1,720,961 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
Understanding and optimising HIV prevention and related outcomes among serodiscordant couples in Africa
Get PDFDaily oral tenofovir-based pre-exposure prophylaxis (PrEP) has recently been shown
to be an efficacious HIV prevention strategy for key populations at high risk of acquiring
HIV-1, including serodiscordant couples. This thesis addresses the following research
question: what is the projected impact and cost-effectiveness of PrEP for serodiscordant
couples in sub-Saharan Africa, and would it be a worthwhile intervention? By using
statistical analysis and mathematical modelling, I answer this question and provide
recommendations for the optimisation of antiretroviral-based HIV prevention this population.
In this thesis, I begin by exploring the effect of the reduced risk of herpes simplex
virus type 2 (HSV-2) acquisition by means of PrEP on the outcomes of an intervention, but
conclude that the supplementary benefit is unlikely to substantially alter the costeffectiveness.
I also perform statistical analysis of daily adherence patterns to PrEP,
according to electronic monitoring, from the Partners PrEP Study and the Partners
Demonstration Project in Kenya and Uganda and find that adherence was high in both
settings. Finally, I adapt a microsimulation model of serodiscordant couples in Africa to
include realistic PrEP adherence patterns, HIV-1 transmission, external partnerships, and
empirical costs. Using this model, I simulate the likely impact and cost-effectiveness of a
PrEP intervention according to characteristics and behaviours of couples in the context of a
clinical trial and a demonstration project. Overall, I conclude that a PrEP intervention could
be cost-effective or cost-saving when targeted to high-risk couples, but is unlikely to be cost-effective
if expected incidence is low. In addition, the utility of PrEP for serodiscordant
couples could be compromised if the resources needed to find high-risk couples are
expensive or if couples are not found easily.Open Acces
The impact and importance of voluntary counselling and testing for HIV in sub-Saharan Africa
Get PDFVoluntary counselling and testing (VCT) for HIV is promoted as a primary prevention
strategy to reduce the heterosexual transmission of HIV in sub-Saharan Africa. A
theoretical framework for the determinants of uptake of VCT and behavioural outcomes
following VCT was developed. Demographic and Health Survey (DHS) data collected
from 2003 to 2005 from ten countries were analysed to test the framework by comparing
nationally representative trends in uptake of testing. Data from a population-based open
cohort study in Manicaland, Zimbabwe was also used to test this framework by analysing
trends in sexual behaviour and behaviour change associated with having received VCT.
DHS data indicate that knowledge of serostatus varied widely between countries and
ranged from 2% among women in Guinea to 27% among women in Rwanda. Despite
these varied levels of testing, univariate analysis showed the profile of testers to be
remarkably similar across countries with respect to socio-demographic characteristics.
Adjusted analyses indicate that a secondary or higher level of education and an awareness
that treatment exists are key determinants of uptake of VCT. Uptake of VCT in the
Manicaland cohort is low, at 8.6% in the most recent survey. Against a background of
behavioural risk reduction in the general population, there was no evidence for additional
risk reduction associated with having received VCT in the Manicaland cohort.
This work provides a baseline for monitoring trends in testing and exploring changes in
the profile of those who get tested as provision of testing and treatment services increase.
Within the Manicaland study population, these results do not provide evidence that VCT
can promote behavioural risk reduction, in a context of background reductions in risk.
Uptake of VCT is expected to increase in this population as treatment becomes available.
It is important that VCT services are monitored and evaluated and the importance of risk
reduction is emphasised through good quality counselling. To succeed as a prevention
measure, VCT must attain a high coverage of the sexually active population and lead to
sustained risk reduction among both infected and uninfected individuals
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
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