352 research outputs found

    \u27Speech unhindered\u27: A study of irony in the Acts of the Apostles

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    This thesis explores Classical irony in the Acts of the Apostles. Recent studies of irony in Luke-Acts do not focus much on the Classical concept, developing their argument rather on more recent understandings. Although building on this literature, this thesis is grounded in a Classical understanding of irony, applies this to Acts, and reïŹ‚ects on its signiïŹcance for Luke-Acts as a whole. While contemporary writers often tend to understand irony as “incongruity between expectation and reality,” ïŹrst century CE Greek speakers saw irony or eironeia as a person’s behaviour, speciïŹcally as “pretension” or posturing. This behaviour, always calculated, conveys a feeling or knowledge which does not match the conveyer’s “real” feeling or knowledge. Eironeia takes two broad forms. The ïŹrst is transparent; this is pretension which one person wishes another to recognize as such, sometimes deïŹned as “saying one thing and conveying another.” The second is opaque; this is pretension which one person does not wish another to recognize, but rather to assume is candid behaviour, and it aims to mislead. Acts rarely offers clear examples of eironeia. Opaque eironeia comes from the unreliable character Festus, who pretences respect and fairness to Paul, seeking to mislead him. Behaviour somewhat like opaque eironeia, and transparent eironeia, come ïŹ‚\u27om the reliable character Paul, marking his preaching to Jews and to Gentiles. Behaviours somewhat like eironeia come from God, but should not be labelled as such. Eironeia and behaviours like it hint that Luke-Acts draws on New Comic theatre to help interpret its content. Taken together, the use of eironeia-like behaviours, of agnoia (“ignorance”), peripeteia (“reversal”), and other New Comic aspects, suggests that we must pay more attention to Luke’s knowledge of New Comedy

    Satellite data reveal differential responses of Swiss forests to unprecedented 2018 drought

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    Extreme events such as the summer drought of 2018 in Central Europe are projected to occur more frequently in the future and may cause major damages including increased tree mortality and negative impacts on forest ecosystem services. Here, we quantify the response of >1 million forest pixels of 10 × 10 m across Switzerland to the 2018 drought in terms of resistance, recovery, and resilience. We used the Normalized Difference Water Index (NDWI) derived from Sentinel-2 satellite data as a proxy for canopy water content and analyzed its relative change. We calculated NDWI change between the 2017 pre-drought and 2018 drought years (indicating resistance), 2018 and the 2019 post-drought (indicating recovery), and between 2017–2019 (indicating resilience). Analyzing the data from this large natural experiment, we found that for 4.3% of the Swiss forest the NDWI declined between 2017 and 2018, indicating areas with low resistance of the forest canopy to drought effects. While roughly 50% of this area recovered, in 2.7% of the forested area NDWI continued to decline from 2018 to 2019, suggesting prolonged negative effects or delayed damage. We found differential forest responses to drought associated with site topographic characteristics and forest stand characteristics, and to a lesser extent with climatic conditions and interactions between these drivers. Low drought resistance and high recovery were most prominent at forest edges, but also on south-facing slopes and lower elevations. Tree functional type was the most important driver of drought resilience, with most of the damage in stands with high conifer abundance. Our results demonstrate the suitability of satellite-based quantification of drought-induced forest damage at high spatial resolution across large areas. Such information is important to predict how local site characteristics may impact forest vulnerability to future extreme events and help in the search for appropriate adaptation strategies

    Insights for the partitioning of ecosystem evaporation and transpiration in short‐statured croplands

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    Reducing water losses in agriculture needs a solid understanding of when evaporation (E) losses occur and how much water is used through crop transpiration (T). Partitioning ecosystem T is however challenging, and even more so when it comes to short-statured crops, where many standard methods lead to inaccurate measurements. In this study, we combined biometeorological measurements with a Soil-Plant-Atmosphere Crop (SPA-Crop) model to estimate T and E at a Swiss cropland over two crop seasons with winter cereals. We compared our results with two data-driven approaches: The Transpiration Estimation Algorithm (TEA) and the underlying Water Use Efficiency (uWUE). Despite large differences in the productivity of both years, the T to evapotranspiration (ET) ratio had relatively similar seasonal and diurnal dynamics, and averaged to 0.72 and 0.73. Our measurements combined with a SPA-Crop model provided T estimates similar to the TEA method, while the uWUE method produced systematically lower T even when the soil and leaves were dry. T was strongly related to the leaf area index, but additionally varied due to climatic conditions. The most important climatic drivers controlling T were found to be the photosynthetic photon flux density (R2 = 0.84 and 0.87), and vapor pressure deficit (R2 = 0.86 and 0.70). Our results suggest that site-specific studies can help establish T/ET ratios, as well as identify dominant climatic drivers, which could then be used to partition T from reliable ET measurements. Moreover, our results suggest that the TEA method is a suitable tool for ET partitioning in short-statured croplands

    Cross-comparison of albedo products for glacier surfaces derived from airborne and satellite (sentinel-2 and landsat 8) optical data

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    Surface albedo partitions the amount of energy received by glacier surfaces from shortwave fluxes and modulates the energy available for melt processes. The ice- albedo feedback, influenced by the contamination of bare-ice surfaces with light- absorbing impurities, plays a major role in the melting of mountain glaciers in a warming climate. However, little is known about the spatial and temporal distribution and variability of bare-ice glacier surface albedo under changing conditions. In this study, we focus on two mountain glaciers located in the western Swiss Alps and perform a cross-comparison of different albedo products. We take advantage of high spectral and spatial resolution (284 bands, 2 m) imaging spectrometer data from the Airborne Prism Experiment (APEX) and investigate the applicability and potential of Sentinel-2 and Landsat 8 data to derive broadband albedo products. The performance of shortwave broadband albedo retrievals is tested and we assess the reliability of published narrow-to-broadband conversion algorithms. The resulting albedo products from the three sensors and different algorithms are further cross-compared. Moreover, the impact of the anisotropy correction is analysed depending on different surface types. While degradation of the spectral resolution impacted glacier-wide mean albedo by about 5%, reducing the spatial resolution resulted in changes of less than 1%. However, in any case, coarser spatial resolution was no longer able to represent small-scale variability of albedo on glacier surfaces. We discuss the implications when using Sentinel-2 and Landsat 8 to map dynamic glaciological processes and to monitor glacier surface albedo on larger spatial and more frequent temporal scales

    Diversity of 3D APAR and LAI dynamics in broadleaf and coniferous forests: Implications for the interpretation of remote sensing-based products

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    Forests substantially mediate the water and carbon dioxide exchanges between terrestrial ecosystems and the atmosphere. The rate of this exchange, including evapotranspiration (ET) and gross primary production (GPP), depends mainly on the underlying vegetation type, health state, and the composition of abiotic environmental drivers. However, the complex 3D structure of forest canopies and the inherent top-view perspective of optical and thermal remote sensing complicate remote sensing-based retrievals of biotic and abiotic factors that eventually determine ET and GPP. This study investigates the sensitivity of remote sensing approaches to 3D variation of abiotic and biotic environmental drivers. We use 3D virtual scenes of two structurally different Swiss forests and the radiative transfer model DART to simulate the 3D distribution of solar irradiance and reflected radiance in the forest canopy. These simulations, in combination with LiDAR data, are used to derive the absorbed photosynthetic active radiation (APAR) and the leaf area index (LAI) in 3D space. The 3D variation of both parameters was quantified and analyzed. We then simulated images of the top-of-canopy bi-directional reflectance factor (BRF) and compared them with the hemispheric-conical reflectance factor (HCRF) data derived from HyPlant airborne imaging spectrometer measurements. The simulated BRF data was used to derive APAR and LAI, and the results were compared to their respective 3D representations. We unravel considerable spatial differences between both representations. We discuss possible reasons for the disagreement, including a potential insensitivity of the inherent top-of-canopy view for the real 3D product dynamics and limitations of the processing of remote sensing data, especially the approximation of effective surface irradiance. Our results can help understanding sources of uncertainties in remote sensing based gas exchange products and defining mitigation strategies

    Non-photochemical quenching estimates from in situ spectroradiometer measurements: implications on remote sensing of sun-induced chlorophyll fluorescence in lakes

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    Quantum yield of fluorescence (ϕF) is key to interpret remote measurements of sun-induced fluorescence (SIF), and whether the SIF signal is governed by photochemical quenching (PQ) or non-photochemical quenching (NPQ). Disentangling PQ from NPQ allows using SIF estimates in various applications in aquatic optics. However, obtaining ϕF is challenging due to its high temporal and physiological variability, and the combined measurements needed to enclose all relevant optical paths. In inland waters, this type of data is scarce and information on diurnal and seasonal ϕF dynamics are almost unknown. Using an autonomous hyperspectral Thetis profiler in Lake Geneva, we demonstrate how to estimate ϕF using an ensemble of in-situ measurements acquired between 2018 to 2021. We use vertical and temporal changes in retrieved ϕF to determine NPQ and PQ conditions. We observed NPQ in 36% of the total daytime profiles used in the ϕF analysis. While downwelling irradiance is a significant contributor to ϕF, its role cannot be easily interpreted. Other factors such as phytoplankton photoregulation and assemblages also likely play significant roles in quenching mechanisms. We conclude that an adapted approach exploiting in-situ data is suitable to determine diurnal and seasonal NPQ occurrence, and helps develop future remote sensing algorithms

    Essener Brot - Herstellung und Verwendung von Keimlingen in der BĂ€ckerei

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    Der Leitfaden wendet sich in erster Linie an BĂ€cker, die Keimlinge in der BĂ€ckerei, zum Beispiel zur Herstellung von Keimlingsbroten oder Essener Broten, verwenden wollen, und gibt darĂŒber hinaus auch Einblicke, inwiefern Keimlinge als technologische Zutat eingesetzt werden können. Weiterhin kann dieser Leitfaden auch als Instrument fĂŒr Berater im BĂ€ckereiwesen verwendet werden. Der Leitfaden ist wie eine „Betriebsanleitung“ zu lesen und dient zur ErlĂ€uterung praktischer Vorgehensweisen. Reflexionen zu theoretischen HintergrĂŒnden finden eingeschrĂ€nkt und nur soweit statt, wie diese der ErlĂ€uterung der praktischen Vorgehensweisen dienen. Ziel eines jeden BĂ€ckers ist es, „gutes Brot“ zu backen. Um dies beim Backen mit Keimlingen zu erreichen, mĂŒssen bestimmte Parameter berĂŒcksichtigt werden. Der Einsatz von Keimlingen bedeutet letztlich den Einsatz von Auswuchsgetreide, weil durch das Keimen der Getreidekörner auch StĂ€rke abbauende Enzyme aktiviert werden. FĂŒr eine gleichbleibende BrotqualitĂ€t sollten die Keimlinge eine konstante NĂ€hrstoffzusammensetzung und eine möglichst niedrige Belastung mit Mikroorganismen aufweisen. Die QualitĂ€t der Keimlinge kann durch den Keimprozess beeinflusst werden. Beeinflussende Faktoren sind die Schichthöhe, die Keimdauer, die Feuchtigkeit und die Temperatur der Keime. Dazu gibt der Leitfaden konkrete Hinweise. Er gibt aber nicht nur eine Handlungsanweisung fĂŒr das optimale Keimen von Getreide, sondern auch fĂŒr ein bestmögliches Verbacken

    Imaging spectroscopy to assess the composition of ice surface materials and their impact on glacier mass balance

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    Glacier surfaces are not only composed of ice or snow but are heterogeneous mixtures of different materials. The occurrence and dynamics of light-absorbing impurities affect ice surface characteristics and strongly influence glacier melt processes. However, our understanding of the spatial distribution of impurities and their impact on ice surface characteristics and the glacier's energy budget is still limited. We use imaging spectroscopy in combination with in-situ experiments to assess the composition of ice surface materials and their respective impact on surface albedo and glacier melt rates. Spectroscopy data were acquired in August 2013 using the Airborne Prism EXperiment (APEX) imaging spectrometer and were used to map the abundances of six predominant surface materials on Glacier de la Plaine Morte, Swiss Alps. A pixel-based classification revealed that about 10% of the ice surface is covered with snow, water or debris. The remaining 90% of the surface can be divided into three types of glacier ice, namely ~ 7% dirty ice, ~ 43% pure ice and ~ 39% bright ice. Spatially distributed spectral albedo derived from APEX reflectance data in combination with in-situ multi-angular spectroscopic measurements was used to analyse albedo patterns present on the glacier surface. About 85% of all pixels exhibit a low albedo between 0.1 and 0.4 (mean albedo 0.29 ± 0.12), indicating that Glacier de la Plaine Morte is covered with a significant amount of light-absorbing impurities, resulting in a strong ice-albedo feedback during the ablation season. Using a pixel-based albedo map instead of a constant albedo for ice (0.34) as input for a mass balance model revealed that the glacier-wide total ablation remained similar (10% difference). However, the large local variations in mass balance can only be reproduced using the pixel-based albedo derived from APEX, emphasizing the need to quantify spatial albedo differences as an important input for glacier mass balance models

    Keimlinge als neuartige multifunktionelle Zutat in ökologischen Backwaren - Optimierung der Herstellung und Verwendung

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    Im Rahmen des Projektes „Keimlinge als neuartige multifunktionelle Zutat in ökologischen Backwaren - Optimierung der Herstellung und Verwendung“ wurde die sichere betriebseigene Herstellung von Keimlingen, der Einsatz von Keimlingen in Sprossenbroten und der Einsatz zu technologischen Zwecken entwickelt und optimiert. Diese allgemeinen Handlungsempfehlungen wurden in einem Leitfaden fĂŒr handwerkliche BĂ€ckereien festgehalten. Um gleichmĂ€ĂŸige Backergebnisse zu erhalten, werden Keimlinge mit konstanter QualitĂ€t benötigt. QualitĂ€tsbestimmende Faktoren sind die mikrobiologische Belastung, die wertgebenden Inhaltsstoffe und die Enzymatik. Das Keimergebnis lĂ€sst sich im Keimprozess durch die Keimtemperatur, die Schichthöhe und die Keimdauer beeinflussen und steuern. Die EinflĂŒsse dieser Faktoren auf die qualitĂ€tsbestimmenden Eigenschaften wurden im Projekt untersucht. Aus den Ergebnissen konnte die Faustzahl „15:15:30“ abgeleitet werden. Bei einer Schichthöhe von 15 cm, einer Keimtemperatur von maximal 15 °C und einer Keimdauer von 30 Stunden lassen sich gute Keimlingsergebnisse erzielen. Die Herstellung von Essener Broten stellt besondere Anforderungen an die TeigfĂŒhrung. Durch die Keimung kommt es zu einer deutlichen Vermehrung der EnzymaktivitĂ€t im Keimgut. Diese EnzymaktivitĂ€t ist insbesondere fĂŒr Roggenteige technologisch hoch relevant. Es empfiehlt sich, die Keimlinge möglichst spĂ€t und eher grob zerkleinert dem gut gesĂ€uerten Teig hinzu zu geben. Unter Einhaltung der im Leitfaden beschriebenen Bedingungen gelingt es, ein Essener Brot ausschließlich aus Keimlingen herzustellen. Je niedriger die Keimtemperatur, desto fester die Krumenbeschaffenheit und desto weniger klebrig ist die Krume. Die Backergebnisse sind durch die Temperatur bei der Keimung beeinflussbar und die Krumenfestigkeit bzw. die Krumenklebrigkeit kann gesteuert werden. Das so genannte Essener Brot wird typischerweise eher bei niedrigeren Temperaturen ĂŒber eine verlĂ€ngerte Backzeit gebacken. Die Keimlinge oder auch das so gewonnene aktive Malz kann zu Steuerung der Enzymatik bei der TeigfĂŒhrung eingesetzt werden. Der Einsatz von Roggenkeimlingen als Zutat bei Weizenbrot kann sehr positive Ergebnisse zeigen. Der Zerkleinerungsgrad der Keimlinge hat entscheidenden Einfluss auf die QualitĂ€t der hergestellten WeizengebĂ€cke. Insgesamt konnten das Volumen, die KrumenelastizitĂ€t und die Krumenfestigkeit verbessert werden
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