This investigation explored the utility of mean osteon area, perimeter, and circularity as parameters for distinguishing between human and non-human bone. Although species of origin can be readily ascribed to undamaged remains, this evaluation can become difficult, if not impossible, when bone macrostructure has been obscured through taphonomic processes such as thermal alteration or extreme fragmentation. If mature Ovis aries, domestic sheep, and human osteon metrics area are significantly different, then osteon metrics can be useful parameters for distinguishing between these tissues and, thus, determining the species of origin for a bone sample of unknown provenience. This investigation consisted of histological analysis of cortical bone from 35 O. aries rib samples. O. aries samples were acquired from Riverslea Farm in Epping, New Hampshire (n = 30) and Cedar Ledge Farm in Somers, Connecticut (n = 5). Mean osteon area, perimeter, and circularity were assessed by manually tracing calibrated digital images of rib cross-sections using the ImageJ software from the National Institute of Health (NIH, Bethesda, MD). The results presented here indicate (1) that there are statistically significant histomorphometric differences between species, specifically goat and sheep, (2) that there are significant histomorphometric differences based on the anatomical, intra-rib sampling location, and (3) that the osteon metrics discussed here are may be poor parameters by which to ascribe the species of origin for remains with no known provenience, based on comparisons with findings from other publications.

Dental cementum is a mineralized tissue that coats the root of a tooth and anchors it into the alveolar socket via the periodontal ligament. Cementum is continuously deposited and mineralized throughout the life of a tooth, preserving the complex developmental processes of root formation in optically distinct histologic layers (Hillson, 1996; 2005). Analysis of these features has several anthropological applications, specifically the analysis of cementum increments and their utility in estimating age and season at death in humans for establishing a more specific post-mortem interval (PMI). Wedel (2007) conducted a pilot study to determine whether dental cementum increment analysis can be used to establish season of death in humans. Wedel (2007) hypothesized that by identifying the timing of the transition between the bands of arrested development and the bands of increased deposition, dental cementum increment analysis can be used to identify the season at death in humans. It was demonstrated that cementum increment analysis is 99% accurate in estimating whether an individual died in either a fall/winter or spring/summer season. The purpose of the present study was to estimate whether cementum bands could accurately be assigned to fall/winter, spring/summer seasons based on their optical properties as being light or dark. A total of 143 teeth of known age and known extraction date drawn from the Boston University Collection and the Antioquia Modern Skeletal Reference Collection in Medellín, Colombia were analyzed using recent protocols for preparation, sectioning, and observing increment lines in cementum. Dental cementum increment analysis was found to be between 61.54% and 71.15% successful in accurately correlating the nature of the last cementum increment to season at death using a combination of image evaluation and through focus evaluation methods on two distinct geographic samples. A through focus evaluation was found to be more successful at identifying the last band formed and is recommended for microscopic analyses estimating season at death using dental cementum increments. Geographic origin did not have a significant influence over the accuracy of the method to estimate season at death, however the results of this study suggest that teeth extracted from cadavers versus living individuals may have some influence on the accuracy of cementum increments to estimate season at death. No significant influence of sex, age, or tooth type on the identification and correlation of the last band formed were detected in this study. An interobserver analysis using digital images of a randomly selected sample of 45 sections found that interobserver agreement on the nature of the last band formed occurred in only 28.8% of the sample. Inconsistencies in the nature of the last band formed between multiple sections prepared from the same tooth were observed, which calls into question the validity of using cementum increments to estimate season at death. The potential limitations for the reliability of using dental cementum increment analysis to determine season at death in humans include the lack of a standardized method for preparing adequate sections for viewing cementum increments, and the subjectivity of identifying the last band in a given section. It is concluded that if the validity and reliability of dental cementum increment analysis as a method for age estimation can be established and configured to meet the criteria of the Daubert Standard, specifically in the adoption of a standardized protocol of analysis, then the validity of using this method for estimating season at death can be further considered.

The classic metaphyseal lesion (CML) is considered to be a strong indicator of physical abuse in infants. These fractures extend through the metaphysis of a long bone near the growth plate, disrupting the trabecular bone structure. The mechanism(s) behind this fracture type are not entirely understood. The present study investigated experimentally the possible loading conditions required to generate CMLs in pig models. Fifty hindlegs from stillborn pigs were tested in torsion using a mechanical testing machine and a digital torque wrench. Fractures to the metaphysis that resemble CMLs were produced during a combined loading event which applied torsion to the knee joint (distal femur, proximal tibia, and proximal fibula). A visual assessment of the physeal surface of each specimen was performed after testing, and classic metaphyseal lesions were identified by comparison with findings from Love et al. (2011). The only fractures seen in both the femora and tibiae were CMLs, with both bone types having 60% (30 of 50) total fractures. The frequency of total fractures on fibulae was less, with 42% (21 of 50). The frequency of CMLs in the fibulae, however, is lower than the frequency of total fractures (38%, n=50), as physeal fractures also presented in some of those bones. Thus, the CML was the most common type of fracture produced due to the torque applied to the bones during testing. When assessing the number of CMLs that occurred on each limb, nine limbs had only one CML present, while 28 limbs had one or more CMLs. Additionally, complete CMLs made up 51.9% (41 of 79) of the total number, while partial made up 48.1% (38 of 79). Out of the 150 bones tested, 79 (52.7%) showed fractures resembling CMLs in human infants. A fracture was 35% more likely to occur in a femur or a tibia than in a fibula, and multiple CMLs per specimen were more common than single CMLs. The physeal surfaces of the specimens recorded as having CMLs showed damage to the trabecular bone. Three physeal fractures were noted; one Type IV physeal fracture on a proximal tibia and one on a proximal fibula, and a Type II physeal fracture on a proximal fibula. No diaphyseal fractures of any kind were produced. Further investigation of these conditions is encouraged to gain more insight into the injury mechanism.

The accurate estimation of the postmortem interval (PMI) is one of the most important determinations in a forensic investigation of decomposing human remains. Forensic entomology has gained popularity in death investigation due to its reliability and precision in the estimation of the minimum postmortem interval (mPMI). Forensically significant insects are mainly necrophagous species, which feed only on decomposing animal matter, and the most common necrophagous insects are the blowflies (Diptera: Calliphoridae). Estimations of the mPMI by entomological methods are made using the known developmental rates of various species of blowfly and via the successional patterns of the carrion insect community in a given region. It is generally assumed that blowflies oviposit quickly after death, so in many cases this time may equate to the time since death. The precision of mPMI estimations based on the developmental rates of blowflies often relies on this assumption. Rainfall may effect decomposition by inhibiting access of insects to the cadaver or carcass for oviposition. The current study investigated the effects of rainfall on blowfly activity, behavior, and overall decomposition of decaying animal material in an outdoor environment in the northeastern United States, conducted at the Boston University Outdoor Research Facility (ORF). It was hypothesized that natural rainfall, typically light to moderate in the geographic area of study, will disturb initial blowfly activity by acting as a physical barrier, diminishing access to the remains, and creating a delay in colonization and subsequent larval development. This hypothesized delay would result in an underestimation of the mPMI by entomological methods when rainfall has occurred. Also examined were several questions about the nocturnal behavior of blowflies and their activity in heavy rain. In the experimental trial 12 pig (Sus scrofa) heads were exposed under normal conditions (N; no rain controls), and 15 pig heads were exposed under rainy conditions (R; rain treatment), split into uncovered (N, n=6; R, n=5), covered (NC, n=5; RC, n=5), and covered partially (RCP, n=5) treatments. Additionally, there were three pig heads used in a preliminary trial and three pig heads exposed in an active rain trial. Generally, the results show that while a negative correlation exists between the amount of rainfall experienced and the coded number of flies observed, the light to moderate rainfall typical of many rainy days in the northeastern Unites States will not totally inhibit blowfly activity or disturb established maggot masses. A one-way analysis of variance (ANOVA) determined that there was no statistically significant difference (p > 0.05) between the N, NC, R, RC, and RCP treatments in the number of days it took to reach the advanced decomposition stage. While constant, heavy rainfall may inhibit blowfly activity; the results suggest that the irregularity of natural rainfall would rarely produce the conditions necessary for this to make a significant impact estimation of the PMI by entomological methods, although further studies are needed to confirm this conclusion. The results show a positive correlation between solar radiation and the coded number of flies observed. Time of day as a function of the coded number of flies observed during the first 48 hours of exposure forms a bimodal bell curve, confirming that blowflies are diurnal in their natural environment. Additionally, evidence of scavenging by turkey vulture (Cathartes aura) and some unknown animal(s) was observed. The results of this study illustrate the complicated, multivariable nature of the process of decomposition. This study provides preliminary data on the effect of rainfall on blowfly activity and overall decomposition, while future studies will be required to determine the effects of the duration and the intensity of rainfall.

Traditionally, pre-contact Native Americans have served as a biological reference for identifying modern Asian individuals in aspects of the biological profile due to their distantly shared genetic history, although this assumption remains largely untested. This study explores the craniomorphic variability between Asian and Asian-derived groups to ascertain whether they can be differentiated using population-specific models. Cranial and mandibular nonmetric trait data were recorded on pre-contact Native Americans (n=150) and compared within a statistical framework to cranial trait data for modern Thai (n=150) and Japanese (n=150) individuals. Chi-square analyses indicate that the groups exhibit statistically significant differences in their trait expressions. Of the 35 traits analyzed, 31 differ significantly between the groups. Binary logistic regression equations for differentiating the Japanese, Thai, and Native Americans are presented, and cross-validated correct classification rates range 60.0-90.0%. Further, the inclusion of sex into the logistic regression equations failed to improve their accuracies. The results indicate that the Native American and Asian groups are not skeletally homogenous due to divergent population histories, and that numerous cranial and mandibular nonmetric traits are resolute enough to detect differences within and between Asian and Asian-derived groups. Thus, this study highlights the utility of nonmetric traits in identifying individuals beyond the traditional African (“Black”), (“White”), and Asian groupings.

Ancestry estimation of skeletonized remains by forensic anthropologists is conducted through comparative means, and a lack of population-specific data results in possible misclassifications. This is especially germane to individuals of Latin American ancestry. Generally, each country in Latin America can trace their ancestry to three parental groups: Indigenous, European, and African. However, grouping all Latin American individuals together under the broad “Hispanic” category ignores the specific genetic contributions from each parental group, which is variable and dependent on the population histories and sociocultural dynamics of each country. This study analyzes the craniometric ancestry of Hispaniola (the Dominican Republic and Haiti) using the island’s history, along with 190 cranial Computed Tomography (CT) scans (f = 103; m = 87), to determine similarities and differences between the two groups. A total of 12 linear discriminant function analyses produced cross-validated classification accuracies of 75.0 – 83.3% for females, 71.8 – 87.5% for males, and 72.0 – 82.2% for pooled sexes. This study demonstrates that, despite sharing a small island, Dominican and Haitian individuals can be differentiated with a fair amount of statistical certainty, which is possible due to complex socio-cultural, -political, and –demographic factors that have maintained genetic heterogeneity. Moreover, the discriminant functions provided here can be used by the international forensic science community to identify individuals living on Hispaniola.

No description available.

The present study aimed to test the accuracy of using diffuse idiopathic skeletal hyperostosis (DISH) to make positive identifications using the method of antemortem and postmortem radiographic comparison. An online survey was developed to evaluate whether DISH is a feature of the skeleton that can be used in radiographic image comparison. Three digital radiographic images from 51 individuals were gathered for use in this study: one image taken at a baseline date (Group A), one image taken within 2 years from baseline (Group B), and one image taken greater than 4.5 years from baseline (Group C). A total of 40 survey participants were tasked with comparing between a simulated “antemortem” image and a “postmortem” image from living patients and identifying which image pair represented the same individual at different time intervals. Information about survey participants’ field, degree, experience working with radiographs, and familiarity with DISH were also recorded. Accuracy, sensitivity, and specificity were measured. Series 1 compared Group A images to Group B images and resulted in an accuracy of 87.3%, sensitivity of 46.9%, and specificity of 94.3%. Series 2 compared Group A images to Group C images and resulted in an accuracy of 83.4%, sensitivity of 34.3%, and specificity of 95.8%. The study concluded that the characteristics of DISH did not prove reliable for making positive identifications but established that DISH could be used to narrow down potential matches.

The present study involves a multivariate assessment of the success of evidence recovery by searchers from various backgrounds and skill levels. Volunteers representing four experience levels (civilian volunteers, first year forensic anthropology graduate students, second year forensic anthropology graduate students, and first responders) conducted line searches of mock crime scenes, flagging items of forensic significance with pin flags. The groups were then briefly trained in human skeletal remains recovery, and implemented this training through a second set of mock scene searches. Recovery rates were compared across pre- and post-training trials and across searcher groups in order to determine the influence of searcher training and experience on search success. The results of this study reveal not only the percentage of evidence that was recovered by search teams, but exhibits the degree to which experience and training played a role in evidence recovery.

Frontal sinus variation has been used in forensic anthropology to aid in positive identification since the 1920s. As radiographic technology has evolved, so has the quality and quantity of data that radiologists and anthropologists can collect during an individual’s lifetime. This has led to new methodology when comparing antemortem and postmortem radiographic images. The current study aims to look at frontal sinus morphology and dimensional variations on computed tomography (CT) scans, as these are currently the most commonly collected images showing the frontal sinus in its entirety used in clinics in the United States. This study assessed 307 individuals for the morphological analysis and 325 individuals in the dimensional analysis. These individuals represented females and males from Asian, African, European, and Latin American derived groups. It is hypothesized that frontal sinus shape variations will cluster based on assigned sex and population affinities. Similarly, it is hypothesized that dimensional variation, specifically the maximum height, maximum width, and maximum depth, will show statistically significant clustering based on assigned sex and population affinities. The frontal sinus outlines from the CT images were transferred into SHAPE v1.3 in order to run an elliptical Fourier analysis. The dimensional data was measured directly from the images using a MicroDicom viewer. All of the statistical analyses, including Pearson’s Chi-squared and ANOVA tests, were run in R studio. Results indicated that morphologically there is no statistically significant clustering based on assigned sex or population affinity. However, there was statistically significant clustering dimensionally when tested against both assigned sex and population affinity using an ANOVA, indicating that the interactive effects of sexual dimorphism and population affinity influence the dimensions but not the shape of the frontal sinus. These results add to the foundational knowledge that practitioners have surrounding frontal sinus indicating that assigned sex and population affinity have impact on the approximate dimensions of this structure while these variables do not have a statistically significant effect on morphological variation. The results also speak to the idiosyncratic nature of the frontal sinus and bolster confidence using morphological variations as a mean to individuate.