The taphonomic impact of scavenger guilds in peri-urban and rural regions of central and southern Alberta. Part I – Identification of forensically relevant vertebrate scavengers

As a body decomposes in an outdoor environment, numerous taphonomic agents can act on the process of human decomposition. It is important to understand the impact of these agents as they can vary the rate of soft and hard tissue loss which may alter postmortem interval estimations. One taphonomic factor which has not been extensively investigated in many regions of the world, including Canada, are vertebrate scavengers. The current study aimed to identify scavenger guilds in the peri-urban and rural regions of two major cities in Alberta (Calgary and Edmonton) where human remains are frequently located. Vertebrate scavenger activity was recorded continuously using cellular and noncellular trail cameras. Images were analyzed to determine how the scavenging profiles (i.e., scavenger species, arrival time, and feeding behavior) impacted the loss of soft and hard tissue. We identified a range of mammalian and avian scavengers and found that coyote and black-billed magpie were the predominant scavengers recorded at the Edmonton peri-urban and rural sites, and the Calgary peri-urban sites. In contrast, when a site was within bear territory such as the Calgary rural sites, black and grizzly bears were the predominant scavengers. At all sites, the large mammalian scavengers were responsible for most soft tissue loss and subsequent hard tissue dispersal. None of the scavengers demonstrated a clear preference for open versus closed sites. This taphonomic information is important to consider when searching for human remains at these locations or in other North American regions with comparable scavenger guilds.     

Facial Soft Tissue Thickness Database for Craniofacial Reconstruction in Korean Adults

Abstract: One hundred Korean adults (50 men, 50 women) were scanned in the upright position using a cone‐beam CT (CBCT) scanner. The soft tissue (ST) thicknesses were measured at 31 landmarks, 10 midline and 21 bilateral landmark sites, and the means and standard deviations were obtained for male and female subjects. While 18 of 31 landmarks showed sex differences, the majority showed higher values for male subjects with the exception of a few landmark sites corresponding to the zygoma area, which showed smaller values in men than in women. The mandibular area showed greater differences between the right and left sides. Overall, the ST thickness measurements obtained in this study can be used as a database for the forensic craniofacial reconstruction of Korean adult faces.     

Gunshot residues on dry bone after decomposition-a pilot study

Abstract: Very little literature exists concerning radiochemical and microscopic analyses of gunshot wounds in decomposed material, and even less concerning skeletonized samples; the most advanced technologies may provide useful indications for the diagnosis of suspect lesions, especially if gunshot wounds are no longer recognizable. However, we know very little of the survival of gunshot residues (GSR) in skeletonized samples. This study examined nine gunshot wounds produced on pig heads which then underwent skeletonization for 4 years, and four gunshot entries on human heads from judicial cases which were then macerated to the bone in water; the samples underwent scanning electron microscopy coupled with energy dispersive X‐ray (SEM‐EDX) analysis. Positive results for GSR were observed only in four of the nine animal samples and in all four human samples. Among the human samples, two lesions showed Pb and Sb, one lesion only Pb, and one Pb, Sb, and Ba. This pilot study showed the survival of GSR in skeletal material and therefore the crucial importance of SEM‐EDX analyses on skeletonized material. Further studies are needed in order to ascertain the role of environmental modifications of GSR.     

组织RNA检测用于死亡时间推断的研究进展

近几年来利用RNA的降解程度来推断死亡时间已逐渐成为法医学研究热点.本文复习相关研究文献,对大鼠不同组织(脑组织、心脏组织、肝脏组织和肾组织等)中RNA在推断死亡时间的具体应用方法做出总结,归纳出不同组织中的各类RNA在推断死亡时间方面的适用范围,以及对此种方法在推断死亡时间的过程中产生的问题及可行性的解决方法.     

硬组织中D1S80位点基因型分析

用PCR技术分析硬组织中DIS80位点基因型及其DNA含量。当DNA部分降解时．此法仍然可行。证实了在同一个体，骨-血液及牙齿-血液DIS80位点的AmP－FLP的一致性。可应用于微量硬组织个人识别及骨化遗骸身源鉴定。     

甲醛固定组织中DNA提取与扩增技术的初步研究

目的：探索从甲醛固定组织中提取并扩增DNA的方法。方法：采用高pH缓冲液,结合有机溶剂法抽提DNA,选择扩增片段较短的DQa位点作为检测位点。结果：甲醛固定组织中的DNA降解程度随浸泡时间的延长而加重,但浸泡1、5、10个月的3份心脏组织均获得了240bp的扩增产物。     

四川汉族青少年面部中线软组织厚度的数字X线测量

目的测量四川汉族青少年(8～20岁)人群面部中线软组织厚度,探讨其生长发育变化规律,为法医人类学的面部重建提供的基础数据。方法选取974例(男496,女478)头颅侧位数字X线片,分13个年龄段(8～20岁),选择面部10个标志点的软组织厚度测量,并进行描述性统计学分析。结果四川汉族青少年人群面部10个标志点的中线软组织平均厚度,在青少年阶段大多数测量标志点随年龄增长而增厚;男女性面部中线软组织厚度统计学分析存在性别差异(P<0.05),在15岁之后差异增大,且LLI点显著差异性在9～20岁之间均存在(P<0.01)。结论四川汉族青少年面部中线软组织厚度有随年龄增长而增厚的趋势,男女面部软组织厚度存在性别差异。     

Allelic alterations of STRs in archival paraffin embedded tissue as DNA source for paternity testing

Owing to a wrong name registered on ID card, the identity of a businessman who had been dead and cremated was suspected, which led his son failed to get legacy. In order to prove the parenthood, the son submitted the gastric cancer tissues surgically removed and embedded in a paraffin block as DNA source for paternity test. After extracting DNA with QIAamp DNA Blood Mini Kit, the 16 STR loci was amplified by two commercial kits of Sinofiler^® (ABI)and Powerplex 16 (Promega), respectively. Both of the STR profiles were similarly showing allelic imbalance pattern at some loci and an additional allele at locus D18S51. The cancerous tissues and adjacent normal tissues were then partitioned off from each other by microscopic analysis of H.E. stained sections and followed by DNA extracting and STR typing, respectively. The allelic alteration could not be found in normal tissues whereas it did in cancerous tissues whose STR profile showed complete loss of one allele (LOH) at loci D13S317 (allele 11 was lost), partial loss of one allele (pLOH) at loci D21S11, D7S820, D19S433, vWA, D12S391 and Amelogein and occurrence of an additional allele (allele 20 was added) at locus D18S51. The results demonstrated that the Paraffin Embedded cancer Tissue used as DNA source for forensic identification is possibly questionable because of their microsatellite instability (MSI) or loss of heterozygosity. It was suggested to partition the normal tissues from the cancer tissues by microscopic evaluation first and then analyzing DNA separately. Comparing the STRs profile of normal tissue with the son's blood sample, the final conclusion was acquired that the donor of the paraffin embedded tissues is the biological father of the son.     

人体组织两种简易保存法DNA抽提效果的比较研究

比较研究人体不同组织在不同保存条件下DNA抽提效果。取冷冻保存和50％乙醇固定保存的各种组织，用有机溶剂抽提法提取DNA。用50％乙醇固定保存的人体不同组织在校长时期内仍可获得与新鲜冷冻组织相近的DNA抽提效果，经卡方检验二者无明显差异（X2≤0．21，P≥0．995）。乙醇保存法简便易行，DNA产量高，效果好，适用于各种特殊情况下的组织保存。     

多发性软组织挫伤后对肺及其他脏器的影响

目的观察多发性软组织挫伤后短时间内死亡案例的脏器病理学改变。方法应用常规组织学及免疫组织化学染色技术进行光学显微镜检查。结果光镜检查见肺组织毛细血管扩张充血，白细胞集聚，肺组织散在片状出血、灶状坏死及透明膜形成；心脏间质血管扩张充血，点灶状纤维溶解；脑组织充血水肿，肝脾充血。免疫组化发现肺泡腔及部分血管内纤维蛋白染色阳性，部分脾脏血管内及肾髓质集合管中肌红蛋白染色阳性。结论本研究结果提示多发性软组织挫伤后短时间内死亡的死因为成人呼吸窘迫综合征（ARDS）合并多脏器功能衰竭。