Federalism and Consociational Regimes

Federalism and consociationalism are useful means of understandingpolitical systems. Federalism and consociationalism are bothbased on compound majoritarianism rather than simple majoritarianism,and both represent modern attempts to accommodate democraticcomplexity and pluralism, but the two systems are not quitesymmetrical, and territorial organization is not the only characteristicthat differentiates them. Instead, it can be said that federalismrelates to the form of a polity, while consociationalism relatesto the character of a regime. To the extent that federalismmay also function as the character of a regime, then federalismand consociationalism may be more symmetrical. One of the ambiguitiesof federalism is that it is often both form and regime. Consociationalism,however, relates only to regime.     

Exploring Some Analytical Characteristics of Finite Mixture Models

Finite mixture models have become increasingly prevalent in criminology over the past two decades. Yet there is no consensus about the appropriate criterion for model selection with finite mixture specifications. In this paper, we use simulation evidence to examine model selection criteria. Our focus is on mixture models for event count data like those often encountered in criminology. We use two indices to measure model selection performance. First, we examine how often each criterion chooses the correct specification. Then, we investigate how closely the finite mixture models selected by these criteria approximate the true mixing distribution used to simulate the event count data. We consider three sets of simulations. In the first set, the underlying model is itself a three component Poisson-based finite mixture model. In the two other sets of simulations, the underlying distribution of the Poisson rate parameter follows a continuous distribution. The analysis shows that both AIC and BIC perform well under certain sets of circumstances likely to be encountered by criminologists.

The relationship between trauma and violence in a jail inmate sample

Research suggests there is a link between trauma and violence, although the nature of the relationship is rather equivocal. This study explored this relationship by examining self-reported trauma as a predictor of self-reported violence in 93 jail inmates. Ninety-six percent of the sample reported experiencing a traumatic event, and 67% reported having been violent during the year preceding incarceration. Inmates reporting trauma were more than twice as likely to report having been violent than nonviolent. Stepwise multiple regression analyses suggested traumatic events, as a combined model, significantly contributed to violence perpetration. In addition, witnessing serious violence predicted perpetration of violence. Implications and limitations of the present study are discussed.     

Microchip-based cell lysis and DNA extraction from sperm cells for application to forensic analysis

The current backlog of casework is among the most significant challenges facing crime laboratories at this time. While the development of next-generation microchip-based technology for expedited forensic casework analysis offers one solution to this problem, this will require the adaptation of manual, large-volume, benchtop chemistry to small volume microfluidic devices. Analysis of evidentiary materials from rape kits where semen or sperm cells are commonly found represents a unique set of challenges for on-chip cell lysis and DNA extraction that must be addressed for successful application. The work presented here details the development of a microdevice capable of DNA extraction directly from sperm cells for application to the analysis of sexual assault evidence. A variety of chemical lysing agents are assessed for inclusion in the extraction protocol and a method for DNA purification from sperm cells is described. Suitability of the extracted DNA for short tandem repeat (STR) analysis is assessed and genetic profiles shown. Finally, on-chip cell lysis methods are evaluated, with results from fluorescence visualization of cell rupture and DNA extraction from an integrated cell lysis and purification with subsequent STR amplification presented. A method for on-chip cell lysis and DNA purification is described, with considerations toward inclusion in an integrated microdevice capable of both differential cell sorting and DNA extraction. The results of this work demonstrate the feasibility of incorporating microchip-based cell lysis and DNA extraction into forensic casework analysis.