Multistrain Models of Recombinant Transmissible Vaccines with Mutational Decay

In the absence of gene flow, populations undergo local adaptation to their environment. Swamping occurs when migrant genes prevent local adaptation with high levels of gene flow. Although swamping is often depicted as a problem, it could be implemented to arrest unwanted evolution in GMOs which depend on the integrity of transgenes. In GMO vaccines, the fitness cost of carrying an antigen results in reversion to virulence or antigenic decay through a series of mutational steps. Zoonotic diseases pose an increasing threat to people, causing an estimated 2.7 million worldwide human deaths each year. Recombinant transmissible vaccines (RTVs) provide a way to reduce the risk of infectious diseases, especially zoonotic diseases with wildlife reservoirs that cannot be directly vaccinated. A well-documented two-strain SIR model, including pathogen and RTV, represents the situation where an RTV can mutate to its vector in one step. We built an n-strain model expanding upon this model by imagining a similar situation where the RTV must undergo n-1 mutations, rather than one, to revert to the vector. Although the vector is benign, it competes with the RTV for susceptible individuals, thereby reducing the benefits of the RTV. We found that the level of direct vaccination necessary depends on mutation rate and the decline in efficacy from each mutational step. This model allows us to quantify the amount of swamping in order to protect populations against infectious disease and prevent local adaptation

Nuclear weapons, the United States and alliances in Europe and Asia: Toward an institutional perspective

America’s alliances in Europe and East Asia all involve some institutional cooperation on U.S. nuclear weapons policy, planning or employment—from consultative fora in Asia to joint policy and sharing of nuclear warheads in NATO. Such cooperation is often analyzed through the prism of “extended nuclear deterrence,” which focuses on the extension of U.S. security guarantees and their effect on potential adversaries. This article argues that this underplays the importance of institutional factors: Allies have historically addressed a range of objectives through such cooperation, which has helped to catalyze agreements about broader alliance strategy. The varied form such cooperation takes in different alliances also flows from the respective bargaining power of allies and the relative importance of consensus, rather than perceived threats. The article concludes that nuclear weapons cooperation will remain crucial in successful U.S. alliance management, as allies negotiate their relationship with each other in the face of geostrategic change.No Full Tex

Credit Where It's Due? Valence Politics, Attributions of Responsibility, and Multi-Level Elections

When considering elections in multi-level contexts, scholars have typically assumed-in line with second-order election theory-that the way voters approach an election depends on their attributions of responsibility, that is, on what they see as being at stake in that election. This assumption is questionable. The formal position is not always clear, and is further blurred by parties and the media. Moreover, many voters pay little attention to politics and have little incentive to trace constitutional responsibilities. In this paper I use data from election studies in two multi-level contexts, Ontario and Scotland, to explore the nature and impact of voters' attributions of responsibility. The evidence suggests that, when called upon in surveys to do so, many voters can confidently and fairly accurately assign issues to different levels of government. Yet they do not seem to consider these attributions much at elections. There is very little indication that issues weighed heavier in the decision-making of those who regarded them as the responsibility of that electoral arena. A plausible explanation is that most voters sidestep the cognitive demands imposed by multi-level elections