Ross Ann H, Hale Amanda R
Department of Biological Sciences, North Carolina State University, Raleigh, NCUSA.
Forensic Sci Res. 2018 Sep 20;3(4):294-303. doi: 10.1080/20961790.2018.1489362. eCollection 2018.
There is currently a dearth of research investigating the progression and rate of decomposition for juvenile remains. It is thought that juveniles and infants decompose at an increased rate relative to adults due simply to body mass and that skeletal preservation is commonly dependent on intrinsic levels of bone mineral density (BMD). This study investigates the environmental variables important in driving juvenile decomposition as well as examining if currently accepted methodology for quantifying adult decomposition can be applied to juvenile remains. Furthermore, histological analysis is undertaken to test the Histological Index (HI) as a semi-quantitative indicator of decomposition. Thirty-five ranging between 1.8 and 22.7 kg were deposited to simulate body mass of human infant and juvenile remains. Pigs were deposited every season over two years in the southeastern US with five depositional types: bagged, blanket wrapped, and surface control foetal remains, surface, and buried juvenile remains. Remains were scored quantitatively throughout soft tissue decomposition. Following study completion and skeletonization, a femur was selected from each set of remains for histological analysis. Thick sections were assessed under standard brightfield light and scored using Oxford Histological Index (OHI). Results indicate that seasonal variation is an important factor to consider even when using a standardized time variable such as accumulated degree days (ADD), particularly variation in soil moisture. Soil moisture was a consistent significant variable in the mixed effects model. The pattern of decomposition using total body score (TBS) was similar to that observed by others prior to log transformation with a rapid incline early in decomposition with levelling off. The correlation between time in days, ADD, and TBS was not as strong as those previously reported ( = 0.317 and 0.499, respectively) suggesting that TBS as it is currently formulated cannot be directly applied to juvenile remains. Finally, the OHI model performed moderately well, but was variable even within seasons across multiple years.
目前，对于青少年遗体分解的过程和速率的研究十分匮乏。人们认为，青少年和婴儿相对于成年人的分解速率更快，这仅仅是由于体重原因，而且骨骼保存通常取决于骨矿物质密度（BMD）的内在水平。本研究调查了驱动青少年遗体分解的重要环境变量，并检验目前用于量化成人遗体分解的方法是否可应用于青少年遗体。此外，还进行了组织学分析，以测试组织学指数（HI）作为分解的半定量指标。放置了35头体重在1.8至22.7千克之间的猪，以模拟人类婴儿和青少年遗体的体重。在美国东南部，每季度放置猪，持续两年，共有五种放置类型：袋装、用毯子包裹以及表面控制的胎儿遗体、表面放置和掩埋的青少年遗体。在软组织分解过程中对遗体进行了定量评分。研究完成且遗体骨骼化后，从每组遗体中选取一根股骨进行组织学分析。在标准明场光下评估厚切片，并使用牛津组织学指数（OHI）进行评分。结果表明，即使使用诸如累积度日（ADD）这样的标准化时间变量，季节变化也是一个需要考虑的重要因素，尤其是土壤湿度的变化。在混合效应模型中，土壤湿度是一个始终显著的变量。使用总体评分（TBS）的分解模式与其他人在对数转换之前观察到的模式相似，即在分解早期迅速上升，随后趋于平稳。天数、ADD和TBS之间的相关性不如先前报道的强（分别为r = 0.317和0.499），这表明目前制定的TBS不能直接应用于青少年遗体。最后，OHI模型表现中等，但即使在多年的不同季节内也存在差异。
