References data on the growth and population parameters of brown trout in siliceous rivers of Galicia (NW Spain)

Brown trout is an important angling species worldwide, and its morphology, population structure and genetics can be highly variable from one location to another. In this study, we provide data for the establishment of reference range values for several population and growth parameters of brown trout in the Cantabrian-Atlantic siliceous rivers of Galicia (NW Spain). Additionally, this study tests the hypothesis that the population and growth parameters differ among sections of rivers with different exploitation statuses (unexploited, exploited-regulated and exploited-open sections). Our study revealed that such population parameters as biomass and production were higher in unexploited sections, but the differences in growth among the sections with different angling regulations were not consistent. The findings of this study are discussed in light of the present knowledge on the status of trout fisheries, as it is essential for the development of management plans. Additional studies are needed to clarify whether the differences in growth can be correlated to the angling regulations.La trucha común es una especie muy apreciada por los pescadores deportivos en todo el mundo, y su morfología, estructura poblacional y características genéticas pueden variar considerablemente entre áreas geográficas próximas. En este estudio proporcionamos datos para el establecimiento de categorías de referencia de varios parámetros poblacionales y de crecimiento de la trucha común en ríos silíceos Cantábrico-Atlánticos de Galicia (NO España). Además, con la realización de este estudio se pretende verificar la hipótesis de que los parámetros poblacionales y el crecimiento pueden variar entre tramos de ríos con diferente tipo de regulación de pesca deportiva (tramos vedados o inexplotados, tramos de pesca acotados y tramos de pesca libre). Así, nuestro estudio reveló que algunos parámetros poblacionales como la biomasa y la producción fueron más elevados en los tramos vedados, pero las diferencias en el crecimiento entre tramos con diferente regulación de pesca deportiva no fueron consistentes. Los resultados de este trabajo se discuten teniendo en cuenta el conocimiento actual sobre el estado de las poblaciones de trucha común, pues son esenciales para el desarrollo de planes de gestión. No obstante, se requieren de más estudios para aclarar si las diferencias en crecimiento se pueden relacionar con el tipo de regulación de pesca deportiva

Text Anxiety in Elementary School Students: Differences by School Year and Gender

A pesar de su alta prevalencia en el ámbito académico, pocos estudios han analizado la ansiedad ante los exámenes en la etapa de Educación Primaria. El presente estudio tuvo dos objetivos: determinar cuáles eran las asignaturas que generaban una mayor ansiedad ante los exámenes; y analizar las diferencias en los niveles de ansiedad ante los exámenes en función del curso académico y del género. Se utilizó una muestra de 250 estudiantes (Medad = 9.66; DTedad = 1.18), de la cual el 54.4% eran mujeres y el 45.6%, varones. El estudio de las asignaturas con mayor carga ansiógena ligada a los exámenes se determinó mediante la prueba χ2 de Pearson. Las diferencias de género y curso se analizaron mediante un ANOVA de dos factores. Los resultados obtenidos indican que las materias que generan más ansiedad ante los exámenes son las vinculadas al ámbito científico. Asimismo, se encontraron niveles de ansiedad significativamente más elevados en el estudiantado de los cursos superiores, no existiendo diferencias en cuanto al género. La interacción entre el curso y el género no resultó estadísticamente significativa. Se plantean algunas medidas psicoeducativas tendentes a reducir o eliminar la ansiedad ante los exámenes en Educación Primaria.Despite its high prevalence in the academic field, few studies have analyzed text anxiety in the stage of elementary school. The present study had two objectives: firstly, we have sought to determine the subjects that generated greater test anxiety; secondly, we have analyzed differences in test anxiety by school year and gender. A sample of two hundred and fifty students took part in the study (Mage = 9.66; SDage = 1.18), of which 54.4% were women and 45.6% were men. The study of the subjects with greater test anxiety was determined by the Pearson´s chi-squared test. Gender and course differences were analyzed by a two-factor ANOVA. The results showed that the subjects that generated more test anxiety were those related to the scientific field. In addition, significantly higher levels of test anxiety were found in the students of the upper grades. No gender differences were found. The interaction between school year and gender was not statistically significant. Some psychological and educational guidelines to reduce or eliminate test anxiety in elementary school students are proposed

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters