118 results on '"Andreas M, Fischer"'
Search Results
2. Cathepsin B- and L-like Protease Activities Are Induced During Developmental Barley Leaf Senescence
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Igor A. Schepetkin and Andreas M. Fischer
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aleurain ,barley ,cysteine protease ,Hordeum vulgare L. ,leaf senescence ,protease inhibitor ,Botany ,QK1-989 - Abstract
Leaf senescence is a developmental process allowing nutrient remobilization to sink organs. Previously cysteine proteases have been found to be highly expressed during leaf senescence in different plant species. Using biochemical and immunoblotting approaches, we characterized developmental senescence of barley (Hordeum vulgare L. var. ‘GemCraft’) leaves collected from 0 to 6 weeks after the onset of flowering. A decrease in total protein and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) large subunits occurred in parallel with an increase in proteolytic activity measured using the fluorogenic substrates Z-RR-AMC, Z-FR-AMC, and casein labeled with fluorescein isothiocyanate (casein-FITC). Aminopeptidase activity detected with R-AMC peaked at week 3 and then decreased, reaching a low level by week 6. Maximal proteolytic activity with Z-FR-AMC and Z-RR-AMC was detected from pH 4.0 to pH 5.5 and pH 6.5 to pH 7.4, respectively, while two pH optima (pH 3.6 to pH 4.5 and pH 6.5 to pH 7.4) were found for casein-FITC. Compound E-64, an irreversible cysteine protease inhibitor, and CAA0225, a selective cathepsin L inhibitor, effectively inhibited proteolytic activity with IC50 values in the nanomolar range. CA-074, a selective cathepsin B inhibitor, was less potent under the same experimental conditions, with IC50 in the micromolar range. Inhibition by leupeptin and phenylmethylsulfonyl fluoride (PMSF) was weak, and pepstatin A, an inhibitor of aspartic acid proteases, had no effect at the concentrations studied (up to 0.2 mM). Maximal proteolytic activity with the aminopeptidase substrate R-AMC was detected from pH 7.0 to pH 8.0. The pH profile of DCG-04 (a biotinylated activity probe derived from E-64) binding corresponded to that found with Z-FR-AMC, suggesting that the major active proteases are related to cathepsins B and L. Moreover, immunoblotting detected increased levels of barley SAG12 orthologs and aleurain, confirming a possible role of these enzymes in senescing leaves.
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- 2024
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3. Building design in a changing climate – Future Swiss reference years for building simulations
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Kathrin Wehrli, Franz Sidler, Stefanie Gubler, Gianrico Settembrini, Markus Koschenz, Silvia Domingo Irigoyen, Sven Kotlarski, Andreas M. Fischer, and Gerhard Zweifel
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Indoor temperature ,Building design ,Climate scenario ,Urban climate ,Design reference year ,Meteorology. Climatology ,QC851-999 ,Social sciences (General) ,H1-99 - Abstract
With global climate change, temperatures in Switzerland are projected to rise in the coming decades, according to the national climate scenarios CH2018. Associated with the mean temperature increase, heatwaves are expected to become longer, more frequent, and more intense. The changing climate will affect the indoor climate as well as heating and cooling needs. In building design, these climatic changes have to be planned for today in order to ensure a comfortable indoor climate in the future.In collaboration with practitioners, a reference climate data set for the future is created that specifically targets building designers and engineers. The data set consists of hourly weather data of one-year length based on the Swiss climate change scenarios CH2018. These future reference years are representative of two time periods in the future: one around 2030 and one around 2060. Climate change uncertainty is considered by using two emission scenarios (RCP2.6 and RCP8.5). Reference data for the future is provided not only for a typical year (called Design Reference Year, or DRY) but also for an above-average warm summer. The data is available at the sites of 45 measurement stations across Switzerland, including four stations inside major cities to take the urban heat island effect into account.The generated climate data set is applied to a building model to provide an application example. The results point out that the cooling needs will substantially increase, which is why an adaptation of the building design to the changing climate is vital.
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- 2024
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4. How to provide actionable information on weather and climate impacts?–A summary of strategic, methodological, and technical perspectives
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Tobias Geiger, Thomas Röösli, David N. Bresch, Bodo Erhardt, Andreas M. Fischer, Dominik Imgrüth, Stefan Kienberger, Laura Mainetti, Gudrun Mühlbacher, and Raphael Spiekermann
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climate service ,weather and climate risk ,extreme weather and climate ,National Weather Service ,impact assessment ,co-design ,Environmental sciences ,GE1-350 - Abstract
Climate change will result in more intense and more frequent weather and climate events that will continue to cause fatalities, economic damages and other adverse societal impacts worldwide. To mitigate these consequences and to support better informed decisions and improved actions and responses, many National Meteorological and Hydrological Services (NMHSs) are discussing how to provide services on weather and climate impacts as part of their operational routines. The authors outline how a risk framework can support the development of these services by NMHSs. In addition to the hazard information, a risk perspective considers the propensity for a given hazard to inflict adverse consequences on society and environment, and attempts to quantify the uncertainties involved. The relevant strategic, methodological and technical steps are summarized and recommendations for the development of impact-related services are provided. Specifically, we propose that NMHSs adopt an integrated risk framework that incorporates a hazard-exposure-vulnerability model into operational services. Such a framework integrates all existing forecast and impact services, including the underlying impact models, and allows for flexible future extensions driven by the evolving collaboration with partners, stakeholders and users. Thereby, this paper attempts to unify existing work streams on impact-related services from different spatial and temporal scales (weather, climate) and disciplines (hydrology, meteorology, economics, social sciences) and to propose a harmonized approach that can create synergies within and across NMHSs to further develop and enhance risk-based services.
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- 2024
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5. Correcting versus resolving respiratory motion in free-breathing whole-heart MRA: a comparison in patients with thoracic aortic disease
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Robert E. Stroud, Davide Piccini, U. Joseph Schoepf, John Heerfordt, Jérôme Yerly, Lorenzo Di Sopra, Jonathan D. Rollins, Andreas M. Fischer, Pal Suranyi, and Akos Varga-Szemes
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Aorta ,Dilatation ,Image processing (computer–assisted) ,Magnetic resonance angiography ,Motion ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Background Whole-heart magnetic resonance angiography (MRA) requires sophisticated methods accounting for respiratory motion. Our purpose was to evaluate the image quality of compressed sensing-based respiratory motion-resolved three-dimensional (3D) whole-heart MRA compared with self-navigated motion-corrected whole-heart MRA in patients with known thoracic aorta dilation. Methods Twenty-five patients were prospectively enrolled in this ethically approved study. Whole-heart 1.5-T MRA was acquired using a prototype 3D radial steady-state free-precession free-breathing sequence. The same data were reconstructed with a one-dimensional motion-correction algorithm (1D-MCA) and an extradimensional golden-angle radial sparse parallel reconstruction (XD-GRASP). Subjective image quality was scored and objective image quality was quantified (signal intensity ratio, SIR; vessel sharpness). Wilcoxon, McNemar, and paired t tests were used. Results Subjective image quality was significantly higher using XD-GRASP compared to 1D-MCA (median 4.5, interquartile range 4.5–5.0 versus 4.0 [2.25–4.75]; p < 0.001), as well as signal homogeneity (3.0 [3.0–3.0] versus 2.0 [2.0–3.0]; p = 0.003), and image sharpness (3.0 [2.0–3.0] vs 2.0 [1.25–3.0]; p < 0.001). SIR with the 1D-MCA and XD-GRASP was 6.1 ± 3.9 versus 7.4 ± 2.5, respectively (p < 0.001); while signal homogeneity was 274.2 ± 265.0 versus 199.8 ± 67.2 (p = 0.129). XD-GRASP provided a higher vessel sharpness (45.3 ± 10.7 versus 40.6 ± 101, p = 0.025). Conclusions XD-GRASP-based motion-resolved reconstruction of free-breathing 3D whole-heart MRA datasets provides improved image contrast, sharpness, and signal homogeneity and seems to be a promising technique that overcomes some of the limitations of motion correction or respiratory navigator gating.
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- 2019
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6. Evaluating the added value of the new Swiss climate scenarios for hydrology: An example from the Thur catchment
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Ole Rössler, Sven Kotlarski, Andreas M. Fischer, Denise Keller, Mark Liniger, and Rolf Weingartner
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Meteorology. Climatology ,QC851-999 ,Social sciences (General) ,H1-99 - Abstract
The availability of new climate greenhouse gas scenario data often prompts the question in what respect the new data provide added value with respect to previous versions and whether or not impact models have to be rerun with the new climatic forcing. This question is the case not only for updated sets of underlying climate model ensembles but also for changes in the applied postprocessing method, such as in the upcoming new climate change projection suite CH2018. The new local projection data are no longer post-processed based on the delta change approach but using quantile mapping. Here, we evaluate the added value of new climate projections from a hydrological perspective. We propose an evaluation scheme that comprises both reference and greenhouse gas scenario periods, average values on different temporal aggregation levels, as well as extreme-related multiday indices. For a test catchment (Thur, pre-alpine, 1700 km2) we show that the question about an added value, strongly depends on the variable and aspect (average and extreme) of interest. In many cases, basic hydrological characteristics are similarly represented when employing different climate model postprocessing techniques. However, we found differences in the climate change signal already for mean monthly runoff values and even more for several extreme-related indices. Some of them reveal very similar change signals, while the indices related to the intensity/volume of the extremes can strongly diverge. We argue that the comprehensive comparative analysis presented here is transferable and provides useful guidance for the assessment an added value, especially for climate data providers and impact modellers.
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- 2019
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7. CH2018 – National climate scenarios for Switzerland: How to construct consistent multi-model projections from ensembles of opportunity
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Silje Lund Sørland, Andreas M. Fischer, Sven Kotlarski, Hans R. Künsch, Mark A. Liniger, Jan Rajczak, Christoph Schär, Curdin Spirig, Kuno Strassmann, and Reto Knutti
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Regional climate change scenarios ,Climate services ,CORDEX ,Ensembles of opportunities ,Switzerland ,Meteorology. Climatology ,QC851-999 ,Social sciences (General) ,H1-99 - Abstract
The latest Swiss Climate Scenarios (CH2018), released in November 2018, consist of several datasets derived through various methods that provide robust and relevant information on climate change in Switzerland. The scenarios build upon the regional climate model projections for Europe produced through the internationally coordinated downscaling effort EURO-CORDEX. The simulations from EURO-CORDEX consist of simulations at two spatial horizontal resolutions, several global climate models, and three different emission scenarios. Even with this unique dataset of regional climate scenarios, a number of practical challenges regarding a consistent interpretation of the model ensemble arise. Here we present the methodological chain employed in CH2018 in order to generate a multi-model ensemble that is consistent across scenarios and is used as a basis for deriving the CH2018 products. The different steps involve a thorough evaluation of the full EURO-CORDEX model ensemble, the removal of doubtful and potentially erroneous simulations, a time-shift approach to account for an equal number of simulations for each emission scenario, and the multi-model combination of simulations with different spatial resolutions. Each component of this cascade of processing steps is associated with an uncertainty that eventually contributes to the overall scientific uncertainty of the derived scenario products. We present a comparison and an assessment of the uncertainties from these individual effects and relate them to probabilistic projections. It is shown that the CH2018 scenarios are generally supported by the results from other sources. Thus, the CH2018 scenarios currently provide the best available dataset of future climate change estimates in Switzerland.
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- 2020
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8. Immigration and Swiss House Prices
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Kathrin Degen and Andreas M. Fischer
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immigration ,housing prices ,Statistics ,HA1-4737 ,Economics as a science ,HB71-74 - Abstract
Summary This study examines the behavior of Swiss house prices in relation to immigration flows for 85 regions from 2001 to 2006. The results show that the nexus between immigration and house prices holds even in an environment of low house price inflation and modest immigration flows. An immigration inflow equal to 1 % of an area’s population is coincident with an increase in prices for single-family homes of about 2.7 %, a result consistent with previous studies. The overall immigration effect for single-family houses captures almost two-thirds of the total price increase.
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- 2017
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9. Enhanced proteostasis, lipid remodeling, and nitrogen remobilization define barley flag leaf senescence
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Maja Cohen, Kendra Hertweck, Maxim Itkin, Sergey Malitsky, Bareket Dassa, Andreas M Fischer, and Robert Fluhr
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Plant Leaves ,Nitrogen ,Gene Expression Regulation, Plant ,Physiology ,Proteostasis ,Hordeum ,Plant Science ,Lipids ,Carbon ,Plant Senescence ,Transcription Factors ,Plant Proteins - Abstract
Leaf senescence is a developmental process allowing nutrient remobilization to sink organs. We characterized flag leaf senescence at 7, 14, and 21 d past anthesis in two near-isogenic barley lines varying in the allelic state of the HvNAM1 transcription factor gene, which influences senescence timing. Metabolomics and microscopy indicated that, as senescence progressed, thylakoid lipids were transiently converted to neutral lipids accumulating in lipid droplets. Senescing leaves also exhibited an accumulation of sugars including glucose, while nitrogen compounds (nucleobases, nucleotides, and amino acids) decreased. RNA-Seq analysis suggested lipid catabolism via β-oxidation and the glyoxylate cycle, producing carbon skeletons and feeding respiration as a replacement of the diminished carbon supply from photosynthesis. Comparison of the two barley lines highlighted a more prominent up-regulation of heat stress transcription factor- and chaperone-encoding genes in the late-senescing line, suggesting a role for these genes in the control of leaf longevity. While numerous genes with putative roles in nitrogen remobilization were up-regulated in both lines, several peptidases, nucleases, and nitrogen transporters were more highly induced in the early-senescing line; this finding identifies processes and specific candidates which may affect nitrogen remobilization from senescing barley leaves, downstream of the HvNAM1 transcription factor.
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- 2022
10. Who is ‘the user’ of climate services? Unpacking the use of national climate scenarios in Switzerland beyond sectors, numeracy and the research–practice binary
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Maurice Skelton, Andreas M. Fischer, Mark A. Liniger, and David N. Bresch
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Meteorology. Climatology ,QC851-999 ,Social sciences (General) ,H1-99 - Abstract
By whom are national climate scenarios taken up, and which products are used? Despite numerous (national) climate scenarios being published by countries across the globe, studies of their actual uptake and application remain low. Analysing a survey and group interviews on the ways the Swiss climate scenarios CH2011 have been actually used by the Swiss adaptation community, we encoded the emerging differences in a new typology of observers, sailors, and divers. Taking an iceberg as a metaphor for climate scenarios, most respondents were sailors, accessing only key findings above the waterline (i.e., summary brochures). However, the vast majority of climate scenario data remains below the surface (i.e., downscaled climate model data), accessible only to the quarter of respondents labelled divers. Lastly, another quarter are observers, interested in the iceberg from afar, but without applying the climate information directly to their work. By describing three ways of using climate scenarios, we aim to clarify the often vague notion of ‘user’ circulating prominently in discussions around climate services and knowledge co-production. In addition, our results question the adequacy of simplifying climate scenario use by a user’s easily observable characteristics – such as being a researcher or practitioner, by sector or by numeracy. Our typology thus highlights the diversity of use(r)s within sectors or academia, but is also able to characterise various similarities of use(r)s between sectors, researchers and practitioners. Our findings assist in more nuanced and informed discussions of how ‘users’ are imagined and characterised in future developments of usable climate services. Keywords: Climate scenarios, Climate projections, Use of climate science, User characterisation, Tailoring of climate information
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- 2019
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11. Identifying Chinese supply shocks: Effects of trade on labor markets
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Andreas M. Fischer, Philipp Herkenhoff, and Philip Sauré
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Geography, Planning and Development ,Development - Published
- 2023
12. Climate Scenarios and Agricultural Indices: A Case Study for Switzerland
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Flavian Tschurr, Iris Feigenwinter, Andreas M. Fischer, and Sven Kotlarski
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downscaling ,climate indicators ,agriculture ,CH2018 ,climate scenarios ,climate indices ,Meteorology. Climatology ,QC851-999 - Abstract
The CH2018 Climate Scenarios for Switzerland are evaluated with respect to the representation of 24 indices with agricultural relevance. Furthermore, future projections of the considered indices until the end of the 21st century are analyzed for two greenhouse gas scenarios (Representative Concentrations Pathways RCP2.6 and RCP8.5). The validation reveals good results for indices that are based on one or two climate variables only and on simple temporal aggregations. Indices that involve multiple climate variables, complex temporal statistics or extreme conditions are less well represented. The climate projection analysis indicates an intensification of temperature-related extreme events such as heat waves. In general, climate change signals in the indices considered are subject to three main patterns: a horizontal pattern across Switzerland, a vertical pattern depending on elevation and a temporal pattern with an intensification of change in the course of the 21st century. Changes are in most cases more pronounced for the high-emission RCP8.5 scenario compared to the mitigation scenario RCP2.6. Overall, the projections indicate a challenging 21st century climate for the agricultural sector. Our findings furthermore show the value and the necessity of a robust validation of climate scenario products to enable trustworthy and valuable impact analyses, especially for more complex indices and models.
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- 2020
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13. The Swiss Alpine zero degree line: Methods, past evolution and sensitivities
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Andreas M. Fischer, Simon C. Scherrer, Stefanie Gubler, Kathrin Wehrli, and Sven Kotlarski
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Atmospheric Science ,Climatology ,Zero (complex analysis) ,Climate change ,Environmental science ,Line (text file) ,Degree (temperature) - Published
- 2021
14. CNN-based evaluation of bone density improves diagnostic performance to detect osteopenia and osteoporosis in patients with non-contrast chest CT examinations
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Hanns-Christian Breit, Akos Varga-Szemes, U. Joseph Schoepf, Tilman Emrich, Jonathan Aldinger, Reto W. Kressig, Nadine Beerli, Tobias Andreas Buser, Dieter Breil, Ihsan Derani, Stephanie Bridenbaugh, Callum Gill, and Andreas M. Fischer
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Radiology, Nuclear Medicine and imaging ,General Medicine - Published
- 2023
15. Optimization of contrast material administration for coronary CT angiography using a software-based test-bolus evaluation algorithm
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Andreas M Fischer, Josua A. Decker, Joseph Schoepf, Akos Varga-Szemes, Thomas Flohr, Bernhard Schmidt, Ralf Gutjahr, Pooyan Sahbaee, Dante A Giovagnoli, Tilman Emrich, John D Martinez, Kia B Lari, Robert R Bayer, and Simon S Martin
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Computed Tomography Angiography ,Contrast Media ,Humans ,Radiographic Image Interpretation, Computer-Assisted ,Radiology, Nuclear Medicine and imaging ,General Medicine ,Coronary Angiography ,Radiation Dosage ,Algorithms ,Software - Abstract
Objectives: To evaluate the benefit of a prototype circulation time-based test bolus evaluation algorithm for the individualized optimal timing of contrast media (CM) delivery in patients undergoing coronary CT angiography (CCTA). Methods: Thirty-two patients (62 ± 16 years) underwent CCTA using a prototype bolus evaluation tool to determine the optimal time-delay for CM administration. Contrast attenuation, signal-to-noise ratio (SNR), objective, and subjective image quality were evaluated by two independent radiologists. Results were compared to a control cohort (matched for age, sex, body mass index, and tube voltage) of patients who underwent CCTA using the generic test bolus peak attenuation +4 s protocol as scan delay. Results: In the study group, the mean time delay to CCTA acquisition was significantly longer (26.0 ± 2.9 s) compared to the control group (23.1 ± 3.5 s; p < 0.01). In the study group, SNR improvement was seen in the right coronary artery (17.5 vs 13; p = 0.028), the left main (15.3 vs 12.3; p = 0.027), and the left anterior descending artery (18.5 vs 14.1; p = 0.048). Subjective image quality was rated higher in the study group (4.75 ± 0.7 vs 3.64 ± 0.5; p < 0.001). Conclusions: The prototype test bolus evaluation algorithm provided a reliable patient-specific scan delay for CCTA that ensured homogenous vascular attenuation, improvement in objective and subjective image quality, and avoidance of beam hardening artifacts. Advances in knowledge: The prototype contrast bolus evaluation and optimization tool estimated circulation time-based time-delay improves the overall quality of CCTA.
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- 2022
16. Combined effects of a glycine-rich RNA-binding protein and a NAC transcription factor extend grain fill duration and improve malt barley agronomic performance
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Tom Blake, Burcu Alptekin, Dylan Mangel, Duke Pauli, Traci Hoogland, Jamie D. Sherman, Jennifer Lachowiec, and Andreas M. Fischer
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0106 biological sciences ,Germplasm ,Genetics ,food and beverages ,General Medicine ,Biology ,01 natural sciences ,Test weight ,Anthesis ,Genetic linkage ,Gene expression ,Genotype ,Allele ,Agronomy and Crop Science ,Gene ,010606 plant biology & botany ,Biotechnology - Abstract
Two key barley genes independently control anthesis and senescence timing, enabling the manipulation of grain fill duration, grain size/plumpness, and grain protein concentration. Plant developmental processes such as flowering and senescence have direct effects on cereal yield and quality. Previous work highlighted the importance of two tightly linked genes encoding a glycine-rich RNA-binding protein (HvGR-RBP1) and a NAC transcription factor (HvNAM1), controlling barley anthesis timing, senescence, and percent grain protein. Varieties that differ in HvGR-RBP1 expression, ‘Karl’(low) and ‘Lewis’(high), also differ in sequence 1 KB upstream of translation start site, including an ~ 400 bp G rich insertion in the 5′-flanking region of the ‘Karl’ allele, which could disrupt gene expression. To improve malt quality, the (low-grain protein, delayed-senescence) ‘Karl’ HvNAM1 allele was introgressed into Montana germplasm. After several seasons of selection, the resulting germplasm was screened for the allelic combinations of HvGR-RBP1 and HvNAM1, finding lines combining ‘Karl’ alleles for both genes (−/−), lines combining ‘Lewis’ (functional, expressed) HvGR-RBP1 with ‘Karl’ HvNAM1 alleles ( ±), and lines combining ‘Lewis’ alleles for both genes (+ / +). Field experiments indicate that the functional (‘Lewis,’ +) HvGR-RBP1 allele is associated with earlier anthesis and with slightly shorter plants, while the ‘Karl’ (−) HvNAM1 allele delays maturation. Genotypes carrying the ± allele combination therefore had a significantly (3 days) extended grain fill duration, leading to a higher percentage of plump kernels, slightly enhanced test weight, and lower grain protein concentration when compared to the other allele combinations. Overall, our data suggest an important function for HvGR-RBP1 in the control of barley reproductive development and set the stage for a more detailed functional analysis of this gene.
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- 2020
17. Toward Climate-Resilient Development: First Decade with the Global Framework for Climate Services
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Ana E. Bucher, Chris Hewitt, Rupa Kumar Kolli, Barbara Tapia, Ousmane Ndiaye, Erica Allis, Andreas M. Fischer, Meredith Muth, Manola Brunet, Joy Shumake-Guillemot, Simon J. Mason, Angela Michiko Hama, Roger S. Pulwarty, and Filipe Lucio
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Atmospheric Science ,Political science ,Environmental planning ,Climate services - Published
- 2020
18. Making Society Climate Resilient: International Progress under the Global Framework for Climate Services
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Andreas M. Fischer, Meredith Muth, F. Lucio, Manola Brunet, Ousmane Ndiaye, Angela Michiko Hama, Roger S. Pulwarty, Rupa Kumar Kolli, Chris Hewitt, Erica Allis, Barbara Tapia, J. Shumake-Guillemot, Simon J. Mason, and Ana E. Bucher
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0303 health sciences ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Future climate ,USable ,01 natural sciences ,03 medical and health sciences ,Climate change mitigation ,Business ,Socioeconomic status ,Environmental planning ,Climate services ,030304 developmental biology ,0105 earth and related environmental sciences - Abstract
There is growing awareness among governments, businesses, and the general public of risks arising from changes to our climate on time scales from months through to decades. Some climatic changes could be unprecedented in their harmful socioeconomic impacts, while others with adequate forewarning and planning could offer benefits. There is therefore a pressing need for decision-makers, including policy-makers, to have access to and to use high-quality, accessible, relevant, and credible climate information about the past, present, and future to help make better-informed decisions and policies. We refer to the provision and use of such information as climate services. Established programs of research and operational activities are improving observations and climate monitoring, our understanding of climate processes, climate variability and change, and predictions and projections of the future climate. Delivering climate information (including data and knowledge) in a way that is usable and useful for decision-makers has had less attention, and society has yet to optimally benefit from the available information. While weather services routinely help weather-sensitive decision-making, similar services for decisions on longer time scales are less well established. Many organizations are now actively developing climate services, and a growing number of decision-makers are keen to benefit from such services. This article describes progress made over the past decade developing, delivering, and using climate services, in particular from the worldwide effort galvanizing around the Global Framework for Climate Services under the coordination of UN agencies. The article highlights challenges in making further progress and proposes potential new directions to address such challenges.
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- 2020
19. Variability of large-scale atmospheric circulation indices for the northern hemisphere during the past 100 years
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Stefan Brönnimann, Alexander Stickler, Thomas Griesser, Andreas M. Fischer, Andrea Grant, Tracy Ewen, Tianjun Zhou, Martin Schraner, Eugene Rozanov, and Thomas Peter
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Meteorology. Climatology ,QC851-999 - Abstract
We present an analysis of the large-scale atmospheric circulation variability since 1900 based on various circulation indices. They represent the main features of the zonal mean circulation in the northern hemisphere in boreal winter (such as the Hadley circulation, the subtropical jet, and the polar vortex in the lower stratosphere) as well as aspects of the regional and large-scale circulation (the Pacific Walker Circulation, the Indian monsoon, the North Atlantic Oscillation, NAO, and the Pacific North American pattern, PNA). For the past decades we calculate the indices from different reanalyses (NCEP/NCAR, ERA-40, JRA-25, ERA-Interim). For the first half of the 20th century the indices are statistically reconstructed based on historical upper-air and surface data as well as calculated from the Twentieth Century Reanalysis. The indices from all these observation-based data sets are compared to indices calculated from a 9-member ensemble of "all forcings" simulations performed with the chemistry-climate model SOCOL. After discussing the agreement among different data products, we analyse the interannual-to-decadal variability of the indices in the context of possible driving factors, such as El Niño/Southern Oscillation (ENSO), volcanic eruptions, and solar activity. The interannual variability of the Hadley cell strength, the subtropical jet strength, or the PNA is well reproduced by the model ensemble mean, i.e., it is predictable in the context of the specified forcings. The source of this predictability is mainly related to ENSO (or more generally, tropical sea-surface temperatures). For other indices such as the strength of the stratospheric polar vortex, the NAO, or the poleward extent of the Hadley cell the correlations between observations and model ensemble mean are much lower, but so are the correlations within the model ensemble. Multidecadal variability and trends in the individual series are discussed in the context of the underlying anthropogenic and natural forcings. While consistent trends were found for some of the indices, results also indicate that care should be taken when analysing trends in reconstructions or reanalysis data.
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- 2009
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20. The Swiss Alpine zero degree line: methods, past evolution, sensitivities
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Simon C. Scherrer, Stefanie Gubler, Kathrin Wehrli, Andreas M. Fischer, and Sven Kotlarski
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The near-surface zero degree line (ZDL) is a key isotherm in mountain regions worldwide, but a detailed analysis of methods for the ZDL determination, their properties and applicability in a changing climate is missing. We here test different approaches to determine the near-surface ZDL on a monthly scale in the Swiss Alps. A non-linear profile yields more robust and more realistic ZDLs than a linear profile throughout the year and especially in the winter-half year when frequent inversions disqualify a linear assumption. In the period 1871-2019, the Swiss ZDL has risen significantly in every calendar month: In northern Switzerland, the monthly ZDL increases generally amount to 300-400 m with smaller values in April and September (200-250 m) and a larger value in October (almost 500 m). The largest increases of 600-700 m but also very large uncertainties (±400 m, 95% confidence interval) are found in December and January. The trends have accelerated in the last decades especially in spring and summer. The ZDL has increased by ~160 m per °C warming in the summer-half year and up to 340±45 m/°C in winter months. In southern Switzerland, ZDL trends and temperature scalings are somewhat smaller, especially in winter. Sensitivity analyses using a simple shift of the non-linear temperature profile suggest that the winter ZDL-temperature scalings are at a record high today or will reach it in the near future, and are expected to decrease with a strong future warming. Nevertheless, the cumulative ZDL increase for strong warming is considerably larger in winter than in summer. Based on a few key criteria, we also present best practises to determine the ZDL in mountain regions worldwide. The outlined methods lay a foundation for the analysis of further isotherms and to study the future ZDL evolution based on climate scenario data.
- Published
- 2021
21. Future climate data for the building sector
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Kathrin Wehrli, Stefanie Gubler, Andreas M. Fischer, and Sven Kotlarski
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By mid-Century the Swiss Climate Scenarios CH2018 project an additional warming of 2-3 degree Celsius in Switzerland if greenhouse emissions continue unabatedly. In consequence, heatwaves become longer, more intense and more frequent, whereas coldwaves will be less common. Changes in the outdoor climate also affect the indoor climate in buildings where people spend a substantial part of their day to work, study, and live. Buildings are designed to last for several decades with limited possibility to update heating and cooling systems. Hence, the climate a building will face during its lifetime has to be considered in the planning process. In general, it can be expected that the heating demand will decrease whereas the cooling demand will increase in the near future. However, a holistic and quantitative assessment of the effect of climate change on the energy demand in buildings is still missing. For the use in building simulations, climate data at hourly resolution with physical consistency for a number of key variables such as temperature, humidity and radiation are required. To ensure that the use of the data is feasible in practice, the climate of the future needs to be condensed into a single year, representing typical mean conditions as well as typical deviations from the mean. In addition to the typical year, the assessment of an extreme year can provide information on the level of comfort during a once in a lifetime event and the performance at maximum capacity of the installations. Users of this data are practitioners in the building sector as well as officials from federal offices.Our project aims to provide future climate data for the building sector at station level. For this, we make use of observations as well as climate change information from the Swiss climate scenarios CH2018. Together with the users, we define criteria that shall be represented by the future typical and extreme years. We design different methods to create this years based on observations and scenarios and under consideration of existing standards and regulations. The methods are compared in a climatological assessment and sensitivities to emission scenario and time horizon are explored using building simulations. The results of this project support decision-making to optimize national and international norms and regulations and to design adaptation measures. The climate data will be made available to practitioners who can use them to plan the buildings of the future.
- Published
- 2021
22. Effect of Steeping Regime on Barley Malt Quality and Its Impacts on Breeding Program Selection
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Liz Elmore, Dylan Mangel, Jennifer Lachowiec, Jason G. Walling, Jamie D. Sherman, Andreas M. Fischer, and Hannah Turner
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Breeding program ,Starch ,Barley Malt ,media_common.quotation_subject ,Extraction (chemistry) ,Biology ,Applied Microbiology and Biotechnology ,Endosperm ,chemistry.chemical_compound ,chemistry ,Agronomy ,Quality (business) ,Steeping ,Selection (genetic algorithm) ,Food Science ,Biotechnology ,media_common - Abstract
When making malt, the endosperm is hydrated during steeping to make stored starch available for extraction. Differences in steep regime impact malt quality. Differences in malt quality results betw...
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- 2019
23. Tropical circulation and precipitation response to ozone depletion and recovery
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Stefan Brönnimann, Martín Jacques-Coper, Eugene Rozanov, Andreas M Fischer, Olaf Morgenstern, Guang Zeng, Hideharu Akiyoshi, and Yousuke Yamashita
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South Pacific convergence zone ,ozone depletion ,southern annular mode ,chemistry-climate modeling ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 ,Science ,Physics ,QC1-999 - Abstract
Among the few well established changes in atmospheric circulation in recent decades are those caused by stratospheric ozone depletion. They include a strengthening and poleward contraction of the westerly atmospheric circulation over the Southern extratropics, i.e. a strengthening Southern Annular Mode (SAM), in austral spring and summer. Associated effects on extratropical temperature and precipitation and more recently subtropical precipitation have been documented and are understood in a zonal mean framework. We present zonally asymmetric effects of ozone depletion that reach into the tropics and affect atmospheric circulation and precipitation, including the South Pacific Convergence Zone (SPCZ), the most important rainband of the Southern Hemisphere. Using observation-based analyses and model simulations we show that over the 1961–1996 period, ozone depletion led to increased precipitation at the northern flank of the SPCZ and to decreased precipitation to the south. The effects originate from a flow pattern over the southwestern Pacific that extends equatorward and alters the propagation of synoptic waves and thus the position of the SPCZ. Model simulations suggest that anticipated stratospheric ozone recovery over the next decades will reverse these effects.
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- 2017
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24. Non-invasive fractional flow reserve (FFR
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Andreas M, Fischer, Marly, van Assen, U Joseph, Schoepf, Andrew J, Matuskowitz, Akos, Varga-Szemes, Joseph W, Golden, Dante A, Giovagnoli, Christian, Tesche, and Richard R, Bayer
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Adult ,Aged, 80 and over ,Chest Pain ,Adolescent ,Computed Tomography Angiography ,Coronary Artery Disease ,Middle Aged ,Coronary Angiography ,Fractional Flow Reserve, Myocardial ,Young Adult ,Predictive Value of Tests ,Humans ,Aged ,Retrospective Studies - Abstract
To evaluate 30 day rate of major adverse cardiac events (MACE) utilizing cCTA and FFRPatients between the ages of 18-95 years who underwent clinically indicated cCTA and FFRA total of 59 patients underwent CCTA and subsequent FFRIn this limited retrospective study, patients presenting to the ED with acute chest pain and with CCTA with subsequent FFR
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- 2020
25. Evaluating a New Contrast Media Injection System in Coronary CT Angiography
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Simon S, Martin, Dante A, Giovagnoli, Vincenzo, Vingiani, Andres F, Abadia, Andreas M, Fischer, Hubert E, Smith, Elyse M, Wertis, Kelly, Hook, Sandra N, Smith, Tiffany, Wasden, Jenny, Kaminski, Akos, Varga-Szemes, Thomas J, Vogl, and U Joseph, Schoepf
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Adult ,Male ,Computed Tomography Angiography ,Contrast Media ,Humans ,Female ,Coronary Artery Disease ,Middle Aged ,Coronary Angiography ,Tomography, X-Ray Computed ,Aged ,Retrospective Studies - Abstract
To evaluate a new contrast media (CM) injection system in patients undergoing coronary computed tomography angiography (CCTA).Seventy-one consecutive patients (33 men and 38 women, mean age 59.0 ± 14.5 years) who underwent CCTA between February and April 2019 using the CT injection system MEDRAD Stellant FLEX (Bayer) were included retrospectively in this single-center study. Quantitative and qualitative image quality parameters were assessed, and the injection system's usability and operational efficiency were evaluated. Results were compared with a matched control group.All examinations were rated as diagnostic. Usability and operational efficiency of the new injector were rated higher than that of the standard injector system, and no significant differences were found for quantitative and qualitative image quality parameters compared with the control group (Software-based injection facilitates individualized CM application while maintaining high image quality standards in CCTA. Diagnostic accuracy analysis was not performed, but as image quality analysis showed no significant differences, no discrepancies regarding this issue are expected.This study demonstrates that the MEDRAD Stellant FLEX CT injection system allows for consistent high-quality CCTA scanning with increased usability and operational efficiency.
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- 2020
26. CH2018 - National climate scenarios for Switzerland : how to construct consistent multi-model projections from ensembles of opportunity
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Curdin Spirig, Andreas M. Fischer, Silje Lund Sørland, Mark A. Liniger, Jan Rajczak, Christoph Schär, Sven Kotlarski, Reto Knutti, Hans R. Künsch, and Kuno Strassmann
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Atmospheric Science ,010504 meteorology & atmospheric sciences ,Computer science ,media_common.quotation_subject ,0207 environmental engineering ,Regional climate change scenarios ,Climate change ,02 engineering and technology ,lcsh:QC851-999 ,01 natural sciences ,Component (UML) ,Climate service ,Econometrics ,lcsh:Social sciences (General) ,020701 environmental engineering ,0105 earth and related environmental sciences ,media_common ,Climate services ,Regional climate change scenario ,Global and Planetary Change ,363: Umwelt- und Sicherheitsprobleme ,Probabilistic logic ,Ensemble of opportunity ,Uncertainty ,CORDEX ,Ensembles of opportunities ,Switzerland ,General Circulation Model ,lcsh:Meteorology. Climatology ,lcsh:H1-99 ,Climate model ,Construct (philosophy) ,Downscaling - Abstract
The latest Swiss Climate Scenarios (CH2018), released in November 2018, consist of several datasets derived through various methods that provide robust and relevant information on climate change in Switzerland. The scenarios build upon the regional climate model projections for Europe produced through the internationally coordinated downscaling effort EURO-CORDEX. The simulations from EURO-CORDEX consist of simulations at two spatial horizontal resolutions, several global climate models, and three different emission scenarios. Even with this unique dataset of regional climate scenarios, a number of practical challenges regarding a consistent interpretation of the model ensemble arise. Here we present the methodological chain employed in CH2018 in order to generate a multi-model ensemble that is consistent across scenarios and is used as a basis for deriving the CH2018 products. The different steps involve a thorough evaluation of the full EURO-CORDEX model ensemble, the removal of doubtful and potentially erroneous simulations, a time-shift approach to account for an equal number of simulations for each emission scenario, and the multi-model combination of simulations with different spatial resolutions. Each component of this cascade of processing steps is associated with an uncertainty that eventually contributes to the overall scientific uncertainty of the derived scenario products. We present a comparison and an assessment of the uncertainties from these individual effects and relate them to probabilistic projections. It is shown that the CH2018 scenarios are generally supported by the results from other sources. Thus, the CH2018 scenarios currently provide the best available dataset of future climate change estimates in Switzerland., Climate Services, 20, ISSN:2405-8807
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- 2020
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27. The VALUE perfect predictor experiment: Evaluation of temporal variability
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Radan Huth, Andreas M. Fischer, Judit Bartholy, Joaquín Bedia, María Jesús Casado, M. Dubrovsky, Douglas Maraun, Petra Ramos, Rita Pongrácz, Daniel San Martín, Martin Widmann, Elke Hertig, Pedro M. M. Soares, José M. Gutiérrez, Ministry of Education, Youth and Sports (Czech Republic), and European Commission
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Atmospheric Science ,010504 meteorology & atmospheric sciences ,0207 environmental engineering ,02 engineering and technology ,Residual ,01 natural sciences ,Interannual variability ,Validation ,Downscaling ,Bias correction ,Precipitation ,Evaluation ,Regionalclimate ,020701 environmental engineering ,0105 earth and related environmental sciences ,Spells ,Temporal variability ,Long-term trends ,Annual cycle ,Climatology ,Environmental science ,Climate model ,Value (mathematics) ,Quantile - Abstract
Temporal variability is an important feature of climate, comprising systematic variations such as the annual cycle, as well as residual temporal variations such as short-term variations, spells and variability from interannual to long-term trends. The EU-COST Action VALUE developed a comprehensive framework to evaluate downscaling methods. Here we present the evaluation of the perfect predictor experiment for temporal variability. Overall, the behaviour of the different approaches turned out to be as expected from their structure and implementation. The chosen regional climate model adds value to reanalysis data for most considered aspects, for all seasons and for both temperature and precipitation. Bias correction methods do not directly modify temporal variability apart from the annual cycle. However, wet day corrections substantially improve transition probabilities and spell length distributions, whereas interannual variability is in some cases deteriorated by quantile mapping. The performance of perfect prognosis (PP) statistical downscaling methods varies strongly from aspect to aspect and method to method, and depends strongly on the predictor choice. Unconditional weather generators tend to perform well for the aspects they have been calibrated for, but underrepresent long spells and interannual variability. Long-term temperature trends of the driving model are essentially unchanged by bias correction methods. If precipitation trends are not well simulated by the driving model, bias correction further deteriorates these trends. The performance of PP methods to simulate trends depends strongly on the chosen predictors., EU COST Association, Grant/Award Number: ES1102; Ministry of Education, Youth, and Sports of the Czech Republic, Grant/AwardNumber:LD12029
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- 2017
28. A fully automated software platform for structural mitral valve analysis
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Robert, Steinbach, U Joseph, Schoepf, L Parkwood, Griffith, Marly, van Assen, Matthias, Renker, Pooyan, Sahbaee, Chris, Schwemmer, Andreas M, Fischer, Akos, Varga-Szemes, Simon S, Martin, and Richard R, Bayer
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Aged, 80 and over ,Heart Valve Prosthesis Implantation ,Male ,Reproducibility of Results ,Middle Aged ,Pattern Recognition, Automated ,Predictive Value of Tests ,Image Processing, Computer-Assisted ,Humans ,Mitral Valve ,Female ,Tomography, X-Ray Computed ,Software ,Aged ,Retrospective Studies - Abstract
To evaluate a novel fully automated mitral valve analysis software platform for cardiac computer tomography angiography (CCTA)-based structural heart therapy procedure planning.The study included 52 patients (25 women; mean age, 66.9 ± 12.4 years) who had undergone CCTA prior to transcatheter mitral valve replacement (TMVR) or surgical mitral valve intervention (replacement or repair). Therapeutically relevant mitral valve annulus parameters (projected area, circumference, trigone-to-trigone (T-T) distance, anterior-posterior (AP) diameter, and anterolateral-posteromedial (AL-PM) diameter) were measured. Results of the fully automated mitral valve analysis software platform with and without manual adjustments were compared with the reference standard of a user-driven measurement program (3mensio, Pie Medical Imaging). Measurements were compared between the fully automated software, both with and without manual adjustment, and the user-driven program using intraclass correlation coefficients (ICC). A secondary analysis included the time to obtain all measurements.Fully automated measurements showed a good to excellent agreement (circumference, ICC = 0.70; projected area, ICC = 0.81; T-T distance, ICC = 0.64; AP, ICC = 0.62; and AL-PM diameter, ICC = 0.78) compared with the user-driven analysis. There was an excellent agreement between fully automated measurement with manual adjustments and user-driven analysis regarding circumference (ICC = 0.91), projected area (ICC = 0.93), T-T distance (ICC = 0.80), AP (ICC = 0.78), and AL-PM diameter (ICC = 0.79). The time required for mitral valve analysis was significantly lower using the fully automated software with manual adjustments compared with the standard assessment (134.4 ± 36.4 s vs. 304.3 ± 77.7 s) (p0.01).The fully automated mitral valve analysis software, when combined with manual adjustments, demonstrated a strong correlation compared with the user-driven software while reducing the total time required for measurement.• The novel software platform allows for a fully automated analysis of mitral valve structures. • An excellent agreement was found between the fully automated measurement with manual adjustments and the user-driven analysis. • The software showed quicker measurement time compared with the standard analysis of the mitral valve.
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- 2019
29. Who is ‘the user’ of climate services? Unpacking the use of national climate scenarios in Switzerland beyond sectors, numeracy and the research–practice binary
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David N. Bresch, Mark A. Liniger, Andreas M. Fischer, and Maurice Skelton
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Typology ,Atmospheric Science ,climate projections ,010504 meteorology & atmospheric sciences ,Metaphor ,media_common.quotation_subject ,0207 environmental engineering ,Globe ,02 engineering and technology ,lcsh:QC851-999 ,use of climate science ,01 natural sciences ,Numeracy ,Political science ,medicine ,climate scenarios ,user characterisation ,tailoring of climate information ,lcsh:Social sciences (General) ,020701 environmental engineering ,Adaptation (computer science) ,0105 earth and related environmental sciences ,media_common ,Global and Planetary Change ,business.industry ,Public relations ,Quarter (United States coin) ,medicine.anatomical_structure ,lcsh:Meteorology. Climatology ,lcsh:H1-99 ,Climate model ,business ,Diversity (politics) - Abstract
By whom are national climate scenarios taken up, and which products are used? Despite numerous (national) climate scenarios being published by countries across the globe, studies of their actual uptake and application remain low. Analysing a survey and group interviews on the ways the Swiss climate scenarios CH2011 have been actually used by the Swiss adaptation community, we encoded the emerging differences in a new typology of observers, sailors, and divers. Taking an iceberg as a metaphor for climate scenarios, most respondents were sailors, accessing only key findings above the waterline (i.e., summary brochures). However, the vast majority of climate scenario data remains below the surface (i.e., downscaled climate model data), accessible only to the quarter of respondents labelled divers. Lastly, another quarter are observers, interested in the iceberg from afar, but without applying the climate information directly to their work. By describing three ways of using climate scenarios, we aim to clarify the often vague notion of ‘user’ circulating prominently in discussions around climate services and knowledge co-production. In addition, our results question the adequacy of simplifying climate scenario use by a user’s easily observable characteristics – such as being a researcher or practitioner, by sector or by numeracy. Our typology thus highlights the diversity of use(r)s within sectors or academia, but is also able to characterise various similarities of use(r)s between sectors, researchers and practitioners. Our findings assist in more nuanced and informed discussions of how ‘users’ are imagined and characterised in future developments of usable climate services., Climate Services, 15, ISSN:2405-8807
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- 2019
30. Supplementary material to 'Climate projections of a multi-variate heat stress index: the role of downscaling and bias correction'
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Ana Casanueva, Sven Kotlarski, Sixto Herrera, Andreas M. Fischer, Tord Kjellstrom, and Cornelia Schwierz
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- 2019
31. Evaluating the added value of the new Swiss climate scenarios for hydrology: An example from the Thur catchment
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Andreas M. Fischer, Rolf Weingartner, Sven Kotlarski, Ole Rössler, Denise Keller, and Mark A. Liniger
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Atmospheric Science ,Global and Planetary Change ,Forcing (recursion theory) ,010504 meteorology & atmospheric sciences ,0207 environmental engineering ,Climate change ,02 engineering and technology ,910 Geography & travel ,lcsh:QC851-999 ,01 natural sciences ,Variable (computer science) ,Greenhouse gas ,Climatology ,Added value ,Environmental science ,Climate model ,lcsh:Meteorology. Climatology ,lcsh:H1-99 ,lcsh:Social sciences (General) ,020701 environmental engineering ,Projection (set theory) ,0105 earth and related environmental sciences ,Quantile - Abstract
The availability of new climate greenhouse gas scenario data often prompts the question in what respect the new data provide added value with respect to previous versions and whether or not impact models have to be rerun with the new climatic forcing. This question is the case not only for updated sets of underlying climate model ensembles but also for changes in the applied postprocessing method, such as in the upcoming new climate change projection suite CH2018. The new local projection data are no longer post-processed based on the delta change approach but using quantile mapping. Here, we evaluate the added value of new climate projections from a hydrological perspective. We propose an evaluation scheme that comprises both reference and greenhouse gas scenario periods, average values on different temporal aggregation levels, as well as extreme-related multiday indices. For a test catchment (Thur, pre-alpine, 1700 km2) we show that the question about an added value, strongly depends on the variable and aspect (average and extreme) of interest. In many cases, basic hydrological characteristics are similarly represented when employing different climate model postprocessing techniques. However, we found differences in the climate change signal already for mean monthly runoff values and even more for several extreme-related indices. Some of them reveal very similar change signals, while the indices related to the intensity/volume of the extremes can strongly diverge. We argue that the comprehensive comparative analysis presented here is transferable and provides useful guidance for the assessment an added value, especially for climate data providers and impact modellers., Climate Services, 13, ISSN:2405-8807
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- 2019
32. An intercomparison of a large ensemble of statistical downscaling methods over Europe: Results from the VALUE perfect predictor cross-validation experiment
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Damien Raynaud, Andreas M. Fischer, Petr Štěpánek, Rita M. Cardoso, Joaquín Bedia, Douglas Maraun, Javier Pórtoles, Ana Casanueva, Benoit Hingray, Bartosz Czernecki, D. San Martín, Rodrigo Manzanas, Rasmus E. Benestad, Joanna Wibig, Sixto Herrera, María Jesús Casado, Sven Kotlarski, Olle Räty, M. Dubrovsky, O. Roessler, Petra Ramos, Judit Bartholy, Elke Hertig, Marco Turco, Thomas Bosshard, José M. Gutiérrez, Tanja Zerenner, Jouni Räisänen, Denise Keller, Mathieu Vrac, Maialen Iturbide, Radan Huth, Rita Pongrácz, Renate Wilcke, Christian Pagé, Pedro M. M. Soares, Jaime Ribalaygua, Martin Widmann, Institute for Atmospheric and Earth System Research (INAR), Wegener Center for Climate and Global Change, University of Graz, Institute of Atmospheric Physics [Prague] (IAP), Czech Academy of Sciences [Prague] (ASCR), Norwegian Meteorological Institute, Max-Planck-Institut für Meteorologie (MPI-M), Max-Planck-Gesellschaft, Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Departament de Fisica Teorica, IFIC, CSIC, Universitat de València (UV), Department of Physics [Helsinki], Falculty of Science [Helsinki], University of Helsinki-University of Helsinki, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Earth Sciences Department [Barcelona], Barcelona Supercomputing Center - Centro Nacional de Supercomputacion (BSC - CNS), Department of Meteorology [Budapest], Institute of Geography and Earth Sciences [Budapest], Faculty of Sciences [Budapest], Eötvös Loránd University (ELTE)-Eötvös Loránd University (ELTE)-Faculty of Sciences [Budapest], Eötvös Loránd University (ELTE)-Eötvös Loránd University (ELTE), Laboratoire de Probabilités et Modèles Aléatoires (LPMA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), European Commission, Ministerio de Economía y Competitividad (España), Ministry of Education, Youth and Sports (Czech Republic), Wegener Center for Climate and Global Change (WEGC), Karl-Franzens-Universität [Graz, Autriche], Czech Academy of Sciences [Prague] (CAS), Norwegian Meteorological Institute [Oslo] (MET), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Extrèmes : Statistiques, Impacts et Régionalisation (ESTIMR), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut de Recherche pour le Développement (IRD)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire de Probabilités, Statistiques et Modélisations (LPSM (UMR_8001)), Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Karl-Franzens-Universität Graz, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, and Laboratoire de Probabilités, Statistique et Modélisation (LPSM (UMR_8001))
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1171 Geosciences ,Atmospheric Science ,CLIMATE-CHANGE PROJECTIONS ,010504 meteorology & atmospheric sciences ,BIAS CORRECTION ,weather generators ,perfect prognosis ,0207 environmental engineering ,DAILY TEMPERATURE ,02 engineering and technology ,MODEL OUTPUT ,bias adjustment ,01 natural sciences ,114 Physical sciences ,Cross-validation ,model output statistics ,Validation ,Downscaling ,Bias correction ,FUTURE CLIMATE ,020701 environmental engineering ,reproducibility ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Mathematics ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,validation ,Reproducibility ,Weather gen33 erators ,downscaling ,Future climate ,FRAMEWORK ,SCENARIOS ,Perfect prognosis ,Weather generators ,DAILY PRECIPITATION ,Model output statistics ,Bias adjustment ,CORDEX ,13. Climate action ,[SDU]Sciences of the Universe [physics] ,Climatology ,Value (mathematics) ,[STAT.ME]Statistics [stat]/Methodology [stat.ME] - Abstract
Special Issue: VALUE: Validating and Integrating Downscaling Methods for Climate Change Research: et al., VALUE is an open European collaboration to intercompare downscaling approaches for climate change research, focusing on different validation aspects (marginal, temporal, extremes, spatial, process-based, etc.). Here we describe the participating methods and first results from the first experiment, using “perfect” reanalysis (and reanalysis-driven regional climate model (RCM)) predictors to assess the intrinsic performance of the methods for downscaling precipitation and temperatures over a set of 86 stations representative of the main climatic regions in Europe. This study constitutes the largest and most comprehensive to date intercomparison of statistical downscaling methods, covering the three common downscaling approaches (perfect prognosis, model output statistics—including bias correction—and weather generators) with a total of over 50 downscaling methods representative of the most common techniques. Overall, most of the downscaling methods greatly improve (reanalysis or RCM) raw model biases and no approach or technique seems to be superior in general, because there is a large method-to-method variability. The main factors most influencing the results are the seasonal calibration of the methods (e.g., using a moving window) and their stochastic nature. The particular predictors used also play an important role in cases where the comparison was possible, both for the validation results and for the strength of the predictor–predictand link, indicating the local variability explained. However, the present study cannot give a conclusive assessment of the skill of the methods to simulate regional future climates, and further experiments will be soon performed in the framework of the EURO-CORDEX initiative (where VALUE activities have merged and follow on). Finally, research transparency and reproducibility has been a major concern and substantive steps have been taken. In particular, the necessary data to run the experiments are provided at http://www.value-cost.eu/data and data and validation results are available from the VALUE validation portal for further investigation: http://www.value-cost.eu/validationportal., This work has been performed in the framework of the VALUE COST Action ES1102, under FP7 programme J.M.G. and S.H. acknowledge partial funding from MULTI-SDM project (MINECO/FEDER, CGL2015-66583-R). B.H. and D.R. acknowledge COMPLEX project (FP7-ENV-2012, No: 308601). M.T. was supported by HOPE project (MINECO, CGL2014-52571-R). Participation of M.D., P.S. and R.H. was funded by the Ministry of Education, Youth, and Sports of the Czech Republic contracts LD12029, LD14043 and LD12059, respectively.
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- 2019
33. Validation of spatial variability in downscaling results from the VALUE perfect predictor experiment
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Radan Huth, María Jesús Casado, José M. Gutiérrez, Petra Ramos, Thomas Bosshard, Andreas M. Fischer, Joaquín Bedia, Jamie Ribalaygua, Rita M. Cardoso, Pedro M. M. Soares, Sixto Herrera, Douglas Maraun, Christian Pagé, Martin Widmann, Elke Hertig, European Commission, and Universidad de Cantabria
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Atmospheric Science ,Regional climate ,010504 meteorology & atmospheric sciences ,0207 environmental engineering ,02 engineering and technology ,01 natural sciences ,Perfect prognosis ,Model output statistics ,Spatialvariability ,Bias adjustment ,Hydrology (agriculture) ,Climatology ,Validation ,Downscaling ,Spatial variability ,020701 environmental engineering ,Value (mathematics) ,0105 earth and related environmental sciences ,Mathematics - Abstract
The spatial dependence of meteorological variables is crucial for many impacts, for example, droughts, floods, river flows, energy demand, and crop yield. There is thus a need to understand how well it is represented in downscaling (DS) products. Within the COST Action VALUE, we have conducted a comprehensive analysis of spatial variability in the output of over 40 different DS methods in a perfect predictor setup. The DS output is evaluated against daily precipitation and temperature observations for the period 1979–2008 at 86 sites across Europe and 53 sites across Germany. We have analysed the dependency of correlations of daily temperature and precipitation series at station pairs on the distance between the stations. For the European data set, we have also investigated the complexity of the downscaled data by calculating the number of independent spatial degrees of freedom. For daily precipitation at the German network, we have additionally evaluated the dependency of the joint exceedance of the wet day threshold and of the local 90th percentile on the distance between the stations. Finally, we have investigated regional patterns of European monthly precipitation obtained from rotated principal component analysis. We analysed Perfect Prog (PP) methods, which are based on statistical relationships derived from observations, as well as Model Output Statistics (MOS) approaches, which attempt to correct simulated variables. In summary, we found that most PP DS methods, with the exception of multisite analog methods and a method that explicitly models spatial dependence yield unrealistic spatial characteristics. Regional climate model-based MOS methods showed good performance with respect to correlation lengths and the joint occurrence of wet days, but a substantial overestimation of the joint occurrence of heavy precipitation events. These findings apply to the spatial scales that are resolved by our observation network, and similar studies with higher resolutions, which are relevant for small hydrological catchment, are desirable., EU, Grant/Award Number: EU COST Action ES1102.
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- 2019
34. The Future of Climate Services
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Universitat Rovira i Virgili, Allis Erica, Chris D. Hewitt, Ousmane Ndiaye, Angela Michiko Hama, Andreas M. Fischer, Ana Bucher, Akihiko Shimpo, Roger Pulwarty, Simon Mason, Manola Brunet, Barbara Tapia, Universitat Rovira i Virgili, and Allis Erica, Chris D. Hewitt, Ousmane Ndiaye, Angela Michiko Hama, Andreas M. Fischer, Ana Bucher, Akihiko Shimpo, Roger Pulwarty, Simon Mason, Manola Brunet, Barbara Tapia
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- 2019
35. Testing a weather generator for downscaling climate change projections over Switzerland
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Andreas M. Fischer, Mark A. Liniger, Christof Appenzeller, Reto Knutti, and Denise Keller
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,Meteorology ,0208 environmental biotechnology ,Mode (statistics) ,Climate change ,02 engineering and technology ,Reference Period ,Snow ,01 natural sciences ,020801 environmental engineering ,Climatology ,Environmental science ,Climate model ,Precipitation ,Mean radiant temperature ,0105 earth and related environmental sciences ,Downscaling - Abstract
Climate information provided by global or regional climate models (RCMs) are often too coarse and prone to substantial biases for local assessments or use in impact models. Hence, statistical downscaling becomes necessary. For the Swiss National Climate Change Initiative (CH2011), a delta-change approach was used to provide daily climate scenarios at the local scale. Here, we analyse a Richardson-type weather generator (WG) as an alternative method to downscale daily precipitation, minimum and maximum temperature. The WG is calibrated for 26 Swiss stations and the reference period is 1980–2009. It is perturbed with change factors derived from RCMs (ENSEMBLES) to represent the climate of 2070–2099 assuming the SRES A1B emission scenario. The WG can be run in multi-site mode, making it especially attractive for impact-modellers that rely on a realistic spatial structure in downscaled time-series. The results from the WG are benchmarked against the original delta-change approach that applies mean additive or multiplicative adjustments to the observations. According to both downscaling methods, the results reveal mean temperature increases and a precipitation decrease in summer, consistent with earlier studies. For the summer drying, the WG indicates primarily a decrease in wet-day frequency and correspondingly an increase in mean dry spell length of between 18 and 40% at low-elevation stations. By definition, these potential changes cannot be represented by a delta-change approach. In winter, both methods project a shortening of the frost period (−30 to −60 days) and a decrease of snow days (−20 to −100%). The WG demonstrates though, that almost present-day conditions in snow-days could still occur in the future. As expected, both methods have difficulties in representing extremes. If users focus on changes in temporal sequences and need a large number of future realizations, it is recommended to use data from a WG instead of a delta-change approach.
- Published
- 2016
36. Southward shift of the northern tropical belt from 1945 to 1980
- Author
-
Paul Poli, Eugene Rozanov, Gilbert P. Compo, Andreas M. Fischer, Stefan Brönnimann, and Prashant D. Sardeshmukh
- Subjects
13. Climate action ,Climatology ,General Earth and Planetary Sciences ,Climate change ,Environmental science ,Tropical rain belt ,Atmospheric dynamics ,Subtropics ,Atmospheric sciences ,Tropical rainforest climate - Abstract
The width of the tropical belt affects the subtropical dry zones and has expanded since 1980. Analyses of observations and climate–chemistry model simulations suggest that the northern tropical edge retracted between 1945 and 1980.
- Published
- 2015
37. Implementation and validation of a Wilks-type multi-site daily precipitation generator over a typical Alpine river catchment
- Author
-
Mark A. Liniger, Reto Knutti, Christof Appenzeller, Christoph Frei, Andreas M. Fischer, and Denise Keller
- Subjects
lcsh:GE1-350 ,Quantitative precipitation estimation ,lcsh:T ,Stochastic process ,lcsh:Geography. Anthropology. Recreation ,Climate change ,STREAMS ,Annual cycle ,lcsh:Technology ,lcsh:TD1-1066 ,Current (stream) ,lcsh:G ,Climatology ,Environmental science ,Precipitation ,lcsh:Environmental technology. Sanitary engineering ,lcsh:Environmental sciences ,Downscaling - Abstract
Many climate impact assessments require high-resolution precipitation time series that have a spatio-temporal correlation structure consistent with observations, for simulating either current or future climate conditions. In this respect, weather generators (WGs) designed and calibrated for multiple sites are an appealing statistical downscaling technique to stochastically simulate multiple realisations of possible future time series consistent with the local precipitation characteristics and their expected future changes. In this study, we present the implementation and validation of a multi-site daily precipitation generator re-built after the methodology described in Wilks (1998). The generator consists of several Richardson-type WGs run with spatially correlated random number streams. This study aims at investigating the capabilities, the added value and the limitations of the precipitation generator for a typical Alpine river catchment in the Swiss Alpine region under current climate. The calibrated multi-site WG is skilful at individual sites in representing the annual cycle of the precipitation statistics, such as mean wet day frequency and intensity as well as monthly precipitation sums. It reproduces realistically the multi-day statistics such as the frequencies of dry and wet spell lengths and precipitation sums over consecutive wet days. Substantial added value is demonstrated in simulating daily areal precipitation sums in comparison to multiple WGs that lack the spatial dependency in the stochastic process. Limitations are seen in reproducing daily and multi-day extreme precipitation sums, observed variability from year to year and in reproducing long dry spell lengths. Given the performance of the presented generator, we conclude that it is a useful tool to generate precipitation series consistent with the mean climatic aspects and likely helpful to be used as a downscaling technique for climate change scenarios., Hydrology and Earth System Sciences, 19 (5), ISSN:1027-5606, ISSN:1607-7938
- Published
- 2015
38. Structural and Biochemical Analysis of the Hordeum vulgare L. HvGR-RBP1 Protein, a Glycine-Rich RNA-Binding Protein Involved in the Regulation of Barley Plant Development and Stress Response
- Author
-
Paul S. Powell, Valérie Copié, Brian J. Eilers, Katelyn E. Mason, Brian P. Tripet, Andreas M. Fischer, and Jennifer Burns
- Subjects
2. Zero hunger ,DNA, Plant ,RNA recognition motif ,Cold-Shock Response ,fungi ,DNA, Single-Stranded ,RNA-Binding Proteins ,food and beverages ,Hordeum ,RNA-binding protein ,Biology ,Biochemistry ,Article ,Protein Structure, Tertiary ,RNA, Plant ,Gene expression ,Nucleic acid ,biology.protein ,Hordeum vulgare ,Protein A ,RBP1 ,Heteronuclear single quantum coherence spectroscopy ,Plant Proteins ,Protein Binding - Abstract
The timing of whole-plant senescence influences important agricultural traits such as yield and grain protein content. Post-transcriptional regulation by plant RNA-binding proteins is essential for proper control of gene expression, development, and stress responses. Here, we report the three-dimensional solution NMR structure and nucleic acid-binding properties of the barley glycine-rich RNA-binding protein HvGR-RBP1, whose transcript has been identified as being45-fold up-regulated in early-as compared to late-senescing near-isogenic barley germplasm. NMR analysis reveals that HvGR-RBP1 is a multidomain protein comprising a well-folded N-terminal RNA Recognition Motif (RRM) and a structurally disordered C-terminal glycine-rich domain. Chemical shift differences observed in 2D (1)H-(15)N correlation (HSQC) NMR spectra of full-length HvGR-RBP1 and N-HvGR-RBP1 (RRM domain only) suggest that the two domains can interact both in-trans and intramolecularly, similar to what is observed in the tobacco NtGR-RBP1 protein. Further, we show that the RRM domain of HvGR-RBP1 binds single-stranded DNA nucleotide fragments containing the consensus nucleotide sequence 5'-TTCTGX-3' with low micromolar affinity in vitro. We also demonstrate that the C-terminal glycine-rich (HvGR) domain of Hv-GR-RBP1 can interact nonspecifically with ssRNA in vitro. Structural similarities with other plant glycine-rich RNA-binding proteins suggest that HvGR-RBP1 may be multifunctional. Based on gene expression analysis following cold stress in barley and E. coli growth studies following cold shock treatment, we conclude that HvGR-RBP1 functions in a manner similar to cold-shock proteins and harbors RNA chaperone activity. HvGR-RBP1 is therefore not only involved in the regulation of barley development including senescence, but also functions in plant responses to environmental stress.
- Published
- 2014
39. Projected changes in precipitation intensity and frequency in Switzerland: a multi-model perspective
- Author
-
Andreas M. Fischer, Christoph Schär, Mark A. Liniger, Denise Keller, Jan Rajczak, and C. Appenzeller
- Subjects
Atmospheric Science ,010504 meteorology & atmospheric sciences ,0207 environmental engineering ,Climate change ,Dry spell ,02 engineering and technology ,15. Life on land ,Atmospheric sciences ,01 natural sciences ,13. Climate action ,Climatology ,Environmental science ,Climate model ,Precipitation ,Climate change adaptation ,Water cycle ,020701 environmental engineering ,Intensity (heat transfer) ,0105 earth and related environmental sciences ,Convective precipitation - Abstract
Fundamental changes in the hydrological cycle are to be expected in a future warmer climate. For Switzerland, recent climate change assessments based on the ENSEMBLES regional climate models project for the A1B emission scenario summer mean precipitation to significantly decrease by the end of this century, whereas winter mean precipitation tend to rise in Southern Switzerland. From an end-user perspective, projected changes in seasonal means are often insufficient to adequately address the multifaceted challenges of climate change adaptation. In this study, we investigate the projected changes in seasonal precipitation by considering changes in frequency and intensity, precipitation type (convective vs stratiform) and temporal structure (wet and dry spells) over Switzerland. As proxies for rain-type changes, we rely on the parameterized convective and large-scale precipitation components simulated by the models. The study reveals that the projected summer drying over Switzerland at the end of the century is mainly driven by a widespread reduction in the number of precipitation days. Thereby, the drying evolves altitude-specific: over low-land regions it is associated with a decrease in both convective and large-scale precipitation. Over elevated regions it is primarily associated with a decline in large-scale precipitation only, whereas convective precipitation remains at current levels. As a consequence, almost all the models project an increase in convective fraction at elevated altitudes. The decrease in the number of wet days during summer is accompanied by decreases (increases) in the number of multi-day wet (dry) spells. This future shift in multi-day episodes also lowers down the likelihood of short dry spell occurrence in all of the models. The models further project a higher mean precipitation intensity in spring and autumn north of the Alps, whereas a similar tendency is expected for the winter season over most of Switzerland.
- Published
- 2014
40. Localized climate change scenarios of mean temperature and precipitation over Switzerland
- Author
-
Simon C. Scherrer, Mark A. Liniger, Andreas M. Fischer, Elias Zubler, Mischa Croci-Maspoli, and Christof Appenzeller
- Subjects
Atmospheric Science ,Global and Planetary Change ,Kriging ,Climatology ,Climate change scenario ,Environmental science ,Climate change ,Climate model ,Precipitation ,Mean radiant temperature ,Lead time ,Downscaling - Abstract
There is a growing need of the climate change impact modeling and adaptation community to have more localized climate change scenario information available over complex topography such as in Switzerland. A gridded dataset of expected future climate change signals for seasonal averages of daily mean temperature and precipitation in Switzerland is presented. The basic scenarios are taken from the CH2011 initiative. In CH2011, a Bayesian framework was applied to obtain probabilistic scenarios for three regions within Switzerland. Here, the results for two additional Alpine sub-regions are presented. The regional estimates have then been downscaled onto a regular latitude-longitude grid with a resolution of 0.02° or roughly 2 km. The downscaling procedure is based on the spatial structure of the climate change signals as simulated by the underlying regional climate models and relies on a Kriging with external drift using height as auxiliary predictor. The considered emission scenarios are A1B, A2 and the mitigation scenario RCP3PD. The new dataset shows an expected warming of about 1 to 6 °C until the end of the 21st century, strongly depending on the scenario and the lead time. Owing to a large vertical gradient, the warming is about 1 °C stronger in the Alps than in the Swiss lowlands. In case of precipitation, the projection uncertainty is large and in most seasons precipitation can increase or decrease. In summer a distinct decrease of precipitation can be found, again strongly depending on the emission scenario.
- Published
- 2014
41. Senescence, nutrient remobilization, and yield in wheat and barley
- Author
-
Raz Avni, Assaf Distelfeld, and Andreas M. Fischer
- Subjects
Crops, Agricultural ,Senescence ,Nitrogen ,Physiology ,Membrane transport protein ,food and beverages ,Hordeum ,Monocarpic ,Plant Science ,Biology ,Protein degradation ,Endosperm ,Plant Leaves ,Nutrient ,Agronomy ,Botany ,biology.protein ,Gene ,Nitrogen cycle ,Triticum ,Plant Proteins - Abstract
Cereals including wheat and barley are of primary importance to ensure food security for the 21st century. A combination of lab- and field-based approaches has led to a considerably improved understanding of the importance of organ and particularly of whole-plant (monocarpic) senescence for wheat and barley yield and quality. A delicate balance between senescence timing, grain nutrient content, nutrient-use efficiency, and yield needs to be considered to (further) improve cereal varieties for a given environment and end use. The recent characterization of the Gpc-1 (NAM-1) genes in wheat and barley demonstrates the interdependence of these traits. Lines or varieties with functional Gpc-1 genes demonstrate earlier senescence and enhanced grain protein and micronutrient content but, depending on the environment, somewhat reduced yields. A major effort is needed to dissect regulatory networks centred on additional wheat and barley transcription factors and signalling pathways influencing the senescence process. Similarly, while important molecular details of nutrient (particularly nitrogen) remobilization from senescing organs to developing grains have been identified, important knowledge gaps remain. The genes coding for the major proteases involved in senescence-associated plastidial protein degradation are largely unknown. Membrane transport proteins involved in the different transport steps occurring between senescing organ (such as leaf mesophyll) cells and protein bodies in the endosperm of developing grains remain to be identified or further characterized. Existing data suggest that an improved understanding of all these steps will reveal additional, important targets for continued cereal improvement.
- Published
- 2014
42. De nouveaux scénarios climatiques pour la Suisse
- Author
-
Isabelle Bey, Andreas M. Fischer, Angela Michiko Hama, and Sonia I. Seneviratne
- Published
- 2019
43. 1H, 13C, 15N backbone and side chain NMR resonance assignments for the N-terminal RNA recognition motif of the HvGR-RBP1 protein involved in the regulation of barley (Hordeum vulgare L.) senescence
- Author
-
Valérie Copié, Andreas M. Fischer, Katelyn E. Mason, David L. Parrott, and Brian P. Tripet
- Subjects
Plant senescence ,Senescence ,RNA recognition motif ,Biochemistry ,Structural Biology ,food and beverages ,RNA-binding protein ,Protein structure function ,Hordeum vulgare ,Biology ,Gene ,Peptide sequence - Abstract
Leaf senescence is an important process in the developmental life of all plant species. Senescence efficiency influences important agricultural traits such as grain protein content and plant growth, which are often limited by nitrogen use. Little is known about the molecular mechanisms regulating this highly orchestrated process. To enhance our understanding of leaf senescence and its regulation, we have undertaken the structural and functional characterization of previously unknown proteins that are involved in the control of senescence in barley (Hordeum vulgare L.). Previous microarray analysis highlighted several barley genes whose transcripts are differentially expressed during senescence, including a specific gene which is greater than 40-fold up-regulated in the flag leaves of early- as compared to late-senescing near-isogenic barley lines at 14 and 21 days past flowering (anthesis). From inspection of its amino acid sequence, this gene is predicted to encode a glycine-rich RNA-binding protein herein referred to as HvGR-RBP1. HvGR-RBP1 has been expressed as a recombinant protein in Escherichia coli, and preliminary NMR data analysis has revealed that its glycine-rich C-terminal region [residues: 93–162] is structurally disordered whereas its N-terminal region [residues: 1–92] forms a well-folded domain. Herein, we report the complete 1H, 13C, and 15N resonance assignments of backbone and sidechain atoms, and the secondary structural topology of the N-terminal RNA recognition motif (RRM) domain of HvGR-RBP1, as a first step to unraveling its structural and functional role in the regulation of barley leaf senescence.
- Published
- 2013
44. A global historical ozone data set and prominent features of stratospheric variability prior to 1979
- Author
-
René Bleisch, Birgit Hassler, Simon Flückiger, Eugene Rozanov, Andreas M. Fischer, Greg Bodeker, Jörg Franke, M. Schraner, Jonas Bhend, and Stefan Brönnimann
- Subjects
Atmospheric Science ,Ozone ,010504 meteorology & atmospheric sciences ,530 Physics ,Atmospheric circulation ,010502 geochemistry & geophysics ,Atmospheric sciences ,01 natural sciences ,lcsh:Chemistry ,chemistry.chemical_compound ,Data assimilation ,Ozone layer ,Tropospheric ozone ,910 Geography & travel ,0105 earth and related environmental sciences ,500 Science ,lcsh:QC1-999 ,Solar cycle ,lcsh:QD1-999 ,chemistry ,13. Climate action ,Climatology ,Greenhouse gas ,Environmental science ,Satellite ,lcsh:Physics - Abstract
We present a vertically resolved zonal mean monthly mean global ozone data set spanning the period 1901 to 2007, called HISTOZ.1.0. It is based on a new approach that combines information from an ensemble of chemistry climate model (CCM) simulations with historical total column ozone information. The CCM simulations incorporate important external drivers of stratospheric chemistry and dynamics (in particular solar and volcanic effects, greenhouse gases and ozone depleting substances, sea surface temperatures, and the quasi-biennial oscillation). The historical total column ozone observations include ground-based measurements from the 1920s onward and satellite observations from 1970 to 1976. An off-line data assimilation approach is used to combine model simulations, observations, and information on the observation error. The period starting in 1979 was used for validation with existing ozone data sets and therefore only ground-based measurements were assimilated. Results demonstrate considerable skill from the CCM simulations alone. Assimilating observations provides additional skill for total column ozone. With respect to the vertical ozone distribution, assimilating observations increases on average the correlation with a reference data set, but does not decrease the mean squared error. Analyses of HISTOZ.1.0 with respect to the effects of El Niño–Southern Oscillation (ENSO) and of the 11 yr solar cycle on stratospheric ozone from 1934 to 1979 qualitatively confirm previous studies that focussed on the post-1979 period. The ENSO signature exhibits a much clearer imprint of a change in strength of the Brewer–Dobson circulation compared to the post-1979 period. The imprint of the 11 yr solar cycle is slightly weaker in the earlier period. Furthermore, the total column ozone increase from the 1950s to around 1970 at northern mid-latitudes is briefly discussed. Indications for contributions of a tropospheric ozone increase, greenhouse gases, and changes in atmospheric circulation are found. Finally, the paper points at several possible future improvements of HISTOZ.1.0.
- Published
- 2013
45. Terrorists Among Us
- Author
-
Margit E. Oswald, Andreas M. Fischer, and Stefan Seiler
- Subjects
Retributive justice ,Group membership ,Vignette ,300 Social sciences, sociology & anthropology ,Terrorism ,Sample (statistics) ,Suspect ,Psychology ,Interrogation ,Social psychology ,General Psychology - Abstract
Support among US citizens for severe interrogation has been recognized as drawing upon utilitarian as well as on retributive motivation ( Carlsmith & Sood, 2009 ). Two studies were conducted to expand on these findings in a Swiss sample. In Study 1, participants rated the severity of different interrogation techniques, which were scaled to provide an alternative measure of interrogation severity. In Study 2, retributive motivation was manipulated by varying the terrorist past of a male suspect, and utilitarian motivation was manipulated by varying the probability that the suspect could provide valuable information. Additionally, we manipulated the suspect’s group membership. The results of the vignette study suggest that the number and severity of recommended interrogation techniques is mainly influenced by whether the suspect might provide valuable information. Whether the suspect had a terrorist past was an additional influence that, however, was primarily attributable to the suspect’s group membership: If the suspect belonged to the ingroup, participants’ harsher interrogation recommendations were affected by that person’s past, whereas recommendations were not significantly influenced by a terrorist past if the suspect was an outgroup member.
- Published
- 2013
46. Proteomic comparison of near-isogenic barley (Hordeum vulgare L.) germplasm differing in the allelic state of a major senescence QTL identifies numerous proteins involved in plant pathogen defense
- Author
-
Brian Bothner, Benjamin D. Reeves, Walid S. Maaty, Katelyn E. Mason, Paul A. Grieco, Jonathan K. Hilmer, and Andreas M. Fischer
- Subjects
0106 biological sciences ,0301 basic medicine ,Senescence ,Proteomics ,Proteases ,Proteome ,Physiology ,Quantitative Trait Loci ,Plant Science ,Flowers ,Quantitative trait locus ,Biology ,Genes, Plant ,01 natural sciences ,Mass Spectrometry ,Transcriptome ,03 medical and health sciences ,Botany ,Genetics ,Electrophoresis, Gel, Two-Dimensional ,Shotgun proteomics ,Alleles ,Disease Resistance ,Plant Diseases ,Plant Proteins ,food and beverages ,Plant physiology ,Hordeum ,Plant Leaves ,030104 developmental biology ,Seeds ,Electrophoresis, Polyacrylamide Gel ,Hordeum vulgare ,010606 plant biology & botany - Abstract
Senescence is the last developmental phase of plant tissues, organs and, in the case of monocarpic senescence, entire plants. In monocarpic crops such as barley, it leads to massive remobilization of nitrogen and other nutrients to developing seeds. To further investigate this process, a proteomic comparison of flag leaves of near-isogenic late- and early-senescing barley germplasm was performed. Protein samples at 14 and 21 days past anthesis were analyzed using both two-dimensional gel-based and label-free quantitative mass spectrometry-based (‘shotgun’) proteomic techniques. This approach identified >9000 barley proteins, and one-third of them were quantified. Analysis focused on proteins that were significantly (p
- Published
- 2016
47. The Complex Regulation of Senescence
- Author
-
Andreas M. Fischer
- Subjects
Plant senescence ,Genetics ,Senescence ,Transcriptome ,Color changes ,Plant Science ,Biology ,Gene ,Transcription factor ,Organism - Abstract
Everybody is familiar with the visual aspects of plant senescence. Color changes occurring in senescing leaves are, however, only one (albeit striking) symptom of the senescence process. As this process usually leads to cell, tissue, organ or even organism death, its timing is critical for plant fitness and, in an agricultural setting, for crop performance. It is therefore necessary to understand the mechanisms regulating senescence onset and rate, especially at the organ and (for annual species) organism level. Considering the importance of senescence for plant fitness, it is unsurprising that it is influenced by many environmental and genetic factors, rendering its detailed analysis challenging. Numerous molecular and transcriptomic studies have provided us with extensive lists of “senescence-associated genes” or “SAGs,” many of which may have functions in either the regulation or execution of senescence. Functional characterization has been initiated for a subset of SAGs, especially for transcription f...
- Published
- 2012
48. Downregulation of a barley (Hordeum vulgare) leucine-rich repeat, non-arginine-aspartate receptor-like protein kinase reduces expression of numerous genes involved in plant pathogen defense
- Author
-
David L. Parrott, Andreas M. Fischer, and Li Huang
- Subjects
0106 biological sciences ,0301 basic medicine ,Physiology ,Down-Regulation ,Locus (genetics) ,Plant Science ,Plant disease resistance ,Biology ,01 natural sciences ,Gene Expression Regulation, Enzymologic ,03 medical and health sciences ,Gene Expression Regulation, Plant ,Genetics ,Plant defense against herbivory ,Gene silencing ,Gene ,Disease Resistance ,Plant Diseases ,Plant Proteins ,fungi ,food and beverages ,Hordeum ,biology.organism_classification ,Plant Leaves ,030104 developmental biology ,Hordeum vulgare ,Protein Kinases ,Powdery mildew ,010606 plant biology & botany - Abstract
Pattern recognition receptors represent a first line of plant defense against pathogens. Comparing the flag leaf transcriptomes of barley (Hordeum vulgare L.) near-isogenic lines varying in the allelic state of a locus controlling senescence, we have previously identified a leucine-rich repeat receptor-like protein kinase gene (LRR-RLK; GenBank accession: AK249842), which was strongly upregulated in leaves of early-as compared to late-senescing germplasm. Bioinformatic analysis indicated that this gene codes for a subfamily XII, non-arginine-aspartate (non-RD) LRR-RLK. Virus-induced gene silencing resulted in a two-fold reduction of transcript levels as compared to controls. Transcriptomic comparison of leaves from untreated plants, from plants treated with virus only without any plant sequences (referred to as 'empty virus' control), and from plants in which AK249842 expression was knocked down identified numerous genes involved in pathogen defense. These genes were strongly induced in 'empty virus' as compared to untreated controls, but their expression was significantly reduced (again compared to 'empty virus' controls) when AK249842 was knocked down, indicating that their expression partially depends on the LRR-RLK investigated here. Expression analysis, using datasets from BarleyBase/PLEXdb, demonstrated that AK249842 transcript levels are heavily influenced by the allelic state of the well-characterized mildew resistance a (Mla) locus, and that the gene is induced after powdery mildew and stem rust infection. Together, our data suggest that AK249842 is a barley pattern recognition receptor with a tentative role in defense against fungal pathogens, setting the stage for its full functional characterization.
- Published
- 2015
49. Regnerischere Südseeinseln wegen Ozonloch
- Author
-
Andreas M. Fischer, Stefan Brönnimann, and Martín Jacques Coper
- Subjects
010504 meteorology & atmospheric sciences ,Environmental science ,010502 geochemistry & geophysics ,01 natural sciences ,0105 earth and related environmental sciences - Published
- 2017
50. Climate change projections for Switzerland based on a Bayesian multi-model approach
- Author
-
Christof Appenzeller, Mark A. Liniger, Andreas P. Weigel, Christoph Schär, Andreas M. Fischer, Christoph Buser, Hans R. Künsch, and Reto Knutti
- Subjects
Atmospheric Science ,Climatology ,Bayesian probability ,Probabilistic logic ,Environmental science ,Climate change ,Climate model ,Bayesian algorithm ,Precipitation ,Projection (set theory) ,Scaling - Abstract
Regional projections of future climate with associated uncertainty estimates are increasingly being demanded. Generally, such scenarios rely on a finite number of model projections and are accompanied by considerable uncertainties which cannot be fully quantified. Consequently, probabilistic climate projections are conditioned on several subjective assumptions which can be treated in a Bayesian framework. In this study, a recently developed Bayesian multi-model combination algorithm is applied to regional climate model simulations from the ENSEMBLES project to generate probabilistic projections for Switzerland. The seasonal temperature and precipitation scenarios are calculated relative to 1980–2009 for three 30-year scenario periods (centred at 2035, 2060, and 2085), three regions, and the A1B emission scenario. Projections for two further emission scenarios are obtained by pattern scaling. Key to the Bayesian algorithm is the determination of prior distributions about climatic parameters. It is shown that the prior choice of model projection uncertainty ultimately determines the uncertainty in the climate change signal. Here, we assume that model uncertainty is fully sampled by the climate models available. We have extended the algorithm such that internal decadal variability is also included in all scenario calculations. The A1B scenarios show a significant rise in temperature increasing from 0.9–1.4 °C by 2035 (depending upon region and season), to 2.0–2.9 °C by 2060, and to 2.7–4.1 °C by 2085. Mean precipitation changes are subject to large uncertainties with median changes close to zero. Significant signals are seen towards the end of the century with a summer drying of 18–24% depending on region, and a likely increase of winter precipitation in Switzerland south of the Alps. The A2 scenario implies a warming of 3.2–4.8 °C, and a summer drying of 21–28% by 2085, while in case of the mitigation scenario RCP3PD, climate change could be stabilized to 1.2–1.8 °C of warming and 8–10% of drying. Copyright © 2011 Royal Meteorological Society
- Published
- 2011
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