A Novel Framework for Simulating Computing Infrastructure and Network Data Flows Targeted on Cloud Computing

Understanding how computing infrastructure decisions influence overall performance and cost can be very difficult. Simulation techniques are an important tool to help analyse and evaluate different infrastructure configurations and deployment scenarios. As diversity of cloud computing resources is growing, the space of possible infrastructure configurations becomes larger and finding the best solution becomes harder. In our previous paper, we presented a framework to benchmark cloud resources to obtain objective and comparable results. Based on those results, our simulation framework allows to model applications and to estimate their performance. Compared to other infrastructure or cloud simulation tools our framework excels when it comes to the simulation of network data flows

Optimized management of urolithiasis by coloured stent-stone contrast using dual-energy computed tomography (DECT)

Background We analysed in vitro the appearance of commonly used ureteral stents with dual-energy computed tomography (DECT) and we used these characteristics to optimize the differentiation between stents and adjacent stone. Methods We analysed in vitro a selection of 36 different stents from 7 manufacturers. They were placed in a self-build phantom model and measured using the SOMATOM® Force Dual Source CT-Scanner (Siemens, Forchheim, Germany). Each sample was scanned at various tube potentials of 80 and 150 peak kilovoltage (kVp), 90 and 150 kVp and 100 and 150 kVp. The syngo Post-Processing Suite software program (Siemens, Forchheim, Germany) was used for differentiation based on a 3–material decomposition algorithm (UA, calcium, urine) according to our standard stone protocol. Results Stents composed of polyurethane appeared blue and silicon-based stents were red on the image. The determined appearances were constant for various peak kilovoltage (kVp) values. The coloured stent-stone-contrast displayed on DECT improves monitoring, especially of small calculi adjacent to indwelling ureteral stents. Conclusion Both urinary calculi and ureteral stents can be accurately differentiated by a distinct appearance on DECT. For the management of urolithiasis patients can be monitored more easily and accurately using DECT if the stent shows a different colour than the adjacent stone

Tests von Modellen mit höherdimensionalen effektiven Operatoren am LHC und Experimenten zur Suche dunkler Materie

Dark matter and non-zero neutrino masses are possible hints for new physics beyond the Standard Model of particle physics. Such potential consequences of new physics can be described by effective field theories in a model independent way. It is possible that the dominant contribution to low-energy effects of new physics is generated by operators of dimension d>5, e.g., due to an additional symmetry. Since these are more suppressed than the usually discussed lower dimensional operators, they can lead to extremly weak interactions even if new physics appears at comparatively low scales. Thus neutrino mass models can be connected to TeV scale physics, for instance. The possible existence of TeV scale particles is interesting, since they can be potentially observed at collider experiments, such as the Large Hadron Collider. Hence, we first recapitulate the generation of neutrino masses by higher dimensional effective operators in a supersymmetric framework. In addition, we discuss processes that can be used to test these models at the Large Hadron Collider. The introduction of new particles can affect the running of gauge couplings. Hence, we study the compatibilty of these models with Grand Unified Theories. The required extension of these models can imply the existence of new heavy quarks, which requires the consideration of cosmological constraints. Finally, higher dimensional effective operators can not only generate small neutrino masses. They also can be used to discuss the interactions relevant for dark matter detection experiments. Thus we apply the methods established for the study of neutrino mass models to the systematic discussion of higher dimensional effective operators generating dark matter interactions.Dunkle Materie und nichtverschwindende Neutrinomassen sind nur zwei Hinweise auf das mögliche Vorhandensein neuer Physik jenseits des Standardmodells der Teilchenphysik. Solche möglichen Konsequenzen neuer Physik können modellunabhängig mit effektiven Feldtheorien beschrieben werden. Beispielsweise aufgrund zusätzlicher Symmetrien ist es möglich, dass Operatoren mit Dimension $d>5$ den dominanten Beitrag zu den Effekten neuer Physik bei niedrigen Energieskalen liefern. Da diese stärker unterdrückt sind als die gewöhnlicherweise betrachteten Operatoren niedrigerer Dimension, können sie zu äußerst schwachen Wechselwirkungen führen, selbst wenn neue Physik bereits bei vergleichsweise niedrigen Energien auftritt. Dies ermöglicht unter anderem neue Teilchen mit Massen im Bereich der TeV-Skala mit der Erzeugung der sehr geringen Neutrinomassen in Verbindung zu bringen. Solche Teilchen sind besonders interessant, da sie an Beschleunigerexperimenten wie dem Large Hadron Collider untersucht werden können. Deswegen wird in dieser Arbeit zunächst die Erzeugung von Neutrinomassen durch höherdimensionale effektive Operatoren in supersymmetrischen Modellen rekapituliert. Darüber hinaus sollen mögliche Prozesse zum Nachweis dieser Modelle am Large Hadron Collider anhand eines Beispiels diskutiert werden. Da das Einführen neuer Teilchen das Laufen der Kopplungskonstanten beeinflussen kann, wird ferner betrachtet, inwiefern solche Szenarien vereinbar mit großen vereinheitlichten Theorien (Grand Unified Theories) sind. Die entsprechende Erweiterung dieser Modelle kann beispielsweise das Auftreten neuer schwerer Quarks zur Folge haben, die auf ihre Vereinbarkeit mit kosmologischen Beobachtungen untersucht werden. Höherdimensionale Operatoren können jedoch nicht nur sehr kleine Neutrinomassen erzeugen, sondern auch für Experimente zum Nachweis dunkler Materie relevant sein. Daher sollen die zuvor angewandten Methoden zur systematischen Diskussion effektiver Operatoren, die Wechselwirkungen dunkler Materie beschreiben, verwendet werden

The rapid spread of early farming from the Aegean into the Balkans via the Sub-Mediterranean-Aegean Vegetation Zone

Close examination of the geographic position of Early Neolithic settlements in SE-Europe shows that the oldest sites are almost exclusively situated in some very specific biogeographic areas. These earliest Neolithic settlements are all concentrated in a region that Pavle Cikovac calls the Sub-Mediterranean-Aegean biogeographic region. It covers the northern and north-western edge of the Aegean, including Thessaly, Greek Macedonia and Greek Thrace, and extends further into the Balkans, but only along the valleys of the Vardar (Axios), Struma (Strymon) and Mesta (Nestos) rivers. Surprisingly, although Thrace is the closest landscape to Anatolia, it does not contain any sites of the earliest phase of the Neolithic at all beyond the narrow zone of the northern Marmara. In the present paper we explain this remarkable situation in terms of the natural environment in this particular region of the southern Balkans. To begin, we propose that the lack of oldest Early Neolithic settlements in Thrace is related to the extreme microclimate of this region. As shown by modern vegetation analogues, Thracian oriental hornbeam-downy oak forests are exposed to stronger continental influence with frosts in the winter and average temperatures during the coldest months that are ca. 2–3 °C lower than those in the Central Balkans that have Sub-Mediterranean vegetation. In general terms, what we may expect is that the earliest Neolithic groups would first appear in regions with similarly mild conditions, on a yearly average, to those in the Mediterranean. Such mild conditions are indeed present in the Sub-Mediterranean biogeographic region. On the other hand, before moving further to the north along the north-south oriented river systems of the Central Balkans, the Neolithic economy based on agriculture and stockbreeding would first have to be adapted to the relatively harsh winters in the Balkans. In consequence, it would have been possible to apply the new Neolithic lifestyle in the neighbouring areas of Thrace, Walachia, Dobrudža and the Carpathian Basin only after a certain period of adaptation. Available 14C-data show that the adaptation period is identical to the time-span of Rapid Climate Change (RCC: 6550-6050 calBC) as defined in previous studies.status: publishe

Engagement und Diversität: Frank-Rutger Hausmann zum 75. Geburtstag

Einleitung der Herausgeber zum Beihef