Impairment of performance by alcohol and diazepam (author's transl)]

An investigation was carried out on the effect of the intake of diazepam and alcohol on simple performance tests. The combined administration of diazepam and alcohol led to an increase of the plasma diazepam concentration as compared to that obtained after diazepam without alcohol. Furthermore, after combined intake of diazepam and alcohol a decrease of performance was observed, that was significantly higher, than the effects obtained after either alcohol or diazepam alone. This impairment was especially noticeable duirng the first hour of the experiment, i.e. until the plateau of the diazepam plasma concentration was reached, while afterwards a correlation between diazepam plasma concentration and impairment of performance could not be established. The relevance of these findings for the interpretation of diazepam plasma concentrations in relation to the impairment of performance are discussed.     

Sales and Use Tax Simplification and Voluntary Compliance

Because of difficulties collecting sales taxes on Internet sales, several states have engaged in an effort (the Streamlined Sales Tax Project, SSTP) to simplify their sales tax systems. One hope among SSTP proponents is that a simplified system will result in Internet vendors voluntarily collecting the sales tax. We address two issues:

• ? Will states adopt the extensive reforms proposed by the SSTP?
• ? Will vendors voluntarily collect the sales tax?

We argue that states are unlikely to adopt extensive reforms, but if they did, many vendors would voluntarily collect sales taxes.     

On the Robustness and Validity of Groups

In response to Nagin's comment on our paper, Methodological Sensitivities to Latent Class Analysis of Long-Term Criminal Trajectories, we reconsider the robustness and validity of group-based approaches to criminal trajectories and introduce additional issues for future research. We emphasize the limitations of typological approaches and the dangers of reifying the idea of distinct offender groupings for research and policy. We also clarify misunderstandings about the use of hierarchical linear models for studying trajectories of crime. Our basic conclusion is that methods in criminology need to be more tightly linked with theory.     

STR analysis of artificially degraded DNA-results of a collaborative European exercise

Degradation of human DNA extracted from forensic stains is, in most cases, the result of a natural process due to the exposure of the stain samples to the environment. Experiences with degraded DNA from casework samples show that every sample may exhibit different properties in this respect, and that it is difficult to systematically assess the performance of routinely used typing systems for the analysis of degraded DNA samples. Using a batch of artificially degraded DNA with an average fragment size of approx. 200 bp a collaborative exercise was carried out among 38 forensic laboratories from 17 European countries. The results were assessed according to correct allele detection, peak height and balance as well as the occurrence of artefacts. A number of common problems were identified based on these results such as strong peak imbalance in heterozygous genotypes for the larger short tandem repeat (STR) fragments after increased PCR cycle numbers, artefact signals and allelic drop-out. Based on the observations, strategies are discussed to overcome these problems. The strategies include careful balancing of the amount of template DNA and the PCR cycle numbers, the reaction volume and the amount of Taq polymerase. Furthermore, a careful evaluation of the results of the fragment analysis and of automated allele calling is necessary to identify the correct alleles and avoid artefacts.     

Y-chromosomal STR haplotypes in a population sample from continental Greece, and the islands of Crete and Chios

Eight Y chromosome short tandem repeat (STR) polymorphisms (DYS19, DYS385, DYS389I, DYS389II, DYS390, DYS391, DYS392, and DYS393) were analyzed in the sample of 117 unrelated Albanian males living in Kosovo. A general STR allelic frequency pattern in the Albanian population from Kosovo corresponds to other European populations. Fourty six haplotypes were observed in single copy. The most frequent haplotypes were (DYS19-DYS385-DYS389I-DYS389II-DYS390-DYS391-DYS392-DYS393) 14-11/11-13-29-24-11-13-13 (10.26%), 14-14/17-12-28-24-10-11-12 (9.40%), 13-16/18-13-30-24-10-11-13 (9.40%), and 14-17/17-13-31-24-10-11-13 (9.40%).