When white people experience the weight of the past:The role of white identity strategies in linking colonialism to current racial inequalities

How do White Europeans address racial inequalities in times of burgeoningdiscussions about colonialism? The current research explores the strategies that White people in the Netherlands use to manage their racial-ethnic identity in relation to linking colonialism and current racial inequalities. With this, we examined how White identity strategies were related to ideologies legitimizing racial inequalities. Using mixed-methods consisting of qualitative interviews (N = 24) and quantitative surveys (N = 564), we found that White people exhibited different combinations of prideful (“I am a proud person of our ethnic heritage”), dissociated (“My ethnic group does not have a significant impact on how I see the world”), and power-cognizant (“I am a White person with privileges because of my ethnic group”) identity strategies. Moreover, these White identity strategies were associated withlinking colonialism and racial inequalities and, thereby, with ideologies legitimizing them. Specifically, White people holding prideful and dissociated strategies were less likely to link colonialism and racial inequalities than White people who exclusively endorsed powercognizance. Furthermore, power-cognizant people challenged current-day racial inequalities the most. We conclude by discussing how White European people legitimize or question racial inequalities by managing their whiteness and the theoretical and practical implications of these findings

Quinolone signaling in the cell-to-cell communication system of Pseudomonas aeruginosa

Numerous species of bacteria use an elegant regulatory mechanism known as quorum sensing to control the expression of specific genes in a cell-density dependent manner. In Gram-negative bacteria, quorum sensing systems function through a cell-to-cell signal molecule (autoinducer) that consists of a homoserine lactone with a fatty acid side chain. Such is the case in the opportunistic human pathogen Pseudomonas aeruginosa, which contains two quorum sensing systems (las and rhl) that operate via the autoinducers, N-(3-oxododecanoyl)-L-homoserine lactone and N-butyryl-Lhomoserine lactone. The study of these signal molecules has shown that they bind to and activate transcriptional activator proteins that specifically induce numerous P. aeruginosa virulence genes. We report here that P. aeruginosa produces another signal molecule, 2-heptyl-3-hydroxy-4-quinolone, which has been designated as the Pseudomonas quinolone signal. It was found that this unique cell-to-cell signal controlled the expression of lasB, which encodes for the major virulence factor, LasB elastase. We also show that the synthesis and bioactivity of Pseudomonas quinolone signal were mediated by the P. aeruginosa las and rhl quorum sensing systems, respectively. The demonstration that 2-heptyl-3- hydroxy-4-quinolone can function as an intercellular signal sheds light on the role of secondary metabolites and shows that P. aeruginosa cell-to-cell signaling is not restricted to acyl-homoserine lactones. Originally published Proc. Natl. Acad. Sci, Vol. 96, No. 20, Sep. 199

Crustal Composition and Moho Variations of the Central and Eastern United States: Improving Resolutionand Geologic Interpretation of EarthScope USArray Seismic Images Using Gravity

EarthScope\u27s USArray Transportable Array has shortcomings for the purpose of interpreting geologic features of wavelengths less than the Transportable Array station spacing, but these can be overcome by using higher spatial resolution gravity data. In this study, we exploit USArray receiver functions to reduce nonuniqueness in the interpretation of gravity anomalies. We model gravity anomalies from previously derived density variations of sedimentary basins, crustal Vp/Vs variation, Moho variation, and upper mantle density variation derived from body wave imaging informed by surface wave tomography to estimate Vp/Vs. Although average densities and density contrasts for these seismic variations can be derived, the gravity anomalies modeled from them do not explain the entire observed gravity anomaly field in the United States. We use the unmodeled gravity anomalies (residuals) to reconstruct local variations in densities of the crust associated with geologic sources. The approach uses velocity‐density relationships and differs from density computations that assume isostatic compensation. These intracrustal densities identify geologic sources not sampled by and, in some cases, aliased by the USArray station spacing. We show an example of this improvement in the vicinity of the Bloomfield Pluton, north of the bootheel of Missouri, in the central United States