Improved γ\gamma/hadron separation for the detection of faint gamma-ray sources using boosted decision trees

Imaging atmospheric Cherenkov telescopes record an enormous number of cosmic-ray background events. Suppressing these background events while retaining $\gamma$-rays is key to achieving good sensitivity to faint $\gamma$-ray sources. The differentiation between signal and background events can be accomplished using machine learning algorithms, which are already used in various fields of physics. Multivariate analyses combine several variables into a single variable that indicates the degree to which an event is $\gamma$-ray-like or cosmic-ray-like. In this paper we will focus on the use of boosted decision trees for $\gamma$/hadron separation. We apply the method to data from the Very Energetic Radiation Imaging Telescope Array System (VERITAS), and demonstrate an improved sensitivity compared to the VERITAS standard analysis.Comment: accepted for publication in Astroparticle Physic

Natural Fiber-Polypropylene composites made from caranday palm

Composites made from polypropylene (PP) and local South American fi bers traditionally used in yarnderived craftsmanships, Caranday Palm, were studied regarding the effect of fi ber addition, concentration and characteristics of the coupling agent (molecular weight and percentage of grafted maleic anhydride), as well as type of processing. A laboratory-scale intensive mixing followed by compression, and pilot plant twin extrusion followed by injection, were the two processes investigated. The use of the fi rst one allowed the selection of processable formulations with high fi ber concentration and a percentage of coupling agent below the surface fi ber saturation. In fact, it was found that there is a concentration of maleic anhydride moieties that saturates the surface of the fi ber irrespective of the agent molecular weight. Increasing the concentration of the coupling agent above that value does not produce further improvement of the mechanical properties. The formulations selected from the results of the laboratory process were considered for the pilot plant (extrusioninjection) process. The use of the second process consisting of extrusion-injection molding showed that the high shear developed in this process leads to defi brillation of the fi ber bundles. In the case of the Caranday Palm fi bers, this defi brillation resulted in elemental fi bers (micron size) being the effective reinforcement of the composite instead of the technical fi bers (millimeter size) that were present in the composites prepared by compression. Better mechanical properties were achieved by using the latter method.Fil: Samartino, Estela Krause. Instituto Nacional de Tecnología Industrial. Centro de Plástico; ArgentinaFil: Reboredo, Maria Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Aranguren, Mirta Ines. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

High energy astroparticle physics for high school students

The questions about the origin and type of cosmic particles are not only fascinating for scientists in astrophysics, but also for young enthusiastic high school students. To familiarize them with research in astroparticle physics, the Pierre Auger Collaboration agreed to make 1% of its data publicly available. The Pierre Auger Observatory investigates cosmic rays at the highest energies and consists of more than 1600 water Cherenkov detectors, located near Malarg\"{u}e, Argentina. With publicly available data from the experiment, students can perform their own hands-on analysis. In the framework of a so-called Astroparticle Masterclass organized alongside the context of the German outreach network Netzwerk Teilchenwelt, students get a valuable insight into cosmic ray physics and scientific research concepts. We present the project and experiences with students.Comment: 8 pages, 5 figures, Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands, PoS(ICRC2015)30

Fazer educaçao do espírito com Paul Valéry

O texto-ensaio FAZER EDUCAÇAO DO ESPIRITO COM PAUL VALERY investiga o fazer múltiplo de uma criatura de pensamento, o escritor Paul Valéry. O texto atua e opera uma comédia do espírito, através de um método do informe, em cruzamentos imaginativos, com a filosofia, com a literatura e com a educaçao. A escrita, que opera com a leitura -escrileitura- é aqui tratada a partir da perspectiva valéryana, pesquisa um meio possível para um proceder potente em educaçao. A escrileitura é vista como uma atividade espiritual possível e permissiva às operaçoes de consciência para ampliar o uso das faculdades intelectivas, com vistas a uma educaçao espiritual potente, oriundas de uma self-variance disciplinada e rigorosa. Este fazer corpo-espírito- mundo; produz tipos de personagens, extraídos de espiritografias de produçao singular, que cultuam o intelecto na busca do Eu puro -senhor de si- e transitam aventureiramente por diversas áreas do saber. Sao arquiteturas de um Método que busca experimentar, movimentar pensamentos, utilizando o conhecimento como invençao para um fazer compositivo de escrita e com eles produzir meios, para possibilidades criadoras em educaçao. Estas operaçoes de método do informe têm suas experimentaçoes e pesquisas cultivadas dentro do projeto Escrileituras: um modo de ler-escrever em meio à vida do Observatório da Educaçao/CAPES/INEP - 2010. Terreno fértil e aberto ao esforço da criaçao, à variaçao espiritual, onde o serpensamento transforma-se e arrisca um novo olhar diante do espetáculo do mundo; para assim dizer- se, autoeducar-se, explorando as potências da linguagem dentro de um processo de escrileitura

Barreiras à implementação de práticas de sustentabilidade ambiental na logística da última milha no e-commerce

TCC(graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia de ProduçãoCom a introdução do e-commerce, a logística de entrega urbana de mercadorias foi impactada e tornou-se mais complexa. Com isso, a necessidade de expandir práticas logísticas ambientalmente sustentáveis tornou-se um assunto emergente dentro da literatura e entre as grandes empresas que buscam se manter no mercado. Entretanto, são muitas as barreiras enfrentadas pelas empresas que anseiam implementar uma logística de última milha mais sustentável no âmbito ambiental. Sendo assim, este trabalho tem o objetivo de identificar as principais barreiras para a implementação de práticas de sustentabilidade ambiental na logística de última milha encontradas por empresas de e-commerce. Para isso, foi realizada uma revisão sistemática da literatura por meio de uma busca com o uso de palavras-chave e estruturada através da metodologia PRISMA, onde 40 artigos foram selecionados. Os resultados obtidos foram a identificação das barreiras na literatura definida e um framework conceitual. Ao todo foram apontadas 39 barreiras, sendo elas organizadas em quatro categorias: ‘gestão’, ‘armazenagem, separação de pedidos e embalagens’, ‘transporte’ e ‘entrega’. Portanto, este trabalho tem relevância ao contribuir para a literatura, com o estudo de um tema emergente, e para as empresas, ao destacar os principais problemas que necessitam de soluções

Feasibility of transesophageal phrenic nerve stimulation

Background Every year, more than 2.5 million critically ill patients in the ICU are dependent on mechanical ventilation. The positive pressure in the lungs generated by the ventilator keeps the diaphragm passive, which can lead to a loss of myofibers within a short time. To prevent ventilator-induced diaphragmatic dysfunction (VIDD), phrenic nerve stimulation may be used. Objective The goal of this study is to show the feasibility of transesophageal phrenic nerve stimulation (TEPNS). We hypothesize that selective phrenic nerve stimulation can efficiently activate the diaphragm with reduced co-stimulations. Methods An in vitro study in saline solution combined with anatomical findings was performed to investigate relevant stimulation parameters such as inter-electrode spacing, range to target site, or omnidirectional vs. sectioned electrodes. Subsequently, dedicated esophageal electrodes were inserted into a pig and single stimulation pulses were delivered simultaneously with mechanical ventilation. Various stimulation sites and response parameters such as transdiaphragmatic pressure or airway flow were analyzed to establish an appropriate stimulation setting. Results Phrenic nerve stimulation with esophageal electrodes has been demonstrated. With a current amplitude of 40 mA, similar response figures of the diaphragm activation as compared to conventional stimulation with needle electrodes at 10mA were observed. Directed electrodes best aligned with the phrenic nerve resulted in up to 16.9 % higher amplitude at the target site in vitro and up to 6 cmH20 higher transdiaphragmatic pressure in vivo as compared to omnidirectional electrodes. The activation efficiency was more sensitive to the stimulation level inside the esophagus than to the inter-electrode spacing. Most effective and selective stimulation was achieved at the level of rib 1 using sectioned electrodes 40 mm apart. Conclusion Directed transesophageal phrenic nerve stimulation with single stimuli enabled diaphragm activation. In the future, this method might keep the diaphragm active during, and even support, artificial ventilation. Meanwhile, dedicated sectioned electrodes could be integrated into gastric feeding tubes

DockGame: Cooperative Games for Multimeric Rigid Protein Docking

Protein interactions and assembly formation are fundamental to most biological processes. Predicting the assembly structure from constituent proteins -- referred to as the protein docking task -- is thus a crucial step in protein design applications. Most traditional and deep learning methods for docking have focused mainly on binary docking, following either a search-based, regression-based, or generative modeling paradigm. In this paper, we focus on the less-studied multimeric (i.e., two or more proteins) docking problem. We introduce DockGame, a novel game-theoretic framework for docking -- we view protein docking as a cooperative game between proteins, where the final assembly structure(s) constitute stable equilibria w.r.t. the underlying game potential. Since we do not have access to the true potential, we consider two approaches - i) learning a surrogate game potential guided by physics-based energy functions and computing equilibria by simultaneous gradient updates, and ii) sampling from the Gibbs distribution of the true potential by learning a diffusion generative model over the action spaces (rotations and translations) of all proteins. Empirically, on the Docking Benchmark 5.5 (DB5.5) dataset, DockGame has much faster runtimes than traditional docking methods, can generate multiple plausible assembly structures, and achieves comparable performance to existing binary docking baselines, despite solving the harder task of coordinating multiple protein chains.Comment: Under Revie

Sentidos, motivaciones, estrategias y barreras vinculadas con la realización de actividades físicas y deportes entre sectores de clase media del AMBA

En esta ponencia presentamos resultados preliminares de un proyecto UBACyT en el que indagamos sobre diversas prácticas preventivas asociadas a hábitos de vida normativamente considerados como saludables. Enmarcamos nuestro estudio en un contexto socio cultural que enfatiza la responsabilidad individual en el cuidado de la salud, especialmente en los aspectos preventivos, a través del desarrollo de estilos de vida saludables. Nos preguntamos sobre los motivos por los que los sujetos realizan actividad física y deporte, los sentidos que le dan a dichas prácticas, las diversas estrategias, modalidades y momentos en los que la realizan, así como diversos aspectos y circunstancias que facilitan u obstaculizan las posibilidades de desarrollarlas. Nuestros hallazgos se basan en el análisis cualitativo de 8 grupos focalizados con varones y mujeres de clase media de entre 20 y 50 años de edad, realizados en el Area Metropolitana de Buenos Aires en el año 2013. Si bien la salud emerge como una motivación para realizar ejercicios, generalmente no es considerada la principal, apareciendo diversos incentivos, como la sociabilidad y el placer asociados con las prácticas deportivas, la competición, la estética y hasta su utilidad compensatoria para con otros comportamientos considerados dañinos para el cuerp