Specification Issues in Proximity Models of Candidate Evaluation (with Issue Importance)

Bryce E. Corrigan Department of Political Science, University of Michigan, 5700 Haven Hall, 505 S. State Street, Ann Arbor, MI 48109-1045 e-mail: becorrig{at}umich.edu e-mail: grynaviski{at}uchicago.edu (corresponding author) The use of the proximity model to represent the relationshipbetween citizens' policy attitudes and the positions of candidateson the issues of the day has considerable appeal because itoffers a bridge between theoretical models of political behaviorand empirical work. However, there is little consensus amongapplied researchers about the appropriate representation ofvoter behavior with respect to the measurement of issue distance,candidate location, or whether to allow heterogeneity in theweight that each individual places on particular issues. Eachof these choices suggests a different, and reasonably complicated,nonlinear relationship between voter utility and candidate andvoter issue positions which may have a meaningful influenceon the substantive conclusions drawn by the researcher. Yet,little attention has been given to the best way to representthe proximity model in applied work. The purpose of this paperis to identify which forms of the proximity model work best,with particular consideration given to the identification offunctional forms that are invariant to the choice of scale forthe independent variables.     

Identification of N,N-dimethylamphetamine formed by methylation of methamphetamine in formalin-fixed liver tissue by multistage mass spectrometry

Methamphetamine is methylated in the presence of unbuffered formalin solutions within hours at room temperature. The product, N,N-dimethylamphetamine, is also found in human liver exposed to methamphetamine followed by incubation with formalin. In the present study, a direct mass spectrometric method was developed to identify N,N-dimethylamphetamine in human liver before and after treatment with formalin. Human liver samples were obtained from four deaths that were investigated by the West Virginia Office of Chief Medical Examiner. Full toxicological analysis was conducted on samples from the decedents and methamphetamine was among the positive findings in each case. The method used to expose liver tissue to formaldehyde involved treating a small piece of liver from each case with formalin solution (20% v/v) for 24 h at room temperature. The formalin treated tissues were homogenized and the resulting suspension was sonicated for 5 min, and then centrifuged. Supernatant aliquots were directly analyzed by electrospray ionization (ESI) mass spectrometry without chromatographic isolation. Positive ion multistage mass spectra recorded in MS, MS/MS and MS/MS/MS (MS3) modes were used to confirm the presence of N,N-dimethylamphetamine and methamphetamine in the mixture. Liver tissue not treated with formalin did not contain a detectable level of N,N-dimethylamphetamine. Decreases in methamphetamine concentrations in liver tissue resulting from treatment with formalin were measured using deuterium-labeled methamphetamine as internal standard. The method can be completed in less than 2 h on thawed tissue. The results suggest that the process of fixing tissues with formalin may lead to false negative findings for methamphetamine.     

Violence in the city: Empirical bases for a collective working image

Many police patrol officers in Newark, New Jersey, articulate a working image of violence in the city that is similar to Louis Wirth's classical model of the effects of urban social disorganization on deviant behavior. In Newark, however, the working theory posits the 1967 civil disorders as a cataclysmic disorganizing event that generated ominously unique patterns of violence in the post-disorder years, compared to earlier times. Using data on violent crimes reported to the Newark police between 1940 and 1980, this article attempts to test the adequacy of that working theory as an explanation of reality. Regression techniques similar to those used by Friesma (1979) to assess natural disaster impacts are applied to three transformations of these crime data. The analysis demonstrates that the police working version of the disorganization model is more accurate as an inference from the pattern of violence that characterizes their workload than it is one from the patterns of absolute incidence of violent crime or of the risk of violent victimization incurred by residents of Newark. The article closes with a discussion of the implications of these findings for the larger problem of police-citizen distance.