413 research outputs found

    Nonmydriatic Fundus Photography: A Practical Review for the Neurologist

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    Declining proficiency in direct ophthalmoscopy by non-ophthalmologists has spurred a search for alternative methods of ocular fundus examination. Recent technological advances have improved the ease of use and quality of non-mydriatic fundus photography, increasing its suitability for clinical care. As the availability of this technology continues to improve, neurologists will need to be familiar with its advantages, limitations and potential applications in the clinical care of patients with neurological conditions

    Physical Activity and Quality of Life in Retinitis Pigmentosa

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    Purpose. Aerobic exercise has been found to be neuroprotective in animal models of retinal degeneration. This study aims to report physical activity levels in patients with RP and investigate the relationship between physical activity and vision-related quality-of-life (QOL). Materials and Methods. A retrospective study of adult patients with RP examined in 2005–2014. Physical activity levels were assessed using the Godin Exercise Questionnaire. The NEI-Visual Function Questionaire-25 (VFQ-25), SF-36 General Health survey, and Pepper Assessment Tool for Disability (PAT-D) were administered. Results. 143 patients participated. 81 (56.6%) patients were classified as “active” and 62 (43.4%) as “insufficiently active” by Godin score. VFQ-25 revealed statistically significant differences between the active and insufficiently active patients, including overall visual function (53.3 versus 45.1, p=0.010), color vision (73.8 versus 52.9, p<0.001), and peripheral vision (34.3 versus 23.8, p=0.021). The physical component of the SF-36 and the PAT-D survey also demonstrated statistically significant differences (47.2 versus 52.9, p=0.002; 24.3 versus 30.0, p=0.010). Active patients had a higher initial Goldmann visual field (GVF) score (74.8 versus 60.1 degrees, p=0.255) and final GVF score (78.7 versus 47.1 degrees, p=0.069) but did not reach statistical significance. Conclusions. In RP, increased physical activity is associated with greater self-reported visual function and QOL

    Referral Patterns in Neuro-Ophthalmology

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    Background: Neuro-ophthalmologists specialize in complex, urgent, vision- and life-threatening problems, diagnostic dilemmas, and management of complex work-ups. Access is currently limited by the relatively small number of neuro-ophthalmologists, and consequently, patients may be affected by incorrect or delayed diagnosis. The objective of this study is to analyze referral patterns to neuro-ophthalmologists, characterize rates of misdiagnoses and delayed diagnoses in patients ultimately referred, and delineate outcomes after neuro-ophthalmologic evaluation. Methods: Retrospective chart review of 300 new patients seen over 45 randomly chosen days between June 2011 and June 2015 in one tertiary care neuro-ophthalmology clinic. Demographics, distance traveled, time between onset and neuro-ophthalmology consultation (NOC), time between appointment request and NOC, number and types of providers seen before referral, unnecessary tests before referral, referral diagnoses, final diagnoses, and impact of the NOC on outcome were collected. Results: Patients traveled a median of 36.5 miles (interquartile range [IQR]: 20–85). Median time from symptom onset was 210 days (IQR: 70–1,100). Median time from referral to NOC was 34 days (IQR: 7–86), with peaks at one week (urgent requests) and 13 weeks (routine requests). Median number of previous providers seen was 2 (IQR: 2–4; range:0–10), and 102 patients (34%) had seen multiple providers within the same specialty before referral. Patients were most commonly referred for NOC by ophthalmologists (41% of referrals). Eighty-one percent (242/300) of referrals to neuro-ophthalmology were appropriate referrals. Of the 300 patients referred, 247 (82%) were complex or very complex; 119 (40%) were misdiagnosed; 147 (49%) were at least partially misdiagnosed; and 22 (7%) had unknown diagnoses. Women were more likely to be at least partially misdiagnosed—108 of 188 (57%) vs 39 of 112 (35%) of men (P < 0.001). Mismanagement or delay in care occurred in 85 (28%), unnecessary tests in 56 (19%), unnecessary consultations in 64 (22%), and imaging misinterpretation in 16 (5%). Neuro-ophthalmologists played a major role in directing treatment, such as preserving vision, preventing life-threatening complications, or avoiding harmful treatment in 62 (21%) patients. Conclusions: Most referrals to neuro-ophthalmologists are appropriate, but many are delayed. Misdiagnosis before referral is common. Neuro-ophthalmologists often prevent vision- and life-threatening complications

    Bullets over ballots: Islamist groups, the state and electoral violence in Egypt and Morocco

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    This article is concerned with state-sponsored electoral violence in liberalized autocracies. The first section of the paper identifies a number of variables that can help explain the decision calculus of authoritarian incumbents to deploy force against strong electoral challengers. The second section then examines these propositions with reference to Egypt and Morocco. Drawing on recent parliamentary elections in both countries the article questions why, despite facing the challenge of political Islam, the two regimes differed so markedly in their willingness to manipulate the polls by recourse to violence. Whilst the Egyptian authorities decided to abrogate all pretence of peaceful elections in favour of violent repression against the Muslim Brotherhood candidates and sympathizers, no such tactics were deployed by the ruling elite in Morocco. We suggest that three principal factors influenced the regimes' response to this electoral challenge: (1) the centrality of the elected institution to authoritarian survival; (2) the availability of alternative electioneering tools; and (3) the anticipated response of the international community. The article concludes by suggesting that in order to understand better when and how states deploy violence in elections, we need to focus on a more complex set of factors rather than simply on the electoral potency of key opposition challengers or the authoritarian nature of the state

    Comparison of inclusive and photon-tagged jet suppression in 5.02 TeV Pb+Pb collisions with ATLAS

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    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH &lt; 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 &lt; κλ &lt; 6.9 and −0.5 &lt; κ2V &lt; 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

    Measurement of the H → γ γ and H → ZZ∗ → 4 cross-sections in pp collisions at √s = 13.6 TeV with the ATLAS detector

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    The inclusive Higgs boson production cross section is measured in the di-photon and the Z Z∗ → 4 decay channels using 31.4 and 29.0 fb−1 of pp collision data respectively, collected with the ATLAS detector at a centre of-mass energy of √s = 13.6 TeV. To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the chan nel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are σfid,γ γ = 76+14 −13 fb, and σfid,4 = 2.80 ± 0.74 fb, in agreement with the corresponding Standard Model predic tions of 67.6±3.7 fb and 3.67±0.19 fb. Assuming Standard Model acceptances and branching fractions for the two chan nels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of σ (pp → H) = 67+12 −11 pb and 46±12 pb at 13.6 TeV from the di-photon and Z Z∗ → 4 measurements respectively. The two measure ments are combined into a total cross-section measurement of σ (pp → H) = 58.2±8.7 pb, to be compared with the Stan dard Model prediction of σ (pp → H)SM = 59.9 ± 2.6 p

    Search for pairs of muons with small displacements in pp collisions at root s=13 TeV with the ATLAS detector

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    A search for new phenomena giving rise to pairs of opposite electrically charged muons with impact parameters in the millimeter range is presented, using 139 fb−1 of √s = 13 TeV pp collision data from the ATLAS detector at the LHC. The search targets the gap in coverage between existing searches targeting final states with leptons with large displacement and prompt leptons. No significant excess over the background expectation is observed and exclusion limits are set on the mass of long-lived scalar supersymmetric muon-partners (smuons) with much lower lifetimes than previously targeted by displaced muon searches. Smuon lifetimes down to 1 ps are excluded for a smuon mass of 100 GeV, and smuon masses up to 520 GeV are excluded for a proper lifetime of 10 ps, at 95% confidence level. Finally, model-independent limits are set on the contribution from new phenomena to the signal-region yield

    Comparison of inclusive and photon-tagged jet suppression in 5.02 TeV Pb+Pb collisions with ATLAS

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    Parton energy loss in the quark–gluon plasma (QGP) is studied with a measurement of photon-tagged jet production in 1.7 nb−1 of Pb+Pb data and 260 pb−1 of pp data, both at √sNN = 5.02 TeV, with the ATLAS detector. The process pp → γ +jet+X and its analogue in Pb+Pb collisions is measured in events containing an isolated photon with transverse momentum (pT) above 50 GeV and reported as a function of jet pT. This selection results in a sample of jets with a steeply falling pT distribution that are mostly initiated by the showering of quarks. The pp and Pb+Pb measurements are used to report the nuclear modification factor, RAA, and the fractional energy loss, Sloss, for photon-tagged jets. In addition, the results are compared with the analogous ones for inclusive jets, which have a significantly smaller quark-initiated fraction. The RAA and Sloss values are found to be significantly different between those for photon-tagged jets and inclusive jets, demonstrating that energy loss in the QGP is sensitive to the colour-charge of the initiating parton. The results are also compared with a variety of theoretical models of colour-charge-dependent energy loss

    Measurement of the cross-sections of the electroweak and total production of a Zγ pair in association with two jets in pp collisions at root s=13 TeV with the ATLAS detector

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