Choice of a Survival Model for Patients With a Brain Tumour.
Classification of cancer recurrence with alpha-beta BAM.
Classification of Images Background Subtraction in Image Segmentation
Many image segmentation algorithms have been proposed to partition an image into foreground regions of interest and background regions to be ignored. These algorithms use pixel intensities to partition the image, so it should be good practice to choose an appropriate background color as different as possible from the foreground one. In the case of a unique digitizing operation the user can make the choice of background color by himself in order to obtain a good result in the segmentation process,...
Classification of Smoking Cessation Status Using Various Data Mining Methods
AMS Subj. Classification: 62P10, 62H30, 68T01This study examines different approaches of binary classification applied to the prob- lem of making distinction between former and current smokers. Prediction is based on data collected in national survey performed by the National center for health statistics of America in 2000. The process consists of two essential parts. The first one determines which attributes are relevant to smokers status, by using methods like basic genetic algorithm and different evaluation...
Comparing the suitability of two factors for stratification in estimating diversity
Compartmental Models of Migratory Dynamics
Compartmentalization is a general principle in biological systems which is observable on all size scales, ranging from organelles inside of cells, cells in histology, and up to the level of groups, herds, swarms, meta-populations, and populations. Compartmental models are often used to model such phenomena, but such models can be both highly nonlinear and difficult to work with.Fortunately, there are many significant biological systems that are amenable to linear compartmental models which are often...
Comportement optimum dans un test Q. C. M.
Concatenación temporal de modelos espaciales y su aplicación al estudio de la meningitis en España.
La cartografía de enfermedades infecciosas en periodos sucesivos plantea la necesidad de su extensión al caso dinámico. En este trabajo proponemos la concatenación temporal de modelos auto-regresivos espaciales para abordar el análisis de mortalidad por meningitis en España en el período 1950-1990 con datos agregados a nivel provincial. Para la estimación v selección del modelo usamos técnicas basadas en la función de verosimilitud.
Contribution à l'étude du modèle âge-période-cohorte
Could condom stop the AIDS epidemic?
Cumulative processes related to event histories.
Costs or benefits which accumulate for individuals over time are of interest in many life history processes. Familiar examples include costs of health care for persons with chronic medical conditions, the payments to insured persons during periods of disability, and quality of life which is sometimes used in the evaluation of treatments in terminally ill patients. For convenience, here we use the term costs to refer to cost or other cumulative measures. Two important scenarios are (i) where costs...
Diagnostics of the AML with immunophenotypical data
Patients with acute myeloblastic leukemia (AML) are divided according to the French American British (FAB) classification into eight subgroups (M0 to M7) on the basis of their degree of maturation/differentiation. However, even if immunophenotypical characterization by flow cytometry is routinely used to distinguish between AML and acute lymphoblastic leukemia (ALL), it is not yet well established for the identification within the AML subgroups. Here we show that certain subgroups of AML can be...
Effect of allocated radiotherapy after breast surgeries over death risk in early breast cancer patients: a meta-analysis.
El problema de Beherens-Fisher en la investigación biomédica. Análisis crítico de un estudio clínico mediante simulación.
En el artículo se hace una revisión del problema de Behrens-Fisher, discutiendo los fundamentos inferenciales asociados a la dificultad de su resolución y exponiendo las soluciones prácticas más comunes, juntamente con una nueva solución basada en conceptos de geometría diferencial. A continuación, se realiza un estudio crítico de una investigación biomédica en donde las verdaderas probabilidades de error son distintas de las supuestas debido a que se ignoran probables diferencias entre las varianzas....
Epidemics with two levels of mixing: The exact moments.
Estimating a resource selection function with line transect sampling.
Estimation of Fish Population Size by Single Marking and Recapture Method
Estimation of the Parameter of the Inverse Gaussian Distribution from Generalised Censored Samples.
Estudios de supervivencia con datos no observados. Dificultades inherentes al enfoque paramétrico.
A partir de una muestra de datos de supervivencia que contiene valores no observados en las covariantes de interés, presentamos una metodología que permite extraer toda la información contenida en covariantes completamente observadas, que estén fuertemente correlacionadas con las citadas covariantes de interés. El enfoque utilizado es completamente paramétrico y se basa en el método de máxima verosimilitud. Mostramos las dificultades, tanto de índole práctica como filosófica, que aparecen en la...
Finiteness results for Abelian tree models
Equivariant tree models are statistical models used in the reconstruction of phylogenetic trees from genetic data. Here equivariant§ refers to a symmetry group imposed on the root distribution and on the transition matrices in the model. We prove that if that symmetry group is Abelian, then the Zariski closures of these models are defined by polynomial equations of bounded degree, independent of the tree. Moreover, we show that there exists a polynomial-time membership test for that Zariski closure....