2,422 research outputs found

    The creative writer: an examination of early childhood environment, psychopathology, and personality traits

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    The early childhood environment, the pathology, and the personality traits of non-eminent creative writers were compared to those of non-creative artists. The stated issues were examined using a thirty-item, forced choice questionaire. The results indicated that the non-creative writer group experienced more early childhood trauma than did the non-creative artist group. The findings are congruent with previous research and supports the position that early childhood environment plays a significant role in the development of creativity

    Reduction and reconstruction of stochastic differential equations via symmetries

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    An algorithmic method to exploit a general class of infinitesimal symmetries for reducing stochastic differential equations is presented and a natural definition of reconstruction, inspired by the classical reconstruction by quadratures, is proposed. As a side result the well-known solution formula for linear one-dimensional stochastic differential equations is obtained within this symmetry approach. The complete procedure is applied to several examples with both theoretical and applied relevance

    Numerical modeling of thermal refraction in liquids in the transient regime

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    We present the results of modeling of nanosecond pulse propagation in optically absorbing liquid media. Acoustic and electromagnetic wave equations must be solved simultaneously to model refractive index changes due to thermal expansion and/or electrostriction, which are highly transient phenomena on a nanosecond time scale. Although we consider situations with cylindrical symmetry and where the paraxial approximation is valid, this is still a computation-intensive problem, as beam propagation through optically thick media must be modeled. We compare the full solution of the acoustic wave equation with the approximation of instantaneous expansion (steady-state solution) and hence determine the regimes of validity of this approximation. We also find that the refractive index change obtained from the photo-acoustic equation overshoots its steady-state value once the ratio between the pulsewidth and the acoustic transit time exceeds a factor of unity

    Life and Death at the Edge of a Windy Cliff

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    The survival probability of a particle diffusing in the two dimensional domain x>0x>0 near a ``windy cliff'' at x=0x=0 is investigated. The particle dies upon reaching the edge of the cliff. In addition to diffusion, the particle is influenced by a steady ``wind shear'' with velocity v(x,y)=vsign(y)x^\vec v(x,y)=v\,{\rm sign}(y)\,\hat x, \ie, no average bias either toward or away from the cliff. For this semi-infinite system, the particle survival probability decays with time as t1/4t^{-1/4}, compared to t1/2t^{-1/2} in the absence of wind. Scaling descriptions are developed to elucidate this behavior, as well as the survival probability within a semi-infinite strip of finite width y<w|y|<w with particle absorption at x=0x=0. The behavior in the strip geometry can be described in terms of Taylor diffusion, an approach which accounts for the crossover to the t1/4t^{-1/4} decay when the width of the strip diverges. Supporting numerical simulations of our analytical results are presented.Comment: 13 pages, plain TeX, 5 figures available upon request to SR (submitted to J. Stat. Phys.

    Knowledge and attitude towards sexually transmitted infections among female students living in hostels in a university community of the south-south region of Nigeria

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    Introduction: A cross sectional study was conducted in the female students’ hostel of the University of Calabar to determine their knowledge and attitude towards sexually transmitted infections (STI).Methodology: A structured questionnaire was administered to those who consented to the study. Information obtained were age, year of study, knowledge of sexually transmitted infections.Results: Most subjects were in the age category of 21-25years (56.2%) and predominantly of the Igbo tribe 34%. Over 90% of the subjects had heard of STIs. Vaginal itching (70.2%) and discharge (65.7%) were the commonest symptoms reported. Despite the level of knowledge, some students still patronize Chemist 4.8% and self-injection administration 4.8%.Conclusion: The awareness of STI is high but the understanding of symptomatology is poor.Keywords: Sexually transmitted infections, Female hostel, Tertiary Institution

    Psychopathic traits influence amygdala-anterior cingulate cortex connectivity during facial emotion processing

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    There is accumulating evidence that youths with antisocial behavior or psychopathic traits show deficits in facial emotion recognition, but little is known about the neural mechanisms underlying these impairments. A number of neuroimaging studies have investigated brain activity during facial emotion processing in youths with Conduct Disorder (CD) and adults with psychopathy, but few of these studies tested for group differences in effective connectivity – i.e., changes in connectivity during emotion processing. Using functional magnetic resonance imaging and psycho-physiological interaction methods, we investigated the impact of CD and psychopathic traits on amygdala activity and effective connectivity in 46 male youths with CD and 25 typically-developing controls when processing emotional faces. All participants were aged 16-21 years. Relative to controls, youths with CD showed reduced amygdala activity when processing angry or sad faces relative to neutral faces, but the groups did not significantly differ in amygdala-related effective connectivity. In contrast, psychopathic traits were negatively correlated with amygdala-ventral anterior cingulate cortex connectivity for angry versus neutral faces, but were unrelated to amygdala responses to angry or sad faces. These findings suggest that CD and psychopathic traits have differential effects on amygdala activation and functional interactions between limbic regions during facial emotion processing

    Doppler Effect of Nonlinear Waves and Superspirals in Oscillatory Media

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    Nonlinear waves emitted from a moving source are studied. A meandering spiral in a reaction-diffusion medium provides an example, where waves originate from a source exhibiting a back-and-forth movement in radial direction. The periodic motion of the source induces a Doppler effect that causes a modulation in wavelength and amplitude of the waves (``superspiral''). Using the complex Ginzburg-Landau equation, we show that waves subject to a convective Eckhaus instability can exhibit monotonous growth or decay as well as saturation of these modulations away from the source depending on the perturbation frequency. Our findings allow a consistent interpretation of recent experimental observations concerning superspirals and their decay to spatio-temporal chaos.Comment: 4 pages, 4 figure

    Interaction of Vortices in Complex Vector Field and Stability of a ``Vortex Molecule''

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    We consider interaction of vortices in the vector complex Ginzburg--Landau equation (CVGLE). In the limit of small field coupling, it is found analytically that the interaction between well-separated defects in two different fields is long-range, in contrast to interaction between defects in the same field which falls off exponentially. In a certain region of parameters of CVGLE, we find stable rotating bound states of two defects -- a ``vortex molecule".Comment: 4 pages, 5 figures, submitted to Phys. Rev. Let

    Spatially Resolved Mapping of Local Polarization Dynamics in an Ergodic Phase of Ferroelectric Relaxor

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    Spatial variability of polarization relaxation kinetics in relaxor ferroelectric 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3 is studied using time-resolved Piezoresponse Force Microscopy. Local relaxation attributed to the reorientation of polar nanoregions is shown to follow stretched exponential dependence, exp(-(t/tau)^beta), with beta~~0.4, much larger than the macroscopic value determined from dielectric spectra (beta~~0.09). The spatial inhomogeneity of relaxation time distributions with the presence of 100-200 nm "fast" and "slow" regions is observed. The results are analyzed to map the Vogel-Fulcher temperatures on the nanoscale.Comment: 23 pages, 4 figures, supplementary materials attached; to be submitted to Phys. Rev. Let
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