1,721,005 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
Estimating the sequestered load in "Plasmodium falciparum" malaria
Get PDFPlasmodium falciparum, the most highly virulent malaria parasite, still remains a big
threat despite years of research and great advances in the field of science and technology.
The particular virulence of this parasite is believed to be due to the ability of trophozoite
and schizont stages of infected red blood cells to adhere to endothelial vasculature in
various organs. The sequestration of these late stages of the parasite, which makes them
difficult to detect in peripheral blood smears, is an important factor limiting performance
of microscopy, the most widely used method for diagnosing malaria in endemic areas. A
reliable technique for estimating the burden of sequestered parasites would also be an
invaluable tool for investigations of pathogenesis and epidemiological field studies.
The objective of this study was to develop methods for detecting sequestered loads and
correlate the results obtained using these methods with estimates of sequestered loads
obtained from a statistical model. Quantification of either cytoadherence or schizogony
using parasite density or biochemical (host or parasite) markers could resolve current
problems in estimating the total parasite burden in malaria patients.
The current status of malaria diagnosis was addressed by reviewing the performance of
the following available diagnostic methods: standard optical microscopy; histidine rich
protein 2 (HRP2); parasite lactate dehydrogenase (pLDH); acridine orange; quantitative
buffy coat. These methods are not 100% sensitive and are not reliable for detecting low
density malaria infections. Biochemical assays were established for the detection of the
stage specific release of parasite biochemical markers in vitro: HRP2; pLDH and Dlactate.
These assays together with an assay detecting the host marker soluble tumour
necrosis factor (sTNF-R75) were then analysed in a small group of 30 month old children
to establish the performance of these assays in measuring markers in vivo. The disease
severity was evaluated using the quantitative HRP2 method developed in 366 children
aged 12 to 59 months. These children had different symptoms: 98 severe malaria, 92
mild malaria, 76 asymptomatic parasitaemia and 100 with no malaria. Having
determined suitable candidate markers for determination of sequestered loads, we then
evaluated a series of host markers: sTNF-R75, circulating host DNA, packed cell volume
(PCV) and parasite markers: HRP2, pLDH, pigmented polymorphonucleated cells
(PMNs) and pigmented monocytes, circulating parasite DNA (pDNA) in a series of 22
patients with severe Plasmodium falciparum malaria treated with quinine. We closely
monitored the peripheral parasite density and used these to obtain estimates of
sequestered loads from an established statistical model that inco-oporates the effects of
quinine.
The main findings were:
i. HRP2 dipsticks perform better than microscopy in detecting P falciparum
infections in clinical cases in endemic areas, while pLDH dipsticks are suitable
for monitoring response to treatment.
ii. P. falciparum releases stage specific products into culture supernatant with pLDH
enzyme activity measured after schizont rupture, while HRP2 is released at
trophozoite and during schizont rupture and the amounts at this later stage are
greatly increased. Both these biochemical markers are good candidate markers of
sequestration though their release is altered by antimalarial administration. Dlactate
is released by all stages of the parasite life cycle.
iii. The methods developed for HRP2, pLDH and a commercially available method
that measures a host molecule sTNF-R75 are suitable for distinguishing children
with severe and mild malaria from healthy controls with or without P. falciparum.
iv. The quantitative HRP2 method together with peripheral parasite densities could
provide a better way of determining malaria disease severity.
v. On admission of young children the markers that appeared to be most useful as
predictors of sequestered loads were peripheral parasite densities, circulating
pDNA and sTNF-R75. However, these and all the other markers did not appear
to be good indicators of changes in sequestered load during the course of a
clinical episode.
Though we were unable to estimate the sequestered load using host or parasite
biochemical markers in partially immune patients, we were able to exclud some
candidates: D-lactate; pigmented PMNs, pigmented monocytes, PCV and circulating host
DNA. Though sTNF-R75 showed some correlation with sequestered loads its release is
affected by host factors such as genetics and age making it unreliable as a marker of
sequestration. The parasite markers HRP2, pLDH and circulating pDNA should be
further evaluated as potential markers of sequestration. Analyses should consider the
effects of antimalarials on release of these markers, as well as the kinetics of their release
and clearance in vivo
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
Exploring the relationships between pedestrian behaviours and traffic safety attitudes in six countries
No full textThe majority of cross-cultural research on traffic safety has investigated driver behaviour, yet in most low- and middle-income countries, where the weight of the road fatality burden is felt, motorisation rates are significantly lower than in higher-income countries. As such, this approach necessarily excludes large parts of the populations in those settings. In order to investigate the link between traffic safety attitudes and road user behaviours, this study used a self-report measure of pedestrian behaviour, applying it in six countries; Bangladesh, China, Kenya, Thailand, the UK, and Vietnam. Focus was on the relationships between a respondent’s attitude towards risky or rule violating on-road behaviours (of other road users, or more generally, not specific to pedestrians), and the extent to which they reported performing three types of risky pedestrian behaviours (i.e., intentional rule violations, errors in judgement or memory, and aggressive behaviours). Data from a sample of 3,423 individuals was subjected to a series of regression models, revealing significant links between attitudes and pedestrian behaviours in all countries, in all three behavioural factors, after controlling for age, gender, and exposure to the road environment. Differences were found between countries in the strength of these relationships, with weaker connections between attitudes and behaviours in Kenya, and stronger connections in China (with other countries in-between the two). Results are discussed in terms of the need to understand the relationships between social cognitive constructs in the specific country in which a road safety intervention is intended to be implemented
Vulnerable road users in low-, middle-, and high-income countries: validation of a Pedestrian Behaviour Questionnaire
No full textThe primary aim of this study was to validate the short version of a Pedestrian Behaviour Questionnaire across six culturally and economically distinct countries; Bangladesh, China, Kenya, Thailand, the UK, and Vietnam. The questionnaire comprised 20 items that asked respondents to rate the extent to which they perform certain types of pedestrian behaviours, with each behaviour belonging to one of five categories identified in previous literature; violations, errors, lapses, aggressive behaviours, and positive behaviours. The sample consisted of 3423 respondents across the six countries. Confirmatory factor analysis was used to assess the fit of the data to the five-factor structure, and a four-factor structure in which violations and errors were combined into one factor (seen elsewhere in the literature). For some items, factor loadings were unacceptably low, internal reliability was low for two of the sub-scales, and model fit indices were generally unacceptable for both models. As such, only the violations, lapses, and aggressions sub-scales were retained (those with acceptable reliability and factor loadings), and the three-factor model tested. Although results suggest that the violations sub-scale may need additional attention, the three-factor solution showed the best fit to the data. The resulting 12-item scale is discussed with regards to country differences, and with respect to its utility as a research tool in cross-cultural studies of road user behaviour.</p
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
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