36 research outputs found

    Pathfinder first light: alignment, calibration, and commissioning of the LINC-NIRVANA ground-layer adaptive optics subsystem

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    We present descriptions of the alignment and calibration tests of the Pathfinder, which achieved first light during our 2013 commissioning campaign at the LBT. The full LINC-NIRVANA instrument is a Fizeau interferometric imager with fringe tracking and 2-layer natural guide star multi-conjugate adaptive optics (MCAO) systems on each eye of the LBT. The MCAO correction for each side is achieved using a ground layer wavefront sensor that drives the LBT adaptive secondary mirror and a mid-high layer wavefront sensor that drives a Xinetics 349 actuator DM conjugated to an altitude of 7.1 km. When the LINC-NIRVANA MCAO system is commissioned, it will be one of only two such systems on an 8-meter telescope and the only such system in the northern hemisphere. In order to mitigate risk, we take a modular approach to commissioning by decoupling and testing the LINC-NIRVANA subsystems individually. The Pathfinder is the ground-layer wavefront sensor for the DX eye of the LBT. It uses 12 pyramid wavefront sensors to optically co-add light from natural guide stars in order to make four pupil images that sense ground layer turbulence. Pathfinder is now the first LINC-NIRVANA subsystem to be fully integrated with the telescope and commissioned on sky. Our 2013 commissioning campaign consisted of 7 runs at the LBT with the tasks of assembly, integration and communication with the LBT telescope control system, alignment to the telescope optical axis, off-sky closed loop AO calibration, and finally closed loop on-sky AO. We present the programmatics of this campaign, along with the novel designs of our alignment scheme and our off-sky calibration test, which lead to the Pathfinder's first on-sky closed loop images

    ToSkORL: Selbst- und Fremdeinschätzung bei der Untersuchung des Kopf-Hals-Bereichs

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    BACKGROUND A~central goal of medical school is acquisition of theoretical and practical competences. However, evidence on how capacity acquisition can be measured for special examination techniques is scarce. ToSkORL (Teaching of Skills in Otorhinolaryngology) is a project aimed at scientifically and didactically investigating students' self-evaluation skills in otorhinolaryngologic and head and neck examination techniques. METHODS During the examination techniques course, a~standardized oral and practical exam for nine different techniques was conducted. Using Likert scales, self-evaluation was based on questionnaires before the clinical skills exam and objective evaluation was performed by the examiners during the examination using a checklist. Self- and objective evaluation were correlated. Nine different examination skills were assessed 42~times each by a~total of 91~students. RESULTS Self-evaluation of competence in the different examination skills varied widely. Nevertheless, self- and objective evaluation correlated well overall, independent of age and gender. Students highly interested in otorhinolaryngology rated their own skills higher but tended toward overestimation. For examination items with intermediate difficulty, the highest divergences between self- and objective evaluation were found. CONCLUSION Student self-evaluations are an appropriate instrument for measuring competences in otorhinolaryngologic examinations. Instructors should focus on items with allegedly intermediate difficulty, which are most often over- and underestimated. ZUSAMMENFASSUNG HINTERGRUND: Ein zentrales Ziel des Medizinstudiums ist der Erwerb theoretischer und praktischer Kompetenzen. Es mangelt jedoch an Evidenz, wie der Erwerb von Kompetenzen in speziellen Untersuchungstechniken gemessen werden kann. ToSkORL (Teaching of Skills in Otorhinolaryngology) ist ein Projekt, das die studentische Selbstwahrnehmung ihrer Kompetenz bei speziellen Untersuchungstechniken der Hals-Nasen-Ohren-Heilkunde und des Kopf-Hals-Bereichs aus didaktisch-wissenschaftlicher Sichtweise beleuchtet. METHODIK Im Rahmen des Untersuchungskurses erfolgte eine standardisierte mündlich-praktische Prüfung zu neun verschiedenen Untersuchungstechniken. Vor der Prüfung erfolgte eine Evaluation der studentischen Selbsteinschätzung mittels Fragebogen, die Prüfung wurde mittels Checkliste durch die Prüfenden standardisiert geprüft. Selbst- und Fremdeinschätzung nach der Likert-Skala wurden korreliert. Die neun Untersuchungstechniken wurden jeweils 42-mal von insgesamt 91~Studierenden in gegenseitiger Untersuchung durchgeführt. ERGEBNISSE Die Selbsteinschätzung der Kompetenz in den Untersuchungstechniken variiert erheblich, insgesamt schätzten Studierende ihre eigene Untersuchungskompetenz weitgehend unabhängig von Alter und Geschlecht meist realistisch ein. Studierende mit einem hohen Interesse an der Hals-Nasen-Ohren-Heilkunde gaben bessere Selbsteinschätzungen an, neigten jedoch auch eher zur Selbstüberschätzung. Bei Untersuchungen des mittleren Schwierigkeitsniveaus ergab sich die größte Divergenz von Selbst- und Fremdeinschätzung. SCHLUSSFOLGERUNG Die studentische Selbsteinschätzung ist ein geeignetes Instrument zur Messung der Untersuchungskompetenz in der Hals-Nasen-Ohren-Heilkunde. Es sollte ein besonderer Fokus auf die Lehre vermeintlich mittelschwerer Untersuchungstechniken gelegt werden, da diese am stärksten über- und unterschätzt werden

    Operation of a layer-oriented multiconjugate adaptive optics system in the partial illumination regime

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    Multiconjugate adaptive optics (MCAO) promises uniform wide-field atmospheric correction. However, partial illumination of the layers at which the deformable mirrors are conjugated results in incomplete information about the full turbulence field. We report on a working solution to this difficulty for layer-oriented MCAO, including laboratory and on-sky demonstration with the LINC-NIRVANA instrument at the Large Binocular Telescope. This approach has proven to be simple and stable

    The calibration procedure of the LINC-NIRVANA ground and high layer WFS

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    LINC--NIRVANA (LN) is an MCAO module currently mounted on the Rear Bent Gregorian focus of the Large Binocular Telescope (LBT). It mounts a camera originally designed to realize the interferometric imaging focal station of the telescopes. LN follows the LBT binocular strategy having two twin channels: a double Layer Oriented Multi-Conjugate Adaptive Optics system assisting the two arms, supplies high order wave-front correction. In order to counterbalance the field rotation, a mechanical derotation is applied for the two ground wave-front sensors, and an optical (K-mirror) one for the two high layers sensors, fixing the positions of the focal planes with respect to the pyramids aboard the wavefront sensors. The derotation introduces a pupil images rotation on the wavefront sensors, changing the projection of the deformable mirrors on the sensor consequently.Comment: 9 pages, 6 figures, proceeding of the SPIE Astronomical Telescopes + Instrumentation meeting, Conference Adaptive Optics Systems VI held in Austin Convention Center, Austin, Texas, United States, 10 - 15 June 201

    LINC-NIRVANA Commissioning at the Large Binocular Telescope - Lessons Learned

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    LINC-NIRVANA (LN) is one of the instruments on-board the Large Binocular Telescope (LBT). LN is a high- resolution, near-infrared imager equipped with an advanced adaptive optics module. LN implements layer- oriented Multi-Conjugate Adaptive Optics (MCAO) approach using two independent wavefront sensors per side of the binocular telescope measuring the turbulence volume above the telescope. The capability of acquiring up to 20 Natural Guide Stars simultaneously from two distinct fields of view, and using them for wavefront sensing with 20 separate pyramids per side of the telescope makes the LN MCAO system one of a kind. Commissioning of the left MCAO channel is almost complete, while that of the right arm is on-going. The Science Verification on the left side is expected to start soon after the MCAO performance is optimised for faint guide stars. In this article, we put together the lessons learned during the commissioning of the LN MCAO module. We hope and believe that this article will help the future MCAO instrument commissioning teams

    Design and implementation of a service-oriented driver architecture for LINC-NIRVANA

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    LINC-NIRVANA (LN) is a German-Italian Fizeau (imaging) interferometer for the Large Binocular Telescope (LBT). The Instrument Control Software (ICS) of this instrument is a hierarchical, distributed software package, which runs on several computers. In this paper we present the bottom layer of the hierarchy - the Basic Device Application (BASDA) layer. This layer simplifies the development of the ICS through a general driver architecture, which supports different types of hardware. This generic device architecture provides a high level interface to encapsulate the hardware dependent driver. The benefit of such a device architecture is to keep the basic device-driver layer flexible and independent from the hardware, and to keep the hardware transparent to the ICS. Additionally, the basic device-driver layer supports interfaces to IDL based applications for calibration and laboratory testing of astronomical instruments, and interfaces to engineering GUIs that allow to maintain the software components easily

    Misjudgment of Skills in Clinical Examination Increases in Medical Students Due to a Shift to Exclusively Online Studies during the COVID-19 Pandemic

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    In medical school, practical capacity building is a central goal. During the COVID-19 pandemic, a shift to online teaching methods in university was mandated in many countries to reduce risk of SARS-CoV-2 transmission. This severely affected the teaching of psychomotor ability skills such as head and neck examination skills, resulting in a share of students that have only been taught such ENT-specific examination skills with online courses; our study aimed to measure performance and capacity of self-evaluation in these students. After completing a new extensive online Ear Nose Throat (ENT) examination course, we conducted a standardized clinical skills exam for nine different ENT examination items with 31 students. Using Likert scales, self-evaluation was based on questionnaires right before the clinical skills exam and objective evaluation during the exam was assessed following a standardized regime. Self-evaluation and objective evaluation were correlated. To compare the exclusive online teaching to traditional hands-on training, a historic cohort with 91 students was used. Objective examination performance after in-classroom or online teaching varied for single examination items while overall assessment remained comparable. Overall, self-evaluation did not differ significantly after online-only and in-classroom ENT skill teaching. Nevertheless, misjudgment of one’s skill level increased after online-only training compared to in-classroom teaching. Highest levels of overestimation were observed after online training in simple tasks. While gender and interest in ENT did not influence self-evaluation and misjudgment, higher age of participants was associated with an overestimation of skills. Medical students with online-only training during the COVID-19 pandemic achieved similar ENT examination skills to those with traditional on-campus training before the pandemic. Nevertheless, students with online-only training were more prone to misjudge their skills when they assessed their skills. Due to the COVID-19 pandemic, current medical students and graduates might therefore lack individual specific psychomotor skills such as the ENT examination, underlining the importance of presence-based teaching

    Relationship of a common polymorphism of the glucocorticoid receptor gene to traumatic memories and posttraumatic stress disorder in patients after intensive care therapy

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    Glucocorticoids play a major role in the consolidation and retrieval of traumatic information. They act through the glucocorticoid receptor, for which, in humans, several polymorphisms have been described. In particular, the BclI single-nucleotide polymorphism is associated with hypersensitivity to glucocorticoids and with susceptibility to development of major depression. Furthermore, in patients with posttraumatic stress disorder carrying the BclI GG genotype, cortisol levels were lower and showed an inverse relationship to posttraumatic stress disorder symptom intensity. Here, we studied the association of the BclI polymorphism with plasma cortisol levels, traumatic memories, posttraumatic stress disorder symptoms, and health-related quality of life outcomes in 126 patients undergoing cardiac surgery and intensive care unit therapy.; Prospective observational study.; Cardiovascular intensive care unit in a university hospital.; A total of 126 patients undergoing cardiac surgery and intensive care unit treatment.; No interventions were performed.; Validated questionnaires were used to quantify end points. Measurements were taken 1 day before and 1 wk and 6 months after cardiac surgery. Homozygous carriers of the BclI G allele (n = 21) had significantly lower preoperative plasma cortisol levels and more long-term traumatic memories from intensive care unit therapy at 6 months after cardiac surgery than heterozygous carriers or noncarriers (1.9 ± 1.4 vs. 1.0 ± 1.2, p = .01). Anxiety was significantly more common as a long-term traumatic memory in homozygous BclI G allele carriers than in heterozygous carriers or noncarriers (57% vs. 35%, p = .03). Posttraumatic stress disorder symptom scores were significantly higher at discharge from the intensive care unit in homozygous BclI G allele carriers than in heterozygous carriers or noncarriers. Only heterozygous carriers or BclI G allele noncarriers had a significant gain in health-related quality of life physical function at 6 months after cardiac surgery (p > .01). Baseline values were not statistically different between carriers of the different BclI alleles.; Homozygous BclI G allele carriers are at risk for traumatic memories, posttraumatic stress disorder symptoms, and lower health-related quality of life after cardiac surgery and intensive care unit therapy. The BclI single-nucleotide polymorphism may help to identify individuals at need for tailored medical care
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