631 research outputs found

    Validez y confiabilidad de la escala del Center for Epidemiologic Studies-Depression en estudiantes adolescentes de Colombia

    Get PDF
    Introduction. Major depressive disorder is the second major cause of adolescent psychological incapacitation in Latin-America. However, scales for detecting these disorders have not been validated for screening adolescents in Colombia.Objective. The validity and reliability of a Spanish translation of the Center for Epidemiologic Studies (CES-D)-Depression scale was assessed in adolescent students.Materials and methods. A validation study for a diagnostic scale was performed with a sample of 390 adolescent students from Bucaramanga, Santander Province, in northwestern Colombia. The students were evaluated by two methods: (a) the CPS-depression scale and (b) a semi-structured clinical interview. Three to 28 days after the interview, the scale was re-applied. Criterion validity, internal consistency and test-retest reliability was analyzed.Results. The mean age was 14.8±1.2 years old. The prevalence of major depressive disorder was 11.5%. Cronbach’s alpha was 0.85. The area under the curve produced by the receiver operating characteristic curve was 0.82, and the cut point of ≥23 showed a sensitivity of 73.3%; specificity, 73.6%; positive predictive value, 26.6%, and negative predictive value, 95.5%. Lin´s coefficient of concordance was 0.75. Conclusions. The validity and reliability of the Spanish translation of the CES-D scale were similar to those reported in the international literature although with a higher cut point.Introducción. El trastorno depresivo mayor es la segunda causa productora de discapacidad en Latinoamérica. No hay escalas validadas en Colombia para adolescentes.Objetivo. Evaluar la validez y la confiabilidad de la escala del Centro de Estudios Epidemiológicos para la Depresión en adolescentes colombianos en edad escolar.Materiales y métodos. Se llevó a cabo un estudio de validación de la escala con una muestra de adolescentes en edad escolar de Bucaramanga. Se evaluaron con la escala para depresión y la entrevista clínica estructurada. La escala fue aplicada nuevamente 3 a 28 días después. Se determinaron la validez de criterio, la consistencia interna y la reproducibilidad prueba reprueba.Resultados. Se evaluaron 390 adolescentes con edad promedio de 14,8±1,22 años. La prevalencia de trastorno depresivo mayor fue de 11,5%. El índice de consistencia, o alfa de Cronbach, fue de 0,85. El área bajo la curva según las características receptor operador fue de 0,82 y el punto de corte mayor o igual a 23 mostró una sensibilidad de 73,3%. Se encontró: especificidad de 73,6%, valor diagnóstico positivo de 26,6% y valor diagnóstico negativo de 95,5%. El coeficiente de concordancia de Lin fue de 0,75.Conclusión. La validez y la confiabilidad de la versión en español de la escala en adolescentes en edad escolar del Centro de Estudios Epidemiológicos para la Depresión, fueron similares a las informadas anteriormente, aunque cambió el punto de corte

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

    Get PDF
    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    Decoupling Contributions from Canopy Structure and Leaf Optics is Critical for Remote Sensing Leaf Biochemistry (Reply to Townsend, et al.)

    Get PDF
    Townsend et al. (1) agree that we explained that the apparent relationship (2) between foliar nitrogen (%N) and near-infrared (NIR) canopy reflectance was largely attributable to structure (which is in turn caused by variation in fraction of broadleaf canopy). Our conclusion that the observed correlation with %N was spurious (i.e., lacking a causal basis) is, thus, clearly justified: we demonstrated that structure explained the great majority of observed correlation, where the structural influence was derived precisely via reconciling the observed correlation with radiative-transfer theory. What this also suggests is that such correlations, although observed, do not uniquely provide information on canopy biochemical constituents

    Finishing the euchromatic sequence of the human genome

    Get PDF
    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Measurement of the B0^{0}s_{s} → μ+^{+} μ^{-} decay properties and search for the B0^{0} → μ+^{+}μ^{-} decay in proton-proton collisions at √s = 13 TeV

    Get PDF

    Search for top squarks in the four-body decay mode with single lepton final states in proton-proton collisions at s \sqrt{s} = 13 TeV

    Get PDF
    A search for the pair production of the lightest supersymmetric partner of the top quark, the top squark (t∼1), is presented. The search targets the four-body decay of the t∼1, which is preferred when the mass difference between the top squark and the lightest supersymmetric particle is smaller than the mass of the W boson. This decay mode consists of a bottom quark, two other fermions, and the lightest neutralino (χ∼01), which is assumed to be the lightest supersymmetric particle. The data correspond to an integrated luminosity of 138 fb−1 of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC. Events are selected using the presence of a high-momentum jet, an electron or muon with low transverse momentum, and a significant missing transverse momentum. The signal is selected based on a multivariate approach that is optimized for the difference between m(t∼1) and m(χ∼01). The contribution from leading background processes is estimated from data. No significant excess is observed above the expectation from standard model processes. The results of this search exclude top squarks at 95% confidence level for masses up to 480 and 700 GeV for m(t∼1) − m(χ∼01) = 10 and 80 GeV, respectively

    Measurement of the cross section of top quark-antiquark pair production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

    Get PDF
    The production of a top quark-antiquark pair in association with a W boson (ttˉW)(t\bar{t}W) is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The analyzed data was recorded by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb1^{−1}. Events with two or three leptons (electrons and muons) and additional jets are selected. In events with two leptons, a multiclass neural network is used to distinguish between the signal and background processes. Events with three leptons are categorized based on the number of jets and of jets originating from b quark hadronization, and the lepton charges. The inclusive (ttˉW)(t\bar{t}W) production cross section in the full phase space is measured to be 868 ± 40(stat) ± 51(syst) fb. The (ttˉW)+(t\bar{t}W)+ and (ttˉW)(t\bar{t}W)− cross sections are also measured as 553 ± 30(stat) ± 30(syst) and 343 ± 26(stat) ± 25(syst) fb, respectively, and the corresponding ratio of the two cross sections is found to be 1.61±0.15(stat)0.05+0.07^{+0.07}_{−0.05}(syst). The measured cross sections are larger than but consistent with the standard model predictions within two standard deviations, and represent the most precise measurement of these cross sections to date

    Measurement of the Dependence of the Hadron Production Fraction Ratios fs/fuf_s / f_u and fd/fuf_d / f_u on BB Meson Kinematic Variables in Proton-Proton Collisions at s=13TeV\sqrt{s} = 13 TeV

    Get PDF
    The dependence of the ratio between the Bs0B^0_s and B+B^+ hadron production fractions, fs/fuf_s/f_u, on the transverse momentum (pT)(p_T) and rapidity of the BB mesons is studied using the decay channels Bs0J/ψϕB^0_s→J/ψϕ and B+J/ψK+B^+→J/ψK^+. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 61.6  fb161.6  fb^{−1}. The fs/fuf_s/f_u ratio is observed to depend on the BB pTp_T and to be consistent with becoming asymptotically constant at large pTp_T. No rapidity dependence is observed. The ratio of the B0B^0 to B+B^+ meson production fractions, fd/fuf_d/f_u, is also measured, for the first time in proton-proton collisions, using the B0J/ψK0B^0→J/ψK^{*0} decay channel. The result is found to be within 1 standard deviation of unity and independent of pTpT and rapidity, as expected from isospin invariance
    corecore