WorldWideScience

Sample records for classical trajectory study

  1. Classical trajectories and quantum tunneling

    CERN Document Server

    Ivlev, B I

    2003-01-01

    The problem of inter-band tunneling in a semiconductor (Zener breakdown) in a nonstationary and homogeneous electric field is solved exactly. Using the exact analytical solution, the approximation based on classical trajectories is studied. A new mechanism of enhanced tunneling through static non-one-dimensional barriers is proposed in addition to well known normal tunneling solely described by a trajectory in imaginary time. Under certain conditions on the barrier shape and the particle energy, the probability of enhanced tunneling is not exponentially small even for non-transparent barriers, in contrast to the case of normal tunneling.

  2. Classical Trajectories and Quantum Spectra

    Science.gov (United States)

    Mielnik, Bogdan; Reyes, Marco A.

    1996-01-01

    A classical model of the Schrodinger's wave packet is considered. The problem of finding the energy levels corresponds to a classical manipulation game. It leads to an approximate but non-perturbative method of finding the eigenvalues, exploring the bifurcations of classical trajectories. The role of squeezing turns out decisive in the generation of the discrete spectra.

  3. Bohmian trajectory from the "classical" Schrödinger equation.

    Science.gov (United States)

    Sengupta, Santanu; Khatua, Munmun; Chattaraj, Pratim Kumar

    2014-12-01

    The quantum-classical correspondence is studied for a periodically driven quartic oscillator exhibiting integrable and chaotic dynamics, by studying the Bohmian trajectory of the corresponding "classical" Schrödinger equation. Phase plots and the Kolmogorov-Sinai entropy are computed and compared with the classical trajectory as well as the Bohmian trajectory obtained from the time dependent Schrödinger equation. Bohmian mechanics at the classical limit appears to mimick the behavior of a dissipative dynamical system.

  4. Decoherence and the Branching of Chaos-less Classical Trajectory

    CERN Document Server

    Ishikawa, Takuji

    2016-01-01

    This study was started to know mysterious classicality of nuclei. This time, I found a new rule for decoherence. I used a model without chaos. As a result, it was shown that not only the intersection of classical trajectories but also branching of classical trajectories are needed for decoherence. In other words, it was shown that interactions between a main system and environments have to make enough branchings of classical trajectories of the main system for decoherence.

  5. Mixed time-dependent density-functional theory/classical trajectory surface hopping study of oxirane photochemistry

    NARCIS (Netherlands)

    Tapavicza, Enrico; Tavernelli, Ivano; Rothlisberger, Ursula; Filippi, Claudia; Casida, Mark E.

    2008-01-01

    We present a mixed time-dependent density-functional theory (TDDFT)/classical trajectory surface hopping (SH) study of the photochemical ring opening in oxirane. Previous preparatory work limited to the symmetric CC ring-opening pathways of oxirane concluded that the Tamm-Dancoff approximation (TDA)

  6. HCO+ dissociation in a strong laser field: An ab initio classical trajectory study

    Science.gov (United States)

    Lee, Suk Kyoung; Li, Wen; Bernhard Schlegel, H.

    2012-05-01

    We have investigated the photodissociation of HCO+ in a strong field with a wavelength of 10 μm using ab initio molecular dynamics. Classical trajectories were calculated at three field intensities. At 2.9 × 1014 W/cm2 and phase ϕ = 0, protons have two distinct dissociation times, mainly due to the reorientation of HCO+ relative to the field direction prior to dissociation. The kinetic energy distribution at this intensity agrees with Wardlaw's wagging tail model, suggesting that dissociation occurs through barrier-suppression. At 1.7 × 1014 and 8.8 × 1013 W/cm2, barrier suppression is incomplete and the maximum kinetic energy is less than predicted by the wagging tail model.

  7. Nonadiabatic nuclear dynamics of the ammonia cation studied by surface hopping classical trajectory calculations

    Science.gov (United States)

    Belyaev, Andrey K.; Domcke, Wolfgang; Lasser, Caroline; Trigila, Giulio

    2015-03-01

    The Landau-Zener (LZ) type classical-trajectory surface-hopping algorithm is applied to the nonadiabatic nuclear dynamics of the ammonia cation after photoionization of the ground-state neutral molecule to the excited states of the cation. The algorithm employs a recently proposed formula for nonadiabatic LZ transition probabilities derived from the adiabatic potential energy surfaces. The evolution of the populations of the ground state and the two lowest excited adiabatic states is calculated up to 200 fs. The results agree well with quantum simulations available for the first 100 fs based on the same potential energy surfaces. Three different time scales are detected for the nuclear dynamics: Ultrafast Jahn-Teller dynamics between the excited states on a 5 fs time scale; fast transitions between the excited state and the ground state within a time scale of 20 fs; and relatively slow partial conversion of a first-excited-state population to the ground state within a time scale of 100 fs. Beyond 100 fs, the adiabatic electronic populations are nearly constant due to a dynamic equilibrium between the three states. The ultrafast nonradiative decay of the excited-state populations provides a qualitative explanation of the experimental evidence that the ammonia cation is nonfluorescent.

  8. Nonadiabatic nuclear dynamics of the ammonia cation studied by surface hopping classical trajectory calculations

    CERN Document Server

    Belyaev, Andrey K; Lasser, Caroline; Trigila, Giulio

    2014-01-01

    The Landau--Zener (LZ) type classical-trajectory surface-hopping algorithm is applied to the nonadiabatic nuclear dynamics of the ammonia cation after photoionization of the ground-state neutral molecule to the excited states of the cation. The algorithm employs the recently proposed formula for nonadiabatic LZ transition probabilities derived from the adiabatic potential energy surfaces. The evolution of the populations of the ground state and the two lowest excited adiabatic states is calculated up to 200 fs. The results agree well with quantum simulations available for the first 100 fs based on the same potential energy surfaces. Four different time scales are detected for the nuclear dynamics: Ultrafast Jahn--Teller dynamics between the excited states on a 5 fs time scale; fast transitions between the excited state and the ground state within a time scale of 20 fs; relatively slow partial conversion of a first-excited-state population to the ground state within a time scale of 100 fs; and nearly constant ...

  9. Simulation of molecular transitions using classical trajectories

    Energy Technology Data Exchange (ETDEWEB)

    Donoso, A.; Martens, C. C. [University of California, California (United States)

    2001-03-01

    In the present work, we describe the implementation of a semiclassical method to study physical-chemical processes in molecular systems where electronic state transitions and quantum coherence play a dominant role. The method is based on classical trajectory propagation on the underlying coupled electronic surfaces and is derived from the semiclassical limit of the quantum Liouville equation. Unlike previous classical trajectory-based methods, quantum electronic coherence are treated naturally within this approach as complex weighted trajectory ensembles propagating on the average electronic surfaces. The method is tested on a model problem consisting of one-dimensional motion on two crossing electronic surfaces. Excellent agreement is obtained when compared to the exact results obtained by wave packet propagation. The method is applied to model quantum wave packet interferometry, where two wave packets, differing only in a relative phase, collide in the region where the two electronic surfaces cross. The dependence of the resulting population transfer on the initial relative phase of the wave packets is perfectly captured by our classical trajectory method. Comparison with an alternative method, surface hopping, shows that our approach is appropriate for modelling quantum interference phenomena. [Spanish] En este trabajo se describe la implementacion de un metodo semiclasico para estudiar procesos fisicos-quimicos en sistemas moleculares donde las transiciones entre estados electronicos y las coherencias cuanticas juegan un papel predominante. El metodo se basa en la propagacion de trayectorias clasicas sobre las correspondientes superficies electronicas acopladas y se deriva a partir del limite semiclasico de la ecuacion cuantica de Liouville. A diferencia de metodos previos basados en trayectoria clasica, dentro de este esquema, las coherencias electronicas cuanticas son tratadas de manera natural como ensamble de trayectorias con pesos complejos, moviendose en

  10. Scattering of fast N-2 from Pd(111) : A classical trajectory study

    NARCIS (Netherlands)

    Schlathölter, Thomas; Vicanek, M; Heiland, W

    1997-01-01

    Molecular nitrogen is well known for its chemical inactivity. Experimental results for grazing incidence N-2 scattering from Pd(111) surfaces in the keV range also reveal negligible influences of electronical processes on molecular fragmentation. Therefore, we carry out gn appropriate classical trea

  11. Classical Trajectories for two Ring-Shaped Potentials

    CERN Document Server

    Kibler, M R; Winternitz, Pavel

    1992-01-01

    This paper deals with the classical trajectories for two super-integrable systems: a system known in quantum chemistry as the Hartmann system and a system of potential use in quantum chemistry and nuclear physics. Both systems correspond to ring-shaped potentials. They admit two maximally super-integrable systems as limiting cases, viz, the isotropic harmonic oscillator system and the Coulomb-Kepler system in three dimensions. The planarity of the trajectories is studied in a systematic way. In general, the trajectories are quasi-periodic rather than periodic. A constraint condition allows to pass from quasi-periodic motions to periodic ones. When written in a quantum mechanical context, this constraint condition leads to new accidental degeneracies for the two systems studied.

  12. Effects of complex parameters on classical trajectories of Hamiltonian systems

    Indian Academy of Sciences (India)

    Asiri Nanayakkara; Thilagarajah Mathanaranjan

    2014-06-01

    Anderson et al have shown that for complex energies, the classical trajectories of real quartic potentials are closed and periodic only on a discrete set of eigencurves. Moreover, recently it was revealed that when time is complex $t(t = t_r e^{i_})$, certain real Hermitian systems possess close periodic trajectories only for a discrete set of values of . On the other hand, it is generally true that even for real energies, classical trajectories of non-PT symmetric Hamiltonians with complex parameters are mostly non-periodic and open. In this paper, we show that for given real energy, the classical trajectories of complex quartic Hamiltonians $H = p^2 + ax^4 + bx^k$ (where is real, is complex and = 1 or 2) are closed and periodic only for a discrete set of parameter curves in the complex -plane. It was further found that given complex parameter , the classical trajectories are periodic for a discrete set of real energies (i.e., classical energy gets discretized or quantized by imposing the condition that trajectories are periodic and closed). Moreover, we show that for real and positive energies (continuous), the classical trajectories of complex Hamiltonian $H = p^2 + x^4$, ($= _r$ e$^{i}$) are periodic when $ = 4 \\tan^{−1}$[($n/(2m + n)$)] for $\\forall n$ and $m \\mathbb{Z}$.

  13. Study of the H+HS reaction on a newly built potential energy surface using the quasi-classical trajectory method

    Institute of Scientific and Technical Information of China (English)

    Bai Meng-Meng; Ge Mei-Hua; Yang Huan; Zheng Yu-Jun

    2012-01-01

    The quasi-classical trajectory (QCT) method is used to study the H+HS reaction on a newly built potential energy surface (PES) of the triplet state of H2S (3A") in a collision energy range of 0-60 kcal/mol.Both scalar properties,such as the reaction probability and the integral cross section (ICS),and the vector properties,such as the angular distribution between the relative velocity vector of the reactant and that of the product,etc.,are investigated using the QCT method.It is found that the ICSs obtained by the QCT method and the quantum mechanical (QM) method accord well with each other.In addition,the distribution for the product vibrational states is cold,while that for the product rotational states is hot for both reaction channels in the whole energy range studied here.

  14. Study of the H+HS reaction on a newly built potential energy surface using the quasi-classical trajectory method

    Science.gov (United States)

    Bai, Meng-Meng; Ge, Mei-Hua; Yang, Huan; Zheng, Yu-Jun

    2012-12-01

    The quasi-classical trajectory (QCT) method is used to study the H+HS reaction on a newly built potential energy surface (PES) of the triplet state of H2S (3A″) in a collision energy range of 0-60 kcal/mol. Both scalar properties, such as the reaction probability and the integral cross section (ICS), and the vector properties, such as the angular distribution between the relative velocity vector of the reactant and that of the product, etc., are investigated using the QCT method. It is found that the ICSs obtained by the QCT method and the quantum mechanical (QM) method accord well with each other. In addition, the distribution for the product vibrational states is cold, while that for the product rotational states is hot for both reaction channels in the whole energy range studied here.

  15. Trajectory description of the quantum–classical transition for wave packet interference

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Chia-Chun, E-mail: ccchou@mx.nthu.edu.tw

    2016-08-15

    The quantum–classical transition for wave packet interference is investigated using a hydrodynamic description. A nonlinear quantum–classical transition equation is obtained by introducing a degree of quantumness ranging from zero to one into the classical time-dependent Schrödinger equation. This equation provides a continuous description for the transition process of physical systems from purely quantum to purely classical regimes. In this study, the transition trajectory formalism is developed to provide a hydrodynamic description for the quantum–classical transition. The flow momentum of transition trajectories is defined by the gradient of the action function in the transition wave function and these trajectories follow the main features of the evolving probability density. Then, the transition trajectory formalism is employed to analyze the quantum–classical transition of wave packet interference. For the collision-like wave packet interference where the propagation velocity is faster than the spreading speed of the wave packet, the interference process remains collision-like for all the degree of quantumness. However, the interference features demonstrated by transition trajectories gradually disappear when the degree of quantumness approaches zero. For the diffraction-like wave packet interference, the interference process changes continuously from a diffraction-like to collision-like case when the degree of quantumness gradually decreases. This study provides an insightful trajectory interpretation for the quantum–classical transition of wave packet interference.

  16. Quasi-classical trajectory study of the reaction H' + HS on a new ab initio potential energy surface H2S (3A")

    Indian Academy of Sciences (India)

    Jinghan Zou; Shuhui Yin; Dan Wu; Mingxing Guo; Xuesong Xu; Hong Gao; Lei Li; Li Che

    2013-09-01

    Theoretical study on the dynamics of reactions H' + HS( = 0, = 0)→H2 + S and H' + HS( =0, = 0)→ H + H'S is performed with quasi-classical trajectory (QCT) method on a new ab initio potential energy surface for the lowest triplet state of H2S (3A") constructed in 2012 by Lv et al. The QCT-calculated reaction integral cross-sections are in good agreement with previous quantum wave packet results over the collision energy range of 0-50 kcal/mol. Both the abstraction and exchange reactions are governed by direct reaction dynamics and the trajectories follow the minimum energy path. The rotational angular momentum vector ' of products in the two reaction channels are not only aligned perpendicular to scattering plane but also oriented along the negative direction of the axis perpendicular to the scattering plane. With the increase in collision energy, the variation trends of product polarization in the two reaction channels are different and that may be attributed to the obviously different characteristic of the two channels on the potential energy surface.

  17. Locating transition states using double-ended classical trajectories

    CERN Document Server

    Matro, A; Doll, J D

    1994-01-01

    In this paper we present a method for locating transition states and higher-order saddles on potential energy surfaces using double-ended classical trajectories. We then apply this method to 7- and 8-atom Lennard-Jones clusters, finding one previously unreported transition state for the 7-atom cluster and two for the 8-atom cluster.

  18. Photodissociation of CCH: Classical trajectory calculations involving seven electronic states

    Science.gov (United States)

    Apaydın, Gökşin; Fink, William H.; Jackson, William M.

    2004-11-01

    The photodissociation dynamics of ethynyl radical, C2H, involving seven electronic states is studied by classical trajectory calculations. Initial values of the trajectories are selected based on relative absorption intensities calculated by Mebel et al. The energies and the derivatives are interpolated by three-dimensional cubic spline interpolator using an extended data pool. Mean square errors and standard deviations in interpolation of energies for 450 data points are found to be in the range 3.1×10-6-1.4×10-5 and 1.7×10-3-3.8×10-3 hartrees, respectively. The photofragments of C2 and H are produced mainly in the X 1Σg+, a 3Πu, b 3Σg-, c 3Σu+, A 1Πu, B 1Δg electronic states of C2 as product. The avoided crossings do not appear to be in the main dissociation pathways. The internal distributions are in good accord with the experimental results where comparison is possible, suggesting that the fragmentation mechanism of C2H2 into C2 and H is a two step process involving C2H radical as an intermediate with a life time long enough to allow complete collection of the phase space in the experiments.

  19. A model for explaining fusion suppression using classical trajectory method

    Science.gov (United States)

    Phookan, C. K.; Kalita, K.

    2015-01-01

    We adopt a semi-classical approach for explanation of projectile breakup and above barrier fusion suppression for the reactions 6Li+152Sm and 6Li+144Sm. The cut-off impact parameter for fusion is determined by employing quantum mechanical ideas. Within this cut-off impact parameter for fusion, the fraction of projectiles undergoing breakup is determined using the method of classical trajectory in two-dimensions. For obtaining the initial conditions of the equations of motion, a simplified model of the 6Li nucleus has been proposed. We introduce a simple formula for explanation of fusion suppression. We find excellent agreement between the experimental and calculated fusion cross section. A slight modification of the above formula for fusion suppression is also proposed for a three-dimensional model.

  20. A model for explaining fusion suppression using classical trajectory method

    Directory of Open Access Journals (Sweden)

    Phookan C. K.

    2015-01-01

    Full Text Available We adopt a semi-classical approach for explanation of projectile breakup and above barrier fusion suppression for the reactions 6Li+152Sm and 6Li+144Sm. The cut-off impact parameter for fusion is determined by employing quantum mechanical ideas. Within this cut-off impact parameter for fusion, the fraction of projectiles undergoing breakup is determined using the method of classical trajectory in two-dimensions. For obtaining the initial conditions of the equations of motion, a simplified model of the 6Li nucleus has been proposed. We introduce a simple formula for explanation of fusion suppression. We find excellent agreement between the experimental and calculated fusion cross section. A slight modification of the above formula for fusion suppression is also proposed for a three-dimensional model.

  1. Electron impact double ionization of helium from classical trajectory calculations

    CERN Document Server

    Geyer, T

    2004-01-01

    With a recently proposed quasiclassical ansatz [Geyer and Rost, J. Phys. B 35 (2002) 1479] it is possible to perform classical trajectory ionization calculations on many electron targets. The autoionization of the target is prevented by a M\\o{}ller type backward--forward propagation scheme and allows to consider all interactions between all particles without additional stabilization. The application of the quasiclassical ansatz for helium targets is explained and total and partially differential cross sections for electron impact double ionization are calculated. In the high energy regime the classical description fails to describe the dominant TS1 process, which leads to big deviations, whereas for low energies the total cross section is reproduced well. Differential cross sections calculated at 250 eV await their experimental confirmation.

  2. Photon trajectories, anomalous velocities, and weak measurements: A classical interpretation

    CERN Document Server

    Bliokh, Konstantin Y; Nori, Franco

    2013-01-01

    Recently, Kocsis et al. reported the observation of "average trajectories of single photons" in a two-slit interference experiment [Science 332, 1170 (2011)]. This was possible by using the quantum weak-measurements method, which implies averaging over many events, i.e., in fact, a multi-photon limit of classical optics. We give a classical-optics interpretation to this experiment and other related problems. It appears that weak measurements of the local momentum of photons made by Kocsis et al. represent measurements of the Poynting vector in an optical field. We consider both the real and imaginary parts of the local momentum, and show that their measurements have been realized in classical optics using small probe particles. We also examine the appearance of "anomalous" values of the local momentum: either negative (backflow) or exceeding the wavenumber (superluminal propagation). These features appear to be closely related to vortices and evanescent waves. Finally, we revisit a number of older works and f...

  3. The effect of zero-point energy differences on the isotope dependence of the formation of ozone: a classical trajectory study.

    Science.gov (United States)

    Schinke, Reinhard; Fleurat-Lessard, Paul

    2005-03-01

    The effect of zero-point energy differences (DeltaZPE) between the possible fragmentation channels of highly excited O(3) complexes on the isotope dependence of the formation of ozone is investigated by means of classical trajectory calculations and a strong-collision model. DeltaZPE is incorporated in the calculations in a phenomenological way by adjusting the potential energy surface in the product channels so that the correct exothermicities and endothermicities are matched. The model contains two parameters, the frequency of stabilizing collisions omega and an energy dependent parameter Delta(damp), which favors the lower energies in the Maxwell-Boltzmann distribution. The stabilization frequency is used to adjust the pressure dependence of the absolute formation rate while Delta(damp) is utilized to control its isotope dependence. The calculations for several isotope combinations of oxygen atoms show a clear dependence of relative formation rates on DeltaZPE. The results are similar to those of Gao and Marcus [J. Chem. Phys. 116, 137 (2002)] obtained within a statistical model. In particular, like in the statistical approach an ad hoc parameter eta approximately 1.14, which effectively reduces the formation rates of the symmetric ABA ozone molecules, has to be introduced in order to obtain good agreement with the measured relative rates of Janssen et al. [Phys. Chem. Chem. Phys. 3, 4718 (2001)]. The temperature dependence of the recombination rate is also addressed.

  4. Quasi-classical trajectory study of the reaction N(4S) + H2 and its reverse reaction: Role of initial vibrational and rotational excitations in chemical stereodynamics

    Indian Academy of Sciences (India)

    Juan Zhang; Shunle Dong

    2013-07-01

    To investigate the effects of reagent vibrational and rotational states on the stereodynamical properties of the N(4S) + H2(, )→NH + H reaction and its reverse reaction of H(2S) + NH(, )→N(4S) + H2, we reported a detailed quasiclassical trajectory study using the 4A" double many-body expansion potential energy surface and at the collision energy of 35 kcal/mol. The density distribution of (r) as a function of the angle between and ', and that of (r) as a function of the dihedral angle between the plane containing -' and the plane containing '- ', the normal differential cross-sections as well as the averaged product rotational alignment parameter 〈 2('.) 〉 are calculated and reported. Comparison between the two reactions has showed that the degrees of alignment and orientation of products related to reagent rovibrational state have marked differences for the two reactive systems.

  5. Classical trajectory simulations of post-transition state dynamics

    Science.gov (United States)

    Lourderaj, Upakarasamy; Park, Kyoyeon; Hase, William L.

    Classical chemical dynamics simulations of post-transition state dynamics are reviewed. Most of the simulations involve direct dynamics for which the potential energy and gradient are obtained directly from an electronic structure theory. The chemical reaction attributes and chemical systems presented are product energy partitioning for Cl- ··· CH3Br → ClCH3 + Br- and C2H5F → C2H4 + HF dissociation, non-RRKM dynamics for cyclopropane stereomutation and the Cl- ··· CH3Cl complexes mediating the Cl- + CH3Cl SN2 nucleophilic substitution reaction, and non-IRC dynamics for the OH- + CH3F and F- + CH3OOH chemical reactions. These studies illustrate the important role of chemical dynamics simulations in understanding atomic-level reaction dynamics and interpreting experiments. They also show that widely used paradigms and model theories for interpreting reaction kinetics and dynamics are often inaccurate and are not applicable.

  6. Classical trajectory Monte Carlo investigation for Lorentz ionization of H (1s)

    Institute of Scientific and Technical Information of China (English)

    He Bin; Wang Jian-Guo; Liu Chun-Lei

    2013-01-01

    Lorentz ionization of H(1s) is investigated by classical trajectory Monte Carlo (CTMC) simulation.The effect of the transverse magnetic field on the considered process is analyzed in terms of the time evolution of interactions in the system,total electron energy,and electron trajectories.A classical mechanism for the ionization is found,where the variation of the kinetic energy of the nuclei is found to be important in the process.Compared with the results of tunneling ionization,the classical mechanism becomes more and more important with the increase of the velocity of the H-atom or the strength of the magnetic field.

  7. Classical stochastic measurement trajectories: Bosonic atomic gases in an optical cavity and quantum measurement backaction

    Science.gov (United States)

    Lee, Mark D.; Ruostekoski, Janne

    2014-08-01

    We formulate computationally efficient classical stochastic measurement trajectories for a multimode quantum system under continuous observation. Specifically, we consider the nonlinear dynamics of an atomic Bose-Einstein condensate contained within an optical cavity subject to continuous monitoring of the light leaking out of the cavity. The classical trajectories encode within a classical phase-space representation a continuous quantum measurement process conditioned on a given detection record. We derive a Fokker-Planck equation for the quasiprobability distribution of the combined condensate-cavity system. We unravel the dynamics into stochastic classical trajectories that are conditioned on the quantum measurement process of the continuously monitored system. Since the dynamics of a continuously measured observable in a many-atom system can be closely approximated by classical dynamics, the method provides a numerically efficient and accurate approach to calculate the measurement record of a large multimode quantum system. Numerical simulations of the continuously monitored dynamics of a large atom cloud reveal considerably fluctuating phase profiles between different measurement trajectories, while ensemble averages exhibit local spatially varying phase decoherence. Individual measurement trajectories lead to spatial pattern formation and optomechanical motion that solely result from the measurement backaction. The backaction of the continuous quantum measurement process, conditioned on the detection record of the photons, spontaneously breaks the symmetry of the spatial profile of the condensate and can be tailored to selectively excite collective modes.

  8. Classical trajectory perspective of atomic ionization in strong laser fields semiclassical modeling

    CERN Document Server

    Liu, Jie

    2014-01-01

    The ionization of atoms and molecules in strong laser fields is an active field in modern physics and has versatile applications in such as attosecond physics, X-ray generation, inertial confined fusion (ICF), medical science and so on. Classical Trajectory Perspective of Atomic Ionization in Strong Laser Fields covers the basic concepts in this field and discusses many interesting topics using the semiclassical model of classical trajectory ensemble simulation, which is one of the most successful ionization models and has the advantages of a clear picture, feasible computing and accounting for many exquisite experiments quantitatively. The book also presents many applications of the model in such topics as the single ionization, double ionization, neutral atom acceleration and other timely issues in strong field physics, and delivers useful messages to readers with presenting the classical trajectory perspective on the strong field atomic ionization. The book is intended for graduate students and researchers...

  9. Quasi-bound complexes in collisions of different linear molecules: Classical trajectory study of their manifestations in rotational relaxation and spectral line broadening

    Science.gov (United States)

    Ivanov, Sergey V.

    2016-07-01

    Stable bimolecular complexes (tightly bound dimers) in the gas phase are usually created during third body stabilization of their unstable precursors-quasi-bound complexes (QCs). The latter can arise under the condition that at least one of the colliding partners has an internal degree of freedom. In this article, the principal difference between "orbitings" and QCs is demonstrated in the classical nonreactive scattering picture. Additionally, fractions of QCs in binary collisions of different linear molecules are compared. Also in the article the influence of QCs on rotational R-T relaxation and on vibration-rotational spectral line broadening is discussed. Explicit formulae shedding light on the QCs contribution to the R-T relaxation cross section and the line width and shift are presented. The obtained results emphasize the need for including QCs in every theoretical modeling of spectroscopic manifestation of intermolecular interactions. Besides the topics above, the possible manifestation of non-impact effects in the central regions of spectral lines due to QCs is stated. And finally, special consideration is given to the problem of adequate simulation of QCs formation at different pressures.

  10. Zero-point energy constraint in quasi-classical trajectory calculations.

    Science.gov (United States)

    Xie, Zhen; Bowman, Joel M

    2006-04-27

    A method to constrain the zero-point energy in quasi-classical trajectory calculations is proposed and applied to the Henon-Heiles system. The main idea of this method is to smoothly eliminate the coupling terms in the Hamiltonian as the energy of any mode falls below a specified value.

  11. A model for explaining fusion suppression using the classical trajectory method

    Science.gov (United States)

    Phookan, C. K.; Kalita, K.

    2013-12-01

    A two-dimensional classical trajectory model is used to explain the projectile breakup and above-barrier fusion suppression for the reactions 6Li+209Bi, 6Li+152Sm and 6Li+144Sm. To obtain the initial conditions of the equations of motion, a simplified model of the 6Li nucleus has been developed. Numerical solutions of the equations lead to the classification of orbits into breakup and no-breakup trajectories. The breakup fraction is studied as a function of the impact parameter. Using quantum mechanical arguments, the cut-off impact parameter for fusion is determined by proposing a sharp cut-off model which assumes that there is an angular momentum limit to fusion. We introduce a simple formula for the explanation of fusion suppression, according to which fusion suppression is given by the average of the breakup fractions evaluated at impact parameters ranging from head-on collision up to the cut-off impact parameter. We find that there is excellent agreement between the experimental fusion cross section (σexp) and the calculated fusion cross section (σcal) for the systems studied.

  12. The Biharmonic Oscillator and Asymmetric Linear Potentials: From Classical Trajectories to Momentum-Space Probability Densities in the Extreme Quantum Limit

    Science.gov (United States)

    Ruckle, L. J.; Belloni, M.; Robinett, R. W.

    2012-01-01

    The biharmonic oscillator and the asymmetric linear well are two confining power-law-type potentials for which complete bound-state solutions are possible in both classical and quantum mechanics. We examine these problems in detail, beginning with studies of their trajectories in position and momentum space, evaluation of the classical probability…

  13. Calculation Of Change-Changing Cross Sections Of IONS Or Atoms Colliding With Fast IONS Using The Classical Trajectory Method

    Energy Technology Data Exchange (ETDEWEB)

    Kaganovich, I. D., Shnidman, Ariel, Mebane, Harrison, Davidson, R.C.

    2008-10-10

    Evaluation of ion-atom charge-changing cross sections is needed for many accelerator applications. A classical trajectory Monte Carlo (CTMC) simulation has been used to calculate ionization and charge exchange cross sections. For benchmarking purposes, an extensive study has been performed for the simple case of hydrogen and helium targets in collisions with various ions. Despite the fact that the simulation only accounts for classical mechanics, the calculations are comparable to experimental results for projectile velocities in the region corresponding to the vicinity of the maximum cross section. Shortcomings of the CTMC method for multielectron target atoms are discussed.

  14. Dividing line between quantum and classical trajectories in a measurement problem: Bohmian time constant.

    Science.gov (United States)

    Nassar, Antonio B; Miret-Artés, Salvador

    2013-10-11

    This Letter proposes an answer to a challenge posed by Bell on the lack of clarity in regards to the dividing line between the quantum and classical regimes in a measurement problem. To this end, a generalized logarithmic nonlinear Schrödinger equation is proposed to describe the time evolution of a quantum dissipative system under continuous measurement. Within the Bohmian mechanics framework, a solution to this equation reveals a novel result: it displays a time constant that should represent the dividing line between the quantum and classical trajectories. It is shown that continuous measurements and damping not only disturb the particle but compel the system to converge in time to a Newtonian regime. While the width of the wave packet may reach a stationary regime, its quantum trajectories converge exponentially in time to classical trajectories. In particular, it is shown that damping tends to suppress further quantum effects on a time scale shorter than the relaxation time of the system. If the initial wave packet width is taken to be equal to 2.8×10(-15) m (the approximate size of an electron), the Bohmian time constant is found to have an upper limit, i.e., τ(Bmax)=10(-26) s.

  15. State-specific tunneling lifetimes from classical trajectories: H-atom dissociation in electronically excited pyrrole

    Science.gov (United States)

    Xie, Weiwei; Domcke, Wolfgang; Farantos, Stavros C.; Grebenshchikov, Sergy Yu.

    2016-03-01

    A trajectory method of calculating tunneling probabilities from phase integrals along straight line tunneling paths, originally suggested by Makri and Miller [J. Chem. Phys. 91, 4026 (1989)] and recently implemented by Truhlar and co-workers [Chem. Sci. 5, 2091 (2014)], is tested for one- and two-dimensional ab initio based potentials describing hydrogen dissociation in the 1B1 excited electronic state of pyrrole. The primary observables are the tunneling rates in a progression of bending vibrational states lying below the dissociation barrier and their isotope dependences. Several initial ensembles of classical trajectories have been considered, corresponding to the quasiclassical and the quantum mechanical samplings of the initial conditions. It is found that the sampling based on the fixed energy Wigner density gives the best agreement with the quantum mechanical dissociation rates.

  16. Semiclassical approach to mesoscopic systems classical trajectory correlations and wave interference

    CERN Document Server

    Waltner, Daniel

    2012-01-01

    This volume describes mesoscopic systems with classically chaotic dynamics using semiclassical methods which combine elements of classical dynamics and quantum interference effects. Experiments and numerical studies show that Random Matrix Theory (RMT) explains physical properties of these systems well. This was conjectured more than 25 years ago by Bohigas, Giannoni and Schmit for the spectral properties. Since then, it has been a challenge to understand this connection analytically.  The author offers his readers a clearly-written and up-to-date treatment of the topics covered. He extends previous semiclassical approaches that treated spectral and conductance properties. He shows that RMT results can in general only be obtained semiclassically when taking into account classical configurations not considered previously, for example those containing multiply traversed periodic orbits. Furthermore, semiclassics is capable of describing effects beyond RMT. In this context he studies the effect of a non-zero Eh...

  17. Classic and Golli Myelin Basic Protein have distinct developmental trajectories in human visual cortex.

    Science.gov (United States)

    Siu, Caitlin R; Balsor, Justin L; Jones, David G; Murphy, Kathryn M

    2015-01-01

    Traditionally, myelin is viewed as insulation around axons, however, more recent studies have shown it also plays an important role in plasticity, axonal metabolism, and neuroimmune signaling. Myelin is a complex multi-protein structure composed of hundreds of proteins, with Myelin Basic Protein (MBP) being the most studied. MBP has two families: Classic-MBP that is necessary for activity driven compaction of myelin around axons, and Golli-MBP that is found in neurons, oligodendrocytes, and T-cells. Furthermore, Golli-MBP has been called a "molecular link" between the nervous and immune systems. In visual cortex specifically, myelin proteins interact with immune processes to affect experience-dependent plasticity. We studied myelin in human visual cortex using Western blotting to quantify Classic- and Golli-MBP expression in post-mortem tissue samples ranging in age from 20 days to 80 years. We found that Classic- and Golli-MBP have different patterns of change across the lifespan. Classic-MBP gradually increases to 42 years and then declines into aging. Golli-MBP has early developmental changes that are coincident with milestones in visual system sensitive period, and gradually increases into aging. There are three stages in the balance between Classic- and Golli-MBP expression, with Golli-MBP dominating early, then shifting to Classic-MBP, and back to Golli-MBP in aging. Also Golli-MBP has a wave of high inter-individual variability during childhood. These results about cortical MBP expression are timely because they compliment recent advances in MRI techniques that produce high resolution maps of cortical myelin in normal and diseased brain. In addition, the unique pattern of Golli-MBP expression across the lifespan suggests that it supports high levels of neuroimmune interaction in cortical development and in aging.

  18. Classic and Golli Myelin Basic Protein have distinct developmental trajectories in human visual cortex

    Directory of Open Access Journals (Sweden)

    Caitlin R Siu

    2015-04-01

    Full Text Available Traditionally myelin is viewed as insulation around axons however more recent studies have shown it plays an important role in plasticity, axonal metabolism and neuroimmune signalling. Myelin is a complex multi-protein structure composed of hundreds of proteins, with Myelin Basic Protein (MBP being the most studied. MBP has two families: Classic-MBP that is necessary for activity driven compaction of myelin around axons, and Golli-MBP that is found in neurons, oligodendrocytes, and T cells, and has been called a 'molecular link' between the nervous and immune systems. In visual cortex myelin proteins interact with immune processes to affect experience-dependent plasticity. We studied myelin in human visual cortex using Western blotting to quantify Classic- and Golli-MBP expression in post-mortem tissue samples ranging in age from 20 days to 80 years. We found that Classic- and Golli-MBP have different patterns of change across the lifespan: Classic-MBP gradually increases to 42 years and then declines into aging; Golli-MBP has changes that are coincident with milestones in visual system sensitive period, before gradually increasing into aging. There are 3 stages in the balance between Classic- and Golli-MBP expression, with Golli-MBP dominating early, then shifting to Classic-MBP, and back to Golli-MBP in aging. Also Golli-MBP has a wave of high inter-individual variability during childhood. These results about cortical MBP expression are timely because they compliment recent advances in MRI techniques that produce high resolution maps of cortical myelin in normal and diseased brain. In addition the unique pattern of Golli-MBP expression across the lifespan suggests that it supports high levels of neuroimmune interaction in cortical development and in aging.

  19. Citation classics in periodontology: a controlled study.

    Science.gov (United States)

    Nieri, Michele; Saletta, Daniele; Guidi, Luisa; Buti, Jacopo; Franceschi, Debora; Mauro, Saverio; Pini-Prato, Giovanpaolo

    2007-04-01

    The aims of this study were to identify the most cited articles in Periodontology published from January 1990 to March 2005; and to analyse the differences between citation Classics and less cited articles. The search was carried out in four international periodontal journals: Journal of Periodontology, Journal of Clinical Periodontology, International Journal of Periodontics and Restorative Dentistry and Journal of Periodontal Research. The Classics, that are articles cited at least 100 times, were identified using the Science Citation Index database. From every issue of the journals that contained a Classic, another article was randomly selected and used as a Control. Fifty-five Classics and 55 Controls were identified. Classic articles were longer, used more images, had more authors, and contained more self-references than Controls. Moreover Classics had on the average a bigger sample size, often dealt with etiopathogenesis and prognosis, but were rarely controlled or randomized studies. Classic articles play an instructive role, but are often non-Controlled studies.

  20. A STUDY OF SHUTTLECOCK'S TRAJECTORY IN BADMINTON

    Directory of Open Access Journals (Sweden)

    Yung-Jen Chen

    2009-12-01

    Full Text Available The main purpose of this study was to construct and validate a motion equation for the flight of the badminton and to find the relationship between the air resistance force and a shuttlecock's speed. This research method was based on motion laws of aerodynamics. It applied aerodynamic theories to construct motion equation of a shuttlecock's flying trajectory under the effects of gravitational force and air resistance force. The result showed that the motion equation of a shuttlecock's flight trajectory could be constructed by determining the terminal velocity. The predicted shuttlecock trajectory fitted the measured data fairly well. The results also revealed that the drag force was proportional to the square of a shuttlecock velocity. Furthermore, the angle and strength of a stroke could influence trajectory. Finally, this study suggested that we could use a scientific approach to measure a shuttlecock's velocity objectively when testing the quality of shuttlecocks. And could be used to replace the traditional subjective method of the Badminton World Federation based on players' striking shuttlecocks, as well as applying research findings to improve professional knowledge of badminton player training

  1. Semiclassical approach to mesoscopic systems. Classical trajectory correlations and wave interface

    Energy Technology Data Exchange (ETDEWEB)

    Waltner, Daniel [Regensburg Univ. (Germany). Institut fuer Theoretische Physik

    2012-07-01

    This volume describes mesoscopic systems with classically chaotic dynamics using semiclassical methods which combine elements of classical dynamics and quantum interference effects. Experiments and numerical studies show that Random Matrix Theory (RMT) explains physical properties of these systems well. This was conjectured more than 25 years ago by Bohigas, Giannoni and Schmit for the spectral properties. Since then, it has been a challenge to understand this connection analytically. The author offers his readers a clearly-written and up-to-date treatment of the topics covered. He extends previous semiclassical approaches that treated spectral and conductance properties. He shows that RMT results can in general only be obtained semiclassically when taking into account classical configurations not considered previously, for example those containing multiply traversed periodic orbits. Furthermore, semiclassics is capable of describing effects beyond RMT. In this context he studies the effect of a non-zero Ehrenfest time, which is the minimal time needed for an initially spatially localized wave packet to show interference. He derives its signature on several quantities characterizing mesoscopic systems, e. g. dc and ac conductance, dc conductance variance, n-pair correlation functions of scattering matrices and the gap in the density of states of Andreev billiards. (orig.)

  2. Milgram's Obedience Study: A Contentious Classic Reinterpreted

    Science.gov (United States)

    Griggs, Richard A.

    2017-01-01

    Given the many older criticisms of Milgram's obedience study and the more damning recent criticisms based on analyses of materials available in the Milgram archives at Yale, this study has become a contentious classic. Yet, current social psychology textbooks present it as an uncontentious classic, with no coverage of the recent criticisms and…

  3. Extracting trajectory equations of classical periodic orbits from the quantum eigenmodes in two-dimensional integrable billiards

    Science.gov (United States)

    Hsieh, Y. H.; Yu, Y. T.; Tuan, P. H.; Tung, J. C.; Huang, K. F.; Chen, Y. F.

    2017-02-01

    The trajectory equations for classical periodic orbits in the equilateral-triangular and circular billiards are systematically extracted from quantum stationary coherent states. The relationship between the phase factors of quantum stationary coherent states and the initial positions of classical periodic orbits is analytically derived. In addition, the stationary coherent states with noncoprime parametric numbers are shown to correspond to the multiple periodic orbits, which cannot be explicable in the one-particle picture. The stationary coherent states are further verified to be linked to the resonant modes that are generally observed in the experimental wave system excited by a localized and unidirectional source. The excellent agreement between the resonant modes and the stationary coherent states not only manifests the importance of classical features in experimental systems but also paves the way to manipulate the mesoscopic wave functions localized on the periodic orbits for applications.

  4. Mixed quantum/classical investigation of the photodissociation of NH3(A) and a practical method for maintaining zero-point energy in classical trajectories.

    Science.gov (United States)

    Bonhommeau, David; Truhlar, Donald G

    2008-07-07

    The photodissociation dynamics of ammonia upon excitation of the out-of-plane bending mode (mode nu(2) with n(2)=0,[ellipsis (horizontal)],6 quanta of vibration) in the A electronic state is investigated by means of several mixed quantum/classical methods, and the calculated final-state properties are compared to experiments. Five mixed quantum/classical methods are tested: one mean-field approach (the coherent switching with decay of mixing method), two surface-hopping methods [the fewest switches with time uncertainty (FSTU) and FSTU with stochastic decay (FSTU/SD) methods], and two surface-hopping methods with zero-point energy (ZPE) maintenance [the FSTUSD+trajectory projection onto ZPE orbit (TRAPZ) and FSTUSD+minimal TRAPZ (mTRAPZ) methods]. We found a qualitative difference between final NH(2) internal energy distributions obtained for n(2)=0 and n(2)>1, as observed in experiments. Distributions obtained for n(2)=1 present an intermediate behavior between distributions obtained for smaller and larger n(2) values. The dynamics is found to be highly electronically nonadiabatic with all these methods. NH(2) internal energy distributions may have a negative energy tail when the ZPE is not maintained throughout the dynamics. The original TRAPZ method was designed to maintain ZPE in classical trajectories, but we find that it leads to unphysically high internal vibrational energies. The mTRAPZ method, which is new in this work and provides a general method for maintaining ZPE in either single-surface or multisurface trajectories, does not lead to unphysical results and is much less time consuming. The effect of maintaining ZPE in mixed quantum/classical dynamics is discussed in terms of agreement with experimental findings. The dynamics for n(2)=0 and n(2)=6 are also analyzed to reveal details not available from experiment, in particular, the time required for quenching of electronic excitation and the adiabatic energy gap and geometry at the time of quenching.

  5. Zeno Paradox for Bohmian Trajectories: The Unfolding of the Metatron

    CERN Document Server

    de Gosson, Maurice

    2010-01-01

    We study an analogue of the quantum Zeno paradox for the Bohm trajectory of a sharply located particle (or a system of particles). We show that a continuously observed Bohm trajectory is the classical trajectory predicted by Hamiltonian mechanics.

  6. Classical trajectory Monte Carlo model calculations for the antiproton-induced ionization of atomic hydrogen at low impact energy

    CERN Document Server

    Sarkadi, L

    2015-01-01

    The three-body dynamics of the ionization of the atomic hydrogen by 30 keV antiproton impact has been investigated by calculation of fully differential cross sections (FDCS) using the classical trajectory Monte Carlo (CTMC) method. The results of the calculations are compared with the predictions of quantum mechanical descriptions: The semi-classical time-dependent close-coupling theory, the fully quantal, time-independent close-coupling theory, and the continuum-distorted-wave-eikonal-initial-state model. In the analysis particular emphasis was put on the role of the nucleus-nucleus (NN) interaction played in the ionization process. For low-energy electron ejection CTMC predicts a large NN interaction effect on FDCS, in agreement with the quantum mechanical descriptions. By examining individual particle trajectories it was found that the relative motion between the electron and the nuclei is coupled very weakly with that between the nuclei, consequently the two motions can be treated independently. A simple ...

  7. SU-E-T-489: Quantum versus Classical Trajectory Monte Carlo Simulations of Low Energy Electron Transport.

    Science.gov (United States)

    Thomson, R; Kawrakow, I

    2012-06-01

    Widely-used classical trajectory Monte Carlo simulations of low energy electron transport neglect the quantum nature of electrons; however, at sub-1 keV energies quantum effects have the potential to become significant. This work compares quantum and classical simulations within a simplified model of electron transport in water. Electron transport is modeled in water droplets using quantum mechanical (QM) and classical trajectory Monte Carlo (MC) methods. Water droplets are modeled as collections of point scatterers representing water molecules from which electrons may be isotropically scattered. The role of inelastic scattering is investigated by introducing absorption. QM calculations involve numerically solving a system of coupled equations for the electron wavefield incident on each scatterer. A minimum distance between scatterers is introduced to approximate structured water. The average QM water droplet incoherent cross section is compared with the MC cross section; a relative error (RE) on the MC results is computed. RE varies with electron energy, average and minimum distances between scatterers, and scattering amplitude. The mean free path is generally the relevant length scale for estimating RE. The introduction of a minimum distance between scatterers increases RE substantially (factors of 5 to 10), suggesting that the structure of water must be modeled for accurate simulations. Inelastic scattering does not improve agreement between QM and MC simulations: for the same magnitude of elastic scattering, the introduction of inelastic scattering increases RE. Droplet cross sections are sensitive to droplet size and shape; considerable variations in RE are observed with changing droplet size and shape. At sub-1 keV energies, quantum effects may become non-negligible for electron transport in condensed media. Electron transport is strongly affected by the structure of the medium. Inelastic scatter does not improve agreement between QM and MC simulations of low

  8. Classical trajectory Monte Carlo model calculations for ionization of the uracil molecule by impact of heavy ions

    Science.gov (United States)

    Sarkadi, L.

    2016-09-01

    The ionization of the uracil molecule induced by heavy-ion impact has been investigated using the classical trajectory Monte Carlo (CTMC) method. Assuming the validity of the independent-particle model approximation, the collision problem is solved by considering the three-body dynamics of the projectile, an active electron and the molecule core. The interaction of the molecule core with the other two particles is described by a multi-center potential built from screened atomic potentials. The cross section differential with respect to the energy and angle of the electrons ejected in the ionization process has been calculated for an impact of 3.5 MeV u-1 {{{C}}}6+ ions. Total electron emission cross sections (TCS) are presented for {{{C}}}q+ (q=0-6) and {{{O}}}6+ projectiles as a function of the impact energy in the range from 10 keV u-1 to 10 MeV u-1. The dependence of the TCS on the charge state of the projectile has been investigated for 2.5 MeV u-1 {{{O}}}q+ (q=4-8) and {{{F}}}q+ (q=5-9) ions. The results of the calculations are compared with available experimental data and the predictions of other theoretical models: the first Born approximation with correct boundary conditions (CB1), the continuum-distorted-wave-eikonal-initial-state approach (CDW-EIS), and the combined classical-trajectory Monte Carlo-classical over-the-barrier model (CTMC-COB).

  9. LETTER TO THE EDITOR: Sub-Poissonian photon statistics of higher harmonics: quantum predictions via classical trajectories

    Science.gov (United States)

    Bajer, Jirí; Miranowicz, Adam

    2000-06-01

    Second-harmonic generation in the no-energy-transfer regime can be a source of quasi-stationary sub-Poissonian light as was recently shown by Bajer et al (Bajer J, Haderka O and Perina J 1999 J. Opt. B: Quantum Semiclass. Opt. 1 529). We generalize their results for higher-harmonic generation by applying the numerical method of Hamiltonian diagonalization and the analytical semiclassical description of classical trajectories. The quasi-stationary behaviour of the sub-Poissonian photocount noise in the no-energy-transfer regime is explained. An approximate formula for the Fano factor is derived for arbitrary harmonics. It is predicted that the deepest quasi-stationary reduction of photocount noise in the no-energy-transfer regime is achieved in the third-harmonic generation.

  10. Semiclassical wave functions in billiards built on classical trajectories. Energy quantization, scars and periodic orbits

    CERN Document Server

    Giller, Stefan

    2011-01-01

    A way of construction of semiclassical wave function (SWF) based on the Maslov - Fedoriuk approach is proposed which appears to be appropriate also for systems with chaotic classical limits. Some classical constructions called skeletons are considered. The skeletons are generalizations of Arnolds' tori able to gather chaotic dynamics. SWF's are continued by caustic singularities in the configuration space rather then in the phase space using complex time method. The skeleton formulation provides us with a new algorithm for the semiclassical approximation method which is applied to construct SWF's as well as to calculate energy spectra for the circular and rectangular billiards as well as to construct the simplest SWF's and the respective spectrum for the Bunimovich stadium. The scar phenomena are considered and a possibility of their description by the skeleton method is discussed. PACS number(s): 03.65.-w, 03.65.Sq, 02.30.Jr, 02.30.Lt, 02.30.Mv Key Words: Schr\\"odinger equation, semiclassical expansion, Lagr...

  11. Symmetrical windowing for quantum states in quasi-classical trajectory simulations: Application to electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Cotton, Stephen J.; Igumenshchev, Kirill; Miller, William H., E-mail: millerwh@berkeley.edu [Department of Chemistry and Kenneth S. Pitzer Center for Theoretical Chemistry, University of California, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-08-28

    It has recently been shown [S. J. Cotton and W. H. Miller, J. Chem. Phys. 139, 234112 (2013)] that a symmetrical windowing quasi-classical (SQC) approach [S. J. Cotton and W. H. Miller, J. Phys. Chem. A 117, 7190 (2013)] applied to the Meyer-Miller model [H.-D. Meyer and W. H. Miller, J. Chem. Phys. 70, 3214 (1979)] for the electronic degrees of freedom in electronically non-adiabatic dynamics is capable of quantitatively reproducing quantum mechanical results for a variety of test applications, including cases where “quantum” coherence effects are significant. Here we apply this same SQC methodology, within a flux-side correlation function framework, to calculate thermal rate constants corresponding to several proposed models of electron transfer processes [P. Huo, T. F. Miller III, and D. F. Coker, J. Chem. Phys. 139, 151103 (2013); A. R. Menzeleev, N. Ananth, and T. F. Miller III, J. Chem. Phys. 135, 074106 (2011)]. Good quantitative agreement with Marcus Theory is obtained over several orders of magnitude variation in non-adiabatic coupling. Moreover, the “inverted regime” in thermal rate constants (with increasing bias) known from Marcus Theory is also reproduced with good accuracy by this very simple classical approach. The SQC treatment is also applied to a recent model of photoinduced proton coupled electron transfer [C. Venkataraman, A. V. Soudackov, and S. Hammes-Schiffer, J. Chem. Phys. 131, 154502 (2009)] and population decay of the photoexcited donor state is found to be in reasonable agreement with results calculated via reduced density matrix theory.

  12. Total cross sections for ionizing processes induced by proton impact on molecules of biological interest: A classical trajectory Monte Carlo approach

    Energy Technology Data Exchange (ETDEWEB)

    Lekadir, H.; Abbas, I.; Champion, C. [Universite Paul Verlaine Metz, Laboratoire de Physique Moleculaire et des Collisions, Institut J. Barriol FR CNRS 2843, 1 Bd Arago, 57078 Metz Cedex3 (France); Hanssen, J. [Universite Paul Verlaine Metz, Laboratoire de Physique Moleculaire et des Collisions, Institut J. Barriol FR CNRS 2843, 1 Bd Arago, 57078 Metz Cedex3 (France)], E-mail: jocelyn@univ-metz.fr

    2009-03-15

    In the current work, we present a study of ionizing interactions between protons and molecular targets of biological interest like water vapour and DNA bases. Total cross sections for single and multiple ionizing processes are calculated in the independent electron model and compared to existing theoretical and experimental results for impact energies ranging from 10 keV/amu to 10 MeV/amu. The theoretical approach combines some characteristics of the classical trajectory Monte Carlo method with the classical over-barrier framework. In this 'mixed' approach, all the particles are described in a classical way by assuming that the target electrons are involved in the collision only when their binding energy is greater than the maximum of the potential energy of the system projectile-target. We test our theoretical approach on the water molecule and the obtained results are compared to a large set of data and a reasonable agreement is generally observed specially for impact energies greater than 100 keV, except for the double ionization process for which large discrepancies are reported. Considering the DNA bases, the obtained results are given without any comparison since the literature is till now very poor in terms of cross section measurements.

  13. Classical trajectories in polar-asymmetric laser fields: Synchronous THz and XUV emission

    Science.gov (United States)

    Gragossian, Aram; Seletskiy, Denis V.; Sheik-Bahae, Mansoor

    2016-10-01

    The interaction of intense near- and mid-infrared laser pulses with rare gases has produced bursts of radiation with spectral content extending into the extreme ultraviolet and soft x-ray region of electromagnetic spectrum. On the other end of the spectrum, laser-driven gas plasmas has been shown to produce coherent sub-harmonic optical waveforms, covering from terahertz (THz) to mid- and near-infrared frequency spectral band. Both processes can be enhanced via a combination of a driving field and its second harmonic. Despite this striking similarity, only limited experimental and theoretical attempts have been made to address these two regimes simultaneously. Here we present systematic experiments and a unifying picture of these processes, based on our extension of the semi-classical three-step model. Further understanding of the generation and coherent control of time-synchronized transients with photon energies from meV to 1 keV can lead to numerous technological advances and to an intriguing possibilities of ultra-broadband investigations into complex condensed matter systems.

  14. Young adults' trajectories of Ecstasy use: a population based study.

    Science.gov (United States)

    Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

    2013-11-01

    Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns.

  15. Simulation Study on Fuzzy Control of Rotary Steering Drilling Trajectory

    Directory of Open Access Journals (Sweden)

    Xue Qi-Long

    2012-07-01

    Full Text Available The purpose of this study is to establish a control method to make borehole trajectory smoother. Considering that the complexity of rotary steerable drilling trajectory control and uncertainty of underground work, analysis of the deficiencies for the traditional trajectory control and the rotary steerable drilling trajectory deviation vector control theory, introduced the concept of "trend Angle", combined with the deviation vector as joint control variables, using fuzzy control algorithm that established of rotary steerable drilling trajectory fuzzy control model. Designed the fuzzy controller using Matlab/Simulink toolbox and dynamic simulation analysis for the fuzzy control systems, simulation results show that the designed fuzzy controller can effectively track the well path design, has a strong adaptability and control results is better than traditional PID control method.

  16. Quasi-classical trajectory approach to the stereo-dynamics of the reaction F+HO→HF+O

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Quasi-classical trajectory (QCT) calculations are employed for the reaction F + HO(0,0)→HF + O based on the adiabatic potential energy surface (PES) of the ground 3A″triplet state. The average rotational alignment factor as a function of collision energy and the four polarization dependent generalized differential cross sections have been calculated in the center-of-mass (CM) frame, separately. The distribution P(θr) of the angle between k and j′, the distribution P(θr) of dihedral angle denoting k-k′-j′ correlation, and the angular distribution P(θr, Φr) of product rotational vectors in the form of polar plots are calculated as well. The effect of Heavy-Light-Heavy (HLH) mass combination and atom F’s relatively strong absorbability to charges on the alignment and the orientation of product molecule HF rotational angular momentum vectors j′ is revealed.

  17. Ab initio direct classical trajectory investigation on the SN2 reaction of F- with NH2F: nonstatistical central barrier recrossing dynamics.

    Science.gov (United States)

    Yu, Feng

    2012-02-05

    The bimolecular nucleophilic substitution (S(N)2) reaction of F(a)(-) with NH(2)F(b) has been investigated with the ab initio direct classical trajectory method. According to our trajectory calculations, a dynamic behavior of nonstatistical central barrier recrossing is revealed. Among the 64 trajectories calculated in this work, 45 trajectories follow the dynamic reaction pathways as assumed by statistical theory and other 19 trajectories with central barrier recrossings are nonstatistical. For the nonstatistical trajectories, the central barrier recrossings may originate from the inefficient kinetic energy transfer from the intramolecular modes of the NH(2)F(a) moiety in the dynamic F(b)(-)…H-NH-F(a) complex to the intermolecular modes of the dynamic F(b)(-)…H-NH-F(a) complex on the exit-channel potential energy surface. With respect to the dynamic behavior of the nonstatistical central barrier recrossing, the statistical theories such as the Rice-Ramsperger-Kassel-Marcus and transition state theories without further corrections cannot be used to model the reaction kinetics for this S(N)2 reaction.

  18. Galileo's Trajectory with Mild Resistance

    Science.gov (United States)

    Groetsch, C. W.

    2012-01-01

    An aspect of Galileo's classical trajectory that persists in a simple resistance model is noted. The resistive model provides a case study for the classroom analysis of limiting behaviour of an implicitly defined function. (Contains 1 note.)

  19. Extension of high-order harmonic cutoff frequency by synthesizing the waveform of a laser field via the optimization of classical electron trajectory in the laser field

    Institute of Scientific and Technical Information of China (English)

    Zhao Di; Li Fu-Li

    2013-01-01

    We theoretically investigate high-order harmonic generation by employing strong-field approximation (SFA) and present a new approach to the extension of the high-order harmonic cutoff frequency via an exploration of the dependence of high-order harmonic generation on the waveform of laser fields.The dependence is investigated via detailed analysis of the classical trajectories of the ionized electron moving in the continuum in the velocity-position plane.The classical trajectory consists of three sections (Acceleration Away,Deceleration Away,and Acceleration Back),and their relationship with the electron recollision energy is investigated.The analysis of classical trajectories indicates that,besides the final (Acceleration Back) section,the electron recollision energy also relies on the previous two sections.We simultaneously optimize the waveform in all three sections to increase the electron recollision energy,and an extension of the cutoff frequency up to Ip + 20.26Up is presented with a theoretically synthesized waveform of the laser field.

  20. Time-dependent wave packet quantum and quasi-classical trajectory study of He + H₂⁺, D₂⁺ → HeH⁺ + H, HeD⁺ + D reaction on an accurate FCI potential energy surface.

    Science.gov (United States)

    Zhao, Juan; Luo, Yi

    2012-03-15

    The quantum scattering dynamics and quasi-classical trajectory (QCT) calculations have been carried out for the title reaction on an accurate potential energy surface (PES) computed using the full configuration interaction (FCI). On the basis of the PES, the integral cross-sections of He + H₂⁺ (v = 0-3, j = 1) → HeH⁺ + H reaction have been calculated, and the results are generally agreed with the experimental cross-sections obtained by Tang et al. [J. Chem. Phys. 2005, 122, 164301] after taking into account the experimental uncertainties, which proves the reliability of implementing dynamics calculations on the FCI PES. The reaction probability of He + D₂⁺ (v = 0-2, j = 0) → HeD⁺ + D reactions for total angular momentum J = 0 and the integral cross-section (ICS) have been calculated. The significant quantum effect has been explored by the comparison between the QCT reaction probabilities (or ICS) and the quantum mechanical (QM) reaction probabilities (or ICS), which may be attributed to the deep well in the PES of this light atoms system. Furthermore, the role of Coriolis coupling (CC) effects has also been found not important by the comparison between the CC calculation and the centrifugal sudden (CS) approximation calculation, except that the CC total cross-sections for the v = 1 and 2 states show the collision energy-dependent behaviors in the low-energy area, which are different from those based on the CS calculation.

  1. Trajectory study of dissociation reactions. The single-ensemble method. II

    Science.gov (United States)

    Kutz, H. Douglas; Burns, George

    1981-04-01

    The single uniform ensemble method was previously employed in 3D classical trajectory calculations [H. D. Kutz and G. Burns, J. Chem. Phys. 72, 3652 (1980)]. Presently it is applied to the Br2+Ar system to study nonequilbrium effects in diatom dissociation over a wide temperature range. It was found that, for a given large set of trajectories, observables, such as reaction cross sections or rate constants, are indepedent within four significant figures of the initial distribution function. This indicates a high degree of reliability of the single uniform ensemble method, once the choice of a set of trajectories is made. In order to study dissociation from the low lying energy states, the uniform velocity selection method in trajectory calculations was used. It was found that dissociation from these states contributes but little to the overall dissociation reaction. The latter finding is consistent with the attractive nature of the potential energy surface used, and constitutes an argument against those current theories of diatom dissociation reaction which explains experimental data by postulating a high probability of dissociation from low lying energy states of diatoms. It was found that the contribution from the low lying states to dissociation can be estimated with good accuracy using information theory expressions. Temperature dependence of nonequilibrium effects was investigated between 1 500 and 6 000 °K. In this range the nonequilibrium correction factor varies between 0.2 and 0.5. Angular momentum dependence of such observables as reaction rate constant and reaction cross section was investigated.

  2. Common trajectories of physical functioning in the doetinchem cohort study

    NARCIS (Netherlands)

    Rooth, Vera; Van Oostrom, Sandra H.; Deeg, Dorly J H; Monique Verschuren, W. M.; Picavet, H. Susan J

    2016-01-01

    Purpose: To describe common trajectories of physical functioning and their determinants among an adult cohort, followed over a period of 15 years. Methods: The study sample consisted of 4,123 participants (initial ages 26-70 years) from the Doetinchem Cohort Study, who participated in three or four

  3. Study on Control Algorithm for Continuous Segments Trajectory Interpolation

    Institute of Scientific and Technical Information of China (English)

    SHI Chuan; YE Peiqing; LV Qiang

    2006-01-01

    In CNC machining, the complexity of the part contour causes a series of problems including the repeated start-stop of the motor, low machining efficiency, and poor machining quality. To relieve those problems, a new interpolation algorithm was put forward to realize the interpolation control of continuous sections trajectory. The relevant error analysis of the algorithm was also studied. The feasibility of the algorithm was proved by machining experiment using a laser machine to carve the interpolation trajectory in the CNC system GT100. This algorithm effectively improved the machining efficiency and the contour quality.

  4. Trajectory data analyses for pedestrian space-time activity study.

    Science.gov (United States)

    Qi, Feng; Du, Fei

    2013-01-01

    It is well recognized that human movement in the spatial and temporal dimensions has direct influence on disease transmission(1-3). An infectious disease typically spreads via contact between infected and susceptible individuals in their overlapped activity spaces. Therefore, daily mobility-activity information can be used as an indicator to measure exposures to risk factors of infection. However, a major difficulty and thus the reason for paucity of studies of infectious disease transmission at the micro scale arise from the lack of detailed individual mobility data. Previously in transportation and tourism research detailed space-time activity data often relied on the time-space diary technique, which requires subjects to actively record their activities in time and space. This is highly demanding for the participants and collaboration from the participants greatly affects the quality of data(4). Modern technologies such as GPS and mobile communications have made possible the automatic collection of trajectory data. The data collected, however, is not ideal for modeling human space-time activities, limited by the accuracies of existing devices. There is also no readily available tool for efficient processing of the data for human behavior study. We present here a suite of methods and an integrated ArcGIS desktop-based visual interface for the pre-processing and spatiotemporal analyses of trajectory data. We provide examples of how such processing may be used to model human space-time activities, especially with error-rich pedestrian trajectory data, that could be useful in public health studies such as infectious disease transmission modeling. The procedure presented includes pre-processing, trajectory segmentation, activity space characterization, density estimation and visualization, and a few other exploratory analysis methods. Pre-processing is the cleaning of noisy raw trajectory data. We introduce an interactive visual pre-processing interface as well as an

  5. Trajectories of picky eating during childhood : A general population study

    NARCIS (Netherlands)

    Cano, Sebastian Cardona; Tiemeier, Henning; Van Hoeken, Daphne; Tharner, Anne; Jaddoe, Vincent W. V.; Hofman, Albert; Verhulst, Frank C.; Hoek, Hans W.

    2015-01-01

    ObjectiveThis cohort study describes the prevalence of picky eating and examines prognostic factors for picky eating trajectories during childhood. Methods4,018 participants of a population-based cohort with measurements from pregnancy onwards were included. Picky eating was assessed by maternal rep

  6. Acoustical study of classical Peking Opera singing.

    Science.gov (United States)

    Sundberg, Johan; Gu, Lide; Huang, Qiang; Huang, Ping

    2012-03-01

    Acoustic characteristics of classical opera singing differ considerably between the Western and the Chinese cultures. Singers in the classical Peking opera tradition specialize on one out of a limited number of standard roles. Audio and electroglottograph signals were recorded for four performers of the Old Man role and three performers of the Colorful Face role. Recordings were made of the singers' speech and when they sang recitatives and songs from their roles. Sound pressure level, fundamental frequency, and spectrum characteristics were analyzed. Histograms showing the distribution of fundamental frequency showed marked peaks for the songs, suggesting a scale tone structure. Some of the intervals between these peaks were similar to those used in Western music. Vibrato rate was about 3.5Hz, that is, considerably slower than in Western classical singing. Spectra of vibrato-free tones contained unbroken series of harmonic partials sometimes reaching up to 17 000Hz. Long-term-average spectrum (LTAS) curves showed no trace of a singer's formant cluster. However, the Colorful Face role singers' LTAS showed a marked peak near 3300Hz, somewhat similar to that found in Western pop music singers. The mean LTAS spectrum slope between 700 and 6000Hz decreased by about 0.2dB/octave per dB of equivalent sound level.

  7. Chemical reaction dynamics of Rydberg atoms with neutral molecules: a comparison of molecular-beam and classical trajectory results for the H(n)+D2-->HD+D(n') reaction.

    Science.gov (United States)

    Song, Hui; Dai, Dongxu; Wu, Guorong; Wang, Chia Chen; Harich, Steven A; Hayes, Michael Y; Wang, Xiuyan; Gerlich, Dieter; Yang, Xueming; Skodje, Rex T

    2005-08-15

    Recent molecular-beam experiments have probed the dynamics of the Rydberg-atom reaction, H(n)+D2-->HD+D(n) at low collision energies. It was discovered that the rotationally resolved product distribution was remarkably similar to a much more limited data set obtained at a single scattering angle for the ion-molecule reaction H++D2-->D++HD. The equivalence of these two problems would be consistent with the Fermi-independent-collider model (electron acting as a spectator) and would provide an important new avenue for the study of ion-molecule reactions. In this work, we employ a classical trajectory calculation on the ion-molecule reaction to facilitate a more extensive comparison between the two systems. The trajectory simulations tend to confirm the equivalence of the ion+molecule dynamics to that for the Rydberg-atom+molecule system. The theory reproduces the close relationship of the two experimental observations made previously. However, some differences between the Rydberg-atom experiments and the trajectory simulations are seen when comparisons are made to a broader data set. In particular, the angular distribution of the differential cross section exhibits more asymmetry in the experiment than in the theory. The potential breakdown of the classical model is discussed. The role of the "spectator" Rydberg electron is addressed and several crucial issues for future theoretical work are brought out.

  8. Comparison study of sub-trajectory clustering in data mining

    Science.gov (United States)

    Yang, Guodong; Huang, Zhitao; Wang, Xiang

    2017-06-01

    Trajectory clustering is an important method to achieve moving object data mining, multi-sensor information fusion and trajectory knowledge discovery. Sub-trajectory clustering is an important method to extract useful information from a large number of trajectory data in trajectory analysis. In this paper, comparative experiments are made on the time consumption, similarity measure and clustering performance based on the existing sub-trajectory clustering methods. Based on the comparisons, the advantages and disadvantages of different methods are presented and an improved method is proposed for dealing with trajectories with low positioning accuracy and correlating tracklets from asynchronous sensors. Besides, a general framework of trajectory data mining is discussed.

  9. Single electron ionization and electron capture cross sections for (C{sup 6+}, H{sub 2}O) interaction within the Classical Trajectory Monte Carlo (CTMC) approach

    Energy Technology Data Exchange (ETDEWEB)

    Tran, H.N., E-mail: tranngochoang@tdt.edu.vn [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Dao, D.D. [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Incerti, S. [Division of Nuclear Physics, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); Faculty of Applied Sciences, Ton Duc Thang University, Tan Phong Ward, District 7, Ho Chi Minh City (Viet Nam); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); Bernal, M.A. [Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, SP (Brazil); Karamitros, M. [CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Université de Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); Nhan Hao, T.V. [Center of Research and Development, Duy Tan University, K7/25 Quang Trung, Danang (Viet Nam); Center for Theoretical and Computational Physics, College of Education, Hue University, 34 Le Loi Street, Hue City (Viet Nam); Dang, T.M. [VNUHCM-University of Science (Viet Nam); Francis, Z. [Saint Joseph University, Beyrouth (Lebanon)

    2016-01-01

    In this work, we present a derivation of cross sections for single ionization and electron capture processes within the Classical Trajectory Monte Carlo (CTMC) approach. Specifically, we have used a potential stemming from an ab initio calculation in Green et al.’s framework to describe the dynamics of the water molecule system. Proposing a modified version of the Classical Over-Barrier (COB) potential, we have found that a cut-off of roughly 28 a.u. on the initial distance of the projectile produced a reasonable accuracy. A global agreement has been obtained in our calculations compared to experimental and other theoretical results for C{sup 6+} ion energies ranging from 10 keV/u to 10 MeV/u.

  10. Adiponectin trajectories before type 2 diabetes diagnosis: Whitehall II study.

    Science.gov (United States)

    Tabák, Adam G; Carstensen, Maren; Witte, Daniel R; Brunner, Eric J; Shipley, Martin J; Jokela, Markus; Roden, Michael; Kivimäki, Mika; Herder, Christian

    2012-12-01

    The role of adiponectin in the natural history of diabetes is not well characterized. We set out to characterize prediagnosis trajectories of adiponectin in individuals who develop type 2 diabetes. In a case-cohort study (335 incident diabetes case and 2,474 noncase subjects) nested in the Whitehall II study, serum adiponectin was measured up to three times per participant (1991-1993, 1997-1999, and 2003-2004). Multilevel models adjusted for age and ethnicity were fitted to assess 13-year trajectories of log-transformed adiponectin preceding diabetes diagnosis or a randomly selected time point during follow-up (year(0)) based on 755/5,095 (case/noncase) person-examinations. Adiponectin levels were lower in diabetes case than in noncase subjects (median 7,141 [interquartile range 5,187-10,304] vs. 8,818 [6,535-12,369] ng/mL at baseline, P obesity, whereas the sex-specific slope differences were independent of obesity. Lower adiponectin levels were observed already a decade before the diagnosis of diabetes. The marked sex difference in trajectories suggests that sex-specific mechanisms affect the association between adiponectin levels and diabetes development.

  11. Study of a classical strobe composition

    NARCIS (Netherlands)

    Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

    2013-01-01

    Many strobe compositions were discovered in the past but only a few have been studied and none of them were fully understood. This article aimed at introducing the ternary composition of ammonium perchlorate as oxidizer, magnalium as fuel, and barium sulfate as metal salt. Parameters that influence

  12. Guidance and dispersion studies of National Launch System ascent trajectories

    Science.gov (United States)

    Hanson, John M.; Shrader, M. W.; Chang, Hopen; Freeman, Scott E.

    1992-01-01

    The National Launch System (NLS) is a joint concept, between DoD and NASA, for building a family of new launch vehicles. Two of the many choices to be made are the trajectory shaping methods and the onboard guidance scheme. This paper presents results from some ongoing studies to address these issues. First, potential gains from new guidance concepts are listed. Next the paper gives a list of possible discriminators between different guidance schemes, lists a number of potential guidance schemes, and explains two in some detail. A reference scheme is tested to determine its performance versus the discriminators. Finally, results from some special studies using the reference guidance scheme are given, including the effects of closed-loop guidance initiation time, time of enforcement of sideslip, vehicle roll for engine out, time and location of an engine out, use of load relief control, and use of day of launch wind biasing.

  13. APPROACHES TO STUDY EDUCATIONAL AND OCCUPATIONAL TRAJECTORIES AND OUTCOMES

    Directory of Open Access Journals (Sweden)

    Tovar-García, Edgar Demetrio

    2012-04-01

    Full Text Available This article analyzes the main approaches to study educational and occupational outcomes and trajectories. Young people have to decide when and what to study, later on, where to work. Their life levels will depend on those decisions, but the different ways that in both areas they are able to take and their outcomes in education and in the labor market depend on various factors. Among explications it is possible to identify six large approaches: human capital from economics, cultural and social capital from sociology, the socioeconomic status or familiar background approach and the educational and psychological approaches. These approaches are not contrary necessarily, they can be complementary, and their explanatory power depends on place and time, however, the literature does not have an effort to present together their contributions, methodologies and empirical results. This work seeks to remedy that situation and to point out some methodological and empirical weakness.

  14. Demand Characteristics in Classical Verbal Conditioning and Attitude Conditioning Studies.

    Science.gov (United States)

    McGinley, Hugh

    This paper is a draft for the American Psychological Association Symposium on the conditioning of verbal behavior and attitudes. The author presents the results of several studies he conducted in the classical conditioning of meaning and attitude. These studies attempt to control the measurement effects created by extraneous variables operating on…

  15. Lymphangiogenesis in Classical Hodgkin Lymphoma - Preliminary Study with Clinicopathological Correlations

    Science.gov (United States)

    Benharroch, Daniel; Prinsloo, Isebrand; Gopas, Jacob; Lazarev, Irena

    2016-01-01

    A role for lymphangiogenesis in metastatic breast and prostate cancers has been suggested recently. The relevance of lymphangiogenesis in cancer as a rule, and more specifically in classical Hodgkin lymphoma, is poorly understood in comparison with that of angiogenesis. In a preliminary (pilot) study we have investigated the role of lymphatic vessels growth in 19 cases of classical Hodgkin lymphoma stained with the D2-40 (podoplanin) antibody. In each case, three lymphatic vessels hot spots were scrutinized twice. Of the 57 hot spots thus identified, we chose 15 at random for photography, microvessel counting and image analysis. We determined the mean perimeter, surface area, major axis length and complexity factor for each hot spot and correlated them with clinical and biological features of classical Hodgkin lymphoma. No correlations were found with clinical features. No associations were noted with the standard immuno-markers of classical Hodgkin lymphoma. However, significant inverse correlations were shown with pRb, BAX and IκB-α expression. The mean lymphatic major axis length was inversely correlated with the complexity factor. Last, we carried out an additional clinicopathological correlation of the expression of pRb, BAX and IκB-α in a cohort of classical Hodgkin lymphoma patients previously published. PMID:27877228

  16. Study of Trajectory of Spin-Stabilised Artillery Projectiles

    Directory of Open Access Journals (Sweden)

    M. Krishnamurthy

    1991-10-01

    Full Text Available Equations of motion for conventional spin-stabilised artillery projectile have been derived using a pseudo-stability axes system in addition to body-fixed and space-fixed axes systems. The aerodynamic forces and moments have been represented by their respective coefficients and the effects of Mach number and Reynolds number have been suitably accounted. The magnus terms which are significant at high rates of spin are estimated using a simple model. The set of equations have been partly linearised and solved numerically for a typical projectile using NAG system routines. Various trajectory parameters are computed and compared with the range-table data for the projectile. A parametric study had been carried out varying the aerodynamic coefficients to understand the sensitivity of the results obtained.

  17. Quantum trajectories

    CERN Document Server

    Chattaraj, Pratim Kumar

    2010-01-01

    The application of quantum mechanics to many-particle systems has been an active area of research in recent years as researchers have looked for ways to tackle difficult problems in this area. The quantum trajectory method provides an efficient computational technique for solving both stationary and time-evolving states, encompassing a large area of quantum mechanics. Quantum Trajectories brings the expertise of an international panel of experts who focus on the epistemological significance of quantum mechanics through the quantum theory of motion.Emphasizing a classical interpretation of quan

  18. Pair-correlated product speed and angular distributions for the OH+CH4/CD4 reactions: Further remarks on their classical trajectory calculations in a quantum spirit

    CERN Document Server

    Bonnet, L; Corchado, J

    2015-01-01

    Ten years ago, Liu and co-workers measured pair-correlated product speed and angular distributions for the OH+CH4/CD4 reactions at the collision energy of ~ 10 kcal/mol [B. Zhang, W. Shiu, J. J. Lin and K. Liu, J. Chem. Phys 122, 131102 (2005); B. Zhang, W. Shiu and K. Liu, J. Phys. Chem. A 2005, 109, 8989]. Recently, two of us could semi-quantitatively reproduce these measurements by performing full-dimensional classical trajectory calculations in a quantum spirit on an ab-initio potential energy surface of their own [J. Espinosa-Garcia and J. C. Corchado, Theor Chem Acc, 2015, 134, 6 ; J. Phys. Chem. B, Article ASAP, DOI: 10.1021/acs.jpcb.5b04290]. The goal of the present work is to show that these calculations can be significantly improved by adding a few more constraints to better comply with the experimental conditions. Overall, the level of agreement between theory and experiment is remarkable considering the large dimensionality of the processes under scrutiny.

  19. A Semi-Classical Model to Study Nuclear Fragmentation

    Science.gov (United States)

    Navarro, Martha; Chernomoretz, Ariel; Dorso, Claudio; Lopez, Jorge

    1999-10-01

    A semi-classical model based on the use of molecular dynamics has been developed for the study of heavy-ion reactions at intermediate energies. The model reproduces nucleon-nucleon cross sections through the use of a two-body potential. The study covers several characteristics of heavy-ion collisions, such as formation of necks, and formation of intermediate residue. Preliminary results on the use of the model to study the caloric curve of nuclear matter and the temperature evolution of the system are also discussed.

  20. Aging Trajectories in Different Body Systems Share Common Environmental Etiology : The Healthy Aging Twin Study (HATS)

    NARCIS (Netherlands)

    Moayyeri, Alireza; Hart, Deborah J.; Snieder, Harold; Hammond, Christopher J.; Spector, Timothy D.; Steves, Claire J.

    Little is known about the extent to which aging trajectories of different body systems share common sources of variance. We here present a large twin study investigating the trajectories of change in five systems: cardiovascular, respiratory, skeletal, morphometric, and metabolic. Longitudinal

  1. A Study of Classics-Reading Curriculum, Classics-Reading Promotion, and Classics-Reading Effect Modeling Exploration in Elementary Schools

    Directory of Open Access Journals (Sweden)

    Chuen-An Tang

    2014-01-01

    Full Text Available The purposes of this study are to test reliabilities and validities of classics-reading curriculum (CRC scale, classics-reading promotion (CRP scale, and classics-reading effect (CRE scale and to examine the relationships between CRC, CRP, and CRE in elementary schools through applying CORPS framework. The pilot sample and formal sample contain 141 and 500 participants from elementary school faculties and classics-reading volunteers in the north, central, south, and east regions of Taiwan. The findings indicate that Cronbach α coefficients of curriculum cognition (CC, curriculum teaching (CT, inside-school promotion (IP, outside-school promotion (EP, learning effect (LE, and class management effect (CME subscales are .88, .85, .93, .91, .91, .94, respectively, through exploratory factor analysis and they have good internal reliabilities and construct validities, respectively, through confirmatory factor analysis. Moreover, CC, CT, IP, and EP have positive influences on LE (standardized coefficients .34, .25, .14, and .22 and on CME (standardized coefficients .41, .14, .14, and .20, respectively. CC, CT, IP, and EP can explain 69% of LE and 61% of CME. The model is supported by the data. Lastly, this study proposes some suggestions regarding the classics-reading education for elementary schools.

  2. Direct dynamics trajectory study of the reaction of formaldehyde cation with D2: vibrational and zero-point energy effects on quasiclassical trajectories.

    Science.gov (United States)

    Liu, Jianbo; Song, Kihyung; Hase, William L; Anderson, Scott L

    2005-12-22

    Quasiclassical, direct dynamics trajectories have been used to study the reaction of formaldehyde cation with molecular hydrogen, simulating the conditions in an experimental study of H2CO+ vibrational effects on this reaction. Effects of five different H2CO+ modes were probed, and we also examined different approaches to treating zero-point energy in quasiclassical trajectories. The calculated absolute cross-sections are in excellent agreement with experiments, and the results provide insight into the reaction mechanism, product scattering behavior, and energy disposal, and how they vary with impact parameter and reactant state. The reaction is sharply orientation-dependent, even at high collision energies, and both trajectories and experiment find that H2CO+ vibration inhibits reaction. On the other hand, the trajectories do not reproduce the anomalously strong effect of nu2(+) (the CO stretch). The origin of the discrepancy and approaches for minimizing such problems in quasiclassical trajectories are discussed.

  3. Classical and quantum studies of the photodissociation of a HX (X=Cl,F) molecule adsorbed on ice.

    Science.gov (United States)

    Woittequand, S; Duflot, D; Monnerville, M; Pouilly, B; Toubin, C; Briquez, S; Meyer, H-D

    2007-10-28

    The photodissociation dynamics of a HX (X = Cl,F) molecule adsorbed on a hexagonal ice surface at T = 0 K is studied using time-dependent quantum wave packets and quasiclassical trajectories. The relevant potential energy surfaces are calculated using high-level ab initio methods. We present here two dimensional calculations for the dynamics of the hydrogen photofragment for both HCl and HF molecules. The purpose of this paper is to compare the photodissociation dynamics of the two molecules which are adsorbed on the ice surface with different equilibrium geometries. The total photodissociation cross section and the angular distribution are calculated. The comparison with classical trajectory calculations provides evidence for typical quantum effects and reveals rainbow structures.

  4. [Applications of reverse genetics in studying classical swine fever virus].

    Science.gov (United States)

    Liu, Dafei; Sun, Yuan; Qiu, Huaji

    2009-10-01

    Classical swine fever (CSF), caused by classical swine fever virus (CSFV), has been epidemic or endemic in many countries, and causes great economical losses to pig industry worldwide. Attenuated vaccines (such as C-strain) have played an important role in the control of CSF. Recently some new phenomena appear, such as atypical and persistent infections of CSF, immunization failure and so on. Meanwhile, eradication programs have been implemented in many countries, restricting the widespread applications of attenuated vaccines. Thus, currently the priority is to strengthen the research in pathogenesis and transmission mechanisms, as well as to develop marker vaccines. Recently, the applications of reverse genetics technology open up a new way for research of structure and function of CSFV proteins and development of novel vaccines against CSF. This review focuses on the progress of applications of reverse genetics in the functional analysis and marker vaccine development of CSFV, and also discusses the problems confronted now and prospective aspects in the study of CSFV.

  5. Trajectory study of supercollision relaxation in highly vibrationally excited pyrazine and CO2.

    Science.gov (United States)

    Li, Ziman; Sansom, Rebecca; Bonella, Sara; Coker, David F; Mullin, Amy S

    2005-09-01

    Classical trajectory calculations were performed to simulate state-resolved energy transfer experiments of highly vibrationally excited pyrazine (E(vib) = 37,900 cm(-1)) and CO(2), which were conducted using a high-resolution transient infrared absorption spectrometer. The goal here is to use classical trajectories to simulate the supercollision energy transfer pathway wherein large amounts of energy are transferred in single collisions in order to compare with experimental results. In the trajectory calculations, Newton's laws of motion are used for the molecular motion, isolated molecules are treated as collections of harmonic oscillators, and intermolecular potentials are formed by pairwise Lennard-Jones potentials. The calculations qualitatively reproduce the observed energy partitioning in the scattered CO(2) molecules and show that the relative partitioning between bath rotation and translation is dependent on the moment of inertia of the bath molecule. The simulations show that the low-frequency modes of the vibrationally excited pyrazine contribute most to the strong collisions. The majority of collisions lead to small DeltaE values and primarily involve single encounters between the energy donor and acceptor. The large DeltaE exchanges result from both single impulsive encounters and chattering collisions that involve multiple encounters.

  6. Marshaling Resources: A Classic Grounded Theory Study of Online Learners

    Directory of Open Access Journals (Sweden)

    Barbara Yalof

    2014-06-01

    Full Text Available Classic grounded theory (CGT was used to identify a main concern of online students in higher education. One of the main impediments to studying online is a sense of isolation and lack of access to support systems as students navigate through complex requirements of their online programs. Hypothetical probability statements illustrate the imbalance between heightened needs of virtual learners and perceived inadequate support provided by educational institutions. The core variable, marshaling resources, explains how peer supports sustain motivation toward successful program completion. Understanding the critical contribution virtual interpersonal networks make towards maximizing resources by group problem solving is a significant aspect of this theory. Keywords: Online learning, e-learning, personal learning networks, peer networks

  7. A Classical Trajectory Study of the Dissociation and Isomerization of C2H5

    Science.gov (United States)

    2013-01-01

    combustion properties as laminar flame speeds, induction times, and flammability, extinction , and ignition limits.1,2 Because of its importance in combustion...photoionized and subsequently detected by mass spectroscopy. Recently, Steinbauer et al.11 confirmed the existence of both a unimolecular and direct...q) determines the imaginary frequency at the saddle point. S′(q) was given more flexibility to set this frequency by making it a sixth order

  8. Congenitally Deaf Children's Care Trajectories in the Context of Universal Neonatal Hearing Screening: A Qualitative Study of the Parental Experiences

    Science.gov (United States)

    Hardonk, Stefan; Desnerck, Greetje; Loots, Gerrit; Van Hove, Geert; Van Kerschaver, Erwin; Sigurjonsdottir, Hanna Bjorg; Vanroelen, Christophe; Louckx, Fred

    2011-01-01

    The objective of this study is to examine the early care trajectories of congenitally deaf children from a parental perspective, starting with universal neonatal hearing screenings. The analysis using a three-dimensional care trajectory concept is aimed at developing a basic typology of postscreening care trajectories. Children with…

  9. Hybrid trajectory spaces

    NARCIS (Netherlands)

    Collins, P.J.

    2005-01-01

    In this paper, we present a general framework for describing and studying hybrid systems. We represent the trajectories of the system as functions on a hybrid time domain, and the system itself by its trajectory space, which is the set of all possible trajectories. The trajectory space is given a na

  10. New and classical applications of heat flow studies

    Science.gov (United States)

    Clauser, C.

    2005-12-01

    This special issue of Journal of Geophysics and Engineering is dedicated to a collection of papers which resulted from an international workshop held in Aachen, Germany, on 4-7 October 2004, called 'New and Classical Applications of Heat Flow Studies'. This was the third in a series of topical geothermal workshops arranged by the Geothermal Working Group of the German Geophysical Society (DGG) and was organized by the Institute of Applied Geophysics at RWTH Aachen University under the auspices of the International Heat Flow Commission of the International Association of Seismology and Physics (IASPEI). The meeting was attended by some 60 scientists from 14 countries and three continents. Financial assistance, granted by DGG and IASPEI, allowed us to provide partial support for a total of eight students, young scientists and eminent researchers from eastern Europe and overseas. The convenors of the meeting were Christoph Clauser (Aachen), Thomas Kohl (Zürich) and Makoto Taniguchi (Kyoto). The main local organizers were Volker Rath (scientific programme) and Ute Kreutz (accommodation and financial affairs). The topics addressed in more than 50 oral and poster presentations indicated that today intriguing new applications of heat flow studies have emerged, complementing the classical topics of heat flow mapping and the tectonic implications of heat flow. In classical applications, for instance, thermal signatures of water flow or downward diffusion of variations in the Earth's mean temperature are considered as noise which needs to be corrected prior to further use of the data. In contrast, in several new applications it is exactly the information contained in these signatures which has been extracted and interpreted. For instance, over the past two decades, work on the most prominent of these new applications has been devoted to inverting the variation of the Earth's past mean ground surface temperature (GST). As of today, GST provided by the geothermal method has

  11. Feasibility study of a single, elliptical heliocentric Earth-Mars trajectory

    Science.gov (United States)

    Blake, M.; Fulgham, K.; Westrup, S.

    1989-01-01

    The initial intent of this design project was to evaluate the existence and feasibility of a single elliptical heliocentric Earth/Mars trajectory. This trajectory was constrained to encounter Mars twice in its orbit, within a time interval of 15 to 180 Earth days between encounters. The single ellipse restriction was soon found to be prohibitive for reasons shown later. Therefore, the approach taken in the design of the round-trip mission to Mars was to construct single-leg trajectories which connected two planets on two prescribed dates. Three methods of trajectory design were developed. Method 1 is an eclectic approach and employs Gaussian Orbit Determination (Method 1A) and Lambert-Euler Preliminary Orbit Determination (Method 1B) in conjunction with each other. Method 2 is an additional version of Lambert's Solution to orbit determination, and both a coplanar and a noncoplanar solution were developed within Method 2. In each of these methods, the fundamental variables are two position vectors and the time between the position vectors. In all methods, the motion was considered Keplerian motion and the reference frame origin was located at the sun. Perturbative effects were not considered in Method 1. The feasibility study of round-trip Earth/Mars trajectories maintains generality by considering only heliocentric trajectory parameters and planetary approach conditions. The coordinates and velocity components of the planets, for the standard epoch J2000, were computed from an approximate set of osculating elements by the procedure outlined in an ephemeris of coordinates.

  12. A study into lowering beam trajectories in P01

    Energy Technology Data Exchange (ETDEWEB)

    Sondgeroth, A.

    1995-09-01

    This document describes what changes would be needed to lower the primary beams coming from switchyard into enclosure P01 without changing trajectories in the downstream enclosures. There is a 680 foot pipe buried in the ground between Enclosure E and P01 which allows primary beam to travel from the switchyard area to the research division area. This pipe is approximately 25 years old and has started to leak. The effects of the leaky pipe can be catastrophic to the transportation of the proton area beams. The vacuum group has devised an ingenious way of repairing a leak from the inside using remotely controlled grinders, patchers, welders and cameras mounted on carts that can be pulled into the pipe. A typical patch adds approximately one half of an inch of material which, in turn, restricts the aperture of the pipe. This pipe has three separate beams running through it split in the vertical plane. Pwest is the highest beam in the pipe and, in at least one location, the center of the beam clears the top of the pipe by one and one half inches. If a leak were to develop at a low spot in the pipe the patch to fix the leak might create an obstruction for the beam. Hence, the request from the Research Division Head.

  13. Classical mechanics without determinism

    OpenAIRE

    Nikolic, H.

    2005-01-01

    Classical statistical particle mechanics in the configuration space can be represented by a nonlinear Schrodinger equation. Even without assuming the existence of deterministic particle trajectories, the resulting quantum-like statistical interpretation is sufficient to predict all measurable results of classical mechanics. In the classical case, the wave function that satisfies a linear equation is positive, which is the main source of the fundamental difference between classical and quantum...

  14. Opportunizing: A classic grounded theory study on business and management

    Directory of Open Access Journals (Sweden)

    Ólavur Christiansen

    2006-11-01

    Full Text Available Opportunizing emerged as the core variable of this classic GT study on business and management. Opportunizing is the recurrent main concern that businesses have to continually resolve, and it explains how companies recurrently create, identify, seize or exploit situations to maintain their growth or survival. Opportunizing is the recurrent creation and re-creation of opportunities in business. Opportunizing is basically what business managers do and do all the time. The problematic nature of opportunizing is resolved by a core social process ofopportunizing and its attached sub-processes that account for change over time and for the variations of the problematic nature of its resolution.Opportunizing has five main facets. These are conditional befriending (confidence building & modifying behavior,prospecting (e.g. information gaining, weighing up (information appraisal & decision-making, moment capturing (quick intervention for seizing strategic opportunities, andconfiguration matching (adjusting the business organization to abet the other activities of opportunizing.On a more abstract level, opportunizing has three more organizational facets: the physically boundary-less, the valuehierarchical, and the physically bounded. The first of these called perpetual opportunizing. This emerges from the conjunction of conditional befriending and prospecting. The second facet is called triggering opportunizing. It arises from the coming together of weighing up and moment capturing. The final facet is called spasmodic opportunizing. This happens when moment capturing and configuration matching unite.

  15. A critical experimental study of the classical tactile threshold theory

    Directory of Open Access Journals (Sweden)

    Medina Leonel E

    2010-06-01

    Full Text Available Abstract Background The tactile sense is being used in a variety of applications involving tactile human-machine interfaces. In a significant number of publications the classical threshold concept plays a central role in modelling and explaining psychophysical experimental results such as in stochastic resonance (SR phenomena. In SR, noise enhances detection of sub-threshold stimuli and the phenomenon is explained stating that the required amplitude to exceed the sensory threshold barrier can be reached by adding noise to a sub-threshold stimulus. We designed an experiment to test the validity of the classical vibrotactile threshold. Using a second choice experiment, we show that individuals can order sensorial events below the level known as the classical threshold. If the observer's sensorial system is not activated by stimuli below the threshold, then a second choice could not be above the chance level. Nevertheless, our experimental results are above that chance level contradicting the definition of the classical tactile threshold. Results We performed a three alternative forced choice detection experiment on 6 subjects asking them first and second choices. In each trial, only one of the intervals contained a stimulus and the others contained only noise. According to the classical threshold assumptions, a correct second choice response corresponds to a guess attempt with a statistical frequency of 50%. Results show an average of 67.35% (STD = 1.41% for the second choice response that is not explained by the classical threshold definition. Additionally, for low stimulus amplitudes, second choice correct detection is above chance level for any detectability level. Conclusions Using a second choice experiment, we show that individuals can order sensorial events below the level known as a classical threshold. If the observer's sensorial system is not activated by stimuli below the threshold, then a second choice could not be above the chance

  16. Aging Trajectories in Different Body Systems Share Common Environmental Etiology: The Healthy Aging Twin Study (HATS).

    Science.gov (United States)

    Moayyeri, Alireza; Hart, Deborah J; Snieder, Harold; Hammond, Christopher J; Spector, Timothy D; Steves, Claire J

    2016-02-01

    Little is known about the extent to which aging trajectories of different body systems share common sources of variance. We here present a large twin study investigating the trajectories of change in five systems: cardiovascular, respiratory, skeletal, morphometric, and metabolic. Longitudinal clinical data were collected on 3,508 female twins in the TwinsUK registry (complete pairs:740 monozygotic (MZ), 986 dizygotic (DZ), mean age at entry 48.9 ± 10.4, range 18-75 years; mean follow-up 10.2 ± 2.8 years, range 4-17.8 years). Panel data on multiple age-related variables were used to estimate biological ages for each individual at each time point, in linear mixed effects models. A weighted average approach was used to combine variables within predefined body system groups. Aging trajectories for each system in each individual were then constructed using linear modeling. Multivariate structural equation modeling of these aging trajectories showed low genetic effects (heritability), ranging from 2% in metabolic aging to 22% in cardiovascular aging. However, we found a significant effect of shared environmental factors on the variations in aging trajectories in cardiovascular (54%), skeletal (34%), morphometric (53%), and metabolic systems (53%). The remainder was due to environmental factors unique to each individual plus error. Multivariate Cholesky decomposition showed that among aging trajectories for various body systems there were significant and substantial correlations between the unique environmental latent factors as well as shared environmental factors. However, there was no evidence for a single common factor for aging. This study, the first of its kind in aging, suggests that diverse organ systems share non-genetic sources of variance for aging trajectories. Confirmatory studies are needed using population-based twin cohorts and alternative methods of handling missing data.

  17. Histological Subgroups in Classic Kaposi Sarcoma: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Nilüfer Onak Kandemir

    2010-06-01

    Full Text Available Background and Design: Kaposi sarcomas (KS are vascular tumors with a low malignant potential which include overlapping infectious, immunologic, and neoplastic processes. Recently, many histological subtypes have been defined. Material and Method: In the present study, 151 cutaneous classic KS lesions in 56 patients were retrospectively evaluated with regard to histological subtypes. Determination of the subtypes was based on the predominant histopathological component in the lesion. We examined changes in epidermis and dermis along with intratumoral inflammatory response characteristics in the lesions. By defining histopathological variants of the cases, differences regarding subtypes were investigated. Results: Cases that bear the ordinary characteristics of KS and those that can not be classified otherwise, comprised 82..8% of the study group. Twenty-six cases showed consistency with the subtypes outlined in the literature in terms of their histopathological properties. The most common histological subtype was the lymphangiectatic variant in 7.3% of the cases. Bullous (2.6%, lymphangioma like (2.6%, intravascular (2%, and pyogenic granuloma like (2% variants were less common. The most uncommon histological subtype was micronodular (0.6% type. Lymphangiectatic, bullous, intravascular, and pyogenic granuloma like variants were frequently observed in the nodular stage of KSs. Lympangioma like changes were seen to be present in the early KS lesions. Lymphangiectatic type was oftenly associated with bullous component, whereas pyogenic granuloma like type demonstrated superficial ulceration and intense inflammatory response. Lymphangioma like and intravascular types exhibited a characteristic appearance, while other variants were accompanied by components belonging to different subtypes. Conclusion: In KS, histopathological subtypes can develop as a result of different pathological processes. The next stage of the current study, which is one of the

  18. An interdisciplinary study of the timbre of the classical guitar

    Science.gov (United States)

    Traube, Caroline

    This dissertation proposes an interdisciplinary approach for the study of the timbre of the classical guitar. We start by identifying the static; control parameters of timbre, relating to the structural components of the guitar and the dynamic control parameters of timbre, relating to the gestures applied by the performer on the instrument. From the plucked string physical model (obtained from the transverse wave equation), we derive a digital signal interpretation of the plucking effect which is a comb filtering. Then we investigate how subjective characteristics of sound, like timbre, are related to gesture parameters. The starting point for exploration is an inventory of verbal descriptors commonly used by professional musicians to describe the brightness, the colour, the shape and the texture of the sounds they produce on their instruments. An explanation for the voice-like nature of guitar tones is proposed based on the observation that the maxima of the comb-filter-shaped magnitude spectrum of guitar tones are located at frequencies similar to the formant frequencies of a subset of identifiable vowels. These analogies at the spectral level might account for the origin of some timbre descriptors such as open, oval, round, thin, closed, nasal and hollow, that seem to refer to phonetic gestures. In a experiment conducted to confirm these analogies, participants were asked to associate a consonant to the attack and a vowel to the decay of guitar tones. The results of this study support the idea that some perceptual dimensions of the guitar timbre space can be borrowed from phonetics. Finally, we address the problem of the indirect acquisition of instrumental gesture parameters. Pursuing previous research on the estimation of the plucking position from a recording, we propose a new estimation method based on an iterative weighted least-square algorithm, starting from a first approximation derived from a variant of the autocorrelation function of the signal.

  19. Trajectories of Substance Use Disorder in Youth After Detention: A 12-Year Longitudinal Study.

    Science.gov (United States)

    Welty, Leah J; Hershfield, Jennifer A; Abram, Karen M; Han, Hongyun; Byck, Gayle R; Teplin, Linda A

    2017-02-01

    To identify trajectories of substance use disorders (SUDs) in youth during the 12 years after detention and how gender, race/ethnicity, and age at baseline predict trajectories. As part of the Northwestern Juvenile Project, a longitudinal study of 1,829 youth randomly sampled from detention in Chicago, Illinois from 1995 through 1998, participants were reinterviewed in the community or correctional facilities up to 9 times over 12 years. Independent interviewers assessed SUDs using the Diagnostic Interview Schedule for Children 2.3 (baseline) and the Diagnostic Interview Schedule IV (follow-ups). Primary outcome was a mutually exclusive 5-category typology of disorder: no SUD, alcohol alone, marijuana alone, comorbid alcohol and marijuana, or "other" illicit ("hard") drug. Trajectories were estimated using growth mixture models with a 3-category ordinal variable derived from the typology. During the 12-year follow-up, 19.6% of youth did not have an SUD. The remaining 81.4% were in 3 trajectory classes. Class 1 (24.5%), a bell-shaped trajectory, peaked 5 years after baseline when 42.7% had an SUD and 12.5% had comorbid or "other" illicit drug disorders. Class 2 (41.3%) had a higher prevalence of SUD at baseline, 73.8%. Although prevalence decreased over time, 23.5% had an SUD 12 years later. Class 3 (14.6%), the most serious and persistent trajectory, had the highest prevalence of comorbid or "other" illicit drug disorders-52.1% at baseline and 17.4% 12 years later. Males, Hispanics, non-Hispanic whites, and youth who were older at baseline (detention) had the worst outcomes. Gender, race/ethnicity, and age at detention predict trajectories of SUDs in delinquent youth. Findings provide an empirical basis for child psychiatry to address health disparities and improve prevention. Copyright © 2016 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  20. A modelling and experimental study of the bubble trajectory in a non-Newtonian crystal suspension

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, N M S [Process Engineering and Light Metals (PELM) Centre, Faculty of Sciences, Engineering and Health, CQUniversity, Rockhampton, QLD 4702 (Australia); Khan, M M K; Rasul, M G, E-mail: m.rasul@cqu.edu.a [School of Engineering and Built Environment, Faculty of Sciences, Engineering and Health, CQUniversity, Rockhampton, QLD 4702 (Australia)

    2010-12-15

    This paper presents an experimental and computational study of air bubbles rising in a massecuite-equivalent non-Newtonian crystal suspension. The bubble trajectory inside the stagnant liquid of a 0.05% xanthan gum crystal suspension was investigated and modelled using the computational fluid dynamics (CFD) model to gain an insight into the bubble flow characteristics. The CFD code FLUENT was used for numerical simulation, and the bubble trajectory calculations were performed through a volume of fluid (VOF) model. The influences of the Reynolds number (Re), the Weber number (We) and the bubble aspect ratio (E) on the bubble trajectory are discussed. The conditions for the bubbles' path oscillations are identified. The experimental results showed that the path instability for the crystal suspension was less rapid than in water. The trajectory analysis indicated that 5.76 mm diameter bubbles followed a zigzag motion in the crystal suspension. Conversely, the smaller bubbles (5.76 mm) followed a path of least horizontal movement and larger bubbles (21.21 mm) produced more spiral motion within the crystal suspension. Path instability occurred for bubbles of 15.63 and 21.21 mm diameter, and they induced both zigzag and spiral trajectories within the crystal suspension. At low Re and We, smaller bubbles (5.76 mm) produced a zigzag trajectory, whereas larger bubbles (15.63 and 21.21 mm) showed both zigzag and spiral trajectories at intermediate and moderately high Re and We in the crystal suspension. The simulation results illustrated that a repeating pattern of swirling vortices was created for smaller bubbles due to the unstable wake and unsteady flow of these bubbles. This is the cause of the smaller bubbles moving in a zigzag way. Larger bubbles showed two counter-rotating trailing vortices at the back of the bubble. These vortices induced a velocity component to the gas-liquid interface and caused a deformation. Hence, the larger bubbles produced a path

  1. Classical Hodgkin lymphoma : population based studies on HLA and EBV

    NARCIS (Netherlands)

    Diepstra, Arjan

    2007-01-01

    Classical HL is a hematological malignancy in which immunological interactions are crucially involved. The neoplastic HRS cells use a variety of strategies to evade immune reactions, but also shape the immune response to their own benefit. Antigen presentation may be involved in both of these mechan

  2. Quantum-trajectory Monte Carlo method for study of electron-crystal interaction in STEM.

    Science.gov (United States)

    Ruan, Z; Zeng, R G; Ming, Y; Zhang, M; Da, B; Mao, S F; Ding, Z J

    2015-07-21

    In this paper, a novel quantum-trajectory Monte Carlo simulation method is developed to study electron beam interaction with a crystalline solid for application to electron microscopy and spectroscopy. The method combines the Bohmian quantum trajectory method, which treats electron elastic scattering and diffraction in a crystal, with a Monte Carlo sampling of electron inelastic scattering events along quantum trajectory paths. We study in this work the electron scattering and secondary electron generation process in crystals for a focused incident electron beam, leading to understanding of the imaging mechanism behind the atomic resolution secondary electron image that has been recently achieved in experiment with a scanning transmission electron microscope. According to this method, the Bohmian quantum trajectories have been calculated at first through a wave function obtained via a numerical solution of the time-dependent Schrödinger equation with a multislice method. The impact parameter-dependent inner-shell excitation cross section then enables the Monte Carlo sampling of ionization events produced by incident electron trajectories travelling along atom columns for excitation of high energy knock-on secondary electrons. Following cascade production, transportation and emission processes of true secondary electrons of very low energies are traced by a conventional Monte Carlo simulation method to present image signals. Comparison of the simulated image for a Si(110) crystal with the experimental image indicates that the dominant mechanism of atomic resolution of secondary electron image is the inner-shell ionization events generated by a high-energy electron beam.

  3. Ka-mixing in the unimolecular dissociation of NO 2 studied by classical dynamics calculations

    Science.gov (United States)

    Grebenshchikov, S. Yu; Flöthmann, H.; Schinke, R.; Bezel, I.; Wittig, C.; Kato, S.

    1998-03-01

    Coriolis and centrifugal vibration-rotation coupling in the unimolecular dissociation of ground electronic state NO 2 has been examined by using classical trajectories. The time evolution of the projection Ka of the rotational angular momentum N in a body-fixed frame is analyzed. The main result is a relation between the decomposition lifetime and the degree of Ka-mixing. For example, less than 30% of the available Ka space becomes populated for an average lifetime of 5 ps. This is consistent with the conclusions, based on time-resolved experiments, that rotation-vibration transfer is slower than reaction except just above the threshold.

  4. Outcomes of childhood conduct problem trajectories in early adulthood : findings from the ALSPAC study

    NARCIS (Netherlands)

    Kretschmer, Tina; Hickman, Matthew; Doerner, Rita; Emond, Alan; Lewis, Glyn; Macleod, John; Maughan, Barbara; Munafo, Marcus R.; Heron, Jon

    Although conduct problems in childhood are stably associated with problem outcomes, not every child who presents with conduct problems is at risk. This study extends previous studies by testing whether childhood conduct problem trajectories are predictive of a wide range of other health and behavior

  5. Trajectory dynamics study of the Ar + CH4 dissociation reaction at high temperatures: the importance of zero-point-energy effects.

    Science.gov (United States)

    Marques, J M C; Martínez-Núñez, E; Fernandez-Ramos, A; Vazquez, S A

    2005-06-23

    Large-scale classical trajectory calculations have been performed to study the reaction Ar + CH4--> CH3 +H + Ar in the temperature range 2500 energy surface used for ArCH4 is the sum of the nonbonding pairwise potentials of Hase and collaborators (J. Chem. Phys. 2001, 114, 535) that models the intermolecular interaction and the CH4 intramolecular potential of Duchovic et al. (J. Phys. Chem. 1984, 88, 1339), which has been modified to account for the H-H repulsion at small bending angles. The thermal rate coefficient has been calculated, and the zero-point energy (ZPE) of the CH3 product molecule has been taken into account in the analysis of the results; also, two approaches have been applied for discarding predissociative trajectories. In both cases, good agreement is observed between the experimental and trajectory results after imposing the ZPE of CH3. The energy-transfer parameters have also been obtained from trajectory calculations and compared with available values estimated from experiment using the master equation formalism; in general, the agreement is good.

  6. A quasi-classical study of energy transfer in collisions of hyperthermal H atoms with SO2 molecules

    Science.gov (United States)

    da Silva, Ramon S.; Garrido, Juan D.; Ballester, Maikel Y.

    2017-08-01

    A deep understanding of energy transfer processes in molecular collisions is at central attention in physical chemistry. Particularly vibrational excitation of small molecules colliding with hot light atoms, via a metastable complex formation, has shown to be an efficient manner of enhancing reactivity. A quasi-classical trajectory study of translation-to-vibration energy transfer (T-V ET) in collisions of hyperthermal H(2S) atoms with SO2(X˜ 1A') molecules is presented here. For such a study, a double many-body expansion potential energy surface previously reported for HSO2(2A) is used. This work was motivated by recent experiments by Ma et al. studying collisions of H + SO2 at the translational energy of 59 kcal/mol [J. Ma et al., Phys. Rev. A 93, 040702 (2016)]. Calculations reproduce the experimental evidence that during majority of inelastic non-reactive collision processes, there is a metastable intermediate formation (HOSO or HSO2). Nevertheless, the analysis of the trajectories shows that there are two distinct mechanisms in the T-V ET process: direct and indirect. Direct T-V processes are responsible for the high population of SO2 with relatively low vibrational excitation energy, while indirect ones dominate the conversion from translational energy to high values of the vibrational counterpart.

  7. Research Review: A Critical Review of Studies on the Developmental Trajectories of Antisocial Behavior in Females

    Science.gov (United States)

    Fontaine, Nathalie; Carbonneau, Rene; Vitaro, Frank; Barker, Edward D.; Tremblay, Richard E.

    2009-01-01

    Background: Knowledge on the onset and the development of antisocial behavior in females is limited, because most of the research in this domain is based on males. Methods: We critically reviewed 46 empirical studies that examined developmental trajectories of antisocial behavior in females, notably to help determine whether or not an…

  8. Developmental trajectories of social participation in individuals with cerebral palsy : A multicentre longitudinal study

    NARCIS (Netherlands)

    Tan, Siok Swan; Wiegerink, Diana J H G; Vos, Rimke C.; Smits, Dirk Wouter; Voorman, Jeanine M.; Twisk, Jos W R; Ketelaar, Marjolijn; Roebroeck, Marij E.; Dallmeijer, A. J.; Vos, R. C.; Van Eck, M.; Van Schie, P.; Voorman, J. M.; Becher, J. G.; Schuengel, C.; Ketelaar, M.; Smits, D. W.; Lindeman, E.; Jongmans, M.; Roebroeck, M. E.; Tan, S. S.; Wiegerink, D. J H G; Van Meeteren, J.; Reinders-Messelink, H. A.; Gorter, J. W.; Verheijden, J.

    2014-01-01

    Aim: This study aimed to determine the developmental trajectories of social participation, by level of gross motor function and intellectual disability, in a Dutch population of individuals with cerebral palsy (CP) aged 1 to 24 years. Method: As part of the Pediatric Rehabilitation Research in the N

  9. Career Trajectories of Dutch Pop Musicians: A Longitudinal Study

    Science.gov (United States)

    Zwaan, Koos; ter Bogt, Tom F. M.; Raaijmakers, Quinten

    2010-01-01

    Systematic studies of artistic careers are scarce and this is the first large-scale study on the career development of pop musicians. Using a prospective longitudinal approach we followed a sample of aspiring pop musicians in the Netherlands (N=369) over a three-year period. First we identified four groups of pop musicians with different career…

  10. Career Trajectories of Dutch Pop Musicians: A Longitudinal Study

    Science.gov (United States)

    Zwaan, Koos; ter Bogt, Tom F. M.; Raaijmakers, Quinten

    2010-01-01

    Systematic studies of artistic careers are scarce and this is the first large-scale study on the career development of pop musicians. Using a prospective longitudinal approach we followed a sample of aspiring pop musicians in the Netherlands (N=369) over a three-year period. First we identified four groups of pop musicians with different career…

  11. Trajectories of schizotypy and their emotional and social functioning: An 18-month follow-up study.

    Science.gov (United States)

    Wang, Yi; Shi, Hai-Song; Liu, Wen-Hua; Xie, Dong-Jie; Geng, Fu-Lei; Yan, Chao; Wang, Ya; Xiao, Ya-Hui; So, Suzanne H W; Chiu, Chui-De; Leung, Patrick W L; Cheung, Eric F C; Gooding, Diane C; Chan, Raymond C K

    2017-07-24

    Schizotypy is a set of personality traits that convey liability to develop schizophrenia. Studying schizotypy in healthy individuals may facilitate the understanding of the psychopathological processes underlying schizophrenia. The present study aimed to examine the developmental trajectories of schizotypy over time using a longitudinal study design. The Chapman Scales for Psychosis Proneness were administered to 1541 college students at baseline, and subsequently at six-monthly intervals up to 18months. Latent class growth analysis was conducted to track the different trajectories. In addition, self-reported scales were used to measure idea of reference, emotional experiences and expression, stress and coping, as well as social functioning. We identified four latent classes with distinct trajectories: "nonschizotypy" group (LC1), "stable high schizotypy" group (LC3), "high reactive schizotypy" group (LC2) and "low reactive schizotypy" group (LC4). These findings suggest that there may be distinct developmental trajectories for schizotypy. Two groups may be of particular interest: the "stable high schizotypy" group that displayed the worst clinical and functioning outcomes on almost all measures and the "high reactive schizotypy" group characterized by a relatively rapid decline in functioning. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Epigenetic profiling of ADHD symptoms trajectories: A prospective, methylome-wide study

    Science.gov (United States)

    Walton, Esther; Pingault, Jean-Baptiste; Cecil, Charlotte AM; Gaunt, Tom R.; Relton, Caroline; Mill, Jonathan; Barker, Edward D.

    2016-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is a prevalent developmental disorder, associated with a range of long-term impairments. Variation in DNA methylation, an epigenetic mechanism, is implicated in both neurobiological functioning and psychiatric health. However, the potential role of DNA methylation in ADHD symptoms is currently unclear. In this study, we examined data from the Avon Longitudinal Study of Parents and Children (ALSPAC) – specifically the subsample forming the Accessible Resource for Integrated Epigenomics Studies (ARIES) – which includes (i) peripheral measures of DNA methylation (Illumina 450k) at birth (n=817, 49% male) and age 7 (n=892, 50% male) and (ii) trajectories of ADHD symptoms (7-15 yrs). We first employed a genome-wide analysis to test whether DNA methylation at birth associates with later ADHD trajectories; and then followed up at age 7 to investigate the stability of associations across early childhood. We found that DNA methylation at birth differentiated ADHD trajectories across multiple genomic locations, including probes annotated to SKI (involved in neural tube development), ZNF544 (previously implicated in ADHD), ST3GAL3 (linked to intellectual disability) and PEX2 (related to perixosomal processes). None of these probes maintained an association with ADHD trajectories at age 7. Findings lend novel insights into the epigenetic landscape of ADHD symptoms, highlighting the potential importance of DNA methylation variation in genes related to neurodevelopmental and peroxisomal processes, which play a key role in the maturation and stability of cortical circuits. PMID:27217153

  13. Mixing in classical novae: a 2-D sensitivity study

    CERN Document Server

    Casanova, Jordi; Garcia-Berro, Enrique; Calder, Alan; Shore, Steven N

    2010-01-01

    Classical novae are explosive phenomena that take place in stellar binary systems. They are powered by mass transfer from a low-mass, main sequence star onto a white dwarf. The material piles up under degenerate conditions and a thermonuclear runaway ensues. The energy released by the suite of nuclear processes operating at the envelope heats the material up to peak temperatures of ~ (1 - 4) \\times 108 K. During these events, about 10-4 - 10-5 M\\odot, enriched in CNO and other intermediate-mass elements, are ejected into the interstellar medium. To account for the gross observational properties of classical novae (in particular, a metallicity enhancement in the ejecta above solar values), numerical models assume mixing between the (solar-like) material transferred from the companion and the outermost layers (CO- or ONe-rich) of the underlying white dwarf. The nature of the mixing mechanism that operates at the core-envelope interface has puzzled stellar modelers for about 40 years. Here we investigate the rol...

  14. Using Large Data Sets to Study College Education Trajectories

    Science.gov (United States)

    Oseguera, Leticia; Hwang, Jihee

    2014-01-01

    This chapter presents various considerations researchers undertook to conduct a quantitative study on low-income students using a national data set. Specifically, it describes how a critical quantitative scholar approaches guiding frameworks, variable operationalization, analytic techniques, and result interpretation. Results inform how…

  15. Characterizing Resilience and Growth Among Soldiers: A Trajectory Study

    Science.gov (United States)

    2014-04-01

    Psychology in the Classroom : A Case of Positive Psychology Intervention for Special Education in High School. Poster presentation. 2013 International... meditation can boost immune function.53 Psychosocial resilience training targeting positive emotions, cognitive flexibility, social support, life meaning...mindfulness meditation . It is assumed that meditations induce positive affect and lead to good health. A study led by a neuroscientist, Richard Davidson

  16. From reception of classics to outreach: classical reception and American response to war. A case study. Part II

    Directory of Open Access Journals (Sweden)

    Rosanna Lauriola

    2014-05-01

    Full Text Available After providing a theoretical framework pertaining to the field of Reception of Classic in the first part of this essay (LAURIOLA, 2014 and after discussing some related issues from a pedagogical viewpoint, I introduced, as case study, works and initiatives by a psychiatrist (SHAY, 1991, 1994, 2002, an American director (DOERRIES, 2008, and two scholars (MEINECK, 2010a, b, 2012; TRITLE, 1998, 2000, 2010 who have been proposing a use of Classical Literature as a therapeutic and awareness-raising tool in response to the problems that modern wars have been causing. Veterans and their family, as well as the whole civic community, are the addressees of their work. What follows is a detailed analysis of those works with the intention both to determine whether they can be classified as work of reception – which, so far, has never been proposed – and to discuss the plausibility of this kind of reception, which also turns into social outreach, and how it can be proposed without risking to completely dismiss changes that have occurred in the vision of war, although we may agree that the sufferings of war did not change too much1. Like in the first part, the discussion will be also carried on within a pedagogical discourse. A personal note based on a personal experience will conclude the analysis.

  17. 10-year trajectories of depressive symptoms and risk of dementia: a population-based study.

    Science.gov (United States)

    Mirza, Saira Saeed; Wolters, Frank J; Swanson, Sonja A; Koudstaal, Peter J; Hofman, Albert; Tiemeier, Henning; Ikram, M Arfan

    2016-07-01

    Late-life depressive symptoms have been extensively studied for their relationship with incident dementia, but have been typically assessed at a single timepoint. Such an approach neglects the course of depression, which, given its remitting and relapsing nature, might provide further insights into the complex association of depression with dementia. We therefore repeatedly measured depressive symptoms in a population of adults over a decade to study the subsequent risk of dementia. Our study was embedded in the Rotterdam Study, a population-based study of adults aged 55 years or older in Rotterdam (Netherlands), ongoing since 1990. The cohort is monitored continuously for major events by data linkage between the study database and general practitioners. We examined a cohort of participants who were free from dementia, but had data for depressive symptoms from at least one examination round in 1993-95, 1997-99, or 2002-04. We assessed depressive symptoms with the validated Dutch version of the Center for Epidemiology Depression Scale (CES-D) and the Hospital Anxiety and Depression Scale-Depression. We used these data to identify 11-year trajectories of depressive symptoms by latent class trajectory modelling. We screened participants for dementia at each examination round and followed up participants for 10 years for incident dementia by latent trajectory from the third examination round to 2014. We calculated hazard ratios (HR) for dementia by assigned trajectory using two Cox proportional hazards models (model 1 adjusted for age and sex only, and model 2 adjusted additionally for APOEɛ4 carrier status, educational level, body-mass index, smoking, alcohol consumption, cognitive score, use of antidepressants, and prevalent disease status at baseline). We repeated the analyses censoring for incident stroke, restricting to Alzheimer's disease as an outcome, and accounting for mortality as a competing risk for dementia. From 1993-2004, we obtained data for depressive

  18. Classic and New Materials Used for Structural Rehabilitation. Case Study

    Science.gov (United States)

    Lute, M.

    2016-06-01

    New materials development with different combination of properties were always a challenge in terms of their adequate use in civil engineering. Introduction of carbon fibres as strength material for structures was a beginning of a new approach in structural rehabilitation, and sometimes meant the end of classic rehabilitation solution use. The present paper gives an example of a building rehabilitation that use a melt of both new and old solutions in order to achieve the optimum result for building itself. The problem was even more challenging, because the structure considered is only 22 years old, but having some design faults in terms of seismic behaviour and, in addition, one floor was added to existing structure. The chosen solution was a compromise between the use of old and new materials in places where their qualities were best suitable and their minuses could be compensated by the other material.

  19. Computing with spatial trajectories

    CERN Document Server

    2011-01-01

    Covers the fundamentals and the state-of-the-art research inspired by the spatial trajectory data Readers are provided with tutorial-style chapters, case studies and references to other relevant research work This is the first book that presents the foundation dealing with spatial trajectories and state-of-the-art research and practices enabled by trajectories

  20. O método das trajectórias clássicas: colisões coplanares do tipo A+BC Classical trajectory method: A+BC coplanar collisions

    Directory of Open Access Journals (Sweden)

    Jorge M. C. Marques

    2003-10-01

    Full Text Available The general methodology of classical trajectories as applied to elementary chemical reactions of the A+BC type is presented. The goal is to elucidate students about the main theoretical features and potentialities in applying this versatile method to calculate the dynamical properties of reactive systems. Only the methodology for two-dimensional (2D case is described, from which the general theory for 3D follows straightforwardly. The adopted point of view is, as much as possible, that of allowing a direct translation of the concepts into a working program. An application to the reaction O(¹D+H2->O+OH with relevance in atmospheric chemistry is also presented. The FORTRAN codes used are available through the web page www.qqesc.qui.uc.pt.

  1. Exploratory studies of classical conditioning of the preoral cavity in harnessed carpenter ants (Camponotus pennsylvanicus).

    Science.gov (United States)

    Sauer, Dustin L; Abramson, Charles I; Lawson, Adam L

    2002-06-01

    An attempt was made to classically condition the mouthparts of harnessed worker ants (Camponotus pennsylvanicus) in anticipation of feeding. Experiments were designed to investigate classical conditioning with one CS, discrimination between two CSs, and pseudoconditioning. Analysis indicated a small acquisition effect that could be accounted for by pseudoconditioning. The preparation can be used to study nonassociative learning and some instrumental conditioning situations.

  2. Classical and Quantum Mechanical Motion in Magnetic Fields

    CERN Document Server

    Franklin, J

    2016-01-01

    We study the motion of a particle in a particular magnetic field configuration both classically and quantum mechanically. For flux-free radially symmetric magnetic fields defined on circular regions, we establish that particle escape speeds depend, classically, on a gauge-fixed magnetic vector potential, and demonstrate some trajectories associated with this special type of magnetic field. Then we show that some of the geometric features of the classical trajectory (perpendicular exit from the field region, trapped and escape behavior) are reproduced quantum mechanically using a numerical method that extends the norm-preserving Crank-Nicolson method to problems involving magnetic fields. While there are similarities between the classical trajectory and the position expectation value of the quantum mechanical solution, there are also differences, and we demonstrate some of these.

  3. Theodor Meynert's contribution to classical 19th century aphasia studies.

    Science.gov (United States)

    Whitaker, H A; Etlinger, S C

    1993-11-01

    Carl Wernicke (1848-1905) is traditionally considered the first to have described the features of, and the brain pathology underlying, impaired auditory comprehension and related symptoms. Although Wernicke (1874) clearly and repeatedly indicates his indebtedness to Theodor von Meynert (1833-1892), this is usually understood as an acknowledgment that Meynert taught Wernicke neuroanatomy (Eggert, 1977); Wernicke's own words in part support this interpretation. A more sophisticated historical analysis notes that, prior to Wernicke, both Johann Schmidt in 1871 and Charlton Bastian in 1869 had described the concept of receptive aphasia, but neither had supported their analyses with autopsy evidence as did Wernicke, thus not dislodging Wernicke's claim of priority. However, a virtually unknown work by Theodor von Meynert, published in 1866, has recently been rediscovered by us ["Ein Fall von Sprachstörung, anatomisch begründet." Medizinische Jahrbücher. XII Band der Zeitschrift der K. K. Gesellleschaft der Arzte in Wien, 22. Jahr. Pp. 152-189]. In this paper Meynert analyzes the anatomical basis for localizing the comprehension of language in the superior temporal gyrus, he argues that lesions in this area should (by analogy to Broca's earlier observations on language expression) cause impairments in language comprehension, and he presents a case of receptive aphasia with autopsy evidence of destruction of the superior temporal gyrus in the left hemisphere. The patient's aphasia was classic; impaired auditory comprehension, and fluent speech with paraphasias. It is clear that Meynert should be given historical credit for his work.

  4. Depressive symptom trajectories in women affected by breast cancer and their male partners : a nationwide prospective cohort study

    NARCIS (Netherlands)

    Rottmann, Nina; Hansen, Dorte Gilsa; Hagedoorn, Mariet; Larsen, Pia Veldt; Nicolaisen, Anne; Bidstrup, Pernille Envold; Wurtzen, Hanne; Flyger, Henrik; Kroman, Niels; Johansen, Christoffer

    2016-01-01

    The purpose of this study was to identify subgroups of breast cancer patients and their partners based on distinct trajectories of depressive symptoms, to examine how relationship quality and medical and sociodemographic factors were associated with these trajectories, and to explore whether

  5. Study of Mechanical Model of Sports Ball’S Flight Trajectory and Its Application

    Directory of Open Access Journals (Sweden)

    Xiaoyan Yu

    2013-05-01

    Full Text Available In order to resolve the controversy of ball games the placement problem fined on the other hand, to promote the teaching and training ball flight trajectory. Tennis is the main object of study, use of literature, mathematical statistics and experimental research methods and to establish an appropriate mathematical model, using MATLAB software to accurately determine the trajectory and impact point of the ball's flight, used in teaching, training and competition in. The conclusions show that the law, accurate data analysis using MATLAB software can simulate the flight of the ball moving on sports development has a very good help provide a new way of thinking for the in-depth study the pattern of winning ball games and similar sports teaching, training and selection of athletes is an important complementary and valuable.

  6. Effect of Helicobacter pylori infection on growth trajectories in young Ethiopian children: a longitudinal study

    OpenAIRE

    Bineyam Taye; Fikre Enquselassie; Aster Tsegaye; Alemayehu Amberbir; Girmay Medhin; Andrew Fogarty; Karen Robinson; Gail Davey

    2016-01-01

    Background: Helicobacter pylori infection has been associated with early childhood growth impairment in high- and middle-income countries; however, few studies have examined this relationship within low-income countries or have used a longitudinal design. The possible effects of H. pylori infection on growth trajectories were examined in a cohort of young Ethiopian children. Methods: In 2011/12, 856 children (85.1% of the 1006 original singletons in a population-based birth cohort) were fo...

  7. Trends and Findings in Trajectory Studies: a Methodological Approach to Classify Labor Development

    Directory of Open Access Journals (Sweden)

    Mariela Sonia Jiménez Vásquez

    2009-05-01

    Full Text Available Trajectory studies are a methodological option that helps to completely analyze labor paths forged by individuals in the labor market. However, when initiating a research in this topic there are several different scopes, discipline approaches, objects and purposes of research, which hinder its comprehension. This article presents the main trends established to guide this type of research and some of the theoretical and methodological elements found in its structure.

  8. Human Spaceflight Trajectory Operations: A Case Study from STS-132/ULF4

    Science.gov (United States)

    Cutri-Kohart, Rebecca; Browns, Ansley

    2010-01-01

    Prior to the launch of the STS-132/ULF4 mission, the International Space Station (ISS) Flight Control Team was alerted to the approach of a space debris with a predicted time of closest approach approximately 1 hr after Space Shuttle docking. As a result, the ISS team considered performing a collision avoidance maneuver prior to the Space Shuttle s approach. The purpose of this presentation will be to use this case study to illustrate best practices of the human spaceflight trajectory operations team. The presentation will begin with an overview of the roles of the real-time ISS and Space Shuttle trajectory flight control teams. Then, the STS-132/ULF4 case study will be used to illustrate the issues and lessons learned involved in performing Space Shuttle rendezvous maneuver planning and execution. Specific elements of the STS-132 Space Shuttle rendezvous maneuver profile that can be used to provide mission assurance in cases of trajectory uncertainty will be described and discussed. Additionally, this case study will be used to provide context for identifying lessons learned in an operational environment that requires technical and decision-making coordination between two control center teams with two potentially maneuvering space vehicles.

  9. Meteorological and Back Trajectory Modeling for the Rocky Mountain Atmospheric Nitrogen and Sulfur Study II

    Directory of Open Access Journals (Sweden)

    Kristi A. Gebhart

    2014-01-01

    Full Text Available The Rocky Mountain Atmospheric Nitrogen and Sulfur (RoMANS II study with field operations during November 2008 through November 2009 was designed to evaluate the composition and sources of reactive nitrogen in Rocky Mountain National Park, Colorado, USA. As part of RoMANS II, a mesoscale meteorological model was utilized to provide input for back trajectory and chemical transport models. Evaluation of the model's ability to capture important transport patterns in this region of complex terrain is discussed. Previous source-receptor studies of nitrogen in this region are also reviewed. Finally, results of several back trajectory analyses for RoMANS II are presented. The trajectory mass balance (TrMB model, a receptor-based linear regression technique, was used to estimate mean source attributions of airborne ammonia concentrations during RoMANS II. Though ammonia concentrations are usually higher when there is transport from the east, the TrMB model estimates that, on average, areas to the west contribute a larger mean fraction of the ammonia. Possible reasons for this are discussed and include the greater frequency of westerly versus easterly winds, the possibility that ammonia is transported long distances as ammonium nitrate, and the difficulty of correctly modeling the transport winds in this area.

  10. Classical and semiclassical aspects of chemical dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Gray, S.K.

    1982-08-01

    Tunneling in the unimolecular reactions H/sub 2/C/sub 2/ ..-->.. HC/sub 2/H, HNC ..-->.. HCN, and H/sub 2/CO ..-->.. H/sub 2/ + CO is studied with a classical Hamiltonian that allows the reaction coordinate and transverse vibrational modes to be considered directly. A combination of classical perturbation theory and the semiclassical WKB method allows tunneling probabilities to be obtained, and a statistical theory (RRKM) is used to construct rate constants for these reactions in the tunneling regime. In this fashion, it is found that tunneling may be important, particularly for low excitation energies. Nonadiabatic charge transfer in the reaction Na + I ..-->.. Na /sup +/ + I/sup -/ is treated with classical trajectories based on a classical Hamiltonian that is the analogue of a quantum matrix representation. The charge transfer cross section obtained is found to agree reasonably well with the exact quantum results. An approximate semiclassical formula, valid at high energies, is also obtained. The interaction of radiation and matter is treated from a classical viewpoint. The excitation of an HF molecule in a strong laser is described with classical trajectories. Quantum mechanical results are also obtained and compared to the classical results. Although the detailed structure of the pulse time averaged energy absorption cannot be reproduced classically, classical mechanics does predict the correct magnitude of energy absorption, as well as certain other qualitative features. The classical behavior of a nonrotating diatomic molecule in a strong laser field is considered further, by generating a period advance map that allows the solution over many periods of oscillation of the laser to be obtained with relative ease. Classical states are found to form beautiful spirals in phase space as time progresses. A simple pendulum model is found to describe the major qualitative features. (WHM)

  11. Classical and semiclassical aspects of chemical dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Gray, S.K.

    1982-08-01

    Tunneling in the unimolecular reactions H/sub 2/C/sub 2/ ..-->.. HC/sub 2/H, HNC ..-->.. HCN, and H/sub 2/CO ..-->.. H/sub 2/ + CO is studied with a classical Hamiltonian that allows the reaction coordinate and transverse vibrational modes to be considered directly. A combination of classical perturbation theory and the semiclassical WKB method allows tunneling probabilities to be obtained, and a statistical theory (RRKM) is used to construct rate constants for these reactions in the tunneling regime. In this fashion, it is found that tunneling may be important, particularly for low excitation energies. Nonadiabatic charge transfer in the reaction Na + I ..-->.. Na /sup +/ + I/sup -/ is treated with classical trajectories based on a classical Hamiltonian that is the analogue of a quantum matrix representation. The charge transfer cross section obtained is found to agree reasonably well with the exact quantum results. An approximate semiclassical formula, valid at high energies, is also obtained. The interaction of radiation and matter is treated from a classical viewpoint. The excitation of an HF molecule in a strong laser is described with classical trajectories. Quantum mechanical results are also obtained and compared to the classical results. Although the detailed structure of the pulse time averaged energy absorption cannot be reproduced classically, classical mechanics does predict the correct magnitude of energy absorption, as well as certain other qualitative features. The classical behavior of a nonrotating diatomic molecule in a strong laser field is considered further, by generating a period advance map that allows the solution over many periods of oscillation of the laser to be obtained with relative ease. Classical states are found to form beautiful spirals in phase space as time progresses. A simple pendulum model is found to describe the major qualitative features. (WHM)

  12. Trajectories of PTSD risk and resilience in World Trade Center responders: an 8-year prospective cohort study.

    Science.gov (United States)

    Pietrzak, R H; Feder, A; Singh, R; Schechter, C B; Bromet, E J; Katz, C L; Reissman, D B; Ozbay, F; Sharma, V; Crane, M; Harrison, D; Herbert, R; Levin, S M; Luft, B J; Moline, J M; Stellman, J M; Udasin, I G; Landrigan, P J; Southwick, S M

    2014-01-01

    Longitudinal symptoms of post-traumatic stress disorder (PTSD) are often characterized by heterogeneous trajectories, which may have unique pre-, peri- and post-trauma risk and protective factors. To date, however, no study has evaluated the nature and determinants of predominant trajectories of PTSD symptoms in World Trade Center (WTC) responders. A total of 10835 WTC responders, including 4035 professional police responders and 6800 non-traditional responders (e.g. construction workers) who participated in the WTC Health Program (WTC-HP), were evaluated an average of 3, 6 and 8 years after the WTC attacks. Among police responders, longitudinal PTSD symptoms were best characterized by four classes, with the majority (77.8%) in a resistant/resilient trajectory and the remainder exhibiting chronic (5.3%), recovering (8.4%) or delayed-onset (8.5%) symptom trajectories. Among non-traditional responders, a six-class solution was optimal, with fewer responders in a resistant/resilient trajectory (58.0%) and the remainder exhibiting recovering (12.3%), severe chronic (9.5%), subsyndromal increasing (7.3%), delayed-onset (6.7%) and moderate chronic (6.2%) trajectories. Prior psychiatric history, Hispanic ethnicity, severity of WTC exposure and WTC-related medical conditions were most strongly associated with symptomatic trajectories of PTSD symptoms in both groups of responders, whereas greater education and family and work support while working at the WTC site were protective against several of these trajectories. Trajectories of PTSD symptoms in WTC responders are heterogeneous and associated uniquely with pre-, peri- and post-trauma risk and protective factors. Police responders were more likely than non-traditional responders to exhibit a resistant/resilient trajectory. These results underscore the importance of prevention, screening and treatment efforts that target high-risk disaster responders, particularly those with prior psychiatric history, high levels of

  13. A comparative study of visual and thermal comfort in prefabricated and classically built kindergarten

    OpenAIRE

    2013-01-01

    In this thesis a comparative study of visual and thermal comfort in prefabricated and classically built kindergarten in Grosuplje are presented. Visual and thermal comfort in the selected room of classically and prefabricated built kindergarten was estimated by site measuring, calculations and questionnaires. The thesis includes review of legislation in this field, review of existing studies, the methodology and the results of a comparative analysis. Furthermore, proposals for improvements in...

  14. Compressing spatio-temporal trajectories

    DEFF Research Database (Denmark)

    Gudmundsson, Joachim; Katajainen, Jyrki; Merrick, Damian

    2009-01-01

    A trajectory is a sequence of locations, each associated with a timestamp, describing the movement of a point. Trajectory data is becoming increasingly available and the size of recorded trajectories is getting larger. In this paper we study the problem of compressing planar trajectories such tha...

  15. A Complete Reanalysis of Horner's Classic "Fear of Success" Study.

    Science.gov (United States)

    Brandt, David A.; Kline, Kay H.

    The well-known study on fear of success (FOS) by Horner (1968) asserted that women low in FOS do better on achievement-oriented tasks under competitive conditions, while women high in the motive do better when the situation is non-competitive. This paper critically reviews the methodology of this study and concludes that the statistical test…

  16. Is Project Management Still an Accidental Profession? A Qualitative Study of Career Trajectory

    Directory of Open Access Journals (Sweden)

    Tracey M. Richardson

    2015-02-01

    Full Text Available In this study, the authors used qualitative techniques to look for reoccurring themes related to 87 project managers’ responses to interview questions associated with entry into the field of project management and career progression. The study found that despite the efforts of higher education, professional associations, and their professional development and certifications, the project management remains a destination by accident. Professional project managers do not intend to be project managers but “fall into” the profession. This study provides a conceptual framework for project manager career trajectory that has implications for project management training and mentoring and contributes to the growing literature on the accidental profession.

  17. Employment Trajectories After Spinal Cord Injury : Results From a 5-Year Prospective Cohort Study

    NARCIS (Netherlands)

    Ferdiana, Astri; Post, Marcel W.; Hoekstra, Trynke; van der Woude, Luccas H.; van der Klink, Jac J.; Bultmann, Ute

    2014-01-01

    Objectives: To identify different employment trajectories in individuals with spinal cord injury (SCI) after discharge from initial rehabilitation and to determine predictors of different trajectories from demographic, injury, functional, and psychological characteristics. Design: Prospective cohort

  18. Classical Civilization, English, Social Studies: 5114.67.

    Science.gov (United States)

    Hankins, Gretchen C.

    This course will include the study of Greek mythology, philosophy, and drama and analyze their influence on modern man and his ideas. The course outline consists of: I. Performance Objectives; II. Range of Subject Matter; III. Course Content; IV. Teaching Strategies and Learning Activities; V. Student Resources -- a list of books relevant to Greek…

  19. Revisiting a Classic Study of the Molecular Clock.

    Science.gov (United States)

    Robinson, Lauren M; Boland, Joseph R; Braverman, John M

    2016-03-01

    A constant rate of molecular evolution among homologous proteins and across lineages is known as the molecular clock. This concept has been useful for estimating divergence times. Here, we revisit a study by Richard Dickerson (J Mol Evol 1:26-45, 1971), wherein he provided striking visual evidence for a constant rate of amino acid changes among various evolutionary branch points. Dickerson's study is commonly cited as support of the molecular clock and a figure from it is often reproduced in textbooks. Since its publication, however, there have been updates made to dates of common ancestors based on the fossil record that should be considered. Additionally, collecting the accession numbers and carefully outlining Dickerson's methods serves as a resource to students of the molecular clock hypothesis.

  20. Reaction of protonated tyrosine with electronically excited singlet molecular oxygen (a1Delta(g)): an experimental and trajectory study.

    Science.gov (United States)

    Fang, Yigang; Liu, Jianbo

    2009-10-22

    Reaction of protonated tyrosine with the lowest electronically excited singlet state of molecular oxygen, (1)O(2) (a(1)Delta(g)), is reported over the center-of-mass collision energy (E(col)) range from 0.1 to 3.0 eV, using an electrospray-ionization, guided-ion-beam scattering instrument, in conjunction with ab initio electronic structure calculations and direct dynamics trajectory simulations. Only one product channel is observed, corresponding to generation of hydrogen peroxide via transfer of two hydrogen atoms from protonated tyrosine. Despite being exoergic, the reaction is in competition with physical quenching of (1)O(2) and is very inefficient. At low E(col), the reaction may be mediated by intermediate complexes and shows strong inhibition by collision energy. At high E(col), the reaction efficiency drops to approximately 1% and starts to have contribution from a direct mechanism. Quasi-classical trajectory simulations were performed to probe the mechanism at high collision energies. Analysis of trajectories shows that, at E(col) of 3.0 eV, a small fraction of hydrogen peroxide (25%) is produced via a direct, concerted mechanism where two hydrogen atoms are transferred simultaneously, but most hydrogen peroxide (75%) is formed by dissociation of hydroperoxide intermediates. According to ab initio calculations and trajectory simulations, collisions also lead to formation of various endoperoxides, and dissociation of endoperoxides may play a role in physical quenching of (1)O(2). The apparatus and experimental techniques are described in detail.

  1. A comparative study of the classic and piggyback techniques for orthotopic liver transplantation

    Directory of Open Access Journals (Sweden)

    Saman Nikeghbalian

    2014-02-01

    Full Text Available Background: The classic technique of hepatectomy with venovenous bypass may cause a longer anhepatic phase and increase the rate of some complications, such as post-operative renal failure and thromboembolic events. But, in some cases, such as tumors and anatomic difficulties, the surgeon is obligated to use the classic technique even though there is some controversy about the safety of this technique without venovenous bypass in liver transplantation. The aim of this study was to compare the results of using the classic technique without venovenous bypass and the piggyback technique for liver transplantation. Methods: A retrospective case-series study was conducted on 227 consecutive successful liver transplants, including 55 cases in which the classic technique was used and 172 cases in which the piggyback technique was used. The transplants were performed from March 2010 through June 2011 in the Visceral Transplantation Ward at Namazi Hospital in Shiraz, Iran. The piggyback method was the preferred approach for hepatectomy, but the classic technique without venovenous bypass was performed in cirrhotic cases with anatomic difficulties, when there was a tumor, or when the surgeon preferred it. Results: There were no significant differences in post-operative rise in creatinine, decreases in intraoperative blood pressure, transfused packed red blood cells (RBC, or survival rates between the groups. Warm ischemic time (duration that donor liver is out of ice until it’s blood reperfusion in the recipient was approximately seven minutes longer in the classic group (P = 0, but it was less than 52 minutes, which is an acceptable time for this phase. Hospital stays were shorter in the classic group than in the piggyback group (P = 0.024. Conclusion: Although the piggyback technique is the preferred technique for hepatectomy in liver transplantation, the classic technique without venovenous bypass can be used safely in cirrhotic livers when necessary

  2. The enduring effect of education-socioeconomic differences in disability trajectories from age 85 years in the Newcastle 85+ Study

    Science.gov (United States)

    Kingston, Andrew; Davies, Karen; Collerton, Joanna; Robinson, Louise; Duncan, Rachel; Kirkwood, Thomas B.L.; Jagger, Carol

    2015-01-01

    Objective Little is known about disability progression in very old age despite this being vital for care planning. We investigate whether distinct trajectories of disability are evident from age 85 to 90 and their association with socio-economic status (SES). Methods The Newcastle 85+ Study recruited people born in 1921 through participating general practices in Newcastle and North Tyneside. Participants underwent a health assessment (HA) at baseline, 18, 36 and 60 months and a GP record review (GPRR) at baseline, 36 and 60 months. Disability was measured via difficulty in 17 Activities of Daily Living. Trajectory identification was assessed by gender stratified, mortality adjusted, group-based trajectory modelling (GBTM) and the impact of life-course SES (level of education; occupational class; deprivation) on trajectory membership evaluated (adjusting for confounding variables). Results 851 participants agreed to HA and GPRR, 840 (98.7%) with complete disability data. Four distinct trajectories were evident for both sexes. A disability-free trajectory between age 85 and 90 was identified in men only (9% of the sample). The most disabled trajectories had severe disability at age 85 progressing to profound disability by age 90. After adjusting for confounders education remained significant; men and women with most education being less likely to be in the most disabled trajectory (Men: OR = 0.80, 95% CI 0.65–0.98; women: OR = 0.59, 95% CI 0.42–0.83). Conclusion Distinct disability trajectories are evident in the very old and these are influenced by education, suggesting SES disadvantages cumulate throughout the life-course to create health and mortality inequalities later. PMID:25747850

  3. Dynamics and Kinetics Study of "In-Water" Chemical Reactions by Enhanced Sampling of Reactive Trajectories.

    Science.gov (United States)

    Zhang, Jun; Yang, Y Isaac; Yang, Lijiang; Gao, Yi Qin

    2015-11-12

    High potential energy barriers and engagement of solvent coordinates set challenges for in silico studies of chemical reactions, and one is quite commonly limited to study reactions along predefined reaction coordinate(s). A systematic protocol, QM/MM MD simulations using enhanced sampling of reactive trajectories (ESoRT), is established to quantitatively study chemical transitions in complex systems. A number of trajectories for Claisen rearrangement in water and toluene were collected and analyzed, respectively. Evidence was found that the bond making and breaking during this reaction are concerted processes in solutions, preferentially through a chairlike configuration. Water plays an important dynamic role that helps stabilize the transition sate, and the dipole-dipole interaction between water and the solute also lowers the transition barrier. The calculated rate coefficient is consistent with the experimental measurement. Compared with water, the reaction pathway in toluene is "narrower" and the reaction rate is slower by almost three orders of magnitude due to the absence of proper interactions to stabilize the transition state. This study suggests that the "in-water" nature of the Claisen rearrangement in aqueous solution influences its thermodynamics, kinetics, as well as dynamics.

  4. Outcomes of childhood conduct problem trajectories in early adulthood: findings from the ALSPAC study.

    Science.gov (United States)

    Kretschmer, Tina; Hickman, Matthew; Doerner, Rita; Emond, Alan; Lewis, Glyn; Macleod, John; Maughan, Barbara; Munafò, Marcus R; Heron, Jon

    2014-07-01

    Although conduct problems in childhood are stably associated with problem outcomes, not every child who presents with conduct problems is at risk. This study extends previous studies by testing whether childhood conduct problem trajectories are predictive of a wide range of other health and behavior problems in early adulthood using a general population sample. Based on 7,218 individuals from the Avon longitudinal study of parents and children, a three-step approach was used to model childhood conduct problem development and identify differences in early adult health and behavior problems. Childhood conduct problems were assessed on six occasions between age 4 and 13 and health and behavior outcomes were measured at age 18. Individuals who displayed early-onset persistent conduct problems throughout childhood were at greater risk for almost all forms of later problems. Individuals on the adolescent-onset conduct problem path consumed more tobacco and illegal drugs and engaged more often in risky sexual behavior than individuals without childhood conduct problems. Levels of health and behavior problems for individuals on the childhood-limited path were in between those for stable low and stable high trajectories. Childhood conduct problems are pervasive and substantially affect adjustment in early adulthood both in at-risk samples as shown in previous studies, but also in a general population sample. Knowing a child's developmental course can help to evaluate the risk for later maladjustment and be indicative of the need for early intervention.

  5. Palliative care needs at different phases in the illness trajectory: a survey study in patients with cancer.

    Science.gov (United States)

    Beernaert, K; Pardon, K; Van den Block, L; Devroey, D; De Laat, M; Geboes, K; Surmont, V; Deliens, L; Cohen, J

    2016-07-01

    Despite the growing consensus on the benefits of initiating palliative care early in the disease trajectory, it remains unclear at what point palliative care needs emerge. This study investigates quality of life and unmet palliative care needs at three phases in the cancer trajectory, curative, life-prolonging and most advanced (prognosis care needs within the domains of palliative care. We used European reference values of the EORTC QLQ-C30 to compare the mean scores with a norm group. The groups further on in the cancer trajectory reported statistically and clinically poorer functioning compared with earlier phases, also when controlled for the effects of sex, age or type of cancer. Higher symptom burdens for fatigue, pain, dyspnoea and appetite loss were found in groups further into the trajectory, p care needs of patients from diagnosis onwards.

  6. Developmental Trajectories of Disordered Eating from Early Adolescence to Young Adulthood: A Longitudinal Study

    Science.gov (United States)

    Slane, Jennifer D.; Klump, Kelly L.; McGue, Matthew; Iacono, William G.

    2014-01-01

    Objective Research examining changes in eating disorder symptoms across adolescence suggests an increase in disordered eating from early to late adolescence. However, relevant studies have largely been cross-sectional in nature and most have not examined the changes in the attitudinal symptoms of eating disorders (e.g., weight concerns). This longitudinal study aimed to address gaps in the available data by examining the developmental trajectories of disordered eating in females from preadolescence into young adulthood. Method Participants were 745 same-sex female twins from the Minnesota Twin Family Study. Disordered eating was assessed using the Total Score, Body Dissatisfaction subscale, Weight Preoccupation subscale, and a combined Binge Eating and Compensatory Behavior subscale from the Minnesota Eating Behavior Survey assessed at the ages of 11, 14, 18, 21, and 25. Several latent growth models were fit to the data to identify the trajectory that most accurately captures the changes in disordered eating symptoms from 11 to 25 years. Results The best-fitting models for overall levels of disordered eating, body dissatisfaction, and weight preoccupation showed an increase in from 11 through 25 years. In contrast, bulimic behaviors increased to age of 18 and then stabilized to age of 25. Discussion The findings expanded upon extant research by investigating longitudinal, symptom specific, within-person changes and showing an increase in cognitive symptoms into young adulthood and the stability of disordered eating behaviors past late adolescence. PMID:24995824

  7. MUSIC EDUCATION AND TASTE FORMING OF CLASSICAL MUSIC STYLE: CASE STUDY IN CULTURAL INSTITUTIONKARTA PUSTAKA YOGYAKARTA INDONESIA

    Directory of Open Access Journals (Sweden)

    Inggit Sitowati

    2014-06-01

    Full Text Available Karta Pustaka is one of the cultural institutions in Yogyakarta, which has a classical music concert program. The purpose of this study is to describe the history of Karta Pustaka and organizing classical music concerts, the concert format, and its role in supporting classical music education in Yogyakarta. The method used in this study is qualitative research with historical and musicological approach.The data are collected by using interviews, documents and observations. Data were analyzed using qualitative descriptions technicians. The results showed that Karta Pustaka as cultural institution has become a classical musicmedia which has a supporting role in classical music education in Yogyakarta. The classical music concert program and classical music workshop held by Karta Pustaka information and knowledge for the students and people of musical art in Yogyakarta. In addition Karta Pustaka also acts as a forming media and the development of consumer’s classical music tastes and styles in Yogyakarta.

  8. Comparison of Bayesian and Classical Analysis of Weibull Regression Model: A Simulation Study

    Directory of Open Access Journals (Sweden)

    İmran KURT ÖMÜRLÜ

    2011-01-01

    Full Text Available Objective: The purpose of this study was to compare performances of classical Weibull Regression Model (WRM and Bayesian-WRM under varying conditions using Monte Carlo simulations. Material and Methods: It was simulated the generated data by running for each of classical WRM and Bayesian-WRM under varying informative priors and sample sizes using our simulation algorithm. In simulation studies, n=50, 100 and 250 were for sample sizes, and informative prior values using a normal prior distribution with was selected for b1. For each situation, 1000 simulations were performed. Results: Bayesian-WRM with proper informative prior showed a good performance with too little bias. It was found out that bias of Bayesian-WRM increased while priors were becoming distant from reliability in all sample sizes. Furthermore, Bayesian-WRM obtained predictions with more little standard error than the classical WRM in both of small and big samples in the light of proper priors. Conclusion: In this simulation study, Bayesian-WRM showed better performance than classical method, when subjective data analysis performed by considering of expert opinions and historical knowledge about parameters. Consequently, Bayesian-WRM should be preferred in existence of reliable informative priors, in the contrast cases, classical WRM should be preferred.

  9. Childhood Anxiety Trajectories and Adolescent Disordered Eating: Findings from the NICHD Study of Early Child Care and Youth Development

    Science.gov (United States)

    Zerwas, Stephanie; Von Holle, Ann; Watson, Hunna; Gottfredson, Nisha; Bulik, Cynthia M.

    2015-01-01

    Objective The goal of the present paper was to examine whether childhood anxiety trajectories predict eating psychopathology. We predicted that girls with trajectories of increasing anxiety across childhood would have significantly greater risk of disordered eating in adolescence in comparison to girls with stable or decreasing trajectories of anxiety over childhood. Method Data were collected as part of the prospective longitudinal NICHD Study of Early Child Care and Youth Development (N=450 girls). Childhood anxiety was assessed yearly (54 months through 6th grade) via maternal report on the Child Behavior Checklist. Disordered eating behaviors were assessed at age 15 via adolescent self-report on the Eating Attitudes Test (EAT-26). We conducted latent growth mixture modeling to define girls’ childhood anxiety trajectories. Maternal sensitivity, maternal postpartum depression, maternal anxiety, and child temperament were included as predictors of trajectory membership. Results The best fitting model included three trajectories of childhood anxiety, the low-decreasing class (22.9% of girls), the high-increasing class (35.4%), and the high-decreasing class (41.6%). Mothers with more symptoms of depression and separation anxiety had girls who were significantly more likely to belong to the high-increasing anxiety trajectory. There were no significant differences in adolescent disordered eating for girls across the three childhood anxiety trajectories. Conclusions Childhood anxiety, as captured by maternal report, may not be the most robust predictor of adolescent disordered eating and may be of limited utility for prevention programs that aim to identify children in the community at greatest risk for disordered eating. PMID:24938214

  10. Modeling cognitive trajectories within longitudinal studies: a focus on older adults.

    Science.gov (United States)

    Steinerman, Joshua R; Hall, Charles B; Sliwinski, Martin J; Lipton, Richard B

    2010-10-01

    The natural history of life span cognitive performance and its late-life determinants have been studied from an array of perspectives. Significant insights come from psychological disciplines, including cognitive, developmental, and neuropsychology, as well as from medical specialties, such as geriatrics, neurology, psychiatry, neuroradiology, and neuropathology, that contribute to the growing interdisciplinary scientific field: cognitive neuroscience of aging. This survey of longitudinal studies of aging suggests that disease-oriented investigations commonly do not adequately consider normative cognitive changes, whereas developmental studies do not sufficiently measure and model nonnormative cognitive aging. This article argues for an integrative perspective that considers both of these influences on cognitive trajectories and presents a series of methodological concerns that have not been addressed comprehensively. Interdisciplinary methods from longitudinal observational studies should be leveraged to enable translational interventions to promote brain longevity.

  11. [Trajectories of aging in a sample of elderly people: a longitudinal study].

    Science.gov (United States)

    Navarro-González, Elena; Calero, María Dolores; Becerra-Reina, Dolores

    2015-01-01

    The present study analyzes variables associated with different trajectories of aging, and the level of cognitive functioning in a sample of older adults. Although this work is part of a broader investigation where initially 141 people were assessed, this paper only discusses the cognitive functioning and cognitive development of 64 older people who have been followed up four years after the initial assessment, with a mean age of 83.84 years (age range 65 to 99 years). In the initial assessment all the participants were assessed with a psychological battery that included the MEC, the verbal fluency task FVS, a sustained attention task, a working memory test, a Quality of Life Questionnaire, a scale of dependency, and the AVLT-Learning Potential test. In the follow up assessment, participants have been assessed with the MEC, the verbal fluency task FVS, and the verbal memory test AVLT-PA. the results show relatively stable trajectories of aging and that the variables that better predict cognitive evolution of the elderly are working memory and post-test score in the AVLT-LP. Despite the time lapse between the two assessments and the age of the participants, older adults have remained relatively stable in their cognitive functioning, which in part contradicts the idea that--especially after 80 years--a general decline of cognitive functioning occurs in old age. Copyright © 2014 SEGG. Published by Elsevier Espana. All rights reserved.

  12. A Study on the Present Situation of Ethnic Classics Translation in China

    Institute of Scientific and Technical Information of China (English)

    王婧

    2016-01-01

    Because of language barriers, Chinese minority literary classics fail to obtain its corresponding attention and aspect. The present situation of translation is not optimistic. Under the background of multi-culture, the study of minority language and literary translation has great significance to promote the communication between all ethnic groups and between Chinese and foreign culture. Through the discussion of the meaning of minority language translation, the present situation research, countermeasures and relevant policies, the thesis calls on both researchers and translators to study and research the national minority literary classics in future and carry forward national literature and culture.

  13. Comparative Study of laryngeal mask airway Supreme and laryngeal mask airway Classic in paralyzed patients

    OpenAIRE

    2016-01-01

    Aim and Objectives: The present study was undertaken to compare the LMA Classic with LMA Supreme in assessing the ease of insertion, number of attempts, time for insertion, any unwanted responses, stability of device, peak airway pressure, leak volume and leak fraction and postoperative complications.Methods: A total of 274 patients of ASA grade 1 and 2 were included in the study and divided into two groups with 137 patients in each group: the LMA Classic group (group C) and LMA Supreme group...

  14. A Classical Delphi Study to Identify the Barriers of Pursuing Green Information and Communication Technologies

    Science.gov (United States)

    Gotay, Jose Antonio

    2013-01-01

    This qualitative, classical Delphi study served to explore the apparent lack of corporate commitment to prioritized Green Information Communication Technologies (ICTs), which could delay the economic and social benefits for maximizing the use of natural energy resources in a weak economy. The purpose of this study was to examine the leadership…

  15. Application of Hamilton's Principle to the Study of the Anharmonic Oscillator in Classical Mechanics.

    Science.gov (United States)

    And Others; Gilmartin, Harvey

    1979-01-01

    Presented is a form of Hamilton's principle for classical mechanics appropriate to the study of arbitrary self-sustained vibrations in one dimension. It is applied as an approximate computational tool to the study of several examples of anharmonic oscillation. (Author/GA)

  16. A Classical Delphi Study to Identify the Barriers of Pursuing Green Information and Communication Technologies

    Science.gov (United States)

    Gotay, Jose Antonio

    2013-01-01

    This qualitative, classical Delphi study served to explore the apparent lack of corporate commitment to prioritized Green Information Communication Technologies (ICTs), which could delay the economic and social benefits for maximizing the use of natural energy resources in a weak economy. The purpose of this study was to examine the leadership…

  17. Studies on the s_dm.t=f verb form in Classical Egyptian

    NARCIS (Netherlands)

    Zonhoven, Ludovicus Martinus Johannes

    1997-01-01

    This study is devoted to some synchronic aspects of the sDm.t=f verb form, primarily its meaning and uses in Classical Egyptian. In the introduction some attention is paid to the history of the studies of the form and its origin, an aspect which will receive no further consideration. In accordance

  18. Studies on the s_dm.t=f verb form in Classical Egyptian

    NARCIS (Netherlands)

    Zonhoven, Ludovicus Martinus Johannes

    1997-01-01

    This study is devoted to some synchronic aspects of the sDm.t=f verb form, primarily its meaning and uses in Classical Egyptian. In the introduction some attention is paid to the history of the studies of the form and its origin, an aspect which will receive no further consideration. In accordance w

  19. Studies on the s_dm.t=f verb form in Classical Egyptian

    NARCIS (Netherlands)

    Zonhoven, Ludovicus Martinus Johannes

    1997-01-01

    This study is devoted to some synchronic aspects of the sDm.t=f verb form, primarily its meaning and uses in Classical Egyptian. In the introduction some attention is paid to the history of the studies of the form and its origin, an aspect which will receive no further consideration. In accordance w

  20. Trajectory attractors of equations of mathematical physics

    Energy Technology Data Exchange (ETDEWEB)

    Vishik, Marko I; Chepyzhov, Vladimir V [Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow (Russian Federation)

    2011-08-31

    In this survey the method of trajectory dynamical systems and trajectory attractors is described, and is applied in the study of the limiting asymptotic behaviour of solutions of non-linear evolution equations. This method is especially useful in the study of dissipative equations of mathematical physics for which the corresponding Cauchy initial-value problem has a global (weak) solution with respect to the time but the uniqueness of this solution either has not been established or does not hold. An important example of such an equation is the 3D Navier-Stokes system in a bounded domain. In such a situation one cannot use directly the classical scheme of construction of a dynamical system in the phase space of initial conditions of the Cauchy problem of a given equation and find a global attractor of this dynamical system. Nevertheless, for such equations it is possible to construct a trajectory dynamical system and investigate a trajectory attractor of the corresponding translation semigroup. This universal method is applied for various types of equations arising in mathematical physics: for general dissipative reaction-diffusion systems, for the 3D Navier-Stokes system, for dissipative wave equations, for non-linear elliptic equations in cylindrical domains, and for other equations and systems. Special attention is given to using the method of trajectory attractors in approximation and perturbation problems arising in complicated models of mathematical physics. Bibliography: 96 titles.

  1. Greenspan, Vasey and Worthen : D.H. Lawrence: Studies in Classic American Literature

    Directory of Open Access Journals (Sweden)

    Neil ROBERTS

    2004-10-01

    Full Text Available This book is, among other things, a reminder of how large a part chance plays in the emergence of classic works of literature. The book that was eventually published as Studies in Classic American Literature in 1923 was the outcome of a longer period of  gestation and drafting than any book of Lawrence’s other than Women in Love—about seven years in all. For some of that time, at least, Lawrence considered it (or one of the forms that it passed through as his most important work after The Ra...

  2. A Classical Test Theory Analysis of the Light and Spectroscopy Concept Inventory National Study Data Set

    Science.gov (United States)

    Schlingman, Wayne M.; Prather, Edward E.; Wallace, Colin S.; Brissenden, Gina; Rudolph, Alexander L.

    2012-01-01

    This paper is the first in a series of investigations into the data from the recent national study using the Light and Spectroscopy Concept Inventory (LSCI). In this paper, we use classical test theory to form a framework of results that will be used to evaluate individual item difficulties, item discriminations, and the overall reliability of the…

  3. Gender-Specific Developmental Trajectories of Anxiety during Adolescence : Determinants and Outcomes. The TRAILS Study

    NARCIS (Netherlands)

    Legerstee, Jeroen S; Verhulst, Frank C; Robbers, Sylvana C C; Ormel, Johan; Oldehinkel, Albertine J; van Oort, Floor V A

    OBJECTIVE: To identify developmental trajectories of anxiety symptoms for adolescent girls and boys. Trajectories were compared with regard to early-adolescent risk factors and psychiatric outcomes during adolescence and in young adulthood. METHOD: A community sample of 2,230 adolescents was

  4. Effect of Helicobacter pylori infection on growth trajectories in young Ethiopian children: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Bineyam Taye

    2016-09-01

    Conclusions: These findings add to the growing body of evidence supporting that H. pylori infection is inversely associated with childhood growth trajectory, after controlling for a range of factors associated with reduced growth and H. pylori status. Further follow-up will be important to confirm possible catch-up in height trajectory among H. pylori-infected children as they grow older.

  5. Developmental trajectories of associative memory from childhood to adulthood: a behavioral and neuroimaging study.

    Science.gov (United States)

    Guillery-Girard, Bérengère; Martins, Sylvie; Deshayes, Sebastien; Hertz-Pannier, Lucie; Chiron, Catherine; Jambaqué, Isabelle; Landeau, Brigitte; Clochon, Patrice; Chételat, Gaël; Eustache, Francis

    2013-01-01

    Episodic memory refers to the capacity to bind multimodal memories to constitute a unique personal event. Most developmental studies on episodic memory focused on one specific component, i.e., the core factual information. The present study examines the relevance of a novel episodic paradigm to assess its developmental trajectories in a more comprehensive way according to the type of association (item-feature, item-location, and item-sequence associations) with measures of both objective and subjective recollection. We conducted a behavioral study aimed at testing the effects of age in a large sample of 160 children, adolescents, and young adults (6-23 years old). We confronted the behavioral data to the neural correlates in a subgroup of 30 children using voxel-based morphometry. Behavioral data outlined differential developmental trajectories according to the type of association, with a continuous increase of factual associative memory efficiency until 10 years, a linear increase of performance in spatial associative memory that pursues until early adulthood and an abrupt increase in temporal associative memory efficiency between 9 and 10. Regarding recollection, measures showed a more pronounced enhancement from 9 to 10 years. Hence, behavioral data highlight a peculiar period in late childhood (8-10 years old) crucial for the developmental time course of episodic memory. Regarding structural data, we found that the improvement of associative memory efficiency was related to a decrease in gray matter volume in a large cerebral network including the dorsolateral and ventrolateral prefrontal cortex (and superior and anterior temporal regions), and the hippocampus bilaterally. These data suggest that multimodal integration would probably be related to the maturation of temporal regions and modulated by a fronto-parietal network. Besides, our findings emphasize the relevance of the present paradigm to assess episodic memory especially in the clinical setting.

  6. Developmental trajectories of associative memory from childhood to adulthood: a behavioral and neuroimaging study

    Directory of Open Access Journals (Sweden)

    Berengere eGuillery-Girard

    2013-09-01

    Full Text Available Episodic memory refers to the capacity to bind multimodal memories to constitute a unique personal event. Most developmental studies on episodic memory focused on one specific component, i.e. the core factual information. The present study examines the relevance of a novel episodic paradigm to assess its developmental trajectories in a more comprehensive way according to the type of association (item-feature, item-location and item-sequence associations with measures of both objective and subjective recollection. We conducted a behavioral study aimed at testing the effects of age in a large sample of 160 children, adolescents and young adults (6 to 23 years old. We confronted the behavioral data to the neural correlates in a subgroup of 30 children using voxel-based morphometry. Behavioral data outlined differential developmental trajectories according to the type of association, with a continuous increase of factual associative memory efficiency until 10 years, a linear increase of performance in spatial associative memory that pursues until early adulthood and an abrupt increase in temporal associative memory efficiency between 9 and 10. Regarding recollection, measures showed a more pronounced enhancement from 9 to 10 years. Hence, behavioral data highlight a peculiar period in late childhood (8 to 10 years old crucial for the developmental time course of episodic memory. Regarding structural data, we found that the improvement of associative memory efficiency was related to a decrease in gray matter volume in a large cerebral network including the dorsolateral and ventrolateral prefrontal cortex (and superior and anterior temporal regions and the hippocampus bilaterally. These data suggest that multimodal integration would probably be related to the maturation of temporal regions and modulated by a fronto-parietal network. Besides, our findings emphasize the relevance of the present paradigm to assess episodic memory especially in the

  7. Anxiety trajectories and identity development in adolescence: a five-wave longitudinal study.

    Science.gov (United States)

    Crocetti, Elisabetta; Klimstra, Theo; Keijsers, Loes; Hale, William W; Meeus, Wim

    2009-07-01

    The aim of this five-wave longitudinal study was to investigate the relationship between anxiety and adolescent identity development. Participants were 1,313 adolescents who annually completed measures of anxiety and identity. Growth Mixture Modeling (GMM) analyses demonstrated that the adolescent population was best typified by two latent growth trajectory classes: a low anxiety class (n = 1,199) characterized by a low initial level of anxiety that decreased over time and a high anxiety class (n = 114) characterized by a higher initial level of anxiety that increased over time. To answer our research question, we tested a model in which the anxiety classes predicted initial levels and rates of change of three identity dimensions: commitment, in-depth exploration, and reconsideration of commitment. Findings indicated that the high anxiety adolescents displayed a more troublesome identity development than their low anxiety peers, since their commitments became weaker with age, and they reconsidered them intensively.

  8. Parenting and Trajectories of Children’s Maladaptive Behaviors: A 12-year Prospective Community Study

    Science.gov (United States)

    Luyckx, Koen; Tildesley, Elizabeth A.; Soenens, Bart; Andrews, Judy A.; Hampson, Sarah E.; Peterson, Missy; Duriez, Bart

    2011-01-01

    This study investigated how parenting accounted for inter-individual differences in developmental trajectories of different child behaviors across childhood and adolescence. In a cohort sequential community sample of 1,049 children, latent class growth analysis was applied to three parent-reported dimensions (monitoring, positive parenting, inconsistent discipline) across 12 annual assessments (ages 6–18). Four longitudinal parenting styles (authoritative, authoritarian, indulgent, uninvolved) were differentiated on the basis of levels and rates of change in the constituent parenting dimensions. Multi-group analyses demonstrated that these parenting styles were differentially related to changes in parent- and child-reported measures of children’s alcohol and cigarette use, antisocial behavior, and internalizing symptoms, with the authoritative parenting class being related to the most optimal long-term development. Practical implications and future research suggestions are discussed. PMID:21534057

  9. Regression, developmental trajectory and associated problems in disorders in the autism spectrum: the SNAP study.

    Science.gov (United States)

    Baird, Gillian; Charman, Tony; Pickles, Andrew; Chandler, Susie; Loucas, Tom; Meldrum, David; Carcani-Rathwell, Iris; Serkana, Devanitha; Simonoff, Emily

    2008-11-01

    We report rates of regression and associated findings in a population derived group of 255 children aged 9-14 years, participating in a prevalence study of autism spectrum disorders (ASD); 53 with narrowly defined autism, 105 with broader ASD and 97 with non-ASD neurodevelopmental problems, drawn from those with special educational needs within a population of 56,946 children. Language regression was reported in 30% with narrowly defined autism, 8% with broader ASD and less than 3% with developmental problems without ASD. A smaller group of children were identified who underwent a less clear setback. Regression was associated with higher rates of autistic symptoms and a deviation in developmental trajectory. Regression was not associated with epilepsy or gastrointestinal problems.

  10. Cultural Orientation Trajectories and Substance Use: Findings From a Longitudinal Study of Mexican-Origin Youth.

    Science.gov (United States)

    Cruz, Rick A; King, Kevin M; Cauce, Ana M; Conger, Rand D; Robins, Richard W

    2017-03-01

    Cultural adaptation may influence Latino youth substance use (SU) development, yet few longitudinal studies have examined cultural change over time and adolescent SU outcomes. Using longitudinal data collected annually across ages 10-16 from 674 Mexican-origin youth (50% female), the authors characterized cultural adaptation patterns for language use (English and Spanish use), values (American values and familism values), and identity (ethnic pride), and examined whether these cultural adaptation patterns were associated with differential SU risk. Youth with increasing bilingualism and high/stable family values had lower SU risk compared to youth who primarily spoke English and endorsed decreasing family values, respectively. Ethnic pride trajectories were not associated with SU. Findings highlight the importance of considering cultural change related to Latino youth SU.

  11. Determining leaf trajectories for dynamic multileaf collimators with consideration of marker visibility: an algorithm study.

    Science.gov (United States)

    Zhao, Bo; Dai, Jianrong

    2014-09-01

    The purpose of this study was to develop a leaf-setting algorithm for Dynamic Multileaf Collimator-Intensity-Modulated Radiation Therapy (DMLC-IMRT) for optimal marker visibility. Here, a leaf-setting algorithm (called a Delta algorithm) was developed with the objective of maximizing marker visibility so as to improve the tracking effectiveness of fiducial markers during treatment delivery. The initial leaf trajectories were generated using a typical leaf-setting algorithm, then the leaf trajectories were adjusted by Delta algorithm operations (analytical computations and a series of matrix calculations) to achieve the optimal solution. The performance of the Delta algorithm was evaluated with six test fields (with randomly generated intensity profiles) and 15 clinical fields from IMRT plans of three prostate cancer patients. Compared with the initial solution, the Delta algorithm kept the total delivered intensities (TDIs) constant (without increasing the beam delivery time), but improved marker visibility (the percentage ratio of marker visibility time to beam delivery time). For the artificial fields (with three markers), marker visibility increased from 68.00-72.00% for a small field (5 × 5), from 38.46-43.59% for a medium field (10 × 10), and from 28.57-37.14% for a large field (20 × 20). For the 15 clinical fields, marker visibility increased 6-30% for eight fields and > 50% for two fields but did not change for five fields. A Delta algorithm was proposed to maximize marker visibility for DMLC-IMRT without increasing beam delivery time, and this will provide theoretical fundamentals for future studies of 4D DMLC tracking radiotherapy. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  12. TRAJECTORIES OF DEPRESSIVE EPISODES AND HYPERTENSION OVER 24 YEARS: THE WHITEHALL II PROSPECTIVE COHORT STUDY

    Science.gov (United States)

    Nabi, Hermann; Chastang, Jean-François; Lefèvre, Thomas; Dugravot, Aline; Melchior, Maria; Marmot, Michael G.; Shipley, Martin J.; Kivimäki, Mika; Singh-Manoux, Archana

    2011-01-01

    Prospective data on depressive symptoms and blood pressure (BP) are scarce, and the impact of age on this association is poorly understood. The present study examines longitudinal trajectories of depressive episodes and the probability of hypertension associated with these trajectories over time. Participants were 6,889 men and 3,413 women London based civil servants, aged 35–55 years at baseline, followed for 24 years between 1985 and 2009. Depressive episode (defined as scoring 4 or more on the General Health Questionnaire-Depression subscale or using prescribed antidepressant medication) and hypertension (systolic/diastolic blood pressure ≥ 140/90 mm Hg or use of antihypertensive medication) were assessed concurrently at five medical examinations. In the fully adjusted longitudinal logistic regression analyses based on Generalized-Estimating-Equations using age as the time scale, participants in the “increasing depression” group had a 24% (p<0.05) lower risk of hypertension at ages 35–39, compared to those in the “low/transient depression” group. However, there was a faster age-related increase in hypertension in the “increasing depression” group, corresponding to a 7% (p<0.01) greater increase in the odds of hypertension for every each five-year increase in age. A higher risk of hypertension in the first group of participants was not evident before age 55. A similar pattern of association was observed in men and women although it was stronger in men. This study suggests that the risk of hypertension increases with repeated experience of depressive episodes over time and becomes evident in later adulthood. PMID:21339474

  13. Aircraft Trajectory Optimization Using Parametric Optimization Theory

    OpenAIRE

    Valenzuela Romero, Alfonso

    2012-01-01

    In this thesis, a study of the optimization of aircraft trajectories using parametric optimization theory is presented. To that end, an approach based on the use of predefined trajectory patterns and parametric optimization is proposed. The trajectory pat

  14. Chaos And Quantum-classical Correspondence For Two- Coupled Spins

    CERN Document Server

    Emerson, J V

    2001-01-01

    Two approaches to quantum-classical correspondence are distinguished according to the classical dynamical theory with which quantum theory is compared. The first of these, Ehrenfest correspondence, defines a dynamical regime in which the quantum expectation values follow approximately a classical trajectory. The second of these, Liouville correspondence, applies when the quantum probability distributions remain well approximated by a density in the classical phase space. The former applies only for narrow states, whereas the latter may remain valid even for quantum states that have spread to the system size. A spin model is adopted for this correspondence study because the quantum state is discrete and finite- dimensional, and thus no artificial truncation of the Hilbert space is required. The quantum time-evolution is given by a discrete unitary mapping. The corresponding classical model is volume-preserving (non-dissipative) and the time-evolution is given by a symplectic map. In classically chaotic regimes...

  15. Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study

    National Research Council Canada - National Science Library

    van Maanen A; Meijer AM; Smits MG; Oort FJ

    2017-01-01

    .... In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention...

  16. Rovibrational dynamics of the RbCs molecule in static electric fields. Classical study

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, Pedro F.; Iñarrea, Manuel [Área de Física, Universidad de la Rioja, E-26006 Logroño (Spain); Salas, J. Pablo, E-mail: josepablo.salas@unirioja.es [Área de Física, Universidad de la Rioja, E-26006 Logroño (Spain)

    2012-04-02

    We study the classical dynamics of the RbCs molecule in the presence of a static electric field. Under the Born–Oppenheimer approximation, we perform a rovibrational investigation which includes the interaction of the field with the molecular polarizability. The stability of the equilibrium points and the phase space structure of the system are explored in detail. We find that, for strong electric fields or for energies close to the dissociation threshold, the molecular polarizability causes relevant effects on the system dynamics. -- Highlights: ► We study the classical rovibrational dynamics of the alkali polar dimer RbCs. ► In the model we consider the interaction of the field with the molecular polarizability. ► The potential energy surface is studied depending on the electric field strength. ► Using surfaces of section we study the phase space structure. ► We find that the molecular polarizability causes relevant effects on the system dynamics.

  17. Trajectories of Mental Health over 16 Years amongst Young Adult Women: The Australian Longitudinal Study on Women's Health

    Science.gov (United States)

    Holden, Libby; Ware, Robert S.; Lee, Christina

    2016-01-01

    This article used data from 5,171 young women participating in the Australian Longitudinal Study on Women's Health, a nationally representative longitudinal cohort study, to identify longitudinal trajectory patterns of mental health across 6 surveys over 16 years of early adulthood, from age 18-23 to age 34-39. In addition, we identified both…

  18. Effects of Pilates and Classical Kinesiotherapy on chronic low back pain: a case study

    OpenAIRE

    Ribeiro,Ivanna Avila; Oliveira,Tiago Damé de; Blois,Cleci Redin

    2015-01-01

    Abstract Introduction : Chronic low back pain (LBP) is characterized by daily lower back pain lasting more than three consecutive months. It may lead to functional disability and can be treated by several physical therapy techniques, including therapeutic exercise. The aim of this study was to investigate the effects of pilates and classical kinesiotherapy on the treatment of pain and functional disability in patients with chronic low back pain. Materials and methods : The study sample cons...

  19. A comperative study to ınvestigate teaching processes of baglama and classical guitar

    Directory of Open Access Journals (Sweden)

    Zekeriya Kaptan

    2010-01-01

    Full Text Available In this study, teaching processes of bağlama (a long-necked Turkish luteand classical guitar are investigated to be comparativly. The study aims to answer the following questions: How has the teaching process of these instruments proceed in our country? What are the teaching strategies of this instrument? What differences and similarities between the teaching process of these two in instruments? This is a qualitative research. The opinions of experts by using the interview technique was taken. Also, related literature were examined comprehensivly. The data that obtained from research were evaluated by applying methods of descriptive analysis. The results indicate that teaching processes of bağlama and classical guitar have some differences in our country and each instruments has their own theaching styles

  20. A comperative study to ınvestigate teaching processes of baglama and classical guitar

    Directory of Open Access Journals (Sweden)

    Zekeriya Kaptan

    2010-01-01

    Full Text Available In this study,  teaching processes of  bağlama (a long-necked Turkish luteand classical guitar are investigated to be comparativly. The study aims to answer the following questions: How has the teaching process of these instruments proceed in our country? What are the teaching strategies of this instrument?  What differences and similarities between the teaching process of these two in instruments? This is a qualitative research. The opinions of experts by using the interview technique was taken. Also, related literature were examined comprehensivly. The data that obtained from research were evaluated by applying methods of descriptive analysis. The results indicate that teaching processes of bağlama and classical guitar have some differences in our country and each instruments has their own theaching styles

  1. Dissipative quantum trajectories in complex space: Damped harmonic oscillator

    Science.gov (United States)

    Chou, Chia-Chun

    2016-10-01

    Dissipative quantum trajectories in complex space are investigated in the framework of the logarithmic nonlinear Schrödinger equation. The logarithmic nonlinear Schrödinger equation provides a phenomenological description for dissipative quantum systems. Substituting the wave function expressed in terms of the complex action into the complex-extended logarithmic nonlinear Schrödinger equation, we derive the complex quantum Hamilton-Jacobi equation including the dissipative potential. It is shown that dissipative quantum trajectories satisfy a quantum Newtonian equation of motion in complex space with a friction force. Exact dissipative complex quantum trajectories are analyzed for the wave and solitonlike solutions to the logarithmic nonlinear Schrödinger equation for the damped harmonic oscillator. These trajectories converge to the equilibrium position as time evolves. It is indicated that dissipative complex quantum trajectories for the wave and solitonlike solutions are identical to dissipative complex classical trajectories for the damped harmonic oscillator. This study develops a theoretical framework for dissipative quantum trajectories in complex space.

  2. Critical properties of the classical Heisenberg and XY models : A mean field renormalization group study

    Directory of Open Access Journals (Sweden)

    A. Sadeghi

    2007-03-01

    Full Text Available  Using both mean field renormalization group (MFRG and Surface-Bulk MFRG (SBMFRG, we study the critical behavior of the classical Heisenberg and XY models on a simple cubic lattice. Critical temperatures as well as critical exponents, characteristic the universality classes of these two models were calculated, analytically for1, 2, 3 and 4 spin clusters. The results are in good agreement with higher accurate methods such as Monte Carlo and High- temperature series.

  3. Girls' Tobacco and Alcohol Use during Early Adolescence: Prediction from Trajectories of Depressive Symptoms across Two Studies

    Science.gov (United States)

    Leve, Leslie D.; Harold, Gordon T.; Van Ryzin, Mark J.; Elam, Kit; Chamberlain, Patricia

    2012-01-01

    Associations between trajectories of depressive symptoms and subsequent tobacco and alcohol use were examined in two samples of girls assessed at age 11.5 (T1), 12.5 (T2), and 13.5 (T3). Two samples were examined to ascertain if there was generalizability of processes across risk levels and cultures. Study 1 comprised a United States-based sample…

  4. Adding Learning Resources: A Study of Two Toddlers' Modes and Trajectories of Participation in Early Childhood Education

    Science.gov (United States)

    Kultti, Anne

    2015-01-01

    This study focuses on the nature of children's participation in an Australian early childhood context in which their second language is used. The aim is to create knowledge of toddlers' modes and trajectories of participation. Empirical data documenting the participation of two toddlers were gathered through video observations of everyday…

  5. Trajectories and Determinants of Alcohol Use among LGB Young Adults and Their Heterosexual Peers: Results from a Prospective Study

    Science.gov (United States)

    Hatzenbuehler, Mark L.; Corbin, William R.; Fromme, Kim

    2008-01-01

    Lesbians, gays, and bisexuals (LGBs) are at increased risk for alcohol use during young adulthood, but the mechanisms remain inadequately understood. The aim of the present study was to examine the trajectories and determinants of alcohol use among LGB young adults who were sampled prospectively. The sample included 111 LGB individuals (47 women…

  6. Age-related brain trajectories in schizophrenia: a systematic review of structural MRI studies.

    Science.gov (United States)

    Chiapponi, Chiara; Piras, Fabrizio; Fagioli, Sabrina; Piras, Federica; Caltagirone, Carlo; Spalletta, Gianfranco

    2013-11-30

    Using the Pubmed database, we performed a detailed literature search for structural magnetic resonance imaging studies on patients with schizophrenia, investigating the relationship between macroscopic and microscopic structural parameters and age, to delineate an age-related trajectory. Twenty-six studies were considered for the review, from January 2000 to June 2012. Research results are heterogeneous because of the multifactorial features of schizophrenia and the multiplicity of the methodological approaches adopted. Some areas, within the amygdala-hippocampus complex, which are affected early in life by schizophrenia, age in a physiological way. Other regions, such as the superior temporal gyrus, appear already impaired at the onset of symptoms, undergo a worsening in the acute phase but later stabilize, progressing physiologically over years. Finally, there are regions, such as the uncinate fasciculus, which are not altered early in life, but are affected around the onset of schizophrenia, with their impairment continuously worsening over time. Further extensive longitudinal studies are needed to understand the timing and the possible degenerative characteristics of structural impairment associated with schizophrenia.

  7. A study on a robot arm driven by three-dimensional trajectories predicted from non-invasive neural signals.

    Science.gov (United States)

    Kim, Yoon Jae; Park, Sung Woo; Yeom, Hong Gi; Bang, Moon Suk; Kim, June Sic; Chung, Chun Kee; Kim, Sungwan

    2015-08-20

    A brain-machine interface (BMI) should be able to help people with disabilities by replacing their lost motor functions. To replace lost functions, robot arms have been developed that are controlled by invasive neural signals. Although invasive neural signals have a high spatial resolution, non-invasive neural signals are valuable because they provide an interface without surgery. Thus, various researchers have developed robot arms driven by non-invasive neural signals. However, robot arm control based on the imagined trajectory of a human hand can be more intuitive for patients. In this study, therefore, an integrated robot arm-gripper system (IRAGS) that is driven by three-dimensional (3D) hand trajectories predicted from non-invasive neural signals was developed and verified. The IRAGS was developed by integrating a six-degree of freedom robot arm and adaptive robot gripper. The system was used to perform reaching and grasping motions for verification. The non-invasive neural signals, magnetoencephalography (MEG) and electroencephalography (EEG), were obtained to control the system. The 3D trajectories were predicted by multiple linear regressions. A target sphere was placed at the terminal point of the real trajectories, and the system was commanded to grasp the target at the terminal point of the predicted trajectories. The average correlation coefficient between the predicted and real trajectories in the MEG case was [Formula: see text] ([Formula: see text]). In the EEG case, it was [Formula: see text] ([Formula: see text]). The success rates in grasping the target plastic sphere were 18.75 and 7.50 % with MEG and EEG, respectively. The success rates of touching the target were 52.50 and 58.75 % respectively. A robot arm driven by 3D trajectories predicted from non-invasive neural signals was implemented, and reaching and grasping motions were performed. In most cases, the robot closely approached the target, but the success rate was not very high because

  8. On the classical limit of Bohmian mechanics for Hagedorn wave packets

    CERN Document Server

    Dürr, Detlef

    2010-01-01

    We consider the classical limit of quantum mechanics in terms of Bohmian trajectories. For wave packets as defined by Hagedorn we show that the Bohmian trajectories converge to Newtonian trajectories in probability.

  9. Numerical study of chiral plasma instability within the classical statistical field theory approach

    CERN Document Server

    Buividovich, P V

    2015-01-01

    We report on a numerical study of the real-time dynamics of chirally imbalanced lattice Dirac fermions coupled to dynamical electromagnetic field. To this end we use the classical statistical field theory approach, in which the quantum evolution of fermions is simulated exactly, and electromagnetic fields are treated as classical. Motivated by recent experiments on chirally imbalanced Dirac semimetals, we use the Wilson-Dirac lattice Hamiltonian for fermions in order to model the emergent nature of chiral symmetry at low energies. In general, we observe that the backreaction of fermions on the electromagnetic field prevents the system from acquiring large chirality imbalance. In the case of chirality pumping in parallel electric and magnetic fields, electric field is screened by the produced on-shell fermions and the accumulation of chirality is hence stopped. In the case of evolution with initially present chirality imbalance, axial charge tends to decay at the expense of nonzero helicity of electromagnetic ...

  10. Coronene molecules in helium clusters: Quantum and classical studies of energies and configurations

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Cantano, Rocío; Pérez de Tudela, Ricardo; Bartolomei, Massimiliano; Hernández, Marta I.; Campos-Martínez, José; González-Lezana, Tomás, E-mail: t.gonzalez.lezana@csic.es; Villarreal, Pablo [Instituto de Física Fundamental, IFF-CSIC, Serrano 123, 28006 Madrid (Spain); Hernández-Rojas, Javier; Bretón, José [Departamento de Física and IUdEA, Universidad de La Laguna, 38205 Tenerife (Spain)

    2015-12-14

    Coronene-doped helium clusters have been studied by means of classical and quantum mechanical (QM) methods using a recently developed He–C{sub 24}H{sub 12} global potential based on the use of optimized atom-bond improved Lennard-Jones functions. Equilibrium energies and geometries at global and local minima for systems with up to 69 He atoms were calculated by means of an evolutive algorithm and a basin-hopping approach and compared with results from path integral Monte Carlo (PIMC) calculations at 2 K. A detailed analysis performed for the smallest sizes shows that the precise localization of the He atoms forming the first solvation layer over the molecular substrate is affected by differences between relative potential minima. The comparison of the PIMC results with the predictions from the classical approaches and with diffusion Monte Carlo results allows to examine the importance of both the QM and thermal effects.

  11. Magnetic monopoles and dyons revisited: A useful contribution to the study of classical mechanics

    CERN Document Server

    Santos, Renato P dos

    2015-01-01

    Graduate level physics curricula in many countries around the world, as well as senior-level undergraduate ones in some major institutions, include Classical Mechanics courses, mostly based on Goldstein's textbook masterpiece. During the discussion of central force motion, however, the Kepler problem is virtually the only serious application presented. In this paper, we present another problem that is also soluble, namely the interaction of Schwinger's dual-charged (dyon) particles. While the electromagnetic interaction of magnetic monopoles and electric charges was studied in detail some 40 years ago, we consider that a pedagogical discussion of it from an essentially classical mechanics point of view is a useful contribution for students. Following a path that generalizes Kepler's problem and Rutherford scattering, we show that they exhibit remarkable properties such as stable non-planar orbits, as well as rainbow and glory scattering, which are not present in the ordinary scattering of two singly charged p...

  12. The role of plant properties in arm trajectory formation: a neural network study.

    Science.gov (United States)

    Massone, L E; Myers, J D

    1996-01-01

    In this paper, we first introduce a neural network model of a planar, six-muscle, redundant arm whose structure and operation principles were inspired by those of the human arm. We developed the model with a motor-learning framework in mind, i.e., with the long-term goal of incorporating it in a parallel distributed learning scheme for the arm controller. We then demonstrate the response of the model to various patterns of activation of the arm muscles in order to study the relative role of control strategies and plant properties in trajectory formation. The results of our simulations emphasize the role of the intrinsic properties of the plant in generating movements with anthropomorphic qualities such as smoothness and unimodal velocity profiles, and demonstrate that the task of an eventual controller for the arm could be simply that of programming the amplitudes and durations of steps of neural input without considering additional motor details. Our findings are relevant to the design of artificial arms and, with some caveats, to the study of the brain strategies in the arm motor system.

  13. Periconception Maternal Folate Status and Human Embryonic Cerebellum Growth Trajectories: The Rotterdam Predict Study.

    Directory of Open Access Journals (Sweden)

    Irene V Koning

    Full Text Available We aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6 weeks gestational age (GA. Viable non-malformed singleton pregnancies were selected for cerebellar measurements; transcerebellar diameter, (TCD, left and right cerebellar diameters (LCD, RCD. Linear mixed models were performed to estimate associations between questionnaire data on the timing of maternal folic acid supplement initiation and longitudinal cerebellar measurements as a function of crown-rump length (CRL and GA. Maternal red blood cell folate concentrations were analysed before 8 weeks GA to validate the associations. A total of 263 serial high quality three-dimensional ultrasound scans of 135 pregnancies were studied. Preconceptional compared to postconceptional initiation of folic acid use was associated with slightly larger cerebellar diameters per millimetre increase of CRL (TCD: β = 0.260mm, 95%CI = 0.023-0.491, p<0.05; LCD: β = 0.171mm, 95%CI = 0.038-0.305, p<0.05; RCD: β = 0.156mm, 95%CI = 0.032-0.280, p<0.05 and with proportional cerebellar growth (TCD/CRL:β = 0.015mm/mm, 95%CI = 0.005-0.024, p<0.01; LCD/CRL:β = 0.012mm/mm, 95%CI = 0.005-0.018, p<0.01; RCD/CRL:β = 0.011mm/mm, 95%CI = 0.005-0.017, p<0.01. Cerebellar growth was significantly highest in the third quartile of maternal red blood cell folate levels (1538-1813 nmol/L. These first findings show that periconceptional maternal folate status is associated with human embryonic cerebellar development. Implications of these small but significant variations for fetal cerebellar growth trajectories and the child's neurodevelopmental outcome are yet unknown and warrant further investigation.

  14. Classic yin and yang tonic formula for osteopenia: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Holz Jonathan D

    2011-08-01

    Full Text Available Abstract Background Osteoporosis is a growing worldwide problem, with the greatest burden resulting from fractures. Nevertheless, the majority of fractures in adults occur in those with "osteopenia" (bone mineral density (BMD only moderately lower than young normal individuals. Since long-term drug therapy is an expensive option with uncertain consequences and side effects, natural herbal therapy offers an attractive alternative. The purpose of this study is to evaluate the effect on BMD and safety of the Classic Yin and Yang Tonic Formula for treatment of osteopenia and to investigate the mechanism by which this efficacy is achieved. Methods/design We propose a multicenter double-blind randomized placebo-controlled trial to evaluate the efficacy and safety of the Classic Yin and Yang Tonic Formula for the treatment of osteopenia. Participants aged 55 to 75 with low bone mineral density (T-score between -1 and -2.5 and kidney deficiency in TCM will be included and randomly allocated into two groups: treatment group and control group. Participants in the treatment group will be treated with Classic Yin and Yang Tonic Granule, while the controlled group will receive placebo. Primary outcome measure will be BMD of the lumbar spine and proximal femur using dual-energy X-ray absorptiometry. Secondary outcomes will include pain intensity measured with visual analogue scales, quality of life, serum markers of bone metabolism, indices of Neuro-endocrino-immune network and safety. Discussion If the Classic Yin and Yang Tonic Formula can increase bone mass without adverse effects, it may be a novel strategy for the treatment of osteoporosis. Furthermore, the mechanism of the Chinese medical formula for osteoporosis will be partially elucidated. Trial registration This study is registered at ClinicalTrials.gov, NCT01271647.

  15. Studying thin film damping in a micro-beam resonator based on non-classical theories

    Science.gov (United States)

    Ghanbari, Mina; Hossainpour, Siamak; Rezazadeh, Ghader

    2016-06-01

    In this paper, a mathematical model is presented for studying thin film damping of the surrounding fluid in an in-plane oscillating micro-beam resonator. The proposed model for this study is made up of a clamped-clamped micro-beam bound between two fixed layers. The micro-gap between the micro-beam and fixed layers is filled with air. As classical theories are not properly capable of predicting the size dependence behaviors of the micro-beam, and also behavior of micro-scale fluid media, hence in the presented model, equation of motion governing longitudinal displacement of the micro-beam has been extracted based on non-local elasticity theory. Furthermore, the fluid field has been modeled based on micro-polar theory. These coupled equations have been simplified using Newton-Laplace and continuity equations. After transforming to non-dimensional form and linearizing, the equations have been discretized and solved simultaneously using a Galerkin-based reduced order model. Considering slip boundary conditions and applying a complex frequency approach, the equivalent damping ratio and quality factor of the micro-beam resonator have been obtained. The obtained values for the quality factor have been compared to those based on classical theories. We have shown that applying non-classical theories underestimate the values of the quality factor obtained based on classical theories. The effects of geometrical parameters of the micro-beam and micro-scale fluid field on the quality factor of the resonator have also been investigated.

  16. Studying thin film damping in a micro-beam resonator based on non-classical theories

    Institute of Scientific and Technical Information of China (English)

    Mina Ghanbari; Siamak Hossainpour; Ghader Rezazadeh

    2016-01-01

    In this paper, a mathematical model is presented for studying thin film damping of the surrounding fluid in an in-plane oscillating micro-beam resonator. The proposed model for this study is made up of a clamped-clamped micro-beam bound between two fixed layers. The micro-gap between the micro-beam and fixed layers is filled with air. As classical theories are not properly capable of pre-dicting the size dependence behaviors of the micro-beam, and also behavior of micro-scale fluid media, hence in the presented model, equation of motion governing longitudinal displacement of the micro-beam has been extracted based on non-local elasticity theory. Furthermore, the fluid field has been modeled based on micro-polar theory. These coupled equations have been simplified using Newton-Laplace and continuity equations. After transforming to non-dimensional form and linearizing, the equations have been discretized and solved simultaneously using a Galerkin-based reduced order model. Considering slip boundary conditions and applying a complex frequency approach, the equivalent damping ratio and quality factor of the micro-beam resonator have been obtained. The obtained values for the quality factor have been compared to those based on classical theories. We have shown that applying non-classical theories underestimate the values of the quality factor obtained based on classical theo-ries. The effects of geometrical parameters of the micro-beam and micro-scale fluid field on the quality factor of the res-onator have also been investigated.

  17. Trajectories of problem video gaming among adult regular gamers: an 18-month longitudinal study.

    Science.gov (United States)

    King, Daniel L; Delfabbro, Paul H; Griffiths, Mark D

    2013-01-01

    A three-wave, longitudinal study examined the long-term trajectory of problem gaming symptoms among adult regular video gamers. Potential changes in problem gaming status were assessed at two intervals using an online survey over an 18-month period. Participants (N=117) were recruited by an advertisement posted on the public forums of multiple Australian video game-related websites. Inclusion criteria were being of adult age and having a video gaming history of at least 1 hour of gaming every week over the past 3 months. Two groups of adult video gamers were identified: those players who did (N=37) and those who did not (N=80) identify as having a serious gaming problem at the initial survey intake. The results showed that regular gamers who self-identified as having a video gaming problem at baseline reported more severe problem gaming symptoms than normal gamers, at all time points. However, both groups experienced a significant decline in problem gaming symptoms over an 18-month period, controlling for age, video gaming activity, and psychopathological symptoms.

  18. AIDS-related illness trajectories in Mexico: findings from a qualitative study in two marginalized communities.

    Science.gov (United States)

    Castro, R; Orozco, E; Eroza, E; Manca, M C; Hernández, J J; Aggleton, P

    1998-10-01

    This paper describes findings from a recent study examining how people affected directly and indirectly by the HIV/AIDS epidemic cope with HIV-related illness in Mexico. One-hundred-and-thirteen in-depth interviews were conducted with key informants in two contrasting communities: Ciudad Netzahualcóyotl (an economically marginalized community) and the gay community in Mexico City (a sexually marginalized community). This paper describes the AIDS-related wellness/illness careers or trajectories followed by individuals in both communities, and identifies critical points for material and emotional intervention. This career comprises four stages: (1) life before infection; (2) life surrounding the discovery of seropositivity; (3) living as an HIV-positive person; and (4) facing death. Comparisons are drawn between the processes of adjustment and coping found in both communities. In Ciudad Netzahualcóyotl, wellness/illness careers are closely linked to prevailing poverty and oppression, as well as the sense of urgency in which local people live their lives. In the case of the gay community, wellness/illness careers are associated with the intolerance and social repression faced by homosexual men. The paper concludes by suggesting possible interventions to improve the lives of people with HIV/AIDS in Mexico today.

  19. Trajectories of dietary change and the social context of migration: a qualitative study.

    Science.gov (United States)

    Bojorquez, Ietza; Rentería, Daniela; Unikel, Claudia

    2014-10-01

    The aim of this article was to explore the influence of migration on changes in dietary practices, relating these changes to the social contexts in which they occur. Numerous studies have described how migration from poor countries and regions to more developed ones leads migrants to adopt a modern diet associated to the risk of acquiring chronic diseases. However, different contexts might influence dietary change in migrants in diverse ways. For this purpose, 28 semi-structured interviews were conducted with adult, female internal migrants to a border city in Mexico. The interviews were analyzed using thematic analysis. The results showed trajectories of dietary change to be associated to social position before and after migration. For the participants from rural areas, migration was accompanied by an increase in the consumption of processed foods, and also changes in food insecurity. Migrants who came from urban areas reported a decrease in the perceived quality of food available to them, but their eating pattern was modified only slightly. For some interviewees, migration resulted in the possibility to choose what to eat in a more autonomous way. We discuss how the effect of migration on dietary changes can be manifold, and the necessity to delve into how social context influences these changes.

  20. Oxygen precipitation in silicon: Experimental studies and theoretical investigations within the classical theory of nucleation

    Science.gov (United States)

    Kelton, K. F.; Falster, R.; Gambaro, D.; Olmo, M.; Cornara, M.; Wei, P. F.

    1999-06-01

    Quantitative measurements of the oxygen precipitate rate as a function of annealing were made in Czochralski-grown silicon wafers that contained different initial concentrations of oxygen. All wafers were annealed at 1000 °C for 15 min to ensure that the initial cluster-size distributions were identical in all samples of the same composition prior to the multi-step annealing treatments used for the precipitation studies. The experimental data are compared with numerical predictions for time-dependent nucleation within the classical theory of nucleation. Quantitative agreement is obtained between the measured and calculated densities of oxygen precipitates for nucleation temperatures greater than 600 °C, but only over a narrow range of oxygen composition. Below 600 °C, the measured density for all samples is orders of magnitude larger than is predicted from the model. Further, the measured data show an anomalously small temperature dependence for the induction time for nucleation that does not scale with the diffusion coefficient, as expected from the classical theory of nucleation. Fundamentally, the classical theory of nucleation cannot explain the time-dependent nucleation of oxygen precipitates for temperatures below 650 °C. A possible reason is given.

  1. Magnetic monopoles and dyons revisited: a useful contribution to the study of classical mechanics

    Science.gov (United States)

    dos Santos, Renato P.

    2015-05-01

    Graduate-level physics curricula in many countries around the world, as well as senior-level undergraduate ones in some major institutions, include classical mechanics courses, mostly based on Goldstein’s textbook masterpiece. During the discussion of central force motion, however, the Kepler problem is virtually the only serious application presented. In this paper, we present another problem that is also soluble, namely the interaction of Schwinger’s dual-charged (dyon) particles. While the electromagnetic interaction of magnetic monopoles and electric charges was studied in detail some 40 years ago, we consider that a pedagogical discussion of it from an essentially classical mechanics point of view is a useful contribution for students. Following a path that generalizes Kepler’s problem and Rutherford scattering, we show that they exhibit remarkable properties such as stable non-planar orbits, as well as rainbow and glory scattering, which are not present in the ordinary scattering of two singly charged particles. Moreover, it can be extended further to the relativistic case and to a semi-classical quantization, which can also be included in the class discussion.

  2. A SIMULATION STUDY OF DEPOSITION UNDER TWO TYPES OF IMPINGING TRAJECTORIES

    Institute of Scientific and Technical Information of China (English)

    X.Q. Wei; L. Zhou

    2004-01-01

    A model coupling particle aggregation and randomwalk surface diffusion has been developed for 2D simulation of depositionalgrowth, in which impinging particles follow either a straight-line trajectory of cosine distribution, representing typically sputter deposition, or a scattered trajectory, representing typically electrochemical deposition.Simulations of the growth under various impinging conditions and effective surface diffusivity have been carried out. Pattern and defect development in deposition on flat,trenched and ridged substrates have been investigated. We found that on flat and ridged substrates, both types of trajectories yield similar features, including formation of cone-like defects on surface ridges. While on trenched substrate, the straight-line impingement yielded more uniform step coverage than the scattered impingement.

  3. Conditioned withdrawal in goldfish: a simple and inexpensive preparation for the study of classical fear conditioning in vertebrates.

    Science.gov (United States)

    Barela, Peter B

    2012-02-01

    Summary.-A preparation for the study of classical fear conditioning in vertebrates is described. Its unique features are that it is inexpensive and easy to construct and operate. The following classical conditioning phenomena are demonstrated using this preparation: excitatory conditioning, extinction, contextual conditioning, blocking, a conditioned inhibition discrimination, and latent inhibition.

  4. Trajectories of Marijuana Use among HIV-seropositive and HIV-seronegative MSM in the Multicenter AIDS Cohort Study (MACS), 1984-2013.

    Science.gov (United States)

    Okafor, Chukwuemeka N; Cook, Robert L; Chen, Xinguang; Surkan, Pamela J; Becker, James T; Shoptaw, Steve; Martin, Eileen; Plankey, Michael W

    2017-04-01

    To construct longitudinal trajectories of marijuana use in a sample of men who have sex with men living with or at-risk for HIV infection. We determined factors associated with distinct trajectories of use as well as those that serve to modify the course of the trajectory. Data were from 3658 [1439 HIV-seropositive (HIV+) and 2219 HIV-seronegative (HIV-)] participants of the Multicenter AIDS Cohort Study. Frequency of marijuana use was obtained semiannually over a 29-year period (1984-2013). Group-based trajectory models were used to identify the trajectories and to determine predictors and modifiers of the trajectories over time. Four distinct trajectories of marijuana use were identified: abstainer/infrequent (65 %), decreaser (13 %), increaser (12 %) and chronic high (10 %) use groups. HIV+ status was significantly associated with increased odds of membership in the decreaser, increaser and chronic high use groups. Alcohol, smoking, stimulant and other recreational drug use were associated with increasing marijuana use across all four trajectory groups. Antiretroviral therapy use over time was associated with decreasing marijuana use in the abstainer/infrequent and increaser trajectory groups. Having a detectable HIV viral load was associated with increasing marijuana use in the increaser group only. Future investigations are needed to determine whether long-term patterns of use are associated with adverse consequences especially among HIV+ persons.

  5. The dissociative chemisorption of methane on Ni(100) and Ni(111): classical and quantum studies based on the reaction path Hamiltonian.

    Science.gov (United States)

    Mastromatteo, Michael; Jackson, Bret

    2013-11-21

    Electronic structure methods based on density functional theory are used to construct a reaction path Hamiltonian for CH4 dissociation on the Ni(100) and Ni(111) surfaces. Both quantum and quasi-classical trajectory approaches are used to compute dissociative sticking probabilities, including all molecular degrees of freedom and the effects of lattice motion. Both approaches show a large enhancement in sticking when the incident molecule is vibrationally excited, and both can reproduce the mode specificity observed in experiments. However, the quasi-classical calculations significantly overestimate the ground state dissociative sticking at all energies, and the magnitude of the enhancement in sticking with vibrational excitation is much smaller than that computed using the quantum approach or observed in the experiments. The origin of this behavior is an unphysical flow of zero point energy from the nine normal vibrational modes into the reaction coordinate, giving large values for reaction at energies below the activation energy. Perturbative assumptions made in the quantum studies are shown to be accurate at all energies studied.

  6. Investigation of four distinct glottal configurations in classical singing--a pilot study.

    Science.gov (United States)

    Herbst, Christian T; Ternström, Sten; Svec, Jan G

    2009-03-01

    This study investigates four qualities of singing voice in a classically trained baritone: "naive falsetto," "countertenor falsetto," "lyrical chest" and "full chest." Laryngeal configuration and vocal fold behavior in these qualities were studied using laryngeal videostroboscopy, videokymography, electroglottography, and sound spectrography. The data suggest that the four voice qualities were produced by independently manipulating mainly two laryngeal parameters: (1) the adduction of the arytenoid cartilages and (2) the thickening of the vocal folds. An independent control of the posterior adductory muscles versus the vocalis muscle is considered to be the physiological basis for achieving these singing voice qualities.

  7. Studies on the s_dm.t=f verb form in Classical Egyptian

    OpenAIRE

    Zonhoven, Ludovicus Martinus Johannes

    1997-01-01

    This study is devoted to some synchronic aspects of the sDm.t=f verb form, primarily its meaning and uses in Classical Egyptian. In the introduction some attention is paid to the history of the studies of the form and its origin, an aspect which will receive no further consideration. In accordance with present common opinion the sDm.t=f is here considered to belong to the suffix conjugation. Ch. I is primarily concerned with the active Dr sDm.t=f construction, but begins with a general introd...

  8. Classical antiparticles

    Energy Technology Data Exchange (ETDEWEB)

    Costella, J.P.; McKellar, B.H.J.; Rawlinson, A.A.

    1997-03-01

    We review how antiparticles may be introduced in classical relativistic mechanics, and emphasize that many of their paradoxical properties can be more transparently understood in the classical than in the quantum domain. (authors). 13 refs., 1 tab.

  9. Classical antiparticles

    CERN Document Server

    Costella, J P; Rawlinson, A A; Costella, John P.; Kellar, Bruce H. J. Mc; Rawlinson, Andrew A.

    1997-01-01

    We review how antiparticles may be introduced in classical relativistic mechanics, and emphasize that many of their paradoxical properties can be more transparently understood in the classical than in the quantum domain.

  10. The injury trajectory for young people 16-24 years in the six months following injury: A mixed methods study.

    Science.gov (United States)

    Ogilvie, Rebekah; Foster, Kim; McCloughen, Andrea; Curtis, Kate

    2016-09-01

    Adolescents and young people are the population at greatest risk of injury and therefore injury-related mortality and morbidity. Inquiry into the injury trajectory of young people is needed to identify this group's specific needs for healthcare. This paper reports the integration of quantitative and qualitative findings from a sequential explanatory mixed methods study examining young people aged 16-24 years' experience and trajectory of traumatic physical injury in the initial six months. The aim of integration was to address the question: In what ways are injured young peoples' experiences and self-management during the initial six months of the injury trajectory impacted by their injury, family support, and provision of healthcare? Key findings from epidemiological datasets on young person injuries from hospital and coronial databases (Phase 1) were combined with key findings from qualitative interviews with 12 injured young people and 10 family members (Phase 2). The integration of findings from Phase 1 and Phase 2 resulted in three new findings; [1] (Alfred Health, 2014). A young person's perception of the severity of their injury, as well as the amount of time spent in hospital, impacts substantially on the way in which they experience injury, and this is managed differently between genders; [2] (Newnam et al., 2014). Admission to an Intensive care unit, including the intensity and duration of care, is the primary influence on how a family will provide support to the young person in the inpatient period; and [3] (Lyons et al., 2010). Young people's perception and understanding of their recovery from injury is in contrast with how healthcare systems are structured to provide rehabilitation and recovery care. The injury trajectory and recovery process of young people in the six months following injury have been have conceptualised. These trajectories of recovery can inform the development of anticipatory guidance frameworks for clinicians and guide the

  11. What can providers learn from childhood body mass index trajectories: a study of a large, safety-net clinical population.

    Science.gov (United States)

    McCormick, Emily V; Dickinson, L Miriam; Haemer, Matthew A; Knierim, Shanna D; Hambidge, Simon J; Davidson, Arthur J

    2014-01-01

    To describe childhood weight gain using body mass index (BMI) z-score trajectories in a low-income urban safety-net population and identify among gender- and race/ethnicity-specific groups any trends for increased risk. A retrospective cohort study was conducted among 2- to 12-year-old patients (2006-2013) visiting a safety-net provider. BMI z-score trajectories were calculated overall, for gender- and race/ethnicity-specific groups, and for peak BMI percentile subgroups to describe weight gain longitudinally. From 2006 to 2013, a total of 26,234 eligible children were followed for an average of 3.7 years. At baseline (mean age, 4.2 years), 74% of patients were at a normal weight compared to 65% at most recent observation (mean age, 7.8 years). All gender and race/ethnicity subgroups showed increasing average BMI z-scores during childhood. Children consistently under the 50th percentile and those of white race had the most stable BMI z-score trajectories. BMI z-score increased with increasing age in all subgroups. Hispanic boys and black girls had the most significant increase in BMI z-score during this observation period. Children observed in early childhood and whose BMI exceeded the 95th percentile at any time were often already overweight (20%) or obese (36%) by 3 years of age. The entire population demonstrated an upward trend in BMI z-score trajectory. This trend was most notable among black girls and Hispanic boys. Many obese children were already overweight by age 3, and persistence of obesity after 3 years of age was high, suggesting that intervention before age 3 may be essential to curbing unhealthy weight trajectories. Copyright © 2014 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  12. Design Decisions in Developing Learning Trajectories-Based Assessments in Mathematics: A Case Study

    Science.gov (United States)

    Penuel, William R.; Confrey, Jere; Maloney, Alan; Rupp, André A.

    2014-01-01

    This article analyzes the design decisions of a team developing diagnostic assessments for a learning trajectory focused on rational number reasoning. The analysis focuses on the design rationale for key decisions about how to develop the cognitive assessments and related validity arguments within a fluid state and national policy context. The…

  13. The Career Trajectories of English Language Teachers. Oxford Studies in Comparative Education

    Science.gov (United States)

    Haworth, Penny, Ed.; Craig, Cheryl, Ed.

    2016-01-01

    This volume identifies, illustrates, compares, contrasts and provides informed reflective commentary on the diverse career trajectories of English language teachers, teacher educators and researchers. Increased migration and globalisation pressures have led to dramatic changes in English language teaching over the last few decades. The resulting…

  14. Periconception Maternal Folate Status and Human Embryonic Cerebellum Growth Trajectories : The Rotterdam Predict Study

    NARCIS (Netherlands)

    Koning, Irene V; Groenenberg, Irene A L; Gotink, Anniek W; Willemsen, Sten P; Gijtenbeek, Manon; Dudink, Jeroen; Go, Attie T J I; Reiss, Irwin K M; Steegers, Eric A P; Steegers-Theunissen, Régine P M

    2015-01-01

    We aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6 weeks

  15. Periconception maternal folate status and human embryonic cerebellum growth trajectories: The Rotterdam predict study

    NARCIS (Netherlands)

    I.V. Koning (Irene); I.A.L. Groenenberg (Irene); A.W. Gotink (Anniek W.); S. Willemsen (Sp); M. Gijtenbeek (M.); J. Dudink (Jeroen); A.T.J.I. Go (Attie T. J. I.); I.K.M. Reiss (Irwin); E.A.P. Steegers (Eric); R.P.M. Steegers-Theunissen (Régine)

    2015-01-01

    textabstractWe aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6

  16. Assessing transition trajectories towards a sustainable energy system: A case study on the Dutch transition to climate-neutral transport fuel chains

    NARCIS (Netherlands)

    Suurs, R.A.A.; Hekkert, M.P.; Meeus, M.T.H.; Nieuwlaar, E.

    2004-01-01

    This paper proposes a method for the ex ante evaluation of technological trajectories. As a case we study the Dutch transport energy system and its transition to climate neutrality. Two technological trajectories are proposed: (i) a sequence of transition steps based on radical infrastructural chang

  17. Trajectories in Operating a Handheld Tool

    Science.gov (United States)

    Heuer, Herbert; Sulzenbruck, Sandra

    2009-01-01

    The authors studied the trajectories of the hand and of the tip of a handheld sliding first-order lever in aiming movements. With this kind of tool, straight trajectories of the hand are generally associated with curved trajectories of the tip of the lever and vice versa. Trajectories of the tip of the lever exhibited smaller deviations from…

  18. Trajectories in Operating a Handheld Tool

    Science.gov (United States)

    Heuer, Herbert; Sulzenbruck, Sandra

    2009-01-01

    The authors studied the trajectories of the hand and of the tip of a handheld sliding first-order lever in aiming movements. With this kind of tool, straight trajectories of the hand are generally associated with curved trajectories of the tip of the lever and vice versa. Trajectories of the tip of the lever exhibited smaller deviations from…

  19. Finite-size scaling study of the three-dimensional classical Heisenberg model

    CERN Document Server

    Holm, C; Holm, Christian; Janke, Wolfhard

    1993-01-01

    We use the single-cluster Monte Carlo update algorithm to simulate the three-dimensional classical Heisenberg model in the critical region on simple cubic lattices of size $L^3$ with $L=12, 16, 20, 24, 32, 40$, and $48$. By means of finite-size scaling analyses we compute high-precision estimates of the critical temperature and the critical exponents, using extensively histogram reweighting and optimization techniques. Measurements of the autocorrelation time show the expected reduction of critical slowing down at the phase transition. This allows simulations on significantly larger lattices than in previous studies and consequently a better control over systematic errors in finite-size scaling analyses.

  20. Symptom Trajectories Among Child Survivors of Maltreatment: Findings from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN).

    Science.gov (United States)

    Lauterbach, Dean; Armour, Cherie

    2016-02-01

    Very few studies have investigated the longitudinal trajectory of depression and anxiety related symptomatology among child victims of maltreatment or among those at risk for maltreatment. The current study examined latent class trajectories of anxiety/depression symptoms in a sample of 1354 (n = 657 boys, n = 697 girls) victimized or at risk children using data collected from the Longtitudinal Studies of Child Abuse and Neglect (LONGSCAN). Four trajectory groups were identified labeled low-stable, moderate-stable, moderate-increasing, and high-decreasing. This study also sought to investigate predictors of group membership. Relative to the low-stable group, membership in the three more pathological groups (i.e., moderate-stable, moderate-increasing, and high-decreasing) was predicted by a greater number of maltreatment allegations, more visits to a primary care physician for psychological issues, less perceived support by primary maternal caregiver, and lower rated popularity of the child. Implications for early identification of child maltreatment victims in primary health care settings was discussed.

  1. Target selection and transfer trajectories design for exploring asteroid mission

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Technique of target selection and profiles of transfer trajectory for Chinese asteroid exploring mission are studied systemically.A complete set of approaches to selecting mission targets and designing the transfer trajectory is proposed.First,when selecting a target for mission,some factors regarded as the scientific motivations are discussed.Then,when analyzing the accessibility of targets,instead of the classical strategy,the multiple gravity-assist strategy is provided.The suitable and possible targets,taking into account scientific value and technically feasible,are obtained via selection and estimation.When designing the transfer trajectory for exploring asteroid mission,an approach to selecting gravity-assist celestial body is proposed.Finally,according to the mission constraints,the trajectory profile with 2-years △V-EGA for exploring asteroid is presented.Through analyzing the trajectory profile,unexpected result that the trajectory would pass by two main-belts asteroids is found.So,the original proposal is extended to the multiple flybys mission.It adds the scientific return for asteroid mission.

  2. Associations of education with 30 year life course blood pressure trajectories: Framingham Offspring Study

    Directory of Open Access Journals (Sweden)

    Xiao Yongling

    2011-02-01

    Full Text Available Abstract Background Education is inversely associated with cardiovascular disease incidence in developed countries. Blood pressure may be an explanatory biological mechanism. However few studies have investigated educational gradients in longitudinal blood pressure trajectories, particularly over substantial proportions of the life course. Study objectives were to determine whether low education was associated with increased blood pressure from multiple longitudinal assessments over 30 years. Furthermore, we aimed to separate antecedent effects of education, and other related factors, that might have caused baseline differences in blood pressure, from potential long-term effects of education on post-baseline blood pressure changes. Methods The study examined 3890 participants of the Framingham Offspring Study (mean age 36.7 years, 52.0% females at baseline from 1971 through 2001 at up to 7 separate examinations using multivariable mixed linear models. Results Mixed linear models demonstrated that mean systolic blood pressure (SBP over 30 years was higher for participants with ≤12 vs. ≥17 years education after adjusting for age (3.26 mmHg, 95% CI: 1.46, 5.05 in females, 2.26 mmHg, 95% CI: 0.87, 3.66 in males. Further adjustment for conventional covariates (antihypertensive medication, smoking, body mass index and alcohol reduced differences in females and males (2.86, 95% CI: 1.13, 4.59, and 1.25, 95% CI: -0.16, 2.66 mmHg, respectively. Additional analyses adjusted for baseline SBP, to evaluate if there may be educational contributions to post-baseline SBP. In analyses adjusted for age and baseline SBP, females with ≤12 years education had 2.69 (95% CI: 1.09, 4.30 mmHg higher SBP over follow-up compared with ≥17 years education. Further adjustment for aforementioned covariates slightly reduced effect strength (2.53 mmHg, 95% CI: 0.93, 4.14. Associations were weaker in males, where those with ≤12 years education had 1.20 (95% CI: -0

  3. Socioeconomic position predicts long-term depression trajectory: a 13-year follow-up of the GAZEL cohort study.

    Science.gov (United States)

    Melchior, M; Chastang, J-F; Head, J; Goldberg, M; Zins, M; Nabi, H; Younès, N

    2013-01-01

    Individuals with low socioeconomic position have high rates of depression; however, it is not clear whether this reflects higher incidence or longer persistence of disorder. Past research focused on high-risk samples, and risk factors of long-term depression in the population are less well known. Our aim was to test the hypothesis that socioeconomic position predicts depression trajectory over 13 years of follow-up in a community sample. We studied 12 650 individuals participating in the French GAZEL study. Depression was assessed by the Center for Epidemiological Studies-Depression scale in 1996, 1999, 2002, 2005 and 2008. These five assessments served to estimate longitudinal depression trajectories (no depression, decreasing depression, intermediate/increasing depression, persistent depression). Socioeconomic position was measured by occupational grade. Covariates included year of birth, marital status, tobacco smoking, alcohol consumption, body mass index, negative life events and preexisting psychological and non-psychological health problems. Data were analyzed using multinomial regression, separately in men and women. Overall, participants in intermediate and low occupational grades were significantly more likely than those in high grades to have an unfavorable depression trajectory and to experience persistent depression (age-adjusted ORs: respectively 1.40, 95% confidence interval (CI) 1.16-1.70 and 2.65, 95% CI 2.04-3.45 in men, 2.48, 95% CI 1.36-4.54 and 4.53, 95% CI 2.38-8.63 in women). In multivariate models, the socioeconomic gradient in long-term depression decreased by 21-59% in men and women. Long-term depression trajectories appear to follow a socioeconomic gradient; therefore, efforts aiming to reduce the burden of depression should address the needs of the whole population rather than exclusively focus on high-risk groups.

  4. Telomere length trajectory and its determinants in persons with coronary artery disease: longitudinal findings from the heart and soul study.

    Directory of Open Access Journals (Sweden)

    Ramin Farzaneh-Far

    Full Text Available BACKGROUND: Leukocyte telomere length, an emerging marker of biological age, has been shown to predict cardiovascular morbidity and mortality. However, the natural history of telomere length in patients with coronary artery disease has not been studied. We sought to investigate the longitudinal trajectory of telomere length, and to identify the independent predictors of telomere shortening, in persons with coronary artery disease. METHODOLOGY/PRINCIPAL FINDINGS: In a prospective cohort study of 608 individuals with stable coronary artery disease, we measured leukocyte telomere length at baseline, and again after five years of follow-up. We used multivariable linear and logistic regression models to identify the independent predictors of leukocyte telomere trajectory. Baseline and follow-up telomere lengths were normally distributed. Mean telomere length decreased by 42 base pairs per year (p<0.001. Three distinct telomere trajectories were observed: shortening in 45%, maintenance in 32%, and lengthening in 23% of participants. The most powerful predictor of telomere shortening was baseline telomere length (OR per SD increase = 7.6; 95% CI 5.5, 10.6. Other independent predictors of telomere shortening were age (OR per 10 years = 1.6; 95% CI 1.3, 2.1, male sex (OR = 2.4; 95% CI 1.3, 4.7, and waist-to-hip ratio (OR per 0.1 increase = 1.4; 95% CI 1.0, 2.0. CONCLUSIONS/SIGNIFICANCE: Leukocyte telomere length may increase as well as decrease in persons with coronary artery disease. Telomere length trajectory is powerfully influenced by baseline telomere length, possibly suggesting negative feedback regulation. Age, male sex, and abdominal obesity independently predict telomere shortening. The mechanisms and reversibility of telomeric aging in cardiovascular disease deserve further study.

  5. Pedestrian Crosswalk Law: A study of traffic and trajectory factors that affect non-compliance and stopping distance.

    Science.gov (United States)

    Figliozzi, Miguel A; Tipagornwong, Chawalit

    2016-11-01

    Walking is encouraged by many transportation agencies as a sustainable mode that contributes to livable downtowns. Since pedestrians are the most vulnerable road users, safe and comfortable crosswalks are essential to ensure that pedestrian travel becomes an appealing alternative. In this context, the goal of this research is to study the traffic and vehicle trajectory factors that affect crosswalk law compliance and stopping distance from the crosswalk. The results of this research provide new insights into the relationships between traffic conditions, vehicle trajectory, and compliance rates. Results indicate that vehicle origin, vehicle type, stopping at upstream traffic lights, and changes in vehicle speed and headways are key factors to predict pedestrian crosswalk law compliance and stopping behavior; changes in vehicle speed and headways have the highest explanatory power.

  6. Experimentally measured susceptibility to peer influence and adolescent sexual behavior trajectories: A preliminary study.

    Science.gov (United States)

    Choukas-Bradley, Sophia; Giletta, Matteo; Widman, Laura; Cohen, Geoffrey L; Prinstein, Mitchell J

    2014-09-01

    A performance-based measure of peer influence susceptibility was examined as a moderator of the longitudinal association between peer norms and trajectories of adolescents' number of sexual intercourse partners. Seventy-one 9th grade adolescents (52% female) participated in an experimental "chat room" paradigm involving "e-confederates" who endorsed sexual risk behaviors. Changes in participants' responses to risk scenarios before versus during the "chat room" were used as a performance-based measure of peer influence susceptibility. Participants reported their perceptions of popular peers' number of sexual intercourse partners at baseline and self-reported their number of sexual intercourse partners at baseline and 6, 12, and 18 months later. Susceptibility was examined as a moderator of the longitudinal association between perceptions of popular peers' number of sexual intercourse partners and trajectories of adolescents' own numbers of partners. High perceptions of the number of popular peers' sexual intercourse partners combined with high peer influence susceptibility predicted steeper longitudinal trajectories of adolescents' number of partners. Results provide novel preliminary evidence regarding the importance of peer influence susceptibility in adolescents' development of sexual behaviors.

  7. A comparative study of classical and biochemical endpoints for phytotoxicity testing of chlorobenzoic acids

    Institute of Scientific and Technical Information of China (English)

    LI Pei-jun; YIN Pei-jie; ZHOU Qi-xing; SHI Xing-qun; XIONG Xian-zhe

    2005-01-01

    The phytotoxicity of chlorobenzoic acids(CBAs) was studied and the biochemical endpoints' suitability and sensibility was evaluated. Two terrestrial plant species in the same family were exposed to different concentrations of CBAS and tested their germination according to the guideline of Organization for Economic Cooperation and Development(OECP, 1984). The results showed that CBA doseinhibition rate of classical endpoint had the distinct linear relationship in the range of 10%-50% inhibition rate for root elongation( p <0.01), and the dose variances of CBAs had the greater influence on the inhibition rate of germination than on inhibition rate of root elongation. The CBA dose half effect concentration-inhibition rate of two antioxidant enzyme activity superoxide dismutase(SOD) and catalase (CAT) had the quadratic relationship, and CBA dose-inhibition rate of the peroxides(POD) activity had the linear relationship( p<0.05). Comparing the half effect concentration (EC50 ) of two kinds of endpoints, the POD activity was more sensitive than classical endpoint, however, SOD and CAT activity were not sensitive in the experiment.

  8. Identifying Latent Trajectories of Personality Disorder Symptom Change: Growth Mixture Modeling in the Longitudinal Study of Personality Disorders

    Science.gov (United States)

    Hallquist, Michael N.; Lenzenweger, Mark F.

    2013-01-01

    Although previous reports have documented mean-level declines in personality disorder (PD) symptoms over time, little is known about whether personality pathology sometimes emerges among nonsymptomatic adults, or whether rates of change differ qualitatively among symptomatic persons. Our study sought to characterize heterogeneity in the longitudinal course of PD symptoms with the goal of testing for and describing latent trajectories. Participants were 250 young adults selected into two groups using a PD screening measure: those who met diagnostic criteria for a DSM-III-R PD (PPD, n = 129), and those with few PD symptoms (NoPD, n = 121). PD symptoms were assessed three times over a four-year study using semistructured interviews. Total PD symptom counts and symptoms of each DSM-III-R PD were analyzed using growth mixture modeling. In the NoPD group, latent trajectories were characterized by stable, minor symptoms; the rapid or gradual remission of subclinical symptoms; or the emergence of symptoms of Avoidant, Obsessive-Compulsive, or Paranoid PD. In the PPD group, three latent trajectories were evident: rapid symptom remission, slow symptom decline, or a relative absence of symptoms. Rapid remission of PD symptoms was associated with fewer comorbid disorders, lower negative emotionality, and greater positive emotionality and constraint, whereas emergent personality dysfunction was associated with comorbid PD symptoms and lower positive emotionality. In most cases, symptom change for one PD was associated with concomitant changes in other PDs, depressive symptoms, and anxiety. These results indicate that the longitudinal course of PD symptoms is heterogeneous, with distinct trajectories evident for both symptomatic and nonsymptomatic individuals. The prognosis of PD symptoms may be informed by an assessment of personality and comorbid psychopathology. PMID:23231459

  9. Identifying latent trajectories of personality disorder symptom change: growth mixture modeling in the longitudinal study of personality disorders.

    Science.gov (United States)

    Hallquist, Michael N; Lenzenweger, Mark F

    2013-02-01

    Although previous reports have documented mean-level declines in personality disorder (PD) symptoms over time, little is known about whether personality pathology sometimes emerges among nonsymptomatic adults, or whether rates of change differ qualitatively among symptomatic persons. Our study sought to characterize heterogeneity in the longitudinal course of PD symptoms with the goal of testing for and describing latent trajectories. Participants were 250 young adults selected into two groups using a PD screening measure: those who met diagnostic criteria for a DSM-III-R PD (PPD, n = 129), and those with few PD symptoms (NoPD, n = 121). PD symptoms were assessed three times over a 4-year study using semistructured interviews. Total PD symptom counts and symptoms of each DSM-III-R PD were analyzed using growth mixture modeling. In the NoPD group, latent trajectories were characterized by stable, minor symptoms; the rapid or gradual remission of subclinical symptoms; or the emergence of symptoms of avoidant, obsessive-compulsive, or paranoid PD. In the PPD group, three latent trajectories were evident: rapid symptom remission, slow symptom decline, or a relative absence of symptoms. Rapid remission of PD symptoms was associated with fewer comorbid disorders, lower Negative Emotionality, and greater Positive Emotionality and Constraint, whereas emergent personality dysfunction was associated with comorbid PD symptoms and lower Positive Emotionality. In most cases, symptom change for one PD was associated with concomitant changes in other PDs, depressive symptoms, and anxiety. These results indicate that the longitudinal course of PD symptoms is heterogeneous, with distinct trajectories evident for both symptomatic and nonsymptomatic individuals. The prognosis of PD symptoms may be informed by an assessment of personality and comorbid psychopathology.

  10. The contribution of diet and genotype to iron status in women: a classical twin study.

    Directory of Open Access Journals (Sweden)

    Susan J Fairweather-Tait

    Full Text Available This is the first published report examining the combined effect of diet and genotype on body iron content using a classical twin study design. The aim of this study was to determine the relative contribution of genetic and environmental factors in determining iron status. The population was comprised of 200 BMI- and age-matched pairs of MZ and DZ healthy twins, characterised for habitual diet and 15 iron-related candidate genetic markers. Variance components analysis demonstrated that the heritability of serum ferritin (SF and soluble transferrin receptor was 44% and 54% respectively. Measured single nucleotide polymorphisms explained 5% and selected dietary factors 6% of the variance in iron status; there was a negative association between calcium intake and body iron (p = 0.02 and SF (p = 0.04.

  11. Aberrant parietal cortex developmental trajectories in girls with Turner syndrome and related visual-spatial cognitive development: a preliminary study.

    Science.gov (United States)

    Green, Tamar; Chromik, Lindsay C; Mazaika, Paul K; Fierro, Kyle; Raman, Mira M; Lazzeroni, Laura C; Hong, David S; Reiss, Allan L

    2014-09-01

    Turner syndrome (TS) arises from partial or complete absence of the X-chromosome in females. Girls with TS show deficits in visual-spatial skills as well as reduced brain volume and surface area in the parietal cortex which supports these cognitive functions. Thus, measuring the developmental trajectory of the parietal cortex and the associated visual-spatial cognition in TS may provide novel insights into critical brain-behavior associations. In this longitudinal study, we acquired structural MRI data and assessed visual-spatial skills in 16 (age: 8.23 ± 2.5) girls with TS and 13 age-matched controls over two time-points. Gray and white matter volume, surface area and cortical thickness were calculated from surfaced based segmentation of bilateral parietal cortices, and the NEPSY Arrows subtest was used to assess visual-spatial ability. Volumetric and cognitive scalars were modeled to obtain estimates of age-related change. The results show aberrant growth of white matter volume (P = 0.011, corrected) and surface area (P = 0.036, corrected) of the left superior parietal regions during childhood in girls with TS. Other parietal sub-regions were significantly smaller in girls with TS at both time-points but did not show different growth trajectories relative to controls. Furthermore, we found that visual-spatial skills showed a widening deficit for girls with TS relative to controls (P = 0.003). Young girls with TS demonstrate an aberrant trajectory of parietal cortical and cognitive development during childhood. Elucidating aberrant neurodevelopmental trajectories in this population is critical for determining specific stages of brain maturation that are particularly dependent on TS-related genetic and hormonal factors. © 2014 Wiley Periodicals, Inc.

  12. Project STARS (Studies on Trajectories of Adolescent Relationships and Sexuality) : A longitudinal, multi-domain study on sexual development of Dutch adolescents

    NARCIS (Netherlands)

    Reitz, Ellen; van de Bongardt, Daphne; Baams, Laura; Doornwaard, Suzan; Dalenberg, Wieke; Dubas, Judith; van Aken, Marcel; Overbeek, Geertjan; ter Bogt, Tom; van der Eijnden, Regina; Vanwesenbeeck, Ine; Timmerman, Greetje; Kunnen, Elske; van Geert, Paul; Dekovic, Maja

    2015-01-01

    This study gives an overview of Project STARS (Studies on Trajectories of Adolescent Relationships and Sexuality), a four-wave longitudinal study of 1297 Dutch adolescents. First, the sample, measures and four sub-projects are described. Second, hierarchical regression analyses were conducted to

  13. Project STARS (Studies on Trajectories of Adolescent Relationships and Sexuality): A longitudinal, multi-domain study on sexual development of Dutch adolescents

    NARCIS (Netherlands)

    Reitz, E.; van de Bongardt, D.; Baams, L.; Doornwaard, S.; Dalenberg, W.; Dubas, J.; van Aken, M.; Overbeek, G.; ter Bogt, T.; van der Eijnden, R.; Vanwesenbeeck, I.; Kunnen, S.; Timmerman, G.; van Geert, P.; Deković, M.

    2015-01-01

    This study gives an overview of Project STARS (Studies on Trajectories of Adolescent Relationships and Sexuality), a four-wave longitudinal study of 1297 Dutch adolescents. First, the sample, measures and four sub-projects are described. Second, hierarchical regression analyses were conducted to

  14. Combined effect of education and reproductive history on weight trajectories of young Australian women: A longitudinal study.

    Science.gov (United States)

    Holowko, Natalie; Jones, Mark; Koupil, Ilona; Tooth, Leigh; Mishra, Gita

    2016-10-01

    To investigate the combined effect of education and reproductive history on weight trajectory. The association of education with weight trajectory (1996-2012) in relation to reproductive history was analyzed among 9,336 women (born 1973-1978) from the Australian Longitudinal Study on Women's Health using random effects models. Compared with women with a university degree/higher, lower-educated women were 2 kg heavier at baseline and gained an additional 0.24 kg/year. Giving birth was associated with an increase in weight which was more pronounced among women having their first birth 32 years. While younger first-time mothers had a steeper weight trajectory (∼+0.16 kg/year, 95% CI: 0.1-0.3), this was less steep among lower-educated women. High-educated women with a second birth between 26 and 32 years had 0.9 kg decreased weight after this birth, while low-educated women gained 0.9 kg. While the effect of having children on weight in young adulthood was minimal, women having their first birth Educational differences in weight persisted after accounting for reproductive history, suggesting a need to explore alternative mechanisms through which social differences in weight are generated. © 2016 The Obesity Society.

  15. Accuracy Combination Test of Classical and Modern Technical Analysis: A Case Study in Stock of PT Wijaya Karya Tbk

    Directory of Open Access Journals (Sweden)

    Agustini Hamid

    2016-05-01

    Full Text Available The research aimed to measure the accuracy and combination of Classic and Modern Technical Analysis. PT Wijaya Karya Tbk (WIKA’s stock in two periods is the sample of research. Technical analysis was used to predict stock prices by observing changes in historical share price. Practically, technical analysis is divided into Classic Technical and Modern. Research was conducted by library study and using a computer software. Microsft Excel was used for the simulation and Chart Nexus for analyzing Modern Technical Analysis. The research period started in January 1, 2013 until December 31, 2013 and January 1, 2014 until December 31, 2014. The Classic Technical Analysis used Support, Resistance, Trendline, and Flag Patern. Meanwhile for Modern Technical Analysis used Moving Average, Stochastic, Moving Average Convergence Divergence (MACD indicator. The Classical Technical Analysis gave less result than Modern Technical Analysis. The classical give 14 investment decisions in two periods. The average return of Classical Technical is 15,50%. Meanwhile the Modern Technical Analysis gave 18 investment decisions in two periods. The average return of Modern Technical is 18,14%. Combining Classic Technical Analysis and Modern Technical Analysis gave 20 investment decisions with the average rate of return 20,41%.

  16. Semi-Classical Dynamics Studies of the Photodissociation of ICN^{-} and BrCN^{-}

    Science.gov (United States)

    Opoku-Agyeman, Bernice; McCoy, Anne B.

    2017-06-01

    We present the results of surface hopping studies of the photodissociation of ICN^{-} and BrCN^{-} following UV and visible excitations to states that can dissociate to X^{-} + CN or X^{*} + CN^{-} (X = I or Br). Based on previous quantum dynamics studies carried out on the anions, the electronic states that are accessed by the initial UV or visible excitation were found to be coupled, and both photoproducts were observed in the dissociation process. The calculated branching ratios indicated stronger non-adiabatic interactions between the adiabatic electronic states in BrCN^{-} than in ICN^{-}. In this work, we employ Tully's surface hopping algorithm implemented in classical dynamics simulations to investigate the fragmentation processes of these anions. We calculate the branching ratios and the partitioning of the energies among the various degrees of freedom during the dynamics. The results of the surface hopping algorithm are then compared to the reported quantum dynamics results after which the surface hopping approach can then be applied to investigate the dynamics of argon clusters of the ICN^{-} and BrCN^{-}. In addition to comparison between the quantum and classical dynamics calculations, preliminary results for the semi-classical calculations on the ICN^{-} show that during the dissociation process, some of the anions live longer than others. Once the anions are solvated, we expect the presence of the argon atoms to stabilize the complexes as reported in previous work, resulting in longer lifetimes. Since experimental studies carried out on the solvated anions show the existence of recombined products even for clusters as small as ICN^{-}(Ar) or ICN^{-}(Ar)_2, when the clusters are initially excited with visible or UV radiations, respectively,^{b c} the observations of these long-lived anions provide a step towards understanding the dynamics processes that lead to the recombined products in the clusters. B. Opoku-Agyeman, A. S. Case, J. H. Lehman, W

  17. Differentially Private Trajectory Data Publication

    CERN Document Server

    Chen, Rui; Desai, Bipin C

    2011-01-01

    With the increasing prevalence of location-aware devices, trajectory data has been generated and collected in various application domains. Trajectory data carries rich information that is useful for many data analysis tasks. Yet, improper publishing and use of trajectory data could jeopardize individual privacy. However, it has been shown that existing privacy-preserving trajectory data publishing methods derived from partition-based privacy models, for example k-anonymity, are unable to provide sufficient privacy protection. In this paper, motivated by the data publishing scenario at the Societe de transport de Montreal (STM), the public transit agency in Montreal area, we study the problem of publishing trajectory data under the rigorous differential privacy model. We propose an efficient data-dependent yet differentially private sanitization algorithm, which is applicable to different types of trajectory data. The efficiency of our approach comes from adaptively narrowing down the output domain by building...

  18. Child- and parent-reported quality of life trajectories in children with epilepsy: A prospective cohort study.

    Science.gov (United States)

    Ferro, Mark A; Avery, Lisa; Fayed, Nora; Streiner, David L; Cunningham, Charles E; Boyle, Michael H; Lach, Lucyna; Glidden, Gina; Rosenbaum, Peter L; Ronen, Gabriel M

    2017-07-01

    To describe the developmental trajectories of quality of life (QoL) in a large cohort of children with epilepsy, and to assess the relative contribution of clinical, psychosocial, and sociodemographic variables on QoL trajectories. Five assessments during a 28-month prospective cohort study were used to model trajectories of QoL. Participants were recruited with their parents from six Canadian tertiary centers. A convenience sample of 506 children aged 8-14 years with epilepsy and without intellectual disability or autism spectrum disorder were enrolled. A total of 894 children were eligible and 330 refused participation. Participating children were, on average, 11.4 years of age, and 49% were female. Nearly one third (32%) had partial seizures. At baseline, 479 and 503 child- and parent-reported questionnaires were completed. In total, 354 children (74%) and 366 parents (73%) completed the 28-month follow-up. QoL was measured using the child- and parent-reported version of the Childhood Epilepsy QoL scale (CHEQOL-25). Child-reported QoL was fitted best by a six-class model and parent-reported QoL by a five-class model. In both models, trajectories remained either stable or improved over 28 months. Of these children, 62% rated their QoL as high or moderately high, defined as at least one standard deviation above the average CHEQOL-25 score. Greater family, classmate, and peer social support, fewer symptoms of child and parent depression, and higher receptive vocabulary were identified as the most robust predictors of better QoL (all p < 0.001). Most children with epilepsy and their parents reported relatively good QoL in this first joint self- and proxy-reported trajectory study. Findings confirm the heterogeneous QoL outcomes for children with epilepsy and the primary importance of psychosocial factors rather than seizure and AED-specific factors in influencing QoL. These predictors that are potentially amenable to change should now be the focus of specific

  19. Peptide inhibitor of complement C1 (PIC1, a novel suppressor of classical pathway activation: mechanistic studies and clinical potential

    Directory of Open Access Journals (Sweden)

    Julia A Sharp

    2014-08-01

    Full Text Available The classical pathway of complement plays multiple physiological roles including modulating immunological effectors initiated by adaptive immune responses as well as an essential homeostatic role in the clearance of damaged self-antigens. However, dysregulated classical pathway activation is associated with antibody-initiated, inflammatory diseases processes like cold agglutinin disease (CAD, acute intravascular hemolytic transfusion reaction (AIHTR and acute/hyperacute transplantation rejection. To date, only one putative classical pathway inhibitor, C1 esterase inhibitor (C1-INH, is currently commercially available and its only approved indication is for replacement treatment in hereditary angioedema (HAE, which is predominantly a kinin pathway disease. Given the variety of disease conditions in which the classical pathway is implicated, development of therapeutics that specifically inhibit complement initiation represents a major unmet medical need. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement. In vitro studies have demonstrated that these Peptide Inhibitors of Complement C1 (PIC1 bind to the collagen-like region of the initiator molecule of the classical pathway, C1q. PIC1 binding to C1q blocks activation of the associated serine proteases (C1s-C1r-C1r-C1s and subsequent downstream complement activation. Rational design optimization of PIC1 has resulted in the generation of a highly potent derivative of fifteen amino acids. PIC1 inhibits classical pathway mediated complement activation in ABO incompatibility in vitro as well as inhibiting classical pathway activation in vivo in rats. This review will focus on the pre-clinical development of PIC1 and discuss its potential as a therapeutic in antibody-mediated classical pathway disease, specifically AIHTR.

  20. Accuracy Combination Test of Classical and Modern Technical Analysis: A Case Study in Stock of PT Wijaya Karya Tbk

    OpenAIRE

    Agustini Hamid

    2016-01-01

    The research aimed to measure the accuracy and combination of Classic and Modern Technical Analysis. PT Wijaya Karya Tbk (WIKA)’s stock in two periods is the sample of research. Technical analysis was used to predict stock prices by observing changes in historical share price. Practically, technical analysis is divided into Classic Technical and Modern. Research was conducted by library study and using a computer software. Microsft Excel was used for the simulation and Chart Nexus for analyzi...

  1. Classics Online.

    Science.gov (United States)

    Clayman, Dee L.

    1995-01-01

    Appraises several databases devoted to classical literature. Thesaurus Linguae Graecae (TLG) contains the entire extant corpus of ancient Greek literature, including works on lexicography and historiography, extending into the 15th century. Other works awaiting completion are the Database of Classical Bibliography and a CD-ROM pictorial dictionary…

  2. Latent trajectory studies: the basics, how to interpret the results, and what to report

    Directory of Open Access Journals (Sweden)

    Rens van de Schoot

    2015-03-01

    Full Text Available Background: In statistics, tools have been developed to estimate individual change over time. Also, the existence of latent trajectories, where individuals are captured by trajectories that are unobserved (latent, can be evaluated (Muthén & Muthén, 2000. The method used to evaluate such trajectories is called Latent Growth Mixture Modeling (LGMM or Latent Class Growth Modeling (LCGA. The difference between the two models is whether variance within latent classes is allowed for (Jung & Wickrama, 2008. The default approach most often used when estimating such models begins with estimating a single cluster model, where only a single underlying group is presumed. Next, several additional models are estimated with an increasing number of clusters (latent groups or classes. For each of these models, the software is allowed to estimate all parameters without any restrictions. A final model is chosen based on model comparison tools, for example, using the BIC, the bootstrapped chi-square test, or the Lo-Mendell-Rubin test. Method: To ease the use of LGMM/LCGA step by step in this symposium (Van de Schoot, 2015 guidelines are presented which can be used for researchers applying the methods to longitudinal data, for example, the development of posttraumatic stress disorder (PTSD after trauma (Depaoli, van de Schoot, van Loey, & Sijbrandij, 2015; Galatzer-Levy, 2015. The guidelines include how to use the software Mplus (Muthén & Muthén, 1998–2012 to run the set of models needed to answer the research question: how many latent classes exist in the data? The next step described in the guidelines is how to add covariates/predictors to predict class membership using the three-step approach (Vermunt, 2010. Lastly, it described what essentials to report in the paper. Conclusions: When applying LGMM/LCGA models for the first time, the guidelines presented can be used to guide what models to run and what to report.

  3. Analysis of acute ischemic stroke presenting classic lacunar syndrome. A study by diffusion-weighted MRI

    Energy Technology Data Exchange (ETDEWEB)

    Terai, Satoshi; Ota, Kazuki; Tamaki, Kinya [Hakujyuji Hospital, Fukuoka (Japan)

    2002-03-01

    We retrospectively assessed the pathophysiological features of acute ischemic stroke presenting ''classic'' lacunar syndrome by using diffusion-weighted imaging (DWI). Subjects were 16 patients who were admitted to our hospital within 24 hours of stroke onset and underwent DWI examination on admission. These were divided into three categorical groups; pure motor hemiplegia (PMH) in 8, sensorimotor stroke (SMS) in 7, and dysarthria-clumsy hand syndrome (DCHS) in 1. The fresh responsible lesions were identified by DWI in the perforating territory in 7 patients with PMH and 7 with SMS. Four (one had two possible response lesions; pons and corona radiata) and five patients in the respective groups were diagnosed as lacunar infarction on admission (the largest dimension of the lesion measuring smaller than 15 mm). On the contralateral side to the neurological symptoms, DWI revealed high intensities in cortex, subcortical white matter, and anterior and posterior border zones in the remaining one patient with PMH and in the precentral arterial region in one with DCHS. They were diagnosed as atherothrombotic infarction resulting from the occlusion of the internal carotid artery and cerebral embolism due to atrial fibrillation, respectively. Three patients with PMH showed progressive deterioration after admission and follow-up DWI study in an acute stage revealed enlargement of heir ischemic lesions. The present study suggests that DWI is a useful imaging technique for diagnosis of clinical categories and observation for pathophsiological alteration in the acute ischemic stroke patients with ''classic'' lacunar syndrome. Our results also indicate a necessity to be aware that various types of fresh ischemic lesions other than a single lacune might possibly be developing in cases with this syndrome. (author)

  4. Quasiclassical trajectory study of fast H-atom collisions with acetylene.

    Science.gov (United States)

    Han, Yong-Chang; Sharma, Amit R; Bowman, Joel M

    2012-06-07

    Translationally hot H collisions with the acetylene are investigated using quasiclassical trajectory calculations, on a recent full-dimensional ab initio-based potential energy surface. Three outcomes are focused on: non-reactive energy transfer via prompt collisions, non-reactive energy transfer via the formation of the vinyl complex, and reactive chemical H-atom exchange, also via complex formation. The details of these outcomes are presented and correlated with the collision lifetime. Large energy transfer is found via complex formation, which can subsequently decay back to reactants, a non-reactive event, or to new products, a reactive event. For the present system, these two events are experimentally indistinguishable.

  5. Teaching the Classics: The "Origin of Species" as a Case Study

    Science.gov (United States)

    Ruse, Michael

    2013-01-01

    Many (including the author) argue that reading the classics in the field should be part of a scientist's education. However, how you read the classics can be very different depending on whether you read them as a historian or as a practicing scientist. This point will be made by comparing two readings of Charles Darwin's "Origin of…

  6. Classical integrability

    Science.gov (United States)

    Torrielli, Alessandro

    2016-08-01

    We review some essential aspects of classically integrable systems. The detailed outline of the sections consists of: 1. Introduction and motivation, with historical remarks; 2. Liouville theorem and action-angle variables, with examples (harmonic oscillator, Kepler problem); 3. Algebraic tools: Lax pairs, monodromy and transfer matrices, classical r-matrices and exchange relations, non-ultralocal Poisson brackets, with examples (non-linear Schrödinger model, principal chiral field); 4. Features of classical r-matrices: Belavin-Drinfeld theorems, analyticity properties, and lift of the classical structures to quantum groups; 5. Classical inverse scattering method to solve integrable differential equations: soliton solutions, spectral properties and the Gel’fand-Levitan-Marchenko equation, with examples (KdV equation, Sine-Gordon model). Prepared for the Durham Young Researchers Integrability School, organised by the GATIS network. This is part of a collection of lecture notes.

  7. Do Stress Trajectories Predict Mortality in Older Men? Longitudinal Findings from the VA Normative Aging Study

    Directory of Open Access Journals (Sweden)

    Carolyn M. Aldwin

    2011-01-01

    Full Text Available We examined long-term patterns of stressful life events (SLE and their impact on mortality contrasting two theoretical models: allostatic load (linear relationship and hormesis (inverted U relationship in 1443 NAS men (aged 41–87 in 1985; M = 60.30, SD = 7.3 with at least two reports of SLEs over 18 years (total observations = 7,634. Using a zero-inflated Poisson growth mixture model, we identified four patterns of SLE trajectories, three showing linear decreases over time with low, medium, and high intercepts, respectively, and one an inverted U, peaking at age 70. Repeating the analysis omitting two health-related SLEs yielded only the first three linear patterns. Compared to the low-stress group, both the moderate and the high-stress groups showed excess mortality, controlling for demographics and health behavior habits, HRs = 1.42 and 1.37, ps <.01 and <.05. The relationship between stress trajectories and mortality was complex and not easily explained by either theoretical model.

  8. Qualitative to quantitative: linked trajectory of method triangulation in a study on HIV/AIDS in Goa, India.

    Science.gov (United States)

    Bailey, Ajay; Hutter, Inge

    2008-10-01

    With 3.1 million people estimated to be living with HIV/AIDS in India and 39.5 million people globally, the epidemic has posed academics the challenge of identifying behaviours and their underlying beliefs in the effort to reduce the risk of HIV transmission. The Health Belief Model (HBM) is frequently used to identify risk behaviours and adherence behaviour in the field of HIV/AIDS. Risk behaviour studies that apply HBM have been largely quantitative and use of qualitative methodology is rare. The marriage of qualitative and quantitative methods has never been easy. The challenge is in triangulating the methods. Method triangulation has been largely used to combine insights from the qualitative and quantitative methods but not to link both the methods. In this paper we suggest a linked trajectory of method triangulation (LTMT). The linked trajectory aims to first gather individual level information through in-depth interviews and then to present the information as vignettes in focus group discussions. We thus validate information obtained from in-depth interviews and gather emic concepts that arise from the interaction. We thus capture both the interpretation and the interaction angles of the qualitative method. Further, using the qualitative information gained, a survey is designed. In doing so, the survey questions are grounded and contextualized. We employed this linked trajectory of method triangulation in a study on the risk assessment of HIV/AIDS among migrant and mobile men. Fieldwork was carried out in Goa, India. Data come from two waves of studies, first an explorative qualitative study (2003), second a larger study (2004-2005), including in-depth interviews (25), focus group discussions (21) and a survey (n=1259). By employing the qualitative to quantitative LTMT we can not only contextualize the existing concepts of the HBM, but also validate new concepts and identify new risk groups.

  9. Classical approach in quantum physics

    CERN Document Server

    Solov'ev, Evgeni A

    2010-01-01

    The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom recently discovered with the help of Poincar$\\acute{\\mathrm{e}}$ section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treating as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semicla...

  10. Radarsat observations and forecasting of oil slick trajectory movements

    Institute of Scientific and Technical Information of China (English)

    Maged Marghany

    2004-01-01

    RADARSAT data have a potential role for coastal pollution monitoring. This study presents a new approach to detect and forecast oil slick trajectory movements. The oil slick trajectory movements is based on the tidal current effects and Fay's algorithm for oil slick spreading mechanisms. The oil spill trajectory model contains the integration between Doppler frequency shift model and Lagrangian model. Doppler frequency shift model implemented to simulate tidal current pattern from RADARSAT data while the Lagrangian model used to predict oil spill spreading pattern. The classical Fay's algorithm was implemented with the two models to simulate the oil spill trajectory movements.The study shows that the slick lengths are effected by tidal current V component with maximum velocity of 1.4 m/s. This indicates thatoil slick trajectory path is moved towards the north direction. The oil slick parcels are accumulated along the coastline after 48 h. Theanalysis indicated that tidal current V components were the dominant forcing for oil slick spreading.

  11. STUDY OF SEASONAL TREND-PROCESS WITH THE METHOD OF CLASSICAL STATISTICS

    Directory of Open Access Journals (Sweden)

    Kymratova A. M.

    2014-11-01

    Full Text Available This work is devoted to the methods of multicriteria optimization and classical statistics of obtaining pre-estimated information for time series that have long-term memory, which is why their levels do not satisfy the independence property, and therefore the classical prediction methods may be inadequate. The developed methods of obtaining such information are based on classical statistics methods such as mathematical statistics, multicriteria optimization and extreme value theory. The effectiveness of the proposed approach has been demonstrated on the example of specific time series of volumes of mountain rivers

  12. Chronic exposure of grandparents to poverty and body mass index trajectories of grandchildren: a prospective intergenerational study.

    Science.gov (United States)

    Li, Miao

    2015-02-01

    In this study, I used the growth curve model to examine the association between grandparents' (first generation (G1)) life-course exposure to chronic poverty and grandchildren's (third generation (G3)) body mass index (BMI; weight (kg)/height (m)(2)) growth trajectories. This association was estimated separately for male and female grandchildren. Analyses were based on prospective data from a US longitudinal survey, the Panel Study of Income Dynamics (1968-2011), and 2 of its supplemental studies: the Child Development Supplement (1997-2011) and the Transition into Adulthood Study (1997-2011). A prospectively enrolled nationally representative cohort of 2,613 G3 youth (1,323 male, 1,290 female) sampled in the 2 supplemental studies was linked to 1,719 grandparents from the Panel Study of Income Dynamics core sample. Chronic exposure to poverty among grandparents was prospectively ascertained annually over a 30-year period prior to the collection of data on grandchildren. Findings suggested that grandparents' chronic poverty exposure was positively associated with the slope of the BMI trajectory among granddaughters (β = 0.10, 95% confidence interval: 0.03, 0.17) but not among grandsons (β = 0.02, 95% confidence interval: -0.04, 0.08). The association between grandparents' chronic poverty exposure and granddaughters' BMI growth slope remained even after controlling for parental (second generation (G2)) socioeconomic status and BMI.

  13. Classic Galactosemia: Study on the Late Prenatal Development of GALT Specific Activity in a Sheep Model.

    Science.gov (United States)

    Coelho, Ana I; Bierau, Jörgen; Lindhout, Martijn; Achten, Jelle; Kramer, Boris W; Rubio-Gozalbo, M Estela

    2017-09-01

    Classic galactosemia results from deficient activity of galactose-1-phosphate uridylyltransferase (GALT), a key enzyme of galactose metabolism. Despite early diagnosis and early postnatal therapeutic intervention, patients still develop neurologic and fertility impairments. Prenatal developmental toxicity has been hypothesized as a determinant factor of disease. In order to shed light on the importance of prenatal GALT activity, several studies have examined GALT activity throughout development. GALT was shown to increase with gestational age in 7-28 weeks human fetuses; later stages were not investigated. Prenatal studies in animals focused exclusively on brain and hepatic GALT activity. In this study, we aim to examine GALT specific activity in late prenatal and adult stages, using a sheep model. Galactosemia acute target-organs-liver, small intestine and kidney-had the highest late prenatal activity, whereas the chronic target-organs-brain and ovary-did not exhibit a noticeable pre- or postnatal different activity compared with nontarget organs. This is the first study on GALT specific activity in the late prenatal stage for a wide variety of organs. Our findings suggest that GALT activity cannot be the sole pathogenic factor accounting for galactosemia long-term complications, and that some organs/cells might have a greater susceptibility to galactose toxicity. Anat Rec, 300:1570-1575, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Segmenting Trajectories by Movement States

    NARCIS (Netherlands)

    Buchin, M.; Kruckenberg, H.; Kölzsch, A.; Timpf, S.; Laube, P.

    2013-01-01

    Dividing movement trajectories according to different movement states of animals has become a challenge in movement ecology, as well as in algorithm development. In this study, we revisit and extend a framework for trajectory segmentation based on spatio-temporal criteria for this purpose. We adapt

  15. PUNARNAVA MANDUR: TOXICITY STUDY OF CLASSICAL AYURVEDIC FORMULATION IN WISTAR RATS

    Directory of Open Access Journals (Sweden)

    P. S. Jamadagni

    2013-06-01

    Full Text Available Punarnava Mandur is an iron containing classical Ayurvedic formulation which was studied for repeated dose oral toxicity study in Wistar rats for 90 days. Total 48 Wistar rats (24 male and 24 female were selected based on the body weight and were randomly distributed into four groups followed by administration of Punarnava Mandur at the dose of 0, 90, 450, 900 mg/kg body weight for 90 consecutive days. Body weight, Weekly Feed and Water consumption, Clinical Chemistry, Hematology, Differential leukocyte Count, Reticulocyte count and Organ weights were recorded and analyzed statistically. At termination, rats were sacrificed, examined for gross pathological changes, organs were collected, weighed and processed for histopathological evaluation. There was no effect on body weights and feed consumption, no abnormal findings in the histopathological evaluation of high dose group animals but there was significant increase in weight of liver in females of high dose group as compared to control. Hence, the dose level 450 mg/kg of Punarnava Mandur was found as NOAEL (No Observable Adverse Effect Level. However, the NOEL (No Observed Effect Level could not be established. It was suggested to carry out a toxicity study at possible higher doses so as to establish target organ of toxicity.

  16. Social conformity and autism spectrum disorder: a child-friendly take on a classic study.

    Science.gov (United States)

    Yafai, Abdul-Fattah; Verrier, Diarmuid; Reidy, Lisa

    2014-11-01

    Perhaps surprisingly, given the importance of conformity as a theoretical construct in social psychology and the profound implications autism has for social function, little research has been done on whether autism is associated with the propensity to conform to a social majority. This study is a modern, child-friendly implementation of the classic Asch conformity studies. The performance of 15 children with autism was compared to that of 15 typically developing children on a line judgement task. Children were matched for age, gender and numeracy and literacy ability. In each trial, the child had to say which of three lines a comparison line matched in length. On some trials, children were misled as to what most people thought the answer was. Children with autism were much less likely to conform in the misleading condition than typically developing children. This finding was replicated using a continuous measure of autism traits, the Autism Quotient questionnaire, which showed that autism traits negatively correlated with likelihood to conform in the typically developing group. This study demonstrates the resistance of children with autism to social pressure.

  17. Numerical Study on the Particle Trajectory Tracking in a Micro-UV Bio-Fluorescence Sensor.

    Science.gov (United States)

    Byeon, Sun-Seok; Cho, Moon-Young; Lee, Jong-Chul; Kim, Youn-Jea

    2015-03-01

    A micro-UV bio-fluorescence sensor was developed to detect primary biological aerosols including bacteria, bacterial spores, fungal spores, pollens, viruses, algae, etc. In order to effectively detect the bio-particles in a micro-UV bio-fluorescence sensor, numerical calculations were performed to adjust for appropriate flow conditions of the sensor by regulating the sample aerosols and sheath flow. In particular, a CFD-based model of hydrodynamic processes was developed by computing the trajectory of particles using commercially available ANSYS CFX-14 software and the Lagrangian tracking model. The established model was evaluated with regard to the variation of sheath flow rate and particle size. Results showed that the sheath flow was changed rapidly at the end of nozzle tip, but the sample particles moved near the center of aerosol jet for aerodynamic focusing with little deviation from the axis.

  18. Forecasting Public Transit Use by Crowdsensing and Semantic Trajectory Mining: Case Studies

    Directory of Open Access Journals (Sweden)

    Ningyu Zhang

    2016-09-01

    Full Text Available With the growing development of smart cities, public transit forecasting has begun to attract significant attention. In this paper, we propose an approach for forecasting passenger boarding choices and public transit passenger flow. Our prediction model is based on mining common user behaviors for semantic trajectories and enriching features using knowledge from geographic and weather data. All the experimental data comes from the Ridge Nantong Limited bus company and Alibaba platform which is also open to the public. We evaluate our approach using various data sources, including point of interest (POI, weather condition, and public bus information in Guangzhou to demonstrate its effectiveness. Experimental results show that our proposal performs better than baselines in the prediction of passenger boarding choices and public transit passenger flow.

  19. Successful Aging: Multiple Trajectories and Population Heterogeneity

    OpenAIRE

    Fengyan Tang

    2014-01-01

    Following Rowe and Kahn¡¯s successful aging model, this study identified successful aging as a distinctive aging trajectory and examined gender differences in the aging process. Using the Health and Retirement Study data (2000-2008), this study applied group-based trajectory analysis to identify multiple aging trajectories in a sample of older Americans aged 65 and over (N=9,226). Six dimensions were analyzed in the multi-trajectory model: chronic disease, physical functional limitation, disa...

  20. Differential phonological awareness skills in children with classic galactosemia: a descriptive study of four cases.

    Science.gov (United States)

    Lewis, Fiona M; Coman, David J; Syrmis, Maryann; Kilcoyne, Sarah; Murdoch, Bruce E

    2013-01-01

    Educational achievement, which for individuals with the metabolic disorder classic galactosemia (GAL) is significantly lower than in the wider population, correlates with self-reported quality of life. Phonological awareness skills underpin the development of literacy, and although literacy is a key contributor to successful academic outcomes, no study to date has investigated phonological awareness skills in children with GAL. This study investigated phonological awareness (PA) in four school-aged children with the disorder, two of whom were siblings. Age range for the children was 7 years 7 months to 9 years 2 months. Each child was assessed with the Phonological Awareness criterion-referenced subtest from the Clinical Evaluation of Language Fundamentals-Fourth Edition. Included in the data for analysis was each child's performance measures obtained from their most recent assessment of cognitive and lexical development. A number of descriptive analyses were undertaken on the data. One child, who met her age criterion for PA, had cognitive and lexical development skills in the average range. The remaining three children failed to meet their age criteria. Although these three children presented with clinically similar cognitive and lexical development skills, disparate PA skills were identified. The PA skills of one of the sibling pair were notably more advanced than his older sibling. The limitations of relying on behavioural test results in children with GAL to predict those most at risk of reduced skill development are discussed in terms future research directions.

  1. CLASSICAL AND MOLECULAR CYTOGENETIC STUDIES FOR BREEDING AND SELECTION OF TULIPS

    Directory of Open Access Journals (Sweden)

    Aurel Popescu

    2012-12-01

    Full Text Available Due to their extreme popularity as fresh cut flowers and garden plants, and being used extensively for landscaping, tulips undergone a continuous process of selective breeding. For almost nine decades, classical cytogenetic studies, mainly the chromosome counts, have been an important part in the breeding programme for polyploid tulips. The efficiency of breeding is greatly aided by a thorough knowledge of the occurrence of polyploidy in the plant material. While the traditional cytogenetic approaches are still highly useful in selecting polyploids and aneuploids arising from crosses involving (most often parents of different ploidy or from the material subjected to ploidy manipulation, the new strategies for inducing polyploidy in tulips, either in vivo or in vitro, and advances in molecular cytogenetics are expected to allow a significant increase in breeding efficiency. Together with the shortening of breeding cycle, major genetic improvements could be made for specific traits. In this we review the development of cytogenetic studies in tulips, and the most relevant achievements so far, providing an overview of what we consider to be valuable tools for the processes of selective breeding .

  2. Bayesian hierarchical piecewise regression models: a tool to detect trajectory divergence between groups in long-term observational studies.

    Science.gov (United States)

    Buscot, Marie-Jeanne; Wotherspoon, Simon S; Magnussen, Costan G; Juonala, Markus; Sabin, Matthew A; Burgner, David P; Lehtimäki, Terho; Viikari, Jorma S A; Hutri-Kähönen, Nina; Raitakari, Olli T; Thomson, Russell J

    2017-06-06

    Bayesian hierarchical piecewise regression (BHPR) modeling has not been previously formulated to detect and characterise the mechanism of trajectory divergence between groups of participants that have longitudinal responses with distinct developmental phases. These models are useful when participants in a prospective cohort study are grouped according to a distal dichotomous health outcome. Indeed, a refined understanding of how deleterious risk factor profiles develop across the life-course may help inform early-life interventions. Previous techniques to determine between-group differences in risk factors at each age may result in biased estimate of the age at divergence. We demonstrate the use of Bayesian hierarchical piecewise regression (BHPR) to generate a point estimate and credible interval for the age at which trajectories diverge between groups for continuous outcome measures that exhibit non-linear within-person response profiles over time. We illustrate our approach by modeling the divergence in childhood-to-adulthood body mass index (BMI) trajectories between two groups of adults with/without type 2 diabetes mellitus (T2DM) in the Cardiovascular Risk in Young Finns Study (YFS). Using the proposed BHPR approach, we estimated the BMI profiles of participants with T2DM diverged from healthy participants at age 16 years for males (95% credible interval (CI):13.5-18 years) and 21 years for females (95% CI: 19.5-23 years). These data suggest that a critical window for weight management intervention in preventing T2DM might exist before the age when BMI growth rate is naturally expected to decrease. Simulation showed that when using pairwise comparison of least-square means from categorical mixed models, smaller sample sizes tended to conclude a later age of divergence. In contrast, the point estimate of the divergence time is not biased by sample size when using the proposed BHPR method. BHPR is a powerful analytic tool to model long-term non

  3. Trajectories of delinquency and parenting styles

    NARCIS (Netherlands)

    Hoeve, M.; Blokland, A.; Dubas, J.S.; Loeber, R.; Gerris, J.R.M.; Laan, P.H. van der

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  4. Trajectories of Delinquency and Parenting Styles

    NARCIS (Netherlands)

    Hoeve, M.; Blokland, A.; Dubas, J.S.; Loeber, R.; Gerris, J.R.M.; Laan, P.H. van der

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  5. Trajectories of Delinquency and Parenting Styles

    NARCIS (Netherlands)

    Hoeve, M.; Blokland, A.; Dubas, J.S.; Loeber, R.; Gerris, J.R.M.; Laan, P.H. van der

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  6. Trajectories of delinquency and parenting styles

    NARCIS (Netherlands)

    M. Hoeve; A. van Blokland; J.S. Dubas; R Loeber; J.R.M. Gerris; P.H. van der Laan

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering

  7. Theoretical Studies in Chemical Kinetics - Annual Report, 1970.

    Science.gov (United States)

    Karplus, Martin

    1970-10-01

    The research performed includes (a) Alkali-Halide, Alkali-Halide (MX, M’X’) Exchange Reactions; (b) Inversion Problem; (c) Quantum Mechanics of Scattering Processes, (d) Transition State Analysis of Classical Trajectories, (e) Differential Cross Sections from Classical Trajectories; and (f) Other Studies.

  8. Quantum-classical correspondence of a field induced KAM-type transition: A QTM approach

    Indian Academy of Sciences (India)

    P K Chattaraj; S Sengupta; S Giri

    2008-01-01

    A transition from regular to chaotic behaviour in the dynamics of a classical Henon-Heiles oscillator in the presence of an external field is shown to have a similar quantum signature when studied using the pertaining phase portraits and the associated Kolmogorov-Sinai-Lyapunov entropies obtained through the corresponding Bohmian trajectories.

  9. Sexual function in adult patients with classic bladder exstrophy: A multicenter study.

    Science.gov (United States)

    Park, Weon; Zwink, Nadine; Rösch, Wolfgang H; Schmiedeke, Eberhard; Stein, Raimund; Schmidt, Dominik; Noeker, Meinolf; Jenetzky, Ekkehart; Reutter, Heiko; Ebert, Anne-Karoline

    2015-06-01

    The bladder exstrophy-epispadias complex (BEEC) comprises a spectrum of congenital anomalies that represents the severe end of urorectal malformations, and has a profound impact on continence as well as sexual and renal functions. The relation between severity of BEEC and its associated functional impairments, on one hand, and the resulting restrictions in quality of life and potential psychopathology determine the patients' outcome. It is important for improving further outcome to identify BEEC-related sources of distress in the long term. Genital function and sexuality becomes an important issue for adolescent and adult BEEC individuals. Hence, the present study focused on sexual function and psychological adaption in patients with BEEC. In a multicenter study 52 patients (13 females, 39 males) with classic bladder exstrophy (BE) with their bladders in use were assessed by a self-developed questionnaire about sexual function, and psychosexual and psychosocial outcome. The patients were born between 1948 and 1994 (median age 31 years). Twelve of 13 (92%) females and 25 of 39 (64%) males with classic BE had answered the questions on sexual function. Of these, 50% females and 92% males answered that they masturbated. Females had sexual intercourse more frequently. Six (50%) females affirmed dyspareunia whereas only two (8%) males reported pain during erection. Eight (67%) females specified having orgasms. Eighteen (72%) males were able to ejaculate. Two males and none of the females lived in a committed partnership (Figure). Two (15%) females and 13 (33%) males answered all psychosocial questions. The majority of these patients had concerns about satisfactory sexuality and lasting, happy partnerships. A minority of patients of both sexes were willing to answer psychosocial questions. Sexual activity and relationships of many adult BE patients seems to be impaired. Not surprisingly, sexual activity and awareness were different in males and females even in a multi

  10. A Comprehensive Study of Hydrogen Adsorbing to Amorphous Water ice: Defining Adsorption in Classical Molecular Dynamics

    Science.gov (United States)

    Dupuy, John L.; Lewis, Steven P.; Stancil, P. C.

    2016-11-01

    Gas-grain and gas-phase reactions dominate the formation of molecules in the interstellar medium (ISM). Gas-grain reactions require a substrate (e.g., a dust or ice grain) on which the reaction is able to occur. The formation of molecular hydrogen (H2) in the ISM is the prototypical example of a gas-grain reaction. In these reactions, an atom of hydrogen will strike a surface, stick to it, and diffuse across it. When it encounters another adsorbed hydrogen atom, the two can react to form molecular hydrogen and then be ejected from the surface by the energy released in the reaction. We perform in-depth classical molecular dynamics simulations of hydrogen atoms interacting with an amorphous water-ice surface. This study focuses on the first step in the formation process; the sticking of the hydrogen atom to the substrate. We find that careful attention must be paid in dealing with the ambiguities in defining a sticking event. The technical definition of a sticking event will affect the computed sticking probabilities and coefficients. Here, using our new definition of a sticking event, we report sticking probabilities and sticking coefficients for nine different incident kinetic energies of hydrogen atoms [5-400 K] across seven different temperatures of dust grains [10-70 K]. We find that probabilities and coefficients vary both as a function of grain temperature and incident kinetic energy over the range of 0.99-0.22.

  11. Prognostic significance of new immunohistochemical markers in refractory classical Hodgkin lymphoma: a study of 59 cases.

    Directory of Open Access Journals (Sweden)

    Danielle Canioni

    Full Text Available Although most classical Hodgkin lymphoma patients are cured, a significant minority fail after primary therapy and may die as result of their disease. To date, there is no consensus on biological markers that add value to usual parameters (which comprise the International Prognostic Score used at diagnosis to predict outcome. We evaluated 59 patients (18 with primary refractory or early relapse disease and 41 responders for bcl2, Ki67, CD20, TiA1 and c-kit expression by semi-quantitative immunohistochemical study and correlated the results with the response to treatment.The results showed that expression of bcl2 and CD20 in Hodgkin and Reed Sternberg cells, and expression of TiA1 in micro-environmental lymphocytes, and c-kit positive mast cells in microenvironment, were independent prognostic markers. These novel cHL markers could be used in association with clinical parameters to identify newly diagnosed patients with favorable or unfavorable prognosis and to better tailor treatment for different risk groups.

  12. Review of Digital Research in the Study of Classical Antiquity [Book

    Directory of Open Access Journals (Sweden)

    Adam Rabinowitz

    2011-07-01

    Full Text Available It is often stated that trying to deal with information on the internet is like drinking from a firehose. But trying to put together a book about the current state of digital anything must be rather more like trying to paint a landscape from the window of a moving train. By the time the painting is complete, the scenery has changed dramatically. This puts books on digital approaches to academic disciplines in an interesting position: by the time a volume makes it into the hands of its readers, it is already a historical document as well as a scholarly work. The editors of Digital Research in the Study of Classical Antiquity are very aware of this: as they state, the book seeks "to create a snapshot of the research activities of Digital Classicist members as represented by a selection of the papers given at our Summer seminars and conference panels in one particular year, 2007" (p10. When one considers that the printed volume went to press in 2010, and is being reviewed in 2011, this means that almost four years—a digital eternity—have passed since most of the papers were first composed. I think, therefore, it will be most useful to discuss Digital Research from two perspectives: first, in terms of its scholarly contribution, and second, in terms of what the framing of this work and the identity of its contributors tell us about a particular moment in the history of the field of 'digital humanities'.

  13. The potential of antiviral agents to control classical swine fever: a modelling study.

    Science.gov (United States)

    Backer, Jantien A; Vrancken, Robert; Neyts, Johan; Goris, Nesya

    2013-09-01

    Classical swine fever (CSF) represents a continuous threat to pig populations that are free of disease without vaccination. When CSF virus is introduced, the minimal control strategy imposed by the EU is often insufficient to mitigate the epidemic. Additional measures such as preemptive culling encounter ethical objections, whereas emergency vaccination leads to prolonged export restrictions. Antiviral agents, however, provide instantaneous protection without inducing an antibody response. The use of antiviral agents to contain CSF epidemics is studied with a model describing within- and between-herd virus transmission. Epidemics are simulated in a densely populated livestock area in The Netherlands, with farms of varying sizes and pig types (finishers, piglets and sows). Our results show that vaccination and/or antiviral treatment in a 2 km radius around an infected herd is more effective than preemptive culling in a 1 km radius. However, the instantaneous but temporary protection provided by antiviral treatment is slightly less effective than the delayed but long-lasting protection offered by vaccination. Therefore, the most effective control strategy is to vaccinate animals when allowed (finishers and piglets) and to treat with antiviral agents when vaccination is prohibited (sows). As independent control measure, antiviral treatment in a 1 km radius presents an elevated risk of epidemics running out of control. A 2 km control radius largely eliminates this risk.

  14. Childhood chronic-kidney-disease: a longitudinal-qualitative study of families learning to share management early in the trajectory.

    Science.gov (United States)

    Swallow, Veronica; Lambert, Heather; Clarke, Charlotte; Campbell, Steve; Jacoby, Ann

    2008-11-01

    To explore the ways families learn to share management during the early stages of childhood chronic-kidney-disease. This longitudinal, descriptive study based on the tenets of grounded theory, aimed to derive meaning about family-professional interactions during shared management. Data were obtained from six newly referred families, four renal nurses, four paediatric nephrologists and one dietician through: 36 semi-structured interviews, 21 case-note reviews and four child/parent learning diaries. Three learning stages were identified: dependent (families' understanding was superficial, they lacked underlying knowledge and were totally reliant on professional guidance); co-dependent (families engaged competently in management but still required extensive guidance); independent (families communicated effectively with staff and competently adjusted management within professionally defined parameters). Five families actively shared management from early in the trajectory and progressed to independent learning when, by mutual agreement, professional input to management gradually decreased. The remaining family adopted a passive approach to management, did not progress to independent learning and remained reliant on professional input. Families in this study demonstrated three learning stages in becoming competent at management. Future research is needed to investigate the ways professionals promote family competence early in the trajectory and the factors that can facilitate or hinder families' progression to independent learning.

  15. Influence of psychosocial risk factors on the trajectory of mental health problems from childhood to adolescence: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Fatori Daniel

    2013-01-01

    Full Text Available Abstract Background Longitudinal epidemiological studies involving child/adolescent mental health problems are scarce in developing countries, particularly in regions characterized by adverse living conditions. We examined the influence of psychosocial factors on the trajectory of child/adolescent mental health problems (CAMHP over time. Methods A population-based sample of 6- to 13-year-olds with CAMHP was followed-up from 2002–2003 (Time 1/T1 to 2007–2008 (Time 2/T2, with 86 out of 124 eligible children/adolescents at T1 being reassessed at T2 (sample loss: 30.6%. Outcome: CAMHP at T2 according to the Child Behavior Checklist/CBCL’s total problem scale. Psychosocial factors: T1 variables (child/adolescent’s age, family socioeconomic status; trajectory of variables from T1 to T2 (child/adolescent exposure to severe physical punishment, mother exposure to severe physical marital violence, maternal anxiety/depression; and T2 variables (maternal education, child/adolescent’s social support and pro-social activities. Results Multivariate analysis identified two risk factors for child/adolescent MHP at T2: aggravation of child/adolescent physical punishment and aggravation of maternal anxiety/depression. Conclusions The current study shows the importance of considering child/adolescent physical punishment and maternal anxiety/depression in intervention models and mental health care policies.

  16. Trajectory grouping structure

    Directory of Open Access Journals (Sweden)

    Maike Buchin

    2015-03-01

    Full Text Available The collective motion of a set of moving entities like people, birds, or other animals, is characterized by groups arising, merging, splitting, and ending. Given the trajectories of these entities, we define and model a structure that captures all of such changes using the Reeb graph, a concept from topology. The trajectory grouping structure has three natural parameters that allow more global views of the data in group size, group duration, and entity inter-distance. We prove complexity bounds on the maximum number of maximal groups that can be present, and give algorithms to compute the grouping structure efficiently. We also study how the trajectory grouping structure can be made robust, that is, how brief interruptions of groups can be disregarded in the global structure, adding a notion of persistence to the structure. Furthermore, we showcase the results of experiments using data generated by the NetLogo flocking model and from the Starkey project. The Starkey data describe the movement of elk, deer, and cattle. Although there is no ground truth for the grouping structure in this data, the experiments show that the trajectory grouping structure is plausible and has the desired effects when changing the essential parameters. Our research provides the first complete study of trajectory group evolvement, including combinatorial,algorithmic, and experimental results.

  17. Grey matter density decreases as well as increases in patients with classic galactosemia : a voxel-based morphometry study

    NARCIS (Netherlands)

    Timmers, Inge; van der Korput, Lisanne D; Jansma, Bernadette M; Rubio-Gozalbo, M Estela

    2016-01-01

    Brain impairments have been observed in patients with classic galactosemia, an inherited metabolic disorder resulting in a particular neuro-cognitive profile. Neuroimaging studies showed abnormalities such as diffuse white mater (WM) abnormalities and grey matter (GM) atrophy. Our current study anal

  18. Soccer ball lift coefficients via trajectory analysis

    Energy Technology Data Exchange (ETDEWEB)

    Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: goff@lynchburg.ed [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2010-07-15

    We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

  19. Classical conditioning for preserving the effects of short melatonin treatment in children with delayed sleep: a pilot study

    Science.gov (United States)

    van Maanen, Annette; Meijer, Anne Marie; Smits, Marcel G; Oort, Frans J

    2017-01-01

    Melatonin treatment is effective in treating sleep onset problems in children with delayed melatonin onset, but effects usually disappear when treatment is discontinued. In this pilot study, we investigated whether classical conditioning might help in preserving treatment effects of melatonin in children with sleep onset problems, with and without comorbid attention deficit hyperactivity disorder (ADHD) or autism. After a baseline week, 16 children (mean age: 9.92 years, 31% ADHD/autism) received melatonin treatment for 3 weeks and then gradually discontinued the treatment. Classical conditioning was applied by having children drink organic lemonade while taking melatonin and by using a dim red light lamp that was turned on when children went to bed. Results were compared with a group of 41 children (mean age: 9.43 years, 34% ADHD/autism) who received melatonin without classical conditioning. Melatonin treatment was effective in advancing dim light melatonin onset and reducing sleep onset problems, and positive effects were found on health and behavior problems. After stopping melatonin, sleep returned to baseline levels. We found that for children without comorbidity in the experimental group, sleep latency and sleep start delayed less in the stop week, which suggests an effect of classical conditioning. However, classical conditioning seems counterproductive in children with ADHD or autism. Further research is needed to establish these results and to examine other ways to preserve melatonin treatment effects, for example, by applying morning light.

  20. Risk perception and the economic crisis: a longitudinal study of the trajectory of perceived risk.

    Science.gov (United States)

    Burns, William J; Peters, Ellen; Slovic, Paul

    2012-04-01

    We conducted a longitudinal survey of public response to the economic crisis to understand the trajectory of risk perception amidst an ongoing crisis. A nation-wide panel responded to seven surveys beginning in late September 2008 at the peak of the crisis and concluded in October 2009. At least 600 respondents participated in each survey, with 413 completing all seven surveys. Our online survey focused on perceptions of risk (savings, investments, retirement, job), negative emotions toward the financial crisis (sadness, anxiety, fear, anger, worry, stress), confidence in national leaders to manage the crisis (President Obama, Congress, Treasury Secretary, business leaders), and belief in one's ability to realize personal objectives despite the crisis. We employed latent growth curve modeling to analyze change in risk perception throughout the crisis. Our results suggest that, in general, people's perceptions of risk appear to decrease most rapidly during the initial phase of a crisis and then begin to level off. Negative emotion about the crisis was the most predictive of increased risk perception, supporting the notion of risk as feelings. Belief in one's ability to realize personal objectives was also predictive. Confidence in national leaders, however, was not predictive of perceived risk. Finally, our results demonstrate that groups may experience a crisis differently depending on a combination of personal characteristics such as gender, income, numeracy, and political attitude. Risk management and communication should work in sync with these mechanisms and differences across groups.

  1. Studying the effects of classic hallucinogens in the treatment of alcoholism: rationale, methodology, and current research with psilocybin.

    Science.gov (United States)

    Bogenschutz, Michael P

    2013-03-01

    Recent developments in the study of classic hallucinogens, combined with a re-appraisal of the older literature, have led to a renewal of interest in possible therapeutic applications for these drugs, notably their application in the treatment of addictions. This article will first provide a brief review of the research literature providing direct and indirect support for the possible therapeutic effects of classic hallucinogens such as psilocybin and lysergic acid diethylamide (LSD) in the treatment of addictions. Having provided a rationale for clinical investigation in this area, we discuss design issues in clinical trials using classic hallucinogens, some of which are unique to this class of drug. We then discuss the current status of this field of research and design considerations in future randomized trials.

  2. Employment trajectory as determinant of change in health-related lifestyle: the prospective HeSSup study

    National Research Council Canada - National Science Library

    Virtanen, Pekka; Vahtera, Jussi; Broms, Ulla; Sillanmäki, Lauri; Kivimäki, Mika; Koskenvuo, Markku

    2008-01-01

    .... Associations of the employment trajectories with changes in smoking, alcohol drinking, body weight, physical activity and sleep duration were assessed with analysis of variance for repeated measures...

  3. Classical Mechanics

    OpenAIRE

    Gallavotti, Giovanni

    2012-01-01

    This is the English version of a friendly graduate course on Classical Mechanics, containing about 80% of the material I covered during the January-June 1999 semester at IFUG in the Mexican city of Leon. For the Spanish version, see physics/9906066

  4. Classical Study of Transfer and Ionization in A2++He Collisions

    Institute of Scientific and Technical Information of China (English)

    DING Bao-Wei; CHEN Xi-Meng; FU Hong-Bin; LIU Zhao-Yuan

    2008-01-01

    A simple model for the direct ionization and transfer ionization probabilities in A2++He collisions in a wide projectile energy range is proposed based on the Bohr-Lindhard model and the classical statistical model.The calculated cross sections are in satisfactory agreement with the experimental data available.

  5. Classical swine fever (CSF) marker vaccine - Trial I. Challenge studies in weaner pigs

    DEFF Research Database (Denmark)

    Uttenthal, Åse; Le Potier, M.F.; Romero, L.

    2001-01-01

    , -10 or -7, and subsequently challenged at day 0. The challenge virus was CSFV 277, originating from a recent outbreak of classical swine fever (CSF) in Germany. In all groups, only 5 out of 10 pigs were challenged; the remaining 5 pigs served as vaccinated contact controls. Also, three control groups...

  6. A Brief Study of Western Filial Piety--From the Perspective of Classical Philosophy

    Institute of Scientific and Technical Information of China (English)

    莫奕锟

    2014-01-01

    Different from Chinese filial piety, Western filial piety hasn’t developed into an independent system, only with the meaning of filial piety infiltrating into the religious belief and religious culture. In this sense, Western filial piety bears a strong sense of logical thinking and religious belief, which has much to do with Western classical philosophy.

  7. A Brief Study of Western Filial Piety——From the Perspective of Classical Philosophy

    Institute of Scientific and Technical Information of China (English)

    莫奕锟

    2014-01-01

    Different from Chinese filial piety, Western filial piety hasn’t developed into an independent system, only with the meaning of filial piety infiltrating into the religious belief and religious culture. In this sense, Western filial piety bears a strong sense of logical thinking and religious belief, which has much to do with Western classical philosophy.

  8. Studies in Early Infant Learning: Classical Conditioning of the Neonatal Heart Rate

    Science.gov (United States)

    Crowell, David H.; And Others

    1976-01-01

    In three experiments, it was demonstrated that human newborn heart rate level can be reliably modified through classical conditioning procedures. Findings support the idea that early learning may occur under a variety of conditions and different theories may account for the results. (Author/SB)

  9. Examining the Construction Process: A Study of Changes in Level 10 Students' Understanding of Classical Mechanics.

    Science.gov (United States)

    Shymansky, James A.; And Others

    1997-01-01

    Explores students' conceptual understanding and conceptual growth in classical mechanics in the natural context of a grade 10 science classroom. Findings indicate that students' knowledge structures remained stable across the 10 weeks and remained unchanged 4 weeks after instruction ceased. Contains 30 references. (Author/JRH)

  10. The Bread and Butter of Classical Organizational Approaches: The Time-and-Motion Study

    Science.gov (United States)

    Peterson, Dan W.

    2007-01-01

    The thought of learning about the principles of classical management and the machine metaphor of organizing can get many organizational communication students yawning just by seeing the subject in a syllabus. Abundant movie and television examples associated with the machine-like nature of workplace productivity are often used to demonstrate…

  11. Reading the World's Classics Critically: A Keyword-Based Approach to Literary Analysis in Foreign Language Studies

    Science.gov (United States)

    García, Nuria Alonso; Caplan, Alison

    2014-01-01

    While there are a number of important critical pedagogies being proposed in the field of foreign language study, more attention should be given to providing concrete examples of how to apply these ideas in the classroom. This article offers a new approach to the textual analysis of literary classics through the keyword-based methodology originally…

  12. Histological and clinical findings in patients with post-transplantation and classical encapsulating peritoneal sclerosis: A European multicenter study

    NARCIS (Netherlands)

    J. Latus (Joerg); S.M. Habib (Meelad); D. Kitterer (Daniel); M.R. Korte (Mario); C. Ulmer (Christoph); P. Fritz (Peter); S. Davies (Simon); M. Lambie (Mark); M.D. Alscher (M. Dominik); M.G.H. Betjes (Michiel); S. Segerer (Stephan); N. Braun (Niko)

    2014-01-01

    textabstractBackground: Encapsulating peritoneal sclerosis (EPS) commonly presents after peritoneal dialysis has been stopped, either post-transplantation (PT-EPS) or after switching to hemodialysis (classical EPS, cEPS). The aim of the present study was to investigate whether PT-EPS and cEPS differ

  13. Understanding Resilience and Other Trajectories of Psychological Distress: a Mixed-Methods Study of Low-Income Mothers Who Survived Hurricane Katrina.

    Science.gov (United States)

    Lowe, Sarah R; Rhodes, Jean E; Waters, Mary C

    2015-09-01

    Recent longitudinal studies in the aftermath of natural disasters have shown that resilience, defined as a trajectory of consistently low symptoms, is the modal experience, although other trajectories representing adverse responses, including chronic or delayed symptom elevations, occur in a substantial minority of survivors. Although these studies have provided insight into the prototypical patterns of postdisaster mental health, the factors that account for these patterns remain unclear. In the current analysis, we aimed to fill this gap through a mixed-methods study of female participants in the Resilience in Survivors of Katrina (RISK) study. Latent class growth analysis identified six trajectories of psychological distress in the quantitative sample (n=386). Qualitative analysis of in-depth interviews with 54 participants identified predisaster, disaster-related and postdisaster experiences that could account for the trends in the quantitative data. In particular, preexisting and gains in psychosocial resources (e.g., emotion regulation, religiosity) and positive postdisaster impacts (e.g., greater neighborhood satisfaction, improved employment opportunities) were found to underlie resilience and other positive mental health outcomes. Conversely, experiences of childhood trauma, and pre and postdisaster stressors (e.g., difficulties in intimate partner relationships) were common among participants in trajectories representing adverse psychological responses. Illustrative case studies that exemplify each trajectory are presented. The results demonstrate the utility of mixed-methods analysis to provide a richer picture of processes underlying postdisaster mental health.

  14. Quasiclassical trajectory study of collisional energy transfer in toluene systems. I. Argon bath gas: Energy dependence and isotope effects

    Science.gov (United States)

    Lim, Kieran F.

    1994-05-01

    Experimental studies of collisional energy transfer from highly vibrationally excited toluene to various bath gases have recently been reported [Toselli and Barker, J. Chem. Phys. 97, 1809 (1992), and references therein]. A quasiclassical trajectory investigation for toluene in argon bath gas at 300 K for initial internal energies E'=41 000, 30 000, and 15 000 cm-1 is reported here. Collisional energy transfer is almost linearly dependent on E'. Predictions of energy transfer quantities are very sensitive to the average well depth of the assumed individual pairwise potentials, but is less sensitive to the detailed shape. Qualitative and quantitative agreement with experiment is obtained where the overall well depth is physically realistic. Isotope studies using 40Ar and pseudohelium (4Ar) bath gases indicate that energy transfer is independent of the mass of the bath-gas collider, but perdeuteration increases 1/2 by 13% over the undeuterated values.

  15. The role of river trajectories and channel recovery potential within sustainable river management: some case studies from southern Italy

    Science.gov (United States)

    Rosskopf, Carmen Maria; Scorpio, Vittoria; Patrizio Ciro Aucelli, Pietro

    2016-04-01

    ongoing narrowing. The assessment of evolutionary trajectories and current states of the study reaches coupled with the analysis of their connectivity at the reach to basin scale, has allowed to identify the reaches whose recovery potential and/or good ecological values maximizes the likelihood of success of future river restoration interventions. Nevertheless, as the study highlights, the widespread anthropization of river segments, including/connected to the study reaches, has to be taken in account. Therefore, any attempt to promote their natural dynamics and channel recovery, has to be accurately assessed in the framework of sustainable and risk-reduced river management according to implemented basin plans and other territorial constraints. Conversely, the obtained knowledge on the present status of river reaches and their potential near-future changes is fundamental in considering revising actual basin plans and/or programming monitoring activities.

  16. Negative events in childhood predict trajectories of internalizing symptoms up to young adulthood: an 18-year longitudinal study.

    Directory of Open Access Journals (Sweden)

    Maria Melchior

    Full Text Available Common negative events can precipitate the onset of internalizing symptoms. We studied whether their occurrence in childhood is associated with mental health trajectories over the course of development.Using data from the TEMPO study, a French community-based cohort study of youths, we studied the association between negative events in 1991 (when participants were aged 4-16 years and internalizing symptoms, assessed by the ASEBA family of instruments in 1991, 1999, and 2009 (n = 1503. Participants' trajectories of internalizing symptoms were estimated with semi-parametric regression methods (PROC TRAJ. Data were analyzed using multinomial regression models controlled for participants' sex, age, parental family status, socio-economic position, and parental history of depression.Negative childhood events were associated with an increased likelihood of concurrent internalizing symptoms which sometimes persisted into adulthood (multivariate ORs associated with > = 3 negative events respectively: high and decreasing internalizing symptoms: 5.54, 95% CI: 3.20-9.58; persistently high internalizing symptoms: 8.94, 95% CI: 2.82-28.31. Specific negative events most strongly associated with youths' persistent internalizing symptoms included: school difficulties (multivariate OR: 5.31, 95% CI: 2.24-12.59, parental stress (multivariate OR: 4.69, 95% CI: 2.02-10.87, serious illness/health problems (multivariate OR: 4.13, 95% CI: 1.76-9.70, and social isolation (multivariate OR: 2.24, 95% CI: 1.00-5.08.Common negative events can contribute to the onset of children's lasting psychological difficulties.

  17. Trajectories of sleep changes during the acute phase of traumatic brain injury: A 7-day actigraphy study

    Directory of Open Access Journals (Sweden)

    Hsiao-Yean Chiu

    2013-09-01

    Conclusion: Poor sleep efficiency and longer sleep duration are common symptoms in acute TBI patients. Both head injury severity and age predicted the trajectories of daytime and 24-hour sleep duration during the acute phase of TBI, whereas gender predicted the trajectories of 24-hour sleep duration in the mild TBI subgroup.

  18. Weight trajectories through infancy and childhood and risk of non-alcoholic fatty liver disease in adolescence: the ALSPAC study.

    Science.gov (United States)

    Anderson, Emma L; Howe, Laura D; Fraser, Abigail; Callaway, Mark P; Sattar, Naveed; Day, Chris; Tilling, Kate; Lawlor, Debbie A

    2014-09-01

    Adiposity is a key risk factor for NAFLD. Few studies have examined prospective associations of infant and childhood adiposity with subsequent NAFLD risk. We examined associations of weight-for-height trajectories from birth to age 10 with liver outcomes in adolescence, and assessed the extent to which associations are mediated through fat mass at the time of outcome assessment. Individual trajectories of weight and height were estimated for participants in the Avon Longitudinal Study of Parents and Children using random-effects linear-spline models. Associations of birthweight (adjusted for birth length) and weight change (adjusted for length/height change) from 0-3 months, 3 months-1 y, 1-3 y, 3-7 y, and 7-10 y with ultrasound scan (USS) determined liver fat and stiffness, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) at mean age 17.8 y were assessed with linear and logistic regressions. Mediation by concurrent fat mass was assessed with adjustment for fat mass at mean age 17.8 y. Birth weight was positively associated with liver stiffness and negatively with ALT and AST. Weight change from birth to 1 y was not associated with outcomes. Weight change from 1-3 y, 3-7 y, and 7-10 y was consistently positively associated with USS and blood-based liver outcomes. Adjusting for fat mass at mean age 17.8 y attenuated associations toward the null, suggesting associations are largely mediated by concurrent body fatness. Greater rates of weight-for-height change between 1 y and 10 y are consistently associated with adverse liver outcomes in adolescence. These associations are largely mediated through concurrent fatness. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  19. The role of social position and depressive symptoms in adolescence for life-course trajectories of education and work: a cohort study.

    Science.gov (United States)

    Landstedt, Evelina; Brydsten, Anna; Hammarström, Anne; Virtanen, Pekka; Almquist, Ylva B

    2016-11-18

    While a vast amount of studies confirm the social reproduction of class and status from one generation to the next, less is known about the role of health in the child generation for these processes. Research has shown that particularly mental distress in adolescence is important for future life chances. This study aimed to examine the importance of parental socioeconomic position and depressive symptoms in youth for life-course trajectories of education and labour market attachment among men and women. Based on four waves of questionnaire data from the Northern Swedish Cohort (n = 1,001), consisting of individuals born in 1965, three steps of gender-separate analyses were undertaken. First, the individual trajectories of education and labour market attachment from age 18 to 42 were mapped through sequence analysis. Second, cluster analysis was used to identify typical trajectories. Third, two indicators of parental socioeconomic position - occupational class and employment status - and depressive symptoms at age 16 were used in multinomial regression analyses to predict adult life-course trajectories. Four typical trajectories were identified for men, of which three were characterised by stable employment and various lengths of education, and the fourth reflected a more unstable situation. Among women, five trajectories emerged, characterised by more instability compared to men. Low parental occupational class and unemployment were significantly associated with a higher risk of ending up in less advantaged trajectories for men while, for women, this was only the case for occupational class. Youth levels of depressive symptoms did not significantly differ across the trajectories. This study found support for the intergenerational reproduction of social position, particularly when measured in terms of parental occupational class. Youth depressive symptoms did not show clear differences across types of trajectories, subsequently impeding such symptoms to trigger any

  20. Trajectories of physical and mental health among persons with morbid obesity and persons with COPD: a longitudinal comparative study

    Directory of Open Access Journals (Sweden)

    Bonsaksen T

    2016-04-01

    Full Text Available Tore Bonsaksen,1 May Solveig Fagermoen,2 Anners Lerdal2,3 1Department of Occupational Therapy, Prosthetics and Orthotics, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, 2Department of Nursing Science, Institute of Health and Society, Faculty of Medicine, University of Oslo, 3Department for Patient Safety and Development, Lovisenberg Diakonale Hospital, Oslo, NorwayBackground: Morbid obesity and chronic obstructive pulmonary disease (COPD are prevalent diseases associated with impaired health-related quality of life (HRQoL. Research generally indicates that persons with morbid obesity increase their HRQoL following intervention, whereas evidence of increases in HRQoL in persons with COPD is mixed. Examining the patterns of change over time instead of merely examining whether HRQoL changes will add to the knowledge in this field.Methods: A sample of persons with morbid obesity and persons with COPD was recruited from learning and mastery courses and rehabilitation centers in Norway. The data were collected by self-report questionnaires at the start of patient education and at four subsequent time points during the 1-year follow-up. HRQoL was measured with the Short Form 12, version 2, and repeated measures analysis of variance was employed in the statistical analysis.Results: Participants with morbid obesity linearly increased their physical HRQoL during the 1-year follow-up, whereas participants with COPD showed no change. None of the groups changed their mental HRQoL during follow-up. In all subdomains of HRQoL, the participants with morbid obesity showed favorable, linearly increasing trajectories across the follow-up period. Among the participants with COPD, no change patterns occurred in the subdomains of HRQoL, except for a fluctuating pattern in the mental health domain. Age, sex, and work status did not influence the trajectories of HRQoL in any of the domains.Conclusion: A more favorable trajectory

  1. The trajectory of physical and mental health from injury to 5 years after multiple trauma: a prospective, longitudinal cohort study.

    Science.gov (United States)

    Soberg, Helene L; Finset, Arnstein; Roise, Olav; Bautz-Holter, Erik

    2012-05-01

    To describe the trajectory of physical and mental health from injury to 5 years postinjury for patients with multiple trauma, and to examine predictors of recovery of physical and mental health. A prospective, longitudinal cohort study with data from injury (baseline), the return home (t1), and 1 (t2), 2 (t3), and 5 (t4) years. Hospital and community setting. Patients (N=105; mean age ± SD, 35.3±14.0y; age range, 18-67y; 83% men) with multiple trauma and a New Injury Severity Score (NISS) ≥16 treated at a regional trauma referral center. Mean NISS ± SD was 34.6±12.6, and mean Glasgow Coma Scale (GCS) score ± SD was 12.2±3.9. Not applicable. Medical Outcomes Study 36-Item Short-Form Health Survey physical component summary (PCS) and mental component summary (MCS), injury severity parameters, and World Health Organization Disability Assessment Schedule II (WHODAS II) for activities and participation. The proportion with poor physical health (women) (B=-4.24, P=.003), education (low/high) (B=3.43, P=.019), and WHODAS II cognitive function (B=.18, P<.001) and Participation in society (B=.18, P≤.001). Physical and mental health over the 5 years improved with time, but was still significantly below population means. The physical and mental health status stabilized, but the recovery trajectories differed for physical and mental health. Predictors of health were personal and injury-related factors and function in a biopsychosocial perspective. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  2. Family and neighbourhood socioeconomic inequalities in childhood trajectories of BMI and overweight: longitudinal study of Australian children.

    Directory of Open Access Journals (Sweden)

    Pauline W Jansen

    Full Text Available BACKGROUND: Socioeconomic inequalities in longitudinal patterning of childhood overweight could cause marked differentials in total burden by adulthood. This study aims to determine timing and strength of the association between socioeconomic status (SES and children's body mass index (BMI in the pre- and primary school years, and to examine socioeconomic differences in overweight trajectories across childhood. METHODS: Participants were 4949 children from the Longitudinal Study of Australian Children. BMI was measured at four biennial waves starting at age 4-5 years in 2004. Developmental trajectories of childhood overweight were identified with latent class analyses. Composite variables of family and neighbourhood SES were used. RESULTS: Socioeconomic differences in mean BMI z-scores already present at age 4-5 more than doubled by age 10-11 years, reflecting decreasing mean BMI among advantaged rather than increasing means among disadvantaged children. Latent class analysis identified children with 'stable normal weight' (68%, and with 'persistent' (15%, 'late-onset' (14%, and 'resolving' overweight (3%. Risks of persistent and late-onset childhood overweight were highest among low SES families (e.g. most disadvantaged quintile: OR(persistent = 2.51, 95%CI: 1.83-3.43, and only partly explained by birth weight and parental overweight. Relationships with neighbourhood SES were weaker and attenuated fully on adjustment for family SES. No socioeconomic gradient was observed for resolving overweight. CONCLUSIONS: Childhood has become the critical period when socioeconomic inequalities in overweight emerge and strengthen. Although targeting disadvantaged children with early overweight must be a top priority, the presence of childhood overweight even among less-disadvantaged families suggests only whole-society approaches will eliminate overweight-associated morbidity.

  3. First-principles and classical molecular dynamics study of threshold displacement energy in beryllium

    Science.gov (United States)

    Vladimirov, P. V.; Borodin, V. A.

    2017-02-01

    Beryllium selected as a neutron multiplier material for the tritium breeding blanket of fusion reactor should withstand high doses of fast neutron irradiation. The damage produced by irradiation is usually evaluated assuming that the number of atomic displacements to the threshold displacement energy, Ed, which is considered as an intrinsic material parameter. In this work the value of Ed for hcp beryllium is estimated simultaneously from classical and first-principles molecular dynamics simulations. Quite similar quantitative pictures of defect production are observed in both simulation types, though the predicted displacement threshold values seem to be approximately two times higher in the first-principles approach. We expect that, after more detailed first-principles investigations, this approach can be used for scaling the damage prediction predictions by classical molecular dynamics, opening a way for more consistent calculations of displacement damage in materials.

  4. Resistance exponential in coverage does shape not necessarily indicate tunneling: a classical Monte-Carlo study

    Science.gov (United States)

    Romero, A. H.; Rabson, D. A.; Schuller, Ivan K.

    1998-03-01

    In experiments sandwiching a thin insulating layer between two conductors (ferromagnetic, superconducting or normal), an exponential dependence of resistance on the thickness of the insulator is often cited as evidence of tunneling( ``Tunneling phenomena in solids'', edited by E. Burnstein and S. Lundqvist, Plenum Press, N.Y. 1969.). However, when one or more of the surfaces is rough, such an exponential dependence on the average insulating coverage can arise instead from classical physics. We present Monte-Carlo results in two realistic cases, a random-potential model(M. B. Isichenko, Rev. Mod. Phys. 64) 961 (1992). and a modified molecular-beam-epitaxy model accounting for deposition, cluster diffusion, aggregation, and stratification(P. Jensen, A.-L. Barabási, H. Larralde, S. Havlin and H. Stanley, Nature 368) 22 (1994).. This latter model gives morphologies similar to those found in experiments. We discuss how to distinguish the competing classical and tunneling contributions to the resistance.

  5. Magnetic monopoles and dyons revisited: A useful contribution to the study of classical mechanics

    OpenAIRE

    Santos, Renato P. dos

    2015-01-01

    Graduate level physics curricula in many countries around the world, as well as senior-level undergraduate ones in some major institutions, include Classical Mechanics courses, mostly based on Goldstein's textbook masterpiece. During the discussion of central force motion, however, the Kepler problem is virtually the only serious application presented. In this paper, we present another problem that is also soluble, namely the interaction of Schwinger's dual-charged (dyon) particles. While the...

  6. Childhood trajectories of inattention and hyperactivity and prediction of educational attainment in early adulthood: a 16-year longitudinal population-based study.

    Science.gov (United States)

    Pingault, Jean-Baptiste; Tremblay, Richard E; Vitaro, Frank; Carbonneau, René; Genolini, Christophe; Falissard, Bruno; Côté, Sylvana M

    2011-11-01

    Literature clearly documents the association between mental health problems, particularly attention deficit hyperactivity disorder (ADHD), and educational attainment. However, inattention and hyperactivity are generally not considered independently from each other in prospective studies. The aim of the present study was to differentiate the unique, additive, or interactive contributions of inattention and hyperactivity symptoms to educational attainment. The authors randomly selected 2,000 participants from a representative sample of Canadian children and estimated developmental trajectories of inattention and hyperactivity between the ages of 6 and 12 years using yearly assessments. High school graduation status, at age 22-23 years, was obtained from official records. Four trajectories of inattention and four trajectories of hyperactivity were observed between the ages of 6 and 12 years. After controlling for hyperactivity and other confounding variables, a high inattention trajectory (compared with low inattention) strongly predicted not having a high school diploma at 22-23 years of age (odds ratio=7.66, 95% confidence interval [CI]=5.06-11.58). To a lesser extent, a declining or rising trajectory of inattention also made a significant contribution (odds ratios of 2.67 [95% CI=1.90-3.75] and 3.87 [95% CI=2.75-5.45], respectively). Hyperactivity was not a significant predictor once inattention was taken into account. Inattention rather than hyperactivity during elementary school significantly predicts long-term educational attainment. Children with attention problems, regardless of hyperactivity, need preventive intervention early in their development.

  7. Experimental study of Counter-Rotating Vortex Pair Trajectories induced by a Round Jet in Cross-Flow at Low Velocity Ratios

    CERN Document Server

    Cambonie, T; Aider, J -L

    2013-01-01

    Circular flush Jets In Cross-Flow were experimentally studied in a water tunnel using Volumetric Particle Tracking Velocimetry, for a range of jet to cross-flow velocity ratios, r, from 0.5 to 3, jet exit diameters $d$ from 0.8 cm to 1 cm and cross-flow boundary layer thickness delta from 1 to 2.5 cm. The analysis of the 3D mean velocity fields allows for the definition, computation and study of Counter-rotating Vortex Pair trajectories. The influences of r, d and delta were investigated. A new scaling based on momentum ratio r_m taking into account jet and cross-flow momentum distributions is introduced based on the analysis of jet trajectories published in the literature. Using a rigorous scaling quality factor Q to quantify how well a given scaling successfully collapses trajectories, we show that the proposed scaling also improves the collapse of CVP trajectories, leading to a final scaling law for these trajectories.

  8. Using the life course perspective to study the entry into the illness trajectory: the perspective of caregivers of people with Alzheimer's disease.

    Science.gov (United States)

    Carpentier, Normand; Bernard, Paul; Grenier, Amanda; Guberman, Nancy

    2010-05-01

    The research community is showing increasing interest in the analysis of the care trajectory of people with chronic health problems, especially dementias such as Alzheimer's disease. However, despite this interest, there is little research on the initial phases of the care trajectory. The fact that the first symptoms of dementia are generally noticed by those surrounding the elderly person suggests that the recognition of the disease is intimately linked to interactions not only amongst family members but also amongst friends, neighbours and health professionals. This study focuses on the period beginning with the first manifestations of cognitive difficulties and ending with the diagnosis of Alzheimer-type dementia. Interviews with 60 caregivers in Montreal, Canada were used to reconstruct how older people with Alzheimer-type dementia enter into the care trajectory. Our methods consisted of the analysis of social networks, social dynamics and action sequences. Our findings are presented in the form of a typology comprised of 5 pathways of entries into the care trajectory that are structured around the following four principles of the Life Course Perspective: family history, linked lives, human agency and organisational effects. We believe that analyses of the initial phases of the care trajectory, such as this one, are essential for the application of effective early detection and intervention policies. They are also central to informing future studies that seek to understand the care experience in its entirety. Crown Copyright (c) 2010. Published by Elsevier Ltd. All rights reserved.

  9. A Numerical Study of Low-Thrust Limited Power Trajectories between Coplanar Circular Orbits in an Inverse-Square Force Field

    Directory of Open Access Journals (Sweden)

    Sandro da Silva Fernandes

    2012-01-01

    Full Text Available A numerical study of optimal low-thrust limited power trajectories for simple transfer (no rendezvous between circular coplanar orbits in an inverse-square force field is performed by two different classes of algorithms in optimization of trajectories. This study is carried out by means of a direct method based on gradient techniques and by an indirect method based on the second variation theory. The direct approach of the trajectory optimization problem combines the main positive characteristics of two well-known direct methods in optimization of trajectories: the steepest-descent (first-order gradient method and a direct second variation (second-order gradient method. On the other hand, the indirect approach of the trajectory optimization problem involves two different algorithms of the well-known neighboring extremals method. Several radius ratios and transfer durations are considered, and the fuel consumption is taken as the performance criterion. For small-amplitude transfers, the results are compared to the ones provided by a linear analytical theory.

  10. Trajectories of childhood internalizing and externalizing psychopathology and psychotic-like experiences in adolescence: A prospective population-based cohort study.

    Science.gov (United States)

    Lancefield, Kristin S; Raudino, Alessandra; Downs, Johnny M; Laurens, Kristin R

    2016-05-01

    Adolescent internalizing and externalizing psychopathology is strongly associated with adult psychiatric morbidity, including psychotic disorders. This study examined whether internalizing or externalizing trajectories (continuity/discontinuity of symptoms) from middle childhood were associated with adolescent psychotic-like experiences (PLEs). Prospective data were collected from a community sample of 553 children (mean age = 10.4 years; 50% male) and their primary caregivers. Participants completed questionnaire reports of internalizing and externalizing psychopathology and PLEs at baseline, and again approximately 2 years later. Logistic regression was used to examine the association of adolescent PLEs with four trajectories of internalizing and externalizing psychopathology (persistent, incident, remitting, and none), controlling for a range of potential confounders and sampling bias. Significant associations were identified between adolescent PLEs and the incident internalizing (adjusted odds ratio [adj. OR] = 2.96; 95% confidence interval [CI] = 1.60-5.49) and externalizing psychopathology (adj. OR = 2.14; 95% CI = 1.11-4.14) trajectories, as well as the persistent internalizing (adj. OR = 1.90; 95% CI = 1.13-3.18) and externalizing (adj. OR = 1.81, 95% CI = 1.02-3.19) trajectories. Children with remitting psychopathology trajectories were no more likely to present later PLEs than those who never experienced psychopathology. While for many individuals symptoms and illness remit during development without intervention, this study provides important insights regarding potential targets and timing for delivery of early intervention and prevention programs.

  11. Exploring the Trajectory of Personal, Moral and Spiritual Values of 16- to 18-Year-Old Students Taking Religious Studies at A Level in the UK

    Science.gov (United States)

    Francis, Leslie J.; Village, Andrew; Parker, Stephen G.

    2017-01-01

    This study set out to explore the trajectory of personal, moral and spiritual values of students taking Religious Studies at A level in the UK. A sample of 150 students completed a battery of measures at the beginning of their period of A level study and again at the end. The data found no difference over this period of time in personal values…

  12. Seven Steps Towards the Classical World

    CERN Document Server

    Allori, V; Goldstein, S; Zanghì, N; Allori, Valia; Goldstein, Shelly; Zangh\\'{\\i}, Nino

    2001-01-01

    Classical physics is about real objects, like apples falling from trees, whose motion is governed by Newtonian laws. In standard Quantum Mechanics only the wave function or the results of measurements exist, and to answer the question of how the classical world can be part of the quantum world is a rather formidable task. However, this is not the case for Bohmian mechanics, which, like classical mechanics, is a theory about real objects. In Bohmian terms, the problem of the classical limit becomes very simple: when do the Bohmian trajectories look Newtonian?

  13. An air-mass trajectory study of the transport of radioactivity from Fukushima to Thessaloniki, Greece and Milan, Italy

    Science.gov (United States)

    Ioannidou, A.; Giannakaki, E.; Manolopoulou, M.; Stoulos, S.; Vagena, E.; Papastefanou, C.; Gini, L.; Manenti, S.; Groppi, F.

    2013-08-01

    Analyses of 131I, 137Cs and 134Cs in airborne aerosols were carried out in daily samples at two different sites of investigation: Thessaloniki, Greece (40° N) and Milan, Italy (45° N) after the Fukushima accident during the period of March-April, 2011. The radionuclide concentrations were determined and studied as a function of time. The 131I concentration in air over Milan and Thessaloniki peaked on April 3-4, 2011, with observed activities 467 μBq m-3 and 497 μBq m-3, respectively. The 134Cs/137Cs activity ratio values in air were around 1 in both regions, related to the burn-up history of the damaged nuclear fuel of the destroyed nuclear reactor. The high 131I/137Cs ratio, observed during the first days after the accident, followed by lower values during the following days, reflects not only the initial release ratio but also the different volatility, attachment and removal of the two isotopes during transportation due to their different physico-chemical properties. No artificial radionuclides could be detected in air after April 28, 2011 in both regions of investigation. The different maxima of airborne 131I and 134,137Cs in these two regions were related to long-range air mass transport from Japan, across the Pacific and to Central Europe. Analysis of backward trajectories was used to confirm the arrival of artificial radionuclides following atmospheric transport and processing. HYSPLIT backward trajectories were applied for the interpretation of activity variations of measured radionuclides.

  14. Complex plasmas and colloidal dispersions particle-resolved studies of classical liquids and solids

    CERN Document Server

    Ivlev, Alexei; Morfill, Gregor; Royall, C. Patrick

    2012-01-01

    Complex plasmas and colloidal dispersions represent different states of soft matter. They are complementary in many ways, with the most important being that complex plasmas are virtually undamped at the particle timescales, whereas colloidal dispersions are overdamped and therefore can be brought into equilibrium in a very controlled manner. Otherwise, both fields have similar advantages: fully resolved 3D particle trajectories can easily be visualized, the pair interactions are tunable, and particles can be manipulated individually or collectively. These unique properties allow us to investigate generic processes occurring in liquids or solids at the most fundamental individual particle level. The principal research topics to be addressed in the book include: particle dynamics in liquids, with the emphasis on mesoscopic processes in the supercooled (glassy) state, e.g. dynamical heterogeneity, phase transitions in solids, with particular attention to the evolutionary paths of crystal structure development an...

  15. Quantum trajectories based on the weak value

    Science.gov (United States)

    Mori, Takuya; Tsutsui, Izumi

    2015-04-01

    The notion of the trajectory of an individual particle is strictly inhibited in quantum mechanics because of the uncertainty principle. Nonetheless, the weak value, which has been proposed as a novel and measurable quantity definable to any quantum observable, can offer a possible description of trajectory on account of its statistical nature. In this paper, we explore the physical significance provided by this "weak trajectory" by considering various situations where interference takes place simultaneously with the observation of particles, that is, in prototypical quantum situations for which no classical treatment is available. These include the double slit experiment and Lloyd's mirror, where in the former case it is argued that the real part of the weak trajectory describes an average over the possible classical trajectories involved in the process, and that the imaginary part is related to the variation of interference. It is shown that this average interpretation of the weak trajectory holds universally under the complex probability defined from the given transition process. These features remain essentially unaltered in the case of Lloyd's mirror where interference occurs with a single slit.

  16. Probability representation of classical states

    NARCIS (Netherlands)

    Man'ko, OV; Man'ko, [No Value; Pilyavets, OV

    2005-01-01

    Probability representation of classical states described by symplectic tomograms is discussed. Tomographic symbols of classical observables which are functions on phase-space are studied. Explicit form of kernel of commutative star-product of the tomographic symbols is obtained.

  17. Quantum versus classical descriptions of sub-Poissonian light generation in three-wave mixing

    CERN Document Server

    Bajer, J; Bajer, Jiri; Miranowicz, Adam

    2001-01-01

    Sub-Poissonian light generation in the non-degenerate three-wave mixing is studied numerically and analytically within quantum and classical approaches. Husimi Q-functions and their classical trajectory simulations are analysed to reveal a special regime corresponding to the time-stable sub-Poissonian photocount statistics of the sum-frequency mode. Conditions for observation of this regime are discussed. Theoretical predictions of the Fano factor and explanation of the extraordinary stabilization of the sub-Poissonian photocount behavior are obtained analytically by applying the classical trajectories. Scaling laws for the maximum sub-Poissonian behavior are found. Noise suppression levels in the non-degenerate vs degenerate three-wave mixing are discussed on different time scales compared to the revival times. It is shown that the non-degenerate conversion offers much better stabilization of the suppressed noise in comparison to that of degenerate process.

  18. 传统《诗经》学的重大历史转折 ——朱熹“以《诗》言《诗》”说申论%The historic turning point of traditional studies on classic poetry ——ZHU Xi 's theory of commenting on classic poetry through classic poetry

    Institute of Scientific and Technical Information of China (English)

    汪大白

    2001-01-01

    ZHU Xi's theory of and his deeds in commenting on Classic Poetry through Classic Poetry is a negation and criticism on the idea of illustrating Classic Poetry with history expressed in “the Preface to Classic Poetry" and the Confucianists' concept of illustrating Classic Poetry with “the Preface to Classic Poetry". It also shows a deep understanding on the literature nature of Classic Poetry and the rules in composing poems. To carry out the principle of commenting on classic Poetry through Classic Poetry and to implement a great reform on traditional studies on classic Poetry is a great mission for scholars in Song Dynasty from the need of historical development and the time. Being a famous literaturist as well as a master in the studies on Classic Poetry and integrating literature of past dynasties with the studies on “Classic Poetry" of past dynasties are the main condition and the objective foundation for ZHU Xi to implement his reform on the studies on classic Poetry.%朱熹首倡并躬行的“以《诗》言《诗》”说是对《诗序》“以史证《诗》”以及后儒“以《序》解《诗》”的否定与批判,同时又体现了对《诗经》文学本质与诗歌创作规律的深刻认识。贯彻“以《诗》言《诗》”的原则,实现传统《诗经》学的重大变革,是历史的发展与时代的需求赋予宋代学者的重大使命;而文学名家与经学大师的一身兼任,历代文学与历代经学的双轨集成,是朱熹实现《诗经》学变革的主体条件与客观基础。

  19. [Classical taxomomies].

    Science.gov (United States)

    Liubarskiĭ, G Iu

    2006-01-01

    The sequence of classic paradigms in taxonomy that partly replaced each other and partly co-exist is given as follows: the theory of "organ and organism similarity", the naturalistic theory, the descriptive theory, and the phylogenetic theory. The naturalistic classics accepted the notion of "the plan of creation". The rejection of appealing to this plan brought forth certain problems in the formulation of the purpose of taxonomy; these problems were differently solved by the descriptive and the phylogenetic classic traditions. The difficulties of the current paradigms arising from the loss of a "strong purpose", a problem to be solved by taxonomists that is to be clear and interesting to a wide range of non-professionals. The paradox of formalization led to the losing of content of the methods due to their formalization. To attract attention to taxonomy, a new "image of the results" of its work that would be interesting to the non-professionals is necessary. The co-existence of different methods of reseach applied to different groups of facts leads to the loss of integrity of the research. It is not only that the taxon becomes a hypothesis and such hypotheses multiply. The comparison of these hypotheses is problematic, because each of them is supported by its own independent scope of facts. Because of the existence of a fundamental meronotaxonomic discrepancy, taxonomic systems based on different groups of characters appear to be incomparable, being rather systems of characters than systems of taxa. Systems of characters are not directly comparable with each other; they can be compared only through appealing to taxa, but taxa themselves exist only in the form of a number of hypotheses. Consequently, each separate taxonomic approach creates its own nature, its own subject of research. Therefore, it is necessary to describe the subject of research correctly (and indicate the purpose of research), as well as to distinguish clearly between results achieved through

  20. Quantum Tunneling and Complex Trajectories

    Science.gov (United States)

    Meynig, Max; Haggard, Hal

    2017-01-01

    In general, the semiclassical approximation of quantum mechanical tunneling fails to treat tunneling through barriers if real initial conditions and trajectories are used. By analytically continuing classical dynamics to the complex plane the problems encountered in the approximation can be resolved. While, the complex methods discussed here have been previously explored, no one has exhibited an analytically solvable case. The essential features of the complex method will be discussed in the context of a novel, analytically solvable problem. These methods could be useful in quantum gravity, with applications to the tunneling of spacetime geometries.

  1. Single and double ionization of magnesium by electron impact: A classical study

    Science.gov (United States)

    Dubois, J.; Berman, S. A.; Chandre, C.; Uzer, T.

    2017-02-01

    We consider electron impact-driven single and double ionization of magnesium in the energy range of 10 to 100 eV. Our classical Hamiltonian model of these (e ,2 e ) and (e ,3 e ) processes sheds light on their total cross sections and reveals the underlying ionization mechanisms. Two pathways are at play in single ionization: delayed and direct. In contrast, only the direct process is observed in double ionization, ruling out the excitation-autoionization channel. We also provide evidence that the so-called Two-Step 2 mechanism predominates over the Two-Step 1 mechanism, in agreement with experiments.

  2. Archaeomagnetic Investigation at Chapultepec, Mexico City: Case Study of Classical Settlers

    Science.gov (United States)

    Lopez, V.; Romero, E.; Soler-Arechalde, A. M.; Espinosa, G.

    2007-05-01

    During the restoration campaign at the Chapultepec Park in Mexico City downtown, a teotihuacan settlement was found at the south flank of Chapultepec Hill. Samples represent a kind of irregular home kilns with a hole in their central part bounded by andesite rocks. Alternating field demagnetization had been employed. Rock magnetic measurements which included: Hysteresis, continuous susceptibility and isothermal remanence experiments revealed that some spinels, most probably magnetite or Ti-poor Titanomagnetites are responsible for the remanence. An archeomagnetic date obtained here is of 525 AD which is in good agreement with other evidences of the Teotihuacan Classic Metepec period (450-600 AD).

  3. Early PTSD symptom trajectories: persistence, recovery, and response to treatment: results from the Jerusalem Trauma Outreach and Prevention Study (J-TOPS.

    Directory of Open Access Journals (Sweden)

    Isaac R Galatzer-Levy

    Full Text Available CONTEXT: Uncovering heterogeneities in the progression of early PTSD symptoms can improve our understanding of the disorder's pathogenesis and prophylaxis. OBJECTIVES: To describe discrete symptom trajectories and examine their relevance for preventive interventions. DESIGN: Latent Growth Mixture Modeling (LGMM of data from a randomized controlled study of early treatment. LGMM identifies latent longitudinal trajectories by exploring discrete mixture distributions underlying observable data. SETTING: Hadassah Hospital unselectively receives trauma survivors from Jerusalem and vicinity. PARTICIPANTS: Adult survivors of potentially traumatic events consecutively admitted to the hospital's emergency department (ED were assessed ten days and one-, five-, nine- and fifteen months after ED admission. Participants with data at ten days and at least two additional assessments (n = 957 were included; 125 received cognitive behavioral therapy (CBT between one and nine months. APPROACH: We used LGMM to identify latent parameters of symptom progression and tested the effect of CBT on these parameters. CBT consisted of 12 weekly sessions of either cognitive therapy (n = 41 or prolonged exposure (PE, n = 49, starting 29.8±5.7 days after ED admission, or delayed PE (n = 35 starting at 151.8±42.4 days. CBT effectively reduced PTSD symptoms in the entire sample. MAIN OUTCOME MEASURE: Latent trajectories of PTSD symptoms; effects of CBT on these trajectories. RESULTS: THREE TRAJECTORIES WERE IDENTIFIED: Rapid Remitting (rapid decrease in symptoms from 1- to 5-months; 56% of the sample, Slow Remitting (progressive decrease in symptoms over 15 months; 27% and Non-Remitting (persistently elevated symptoms; 17%. CBT accelerated the recovery of the Slow Remitting class but did not affect the other classes. CONCLUSIONS: The early course of PTSD symptoms is characterized by distinct and diverging response patterns that are centrally relevant to

  4. Early PTSD Symptom Trajectories: Persistence, Recovery, and Response to Treatment: Results from the Jerusalem Trauma Outreach and Prevention Study (J-TOPS)

    Science.gov (United States)

    Galatzer-Levy, Isaac R.; Ankri, Yael; Freedman, Sara; Israeli-Shalev, Yossi; Roitman, Pablo; Gilad, Moran; Shalev, Arieh Y.

    2013-01-01

    Context Uncovering heterogeneities in the progression of early PTSD symptoms can improve our understanding of the disorder's pathogenesis and prophylaxis. Objectives To describe discrete symptom trajectories and examine their relevance for preventive interventions. Design Latent Growth Mixture Modeling (LGMM) of data from a randomized controlled study of early treatment. LGMM identifies latent longitudinal trajectories by exploring discrete mixture distributions underlying observable data. Setting Hadassah Hospital unselectively receives trauma survivors from Jerusalem and vicinity. Participants Adult survivors of potentially traumatic events consecutively admitted to the hospital's emergency department (ED) were assessed ten days and one-, five-, nine- and fifteen months after ED admission. Participants with data at ten days and at least two additional assessments (n = 957) were included; 125 received cognitive behavioral therapy (CBT) between one and nine months. Approach We used LGMM to identify latent parameters of symptom progression and tested the effect of CBT on these parameters. CBT consisted of 12 weekly sessions of either cognitive therapy (n = 41) or prolonged exposure (PE, n = 49), starting 29.8±5.7 days after ED admission, or delayed PE (n = 35) starting at 151.8±42.4 days. CBT effectively reduced PTSD symptoms in the entire sample. Main Outcome Measure Latent trajectories of PTSD symptoms; effects of CBT on these trajectories. Results Three trajectories were identified: Rapid Remitting (rapid decrease in symptoms from 1- to 5-months; 56% of the sample), Slow Remitting (progressive decrease in symptoms over 15 months; 27%) and Non-Remitting (persistently elevated symptoms; 17%). CBT accelerated the recovery of the Slow Remitting class but did not affect the other classes. Conclusions The early course of PTSD symptoms is characterized by distinct and diverging response patterns that are centrally relevant to understanding the disorder

  5. Developmental trajectories of adolescent cannabis use and their relationship to young adult social and behavioural adjustment: A longitudinal study of Australian youth.

    Science.gov (United States)

    Scholes-Balog, Kirsty E; Hemphill, Sheryl A; Evans-Whipp, Tracy J; Toumbourou, John W; Patton, George C

    2016-02-01

    This study aimed to identify distinct developmental trajectories (sub-groups of individuals who showed similar longitudinal patterns) of cannabis use among Australian adolescents, and to examine associations between trajectory group membership and measures of social and behavioural adjustment in young adulthood. Participants (n=852, 53% female) were part of the International Youth Development Study. Latent class growth analysis was used to identify distinct trajectories of cannabis use frequency from average ages 12 to 19, across 6 waves of data. Logistic regression analyses and analyses of covariance were used to examine relationships between trajectory group membership and young adult (average age: 21) adjustment, controlling for a range of covariates. Three trajectories were identified: abstainers (62%), early onset users (11%), and late onset occasional users (27%). The early onset users showed a higher frequency of antisocial behaviour, violence, cannabis use, cannabis-related harms, cigarette use, and alcohol harms, compared to the abstinent group in young adulthood. The late onset occasional users reported a higher frequency of cannabis use, cannabis-related harms, illicit drug use, and alcohol harms, compared to the abstinent group in young adulthood. There were no differences between the trajectory groups on measures of employment, school completion, post-secondary education, income, depression/anxiety, or alcohol use problems. In conclusion, early onset of cannabis use, even at relatively low frequency during adolescence, is associated with poorer adjustment in young adulthood. Prevention and intervention efforts to delay or prevent uptake of cannabis use should be particularly focussed on early adolescence prior to age 12. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. A CLUSTERING OF DJA STOCKS - THE APPLICATION IN FINANCE OF A METHOD FIRST USED IN GENE TRAJECTORY STUDY

    Directory of Open Access Journals (Sweden)

    Silaghi Gheorghe Cosmin

    2009-05-01

    Full Text Available Previously we employed the Gene Trajectory Clustering methodology to search for different associations of the stocks composing the DJA index, with the aim of finding different, logic clusters, supported by economic reasons, preferably different than the

  7. OPTIMAL TRAJECTORY PLANNING OF MANIPULATORS: A REVIEW

    Directory of Open Access Journals (Sweden)

    ATEF A. ATA

    2007-04-01

    Full Text Available Optimal motion planning is very important to the operation of robot manipulators. Its main target is the generation of a trajectory from start to goal that satisfies objectives, such as minimizing path traveling distance or time interval, lowest energy consumption or obstacle avoidance and satisfying the robot’s kinematics and dynamics. Review, discussion and analysis of optimization techniques to find the optimal trajectory either in Cartesian space or joint space are presented and investigated. Optimal trajectory selection approaches such as kinematics and dynamics techniques with various constraints are presented and explained. Although the kinematics approach is simple and straight forward, it will experience some problems in implementation because of lack of Inertia and torque constraints. The application of Genetic Algorithms to find the optimal trajectory of manipulators especially in the obstacle avoidance is also highlighted. Combining the Genetic Algorithms with other classical optimization methods proves to have better performance as a hybrid optimization technique.

  8. Comparison of classical and quantal calculations of helium three-body recombination

    CERN Document Server

    Pérez-Ríos, Jesús; Wang, Jia; Greene, Chris H

    2013-01-01

    A general method to study classical scattering in $n$-dimension is developed. Through classical trajectory calculations, the three-body recombination is computed as a function of the collision energy for helium atoms, as an example. Quantum calculations are also performed for the $J^{\\Pi}$ = $0^{+}$ symmetry of the three-body recombination rate in order to compare with the classical results, yielding good agreement for $E\\gtrsim$ 1 K. The classical threshold law is derived and numerically confirmed for the Newtonian three-body recombination rate. Finally, a relationship is found between the quantum and classical three-body hard hypersphere elastic cross sections which is analogous to the well-known shadow scattering in two-body collisions.

  9. Ancient mythological images and their interpretation: an introduction to iconology, semiotics and image studies in classical art history

    OpenAIRE

    Lorenz, Katharina

    2016-01-01

    When we try to make sense of pictures, what do we gain when we use a particular method - and what might we be missing or even losing? Empirical experimentation on three types of mythological imagery - a Classical Greek pot, a frieze from Hellenistic Pergamon and a second-century CE Roman sarcophagus - enables Katharina Lorenz to demonstrate how theoretical approaches to images (specifically, iconology, semiotics, and image studies) impact the meanings we elicit from Greek and Roman art. A gui...

  10. Path-based Queries on Trajectory Data

    DEFF Research Database (Denmark)

    Krogh, Benjamin Bjerre; Pelekis, Nikos; Theodoridis, Yannis

    2014-01-01

    a specific path by only retrieving data from the first and last edge in the path. To correctly answer strict path queries existing network-constrained trajectory indexes must retrieve data from all edges in the path. An extensive performance study of NETTRA using a very large real-world trajectory data set....... To efficiently support strict path queries, we present a novel NETwork-constrained TRAjectory index (NETTRA). This index enables very efficient retrieval of trajectories that follow a specific path, i.e., strict path queries. NETTRA uses a new path encoding scheme that can determine if a trajectory follows......, consisting of 1.7 million trajectories (941 million GPS records) and a road network with 1.3 million edges, shows a speed-up of two orders of magnitude compared to state-of-the-art trajectory indexes....

  11. A study of quantum mechanical probabilities in the classical Hodgkin-Huxley model.

    Science.gov (United States)

    Moradi, N; Scholkmann, F; Salari, V

    2015-03-01

    The Hodgkin-Huxley (HH) model is a powerful model to explain different aspects of spike generation in excitable cells. However, the HH model was proposed in 1952 when the real structure of the ion channel was unknown. It is now common knowledge that in many ion-channel proteins the flow of ions through the pore is governed by a gate, comprising a so-called "selectivity filter" inside the ion channel, which can be controlled by electrical interactions. The selectivity filter (SF) is believed to be responsible for the selection and fast conduction of particular ions across the membrane of an excitable cell. Other (generally larger) parts of the molecule such as the pore-domain gate control the access of ions to the channel protein. In fact, two types of gates are considered here for ion channels: the "external gate", which is the voltage sensitive gate, and the "internal gate" which is the selectivity filter gate (SFG). Some quantum effects are expected in the SFG due to its small dimensions, which may play an important role in the operation of an ion channel. Here, we examine parameters in a generalized model of HH to see whether any parameter affects the spike generation. Our results indicate that the previously suggested semi-quantum-classical equation proposed by Bernroider and Summhammer (BS) agrees strongly with the HH equation under different conditions and may even provide a better explanation in some cases. We conclude that the BS model can refine the classical HH model substantially.

  12. Grey matter density decreases as well as increases in patients with classic galactosemia: A voxel-based morphometry study.

    Science.gov (United States)

    Timmers, Inge; van der Korput, Lisanne D; Jansma, Bernadette M; Rubio-Gozalbo, M Estela

    2016-10-01

    Brain impairments have been observed in patients with classic galactosemia, an inherited metabolic disorder resulting in a particular neuro-cognitive profile. Neuroimaging studies showed abnormalities such as diffuse white mater (WM) abnormalities and grey matter (GM) atrophy. Our current study analysed grey matter density using voxel-based morphometry (VBM) and compared the brains of eight adolescent patients with classic galactosemia with eight healthy gender- and aged-matched controls. GM density differences were found in several regions. Decreased GM density was found in the patients in the bilateral putamen and bilateral occipital cortex. Increased GM density in the patients, on the other hand, was found in the bilateral inferior frontal and medial prefrontal cortex. The anatomical profile of the abnormalities is in line with the neuro-cognitive profile of patients with classic galactosemia, including motor dysfunction, speech and language difficulties and higher order cognitive problems. Less favourable GM densities in patients (either increased or decreased compared to controls) correlated with younger age, a worse visual working memory performance, and an older age at initiation of the galactose-restricted diet. To conclude, this explorative study is the first to analyse the GM using VBM in this population, and demonstrates a mixed profile of both increased and decreased GM density in these patients.

  13. Ambiguities in Quantizing a Classical System

    CERN Document Server

    Redmount, I H; Young, K; Redmount, Ian; Suen, Wai-Mo; Young, Kenneth

    1999-01-01

    One classical theory, as determined by an equation of motion or set of classical trajectories, can correspond to many unitarily {\\em in}equivalent quantum theories upon canonical quantization. This arises from a remarkable ambiguity, not previously investigated, in the construction of the classical (and hence the quantized) Hamiltonian or Lagrangian. This ambiguity is illustrated for systems with one degree of freedom: An arbitrary function of the constants of motion can be introduced into this construction. For example, the nonrelativistic and relativistic free particles follow identical classical trajectories, but the Hamiltonians or Lagrangians, and the canonically quantized versions of these descriptions, are inequivalent. Inequivalent descriptions of other systems, such as the harmonic oscillator, are also readily obtained.

  14. Study of air masses trajectories during the TRO-pico campaign aiming at studying of the impact of convective overshooting on the stratospheric water budget

    Science.gov (United States)

    Mappe, Irene; Riviere, Emmanuel; Khaykin, Sergey; Ghysels, Mélanie; Stoeffler, Clara; Amarouche, Nadir; Durry, Georges; Held, Gerhard

    2014-05-01

    Water vapor directly affects the climate as greenhouse gas emissions, but also indirectly by the formation of other essential elements of radiative forcing as aerosols, clouds of ice. In addition, water has a significant role in the chemical composition, the balance of ozone and the oxidizing capacity of the atmosphere. Transfers of water vapor in the troposphere to the stratosphere are one of the major scientific challenges in modeling the stratosphere and climate. The TRO-pico small balloon campaign took place in Bauru (22.3 ° S) in southern Brazil during two convective seasons. Its main objective was to study the exchange of water vapor between the upper troposphere and lower stratosphere, and better understand the role of overshooting convection in the moistening of the lower stratosphere and its variability at the local scale to infer a typical impact at a larger scale. Here we focus on the purely convective seasons of the campaign, with a first period in March 2012 and a second in Jan-Feb 2013, during which, in addition to convective tracers measurements (methane, O3…) H2O was intensively sampled by two different in situ hygrometers : Pico-SDLA H2O and FLASH-B. Here we investigated all the measurements gathered close to deep convective events and analyze them in term of potential signature of overshooting convection in the lower stratosphere, to put to the fore possible impact at the wet season time scale. The approach is the use of a trajectory model (HYsplit) running with the GDAS analyses, the different H2O profile from both instruments, echo top from the Bauru S-Band radar highlighting any potential overshoot occurrence in the vicinity of the balloon flight earlier during the day. For each local maximum of H2O, a back trajectory is computed from the balloon position. It is checked if the back trajectory cross an overshooting cell seen by the Bauru radar, and matches it in time and maximum altitude Here we use a total of 8 vertical profiles of H2O from

  15. The trajectory and the related physical and social determinants of body mass index in elementary school children: results from the child and adolescent behaviors in long-term evolution study.

    Science.gov (United States)

    Lin, Li-Ju; Chang, Hsing-Yi; Luh, Dih-Ling; Hurng, Baai-Shyun; Yen, Lee-Lan

    2014-01-01

    This study explored developmental trajectory patterns of BMI and associated factors. Participants included 1,609 students who were followed from age 7 to 12 years. Data collection involved annual self-administered questionnaires and records of height and weight. An ecological model was used to identify the factors associated with BMI trajectories. Group-based trajectory models and multinomial logit models were used in the statistical analysis. There were gender differences in BMI trajectories. Among boys, four BMI trajectories were normal or slightly underweight, persistently normal weight, overweight becoming obese, and persistently obese. Among girls, four BMI trajectories were persistently slightly underweight, persistently normal weight, persistently overweight, and persistently obese. The mean BMI in each trajectory group demonstrated an upward trend over time. In boys, BMI trajectories were significantly associated with after-school exercise, academic performance, family interactions, overweight parents, and father's education level. In girls, BMI trajectories were significantly associated with television viewing or computer use, family interactions, peer interactions, and overweight parents. Children under age 7 years who are already overweight or obese are an important target for interventions. The different factors associated with BMI trajectories can be used for targeting high risk groups.

  16. The Trajectory and the Related Physical and Social Determinants of Body Mass Index in Elementary School Children: Results from the Child and Adolescent Behaviors in Long-Term Evolution Study

    Directory of Open Access Journals (Sweden)

    Li-Ju Lin

    2014-01-01

    Full Text Available This study explored developmental trajectory patterns of BMI and associated factors. Participants included 1,609 students who were followed from age 7 to 12 years. Data collection involved annual self-administered questionnaires and records of height and weight. An ecological model was used to identify the factors associated with BMI trajectories. Group-based trajectory models and multinomial logit models were used in the statistical analysis. There were gender differences in BMI trajectories. Among boys, four BMI trajectories were normal or slightly underweight, persistently normal weight, overweight becoming obese, and persistently obese. Among girls, four BMI trajectories were persistently slightly underweight, persistently normal weight, persistently overweight, and persistently obese. The mean BMI in each trajectory group demonstrated an upward trend over time. In boys, BMI trajectories were significantly associated with after-school exercise, academic performance, family interactions, overweight parents, and father’s education level. In girls, BMI trajectories were significantly associated with television viewing or computer use, family interactions, peer interactions, and overweight parents. Children under age 7 years who are already overweight or obese are an important target for interventions. The different factors associated with BMI trajectories can be used for targeting high risk groups.

  17. Genetic influences on alcohol use behaviors have diverging developmental trajectories: a prospective study among male and female twins.

    Science.gov (United States)

    Meyers, Jacquelyn L; Salvatore, Jessica E; Vuoksimaa, Eero; Korhonen, Tellervo; Pulkkinen, Lea; Rose, Richard J; Kaprio, Jaakko; Dick, Danielle M

    2014-11-01

    Both alcohol-specific genetic factors and genetic factors related to externalizing behavior influence problematic alcohol use. Little is known, however, about the etiologic role of these 2 components of genetic risk on alcohol-related behaviors across development. Prior studies conducted in a male cohort of twins suggest that externalizing genetic factors are important for predicting heavy alcohol use in adolescence, whereas alcohol-specific genetic factors increase in importance during the transition to adulthood. In this report, we studied twin brothers and sisters and brother-sister twin pairs to examine such developmental trajectories and investigate whether sex and cotwin sex effects modify these genetic influences. We used prospective, longitudinal twin data collected between ages 12 and 22 within the population-based FinnTwin12 cohort study (analytic n = 1,864). Our dependent measures of alcohol use behaviors included alcohol initiation (age 12), intoxication frequency (ages 14 and 17), and alcohol dependence criteria (age 22). Each individual's genetic risk of alcohol use disorders (AUD-GR) was indexed by his/her parents' and cotwin's DSM-IV Alcohol Dependence (AD) criterion counts. Likewise, each individual's genetic risk of externalizing disorders (EXT-GR) was indexed with a composite measure of parents' and cotwin's DSM-IV Conduct Disorder and Antisocial Personality Disorder criterion counts. EXT-GR was most strongly related to alcohol use behaviors during adolescence, while AUD-GR was most strongly related to alcohol problems in young adulthood. Further, sex of the twin and sex of the cotwin significantly moderated the associations between genetic risk and alcohol use behaviors across development: AUD-GR influenced early adolescent alcohol use behaviors in females more than in males, and EXT-GR influenced age 22 AD more in males than in females. In addition, the associations of AUD-GR and EXT-GR with intoxication frequency were greater among 14- and

  18. Alcohol Use Trajectories and Problem Drinking over the Course of Adolescence: A Study of North American Indigenous Youth and Their Caretakers

    Science.gov (United States)

    Cheadle, Jacob E.; Whitbeck, Les B.

    2011-01-01

    This study investigated the links between alcohol use trajectories and problem drinking ("Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition" abuse/dependence) using five waves of data from 727 North American Indigenous adolescents between 10 and 17 years from eight reservations sharing a common language and culture.…

  19. WWC Review of the Report "Longitudinal Evaluation of a Scale-up Model for Teaching Mathematics with Trajectories and Technologies." What Works Clearinghouse Single Study Review

    Science.gov (United States)

    What Works Clearinghouse, 2014

    2014-01-01

    The 2012 study, "Longitudinal Evaluation of a Scale-Up Model for Teaching Mathematics with Trajectories and Technologies," examined the effects of "Technology-enhanced, Research-based, Instruction, Assessment, and professional Development (TRIAD)," a math intervention for preschoolers that combines a curriculum, a…

  20. L2 Academic Discourse Socialization through Oral Presentations: An Undergraduate Student's Learning Trajectory in Study Abroad

    Science.gov (United States)

    Kobayashi, Masaki

    2016-01-01

    The present study provides an in-depth, longitudinal account of an undergraduate student's L2 discourse socialization in an academic exchange program in Canada. By invoking Rogoff's (1995) notion of participatory appropriation, this qualitative case study examined an L2 student's task-related strategies and performance as they evolved over time in…

  1. Getting excited: Challenges in quantum-classical studies of excitons in polymeric systems

    CERN Document Server

    Bagheri, Behnaz; Karttunen, Mikko

    2016-01-01

    A combination of classical molecular dynamics (MM/MD) and quantum chemical calculations based on the density functional theory (DFT) was performed to describe conformational properties of diphenylethyne (DPE), methylated-DPE and poly para phenylene ethynylene (PPE). DFT calculations were employed to improve and develop force field parameters for MM/MD simulations. Many-body Green's functions theory within the GW approximation and the Bethe-Salpeter equation were utilized to describe excited states of the systems. Reliability of the excitation energies based on the MM/MD conformations was examined and compared to the excitation energies from DFT conformations. The results show an overall agreement between the optical excitations based on MM/MD conformations and DFT conformations. This allows for calculation of excitation energies based on MM/MD conformations.

  2. AN OPEN LABEL PILOT STUDY TESTING THE ROLE OF CLASSICAL HOMEOPATHY IN CHRONIC ALLERGIC RHINITIS

    Directory of Open Access Journals (Sweden)

    S. Ghosh*, S. Das, M. Mundle Dishari Sengupta, Sk. Intaj Hossain, M. Koley and S. Saha

    2013-04-01

    Full Text Available ABSTRACT: Purpose: The prevalence of allergic rhinitis (AR is increasing at an alarming rate throughout the world. India has an estimated number of 15-20 million patients with allergic bronchial asthma and 30-80% of these suffer from AR. So, AR is considered as a major chronic respiratory disease due to its prevalence, impact on quality of life (QoL, work/school performance and productivity, economic burden and links with asthma. This research aims at testing the role of classical homeopathy in bringing changes in serum immunoglobulin E (IgE level and absolute eosinophil count (primary outcome measures and symptoms score and WHOQOL-BREF score related to AR (secondary outcome measures by comparing the pre-trial and post-trial data.

  3. FAPA mass spectrometry of hydroxychalcones. Comparative studies with classical methods of ionization

    Directory of Open Access Journals (Sweden)

    Smoluch Marek

    2014-06-01

    Full Text Available In this paper we are focused on analysis of hydroxychalcones, i.e. 2’-hydroxychalcone, 3’-hydroxychalcone and 4’-hydroxychalcone, by the Flowing Atmospheric Pressure Afterglow mass spectrometry (FAPA-MS, and on comparison of the obtained data with other classical methods including ESI-MS, APCI, MALDI, and GC/EI-MS. The paper is presenting fragmentation pathways of both positive-, and negative hydroxychalcone ions. Tested compounds were characterized by comparison of the results (signals m/z and relative intensities from the five mass spectrometry techniques, showing very good utility of FAPA method for fast and easy analysis of the low molecular weight compounds. Moreover, FAPA does not require a time-consuming derivatization, nor search for a suitable solvent or matrix, often incompatible with various ion sources.

  4. Studying classical swine fever virus: making the best of a bad virus.

    Science.gov (United States)

    Ji, Wei; Guo, Zhen; Ding, Nai-Zheng; He, Cheng-Qiang

    2015-02-01

    Classical swine fever (CSF) is a highly contagious and often fatal disease that affects domestic pigs and wild boars. Outbreak of CSF can cause heavy economic losses to the pig industry. The strategies to prevent, control and eradicate CSF disease are based on containing the disease through a systematic prophylactic vaccination policy and a non-vaccination stamping-out policy. The quest for prevention, control and eradication of CSF has moved research forward in academia and industry, and has produced noticeable advances in understanding fundamental aspects of the virus replication mechanisms, virulence, and led to the development of new vaccines. In this review we summarize recent progress in CSFV epidemiology, molecular features of the genome and proteome, the molecular basis of virulence, and the development of anti-virus technologies.

  5. Ground Based Studies of Gas-Liquid Flows in Microgravity Using Learjet Trajectories

    Science.gov (United States)

    Bousman, W. S.; Dukler, A. E.

    1994-01-01

    A 1.27 cm diameter two phase gas-liquid flow experiment has been developed with the NASA Lewis Research Center to study two-phase flows in microgravity. The experiment allows for the measurement of void fraction, pressure drop, film thickness and bubble and wave velocities as well as for high speed photography. Three liquids were used to study the effects of liquid viscosity and surface tension, and flow pattern maps are presented for each. The experimental results are used to develop mechanistically based models to predict void fraction, bubble velocity, pressure drop and flow pattern transitions in microgravity.

  6. 10-year trajectories of depressive symptoms and risk of dementia: a population-based study

    NARCIS (Netherlands)

    S.S. Mirza (Saira); F.J. Wolters (Frank J.); S.A. Swanson (Sonja A.); P.J. Koudstaal (Peter Jan); A. Hofman (Albert); H.W. Tiemeier (Henning); M.K. Ikram (Kamran)

    2016-01-01

    textabstractBackground Late-life depressive symptoms have been extensively studied for their relationship with incident dementia, but have been typically assessed at a single timepoint. Such an approach neglects the course of depression, which, given its remitting and relapsing nature, might provide

  7. Intrauterine Cannabis Exposure Affects Fetal Growth Trajectories: The Generation R Study

    Science.gov (United States)

    El Marroun, Hanan; Tiemeier, Henning; Steegers, Eric A. P.; Jaddoe, Vincent W. V.; Hofman, Albert; Verhulst, Frank C.; van den Brink, Wim; Huizink, Anja C.

    2009-01-01

    Objective: Cannabis is the most commonly consumed illicit drug among pregnant women. Intrauterine exposure to cannabis may result in risks for the developing fetus. The importance of intrauterine growth on subsequent psychological and behavioral child development has been demonstrated. This study examined the relation between maternal cannabis use…

  8. Intrauterine Cannabis Exposure Affects Fetal Growth Trajectories: The Generation R Study

    Science.gov (United States)

    El Marroun, Hanan; Tiemeier, Henning; Steegers, Eric A. P.; Jaddoe, Vincent W. V.; Hofman, Albert; Verhulst, Frank C.; van den Brink, Wim; Huizink, Anja C.

    2009-01-01

    Objective: Cannabis is the most commonly consumed illicit drug among pregnant women. Intrauterine exposure to cannabis may result in risks for the developing fetus. The importance of intrauterine growth on subsequent psychological and behavioral child development has been demonstrated. This study examined the relation between maternal cannabis use…

  9. Motion in action: A study of second graders' trajectories of experience during guided inquiry science instruction

    Science.gov (United States)

    Hapgood, Susanna Elizabeth

    This interpretive case study describes a 10-day inquiry science program of study of motion down inclined planes during which a class of 21 second graders investigated scientific relationships such as mass and speed, speed and momentum, and mass and momentum via both text-based experiences ("second-hand investigations") and hands-on materials-based experiments ("first-hand investigations"). Data sources included over 11 hours of videotaped instruction in addition to children's written work, class-generated artifacts, and paper-and-pencil pre- and posttests. Content analyses informed by both sociocultural and developmental perspectives revealed that, in addition to a significant increase in pre- to posttest scores, children in the class engaged in several processes integral to inquiry, namely, (a) using data as evidence, (b) evaluating investigative procedures, and (c) making sense of multiple forms of representations. In addition, the study describes the range of and shifts in children's ideas about scientific relationships fundamental to developing an understanding of motion. Many children were observed to make causal attributions involving a relationship between two variables, such as the mass and momentum of a ball rolling down a ramp. Discussed are mediating factors such as the teacher's role in scaffolding the class's investigations and features of the innovative "scientists' notebook" texts, which were integral to the instruction. Also presented is evidence of first-hand and second-hand investigations working in concert to provide the elementary school students with rich opportunities to learn and to express their developing understandings of scientific ideas. This study provides a rare glimpse of primary-grade inquiry-based science instruction within a classroom context.

  10. Do dietary trajectories between infancy and toddlerhood influence IQ in childhood and adolescence? Results from a prospective birth cohort study.

    Directory of Open Access Journals (Sweden)

    Lisa G Smithers

    Full Text Available We examined whether trajectories of dietary patterns from 6 to 24 months of age are associated with intelligence quotient (IQ in childhood and adolescence.Participants were children enrolled in a prospective UK birth cohort (n = 7,652 who had IQ measured at age 8 and/or 15 years. Dietary patterns were previously extracted from questionnaires when children were aged 6, 15 and 24 months using principal component analysis. Dietary trajectories were generated by combining scores on similar dietary patterns across each age, using multilevel mixed models. Associations between dietary trajectories and IQ were examined in generalized linear models with adjustment for potential confounders.Four dietary pattern trajectories were constructed from 6 to 24 months of age and were named according to foods that made the strongest contribution to trajectory scores; Healthy (characterised by breastfeeding at 6 months, raw fruit and vegetables, cheese and herbs at 15 and 24 months; Discretionary (biscuits, chocolate, crisps at all ages, Traditional (meat, cooked vegetables and puddings at all ages and, Ready-to-eat (use of ready-prepared baby foods at 6 and 15 months, biscuits, bread and breakfast cereals at 24 months. In fully-adjusted models, a 1 SD change in the Healthy trajectory was weakly associated with higher IQ at age 8 (1.07 (95%CI 0.17, 1.97 but not 15 years (0.49 (-0.28, 1.26. Associations between the Discretionary and Traditional trajectories with IQ at 8 and 15 years were as follows; Discretionary; 8 years -0.35(-1.03, 0.33, 15 years -0.73(-1.33, -0.14 Traditional; 8 years -0.19(-0.71, 0.3315 years -0.41(-0.77, -0.04. The Ready-to-eat trajectory had no association with IQ at either age (8 years 0.32(-4.31, 4.95, 15 years 1.11(-3.10, 5.33.The Discretionary and Traditional dietary pattern trajectories from 6 to 24 months of age, over the period when food patterns begin to emerge, are weakly associated with IQ in adolescence.

  11. Trajectories of abstinence-induced Internet gaming withdrawal symptoms: A prospective pilot study

    Directory of Open Access Journals (Sweden)

    Dean Kaptsis

    2016-12-01

    Full Text Available Internet Gaming Disorder (IGD is positioned in the appendix of the DSM-5 as a condition requiring further study. The IGD criteria refer to withdrawal symptoms, including irritability, anxiety, or sadness, that follow cessation of Internet gaming (APA, 2013. The aim of this study was to prospectively examine the nature of Internet gaming withdrawal symptoms, if they occur, under gaming abstinence conditions. This study employed a repeated-measures protocol to examine the cognitive-affective reactions of participants undertaking an 84-h Internet gaming abstinence period. The sample included individuals who met the IGD criteria as well as those who regularly played Internet games but did not meet the IGD criteria. Outcome variables included affect (positive and negative, psychological distress (depression, anxiety, stress, and Internet gaming withdrawal symptoms (craving/urge, thoughts about gaming, inability to resist gaming. A total of 24 participants (Mage = 24.6 years, SD = 5.8 were recruited from online gaming communities, and completed a series of online surveys before, during, and after abstaining from Massively Multiplayer Online (MMO games. Both the IGD group and the non-IGD group experienced an abstinence-induced decline in withdrawal symptomatology, negative affect, and psychological distress. The IGD group experienced its largest decline in withdrawal symptomatology within the first 24 h of abstinence. These preliminary data suggest that gaming withdrawal symptoms may follow, at least initially, negative linear and quadratic trends. Further prospective work in larger samples involving longer periods of abstinence is required to verify and expand upon these observations.

  12. Trajectories of growth and symptoms of attention-deficit/hyperactivity disorder in children: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Kajantie Eero

    2011-10-01

    Full Text Available Abstract Background Empirical evidence suggests that prenatal growth is associated with attention deficit/hyperactivity disorder (ADHD and its symptoms. Data on the importance of postnatal growth is, however scanty. We studied whether pre- and postnatal growth up to 56 months is associated with symptoms of ADHD in children. Method A longitudinal regional birth cohort study comprising 893 children followed up to 56 months. The associations between pre- and postnatal growth and parent-rated ADHD symptoms of the child were analyzed with multiple linear regression analyses and repeated-measures analyzes of covariance. Results Children born lighter, thinner, shorter, and with a smaller head circumference, adjusted for length of gestation, received higher parent-rated ADHD symptoms scores at 56 months. Further, smaller head circumference throughout the period of growth from birth up to 56 months was related to higher ADHD symptoms scores. The associations changed only little after adjusting for several pre- and neonatal factors. The associations were not modified by sex and there were no evidence of non-linear associations. Conclusions Slower prenatal growth in weight, body-mass index, length, and head circumference may pose a risk for higher ADHD symptoms in childhood. The consistently smaller head circumference from birth up to 56 months characterizing children with higher ADHD symptoms may point to a lack of catch-up growth in head circumference in childhood as a predisposing factor.

  13. Study of the pion trajectory in the photoproduction of leading neutrons at HERA

    CERN Document Server

    Chekanov, S; Abt, I; Adamczyk, L; Adamus, M; Adler, V; Aghuzumtsyan, G; Antonioli, P; Antonov, A; Arneodo, M; Bailey, D S; Bamberger, A; Barakbaev, A N; Barbagli, G; Barbi, M; Bari, G; Barreiro, F; Bartsch, D; Basile, M; Behrens, U; Bellagamba, L; Bellan, P M; Benen, A; Bertolin, A; Bhadra, S; Bloch, I; Bold, T; Boos, E G; Borras, K; Boscherini, D; Brock, I; Brook, N H; Brugnera, R; Brümmer, N; Bruni, A; Bruni, G; Bussey, P J; Butterworth, J M; Büttner, C; Bylsma, B; Caldwell, A; Capua, M; Cara Romeo, G; Carli, T; Carlin, R; Catterall, C D; Chiochia, V; Chwastowski, J; Ciborowski, J; Ciesielski, R; Cifarelli, Luisa; Cindolo, F; Cloth, P; Cole, J E; Collins-Tooth, C; Contin, A; Cooper-Sarkar, A M; Coppola, N; Cormack, C; Corradi, M; Corriveau, F; Costa, M; Cottrell, A; D'Agostini, Giulio; Dal Corso, F; Danilov, P; Dannheim, D; De Pasquale, S; Dementiev, R K; Derrick, M; Devenish, R C E; Dhawan, S; Dobur, D; Dolgoshein, B A; Doyle, A T; Drews, G; Durkin, L S; Dusini, S; Eisenberg, Y; Ermolov, P F; Eskreys, Andrzej; Everett, A; Ferrando, J; Ferrero, M I; Figiel, J; Filges, D; Foster, B; Foudas, C; Fourletov, S; Fourletova, J; Fricke, U; Fusayasu, T; Gabareen, A; Galas, A; Gallo, E; Garfagnini, A; Geiser, A; Genta, C; Gialas, I; Giusti, P; Gladilin, L K; Gladkov, D; Glasman, C; Gliga, S; Goers, S; Goncalo, R; González, O; Gosau, T; Göttlicher, P; Grabowska-Bold, I; Grigorescu, G; Grijpink, S; Grzelak, G; Gutsche, O; Gwenlan, C; Haas, T; Hain, W; Hall-Wilton, R; Hamatsu, R; Hamilton, J; Hanlon, S; Hart, J C; Hartmann, H; Hartner, G; Heaphy, E A; Heath, G P; Helbich, M; Heusch, C A; Hilger, E; Hillert, S; Hirose, T; Hochman, D; Holm, U; Horn, C; Iacobucci, G; Iga, Y; Inuzuka, M; Irrgang, P; Jakob, H P; Jones, T W; Kagawa, S; Kahle, B; Kaji, H; Kananov, S; Karshon, M; Karstens, F; Kataoka, M; Katkov, I I; Kcira, D; Keramidas, A; Khein, L A; Kim, J Y; Kind, O; Kisielewska, D; Kitamura, S; Koffeman, E; Kohno, T; Kooijman, P; Koop, T; Korzhavina, I A; Kotanski, A; Kötz, U; Kowal, A M; Kowal, M; Kowalski, H; Kramberger, G; Kreisel, A; Krumnack, N; Kuze, M; Kuzmin, V A; Labarga, L; Labes, H; Lainesse, J; Lammers, S; Lelas, D; Levchenko, B B; Levy, A; Li, L; Lightwood, M S; Lim, H; Lim, I T; Limentani, S; Ling, T Y; Liu, X; Löhr, B; Lohrmann, E; Loizides, J H; Long, K R; Longhin, A; Lukina, O Yu; Luzniak, P; Ma, K J; Maddox, E; Magill, S; Mankel, R; Margotti, A; Marini, G; Martin, J F; Mastroberardino, A; Matsuzawa, K; Mattingly, M C K; McCubbin, N A; Melzer-Pellmann, I A; Menary, S R; Metlica, F; Meyer, U; Miglioranzi, S; Milite, M; Mirea, A; Monaco, V; Montanari, A; Musgrave, B; Nagano, K; Namsoo, T; Nania, R; Nguyen, C N; Nigro, A; Ning, Y; Notz, D; Nowak, R J; Nuncio, A E; Oh, B Y; Olkiewicz, K; Pac, M Y; Padhi, S; Palmonari, F; Parenti, A; Park, I H; Patel, S; Paul, E; Pavel, Usan; Pawlak, J M; Pelfer, P G; Pellegrino, A; Pesci, A; Piotrzkowski, K; Plucinsky, P P; Pokrovskiy, N S; Polini, A; Posocco, M; Proskuryakov, A S; Przybycien, M B; Rautenberg, J; Raval, A; Reeder, D D; Ren, Z; Renner, R; Repond, J; Rinaldi, L; Riveline, U; Robins, S; Rosin, M; Ruspa, M; Ryan, P; Sacchi, R; Salehi, H; Sartorelli, G; Savin, A A; Saxon, D H; Schagen, S; Schioppa, M; Schlenstedt, S; Schleper, P; Schmidke, W B; Schneekloth, U; Schörner-Sadenius, T; Sciulli, F; Shcheglova, L M; Skillicorn, I O; Slominski, W; Smith, W H; Soares, M; Solano, A; Son, D; Sosnovtsev, V V; Stairs, D G; Stanco, L; Standage, J; Stifutkin, A; Stonjek, S; Stopa, P; Stösslein, U; Straub, P B; Suchkov, S; Susinno, G; Suszycki, L; Sutiak, J; Sutton, M R; Sztuk, J; Szuba, D; Szuba, J; Tandler, J; Tapper, A D; Targett-Adams, C; Tassi, E; Tawara, T; Terron, J; Tiecke, H G; Tokushuku, K; Tsurugai, T; Turcato, M; Tymieniecka, T; Ukleja, A; Ukleja, J; Vázquez, M; Vlasov, N N; Voss, K C; Walczak, R; Walsh, R; Wang, M; Whitmore, J J; Wichmann, K; Wick, K; Wiggers, L; Wills, H H; Wing, M; Wolf, G; Yamada, S; Yamashita, T; Yamazaki, Y; Yoshida, R; Youngman, C; Zambrana, M; Zawiejski, L; Zeuner, W; Zhautykov, B O; Zichichi, A; Ziegler, A; Zotkin, S A; De Favereau, J; De Wolf, E; Del Peso, J

    2004-01-01

    Energetic neutrons produced in ep collisions at HERA have been studied with the ZEUS detector in the photoproduction regime at a mean photon-proton center-of-mass energy of 220 GeV. The neutrons carry a large fraction 0.6 < x_L < 0.925 of the incoming proton energy and the four-momentum-transfer squared at the proton-neutron vertex is small, |t| < 0.425 GeV^2. The x_L distribution of the neutrons is measured in bins of t. The (1-x_L) distributions in the bins of t studied satisfy a power law dN/dx_L ~ (1-x_L)^a(t), with the powers a(t) following a linear function of t: a(t) = 1.08 +/- 0.08(stat.) +0.15/-0.28(syst.) - [2.78 +/- 0.32(stat.) +0.51/-0.47(syst.) GeV^-2]t. This result is consistent with the expectations of pion-exchange models, in which the incoming proton fluctuates to a neutron-pion state and the electron interacts with the pion.

  14. Trajectory of phantom limb pain relief using mirror therapy: Retrospective analysis of two studies.

    Science.gov (United States)

    Griffin, Sarah C; Curran, Sean; Chan, Annie W Y; Finn, Sacha B; Baker, Chris I; Pasquina, Paul F; Tsao, Jack W

    2017-04-01

    Research indicates that mirror therapy reduces phantom limb pain (PLP). Objectives were to determine when mirror therapy works in those who respond to treatment, the relevance of baseline PLP to when pain relief occurs, and what pain symptoms respond to mirror therapy. Data from two independent cohorts with unilateral lower limb amputation were analyzed for this study (n=33). Mirror therapy consisted of 15-min sessions in which amputees performed synchronous movements of the phantom and intact legs/feet. PLP was measured using a visual analogue scale and the Short-Form McGill Pain Questionnaire. The severity of PLP at the beginning of treatment predicted when pain relief occurred. Those with low baseline PLP experienced a reduction (pMirror therapy reduced throbbing, shooting, stabbing, sharp, cramping, aching, tender, splitting, tiring/exhausting, and punishing-cruel pain symptoms. The degree of PLP at baseline predicts when mirror therapy relieves pain. This article indicates that the degree of baseline PLP affects when mirror therapy relieves pain: relief occurs by session 7 in patients with low PLP but by session 21 in patients with high PLP. Clinicians should anticipate slower pain relief in patients who begin treatment with high levels of pain. ClinicalTrials.gov numbers:NCT00623818 and NCT00662415. Copyright © 2017 Scandinavian Association for the Study of Pain. All rights reserved.

  15. A Study on Decoding Models for the Reconstruction of Hand Trajectories from the Human Magnetoencephalography

    Directory of Open Access Journals (Sweden)

    Hong Gi Yeom

    2014-01-01

    Full Text Available Decoding neural signals into control outputs has been a key to the development of brain-computer interfaces (BCIs. While many studies have identified neural correlates of kinematics or applied advanced machine learning algorithms to improve decoding performance, relatively less attention has been paid to optimal design of decoding models. For generating continuous movements from neural activity, design of decoding models should address how to incorporate movement dynamics into models and how to select a model given specific BCI objectives. Considering nonlinear and independent speed characteristics, we propose a hybrid Kalman filter to decode the hand direction and speed independently. We also investigate changes in performance of different decoding models (the linear and Kalman filters when they predict reaching movements only or predict both reach and rest. Our offline study on human magnetoencephalography (MEG during point-to-point arm movements shows that the performance of the linear filter or the Kalman filter is affected by including resting states for training and predicting movements. However, the hybrid Kalman filter consistently outperforms others regardless of movement states. The results demonstrate that better design of decoding models is achieved by incorporating movement dynamics into modeling or selecting a model according to decoding objectives.

  16. Gut microbiota trajectory in patients with severe burn: A time series study.

    Science.gov (United States)

    Wang, Xinying; Yang, Jianbo; Tian, Feng; Zhang, Li; Lei, Qiucheng; Jiang, Tingting; Zhou, Jihong; Yuan, Siming; Wang, Jun; Feng, Zhijian; Li, Jieshou

    2017-08-12

    This time series experiments aimed to investigate the dynamic change of gut microbiomes after severe burn and its association with enteral nutrition (EN). Seven severely burned patients who suffered from a severe metal dust explosion injury were recruited in this study. The dynamic changes of gut microbiome of fecal samples at six time points (1-3days, 2, 3, 4, 5 and 6weeks after severe burn) were detected using 16S ribosomal RNA pyrosequencing technology. Following the post-burn temporal order, gut microbiota dysbiosis was detected in the gut microbiome after severe burn, then it was gradually resolved. The bio-diversity of gut bacteria was initially decreased, and then returned to normal level. In addition, at the early stage (from 2 to 4weeks), the majority of those patients' gut microbiome were opportunistic pathogen genus, Enterococcus and Escherichia; while at the end of this study, the majority was a beneficial genus, Bacteroides. EN can promote the recovery of gut microbiota, especially in EN well-tolerated patients. Severe burn injury can cause a dramatic dysbiosis of gut microbiota. A trend of enriched beneficial bacteria and diminished opportunistic pathogen bacteria may serve as prognosis microbiome biomarkers of severe burn patients. Copyright © 2017. Published by Elsevier Inc.

  17. Collective variables for the study of long-time kinetics from molecular trajectories: theory and methods.

    Science.gov (United States)

    Noé, Frank; Clementi, Cecilia

    2017-04-01

    Collective variables are an important concept to study high-dimensional dynamical systems, such as molecular dynamics of macromolecules, liquids, or polymers, in particular to define relevant metastable states and state-transition or phase-transition. Over the past decade, a rigorous mathematical theory has been formulated to define optimal collective variables to characterize slow dynamical processes. Here we review recent developments, including a variational principle to find optimal approximations to slow collective variables from simulation data, and algorithms such as the time-lagged independent component analysis. Using these concepts, a distance metric can be defined that quantifies how slowly molecular conformations interconvert. Extensions and open questions are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Growing up with Asperger’s syndrome: developmental trajectory of autobiographical memory (a clinical case study

    Directory of Open Access Journals (Sweden)

    Laetitia eBon

    2013-01-01

    Full Text Available Autobiographical memory and social cognition share common properties and both are affected in autism spectrum disorders (ASD. So far, most of the scant research in ASD has concerned adults, systematically reporting impairment of the episodic component. The only study to be conducted with children concluded that they have poorer personal semantic knowledge than typical developing children. The present study explores the development of both components of autobiographical memory in an 8-year-old boy diagnosed with Asperger’s syndrome, based on three examinations in 2007, 2008 and 2010. On each occasion, he underwent a general neuropsychological assessment including theory of mind tasks, and a specially-designed autobiographical memory task allowing us to test both the semantic and the episodic components for three lifetime periods (current year, previous year and earlier years. We observed difficulties in strategic retrieval and theory of mind, with a significant improvement between the second and third examinations. Regarding autobiographical memory, different patterns of performance were noted in all three examinations: 1 relative preservation of current-year personal knowledge, but impairment for the previous and earlier years, and 2 impairment of episodic memory for the current and previous year, but performances similar to those of controls for the earlier years. The first pattern can be explained by abnormal forgetting and by the semanticization mechanism, which needs verbal communication and social interaction to be efficient. The second pattern suggests that the development of episodic memory only reached the stage of event memory. This term refers to memory for personal events lacking in details or spatiotemporal specificity, and is usually observed in children younger than 5. We conclude that the abnormal functioning of social cognition in ASD, encompassing social and personal points of view, has an impact on both components of

  19. Trajectories of legitimate peripheral participation: Ethnographic case studies of learning ecology

    Science.gov (United States)

    Bowen, Gervase Michael Reynolds

    1999-09-01

    Current reform documents in education call for elementary and high school students to engage in "authentic" scientific practices. In the past several years a number of authors have suggested that science education research and curriculum development could benefit from insights gained by research in the social studies of science that documents and theorizes science as it is actually done. Yet, although practices of laboratory science are well understood and provide a foundation from which educational practices could be drawn, little is known about the practices of the science disciplines which deal with field research and how people are enculturated into those practices. This dissertation is constituted by a series of research papers on different (although inter-related) topics, in which I examine the enculturation into the practices of field ecology and the world-view that is associated with that enculturation. To better understand the practices of field ecology and how they develop, I conducted several projects: (i) a video ethnography of a second-year university ecology class and observations on research experiences undergraduates experience; (ii) ethnographic research with ecologists conducting field research; (iii) observations of graduate student and professional ecologists as they participated in conferences, engaged in interaction in their laboratory and social settings, and presented/discussed their findings in various settings; (iv) interviews with graduate student and professional ecologists discussing their field research experiences; (v) videotaped interviews with practicing researchers and under/graduate science and non-science students as they interpreted various ecology-related inscriptions; (vi) an analysis of the inscriptions and textual information present in the various texts (textbooks and journals) used to teach students about ecology; and, (vii) observations of elementary school students engaged in practices congruent with those of field

  20. Investigation of scaling properties of a thin current sheet by means of particle trajectories study

    CERN Document Server

    Sasunov, Yu L; Alexeev, I I; Belenkaya, E S; Semenov, V S; Kubyshkin, I V; Mingalev, O V

    2015-01-01

    A thin current sheet (TCS), with the width of an order of thermal proton gyroradius, appears a fundamental physical object which plays an important role in structuring of major magnetospheric current systems (magnetotail, magnetodisk, etc.). The TCSs are nowadays under extensive study by means of space missions and theoretical models. We consider a simple model of the TCS separating two half-spaces occupied by a homogenous magnetic field of opposite sign tangential to the TCS; a small normal component of the magnetic field is prescribed. An analytical solution for the electric current and plasma density in the close vicinity of the TCS has been obtained and compared with numerical simulation. The number density and the electric current profiles have two maxima each. The characteristic spatial scale $z_S$ of the maxima location was investigated as a function of initial pitch-angle of an incoming charge particle. The effect of the thermal dispersion of the incoming proton beam have been taken into consideration...

  1. Growth Type and Functional Trajectories: An Empirical Study of Urban Expansion in Nanjing, China.

    Science.gov (United States)

    Chen, Jianglong; Gao, Jinlong; Yuan, Feng

    2016-01-01

    Drawing upon the Landsat satellite images of Nanjing from 1985, 1995, 2001, 2007, and 2013, this paper integrates the convex hull analysis and common edge analysis at double scales, and develops a comprehensive matrix analysis to distinguish the different types of urban land expansion. The results show that Nanjing experienced rapid urban expansion, dominated by a mix of residential and manufacturing land from 1985 to 2013, which in turn has promoted Nanjing's shift from a compact mononuclear city to a polycentric one. Spatial patterns of three specific types of growth, namely infilling, extension, and enclave were quite different in four consecutive periods. These patterns result primarily from the existing topographic constraints, as well as government-oriented urban planning and policies. By intersecting the function maps, we also reveal the functional evolution of newly-developed urban land. Moreover, both self-enhancing and mutual promotion of the newly developed functions are surveyed over the last decade. Our study confirms that the integration of a multi-scale method and multi-perspective analysis, such as the spatiotemporal patterns and functional evolution, helps us to better understand the rapid urban growth in China.

  2. Service Use and Unmet Needs in Youth Suicide: A Study of Trajectories

    Science.gov (United States)

    Renaud, Johanne; Séguin, Monique; Lesage, Alain D; Marquette, Claude; Choo, Bettina; Turecki, Gustavo

    2014-01-01

    Objective: While 90% of suicide victims have suffered from mental health disorders, less than one-half are in contact with a mental health professional in the year preceding their death. Service use in the last year of life of young suicide victims and control subjects was studied in Quebec. We wanted to determine what kinds of health care services were needed and if they were actually received by suicide victims. Method: We recruited 67 consecutive suicide victims and 56 matched living control subjects (aged 25 years and younger). We evaluated subjects’ psychopathological profile and determined which services would have been indicated by conducting a needs assessment. We then compared this with what services were actually received. Results: Suicide victims were more likely than living control subjects to have a psychiatric diagnosis. They were most in need of services to address substance use disorder, depression, interpersonal distress, and suicide-related problems. There were significant deficits in the domains of coordination and continuity of care, mental health promotion and training, and governance. Conclusions: Our results show that we need to urgently take action to address these identified deficits to prevent further loss of life in our young people. PMID:25565685

  3. Growth Type and Functional Trajectories: An Empirical Study of Urban Expansion in Nanjing, China.

    Directory of Open Access Journals (Sweden)

    Jianglong Chen

    Full Text Available Drawing upon the Landsat satellite images of Nanjing from 1985, 1995, 2001, 2007, and 2013, this paper integrates the convex hull analysis and common edge analysis at double scales, and develops a comprehensive matrix analysis to distinguish the different types of urban land expansion. The results show that Nanjing experienced rapid urban expansion, dominated by a mix of residential and manufacturing land from 1985 to 2013, which in turn has promoted Nanjing's shift from a compact mononuclear city to a polycentric one. Spatial patterns of three specific types of growth, namely infilling, extension, and enclave were quite different in four consecutive periods. These patterns result primarily from the existing topographic constraints, as well as government-oriented urban planning and policies. By intersecting the function maps, we also reveal the functional evolution of newly-developed urban land. Moreover, both self-enhancing and mutual promotion of the newly developed functions are surveyed over the last decade. Our study confirms that the integration of a multi-scale method and multi-perspective analysis, such as the spatiotemporal patterns and functional evolution, helps us to better understand the rapid urban growth in China.

  4. Design study of double-layer beam trajectory accelerator based on the Rhodotron structure

    Science.gov (United States)

    Jabbari, Iraj; Poursaleh, Ali Mohammad; Khalafi, Hossein

    2016-08-01

    In this paper, the conceptual design of a new structure of industrial electron accelerator based on the Rhodotron accelerator is presented and its properties are compared with those of Rhodotron-TT200 accelerator. The main goal of this study was to reduce the power of RF system of accelerator at the same output electron beam energy. The main difference between the new accelerator structure with the Rhodotron accelerator is the length of the coaxial cavity that is equal to the wavelength at the resonant frequency. Also two sets of bending magnets were used around the acceleration cavity in two layers. In the new structure, the beam crosses several times in the coaxial cavity by the bending magnets around the cavity at the first layer and then is transferred to the second layer using the central bending magnet. The acceleration process in the second layer is similar to the first layer. Hence, the energy of the electron beam will be doubled. The electrical power consumption of the RF system and magnet system were calculated and simulated for the new accelerator structure and TT200. Comparing the calculated and simulated results of the TT200 with those of experimental results revealed good agreement. The results showed that the overall electrical power consumption of the new accelerator structure was less than that of the TT200 at the same energy and power of the electron beam. As such, the electrical efficiency of the new structure was improved.

  5. Design study of double-layer beam trajectory accelerator based on the Rhodotron structure

    Energy Technology Data Exchange (ETDEWEB)

    Jabbari, Iraj, E-mail: i_jabbari@ast.ui.ac.ir [Department of Nuclear Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 8174673441 (Iran, Islamic Republic of); Poursaleh, Ali Mohammad [Department of Nuclear Engineering, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan 8174673441 (Iran, Islamic Republic of); Central Iran Research Complex, NSTRI, Yazd (Iran, Islamic Republic of); Khalafi, Hossein [Central Iran Research Complex, NSTRI, Yazd (Iran, Islamic Republic of)

    2016-08-21

    In this paper, the conceptual design of a new structure of industrial electron accelerator based on the Rhodotron accelerator is presented and its properties are compared with those of Rhodotron-TT200 accelerator. The main goal of this study was to reduce the power of RF system of accelerator at the same output electron beam energy. The main difference between the new accelerator structure with the Rhodotron accelerator is the length of the coaxial cavity that is equal to the wavelength at the resonant frequency. Also two sets of bending magnets were used around the acceleration cavity in two layers. In the new structure, the beam crosses several times in the coaxial cavity by the bending magnets around the cavity at the first layer and then is transferred to the second layer using the central bending magnet. The acceleration process in the second layer is similar to the first layer. Hence, the energy of the electron beam will be doubled. The electrical power consumption of the RF system and magnet system were calculated and simulated for the new accelerator structure and TT200. Comparing the calculated and simulated results of the TT200 with those of experimental results revealed good agreement. The results showed that the overall electrical power consumption of the new accelerator structure was less than that of the TT200 at the same energy and power of the electron beam. As such, the electrical efficiency of the new structure was improved.

  6. Identifying patients with advanced chronic conditions for a progressive palliative care approach: a cross-sectional study of prognostic indicators related to end-of-life trajectories

    Science.gov (United States)

    Amblàs-Novellas, J; Murray, S A; Espaulella, J; Martinez-Muñoz, M; Blay, C; Gómez-Batiste, X

    2016-01-01

    Objectives 2 innovative concepts have lately been developed to radically improve the care of patients with advanced chronic conditions (PACC): early identification of palliative care (PC) needs and the 3 end-of-life trajectories in chronic illnesses (acute, intermittent and gradual dwindling). It is not clear (1) what indicators work best for this early identification and (2) if specific clinical indicators exist for each of these trajectories. The objectives of this study are to explore these 2 issues. Setting 3 primary care services, an acute care hospital, an intermediate care centre and 4 nursing homes in a mixed urban–rural district in Barcelona, Spain. Participants 782 patients (61.5% women) with a positive NECPAL CCOMS-ICO test, indicating they might benefit from a PC approach. Outcome measures The characteristics and distribution of the indicators of the NECPAL CCOMS-ICO tool are analysed with respect to the 3 trajectories and have been arranged by domain (functional, nutritional and cognitive status, emotional problems, geriatric syndromes, social vulnerability and others) and according to their static (severity) and dynamic (progression) properties. Results The common indicators associated with early end-of-life identification are functional (44.3%) and nutritional (30.7%) progression, emotional distress (21.9%) and geriatric syndromes (15.7% delirium, 11.2% falls). The rest of the indicators showed differences in the associations per illness trajectories (ppalliative approach. PMID:27645556

  7. A Comparative Study on Cancer Prevention Principles Between Iranian Traditional Medicine and Classic Medicine.

    Science.gov (United States)

    Zeinalian, Mehrdad; Eshaghi, Mehdi; Sharbafchi, Mohammad Reza; Naji, Homayoun; Marandi, Sayed Mohammad Masoud; Asgary, Sedigheh

    2016-01-01

    Cancer is one of the three main causes of mortality in most human communities whose prevalence is being increased. A significant part of health budget in all countries has been allocated to treat the cancer, which is incurable in many cases. It has led the global health attitude to cancer prevention. Many cancer-related risk factors have been identified for which preventive recommendations have been offered by international organizations such as World Health Organization. Some of the most important of these risk factors are smoking and alcohol consumption, hypercaloric and low-fiber diet, obesity, inactivity, environmental and industrial pollution, some viral infections, and hereditary factors. Exact reviewing of Iranian-Islamic traditional medicine (IITM) resources determines that preventive rules, which named as six essential rules (Sitteh-e-Zarurieah) are abundantly found, including all identified cancer-related risk factors. These preventive rules are: Air (Hava), body movement and repose, sleep and wakefulness, food and drink, evacuation and retention, and mental movement and repose (A'raz-e-Nafsani). The associated risk factors in classic medicine are: Smoking and air pollution, sedentary life, sleep disturbance, improper nutrition and alcohol, chronic constipation, and psychoneurotic stresses. Moreover, these rules are comprehensive enough to include many of the other harmful health-related factors whose roles have been confirmed in the occurrence of different diseases, except cancer. Apparently, cancer prevention in Iran would be more successful if the sextet necessary rules of IITM are promoted among the populations and health policy makers.

  8. A comparative study on cancer prevention principles between Iranian traditional medicine and classic medicine

    Directory of Open Access Journals (Sweden)

    Mehrdad Zeinalian

    2016-01-01

    Full Text Available Cancer is one of the three main causes of mortality in most human communities whose prevalence is being increased. A significant part of health budget in all countries has been allocated to treat the cancer, which is incurable in many cases. It has led the global health attitude to cancer prevention. Many cancer-related risk factors have been identified for which preventive recommendations have been offered by international organizations such as World Health Organization. Some of the most important of these risk factors are smoking and alcohol consumption, hypercaloric and low-fiber diet, obesity, inactivity, environmental and industrial pollution, some viral infections, and hereditary factors. Exact reviewing of Iranian-Islamic traditional medicine (IITM resources determines that preventive rules, which named as six essential rules (Sitteh-e-Zarurieah are abundantly found, including all identified cancer-related risk factors. These preventive rules are: Air (Hava, body movement and repose, sleep and wakefulness, food and drink, evacuation and retention, and mental movement and repose (A′raz-e-Nafsani. The associated risk factors in classic medicine are: Smoking and air pollution, sedentary life, sleep disturbance, improper nutrition and alcohol, chronic constipation, and psychoneurotic stresses. Moreover, these rules are comprehensive enough to include many of the other harmful health-related factors whose roles have been confirmed in the occurrence of different diseases, except cancer. Apparently, cancer prevention in Iran would be more successful if the sextet necessary rules of IITM are promoted among the populations and health policy makers.

  9. Intramolecular tautomerisation and the conformational variability of some classical mutagens – cytosine derivatives: quantum chemical study

    Directory of Open Access Journals (Sweden)

    Hovorun D. M.

    2011-04-01

    Full Text Available Aim. To determine the lifetime of the mutagenic cytosine derivatives through the investigation of the physicochemical mechanisms of their intramolecular proton transfer. Methods. Non-empirical quantum chemistry, the analysis of the electron density by means of Bader’s atoms in molecules (AIM theory and physicochemical kinetics were used. Results. It is shown that the modification of all investigated compounds, except DCyt, prevents their pairing in both mutagenic and canonical tautomeric forms with a base which is an interacting partner. This effect can inhibit their mutagenic potential. It is also established that Watson-Crick tautomeric hypothesis can be formally expanded for the investigated molecules so far as a lifetime of the mutagenic tautomers much more exceeds characteristic time for the incorporation of one nucleotides pair by DNA biosynthesis machinery. It seems that just within the frame of this hypothesis it will be possible to give an adequate explanation of the mechanisms of mutagenic action of N4-aminocytosine, N4-methoxycytosine, N4-hydroxycytosine and N4dehydrocytosine, which have much more energy advantageous imino form in comparison with amino form. Conclusions. For the first time the comprehensive conformational analysis of a number of classical mutagens, namely cytosine derivatives, has been performed using the methods of non-empirical quantum chemistry at the MP2/6-311++G (2df,pd//B3LYP/6-311++G(d,p level of theory

  10. Topographical surveys: Classical method versus 3D laser scanning. Case study - An application in civil engineering

    Science.gov (United States)

    Grigoraş, I.-R.; Covăsnianu, A.; Pleşu, G.; Benedict, B.

    2009-04-01

    The paper describes an experiment which took place in Iasi town, Romania, consisted in two different topographical survey techniques applied for one and the same objective placed in a block within the city (western part) - a thermal power station. The purpose was to compare those methods and to determine which one is proper to be used in this domain in terms of fastness, optimization and speed of data processing. First technique applied for our survey was the classical one, with a total station. Using the CAD technique, we obtained a final product (a dwg file) and a list of coordinates (a text file). The second method, which we focused our attention more, was the measurement with a very precise 3D laser scanstation, also very suitable in archeology. The data obtained were processed with special software. Result was a 3D model of the thermal power plant composed of measurable cloud point data. Finally, analyzing the advantages and disadvantages of each method, we came to the conclusion that the 3D laser scanning which we used matches well the application, in this case civil engineering, but the future of accepting and implementing this technique is in the hands of Romanian authorities.

  11. Advanced study of thermal behaviour of CSZ comparing with the classic YSZ coating

    Science.gov (United States)

    Dragomirescu, A.; Constantin, N.; Ştefan, A.; Manoliu, V.; Truşcă, R.

    2017-01-01

    Thermal barrier coatings (TBC) are advanced materials typically applied to metal surfaces subjected to extreme temperatures to protect them and increase their lifetime. Ceria stabilized zirconia ceramic layer (CSZ) is increasingly used as an alternative improved as replace for classical TBC system - yttria stabilized zirconia - thanks to superior properties, including mechanical and high resistance to thermal corrosion. The paper describes the thermal shock testing of two types of thermal barrier coatings used to protect a nickel super alloy. For the experimental procedure, it was used plate samples from nickel super alloy with a bond coat and a ceramic top coat. The top coat was different: on some samples, it was used YSZ and on others CSZ. Ni based super alloys have good corrosion resistance in reducing environments action, but poor in oxidizing conditions. Extreme environments can lead to loss of material by oxidation / corrosion, along with decreased mechanical properties of the substrate due to damaging elements which diffuses into the substrate at high temperatures. Using laboratory equipment, the TBC systems were exposed repeatedly to extreme high temperatures for a short time and then cooled. After the thermal shock tests, the samples were morph-structured characterized using electronic microscopy to analyze the changes. The experimental results were compared to rank the TBC systems in order of performance.

  12. Quantum algorithmic integrability: The metaphor of classical polygonal billiards

    Science.gov (United States)

    Mantica, Giorgio

    2000-06-01

    We study the algorithmic complexity of motions in classical polygonal billiards, which, as the number of sides increases, tend to curved billiards, both regular and chaotic. This study unveils the equivalence of this problem to the procedure of quantization: the average complexity of symbolic trajectories in polygonal billiards features the same scaling relations (with respect to the number of sides) that govern quantum systems when a semiclassical parameter is varied. Two cases, the polygonal approximations of the circle and of the stadium, are examined in detail and are presented as paradigms of quantization of integrable and chaotic systems.

  13. Ensemble simulations with discrete classical dynamics

    DEFF Research Database (Denmark)

    Toxværd, Søren

    2013-01-01

    For discrete classical Molecular dynamics (MD) obtained by the "Verlet" algorithm (VA) with the time increment $h$ there exist a shadow Hamiltonian $\\tilde{H}$ with energy $\\tilde{E}(h)$, for which the discrete particle positions lie on the analytic trajectories for $\\tilde{H}$. $\\tilde...

  14. Mental health trajectories from childhood to young adulthood affect the educational and employment status of young adults: results from the TRAILS study.

    Science.gov (United States)

    Veldman, Karin; Reijneveld, Sijmen A; Ortiz, Josue Almansa; Verhulst, Frank C; Bültmann, Ute

    2015-06-01

    Young adults at work without basic educational level (BEL), and young adults in Neither Employment, Education nor Training (NEET) are at high risk of adverse employment outcomes. Evidence lacks on the impact of mental health problems during childhood, adolescence and young adulthood on employment outcomes of young adults. Therefore, the aims of this study were to (1) identify trajectories of mental health problems from childhood to young adulthood and (2) investigate the relation between these trajectories and the educational or employment status of young adults. Data were used from the Tracking Adolescents' Individual Lives Survey (TRAILS), a Dutch prospective cohort study with 9-year follow-up. Trajectories of mental health problems measured at ages 11, 13.5, 16 and 19 years were identified in 1711 young adults with latent class growth models. Young adults with high-stable trajectories of total problems, from childhood to young adulthood, were more likely to work without BEL or be in NEET at age 19, than to be at school or to work with BEL (28.0% vs 16.0%, p=0.01). The same was found for externalising problems (35.3% vs 23.2%, p=0.02). For internalising and attention problems, no statistically significant differences were found. Young adults with high-stable trajectories of mental health problems from age 11 to 19, were at risk of adverse employment outcomes. Interventions reducing mental health problems in childhood may improve the educational or employment status of young adults and their chances for successfully entering the labour market. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  15. Pestilence narratives in classical literature: a study in creative imitation. II. Virgil, Ovid, Seneca, and Silius Italicus.

    Science.gov (United States)

    Dirckx, J H

    2000-10-01

    This article further explores patterns and traditions in classical accounts of pestilence. Recurring themes and expressions show that classical authors often copied earlier narratives, although literary analysis reveals that they sometimes embellished or distorted facts for their own purposes.

  16. Classical approach in atomic physics

    Science.gov (United States)

    Solov'ev, E. A.

    2011-12-01

    The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of a hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom discovered with the help of Poincaré section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treated as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormgroup symmetry, criterion of accuracy and so on are reviewed as well.

  17. Classical approach in atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Solov' ev, E.A. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation)

    2011-12-15

    The application of a classical approach to various quantum problems - the secular perturbation approach to quantization of a hydrogen atom in external fields and a helium atom, the adiabatic switching method for calculation of a semiclassical spectrum of a hydrogen atom in crossed electric and magnetic fields, a spontaneous decay of excited states of a hydrogen atom, Gutzwiller's approach to Stark problem, long-lived excited states of a helium atom discovered with the help of Poincare section, inelastic transitions in slow and fast electron-atom and ion-atom collisions - is reviewed. Further, a classical representation in quantum theory is discussed. In this representation the quantum states are treated as an ensemble of classical states. This approach opens the way to an accurate description of the initial and final states in classical trajectory Monte Carlo (CTMC) method and a purely classical explanation of tunneling phenomenon. The general aspects of the structure of the semiclassical series such as renormalization group symmetry, criterion of accuracy and so on are reviewed as well. (author)

  18. Toward a new understanding of legacy of early attachments for future antisocial trajectories: evidence from two longitudinal studies.

    Science.gov (United States)

    Kochanska, Grazyna; Kim, Sanghag

    2012-08-01

    Early parent-child attachment has been extensively explored as a contributor to children's future adaptive or antisocial outcomes, but the specific developmental mechanisms remain to be fully understood. We examined long-term indirect developmental sequelae of early security in two longitudinal community samples followed from infancy to early school age: the Family Study (102 mothers, fathers, and infants) and the Parent-Child Study (112 mothers and infants). Constructs at multiple levels (child characteristics, parent-child security, parental discipline, and child antisocial outcomes) were assessed using a range of methods (extensive behavioral observations in a variety of settings, informants' ratings). Both studies supported the proposed model of infant attachment as a potent catalyst that moderates future developmental socialization trajectories, despite having few long-term main effects. In insecure dyads, a pattern of coercion emerged between children who were anger prone as toddlers and their parents, resulting in parents' increased power-assertive discipline. Power assertion in turn predicted children's rule-breaking conduct and a compromised capacity to delay in laboratory paradigms, as well as oppositional, disruptive, callous, and aggressive behavior rated by parents and teachers at early school age. This causal chain was absent in secure dyads, where child anger proneness was unrelated to power assertion, and power assertion was unrelated to antisocial outcomes. Early insecurity appeared to act as a catalyst for the parent-child dyad embarking on a mutually adversarial path toward antisocial outcomes, whereas security defused such a maladaptive dynamic. The possible mechanisms of those effects were proposed.

  19. Studying the Identity of Iranian Classical Effective Literature and Contemporary Impressible Literature

    Directory of Open Access Journals (Sweden)

    Abdolmajid Mohaqeqi

    2014-11-01

    Full Text Available After the advent of Islam in Iran, Persian Literature has always been considered as one of the major characteristics of Iranian culture and identity to the extent that some people believe whatever western has achieved in terms of literature – especially English literature – and honors to them originate from rich Persian literature. However, Persian literature has severely been influenced by works of western writers in contemporary era so that even modern Persian story and poem is divided based on western styles. Unfortunately, this situation – that a part of identity of Iranian culture has been drastically affected by alien culture – offends each educated Iranian. Today, a flashback to Iranian classical styles does not meet the need for a development created in literary works. However, it is necessary that tasteful and patriotic people create novel works in Iran’s contemporary literature against the decades-old literary identity of the west through adaptation of past-targeted literature and under the effect of conditions of today modern society in order to recover the lost identity of Iranian literature which other fields are considered as its subset. Therefore, this paper is going to present solutions for modeling the identity of Iranian literature for the next two decades in line with Islamization of universities in order to divide the pure academic literature into pure and applied sub-branches and develop academic literary activities. As a result, the international works would be established based on the columns of Persian literature whose kernel will not to be damaged in the rain and wind of alien cultures.

  20. Trajectories in parallel optics.

    Science.gov (United States)

    Klapp, Iftach; Sochen, Nir; Mendlovic, David

    2011-10-01

    In our previous work we showed the ability to improve the optical system's matrix condition by optical design, thereby improving its robustness to noise. It was shown that by using singular value decomposition, a target point-spread function (PSF) matrix can be defined for an auxiliary optical system, which works parallel to the original system to achieve such an improvement. In this paper, after briefly introducing the all optics implementation of the auxiliary system, we show a method to decompose the target PSF matrix. This is done through a series of shifted responses of auxiliary optics (named trajectories), where a complicated hardware filter is replaced by postprocessing. This process manipulates the pixel confined PSF response of simple auxiliary optics, which in turn creates an auxiliary system with the required PSF matrix. This method is simulated on two space variant systems and reduces their system condition number from 18,598 to 197 and from 87,640 to 5.75, respectively. We perform a study of the latter result and show significant improvement in image restoration performance, in comparison to a system without auxiliary optics and to other previously suggested hybrid solutions. Image restoration results show that in a range of low signal-to-noise ratio values, the trajectories method gives a significant advantage over alternative approaches. A third space invariant study case is explored only briefly, and we present a significant improvement in the matrix condition number from 1.9160e+013 to 34,526.

  1. Opposite Drug Prescription and Cost Trajectories following Integrative and Conventional Care for Pain – A Case-Control Study

    Science.gov (United States)

    Sundberg, Tobias; Petzold, Max; Kohls, Niko; Falkenberg, Torkel

    2014-01-01

    Objectives Pharmacotherapy may have a limited role in long-term pain management. Comparative trajectories of drug prescriptions and costs, two quality-of-care indicators for pain conditions, are largely unknown subsequent to conventional or integrative care (IC) management. The objectives of this study were to compare prescribed defined daily doses (DDD) and cost of first line drugs for pain patients referred to conventional or anthroposophic IC in Stockholm County, Sweden. Methods In this retrospective high quality registry case-control study, IC and conventional care patients were identified through inpatient care registries and matched on pain diagnosis (ICD-10: M79), age, gender and socio-demographics. National drug registry data was used to investigate changes in DDD and costs from 90/180 days before, to 90/180 days after, index visits to IC and conventional care. The primary selected drug category was analgesics, complemented by musculo-skeletal system drugs (e.g. anti-inflammatories, muscle relaxants) and psycholeptics (e.g. hypnotics, sedatives). Results After index care visits, conventional care pain patients (n = 1050) compared to IC patients (n = 213), were prescribed significantly more analgesics. The average (95% CI) group difference was 15.2 (6.0 to 24.3), p = 0.001, DDD/patient after 90 days; and 21.5 (7.4 to 35.6), p = 0.003, DDD/patient after 180 days. The cost of the prescribed and sold analgesics was significantly higher for conventional care after 90 days: euro/patient 10.7 (1.3 to 20.0), p = 0.025. Changes in drug prescription and costs for the other drug categories were not significantly different between groups. Conclusions Drug prescriptions and costs of analgesics increased following conventional care and decreased following IC, indicating potentially fewer adverse drug events and beneficial societal cost savings with IC. PMID:24827981

  2. Long-Term Trajectories of Health-Related Quality of Life in Individuals With Cerebral Palsy : A Multicenter Longitudinal Study

    NARCIS (Netherlands)

    Tan, Siok Swan; van Meeteren, Jetty; Ketelaar, Marjolijn; Schuengel, Carlo; Reinders - Messelink, Heelen; Raat, Hein; Dallmeijer, Annet J.; Roebroeck, Marij E.

    2014-01-01

    Objectives: To (1) determine the long-term trajectory of health-related quality of life (HRQOL) for the dimensions of physical complaints and motor, psychological, and social functioning for groups of individuals with cerebral palsy (CP) aged 1 to 24 years; (2) assess the variability in HRQOL within

  3. Magnetic trapping of neutral particles Classical and Quantum-mechanical study of a Ioffe-Pritchard type trap

    CERN Document Server

    Gov, S; Thomas, H

    1999-01-01

    Recently, we developed a method for calculating the lifetime of a particle inside a magnetic trap with respect to spin flips, as a first step in our efforts to understand the quantum-mechanics of magnetic traps. The 1D toy model that was used in this study was physically unrealistic because the magnetic field was not curl-free. Here, we study, both classically and quantum-mechanically, the problem of a neutral particle with spin S, mass m and magnetic moment mu, moving in 3D in an inhomogeneous magnetic field corresponding to traps of the Ioffe-Pritchard, `clover-leaf' and `baseball' type. Defining by omega_p, omega_z and omega_r the precessional, the axial and the lateral vibrational frequencies, respectively, of the particle in the adiabatic potential, we find classically the region in the $(ømega_{r}% (omega_r -- omega_z) plane where the particle is trapped. Quantum-mechanically, we study the problem of a spin-one particle in the same field. Treating omega_r / omega_p and omega_z / omega_p as small parame...

  4. Problems in classical mechanics

    CERN Document Server

    Katkar, L N

    2014-01-01

    Problems in classical mechanics presents a lucid treatment of the formulations of Lagrangian, Hamiltonian, and the Principles of Calculus of Variations etc. important for the study of modern physics. The study of classical mechanics prepares students to apply the principles and the mathematical tools to solve real life problems. The book also incorporates and discusses in detail topics such as Central Force Motion, Rigid Body Motion and Canonical Transformations. KEY FEATURES: Around 200 solved examples with complete mathematical theory Around 70 examples given as an exercise to test and develop students understanding The physical interpretation of the Hamiltonian is highlighted

  5. Bone mineral status in Egyptian children with classic congenital adrenal hyperplasia. A single-center study from Upper Egypt

    Directory of Open Access Journals (Sweden)

    Kotb Abbass Metwalley

    2014-01-01

    Full Text Available Aim of the Study: To evaluate bone mineral density (BMD and levels of bone turnover markers in Egyptian children with classic congenital adrenal hyperplasia (CAH caused by 21-hydroxylase deficiency and its relationship with disease-related variables. Patients and Methods: The study population consisted of 28 children from Upper Egypt with classic CAH, their mean age 8.3 ± 2.4 years and 28 age and sex matched healthy control. They were subjected to measurement of BMD of lumbar spines (L1-L4 and femoral neck using dual-energy-X-ray absorptiometry (DXA and laboratory evaluation of bone turnover markers including Osteocalcin and serum receptor activator of nuclear factor αB-ligand (RANKL. Result: Children with CAH had significantly lower bone-mineral density (BMD for both, vertebrae and femoral neck than controls. This difference is more obvious in children with poor control and in those receiving prednisone therapy. There was a significantly lower serum osteocalcin, and significantly higher serum RANKL levels in patients with CAH than the healthy controls. This differences is more obvious in children with poor control and in those receiving prednisone therapy. Total bone mineral content (BMC [gm] have significant negative correlations to age (r = −0.81, P < 0.001, disease duration (r = −0.881, P < 0.001, 17 OH Progesterone level (r = −0.543, P < 0.05, RANKL level (r = −0.635, P < 0.05, and significant positive correlation with osteocalcin (r = 0.576, P < 0.001. Conclusions: Children from Upper Egypt with classic CAH may have reduced BMD and increase bone turnover compared with controls. This difference is more obvious in children with poor control and in those receiving prednisone therapy. Recommendations: Active monitoring of BMD in CAH children using Dual-energy X-ray absorptiometry (DEXA scanning. Furthermore, effort should be done to bring hydrocortisone to Upper Egypt to replace prednisone in children with classic congenital adrenal

  6. Lunar and interplanetary trajectories

    CERN Document Server

    Biesbroek, Robin

    2016-01-01

    This book provides readers with a clear description of the types of lunar and interplanetary trajectories, and how they influence satellite-system design. The description follows an engineering rather than a mathematical approach and includes many examples of lunar trajectories, based on real missions. It helps readers gain an understanding of the driving subsystems of interplanetary and lunar satellites. The tables and graphs showing features of trajectories make the book easy to understand. .

  7. Trajectory P system

    Institute of Scientific and Technical Information of China (English)

    Subbaiah Annadurai; Thiyagarajan Kalyani; Vincent Rajkumar Dare; Durairaj Gnanaraj Thomas

    2008-01-01

    Membrane computing is a branch of natural computing aiming to abstract computing ideas for the structure and the functioning of living cells as well as from the way the cells are organized in tissues or higher-order structures.Trajectories are used as a tool for modeling language operations and other related objects.A trajectory P system consists of a membrane structure in which the object in each membrane is a collection of words and the evolutionary rules are given in terms of trajectories.In this paper,we present some properties of trajectory P systems.

  8. Surveillance strategies for Classical Swine Fever in wild boar – a comprehensive evaluation study to ensure powerful surveillance

    Science.gov (United States)

    Schulz, Katja; Peyre, Marisa; Staubach, Christoph; Schauer, Birgit; Schulz, Jana; Calba, Clémentine; Häsler, Barbara; Conraths, Franz J.

    2017-01-01

    Surveillance of Classical Swine Fever (CSF) should not only focus on livestock, but must also include wild boar. To prevent disease transmission into commercial pig herds, it is therefore vital to have knowledge about the disease status in wild boar. In the present study, we performed a comprehensive evaluation of alternative surveillance strategies for Classical Swine Fever (CSF) in wild boar and compared them with the currently implemented conventional approach. The evaluation protocol was designed using the EVA tool, a decision support tool to help in the development of an economic and epidemiological evaluation protocol for surveillance. To evaluate the effectiveness of the surveillance strategies, we investigated their sensitivity and timeliness. Acceptability was analysed and finally, the cost-effectiveness of the surveillance strategies was determined. We developed 69 surveillance strategies for comparative evaluation between the existing approach and the novel proposed strategies. Sampling only within sub-adults resulted in a better acceptability and timeliness than the currently implemented strategy. Strategies that were completely based on passive surveillance performance did not achieve the desired detection probability of 95%. In conclusion, the results of the study suggest that risk-based approaches can be an option to design more effective CSF surveillance strategies in wild boar. PMID:28266576

  9. Surveillance strategies for Classical Swine Fever in wild boar - a comprehensive evaluation study to ensure powerful surveillance.

    Science.gov (United States)

    Schulz, Katja; Peyre, Marisa; Staubach, Christoph; Schauer, Birgit; Schulz, Jana; Calba, Clémentine; Häsler, Barbara; Conraths, Franz J

    2017-03-07

    Surveillance of Classical Swine Fever (CSF) should not only focus on livestock, but must also include wild boar. To prevent disease transmission into commercial pig herds, it is therefore vital to have knowledge about the disease status in wild boar. In the present study, we performed a comprehensive evaluation of alternative surveillance strategies for Classical Swine Fever (CSF) in wild boar and compared them with the currently implemented conventional approach. The evaluation protocol was designed using the EVA tool, a decision support tool to help in the development of an economic and epidemiological evaluation protocol for surveillance. To evaluate the effectiveness of the surveillance strategies, we investigated their sensitivity and timeliness. Acceptability was analysed and finally, the cost-effectiveness of the surveillance strategies was determined. We developed 69 surveillance strategies for comparative evaluation between the existing approach and the novel proposed strategies. Sampling only within sub-adults resulted in a better acceptability and timeliness than the currently implemented strategy. Strategies that were completely based on passive surveillance performance did not achieve the desired detection probability of 95%. In conclusion, the results of the study suggest that risk-based approaches can be an option to design more effective CSF surveillance strategies in wild boar.

  10. Teaching Classical Mechanics using Smartphones

    CERN Document Server

    Chevrier, Joel; Ledenmat, Simon; Bsiesy, Ahmad

    2012-01-01

    Using a personal computer and a smartphone, iMecaProf is a software that provides a complete teaching environment for practicals associated to a Classical Mechanics course. iMecaProf proposes a visual, real time and interactive representation of data transmitted by a smartphone using the formalism of Classical Mechanics. Using smartphones is more than using a set of sensors. iMecaProf shows students that important concepts of physics they here learn, are necessary to control daily life smartphone operations. This is practical introduction to mechanical microsensors that are nowadays a key technology in advanced trajectory control. First version of iMecaProf can be freely downloaded. It will be tested this academic year in Universit\\'e Joseph Fourier (Grenoble, France)

  11. Trajectories of glycaemia, insulin sensitivity, and insulin secretion before diagnosis of type 2 diabetes: an analysis from the Whitehall II study

    DEFF Research Database (Denmark)

    Tabák, A.G.; Jokela, M.; Akbaraly, T.N.

    2009-01-01

    BACKGROUND: Little is known about the timing of changes in glucose metabolism before occurrence of type 2 diabetes. We aimed to characterise trajectories of fasting and postload glucose, insulin sensitivity, and insulin secretion in individuals who develop type 2 diabetes. METHODS: We analysed data...... from our prospective occupational cohort study (Whitehall II study) of 6538 (71% male and 91% white) British civil servants without diabetes mellitus at baseline. During a median follow-up period of 9.7 years, 505 diabetes cases were diagnosed (49.1% on the basis of oral glucose tolerance test). We...... assessed retrospective trajectories of fasting and 2-h postload glucose, homoeostasis model assessment (HOMA) insulin sensitivity, and HOMA beta-cell function from up to 13 years before diabetes diagnosis (diabetic group) or at the end of follow-up (non-diabetics). FINDINGS: Multilevel models adjusted...

  12. Dynamical Convergence Trajectory in Networks

    Institute of Scientific and Technical Information of China (English)

    TAN Ning; ZHANG Yun-Jun; OUYANG Qi; GENG Zhi

    2005-01-01

    @@ It is well known that topology and dynamics are two major aspects to determine the function of a network. We study one of the dynamic properties of a network: trajectory convergence, i.e. how a system converges to its steady state. Using numerical and analytical methods, we show that in a logical-like dynamical model, the occurrence of convergent trajectory in a network depends mainly on the type of the fixed point and the ratio between activation and inhibition links. We analytically proof that this property is induced by the competition between two types of state transition structures in phase space: tree-like transition structure and star-like transition structure. We show that the biological networks, such as the cell cycle network in budding yeast, prefers the tree-like transition structures and suggest that this type of convergence trajectories may be universal.

  13. Elementary classical hydrodynamics

    CERN Document Server

    Chirgwin, B H; Langford, W J; Maxwell, E A; Plumpton, C

    1967-01-01

    Elementary Classical Hydrodynamics deals with the fundamental principles of elementary classical hydrodynamics, with emphasis on the mechanics of inviscid fluids. Topics covered by this book include direct use of the equations of hydrodynamics, potential flows, two-dimensional fluid motion, waves in liquids, and compressible flows. Some general theorems such as Bernoulli's equation are also considered. This book is comprised of six chapters and begins by introducing the reader to the fundamental principles of fluid hydrodynamics, with emphasis on ways of studying the motion of a fluid. Basic c

  14. Trajectory similarity join in spatial networks

    KAUST Repository

    Shang, Shuo

    2017-09-07

    The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider the case of trajectory similarity join (TS-Join), where the objects are trajectories of vehicles moving in road networks. Thus, given two sets of trajectories and a threshold θ, the TS-Join returns all pairs of trajectories from the two sets with similarity above θ. This join targets applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide a purposeful definition of similarity. To enable efficient TS-Join processing on large sets of trajectories, we develop search space pruning techniques and take into account the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer algorithm. For each trajectory, the algorithm first finds similar trajectories. Then it merges the results to achieve a final result. The algorithm exploits an upper bound on the spatiotemporal similarity and a heuristic scheduling strategy for search space pruning. The algorithm\\'s per-trajectory searches are independent of each other and can be performed in parallel, and the merging has constant cost. An empirical study with real data offers insight in the performance of the algorithm and demonstrates that is capable of outperforming a well-designed baseline algorithm by an order of magnitude.

  15. Connection Between Quantum-Classical Correspondence and Long-Range Correlations in Quantum Spectra

    Institute of Scientific and Technical Information of China (English)

    LI Xi-Guo; SONG Jian-Jun

    2004-01-01

    @@ Based on the Berry-Tabor trace formula, a semiclassical quantization condition for the periodic orbits in a two dimensional uncoupled oscillator system and the correspondence relation between the quantum levels and classical trajectories of the system have been studied in detail. Making use of the quantum-classical correspondence relation, it has been found that if a set of quantum levels corresponds to the periodic orbits with the same topology structure M ( M1, M2 ), there will be long-range correlations among these quantum levels.

  16. The Envelope of Projectile Trajectories in Midair

    CERN Document Server

    Chudinov, P

    2005-01-01

    A classic problem of the motion of a point mass (projectile) thrown at an angle to the horizon is reviewed. The air drag force is taken into account with the drag factor assumed to be constant. Analytic approach is used for investigation. Simple analytical formulas are used for the constructing the envelope of the family of the point mass trajectories. The equation of envelope is applied for determination of maximum range of flight. The motion of a baseball is presented as an example.

  17. 平面磁力研磨轨迹的研究与分析%Study and analysis on plane magnetic abrasive trajectory

    Institute of Scientific and Technical Information of China (English)

    焦安源; 邹艳华

    2011-01-01

    In this paper, complex polishing trajectory of magnetic brush has been modified and studied by use of newly designed experiment device. The results show the surface roughness and precision can be elevated, and the homogeneity of section shape can also be improved in improving process. In addition, the magnetic abrasive finishing results can be predicted by the theoretical analysis on polishing trajectory of magnetic brush.%利用自行设计的试验装置,改善了磁力刷的研磨轨迹.结果表明:改善磁力刷研磨轨迹后,不仅可以减小表面粗糙度值、提高平面精度,还改善了研磨截面微观形状均匀性.另外,可通过采取理论分析的方法对研磨效果进行预测.

  18. Access, Coping and Relevance of Education at Local Level: A Case Study. A life course approach to the analysis of young people’s educational trajectories

    Directory of Open Access Journals (Sweden)

    Silvia Demozzi

    2016-07-01

    Full Text Available The present paper introduces the objectives and the design of the project “Governance of Educational Trajectories in Europe” (GOETE and it presents some findings emerging from a case study conducted in one of the cities involved in the project, Bologna. GOETE project analyzed how educational trajectories of children and young people between the end of primary education and the beginning of post-compulsory routes are regulated in eight different EU-member states: Finland, France, Germany, Italy, Netherlands, Poland, Slovenia and the UK. The research assesses the outcomes of education, taking into account the effects of social inequalities, changes in the governance of education in terms of lifelong learning, knowledge societies and transnational educational spaces. “Life course” perspective provides an interactive understanding of educational processes and addresses the interplay between the institutionalization of individual lives and subjective biographies.

  19. Quasiclassical trajectory study on the integral cross-section and stereodynamics information of the reaction O(1D) + H2(v = 0, j = 0) → OH + H

    Indian Academy of Sciences (India)

    Tianyun Chen; Ningjiu Zhao; Weiping Zhang; Dongjun Wang; Xinqiang Wang

    2011-05-01

    Integral cross-section and stereodynamics study of the reaction O(1D)+H2( = 0, = 0) → OH + H is undertaken using the quasiclassical trajectory (QCT) method for the collision energy is in the large length of 1.3 to 43 kcal/mol using Dobbyn and Knowles (DK) surface, and the obtained results are compared with those available from earlier available calculated results on the BR surface. The integral cross sections obtained from the quasiclassical trajectory method are in good agreement with those of Chebyshev wave packet method for collision energies above 0.2 eV.We also investigated the vector correlations and polarized dependent differential cross sections (PDDCS) at different collision energies. It is demonstrated that the alignment and state distribution significantly decrease with increase in the collision energy.

  20. Physical activity and trajectories of frailty among older adults: Evidence from the English Longitudinal Study of Ageing

    Science.gov (United States)

    Marshall, Alan; Roberts, Chrissy H.; Demakakos, Panayotes; Steptoe, Andrew; Scholes, Shaun

    2017-01-01

    Background Frail older adults are heavy users of health and social care. In order to reduce the costs associated with frailty in older age groups, safe and cost-effective strategies are required that will reduce the incidence and severity of frailty. Objective We investigated whether self-reported intensity of physical activity (sedentary, mild, moderate or vigorous) performed at least once a week can significantly reduce trajectories of frailty in older adults who are classified as non-frail at baseline (Rockwood’s Frailty Index [FI] ≤ 0.25). Methods Multi-level growth curve modelling was used to assess trajectories of frailty in 8649 non-frail adults aged 50 and over and according to baseline self-reported intensity of physical activity. Frailty was measured in five-year age cohorts based on age at baseline (50–54; 55–59; 60–64; 65–69; 70–74; 75–79; 80+) on up to 6 occasions, providing an average of 10 years of follow-up. All models were adjusted for baseline sex, education, wealth, cohabitation, smoking, and alcohol consumption. Results Compared with the sedentary reference group, mild physical activity was insufficient to significantly slow the progression of frailty, moderate physical activity reduced the progression of frailty in some age groups (particularly ages 65 and above) and vigorous activity significantly reduced the trajectory of frailty progression in all older adults. Conclusion Healthy non-frail older adults require higher intensities of physical activity for continued improvement in frailty trajectories. PMID:28152084

  1. Ten-Year Blood Pressure Trajectories, Cardiovascular Mortality, and Life Years Lost in 2 Extinction Cohorts: the Minnesota Business and Professional Men Study and the Zutphen Study

    NARCIS (Netherlands)

    Tielemans, S.M.A.J.; Geleijnse, J.M.; Menotti, A.; Boshuizen, H.C.; Soedamah-Muthu, S.S.; Jacobs, D.R.; Blackburn, H.; Kromhout, D.

    2015-01-01

    Background Blood pressure (BP) trajectories derived from measurements repeated over years have low measurement error and may improve cardiovascular disease prediction compared to single, average, and usual BP (single BP adjusted for regression dilution). We characterized 10-year BP trajectories and

  2. Early Life Factors and Inter-Country Heterogeneity in BMI Growth Trajectories of European Children: The IDEFICS Study.

    Directory of Open Access Journals (Sweden)

    Claudia Börnhorst

    Full Text Available Starting from birth, this explorative study aimed to investigate between-country differences in body mass index (BMI trajectories and whether early life factors explain these differences.The sample included 7,644 children from seven European countries (Belgium, Cyprus, Germany, Hungary, Italy, Spain, Sweden participating in the multi-centre IDEFICS study. Information on early life factors and in total 53,409 repeated measurements of height and weight from 0 to <12 years of age were collected during the baseline (2007/2008 and follow-up examination (2009/2010 supplemented by records of routine child health visits. Country-specific BMI growth curves were estimated using fractional polynomial mixed effects models. Several covariates focussing on early life factors were added to the models to investigate their role in the between-countries differences.Large between-country differences were observed with Italian children showing significantly higher mean BMI values at all ages ≥ 3 years compared to the other countries. For instance, at age 11 years mean BMI values in Italian boys and girls were 22.3 [21.9;22.8; 99% confidence interval] and 22.0 [21.5;22.4], respectively, compared to a range of 18.4 [18.1;18.8] to 20.3 [19.8;20.7] in boys and 18.2 [17.8;18.6] to 20.3 [19.8;20.7] in girls in the other countries. After adjustment for early life factors, differences between country-specific BMI curves became smaller. Maternal BMI was the factor being most strongly associated with BMI growth (p<0.01 in all countries with associations increasing during childhood. Gestational weight gain (GWG was weakly associated with BMI at birth in all countries. In some countries, positive associations between BMI growth and children not being breastfed, mothers' smoking during pregnancy and low educational level of parents were found.Early life factors seem to explain only some of the inter-country variation in growth. Maternal BMI showed the strongest association

  3. Comparison of quantum and classical relaxation in spin dynamics.

    Science.gov (United States)

    Wieser, R

    2013-04-01

    The classical Landau-Lifshitz equation with a damping term has been derived from the time evolution of a quantum mechanical wave function under the assumption of a non-Hermitian Hamilton operator. Further, the trajectory of a classical spin (S) has been compared with the expectation value of the spin operator (Ŝ). A good agreement between classical and quantum mechanical trajectories can be found for Hamiltonians linear in Ŝ or S, respectively. Quadratic or higher order terms in the Hamiltonian result in a disagreement.

  4. 14 CFR 417.207 - Trajectory analysis.

    Science.gov (United States)

    2010-01-01

    ... potential three-sigma trajectory dispersions about the nominal trajectory. (2) A fuel exhaustion trajectory...) Trajectory model. A final trajectory analysis must use a six-degree of freedom trajectory model to...

  5. PANTHER. Trajectory Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rintoul, Mark Daniel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Wilson, Andrew T. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Valicka, Christopher G. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Kegelmeyer, W. Philip [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Shead, Timothy M. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Newton, Benjamin D. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Czuchlewski, Kristina Rodriguez [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    We want to organize a body of trajectories in order to identify, search for, classify and predict behavior among objects such as aircraft and ships. Existing compari- son functions such as the Fr'echet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as total distance traveled and distance be- tween start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally, these features can generally be mapped easily to behaviors of interest to humans that are searching large databases. Most of these geometric features are invariant under rigid transformation. We demonstrate the use of different subsets of these features to iden- tify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories, predict destination and apply unsupervised machine learning algorithms.

  6. Learn with the Classics: Using Music To Study Smart at Any Age.

    Science.gov (United States)

    Andersen, Ole; Marsh, Marcy; Harvey, Arthur

    This book, accompanied by a musical CD-ROM, provides information on how to enhance learning through music at any age. Sections include: (1) "Let Music Prime Your Brain For Learning," which teaches how important it is to prime the brain for learning through music; (2) "Study Smart," which demonstrates highly effective studying techniques devised by…

  7. A nonextinction procedure for long-term studies of classically conditioned enhancement of acoustic startle in the rat.

    Science.gov (United States)

    Winston, C R; Leavell, B J; Ardayfio, P A; Beard, C; Commissaris, R L

    2001-05-01

    In the Fear-Potentiated Startle (FPS) paradigm, the reflexive response to a noise burst is enhanced when it is presented with a stimulus (typically a light) that previously had been paired with the presentation of an aversive stimulus, usually an electric shock. In the FPS paradigm, the conditioned effect is demonstrated under conditions of extinction, i.e., the light is not paired with the shock during FPS testing. Because of this, the FPS paradigm is of somewhat limited value as a longitudinal measure for studying classically conditioned enhancement of acoustic startle. The present studies report a simple and reliable nonshock procedure for studying classically conditioned potentiation of acoustic startle in the rat that does not utilize testing under conditions of extinction. Naive rats were exposed to 5-or 3-days/week startle test sessions for up to 20 weeks. Twenty (20) startle stimuli (115 dB noise bursts; 40 ms in duration) were presented during each session. Half of these startle stimuli were presented in darkness and half were immediately preceded by a 3500-ms presentation of a 15-W light. With this paradigm, the effects of pairing the light with the startle noise burst could be studied across many test sessions in the absence of extinction training. The light did not increase startle amplitude on the first few startle trials of the first test session. By the end of the first session, however, and continuing for many weeks of testing, startle responses in the presence of the light were significantly greater (by 30-40%) than in the absence of the light. The finding that the startle stimulus itself can serve as an unconditioned stimulus (UCS) to enhance subsequent startle responses replicates an earlier finding. The persistence of this Startle-Potentiated Startle (SPS) effect across multiple weeks of testing is in contrast to that earlier report.

  8. Towards Efficient Search for Activity Trajectories

    DEFF Research Database (Denmark)

    Zheng, Kai; Shang, Shuo; Yuan, Jing

    2013-01-01

    The advances in location positioning and wireless communication technologies have led to a myriad of spatial trajectories representing the mobility of a variety of moving objects. While processing trajectory data with the focus of spatio-temporal features has been widely studied in the last decad...

  9. Trajectories of CBCL Attention Problems in childhood

    NARCIS (Netherlands)

    Robbers, S.C.C.; Oort, F.V.A. van; Polderman, T.J.C.; Bartels, M.; Boomsma, D.I.; Verhulst, F.C.; Huizink, A.C.

    2011-01-01

    The first aim of this study was to identify developmental trajectories of Attention Problems in twins followed from age 6 to 12 years. Second, we investigated whether singletons follow similar trajectories. Maternal longitudinal ratings on the Attention Problems (AP) subscale of the Child Behavior

  10. Trajectories of Delinquency and Parenting Styles

    Science.gov (United States)

    Hoeve, Machteld; Blokland, Arjan; Dubas, Judith Semon; Loeber, Rolf; Gerris, Jan R. M.; van der Laan, Peter H.

    2008-01-01

    We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering ages 10-19, we identified five distinct…

  11. Trajectories of CBCL Attention Problems in childhood

    NARCIS (Netherlands)

    S.C.C. Robbers (Sylvana); F.V.A. van Oort (Floor); T.J.C. Polderman (Tinca); M. Bartels (Meike); D.I. Boomsma (Dorret); F.C. Verhulst (Frank); G.H. Lubke (Gitta); A.C. Huizink (Anja)

    2011-01-01

    textabstractThe first aim of this study was to identify developmental trajectories of Attention Problems in twins followed from age 6 to 12 years. Second, we investigated whether singletons follow similar trajectories. Maternal longitudinal ratings on the Attention Problems (AP) subscale of the Chil

  12. The Classical Conditioning of Attitudes: A Comparative Study of Ages 8 to 18

    Science.gov (United States)

    O'Donnell, John M.; Brown, Mari J. K.

    1973-01-01

    Results of this study indicated that attitude conditioning increased with age and that the increase appeared to be a function of contingency awareness and perhaps also a function of the older subjects' having greater facility in transferring symbolic meaning. (Author)

  13. The impact of emotional disturbances on the arrest trajectories of youth as they transition into young adulthood.

    Science.gov (United States)

    Constantine, Robert J; Andel, Ross; Robst, John; Givens, Eugenia M

    2013-08-01

    This article identifies the arrest trajectories of youth from ages 12 through 24 years old and tests hypotheses derived from Moffitt's developmental taxonomic theory of crime concerning the impact of various emotional disturbances on the specific trajectories of the youth involved. The study uses exclusively administrative data sets and includes a gender and racially diverse sample of 10,360 youth (30.7% females) who were arrested at least once between ages 12 and 24 in the early 2000s. Latent class growth analysis was employed in order to identify distinct arrest trajectories of youth in the sample. Multinomial logistic regression was used to identify diagnostic and other characteristics associated with membership in the specific trajectories predicted by Moffitt's theory. Five trajectory classes were identified, 3 of which were consistent with taxonomic theory including high and classic adolescence limited trajectory classes and a "snared adolescence limited class" described more recently by Moffitt. The distribution of youth among the 5 classes was very different for those with and without emotional disturbances. Youth with emotional disturbances in their late adolescent years were more likely to fall into the high arrest trajectory class and much less likely to fall into the low arrest trajectory class. Compared to youth without an emotional disturbance, youth with psychotic disorders were more than twice as likely to fall into the high as into the low arrest trajectory class. Youth with disruptive behavior disorders were more than twice as likely to fall into the high and intermediate classes as into the low trajectory class. Anxiety and depressive disorders were not associated with significantly greater likelihood of falling into any one of the trajectory classes. Youth in the snared adolescence limited class were more likely than those in the classic adolescence limited class to be male, black versus white and in the foster care enrollment category lending

  14. Influence of size and taper of artificial canals on the trajectory of NiTi rotary instruments in cyclic fatigue studies.

    Science.gov (United States)

    Plotino, Gianluca; Grande, Nicola M; Mazza, Ciro; Petrovic, Renata; Testarelli, Luca; Gambarini, Gianluca

    2010-01-01

    The aim of this study was to investigate the influence of the shape of 3 different artificial canals on the trajectory followed by different nickel-titanium rotary instruments. Ten ProFile and Mtwo instruments, tip sizes 20 and 25, taper .06, were tested in 3 simulated root canals with an angle of curvature of 60 degrees and radius of curvature of 5 mm but with different shapes. Geometric analysis of the trajectory that each instrument followed inside the 3 different artificial canals was performed on digital images, determining 3 parameters: angle and radius of the curvature and the position of the center of the curvature. Mean values were then calculated for each instrument size in all of the artificial canals. Data were analysed using 1-way analysis of variance, Holm t test, and Student t test to determine any statistical difference (P difference was noted among the artificial canals for the radius and angle of curvature. No statistically significant difference was noted between instruments of the same size for the radius and angle of curvature and the position of the center of the curve when measured in the canal constructed on the dimension of the instruments. Different instruments follow different trajectories in artificial canals constructed with the same parameters of curvature but different shapes, depending on their different bending properties. All of the instruments respected the established parameters of curvature only when the artificial canal is designed on the dimension of the instruments. Copyright 2010 Mosby, Inc. All rights reserved.

  15. Nahuatl as a Classical, Foreign, and Additional Language: A Phenomenological Study

    Science.gov (United States)

    De Felice, Dustin

    2012-01-01

    In this study, participants learning an endangered language variety shared their experiences, thoughts, and feelings about the often complex and diverse language-learning process. I used phenomenological interviews in order to learn more about these English or Spanish language speakers' journey with the Nahuatl language. From first encounter to…

  16. A Challenge to Classical Facial Proportionality Studies: Conventional Profile and 3d Photography Versus Silhouettes

    Science.gov (United States)

    2012-04-01

    facial asymmetry in stereophotogrammetry, video and laser scanning. In relating this to the face and the study of orthodontics, Drs. Gross, Trotman and...attractiveness. They used digital profile and cephalometric x-rays of three men and three women and altered them with aid of Dolphin Imaging

  17. Numerical study of the classical 2D discrete frustrated phi(4) model

    NARCIS (Netherlands)

    Savkin, V.; Rubtsov, A.N.; Janssen, T.

    2004-01-01

    The two-dimensional discrete frustrated phi(4) model is studied by Monte Carlo simulations for two sets of the parameters of the model. Two phase transitions and a floating-incommensurate phase are observed for the case of stronger frustration. The phase transition from the floating-fluid phase to t

  18. Social Conformity and Autism Spectrum Disorder: A Child-Friendly Take on a Classic Study

    Science.gov (United States)

    Yafai, Abdul-Fattah; Verrier, Diarmuid; Reidy, Lisa

    2014-01-01

    Perhaps surprisingly, given the importance of conformity as a theoretical construct in social psychology and the profound implications autism has for social function, little research has been done on whether autism is associated with the propensity to conform to a social majority. This study is a modern, child-friendly implementation of the…

  19. Social Conformity and Autism Spectrum Disorder: A Child-Friendly Take on a Classic Study

    Science.gov (United States)

    Yafai, Abdul-Fattah; Verrier, Diarmuid; Reidy, Lisa

    2014-01-01

    Perhaps surprisingly, given the importance of conformity as a theoretical construct in social psychology and the profound implications autism has for social function, little research has been done on whether autism is associated with the propensity to conform to a social majority. This study is a modern, child-friendly implementation of the…

  20. Study on Gender-Related Speech Communication in Classical Chinese Poetry

    Science.gov (United States)

    Tian, Xinhe; Qin, Dandan

    2016-01-01

    Gender, formed in men and women's growth which is constrained by social context, is tightly tied to the distinction which is presented in the process of men and women's language use. Hence, it's a new breakthrough for studies on gender and difference by analyzing gender-related speech communication on the background of ancient Chinese culture.

  1. Numerical study of the classical 2D discrete frustrated phi(4) model

    NARCIS (Netherlands)

    Savkin, V.; Rubtsov, A.N.; Janssen, T.

    2004-01-01

    The two-dimensional discrete frustrated phi(4) model is studied by Monte Carlo simulations for two sets of the parameters of the model. Two phase transitions and a floating-incommensurate phase are observed for the case of stronger frustration. The phase transition from the floating-fluid phase to

  2. A Gendered Study of the Working Patterns of Classical Musicians: Implications for Practice

    Science.gov (United States)

    Bennett, Dawn

    2008-01-01

    Despite an increase in participation at all levels of the music profession, women continue to experience fewer opportunities to forge careers in music and are less likely than men to apply for leadership positions. This article presents results from a study in which 152 instrumental musicians reflected upon their professional practice and career…

  3. Phase diagram of the Shastry-Sutherland Kondo lattice model with classical localized spins: a variational calculation study

    Science.gov (United States)

    Shahzad, Munir; Sengupta, Pinaki

    2017-08-01

    We study the Shastry-Sutherland Kondo lattice model with additional Dzyaloshinskii-Moriya (DM) interactions, exploring the possible magnetic phases in its multi-dimensional parameter space. Treating the local moments as classical spins and using a variational ansatz, we identify the parameter ranges over which various common magnetic orderings are potentially stabilized. Our results reveal that the competing interactions result in a heightened susceptibility towards a wide range of spin configurations including longitudinal ferromagnetic and antiferromagnetic order, coplanar flux configurations and most interestingly, multiple non-coplanar configurations including a novel canted-flux state as the different Hamiltonian parameters like electron density, interaction strengths and degree of frustration are varied. The non-coplanar and non-collinear magnetic ordering of localized spins behave like emergent electromagnetic fields and drive unusual transport and electronic phenomena.

  4. Misconceptions on classical mechanics by freshman university students: A case study in a Physics Department in Greece

    Directory of Open Access Journals (Sweden)

    George Stylos

    2008-01-01

    Full Text Available This paper presents results of an empirical research study on Newton’s laws classical mechanics and its perceptions on freshman students at the Physics Department, University of Ioannina, Greece. Results and outcome measures reveal misconceptions on students’ perceptions in consideration of the fundamental concepts in freshman Physics education. The findings showed that the students continue to have the same misconceptions on concepts, such as the students of the high school. The research indicates that the students’ misconceptions remain largely throughout secondary education, which is a proof that there is no effort, where appropriate for conceptual change, according to the constructive model of learning and teaching physics. The objective intended to be reached in this communication is to provide an exchange forum of ideas that would help instructors originate the cause, and subsequently avoid misconceptions in freshman Physics education.

  5. Self-consistent Gaussian approximation study of classical J1-J2 Heisenberg model in honeycomb and diamond lattices

    Directory of Open Access Journals (Sweden)

    N Rahimipour

    2015-07-01

    Full Text Available The classical J1-J2 Heisenberg model on bipartite lattice exhibits "Neel" order. However if the AF interactions between the next nearest neighbor(nnn are increased with respect to the nearest neighbor(nn, the frustration effect arises. In such situations, new phases such as ordered phases with coplanar or spiral ordering and disordered phases such as spin liquids can arise. In this paper we use the self-consistent Gaussian approximation to study the J1-J2 Heisenberg model in honeycomb and diamond lattices. We find the spin liquid phases such as ring-liquid and pancake-liquid in honeycomb lattice.Also for diamond lattice we show that the degeneracy of ground state can be lifted by thermal fluctuations through the order by disorder mechanism.

  6. Electrochemical study in both classical cell and microreactors of flavin adenine dinucleotide as a redox mediator for NADH regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Tzedakis, Theodore, E-mail: tzedakis@chimie.ups-tlse.f [Laboratoire de Genie Chimique, UMR 5503, Universite Paul Sabatier, 31062 Toulouse cedex 04 (France); Cheikhou, Kane [Ecole Superieure Polytechnique de Dakar BP: 16263 Dakar-Fann (Senegal); Jerome, Roche; Karine, Groenen Serrano; Olivier, Reynes [Laboratoire de Genie Chimique, UMR 5503, Universite Paul Sabatier, 31062 Toulouse cedex 04 (France)

    2010-02-28

    The electrochemical reduction of flavin adenine dinucleotide (FAD) is studied in a classical electrochemical cell as well as in two types of microreactors: the first one is a one-channel reactor and the other one, a multichannel filter-press reactor. The ultimate goal is to use the reduced form of flavin (FADH{sub 2}), in the presence of formate dehydrogenase (FDH), in order to continuously regenerate the reduced form of nicotinamide adenine dinucleotide (NADH) for chiral syntheses. Various voltammetric and adsorption measurements were carried out for a better understanding of the redox behavior of the FAD as well as its adsorption on gold. Diffusivity and kinetic electrochemical parameters of FAD were determined.

  7. Quantitative sensory testing in classical trigeminal neuralgia-a blinded study in patients with and without concomitant persistent pain

    DEFF Research Database (Denmark)

    Younis, Samaira; Maarbjerg, Stine; Reimer, Maren

    2016-01-01

    The diagnostic criteria of the third International Classification of Headache Disorders state that there should be no neurological deficits in patients with classical trigeminal neuralgia (TN) at clinical examination. However, studies demonstrating sensory abnormalities at bedside examination in TN...... scores were calculated to process frequency analyses and Z-profiles. We found increased mechanical detection threshold on the symptomatic side (47.2% vs 0%, P = 0.008), asymptomatic side (33.3% vs 0%, P = 0.011), and hand (36% vs 0%, P ... increased mechanical detection threshold on the symptomatic side compared with the asymptomatic side (-2.980 vs -2.166, P = 0.040). Thermal and mechanical hyperalgesia was detected bilaterally in the face and the hand. Trigeminal neuralgia patients with concomitant persistent pain tended to have higher mean...

  8. Classical and quantum proton vibration in a nonharmonic strongly coupled system

    Science.gov (United States)

    McDonald, K. M.; Thorson, W. R.; Choi, J. H.

    1993-09-01

    Classical and quantum descriptions of proton vibration are compared for a coupled nonharmonic model based on an ab initio potential for the bifluoride ion, [FHF]-. Accurate quantum calculations and exact classical dynamics are compared with quantum and classical versions of the self-consistent-field (SCF) approximation. Semiclassical and quantum SCF eigenvalues agree within JWKB-type errors. The SCF scheme closely approximates exact quantum states for the lowest 4-5 vibrational levels of each symmetry, except at avoided crossings where strong CI mixing of SCF levels occurs. True classical motion, however, is mainly irregular except at very low energies, and even where it remains regular it may be strongly reorganized by a 1:1 periodic resonance associated with major potential surface features. Strongly mixed CI states at systematic avoided crossings of SCF levels at higher energies do have classical analogs in the reorganized classical motions seen at low energies; stabilized CI components correspond to a stable periodic 1:1 orbit, destabilized components to an unstable periodic 1:1 elliptical orbit. Canonical perturbation theory is used to study further the sense in which the exactly separable classical SCF Hamiltonian is ``close'' to the true Hamiltonian. Where true motion is modal or SCF-like, first-order perturbed trajectories and second-order perturbed energies describe it very accurately. However since the dynamics can be strongly disturbed even at very low energies, correlation effects are obviously not ``small'' in the sense usually meant in classical dynamics, i.e., that regular trajectories mostly remain regular in the nonseparable perturbed system.

  9. Critical Exponents of the Classical 3D Heisenberg Model A Single-Cluster Monte Carlo Study

    CERN Document Server

    Holm, C; Holm, Christian; Janke, Wolfhard

    1993-01-01

    We have simulated the three-dimensional Heisenberg model on simple cubic lattices, using the single-cluster Monte Carlo update algorithm. The expected pronounced reduction of critical slowing down at the phase transition is verified. This allows simulations on significantly larger lattices than in previous studies and consequently a better control over systematic errors. In one set of simulations we employ the usual finite-size scaling methods to compute the critical exponents $\

  10. Crises Solutions for SMEs Case Study: ERP Cloud vs Classic Solution

    Directory of Open Access Journals (Sweden)

    Gabriela GHEORGHE

    2012-11-01

    Full Text Available Information Technology has responded to the crisis by change and innovation. The phenomenon of cloud computing represents a huge chance for a country like Romania, as a technologically low economy has, from the start, a handicap. Cloud technologies redefine concepts such as saving time and money, flexibility, scalability and global access, transforming them into business advantages. This case study wishes to argument the software provider’s decision to change his strategy, choosing an “all inclusive” solution.

  11. A Study Comparing the Pedagogical Effectiveness of Virtual Worlds and of Classical Methods

    Science.gov (United States)

    2014-08-01

    Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Virtual Worlds, Pedagogy , Comparative Study, Test of Hypothesis REPORT DOCUMENTATION...2007) says, “Immersive VR is able to provide a rich, interactive and engaging training context that in reality would be too dangerous, too expensive or...The simulation included “smoke that significantly obscures the trainees’ VR vision in some areas” and moments when the ground would collapse under

  12. Histological and clinical findings in patients with post-transplantation and classical encapsulating peritoneal sclerosis: a European multicenter study.

    Directory of Open Access Journals (Sweden)

    Joerg Latus

    Full Text Available Encapsulating peritoneal sclerosis (EPS commonly presents after peritoneal dialysis has been stopped, either post-transplantation (PT-EPS or after switching to hemodialysis (classical EPS, cEPS. The aim of the present study was to investigate whether PT-EPS and cEPS differ in morphology and clinical course.In this European multicenter study we included fifty-six EPS patients, retrospectively paired-matched for peritoneal dialysis (PD duration. Twenty-eight patients developed EPS after renal transplantation, whereas the other twenty-eight patients were classical EPS patients. Demographic data, PD details, and course of disease were documented. Peritoneal biopsies of all patients were investigated using histological criteria.Eighteen patients from the Netherlands and thirty-eight patients from Germany were included. Time on PD was 78(64-95 in the PT-EPS and 72(50-89 months in the cEPS group (p>0.05. There were no significant differences between the morphological findings of cEPS and PT-EPS. Podoplanin positive cells were a prominent feature in both groups, but with a similar distribution of the podoplanin patterns. Time between cessation of PD to the clinical diagnosis of EPS was significantly shorter in the PT-EPS group as compared to cEPS (4(2-9 months versus 23(7-24 months, p<0.001. Peritonitis rate was significantly higher in cEPS.In peritoneal biopsies PT-EPS and cEPS are not distinguishable by histomorphology and immunohistochemistry, which argues against different entities. The critical phase for PT-EPS is during the first year after transplantation and therefore earlier after PD cessation then in cEPS.

  13. Comparative study on clinically latent aggressiveness inoutpatients with schizophrenia treated with classical antipsychotics and with risperidone

    Directory of Open Access Journals (Sweden)

    Konstantinos Tsirigotis

    2014-03-01

    Full Text Available Objective: The use of neuroleptics causes not only regression of psychotic symptoms; neuroleptics affect also the patients’ mental state which is changing not only due to medications effects but also secondarily, as a result of regression of psychotic symptoms. The aim of this study was evaluation of subjectively felt “silent” (clinically latent hostility and aggressiveness in patients with paranoid schizophrenia treated with typical neuroleptics and risperidone. Material and methods: Sixty patients (30 patients treated with typical neuroleptics and the other 30 – with risperidone were examined with the Polish version of the following tools: Minnesota Multiphasic Personality Inventory (MMPI, Adjective Check List (ACL and Stern Activities Index (SAI. Results: The statistical analysis of the obtained results yielded many statistically significant differences within the intensity of hostility and aggressiveness in the examined groups. Conclusions: The results of this study showed a higher severity of psychological and personality problems in patients treated with typical neuroleptics, as compared to those treated with risperidone. In patients with paranoid schizophrenia treated with risperidone a lower severity of psychopathological, especially schizophrenic and paranoid, symptoms and lower hostility and aggressiveness were found. Considering that risperidone improves verbal functions, it can be assumed that this entails an improvement in the patients’ communicative competences, thereby improving also their interpersonal relationships. The results of this study indicate a higher susceptibility of people in this group to social influences and less hostility and negativity experienced by them.

  14. Molecular dynamics study of two- and three-dimensional classical fluids using double Yukawa potential

    Indian Academy of Sciences (India)

    Y Pathania; P K Ahluwalla

    2005-09-01

    We have carried out a molecular dynamics simulation of two- and three- dimensional double Yukawa fluids near the triple point. We have compared some of the static and dynamic correlation functions with those of Lennard{Jones, when parameters occurring in double Yukawa potential are chosen to fit Lennard-Jones potential. The results are in good agreement. However, when repulsive and attractive parameters occurring in double Yukawa potential are varied, we found distinct differences in static and dynamic correlation functions. We have also compared the two-dimensional correlation functions with those of three-dimensional to study the effect of dimensionality, near the triple point region.

  15. Novel tools, classic techniques: evolutionary studies using primate pluripotent stem cells.

    Science.gov (United States)

    Hrvoj-Mihic, Branka; Marchetto, Maria C N; Gage, Fred H; Semendeferi, Katerina; Muotri, Alysson R

    2014-06-15

    Recent applications of genomic tools on the analysis of alterations unique to our species coupled with a growing number of neuroanatomical studies across primates provide an unprecedented opportunity to compile different levels of human brain evolution into a complex whole. Applications of induced pluripotent stem cell (iPSC) technology, capable of reprogramming somatic tissue of different species and generating species-specific neuronal phenotypes, for the first time offer an opportunity to test specific evolutionary hypotheses in a field of inquiry that has been long plagued by the limited availability of research specimens. In this review, we will focus specifically on the experimental role of iPSC technology as applied to the analysis of neocortical pyramidal neurons. Pyramidal neurons emerge as particularly suitable for testing evolutionary scenarios, since they form the most common morphological class of neurons in the cortex, display morphological variations across different cortical areas and cortical layers that appear species-specific, and express unique molecular signatures. Human and nonhuman primate iPSC-derived neurons may represent a unique biological resource to elucidate the phenotypic differences between humans and other hominids. As the typical morphology of pyramidal neurons tends to be compromised in neurological disorders, application of iPSC technology to the analysis of pyramidal neurons could not only bring new insights into human adaptation but also offer opportunities to link biomedical research with studies of the origins of the human species.

  16. Trajectories of personal control in cancer patients receiving psychological care

    NARCIS (Netherlands)

    Zhu, Lei; Schroevers, Maya J.; van der Lee, Marije; Garssen, Bert; Stewart, Roy E.; Sanderman, Robbert; Ranchor, A.V.

    2015-01-01

    Objective This study aimed to (1) identify subgroups of cancer patients with distinct personal control trajectories during psychological care, (2) examine whether socio-demographic, clinical, and psychological care characteristics could distinguish trajectories, and (3) examine differential patterns

  17. Optimal trajectory and insertion accuracy of sacral alar iliac screws

    Directory of Open Access Journals (Sweden)

    Katsutaka Yamada

    2017-07-01

    Conclusion: The optimal trajectories of SAISs in a Japanese patient population are more lateral in males and more caudal in females. This study examines the clinical safety and accuracy of SAIS insertion on these optimal trajectories.

  18. Trajectories of personal control in cancer patients receiving psychological care

    NARCIS (Netherlands)

    Zhu, Lei; Schroevers, Maya J.; van der Lee, Marije; Garssen, Bert; Stewart, Roy E.; Sanderman, Robbert; Ranchor, Adelita V.

    2015-01-01

    Objective: This study aimed to (1) identify subgroups of cancer patients with distinct personal control trajectories during psychological care, (2) examine whether socio-demographic, clinical, and psychological care characteristics could distinguish trajectories, and (3) examine differential pattern

  19. Trajectories of personal control in cancer patients receiving psychological care

    NARCIS (Netherlands)

    Zhu, Lei; Schroevers, Maya J.; Lee, van der Marije; Garssen, Bert; Stewart, Roy E.; Sanderman, R.; Ranchor, A.V.

    2015-01-01

    Objective This study aimed to (1) identify subgroups of cancer patients with distinct personal control trajectories during psychological care, (2) examine whether socio-demographic, clinical, and psychological care characteristics could distinguish trajectories, and (3) examine differential patterns

  20. The influence of work-family conflict trajectories on self-rated health trajectories in Switzerland: a life course approach.

    Science.gov (United States)

    Cullati, Stéphane

    2014-07-01

    Self-rated health (SRH) trajectories tend to decline over a lifetime. Moreover, the Cumulative Advantage and Disadvantage (CAD) model indicates that SRH trajectories are known to consistently diverge along socioeconomic positions (SEP) over the life course. However, studies of working adults to consider the influence of work and family conflict (WFC) on SRH trajectories are scarce. We test the CAD model and hypothesise that SRH trajectories diverge over time according to socioeconomic positions and WFC trajectories accentuate this divergence. Using longitudinal data from the Swiss Household Panel (N = 2327 working respondents surveyed from 2004 to 2010), we first examine trajectories of SRH and potential divergence over time across age, gender, SEP and family status using latent growth curve analysis. Second, we assess changes in SRH trajectories in relation to changes in WFC trajectories and divergence in SRH trajectories according to gender, SEP and family status using parallel latent growth curve analysis. Three measures of WFC are used: exhaustion after work, difficulty disconnecting from work, and work interference in private family obligations. The results show that SRH trajectories slowly decline over time and that the rate of change is not influenced by age, gender or SEP, a result which does not support the CAD model. SRH trajectories are significantly correlated with exhaustion after work trajectories but not the other two WFC measures. When exhaustion after work trajectories are taken into account, SRH trajectories of higher educated people decline slower compared to less educated people, supporting the CAD hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Aortic root dimensions are predominantly determined by genetic factors: a classical twin study

    Energy Technology Data Exchange (ETDEWEB)

    Celeng, Csilla; Kolossvary, Marton; Kovacs, Attila; Molnar, Andrea Agnes; Szilveszter, Balint; Karolyi, Mihaly; Jermendy, Adam L.; Karady, Julia; Merkely, Bela; Maurovich-Horvat, Pal [Semmelweis University, MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Budapest (Hungary); Horvath, Tamas [Budapest University of Technology and Economics, Department of Hydrodynamic Systems, Budapest (Hungary); Tarnoki, Adam D.; Tarnoki, David L. [Semmelweis University, Department of Radiology and Oncotherapy, Budapest (Hungary); Voros, Szilard [Global Genomics Group, Atlanta, GA (United States); Jermendy, Gyoergy [Bajcsy-Zsilinszky Hospital, Medical Department, Budapest (Hungary)

    2017-06-15

    Previous studies using transthoracic echocardiography (TTE) observed moderate heritability of aortic root dimensions. Computed tomography angiography (CTA) might provide more accurate heritability estimates. Our primary aim was to assess the heritability of the aortic root with CTA. Our secondary aim was to derive TTE-based heritability and compare this with the CTA-based results. In the BUDAPEST-GLOBAL study 198 twin subjects (118 monozygotic, 80 dizygotic; age 56.1 ± 9.4 years; 126 female) underwent CTA and TTE. We assessed the diameter of the left ventricular outflow tract (LVOT), annulus, sinus of Valsalva, sinotubular junction and ascending aorta. Heritability was assessed using ACDE model (A additive genetic, C common environmental, D dominant genetic, E unique environmental factors). Based on CTA, additive genetic effects were dominant (LVOT: A = 0.67, E = 0.33; annulus: A = 0.76, E = 0.24; sinus of Valsalva: A = 0.83, E = 0.17; sinotubular junction: A = 0.82, E = 0.18; ascending aorta: A = 0.75, E = 0.25). TTE-derived measurements showed moderate to no genetic influence (LVOT: A = 0.38, E = 0.62; annulus: C = 0.47, E = 0.53; sinus of Valsalva: C = 0.63, E = 0.37; sinotubular junction: C = 0.45, E = 0.55; ascending aorta: A = 0.67, E = 0.33). CTA-based assessment suggests that aortic root dimensions are predominantly determined by genetic factors. TTE-based measurements showed moderate to no genetic influence. The choice of measurement method has substantial impact on heritability estimates. (orig.)

  2. Comparative study of lacosamide and classical sodium channel blocking antiepileptic drugs on sodium channel slow inactivation.

    Science.gov (United States)

    Niespodziany, Isabelle; Leclère, Nathalie; Vandenplas, Catherine; Foerch, Patrik; Wolff, Christian

    2013-03-01

    Many antiepileptic drugs (AEDs) exert their therapeutic activity by modifying the inactivation properties of voltage-gated sodium (Na(v) ) channels. Lacosamide is unique among AEDs in that it selectively enhances the slow inactivation component. Although numerous studies have investigated the effects of AEDs on Na(v) channel inactivation, a direct comparison of results cannot be made because of varying experimental conditions. In this study, the effects of different AEDs on Na(v) channel steady-state slow inactivation were investigated under identical experimental conditions using whole-cell patch-clamp in N1E-115 mouse neuroblastoma cells. All drugs were tested at 100 μM, and results were compared with those from time-matched control groups. Lacosamide significantly shifted the voltage dependence of Na(v) current (I(Na) ) slow inactivation toward more hyperpolarized potentials (by -33 ± 7 mV), whereas the maximal fraction of slow inactivated channels and the curve slope did not differ significantly. Neither SPM6953 (lacosamide inactive enantiomer), nor carbamazepine, nor zonisamide affected the voltage dependence of I(Na) slow inactivation, the maximal fraction of slow inactivated channels, or the curve slope. Phenytoin significantly increased the maximal fraction of slow inactivated channels (by 28% ± 9%) in a voltage-independent manner but did not affect the curve slope. Lamotrigine slightly increased the fraction of inactivated currents (by 15% ± 4%) and widened the range of the slow inactivation voltage dependence. Lamotrigine and rufinamide induced weak, but significant, shifts of I(Na) slow inactivation toward more depolarized potentials. The effects of lacosamide on Na(v) channel slow inactivation corroborate previous observations that lacosamide has a unique mode of action among AEDs that act on Na(v) channels.

  3. The impact of parental educational trajectories on their adult offspring's overweight/obesity status: a study of three generations of Swedish men and women.

    Science.gov (United States)

    Chaparro, M P; Koupil, Ilona

    2014-11-01

    The objective of this study was to investigate the impact of grandparental and parental education and parental educational trajectory on their adult offspring's overweight/obesity. We used register data from the Uppsala Birth Cohort Multigenerational Study, based on a representative cohort born in Sweden 1915-1929 (G1). Our sample included 5122 women and 11,204 men who were grandchildren of G1 (G3), their parents (G2), and grandparents. G3's overweight/obesity (BMI≥25 kg/m2) was based on pre-pregnancy weight/height for women before their first birth (average age=26 years), and measured weight/height at conscription for men (average age=18 years). G1's, G2's, and G3's highest educational attainment was obtained from routine registers and classified as low, intermediate, or high based on respective sample distributions. Parental (G2) educational trajectory was defined as change in education between their own and their highest educated parent (G1), classified into 5 categories: always advantaged (AA), upward trajectory (UT), stable-intermediate (SI), downward trajectory (DT), and always disadvantaged (AD). We used hierarchical gender-stratified logistic regression models adjusted for G3's age, education, year of BMI collection, lineage and G2's year of birth and income. Grandparental and parental education were negatively associated with men's odds of overweight/obesity and parental education affected women's overweight/obesity risk. Furthermore, men and women whose parents belonged to the UT, SI, DT, and AD groups had greater odds of overweight/obesity compared to men and women whose parents belonged to the AA group (adjusted for G3's age, year of BMI collection, lineage, and G2's year of birth). These associations were attenuated when further adjusting for parental income and G3's own education. Socioeconomic inequalities can have long-term consequences and impact the health of future generations. For overweight/obesity in concurrent young cohorts, this inequality

  4. Classical conditioning in borderline personality disorder: an fMRI study.

    Science.gov (United States)

    Krause-Utz, Annegret; Keibel-Mauchnik, Jana; Ebner-Priemer, Ulrich; Bohus, Martin; Schmahl, Christian

    2016-06-01

    Previous research suggests disturbed emotional learning and memory in borderline personality disorder (BPD). Studies investigating the neural correlates of aversive differential delay conditioning in BPD are currently lacking. We aimed to investigate acquisition, within-session extinction, between-session extinction recall, and reacquisition. We expected increased activation in the insula, amygdala, and anterior cingulate, and decreased prefrontal activation in BPD patients. During functional magnetic resonance imaging, 27 medication-free female BPD patients and 26 female healthy controls (HC) performed a differential delay aversive conditioning paradigm. An electric shock served as unconditioned stimulus, two neutral pictures as conditioned stimuli (CS+/CS-). Dependent variables were blood-oxygen-level-dependent response, skin conductance response (SCR), and subjective ratings (valence, arousal). No significant between-group differences in brain activation were found [all p(FDR) > 0.05]. Within-group comparisons for CS+unpaired > CS- revealed increased insula activity in BPD patients but not in HC during early acquisition; during late acquisition, both groups recruited fronto-parietal areas [p(FDR)  CS during extinction. During extinction recall, there was a trend for stronger SCR to CS+ > CS in BPD patients. Amygdala habituation to CS+paired (CS+ in temporal contingency with the aversive event) during acquisition was found in HC but not in patients. Our findings suggest altered temporal response patterns in terms of increased vigilance already during early acquisition and delayed extinction processes in individuals with BPD.

  5. Modeling of quantum-information processing with Ehrenfest guided trajectories: A case study with spin-boson-like couplings

    Science.gov (United States)

    Ye, Sai-Yun; Shalashilin, Dmitrii; Serafini, Alessio

    2012-09-01

    We apply a numerical method based on multiconfigurational Ehrenfest trajectories and demonstrate converged results for the Choi fidelity of an entangling quantum gate between two two-level systems interacting through a set of bosonic modes. We consider both spin-boson and rotating-wave Hamiltonians for various numbers of mediating modes (from 1 to 100) and extend our treatment to include finite temperatures. Our results apply to two-level impurities interacting with the same band of a photonic crystal or to two distant ions interacting with the same set of motional degrees of freedom.

  6. Understanding How Isotopes Affect Charge Transfer in P3HT/PCBM: A Quantum Trajectory-Electronic Structure Study with Nonlinear Quantum Corrections.

    Science.gov (United States)

    Wang, Lei; Jakowski, Jacek; Garashchuk, Sophya; Sumpter, Bobby G

    2016-09-13

    The experimentally observed effect of selective deuterium substitution on the open circuit voltage for a blend of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM; Nat. Commun. 2014, 5, 3180) is explored using a 221-atom model of a polymer-wrapped PCBM molecule. The protonic and deuteronic wave functions for the H/D isotopologues of the hexyl side chains are described within a quantum trajectory/electronic structure approach where the dynamics is performed with newly developed nonlinear corrections to the quantum forces, necessary to describe the nuclear wave functions; the classical forces are generated with a density functional tight binding method. The resulting protonic and deuteronic time-dependent wave functions are used to assess the effects of isotopic substitution (deuteration) on the energy gaps relevant to the charge transfer for the donor and acceptor electronic states. While the isotope effect on the electronic energy levels is found negligible, the quantum-induced fluctuations of the energy gap between the charge transfer and charge separated states due to nuclear wave functions may account for experimental trends by promoting charge transfer in P3HT:PCBM and increasing charge recombination on the donor in the deuterium substituted P3HT:PCBM.

  7. Trajectories of Intimate Partner Violence Victimization

    Directory of Open Access Journals (Sweden)

    Kevin M. Swartout

    2012-08-01

    Full Text Available Introduction: The purposes of this study were to assess the extent to which latent trajectories of female intimate partner violence (IPV victimization exist; and, if so, use negative childhood experiences to predict trajectory membership.Methods: We collected data from 1,575 women at 5 time-points regarding experiences during adolescence and their 4 years of college. We used latent class growth analysis to fit a series of personcentered, longitudinal models ranging from 1 to 5 trajectories. Once the best-fitting model was selected, we used negative childhood experience variables—sexual abuse, physical abuse, and witnessing domestic violence—to predict most-likely trajectory membership via multinomial logistic regression.Results: A 5-trajectory model best fit the data both statistically and in terms of interpretability. The trajectories across time were interpreted as low or no IPV, low to moderate IPV, moderate to low IPV, high to moderate IPV, and high and increasing IPV, respectively. Negative childhood experiences differentiated trajectory membership, somewhat, with childhood sexual abuse as a consistent predictor of membership in elevated IPV trajectories.Conclusion: Our analyses show how IPV risk changes over time and in different ways. These differential patterns of IPV suggest the need for prevention strategies tailored for women that consider victimization experiences in childhood and early adulthood. [West J Emerg Med. 2012;13(3:272–277.

  8. Efficient Spatial Keyword Search in Trajectory Databases

    CERN Document Server

    Cong, Gao; Ooi, Beng Chin; Zhang, Dongxiang; Zhang, Meihui

    2012-01-01

    An increasing amount of trajectory data is being annotated with text descriptions to better capture the semantics associated with locations. The fusion of spatial locations and text descriptions in trajectories engenders a new type of top-$k$ queries that take into account both aspects. Each trajectory in consideration consists of a sequence of geo-spatial locations associated with text descriptions. Given a user location $\\lambda$ and a keyword set $\\psi$, a top-$k$ query returns $k$ trajectories whose text descriptions cover the keywords $\\psi$ and that have the shortest match distance. To the best of our knowledge, previous research on querying trajectory databases has focused on trajectory data without any text description, and no existing work has studied such kind of top-$k$ queries on trajectories. This paper proposes one novel method for efficiently computing top-$k$ trajectories. The method is developed based on a new hybrid index, cell-keyword conscious B$^+$-tree, denoted by \\cellbtree, which enabl...

  9. The Diversity of Classical Archaeology

    DEFF Research Database (Denmark)

    This book is the first volume in the series Studies in Classical Archaeology, founded and edited by professors of classical archaeology, Achim Lichtenberger and Rubina Raja. This volume sets out the agenda for this series. It achieves this by familiarizing readers with a wide range of themes and ...

  10. Trajectory Browser: An Online Tool for Interplanetary Trajectory Analysis and Visualization

    Science.gov (United States)

    Foster, Cyrus James

    2013-01-01

    The trajectory browser is a web-based tool developed at the NASA Ames Research Center for finding preliminary trajectories to planetary bodies and for providing relevant launch date, time-of-flight and (Delta)V requirements. The site hosts a database of transfer trajectories from Earth to planets and small-bodies for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and (Delta)V capability, while a trajectory viewer tool allows the visualization of the heliocentric trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies.

  11. Ornithopter transition trajectories

    Science.gov (United States)

    Dietl, John M.; Garcia, Ephrahim

    2010-04-01

    The design of stable trim conditions for forward flight and for hover has been achieved. In forward flight, an ornithopter is configured like a conventional airplane or large bird. Its fuselage is essentially horizontal and the wings heave in a vertical plane. In hover, however, the body pitches vertically so that the wing stroke in the horizontal plane. Thrust directed downward, the vehicle remains aloft while the downdraft envelops the tail to provide enough flow for vehicle control and stabilization. To connect these trajectories dynamically is the goal. The naïve approach-to choose two stable trajectories and switch between them-has been accomplished. A new approach is to establish an open-loop trajectory through a trajectory optimization algorithm-optimized for shortest altitude drop, shortest stopping distance, or lowest energy consumption.

  12. Entanglement and its relationship to classical dynamics

    Science.gov (United States)

    Ruebeck, Joshua B.; Lin, Jie; Pattanayak, Arjendu K.

    2017-06-01

    We present an analysis of the entangling quantum kicked top focusing on the few qubit case and the initial condition dependence of the time-averaged entanglement SQ for spin-coherent states. We show a very strong connection between the classical phase space and the initial condition dependence of SQ even for the extreme case of two spin-1 /2 qubits. This correlation is not related directly to chaos in the classical dynamics. We introduce a measure of the behavior of a classical trajectory which correlates far better with the entanglement and show that the maps of classical and quantum initial-condition dependence are both organized around the symmetry points of the Hamiltonian. We also show clear (quasi-)periodicity in entanglement as a function of number of kicks and of kick strength.

  13. Personalized trajectory matching in spatial networks

    KAUST Repository

    Shang, Shuo

    2013-07-31

    With the increasing availability of moving-object tracking data, trajectory search and matching is increasingly important. We propose and investigate a novel problem called personalized trajectory matching (PTM). In contrast to conventional trajectory similarity search by spatial distance only, PTM takes into account the significance of each sample point in a query trajectory. A PTM query takes a trajectory with user-specified weights for each sample point in the trajectory as its argument. It returns the trajectory in an argument data set with the highest similarity to the query trajectory. We believe that this type of query may bring significant benefits to users in many popular applications such as route planning, carpooling, friend recommendation, traffic analysis, urban computing, and location-based services in general. PTM query processing faces two challenges: how to prune the search space during the query processing and how to schedule multiple so-called expansion centers effectively. To address these challenges, a novel two-phase search algorithm is proposed that carefully selects a set of expansion centers from the query trajectory and exploits upper and lower bounds to prune the search space in the spatial and temporal domains. An efficiency study reveals that the algorithm explores the minimum search space in both domains. Second, a heuristic search strategy based on priority ranking is developed to schedule the multiple expansion centers, which can further prune the search space and enhance the query efficiency. The performance of the PTM query is studied in extensive experiments based on real and synthetic trajectory data sets. © 2013 Springer-Verlag Berlin Heidelberg.

  14. Automated Cooperative Trajectories

    Science.gov (United States)

    Hanson, Curt; Pahle, Joseph; Brown, Nelson

    2015-01-01

    This presentation is an overview of the Automated Cooperative Trajectories project. An introduction to the phenomena of wake vortices is given, along with a summary of past research into the possibility of extracting energy from the wake by flying close parallel trajectories. Challenges and barriers to adoption of civilian automatic wake surfing technology are identified. A hardware-in-the-loop simulation is described that will support future research. Finally, a roadmap for future research and technology transition is proposed.

  15. Experimental observation of anomalous trajectories of single photons

    Science.gov (United States)

    Zhou, Zong-Quan; Liu, Xiao; Kedem, Yaron; Cui, Jin-Min; Li, Zong-Feng; Hua, Yi-Lin; Li, Chuan-Feng; Guo, Guang-Can

    2017-04-01

    A century after its conception, quantum mechanics still hold surprises that contradict many "common sense" notions. The contradiction is especially sharp in case one consider trajectories of truly quantum objects such as single photons. From a classical point of view, trajectories are well defined for particles, but not for waves. The wave-particle duality forces a breakdown of this dichotomy and quantum mechanics resolves this in a remarkable way: Trajectories can be well defined, but they are utterly different from classical trajectories. Here, we give an operational definition to the trajectory of a single photon by introducing a technique to mark its path using its spectral composition. The method demonstrates that the frequency degree of freedom can be used as a bona fide quantum measurement device (meter). The analysis of a number of setups, using our operational definition, leads to anomalous trajectories which are noncontinuous and in some cases do not even connect the source of the photon to where it is detected. We carried out an experimental demonstration of these anomalous trajectories using a nested interferometer. We show that the two-state vector formalism provides a simple explanation for the results.

  16. Quantum-classical path integral. I. Classical memory and weak quantum nonlocality.

    Science.gov (United States)

    Lambert, Roberto; Makri, Nancy

    2012-12-14

    We consider rigorous path integral descriptions of the dynamics of a quantum system coupled to a polyatomic environment, assuming that the latter is well approximated by classical trajectories. Earlier work has derived semiclassical or purely classical expressions for the influence functional from the environment, which should be sufficiently accurate for many situations, but the evaluation of quantum-(semi)classical path integral (QCPI) expressions has not been practical for large-scale simulation because the interaction with the environment introduces couplings nonlocal in time. In this work, we analyze the nature of the effects on a system from its environment in light of the observation [N. Makri, J. Chem. Phys. 109, 2994 (1998)] that true nonlocality in the path integral is a strictly quantum mechanical phenomenon. If the environment is classical, the path integral becomes local and can be evaluated in a stepwise fashion along classical trajectories of the free solvent. This simple "classical path" limit of QCPI captures fully the decoherence of the system via a classical mechanism. Small corrections to the classical path QCPI approximation may be obtained via an inexpensive random hop QCPI model, which accounts for some "back reaction" effects. Exploiting the finite length of nonlocality, we argue that further inclusion of quantum decoherence is possible via an iterative evaluation of the path integral. Finally, we show that the sum of the quantum amplitude factors with respect to the system paths leads to a smooth integrand as a function of trajectory initial conditions, allowing the use of Monte Carlo methods for the multidimensional phase space integral.

  17. Citation classics in trauma.

    Science.gov (United States)

    Ollerton, Joanne Emma; Sugrue, Michael

    2005-02-01

    The evolution of trauma may be analyzed by review of articles most frequently cited by scientific articles worldwide. This study identified the "trauma classics" by reviewing the most-cited articles ever published in The Journal of Trauma. The Science Citation Index of the Institute for Scientific Information was searched for the 50 most-cited articles in The Journal of Trauma. Of the 12,672 articles published since 1961, 80 were cited over 100 times and 17 over 200 times. The most-cited article was by Baker, a hallmark publication on injury scoring published in 1974. Feeding postinjury, bacterial translocation, and multiple organ failure were common themes. Overall, 32% involved gastrointestinal topics and 18% involved injury scoring, with institutions in the United States publishing 80% of the articles. This study identified the trauma classics from the last 42 years of The Journal of Trauma. Citation analysis has recognized limitations but gives a fascinating insight into the evolution of trauma care.

  18. Injuries in classical ballet

    Directory of Open Access Journals (Sweden)

    Adriana Coutinho de Azevedo Guimarães

    2008-06-01

    Full Text Available This study aimed to elucidate what injuries are most likely to occur due to classical ballet practice. The research used national and international bibliography. The bibliography analysis indicated that technical and esthetical demands lead to a practice of non-anatomical movements, causing the ballet dancer to suffer from a number of associated lesions. Most of the injuries are caused by technical mistakes and wrong training. Troubles in children are usually due to trying to force external rotation at hip level and to undue use of point ballet slippers. The commonest lesions are in feet and ankles, followed by knees and hips. The rarest ones are in the upper limbs. These injuries are caused by exercise excess, by repetitions always in the same side and by wrong and early use of point slippers. The study reached the conclusion that incorrect application of classical ballet technique predisposes the dancers to characteristic injuries.

  19. Finite size effects in the presence of a chemical potential: A study in the classical nonlinear O(2) sigma model

    Science.gov (United States)

    Banerjee, Debasish; Chandrasekharan, Shailesh

    2010-06-01

    In the presence of a chemical potential, the physics of level crossings leads to singularities at zero temperature, even when the spatial volume is finite. These singularities are smoothed out at a finite temperature but leave behind nontrivial finite size effects which must be understood in order to extract thermodynamic quantities using Monte Carlo methods, particularly close to critical points. We illustrate some of these issues using the classical nonlinear O(2) sigma model with a coupling β and chemical potential μ on a 2+1-dimensional Euclidean lattice. In the conventional formulation this model suffers from a sign problem at nonzero chemical potential and hence cannot be studied with the Wolff cluster algorithm. However, when formulated in terms of the worldline of particles, the sign problem is absent, and the model can be studied efficiently with the “worm algorithm.” Using this method we study the finite size effects that arise due to the chemical potential and develop an effective quantum mechanical approach to capture the effects. As a side result we obtain energy levels of up to four particles as a function of the box size and uncover a part of the phase diagram in the (β,μ) plane.

  20. Genome-wide association study of classical Hodgkin lymphoma and Epstein-Barr virus status-defined subgroups.

    LENUS (Irish Health Repository)

    Urayama, Kevin Y

    2012-02-08

    Accumulating evidence suggests that risk factors for classical Hodgkin lymphoma (cHL) differ by tumor Epstein-Barr virus (EBV) status. This potential etiological heterogeneity is not recognized in current disease classification.

  1. Fast forward to the classical adiabatic invariant

    CERN Document Server

    Jarzynski, Christopher; Patra, Ayoti; Subaşı, Yiğit

    2016-01-01

    We show how the classical action, an adiabatic invariant, can be preserved under non-adiabatic conditions. Specifically, for a time-dependent Hamiltonian $H = p^2/2m + U(q,t)$ in one degree of freedom, and for an arbitrary choice of action $I_0$, we construct a "fast-forward" potential energy function $V_{\\rm FF}(q,t)$ that, when added to $H$, guides all trajectories with initial action $I_0$ to end with the same value of action. We use this result to construct a local dynamical invariant $J(q,p,t)$ whose value remains constant along these trajectories. We illustrate our results with numerical simulations. Finally, we sketch how our classical results may be used to design approximate quantum shortcuts to adiabaticity.

  2. Developmental trajectory from early responses to transgressions to future antisocial behavior: evidence for the role of the parent-child relationship from two longitudinal studies.

    Science.gov (United States)

    Kim, Sanghag; Kochanska, Grazyna; Boldt, Lea J; Nordling, Jamie Koenig; O'Bleness, Jessica J

    2014-02-01

    Parent-child relationships are critical in development, but much remains to be learned about the mechanisms of their impact. We examined the early parent-child relationship as a moderator of the developmental trajectory from children's affective and behavioral responses to transgressions to future antisocial, externalizing behavior problems in the Family Study (102 community mothers, fathers, and infants, followed through age 8) and the Play Study (186 low-income, diverse mothers and toddlers, followed for 10 months). The relationship quality was indexed by attachment security in the Family Study and maternal responsiveness in the Play Study. Responses to transgressions (tense discomfort and reparation) were observed in laboratory mishaps wherein children believed they had damaged a valued object. Antisocial outcomes were rated by parents. In both studies, early relationships moderated the future developmental trajectory: diminished tense discomfort predicted more antisocial outcomes, but only in insecure or unresponsive relationships. That risk was defused in secure or responsive relationships. Moderated mediation analyses in the Family Study indicated that the links between diminished tense discomfort and future antisocial behavior in insecure parent-child dyads were mediated by stronger discipline pressure from parents. By indirectly influencing future developmental sequelae, early relationships may increase or decrease the probability that the parent-child dyad will embark on a path toward antisocial outcomes.

  3. Developmental Trajectories of Childhood Obesity and Risk Behaviors in Adolescence

    Science.gov (United States)

    Huang, David Y. C.; Lanza, H. Isabella; Wright-Volel, Kynna; Anglin, M. Douglas

    2013-01-01

    Using group-based trajectory modeling, this study examined 5156 adolescents from the child sample of the 1979 National Longitudinal Survey of Youth to identify developmental trajectories of obesity from ages 6-18 and evaluate associations of such trajectories with risk behaviors and psychosocial health in adolescence. Four distinctive obesity…

  4. Developmental Trajectories of Childhood Obesity and Risk Behaviors in Adolescence

    Science.gov (United States)

    Huang, David Y. C.; Lanza, H. Isabella; Wright-Volel, Kynna; Anglin, M. Douglas

    2013-01-01

    Using group-based trajectory modeling, this study examined 5156 adolescents from the child sample of the 1979 National Longitudinal Survey of Youth to identify developmental trajectories of obesity from ages 6-18 and evaluate associations of such trajectories with risk behaviors and psychosocial health in adolescence. Four distinctive obesity…

  5. Saguenay Youth Study: A multi-generational approach to studying virtual trajectories of the brain and cardio-metabolic health

    Directory of Open Access Journals (Sweden)

    T. Paus

    2015-02-01

    Full Text Available This paper provides an overview of the Saguenay Youth Study (SYS and its parental arm. The overarching goal of this effort is to develop trans-generational models of developmental cascades contributing to the emergence of common chronic disorders, such as depression, addictions, dementia and cardio-metabolic diseases. Over the past 10 years, we have acquired detailed brain and cardio-metabolic phenotypes, and genome-wide genotypes, in 1029 adolescents recruited in a population with a known genetic founder effect. At present, we are extending this dataset to acquire comparable phenotypes and genotypes in the biological parents of these individuals. After providing conceptual background for this work (transactions across time, systems and organs, we describe briefly the tools employed in the adolescent arm of this cohort and highlight some of the initial accomplishments. We then outline in detail the phenotyping protocol used to acquire comparable data in the parents.

  6. Developmental Trajectory of Audiovisual Speech Integration in Early Infancy. A Review of Studies Using the McGurk Paradigm

    Directory of Open Access Journals (Sweden)

    Tomalski Przemysław

    2015-10-01

    Full Text Available Apart from their remarkable phonological skills young infants prior to their first birthday show ability to match the mouth articulation they see with the speech sounds they hear. They are able to detect the audiovisual conflict of speech and to selectively attend to articulating mouth depending on audiovisual congruency. Early audiovisual speech processing is an important aspect of language development, related not only to phonological knowledge, but also to language production during subsequent years. Th is article reviews recent experimental work delineating the complex developmental trajectory of audiovisual mismatch detection. Th e central issue is the role of age-related changes in visual scanning of audiovisual speech and the corresponding changes in neural signatures of audiovisual speech processing in the second half of the first year of life. Th is phenomenon is discussed in the context of recent theories of perceptual development and existing data on the neural organisation of the infant ‘social brain’.

  7. Trajectories of point particles in cosmology and the Zel'dovich approximation

    CERN Document Server

    Bartelmann, Matthias

    2014-01-01

    Using a Green's function approach, we compare the trajectories of classical Hamiltonian point particles in an expanding space-time to the effectively inertial trajectories in the Zel'dovich approximation. It is shown that the effective gravitational potential accelerating the particles relative to the Zel'dovich trajectories vanishes exactly initially as a consequence of the continuity equation, and acts only during a short, early period. The Green's function approach suggests an iterative scheme for improving the Zel'dovich trajectories, which can be analytically solved. We construct these trajectories explicitly and show how they interpolate between the Zel'dovich and the exact trajectories. The effective gravitational potential acting on the improved trajectories is substantially smaller at late times than the potential acting on the exact trajectories. The results may be useful for Lagrangian perturbation theory and for numerical simulations.

  8. An experimental study of visual flight trajectory tracking and pose prediction for the automatic computer control of a miniature airship

    Science.gov (United States)

    Haecker, Jens; Kroeplin, Bernd H.

    2003-08-01

    This paper describes our current work in developing a vision-based tracking and trajectory prediction system for an aerial robot based on low-cost digital cameras, image processing techniques, and a filtering and prediction algorithm. The system determines the pose (location and orientation) of a miniature airship, online during indoor flight, and will be used in a development framework for a future autonomous flight control system. Object localization is achieved by tracking an infra-red target array mounted to a model airship. Its pose in three-dimensional space can be computed from corresponding points in the images of two cameras which are calibrated in a global coordinate system. The calibration procedure and the localization, as well as some aspects of the measurement accuracy achieved, are discussed. Real-world applications provide an uncertain static or dynamic environment which complicates the tracking of a target. To overcome problems due to noisy data or even failed target detection in image frames, a filtering procedure is applied for estimating the airship's pose. In a first step, points in the two-dimensional image planes are directly tracked and propagated forward to the vehicle pose. In a second step, an adaptive noise Kalman filter is applied for estimating and predicting the flight trajectory. Its state is propagated back to points in the image planes to guide the detection algorithm by defining regions of confidence. Both approaches are combined in a tracking algorithm. In-flight measurements are used to validate the parameters of the adaption procedure. Some experimental results are shown.

  9. Classical field theory

    CERN Document Server

    Franklin, Joel

    2017-01-01

    Classical field theory, which concerns the generation and interaction of fields, is a logical precursor to quantum field theory, and can be used to describe phenomena such as gravity and electromagnetism. Written for advanced undergraduates, and appropriate for graduate level classes, this book provides a comprehensive introduction to field theories, with a focus on their relativistic structural elements. Such structural notions enable a deeper understanding of Maxwell's equations, which lie at the heart of electromagnetism, and can also be applied to modern variants such as Chern–Simons and Born–Infeld. The structure of field theories and their physical predictions are illustrated with compelling examples, making this book perfect as a text in a dedicated field theory course, for self-study, or as a reference for those interested in classical field theory, advanced electromagnetism, or general relativity. Demonstrating a modern approach to model building, this text is also ideal for students of theoretic...

  10. Classical Weyl Transverse Gravity

    CERN Document Server

    Oda, Ichiro

    2016-01-01

    We study various classical aspects of the Weyl transverse (WTDiff) gravity in a general space-time dimension. First of all, we clarify a classical equivalence among three kinds of gravitational theories, those are, the conformally-invariant scalar tensor gravity, Einstein's general relativity and the WTDiff gravity via the gauge fixing procedure. Secondly, we show that in the WTDiff gravity the cosmological constant is a mere integration constant as in unimodular gravity, but it does not receive any radiative corrections unlike the unimodular gravity. A key point in this proof is to construct a covariantly conserved energy-momentum tensor, which is achieved on the basis of this equivalence relation. Thirdly, we demonstrate that the Noether current for the Weyl transformation is identically vanishing, thereby implying that the Weyl symmetry existing in both the conformally-invariant scalar tensor gravity and the WTDiff gravity is a "fake" symmetry. We find it possible to extend this proof to all matter fields,...

  11. Childhood body mass index trajectories: modeling, characterizing, pairwise correlations and socio-demographic predictors of trajectory characteristics

    OpenAIRE

    Wen Xiaozhong; Kleinman Ken; Gillman Matthew W; Rifas-Shiman Sheryl L; Taveras Elsie M

    2012-01-01

    Abstract Background Modeling childhood body mass index (BMI) trajectories, versus estimating change in BMI between specific ages, may improve prediction of later body-size-related outcomes. Prior studies of BMI trajectories are limited by restricted age periods and insufficient use of trajectory information. Methods Among 3,289 children seen at 81,550 pediatric well-child visits from infancy to 18 years between 1980 and 2008, we fit individual BMI trajectories using mixed effect models with f...

  12. Mechanistic and comparative studies of melatonin and classic antioxidants in terms of their interactions with the ABTS cation radical.

    Science.gov (United States)

    Tan, Dun-xian; Hardeland, Rüdiger; Manchester, Lucien C; Poeggeler, Burkhard; Lopez-Burillo, Silvia; Mayo, Juan C; Sainz, Rosa M; Reiter, Russel J

    2003-05-01

    Melatonin and classic antioxidants possess the capacity to scavenge ABTSb+ with IC50s of 4, 11, 15.5, 15.5, 17 and 21 microm for melatonin, glutathione, vitamin C, trolox, NADH and NADPH, respectively. In terms of scavenging ABTSb+, melatonin exhibits a different profile than that of the classic antioxidants. Classic antioxidants scavenge one or less ABTSb+, while each melatonin molecule can scavenge more than one ABTSb+, probably with a maximum of four. Classic antioxidants do not synergize when combined in terms of scavenging ABTSb+. However, a synergistic action is observed when melatonin is combined with any of the classic antioxidants. Cyclic voltammetry indicates that melatonin donates an electron at the potential of 715 mV. The scavenging mechanism of melatonin on ABTSb+ may involve multiple-electron donations via intermediates through a stepwise process. Intermediates including the melatoninyl cation radical, the melatoninyl neutral radical and cyclic 3-hydroxymelatonin (cyclic 3-OHM) and N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) seem to participate in these reactions. More interestingly, the pH of the solution dramatically modifies the ABTSb+ scavenging capacity of melatonin while pH changes have no measurable influence on the scavenging activity of classic antioxidants. An acidic pH markedly reduces the ABTSb+ scavenging capacity of melatonin while an increased pH promotes the interaction of melatonin and ABTSb+. The major melatonin metabolites that develop when melatonin interacts with ABTSb+ are cyclic 3-OHM and AFMK. Cyclic 3-OHM is the intermediate between melatonin and AFMK, and cyclic 3-OHM also has the ability to scavenge ABTSb+. Melatonin and the metabolites which are generated via the interaction of melatonin with ABTSb+, i.e. the melatoninyl cation radical, melatoninyl neutral radical and cyclic 3-OHM, all scavenge ABTSb+. This unique cascade action of melatonin, in terms of scavenging, increases its efficiency to neutralized ABTSb+; this

  13. A descriptive study of the prevalence of atypical and classical scrapie in sheep in 20 European countries

    Directory of Open Access Journals (Sweden)

    Calavas Didier

    2008-06-01

    Full Text Available Abstract Background The development of active surveillance programmes for transmissible spongiform encephalopathies of small ruminants across Europe has led to the recent identification of a previously undetected form of ovine prion disease, 'atypical' scrapie. Knowledge of the epidemiology of this disease is still limited, as is whether it represents a risk for animal and/or public health. The detection of atypical scrapie has been related to the use of only some of the EU agreed rapid tests. Information about the rapid tests used is not, as yet, available from public reports on the surveillance of transmissible spongiform encephalopathies in small ruminants. We collected detailed results of active surveillance from European countries to estimate and to compare the prevalence of atypical scrapie and classical scrapie in sheep for each country stratified by each surveillance stream; healthy slaughtered and found dead adult sheep. Results From the 20 participating countries, it appeared that atypical scrapie was detected in Europe wherever the conditions necessary for its diagnosis were present. In most countries, atypical scrapie and classical scrapie occurred at low prevalence level. The classical scrapie prevalence estimates were more variable than those for atypical scrapie, which appeared remarkably homogeneous across countries, surveillance streams and calendar years of surveillance. Differences were observed in the age and genotype of atypical scrapie and classical scrapie cases that are consistent with previous published findings. Conclusion This work suggests that atypical scrapie is not rare compared to classical scrapie. The homogeneity of its prevalence, whatever the country, stream of surveillance or year of detection, contrasts with the epidemiological pattern of classical scrapie. This suggests that the aetiology of atypical scrapie differs from that of classical scrapie.

  14. What classicality? Decoherence and Bohr's classical concepts

    CERN Document Server

    Schlosshauer, Maximilian

    2010-01-01

    Niels Bohr famously insisted on the indispensability of what he termed "classical concepts." In the context of the decoherence program, on the other hand, it has become fashionable to talk about the "dynamical emergence of classicality" from the quantum formalism alone. Does this mean that decoherence challenges Bohr's dictum and signifies a break with the Copenhagen interpretation-for example, that classical concepts do not need to be assumed but can be derived? In this paper we'll try to shine some light down the murky waters where formalism and philosophy cohabitate. To begin, we'll clarify the notion of classicality in the decoherence description. We'll then discuss Bohr's and Heisenberg's take on the quantum-classical problem and reflect on different meanings of the terms "classicality" and "classical concepts" in the writings of Bohr and his followers. This analysis will allow us to put forward some tentative suggestions for how we may better understand the relation between decoherence-induced classical...

  15. A Comprehensive Study of Hydrogen Adsorbing to Amorphous Water-Ice: Defining Adsorption in Classical Molecular Dynamics

    CERN Document Server

    Dupuy, John L; Stancil, P C

    2016-01-01

    Gas-grain and gas-phase reactions dominate the formation of molecules in the interstellar medium (ISM). Gas-grain reactions require a substrate (e.g. a dust or ice grain) on which the reaction is able to occur. The formation of molecular hydrogen (H$_2$) in the ISM is the prototypical example of a gas-grain reaction. In these reactions, an atom of hydrogen will strike a surface, stick to it, and diffuse across it. When it encounters another adsorbed hydrogen atom, the two can react to form molecular hydrogen and then be ejected from the surface by the energy released in the reaction. We perform in-depth classical molecular dynamics (MD) simulations of hydrogen atoms interacting with an amorphous water-ice surface. This study focuses on the first step in the formation process; the sticking of the hydrogen atom to the substrate. We find that careful attention must be paid in dealing with the ambiguities in defining a sticking event. The technical definition of a sticking event will affect the computed sticking ...

  16. Classical force field for hydrofluorocarbon molecular simulations. Application to the study of gas solubility in poly(vinylidene fluoride).

    Science.gov (United States)

    Lachet, V; Teuler, J-M; Rousseau, B

    2015-01-08

    A classical all-atoms force field for molecular simulations of hydrofluorocarbons (HFCs) has been developed. Lennard-Jones force centers plus point charges are used to represent dispersion-repulsion and electrostatic interactions. Parametrization of this force field has been performed iteratively using three target properties of pentafluorobutane: the quantum energy of an isolated molecule, the dielectric constant in the liquid phase, and the compressed liquid density. The accuracy and transferability of this new force field has been demonstrated through the simulation of different thermophysical properties of several fluorinated compounds, showing significant improvements compared to existing models. This new force field has been applied to study solubilities of several gases in poly(vinylidene fluoride) (PVDF) above the melting temperature of this polymer. The solubility of CH4, CO2, H2S, H2, N2, O2, and H2O at infinite dilution has been computed using test particle insertions in the course of a NpT hybrid Monte Carlo simulation. For CH4, CO2, and their mixtures, some calculations beyond the Henry regime have also been performed using hybrid Monte Carlo simulations in the osmotic ensemble, allowing both swelling and solubility determination. An ideal mixing behavior is observed, with identical solubility coefficients in the mixtures and in pure gas systems.

  17. Moon Landing Trajectory Optimization

    Directory of Open Access Journals (Sweden)

    Ibrahim Mustafa MEHEDI

    2016-03-01

    Full Text Available Trajectory optimization is a crucial process during the planning phase of a spacecraft landing mission. Once a trajectory is determined, guidance algorithms are created to guide the vehicle along the given trajectory. Because fuel mass is a major driver of the total vehicle mass, and thus mission cost, the objective of most guidance algorithms is to minimize the required fuel consumption. Most of the existing algorithms are termed as “near-optimal” regarding fuel expenditure. The question arises as to how close to optimal are these guidance algorithms. To answer this question, numerical trajectory optimization techniques are often required. With the emergence of improved processing power and the application of new methods, more direct approaches may be employed to achieve high accuracy without the associated difficulties in computation or pre-existing knowledge of the solution. An example of such an approach is DIDO optimization. This technique is applied in the current research to find these minimum fuel optimal trajectories.

  18. [Oxaliplatin -- A 10-Year Trajectory].

    Science.gov (United States)

    Kanaji, Shingo; Oki, Eiji; Saeki, Hiroshi; Kitao, Hiroyuki; Maehara, Yoshihiko; Kakeji, Yoshihiro

    2016-06-01

    Oxaliplatin(Elplat(®)iv infusion solution)is a third-generation 1,2-DACH-platinum derivative. A number of international clinical trials have investigated the effects of this drug for each of its four indications. Building on the results of these earlier studies, much research has also been carried out in Japan in terms of developing and accumulating evidence on oxaliplatin. This report reviews the trajectory of its use over the last 10-years and considers its future potential.

  19. Periodic billiard trajectories in polyhedra

    CERN Document Server

    Bedaride, Nicolas

    2011-01-01

    We consider the billiard map inside a polyhedron. We give a condition for the stability of the periodic trajectories. We apply this result to the case of the tetrahedron. We deduce the existence of an open set of tetrahedra which have a periodic orbit of length four (generalization of Fagnano's orbit for triangles), moreover we can study completly the orbit of points along this coding.

  20. Classical Weyl transverse gravity

    Energy Technology Data Exchange (ETDEWEB)

    Oda, Ichiro [University of the Ryukyus, Department of Physics, Faculty of Science, Nishihara, Okinawa (Japan)

    2017-05-15

    We study various classical aspects of the Weyl transverse (WTDiff) gravity in a general space-time dimension. First of all, we clarify a classical equivalence among three kinds of gravitational theories, those are, the conformally invariant scalar tensor gravity, Einstein's general relativity and the WTDiff gravity via the gauge-fixing procedure. Secondly, we show that in the WTDiff gravity the cosmological constant is a mere integration constant as in unimodular gravity, but it does not receive any radiative corrections unlike the unimodular gravity. A key point in this proof is to construct a covariantly conserved energy-momentum tensor, which is achieved on the basis of this equivalence relation. Thirdly, we demonstrate that the Noether current for the Weyl transformation is identically vanishing, thereby implying that the Weyl symmetry existing in both the conformally invariant scalar tensor gravity and the WTDiff gravity is a ''fake'' symmetry. We find it possible to extend this proof to all matter fields, i.e. the Weyl-invariant scalar, vector and spinor fields. Fourthly, it is explicitly shown that in the WTDiff gravity the Schwarzschild black hole metric and a charged black hole one are classical solutions to the equations of motion only when they are expressed in the Cartesian coordinate system. Finally, we consider the Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology and provide some exact solutions. (orig.)

  1. Evaluating Trajectory Queries over Imprecise Location Data

    DEFF Research Database (Denmark)

    Xie, Scott, Xike; Cheng, Reynold; Yiu, Man Lung

    2012-01-01

    Trajectory queries, which retrieve nearby objects for every point of a given route, can be used to identify alerts of potential threats along a vessel route, or monitor the adjacent rescuers to a travel path. However, the locations of these objects (e.g., threats, succours) may not be precisely......, the query is quite time-consuming, since all the points on the trajectory are considered. In this paper, we study how to efficiently evaluate trajectory queries over imprecise location data, by proposing a new concept called the u-bisector. In general, the u-bisector is an extension of bisector to handle...

  2. Observation of nondispersing classical-like molecular rotation

    CERN Document Server

    Korobenko, Aleksey; Milner, Valery

    2014-01-01

    Using the technique of an optical centrifuge, we produce rotational wave packets which evolve in time along either classical-like or non-classical trajectories. After releasing O2 and D2 molecules from the centrifuge, we track their field-free rotation by monitoring the molecular angular distribution with velocity map imaging. Due to the dispersion of the created rotational wave packets in oxygen, we observe a gradual transition between "dumbbell"-shaped and "cross"-shaped distributions, both rotating with a classical rotation frequency. In deuterium, a much narrower rotational wave packet is produced and shown to evolve in a truly classical non-dispersing fashion.

  3. Age trajectories of stroke case fatality

    DEFF Research Database (Denmark)

    Olsen, Tom Skyhøj; Andersen, Zorana Jovanovic; Andersen, Klaus Kaae

    2011-01-01

    Mortality rates level off at older ages. Age trajectories of stroke case-fatality rates were studied with the aim of investigating prevalence of this phenomenon, specifically in case-fatality rates at older ages.......Mortality rates level off at older ages. Age trajectories of stroke case-fatality rates were studied with the aim of investigating prevalence of this phenomenon, specifically in case-fatality rates at older ages....

  4. Geometric diffusion of quantum trajectories.

    Science.gov (United States)

    Yang, Fan; Liu, Ren-Bao

    2015-07-16

    A quantum object can acquire a geometric phase (such as Berry phases and Aharonov-Bohm phases) when evolving along a path in a parameter space with non-trivial gauge structures. Inherent to quantum evolutions of wavepackets, quantum diffusion occurs along quantum trajectories. Here we show that quantum diffusion can also be geometric as characterized by the imaginary part of a geometric phase. The geometric quantum diffusion results from interference between different instantaneous eigenstate pathways which have different geometric phases during the adiabatic evolution. As a specific example, we study the quantum trajectories of optically excited electron-hole pairs in time-reversal symmetric insulators, driven by an elliptically polarized terahertz field. The imaginary geometric phase manifests itself as elliptical polarization in the terahertz sideband generation. The geometric quantum diffusion adds a new dimension to geometric phases and may have applications in many fields of physics, e.g., transport in topological insulators and novel electro-optical effects.

  5. Non-linear dynamics, entanglement and the quantum-classical crossover of two coupled SQUID rings

    CERN Document Server

    Everitt, M J

    2009-01-01

    We explore the quantum-classical crossover of two coupled, identical, superconducting quantum interference device (SQUID) rings. We note that the motivation for this work is based on a study of a similar system comprising two coupled Duffing oscillators. In that work we showed that the entanglement characteristics of chaotic and periodic (entrained) solutions differed significantly and that in the classical limit entanglement was preserved only in the chaotic-like solutions. However, Duffing oscillators are a highly idealised toy model. Motivated by a wish to explore more experimentally realisable systems we now extend our work to an analysis of two coupled SQUID rings. We observe some differences in behaviour between the system that is based on SQUID rings rather than on Duffing oscillators. However, we show that the two systems share a common feature. That is, even when the SQUID ring's trajectories appear to follow (semi) classical orbits entanglement persists.

  6. Quantum, classical and semiclassical analyses of photon statistics in harmonic generation

    CERN Document Server

    Bajer, J; Bajer, Jiri; Miranowicz, Adam

    2001-01-01

    In this review, we compare different descriptions of photon-number statistics in harmonic generation processes within quantum, classical and semiclassical approaches. First, we study the exact quantum evolution of the harmonic generation by applying numerical methods including those of Hamiltonian diagonalization and global characteristics. We show explicitly that the harmonic generations can indeed serve as a source of nonclassical light. Then, we demonstrate that the quasi-stationary sub-Poissonian light can be generated in these quantum processes under conditions corresponding to the so-called no-energy-transfer regime known in classical nonlinear optics. By applying method of classical trajectories, we demonstrate that the analytical predictions of the Fano factors are in good agreement with the quantum results. On comparing second and higher harmonic generations in the no-energy-transfer regime, we show that the highest noise reduction is achieved in third-harmonic generation with the Fano-factor of the ...

  7. Period studies of classical Algol-type binaries II: UX Leo, RW Mon, EQ Ori, XZ UMa and AX Vul

    Science.gov (United States)

    Soydugan, F.; Erdem, A.; Doğru, S. S.; Aliçavuş, F.; Soydugan, E.; Çiçek, C.; Demircan, O.

    2011-07-01

    This study presents an investigation of the orbital period variations of five Algol type binaries, UX Leo, RW Mon, EQ Ori, XZ UMa and AX Vul based on all available minima times. The O- C diagrams of all systems exhibit a periodic variation superimposed on a downward parabolic segment. The mass loss due to magnetic braking effect in the cooler components is assumed to account for the parabolic variation with a downward shape, while it is suggested that the light-time effect (LITE) due to an unseen component around the eclipsing binaries explains the tilted sinusoidal changes in their O- C diagrams. The orbital period decrease rates for the systems are estimated as approximately between about 0.7 and 2.5 s per century. It is clearly seen that mass loss effect is more dominant than the expected mass transfer for classical Algols in this study. The minimum mass of the probable third bodies around the eclipsing pairs was calculated to be ⩽0.5 M ⊙ except for UX Leo, in which it was estimated to be approximately 0.9 M ⊙. In order to search for third lights in the light curves of five systems, the V-light curves of the systems were analyzed and their physical and photometric parameters were determined. For UX Leo, a significant third light contribution was determined. We found a very small third light that can be tested using multi-color light curves, for RW Mon, EQ Ori and XZ UMa, while a third light for AX Vul could not be exposed.

  8. Accuracy of targeted wire guided tube thoracostomy in comparison to classical surgical chest tube placement - A clinical study.

    Science.gov (United States)

    Protic, Alen; Barkovic, Igor; Ivancic, Aldo; Kricka, Ozren; Zuvic-Butorac, Marta; Sustic, Alan

    2015-11-01

    Chest tube malfunction, after the tube thoracostomy, is often the result of an inappropriate chest tube tip position. The aim of this study was to analyse the precision of chest tube placement using the targeted wire guide technique (TWG technique) with curve dilator and to compare it to the classical surgical technique (CS technique). In this clinical study 80 patients with an indication for thoracic drainage, due to pneumothorax or pleural effusion were included. Experimental group contained 39 patients whose chest tube was placed using the TWG technique. The control group contained 41 patients whose chest tube was placed using the CS technique. The comparison of the outcomes of the two techniques applied suggests that the TWG technique was significantly more successful in achieving adequate (precise) chest tube placement, irrespective of patient diagnosis (TWG vs. CS in all patients, 78.4% vs. 36.6%, p<0.001). In the pleural effusion group, TWG and CS had success rates of 78.2% and 37.5% (p=0.005), respectively, while in pneumothorax group, TWG and CS had success rates of 78.6% and 35.3% (p=0.029), respectively. Using a curved dilator and the TWG technique for the thoracic drainage procedure we found statistically significant advantage to the TWG technique in comparison to the CS technique (78% vs. 37%) regarding precise chest tube placement within the pleural cavity. Introducing the materials and technique used in this clinical trial into clinical practice may improve the quality of thoracic drainage, including residual volume of air and/or fluid, poor functioning of the chest tube, and, as a consequence of both, prolonged hospitalisation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Patterns of neurovascular compression in patients with classic trigeminal neuralgia: A high-resolution MRI-based study

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzoni, Jose, E-mail: jls@med.puc.cl [Department of Neurosurgery, School of Medicine, Pontificia Universidad Catolica de Chile (Chile); David, Philippe, E-mail: pdavid@ulb.ac.be [Department of Radiology, Hopital Erasme, Universite Libre de Bruxelles, Brussels (Belgium); Levivier, Marc, E-mail: marc.levivier@chuv.ch [Department of Neurosurgery, Centre Hopitalier Universitaire Vaudois, Universite de Lausanne (Switzerland)

    2012-08-15

    Purpose: To describe the anatomical characteristics and patterns of neurovascular compression in patients suffering classic trigeminal neuralgia (CTN), using high-resolution magnetic resonance imaging (MRI). Materials and methods: The analysis of the anatomy of the trigeminal nerve, brain stem and the vascular structures related to this nerve was made in 100 consecutive patients treated with a Gamma Knife radiosurgery for CTN between December 1999 and September 2004. MRI studies (T1, T1 enhanced and T2-SPIR) with axial, coronal and sagital simultaneous visualization were dynamically assessed using the software GammaPlan Trade-Mark-Sign . Three-dimensional reconstructions were also developed in some representative cases. Results: In 93 patients (93%), there were one or several vascular structures in contact, either, with the trigeminal nerve, or close to its origin in the pons. The superior cerebellar artery was involved in 71 cases (76%). Other vessels identified were the antero-inferior cerebellar artery, the basilar artery, the vertebral artery, and some venous structures. Vascular compression was found anywhere along the trigeminal nerve. The mean distance between the nerve compression and the origin of the nerve in the brainstem was 3.76 {+-} 2.9 mm (range 0-9.8 mm). In 39 patients (42%), the vascular compression was located proximally and in 42 (45%) the compression was located distally. Nerve dislocation or distortion by the vessel was observed in 30 cases (32%). Conclusions: The findings of this study are similar to those reported in surgical and autopsy series. This non-invasive MRI-based approach could be useful for diagnostic and therapeutic decisions in CTN, and it could help to understand its pathogenesis.

  10. Evaluation of a classical unani pharmacopeial formulation safoof-e-muhazzil in hyperlipidemia: A randomized, standard controlled clinical study

    Directory of Open Access Journals (Sweden)

    Umar Jahangir

    2014-01-01

    Full Text Available Aim of the Study: The aim of the following study is to evaluate the efficacy and tolerability of a compound Unani formulation in hyperlipidemia on clinical and biochemical parameters. Materials and Methods: A total of 90 patients with total cholesterol level of 220 mg/dl and above were included. In Group ′A′ thirty patients with total cholesterol 243.5 ± 5.294 mg/dl received Unani formulation safoof-e-muhazzil (SM in its classical powder form 5 g twice daily orally, in Group ′B′ thirty patients with total cholesterol 234 ± 3.822 mg/dl received the SM but in compressed tablet form in the same dosage and in Group ′C′ 30 patients with total cholesterol 242.7 ± 5.563 mg/dl received atorvastatin 10 mg as a standard control. Follow-up was carried out on second, fourth and 6th week and patients were evaluated on clinical as well as biochemical parameters. Results: Group A before treatment had mean total cholesterol of 243.5 ± 5.294 mg/dl which decreased significantly after treatment to 225.6 ± 5.953 mg/dl (P 0.5 relief in palpitation and 26.17% (P < 0.001 relief in dyspnea post-treatment. Group B fatigue decreased significantly by 18.14% (P < 0.01, palpitation by 22.91% (P < 0.01 and dyspnea by 20.46% (P < 0.01. In Group C a non-significant increase of 2.2% was observed in fatigue post-treatment, palpitation decreased by 10.22% non-significantly and dyspnea decreased significantly by 17.64% (P < 0.001. Results indicate that the test drug safely and effectively ameliorates the clinical condition of patients with hyperlipidemia while decreasing cholesterol level as well.

  11. Generalization of classical mechanics for nuclear motions on nonadiabatically coupled potential energy surfaces in chemical reactions.

    Science.gov (United States)

    Takatsuka, Kazuo

    2007-10-18

    Classical trajectory study of nuclear motion on the Born-Oppenheimer potential energy surfaces is now one of the standard methods of chemical dynamics. In particular, this approach is inevitable in the studies of large molecular systems. However, as soon as more than a single potential energy surface is involved due to nonadiabatic coupling, such a naive application of classical mechanics loses its theoretical foundation. This is a classic and fundamental issue in the foundation of chemistry. To cope with this problem, we propose a generalization of classical mechanics that provides a path even in cases where multiple potential energy surfaces are involved in a single event and the Born-Oppenheimer approximation breaks down. This generalization is made by diagonalization of the matrix representation of nuclear forces in nonadiabatic dynamics, which is derived from a mixed quantum-classical representation of the electron-nucleus entangled Hamiltonian [Takatsuka, K. J. Chem. Phys. 2006, 124, 064111]. A manifestation of quantum fluctuation on a classical subsystem that directly contacts with a quantum subsystem is discussed. We also show that the Hamiltonian thus represented gives a theoretical foundation to examine the validity of the so-called semiclassical Ehrenfest theory (or mean-field theory) for electron quantum wavepacket dynamics, and indeed, it is pointed out that the electronic Hamiltonian to be used in this theory should be slightly modified.

  12. Origin of atmospheric aerosols at the Pierre Auger Observatory using studies of air mass trajectories in South America

    Science.gov (United States)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Antičić, T.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bardenet, R.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; BenZvi, S.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; De La Vega, G.; de Mello Junior, W. J. M.; de Mello Neto, J. R. T.; De Mitri, I.; de Souza, V.; de Vries, K. D.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; dos Anjos, J. C.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Foerster, N.; Fox, B. D.; Fracchiolla, C. E.; Fraenkel, E. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Gaior, R.; Gamarra, R. F.; Gambetta, S.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gemmeke, H.; Ghia, P. L.; Giammarchi, M.; Giller, M.; Gitto, J.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kadija, K.; Kambeitz, O.; Kampert, K. H.; Karhan, P.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Knapp, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agüera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marquez Falcon, H. R.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morales, B.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navarro, J. L.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nhung, P. T.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Nožka, L.; Oehlschläger, J.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Pontz, M.; Porcelli, A.; Preda, T.; Privitera, P.; Prouza, M.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rivera, H.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Martino, J.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Rouillé-d'Orfeuil, B.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Scuderi, M.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Spinka, H.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Straub, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Šuša, T.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Tapia, A.; Tartare, M.; Taşcău, O.; Thao, N. T.; Tiffenberg, J.; Timmermans, C.; Tkaczyk, W.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Tridapalli, D. B.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Wahlberg, H.; Wahrlich, P.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Westerhoff, S.; Whelan, B. J.; Widom, A.; Wieczorek, G.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Curci, G.

    2014-11-01

    The Pierre Auger Observatory is making significant contributions towards understanding the nature and origin of ultra-high energy cosmic rays. One of its main challenges is the monitoring of the atmosphere, both in terms of its state variables and its optical properties. The aim of this work is to analyse aerosol optical depth τa(z) values measured from 2004 to 2012 at the observatory, which is located in a remote and relatively unstudied area of Pampa Amarilla, Argentina. The aerosol optical depth is in average quite low - annual mean τa(3.5 km) ∼ 0.04 - and shows a seasonal trend with a winter minimum - τa(3.5 km) ∼ 0.03 -, and a summer maximum - τa(3.5 km) ∼ 0.06 -, and an unexpected increase from August to September - τa(3.5 km) ∼ 0.055. We computed backward trajectories for the years 2005 to 2012 to interpret the air mass origin. Winter nights with low aerosol concentrations show air masses originating from the Pacific Ocean. Average concentrations are affected by continental sources (wind-blown dust and urban pollution), whilst the peak observed in September and October could be linked to biomass burning in the northern part of Argentina or air pollution coming from surrounding urban areas.

  13. Origin of atmospheric aerosols at the Pierre Auger Observatory using studies of air mass trajectories in South America

    CERN Document Server

    Curci, Gabriele

    2014-01-01

    The Pierre Auger Observatory is making significant contributions towards understanding the nature and origin of ultra-high energy cosmic rays. One of its main challenges is the monitoring of the atmosphere, both in terms of its state variables and its optical properties. The aim of this work is to analyze aerosol optical depth $\\tau_{\\rm a}(z)$ values measured from 2004 to 2012 at the observatory, which is located in a remote and relatively unstudied area of the Pampa Amarilla, Argentina. The aerosol optical depth is in average quite low - annual mean $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.04$ - and shows a seasonal trend with a winter minimum - $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.03$ -, and a summer maximum - $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.06$ -, and an unexpected increase from August to September - $\\tau_{\\rm a}(3.5~{\\rm km})\\sim 0.055$). We computed backward trajectories for the years 2005 to 2012 to interpret the air mass origin. Winter nights with low aerosol concentrations show air masses originating from t...

  14. Social functioning trajectories of young first-episode psychosis patients with and without cannabis misuse: a 30-month follow-up study.

    Science.gov (United States)

    González-Blanch, César; Gleeson, John F; Koval, Peter; Cotton, Sue M; McGorry, Patrick D; Alvarez-Jimenez, Mario

    2015-01-01

    The aim of the study was to investigate trajectories of social functioning in young people with first-episode psychosis (FEP) with and without cannabis misuse using a secondary analysis of data from the Episode-II trial. Forty-two young people with FEP and comorbid cannabis use disorder were compared with 39 young people with FEP but without a cannabis use disorder. Social functioning was assessed every 6 months during a 30-month follow-up. Multilevel linear growth curve modeling was used to compare the social functioning trajectories over time for those with and without cannabis misuse. Cannabis misuse was not associated with social functioning at baseline assessment. Over a 30-month follow-up, FEP patients without cannabis disorder showed significant improvements in their social functioning, whereas patients with cannabis misuse at baseline displayed no such improvement. Patients with and without cannabis misuse differed significantly in their levels of social functioning after 24 months. Similar results were obtained after adjusting for potential confounders (i.e., age, gender, negative symptoms, premorbid functioning, DSM-IV diagnoses, baseline social functioning and other substance use). In the context of a specialized early intervention service, patients with cannabis misuse at baseline did not attain the improvements in social outcomes observed in their counterparts without cannabis misuse. There is a need to develop effective interventions to reduce cannabis misuse to ultimately improve social outcomes in young people with psychosis.

  15. A Big Five approach to self-regulation: personality traits and health trajectories in the Hawaii longitudinal study of personality and health.

    Science.gov (United States)

    Hampson, Sarah E; Edmonds, Grant W; Barckley, Maureen; Goldberg, Lewis R; Dubanoski, Joan P; Hillier, Teresa A

    2016-01-01

    Self-regulatory processes influencing health outcomes may have their origins in childhood personality traits. The Big Five approach to personality was used here to investigate the associations between childhood traits, trait-related regulatory processes and changes in health across middle age. Participants (N = 1176) were members of the Hawaii longitudinal study of personality and health. Teacher assessments of the participants' traits when they were in elementary school were related to trajectories of self-rated health measured on 6 occasions over 14 years in middle age. Five trajectories of self-rated health were identified by latent class growth analysis: Stable Excellent, Stable Very Good, Good, Decreasing and Poor. Childhood Conscientiousness was the only childhood trait to predict membership in the Decreasing class vs. the combined healthy classes (Stable Excellent, Stable Very Good and Good), even after controlling for adult Conscientiousness and the other adult Big Five traits. The Decreasing class had poorer objectively assessed clinical health measured on one occasion in middle age, was less well-educated, and had a history of more lifespan health-damaging behaviors compared to the combined healthy classes. These findings suggest that higher levels of childhood Conscientiousness (i.e. greater self-discipline and goal-directedness) may prevent subsequent health decline decades later through self-regulatory processes involving the acquisition of lifelong healthful behavior patterns and higher educational attainment.

  16. Social functioning trajectories of young first-episode psychosis patients with and without cannabis misuse: a 30-month follow-up study.

    Directory of Open Access Journals (Sweden)

    César González-Blanch

    Full Text Available The aim of the study was to investigate trajectories of social functioning in young people with first-episode psychosis (FEP with and without cannabis misuse using a secondary analysis of data from the Episode-II trial. Forty-two young people with FEP and comorbid cannabis use disorder were compared with 39 young people with FEP but without a cannabis use disorder. Social functioning was assessed every 6 months during a 30-month follow-up. Multilevel linear growth curve modeling was used to compare the social functioning trajectories over time for those with and without cannabis misuse. Cannabis misuse was not associated with social functioning at baseline assessment. Over a 30-month follow-up, FEP patients without cannabis disorder showed significant improvements in their social functioning, whereas patients with cannabis misuse at baseline displayed no such improvement. Patients with and without cannabis misuse differed significantly in their levels of social functioning after 24 months. Similar results were obtained after adjusting for potential confounders (i.e., age, gender, negative symptoms, premorbid functioning, DSM-IV diagnoses, baseline social functioning and other substance use. In the context of a specialized early intervention service, patients with cannabis misuse at baseline did not attain the improvements in social outcomes observed in their counterparts without cannabis misuse. There is a need to develop effective interventions to reduce cannabis misuse to ultimately improve social outcomes in young people with psychosis.

  17. Is the war really over? A 20-year longitudinal study on trajectories of suicidal ideation and posttraumatic stress symptoms following combat.

    Science.gov (United States)

    Snir, Avigal; Levi-Belz, Yossi; Solomon, Zahava

    2017-01-01

    Combat stress reaction (CSR) has widespread long-term consequences, including profound psychopathology in the form of posttraumatic stress disorder (PTSD). Studies have established the link between combat, PTSD, and suicidality. However, little is known about the temporal course of suicidal ideation (SI) in general, specifically among war veterans. We aimed to trace the trajectories of SI in the aftermath of war and to explore the role of CSR and PTSD in SI trajectories. Israeli veterans with CSR (n=164) and a matched control group (NCSR, n=111) were assessed, using self-report measures at three points over the course of 20 years. Veterans with CSR reported significantly higher levels of SI, compared to the NCSR group at all measurement points. Among veterans with CSR, SI increased 2 years after the war and then decreased 20 years following the war. This pattern was particularly characteristic of veterans with chronic PTSD. The results indicate that CSR is a strong predictor of subsequent PTSD and suicidality. These findings highlight the importance of prevention and treatment efforts for these traumatized veterans, who are at risk for suicide even 20 years after the end of the war.

  18. Bohmian mechanics, collapse models and the emergence of classicality

    Science.gov (United States)

    Toroš, Marko; Donadi, Sandro; Bassi, Angelo

    2016-09-01

    We discuss the emergence of classical trajectories in Bohmian mechanics, when a macroscopic object interacts with an external environment. We show that in such a case the conditional wave function of the system follows a dynamics which, under reasonable assumptions, corresponds to that of the Ghirardi-Rimini-Weber (GRW) collapse model. As a consequence, Bohmian trajectories evolve classically. Our analysis also shows how the GRW (istantaneous) collapse process can be derived by an underlying continuous interaction of a quantum system with an external agent, thus throwing a light on how collapses can emerge from a deeper level theory.

  19. Remarks on the completeness of trajectories of accelerated particles in Riemannian manifolds and plane waves

    CERN Document Server

    Candela, Anna Maria; Sánchez, Miguel

    2013-01-01

    Recently, classical results on completeness of trajectories of Hamiltonian systems obtained at the beginning of the seventies, have been revisited, improved and applied to Lorentzian Geometry. Our aim here is threefold: to give explicit proofs of some technicalities in the background of the specialists, to show that the introduced tools allow to obtain more results for the completeness of the trajectories, and to apply these results to the completeness of spacetimes that generalize classical plane and pp-waves.

  20. Bounds for Minkowski Billiard Trajectories in Convex Bodies

    CERN Document Server

    Artstein-Avidan, Shiri

    2011-01-01

    In this paper we use the Ekeland-Hofer-Zehnder symplectic capacity to provide several bounds and inequalities for the length of the shortest periodic billiard trajectory in a smooth convex body in ${\\mathbb R}^{n}$. Our results hold both for classical billiards, as well as for the more general case of Minkowski billiards.