1,720,963 research outputs found
Screening of malaria infections using AI-powered infrared spectroscopy
Get PDFOver the past two decades, malaria control efforts have averted 2.1 billion cases and saved 11.7 million lives globally, yet the disease still claims over 600,000 lives annually, mostly in sub-Saharan Africa. Key interventions like insecticide-treated nets, indoor spraying, and antimalarial drugs have driven success, but major challenges persist. Accurate, timely detection of malaria parasites and scalable population screening remain difficult, especially in low transmission areas. Although WHO promotes surveillance as a core pillar of elimination, resource constraints in low-income countries hinder the expansion of effective, affordable surveillance systems. Current malaria screening tools, such as rapid diagnostic tests (RDTs) and microscopy, are essential for detecting parasites but have limitations, particularly in low transmission settings and at low parasite densities, which hampers elimination efforts. While more sensitive methods like polymerase chain reaction (PCR) are available, they are costly and impractical for widespread use in resource-limited areas. As a result, there is an urgent need for sensitive, cost-effective, and scalable tools capable of detecting low-density infections, especially in low transmission contexts.
Recent studies have shown the potential of using artificial intelligence (AI) powered infrared spectroscopy to detect malaria parasites in human blood. This approach is reagent-free, robust, user-friendly, quick and potentially cost-effective. However, to address the gaps in current methods for malaria screening and diagnosis, it was important to also assess factors such as lowest detectable parasite density and performance in low transmission settings before adoption by malaria control programs.
The primary aim of my PhD research was to improve malaria surveillance by exploring the application of infrared spectroscopy and machine learning (IR-ML) for malaria screening in population surveys. To achieve this, I pursued five complementary objectives: (1) reviewing the potential applications of IR-ML for malaria surveillance, developing a target product profile, and identifying key considerations and research gaps for integrating IR-ML into control efforts; (2) demonstrating the performance of mid-infrared spectroscopy and machine learning (MIRs-ML) across varying parasite densities and anaemic conditions; (3) conducting cross-sectional surveys to map malaria burden in an endemic setting, assessing the performance of existing methods (RDTs, microscopy, and qPCR) for risk stratification; (4) evaluating MIRs-ML performance in areas with differing prevalence rates; and (5) developing a web-based platform to deliver MIRs-ML results to end users. The ultimate goal was to advance the development of MIRs-ML as a scalable malaria screening tool, adaptable to both high (prevalence rate >30%) and low transmission (prevalence rate <5%) settings, with the potential to transform malaria detection and monitoring.
To achieve the first objective, I reviewed the current state of infrared spectroscopy and machine learning (IR-ML) for malaria surveillance, comparing its advantages and limitations to existing tools like PCR, RDTs, and microscopy. This review identified research gaps and developed a target product profile (TPP) for integrating infrared technology into routine surveillance. For the second objective, I conducted lab experiments using blood from 70 malaria-free volunteers in Tanzania, diluted with cultured Plasmodium falciparum to create different parasitemia and anemia levels. These samples were used to create dry blood spots, which were then scanned using ATR-FTIR spectroscopy. Using supervised machine learning classifiers trained on a subset of the samples, we achieved over 90% accuracy in detecting malaria, even at low parasite densities, and across different anemia conditions. Field applications of these models demonstrated over 80% accuracy in predicting natural infections.
The third and fourth objectives involved cross-sectional surveys in 93 sub villages in southeastern Tanzania, screening 7,628 individuals using RDTs and microscopy, with two-thirds analyzed by qPCR. qPCR consistently detected higher transmission rates, revealing that RDTs and microscopy underestimate malaria prevalence, particularly in fine-scale mapping. I then used the survey data to evaluate MIRs-ML performance in areas with varying malaria prevalence rates from low to high. Again, the ML classifiers achieved over 90% accuracy and sensitivity in both high and low transmission settings. We also observed that performance was slightly lower in low transmission areas when trained exclusively on high transmission data, compared to when the models were trained with data from across all settings.
Finally, to make these models readily available to users in future, we developed a web-based platform that allows scientists and national programs to access pretrained ML models for instant malaria infection predictions. This platform is currently powered by models trained on over 5,000 human blood samples and 40,000 mosquitoes, and will continue to expand with data from Tanzania, Burkina Faso, and the UK. The ultimate goal is to democratize the applications of these models across different user groups in different countries.
In conclusion, through population surveys, I demonstrated the limitations of RDTs and microscopy for mapping malaria risk. I developed MIRs-ML in the lab to overcome these challenges and tested it in the field, showing its promise. This research has significantly advanced our understanding of the potential of MIRs-ML for malaria screening. It has demonstrated that the approach has high sensitivity and is capable of detecting parasite levels as low as one parasite/μl of blood, making it particularly suitable for large-scale population surveys and enhancing risk stratification efforts. The study also highlighted the limitations of current screening tools, such as RDTs and microscopy, which perform poorly in low transmission settings compared to the more sensitive PCR. This underscores the urgent need for new, more sensitive approaches for precise stratification. This PhD research shows that MIRs-ML could meet these needs, making it a valuable complement to existing surveillance methods and a promising tool for malaria screening, even in low transmission areas
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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