1,720,999 research outputs found
Testing VA: Do symmetrical charts make a difference?
No full textData on 117 subjects over seven years of age were obtained to determine whether there is a difference in the results obtained from visual acuity charts that use only letters with lateral symmetry and those that use a combination of letters with and without this symmetry. Subjects with acuities of 6/9 or better were used to overcome the problems associated with difference in letters on the 6/60 to 6/18 lines, such as the number of letters, their spacing on a line, and the spacing between lines. The results showed a highly significant statistical difference (p=0.0001) between the two charts, with the charts that use only letters with lateral symmetry giving a better result of on average, 0.49 letters. This means that on approximately every second test, an eye tested on a chart with lateral symmetry would read one more letter than one tested on a chart with letters with and without symmetry. It is unlikely that clinical decisions would be based on this small difference. These findings should only be generalised to subjects with good visual acuity
Casting a wide net: technical challenges of podcasting within a "Standard Operating Environment"
No full textThe attractiveness of podcasting as an alternative form of lecture delivery is immediately apparent to any end user of the technology. The students using client-based software to access the information face the “simple‿ part of RSS (Really Simple Syndication), whereas the lecturer/producer often faces the more complex issues involved in making the material available in the first place. This paper will describe the experience of providing a podcast version of a lecture series under the restrictions of a University “Standard Operating Environment‿, which imposes structures, methods and tools, which may not be designed for the purpose in which they are now being used. An argument will be made for a more flexible structure to allow podcasting to become available to lecturing staff who possess fewer technical skills
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
No full text“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
No full textWe 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
The effect of room illumination on visual acuity measurement
No full textAlthough a number of parameters have been standardised when testing visual acuity (including chart distance, optotypes and luminance of the chart), there is considerable variation in room lighting conditions used. Currently no research exists which either suggests a particular room illumination, or even if there is any difference in visual acuity with different room lighting conditions. The purpose of the current study was to determine whether changes in room illumination affect the level of distance visual acuity recorded. Visual acuity was randomly tested on 50 subjects (98 eyes) using the standard Snellens chart in two different room illumination levels, with normal room illumination (with room lights on - 1300 lux ) and with reduced room illumination (with room lights off - 90 lux). Residual refractive error (difference between spectacle correction and autorefraction) was calculated and pupil size measured in each condition. Overall a significant difference in visual acuity between the two lighting conditions was found with visual acuity levels improving with room illumination (6/9+4 in illuminated room, 6/9+2 in non-illuminated room; t=4.653, p<0.001). The difference was found to be greater in the non-emmetropic group (6/12+3 in illuminated room, 6/12 in non-illuminated room). There was a small subgroup of subjects' eyes where the visual acuity level dropped by more than one line in the non- illuminated room (n=18). The reason for this difference may be related to optical influences on visual acuity such as accommodation and night myopia
Moss, Nathan
No full textSee entry in Perry County, volume 3, page 3: https://digital.archives.alabama.gov/digital/collection/voter1867/id/264
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