1,720,953 research outputs found
Design and analysis of trials for mosquito control interventions with contamination
Get PDFThe movement of mosquitoes leads to a contamination of the effect of an intervention targeting mosquito-borne diseases because people living nearby might benefit from a reduced density of infectious mosquitoes. It is usually attempted to avoid these diffuse effects when testing new interventions. In this thesis however, we seek to understand these contamination effects and build the theoretical basis to estimate them since they may provide valuable information about the intervention effectiveness and should be considered.
We use partial differential equations to describe the dynamics of an Aedes aegypti population under a modified male mosquito release on an island to inform the trial design of such an intervention. By invoking optimal control theory, we assess the optimized release strategy under the constraint of a limited availability of modified males to achieve elimination as fast as possible. Our findings show that, to eliminate Aedes aegypti from a single location, the optimal release strategy is to initially release a high number of modified males and to subsequently release fewer mosquitoes proportionally to the decreasing female population. The best approach for elimination on the whole island is to target high mosquito density areas first and then move the focus in both directions along the periphery of the island until all areas have been covered. Sufficient release intensity has to be retained in the already targeted areas throughout this process to prevent reintroduction.
We then shift our focus to the analysis of trials targeting Anopheles mosquitoes. Informed by a model that describes the dispersion of mosquito with Gaussian kernels, we propose a nonlinear random effects model based on a sigmoid function of the distance to the nearest discordant household to analyze cluster randomized trials or stepped wedge cluster randomized trials of malaria interventions. This model approach leads to a closed-form contamination range that quantifies the measurable extent of the contamination. In a simulation study, we find that this approach indeed provides unbiased and precise estimates of effectiveness if an appropriate number of households is not affected by the contamination range. We extend this model to provide an estimate of the intervention effectiveness as a function of the intervention coverage at each household, that we define based on the estimated contamination range.
This methodological development is then applied to three trials of malaria interventions: the Navrongo trial on the use of insecticide treated nets, the SolarMal trial on the impact of mass trapping of mosquitoes with odor-baited traps and the AvecNet trial on the effect of adding pyriproxyfen to long-lasting insecticidal nets. These three trials were conducted in different countries with different settlement patterns and were testing different malaria interventions. In our reanalyses we find that a sigmoid analysis yields a similar estimate of effectiveness compared to what was found in the original analysis. Furthermore, in all three trials the contamination range is around 100 to 200 meters,
which is much less than the maximal distance Anopheles mosquitoes can fly.
For contamination effects to be estimable, the trial must be designed to collect information from zones where contamination is likely. We use the gained insights to give guidance on how to plan trials to allow for contamination and develop algorithmic approaches for cluster construction that allow for cluster boundaries to pass villages and hence enable the estimation of the contamination range. We conclude by connecting the work on the optimized release strategy for modified male mosquitoes with the analysis of trials with contamination by proposing a trial design that accounts for the dispersal of modified males and tests both the short-term effectiveness and the potential for elimination.
The work reported here creates a solid foundation for measuring and understanding the effects of contamination in trials of mosquito-borne diseases. Cluster size can be reduced to the minimum determined by operational factors or contamination effects, without the need for clusters to correspond to separated villages. This reduces the required number of participants in trials of malaria interventions and should lead to more cost-efficient trials and a better understanding of the indirect effects of interventions in protecting nearby nonusers
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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