1,720,981 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Role of eosinophils and innate lymphoid cells in asthma
No full textDans la première partie de cette thèse, nous avons cherché à déterminer le rôle de l’éosinophile circulant dans l’asthme par une approche transcriptomique. Nos résultats suggèrent que l’éosinophile recruté sur un site inflammatoire présente des fonctions immunomodulatrices, importantes dans la réparation tissulaire et le retour à l’homéostasie. Dans la deuxième partie de cette thèse, nous avons étudié le rôle des cellules NK et des cellules lymphoïdes innées de type 2 (ILC2) dans l’inflammation asthmatique. Les cellules NK circulantes sont fortement activées dans l’asthme sévère et ont la capacité d’induire l’apoptose d’éosinophiles autologues in vitro. La PGD2 induit la production d’IL-13 par les ILC2 en synergie avec les cytokines épithéliales IL-25 et IL-33. Enfin, ces fonctions sont régulées par la LXA4. En conclusion, notre travail de thèse met en lumière de nouveaux rôles pour l’éosinophile et les cellules lymphoïdes innées dans l’immunopathologie de l’asthme.In the first part of the thesis, we adopted a transcriptomic-based approach to investigate the activation state of circulating eosinophils in patients with asthma and other unrelated hypereosinophilic diseases. Taken together, our results, which suggest that esoinophils, recruited to inflammatory sites exhibit non-specific immunomodulatory functions important for tissue repair and homeostasis. In the second part of the thesis, we investigated the role of NK cells and type 2 innate lymphoid cells (ILC2) in asthma inflammation. Circulating NK cells are highly activated in severe asthma and promote apoptosis of autologous eosinophils in vitro. ILC2 generate interleukin-13 in response to prostaglandin D2 alone and in a synergistic manner with the airway epithelial cytokines IL-25 and IL-33. Finally, these functions are regulated by lipoxine A4. In conclusion, this thesis highlights new roles for eosinophils and innate lymphoid cells in asthma immunopathology
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Involvement of the interaction between fibrocytes and CD8+ T cells in Chronic Obstructive Pulmonary Disease (COPD)
No full textLa bronchopneumopathie chronique obstructive (BPCO) est un problème de santé majeur, qui touche plus de 251 millions de personnes dans le monde. Le principal facteur de risque est l'exposition à la fumée de cigarette. La BPCO est caractérisée par une inflammation chronique des voies respiratoires et par un remodelage bronchique entraînant une diminution non réversible des débits d'air. Les patients atteints de BPCO sont souvent victimes d'épisodes d'exacerbations, qui sont des phases d'aggravation des symptômes respiratoires. Les traitements pharmacologiques actuels de la BPCO améliorent les symptômes et réduisent la fréquence des exacerbations mais n'ont aucun effet sur le déclin de la fonction respiratoire et la mortalité. La péribronche des patients atteints de BPCO est le siège d'une infiltration importante de cellules immunitaires et d'un remodelage tissulaire, permettant des contacts persistants entre cellules résidentes et cellules immunitaires. L'objectif de cette thèse est d'étudier si des contacts entre les cellules immunitaires et les cellules résidentes pourraient être impliqués dans la pathophysiologie de la BPCO. Plus particulièrement, j'ai cherché à savoir si les fibrocytes tissulaires, qui sont cellules produites par la moelle osseuse avec des propriétés fibroblastiques, peuvent interagir avec les lymphocytes T CD8+ (LT CD8+). De plus, je voulais savoir si le contact entre ces deux types de cellules pouvait être impliqué dans l'activation immunitaire chronique observable dans la BPCO. En utilisant des co-immunomarquages de spécimens bronchiques obtenus par chirurgie chez 17 patients atteints de BPCO et 25 sujets témoins, et des méthodes spécifiques d'analyse d'images, nous avons quantifié la distribution relative des fibrocytes et des LT CD8+. Des analyses transcriptomiques et des expériences fonctionnelles ont été utilisées pour étudier la capacité des LT CD8+ tissulaires à attirer les fibrocytes. Des co-cultures autologues directes et indirectes de fibrocytes et de LT CD8+, isolés à partir d'échantillons de sang de patients atteints de BPCO, ont été réalisées pour tester l'effet des fibrocytes sur la prolifération des LT CD8+ et le profil de sécrétion des cytokines. Nous avons défini un modèle mathématique, avec des règles et les paramètres dérivés de mes mesures expérimentales. Je montre que les fibrocytes et les LT CD8+ se trouvent à proximité dans les voies respiratoires distales et que les interactions (indirectes et directes) sont plus fréquentes dans les tissus des patients atteints de BPCO par rapport à ceux des sujets témoins. L'augmentation des interactions entre les LT CD8+ et les fibrocytes est associée à une altération de la fonction pulmonaire. J'ai démontré que les LT CD8+ tissulaires de patients atteints de BPCO favorisent le chimiotactisme des fibrocytes via l'axe CXCL2/8-CXCR1/2. Dans un essai in vitro, les LT CD8+ individuels établissent des interactions de courte durée avec les fibrocytes. Les contacts directs entre les deux types de cellules déclenchent la prolifération des LT CD8+ de manière dépendante de CD54 et CD86, ainsi que la production de cytokines pro-inflammatoires. La modélisation mathématique permet non seulement de décrire avec précision la distribution cellulaire selon que le sujet est sain ou atteint de BPCO, mais aussi de suivre la dynamique cellulaire. Au total, ma thèse révèle que des interactions locales entre fibrocytes et LT CD8+ peuvent se produire in vivo et pourraient compromettre l'équilibre entre immunité protectrice et inflammation chronique dans les bronches des patients atteints de BPCO.Chronic obstructive pulmonary disease (COPD) is a major health problem, with more than 251 million people affected worldwilde. The major risk factor is cigarette smoke exposure. COPD is characterized by a chronic airway inflammation and by bronchial remodeling, leading to non-reversible airflow decrease. Patients with COPD often experience exacerbations wich are phases of worsening respiratory symptoms. Current pharmacological therapies for COPD improve symptoms and reduce exacerbations frequency but have no effect on the respiratory function decline and the mortality. Peri-bronchial area of COPD are the siege of extensive immune cell infiltration and tissue remodelling, allowing persistent contacts between resident and immune cells. The aim of this thesis is to study whether contacts between immune cells and resident cells could be involved in the pathophysiology of COPD. More particularly, I investigated whether tissue fibrocytes, which are fibroblast-like cells produced by the bone marrow, can interact with CD8+ T cells. In addition, I wanted to know if the contact between both cell types could be a cause of undue chronic immune activation. Using co-immunostaining of bronchial specimens obtained from surgery in 17 COPD patients and 25 control subjects, and specific image analysis methods, I quantified the relative distribution of fibrocytes and CD8+ T cells. Transcriptomic analyses and functional experiments were used to investigate tissular CD8+ T cells capacity to attract fibrocytes. Direct and indirect autologous co-cultures of fibrocytes and CD8+ T cells, isolated from blood samples of COPD patients, were performed to test fibrocyte effect on CD8+ T cell proliferation and cytokines secretion profile. We defined a computational model, with rules and parameters derived from my experimental measurements. I show that fibrocytes and CD8+ T cells are found in vicinity in distal airways and that interactions (both indirect and direct) are more frequent in tissues from COPD patients compared to those of control subjects. Increased interactions between CD8+ T cells and fibrocytes are associated with altered lung function. I demonstrated that tissular CD8+ T cells from COPD patients promote fibrocyte chemotaxis via the CXCL2/8-CXCR1/2 axis. In an in vitro assay, individual CD8+ T cells establish short-lived interactions with fibrocytes. Direct contacts between both cell types trigger CD8+ T cell proliferation in a CD54- and CD86-dependent manner, as well as pro-inflammatory cytokines production. Computer modelling allows not only to accurately describe cellular distribution depending on whether the subject is healthy or COPD but also to follow the dynamics. Altogether, my thesis reveals that local interactions between fibrocytes and CD8+ T cells can occur in vivo and could jeopardize the balance between protective immunity and chronic inflammation in bronchi of COPD patients
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
- …
