Estimation of age is a crucial step for the identification of unknown individuals. Age is commonly assessed through macroscopic analytical methods based on the gross-examination of age degenerative changes in the skeleton. The choice of the methods relies on the taphonomic condition of the human remains and/or the skeletal element that is available. In cases of very fragmented bones, microscopic techniques remain one of the few approaches to estimate age. Thus, many histological age estimation methods have been developed for different bones and on different samples in the last forty years. Numerous intrinsic and extrinsic factors influence bone remodelling rates and have shown to affect the accuracy of histological aging methods. The present study investigates rib thin-sections from two Mediterranean samples, aiming to explore the applicability and reliability of histological methods in estimating age within these samples. Standard ribs were obtained from males and females (N = 88, Mean age = 60, SD = 17.90) from two samples, Cretans (Greece) and Greek- Cypriots (Republic of Cyprus). The costal elements were processed histologically according to standard protocols and thirteen raw and composite histomorphometric parameters (frequency number of intact and fragmentary osteons, total osteons, osteon population densities - including OPD(I) and OPD(F) - cortical area, total area, endosteal area, relative cortical area, osteon area, osteon perimeter and osteon circularity) were assessed. Intra- and inter-observer errors were examined. Due to the fragmented nature of the costal elements, sampling error was calculated as a means to explore whether the histological variables vary among six different topographical locations along the rib length. A validation study was carried out by applying four existing histological age prediction equations on the entire dataset and on the sub-datasets (sex and samples separately) in order to verify whether population-specific formulae are required for the Mediterranean samples. The relationship between the histological variables and age, as well as sex and samples, was determined through several statistical tests. Lastly, simple and multiple regression analyses were performed testing all possible combinations of variables. The best models ii were finally selected according to prediction power and goodness of fit indicators. The results from intra- and inter-observer errors indicated that most of the histological parameters achieved high levels of repeatability. The preliminary outcome from the sampling error pilot study suggested low variability among the six thin-sections from each rib. According to the validation study, three of the four age prediction equations resulted in high underestimation of age, indicating that population-specific formulae are needed to provide more accurate age estimates. Most of the histological variables showed a statistically significant correlation with age with some differences observed by sex and by sample. Forty-one models were generated concluding that osteon densities along with rib and osteon measurements formulae produced the most accurate results. The best model generated from the entire dataset included OPD and osteon circularity with a standard error of the estimate of 10.45 years. When sex and samples were separated, the best model selected included OPD and osteon perimeter producing a standard error of the estimate of 8 years for Cypriots. This research demonstrates that quantitative bone histology is a feasible method to estimate age on the Mediterranean samples obtaining errors rates that are in accordance with macroscopic ageing techniques. Inter-population variation in remodeling rates is suggested; however, the inclusion of other bones presenting different remodelling dynamics (such as femora) is recommended to further explore this hypothesis. This study contributes to the creation of population-specific standards for Cretans and Cypriots.

In situations of mass disaster (1), which include airline crashes (2), terrorist attacks (2), large fires (3), and mass homicide (4), the human remains are often damaged beyond recognition (5). In these cases, bones and teeth are potentially the only acceptable source of deoxyribonucleic acid, or DNA (6). Previous studies have evaluated a plethora of techniques to purify DNA from hard tissue, but there is no consensus on the optimal process by which to extract and purify DNA from these samples. Not only are hard tissue samples difficult to process, in many cases the samples are subjected to extreme environmental conditions, such as high temperature. Thus, there is interest in obtaining information on DNA quality from samples exposed to high temperatures (7). This work hopes to fill the gap by: 1) optimizing a DNA extraction protocol from hard tissue; and 2) measuring the degree to which the DNA is degraded in an effort to link the quantity and quality of the DNA recovered to the outer appearance of the tooth. To accomplish this, individual teeth were burned in a furnace at 100 °C, 200 °C, 300 °C, 400 °C, 500 °C, and 600 °C for 10, 20, and 30 minutes. The optimal extraction procedure utilized Amicon® Ultra-4 Centrifugal 30K filter devices and the QIAGEN MinElute Polymerase Chain Reaction (PCR) Purification Kit. Samples were quantified using the Quantifiler® Trio quantification kit to obtain the quantity and quality metrics. After heat exposure, each tooth was photographed and subsequently given a color designation or value: light yellow to beige teeth were assigned a value of 1; dark yellow to orange were assigned a value of 2; brown was assigned a value of 3; shiny black was assigned a value of 4; and black to light gray teeth were assigned a value of 5. Both carbonization and the early stages of calcination were observed. The mass of DNA per mass of tooth was determined by examining quantitative PCR (qPCR) results for both a large and small autosomal fragment. The degradation index, or DI, was also calculated from qPCR measurements. The results demonstrate a strong correlation between the quantity of DNA recovered, the quality of the DNA obtained, and the designated color value. The highest recovery rates were obtained from teeth assigned a color value of 1 (unaltered beige) or 2 (yellow to orange). These teeth were exposed to either room temperature, 100 °C or 200 °C. At temperatures exceeding 300 °C, the amount of DNA recovered drastically decreased and was inconsistent. Some of the samples subjected to temperatures at and above 300 °C resulted in no quantifiable DNA. In contrast, the DI results suggested that when the teeth were subjected to temperatures ≤ 100 °C, the quality of the DNA was good, wherein the DI value was approximately 1. At 200 °C, the temperature began to impact the DI value, which increased with time to the point where a DI was no longer able to be calculated because the large autosomal fragment could not be detected. In conclusion, the current work compares five different methods of DNA extraction to establish a best practice extraction procedure for these difficult samples. Furthermore, this work suggests that examination of the tooth’s appearance can be used to deduce whether successful DNA recovery is likely. In summary, the results demonstrate that when the tooth sample was assigned a color value of 1, the quantity and quality of the DNA obtained was high. Once the color value of the sample rose to 2, the quantity and quality of DNA varied greatly and the probative value of the sample was diminished. Samples that exhibited large color changes or had begun the calcination process resulted in no recoverable DNA.

Cancer is currently the second most common cause of death in the U.S. with over 600,000 people expected to die from cancer this year alone. The diagnosis of cancer steadily increased through most of the 20th century due to a rise in tobacco usage, causing a relatively recent growth in cancer research. In the past several decades, treatments for cancer have been rapidly changing and advancing, and it is vital to understand how these medications affect the human skeleton. Presently, little research has been conducted on how medications alter the human skeleton and impact the biological profile. One of the primary side effects of drug and radiation-based treatments for a neoplasm is cancer treatment-induced bone loss (CTIBL), which may impact the expression of sexual dimorphism in morphological traits. It is hypothesized that CTIBL would decrease the robusticity of sexually dimorphic nonmetric traits and skew the ordinal scores towards gracile. A total of 178 individuals with documented cancer and/or treatment and 178 individuals without documented cancer from the William M. Bass Donated Skeletal Collection at the University of Tennessee, Knoxville, were assessed following conventional sex assessment standards for the skull and os coxa. These methods presented by Buikstra and Ubelaker (1994), Klales et al. (2012), and Walker (2005) were applied to the os coxa and Walker’s (2008) method for the skull. The individuals ranged in age from 26 to 97 years and included 350 European Americans, two African Americans, one Asian/Polynesian, and three Native Americans. The control group was designed to parallel the experimental group by demographic information including sex, ancestry, and age-at-death. The experimental group was also subdivided into two groups that included individuals that underwent chemotherapy and/or radiation (drug subgroup) and individuals who only underwent surgery as a form of treatment (surgery subgroup). Thirty-six randomly selected individuals were also rescored to test for intraobserver agreement. IBM’s Statistical Package for Social Sciences (SPSS) was used to calculate Chi-Square, ANOVA, ANCOVA, and Cohen’s Kappa analyses. The Chi-Square and ANOVA analyses were used to determine if there was any statistically significant relationship between cancer treatment status and the scores of the morphological traits. The results indicated no significant relationship between cancer treatment status and the trait scores (p > 0.05) for all analyses except for the Chi-square analysis of the glabella for females in the pooled sample (p=0.047) and the ANOVA analysis of the ventral arc in the surgery group when sex was not considered (p=0.010). It is possible that these traits are affected by cancer treatment status. However, it is more likely that these results were due to natural variation between the control and experimental groups. Intraobserver agreement was calculated using Cohen’s Kappa analysis. Intraobserver agreement ranged from fair to substantial with most traits indicating moderate intraobserver agreement. Some possible confounders of the study include the unknown duration of cancer treatments, the use of a history of cancer as a proxy for cancer treatment, not knowing when the individual underwent cancer treatment before death, and the assumption that the individuals included in the sample were accurately documented. Cancer Treatment-Induced Bone Loss may only affect bone mineral density as opposed to the expression of sexually dimorphic traits as many of these visually assessed traits are sites of muscle attachments. Though CTIBL does not appear to affect morphological sex assessment, further research should be conducted on the possible effects of CTIBL for other components of the biological profile.

Of the 206 bones that compose an adult skeleton, only a select few are used in the estimation of sex and age. The best indicator of the sex of an adult skeleton is derived from several morphological features of the pelvis. In addition to the pelvis, characteristics of the sacrum, long bones, and skull have been used to estimate sex in adult remains. The most accurate indicators of age-at-death at the present time are related to features of the pubic bone, the auricular surface of the ilium, and the sternal end of the fourth rib. The current project assesses the utility of the sternum for estimating age and sex using two current methods. The two methods in question are those of Bongiovanni and Spradley (2012) for the estimation of sex and Sun et al., (1995) for the estimation of age. The data gathered at the Robert J. Terry Anatomical Skeletal Collection for this study is used to assess the validity and accuracy of the two different methods utilizing a North American population differing from that of Bongiovanni and Spradley (2012). Results showed a high congruence with the results of Bongiovanni and Spradley (2012) in which an overall classification rate of 81.1% was achieved. The cross-validation classifications for males and females were 79.9% and 83.6% respectively and an overall classification rate of 86.7% was achieved using total sternal length (TL). Results also demonstrate that the mean values of sternal index conform to Hyrtl's Law, however the range of values largely overlap, and demonstrates the law's unreliability for sex estimation. Results showed a lack of congruence with the Sun et al., (1995) method reaching a classification rate for exact age estimates of 14.4%. Overall, the utility of the human sternum for sex estimation seems promising and practically simple. The utility of the human sternum for age estimation merits further research into methods that might provide higher classification rates, however, at this time no methods seem worthwhile.

Age-at-death estimation in older adults is complicated because current techniques fail to capture an older individual’s age-at-death in a narrow enough range. This study aimed to test the relationship between osteoporotic change and age-at-death in the form of intracortical porosity. It was hypothesized that as individuals age, osteoporotic processes increase resulting in a higher percentage of intracortical porosity that may correlate with particular age cohorts. Forty ribs were analyzed, ranging in age from 15 to 84. Ribs sections were digitized using a 40X objective on a Nikon E600 microscope equipped with a motorized stage and a Turboscan montaging system (Objective Imaging Inc., UK). Images were made binary using image ImageJ 2.0. Nine measurements and calculations as described by the Agnew and Stout (2012) method were used: total subperiosteal area, endosteal area, cortical area, percent cortical area (%C/T), porosity area, percent porosity area, absolute cortical area, percent absolute cortical area (%CA/T), and the difference between %C/T and %CA/T. The ranges and mean values for intracortical porosity across the sample were calculated. The effect of intracortical porosity on measures of cortical area were interpreted using a calculation of the difference between %C/T and %CA/T. A Two Sample Independent T-Test was performed to see if there was a significant difference between sexes. Regression analyses were conducted to assess correlations between the traits and age-at-death. No significant difference was found between sexes in regards to intracortical porosity or the difference between %C/T and %CA/T. The mean intracortical porosity was found to be 15.30. The mean value of the difference was found to be 6.95%. Measures of intracortical porosity varied from 0.74% - 31.67% while measures of the effect of intracortical porosity varied from 0.32% - 17.85%. No correlation was found between either trait and age-at-death. There are a number of reasons intracortical porosity might not be correlated with an individual’s age-at-death including (1) processes that influence intracortical porosity, (2) hormonal changes, (3) the current understanding of the relationship between aging and bone cell functions. One should still account for intracortical porosity when conducting histomorphometric analyses, as failure to consider it would result in miscalculations.

One role of forensic anthropologists is to create a biological profile to help identify remains. This includes estimating ancestry. Many morphological and metrical methods of ancestry estimation have been created and utilized. This study was aimed at created a simple, metrical analysis of dental arch size and shape to aid in ancestry estimation. Maximum length and width of over 700 dental casts (both maxillary and mandibular) were recorded and statistically analyzed by one-way ANOVA. Measurements were taken using points on teeth rather than on the fragile bone of the maxilla and mandible. It was found that ancestry does affect the size of the maxillary arch but not the mandibular one, but discriminant function analysis showed that ancestry estimation is not possible with the present set of data for either the maxilla or the mandible. Further research will need to be conducted with larger sample sizes of certain populations in order to improve ancestry estimation using this method.

This project examined the effects of burning on saw mark characteristics of isolated semi-fleshed white-tailed deer (Odocoileus virginianus) long bones as a substitute for human remains. Different classes of saws were examined to determine which type of saw mark characteristics are obliterated when burned and which are not. The saw mark characteristics that were examined are superficial false start scratches, false start kerfs, and completely sectioned cuts with breakaway spurs/notches. The long bones were burned at the Boston University School of Medicine using a muffle furnace, at differing temperatures and at differing time increments. The author hypothesized that the higher the temperature and the longer the duration of bone burning, the greater will be the obliterative effect on saw mark characteristics. All samples were examined using a Motic® Digital Light Microscope 12 VDC with a Nikon® MKII Fiber Optic Light attached with accompanying Motic® imaging and measuring software. Distances were measured between striations on complete cuts, false start kerf widths, and false start scratch widths using the Motic® imaging and measuring software. Images were also taken of the cross sections of the kerf floors. The striations on the kerf walls, false start kerf widths, and false start scratch widths were compared to the control samples. Measurements taken from false start scratches, false start kerfs, and complete cuts were averaged and compared to the averages from each temperature and the control samples, to assess the degree of shrinkage from thermal alteration. The false start kerf profile shapes were blindly examined and classified into Class A, B, C, or D(following the system of Symes 1992) and compared to the control samples. Kerf flare and blade drift were examined to determine if thermal alteration obliterated those saw mark characteristics. The chainsaw false start kerfs and complete cuts were examined macroscopically to determine what effects thermal alteration had on those types of marks. All thermally altered samples were assessed for color change, heat-related fracturing, and whether or not the saw marks were still visible. The author found that all saw marks made with the mitre saw, crosscut saw, and bow saw were still visible and identifiable, even in a fractured state and, when burned up to 700°C for one hour. Most of the false start kerf samples were classified into the correct kerf profile shape as outlines in Symes (1992). False start kerfs and complete cuts made with the chainsaw were blindly examined and showed that these marks are distinct and easily identifiable when the bone is completely intact or has very minimal fracturing. The crosscut saw false start scratch and crosscut saw complete cut samples showed signs of shrinkage. The average width of the false start scratch samples burned at 700°C for one hour was about 50% smaller than the control sample's average width. The same was true for the complete cut striation widths. Shrinkage did not appear to alter the crosscut saw false start kerf widths or the bow saw false start scratch widths. For all cuts made with the mitre saw shrinkage did appear to alter the samples. Warping did occur where some of the burned averages were larger than the control sample averages. This suggests that some warping did take place by widening the kerf, thus changing the analysis of the saw mark characteristics. Blade drift and kerf flare were seen in the samples and thus were not affected by thermal alteration. The author's hypothesis was not rejected, because in some cases thermal alteration did modify the saw mark characteristic measurements and in some cases thermal alteration did not alter the measurements. Some of the saw marks were affected by shrinkage, while others were not. False start kerf profile shape classification was not affected by thermal alteration. The chainsaw samples were affected most by the thermal alteration, because of the obliterative effects of heat-related fracturing which progressed generally with the greater temperature.

Estimating sex and age at death are two crucial processes during the creation of a biological profile for a set of skeletal remains. Whether the remains are archaeological or forensic, estimating the sex and age of the individual is necessary for further analysis and interpretation. Specifically, in a medicolegal context, knowing the biological sex and approximate age of the remains assists law enforcement or government agencies in identifying unknown individuals. Since the inception of the field of forensic anthropology, practitioners have been developing methods to perform the aforementioned tasks. It is crucial that these methods be consistent, repeatedly tested, validated, and improved for multiple reasons. Firstly, to conform to Daubert (1993) standards, and additionally, to make sure that they are accurate and applicable to modern forensic cases. The present study was performed to validate the efficacy of the method for estimating sex from the os pubis originally proposed in Klales et al. (2012), as well as the efficacy of the “transition analysis” method for estimating age, originally outlined in Boldsen et al. (2002). Considering the recent popularity of using these methods to create a biological profile for forensic cases, it is necessary to develop error rates on a large, modern, American autopsy sample. These two methods are not only being readily utilized, but are additionally being taught to students in training. The utilization of these models involves a “logistic regression model” created by Klales et. al (2012) to process ordinal scores, and the Bayesian statistics software program “ADBOU” that was created for processing data collected using the method in Boldsen et. al (2002). These statistical systems which produced age estimates are relatively young compared to methods developed for the same purpose. The new generation of forensic anthropologists is fully responsible for objectively critiquing and validating these methods that are being disseminated by their professors and senior practitioners. The goal of the present study is to do just that. A skeletal reference sample of 630 pubic bones, all removed from modern autopsy cases and housed at the Maricopa County Forensic Science Center in Phoenix, Arizona, was utilized for data collection in the present study. Each pubic bone was assessed and scored according to the exact instructions outlined in the materials for each method, which was the Klales et al. (2012) paper for sex estimation, and the UTK Data Collection Procedures for Forensic Skeletal Material 2.0 for age estimation (Langley et al. 2016). Additionally, the observers recorded their “gestalt” estimates for sex using the Phenice (1969) system, as well as Brooks and Suchey (1990) and Hartnett (2010a) phases for each pubis. Demographic information labels were hidden, and the collection demographic information was not viewed until the completion of data collection. The null hypothesis in the present study is that both methods (the Klales et al. method (2012) and “transition analysis” method (Boldsen et al. 2002) will perform as well as they did in the original studies. The alternate hypothesis is that they do not result in the same accuracy rates reported in the original studies. Statistical analysis of the data indicates that there is sufficient evidence to reject the null hypothesis as it applies to the Klales et al. (2012) method. The classification accuracies achieved applying the logistic regression equation to the sample of pubic bones was found to be significantly lower than reported in the original study (86.2%), averaging around 70% between observers. The level of both intraobserver and interobserver agreement was only moderate for this method. It was also found that asymmetry occurred in some individuals, producing differing estimates of sex when the left and right pubes were scored separately. When utilizing the Boldsen et al. (2012) method and the ADBOU software package on only pubic symphyseal components to estimate age, the method was found to perform reasonably well. The majority (about 82%) of individuals had actual ages at death that fell within the predicted range produced by the statistical analysis. The majority of the symphyseal component scores showed moderate to good levels of interobserver agreement, and the estimated maximum likelihood (point estimate) of age at death predicted by the software package correlated moderately well with the actual age of death of the individual. These methods did not perform as well as reported in the original studies, and they should be further validated and recalibrated to improve their accuracy and reliability.

Forensic anthropologists increasingly use chemical isotope analysis in the investigation of unidentified human remains, as biochemical georeferencing continually improves with the development of modern reference data of known origins. Isotope variations in trace elements such as strontium (Sr) and lead (Pb) in human teeth are some of the most useful indicators of past domicile in archaeological research and thus have high potential for modern, forensic applications. In this study, high-precision lead isotope analysis was conducted on 63 modern human teeth, which were previously analyzed for strontium isotopes. The results present new lead isotope data for the following countries: United States (n=34), Colombia (n=9), Haiti (n=5), Cape Verde (n=3), Morocco (n=2), El Salvador (n=2), Guatemala (n=2), Honduras (n=2), Jamaica (n=1), Dominican Republic (n=1), Albania (n=1), and United Kingdom (n=1). In addition, the lead and strontium isotope data of 23 modern human teeth from individuals born in Holland, eight teeth from individuals born in Bulgaria, and 26 teeth from individuals born in the U.S. are extracted from the literature to supplement the data analysis. Exploratory data analysis, nonparametric Kruskal-Wallis tests, and one-way analysis of variance (Scheffe post hoc) are conducted using IBM SPSS® Statistics 24 to test for regional variation. Several trends are observed in the lead isotope data that may be relevant to modern forensic contexts involving unidentified human remains: Individuals from the northeast U.S. have relatively distinct 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb ratios when compared to individuals from the rest of the U.S. European and American individuals can be easily distinguished from each other using 208Pb/204Pb, 207Pb/204Pb, and 206Pb/204Pb ratios. Central American individuals have significantly lower 87Sr/86Sr ratios than North American individuals, and these groups can be easily distinguished using lead versus strontium scatterplots. Colombian individuals have significantly lower 87Sr/86Sr ratios than North American individuals, and these groups can be easily distinguished using lead versus strontium scatterplots. Caribbean individuals have significantly lower 87Sr/86Sr isotope ratios than individuals from the northeast U.S., and these groups can be easily distinguished using lead versus strontium scatterplots.

<p> This study investigates how heterosexual young people understand and manage risks related to meeting sexual partners online in the United States. The purpose of this study is to help inform the development of culturally-appropriate sexual risk communication and health promotion messages for young people by linking public health knowledge of adolescent sexual health and eHealth with anthropological theories of risk. With qualitative data from two rounds of semi-structured interviews and two group interviews with university students in central Florida, this study shows how young people experience and prioritize more social-emotional risks in meeting online-to-offline sexual partners compared to physical risks. The prominence of these social-emotional risks implies the need for more health promotion messages that incorporate both physical and social-emotional health risk communication.</p>