scholarly journals Spectrally Resolved Fundus Autofluorescence in Healthy Eyes: Repeatability and Topographical Analysis of the Green-Emitting Fluorophores

2020 ◽  
Vol 9 (8) ◽  
pp. 2388 ◽  
Author(s):  
Enrico Borrelli ◽  
Marco Battista ◽  
Biancamaria Zuccaro ◽  
Riccardo Sacconi ◽  
Maria Brambati ◽  
...  
Keyword(s):  
Fundus Autofluorescence ◽  
Intraclass Correlation ◽  
Repeated Measurements ◽  
Excitation Wavelength ◽  
Foveal Region ◽  
Quantitative Metrics ◽  
Topographical Analysis ◽  
Spectrally Resolved ◽  
Level Of Agreement ◽  
Do So

The aim of this study was to report normal measurements of green-emitting fluorophores in the macula of healthy young individuals and to assess the repeatability of these quantitative metrics. To do so, healthy young volunteers were imaged twice (7 ± 3 days apart) using a confocal blue-light fundus autofluorescence (FAF) device with a shorter excitation wavelength (peak at 450 nm) and the capability for separately detecting the red and green components of the emission spectrum. The main outcome measure was the percentage of area occupied by green-emitting fluorophores in the macula. In addition, this measure was performed in separate regions providing a topographical assessment in the foveal, parafoveal and perifoveal regions. Furthermore, the level of agreement between repeated measurements was evaluated. Thirty eyes from 30 healthy volunteers were included in this analysis. Mean age was 26.2 ± 2.8 years (median: 25.0 years; range: 23.0–32.0 years). Median (interquartile range—IQR) area occupied by green-emitting fluorophores was 3.6% (1.9–4.7%) in the macular region. In the topographical analysis, this percentage was higher in the foveal area (median = 33.3%, IQR = 21.9–41.2%), as compared with both the parafoveal (median = 5.3%; IQR = 2.4–8.1%; p < 0.0001) and perifoveal (median = 0.5%, IQR = 0.2–0.8%; p < 0.0001) regions. The coefficient of variation (CV; ranging from 1.1% to 1.7% in the analyzed regions) and the intraclass correlation coefficient (ICC; ranging from 0.93 to 0.97) indicated high levels of repeatability. In conclusion, the assessment of green-emitting fluorophores is repeatable. The distribution of these fluorophores is highest in the foveal region. Assuming that flavin adenine dinucleotide (FAD) emits in the green autofluorescence spectrum, this variability could be secondary to an increased quantity of mitochondria in the foveal region.

scholarly journals Comparison of short-wavelength blue-light autofluorescence and conventional blue-light autofluorescence in geographic atrophy

2018 ◽  
Vol 103 (5) ◽  
pp. 610-616 ◽  
Author(s):  
Enrico Borrelli ◽  
Muneeswar Gupta Nittala ◽  
Nizar Saleh Abdelfattah ◽  
Jianqin Lei ◽  
Amir H Hariri ◽  
...  
Keyword(s):  
Blue Light ◽  
Imaging Modality ◽  
Fundus Autofluorescence ◽  
Intraclass Correlation ◽  
Geographic Atrophy ◽  
Area Measurement ◽  
Excitation Wavelength ◽  
Lesion Area ◽  
Significant Difference ◽  
The Individual

Background/aimsTo systematically compare the intermodality and inter-reader agreement for two blue-light confocal fundus autofluorescence (FAF) systems.MethodsThirty eyes (21 patients) with a diagnosis of geographic atrophy (GA) were enrolled. Eyes were imaged using two confocal blue-light FAF devices: (1) Spectralis device with a 488 nm excitation wavelength (488-FAF); (2) EIDON device with 450 nm excitation wavelength and the capability for ‘colour’ FAF imaging including both the individual red and green components of the emission spectrum. Furthermore, a third imaging modality (450-RF image) isolating and highlighting the red emission fluorescence component (REFC) was obtained and graded. Each image was graded by two readers to assess inter-reader variability and a single image for each modality was used to assess the intermodality variability.ResultsThe 95% coefficient of repeatability (1.35 mm2 for the 488-FAF-based grading, 8.13 mm2 for the 450-FAF-based grading and 1.08 mm2 for the 450-RF-based grading), the coefficient of variation (1.11 for 488-FAF, 2.05 for 450-FAF, 0.92 for 450-RF) and the intraclass correlation coefficient (0.994 for 488-FAF, 0.711 for 450-FAF, 0.997 for 450-RF) indicated that 450-FAF-based and 450-RF-based grading have the lowest and highest inter-reader agreements, respectively. The GA area was larger for 488-FAF images (median (IQR) 2.1 mm2 (0.8–6.4 mm2)) than for 450-FAF images (median (IQR) 1.0 mm2 (0.3–4.3 mm2); p<0.0001). There was no significant difference in lesion area measurement between 488-FAF-based and 450-RF-based grading (median (IQR) 2.6 mm2 (0.8–6.8 mm2); p=1.0).ConclusionThe isolation of the REFC from the 450-FAF images allowed for a reproducible quantification of GA. This assessment had good comparability with that obtained with 488-FAF images.

Test-Retest-Reliability of Computer-Based Metamorphopsia Measurement in Macular Diseases

2020 ◽  
Author(s):  
Daniela Claessens ◽  
Alexander K. Schuster ◽  
Ronald V. Krüger ◽  
Marian Liegl ◽  
Laila Singh ◽  
...  
Keyword(s):  
Macular Edema ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Measuring Method ◽  
Repeated Measurements ◽  
Retest Reliability ◽  
Macular Diseases ◽  
Computer Based ◽  
Test Retest Reliability

AbstractIn this study, the test-retest-reliability as one aspect of reliability of metamorphopsia measurements using a computer-based measuring method was determined in patients with macular diseases. Metamorphopsia amplitude, position, and area were quantified using AMD – A Metamorphopsia Detector software (app4eyes GmbH & Co. KG, Germany) in patients with diabetic, myopic, or uveitic macular edema, intermediate or neovascular age-associated macular degeneration, epiretinal membrane, vitelliform maculopathy, Irvine-Gass syndrome, or macular edema due to venous retinal occlusion. The intraclass correlation coefficient (ICC) was calculated in order to determine the repeatability of two repeated measurements and was used as an indicator of the reliability of the measurements. In this study, metamorphopsia measurements were conducted on 36 eyes with macular diseases. Metamorphopsia measurements made using AMD – A Metamorphopsia Detector software were highly reliable and repeatable in patients with maculopathies. The intraclass correlation coefficient of all indices was excellent (0.95 – 0.97). For diseases of the vitreoretinal interface or macular diseases with intra- or subretinal edema, this metamorphopsia measurement represents a supplement for visual function testing in the clinic, as well as in clinical studies.

scholarly journals Comparing Donor- and Acceptor-Originated Exciton Dynamics in Non-Fullerene Acceptor Blend Polymeric Systems

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1770
Author(s):  
Chan Im ◽  
Sang-Woong Kang ◽  
Jeong-Yoon Choi ◽  
Jongdeok An
Keyword(s):  
Flexible Electronics ◽  
Transient Absorption ◽  
Film Formation ◽  
Transient Absorption Spectroscopy ◽  
Excitation Wavelength ◽  
Polymeric Systems ◽  
Donor And Acceptor ◽  
Novel Material ◽  
Spectrally Resolved ◽  
Energy Strategies

Non-fullerene type acceptors (NFA) have gained attention owing to their spectral extension that enables efficient solar energy capturing. For instance, the solely NFA-mediated absorbing region contributes to the photovoltaic power conversion efficiency (PCE) as high as ~30%, in the case of the solar cells comprised of fluorinated materials, PBDB-T-2F and ITIC-4F. This implies that NFAs must be able to serve as electron donors, even though they are conventionally assigned as electron acceptors. Therefore, the pathways of NFA-originated excitons need to be explored by the spectrally resolved photovoltaic characters. Additionally, excitation wavelength dependent transient absorption spectroscopy (TAS) was performed to trace the nature of the NFA-originated excitons and polymeric donor-originated excitons separately. Unique origin-dependent decay behaviors of the blend system were found by successive comparing of those solutions and pristine films which showed a dramatic change upon film formation. With the obtained experimental results, including TAS, a possible model describing origin-dependent decay pathways was suggested in the framework of reaction kinetics. Finally, numerical simulations based on the suggested model were performed to verify the feasibility, achieving reasonable correlation with experimental observables. The results should provide deeper insights in to renewable energy strategies by using novel material classes that are compatible with flexible electronics.

Test–Retest Reliability of the Mini-BESTest in People With Mild to Moderate Multiple Sclerosis

2021 ◽  
Author(s):  
A Wallin ◽  
M Kierkegaard ◽  
E Franzén ◽  
S Johansson
Keyword(s):  
Multiple Sclerosis ◽  
Measurement Errors ◽  
Balance Control ◽  
Intraclass Correlation ◽  
Repeated Measurements ◽  
Minimal Detectable Change ◽  
Detectable Change ◽  
Limits Of Agreement ◽  
Retest Reliability ◽  
Test Retest Reliability

Abstract Objective The mini-BESTest is a balance measure for assessment of the underlying physiological systems for balance control in adults. Evaluations of test–retest reliability of the mini-BESTest in larger samples of people with multiple sclerosis (MS) are lacking. The purpose of this study was to investigate test–retest reliability of the mini-BESTest total and section sum scores and individual items in people with mild to moderate overall MS disability. Methods This study used a test–retest design in a movement laboratory setting. Fifty-four people with mild to moderate overall MS disability according to the Expanded Disability Status scale (EDSS) were included, with 28 in the mild subgroup (EDSS 2.0–3.5) and 26 in the moderate subgroup (EDSS 4.0–5.5). Test–retest reliability of the mini-BESTest was evaluated by repeated measurements taken 1 week apart. Reliability and measurement error were analyzed. Results Test–retest reliability for the total scores were considered good to excellent, with intraclass correlation coefficients of .88 for the whole sample, .83 for the mild MS subgroup, and .80 for the moderate MS subgroup. Measurement errors were small, with standard error of measurement and minimal detectable change of 1.3 and 3.5, respectively, in mild MS, and 1.7 and 4.7, respectively, in moderate MS. The limits of agreement were − 3.4 and 4.6. Test–retest reliability for the section scores were fair to good or excellent; weighted kappa values ranged from .62 to .83. All items but 1 showed fair to good or excellent test–retest reliability, and percentage agreement ranged from 61% to 100%. Conclusions The mini-BESTest demonstrated good to excellent test–retest reliability and small measurement errors and is recommended for use in people with mild to moderate MS. Impact Knowledge of limits of agreement and minimal detectable change contribute to interpretability of the mini-BESTest total score. The findings of this study enhance the clinical usefulness of the test for evaluation of balance control and for designing individually customized balance training with high precision and accuracy in people with MS.

A Relational Theory of Reputational Stability and Change

2021 ◽  
Author(s):  
Anastasiya Zavyalova ◽  
Jonathan Bundy ◽  
Stephen E. Humphrey
Keyword(s):  
Relational Theory ◽  
Organizational Studies ◽  
Stability And Change ◽  
Organizational Reputation ◽  
Central Elements ◽  
Path Dependent ◽  
The Stability ◽  
Indirect Information ◽  
Level Of Agreement ◽  
Do So

An ongoing discussion in organizational studies has focused on the path-dependent nature of organizational reputation. To date, however, there has been little explanation about when and why some constituents’ reputation judgments remain stable, whereas others are more prone to change. We contribute to this research by developing a relational theory of reputational stability and change. Our fundamental argument is that differences in constituent-organization relationships, as well as in the reputational communities that surround these relationships, affect the stability and change of reputation judgments. First, we highlight three relationship characteristics—favorability, history, and directness—and theorize that the reputation judgments of constituents with more unfavorable, longer, and more direct relationships with an organization are more stable, whereas the reputation judgments of constituents with more favorable, shorter, and more indirect relationships with the organization are less stable. We then develop the concept of reputational communities as a key source of indirect information about organizations. We highlight that the immediacy, size, and level of agreement within reputational communities affect how influential they are in changing individual constituents’ reputation judgments. Specifically, we propose that more immediate and larger reputational communities with a higher level of agreement are most likely to change individual constituents’ reputation judgments, whereas more distant and smaller reputational communities with a lower level of agreement are least likely to do so. Overall, we position constituents’ relationships with an organization and the communities that surround these relationships as central elements for understanding reputational stability and change.

scholarly journals Combining F-Scan and GAITRite® for use in Clinical Gait Analysis: A Validation Study.

2020 ◽  
Author(s):  
Stephanie Speight ◽  
Selina Reidy ◽  
John Stephenson ◽  
Sarah Reel
Keyword(s):  
Gait Analysis ◽  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Intraclass Correlation ◽  
Cost Effective ◽  
Quality Data ◽  
Concordance Correlation Coefficient ◽  
Concordance Correlation ◽  
Mean Values ◽  
Level Of Agreement

Abstract BackgroundClinical gait analysis is widely used to aid the assessment and diagnosis of symptomatic pathologies. Equipment based analysis provides clinicians with a more comprehensive assessment using pressure systems such as F-scan, or analysis of the spatial-temporal parameters of gait using GAITRite. There are systems however such as Strideway™ that can measure these parameters simultaneously, but can be expensive. This study aimed to determine whether standalone systems can be used collectively while still providing quality data, as a cost-effective alternative.MethodsTwenty-six participants walked on a standard floor and a GAITRite walkway, three times wearing the F-Scan system. Mid gait protocols were utilised by analysing the contact pressure of the 2 nd metatarsophalangeal joint of the third, fifth and seventh step from each walk. The Bland-Altman method was used to determine a level of agreement between the two surfaces, using mean values from all walks of all participants who successfully completed all required walks. The intraclass correlation coefficient and Lin’s concordance correlation coefficient were calculated as indices of reliability.ResultsThe intraclass correlation coefficient was calculated to be 0.991 and Lin’s concordance correlation coefficient for the data was calculated to be 0.956, indicating very good reproducibility.ConclusionsThe level of agreement in plantar pressures observed on the two surfaces was very high, suggesting that it is feasible to use F-Scan and GAITRite® together in a clinical setting, as an alternative to other less cost-effective standalone systems.

scholarly journals Engagement features judged by excessive drinkers as most important to include in smartphone applications for alcohol reduction: A mixed-methods study

2018 ◽  
Vol 4 ◽  
pp. 205520761878584 ◽  
Author(s):  
Olga Perski ◽  
Dario Baretta ◽  
Ann Blandford ◽  
Robert West ◽  
Susan Michie
Keyword(s):  
Focus Groups ◽  
Intraclass Correlation ◽  
Psychological Needs ◽  
Smartphone Applications ◽  
Focus Group Study ◽  
Online Study ◽  
Motivational Support ◽  
And Control ◽  
Alcohol Reduction ◽  
Level Of Agreement

Objective Engagement with smartphone applications (apps) for alcohol reduction is necessary for their effectiveness. This study explored (1) the features that are ranked as most important for engagement by excessive drinkers and (2) why particular features are judged to be more important for engagement than others. Methods Two studies were conducted in parallel. The first was a focus group study with adult excessive drinkers, interested in reducing alcohol consumption using an app ( ngroups = 3). Participants individually ranked their top 10 features from a pre-specified list and subsequently discussed their rankings. The second was an online study with a new sample ( n = 132). Rankings were analysed using the intraclass correlation coefficient (ICC) to assess the level of agreement between raters for each study. Qualitative data were analysed using inductive thematic analysis. Results There was low agreement between participants in their rankings, both in the focus groups (ICC = 0.15, 95% confidence interval (CI) = 0.03–0.38) and the online sample (ICC = 0.11, 95% CI = 0.06–0.23). ‘Personalisation’, ‘control features’ and ‘interactive features’ were most highly ranked in the focus groups. These were expected to elicit a sense of benefit and usefulness, adaptability, provide motivational support or spark users’ interest. Results from the online study partly corroborated these findings. Conclusion There was little agreement between participants, but on average, the features judged to be most important for inclusion in smartphone apps for alcohol reduction were personalisation, interactive features and control features. Tailoring on users’ underlying psychological needs may promote engagement with alcohol reduction apps.

scholarly journals Reliability of Physiological Responses Induced by Basic Emotions: A Pilot Study

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Eun-Hye Jang ◽  
Sangwon Byun ◽  
Mi-Sook Park ◽  
Jin-Hun Sohn
Keyword(s):  
Internal Consistency ◽  
Interrater Reliability ◽  
Physiological Responses ◽  
Skin Conductance Level ◽  
Intraclass Correlation ◽  
Repeated Measurements ◽  
Physiological Signals ◽  
Basic Emotions ◽  
Reliability Indices ◽  
Film Clips

Abstract Background Although emotion-specific autonomic responses based on the discrete theory of emotion have been widely studied, studies on the reliability of physiological responses to emotional stimuli are limited. In this study, we aimed to assess the reliability of physiological changes induced by the six basic emotions (happiness, sadness, anger, fear, disgust, and surprise) that were measured during 10 weekly repeated experiments. Methods Twelve college students participated, and in each experiment, physiological signals were collected before and while participants were watching emotion-provoking film clips. Additionally, the participants self-evaluated the emotions that they experienced during the film presentation at the end of each emotional stimulus. To avoid adaptation of participants to identical stimuli during repeated measurements, we used 10 different film clips for each emotion, and thus a total of 60 film clips over 10 weeks were used. Physiological features, such as skin conductance level (SCL), fingertip temperature (FT), heart rate (HR), and blood volume pulse (BVP), were extracted from the physiological signals. Two reliability indices, Cronbach’s alpha and intraclass correlation coefficient, were calculated from the physiological features to assess internal consistency and interrater reliability, respectively. Results We found that SCL, HR, and BVP measured during the emotion-provoking phase over the 10 weekly sessions were more reliable than those assessed at baseline. Furthermore, SCL, HR, and BVP from the emotion-provoking phase exhibited excellent internal consistency and interrater reliability. Conclusions Our findings suggest that these features can be used as reliable physiological indices in emotion studies. The results also support the significance of physiological signals as meaningful indicators for emotion recognition in HCI (human computer interface) area.

Reproducibility of Toe Pressure Measurements

2009 ◽  
Vol 33 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Neil Cloete ◽  
Clare Kiely ◽  
Mary Paula Colgan ◽  
Naseem Haider ◽  
Sean O'Neill ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Carotid Artery Disease ◽  
Intraclass Correlation ◽  
Repeated Measurements ◽  
Pressure Measurements ◽  
Repeatability Coefficient ◽  
Significant Difference ◽  
Artery Disease ◽  
Toe Pressure

Introduction Ankle/brachial indices are inaccurate in the presence of calcification, and physicians may rely on the measurement of digital pressures. As the population continues to age and with the escalation in type 2 diabetes, the importance of, and reliance on, toe pressure measurements will increase. The aim of this study was to assess the reproducibility of toe pressure measurements in a single vascular laboratory. Methods Repeated ankle/brachial indices and toe pressures were measured in 20 patients (10 with known peripheral vascular disease and 10 with aneurysmal or carotid artery disease but no history of PVD), and 10 control patients. Three measurements were made 48 hours apart. All measurements were made by a single vascular technologist. Reproducibility was assessed by the use of the repeatability coefficient and the intraclass correlation coefficient. Results Ankle/brachial indices ranged from 0.36 to 2.4, toe pressures from 18 mmHg to 173 mmHg, and toe/brachial indices from 0.11 to 1.1. The repeatability coefficient showed no significant difference between measurements ( p > 0.1) and the intraclass correlation coefficient estimates showed high agreement between repeated measurements (0.77–0.99). Bland-Altman plots indicated that the observer variability was equally distributed across the range of pressure measurements. Conclusion These results confirm the intraobserver reproducibility of toe pressure measurements; however, further work is required to demonstrate inter-observer reproducibility.

scholarly journals Reproducibility and Validity of the 10-Meter Shuttle Ride Test in Wheelchair-Using Children and Adolescents With Cerebral Palsy

2013 ◽  
Vol 93 (7) ◽  
pp. 967-974 ◽  
Author(s):  
Olaf Verschuren ◽  
Maremka Zwinkels ◽  
Marjolijn Ketelaar ◽  
Femke Reijnders-van Son ◽  
Tim Takken
Keyword(s):  
Cerebral Palsy ◽  
Cardiorespiratory Fitness ◽  
Gold Standard ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Peak Oxygen Uptake ◽  
Repeated Measurements ◽  
Manual Wheelchair ◽  
Intraclass Correlation Coefficients

BackgroundFor children with cerebral palsy (CP) who are able to walk or run, the 10-m shuttle run test is currently the test of choice to assess cardiorespiratory fitness. This test, however, has not yet been examined in wheelchair-using youth with CP.ObjectiveThe purpose of this study was to investigate the test-retest reproducibility and validity of the 10-m shuttle ride test (SRiT) in youth with CP.DesignRepeated measurements of the SRiT were obtained.MethodsTwenty-three individuals with spastic CP (18 boys, 5 girls; mean age=13.3 years, SD=3.6 years) using a manual wheelchair for at least part of the day participated in this study. During the study, all participants performed one graded arm exercise test (GAET) and 2 identical SRiTs within 2 weeks. Peak oxygen uptake (V̇o2peak), peak heart rate (HRpeak), and respiratory exchange ratio (RER) were recorded. Intraclass correlation coefficients (2,1), the smallest detectable difference, and the limits of agreement (LOA) were calculated. The association between the results of the SRiT and GAET was tested using Pearson correlation coefficients.ResultsIntraclass correlation coefficients (.99, 95% confidence interval=.98–1.00) for all variables indicated highly acceptable reproducibility. The LOA analysis revealed satisfactory levels of agreement. The SRiT variables demonstrated strong, significant positive correlations for V̇o2peak values obtained during the SRiT and the GAET (r=.84, P&lt;.01).LimitationsAlthough the GAET is considered the gold standard, the cardiorespiratory demand during the GAET was significantly lower compared with during the SRiT. Future studies should determine whether the GAET can still be accepted as the gold standard for upper-extremity exercise.ConclusionsThe SRiT is a reproducible and valid test for measuring cardiorespiratory fitness in youth with spastic CP who self-propel a manual wheelchair.

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