Tunable X-ray source by Thomson scattering during laser-wakefield acceleration

We report results on all-optical Thomson scattering intercepting the acceleration process in a laser wakefield accelerator. We show that the pulse collision position can be detected using transverse shadowgraphy which also facilitates alignment. As the electron beam energy is evolving inside the accelerator, the emitted spectrum changes with the scattering position. Such a configuration could be employed as accelerator diagnostic as well as reliable setup to generate x-rays with tunable energy

Chiral perturbation theory

Chiral perturbation theory (ChPT) is an effective field theory that describes the properties of strongly-interacting systems at energies far below typical hadron masses. The degrees of freedom are hadrons instead of the underlying quarks and gluons. ChPT is a systematic and model-independent approximation method based on an expansion of amplitudes in terms of light-quark masses and momenta. The following is a brief overview of ChPT that is largely based on Scherer, Schindler, Lect. Notes Phys. 830 (2012), which can be referred to for a more detailed introduction.Comment: contribution to the review "50 Years of Quantum Chromodynamics," edited by F. Gross and E. Klempt [arXiv:2212.11107], to be published in EPJ

Subliminal galvanic-vestibular stimulation influences ego- and object-centred components of visual neglect

Neglect patients show contralesional deficits in egocentric and object-centred visuospatial tasks. The extent to which these different phenomena are modulated by sensory stimulation remains to be clarified. Subliminal galvanic vestibular stimulation (GVS) induces imperceptible, polarity-specific changes in the cortical vestibular systems without the unpleasant side effects (nystagmus, vertigo) induced by caloric vestibular stimulation. While previous studies showed vestibular stimulation effects on egocentric spatial neglect phenomena, such effects were rarely demonstrated in object-centred neglect. Here, we applied bipolar subsensory GVS over the mastoids (mean intensity: 0.7. mA) to investigate its influence on egocentric (digit cancellation, text copying), object-centred (copy of symmetrical figures), or both (line bisection) components of visual neglect in 24 patients with unilateral right hemisphere stroke. Patients were assigned to two patient groups (impaired vs. normal in the respective task) on the basis of cut-off scores derived from the literature or from normal controls. Both groups performed all tasks under three experimental conditions carried out on three separate days: (a) sham/baseline GVS where no electric current was applied, (b) left cathodal/right anodal (CL/AR) GVS and (c) left anodal/right cathodal (AL/CR) GVS, for a period of 20. min per session. CL/AR GVS significantly improved line bisection and text copying whereas AL/CR GVS significantly ameliorated figure copying and digit cancellation. These GVS effects were selectively observed in the impaired- but not in the unimpaired patient group. In conclusion, subliminal GVS modulates ego- and object-centred components of visual neglect rapidly. Implications for neurorehabilitation are discussed

A Mini Review on the utilization of Reinforcement Learning with OPC UA

Reinforcement Learning (RL) is a powerful machine learning paradigm that has been applied in various fields such as robotics, natural language processing and game playing achieving state-of-the-art results. Targeted to solve sequential decision making problems, it is by design able to learn from experience and therefore adapt to changing dynamic environments. These capabilities make it a prime candidate for controlling and optimizing complex processes in industry. The key to fully exploiting this potential is the seamless integration of RL into existing industrial systems. The industrial communication standard Open Platform Communications UnifiedArchitecture (OPC UA) could bridge this gap. However, since RL and OPC UA are from different fields,there is a need for researchers to bridge the gap between the two technologies. This work serves to bridge this gap by providing a brief technical overview of both technologies and carrying out a semi-exhaustive literature review to gain insights on how RL and OPC UA are applied in combination. With this survey, three main research topics have been identified, following the intersection of RL with OPC UA. The results of the literature review show that RL is a promising technology for the control and optimization of industrial processes, but does not yet have the necessary standardized interfaces to be deployed in real-world scenarios with reasonably low effort.Comment: submitted to INDIN'2

Dadia National Park, Greece - an integrated study on landscape, biodiversity, raptor populations and conservation management

Der globale Wandel verursacht derzeit einen starken Verlust an Biodiversität und für den Menschen notwendigen Ökosystemleistungen. Die Erfassung von Status und Trends von Landschaften, Artenvielfalt und Populationen bedrohter Arten ist notwendiger denn je und sollte im Rahmen von integrativem Naturschutzmanagement geschehen. Diese Dissertation fasst Studien über Landschaft, Biodiversität, Greifvogelpopulationen und Naturschutzmanagement für den Dadia National Park (Dadia NP) zusammen, ein Schutzgebiet in Nordost-Griechenland, das durch seine außergewöhnlich hohe Biodiversität gekennzeichnet ist. In den zwölf wissenschaftlichen Artikeln, die diese Dissertation umfasst, werden Fragestellungen zu folgenden Themen bearbeitet: 1) Habitatheterogenität und Biodiversität im Dadia NP, 2) Landschaftsökologische Ansätze und geographische Informationssysteme (GIS) für Biodiversitätsmanagement, 3) Sets an Landschaftsmaßzahlen für Landschaftsstrukturanalysen, 4) Maßstabsübergreifende Anwendung von Landschaftsmaßen als Biodiversitätsindikatoren für Pflanzen, Insekten und Wirbeltieren, 5) ökologische Heterogenität als Werkzeug zur systematischen Planung von Schutzgebietsnetzwerken, 6) Evaluierung eines Telemetriesystems zur Erfassung von Mönchsgeiern (Aegypius monachus), 7) GIS-basierende Methoden zur Revierkartierung von Greifvögeln, 8) Habitat, Status und Bestandstrends von Populationen tagaktiver Greifvögel, 9) ein Entscheidungsunterstützungssystem zur Berücksichtigung bedrohter Arten im Forstmanagement, und 10) Zusammenstellung aller in wissenschaftlicher Literatur für Dadia NP und den bulgarischen Teil der Ost-Rhodopen empfohlenen Naturschutzmaßnahmen und Ermittlung ihrer Umsetzungsrate und Evaluierungsrate. Zusammenfassend lässt sich sagen, dass in Dadia NP und ähnlichen mediterranen Schutzgebieten ein Landschaftsmonitoring neben dem Monitoring von Schlüssel- und Indikatorarten wesentlich zur Erfassung der Effektivität einzelner Naturschutzmaßnahmen für Habitate und deren assoziierte Arten beitragen kann. Fortführende ökologische Forschung und Monitoring sind besonders wichtig für die Etablierung von integrativem Naturschutzmangement zum Erhalt von Biodiversität und Ökosystemleistungen. Die Naturschutzforschung liefert die notwendigen Grundlagen für Naturschutzmanager und Entscheidungsträger, aber mangelnder politischer Wille für kompetente Naturschutzbehörden beeinträchtigt die Umsetzung und Evaluierung der erarbeiteten Naturschutzmaßnahmen.Global change is currently causing a strong decline of biodiversity and in the provision of essential ecosystem services. Assessments of status and trends of landscapes, biodiversity, and endangered species are needed and should be conducted in the framework of an integrated conservation management. This doctoral thesis is a cumulative work dealing with landscape, biodiversity, raptor populations, and conservation management of Dadia National Park (Dadia NP), a local hotspot of biodiversity in north-eastern Greece. In the twelve research articles that constitute this thesis, I investigated with my coauthors 1) habitat heterogeneity and biodiversity of Dadia NP, 2) landscape approaches and GIS applications for biodiversity management, 3) sets of landscape metrics for landscape structure analyses, 4) the multiscale performance of landscape metrics as biodiversity indicators for plants, insects and vertebrates, 5) the use of ecological heterogeneity to design reserve networks, 6) the performance of a telemetry system for Eurasian Black Vulture (Aegypius monachus), 7) GIS-based methodologies for territory analyses of raptors, 8) habitat, status and population trends of the diurnal raptor populations of Dadia NP, 9) decision support systems for the conservation of biodiversity in managed forest, and 10) the evidence base of conservation management in Dadia NP and the Bulgarian part if the Eastern Rhodpes Mountains. It can be concluded for Dadia NP and similar Mediterranean reserves that landscape surveillance should be integrated into the ecological monitoring of key and indicator species to aid the evaluation of management effects on habitats and wildlife. Further and consistent ecological monitoring and research is crucial for establishing integrative biodiversity conservation and management. Conservation research is providing important evidence for conservation managers and decision makers, but lack of political will for competent conservation authorities leads to weak rates of implementation and evaluation