1,885 research outputs found

    Comparaison de deux méthodes de mesure de l’efficacité et de la vitesse d’action des défanants sur la pomme de terre

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    On a comparé les résultats des mesures visuelles et métriques pour l'évaluation de l'efficacité et de la vitesse d'action des défanants de la pomme de terre (Solarium tuberosum) dans trois études conduites en champs à La Pocatière (Québec). Les résultats des deux mesures ont concordé dans 82,5% des cas pour la question d'évaluer si un effet était statistiquement significatif ou pas au seuil de 5%. La relation entre les deux mesures a été du type linéaire. Pour estimer la vitesse d'action du défanage, un polynôme a été ajusté à la réponse du défanage en fonction du temps et une analyse multivariée a été effectuée sur les coefficients des composantes polynomiales obtenues. Les résultats des deux types de mesures ont concordé dans 100% des cas. Il n'est donc pas nécessaire d'utiliser des mesures métriques pour exprimer l'efficacité et la vitesse d'action d'un défanant; les mesures visuelles sont tout aussi efficaces.Visual measurements were compared to metric measures to assess the performance and the rate of potato (Solarium tuberosum) vines desiccation in three field trials conducted at La Pocatiere, Quebec. The results of the two measures were in agreement in 82.5% of the cases for the question of testing if an effect was statistically significant or not at the 5% level. There was a linear relationship between the two methods of measurement. To estimate desiccation rate, a polynomial function was fitted to desiccation response over time and a multivariate analysis of variance was performed on the coefficients obtained. The results of the two types of measurements were in agreement in 100% of the cases. Thus, it is not necessary to use metric measurements to assess the performance and speed of potato vine desiccants; visual assessments can do the job as well

    Un modèle de projection des prix utilisant les relations intersectorielles de l’économie canadienne

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    This paper describes a simple cost-push price model which has been developed at the Structural Analysis Division of Statistics Canada.This price model is a traditional input/output cost-push model which has been adapted to utilize the rectangular industry by commodity input/output tables for Canada. It can be considered as the "dual" of the output model. Instead of analysing the propagation of demand through the economic system, the price model serves to analyse the propagation of factor prices throughout the system.The purpose of such a price formation model is to determine the impact on industry selling prices and domestic commodity prices arising from a change in impart commodity prices and primary input prices.This price model is of a static type; it accepts no substitutions and its structure is quite rigid. It is considered as being an annual model although it can be used for a different time period.This model is fully operational and is widely used by many government and private agencies

    Ultraestructura de la red alveolar y su relación con el recubrimiento de las paredes vasculares en olmos infectados con Ophiostoma novo-ulmi y en otras plantas infectadas con enfermedades similares de marchitamiento

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    In elms infected with Dutch elm disease, alveolar networks, demarcated by filamentous-like bands and confluent with similar matter (the coating) accumulating on vessel walls, occurred regularly in vessel elements. Similar material lined vessel walls in inoculated, sterilized, thin elm wood sections fixed by high pressure freezing. The coating was observed to connect with fungal cells and occasionally contained small opaque particles, the size of ribosomes, membranous and vesicular structures, and, following incubation of wood chips taken from diseased samples incubated on an agar medium, it still displayed similar matter. Coating and alveolar bands increased in thickness by confluence of other bands or membranous structures. Similar matter and structures also occurred in other plants affected by similar fungal wilt diseases. In all systems, the compact coating did not label for chitin, cellulose and pectin. In staghorn sumac, the probe for DNA attached to the coating. Altogether, in the light of these data, it appears that the coating and alveolar networks are not inert components, a fact which indicates their primordial probable pathogen origin. It is proposed that these elements might be important not only in the initial infection stages but also in older or recurrent infections at a time when host resistance mechanisms are ineffective.En olmos afectados por la grafiosis, la red alveolar, demarcada por bandas filamentosas, y confluente con acumulaciones de la misma sustancia (cubrición) presentes en las paredes de los vasos, aparece regularmente en los elementos conductores. Sustancias similares tapizan las paredes de los vasos en secciones de madera delgada de olmo inoculada y esterilizada, y posteriormente criofijadas a altas presiones. Se observó que la cubrición se conecta con las células del micelio y que ocasionalmente contenía pequeñas partículas opacas del tamaño de los ribosomas, estructuras membranosas y vesiculares, así como que, tras la incubación de astillas leñosas cogidas de muestras enfermas incubadas en agar, aún se presentaba una sustancia similar. La cubrición y las bandas alveolares aumentaron su espesor en la confluencia con otras bandas o estructuras membranosas. Estructuras y sustancias similares aparecieron también en otras plantas afectadas por enfermedades similares originadas por hongos que producen marchitamiento. En todos los sistemas, la cubrición compacta no pudo ser marcada como quitina, celulosa ni pectina. En zumaque (Rhus typhina), la sonda de ADN se pegó a la cubrición. En resumen, a la vista de estos datos, parece ser que la cubrición y la red alveolar no están formados por componentes inertes, un hecho que indica su probable origen patogénico. Se sugiere que esos elementos podrían ser importantes no sólo en las fases iniciales de la infección, sino también, en infecciones más desarrolladas o recurrentes, en el momento en que los mecanismos de resistencia del hospedante no son efectivos

    Discrete Cylindrical Vector Beam Generation from an Array of Optical Fibers

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    A novel method is presented for the beam shaping of far field intensity distributions of coherently combined fiber arrays. The fibers are arranged uniformly on the perimeter of a circle, and the linearly polarized beams of equal shape are superimposed such that the far field pattern represents an effective radially polarized vector beam, or discrete cylindrical vector (DCV) beam. The DCV beam is produced by three or more beams that each individually have a varying polarization vector. The beams are appropriately distributed in the near field such that the far field intensity distribution has a central null. This result is in contrast to the situation of parallel linearly polarized beams, where the intensity peaks on axis

    Peacebuilding lessons - learned project, phase II

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    Predicting the distribution of canine leishmaniasis in western Europe based on environmental variables.

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    The domestic dog is the reservoir host of Leishmania infantum, the causative agent of zoonotic visceral leishmaniasis endemic in Mediterranean Europe. Targeted control requires predictive risk maps of canine leishmaniasis (CanL), which are now explored. We databased 2187 published and unpublished surveys of CanL in southern Europe. A total of 947 western surveys met inclusion criteria for analysis, including serological identification of infection (504, 369 dogs tested 1971-2006). Seroprevalence was 23 2% overall (median 10%). Logistic regression models within a GIS framework identified the main environmental predictors of CanL seroprevalence in Portugal, Spain, France and Italy, or in France alone. A 10-fold cross-validation approach determined model capacity to predict point-values of seroprevalence and the correct seroprevalence class (20%). Both the four-country and France-only models performed reasonably well for predicting correctly the 20% seroprevalence classes (AUC >0 70). However, the France-only model performed much better for France than the four-country model. The four-country model adequately predicted regions of CanL emergence in northern Italy (<5% seroprevalence). Both models poorly predicted intermediate point seroprevalences (5-20%) within regional foci, because surveys were biased towards known rural foci and Mediterranean bioclimates. Our recommendations for standardizing surveys would permit higher-resolution risk mapping

    First Astronomical Use of Multiplexed Transition Edge Bolometers

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    We present performance results based on the first astronomical use of multiplexed superconducting bolometers. The Fabry-Perot Interferometer Bolometer Research Experiment (FIBRE) is a broadband submillimeter spectrometer that achieved first light in June 2001 at the Caltech Submillimeter Observatory (CSO). FIBRE'S detectors are superconducting transition edge sensor (TES) bolometers read out by a SQUID multiplexer. The Fabry-Perot uses a low resolution grating to order sort the incoming light. A linear bolometer array consisting of 16 elements detects this dispersed light, capturing 5 orders simultaneously from one position on the sky. With tuning of the Fabry-Perot over one free spectral range, a spectrum covering Δλ/λ= 1/7 at a resolution of δλ/λ ≈ 1/1200 can be acquired. This spectral resolution is sufficient to resolve Doppler-broadened line emission from external galaxies. FIBRE operates in the 350 µm and 450 µm bands. These bands cover line emission from the important star formation tracers neutral carbon [Cl] and carbon monoxide (CO). We have verified that the multiplexed bolometers are photon noise limited even with the low power present in moderate resolution spectrometry
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