Paraglacial sediment storage quantification in the Turtmann Valley, Swiss Alps

Sediment flux plays a central role within evolution of land surfaces and Earth's biogeochemical system. Within sediment flux systems, the role of sediment storage is often the least understood part. This study analyses the spatial distribution of sediment storage and quantifies sediment volumes in the high Alpine Turtmann Valley, Swiss Alps. A detailed geomorphological mapping provided information on the distribution structure of storage landforms. Geophysical methods were used to derive sediment thickness of single landforms in one hanging valley that have been used to model the storage volume for different landform types in all hanging valleys. The remaining sediment stores were quantified using different, subsystem specific GIS approaches. A total sediment volume of 780 - 1,030 x 106 m3 is stored in the Turtmann Valley. More than 70 % of the material is located in the hanging valleys, resulting from a de-coupling and closure of the hanging valley subsystem. Within the hanging valleys, moraine deposits store the greatest volumes (70%), while slope landforms cover the largest areas (> 50%). Thus, the spatial distribution of stores emerges from the system behaviour, process intensity and land surface structure of the hanging valleys. Average denudation rates for the Turtmann Valley vary between 0.9 and 1.25 mm a-1, calculated for a time period of 10 ka. Single landform denudation rates vary from 0.2 – 3.1 mm a-1 for talus slopes and cones to 0.1 – 1.8 mm a-1 for active rock glaciers. These values lie within the ranges of comparable values for the Alps. The spatial pattern of landforms is used to infer a relative model of paraglacial landform evolution. A reworking of glacial deposits in the hanging valleys was accomplished mainly by glacier derived rock glaciers. Their distribution hints on three phases of paraglacial evolution since the End of the Pleistocene. Since most of today’s active rock glaciers are talus-derived, the reworking of paraglacial deposits is most probably completed and the paraglacial period in the hanging valleys of the Turtmann Valley is considered to be terminated. This study presents a method to quantify landform volumes in a meso-scale alpine catchment. For the first time volumes are quantified for different landform types. Thus, a gap is closed between previously performed small scale studies and large river catchment investigations that provide non differentiated sediment volumes. A comparison of denudation rates indicates that the quantified volumes lie within a realistic range of previous studies. Finally, the importance of rock glaciers in the paraglacial evolution of the valley and the sediment storage distribution stresses the role of periglacial processes in the sediment flux system of high alpine environments. Quantifizierung paraglazialer Sedimentspeicher im Turtmanntal, Schweizer Alpen Im bio-geochemischen Kreislauf der Erde spielt der Sedimentfluss eine wichtige Rolle. Bei der Analyse von Sedimentfluss-Systemen ist jedoch die Rolle der Speicherung von Sediment oft die am wenigsten verstandene Komponente. In dieser Arbeit wird die räumliche Verbreitungsstruktur von Sedimentspeichern im hochalpinen Turtmanntal, Schweizer Alpen, analysiert und die Sedimentmenge quantifiziert. Basis für die räumliche Analyse der Formen ist eine detaillierte geomorphologische Karte und ein daraus resultierendes Formeninventar des Turtmanntals. Sedimentmächtigkeiten wurden lokal bestimmt mit Hilfe geophysikalischer Untergrundsondierungen. Dabei wurden Refraktionsseismik, 2-D Geoelektrik und Georadar in einem Hängetal angewandt. Die ermittelten Sedimentmächtigkeiten wurden interpoliert, um eine Abschätzung des Sedimentvolumens in dem Hängetal vorzunehmen. Die mittleren Mächtigkeiten der einzelnen Sedimentspeichertypen dieses Hängetales werden genutzt, um die Volumina derselben Speichertypen im Gesamttal zu quantifizieren. Zusätzlich werden verschiedene GIS-Methoden, angepasst auf die Subsysteme des Sedimentfluss-Systems Turtmanntal, zur Quantifizierung der Sedimentmenge benutzt. Insgesamt werden zwischen 780 und 1030 x 106 m3 an Sediment im Turtmanntal gespeichert. Über 70 % davon lagern in den 13 Hängetälern, was sich durch die Entkopplung dieses Subsystems von den anderen Subsystemen und dem damit verbundenen verhinderten Austrag erklären lässt. Moränen speichern das größten Sedimentvolumen (60-75%). Die Hangspeichertypen bedecken die größten Flächen (> 50%) im Vergleich zu den anderen Speichertypen. Die Speichermengenverteilung ist Ausdruck der Subsystemkopplung, Prozessintensität und Reliefstruktur in den Hängetälern. Mittlere Denudationsraten schwanken zwischen 0.9 und 1.25 mm a-1 für das gesamte System, bezogen auf einen Zeitraum von 10 ka. Für einzelne Prozesse konnten mittlere Denudationsraten auf Basis der Speichermenge berechnet werden. Für Sturzprozesse wurden Werte von 0,2 – 3.1 mm a-1 auf Basis von Schutthalden ermittelt, aktive Blockgletscher zeigen Denudationsraten von 0.1 – 1.8 mm a-1. Diese Werte liegen in vergleichbaren Bereich anderer Werte aus dem Alpenraum. Die Verbreitungsstruktur der Sedimentspeicher gibt Hinweise auf die räumliche und zeitliche Prozessaktivität und lässt sich heranziehen die Postglaziale Landschaftsentwicklung des Turtmanntals zu rekonstruieren. Die aus Moränenmaterial entstandenen Blockgletscher haben dabei die wichtigste Rolle in der paraglazialen Entwicklung der Hängetäler gespielt. Aus ihrer Verbreitung wird ein 3-phasiges Landschaftsentwicklungsmodell dieser Bereiche erstellt. Aktuell dominieren Prozesse, die nur noch nicht-glaziales Sediment speichern. Somit wird die paraglaziale Periode der Hängetäler als beendet angesehen. Diese Untersuchung liefert zum ersten Mal Sedimentspeichervolumina für einzelne Speichertypen im alpinen Bereich. Die untersuchte Region schließt eine Lücke zwischen den bisherigen kleinräumigen Studien in einzelnen Karen und Hängetälern und Studien, die in großen Flusseinzugsgebieten gearbeitet haben. Die berechneten Denudationsraten deuten an, dass die Methode der Speicherquantifizierung auf dieser Skale vergleichbare Ergebnisse mit bisherigen Studien produziert. Im Rahmen der paraglazialen Landschaftsentwicklung wurde mit dieser Studie zum ersten Mal die besondere Rolle der Blockgletscher für den alpinen Raum aufgezeigt

Subtraction-noise projection in gravitational-wave detector networks

In this paper, we present a successful implementation of a subtraction-noise projection method into a simple, simulated data analysis pipeline of a gravitational-wave search. We investigate the problem to reveal a weak stochastic background signal which is covered by a strong foreground of compact-binary coalescences. The foreground which is estimated by matched filters, has to be subtracted from the data. Even an optimal analysis of foreground signals will leave subtraction noise due to estimation errors of template parameters which may corrupt the measurement of the background signal. The subtraction noise can be removed by a noise projection. We apply our analysis pipeline to the proposed future-generation space-borne Big Bang Observer (BBO) mission which seeks for a stochastic background of primordial GWs in the frequency range $\sim 0.1-1$Hz covered by a foreground of black-hole and neutron-star binaries. Our analysis is based on a simulation code which provides a dynamical model of a time-delay interferometer (TDI) network. It generates the data as time series and incorporates the analysis pipeline together with the noise projection. Our results confirm previous ad hoc predictions which say that BBO will be sensitive to backgrounds with fractional energy densities below $\Omega=10^{-16}$Comment: 54 pages, 15 figure

Geovisualization

Geovisualization involves the depiction of spatial data in an attempt to facilitate the interpretation of observational and simulated datasets through which Earth's surface and solid Earth processes may be understood. Numerous techniques can be applied to imagery, digital elevation models, and other geographic information system data layers to explore for patterns and depict landscape characteristics. Given the rapid proliferation of remotely sensed data and high-resolution digital elevation models, the focus is on the visualization of satellite imagery and terrain morphology, where manual human interpretation plays a fundamental role in the study of geomorphic processes and the mapping of landforms. A treatment of some techniques is provided that can be used to enhance satellite imagery and the visualization of the topography to improve landform identification as part of geomorphological mapping. Visual interaction with spatial data is an important part of exploring and understanding geomorphological datasets, and a variety of methods exist ranging across simple overlay, panning and zooming, 2.5D, 3D, and temporal analyses. Specific visualization outputs are also covered that focus on static and interactive methods of dissemination. Geomorphological mapping legends and the cartographic principles for map design are discussed, followed by details of dynamic web-based mapping systems that allow for greater immersive use by end users and the effective dissemination of data

Improving ICD-based semantic similarity by accounting for varying degrees of comorbidity

Finding similar patients is a common objective in precision medicine, facilitating treatment outcome assessment and clinical decision support. Choosing widely-available patient features and appropriate mathematical methods for similarity calculations is crucial. International Statistical Classification of Diseases and Related Health Problems (ICD) codes are used worldwide to encode diseases and are available for nearly all patients. Aggregated as sets consisting of primary and secondary diagnoses they can display a degree of comorbidity and reveal comorbidity patterns. It is possible to compute the similarity of patients based on their ICD codes by using semantic similarity algorithms. These algorithms have been traditionally evaluated using a single-term expert rated data set. However, real-word patient data often display varying degrees of documented comorbidities that might impair algorithm performance. To account for this, we present a scale term that considers documented comorbidity-variance. In this work, we compared the performance of 80 combinations of established algorithms in terms of semantic similarity based on ICD-code sets. The sets have been extracted from patients with a C25.X (pancreatic cancer) primary diagnosis and provide a variety of different combinations of ICD-codes. Using our scale term we yielded the best results with a combination of level-based information content, Leacock & Chodorow concept similarity and bipartite graph matching for the set similarities reaching a correlation of 0.75 with our expert's ground truth. Our results highlight the importance of accounting for comorbidity variance while demonstrating how well current semantic similarity algorithms perform.Comment: 11 pages, 6 figures, 1 tabl

Calibrated ice thickness estimate for all glaciers in Austria

Knowledge on ice thickness distribution and total ice volume is a prerequisite for computing future glacier change for both glaciological and hydrological applications. Various ice thickness estimation methods have been developed but regional differences in fundamental model parameters are substantial. Parameters calibrated with measured data at specific points in time and space can vary when glacier geometry and dynamics change. This study contributes to a better understanding of accuracies and limitations of modeled ice thicknesses by taking advantage of a comprehensive data set of in-situ ice thickness measurements from 58 glaciers in the Austrian Alps and observed glacier geometries of three Austrian glacier inventories (GI) between 1969 and 2006. The field data are used to calibrate an established ice thickness model to calculate an improved ice thickness data set for the Austrian Alps. A cross-validation between modeled and measured point ice thickness indicates a model uncertainty of 25–31% of the measured point ice thickness. The comparison of the modeled and measured average glacier ice thickness revealed an underestimation of 5% with a mean standard deviation of 15% for the glaciers with calibration data. The apparent mass balance gradient, the primary model parameter accounting for the effects of surface mass balance distribution as well as ice flux, substantially decreases over time and has to be adjusted for each temporal increment to correctly reproduce observed ice thickness. This reflects the general stagnation of glaciers in Austria. Using the calibrated parameter set, 93% of the observed ice thickness change on a glacier-specific scale could be captured for the periods between the GI. We applied optimized apparent mass balance gradients to all glaciers of the latest Austrian glacier inventory and found a volume of 15.9 km3 for the year 2006. The ten largest glaciers account for 25% of area and 35% of total ice volume. An estimate based on mass balance measurements from nine glaciers indicates an additional volume loss of 3.5 ± 0.4 km3 (i.e., 22 ± 2.5%) until 2016. Relative changes in area and volume were largest at glaciers smaller than 1 km2, and relative volume changes appear to be higher than relative area changes for all considered time periods

Fütterung auf den Praxisbetrieben im Verlauf der Interventionsstudie“Gesundheit und Leistung in der ökologischen Milchviehhaltung – Ausgangssituation Einfluss auf die Tiergesundheit

Die Fütterung hat einen bedeutenden Einfluss auf die Stoffwechselgesundheit und damit auf die Eutergesundheit beim Milchvieh. Aus der vorliegenden Datengrundlage des Projekts "Gesundheit und Leistungsfähigkeit von Milchkühen im Ökologischen Landbau interdisziplinär betrachtet" wird untersucht, welche Fütterungsparameter einschließlich des Fütterungsmanagements einen Einfluss auf das Stoffwechselgeschehen haben. Auch ist es möglich, eine Entwicklung der Betriebe aufgrund der Intervention darzustellen

Einstreumanagement in der Ökologischen Milchviehhaltung

The use of bedding materials of natural source is a requirement of the EU regulation of organic husbandry considering the needs of animals for dry comfortable lying areas. However, organic bedding materials provide an environment for mastitis pathogens, too and therefore increase the risk of intramammary infections if not well managed

Graphene Field-Effect Transistors for Millimeter Wave Amplifiers

In this work, we analyze high frequency performance of graphene field-effect transistors (GFETs), applying models of drain resistance, carrier velocity andsaturation velocity. This allows us to identify main limitations and propose an approach most promising for further development of the GFETs suitable for advanced mm-wave amplifiers. Analysis indicates, that the saturation velocity of charge carriers in the GFETs can be increased up to 5e7 cm/s via encapsulating graphene by hexagonal boron nitride layers, with corresponding increase of extrinsic maximum frequency of oscillation up to 180 GHz at 200 nm gate length

Effects of self-heating on fT and fmax performance of graphene field-effect transistors

It has been shown that there can be a significant temperature increase in graphene field-effect transistors (GFETs) operating under high drain bias, which is required for power gain. However, the possible effects of self-heating on the high-frequency performance of GFETs have been weakly addressed so far. In this article, we report on an experimental and theoretical study of the effects of self-heating on dc and high-frequency performance of GFETs by introducing a method that allows accurate evaluation of the effective channel temperature of GFETs with a submicrometer gate length. In the method, theoretical expressions for the transit frequency (fT) and the maximum frequency of oscillation (fmax) based on the small-signal equivalent circuit parameters are used in combination with the models of the field- and temperature-dependent charge carrier concentration, velocity, and saturation velocity of GFETs. The thermal resistances found by our method are in good agreement with those obtained by the solution of the Laplace equation and by the method of thermo-sensitive electrical parameters. Our experiments and modeling indicate that the self-heating can significantly degrade the fT and fmax of GFETs at power densities above 1 mW/μm\ub2, from approximately 25 to 20 GHz. This article provides valuable insights for further development of GFETs, taking into account the self-heating effects on the high-frequency performance

Entwicklung der Eutergesundheit im Zeitraum der Trockenperiode in ökologisch wirtschaftenden Milchviehbetrieben

As a part of the study „Health and performance of dairy cows in organic farming from an interdisciplinary point of view – an (intervention-) study on metabolic disorders and mastitis with regard to forage production, feeding management and husbandry practices” quarter milk samples from cows at dry off and after calving were taken by farmers in 101 dairy farms in Germany between January 2008 and April 2010. The objective of this study was to evaluate mastitis prevalence at dry off and at calving and the evaluation of different therapeutic regimes at dry off. 3460 cows from 101 dairy farms were examined. Mastitis prevalence at dry off was comparable to conventional farms. At calving organic farms have high mastitis prevalence due to a low cure rate and a high new infection rate in the dry period. The non-use of dry cow antibiotics or teat sealers result in significantly lower cure rates on quarter level (28.7% vs. 33,2%) and higher new infection rates (29.7% vs. 26.4%). The results show, that dry period is a high-risk period for udder health in organic dairy farms. Improvements of the hygienic conditions, the immune defence and the therapeutic regimes offer high potentials for improvement of udder health