Normalizacion del umbral del potencial evocado auditivo troncoencefalico con estimulo tonal en las frecuencias de 500 y 2000 hz para la Clinica Fonoaudiolgica de la Universidad de Talca

48 p.Para el estudio de la función auditiva se considera gold standard la audiometría de tonos puros que permite obtener umbrales auditivos frecuencia específico. Sin embargo, en ocasiones es necesario recurrir a pruebas objetivas, que no precisan de la colaboración del paciente, encontrándose entre ellas los potenciales evocados auditivos troncoencefálicos (PEAT) que permiten conocer la respuesta bioeléctrica ante un estímulo sonoro. El método más utilizado es la estimulación con tono click que entrega una visualización global del estado de la audición, pero se ha fomentado el uso del estímulo tonal que otorga una evaluación auditiva frecuencia específico, que permitiría una implementación auditiva y terapia fonoaudiológica más eficaz. Aún no se han establecido valores normales o de referencia para utilizarse en la práctica clínica por lo cual en el presente estudio se determinaron los umbrales electrofisiológicos para una muestra de 30 sujetos normoyentes, mediante la realización de PEAT con estímulo tonal, a través de la observación del peak de onda V, a 500 y 2000 Hz. Se estableció la relación entre umbrales, obteniéndose una ecuación de regresión para 2000Hz, y así predecir el mbral audiométrico a partir del umbral electrofisiológico en sujetos normoyentes para la Clínica fonoaudiológica de la Universidad de Talca

Assessment of the Performance of Imputation Techniques in Observational Studies with Two Measurements

: In observational studies with two measurements when the measured outcome pertains to a health related quality of life (HRQoL) variable, one motivation of the research may be to determine the potential predictors of the mean change of the outcome of interest. It is very common in such studies for data to be missing, which can bias the results. Different imputation techniques have been proposed to cope with missing data in outcome variables. We compared five analysis approaches (Complete Case, Available Case, K- Nearest Neighbour, Propensity Score, and a Markov Chain Monte Carlo algorithm) to assess their performance when handling missing data at different missingness rates and mechanisms (MCAR, MAR and MNAR). These strategies were applied to a pre-post study of patients with Chronic Obstructive Pulmonary Disease. We analyzed the relationship of the changes in subjects HRQoL over one year with clinical and socio-demographic characteristics. A simulation study was also performed to illustrate the performance of the imputation methods. Relative and standardized bias was assessed on each scenario. For all missingness mechanisms, not imputing and using MCMC method, both combined with mixed-model analysis, showed lowest standardized bias. Conversely, Propensity Score showed worst bias values. When missingness pattern is MCAR or MAR and rate small, we recommend using mixed models. Nevertheless, when missingness percentage is high, in order to gain sample size and statistical power, MCMC is preferred, although there are no bias differences compared with the mixed models without imputation. For a MNAR scenario, a further sensitivity analysis should be made

Normalización del potencial evocado auditivo troncoencefálico con estímulo tonal para la Clínica Fonoaudiológica de la Universidad de Talca

46 p.Para el estudio objetivo de la función auditiva es posible utilizar una serie de pruebas de las cuales los más utilizados son los Potenciales Evocados Auditivos,y en mayor medida aquellos que evalúan la función auditiva a nivel de tronco cerebral. Comúnmente para su aplicación se ha utilizado estímulo banda ancha que permite entregar resultados del estado global de la audición, sin embargo carece de especificidad frecuencial. Para ello se han descrito estímulos frecuencia específicos con la finalidad de establecer umbrales electrofisiológicos mas precisos, dentro de ellos encontramos el estímulo tonal. El presente estudio tiene como objetivo entregar valores normales de umbral y latencias absolutas de onda V a niveles supraumbrales a 500 Hz utilizando estímulo tonal. Los análisis realizados señalan una media de umbral obtenido de 36,5 dB nHL para ambos oídos y latencias absolutas de onda V a 75 dB nHL de 6,55 ms para el oído derecho y de 6,37ms para el oído izquierdo. Los resultados obtenidos entregan información de gran relevancia para el uso de este estímulo en la clínica y dan pie para futuras investigaciones en esta área que permitan entregar valores útiles en el diagnóstico temprano de pérdidas auditivas y su implementación

Aid, Microfinance and income inequality: A global view

This article studies the relationship between foreign aid and microfinance flows and income inequality. Using a broad theoretical framework on inequality, and panel data for 87 countries from 1995 to 2012, we study the dynamics of aid and microfinance and how these relate to income inequality. Our results highlight important differences across world regions and the need to consider specificities of the context when assessing the impact of both aid and microfinance on inequality. In this line, we provide an analysis for three different countries: Bolivia, Bangladesh, and Indonesia

On the development of three new tools for organizing and sharing information in three-dimensional electron microscopy

This work was funded by the Spanish Ministerio de Economía y Competividad through grants BFU2009-09331, BIO2010-16566, ACI2009-1022, ACI2010-1088 and AIC-A- 2011-0638, by the Comunidad Autonoma de Madrid through grant S2010/BMD-2305, by NFS grant No. 1114901 and by the Spanish National Institute of Bioinformatics (a project funded by the Instituto de Salud Carlos III). This work was conducted using the Protégé resource, which is supported by grant LM007885 from the United States National Library of Medicine. COSS is a Ramón y Cajal researcher financed by the European Social Fund and the Ministerio de Economía y Competitividad. JV is a Juan de la Cierva Postdoctoral Fellow (JCI-2011-10185). This work was funded by Instruct, which is part of the European Strategy Forum on Research Infrastructures (ESFRI) and is supported by national member subscriptions

Epidermólisis bullosa en Espa˜na: Estudio observacional de una cohorte de pacientes atendidos en un centro de referencia nacional

Background and objective: Epidermolysis bullosa (EB) is a heterogeneous group of inherited disorders characterized by a high degree of mucocutaneous fragility. This study aimed to describe the clinical and epidemiologic characteristics of patients with EB treated in Hospital Universitario La Paz, a national referral center for inherited EB. Material and methods: Observational, retrospective, single-center study. We included all cases with a clinical and molecular diagnosis of EB managed in the hospital's dermatology department from January 2, 2000, to February 28, 2021. Results: A total of 214 cases were studied. The median (interquartile range) age was 17 (8---32) years; 54.2% were women. One hundred thirty-five (63.1%) patients had dystrophic EB, 67 (31.3%) had EB simplex, 8 (3.7%) had junctional EB, and 3 (1.4%) had Kindler syndrome. One (0.5%) had EB acquisita. Over a third (35.5%) of the patients resided in Madrid. The most common clinical complications were pruritus (63.1%), local infections (56.5%), and pain (54.7%). The most serious ones were cardiomyopathy (in 5.6%) and squamous cell carcinoma (10.3%). Twenty-two patients (10.3%) died

Drosophila melanogaster Models of Metal-Related Human Diseases and Metal Toxicity

Iron, copper and zinc are transition metals essential for life because they are required in a multitude of biological processes. Organisms have evolved to acquire metals from nutrition and to maintain adequate levels of each metal to avoid damaging effects associated with its deficiency, excess or misplacement. Interestingly, the main components of metal homeostatic pathways are conserved, with many orthologues of the human metal-related genes having been identified and characterized in Drosophila melanogaster. Drosophila has gained appreciation as a useful model for studying human diseases, including those caused by mutations in pathways controlling cellular metal homeostasis. Flies have many advantages in the laboratory, such as a short life cycle, easy handling and inexpensive maintenance. Furthermore, they can be raised in a large number. In addition, flies are greatly appreciated because they offer a considerable number of genetic tools to address some of the unresolved questions concerning disease pathology, which in turn could contribute to our understanding of the metal metabolism and homeostasis. This review recapitulates the metabolism of the principal transition metals, namely iron, zinc and copper, in Drosophila and the utility of this organism as an experimental model to explore the role of metal dyshomeostasis in different human diseases. Finally, a summary of the contribution of Drosophila as a model for testing metal toxicity is provided

Drosophila melanogaster models of Friedreich's ataxia

Friedreich's ataxia (FRDA) is a rare inherited recessive disorder affecting the central and peripheral nervous systems and other extraneural organs such as the heart and pancreas. This incapacitating condition usually manifests in childhood or adolescence, exhibits an irreversible progression that confines the patient to a wheelchair, and leads to early death. FRDA is caused by a reduced level of the nuclear-encoded mitochondrial protein frataxin due to an abnormal GAA triplet repeat expansion in the first intron of the human FXN gene. FXN is evolutionarily conserved,with orthologs in essentially all eukaryotes and some prokaryotes, leading to the development of experimental models of this disease in different organisms.These FRDA models have contributed substantially to our current knowledge of frataxin function and the pathogenesis of the disease, as well as to explorations of suitable treatments. Drosophila melanogaster, an organism that is easy to manipulate genetically, has also become important in FRDA research. This review describes the substantial contribution of Drosophila to FRDA research since the characterization of the fly frataxin ortholog more than 15 years ago. Fly models have provided a comprehensive characterization of the defects associatedwith frataxin deficiency and have revealed genetic modifiers of disease phenotypes. In addition, these models are now being used in the search for potential therapeutic compounds for the treatment of this severe and still incurable disease

Agrupamiento conceptual jerárquico basado en distancias

En este trabajo de investigación analizamos la relación existente entre el agrupamiento jerárquico basado en distancia y los conceptos que se pueden inducir por generalización a partir de una jerarquía, mostrando que pueden surgir diversas inconsistencias a partir de incompatibilidades entre las distancias subyacentes y los operadores de generalización empleados. En este contexto, hemos definido un marco teórico genérico en el cual, por un lado, hemos propuesto un nuevo algoritmo de agrupamiento en el que integramos el agrupamiento jerárquico basado en distancias y el agrupamiento conceptual, permitiendo observar en las nuevas jerarquías obtenidas si un elemento ha sido integrado a un grupo por la distancia de enlazado o porque se encuentra cubierto por el concepto asociado al grupo. Por otro lado, hemos definido tres niveles diferentes de consistencia entre los operadores de generalización y las distancias a partir de la similitud existente entre las nuevas jerarquías conseguidas con nuestro algoritmo y las correspondientes obtenidas por el algoritmo tradicional jerárquico. Actualmente, nos encontramos trabajando en el análisis de diversas instanciaciones del marco teórico genérico antes mencionado.Eje: Agentes y sistemas inteligentesRed de Universidades con Carreras en Informática (RedUNCI

An instantiation for sequences of hierarchical distance-based conceptual clustering

In this work, we present an instantiation of our framework for Hierarchical Distance-based Conceptual Clustering (HDCC) using sequences, a particular kind of structured data. We analyze the relationship between distances and generalization operators for sequences in the context of HDCC. HDCC is a general approach to conceptual clustering that extends the traditional algorithm for hierarchical clustering by producing conceptual generalizations of the discovered clusters. Since the approach is general, it allows combining the flexibility of changing distances for different data types at the same time that we take advantage of the interpretability offered by the obtained concepts, which is central for descriptive data mining tasks. We propose here different generalization operators for sequences and analyze how they work together with the edit and linkage distances in HDCC. This analysis is carried out based on three different properties for generalization operators and three different levels of agreement between the clustering hierarchy obtained from the linkage distance and the hierarchy obtained by using generalization operators.Sociedad Argentina de Informática e Investigación Operativ