1,721,022 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
Statistical modeling of the prognostic value of a parameter and proposition of an integrative score construction : application in localized colon cancer
No full textL’étude du pronostic des patients, c’est-à-dire la capacité à prédire la survenue d’un événement, est une problématique centrale en Oncologie. Plusieurs recommandations existent sur la bonne pratique pour l’étude d’un paramètre et la création d’un score pronostique, notamment une méthodologie développée par D. Vernerey (NNT: 2016BESA3004). L’intérêt de l’étude du pronostic des patients dans le cancer du colon localisé est triple: i) aider à la prise de décision pour l’introduction d’une chimiothérapie adjuvante chez les patients atteints d’un cancer du colon de stade II ii) diminuer le sur-traitement par chimiothérapie après une chirurgie chez les patients ayant un cancer du colon de stade III et ainsi réduire les séquelles neurologiques liées à l’oxaliplatine, iii) aider à la stratification et au design des essais thérapeutiques.Les objectifs de cette thèse étaient de résumer les facteurs pronostiques connus dans les cancers du colon localisé, et notamment les cancers du colon de stade III, d’identifier et de s’approprier une méthodologie adaptée pour l’évaluation précise des paramètres potentiellement associés avec la survie, et d’appliquer cette méthodologie pour la création d’un outil pronostique visant à expliquer le plus précisément possible le pronostic des patients atteints d’un cancer du colon localisé.Dans un premier temps nous avons analysé de façon précise la valeur pronostique du dosage biologique d’un marqueur tumoral connu de longue date : l’antigène carcino-embryonnaire (ACE). En effet, celui-ci est utilisé de façon peu précise dans la littérature avec un seuil de positivité très débattu. Nous avons montré que les patients ayant une valeur de l’ACE en post-opératoire considérée comme normale selon les seuils usuels constituaient une population très hétérogène en terme de risque de rechute et de décès. Nous avons modélisé la relation entre l’ACE et les survies sans maladie et globale, puis validé un seuil inférieur à celui utilisé usuellement pour la détection optimale du risque de progression et de décès. Cette étude a été menée dans 2 cohortes différentes : une cohorte de patients ayant un cancer du colon de stade II (étude MOSAIC), et une cohorte de patients traités pour un cancer du colon de stade III (étude MOSAIC puis validation externe dans l’étude PETACC-8). Chez les patients atteints d’un cancer du colon de stade II à haut risque de rechute, le dosage de l’ACE permettait d’identifier les patients bénéficiant de l’ajout de l’oxaliplatine à une chimiothérapie adjuvante à base de fluoropyrimidines seules.Après avoir validé la méthodologie de Vernerey et al pour l’étude d’un paramètre pronostique, nous avons appliqué ses recommandations pour la création d’un score pronostique dans le cancer du colon de stade III. Dans cette optique plusieurs modèles ont été créés afin de déterminer l’apport des différents groupes de variables à notre disposition (clinique, anatomopathologiques, biologiques, et moléculaires) dans l’estimation du pronostic de ces patients. Nous avons montré que l’ajout de ces différents paramètres améliorait significativement l’estimation du pronostic des patients. Enfin, à partir d’un modèle regroupant toutes ces variables, nous avons, toujours en suivant une méthodologie rigoureuse, créé un score pronostique et un nomogramme permettant d’expliquer avec des bonnes performances la survie sans maladie (c-index 0,70) et la survie globale (c-index 0,73). Ces outils n’avaient pas de caractère prédictif pour prédire le bénéfice de l’ajout du cetuximab à une chimiothérapie par FOLFOX chez les patients atteints d’un cancer du colon de stade III et inclus dans l’étude PETACC-8. Cette étude nécessitera une validation externe dans le futur.En conclusion, une approche méthodologique rigoureuse permet de mieux évaluer et exploiter des facteurs pronostiques, même connus, et de créer des outils permettant de répondre à des questions cliniques pertinentesThe study of patients’ prognosis, that is to say the ability to predict the occurrence of an event, is a central problem in oncology. Several guidelines for the study of factor and the creation of a prognostic score exist, in particular the one by D. Vernerey et al (NNT 2016BESA3004). The aims of studying prognosis for patients with a localized colon cancer are: i) to help clinician decide whether adjuvant chemotherapy should be administered for stage II colon cancer, ii) to decrease over treatment for stage III colon cancer and thus decrease the oxaliplatin related neuropathy, iii) to better stratify and design the clinical trials.The aims of this PhD thesis were, firstly, to summarize the known prognostic factors for localized colon cancer (specifically for stage III colon cancer), secondly to identify and better understand an appropriate and rigorous methodology for the precise evaluation of a prognostic factor, and finally to apply this methodology in order to construct a prognostic tool for the prediction of recurrence or death in localized colon cancer.The first step of this work was to analyse precisely the prognostic value of a well known underestimated biological marker: the carcinoembryonic antigen (CEA). Indeed, the cut-point value for “normal” CEA is debated in the literature. We showed that patients with a value of post operative CEA considered as normal were in fact a very heterogeneous population in term of risk of recurrence and death. We modelled the relation between CEA level and disease free and overall survivals, then we validated a lower cut-point value for CEA which better predicted the risk of recurrence or death. This work was lead in two cohorts: one of stage II colon cancer (MOSAIC trial), and one of stage III colon cancer (MOSAIC trial and external validation in the PETACC-8 trial). In the patients with stage II colon cancer, we found a predictive value of the CEA level: only patients with high risk stage II colon cancer with a high post operative CEA level benefited from the oxaliplatin addition to the fluorouracile chemotherapy backbone.The second step of this work was to apply Vernerey’s methodology for the creation of a prognostic score in stage III colon cancer. In this study, we created four models in order to analyse the input of different kinds of variables in the prognosis assessment: clinical, pathological, biological, and molecular variables. We showed that the addition of pathological, biological and molecular variables increased significantly the performance of the prediction model. Then we created a score and a nomogram for each survival endpoint with a good discrimination (c-index=0.70 for disease free survival, and 0.73 for overall survival). However, no predictive value was found for these scores in term of chemotherapy benefit. This study will have to be validated externally.To conclude, a rigorous methodological approach leads to better evaluation and utilisation of prognostic factors, and helps create effective tools answering clinical questions
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
Statistical methodology for risk prediction and prongnostic score construction in oncology and kidney transplantation : a cornerstone of prcision medicine
No full textLe pronostic est depuis longtemps un concept de base de la médecine. Hippocrate envisageait déjà le pronostic des maladies par l’étude des circonstances passées, l’établissement des faits présents, et enfin la prédiction des phénomènes à venir. Pour lui, tout l’art du pronostic était de savoir interpréter intelligemment ces informations, et ainsi moduler le pronostic en fonction de leur valeur relative. Une recherche à visée pronostique consiste toujours actuellement en l’examen des relations entre un état de santé connu au moment de l’investigation et un évènement futur. L’augmentation de l’espérance de vie implique que de plus en plus de personnes vivent avec une ou plusieurs maladies ou problèmes altérant leur santé. Dans ce contexte, l’étude du pronostic n’a jamais été aussi importante. Cependant, contrairement au domaine des essais cliniques randomisés dans lequel les recommandations CONSORT sont appliquées depuis plus de 20 ans et garantissent une recherche de qualité, la recherche pronostique commence seulement à se doter d’initiatives similaires. En effet, des recommandations TRIPOD ont été élaborées en 2015 et un groupe de travail, PROGRESS, s’est constitué en 2013 au Royaume-Uni et a fait le constat que les recherches a visée pronostique sont réalisées de façon très hétérogènes et malheureusement ne respectent pas toujours des standards de qualité nécessaires pour supporter leurs conclusions et garantir la reproductibilité des résultats (...)Prognosis is historically a basic concept of medicine. Hippocrates already considered the prognosis of disease as the study of the past circumstances, the establishment of the present state of health and finally the prediction of future events. He presented the prognosis as the ability to interpret these elements and to adapt the prognosis regarding their relative values. Currently, the prognostic research is still based on the examination of the relationship between a well-established health condition at the time of the investigation and the occurrence of an event. The increase in life expectancy implies that more and more people are living with one or more diseases or with problems that can impair their health status. In this context, the study of the prognosis has never been more important. However, in comparison with the field of randomized clinical trials in which the CONSORT statement recommendations are implemented for more than 20 years in order to guarantee quality research, the prognostic research only begins to develop similar initiatives. Indeed, in 2015 the TRIPOD statement recommendations were provided and in 2013 a working group called PROGRESS was constituted in the United Kingdom and its members made the observation that prognostic researches are developed with considerable heterogeneity in the methodology used and unfortunately do not always meet the quality standards required to support their conclusions and their reproducibility (...
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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