Spin Physics at COMPASS

The COMPASS experiment is a fixed target experiment at the CERN SPS using muon and hadron beams for the investigation of the spin structure of the nucleon and hadron spectroscopy. The main objective of the muon physics program is the study of the spin of the nucleon in terms of its constituents, quarks and gluons. COMPASS has accumulated data during 6 years scattering polarized muons off a longitudinally or a transversely polarized deuteron (6LiD) or proton (NH3) target. Results for the gluon polarization are obtained from longitudinal double spin cross section asymmetries using two different channels, open charm production and high transverse momentum hadron pairs, both proceeding through the photon-gluon fusion process. Also, the longitudinal spin structure functions of the proton and the deuteron were measured in parallel as well as the helicity distributions for the three lightest quark flavors. With a transversely polarized target, results were obtained with proton and deuteron targets for the Collins and Sivers asymmetries for charged hadrons as well as for identified kaons and pions. The Collins asymmetry is sensitive to the transverse spin structure of the nucleon, while the Sivers asymmetry reflects correlations between the quark transverse momentum and the nucleon spin. Recently, a new proposal for the COMPASS II experiment was accepted by the CERN SPS which includes two new topics: Exclusive reactions like DVCS and DVMP using the muon beam and a hydrogen target to study generalized parton distributions and Drell-Yan measurements using a pion beam and a polarized NH3 target to study transverse momentum dependent distributions.Comment: Proceedings of the Rutherford conference, Manchester, August 2011. Changes due to referees comments implemente

Assessment of the Antigen-presenting Function of murine B cells in vivo: Induction of anti-Tumour-Immunity

B cells have mainly been recognized for their antibody-secreting function in humoral immune responses. Lately, the focus of interest has moved to the antibody-independent functions of B cells. In that context, it has become clear that antigen presentation by B cells is critically involved in both physiologic immune responses as well as pathologic immune reaction such as autoimmune diseases. Antigen presentation by B cells is characterised by their ability to take-up, process and present antigen via MHC-II in a B cell receptor dependent and independent fashion. Furthermore, during immune responses armed helper T cells interact with B cells by expression of CD40 Ligand (CD40L), which thereby become activated and in turn start to proliferate and differentiate. CD40-activated B cells (CD40-B) are professional antigen-presenting cells comparable to dendritic cells (DC) exhibiting a high expression of costimulatory and MHC molecules. CD40-B cells were shown to not only prime naïve CD4+ and CD8+ T cells effciently, but also expand memory T cells in vitro. Furthermore they express the full lymph node homing triad (CD62L, CCR7/CXCR4 and LFA-1) and were shown to induce T-cell chemotaxis in vitro. Recently, we demonstrated that murine CD40B cells (mCD40B) specifically migrate to secondary lymphoid organs in vivo. Importantly, these cells are available at virtually unlimited amounts at a purity > 95% for high-dose, high-frequency vaccination considered crucial for the control of cancer. However, most B cell-based vaccines tested so far failed to induce functional and protective cytotoxic T lymphocyte (CTL) re- sponses in animal models in vivo. Within this work I present the successful development of a functional murine mCD40B-based vaccination model. This model is indeed suitable to study the ability of mCD40B cells to induce protective anti-tumour responses in vivo. We established a murine B-cell stimulation system based on potent B-cell activation maintained by co-cultivation with membrane-bound CD40 ligand and interleukin-4. By using this technique highly activated mCD40Bs expand more than 5-fold with purity above 90% within 14 days. Hence, we identifed appropriate mCD40B subsets and further characterised them on a functional level. Despite their T-cell stimulatory capacity in vitro being inferior to murine dendritic cell (mDC) subsets, we demonstrated that vaccination with antigen-loaded mCD40B effectively induces specifc CTL responses against viral and model peptide antigen in vivo. We clearly identifed injection route, cell dose and vaccination repetitions as parameters exerting dominant infuence on the effective induction of specifc T cell responses by mCD40B. Incorporating these parameters into the vaccination algorithm, I showed that mCD40B induce in vivo cytolysis of antigen-specific target cells comparable to mDC. Finally, by using tumour antigen-loaded mCD40B we successfully transferred our vaccination algorithm to preventive immunization against B16 melanoma. In summary, highly activated mCD40B cells indeed exhibit antigen-presenting capacity sufficient to induce protective anti-tumour immunity in B16 melanoma

Neural correlates of affective contributions to lexical decisions in children and adults

The goal of the present study was to investigate whether 6–9-year old children and adults show similar neural responses to affective words. An event-related neuroimaging paradigm was used in which both age cohorts performed the same auditory lexical decision task (LDT). The results show similarities in (auditory) lexico-semantic network activation as well as in areas associated with affective information. In both age cohorts’ activations were stronger for positive than for negative words, thus exhibiting a positivity superiority effect. Children showed less activation in areas associated with affective information in response to all three valence categories than adults. Our results are discussed in the light of computational models of word recognition, and previous findings of affective contributions to LDT in adults

Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions

Hybrid continuous-discontinuous sheet molding compound (SMC) composites are considered suitable candidates for structural automotive applications, due to their high mass-specific mechanical properties combined with high geometrical flexibility and low costs. Since structural automotive parts are subject to repeated loading, profound knowledge of their fatigue behavior is required. This paper presents an experimental study on the bending fatigue behavior of hybrid SMC with discontinuous glass fibers in the core and unidirectional continuous carbon fibers in the face layers. Effects of hybridization on the S-N behavior and stiffness degradation have been analyzed in constant amplitude fatigue tests under 3-point bending load at different temperatures and frequencies. Microscopic investigations on polished specimen edges were used to study the damage behavior. The ultimate flexural strength at quasi-static (UFSS) and fatigue strain rate (UFSF) of the hybrid composite was 54 % and 59 % higher than that of discontinuous SMC, respectively. In contrast, the flexural fatigue strength at 2.6⋅106 cycles increased by 258 %. The relative stiffness degradation of the hybrid composites was smaller during most of their fatigue lives due to the continuous carbon fiber reinforcement. The carbon fiber ply on the compression loaded side was the first ply to fail. Fatigue stress significantly decreased at 80 °C due to early kinking of the continuous carbon fiber-reinforced ply on the compression loaded side. Variation of frequency had no significant effect on the fatigue behavior of both discontinuous and continuous-discontinuous SMC

Fatigue behavior of hybrid continuous-discontinuous fiber-reinforced sheet molding compound composites under application-related loading conditions

Hybrid continuous-discontinuous sheet molding compound (SMC) composites are considered suitable candidates for structural automotive applications, due to their high mass-specific mechanical properties combined with high geometrical flexibility and low costs. Since structural automotive parts are subject to repeated loading, profound knowledge of their fatigue behavior is required. This paper presents an experimental study on the bending fatigue behavior of hybrid SMC with discontinuous glass fibers in the core and unidirectional continuous carbon fibers in the face layers. Effects of hybridization on the S-N behavior and stiffness degradation have been analyzed in constant amplitude fatigue tests under 3-point bending load at different temperatures and frequencies. Microscopic investigations on polished specimen edges were used to study the damage behavior. The ultimate flexural strength at quasi-static (UFS$^S$) and fatigue strain rate (UFS$^F$) of the hybrid composite was 54 % and 59 % higher than that of discontinuous SMC, respectively. In contrast, the flexural fatigue strength at 2.6⋅10S$^6$ cycles increased by 258 %. The relative stiffness degradation of the hybrid composites was smaller during most of their fatigue lives due to the continuous carbon fiber reinforcement. The carbon fiber ply on the compression loaded side was the first ply to fail. Fatigue stress significantly decreased at 80 °C due to early kinking of the continuous carbon fiber-reinforced ply on the compression loaded side. Variation of frequency had no significant effect on the fatigue behavior of both discontinuous and continuous-discontinuous SMC

Justice Evaluation of the Income Distribution (JEID): Development and validation of a short scale for the subjective assessment of objective differences in earnings

Justice evaluations are proposed to provide a link between the objective level of inequality and the consequences at the individual and societal level. Available instruments, however, focus on the subjective perception of inequality and income distributions. In light of findings that subjective perceptions of inequality and income levels can be biased and subject to method effects, we present the newly developed Justice Evaluation of the Income Distribution (JEID) Scale, which captures justice evaluations of the actual earnings distribution. JEID comprises five items that provide respondents with earnings information for five groups at different segments along the distribution of earnings in a given country. We provide a German-language and an English-language version of the scale. The German-language version was developed and validated based on three comprehensive heterogeneous quota samples from Germany; the translated English-language version was validated in one comprehensive heterogeneous quota sample from the UK. Using latent profile analysis and k-means clustering, we identified three typical response patterns, which we labeled “inequality averse,” “bottom-inequality averse,” and “status quo justification.” JEID was found to be related to normative orientations in the sense that egalitarian views were associated with stronger injustice evaluations at the bottom and top ends of the earnings distribution. With a completion time of between 1.50 and 2.75 min, the JEID scale can be applied in any self-report survey in the social sciences to investigate the distribution, precursors, and consequences of individuals’ subjective evaluations of objective differences in earnings

Single Track Performance of the Inner Detector New Track Reconstruction (NEWT)

In a previous series of documents we have presented the new ATLAS track reconstruction chain (NEWT) and several of the involved components. It has become the default reconstruction application for the Inner Detector. However, a large scale validation of the reconstruction performance in both efficiency and track resolutions has not been given yet. This documents presents the results of a systematic single track validation of the new track reconstruction and puts it in comparison with results obtained with different reconstruction applications

Midseason Stalk Breakage in Corn As Affected by Crop Rotation, Hybrid, and Nitrogen Fertilizer Rate

In July of 1993 and 1994, southern Nebraska experienced devastating windstorms, with winds estimated to exceed 45 m s-1. These storms resulted in severe brittle-snap of corn (Zea mays L.), with stalks breaking near the primary ear node in the basal portion of an elongating internode. In the storm path were several experiments established on a Hord silt loam (Cumulic Haplustolls) to determine the effect of selected management practices (crop rotation, hybrid selection, planting date, and N fertilization) on nitrate leaching to ground water from irrigated cropland. After the storms, the number of broken plants was determined in these experiments to evaluate how management practices influenced severity of the damage. In 1993, crop rotation, hybrid, planting date, and N fertilization, and their interactions, all affected the amount of brittle-snap. Treatments that resulted in more rapid growth (optimum to excess N rates, corn rotated with soybean [Glycine max (L.) Merr.], and early planting) increased the severity of damage. In continuous corn, 7% of the plants broke, compared with 33% for rotated corn; damage ranged from 4 to 33% among hybrids; and percent broken plants increased quadratically, from 8% for the 0 kg N ha-1 treatment to 24% at N rates equal to or greater than 80 kg N ha-1. Only the hybrid factor was significant in 1994. Amount of brittle-snap was related to stage of development (r = 0.55, n = 160, P \u3c 0.001). The great difference in severity of damage among hybrids indicates that the current best management strategy to limit brittle-snap losses is to plant hybrids less prone to breakage. Alternative management strategies, such as late planting, suboptimal N rates, and continuous cropping of corn, all are known to limit yield regardless of windstorms. There is a need for greater knowledge of cell and tissue characteristics that render hybrids susceptible or resistant to brittle-snap. Also, methods for simulating brittlesnap are needed to foster effective selection for resistant lines in breeding programs