1,721,083 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Tuberculous meningitis: reducing the burden of disease by improving diagnosis and treatment
Full text linkNotwithstanding available diagnosis and treatment, tuberculosis (TB) is the most persistent pandemic
known to modern man. Of all forms of tuberculosis, tuberculous meningitis (TBM) is the most lethal.
The true burden of disease is unknown, but of the people who reach treatment facilities,
approximately 30% die, despite therapy. The onset of disease is insidious and diagnosis is often only
made after neurological compromise, a factor associated with increased mortality. Diagnosis is further
complicated by lack of sensitivity of currently available conventional microbiological techniques.
Moreover, recommended treatment regimens are derived from pulmonary TB regimens and not
specifically adjusted to treat the infection in the brain, thus neglecting the differential ability of
antimycobacterial drugs to cross the blood-brain barrier (BBB). Similarly, drug resistant infection is
mostly detected late, because it depends on culture confirmation of this slow growing organism and
optimal treatment regimens are unknown. In the context of intracranial infection, drug resistance is
even more precarious, with high rates of mortality reported.
This thesis addresses these pressing issues of diagnosis and treatment of TBM. The overarching aims
of the studies performed in this thesis are: 1. To improve diagnosis of TBM by evaluating the
performance of a novel molecular diagnostic test; Xpert MTB/RIF, 2. To improve treatment of TBM
by evaluating an intensified antituberculosis treatment regimen. 3. To improve management of drug
resistant TBM by exploring factors associated with drug resistance and evaluating response to
intensified treatment.
The Xpert MTB/RIF test was able to rapidly confirm a diagnosis of TBM with a sensitivity of 59.3%
(n=108/182 (95% confidence interval(CI): 51.8-66.5)) compared to clinical diagnosis of TBM.
Specificity was 99.5% (95% CI: 97.2-100). Particular advantages are the high sensitivity of the test in
HIV positive patients and early detection of rifampicin resistance. Among HIV co-infected patients,
sensitivity was 78.8% (n=52/66, (95% CI: 77.6-79.7)). Xpert MTB/RIF performance compared
favourably with performance of commonly used classical staining techniques in most settings (1-
6
60%). This represents a significant advance in the early diagnosis of TBM and in particular of
rifampicin resistance, which is considered a key drug in treatment regimens. Intensified
antituberculosis treatment with higher dose rifampicin (15mg/kg) and additional levofloxacin,
however, did not improve outcome in our cohort of 817 HIV infected (n=349) and uninfected (n=468)
TBM patients. 113 and 114 patients died in the intensified treatment and placebo arm respectively
(hazard ratio(HR), 0.94; 95% CI: 0.73 -1.22, p=0.66). Overall 9-month mortality was 28%, which is
still unacceptably high. Predictors of death are HIV infection, disease severity grade on presentation
and infection with multidrug resistant (MDR) mycobacteria, defined as at least resistance to
rifampicin and isoniazid. The overall mycobacterial resistance rate found in this population was high;
45% of isolates showed resistance to at least one of four first line antituberculosis drugs, 27% were
isoniazid resistant and MDR was detected in 5%. Patients with drug resistant infection did not have
different presenting symptoms, but were more likely to have a history of previous TB treatment. Early
intensified treatment did appear to be beneficial to outcome, in particular in HIV uninfected patients
with isoniazid resistance (HR 0.11; 95%CI: 0.01-0.91, p=0.04). Of the 15 patients with MDR TBM,
early detection of rifampicin resistance by Xpert MTB/RIF led to a successful early switch to second
line therapy in four patients, who all survived up to nine months of follow up. In previous studies,
prior to the availability of Xpert testing and secondline drugs, MDR TBM was uniformly lethal.
Early diagnosis and treatment with effective antituberculosis drugs remains the most crucial aspect of
management of this devastating condition.</p
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
Data for 'Identification of bacterial determinants of tuberculosis infection and treatment outcomes: a phenogenomic analysis of clinical strains'
No full textAccession: PRJNA95096
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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