Photoproduction of pion pairs off nucleons

In the absence of a solution for Quantum Chromodynamics (QCD) in the low energy regime, so called effective models are being used to describe the nucleon and its excited states. These models include the basic symmetries from QCD, but on the other hand, compared to quarks and gluons, use higher lying degrees of freedom. Experimental contributions are mandatory to validate these models and fix free parameters. Today still most of the world-data in this field was obtained by meson-induced excitation of the nucleon. Even though numerous excited states of the nucleon could be identified, the number of model predicted states is much higher. This is known as the missing resonance problem. One explanation could be that some excited states just couple weakly to pion-N (kaon-N) and hence the excitation via photons was proposed to further test the model predictions. During the last 15 years, much experimental effort was made at various photoproduction facilities like MAMI, ELSA, JLab or ESRF and a large number of states could be confirmed, but the missing resonance problem could not be solved. Higher lying resonances (M > 1.6 GeV) decay preferably via sequential decays with many meson final states, and especially double pion decay channels are assumed to dominate in this region. The reactions investigated in this work, namely g+p(n)->pion^0+pion^0+p(n), g+n(p)->pion^0+pion^0+n(p), g+p->pion^0+pion^0+p, g+p(n)->pion^++pion^0+n(n), g+n(p)->pion^-+pion^0+p(p), g+p->pion^++pion^0+n thus form the primary source of information on photocouplings of higher lying resonances. This work explores neutral and mixed-charge double pion production channels up to invariant masses of the final state center-of-mass system of about 1.9 GeV and presents unpolarized as well as single-polarized observables. All results have high precision, are compared to different model predictions, and will considerably constrain future model analyses in the field of double pion photoproduction and beyond. The data of this work were taken at MAMI in four different experiments with liquid hydrogen and deuterium targets in 2007 and 2009 and include over 600 hours of beam time. A longitudinally polarized electron beam was used to produce circularly polarized bremsstrahlung photons with energies up 1.4 GeV. The reaction products, charged pions, photons and nucleons, were detected in the combined calorimeter consisting of Crystal Ball and TAPS. Total and differential cross sections, invariant mass distributions of N-pion and pion-pion and beam helicity asymmetries were computed in the fully reconstructed final state center-of-mass system. Effects from Fermi motion in the deuteron target could be reliably defolded leading to a good agreement between free and quasifree proton data, and thus the neutron results can be interpreted as a good approximation of free neutron data. Beam-helicity asymmetries for g+n(p)->pion^0+pion^0+n(p) and g+n(p)->pion^-+pion^0+p(p) have been measured for the first time and published together with the results from the proton data. Especially for the mixed-charge results, the available model calculations fail to reproduce the data, and for the neutral channel data, an unexpected similarity for proton and neutron results was observed. Total and differential cross sections as well as invariant mass distributions of N-pion and pion-pion for g+n(p)->pion^-+pion^0+p(p) have also been measured for the first time and previous results for g+p(n)->pion^++pion^0+n(n) could be reproduced and extended into the third resonance region

VLSI Implementierung eines parallelen Hough-Transformations-Prozessors mit dynamisch nachladbaren Mustern

In 1.0 5m CMOS Technik wurde ein Prozessor zur parallelen Verarbeitung einer speziellen Hough-Transformation entwickelt. Bei der auf 50 MHz ausgelegten Taktfrequenz koennen 6.4 x 10E+10 Objektmuster pro Sekunde detektiert werden. Bis zu 5 x 10E+7 zu detektierende Suchmuster koennen pro Sekunde in den Prozessor geladen werden. Damit koennen erstmals Echtzeitapplikationen in der Bildverarbeitung im Mikrosekundenbereich erschlossen werden

Sector coupling technologies in gas, electricity, and heat networks: Competition or synergy?

Current investment in distribution networks for electricity, gas, and heat is high, and the distribution networks play a prominent role in the necessary transformation of the energy system. This paper provides insights into the relationship between residential end-user decisions on heat supply and their effect on infrastructure planning. Therefore, the gas, electricity, and heat networks are analyzed together. After a review of the characteristics of the networks, the most common sector coupling technologies are compared economically and environmentally. The results show that, under the assumptions made, heat pumps are the cheapest option for residential end-users in the long run. This raises the question of whether a parallel development of three different infrastructures for the heat supply of buildings is the best path to a successful energy transition.Die derzeitigen Investitionen in die Verteilnetze für Strom, Gas und Wärme sind hoch und die Verteilnetze spielen eine bedeutende Rolle bei der notwendigen Transformation des Energiesystems. Diese Arbeit gibt Einblicke in den Zusammenhang zwischen Entscheidungen privater Endnutzer zur Wärmeversorgung und deren Auswirkungen auf die Infrastrukturplanung. Dafür werden die Gas-, Strom- und Wärmenetze gemeinsam analysiert. Nach einem Überblick über die Charakteristika der Netze werden die gängigsten Sektorkopplungstechnologien ökonomisch und ökologisch verglichen. Die Ergebnisse zeigen, dass unter den getroffenen Annahmen Wärmepumpen langfristig die kostengünstigste Option für private Endnutzer sind. Dies wirft die Frage auf, ob eine parallele Entwicklung von drei verschiedenen Infrastrukturen zur Wärmeversorgung von Gebäuden der beste Weg hin zu einer erfolgreichen Energiewende ist

SmartWeb: Mobile Access to the Semantic Web

Ankolekar A, Cimiano P, Hitzler P, et al. SmartWeb: Mobile Access to the Semantic Web. In: Wache H, ed. Proceedings of the ESWC2006 poster and demo session. 2006: 3-4

Immortality of the soul as an intuitive idea: towards a psychological explanation of the origins of afterlife beliefs

This study tried to investigate if intuitive ideas about the continuation of the Self after death determine the way people represent the state of being dead, and, in this way, investigate possible psychological origins of afterlife beliefs, which constitute a recurrent cultural phenomenon. A semi-structured interview and a self-report questionnaire were used to obtain information on the experience of imagining oneself as dead and the representation of the dead-I of young adults. he results suggest that (1) there is a tendency to imagine the state of being dead as a continuation of the I, even in the absence of explicit afterlife beliefs; (2) perceptual, emotional, epistemic and desire experiences are associated to the dead-I; (3) the representation of the dead-I seems to be determined by an interaction between cognitive processes related to self-awareness and theory of mind, and the cultural afterlife beliefs explicitly learned. A previous alternative hypothesis, suggesting that simulation constraints were responsible for the emergence of non-reflective afterlife concepts (Bering, 2002, 2006) is not completely supported by our results. he data presented here suggest that immortality of the soul might be an intuitive religious concept, connected to the experience of the Self and to the implicit theorization that the experienced Self is independent from the body. Future studies should focus on the collection of cross-cultural and developmental data

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

PatternFinder Konzept

Patterns sind bewährte Lösungsmuster zu wiederkehrenden Problemstellungen. Im Bereich User Interface Design (UI Design) existieren viele solche Lösungsmuster. Die Erkenntnisse der Ist-Situationsanalyse sind überraschend: Gibt es doch unzählige UI Patterns (über 1000 wurden gefunden) und trotzdem kennen die Leute die das Design machen nicht ein einziges. Einerseits sind die Patterns in Literatur und Internet weit verstreut und es fehlt an geeigneter Unterstützung bei der Suche. Die UI Patterns bleiben so meist unbekannt und ungenutzt. Andererseits wird das UI Design bei Businessapplikationen oft nebenbei gemacht - von Leuten die nie in UI Design ausgebildet worden sind und sich vorallem auf ihre Erfahrung mit Applikationen stützen und so intuitiv eigene „falsche“ Patterns verwenden. Im Rahmen dieser Masterarbeit wurde ein Konzept entwickelt, welches aufzeigt, wie UI Patterns organisiert und aufbereitet werden können, um sie für UI Designer besser zugänglich zu machen, ohne sich erst vertieft mit der Materie auseinandersetzen zu müssen. Der im PatternFinder Konzept beschriebene Ansatz verwendet den gewohnten Entwicklungsprozess des jeweiligen Unternehmen als Einstieg. So wird ein aufgabenorientierter Zugang zu den Patterns ermöglicht. Um in der jeweiligen Projektphase passende Patterns zu finden, werden diese nicht einer (zB. abstrakten Ordnungs-) Struktur zugeordnet, sondern die Pattern werden mit anwenderspezifischen Begriffen (Tags für Problem und Lösung) charakterisiert. Die durch die Tags dynamisch entstehenden Verbindungen ermöglichen eine Navigation zu verwandten oder ähnlichen Patterns. Wird nun ein konkretes Problem ebenso charakterisiert, so lassen sich über dessen Begriffe entsprechende Pattern finden. Wenn Patterns einfach gefunden und angewendet werden, steigert dies die Qualität und Effizienz beim UI Design. Auch Designentscheide werden dadurch nachvollziehbarer und die Kommunikation im Projekt wird vereinfacht: Alle verstehen das Gleiche und es ist benennbar. All dies bringt somit auch einen wirtschaftlichen Nutzen

Untersuchung zum Nutzen zusätzlicher Testverfahren in Deutschland für die Sicherheit von Blutkomponenten und Blutprodukten

Das Paul-Ehrlich-Institut (PEI) hat zwischen 1999 und 2006 in Deutschland ergänzend zu den Standardtestverfahren von Blutspenden drei weitere Suchtests (auf HCV- und HIV-1-Genom, anti-HBc-Antikörper) verpflichtend eingeführt. Um den Nutzen der Einführung der einzelnen Suchtests zu bewerten, wurde eine Umfrage bei allen Blutspendeeinrichtungen durchgeführt und anschließend wurden die Ergebnisse der Suchtests für den Zeitraum 2008 bis 2015 ausgewertet. Im folgenden Beitrag werden die wichtigsten Ergebnisse vorgestellt

Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building

Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m3 (inter-quartile range = IQR 1–4), and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m3 (IQR 26–126) in summer and 9 spores/m3 (IQR 6–15) in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m3). This variability may explain the variability of study results in the literature