670 research outputs found

    Observation of cone and rod photoreceptors in normal subjects and patients using a new generation adaptive optics scanning laser ophthalmoscope.

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    We demonstrate the capability of a new generation adaptive optics scanning laser ophthalmoscope (AOSLO) to resolve cones and rods in normal subjects, and confirm our findings by comparing cone and rod spacing with published histology measurements. Cone and rod spacing measurements are also performed on AOSLO images from two different diseased eyes, one affected by achromatopsia and the other by acute zonal occult outer retinopathy (AZOOR). The potential of AOSLO technology in the study of these and other retinal diseases is illustrated

    Lessons Learned in Qatar: The Role of the Netherlands and Its Businesses in Addressing Human Rights Abuses in Mega-Sporting Events

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    Mega-sporting events (MSEs) can have a negative impact on human rights throughout their lifecycle, from the bidding stage, over to the planning and preparation stage, the delivery of the event, and also as part of their legacy after the event has concluded. They can be linked to land grabbing, forced evictions, forced labour and many other human rights abuses. The problem is that only a very few of these cases are actually addressed in the sense that rights-holders receive an effective remedy and those responsible for the abuse are held to account. MSEs are jointly organized and staged by public, private, national, and international actors, which each contribute in different ways to the associated human rights impact. Rather than looking at the responsibility of those actors directly involved in organizing and staging the event, this article looks at the responsibility of the participating actors of states that are represented at the event, namely businesses and sports bodies, using the Netherlands and the 2022 FIFA World Cup in Qatar as the guiding example. The central questions it tries to explore based on lessons learned and opportunities missed in Qatar are how such actors are connected to adverse human rights impacts associated with MSEs, which responsibilities under the human rights framework flow from those connections, and how participating states should then ensure that businesses live up to their responsibilities

    Superstitious behavior and ritualistic practices among former athletes

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    Superstitious and ritualistic behaviors in sport have been well documented (Brevers, Dan, Noel, & Nils, 2011a, 2011b; Buhrmann & Zaugg, 1983 Foster, Weigand, & Baines, 2006). Studies have identified several benefits athletes gain from these practices such as: reduction of sport anxiety (Jackson, Ashford, & Norsworthy, 2006), and reaching peak performance (Krane & Williams, 2010). Other research has studied the effects that personality antecedents, such as locus of control (LOC) and Athletic Identity (AI), might have on these practices (Griffith & Johnson, 2002). To date however, there has been little to no research done on whether former athletes would continue ritualistic or superstitious practices once out of organized sport. Accordingly, the present study evaluated the relationship between athletic career ritual/superstition (ACR/S) and post-athletic career ritual/ superstition (PACR/S); in addition to looking for any moderating variables using an adaptation of the Athletic Identity Measurement Scale (Brewer, van Raalte, & Linder, 1993), an adaptation of the Exhausted Eligibility Transition Scale (Moreland-Bishop, 2009), and the Religion Subscale from the Personal Life Values Questionnaire (Hyde & Weathington, 2006). Analysis of the data showed a positive correlation between ACR/S and PACR/S . Perceived success in sport was shown to moderate the relationship between ACR/S and PACR/S , while Athletic Identity, transition out of sport and religious importance had no significant effect on the relationship

    Principalā€“teacher relationships:Dimensionality and measurement invariance of a measure for primary and secondary school teachers

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    This study explored the dimensionality and measurement invariance of a multidimensional measure for evaluating teachersā€™ perceptions of the quality of their relationships with principals at the dyadic level. Participants were 630 teachers (85.9% female) from 220 primary and 204 secondary schools across the Netherlands. Teachers completed the 10-item Principalā€“Teacher Relationship Scale (PTRS) for their principals. Confirmatory factor analyses (CFA) provided evidence for a two-factor model, including a relational Closeness and Conflict dimension. Additionally, multigroup CFA results indicated strong invariance of the PTRS across school type, teacher gender, and teaching experience. Last, secondary school teachers and highly experienced teachers reported lower levels of Closeness and higher levels of Conflict in the relationship with their principal compared to primary school teachers and colleagues with less experience. Accordingly, the PTRS can be considered a valid and reliable measure that adds to the methodological repertoire of educational leadership research by focusing on both positive and negative aspects of dyadic principalā€“teacher relationships

    Dysflective cones: Visual function and cone reflectivity in long-term follow-up of acute bilateral foveolitis.

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    PURPOSE:Confocal adaptive optics scanning laser ophthalmoscope (AOSLO) images provide a sensitive measure of cone structure. However, the relationship between structural findings of diminished cone reflectivity and visual function is unclear. We used fundus-referenced testing to evaluate visual function in regions of apparent cone loss identified using confocal AOSLO images. METHODS:A patient diagnosed with acute bilateral foveolitis had spectral-domain optical coherence tomography (SD-OCT) (Spectralis HRA + OCT system [Heidelberg Engineering, Vista, CA, USA]) images indicating focal loss of the inner segment-outer segment junction band with an intact, but hyper-reflective, external limiting membrane. Five years after symptom onset, visual acuity had improved from 20/80 to 20/25, but the retinal appearance remained unchanged compared to 3 months after symptoms began. We performed structural assessments using SD-OCT, directional OCT (non-standard use of a prototype on loan from Carl Zeiss Meditec) and AOSLO (custom-built system). We also administered fundus-referenced functional tests in the region of apparent cone loss, including analysis of preferred retinal locus (PRL), AOSLO acuity, and microperimetry with tracking SLO (TSLO) (prototype system). To determine AOSLO-corrected visual acuity, the scanning laser was modulated with a tumbling E consistent with 20/30 visual acuity. Visual sensitivity was assessed in and around the lesion using TSLO microperimetry. Complete eye examination, including standard measures of best-corrected visual acuity, visual field tests, color fundus photos, and fundus auto-fluorescence were also performed. RESULTS:Despite a lack of visible cone profiles in the foveal lesion, fundus-referenced vision testing demonstrated visual function within the lesion consistent with cone function. The PRL was within the lesion of apparent cone loss at the fovea. AOSLO visual acuity tests were abnormal, but measurable: for trials in which the stimulus remained completely within the lesion, the subject got 48% correct, compared to 78% correct when the stimulus was outside the lesion. TSLO microperimetry revealed reduced, but detectible, sensitivity thresholds within the lesion. CONCLUSIONS AND IMPORTANCE:Fundus-referenced visual testing proved useful to identify functional cones despite apparent photoreceptor loss identified using AOSLO and SD-OCT. While AOSLO and SD-OCT appear to be sensitive for the detection of abnormal or absent photoreceptors, changes in photoreceptors that are identified with these imaging tools do not correlate completely with visual function in every patient. Fundus-referenced vision testing is a useful tool to indicate the presence of cones that may be amenable to recovery or response to experimental therapies despite not being visible on confocal AOSLO or SD-OCT images
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