1,721,018 research outputs found
Database and R script relative to "Spatial patterns of causality in temperate silvopastoral systems: a perspectives on nitrification stability in response to flooding" by Mettauer et al. (accepted)
No full textThis database and this script are linked to the article “Spatial patterns of causality in temperate silvopastoral systems: a perspective on nitrification stability in response to flooding” by Mettauer et al. (accepted). It is composed of one csv file with the database where dot is used as decimal and one pdf presenting the R script used to analyze the data
Spéciation et biodisponibilité du phosphore dans la rhizosphère
No full textISI Document Delivery No.: BJJ25 Times Cited: 0 Cited Reference Count: 16 Hinsinger, Philippe Jaillard, Benoit Le Cadre, Edith Plassard, Claude Proceedings Paper Conferemce on Stocks and Flows of Phosphorus in Terrestrail and Aquatic Ecosystems and Environmental Impacts Dec 07, 2006 Paris, FRANCE 195 rue saint-jacques, 75005 paris, franceNational audiencePhosphorus (P) is a major nutrient showing low mobility in soils due to the large reactivity of orthophosphate ions. The bioavailability of P here defined as the flux of P liable to be absorbed by a plant, is controlled by root absorption and by the chemical availability of P in the soil, which depends on its speciation. Actually, it also depends on other physicochemical and biochemical processes taking place in the rhizosphere that modify the availability of P in this particular soil volume. In most soils, the absorption of P by the roots results in i. a reduction in the concentration of P in solution (depletion) in the rhizosphere and, consequently, the setting up of a diffusion gradient for orthophosphate ions, and ii. a shift of the physicochemical equilibria of adsorption-desorption or precipitation-dissolution. However, the rhizosphere is not systematically depleted in P, suggesting the occurrence of other processes, such as exudation by roots or associated micro-organisms of compounds modifying soil P speciation, while modification of pH in the rhizosphere will result from protons/hydroxyls and/or organic acids produced by root exudation or microbial activity. Indeed, pH plays a major role in soil P speciation as well as in the equilibria of precipitation-dissolution of phosphatic minerals and adsorption-desorption of P. Organic acids act furthermore through ligand exchange, and possibly also via complexation/chelation of Ca, Fe and Al cations interacting with orthophosphate. Lastly, the production of enzymes able to hydrolyze organic P species (phosphatases) could have a major impact on P bioavailability in the rhizosphere. So far, we have little information on the relative importance of these processes in controlling P bioavailability.Le phosphore (P) est un élément nutritif majeur très peu mobile dans les sols, en raison de la forte réactivité des ions orthophosphates. La biodisponibilité de P, définie ici comme le flux de P susceptible d'être absorbé par une plante, est gouvernée par l'absorption racinaire et par la disponibilité chimique de P dans le sol, qui dépend de sa spéciation. En fait, elle repose aussi sur d'autres processus physico-chimiques et biochimiques qui ont lieu dans la rhizosphère, et qui résultent en une modification de la disponibilité de P dans ce volume singulier du sol. L'absorption de P par la racine résulte dans la plupart des sols i. en une diminution de la concentration en P en solution (appauvrissement) dans la rhizosphère et, par suite, en un gradient de diffusion des ions orthophosphates, et ii. en un déplacement des équilibres physico-chimiques d'adsorption-désorption ou précipitation-dissolution. Cependant, la rhizosphère n'est pas systématiquement appauvrie en P, ce qui suggère l'intervention d'autres processus tels que l'excrétion par les racines ou micro-organismes associés de composés modifiant la spéciation de P dans le sol : e.g. modifications de pH de la rhizosphère résultant de l'excrétion de protons/hydroxyles et/ou d'acides organiques. Or le pH joue un rôle majeur dans la spéciation de P dans le sol et les équilibres de précipitation-dissolution de minéraux phosphatés ou d'adsorption-désorption de P. Les acides organiques agissent en outre par échange de ligands, voire par complexation/chélation des cations Ca, Fe et Al en interaction avec les ions orthophosphates. Enfin, la production d'enzymes susceptibles d'hydrolyser les formes de P organique (phosphatases) peut jouer un rôle important dans la biodisponibilité de P dans la rhizosphère. La part relative de ces processus dans le déterminisme de la biodisponibilité de P demeure une inconnue à ce jour
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Critical review of anionic exchange resin membranes for in situ measurement of ion availability and fluxes
No full textNational audienc
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
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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