1,720,972 research outputs found
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
The area under the waveform as an alternative measure of the photopic negative response.
No full textPURPOSE: To explore how the photopic negative response (PhNR), measured as an area defined by the ERG waveform can be used as complementary or an alternative measure to the traditionally measured PhNR amplitude.
METHODS: A retrospective chart review and data analysis of light-adapted 3.0 ERG records in patients and normal subjects patients aged 18 and older undergoing routine ERG testing was conducted. A new measure was analyzed: area defined by the PhNR curve. It was obtained in two ways: as an area under the ERG waveform (AUW) and an area above the ERG waveform (AAW) with starting points defined by the b-wave peak and time windows ranging from 5 to 45 ms in duration. A linear regression was conducted between PhNR1 amplitude (trough before i-wave), PhNR2 amplitude (trough after i-wave), PhNR AUW, and PhNR AAW. Furthermore, a prediction analysis based on AUW/AAW was conducted where the strongest correlated measures were used to predict the PhNR2 amplitude.
RESULTS: The ERG recordings of 70 patients/135 eyes (52F/18 M, average age: 49.2 ± 15.3 years) and six healthy subjects (1F/5 M, age between 22 and 58) were included in this study. 26 patients had well-defined PhNR2 troughs and were used for prediction analysis. There was good correlation between PhNR1 and PhNR2 amplitudes (r
CONCLUSIONS: Determining and using AAW/AUW for PhNR2 prediction could be a valuable method in cases where the PhNR2 peak is not well defined
Short-term variability of the multifocal ERG in clinical settings.
No full textPURPOSE: The purpose of this study was to evaluate the effect of repeat testing on N1 and P1 amplitudes, signal-to-noise (SNR) ratios, and amplitude ring ratios (RR) in multifocal electroretinography (mfERG).
METHODS: This was a retrospective review of mfERG records from 08/2022 to 05/2023. Patients were tested binocularly with the Espion system (Diagnosys LLC). Only records from patients with repeat mfERG tests at the same appointment were included. N1 and P1 amplitudes, signal-to-noise ratio (SNR), and amplitude ring ratios were evaluated for the first recording (run #1), the second recording (run #2), and the combination of run #1 and run #2 (combined run).
RESULTS: Data was collected for 93 eyes from 47 patients (5 males, 42 females) with a mean patient age of 56.1 ± 17.3 years. No change was observed between run #1 and run #2 for N1 or P1 amplitudes, however amplitudes of the combined run decreased significantly (p \u3c 0.05) compared to run #1 amplitudes for all rings, right and left eyes (except for ring 1 in right eyes). SNR increased significantly from run #1 to run #2 for rings 2-5 (~10%), but not for ring 1. The number of blinks recorded during testing decreased from run #1 to run #2 (p \u3c 0.001). Amplitude ring ratios R5/R4 and R5/R3 did not change significantly from run #1 to run #2, while amplitude R1/R2 ratio decreased significantly (p \u3c 0.05).
CONCLUSION: The change in signal quality from run #1 to run #2 suggests a superior quality signal in the second run. Furthermore, the decreased P1 amplitude in the combined run compared to run #1 should be considered when a clinician uses the combined run for their final report
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
Natural Protection of Ocular Surface from Viral Infections – A Hypothesis
No full textA pandemic outbreak of a viral respiratory infection (COVID-19) caused by a coronavirus (SARS-CoV-2) prompted a multitude of research focused on various aspects of this disease. One of the interesting aspects of the clinical manifestation of the infection is an accompanying ocular surface viral infection, viral conjunctivitis. Although occasional reports of viral conjunctivitis caused by this and the related SARS-CoV virus (causing the SARS outbreak in the early 2000s) are available, the prevalence of this complication among infected people appears low (~1%). This is surprising, considering the recent discovery of the presence of viral receptors (ACE2 and TMPRSS2) in ocular surface tissue. The discrepancy between the theoretically expected high rate of concurrence of viral ocular surface inflammation and the observed relatively low occurrence can be explained by several factors. In this work, we discuss the significance of natural protective factors related to anatomical and physiological properties of the eyes and preventing the deposition of large number of virus-loaded particles on the ocular surface. Specifically, we advance the hypothesis that the standing potential of the eye plays an important role in repelling aerosol particles (microdroplets) from the surface of the eye and discuss factors associated with this hypothesis, possible ways to test it and its implications in terms of prevention of ocular infections
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
Long-term follow-up before and during riluzole treatment in six patients from two families with spinocerebellar ataxia type 7
Full text linkBackground: Currently no curative treatment exists for spinocerebellar ataxias (SCAs). Riluzole repurposing was proposed as a symptomatic treatment in different types of cerebellar ataxia. We report a long-term-follow up under riluzole treatment in SCA type 7.
Methods: Six patients received Riluzole 50 mg twice daily on a compassionate use program for a mean of 4.8 years (range 3.5-9). We measured ataxia onset and progression through the Scale for the Assessment and Rating of Ataxia (SARA), and collected extensive ophthalmological data before and after Riluzole treatment. Electrocardiogram and laboratory profile for drug safety were performed every six months.ResultsRiluzole treatment showed no effect on visual function in two patients with an advanced retinal damage. Improvements of visual function occurred in four patients followed by ophthalmologic stability up to 5 years after starting treatment. Two patients had a less steep deterioration of ataxia after treatment compared to pre-treatment, during the first 2,5 years of therapy. One showed soon after therapy an improvement of the SARA score, and then overall stability lasting 3,5 years, followed by ataxia worsening. One visually impaired patient without neurological impairment did not worse until the last visit after 3,5 years of follow-up. The remaining 2 patients showed an improvement of SARA scores soon after therapy, and an overall stability lasting respectively 5 and 3 years. No adverse event was registered during the observation period.
Discussion: This study suggests a possible beneficial action of Riluzole in SCA7 and provides a detailed description of the ophthalmologic profile of these patients
- …
