Hochschule Bonn-Rhein-Sieg
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Informationssicherheitsmanagementsysteme aus einer systemtheoretischen Sicht
No full textDie Thesis befasst sich mit der Darstellung der Systemtheorie Niklas Luhmanns als theoretisches Fundament zur Erforschung von Informationssicherheitsmanagementsystemen (ISMS). Anhand von verschiedenen Anwendungsfällen stellt diese Arbeit die Vorzüge der Theorie Luhmanns gegenüber Keiner oder anderen Theorien dar
Sensory monitoring and laser-induced initiation of primary explosives
No full textEnergetic materials (EMs) are compounds or mixtures of substances that contain both fuel and an oxidizer. When these materials react, they release thermal energy and produce a large amount of gas. The initiation of these substances can be triggered by mechanical, thermal, electrostatic, or optical influence. A distinction is made between materials that are capable of exploding and those that are hazardous due to their potential to explode [1].
EMs are not only used for military purposes, but also for civilian applications, such as in airbags, fireworks or explosives in mining. It has been a long way from the initial invention of the first explosives to their widespread use today. In 220 B.C., the Chinese accidentally discovered black powder. Centuries later, in the 13th and 14th centuries, the monk Roger Bacon and the German Berthold Schwarz researched the explosive for the first time in Europe. The military use of black powder began at this time. In 1846, nitroglycerine was discovered by Ascanio Sobrero. Alfred Nobel reduced the sensitivity of the highly sensitive nitroglycerine, thus making it possible to use the substance. The so-called dynamite was developed. Alfred Nobel also played an important role in the progress in the history of initial substances. His findings made it possible to reliably initiate dynamite by replacing black powder with mercury fulminate. This was replaced at the beginning of the 20th century by lead azide, which is still used today [2, 3].
In the following years, as demand increased, other explosives were developed and synthesised, many of which are still in use today. This led to the development of trinitrotoluene, triaminotrinitrobenzene and hexogen (RDX), for example. The focus in the development of energetic materials changed over time. In addition to reliability, the safe handling of the substances was often at the centre of research when it came to their commercial/military use. During the Second World War, for example, the use of polymer-bound explosives was favoured, resulting in the production of Semtex, a mixture of nitropenta (PETN) and RDX bound with styrene-butadiene rubber. Today, the focus of the development of energetic materials is on environmentally friendly research into materials in terms of sustainability and the improvement of existing properties (e.g. shorter initiation times for special military applications)
Stereoisomers of Chiral Methyl-Substituted Symmetric and Asymmetric Aryl Piperazinium Compounds Exhibit Distinct Selectivity for α9 and α7 Nicotinic Acetylcholine Receptors
No full textWe have characterized families of phenylpiperazine (PP) compounds, studying their relative activity with α7 and α9* nicotinic acetylcholine receptors (nAChRs) and focusing on the effects of side groups on the phenyl ring (R1) and the effects of different alkyl groups on the base nitrogen. In this study, we evaluated the impact of methyl substitution on the piperazine ring, which introduced a chiral center, enabling the generation and separation of stereoisomers. Methyl groups were added to either the C2 or C3 positions on the piperazine of the α9α10 agonist/α7 partial agonist PA-EMPP. Additions at the C3 position greatly reduced activity, while additions at the C2 position had selective effects on either α7 or α9/α10 activity. The 2-methyl S and R isomers of PA-EMPP contain a second chiral center at the nitrogen. Notably, replacing the terminal substitution with N,N-dimethyl abolished α9/α910 agonist activity, rendering the compound selective for α7. We also tested 2M isomers of the α9α10 agonist pCN-EMPP and obtained similar enantioselective activity as observed with the PA-EMPP isomers. Compounds were studied for their ability to reduce the ATP-dependent release of IL-1β from monocytes, one aspect of the cholinergic anti-inflammatory activity. Results were consistent with their apparent activation or antagonism of α9* receptors. These findings underscore the critical role of chirality and structural modifications in fine-tuning receptor selectivity, offering valuable insights for the rational design of selective nicotinic therapeutics
A Grounded Theory of how Consumers Determine the Veracity of Online User Reviews
No full textConsumers are using online reviews to decide which products to purchase. Cybercriminals produce fake reviews to influence unknowing consumers into buying products of lower quality, which can lead to financial, emotional and physical damage. Research has little understanding of how consumers make decisions about the veracity of online reviews, or incorporate online reviews into purchasing decisions, especially outside of the laboratory. Therefore, this study uses grounded theory approach to elaborate on how consumers determine the veracity and trustworthiness of online user reviews. Twenty-five interviews with consumers were held to identify deception cues, thought processes and other markers of online shopping behaviour. The results show that consumers use online reviews differently depending on context (e.g. product value, consumer knowledge). Additionally, the new theory proposes that consumers process reviews in at least two steps. First, they scan the review for relevance and then they determine the trustworthiness, credibility, and veracity. Additionally, this study identified different deception cues that are used. Together, these findings lead the way into a new understanding of human fake review detection online
Bacterial community dynamics during reclaimed water storage
No full textClimate change and industrialization necessitate a reassessment of water management strategies, particularly in agriculture, where reclaimed water supply often fails to meet irrigation needs. Storage can bridge supply gaps but raises concerns about water quality deterioration due to microbial changes and pathogen regrowth. This study examined microbial dynamics and regrowth during reclaimed water storage from a municipal wastewater treatment plant in Germany. The treatment train included ozonation, filtration and UV disinfection, and samples were analyzed using traditional culture methods for indicator organisms (e.g., Escherichia coli, Clostridium perfringens spores, and somatic coliphages) and 16S rRNA gene amplicon sequencing. Samples were collected throughout the treatment train and stored at 22 °C in the dark for up to 15 days. Results showed effective microbial reduction by treatment, with storage alone achieving similar declines in many cases. While treatment reduced bacterial diversity, storage gradually restored it, forming distinct microbial profiles from the original water quality. Bacterial communities converged during storage, suggesting a succession-like stabilization process. The findings highlight the dynamic nature of reclaimed water microbiomes and the importance of stimulating stable microbial communities to preserve water quality during storage. Advanced treatment should remove contaminants while supporting microbiomes that protect public health and the environment
Politik des Memes: Aspekte einer digitalen Medienästhetik
No full textDie folgenden Überlegungen gehen von einer bereits im Diskurs etablierten Auffassung des sogenannten Internet-Meme aus und versuchen gleichzeitig, diese nicht nur begrifflich zu schärfen, sondern zudem auch als spezifische medienkulturelle Praktiken neu zu diskutieren. Denn, wenn es sich dabei um (a) »eine Gruppe digitaler Einheiten« handelt, »die gemeinsame Eigenschaften im Inhalt, in der Form und/oder der Haltung aufweisen «, die (b) »in bewusster Auseinandersetzung mit anderen Memen erzeugt« sowie (c) »von vielen Nutzer[*innen] über das Internet verbreitet, imitiert und/oder transformiert wurden« (Shifman 2014: 16), dann greift diese Bestimmung – etwas – zu kurz. Eine weiterführende Konturierung des Begriffs Meme scheint hier, so unser Fokus, gegenwärtig zunächst besonders in Hinsicht auf die stark in Erscheinung tretende Verwendung dieses ›Bildkonzepts‹ in politischen Diskursen – beispielsweise zum Zweck politischer und/oder propagandistischer Ziele – näher relevant zu sein
Bayesian Inference for Fatigue Strength Estimation
No full textA vital material property of metals is long life fatigue strength. It describes the maximum load that can be cyclically applied to a defined specimen for a number of cycles that is thought to represent an infinite lifetime. The experimental measurement of long life fatigue strength is costly, justifying the need to create a precise estimate with as few experiments as possible. We propose a new approach for estimating long life fatigue strength that defines a ready-to-use experimental and analysis procedure. It relies on probabilistic machine learning methods, efficiently connecting expert knowledge about the material behavior and the test setup with historical and newly generated data. A comparison to state-of-the-art standard experimental procedures shows that our approach requires fewer experiments to produce an estimate at the same precision—massively reducing experimental costs
Type I interferon-mediated autoinflammation in two unrelated patients due to a proximal intronic splice site variant in DNASE2
No full textPurpose: Type I interferonopathies are Mendelian inborn errors of immunity caused by defective clearance or recognition of nucleic acids, resulting in chronic type I interferon (IFN) activation. DNase II is a lysosomal endonuclease critical for degrading DNA during erythropoiesis and apoptosis. Biallelic loss-of-function variants in DNASE2 cause a rare autoinflammatory disorder. We aimed to characterize the clinical, genetic, and functional impact of a novel DNASE2 splice site variant in two unrelated patients.
Methods: We performed exome and RNA sequencing to identify and validate variants. A minigene assay assessed splicing effects. DNase II activity was tested in cell lysates. Structural modeling, cytokine profiling, and immune stimulation assays were conducted to evaluate pathway activation and therapeutic response.
Results: Both patients carried a homozygous DNASE2 splice site variant (c.511 + 5G > A), resulting in exon 4 skipping and impaired DNase II activity. They presented at birth with rash, thrombocytopenia, and anemia, later developing neutropenia, arthritis, failure to thrive, and systemic inflammation. One patient also harbored a homozygous USP43 variant that reduced USP43 expression and enhanced IFN signaling. Both patients showed increased JAK-STAT activation and responded clinically to JAK1/2 inhibition with ruxolitinib.
Conclusion: We report a novel proximal intronic splice variant in DNASE2 associated with DNase II deficiency and type I interferon–mediated autoinflammation. Our findings expand the genotypic and phenotypic spectrum of this disorder, highlight the role of intronic variants in rare immune diseases, and support JAK inhibition as a targeted treatment approach