Measuring Progress on the Control of Porcine Reproductive and Respiratory Syndrome (PRRS) at a Regional Level: The Minnesota N212 Regional Control Project (Rcp) as a Working Example.

Due to the highly transmissible nature of porcine reproductive and respiratory syndrome (PRRS), implementation of regional programs to control the disease may be critical. Because PRRS is not reported in the US, numerous voluntary regional control projects (RCPs) have been established. However, the effect of RCPs on PRRS control has not been assessed yet. This study aims to quantify the extent to which RCPs contribute to PRRS control by proposing a methodological framework to evaluate the progress of RCPs. Information collected between July 2012 and June 2015 from the Minnesota Voluntary Regional PRRS Elimination Project (RCP-N212) was used. Demography of premises (e.g. composition of farms with sows = SS and without sows = NSS) was assessed by a repeated analysis of variance. By using general linear mixed-effects models, active participation of farms enrolled in the RCP-N212, defined as the decision to share (or not to share) PRRS status, was evaluated and used as a predictor, along with other variables, to assess the PRRS trend over time. Additionally, spatial and temporal patterns of farmers' participation and the disease dynamics were investigated. The number of farms enrolled in RCP-N212 and its geographical coverage increased, but the proportion of SS and NSS did not vary significantly over time. A significant increasing (p<0.001) trend in farmers' decision to share PRRS status was observed, but with NSS producers less willing to report and a large variability between counties. The incidence of PRRS significantly (p<0.001) decreased, showing a negative correlation between degree of participation and occurrence of PRRS (p<0.001) and a positive correlation with farm density at the county level (p = 0.02). Despite a noted decrease in PRRS, significant spatio-temporal patterns of incidence of the disease over 3-weeks and 3-kms during the entire study period were identified. This study established a systematic approach to quantify the effect of RCPs on PRRS control. Despite an increase in number of farms enrolled in the RCP-N212, active participation is not ensured. By evaluating the effect of participation on the occurrence of PRRS, the value of sharing information among producers may be demonstrated, in turn justifying the existence of RCPs

Thermodynamics of Small Magnetic Particles

In the present paper, we discuss the interpretation of some of the results of the thermodynamics in the case of very small systems. Most of the usual statistical physics is done for systems with a huge number of elements in what is called the thermodynamic limit, but not all of the approximations done for those conditions can be extended to all properties in the case of objects with less than a thousand elements. The starting point is the Ising model in two dimensions (2D) where an analytic solution exits, which allows validating the numerical techniques used in the present article. From there on, we introduce several variations bearing in mind the small systems such as the nanoscopic or even subnanoscopic particles, which are nowadays produced for several applications. Magnetization is the main property investigated aimed for two singular possible devices. The size of the systems (number of magnetic sites) is decreased so as to appreciate the departure from the results valid in the thermodynamic limit; periodic boundary conditions are eliminated to approach the reality of small particles; 1D, 2D and 3D systems are examined to appreciate the differences established by dimensionality is this small world; upon diluting the lattices, the effect of coordination number (bonding) is also explored; since the 2D Ising model is equivalent to the clock model with q=2 degrees of freedom, we combine previous results with the supplementary degrees of freedom coming from the variation of q up to q=20. Most of the previous results are numeric; however, for the case of a very small system, we obtain the exact partition function to compare with the conclusions coming from our numerical results. Conclusions can be summarized in the following way: the laws of thermodynamics remain the same, but the interpretation of the results, averages and numerical treatments need special care for systems with less than about a thousand constituents, and this might need to be adapted for different properties or devices.Fil: Vogel, Eugenio. Universidad de La Frontera; Chile. Center for the Development of Nanoscience and Nanotechnology; ChileFil: Vargas, Patricio. Center for the Development of Nanoscience and Nanotechnology; Chile. Universidad Técnica Federico Santa María; ChileFil: Saravia, Gonzalo. Universidad de La Frontera; ChileFil: Valdes, Julio. Universidad de La Frontera; ChileFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Centres, Paulo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

AN ANALYSIS OF A UNITED STATES-CANADA-MEXICO FREE TRADE AGREEMENT

This is one of two papers commissioned by the International Agricultural Trade Research Consortium on various aspects related to the agricultural sector of a prospective North American Free Trade Agreement. The companion paper to this one has been prepared by a working group chaired by Richard Barichello, University of British Columbia. To minimize duplication with the Barichello paper this paper has given greater attention to the role of Mexico, currency exchange rates, and explicit modeling of the trade relationship.International Relations/Trade,

Propuesta de un manual de procedimientos basados en los principios HACCP, para la produccion de semillas de maiz sin presencia adventicia de trazas OGM indeseadas.

Resumen (Spanish, English)67 p.EI maíz en la actualidad es el tercer cultivo en importancia a nivel mundial por su volumen de producción. Las plantas transgénicas contienen uno o más genes que han sido insertados en forma artificial en lugar de que la planta los adquiera mediante la polinización. Esta tecnología proporciona un instrumento para identificar y aislar genes que controlan características especificas en una sola clase de organismos y para trasladar copias de esos genes a otro organismo muy diferente, que entonces tendrá también esas características. En la actualidad algunos mercados de destino de las semillas de maíz, principalmente Europa han establecido nuevas exigencias, en cuanto al nivel o porcentaje de contaminación transgenica, tanto en partidas de maíz convencional como también semillas modificadas genéricamente. Lo anterior se fundamenta, en el contexto de seguridad alimentaria, la necesidad de que cualquier siembra de maíz, convencional o transgénico, disponga de un sistema preventivo que garantice el control de los peligros inherentes a ]a contaminación transgénica. Chile ante este escenario no esta ajeno a estas prohibiciones, sin dejar de mencionar que en el año 1999 se sembraron al menos 30.000 hectáreas de transgenicos para la producción de semilla de exportación, principalmente maíz, mercado en el cual se ubica como el sexto exportador mundial de semillas. Este estudio tiene por objeto proponer un manual de procedimientos, que le permitan a las empresas chilenas multiplicadoras de semilla de maíz, disminuir los riesgos de contaminación adventicias de organismos genéticamente modificados indeseadas. Se planteó una encuesta a las principales empresas chilena multiplicadoras de maíz semillero libre de contaminación transgénica, basándose en el caso de producción de semilla de maíz libre de GMO de la empresa AGRICOLA GREEN SEED LTDA., durante la temporada 200212003. Dicha encuesta fué evaluada y analizada en un formato HACCP. Se estableció un manual de procedimientos, que permiten a las empresas chilenas multiplicadoras de semilla de maíz, disminuir los riesgos de contaminación adventicias de organismos genéticamente modificados indeseadas. Además, se pudo establecer que existen 11 puntos en las diferentes etapas del proceso productivos, que presentan algún grado de riesgo de contaminación GMO. Sin embargo, son solo 8 pasos, los considerados por las empresas como puntos críticos de control, los que, de ser manejados apegándose estrictamente a los procedimientos, permiten obtener semilla libre de contaminación adventicias de organismos genéticamente modificados

Evaluacion de la susceptibilidad de lineas parentales de maiz (Zea mays) a la roya comun (Puccinia sorghi)

46 p.Con el fin de evaluar la susceptibilidad de 229 líneas de maíz a la inoculación artificial con roya común (Puccinia sorghi), se llevó a cabo un ensayo de campo en el que se cuantificaron los índices de incidencia y severidad para los distintos genotipos. Éste se condujo bajo un diseño experimental completamente al azar (DCA). La severidad de los síntomas se analizó mediante una escala ordinal, y la incidencia fue medida como la relación entre el número de hojas infectadas por planta y el número total de hojas por planta. Durante el desarrollo del ensayo, los tratamientos presentaron síntomas claros del ataque del hongo en distintos grados. Los resultados obtenidos mostraron la existencia de diversas reacciones a la inoculación artificial con el hongo, por parte de las distintas líneas de maíz consideradas en el estudio. Basados en la reacción de los 229 genotipos evaluados, destacaron claramente los tratamientos correspondientes a las líneas 204 y 206, las que presentaron los menores valores tanto para incidencia como para severidad

Toward MR protocol-agnostic, unbiased brain age predicted from clinical-grade MRIs

The difference between the estimated brain age and the chronological age ('brain-PAD') could become a clinical biomarker. However, most brain age models were developed for research-grade high-resolution T1-weighted MRIs, limiting their applicability to clinical-grade MRIs from various protocols. We adopted a dual-transfer learning strategy to develop a model agnostic to modality, resolution, or slice orientation. We retrained a convolutional neural network (CNN) using 6281 clinical MRIs from 1559 patients, among 7 modalities and 8 scanner models. The CNN was trained to estimate brain age from synthetic research-grade magnetization-prepared rapid gradient-echo MRIs (MPRAGEs) generated by a 'super-resolution' method. The model failed with T2-weighted Gradient-Echo MRIs. The mean absolute error (MAE) was 5.86-8.59 years across the other modalities, still higher than for research-grade MRIs, but comparable between actual and synthetic MPRAGEs for some modalities. We modeled the "regression bias" in brain age, for its correction is crucial for providing unbiased summary statistics of brain age or for personalized brain age-based biomarkers. The bias model was generalizable as its correction eliminated any correlation between brain-PAD and chronological age in new samples. Brain-PAD was reliable across modalities. We demonstrate the feasibility of brain age predictions from arbitrary clinical-grade MRIs, thereby contributing to personalized medicine

Modeling the input-output behaviour of wastewater treatment plants using soft computing techniques

Wastewater Treatment Plants (WWTPs) control and prediction under a wide range of operating conditions is an important goal in order to avoid breaking of environmental balance, keep the system in stable operating conditions and suitable decision-making. In this respect, the availability of models characterizing WWTP behaviour as a dynamic system, is a necessary first step. However, due to the high complexity of the WWTP processes and the heterogeneity, incompleteness and imprecision of WWTP data, finding suitable models poses substantial problems. In this paper, an approach via soft computing techniques is sought, in particular, by experimenting with fuzzy heterogeneous time-delay neural networks to characterize the time variation of outgoing variables. Experimental results show that these networks are able to characterize WWTP behaviour in a statistically satisfactory sense and also that they perform better than other well-established neural network mode.Peer ReviewedPostprint (published version

Sleep quality and disturbances in patients with dystrophic epidermolysis bullosa

Abstract Background Sleep disturbances in patients with dystrophic epidermolysis bullosa (DEB) have never been investigated and still remain an open question. We sought to examine sleep quality and its relationship with pain and mood disorders in DEB patients. Methods Twenty-eight DEB patients and 26 healthy individuals completed the following battery of scales: the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Medical Outcomes Study (MOS) Sleep Scale, the Visual Analogue Scale (VAS), the Hamilton Rating Scale for Anxiety (HAM-A) and Depression (HAM-D). Linear correlations and hierarchical regression analyses were performed. Results Patients with DEB have significantly lower scores in daytime sleepiness (p = 0.003) and higher level of pain (p = 0.009) in comparison to controls. The analysis of all PSQI and MOS items failed to demonstrate any statistically significant differences between DEB patients and controls, except for a sub component of PSQI measuring sleep disturbances (p = 0.003). In the study group, a positive correlation was found between PSQI and depressive symptoms (r = 0.56; p = 0.002), anxiety symptoms (r = 0.46; p = 0.015), and pain (r = 0.44; p = 0.020). These results were consistent with the hierarchical regression analysis showing a significant contribution of depression (ΔR2 = 21.8; p = 0.008), anxiety (ΔR2 = 14.5; p = 0.027), and pain (ΔR2 = 13.5; p = 0.032) to poor quality of sleep. Conclusions DEB patients showed a greater degree of sleep disturbances that can be influenced by depressive symptoms, anxiety symptoms, and pain compared with controls. Therefore, they should be screened for sleep issues that can be possibly impacted by pain and mood disorders

Dynamiques de compaction d'un milieu granulaire fragile

Lors de la compression d'un matériau poreux fragile, différents modes de compaction peuvent apparaître, en particulier une densification du milieu en bandes stationnaires ou en mouvement. Ce type de bandes oscillant dans le matériaux poreux ont été mises en évidence récemment lors de la compaction de céréales soufflées ou de neige. Nous présentons ici de nouveaux motifs de compaction observés expérimentalement dans un milieu composé de grains de riz soufflé, qui sont ensuite étudiés par un modèle numérique de ressorts sur réseau pouvant se briser. Selon les paramètres physiques de l'expérience, le milieu peut ainsi présenter une compaction erratique, où le matériau se densifie en différents endroit aléatoirement ; une ou plusieurs bandes de compaction se propageant dans le milieu ; ou encore une compaction diffuse. Les domaines d'existences de ces différents régimes dépendent de deux nombres sans dimensions caractérisant le système. Cette étude offre une meilleur compréhension des phénomènes microscopiques à l'oeuvre dans les matériaux poreux fragiles, voire dans d'autres matériaux comme les alliages métalliques qui peuvent présenter des phénomènes comparables (phénomène de Portevin-Le Châtelier)