An investigation into the use of calculating the first derivative of absorbance spectra as a tool for forensic fibre analysis.

A range of fibre samples was measured using J&M MSP400 and J&M MSP800 microspectrophotometers across the visible and UV/visible wavelength ranges respectively. The first derivative of the absorbance spectra was then calculated and studied. When the absorbance spectra produced for some samples were broad and featureless, the first derivative spectra provided more points of comparison that facilitated discrimination. For many of the samples, calculating the first derivative did not result in any additional discrimination due to the high number of points of comparison present in the absorbance spectra. However, for the samples that exhibited a high level of intra-sample colour variation (e.g. through uneven dye uptake common in cotton and wool, etc.), which was evident in the absorbance spectra, the associated first derivative spectra highlighted this variation between the fibres and could potentially have resulted in false exclusions. The results show that whilst calculating first derivative can be a useful aid in the comparison of spectra, a high degree of caution is required when applying this method to fibres which exhibit a large intra-sample variation in colour.     

Joint custody: a comprehensive review

This article presents a comprehensive overview of joint custody. The history and legislative implications are discussed, as are pertinent issues relative to the reported advantages and disadvantages of joint custody. Finally, the role of the mental health professional in assisting with counseling divorced families either before, during, or after a custody decision is discussed.     

Implications of trombiculid mite bites: report of a case and submission of evidence in a murder trial

Bites of Trombiculid mites implicated a suspect during a homicide investigation. Clinical documentation of the bites, correlation with entomological studies, and submission of evidence at trial are reported. Insects that have a discrete geographic distribution and leave bites of a characteristic nature may have important forensic science implications.     

Military combat, posttraumatic stress disorder, and criminal behavior in Vietnam veterans

Although data are inconclusive, popular perception has linked military combat, posttraumatic stress disorder (PTSD), and criminal behavior. This paper discusses the multifactorial elements of this association that include both conscious and unconscious parameters of psychologic functioning. Testimony on combat-related PTSD has been presented in the courtroom to support veterans' claims of not guilty by reason of insanity (NGRI) and diminished capacity and for consideration during judicial sentencing. Because there is a known connection between the degree of combat involvement and PTSD, verification through collateral sources of the veteran's report of combat experiences is an important component of forensic assessment. The DSM-III-defined diagnosis of PTSD and the presence of a dissociative state have particular relevance in NGRI determinations. In other aspects of the judicial process demonstration of the absolute presence or absence of PTSD is often irrelevant and should be replaced by efforts to establish plausible links between provable combat experiences and the circumstances of the crime.     

What is medical ethics consultation?

What happens when the field of ethics consultation meets the hermeneutics of suspicion.     

Post-injection hybridization of complementary DNA strands on capillary electrophoresis platforms: A novel solution for dsDNA artifacts

Several laboratories have reported the occurrence of a split or n − 1 peak at the vWA locus in PowerPlex^® 16 and PowerPlex^® ES amplification products separated on 4- and 16-capillary electrophoresis instruments. The root cause of this artifact is post-PCR reannealing of the unlabeled, unincorporated vWA primer to the 3′-end of the tetramethylrhodamine (TMR)-labeled strand of the vWA amplicon. This reannealing occurs in the capillary post-electrokinetic injection. The split peak is eliminated by incorporation into the loading cocktail of a sacrificial hybridization sequence (SHS) oligonucleotide that is complementary to the vWA primer. The SHS preferentially anneals to the primer instead of the TMR-labeled strand of the vWA amplicon. In addition, the n − 10/n − 18 artifact that may be seen at the vWA locus was determined to be due to double-stranded amplicon formed post-electrokinetic injection into the capillary. This was also eliminated by adding in two Complementary Oligo Targets (COT1 and COT2) in addition to the SHS oligonucleotide into the loading cocktail. These three oligonucleotides are complementary to the 33 bases at the 5′-end of the unlabeled vWA amplicon strand and the 60 bases at its 3′-end and therefore compete for hybridization to the TMR-labeled amplicon strand. Incorporation of these three oligonucleotides in the Internal Lane Standard 600 (ILS600) eliminate both the split peak and n − 10/n − 18 artifact in PowerPlex^® 16 and PowerPlex^® ES amplification products without affecting sizing of alleles at the vWA locus or any locus in the PowerPlex^® 16, PowerPlex^® Y, PowerPlex^® ES, AmpFlSTR^® Profiler Plus^® ID, AmpFlSTR^® Cofiler^®, and AmpFlSTR^® SGM Plus^® kits.