Longitudinally Polarized Photoproduction of Inclusive Hadrons at Fixed-Target Experiments

We present a detailed phenomenological study of spin-dependent single-inclusive high-p_T hadron photoproduction with particular emphasis on the kinematics relevant for the Compass and Hermes fixed-target experiments. We carefully examine the theoretical uncertainties associated with the only moderate transverse momenta accessible in such measurements and analyze the sensitivity of the relevant spin asymmetries to the gluon polarization in the nucleon as well as to the completely unknown parton content of circularly polarized photons.Comment: 12 pages, 14 figures; final version to appear in EPJC; comparison to E155 data and references adde

The Governance of International Nongovernmental Organizations: How Funding and Volunteer Involvement Affect Board Nomination Modes and Stakeholder Representation in International Nongovernmental Organizations

The governance of civil society organizations (CSOs) is a crucial determinant of organizational legitimacy, accountability, and performance. International nongovernmental organizations (INGOs) are a subtype of CSOs and have received a lot of attention as actors in global governance. Research suggests that INGOs can follow a membership model, where the board is elected by the membership, or a board-managed model, where the board is appointed to represent major stakeholders. Following resource dependency theory, we argue that the choice between these two models depends on the INGOs different sources of funding and the degree of volunteer involvement: As donors and volunteers provide important resources, they are in turn granted the right to nominate board members or to sit on the board. In our quantitative study we show that individual members, regional member organizations, and governmental donors hold a stronger position in the governance of INGOs than philanthropists, foundations and volunteers. Our results inform research on CSO governance by highlighting the relevance of board nomination modes and by showing how CSOs can incorporate stakeholders into their governance mechanism

Pi0 and Eta measurement with photon conversions in ALICE in proton-proton collisions at sqrt(s) = 7 TeV

We present a measurement of the Pi0 transverse momentum spectrum and of the Eta/Pi0 ratio in proton-proton collisions at sqrt(s) = 7 TeV at the CERN LHC. In this analysis the reconstruction of Pi0 and Eta mesons has been done via photon conversions in the central tracking system of ALICE. Therefore, this method is completely independent from the electromagnetic calorimeters. It makes the Pi0 (Eta) measurement possible down to pt = 0.4 (0.6) GeV/c with a very good resolution and a very small background. For 100 Mio. pp collisions the pt reach is 7 GeV/c. The results are compared to NLO pQCD calculations.Comment: Proceedings to talk at HardProbes 2010, 4 page

A social psychological concept of normality: an examination of the emergence, perpetuation and shift of unnoticed standards, and their influence on behavior and social dynamics

This dissertation examines the influence of normality perceptions and shifts of normality perceptions on individuals attitudes and behaviors. A social psychological concept of normality was developed and stated in a model of normality and a model of shifts of normality, based on diverse research lines (such as norm theory, research on the status quo, naive realism, shared reality and social norms research). The underlying mechanisms of the models were examined in seven quantitative studies in heterogenous study fields. The model of normality illustrates the process of emergence and development of stimuli and events as normal; a key aspect of the model being the deductions drawn by individuals from normality to normativity and objective reality. The model of shifts of normality contributes to explaining how the scope of normality can gradually move and be extended towards the extreme. In Study 1 and 2, the emergence, shift, and influence of normality in social settings were examined. Study 1 was embedded in the simulation of a UN General Assembly, and Study 2 was set in the context of the German federal election 2013. In Study 3, shifts of perceptions of groups normality were examined. The study was implemented via an integration-fostering mentorship program and the ingroup projection model was used as a theoretical framework. Studies 4 to 7 form the core element of the empirical section, examining the effect of social norms on reality perceptions in the domain of prejudice. The studies show that whichever prejudice is congruent to the group norms is perceived as true, objective and real, and hence not identified as prejudice. Nonnormative prejudices, in contrast, are perceived to be faulty and resulting from biased perceptions. These results question the widespread concept of prejudice as reflecting bias and underline the necessity to examine the basic processes. All seven studies are discussed with regard to the two models and their practical implications

QCD Spin Physics: Partonic Spin Structure of the Nucleon

We discuss some recent developments concerning the nucleon's helicity parton distribution functions: New preliminary data from jet production at RHIC suggest for the first time a non-vanishing polarization of gluons in the nucleon. SIDIS measurements at COMPASS provide better constraints on the strange and light sea quark helicity distributions. Single-longitudinal spin asymmetries in W-boson production have been observed at RHIC and will ultimately give new insights into the light quark and anti-quark helicity structure of the nucleon.Comment: Talk presented at the "International School of Nuclear Physics, 33rd Course: From Quarks and Gluons to Hadrons and Nuclei", Erice, Italy, 16 - 24 September 2011; 12 pages, 9 figure

An algebraic characterization of the Weyl curvature of S m × S m

In der vorliegenden Arbeit wird die Eigenwertgleichung W2+W#=θW, die in enger Beziehung zur Evolutionsgleichung von Krümmungsoperatoren unter dem Ricci Fluss steht, für Weyl Krümmungsoperatoren W untersucht. Es wird bewiesen, dass θ unter gewissen Bedingungen genau dann maximal ist, falls W die Weyl Krümmung von Sm×Sm ist. Desweitern werden unendliche Serien von neuen Lösungen dieser Eigenwertgleichung konstruiert.In the present work, the eigenvalue equation W2+W#=θW, which is closely related to the evolution equation of a curvature operator under the Ricci flow, is analyzed for Weyl curvature operators W. A proof that under certain conditions θ is maximal if and only if W is the Weyl curvature of Sm×Sm is given. Moreover, infinite series of new solutions to this eigenvalue equation are constructed

Effect of polarized gluon distribution on spin asymmetries for neutral and charged pion production

A longitudinal double spin asymmetry for \pi^0 production has been measured by the PHENIX collaboration. The asymmetry is sensitive to the polarized gluon distribution and is indicated to be positive by theoretical predictions. We study a correlation between behavior of the asymmetry and polarized gluon distribution in neutral and charged pion production at RHIC.Comment: 7 pages, 5 eps figures, section added, typos corrected. to be published in PR

Development of a Safe Powertrain System Architecture for the HorizonUAM Air Taxi Concept

The German Aerospace Center project HorizonUAM encompasses numerous research areas regarding urban air mobility. Whithin this context, this presentation aims to explain the design process for deriving a safe all-electric multirotor propulsion system for one of the HorizonUAM air taxi concepts. The main challenges for the multirotor propulsion system are the highly demanding certification requirements, especially in terms of system reliability, which are laid down within the means of compliance of the EASA SC-VTOL. Using a model-based systems engineering design approach which follows the safety design methods of ARP4761, different multirotor propulsion system architectures were iteratively developed, analyzed and further optimized to meet the required system reliabilities. The result of one proposed powertrain propulsion architecture, incorporating 4 main rotors and two push propellers, is presented herein. In addition to the powertrain architecture design each powertrain component, like the electric motor, the motor controller as well as a gearbox, was sized and compared with current state of the art technology. To verify the dynamic behavior of the whole powertrain a simulation model was set up. It could be shown that the powertrain can be build up using currently commercially available components and that the rotor reaction times seem to be acceptable. However, due to the low rotational speeds of the rotors, it is highly advisable not to use a direct drive but rather a gearbox to avoid high thermal losses. In the next future step, the different system models, which were implemented will be integrated to achieve a holistic integrated system model

System Design Results for an Air Taxi Concept in HorizonUAM

Onboard systems such as flight controls, power supply and avionics are an integral part of the air taxi concept being studied in the HorizonUAM project. The aim of this presentation is to give an overview of the current status of the system design. A special focus has been on the full-electric flight control system containing the powertrain components and the power supply system including the thermal management. Based on a multirotor configuration with four main rotors and two push propellers, a safe powertrain architecture was developed and the associated components dimensioned. Simulation models were used to check the dimensioning results and to study the general dynamic behaviour of the mechanical and electrical components. Three different electrical power supply variants were examined: a battery-operated power supply, a fuel cell-based power supply and a hybrid-electric power supply based on both a battery and fuel cell system. Cooling concepts were successfully developed and analysed for these three power supplies. The system design results for the flight control and power supply were achieved in different parallel design streams. The basic feasibility of each system design was verified in each associated design stream. Although attempts have been made to make the same assumptions, this has not always been possible. Thus, the different system designs and models will be integrated and harmonized to achieve fully consistent design results in a future step

Randomized controlled trial of S-1 maintenance therapy in metastatic esophagogastric cancer – the multinational MATEO study

Background: The optimal duration of firstline chemotherapy in metastatic esophagogastric cancer is unknown. In most clinical trials therapy was given until tumour progression or limiting toxicity. Maintenance concepts aiming to prolong the duration of response and maintain quality of life have been established in other tumour types but not in esophagogastric cancer. S-1 is an oral fluoropyrimidine with proven efficacy in metastatic esophagogastric cancer. Methods: The Maintenance Teysuno® (S-1) in esophagogastric cancer (MATEO) trial is a multinational, randomized phase II study that explores the role of S-1 maintenance therapy in Her-2 negative, advanced esophagogastric adenocarcinoma. After a 12-week firstline platinum-fluoropyrimidine-based chemotherapy patients without tumour progression are randomized in a 2:1 allocation to receive S-1 alone or continue with the same regimen as during the primary period. The primary endpoint is overall survival. Secondary endpoints include safety and toxicity, progression-free survival and quality of life. Correlative biomarker analyses focus on the identification of a subgroup of patients with a prolonged benefit from S-1 based maintenance therapy. Discussion: MATEO will be the first trial to define the role of a S-1 based maintenance therapy in patients having received a platinum-based firstline chemotherapy. Trial registration: NCT02128243 (date of registration: 29–04-2014)