A Bayesian approach to estimate skeletal age-at-death utilizing dental wear

In the forensic context, teeth are often recovered in mass disasters, armed conflicts, and mass graves associated with human rights violations. Therefore, for victim identification, techniques utilizing the dentition to estimate the first parameters of identity (e.g., age) can be critical. This analysis was undertaken to apply a Bayesian statistical method, transition analysis, based on the Gompertz-Makeham (GM) hazard model, to estimate individual ages-at-death for Balkan populations utilizing dental wear. Dental wear phases were scored following Smith's eight-phase ordinal scoring method and chart. To estimate age, probability density functions for the posterior distributions of age for each tooth phase are calculated. Transition analysis was utilized to generate a mean age-of-transition from one dental wear phase to the next. The age estimates are based on the calculated age distribution from the GM hazard analysis and the ages-of-transition. To estimate the age-at-death for an individual, the highest posterior density region for each phase is calculated. By using a Bayesian statistical approach to estimate age, the population's age distribution is taken into account. Therefore, the age estimates are reliable for the Balkan populations, regardless of population or sex differences. The results showed that a vast amount of interpersonal variation in dental wear exists within the current sample and that this method may be most useful for classifying unknown individuals into broad age cohorts rather than small age ranges.     

Analysis of age-at-death estimation through the use of pubic symphyseal data

The question of whether age parameters derived from an American population will reliably estimate age-at-death for East European skeletal populations is important since the ability to accurately estimate an individual's age-at-death hinges on what standard is used. A reference sample of identified individuals with known ages-at-death from the regions of the Former Yugoslavia (n = 861) is used to determine the age structure of victims and serves as the prior in the Bayesian analysis. Pubic symphyseal data in the manners of Todd (Am J Phys Anthropol, 3 [1920], 285; Am J Phys Anthropol, 4 [1921], 1) and Suchey-Brooks (Am J Phys Anthropol, 80 [1986], 167) were collected for n = 296 Balkan males and females and for n = 2078 American males and females. An analysis of deviance is calculated using an improvement chi-square to test for population variation in the aging processes of American and East European populations using proportional odds probit regression. When males and females are treated separately, there is a significant association among females and the population (df = 1, chi-square likelihood ratio = 15.071, p = 0.001). New age estimates for Balkan populations are provided and are based on the calculated age distribution from the Gompertz-Makeham hazard analysis and the ages-of-transition. To estimate the age-at-death for an individual, the highest posterior density regions for each symphyseal phase are provided.     

退休政策的经济学分析及调整

退休政策通过影响劳动力的投入和养老负担对社会产出和就业人口、退休人口的福利水平产生影响，因此要对退休政策进行调整须进行较为充分的经济论证。研究对单人经济的退休年龄分析显示：存在一个基于个人一生效用最大化的“最佳”退休年龄，可合理平衡一生总产出和退休后的休闲。同理，一个多人经济社会也存在一个平均的“最佳”退休年龄。研究的结论如下：现有的退休年龄政策背景下，中国将面临日益沉重的养老负担，说明中国的退休年龄政策亟须调整；延迟退休年龄至少在长期对就业无负面影响，且可增加GDP:将暂时多余的社保基金用于金融投资无助于社会养老负担的缓解，养老金空账运行并无问题。为完善中国的退休政策，研究提出适时延长退休年龄、提高养老金标准和降低养老保险费率、对职工上缴的养老保险实施记账等建议。     

人皮肤组织刺、切创后IL-8表达的免疫组织化学研究

为探讨人皮肤刺、切创后白细胞介素 8(interleukin 8,IL 8)在推断皮肤损伤时间中的应用价值 ,本研究应用免疫组化技术对 5 2例不同损伤时间人体皮肤刺、切创组织中IL 8的表达进行了研究。伤后 4h的损伤皮肤组织中可见部分的多核粒细胞表达IL 8。伤后 12～ 2 4h ,大部分浸润的多核粒细胞及部分单核细胞为IL 8阳性。随伤后时间延长 ,IL 8阳性细胞以单核及成纤维细胞为主。伤后 4～ 6h的皮肤中 ,IL 8阳性细胞比率较低 ,为 16 0±10 1%。伤后 1～ 4d达高峰 ,为 5 9 6± 8 7%。其后逐渐减少。本研究结果表明 ,IL 8的表达可用于皮肤刺、切创后损伤时间的推断。     

PDGF-β,PDGFR-β,TGF-β1,bFGF在创伤愈合过程中的表达变化与损伤时间关系的研究

目的研究细胞因子在创伤及修复过程中的表达变化与损伤时间 ( 伤口年龄 ) 的关系 . 方法用免疫组织化学技术和图像分析技术 , 对实验大鼠不同损伤时间的生前伤 ( 0.5～ 168h am) 及死后伤 ( 0.5～ 6h pm) 皮肤创缘组织中细胞因子和受体的表达变化进行了研究 . 结果在生前伤 , PDGF- β , PDGFR- β , TGF- β 1, bFGF等细胞因子在上皮细胞的表达于损伤后 0.5h am 即开始增强 , 其中以 24～ 96h am反应最强 . TGF- β 1, bFGF 以及 PDGF- β除了在上皮细胞的表达外 , 还大量出现在肉芽组织的巨噬细胞和成纤维细胞内 , 亦以 24～ 96h am 最明显 , 而死后损伤组上述因子仅在 0.5～ 3h以内有弱表达 , 3h后则均无任何表达 . 结论 PDGF- β , PDGFR- β , TGF- β 1, bFGF在创伤愈合过程中的变化及特点与损伤时间的关系可作为推断损伤时间的免疫病理学标志 .     

青少年骨关节X线片的骨龄研究

通过对11～16周岁女性及13～20周岁男性青少年左侧肩、肘、腕、髋、膝、踝关节拍摄X线片,进行了青少年的骨龄研究.根据骨骼生长发育的特点,提出了各大关节X线片判定骨龄的观察指标及分级标准,并使用SPSS软件包进行数据处理,建立了青少年利用6大关节骨骺愈合程度判定女性是否已满14周岁、男性是否已满16周岁或18周岁的判别分析方程.     

白竭散治疗肛周脓肿合并糖尿病术后创面22例

目的 观察白竭散治疗肛周脓肿合并糖尿病术后创面的疗效。方法 将44例肛周脓肿合并糖尿病的患者随机分为治疗组和对照组,每组各22例。两组病例常规给予降糖和抗感染治疗,治疗组术后创面用白竭散换药,对照组予凡士林纱条换药。分别观察两组病例术后７、14 d创面疼痛程度、渗液情况、创面愈合率、成纤维细胞数量。结果 两组病例术后７ d创面疼痛程度、渗液情况比较,差异有统计学意义（P＜0.05）,创面愈合率、成纤维细胞数量比较,差异无统计学意义（P＞0.05）;术后14 d创面疼痛程度、渗液情况比较,差异无统计学意义（P＞0.05）,创面愈合率、成纤维细胞数量比较,差异具有统计学意义（P＜0.05）。结论 白竭散治疗肛周脓肿合并糖尿病的术后创面,早期能减轻疼痛、减少渗液,后期有促进创面愈合的作用。     

信息化战争中我军舆论战战法的构建

信息化战争按时间可划分为扼制战争阶段、战前准备阶段、战争实施阶段、战争结束阶段。科学构建信息化战争中我军舆论战战法,需要将信息化战争各阶段舆论战的“重心”细化为各种具体任务,针对每个任务提出相关战法。     

IL-33在小鼠皮肤创伤后损伤时间推断中的作用

目的通过观察白细胞介素-33(interleukin-33,IL-33)在皮肤创伤后的时序性变化规律,探讨IL-33在法医学实践中用于损伤时间推断的应用价值。方法利用直径为5mm的圆形锉刀在小鼠背部建造皮肤损伤模型,于伤后1h、3h、6h、12h、1d、3d、5d、7d、10d取损伤处组织,对照组在与创伤组小鼠相同部位取同等大小的皮肤样本。采用苏木精-伊红(hematoxylin-eosin,HE)染色法观察皮肤创伤后愈合过程中的形态学变化,通过Western印迹法、免疫组织化学染色和双重免疫荧光染色法检测皮肤创伤样本IL-33的表达变化。结果Western印迹法结果显示,伤后3h,IL-33蛋白表达稍有下降,6h后IL-33蛋白表达逐渐增加,于伤后3d达峰值,随后逐渐减少。免疫组织化学染色结果显示,在对照组皮肤的表皮、毛囊、皮脂腺及真皮中固有细胞有少量IL-33阳性表达,伤后3h,IL-33阳性细胞率开始增加,伤后3d达到峰值,随后逐渐减少。双重免疫荧光染色结果显示,伤后1~3d,IL-33阳性表达细胞主要为巨噬细胞,伤后5~7d,IL-33阳性表达细胞主要为肌成纤维细胞。HE染色结果显示该皮肤损伤模型创口愈合过程符合炎症的病理学发展规律。结论IL-33有望成为法医学推断皮肤损伤时间的参考指标。     

Third molar development in a London population of White British and Black British or other Black ethnicity

Population differences in dental development between Black and White ethnic groups have been debated but not previously studied in the UK. Using inappropriate data for dental age estimation (DAE) could lead to erroneous results and injustice. Data were collected from dental panoramic radiographs of 5590 subjects aged 6–24 years in a teaching hospital archive. Demirjian stages were determined for left-sided teeth and third molars and data collected regarding hypodontia and third molar agenesis. Third molar development in self-assigned Black British, including other self-assigned Black ethnicity, was compared with that of self-assigned White British subjects. Data were compared for males and females in the two ethnic groups using T-tests for Demirjian Stages A–G of third molar development and Mann-Whitney tests for Stage H once a cut-off age at the maximum age for Stage G had been imposed. Third molar development occurred earlier in subjects of Black ancestry compared to those of White ancestry. While both ethnic groups showed large age ranges for every third molar stage, in female subjects these generally occurred at least 1.5 years earlier, and in males at least one year earlier. Hypodontia and third molar agenesis were more prevalent in White British, but the ethnic difference in third molar development persisted in subjects with complete dentitions. This is a large study that confirms ethnic differences in a London population, emphasises the difficulties of establishing the 18-year-old threshold using DAE, and confirms the risk of overestimating the age of individuals of Black ethnicity using White ethnic reference data.