Sensitivity analysis of a hierarchical qualitative model – the analysis of MASC

AbstractSensitivity Analysis (SA) is applied to a hierarchical qualitative model built to assess the sustainability of cropping systems. Three approaches were tested to perform a first-order SA on such a model, assuming a fixed model structure and no correlation among input variables: (i) factorial designs combined with analysis of variance (ANOVA), (ii) conditional probabilities, (iii) Monte Carlo sampling (MC). If the complete factorial design is too large to be computed, MC and conditional probabilities represent efficient alternatives to perform an analysis of the overall qualitative model. Conditional probabilities exploit the hierarchical structure of the model to give exact first-order indices, while MC could be a more flexible approach for the introduction of correlations among variables. We discuss how such SA results can guide modellers and end-users in modelling and application phases

Near surface nutrient and phytoplankton distribution in the Drake Passage during early December

Nutrient concentrations and phytoplankton species composition in near surface samples were studied along a S-N gradient in the Drake Passage, in early December 1984. Nitrate concentrations were much lower than usually previously reported from circum-Antarctic waters. Comparison of dissolved nutrient concentrations with growth requirements of Antarctic plankton algae suggests potential limitation of at least some species by nitrate or silicate. The taxonomic composition of the phytoplankton in our samples seemed to be partially controlled by competition for limiting nutrients

Bourdieusian Reflections on Language: Unavoidable Conditions of the Real Speech Situation

The main purpose of this paper is to shed light on Pierre Bourdieu’s conception of language. Although he has dedicated a significant part of his work to the study of language and even though his analysis of language has been extensively discussed in the literature, almost no attention has been paid to the factthat Bourdieu’s account of language is based on a number of ontological presuppositions, that is, on a set of universal assumptions about the very nature of language. This article aims to fill this gap in the literature by offering a detailed overview of 10 key features which, from a Bourdieusian point of view, can be regarded as inherent in language. On the basis of this enquiry,the study seeks todemonstrate that——contraryto commonbelief——there is not only a Bourdieusian sociology of language but also a Bourdieusian philosophy of language, which provides a useful theoretical framework for examining the unavoidable conditions of the real speech situation. The paper draws to a close by reflecting on the flaws and limitations of Bourdieu’s approach to language

A pan-European epidemiological study reveals honey bee colony survival depends on beekeeper education and disease control

Reports of honey bee population decline has spurred many national efforts to understand the extent of the problem and to identify causative or associated factors. However, our collective understanding of the factors has been hampered by a lack of joined up trans-national effort. Moreover, the impacts of beekeeper knowledge and beekeeping management practices have often been overlooked, despite honey bees being a managed pollinator. Here, we established a standardised active monitoring network for 5 798 apiaries over two consecutive years to quantify honey bee colony mortality across 17 European countries. Our data demonstrate that overwinter losses ranged between 2% and 32%, and that high summer losses were likely to follow high winter losses. Multivariate Poisson regression models revealed that hobbyist beekeepers with small apiaries and little experience in beekeeping had double the winter mortality rate when compared to professional beekeepers. Furthermore, honey bees kept by professional beekeepers never showed signs of disease, unlike apiaries from hobbyist beekeepers that had symptoms of bacterial infection and heavy Varroa infestation. Our data highlight beekeeper background and apicultural practices as major drivers of honey bee colony losses. The benefits of conducting trans-national monitoring schemes and improving beekeeper training are discussed