Exploring Nucleon Spin Structure in Longitudinally Polarized Collisions

We review how RHIC is expected to deepen our understanding of the spin structure of longitudinally polarized nucleons. After briefly outlining the current status of spin-dependent parton densities and pointing out open questions, we focus on theoretical calculations and predictions relevant for the RHIC spin program. Estimates of the expected statistical accuracy for such measurements are presented, taking into account the acceptance of the RHIC detectors.Comment: 10 pages, 7 figures, uses aipproc style, invited talk presented at the 15th International Spin Physics Symposium 'SPIN 2002', Sept. 9-14 2002, Brookhaven National Laboratory, Upton, N

Transcriptional control of the H-NS antagonists LeuO and RcsB-BglJ in Escherichia coli

The bacterial nucleoid-associated protein (NAP) H-NS is involved in the organization and compaction of the bacterial chromatin and acts as a global respressor, mainly of genes that have been acquired by horizontal gene transfer and that are related to stress responses and pathogenicity. Binding of H-NS to the DNA and formation of a nucleoprotein complex at promoter regions leads to repression. This repressor effect of H-NS can be antagonized by gene-specific transcription factors (H-NS antagonists) that activate transcription of H NS-repressed genes by competing with H-NS for binding or by disturbing formation of the nucleoprotein complex. Two examples of such H NS antagonists are the LysR-type transcription factor LeuO and the FixJ/NarL-type transcription factor heterodimer RcsB-BglJ. LeuO is a pleiotropic regulator of stress responses and virulence determinants. RcsB-BglJ activates transcription of the H NS-repressed bgl (aryl-β,D-glucoside) operon. In this work, novel targets of RcsB-BglJ were identified in Escherichia coli by microarray analyses. The results suggest that heterodimerization of RcsB and BglJ is essential for regulation. Further, in addition to genes related to unknown or predicted function in the membrane the leuO gene was identified as a target gene. Detailed analysis of transcriptional regulation of leuO demonstrated that RcsB-BglJ strongly activates transcription of leuO by binding proximal to a newly mapped leuO promoter. Thus RcsB-BglJ antagonizes repression of leuO by H-NS and the H-NS-like protein StpA. Additional data presented here show that LeuO negatively autoregulates its own expression and inhibits activation of leuO by RcsB-BglJ. Regulation of leuO by RcsB-BglJ and autoregulation by LeuO, as shown here, as well as activation of bglJ by LeuO, as published previously, indicates a feedback control mechanism of two global transcriptional regulators and H-NS antagonists.This feedback regulation may ensure turn on of their expression in response to specific environmental signals. Screens to search for novel regulators or upstream signals were performed by transposon mutagenesis and by using a genomic expression library. These screens indicate that additional factors may be involved in the regulation of this leuO-bglJ feedback loop

Tainted Money? Contribution Limits and the Effectiveness of Campaign Spending

Campaign expenditures are not effective in increasing candidates’ vote shares if voters do not respond to the advertisement when they believe that campaign expenditures are financed with “tainted money.” In this situation, limiting contributions may reduce the number of policy favors that candidates promise to contributors, and thereby increase the effectiveness of campaign spending. Exploiting cross-state variation in campaign finance laws, this paper tests whether campaign expenditures by state House candidates are more productive in increasing vote shares when candidates run in states that limit contributions. The results show that campaign expenditures by incumbents, challengers, and open seat candidates are more productive when candidates run in states with campaign contribution limits, as opposed to in states without limits. Controlling for the endogeneity of incumbent spending, the study shows that in states with contribution limits, incumbent spending and challenger spending are equally productive, and that spending by both candidates is quantitatively important in increasing their vote shares.

Do Strict Electoral Campaign Finance Rules Limit Corruption?

Wahlkampffinanzierung, Parteienfinanzierung, Korruption, Österreich, Frankreich, Deutschland, Japan, , Vereinigte Staaten, Campaign finance, Party finance, Corruption, Austria, France, Germany, United States

Next-to-Leading Order QCD Corrections to Inclusive Heavy-Flavor Production in Polarized Deep-Inelastic Scattering

We report on a recently completed, first calculation of the full next-to-leading order QCD corrections for heavy flavor contributions to the inclusive structure function $g_1$ in longitudinally polarized deep-inelastic scattering. All results are derived with largely analytical methods and retain the full dependence on the heavy quark's mass. As a first phenomenological application, inclusive charm production at a future electron-ion collider and its sensitivity to the polarized gluon distribution is studied. Theoretical uncertainties due to the residual dependence on unphysical factorization and renormalization scales are estimated.Comment: 6 pages, 6 eps figures, XXVI International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2018