190 research outputs found

    Psychometric properties of an instrument of reasons for admission to university careers in health sciences

    Full text link
    [EN] The purpose of this research was to analyze the validity and reliability of the instrument called “Reasons for Admission to Careers in Health Sciences (MICCS) (acronym in Spanish)”. The study was developed with a non-probabilistic and incidental sample of 194 students from a higher education institution in the state of Jalisco, Mexico. After reviewing the contenty validity by expert judges, an exploratory factor analysis was executed (principal components method and Varimax rotation). Seven dimensions were defined under the critery of theoretical position and inflection of the curve of sedimentation. The indexes of KMO (0.788) and Bartlett (X (990) = 2916.36, p=0.000) reported an appropriate model. Items with theoretical inconsistencies and saturations under of 0.4 were eliminated. Its internal consistency was acceptable (α=0.834). The final version of the instrument consisted of 30 items and six independent factors, showing satisfactory psychometric properties. Finally were contrasted the reasons for entering careers in medicine, nursing, nutrition and dentistry to the variables of sex, vocational orientation and type of school. It is proposed to extend the investigation of reasons for entering science careers health by using the scale in public and private institutions of higher education; In addition, it is recommended to analyze the relationship of the reasons for admission and psychosocial variables such as academic performance, lag, desertion, satisfaction and academic stress.[ES] El presente trabajo de investigación tuvo como propósito analizar la validez y confiabilidad del instrumento denominado “Motivos de Ingreso a las Carreras de Ciencias de la Salud (MICCS)”. El estudio se desarrolló con una muestra no probabilística e incidental de 194 alumnos de una institución de educación superior del estado de Jalisco, México. Después de abordar la validez de contenido mediante jueces expertos, se ejecutó un análisis factorial exploratorio (método de componentes principales y rotación Varimax) donde se definieron siete dimensiones bajo el criterio de postura teórica e inflexión de la curva de sedimentación. Los índices de KMO (0.788) y Bartlett (X(990)=2916.36; p=0.000) señalaron un modelo apropiado y sin esfericidad. Los ítems con inconsistencias teóricas y saturaciones menores a 0.4 fueron eliminados. Su consistencia interna general fue aceptable (α=0.834). La versión final del instrumento quedó conformada de 30 reactivos y seis factores independientes, mostrando propiedades psicométricas satisfactorias. Por último, se contrastaron los motivos de ingreso de las carreras de medicina, enfermería, nutrición y odontología con las variables de sexo, orientación vocacional y tipo de bachillerato. Se propone ampliar la línea de investigación de los motivos de ingreso a carreras de ciencias de la salud mediante el uso de la escala en instituciones de educación superior públicas y privadas; además, se recomienda abordar la posible relación de los motivos de ingreso con variables escolares y psicosociales como el rendimiento académico, el atraso educativo, la deserción, la satisfacción y el estrés académico.Caldera Montes, JF.; Reynoso González, O.; Sughey González Torres, Y.; Zamora Betancourt, M. (2018). Propiedades psicométricas de un instrumento de motivos de ingreso a carreras universitarias de ciencias de la salud. 33-50. doi:10.4995/redu.2018.6052SWORD335

    Hydrophobic and ionic-interactions in bulk and confined water with implications for collapse and folding of proteins

    Full text link
    Water and water-mediated interactions determine thermodynamic and kinetics of protein folding, protein aggregation and self-assembly in confined spaces. To obtain insights into the role of water in the context of folding problems, we describe computer simulations of a few related model systems. The dynamics of collapse of eicosane shows that upon expulsion of water the linear hydrocarbon chain adopts an ordered helical hairpin structure with 1.5 turns. The structure of dimer of eicosane molecules has two well ordered helical hairpins that are stacked perpendicular to each other. As a prelude to studying folding in confined spaces we used simulations to understand changes in hydrophobic and ionic interactions in nano droplets. Solvation of hydrophobic and charged species change drastically in nano water droplets. Hydrophobic species are localized at the boundary. The tendency of ions to be at the boundary where water density is low increases as the charge density decreases. Interaction between hydrophobic, polar, and charged residue are also profoundly altered in confined spaces. Using the results of computer simulations and accounting for loss of chain entropy upon confinement we argue and then demonstrate, using simulations in explicit water, that ordered states of generic amphiphilic peptide sequences should be stabilized in cylindrical nanopores

    Knowledge-based energy functions for computational studies of proteins

    Full text link
    This chapter discusses theoretical framework and methods for developing knowledge-based potential functions essential for protein structure prediction, protein-protein interaction, and protein sequence design. We discuss in some details about the Miyazawa-Jernigan contact statistical potential, distance-dependent statistical potentials, as well as geometric statistical potentials. We also describe a geometric model for developing both linear and non-linear potential functions by optimization. Applications of knowledge-based potential functions in protein-decoy discrimination, in protein-protein interactions, and in protein design are then described. Several issues of knowledge-based potential functions are finally discussed.Comment: 57 pages, 6 figures. To be published in a book by Springe

    Energy and system size dependence of \phi meson production in Cu+Cu and Au+Au collisions

    Get PDF
    We study the beam-energy and system-size dependence of \phi meson production (using the hadronic decay mode \phi -- K+K-) by comparing the new results from Cu+Cu collisions and previously reported Au+Au collisions at \sqrt{s_NN} = 62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented are from mid-rapidity (|y|<0.5) for 0.4 < pT < 5 GeV/c. At a given beam energy, the transverse momentum distributions for \phi mesons are observed to be similar in yield and shape for Cu+Cu and Au+Au colliding systems with similar average numbers of participating nucleons. The \phi meson yields in nucleus-nucleus collisions, normalised by the average number of participating nucleons, are found to be enhanced relative to those from p+p collisions with a different trend compared to strange baryons. The enhancement for \phi mesons is observed to be higher at \sqrt{s_NN} = 200 GeV compared to 62.4 GeV. These observations for the produced \phi(s\bar{s}) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus-nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.Comment: 20 pages and 5 figure

    Measurement of the parity-violating longitudinal single-spin asymmetry for W±W^{\pm} boson production in polarized proton-proton collisions at s=500\sqrt{s} = 500 GeV

    Get PDF
    We report the first measurement of the parity violating single-spin asymmetries for midrapidity decay positrons and electrons from W+W^{+} and WW^{-} boson production in longitudinally polarized proton-proton collisions at s=500\sqrt{s}=500 GeV by the STAR experiment at RHIC. The measured asymmetries, ALW+=0.27±0.10  (stat.)±0.02  (syst.)±0.03  (norm.)A^{W^+}_{L}=-0.27\pm 0.10\;({\rm stat.})\pm 0.02\;({\rm syst.}) \pm 0.03\;({\rm norm.}) and ALW=0.14±0.19  (stat.)±0.02  (syst.)±0.01  (norm.)A^{W^-}_{L}=0.14\pm 0.19\;({\rm stat.})\pm 0.02 \;({\rm syst.})\pm 0.01\;({\rm norm.}), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized DIS measurements.Comment: 6 pages, 4 figures, submitted to Physics Review Letter

    Measurement of the Bottom contribution to non-photonic electron production in p+pp+p collisions at s\sqrt{s} =200 GeV

    Get PDF
    The contribution of BB meson decays to non-photonic electrons, which are mainly produced by the semi-leptonic decays of heavy flavor mesons, in p+pp+p collisions at s=\sqrt{s} = 200 GeV has been measured using azimuthal correlations between non-photonic electrons and hadrons. The extracted BB decay contribution is approximately 50% at a transverse momentum of pT5p_{T} \geq 5 GeV/cc. These measurements constrain the nuclear modification factor for electrons from BB and DD meson decays. The result indicates that BB meson production in heavy ion collisions is also suppressed at high pTp_{T}.Comment: 6 pages, 4 figures, accepted by PR

    Longitudinal scaling property of the charge balance function in Au + Au collisions at 200 GeV

    Get PDF
    We present measurements of the charge balance function, from the charged particles, for diverse pseudorapidity and transverse momentum ranges in Au + Au collisions at 200 GeV using the STAR detector at RHIC. We observe that the balance function is boost-invariant within the pseudorapidity coverage [-1.3, 1.3]. The balance function properly scaled by the width of the observed pseudorapidity window does not depend on the position or size of the pseudorapidity window. This scaling property also holds for particles in different transverse momentum ranges. In addition, we find that the width of the balance function decreases monotonically with increasing transverse momentum for all centrality classes.Comment: 6 pages, 3 figure

    System size dependence of associated yields in hadron-triggered jets

    Get PDF
    We present results on the system size dependence of high transverse momentum di-hadron correlations at sNN\sqrt{s_{NN}} = 200 GeV as measured by STAR at RHIC. Measurements in d+Au, Cu+Cu and Au+Au collisions reveal similar jet-like correlation yields at small angular separation (Δϕ0\Delta\phi\sim0, Δη0\Delta\eta\sim0) for all systems and centralities. Previous measurements have shown that the away-side yield is suppressed in heavy-ion collisions. We present measurements of the away-side suppression as a function of transverse momentum and centrality in Cu+Cu and Au+Au collisions. The suppression is found to be similar in Cu+Cu and Au+Au collisions at a similar number of participants. The results are compared to theoretical calculations based on the parton quenching model and the modified fragmentation model. The observed differences between data and theory indicate that the correlated yields presented here will provide important constraints on medium density profile and energy loss model parameters.Comment: 12 pages, 5 figure

    Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented
    corecore