732 research outputs found
Displasia Epifisaria Hemimélica en rótula: (descripción de un nuevo caso y revisión bibliográfica)
Se describe un nuevo caso de Displasia Epifisaria Hemimélica que
asienta en una legalización muy poco frecuente cual es la rótula. Realizan
una amplia revisión bibliográfica de la literatura mundial y se comentan
las variaciones observadas en cuanto al cuadro clínico, diagnóstico y diagnóstico
diferencial.The authors describe a new case of Dysplasia Epiphysealis
Hemimelica with affectation of the patela. It is a localization very
infrequent.
They have made a review of the literature and analyse the
variations observed as for clinical findings, diagnosis and differential
diagnosis
High precision determination of sea level height reached by Belgranense Ingression for North of Buenos Aires and South of Santa Fe and Entre Ríos, Argentina
En el presente trabajo se llevó a cabo, mediante técnicas geodésicas de alta precisión, la determinación de las cotas alcanzadas porel nivel del mar en depósitos aflorantes asignables a la ingresión Belgranense (Pleistoceno tardío), la cual representa el punto másalto del nivel del mar (EIM 5e) durante el Cuaternario. Las localidades relevadas en este estudio pertenecen al sector norte de laingresión y se encuentran ubicadas en el noreste de la provincia de Buenos Aires y extremo sur de las provincias de Santa Fe y EntreRíos. A partir de los datos relevados y en combinación con información preexistente y un modelo de elevación digital (MDE), se realizóuna reconstrucción tentativa de la paleolínea de costa de la ingresión Belgranense. Ante las diferencias de elevaciones ortométricaspresentadas (de aproximadamente 4 m entre los afloramientos estudiados), queda abierta, subsidiariamente, la posibilidad de unainfluencia neotectónica en el área. Se discuten los resultados especialmente en relación con eventos sísmicos históricos y recientes,principalmente aquellos registrados a fines del año 2018 en la provincia de Buenos Aires.In this work, we perform measurements of the sea level orthometric heights using high precision geodetic techniques in deposits belonging to the Belgranense ingression (Late Pleistocene) which represents the highest point of sea level (MIS 5e) during the Quaternary. The outcrops represent the northern sector of the ingression and are located in the northeast region of the province of Buenos Aires and south of the provinces of Santa Fe and Entre Ríos. Subsequently, we created a tentative reconstruction of the Belgranense paleo-coastline based on the data collected, previous information and a digital elevation model (MDE). Given the differences in orthometric heights presented (about 4 meters between the outcrops studied), possible neotectonic influence remains open. We discuss the results in the context of historical and recent seismic events, particularly those registered at the end of 2018 in the province of Buenos Aires.Fil: Cappellotto, Luiggina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Acosta, Ayelén M.C.. Ministerio de Defensa. Instituto Geografico Nacional; ArgentinaFil: Perez, Daniel José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Orgeira, Maria Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Gómez, Demián. Ministerio de Defensa. Instituto Geografico Nacional; Argentin
Is Vtb=1 ?
The strongest constraint on Vtb presently comes from the 3 x 3 unitarity of
the CKM matrix, which fixes Vtb to be very close to one. If the unitarity is
relaxed, current information from top production at Tevatron still leaves open
the possibility that Vtb is sizably smaller than one. In minimal extensions of
the standard model with extra heavy quarks, the unitarity constraints are much
weaker and the EW precision parameters entail the strongest bounds on Vtb. We
discuss the experimental perspectives of discovering and identifying such new
physics models at the Tevatron and the LHC, through a precise measurement of
Vtb from the single top cross sections and by the study of processes where the
extra heavy quarks are produced.Comment: 19 pages, 8 figure
Lepton flavor violating signals of a little Higgs model at the high energy linear colliders
Littlest Higgs model predicts the existence of the doubly charged
scalars , which generally have large flavor changing couplings
to leptons. We calculate the contributions of to the lepton
flavor violating processes and , and compare our numerical results with the current
experimental upper limits on these processes. We find that some of these
processes can give severe constraints on the coupling constant and the
mass parameter . Taking into account the constraints on these free
parameters, we further discuss the possible lepton flavor violating signals of
at the high energy linear collider
experiments. Our numerical results show that the possible signals of
might be detected via the subprocesses in the future experiments.Comment: 16 pages, 7 figures. Discussions and references added, typos
correcte
Fully differential W' production and decay at next-to-leading order in QCD
We present the fully differential production and decay of a W' boson, with
arbitrary vector and axial-vector couplings, to any final state at
next-to-leading order in QCD. We demonstrate a complete factorization of
couplings at next-to-leading order in both the partial width of the W' boson,
and in the full two-to-two cross section. We provide numerical predictions for
the contribution of a W' boson to single-top-quark production, and separate
results based on whether the mass of the right-handed neutrino (nu_R) is light
enough for the leptonic decay channel to be open. The single-top-quark analysis
will allow for an improved direct W' mass limit of 525-550 GeV using data from
run I of the Fermilab Tevatron. We propose a modified tolerance method for
estimating parton distribution function uncertainties in cross sections.Comment: 23 pages, revtex3, 13 ps fig
The fully differential single-top-quark cross section in next-to-leading order QCD
We present a new next-to-leading order calculation for fully differential
single-top-quark final states. The calculation is performed using phase space
slicing and dipole subtraction methods. The results of the methods are found to
be in agreement. The dipole subtraction method calculation retains the full
spin dependence of the final state particles. We show a few numerical results
to illustrate the utility and consistency of the resulting computer
implementations.Comment: 37 pages, latex, 2 ps figure
Predictive Model of School Dropouts in Higher Education: An Approach From Data Mining Using the CRISP-DM Methodology
Este artículo presenta el desarrollo de un modelo para predecir, de manera temprana y oportuna, casos de estudiantes que muestren un potencial riesgo de deserción escolar, mediante el uso de técnicas de minería de datos. La deserción escolar a nivel superior es un problema multifactorial y complejo de analizar por la intervención de elementos de diversa índole, como factores familiares, académicos, educacionales, la situación económica familiar, las habilidades intelectuales de los estudiantes o la didáctica de los profesores. Este gran volumen de información a analizar no es fácilmente manejable con técnicas estadísticas tradicionales, sino que se precisa buscar estrategias que permitan operar con los bancos de datos de modo más eficiente y rápido. En el desarrollo de la propuesta se aplicó de una manera novedosa la minería de datos, para explorar los cambios en los comportamientos de los estudiantes, vinculados a diferentes causas de abandono escolar, utilizando la metodología CRISP-DM, con datos de 1,374 estudiantes de una institución de educación superior. Los resultados muestran las técnicas utilizadas para identificar y seleccionar factores asociados a la deserción estudiantil y los algoritmos para generar los modelos predictivos, de los cuáles pudo seleccionarse el más preciso, con mayor puntuación y facilidad de interpretación.This article presents the development of a model to predict, in an early and timely manner, cases of students who show a potential risk of dropping out of school, through the use of data mining techniques. High school dropout is a multifactorial and complex problem to analyze due to the intervention of diverse elements, such as family, academic, educational factors, the family economic situation, the intellectual abilities of the students or the didactics of the teachers. This large volume of information to be analyzed is not easily manageable with traditional statistical techniques, but it is necessary to find strategies that allow operating with data banks more efficiently and quickly. In the development of the proposal, data mining was applied in a novel way to explore changes in student behaviors, linked to different causes of school dropout, using the CRISP-DM methodology, with data from 1,374 students from an institution of higher education. The results show the techniques used to identify and select factors associated with student dropout, and the algorithms to generate predictive models, from which the most precise one could be selected, with the highest score and ease of interpretation
D* Production in Deep Inelastic Scattering at HERA
This paper presents measurements of D^{*\pm} production in deep inelastic
scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The
data have been taken with the ZEUS detector at HERA. The decay channel
(+ c.c.) has been used in the study. The
cross section for inclusive D^{*\pm} production with
and is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region
{ GeV and }. Differential cross
sections as functions of p_T(D^{*\pm}), and are
compared with next-to-leading order QCD calculations based on the photon-gluon
fusion production mechanism. After an extrapolation of the cross section to the
full kinematic region in p_T(D^{*\pm}) and (D^{*\pm}), the charm
contribution to the proton structure function is
determined for Bjorken between 2 10 and 5 10.Comment: 17 pages including 4 figure
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