STR analysis of artificially degraded DNA-results of a collaborative European exercise

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.     

A Linear Poisson Autoregressive Model: The Poisson AR(p) Model

Time series of event counts are common in political scienceand other social science applications. Presently, there arefew satisfactory methods for identifying the dynamics in suchdata and accounting for the dynamic processes in event countsregression. We address this issue by building on earlier workfor persistent event counts in the Poisson exponentially weightedmoving-average model (PEWMA) of Brandt et al. (American Journalof Political Science 44(4):823–843, 2000). We developan alternative model for stationary mean reverting data, thePoisson autoregressive model of order p, or PAR(p) model. Issuesof identification and model selection are also considered. Wethen evaluate the properties of this model and present bothMonte Carlo evidence and applications to illustrate.     

Rechtliche Handlungsmöglichkeiten zur Offenhaltung der Landschaft – am Beispiel Baden-Württembergs

Zusammenfassung  Viele l?ndliche Regionen sind mit einer Ausdehnung der Waldfl?chen konfrontiert. Dies wird vor allem dann als problematisch empfunden, wenn die betroffenen R?ume bereits waldreich sind. Zur Steuerung der Waldzunahmedynamik bieten sich verschiedene rechtliche Instrumente an, deren Potenziale derzeit nicht voll ausgesch?pft werden. Weiterentwicklungsm?glichkeiten bestehen insbesondere im Hinblick auf die Normen zur Aufforstungsgenehmigung. Hier ist ein grunds?tzlicher normativer Paradigmenwechsel denkbar. Neureglungen k?nnten aber auch über die Einrichtung einer Experimentiergesetzgebung zun?chst beispielhaft erprobt werden. Der Beitrag entwickelt zudem einen Leitfaden für die Beurteilung einer “erheblichen Beeintr?chtigung des Landschaftsbilds”, einem bisher nicht ausreichend konkretisierten Versagungsgrund für eine Aufforstungsgenehmigung.     

Advances in Bayesian Time Series Modeling and the Study of Politics: Theory Testing, Forecasting, and Policy Analysis

John R. Freeman Department of Political Science, University of Minnesota, 267 19th Avenue, Minneapolis, MN 55455 e-mail: pbrandt{at}utdallas.edu (corresponding author) e-mail: freeman{at}polisci.umn.edu Bayesian approaches to the study of politics are increasinglypopular. But Bayesian approaches to modeling multiple time serieshave not been critically evaluated. This is in spite of thepotential value of these models in international relations,political economy, and other fields of our discipline. We reviewrecent developments in Bayesian multi-equation time series modelingin theory testing, forecasting, and policy analysis. Methodsfor constructing Bayesian measures of uncertainty of impulseresponses (Bayesian shape error bands) are explained. A referenceprior for these models that has proven useful in short- andmedium-term forecasting in macroeconomics is described. Oncemodified to incorporate our experience analyzing political dataand our theories, this prior can enhance our ability to forecastover the short and medium terms complex political dynamics likethose exhibited by certain international conflicts. In addition,we explain how contingent Bayesian forecasts can be constructed,contingent Bayesian forecasts that embody policy counterfactuals.The value of these new Bayesian methods is illustrated in areanalysis of the Israeli-Palestinian conflict of the 1980s.     

The Functions of Symbolic Racism

Symbolic racism (SR) has attracted critique and controversy. One controversy that has remained unresolved is the function of SR. SR theorists suggest that SR originates from Black individualism and represents a new form of racism. Others suggest that SR originates in opposition to equality and serves to legitimize these socially inappropriate attitudes. The current paper argues that SR can arise from both Black individualism and anti-equality attitudes, thus serving both as a new expression of racism but also as a legitimizing ideology. A preliminary test of this hybrid model was examined with survey data from a community and university sample. Results suggest that a hybrid model of the underpinnings of SR explains more variance in SR than either the Black individualism or legitimizing ideology models. Furthermore, SR mediated the relationships between both anti-equality attitudes and Black individualism on opposition to affirmative action policy and diversity in work and education settings.     

Why does bureaucratic corruption occur in the EU?

Why does bureaucratic corruption occur in the EU system? Several examples suggest that bureaucratic corruption exists and that the Commission’s anti-fraud agency, OLAF, is not a fully independent authority. We thus develop a novel interpretation of the principal-supervisor-agent model to cope with non-independent anti-fraud units. This model shows that corruption is likely to occur when the expected value to the client from bribing the agent is larger than the expected value to the principal of truth-telling by the supervisor. Overall, this analysis points to the risks of flawed incentives and the lack of institutional independence among principal, agent, supervisor and client. Our main policy recommendations as a result of these findings are that OLAF should be placed outside the Commission, and that whistleblowers should receive adequate protection.