Indikation der Selbstorganisationsfähigkeit von terrestrischen Ökosystemen

In der vorliegenden Arbeit wird ein Konzept zur ökosystemar ausgerichteten Indikation des Umweltzustandes formuliert. Es orientiert sich an den Erkenntnissen über die Selbstorga- nisationsfähigkeit von Ökosystemen. Diese Eigenschaft von Ökosystemen wird als eine wesentliche Voraussetzung für eine ökologische Risikovorsorge gesehen. Unter ökosystemarer Selbstorganisation wird die Fähigkeit von Ökosystemen verstanden, spontan ihren Selbstorganisations- grad zu erhöhen, oder diesen bei sich verändernden Rahmenbe- dingungen der Systementwicklung zu erhalten. Ausgehend vom Selbstorganisationsparadigma werden in der vor- liegenden Arbeit vier Themenbereiche abgeleitet, die für die Indikation der Selbstorganisationsfähigkeit von Ökosystemen von Bedeutung sind. Diesen vier Themenbereichen werden je- weils zwei Teilindikanda und die entsprechenden Indikatoren zugeordnet: 1. Ökologische Thermodynamik: Exergie-Aufnahme (Bruttoprimär- produktion); Entropie-Export (Entropiebilanz nach AOKI (1987)) 2. Organisation/Komplexität: Biotische Diversität (Artenzahlen ausgewählter Artengruppen); Abiotische Heterogenität (Heterogenitätsindex nach Reiche (in Vorb.)) 3. Stoffliche Grundlagen der Ökosystementwicklung: Speicherung Biomasse und intrabiotisch gespeicherte Nährstoffe); Nährstoffverluste (modellierte Stickstoffverluste) 4. Ökophysiologische Effizienz: Biotische Wassernutzung Quotient aus Transpiration und Gesamtverdunstung); Stoffwechseleffizienz (Quotient aus Respiration und Biomasse) Mit Ausnahme der Größe Entropiebilanz nach AOKI (1987) sind die in dieser Arbeit vorgestellten Indikatoren auf der Grund- lage der verwendeten Datenbasis und Methodik als gut bis sehr gut nutzbar für die Indikation der Selbstorganisations- fähigkeit von Ökosystemen zu bewerten. Als Rahmen für die Implementation der vorgestellten Indikatoren kann neben den Umweltökonomischen Gesamtrechnungen auch die ökosystemare Umweltbeobachtung (UBA 2000) dienen

High structural diversity of aeruginosins in bloom-forming cyanobacteria of the genus Planktothrix as a consequence of multiple recombination events.

Many compounds produced by cyanobacteria act as serine protease inhibitors, such as the tetrapeptides aeruginosins (Aer), which are found widely distributed. The structural diversity of Aer is intriguingly high. However, the genetic basis of this remains elusive. In this study, we explored the genetic basis of Aer synthesis among the filamentous cyanobacteria Planktothrix spp. In total, 124 strains, isolated from diverse freshwater waterbodies, have been compared regarding variability within Aer biosynthesis genes and the consequences for structural diversity. The high structural variability could be explained by various recombination processes affecting Aer synthesis, above all, the acquisition of accessory enzymes involved in post synthesis modification of the Aer peptide (e.g., halogenases, glycosyltransferases, sulfotransferases) as well as a large-range recombination of Aer biosynthesis genes, probably transferred from the bloom-forming cyanobacterium Microcystis. The Aer structural composition differed between evolutionary Planktothrix lineages, adapted to either shallow or deep waterbodies of the temperate climatic zone. Thus, for the first time among bloom-forming cyanobacteria, chemical diversification of a peptide family related to eco-evolutionary diversification has been described. It is concluded that various Aer peptides resulting from the recombination event act in chemical defense, possibly as a replacement for microcystins

Multimodal Optical Medical Imaging Concepts Based on Optical Coherence Tomography

Optical medical imaging techniques in general exhibit outstanding resolution and molecule-specific contrast. They come however with a limited penetration in depth and small field of view. Multimodal concepts help to combine complementary strengths of different imaging technologies. The present article reviews the advantages of optical multimodal imaging concepts using optical coherence tomography (OCT) as core technology. In particular we first discuss polarization sensitive OCT, Doppler OCT and OCT angiography, OCT elastography, and spectroscopic OCT as intramodal concepts. To highlight intermodal imaging concepts, we then chose the combination of OCT with photoacoustics, and with non-linear optical microscopy. The selected multimodal concepts and their particular complementary strengths and applications are discussed in detail. The article concludes with notes on standardization of OCT imaging and multimodal extensions

Macht und Machtpolitik: Neorealistische Außenpolitiktheorie und Prognosen für die deutsche Außenpolitik nach der Vereinigung

Im Kontext des DFG-Forschungsprojekts 'Deutsche Außenpolitik nach der Vereinigung' am Institut für Politikwissenschaft der Universität Tübingen entstandenes Papier, das den 'Neorealismus' als Paradigma der Theorie der Internationalen Beziehungen auf die Außenpolitiktheorie anzuwenden versucht. Es wird versucht, aus theoretischer Perspektive die Annahmen des Neorealismus in Variablen für die Untersuchung der Außenpolitik einzelner Staaten umzusetzen. Am Schluß wird kurz die Machtposition Deutschlands und werden Prognosen für die deutsche Außenpolitik formuliert

Power and Power Politics: Neorealist Foreign Policy Theory and Expectations about German Foreign Policy since Unification

Im Kontext des DFG-Forschungsprojekts 'Deutsche Außenpolitik nach der Vereinigung' am Institut für Politikwissenschaft der Universität Tübingen entstandenes Papier, das den 'Neorealismus' als Paradigma der Theorie der Internationalen Beziehungen auf die Außenpolitiktheorie anzuwenden versucht. Es wird versucht, aus theoretischer Perspektive die Annahmen des Neorealismus in Variablen für die Untersuchung der Außenpolitik einzelner Staaten umzusetzen. Am Schluß wird kurz die Machtposition Deutschlands und werden Prognosen für die deutsche Außenpolitik formuliert

The History of Stereotactic and Functional Neurosurgery in Zurich

Zurich's stereotactic and functional neurosurgery (SFN) has a rich legacy beginning with the studies of the physiologist and Nobel prize winner Walter Rudolf Hess over the efforts of the neurosurgeons Hugo Krayenbühl and Mahmut Gazi Yaşargil up to the work of the functional surgeon Jean Siegfried and the modern era of SFN and neuromodulation. A comprehensive review and synthesis of data acquired from institutional archives and personal interviews as well as from journal articles, included references, proceedings of scientific meetings, staff biographies, and book publications were performed to gain insight into Zurich's long journey toward contemporary SFN and to highlight its stereotactic and functional history with special reference to the development of deep brain stimulation. Zurich's history of medicine includes decisive moments for the fundamentals and development of SFN. After an early period of innovation and research later followed by a long time of clinical application during the 20th century, it became quieter at the turn of the century. Since the end of the 2000s, an impressive renaissance occurred in Zurich that revived its rich SFN tradition

Technical feasibility of using auditory phase-targeted stimulation after pediatric severe traumatic brain injury in an intensive care setting

Background: Supplementary treatment options after pediatric severe traumatic brain injury (TBI) are needed to improve neurodevelopmental outcome. Evidence suggests enhancement of brain delta waves via auditory phase-targeted stimulation might support neuronal reorganization, however, this method has never been applied in analgosedated patients on the pediatric intensive care unit (PICU). Therefore, we conducted a feasibility study to investigate this approach: In a first recording phase, we examined feasibility of recording over time and in a second stimulation phase, we applied stimulation to address tolerability and efficacy. Methods: Pediatric patients (> 12 months of age) with severe TBI were included between May 2019 and August 2021. An electroencephalography (EEG) device capable of automatic delta wave detection and sound delivery through headphones was used to record brain activity and for stimulation (MHSL-SleepBand version 2). Stimulation tolerability was evaluated based on report of nurses, visual inspection of EEG data and clinical signals (heart rate, intracranial pressure), and whether escalation of therapy to reduce intracranial pressure was needed. Stimulation efficacy was investigated by comparing EEG power spectra of active stimulation versus muted stimulation (unpaired t-tests). Results: In total, 4 out of 32 TBI patients admitted to the PICU (12.5%) between 4 and 15 years of age were enrolled in the study. All patients were enrolled in the recording phase and the last one also to the stimulation phase. Recordings started within 5 days after insult and lasted for 1-4 days. Overall, 23-88 h of EEG data per patient were collected. In patient 4, stimulation was enabled for 50 min: No signs of patient stress reactions were observed. Power spectrums between active and muted stimulation were not statistically different (all P > .05). Conclusion: Results suggests good feasibility of continuously applying devices needed for auditory stimulation over multiple days in pediatric patients with TBI on PICU. Very preliminary evidence suggests good tolerability of auditory stimuli, but efficacy of auditory stimuli to enhance delta waves remains unclear and requires further investigation. However, only low numbers of severe TBI patients could be enrolled in the study and, thus, future studies should consider an international multicentre approach

Performance of ECG-based seizure detection algorithms strongly depends on training and test conditions

Objective To identify non-EEG-based signals and algorithms for detection of motor and non-motor seizures in people lying in bed during video-EEG (VEEG) monitoring and to test whether these algorithms work in freely moving people during mobile EEG recordings. Methods Data of three groups of adult people with epilepsy (PwE) were analyzed. Group 1 underwent VEEG with additional devices (accelerometry, ECG, electrodermal activity); group 2 underwent VEEG; and group 3 underwent mobile EEG recordings both including one-lead ECG. All seizure types were analyzed. Feature extraction and machine-learning techniques were applied to develop seizure detection algorithms. Performance was expressed as sensitivity, precision, F$_{1}$ score, and false positives per 24 hours. Results The algorithms were developed in group 1 (35 PwE, 33 seizures) and achieved best results (F$_{1}$ score 56%, sensitivity 67%, precision 45%, false positives 0.7/24 hours) when ECG features alone were used, with no improvement by including accelerometry and electrodermal activity. In group 2 (97 PwE, 255 seizures), this ECG-based algorithm largely achieved the same performance (F$_{1}$ score 51%, sensitivity 39%, precision 73%, false positives 0.4/24 hours). In group 3 (30 PwE, 51 seizures), the same ECG-based algorithm failed to meet up with the performance in groups 1 and 2 (F$_{1}$ score 27%, sensitivity 31%, precision 23%, false positives 1.2/24 hours). ECG-based algorithms were also separately trained on data of groups 2 and 3 and tested on the data of the other groups, yielding maximal F1 scores between 8% and 26%. Significance Our results suggest that algorithms based on ECG features alone can provide clinically meaningful performance for automatic detection of all seizure types. Our study also underscores that the circumstances under which such algorithms were developed, and the selection of the training and test data sets need to be considered and limit the application of such systems to unseen patient groups behaving in different conditions