119 research outputs found

    Der Zusammenhang zwischen Produktivität und Standortfaktoren analysiert basierend auf Forstinventurdaten

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    This thesis aims at developing statistical models that describe the relationship between productivity or mortality and site factors, particularly climate factors. The focus lies on predictions for Norway spruce (Picea abies [L.] Karst.) and European beech (Fagus sylvatica L.) in Germany. Large-scale forest inventories provide data covering the wide climatic gradients required for model application to future climate scenarios. Thus, at the same time, this thesis explores the potential as well as the limitations of large-scale forest inventories to investigate forest growth.Ziel der vorliegenden Arbeit ist es statistische Modelle zu entwickeln, die den Zusammenhang zwischen Produktivität bzw. Mortalität auf der einen Seite und Standortfaktoren auf der anderen Seite beschreiben. Der Schwerpunkt liegt auf Vorhersagen für Fichte (Picea abies [L.] Karst.) und Buche (Fagus sylvatica L.) in Deutschland. Die Daten von großräumigen Forstinventuren decken weite Klimagradienten ab, welche die Voraussetzung für eine Anwendung der Modelle auf zukünftige Klimaszenarien bilden. Damit lotet diese Arbeit gleichzeitig sowohl die Möglichkeiten als auch die Grenzen der Verwendung großräumiger Forstinventurdaten für die Waldwachstumsforschung aus

    Climate change and mixed forests: how do altered survival probabilities impact economically desirable species proportions of Norway spruce and European beech?

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    International audienceKey message Economic consequences of altered survival probabilities under climate change should be considered for regeneration planning in Southeast Germany. Findings suggest that species compositions of mixed stands obtained from continuous optimization may buffer but not completely mitigate economic consequences. Mixed stands of Norway spruce (Picea abiesL. Karst.) and European beech (Fagus sylvaticaL.) (considering biophysical interactions between tree species) were found to be more robust, against both perturbations in survival probabilities and economic input variables, compared to block mixtures (excluding biophysical interactions).ContextClimate change is expected to increase natural hazards in European forests. Uncertainty in expected tree mortality and resulting potential economic consequences complicate regeneration decisions.AimsThis study aims to analyze the economic consequences of altered survival probabilities for mixing Norway spruce (Picea abies L. Karst.) and European beech (Fagus sylvatica L.) under different climate change scenarios. We investigate whether management strategies such as species selection and type of mixture (mixed stands vs. block mixture) could mitigate adverse financial effects of climate change.MethodsThe bio-economic modelling approach combines a parametric survival model with modern portfolio theory. We estimate the economically optimal species mix under climate change, accounting for the biophysical and economic effects of tree mixtures. The approach is demonstrated using an example from Southeast Germany.ResultsThe optimal tree species mixtures under simulated climate change effects could buffer but not completely mitigate undesirable economic consequences. Even under optimally mixed forest stands, the risk-adjusted economic value decreased by 28%. Mixed stands economically outperform block mixtures for all climate scenarios.ConclusionOur results underline the importance of mixed stands to mitigate the economic consequences of climate change. Mechanistic bio-economic models help to understand consequences of uncertain input variables and to design purposeful adaptation strategies

    Ansätze zur Förderung akademischer Schreibkompetenz an der Hochschule

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    Die qualifizierte sprachliche Betreuung internationaler Studierender während des Fachstudiums an deutschen Hochschulen hat in den letzten Jahren zunehmend an Bedeutung gewonnen. Der Fachverband Deutsch als Fremdsprache hat sich daher die Aufgabe gestellt, der studienbegleitenden Förderung der zentralen Kompetenzen, die für ein erfolgreiches Studium maßgeblich sind, verstärkte Aufmerksamkeit zu widmen. Die in diesem Band dokumentierte Fachtagung ist ein Auftakt dazu. Im Zentrum stehen Berichte und Diskussionen über Theorie und Praxis von Konzepten und Lehr-/ Lernmaterialien zum akademischen Schreiben in der Fremdsprache Deutsch, welche derzeit fachspezifisch oder fächerübergreifend in Kursen oder individuellen Schreibberatungen für verschiedene Zielgruppen an Hochschulen (Erasmus-, Bachelor-, Masterstudierende oder Promovierende) eingesetzt werden

    Possibilities and Limitations of Spatially Explicit Site Index Modelling for Spruce Based on National Forest Inventory Data and Digital Maps of Soil and Climate in Bavaria (SE Germany)

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    Combining national forest inventory (NFI) data with digital site maps of high resolution enables spatially explicit predictions of site productivity. The aim of this study is to explore the possibilities and limitations of this database to analyze the environmental dependency of height-growth of Norway spruce and to predict site index (SI) on a scale that is relevant for local forest management. The study region is the German federal state of Bavaria. The exploratory methods comprise significance tests and hypervolume-analysis. SI is modeled with a Generalized Additive Model (GAM). In a second step the residuals are modeled using Boosted Regression Trees (BRT). The interaction between temperature regime and water supply strongly determined height growth. At sites with very similar temperature regime and water supply, greater heights were reached if the depth gradient of base saturation was favorable. Statistical model criteria (Double Penalty Selection, AIC) preferred composite variables for water supply and the supply of basic cations. The ability to predict SI on a local scale was limited due to the difficulty to integrate soil variables into the model

    Factors associated with generic health-related quality of life (HRQOL) in patients with chronic obstructive pulmonary disease (COPD): a cross-sectional study

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    Background: Health-related quality of life (HRQOL) is impaired in chronic obstructive pulmonary disease (COPD) patients, but determining factors for HRQOL are still not unequivocal. This study measures HRQOL among patients with COPD and aims to determine factors associated with HRQOL. Methods: Data for cross-sectional analyses were obtained from the baseline of a cohort study. The study population includes adult COPD patients (disease duration >= 3 months), recruited from primary and secondary care settings in Germany, without acute psychiatric/neurologic disease (exception: affective/anxiety disorders). HRQOL was assessed using the Short-Form 12 (SF-12) Health Survey Questionnaire, comprising a physical and mental component. Independent variables encompass socio-demographic, disease-specific, treatment-related and psychological factors. Multivariable linear regression analyses were conducted. Results: In total, 206 COPD patients (60.7% male; mean age: 65.3 years) took part in the study. In multivariable analysis, the physical component score showed a significant negative association with the COPD Assessment Test (CAT) (P<0.001) and a higher total number of prescribed medications (P=0.001). A higher forced expiratory volume in 1 second (FEV1) value in percent predicted was significantly related to the physical component score in a positive manner (P=0.006). The mental component score was significantly associated with elevated patient-reported symptoms of anxiety (P=0.002) or depression (P<0.001), measured by the hospital anxiety and depression scale (HADS) in a negative way. Like for the physical component score (P<0.001), a worse CAT score was significantly associated with a lower mental component score (P=0.033). Conclusions: Focusing on patient reported outcomes and screening for depression and anxiety with potential successive treatment might be promising approaches to improve HRQOL in patients with COPD

    Acceptability of a German multicentre healthcare research study: a survey of research personnels’ attitudes, experiences and work load

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    Objectives The DACAPO study as a multicentre nationwide observational healthcare research study investigates the influence of quality of care on the quality of life in patients with acute respiratory distress syndrome. The aim of this study was to investigate the acceptability to the participating research personnels by assessing attitudes, experiences and workload associated with the conduct of the DACAPO study. Design, setting and participants A prospective anonymous online survey was sent via email account to 169 participants in 65 study centres. The questionnaire included six different domains: (1) training for performing the study; (2) obtaining informed consent; (3) data collection; (4) data entry using the online documentation system; (5) opinion towards the study and (6) personal data. Descriptive data analysis was carried out. Results A total of 78 participants took part (46%) in the survey, 75 questionnaires (44%) could be evaluated. 51% were senior medical specialists. 95% considered the time frame of the training as appropriate and the presentation was rated by 93% as good or very good. Time effort for obtaining consent, data collection and entry was considered by 41% as a burden. Support from the coordinating study centre was rated as good or very good by more than 90% of respondents. While the DACAPO study was seen as scientifically relevant by 81%, only 45% considered the study results valuable for improving patient care significantly. Conclusion Collecting feedback on the acceptability of a large multicentre healthcare research study provided important insights. Recruitment and data acquisition was mainly performed by physicians and often regarded as additional time burden in clinical practice. Reducing the amount of data collection and simplifying data entry could facilitate the conduct of healthcare research studies and could improve motivation of researchers in intensive care medicine. Trial registration number NCT02637011; Pre-results

    Tracheostomy in patients with acute respiratory distress syndrome is not related to quality of life, symptoms of psychiatric disorders or return-to-work: the prospective DACAPO cohort study

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    Background Acute respiratory distress syndrome (ARDS) is a life-threatening condition that often requires prolonged mechanical ventilation. Tracheostomy is a common procedure with some risks, on the other hand with potential advantages over orotracheal intubation in critically ill patients. This study investigated the association of tracheostomy with health-related quality of life (HRQoL), symptoms of psychiatric disorders and return-to-work of ARDS survivors. Methods Data were collected in the context of the prospective observational German-wide DACAPO study. Clinical and demographic patient data and treatment characteristics were obtained from the participating intensive care units (ICU). HRQoL and return-to-work were assessed using patient-reported questionnaires 3, 6 and 12 months after ICU discharge. HRQoL was measured with the Physical and Mental Component Scale of the Short-Form 12 Questionnaire (PCS-12, MCS-12). The prevalence of psychiatric symptoms (depression and post-traumatic stress disorder [PTSD]) was assessed using the Patient Health Questionnaire-9 and the Post-Traumatic Stress Syndrome-14. Physician-diagnosed anxiety and obsessive-compulsive disorder were recorded by patient self-report in the follow-up questionnaires. The associations of tracheostomy with HRQoL, psychiatric symptoms and return-to-work after 12 months were investigated by means of multivariable linear and logistic regression models. Results Primary 877 ARDS patients (mean +/- standard deviation: 54 +/- 16 years, 68% male) survived and were discharged from ICU. Out of these patients, 478 (54.5%) were tracheotomised during ICU treatment. After 12 months, patient-reported outcomes could be analysed of 388 (44.2%) respondents, 205 with tracheostomy and 183 without. One year after ICU discharge, tracheostomy showed no significant association with physical or mental health-related quality of life (PCS-12: - 0.73 [- 3.96, 2.51]; MCS-12: - 0.71 [- 4.92, 3.49]), symptoms of psychiatric disorders (depression: 0.10 [- 1.43, 1.64]; PTSD: 3.31 [- 1.81, 8.43]; anxiety: 1.26 [0.41, 3.86]; obsessive-compulsive disorder: 0.59 [0.05, 6.68]) or return-to-work (0.71 [0.31, 1.64]) in the multivariable analysis (OR [95%-CI]). Conclusions Up to 1 year after ICU discharge, neither HRQoL nor symptoms of psychiatric disorders nor return-to-work was affected by tracheostomy. Trial registration NCT02637011 (ClinicalTrials.gov, Registered 15 December 2015, retrospectively registered

    Engineered reporter phages for detection of Escherichia coli, Enterococcus, and Klebsiella in urine

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    The rapid detection and species-level differentiation of bacterial pathogens facilitates antibiotic stewardship and improves disease management. Here, we develop a rapid bacteriophage-based diagnostic assay to detect the most prevalent pathogens causing urinary tract infections: Escherichia coli, Enterococcus spp., and Klebsiella spp. For each uropathogen, two virulent phages were genetically engineered to express a nanoluciferase reporter gene upon host infection. Using 206 patient urine samples, reporter phage-induced bioluminescence was quantified to identify bacteriuria and the assay was benchmarked against conventional urinalysis. Overall, E. coli, Enterococcus spp., and Klebsiella spp. were each detected with high sensitivity (68%, 78%, 87%), specificity (99%, 99%, 99%), and accuracy (90%, 94%, 98%) at a resolution of ≥103^{3} CFU/ml within 5 h. We further demonstrate how bioluminescence in urine can be used to predict phage antibacterial activity, demonstrating the future potential of reporter phages as companion diagnostics that guide patient-phage matching prior to therapeutic phage application

    Development of a Three-Dimensional In Vitro Model for Longitudinal Observation of Cell Behavior: Monitoring by Magnetic Resonance Imaging and Optical Imaging

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    Purpose: The aim of this study is the development of a three-dimensional multicellular spheroid cell culture model for the longitudinal comparative and large-scale screening of cancer cell proliferation with noninvasive molecular imaging techniques under controlled and quantifiable conditions. Procedures: The human glioblastoma cell line Gli36ΔEGFR was genetically modified to constitutively express the fluorescence protein mCherry, and additionally labeled with iron oxide nanoparticles for high-field MRI detection. The proliferation of aggregates was longitudinally monitored with fluorescence imaging and correlated with aggregate size by light microscopy, while MRI measurements served localization in 3D space. Irradiation with γ-rays was used to detect proliferational response. Results: Cell proliferation in the stationary three-dimensonal model can be observed over days with high accuracy. A linear relationship of fluorescence intensity with cell aggregate size was found, allowing absolute quantitation of cells in a wide range of cell amounts. Glioblastoma cells showed pronounced suppression of proliferation for several days following high-dose γ-irradiation. Conclusions: Through the combination of two-dimensional optical imaging and 3D MRI, the position of individual cell aggregates and their corresponding light emission can be detected. This allows an exact quantification of cell proliferation, with a focus on very small cell amounts (below 100 cells) using high resolution noninvasive techniques as a well-controlled basis for further cell transplantation studies
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