Anticipatory freight selection in intermodal long-haul round-trips

We consider the planning problem faced by Logistic Service Providers (LSPs) transporting freights periodically, using long-haul round-trips. In each round-trip, freights are delivered and picked up at different locations within one region. Freights have time-windows and become known gradually over time. Using probabilistic knowledge about future freights, the LSP’s objective is to minimize costs over a multi-period horizon. We propose a look-ahead planning method using Approximate Dynamic Programming. Experiments show that our approach reduces costs up to 25.5% compared to a single-period optimization approach. We provide managerial insights for several intermodal long-haul round-trips settings and provide directions for further research

Childhood acute leukemias are frequent in Mexico City: descriptive epidemiology

<p>Abstract</p> <p>Background</p> <p>Worldwide, acute leukemia is the most common type of childhood cancer. It is particularly common in the Hispanic populations residing in the United States, Costa Rica, and Mexico City. The objective of this study was to determine the incidence of acute leukemia in children who were diagnosed and treated in public hospitals in Mexico City.</p> <p>Methods</p> <p>Included in this study were those children, under 15 years of age and residents of Mexico City, who were diagnosed in 2006 and 2007 with leukemia, as determined by using the International Classification of Childhood Cancer. The average annual incidence rates (AAIR), and the standardized average annual incidence rates (SAAIR) per million children were calculated. We calculated crude, age- and sex-specific incidence rates and adjusted for age by the direct method with the world population as standard. We determined if there were a correlation between the incidence of acute leukemias in the various boroughs of Mexico City and either the number of agricultural hectares, the average number of persons per household, or the municipal human development index for Mexico (used as a reference of socio-economic level).</p> <p>Results</p> <p>Although a total of 610 new cases of leukemia were registered during 2006-2007, only 228 fit the criteria for inclusion in this study. The overall SAAIR was 57.6 per million children (95% CI, 46.9-68.3); acute lymphoblastic leukemia (ALL) was the most frequent type of leukemia, constituting 85.1% of the cases (SAAIR: 49.5 per million), followed by acute myeloblastic leukemia at 12.3% (SAAIR: 6.9 per million), and chronic myeloid leukemia at 1.7% (SAAIR: 0.9 per million). The 1-4 years age group had the highest SAAIR for ALL (77.7 per million). For cases of ALL, 73.2% had precursor B-cell immunophenotype (SAAIR: 35.8 per million) and 12.4% had T-cell immunophenotype (SAAIR 6.3 per million). The peak ages for ALL were 2-6 years and 8-10 years. More than half the children (58.8%) were classified as high risk. There was a positive correlation between the average number of persons per household and the incidence of the pre-B immunophenotype (Pearson's r, 0.789; P = 0.02).</p> <p>Conclusions</p> <p>The frequency of ALL in Mexico City is among the highest in the world, similar to those found for Hispanics in the United States and in Costa Rica.</p

Global human footprint on the linkage between biodiversity and ecosystem functioning in reef fishes

Copyright: © 2011 Mora et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Difficulties in scaling up theoretical and experimental results have raised controversy over the consequences of biodiversity loss for the functioning of natural ecosystems. Using a global survey of reef fish assemblages, we show that in contrast to previous theoretical and experimental studies, ecosystem functioning (as measured by standing biomass) scales in a non-saturating manner with biodiversity (as measured by species and functional richness) in this ecosystem. Our field study also shows a significant and negative interaction between human population density and biodiversity on ecosystem functioning (i.e., for the same human density there were larger reductions in standing biomass at more diverse reefs). Human effects were found to be related to fishing, coastal development, and land use stressors, and currently affect over 75% of the world's coral reefs. Our results indicate that the consequences of biodiversity loss in coral reefs have been considerably underestimated based on existing knowledge and that reef fish assemblages, particularly the most diverse, are greatly vulnerable to the expansion and intensity of anthropogenic stressors in coastal areas

La plaza pública

1 archivo PDF (269 páginas) : incluye ilustraciones"El interés central de la publicación radica en discutir sobre la crisis de la “ciudad” o de la “urbanidad” que se manifiesta con más fuerza en el espacio público, ya que actualmente existen formas que obstaculizan el contacto; esto es, la relación entre personas y entre actividades dentro del espacio urbano. Algunos autores han insinuado que el espacio público está condenado a la irrelevancia, de manera que incluso plantean la existencia de los llamados “no lugares” que no están vinculados a algún sitio específico. ...

4to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

Este volumen acoge la memoria académica de la Cuarta edición del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2017, desarrollado entre el 29 de noviembre y el 1 de diciembre de 2017 y organizado por la Universidad Politécnica Salesiana (UPS) en su sede de Guayaquil. El Congreso ofreció un espacio para la presentación, difusión e intercambio de importantes investigaciones nacionales e internacionales ante la comunidad universitaria que se dio cita en el encuentro. El uso de herramientas tecnológicas para la gestión de los trabajos de investigación como la plataforma Open Conference Systems y la web de presentación del Congreso http://citis.blog.ups.edu.ec/, hicieron de CITIS 2017 un verdadero referente entre los congresos que se desarrollaron en el país. La preocupación de nuestra Universidad, de presentar espacios que ayuden a generar nuevos y mejores cambios en la dimensión humana y social de nuestro entorno, hace que se persiga en cada edición del evento la presentación de trabajos con calidad creciente en cuanto a su producción científica. Quienes estuvimos al frente de la organización, dejamos plasmado en estas memorias académicas el intenso y prolífico trabajo de los días de realización del Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad al alcance de todos y todas

Integrated scheduling of drayage and long-haul operations in synchromodal transport

We study the problem of the integrated scheduling of drayage operations and long-haul transport in synchromodality. Although different in time span and characteristics of execution, these two processes have an impact on each other and their interaction has a direct influence on the overall performance of the transport network over time. We propose a simulation based integration of a Mixed-Integer Linear Programming model for the drayage operations and a Markov Decision Process model for the long-haul transport. We analyze the interfaces between these models, outline the challenges of integrating them, and design a heuristic approach to the simulation based integration. In a series of numerical experiments, we evaluate the cost savings compared to a non-integrated approach, using various transport network configurations. We show that our approach achieves average cost savings between 4 and 24% on networks with a majority of pre-haulage freights. Furthermore, we discuss limitations of our model and experiments, and provide guidelines for further research for the integrated scheduling of drayage and long-haul operations in synchromodal transport

Anticipatory freight selection in intermodal long-haul round-trips

We consider the planning problem faced by Logistic Service Providers (LSPs) transporting freights periodically, using long-haul round-trips. In each round-trip, freights are delivered and picked up at different locations within one region. Freights have time-windows and become known gradually over time. Using probabilistic knowledge about future freights, the LSP’s objective is to minimize costs over a multi-period horizon. We propose a look-ahead planning method using Approximate Dynamic Programming. Experiments show that our approach reduces costs up to 25.5% compared to a single-period optimization approach. We provide managerial insights for several intermodal long-haul round-trips settings and provide directions for further research

Biopsia endomiocárdica por vía venosa braquial.: Descripción de la técnica y experiencia en 12 años de 2 centros

ABSTRACT Introduction and objectives: Recipients of a heart transplant need to receive serial endomyocardial biopsies (EMB) to discard rejection, a procedure that is usually performed through the femoral or jugular vein. Over the last few years, we have developed a technique to perform EMBs using the brachial venous access that we have implemented as the preferential access route. In this article, we describe the technique and the initial clinical experience of 2 different centers. Methods: Between 2004 and 2016, we developed and implemented a brachial venous access technique. We registered the main clinical and procedural variables of all the brachial biopsies performed in both centers and compared them with a retrospective series of femoral and jugular procedures. Results: Brachial EMBs were successfully performed 544 of the time with no major complications. The number of brachial procedures per patient rose from 1 to 14. Over the same period of time 1054 femoral and 686 jugular procedures were performed. The total procedural time was similar with different access routes (mean for brachial/femoral/jugular access: 28/26/29 min., P = .31) while fluoroscopy time was shorter in jugular procedures (mean 5/5/3 min. respectively; P < .001). The brachial procedure was recalled as the least painful procedure of all compared to the jugular or femoral ones (2/8/9 score on a scale from 1 to 10; P = .001) with an overall patient preference towards the brachial access. Conclusions: The venous brachial access route is a good alternative to the central venous one to perform EMBs and is the route of choice in our centers. Also, it has high feasibility and safety and brings additional comfort to patients.Introducción y objetivos: Los pacientes receptores de un trasplante cardiaco necesitan someterse a biopsias endomiocárdicas (BEM) para descartar el rechazo, procedimiento que habitualmente se realiza por acceso venoso yugular o femoral. En los últimos años hemos desarrollado una técnica de biopsia por vía braquial, que hemos implementado como acceso preferente. En este artículo describimos la técnica y la experiencia clínica inicial de 2 centros empleando el acceso braquial. Métodos: Entre 2004 y 2016 desarrollamos e implementamos la técnica de biopsia por vía venosa braquial. Se registraron las principales variables clínicas y del procedimiento de todas las BEM realizadas por vía braquial en ambos centros, y se compararon las características con los procedimientos realizados por vía femoral y yugular. Resultados: Se realizó la BEM por vía braquial en 544 casos, sin complicaciones mayores. El número de procedimientos braquiales por paciente varió entre 1 y 14. En el mismo periodo se realizaron 1.054 BEM femorales y 686 yugulares. La duración total del procedimiento fue similar por los distintos accesos (mediana braquial/femoral/yugular: 28/26/29 min; p = 0,31), con un menor tiempo de escopia por vía yugular (mediana 5/5/3 min, respectivamente; p < 0,001). Los procedimientos realizados por vía braquial se valoraron como menos dolorosos que los realizados por vía yugular o femoral (2/8/9 en la escala de dolor EVA de 1-10, respectivamente; p = 0,001), y fue la vía de elección por parte de los pacientes. Conclusiones: La BEM por vía venosa braquial es una buena alternativa a la punción venosa central y la vía de elección en nuestros centros, con altas factibilidad y seguridad, y mayor comodidad para el paciente