Bewertung der Schwermetallbelastung anhand einer multifunktionalen Referenz-Landschaft

Zur Bewertung der Schwermetallbelastung in Oberböden von Landschaften wurde ein normatives Szenario, das sogenannte Multifunktionalitätsszenario, als Referenz-Landschaft herangezogen. Der Schwermetallstatus der beiden Szenarien „Ist-Zustand“ sowie „multifunktionale Landschaft“ wurde mit dem Modell ATOMIS prognostiziert und die jährlichen Schwermetall-Inputfrachten in den Boden berechnet. Durch den Vergleich der Modellergebnisse konnten sowohl Defiziten als auch positive Effekte des aktuellen Bewirtschaftungssystems aufgezeigt werden. Die Schwermetalleinträge waren unter aktueller Landnutzung im Gebietsmittel bis zu 30 % höher als im Multifunktionalitätsszenario. Insbesondere durch die Umstellung auf Ökolandbau und extensive Grünlandnutzung können dabei die Inputfrachten und die Anreicherung von Schwermetallen im Oberboden reduziert werden

Numerisches Simulationsverfahren für die präzise Berechnung der menschlichen Phonation unter realen Bedingungen

Zsfassung in engl. SpracheDie menschliche Stimme ist das alltägliche Instrument zur verbalen Kommunikation. Eine Erkrankung der Stimme, die so genannte Dysphonie, wie Heiserkeit, kann somit beträchtliche Auswirkung auf die Lebensqualität haben. Einschränkungen auf privater sowie beruflicher Ebene sind die Folge. Um die Mechanismen und dessen Ursachen nachzuvollziehen, die eine gesunde Stimme von der einer erkrankten unterscheidet, muss zunächst der Stimmbildungsprozess grundlegend verstanden werden. Die computergestützte Simulation ist im Falle der menschlichen Phonation ein hilfreiches Werkzeug, da sie nicht invasiv ist. Allerdings stößt eine exakte Nachbildung der komplexen Vorgänge der Phonation an die Grenzen der heutigen Rechenkapazitäten. Um diesem entgegenzuwirken, ist es notwendig, das Modell zu vereinfachen. Diese Dissertation analysiert verschiedene Modellvereinfachungen und die dadurch verursachten modellbasierten Fehler. Für die Untersuchungen wurde das Computerprogramm CFS++ verwendet und erweitert, um die Interaktion von Strömung (Luft) und Strukturvibrationen (Stimmlippenschwingung) simulieren zu können. Ebenfalls können mit dem Programm die daraus entstehenden Schallquellen und die Schallausbreitung berechnet werden. Zuerst wird die Auswirkung der geometrischen Modellierung der Stimmlippen untersucht. Dazu werden in einer voll gekoppelten Strömungs- Struktur-Simulation die Schwingungen zweier unterschiedlicher geometrischer Stimmlippenmodelle genauestens miteinander verglichen. Ferner wird untersucht, ob die Kopplung von Strömung und Struktur zu einer reinen Strömungssimulation reduziert werden kann. Die Schwingung der Stimmlippen wird dabei mit speziellen Randbedingungen imitiert. Zusätzlich werden unterschiedliche aeroakustische Analogien untersucht und verglichen. Die akustischen Verfahren ermöglichen dabei eine genaue Ortung der akustischen Quellen bei der Stimmerzeugung. Das entwickelte Simulationsverfahren ist ebenfalls dazu fähig, den Vokaltrakt zu berücksichtigen, um beispielsweise das erzeugte Schallfeld eines Vokals zu berechnen.The human voice is essential for day-to-day communication. Consequently, impairment of speech, known as dysphonia, may have a significant impact on a person-s career and possible even their social life. To understand the mechanisms and effects that distinguish a healthy voice from an unhealthy one, the phonation process itself must be understood. In the case of human phonation, computer aided simulation is a useful tool, as it is non-invasive. However, if the target is to achieve an exact replica, the complex nature of the phonation process pushes the bounds of current research and also demands high computational capacities. Simplifications in the model are therefore necessary to counteract these problems. This thesis analyses different kinds of simplifications and the error which is caused by the corresponding model. These investigations were carried out with the simulation tool CFS++, and extended to allow for a precise simulation of the interaction between air flow and structural (vocal fold) vibration. Furthermore, it is also capable of determining the acoustic sources and propagation of aeroacoustical and vibration-induced sound. Firstly, the impact of the geometrical shape of the vocal folds is studied. Thereby, a fully coupled fluid-structure simulation is employed to compare two different kinds of vocal fold models. Moreover, investigations have been performed if the coupling of fluid and structure can be reduced to a pure flow simulation. The vocal fold vibration is thereby imitated by special boundary conditions. In addition, different aeroacoustic analogies are analysed and compared. These acoustic methods also permit a precise location of the sound sources during phonation. We also present and enhancement of the model, which integrates and considers the acoustic impact of the vocal tract, to calculate for instance the sound field of a vowel.10

arc42 by example: software architecture documentation in practice

This book teaches everything you need to know to jumpstart your own software architecture documentation. Through several elaborate examples, you'll learn how to write useful documentation that clearly explains the architecture of your software

Clinical Evaluation of Extracellular ADMA Concentrations in Human Blood and Adipose Tissue

Circulating asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis, has been proposed as a biomarker for clinical outcome. Dimethylarginine dimethylaminohydrolase (DDAH) is the main enzyme responsible for ADMA metabolism and elimination. Adipose tissue ADMA concentrations and DDAH activity and their role in diabetes and obesity have not yet been investigated. In this study, we evaluated clinical microdialysis in combination with a sensitive analytical method (GC-MS/MS) to measure ADMA concentrations in extracellular fluid. Adipose tissue ADMA concentrations were assessed before and during an oral glucose tolerance test in lean healthy subjects and subjects with diabetes (n = 4 each), and in morbidly obese subjects before and after weight loss of 30 kg (n = 7). DDAH activity was determined in subcutaneous and visceral adipose tissue obtained during laparoscopic surgery (n = 5 paired samples). Mean interstitial ADMA concentrations did not differ between study populations (healthy 0.17 ± 0.03 µM; diabetic 0.21 ± 0.03 µM; morbidly obese 0.16 ± 0.01 and 0.17 ± 0.01 µM before and after weight loss, respectively). We did not observe any response of interstitial ADMA concentrations to the oral glucose challenge. Adipose tissue DDAH activity was negligible compared to liver tissue. Thus, adipose tissue ADMA plays a minor role in NO-dependent regulation of adipose tissue blood flow and metabolism

Clinical Evaluation of Extracellular ADMA Concentrations in Human Blood and Adipose Tissue

Circulating asymmetrical dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis, has been proposed as a biomarker for clinical outcome. Dimethylarginine dimethylaminohydrolase (DDAH) is the main enzyme responsible for ADMA metabolism and elimination. Adipose tissue ADMA concentrations and DDAH activity and their role in diabetes and obesity have not yet been investigated. In this study, we evaluated clinical microdialysis in combination with a sensitive analytical method (GC-MS/MS) to measure ADMA concentrations in extracellular fluid. Adipose tissue ADMA concentrations were assessed before and during an oral glucose tolerance test in lean healthy subjects and subjects with diabetes (n = 4 each), and in morbidly obese subjects before and after weight loss of 30 kg (n = 7). DDAH activity was determined in subcutaneous and visceral adipose tissue obtained during laparoscopic surgery (n = 5 paired samples). Mean interstitial ADMA concentrations did not differ between study populations (healthy 0.17 ± 0.03 µM; diabetic 0.21 ± 0.03 µM; morbidly obese 0.16 ± 0.01 and 0.17 ± 0.01 µM before and after weight loss, respectively). We did not observe any response of interstitial ADMA concentrations to the oral glucose challenge. Adipose tissue DDAH activity was negligible compared to liver tissue. Thus, adipose tissue ADMA plays a minor role in NO-dependent regulation of adipose tissue blood flow and metabolism

High-Impact, Self-Motivated Training Within an Enriched Environment With Single Animal Tracking Dose-Dependently Promotes Motor Skill Acquisition and Functional Recovery

Functional recovery following central nervous system injuries is strongly influenced by rehabilitative training. In the clinical setting, the intensity of training and the level of motivation for a particular task are known to play important roles. With increasing neuroscience studies investigating the effects of training and rehabilitation, it is important to understand how the amount and type of training of individuals influences outcome. However, little is known about the influence of spontaneous "self-training" during daily life as it is often uncontrolled, not recorded, and mostly disregarded. Here, we investigated the effects of the intensity of self-training on motor skill acquisition in normal, intact rats and on the recovery of functional motor behavior following spinal cord injury in adult rats. We used a custom-designed small animal tracking system, "RatTrack," to continuously record the activity of multiple rats, simultaneously in a complex Natural Habitat-enriched environment. Naïve, adult rats performed high-intensity, self-motivated motor training, which resulted in them out-performing rats that were conventionally housed and trained on skilled movement tasks, for example, skilled prehension (grasping) and ladder walking. Following spinal cord injury the amount of self-training was correlated with improved functional recovery. These data suggest that high-impact, self-motivated training leads to superior skill acquisition and functional recovery than conventional training paradigms. These findings have important implications for the design of animal studies investigating rehabilitation and for the planning of human rehabilitation programs