Identification of Chromosomal Genes in Yersinia pestis that Influence Type III Secretion and Delivery of Yops into Target Cells

Pathogenic Yersinia species possess a type III secretion system, which is required for the delivery of effector Yop proteins into target cells during infection. Genes encoding the type III secretion machinery, its substrates, and several regulatory proteins all reside on a 70-Kb virulence plasmid. Genes encoded in the chromosome of yersiniae are thought to play important roles in bacterial perception of host environments and in the coordinated activation of the type III secretion pathway. Here, we investigate the contribution of chromosomal genes to the complex regulatory process controlling type III secretion in Yersinia pestis. Using transposon mutagenesis, we identified five chromosomal genes required for expression or secretion of Yops in laboratory media. Four out of the five chromosomal mutants were defective to various extents at injecting Yops into tissue culture cells. Interestingly, we found one mutant that was not able to secrete in vitro but was fully competent for injecting Yops into host cells, suggesting independent mechanisms for activation of the secretion apparatus. When tested in a mouse model of plague disease, three mutants were avirulent, whereas two strains were severely attenuated. Together these results demonstrate the importance of Y. pestis chromosomal genes in the proper function of type III secretion and in the pathogenesis of plague

Menstruation in art and visual culture

Menstruation has a rich and growing body of academic literature, including on the use of language, the history of medicine, and cultural understandings. Since the 1970s, scholars have analyzed the visual impact of the marketing and branding of menstrual products, and its effects on menstrual shame. Artists have offered a different visual perspective, often utilizing menstrual blood directly. Recent scholarship about menstrual art has added to our understanding of shame about menstruation. In this entry we present and examine the key studies about menstruation in advertising, art, and other visual media, and situate this in a cultural, historical, and art historical context

Why Individuals Protest the Perceived Transgressions of Their Country: The Role of Anger, Shame, and Guilt

The present research examined emotions as predictors of opposition to policies and actions of one's country that are perceived to be illegitimate. Two studies investigated the political implications of American (Study 1) and British (Study 2) citizens' anger, guilt, and shame responses to perceived harm caused by their countries' occupation of Iraq. In both studies, a manipulation of pervasive threat to the country's image increased participants' shame but not guilt. The emotions predicted political action intentions to advocate distinct opposition strategies. Shame predicted action intentions to advocate withdrawal from Iraq. Anger predicted action intentions to advocate compensation to Iraq, confrontation of agents responsible, and withdrawal from Iraq. Anger directed at different targets (ingroup, ingroup representative, and outgroup representative) predicted action intentions to support distinct strategies (Study 2). Guilt did not independently predict any political action intentions. Implications for the study of political action and emotions in intergroup contexts are discussed