Evaluation of Raman spectroscopy for the analysis of colored fibers: a collaborative study

A collaborative study on Raman spectroscopy was carried out by members of the ENFSI (European Network of Forensic Science Institutes) European Fibres Group (EFG) on three dyed fibers: two red acrylics and one red wool. Raman instruments from six different manufacturers were tested as well as nine different laser wavelengths ranging from blue (lambda = 458 nm) to near infrared-NIR (lambda = 1064 nm). This represents the largest comparison study of Raman analytical parameters carried out on identical fiber samples. For the chosen fiber and dye samples, red lasers (lambda = 633 and 685 nm) gave the poorest spectral quality whereas blue (458 nm), green (514 nm) and near infrared lasers (785, 830 and 1064 nm) provided average results. Blue (488 nm) and green lasers (532 nm) globally gave the best quality spectra. Fluorescence problems were often encountered with some of the excitation wavelengths and therefore a flexible Raman instrument equipped with different lasers can be recommended to measure forensic fiber samples. The instrument should also be equipped with a Raman microscope in order to be able to focus on a single fiber. This study shows that Raman spectroscopy usually enables the identification of the main dye present in a colored fiber; however, minor dye components are much more difficult to detect. SERRS (Surface Enhanced Resonance Raman Scattering) techniques give an improvement of the dye's spectral intensity but no spectral improvement was observed for the two red acrylic and red wool fibers tested.     

Family Representative Payeeship and Violence Risk in Severe Mental Illness

Although representative payeeship is prevalent among people with mental illness and shows promise to positively influence clinically relevant outcomes, research also suggests this legal mechanism could be implemented in ways that are problematic. The current study examined whether family representative payeeship was associated with elevated risk of family violence perpetrated by persons with severe mental illness (SMI). Data were collected every 4 months for 1 year in structured interviews with N = 245 persons with SMI who received disability benefits. Multivariate analyses showed that substance abuse, history of violence, frequency of family contact, and family representative payeeship were associated with elevated odds of family violence. Analyses also showed family contact and family representative payeeship had a cumulative effect on increasing the predicted probability of family violence (controlling for covariates such as violence history and substance abuse). The data shed light on the potential for family representative payeeship to be associated with increased risk of interpersonal conflict and violence in SMI.     

Reducing violence in serious juvenile offenders using intensive treatment

This study reports on the reduction in violent offending in a population of serious and violent juvenile offenders following an intensive institutional treatment program. The treatment group (N=101) is compared to a similar group that was assessed but not treated (N=147). All youth were sent to the program from a juvenile corrections institution where they had received the customary rehabilitation services. The results show a significant reduction in the prevalence of recidivism in the treated group after controlling for time at risk in the community and other covariates. The effects of non-random group assignment were reduced by including a propensity score analysis procedure in the outcome analysis. Untreated comparison youth appeared to be about twice as likely to commit violent offenses as were treated youth (44% vs. 23%). Similarly, treated youth had significantly lower hazard ratios for recidivism in the in the community than the comparison youth, even after accounting for the effects of non-random group assignment.     

Mitochondrial DNA error prophylaxis: assessing the causes of errors in the GEP'02-03 proficiency testing trial

A qualitative and quantitative analytical method was developed and validated for the determination of 49 licit and illicit drugs in oral fluid. Small oral fluid samples, volume 1mL, were collected from volunteers using a modified Omni-Sal device and the analytes were extracted from an oral fluid/buffer mixture using a single Bond Elut Certify solid phase extraction cartridge. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) and gas chromatography-repetitive full scan mass spectrometry (GC-MS) were used in parallel to analyze the extracts for the targeted drugs. Extracts were analyzed by GC-MS in their underivatized form and as their pentafluoropropionyl derivatives. Deuterated internal standards were used for quantification of drugs of abuse by LC-MS-MS to minimize matrix effects. Methadone-d(9) and tumoxetine were used as the internal standards for quantification of non-derivatized and derivatized analytes respectively by GC-MS. Linearity was demonstrated over the range 5-200 ng/mL and limits of detection were less than 4 ng/mL for each drug analyzed. The method demonstrated acceptable recoveries for most of the analytes and good intra- and inter-day precision. Acquisition of data by repetitive full scan GC-MS allows the addition of further analytes to the target menu.     

Measurement Properties of the Communities That Care<Superscript>®</Superscript> Youth Survey Across Demographic Groups

Prevention science has produced information about risk and protective factors that predict adolescent drug use and related problem behaviors. This paper investigates the Communities That Care Youth Survey that measures multiple risk and protective factors. Using a sample of 172,628 students who participated in surveys administered in seven states in 1998, analyses were conducted to test the factor structure of these risk and protective factors and to test the equivalence of the factor models across five racial/ethnic groups (African Americans, Asians or Pacific Islanders, Caucasians, Hispanic Americans, and Native Americans), four grade levels (6th, 8th, 10th, and 12th) and both gender groups. Results support the construct validity of the surveys risk and protective factor scales and indicate that the measures are equally reliable across males and females and five racial/ethnic groups. Implications of these findings for science-based prevention planning are discussed.     

Differences in trauma symptoms and family functioning in intra-and extrafamilial sexually abused adolescents

This study investigated to what extent abuse-related symptoms and family functioning are related to intra- or extrafamilial sexual abuse. One hundred adolescents (12 to 18 years old) were recruited shortly after disclosure of the abuse. Information from the participants was obtained through self-report questionnaires and a semistructured interview. Fifty-three percent of the adolescents reported clinically significant symptoms. Data did not support the idea that intrafamilial sexually abused adolescents report more symptoms than extrafamilial sexually abused adolescents. Type of abuse did not account for the differences and variety of reported symptoms or for differences in family functioning. Family functioning-in particular, lack of cohesion- was an independent contributor to internalizing trauma-related problems.     

Trace analysis of peroxide explosives by high performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (HPLC-APCI-MS/MS) for forensic applications

An HPLC-APCI-MS(/MS) method for the (trace) analysis of the most commonly encountered peroxide explosives, hexamethylenetriperoxidediamine (HMTD) and triacetonetriperoxide (TATP), has been developed. With this method, HMTD and TATP have been analyzed in the same run. (Pseudo-)molecular ions of these peroxides have been obtained as base peak under the same condition. A series of product ions was produced from these pseudo-molecular ions ([HMTD - 1]+ and [TATP + NH4]+) in the MS/MS analysis. We also pioneered in showing that a TATP molecular ion [TATP + H]+ can be observed with HPLC-MS/MS. The limit of detection for HMTD and TATP was 0.26 and 3.3 ng, respectively, on column by HPLC-MS in the Full Scan mode and 0.08 and 0.8, respectively, by HPLC-APCI-MS/MS in Selected Reaction Monitoring (single mass unit) mode. The method presented has been applied successfully for the identification of peroxides in the bulk solid state (powder sample), as well as in post-blast extracts originating from a forensic case. For the post-blast extracts, the use of tandem MS has been shown clearly to be of crucial importance for the identification and detection of the peroxide explosives.