1,721,004 research outputs found
Direct and transgenerational toxicity of glyphosate alone or associated to co-formulants on the health status of the rainbow trout (Oncorhynchus mykiss) : reproduction, immunity and antioxydant defenses
No full textLe glyphosate, substance active herbicide (SA) la plus utilisée dans le monde, est omniprésent dans les eaux de surface. L’évaluation de son écotoxicité et de celle des herbicides commerciaux à base de glyphosate (GBHs) est complexe et controversée. Le glyphosate et ses co-formulants peuvent être toxiques pour les poissons et leurs interactions ainsi que la transmission verticale de cette toxicité sont relativement peu étudiées. La toxicité directe et générationnelle d’une dose environnementale de glyphosate a été évaluée sur plusieurs générations de truites arc-en-ciel exposées chroniquement à la SA et à deux GBHs. L’état de santé des poissons a été déterminé via la mesure de paramètres biométriques, comportementaux et reproducteurs. L’immunité a été appréhendée lors d’infections virales expérimentales. Le métabolisme énergétique et le système antioxydant ont été suivis avec des marqueurs biochimiques. L’exposition directe aux contaminants n’a pas impacté la physiologie et la reproduction de la génération F0. Des perturbations du développement embryo-larvaire des descendances F1 et F2 ont été induites par les expositions directes, inter et transgénérationnelles ; avec un effet suggéré de la réexposition aux composés parentaux. Les modifications observées chez les stades précoces n’ont pas été détectées chez les truites juvéniles, bien que leur susceptibilité virale ait été affectée. La comparaison des effets du glyphosate et des GBHs semble montrer un rôle des co-formulants dans la modulation de la toxicité de la SA. Cependant, d’autres études sont nécessaires pour approfondir la compréhension liée aux mécanismes complexes de transmission de la toxicité du glyphosate.Glyphosate is the most used herbicidal active substance (AS) worldwide and is ubiquitous in surface waters. Evaluation of the ecotoxicity of this AS and its commercial formulations called "Glyphosatebased herbicides" (GBHs) is complex and controversial.Glyphosate and its co-formulants could be toxic for fish and little is known about their interactions.The vertical transmission of this toxicity among generations is also poorly studied. We investigated the direct and generational toxicity of environmentally relevant concentrations of glyphosate on several generations of rainbow trout chronically exposed to the AS or two GBHs. Fish health status was evaluated by measuring biometric, compartmental and reproductive parameters. Immunity was considered during experimental viral infections. Energetic metabolism and antioxidant system were followed up using different biochemical markers. Direct exposure of F0 generation to contaminants did not impact fish physiology or reproduction. F1 and F2 offsprings showed a disturbed embryo-larval development associated to direct, inter and transgenerational exposures; with a suggested effect of a re-exposure to parental compounds.Even if most of the changes observed on early stages were not detected on juvenile trout, their viral susceptibility was significantly affected. Comparisons between glyphosate and GHBs seem to demonstrate a role of the co-formulants in the modulation of the toxicity of the AS. However, further studies will be required to better understand the complex mechanism of glyphosate toxicity transmission and its modulation by co-formulants
Seawater carbonate chemistry and survival rate of F2 Dicentrarchus labrax after viral challenge
No full textBackground: Progressive CO2-induced ocean acidification (OA) impacts marine life in ways that are difficult to predict but are likely to become exacerbated over generations. Although marine fishes can balance acid–base homeostasis efficiently, indirect ionic regulation that alter neurosensory systems can result in behavioural abnormalities. In marine invertebrates, OA can also affect immune system function, but whether this is the case in marine fishes is not fully understood. Farmed fish are highly susceptible to disease outbreak, yet strategies for overcoming such threats in the wake of OA are wanting. Here, we exposed two generations of the European sea bass (Dicentrarchus labrax) to end-of-century predicted pH levels (IPCC RCP8.5), with parents (F1) being exposed for four years and their offspring (F2) for 18 months. Our design included a transcriptomic analysis of the olfactory rosette (collected from the F2) and a viral challenge (exposing F2 to betanodavirus) where we assessed survival rates.
Results: We discovered transcriptomic trade-offs in both sensory and immune systems after long-term transgenerational exposure to OA. Specifically, RNA-Seq analysis of the olfactory rosette, the peripheral olfactory organ, from 18-months-old F2 revealed extensive regulation in genes involved in ion transport and neuronal signalling, including GABAergic signalling. We also detected OA-induced up-regulation of genes associated with odour transduction, synaptic plasticity, neuron excitability and wiring and down-regulation of genes involved in energy metabolism. Furthermore, OA-exposure induced up-regulation of genes involved in innate antiviral immunity (pathogen recognition receptors and interferon-stimulated genes) in combination with down-regulation of the protein biosynthetic machinery. Consistently, OA-exposed F2 challenged with betanodavirus, which causes damage to the nervous system of marine fish, had acquired improved resistance.
Conclusion: F2 exposed to long-term transgenerational OA acclimation showed superior viral resistance, though as their metabolic and odour transduction programs were altered, odour-mediated behaviours might be consequently impacted. Although it is difficult to unveil how long-term OA impacts propagated between generations, our results reveal that, across generations, trade-offs in plastic responses is a core feature of the olfactory epithelium transcriptome in OA-exposed F2 offspring, and will have important consequences for how cultured and wild fish interacts with its environment
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
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
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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