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Surrogate selection is an experimental design that without sequencing any DNA can restrict a sample of cells to those carrying certain genomic mutations. In immunological disease studies, this design may provide a relatively easy approach to enrich a lymphocyte sample with cells relevant to the disease response because the emergence of neutral mutations associates with the proliferation history of clonal subpopulations. A statistical analysis of clonotype sizes provides a structured, quantitative perspective on this useful property of surrogate selection. Our model specification couples within-clonotype birth-death processes with an exchangeable model across clonotypes. Beyond enrichment questions about the surrogate selection design, our framework enables a study of sampling properties of elementary sample diversity statistics; it also points to new statistics that may usefully measure the burden of somatic genomic alterations associated with clonal expansion. We examine statistical properties of immunological samples governed by the coupled model specification, and we illustrate calculations in surrogate selection studies of melanoma and in single-cell genomic studies of T cell repertoires. 

The siderophile elements, which include Re, Pt, Os, and W, directly constrain the accretionary history of Earth. The largely chondritic 186,187Os/188Os ratios of Earth’s mantle, coupled with excesses in siderophile element abundances, provide nearly incontrovertible evidence that some meteoritic addition continued after core formation was complete. Osmium and W isotope systematics of plume-derived mafic-ultramafic rocks reveal the complex chemical evolution of their deep mantle sources. In the upper mantle, Re-Os dating of whole-rock xenoliths and sulfide inclusions in diamonds hosted by kimberlites indicate both ancient melt depletion and subsequent modification of the mantle lithosphere beneath the earliest continents, with Re-Os ages of eclogitic diamonds possibly recording the transition to a sustained plate tectonic regime on Earth. 

Paternity leave may promote greater gender equality in domestic labour. Though numerous studies show that paternity leave promotes greater fathers’ involvement in childcare, less is known about whether paternity leave-taking may facilitate fathers’ involvement in other forms of domestic labour such as housework. Using repeated cross-sectional data on different-gender partnered US parents from the Study on Parents’ Divisions of Labor During COVID-19 (SPDLC), this study examines the extent to which paternity leave-taking and length of paternity leave are associated with US fathers’ shares of, and time spent on, housework. Findings suggest that paternity leave-taking is positively associated with fathers’ shares of, and time spent on, housework tasks. Longer paternity leaves are also associated with fathers performing greater shares of housework. Overall, this study indicates that the benefits of paternity leave likely extend to fathers’ greater participation in housework, providing additional support for the belief that increased use of paternity leave may help to promote gender equality in domestic labour. 

Remote and hybrid work have received much attention since the expansion of off-site work following the COVID-19 pandemic. Research on the effects of these arrangements on workers’ well-being, however, is mixed, likely because studies rarely account for workers’ workplace preferences. Using data from the 2023 wave of the Study on U.S. Parents’ Divisions of Labor During COVID-19 (SPDLC), we assess the association between work-place mismatch (misalignment between preferred and actual work locations) and both work-family conflict and psychological well-being (stress and depressive symptoms) among partnered working parents. Results suggest that most parents report some degree of work-place mismatch, with on-site workers reporting the highest work-place mismatch. We also find that work-place mismatch is positively associated with work-family conflict and negatively associated with parents’ psychological well-being. After accounting for work-place mismatch, parents who work on-site report lower work-family conflict and higher psychological well-being than remote and hybrid workers. Overall, results highlight the need to account for workers’ preferences in understanding the association between work conditions, work-family conflict, and psychological well-being.