Book review: disappearing war: interdisciplinary perspectives on cinema and erasure in the post-9/11 world edited by Christina Hellmich and Lisa Purse

In Disappearing War: Interdisciplinary Perspectives on Cinema and Erasure in the Post-9/11 World, editors Christina Hellmich and Lisa Purse bring together contributors from across a range of disciplines to explore how depictions of contemporary warfare are frequently shaped by absence, erasure and a hierarchy of grievability. This is a theoretically robust, compelling and intriguing contribution to the 'aesthetic turn' within ..

A study of vibration induced distortion on the output current of photovoltaic solar modules

Das konstante Wachstum von Photovoltaikanlagen und der ungebremste Trend hin zu großen netzgekoppelten Systemen, schaffen neue Herausforderungen, um Netzstabilität und Versorgungsstabilität (Power Quality) zu gewährleisten. Durch Wind hervorgerufene Vibrationen wurden unter den vielen möglichen Störquellen bis jetzt größtenteils ignoriert. Mechanische Vibrationen der Halterung eines Solarmoduls verursachen Schwankungen in der Ausrichtung des Moduls gegenüber der Sonne. Die resultierenden Intensitätsschwankungen erzeugen eine Wechselstromkomponente an den Anschlussklemmen der Solarzelle. Diese Diplomarbeit untersucht diesen Effekt qualitativ, wobei die Resultate auf die spezifische Versuchsanordnung beschränkt bleiben. Trotzdem war es möglich die Größenordnung und deren möglichen Einfluss auf große netzgekoppelte Photovoltaikanlagen abzuschätzen. Messungen wurden im Labor, mithilfe eines Vibrationstisches und im Freien durchgeführt. Dort wurde ein Solarmodul am Dach des Institutsgebäudes der Physik angebracht, wo es realen Umweltbedingungen ausgesetzt war. Zusätzlich wurde eine Schaltkreissimulation durchgeführt um die erhaltenen Resultate zu bestätigen. Spezielle Aufmerksamkeit wurde auf drei Variable, in Abhängigkeit zu den Störsignalen der Solarzelle gerichtet: Erstens dem Betriebspunkt der Solarzelle. Hier zeigen die Resultate der Simulation, dass das Maximum des induzierten Störsignals etwas unterhalb, in Bezug auf die Spannung und den Widerstand, des optimalen Betriebspunktes (MPP) liegt. In dem Labormessungen lag das Maximum des Störsignals ebenso nahe des optimalen Betriebspunktes. Diese Störsignale können bei MPP Trackern zu Problemen führen.Dies konnte in den Labormessungen weder bestätigt noch ausgeschlossen werden, aber die zwei Punkte liegen definitiv sehr nah bei einander. Insgesamt könnten diese Störsignale bei MPP Trackern zu Problemen führen. Zweitens wurde die Serien- und Parallelschaltung von zwei Solarzellen simuliert und im Labor untersucht. Hier zeigen die Resultate eindeutig, dass parallel geschaltene Solarzellen weit weniger anfällig für Niedrigfrequenzstörungen sind. Der allgemeine Trend geht jedoch hin zu großen Serienschaltungen, um die Arbeitsspannung zu erhöhen. Drittens wurde die Winkelabhängigkeit im Labor und im Freien untersucht. Die Resultate zeigen, dass der Anteil von durch Vibrationen verursachten Störsignalen mit sinkender Fehlorientierung zur Sonne zurückgeht. Zusätzlich kann die optische Charakteristik der Verschalung des Moduls zu signifikanten Störungen führen, wenn das Licht in einem sehr flachen Winkel auf die Oberfläche der Solarzelle fällt.The constant growth of photovoltaic systems and the ongoing trend towards large scale grid connected PV plants, invokes new challenges in assuring power quality. Among the several noise sources, wind induced vibration has as yet been mainly ignored. Mechanical vibrations of a solar module mounting rack cause oscillations in the orientation of the module towards the sun. The resulting intensity oscillations of the incident light generate an a.c. current at the module's terminals. This diploma thesis examines this effect qualitatively, with most of the results being restricted to the given experimental setup. However it was possible to roughly asses the order of magnitude of these disturbances and their possible impact on large grid connected photovoltaic plants. Measurements have been executed in the laboratory by means of a vibration table and outdoors, where a solar panel was mounted at the roof top of the physics institute building in Vienna. There it was exposed to ambient conditions. Additionally a circuit simulation was carried through to confirm the aquired results. Special attention has been paid to the relation of three variables with regard to the disturbances of the solar cell: Firstly the operating point of the solar cell. Here the simulation results show that the maximum of the induced noise lies a little below but close to the maximum power point, with regard to the voltage or resistance. In the laboratory experiments the noise maximum also lay close to the MPP. This could neither be confirmed nor falsified by the laboratory experiments, but they are definitely very close to each other. However tThe induced noise may become important during MPP tracking. Secondly a parallel and a series circuit arrangement of two solar cells was examined in the laboratory and simulated, accounting for module and array wiring. Here the results unambiguously show that solar cells connected in parallel are much less prone to low frequency noise distortion, typical for wind induced vibration. However the general tendency in PV applications favours large series connections in order to increase the working voltage. Thirdly the angle dependency has been studied in the laboratory and outdoors. The results show that the proportion of vibration induced noise decreases with a low angle of misorientation. Additionally at very large angles, where the light source falls nearly perpendicular on the surface of the solar module, the optical characteristics of the casing of the module can lead to significant disturbances

Biosynthesis and Biological Profiling of Collinolactone and Semisynthetic Derivatives and MetaboIDent, a Novel Tool for Automated Dereplication

The rising incidences of age-related diseases such as Alzheimer and some types of cancer demand novel drugs and therapeutic concepts. Nature has already proven to be an extraordinary rich source of novel structural motifs. They can serve as lead structures for drug development like the prominent antibiotic vancomycin or the anti-cancer drug taxol. In this thesis, a novel natural product named collinolactone was isolated from Streptomyces sp. Gö 40/10. The compound possesses an unprecedented and unique 6-10-7-membered tricyclic system with a cyclodecatriene ring flanked by two lactone rings. Based on stable precursor feeding, a biosynthetic pathway via a type I polyketide synthase was postulated, which was then used for the identification of the encoding gene cluster. Follow-up CRISPR-based genetical engineering, optimization of fermentation parameters and the isolation procedure led to a high-production strain with yields of up to 100 mg/L. A representative and divers set of derivatives of collinolactone was synthesized including the use of Burgess reagent, Strykers reagent and Gilman cuprates. All compounds were profiled in a cell-viability assay on L929 cell line, where some compounds showed cytotoxicity in the micromolar range. The mode of action was studied with fluorescence microscopy on the cell cycle of PtK2 cells and an increased formation of monopolar spindles was observed. The inhibition of putative molecular targets was investigated in a malachite green ATP-based assay. Furthermore, collinolactone was found to exhibit neuroprotective properties in a glutamate induced intramolecular oxidative stress assay on HT22 cells. Only collinolactone showed an effect indicating that the binding is highly specific and even the smallest structural changes will lead to a loss of activity. In addition, the reduction of amyloid beta protein aggregates, one of the hallmarks for the development of Alzheimer disease, was studied. Again, collinolactone showed a reduction of aggregation, making it a very promising lead structure for further development towards a drug for Alzheimer therapy

Warning! Contains spoilers: reading post-‘9/11’ US security discourses through superhero films

This PhD thesis demonstrates how post-‘9/11’ US security discourses are co-constituted through Hollywood’s superhero genre, specifically the productions of Marvel and DC. In doing so it contributes to important debates within International Relations and Critical Security Studies that address the connections between popular culture and world politics. My interdisciplinary and inter-textual film analysis reveals that artefacts of popular culture have to be seen beyond their merely representational potential; on the contrary, popular culture becomes an important site to make sense of political issues as part of the mundane and the everyday, increasingly blurring the line between reality and fiction. Looking at American history and the development of the American Monomyth shows how superheroes were not created on a blank slate but were already born out of a specific narrative of the American nation in the 1930s. For those past 90 years, superheroes have been constant co-producers of crisis and conflict, making sense of foreign policy to domestic and global audiences. Their reinvigoration since 2001, leading into large-scale productions of the Marvel Cinematic Universe and the DC Extended Universe, corresponds with the crisis of ‘9/11’ and the ‘War on Terror’. Throughout the presidencies of Bush, Obama, and Trump they have been shaping the discursive elements of US security and foreign policy. The thesis argues that by engaging with superhero films, not as trivial pieces of entertainment but as important cultural artefacts that co-constitute political reality, scholars might find new ways to make sense of violence and conflict and seek new paths to a more peaceful world

Dexpanthenol in Wound Healing after Medical and Cosmetic Interventions (Postprocedure Wound Healing)

With the availability of new technologies, the number of subjects undergoing medical and cosmetic interventions is increasing. Many procedures (e.g., ablative fractional laser treatment) resulting in superficial/minor wounds require appropriate aftercare to prevent complications in wound healing and poor cosmetic outcome. We review the published evidence of the usefulness of topical dexpanthenol in postprocedure wound healing and the associated mechanisms of action at the molecular level. A search in the PubMed and Embase databases was performed to query the terms dexpanthenol, panthenol, superficial wound, minor wound, wound healing, skin repair, and postprocedure. Search results were categorized as clinical trials and in vitro studies. In vitro and clinical studies provided evidence that topically applied dexpanthenol promotes superficial and postprocedure wound healing. Latest findings confirmed that dexpanthenol upregulates genes that are critical for the healing process. The gene expression data are of clinical relevance as evidenced by prospective clinical studies indicating that topical dexpanthenol accelerates wound healing with rapid re-epithelialization and restoration of skin barrier function following skin injury. It can therefore be inferred that topical dexpanthenol represents an appropriate and state-of-the-art treatment option for superficial postprocedure wounds, especially when applied early after the superficial skin damage

Approximate exploitability: Learning a best response in large games

A standard metric used to measure the approximate optimality of policies in imperfect information games is exploitability, i.e. the performance of a policy against its worst-case opponent. However, exploitability is intractable to compute in large games as it requires a full traversal of the game tree to calculate a best response to the given policy. We introduce a new metric, approximate exploitability, that calculates an analogous metric using an approximate best response; the approximation is done by using search and reinforcement learning. This is a generalization of local best response, a domain specific evaluation metric used in poker. We provide empirical results for a specific instance of the method, demonstrating that our method converges to exploitability in the tabular and function approximation settings for small games. In large games, our method learns to exploit both strong and weak agents, learning to exploit an AlphaZero agent

New Legionella Control Options by UV and Violet LEDs for Hospitals and Care Facilities

Legionella infections caused by contaminated water are a widespread problem worldwide. Discharge lamps like mercury vapor lamps are widely known for the disinfection properties of their radiation, but they suffer technical disadvantages, like high voltages and toxic content, and are, therefore, not suitable for some infection control applications. New high-intensity ultraviolet (UV) and violet LEDs offer new approaches for Legionella control, because these bacteria are significantly light sensitive compared to other pathogens. One of the most important infection pathways is the inhalation of Legionella-containing aerosols during showering. This problem could be reduced by a single strong UV LED within the shower head, which irradiates the passing water for some milliseconds. This practice can be especially beneficial in hospitals and care facilities. UV light offers only a limited penetration depth, however, even in pure water. To disinfect larger water volumes, e.g., in water dispensers, visible violet LEDs are more appropriate. Unfortunately, up to now, neither approach has been given much attention by potential users