Genetic Diversity of Invasive Species in the Great Lakes Versus Their Eurasian Source Populations: Insights for Risk Analysis

Combining DNA variation data and risk assessment procedures offers important diagnostic and monitoring tools for evaluating the relative success of exotic species invasions. Risk assessment may allow us to understand how the numbers of founding individuals, genetic variants, population sources, and introduction events affect successful establishment and spread. This is particularly important in habitats that are "hotbeds" for invasive species--such as the North American Great Lakes. This study compares genetic variability and its application to risk assessment within and among three Eurasian groups and five species that successfully invaded the Great Lakes during the mid 1980s through early 1990s; including zebra and quagga mussels, round and tubenose gobies, and the ruffe. DNA sequences are compared from exotic and native populations in order to evaluate the role of genetic diversity in invasions. Close relatives are also examined, since they often invade in concert and several are saline tolerant and are likely to spread to North American estuaries. Results show that very high genetic diversity characterizes the invasions of all five species, indicating that they were founded by very large numbers of propagules and underwent no founder effects. Genetic evidence points to multiple invasion sources for both dreissenid and goby species, which appears related to especially rapid spread and widespread colonization success in a variety of habitats. In contrast, results show that the ruffe population in the Great Lakes originated from a single founding population source from the Elbe River drainage. Both the Great Lakes and the Elbe River populations of ruffe have similar genetic diversity levels--showing no founder effect, as in the other invasive species. In conclusion, high genetic variability, large numbers of founders, and multiple founding sources likely significantly contribute to the risk of an exotic species introduction's success and persistence.     

Getting the Fundamentals Right: Autonomization as a Reform and Governance Tool in the Case of the State Insurance Company Ltd. (SIC) in Ghana

The article is primarily a case study of the use of autonomization in the reform and restructuring of the State Insurance Company Ltd, an SOE in Ghana and addresses two main questions. (1) In view of the fact that the SIC has dual commercial and political objectives, is autonomization suitable for its reform? (2) Under what circumstances can autonomization actually promote efficiency and effectiveness in the proper management and functioning of the SIC? The findings point to answers for both questions. First, autonomization is a defective tool for reforming politically sensitive SOEs but better for non-politically sensitive ones. Secondly, the results point to genuine concerns that autonomization weakens the bonds of political accountability and increases fragmentation of government programs. Finally, the key words in the adoption and implementation of autonomization ought to be context, agency task-specificity and creative adaptation. It adds to the management literature on sub-Saharan Africa and to understanding the management context of Ghana.     

Specification tests for time-varying parameter models with stochastic volatility

We propose an easy technique to test for time-variation in coefficients and volatilities. Specifically, by using a noncentered parameterization for state space models, we develop a method to directly calculate the relevant Bayes factor using the Savage–Dickey density ratio—thus avoiding the computation of the marginal likelihood altogether. The proposed methodology is illustrated via two empirical applications. In the first application, we test for time-variation in the volatility of inflation in the G7 countries. The second application investigates if there is substantial time-variation in the nonaccelerating inflation rate of unemployment (NAIRU) in the United States.     

Bidirectional Relations between Adverse Childhood Experiences and Children’s Behavioral Problems

Child and Adolescent Social Work Journal - Research has shown that adverse childhood experiences (ACEs) increase the risk of poor health and well-being, yet less is known about the pathways through...     

Adult resilience among maltreated children: A prospective investigation of main effect and mediating models

Studies examining resilience to child maltreatment reveal that maltreatment victims can achieve adaptive functioning in several areas of development; however, few of these individuals persistently demonstrate resilience across multiple domains. The majority of these investigations define adjustment with a limited number of outcomes measured proximal in time to the maltreatment experience. In contrast, this study measured adjustment across a diverse set of domains during early adulthood (ages 16–24), a number of years after the occurrence of childhood maltreatment (ages 0–11).     

Social status, values, and support for reform in education

Using a survey of Ohio and Indiana residents, we analyze the extent to which public support for school vouchers and school finance reform is structured by the same socioeconomic interests and values (equality, humanitarianism, individualism, and limited government) as is public support for contentious welfare policies. Disadvantaged individuals and individuals who live in disadvantaged communities are more likely to support vouchers but social status has a more ambiguous influence on support for finance reform. Values cannot explain the effect of social status on support for these education policies, but they exert independent effects. We speculate that disadvantaged individuals are more likely to see vouchers as in their interests than are advantaged individuals because voucher advocates have allied themselves with social movements and organizations representing clear constituencies (religious conservatives, low-income urban parents). On the other hand, we suggest that finance reform is more of an abstract issue because its advocates have mostly concentrated on intragovernmental litigation, and thus cleavages based on social status tend to be more obscured.     

A method for modifying multiple testing procedures

Many recent multiple testing papers have provided more efficient and/or robust methodology for control of a particular error rate. However, different multiple testing scenarios call for the control of different error rates. Hence, the procedure possessing the desired optimality and/or robustness properties may not be applicable to the problem at hand. This paper provides a general method for extending any multiple testing procedure to control any error rate, thereby allowing for the procedure possessing the desired properties to be used to control the most relevant error rate. As an example, two popular procedures that were originally designed to control the marginal and positive False Discovery Rate are extended to control the False Discovery Rate and Family-wise Error Rate. It is shown that optimality and/or robustness properties of the original procedure are retained when it is modified using the proposed method.