IMPLEMENTACIÓN EN SIMUL8 DE UN MODELO SOBRE LOS DEPARTAMENTO DE ACCIDENTES Y EMERGENCIAS

Los departamentos de accidentes y emergencias son de gran interés en el área de la simulación de eventos discretos ya que por la importancia de los servicios que prestan se hace apremiante encontrar alternativas que hagan que su rendimiento en cuanto a tiempos de atención sea lo más óptimo posibles. En este trabajo se implementa en el software Simul8 un modelo genérico desarrollado por Günal y Pidd (2006) sobre estos departamentos con el fin de comprender el funcionamiento de estos sistemas y obtener respuestas de investigación sobre la implementación de modelos genéricos y la pertinencia de la simulación de eventos discretos para este tipo de sistemas.The departments of accidents and emergencies are very interesting in simulation and discrete events areas because the importance of the services that they give became important to find alternatives to make their performance in time attention the most optimal. In this work it’s carried out in the software Simul8 a generic model developed by Günal y Pidd (2006) about these departments in order to understand the performance of these systems and to get research answers about the carrying out of generic models and the relevance of simulation of discrete events for this kind of systems

The fractional Keller-Segel model

The Keller-Segel model is a system of partial differential equations modelling chemotactic aggregation in cellular systems. This model has blowing up solutions for large enough initial conditions in dimensions d >= 2, but all the solutions are regular in one dimension; a mathematical fact that crucially affects the patterns that can form in the biological system. One of the strongest assumptions of the Keller-Segel model is the diffusive character of the cellular motion, known to be false in many situations. We extend this model to such situations in which the cellular dispersal is better modelled by a fractional operator. We analyze this fractional Keller-Segel model and find that all solutions are again globally bounded in time in one dimension. This fact shows the robustness of the main biological conclusions obtained from the Keller-Segel model

Specific heat studies of pure Nb3Sn single crystals at low temperature

Specific heat measurements performed on high purity vapor-grown Nb$_3$Sn crystals show clear features related to both the martensitic and superconducting transitions. Our measurements indicate that the martensitic anomaly does not display hysteresis, meaning that the martensitic transition could be a weak first or a second order thermodynamic transition. Careful measurements of the two transition temperatures display an inverse correlation between both temperatures. At low temperature specific heat measurements show the existence of a single superconducting energy gap feature.Comment: Accepted in Journal of Physics: Condensed Matte

Chemotactic Collapse and Mesenchymal Morphogenesis

We study the effect of chemotactic signaling among mesenchymal cells. We show that the particular physiology of the mesenchymal cells allows one-dimensional collapse in contrast to the case of bacteria, and that the mesenchymal morphogenesis represents thus a more complex type of pattern formation than those found in bacterial colonies. We finally compare our theoretical predictions with recent in vitro experiments

Reply to "Comment on 'Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy'"

We appreciate the interest of Dr Tang in our article. Certainly, our previous results should be taken with caution due to the small database size. Nevertheless, it must be noted that this limitation was clearly recognized in our article. Furthermore, our hypothesis is completely justified from the current state of the art in the analysis of electroencephalogram (EEG) signals from Alzheimer's disease (AD) patients. We evaluated whether the multiscale entropy (MSE) analysis of the EEG background activity was useful to distinguish AD patients and controls. We do believe that further discussions about risk factors or related clinicophysiological protein aspects are clearly beyond the scope of our article. For the sake of completeness, we now detail some results that complement our previous analysis. They suggest that the MSE analysis can provide relevant information about the dynamics of AD patients' EEG data. Thus, we must reaffirm our conclusions, although we again acknowledge that further studies are needed

Physical activity and smoking habit in adolescent students

El objetivo de este estudio fue detectar en qué medida afecta la actividad física y el hábito tabáquico en estudiantes de Enseñanza Secundaria. Se estudiaron 168 adolescentes no fumadores y fumadores recién iniciados. Se midieron peso, talla, presión arterial, frecuencia cardíaca, actividad física, fuerza, flexibilidad y resistencia y una prueba espirométrica. Tanto en chicas y chicos fumadores, se evidenciaron peores resultados en la mayoría de los parámetros espirométricos (FEV1, FEF25-75%, FVC) y un envejecimiento prematuro del pulmón, más acentuado en chicas. La actividad físico-deportiva moderada se asocia a adolescentes que menos fuman y tienen más facilidad para abandonar el hábito tabáquicoThe aim of the study was to detect how physical education and smoking habits affect secondary school students, 168 non smokers and newly initiated were studied. Weight, height, heart rate, blood pressure, physical activity, strength, flexibility and endurance, and spirometric tests were analyzed. In both, female and male smokers, obtained worse results in the mayority of spirometric parameters (FEV1, FEF25-75%, FVC) and premature lung ageing, more pointed in females. Moderate physical-sporting activity is associated to adolescents who smoke less and quit smoking more easil

Analysis of electroencephalograms in Alzheimer's disease patients with multiscale entropy

The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer’s disease (AD) patients using the Multiscale Entropy (MSE). The MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant difference

Mechanisms of Endothelial Dysfunction in Antiphospholipid Syndrome: Association With Clinical Manifestations

The endothelium is a monolayer of cells that covers the inner surface of blood vessels and its integrity is essential for the maintenance of vascular health. Endothelial dysfunction is a key pathological component of antiphospholipid syndrome (APS). Its systemic complications include thrombotic endocarditis, valvular dysfunction, cerebrovascular occlusions, proliferative nephritis, deep vein thrombosis, and pulmonary embolism. In women, APS is also associated with pregnancy complications (obstetric APS). The conventional treatment regimens for APS are ineffective when the clinical symptoms are severe. Therefore, a better understanding of alterations in the endothelium caused by antiphospholipid antibodies (aPL) may lead to more effective therapies in patients with elevated aPL titers and severe clinical symptoms. Currently, while in vivo analyses of endothelial dysfunction in patients with APS have been reported, most research has been performed using in vitro models with endothelial cells exposed to either patient serum/plasma, monoclonal aPL, or IgGs isolated from patients with APS. These studies have described a reduction in endothelial cell nitric oxide synthesis, the induction of inflammatory and procoagulant phenotypes, an increase in endothelial proliferation, and impairments in vascular remodeling and angiogenesis. Despite these lines of evidence, further research is required to better understand the pathophysiology of endothelial dysfunction in patients with APS. In this review, we have compared the current understanding about the mechanisms of endothelial dysfunction induced by patient-derived aPL under the two main clinical manifestations of APS: thrombosis and gestational complications, either alone or in combination. We also discuss gaps in our current knowledge regarding aPL-induced endothelial dysfunction