Consistency of Bayesian procedures for variable selection

It has long been known that for the comparison of pairwise nested models, a decision based on the Bayes factor produces a consistent model selector (in the frequentist sense). Here we go beyond the usual consistency for nested pairwise models, and show that for a wide class of prior distributions, including intrinsic priors, the corresponding Bayesian procedure for variable selection in normal regression is consistent in the entire class of normal linear models. We find that the asymptotics of the Bayes factors for intrinsic priors are equivalent to those of the Schwarz (BIC) criterion. Also, recall that the Jeffreys--Lindley paradox refers to the well-known fact that a point null hypothesis on the normal mean parameter is always accepted when the variance of the conjugate prior goes to infinity. This implies that some limiting forms of proper prior distributions are not necessarily suitable for testing problems. Intrinsic priors are limits of proper prior distributions, and for finite sample sizes they have been proved to behave extremely well for variable selection in regression; a consequence of our results is that for intrinsic priors Lindley's paradox does not arise.Comment: Published in at http://dx.doi.org/10.1214/08-AOS606 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Estudio de las características físicas de haces de fibra de guadua angustifolia

En este artículo se presentan los resultados obtenidos del estudio de características físicas de haces de fibra de Guadua angustifolia , tales como: porcentaje de contenido de humedad, porcentaje de absorción de agua, densidad aparente promedio, forma de la sección transversal y textura superficial. Esta caracterización se hizo con el fin de comparar los resultados obtenidos con características similares de otras fibras naturales y sintéticas y evaluar la factibilidad de utilizar los haces de fibra estudiados como posible material de refuerzo de materiales compuestos. Para lograr este objetivo fue necesario utilizar diferentes técnicas de caracterización de materiales sencillas y sofisticada

Interaction between IRF6 and TGFA Genes Contribute to the Risk of Nonsyndromic Cleft Lip/Palate

Previous evidence from tooth agenesis studies suggested IRF6 and TGFA interact. Since tooth agenesis is commonly found in individuals with cleft lip/palate (CL/P), we used four large cohorts to evaluate if IRF6 and TGFA interaction contributes to CL/P. Markers within and flanking IRF6 and TGFA genes were tested using Taqman or SYBR green chemistries for case-control analyses in 1,000 Brazilian individuals. We looked for evidence of gene-gene interaction between IRF6 and TGFA by testing if markers associated with CL/P were overtransmitted together in the case-control Brazilian dataset and in the additional family datasets. Genotypes for an additional 142 case-parent trios from South America drawn from the Latin American Collaborative Study of Congenital Malformations (ECLAMC), 154 cases from Latvia, and 8,717 individuals from several cohorts were available for replication of tests for interaction. Tgfa and Irf6 expression at critical stages during palatogenesis was analyzed in wild type and Irf6 knockout mice. Markers in and near IRF6 and TGFA were associated with CL/P in the Brazilian cohort (p<10-6). IRF6 was also associated with cleft palate (CP) with impaction of permanent teeth (p<10-6). Statistical evidence of interaction between IRF6 and TGFA was found in all data sets (p = 0.013 for Brazilians; p = 0.046 for ECLAMC; p = 10-6 for Latvians, and p = 0.003 for the 8,717 individuals). Tgfa was not expressed in the palatal tissues of Irf6 knockout mice. IRF6 and TGFA contribute to subsets of CL/P with specific dental anomalies. Moreover, this potential IRF6-TGFA interaction may account for as much as 1% to 10% of CL/P cases. The Irf6-knockout model further supports the evidence of IRF6-TGFA interaction found in humans. © 2012 Letra et al

A Digital Predistortion Technique Based on a NARX Network to Linearize GaN Class F Power Amplifiers (poster)

This work presents a novel Digital Predistortion (DPD) scheme based on a NARX network, suitable for linearizing power amplifiers (PAs). The NARX network is a Recurrent Neural Network (RNN) with embedded memory that allows efficient modeling of nonlinear systems. Its neural architecture is very effective to model long term dependencies, such as the typical memory effects of PAs. To demonstrate the feasibility of the NARX network as a DPD system, a GaN class F PA with two LTE signals with 5 MHz of bandwidth is used. Experimental results show a distortion correction better than 10 dB

Maternal underweight and obesity and risk of orofacial clefts in a large international consortium of population-based studies

Background: Evidence on association of maternal pre-pregnancy weight with risk of orofacial clefts is inconsistent

Aspergilosis pulmonar invasiva: reporte de un caso

The fungus Aspergillus spp. causes infections in immunocompromised hosts and produces a variety of clinical syndromes including lung tracheobronchial, chronic necrotizing pulmonary and allergic bronchopulmonary manifestations, as well as aspergilloma, depending on the type of host-fungus relationship involved. Aspergilloma is usually colonized by Aspergillus spp. lesions in the bronchial tree, while invasive forms are characterized by the presence of hyphae below its basement membrane. The objective of the present study was to describe the case of a pediatric patient with invasive pulmonary aspergillosis in the form of pseudomembranous tracheobronchitis, including the clinical course, diagnostic approach and paraclinical care provided.The patient was a 5-year-old female with a history of Fanconi anemia who presented with febrile neutropenia and pneumonia. Antibiotic treatment with cefepime provided no improvement in the patient’s condition and computed tomography of the thorax revealed bibasilar pulmonary opacities. Bronchoalveolar lavage and a lesion biopsy were performed after diagnostic bronchoscopy showed a white exophytic lesion. Since pathologic examination revealed numerous septate fungal hyphae exhibiting 45° branching compatible with Aspergillus spp., the patient was treated with voriconazole. Bronchoalveolar lavage culture produced fungi of the Aspergillus flavi complex. A review of pulmonary Aspergillus spp. infection in children is also included, with emphasis on the management and treatment of clinical syndromes. In pediatric patients with hematological diseases who present with febrile neutropenia and respiratory symptoms, it is essential to consider fungi as potential etiologic agents including Aspergillus spp., which is common and causes a variety of clinical syndromes. El hongo Aspergillus spp. causa infecciones oportunistas en huéspedes inmunocomprometidos. Cursa con una variedad de síndromes clínicos en el pulmón, que incluyen aspergilosis invasiva, aspergilosis pulmonar necrótica crónica, aspergilosis broncopulmonar alérgica y aspergiloma, cuya manifestación depende del tipo de relación con el huésped. El aspergiloma resulta de lesiones colonizadas por Aspergillus spp. en el árbol bronquial, en tanto que las formas invasivas se caracterizan por la presencia de hifas por debajo de la membrana basal del árbol bronquial.El objetivo de este trabajo es describir el caso de una paciente con aspergilosis pulmonar invasiva en su forma de traqueobronquitis seudomembranosa, considerando el curso clínico, el diagnóstico y el manejo paraclínico.Se trató de una paciente de cinco años de edad con antecedentes de anemia de Fanconi, que fue llevada a consulta con neutropenia febril y neumonía. Se inició el tratamiento antibiótico con cefepime, sin mejoría clínica.La tomografía computadorizada (TC) de tórax reveló opacidades parenquimatosas en ambas bases pulmonares. En una fibrobroncoscopia se encontró una lesión exofítica blanquecina en el bronquio principal derecho, que se sometió a biopsia, y se practicó un lavado broncoalveolar. En el examen de histopatología se hallaron hifas tabicadas a 45°, y el resultado del cultivo reveló la presencia del complejo Aspergillus flavi, por lo que se inició la administración de voriconazol. Se revisaron los reportes en la literatura científica sobre la infección pulmonar por Aspergillus spp. en niños, con énfasis en los síndromes clínicos, y en su manejo y tratamiento.Ante la presencia de síntomas respiratorios en pacientes pediátricos con enfermedades hematológicas que cursen con neutropenia febril, es indispensable considerar como agentes etiológicos los hongos, entre los cuales Aspergillus spp. se presenta frecuentemente causando diferentes síndromes clínicos

Dental anomaly detection using intraoral photos via deep learning

Children with orofacial clefting (OFC) present with a wide range of dental anomalies. Identifying these anomalies is vital to understand their etiology and to discern the complex phenotypic spectrum of OFC. Such anomalies are currently identified using intra-oral exams by dentists, a costly and time-consuming process. We claim that automating the process of anomaly detection using deep neural networks (DNNs) could increase efficiency and provide reliable anomaly detection while potentially increasing the speed of research discovery. This study characterizes the use of` DNNs to identify dental anomalies by training a DNN model using intraoral photographs from the largest international cohort to date of children with nonsyndromic OFC and controls (OFC1). In this project, the intraoral images were submitted to a Convolutional Neural Network model to perform multi-label multi-class classification of 10 dental anomalies. The network predicts whether an individual exhibits any of the 10 anomalies and can do so significantly faster than a human rater can. For all but three anomalies, F1 scores suggest that our model performs competitively at anomaly detection when compared to a dentist with 8 years of clinical experience. In addition, we use saliency maps to provide a post-hoc interpretation for our model’s predictions. This enables dentists to examine and verify our model’s predictions.Fil: Ragodos, Ronilo. University of Iowa; Estados UnidosFil: Wang, Tong. University of Iowa; Estados UnidosFil: Padilla, Carmencita. University of the Philippines; FilipinasFil: Hecht, Jacqueline T.. University of Texas Health Science Center at Houston; Estados UnidosFil: Poletta, Fernando Adrián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Orioli, Ieda Maria. Universidade Federal do Rio de Janeiro; BrasilFil: Buxó, Carmen J.. Universidad de Puerto Rico; Puerto RicoFil: Butali, Azeez. University of Iowa; Estados UnidosFil: Valencia Ramirez, Consuelo. Fundación Clínica Noel; ColombiaFil: Restrepo Muñeton, Claudia. Fundación Clínica Noel; ColombiaFil: Wehby, George. University of Iowa; Estados UnidosFil: Weinberg, Seth M.. University of Pittsburgh; Estados Unidos. University of Pittsburgh at Johnstown; Estados UnidosFil: Marazita, Mary L.. University of Pittsburgh at Johnstown; Estados Unidos. University of Pittsburgh; Estados UnidosFil: Moreno Uribe, Lina M.. University of Iowa; Estados UnidosFil: Howe, Brian J.. University of Iowa; Estados Unido

SNPs associated with testosterone levels influence human facial morphology

Many factors influence human facial morphology, including genetics, age, nutrition, biomechanical forces, and endocrine factors. Moreover, facial features clearly differ between males and females, and these differences are driven primarily by the influence of sex hormones during growth and development. Specific genetic variants are known to influence circulating sex hormone levels in humans, which we hypothesize, in turn, affect facial features. In this study, we investigated the effects of testosterone-related genetic variants on facial morphology. We tested 32 genetic variants across 22 candidate genes related to levels of testosterone, sex hormone-binding globulin (SHGB) and dehydroepiandrosterone sulfate (DHEAS) in three cohorts of healthy individuals for which 3D facial surface images were available (Pittsburgh 3DFN, Penn State and ALSPAC cohorts; total n = 7418). Facial shape was described using a recently developed extension of the dense-surface correspondence approach, in which the 3D facial surface was partitioned into a set of 63 hierarchically organized modules. Each variant was tested against each of the facial surface modules in a multivariate genetic association-testing framework and meta-analyzed. Additionally, the association between these candidate SNPs and five facial ratios was investigated in the Pittsburgh 3DFN cohort. Two significant associations involving intronic variants of SHBG were found: both rs12150660 (p = 1.07E-07) and rs1799941 (p = 6.15E-06) showed an effect on mandible shape. Rs8023580 (an intronic variant of NR2F2-AS1) showed an association with the total and upper facial width to height ratios (p = 9.61E-04 and p = 7.35E-04, respectively). These results indicate that testosterone-related genetic variants affect normal-range facial morphology, and in particular, facial features known to exhibit strong sexual dimorphism in humans

A neurodegenerative disease landscape of rare mutations in Colombia due to founder effects

Background The Colombian population, as well as those in other Latin American regions, arose from a recent tri-continental admixture among Native Americans, Spanish invaders, and enslaved Africans, all of whom passed through a population bottleneck due to widespread infectious diseases that left small isolated local settlements. As a result, the current population reflects multiple founder effects derived from diverse ancestries. Methods We characterized the role of admixture and founder effects on the origination of the mutational landscape that led to neurodegenerative disorders under these historical circumstances. Genomes from 900 Colombian individuals with Alzheimer’s disease (AD) [n = 376], frontotemporal lobar degeneration-motor neuron disease continuum (FTLD-MND) [n = 197], early-onset dementia not otherwise specified (EOD) [n = 73], and healthy participants [n = 254] were analyzed. We examined their global and local ancestry proportions and screened this cohort for deleterious variants in disease-causing and risk-conferring genes. Results We identified 21 pathogenic variants in AD-FTLD related genes, and PSEN1 harbored the majority (11 pathogenic variants). Variants were identified from all three continental ancestries. TREM2 heterozygous and homozygous variants were the most common among AD risk genes (102 carriers), a point of interest because the disease risk conferred by these variants differed according to ancestry. Several gene variants that have a known association with MND in European populations had FTLD phenotypes on a Native American haplotype. Consistent with founder effects, identity by descent among carriers of the same variant was frequent. Conclusions Colombian demography with multiple mini-bottlenecks probably enhanced the detection of founder events and left a proportionally higher frequency of rare variants derived from the ancestral populations. These findings demonstrate the role of genomically defined ancestry in phenotypic disease expression, a phenotypic range of different rare mutations in the same gene, and further emphasize the importance of inclusiveness in genetic studies.Q2Q2Antecedentes La población colombiana, así como la de otras regiones latinoamericanas, surgió de una mezcla tricontinental reciente entre los nativos americanos, los invasores españoles y los africanos esclavizados, todos los cuales pasaron por un cuello de botella poblacional debido a enfermedades infecciosas generalizadas que dejaron a pequeños aislados. asentamientos locales. Como resultado, la población actual refleja múltiples efectos fundadores derivados de diversas ascendencias. Métodos Caracterizamos el papel de la mezcla y los efectos fundadores en el origen del paisaje mutacional que condujo a trastornos neurodegenerativos en estas circunstancias históricas. Genomas de 900 individuos colombianos con enfermedad de Alzheimer (EA) [n = 376], continuo degeneración lobar frontotemporal-enfermedad de la motoneurona (FTLD-MND) [n = 197], demencia de inicio temprano no especificada (EOD) [n = 73 ], y participantes sanos [n = 254] fueron analizados. Examinamos sus proporciones de ascendencia global y local y examinamos esta cohorte en busca de variantes nocivas en los genes que causan enfermedades y confieren riesgos. Resultados Identificamos 21 variantes patogénicas en genes relacionados con AD-FTLD, y PSEN1 albergaba la mayoría (11 variantes patogénicas). Se identificaron variantes de las tres ascendencias continentales. Las variantes heterocigotas y homocigotas de TREM2 fueron las más comunes entre los genes de riesgo de EA (102 portadores), un punto de interés porque el riesgo de enfermedad conferido por estas variantes difería según la ascendencia. Varias variantes genéticas que tienen una asociación conocida con MND en poblaciones europeas tenían fenotipos FTLD en un haplotipo nativo americano. De acuerdo con los efectos del fundador, la identidad por descendencia entre portadores de la misma variante fue frecuente. Conclusiones La demografía colombiana con múltiples mini-cuellos de botella probablemente mejoró la detección de eventos fundadores y dejó una frecuencia proporcionalmente más alta de variantes raras derivadas de las poblaciones ancestrales. Estos hallazgos demuestran el papel de la ascendencia definida genómicamente en la expresión fenotípica de la enfermedad, un rango fenotípico de diferentes mutaciones raras en el mismo gen, y enfatizan aún más la importancia de la inclusión en los estudios genéticos.https://orcid.org/0000-0001-6529-7077https://scholar.google.com/citations?hl=es&user=kaGongoAAAAJ&view_op=list_works&sortby=pubdatehttps://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0000055000&lang=esRevista Internacional - Indexad