Drought-Induced Civil Conflict Among the Ancient Maya.

The influence of climate change on civil conflict and societal instability in the premodern world is a subject of much debate, in part because of the limited temporal or disciplinary scope of case studies. We present a transdisciplinary case study that combines archeological, historical, and paleoclimate datasets to explore the dynamic, shifting relationships among climate change, civil conflict, and political collapse at Mayapan, the largest Postclassic Maya capital of the Yucatán Peninsula in the thirteenth and fourteenth centuries CE. Multiple data sources indicate that civil conflict increased significantly and generalized linear modeling correlates strife in the city with drought conditions between 1400 and 1450 cal. CE. We argue that prolonged drought escalated rival factional tensions, but subsequent adaptations reveal regional-scale resiliency, ensuring that Maya political and economic structures endured until European contact in the early sixteenth century CE.

Evaluating the utility of time-lapse imaging in the estimation of post-mortem interval: An Australian case study.

Estimating post-mortem interval is an important aspect in forensic investigations. The aim of this study was to investigate if time-lapse imaging can be used to improve estimates of post-mortem interval using Megyesi et al.'s [1] method for a human donor decomposing in an Australian environment. To achieve this, time-lapse images were taken every 30 min over a 6-month period. The Megyesi et al. [1] total body score (TBS) system was used to quantify the level of decomposition of the donor for each image. Linear regression was performed to determine if observing decomposition more than once a day leads to increased accuracy in predicting PMI (post-mortem interval). Decomposition initially progressed quickly and then plateaued at 1004 hours PMI, with a TBS of 24. Individual timestamps were created from the time-lapse images taken each day at 08:00 hrs, 11:00 hrs, 14:00 hrs, 15:00 hrs, and 17:00 hrs. All timestamps produced R2 values > 0.80, indicating that the Megyesi et al. [1] method accurately predicts PMI for this donor. The 08:00 hrs timestamp had the highest value R2 = 0.886, whilst the combined timestamp (which included the scores from all five images for each 24-hour period) R2 = 0.823 was the lowest. This study supports the validity of Megyesi et al.'s [1] TBS model to estimate PMI. Two other interesting findings were that the results suggest that scoring TBS multiple times per day does not improve estimates of PMI, however scoring TBS at daybreak produces more accurate results than scoring TBS later in the day. This may be an important consideration in forensic scenarios.

Bioarchaeological investigation of ancient Maya violence and warfare in inland Northwest Yucatan, Mexico.

This study investigates evidence of changes and continuities in ancient Maya violence and warfare in inland northwest Yucatan, Mexico from the Middle Preclassic (600-300 BC) to the Postclassic (AD 1050-1542) through bioarchaeological analysis of cranial and projectile trauma. It is hypothesized that the frequency of violence increases before the Classic Maya collapse and remains high during the Postclassic period. It is also hypothesized that the flat, open terrain was conducive to warfare and resulted in higher trauma frequencies than in other parts of the Maya area. Results show that the frequency of cranial trauma decreases before the Classic collapse and increases in the Postclassic, partially matching the expected chronological trends. The frequency of cranial trauma does not differ significantly from other Maya regions but the pattern does: for all periods, males have more healed injuries than females and they are concentrated on the left side of the anterior of the skull. Some injuries appear to be from small points hafted in wooden clubs. In addition, projectile trauma is evident in a scapula with an embedded arrowhead tip, the first such case reported in a Maya skeleton. Overall, these results suggest greater reliance on open combat and less on raids in this region compared with other parts of the Maya area, possibly due to the flat, open terrain, though the identification of perimortem trauma in both women and men indicates surprise raids on settlements were also practiced.

Attitudes of Australian chiropractic students toward whole body donation: a cross-sectional study.

Cadavers play an important role in anatomy education. In Australia, bodies for anatomy education are acquired only through donations. To gain insight into educational dynamics in an anatomy laboratory as well as to facilitate body donation programs and thanksgiving ceremonies, it is important to understand students' attitudes toward body donation. In this cross-sectional study, the attitudes of Macquarie University's first, second, and fifth year chiropractic students toward body donation were investigated. Macquarie University chiropractic students have a four semester long anatomy program, which includes cadaver-based instruction on prosected specimens. A questionnaire was used to record respondents' demographics and attitudes toward body donation: personal, by a relative, and by a stranger. It was found that ethnicity and religion affect attitudes toward body donation, with Australian students being more willing to donate a stranger's body and atheists and agnostics being more willing to donate in general. Furthermore, willingness to donate one's own or a family member's body decreases as year of study increases, suggesting a possible negative impact of exposure to cadavers in the anatomy laboratory. This was only true, however, after controlling for age. Thus, the impact of viewing and handling prosected specimens, which is the norm in anatomy classes in Australia, may not be as strong as dissecting cadavers. It is suggested that anatomists and educators prepare students for cadaver-based instruction as well as exhibit sensitivity to cultural differences in how students approach working with cadavers, when informing different communities about body donation programs and in devising thanksgiving ceremonies.