5 research outputs found
Multivariate regression smoothing through the 'fallling net'.
We consider multivariate regression smoothing through a conditional mean shift procedure. By computing local conditional means iteratively over a set or grid of target points, at each iteration a `net' is formed which gently drifts towards the data cloud, until it settles at the conditional modes of the response distribution.
The method is edge-preserving and allows for multi-valued response
Multivariate regression smoothing through the 'fallling net'
We consider multivariate regression smoothing through a conditional mean shift procedure. By computing local conditional means iteratively over a set or grid of target points, at each iteration a `net' is formed which gently drifts towards the data cloud, until it settles at the conditional modes of the response distribution. The method is edge-preserving and allows for multi-valued response
Bayesian assessment of times to diagnosis in breast cancer screening
Breast cancer is one of the diseases with the most profound impact on health in developed countries and mammography is the most popular method for detecting breast cancer at a very early stage. This paper focuses on the waiting period from a positive mammogram until a confirmatory diagnosis is carried out in hospital. Generalized linear mixed models are used to perform the statistical analysis, always within the Bayesian reasoning. Markov chain Monte Carlo algorithms are applied for estimation by simulating the posterior distribution of the parameters and hyperparameters of the model through the free software WinBUGS.Bayesian statistics, breast cancer screening program, generalized linear mixed models, Markov Chain Monte Carlo,
Bayesian spatio-temporal approach to identifying fish nurseries by validating persistence areas
Spatial and temporal closures of fish nursery areas to fishing have recently been recognized as useful tools for efficient fisheries management, as they preserve the reproductive potential of populations and increase the recruitment of target species. In order to identify and locate potential nursery areas for spatio-temporal closures, a solid understanding of species-environment relationships is needed, as well as spatial identification of fish nurseries through the application of robust analyses. One way to achieve knowledge of fish nurseries is to analyse the persistence of recruitment hotspots. In this study, we propose the comparison of different spatio-temporal model structures to assess the persistence of a spatial process. In particular, we apply our approach to a 2-stage Bayesian hierarchical spatio-temporal model that describes both the occurrence and the abundance of European hake Merluccius merluccius recruits in the western Mediterranean Sea. Results clearly show areas of high occurrence and abundance, mainly along the shelf break and the upper slope of the Spanish Mediterranean coast. Understanding the distributional patterns associated with key life stages such as recruitment is essential for appropriate spatial management, including the implementation of Fisheries Restricted Areas and/or Marine Protected Areas that improve the management of fishery resources
Tratamientos Psicológicos Empíricamente Apoyados Para Adultos: Una Revisión Selectiva
Antecedentes: los tratamientos psicológicos han mostrado su efi cacia, efectividad y efi ciencia para el abordaje de los trastornos mentales; no obstante, considerando el conocimiento científi co generado en los últimos años, no se dispone de trabajos de actualización en español sobre cuáles son los tratamientos psicológicos con respaldo empírico. El objetivo fue realizar una revisión selectiva de los principales tratamientos psicológicos empíricamente apoyados para el abordaje de trastornos mentales en personas adultas. Método: se recogen niveles de evidencia y grados de recomendación en función de los criterios propuestos por el Sistema Nacional de Salud de España (en las Guías de Práctica Clínica) para diferentes trastornos psicológicos. Resultados: los resultados sugieren que los tratamientos psicológicos disponen de apoyo empírico para el abordaje de un amplio elenco de trastornos psicológicos. El grado de apoyo empírico oscila de bajo a alto en función del trastorno psicológico analizado. La revisión sugiere que ciertos campos de intervención necesitan una mayor investigación. Conclusiones: a partir de esta revisión selectiva, los profesionales de la psicología podrán disponer de información rigurosa y actualizada que les permita tomar decisiones informadas a la hora de implementar aquellos procedimientos psicoterapéuticos empíricamente fundamentad