1,721,029 research outputs found
Neuropsychological, Personality, and Cerebral Oxygenation Correlates of Undergraduate Poly-Substance Use
No full textGoing 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
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
Short‐term practice effects are reduced in Subjective Cognitive Decline and predict its trajectory
No full textBackground:
Subjective cognitive decline (SCD), defined as cognitive complaints in the absence of objective cognitive impairments, may reflect the earliest manifestation of preclinical Alzheimer's disease (AD). However, individuals with SCD are a heterogenous group with unclear cognitive and clinical trajectories. Building on our prior work examining short‐term practice effects (STPE) in Mild Cognitive Impairment (MCI) and AD, we examined if STPE were diminished in SCD and if they predicted cognitive trajectories.
Method:
76 participants classified as cognitively unimpaired according to the Jak/Bondi criteria were divided by whether they presented with cognitive complaints (i.e., SCD, n = 11) or not (i.e., CN, n = 65). They completed a brief cognitive battery twice across one week (Time 1 to Time 2) to quantify STPE and again after approximately 1.3 years (Time 1 to Time 3) to assess long term cognitive change.
Result:
Across one week, those with SCD showed smaller STPE on 7 of the 8 neuropsychological test scores and a composite measure compared to those without cognitive complaints (see Figure 1 for the composite; negative Z‐scores reflect smaller STPE). STPE on visual scanning, set shifting, and processing speed showed the largest effect sizes in separating SCD from CN. In the entire sample, the composite measure of STPE was significantly related to change over 1.3 years (r = .31, p = .01), with smaller STPE predicting less improvement at long term follow‐up. When considering the two groups, composite STPE and change over 1.3 years showed similar relationships (CN r = .23 and SCD r = .21). However, when examining processing speed measures specifically, the association between STPE and long‐term changes were stronger in the SCD group (r = .91) than the CN group (r = .38).
Conclusion:
Similar to our work over the past decade in MCI and AD, STPE were reduced in SCD relative to CN, and they predicted cognitive trajectories. As such, these preliminary findings require validation in a larger trial to see if STPE could be used to enrich clinical trials enrolling those with SCD
Application of Different Standard Error Estimates in Reliable Change Methods
No full textObjective: This study attempted to clarify the applicability of standard error (SE) terms in clinical research when examining the impact of short-term practice effects on cognitive performance via reliable change methodology.
Method: This study compared McSweeney's SE of the estimate (SEest) to Crawford and Howell's SE for prediction of the regression (SEpred) using a developmental sample of 167 participants with either normal cognition or mild cognitive impairment (MCI) assessed twice over 1 week. One-week practice effects in older adults: Tools for assessing cognitive change. Using these SEs, previously published standardized regression-based (SRB) reliable change prediction equations were then applied to an independent sample of 143 participants with MCI.
Results: This clinical developmental sample yielded nearly identical SE values (e.g., 3.697 vs. 3.719 for HVLT-R Total Recall SEest and SEpred, respectively), and the resultant SRB-based discrepancy z scores were comparable and strongly correlated (r = 1.0, p < .001). Consequently, observed follow-up scores for our sample with MCI were consistently below expectation compared to predictions based on Duff's SRB algorithms.
Conclusions: These results appear to replicate and extend previous work showing that the calculation of the SEest and SEpred from a clinical sample of cognitively intact and MCI participants yields similar values and can be incorporated into SRB reliable change statistics with comparable results. As a result, neuropsychologists utilizing reliable change methods in research investigation (or clinical practice) should carefully balance mathematical accuracy and ease of use, among other factors, when determining which SE metric to use
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