Effect of DNA repair deficiencies on the cytotoxicity of resveratrol

Numerous preclinical studies have shown that the naturally-occurring polyphenol resveratrol may produce health-beneficial effects in a variety of disorders, including cancer, diabetes, Alzheimer, and cardiovascular diseases. Resveratrol has entered clinical trials for the prevention and treatment of several of these disorders. This polyphenol is also available in the market as a dietary supplement. Experimental data have shown, however, that resveratrol induces DNA damage in a variety of cells. Here we review such evidence and evaluate the cytotoxicity of resveratrol (MTT assay) in cells deficient in several major DNA repair pathways (i.e., homologous recombination, non-homologous end joining, base excision repair, nucleotide excision repair, mismatch repair, and Fanconi anemia repair). Cells deficient in base excision repair (EM9), nucleotide excision repair (UV4 and UV5) and Fanconi Anemia (KO40) were slightly hypersensitive to resveratrol-induced cytotoxicity with respect to their parental cells (AA8). Our results suggest that these pathways may participate in the repair of the DNA damage induced by resveratrol and that deficiencies in these pathways may confer hypersensitivity to the genotoxic activity of this dietary constituen

Curvature effects on a simplified reaction-diffusion model of biodegradation

The biodegradation process of some types of polymers occurs due to many different factors including their morphology, structure and chemical composition. Although this is a complicated process, most of its important stages like the diffusion of monomers and the hydrolysis reactions have been modeled phenomenologically through reaction-diffusion equations, where the properties of the polymers were encompassed. Using a simplified reaction-diffusion model for the biodegradation of polymers, in this contribution we study the possible effects of the curvature of the system’s geometry in the degradation process, which is characterized by the interaction of the corresponding reaction rate and the diffusion coefficient. To illustrate the problem of diffusion on a curved surface we consider the surface of a cylinder and of the so-called Gaussian bump. We show how the degradation process is affected by the curvature of the system for the simplified model

Dalla fotografia digitale alla fotogrammetria per i Beni Culturali Documentazione e Divulgazione

Licencia Creative Commons: Reconocimiento – NoComercial (by-nc)[EN] Digital photography is considered a valuable tool for cultural heritage documentation. Surveying and photogrammetry are required to achieve metric and accurate results in drawings, 2D/3D modelling and texturing. This paper presents the photogrammetric workflow from data acquisition to photorealistic 3D modelling and four heritage documentation case studies in different sites. High resolution and high accuracy photorealistic 3D models allow experts to recreate and interact virtually with cultural heritage either before, during of after intervention. Managers and information experts of cultural heritage monuments and sites should consider photogrammetric by-products not only to enrich knowledge, improve understanding and provide scientific records but to ease dissemination of heritage resources.[IT] La fotografia digitale è considerata un valido strumento per la documentazione del patrimonio culturale. Topografia e fotogrammetria sono necessari per ottenere risultati metrici precisi nei disegni, modellazione 2D/3D e texturing. Questo articolo descrive il processo di lavoro adottato dall'acquisizione dati alla modellazione 3D fotorealistica. Inoltre, sono documentati alcuni casi studio relativi a diversi siti. I Manager e gli esperti di comunicazione sul patrimonio culturale, dovrebbero considerare la fotogrammetria uno strumento non solo per arricchire la conoscenza, per migliorare la comprensione e fornire registrazioni scientifiche, ma anche per facilitare la diffusione delle risorse del patrimonio.The authors woild lide to thank the support provided by the Spanish Ministry of Science and Innovation to the project HAR2010-18620Lerma García, JL.; Cabrelles López, M.; Navarro Tarin, S.; Fabado Salvador, S. (2013). From Digital Photography to Photogrammetry for Cultural Heritage Documentation and Dissemination. DisegnareCon. 6(12):1-8. https://doi.org/10.6092/issn.1828-5961/3850S1861

Maximum likelihood inference for a class of discrete-time Markov-switching time series models with multiple delays

Autoregressive Markov switching (ARMS) time series models are used to represent real-world signals whose dynamics may change over time. They have found application in many areas of the natural and social sciences, as well as in engineering. In general, inference in this kind of systems involves two problems: (a) detecting the number of distinct dynamical models that the signal may adopt and (b) estimating any unknown parameters in these models. In this paper, we introduce a class of ARMS time series models that includes many systems resulting from the discretisation of stochastic delay differential equations (DDEs). Remarkably, this class includes cases in which the discretisation time grid is not necessarily aligned with the delays of the DDE, resulting in discrete-time ARMS models with real (non-integer) delays. We describe methods for the maximum likelihood detection of the number of dynamical modes and the estimation of unknown parameters (including the possibly non-integer delays) and illustrate their application with an ARMS model of El Ni\~no--southern oscillation (ENSO) phenomenon

Una aproximación integradora al estudio del burnout en los profesores de Universidad

The aim of this paper is to use an integrative approach to identify the main correlates and/or predictors at different levels (personal, psychosocial, occupational and outside the workplace) of the burnout dimensions. The sample consists of 813 university professors. Results from statistical analyses show that there are, indeed, both common and specific predictors for the different facets of the syndrome. Specifically, while social support and optimism are selected to confirm all manifestations of burnout, other factors (work hours per week, time in the profession, hardiness, Type A behavioural pattern, life events, daily hassles) do increase the emergence of differential profiles. Lastly, findings are discussed and the main conclusions are presentedEl objetivo del presente trabajo es identificar, desde un acercamiento integrador, cuáles son los principales correlatos y/o predictores de distintos ámbitos (personal, psicosocial, ocupacional y extralaboral) de las dimensiones del burnout. La muestra está formada por 813 profesores de Universidad. Los resultados de los análisis estadísticos realizados permiten constatar la existencia de predictores comunes y específicos para las facetas del síndrome. Concretamente, mientras se confirma que el apoyo social y el optimismo son seleccionados para explicar todas las manifestaciones del burnout, otros factores (horas de trabajo a la semana, tiempo en la profesión, personalidad resistente, patrón de conducta Tipo A, acontecimientos vitales, contrariedades cotidianas) acentúan la existencia de perfiles diferenciales. Finalmente, se discuten los hallazgos y se presentan las principales conclusionesThis study was possible thanks to a grant given to the project «Análisis de los determinantes psicosociales y biológicos en el estrés laboral de los docentes universitarios» (reference PGIDT99PXI21103A; BSO2000-0475) financed by the Consellería de Educación y Ordenación Universitaria of the Xunta de Galicia and by the Ministerio de Educación y CienciaS

Big Five Personality Traits, Coping Strategies and Compulsive Buying in Spanish University Students

Personality traits and coping strategies have historically been two key elements in the field of health psychology. It is, therefore, striking that there is no study in the field of compulsive buying that integrates the most generic, decontextualized and stable aspects (traits) with those having a more marked processual and dynamic nature, which are closer to goal-based views of human nature (coping strategies). Another weakness of the compulsive buying field is that, despite the confirmed growing increase in compulsive buying in the younger age groups, most studies have been conducted with adult samples. Hence, this study seeks to clarify the role of the Big Five domains and different coping strategies in university students’ compulsive buying. The sample consisted of 1093 participants who were classified as either compulsive buyers or non-compulsive buyers. Both groups were compared regarding sociodemographic variables (gender, age), the Big Five personality traits, and coping strategies through chi-square tests or Student’s t-tests. Besides, a multivariate logistic regression analysis was conducted to determine which of these determinants might play a part in the construction of a risk profile for compulsive buying. The results showed that other than gender (specifically being female), Neuroticism and the use of such coping strategies as problem avoidance and wishful thinking are risk factors that increase the propensity for compulsive buying. The use of active coping strategies such as problem solving, cognitive restructuring and social support, as well as the Conscientiousness dimension are protection factors that decrease the likelihood of becoming a compulsive buyer. Finally, and on the basis of the findings obtained, possible guidelines are given, which, hopefully, may effectively contribute to the prevention of and/or intervention in compulsive buying among young adultsS

Value, quality, purchasing habits and repurchase intention in B2C: differences between frequent and occasional purchasers

Este estudio propone un modelo integrador de la recompra en comercio electrónico (B2C), basado en la teoría de la confirmación de expectativas, tomando como partida el modelo de Bhattacherjee extendido con el modelo de satisfacción Cronin. El modelo de investigación se ha probado con 536 compradores españoles, usando análisis multigrupo. El modelo fue capaz de explicar más del setenta por ciento de la varianza de la intención de recompra. Como resultados, la relación entre la calidad y la satisfacción es no significativa para todos los tipos de consumidores y la relación entre la utilidad y la recompra es no significativa sólo para los compradores más frecuentes. Algunas ideas para llevar a la práctica son presentadas a modo de discusión

Conocimiento, Actitudes y Practicas sobre Anticoncepción de emergencia en estudiantes de IV y V año de la carrera de medicina UNAN-Managua; ENERO 2014

La fecundidad juega un papel fundamental para la transición demográfica de un país subdesarrollado a un país moderno, un aumento de esta conlleva al aumento de la mortalidad materno-infantil, obligando a los gobiernos a destinar recursos económicos con el propósito de disminuir la mortalidad los cuales podrían ser utilizados para educación, trabajo, financiamiento a productores, proyectos sociales, entre otros. La familia nicaragüense es numerosa, fecunda. Nicaragua es un país de jóvenes y de niños: el 40% de su población es menor de 15 años. La tasa de fecundidad varía ligeramente en las distintas zonas del país. En el departamento de Managua, el promedio es de 5 hijos por mujer al concluir su período fértil. En otras ciudades del Pacífico, el promedio es de 5 y 6 hijos. En las ciudades del Atlántico es de 6 y 7 hijos por mujer. Generalmente la mujer comienza su vida sexual muy joven. Según datos del Informe "Familia y Fecundidad", el 38.28% de las mujeres han comenzado a vivir acompañadas entre los 14 y 16 años y el 72.72% entre los 14 y los 19 años. Nicaragua había experimentado el mayor incremento relativo de nacimientos en mujeres entre 15 y 19 años (1993), lo que supone aumento de riesgo materno infantil. Estudios recientes muestran que los adolescentes entre 13 y 18 años de edad ya iniciaron su vida sexual aumentando la incidencia de enfermedades de transmisión sexual y embarazos precoces. Los métodos de planificación familiar ayudan a reducir altas tasas de fecundidad, pero los adolescentes en un 78% no utilizan ningún método; un adolescente de 14 años que tiene una relación sexual sin protección, se traduce a “un fracaso en el desarrollo personal” porque no está listo física, psicológica, ni emocionalmente. Además, que trae al mundo a un hijo que no se desea, con todas las consecuencias que esto pueda acarrear. Así mismo, las PPMS (que no es un método de planificación familiar, tan solo un método de emergencia), es muy utilizada de manera irresponsable. Alrededor del mundo existen publicaciones para colocar la anticoncepción en los países en desarrollo para mujeres y jóvenes, en el que describen el enfoque único para este producto esencial, pero poco utilizado y que sea más accesible a las mujeres y adolescentes. En Nicaragua, en las actividades de capacitación se han incluido al personal de farmacia y esta incluido en las normas de salud. Estos esfuerzos realizados para que la Anticoncepción de Emergencia sea aceptada han dado frutos ya que es conocido por los proveedores de servicios y por la población, esta disponible en las farmacias y se ha registrado como un producto que se vende en las farmacias privadas y es distribuido por ONG ́

Functional EF-hands in neuronal calcium sensor GCAP2 determine its phosphorylation state and subcellular distribution in vivo, and are essential for photoreceptor cell integrity

The neuronal calcium sensor proteins GCAPs (guanylate cyclase activating proteins) switch between Ca2+-free and Ca2+-bound conformational states and confer calcium sensitivity to guanylate cyclase at retinal photoreceptor cells. They play a fundamental role in light adaptation by coupling the rate of cGMP synthesis to the intracellular concentration of calcium. Mutations in GCAPs lead to blindness. The importance of functional EF-hands in GCAP1 for photoreceptor cell integrity has been well established. Mutations in GCAP1 that diminish its Ca2+ binding affinity lead to cell damage by causing unabated cGMP synthesis and accumulation of toxic levels of free cGMP and Ca2+. We here investigate the relevance of GCAP2 functional EF-hands for photoreceptor cell integrity. By characterizing transgenic mice expressing a mutant form of GCAP2 with all EF-hands inactivated (EF(-)GCAP2), we show that GCAP2 locked in its Ca2+-free conformation leads to a rapid retinal degeneration that is not due to unabated cGMP synthesis. We unveil that when locked in its Ca2+-free conformation in vivo, GCAP2 is phosphorylated at Ser201 and results in phospho-dependent binding to the chaperone 14-3-3 and retention at the inner segment and proximal cell compartments. Accumulation of phosphorylated EF(-)GCAP2 at the inner segment results in severe toxicity. We show that in wildtype mice under physiological conditions, 50% of GCAP2 is phosphorylated correlating with the 50% of the protein being retained at the inner segment. Raising mice under constant light exposure, however, drastically increases the retention of GCAP2 in its Ca2+-free form at the inner segment. This study identifies a new mechanism governing GCAP2 subcellular distribution in vivo, closely related to disease. It also identifies a pathway by which a sustained reduction in intracellular free Ca2+ could result in photoreceptor damage, relevant for light damage and for those genetic disorders resulting in 'equivalent-light'' scenarios