1,721,041 research outputs found
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
Identification and functional analysis of plant targets of effectors of the root-knot nematode Meloidogyne incognita
No full textLes nématodes à galles (RKN) du genre Meloidogyne se distinguent par leur capacité à infecter plus de 5 500 espèces végétales, y compris les principales cultures, constituant ainsi une menace sérieuse pour l'agriculture mondiale. L'augmentation des populations de RKN due au changement climatique et la limitation des méthodes de lutte souligne l'urgence de progresser dans le développement de nouvelles stratégies de résistance efficaces. Les RKN orchestrent une reprogrammation moléculaire complexe des cellules végétales, entraînant la formation d'un site nourricier permanent composé de cellules géantes multinucléées et hypertrophiées, fournissant tous les nutriments nécessaires au nématode. Les effecteurs produits dans les glandes œsophagiennes des RKN et sécrétées in planta par un stylet ressemblant à une seringue, jouent un rôle déterminant dans le détournement des processus cellulaires de l'hôte et permettent le développement et le maintien des cellules géantes. Ces effecteurs ciblent différents compartiments subcellulaires, y compris le noyau, afin de manipuler les activités cellulaires de la plante. Comprendre les fonctions moléculaires des effecteurs de nématodes et les mécanismes qu'ils ciblent dans l'hôte végétal pour l'infection présente un intérêt à la fois fondamental et appliqué.Grâce à une combinaison d'approches de génomique comparative et de transcriptomique, plusieurs effecteurs candidats de Meloidogyne incognita ont été identifiés. L'hybridation in situ a confirmé que ces effecteurs sont exprimés dans les glandes salivaires des juvéniles, ce qui soutient leur potentiel de sécrétion directe dans les tissus végétaux. L'agroinfiltration d'effecteurs fusionnés à la GFP dans Nicotiana benthamiana a permis d'identifier des effecteurs spécifiques ciblant le noyau et le nucléole des cellules végétales, suggérant une manipulation des processus nucléaires et nucléolaires de la plante. En étudiant le rôle de ces effecteurs nucléaires à l'aide d'un test rapporteur de l'épissage basé sur la luminescence, nous avons pu identifier MiEFF186 comme un modulateur de l'épissage alternatif. La recherche des cibles végétales dans les racines de tomate de MiEFF186, à l'aide d'un crible double hybride chez la levure, a permis d'identifier deux protéines, CIS2/GDP1 et RRS1. Ces protéines sont connues pour être impliquées dans la modulation de l'épissage alternatif et/ou dans la biogenèse des ribosomes. Les essais de colocalisation ont montré que MiEFF186 interagit avec CIS2/GDP1 et RRS1 dans le nucléole des cellules végétales, suggérant que les RKN détournent les fonctions nucléolaires pour créer des conditions favorables à la formation du site nourricier. L'analyse fonctionnelle de CIS2/GDP1, utilisant la co-immunoprécipitation et des phénotypages de plantes VIGS et mutantes, a confirmé le rôle crucial de l'interaction CIS2/GDP1-MiEFF186 dans la réussite de l'infection par les nématodes. Les résultats obtenus pour RRS1 ont montré la régulation potentielle par MiEFF186 de la biogenèse des ribosomes dans le nucléole.Ce travail apporte des informations importantes sur les stratégies moléculaires utilisées par les RKN pour exploiter la machinerie cellulaire des plantes, en particulier les fonctions nucléolaires, afin d'établir et de maintenir les sites nourriciers. En identifiant des cibles végétales clés des effecteurs de nématodes, cette recherche ouvre de nouvelles perspectives pour le développement de stratégies de protection des cultures visant à perturber ces interactions moléculaires afin d'améliorer la résistance aux nématodes à galles.Among plant parasitic nematodes, root-knot nematodes (RKNs) of the genus Meloidogyne have a remarkable ability to infect more than 5,500 plant species, including major crops, posing a serious threat to global agriculture. The increase in RKN populations due to climate change and the limitation of control methods underlines the need for rapid progress in the development of new effective resistance strategies. RKNs orchestrate a complex molecular reprogramming of plant root cells leading to the formation of a permanent feeding structure made of multinucleated and hypertrophied giant cells that provide nutrients to the nematode. Effector proteins produced in oesophageal glands of the RKNs and secreted in planta through a syringe-like stylet, are instrumental in hijacking host cellular processes and enabling giant cell development and maintenance. These effectors target different subcellular compartments, including the nucleus, to modulate key cellular activities. Understanding the molecular functions of nematode effectors and the mechanisms they target in the host plant, is of interest on a fundamental point of view, and also for applied purposes.Using a combination of comparative genomics and transcriptomics, several candidate effectors of Meloidogyne incognita were identified. In situ hybridization confirmed that these effectors are expressed in juvenile salivary glands, supporting their potential for direct secretion into plant tissues. Agroinfiltration of GFP-tagged effectors in Nicotiana benthamiana identified specific effectors targeting the plant cell nucleus and nucleolus, suggesting manipulation of plant nuclear and nucleolar processes. By studying the role of these nuclear effectors using a luminescence-based splicing reporter assay, we were able to identify MiEFF186 as a modulator of alternative splicing. The search for the plant targets of MiEFF186 in tomato roots, using a yeast two-hybrid assay, identified two proteins, CIS2/GDP1 and RRS1. These proteins have been shown to be involved in the modulation of alternative splicing and/or in ribosome biogenesis. Co-localization assays showed that MiEFF186 interacts with CIS2/GDP1 and RRS1 in the plant nucleolus, suggesting that RKNs hijack nucleolar functions to create favorable conditions for the formation of the feeding site. Functional analysis of CIS2/GDP1 using co-immunoprecipitation, VIGS and mutant plants confirmed the critical role of the CIS2/GDP1-MiEFF186 interaction in successful RKN infection. The results obtained for RRS1 showed the potential regulation by MiEFF186 of ribosome biogenesis in the nucleolus.This work provides important insights into the molecular strategies used by RKNs to exploit plant cell machinery, particularly nucleolar functions, to establish and maintain feeding sites. By identifying critical plant targets of nematode effectors, this research opens up new avenues for the development of crop protection strategies aimed at disrupting these molecular interactions to improve resistance to RKNs
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No full textLes nématodes à galles du genre Meloidogyne sont des parasites obligatoires des plantes. Lors de l’interaction compatible, ils induisent la formation de cellules nourricières hypertrophiées et plurinucléées leur permettant d’assurer croissance et reproduction. L'étude des mécanismes moléculaires impliqués dans la formation de ces cellules géantes a permis d’identifier une protéine associée aux microtubules, MAP65-3, essentielle à la formation de ces cellules géantes et au développement du nématode. Un des partenaires protéiques de MAP65-3 est un homologue de BUB3, membre du « Mitotic Checkpoint Complex » (MCC). Le MCC est un point de contrôle de la mitose assurant la fidélité de la ségrégation des chromosomes. Au cours de ma thèse, j'ai caractérisé chez la plante modèle Arabidopsis thaliana les homologues du MCC: BUB3.1, MAD2 et la famille multigénique composée de BUBR1, BRK1 et BUB1.2. J’ai démontré les interactions in planta entre les membres du complexe, certaines interactions ayant lieu au niveau des noyaux, voire au niveau des centromères. J’ai réalisé l’analyse fonctionnelle de ces gènes et montré qu’ils étaient exprimés dans les tissus enrichis en cellules en division comme MAP65-3. L’étude de la localisation subcellulaire des protéines a révélé une localisation cytoplasmique pour BUB3.1, BUB1.2 et MAD2, nucléaire pour BUBR1 et centromérique pour BRK1. Nous avons pu également montrer que lorsque des défauts d’attachement des microtubules du fuseau mitotique sont provoqués, BUB3.1, BUBR1 et MAD2 se relocalisent au niveau des kinétochores. L’étude de la famille BUB1/BUBR1 a révélé que l’inactivation des gènes correspondants induisait une sensibilité accrue à un traitement chimique déstabilisant les réseaux de microtubules. L’étude de la mitose chez ces mutants a révélé que BUBR1 est essentielle à la réalisation d’une mitose sans erreur chez Arabidopsis. Ce travail a ainsi permis de caractériser pour la première fois le MCC chez A. thaliana.Root-knot nematodes from the genus Meloidogyne are obligate biotrophic plant parasites. During a compatible interaction, they induce the redifferentiation of root cells into multinucleated and hypertrophied feeding cells to ensure their growth and reproduction. The study of molecular and cellular mechanisms underlying giant cell ontogenesis has led to the identification of a Microtubule-Associated Protein, MAP65-3, essential for giant cell ontogenesis and nematode development. One of the MAP65-3 interacting partners is a BUB3 homologue, member of the Mitotic Checkpoint Complex (MCC). The MCC is a surveillance mechanism ensuring that chromosomes undergoing mitosis do not segregate until they are properly attached to the microtubules of the mitotic spindle. During my thesis, I have characterized the Arabidopsis thaliana orthologs of the MCC, BUB3.1, MAD2 and the multigenic family composed of BUBR1, BRK1 et BUB1.2. I have demonstrated that MAP65-3 and all the MCC members interact together in planta, some interactions taking place within the nuclei or at the centromeres. As MAP65-3, all these genes are expressed in dividing cells. The study of the subcellular localization of the protein showed a cytoplasmic localization for BUB3.1, BUB1.2 and MAD2, nuclear for BUBR1 and centromeric for BRK1. Thus, the MCC proteins did not relocalize to the kinetochore during a normal mitosis in planta. BUB3.1, BUBR1 and MAD2 localize to the unattached kinetochores following defects in spindle assembly as observed in cells treated with microtubule poisons. The functional analysis of BUB1/BUBR1 multigenic family showed that the knock-out mutants were more sensitive to microtubule-destabilizing drugs. Furthermore, analysis of mitosis revealed that BUBR1 is essential for an error-free mitosis in Arabidopsis. This work represents the first characterization of the MCC in A. thaliana
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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