Estimating Aggregate Policy Reform Effects: New Baselines for Registration, Participation, and Representation

Statistical models are often extended to explore the aggregateimpact of policy reforms. After discussing these techniquesand the incorporation of prediction uncertainty, this articleexamines the effects of registration reform in an analytic frameworkthat explicitly considers the two stages that defined electoralparticipation throughout the 20th century in the United States—registrationand then voting. Using selection bias techniques, the effectsof counterfactual registration reform conditions are exploredon the aggregate level of participation and the nature of representationin the electoral process. These offer a richer baseline of theimpact of policy changes than previous work by directly exploringthe expected level of dropoff in going to the polls by new registrants.Results indicate that the dropoff between registration and votingwould be expected to increase as more individuals become registered.In addition, while turnout due to reforms among projected "newregistrants" shows potentially larger biases than those amongexisting registrants, because of the different bases of registrationthe changes would still lead to a modest reduction in the disparitybetween actual group sizes and their role in elections.     

Validation of chest X-ray comparisons for unknown decedent identification

Comparing skeletal structures between antemortem and postmortem chest radiographs is widely used by forensic specialists from many disciplines to positively identify unknown decedents. However, validity assessments of this method have been fairly limited. This study had three objectives: 1) to quantify the reliability of ante- and postmortem chest radiograph comparison for decedent identification; 2) to identify useful radiologic features supporting decedent identification; and 3) to recognize sources of error in decedent identification related to use of comparative radiographs. A forensic pathologist, a forensic anthropologist, and two radiologists participated in the study. Our results showed that chest radiograph comparisons proved reliable, if basic decedent information was provided, and antemortem and postmortem radiographs were adequately positioned and exposed. A "morphological approach" using normal anatomical structures for comparison may provide the most efficient method for accurate identification.     

Validation of a 16-locus fluorescent multiplex system

STR multiplexes have been indispensable for the efficient genotyping of forensic samples. The PowerPlex 16 System contains the coreCODIS loci, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D21S11, CSF1PO, FGA, THOI, TPOX, vWA, the sex determinant locus, amelogenin, and two pentanucleotide STR loci, Penta D and Penta E. This multiplex satisfies the locus requirements for most national databases and is the most efficient currently available system due to its single PCR amplification. To provide the groundwork for judicial acceptance, including the publication of primer sequences, and to evaluate laboratory-to-laboratory variation, a developmental validation for casework on this commercially available system was performed in 24 laboratories and produced the following conclusions. Amplification was reliable on a variety of thermal cyclers and product could be analyzed on either an ABI PRISM 310 Genetic Analyzer or an ABI PRISM 377 DNA Sequencer. Genotyping using single source samples was consistent between 0.25 and 2 ng of input DNA template with a few laboratories obtaining complete genotypes at 0.0625 ng. However, heterozygote allele imbalance (<60% peak height balance) caused by stochastic effects was observed at a rate of 13% with 0.125 ng DNA and 22% at 0.0625 ng DNA. Mixture analyses were done using a total of 1 ng of DNA template. Most alleles were detected in mixtures of 4 to 1 and some minor alleles were detected in mixtures of 19 to 1. Optimum amplification cycle number was dependent on the sensitivity of the detection instrument used and could also be adjusted to accommodate larger amounts of DNA on solid supports such as FTA paper. Reaction conditions including volume, annealing temperature, and concentrations of primer, AmpliTaq Gold, and magnesium were shown to be optimal yet robust enough to withstand moderate variations without affecting genotype analysis. Environmental, matrix and standard source analyses revealed an ability to obtain complete genotypes in all sample types except those exposed to 80 degrees C for 12-48 days. Finally, comparison of genotype results from the PowerPlex 16 System with other commercially available systems on non-probative reference and forensic samples showed consistent results.     

Driver and front seat passenger fatalities associated with air bag deployment. Part 2: A review of injury patterns and investigative issues

Assessment of the role of air bag deployment in injury causation in a crash of any severity requires analysis of occupant, vehicle, and impact data. The potential injurious role of an air bag is independent of crash severity and is more obvious in minor collisions, particularly those involving "out-of-position" occupants. Factors such as occupant height and other constitutional and medical factors, intoxication, age, type, and proper use of other restraint systems, pre-impact braking and multiple impacts can contribute to an occupant being "out-of-position." Two injury mechanisms are described in out-of-position occupants: "punch-out" when the individual covers the air bag module before deployment and "membrane-force" when the occupant contacts a partly deployed air bag. Each mechanism is associated with injury patterns. In adults, "punch-out" can cause thoraco-abdominal trauma and "membrane-force" loading can lead to craniocervical injury. This can also occur in short-statured occupants including children subjected to both types of loading. In more severe collisions, other factors, e.g., intrusion, steering column and seatbelt loading and other occupant compartment contacts, can contribute to trauma.     

Role of alcohol in heroin overdose

The relationship between ethanol and risk of heroin overdosage was studied. Statistical processing of the results of forensic chemical analysis (460 expert evaluations) carried out in Chelyabinsk Regional Bureau of Forensic Medical Expert Evaluations in 2000 was carried out. The results of morphine and ethanol measurements in the blood and urine from corpses where deaths ensued from narcotic or ethanol poisoning, were analyzed. The concentrations of morphine in the blood and urine were measured on a gaseous chromatographer with mass-selective detector (Hewlett Packard HP 6890/HP-5972). Methods for measuring urinary and blood morphine are described. The results of statistical analysis demonstrated relationships between the age and ethanol concentrations in the blood and urine; blood ethanol and total urinary and blood morphine concentrations; blood concentration of free morphine and presence of 6-monoacetylmorphine in the blood. The authors conclude that the presence of ethanol in the blood together with morphine drastically augments the risk of rapid death from respiration arrest. It can also lead to a relatively high risk of overdosage in experienced narcomaniacs using heroin and ethanol.     

Crystallization of cerebrospinal fluid in cases of death from ischemic heart disease and ethanol poisoning

Crystallographic analysis of the cerebrospinal fluid (CSF) was carried out in 18 cases of death from coronary disease and 19 cases of death from ethanol poisoning. The crystallograms were evaluated visually and by the stereoscopic picture. Specific features of the CSF crystal colonies growth in subjects dead from the above conditions are determined.