Proposition of a method for stochastic analysis of value streams

This article aims at proposing a method to stochastically analyze values streams taking into consideration the effect of critical uncertainty sources on lead time. The proposed method combines value stream mapping (VSM) and Monte Carlo simulation to identify improvement opportunities. To illustrate this approach, we carried out a case study in the special nutrition value stream of a Brazilian public hospital. Results show that the proposed method allows the identification of improvement opportunities that would not be considered in the classical deterministic VSM approach. Further, the integration of the stochastic analysis enables the determination of a more realistic lead time, which supports a more assertive planning and scheduling of the value stream. The proposed method addresses a fundamental gap in traditional VSM without adding much complexity to the analysis procedure, which is a common practical issue in previous works that integrated other stochastic methods into VSM

Relationship Characteristics Associated with Teen Dating Violence Perpetration

Teen dating violence (TDV) is unstable across dating relationships, suggesting that characteristics of the relationship could be related to TDV. Few empirical studies have examined these links. This study examined associations between relationship characteristics and TDV perpetration among teens and sex differences in those associations. Relationship characteristics examined include tactics used to manipulate partners; ways of responding to relationship problems; relationship duration; exclusivity of the relationship; age difference between partners; and history of sexual intercourse with partner. Data were drawn from 667 teens in a current relationship (62.5% female and 81.4% white) enrolled in the 11th or 12th grade in 14 public schools in a rural US state. Bivariate and multivariable regression analyses examined proposed associations. 30.1% and 8.2% of teens reported controlling and physical TDV perpetration, respectively. In multivariable models, frequent use manipulation tactics increased risk for controlling or physical TDV perpetration. Teens dating a partner two or more years younger were at significantly increased risk for both controlling and physical perpetration. A significant interaction emerged between sex and exit/neglect accommodation for physical TDV. Characteristics of a current dating relationship play an important role in determining risk for controlling and physical TDV perpetration

Gravitational waves during inflation from a 5D large-scale repulsive gravity model

We investigate, in the transverse traceless (TT) gauge, the generation of the relic background of gravitational waves, generated during an early inflationary stage, on the framework of a large-scale repulsive gravity model. We calculate the spectrum of the tensor metric fluctuations of an effective 4D Schwarzschild-de-Sitter metric, which is obtained after implementing a planar coordinate transformation on a 5D Ricci-flat metric solution, in the context of a non-compact Kaluza-Klein theory of gravity. We found that the spectrum is nearly scale invariant under certain conditions. One interesting aspect of this model is that is possible to derive dynamical field equations for the tensor metric fluctuations, valid not just at cosmological scales, but also at astrophysical scales, from the same theoretical model. The astrophysical and cosmological scales are determined by the gravity- antigravity radius, which is a natural length scale of the model, that indicates when gravity becomes repulsive in nature.Comment: Improved version, accepted in Physics Letters

Modelo de un sistema multiagente para proveer ayudas adaptativas en ambientes virtuales de aprendizaje

Este artículo presenta la descripción de un modelo multiagente para ofrecer ayudas adaptativas en ambientes virtuales de aprendizaje. Las ayudas para este tipo de ambientes, en su mayoría, están pensadas de modo general, es decir, son iguales para todos los usuarios y no se consideran sus particularidades. Por tal razón, ofrecer ayudas personalizadas puede ser una estrategia para mejorar la flexibilidad de las aplicaciones de estas plataformas, donde se tenga en cuenta los tipos usuarios y sus modelos mentales individuales. El modelo propuesto está basado en la metodología Ingenias y permite la asignación de ayudas y monitoreo de los usuarios a partir de su perfil y su interacción con el aplicación.Palabras clave: agentes software, ayudas adaptativas, ambientes virtuales de aprendizaje, metodología ingenias, modelo multiagente

Genetic diversity detection of the domestic horse (Equus caballus) by genes associated with coat color

ABSTRACT Objective. To assess the population structure and genetic diversity in populations of domestic horse (Equus caballus) in the municipality Cienaga de Oro-Córdoba (Colombia). Materials and methods. Random sampling were conducted between August and October 2013, in adult animals on farms seven districts, which was carried out phenotypic characterization of each animal, based on autosomal markers encoding morphological Extension (E) , Agouti (A), Cream (C), White (W), Gray (G), Tobiano (TO), Overo (O) and Roan (RN). Population genetic parameters: allele frequency, genetic diversity, gene flow, Hardy-Weinberg equilibrium and genetic distance were calculated through the program POPGENE 1.31; the genetic structure was assessed using the program FSTAT v. 2.9.3.2. Results. 341 individuals were analyzed in the seven populations studied, where the Extension gene Was the MOST faq frequently as the Overo and Tobiano genes showed the lowest values. Insignificant values of genetic variability and population recorded a global level, likewise, low genetic differentiation among populations, accompanied by a high gene flow was obtained; an excess of heterozygotes at population and global level was observed; to this is added the presence of Hardy-Weinberg equilibrium in all populations relative to the markers studied and low genetic distance values were reported. Conclusions. The populations are highly genetically related, a situation that may result from the existing geographical proximity between them, favoring genetic exchange and the establishment of a metapopulation

HIV status and postpartum contraceptive use in an antenatal population in Durban, South Africa

We examined contraceptive use and dual protection in the post-partum period in a Prevention of Mother to Child Transmission (PMTCT) population and whether it varied by HIV status

Caracterización morfo agronómica de diecinueve cultivares de quinua (chenopodium quinoa willd.) en la sabana de bogotá

Con el propósito de proveer información acerca de la variabilidad genética y la adaptación en la Sabana de Bogotá de la colección de quinua correspondiente a la Prueba Americana y Europea de Quinua, se estudiaron 19 cultivares mediante la evaluación 49 características morfológicas y agronómicas. El ensayo se realizó en el Centro Agropecuario «Marengo» de la Universidad Nacional de Colombia, ubicado en Mosquera (Cundinamarca). El análisis estadístico, mediante componentes principales para 35 de las variables evaluadas mostró que los ocho primeros componentesexplican el 88.12% de la variación total. Estos componentesestuvieron asociados a 18 variables manifestando la diversidad entre los genotipos. Además, éstos se usaron para construir un dendograma que, calculado a partir de la distancia euclidiana, mostró la existencia de nueve grupos en los cuales se distinguieron claramente los materiales americanos de los europeos. Agronómicamente se destacaron los cultivares E-DK-4 y G-205- 95, procedentes de Dinamarca, principalmente por su precocidad, alto rendimiento en grano, alto rendimiento en biomasa ypor su porte bajo.Nineteen cultivars of «American and European Quinoa Test» were used in this assay. Forty-nine morphological and agronomic characteristics were evaluated at Research Center «Marengo» of National University of Colombia, located at Mosquera (Cundinamarca). The main objective ofthis experiment was to study the genetic variability of quinoa cultivars from American and European countries. The statistical analysis was carried out with 35 out of 49 variables. The first eight components explained the 88,12% of total variation and were constituted by 18 variables. Using this information a dendogram was constructed. Nine groupswere identified. Cultivars from American countries were separated from European's ones. The bcst cultivars were E-DK-4 and G-205-95 from Denmark. These presented high grain yield, high level of biomass, precocity and low height plant

Determinación de las relaciones genéticas en 24 accesiones de frijol común (phaseolus vulgaris)

Se caracterizaron 24 accesiones de Phaseolus vulgaris L., de las cuales 21 son de origen andino y tres mesoamericanas. Dentro de los materiales andinos, se incluyeron variedades mejoradas y cultivariedades regionales, procedentes de diversas zonas agroecológicas de Colombia. Para la  caracterización, se utilizaron 22 sistemas isoenzimáticos, ocho de los cuales mostraron buena resolución y fueron seleccionados como marcadores bioquímicos del estudio. Seis enzimas revelaron polimorfismos: Esterasa (EST), Malato deshidrogenasa (MOH), Oeshidrogenasa Shikimica (SKOH),Rubisco (RBCS), Isocitrato deshidrogenasa (IOH), y Glutamato deshidrogenasa (GOH). Las enzimas: Transaminasa glutámica oxalacética (GOT) y Endopeptidasa (EP) fueron monomórficas para todas las accesiones estudiadas. El polimorfismo se evidenció a través de 17 loci que codificaron para un mínimo de 34 alelos diferentes. Las enzimas IOH y GOHse reportan por primera vez en el fríjol común. Para establecer las relaciones entre los grupos, se usó la distancia de Jaccard y el algoritmo de agrupación UPGMA. El dendrograma obtenido conjugó dos grupos divididos en cinco subgrupos. Los grupos principales se separaron en primera instancia por el centro de domesticación: el mesoamericano y el andino, como era de esperarse. Los tres testigos mesoamericanos fueron separados del resto en un subgrupo. Las poblaciones andinas colombianas, en las cuales se centró la importancia de este estudio, fueron divididas en cuatro subgrupos que no discriminaron, en forma marcada las variedades mejoradas de las cultivariedades regionales. Los subgrupos se analizaron y discutieron de acuerdo con sus genealogías, orígenes geográficos y lugares de adaptación, más que por sus características morfológicas.Twenty four collections of common bean, 21 from Andean origin and three from Central America were characterized, using biochemical markers. Eight out of 22 isozyme systems showed good resolution. Six enzymes were polymorphic: Esterase (EST), Malate dehydrogenase (MOH), Shikimatedehydrogenase (SKOH), Rubisco (RBCS), Isocitrate dehydrogenase (IOH), and Glutamate dehydrogenase (GOH). Two other two enzymes, Glutamate oxalacetate transminase (GOT) for all accessions and Endopeptidase (EP), were monomorphic. A total of 17 loci were detected with at least 34alleles. The enzymes IOH and GOH are reported the first time for the species. To define the relationships among the accessions, the Jaccard distance and the UPGMA procedures were used. The dendogram displayed two maingroups andfive subgroups. The clusters were associated with the centers of speciess domestication : Mesoamerica and the Andes,as itwasexpected.The relationships among the subgroups were analyzed and discussed accordingto the geographical origin, sites of adaptation and lineage, rather than to their morphological similarities