1000 resultados para Mundó, Carles


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Aquest estudi pretén aprofundir, mitjançant tècniques de neuroimatge, en la cerca de diferències volumètriques, tant en volum de substància gris com blanca, que presenten els pacients de trastorns de personalitat esquizoide i esquizotípic amb relació amb un grup control.

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The Aitchison vector space structure for the simplex is generalized to a Hilbert space structure A2(P) for distributions and likelihoods on arbitrary spaces. Centralnotations of statistics, such as Information or Likelihood, can be identified in the algebraical structure of A2(P) and their corresponding notions in compositional data analysis, such as Aitchison distance or centered log ratio transform.In this way very elaborated aspects of mathematical statistics can be understoodeasily in the light of a simple vector space structure and of compositional data analysis. E.g. combination of statistical information such as Bayesian updating,combination of likelihood and robust M-estimation functions are simple additions/perturbations in A2(Pprior). Weighting observations corresponds to a weightedaddition of the corresponding evidence.Likelihood based statistics for general exponential families turns out to have aparticularly easy interpretation in terms of A2(P). Regular exponential families formfinite dimensional linear subspaces of A2(P) and they correspond to finite dimensionalsubspaces formed by their posterior in the dual information space A2(Pprior).The Aitchison norm can identified with mean Fisher information. The closing constant itself is identified with a generalization of the cummulant function and shown to be Kullback Leiblers directed information. Fisher information is the local geometry of the manifold induced by the A2(P) derivative of the Kullback Leibler information and the space A2(P) can therefore be seen as the tangential geometry of statistical inference at the distribution P.The discussion of A2(P) valued random variables, such as estimation functionsor likelihoods, give a further interpretation of Fisher information as the expected squared norm of evidence and a scale free understanding of unbiased reasoning

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One of the disadvantages of old age is that there is more past than future: this,however, may be turned into an advantage if the wealth of experience and, hopefully,wisdom gained in the past can be reflected upon and throw some light on possiblefuture trends. To an extent, then, this talk is necessarily personal, certainly nostalgic,but also self critical and inquisitive about our understanding of the discipline ofstatistics. A number of almost philosophical themes will run through the talk: searchfor appropriate modelling in relation to the real problem envisaged, emphasis onsensible balances between simplicity and complexity, the relative roles of theory andpractice, the nature of communication of inferential ideas to the statistical layman, theinter-related roles of teaching, consultation and research. A list of keywords might be:identification of sample space and its mathematical structure, choices betweentransform and stay, the role of parametric modelling, the role of a sample spacemetric, the underused hypothesis lattice, the nature of compositional change,particularly in relation to the modelling of processes. While the main theme will berelevance to compositional data analysis we shall point to substantial implications forgeneral multivariate analysis arising from experience of the development ofcompositional data analysis…

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Modern methods of compositional data analysis are not well known in biomedical research.Moreover, there appear to be few mathematical and statistical researchersworking on compositional biomedical problems. Like the earth and environmental sciences,biomedicine has many problems in which the relevant scienti c information isencoded in the relative abundance of key species or categories. I introduce three problemsin cancer research in which analysis of compositions plays an important role. Theproblems involve 1) the classi cation of serum proteomic pro les for early detection oflung cancer, 2) inference of the relative amounts of di erent tissue types in a diagnostictumor biopsy, and 3) the subcellular localization of the BRCA1 protein, and it'srole in breast cancer patient prognosis. For each of these problems I outline a partialsolution. However, none of these problems is \solved". I attempt to identify areas inwhich additional statistical development is needed with the hope of encouraging morecompositional data analysts to become involved in biomedical research

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El càncer colorectal és un dels càncers més comuns i amb major prevalença, presentant una supervivència als 5 anys per sota del 20% sense tractament. Existeixen estudis que demostren que les mutacions en k-ras, present en el 40-50% de càncers colorectals, s’han convertit en marcadors de pronòstic i en factors predictius de manca de resposta a fàrmacs biològics com Cetuximab® o Panitumumab®. Hem analitzat la mutació de KRAS en la nostra sèrie de 60 pacients afectes de càncer colorectal metastàtic candidats a primera línia de tractament. Aquesta mutació estava present en un 41.6%. En el moment del diagnòstic, presentaven malaltia metastàtica sincrònica el 56.6%. De tots ells, un 51.6% va rebre una combinació de quimioteràpia i anticòs monoclonal. En quant a la resposta obtinguda, el control de malaltia va arribar fins el 86.7% en el global de la sèrie. La supervivència lliure de progressió en la nostra sèrie va ser de 11.74 mesos. En pacients amb KRAS natural va ser de 12,59 mesos vs 11.25 mesos en pacients amb KRAS mutat sense observar diferències estadísticament significatives (p=0.958). No es van observar diferències significatives en funció del règim de quimioteràpia administrada, independentment de l’estat de KRAS. La supervivència global va ser de 32,16 mesos. En pacients amb KRAS natural va ser de 32,59 mesos vs. 28 mesos en pacients amb KRAS mutat sense observar diferències estadísticament significatives (p=0.915). La limitació que significa un número petit de pacients, dins una sèrie assistencial, ens ha de fer ser cautelosos en quant a la valoració dels resultats .

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OBJECTIVE: The objective of this study was to compare the frequency of risk behaviors and to measure the extent of co-occurrence of these behaviors in chronically ill and healthy adolescents. METHODS: Data were drawn from the 2002 Swiss Multicenter Adolescent Survey on Health database, a nationally representative survey of 7548 adolescents in postmandatory school aged 16 to 20 years. There were 760 subjects who reported a chronic illness and/or a disability. The comparison group consisted of 6493 subjects who answered negatively to both questions. We defined 8 risk behaviors: daily smoking, alcohol misuse, current cannabis use, current use of any other illegal drug, early sexual debut, eating disorder, violent acts, and antisocial acts. We analyzed each behavior and the sum of behaviors, controlling for age, gender, academic track, parents' education level, depression, and health status. Results are given as adjusted odds ratios using the comparison group as the reference category. RESULTS: Youth with a chronic condition were more likely to smoke daily, to be current cannabis users, and to have performed violent or antisocial acts. Youth with a chronic condition were also more likely to report 3 or >or=4 risk behaviors. CONCLUSIONS: These results indicate that having a chronic condition carries additional risks for engaging in health risk behaviors and emphasize the importance of health risk screening and preventive counseling for young people in general and among those suffering from chronic conditions in particular.

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Fa uns anys un grup de professors del departament d’Informàtica i Matemàtica Aplicada de la Universitat de Girona va decidir endinsar-se al món de l’ensenyament a través d’Internet (e-learning). D’aquí va néixer el projecte ACME (Avaluació Continuada i Millora de l’Ensenyament). Inicialment l’ACME anava dirigit a reduir l’elevat fracàs dels alumnes a les assignatures de matemàtiques. El resultat va ser tan bo que es va ampliar a altrescamps d’estudi com la química o la informàtica, amb tot i això encara hi ha moltes matèries a les quals no dóna suport. Aquest Projecte Final de Carrera neix per donar suport a un nou tipus de problemes dins de la plataforma ACME, els autòmats finits. Aquest nou mòdul inclourà les eines necessàries per poder generar diferents tipus de problemes sobre autòmats finits i la seva posterior correcció, donant suport a les assignatures de LGA (Llenguatges, Gramàtiques i Autòmats) i TALLF (Teoria d’Autòmats i Llenguatges Formals)

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The aim of this study was to assess the expectations of adolescents with chronic disorders with regard to transition from pediatric to adult health care and to compare them with the expectations of their parents. A cross-sectional study was carried out including 283 adolescents with chronic disorders, aged 14-25 years (median age, 16.0 years), and not yet transferred to adult health care, and their 318 parents from two university children's hospitals. The majority of adolescents and parents (64%/70%) perceived the ages of 18-19 years and older as the best time to transfer to adult health care. Chronological age and feeling too old to see a pediatrician were reported as the most important decision factors for the transfer while the severity of the disease was not considered important. The most relevant barriers were feeling at ease with the pediatrician (45%/38%), anxiety (20%/24%), and lack of information about the adult specialist and health care (18%/27%). Of the 51% of adolescents with whom the pediatric specialist had spoken about the transfer, 53% of adolescents and 69% of parents preferred a joint transfer meeting with the pediatric and adult specialist, and 24% of these adolescents declared that their health professional had offered this option. In summary, the age preference for adolescents with chronic disorders and their parents to transfer to adult health care was higher than the upper age limits for admission to pediatric health care in many European countries. Anxiety and a lack of information of both adolescents and their parents were among the most important barriers for a smooth and timely transfer according to adolescents and parents.

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El treball analitza la representació de l'Orient a la historieta gràfica, i d'una manera més especifica la imatge dels àrabs i els musulmans. La recerca demostra que els estereotips creats durant l'expansió europea dels segles XVIII i XIX, per l'orientalisme, han estat vigents i formant part de l'imaginari popular durant gairebé dos cents anys. La idisioncràsia popular de la historieta gràfica ha fet que aquests estereotips hagin influenciat la seva narrativa. El nou panorama social i polítc fruit, entre d’altres, del fenomen migratori de la última dècada del segle XX i l'aparició en escena del terrorisme integrista han comportat una transformació dels vells estereotips de l'orientalisme

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La crisis de la prensa escrita está provocada por el impacto de Internet, los errores estratégicos y la Gran Recesión. Pero existe una cuarta razón: una crisis de confianza y credibilidad provocada, a su vez, por una crisis ética. Por consiguiente las alternativas pasan también por una regeneración ética, por una ‘reconstrucción’ del periodism