Pointcatcher software:analysis of glacial time-lapse photography and integration with multi-temporal digital elevation models

Terrestrial time-lapse photography offers insight into glacial processes through high spatial and temporal resolution imagery. However, oblique camera views complicate measurement in geographic coordinates, and lead to reliance on specific imaging geometries or simplifying assumptions for calculating parameters such as ice velocity. We develop a novel approach that integrates time-lapse imagery with multi-temporal digital elevation models to derive full 3D coordinates for natural features tracked throughout a monoscopic image sequence. This enables daily independent measurement of horizontal (ice flow) and vertical (ice melt) velocities. By combining two terrestrial laser scanner surveys with a 73-day sequence from Sólheimajökull, Iceland, variations in horizontal ice velocity of ~10% were identified over timescales of ~25 days. An overall surface elevation decrease of ~3.0 m showed rate changes asynchronous with the horizontal velocity variations, demonstrating a temporal disconnect between the processes of ice surface lowering and mechanisms of glacier movement. Our software, ‘Pointcatcher’, is freely available for user-friendly interactive processing of general time-lapse sequences and includes Monte Carlo error analysis and uncertainty projection onto DEM surfaces. It is particularly suited for analysis of challenging oblique glacial imagery, and we discuss good features to track, both for correction of camera motion and for deriving ice velocities

Fluorescence lifetime spectroscopy of tissue autofluorescence in normal and diseased colon measured ex vivo using a fiber-optic probe

We present an ex vivo study of temporally and spectrally resolved autofluorescence in a total of 47 endoscopic excision biopsy/resection specimens from colon, using pulsed excitation laser sources operating at wavelengths of 375 nm and 435 nm. A paired analysis of normal and neoplastic (adenomatous polyp) tissue specimens obtained from the same patient yielded a significant difference in the mean spectrally averaged autofluorescence lifetime −570 ± 740 ps (p = 0.021, n = 12). We also investigated the fluorescence signature of non-neoplastic polyps (n = 6) and inflammatory bowel disease (n = 4) compared to normal tissue in a small number of specimens

A 490 GHz planar circuit balanced Nb-Al2_\mathbf{2}O3_{\mathbf{3}}-Nb quasiparticle mixer for radio astronomy: Application to quantitative local oscillator noise determination

This article presents a heterodyne experiment which uses a 380-520 GHz planar circuit balanced Nb-$\mathrm{Al_2O_3}$-Nb superconductor-insulator-superconductor (SIS) quasiparticle mixer with 4-8 GHz instantaneous intermediate frequency (IF) bandwidth to quantitatively determine local oscillator (LO) noise. A balanced mixer is a unique tool to separate noise at the mixer's LO port from other noise sources. This is not possible in single-ended mixers. The antisymmetric IV characteristic of a SIS mixer further helps to simplify the measurements. The double-sideband receiver sensitivity of the balanced mixer is 2-4 times the quantum noise limit $h\nu/k_B$ over the measured frequencies with a maximum LO noise rejection of 15 dB. This work presents independent measurements with three different LO sources that produce the reference frequency but also an amount of near-carrier noise power which is quantified in the experiment as a function of the LO and IF frequency in terms of an equivalent noise temperature $T_{LO}$. In a second experiment we use only one of two SIS mixers of the balanced mixer chip, in order to verify the influence of near-carrier LO noise power on a single-ended heterodyne mixer measurement. We find an IF frequency dependence of near-carrier LO noise power. The frequency-resolved IF noise temperature slope is flat or slightly negative for the single-ended mixer. This is in contrast to the IF slope of the balanced mixer itself which is positive due to the expected IF roll-off of the mixer. This indicates a higher noise level closer to the LO's carrier frequency. Our findings imply that near-carrier LO noise has the largest impact on the sensitivity of a receiver system which uses mixers with a low IF band, for example superconducting hot-electron bolometer (HEB) mixers.Comment: 13 pages, 8 figures, 2 tables, see manuscript for complete abstrac

Dead-Ice Under Different Climate Conditions: Processes, Landforms, Sediments and Melt Rates in Iceland and Svalbard

Modern dead-ice environments in the glacier forefields of Brúarjökull, Iceland and Holmströmbreen, Svalbard were investigated with focus on landform and sediment genesis, as well as quantification of melting. Field monitoring and studies of multi-temporal aerial photographs, satellite imagery, and Digital Elevation Models (DEMs) provided data for the melting quantification. Sedimentological and geomorphological data were achieved through field investigations and image analyses. Different measures for dead-ice melting (backwasting, downwasting, ice-walled lake area, glacier retreat and thinning) are assessed in relation to local air temperature data going back to the beginning of the instrumental period. A geomorphological map in scale 1:16 000 of the forefield of the surge-type glacier Brúarjökull was produced through digital aerial photograph interpretation and high-resolution DEM analyses. The map was used for the interpretation of landforms and sediments, and provided an overview of the surging glacier landsystem at Brúarjökull. A conceptual model for the formation of transitional-state ice-cored landforms ? ice-cored drumlins ? was also constructed, based on the research in the Brúarjökull forefield. After a complete melting, the model proposes that such drumlins will disintegrate into patches of hummocky dead-ice moraine. Three years of fieldwork combined with analyses of multi-temporal DEMs and aerial photographs revealed that multiple generations of ice-cored moraines are currently exposed to melting at Brúarjökull. Quantifying the melting progression suggests that in the current climate, a complete de-icing of ice-cored landforms is not likely to occur. Some dead-ice bodies are recycled into new ice-cored landforms, because the total melt-out time exceeds the duration of the quiescent period in the surge cycles. Long-term surface lowering due to dead-ice melting takes place with a rate of c. 0.10-0.18 m/yr. At the stagnant snout of Holmströmbreen, an extensive dead-ice area with ice-cored moraines, eskers and kames has developed since the Little Ice Age glacial maximum. Backwasting of ice-cored slopes and mass-movement processes continuously expose new dead-ice and prevents the build-up of an insulating debris-cover. Currently dead-ice melting progresses with a long-term surface lowering rate of c. 0.9 m/yr. The most prominent impact of dead-ice melting is the development of an extensive ice-walled, moraine-dammed lake receiving sediment from the adjacent slopes. Based on a literature review and the results presented here, dead-ice melting in different climatic settings is discussed, with focus on melt rates and sediment-landform genesis. Because identical processes operate with similar rates in different climates, dead-ice deposits provide little information on the climate at the time of deposition. The glaciodynamic significance of dead-ice deposits is that of stagnation of debris-covered glaciers

Prevention of Ankle Sprains

Ankle instability is weakness of the ankles due to previous injuries. According to the National Collegiate Athletic Association (NCAA), more than 460,000 college athletes play a total of 24 sports. Results from Indiana University showed that 67% of former players claim they suffered a major injury while competing n the collegiate level

Butterick\u27s Fashion Polka

https://digitalcommons.library.umaine.edu/mmb-ps/1001/thumbnail.jp

A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death, disability, etc. In our treatment of participating life insurance, we have special focus on the bonus schemes “consolidation” and “additional benefits”, and one goal is to formalize how these work and interact. Another goal is to describe similarities and differences between participating life insurance and unit-linked insurance. By use of a two-account model, we are able to illustrate general concepts without making the model too abstract. To allow for complicated financial markets without dramatically increasing the mathematical complexity, we focus on economic scenarios. We illustrate the use of our model by conducting scenario analysis based on Monte Carlo simulation, but the model applies to scenarios in general and to worst-case and best-estimate scenarios in particular. In addition to easy computations, our model offers a common framework for the valuation of life insurance payments across product types. This enables comparison of participating life insurance products and unit-linked insurance products, thus building a bridge between the two different ways of formalizing life insurance products. Finally, our model distinguishes itself from the existing literature by taking into account the Markov model for the state of the policyholder and, hereby, facilitating event risk

Exploring Automatic Text Simplification of German Narrative Documents

In this paper, we apply transformer-based Natural Language Generation (NLG) techniques to the problem of text simplification. Currently, there are only a few German datasets available for text simplification, even fewer with larger and aligned documents, and not a single one with narrative texts. In this paper, we explore to which degree modern NLG techniques can be applied to German narrative text simplifications. We use Longformer attention and a pre-trained mBART model. Our findings indicate that the existing approaches for German are not able to solve the task properly. We conclude on a few directions for future research to address this problem

The influence of ground ice distribution on geomorphic dynamics since the Little Ice Age in proglacial areas of two cirque glacier systems

International audienceHolocene glaciers have contributed to an abundance of unstable sediments in mountainous environments. In permafrostenvironments, these sediments can contain ground ice and are subject to rapid geomorphic activity and evolution undercondition of a warming climate. To understand the influence of ground ice distribution on this activity since the Little Ice Age(LIA), we have investigated the Pierre Ronde and Rognes proglacial areas, two cirque glacier systems located in the periglacial beltof the Mont Blanc massif. For the first time, electrical resistivity tomography, temperature data loggers and differential global positioningsystems (dGPS) are combined with historical documents and glaciological data analysis to produce a complete study of evolutionin time and space of these small landsystems since the LIA. This approach allows to explain spatial heterogeneity of current internalstructure and dynamics. The studied sites are a complex assemblage of debris-covered glacier, ice-rich frozen debris and unfrozendebris. Ground ice distribution is related to former glacier thermal regime, isolating effect of debris cover, water supply to specificzones, and topography. In relation with this internal structure, present dynamics are dominated by rapid ice melt in the debriscoveredupper slopes, slow creep processes in marginal glacigenic rock glaciers, and weak, superficial reworking in deglaciatedmoraines. Since the LIA, geomorphic activity is mainly spatially restricted within the proglacial areas. Sediment exportation hasoccurred in a limited part of the former Rognes Glacier and through water pocket outburst flood and debris flows in Pierre Ronde.Both sites contributed little sediment supply to the downslope geomorphic system, rather by episodic events than by constant supply.In that way, during Holocene and even in a paraglacial context as the recent deglaciation, proglacial areas of cirque glaciers actmostly as sediment sinks, when active geomorphic processes are unable to evacuate sediment downslope, especially because ofthe slope angle weakness

Untersuchung der Auswirkung von variablem LED-Licht auf die Executive-Attention unter Berücksichtigung vom depressiven und saisonal-depressivem Empfinden

Einleitung Im Rahmen der Lichtforschung wird die Wirkung von adaptiven Lichtquellen auf diverse Verhaltens- und Erlebensqualitäten des Menschen fortlaufend untersucht. Insbesondere deren Effekt auf die Aufmerksamkeitsleistung stellt ein Interessensgebiet in der Kognitionspsychologie dar. So findet variables, LED-basiertes Licht Anwendung in der Optimierung von Hintergrundbedingungen in Schulklassen und Arbeitsräumen. Allerdings wurden auch alters- und geschlechtsspezifische Unterschiede in den präferierten Lichtverhältnissen identifiziert, welche auf die Komplexität dieser Assoziationen hindeuten. Methodik In vorliegendem Experiment wurden insgesamt 483 Probanden herangezogen, um im Rahmen des Attention-Network Tests die Wirkung von LED-Licht auf die Executive-Attention-Komponente unter Berücksichtigung von depressivem und saisonal-depressivem Empfinden zu untersuchen. Dafür erfolgte eine randomisierte Zuweisung in drei Lichtbedingungen: (I) Tageslicht (6514 K; 1238 lx), (II) Warmweiß (3201 K; 169 lx) und (III) Neutralweiß (3671; 395 lx). Ergebnisse Es zeigten sich keine Haupteffekte von Licht auf die Executive-Attention-Komponente. Mit Einschluss der Kovariaten zeichneten sich signifikante Haupteffekte mit kleinen Effektstärken zugunsten der warmweißen Lichtbedingung ab. Diskussion Die prognostizierte Überlegenheit der Tageslichtbedingung und Unterlegenheit der warmweißen Lichtbedingung wurde nicht beobachtet. Die Alters- und Geschlechtsverteilung in vorliegender Stichprobe sowie potenzielle Stör- und Moderatorvariablen werden diskutiert