The effects of chemical and heat maceration techniques on the recovery of nuclear and mitochondrial DNA from bone

Forensic anthropologists use a number of maceration techniques to facilitate skeletal analysis of personal identity and trauma, but they may unwittingly eliminate valuable DNA evidence in the process. This study evaluated the effect of 10 maceration methods on gross bone structure and the preservation of DNA in ribs of 12 pigs (Sus scrofa). A scoring system was applied to evaluate the ease of maceration and resulting bone quality while DNA purity was quantified by optical densitometry analysis, followed by polymerase chain reaction (PCR) amplification of three mitochondrial and three nuclear loci. The results demonstrated that while mitochondrial DNA could be amplified for all experiments, cleaning treatments using bleach, hydrogen peroxide, ethylenediaminetetraacetic acid/papain, room temperature water and detergent/sodium carbonate followed by degreasing had low DNA concentrations and failed to generate nuclear PCR products. In general, treatments performed at high temperatures (90 degrees C or above) for short durations performed best. This study shows that traditionally "conservative" maceration techniques are not necessarily the best methods to yield DNA from skeletal tissue.     

Detection and quantification of the age-related point mutation A189G in the human mitochondrial DNA

Mutation analysis in the mitochondrial DNA (mtDNA) control region is widely used in population genetic studies as well as in forensic medicine. Among the difficulties linked to the mtDNA analysis, one can find the detection of heteroplasmy, which can be inherited or somatic. Recently, age-related point mutation A189G was described in mtDNA and shown to accumulate with age in muscles. We carried out the detection of this 189 heteroplasmic point mutation using three technologies: automated DNA sequencing, Southern blot hybridization using a digoxigenin-labeled oligonucleotide probe, and peptide nucleic acid (PNA)/real-time PCR combined method on different biological samples. Our results give additional information on the increase in mutation frequency with age in muscle tissue and revealed that the PNA/real-time PCR is a largely more sensitive method than DNA sequencing for heteroplasmy detection. These investigations could be of interest in the detection and interpretation of mtDNA heteroplasmy in anthropological and forensic studies.     

A review of the analysis of vegetable oil residues from fire debris samples: analytical scheme, interpretation of the results, and future needs

This paper reviews the literature on the analysis of vegetable (and animal) oil residues from fire debris samples. The examination sequence starts with the solvent extraction of the residues from the substrate. The extract is then prepared for instrumental analysis by derivatizing fatty acids (FAs) into fatty acid methyl esters. The analysis is then carried out by gas chromatography or gas chromatography-mass spectrometry. The interpretation of the results is a difficult operation seriously limited by a lack of research on the subject. The present data analysis scheme utilizes FA ratios to determine the presence of vegetable oils and their propensity to self-heat and possibly, to spontaneously ignite. Preliminary work has demonstrated that it is possible to detect chemical compounds specific to an oil that underwent spontaneous ignition. Guidelines to conduct future research in the analysis of vegetable oil residues from fire debris samples are also presented.     

The impact of general versus specific expert testimonyand eyewitness confidence upon mock juror judgment

Subjects (n=128) initially viewed an eyewitness of high or low confidence. Subsequently, participants viewed a psychologist who gave either espert testimony on the unreliability of eyewitness identification, specific expert testimony, or no expert (control) testimony. Subjects viewing expert testimony believed the eyewitness identified the gunman significantly less often, gave the defendant lower guilt ratings, estimated a lower general percentage of correct identifications under similar circumstances, estimated a lower percentage of general accurate eyewitness testimony, and gave significantly lower ratings to the belief that one can generally tell from eyewitness confidence whether an eyewitness is accurate than subjects in control conditions. Significant differences were also obtained between general and specific expert testimony. Participants viewing specific expert testimony estimated lower general percentages of correct identifications under the circumstances of the crime and reported relying more upon the psychologist's testimony than subjects viewing general expert testimony. Additionally, subjects viewing general expert testimony had significantly less confidence in their gunman vs. innocent person decision than subjects in specific testimony or control conditions. Subjects who viewed the high confidence eyewitness decided that the eyewitness correctly identified the gunman more often, gave the defendant higher guilt ratings, and estimated the general percentage of accurate eyewitness testimony to be significantly higher than jurors in low eyewitness confidence groups. The finding that jurors may continue to rely on eyewitness confidence to gauge the accuracy of the witness even after viewing expert testimony is discussed.     

The forensic science use of reflective ultraviolet photography

Reflective ultraviolet photography has many forensic science applications particularly in child abuse, rape, homicide, and bite mark cases. The potential of this relatively simple and inexpensive procedure has not been fully explored. The procedure for its use in bite mark cases is presented.     

The role of insecure attachment and gender role stress in predicting controlling behaviors in men who batter

The authors hypothesized that masculine gender role stress would mediate the relationship between insecure attachment and controlling behaviors in a sample of men who batter. To examine this hypothesis,143 men who were court mandated to attend a batterers' intervention program in a northeastern state completed measures including the Controlling Behavior Index, the Gender Role Stress Scale, the Relationship Questionnaire, and the Marlowe-Crowne Social Desirability Scale. After controlling statistically for social desirability, results indicated that both fearful attachment and gender role stress significantly predicted controlling behaviors, with gender role stress partially mediating the relationship between fearful attachment and controlling behaviors. The discussion focuses on the importance of understanding partner abuse through a gendered context.     

The Impact of Distributive and Procedural Justice on Social Service Workers

The concepts of fairness and justice are embodied within the organizing principle of social justice. Although social justice is a primary focus of social work, social service workers are not always treated with fairness by their own employers. The results from a survey of 255 social service employees from a variety of agencies in Northwest Ohio indicate that distributive justice and procedural justice, two dimensions of organizational justice, are both significant predictors of job satisfaction and organizational commitment, with procedural justice having two to three times the impact of distributive justice.