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A reproductive resilience index for pelagic fish in the southern Humboldt Current Large Marine Ecosystem
No full textEfforts to manage small and medium-sized pelagic fishes (SMPF) using traditional stock assessment methods are hampered by the elusive relationship between spawning stock biomass and recruitment. We propose to compute a reproductive resilience index (RRI) in three steps: (i) we selected 16 biological traits related to distinct aspects of SMPF reproductive biology and char-acterized by a continuous (e.g., growth rate) or ordinal variable (e.g., spawning site fidelity) scored from 1 to 5 (1 representing a low contribution of the trait to reproductive resilience); (ii) an expert panel assigned the traits’ scores to five exploited species in the southern Humboldt Current Large Marine Ecosystem; (iii) a Bayesian Belief Network (BBN) model was used to estimate an RRI based on the combination of the traits’ scores. The BBN was used to explore environmental effects on the species’ RRI, as some reproductive traits can show intraspecies variability under external forces (e.g., fishing pressure). Through proving the RRI application to detect variability in species’ resilience at local time series, we show how the resulting RRI can be interpreted by fishery managers to improve the current management of SMPF.Les efforts de gestion des petits et moyens poissons pélagiques (PMPP) par des méthodes traditionnelles d’évaluation des stocks sont limités par la mauvaise définition de la relation entre la biomasse du stock reproducteur et le recrutement. Nous proposons d’établir un indice de résilience reproductive (IRR) par les trois étapes suivantes : (i) nous avons choisi 16 caractères biologiques reliés à différents aspects de la biologie de reproduction des PMPP et caractérisés par une variable continue (p. ex., taux de croissance) ou ordinale (p. ex. fidélité au lieu de frai) notée de 1 à 5 (1 représentant une faible contribution du caractère à la résilience reproductive), (ii) un panel d’experts a assigné les notes pour ces caractères pour cinq espèces exploitées dans le grand écosystème marin du courant de Humboldt méridional, (iii) un modèle de réseau de croyances bayésien (RCB) a été utilisé pour estimer un IRR basé sur la combinaison des notes des caractères. Le RCB a été utilisé pour explorer les effets environnementaux sur l’IRR des espèces, certains caractères reproductifs pouvant présenter une variabilité intraspécifique sous l’effet de forçages externes (p. ex. la pression de pêche). En démontrant l’application de l’IRR pour détecter la variabilité de la résilience d’espèces pour des séries chronologiques locales, nous illustrons comment l’IRR résultant peut être interprété par les gestionnaires de pêches pour améliorer la gestion actuelle des PMPP
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Relationships between the behavioral dynamics of fish spawning aggregations and reproductive resilience
Get PDFIn the context of reproductive resilience, the dynamics of phenotypically plastic spawning behaviors are shaped by the environmental and anthropogenic stressors that a species is exposed to. Spawning locations, timing, and periodicity are three characteristics that are progressively being recognized as important aspects of productivity and resilience in fish species. The chapters of this dissertation examine those factors as they are filtered through the ecological contexts of the environment, life history traits and fisheries exploitation. The following research covers spatio-temporal scales from a species and site-specific study of spawning behavior to a multi-species, regional study of spawning behavior and the interactions with fisheries. Chapters two and three illustrate how reproductive resilience is realized in species that spawn frequently across spatially diverse locations. These reproductive traits have evolved to maintain reproductive success and population stability in response to the unpredictable and highly variable environments the species inhabit. Chapter four investigates the use of passive acoustic techniques to locate and monitor spawning in species that produce sound during the spawning process. That study seeks to resolve the spatial resolution of passive acoustic sampling and monitoring in shallow estuarine environments. Chapter five provides further support for including spawning behaviors in the study of productivity and resilience in fish populations by showing that species that aggregate to spawn, along with large changes in density, for short and predictable time periods, are the most vulnerable to targeted fishing and are more likely to have been historically overfished. This work builds on the concept and framework of reproductive resilience in fish and provides both theoretical support and empirical evidence for further consideration of the spatial and temporal components of spawning in stock assessments, climate variability assessments and the conservation of fish populationsMarine Scienc
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
A New Method Of Oocyte Separation And Preservation For Fish Reproduction Studies
No full textVirginia Institute of Marine Scienc
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
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