1,720,980 research outputs found
Prevalence and risk of progression of preclinical Alzheimer's disease stages: A systematic review and meta-analysis
No full textBackground: Alzheimer's disease (AD) pathology begins several years before the clinical onset. The long preclinical phase is composed of three stages according to the 2011National Institute on Aging and Alzheimer's Association (NIA-AA) criteria, followed by mild cognitive impairment (MCI), a featured clinical entity defined as "due to AD", or "prodromal AD", when pathophysiological biomarkers (i.e., cerebrospinal fluid or positron emission tomography with amyloid tracer) are positive. In the clinical setting, there is a clear need to detect the earliest symptoms not yet fulfilling MCI criteria, in order to proceed to biomarker assessment for diagnostic definition, thus offering treatment with disease-modifying drugs to patients as early as possible. According to the available evidence, we thus estimated the prevalence and risk of progression at each preclinical AD stage, with special interest in Stage 3. Methods: Cross-sectional and longitudinal studies published from April 2008 to May 2018 were obtained through MEDLINE-PubMed, screened, and systematically reviewed by four independent reviewers. Data from included studies were meta-analyzed using random-effects models. Heterogeneity was assessed by I 2 statistics. Results: Estimated overall prevalence of preclinical AD was 22% (95% CI = 18-26%). Rate of biomarker positivity overlapped in cognitively normal individuals and people with subjective cognitive decline. The risk of progression increases across preclinical AD stages, with individuals classified as NIA-AA Stage 3 showing the highest risk (73%, 95% CI = 40-92%) compared to those in Stage 2 (38%, 95% CI = 21-59%) and Stage 1 (20%, 95% CI = 10-34%). Conclusion: Available data consistently show that risk of progression increases across the preclinical AD stages, where Stage 3 shows a risk of progression comparable to MCI due to AD. Accordingly, an effort should be made to also operationalize the diagnostic work-up in subjects with subtle cognitive deficits not yet fulfilling MCI criteria. The possibility to define, in the clinical routine, a patient as "pre-MCI due to AD" could offer these subjects the opportunity to use disease-modifying drugs at best
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
The Italian version of Cognitive Function Instrument (CFI) for tracking changes in healthy elderly: results at 1-year follow-up
No full textCognitive Function Instrument (CFI) is a questionnaire aimed at detecting very early changes in cognitive and functional abilities and useful for monitoring cognitive decline in individuals without clinical impairment. The Italian version has been recently validated. The aim of the present study was to investigate the utility of the Italian version of CFI in tracking early cognitive changes in a cohort of healthy elderly subjects. A consecutive series of 257 cognitively healthy and functionally independent subjects, recruited either among relatives of patients attending our Memory Clinic or as volunteers after advertisement, underwent a baseline neuropsychological assessment. Of them, 157 subjects performed a 1-year follow-up assessment. All subjects completed the CFI, a short questionnaire composed of 14 items administered to both the subject and the referent (study-partner). Cognitive performance was assessed by Mini-Mental State Examination (MMSE) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). At 1-year follow-up, Cronbach’s α was 0.79 (95% CI, 0.74–0.84) in self-report and 0.83 (95% CI, 0.79–0.87) for partner-report. CFI self-report correlated with MMSE (rS = − 0.22, p = 0.006) and RBANS (rS = − 0.23, p = 0.004). CFI partner-report showed negative correlation with MMSE (rS = − 0.17, p = 0.037) and RBANS (rS = − 0.20, p = 0.014). CFI 1-year follow-up score correlated with baseline both in self-report (rS = 0.56, p < 0.001) and partner-report (rS = 0.66, p < 0.001). Baseline CFI partner-report (p = 0.014) and CFI self+partner report (p = 0.023) were associated with RBANS total score less than 85 at 1-year follow-up, while only a trend was found considering baseline CFI self-report. Our results support the suitability of the Italian version of CFI for tracking cognitive changes along aging
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
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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