Einsatz geostatistischer Verfahren zur Charakterisierung der Grundwasserbeschaffenheit im Bereich der Rieselfelder südlich Berlins

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The North Atlantic Waveguide and Downstream Impact Experiment

The North Atlantic Waveguide and Downstream Impact Experiment (NAWDEX) explored the impact of diabatic processes on disturbances of the jet stream and their influence on downstream high-impact weather through the deployment of four research aircraft, each with a sophisticated set of remote sensing and in situ instruments, and coordinated with a suite of ground-based measurements. A total of 49 research flights were performed, including, for the first time, coordinated flights of the four aircraft: the German High Altitude and Long Range Research Aircraft (HALO), the Deutsches Zentrum für Luft- und Raumfahrt (DLR) Dassault Falcon 20, the French Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE) Falcon 20, and the British Facility for Airborne Atmospheric Measurements (FAAM) BAe 146. The observation period from 17 September to 22 October 2016 with frequently occurring extratropical and tropical cyclones was ideal for investigating midlatitude weather over the North Atlantic. NAWDEX featured three sequences of upstream triggers of waveguide disturbances, as well as their dynamic interaction with the jet stream, subsequent development, and eventual downstream weather impact on Europe. Examples are presented to highlight the wealth of phenomena that were sampled, the comprehensive coverage, and the multifaceted nature of the measurements. This unique dataset forms the basis for future case studies and detailed evaluations of weather and climate predictions to improve our understanding of diabatic influences on Rossby waves and the downstream impacts of weather systems affecting Europe

Use of geostatistics in groundwater chemistry, a case study from the sewage farms south of Berlin, Germany

Am Beispiel eines durch Rieselfeld- und Landwirtschaft stark anthropogen beeinflußten Grundwassers wird der Einsatz geostatistischer Verfahren in der Hydrochemie demonstriert. Bedingt durch die anthropogene Überprägung ist die Grundwasserbeschaffenheit durch häufige Extremwerte, sehr große Spannweiten und eine insgesamt hohe Variabilität gekennzeichnet. Rieselfeld- und Landwirtschaft führen zu einer deutlichen Erhöhung der Konzentrationen von Kalium, Calcium, Magnesium, Chlorid, Hydrogenkarbonat und Sulfat sowie der Nährstoffe Nitrat und Phosphat. Calcium und Sulfat werden allerdings, im Gegensatz zu den anderen Wasserinhaltsstoffen, durch die Landwirtschaft merklich stärker als durch die Rieselfeldwirtschaft erhöht. Natrium hingegen wird nur durch die Rieselfeldwirtschaft beeinflußt und eignet sich dadurch, im Zusammenhang mit seinem relativ konservativen Verhalten, gut als Leitparameter für eine Abwasserbeeinflussung. Obwohl die Grundwasserbeschaffenheit im 1. und 2. Grundwasserleiter sich im Mittel kaum unterscheidet, ist die räumliche Kontinuität im 2. Grundwasserleiter wesentlich höher. Dies wird darauf zurückgeführt, daß sich Diffusion und Dispersion im 2. Grundwasserleiter stärker auswirken. Ursachen für die geringe räumliche Kontinuität im 1. Grundwasserleiter sind: Der starke anthropogene Einfluß durch die Rieselfeld- und die Landwirtschaft. Die große Variabilität des Bodens, die eine hohe Variabilität der Beschaffenheit des Sickerwassers verursacht und die dominante vertikale Strömung im 1. Grundwasserleiter, durch die die hydrodynamische Dispersion in horizontaler Richtung relativ gering ist. Um die Eignung eines Datensatzes zur mathematisch korrekten Regionalisierung zu überprüfen, wurde das Konzept des K-Wertes entwickelt. Das Konzept des K-Wertes baut auf den Ergebnissen der explorativen Statistik und der Variographie auf. Der K-Wert kombiniert die für eine sinnvolle Regionalisierung notwendigen Faktoren "Anzahl der Stützstellen", "räumliche Verteilung der Stützstellen" und "räumliche Kontinuität der betrachteten Variable" zu einer Maßzahl. Diese Maßzahl ermöglicht eine schnelle, schematisierte und objektive Beurteilung einer großen Anzahl an Variablen. Standardisierte Variogramme, die die Varianz der einzelnen Abstandsklassen berücksichtigen, haben sich als gutes Werkzeug zur Beschreibung der räumlichen Kontinuität von durch Extremwerte verzerrte Datensätze erwiesen. Als für hydrochemische Fragestellungen insgesamt sehr geeignet zeigte sich der Indikator-Ansatz. Durch seine Unabhängigkeit von der Verteilungsform kann er zur Analyse aller Parameter der Grundwasserbeschaffenheit eingesetzt werden. Besonders interessant ist das auf dem Indikator-Variogramm aufbauende Indikator-Kriging, mit dessen Hilfe Wahrscheinlichkeitskarten zur Prognose der Grundwasserbeschaffenheit erstellt werden können.The aim of this thesis is to demonstrate the sensible use of geostatistical methods on groundwater chemistry data. All methods are shown on an extensive data set gathered from two quaternary aquifers beneath a sewage irrigation farm south of Berlin (Germany). The aquifers are made up from sand and are divided by glacial till. Groundwater chemistry in this area is highly influenced by sewage irrigation and agriculture. Both lead to high potassium, calcium, magnesium, chloride, hydrogencarbonate and sulfate concentrations as well as a remarkable increase in nitrate and phosphate. Calcium and sulfate concentrations are more influenced by agriculture then by sewage irrigation. On the other hand sodium has been proven as a good indicator for sewage influence. For biased distributions due to extreme values standardized variograms are useful, as the variogram is rescaled by the lag variance. For data sets with lognormal or multi-modal distribution, indicator variograms are even more reliable. For the indicator approach the data are classified in reference to one or more chosen thresholds. With an indicator variogram the spatial continuity related to the chosen threshold is studied. Especially usefule for hydrochemical data is indicator kriging, which produces maps of the probability that groundwater constituents exceed defined thresholds. Indicator kriging is independent of the distribution of the data set hence it can be used for highly skewed data as is common in pollution cases. To prove the suitability of kriging for individual data sets the concept of the k-value was developed. The k-value combines the necessary factors for a reasonable regionalisation to one number hence the k-value opens a fast, systematic and objective way to judge the possibility to use kriging for regionalisation. The necessary factors are the ratio between the density of the measurement points and the range of the variogram, and the size of the nugget compared to the sill of the variogram. A reasonable regionalisation is only possible if the range of the variogram compared to the measurement point density is large, and the nugget effect compared to the sill of the variogram is small

Seeded free-electron laser driven by a compact laser plasma accelerator

International audienceAbstract Free-electron lasers generate high-brilliance coherent radiation at wavelengths spanning from the infrared to the X-ray domains. The recent development of short-wavelength seeded free-electron lasers now allows for unprecedented levels of control on longitudinal coherence, opening new scientific avenues such as ultra-fast dynamics on complex systems and X-ray nonlinear optics. Although those devices rely on state-of-the-art large-scale accelerators, advancements on laser-plasma accelerators, which harness gigavolt-per-centimetre accelerating fields, showcase a promising technology as compact drivers for free-electron lasers. Using such footprint-reduced accelerators, exponential amplification of a shot-noise type of radiation in a self-amplified spontaneous emission configuration was recently achieved. However, employing this compact approach for the delivery of temporally coherent pulses in a controlled manner has remained a major challenge. Here we present the experimental demonstration of a laser-plasma accelerator-driven free-electron laser in a seeded configuration, where control over the radiation wavelength is accomplished. Furthermore, the appearance of interference fringes, resulting from the interaction between the phase-locked emitted radiation and the seed, confirms longitudinal coherence. Building on our scientific achievements, we anticipate a navigable pathway to extreme-ultraviolet wavelengths, paving the way towards smaller-scale free-electron lasers, unique tools for a multitude of applications in industry, laboratories and universities

Seeded free-electron laser driven by a compact laser plasma accelerator

Free-electron lasers generate high-brilliance coherent radiation at wavelengths spanning from the infrared to the X-ray domains. The recent development of short-wavelength seeded free-electron lasers now allows for unprecedented levels of control on longitudinal coherence[1], opening new scientific avenues as ultra-fast dynamics on complex systems and X-ray nonlinear optics. While those devices rely on state-of-the-art large-scale accelerators, advancements on laser-plasma accelerators, which harness giga-volt-per-centimeter accelerating fields, showcase a promising technology as compact drivers for free-electron lasers. Using such miniaturized accelerators, exponential amplification of a shot-noise type of radiation in a self-amplified spontaneous emission configuration was recently achieved [2]. However, employing this compact approach for the delivery of temporally coherent pulses in a controlled manner remained a major challenge. Here, we present the experimental demonstration of a laser-plasma accelerator driven free-electron laser in a seeded configuration, where control over the radiation wavelength is accomplished. Furthermore, the appearance of interference fringes, resulting from the interaction between the phase-locked emitted radiation and the seed, confirms longitudinal coherence. Building on our scientific achievements, we anticipate a straightforward scaling to extreme-ultraviolet wavelengths, paving the way towards university-scale free-electron lasers, unique tools for a multitude of applications. [1] Meyer, M. FELs of europe: Whitebook on science with free electron lasers 8–19 (2016). [2] Wang, W. et al. Free-electron lasing at 27 nanometres based on a laser wakefield accelerator

A Large Number of Protein Expression Changes Occur Early in Life and Precede Phenotype Onset in a Mouse Model for Huntington Disease*S⃞

Huntington disease (HD) is fatal in humans within 15–20 years of symptomatic disease. Although late stage HD has been studied extensively, protein expression changes that occur at the early stages of disease and during disease progression have not been reported. In this study, we used a large two-dimensional gel/mass spectrometry-based proteomics approach to investigate HD-induced protein expression alterations and their kinetics at very early stages and during the course of disease. The murine HD model R6/2 was investigated at 2, 4, 6, 8, and 12 weeks of age, corresponding to absence of disease and early, intermediate, and late stage HD. Unexpectedly the most HD stage-specific protein changes (71–100%) as well as a drastic alteration (almost 6% of the proteome) in protein expression occurred already as early as 2 weeks of age. Early changes included mainly the up-regulation of proteins involved in glycolysis/gluconeogenesis and the down-regulation of the actin cytoskeleton. This suggests a period of highly variable protein expression that precedes the onset of HD phenotypes. Although an up-regulation of glycolysis/gluconeogenesis-related protein alterations remained dominant during HD progression, late stage alterations at 12 weeks showed an up-regulation of proteins involved in proteasomal function. The early changes in HD coincide with a peak in protein alteration during normal mouse development at 2 weeks of age that may be responsible for these massive changes. Protein and mRNA data sets showed a large overlap on the level of affected pathways but not single proteins/mRNAs. Our observations suggest that HD is characterized by a highly dynamic disease pathology not represented by linear protein concentration alterations over the course of disease