Genetic resiliency and the Black Death: No apparent loss of mitogenomic diversity due to the Black Death in medieval London and Denmark

ObjectivesIn the 14th century AD, medieval Europe was severely affected by the Great European Famine as well as repeated bouts of disease, including the Black Death, causing major demographic shifts. This high volatility led to increased mobility and migration due to new labor and economic opportunities, as evidenced by documentary and stable isotope data. This study uses ancient DNA (aDNA) isolated from skeletal remains to examine whether evidence for largeâ scale population movement can be gleaned from the complete mitochondrial genomes of 264 medieval individuals from England (London) and Denmark.Materials and MethodsUsing a novel libraryâ conserving approach to targeted capture, we recovered 264 full mitochondrial genomes from the petrous portion of the temporal bones and teeth and compared genetic diversity across the medieval period within and between English (London) and Danish populations and with contemporary populations through population pairwise ΦST analysis.ResultsWe find no evidence of significant differences in genetic diversity spatially or temporally in our dataset, yet there is a high degree of haplotype diversity in our medieval samples with little exact sequence sharing.DiscussionThe mitochondrial genomes of both medieval Londoners and medieval Danes suggest high mitochondrial diversity before, during and after the Black Death. While our mitochondrial genomic data lack geographically correlated signals, these data could be the result of high, continual female migration before and after the Black Death or may simply indicate a large female effective population size unaffected by the upheaval of the medieval period. Either scenario suggests a genetic resiliency in areas of northwestern medieval Europe.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149364/1/ajpa23820.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149364/2/ajpa23820_am.pd

COVID‐19, nationalism, and the politics of crisis: A scholarly exchange

In this article, several scholars of nationalism discuss the potential for the COVID‐19 pandemic to impact the development of nationalism and world politics. To structure the discussion, the contributors respond to three questions: (1) how should we understand the relationship between nationalism and COVID‐19; (2) will COVID‐19 fuel ethnic and nationalist conflict; and (3) will COVID‐19 reinforce or erode the nation‐state in the long run? The contributors formulated their responses to these questions near to the outset of the pandemic, amid intense uncertainty. This made it acutely difficult, if not impossible, to make predictions. Nevertheless, it was felt that a historically and theoretically informed discussion would shed light on the types of political processes that could be triggered by the COVID‐19 pandemic. In doing so, the aim is to help orient researchers and policy‐makers as they grapple with what has rapidly become the most urgent issue of our times

House ownership and taxes

Abstract: The household portfolio is dominated by a small number of assets; primarily housing and mortgages. We compare data on actual portfolios of Norwegian households with estimated optimal portfolios, using traditional financial theory. We find actual portfolios to be close to the portfolio indicated by a mean-variance frontier, based on four assets and estimated under assumptions of short sale constraints. This result is sustained even in a no-tax regime. To induce a substantial change from housing to equity, taxation of the consumption stream from housing is needed. An alternative; taxation of capital gains from housing investment; could actually increase the relative holding of housing. Keywords: Households, portfolio choice, consumption tax, capital gains tax

House ownership and taxes

Abstract: The household portfolio is dominated by a small number of assets; primarily housing and mortgages. We compare data on actual portfolios of Norwegian households with estimated optimal portfolios, using traditional financial theory. We find actual portfolios to be close to the portfolio indicated by a mean-variance frontier, based on four assets and estimated under assumptions of short sale constraints. This result is sustained even in a no-tax regime. To induce a substantial change from housing to equity, taxation of the consumption stream from housing is needed. An alternative; taxation of capital gains from housing investment; could actually increase the relative holding of housing. Keywords: Households, portfolio choice, consumption tax, capital gains tax

House ownership and taxes

The household portfolio is dominated by a small number of assets; primarily housing and mortgages. We compare data on actual portfolios of Norwegian households with estimated optimal portfolios, using traditional financial theory. We find actual portfolios to be close to the portfolio indicated by a mean-variance frontier, based on four assets and estimated under assumptions of short sale constraints. This result is sustained even in a no-tax regime. To induce a substantial change from housing to equity, taxation of the consumption stream from housing is needed. An alternative; taxation of capital gains from housing investment; could actually increase the relative holding of housing.Households; portfolio choice; consumption tax; capital gains tax.

Insights from genomic comparisons of genetically monomorphic bacterial pathogens

Some of the most deadly bacterial diseases, including leprosy, anthrax and plague, are caused by bacterial lineages with extremely low levels of genetic diversity, the so-called ‘genetically monomorphic bacteria’. It has only become possible to analyse the population genetics of such bacteria since the recent advent of high-throughput comparative genomics. The genomes of genetically monomorphic lineages contain very few polymorphic sites, which often reflect unambiguous clonal genealogies. Some genetically monomorphic lineages have evolved in the last decades, e.g. antibiotic-resistant Staphylococcus aureus, whereas others have evolved over several millennia, e.g. the cause of plague, Yersinia pestis. Based on recent results, it is now possible to reconstruct the sources and the history of pandemic waves of plague by a combined analysis of phylogeographic signals in Y. pestis plus polymorphisms found in ancient DNA. Different from historical accounts based exclusively on human disease, Y. pestis evolved in China, or the vicinity, and has spread globally on multiple occasions. These routes of transmission can be reconstructed from the genealogy, most precisely for the most recent pandemic that was spread from Hong Kong in multiple independent waves in 1894

Validation of reactive gases and aerosols in the MACC global analysis and forecast system

The European MACC (Monitoring Atmospheric Composition and Climate) project is preparing the operational Copernicus Atmosphere Monitoring Service (CAMS), one of the services of the European Copernicus Programme on Earth observation and environmental services. MACC uses data assimilation to combine in situ and remote sensing observations with global and regional models of atmospheric reactive gases, aerosols, and greenhouse gases, and is based on the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts (ECMWF). The global component of the MACC service has a dedicated validation activity to document the quality of the atmospheric composition products. In this paper we discuss the approach to validation that has been developed over the past 3 years. Topics discussed are the validation requirements, the operational aspects, the measurement data sets used, the structure of the validation reports, the models and assimilation systems validated, the procedure to introduce new upgrades, and the scoring methods. One specific target of the MACC system concerns forecasting special events with high-pollution concentrations. Such events receive extra attention in the validation process. Finally, a summary is provided of the results from the validation of the latest set of daily global analysis and forecast products from the MACC system reported in November 2014