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.     

Population genetics of nine short tandem repeat loci: allele frequency distribution in a Brazilian population sample

Gene and genotype frequencies in relation to the D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317, and D7S820 loci were determined in a sample of 290 unrelated individuals (204 Caucasians and 86 mulattoes) living in the city of S?o Paulo, Brazil. The sex test Amelogenin was also performed in all subjects from our sample, revealing the expected sex in all instances. Allele frequency data obtained from the analysis of these samples were in the usual range of other population groups with similar racial background. In the sample of Caucasian individuals, panmictic proportions were ruled out in relation to TPOX and CSF1PO loci, but only in the latter was the overall frequency of heterozygotes significantly less than expected. In the sample of mulattoes, Hardy-Weinberg proportions were rejected in relation to FGA and CSF1PO loci, but in no instance were the overall numbers of heterozygotes different from the corresponding expected ones under panmixia. Taking into account all this and also the number of tests performed, the degree of genetic heterogeneity of Brazilian populations, and the critical level reached by the significant results (1% < alpha<5%), the departures from panmixia here observed can be considered to be negligible in altering significantly biologic relationship odds calculated under the assumption of random matings.     

A Proposal to Use Mediation and “Night Correspondents” to Curb Urban Violence in Cergy,France

Mediators, called night correspondents, have been hired by some French municipalities to reduce violence in the neighborhoods, using dialogue and daily help (in repairing things in particular). Night correspondents seem to be especially appropriate to reduce incivility, i.e. daily nonrespectful behavior. This essay reports on the results of two surveys conducted in Cergy by MBA students of two seminars at ESSEC business school. Although the recommendation of hiring night correspondents has not been followed yet in Cergy, several decisions have been taken by the social lessors and other public actors in the neighborhoods aimed at reducing violence, through mediation processes.     

Comparison of Anonymous Versus Confidential Survey Procedures: Effects on Health Indicators in Dutch Adolescents

Self-report questionnaires are frequently used in youth research, but doubt remains whether total anonymity affects the results. This study compared the responses of 704 mainly 16–17-year-old adolescents to self-report measures of various health indicators in 2 groups: anonymous and confidential collection. For most health indicators no significant differences were found. Perceived health, use of alcohol, and aggressive behavior (for boys) were reported significantly less frequently in the confidential group (small effect size). It appeared that pupils with high scores on social desirability do not respond differently at most health indicators in the 2 conditions. For most health characteristics, epidemiologically useful outcomes may be derived from confidential self-report measures, which are also valuable for detecting individual at-risk children. Similar studies in lower grades and other types of education should confirm the results.Youth Department, Municipal Health Service Rotterdam area. Main research interests are emotional and behavioral problems of adolescents, youth health care, monitoring.Youth Department, Municipal Health Service Rotterdam area. Main research interests are emotional and behavioral problems of adolescents, youth health care, monitoring.Research Department, Municipal Health Service Rotterdam area. Major research interests include emotional and behavioral problems of adolescents, suicidal behavior, youth health care, monitoring.     

Monotone Comparative Statics for Models of Politics

We elucidate a powerful yet simple method for deriving comparative statics conclusions for a wide variety of models: Monotone Comparative Statics ( Milgrom and Shannon 1994 ). Monotone comparative static methods allow researchers to extract robust, substantive empirical implications from formal models that can be tested using ordinal data and simple nonparametric tests. When these methods apply, they can replace a diverse range of more technically difficult mathematics (facilitating richer, more realistic models), assumptions that are hard to understand or justify substantively (highlighting the political intuitions underlying a model's results), and a complicated set of methods for extracting implications from models. We present an accessible introduction to the central monotone comparative statics results and a series of practical tools for using these techniques in applied models (with reference to original sources, when relevant). Throughout we demonstrate the techniques with examples drawn from political science .     

Authoritarian Attitudes, Democracy, and Policy Preferences among Latin American Elites

This article examines the prevalence and consequences of authoritarian attitudes among elites in Argentina, Brazil, Chile, Colombia, Mexico, and Venezuela. We focus on the connection between antidemocratic elite attitudes and support for democracy; the causes and effects of authoritarian attitudes among elites and their implications for authoritarianism; and the impact of authoritarian attitudes beyond social policy preferences to other policy areas that have indirect implications for order. Contrary to some of the literature, we find that antidemocratic attitudes affect elites' support for democracy. Our analysis also speaks to the debate on the origins of authoritarianism. Much of the evidence supports Altemeyer's notion that perceived threat raises levels of authoritarianism, rather than Feldman's contention that threat strengthens the influence of authoritarian attitudes. Finally, we demonstrate that there is a broader influence of authoritarian attitudes on economic policy preferences, but only where those policies appear to have implications for social order.     

Does democracy “suffer” from diversity? Issue representation and diversity in senate elections

Several recent studies examine the degree to which congressional behavior affects candidates’ electoral fortunes (e.g., Carson, 2005). Research examining electoral competitiveness (Bond, Campbell, & Cottrill, 2001; Koetzle, 1998) and roll call voting (Bailey & Brady, 1998; Jones, 2003) finds that diversity in the electorate mediates the impact of numerous variables upon election outcomes and representation. However, the influence of diversity on other modes of representation – such as the policy positions taken by Senate candidates–remains unexplored. We investigate the link between representation and Senate candidates’ policy positions and thereby examine the degree to which voter diversity affects candidates’ policy responsiveness. We find that diversity significantly influences responsiveness, both directly and indirectly – candidates in homogenous states are more responsive to constituents than are candidates in heterogeneous states.     

Nomenklatura,state monopoly,and private enterprise

Using a behavioral model of political decisionmaking, it is argued that an increasing population size and/or an increasing efficiency of production in a private enterprise economy relative to a centrally planned economy may create the conditions for a self-interested nomenklatura in a Soviet-type economy to consider a transition to a market economy. This transition may be thwarted, however, by the threat for prospective private enterpreneurs of exploitation after the change of regime. Some form of political pluralism guaranteeing sufficient political influence to private entrepreneurs appears to be required for a successful transition. The analysis shows that such a combined political and economic reform can be in the interest of the nomenklatura, thereby providing an endogenous behavioral explanation for a change of regime.