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.     

The Impact on Juror Verdicts of Judicial Instruction to Disregard Inadmissible Evidence: A Meta-Analysis

The effect on juror verdicts of judicial instructions to disregard inadmissible evidence was evaluated using meta-analysis. One hundred seventy-five hypothesis tests from 48 studies with a combined 8,474 participants were examined. Results revealed that inadmissible evidence (IE) has a reliable effect on verdicts consistent with the content of the IE. Judicial instruction to ignore the inadmissible evidence does not effectively eliminate IE impact. However, if judges provide a rationale for a ruling of inadmissibility, juror compliance may be increased. Contested evidence ruled admissible accentuates that information, resulting in a significant impact on verdicts. Suggestions for how the courts may mitigate the impact of inadmissible evidence more effectively are discussed.     

Where the homeless come from: A study of the prior address distribution of families admitted to public shelters in New York City and Philadelphia

Abstract

This study investigates hypotheses regarding the association of census tract variables with the risk for homelessness. We used prior address information reported by families entering emergency shelters in two large U.S. cities to characterize the nature ofthat distribution.

Three dense clusters of homeless origins were found in Philadelphia and three in New York City, accounting for 67 percent and 61 percent of shelter admissions and revealing that homeless families’ prior addresses are more highly concentrated than the poverty distribution in both cities. The rate of shelter admission is strongly and positively related to the concentration of poor, African‐American, and female‐headed households with young children in a neighborhood. It is also correlated with fewer youth, elderly, and immigrants. Such areas have higher rates of unemployment and labor force nonpartici‐pation, more housing crowding, more abandonment, higher rates of vacancy, and higher rent‐to‐income ratios than other areas.     

Comment on James R. Cohen's “abandoned housing: Exploring lessons from Baltimore”

Abstract

For most cities, the possibility of transforming unused property into community and city assets is as yet hypothetical. Fiscal constraints limit the amount of land acquisition, relocation, and demolition that cities can undertake. Private investors, unsure of which neighborhoods have a chance of becoming self‐sustaining, are reluctant to take risks in untested markets.

Cities need to create citywide planning strategies for land aggregation and neighborhood stabilization and to develop analyses of the risks and opportunities associated with redevelopment opportunities in specific markets. Research seems sorely needed. Although the policy world cannot and will not stand still waiting for academics to design the perfect study or to collect all the data to model the potential effects of various policy options and investments, analysis that can play a more immediately supportive role can and should be done now.     

Choice of law and the home-court advantage: evidence

This paper tests three separate hypotheses about inherent biasesin the application of modern choice of law rules: (1) Brilmayer's1980 hypothesis that such rules camouflage 'pro-resident, pro-forum-law,pro-recovery' biases, (2) Borchers's 1992 hypothesis that courtsdo not consistently apply the principles of the choice of lawrule they claim to be applying, and (3) an economic hypothesis,presented in the paper, that only a 'pro-forum-law' bias isunambiguously consistent with economic efficiency, simply becauseit conserves the resources of the court and bar in the forumstate. I find relatively strong support for the 'pro-recovery'bias of courts, weaker support for 'pro-forum-law' bias, andreject the 'pro-resident' bias. If anything, states retainingthe rigid choice of law rules are more likely to favor theirresidents. Moreover, I reject Borchers's claim that courts donot take the modern approaches seriously. Indeed, in general,they follow Borchers's own predictions.     

Public shelter admission rates in Philadelphia and New York City: The implications of turnover for sheltered population counts

Abstract

Previous estimates of the size and composition of the U.S. homeless population have been based on cross‐sectional survey methodologies. National enumeration efforts have yielded point‐prevalence estimates ranging from 0.11 to 0.25 percent of the population. This study reports data from shelter databases in Philadelphia and New York City that record identifiers for all persons admitted and so make possible unduplicated counts of users.

Unduplicated counts of shelter users yield annual rates for 1992 of about 1 percent for both cities and rates near 3 percent over three years in Philadelphia (1990–92) and over five years (1988–92) in New York City. The annual rates are three times greater than rates documented by point‐prevalence studies. Shelter bed turnover rates are reported, as are average monthly first admission and readmission counts over a two‐year period. Implications for future research and public policy are discussed.     

Predictors of Homelessness Among Families and Single Adults After Exit From Homelessness Prevention and Rapid Re-Housing Programs: Evidence From the Department of Veterans Affairs Supportive Services for Veteran Families Program

This article assesses the extent and predictors of homelessness among veterans (both veterans in families with children and single adults veterans) exiting the Supportive Services for Veteran Families (SSVF) program, which is a nationwide homelessness prevention and rapid re-housing program geared primarily toward those experiencing crisis homelessness. Among rapid re-housing participants, 16% and 26% of single adult veterans experienced an episode of homelessness at 1 and 2 years post-SSVF exit; the comparable figures at those follow-up times for veterans in families were 9.4% and 15.5%, respectively. Relatively fewer single adult veterans and veterans in families receiving homelessness prevention services experienced an episode of homelessness at 1 and 2 years post-SSVF exit. veteran-level characteristics, including age, gender, prior history of homelessness, and recent engagement with U.S. Department of Veterans Affairs (VA) health care, were generally more salient predictors of homelessness following SSVF exit than variables measuring SSVF program factors or community-level housing market conditions.