9 research outputs found

    Summary statistics from training images as prior information in probabilistic inversion

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    A strategy is presented to incorporate prior information from conceptual geological models in probabilistic inversion of geophysical data. The conceptual geological models are represented by multiple-point statistics training images (TIs) featuring the expected lithological units and structural patterns. Information from an ensemble of TI realizations is used in two different ways. First, dominant modes are identified by analysis of the frequency content in the realizations, which drastically reduces the model parameter space in the frequency-amplitude domain. Second, the distributions of global, summary metrics (e.g. model roughness) are used to formulate a prior probability density function. The inverse problem is formulated in a Bayesian framework and the posterior pdf is sampled using Markov chain Monte Carlo simulation. The usefulness and applicability of this method is demonstrated on two case studies in which synthetic crosshole ground-penetrating radar traveltime data are inverted to recover 2-D porosity fields. The use of prior information from TIs significantly enhances the reliability of the posterior models by removing inversion artefacts and improving individual parameter estimates. The proposed methodology reduces the ambiguity inherent in the inversion of high-dimensional parameter spaces, accommodates a wide range of summary statistics and geophysical forward problem

    Conditioning of Multiple-Point Statistics Facies Simulations to Tomographic Images

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    Geophysical tomography captures the spatial distribution of the underlying geophysical property at a relatively high resolution, but the tomographic images tend to be blurred representations of reality and generally fail to reproduce sharp interfaces. Such models may cause significant bias when taken as a basis for predictive flow and transport modeling and are unsuitable for uncertainty assessment. We present a methodology in which tomograms are used to condition multiple-point statistics (MPS) simulations. Alarge set of geologically reasonable facies realizations and their corresponding synthetically calculated cross-hole radar tomograms are used as a training image. The training image is scanned with a direct sampling algorithm for patterns in the conditioning tomogram, while accounting for the spatially varying resolution of the tomograms. In a post-processing step, only those conditional simulations that predicted the radar traveltimes within the expected data error levels are accepted. The methodology is demonstrated on a two-facies example featuring channels and an aquifer analog of alluvial sedimentary structures with five facies. For both cases, MPS simulations exhibit the sharp interfaces and the geological patterns found in the training image. Compared to unconditioned MPS simulations, the uncertainty in transport predictions is markedly decreased for simulations conditioned to tomograms. As an improvement to other approaches relying on classical smoothness-constrained geophysical tomography, the proposed method allows for: (1)reproduction of sharp interfaces, (2)incorporation of realistic geological constraints and (3)generation of multiple realizations that enables uncertainty assessment

    Nichtraucherschutz und Tabakentwöhnung: Ein Thema für Mitarbeitende in Einrichtungen der deutschen Kinder- und Jugendpsychiatrie?

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    Fragestellung: Mitarbeitende in kinder- und jugendpsychiatrischen (KJP) Einrichtungen stehen im Spannungsverhältnis zwischen der Durchsetzung von Rauchverboten für Patient_innen und dem eigenen Rauchverhalten. Bisher fehlen Daten, ob und wo Mitarbeitende rauchen und welche Entwöhnungsangebote KJP-Einrichtungen ihnen anbieten. Methodik: In einer Onlinestudie beantworteten n = 78 leitende Mitarbeitende deutscher KJP-Einrichtungen (41.9 % aller Angeschriebenen) Fragen zu stationsübergreifenden sowie stationsspezifischen Nichtraucherschutzmaßnahmen sowie zu Tabakentwöhnungsmaßnahmen. Ergebnisse: Umfassende Rauchverbote werden selten umgesetzt (< 20 % der Einrichtungen). Mitarbeitende dürfen vorrangig im Außengelände rauchen (z. B. in Raucherzonen: 69 bis 78 % je nach Stationstyp). Entwöhnungsangebote für Mitarbeitende bietet nur jede zweite KJP an (47 %). Schlussfolgerungen: Die Daten weisen auf zukünftige Handlungsfelder der Tabakkontrolle in der KJP-Pflege hin: transparente Regeln, Weiterbildungen und Ausbau betrieblicher Entwöhnungsangebote.Objective: Whereas, on the one hand, employees in child and adolescent psychiatric institutions (CAP) have to enforce smoking bans among patients, on the other hand, they have a high likelihood of being smokers themselves. Little data are available on the enforcement of smoking regulations and what cessation support is offered by CAP institutions. Method: In an online survey, n = 78 senior staff members or directors of German CAP institutions (41.9 % of all addressed CAP institutions) responded to questions on smoking regulations, exceptions, and cessation support for employees. Results: The enforcement of comprehensive smoking bans is rarely reported (<20 % of CAP institutions). Employees are exempted or allowed to smoke mostly outside of the building (e. g., in designated smoking areas: 69-78 % depending on ward type). Cessation support was offered by less than half of the CAP institutions (47%). Conclusions: The data presented point toward future areas for tobacco control in CAP care, including transparent regulations, staff training, and dissemination of support for occupational smoking cessation

    Predictors and outcomes in primary depression care (POKAL) – a research training group develops an innovative approach to collaborative care

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    BACKGROUND: The interdisciplinary research training group (POKAL) aims to improve care for patients with depression and multimorbidity in primary care. POKAL includes nine projects within the framework of the Chronic Care Model (CCM). In addition, POKAL will train young (mental) health professionals in research competences within primary care settings. POKAL will address specific challenges in diagnosis (reliability of diagnosis, ignoring suicidal risks), in treatment (insufficient patient involvement, highly fragmented care and inappropriate long-time anti-depressive medication) and in implementation of innovations (insufficient guideline adherence, use of irrelevant patient outcomes, ignoring relevant context factors) in primary depression care. METHODS: In 2021 POKAL started with a first group of 16 trainees in general practice (GPs), pharmacy, psychology, public health, informatics, etc. The program is scheduled for at least 6 years, so a second group of trainees starting in 2024 will also have three years of research-time. Experienced principal investigators (PIs) supervise all trainees in their specific projects. All projects refer to the CCM and focus on the diagnostic, therapeutic, and implementation challenges. RESULTS: The first cohort of the POKAL research training group will develop and test new depression-specific diagnostics (hermeneutical strategies, predicting models, screening for suicidal ideation), treatment (primary-care based psycho-education, modulating factors in depression monitoring, strategies of de-prescribing) and implementation in primary care (guideline implementation, use of patient-assessed data, identification of relevant context factors). Based on those results the second cohort of trainees and their PIs will run two major trials to proof innovations in primary care-based a) diagnostics and b) treatment for depression. CONCLUSION: The research and training programme POKAL aims to provide appropriate approaches for depression diagnosis and treatment in primary care

    Nichtraucherschutz und Tabakentwöhnung

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    Fragestellung: Mitarbeitende in kinder- und jugendpsychiatrischen (KJP) Einrichtungen stehen im Spannungsverhältnis zwischen der Durchsetzung von Rauchverboten für Patientinnen und Patienten und dem eigenen Rauchverhalten. Bisher fehlen Daten, ob und wo Mitarbeitende rauchen und welche Entwöhnungsangebote KJP-Einrichtungen ihnen anbieten. Methodik: In einer Onlinestudie beantworteten n = 78 leitende Mitarbeitende deutscher KJP-Einrichtungen (41.9 % aller Angeschriebenen) Fragen zu stationsübergreifenden sowie stationsspezifischen Nichtraucherschutzmaßnahmen sowie zu Tabakentwöhnungsmaßnahmen. Ergebnisse: Umfassende Rauchverbote werden selten umgesetzt (&amp;lt; 20 % der Einrichtungen). Mitarbeitende dürfen vorrangig im Außengelände rauchen (z. B. in Raucherzonen: 69 bis 78 % je nach Stationstyp). Entwöhnungsangebote für Mitarbeitende bietet nur jede zweite KJP an (47 %). Schlussfolgerungen: Die Daten weisen auf zukünftige Handlungsfelder der Tabakkontrolle in der KJP-Pflege hin: transparente Regeln, Weiterbildungen und Ausbau betrieblicher Entwöhnungsangebote
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