5,108 research outputs found

    Precision stellar radial velocity measurements with FIDEOS at the ESO 1-m telescope of La Silla

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    We present results from the commissioning and early science programs of FIDEOS, the new high-resolution echelle spectrograph developed at the Centre of Astro Engineering of Pontificia Universidad Catolica de Chile, and recently installed at the ESO 1m telescope of La Silla. The instrument provides spectral resolution R = 43,000 in the visible spectral range 420-800 nm, reaching a limiting magnitude of 11 in V band. Precision in the measurement of radial velocity is guaranteed by light feeding with an octagonal optical fibre, suitable mechanical isolation, thermal stabilisation, and simultaneous wavelength calibration. Currently the instrument reaches radial velocity stability of = 8 m/s over several consecutive nights of observation

    TUNNEL GEOLOGY AS SEEN BY GEOLOGISTS: MANHATTAN, NEW YORK CITY

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    Current exploratory boring operations in and around Manhattan, New York City are providing geologists and geotechnical engineers with a plethora of new and interesting geological information, which has not been previously reported. The rocks encountered, mostly medium to high-grade metamorphic rocks, with both mafic and felsic intrusives, are highly variable in competency and mechanical durability. One of the most frequently encountered rock types is a garnetiferous-muscovite-biotite schist which grades into schistose gneiss and displays a wide variety of structural, compositional, and textural attributes. Metamorphic minerals showing the variable degree of metamorphism include graphite, talc, garnet, kyanite, tourmaline, emory, and occasionally sillimanite. The presence of magnetite-rich zones within the muscovite-garnet schist suggests a mechanism for the concentration of iron during metamorphism. Concentrations of garnet both in the schist and intrusive pegmatite is perhaps indicative of anatectic melting of the protolith. Marble is the dominant rock type east of CAMERON\u27S LINE and it varies from pure white calcitic to dolomitic coarsely crystalline marble, to siliceous calcitic to dolomitic marble. In places, highly pyrite-rich zones, perhaps suggesting hydrothermal alteration of the parent rock due to subsequent mineral-rich fluid flow, are observed. The timing of the sulfide-rich fluid-flow through the original bedrock is yet to be determined. Partial dissolution of marble at various depths has resulted in void (cave) formation and has posed a threat to the boring operations. Rocks of lower abundance include amphibolite, granodiorite, quartzite, serpentinite, and aplite. The overall structural fabric is controlled by the Taconic and Acadian Orogenic events and manifested in the development of characteristic foliation, joint patterns, intrusives, and the degree of metamorphism of the protoliths

    Dependencia emocional en estudiantes de Medicina

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    Objective: To determine the emotional dependence of students of medicine in a public university. Methods: A cross-sectional study was carried-out applying the 42-item scale of emotional dependence of Ancima, Caballero, Cirilo y Aguirre (2013) with dichotomous responses (yes/no); 332 five-year medical students were selected; a non- probabilistic sample of 303 students was finally recruited. Results: 183 (60.39%) were females: mean age was 24 years; only 2.98% were stables and 90.39% had a tendency for dependence. Conclusions: Five-year medical students had a marked tendency for dependence, especially female students.Objetivos: Identificar la dependencia emocional en los estudiantes de medicina de universidad pública. Material y métodos: Estudio cuantitativo, no experimental, exploratorio, descriptivo, transversal. Se aplicó la escala de dependencia emocional de Ancima, Caballero, Cirilo y Aguirre (2013) integrada por 42 ítems. Las respuestas se establecen dicotómicamente Si o no. La población se conformó por 332 estudiantes de medicina de quinto año de una universidad pública. La escala fue aplicada a 303 estudiantes una muestra no probabilística, por conveniencia. Resultados: De 303 estudiantes, 183 (60,39%) eran del género femenino y 120 (39,60%) masculino, con promedio de edad de 24 años, con una desviación estándar de 1,46. Solo el 2,98% fueron “estables” y el 90,39% con “tendencia a la dependencia”. Conclusiones: Los estudiantes de medicina presentan una marcada tendencia a la dependencia emocional. Siendo las mujeres las más dependientes

    Montaje y estandarizacion de Elisa IgG para el diagnostico de distomatosis humana.

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    68 p.Con el propĂłsito de montar una tĂŠcnica de diagnĂłstico precoz para Distomatosis humana, se realizo la tĂŠcnica de ELISA Ig G. Se preparĂł anfĂ­geno somĂĄtico y secretor - excretor a partir de ejemplares vivos de D. hepĂĄtico. Se caracterizaron ambos anfĂ­genos electroforĂŠticamente en geles de poliacrilamida, seleccionando el anfĂ­geno mas apropiado para montar la tĂŠcnica de ELISA. Se realizĂł el montaje de la tĂŠcnica con el anfĂ­geno seleccionado y se estandarizo la tĂŠcnica de ELISA Ig G Distomatosis. Debido a que el periodo prepatente, periodo comprendido entre la ingesta del elemento infectante y la apariciĂłn de los huevos, de la Distomatosis es largo, 3 a 4 meses, el diagnostico precoz de la fase aguda se Iogra a travĂŠs de tĂŠcnicas de inmunodiagnostico, ya que en este caso no podrĂ­a ser confirmada la infecciĂłn tras la observaciĂłn de los huevos. De este modo, se ensayo la tĂŠcnica de ELISA Ig G Distomatosis, por presentar mayor sensibilidad y especificidad que otras tĂŠcnicas inmunolĂłgicas. Con este test se obtuvo una sensibilidad de 87 % y una especificidad de 96 % al comparar los resultados de los 15 pacientes con Distomatosis vs sujetos presuntamente sanos ( n = 50 ). De igual forma se comparĂł el grupo de los pacientes con Distomatosis vs pacientes con otras parasitosis ( n = 50 ), obteniendo una sensibilidad de 87 % y una especificidad de 100 %. Con estos resultados, se concluye que para el diagnostico serologico de Distomatosis, la tĂŠcnica de ELISA montada en el laboratorio, podrĂ­a ser utilizada de rutina en el diagnostico serologico

    Discovery of the broad-lined Type Ic SN 2013cq associated with the very energetic GRB 130427A

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    Long-duration gamma-ray bursts (GRBs) at z < 1 are in most cases found to be accompanied by bright, broad-lined Type Ic supernovae (SNe Ic-BL). The highest-energy GRBs are mostly located at higher redshifts, where the associated SNe are hard to detect observationally. Here we present early and late observations of the optical counterpart of the very energetic GRB 130427A. Despite its moderate redshift z = 0.3399+/-0.0002, GRB 130427A is at the high end of the GRB energy distribution, with an isotropic-equivalent energy release of Eiso ~ 9.6x10^53 erg, more than an order of magnitude more energetic than other GRBs with spectroscopically confirmed SNe. In our dense photometric monitoring, we detect excess flux in the host-subtracted r-band light curve, consistent with what expected from an emerging SN, ~0.2 mag fainter than the prototypical SN 1998bw. A spectrum obtained around the time of the SN peak (16.7 days after the GRB) reveals broad undulations typical of SNe Ic-BL, confirming the presence of a SN, designated SN 2013cq. The spectral shape and early peak time are similar to those of the high expansion velocity SN 2010bh associated with GRB 100316D. Our findings demonstrate that high-energy long-duration GRBs, commonly detected at high redshift, can also be associated with SNe Ic-BL, pointing to a common progenitor mechanism.Comment: 12 pages, 4 figures, 1 table, accepted for publication in Ap

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+→μ+νW^+ \rightarrow \mu^+\nu and W−→μ−νW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

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

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    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
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