Application of plant DNA markers in forensic botany: genetic comparison of Quercus evidence leaves to crime scene trees using microsatellites

As highly polymorphic DNA markers become increasingly available for a wide range of plant and animal species, there will be increasing opportunities for applications to forensic investigations. To date, however, relatively few studies have reported using DNA profiles of non-human species to place suspects at or near crime scenes. Here we describe an investigation of a double homicide of a female and her near-term fetus. Leaf material taken from a suspect's vehicle was identified to be that of sand live oak, Quercus geminata, the same tree species that occurred near a shallow grave where the victims were found. Quercus-specific DNA microsatellites were used to genotype both dried and fresh material from trees located near the burial site and from the material taken from the suspect's car. Samples from the local population of Q. geminata were also collected and genotyped in order to demonstrate that genetic variation at four microsatellite loci was sufficient to assign leaves to an individual tree with high statistical certainty. The cumulative average probability of identity for these four loci was 2.06x10(-6). DNA was successfully obtained from the dried leaf material although PCR amplification was more difficult than amplification of DNA from fresh leaves. The DNA profiles of the dried leaves from the suspect's car did not match those of the trees near the crime scene. Although this investigation did not provide evidence that could be used against the suspect, it does demonstrate the potential for plant microsatellite markers providing physical evidence that links plant materials to live plants at or near crime scenes.     

Dealing with the Unthinkable: a Study of the Cognitive and Emotional Stress of Adult and Child Homicide Investigations on Police Investigators

Although the death of a child is without doubt one of the most distressing events imaginable, when it occurs in suspicious circumstances, such as at the hand of a parent or close family member, its effects are often more acute and incomprehensible. This paper presents an exploratory study comparing the cognitive and emotional stressors experienced by police when investigating child and adult homicides. The results of an online survey questionnaire with 99 experienced UK police investigators are presented, with key differences found in the cognitive and emotional stress experienced depending on whether the victim is a child or an adult, key differences and similarities identified in the ways investigators deal and cope with adult and child homicide cases, with a tentative discussion of the implications for the well-being and training of police investigators provided.     

Life Satisfaction and Student Engagement in Adolescents

Situated within a positive psychology perspective, this study explored linkages between adolescent students’ positive subjective well-being and their levels of engagement in schooling. Specifically, using structural equation modeling techniques, we evaluated the nature and directionality of longitudinal relationships between life satisfaction and student engagement variables. It was hypothesized that adolescents’ life satisfaction and student engagement variables would show bidirectional relationships. To test this hypothesis, 779 students (53% female, 62% Caucasian) in a Southeastern US middle school completed a measure of global life satisfaction and measures of cognitive, emotional, and behavioral engagement at two time points, 5 months apart. A statistically significant bidirectional relationship between life satisfaction and cognitive engagement was found; however, non-significant relationships were found between life satisfaction and emotional and behavioral student engagement. The findings provide important evidence of the role of early adolescents’ life satisfaction in their engagement in schooling during the important transition grades between elementary and high school. The findings also help extend the positive psychology perspective to the relatively neglected context of education.     

Sir Charles Lucas and The Empire at War

Abstract

This article gives an overview of the British Empire’s participation in the First World War. The roles of Australia, Canada, India, New Zealand and South Africa are well documented but there was also a significant contribution from and impact on the smaller and more peripheral territories. These are well covered in Sir Charles Lucas’s multi-volume series The Empire at War. Although very much of its time, written for and by an imperial elite and now neglected, it remains an invaluable record.     

Recent Developments

International Journal for the Semiotics of Law - Revue internationale de Sémiotique juridique -