of good-quality blastocysts on day 5. Percentage of day 5 good-quality blastocysts was 21.1% (standard deviation [SD] ± 21.6%) and 22.2% (SD ± 22.1%) in the single-step time-lapse medium (G-TL) and the sequential media (G-1/G-2) groups, respectively. The mean difference (-1.2; 95% CI, -6.0; 3.6) between the two media systems for the primary end point was less than the noninferiority margin of -8%. There was a statistically significantly lower number of good-quality embryos on day 3 in the G-TL group [50.7% (SD ± 30.6%) vs. 60.8% (SD ± 30.7%)]. Four out of the 11 measured morphokinetic parameters were statistically significantly different for the two media used. The mean levels of ammonium concentration in the media at the end of the culture period was statistically significantly lower in the G-TL group as compared with the G-2 group. We have shown that a single-step culture medium supports blastocyst development equivalently to established sequential media. The ammonium concentrations were lower in the single-step media, and the measured morphokinetic parameters were modified somewhat. NCT01939626. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Addressing dental fear in children with autism spectrum disorders: a randomized controlled pilot study using electronic screen media.

    Science.gov (United States)

    Isong, Inyang A; Rao, Sowmya R; Holifield, Chloe; Iannuzzi, Dorothea; Hanson, Ellen; Ware, Janice; Nelson, Linda P

    2014-03-01

    Dental care is a significant unmet health care need for children with autism spectrum disorders (ASD). Many children with ASD do not receive dental care because of fear associated with dental procedures; oftentimes they require general anesthesia for regular dental procedures, placing them at risk of associated complications. Many children with ASD have a strong preference for visual stimuli, particularly electronic screen media. The use of visual teaching materials is a fundamental principle in designing educational programs for children with ASD. To determine if an innovative strategy using 2 types of electronic screen media was feasible and beneficial in reducing fear and uncooperative behaviors in children with ASD undergoing dental visits. We conducted a randomized controlled trial at Boston Children's Hospital dental clinic. Eighty (80) children aged 7 to 17 years with a known diagnosis of ASD and history of dental fear were enrolled in the study. Each child completed 2 preventive dental visits that were scheduled 6 months apart (visit 1 and visit 2). After visit 1, subjects were randomly assigned to 1 of 4 groups: (1) group A, control (usual care); (2) group B, treatment (video peer modeling that involved watching a DVD recording of a typically developing child undergoing a dental visit); (3) group C, treatment (video goggles that involved watching a favorite movie during the dental visit using sunglass-style video eyewear); and (4) group D, treatment (video peer modeling plus video goggles). Subjects who refused or were unable to wear the goggles watched the movie using a handheld portable DVD player. During both visits, the subject's level of anxiety and behavior were measured using the Venham Anxiety and Behavior Scales. Analyses of variance and Fisher's exact tests compared baseline characteristics across groups. Using intention to treat approach, repeated measures analyses were employed to test whether the outcomes differed significantly: (1) between

  18. Single realization stochastic FDTD for weak scattering waves in biological random media.

    Science.gov (United States)

    Tan, Tengmeng; Taflove, Allen; Backman, Vadim

    2013-02-01

    This paper introduces an iterative scheme to overcome the unresolved issues presented in S-FDTD (stochastic finite-difference time-domain) for obtaining ensemble average field values recently reported by Smith and Furse in an attempt to replace the brute force multiple-realization also known as Monte-Carlo approach with a single-realization scheme. Our formulation is particularly useful for studying light interactions with biological cells and tissues having sub-wavelength scale features. Numerical results demonstrate that such a small scale variation can be effectively modeled with a random medium problem which when simulated with the proposed S-FDTD indeed produces a very accurate result.

  19. A Peer-Led, Social Media-Delivered, Safer Sex Intervention for Chinese College Students: Randomized Controlled Trial.

    Science.gov (United States)

    Sun, Wai Han; Wong, Carlos King Ho; Wong, William Chi Wai

    2017-08-09

    The peer-led, social media-delivered intervention is an emerging method in sexual health promotion. However, no research has yet investigated its effectiveness as compared with other online channels or in an Asian population. The objective of this study is to compare a peer-led, social media-delivered, safer sex intervention with a sexual health website. Both conditions target Chinese college students in Hong Kong. A randomized controlled trial was conducted with a peer-led, safer sex Facebook group as the intervention and an existing online sexual health website as the control. The intervention materials were developed with peer input and followed the information-motivation-behavioral skills model; the intervention was moderated by peer educators. The participants filled out the online questionnaires before and after the 6-week intervention period. Outcome evaluations included safer sex attitudes, behavioral skills, and behaviors, while process evaluation focused on online experience, online-visiting frequency, and online engagement. The effect of online-visiting frequency and online engagement on outcome variables was investigated. Of 196 eligible participants-100 in the control group and 96 in the intervention group-who joined the study, 2 (1.0%) control participants joined the Facebook group and 24 of the remaining 194 participants (12.4%) were lost to follow-up. For the process evaluation, participants in the intervention group reported more satisfying online experiences (Psocial media-delivered, safer sex intervention was found to be feasible and effective in improving attitudes toward condom use and behavioral skills, but was not significantly more effective than a website. Future research may focus on the long-term effectiveness and cost-effectiveness of this popular method, as well as the potential cultural differences of using social media between different countries. Chinese Clinical Trial Registry (ChiCTR): ChiCTR-IOR-16009495; http

  20. Anomaly detection in random heterogeneous media Feynman-Kac formulae, stochastic homogenization and statistical inversion

    CERN Document Server

    Simon, Martin

    2015-01-01

    This monograph is concerned with the analysis and numerical solution of a stochastic inverse anomaly detection problem in electrical impedance tomography (EIT). Martin Simon studies the problem of detecting a parameterized anomaly in an isotropic, stationary and ergodic conductivity random field whose realizations are rapidly oscillating. For this purpose, he derives Feynman-Kac formulae to rigorously justify stochastic homogenization in the case of the underlying stochastic boundary value problem. The author combines techniques from the theory of partial differential equations and functional analysis with probabilistic ideas, paving the way to new mathematical theorems which may be fruitfully used in the treatment of the problem at hand. Moreover, the author proposes an efficient numerical method in the framework of Bayesian inversion for the practical solution of the stochastic inverse anomaly detection problem.   Contents Feynman-Kac formulae Stochastic homogenization Statistical inverse problems  Targe...

  1. Nonlinear optical spectroscopy and microscopy of model random and biological media

    Science.gov (United States)

    Guo, Yici

    Nonlinear optical (NLO) spectroscopy and microscopy applied to biomedical science are emerging as new and rapidly growing areas which offer important insight into basic phenomena. Ultrafast NLO processes provide temporal, spectral and spatial sensitivities complementary or superior to those achieved through conventional linear optical approaches. The goal of this thesis is to explore the potential of two fundamental NLO processes to produce noninvasive histological maps of biological tissues. Within the goal of the thesis, steady state intensity, polarization and angular measurements of second- and third-harmonic generations (SHG, THG) have been performed on model random scattering and animal tissue samples. The nonlinear optical effects have been evaluated using models. Conversion efficiencies of SHG and THG from animal tissue interfaces have been determined, ranging from 10-7 to 10-10. The changes in the multiharmonic signals were found to depend on both local and overall histological structures of biological samples. The spectral signatures of two photon excitation induced fluorescence from intrinsic fluorophores have been acquired and used to characterize the physical state and types of tissues. Two dimensional scanning SHG and TPF tomographic images have been obtained from in vitro animal tissues, normal and diseased human breast tissues, and resolved subsurface layers and histo-chemical distributions. By combining consecutive 2D maps, a 3D image can be produced. The structure and morphology dependence of the SH signal has been utilized to image and evaluate subsurface tumor progression depth. Second harmonic microscopy in model random and biological cells has been studied using a CCD camera to obtain direct images from subcellular structures. Finally, near infrared (NIR) NLO spectroscopy and microscopy based on SHG and TPF have demonstrated high spatial resolution, deeper penetration depth, low level photo-damaging and enhanced morphological sensitivity for

  2. Monte Carlo simulation of reflection spectra of random multilayer media strongly scattering and absorbing light

    International Nuclear Information System (INIS)

    Meglinskii, I V

    2001-01-01

    The reflection spectra of a multilayer random medium - the human skin - strongly scattering and absorbing light are numerically simulated. The propagation of light in the medium and the absorption spectra are simulated by the stochastic Monte Carlo method, which combines schemes for calculations of real photon trajectories and the statistical weight method. The model takes into account the inhomogeneous spatial distribution of blood vessels, water, and melanin, the degree of blood oxygenation, and the hematocrit index. The attenuation of the incident radiation caused by reflection and refraction at Fresnel boundaries of layers inside the medium is also considered. The simulated reflection spectra are compared with the experimental reflection spectra of the human skin. It is shown that a set of parameters that was used to describe the optical properties of skin layers and their possible variations, despite being far from complete, is nevertheless sufficient for the simulation of the reflection spectra of the human skin and their quantitative analysis. (laser applications and other topics in quantum electronics)

  3. Nonlinear and diffraction effects in propagation of N-waves in randomly inhomogeneous moving media.

    Science.gov (United States)

    Averiyanov, Mikhail; Blanc-Benon, Philippe; Cleveland, Robin O; Khokhlova, Vera

    2011-04-01

    Finite amplitude acoustic wave propagation through atmospheric turbulence is modeled using a Khokhlov-Zabolotskaya-Kuznetsov (KZK)-type equation. The equation accounts for the combined effects of nonlinearity, diffraction, absorption, and vectorial inhomogeneities of the medium. A numerical algorithm is developed which uses a shock capturing scheme to reduce the number of temporal grid points. The inhomogeneous medium is modeled using random Fourier modes technique. Propagation of N-waves through the medium produces regions of focusing and defocusing that is consistent with geometrical ray theory. However, differences up to ten wavelengths are observed in the locations of fist foci. Nonlinear effects are shown to enhance local focusing, increase the maximum peak pressure (up to 60%), and decrease the shock rise time (about 30 times). Although the peak pressure increases and the rise time decreases in focal regions, statistical analysis across the entire wavefront at a distance 120 wavelengths from the source indicates that turbulence: decreases the mean time-of-flight by 15% of a pulse duration, decreases the mean peak pressure by 6%, and increases the mean rise time by almost 100%. The peak pressure and the arrival time are primarily governed by large scale inhomogeneities, while the rise time is also sensitive to small scales.

  4. The Efficacy of a Walking Intervention Using Social Media to Increase Physical Activity: A Randomized Trial.

    Science.gov (United States)

    Rote, Aubrianne E; Klos, Lori A; Brondino, Michael J; Harley, Amy E; Swartz, Ann M

    2015-06-16

    Facebook may be a useful tool to provide a social support group to encourage increases in physical activity. This study examines the efficacy of a Facebook social support group to increase steps/day in young women. Female college freshmen (N = 63) were randomized to one of two 8-week interventions: a Facebook Social Support Group (n = 32) or a Standard Walking Intervention (n = 31). Participants in both groups received weekly step goals and tracked steps/day with a pedometer. Women in the Facebook Social Support Group were also enrolled in a Facebook group and asked to post information about their steps/day and provide feedback to one another. Women in both intervention arms significantly increased steps/day pre- to postintervention (F(8,425) = 94.43, P Facebook Social Support Group increased steps/day significantly more (F(1,138) = 11.34, P Facebook to offer a social support group to increase physical activity in young women. Women in the Facebook Social Support Group increased walking by approximately 1.5 miles/day more than women in the Standard Walking Intervention which, if maintained, could have a profound impact on their future health.

  5. A Social Media Peer Group for Mothers To Prevent Obesity from Infancy: The Grow2Gether Randomized Trial.

    Science.gov (United States)

    Fiks, Alexander G; Gruver, Rachel S; Bishop-Gilyard, Chanelle T; Shults, Justine; Virudachalam, Senbagam; Suh, Andrew W; Gerdes, Marsha; Kalra, Gurpreet K; DeRusso, Patricia A; Lieberman, Alexandra; Weng, Daniel; Elovitz, Michal A; Berkowitz, Robert I; Power, Thomas J

    2017-10-01

    Few studies have addressed obesity prevention among low-income families whose infants are at increased obesity risk. We tested a Facebook peer-group intervention for low-income mothers to foster behaviors promoting healthy infant growth. In this randomized controlled trial, 87 pregnant women (Medicaid insured, BMI ≥25 kg/m 2 ) were randomized to the Grow2Gether intervention or text message appointment reminders. Grow2Gether participants joined a private Facebook group of 9-13 women from 2 months before delivery until infant age 9 months. A psychologist facilitated groups featuring a curriculum of weekly videos addressing feeding, sleep, parenting, and maternal well-being. Feasibility was assessed using the frequency and content of participation, and acceptability using surveys. Maternal beliefs and behaviors and infant growth were assessed at birth, 2, 4, 6, and 9 months. Differences in infant growth between study arms were explored. We conducted intention-to-treat analyses using quasi-least-squares regression. Eighty-eight percent (75/85) of intervention participants (42% (36/85) food insecure, 88% (75/85) black) reported the group was helpful. Participants posted 30 times/group/week on average. At 9 months, the intervention group had significant improvement in feeding behaviors (Infant Feeding Style Questionnaire) compared to the control group (p = 0.01, effect size = 0.45). Intervention group mothers were significantly less likely to pressure infants to finish food and, at age 6 months, give cereal in the bottle. Differences were not observed for other outcomes, including maternal feeding beliefs or infant weight-for-length. A social media peer-group intervention was engaging and significantly impacted certain feeding behaviors in families with infants at high risk of obesity.

  6. Contributions to the uncertainty management in numerical modelization: wave propagation in random media and analysis of computer experiments

    International Nuclear Information System (INIS)

    Iooss, B.

    2009-01-01

    The present document constitutes my Habilitation thesis report. It recalls my scientific activity of the twelve last years, since my PhD thesis until the works completed as a research engineer at CEA Cadarache. The two main chapters of this document correspond to two different research fields both referring to the uncertainty treatment in engineering problems. The first chapter establishes a synthesis of my work on high frequency wave propagation in random medium. It more specifically relates to the study of the statistical fluctuations of acoustic wave travel-times in random and/or turbulent media. The new results mainly concern the introduction of the velocity field statistical anisotropy in the analytical expressions of the travel-time statistical moments according to those of the velocity field. This work was primarily carried by requirements in geophysics (oil exploration and seismology). The second chapter is concerned by the probabilistic techniques to study the effect of input variables uncertainties in numerical models. My main applications in this chapter relate to the nuclear engineering domain which offers a large variety of uncertainty problems to be treated. First of all, a complete synthesis is carried out on the statistical methods of sensitivity analysis and global exploration of numerical models. The construction and the use of a meta-model (inexpensive mathematical function replacing an expensive computer code) are then illustrated by my work on the Gaussian process model (kriging). Two additional topics are finally approached: the high quantile estimation of a computer code output and the analysis of stochastic computer codes. We conclude this memory with some perspectives about the numerical simulation and the use of predictive models in industry. This context is extremely positive for future researches and application developments. (author)

  7. Microstructure of two-phase random media. II. The Mayer--Montroll and Kirkwood--Salsburg hierarchies

    International Nuclear Information System (INIS)

    Torquato, S.; Stell, G.

    1983-01-01

    It is shown that the Mayer--Montroll (MM) and Kirkwood--Salsburg (KS) hierarchies of equilibrium statistical mechanics for a binary mixture under certain limits become equations for the n-point matrix probability functions S/sub n/ associated with two-phase random media. The MM representation proves to be identical to the S/sub n/ expression derived by us in a previous paper, whereas the KS representation is different and new. These results are shown to illuminate our understanding of the S/sub n/ from both a physical and quantitative point of view. In particular rigorous upper and lower bounds on the S/sub n/ are obtained for a two-phase medium formed so as to be in a state of thermal equilibrium. For such a medium consisting of impenetrable-sphere inclusions in a matrix, a new exact expression is also given for S/sub n/ in terms of a two-body probability distribution function rho/sub 2/ as well as new expressions for S/sub 3/ in terms of rho/sub 2/ and rho/sub 3/, a three-body distribution function. Physical insight into the nature of these results is given by extending some geometrical arguments originally put forth by Boltzmann

  8. The effects of ventilation tubes versus no ventilation tubes for recurrent acute otitis media or chronic otitis media with effusion in 9 to 36 month old Greenlandic children, the SIUTIT trial: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Demant, Malene Nøhr; Jensen, Ramon Gordon; Jakobsen, Janus Christian; Gluud, Christian; Homøe, Preben

    2017-01-19

    The prevalence of otitis media in Greenlandic children is one of the highest in the world. International studies have shown that otitis-prone children may benefit from tubulation of the tympanic membrane. However, it is unknown whether these results can be applied to Greenlandic children and trials on the effects of ventilation tubes in high-risk populations have, to our knowledge, never been conducted. The trial is an investigator-initiated, multicentre, randomized, blinded superiority trial of bilateral ventilation tube insertion versus treatment as usual (no tube) in Greenlandic children aged 9-36 months with chronic otitis media with effusion or recurrent acute otitis media. With randomization stratified by otitis media subtype and trial site, a type 1 error of 5% and a power of 80%, a total of 230 participants are needed to detect a decrease of two visits to a health clinic during 2 years, which is considered the minimal clinical relevant difference. The primary outcome measure will be assessed blindly by investigating medical records. Secondary outcome measures are number of episodes of acute otitis media, quality of life, number of episodes of antibiotics administration and proportion of children with tympanic membrane perforations. This trial will provide evidence-based knowledge of the effects of ventilation tubes in children with middle ear infections from the high-risk Greenlandic population. Furthermore, this trial will improve the understanding of conducting randomized clinical trials in remote areas, where management of logistical aspects is particularly challenging. ClinicalTrials.gov, NCT02490332 . Registered on 14 February 2016.

  9. Blastocyst culture using single versus sequential media in clinical IVF: a systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Sfontouris, Ioannis A; Martins, Wellington P; Nastri, Carolina O; Viana, Iara G R; Navarro, Paula A; Raine-Fenning, Nick; van der Poel, Sheryl; Rienzi, Laura; Racowsky, Catherine

    2016-10-01

    The purpose of this study was to undertake a review of the available evidence comparing the use of a single medium versus sequential media for embryo culture to the blastocyst stage in clinical IVF. We searched the Cochrane Central, PubMed, Scopus, ClinicalTrials.gov, Current Controlled Trials and WHO International Clinical Trials Registry Platform to identify randomized controlled trials comparing single versus sequential media for blastocyst culture and ongoing pregnancy rate. Included studies randomized either oocytes/zygotes or women. Eligible oocyte/zygote studies were analyzed to assess the risk difference (RD) and 95 % confidence intervals (CI) between the two media systems; eligible woman-based studies were analyzed to assess the risk ratio (RR) and 95 % CI for clinical pregnancy rate. No differences were observed between single and sequential media for either ongoing pregnancy per randomized woman (relative risk (RR) = 0.9, 95 % CI = 0.7 to 1.3, two studies including 246 women, I 2  = 0 %) or clinical pregnancy per randomized woman (RR = 1.0, 95 % CI = 0.7 to 1.4, one study including 100 women); or miscarriage per clinical pregnancy: RR = 1.3, 95 % CI = 0.4 to 4.3, two studies including 246 participants, I 2  = 0 %). Single media use was associated with an increase blastocyst formation per randomized oocyte/zygote (relative distribution (RD) = +0.06, 95 % CI = +0.01 to +0.12, ten studies including 7455 oocytes/zygotes, I 2  = 83 %) but not top/high blastocyst formation (RD = +0.05, 95 % CI = -0.01 to +0.11, five studies including 3879 oocytes/zygotes, I 2  = 93 %). The overall quality of the evidence was very low for all these four outcomes. Although using a single medium for extended culture has some practical advantages and blastocyst formation rates appear to be higher, there is insufficient evidence to recommend either sequential or single-step media as being superior for the culture of

  10. An online randomized controlled trial evaluating HIV prevention digital media interventions for men who have sex with men.

    Directory of Open Access Journals (Sweden)

    Sabina Hirshfield

    Full Text Available As HIV infection continues unabated, there is a need for effective interventions targeting at-risk men who have sex with men (MSM. Engaging MSM online where they meet sexual partners is critical for HIV prevention efforts.A randomized controlled trial (RCT conducted online among U.S. MSM recruited from several gay sexual networking websites assessed the impact of 2 HIV prevention videos and an HIV prevention webpage compared to a control condition for the study outcomes HIV testing, serostatus disclosure, and unprotected anal intercourse (UAI at 60-day follow-up. Video conditions were pooled due to reduced power from low retention (53%, n = 1,631. No participant incentives were provided.Follow-up was completed by 1,631 (53% of 3,092 eligible men. In the 60 days after the intervention, men in the pooled video condition were significantly more likely than men in the control to report full serostatus disclosure ('asked and told' with their last sexual partner (OR 1.32, 95% CI 1.01-1.74. Comparing baseline to follow-up, HIV-negative men in the pooled video (OR 0.70, 95% CI 0.54-0.91 and webpage condition (OR 0.43, 95% CI 0.25-0.72 significantly reduced UAI at follow-up. HIV-positive men in the pooled video condition significantly reduced UAI (OR 0.38, 95% CI 0.20-0.67 and serodiscordant UAI (OR 0.53, 95% CI 0.28-0.96 at follow-up.Findings from this online RCT of MSM recruited from sexual networking websites suggest that a low cost, brief digital media intervention designed to engage critical thinking can increase HIV disclosure to sexual partners and decrease sexual risk. Effective, brief HIV prevention interventions featuring digital media that are made widely available may serve as a complementary part of an overall behavioral and biomedical strategy for reducing sexual risk by addressing the specific needs and circumstances of the target population, and by changing individual knowledge, motivations, and community norms.ClinicalTrials.gov NCT

  11. Social media to supplement point-of-care ultrasound courses: the "sandwich e-learning" approach. A randomized trial.

    Science.gov (United States)

    Hempel, Dorothea; Haunhorst, Stephanie; Sinnathurai, Sivajini; Seibel, Armin; Recker, Florian; Heringer, Frank; Michels, Guido; Breitkreutz, Raoul

    2016-12-01

    Point-of-care ultrasound (POC-US) is gaining importance in almost all specialties. E-learning has been used to teach theoretical knowledge and pattern recognition. As social media are universally available, they can be utilized for educational purposes. We wanted to evaluate the utility of the sandwich e-learning approach defined as a pre-course e-learning and a post-course learning activity using Facebook after a one-day point-of-care ultrasound (POC-US) course and its effect on the retention of knowledge. A total of 62 medial students were recruited for this study and randomly assigned to one of four groups. All groups received an identical hands-on training and performed several tests during the study period. The hands-on training was performed in groups of five students per instructor with the students scanning each other. Group 1 had access to pre-course e-learning, but not to post-course e-learning. Instead of a pre-course e-learning, group 2 listened to presentations at the day of the course (classroom teaching) and had access to the post-course learning activity using Facebook. Group 3 had access to both pre- and post-course e-learning (sandwich e-learning) activities, while group 4 listened classroom presentations only (classroom teaching only). Therefore only groups 2 and 3 had access to post-course learning via Facebook by joining a secured group. Posts containing ultrasound pictures and videos were published to this group. The students were asked to "like" the posts to monitor attendance. Knowledge retention was assessed 6 weeks after the course. After 6 weeks, group 3 achieved comparable results when compared to group 2 (82.2 % + -8.2 vs. 84.3 + -8.02) (p = 0.3). Students who participated in the post-course activity were more satisfied with the overall course than students without post-course learning (5.5 vs. 5.3 on a range from 1 to 6). In this study, the sandwich e-learning approach led to equal rates of knowledge retention compared to

  12. Portable Video Media Versus Standard Verbal Communication in Surgical Information Delivery to Nurses: A Prospective Multicenter, Randomized Controlled Crossover Trial.

    Science.gov (United States)

    Kam, Jonathan; Ainsworth, Hannah; Handmer, Marcus; Louie-Johnsun, Mark; Winter, Matthew

    2016-10-01

    Continuing education of health professionals is important for delivery of quality health care. Surgical nurses are often required to understand surgical procedures. Nurses need to be aware of the expected outcomes and recognize potential complications of such procedures during their daily work. Traditional educational methods, such as conferences and tutorials or informal education at the bedside, have many drawbacks for delivery of this information in a universal, standardized, and timely manner. The rapid uptake of portable media devices makes portable video media (PVM) a potential alternative to current educational methods. To compare PVM to standard verbal communication (SVC) for surgical information delivery and educational training for nurses and evaluate its impact on knowledge acquisition and participant satisfaction. Prospective, multicenter, randomized controlled crossover trial. Two hospitals: Gosford District Hospital and Wyong Hospital. Seventy-two nursing staff (36 at each site). Information delivery via PVM--7-minute video compared to information delivered via SVC. Knowledge acquisition was measured by a 32-point questionnaire, and satisfaction with the method of education delivery was measured using the validated Client Satisfaction Questionnaire (CSQ-8). Knowledge acquisition was higher via PVM compared to SVC 25.9 (95% confidence interval [CI] 25.2-26.6) versus 24.3 (95% CI 23.5-25.1), p = .004. Participant satisfaction was higher with PVM 29.5 (95% CI 28.3-30.7) versus 26.5 (95% CI 25.1-27.9), p = .003. Following information delivery via SVC, participants had a 6% increase in knowledge scores, 24.3 (95% CI 23.5-25.1) versus 25.7 (95% CI 24.9-26.5) p = .001, and a 13% increase in satisfaction scores, 26.5 (95% CI 25.1-27.9) versus 29.9 (95% CI 28.8-31.0) p < .001, when they crossed-over to information delivery via PVM. PVM provides a novel method for providing education to nurses that improves knowledge retention and satisfaction with the

  13. Are the tolerabilities of nonionic contrast media identical? Outcome of a double-blind, randomized multicentre study with Iomeprol and lopromide

    International Nuclear Information System (INIS)

    Schmiedel, E.

    1997-01-01

    Since a larger number of nonionic contrast media is available for the radiologist, the question arises as to whether they differ in their clinical tolerability. A double-blind, randomized, two-group comparison of phase IV with Iomeprol and Iopromide was carried out at 6 hospitals involving a total of 1.200 patients with the indication for computed tomography. The contrast media doses and the flow in computed tomography of the skull, thorax, and abdomen were, depending on the centre, between 50 and 200 ml and 0.5 to 3.0 ml/s, respectively. The biostatistical evaluation of adverse events which were probably contrast medium-related produced a highly significant difference between the two contrast media in favor of Iomeprol (p=0.0005). The difference in the reactions of heat, nausea, and vomiting is of clinical relevance as such adverse events may negatively affect the examination procedure and the opacification in spiral computed tomography. (orig.) [de

  14. Nutritional Online Information for Cancer Patients: a Randomized Trial of an Internet Communication Plus Social Media Intervention.

    Science.gov (United States)

    Gnagnarella, Patrizia; Misotti, Alessandro Maria; Santoro, Luigi; Akoumianakis, Demosthenes; Del Campo, Laura; De Lorenzo, Francesco; Lombardo, Claudio; Milolidakis, Giannis; Sullivan, Richard; McVie, John Gordon

    2016-09-01

    We hypothesized that cancer patients using an Internet website would show an improvement in the knowledge about healthy eating habits, and this might be enhanced by social media interaction. A 6-month randomized intervention was set up. Eligible subjects were allocated in intervention (IG) and control groups (CG). IG had access to the website, and CG was provided with printed versions. All enrolled participants filled in Nutrition Questionnaire (NQ), Quality of Life Questionnaire (QoL) and Psychological Distress Inventory (PDI), at baseline and after 6 months. The difference between post- vs pre-questionnaires was calculated. Seventy-four subjects (CG 39; IG 35) completed the study. There was an increase in the score after the intervention in both groups for the NQ, even if not statistically significant. Dividing the IG into three categories, no (NI), low (LI) and high interactions (HI), we found a decreased score (improvement) in the CG (-0.2) and in the HI (-1.7), and an increased score (worsening) in the NI (+3.3) (p = NS) analysing the PDI. We found an increased score in the QoL both in CG and IG (adjusted LSMeans +3.5 and +2.8 points, respectively; p = NS). This study represents an example for support cancer patients. Despite the lack of significant effects, critical points and problems encountered may be of interest to researchers and organization working in the cancer setting. Intervention strategies to support patients during the care process are needed in order to attain the full potential of patient-centred care on cancer outcomes.

  15. A KDE-Based Random Walk Method for Modeling Reactive Transport With Complex Kinetics in Porous Media

    Science.gov (United States)

    Sole-Mari, Guillem; Fernà ndez-Garcia, Daniel; Rodríguez-Escales, Paula; Sanchez-Vila, Xavier

    2017-11-01

    In recent years, a large body of the literature has been devoted to study reactive transport of solutes in porous media based on pure Lagrangian formulations. Such approaches have also been extended to accommodate second-order bimolecular reactions, in which the reaction rate is proportional to the concentrations of the reactants. Rather, in some cases, chemical reactions involving two reactants follow more complicated rate laws. Some examples are (1) reaction rate laws written in terms of powers of concentrations, (2) redox reactions incorporating a limiting term (e.g., Michaelis-Menten), or (3) any reaction where the activity coefficients vary with the concentration of the reactants, just to name a few. We provide a methodology to account for complex kinetic bimolecular reactions in a fully Lagrangian framework where each particle represents a fraction of the total mass of a specific solute. The method, built as an extension to the second-order case, is based on the concept of optimal Kernel Density Estimator, which allows the concentrations to be written in terms of particle locations, hence transferring the concept of reaction rate to that of particle location distribution. By doing so, we can update the probability of particles reacting without the need to fully reconstruct the concentration maps. The performance and convergence of the method is tested for several illustrative examples that simulate the Advection-Dispersion-Reaction Equation in a 1-D homogeneous column. Finally, a 2-D application example is presented evaluating the need of fully describing non-bilinear chemical kinetics in a randomly heterogeneous porous medium.

  16. Using Culturally Sensitive Media Messages to Reduce HIV-associated Sexual Behavior in High-risk African-American Adolescents: Results from a Randomized Trial

    Science.gov (United States)

    Sznitman, Sharon; Vanable, Peter A.; Carey, Michael P.; Hennessy, Michael; Brown, Larry K.; Valois, Robert F.; Stanton, Bonita F.; Salazar, Laura F.; DiClemente, Ralph; Farber, Naomi; Romer, Daniel

    2010-01-01

    Purpose To test the long-term effects of a mass media intervention that used culturally and developmentally appropriate messages to enhance HIV-preventive beliefs and behavior of high-risk African-American adolescents. Methods Television and radio messages were delivered over three years in two cities (Syracuse, NY and Macon, GA) that were randomly selected within each of two regionally matched city pairs with the other cities (Providence, RI and Columbia, SC) serving as controls. African American adolescents ages 14 to 17 (N = 1710), recruited in the four cities over a 16-month period, completed audio computer-assisted self-interviews at recruitment and again at 3, 6, 12 and 18-months post-recruitment to assess the long-term effects of the media program. To identify the unique effects of the media intervention, youth who completed at least one follow-up and who did not test positive for any of three sexually transmitted infections at recruitment or at 6 and 12-month follow-up were retained for analysis (N=1346). Results The media intervention reached virtually all of the adolescents in the trial and produced a range of effects including improved normative condom-use negotiation expectancies and increased sex refusal self-efficacy. Most importantly, older adolescents (ages 16-17) exposed to the media program exhibited a less risky age trajectory of unprotected sex than those in the non-media cities. Conclusions Culturally tailored mass media messages delivered consistently over time have the potential to reach a large audience of high-risk adolescents, to support changes in HIV-preventive beliefs, and to reduce HIV-associated risk behaviors among older youth. PMID:21856515

  17. Ranked solutions to a class of combinatorial optimizations—with applications in mass spectrometry based peptide sequencing and a variant of directed paths in random media

    Science.gov (United States)

    Doerr, Timothy P.; Alves, Gelio; Yu, Yi-Kuo

    2005-08-01

    Typical combinatorial optimizations are NP-hard; however, for a particular class of cost functions the corresponding combinatorial optimizations can be solved in polynomial time using the transfer matrix technique or, equivalently, the dynamic programming approach. This suggests a way to efficiently find approximate solutions-find a transformation that makes the cost function as similar as possible to that of the solvable class. After keeping many high-ranking solutions using the approximate cost function, one may then re-assess these solutions with the full cost function to find the best approximate solution. Under this approach, it is important to be able to assess the quality of the solutions obtained, e.g., by finding the true ranking of the kth best approximate solution when all possible solutions are considered exhaustively. To tackle this statistical issue, we provide a systematic method starting with a scaling function generated from the finite number of high-ranking solutions followed by a convergent iterative mapping. This method, useful in a variant of the directed paths in random media problem proposed here, can also provide a statistical significance assessment for one of the most important proteomic tasks-peptide sequencing using tandem mass spectrometry data. For directed paths in random media, the scaling function depends on the particular realization of randomness; in the mass spectrometry case, the scaling function is spectrum-specific.

  18. Effects of a mixed media education intervention program on increasing knowledge, attitude, and compliance with standard precautions among nursing students: A randomized controlled trial.

    Science.gov (United States)

    Xiong, Peng; Zhang, Jun; Wang, Xiaohui; Wu, Tat Leong; Hall, Brian J

    2017-04-01

    Standard precautions (SPs) are considered fundamental protective measures to manage health care-associated infections and to reduce occupational health hazards. This study intended to assess the effectiveness of a mixed media education intervention to enhance nursing students' knowledge, attitude, and compliance with SPs. A randomized controlled trial with 84 nursing students was conducted in a teaching hospital in Hubei, China. The intervention group (n = 42) attended 3 biweekly mixed media education sessions, consisting of lectures, videos, role-play, and feedback with 15-20 minutes of individual online supervision and feedback sessions following each class. The control group learned the same material through self-directed readings. Pre- and posttest assessments of knowledge, attitudes, and compliance were assessed with the Knowledge with Standard Precautions Questionnaire, Attitude with Standard Precautions Scale, and the Compliance with Standard Precautions Scale, respectively. The Standard Bacterial Colony Index was used to assess handwashing effectiveness. At 6-week follow-up, performance on the Knowledge with Standard Precautions Questionnaire, Attitude with Standard Precautions Scale, and Compliance with Standard Precautions Scale were significantly improved in the intervention group compared with the control group (P media education intervention is effective in improving knowledge, attitude, and compliance with SPs. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  19. Efficacy of amoxicillin with and without decongestant-antihistamine for otitis media with effusion in children. Results of a double-blind, randomized trial.

    Science.gov (United States)

    Mandel, E M; Rockette, H E; Bluestone, C D; Paradise, J L; Nozza, R J

    1987-02-19

    In a randomized, double-blind, placebo-controlled trial involving 518 infants and children who had otitis media with effusion ("secretory" otitis media), we evaluated the efficacy of a two-week course of amoxicillin (40 mg per kilogram of body weight per day) with and without a four-week course of an oral decongestant-antihistamine combination. Among the 474 subjects who were evaluated at the four-week end point, the rate of resolution of middle-ear effusion was twice as high in those treated with amoxicillin, either with or without the decongestant-antihistamine, as in those who received placebo (P less than 0.001), but 69.8 percent of the amoxicillin-treated subjects still had effusion. Among both the amoxicillin-treated subjects and the placebo-treated subjects, resolution was more likely in those with initially unilateral effusion, in those who had had effusion for eight weeks or less, and in those without an upper respiratory tract infection at the four-week end point. Side effects were reported more often in subjects who received decongestant-antihistamine than in those who did not. Among the subjects without effusion at the four-week end point, recurrent effusion developed in approximately half those in both the amoxicillin and placebo groups during the subsequent three months. We conclude that in infants and children with otitis media with effusion, amoxicillin treatment increases to some extent the likelihood of resolution.

  20. Media Coverage, Journal Press Releases and Editorials Associated with Randomized and Observational Studies in High-Impact Medical Journals: A Cohort Study.

    Directory of Open Access Journals (Sweden)

    Michael T M Wang

    Full Text Available Publication of clinical research findings in prominent journals influences health beliefs and medical practice, in part by engendering news coverage. Randomized controlled trials (RCTs should be most influential in guiding clinical practice. We determined whether study design of clinical research published in high-impact journals influences media coverage.We compared the incidence and amount of media coverage of RCTs with that of observational studies published in the top 7 medical journals between 1 January 2013 and 31 March 2013. We specifically assessed media coverage of the most rigorous RCTs, those with >1000 participants that reported 'hard' outcomes. There was no difference between RCTs and observational studies in coverage by major newspapers or news agencies, or in total number of news stories generated (all P>0.63. Large RCTs reporting 'hard' outcomes did not generate more news coverage than small RCTs that reported surrogate outcomes and observational studies (all P>0.32. RCTs were more likely than observational studies to attract a journal editorial (70% vs 46%, P = 0.003, but less likely to be the subject of a journal press release (17% vs 50%, P0.99, nor were they more likely to be the subject of a journal press release (14% vs 38%, P = 0.14.The design of clinical studies whose results are published in high-impact medical journals is not associated with the likelihood or amount of ensuing news coverage.

  1. Random walk-percolation-based modeling of two-phase flow in porous media: Breakthrough time and net to gross ratio estimation

    Science.gov (United States)

    Ganjeh-Ghazvini, Mostafa; Masihi, Mohsen; Ghaedi, Mojtaba

    2014-07-01

    Fluid flow modeling in porous media has many applications in waste treatment, hydrology and petroleum engineering. In any geological model, flow behavior is controlled by multiple properties. These properties must be known in advance of common flow simulations. When uncertainties are present, deterministic modeling often produces poor results. Percolation and Random Walk (RW) methods have recently been used in flow modeling. Their stochastic basis is useful in dealing with uncertainty problems. They are also useful in finding the relationship between porous media descriptions and flow behavior. This paper employs a simple methodology based on random walk and percolation techniques. The method is applied to a well-defined model reservoir in which the breakthrough time distributions are estimated. The results of this method and the conventional simulation are then compared. The effect of the net to gross ratio on the breakthrough time distribution is studied in terms of Shannon entropy. Use of the entropy plot allows one to assign the appropriate net to gross ratio to any porous medium.

  2. A randomized, double-blind, placebo-controlled noninferiority trial of amoxicillin for clinically diagnosed acute otitis media in children 6 months to 5 years of age

    Science.gov (United States)

    Le Saux, Nicole; Gaboury, Isabelle; Baird, Marian; Klassen, Terry P.; MacCormick, Johnna; Blanchard, Colline; Pitters, Carrol; Sampson, Margaret; Moher, David

    2005-01-01

    Objectives Debate continues with respect to a “watch and wait” approach versus immediate antibiotic treatment for the initial treatment of acute otitis media. In this double-blind noninferiority trial, we compared clinical improvement rates at 14 days for children (6 months to 5 years of age) with acute otitis media who were randomly assigned to receive amoxicillin or placebo. Methods We enrolled healthy children who presented to clinics or the emergency department with a new episode of acute otitis media during the fall and winter months in Ottawa (from December 1999 to the end of March 2002). The children were randomly assigned to receive amoxicillin (60 mg/kg daily) or placebo for 10 days. Telephone follow-up was performed on each of days 1, 2 and 3 and once between day 10 and day 14. The primary outcome was clinical resolution of symptoms, defined as absence of receipt of an antimicrobial (other than the amoxicillin in the treatment group) at any time during the 14-day period. Secondary outcomes were the presence of pain and fever and the activity level in the first 3 days, recurrence rates, and the presence of middle ear effusion at 1 and 3 months. Results According to clinical scoring, 415 of the 512 children who could be evaluated had moderate disease. At 14 days 84.2% of the children receiving placebo and 92.8% of those receiving amoxicillin had clinical resolution of symptoms (absolute difference –8.6%, 95% confidence interval –14.4% to –3.0%). Children who received placebo had more pain and fever in the first 2 days. There were no statistical differences in adverse events between the 2 groups, nor were there any significant differences in recurrence rates or middle ear effusion at 1 and 3 months. Interpretation Our results did not support the hypothesis that placebo was noninferior to amoxicillin (i.e., that the 14-day cure rates among children with clinically diagnosed acute otitis media would not be substantially worse in the placebo group

  3. Media arrangement impacts cell growth in anaerobic fixed-bed reactors treating sugarcane vinasse: Structured vs. randomic biomass immobilization.

    Science.gov (United States)

    de Aquino, Samuel; Fuess, Lucas Tadeu; Pires, Eduardo Cleto

    2017-07-01

    This study reports on the application of an innovative structured-bed reactor (FVR) as an alternative to conventional packed-bed reactors (PBRs) to treat high-strength solid-rich wastewaters. Using the FVR prevents solids from accumulating within the fixed-bed, while maintaining the advantages of the biomass immobilization. The long-term operation (330days) of a FVR and a PBR applied to sugarcane vinasse under increasing organic loads (2.4-18.0kgCODm -3 day -1 ) was assessed, focusing on the impacts of the different media arrangements over the production and retention of biomass. Much higher organic matter degradation rates, as well as long-term operational stability and high conversion efficiencies (>80%) confirmed that the FVR performed better than the PBR. Despite the equivalent operating conditions, the biomass growth yield was different in both reactors, i.e., 0.095gVSSg -1 COD (FVR) and 0.066gVSSg -1 COD (PBR), indicating a clear control of the media arrangement over the biomass production in fixed-bed reactors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Exact solution to the problem of nonlinear pulse propagation through random layered media and its connection with number triangles

    International Nuclear Information System (INIS)

    Sokolow, Adam; Sen, Surajit

    2007-01-01

    An energy pulse refers to a spatially compact energy bundle. In nonlinear pulse propagation, the nonlinearity of the relevant dynamical equations could lead to pulse propagation that is nondispersive or weakly dispersive in space and time. Nonlinear pulse propagation through layered media with widely varying pulse transmission properties is not wave-like and a problem of broad interest in many areas such as optics, geophysics, atmospheric physics and ocean sciences. We study nonlinear pulse propagation through a semi-infinite sequence of layers where the layers can have arbitrary energy transmission properties. By assuming that the layers are rigid, we are able to develop exact expressions for the backscattered energy received at the surface layer. The present study is likely to be relevant in the context of energy transport through soil and similar complex media. Our study reveals a surprising connection between the problem of pulse propagation and the number patterns in the well known Pascal's and Catalan's triangles and hence provides an analytic benchmark in a challenging problem of broad interest. We close with comments on the relationship between this study and the vast body of literature on the problem of wave localization in disordered systems

  5. Scattering in discrete random media with implications to propagation through rain. Ph.D. Thesis George Washingtion Univ., Washington, D.C.

    Science.gov (United States)

    Ippolito, L. J., Jr.

    1977-01-01

    The multiple scattering effects on wave propagation through a volume of discrete scatterers were investigated. The mean field and intensity for a distribution of scatterers was developed using a discrete random media formulation, and second order series expansions for the mean field and total intensity derived for one-dimensional and three-dimensional configurations. The volume distribution results were shown to proceed directly from the one-dimensional results. The multiple scattering intensity expansion was compared to the classical single scattering intensity and the classical result was found to represent only the first three terms in the total intensity expansion. The Foldy approximation to the mean field was applied to develop the coherent intensity, and was found to exactly represent all coherent terms of the total intensity.

  6. Pure-Triplet Scattering for Radiative Transfer in Semi-infinite Random Media with Refractive-Index Dependent Boundary

    International Nuclear Information System (INIS)

    Sallah, M.; Degheidy, A.R.

    2013-01-01

    Radiative transfer problem for pure-triplet scattering, in participating half-space random medium is proposed. The medium is assumed to be random with binary Markovian mixtures (e.g. radiation transfer in astrophysical contexts where the clouds and clear sky play and two-phase medium) described by Markovian statistics. The specular reflectivity of the boundary is angular-dependent described by the Fresnel's reflection probability function. The problem is solved at first in the deterministic case, and then the solution is averaged using the formalism developed by Levermore and Pomraning, to treat particles transport problems in statistical mixtures. Some physical quantities of interest such as the reflectivity of the boundary, average radiant energy, and average net flux are computed for various values of refractive index of the boundary

  7. 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.

  8. Paediatric cardiac catheterization. Controlled, randomized study of two iodinated contrast media: iopromide 300 and ioxaglate 320 mgI/ml

    International Nuclear Information System (INIS)

    Amiel, M.; Revel, D.

    1989-01-01

    Thirty-one children were included in a prospective randomized trial comparing a new non-ionic contrast medium, iopromide 300 and the ionic low osmolar contrast medium, ioxaglate 320 mgI/ml in pediatric cardiac catheterization. There were fewer adverse effects with iopromide but no statistically significant difference was demonstrated in this small population, with a very low incidence of allergoid reactions; this tendency was confirmed by meta-analysis of the multicentre study [fr

  9. The effect of four-phasic versus three-phasic contrast media injection protocols on extravasation rate in coronary CT angiography. A randomized controlled trial

    Energy Technology Data Exchange (ETDEWEB)

    Karady, Julia; Panajotu, Alexisz; Kolossvary, Marton; Szilveszter, Balint; Jermendy, Adam L.; Bartykowszki, Andrea; Karolyi, Mihaly; Celeng, Csilla; Merkely, Bela; Maurovich-Horvat, Pal [Semmelweis University, MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Budapest (Hungary)

    2017-11-15

    Contrast media (CM) extravasation is a well-known complication of CT angiography (CTA). Our prospective randomized control study aimed to assess whether a four-phasic CM administration protocol reduces the risk of extravasation compared to the routinely used three-phasic protocol in coronary CTA. Patients referred to coronary CTA due to suspected coronary artery disease were included in the study. All patients received 400 mg/ml iomeprol CM injected with dual-syringe automated injector. Patients were randomized into a three-phasic injection-protocol group, with a CM bolus of 85 ml followed by 40 ml of 75%:25% saline/CM mixture and 30 ml saline chaser bolus; and a four-phasic injection-protocol group, with a saline pacer bolus of 10 ml injected at a lower flow rate before the three-phasic protocol. 2,445 consecutive patients were enrolled (mean age 60.6 ± 12.1 years; females 43.6%). Overall rate of extravasation was 0.9% (23/2,445): 1.4% (17/1,229) in the three-phasic group and 0.5% (6/1,216) in the four-phasic group (p = 0.034). Four-phasic CM administration protocol is easy to implement in the clinical routine at no extra cost. The extravasation rate is reduced by 65% with the application of the four-phasic protocol compared to the three-phasic protocol in coronary CTA. (orig.)

  10. Contrast media use in patients with chronic kidney disease undergoing coronary angiography: A systematic review and meta-analysis of randomized trials.

    Science.gov (United States)

    Pandya, Bhavi; Chalhoub, Jean M; Parikh, Valay; Gaddam, Sainath; Spagnola, Jonathan; El-Sayegh, Suzanne; Bogin, Marc; Kandov, Ruben; Lafferty, James; Bangalore, Sripal

    2017-02-01

    Patients with chronic kidney disease (CKD) undergoing coronary angiography (CA), adequate hydration and minimizing volume of contrast media (CM) are class 1b recommendations for preventing contrast induced nephropathy (CIN). Current data are insufficient to justify specific recommendations about isoosmolar vs. low-osmolar contrast media by the ACCF/AHA/SCAI guidelines. Randomized trials comparing IOCM to LOCM in CKD stage 3 and above patients undergoing CA, and reporting incidence of CIN (defined by a rise in creatinine of 25% from baseline) were included in the analysis. The secondary outcome of the study was the incidence of serum creatinine increase by >1mg/dl. A total of 2839 patients were included in 10 trials, in which 1430 patients received IOCM and 1393 received LOCM. When compared to LOCM, IOCM was not associated with significant benefit in preventing CIN (OR=0.72, [CI: 0.50-1.04], P=0.08, I2=59%). Subgroup analysis revealed non-significant difference in incidence of CIN based on baseline use of N-acetylcystine (NAC), diabetes status, ejection fraction, and whether percutaneous coronary intervention vs coronary angiography alone was performed. The difference between IOCM and LOCM was further attenuated when restricted to studies with larger sample size (>250 patients) (OR=0.93; [CI: 0.66-1.30]) or when compared with non-ionic LOCM (OR=0.79, [CI: 0.52-1.21]). In patients with CKD stage 3 and above undergoing coronary angiography, use of IOCM showed overall non-significant difference in incidence of CIN compared to LOCM. The difference was further attenuated when IOCM was compared with non-ionic LOCM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Predictors for contrast media-induced nephropathy and long-term survival: Prospectively assessed data from the randomized controlled Dialysis-Versus-Diuresis (DVD) trial

    Science.gov (United States)

    Hölscher, Birgit; Heitmeyer, Christine; Fobker, Manfred; Breithardt, Günter; Schaefer, Roland M; Reinecke, Holger

    2008-01-01

    BACKGROUND: Among the numerous studies concerning contrast media-induced nephropathy (CIN), there was no prospective trial that provided data on the long-term outcomes. OBJECTIVES: To prospectively assess predictors of CIN and long-term outcomes of affected patients. METHODS: Four hundred twelve consecutive patients with serum creatinine levels of 115 μmol/L to 309 μmol/L (1.3 mg/dL to 3.5 mg/dL) undergoing elective coronary angiography were included. Patients were randomly assigned to periprocedural hydration alone, hydration plus onetime hemodialysis or hydration plus N-acetylcysteine. RESULTS: Multivariate logistic regression identified the following as predictors of CIN within 72 h (equivalent to an increase in creatinine 44.2 μmol/L [0.5 mg/dL] or more) : prophylactic postprocedural hemodialysis (OR 2.86, 95% CI 1.07 to 7.69), use of angiotensin-converting enzyme inhibitors (OR 6.16, 95% CI 2.01 to 18.93), baseline glomerular filtration rate (OR 0.94, 95% CI 0.90 to 0.98) and the amount of contrast media given (OR 1.01, 95% CI 1.00 to 1.01). With regard to long-term outcome (mean follow-up 649 days), multivariate Cox regression models found elevated creatinine levels at 30 days (hazard rate ratio [HRR] 5.48, 95% CI 2.85 to 10.53), but not CIN within 72 h (HRR 1.12, 95% CI 0.63 to 2.02), to be associated with increased mortality. In addition, independent predictors for death during follow-up included left ventricular ejection fraction lower than 35% (HRR 4.01, 95% CI 2.22 to 7.26), serum phosphate (HRR 1.64, 95% CI 1.10 to 2.43) and hemoglobin (HRR 0.80, 95% CI 0.67 to 0.96). CONCLUSION: From the present prospective trial, performance of post-procedural hemodialysis, use of angiotensin-converting enzyme inhibitors, reduced baseline glomerular filtration rate and amount of contrast media were independent predictors of CIN within 72 h after catheterization. Assessing renal function after 30 days, rather than within 72 h, seemed to be more predictive for

  12. Stochastic uncertainty analysis for solute transport in randomly heterogeneous media using a Karhunen‐Loève‐based moment equation approach

    Science.gov (United States)

    Liu, Gaisheng; Lu, Zhiming; Zhang, Dongxiao

    2007-01-01

    A new approach has been developed for solving solute transport problems in randomly heterogeneous media using the Karhunen‐Loève‐based moment equation (KLME) technique proposed by Zhang and Lu (2004). The KLME approach combines the Karhunen‐Loève decomposition of the underlying random conductivity field and the perturbative and polynomial expansions of dependent variables including the hydraulic head, flow velocity, dispersion coefficient, and solute concentration. The equations obtained in this approach are sequential, and their structure is formulated in the same form as the original governing equations such that any existing simulator, such as Modular Three‐Dimensional Multispecies Transport Model for Simulation of Advection, Dispersion, and Chemical Reactions of Contaminants in Groundwater Systems (MT3DMS), can be directly applied as the solver. Through a series of two‐dimensional examples, the validity of the KLME approach is evaluated against the classical Monte Carlo simulations. Results indicate that under the flow and transport conditions examined in this work, the KLME approach provides an accurate representation of the mean concentration. For the concentration variance, the accuracy of the KLME approach is good when the conductivity variance is 0.5. As the conductivity variance increases up to 1.0, the mismatch on the concentration variance becomes large, although the mean concentration can still be accurately reproduced by the KLME approach. Our results also indicate that when the conductivity variance is relatively large, neglecting the effects of the cross terms between velocity fluctuations and local dispersivities, as done in some previous studies, can produce noticeable errors, and a rigorous treatment of the dispersion terms becomes more appropriate.

  13. The effect of four-phasic versus three-phasic contrast media injection protocols on extravasation rate in coronary CT angiography: a randomized controlled trial.

    Science.gov (United States)

    Karády, Júlia; Panajotu, Alexisz; Kolossváry, Márton; Szilveszter, Bálint; Jermendy, Ádám L; Bartykowszki, Andrea; Károlyi, Mihály; Celeng, Csilla; Merkely, Béla; Maurovich-Horvat, Pál

    2017-11-01

    Contrast media (CM) extravasation is a well-known complication of CT angiography (CTA). Our prospective randomized control study aimed to assess whether a four-phasic CM administration protocol reduces the risk of extravasation compared to the routinely used three-phasic protocol in coronary CTA. Patients referred to coronary CTA due to suspected coronary artery disease were included in the study. All patients received 400 mg/ml iomeprol CM injected with dual-syringe automated injector. Patients were randomized into a three-phasic injection-protocol group, with a CM bolus of 85 ml followed by 40 ml of 75%:25% saline/CM mixture and 30 ml saline chaser bolus; and a four-phasic injection-protocol group, with a saline pacer bolus of 10 ml injected at a lower flow rate before the three-phasic protocol. 2,445 consecutive patients were enrolled (mean age 60.6 ± 12.1 years; females 43.6%). Overall rate of extravasation was 0.9% (23/2,445): 1.4% (17/1,229) in the three-phasic group and 0.5% (6/1,216) in the four-phasic group (p = 0.034). Four-phasic CM administration protocol is easy to implement in the clinical routine at no extra cost. The extravasation rate is reduced by 65% with the application of the four-phasic protocol compared to the three-phasic protocol in coronary CTA. • Four-phasic CM injection-protocol reduces extravasation rate by 65% compared to three-phasic. • The saline pacer bolus substantially reduces the risk of CM extravasation. • The implementation of four-phasic injection-protocol is at no cost.

  14. Acute Adverse Reactions to Nonionic Iodinated Contrast Media for CT: Prospective Randomized Evaluation of the Effects of Dehydration, Oral Rehydration, and Patient Risk Factors.

    Science.gov (United States)

    Motosugi, Utaroh; Ichikawa, Tomoaki; Sano, Katsuhiro; Onishi, Hiroshi

    2016-11-01

    The objective of our study was to determine the effects of dehydration and oral rehydration on the incidence of acute adverse reactions to iodinated contrast media administered during abdominal and pelvic CT in outpatients. For our prospective randomized study performed at a single institution, adult outpatients undergoing contrast-enhanced abdominal CT were randomly divided into a rehydration group (n = 2244 patients [1379 men and 865 women]; mean age, 65.2 years; age range, 18-90 years) and a control group (n = 3715 [2112 male patients and 1603 female patients]; mean age, 65.8 years; age range, 17-96 years), which included an age- and sex-matched subgroup (adjusted control group, n = 2244). The rehydration group received an oral rehydration solution (500 mL of liquid in which osmotic pressure is adjusted to enhance gastrointestinal absorption) before abdominal and pelvic CT. Patients were also divided into subclinically dehydrated (n = 997) and hydrated (n = 4962) groups according to their answers to a questionnaire that they completed before the CT examination. The patients were interviewed about contrast-induced adverse reactions before they left the CT room, and the reactions were categorized as allergiclike or physiologic. The incidence of reactions was compared between the rehydration and control groups and between the subclinical dehydration and hydrated groups. The rehydration and control groups were compared with an unpaired t test or a chi-square or Fisher test. The overall incidence of an acute adverse reaction was 4.3% (254/5959); the acute adverse reactions included 136 allergiclike and 118 physiologic reactions. Fourteen allergiclike and nine physiologic reactions were moderate grade, and none was severe. There was no significant difference between the rehydration group and adjusted control group in the overall incidence of adverse reactions (99/2244 [4.4%] vs 100/2244 [4.5%], respectively; p = 0.9422) or between the subclinically dehydrated group

  15. The Effectiveness Of Social Media (Facebook) Compared With More Traditional Advertising Methods for Recruiting Eligible Participants To Health Research Studies: A Randomized, Controlled Clinical Trial

    OpenAIRE

    Frandsen, Mai; Thow, Megan; Ferguson, Stuart G

    2016-01-01

    Background Recruiting participants for research studies can be difficult and costly. The popularity of social media platforms (eg, Facebook) has seen corresponding growth in the number of researchers turning to social networking sites and their embedded advertising frameworks to locate eligible participants for studies. Compared with traditional recruitment strategies such as print media, social media advertising has been shown to be favorable in terms of its reach (especially with hard-to-re...

  16. Effect of a Mediterranean diet on endothelial progenitor cells and carotid intima-media thickness in type 2 diabetes: Follow-up of a randomized trial.

    Science.gov (United States)

    Maiorino, Maria Ida; Bellastella, Giuseppe; Petrizzo, Michela; Gicchino, Maurizio; Caputo, Mariangela; Giugliano, Dario; Esposito, Katherine

    2017-03-01

    Background We assessed the long-term effects of a Mediterranean diet on circulating levels of endothelial progenitor cells (EPCs) and the carotid intima-media thickness (CIMT) in patients with type 2 diabetes. Design This was a parallel, two-arm, single-centre trial. Methods Two hundred and fifteen men and women with newly diagnosed type 2 diabetes were randomized to a Mediterranean diet ( n = 108) or a low-fat diet ( n = 107). The primary outcome measures were changes in the EPC count and the CIMT of the common carotid artery after the treatment period defined as the end of trial (EOT). Results At the EOT, both the CD34 + KDR + and CD34 + KDR + CD133 + counts had increased with the Mediterranean diet compared with the low-fat diet ( p Mediterranean diet. Compared with the low-fat diet, the rate of regression in the CIMT was higher in the Mediterranean diet group (51 vs. 26%), whereas the rate of progression was lower (25 vs. 50%) ( p = 0.032 for both). Changes in the CIMT were inversely correlated with the changes in EPC levels (CD34 + KDR + , r = -0.24, p = 0.020; CD34 + KDR + CD133 + , r = -0.28, p = 0.014). At the EOT, changes in levels of HbA1c, HOMA, total cholesterol, high-density lipoprotein cholesterol and systolic blood pressure were significantly greater with the Mediterranean diet than with the low-fat diet. Conclusion Compared with a low-fat diet, a long-term trial with Mediterranean diet was associated with an increase in circulating EPCs levels and prevention of the progression of subclinical atherosclerosis in patients with newly diagnosed type 2 diabetes.

  17. Social Franchising and a Nationwide Mass Media Campaign Increased the Prevalence of Adequate Complementary Feeding in Vietnam: A Cluster-Randomized Program Evaluation.

    Science.gov (United States)

    Rawat, Rahul; Nguyen, Phuong Hong; Tran, Lan Mai; Hajeebhoy, Nemat; Nguyen, Huan Van; Baker, Jean; Frongillo, Edward A; Ruel, Marie T; Menon, Purnima

    2017-04-01

    Background: Rigorous evaluations of health system-based interventions in large-scale programs to improve complementary feeding (CF) practices are limited. Alive & Thrive applied principles of social franchising within the government health system in Vietnam to improve the quality of interpersonal counseling (IPC) for infant and young child feeding combined with a national mass media (MM) campaign and community mobilization (CM). Objective: We evaluated the impact of enhanced IPC + MM + CM (intensive) compared with standard IPC + less-intensive MM and CM (nonintensive) on CF practices and anthropometric indicators. Methods: A cluster-randomized, nonblinded evaluation design with cross-sectional surveys ( n = ∼500 children aged 6-23.9 mo and ∼1000 children aged 24-59.9 mo/group) implemented at baseline (2010) and endline (2014) was used. Difference-in-difference estimates (DDEs) of impact were calculated for intent-to-treat (ITT) analyses and modified per-protocol analyses (MPAs; mothers who attended the social franchising at least once: 62%). Results: Groups were similar at baseline. In ITT analyses, there were no significant differences between groups in changes in CF practices over time. In the MPAs, greater improvements in the intensive than in the nonintensive group were seen for minimum dietary diversity [DDE: 6.4 percentage points (pps); P franchising approach to improve IPC, delivered through the existing health care system, significantly improved CF practices, but not child growth, among mothers who used counseling services at least once. A greater impact may be achieved with strategies designed to increase service utilization. This trial was registered at clinicaltrials.gov as NCT01676623.

  18. Is gender still a predisposing factor in contrast-media associated adverse drug reactions? A systematic review and meta-analysis of randomized trials and observational studies.

    Science.gov (United States)

    Lee, Heeyoung; Song, Seungyeon; Oh, Yun-Kyoung; Kang, WonKu; Kim, Eunyoung

    2017-04-01

    To evaluate the role of gender as a risk factor for developing contrast media-associated adverse drug reactions (CM-ADRs) by comparing the incidence of CM-ADR between male and female patients according to study design, ADR type, and computed tomography (CT) examination. We systematically searched three electronic databases for eligible studies. In the studies included (n=18), we assessed effect estimates of the relative incidence of CM-ADR, analysed by experimental design, ADR type and CT examination. This was calculated by using a random effects model if clinical conditions showed heterogeneity; otherwise, a fixed effects model was used. We identified 10,776 patients administered CM. According to the designs, studies were classified into randomised controlled trials (RCTs) and observational studies. Results were as follows: risk ratio (RR)=1.07 (95% confidence interval (CI): 0.79-1.46, P=0.66) for RCTs, and RR=0.77 (95% CI: 0.58-1.04, P=0.09) for observational studies. The results of analysis according to ADR type and for undergoing CT demonstrated that the incidence of CM-ADR did not differ between males and females. We found no significant difference in the incidence of CM-ADRs between male and female patients according to study design, ADR type, or CT examination. Future studies to determine why gender has shown different roles as a risk factor between CM-ADRs and non-CM ADRs are needed. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Modeling Transport in Fractured Porous Media with the Random-Walk Particle Method: The Transient Activity Range and the Particle-Transfer Probability

    International Nuclear Information System (INIS)

    Lehua Pan; G.S. Bodvarsson

    2001-01-01

    Multiscale features of transport processes in fractured porous media make numerical modeling a difficult task, both in conceptualization and computation. Modeling the mass transfer through the fracture-matrix interface is one of the critical issues in the simulation of transport in a fractured porous medium. Because conventional dual-continuum-based numerical methods are unable to capture the transient features of the diffusion depth into the matrix (unless they assume a passive matrix medium), such methods will overestimate the transport of tracers through the fractures, especially for the cases with large fracture spacing, resulting in artificial early breakthroughs. We have developed a new method for calculating the particle-transfer probability that can capture the transient features of diffusion depth into the matrix within the framework of the dual-continuum random-walk particle method (RWPM) by introducing a new concept of activity range of a particle within the matrix. Unlike the multiple-continuum approach, the new dual-continuum RWPM does not require using additional grid blocks to represent the matrix. It does not assume a passive matrix medium and can be applied to the cases where global water flow exists in both continua. The new method has been verified against analytical solutions for transport in the fracture-matrix systems with various fracture spacing. The calculations of the breakthrough curves of radionuclides from a potential repository to the water table in Yucca Mountain demonstrate the effectiveness of the new method for simulating 3-D, mountain-scale transport in a heterogeneous, fractured porous medium under variably saturated conditions

  20. Social Franchising and a Nationwide Mass Media Campaign Increased the Prevalence of Adequate Complementary Feeding in Vietnam: A Cluster-Randomized Program Evaluation123

    Science.gov (United States)

    Rawat, Rahul; Nguyen, Phuong Hong; Tran, Lan Mai; Hajeebhoy, Nemat; Nguyen, Huan Van; Baker, Jean; Frongillo, Edward A; Ruel, Marie T; Menon, Purnima

    2017-01-01

    Background: Rigorous evaluations of health system–based interventions in large-scale programs to improve complementary feeding (CF) practices are limited. Alive & Thrive applied principles of social franchising within the government health system in Vietnam to improve the quality of interpersonal counseling (IPC) for infant and young child feeding combined with a national mass media (MM) campaign and community mobilization (CM). Objective: We evaluated the impact of enhanced IPC + MM + CM (intensive) compared with standard IPC + less-intensive MM and CM (nonintensive) on CF practices and anthropometric indicators. Methods: A cluster-randomized, nonblinded evaluation design with cross-sectional surveys (n = ∼500 children aged 6–23.9 mo and ∼1000 children aged 24–59.9 mo/group) implemented at baseline (2010) and endline (2014) was used. Difference-in-difference estimates (DDEs) of impact were calculated for intent-to-treat (ITT) analyses and modified per-protocol analyses (MPAs; mothers who attended the social franchising at least once: 62%). Results: Groups were similar at baseline. In ITT analyses, there were no significant differences between groups in changes in CF practices over time. In the MPAs, greater improvements in the intensive than in the nonintensive group were seen for minimum dietary diversity [DDE: 6.4 percentage points (pps); P franchising approach to improve IPC, delivered through the existing health care system, significantly improved CF practices, but not child growth, among mothers who used counseling services at least once. A greater impact may be achieved with strategies designed to increase service utilization. This trial was registered at clinicaltrials.gov as NCT01676623. PMID:28179488

  1. Is gender still a predisposing factor in contrast-media associated adverse drug reactions? A systematic review and meta-analysis of randomized trials and observational studies

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Heeyoung, E-mail: sselmul@hanmail.net [Evidence-Based Research Laboratory, Division of Health, Social and Clinical Pharmacotherapy, College of Pharmacy, Chung-Ang University, Seoul (Korea, Republic of); Song, Seungyeon, E-mail: tmddus0121@hotmail.com [Evidence-Based Research Laboratory, Division of Health, Social and Clinical Pharmacotherapy, College of Pharmacy, Chung-Ang University, Seoul (Korea, Republic of); Oh, Yun-Kyoung, E-mail: rky221@hanmail.net [Evidence-Based Research Laboratory, Division of Health, Social and Clinical Pharmacotherapy, College of Pharmacy, Chung-Ang University, Seoul (Korea, Republic of); Department of Pharmacy, Konkuk University Medical Center, Seoul (Korea, Republic of); Kang, WonKu, E-mail: wkang@cau.ac.kr [College of Pharmacy, Chung-Ang University, Seoul (Korea, Republic of); Kim, Eunyoung, E-mail: eykimjcb777@cau.ac.kr [Evidence-Based Research Laboratory, Division of Health, Social and Clinical Pharmacotherapy, College of Pharmacy, Chung-Ang University, Seoul (Korea, Republic of); College of Pharmacy, Chung-Ang University, Seoul (Korea, Republic of)

    2017-04-15

    Highlights: • Analyzing RCTs and observational studies shows similar CM-ADR developments between genders. • Gender factor is not related to developing CIN and non-renal CM-ADR. • Gender is not a predisposing factor of CM-ADRs under current evidences. - Abstract: Objective: To evaluate the role of gender as a risk factor for developing contrast media-associated adverse drug reactions (CM-ADRs) by comparing the incidence of CM-ADR between male and female patients according to study design, ADR type, and computed tomography (CT) examination. Material and methods: We systematically searched three electronic databases for eligible studies. In the studies included (n = 18), we assessed effect estimates of the relative incidence of CM-ADR, analysed by experimental design, ADR type and CT examination. This was calculated by using a random effects model if clinical conditions showed heterogeneity; otherwise, a fixed effects model was used. Results: We identified 10,776 patients administered CM. According to the designs, studies were classified into randomised controlled trials (RCTs) and observational studies. Results were as follows: risk ratio (RR) = 1.07 (95% confidence interval (CI): 0.79–1.46, P = 0.66) for RCTs, and RR = 0.77 (95% CI: 0.58–1.04, P = 0.09) for observational studies. The results of analysis according to ADR type and for undergoing CT demonstrated that the incidence of CM-ADR did not differ between males and females. Conclusions: We found no significant difference in the incidence of CM-ADRs between male and female patients according to study design, ADR type, or CT examination. Future studies to determine why gender has shown different roles as a risk factor between CM-ADRs and non-CM ADRs are needed.

  2. Is gender still a predisposing factor in contrast-media associated adverse drug reactions? A systematic review and meta-analysis of randomized trials and observational studies

    International Nuclear Information System (INIS)

    Lee, Heeyoung; Song, Seungyeon; Oh, Yun-Kyoung; Kang, WonKu; Kim, Eunyoung

    2017-01-01

    Highlights: • Analyzing RCTs and observational studies shows similar CM-ADR developments between genders. • Gender factor is not related to developing CIN and non-renal CM-ADR. • Gender is not a predisposing factor of CM-ADRs under current evidences. - Abstract: Objective: To evaluate the role of gender as a risk factor for developing contrast media-associated adverse drug reactions (CM-ADRs) by comparing the incidence of CM-ADR between male and female patients according to study design, ADR type, and computed tomography (CT) examination. Material and methods: We systematically searched three electronic databases for eligible studies. In the studies included (n = 18), we assessed effect estimates of the relative incidence of CM-ADR, analysed by experimental design, ADR type and CT examination. This was calculated by using a random effects model if clinical conditions showed heterogeneity; otherwise, a fixed effects model was used. Results: We identified 10,776 patients administered CM. According to the designs, studies were classified into randomised controlled trials (RCTs) and observational studies. Results were as follows: risk ratio (RR) = 1.07 (95% confidence interval (CI): 0.79–1.46, P = 0.66) for RCTs, and RR = 0.77 (95% CI: 0.58–1.04, P = 0.09) for observational studies. The results of analysis according to ADR type and for undergoing CT demonstrated that the incidence of CM-ADR did not differ between males and females. Conclusions: We found no significant difference in the incidence of CM-ADRs between male and female patients according to study design, ADR type, or CT examination. Future studies to determine why gender has shown different roles as a risk factor between CM-ADRs and non-CM ADRs are needed.

  3. Psychophysiological effects of a web-based stress management system: a prospective, randomized controlled intervention study of IT and media workers [ISRCTN54254861].

    Science.gov (United States)

    Hasson, Dan; Anderberg, Ulla Maria; Theorell, Töres; Arnetz, Bengt B

    2005-07-25

    The aim of the present study was to assess possible effects on mental and physical well-being and stress-related biological markers of a web-based health promotion tool. A randomized, prospectively controlled study was conducted with before and after measurements, involving 303 employees (187 men and 116 women, age 23-64) from four information technology and two media companies. Half of the participants were offered web-based health promotion and stress management training (intervention) lasting for six months. All other participants constituted the reference group. Different biological markers were measured to detect possible physiological changes. After six months the intervention group had improved statistically significantly compared to the reference group on ratings of ability to manage stress, sleep quality, mental energy, concentration ability and social support. The anabolic hormone dehydroepiandosterone sulphate (DHEA-S) decreased significantly in the reference group as compared to unchanged levels in the intervention group. Neuropeptide Y (NPY) increased significantly in the intervention group compared to the reference group. Chromogranin A (CgA) decreased significantly in the intervention group as compared to the reference group. Tumour necrosis factor alpha (TNFalpha) decreased significantly in the reference group compared to the intervention group. Logistic regression analysis revealed that group (intervention vs. reference) remained a significant factor in five out of nine predictive models. The results indicate that an automatic web-based system might have short-term beneficial physiological and psychological effects and thus might be an opportunity in counteracting some clinically relevant and common stress and health issues of today.

  4. Psychophysiological effects of a web-based stress management system: A prospective, randomized controlled intervention study of IT and media workers [ISRCTN54254861

    Directory of Open Access Journals (Sweden)

    Theorell Töres

    2005-07-01

    Full Text Available Abstract Background The aim of the present study was to assess possible effects on mental and physical well-being and stress-related biological markers of a web-based health promotion tool. Methods A randomized, prospectively controlled study was conducted with before and after measurements, involving 303 employees (187 men and 116 women, age 23–64 from four information technology and two media companies. Half of the participants were offered web-based health promotion and stress management training (intervention lasting for six months. All other participants constituted the reference group. Different biological markers were measured to detect possible physiological changes. Results After six months the intervention group had improved statistically significantly compared to the reference group on ratings of ability to manage stress, sleep quality, mental energy, concentration ability and social support. The anabolic hormone dehydroepiandosterone sulphate (DHEA-S decreased significantly in the reference group as compared to unchanged levels in the intervention group. Neuropeptide Y (NPY increased significantly in the intervention group compared to the reference group. Chromogranin A (CgA decreased significantly in the intervention group as compared to the reference group. Tumour necrosis factor α (TNFα decreased significantly in the reference group compared to the intervention group. Logistic regression analysis revealed that group (intervention vs. reference remained a significant factor in five out of nine predictive models. Conclusion The results indicate that an automatic web-based system might have short-term beneficial physiological and psychological effects and thus might be an opportunity in counteracting some clinically relevant and common stress and health issues of today.

  5. Analisis Kebutuhan Terhadap Program Multi Media Interaktif Sebagai Media Pembelajaran

    OpenAIRE

    waldopo, Waldopo

    2011-01-01

    Multimedia interactive is on instructional media that combines elements of sound, visual and text, and can interact with the users. The aim of this study is to obtain information about the needs of interactive multimedia as instructional media. If needed, what kind of subjects that need to be supported by multi-media and type of format that presented. The population are students, teachers and senior secondary school principals. Sample was taken randomly. From the results of randomization assi...

  6. SOCIAL MEDIA

    Science.gov (United States)

    RESPONSIBILITY CENTCOM COALITION MEDIA SOCIAL MEDIA NEWS ARTICLES PRESS RELEASES IMAGERY VIDEOS TRANSCRIPTS VISITORS AND PERSONNEL FAMILY CENTER FAMILY READINESS CENTCOM WEBMAIL SOCIAL MEDIA SECURITY ACCOUNTABILITY HomeMEDIASOCIAL MEDIA Social Media CENTCOM'S ENGLISH SOCIAL MEDIA ACCOUNTS There are many U.S. military commands

  7. Transport in Stochastic Media

    International Nuclear Information System (INIS)

    Haran, O.; Shvarts, D.; Thieberger, R.

    1998-01-01

    Classical transport of neutral particles in a binary, scattering, stochastic media is discussed. It is assumed that the cross-sections of the constituent materials and their volume fractions are known. The inner structure of the media is stochastic, but there exist a statistical knowledge about the lump sizes, shapes and arrangement. The transmission through the composite media depends on the specific heterogeneous realization of the media. The current research focuses on the averaged transmission through an ensemble of realizations, frm which an effective cross-section for the media can be derived. The problem of one dimensional transport in stochastic media has been studied extensively [1]. In the one dimensional description of the problem, particles are transported along a line populated with alternating material segments of random lengths. The current work discusses transport in two-dimensional stochastic media. The phenomenon that is unique to the multi-dimensional description of the problem is obstacle bypassing. Obstacle bypassing tends to reduce the opacity of the media, thereby reducing its effective cross-section. The importance of this phenomenon depends on the manner in which the obstacles are arranged in the media. Results of transport simulations in multi-dimensional stochastic media are presented. Effective cross-sections derived from the simulations are compared against those obtained for the one-dimensional problem, and against those obtained from effective multi-dimensional models, which are partially based on a Markovian assumption

  8. 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)

  9. The Effectiveness Of Social Media (Facebook) Compared With More Traditional Advertising Methods for Recruiting Eligible Participants To Health Research Studies: A Randomized, Controlled Clinical Trial

    Science.gov (United States)

    Thow, Megan; Ferguson, Stuart G

    2016-01-01

    Background Recruiting participants for research studies can be difficult and costly. The popularity of social media platforms (eg, Facebook) has seen corresponding growth in the number of researchers turning to social networking sites and their embedded advertising frameworks to locate eligible participants for studies. Compared with traditional recruitment strategies such as print media, social media advertising has been shown to be favorable in terms of its reach (especially with hard-to-reach populations), cost effectiveness, and usability. However, to date, no studies have examined how participants recruited via social media progress through a study compared with those recruited using more traditional recruitment strategies. Objectives (1) Examine whether visiting the study website prior to being contacted by researchers creates self-screened participants who are more likely to progress through all study phases (eligible, enrolled, completed); (2) compare conversion percentages and cost effectiveness of each recruitment method at each study phase; and, (3) compare demographic and smoking characteristics of participants recruited through each strategy to determine if they attract similar samples. Methods Participants recruited to a smoking cessation clinical trial were grouped by how they had become aware of the study: via social media (Facebook) or traditional media (eg, newspaper, flyers, radio, word of mouth). Groups were compared based on throughput data (conversion percentages and cost) as well as demographic and smoking characteristics. Results Visiting the study website did not result in individuals who were more likely to be eligible for (P=.24), enroll in (P=.20), or complete (P=.25) the study. While using social media was more cost effective than traditional methods when we examined earlier endpoints of the recruitment process (cost to obtain a screened respondent: AUD $22.73 vs $29.35; cost to obtain an eligible respondent: $37.56 vs $44.77), it was

  10. The Effectiveness Of Social Media (Facebook) Compared With More Traditional Advertising Methods for Recruiting Eligible Participants To Health Research Studies: A Randomized, Controlled Clinical Trial.

    Science.gov (United States)

    Frandsen, Mai; Thow, Megan; Ferguson, Stuart G

    2016-08-10

    Recruiting participants for research studies can be difficult and costly. The popularity of social media platforms (eg, Facebook) has seen corresponding growth in the number of researchers turning to social networking sites and their embedded advertising frameworks to locate eligible participants for studies. Compared with traditional recruitment strategies such as print media, social media advertising has been shown to be favorable in terms of its reach (especially with hard-to-reach populations), cost effectiveness, and usability. However, to date, no studies have examined how participants recruited via social media progress through a study compared with those recruited using more traditional recruitment strategies. (1) Examine whether visiting the study website prior to being contacted by researchers creates self-screened participants who are more likely to progress through all study phases (eligible, enrolled, completed); (2) compare conversion percentages and cost effectiveness of each recruitment method at each study phase; and, (3) compare demographic and smoking characteristics of participants recruited through each strategy to determine if they attract similar samples. Participants recruited to a smoking cessation clinical trial were grouped by how they had become aware of the study: via social media (Facebook) or traditional media (eg, newspaper, flyers, radio, word of mouth). Groups were compared based on throughput data (conversion percentages and cost) as well as demographic and smoking characteristics. Visiting the study website did not result in individuals who were more likely to be eligible for (P=.24), enroll in (P=.20), or complete (P=.25) the study. While using social media was more cost effective than traditional methods when we examined earlier endpoints of the recruitment process (cost to obtain a screened respondent: AUD $22.73 vs $29.35; cost to obtain an eligible respondent: $37.56 vs $44.77), it was less cost effective in later endpoints

  11. Media education.

    Science.gov (United States)

    Strasburger, Victor C

    2010-11-01

    The American Academy of Pediatrics recognizes that exposure to mass media (eg, television, movies, video and computer games, the Internet, music lyrics and videos, newspapers, magazines, books, advertising) presents health risks for children and adolescents but can provide benefits as well. Media education has the potential to reduce the harmful effects of media and accentuate the positive effects. By understanding and supporting media education, pediatricians can play an important role in reducing harmful effects of media on children and adolescents.

  12. Media Komunitas dan Media Literacy

    Directory of Open Access Journals (Sweden)

    Pawito .

    2013-12-01

    Full Text Available Abstract:This essay deals with community media in relation to media literacy. After a short discussion on a number of community media characters is made the essay goes further with somewhat detail theoretical presumptions of the roles of media community with respect primarily to the development as Amartya Sen mentioned about. The author suggests that community media may play some significant roles in the development including (a disseminating information (from varieties of perspective, (b facilitating public discussion, (c helping to reach solutions of problems, (d encouraging participations, and (e encouraging the development of media literacy. Regarding the last point the author remarks that media community may have a dual-roles i.e facilitating community’s member in media participation and facilitating community’s member in media education.

  13. Mass Media for Smoking Cessation in Adolescents

    Science.gov (United States)

    Solomon, Laura J.; Bunn, Janice Y.; Flynn, Brian S.; Pirie, Phyllis L.; Worden, John K.; Ashikaga, Takamaru

    2009-01-01

    Theory-driven, mass media interventions prevent smoking among youth. This study examined effects of a media campaign on adolescent smoking cessation. Four matched pairs of media markets in four states were randomized to receive or not receive a 3-year television/radio campaign aimed at adolescent smoking cessation based on social cognitive theory.…

  14. Locative media

    CERN Document Server

    Wilken, Rowan

    2014-01-01

    Not only is locative media one of the fastest growing areas in digital technology, but questions of location and location-awareness are increasingly central to our contemporary engagements with online and mobile media, and indeed media and culture generally. This volume is a comprehensive account of the various location-based technologies, services, applications, and cultures, as media, with an aim to identify, inventory, explore, and critique their cultural, economic, political, social, and policy dimensions internationally. In particular, the collection is organized around the perception that the growth of locative media gives rise to a number of crucial questions concerning the areas of culture, economy, and policy.

  15. Media Entrepreneurship

    DEFF Research Database (Denmark)

    Khajeheian, Datis

    2017-01-01

    Media Entrepreneurship has been an ambiguous, unclear and controversial concept and despite of growing academic efforts in the last decade, it is still a poorly defined subject. This paper is an effort to fill this gap by providing a comprehensive definition of media entrepreneurship. Firstly......, a literature review conducted and entrepreneurship, media, opportunity and innovation as building blocks of media entrepreneurship explained. Then by using of a mixed of bibliographic method and a Delphi method with multi-stage analysis process, a consensual definition of media entrepreneurship proposed...... entrepreneurship....

  16. Media Framing

    DEFF Research Database (Denmark)

    Pedersen, Rasmus T.

    2017-01-01

    The concept of media framing refers to the way in which the news media organize and provide meaning to a news story by emphasizing some parts of reality and disregarding other parts. These patterns of emphasis and exclusion in news coverage create frames that can have considerable effects on news...... consumers’ perceptions and attitudes regarding the given issue or event. This entry briefly elaborates on the concept of media framing, presents key types of media frames, and introduces the research on media framing effects....

  17. Sensitive Media

    Directory of Open Access Journals (Sweden)

    Malinowska Anna

    2017-12-01

    Full Text Available The paper engages with what we refer to as “sensitive media,” a concept associated with developments in the overall media environment, our relationships with media devices, and the quality of the media themselves. Those developments point to the increasing emotionality of the media world and its infrastructures. Mapping the trajectories of technological development and impact that the newer media exert on human condition, our analysis touches upon various forms of emergent affect, emotion, and feeling in order to trace the histories and motivations of the sensitization of “the media things” as well as the redefinition of our affective and emotional experiences through technologies that themselves “feel.”

  18. Media Ecology

    Directory of Open Access Journals (Sweden)

    Marina Ašković

    2015-05-01

    Full Text Available Does the trend in which electronic media are gradually becoming extension of human body have to move towards full enslavement of a human and his personality, or the same human will unpredictably, with the aid of his personal media literacy, exit the whirls of media and technological censorships? Personality crisis is closely related to the crisis of language no matter how contradicted to global ideology of transnational transhumanism it may seem. Considering the fact that recent media presentations of the world are based on commercialization of environmentalism, philosophical and aesthetic thought appears as an important subject of ecology. As media mediates, the scenery of civilized living increasingly becomes more appealing even though it derives from commercial and political background. Consequently, the future of humanity depends by large on the philosophy of media. Media have to truly ecologise returning the humanum to its essence making it into the extension of the natural world.

  19. A fast random walk algorithm for computing diffusion-weighted NMR signals in multi-scale porous media: A feasibility study for a Menger sponge

    International Nuclear Information System (INIS)

    Grebenkov, Denis S.; Nguyen, Hang T.; Li, Jing-Rebecca

    2013-01-01

    A fast random walk (FRW) algorithm is adapted to compute diffusion-weighted NMR signals in a Menger sponge which is formed by multiple channels of broadly distributed sizes and often considered as a model for soils and porous materials. The self-similar structure of a Menger sponge allows for rapid simulations that were not feasible by other numerical techniques. The role of multiple length scales on diffusion-weighted NMR signals is investigated. (authors)

  20. Early detection and intervention using neutrophil gelatinase-associated lipocalin (NGAL) may improve renal outcome of acute contrast media induced nephropathy: a randomized controlled trial in patients undergoing intra-arterial angiography (ANTI-CIN Study).

    Science.gov (United States)

    Schilcher, Gernot; Ribitsch, Werner; Otto, Ronald; Portugaller, Rupert H; Quehenberger, Franz; Truschnig-Wilders, Martini; Zweiker, Robert; Stiegler, Philipp; Brodmann, Marianne; Weinhandl, Klemens; Horina, Joerg H

    2011-08-17

    Patients with pre-existing impaired renal function are prone to develop acute contrast media induced nephropathy (CIN). Neutrophil gelatinase-associated lipocalin (NGAL), a new biomarker predictive for acute kidney injury (AKI), has been shown to be useful for earlier diagnosis of CIN; however, urinary NGAL values may be markedly increased in chronic renal failure at baseline. Results from those studies suggested that urinary NGAL values may not be helpful for the clinician. An intravenous volume load is a widely accepted prophylactic measure and possibly a reasonable intervention to prevent deterioration of renal function. The aim of our study is to evaluate NGAL as an early predictor of CIN and to investigate the clinical benefit of early post-procedural i.v. hydration. The study will follow a prospective, open-label, randomized controlled design. Patients requiring intra-arterial contrast media (CM) application will be included and receive standardized, weight-based, intravenous hydration before investigation. Subjects with markedly increased urinary NGAL values after CM application will be randomized into one of two study groups. Group A will receive 3-4 ml/kg BW/h 0.9% saline intravenously for 6 hours. Group B will undergo only standard treatment consisting of unrestricted oral fluid intake. The primary outcome measure will be CIN defined by an increase greater than 25% of baseline serum creatinine. Secondary outcomes will include urinary NGAL values, cystatin C values, contrast media associated changes in cardiac parameters such as NT-pro-BNP/troponin T, changes in urinary cytology, need for renal replacement treatment, length of stay in hospital and death.We assume that 20% of the included patients will show a definite rise in urinary NGAL. Prospective statistical power calculations indicate that the study will have 80% statistical power to detect a clinically significant decrease of CIN of 40% in the treatment arm if 1200 patients are recruited into the

  1. Media Flow

    DEFF Research Database (Denmark)

    Kabel, Lars

    2016-01-01

    News and other kinds of journalistic stories, 16-17 hours a day, all year round, on all platforms, also the moderated social media. The key research thesis behind this article is that the continuous and speedy stream of news stories and media content now is becoming the centre of the production...... processes and the value creation in converged multimedia newsrooms. The article identify new methods and discuss editorial challenges in handling media flow....

  2. Effect of social media in improving knowledge among patients having fixed appliance orthodontic treatment: A single-center randomized controlled trial.

    Science.gov (United States)

    Al-Silwadi, Fadi M; Gill, Daljit S; Petrie, Aviva; Cunningham, Susan J

    2015-08-01

    Research has shown that orthodontic patients are more likely to retain information presented in an audiovisual format. However, there has been little research on the effectiveness of audiovisual information provided through different routes such as the Internet. This parallel-group randomized controlled trial assessed whether provision of audiovisual information on the YouTube (Google, San Bruno, Calif) Web site to orthodontic patients undergoing fixed appliance treatment results in improved patient knowledge when compared with conventional methods of information provision. The effects of sex and ethnicity were also investigated. Participants were recruited from the Department of Orthodontics of the Eastman Dental Hospital, University College London Hospitals NHS Foundation Trust, United Kingdom. The patients were 13 years of age and over, with no history of orthodontic treatment, and patient and parental (where appropriate) consent were obtained. The participants were randomized into control (n = 34) and intervention (n = 33) groups using a random number table; there was stratification based on age group, with permuted blocks of 10 patients. Both groups were given routine verbal and written patient information related to fixed appliances, and the participants in the intervention group were sent 3 e-mails over 6 weeks requesting that they view a 6-minute YouTube video containing similar information but in audiovisual format. Patient knowledge was measured using identical questionnaires answered on the day of recruitment (baseline) and again 6 to 8 weeks later. The researchers were unaware of group allocations when enrolling patients and scoring questionnaires. Sixty participants (89.55%) completed the study. Those who completed the trial in the intervention group (n = 30) demonstrated significantly greater improvements in knowledge than did those in the control group (n = 30), scoring, on average, almost 1 point more (95% CI for the difference, 0.305-1.602; P = 0

  3. Scientists as communicators: A randomized experiment to assess public reactions to scientists' social media communication along the science-advocacy continuum

    Science.gov (United States)

    Kotcher, J.; Vraga, E.; Myers, T.; Stenhouse, N.; Roser-Renouf, C.; Maibach, E.

    2014-12-01

    The question of what type of role scientists, or experts more generally, should play in policy debates is a perennial point of discussion within the scientific community. It is often thought that communication containing some form of policy advocacy is likely to compromise the perceived credibility of the individual scientist engaged in such behavior, with the possibility that it may also harm the credibility of the scientific community more broadly. Rather than evaluating statements in a binary fashion as representing either pure objectivity or pure advocacy, one recent model proposes that public communication by scientists should instead be thought of as falling along a continuum based upon the extent of normative judgment implicit in a statement. This approach predicts that as the extent of normative judgment increases, it poses a relatively greater risk to a scientist's perceived credibility. Though such a model is conceptually useful, little empirical social science research has systematically explored how individuals form judgments about different types of advocacy to examine common assumptions about the relative risks associated with such behaviors. In this presentation, we will report results from a national online experiment (N=1200) that examines audience responses to fictional social media posts written by either a climate scientist or a television weathercaster. Following the above model, the posts represent differing degrees of advocacy defined by the extent of normative judgment implicit in each statement. In instances where a specific policy is advocated, we examine whether participants' reactions are shaped by the extent to which the policy mentioned is congruent with one's political ideology. We hope this study will serve as an exemplar of applied science communication research that can begin to help inform scientists and other experts about the potential implications of different communication options they may choose from in deciding how to engage

  4. Instructional Media

    African Journals Online (AJOL)

    This can be summed up in a few words: Students can learn a great deal from any of the media. Under most of the conditions tested, they could learn as much as from ... Beyond physical conditions (deafness) there is little reason to expect a differential media. Scientia Militaria, South African Journal of Military Studies, Vol 13 ...

  5. Mixed Media

    Science.gov (United States)

    Peterson, Erin

    2010-01-01

    While institutions do not often have a hook as compelling as an eagerly awaited movie, great content is critical for media relations success--and coupling it with the right distribution channel can ensure the story finds the right audience. Even better, retooling it for several media platforms can extend the life and reach of a story. The changes…

  6. Media darling

    CERN Multimedia

    Chalmers, Matthew

    2008-01-01

    He is the media-friendly face of particle physics, appearing on countless TV and radio shows in the run-up to the opening of CERN's Large Hadron Collider. Matthew Chalmers discovers how Brian Cox finds the time to be both a physicist and a media personality. (2 pages)

  7. Media Art

    DEFF Research Database (Denmark)

    Ekman, Ulrik

    2015-01-01

    environments, experience time, and develop identities individually and socially. Interviews with working media artists lend further perspectives on these cultural transformations. Drawing on cultural theory, new media art studies, human-computer interaction theory, and software studies, this cutting-edge book...... critically unpacks the complex ubiquity-effects confronting us every day....

  8. Media violence.

    Science.gov (United States)

    Cantor, J

    2000-08-01

    Research on the effects of media violence is not well understood by the general public. Despite this fact, there is an overwhelming consensus in the scientific literature about the unhealthy effects of media violence. Meta-analyses show that media-violence viewing consistently is associated with higher levels of antisocial behavior, ranging from the trivial (imitative violence directed against toys) to the serious (criminal violence), with many consequential outcomes in between (acceptance of violence as a solution to problems, increased feelings of hostility, and the apparent delivery of painful stimulation to another person). Desensitization is another well-documented effect of viewing violence, which is observable in reduced arousal and emotional disturbance while witnessing violence, the reduced tendency to intervene in a fight, and less sympathy for the victims of violence. Although there is evidence that youth who are already violent are more likely to seek out violent entertainment, there is strong evidence that the relationship between violence viewing and antisocial behavior is bidirectional. There is growing evidence that media violence also engenders intense fear in children which often lasts days, months, and even years. The media's potential role in solutions to these problems is only beginning to be explored, in investigations examining the uses and effects of movie ratings, television ratings, and the V-chip, and the effects of media literacy programs and public education efforts. Future research should explore important individual differences in responses to media violence and effective ways to intervene in the negative effects.

  9. Porous media geometry and transports

    CERN Document Server

    Adler, Pierre

    1992-01-01

    The goal of ""Porous Media: Geometry and Transports"" is to provide the basis of a rational and modern approach to porous media. This book emphasizes several geometrical structures (spatially periodic, fractal, and random to reconstructed) and the three major single-phase transports (diffusion, convection, and Taylor dispersion).""Porous Media"" serves various purposes. For students it introduces basic information on structure and transports. Engineers will find this book useful as a readily accessible assemblage of al the major experimental results pertaining to single-phase tr

  10. Using Social Media for the Promotion of Education and Consultation in Adolescents Who Have Undergone Kidney Transplant: Protocol for a Randomized Control Trial.

    Science.gov (United States)

    Pase, Claudiana; Mathias, Andréia Dias; Garcia, Clotilde Druck; Garcia Rodrigues, Clarissa

    2018-01-09

    Falling ill represents a traumatic experience especially in adolescence, since in addition to the moments of ambiguity and contradictions that this period brings, there is coping with the disease. Renal transplantation provides a better quality of life but the dependence on dialysis is replaced by the greater responsibility of self-care. With advances in technology, contemporary communication methods are a strategic mechanism for the approximation of the adolescent and the multiprofessional team. In this perspective, our research may provide possible changes and propose alternatives, using social networks for the integration of the multiprofessional team, promoting education within a virtual environment for adolescents who have undergone kidney transplants. The goal of our research is to compare the knowledge, satisfaction, and self-esteem of adolescent renal transplant patients in 2 groups: patients undergoing conventional treatment versus patients undergoing conventional treatment plus the full-time use of social networks to aid in education and consultation. Nonblind randomized clinical trial with 128 adolescents (aged 13 to 21 years) divided in 2 groups: the first group will receive conventional care and the second group will be invited to participate in a secret group on the social network Facebook. This group will be used as a new education platform to involve young renal transplant patients to participate in the guidelines provided to them by the multiprofessional team. An environment for learning and exchanging life experiences will be created by using a well-known technology among adolescents. As a low-cost intervention, it will allow a better interaction between the patient and the transplant team. It is expected that the adolescents will improve their knowledge about the disease also increasing their self-esteem and the treatment adhesion. Health professionals need to seek alternatives when educating patients, focusing on easily understandable ways for

  11. Efficacy of 10-valent pneumococcal non-typeable Haemophilus influenzae protein D conjugate vaccine against acute otitis media and nasopharyngeal carriage in Panamanian children – A randomized controlled trial

    Science.gov (United States)

    Sáez-Llorens, Xavier; Rowley, Stella; Wong, Digna; Rodríguez, Mirna; Calvo, Arlene; Troitiño, Marisol; Salas, Albino; Vega, Vielka; Castrejón, Maria Mercedes; Lommel, Patricia; Pascal, Thierry G.; Hausdorff, William P.; Borys, Dorota; Ruiz-Guiñazú, Javier; Ortega-Barría, Eduardo; Yarzabal, Juan Pablo; Schuerman, Lode

    2017-01-01

    ABSTRACT We previously reported 10-valent pneumococcal non-typeable Haemophilus influenzae (NTHi) protein D conjugate vaccine (PHiD-CV) efficacy in a double-blind randomized trial (ClinicalTrials.gov: NCT00466947) against various diseases, including acute otitis media (AOM). Here, we provide further analyses. In the Panamanian subset, 7,359 children were randomized (1:1) to receive PHiD-CV or control vaccine at age 2/4/6 and 15–18 months. Of these, 2,000 had nasopharyngeal swabs collected. AOM cases were captured when parents sought medical attention for children with AOM symptoms; surveillance was enhanced approximately 2 y into the study through regular telephone calls or home visits by study personnel, who advised parents to visit the clinic if their child had AOM symptoms. Mean follow-up was 31.4 months. Clinical AOM (C-AOM) cases were assessed by physicians and confirmed by otorhinolaryngologists. Middle ear fluid samples, taken from children with C-AOM after specific informed consent, and nasopharyngeal samples were cultured for pathogen identification. For 7,359 children, 2,574 suspected AOM cases were assessed by a primary healthcare physician; 649 cases were C-AOM cases as per protocol definition. From the 503 MEF samples collected, 158 resulted in a positive culture. In the intent-to-treat cohort (7,214 children), PHiD-CV showed VE against first C-AOM (24.0% [95% CI: 8.7, 36.7]) and bacterial (B-AOM) episodes (48.0% [20.3, 66.1]) in children children younger than 24 months, and reduced vaccine-serotype NPC. PMID:28368738

  12. From Augmentation Media to Meme Media.

    Science.gov (United States)

    Tanaka, Yuzuru

    Computers as meta media are now evolving from augmentation media vehicles to meme media vehicles. While an augmentation media system provides a seamlessly integrated environment of various tools and documents, meme media system provides further functions to edit and distribute tools and documents. Documents and tools on meme media can easily…

  13. Long-term calcium supplementation may have adverse effects on serum cholesterol and carotid intima-media thickness in postmenopausal women: a double-blind, randomized, placebo-controlled trial.

    Science.gov (United States)

    Li, Songtao; Na, Lixin; Li, Ying; Gong, Liya; Yuan, Feifei; Niu, Yucun; Zhao, Yue; Sun, Changhao

    2013-11-01

    Several studies have focused on the effects of calcium intake on serum lipid concentrations in postmenopausal women. However, many premenopausal women are taking calcium supplements in China. To our knowledge, no studies have assessed whether the effects of calcium supplementation on blood lipids are similar between premenopausal and postmenopausal women. We assessed the effects of calcium supplementation on blood lipid concentrations in premenopausal and postmenopausal women with dyslipidemia. A total of 190 premenopausal women (30-40 y old) and 182 postmenopausal women (50-60 y old) with dyslipidemia were given 800 mg Ca/d or a placebo for 2 y in a double-blind, randomized, placebo-controlled trial. Blood pressure, fasting glucose and serum lipid concentrations, carotid intima-media thickness (CIMT), dietary nutrient intakes, and physical activity levels were determined at baseline and after 2 y. There was a significant interaction between calcium supplementation and menopausal status on serum cholesterol concentrations (P women (P women with dyslipidemia increases serum total cholesterol concentrations and CIMT. In postmenopausal women with dyslipidemia, calcium supplements should be prescribed with caution. This trial was registered at http://www.chictr.org/cn/ as ChiCTR-TRC-12002806.

  14. Contrast-induced nephropathy in patients with diabetes mellitus between iso- and low-osmolar contrast media: A meta-analysis of full-text prospective, randomized controlled trials.

    Science.gov (United States)

    Han, Xiao-Fang; Zhang, Xin-Xiu; Liu, Ke-Mei; Tan, Hua; Zhang, Qiu

    2018-01-01

    This study was conducted to compare iso-osmolar contrast medium, iodixanol, with low-osmolar contrast media (LOCM) for assessing contrast-induced nephropathy (CIN) incidence, exclusively in the diabetic population. A systematic search was conducted for full-text, prospective, randomized controlled trials (RCTs). The primary outcome was incidence of CIN. Medline, Cochrane Central Register of Controlled Trials, and other sources were searched until May 31, 2017. Twelve RCTs finally met the search criteria. Iodixanol did not significantly reduce the risk of CIN (risk ratio [RR]: 0.72, 95% confidence interval (CI): [0.49, 1.04], p = 0.08). However, there was significantly reduced risk of CIN when iodixanol was compared to a LOCM agent iohexol (RR: 0.32, 95% CI [0.12, 0.89]). There were no differences between iodixanol and the other non-iohexol LOCM (RR: 0.92, 95% CI [0.68, 1.25]). In diabetic populations, iodixanol is not associated with a significant reduction of CIN risk. Iodixanol is associated with a reduced risk of CIN compared with iohexol, whereas no significant difference between iodixanol and other LOCM could be found.

  15. A Method of Erasing Data Using Random Number Generators

    OpenAIRE

    井上,正人

    2012-01-01

    Erasing data is an indispensable step for disposal of computers or external storage media. Except physical destruction, erasing data means writing random information on entire disk drives or media. We propose a method which erases data safely using random number generators. These random number generators create true random numbers based on quantum processes.

  16. Media Training

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    With the LHC starting up soon, the world's media are again turning their attention to CERN. We're all likely to be called upon to explain what is happening at CERN to media, friends and neighbours. The seminar will be given by BBC television news journalists Liz Pike and Nadia Marchant, and will deal with the kind of questions we're likely to be confronted with through the restart period. The training is open for everybody. Make sure you arrive early enough to get a seat - there are only 200 seats in the Globe. The session will also be webcast: http://webcast.cern.ch/

  17. Social Media Sites

    Science.gov (United States)

    Media Sites Site Registration Contact Us Search AF.mil: Home > AF Sites > Social Media Sites Social Media Welcome to the Air Force social media directory! The directory is a one-stop shop of official Air Force social media pages across various social media sites. Social media is all about

  18. Contrast media

    International Nuclear Information System (INIS)

    Decazes, Ph.

    2004-01-01

    The Guerbet firm, which holds 69% of the capital on the contrast media for medical imagery, could sale about 20% of this capital in order to accelerate its development in the United States, one of its next market with the Japan. (O.M.)

  19. Otitis media

    NARCIS (Netherlands)

    Rovers, MM; Schilder, AGM; Zielhuis, GA; Rosenfeld, RM

    2004-01-01

    Otitis media (OM) continues to be one of the most common childhood infections and is a major cause of morbidity in children. The pathogenesis of OM is multifactorial, involving the adaptive and native immune system, Eustachian-tube dysfunction, viral and bacterial load, and genetic and environmental

  20. Social Media

    Science.gov (United States)

    2010-05-01

    Digital Marketing and Ecommerce Professionals. 29 January 2010. 20 May 2010. <http://econsultancy.com/blog/5324-20+-mind-blowing-social- media...Statistics Revisited.” Econsultancy | Community of Digital Marketing and Ecommerce Professionals. 29 Jan. 2010. 20 May 2010. <http://econsultancy.com/blog

  1. Streaming Media

    Science.gov (United States)

    Pulley, John

    2009-01-01

    At a time when the evolutionary pace of new media resembles the real-time mutation of certain microorganisms, the age-old question of how best to connect with constituents can seem impossibly complex--even for an elite institution plugged into the motherboard of Silicon Valley. Identifying the most effective vehicle for reaching a particular…

  2. Impacts on Breastfeeding Practices of At-Scale Strategies That Combine Intensive Interpersonal Counseling, Mass Media, and Community Mobilization: Results of Cluster-Randomized Program Evaluations in Bangladesh and Viet Nam.

    Science.gov (United States)

    Menon, Purnima; Nguyen, Phuong Hong; Saha, Kuntal Kumar; Khaled, Adiba; Kennedy, Andrew; Tran, Lan Mai; Sanghvi, Tina; Hajeebhoy, Nemat; Baker, Jean; Alayon, Silvia; Afsana, Kaosar; Haque, Raisul; Frongillo, Edward A; Ruel, Marie T; Rawat, Rahul

    2016-10-01

    Despite recommendations supporting optimal breastfeeding, the number of women practicing exclusive breastfeeding (EBF) remains low, and few interventions have demonstrated implementation and impact at scale. Alive & Thrive was implemented over a period of 6 y (2009-2014) and aimed to improve breastfeeding practices through intensified interpersonal counseling (IPC), mass media (MM), and community mobilization (CM) intervention components delivered at scale in the context of policy advocacy (PA) in Bangladesh and Viet Nam. In Bangladesh, IPC was delivered through a large non-governmental health program; in Viet Nam, it was integrated into government health facilities. This study evaluated the population-level impact of intensified IPC, MM, CM, and PA (intensive) compared to standard nutrition counseling and less intensive MM, CM, and PA (non-intensive) on breastfeeding practices in these two countries. A cluster-randomized evaluation design was employed in each country. For the evaluation sample, 20 sub-districts in Bangladesh and 40 communes in Viet Nam were randomized to either the intensive or the non-intensive group. Cross-sectional surveys (n ~ 500 children 0-5.9 mo old per group per country) were implemented at baseline (June 7-August 29, 2010, in Viet Nam; April 28-June 26, 2010, in Bangladesh) and endline (June 16-August 30, 2014, in Viet Nam; April 20-June 23, 2014, in Bangladesh). Difference-in-differences estimates (DDEs) of impact were calculated, adjusting for clustering. In Bangladesh, improvements were significantly greater in the intensive compared to the non-intensive group for the proportion of women who reported practicing EBF in the previous 24 h (DDE 36.2 percentage points [pp], 95% CI 21.0-51.5, p Viet Nam, EBF increases were greater in the intensive group (27.9 pp, 95% CI 17.7-38.1, p Viet Nam than standard counseling with less intensive MM, CM, and PA. To our knowledge, this study is the first to document implementation and impacts of

  3. Scattering and Propagation in Random Media

    Science.gov (United States)

    1988-01-01

    courts porno C~r) module Au champ darns Is pupille A,Ca)4 amplitude complex* Au chomp danms 1. plan focal OMf fouction As tranefert longue point do...instantenie N nosbre minimum d~imagem A utilimer doen les algorithmasm I noabre As taveluros prisontos darns V image courts porno N) noabre do moum

  4. 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.

  5. [Chronic otitis mediaChronic Otitis Media].

    Science.gov (United States)

    Kohles, N; Schulz, T; Eßer, D

    2015-11-01

    There are 2 different kinds of chronic otitis media: Otitis media chronica mesotympanalis and otitis media chronica epitympanalis (cholesteatoma). The incidence of chronic otitis media as reported in literature differs in a wide range. The incidence rates vary between 0.45 and 46%. Both, otitis media chronica mesotympanalis and cholesteatoma, lead to eardrum perforation due to lengthy and recurring inflammations. Furthermore, chronic otitis media is characterized by frequently recurring otorrhea and conductive hearing loss. Georg Thieme Verlag KG Stuttgart · New York.

  6. Use and Acceptance of Social Media among Health Educators

    Science.gov (United States)

    Hanson, Carl; West, Joshua; Neiger, Brad; Thackeray, Rosemary; Barnes, Michael; McIntyre, Emily

    2011-01-01

    Background: As social media use grows in popularity, health educators are challenged to think differently about how to communicate with audiences. Purpose: The purpose of this study was to explore social media use and factors that determine acceptance of social media use among health educators. Methods: A random sample of Certified Health…

  7. On Media Education

    Science.gov (United States)

    Fedorov, Alexander

    2008-01-01

    This monograph analyzes the theory and practice of media education and media literacy. The book also includes the list of Russian media education literature and addresses of websites of the associations for media education.

  8. Otitis media.

    Science.gov (United States)

    Schilder, Anne G M; Chonmaitree, Tasnee; Cripps, Allan W; Rosenfeld, Richard M; Casselbrant, Margaretha L; Haggard, Mark P; Venekamp, Roderick P

    2016-09-08

    Otitis media (OM) or middle ear inflammation is a spectrum of diseases, including acute otitis media (AOM), otitis media with effusion (OME; 'glue ear') and chronic suppurative otitis media (CSOM). OM is among the most common diseases in young children worldwide. Although OM may resolve spontaneously without complications, it can be associated with hearing loss and life-long sequelae. In developing countries, CSOM is a leading cause of hearing loss. OM can be of bacterial or viral origin; during 'colds', viruses can ascend through the Eustachian tube to the middle ear and pave the way for bacterial otopathogens that reside in the nasopharynx. Diagnosis depends on typical signs and symptoms, such as acute ear pain and bulging of the tympanic membrane (eardrum) for AOM and hearing loss for OME; diagnostic modalities include (pneumatic) otoscopy, tympanometry and audiometry. Symptomatic management of ear pain and fever is the mainstay of AOM treatment, reserving antibiotics for children with severe, persistent or recurrent infections. Management of OME largely consists of watchful waiting, with ventilation (tympanostomy) tubes primarily for children with chronic effusions and hearing loss, developmental delays or learning difficulties. The role of hearing aids to alleviate symptoms of hearing loss in the management of OME needs further study. Insertion of ventilation tubes and adenoidectomy are common operations for recurrent AOM to prevent recurrences, but their effectiveness is still debated. Despite reports of a decline in the incidence of OM over the past decade, attributed to the implementation of clinical guidelines that promote accurate diagnosis and judicious use of antibiotics and to pneumococcal conjugate vaccination, OM continues to be a leading cause for medical consultation, antibiotic prescription and surgery in high-income countries.

  9. Media matters.

    Science.gov (United States)

    Martinez, L M

    1995-01-01

    The impact of the mass media on woman's status was addressed at two 1995 conferences: the Fourth World Conference on Women, held in Beijing, China, and the Congress of the World Association for Christian Communication, held in Puebla, Mexico. The globalization process facilitated by the mass media has served to increase the power of patriarchy, with no advantages to the cause of women's rights. Coverage of popular movements has been suppressed out of deference to male-controlled governments. Coverage of the Beijing Conference highlighted celebrities and personal stories, to the exclusion of the economic and political issues under debate. Television has commodified women, reinforcing their oppression. On the other hand, the alternative media, which tend to be decentralized, democratic, low-cost, and low in technology, are presenting women as subjects rather than objects and deconstructing gender stereotypes. Of concern, however, is the tendency of computer technology to widen the gap between social classes and developed and developing countries. Women must use information networks to disseminate information on women's rights and strengthen the links between women throughout the world.

  10. Media Education Initiatives by Media Organizations: The Uses of Media Literacy in Hong Kong Media

    Science.gov (United States)

    Chu, Donna; Lee, Alice Y. L.

    2014-01-01

    As more media organizations have engaged in media education, this paper investigates the goals and practices of these activities. This article coins media education initiatives by media organizations with the term "media-organization media literac"y (MOML). Four MOML projects in Hong Kong were selected for examination. Built on critical…

  11. Reproducibility of artificial multiple scattering media

    NARCIS (Netherlands)

    Marakis, Evangelos; van Harten, Wouter; Uppu, Ravitej; Pinkse, Pepijn Willemszoon Harry

    2016-01-01

    State of the art authentication systems depend on physical unclonable functions (PUF) [1], physical keys that are assumed unclonable due to technological constraints. Random scattering media, dielectric materials with rapid and random refractive index variations, are considered as ideal optical PUFs

  12. Evaluation of a High Concentrated Contrast Media Injection Protocol in Combination with Low Tube Current for Dose Reduction in Coronary Computed Tomography Angiography: A Randomized, Two-center Prospective Study.

    Science.gov (United States)

    Sun, Yibo; Hua, Yanqing; Wang, Mingpeng; Mao, Dingbiao; Jin, Xiu; Li, Cheng; Shi, Kailei; Xu, Jianrong

    2017-12-01

    The study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography. Eighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18-31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5.0 mL/s), and iodine dose (22.8 g). An automatic mAs and low concentration contrast medium (300 mgI/mL) were used in group A, whereas effective mAs was reduced by a factor 0.6 along with HCCM (400 mgI/mL) in group B. Radiation dose was assessed (CT dose index [CTDI vol ] and dose length product), and vessel-based objective IQ for various regions of interest (enhancement, noise, signal-to-noise ratio, and contrast-to-noise ratio), subjective IQ, noise, and motion artifacts were analyzed overall and vessel-based with a 5-point Likert scale. The CT attenuation of coronary arteries and image noise in group B were significantly higher than those in group A (ranges: 507.5-548.1 Hounsfield units vs 407.5-444.5 Hounsfield units; and 20.3 ± 8.6 vs 17.7 ± 8.0) (P ≤ 0.0166). There was no significant difference between the two groups in signal-to-noise ratio, contrast-to-noise ratio, and subjective IQ of coronary arteries (29.4-31.7, 30.0-37.0, and medium score of 5 in group A vs 29.4-32.4, 27.7-36.3, and medium score of 5 in group B, respectively, P ≥ 0.1859). Both mean CTDI vol and dose length product in group B were 58% of those of group A. HCCM combined with low tube current allows dose reduction in coronary computed tomography angiography and does not compromise IQ. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  13. Media Matter

    Directory of Open Access Journals (Sweden)

    Holger Pötzsch

    2017-02-01

    Full Text Available The present contribution maps materialist advances in media studies. Based on the assumption that matter and materiality constitute significant aspects of communication processes and practices, I introduce four fields of inquiry - technology, political economy, ecology, and the body - and argue that these perspectives enable a more comprehensive understanding of the implications of contemporary technologically afforded forms of interaction. The article shows how each perspective can balance apologetic and apocalyptic approaches to the impact of in particular digital technologies, before it demonstrates the applicability of an integrated framework with reference to the techno-politics of NSA surveillance and the counter-practices of WikiLeaks.

  14. Media education and media influence on youth

    OpenAIRE

    LILÁK, Karel

    2011-01-01

    Bachelor´s work is focused on the questions of the medial education and the medias themselves. This work also investigate with the influence of the action of medias to the students of apprenticeship. The first part of the theoretical work has generally explains what is media education, what is its significance for society and for the benefit of education in school. They are given functions, types and objectives of media education and communications capabilities via the media. The second part ...

  15. Managing Media: Segmenting Media Through Consumer Expectancies

    Directory of Open Access Journals (Sweden)

    Matt Eastin

    2014-04-01

    Full Text Available It has long been understood that consumers are motivated to media differently. However, given the lack of comparative model analysis, this assumption is without empirical validation, and thus, the orientation of segmentation from a media management perspective is without motivational grounds. Thus, evolving the literature on media consumption, the current study develops and compares models of media segmentation within the context of use. From this study, six models of media expectancies were constructed so that motivational differences between media (i.e., local and national newspapers, network and cable television, radio, and Internet could be observed. Utilizing higher order statistical analyses the data indicates differences across a model comparison approach for media motivations. Furthermore, these differences vary across numerous demographic factors. Results afford theoretical advancement within the literature of consumer media consumption as well as provide media planners’ insight into consumer choices.

  16. THE CHECHEN WARS, MEDIA, AND DEMOCRACY IN RUSSIA

    Directory of Open Access Journals (Sweden)

    Ali Askerov

    2015-05-01

    Full Text Available Media, like religion, may create, escalate, or deescalate conflict. In the age of technology, parties to protracted conflicts often use the media for their propaganda purposes. In many cases, despite politically created discourses, individual media members struggle to reveal the truth of the violent confrontation that causes human casualties. This paper discusses Moscow’s tough media policy during the Chechen wars, especially from 1999 to 2009 during the Second Chechen War, and argues that Kremlin’s severe media policy in the course of the height of this violent conflict negatively affected the values of democracy in Russia. Nonetheless, Russia’s new media policy had affected different media means differently depending on their missions and commitment. To produce this paper, data were collected through interviewing twenty-two Chechen nationals, including media experts, and randomly analyzing the contents of the Russian media and Chechen websites available online.

  17. 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

  18. Geographic Media Literacy

    Science.gov (United States)

    Lukinbeal, Chris

    2014-01-01

    While the use of media permeates geographic research and pedagogic practice, the underlying literacies that link geography and media remain uncharted. This article argues that geographic media literacy incorporates visual literacy, information technology literacy, information literacy, and media literacy. Geographic media literacy is the ability…

  19. Adolescents and media literacy.

    Science.gov (United States)

    McCannon, Robert

    2005-06-01

    In the face of media industry consolidation, fewer people control media content which makes it harder for parents and citizens to know the research about media-related issues, such as video game violence, nutrition, and sexual risk-taking. Media literacy offers a popular and potentially successful way to counter the misinformation that is spread by Big Media public relations.

  20. Safety in online media – freedom of the media; safety of media actors and media education

    OpenAIRE

    Moeller, Ch

    2013-01-01

    In this paper, prepared for the international conference ‘Mass Media – Society – Education: Media Safety Problems’ at the Chelyabinsk State University’s Department for Journalism and Media Education from September 30 – October 3, 2013, I would like to address three dimensions of media safety and security in online media.

  1. SOCIAL MEDIA SECURITY

    Science.gov (United States)

    RESPONSIBILITY CENTCOM COALITION MEDIA SOCIAL MEDIA NEWS ARTICLES PRESS RELEASES IMAGERY VIDEOS TRANSCRIPTS VISITORS AND PERSONNEL FAMILY CENTER FAMILY READINESS CENTCOM WEBMAIL SOCIAL MEDIA SECURITY ACCOUNTABILITY HomeVISITORS AND PERSONNELSOCIAL MEDIA SECURITY FAQ on Security for Social Media Due to the widespread use of

  2. Measuring News Media Literacy

    Science.gov (United States)

    Maksl, Adam; Ashley, Seth; Craft, Stephanie

    2015-01-01

    News media literacy refers to the knowledge and motivations needed to identify and engage with journalism. This study measured levels of news media literacy among 500 teenagers using a new scale measure based on Potter's model of media literacy and adapted to news media specifically. The adapted model posits that news media literate individuals…

  3. Media Literacy in Times of Media Divides

    Directory of Open Access Journals (Sweden)

    Kaja Žuran

    2013-12-01

    Full Text Available We live in a post-modern society, an information society, a society based around knowledge and participation, and above all in a media society. In a media culture where media holds a dominant position, we cannot overlook the emerging idea of a ‘media divide’ within the frame of media education, media literate individuals and the expansion of the traditional concept of media literacy. Firstly, we are in an era of technological revolution, and it is time to consider the meaning and function of media and how we experience it in our everyday life. Secondly, as a society we are subject to intense media invasion and we all need to learn how to use it to our benefit and apply a critical and autonomous perspective towards selecting media content. Otherwise the media divide between the media literate and illiterate will widen; but is there even a chance to overcome the supposed divide between those who are formally media educated and those who are not?

  4. Otitis media with effusion

    Science.gov (United States)

    OME; Secretory otitis media; Serous otitis media; Silent otitis media; Silent ear infection; Glue ear ... from the tube and is swallowed. OME and ear infections are connected in two ways: After most ear ...

  5. Intermediality and media change

    OpenAIRE

    2012-01-01

    This book is about intermediality as an approach to analysing and understanding media change. Intermediality and Media Change is critical of technological determinism that characterises 'new media discourse' about the ongoing digitalization, framed as a revolution and creating sharp contrasts between old and new media. Intermediality instead emphasises paying attention to continuities between media of all types and privileges a comparative perspective on technological changes in media over ti...

  6. Media Pembelajaran Global Warming

    OpenAIRE

    Tham, Fikri Jufri; Liliana, Liliana; Purba, Kristo Radion

    2016-01-01

    Computer based learning media is one of the media has an important role in learning. Learning media will be attractive when packaged through interactive media , such as interactive media created in paper manufacture " instructional media global warming" . The advantage gained is that it can increase knowledge, generally educate people to be more concerned about the environment , and also can be a means of entertainment. This application is focused to learn about global warming and packaged in...

  7. Social media management and media environment

    Directory of Open Access Journals (Sweden)

    Šiđanin Iva

    2012-01-01

    Full Text Available The paper deals with the system of services that social media management can offer to a variety of users. As social media systems are emerging, social media management can strengthen teams in social media and help to manage numerous social channels and distribution of social information from one place. Social media management is a system of procedures that are used to manage the flow of information in the environment of social media. This involves connecting with social media like Facebook, Twitter, LinkedIn, Plaxo, Ecademy, YouTube and many others, then the aggregation and management of social data. Social media management services are analysed through various fields, such as managing multiple social media profiles, mail scheduling and filtering, reporting and analytics. Social media management enables managing personal business through social media, which contributes to a significant reduction in expenditures. The paper also discusses the importance of social media management in marketing activities and various forms of social promotion, which allow companies to easily reach their customers.

  8. Mass media for smoking cessation in adolescents.

    Science.gov (United States)

    Solomon, Laura J; Bunn, Janice Y; Flynn, Brian S; Pirie, Phyllis L; Worden, John K; Ashikaga, Takamaru

    2009-08-01

    Theory-driven, mass media interventions prevent smoking among youth. This study examined effects of a media campaign on adolescent smoking cessation. Four matched pairs of media markets in four states were randomized to receive or not receive a 3-year television/radio campaign aimed at adolescent smoking cessation based on social cognitive theory. The authors enrolled 2,030 adolescent smokers into the cohort (n = 987 experimental; n = 1,043 comparison) and assessed them via annual telephone surveys for 3 years. Although the condition by time interaction was not significant, the proportion of adolescents smoking in the past month was significantly lower in the experimental than comparison condition at 3-year follow-up when adjusted for baseline smoking status. The media campaign did not impact targeted mediating variables. A media campaign based on social cognitive constructs produced a modest overall effect on smoking prevalence among adolescents, but the role of theory-based constructs is unclear.

  9. Media Literacy Bibliography.

    Science.gov (United States)

    Duncan, Barry

    1989-01-01

    Provides an up-to-date bibliography of resources available for teaching media literacy. Groups resources into the areas of media education methodology, mass media texts, general background, television, film, the news and medium of print, advertising, gender and the media, popular culture, popular music and rock video, periodicals, and…

  10. Understanding Social Media Logic

    OpenAIRE

    José van Dijck; Thomas Poell

    2013-01-01

    Over the past decade, social media platforms have penetrated deeply into the mech­anics of everyday life, affecting people's informal interactions, as well as institutional structures and professional routines. Far from being neutral platforms for everyone, social media have changed the conditions and rules of social interaction. In this article, we examine the intricate dynamic between social media platforms, mass media, users, and social institutions by calling attention to social media log...

  11. Social media influencer marketing

    OpenAIRE

    Isosuo, Heli

    2016-01-01

    The marketing field is changing simultaneously with the digital world. Social media is getting more and more important to marketers, and there is a need to stand out in the social media noise. Social media influencer marketing could be a good alternative to other types of marketing. A need from the consignor and the interest of the author were the motivations for conducting the study. Sääskilahti Consulting has a social media influencer network Somevaikuttajat, which is offering social media ...

  12. 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

  13. Unpacking New Media Literacy

    Directory of Open Access Journals (Sweden)

    Der-Thanq “victor” Chen

    2011-04-01

    Full Text Available The 21st century has marked an unprecedented advancement of new media. New media has become so pervasive that it has penetrated into every aspect of our society. New media literacy plays an essential role for any citizen to participate fully in the 21st century society. Researchers have documented that literacy has evolved historically from classic literacy (reading-writing-understanding to audiovisual literacy to digital literacy or information literacy and recently to new media literacy. A review of literature on media literacy reveals that there is a lack of thorough analysis of unique characteristics of new media and its impacts upon the notion of new media literacy. The purpose of the study is to unpack new media literacy and propose a framework for a systematic investigation of new media literacy.

  14. Parenting and Digital Media.

    Science.gov (United States)

    Coyne, Sarah M; Radesky, Jenny; Collier, Kevin M; Gentile, Douglas A; Linder, Jennifer Ruh; Nathanson, Amy I; Rasmussen, Eric E; Reich, Stephanie M; Rogers, Jean

    2017-11-01

    Understanding the family dynamic surrounding media use is crucial to our understanding of media effects, policy development, and the targeting of individuals and families for interventions to benefit child health and development. The Families, Parenting, and Media Workgroup reviewed the relevant research from the past few decades. We find that child characteristics, the parent-child relationship, parental mediation practices, and parents' own use of media all can influence children's media use, their attitudes regarding media, and the effects of media on children. However, gaps remain. First, more research is needed on best practices of parental mediation for both traditional and new media. Ideally, this research will involve large-scale, longitudinal studies that manage children from infancy to adulthood. Second, we need to better understand the relationship between parent media use and child media use and specifically how media may interfere with or strengthen parent-child relationships. Finally, longitudinal research on how developmental processes and individual child characteristics influence the intersection between media and family life is needed. The majority of children's media use takes place within a wider family dynamic. An understanding of this dynamic is crucial to understanding child media use as a whole. Copyright © 2017 by the American Academy of Pediatrics.

  15. Iodinated contrast media nephrotoxicity

    International Nuclear Information System (INIS)

    Meyrier, A.

    1994-01-01

    In the late seventies, iodinated contrast agents (ICA) were considered to be a major cause of acute iatrogenic renal failure. Over the last decade new contrast agents have been synthesized, nonionic and less hyperosmolar. The incidence of acute renal failure due to ICAs, varies from 3.7 to 70% of cases according to the series, with an average figure of 10.2%. The pathophysiology of ICA nephrotoxicity was mainly studied in laboratory animal models. Three main factors are involved in an inducing ICA-mediated decrease in glomerular filtration rate: reduction of the renal plasma flow, a direct cytotoxic effect on renal tubular cells and erythrocyte alteration leading to intra-renal sludge. Excluding dysglobulinemias with urinary excretion of immunoglobulin light chains, which represent a special case of maximum nephrotoxicity, 4 main risk factors of renal toxicity have been identified in nondiabetic subjects: previous renal failure with serum creatinine levels greater than 140 μmol per liter, extracellular dehydration, age over 60 and use of high doses of ICA and/or repeated ICA injections before serum creatinine levels return to baseline. Preventive measures for avoiding ICA nephrotoxicity are threefold: maintain or restore adequate hydration with saline infusion, stop NSAID treatment several days before ICA administration, and allow a 5 day interval before repeating contrast media injections. New, nonionic and moderately hyperosmolar contrast agents appear to be much less nephrotoxic than conventional ICAs in laboratory animals and in high-risk patients. It is advisable to select such contrast media for investigating high-risk patients. This approach was recently substantiated in well designed, randomized clinical studies which included more than 2 000 patients. (author)

  16. Media Literacy Interventions: What Makes Them Boom or Boomerang?

    Science.gov (United States)

    Byrne, Sahara

    2009-01-01

    This study advances research on media literacy by comparing the effectiveness of two versions of a media literacy intervention over time. Participants (156 children in 4th or 5th grade) were randomly assigned to one of two treatment groups or a control group. Both treatment groups were exposed to an instructional intervention designed to reduce…

  17. Mass Media: The Invisible Environment.

    Science.gov (United States)

    Glessing, Robert J.; White, William P.

    This anthology for students of media consists of essays and articles grouped under four topics: media forms, media content, media environments, and "the last word." Media forms deals with the nature of these kinds of media: electronic, print, film, music, and comics, graffiti, and clothing. Media content contains articles on the news, advertising,…

  18. Media representations of Zimbabwean women migrants

    African Journals Online (AJOL)

    The article draws on 575 randomly selected articles from the South African Media database to explore the representation of Zimbabwean women migrants. Using critical discourse analysis (CDA), the article shows that some of the dominant construction types depict a picture of caricatured, stereotypical and stigmatised ...

  19. Media Pluralism and Diversity

    DEFF Research Database (Denmark)

    In the western world, a diverse and pluralistic media landscape is deemed essential for democracy. But how universal is media pluralism as a concept underpinning media policies? To what extent do normative approaches, regulatory dimensions and monitoring systems differ throughout the world......? Adopting a truly global, theoretical and multidisciplinary perspective, Media Pluralism and Diversity advances our understanding of media pluralism across the globe. It compares metrics developed in different parts of the world to assess levels of, or threats to, media pluralism. It identifies common...

  20. Social Media Reputation

    DEFF Research Database (Denmark)

    Etter, Michael Andreas; Ravasi, Davide; Colleoni, Elanor

    motivational drivers and contextual conditions associated with the formation of narratives in traditional news media and social media influence their content, diffusion, and impact significantly. Our analysis suggests that current theories of media reputation may provide an incomplete representation......Social media enable millions of users to create and disseminate narratives about organizations that increase their public exposure and shape public perceptions. In this paper, we draw on the sociology of news production and research on computer-mediated communication to discuss how different...... of the phenomenon, and highlight theoretically relevant differences and interrelationships between reputational dynamics involving news media and social media....

  1. 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

  2. AMAMM - All Media Are Mixed Media

    DEFF Research Database (Denmark)

    All Media Are Mixed Media Alle medier er blandingsmedier. Alle kunstarter er kompositte. Alle sanser er sammensatte. Alle medialiteter er miksede og mangfoldige. Alle er AMAMM. Denne påstand står centralt i ord-, billed- og medie-teoretikeren W.J.T. Mitchells forfatterskab. I hosstående bog tager...

  3. Catholic Media and Youth.

    Science.gov (United States)

    Nunes, Stephen A.

    1980-01-01

    Discusses the impact of media on youth and suggests some possible directions for the Catholic media, especially in the areas of textbooks, magazines, television, movies, and radio, in responding to the needs of youth. (Author/FM)

  4. Nurses and social media.

    Science.gov (United States)

    Farrelly, Rory

    Nurses' use of social media and other electronic communications has increased significantly with growing numbers of social media opportunities, platforms and applications including blogs, social networking sites, video sites and online chat rooms and forums.

  5. Media and Crime

    DEFF Research Database (Denmark)

    Agger, Gunhild; Waade, Anne Marit

    2011-01-01

    Recent developments in the relationship between media and crime are analyzed, taking both fiction and journalism in account......Recent developments in the relationship between media and crime are analyzed, taking both fiction and journalism in account...

  6. Development of contrast media

    International Nuclear Information System (INIS)

    Krause, W.

    1993-01-01

    Description of all contrast media (ionic and nonionic monomers, ionic and nonionic dimers) was presented. Chemotoxicity, osmolality and viscosity of some contrast agents were analyzed. The main adverse reactions to ionic and nonionic contrast media were described

  7. The social media revolution.

    Science.gov (United States)

    Dubose, Cheryl

    2011-01-01

    The growing popularity and use of social media tools such as Facebook, YouTube, Twitter, blogging, and wikis have led to a social media revolution. Given this widespread influence, it is important for educators, administrators, and technologists to understand the risks of using social media in the classroom and workplace. To investigate popular social media sites and their effect on radiologic technology education and business practices. A comprehensive search of literature was performed to examine social media and its applications in education, health care, and business. Social media use is on the rise, affecting all aspects of mainstream society. Leaders in the radiologic sciences should be familiar with social media and cognizant of its risks. Future studies regarding social media use in the radiologic sciences are necessary to determine its effect on the radiologic science community. ©2011 by the American Society of Radiologic Technologists.

  8. MODERN MEDIA EDUCATION MODELS

    Directory of Open Access Journals (Sweden)

    Alexander Fedorov

    2011-03-01

    Full Text Available The author supposed that media education models can be divided into the following groups:- educational-information models (the study of the theory, history, language of media culture, etc., based on the cultural, aesthetic, semiotic, socio-cultural theories of media education;- educational-ethical models (the study of moral, religions, philosophical problems relying on the ethic, religious, ideological, ecological, protectionist theories of media education;- pragmatic models (practical media technology training, based on the uses and gratifications and ‘practical’ theories of media education;- aesthetical models (aimed above all at the development of the artistic taste and enriching the skills of analysis of the best media culture examples. Relies on the aesthetical (art and cultural studies theory; - socio-cultural models (socio-cultural development of a creative personality as to the perception, imagination, visual memory, interpretation analysis, autonomic critical thinking, relying on the cultural studies, semiotic, ethic models of media education.

  9. Asian Media Productions

    DEFF Research Database (Denmark)

    This work consists of 12 essays on different aspects of Asian media by Japanese, European, and American scholars, many of whom have themselves been involved in the production of media forms. Working in the fields of anthropology, media and cultural studies, and on the basis of hands-on research, ......, they have written a book on the social practices and cultural attitudes of people producing, reading, watching and listening to different kinds of media in Japan, China, Taiwan, Indonesia, Vietnam, Singapore and India....

  10. Advertising on social media

    OpenAIRE

    Sumit Goyal

    2013-01-01

    This communication reports the latest trends of advertising on social media. Social media advertising means to gain traffic or attention of online users through social media sites. Today, when a user thinks about buying something, he first comes to the internet, searches for that product, compares its price with other competing brands and takes a decision, which one to buy. In this write-up, author has discussed many aspects concerning advertising through social media, viz., what is social me...

  11. Procedural Media Representation

    OpenAIRE

    Henrysson, Anders

    2002-01-01

    We present a concept for using procedural techniques to represent media. Procedural methods allow us to represent digital media (2D images, 3D environments etc.) with very little information and to render it photo realistically. Since not all kind of content can be created procedurally, traditional media representations (bitmaps, polygons etc.) must be used as well. We have adopted an object-based media representation where an object can be represented either with a procedure or with its trad...

  12. 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)

  13. IVF culture media: past, present and future.

    Science.gov (United States)

    Chronopoulou, Elpiniki; Harper, Joyce C

    2015-01-01

    The advances in the world of IVF during the last decades have been rapid and impressive and culture media play a major role in this success. Until the 1980s fertility centers made their media in house. Nowadays, there are numerous commercially available culture media that contain various components including nutrients, vitamins and growth factors. This review goes through the past, present and future of IVF culture media and explores their composition and quality assessment. A computerized search was performed in PubMed regarding IVF culture media including results from 1929 until March 2014. Information was gathered from the websites of companies who market culture media, advertising material, instructions for use and certificates of analysis. The regulation regarding IVF media mainly in the European Union (EU) but also in non-European countries was explored. The keyword 'IVF culture media' gave 923 results in PubMed and 'embryo culture media' 12 068 results dating from 1912 until March 2014, depicting the increased scientific activity in this field. The commercialization of IVF culture media has increased the standards bringing a great variety of options into clinical practice. However, it has led to reduced transparency and comparisons of brand names that do not facilitate the scientific dialogue. Furthermore, there is some evidence suggesting that suboptimal culture conditions could cause long-term reprogramming in the embryo as the periconception period is particularly susceptible to epigenetic alterations. IVF media are now classified as class III medical devices and only CE (Conformité Européene)-marked media should be used in the EU. The CE marking of IVF culture media is a significant development in the field. However, the quality and efficiency of culture media should be monitored closely. Well-designed randomized controlled trials, large epidemiological studies and full transparency should be the next steps. Reliable, standardized models assessing

  14. Media Education: Sociology Surveys

    Science.gov (United States)

    Fedorov, Alexander

    2007-01-01

    In Russia as well as in foreign countries we can witness sort of the confusion of the terms of "media education" and "media literacy". There are quite a few differences in theoretical approaches to media education, to distinguishing of the most important aims, objectives, means of introduction into the teaching process, etc.…

  15. Modern Media Education Models

    Science.gov (United States)

    Fedorov, Alexander

    2011-01-01

    The author supposed that media education models can be divided into the following groups: (1) educational-information models (the study of the theory, history, language of media culture, etc.), based on the cultural, aesthetic, semiotic, socio-cultural theories of media education; (2) educational-ethical models (the study of moral, religions,…

  16. Open Media Science

    DEFF Research Database (Denmark)

    Martiny, Kristian Møller Moltke; Pedersen, David Budtz; Hansted, Alfred Birkegaard

    2016-01-01

    and extend into a fully-fledged Open Media movement engaging with new media and non-traditional formats of science communication. We discuss two cases where experiments with open media have driven new collaborations between scientists and documentarists. We use the cases to illustrate different advantages...

  17. Children's Media Policy

    Science.gov (United States)

    Jordan, Amy B.

    2008-01-01

    Amy Jordan addresses the need to balance the media industry's potentially important contributions to the healthy development of America's children against the consequences of excessive and age-inappropriate media exposure. Much of the philosophical tension regarding how much say the government should have about media content and delivery stems…

  18. Social Media Empowerment (I)

    NARCIS (Netherlands)

    A. Cox

    2011-01-01

    full text via link. Social media stellen mensen, merken en bedrijven in staat om zichzelf te versterken. Soms wordt optimaal gebruik gemaakt van Social Media Empowerment, maar soms ook wat minder. Effectief inzetten van social media. Regel 1: Start met context en motivatie

  19. Youth media lifestyles

    NARCIS (Netherlands)

    van Kruistum, Claudia; Leseman, Paul Pm; de Haan, Mariëtte

    2014-01-01

    In this article, the concept of "media lifestyles" is adopted in order to develop a comprehensive approach toward youth engagement in communication media. We explore how 503 Dutch eighth grade students with full access to new technology combine a broad range of media by focusing on their engagement

  20. Sizing Up Social Media

    Science.gov (United States)

    Pearson, Jerold

    2010-01-01

    Most people are aware of the increasing importance of social media to institutional advancement, and many colleges and universities have started investing resources in these media. The next step is to measure the impact of social media on the institution and evaluate the success of one's efforts. Every advancement leader should understand how…

  1. The Media Reader.

    Science.gov (United States)

    Valdes, Joan; Crow, Jeanne

    An anthology of readings in the media correlates chapter-by-chapter to the authors' textbook, "The Media Works." Fifteen chapters cover the study of newspapers, magazines, comics, popular music, television, movies, and advertising. The authors included represent varied perspectives on the media. The selections were chosen with the help of a…

  2. Media and child development

    NARCIS (Netherlands)

    Piotrowski, J.T.; Vossen, H.G.M.; Valkenburg, P.M.; Wright, J.D.

    2015-01-01

    Decades of research have shown that the relationship between media and childhood is not unidirectional but reciprocal. In this article, both directions of the media-child development relationship are presented. We discuss how child development predisposes children's media use and preferences by

  3. Notes for media reinvention

    Directory of Open Access Journals (Sweden)

    Jesús Miguel Flores-Vivar

    2009-10-01

    Full Text Available Journalism and media are going through a change of era. This change is reflected in the transformation of journalism and media-lived and that another major in 1980 that became known as mediamorphosis, by this, professionals have to learn new roles. The impact of information technology and Internet has changed the way how you present the news and, most importantly, transform the business model that has characterized media companies. This article analyzes the current situation provides some strategic guidelines to be followed by some media-and-do and studied some of the new profiles arebeginning to emerge as a result of the reinvention of journalism and the media.

  4. Prosocial effects of media.

    Science.gov (United States)

    Hogan, Marjorie J

    2012-06-01

    Parents, teachers, health care providers, and other caring adults worry about the harmful influence of media messages and images on children and teens and wonder how to recognize and encourage positive and healthy use of media. For decades, experts have commented on the power of media. Media depictions can lead to negative attitudes and behavior in some young viewers. This article discusses whether prosocial, tolerant, and cooperative attitudes and behavior can be learned and imitated by children and adolescents and whether media can nurture or stimulate creativity or actively promote health and well-being in young consumers. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Comprehension of digital media

    International Nuclear Information System (INIS)

    Kim, Ju Hwan

    2008-11-01

    This book is divided four parts. The first part describes media and mark on sign and media, what is the sign?, interpretation of sign and semiotics. The second part is for production sign theory and origin of digital revolution such as the problem of origin of digital revolution, homogeneity of producing goods and sign : triple triangle model for production sign theory, triple triangle model for producing goods, triple triangle model of producing sign and triple triangle model of art works. The third parts deals with development of the media and meaning of digital revolution with four changes : invention of letter, appearance of printed media and establishment modernity, appearance electronic media and mess media and appearance of digital media. The last part mentions ontology of world wide web.

  6. The Media Mixer

    DEFF Research Database (Denmark)

    Vestergaard, Vitus; Mortensen, Christian Hviid

    2011-01-01

    content. The media content is created by the user in the museum's physical environment, but it can be mixed with material from web archives. It is the intention that the users learn about media through participatory and creative processes with media where the borders between producing, playing......We explore how remixing and content sharing can be used as a means for user participation in a digital museum age. Remix culture is seen as a culture that allows and encourages the production of derivative works; works that are based on already existing works. This cultural practice thrives...... throughout the Internet, most notably on web 2.0 sites like YouTube. The Media Museum has embraced the remix paradigm with the development of an interactive media experience centre called the Media Mixer. Here the museum users can produce, deconstruct, reconstruct and finally publish and share digital media...

  7. Radiographic contrast media

    International Nuclear Information System (INIS)

    Golman, K.; Holtz, E.; Almen, T.

    1987-01-01

    Contrast media are used in diagnostic radiology to enhance the X-ray attenuation between a body structure of interest and the surrounding tissue. A detail becomes perceptible on a roentgenogram only when its contrast exceeds a minimum value in relation to the background. Small areas of interest must have higher contrast than the background. The contrast effect depends on concentration of the contrast media with the body. A high contrast media concentration difference thus gives rise to more morphological details in the radiographs. Contrast media can be divided into negative contrast media such as air and gas which attenuate X-rays less than the body tissues, and positive contrast materials which attenuate X-rays more than the body tissues. The positive contrast media all contain either iodine (atomic number 53) or barium (atomic number 56) and can be divided into water-insoluble and water-soluble contrast media

  8. Comprehension of digital media

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Hwan

    2008-11-15

    This book is divided four parts. The first part describes media and mark on sign and media, what is the sign?, interpretation of sign and semiotics. The second part is for production sign theory and origin of digital revolution such as the problem of origin of digital revolution, homogeneity of producing goods and sign : triple triangle model for production sign theory, triple triangle model for producing goods, triple triangle model of producing sign and triple triangle model of art works. The third parts deals with development of the media and meaning of digital revolution with four changes : invention of letter, appearance of printed media and establishment modernity, appearance electronic media and mess media and appearance of digital media. The last part mentions ontology of world wide web.

  9. Media:Time card stack

    NARCIS (Netherlands)

    Annemarie Wennekers; Jos de Haan; Frank Huysmans

    2016-01-01

    Original title: Media:Tijd in kaart The Dutch spend a daily average of 8 hours 33 minutes using media. Men and people aged over 50 spend most time using media, at an average of 9 hours per day. Older media users prefer traditional media and devices over new media and modern devices. Young and

  10. Understanding Social Media Logic

    Directory of Open Access Journals (Sweden)

    José van Dijck

    2013-08-01

    Full Text Available Over the past decade, social media platforms have penetrated deeply into the mech­anics of everyday life, affecting people's informal interactions, as well as institutional structures and professional routines. Far from being neutral platforms for everyone, social media have changed the conditions and rules of social interaction. In this article, we examine the intricate dynamic between social media platforms, mass media, users, and social institutions by calling attention to social media logic—the norms, strategies, mechanisms, and economies—underpin­ning its dynamics. This logic will be considered in light of what has been identified as mass me­dia logic, which has helped spread the media's powerful discourse outside its institutional boundaries. Theorizing social media logic, we identify four grounding principles—programmabil­ity, popularity, connectivity, and datafication—and argue that these principles become increas­ingly entangled with mass media logic. The logic of social media, rooted in these grounding principles and strategies, is gradually invading all areas of public life. Besides print news and broadcasting, it also affects law and order, social activism, politics, and so forth. Therefore, its sustaining logic and widespread dissemination deserve to be scrutinized in detail in order to better understand its impact in various domains. Concentrating on the tactics and strategies at work in social media logic, we reassess the constellation of power relationships in which social practices unfold, raising questions such as: How does social media logic modify or enhance ex­isting mass media logic? And how is this new media logic exported beyond the boundaries of (social or mass media proper? The underlying principles, tactics, and strategies may be relat­ively simple to identify, but it is much harder to map the complex connections between plat­forms that distribute this logic: users that employ them, technologies that

  11. 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.

  12. 47 CFR 1.1603 - Conduct of random selection.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Conduct of random selection. 1.1603 Section 1.1603 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1603 Conduct of random selection. The...

  13. 47 CFR 1.1602 - Designation for random selection.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Designation for random selection. 1.1602 Section 1.1602 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Random Selection Procedures for Mass Media Services General Procedures § 1.1602 Designation for random selection...

  14. Media relations after the introduction of social media

    OpenAIRE

    Mesila, Helin

    2010-01-01

    In the light of the popularity of social media on one hand, and the contradictive relationships between journalists and public relations practitioners on the other hand, the thesis studies media relations after the introduction of social media. The study focuses on media relations in Estonian public relations scenery. The research answers to the questions: - What are media relations today? - What are the functions of social media and media relations in organizational communication? ...

  15. Media education and media enlightenment as attributes of information society

    Directory of Open Access Journals (Sweden)

    Лилия Борисовна Белоглазова

    2014-12-01

    Full Text Available The article deals with the problem of the functioning of media-education and media-enlightenment in modern society. Focuses on the impact of this socio-cultural phenomenon on consciousness of members of the Information Society. Are the main characteristics of media-education and media-education and media-enlightenment. Concludes that media-education and media-enlightenment forms unscientific and anti-scientific thinking and style speech.

  16. Organizational Communication and Media

    DEFF Research Database (Denmark)

    Tække, Jesper

      The paper reflects an interest in the relation between organizational communication and media. It tries to answer the question, how we can observe the relationship between organizational communication and media. It is a work-in-progress which tries to combine organizational studies inspired...... of Niklas Luhmann (Tække & Paulsen 2008, Tække 2008a) with analysis of how organizations communicate in and about media. Using systems theory and form theory, it puts forward a theoretical framework and a strategy for analysing organisational communication in and about media. The medium aspect is inspired...... is a possible framework to draw the two disciplines together in, because it is a theory about the relation between the social and the media it is based on. First the paper sum up the Luhmann inspired theory about organizations, fleshing out how organizations are thought to communicate in and about media and how...

  17. Social media visibility

    DEFF Research Database (Denmark)

    Uldam, Julie

    2018-01-01

    of activists remains under-researched. This article examines BP’s surveillance of activists who criticise the company’s corporate social responsibility (CSR) programme as ‘greenwashing’. In this way, it goes beyond corporations’ uses of big data and instead explores how they monitor and discuss strategies......As activists move from alternative media platforms to commercial social media platforms, they face increasing challenges in protecting their online security and privacy. While government surveillance of activists is well-documented in scholarly research and the media, corporate surveillance...... for responding to the activities of individual activists in social media. It shows that while social media afford an unprecedented level of visibility for activists, it comes with the risk of being monitored by corporations. Theoretically, it draws on conceptions of visibility in social sciences and media...

  18. The Media Mixer

    DEFF Research Database (Denmark)

    Vestergaard, Vitus; Mortensen, Christian Hviid

    In recent years many museums have experimented with different approaches to involving users through digital media. We explore how remixing and content sharing can be used as a means for user participation. Remix culture is seen as a culture that allows and encourages the production of derivative...... works; works that are based on already existing works. This cultural practice thrives throughout the Internet, most notably on web2.0 sites like YouTube. The Media Museum has embraced the remix paradigm with the development of an interactive media experience centre called the Media Mixer. Here...... the museum users can produce, deconstruct, reconstruct and finally publish and share digital media content. The media content is created by the user in the museums physical environment, but it can be mixed with material from local or global archives. In that way the gap between the analogue and the digital...

  19. Abortion in the media.

    Science.gov (United States)

    Conti, Jennifer A; Cahill, Erica

    2017-12-01

    To review updates in how abortion care is depicted and analysed though various media outlets: news, television, film, and social media. A surge in recent media-related abortion research has recognized several notable and emerging themes: abortion in the news media is often inappropriately sourced and politically motivated; abortion portrayal in US film and television is frequently misrepresented; and social media has a new and significant role in abortion advocacy. The portrayal of abortion onscreen, in the news, and online through social media has a significant impact on cultural, personal, and political beliefs in the United States. This is an emerging field of research with wide spread potential impact across several arenas: medicine, policy, public health.

  20. Internal Social Media

    DEFF Research Database (Denmark)

    Madsen, Vibeke Thøis

    2018-01-01

    Internal social media is a web-based communication arena that provides all organizational members with a communication opportunity. The media has emerged in organizations since 2004, and is increasingly seen as a way of giving employees a voice in organizations which can benefit the organization...... in terms of knowledge sharing, collaboration, and employee participation and engagement. The first wave of studies of internal social media was primarily from an information-systems perspective and focused more on its adoption, its affordances, and the outcome of its introduction. The second wave...... of studies was more concerned with studying the dynamics of communication on internal social media, in order to understand coworkers as strategic communicators and how communication on internal social media can constitute the organization. With a successful introduction of internal social media, coworkers...

  1. New Media, New Citizens?

    DEFF Research Database (Denmark)

    Ohme, Jakob

    as for different age groups, the thesis shows that digital and especially social media use can be a strong driver of citizen participation. Besides looking at immediate mobilizing effects, the book sheds light on how digital media use may shape participation patterns through a long-term change in citizenship......The use of news media is regarded as a driver for citizens’ engagement with society and their political participation. But as news media use increasingly shifts to digital platforms, it is crucial to understand the interplay between a changing media environment and recent patterns of political...... participation. Against the background of citizens’ diverse possibilities for receiving political information and being politically active nowadays, the book focuses on the impact of digital media on political participation in Denmark. By examining this relationship in election- and non-election times as well...

  2. Orchestrating the Media Collage

    Science.gov (United States)

    Ohler, Jason

    2009-01-01

    Modern literacy has always meant being able to both read and write narrative in the media forms of the day, whatever they may be. Just being able to read is not sufficient. A new dimension of literacy is now in play--namely, the ability to adapt to new media forms and fit them into the overall media collage quickly and effectively. A strong case…

  3. The digital media handbook

    CERN Document Server

    Dewdney, Andrew

    2013-01-01

    The new edition of The Digital Media Handbook presents an essential guide to the historical and theoretical development of digital media, emphasising cultural continuity alongside technological change, and highlighting the emergence of new forms of communication in contemporary networked culture.Andrew Dewdney and Peter Ride present detailed critical commentary and descriptive historical accounts, as well as a series of interviews from a range of digital media practitioners, including producers, developers, curators and artists.The Digital Media Handbook highlights key concerns of today's prac

  4. Media Monopoly in Brazil.

    Science.gov (United States)

    Amaral, Roberto; Guimaraes, Cesar

    1994-01-01

    Documents the process of broadcasting media development in Brazil, the failure of new technologies to produce democratization, and the barriers to democratization erected by monopolization and "metastasis." (SR)

  5. Overview: new media.

    Science.gov (United States)

    O'Keeffe, Gwenn Schurgin

    2012-06-01

    Pediatricians care for children's growth and development from the time they are born until they become adults. In addition, pediatricians must be vigilant for external influences. Technology influences children of all ages. Seventy-five percent of teenagers own cell phones, with 25% using them for social media. Technology can lead to an increase in skills and social benefits but there is also the potential for harm such as sexting, cyberbullying, privacy issues, and Internet addiction, all of which can affect health. Pediatricians must become well versed in the new media to provide media-oriented anticipatory guidance and advice on media-related issues. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Antennas in inhomogeneous media

    CERN Document Server

    Galejs, Janis; Fock, V A; Wait, J R

    2013-01-01

    Antennas in Inhomogeneous Media details the methods of analyzing antennas in such inhomogeneous media. The title covers the complex geometrical configurations along with its variational formulations. The coverage of the text includes various conditions the antennas are subjected to, such as antennas in the interface between two media; antennas in compressible isotropic plasma; and linear antennas in a magnetoionic medium. The selection also covers insulated loops in lossy media; slot antennas with a stratified dielectric or isotropic plasma layers; and cavity-backed slot antennas. The book wil

  7. Media multitasking in adolescence.

    Science.gov (United States)

    Cain, Matthew S; Leonard, Julia A; Gabrieli, John D E; Finn, Amy S

    2016-12-01

    Media use has been on the rise in adolescents overall, and in particular, the amount of media multitasking-multiple media consumed simultaneously, such as having a text message conversation while watching TV-has been increasing. In adults, heavy media multitasking has been linked with poorer performance on a number of laboratory measures of cognition, but no relationship has yet been established between media-multitasking behavior and real-world outcomes. Examining individual differences across a group of adolescents, we found that more frequent media multitasking in daily life was associated with poorer performance on statewide standardized achievement tests of math and English in the classroom, poorer performance on behavioral measures of executive function (working memory capacity) in the laboratory, and traits of greater impulsivity and lesser growth mindset. Greater media multitasking had a relatively circumscribed set of associations, and was not related to behavioral measures of cognitive processing speed, implicit learning, or manual dexterity, or to traits of grit and conscientiousness. Thus, individual differences in adolescent media multitasking were related to specific differences in executive function and in performance on real-world academic achievement measures: More media multitasking was associated with poorer executive function ability, worse academic achievement, and a reduced growth mindset.

  8. Open Media Science

    DEFF Research Database (Denmark)

    Møller Moltke Martiny, Kristian; Pedersen, David Budtz; Hansted, Allan Alfred Birkegaard

    2016-01-01

    In this article, we present three challenges to the emerging Open Science (OS) movement: the challenge of communication, collaboration and cultivation of scientific research. We argue that to address these challenges OS needs to include other forms of data than what can be captured in a text...... and extend into a fully-fledged Open Media movement engaging with new media and non-traditional formats of science communication. We discuss two cases where experiments with open media have driven new collaborations between scientists and documentarists. We use the cases to illustrate different advantages...... of using open media to face the challenges of OS....

  9. Making Media Studies

    Directory of Open Access Journals (Sweden)

    David Gauntlett

    2015-12-01

    Full Text Available This podcast is a recording of a research seminar that took place on December 3, 2015, at the University of Westminster's Communication and Media Research Institute (CAMRI. In this contribution, David Gauntlett discusses his new book, Making Media Studies, and other new work. In Making Media Studies (Peter Lang, 2015, Gauntlett proposes a vision of media studies based around doing and making – not about the acquisition of skills, as such, but an experience of building knowledge and understanding through creative hands-on engagement with all kinds of media. Gauntlett suggests that media studies scholars have failed to recognise the significance of everyday creativity – the vital drive of people to make, exchange, and learn together, supported by online networks. He argues that we should think about media in terms of conversations, inspirations, and making things happen. Media studies can be about genuine social change, he suggests, if we recognise the significance of everyday creativity, work to transform our tools, and learn to use them wisely. David Gauntlett is a Professor in the School of Media, Arts and Design at the University of Westminster, where he is also the School's Co-Director of Research. He is the author of several books, including: Creative Explorations (2007, Media, Gender and Identity: An Introduction (2nd edition 2008, Making is Connecting (2011, and Making Media Studies (2015. He has made a number of popular online resources, videos and playthings, and has pioneered creative research and workshop methods. He is external examiner for Information Experience Design at the Royal College of Art, London.

  10. Educational Potential of New Media

    Directory of Open Access Journals (Sweden)

    Maria Yu. Kazak

    2017-11-01

    Full Text Available Digitalization of the mass media, which has radically changed the information environment, creates new opportunities for self-education and upgrowth of the audience. The paper defines the communicative and cultural status of new media, characterizes the socio-cultural and technological aspects of their dynamics; substantiates the necessity of elaborating mechanisms for systematization of heterogeneous information flows and elaborating criteria for their evaluation in the era of globalization of the media sphere, what implies a qualitatively different level of media competence of the audience, provided with such factors as media education, media coverage, media criticism. The definition of concepts "media competence", "media enlightenment", "media education", "media criticism" is given and their functional areas are delineated. Social networks are considered as an important tool for media enlightenment which provides significant opportunities for promoting cultural achievements in the new media environment.

  11. Effects of reactive oxygen species levels in prepared culture media on embryo development: a comparison of two media.

    Science.gov (United States)

    Shih, Ying-Fu; Lee, Tsung-Hsien; Liu, Chung-Hsien; Tsao, Hui-Mei; Huang, Chun-Chia; Lee, Maw-Sheng

    2014-12-01

    This study determined the correlation between the levels of reactive oxygen species (ROS) in prepared culture media and the early development of human embryos. This was an autocontrolled comparison study. A total of 159 patients undergoing in vitro fertilization/intracytoplasmic sperm injection treatment were recruited in this study. The pH values, osmolarity pressures, and ROS levels of 15 batches of two culture media were measured. Sibling oocytes or embryos from individual patients were randomly assigned to two culture groups with Quinn's Advantage Cleavage and Blastocyst media (QAC/QAB) or GIII series cleavage and blastocyst media (G1.3/G2.3). The difference between the two culture groups was analyzed using one-sample t test. The QAC/QAB and G1.3/G2.3 media exhibited similar pH values and osmolarity pressures. However, the prepared QAC/QAB media were characterized to contain lower amounts of ROS than the G1.3/G2.3 media. Furthermore, the blastocysts that developed under the QAC/QAB media were morphologically superior to those that developed under the G1.3/G2.3 media. The elevated ROS levels in culture media were associated with poor development of blastocyst-stage embryos. Measurement of ROS levels may be a valuable process for medium selection or modification. Copyright © 2014. Published by Elsevier B.V.

  12. Media Anthropology: A Theoretical Framework

    Science.gov (United States)

    Eiselein, E. B.; Topper, Martin

    1976-01-01

    Media anthropology, a diverse field, has involved nearly all the major subdisciplines of anthropology and most of the major media in five different areas of interaction: the study of media, reaching the public, gathering data, teaching with media, and applied media anthropology. (NQ)

  13. Diffusion of oriented particles in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Haber, René [Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Centre for Nonlinear Studies, Institute of Cybernetics at Tallinn University of Technology, Akadeemia tee 21, 12618 Tallinn (Estonia); Prehl, Janett [Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Herrmann, Heiko [Centre for Nonlinear Studies, Institute of Cybernetics at Tallinn University of Technology, Akadeemia tee 21, 12618 Tallinn (Estonia); Hoffmann, Karl Heinz, E-mail: hoffmann@physik.tu-chemnitz.de [Institut für Physik, Technische Universität Chemnitz, D-09107 Chemnitz (Germany)

    2013-11-29

    Diffusion of particles in porous media often shows subdiffusive behavior. Here, we analyze the dynamics of particles exhibiting an orientation. The features we focus on are geometrical restrictions and the dynamical consequences of the interactions between the local surrounding structure and the particle orientation. This interaction can lead to particles getting temporarily stuck in parts of the structure. Modeling this interaction by a particular random walk dynamics on fractal structures we find that the random walk dimension is not affected while the diffusion constant shows a variety of interesting and surprising features.

  14. Diffusion of oriented particles in porous media

    International Nuclear Information System (INIS)

    Haber, René; Prehl, Janett; Herrmann, Heiko; Hoffmann, Karl Heinz

    2013-01-01

    Diffusion of particles in porous media often shows subdiffusive behavior. Here, we analyze the dynamics of particles exhibiting an orientation. The features we focus on are geometrical restrictions and the dynamical consequences of the interactions between the local surrounding structure and the particle orientation. This interaction can lead to particles getting temporarily stuck in parts of the structure. Modeling this interaction by a particular random walk dynamics on fractal structures we find that the random walk dimension is not affected while the diffusion constant shows a variety of interesting and surprising features.

  15. Japanese Media in English.

    Science.gov (United States)

    Tanaka, Sachiko Oda

    1995-01-01

    Describes the use of English in the media in Japan, focusing on the role and history of English-language newspapers, radio, and television programs, as well as the proliferation of English-language films shown in Japanese cinemas. Discusses the implications of English in the Japanese media. (20 references) (MDM)

  16. Advertising Pressures on Media.

    Science.gov (United States)

    Hammitt, Harry

    The majority of the media in the United States is funded through revenues derived from the sale of advertising space. The problem that arises from this situation is fundamentally an economic one: if advertisers are paying the bills for the media, how much control over content should they have? This report offers a review of instances in which…

  17. Corporeal-Locomotive Media

    DEFF Research Database (Denmark)

    Nørgård, Rikke Toft

    and experiences such as reading or listening to a story and watching a movie or theatre play and other traditional or new media forms. These circumstances make the article question whether digital games can be understood as (new) media form at all and, thus, it points towards a possible new vocabulary...... for and comprehension of digital games, gameplay and gameplayers....

  18. A Religious Media Revolution?

    DEFF Research Database (Denmark)

    Skovgaard-Petersen, Jakob

    2016-01-01

    This article is a preliminary survey of the media usage of Sunni religious actors during the Syrian conflict. It traces the adoption of new media by religious actors, and analyses the kind of authority these actors have sought to embody, whether regime supporting, oppositional or jihadist...

  19. Loneliness and Media Gratifications.

    Science.gov (United States)

    Canary, Daniel J.; Spitzberg, Brian H.

    1993-01-01

    Assesses the nature of the relationship between experienced loneliness and media gratifications. Finds that chronically lonely college students rely less on media for escape than do others and that they reported the least motivation for watching their favorite soap opera. (SR)

  20. Media Entertainment and emotions

    DEFF Research Database (Denmark)

    Tan, Ed S.

    2017-01-01

    The chapter presents a psychological framework for entertainment experiences. It reviews types of emotion and their associations with media entertainment contents, explaining the role of genre.......The chapter presents a psychological framework for entertainment experiences. It reviews types of emotion and their associations with media entertainment contents, explaining the role of genre....

  1. Men, Myth, and Media.

    Science.gov (United States)

    Thoman, Elizabeth, Ed.; Silver, Rosalind, Ed.

    1989-01-01

    This issue on gender and the media contains the following (1) "Home, Home on the Remote"; (2) "Dads Through the Decades" (Mark Crispin Miller); (3) "The New Man: That's Entertainment!" (John Lehrer); (4) "Singing Men's Songs" (Kerry Skorlich); (5) "Media Myths and Men's Work" (Ian Harris); (6) "Why Are There No Asian Male Anchors?" (Ben…

  2. Austria: Media Dependence.

    Science.gov (United States)

    Signitzer, Benno

    1978-01-01

    Describes the Austrian broadcast industry which is dominated by foreign influences. Suggests the restoration of autonomy of Austria's media through a system of promotion of and subsidies to Austrian media efforts, as well as a decentralization of foreign influence to increase the quality and competitiveness of domestic production. (JMF)

  3. Mapping Media and Meaning

    DEFF Research Database (Denmark)

    Chamberlain, Alan; Bødker, Mads; Papangelis, Konstantinos

    2017-01-01

    places and intangible personal content can be used to develop meaningful experiences. The paper explores the use of autoethnography as a method for soundscape design in the fields of personal heritage and locative media. Specifically, we explore possible connections between digital media, space...

  4. Understanding social media logic

    NARCIS (Netherlands)

    van Dijck, J.; Poell, T.

    2013-01-01

    Over the past decade, social media platforms have penetrated deeply into the mech­anics of everyday life, affecting people's informal interactions, as well as institutional structures and professional routines. Far from being neutral platforms for everyone, social media have changed the conditions

  5. Literacy, Learning, and Media.

    Science.gov (United States)

    Adams, Dennis; Hamm, Mary

    2000-01-01

    Considers the expanding definition of literacy from traditional reading and writing skills to include technological, visual, information, and networking literacy. Discusses the impact of media on social interactions and intellectual development; linking technology to educational goals; influences of new media symbol systems on communication;…

  6. Introduction to Media.

    Science.gov (United States)

    Riler, Robert

    Designed for senior high school students, this one semester course focuses on four aspects of modern media: television, film, radio, and advertising. Each topic is worked into a weekly lesson plan format that stresses the active involvement of students in the learning process. The course outline contains lists of objectives and media materials…

  7. Work in the Media

    NARCIS (Netherlands)

    Deuze, M.

    2014-01-01

    As media have become dominant players in society’s affairs and, as an industry, represent a powerful economic and symbolic force, it is disheartening to see that work across the creative industries is becoming increasingly precarious. At the same time, media practitioners address this precarity in a

  8. Corporate Media Governance

    NARCIS (Netherlands)

    Kempen, Petrus Cornelis

    2011-01-01

    The media can make or break a reputation. This being said, it seems to be essential for companies, governments and institutions to pay specific attention to corporate media management in their daily operations. However, this thesis shows that they often neglect to pay adequate attention to corporate

  9. Building Social Media Connections

    Science.gov (United States)

    Ferriter, William N.; Ramsden, Jason T.; Sheninger, Eric C.

    2012-01-01

    Incorporating social media tools into your professional practices does not have to be intimidating as long as you are willing to tackle five action steps. It is far easier to articulate the strengths--and to imagine the possibilities--of social media spaces as tools for communication and professional development when you are actively using those…

  10. Contrast Media: Are There Differences in Nephrotoxicity among Contrast Media?

    Science.gov (United States)

    2014-01-01

    Iodinated contrast agents are usually classified based upon their osmolality—high, low, and isosmolar. Iodinated contrast agents are also nephrotoxic in some but not all patients resulting in loss of glomerular filtration rate. Over the past 30 years, nephrotoxicity has been linked to osmolality although the precise mechanism underlying such a link has been elusive. Improvements in our understanding of the pathogenesis of nephrotoxicity and prospective randomized clinical trials have attempted to further explore the relationship between osmolality and nephrotoxicity. In this review, the basis for our current understanding that there are little if any differences in nephrotoxic potential between low and isosmolar contrast media will be detailed using data from clinical studies. PMID:24587997

  11. Do universal media literacy programs have an effect on weight and shape concern by influencing media internalization?

    Science.gov (United States)

    Wade, Tracey D; Wilksch, Simon M; Paxton, Susan J; Byrne, Susan M; Austin, S Bryn

    2017-07-01

    The current study examined whether media internalization, found to mediate the relationship between selected prevention programs and outcomes, mediated the impact of two universal prevention programs that targeted risk factors for eating disorders and obesity, namely weight concern, and shape concern. Students randomized to a media literacy (Media Smart) program (N = 269, 65% females, mean age 12.97 years) and a healthy lifestyle (Life Smart) program (N = 347, 69% females, mean age 13.07 years) were included in the analyses. There were four waves of data (baseline, end of intervention, 6- and 12-month follow-up). Latent growth curve modeling was used to explore whether group assignment influenced levels of media internalization, and whether that in turn influenced change over time of our two outcome variables. Being randomly allocated to Media Smart as opposed to Life Smart resulted in less growth of both outcome variables through the influence on decreasing levels of media internalization. Findings provided support for the suggestion that media literacy programs exert an impact on outcomes related to eating disorder risk through changes to media internalization. Future research should examine whether these mechanisms of change differ between girls and boys. © 2017 Wiley Periodicals, Inc.

  12. How Affiliation Disclosure and Control Over User-Generated Comments Affects Consumer Health Knowledge and Behavior: A Randomized Controlled Experiment of Pharmaceutical Direct-to-Consumer Advertising on Social Media.

    Science.gov (United States)

    DeAndrea, David Christopher; Vendemia, Megan Ashley

    2016-07-19

    More people are seeking health information online than ever before and pharmaceutical companies are increasingly marketing their drugs through social media. The aim was to examine two major concerns related to online direct-to-consumer pharmaceutical advertising: (1) how disclosing an affiliation with a pharmaceutical company affects how people respond to drug information produced by both health organizations and online commenters, and (2) how knowledge that health organizations control the display of user-generated comments affects consumer health knowledge and behavior. We conducted a 2×2×2 between-subjects experiment (N=674). All participants viewed an infographic posted to Facebook by a health organization about a prescription allergy drug. Across conditions, the infographic varied in the degree to which the health organization and commenters appeared to be affiliated with a drug manufacturer, and the display of user-generated comments appeared to be controlled. Affiliation disclosure statements on a health organization's Facebook post increased perceptions of an organization-drug manufacturer connection, which reduced trust in the organization (point estimate -0.45, 95% CI -0.69 to -0.24) and other users who posted comments about the drug (point estimate -0.44, 95% CI -0.68 to -0.22). Furthermore, increased perceptions of an organization-manufacturer connection reduced the likelihood that people would recommend the drug to important others (point estimate -0.35, 95% CI -0.59 to -0.15), and share the drug post with others on Facebook (point estimate -0.37, 95% CI -0.64 to -0.16). An affiliation cue next to the commenters' names increased perceptions that the commenters were affiliated with the drug manufacturer, which reduced trust in the comments (point estimate -0.81, 95% CI -1.04 to -0.59), the organization that made the post (point estimate -0.68, 95% CI -0.90 to -0.49), the likelihood of participants recommending the drug (point estimate -0.61, 95% CI -0

  13. Trolling new media: violent extremist groups recruiting through social media

    OpenAIRE

    Chang, Mark D.

    2015-01-01

    Approved for public release; distribution is unlimited With the advent and subsequent growth of several new media technologies, violent extremist groups have incorporated social media into recruiting strategies. How are violent extremist groups using social media for recruiting? This thesis explores several new media technologies—websites, blogs, social media, mobile phones, and online gaming—to determine if violent extremist groups rely on social media for recruiting. By comparing the com...

  14. Komunikasi Krisis di Era New Media dan Social Media

    OpenAIRE

    Prastya, Narayana Mahendra

    2016-01-01

    New media and social media have changed the practice of public relations. One area that changed is crisis communication. Because of these new technologies, crisis can be more complex. The pace of information, the uncertainty, and the rumors, are increasing. Public relations practitioners should include the new media and social media use in their crisis communication plan. Before doing that, public relations practitioners should change their mindset about social media and new media. The first ...

  15. Populism and the media

    DEFF Research Database (Denmark)

    Esser, Frank; Stepinska, Agnieszka; Hopmann, David Nicolas

    2017-01-01

    European media systems have gone through major changes in the last few decades, and these changes have included increased opportunity structures for the dissemination of populist messages. Chapter 12 (‘Switzerland’) rightly states that the disappearance of the traditional party press, increased...... media ownership concentration, dependence on advertising, and a stronger orientation toward news values have worked in favor of a growing populist discourse. The newly established online media are seen as having a high afnity to populism’s rhetorical persuasion because both aim for the “quick kick....../click” with a broad audience. As was stated in Chapter 1 in this volume, the role that the media play in the dissemination of populism is largely under-explored. In the classical research literature dealing with populism (see, e.g., Canovan, 1981; Taggart, 2000), communication and media are not addressed at all. When...

  16. Media Sociography on Weblogs

    DEFF Research Database (Denmark)

    Tække, Jesper

    Weblogs are not only one of the newest technical media for communication, but also one of the most difficult to understand. Are weblogs a kind of mass medium, a personal medium like an online diary, or a medium that gives space for communities to grow? Or are weblogs a medium that enable all...... these possibilities depended on the actual use? This paper throws some light on what weblogs are by using the methodology of Media Sociography (Tække 2003, 2004a, 2004b and 2004c). Media Sociography is a strategy for analysing mediated social systems or in other words a strategy for describing the social in relation...... to the media it is based on. Theoretically seen it is inspired of two theoretical paradigms the Sociological Systems Theory of Niklas Luhmann and the Media Theory (also called the Toronto school). Empirically the paper primary draws on the literature about weblogs, which could be framed as CMC...

  17. Social Media in Organizations

    DEFF Research Database (Denmark)

    Razmerita, Liana; Kirchner, Kathrin; Nabeth, Thierry

    2014-01-01

    By using social media, many companies try to exploit new forms of interaction, collaboration, and knowledge sharing through leveraging the social, collaborative dimension of social software. The traditional collective knowledge management model based on a top-down approach is now opening up new...... avenues for a bottom-up approach incorporating a more personal knowledge management dimension, which could be synergized into collective knowledge using the social-collaborative dimension of social media. This article addresses the following questions: (1) How can social media support the management...... of personal and collective knowledge using a synergetic approach? (2) Do the personal and collective dimensions compete with each other or can they reinforce each other in a more effective manner using social media? Our findings indicate that social media supports both the personal and collective dimensions...

  18. Social Media Reputation

    DEFF Research Database (Denmark)

    Etter, Michael; Colleoni, Elanor; Ravasi, Davide

    directly to corporate performance and actions. Secondly, prominent reputation measurements couple stakeholders´ believes to reputation drivers through the use of predefined scales and items. We argue that with the rise of social media a company´s reputation has increasingly become autonomous from corporate...... actions, which demands a greater decoupling of stakeholders´ perceptions from corporate signals or actions in corporate reputation research. We develop the concept of social media reputation as the overall evaluation of a company presented in social media and present a new approach of measuring reputation...... based on social media data that accounts for the autonomy of stakeholder´s perception of a firm. We compare and contrast this novel social media reputation measure (SMRM) with traditional reputation measurements and find that SMRM is a valuable measurement to capture the autonomy of the stakeholders...

  19. Balancing media environments

    DEFF Research Database (Denmark)

    Olesen, Mogens

    The paper examines how students in Danish upper secondary schools experience the uses and effects of the digital environment in relation to their school activities. Theoretically a media ecological perspective (Strate 2006) is applied which understands teaching and learning practices as shaped...... by the interrelation between teacher, student and the media technologies. According to this perspective, media creates an environment that shapes our possibilities for acting and communicating. In a basic sense, teaching and learning is a communicative situation where, traditionally, the teacher sends information...... to the receiving students through a medium (e.g. speech, blackboard, book or online learning platform). Digital media challenge this situation due to their affordances (Gibson 1979) for interactivity. Affordance has become an increasingly popular term within media studies for describing a complementary...

  20. From media crossing to media mining

    NARCIS (Netherlands)

    de Jong, Franciska M.G.; Piperidis, S.; Cunningham, H.; Tablan, V.

    2006-01-01

    This paper reviews how the concept of Media Crossing has contributed to the advancement of the application domain of information access and explores directions for a future research agenda. These will include themes that could help to broaden the scope and to incorporate the concept of

  1. Social Justice and Media. Media Corner.

    Science.gov (United States)

    Braun, Joseph A., III, Ed.

    1994-01-01

    Contends that the end of slavery, women's suffrage, and the civil rights movement were watershed events of social justice in U.S. history. Provides reviews of two media-based sets of instructional materials that can help students understand the struggle by disenfranchised groups to become full participants in society. (CFR)

  2. Social media modeling and computing

    CERN Document Server

    Hoi, Steven CH; Boll, Susanne; Xu, Dong; Jin, Rong; King, Irwin

    2011-01-01

    Presents contributions from an international selection of preeminent experts in the field Discusses topics on social-media content analysis, and examines social-media system design and analysis Describes emerging applications of social media

  3. Bullying and social media affordances

    OpenAIRE

    Brailas, Alexios

    2016-01-01

    What constitutes a good and sustainabledigital living?Social media literacyCan we talk about social media intelligence?Can we talk about digital intelligence?How bullying is complicated by special social media affordances?

  4. MediaTracker system

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, D. M. (Dana M.); Strittmatter, R. B. (Richard B.); Abeyta, J. D. (Joline D.); Brown, J. (John); Marks, T. (Thomas), Jr.; Martinez, B. J. (Benny J.); Jones, D. B. (Dana Benelli); Hsue, W.

    2004-01-01

    The initial objectives of this effort were to provide a hardware and software platform that can address the requirements for the accountability of classified removable electronic media and vault access logging. The Media Tracker system software assists classified media custodian in managing vault access logging and Media Tracking to prevent the inadvertent violation of rules or policies for the access to a restricted area and the movement and use of tracked items. The MediaTracker system includes the software tools to track and account for high consequence security assets and high value items. The overall benefits include: (1) real-time access to the disposition of all Classified Removable Electronic Media (CREM), (2) streamlined security procedures and requirements, (3) removal of ambiguity and managerial inconsistencies, (4) prevention of incidents that can and should be prevented, (5) alignment with the DOE's initiative to achieve improvements in security and facility operations through technology deployment, and (6) enhanced individual responsibility by providing a consistent method of dealing with daily responsibilities. In response to initiatives to enhance the control of classified removable electronic media (CREM), the Media Tracker software suite was developed, piloted and implemented at the Los Alamos National Laboratory beginning in July 2000. The Media Tracker software suite assists in the accountability and tracking of CREM and other high-value assets. One component of the MediaTracker software suite provides a Laboratory-approved media tracking system. Using commercial touch screen and bar code technology, the MediaTracker (MT) component of the MediaTracker software suite provides an efficient and effective means to meet current Laboratory requirements and provides new-engineered controls to help assure compliance with those requirements. It also establishes a computer infrastructure at vault entrances for vault access logging, and can

  5. MediaTracker system

    International Nuclear Information System (INIS)

    Sandoval, D.M.; Strittmatter, R.B.; Abeyta, J.D.; Brown, J.; Marks, T. Jr.; Martinez, B.J.; Jones, D.B.; Hsue, W.

    2004-01-01

    The initial objectives of this effort were to provide a hardware and software platform that can address the requirements for the accountability of classified removable electronic media and vault access logging. The Media Tracker system software assists classified media custodian in managing vault access logging and Media Tracking to prevent the inadvertent violation of rules or policies for the access to a restricted area and the movement and use of tracked items. The MediaTracker system includes the software tools to track and account for high consequence security assets and high value items. The overall benefits include: (1) real-time access to the disposition of all Classified Removable Electronic Media (CREM), (2) streamlined security procedures and requirements, (3) removal of ambiguity and managerial inconsistencies, (4) prevention of incidents that can and should be prevented, (5) alignment with the DOE's initiative to achieve improvements in security and facility operations through technology deployment, and (6) enhanced individual responsibility by providing a consistent method of dealing with daily responsibilities. In response to initiatives to enhance the control of classified removable electronic media (CREM), the Media Tracker software suite was developed, piloted and implemented at the Los Alamos National Laboratory beginning in July 2000. The Media Tracker software suite assists in the accountability and tracking of CREM and other high-value assets. One component of the MediaTracker software suite provides a Laboratory-approved media tracking system. Using commercial touch screen and bar code technology, the MediaTracker (MT) component of the MediaTracker software suite provides an efficient and effective means to meet current Laboratory requirements and provides new-engineered controls to help assure compliance with those requirements. It also establishes a computer infrastructure at vault entrances for vault access logging, and can accommodate

  6. Social Media Marketing in Russia

    OpenAIRE

    Olgskaya, Kristina

    2017-01-01

    Social media marketing involves the use of social media for connecting with prospective consumers. The study focuses on explaining such notions like social media marketing (SMM), types of SMM, differences between social media and traditional marketing, social media marketing plan, development ways of strategic social media marketing plan and why strategy may fail. This thesis also presents research in Russian social network – Vkontakte, where promotion of Mechanical Engineering programme ...

  7. 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

  8. 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

  9. Radionuclide transport in fractured media

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    1993-01-01

    Until recently, the classical advective-dispersive transport equation was considered to be an adequate model for describing the motion of a solute (e.g. radionuclides) in porous and fractured media. In this model, the dispersion coefficient is either obtained from a microscopic model of the porous medium or by carefully controlled experiments. As a result of such experiments, a large body of data has been accumulated on the dispersivity. Detailed examination of these data has resulted in a curious phenomenon being discovered; namely, that the longitudinal dispersion length is 'scale-dependent'. That is to say the value deduced depends on the 'size' of the experiment, i.e. on the distance over which measurements are made. Several interesting attempts have been made to develop theories which explain this phenomenon, all based on treating the velocity of the water in the porous medium as a spatially random variable, but retaining the advective-dispersive balance equation. In this work we present an entirely new approach to the problem of solute transport in fractured media based upon an analogy with neutron transport. The new method has several advantages over the previous theories and these will be explained below. Results from the new theory are in agreement with experimental trends and do not require any further adjustment to explain the scale-dependent effect

  10. MEDIA SOSIAL DAN PENGEMBANGAN HUBUNGAN INTERPERSONAL REMAJA DI SIDOARJO

    OpenAIRE

    Abadi, Totok Wahyu; Sukmawan, Fandrian; Utari, Dian Asha

    2016-01-01

    The purpose of this study is to analyze and explain the use of social media among teenagers, the development of interpersonal relationships, and the influence of social media on the development of adolescent interpersonal relationships in Sidoarjo. This research, which involves a hundred high school students as the respondents, uses explanative approach. Through random sampling of data collection, the data were analyzed using descriptive statistics analyzing techniques and multiple regression...

  11. CLASSICAL MEDIA RELATIONS AND NEW MEDIA RELATIONS IN SPORT

    Directory of Open Access Journals (Sweden)

    Alexandru Lucian MIHAI

    2014-06-01

    Full Text Available Media relations in sport mean maintenance of networks and positive relationships with people in the media to obtain positive media exposure for a sport product (informal and formal information sessions with media representatives. Because of the pervasive influence the media has on marketing success, sport marketers must make concerted efforts to create a positive relationship between their sport event and the media. They may accomplish this by providing the media with press releases, having news conferences, having media-day events (in which the media are invited to interact with the players, coaches, and administrators, providing media guides for the respective sport events and so on. Each of these activities promotes active involvement from the media, which will subsequently contribute to relationship building with the community.

  12. Social Media and Bullshit

    Directory of Open Access Journals (Sweden)

    Rasmus Kleis Nielsen

    2015-04-01

    Full Text Available To understand the role of social media in society, we have to understand how social media are understood. We need to analyze how different actors and organizations see and think about technology, the forms of knowledge that people draw on as they make sense of, develop, and use social media. Central among these is bullshit. This short essay discusses bullshit as defined by the philosopher Harry Frankfurt as statements made with little or no concern for their truth-value or justification and argues that social media are accompanied by unusually large amounts of bullshit for two reasons. First, they confront us with epistemological problems and are hard to understand. Second, there is a large demand for knowledge about what they mean, a powerful political economy that generates a lot of statements about social media, including substantial amounts of bullshit. Given the rapid development of social media and their growing importance, this is unlikely to change in the near future. Bullshit is here to stay, and we need to take it seriously intellectually and analytically to understand social media.

  13. Media Literacy in Montenegro

    Directory of Open Access Journals (Sweden)

    Jelena Perovic

    2015-12-01

    Full Text Available Few countries in the world have introduced media education into their curriculums. Montenegro became one of them in 2009, when “media literacy” was introduced as an optional subject for 16 and 17 year old students of Gymnasium high schools. This article presents the findings of the first and only research conducted so far on media education in Montenegro. It is a national case study which examines the potential of media education to change the school culture and accelerate education system reform towards embracing the new digital education paradigm in the future. The focus is on the results of research conducted through in-depth interviews with media literacy teachers all over the country. Despite the many challenges, all teachers identify the potential of media education to strengthen some of the key competences of the students and to improve their motivation and academic performance. They also identify potential to change positively school culture by transforming teachers into “cultural mediators” (Morcellini, 2007 and by supporting the formation of a “participative culture” (Jenkins & Kelley, 2013 in schools. This research recommends focusing education reform on spreading the media education pedagogy to the entire curriculum in order to embrace the new digital education paradigm in the future.

  14. Mass media influence spreading in social networks with community structure

    Science.gov (United States)

    Candia, Julián; Mazzitello, Karina I.

    2008-07-01

    We study an extension of Axelrod's model for social influence, in which cultural drift is represented as random perturbations, while mass media are introduced by means of an external field. In this scenario, we investigate how the modular structure of social networks affects the propagation of mass media messages across a society. The community structure of social networks is represented by coupled random networks, in which two random graphs are connected by intercommunity links. Considering inhomogeneous mass media fields, we study the conditions for successful message spreading and find a novel phase diagram in the multidimensional parameter space. These findings show that social modularity effects are of paramount importance for designing successful, cost-effective advertising campaigns.

  15. Turkish Press in Social Media

    OpenAIRE

    AYTEN, Adem

    2013-01-01

    Social media, is one of the most researched facts today by the commications fellows. To get in use by Web 2.0 social media becomes common due to the rise of using mobile technologies. Instead of competing with traditional media and being an alternative media, social media is a new media that traditional media can transfer its content to it and can benefit its advantages. Indeed,the traditional media carried its content to the websites to access of their readers/listeners/watchers to compete ...

  16. Media multitasking and implicit learning.

    Science.gov (United States)

    Edwards, Kathleen S; Shin, Myoungju

    2017-07-01

    Media multitasking refers to the simultaneous use of different forms of media. Previous research comparing heavy media multitaskers and light media multitaskers suggests that heavy media multitaskers have a broader scope of attention. The present study explored whether these differences in attentional scope would lead to a greater degree of implicit learning for heavy media multitaskers. The study also examined whether media multitasking behaviour is associated with differences in visual working memory, and whether visual working memory differentially affects the ability to process contextual information. In addition to comparing extreme groups (heavy and light media multitaskers) the study included analysis of people who media multitask in moderation (intermediate media multitaskers). Ninety-four participants were divided into groups based on responses to the media use questionnaire, and completed the contextual cueing and n-back tasks. Results indicated that the speed at which implicit learning occurred was slower in heavy media multitaskers relative to both light and intermediate media multitaskers. There was no relationship between working memory performance and media multitasking group, and no relationship between working memory and implicit learning. There was also no evidence for superior performance of intermediate media multitaskers. A deficit in implicit learning observed in heavy media multitaskers is consistent with previous literature, which suggests that heavy media multitaskers perform more poorly than light media multitaskers in attentional tasks due to their wider attentional scope.

  17. Ethics and social media.

    Science.gov (United States)

    Milton, Constance L

    2014-10-01

    Nurses' use of social media has increased significantly with growing numbers of media-sharing opportunities, platforms, and emerging forms of electronic applications. With the proliferation, opportunities and limitations surface regarding the responsibilities and accountability that nurses have in choosing technology applications with an embedded philosophical ethos that is consistent with the discipline's societal mandate of serving humankind in ways that honor human dignity. This article begins a discussion addressing possible disciplinary obligations and responsibilities for the implementation of social media platforms and possible implications for its future use in the discipline of nursing. © The Author(s) 2014.

  18. Media and ICT

    DEFF Research Database (Denmark)

    Media and information and communication technologies (ICTs) have in the past decades been placed firmly on the educational agenda, and will continue to maintain this position, not least as catalysts for educational change. This issue is reflected in the anthology as it aims to respond...... to the question of how the presence of media and ICT in and outside schools both change and qualify educational practice as well as how the cooperation between media, cultures, aesthetics and social relations affect and support new demands on education. The book represents different academic perspectives...

  19. Open Media Science

    DEFF Research Database (Denmark)

    Møller Moltke Martiny, Kristian; Pedersen, David Budtz; Hansted, Allan Alfred Birkegaard

    2016-01-01

    In this article, we present three challenges to the emerging Open Science (OS) movement: the challenge of communication, collaboration and cultivation of scientific research. We argue that to address these challenges OS needs to include other forms of data than what can be captured in a text...... and extend into a fully-fledged Open Media movement engaging with new media and non-traditional formats of science communication. We discuss two cases where experiments with open media have driven new collaborations between scientists and documentarists. We use the cases to illustrate different advantages...

  20. 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...

  1. 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...

  2. 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...

  3. 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.)

  4. 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.)

  5. 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.

  6. Homogenization of discrete media

    International Nuclear Information System (INIS)

    Pradel, F.; Sab, K.

    1998-01-01

    Material such as granular media, beam assembly are easily seen as discrete media. They look like geometrical points linked together thanks to energetic expressions. Our purpose is to extend discrete kinematics to the one of an equivalent continuous material. First we explain how we build the localisation tool for periodic materials according to estimated continuum medium type (classical Cauchy, and Cosserat media). Once the bridge built between discrete and continuum media, we exhibit its application over two bidimensional beam assembly structures : the honey comb and a structural reinforced variation. The new behavior is then applied for the simple plan shear problem in a Cosserat continuum and compared with the real discrete solution. By the mean of this example, we establish the agreement of our new model with real structures. The exposed method has a longer range than mechanics and can be applied to every discrete problems like electromagnetism in which relationship between geometrical points can be summed up by an energetic function. (orig.)

  7. Spotlight on the media

    CERN Multimedia

    2007-01-01

    Do you want to know more about how the media works, how to deal with journalists? How to maximise opportunity and minimise threat? Then please join us on 22 November. This session will cover how to work effectively with the media, including print, radio and TV. You’ll get an insight into how journalists and news rooms operate. You’ll learn to recognise both soft balls and traps - and develop the techniques for dealing with them. The challenges of explaining CERN to any media outlet will be dealt with too. This interactive presentation, given by Jessica Pryce-Jones, Managing Director of the consultancy firm iOpener Ltd, and Nisha Pillai, news anchor for BBC World, will be illustrated with various case studies. How to deal with the media: maximising opportunity and minimising threat Thursday 22 November, from 4.30 pm, Main Auditorium, Bldg. 500 Coffee break before the event at 4.00 pm

  8. Technetium Sorption Media Review

    International Nuclear Information System (INIS)

    Duncan, J.B.; Kelly, S.E.; Robbins, R.A.; Adams, R.D.; Thorson, M.A.; Haass, C.C.

    2011-01-01

    This report presents information and references to aid in the selection of 99Tc sorption media for feasibility studies regarding the removal of 99Tc from Hanford's low activity waste. The report contains literature search material for sorption media (including ion exchange media) for the most tested media to date, including SuperLig 639, Reillex HPQ, TAM (Kruion), Purolite A520E and A530E, and Dowex 1X8. The U.S. Department of Energy (DOE), Office of River Protection (ORP) is responsible for management and completion of the River Protection Project (RPP) mission, which comprises both the Hanford Site tank farms and the Waste Treatment and Immobilization Plant (WTP). The RPP mission is to store, retrieve and treat Hanford's tank waste; store and dispose of treated wastes; and close the tank farm waste management areas and treatment facilities in a safe, environmentally compliant, cost-effective and energy-effective manner.

  9. New Media as Software

    Directory of Open Access Journals (Sweden)

    Manuel Portela

    2014-03-01

    Full Text Available Review of Lev Manovich, Software Takes Command: Extending the Language of New Media. London: Bloomsbury, 2013, 358 pp. ISBN 978-1-6235-6817-7. In Lev Manovich’s most recent book, this programmatic interrogation of our medial condition leads to the following question: do media still exist after software? This is the question that triggers Manovich’s dialogue both with computing history and with theories of digital media of recent decades, including the extension of his own previous formulations in The Language of New Media, published in 2001, and which became a major reference work in the field. The subtitle of the new book points precisely to this critical revisiting of his earlier work in the context of ubiquitous computing and accelerated transcoding of social, cultural and artistic practices by software.

  10. Creative Digital Media Practices

    DEFF Research Database (Denmark)

    Frølunde, Lisbeth

    , 2006, 2009), machinima (machine + cinema + anime, real-time animation captured in games etc.), and the digital storytelling movement. A dialogic perspective on the diversity of digital media practices opens up for understanding the complex evolution of language on socio-historical, cultural......The presentation reviews the interplay of dialogic (Bakhtin, 1981) and multimodal theories on media production practices, with attention to visual communication (Kress and van Leeuwen, 2001, 2006). This theoretical approach aids in reflecting on digital media practices as novel (new) sign systems...... develop a collaborative digital storytelling showcase for their own digital stories about Roskilde University. This course is intended to bring up reflections on the wider phenomenon of contemporary media practices, such as: YouTube, DIY (do-it-yourself) filmmaking or homemade, garage cinema (Jenkins...

  11. Stochastic porous media equations

    CERN Document Server

    Barbu, Viorel; Röckner, Michael

    2016-01-01

    Focusing on stochastic porous media equations, this book places an emphasis on existence theorems, asymptotic behavior and ergodic properties of the associated transition semigroup. Stochastic perturbations of the porous media equation have reviously been considered by physicists, but rigorous mathematical existence results have only recently been found. The porous media equation models a number of different physical phenomena, including the flow of an ideal gas and the diffusion of a compressible fluid through porous media, and also thermal propagation in plasma and plasma radiation. Another important application is to a model of the standard self-organized criticality process, called the "sand-pile model" or the "Bak-Tang-Wiesenfeld model". The book will be of interest to PhD students and researchers in mathematics, physics and biology.

  12. Terrorism as Media Event

    Directory of Open Access Journals (Sweden)

    2012-07-01

    Full Text Available Proving that terrorism should be seen as a media event (as defined by Dayan and Katzafter 9/11 and treated accordingly. We have turned to the work of Dayan and Katz and GeorgeGerbner’s for a definition of media events and of violence in the mass media. This paper is ahermeneutical interpretation of the concept of terrorism and its relation to communication. We haveput forward a better understanding of the complex concept of terrorism and its definitions in the massmedia context. Terrorism nowadays should always be defined within its inherent relation with themedia. The article is the first to define terrorism as media evenit in Dayan and Katz’s terms.

  13. TECHNETIUM SORPTION MEDIA REVIEW

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN JB; KELLY SE; ROBBINS RA; ADAMS RD; THORSON MA; HAASS CC

    2011-08-25

    This report presents information and references to aid in the selection of 99Tc sorption media for feasibility studies regarding the removal of 99Tc from Hanford's low activity waste. The report contains literature search material for sorption media (including ion exchange media) for the most tested media to date, including SuperLig 639, Reillex HPQ, TAM (Kruion), Purolite A520E and A530E, and Dowex 1X8. The U.S. Department of Energy (DOE), Office of River Protection (ORP) is responsible for management and completion of the River Protection Project (RPP) mission, which comprises both the Hanford Site tank farms and the Waste Treatment and Immobilization Plant (WTP). The RPP mission is to store, retrieve and treat Hanford's tank waste; store and dispose of treated wastes; and close the tank farm waste management areas and treatment facilities in a safe, environmentally compliant, cost-effective and energy-effective manner.

  14. Media, journalism, objectivity

    Directory of Open Access Journals (Sweden)

    Vlajki Emil

    2013-01-01

    Full Text Available This is the text around the themes: Media and Journalism, are confronted two directions of opinions: humanism and elitism. Humanism believes that media and journalism must be metaphysically objective: able to tell the truth regardless of time, place and terms of events. Another approach, elitism, is connected with Hegel's philosophy of history. Hegel's conceptual apparatus includes: Idea, History dialectic, 'cunning mind,' self- development and self-realization. In this context, media and journalism are considered as organic unity, an inseparable part of some dialectical totality. More specifically media and journalism can be objective only if they defend concrete ideological assumptions of society to which they belong. Any other understanding of these two concepts is non-objective, mere moralizing and / or demagoguery.

  15. Media and manipulation

    Directory of Open Access Journals (Sweden)

    Kovačević Braco

    2013-01-01

    Full Text Available The role and importance of the media are huge, both in everyday life and in cultural, spiritual and political life of modern man. Their power in the sense of political shaping of people and shaping of public opinion is very distinctive. In the process of propaganda to influence public opinion, they use various manipulative procedures in order to accomplish certain interests and objectives. Through the media, politics realizes its economic, ideological, political and even military activities. The war in the former Yugoslavia and former Bosnia and Herzegovina was also waged through the media. This media war still is spreading the hate speech, thus still causing conflicts and disintegration processes in the Balkans.

  16. Media and Security Team

    Data.gov (United States)

    Federal Laboratory Consortium — The Media And Security Team led by Prof. Min Wu was established in Fall 2001 at University of Maryland, College Park. A number of research and education activities...

  17. Social Media Policies

    DEFF Research Database (Denmark)

    Stohl, Cynthia; Etter, Michael; Banghart, Scott

    2017-01-01

    of these trends is examined through a content analysis of 112 publicly available social media policies from the largest corporations in the world. The extent to which social media policies facilitate and/or constrain the communicative sensibilities and values associated with contemporary notions of CSR...... negotiation and participation in the social responsibilities of corporations. Moreover, policies generally enact organizational communication practices that are contrary to international CSR guidelines (e.g., the UN Global Compact and other international agreements). Findings suggest that social media...... policies represent a relatively unrecognized development in the institutionalization of CSR communicative norms and practices that call into question the promising affordances of social media for the inclusion of various voices in the public negotiation of what constitutes corporate social responsibility....

  18. Social Media and Teaching

    DEFF Research Database (Denmark)

    Tække, Jesper; Paulsen, Michael

    New research in the Danish upper secondary schools shows that social media like Facebook is the number one attention diverts from the interaction about educational subjects in the classroom. At the same time international research shows that there is a great potential in using social media....... The overriding purpose of the paper is to provide a research-based input to the discussion about the role of social media in schools....... the past seven years (Paulsen & Tække 2009, 2010; Tække & Paulsen 2010). To find out if and how the gap can be reduced, we have initiated the action research project The Socio Media Education Experiment, and in the paper we explain both the background for the project and its preliminary results...

  19. Consolidating Social Media Strategies

    DEFF Research Database (Denmark)

    Gyimóthy, Szilvia; Munar, Ana Maria; Larson, Mia

    2014-01-01

    This study revisits and integrates the insights of recent studies on emergent social media strategies deployed by destination and event management organisations. In a comparative analysis Munar (2012) identified four generic approaches pursued by national tourism boards in the Nordic region, while...... Gyimóthy & Larson (2014) portrayed three digital value co-creation strategies deployed by festival social media. Both frameworks provided novel analytical typologies which identified a series of categories (mimetic, analytic, immersion, advertising and insourcing, crowdsourcing and community consolidation......). This paper discusses the complementary nature of these conceptual proposals and advances an integrated conceptual framework of social media strategies. Based on the empirical findings of a case study that revisits evolving digital and social media strategies of European DMOs this paper maps the dynamics...

  20. Media studies for scientists

    CERN Multimedia

    2002-01-01

    "Science, with its inherent uncertainties, can be hard to put across to the public. But blaming 'sloppy' journalism is too easy. If researchers are to make their points effectively, they should learn more about how the media work" (1 page).

  1. The News Media Industry

    National Research Council Canada - National Science Library

    Bartlett, Charlie

    2003-01-01

    American news media has two fundamental roles in our democracy: that of eyewitness, giving citizens critical information, and also as the watchdog, providing another arm of "checks and balances" within our governmental system...

  2. Communications and media services

    Science.gov (United States)

    Mcculla, James W.; Kukowski, James F.

    1990-01-01

    NASA's internal and external communication methods are reviewed. NASA information services for the media, for the public, and for employees are discussed. Consideration is given to electron information distribution, the NASA TV-audio system, the NASA broadcast news service, astronaut appearances, technology and information exhibits, speaker services, and NASA news reports for internal communications. Also, the NASA worldwide electronic mail network is described and trends for future NASA communications and media services are outlined.

  3. Drupal 7 media

    CERN Document Server

    Tal, Liran

    2013-01-01

    This is a practical, hands-on guide packed with examples that will help you build rich Drupal 7 media web applications.If you are a Drupal site builder and you wish to spice up your web applications with rich media content, then this book is for you. A basic understanding of HTML, JavaScript, and basic PHP module development in Drupal would be helpful, but is not necessary.

  4. Chernobyl and the media

    Energy Technology Data Exchange (ETDEWEB)

    Dibdin, T.

    The way the media reported the Chernobyl nuclear reactor accident was discussed at a day seminar in Birmingham in July. Contributors were from the Forsmark nuclear power station in Sweden where the disaster was first noticed, the International Atomic Energy Agency, the Russian film industry, French TV and SCRAM. Personal experiences and opinions of Chernobyl and the media were discussed. The approach in West Germany, France, Finland and the United Kingdom is compared.

  5. Chernobyl and the media

    International Nuclear Information System (INIS)

    Dibdin, T.

    1987-01-01

    The way the media reported the Chernobyl nuclear reactor accident was discussed at a day seminar in Birmingham in July. Contributors were from the Forsmark nuclear power station in Sweden where the disaster was first noticed, the International Atomic Energy Agency, the Russian film industry, French TV and SCRAM. Personal experiences and opinions of Chernobyl and the media were discussed. The approach in West Germany, France, Finland and the United Kingdom is compared. (UK)

  6. Digital Media Ethics

    DEFF Research Database (Denmark)

    Ess, Charles

    Provides a philosophical-ethical "toolkit" for analyzing central ethical issues evoked by our use of new media, including privacy, copyright, violent and sexual content online, and cross-cultural communication online.......Provides a philosophical-ethical "toolkit" for analyzing central ethical issues evoked by our use of new media, including privacy, copyright, violent and sexual content online, and cross-cultural communication online....

  7. Social Media Cocreation Strategies

    DEFF Research Database (Denmark)

    Gyimóthy, Szilvia; Larson, Mia

    2015-01-01

    This paper explores how social media becomes a part of integrated marketing communications of festival organizations. The purpose of this paper is to conceptualize the co-creation of festival experiences online by comparing managerial strategies and communicative patterns of three large....... Based on the empirical findings, we propose an analytical framework to improve our understanding of the management of social media communications, offering three distinct value co-creation strategies in a festival context....

  8. Percolation in Heterogeneous Media

    International Nuclear Information System (INIS)

    Vocka, Radim

    1999-01-01

    This work is a theoretical reflection on the problematic of the modeling of heterogeneous media, that is on the way of their simple representation conserving their characteristic features. Two particular problems are addressed in this thesis. Firstly, we study the transport in porous media, that is in a heterogeneous media which structure is quenched. A pore space is represented in a simple way - a pore is symbolized as a tube of a given length and a given diameter. The fact that the correlations in the distribution of pore sizes are taken into account by a construction of a hierarchical network makes possible the modeling of porous media with a porosity distributed over several length scales. The transport in the hierarchical network shows qualitatively different phenomena from those observed in simpler models. A comparison of numerical results with experimental data shows that the hierarchical network gives a good qualitative representation of the structure of real porous media. Secondly, we study a problem of the transport in a heterogeneous media which structure is evolving during the time. The models where the evolution of the structure is not influenced by the transport are studied in detail. These models present a phase transition of the same nature as that observed on the percolation networks. We propose a new theoretical description of this transition, and we express critical exponents describing the evolution of the conductivity as a function of fundamental exponents of percolation theory. (author) [fr

  9. Media, risk and science

    CERN Document Server

    Allan, Stuart

    2002-01-01

    How is science represented by the media? Who defines what counts as a risk, threat or hazard, and why? In what ways do media images of science shape public perceptions? What can cultural and media studies tell us about current scientific controversies? "Media, Risk and Science" is an exciting exploration into an array of important issues, providing a much needed framework for understanding key debates on how the media represent science and risk. In a highly effective way, Stuart Allan weaves together insights from multiple strands of research across diverse disciplines. Among the themes he examines are: the role of science in science fiction, such as "Star Trek"; the problem of 'pseudo-science' in "The X-Files"; and how science is displayed in science museums. Science journalism receives particular attention, with the processes by which science is made 'newsworthy' unravelled for careful scrutiny. The book also includes individual chapters devoted to how the media portray environmental risks, HIV-AIDS, food s...

  10. Optical Interactions at Randomly Rough Surfaces

    Science.gov (United States)

    2003-03-10

    Waves Random Media 7, 479 ~1997!. 13 M. Nieto-Vesperinas, Scattering and Diffraction in Physical Op- tics ~John Wiley and Sons, Inc., New York, 1991...Fısica Aplicada, Centro de InÕestigacion Cientıfica y de Educacion Superior de Ensenada, Apartado Postal 2732,´ ´ ´ ´ ´ Ensenada, Baja California

  11. 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

    generation of a stationary near-Gaussian beam with a narrow spectrum. A random distributed feedback fibre laser has efficiency and performance that are comparable to and even exceed those of similar conventional fibre lasers. The key features of the generated radiation of random distributed feedback fibre lasers include: a stationary narrow-band continuous modeless spectrum that is free of mode competition, nonlinear power broadening, and an output beam with a Gaussian profile in the fundamental transverse mode (generated both in single mode and multi-mode fibres). This review presents the current status of research in the field of random fibre lasers and shows their potential and perspectives. We start with an introductory overview of conventional distributed feedback lasers and traditional random lasers to set the stage for discussion of random fibre lasers. We then present a theoretical analysis and experimental studies of various random fibre laser configurations, including widely tunable, multi-wavelength, narrow-band generation, and random fibre lasers operating in different spectral bands in the 1–1.6 μm range. Then we discuss existing and future applications of random fibre lasers, including telecommunication and distributed long reach sensor systems. A theoretical description of random lasers is very challenging and is strongly linked with the theory of disordered systems and kinetic theory. We outline two key models governing the generation of random fibre lasers: the average power balance model and the nonlinear Schrödinger equation based model. Recently invented random distributed feedback fibre lasers represent a new and exciting field of research that brings together such diverse areas of science as laser physics, the theory of disordered systems, fibre optics and nonlinear science. Stable random generation in optical fibre opens up new possibilities for research on wave transport and localization in disordered media. We hope that this review will provide

  12. 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

    generation of a stationary near-Gaussian beam with a narrow spectrum. A random distributed feedback fibre laser has efficiency and performance that are comparable to and even exceed those of similar conventional fibre lasers. The key features of the generated radiation of random distributed feedback fibre lasers include: a stationary narrow-band continuous modeless spectrum that is free of mode competition, nonlinear power broadening, and an output beam with a Gaussian profile in the fundamental transverse mode (generated both in single mode and multi-mode fibres). This review presents the current status of research in the field of random fibre lasers and shows their potential and perspectives. We start with an introductory overview of conventional distributed feedback lasers and traditional random lasers to set the stage for discussion of random fibre lasers. We then present a theoretical analysis and experimental studies of various random fibre laser configurations, including widely tunable, multi-wavelength, narrow-band generation, and random fibre lasers operating in different spectral bands in the 1–1.6 μm range. Then we discuss existing and future applications of random fibre lasers, including telecommunication and distributed long reach sensor systems. A theoretical description of random lasers is very challenging and is strongly linked with the theory of disordered systems and kinetic theory. We outline two key models governing the generation of random fibre lasers: the average power balance model and the nonlinear Schrödinger equation based model. Recently invented random distributed feedback fibre lasers represent a new and exciting field of research that brings together such diverse areas of science as laser physics, the theory of disordered systems, fibre optics and nonlinear science. Stable random generation in optical fibre opens up new possibilities for research on wave transport and localization in disordered media. We hope that this review will provide

  13. Advertising media selection and planning

    NARCIS (Netherlands)

    Moorman, M.; Neijens, P.C.; Smit, E.G.; Belch, M.A.; Belch, G.E.

    2010-01-01

    Reach, frequency, and timing are key concepts in selecting TV, radio, newspapers, magazines, out-of-home, direct mail, Internet, and other media for advertising campaigns. We discuss these concepts and their role in media selection and media planning processes. We also describe media and audience

  14. Mixed-Media File Systems

    NARCIS (Netherlands)

    Bosch, H.G.P.

    1999-01-01

    This thesis addresses the problem of implementing mixed-media storage systems. In this work a mixed-media file system is defined to be a system that stores both conventional (best-effort) file data and real-time continuous-media data. Continuous-media data is usually bulky, and servers storing and

  15. Media preparation and bacteriological tools.

    Science.gov (United States)

    Elbing, Karen; Brent, Roger

    2002-08-01

    Recipes are provided in this unit for minimal liquid media, rich liquid media, solid media, top agar, and stab agar. Also included are descriptions and useful information about tools used with growth media such as inoculating loops, sterile toothpicks and spreaders.

  16. Acceptability of oral iodinated contrast media: a head-to-head comparison of four media

    Science.gov (United States)

    Ngan-Soo, E; McCoubrie, P

    2013-01-01

    Objective: To assess the palatability of iodinated oral contrast media commonly used in abdominopelvic CT and CT colonography (CTC). Methods: 80 volunteers assessed the palatability of a 20-ml sample of a standard 30 mg ml−1 dilution of Omnipaque® (iohexol; GE Healthcare, Cork, Ireland), Telebrix® (meglumine ioxithalamate; Guerbet, Aulnay-sous-Bois, France), Gastromiro® (iopamidol; Bracco, High Wycombe, UK) and Gastrografin® (sodium diatrizoate and meglumine diatrizoate; Bayer, Newbury, UK) in a computer-generated random order. Results: Gastrografin is rated significantly less palatable than the remaining media (pcontrast media than both Gastromiro and Gastrografin, which has potential implications in compliance with both abdominopelvic CT and CTC. PMID:23564884

  17. Children's media policy.

    Science.gov (United States)

    Jordan, Amy B

    2008-01-01

    Amy Jordan addresses the need to balance the media industry's potentially important contributions to the healthy development of America's children against the consequences of excessive and age-inappropriate media exposure. Much of the philosophical tension regarding how much say the government should have about media content and delivery stems from the U.S. Constitution's First Amendment protection against government interference in free speech, including commercial speech. Courts, Jordan says, have repeatedly had to weigh the rights of commercial entities to say what they please against the need to protect vulnerable citizens such as children. This balancing act is complicated even further, she says, because many government regulations apply only to broadcast television and not to non-broadcast media such as the Internet or cable television, though Congress has addressed the need to protect children's privacy online. The need to protect both free speech and children has given rise to a fluid media policy mix of federal mandates and industry self-regulation. Jordan describes the role of the three branches of the federal government in formulating and implementing media policy. She also notes the jockeying for influence in policymaking by industry lobbies, child advocacy groups, and academic researchers. The media industry itself, says Jordan, is spurred to self-regulation when public disapproval grows severe enough to raise the possibility of new government action. Jordan surveys a range of government and industry actions, from legislatively required parental monitoring tools, such as the V-Chip blocking device on television sets, to the voluntary industry ratings systems governing television, movies, and video games, to voluntary social website disclosures to outright government bans, such as indecency and child privacy information collection. She considers the success of these efforts in limiting children's exposure to damaging content and in improving parents

  18. DIGITALIZATION AND NEW MEDIA LANDSCAPE

    OpenAIRE

    Tadej Praprotnik

    2016-01-01

    The article presents the phenomena of new communication technologies. It exposes the role of social media (Web 2.0) and sketches some global trends within the field of new media. It further outlines basic characteristics of traditional mass communication and consumption of media products, and as a counter-part presents interactive nature of a new media and the phenomena of user-generated media contents. The main focus of the article is the process of digitalization and its influence on import...

  19. Haters Phenomena in Social Media

    OpenAIRE

    Pradipta, Angga; Lailiyah, S.Sos, M.I.Kom, Nuriyatul

    2016-01-01

    Social media is internet-basic media, functioned as interaction media room based on multimedia technology. And social media created some effects. One of the negative effects of social media is haters phenomena. Haters are a person who easily said dirty words, harass, and humiliate to others. This phenomena causes anxiety—especially in Indonesia, even the Government issued public policy and letter of regulation about this phenomena, through Paragraph 27 verse (3) IT Constitution, Paragraph 45 ...

  20. Analysis of Thomsen parameters for finely layered VTI media

    International Nuclear Information System (INIS)

    Berryman, J.G.; Berge, P.A.

    1997-01-01

    The range of Thomsen's anisotropy parameters ε and δ for vertical transversely isotropic (VTI) media when the anisotropy is due to fine layering of isotropic elas-tic materials is considered. We show that ε lies in the range -3/8 ≤ ε ≤ 1/2 v p 2 > p-2 >-1 for finely layered media having constant density; smaller positive and all negative values of ε occur for media with large fluctuations in the Lamacute e parameter λ We show that sign(δ) = sign ( p -2 > - s -2 > s 2 /v p 2 >) for constant density media, so δ can be either positive or negative. Among all theoretically possible random media, posi-tive and negative δ are equally likely in finely layered media limited to two types of constituent layers. Lay-ered media having large fluctuations in Lamacute e λ are the ones most likely to have positive δ. Since Gassmann's results for fluid-saturated porous media show that the effects of fluids influence only the λ Lamacute e constant, not the shear modulus μ, these results suggest that positive δ occurring together with positive but small ε may be indicative of changing fluid content in layered earth

  1. Screen Media Exposure and Obesity in Children and Adolescents.

    Science.gov (United States)

    Robinson, Thomas N; Banda, Jorge A; Hale, Lauren; Lu, Amy Shirong; Fleming-Milici, Frances; Calvert, Sandra L; Wartella, Ellen

    2017-11-01

    Obesity is one of the best-documented outcomes of screen media exposure. Many observational studies find relationships between screen media exposure and increased risks of obesity. Randomized controlled trials of reducing screen time in community settings have reduced weight gain in children, demonstrating a cause and effect relationship. Current evidence suggests that screen media exposure leads to obesity in children and adolescents through increased eating while viewing; exposure to high-calorie, low-nutrient food and beverage marketing that influences children's preferences, purchase requests, consumption habits; and reduced sleep duration. Some evidence also suggests promise for using interactive media to improve eating and physical activity behaviors to prevent or reduce obesity. Future interdisciplinary research is needed to examine the effects of newer mobile and other digital media exposures on obesity; to examine the effectiveness of additional interventions to mitigate the adverse effects of media exposures on obesity and possible moderators and mediators of intervention effects; to effectively use digital media interventions to prevent and reduce obesity; and to uncover the mechanisms underlying the causal relationships and interactions between obesity-related outcomes and media content, characteristics, and context. Copyright © 2017 by the American Academy of Pediatrics.

  2. A survey of contrast media used in coronary angiograph

    International Nuclear Information System (INIS)

    Weikl, A.; Hubmann, M.

    1982-01-01

    In recent years, various contrast media have been developed for use in coronary angiography. These contrast media may be divided into ionic contrast media of high osmolality, those of low osmolality, and nonionic contrast materials. We conducted our own clinical studies with 40 patients. In random succession a standard contrast medium (ionic, of high osmolality) and a new-generation contrast medium (either nonionic or ionic with low osmolality) were injected into the right and left coronary arteries. After each injection we measured the systolic and diastolic blood pressure using a liquid-filled coronary catheter. In addition, the change in the length of the cardiac cycle was registered in terms of the R-R interval (in ms) and at the same time, leads I, II, and III of the ECG were recorded. We studied the influence of the various contrast media on the activity of ATPase in in vitro experiments, using Lasser and Lang's. When ionic contrast media of low osmolality and nonionic contrast media were utilized the heart rate showed no change. Disturbances of rhythm such as ventricular tachycardia or fibrillation were not observed. All of the contrast media used produced the same ECG changes. These changes can be ascribed to the inhibition of ATPase. The arterial blood pressure was lowered significantly only by ionic contrast media of high osmolality only. (orig.)

  3. Screen Media Exposure and Obesity in Children and Adolescents

    Science.gov (United States)

    Robinson, Thomas N.; Banda, Jorge A.; Hale, Lauren; Lu, Amy Shirong; Fleming-Milici, Frances; Calvert, Sandra L.; Wartella, Ellen

    2018-01-01

    Obesity is one of the best-documented outcomes of screen media exposure. Many observational studies find relationships between screen media exposure and increased risks of obesity. Randomized controlled trials of reducing screen time in community settings have reduced weight gain in children, demonstrating a cause and effect relationship. Current evidence suggests that screen media exposure leads to obesity in children and adolescents through increased eating while viewing; exposure to high-calorie, low-nutrient food and beverage marketing that influences children’s preferences, purchase requests, consumption habits; and reduced sleep duration. Some evidence also suggests promise for using interactive media to improve eating and physical activity behaviors to prevent or reduce obesity. Future interdisciplinary research is needed to examine the effects of newer mobile and other digital media exposures on obesity; to examine the effectiveness of additional interventions to mitigate the adverse effects of media exposures on obesity and possible moderators and mediators of intervention effects; to effectively use digital media interventions to prevent and reduce obesity; and to uncover the mechanisms underlying the causal relationships and interactions between obesity-related outcomes and media content, characteristics, and context. PMID:29093041

  4. Random scalar fields and hyperuniformity

    Science.gov (United States)

    Ma, Zheng; Torquato, Salvatore

    2017-06-01

    Disordered many-particle hyperuniform systems are exotic amorphous states of matter that lie between crystals and liquids. Hyperuniform systems have attracted recent attention because they are endowed with novel transport and optical properties. Recently, the hyperuniformity concept has been generalized to characterize two-phase media, scalar fields, and random vector fields. In this paper, we devise methods to explicitly construct hyperuniform scalar fields. Specifically, we analyze spatial patterns generated from Gaussian random fields, which have been used to model the microwave background radiation and heterogeneous materials, the Cahn-Hilliard equation for spinodal decomposition, and Swift-Hohenberg equations that have been used to model emergent pattern formation, including Rayleigh-Bénard convection. We show that the Gaussian random scalar fields can be constructed to be hyperuniform. We also numerically study the time evolution of spinodal decomposition patterns and demonstrate that they are hyperuniform in the scaling regime. Moreover, we find that labyrinth-like patterns generated by the Swift-Hohenberg equation are effectively hyperuniform. We show that thresholding (level-cutting) a hyperuniform Gaussian random field to produce a two-phase random medium tends to destroy the hyperuniformity of the progenitor scalar field. We then propose guidelines to achieve effectively hyperuniform two-phase media derived from thresholded non-Gaussian fields. Our investigation paves the way for new research directions to characterize the large-structure spatial patterns that arise in physics, chemistry, biology, and ecology. Moreover, our theoretical results are expected to guide experimentalists to synthesize new classes of hyperuniform materials with novel physical properties via coarsening processes and using state-of-the-art techniques, such as stereolithography and 3D printing.

  5. Contemplative Media Studies

    Directory of Open Access Journals (Sweden)

    Kevin Healey

    2015-08-01

    Full Text Available The psychological and socio-economic implications of digital technologies call for scholarship that engages questions about the nature of human consciousness, the construction of the self and the ethics of technical development. In this article, I outline a framework for an approach called contemplative media studies. This approach incorporates several different scholarly threads, namely: via critical political-economic media scholarship, a focus on achieving social and economic justice through policy initiatives and structural reform; via media and religious scholarship, an interest in the religious dimensions of digital culture and the role of media in shaping religious identity; and via contemplative studies, an appreciation of the applicability of contemplative principles to research methods and theory. This framework allows us to examine the spiritual ideology that drives the construction of commercial digital platforms and to ask whether alternative platforms might better catalyze human development. Anchored in a critical commitment to socio-economic justice, contemplative media studies is aimed at articulating an ethically-responsive and economically-sustainable architecture of human flourishing.

  6. Light Condensation and Localization in Disordered Photonic Media: Theory and Large Scale ab initio Simulations

    KAUST Repository

    Toth, Laszlo Daniel

    2013-01-01

    Disordered photonics is the study of light in random media. In a disordered photonic medium, multiple scattering of light and coherence, together with the fundamental principle of reciprocity, produce a wide range of interesting phenomena

  7. Infinite range correlations of intensity in random media

    Indian Academy of Sciences (India)

    These correlations originate from scattering events which take place close to a ... tribution of the C0-term to the general four-point function, defined as .... product of two average intensities, which cancel the denominator in the definition of the.

  8. Effective permittivity of random composite media: A comparative study

    International Nuclear Information System (INIS)

    Prasad, Ashutosh; Prasad, K.

    2007-01-01

    In the present study, experimental data for effective permittivity of amorphous, polycrystalline thick films, and ceramic form of samples, taken from the literature, have been chosen for their comparison with those yielded by different mixture equations. In order to test the acceptability of dielectric mixture equations for high volume fractions of the inclusion material in the mixture, eleven such equations have been chosen. It is found that equations given by Cuming, Maxwell-Wagner, Webmann, Skipetrov and modified Cule-Torquato show their coherence and minimal deviation from the experimental results of permittivity for all the chosen test materials almost over the entire measurement range of volume fractions. It is further found that Maxwell-Wagner, Webmann, and Skipetrov equations yielded equivalent results and consequently they have been combined together and reckoned as a single equation named MWWS. The study revealed that the Cuming equation had the highest degree of acceptability (errors <±1-5%) in all the cases

  9. Multiple Scattering of Electromagnetic Waves in Discrete Random Media.

    Science.gov (United States)

    1984-12-31

    submitted to IEEE Trans. S Antennas and Propagation. 1. A. Killey and G . H . Meeten , Optical extinction and refraction of concentrated latex...simplifies to 91--9" X n n oTnn,, fix"’T Dn n ’ (X)[2kaj X(2Ka) h (2ka)-2Kaj (2Ka) h ,(2ka)] +f[ g (x)-l]ji(Kx) h ,(kx)x2 dx (16) V-v where D ,(X) is the...U) PENNSYLVANIA STATE UNIV UNIVERSITY PARK NAVE PROPAGATION LAB. UNLSIIDY AR TAL. 31 DEC 84 F/ G 29/14 N m~ h ~hEhhhE- h i F , 1. Ia 2- Ŗ-5~r g6 L3 2 I

  10. Multiple Scattering of Waves in Discrete Random Media.

    Science.gov (United States)

    1987-12-31

    15. A. KiUey and G . H . Meeten , "Optical extinction and refractioncan Mathematical Society, Providence, R.I., 1962), Vol. 13, pp. of concentrated latex...Eyring. H , J. Walter and G . Kimball [1944] Quantum Chemistry, Wiley, New York. It. Frbhlich. H . [1949] Theory of Dielectics. Dielectric Consint and...s and Ii) [ g (x)- li,;(Kx) h (kx)x2 dx. (10) + (-u C 2I Bvt15a 888 IFEFETRANSACTIONS ON ANTENNAS AND PROPAGATION. VOL A P-33. NO.8. A UGUST 1985 and

  11. Superfluid H3e in globally isotropic random media

    Science.gov (United States)

    Ikeda, Ryusuke; Aoyama, Kazushi

    2009-02-01

    Recent theoretical and experimental studies of superfluid H3e in aerogels with a global anisotropy created, e.g., by an external stress have definitely shown that the A -like phase with an equal-spin pairing in such aerogel samples is in the Anderson-Brinkman-Morel (ABM) (or axial) pairing state. In this paper, the A -like phase of superfluid H3e in globally isotropic aerogel is studied in detail by assuming a weakly disordered system in which singular topological defects are absent. Through calculation of the free energy, a disordered ABM state is found to be the best candidate of the pairing state of the globally isotropic A -like phase. Further, it is found through a one-loop renormalization-group calculation that the coreless continuous vortices (or vortex-Skyrmions) are irrelevant to the long-distance behavior of disorder-induced textures, and that the superfluidity is maintained in spite of lack of the conventional superfluid long-range order. Therefore, the globally isotropic A -like phase at weak disorder is, like in the case with a globally stretched anisotropy, a glass phase with the ABM pairing and shows superfluidity.

  12. Representative of the Media

    International Nuclear Information System (INIS)

    Domenech, F.

    2007-01-01

    Francesc Domenech recalled that the Vandellos-I accident created a very difficult situation for the nuclear industry. During the crisis the nuclear sector decided not to participate in any media activities. Finally, the industry realised that not being open only exacerbated the credibility crisis. The closure of the Vandellos -I power plant decreased the stress and offered an opportunity for the nuclear sector to change its attitude and public relations. In Mr. Domenech's view the Vandellos-I decommissioning project is a technical challenge undertaken by society. ENRESA made great efforts to rebuild mutual trust between the nuclear industry and the media. For the first time, journalists were provided with fluid data, some of them very complex, which the media had to render more understandable for the public. Finally, Mr. Domenech observed that nowadays it is the regulator which most needs to gain credibility. (author)

  13. Foams in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Marsden, S.S.

    1986-07-01

    In 1978 a literature search on selective blocking of fluid flow in porous media was done by Professor S.S. Marsden and two of his graduate students, Tom Elson and Kern Huppy. This was presented as SUPRI Report No. TR-3 entitled ''Literature Preview of the Selected Blockage of Fluids in Thermal Recovery Projects.'' Since then a lot of research on foam in porous media has been done on the SUPRI project and a great deal of new information has appeared in the literature. Therefore we believed that a new, up-to-date search should be done on foam alone, one which would be helpful to our students and perhaps of interest to others. This is a chronological survey showing the development of foam flow, blockage and use in porous media, starting with laboratory studies and eventually getting into field tests and demonstrations. It is arbitrarily divided into five-year time periods. 81 refs.

  14. Subsidizing Media Innovation

    DEFF Research Database (Denmark)

    Kammer, Aske; Hobel, Emil

    When the Danish Parliament revised the media-subsidy framework in 2013/2014, one of the new initiatives was the introduction of a pool of funding earmarked to establishing and developing new news media – the so-called “innovation fund”. So, as the news industry struggles to keep journalism a viable...... and economically sustainable activity, the institutionalization of financial support for media innovation constitute one way for policy makers to bring (parts of) the journalistic environment up-to-date with the digital age, thereby improving the conditions for an informed citizenry in the future (Kammer...... scrutinizes the practical administration of the innovation fund in the first two years of its existence, analyzing all applications for innovation subsidies in 2014 and 2015 as well as all acceptance and rejection letters. With this empirical material and a combination of quantitative and qualitative...

  15. Media and metamedia management

    CERN Document Server

    Araújo, Xosé; Fernández, Valentín; García, Xosé

    2017-01-01

    Media and Metamedia Management has contributions from seven prestigious experts, who offer their expertise and the view from their vantage point on communication, journalism, advertising, audiovisual, and corporate, political, and digital communication, paying special attention to the role of new technologies, the Internet and social networks, also from an ethics and legal dimension. A total of 118 authors belonging to 31 universities from Spain, Portugal, England and Ecuador have contributed to this book edited, coordinated and introduced by professors Francisco Campos-Freire and Xosé López-García, from the University of Santiago de Compostela, José Rúas-Araújo, from the University of Vigo, and Valentín A. Martínez-Fernández, from the University of A Coruña. Readers may also enjoy 66 articles, grouped into diverse chapters, on Journalism and cyberjournalism, audiovisual sector and media economy, corporate and institutional communication, and new media and metamedia.

  16. Media and Multiplicity

    DEFF Research Database (Denmark)

    Blaagaard, Bolette

    2010-01-01

    In the past few years continental Europe has experienced a resurgence of right-wing party politics, nationalism and xenophobia. In this nationalist revival the media and advanced communications technologies have played a significant role, as evidenced by the debates following cases...... such as the Danish cartoon controversy, and Dutch politician Geert Wilders’s film, Fitna. Simultaneously, however, the media is more diverse and rhizomatic than ever and offers potential for cosmopolitanism, transnational ethical relations as well as radical anti-racist and anti-fascist interventions. This article...... explores the tensions within the relation between journalistic practice and the construction of the idea of the nation and the multiplicity of media and cultures which inhabit the spheres of journalism and nation....

  17. Enterprise Social Media

    DEFF Research Database (Denmark)

    Khajeheian, Datis

    2018-01-01

    This article reports an ethnographic research on effect of enterprise social media on communication of members in entrepreneurial teams. The researcher acted as an entrepreneur and as a team member in two entrepreneurial projects to observe the communication of team members within the enterprise...... social media. In addition to observation, he conducted some interviews with team members to collect supplementary data. A theoretical framework developed from an array of three metaphors: leaky pipe, echo chamber and social lubricant, and four organizational learning processes: social capital, boundary...... work, attention allocation and social analytics. By the interpretation of the collected data, a new metaphor of “living room” was proposed. This metaphor suggests that enterprise social media provide a space for interaction of internal-external people similar to what home members and guests do...

  18. Media for Reflection

    DEFF Research Database (Denmark)

    Knudsen, Morten

    2016-01-01

    This article develops the concept media for reflection in the interest of conceptualizing the interpretative frames that enable and limit reflection in management and leadership education. The concept ‘media for reflection’ allows us to conceptualize the social and cultural mediation of reflection...... without reducing reflection to an effect of the social structures and cultural norms in which it is embedded. Based on the developed theoretical framework, this article analyses how a renaissance ‘mirror for princes’ and contemporary research-based management education mediate reflection. The content...... of the mediations is analysed as well as the societal and organizational background. Furthermore, the means by which the two media enable and limit reflection in different ways is compared. Finally, the article discusses possible implications of the analysis in terms of management and leadership education....

  19. Boiling in porous media

    International Nuclear Information System (INIS)

    1998-01-01

    This conference day of the French society of thermal engineers was devoted to the analysis of heat transfers and fluid flows during boiling phenomena in porous media. This book of proceedings comprises 8 communications entitled: 'boiling in porous medium: effect of natural convection in the liquid zone'; 'numerical modeling of boiling in porous media using a 'dual-fluid' approach: asymmetrical characteristic of the phenomenon'; 'boiling during fluid flow in an induction heated porous column'; 'cooling of corium fragment beds during a severe accident. State of the art and the SILFIDE experimental project'; 'state of knowledge about the cooling of a particulates bed during a reactor accident'; 'mass transfer analysis inside a concrete slab during fire resistance tests'; 'heat transfers and boiling in porous media. Experimental analysis and modeling'; 'concrete in accidental situation - influence of boundary conditions (thermal, hydric) - case studies'. (J.S.)

  20. Media and (Demythologization

    Directory of Open Access Journals (Sweden)

    Damir Kukić

    2017-05-01

    Full Text Available The media participate in the creation of new myths in modern society. Some of these myths have been created in the entertainment industry as well as in celebrity culture. The new media stars, regardless of the period of their popularity, function as part of the star strategy. However, as an element of the cultural matrix, the media also participate in the process of creating new political myths. In ethno-national and closed societies the myths function as a fundamental component for the unification of a nation and the definition of its identity. In such a context, their role is to create an image of the world, by shaping images from the past, in which people from other cultures and nations are presented as enemies.

  1. Media Challenging Status Quo

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    and Libya creating headlines like “the Facebook revolution”. On the other hand, several scholars argue that it is naive to believe that social media in themselves create change: they may at the best facilitate already existing social and political movements (Downing 2008, Christakis & Fowler 2010...... and communication research is currently engaging in a longer and deeper process of examining and assessing the cultural consequences of networked communication. One present challenge is to understand digital media and networked communication at the intersection of established and countercultural, utopian......Digital media and especially so-called ‘social media’ have on the one hand been ascribed the power to change societies and empower democratic movements following the thoughts of e.g. Rheingold (2004), recently fueled by the democratic uprising in Arabic countries such as Egypt, Tunisia, Iran...

  2. Open Media Training Session

    CERN Multimedia

    CERN. Geneva; Marchant, Nadia

    2010-01-01

    Have you ever wondered how the media work and why some topics make it into the news and other don't? Would you like to know how to (and how not to) give an interview to a journalist? With the LHC preparing for first collisions at high energies, the world's media are again turning their attention to CERN. We're all likely to be called upon to explain what is happening at CERN to media, friends and neighbours. The seminar will be given by BBC television news journalists Liz Pike and Nadia Marchant, and will deal with the kind of questions we're likely to be confronted with through the restart period. Follow the webcast: http://webcast.cern.ch/

  3. 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....

  4. Internet and Cross Media Productions

    DEFF Research Database (Denmark)

    Petersen, Anja Bechmann

    2006-01-01

    , the Internet continues to play a minor role when compared to older media. The content of the cross media concepts and organizations' history are crucial elements in deciding the priority and use of platforms. Methodologically, the article approaches cross media and the roles of the Internet on a micro......Convergence is one of the hot topics in Internet studies. Recently, however, media organizations have turned their focus to cross media communication. Media organizations are interested in optimizing communication across platforms such as TV, radio, websites, mobile telephones and newspapers....... The aim of this article is to examine the roles of the Internet when emphasis is put on cross media rather than convergence. This article proposes not one unidirectional convergent tendency but manifold roles of the Internet in cross media communication. Inside the media organizations, however...

  5. Children, Adolescents, and the Media.

    Science.gov (United States)

    2013-11-01

    Media, from television to the "new media" (including cell phones, iPads, and social media), are a dominant force in children's lives. Although television is still the predominant medium for children and adolescents, new technologies are increasingly popular. The American Academy of Pediatrics continues to be concerned by evidence about the potential harmful effects of media messages and images; however, important positive and prosocial effects of media use should also be recognized. Pediatricians are encouraged to take a media history and ask 2 media questions at every well-child visit: How much recreational screen time does your child or teenager consume daily? Is there a television set or Internet-connected device in the child's bedroom? Parents are encouraged to establish a family home use plan for all media. Media influences on children and teenagers should be recognized by schools, policymakers, product advertisers, and entertainment producers. Copyright © 2013 by the American Academy of Pediatrics.

  6. Using the media.

    Science.gov (United States)

    1994-01-01

    To use the mass media (newspaper, radio, and TV) to reach a large audience with information about AIDS, it is important to choose the media outlets carefully, since they use information that satisfies their audience in content and style. For example, radio, TV, or videos are best to reach illiterate groups. Ways to approach each sector of the written and electronic media include press releases, news conferences, information kits, and personal contacts. Letters to the editor and offers of submitting articles for publication are additional ways to approach newspapers. Audio- or videocassettes with interviews or images conveying HIV/AIDS prevention messages can be submitted to TV and radio stations. It is important to present the information attractively to gain the journalists' attention. News releases should include sources of information and a contact name. It is important to inform the mass media of successes revolving around AIDS prevention, emphasizing local successes. One should identify what media slots have the most influence. For example, a medical officer in Chiang Mai, Thailand, notes that popular disc jockeys have more influence than do government information broadcasts. It is best to promote facts that probably will increase support for AIDS prevention campaigns. If possible, groups should seek free space or air time for AIDS prevention messages. AIDS prevention messages should not use fear because it does not promote safer sexual behavior. Instead, they should link condom use with a sense of independence, responsibility, and being fashionable. Leaflets, posters, videotapes, slides, displays, slogans, audiocassettes, T-shirts, stickers, and other activities or products reinforce the effectiveness of media campaigns. Interviews with or feature articles and programs about people infected or affected by HIV/AIDS chip away at the belief that "AIDS could never happen to me."

  7. Undergraduates and Their Use of Social Media: Assessing Influence on Research Skills

    Science.gov (United States)

    Nwangwa, Kanelechi C. K.; Yonlonfoun, Ebun; Omotere, Tope

    2014-01-01

    This research investigates the influence of social media usage on research skills of undergraduates offering Educational Management at six different universities randomly selected from the six geo-political zones in Nigeria. Various studies on the effects of social media on students have concentrated mainly on academic performance (Kirschner &…

  8. Automation and Its Funding in the Library Media Centers in Secondary Schools in Georgia: A Survey.

    Science.gov (United States)

    Baggett, Ann Utsey

    This report presents the results of a study whose purpose was to determine what automation is present in the library media centers in Georgia secondary schools and how it has been funded. A three-part questionnaire was sent to the media specialists in 50% of the secondary schools in Georgia, which were randomly selected. The analysis of the…

  9. Using Natural Experiments to Study the Impact of Media on the Family

    Science.gov (United States)

    Price, Joseph; Dahl, Gordon B.

    2012-01-01

    The randomized trial is the gold standard in scientific research and is used by several fields to study the effects of media. Although useful for studying the immediate response to media exposure, the experimental approach is not well suited to studying long-term effects or behavior outside the laboratory. The "natural experiment" approach, a…

  10. The Effect of Social Media Usage on Course Achievement and Behavior

    Science.gov (United States)

    Alghazo, Yazan M.; Nash, Julie A.

    2017-01-01

    This study investigated the effects of social media usage as a classroom management tool on students' achievement and their behavior in class. Groups were determined by choosing random samples of different classes. The treatment group included the social media application "whatsapp" which all students and the instructor were asked to…

  11. Mobile Media Photography

    DEFF Research Database (Denmark)

    Svabo, Connie; Shanks, Michael

    2013-01-01

    Mobile media photography marks a shift in orientation from the image towards photography as a mode of engagement. This leads is to explore the processes of experience and documentation that mobile media help to constitute. We unfold two aspects of the process of photography: photography as temporal......, archaeological engagement, and photography as spatial, geographical engagement. Finally, as a closing perspective we point out that vernacular photography may be read as an intersection between a personal means of expression and corporate financial interest....

  12. Acute otitis media.

    Science.gov (United States)

    Dickson, Gretchen

    2014-03-01

    One in 4 children will have at least 1 episode of acute otitis media (AOM) by age 10 years. AOM results from infection of fluid that has become trapped in the middle ear. The bacteria that most often cause AOM are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. Differentiating AOM from otitis media with effusion (OME) is a critical skill for physicians, as accurate diagnosis will guide appropriate treatment of these conditions. Although fluid is present in the middle ear in both conditions, the fluid is not infected in OME as is seen in AOM patients. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Strategy and New Media

    DEFF Research Database (Denmark)

    Plesner, Ursula; Gulbrandsen, Ib Tunby

    2015-01-01

    Despite current attention to the materiality of organizations and the performative role of tools, devices, artefacts and objects in processes of strategy-making, the impact of new media has not been thoroughly conceptualized in the strategy literature. We argue that new media challenge core...... assumptions in strategy about control, boundaries and choice. To understand their constitutive effects and the implications for strategy-making, it is necessary to develop a research agenda oriented towards understanding technological affordances – but not only in local practices. Due to vital characteristics...

  14. Media and Influence

    Science.gov (United States)

    Bennett, William H.

    The public information media provides information on current events (news), entertainment (programming), and opinions offered by trusted public sources (e.g., business, academic or religious spokespersons, journalists, and government officials). Consequently, it is a major force in shaping a populace's attitudes toward significant social issues and of great interest to intervention planners. The chapter attempts to provide modelers and intervention analysts alike with sufficient understanding of media mechanisms and current research that they can begin contributing to, and benefiting from this important area of study.

  15. Multisided Media Markets

    DEFF Research Database (Denmark)

    Lindstädt, Nadine

    Media markets recently have been identified as multisided markets. The application of the theory of multisided markets provides a better understanding of such markets. It enriched the hitherto economic approach and led to new insights and perspectives especially for the antitrust authorities when...... evaluating competition constraints and mergers. This paper reviews the theory of multisided markets and subsequently applies it to media markets. Finally the paper draws attention to the new perspectives and insights the theory provides but also brings open research questions to light....

  16. Smartphones as locative media

    CERN Document Server

    Frith, Jordan

    2015-01-01

    Smartphone adoption has surpassed 50% of the population in more than 15 countries, and there are now more than one million mobile applications people can download to their phones. Many of these applications take advantage of smartphones as locative media, which is what allows smartphones to be located in physical space. Applications that take advantage of people's location are called location-based services, and they are the focus of this book. Smartphones as locative media raise important questions about how we understand the complicated relationship between the Internet and physical space

  17. Hypertextuality and Social Media

    DEFF Research Database (Denmark)

    Albu, Oana Brindusa; Etter, Michael

    2016-01-01

    Texts and conversations are central to the constitution of organizations. Through the use of social media technologies, organizational members and nonorganizational members alike have the capacity to author organizational texts that co-constitute an organization as an entity with a specific...... identity in a situational space and time. The implications of this ability are underexplored. This study focused on how two organizations used the social media technology Twitter to interact with their constituents. The article adopts communication-centered and sociomateriality perspectives to illustrate...

  18. HTML5 Media

    CERN Document Server

    Powers, Shelley

    2011-01-01

    If you're a web developer or designer familiar with CSS and JavaScript, this tightly focused introduction shows you how to add HTML5 media elements to your web pages, and how to provide custom controls for letting web visitors interact with the content. You'll also learn how to provide subtitles and captions, using file formats that work in browsers now. This book includes code samples and downloadable examples to help you take full advantage of audio and video in your web pages. Ensure your audio or video works in all browsers that support HTML5 media elementsLearn about widely supported me

  19. Random nanolasing in the Anderson localized regime

    DEFF Research Database (Denmark)

    Liu, Jin; Garcia, P. D.; Ek, Sara

    2014-01-01

    The development of nanoscale optical devices for classical and quantum photonics is affected by unavoidable fabrication imperfections that often impose performance limitations. However, disorder may also enable new functionalities, for example in random lasers, where lasing relies on random...... multiple scattering. The applicability of random lasers has been limited due to multidirectional emission, lack of tunability, and strong mode competition with chaotic fluctuations due to a weak mode confinement. The regime of Anderson localization of light has been proposed for obtaining stable multimode...... random lasing, and initial work concerned macroscopic one-dimensional layered media. Here, we demonstrate on-chip random nanolasers where the cavity feedback is provided by the intrinsic disorder. The strong confinement achieved by Anderson localization reduces the spatial overlap between lasing modes...

  20. Read/write properties of oriented longitudinal recording media

    International Nuclear Information System (INIS)

    Uesaka, Y.; Nakatani, Y.; Hayashi, N.; Fukushima, H.

    2001-01-01

    The effect of orientation on the maximum recording density including the thermal stability effect was investigated using computer simulation. The necessary head current for a highly oriented medium is at most 10% larger than that for a 2D random medium. A recording density larger than 300 Gb/in 2 can be achieved with highly oriented media with 30 nm flying height

  1. Should nonionic radiographic contrast media be given to all patients?

    International Nuclear Information System (INIS)

    Parfrey, P.S.; Cramer, B.C.; McManamon, P.J.

    1988-01-01

    In the 1970s about one patient of every 40,000 who underwent intravenous urography died. It has been suggested that lives can be saved by using only nonionic or low-osmolarity contrast agents. The authors suggest a multicentre double-blind randomized controlled trial of nonionic versus ionic contrast media

  2. Mediatization Theory and Digital Media

    DEFF Research Database (Denmark)

    Finnemann, Niels Ole

    2011-01-01

    In the 20th century, the term "media logic" was introduced to denote the influence of independent mass media on political systems and other institutions. In recent years the idea has been reworked and labelled "mediatization" to widen the framework by including new media and new areas of applicat......In the 20th century, the term "media logic" was introduced to denote the influence of independent mass media on political systems and other institutions. In recent years the idea has been reworked and labelled "mediatization" to widen the framework by including new media and new areas...

  3. More Media, More People—On Social & Multimodal Media Intelligence

    OpenAIRE

    Degerstedt, Lars; Pelle, Snickars

    2017-01-01

    The purpose of this article is to address some challenges facing media intelligence in general, and competitive intelligence in particular within an altered information landscape. To understand this new situation, the notion of social and multimodal media intelligence are introduced. With cases taken primarily from the Swedish media intelligence sector, we argue that data driven media intelligence today needs to pay increasing attention to new forms of (A.) crowd-oriented and (B.) multimedia-...

  4. Homogenization of discrete media

    Energy Technology Data Exchange (ETDEWEB)

    Pradel, F.; Sab, K. [CERAM-ENPC, Marne-la-Vallee (France)

    1998-11-01

    Material such as granular media, beam assembly are easily seen as discrete media. They look like geometrical points linked together thanks to energetic expressions. Our purpose is to extend discrete kinematics to the one of an equivalent continuous material. First we explain how we build the localisation tool for periodic materials according to estimated continuum medium type (classical Cauchy, and Cosserat media). Once the bridge built between discrete and continuum media, we exhibit its application over two bidimensional beam assembly structures : the honey comb and a structural reinforced variation. The new behavior is then applied for the simple plan shear problem in a Cosserat continuum and compared with the real discrete solution. By the mean of this example, we establish the agreement of our new model with real structures. The exposed method has a longer range than mechanics and can be applied to every discrete problems like electromagnetism in which relationship between geometrical points can be summed up by an energetic function. (orig.) 7 refs.

  5. Dynamics of Media Attention

    NARCIS (Netherlands)

    Traag, V.A.; Reinanda, R.; Hicks, J.; van Klinken, G.; Aziz-Alaoui, M.A.; Bertelle, C.; Liu, X.; Olivier, D.

    2014-01-01

    Studies of human attention dynamics analyses how attention is focused on specific topics, issues or people. In online social media, there are clear signs of exogenous shocks, bursty dynamics, and an exponential or powerlaw lifetime distribution. We here analyse the attention dynamics of traditional

  6. Handboek Nieuwe Media

    NARCIS (Netherlands)

    Tom Bakker; Dr. Piet Bakker

    2011-01-01

    Voor mensen die beroepshalve met communicatie en informatie te maken hebben, is het belangrijk om op de hoogte te zijn van de meest actuele en relevante ontwikkelingen op dat terrein. Het gaat hierbij niet alleen over social media of web 2.0 - ook het zoeken, beheren en publiceren van informatie is

  7. Cyberbullying via Social Media

    Science.gov (United States)

    Whittaker, Elizabeth; Kowalski, Robin M.

    2015-01-01

    Recent years have witnessed a surge of research on cyberbullying. In this article, three studies examined prevalence rates of cyberbullying among college-age students, venues through which cyberbullying occurs, with a particular focus on social media, and perceptions of cyberbullying as a function of features of the target (e.g., peer, celebrity,…

  8. Islam and Media Representations

    Directory of Open Access Journals (Sweden)

    Mohamed Bensalah

    2006-04-01

    Full Text Available For the author of this article, the media’s treatment of Islam has raised numerous polymorphous questions and debates. Reactivated by the great scares of current events, the issue, though an ancient one, calls many things into question. By way of introduction, the author tries to analyse the complex processes of elaboration and perception of the representations that have prevailed during the past century. In referring to the semantic decoding of the abundant colonial literature and iconography, the author strives to translate the extreme xenophobic tensions and the identity crystallisations associated with the current media orchestration of Islam, both in theWest and the East. He then evokes the excesses of the media that are found at the origin of many amalgams wisely maintained between Islam, Islamism and Islamic terrorism, underscoring their duplicity and their willingness to put themselves, consciously, in service to deceivers and directors of awareness, who are very active at the heart of the politico-media sphere. After levelling a severe accusation against the harmful drifts of the media, especially in times of crisis and war, the author concludes by asserting that these tools of communication, once they are freed of their masks and invective apparatuses, can be re-appropriated by new words and bya true communication between peoples and cultures.

  9. Media challenging capitalism

    DEFF Research Database (Denmark)

    Sandvik, Kjetil

    Digital media and especially so-called ‘social media’ have on the one hand been ascribed the power to change societies and empower democratic movements following the thoughts of e.g. Rheingold (2004), recently fueled by the democratic uprising in Arabic countries such as Egypt, Tunisia, Iran and ...

  10. Femicide in media

    Directory of Open Access Journals (Sweden)

    Mršević Zorica

    2014-01-01

    Full Text Available Media in Serbia explain femicide usually as caused by poverty and alcoholism. This style is gender blind and socially stereotyped because of neglected gender aspects of male violence against women. Particular problem is lack of problematizing obvious social “permission” of male violence. Femicide is regularly presented as an incident, allegedly impossible for anticipation rather than tragic epilogue of long lasting male violence against women which as such exists as a part of traditional gender social relations and roles. Media overlook that alcohol and poverty may only contribute to intensification of already existing, widely accepted domination of men and subordination of women. Media reports as a rule didn’t enter deeper into problems of institutional and social context in which is perpetrated long lasting violence as prefacing femicide. Media also never criticize the social behavior of neighbors, relatives and all others informed on the domestic violence, but rather avoid „mixing“into privacy matters. Thus violence escalates without barriers, eventually developed in femicide, murder a woman, victim of this, decades long lasting violence.

  11. European media law

    NARCIS (Netherlands)

    Castendyk, O.; Dommering, E.; Scheuer, A.

    2008-01-01

    European Union legislation concerning electronic communications media is firmly established as an essential part of the law in the field in Europe. From relevant provisions of the European Convention of Human Rights and the EC Treaty to numerous directives, the most recent being the Audiovisual

  12. Media for Enterobacteriaceae

    NARCIS (Netherlands)

    Mossel, D.A.A.

    1985-01-01

    The ‘rag-bag character of ‘coli-aerogenes’ bacteria used originally as markers for process failure has prompted their substitution by the taxonomically accurately delineated group of Enterobacteriaceae. Media previously used for the detection or enumeration of the coli-aerogenes group can be adapted

  13. Media: A Pocket Guide.

    Science.gov (United States)

    Arrasjid, Harun; Arrasjid, Dorine Audrey

    An attempt has been made to provide a concise but comprehensive guide to instructional media for instructors, students, and teachers. Topics covered include audio learning systems, overhead projection, opaque projection, slide and filmstrip projection, projection surfaces, chalkboards and markboards, graphics, models, duplicating, motion pictures,…

  14. Contrast media: future aspects

    International Nuclear Information System (INIS)

    Weinmann, H.J.; Platzek, J.; Schirmer, H.; Pietsch, H.; Carretero, J.; Harto, J.; Medina, J.; Riefke, B.; Martin, J.

    2005-01-01

    In spite of the dramatic development in CT, there was no major breakthrough in the iodinated contrast media development. New agents based on hybrid between MRI and CT compounds may be a new innovative alternative. This new approach may also open new indications such as radiotherapy. (orig.)

  15. Corruption in the Media.

    NARCIS (Netherlands)

    Spence, E.H.

    2009-01-01

    Using a general model of corruption that explains and accounts for corruption across different corporate and professional activities, the paper will examine how certain practices in the media, especially in areas where journalism, advertising and public relations regularly intersect and converge,

  16. Social Media Empowerment (III)

    NARCIS (Netherlands)

    A. Cox

    2011-01-01

    full text via link. Synovate heeft de afgelopen twee jaar onderzoek verricht op dit terrein. Anita Cox, Emile Rikken en Stephan van Velthoven zetten op basis daarvan zaken op een rij in een serie van 5 artikelen, hier op Molblog te lezen. In dit artikel staat brand-building via social media

  17. Big Data, Small Media

    Directory of Open Access Journals (Sweden)

    Grant Bollmer

    2014-08-01

    Andrew Dubber Radio in the Digital Age Polity, Cambridge, 2013   Charles Ess Digital Media Ethics, Second Edition Polity, Cambridge, 2014   Graeme Kirkpatrick Computer Games and the Social Imaginary Polity, Cambridge, 2013   Dhiraj Murthy Twitter: Social Communication in the Twitter Age Polity, Cambrige, 2013   Jill Walker Rettberg Blogging, Second Edition Polity, Cambridge, 2014

  18. Digital media ethics

    DEFF Research Database (Denmark)

    Ess, Charles

    Designed as both a teaching text and reader for students and faculty across diverse disciplines, the book provides an "ethical toolkit" - an introduction to prevailing ethical frameworks - and shows their application to both general issues and specific case-studies in digital media (privacy...

  19. Expanding Media Reach

    Centers for Disease Control (CDC) Podcasts

    2007-11-01

    In this podcast, two nurses serving a Chinese American community show how they have used local ethnic media to communicate health messages.  Created: 11/1/2007 by National Diabetes Education Program (NDEP), a joint program of the Centers for Disease Control and Prevention and the National Institutes of Health.   Date Released: 11/11/2007.

  20. Using Media Effectively.

    Science.gov (United States)

    Danzer, Gerald A.; Newman, Mark

    1992-01-01

    Recommends that media presentations can be used effectively in the history classroom as images of reality. Suggests films and television programs and documentaries that can be utilized to show how movies play a role in shaping opinion and changing perceptions. (DK)

  1. The Indian Media Scenario.

    Science.gov (United States)

    Eapen, K. E.

    As background information for a discussion of India's communication system and its potential for social change, this paper briefly describes the country's physical characteristics, some of its cultural heritage and demographics, and the development of its education and railways. After a discussion of the folk media (traditional changes) of…

  2. Electrokinetics in porous media

    NARCIS (Netherlands)

    Luong, D.T.

    2014-01-01

    This thesis presents the PhD research on electrokinetics in porous media. Electrokinetic phenomena are induced by the relative motion between a fluid and a solid surface and are directly related to the existence of an electric double layer between the fluid and the solid grain surface.

  3. Eustachian tube three-dimensional reconstruction of secretory otitis media

    International Nuclear Information System (INIS)

    Yu Yafeng; Zhou Weirong; Bao Xueping; Li Min; Hu Zhenmin

    2006-01-01

    Objective: To study relationship between Eustachian tube and secretory otitis media and to explore the pathogeny of secretory otitis by three-dimensional reconstruction of Eustachian tube. Methods: Thirty cases of secretory otitis media (male 19, female 11) were selected randomly. Everyone was checked by otoscope and audiometry. Their bilateral Eustachian tubes were scanning by helix CT while making Valsalva's action. All images were passed on to work station to make three-dimensional reconstruction. Results: Four patients were found have Eustachian tube diseases, while most of patients' Eustachian tubes ventilated normally. Conclusions: Three-dimensional reconstruction of Eustachian tube can open out some pathogens of some secretory otitis medias. It will be helpful to diagnosis and therapy of secretory otitis media. (authors)

  4. Effective Social Media Engagement for Nonprofits: What Matters?

    Directory of Open Access Journals (Sweden)

    Julia L Carboni

    2015-03-01

    Full Text Available We employ public management relationship theory to examine how nonprofits can effectively engage social media stakeholders in two-way communication. Though many nonprofit organizations have a social media presence, there is variance in how well organizations use social media to engage stakeholders. Simply having a social media presence is not enough to engage stakeholders.  We examine Facebook posts of a stratified random sample of youth development organizations to determine what predicts stakeholder engagement. We find the type of Facebook post is a significant predictor of stakeholder engagement.  Longer posts also significantly predict increased stakeholder engagement.  At the organizational level, having many posts is a significant negative predictor of stakeholder engagement, indicating that users may feel bombarded and are less likely to engage.  Increased organizational spending on advertising as a proportion of total budget is positively associated with stakeholder engagement. 

  5. Need for Orientation, Media Uses and Gratifications, and Media Effects.

    Science.gov (United States)

    Weaver, David

    In order to study the influence of need for orientation and media gratifications on media use and media effects in political communication, two previous surveys were studied to compare the causal modeling approach and the contingent conditions approach. In the first study, 339 personal interviews were conducted with registered voters during a…

  6. Applying East Asian Media Diplomacy Models to African Media: A ...

    African Journals Online (AJOL)

    The last two decades have seen the extensive expansion of South African and Nigerian media on the African continent. However, while the link between media and diplomacy, and the role of media in visualising the state for foreign audiences have received a lot of scholarly attention internationally, relatively little work has ...

  7. Media Culture and Media Education in Modern School

    Science.gov (United States)

    Tolic, Mirela

    2011-01-01

    Culture is no longer conceivable without the media and/or new phenomena called. "Cyber" culture. The article discusses issues in what respect the different media, like TV, film and Internet are with different cultures, how it changes everyday life under influence of various forms of sophisticated communications media and what…

  8. Modeling of the write and read back performances of hexagonal Ba-ferrite particulate media for high density tape recording

    International Nuclear Information System (INIS)

    Lee, Jehyun; Fuger, Markus; Fidler, Josef; Suess, Dieter; Schrefl, Thomas; Shimizu, Osamu

    2010-01-01

    In this study, the signal-to-noise ratio (SNR) performances of longitudinally, randomly, and perpendicularly oriented particles, based on hexagonal barium ferrite (h-BaFe) platelets with an average volume of 2400 nm 3 have been studied as a function of the recording head to media distance by numerical micromagnetic simulations. The distances from the write head to media and from the read head to media were varied independently. For a fixed read distance and varied writing distances, the SNR was decreasing in larger write distance. An optimum write distance of 40 and 50 nm was found for the longitudinally oriented media and the perpendicularly oriented media, respectively. The optimum write distance for longitudinally oriented media, 40 nm, resulted in the local minimum SNR for the perpendicularly oriented media. In most write distances the perpendicularly oriented media show the outstanding best performance, but near the write distance of 40 nm the longitudinally oriented media work as good as the perpendicularly oriented media. In a fixed write distance with various read distances, the SNR was almost constant in each media whereas the average signal amplitude was exponentially decayed in larger read head to media distance. The best SNR was found in the perpendicularly oriented media at write head to media distance d write =20 nm and read head to media distance d read =40 nm. The best SNR value is 11.9 and 24.4 dB in time domain and frequency domain, respectively.

  9. Nonlinear lattice waves in heterogeneous media

    International Nuclear Information System (INIS)

    Laptyeva, T V; Ivanchenko, M V; Flach, S

    2014-01-01

    We discuss recent advances in the understanding of the dynamics of nonlinear lattice waves in heterogeneous media, which enforce complete wave localization in the linear wave equation limit, especially Anderson localization for random potentials, and Aubry–André localization for quasiperiodic potentials. Additional nonlinear terms in the wave equations can either preserve the phase-coherent localization of waves, or destroy it through nonintegrability and deterministic chaos. Spreading wave packets are observed to show universal features in their dynamics which are related to properties of nonlinear diffusion equations. (topical review)

  10. Orthodontic marketing through social media networks: the patient and practitioner's perspective.

    Science.gov (United States)

    Nelson, Kristin L; Shroff, Bhavna; Best, Al M; Lindauer, Steven J

    2015-11-01

    To (1) assess orthodontic patient and practitioner use of and preferences for social media and (2) investigate the potential benefit of social media in marketing and communication strategies in orthodontic practices. A survey was developed and randomly distributed to orthodontists via the American Association of Orthodontists and to patients/parents via private practices throughout the United States. Participants were asked to answer questions related to their use of social media and their perceptions of the use of social media in the orthodontic practice. Of the participants, 76% of orthodontists and 89% of patients/parents use social media. Furthermore, Facebook was the social media platform that was most preferred. Social media use was more common in female and younger adult participants. Orthodontists posted information more often in the morning (40%) and afternoon (56%), and patients/parents used social media mainly in the evening (76%). The most commonly used marketing strategies in the orthodontic practices were social media (76%) and a practice website (59%). Social media and practice websites were positively related with new patient starts (P  =  .0376, P  =  .0035, respectively). Most orthodontists and patients/parents used social media. Social media may be an effective marketing and communication tool in an orthodontic practice.

  11. Editorial: Pedagogical Media Ecologies

    Directory of Open Access Journals (Sweden)

    Dorothee M. Meister

    2014-07-01

    Full Text Available From educational gaming through portable e-readers to cell phones, media are interpenetrating educational spaces and activities. Accordingly, understanding media in environmental or ecological terms has become increasingly important for education internationally. In North America, for example, the centenary of McLuhan’s birth has focused attention on approaches to media – whether oral, textual, electronic or digital– as a kind of environment in which education takes place. In parts of Europe, the so-called mediatic turn – following on the linguistic and iconic turns – has similarly emphasized the role of media as a condition for the possibility of educational activities and programs. With a few exceptions1 the papers in this special issue were first presented at the conference «Educational Media Ecologies: International Perspectives» which took place at the University of Paderborn, Germany, on March 27–28, 2012.2 The event was an interdisciplinary and transatlantic endeavor to bring together a wide range of perspectives on various issues relevant to educational media ecologies,3 and on related debates on mediation, medialization, mediatization, and mediality.4 The purpose of this volume, like the conference, is to foster and deepen international dialogue in the area of educational media. Areas of research and scholarship relevant to this dialogue include educational media, media literacy, educational philosophy, and media and cultural studies. The contributions, described below, put conceptual issues as well as social practices and applications at the center of the debate. Klaus Rummler opens the issue by clarifying the concept of ecology itself. Referencing a range of work over the past 50 years, Rummler describes how ecological models have been cast in sociological, semiotic, cultural, mediatic and other terms, and he explains the implications of these various perspectives for the study of educational contexts. Rummler also

  12. Disordered resonant media: Self-induced transparency versus light localization

    Science.gov (United States)

    Novitsky, Denis V.

    2018-01-01

    We propose a concept of disordered resonant media, which are characterized by random variations of their parameters along the light propagation direction. In particular, a simple model of disorder considered in the paper implies random change of the density of active particles (two-level atoms). Within this model, the effect of disorder on self-induced transparency (SIT) is analyzed using numerical simulations of light pulse propagation through the medium. The transition from the SIT to localization regime is revealed as well as its dependence on the disorder level, atom density, medium thickness, and period of random variations.

  13. DISKURSUS ISLAM DALAM KONSTRUKSI MEDIA

    Directory of Open Access Journals (Sweden)

    Muhammad Fahmi

    2015-12-01

    Full Text Available This paper aims to examine how the secular media in Surakarta represent Islam in the case of Charlie Hebdo. Therefore, this study used discourse analysis of Theo van Leeuwen focusing on how the subject or actor of the show in the media. This study concluded that the media represent Islam not only with “Western ideology” through idioms such as radical Islamist militants and terrorists, but also with "Islamic ideology". It is done through the construction of Islam as a religion of moderation and delegitimize Charlie Hebdo as magazine satyr abusing freedom. Various strategies are used ranging from strategy passivation to interdetermination. In this case, there are two poles of attraction in both media, namely the Western and Islamic ideology. If both media are quoting from Western sources, the Western ideology dominates the media narrative. Conversely, when both media used Islamic sources, the influence of Islamic ideology dominates the narrative of both media.

  14. Media independence and dividend policy

    DEFF Research Database (Denmark)

    Farooq, Omar; Dandoune, Salma

    2012-01-01

    independence and dividend policies in emerging markets. Using a dataset from twenty three emerging markets, we show a significantly negative relationship between dividend policies (payout ratio and decision to pay dividend) and media independence. We argue that independent media reduces information asymmetries...... for stock market participants. Consequently, stock market participants in emerging markets with more independent media do not demand as high and as much dividends as their counterparts in emerging markets with less independent media. We also show that press independence is more important in defining......Can media pressurize managers to disgorge excess cash to shareholders? Do firms in countries with more independent media follow different dividend policies than firms with less independent media? This paper seeks to answer these questions and aims to document the relationship between media...

  15. Media life of the young

    DEFF Research Database (Denmark)

    Westlund, Oscar; Bjur, Jakob

    2014-01-01

    This is a thorough investigation into contemporary young people and their media life. The article conceptualizes a typology of media life, drawing on a theoretical body involving the sociology of generations, life course research, media life and individualization. This empirically derived typology...... makes a strong instrument for an understanding of the media life of the young, furnishing insights into how they have constructed their use of media. The investigation is based on a robust national survey with Swedes born 1994–2001, conducted in 2010, and focusing on four media: television, gaming......, the Internet and mobile devices. Two of the findings are particularly surprising. Firstly, the results reveal that the young generally lead heterogeneous media lives, varying with age and sex. Secondly, although some young people literarily live their life in media, there are also de facto young who live...

  16. Social media in adolescent health literacy education: a pilot study.

    Science.gov (United States)

    Tse, Carrie Kw; Bridges, Susan M; Srinivasan, Divya Parthasarathy; Cheng, Brenda Ss

    2015-03-09

    While health literacy has gained notice on a global stage, the initial focus on seeking associations with medical conditions may have overlooked its impact across generations. Adolescent health literacy, specifically in dentistry, is an underexplored area despite the significance of this formative stage on an individual's approach to healthy lifestyles and behaviors. The aim is to conduct a pilot study to evaluate the efficacy of three major social media outlets - Twitter, Facebook, and YouTube - in supporting adolescents' oral health literacy (OHL) education. A random sample of 22 adolescents (aged 14-16 years) from an English-medium international school in Hong Kong provided informed consent. Sociodemographic information, including English language background, social media usage, and dental experience were collected via a questionnaire. A pre- and post-test of OHL (REALD-30) was administered by two trained, calibrated examiners. Following pre-test, participants were randomly assigned to one of three social media outlets: Twitter, Facebook, or YouTube. Participants received alerts posted daily for 5 consecutive days requiring online accessing of modified and original OHL education materials. One-way ANOVA ( analysis of variance) was used to compare the mean difference between the pre- and the post-test results among the three social media. No associations were found between the social media allocated and participants' sociodemographics, including English language background, social media usage, and dental experience. Of the three social media, significant differences in literacy assessment scores were evident for participants who received oral health education messages via Facebook (P=.02) and YouTube (P=.005). Based on the results of the pilot study, Facebook and YouTube may be more efficient media outlets for OHL promotion and education among adolescent school children when compared to Twitter. Further analyses with a larger study group is warranted.

  17. Competition and Commercial Media Bias

    OpenAIRE

    Blasco, Andrea; Sobbrio, Francesco

    2011-01-01

    This paper reviews the empirical evidence on commercial media bias (i.e., advertisers influence over media accuracy) and then introduces a simple model to summarize the main elements of the theoretical literature. The analysis provides three main policy insights for media regulators: i) Media regulators should target their monitoring efforts towards news contents upon which advertisers are likely to share similar preferences; ii) In advertising industries characterized by high correlation in ...

  18. Social media as leisure culture

    OpenAIRE

    Albrechtslund, Anne-Mette Bech; Albrechtslund, Anders

    2014-01-01

    The purpose of this paper is to situate the everyday use of social media in the broader cultural practice of leisure. Whereas the use of social media has many different aims and contexts, our main idea is to emphasize how social media practices associated with leisure and playfulness rather than functionality and tasks — therefore seemingly “useless” in a strictly utilitarian sense — are practices which are meaningful. We point to certain dynamics in social media practices which we connect to...

  19. Social Media and the Army

    Science.gov (United States)

    2010-04-01

    interaction and create dialogue at the click of a mouse. Social media has had an undeniable effect on the way we live, work, and communicate... benefits of social media applications, a bevy of opportunities present themselves when accurately strategized. Planning might include— Your Strategy...in establishing a positive social media presence. Trust enables leaders to open up their organizations to social media , and training provides

  20. Documentary Media and Religious Communities

    Directory of Open Access Journals (Sweden)

    Marie-Therese Mäder

    2015-11-01

    Full Text Available The article considers four spaces where media processes involve religious communities and agents: the spaces of production, of representation, of media communication, and of distribution network and institutional framework for circulation. These three spaces systematise the research question posed to the specific source. Furthermore the concept documentary media as viewed from a semio-pragmatic perspective is introduced. Discussion of the commercial series I’m a Mormon shows how different modes define documentary media according to the three spaces.

  1. Going Public on Social Media

    Directory of Open Access Journals (Sweden)

    Greg Elmer

    2015-04-01

    Full Text Available This brief essay questions the disconnect between the financial goals of social media properties and the concerns of privacy advocates and other new media critics. It is argued that critics of social media often fail to recognize the financial imperative of social media companies, one that requires users to divulge and publicize ever more granular aspects of their daily lives, thoughts, and feelings.

  2. 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)

  3. 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

  4. [Media for 21st century--towards human communication media].

    Science.gov (United States)

    Harashima, H

    2000-05-01

    Today, with the approach of the 21st century, attention is focused on multi-media communications combining computer, visual and audio technologies. This article discusses the communication media target and the technological problems constituting the nucleus of multi-media. The communication media is becoming an environment from which no one can escape. Since the media has such a great power, what is needed now is not to predict the future technologies, but to estimate the future world and take to responsibility for future environments.

  5. TU Delft en online media

    NARCIS (Netherlands)

    Speekenbrink, R.J.H.

    2013-01-01

    Dit boek behandelt een visie op online media bij Nederlandse universiteiten. Daarbij beperk ik me tot die aspecten waarin online communicatie en/of online marketing een rol speelt. Dit boek behandelt niet de onderwijsgerelateerde aspecten van online media. Elektronische leeromgevingen, sociale media

  6. Social media and activist communication

    NARCIS (Netherlands)

    Poell, T.; van Dijck, J.; Atton, C.

    2015-01-01

    While the rise of social media has made activists much less dependent on television and mainstream newspapers, this certainly does not mean that activists have more control over the media environments in which they operate. Media power has neither been transferred to the public, nor to activists for

  7. The Media and Transformative Learning.

    Science.gov (United States)

    Palazon, Maria

    The media constitute important sources and resources for development of critical thought about the media themselves and the reality they represent. The first theories of the media were based on the concept of unidirectional communication. Later, factors such as the increasing interest in audiences and development of cultural studies caused…

  8. Media Competition and Electoral Politics

    NARCIS (Netherlands)

    Piolatto, A.; Schuett, F.

    2013-01-01

    Abstract: We build a framework linking competition in the media market to political participation, media slant, and selection of politicians. Media outlets report on the ability of candidates running for office and compete for audience through their choice of slant. Citizens derive utility from

  9. Do the Media Undermine Democracy?

    Science.gov (United States)

    Dorman, William A.

    This paper considers political reasoning within a democracy and how mass media may affect that process, as well as how the perspective and method of critical thinking may be brought to bear on the subject of media and politics. Specifically, the paper (1) discusses some ways in which the mass media may affect political reasoning; (2) offers a…

  10. Media Literacy Is the Message.

    Science.gov (United States)

    Trampiets, Frances

    1995-01-01

    Highlights the importance of using music, multimedia, video, and computers to enrich and enhance religious education, and of integrating media education into faith formation. Suggests that media literacy plays an important role in increasing awareness of the influence of mass media on society. (DJM)

  11. Social Media Empowerment (deel IV)

    NARCIS (Netherlands)

    A. Cox

    2011-01-01

    full text via link. Social media stellen mensen, merken en bedrijven in staat om zichzelf te versterken. Soms wordt optimaal gebruik gemaakt van Social Media Empowerment, bijvoorbeeld bij het versterken van de brand equity zoals bij KLM en Jillz. Soms wordt er minder goed gebruik van social media

  12. Characterizing Government Social Media Research

    DEFF Research Database (Denmark)

    Medaglia, Rony; Zheng, Lei

    2016-01-01

    As research on government social media continues to grow in quantity and scope, this area calls for mapping and systematization, in order to stimulate better-informed studies in the future. This paper draws on a comprehensive review of government social media literature in the e...... a four-point research agenda for future government social media research....

  13. Acute and chronic otitis media.

    Science.gov (United States)

    Morris, Peter S; Leach, Amanda J

    2009-12-01

    Otitis media (OM) is a common illness in young children. OM has historically been associated with frequent and severe complications. Nowadays it is usually a mild condition that often resolves without treatment. For most children, progression to tympanic membrane perforation and chronic suppurative OM is unusual (low-risk populations); this has led to reevaluation of many interventions that were used routinely in the past. Evidence from a large number of randomized controlled trials can help when discussing treatment options with families. Indigenous children in the United States, Canada, Northern Europe, Australia, and New Zealand experience more OM than other children. In some places, Indigenous children continue to suffer from the most severe forms of the disease. Communities with more than 4% of the children affected by chronic tympanic membrane perforation have a major public health problem (high-risk populations). Higher rates of invasive pneumococcal disease, pneumonia, and chronic suppurative lung disease (including bronchiectasis) are also seen. These children will often benefit from effective treatment of persistent (or recurrent) bacterial infection.

  14. Stereotypes in media and media literacy among young people

    Directory of Open Access Journals (Sweden)

    Đerić Ivana

    2006-01-01

    Full Text Available Young people, the most common consumers of media content, bear out the view that media shapes people’s lives. Therefore we must not underestimate the effect media exerts on young people’s values and behavioral patterns. Television is the medium which draws children and young people for the greatest part of their free time. Regardless whether television programs are described as positive or negative, whether they abound with stereotypes or not, it is important that young people develop a critical attitude towards them so that they may resist different forms of media manipulation. The paper discusses how stereotypes are generated and used by media and the manners in which stereotypical concepts affect young people’s attitudes. It highlights the importance of the development of media literacy which implies a critical attitude towards media images and discourses, the development of criteria for the selection and evaluation of information broadcast by media, the development of skills in interpreting and understanding stereotypical concepts and familiarity with alternative forms of media culture. The paper draws special attention to the issue of media education. The conclusion is that schools should offer media literacy as part of their curriculum and in it possible solutions to the problems discussed. .

  15. [Media, cloning, and bioethics].

    Science.gov (United States)

    Costa, S I; Diniz, D

    2000-01-01

    This article was based on an analysis of three hundred articles from mainstream Brazilian periodicals over a period of eighteen months, beginning with the announcement of the Dolly case in February 1997. There were two main objectives: to outline the moral constants in the press associated with the possibility of cloning human beings and to identify some of the moral assumptions concerning scientific research with non-human animals that were published carelessly by the media. The authors conclude that there was a haphazard spread of fear concerning the cloning of human beings rather than an ethical debate on the issue, and that there is a serious gap between bioethical reflections and the Brazilian media.

  16. Urban Media and Interfaces

    DEFF Research Database (Denmark)

    2013-01-01

    For ten weeks in 2013, nineteen eclectic students from Anthropology, Ethnology and Design formed cross-disciplinary teams to research existing practices and possible futures in Blågården. Social media is radically changing how urban space is explored, experienced and communicated. For example...... for current and potential visitors as mentioned in the social housing plan for the area. On the other hand, the area's mixed ethnicity, colorful shops and cafes are valued by city tourists and other visitors who seek authentic experiences in local contexts. Against this background, Det Gode Naboskab......, Wonderful Copenhagen and Socialsquare jointly raise these questions: What is the role of social media as interface between the area around Blågårds Plads, its local communities and (potential) visitors, considering perspectives of security, control and planning? What are the challenges and opportunities...

  17. The Mass Media

    DEFF Research Database (Denmark)

    Valentini, Chiara; Laursen, Bo

    2012-01-01

    spaces. We postulate that citizens’ levels of awareness and knowledge of EU matters depend on the EU institutions’ ability to reach European citizens directly or indirectly through a wide range of channels, including the mass media. Citizens’ participation in political debates, however, requires more......(s). The EU institutions also need to communicate frames of interpretation around political issues. In this chapter we analyse the EU institutions’ external communication and specifically their media relations efforts, and suggest improvements in view of remedying some of the legitimacy problems that the EU......This chapter deals with the EU institutions’ external communication and how it relates to the European public sphere(s). We argue that one of the preconditions for establishing a well-functioning European public sphere is that the EU institutions’ decision-making and political debates around...

  18. Culinary art in media

    Directory of Open Access Journals (Sweden)

    Radojičić Dragana

    2009-01-01

    Full Text Available The subject of diet culture is beyond the scope of this paper. Therefore, I concentrated on several examples which best illustrate the presence of culinary art and diet in media. That is, I used 72 articles from the magazine Gloria with the food subject (2006-2009. Diet and culinary arts are omnipresent in media globally. As a rule, many offers recommend recipes and items considered traditional, with a wide range of recipes offered in Serbia alone. Internet also offers many web sites with various diets and recipes. All in all, domestic readers of local journals and magazine can find a variety of fashionable recipes from all over the world, most of the time with limited instructions or groceries not easily obtained at the local market. Bon ton is also lacking while diet and food choices continue to saturate all forms of social behavior as well as recipes serving as communication within a given culture.

  19. Humanitarian Branding & the Media

    DEFF Research Database (Denmark)

    Vestergaard, Anne

    2006-01-01

    are becoming increasingly commercialized. This paper explores the use of media discourse for the communication of ethical messages by humanitarian organizations, caught, as they are, in a tension between, on the one hand, the commercial strategies of visibility and still greater dependence on the media, and......The development of corporate communication in recent years has brought about a fading of the division of labor between commercial and non-commercial organizations. While the practices of commercial organizations are becoming increasingly ethicalized, so the practices of non-profit organizations......'s branding strategies testify to a high degree of reflexivity about the conditions of what Luc Boltanski calls a Crisis of Pity. The analysis illustrates how, in the face of compassion fatigue, the organization manages to carve out a new space for itself in the marketized ethical discourse, and leads...

  20. Current iodinated contrast media

    International Nuclear Information System (INIS)

    Stacul, F.

    2001-01-01

    The number of scientific papers on iodinated contrast media is declining. Indeed, comparative trials between high-osmolality and low-osmolality agents largely showed the higher safety and tolerability of the latter, and this is no longer a matter of discussion. Only financial constraints could prevent a total conversion to low-osmolality agents. Research comparing low-osmolality (nonionic monomers, ionic dimer) and iso-osmolality contrast media (nonionic dimers) are still ongoing. Both classes of nonionic compounds proved safer than the ionic dimer. The relative merits of nonionic monomers and nonionic dimers are a matter for debate, and criteria for a selective use of different agents for different procedures could be discussed. (orig.)

  1. In medias res

    DEFF Research Database (Denmark)

    Foote, Jonathan

    2017-01-01

    nor does he begin the Trojan War ab ovo (with the egg) but always he hurries to the action and snatches the listener in medias res (into the middle of things)      Horace, Ars Poetica 145–147 Good epic poets do not commence their tale from the beginning—ab ovo (with the egg)—as Horace states......, but rather descend in medias res (into the middle of things), a reference to the Illiad opening already many years into the Trojan War. Perhaps this sentiment of plunging into the middle of action was felt by researchers in 1976 when, upon the walls of the San Lorenzo New Sacristy in Florence, they uncovered...

  2. Extracting random numbers from quantum tunnelling through a single diode.

    Science.gov (United States)

    Bernardo-Gavito, Ramón; Bagci, Ibrahim Ethem; Roberts, Jonathan; Sexton, James; Astbury, Benjamin; Shokeir, Hamzah; McGrath, Thomas; Noori, Yasir J; Woodhead, Christopher S; Missous, Mohamed; Roedig, Utz; Young, Robert J

    2017-12-19

    Random number generation is crucial in many aspects of everyday life, as online security and privacy depend ultimately on the quality of random numbers. Many current implementations are based on pseudo-random number generators, but information security requires true random numbers for sensitive applications like key generation in banking, defence or even social media. True random number generators are systems whose outputs cannot be determined, even if their internal structure and response history are known. Sources of quantum noise are thus ideal for this application due to their intrinsic uncertainty. In this work, we propose using resonant tunnelling diodes as practical true random number generators based on a quantum mechanical effect. The output of the proposed devices can be directly used as a random stream of bits or can be further distilled using randomness extraction algorithms, depending on the application.

  3. Groupwork and participatory media

    OpenAIRE

    Brailas, Alexios; Nika, Stella

    2015-01-01

    Face-to-face groupwork sessions combined with online participatory social media could be a quite promising pedagogical strategy. In this paper, we present the pedagogical design and the rationale for groupwork in a blended educational landscape. In traditional teaching, the emphasis is given on the dissemination of information, on rich content delivery by a sage on the stage. In the proposed model, the educator acts as a facilitator, as the active guide on the side of the group, delegating au...

  4. Michael Faraday, media man.

    Science.gov (United States)

    Fara, Patricia

    2006-03-01

    Michael Faraday was an enthusiastic portrait collector, and he welcomed the invention of photography not only as a possible means of recording observations accurately, but also as a method for advertising science and its practitioners. This article (which is part of the Science in the Industrial Revolution series) shows that like many eminent scientists, Faraday took advantage of the burgeoning Victorian media industry by posing in various roles.

  5. Images in Social Media

    DEFF Research Database (Denmark)

    Ørnager, Susanne; Lund, Haakon

    This book focuses on methodologies, organization and communication of digital image collection research that utilize social media content. (“Image” is here understood as cultural, conventional and commercial - stock photos - representations.) The lecture offer expert views that provide different...... fake news, image manipulation, mobile photos etc. these issues are very complex and need a publication of their own. This book should primarily be useful for students in library and information science, psychology, and computer science....

  6. The News Media Industry

    Science.gov (United States)

    2003-06-05

    into “infotainment,” with an emphasis on trivia and news of the lives of celebrities. As a result, the American public is, as media critic Mark...presented by multiple outlets is often recycled . For example, a reader of Newsweek may see a similar, if not identical, story in its sibling...teleprompter. News and entertainment have morphed into “infotainment,” with an emphasis on trivia and the lives of celebrities. Unfortunately

  7. Division Level Social Media

    Science.gov (United States)

    2015-06-12

    the lines of effort (LOE), goal, and MOE.8 The MOH story was distributed through the following social media sites: Flicker , Facebook, Twitter, and a...and shares to save a follower’s time for more popular posts or paid advertisements. One way to mitigate paying for advertising is access to better...related items, which hinders analysis for growth and ways to mitigate dwindling organic reach. Lastly, better expectation 60 management is critical

  8. Media evolution and ‘epi-technic’ digital media: Media as cultural selection mechanisms

    DEFF Research Database (Denmark)

    Olesen, Mogens

    2016-01-01

    The explosive development of new digital media technologies is often described as a media evolution but hardly ever is the concept of ‘media evolution’ taken at face value. This article takes up that challenge by combining cultural evolution theories with medium theory. The article argues that bi...

  9. Dialysis and contrast media

    International Nuclear Information System (INIS)

    Morcos, Sameh K.; Thomsen, Henrik S.; Webb, Judith A.W.

    2002-01-01

    In a previous survey we revealed uncertainty among responders about (a) whether or not to perform hemodialysis in patients with severely reduced renal function who had received contrast medium; and (b) when to perform hemodialysis in patients on regular treatment with hemodialysis or continuous ambulatory dialysis who received contrast medium. Therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and to issue guidelines. The committee performed a Medline search. Based on this, a report and guidelines were prepared. The report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy. Hemodialysis and peritoneal dialysis safely remove both iodinated and gadolinium-based contrast media. The effectiveness of hemodialysis depends on many factors including blood and dialysate flow rate, permeability of dialysis membrane, duration of hemodialysis and molecular size, protein binding, hydrophilicity, and electrical charge of the contrast medium. Generally, several hemodialysis sessions are needed to removal all contrast medium, whereas it takes 3 weeks for continuous ambulatory dialysis to remove the agent completely. There is no need to schedule the dialysis in relation to the injection of iodinated or MR contrast media or the injection of contrast agent in relation to the dialysis program. Hemodialysis does not protect poorly functioning kidneys against contrast-medium-induced nephrotoxicity. Simple guidelines are given. (orig.)

  10. Social Media Marketing

    DEFF Research Database (Denmark)

    Hollensen, Svend; Raman, Anthony

    2014-01-01

    Social media marketing can be understood as a group of Internet-based applications that build on the foundations of Web 2.0 and that then allows the creation and exchange of ‘User Generated Content’. In the ‘Bowling’ marketing world, marketers target certain customer groups and send out...... this is a very direct one-way communication approach. In a social media marketing world, the bowling metaphor does not fit anymore. On this arena marketing can be better described as playing “Pinball”: Companies serve up a “marketing ball” (brands and brand-building messages) into a dynamic and chaotic market...... environment. The “marketing ball” is then diverted and often accelerated by social media “bumpers”, which change the ball’s course in chaotic ways. Occasionally, the marketing ball will come back to the company. At this point, the firm (brand) has to use the flippers to interact and throw it back...

  11. Civic Engagement and Social Media

    DEFF Research Database (Denmark)

    The recent wave of protests, from the Arab Spring to the Occupy movement and austerity protests, have reinvigorated hopes for the democratic potential of the Internet, and particularly social media. With their popular appeal and multimodal affordances social media such as YouTube, Twitter...... and Facebook have generated both media and scholarly interest in their possibilities for granting visibility to and facilitating the organization of activism. However, the role of social media in sustaining civic engagement beyond protest and fatalism remains under-explored. How can social media contribute...... to sustaining longer-term involvement of civil society? What is the potential of social media for making available alternative social imaginaries? And what role may social media play in facilitating social change through cooperation with business? This volume offers answers to these questions by providing...

  12. Social Media in IS Literature

    DEFF Research Database (Denmark)

    Dyrby, Signe

    2013-01-01

    The phenomenon of ‘digital living’ is to a high extent influenced by the introduction of new media into society. Especially, social media are affecting the digital world of today and are setting the agenda for social connectedness in private, public and commercial networks. Based in an initial...... desire to explore a research agenda for the workings of social media in network structures a look into the literature on social media within the field of Information Systems sparked an interest in exploring a new research perspective for social media. Reviewing the IS literature it is apparent...... that the perspective of the ‘media’ as an artifact of social media has been neglected in existing literature. Based in this, this paper proposes research possibilities for investigating the ‘media’ of social media as well as some theoretical considerations that could aid the investigation. Finally, potential outcomes...

  13. Otitis media with effusion in children younger than 1 year

    Directory of Open Access Journals (Sweden)

    Renata Cantisani Di Francesco

    2016-06-01

    Full Text Available Abstract Objective: To determine the prevalence of otitis media with effusion in children younger than 1 year and its association with the season of the year, artificial feeding, environmental and perinatal factors. Methods: Retrospective study of 184 randomly included medical records from a total of 982 healthy infants evaluated for hearing screening tests. Diagnosis of otitis media with effusion was based on otoscopy (amber-gold color, fluid level, handle of malleus position, type B tympanometric curves and absence of otoacoustic emissions. Incomplete medical records or those describing acute otitis media, upper respiratory tract infections on the assessment day or in the last 3 months, neuropathies and craniofacial anomalies were excluded. Data such as gestational age, birth weight, Apgar score, type of feeding and day care attendance were compared between children with and without otitis media with effusion through likelihood tests and multivariate analysis. Results: 25.3% of 184 infants had otitis media with bilateral effusion; 9.2% had unilateral. In infants with otitis media, the following were observed: chronological age of 9.6±1.7 months; gestational age >38 weeks in 43.4% and birth weight >2500g in 48.4%. Otitis media with effusion was associated with winter/fall, artificial feeding, Apgar score <7 and day care attendance. The multivariate analysis showed that artificial feeding is the factor most often associated to otitis media with effusion. Conclusions: Otitis media with effusion was found in about one third of children younger than 1 year and was mainly associated with artificial feeding.

  14. [Otitis media with effusion in children younger than 1 year].

    Science.gov (United States)

    Di Francesco, Renata Cantisani; Barros, Vivian Boschesi; Ramos, Rafael

    2016-06-01

    To determine the prevalence of otitis media with effusion in children younger than 1 year and its association with the season of the year, artificial feeding, environmental and perinatal factors. Retrospective study of 184 randomly included medical records from a total of 982 healthy infants evaluated for hearing screening tests. Diagnosis of otitis media with effusion was based on otoscopy (amber-gold color, fluid level, handle of malleus position), type B tympanometric curves and absence of otoacoustic emissions. Incomplete medical records or those describing acute otitis media, upper respiratory tract infections on the assessment day or in the last 3 months, neuropathies and craniofacial anomalies were excluded. Data such as gestational age, birth weight, Apgar score, type of feeding and day care attendance were compared between children with and without otitis media with effusion through likelihood tests and multivariate analysis. 25.3% of 184 infants had otitis media with bilateral effusion; 9.2% had unilateral. In infants with otitis media, the following were observed: chronological age of 9.6±1.7 months; gestational age >38 weeks in 43.4% and birth weight >2,500g in 48.4%. Otitis media with effusion was associated with winter/fall, artificial feeding, Apgar score otitis media with effusion. Otitis media with effusion was found in about one third of children younger than 1 year and was mainly associated with artificial feeding. Copyright © 2015 Sociedade de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  15. Skills and Strategies for Media Education.

    Science.gov (United States)

    Thoman, Elizabeth

    1999-01-01

    To thrive in our media-saturated culture, children must become media literate and learn five lessons: media messages are constructed by a few for the many; constructions involve creative languages; different people experience the same media message differently; media are primarily profit-driven businesses; and media have embedded values and…

  16. Update on Otitis Media in Children.

    Science.gov (United States)

    Schoem, Scott R.

    1997-01-01

    This article discusses otitis media in children. It addresses risk factors for otitis media, pathogenesis, diagnosis, bacteria causing otitis media, and treatment for acute otitis media, recurrent acute otitis media, and persistent otitis media with effusion, including antibiotics, steroids, allergy control, autoinflation, mechanical ventilation,…

  17. Statistical analysis of random pulse trains

    International Nuclear Information System (INIS)

    Da Costa, G.

    1977-02-01

    Some experimental and theoretical results concerning the statistical properties of optical beams formed by a finite number of independent pulses are presented. The considered waves (corresponding to each pulse) present important spatial variations of the illumination distribution in a cross-section of the beam, due to the time-varying random refractive index distribution in the active medium. Some examples of this kind of emission are: (a) Free-running ruby laser emission; (b) Mode-locked pulse trains; (c) Randomly excited nonlinear media

  18. Media identities and media-influenced indentifications Visibility and identity recognition in the media

    Directory of Open Access Journals (Sweden)

    Víctor Fco. Sampedro Blanco

    2004-10-01

    Full Text Available The media establish, in large part, the patterns of visibility and public recognition of collective identities. We define media identities as those that are the object of production and diffusion by the media. From this discourse, the communities and individuals elaborate media-influenced identifications; that is, processes of recognition or banishment; (rearticulating the identity markers that the media offer with other cognitive and emotional sources. The generation and appropriation of the identities are subjected to a media hierarchisation that influences their normalisation or marginalisation. The identities presented by the media and assumed by the audience as part of the official, hegemonic discourse are normalised, whereas the identities and identifications formulated in popular and minority terms are marginalised. After presenting this conceptual and analytical framework, this study attempts to outline the logics that condition the presentation, on the one hand, andthe public recognition, on the other hand, of contemporary identities.

  19. Post Media Literacy: Menyaksikan Kuasa Media Bersama Michel Foucault

    Directory of Open Access Journals (Sweden)

    Iswandi Syahputra

    2017-01-01

    Full Text Available This article would like to present Michel Foucault’s idea concerning Knowledge and Power in media industry. As a contemporary intellectual, Foucault’s thought has a unique style of postmodernism. His thought had gone beyond traditional critical theory whose trying to disclose the relation of power and economic behind the ideology of media. Foucault’s thought had given new perspective in understanding how the media produce truth under tightly control process into something that seems normal. With the assumption of media has the power to create mass culture, which has to be studied critically by media literacy approach, Foucault’s thought had given new space of discursive. An alternative thought on how to estimate the work of mass media as supervisor of truth and creator of information trough normalization practice.

  20. Social Media, Traditional Media and Marketing Communication of Public Relations

    DEFF Research Database (Denmark)

    Khajeheian, Datis; Mirahmadi, Fereshteh

    2015-01-01

    Public relations are undertaking more important role in the marketing communication and advertising. The present paper reports a survey conducted in three Iranian banks’ public relations departments to understand how they use different media in their marketing communications and other related...... functions. A classification of public relations functions including fourteen functions in three categories has taken as research framework and by using a questionnaire, eight media have been asked to rank for each function, includes Television, Radio, Newspaper, Magazine, Classified Ads, Internet Websites......, Social media and finally Mobile and SMS ads. Findings show that traditional media still play a dominant role in media consumption of public relations, while new Web2.0 media consist of Mobile communications and Social networks, have never ranked better than fifth from eight. Some reasons have been argues...