1,720,954 research outputs found
In vivo dynamic light scattering changes of the vitreous in diabetes mellitus
No full textPurpose. Dynamic light scattering (DLS) is a well known non-invasive diagnostic tool used in the anter or segment. In this study in vivo DLS measurements of the human vitreous have been performed to detect changes during the course of diabetes mellitus both with and without diabetic retinopathy. Material and Methods. 50 diabetes mellitus patients with ocular complications varying form no diabetic retinopathy through to severe diabetic retnopathy were examined using DLS techniques. Measurements were performed at different topographical locations of the vitreous, the retrovitreal space and the retina. The results were compared to measurements of 50 normal subjects. Results. The autocorrelation function obtained from the DLS signal in the normal vitreous exhibits two peaks which correspond to the contribution from macromolecules These peaks were found to alter, either in applitude or location, during the course of diabetic retinopathy. The degree and form of these alterations was correlated to the severity of the ocular complicatons in the structures investigated. DLS measurements in the cornea exhibited similar effects to those made in the vitreous. Conclusions. DLS is capable of detecting the changes of the vitreous associated with diabetes mellitus. Moreover, due to the close correlation of the DLS results with the severity of viteo-retinal changes, DLS may serve as an important tool for the early diagnosis and monitoring of ocular complications due to diabetes mellitus
In vivo dynamic light scattering measurements in the cornea of the human eye prior to and after excimer laser refractive surgery
No full textPurpose. Dynamic light scattering (DLS) can be used as a non-invasive optical probe for in vivo molecular diagnostics in the human eye. The purpose of this pilot study is to demonstrate the detectability of changes in the molecular structure of the human cornea after excimer laser photorefractive keratectomy (PRK) or phototherapeutic keratectomy (PTK). Material and Methods. 10 patients underwent excimer laser treatment, either for the correction of myopia (PRK) or for therapeutic reasons (PTK). DLS measurements of the corneal stroma were performed prior to and after (immediately, 1 day, 5, 10 days, 1 month, 3 months) treatment. Measurements were perfomed at different topographical locations both inside and outside the treated areas of the corneal stroma. Results. The autocorrelation function obtained from the DLS signal exhibits two peaks corresponding to the fast and slow components of the stroma. After excimer laser treatment the location as well as the amplitude of these peaks were significantly altered. These alterations did not correlate to the ablation depth during treatment nor to the pre-operative refractive error. Only minor corneal haze was observed which showed no statistically significant correlation with alterations of the peaks. No formation of corneal scars was observed in any patient. Conclusions. DLS seems to be a suitable tool for observation of the wound healing processes in the cornea after treatment by excimer laser. Due to the limited number of cases, statistically significant results are not yet available. Ongoing investigations involving a larger number of cases may reveal the power of DLS for diagnosis of abnormal healing processes
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
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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