Evaluation of six presumptive tests for blood, their specificity, sensitivity, and effect on high molecular-weight DNA

Luminol, leuchomalachite green, phenolphthalein, Hemastix, Hemident, and Bluestar are all used as presumptive tests for blood. In this study, the tests were subjected to dilute blood (from 1:10,000 to 1:10,000,000), many common household substance, and chemicals. Samples were tested for DNA to determine whether the presumptive tests damaged or destroyed DNA. The DNA loci tested were D2S1338 and D19S433. Leuchomalachite green had a sensitivity of 1:10,000, while the remaining tests were able to detect blood to a dilution of 1:100,000. Substances tested include saliva, semen, potato, tomato, tomato sauce, tomato sauce with meat, red onion, red kidney bean, horseradish, 0.1 M ascorbic acid, 5% bleach, 10% cupric sulfate, 10% ferric sulfate, and 10% nickel chloride. Of all the substances tested, not one of the household items reacted with every test; however, the chemicals did. DNA was recovered and amplified from luminol, phenolphthalein, Hemastix, and Bluestar, but not from leuchomalachite green or Hemident.     

Computation of likelihood ratios in fingerprint identification for configurations of any number of minutiae

Recent court challenges have highlighted the need for statistical research on fingerprint identification. This paper proposes a model for computing likelihood ratios (LRs) to assess the evidential value of comparisons with any number of minutiae. The model considers minutiae type, direction and relative spatial relationships. It expands on previous work on three minutiae by adopting a spatial modeling using radial triangulation and a probabilistic distortion model for assessing the numerator of the LR. The model has been tested on a sample of 686 ulnar loops and 204 arches. Features vectors used for statistical analysis have been obtained following a preprocessing step based on Gabor filtering and image processing to extract minutiae data. The metric used to assess similarity between two feature vectors is based on an Euclidean distance measure. Tippett plots and rates of misleading evidence have been used as performance indicators of the model. The model has shown encouraging behavior with low rates of misleading evidence and a LR power of the model increasing significantly with the number of minutiae. The LRs that it provides are highly indicative of identity of source on a significant proportion of cases, even when considering configurations with few minutiae. In contrast with previous research, the model, in addition to minutia type and direction, incorporates spatial relationships of minutiae without introducing probabilistic independence assumptions. The model also accounts for finger distortion.     

Violent and sexual offences: a validation of the predictive quality of the PCL:SV in Switzerland

Used to diagnose psychopathy, the Psychopathy Checklist: Screening Version (PCL:SV) is still rarely used in the German-speaking part of Europe. The aim of the present study was to conduct a first-time evaluation of the predictive validity of the PCL:SV for sexual and violent recidivism in the German language area. PCL:SV scores for 96 violent and sexual offenders in Switzerland were assessed. These assessments were based on data taken from the forensic psychiatric expert opinions. The scores were then compared to subsequent recidivism as shown in the official criminal records. ROC analysis indicated a cut-off score of 14 for maximized overall predictive accuracy. Consistent with various results from past research in North America and Europe, the PCL:SV yielded a satisfying predictive accuracy (ROC area=.69). This degree of accuracy demonstrates the PCL:SV's usefulness for risk assessment of sexual and violent delinquency in the Swiss cultural and German language area.     

Work and mental health: learning from return-to-work rehabilitation programs designed for workers with musculoskeletal disorders

Despite the high costs associated with mental health problems in the workplace, few studies have yet been published on the design and evaluation of return-to-work rehabilitation programs for workers with mental health problems. In fact, the best-documented return-to-work rehabilitation programs concern workers with musculoskeletal disorders (MSKD). For this clientele, a disability paradigm has been adopted which explains the multicausality of work disability. Long-term work disability is no longer seen simply as the consequence of impairment, but rather as the result of interactions between the worker and three main systems: the health care, work environment and financial compensation systems. A return to work is thus influenced by a complex set of interrelated factors that must be taken into account in any intervention. Parallels can inevitably be drawn in the field of mental health in the workplace, where individual and organizational factors are involved and must be taken into account in the return-to-work process. This paper presents the first results of an exploratory study aimed at determining the possible links between work rehabilitation programs for workers with MSKD and those for workers with mental health problems. To this end, the components of a work rehabilitation program for workers with MSKD, the Therapeutic Return to Work (TRW) program which addresses psychological factors, work environmental factors and factors related to the involvement of the various stakeholders in the rehabilitation process, are described through a multiple-case analysis and mapping of interventions. The results support the relevance of adopting the disability paradigm and considering the return-to-work clinical activities conducted with workers with MSKD (and their mechanisms of action) in the design of work rehabilitation programs for workers with mental health problems.     

Simultaneous analysis of six amphetamines and analogues in hair, blood and urine by LC-ESI-MS/MS. Application to the determination of MDMA after low ecstasy intake

A rapid and sensitive method using LC-MS/MS triple stage quadrupole for the determination of traces of amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"), 3,4-methylenedioxyethamphetamine (MDEA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB) in hair, blood and urine has been developed and validated. Chromatography was carried out on an Uptisphere ODB C(18) 5 microm, 2.1 mm x 150 mm column (Interchim, France) with a gradient of acetonitrile and formate 2 mM pH 3.0 buffer. Urine and blood were extracted with Toxitube A (Varian, France). Segmented scalp hair was treated by incubation 15 min at 80 degrees C in NaOH 1M before liquid-liquid extraction with hexane/ethyl acetate (2/1, v/v). The limits of quantification (LOQ) in blood and urine were at 0.1 ng/mL for all analytes. In hair, LOQ was <5 pg/mg for MA, MDMA, MDEA and MBDB, at 14.7 pg/mg for AP and 15.7 pg/mg for MDA. Calibration curves were linear in the range 0.1-50 ng/mL in blood and urine; in the range 5-500 pg/mg for MA, MDMA, MDEA and MBDB, and 20-500 pg/mg for AP and MDA. Inter-day precisions were <13% for all analytes in all matrices. Accuracy was <20% in blood and urine at 1 and 50 ng/mL and <10% in hair at 20 and 250 pg/mg. This method was applied to the determination of MDMA in a forensic case of single administration of ecstasy to a 16-year-old female without her knowledge during a party. She suffered from hyperactivity, sweating and agitation. A first sample of urine was collected a few hours after (T+12h) and tested positive to amphetamines by immunoassay by a clinical laboratory. Blood and urine were sampled for forensic purposes at day 8 (D+8) and scalp hair at day 60 (D+60). No MDMA was detected in blood, but urine and hair were tested positive, respectively at 0.42 ng/mL and at 22 pg/mg in hair only in the segment corresponding to the period of the offence, while no MDA was detectable. This method allows the detection of MDMA up to 8 days in urine after single intake.     

A GC/MS study of the drying of ballpoint pen ink on paper

The determination of the age of an ink entry from a questioned document is often an essential problem and a controversial issue in forensic sciences. Therefore, it is important to understand the aging process of the different components found in ink. The aim of this work was to study the drying process of ballpoint ink, characterised by the disappearance of volatile solvents from the ink entry. Phenoxyethanol is of particularly high interest as it is found in more than 80% of the blue ballpoint pens at different concentrations. Liquid extraction followed by splitless gas chromatography/mass spectrometry in the selected ion mode was used to measure the quantitative decrease of solvents from ink entries made with a blue Parker ballpoint pen. Quantities of ethoxyethoxyethanol, dipropylene glycol, phenoxyethanol and phenoxyethoxyethanol were studied in ink entries up to 1.5 years old, thus allowing to calculate aging curves for this particular pen. The low quantities of solvents (in the microgram range for a 1 cm ballpoint entry) were found to decrease quickly after deposition of the ink on paper through the competitive processes of evaporation and diffusion. Losses of up to 75% of solvents were observed after a few seconds. The amount of ethoxyethanol stopped decreasing after about 10 days (quantities reached the nanogram range for a 1 cm ballpoint entry), while the aging curves of dipropylene glycol, phenoxyethanol and phenoxyethoxyethanol level off considerably after 2 weeks. It was observed that ethoxyethanol, dipropylene glycol and phenoxyethanol can also migrate from one sheet of paper to another if placed close enough (e.g. in a book or a stack of papers), therefore contamination from fresh ink strokes from other paper sheets has to be taken into account for those solvents. In this paper we demonstrate that differentiation between fresh ink (<2 weeks) and older inks is possible under laboratory storage conditions. For real cases samples, more parameters have to be studied and other possible pathways have to be considered.     

Development of a harmonised method for the profiling of amphetamines: IV. Optimisation of sample preparation

The suitability of liquid-liquid extraction (LLE) and solid-phase extraction (SPE) for the preparation of impurity extracts intended for gas chromatographic profiling analyses of amphetamine were evaluated. Both techniques were optimised with respect to the extraction of selected target compounds by use of full factorial designs in which the variables affecting the performance were evaluated. Test samples consisted of amphetamine synthesised by the Leuckart reaction, by reductive amination of benzyl methyl ketone and by the nitrostyrene route. The performance of LLE and SPE were comparable in terms of repeatability and recovery of the target compounds. LLE was considered the better choice for the present harmonised amphetamine profiling method due to the lack of information on the long-term stability of SPE columns.     

对全球化的思考

全球化在加速各国融入世界体系进程的同时,也带来了生态环境、能源、人口等一系列全球性问题,这些问题可以通过多极化得以更好的解决。中国作为最大的发展中国家,应该并且能够在国际舞台上发挥更为重要的作用。     

European integration from the agency theory perspective

European integration is a process in which national governments look for higher levels of integration and promote new requests for allocations from the supranational authority while the balance between the benefits and costs of the supranational collective action becomes increasingly favourable. This process may be analyzed as an agency problem where different national governments, acting as principals, try to lead a single agent—the supranational authority—to make a decision on the level of integration. In this paper, decisions on integration of equilibrium are studied as the result of a non co-operative two-stage game, where national governments outline their political support strategies in the first stage and the supranational authority decides the level of integration in the second stage. JEL Classification D72     

Institutionalizing uncertainty: the choice of electoral formulas

Taken from an infinite set of divisors methods, the D’Hondt formula is the unique rule that maximizes the minimum number of seats for parties exceeding average size but not surpassing an absolute majority of the votes. This property is also shared, in the quota set of methods, by the Droop formula. At the same time, these two methods are those most commonly observed in practice. This paper relates the property stated to the observed facts. If parties try to maximize the minimum number of seats for a given share of votes, then the D’Hondt formula should be chosen. This choice is consistent with rational parties that make institutional choices in an uncertain environment.