Spiking Neural P Systems with Structural Plasticity: Attacking the Subset Sum Problem

Spiking neural P systems with structural plasticity (in short, SNPSP systems) are models of computations inspired by the function and structure of biological neurons. In SNPSP systems, neurons can create or delete synapses using plasticity rules. We report two families of solutions: a non-uniform and a uniform one, to the NP-complete problem Subset Sum using SNPSP systems. Instead of the usual rule-level nondeterminism (choosing which rule to apply) we use synapse-level nondeterminism (choosing which synapses to create or delete). The nondeterminism due to plasticity rules have the following improvements from a previous solution: in our non-uniform solution, plasticity rules allowed for a normal form to be used (i.e. without forgetting rules or rules with delays, system is simple, only synapse-level nondeterminism); in our uniform solution the number of neurons and the computation steps are reduced.Ministerio de Economía y Competitividad TIN2012-3743

Prevalencia de factores asociados a la enfermedad cardiovascular y su relación con el ausentismo laboral de los trabajadores de una entidad oficial

Introduction: Cardiovascular disease is the first cause of death in the world. This phenomenon is attributed to life styles, such a sedentarism, ingestion of high calorie foods, and alcohol and tobacco consumption. This leads to an increase in the rates of obesity, dyslipidaemia, and hypertension. These then become risk factors that directly affect the prevalence of disease and death of cardiovascular origin, which consequently represents a significant health problem in the working population. Objective: To determine the factors associated with cardiovascular disease and their relationship with work absenteeism in a government office in the City of Bogota, Colombia. Materials and methods: A descriptive study was carried out using the work records of 214 employees. Sociodemographic, clinical-cardiovascular, and work variables were also recorded. An analysis was performed on the independent variables and the outcome, and a logistic regression model was prepared using work absenteeism as a dependent variable. Results: The prevalences of the sample were: smoking, 13.1%; alcohol consumption, 35.1%; sedentarism, 39.7%; overweight or obese workers, 54.2%; and elevated total cholesterol, 43.9%. Treatment was being received for hypertension in 29.9%, with 4.7% for diabetes, and 21.5% for lipid disorders. Conclusion: The prevalence of risk factors associated with cardiovascular disease is similar to that found in other studies on the working population. The regression model showed that the variables marital status, obesity, treatment for hypertension, diastolic blood pressure level, and length of service, behaved as predictive variables of work absenteeism. © 2019 Sociedad Colombiana de Cardiología y Cirugía Cardiovascula

“Las Yeseras”, un paisaje geográfico cultural en abandono ligado al sistema constructivo tradicional

En el NE de la Sierra del Algarrobo, en el oeste del Campo de Cartagena, se localiza una de las canteras de yeso más importantes de la comarca, en producción, para la arquitectura tradicional, hasta hace 40 años y cuyas instalaciones se encuentran en ruinas. El lugar, conocido como “Las Yeseras”, conforma un paisaje cultural, reflejo del diálogo tradicional sociedad-naturaleza. En el presente trabajo se pretende identificar este paisaje en todos sus elementos y reconstruir su histórica funcionalidad. Para ello, se recurre al testimonio in situ de antiguos trabajadores, así como a bibliografía científica, fuentes estadísticas y herramientas de los SIG. Se demuestra la ligazón de la actividad extractiva tradicional del yeso al sistema social “precapitalista”, se detallan los trabajos de extracción, cocción, molido y comercialización del yeso y se caracterizan las instalaciones de la cantera, en su estado anterior y actual; también se descubre el régimen de propiedad y su área de influencia. Se concluye con una descripción del estado actual de todo el conjunto yesero y haciendo un llamamiento a su reconocimiento como paisaje cultural y la necesidad de su conservación y difusión

Fabrication and Characterization of Multiband Solar Cells Based on Highly Mismatched Alloys

Multiband solar cells are one type of third generation photovoltaic devices in which an increase of the power conversion efficiency is achieved through the absorption of low energy photons while preserving a large band gap that determines the open circuit voltage. The ability to absorb photons from different parts of the solar spectrum originates from the presence of an intermediate energy band located within the band gap of the material. This intermediate band, acting as a stepping stone allows the absorption of low energy photons to transfer electrons from the valence band to the conduction band by a sequential two photons absorption process. It has been demonstrated that highly mismatched alloys offer a potential to be used as a model material system for practical realization of multiband solar cells. Dilute nitride GaAs1-xNx highly mismatched alloy with low mole fraction of N is a prototypical multiband semiconductor with a well-defined intermediate band. Currently, we are using chemical beam epitaxy to synthesize dilute nitride highly mismatched alloys. The materials are characterized by a variety of structural and optical methods to optimize their properties for multiband photovoltaic devices

Residual Forage and Animal Performance from a Kikuyo Pasture under Mixed Grazing and Supplementation

Five grazing strategies were compared: grazing by ewes only and mixed grazing (ewes + heifers), in mixed grazing heifers received no supplement or one of three supplements. Ruminal undegradable protein (RUP) varied among supplement: 4.25, 9.11 and 9.13%, the supplement with the highest RUP included protected methionine. All supplements were 21% crude protein and 3.0 Mcal/kg of metabolizable energy. Grazing was on kikuyu, ratio was 30 kg of ewe per 100 kg of heifer in the mixed grazing treatments. Experimental grazing lasted 84 days. Variables measured were residual forage, proline content in residual forage and liveweight gains per animal and per hectare. Experimental design was a completely random with two replicates. Residual forage was the highest (P\u3c 0.05) in mixed grazing and RUP in supplement was above 4.25%. The highest (P\u3c 0.05) proline content was found in grazing by ewes only, 52% above the proline content found in mixed grazing without supplement, when heifers received supplement proline content decreased (P\u3c 0.05) further. Grazing by ewes only and mixed grazing with heifersreceiving the highest RUP in supplement showed the highest (P\u3c 0.05) daily liveweight gain per ewe of 134 g. Mixed grazing in which heifers received no supplement gave a 100% increase (P\u3c 0.05) in liveweight gain per hectare compared to grazing by ewes only. In mixed grazing offering a supplement with 9.13% RUP and protected methionine gave both the highest liveweight gains per animal and per hectare. It was concluded that mixed grazing allowed a lower stress level on kikuyu due to defoliation and a higher liveweight gain per hectare than grazing by ewes only

Creencias adultas sobre la memoria infantil

Setenes Jornades de Foment de la Investigació de la FCHS (Any 2001-2002)El objetivo de este trabajo es identificar las ideas previas que una muestra de estudiantes universitarios tienen sobre diferentes aspectos del funcionamiento de la memoria infantil. Para ello, hemos elaborado un cuestionario que aborda distintos aspectos relacionados con el desarrollo de la memoria en los niños. Dicho cuestionario ha sido pasado a 70 estudiantes de la Universitat Jaume I. En general, los resultados indican un acierto cercano al 30% del conjunto de los ítems presentados, realizando predicciones particularmente correctas sobre el funcionamiento de la metamemoria y el fenómeno de la amnesia infantil. Sin embargo, no sucede lo mismo con el desarrollo estratégico y con el funcionamiento temprano de la memoria

Concepciones implícitas sobre el desarrollo infantil

Setenes Jornades de Foment de la Investigació de la FCHS (Any 2001-2002)Partiendo del trabajo de Martí, E. et al. (1994) “ Ideas previas de una población universitaria sobre el desarrollo infantil” hemos realizado un estudio descriptivo para identificar las concepciones implícitas del conocimiento que tienen estudiantes universitarios sobre el desarrollo infantil. La muestra estaba constituida por 111 estudiantes de la Universitat Jaume I, con una media de edad de 19 años. Mediante un cuestionario hemos analizado el nivel de conocimientos sobre las edades en las que se adquieren distintos logros del calendario evolutivo. En el cuestionario se consideraban tres áreas del desarrollo: El desarrollo motor y perceptivo, el desarrollo cognitivo y lingüístico, y el desarrollo social y de la personalidad. En general, los resultados indican la existencia de un desajuste entre sus creencias y el desarrollo real de los niños, mostrando un conocimiento más ajustado en el área cognitivo-lingüística que en el resto de las áreas analizadas