660 research outputs found

    Damage detection and quantification using transmissibility

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    Structures experience various types of loads along their lifetime, which can be either static or dynamic and may be associated to phenomena of corrosion and chemical attack, among others. As a consequence, different types of structural damage can be produced; the deteriorated structure may have its capacity affected, leading to excessive vibration problems or even possible failure. It is very important to develop methods that are able to simultaneously detect the existence of damage and to quantify its extent. In this paper the authors propose a method to detect and quantify structural damage, using response transmissibilities measured along the structure. Some numerical simulations are presented and a comparison is made with results using frequency response functions. Experimental tests are also undertaken to validate the proposed technique. (C) 2011 Elsevier Ltd. All rights reserved

    Service Provisioning in Edge-Cloud Continuum Emerging Applications for Mobile Devices

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    Disruptive applications for mobile devices can be enhanced by Edge computing facilities. In this context, Edge Computing (EC) is a proposed architecture to meet the mobility requirements imposed by these applications in a wide range of domains, such as the Internet of Things, Immersive Media, and Connected and Autonomous Vehicles. EC architecture aims to introduce computing capabilities in the path between the user and the Cloud to execute tasks closer to where they are consumed, thus mitigating issues related to latency, context awareness, and mobility support. In this survey, we describe which are the leading technologies to support the deployment of EC infrastructure. Thereafter, we discuss the applications that can take advantage of EC and how they were proposed in the literature. Finally, after examining enabling technologies and related applications, we identify some open challenges to fully achieve the potential of EC, and also research opportunities on upcoming paradigms for service provisioning. This survey is a guide to comprehend the recent advances on the provisioning of mobile applications, as well as foresee the expected next stages of evolution for these applications

    The Genetic Background of Metabolic Trait Clusters in Children and Adolescents

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    Background: It is well known that metabolic risk factors of cardiovascular diseases are correlated, but the background of this clustering in children is more poorly known than in adults. Thus, we studied the contribution of genetic and environmental factors to the clustering of metabolic traits in childhood and adolescence. Data and Methods: Nine metabolic traits were measured in 214 complete twin pairs aged 3-18 years in the Autonomous Region of Madeira, Portugal, in 2007 and 2008. The variation of and covariations between the traits were decomposed into genetic and environmental components by using classical genetic twin modeling. Results: A model, including additive genetic and environmental factors unique for each twin individual, explained the variation of metabolic factors well. Under this model, the heritability estimates varied from 0.47 (systolic blood pressure in children under 12 years of age) to 0.91 (high-density lipoprotein [HDL] cholesterol in adolescents 12 years of age or older). The most systematic correlations were found between adiposity (body mass index and waist circumference) and blood lipids (HDL cholesterol, low-density lipoprotein cholesterol, and triglycerides), as well as blood pressure. These correlations were mainly explained by common genetic factors. Conclusions: Our results suggest that obesity, in particular, is behind the clustering of metabolic factors in children and adolescents. Both general and abdominal obesity partly share the same genetic background as blood lipids and blood pressure. Obesity prevention early in childhood is important in reducing the risk of metabolic diseases in adulthood.Peer reviewe

    Phylogeny, ultrastructure, histopathology and prevalence of Myxobolus oliveirai sp. nov., a parasite of Brycon hilarii (Characidae) in the Pantanal wetland, Brazil

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    This paper presents the morphological, histological and ultrastructural characteristics of Myxobolus oliveirai sp. nov., a parasite of the gill filaments in Brycon hilarii from the Brazilian Pantanal. Out of 216 B. hilariispecimens examined (126 wild and 90 cultivated), 38.1% of wild specimens (n = 48) were infected. The parasites form elongated plasmodia primarily in the tip of gill filaments, reaching about 3 mm in length. A thorough comparison with all the Myxobolus species described from South American hosts, as well as nearly all the Myxobolus species described so far is provided. Partial sequencing of the 18S rDNA gene revealed a total of 1,527 bp. The Myxobolus species parasite of B. hilarii did not match any of the Myxozoa available in GenBank. In the phylogenetic analysis, M. oliveirai sp. nov. composed a monophyletic group with eight other species: five species of Myxobolus parasites of mugilid fishes, two parasites of pangasiid and one of centrarchid. Infection prevalence values of the parasite revealed no significant differences between wet and dry seasons or between males and females. The importance of the infection to the farming of the host species is emphasized1056762769sem informaçã

    Particle production from nonlocal gravitational effective action

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    In this paper we show how the nonlocal effective action for gravity, obtained after integrating out the matter fields, can be used to compute particle production and spectra for different space-time metrics. Applying this technique to several examples, we find that the perturbative calculation of the effective action up to second order in curvatures yields exactly the same results for the total number of particles as the Bogolyubov transformations method, in the case of masless scalar fields propagating in a Robertson-Walker space-time. Using an adiabatic approximation we also obtain the corresponding spectra and compare the results with the traditional WKB approximation.Comment: 22 pages, LaTeX, no figures. Corrected version with new comments and results. To appear in Phys. Rev.

    (An)Isotropic models in scalar and scalar-tensor cosmologies

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    We study how the constants GG and Λ\Lambda may vary in different theoretical models (general relativity with a perfect fluid, scalar cosmological models (\textquotedblleft quintessence\textquotedblright) with and without interacting scalar and matter fields and a scalar-tensor model with a dynamical Λ\Lambda) in order to explain some observational results. We apply the program outlined in section II to study three different geometries which generalize the FRW ones, which are Bianchi \textrm{V}, \textrm{VII}0_{0} and \textrm{IX}, under the self-similarity hypothesis. We put special emphasis on calculating exact power-law solutions which allow us to compare the different models. In all the studied cases we arrive to the conclusion that the solutions are isotropic and noninflationary while the cosmological constant behaves as a positive decreasing time function (in agreement with the current observations) and the gravitational constant behaves as a growing time function

    Accurate Atmospheric Parameters at Moderate Resolution Using Spectral Indices: Preliminary Application to the MARVELS Survey

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    Studies of Galactic chemical and dynamical evolution in the solar neighborhood depend on the availability of precise atmospheric parameters (Teff, [Fe/H] and log g) for solar-type stars. Many large-scale spectroscopic surveys operate at low to moderate spectral resolution for efficiency in observing large samples, which makes the stellar characterization difficult due to the high degree of blending of spectral features. While most surveys use spectral synthesis, in this work we employ an alternative method based on spectral indices to determine the atmospheric parameters of a sample of nearby FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving power (R~12,000). We have developed three codes to automatically normalize the observed spectra, measure the equivalent widths of the indices and, through the comparison of those with values calculated with pre-determined calibrations, derive the atmospheric parameters of the stars. The calibrations were built using a sample of 309 stars with precise stellar parameters obtained from the analysis of high-resolution FEROS spectra. A validation test of the method was conducted with a sample of 30 MARVELS targets that also have reliable atmospheric parameters from high-resolution spectroscopic analysis. Our approach was able to recover the parameters within 80 K for Teff, 0.05 dex for [Fe/H] and 0.15 dex for log g, values that are lower or equal to the typical external uncertainties found between different high-resolution analyzes. An additional test was performed with a subsample of 138 stars from the ELODIE stellar library and the literature atmospheric parameters were recovered within 125 K for Teff, 0.10 dex for [Fe/H] and 0.29 dex for log g. These results show that the spectral indices are a competitive tool to characterize stars with the intermediate resolution spectra.Comment: Accepted for publication in AJ. Abstract edited to comply with arXiv standards regarding the number of character

    DETECCIÓN, CARACTERIZACIÓN SEROLÓGICA Y ANTIBIOGRAMAS DEEscherichia coli AISLADAS DE CARNE DE TERNERA (BABILLA) ENTERA Y PICADA

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    Los brotes de Enfermedades Transmisibles por Alimentos (ETA) representan una preocupación para las industrias alimentarias y los organismos de salud pública. Las cepas patógenas de Escherichia coli están comúnmente presentes en el trato intestinal de los animales, lo que favorece la contaminación durante el sacrificio o durante un procesamiento inadecuado de la canal. La importancia que la carne tiene en la alimentación humana junto con la necesidad de ofrecer un alimento inocuo e incapaz de transmitir enfermedades, incitaron el desarrollo de este estudio, que tiene por objetivos, detectar, caracterizar los serogrupos y realizar los antibiogramas de E. coli. aisladas de 30 muestras de carne de ternera (babilla) comercializadas en mercados y carnicerías de Río de Janeiro, Brasil. Se emplearon 15 muestras de carne entera y 15 de carne picada (en el propio establecimiento). Se utilizaron diferentes metodologías para la confirmación bioquímica y serológicamente de las colonias aisladas. Una vez identificados los serogrupos, se testó su susceptibilidad a diferentes antibióticos. De las muestras analizadas, el 100% resultaron contaminadas con coliformes totales y en cinco (16,7%) de ellas, no se detectaron coliformes fecales. En carne entera, los recuentos de coliformes totales oscilaron de 4,0x103 a 1,1x106 y E.coli de 0 a 2,4x103 mientras que en carne picada oscilaron de 4,4x103 a 2,5x107 y 0 a 3,0x105, respectivamente. Con relación a la metodología empleada,el segundo método demostró ser más eficiente que el tercer método, ya que presentó un mayornúmero de colonias confirmadas. Utilizando el segundo método, se aislaron 52 cepas de E. colienteropatogénica (EPEC), ocho cepas de E. coli enteroinvasiva (EIEC) y una cepa de E. coli enterohemorrágica (EHEC). Las cepas de E. coli aisladas y tipificadas como patógenas presentaron un gran espectro de resistencia a los antibióticos testados, principalmente a ampicilina (11,32%), cefalotina (11,11%) y amicacina (10,06%). La presencia de serogrupos de E. coli en las muestras confirman la necesidad de implantar los programas de Buenas Practicas de Fabricac ión (BPF), Procedimientos Patrón de Higiene Operacional (PPHO) y Análisis de Peligros y Puntos Críticos de Control (APPCC), lo que diminuiría el riesgo para el consumidor.Palabras clave: Escherichia coli, carne de ternera entera y picada, antibiograma.Escherichia coli, whole and ground beef, antibiogram

    Homemade oral supplement: a proposal for the nutritional recovery of children and adolescents with cancer

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    Objective The aim of this study was to evaluate the impact of homemade oral supplements on the nutritional recovery of patients with mild or severe malnutrition or at nutritional risk. Methods Eight recipes of homemade oral supplements containing 30% to 35% of the total energy expenditure were proposed. The patients with severe malnutrition (group B) received the oral supplement for 2 weeks and the others for 4 weeks (group A). Oral supplementation with homemade supplements was compared with oral supplementation with store-bought supplements, investigated earlier with a protocol with the same design. Results Homemade oral supplements contain much lower amounts of certain micronutrients but are five times cheaper than store-bought supplements. In group A, 88% of the patients taking homemade oral supplements and 84% of the patients taking store-bought supplements responded positively to supplementation. In group B, 22% of the patients taking homemade oral supplements and 25% of the patients taking store-bought supplements recovered. The difference was not significant. The impact of store-bought supplementation on the triceps skinfold thicknesses and arm circumferences of the patients in group A was greater than that obtained with homemade supplements. In group B, the effect on triceps skinfold thickness was not significant (p=0.16). Patients taking homemade or store-bought oral supplements presented similar protein and energy intakes and improvements in nutritional status. Only the body composition of patients in group A taking store-bought oral supplements was better. Conclusion The results obtained by this study suggest that the therapeutic use of homemade oral supplements is an alternative capable of promoting the nutritional recovery of cancer patients, especially those who cannot afford store-bought supplements.Objetivo Avaliar o impacto do suplemento oral artesanal na recuperação do estado nutricional de pacientes com desnutrição leve, grave e com risco nutricional. Métodos Propuseram-se oito receitas de suplementos visando ofertar entre 30,0% e 35,0% do gasto energético total. Os pacientes com desnutrição grave (grupo B) receberam o suplemento oral por duas semanas, e os demais pacientes (grupo A), por quatro semanas. Para a comparação dos resultados obtidos com o emprego do suplemento oral artesanal, foram utilizados dados referentes a um protocolo anterior, com o mesmo desenho, entretanto, com a utilização de suplemento oral industrializado. Resultados O suplemento oral artesanal fica muito aquém no que diz respeito a alguns micronutrientes, entretanto é cinco vezes mais barato do que a preparação com o suplemento oral industrializado. Os pacientes do grupo A com suplemento oral artesanal apresentaram 88,0% de resposta positiva na semana de avaliação, enquanto os com suplemento oral industrializado tiveram 84,0%. No grupo B, foram recuperados 22,0% dos pacientes com suplemento oral artesanal e 25,0% do grupo com suplemento oral industrializado, não apresentando, portanto, diferença significante. Comparando o impacto do industrializado com o do artesanal na prega cutânea tricipital e circunferência do braço, verificou-se que o suplemento oral industrializado no grupo A apresentou melhores resultados que o suplemento oral artesanal, e no grupo B, esse efeito observado na prega cutânea não foi significante (p=0,16). Os consumos de energia e de proteína, assim como a evolução nutricional, foram semelhantes entre suplemento oral industrializado e suplemento oral artesanal. Apenas a composição corpórea no grupo A com suplemento oral industrializado apresentou melhores resultados. Conclusão Os resultados apresentados neste estudo sugerem que o emprego da terapia com suplemento artesanal seja uma opção capaz de auxiliar na recuperação nutricional de pacientes oncológicos e uma opção para populações financeiramente desfavorecidas.Hospital Samaritano de São PauloInstituto Adriana GarófoloUniversidade Federal de São Paulo (UNIFESP) Departamento de Pediatria Instituto de Oncologia PediátricaUniversidade Federal de São Paulo (UNIFESP) Departamento de PediatriaUNIFESP, Depto. de Pediatria Instituto de Oncologia PediátricaUNIFESP, Depto. de PediatriaSciEL
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