1,720,961 research outputs found
Systemic Vascular Dysregulation and Retrobulbar Hemodynamics in Normal-Tension Glaucoma
No full textPurpose. To investigate the influence of systemic vascular dysregulation on retrobulbar hemodynamics in normal-tension glaucoma (NTG). Methods. Forty-four untreated patients with NTG and 40 healthy controls matched for age, sex, and intraocular pressure were included. Cold-induced nailfold capillaroscopic features, mean and diastolic ocular perfusion pressures (mOPP, dOPP), endothelin-1 (ET-1) and nitric oxide markers, as nitrates (NO 2), plasma values were recorded. Peak-systolic velocity, end-diastolic velocity (EDV), and resistivity index (RI) were measured in the ophthalmic artery (OA), short posterior ciliary arteries, and the central retinal artery by color Doppler imaging. Differences between groups were determined by Student's t-test. Relationships among ET-1, NO2, OPPs, and retrobulbar hemodynamics were assessed using correlation and multiple linear regression analyses. Results. Altered capillaroscopy was more frequent (72.7% vs. 5.0%, P < 0.001), mOPP and dOPP values were lower (44.54 ± 2.81 vs. 52.18 ± 4.47 mm Hg; 57.89 ± 4.30 vs. 68.28 ± 6.91 mm Hg; P < 0.001), and ET-1 and NO 2 values were respectively higher and lower (1.62 ± 0.22 vs. 1.12 ± 0.20 pg/mL and 142.17 ± 14.34 vs. 231.30 ± 6.16 μmol/mg prot; P < 0.001) in patients than the same values in controls. EDV was lower and RI higher in OA (5.87 ± 1.17 vs. 11.41 ± 2.30 cm/s; 0.76 ± 0.03 vs. 0.64 ± 0.03; P < 0.001) in subjects with NTG than in controls. In patients RI-OA was positively related to ET-1 (t = 2.704, P = 0.010) and negatively related to NO2 (t = -4.477, P < 0.001). Conclusions. Impaired retrobulbar hemodynamics may proceed from a vascular endotheliopathy in patients with NTG. © 2011 The Association for Research in Vision and Ophthalmology, Inc
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
Multifocal electroretinographic responses in sector retinitis pigmentosa
No full textHeadings: Multifocal electroretinography (mfERG) may be useful in the management of sector retinitis pigmentosa (SRP). Aim: To compare multifocal electroretinographic responses in SRP, generalised retinitis pigmentosa (GRP), and healthy controls. Methods: Eighteen patients with SRP, twelve with GRP, and fifteen controls were included in the study. All participants underwent: complete ophthalmological examination, Humphrey visual field testing, full-field ERG, and mfERG. The mean P1 amplitude, the implicit time (IT), and the mapping of the local responses were evaluated. Results: The mean P1 amplitude was higher in the SRPs than in GRPs (p < 0.001), while it did not differ between SRPs and controls (p = 0.913). In the SRPs, the P1 amplitude in pathologic areas was higher than in the GRPs (p < 0.001). In normal areas, this parameter did not differ from the controls (p = 0.499). Moreover, in the SRPs, no differences in the P1 amplitude and the IT between pigmented and non-pigmented areas were found. Conclusion: In the present study, the mfERG examination displayed significant differences between sector and generalised RP, showing normal values in sector RP even in pigmented areas. Considering the patients included in this study, SRP seems to represent a favourable variant of the disease, characterised by a limited retinal involvement and apparently mild functional damage. It is still unclear how these results can be extended to other forms of SRP
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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