1,721,273 research outputs found
Pollen genotyping by SABER–MassARRAY reveals that fewer than half of honey bee visits can cross-pollinate a self-incompatible crop
No full textPollen limitation occurs when insufficient pollen or the wrong pollen genotype reaches the stigma. The pollination efficiency of flower visitors to crops has been investigated, but the genotypes of crop pollen carried have rarely been identified. We developed a method that detects SNPs in the pollen carried by single bees, using a customized single allele base extension reaction (SABER) with MassARRAY to distinguish genotypes that contribute only a small fraction to a mixed-genotype pollen sample. We used this method to identify the cultivars of pollen carried by honeybees at increasing distances from a cross-pollen source in two multi-cultivar macadamia orchards, one with wide single-cultivar blocks and one with narrow single-cultivar blocks. We found that many honeybees carried exclusively self-pollen. Only 30-53% of honeybees carried cross-pollen, representing the maximum that potentially contributes to crop production in self-incompatible crops. Distance from a cross-pollen source or the orchard design did not significantly affect the percentage of honeybees carrying cross-pollen. This study demonstrates significant potential to increase the effectiveness of honeybees as pollinators. Orchards can be re-designed to interplant cross-pollen sources and maximize the number of honeybees contributing to crop production. Improving pollination effectiveness will help to alleviate the growing shortfall in the supply of beehives required for crop pollination.Full Tex
La Serre Françoise de, Leruez Jacques, Wallace Helen (dir.), Les politiques étrangères de la France et de la Grande-Bretagne depuis 1945
No full textRatte Philippe. La Serre Françoise de, Leruez Jacques, Wallace Helen (dir.), Les politiques étrangères de la France et de la Grande-Bretagne depuis 1945 . In: Vingtième Siècle, revue d'histoire, n°30, avril-juin 1991. pp. 127-128
Europe: regional laboratory for a global polity?
Full text linkConsiderable debate exists, in both academic and policy circles, about the utility of the European Union (EU) as a model for regional integration schemes elsewhere. While discussions of this sort remain interesting and important, they frequently run into the problem of the EU’s specificity, which in turn hinders our capacity to make generalisations based upon the experience of European integration. In this paper, we think slightly differently about the relationship between the EU and the global political economy through the exploration of two distinct, but related, sets of questions. The first bundle of issues surrounds the EU’s ‘balance of trade’ in various policy methodologies. Following Helen Wallace, we examine the ways in which the deployment of various styles of governance (including the classical ‘Monnet method’) have impacts upon or relate to the practices of economic governance elsewhere. The second set of questions emerge from the issue of ‘actorness’ in a global polity and the place that entities such as the EU might play in such a world order. In particular, we examine the politics of recognition in the global polity and a series of questions relating to the prerequisites for action in a globalised world
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
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
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