256 research outputs found

    BRST Cohomology and Phase Space Reduction in Deformation Quantisation

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    In this article we consider quantum phase space reduction when zero is a regular value of the momentum map. By analogy with the classical case we define the BRST cohomology in the framework of deformation quantization. We compute the quantum BRST cohomology in terms of a `quantum' Chevalley-Eilenberg cohomology of the Lie algebra on the constraint surface. To prove this result, we construct an explicit chain homotopy, both in the classical and quantum case, which is constructed out of a prolongation of functions on the constraint surface. We have observed the phenomenon that the quantum BRST cohomology cannot always be used for quantum reduction, because generally its zero part is no longer a deformation of the space of all smooth functions on the reduced phase space. But in case the group action is `sufficiently nice', e.g. proper (which is the case for all compact Lie group actions), it is shown for a strongly invariant star product that the BRST procedure always induces a star product on the reduced phase space in a rather explicit and natural way. Simple examples and counter examples are discussed.Comment: LaTeX2e, 34 pages, revised version: minor changes and corrected typo

    Individuals\u27 Concerns Associated with Digital Healthcare: Professionals\u27 and Patients\u27 Hindrances to Adopt Digital Healthcare Services

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    Healthcare systems are facing enormous changes as digital technologies find their way to address current challenges. To foster acceptance of digital healthcare services in the future and support the digital transformation of healthcare, it is crucial to understand and overcome individuals’ concerns associated with the adoption of digital technologies. This paper presents eleven concerns structured along four categories deduced from an in-depth interview study with 26 healthcare professionals and patients. Further, we mapped these individual concerns as exogenous mechanisms on the well-established Unified Theory of Acceptance and Use of Technologies (UTAUT) and discuss general implications for digital technology adoption in healthcare. Our paper is a first step towards addressing relevant concerns and can be used – either ex-ante or ex-post – to anticipate, explain, or evaluate problems with the adoption of digital healthcare services

    Reading profiles in secondary school: concurrent language and cognitive abilities, and retrospective and prospective reading skills

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    IntroductionWe examined the concurrent language and cognitive abilities in a group of Swedish students with different reading profiles in secondary school, and the retrospective (primary school) and prospective (upper-secondary school) reading skills of each reading profile.MethodsSeventy-nine students participated in data collections in primary (grade 2: age 8), secondary (grade 8: age 14) and upper-secondary school (year 2: age 17). Independent variables included measures of word recognition, and vocabulary and text comprehension in secondary school. Dependent variables included measures of phonemic awareness, verbal fluency, listening comprehension, spelling, verbal working memory and nonverbal reasoning skills in secondary school, and word recognition and reading comprehension in primary and upper-secondary school.ResultsWhen exploring the concurrent language and cognitive abilities of the reading profiles in secondary school, spelling emerged as a weakness and listening comprehension as a strength for students with poor decoding. Students with poor comprehension experienced weaknesses in spelling, and non-verbal reasoning. Students with both poor decoding and comprehension displayed a multi-deficit profile in language and cognition. As regards the retrospective and prospective reading skills, the relative ranking of the reading profiles was rather consistent in both primary and upper-secondary school.DiscussionThe findings suggest that limitations in phonological awareness may not be a prominent feature of secondary school students with poor decoding in more transparent orthographies. From an educational perspective, spoken sources may support learning among students with poor decoding, whereas students with poor comprehension or combined difficulties in decoding and comprehension need support when learning from both spoken and written sources

    E-Learning: Aktueller Stand und Chancen in der Allgemeinmedizin Frankfurt a.M. 08. - 09. Juli 2005 : vom Kongress zum Netzwerk "ELA" (E-Learning in der Allgemeinmedizin)

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    Kongressbericht: Auf der Tagung der Deutschen Gesellschaft fĂŒr Allgemeinmedizin und Familienmedizin e.V. (DEGAM) 2004 entstand die Idee, E-Learning-AktivitĂ€ten in der Allgemeinmedizin sichtbar zu machen und zu bĂŒndeln. Ein Kongress sollte die allgemeinmedizinischen Vertreter aus Lehre und Forschung sowie Industrievertreter zusammenbringen, um das Spektrum der Möglichkeiten und laufende Projekte kennen zu lernen. Mit motivierten Referenten, ĂŒber 60 aktiven Teilnehmern und einem positiven Feedback, kann der Kongress in Frankfurt am 8. und 9. Juli 2005 als erster dieser Art in Deutschland als erfolgreich bezeichnet werden

    Algorithm for real-time analysis of intracoronary electrocardiogram.

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    Introduction Since its first implementation in 1985, intracoronary (ic) electrocardiogram (ECG) has shown ample evidence for its diagnostic value given the higher sensitivity for myocardial ischemia detection in comparison to surface ECG. However, a lack of online systems to quantitatively analyze icECG in real-time prevents its routine use. The present study aimed to develop and validate an autonomous icECG analyzing algorithm. Materials and methods This is a retrospective observational study in 100 patients with chronic coronary syndrome. From each patient, a non-ischemic as well as ischemic icECG at the end of a 1-min proximal coronary balloon occlusion was available. An ECG expert as well as the newly developed algorithm for autonomous icECG analysis measured the icECG ST-segment shift in mV for each icECG tracing. Results Intraclass correlation coefficient (ICC) demonstrated low variability between the two methods (ICC = 0.968). Using the time point of icECG recording as allocation reference for absent or present myocardial ischemia, ROC-analysis for ischemia detection by the manually determined icECG ST-segment shift showed an area under the curve (AUC) of 0.968 ± 0.021 (p < 0.0001). AUC for the algorithm analysis was 0.967 ± 0.023 (p < 0.0001; p = 0.925 for the difference between the ROC curve AUCs). Time to complete analysis was below 1,000 ms for the autonomous icECG analysis and above 5 min for manual analysis. Conclusion A newly developed autonomous icECG analysing algorithm detects myocardial ischemia with equal accuracy as manual ST-segment shift assessment. The algorithm provides the technical fundament for an analysing system to quantitatively obtain icECG in real-time

    Self-efficacy for writing and written text quality of upper secondary students with and without reading difficulties

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    IntroductionSelf-efficacy for writing (SEW) and reading ability are some of several factors that may be related to the quality of written text that students produce. The aim of the current study was (1) to explore the variation in SEW and written text quality in L1-Swedish and L2-English among upper secondary students with different reading profiles in L1 (typical reading vs. reading difficulties) and with different study backgrounds (SB1year or SB2years = one or two years of studies of Swedish and English, respectively), and in the next step (2) to explore if individual variations in L1-reading and SEW may explain variation in written text quality.MethodsParticipants were 100 upper secondary students (aged 17–18) with different reading profiles operationalized as typical reading and reading difficulties. Data consisted of screening for word recognition and reading comprehension, text quality results from argumentative L1- and L2-writing tasks, school information on study background in Swedish/English, and students’ responses from an online survey about SEW.ResultsAs to SEW results, an ANOVA revealed significant main effects for reading profile and study background in L1, but in L2 there was only a significant main effect for reading profile. Written text quality results indicated that there was a significant interaction effect between reading profile and study background in L1, indicating that the significant main effect for reading profile on written text quality was influenced by the group of students with reading difficulties and SB1year. There was a significant main effect for reading profile and study background on written text quality in L2. Students with reading difficulties and SB1year were the most vulnerable group, and they had the lowest scores in L1/L2 SEW and written text quality in L1 and L2. Multiple regression results indicated that word recognition and SEW contributed significantly to L1-text quality, and word recognition, reading comprehension, and SEW contributed significantly to L2-text quality. Thus, this study sheds light on the under-researched area of L1/L2 SEW and text quality of students with reading difficulties at the level of upper secondary school.DiscussionPedagogical implications are discussed and highlight the need for writing instruction across subjects in upper secondary school and for extra writing support/scaffolding for students with reading difficulties and shorter study background in the language subjects L1 (Swedish) and L2 (English)

    MaterialitÀt - Digitalisierung - Bildung. Neomaterialistische Perspektiven

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    Vor dem Hintergrund einer eher zögerlichen Rezeption des New Materialism in der Erziehungswissenschaft zielt der Beitrag darauf ab, sechs neomaterialistische Positionen fĂŒr die Trias MaterialitĂ€t – Digitalisierung – Bildung zur Diskussion zu stellen. Der Beitrag endet mit einem bilanzierenden Fazit und gibt Ausblicke auf weitere Forschungsfragen. (DIPF/Orig.

    Tracks in the Snow - Advantage of Combining Optical Methods to Characterize Marine Particles and Aggregates

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    Settling marine aggregates, such as zooplankton fecal pellets and marine snow, transport organic matter from the surface ocean to the deep sea and are largely responsible for the ocean’s sequestration of carbon. However, our understanding of the functioning of the biological pump and the distribution of particulate organic matter in the water column often hinge on limited bulk data from sediment traps, large volume ïŹltration or instantaneous snap-shots from in situ optical systems that only see a small part of the particle and aggregate spectra. We evaluated the added value of combining different optical systems to detect a range of organic and inorganic particle types during a case-study in the Cape Blanc upwelling region. Laboratory calibrations showed that one camera system detected large organic aggregates well and in situ data showed that it correlated positively with ïŹ‚uorescence. The other camera was better at detecting small, mainly inorganic particles which were not seen by the ïŹrst camera and correlated positively with turbidity. The combined deployments of the two optical systems together with ïŹ‚uorescence and turbidity sensors showed potentials for added insights into spatial (depth) and temporal (diurnal) particle dynamics. The case study exempliïŹed the different efïŹciencies of two camera systems to detect particles of different types in marine waters. From this, the results highlighted the importance of discriminating between qualitative and quantitative ranges of imaging systems, in order to understand the quantitative range of sizes as well as types of particles detected by a given system. This is especially important when optical systems are used to estimate carbon ïŹ‚uxes and particulate organic matter distribution in the water column from vertical proïŹles of particle size-distribution and abundance
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