1,721,060 research outputs found
Plateforme systèmes de culture : SIC
No full textLes données résultent de l’évaluation expérimentale de 4 systèmes de culture.
Les objectifs du Système Productif à Hautes Performances Environnementales (PHPE) sont de satisfaire un ensemble de critères environnementaux (réduction de la pollution par les pesticides et nitrate ; augmentation de la biodiversité implantée) quantifiés et d’atteindre, dans ce cadre, une production élevée. Pour les trois autres systèmes, au respect des objectifs environnementaux du système PHPE s’ajoute une contrainte environnementale forte supplémentaire. Dans le Système Sans pesticide (SsPest), il est interdit d’utiliser tout traitement phytosanitaire (produits chimiques de synthèse et produits autorisés en agriculture biologique). Dans le Système Energie moins (ENm), la consommation d’énergie fossile doit être réduite de moitié à l’échelle du système par rapport au système PHPE. Dans le Système Gaz à Effet de Serre moins (GESm), les émissions de gaz à effet de serre doivent être réduites de moitié par rapport au système PHPE. Pour ces trois derniers systèmes, les niveaux de production seront aussi élevés que possible compte tenu des contraintes et objectifs environnementaux assignés.
Cette évaluation sur le long terme (12 ans : 2009-2020), initiée en 2008, se déroule sur une parcelle de plus de six hectares, sur des sols limoneux, très homogènes et profonds (profondeur supérieure à 1,80m) de la ferme d’AgroParisTech à Grignon (78, France : N 48.84°, E 1.95°).
Le dispositif comporte trois répétitions pour chacun des quatre systèmes, et la surface élémentaire des parcelles est de 4100m². Compte tenu de la forte homogénéité du sol, la variabilité interannuelle du climat a été privilégiée. Chaque année, chaque système de culture est représenté par une culture différente de la succession dans chacun des blocs.
Dans ce dispositif, des mesures nombreuses visent en premier lieu à évaluer la capacité des systèmes de culture à satisfaire les contraintes, les objectifs environnementaux et les niveaux de production assignés. Des diagnostics agronomiques appropriés permettent également de comprendre les raisons de ces performances. Les évolutions à moyen/long terme des caractéristiques physiques (état structural des sols,…), chimiques (teneurs en éléments minéraux, en pesticides et en matières organiques des sols) et biologiques (communautés de vers de terre et d’arthropodes, microflore des sols, peuplement d’adventices,…) du champ cultivé sont caractérisées et analysées pour évaluer les conséquences des systèmes expérimentés sur l’évolution des milieux.
Les données disponibles sont complémentaires à celles publiées dans divers data papers et disponibles dans data.gouv.
Ici sont aussi retranscrits les règles de décision définies en début de période expérimentales pour conduire de façon technique les différents systèmes de culture
N2O fluxes and soil mineral nitrogen contents - Innovative cropping systems
No full textN2O fluxes and soil mineral nitrogen contents (NH4+ and NO3-) in cropping systems designed to meet both environmental and production goals: a French nitrogen field data se
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Designing innovative productive cropping systems with quantified and ambitious environmental goals
No full textInternational audienceAgriculture must face a number of very pressing environmental issues. We used the prototyping method to design three innovative cropping systems, each satisfying three ambitious goals simultaneously: (1) overcoming a major environmental constraint, which represents a major break regarding objectives to be reached in current cropping systems (differing between systems: a ban on all pesticides but with chemical nitrogen (N) fertilizer permitted; reducing fossil energy consumption by 50%; or decreasing greenhouse gas (GHG) emissions by 50%), (2) meeting a wide range of environmental criteria and (3) maximizing yields, given the major constraint and environmental targets. A fourth cropping system was designed, in which the environmental and yield targets were achieved with no major constraint (the productive high environmental performance cropping system (PHEP) system). The performances of these innovative cropping systems were compared to a conventional system in the Ile-de-France region. We used a three-step prototyping method: (1) new cropping systems were designed on the basis of scientific and expert knowledge, (2) these system prototypes were assessed with tools and a model (ex ante assessment) adjusted to the set of constraints and targets, with optimization by an iterative process until the criteria were satisfied and (3) evaluation in a long-term field experiment (ex post assessment), which is currently underway. We describe only the first two steps here, together with the results of the prototypes assessment with tools and a model. The pesticide, energy and GHG constraints were fulfilled. All these innovative systems satisfied environmental criteria in terms of nitrogen and phosphorus management, pesticide use, energy consumption and crop diversity. For the pesticide-free system, the soil organic matter indicator was lower than expected due to frequent plowing (every 2 years) and yields were 20–50% lower than for the PHEP system, depending on the crop considered. We focus our discussions on the design methodology and the availability of scientific knowledge and tools for projects of this type
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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