1,720,974 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
Investigating the effect of perceptual and conceptual similarity upon older adult false recognition rates
No full textExploring frailty and cognitive functioning trajectories in later life
Get PDFUnderstanding the ageing process in later life is a crucial step in identifying
those at highest risk of health decline, and in implementing effective
prevention and treatment strategies. However, measuring the ageing process
is a complex and divisive issue. As chronological age does not necessarily
capture the vast heterogeneity of older age, we require the development of
quantifiable health states. This thesis explored two of these states: Frailty
and mild cognitive impairment. A consensus on the concept of frailty and
how it should be measured remains elusive; however, it is generally
understood to describe a state of higher vulnerability to adverse events such
as disease, disability, dementia, and death. Mild cognitive impairment (MCI)
is a health state that describes a borderland between normal cognitive
functioning and dementia, exhibited by mild subjective and objective
cognitive impairments but a retained independency and ability to undertake
activities of daily living. This thesis explored later life ageing trajectories using
these health states and ultimately sought to provide a foundation for further
research and clinical care to build upon.
The first study acts as an introduction to the concept of frailty by conducting a
systematic review of publications that explore frailty trajectories. After
screening 8,318 publications, 25 met the eligibility criteria. Findings showed
that the field has a considerable degree of heterogeneity in how studies
measure frailty, the statistics they use to interpret their results, and the types
of populations they sample. Despite this, some valuable conclusions can be
made: as expected, frailty increases with age, and these increases are
consistently associated with certain factors such as socioeconomic factors,
social support, physical activity, and brain pathologies. I conclude that more
longitudinal research is required in the field, specifically research that
compares and contrasts the ways in which frailty is quantified.
The second study investigated the association between chronic inflammation
and frailty trajectories in the Lothian Birth Cohort 1936. Using two common
measures (Frailty index and Fried phenotype) and two blood-based
inflammatory biomarkers (Fibrinogen and C-reactive protein), frailty is tracked
over approximately 12 years. Findings showed that Fibrinogen was
significantly associated with higher baseline Frailty index score (β = 0.011,
95% CI [0.002, 0.020], p < .05). Additionally, over the 12-year follow-up,
higher baseline C-reactive protein (β = 0.001, 95% CI [0.000, 0.002], p < .05)
and Fibrinogen (β = 0.004, 95% CI [0.001, 0.007], p < .05) were both
significantly associated with increased Frailty index change. For the Fried
phenotype, higher baseline inflammation biomarkers were associated with
higher baseline frailty status (p < .001), but there were no significant
associations over the 12-year follow-up. Accordingly, inflammation appeared
to be associated with higher rates of frailty over time but the way in which you
measure frailty can affect this association.
The third study aimed to explore the heterogeneity of frailty trajectories and
account for the probability that not all individuals follow the same path. Using
a quadratic latent class mixed model, subpopulations of frailty trajectories
were identified over approximately 12 years in the Lothian Birth Cohort 1936.
Analyses revealed three classes of frailty trajectories which begin at different
intercepts and follow different slopes: Low (61%, n = 632), Medium (36%, n =
368), or High (3%, n = 28). Those in the Low class were younger, had higher
education, higher age 11 cognitive ability, and were from a higher social
class when compared to those in either Medium or High classes. These
findings help to demonstrate the heterogeneous nature of frailty progression
and indicate that not all older adults will follow a similar path. This has clinical
implications for identifying those on steeper trajectories and implementing
effective prevention strategies.
The fourth study shifted focus to the cognitive aspects of later life decline by
exploring the health state known as mild cognitive impairment or MCI. This
study introduced the concept and detailed how it was coded and
implemented in the Lothian Birth Cohort 1936. MCI is implemented at three
waves of the cohort at ages 76 (n = 567), 79 (n = 441), and 82 years (n =
341). In line with similar cohorts, rates of MCI showed an increase at each
wave between 76 and 82 years from 15% to 18%. Additionally, two subtypes
of MCI were derived: amnestic, which solely considered memory related
cognitive decline, and non-amnestic, which considered non-memory related
cognitive impairments (executive function, attention, language, and
visuospatial skills). These subtypes also showed increases over time in the
cohort, however, the non-amnestic subtype showed rates that were higher
than expected compared to similar cohorts. This study highlighted the
prevalence of MCI in the Lothian Birth Cohort 1936 and opened the door for
further study of cognitive ageing trajectories.
The fifth and final study considered transitions in MCI status and the factors
that may be associated with these changes in the Lothian Birth Cohort 1936.
Progressions and reversions in MCI status between the ages of 76 and 82
years were assessed. At age 76, 14% of the sample had MCI, compared to
19% at age 82. Findings showed that over the six-year period, 74% remained
cognitively healthy, 12% transitioned to MCI, 7% reverted to healthy
cognition, and 7% maintained their baseline MCI status. Multinomial logistic
regression analysis indicated that these transitions are affected by factors
including age, cardiovascular disease, and number of depressive symptoms.
This study illustrates the volatility of cognitive states in later life and highlights
several factors, including depression, which may be associated with these
changes.
This thesis provided an exploration of the ageing process by considering the
trajectories of frailty and MCI in the Lothian Birth Cohort 1936. The findings
contribute to an expanding field of longitudinal research, which hopes to
understand how health statuses like frailty and MCI change over time, and
the salient factors associated with these changes. Incremental advances like
those seen in the studies in this thesis allow for a better understanding of
how the ageing process affects us in later life, ultimately leading to better
prevention strategies and interventions that allow every individual to follow
their healthiest ageing trajectory
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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