735 research outputs found
Resonancia magnética de difusión en pacientes con migraña
La Resonancia magnética de difusión (dMRI) se
basa en la detección de los movimientos microscópicos de las moléculas de
agua en los tejidos mediante la aplicación de gradientes en el campo
magnético aplicado. Esta técnica puede detectar anomalías en la sustancia
blanca cerebral que no son visibles en las secuencias convencionales de
Resonancia Magnética (RM). Algunos estudios en la literatura han reportado
propiedades anormales de la sustancia blanca en varias regiones del cerebro
de pacientes con migraña.
Nuestro objetivo es investigar los cambios microestructurales en la sustancia
blanca cerebral aparentemente normal entre sujetos con diagnóstico de
migraña en diferentes situaciones clínicas y controles sanos según lo revelado
por dMRI.
Desde la unidad de cefaleas del hospital clínico
universitario de Valladolid (HCUV) se seleccionaron 19 pacientes con
diagnóstico clínico de migraña según la versión beta de la III Edición de la
Clasificación Internacional de Cefaleas (CIC-3) (5 hombres y 14 mujeres de
37,3 ± 9,5 años) y 11 controles sanos emparejados (36,9 ± 12,5 años). Se
recogieron características demográficas y nosológicas de los pacientes.
Los volúmenes de dMRI fueron adquiridos en un escáner 3T (61 direcciones de
gradiente, valor b=1000 s/mm^2, tamaño del voxel 2x2x2 mm^3 y matriz
128x128 con 66 cortes que cubren todo el cerebro). Después de la estimación
del tensor de difusión, el conjunto de datos fue analizado mediante el método
TBSS (Tractografía basada en la Estadística). Las medidas escalares
analizadas fueron la anisotropía fraccional (FA), difusividad media (MD),
difusividad axial (AD), difusividad radial (DR) y el modo de tensor (TM).El análisis con TBSS reveló diferencias estadísticamente
significativas entre pacientes con migraña y controles sanos. Se objetivó una
disminución de los valores de FA y TM en los pacientes con diagnóstico de migraña, mientras que los valores de MD y RD aumentaron en este mismo
grupo (p < 0,05). No se observaron cambios significativos en los valores de AD.
Conclusiones: A pesar del reducido número de pacientes estudiado, se han
encontrado alteraciones generalizadas en la sustancia blanca cerebral en
pacientes con migraña que no existen en los controles sanos. Estas
alteraciones podrían constituirse como un biomarcador sensible para reflejar
una pérdida de sustancia blanca en estos pacientes, aunque habría que seguir
desarrollando esta idea en investigaciones futuras. La naturaleza
microestructural de los cambios encontrados requiere más estudio.Grado en Medicin
Adaptive channel selection for DOA estimation in MIMO radar
We present adaptive strategies for antenna selection for Direction of Arrival
(DoA) estimation of a far-field source using TDM MIMO radar with linear arrays.
Our treatment is formulated within a general adaptive sensing framework that
uses one-step ahead predictions of the Bayesian MSE using a parametric family
of Weiss-Weinstein bounds that depend on previous measurements. We compare in
simulations our strategy with adaptive policies that optimize the Bobrovsky-
Zaka{\i} bound and the Expected Cram\'er-Rao bound, and show the performance
for different levels of measurement noise.Comment: Submitted to the 25th European Signal Processing Conference
(EUSIPCO), 201
Coherently manipulating flying qubits in a quantum wire with a magnetic impurity
e study the effect of a magnetic impurity with spin-half on a single
propagating electron in a one-dimensional model system via the tight-binding
approach. Due to the spin-dependent interaction, the scattering channel for the
flying qubit is split, and its transmission spectrum is obtained. It is found
that, the spin orientation of the impurity plays the role as a spin state
filter for a flying qubit.Comment: 6 pages, 5 figure
El español coloquial en registros semiinformales. Análisis del español coloquial en entrevistas semidirigidas.
Trabajo de fin de Grado. Grado en Filología Hispánica. Curso académico 2019-2020La comunicación humana es un complejo proceso en el que intervienen múltiples variables con el fin de lograr nuestro objetivo. Se han conseguido grandes avances en las últimas décadas por medio de la Sociolingüística y la Pragmática para poder comprenderla cada vez mejor, no solo en lo relativo a los objetivos que se persiguen y los mecanismos que se llevan a cabo para ello, sino también en relación a las estructuras y rasgos prototípicos que aparecen en estos discursos orales.
Así, vamos a analizar, en concreto, un tipo de discurso oral, como es la entrevista semidirigida, basándonos en pares de entrevistas reales a un mismo individuo en varios medios, por lo que podremos distinguir los rasgos que se presentan en un registro que hemos denominado como semiinformal y un registro semiformal; además de realizar una comparación entre los que aparecen en una conversación coloquial y este registro semiinformal. Por otro lado, también estudiaremos las diferencias de estilo que pueden observarse, basándonos en las variables sociolingüísticas de sexo / género y edad de estas personas.
Para ello, nos hemos basado, fundamentalmente, en las obras de Antonio Briz y el grupo Val.Es.Co. , debido a que son quienes más han potenciado este estudio del discurso oral en el panorama nacional, concretamente en la conversación coloquial.
ENGLISH: Human communication is a complex process involving multiple variables in order to achieve our goal. Great advances have been made in recent decades through Sociolinguistics and Pragmatics in order to understand it better and better, not only in terms of the objectives pursued and the mechanisms used to achieve them, but also in relation to the structures and prototypical features that appear in these oral discourses.
Therefore, we are going to analyze, in particular, a type of oral discourse, such as the semi-directed interview, based on pairs of real interviews with the same individual in various media, so that we will be able to distinguish the features that appear in a register that we have called semi-informal and a semi-formal register; in addition to making a comparison between those that appear in a colloquial conversation and this semi-formal register. On the other hand, we will also study the differences in style that can be observed, based on the sociolinguistic variables of sex/gender and age of these people.
In order to do so, we have based ourselves, fundamentally, on the works of Antonio Briz and Val.Es.Co. group, because they are the ones who have most promoted this study of oral discourse in the national context, specifically in colloquial conversation
La traslación al crédito ects de la diplomatura en relaciones laborales : análisis y propuestas de mejora
El enfoque pedagógico del proceso de convergencia al Espacio Europeo de Educación Superior pretende una transformación superior de la docencia universitaria en la que el eje fundamental no sea la enseñanza sino el aprendizaje. De hecho, este principio básico promueve que sea necesario el cambio profundo de algunas de las directrices en las que se ha venido desenvolviendo dicha docencia hasta la actualidad. Desde el curso 2004/05, la Diplomatura de Relaciones Laborales de la Universidad de Huelva se encuentra inmersa en el proyecto piloto para la implantación del Sistema Europeo de Transferencia de Crédito. El trabajo realizado permite ofrecer una visión global de la influencia que ha tenido la puesta en marcha de la metodología ects en el alumnado. El presente estudio pretende analizar la percepción del alumnado sobre la experiencia piloto y la evolución de los resultados académicos de las diferentes asignaturas inmersas en dicho proyecto. Estas conclusiones permitirán ofrecer ciertas propuestas de mejora, teniendo en cuenta las aportaciones del alumnado como pieza clave en el proyecto.________________________________The pedagogical approach of the process of convergence to the European Space of
Superior Education pretends a transformation of university teaching in which
the fundamental axis is not the teaching but the learning. In fact, this basic
principle promotes that a profound change is necessary of some of the directives
in which this teaching has been developed up to the present time. From course
2004105, the Diploma in Labour Relations of the University of Huelva has been
immersed in the Pilot project for the Implantation of the European System of
Credit Transfer. The work realized allows a global vision of the influence that the
start of the methodology ECTS has had in the pupils. The present study tries to
analyze the perception of the pupils on the pilot experience and the evolution of
the academic results of the different subjects immersed in this project. These conclusions
will allow the offering of certain proposals for improvement, taking into
consideration the contributions of the pupils as a key piece in the project
Metal Accumulation by Jatropha curcas L. Adult Plants Grown on Heavy Metal-Contaminated Soil
Jatropha curcas has the ability to phytoextract high amounts of heavy metals during its first months just after seeding. Notwithstanding, there is scarce information about metal uptake by adult J. curcas plants. To shed light on this issue, 4-year-old J. curcas L. plants were planted in a soil mixture of peat moss and mining soil (high metals content), and the biomass growth and metal absorption during 90 days were compared with those of plants growing in peat moss. The main metal found in the mining soil was Fe (31985 mg kg-1) along with high amounts of As (23717 mg kg-1). After the 90-day phytoremediation, the plant removed 29% of Fe and 44% of As from the soil mixture. Results revealed that J. curcas L. translocated high amounts of metals to its aerial parts, so that translocation factors were much higher than 1. Because of the high translocation and bioaccumulation factors obtained, J. curcas L. can be regarded as a hyperaccumulator plant. Despite the great capacity of J. curcas L. to phytoremediate heavy-metal-contaminated soils, the main drawback is the subsequent handling of the metal-contaminated biomass, although some potential applications have been recently highlighted for this biomass.University of Seville (VIPPIT-2019-I.5
Altered Metal Homeostasis Associates with Inflammation, Oxidative Stress, Impaired Glucose Metabolism, and Dyslipidemia in the Crosstalk between Childhood Obesity and Insulin Resistance
Metals are redox-active substances that participate in central biological processes and may be
involved in a multitude of pathogenic events. However, considering the inconsistencies reported in the
literature, further research is crucial to disentangle the role of metal homeostasis in childhood obesity
and comorbidities using well-characterized cohorts and state-of-the-art analytical methods. To this end,
we studied an observational population comprising childrenwith obesity and insulin resistance, children
with obesity without insulin resistance, and healthy control children. A multi-elemental approach based
on the size-fractionation of metal species was applied to quantify the total content of various essential
and toxic elements in plasma and erythrocyte samples, and to simultaneously investigate the metal
fractions conforming the metalloproteome and the labile metal pool. The most important disturbances
in childhood obesity were found to be related to elevated circulating copper levels, decreased content of
plasmatic proteins containing chromium, cobalt, iron, manganese, molybdenum, selenium, and zinc, as
well as the sequestration of copper, iron, and selenium within erythrocytes. Interestingly, these metal
disturbances were normally exacerbated among children with concomitant insulin resistance, and in
turn were associated to other characteristic pathogenic events, such as inflammation, oxidative stress,
abnormal glucose metabolism, and dyslipidemia. Therefore, this study represents one-step further
towards a better understanding of the involvement of metals in the crosstalk between childhood obesity
and insulin resistance.This research was partially funded by the Spanish Government through Instituto de
Salud Carlos III (CP21/00120, PI18/01316). Á.G.-D. is supported by an intramural grant from the
Biomedical Research and Innovation Institute of Cádiz (LII19/16IN-CO24), and R.G.-D. is recipient
of a “Miguel Servet” fellowship (CP21/00120) funded by Instituto de Salud Carlos III
Radical reactions on pinene-oxide derivatives induced by Ti(III)
[EN]A practical, brief and selective synthesis of several pinene oxide derived terpenoids can be achieved from readily available starting materials. The key step is a radical reaction promoted by titanocene chloride
Titanocene-promoted stereoselective eliminations on epoxy alcohols derived from R-(−)-carvone
[EN]The reaction of several stereoisomeric epoxy alcohols, obtained from R-(−)-carvone, and their corresponding formates, acetates, and benzoates, promoted by Cp2TiCl has been studied. The different outcomes of the reaction of epoxy derivatives are rationalized in terms of mechanistically biased processes. The radicals emerging from oxirane cleavage provide two types of reaction: dehydroxylation (deoxycarbonylation) and dehydrogenation. The results offer considerable support for the radical elimination theory of hydroxyl, formyloxyl, and acetoxyl groups. The inability of tertiary radicals to be reduced by the Ti(III) complex is demonstrated unequivocally
- …