Recursion relations for multi-gluon off-shell amplitudes on the light-front and Wilson lines

We analyze the off-shell scattering amplitudes in the framework of the light-front perturbation theory. It is shown that the previously derived recursion relation between tree level off-shell amplitudes in this formalism actually resums whole classes of graphs into a Wilson line. More precisely, we establish a correspondence between the light-front methods for the computation of the off-shell amplitudes and the approach which makes use of the matrix elements of straight infinite Wilson lines, which are manifestly gauge invariant objects. Furthermore, since it is needed to explicitly verify the gauge invariance of light-front amplitudes, it is demonstrated that the Ward identities in this framework need additional instantaneous terms in the light-front graphs.Comment: 26 pages, a few figure

Position dependent mass Scarf Hamiltonians generated via the Riccati equation

Producción CientíficaThe construction of position dependent mass Scarf Hamiltonians of the trigonometric as well as the hyperbolic types is addressed by means of the factorization method and the Riccati equation. These Hamiltonians are shown to be independent of the ordering parameter of the kinetic term. Additionally, new families of Hamiltonians with the Scarf spectrum are also determined by supersymmetry. Some examples for masses with and without singularities are considered to illustrate our results

Evaluación de las condiciones de mezcla y su influencia sobre el cloro residual entanques de compensación de un sistema de distribución de agua potable

We performed a real scale evaluation of mixing conditions and its influence on water quality in a compensation tank of drinking-water distribution system located in the city of Cali, Colombia. The hydrodynamic study with continuous injection of tracer, and temperature and free chlorine measurements for identifying the mixing regime in the tank’s interior, residence time, thermal stratification, and chlorine variations in the stored water showed the typical characteristics of a compensation tank. We concluded that water recirculation, inadequate water exchange, low moment fluxes associated with low velocity flows, and punctual thermal stratification could lead to high water age, high residence times in the tank, inadequate mixing, and important loss of free residual chlorine. The methodology developed is suitable for evaluation and optimization of compensation tanks of drinking water distribution systems.Realizamos una evaluación a escala real de las condiciones de mezcla y su influencia en la calidad del agua en un tanque de compensación del sistema de distribución de agua potable ubicado en la ciudad de Cali, Colombia. El estudio hidrodinámico con inyección continua de marcador y mediciones de temperatura y cloro libre para identificar el régimen de mezcla en el interior del tanque, el tiempo de residencia, la estratificación térmica y las variaciones de cloro en el agua almacenada mostraron las características típicas de un tanque de compensación. Llegamos a la conclusión de que la recirculación de agua, el intercambio de agua inadecuado, los flujos de momento bajos asociados con los flujos de baja velocidad y la estratificación térmica puntual podrían conducir a una alta edad del agua, tiempos de residencia elevados en el tanque, mezcla inadecuada y pérdida importante de cloro residual libre. La metodología desarrollada es adecuada para la evaluación y optimización de tanques de compensación de sistemas de distribución de agua potable

Microscale generation of entangled photons without momentum conservation

We report, for the first time, the generation of entangled photon pairs via type-0 spontaneous parametric down conversion in an ultra-thin wafer of lithium niobate in which momentum between the pump photon and daughter photons is not conserved. The characteristics of the emission are investigated using several techniques. We find that non-phase matched SPDC is a promising source of ultra-broadband two photon radiation that exhibits remarkably tight correlation widths in both the spatial and temporal domains.Comment: 9 pages, 8 figure

Los estilos educativos de los padres y la competencia psicosocial de los adolescentes

This study examined the relationship between parenting styles and adolescents' psychosocial competence. Parents of 372 students between 11 and 15 years old were classified according to the student perception in four groups: pemissive, authoritative, authoritarian and neglectful. Several aspects related to the students' psychosocial competence were assessed through self-report measures. Results showed that both adolescents perceiving their parents as permissive and adolescents perceiving their parents as authoritative obtained the highest scores in perceived social competence and self-esteem. Moreover, their behavior in the classroom was more positive, and they were less rejected by their  classmates. These jindings are discussed in tems of the dimensions of acceptance and control underlying rhe various parenting styles.Este estudio analiza las relaciones entre los estilos educativos de los padres y algunas variables relacionadas con la competencia psicosocial de los adolescentes. Para ello se clasificó a los padres de 372 estudiantes de 11 a 15 años en cuatro grupos: permisivos, democráticos, autoritariose indiferentes. Los estudiantes cumplimentaron autoinformespara evaluar distintos aspectos relacionados con su competencia psicosocial. Los resultados indican que los adolescentes que consideran a sus padres como permisivos o democráticos obtienen puntuaciones más altas en sus percepciones de competencia social y en autoestima. Sus profesores consideran que su conducta en clase es más positiva, y reciben menos rechazo de sus cornpañeros. Estos resultados se discuten considerando las dimensiones de afecto y control que subyacen a los distintos estilos educativosde los padres

EQ-5D-5L Health-State Values for the Mexican Population.

OBJECTIVE: To generate a value set for the Mexican adult general population to support and facilitate the inclusion of quality-adjusted life years (QALYs) into the health technology assessment process of the Mexican healthcare authorities. METHODS: A representative sample of the Mexican adult population stratified by age, sex and socio-economic status was used. Following version 2.0 of the EuroQol EQ-5D-5L valuation protocol, trained interviewers guided participants in completing composite time trade-off (cTTO) and discrete-choice experiment (DCE) tasks included in the EQ-VT software. Generalized least squares, Tobit and Bayesian models were used for cTTO data. The choice of value set model was based on criteria that included: theoretical considerations, parsimony, logical ordering of coefficients, and statistical significance. RESULTS: Based on quality control criteria and interviewer judgment, 1000 out of 1032 participants provided useable responses. Participants' demographic characteristics were similar to the 2010 Mexican Population Census and followed the socioeconomic structure defined by the Mexican Association of Marketing Research and Public Opinion Agencies (AMAI). The predicted index values in the final cTTO model (a heteroscedastic censored model with Bayesian estimation) ranged from - 0.5960 to 1, with 19.7% of all predicted health state scores less than 0 (i.e., worse than dead). CONCLUSION: This study has generated the first value set representing the stated preferences of the Mexican adult population for use in estimating QALYs. The resulting EQ-5D-5L value set is technically robust and will facilitate health economic analyses as well as quality-of-life studies

Towards Automated Semantic Segmentation in Mammography Images

Mammography images are widely used to detect non-palpable breast lesions or nodules, preventing cancer and providing the opportunity to plan interventions when necessary. The identification of some structures of interest is essential to make a diagnosis and evaluate image adequacy. Thus, computer-aided detection systems can be helpful in assisting medical interpretation by automatically segmenting these landmark structures. In this paper, we propose a deep learning-based framework for the segmentation of the nipple, the pectoral muscle, the fibroglandular tissue, and the fatty tissue on standard-view mammography images. We introduce a large private segmentation dataset and extensive experiments considering different deep-learning model architectures. Our experiments demonstrate accurate segmentation performance on variate and challenging cases, showing that this framework can be integrated into clinical practice.Comment: 6 page

Los estilos educativos de los padres y la competencia psicosocial de los adolescentes

This study examined the relationship between parenting styles and adolescents' psychosocial competence. Parents of 372 students between 11 and 15 years old were classified according to the student perception in four groups: pemissive, authoritative, authoritarian and neglectful. Several aspects related to the students' psychosocial competence were assessed through self-report measures. Results showed that both adolescents perceiving their parents as permissive and adolescents perceiving their parents as authoritative obtained the highest scores in perceived social competence and self-esteem. Moreover, their behavior in the classroom was more positive, and they were less rejected by their  classmates. These jindings are discussed in tems of the dimensions of acceptance and control underlying rhe various parenting styles.Este estudio analiza las relaciones entre los estilos educativos de los padres y algunas variables relacionadas con la competencia psicosocial de los adolescentes. Para ello se clasificó a los padres de 372 estudiantes de 11 a 15 años en cuatro grupos: permisivos, democráticos, autoritariose indiferentes. Los estudiantes cumplimentaron autoinformespara evaluar distintos aspectos relacionados con su competencia psicosocial. Los resultados indican que los adolescentes que consideran a sus padres como permisivos o democráticos obtienen puntuaciones más altas en sus percepciones de competencia social y en autoestima. Sus profesores consideran que su conducta en clase es más positiva, y reciben menos rechazo de sus cornpañeros. Estos resultados se discuten considerando las dimensiones de afecto y control que subyacen a los distintos estilos educativosde los padres

Frequency of Mutations in Brca1 and Brca2 Genes in Women with Breast Cancer in Córdoba, Argentina

The discovery of BRCA1 and BRCA2 genes has led to the introduction of increasingly sophisticated genetic tests to measure the risk of hereditary breast cancer, among other things. The aim of this study was to determine the prevalence of the mutation in 24 women from Córdoba with breast / ovarian cancer (BC / OC) and with at least two relatives with breast cancer. Although there are recurrent mutations, which appear repeatedly in unrelated families, with highest prevalence as in the Jewish ethnicity, this is the first study on the population of the province of Córdoba, Argentina.Fil: Lerda, Daniel Enrique. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; ArgentinaFil: Bella, Santiago Rafael. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; ArgentinaFil: Biagi Bistoni, Marta Inés. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; Argentin