3,995 research outputs found
Reflexiones entorno a las aportaciones de José María Izquierdo Arroyo a la representación y la organización del conocimiento: Ambición teórica, perspectiva humanística y compromiso académico
Reflexiones sobre la aportación de José María Izquierdo Arroyo al campo de la representación y la organización del conocimiento, realizadas con motivo del homenaje por su jubilación. Se trata de uno de los investigadores españoles en organización del conocimiento que han proporcionado una perspectiva más original e independiente, a la par que sólidamente interdisciplinar, de nuestra disciplina desde fundamentos filosóficos, lógicos, lingüísticos y semióticos. Se destaca especialmente su esfuerzo por contribuir a una síntesis e integración teórica del área de conocimiento desde unas sólidas bases interdisciplinares, así como su perspectiva humanística dialogante, abierta y esperanzadora
P246 PREVALENCE AND VIRAL LOAD OF PARVOVIRUS B19, VARICELLA-ZOSTER VIRUS, AND HUMAN HERPESVIRUS-6 IN MESENCHYMAL STEM CELLS OF PATIENTS WITH OSTEOARTHRITIS
Aplicaciones en la región de Murcia de la información de ocupación de suelo en España (SIOSE)
Finalizadas las tareas del proyecto del Sistema de Información de Ocupación del Suelo en España (SIOSE), se
plantea el aprovechamiento de la información obtenida de las múltiples bases de datos geográficas. En esta nueva
fase, se ha propuesto desarrollar herramientas que faciliten la explotación de dichas bases de datos geográficas,
mediante un conjunto de aplicaciones software. Además, y como un primer paso hacia la integración dentro de una
infraestructura de datos espaciales (IDE) regional, ofrecer servicios basados en los estándares de publicación de
información espacial en internet según el Open Geospatial Consortium (OGC), que permitan la visualización y consul-
ta de los datos elaborados, con el objetivo de su difusión con el mayor grado posible.With the project completed, the information system of land use in Spain (SIOSE) takes the opportunity to use the
information obtained from multiple geographic databases. In this new phase, it is proposed to develop tools that
facilitate the work of these geographic databases through a set of software applications. In addition, as a first step
towards integration into a regional spatial data infrastructure (SDI), providing standards-based services for spatial
information published online by the Open Geospatial Consortium (OGC) which enable visualization and query the
data produced with the aim of its distribution with the greatest possible degree
Dataset on water–glycerol flow in a horizontal pipeline with and without leaks
The dataset presented in this article was collected in a laboratory flow circuit, which was designed to investigate highviscosity flows. The data set is composed of 1200 s (equivalent to 12,000 samples) of mass flow and pressure measurements taken at five points along the pipeline. The first 300 s were recorded when the flow in the loop was composed only of glycerol. The remaining data were acquired when the flow was composed of a water–glycerol mixture. During the data acquisition, two extractions were produced. The research reported in [1] uses 160 s of the data provided here. This article explains in detail the experimental set-up and the principal instruments used for obtaining the dataset. The dataset is in the form of seven columns: Time, Mass Flow, Pressure 1, Pressure 2, Pressure 3, Pressure 4, Pressure 5, in supplementary Excel and Matlab files
Shape-resonant superconductivity in nanofilms: from weak to strong coupling
Ultrathin superconductors of different materials are becoming a powerful
platform to find mechanisms for enhancement of superconductivity, exploiting
shape resonances in different superconducting properties. Here we evaluate the
superconducting gap and its spatial profile, the multiple gap components, and
the chemical potential, of generic superconducting nanofilms, considering the
pairing attraction and its energy scale as tunable parameters, from weak to
strong coupling, at fixed electron density. Superconducting properties are
evaluated at mean field level as a function of the thickness of the nanofilm,
in order to characterize the shape resonances in the superconducting gap. We
find that the most pronounced shape resonances are generated for weakly coupled
superconductors, while approaching the strong coupling regime the shape
resonances are rounded by a mixing of the subbands due to the large energy gaps
extending over large energy scales. Finally, we find that the spatial profile,
transverse to the nanofilm, of the superconducting gap acquires a flat behavior
in the shape resonance region, indicating that a robust and uniform multigap
superconducting state can arise at resonance.Comment: 7 pages, 4 figures. Submitted to the Proceedings of the Superstripes
2016 conferenc
Betti numbers for numerical semigroup rings
We survey results related to the magnitude of the Betti numbers of numerical
semigroup rings and of their tangent cones.Comment: 22 pages; v2: updated references. To appear in Multigraded Algebra
and Applications (V. Ene, E. Miller Eds.
Aislamiento de un extracto de BMP y estudio anatomopatológico del fenómeno de inducción ósea tras su implante en defectos óseos
El objetivo del presente trabajo fue determinar el potencial osteogénico de
la proteína morfogenética ósea (BMP) en la reparación de grandes defectos diafisarios.
Además, se investiga la acción coadyuvante de la fibronectina (FN). La BMP fue extraída
a partir de hueso cortical bovino. Se utilizaron un total de 108 ratas Sprague Dawley. En
cada animal, se resecó un segmento de diáfisis femoral de 1.5 cm, siendo inmovilizado el
defecto óseo con una aguja en omega. Se rellenó el defecto implantando 25 mg de BMP
con o sin 0.5 mg de FN en una cápsula de gelatina (36 animales en ambos grupos). Los
resultados se compararon con los obtenidos en otro grupo (36 animales) en el que sólo se
implantó FN que sirvió como grupo control. El proceso de reparación se evaluó mediante
métodos histológicos y ultraestructurales. La aparición del fenómeno de inducción ósea
con reconstrucción del defecto óseo fue mayor en el grupo con implante de BMP más FN
(23 animales, 64%) que en el grupo en el que sólo se implantó BMP (20 animales, 56%).
Ningún animal del grupo control manifestaba signos de inducción ósea.The aim of the present work was to evaluate the osteogenic potential of
Bone Morphogenetic Protein (BMP) for reparation of large segmental bone defects. In addition,
the coadjuvant efect of fibronectin (FN) was investigated. BMP was partially purified
from bovine cortical bone. A total of 108 Sprague Dawley rats were used in the experiment.
Diaphyseal segments of the femur (1.5 cm) were removed in each animal, manteinant
the bone defect with a wire. A gelatine capsula containing 25 mg of BMP without or
with 0.5 mg of FN, were implanted into the bone defect (36 animal in each group).
Results were compared to those obtained in a control group (36 animals) in which FN
alone was implanted. The bone repair process was assessed by histologic and ultrastructural
methods. Bone induction with reconstruction of the defect was found more of ten in
the group with both BMP and FN implanted (23 animals, 64%) than in the group with
BMP implant alone (20 animals, 56%). Animals of the control group showed no bone induction.
The results suggest that BMP augments the capacity of the host bed to sucessfully
regenerate large segmental bone defects. FN seens to increase bone induction. This
protein migth stabilize BMP locally improving contact between BMP and the surrounding
cells
Unprecedented tuning of the in-plane easy axis in (100) magnetite films grown by IR-PLD
Conference paper presented at the IEEE International Magnetics Conference, held in Beijing (China) on May 11-15th, 2015.Magnetite (Fe3O4) is attracting much interest in the last years due to its robust ferrimagnetism down to nanometer thickness, good electrical conductivity and presumed half-metal character. In particular, Fe3O4 films are studied as ideal cases for the design of improved bulk magnets [1] and have been tentatively used in spin-valves and spin-LEDs. Fe3O4 presents a low-temperature metal-insulator transition, the Verwey transition (TV) which has also been proposed for spintronic applications. An open question is to what extent the preparation of Fe3O4 films can affect their detailed magnetic properties, such as the magnetic anisotropy axis. This information is required to efficiently apply Fe3O4 in technological multiphase magnets and spintronic applications [1]. Most of studies dealing with bulk and Fe3O4 thin film systems show room temperature (RT) in-plane magnetic easy axis. By contrast, we show in this work the preparation of pure stoichiometric Fe3O4 thin films with RT easy axes along the in-plane directions [2], i.e. rotated by 45º respect to previous studies. Fe3O4 films have been grown by ablation from a sintered hematite target using a nanosecond infrared (IR) laser at 1064 nm and a substrate temperature of 750 K [3]. Single crystal substrates of SrTiO3, MgAl2O4 and MgO have been used. The films were characterized using XRD, AFM, Raman and Mössbauer spectroscopies, vectorial magneto-optical Kerr effect microscopy (v-MOKE) and SQUID magnetometry. All films consisted of stoichiometric Fe3O4 and presented a Verwey transition at TV=115-118 K. RT in-plane hysteresis loops were measured by vectorial-MOKE as a function of the direction of the applied magnetic field in the 0º-360º range with an angular step of 5º. For all epitaxial films under study, the highest coercivity and remanence are found at 0º, 90º, 180º and 270º (i.e. directions), thus orthogonal to each other, while the lowest coercivity values are found between them [Figures 1(a) and 1(b), respectively]. This results in a well-defined four-fold symmetry indicative of biaxial magnetic anisotropy [2]. In order to verify this result, ferromagnetic resonance (FMR) experiments have been carried out at 9.4 GHz frequency. The angular dependence of the in-plane resonance field at RT for the Fe3O4 layers proves that the easy axes are indeed the in-plane directions (Fig. 2). Furthermore, spin-polarized low-energy electron microscopy (SPLEEM) has allowed imaging the individual magnetic domains at the surface of the films [2]. The magnetic domains present magnetization vectors along the in-plane ¿100¿ directions, while the domain walls are aligned with the in-plane ¿110¿ directions. The most probable cause for the observed magnetization easy-axis direction is the orientation of the anti-phase domain boundaries (APBs). It is known that depending on the orientation of the APBs, they can couple both ferromagnetically or antiferromagnetically the magnetite grains that lie across the boundary. We thus propose that the particular distribution and orientation of APBs that our growth conditions promote are responsible for the observed easy-axis directions of our films. Consequently, all angular studies here shown in addition to SPLEEM experiments demonstrate easy-axis orientation along in-plane directions, i.e., differing from that of bulk magnetite or films prepared by other techniques, and thus demonstrating the possibility of tuning the easy axis orientation in Fe3O4 films
The electron-furfural scattering dynamics for 63 energetically open electronic states
We report on integral-, momentum transfer-and differential cross sections for elastic and electronically inelastic electron collisions with furfural (C5H4O2). The calculations were performed with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (N-open) at either the static-exchange (N-open ch-SE) or the static-exchange-plus-polarisation (N-open ch-SEP) approximation was employed to calculate the scattering amplitudes at impact energies lying between 5 eV and 50 eV, using a channel coupling scheme that ranges from the 1ch-SEP up to the 63ch-SE level of approximation depending on the energy considered. For elastic scattering, we found very good overall agreement at higher energies among our SMCPP cross sections, our IAM-SCAR+I cross sections and the experimental data for furan (a molecule that differs from furfural only by the substitution of a hydrogen atom in furan with an aldehyde functional group). This is a good indication that our elastic cross sections are converged with respect to the multichannel coupling effect for most of the investigated intermediate energies. However, although the present application represents the most sophisticated calculation performed with the SMCPP method thus far, the inelastic cross sections, even for the low lying energy states, are still not completely converged for intermediate and higher energies. We discuss possible reasons leading to this discrepancy and point out what further steps need to be undertaken in order to improve the agreement between the calculated and measured cross sections. (C) 2016 AIP Publishing LLC
A double-sided, shield-less stave prototype for the ATLAS upgrade strip tracker for the high luminosity LHC
A detailed description of the integration structures for the barrel region of the silicon strips tracker of the ATLAS Phase-II upgrade for the upgrade of the Large Hadron Collider, the so-called High Luminosity LHC (HL-LHC), is presented. This paper focuses on one of the latest demonstrator prototypes recently assembled, with numerous unique features. It consists of a shortened, shield-less, and double sided stave, with two candidate power distributions implemented. Thermal and electrical performances of the prototype are presented, as well as a description of the assembly procedures and tools
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