171 research outputs found
Análisis actuarial del fondo de jubilación de los empleados civiles de la comisión de tránsito de la provincia del Guayas
El presente estudio tiene por objeto analizar la situación financiera actual del Fondo de Jubilación de los empleados civiles de la Comisión de Tránsito de la Provincia del Guayas. No sin antes, describir los sistemas de pensiones públicos y privados y la aplicación de los mismos, en diferentes países de América, incluyendo al Ecuador y los aspectos legales que sustentan la seguridad pública social en dicho país. Así mismo, se ofrece un marco teórico actuarial de los modelos de pensiones y se muestra cómo llegar a determinar el balance actuarial de un Fondo. En nuestro caso, se analiza primeramente la situación demográfica del recurso humano de la institución, aspectos tales como: la distribución de las edades, sueldos y carga familiar de los empleados, Además, se trata de determinar una tabla interna de ocupación laboral y el futuro crecimiento del recurso humano de la Comisión de Tránsito de la Provincia del Guayas. Finalmente, los resultados de la evaluación realizada al Fondo de Jubilación muestran que el mismo se encuentra desfinanciado, por lo que es necesario el estudio de diversas posibilidades de reforma. En consecuencia, se plantea en el estudio, un programa alternativo que pueda cumplir con las obligaciones del Fondo plenamente y que al mismo tiempo ofrezca mejores pensiones a los actuales y futuros jubilados
Nonparametric Bayesian inference for perturbed and orthologous gene regulatory networks
Motivation: The generation of time series transcriptomic datasets collected under multiple experimental conditions has proven to be a powerful approach for disentangling complex biological processes, allowing for the reverse engineering of gene regulatory networks (GRNs). Most methods for reverse engineering GRNs from multiple datasets assume that each of the time series were generated from networks with identical topology. In this study, we outline a hierarchical, non-parametric Bayesian approach for reverse engineering GRNs using multiple time series that can be applied in a number of novel situations including: (i) where different, but overlapping sets of transcription factors are expected to bind in the different experimental conditions; that is, where switching events could potentially arise under the different treatments and (ii) for inference in evolutionary related species in which orthologous GRNs exist. More generally, the method can be used to identify context-specific regulation by leveraging time series gene expression data alongside methods that can identify putative lists of transcription factors or transcription factor targets.
Results: The hierarchical inference outperforms related (but non-hierarchical) approaches when the networks used to generate the data were identical, and performs comparably even when the networks used to generate data were independent. The method was subsequently used alongside yeast one hybrid and microarray time series data to infer potential transcriptional switches in Arabidopsis thaliana response to stress. The results confirm previous biological studies and allow for additional insights into gene regulation under various abiotic stresses.
Availability: The methods outlined in this article have been implemented in Matlab and are available on request
Arquivos para quem? : estudo socioeconômico de usuários no Arquivo Público do Estado do Rio Grande do Sul
Este trabalho tem como objetivo compreender as características de perfil socioeconômico dos usuários/pesquisadores no contexto do Arquivo Público do Estado do Rio Grande do Sul (APERS). Também busca elencar elementos que possam compor estudos de usuário para compreender os contextos socioeconômicos de desigualdade no âmbito dos usuários pesquisadores de arquivos e caracterizar do perfil dos usuários e não usuários do APERS por meio de suas características sociais e econômicas. Para isso, foram realizadas reflexões sobre a formação da sociedade e do Estado, a partir do método de análise materialista histórico e dialético, bem como utilizou-se dados sociais e econômicos que evidenciam a existência de grupos sociais específicos que sofrem mais com as desigualdades por conta da classe, cor, sexo, orientação sexual e religião. Apresentamos o desenvolvimento da Arquivologia durante a história e o surgimento de paradigmas que possuem especificidades práticas e teóricas entre sí, pavimentando o surgimento de perspectivas cada vez mais sociais dentro da área. A evolução dos Estudos de Usuários enquanto instrumento para se pensar em estratégias de acesso e difusão também foi abordada. A identificação do perfil socioeconômico dos usuários do APERS foi realizada por meio dos dados obtidos a partir da aplicação de questionário. Através dos resultados observou-se a falta de diversidade do perfil social e econômico dos usuários da instituição, evidenciando a necessidade de ações que visem compreender e alterar, estruturalmente, essa realidade, afim de democratizar o arquivo.This work aims to understand the characteristics of the socioeconomic profile of users/researchers in the context of the Public Archive of the State of Rio Grande do Sul (APERS). It also seeks to list elements that can compose user studies to understand the socioeconomic contexts of inequality within the scope of file researcher users and to characterize the profile of APERS users and non-users through their social and economic characteristics. For this, reflections were carried out on the formation of society and the State, based on the method of historical and dialectical materialistic analysis, as well as using social and economic data that demonstrate the existence of specific social groups that suffer more from inequalities due to account of class, color, gender, sexual orientation and religion. We present the development of Archivology throughout history and the emergence of paradigms that have practical and theoretical specificities among themselves, paving the way for the emergence of increasingly social perspectives within the area. The evolution of User Studies as an instrument for thinking about access and dissemination strategies was also discussed. The identification of the socioeconomic profile of the APERS users was made through the data obtained through the application of a questionnaire. Through the results, the lack of diversity in the social and economic profile of the institution's users was observed, highlighting the need for actions aimed at understanding and structurally changing this reality, in order to democratize the archive
Reconstruction of gene regulatory networks from postgenomic data
Institute for Adaptive and Neural ComputationAn important problem in systems biology is the inference of biochemical pathways
and regulatory networks from postgenomic data. The recent substantial increase
in the availability of such data has stimulated the interest in inferring the networks
and pathways from the data themselves. The main interests of this thesis
are the application, evaluation and the improvement of machine learning methods
applied to the reverse engineering of biochemical pathways and networks. The
thesis starts with the application of an established method to newly available gene
expression data related to the interferon pathway of the human immune system
in order to identify active subpathways under di erent experimental conditions.
The thesis continues with the comparative evaluation of various machine learning
methods (Relevance networks, Graphical Gaussian Models, Bayesian networks)
using observational and interventional data from cytometry experiments as well
as simulated data from a gold-standard network. The thesis also extends and improves
existing methods to include biological prior knowledge under the Bayesian
approach in order to increase the accuracy of the predicted networks and it quanti
es to what extent the reconstruction accuracy can be improved in this way
Administradores recém formados : competências esperadas por empresas do Distrito Federal
Monografia (graduação)—Universidade de Brasília, Faculdade de Economia, Administração e Contabilidade, Departamento de Administração, 2016.O objetivo deste estudo foi identificar, junto a organizações de diversos ramos de
atividade, atuantes em Brasília, quais as competências esperadas para
administradores recém formados. Baseada em uma abordagem quali-quantitativa, a
pesquisa caracterizou-se como sendo de campo e descritiva, com corte transversal.
Os respondentes do estudo foram empresas de diferentes atividades e a amostra
foram profissionais que atuam no recrutamento e seleção de seis empresas
participantes. Os dados foram coletados com o uso de roteiro de entrevista, semiestruturado,
e aplicação de questionário desenvolvido por Godoy e Forte (2007). Foi
feito o relato das questões discursivas com o uso de planilha e estatística descritiva
para os questionários. Como resultado, foi possível observar que tanto
competências técnicas quanto comportamentais são demandadas para os
administradores recém formados, todavia, as competências comportamentais são
mais valorizadas por estarem alinhadas com a realidade de mercado dessas
empresas
Avoiding spurious feedback loops in the reconstruction of gene regulatory networks with dynamic bayesian networks
Feedback loops and recurrent structures are essential to the regulation and stable control of complex biological systems. The application of dynamic as opposed to static Bayesian networks is promising in that, in principle, these feedback loops can be learned. However, we show that the widely applied BGe score is susceptible to learning spurious feedback loops, which are a consequence of non-linear regulation and autocorrelation in the data. We propose a non-linear generalisation of the BGe model, based on a mixture model, and demonstrate that this approach successfully represses spurious feedback loops
Decrypting strong and weak single-walled carbon nanotubes interactions with mitochondrial voltage-dependent anion channels using molecular docking and perturbation theory
[Abstract] The current molecular docking study provided the Free Energy of Binding (FEB) for the interaction (nanotoxicity) between VDAC mitochondrial channels of three species (VDAC1-Mus musculus, VDAC1-Homo sapiens, VDAC2-Danio rerio) with SWCNT-H, SWCNT-OH, SWCNT-COOH carbon nanotubes. The general results showed that the FEB values were statistically more negative (p (SWCNT-VDAC1-Mus musculus) > (SWCNT-VDAC1-Homo sapiens) > (ATP-VDAC). More negative FEB values for SWCNT-COOH and OH were found in VDAC2-Danio rerio when compared with VDAC1-Mus musculus and VDAC1-Homo sapiens (p r2 > 0.97) was observed between n-Hamada index and VDAC nanotoxicity (or FEB) for the zigzag topologies of SWCNT-COOH and SWCNT-OH. Predictive Nanoparticles-Quantitative-Structure Binding-Relationship models (nano-QSBR) for strong and weak SWCNT-VDAC docking interactions were performed using Perturbation Theory, regression and classification models. Thus, 405 SWCNT-VDAC interactions were predicted using a nano-PT-QSBR classifications model with high accuracy, specificity, and sensitivity (73–98%) in training and validation series, and a maximum AUROC value of 0.978. In addition, the best regression model was obtained with Random Forest (R2 of 0.833, RMSE of 0.0844), suggesting an excellent potential to predict SWCNT-VDAC channel nanotoxicity.Brasil. Conselho Nacional de Desenvolvimento Científico e Tecnológico; 552131/2011-3Brasil. Conselho Nacional de Desenvolvimento Científico e Tecnológico; 454332/2014-9Galicia. Consellería de Cultura, Educación e Ordenación Universitaria; R2014/03
- …