Validez de constructo de tres escalas de satisfacción del paciente mediante la estrategia de matrices multirrasgo-multimétodo

Se emplea el diseño de las matrices multirrasgo-multimétodo (MTMM) en la evaluación de la satisfacción del paciente. La muestra, extraída al azar simple, fue de 254 pacientes ingresados en tres hospitales del Servei Valencià de Salut de la provincia de Alicante, mayores de 16 años, conscientes y orientados. Los instrumentos de medida fueron tres escalas de satisfacción, dos de carácter general y una específica con los cuidados de enfermería, todas autoinformes. Los rasgos evaluados fueron varias dimensiones de satisfacción, y los métodos tres tipos de formulación de items y escalas de respuesta. Se ha empleado el análisis factorial confirmatorio, siguiéndose la estrategia de constrastar varios modelos alternativos (Widaman, 1985; Marsh, 1989). Los resulta dos indican que: la varianza de método es elevada, superior a la de rasgos; existe validez convergente; los rasgos están altamente correlacionados, pero hay evidencia de validez discriminante; dos métodos están altamente correlacionados; y no se ha podido estimar el modelo general de matrices MTMM.

Análisis multirrasgo-multimétodo en la validación de instrumentos para la evaluación de la calidad docente en instituciones universitarias.

Se presentan los resultados de un estudio que tiene como objetivo establecer modelos de acción docente eficaz en el nivel universitario. Utiliza técnicas multirrasgo-multimétodo para la evaluación del docente a partir de los cuestionarios realizados a estudiantes, profesores y directores..

Evaluación de la satisfacción del paciente hospitalizado: empleo de una matriz multirrasgo-multimétodo reducida

En esta investigación sobre la satisfacción del paciente con la hospitalización y los cuidados de enfermería se hace uso de la estrategia "matriz multirrasgo-multimétodo". Los sujetos (n=116) fueron personas ingresadas en los hospitales del Servicio Valenciano de Salud de Alicante y Elche. Se midieron dos rasgos: satisfacción con los cuidados de enfermería y satisfacción con la hospitalización. Los métodos fueron: escalas con formato de respuesta "acuerdo-desacuerdo" con clave positiva (AD+), escalas con formato de respuesta "acuerdo-desacuerdo" con clave negativa (AD-), y escalas con formato de respuesta "excelente-malo" (EM). Los tres métodos se manifiestan casi con la misma cantidad de varianza, el método con formato EM aporta mayor fiabilidad, y la covariación entre el formato con clave positiva (AD+) y el formato EM es mayor que cualquier otra combinación.

Una aproximación empírica al estudio del constructo competencia docente del profesor universitario.

Presentar instrumentos para el estudio del constructo competencia docente del profesorado universitario analizando las dimensiones más valiosas de la acción docente. 4109 alumnos-as y 49 profesores-as del Centro Universitario Francisco de Vitoria, asociado a la Universidad Complutense, durante el curso 1994-1995. Se presentan las características del modelo de evaluación institucional aplicado a la muestra y se describen los instrumentos empleados para el estudio del constructo competencia docente del profesorado universitario: Cuestionario de Evaluación Docente (CEDA) y Cuestionario de Autoevaluación Docente (CAD). Se presenta la estructura del CEDA, constituido por seis subescalas en las que se valora la asignatura, la planificación del curso y de la clase, las habilidades didácticas y motivacionales, el modelo evaluativo y el grado de eficacia docente global del profesorado. El CAD está constituido por cinco subescalas en las que se analiza la autoevaluación docente y el nivel de satisfacción con el proyecto del centro, con los medios y recursos disponibles, con el clima y las relaciones interpersonales en el centro y con cada grupo de alumnos. Se realiza un análisis factorial confirmatorio de la estructura del CEDA y un análisis de estructuras de covarianza (modelos estructurales y de medida). A través de análisis de correlación y factores multirrasgo-multimétodo se estudia la validez convergente y discriminante de los instrumentos empleados. Cuestionario de Evaluación Docente por el Alumno (CEDA), Cuestionario de Autoevaluación Docente (CAD). T de Student, porcentajes. Se observa que los instrumentos que valoran la competencia docente del profesorado universitario hacen hincapié en el dominio de la asignatura, los aspectos didáctico-técnicos, la comunicación con el alumnado y los aspectos personales-motivacionales. Se señala que todos estos factores están presentes en el CEDA, afirmando que éste es un instrumento adecuado para la evaluación de la docencia en las aulas y la estimación de indicadores relacionados con ella y el más indicado para la medición del constructo objeto de estudio. Se recomienda complementar el estudio teórico de la competencia docente empleando el análisis discriminante para detectar qué rasgos caracterizan al profesor competente y al no competente. Se precisa la realización de investigaciones sobre las causas de las diferencias entre las valoraciones de los estudiantes.

Los profesores piensan diferente : efectos del método en la evaluación de la inteligencia socio-emocional de alumnos de altas habilidades.

Monográfico con el título: 'Inteligencia emocional y alta habilidad'. Resumen basado en el de la publicación

Krylov subspace methods for approximating functions of symmetric positive definite matrices with applications to applied statistics and anomalous diffusion

Matrix function approximation is a current focus of worldwide interest and finds application in a variety of areas of applied mathematics and statistics. In this thesis we focus on the approximation of A^(-α/2)b, where A ∈ ℝ^(n×n) is a large, sparse symmetric positive definite matrix and b ∈ ℝ^n is a vector. In particular, we will focus on matrix function techniques for sampling from Gaussian Markov random fields in applied statistics and the solution of fractional-in-space partial differential equations. Gaussian Markov random fields (GMRFs) are multivariate normal random variables characterised by a sparse precision (inverse covariance) matrix. GMRFs are popular models in computational spatial statistics as the sparse structure can be exploited, typically through the use of the sparse Cholesky decomposition, to construct fast sampling methods. It is well known, however, that for sufficiently large problems, iterative methods for solving linear systems outperform direct methods. Fractional-in-space partial differential equations arise in models of processes undergoing anomalous diffusion. Unfortunately, as the fractional Laplacian is a non-local operator, numerical methods based on the direct discretisation of these equations typically requires the solution of dense linear systems, which is impractical for fine discretisations. In this thesis, novel applications of Krylov subspace approximations to matrix functions for both of these problems are investigated. Matrix functions arise when sampling from a GMRF by noting that the Cholesky decomposition A = LL^T is, essentially, a `square root' of the precision matrix A. Therefore, we can replace the usual sampling method, which forms x = L^(-T)z, with x = A^(-1/2)z, where z is a vector of independent and identically distributed standard normal random variables. Similarly, the matrix transfer technique can be used to build solutions to the fractional Poisson equation of the form ϕn = A^(-α/2)b, where A is the finite difference approximation to the Laplacian. Hence both applications require the approximation of f(A)b, where f(t) = t^(-α/2) and A is sparse. In this thesis we will compare the Lanczos approximation, the shift-and-invert Lanczos approximation, the extended Krylov subspace method, rational approximations and the restarted Lanczos approximation for approximating matrix functions of this form. A number of new and novel results are presented in this thesis. Firstly, we prove the convergence of the matrix transfer technique for the solution of the fractional Poisson equation and we give conditions by which the finite difference discretisation can be replaced by other methods for discretising the Laplacian. We then investigate a number of methods for approximating matrix functions of the form A^(-α/2)b and investigate stopping criteria for these methods. In particular, we derive a new method for restarting the Lanczos approximation to f(A)b. We then apply these techniques to the problem of sampling from a GMRF and construct a full suite of methods for sampling conditioned on linear constraints and approximating the likelihood. Finally, we consider the problem of sampling from a generalised Matern random field, which combines our techniques for solving fractional-in-space partial differential equations with our method for sampling from GMRFs.

Urban dynamic origin-destination matrices estimation

The aim of this paper is to explore a new approach to obtain better traffic demand (Origin-Destination, OD matrices) for dense urban networks. From reviewing existing methods, from static to dynamic OD matrix evaluation, possible deficiencies in the approach could be identified: traffic assignment details for complex urban network and lacks in dynamic approach. To improve the global process of traffic demand estimation, this paper is focussing on a new methodology to determine dynamic OD matrices for urban areas characterized by complex route choice situation and high level of traffic controls. An iterative bi-level approach will be used, the Lower level (traffic assignment) problem will determine, dynamically, the utilisation of the network by vehicles using heuristic data from mesoscopic traffic simulator and the Upper level (matrix adjustment) problem will proceed to an OD estimation using optimization Kalman filtering technique. In this way, a full dynamic and continuous estimation of the final OD matrix could be obtained. First results of the proposed approach and remarks are presented.

Mineralized human primary osteoblast matrices as a model system to analyse interactions of prostate cancer cells with the bone microenvironment

Prostate cancer metastasis is reliant on the reciprocal interactions between cancer cells and the bone niche/micro-environment. The production of suitable matrices to study metastasis, carcinogenesis and in particular prostate cancer/bone micro-environment interaction has been limited to specific protein matrices or matrix secreted by immortalised cell lines that may have undergone transformation processes altering signaling pathways and modifying gene or receptor expression. We hypothesize that matrices produced by primary human osteoblasts are a suitable means to develop an in vitro model system for bone metastasis research mimicking in vivo conditions. We have used a decellularized matrix secreted from primary human osteoblasts as a model for prostate cancer function in the bone micro-environment. We show that this collagen I rich matrix is of fibrillar appearance, highly mineralized, and contains proteins, such as osteocalcin, osteonectin and osteopontin, and growth factors characteristic of bone extracellular matrix (ECM). LNCaP and PC3 cells grown on this matrix, adhere strongly, proliferate, and express markers consistent with a loss of epithelial phenotype. Moreover, growth of these cells on the matrix is accompanied by the induction of genes associated with attachment, migration, increased invasive potential, Ca2+ signaling and osteolysis. In summary, we show that growth of prostate cancer cells on matrices produced by primary human osteoblasts mimics key features of prostate cancer bone metastases and thus is a suitable model system to study the tumor/bone micro-environment interaction in this disease.

Osteogenic induction of human bone marrow-derived mesenchymal progenitor cells in novel synthetic polymer-hydrogel matrices

The aim of this project was to investigate the in vitro osteogenic potential of human mesenchymal progenitor cells in novel matrix architectures built by means of a three-dimensional bioresorbable synthetic framework in combination with a hydrogel. Human mesenchymal progenitor cells (hMPCs) were isolated from a human bone marrow aspirate by gradient centrifugation. Before in vitro engineering of scaffold-hMPC constructs, the adipogenic and osteogenic differentiation potential was demonstrated by staining of neutral lipids and induction of bone-specific proteins, respectively. After expansion in monolayer cultures, the cells were enzymatically detached and then seeded in combination with a hydrogel into polycaprolactone (PCL) and polycaprolactone-hydroxyapatite (PCL-HA) frameworks. This scaffold design concept is characterized by novel matrix architecture, good mechanical properties, and slow degradation kinetics of the framework and a biomimetic milieu for cell delivery and proliferation. To induce osteogenic differentiation, the specimens were cultured in an osteogenic cell culture medium and were maintained in vitro for 6 weeks. Cellular distribution and viability within three-dimensional hMPC bone grafts were documented by scanning electron microscopy, cell metabolism assays, and confocal laser microscopy. Secretion of the osteogenic marker molecules type I procollagen and osteocalcin was analyzed by semiquantitative immunocytochemistry assays. Alkaline phosphatase activity was visualized by p-nitrophenyl phosphate substrate reaction. During osteogenic stimulation, hMPCs proliferated toward and onto the PCL and PCL-HA scaffold surfaces and metabolic activity increased, reaching a plateau by day 15. The temporal pattern of bone-related marker molecules produced by in vitro tissue-engineered scaffold-cell constructs revealed that hMPCs differentiated better within the biomimetic matrix architecture along the osteogenic lineage.

In vitro characterization of natural and synthetic dermal matrices cultured with human dermal fibroblasts

The ideal dermal matrix should be able to provide the right biological and physical environment to ensure homogenous cell and extracellular matrix (ECM) distribution, as well as the right size and morphology of the neo-tissue required. Four natural and synthetic 3D matrices were evaluated in vitro as dermal matrices, namely (1) equine collagen foam, TissuFleece®, (2) acellular dermal replacement, Alloderm®, (3) knitted poly(lactic-co-glycolic acid) (10:90)–poly(-caprolactone) (PLGA–PCL) mesh, (4) chitosan scaffold. Human dermal fibroblasts were cultured on the specimens over 3 weeks. Cell morphology, distribution and viability were assessed by electron microscopy, histology and confocal laser microscopy. Metabolic activity and DNA synthesis were analysed via MTS metabolic assay and [3H]-thymidine uptake, while ECM protein expression was determined by immunohistochemistry. TissuFleece®, Alloderm® and PLGA–PCL mesh supported cell attachment, proliferation and neo-tissue formation. However, TissuFleece® contracted to 10% of the original size while Alloderm® supported cell proliferation predominantly on the surface of the material. PLGA–PCL mesh promoted more homogenous cell distribution and tissue formation. Chitosan scaffolds did not support cell attachment and proliferation. These results demonstrated that physical characteristics including porosity and mechanical stability to withstand cell contraction forces are important in determining the success of a dermal matrix material.

Engineered silk fibroin protein 3D matrices for in vitro tumor model

3D in vitro model systems that are able to mimic the in vivo microenvironment are now highly sought after in cancer research. Antheraea mylitta silk fibroin protein matrices were investigated as potential biomaterial for in vitro tumor modeling. We compared the characteristics of MDA-MB-231 cells on A. mylitta, Bombyx mori silk matrices, Matrigel, and tissue culture plates. The attachment and morphology of the MDA-MB-231 cell line on A. mylitta silk matrices was found to be better than on B. mori matrices and comparable to Matrigel and tissue culture plates. The cells grown in all 3D cultures showed more MMP-9 activity, indicating a more invasive potential. In comparison to B. mori fibroin, A. mylitta fibroin not only provided better cell adhesion, but also improved cell viability and proliferation. Yield coefficient of glucose consumed to lactate produced by cells on 3D A. mylitta fibroin was found to be similar to that of cancer cells in vivo. LNCaP prostate cancer cells were also cultured on 3D A. mylitta fibroin and they grew as clumps in long term culture. The results indicate that A. mylitta fibroin scaffold can provide an easily manipulated microenvironment system to investigate individual factors such as growth factors and signaling peptides, as well as evaluation of anticancer drugs.