Epidemiologia y patogenia de la sarcocistosis ovina

La tesis consta de una primera parte epidemiologica, en la que se estudia la incidencia de parasitacion por Sarcocystis sobre 300 muestras de ovino tanto de sueros como de organos (lengua, corazon, esofago y diafragma), y una segunda parte en la que se hacen moculaciones experimentales en un rebaño de 18 ovejas adultas gestantes, con el fin de estudiar la patologia producida en estos animales por especies productoras de miaoquistes, a nivel hematico, seriologico y en cuanto al desarrollo de la gestacio

An assessment of phytoplankton primary productivity in the Arctic Ocean from satellite ocean color/in situ chlorophyll-a based models

We investigated 32 net primary productivity (NPP) models by assessing skills to reproduce integrated NPP in the Arctic Ocean. The models were provided with two sources each of surface chlorophyll-a concentration (chlorophyll), photosynthetically available radiation (PAR), sea surface temperature (SST), and mixed-layer depth (MLD). The models were most sensitive to uncertainties in surface chlorophyll, generally performing better with in situ chlorophyll than with satellite-derived values. They were much less sensitive to uncertainties in PAR, SST, and MLD, possibly due to relatively narrow ranges of input data and/or relatively little difference between input data sources. Regardless of type or complexity, most of the models were not able to fully reproduce the variability of in situ NPP, whereas some of them exhibited almost no bias (i.e., reproduced the mean of in situ NPP). The models performed relatively well in low-productivity seasons as well as in sea ice-covered/deep-water regions. Depth-resolved models correlated more with in situ NPP than other model types, but had a greater tendency to overestimate mean NPP whereas absorption-based models exhibited the lowest bias associated with weaker correlation. The models performed better when a subsurface chlorophyll-a maximum (SCM) was absent. As a group, the models overestimated mean NPP, however this was partly offset by some models underestimating NPP when a SCM was present. Our study suggests that NPP models need to be carefully tuned for the Arctic Ocean because most of the models performing relatively well were those that used Arctic-relevant parameters.Upon publication, the model input data provided to the participants will be available for academic purposes through the NASA SeaWiFS Bio-optical Archive and Storage System (http://seabass.gsfc.nasa.gov/), including integrated NPP, surface chlorophyll, SST, PAR, MLD, Rrs, aph, a443, bbp443, Zeu_lee, and sea ice concentration.This is the publisher’s final pdf. The article is copyrighted by the authors and published by John Wiley & Sons, Inc on behalf of American Geophysical Union. It can be found at: http://agupubs.onlinelibrary.wiley.com/agu/jgr/journal/10.1002/%28ISSN%292169-9291/Keywords: net primary productivity, ocean color model, model skill assessment, subsurface chlorophyll-a maximum, remote sensing, Arctic Ocea