Evaluation of a multicapillary electrophoresis instrument for mitochondrial DNA typing

Laser-induced detection of fluorescent labeled PCR products and multi-wavelength detection (i.e., multicolor analysis) enables rapid generation of mtDNA sequencing profiles. Traditionally, polyacrylamide slab gels have been used as the electrophoretic medium for mtDNA sequencing in forensic analyses. Replacement of slab gel electrophoresis with capillary electrophoresis (CE) can facilitate automation of the analytical process. Automation and high throughput can be further enhanced by using multicapillary electrophoretic systems. The use of the ABI Prism 3100 Genetic Analyzer (ABI 3100, Applied Biosystems, Foster City, CA) as well as the ABI Prism 310 Genetic Analyzer (ABI 310, Applied Biosystems, Foster City, CA) were evaluated for mtDNA sequencing capabilities and compared with sequencing results obtained on the platform currently in use in the FBI Laboratory (the ABI Prism 377 DNA Sequencer, ABI 377, Applied Biosystems, Foster City, CA). Various studies were performed to assess the utility of the ABI 3100, as well as the ABI 310 for mtDNA sequencing. The tests included: comparisons of results obtained among the ABI 3100, the ABI 310 and the ABI 377 instruments; comparisons of results obtained within and between capillary arrays; evaluation of capillary length; evaluation of sample injection time; evaluation of the resolution of mixtures/heteroplasmic samples; and evaluation of the sensitivity of detection of a minor component with reduced template on the ABI 3100. In addition, other studies were performed to improve sample preparation; these included: comparison of template suppression reagent (TSR, Applied Biosystems, Foster City, CA) versus formamide; the use of Performa DTR Gel Filtration Cartridges (Edge BioSystems Inc., Gaithersburg, MD) versus Centri-Sep Spin Columns (Princeton Separations, Adelphia, NJ) for product purification after cycle sequencing; and sample stability after denaturation. The data support that valid and reliable results can be obtained using either capillary electrophoresis instrument, and the quality of sequencing results are comparable to or better than those obtained from the ABI 377 instrument.     

Contamination of brake fluid by power steering fluid

Analysis of a contaminated brake fluid revealed the contaminant to be power steering fluid. The sample received at the laboratory presented two immiscible phases, which were both organic. Both fluids were analyzed by GC-MS and compared with a library of known automotive fluids. The bottom layer (brake fluid) consisted of glycols while the top layer (power steering fluid) consisted of aliphatics ranging from C16 to C25+. An interesting phenomenon of diffusion of some of the glycols from the brake fluid phase into the power steering fluid phase was observed and needs to be taken into consideration in the interpretation of the results.     

Using resolution calculations to assess changes in capillary electrophoresis run parameters

Capillary electrophoresis is widely used in the forensic community for the analysis of Short Tandem Repeat DNA. The CE system used in most forensic laboratories allows the user to modify standard operational protocols to accommodate some samples that fall outside of interpretational guidelines. We have made operational changes and monitored system resolution and the ability of the software to identify alleles as a result of these modifications. Increased amount of amplified product in the injection preparation, lengthened injection times or repeated injections of the same sample were all investigated along with variations in run voltages. Certain protocol modifications offer some advantages to the analysis of STRs and may allow the analyst to avoid extraction of additional portions of crime scene samples to achieve interpretable results.     

Ideas, Inheritances, and the Dynamics of Budgetary Change

Long the lifeblood of public administration, budgeting in the United States acquired a new importance during the 1980s and 1990s because of the fiscalization of the policy debate. But how much has American national budgeting really changed? This article examines the evolution of federal budgeting over the past half-century, exploring such developments as the massive growth of entitlements, congressional budget reform, and the protracted battle over the budget deficit. It finds that year-to-year changes in budget results have been relatively small even while budgetary rules and procedures have experienced sweeping change. At the same time, the composition of federal spending has undergone a quiet revolution. The traditional concept of budgetary incrementalism offers an incomplete explanation for these dynamics. To make sense of them, the article focuses on two key factors: the impact of policy inheritances, and the role of actors' causal and normative beliefs. These factors shape the ideational and material context within which boundedly rational actors negotiate decisions. The tension between changes in ideas and entrenched budgetary commitments has often served to stimulate institutional reform.     

Assessing Violence Risk Among Discharged Psychiatric Patients: Toward an Ecological Approach

This paper draws upon data from the Pittsburgh site of the MacArthur Foundation's Risk Assessment Study, a large-scale study of violence risk among persons discharged from psychiatric hospitals, to examine the effect of the neighborhood context on risk of violence. This paper has two purposes: (1) to assess the extent to which the inclusion of neighborhood characteristics enhances violence prediction models—models that traditionally only include individual-level characteristics; and (2) to assess the consistency of individual level risk factors across different neighborhood contexts. Results indicate that neighborhood poverty has an impact over and above the effects of individual characteristics in identifying cases with violence. These findings support efforts to include neighborhood context in the assessment and management of violence risk among discharged psychiatric patients.     

Choosing among signalling equilibria in lobbying games: A reply to Sloof

Randolph Sloof has written a comment on the lobbying-as-signalling model in Rasmusen (1993) in which he points out an equilibrium I missed and criticizes my emphasis on a particular separating equilibrium (see this issue). In this response, I discuss how to interpret multiple equilibria in games and how to interpret mixed strategy equilibria in which two types of player with identical incentives must pick different mixing probabilities.     

A Longitudinal Study of the Interactive Effects of Impulsivity and Anger on Adolescent Problem Behavior

The current study examined the moderating effect of impulsivity on the relation between anger and adolescent problem behavior (substance use and delinquency). High levels of anger were associated with delinquency for impulsive, but not for nonimpulsive adolescents in cross-sectional analyses. This moderating effect was not supported for substance use. Gender-moderated links between temperament and problem behavior showed that anger predicted substance use for females only, and impulsivity was more strongly associated with delinquency for males. In prospective analyses, both anger and impulsivity predicted adolescent problem behavior, but impulsivity did not moderate the effects of anger. Overall, results provided partial support for the notion that temperament dimensions operate interactively to promote poor adjustment.     

The relationship between congressional spending and tenure with an application to term limits

Whether term limits would increase or decrease federal spending depends on the reason for the causal relationship between tenure and spending. We investigate this subject by empirically studying congressional spending and tenure for all United States House and Senate members who entered Congress between the 94th and 102nd Congresses (1975–1992). As our measure of congressional spending we use the National Taxpayers Union's Congressional Spending Scores. Our study finds that a statistically significant relationship exists between congressional spending and tenure for some groups of congressmen. We then test three hypotheses relating tenure and spending. No single hypothesis is consistent with all of our empirical results. Nevertheless, the small sizes of the empirical effects estimated in this study suggest that term limits would have an inconsequential impact on the level of federal spending – at least via the “moral hazard” mechanisms described in this paper.