186 research outputs found

    Discrete-event simulation unmasks the quantum Cheshire Cat

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    It is shown that discrete-event simulation accurately reproduces the experimental data of a single-neutron interferometry experiment [T. Denkmayr {\sl et al.}, Nat. Commun. 5, 4492 (2014)] and provides a logically consistent, paradox-free, cause-and-effect explanation of the quantum Cheshire cat effect without invoking the notion that the neutron and its magnetic moment separate. Describing the experimental neutron data using weak-measurement theory is shown to be useless for unravelling the quantum Cheshire cat effect

    Benchmarking gate-based quantum computers

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    With the advent of public access to small gate-based quantum processors, it becomes necessary to develop a benchmarking methodology such that independent researchers can validate the operation of these processors. We explore the usefulness of a number of simple quantum circuits as benchmarks for gate-based quantum computing devices and show that circuits performing identity operations are very simple, scalable and sensitive to gate errors and are therefore very well suited for this task. We illustrate the procedure by presenting benchmark results for the IBM Quantum Experience, a cloud-based platform for gate-based quantum computing.Comment: Accepted for publication in Computer Physics Communication

    Complications, Reoperations, and Nutrient Deficiencies Two Years after Sleeve Gastrectomy

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    Background. The aim of this study was to investigate patient outcomes and nutritional deficiencies following sleeve gastrectomy (SG) during a follow-up of two years. Methods. Over a period of 56 months, all consecutive patients who underwent SG were documented in this prospective, single-center, observational study. The study endpoints included operative time, complication rates, nutritional deficiencies and percentage of excess weight loss (%EWL). Results. From September 26, 2005 to May 28, 2009, 82 patients (female : male = 48 : 34) with a mean age of 43.3 years (range: 22–64) and a preoperative BMI of 52.5 kg/m² (range: 36.8–77.0) underwent SG. Major complications were observed in 9.8% of the patients, with 1 death. During follow up 51.2% of patients were supplemented with iron, 36.6% with zinc, 37.8% with calcium, 26.8% with vitamin D, 46.3% with vitamin B12 and 41.5% with folic acid. %EWL was 54.3, 65.3 and 62.6% after 6, 12 and 24 months. Conclusion. SG as a single step procedure is an effective bariatric intervention. Nutritional deficiencies after SG can be detected by routine nutritional screening. Our results show that Vitamin B12 supplementation should suggest routinely after SG

    Effective Mobile Marketing : eine empirische Untersuchung

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    Mit jährlich mehr als 20 Mrd. versendeten SMS-Nachrichten und fast 35 Mrd. Telefonminuten hat sich das Mobiltelefon zum Kommunikationsmedium Nummer eins in Deutschland entwickelt. Aufgrund des herausragenden Erfolges der Mobiltelefonie steigt das Interesse werbetreibender Unternehmen an der Verwendung dieses Mediums zum Zwecke der werblichen Kommunikation. Nach Ansicht von Branchenspezialisten hat Mobile Marketing das Potenzial, eine neue Epoche der Kommunikationspolitik einzuleiten. Das Handy ist das erste interaktive und zugleich persönlichste Massenmedium unserer Zeit. Mit keinem anderen Medium lassen sich mehr Menschen in kürzerer Zeit und mit minimalen Streuverlusten erreichen. Wenn Mobile Marketing-Kampagnen funktionieren sollen, muss man die Möglichkeiten des Mediums kennen und entsprechend den Marketingzielen des Kunden ausnutzen. Das Management-Know-How-Papier beleuchtet daher zunächst die Grundlagen des Mobile Marketing und zeigt anhand von drei Mobile Marketing-Kampagnen beispielhaft, welche Faktoren den Einsatz des Werbemediums Handy zum Erfolg werden lassen. Abschließend wird ein Kriterienkatalog zur erfolgreichen Implementierung von Mobile Marketing-Kampagnen abgeleitet

    The influence of polymorbidity, revascularization, and wound therapy on the healing of arterial ulceration

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    Joerg Tautenhahn1, Ralf Lobmann2, Brigitte Koenig3, Zuhir Halloul1, Hans Lippert1, Thomas Buerger11Department of General, Visceral and Vascular Surgery; 2Department of Endocrinology and Metabolism; 3Institute for Medical Microbiology, Medical School, Otto-von-Guericke University, Magdeburg, GermanyObjective: An ulcer categorized as Fontaine’s stage IV represents a chronic wound, risk factor of arteriosclerosis, and co-morbidities which disturb wound healing. Our objective was to analyze wound healing and to assess potential factors affecting the healing process.Methods: 199 patients were included in this 5-year study. The significance levels were determined by chi-squared and log-rank tests. The calculation of patency rate followed the Kaplan-Meier method.Results: Mean age and co-morbidities did not differ from those in current epidemiological studies. Of the patients with ulcer latency of more than 13 weeks (up to one year), 40% required vascular surgery. Vascular surgery was not possible for 53 patients and they were treated conservatively. The amputation rate in the conservatively treated group was 37%, whereas in the revascularizated group it was only 16%. Ulcers in patients with revascularization healed in 92% of cases after 24 weeks. In contrast, we found a healing rate of only 40% in the conservatively treated group (p < 0.001). Revascularization appeared more often in diabetic patients (n = 110; p < 0.01) and the wound size and number of infections were elevated (p = 0.03). Among those treated conservatively, wound healing was decelerated (p = 0.01/0.02; χ² test).Conclusions: The success of revascularization, presence of diabetes mellitus, and wound treatment proved to be prognostic factors for wound healing in arterial ulcers.Keywords: arterial leg ulcer, wound management, risk factors, revascularizatio

    CAVE: An Open-Source Tool for Combined Analysis of Head-Mounted Calcium Imaging and Behavior in MATLAB

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    Calcium imaging in freely behaving rodents using head-mounted miniature microscopes is currently becoming an increasingly popular technique in neuroscience. Due to the large amounts of complex data that the technique produces, user friendly software is needed for quick and efficient processing. Here, we present a new tool for analyzing calcium imaging data from head-mounted microscopes together with simultaneously acquired behavioral data: CAVE (Calcium ActiVity Explorer). CAVE bundles a unique set of algorithms specifically tailored to the analysis of single-photon imaging data from awake behaving animals including efficient motion correction and automatic ROI selection with manual audit and refinement. For behavioral analysis, CAVE can automatically track animal position and orientation. Individual behavioral epochs and external events can then be analyzed in correlation to calcium imaging and tracking data. Our program is written in MATLAB, the source code is open source and particularly focuses on providing a streamlined workflow for novice users while also retaining detailed configuration options for advanced users. We evaluate the performance of CAVE by investigating neural activity in hippocampus and somatosensory cortex. The fast analysis provided by CAVE allowed us to track activity in a large set of animals over the course of several months during exploration behavior, detailing the properties of onset and offset of observable activity and the visible cells per imaging location

    Distance to invasive heart centre, performance of acute coronary angiography, and angioplasty and associated outcome in out-of-hospital cardiac arrest:a nationwide study

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    Aims To evaluate whether the distance from the site of event to an invasive heart centre, acute coronary angiography (CAG)/percutaneous coronary intervention (PCI) and hospital-level of care (invasive heart centre vs. local hospital) is associated with survival in out-of-hospital cardiac arrest (OHCA) patients. Methods and results Nationwide historical follow-up study of 41 186 unselected OHCA patients, in whom resuscitation was attempted between 2001 and 2013, identified through the Danish Cardiac Arrest Registry. We observed an increase in the proportion of patients receiving bystander CPR (18% in 2001, 60% in 2013, P &amp;lt; 0.001), achieving return of spontaneous circulation (ROSC) (10% in 2001, 29% in 2013, P &amp;lt; 0.001) and being admitted directly to an invasive centre (26% in 2001, 45% in 2013, P &amp;lt; 0.001). Simultaneously, 30-day survival rose from 5% in 2001 to 12% in 2013, P &amp;lt; 0.001. Among patients achieving ROSC, a larger proportion underwent acute CAG/PCI (5% in 2001, 27% in 2013, P &amp;lt; 0.001). The proportion of patients undergoing acute CAG/PCI annually in each region was defined as the CAG/PCI index. The following variables were associated with lower mortality in multivariable analyses: direct admission to invasive heart centre (HR 0.91, 95% CI: 0.89–0.93), CAG/PCI index (HR 0.33, 95% CI: 0.25–0.45), population density above 2000 per square kilometre (HR 0.94, 95% CI: 0.89–0.98), bystander CPR (HR 0.97, 95% CI: 0.95–0.99) and witnessed OHCA (HR 0.87, 95% CI: 0.85–0.89), whereas distance to the nearest invasive centre was not associated with survival. Conclusion Admission to an invasive heart centre and regional performance of acute CAG/PCI were associated with improved survival in OHCA patients, whereas distance to the invasive centre was not. These results support a centralized strategy for immediate post-resuscitation care in OHCA patients. </jats:sec
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