4,997 research outputs found

    Development of a species-specific coproantigen ELISA for human taenia solium taeniasis

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    Taenia solium causes human neurocysticercosis and is endemic in underdeveloped countries where backyard pig keeping is common. Microscopic fecal diagnostic methods for human T. solium taeniasis are not very sensitive, and Taenia saginata and Taenia solium eggs are indistinguishable under the light microscope. Coproantigen (CoAg) ELISA methods are very sensitive, but currently only genus (Taenia) specific. This paper describes the development of a highly species-specific coproantigen ELISA test to detect T. solium intestinal taeniasis. Sensitivity was maintained using a capture antibody of rabbit IgG against T. solium adult whole worm somatic extract, whereas species specificity was achieved by utilization of an enzyme-conjugated rabbit IgG against T. solium adult excretory-secretory (ES) antigen. A known panel of positive and negative human fecal samples was tested with this hybrid sandwich ELISA. The ELISA test gave 100% specificity and 96.4% sensitivity for T. solium tapeworm carriers (N = 28), with a J index of 0.96. This simple ELISA incorporating anti-adult somatic and anti-adult ES antibodies provides the first potentially species-specific coproantigen test for human T. solium taeniasis

    Vortex dynamics in a compact Kardar-Parisi-Zhang system

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    We study the dynamics of vortices in a two-dimensional, non-equilibrium system, described by the compact Kardar-Parisi-Zhang equation, after a sudden quench across the critical region. Our exact numerical solution of the phase-ordering kinetics shows that the unique interplay between non-equilibrium and the variable degree of spatial anisotropy leads to different critical regimes. We provide an analytical expression for the vortex evolution, based on scaling arguments, which is in agreement with the numerical results, and confirms the form of the interaction potential between vortices in this system.Comment: 5 pages, 3 figures and Supplementary Materia

    Optimal map of the modular structure of complex networks

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    Modular structure is pervasive in many complex networks of interactions observed in natural, social and technological sciences. Its study sheds light on the relation between the structure and function of complex systems. Generally speaking, modules are islands of highly connected nodes separated by a relatively small number of links. Every module can have contributions of links from any node in the network. The challenge is to disentangle these contributions to understand how the modular structure is built. The main problem is that the analysis of a certain partition into modules involves, in principle, as many data as number of modules times number of nodes. To confront this challenge, here we first define the contribution matrix, the mathematical object containing all the information about the partition of interest, and after, we use a Truncated Singular Value Decomposition to extract the best representation of this matrix in a plane. The analysis of this projection allow us to scrutinize the skeleton of the modular structure, revealing the structure of individual modules and their interrelations.Comment: 21 pages, 10 figure

    Analysis and forecast of performance characteristics of combine harvesters

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    ArticleThis article presents results of an experimental research of qualitative indicators of the modern combine harvesters (Case IH Axil Flow 8230, MasseyFergusonMFT7, JohnDeereS680i, ClaasLexion760, NewHolland CR9.80) used for winter wheat harvesting. Based on the results obtained, determination was made regarding the productivity of combine harvesters on the field, fuel consumption, and field conditions influence the grain loss and grain damage caused by a harvester. When conducting the experimental research of a combine's performance on the field a study of the effectiveness of the combine JohnDeereS680i was made on different modes. A program 'Machine Unit', designed by the authors, was used for the determination of productivity, fuel consumption and quality indicator for harvesting

    Primer registro de infestación de Epicrates cenchria cenchria (Squamata: Boidae) por Porocephalus (Pentastomida: Porocephalidae) en Ecuador

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    Endoparasites of the genus Porocephalus, which mainly affect lungs of snakes, are distributed in Asia, Africa and America. In Ecuador, these parasites have been reported only for Boa constrictor. Here, we report the first record of infestation of Porocephalus in Epicrates cenchria cenchria from the Ecuadorian Amazon, based on examination of museum specimens. We found 26 parasitic individuals in 4 infected snakes, with a maximum of 16 individuals in a juvenile snake, and a minimum of 2 in an adult snake. Morphometric characters of the Ecuadorian populations of Porocephalus do not agree with those described for the genus. Therefore, we recommend a thorough analysis to define the taxonomic identity of these parasites.Los endoparásitos del género Porocephalus, que infectan principalmente los pulmones de serpientes, se encuentran distribuidos en Asia, África y América. En Ecuador este parásito ha sido reportado únicamente en Boa constrictor. En el presente estudio reportamos los primeros registros de infestación de Porocephalus en Epicrates cenchria cenchria para la Amazonía ecuatoriana, basados en la revisión de especímenes de museo. Encontramos 26 individuos parásitos en 4 serpientes infectadas, con un máximo de 16 individuos en una serpiente joven y un mínimo de 2 en una serpiente adulta. La variabilidad morfométrica de las poblaciones ecuatorianas no encaja con las especies descritas de Porocephalus, por lo que recomendamos un análisis profundo para definir la identidad de estos parásitos

    Searching for the Kardar-Parisi-Zhang phase in microcavity polaritons

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    Recent analytical work has shown that, at certain values of the external pump, the optical parametric oscillator (OPO) regime of microcavity polaritons may provide a realisation of Kardar-Parisi-Zhang (KPZ) physics in 2D. Here, we verify this by solving the full microscopic model numerically using the truncated Wigner method, and studying the first order spatial correlations. For the predicted pump strengths, these correlations decay much faster and, perpendicular to the pump, fit closely to the stretched exponential form predicted by the KPZ equation, in contrast to the usual algebraic decay. This strongly indicates the viability of observing KPZ behaviour in future polariton OPO experiments.Comment: Main text (6 pages, 5 figures) plus supplementary material (3 pages, 5 figures
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