Louis I. Kahn. Parasol Houses

Con ocasión del reciente centenario de Louis I. Kahn, su figura y trayectoria profesional han vuelto a ser objeto de estudios y análisis. Tal es el caso de la elegante monografía de Robert McCarter publicada por Phaidon en el 2004, o la sorprendente película, My Architect: A Son’s Journey, documental nominado para los Óscar 2004, realizado por su hijo Nathaniel Kahn, en el que intenta indagar en el personaje que apenas llegó a conocer. Poco nuevo se puede decir sobre sus obras construidas, sobre sus edificios para las grandes instituciones o sobre sus viviendas. Sin embargo, el amplio registro gráfico de sus planos y dibujos, publicado en la Garland Architecture Archives, aún permite un acercamiento a su obra intentando indagar en algunos aspectos poco conocidos de su trabajo, como pueden ser los procesos proyectuales de algunos encargos que no llegarían a materializarse. Este artículo aborda uno de esos proyectos, las viviendas conocidas como las Parasol Houses, quizá una de las primeras obras en las que se dejan ver las inquietudes formales –la geometría, el orden, la estructura– acometidas por Kahn a partir de la década de los cincuenta

Diseño de un modelo de datos de redes para el transporte multimodal

Esta comunicación tiene por objeto el análisis de las relaciones entre redes de transporte y paisaje. Se aborda el análisis de la estructura de la red y su caracterización, para dar soporte a la modelización de distintos escenarios, lo que implica un complejo modelo de datos en el que se trabaja con una red multimodal conformada por los siguientes modos: transporte por carretera, ferroviario, peatonal y náutico. Se hace hincapié en el transporte combinado que emplea los diferentes modos, como ocurre frecuentemente con el viaje turístico. El territorio en el que se construye el modelo, a partir de los mapas topográficos 1:5000 y 1.000, que se complementan con ortofotografía, es la isla de Tenerife.This paper explores the relationship between transport networks and landscape. The network structure and its characteristics are studied in order to support the modeling of different scenarios. This implies a complex data model which works with a multimodal network. It is composed by different features: roads, railroads, pedestrian paths and nautical tracks. A combined transport system (the touristic travel) employing different modalities is the focus of interest. Tenerife Island acts as a reference of this transport system. Base maps in 1:5000 and 1:1000 scales and a rectified photo are used

The role of metabolic remodeling in macrophage polarization and its effect on skeletal muscle regeneration

Macrophages are crucial for tissue homeostasis. Based on their activation, they might display classical/M1 or alternative/M2 phenotypes. M1 macrophages produce pro-inflammatory cytokines, reactive oxygen species (ROS), and nitric oxide (NO). M2 macrophages upregulate arginase-1 and reduce NO and ROS levels; they also release anti-inflammatory cytokines, growth factors, and polyamines, thus promoting angiogenesis and tissue healing. Moreover, M1 and M2 display key metabolic differences; M1 polarization is characterized by an enhancement in glycolysis and in the pentose phosphate pathway (PPP) along with a decreased oxidative phosphorylation (OxPhos), whereas M2 are characterized by an efficient OxPhos and reduced PPP. Recent Advances: The glutamine-related metabolism has been discovered as crucial for M2 polarization. Vice versa, flux discontinuities in the Krebs cycle are considered additional M1 features; they lead to increased levels of immunoresponsive gene 1 and itaconic acid, to isocitrate dehydrogenase 1-downregulation and to succinate, citrate, and isocitrate over-expression

A metaphylactic treatment with double dose oxytetracycline reduces the risk of bovine respiratory disease in feedlot calves

El objetivo del presente estudio fue evaluar el efecto del tratamiento metafiláctico con oxitetraciclina (OTC), a simple y doble dosis, en bovinos con alto riesgo de padecer enfermedad respiratoria bovina (ERB). El estudio se realizó en un establecimiento de engorde a corral donde se utilizaron 2.754 terneros que fueron considerados de alto riesgo de padecer ERB. Se utilizó un diseño en bloque completamente al azar donde se consideró al animal como la unidad experimental y el corral (n=10) como bloque. Se formaron tres grupos experimentales: 1- control (CTL) el cual permaneció sin tratamiento, 2- recibió OTC 20 mg/kg SC (OTC20) y 3- recibió OTC 40 mg/kg SC (OTC40). El riesgo de ERB fue evaluado a través de una regresión logística. Los animales del grupo CTL tuvieron 2,85 y 7,14 veces más chances de enfermarse de ERB que los animales de los grupos OTC20 y OTC40 respectivamente (

Stimulation of endothelial progenitor cells: a new putative effect of several cardiovascular drugs

The role of vascular endothelium in cardiovascular disorders is well recognized. Mature endothelial cells contribute to the repair of endothelial injury, but they only have a limited capacity to do so. This has led to growing interest and further investigation into circulating endothelial progenitor cells (EPCs) and their role in vascular healing, repair, and postnatal neovascularization. The current perception of vascular health is that of a balance between ongoing injury and resultant vascular repair, mediated at least in part by circulating EPCs. Circulating EPCs play an important role in accelerating endothelialization at areas of vascular damage, and EPC enumeration is a viable strategy for assessing reparative capacity. Recent studies have shown that EPCs are affected both in number and function by several cardiovascular risk factors as well as various cardiovascular disease states, such as hypertension, hypercholesterolemia, and coronary artery disease. The present review summarizes the most relevant studies on the effects of cardiovascular drugs on vascular function and EPCs, focusing on their mechanisms of action

Phase Transition in a Random Fragmentation Problem with Applications to Computer Science

We study a fragmentation problem where an initial object of size x is broken into m random pieces provided x>x_0 where x_0 is an atomic cut-off. Subsequently the fragmentation process continues for each of those daughter pieces whose sizes are bigger than x_0. The process stops when all the fragments have sizes smaller than x_0. We show that the fluctuation of the total number of splitting events, characterized by the variance, generically undergoes a nontrivial phase transition as one tunes the branching number m through a critical value m=m_c. For m<m_c, the fluctuations are Gaussian where as for m>m_c they are anomalously large and non-Gaussian. We apply this general result to analyze two different search algorithms in computer science.Comment: 5 pages RevTeX, 3 figures (.eps

Comparing Young Massive Clusters and their Progenitor Clouds in the Milky Way

Young massive clusters (YMCs) have central stellar mass surface densities exceeding $10^{4} M_{\odot} pc^{-2}$. It is currently unknown whether the stars formed at such high (proto)stellar densities. We compile a sample of gas clouds in the Galaxy which have sufficient gas mass within a radius of a few parsecs to form a YMC, and compare their radial gas mass distributions to the stellar mass distribution of Galactic YMCs. We find that the gas in the progenitor clouds is distributed differently than the stars in YMCs. The mass surface density profiles of the gas clouds are generally shallower than the stellar mass surface density profiles of the YMCs, which are characterised by prominent dense core regions with radii ~ 0.1 pc, followed by a power-law tail. On the scale of YMC core radii, we find that there are no known clouds with significantly more mass in their central regions when compared to Galactic YMCs. Additionally, we find that models in which stars form from very dense initial conditions require surface densities that are generally higher than those seen in the known candidate YMC progenitor clouds. Our results show that the quiescent, less evolved clouds contain less mass in their central regions than in the highly star-forming clouds. This suggests an evolutionary trend in which clouds continue to accumulate mass towards their centres after the onset of star formation. We conclude that a conveyor-belt scenario for YMC formation is consistent with the current sample of Galactic YMCs and their progenitor clouds