1,721,081 research outputs found
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
Determinants and consequences of failure of linkage to antiretroviral therapy at primary care level in Blantyre, Malawi: a prospective cohort study.
Get PDFBACKGROUND: Poor rates of linkage from HIV diagnosis to ART initiation are a major barrier to universal coverage of ART in sub-Saharan Africa, with reasons for failure poorly understood. In the first study of this kind at primary care level, we investigated the pathway to care in the Malawian National Programme, one of the strongest in Africa. METHODS AND FINDINGS: A prospective cohort study was undertaken at two primary care clinics in Blantyre, Malawi. Newly diagnosed HIV-positive adults (>15 years) were followed for 6-months to assess completion of eligibility assessments, initiation of ART and death. Two hundred and eighty participants were followed for 82.6 patient-years. ART eligibility assessments were problematic: only 134 (47.9%) received same day WHO staging and 121 (53.2%) completed assessments by 6-months. Completion of CD4 measurement (stage 1/2 only) was 81/153 (52.9%). By 6-months, 87/280 (31.1%) had initiated ART with higher uptake in participants who were ART eligible (68/91, 74.7%), and among participants who received same-day staging (52/134 [38.8%] vs. 35/146 [24.0%] p = 0.007). Non-completion of ART eligibility assessments (adjusted hazard ratio: 0.11, 95% CI: 0.06-0.21) was associated with failure to initiate ART. Retention in pre-ART care for non-ART initiators was low (55/193 [28.5%]). Of the 15 (5.4%) deaths, 11 (73.3%) occurred after ART initiation. CONCLUSIONS: Although uptake of ART was high and prompt for patients with known eligibility, there was frequent failure to complete eligibility assessment and poor retention in pre-ART care. HIV care programmes should urgently evaluate the way patients are linked to ART. In particular, there is a critical need for simplified, same-day ART eligibility assessments, reduced requirements for hospital visits, and active defaulter follow-up
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
Spatiotemporal heterogeneity and bias in respiratory infection surveillance
Get PDFParameter estimation of respiratory infection surveillance dynamics commonly utilize data aggregated over space and time. However, estimates derived from aggregated data may fail to account for biologically meaningful spatiotemporal heterogeneity of effects or to identify where and when transmissions occur. This dissertation shows that high-resolution temporal and spatial data can improve our understanding of heterogeneity while producing more valid and precise estimates of transmission parameters (e.g., contagiousness), behavioral trends (e.g., face mask utilization), and intervention effects (e.g., at-home test distribution). In three projects, we evaluate spatiotemporal heterogeneity in the context of two major respiratory pathogens: Tuberculosis and SARSCoV-2.
First, in project one, we identify disease transmission hotspots from a tuberculosis case surveillance system in Greater Vitória, Brazil. Utilizing a human mobility model and recently developed method to quantify disease transmission, we overcome multiple methodological constraints that often obscure spatially and temporally accurate transmission measurements. We estimate that two cities in Greater Vitória, Vila Velha (reproductive number = 1.05, 95%CI: 1.03–1.07) and Vitória (reproductive number = 1.04, 95%CI: 1.02–1.06), help sustain tuberculosis transmission in the entire region and may be effective targets for intervention, while Cariacica (reproductive number = 0.95, 95%CI: 0.94–0.97) fell below the critical threshold of 1 required to sustain transmission alone.
Next, in project two, we utilize interrupted time series methods to estimate the effect of mask mandates on mask adherence using a nationally representative digital health survey on masking and a comprehensive database of pandemic-related government policies. The analysis focuses on improving previous attempts at measuring the effectiveness of mask mandates at the state level, by utilizing county-level exposure and outcome data. We find that mask mandates were associated with a large heterogeneity of effects, ranging from increasing masking approximately 8% in counties with low levels of prior masking to 1% or lower change in masking in places like the Northeast U.S. where masking levels were already high.
Last, in project three, we leverage the same nationally representative digital health survey to understand at-home testing patterns in the United States. We utilize two different economic measures of resource allocation and a regression model with autoregressive integrated moving average errors to examine if the Covidtests.gov government program reduced at-home testing inequities. We show that Covidtest.gov did increase at-home testing across all demographics; however, income-, geographic- and race-based disparities in at-home test utilization were heightened during periods when the program was active. Specifically, the regression results estimate that Theil’s T, an economic metric used here to measure at-home testing disparities, was 53% (95%CI: 6%–121%) higher for household income, 214% (95%CI: 86%–429%) higher for race, and 90% (95%CI: 23%–193%) higher for geography during Covidtest.gov dissemination periods. Disparities were not elevated for age.
Together, these three projects demonstrate the substantial role that high-resolution data can play in improving our understanding of respiratory infection surveillance and informing effective public health interventions
Assessment of cardiovascular disease risk factors and treatment using longitudinal data
Get PDFCardiovascular disease (CVD) mortality rates have been declining in the modern era with improved clinical care and better risk factor control. However, CVD remains the leading cause of death in the United States and is projected to affect approximately 45% of the population in the next 15 years. As randomized controlled trials are not always feasible, the use of longitudinal data to identify risk factors and effective treatment for primary and secondary prevention of CVD is essential. The aim of this dissertation was to conduct three studies that assess the risk of second major CVD events after a first CVD event, the effect of moderate alcohol consumption on stroke risk, and the effect of treatment for hypertension using a quasi-experimental design.
In study one, I used data from the Framingham Heart Study to describe the risks of five CVD and mortality outcomes after a first major CVD event. I also assessed how the risk of a second CVD event differs from the risk of a first CVD event. I found that those who have experienced a first CVD event have a higher risk of CVD-related mortality and heart failure as a second CVD event compared with the risk of a first major CVD event. I also found that individuals whose first CVD type was myocardial infarction or heart failure had the highest risk of experiencing heart failure as a second event; those whose first CVD type was a stroke had the highest risk of mortality or a recurrent stroke.
In study two, I used data from the Veterans Affairs Million Veteran Program to estimate the effect of moderate alcohol consumption on the risk of ischemic and hemorrhagic stroke compared with never drinking, and assessed if primarily drinking wine, beer or liquor is associated with a difference in stroke risk compared with drinking a mixture of beverage types. I observed that moderate alcohol consumption was associated with a reduced risk of stroke; however, stratified analyses by age and number of previous hospital visits provided some evidence that healthy survivor bias and residual confounding may have impacted the observed protective effect. I did not observe a difference in strong risk among those who primarily drink wine or beer, and a slight increase in stroke risk in those who preferred liquor, compared with those who have no beverage preference.
In study three, I used Veterans Health Administration electronic health record data and a regression discontinuity design to estimate the effect of eligibility for antihypertensive treatment for patients with stage 1 hypertension, defined using national guidelines, on lowering blood pressure. I found that the blood pressure guidelines were associated with a small increase in antihypertensive treatment initiation and controlled blood pressure within 24 months. I also observed a reduction in blood pressure when estimating the effect of actual treatment among those with hypertension compared with those who were not on treatment
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