Determination of illicit drugs in seized materials: role of sampling and analysis in estimation of measurement uncertainty

The determination of illicit active ingredients in seized materials, in order to assess penal or administrative offences, is routinely carried out in many forensic toxicology laboratories. This paper presents main features of the protocol adopted in the Authors' laboratory for the above investigations. In particular, sampling and analysis are considered as the same measurement process quantifying their combined contribution to overall measurement uncertainty. Aspects concerning representative sampling in the case of single and multiple items are discussed. The effects of material heterogeneity are considered by analyzing separately distinct primary samples taken from different parts of the sampling target. Possible errors due to particles dimension that could arise when sub-sampling are also considered. Analytical precision, bias and other matrix effects are studied in order to quantify the component of the overall measurement uncertainty associated to the analysis of prepared test samples. Typical scenarios arising when measurement results are used to assess compliance with specification limits are also discussed revealing the crucial role of measurement uncertainty.     

Political competition and politician quality: evidence from Italian municipalities

We use data from Italian local level governments for the years 1985?C2008 to investigate whether political competition affects the quality of politicians, as measured by some ex-ante characteristics such as educational level and type of job held. We handle endogeneity problems through an instrumental variable approach using as an instrument for political competition a variable taking into account whether the previous Municipal Council survived until the end of its legislative term. Two Stage Least Square estimates support the view that political competition positively affects politician quality. Results are robust to different measures of political competition and to different estimation strategies.     

Leaders, voters and activists in the elections in Great Britain 2005 and 2010

Discussion of the relationship between parties and the electorate is often based on the notion of partisan constituencies, that parties adopt policy positions that correspond to the average position of the party supporters. In contrast, the Downsian “spatial model” assumes that parties are purely opportunistic and maneuver to gain as many votes as possible. A third, more empirical model, based on the early work of Stokes, assumes that voter choice is based on the evaluation of each of the party leader’s competence or ability to deliver policy success. Such an evaluation can be provided by individual voter overall assessment in terms of the leaders’ character traits.This paper attempts to relate these three classes of models by examining the elections in Great Britain in 2005 and 2010. Using the British Election Study, we construct spatial models of these elections in Great Britain as well as in the three regions of England, Scotland and Wales. The models incorporate the electoral perceptions of character traits. We compare the equilibrium vote maximizing positions with the partisan positions, estimated by taking the mean of each of the parties voters’ preferred positions. We define an equilibrium to be a stable attractor if the vote share at the equilibrium exceeds the share at the partisan position by a significant proportion (determined by the implicit error of the stochastic model). We infer that none of the equilibria are stable attractors, and suggest that the partisan positions are also preferred by the party activists, the key supporters of each party.     

The price of personalizing politics: Political distrust and economic performance in Latin America, 1996–2006

While research has provided evidence that culture and institutional performance shape individual level trust in political institutions, scholars have neglected to adequately estimate the effect of political institutions and macroeconomic conditions on trust. Using data from the World Value Surveys for eleven Latin American cases, we test if countries with “partyizing” electoral systems - those with rules that encourage voters to hold the party, not individuals, accountable for government performance - experience lower levels of distrust in political parties and the legislature in times of poor economic conditions than those countries with “personalizing” electoral rules. Our analysis shows that the macro political and economic context largely conditions the impact of culture and institutional performance on political trust.     

STR data for the 15 AmpFlSTR identifiler loci in the Western Romanian population

Allele frequencies for the 15 tetranucleotide short tandem repeat loci contained in the AmpFlSTR Identifiler kit were obtained from a population sample of 219 unrelated individuals born in the western part of Romania.     

Age estimation by pulp/tooth ratio in canines by peri-apical X-rays

Estimation of age in individuals has received considerable attention in forensic science, in which it is a widely used method for individual identification, together with paleo-demographic analyses to establish mortality patterns in past populations. The present investigation, which is a continuation of a previously published pilot study, was conducted to examine the possible application of the pulp/tooth area ratio by peri-apical images as an indicator of age at death. A total of 200 peri-apical X-rays of upper and lower canines were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. They belong to the Frassetto osteological collection of Sassari (Sardinia) and are housed in the Museum of Anthropology, Department of Experimental and Evolutionistic Biology, University of Bologna. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio on upper (x(1)) and lower (x(2)) canines. Very good agreement was found between intraobserver measurements. Statistical analysis was performed in order to obtain multiple regression formulae for dental age calculation, with chronological age as dependent variable, and gender, and upper and lower canines as independent variables. Stepwise regression analysis showed that gender did not contribute significantly to the fit (p=0.881) whereas variables x(1) and x(2) and the first-order interaction between them did. These two variables explained 92.5% of variations in estimated chronological age and the residual standard error was 4.06 years. Lastly, two simple linear regression equations were obtained for age estimation using canines from the maxilla and mandible separately. Both models explained 86% of variations in estimated chronological age and allowed an age-at-death estimate with a residual standard error of about 5.4 years.     

Psychological adjustment in a forensic sample: relationship with approach- and avoidance-coping typologies

Most studies that relate coping strategies with psychological symptoms usually consider a single coping dimension. This means that interpretation of the results is unclear and only partially true as subjects activate different types of coping strategies simultaneously when faced with a stressor. The objective of the present study is to analyze the relationships between coping and psychopathology in young inmates, taking into account the number of approach and avoidance answers simultaneously. The results show that the inmates with above-average scores in avoidance coping and below average in those of approach (coping responses inventory--adult form, [CRI-A]) show higher symptomatology (MMPI-2) than the inmates who obtain above-average scores in both avoidance and approach strategies. It can be deduced that it is not the high use of avoidance coping that is related to psychopathology, but rather the combined use of many avoidance strategies and few approach strategies. The convenience of jointly taking into account both types of coping is discussed.     

Age estimation by pulp/tooth ratio in canines by mesial and vestibular peri-apical X-rays

Changes in the size of the pulp canal, caused by apposition of secondary dentine, are the best morphometric parameters for estimating age by X-rays. The apposition of secondary dentine is the most frequently used method for age estimation in adult subjects. In two previous papers, we studied the application of the pulp/tooth area ratio by peri-apical X-rays as an indicator of age at death. The aim of the present study was to test the accuracy of age evaluation by combined analysis of labio-lingual and mesial peri-apical X-rays of lower and upper canines. A total of 200 such X-rays were assembled from 57 male and 43 female skeletons of Caucasian origin, aged between 20 and 79 years. For each skeleton, dental maturity was evaluated by measuring the pulp/tooth area ratio according to labio-lingual and mesial X-rays on upper (x(1), x(2)) and lower (x(3), x(4)) canines. Very good agreement was found between intra-observer measurements. Statistical analysis showed that all variables x(1), x(2), x(3), and x(4) and the first-order interaction between x(1) and x(3) contributed significantly to the fit, so that they were included in the regression model, yielding the following regression formula: Age = 120.737 - 337.112x(1) - 79.709x(2) - 364.534x(3) - 65.655x(4) + 1531.918x(1)x(3) . The residual standard error of estimated ages was 3.62 years, with 94 degrees of freedom, and the median of the residuals was -0.155 years, with an interquartile range of 4.96 years. The accuracy of the method was ME = 2.8 years, where ME is the mean prediction error. The model also explained 94% of total variance (R(2) = 0.94).