Central events in the interactions of 28Si\bf{^{28}Si} and 32S\bf{^{32}S} with heavy emulsion targets

Data on the multiplicity of secondaries in central events of $\mathsf{^{28}Si}$ (14.6 AGeV) and $\mathsf{^{32}S}$ (3.7 AGeV) interactions with AgBr emulsion nuclei have been compiled and studied. The dependence of the multiplicities of the outgoing charged stripping particles on the number of interacting nucleons and therefore on the impact parameter, as indicated by the target size, and consequently, on the degree of centrality is investigated. The resultant multiplicity distribution of the produced pions for each studied case is fitted by both Negative Binomial (NB) and Poisson distributions. The NB distribution is valid for most of the considered cases. The transparency of the target for a projectile was found to become more pronounced as the incident energy increased

p53 represses class switch recombination to IgG2a through its antioxidant function

Ig class switch recombination (CSR) occurs in activated mature B cells, and causes an exchange of the IgM isotype for IgG, IgE, or IgA isotypes, which increases the effectiveness of the humoral immune response. DNA ds breaks in recombining switch (S) regions, where CSR occurs, are required for recombination. Activation-induced cytidine deaminase initiates DNA ds break formation by deamination of cytosines in S regions. This reaction requires reactive oxygen species (ROS) intermediates, such as hydroxyl radicals. In this study we show that the ROS scavenger N-acetylcysteine inhibits CSR. We also demonstrate that IFN-gamma treatment, which is used to induce IgG2a switching, increases intracellular ROS levels, and activates p53 in switching B cells, and show that p53 inhibits IgG2a class switching through its antioxidant-regulating function. Finally, we show that p53 inhibits DNA breaks and mutations in S regions in B cells undergoing CSR, suggesting that p53 inhibits the activity of activation-induced cytidine deaminase

Towards a decade of synergising corpus linguistics and critical discourse analysis: A meta-analysis

The incorporation of corpus linguistics (CL) methods within critical discourse analysis (CDA) has increasingly gathered momentum over the last decade. This paper surveys studies using this triangulated framework, drawing on a database of 121 studies collected from three citation indexes: Social Sciences Citation Index, Arts and Humanities Citation Index, and Scopus. It presents a meta-analysis of these studies focussing on four variables, namely their chronological development, the domains of engagement, the issues that have been topicalised, and the area/regional coverage of the studies. In particular, the paper accounts for the factors that have contributed to the popularity of corpus-based CDA in the last decade as an approach to discourse analysis, provides insights into the evolution of this eclectic approach, and anticipates the future of the framework by offering suggestions. The paper concludes that corpus-based CDA presents both discourse analysts and corpus linguists with a robust methodology to tackle research questions bordering on discursive reflections of social issues and to identify new sites of public discourse for systematic analysis