The thickness of a liquid layer on the free surface of ice as obtained from computer simulation

Molecular dynamic simulations were performed for ice Ih with a free surface by using four water models, SPC/E, TIP4P, TIP4P/Ice and TIP4P/2005. The behavior of the basal plane, the primary prismatic plane and of the secondary prismatic plane when exposed to vacuum was analyzed. We observe the formation of a thin liquid layer at the ice surface at temperatures below the melting point for all models and the three planes considered. For a given plane it was found that the thickness of a liquid layer was similar for different water models, when the comparison is made at the same undercooling with respect to the melting point of the model. The liquid layer thickness is found to increase with temperature. For a fixed temperature it was found that the thickness of the liquid layer decreases in the following order: the basal plane, the primary prismatic plane, and the secondary prismatic plane. For the TIP4P/Ice model, a model reproducing the experimental value of the melting temperature of ice, the first clear indication of the formation of a liquid layer appears at about -100 Celsius for the basal plane, at about -80 Celsius for the primary prismatic plane and at about -70 Celsius for the secondary prismatic plane.Comment: 41 pages and 13 figure

El pensament social dels estudiants de mestre : llums i ombres

La formació del pensament social significa ensenyar a analitzar la realitat social des d'una perspectiva crítica, amb la finalitat última d'intervenir en la societat i de participar de manera democràtica. Per formar el pensament social és imprescindible ensenyar a opinar de manera raonada i a emetre judicis argumentats. Aquesta recerca se centra en tres aspectes del coneixement social, entre els quals identifiquem una clara relació: el sistema de creences, les opinions i l'emissió de judicis

Effectiveness and safety of obeticholic acid in a Southern European multicenter cohort of patients with primary biliary cholangitis and suboptimal response to ursodeoxycholic acid

Background Obeticholic acid (OCA) was recently approved as the only on-label alternative for patients with primary biliary cholangitis (PBC) with intolerance or suboptimal response to ursodeoxycholic acid (UDCA). However, few data are available outside clinical trials. Aim To assess the effectiveness and safety of OCA in a real-world cohort of patients with non-effective UDCA therapy. Methods Open-label, prospective, real-world, multicentre study, enrolling consecutive patients who did not meet Paris II criteria, from 18 institutions in Spain and Portugal. Effectiveness was assessed by the changes in GLOBE and UK-PBC scores from baseline. POISE and Paris II criteria were evaluated after 12 months of OCA . Liver fibrosis was evaluated by FIB-4 and AST to platelet ratio index (APRI). Results One hundred and twenty patients were eligible, median time since PBC diagnosis 9.3 (4.0-13.8) years, 21.7% had cirrhosis, and 26.7% received had previous or concomitant treatment with fibrates. Seventy-eight patients completed at least 1 year of OCA. The Globe-PBC score decreased to 0.17 (95% CI 0.05 to 0.28; P = 0.005) and the UK-PBC score decreased to 0.81 (95% CI -0.19 to 1.80; P = 0.11). There was a significant decrease in alkaline phosphatase of 81.3 U/L (95% CI 42.5 to 120; P < 0.001), ALT 22.1 U/L (95% CI 10.4 to 33.8; P < 0.001) and bilirubin 0.12 mg/dL (95% CI 0 to 0.24; P = 0.044). FIB-4 and APRI remained stable. According to the POISE criteria, 29.5% (23 out of 78) achieved response. The adverse events rate was 35%; 11.67% discontinued (8.3% due to pruritus). Conclusions This study supports data from phase III trials with significant improvement of PBC-Globe continuous prognostic marker score among OCA-treated patients with good tolerability

Mapa de Favorabilidad Geotérmica Aplicando el Método de Análisis Geothermal Play Fairway Área 2, Sierras Subandinas, Cuenca de Tucumán y su Extensión en la Provincia de Santiago del Estero, Argentina.

Fil: Asato, Carlos Gabriel. Servicio Geológico Minero Argentino. Instituto de Geología y Recursos Minerales; Argentina.Fil: Conde Serra, Alejandro. Servicio Geológico Minero Argentino. Instituto de Geología y Recursos Minerales; Argentina.Fil: Seggiaro, Raúl E. Servicio Geológico Minero Argentino. Centro Salta; Argentina.Fil: Molina, Eduardo A. Servicio Geológico Minero Argentino. Centro Salta; Argentina.Fil: Cegarra, Marcelo I. Servicio Geológico Minero Argentino. Instituto de Geología y Recursos Minerales; Argentina.Fil: Hernández, Mariano, Servicio Geológico Minero Argentino. Centro General Roca; Argentina.Fil: Carrizo, Noelia. Servicio Geológico Minero Argentino. Sub Centro Catamarca; Argentina.Fil: Peralta Arnold, Yésica J. Mariano, Servicio Geológico Minero Argentino. Centro Jujuy; Argentina.Fil: Larcher, Nicolás. Servicio Geológico Minero Argentino. Centro Jujuy; Argentina.Fil: Fernández, Diego. Servicio Geológico Minero Argentino. Centro Tucumán; Argentina.Fil: Peroni, Javier Ignacio. Servicio Geológico Minero Argentino. Instituto de Geología y Recursos Minerales; Argentina.Fil: Ramé, Gustavo A. Servicio Geológico Minero Argentino. Centro Córdoba; Argentina.Fil: Naón, Virginia. Servicio Geológico Minero Argentino. Instituto de Geología y Recursos Minerales; Argentina.En la presente contribución se da a conocer el resultado de la aplicación del método Geothermal Play Fairway en una región de aproximadamente 71.000 km2 que comprende parte de las Sierras Subandinas, Cordillera Oriental, Sistema de Santa Bárbara y Llanura Chaco-Pampeana, en las provincias de Jujuy, Salta, Tucumán, Santiago del Estero y Catamarca, denominada en su conjunto Área 2. De acuerdo a esta metodología que integra y modela diversos tipos de datos geológicos directos e indirectos, se generaron mapas de evidencias correspondientes a los tres factores geológicos principales para la existencia de un recurso geotermal: los subsistemas de Permeabilidad, Fluidos y Calor. Estos tres componentes en conjunto integran el mapa resultante de Potencial Geotérmico del Área 2. Se asignó mayor influencia en el cómputo de favorabilidad geotérmica al subsistema de Permeabilidad, el cual está condicionado por la presencia de estructuras (fallas y lineamientos) o conjuntos de estructuras que generan los espacios necesarios para el ascenso de fluidos geotermales. Estos rasgos, determinados por mapeo geológico y por métodos geofísicos en subsuelo, fueron ponderados según su tipología, edad, interacción con otras estructuras y profundidad de los sismos asociados a ellos. En segundo lugar de importancia se consideró al subsistema Calor, en donde se utilizaron evidencias geoquímicas (mediante cálculos geotermométricos de muestras de aguas termales), información de pozos y anomalías geofísicas, que determinaron una participación de fuentes profundas de calor. Finalmente, el menor peso fue asignado al subsistema de Fluidos, integrado por expresiones hidrotermales cuyos análisis hidroquímicos permitieron deducir la participación de fluidos geotérmicos de alta entalpía. La combinación de los distintos mapas de evidencias con sus respectivas ponderaciones constituye el mapa final de favorabilidad geotérmica para el Área 2, en el cual, se destacan zonas o áreas con características distintivas: Zona Norte: Se circunscribe a la región del Sistema de Santa Bárbara y es clasificada como un sistema conductivo. Se encuentran gradientes geotérmicos normales y se interpretan reservorios geotérmicos profundos asociados a fallas de alto ángulo que juegan un rol preponderante en la conducción de fluidos y/o la compartimentalización de bloques (barreras). Zona Sur: Abarca la llanura Tucumano-Santiagueña y se la clasifica como un sistema convectivo-conductivo. Presenta gradientes geotérmicos anómalos diseminados por el área, con indicios de fluencia ascendente de calor de origen mantélico a través del basamento y en asociación con estructuras profundas. Otros sectores con probabilidad de albergar sistemas ciegos (no aflorantes)

Longitudinal outcomes of obeticholic acid therapy in ursodiol-nonresponsive primary biliary cholangitis: Stratifying the impact of add-on fibrates in real-world practice

Background Suboptimal response to ursodeoxycholic acid occurs in 40% of primary biliary cholangitis (PBC) patients, affecting survival. Achieving a deep response (normalisation of alkaline phosphatase [ALP] and bilirubin ≤0.6 upper limit of normal) improves survival. Yet, the long-term effectiveness of second-line treatments remains uncertain. Aims To evaluate the long-term effectiveness of obeticholic acid (OCA) ± fibrates. Focusing on biochemical response (ALP ≤1.67 times the upper limit of normal, with a decrease of at least 15% from baseline and normal bilirubin levels), normalisation of ALP, deep response and biochemical remission (deep response plus aminotransferase normalisation). Methods We conducted a longitudinal, observational, multicentre study involving ursodeoxyccholic acid non-responsive PBC patients (Paris-II criteria) from Spain and Portugal who received OCA ± fibrates. Results Of 255 patients, median follow-up was 35.1 months (IQR: 20.2–53). The biochemical response in the whole cohort was 47.2%, 61.4% and 68.6% at 12, 24 and 36 months. GLOBE-PBC and 5-year UK-PBC scores improved (p < 0.001). Triple therapy (ursodeoxycholic acid plus OCA plus fibrates) had significantly higher response rates than dual therapy (p = 0.001), including ALP normalisation, deep response and biochemical remission (p < 0.001). In multivariate analysis, triple therapy remained independently associated with biochemical response (p = 0.024), alkaline phosphatase normalisation, deep response and biochemical remission (p < 0.001). Adverse effects occurred in 41.2% of cases, leading to 18.8% discontinuing OCA. Out of 55 patients with cirrhosis, 12 developed decompensation. All with baseline portal hypertension. Conclusion Triple therapy was superior in achieving therapeutic goals in UDCA-nonresponsive PBC. Decompensation was linked to pre-existing portal hypertension

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde