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Harnessing molecular tools for the control of zoonotic soil-transmitted helminths
No full text© 2024 Patsy Alejandra Zendejas HerediaSoil-transmitted helminths (STHs) are a group of parasitic worms infecting over 1.5 billion people worldwide. These parasites cause some of the most significant Neglected Tropical Diseases and include the hookworms, whipworms, roundworms, and threadworms. STHs cause substantial morbidity in infected people that lead to severe health and socioeconomic consequences, particularly among children and women of reproductive age. Generally, these infections begin in childhood, and without proper control, infections persist into adulthood and promote intergenerational poverty. In 2020, the World Health Organization (WHO) introduced a new target aimed at eliminating the morbidity associated with STHs by 2030. However, the limited data available on zoonotic parasites, along with scant information on the applicability of molecular tools for their diagnosis, may potentially hamper the success of intervention strategies.
This thesis consists of a literature review, six chapters describing original research and a general discussion. The literature review provides an account of the role of STHs as significant causes of morbidity in humans and animals globally, and of the possible factors that drive the persistence of these parasites in endemic regions, despite years of control efforts. In addition, inaccurate diagnostic tools and mass deworming restricted to at-risk populations may contribute to making the WHO 2030 aims unachievable. Moreover, animals, particularly dogs, have been identified as potential reservoirs of zoonotic STHs, thus posing an additional threat to global control efforts. To this end, the objective of the present thesis was to conduct a robust comparison between microscopic and molecular tools to assess their diagnostic performance, providing evidence on the utility of real time qPCR in STH control surveys. Molecular tools were employed to gain insights into the epidemiology of zoonotic intestinal helminths in dogs across Cambodia and to describe the occurrence of the zoonotic hookworm Ancylostoma ceylanicum in unexpected regions of the Asia-Pacific and the Americas. Finally, I applied molecular tools to detect and genetically characterise STHs circulating in community dogs and in school-age children subjected to bi-annual mass drug administration. An integrated coprocopic and molecular approach was applied to assess the prevalence and distribution of zoonotic parasites infecting dogs in Cambodia (Chapter 2). The findings highlighted the need to transition from conventional microscopy techniques to more sensitive molecular tools to accurately identify zoonotic parasites in dogs. Notably, the high prevalence of zoonotic hookworms and Strongyloides stercoralis highlighted the need for inclusion of animals of all ages in control strategies.
Building on the results of Chapter 2, molecular tools were used to extend the investigation in selected areas of the Pacific and the Americas lacking molecular data on zoonotic STHs. The nation of Kiribati is one of the world’s poorest nations where STHs and diarrhoea remains leading infectious diseases. Despite the KIRIBATI–WHO Cooperation Strategy 2018–2022, no information was available on the presence and diversity of zoonotic STHs in free-roaming animals. The results (Chapter 3) demonstrated that dogs play a major role in contaminating the environment with zoonotic STHs, potentially serving as reservoirs for infections to humans. Given the effectiveness of molecular tools in detecting zoonotic parasites in dogs, I sought to apply qPCR in other regions lacking molecular data. The Americas were identified as a key area of interest due to historical A. ceylanicum presence, insufficient molecular data, and confirmed infections in travellers returning from Latin America. This study revealed a notable prevalence of zoonotic STHs in free-roaming dogs in Grenada, West Indies, in the Caribbean and the first molecular evidence confirming A. ceylanicum occurrence in dogs in the continent. Additionally, we utilised qPCR and DNA sequencing to screen coyote scats in Costa Rica, identifying A. ceylanicum in wildlife in the Americas for the first time.
In Chapter 5, a thorough comparison between conventional microscopy techniques and qPCR was conducted. Diagnostic performance, including egg recovery rates and limits of detection, was evaluated for human STHs and linear regression formulas were developed to estimate eggs per gram (EPG) from Ct values for N. americanus, Trichuris, and Ascaris spp., demonstrating superiority of qPCR in accurately estimating egg numbers and in detecting < 5 EPG in faecal samples. These results showed the utility of qPCR for quantitative estimation of infection levels, differentiation of hookworm species for One Health measures, and evaluation of intervention programs in low infection settings. Additionally, Chapter 6 evaluated how sample storage conditions affect egg development and influence infection intensity estimates based on Ct values particularly in the context of large-scale STH surveys in endemic countries. This study highlighted a substantial difference between qPCR estimates of embryonated and non-embryonated seeded eggs experiments.
Finally, in Chapter 7, the developed formulas and molecular techniques were employed to assess the success of bi-annual mass drug administration (MDA) in school-age children. Further, zoonotic transmission of STHs between children and their cohabiting dogs was investigated. Results underscored the complexity of controlling these infections in endemic areas where zoonotic species are abundant, emphasising the need to re-evaluate surveillance and control strategies to achieve WHO 2030 targets.
In conclusion, the findings of this doctoral thesis underscore the importance of employing refined diagnostic tools to achieve the WHO's 2030 targets for controlling morbidity attributed to STHs. Additionally, a comprehensive One Health approach that acknowledges the role of animal reservoirs in maintaining these infections in humans will be fundamental to effectively control STH at the regional and global levels
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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