3 research outputs found

    Occurrence of seizures in hospitalized patients with a pre-existing seizure disorder

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    Objective. To assess the frequency of seizures in hospitalized patients with a pre-existing seizure disorder. Patients and Methods. A retrospective review was conducted on all patients with a documented seizure disorder who were hospitalized between January 1, 2002 and December 31, 2007. Children aged < 2 years and hospital admission for seizure control or surgical or obstetric indications were excluded. The first hospital admission of at least 24 hours was identified for each patient. Patient demographics, details of the seizure disorder, details of the hospital admission, and clinically-apparent seizure activity documented during the inpatient stay were recorded from the medical record. Results. During the 6-year study period, 720 patients with a documented seizure disorder were admitted for at least 24 hours. Thirty-nine patients experienced seizure activity for an overall frequency of 5.4% (95% CI: 3.8-7.1%). Younger age (p = 0.001), greater frequency of baseline seizure activity (p < 0.001), recent seizure activity (p < 0.001), greater number of chronic antiepileptic medications (p = 0.01), and admission for neurological (p = 0.03) conditions were associated with increased frequency of seizure activity during hospitalization. Conclusions. The majority of seizures occurring in hospitalized patients with a pre-existing seizure disorder appear related to the patient’s underlying seizure disorder. Because patients with frequent seizures on numerous anti-epileptic medications are likely to experience a seizure while hospitalized, it is essential to be prepared to treat seizure activity regardless of the reason for admission

    ON-SKY PERFORMANCE ANALYSIS OF THE VECTOR APODIZING PHASE PLATE CORONAGRAPH ON MagAO/Clio2

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    We report on the performance of a vector apodizing phase plate coronagraph that operates over a wavelength range of 2-5 mu m. and is installed in MagAO/Clio2 at the 6.5 m Magellan Clay telescope at Las Campanas Observatory, Chile. The coronagraph manipulates the phase in the pupil to produce three beams yielding two coronagraphic point-spread functions (PSFs) and one faint leakage PSF. The phase pattern is imposed through the inherently achromatic geometric phase, enabled by liquid crystal technology and polarization techniques. The coronagraphic optic is manufactured using a direct-write technique for precise control of the liquid crystal pattern. and multitwist retarders for achromatization. By integrating a linear phase ramp to the coronagraphic phase pattern, two separated coronagraphic PSFs are created with a single pupil-plane optic, which makes it robust and easy to install in existing telescopes. The two coronagraphic PSFs contain a 180 degrees dark hole on each side of a star, and these complementary copies of the star are used to correct the seeing halo close to the star. To characterize the coronagraph, we collected a data set of a bright (m(L) = 0-1) nearby star with similar to 1.5 hr of observing time. By rotating and optimally scaling one PSF. and subtracting it from the other PSF, we see a contrast improvement by 1.46 magnitudes at 3.5 lambda/D. With regular angular differential imaging at 3.9 mu m, the MagAO vector apodizing phase plate coronagraph delivers a 5 sigma Delta mag contrast of 8.3 (= 10(-3.3)) at 2 lambda/D and 12.2 (= 10(-4.8)) at 3.5 lambda/D.Netherlands Organization for Scientific Research (NWO); European Research Council [678194]; NASA Exoplanets Research Program (XRP) [NNX16AD44G]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    ON-SKY PERFORMANCE ANALYSIS OF THE VECTOR APODIZING PHASE PLATE CORONAGRAPH ON MagAO/Clio2

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    We report on the performance of a vector apodizing phase plate coronagraph that operates over a wavelength range of 25μ2-5 \mum and is installed in MagAO/Clio2 at the 6.5 m Magellan Clay telescope at Las Campanas Observatory, Chile. The coronagraph manipulates the phase in the pupil to produce three beams yielding two coronagraphic point-spread functions (PSFs) and one faint leakage PSF. The phase pattern is imposed through the inherently achromatic geometric phase, enabled by liquid crystal technology and polarization techniques. The coronagraphic optic is manufactured using a direct-write technique for precise control of the liquid crystal pattern, and multitwist retarders for achromatization. By integrating a linear phase ramp to the coronagraphic phase pattern, two separated coronagraphic PSFs are created with a single pupil-plane optic, which makes it robust and easy to install in existing telescopes. The two coronagraphic PSFs contain a 180^\circ dark hole on each side of a star, and these complementary copies of the star are used to correct the seeing halo close to the star. To characterize the coronagraph, we collected a dataset of a bright (mL=01m_L=0-1) nearby star with \sim1.5 hr of observing time. By rotating and optimally scaling one PSF and subtracting it from the other PSF, we see a contrast improvement by 1.46 magnitudes at 3.5λ/D3.5 \lambda/D. With regular angular differential imaging at 3.9 μ\mum, the MagAO vector apodizing phase plate coronagraph delivers a 5σ Δ5\sigma\ \Delta mag contrast of 8.3 (=103.3=10^{-3.3}) at 2 λ/D\lambda/D and 12.2 (=104.8=10^{-4.8}) at 3.5λ/D3.5 \lambda/D.Comment: Published in ApJ. 8 figures, 1 table. Received 2016 June 17; revised 2016 November 3; accepted 2016 November 28; published 2017 January 1
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