1,721,280 research outputs found
Adaptations des pathogènes, mutations, multirésistances... Quand l'évolution défie la santé : dossier
No full textLes campagnes de contrôle et d'éradication des maladies infectieuses représentent une avancée médicale majeure. Mais ce progrès est désormais freiné par l'évolution rapide des agents pathogènes. Pour les prendre de vitesse, il est aujourd'hui indispensable de comprendre les mécanismes de leur adaptation
Ecology and evolution of cancer
No full textCancer is definitely not a disease strictly confined to human populations. Indeed, despite a lack of robustly collected datasets, it is becoming increasingly evident that cancer can affect almost all multicellular species. In this chapter, we review how animal species may have selected complex and efficient mechanisms of cancer resistance, which could rely on cellular processes or behavior adjustment. Meanwhile, we illustrate also how cancer can interfere with the ecology of the affected species, leading to scrambled abiotic and biotic relationships with other species that could impact significantly the whole ecosystem functioning. We finally suggest that such cancer resistance mechanisms and ecosystem structure should interact together, which is extraordinarily challenging to forecast but could represent a crucial insight into our understanding of community ecology, as well as the complex selective pressures played by the carcinogenic process
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
Ecology and evolution of cancer
No full textWhile it is widely acknowledged that intratumor heterogeneity is mostly generated by genomic instability, we propose that genomic instability is only part of a proximate mechanism that maintains intratumor heterogeneity through oncogenic selection. Within tissues and organs, malignant cells achieve greater success by cooperating in the process of tumor construction, rather than by just being in isolation. This process would involve the selection of a bet-hedging strategy during oncogenesis to generate the diversity of cell components needed to build, de novo, such an intricate cooperative system. This process requires sufficient time to generate the diversity of relevant clones, which may explain why solid tumors tend to occur late in life. In liquid environments, opportunities for structurally complex tumors are more limited. This may help explain why cancer cells from liquid tumors generally do not aggregate, are on average less heterogeneous (i.e., low selection for bet-hedging), and can be detrimental early in life (e.g., leukemia). In an evolutionary context, this suggests that the bet-hedging strategy is not only a universal risk-diversification strategy that evolves in the populations which face uncertain future and/or environment, it is also selected when there is a need of building, de novo, cooperative and complex systems
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
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