1,721,143 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
Phenotypic plasticity and environmental determinisms involved in carrot quality
No full textLa qualité nutritionnelle et organoleptique des fruits et légumes rencontre un intérêt grandissant. Considérée comme “légume santé”, la carotte s’illustre par l’accumulation au niveau racinaire d’une grande diversité de métabolites d’intérêt, incluant les sucres et caroténoïdes. L’importante variabilité phénotypique observée peut s’illustrer par un effet propre aux variétés, aux environnements ou encore par une plasticité plus ou moins prononcée des variétés vis-à-vis des teneurs en métabolites. L’objectif de cette thèse est de déterminer les facteurs pouvant expliquer les niveaux observés de plasticité phénotypique pour une large gamme de métabolites d’intérêt, afin de tendre vers une amélioration de la qualité chez la carotte. L’approche métabolomique met clairement en évidence une structuration de la diversité génétique ainsi que différents niveaux et profils de plasticité phénotypique en fonction des métabolites. L’approche par régression PLS entre les données agro-climatiques issues d’essai multi environnements et la variation de teneur en sucres et caroténoïdes sur ces mêmes environnements a permis l’identification et la hiérarchisation de facteurs agro-climatiques largement impliqués dans l’accumulation de ces composés respectifs. Parallèlement, il a pu être montré que certains stades de développement, notamment précoces, sont déterminants pour la teneur de ces composés mesurée à la récolte. Enfin, l’approche transcriptomique suggère l’implication de facteurs de transcription comme pouvant expliquer la différence de plasticité variétale à l’égard de la teneur en caroténoïdes. L’ensemble de ces travaux, intégrant plasticité phénotypique et élucidation des déterminismes environnementaux impliqués dans la variation de teneur en sucres et caroténoïdes, apportent de nouvelles connaissances sur l’élaboration et l’amélioration de la qualité chez la carotte, essentielles pour sa maîtrise, que ce soit dans un cadre de sélection variétale ou de production.There is an increasing interest for nutritional and sensorial quality of vegetables. Depicted as a healthy vegetable, carrot is characterized by the accumulation of a wide range of key metabolites in large amount at root level, including sugars and carotenoids. Substantial phenotypic variability observed may depend on variety effect, environmental effect ormore and less pronounced plasticity of varieties regarding metabolite accumulation. The aim of this present thesis is to elucidate the factors which can explain the observed phenotypic plasticity levels, for a wide range of key metabolites, in order to improve carrot quality. The metabolomic approach clearly shows a genetic diversity structuration and different levels and patterns of plasticity according to metabolites. PLSr regression approach between agroclimatic variables from multi-environments trials and sugars and carotenoids variation content in these environments has led to the identification and prioritization of agroclimatic factors widely involved in the accumulation of these respective compounds. In addition, it has been shown that some developmental stages, especially the early ones, are crucial for these compounds content at harvest. Finally, the transcriptomic approach suggests key roles of some transcription factors to explain the difference of varietal plasticity concerning carotenoid accumulation. All this work, integrating phenotypic plasticity and elucidation of environmental determinisms involved in carotenoids and sugars content, provides new knowledge for quality improvement and mastering in carrot, whether in a breeding or production perspective
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
Modification of carotenoid metabolism in response to biotic and abiotic stresses in carrot
No full textLa carotte présente un grand intérêt nutritionnel comme source alimentaire en caroténoïdes. Pourtant, la connaissance des mécanismes d’accumulation de ces composés est un enjeu majeur. Si le déterminisme génétique a été relativement bien étudié, l’impact de stress sur l’accumulation des caroténoïdes chez la carotte reste méconnu. Ce travail de thèse vise donc à déterminer (i) l’impact de stress biotique et abiotique appliqués individuellement ou en combinaison sur les teneurs en caroténoïdes dans les feuilles et racines de carotte,(ii) les mécanismes de régulation pouvant expliquer ces variations (iii) si le métabolisme secondaire est affecté spécifiquement, indépendamment du métabolisme primaire.Les résultats mettent en évidence un effet négatif des différentes conditions de stress, en particulier appliquées en combinaison, sur les teneurs en caroténoïdes dans les feuilles et les racines de carotte, mais dépendent du génotype. La régulation transcriptionnelle au niveau de la voie de biosynthèse des caroténoïdes ne peut expliquer qu’en partie les variations de teneurs. Les variations de teneurs en chlorophylles des feuilles et sucres des racines sont corrélées à celles des teneurs en caroténoïdes, suggérant des mécanismes communs de régulation.Ce travail montre que l’impact de stress en culture, et en particulier leur combinaison, est une composante importante de l’élaboration de la qualité nutritionnelle. Les travaux doivent être poursuivis afin d’établir un schéma plus précis de la régulation de l’accumulation des caroténoïdes chez la carotte.Carrot presents a high nutritional interest as a carotenoid intake source. However, knowledge about accumulation mechanisms of these compounds is a major issue. While genetic determinism was relatively well studied, the impact of stresses on carotenoid accumulation in carrot remains unknown. This thesis work aims to determine (i) the impact of biotic and abiotic stresses applied individually or in combination on carotenoid contents in carrot leaves and roots, (ii) the regulation mechanisms which could explainthese variations and (iii) if secondary metabolism is specifically affected independently from primarymetabolism. Results bring to light a negative effect of the different stress conditions, particularly applied in combination, on carotenoid contents in carrot leaves and roots but depend on genotypes. Transcriptional regulation based on carotenoid biosynthetic genes can only partially explain contentvariations. Chlorophyll content variations in leaves and sugar content variations in roots are correlated to those of carotenoids suggesting common regulation mechanisms. This work shows that the impact of stress on culture, and particularly in combination, is an important determinism of nutritional quality. Further works need to be performed to establish a more precise regulation network pattern of carotenoid accumulation in carrot
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
Abstract
No full textCarrot is considered a healthy vegetable as it is rich in fibre and antioxidant-related compounds and with a low level of kilocalories. Some compounds are involved in both the nutritional and sensory quality. In most cases, carrot quality is highly dependent on the variety. However, environment conditions and growing practices influence carrot composition significantly. Whether for breeding for product quality or for producing carrots with high and stable quality, such influence needs to be better understood and taken into account. This chapter discusses the determinants of carrot quality, focusing on the influence of growing environment (such as area and year of production, sowing date and crop cycle, temperature and soil nature), growing practices (e.g. soil preparation, application of nitrogen, water supply, cover crops and growth stimulators), and cropping systems (conventional and organic). The effects of various stresses, such as water, temperature, salinity, cold, hail and Alternaria dauci infection, on carrot root composition and sensory perception are also discussed
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
- …
