39 research outputs found

    External Subsidies and Lasting Peace

    Get PDF
    Third parties are thought to face a trade-off in that those actions most likely to bring peace in the short run appear least likely to ensure its long-run stability. Yet the trade-off between conflict management and conflict resolution may be overstated. Analyzing an iterated three-player bargaining model with both information and commitment problems, we first demonstrate two conditions under which third parties may produce lasting peace through conditional subsidies, even without addressing underlying informational or commitment problems. Second, we illustrate this possibility by analyzing the impact of US foreign aid on patterns of conflict and peace between Israel and her neighbors. Our analysis indicates that the termination of the rivalry between Israel and Egypt was most likely not brought about by the Camp David accords or peacekeeping operations, but by sustained foreign aid provision. We discuss the implications for both this conflict and conflict management more broadly. </jats:p

    New insights into perinatal testicular torsion

    Get PDF
    Perinatal testicular torsion is a relatively rare event that remains unrecognized in many patients or is suspected and treated accordingly only after an avoidable loss of time. The authors report their own experience with several patients, some of them quite atypical but instructive. Missed bilateral torsion is an issue, as are partial torsion, possible antenatal signs, and late presentation. These data are discussed together with the existing literature and may help shed new light on the natural course of testicular torsion and its treatment. The most important conclusion is that a much higher index of suspicion based on clinical findings is needed for timely detection of perinatal torsion. It is the authors’ opinion that immediate surgery is mandatory not only in suspected bilateral torsions but also in cases of possible unilateral torsions. There is no place for a more fatalistic “wait-and-see” approach. Whenever possible, even necrotic testes should not be removed during surgery because some endocrine function may be retained

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

    Get PDF
    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    4_Phylo_contrasts

    No full text
    R script to perform phylogenetic regression and calculate statistics of phylogenetic signa

    Data from: Benefit of transferred mutations is better predicted by the fitness of recipients than by their ecological or genetic relatedness

    No full text
    The effect of a mutation depends on its interaction with the genetic background in which it is assessed. Studies in experimental systems have demonstrated that such interactions are common among beneficial mutations and often follow a pattern consistent with declining evolvability of more fit genotypes. However, these studies generally examine the consequences of interactions between a small number of focal mutations. It is not clear, therefore, that findings can be extrapolated to natural populations, where new mutations may be transferred between genetically divergent backgrounds. We build on work that examined interactions between four beneficial mutations selected in a laboratory-evolved population of Escherichia coli to test how they interact with the genomes of diverse natural isolates of the same species. We find that the fitness effect of transferred mutations depends weakly on the genetic and ecological similarity of recipient strains relative to the donor strain in which the mutations were selected. By contrast, mutation effects were strongly inversely correlated to the initial fitness of the recipient strain. That is, there was a pattern of diminishing returns whereby fit strains benefited proportionally less from an added mutation. Our results strengthen the view that the fitness of a strain can be a major determinant of its ability to adapt. They also support a role for barriers of transmission, rather than differential selection of transferred DNA, as an explanation of observed phylogenetically determined patterns of restricted recombination among E. coli strains

    ATRX loss is an independent predictor of poor survival in pancreatic neuroendocrine tumours.

    Get PDF
    Pancreatic neuroendocrine tumours (PanNETs) are rare neoplasms accounting for 1-2% of all pancreatic tumours. The biological behaviour of PanNETs is heterogeneous and unpredictable, adding to the difficulties of clinical management. The DAXX (death domain associated protein) and ATRX (alpha-thalassemia/mental retardation syndrome X-linked) genes encode proteins involved in SWI/SNF-like chromatin remodelling. Somatic inactivating mutations in DAXX and ATRX are frequent in PanNETs, mutually exclusive, and associated with telomere dysfunction resulting in genomic instability and alternate lengthening of telomeres. We sought to assess the clinical significance of the loss of the ATRX and DAXX proteins as determined by immunohistochemistry (IHC) in patients with PanNET. From an unselected cohort of 105 patients, we found ATRX loss in 10 tumours (9.5%) and DAXX loss in 16 (15.2%). DAXX and ATRX loss were confirmed mutually exclusive and associated with other adverse clinicopathological variables and poor survival in univariate analysis. In addition ATRX loss was also associated with higher AJCC stage and infiltrative tumour borders. However only ATRX loss, lymphovascular invasion and perineural spread were independent predictors of poor overall survival in multivariate analysis. In conclusion, loss of expression of ATRX as determined by IHC is a useful independent predictor of poor overall survival in PanNETs. Given its relative availability, ATRX loss as determined by IHC may have a role in routine clinical practice to refine prognostication in patients with PanNET

    2_mutation_effect_ANOVA

    No full text
    R Script to perform ANOVA to: (i) examine variation in effect of each mutations over strains, (ii) examine variation in average effect of mutations per strain, and (iii) determine average effect of each mutatio
    corecore