13,749 research outputs found

    Role of Cerebellar Interpositus Nucleus in the Genesis and Control of Reflex and Conditioned Eyelid Responses

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    The role of cerebellar circuits in the acquisition of new motor abilities is still a matter of intensive debate. To establish the contribution of posterior interpositus nucleus (PIN) to the performance and/or acquisition of reflex and classically conditioned responses (CRs) of the eyelid, the effects of microstimulation and/or pharmacological inhibition by muscimol of the nucleus were investigated in conscious cats. Microstimulation of the PIN in naive animals evoked ramp-like eyelid responses with a wavy appearance, without producing any noticeable plastic functional change in the cerebellar and brainstem circuits involved. Muscimol microinjections decreased the amplitude of reflex eyeblinks evoked by air puffs, both when presented alone or when paired with a tone as conditioned stimulus (CS). In half-conditioned animals, muscimol injections also decreased the amplitude and damped the typical wavy profile of CRs, whereas microstimulation of the same sites increased both parameters. However, neither muscimol injections nor microstimulation modified the expected percentage of CRs, suggesting a major role of the PIN in the performance of eyelid responses rather than in the learning process. Moreover, the simultaneous presentation of CS and microstimulation in well trained animals evoked CRs similar in amplitude to the added value of those evoked by the two stimuli presented separately. In contrast, muscimol-injected animals developed CRs to paired CS and microstimulation presentations, larger than those evoked by the two stimuli when presented alone. It is concluded that the PIN contributes to the enhancement of both reflex and conditioned eyelid responses and to the damping of resonant properties of neuromuscular elements controlling eyelid kinematics

    On the dbar/ubar Asymmetry and Parton Distributions

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    We discuss the impact of different measurements of the dbar/ubar asymmetry in the extraction of parameterizations of parton distribution functions.Comment: Contributed paper to LP01, 13 pages, 4 figure

    Nuclear response functions in homogeneous matter with finite range effective interactions

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    The question of nuclear response functions in a homogeneous medium is examined. A general method for calculating response functions in the random phase approximation (RPA) with exchange is presented. The method is applicable for finite-range nuclear interactions. Examples are shown in the case of symmetric nuclear matter described by a Gogny interaction. It is found that the convergence of the results with respect to the multipole truncation is quite fast. Various approximation schemes such as the Landau approximation, or the Landau approximation for the exchange terms only, are discussed in comparison with the exact results.Comment: 9 pages, 9 figure

    Constructions of the soluble potentials for the non-relativistic quantum system by means of the Heun functions

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    The Schr\"{o}dinger equation ψ"(x)+κ2ψ(x)=0\psi"(x)+\kappa^2 \psi(x)=0 where κ2=k2V(x)\kappa^2=k^2-V(x) is rewritten as a more popular form of a second order differential equation through taking a similarity transformation ψ(z)=ϕ(z)u(z)\psi(z)=\phi(z)u(z) with z=z(x)z=z(x). The Schr\"{o}dinger invariant IS(x)I_{S}(x) can be calculated directly by the Schwarzian derivative {z,x}\{z, x\} and the invariant I(z)I(z) of the differential equation uzz+f(z)uz+g(z)u=0u_{zz}+f(z)u_{z}+g(z)u=0. We find an important relation for moving particle as 2=IS(x)\nabla^2=-I_{S}(x) and thus explain the reason why the Schr\"{o}dinger invariant IS(x)I_{S}(x) keeps constant. As an illustration, we take the typical Heun differential equation as an object to construct a class of soluble potentials and generalize the previous results through choosing different ρ=z(x)\rho=z'(x) as before. We get a more general solution z(x)z(x) through integrating (z)2=α1z2+β1z+γ1(z')^2=\alpha_{1}z^2+\beta_{1}z+\gamma_{1} directly and it includes all possibilities for those parameters. Some particular cases are discussed in detail.Comment: 11 page

    Gender differences in mental health during the economic crisis

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    Background: Economic crises have a negative effect on mental health. Little evidence has been published on the impact of economic downturns on male and female. The aim of the study was to analyze gender differences in specific mental disorders in primary care during the current economic recession in Spain. Method: A total of 7, 914 patients in 2006 and 5, 876 patients in 2010 were recruited to collect sociodemographic data and the Primary Care Evaluation of Mental Disorders. Results: Between 2006 and 2010 the prevalence of Major Depressive Disorder increased 155.7% in men and 104.9% in women; Generalized Anxiety Disorder increased 98.3% in men and 71.3% in women; and Multisomatoform Disorder increased 100.05% in men and 37% in women. The effect of the Employment confounder was significant across all comparisons: Major Depressive Disorder Generalized Odds Ratio=2.557 for Men (p<.001), 2.046 for Women (p=.002); Generalized Anxiety Disorder Generalized Odds Ratio= 2.153 (p<.001) for Men, 1.546 for Women (p<.001); and for Non-specific Multisomatoform Disorder Generalized Odds Ratio=1.680 for Men (p<.001) and 1.301 for women (p=.014). Conclusion: Overall prevalence of mental disorders increased significantly between 2006 and 2010, especially in males, who are more sensitive to the effect of the current economic recession than women. Antecedentes: el impacto de las crisis económicas sobre la salud mental está bien documentado, pero hay poca evidencia sobre el efecto diferencial que pueda tener entre hombres y mujeres. El objetivo fue analizar las diferencias de género en la prevalencia de trastornos mentales en atención primaria durante la recesión económica en España. Método: 7.914 pacientes en 2006-2007 y 5.876 en 2010-2011 fueron encuestados para recoger datos sociodemográficos y completar la entrevista Primary Care Evaluation of Mental Disorders. Resultados: entre 2006 y 2010 la prevalencia del Trastorno Depresivo Mayor incrementó 155, 7% en hombres y un 104, 9% en mujeres; el Trastorno de Ansiedad Generalizada aumentó 98, 3% en hombres y 71, 3% en mujeres; el Trastorno Multisomatomorfo incrementó 100, 05% en hombres y 37% en mujeres. El desempleo fue significativo en todos los análisis: Trastorno Depresivo Odds Ratio Generalizados= 2.557 en hombres (p<.001), 2.046 en mujeres (p= .002); Trastorno de Ansiedad Generalizada Odds Ratio Generalizados= 2.153 (p<.001) en hombres, 1.546 en mujeres (p<.001); Trastorno Multisomatoformo indiferenciado Odds Ratio Generalizados= 1.680 en hombres (p<.001) y 1.301 en mujeres (p= .014). Conclusiones: la prevalencia de los trastornos mentales se incrementó entre 2006 y 2010 en ambos sexos, pero especialmente en hombres, quienes son más sensibles a los efectos de la crisis económica

    Intrinsic Moment of Inertia of Membranes as bounds for the mass gap of Yang-Mills Theories

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    We obtain the precise condition on the potentials of Yang-Mills theories in 0+1 dimensions and D0 brane quantum mechanics ensuring the discretness of the spectrum. It is given in terms of a moment of inertia of the membrane. From it we obtain a bound for the mass gap of any D+1 Yang-Mills theory in the slow-mode regime. In particular we analyze the physical case D=3. The quantum mechanical behavior of the theories, concerning its spectrum, is determined by harmonic oscillators with frequencies given by the inertial tensor of the membrane. We find a class of quantum mechanic potential polynomials of any degree, with classical instabilities that at quantum level have purely discrete spectrum.Comment: 12pages, Latex, minor changes, more explanatory comment

    The VVV Survey RR Lyrae Population in the Galactic Center Region

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    Indexación: Scopus.We gratefully acknowledge the use of data from the ESO Public Survey program ID 179.B-2002 taken with the VISTA telescope, and data products from the Cambridge Astronomical Survey Unit (CASU). Support for the authors is provided by the BASAL Center for Astrophysics and Associated Technologies (CATA) through grant PFB-06, and the Ministry for the Economy, Development, and Tourism, Programa Iniciativa Cientifica Milenio through grant IC120009, awarded to the Millennium Institute of Astrophysics (MAS). D.M. and M.Z. acknowledge support from FONDECYT Regular grants No. 1170121, and 1150345, respectively. P.H. acknowledges financial support from FONDECYT regular grant 1170305. F.G. acknowledge support from CONICYT-PCHA Doctorado Nacional 2017-21171485 and Proyecto Fondecyt Regular 1150345. J.A.-G. acknowledges support by FONDECYT Iniciacion 11150916. D.M. is also grateful for the hospitality of the Vatican Observatory. This research made use of Astropy, a community-developed core Python package for astronomy; Scikit-learn, NumPy, and matplotlib, a Python library for publication-quality graphics; and Aladin Sky Atlas, developed at CDS, Strasbourg Observatory, France, and TOPCAT.Deep near-IR images from the VISTA Variables in the V a L ctea (VVV) Survey were used to search for RR Lyrae stars within 100 arcmin from the Galactic Center. A large sample of 960 RR Lyrae of type ab (RRab) stars were discovered. A catalog is presented featuring the positions, magnitudes, colors, periods, and amplitudes for the sample, in addition to estimated reddenings, distances, and metallicities, and measured individual relative proper motions. We use the reddening-corrected Wesenheit magnitudes, defined as WKs Ks 0.428 J Ks = - ( - ), in order to isolate bona fide RRL belonging to the Galaxy Center, finding that 30 RRab are foreground/background objects. We measure a range of extinctions from AKs 0.19 = to 1.75 mag for the RRab in this region, finding that large extinction is the main cause of the sample incompleteness. The mean period is P =0.5446±0.0025 days, yielding a mean metallicity of [Fe/H] =-1.30±0.01 (ς = 0.33) dex for the RRab sample in the Galactic Center region. The median distance for the sample is D =8.05±0.02 kpc. We measure the RRab surface density using the less reddened region sampled here, finding a density of 1000 RRab/sq deg at a projected Galactocentric distance RG =1.6 deg. Under simple assumptions, this implies a large total mass (M>109Me) for the old and metal-poor population contained inside RG. We also measure accurate relative proper motions, from which we derive tangential velocity dispersions of ςVl =125.0 and ςVb =124.1 km s-1 along the Galactic longitude and latitude coordinates, respectively. The fact that these quantities are similar indicate that the bulk rotation of the RRab population is negligible, and implies that this population is supported by velocity dispersion. In summary, there are two main conclusions of this study. First, the population as a whole is no different from the outer bulge RRab, predominantly a metal-poor component that is shifted with respect to the Oosterhoff type I population defined by the globular clusters in the halo. Second, the RRab sample, as representative of the old and metal-poor stellar population in the region, has high velocity dispersions and zero rotation, suggesting a formation via dissipational collapse. ©2018. The American Astronomical Society. All rights reserved.https://iopscience.iop.org/article/10.3847/1538-4357/aacf9
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