Biomechanical analysis of a cranial Patient Specific Implant on the interface with the bone using the Finite Element Method

- New advance technologies based on reverse engineering , design and additive manufacturing, have expanded design capabilities for biomedical applications to include Patient Specific Implants (PSI). This change in design paradigms needs advanced tools to assess the mechanical performance of the product, and simulate the impact on the patient. In this work, we perform a structural analysis on the interface of a cranial PSI under static loading conditions. Based on those simulations, we have identified the regions with high stress and strain and checked the failure criteria both in the implant and the skull. We evaluate the quality of the design of the implant and determine their response given different materials, in order to ensure optimality of the final product to be manufactured

Mechanisms of Action and Targets of Nitric Oxide in the Oculomotor System

Nitric oxide (NO) production by neurons in the prepositus hypoglossi (PH) nucleus is necessary for the normal performance of eye movements in alert animals. In this study, the mechanism(s) of action of NO in the oculomotor system has been investigated. Spontaneous and vestibularly induced eye movements were recorded in alert cats before and after microinjections in the PH nucleus of drugs affecting the NO–cGMP pathway. The cellular sources and targets of NO were also studied by immunohistochemical detection of neuronal NO synthase (NOS) and NO-sensitive guanylyl cyclase, respectively. Injections of NOS inhibitors produced alterations of eye velocity, but not of eye position, for both spontaneous and vestibularly induced eye movements, suggesting that NO produced by PH neurons is involved in the processing of velocity signals but not in the eye position generation. The effect of neuronal NO is probably exerted on a rich cGMP-producing neuropil dorsal to the nitrergic somas in the PH nucleus. On the other hand, local injections of NO donors or 8-Br-cGMP produced alterations of eye velocity during both spontaneous eye movements and vestibulo-ocular reflex (VOR), as well as changes in eye position generation exclusively during spontaneous eye movements. The target of this additional effect of exogenous NO is probably a well defined group of NO-sensitive cGMP-producing neurons located between the PH and the medial vestibular nuclei. These cells could be involved in the generation of eye position signals during spontaneous eye movements but not during the VOR.Fondo de Investigación Sanitaria Grants 94/0388 and 97/2054Comunidad Autónoma de Madrid Grant 08.5/0019/1997Dirección General de Investigación Científica y Technológica Grant PB 93–117

Potential Growth and Business Cycle in the Spanish Economy: Implications for Fiscal Policy

An accurately estimation of the cyclical position of an economy is a necessary condition for the success of fiscal stabilisation policies. In this paper we show that the estimation of the output gap by means of decomposing a production function produces similar results to univariate and multivariate methods, increasing their robustness and allowing us to conclude that most of the information on the economic cycle is included in the cyclical component of the unemployment rate. The results also indicate that there is reduced uncertainty about the periods when the Spanish economy has clearly been in a deep recession or in a sharp expansion. These periods have been limited and of relatively short duration. Fiscal policy should pay particular attention to these episodes, when discretionary stabilisation policies make most sense.potential growth, business cycle, speed-limit policies

Discusión del término "innovación social": ambigüedad del término y elementos para una propuesta de definición estipulativa

El presente artículo trata en una primera parte lo concerniente al estado del arte, donde se presentarán nueve definiciones del término “innovación social” -- Segundo, se compararán y se mostrarán las características de ambigüedad, difusividad, nociones abstractas, indeterminación y contradicciones entre estas definiciones -- En tercer lugar, se introduce la teoría de la argumentación como herramienta de análisis para identificar los aspectos positivos y las debilidades de las definiciones anteriores, así como el método de disociación de nociones, como herramienta de clarificación teórica -- En cuarto lugar, con base en esa teoría, se discuten las características señaladas en la segunda parte, aplicando la teoría de la argumentación -- Finalmente, como conclusión se presenta una propuesta de definición estipulativa de innovación socia

A Brief Note on Béziau’s “Rather Trivial Theorem” About LP

Béziau has recently argued that the logic LP commits dialetheists to trivialism and Martin has pointed out very clearly the main problems with that alleged result. My sole purpose here is to make the spirit of Martin’s reply more concise, exhibiting as clearly as possible the logical defects in Béziau’s reasoning. Additionally, I want to make some remarks on LP qua logic and not only as an interpreted language

Models of possibilism and trivialism

In this paper I probe the idea that neither possibilism nor trivialism could be ruled out on a purely logical basis. I use the apparatus of relational structures used in the semantics for modal logics to engineer some models of possibilism and trivialism and I discuss a philosophical stance about logic, truth values and the meaning of connectives underlying such analysis

The Effects of Diversification on Banks’ Expected Returns

In financial theory, the optimal allocation of assets and its relationship with profitability has been one of the main concerns; the question has always been if banks should focus or diversify their assets. In our case, we would like to answer this question focusing in diversification of the loan portfolio, presenting a theoretical model that considers the possible gains from diversification, while taking in to account the effects of monitoring. Additionally, we present empirical evidence on this matter for the Colombian banking system. According to the model, we find that once the banks have chosen its optimal level of monitoring, expected return is always higher when the bank decides to focus. Additionally, the empirical results suggest that there are no possible gains form diversification in bank’s cost and that, on average, the effects of focusing the loan portfolio reduces bank’s return while showing positive effects of focusing on an specific sector.Diversification, Risk, Colombian Banking System. Classification JEL: G00; G21; G30.

La profesionalización de los órganos electorales en México, el caso del Instituto Federal Electoral

Esta investigación tiene como objeto de estudio el Servicio Profesional Electoral en México, en particular en el Instituto Federal Electoral (2008-2012); indagamos su contenido para saber sus posibilidades como modelo orientador para otras instituciones públicas. Hay un reconocimiento en la literatura especializada y en opinión pública que la profesionalización del servicio público es un tema relevante en la agenda de la modernización de las instituciones. Sin embargo es pertinente preguntarse por los problemas públicos que pretende resolver la profesionalización en la función pública. Incluso cada que surge una controversia con respecto a la calidad del servicio de parte de los organismos gubernamentales se recurre al tópico de la preparación/habilidades profesionales de los servidores públicos. Por si fuera poco, es un punto de debate cotidiano en la sociedad, quien encuentra en el servidor público un enemigo más que un aliado

Micromechanical approach for the analysis of wave propagation in particulate composites

Laser ultrasonic non-destructive testing is widely used for the inspection of mechanical structures. This method uses the propagation of ultrasonic guided waves (UGW) in the media. For this purpose, it has been demonstrated that the addition of a thin composite layer between the laser source and the structure for inspection is necessary. Consequently, this composite is an optoacoustic transducer composed of an absorption material such as carbon for inclusions and an expanding material such as an elastomer for the matrix. Thus, optimal fabrication of this composite should enable the amplification of the signal for inspection. Indeed, experimental research has demonstrated that variation in the volume fraction of carbon inclusions, their shape, and the nature of the matrix, affect the amplification of the signal directly. The aim of this study is to analyse the wave propagation in particulate viscoelastic composites by a dynamic self-consistent approach

Análisis operacional del departamento de hidrotratamiento de Reficar S.A

ECOPETROL S.A. se encarga de la exploración, producción transporte, refinación y comercialización del petróleo y sus derivados.1 Es una compañía que está comprometida con su entorno, el ambiente y el país y la base de su organización es el talento humano de todos sus trabajadores. ECOPETROL S.A. es la primera compañía de petróleo de Colombia, en la cual no solo se extrae el petróleo sino que también se le hace un tratamiento al mismo, en las refinerías de Barrancabermeja y Cartagena (REFICAR S.A). Siendo de esta manera REFICAR S.A, la refinería más moderna de Latinoamérica, (Figura 1) donde se procesa el crudo para entregar combustibles limpios y amigables con el medio ambiente. La refinería de Cartagena es un complejo industrial integro, donde todas sus plantas están interconectadas entre sí, y los procesos dependen uno del otro para así conseguir su meta de entregar energía para el futuro sustentable y sostenible. Para que esto pueda ser posible, REFICAR S.A cuenta con un grupo de personas capacitadas para realizar seguimiento y control a todo el funcionamiento de la compañía, en este caso este artículo, trata del principal trabajo realizado en esta empresa que fue ejecutar un seguimiento y control de la energía que se consume en uno de los departamentos de la refinería, y por otro lado, realizarle un seguimiento a los productos que se reciben y salen de cada unidad, ya sean productos fuera de especificación o productos terminados y listos para su venta y distribución