Parent and Peer Pathways to Adolescent Delinquency: Variations by Ethnicity and Neighborhood Context

Effects of ethnicity and neighborhood quality often are confounded in research on adolescent delinquent behavior. This study examined the pathways to delinquency among 2,277 African American and 5,973 European American youth residing in high-risk and low-risk neighborhoods. Using data from a national study of youth, a meditational model was tested in which parenting practices (parental control and maternal support) were hypothesized to influence adolescents' participation in delinquent behavior through their affiliation with deviant peers. The relationships of family and neighborhood risk to parenting practices and deviant peer affiliation were also examined. Results of multi-group structural equation models provided support for the core meditational model in both ethnic groups, as well as evidence of a direct effect of maternal support on delinquency. When a similar model was tested within each ethnic group to compare youths residing in high-risk and low-risk neighborhoods, few neighborhood differences were found. The results indicate that, for both African American and European American youth, low parental control influences delinquency indirectly through its effect on deviant peer affiliation, whereas maternal support has both direct and indirect effects. However, the contextual factors influencing parenting practices and deviant peer affiliation appear to vary somewhat across ethnic groups. Overall the present study highlights the need to look at the joint influence of neighborhood context and ethnicity on adolescent problem behavior.     

Meaning in Life as a Mediator of Ethnic Identity and Adjustment Among Adolescents from Latin,Asian, and European American Backgrounds

Establishing a sense of life meaning is a primary facet of well-being, yet is understudied in adolescent development. Using data from 579 adolescents (53% female) from Latin American, Asian, and European backgrounds, demographic differences in meaning in life, links with psychological and academic adjustment, and the role of meaning in explaining associations between ethnic identity and adjustment were examined. Although no generational or gender differences were found, Asian Americans reported higher search for meaning than Latin and European Americans. Presence of meaning was positively associated with self-esteem, academic adjustment, daily well-being, and ethnic belonging and exploration, whereas search for meaning was related to lower self-esteem and less stability in daily well-being. Presence of meaning mediated associations between ethnic identity and adjustment, explaining 28–52% of ethnic identity’s protective effect on development. Ethnic identity thus appears to affect adjustment, in part, through its role in fostering a positive sense of meaning in adolescents’ lives.     

Preparation of Tool Mark Standards with Jewelry Modeling Waxes

Abstract:  This paper presents how jewelry modeling waxes are used in the preparation of tool mark standards from exemplar tools. We have previously found that jewelry modeling waxes are ideal for preparing test tool marks from exemplar tools. In this study, simple methods and techniques are offered for the replication of accurate, highly detailed tool mark standards with jewelry modeling waxes. The techniques described here demonstrate the conditioning and proper use of jewelry modeling wax in the production of tool mark standards. The application of each test tool's working surface to a piece of the appropriate wax in a manner consistent with the tool's design is clearly illustrated. The resulting tool mark standards are exact, highly detailed, 1:1, negative impressions of the exemplar tool's working surface. These wax models have a long shelf life and are suitable for use in microscopic examination comparison of questioned and known tool marks.     

Developmental Validation of the PrepFiler™ Forensic DNA Extraction Kit for Extraction of Genomic DNA from Biological Samples*

Abstract: The PrepFiler? Forensic DNA Extraction Kit enables isolation of genomic DNA from a variety of biological samples. The kit facilitates reversible binding of DNA with magnetic particles resulting in high DNA recovery from samples with very low and high quantities of biological materials: 0.1 and 40 μL of human blood (donor 2) provided 14 and 2883 ng of DNA, respectively. Following the revised SWGDAM guidelines, performance of the developed method was investigated using different sample types including saliva on swabs, semen stains on cotton fabric, samples exposed to environment, samples with polymerase chain reaction (PCR) inhibitors, blood stains (on denim, cotton cloth, and FTA^® paper), and touch evidence‐type samples. DNA yields for all samples tested were equal or better than those obtained by both phenol–chloroform extraction and commercial kits tested. DNA obtained from these samples was free of detectable PCR inhibitors. Short tandem repeat profiles were complete, conclusive, and devoid of PCR artifacts.     

Practical Aspects of Analyzing Vegetable Oils in Fire Debris*

Abstract: Vegetable oils undergo burning, self‐heating, and spontaneous ignition, resulting in their presence in fire debris. As these processes can affect the fatty acid content of vegetable oils, it is important that debris be properly handled in order to obtain reliable and informative data. This research investigated changes in vegetable oil content as a result of storage conditions and different types of burning. Material spiked with vegetable oils and burned was stored under various long‐term conditions, and debris was tested by heating overnight using passive headspace concentration. Results indicated that refrigeration is ideal for fire debris samples suspected of containing vegetable oils and that including passive headspace concentration in the analytical scheme would not affect oils. Spontaneous ignition experiments were conducted to compare the effects of various burning processes on vegetable oil content. Vegetable oils that experienced nonpiloted ignition, self‐heating, and spontaneous ignition produced noticeably different chromatograms from those that underwent piloted ignition.     

Measurement of teen dating violence attitudes: an item response theory evaluation of differential item functioning according to gender

Accurate assessment of attitudes about intimate partner violence is important for evaluation of prevention and early intervention programs. Assessment of attitudes about cross-gender interactions is particularly susceptible to bias because it requires specifying the gender of the perpetrator and the victim. As it is likely that respondents will tend to identify with the same-gender actor, items and scales assessing attitudes about intimate partner violence may not have equivalent measurement properties for male and female respondents. This article examines data from 2,575 high school students who participated in a teen-dating violence intervention study. The majority of participants were Latino (91%), and the sample was nearly evenly split with respect to gender (51% female). Items from two scales (boy-on-girl violence, 4 items; girl-on-boy violence, 5 items) reflecting teens' attitudes about dating violence were calibrated with the graded item response theory (IRT) model and evaluated for differential item functioning (DIF) by gender. A total of three items, two from the girl-on-boy violence scale and one from the boy-on-girl violence scale, were identified as functioning differently for girls and boys. In all cases where DIF was detected, the item's attitudinal statement was easier to accept for the gender group that was portrayed as victim rather than perpetrator. For both scales, accounting for the identified DIF influenced inferences about the magnitude of mean differences in attitudes between boys and girls. These results support the use of IRT scores that account for DIF to minimize measurement error and improve inferences about gender differences in attitudes about dating violence.     

Identification of forensically important Chrysomya (Diptera: Calliphoridae) species using the second ribosomal internal transcribed spacer (ITS2)

The identification of forensically important blowflies of the genus Chrysomya (Diptera: Calliphoridae) may be hampered by their close morphological similarities, especially as immatures. In contrast to most previous studies, the utility of a nuclear rather than mitochondrial genetic marker was investigated to solve this problem. The second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA) was amplified and sequenced from all nine Chrysomya species known from Australia. Difficulties encountered with direct sequencing of ITS2 for Chrysomya flavifrons necessitated cloning prior to sequencing for this species, which revealed a low level (0-0.23%) of intraindividual variation. Five restriction enzymes (DraI, BsaXI, BciVI, AseI and HinfI) were identified that were able to differentiate most members of the genus by polymerase chain reaction (PCR) restriction fragment length polymorphism (PCR-RFLP). The PCR-RFLP analysis revealed characteristic restriction profiles for all species except the closely related species pairs Chrysomya latifrons+Chrysomya semimetallica and Chrysomya incisuralis+Chrysomya rufifacies. Ch. incisuralis and Ch. rufifacies were able to be separated using the size differences resulting from amplification of the entire ITS region. The lack of intraspecific ITS2 sequence variation among eight Ch. incisuralis specimens was verified by the identical restriction profiles generated from these specimens. A DNA-based approach, such as PCR-RFLP, has the capacity to be useful for the identification of forensic entomological evidence in cases where morphological characters are unreliable.     

Detection and quantification of low levels of benzoylecgonine in equine urine

Cocaine (COC) is a highly addictive plant alkaloid expressing strong psychostimulatory effect. It has no medical use in equine veterinary practice. The contamination of the environment with cocaine such as its presence on the US paper currency has been reported few times. There are anecdotal reports of low benzoylecgonine (BE) concentrations (usually much less than 100 ng/mL) being found in urine of race horses. In order to protect horsemen against harsh penalties associated with the presence of trace amounts of BE in horse urine as a result of environmental contamination, in February 2005 the Illinois Racing Board issued new medication rules that established the threshold level of 150 ng/mL for BE in equine urine. The penalties associated with this rule provide for increasing fines ($250, $500, $1000) with successive positive reports against a trainer for levels of BE below 150 ng/mL. A total of 19,315 urine samples were collected over the 2-year period of time from winning horses (both harness and thoroughbred) at race tracks in Illinois for routine drug screening (ELISA). The presence of BE was confirmed by GC/MS in 28 urine samples (0.14%). The concentration range for BE in harness horses (21 detections) was < 5-91 ng/mL, and for thoroughbred (seven detections) was 7-52 ng/mL. To date, the laboratory has not reported concentrations of BE that exceed the established threshold concentration of 150 ng/mL.