Debugging Decomposition Data—Comparative Taphonomic Studies and the Influence of Insects and Carcass Size on Decomposition Rate

Abstract:  Comparison of data from a variety of environments and ambient temperatures has previously been difficult as few studies used standardized measures of time/temperature and decomposition. In this paper, data from previous studies and recent experiments are compared using simple conversions. These conversions allow comparison across multiple environments and experiments for the first time. Plotting decomposition score against logADD allows the exponential progression of decomposition to be expressed as a simple linear equation. Data comparison from many environments and temperatures shows no difference in decomposition progression when measured using Accumulated Degree Days. The major effector of change in rate was insect presence, regardless of depositional environment, species, or season. Body size is significant when carcasses are accessed by insects; when insects are excluded, while bodies are indoors, submerged, or buried, then decomposition progresses at the same rate regardless of body size.     

Stature estimation from fragmentary femora: a revision of the Steele method

The skeletal remains presented to forensic anthropologists are often fragmentary. Previously described methods of estimating stature from segments of long bones have not proved satisfactory because of the difficulty involved in identifying the precise anatomical landmarks by which they are defined. This study represents an assessment of the feasibility of stature estimation from fragmentary femora. A sample of 200 males and females, blacks and whites (total sample = 800), was obtained from the Terry Collection. New regression equations for the estimation of maximum femur length and stature from three well-defined and easy-to-measure segments of the femur are presented. This technique represents an improvement over methods currently in use for estimating stature from femur fragments; the location of the anatomical landmarks and the accuracy of the prediction are enhanced. The applicability of these formulae to a modern forensic sample is addressed with regard to secular trends in stature increase and changes in body segment proportions.     

Satisfaction with body image for early adolescent females: The impact of pubertal timing within different school environments

During adolescence dramatic physical changes take place which the individual must incorporate into his or her evolving body image. The impact of different school environments on this incorporation process is explored using data on 225 White females from a longitudinal study. Differences in physical characteristics between early, middle, and late developers were assessed each year. The effects of pubertal timing on satisfaction with body image dimensions and self-esteem were then explored for sixth- and seventh-graders within different school environments. Reference group theory was used to examine three alternative hypotheses. Early versus late onset of menarche had different effects on certain aspects of satisfaction with body image, depending on the school environment. Results support the strength of the cultural ideal of thinness for women, but no other hypothesis had consistent support. The findings indicated the need to consider a multiplicity of factors in relation to specific body image dimensions.This study has been funded by NIMH grant R01 MH-30739 and a grant from the William T. Grant Foundation. In addition, the work of the second author has been supported by a Research Development Award from the National Institute of Mental Health, #2 K02 MH-41688.Received his Ph.D. from the University of Minnesota. Current research interests include stress and coping in adolescence, the role of social relationships in problem behavior, and the effects of different school contexts.Received her Ph.D. from Columbia University. Research interests include the social and psychological effects of puberty and sex differences in adolescence.Received M. A. in clinical child psychology from Ohio State University. Main interests are developmental aspects of body-image and research on personality disorders.     

The Effect of Clothing on the Rate of Decomposition and Diptera Colonization on Sus scrofa Carcasses

Twenty Sus scrofa carcasses were used to study the effect the presence of clothing had on decomposition rate and colonization locations of Diptera species; 10 unclothed control carcasses were compared to 10 clothed experimental carcasses over 58 days. Data collection occurred at regular accumulated degree day intervals; the level of decomposition as Total Body Score (TBS_surf), pattern of decomposition, and Diptera present was documented. Results indicated a statistically significant difference in the rate of decomposition, (t₄₂₇ = 2.59, p = 0.010), with unclothed carcasses decomposing faster than clothed carcasses. However, the overall decomposition rates from each carcass group are too similar to separate when applying a 95% CI, which means that, although statistically significant, from a practical forensic point of view they are not sufficiently dissimilar as to warrant the application of different formulae to estimate the postmortem interval. Further results demonstrated clothing provided blow flies with additional colonization locations.     

The Effect of Repeated Physical Disturbance on Soft Tissue Decomposition—Are Taphonomic Studies an Accurate Reflection of Decomposition?*

Although the relationship between decomposition and postmortem interval has been well studied, almost no studies examined the potential effects of physical disturbance occurring as a result of data collection procedures. This study compares physically disturbed rabbit carcasses with a series of undisturbed carcasses to assess the presence and magnitude of any effects resulting from repetitive disturbance. Decomposition was scored using visual assessment of soft tissue changes, and numerical data such as weight loss and carcass temperature were recorded. The effects of disturbance over time on weight loss, carcass temperature, soil pH and decomposition were studied. In addition, this study aimed to validate some of the anecdotal evidence regarding decomposition. Results indicate disturbance significantly inversely affects both weight loss and carcass temperature. No differences were apparent between groups for soil pH change or overall decomposition stage. An insect-mediated mechanism for the disturbance effect is suggested, along with indications as to why this effect may be cancelled when scoring overall decomposition.     

Evaluation of a Teen Dating Violence Prevention Intervention among Urban Middle-School Youth Using Youth Participatory Action Research: Lessons Learned from <Emphasis Type="Italic">Start Strong Boston</Emphasis>

Almost half of adolescents aged 11 to 14 have dated and between 10 and 30% report experiencing Teen Dating Violence (TDV). However, there are no evidence-based TDV prevention interventions designed for afterschool, community-based settings with middle-school youth, in high-risk neighborhoods. Start Strong Boston (SSB) is a model that fills all three gaps, founded on partnerships between the Boston Public Health Commission, community afterschool sites, academic experts and evaluators, and youth. Here, we describe the SSB program and discuss how this collaboration built upon successes of this peer-engaged intervention, by developing and implementing a youth participatory action research (YPAR) evaluation study of SSB. Use of the YPAR framework tested the feasibility of employing Peer Researchers in an interdisciplinary evaluation team. We describe how through participation in evaluation research, Peer Researchers improve professional and leadership skills while informing measurement and conceptualization of a program affecting their own neighborhoods. Lessons learned are presented.