Heat-induced dimensional changes in bone and their consequences for forensic anthropology

An understanding of heat-induced transformation of hard tissue is vital before a full interpretation of burned human remains can be successfully achieved. Samples of modem sheep (n = 60) were analyzed resulting in 5440 data points. An experimental approach was undertaken that explored the bi-variable impact of heating temperature and duration of burning. Subsequent heat-induced bone changes included the progression of color from natural through to blue-white, the significant loss of weight, the reduction in mechanical strength, the development of distinct fracture patterns, alterations in the microscopic porosity, substantial alterations in crystalline structure and reduction and expansion in size. Collation and integration of this information demanded a revision of the four stages of heat-induced degradation of bone previously presented by Mayne Correia (1) and Thompson (2). The results demonstrate that heat-induced shrinkage is also accompanied by expansion and that both can be statistically significant. This suggests that anthropological techniques applied to burned bone will likely be detrimentally affected and accuracy will be reduced.     

“Sex change” in skeletal remains: Assessing how heat-induced changes interfere with sex estimation

The true impact of heat-induced changes in human bone regarding their sex estimation has not been comprehensively documented having a potentially negative impact on forensic anthropology. The objective of this paper was to evaluate how heat exposure affects sex estimation based on both morphological and metric features. The study focused in both low-to-medium intensity burns and high intensity burns. Selected sexually dimorphic features were analysed in 51 experimentally burnt skeletons from the 21st Century Identified Skeletal Collection. Bones were burnt to maximum temperatures between 450 °C and 1050 °C achieved after 75 to 257 min. Morphological methods tested in this study comprised the recommendations for hipbone features from Buikstra and Ubelaker (1994) and from Bruzek (2002). On the other hand, metric references tested here were the ones from Wasterlain (2000), Curate et al. (2016) and Gonçalves et al. (2013) focused on the humerus, femur, calcaneus and talus. Agreement was tested with Gwet’s AC1 test and was further assessed by calculating the relative amount of perfect agreements. Results demonstrated that heat-induced changes affected not only the scoring of morphological features burnt at high temperatures but also the scoring of features burnt at lower intensities. On the other hand, metric features were only considerably affected in high intensity burns, no major changes being documented for low-to-medium intensity burns. For low-to-medium intensity burns, the Bruzek and Curate et al. methods revealed a better agreement between the pre- and post-burning scores. For high intensity burns, better agreement was obtained by using the Bruzek (2002) and Gonçalves et al. (2013) methods. As expected, heat-induced warping, fracture and metric change had a major impact on the pre- and post-observations’ agreement. Contrary to what has been systematically assumed over the years, this impact is also quite substantial in bones burnt at low-to-medium burn intensities so caution is advised during the analysis of this kind of burnt skeletal material.     

Differentiation of traumatic and heat-induced dental tissue fractures via SEM analysis

Previous studies have examined the effects of heating on teeth; however, none have identified characteristics that allow analysts to differentiate traumatic from heat-induced fractures. This study examined our ability to discern notable differences in preincineration traumatic fractures and heat-induced fractures in postincineration dentition. Twelve anterior dental specimens were subjected to blunt force trauma while a second set were not. All 24 samples were then incinerated in a muffle furnace at a peak temperature (900°C) consistent with house fires. The specimens were subsequently examined with a scanning electron microscope to identify and compare heat-induced and traumatic fractures. The results obtained during examination yielded no differences between the features displayed by specimens that had been inflicted with preincineration trauma and those that did not. Unlike bone, distinguishing features for the differentiation of traumatic and heat-induced fractures could not be compiled.     

Time burnt away: The impact of heat-induced changes on skeletal age-at-death diagnostic features

This paper investigates the established notion that bone calcination has a major impact on age estimation while low-intensity burns have a mere negligible impact. Few systematic researches have been carried out so far about this topic so the true impact of heat-induced changes on diagnostic age features is mostly unknown.The agreement between pre-burning and post-burning observations of age features was investigated on 51 human skeletons (22 males and 29 females with ages-at-death ranging from 61 to 93 years old) subjected to experimental burns. These skeletons belong to the 21st Century Identified Skeletal Collection housed at the Laboratory of Forensic Anthropology of the Department of Life Sciences, University of Coimbra, Portugal. The Suchey-Brooks method based on the pubic symphysis and the method developed on the auricular surface by Buckberry and Chamberlain (2002) were scrutinized.The Suchey-Brooks method provided better agreement between pre- and post-burn observations than the method from Buckberry and Chamberlain (2002). However, it became clear that heat-induced changes affected both methods regardless of heat intensity since both calcined bones and bones burnt at lower intensities often showed less than perfect agreement. Therefore, this research demonstrates that the analysis of age-at-death can be impaired in burnt bones, even those not subjected to calcination, with clear impact for forensic and archaeological investigations.     

Thermally induced entrance wound-like defect of the skull

A case of death due to car fire is described where the carbonised skull of the cremated corpse showed an ovoid defect of the cranial bone. The question arose whether this formed fracture was caused by a gunshot. But the reconstruction of the cranial remains with detached parts of the tabula externa provided evidence that the suspicious defect was to be classified as an uncommon heat-induced post-mortem artefact.     

烧骨的研究现状与展望

本文根据国内外相关文献,对烧骨的宏观、微观形态学特点,烧骨形态特征与各影响因素之间的关系,热致骨折与损伤骨折、条件性骨折的鉴别等方面进行了综述,并对现有研究的局限之处进行了分析,提出改进方向。     

中国汉族成人肱骨近端CR片特征与年龄的相关性

目的探讨中国汉族成人肱骨近端CR片的特征随年龄变化的规律,以推断年龄。方法 210例中国汉族成人肩关节CR片,其中男性124例,年龄范围18~83周岁,女性86例,年龄范围18~60周岁,选取与年龄变化关系密切的肱骨骨髓腔高度、肱骨近端骨骺骨小梁变化、肱骨大结节内骨小梁变化、锁骨骨髓腔肩峰侧骨小梁变化4项指标,观察不同年龄各指标的变化进行统计分析。结果四项指标均是影响年龄变化的重要因素。肱骨近端骨骺骨小梁变化、锁骨骨髓腔肩峰侧骨小梁变化对年龄的预测影响较大,肱骨骨髓腔高度、肱骨大结节内骨小梁变化稍小。利用以上指标建立的回归方程能很好的反映成人肱骨的增龄性变化,预测骨龄较为准确。结论利用成人肱骨骨髓腔高度、肱骨近端骨骺骨小梁变化、肱骨大结节内骨小梁变化、锁骨骨髓腔肩峰侧骨小梁变化可推断年龄。     

Preliminary results of an investigation on postmortem variations in human skeletal mass of buried bones

Extreme fragmentation can complicate the inventory of human skeletal remains. In such cases, skeletal mass can provide information regarding skeleton completeness and the minimum number of individuals. For that purpose, several references for skeletal mass can be used to establish comparisons and draw inferences regarding those parameters. However, little is known about the feasibility of establishing comparisons between inherently different materials, as is the case of curated reference skeletal collections and human remains recovered from forensic and archaeological settings. The objective of this paper was to investigate the effect of inhumation, weather and heat exposure on the skeletal mass of two different bone types. This was investigated on a sample of 30 human bone fragments (14 trabecular bones and 16 compact bones) that was experimentally buried for two years after being submitted to one of four different heat treatments (left unburned; 500?°C; 900?°C; 1000?°C). Bones were exhumed periodically to assess time-related mass variation. Skeletal mass varied substantially, decreasing and increasing in accordance to the interchanging dry and wet seasons. However, trends were not the same for the two bone types and the four temperature thresholds. The reason for this appears to be related to water absorption and to the differential heat-induced changes in bone microporosity, volume, and composition. Our results suggest that mass comparisons against published references should be performed only after the skeletal remains have been preemptively dried from exogenous water.     

Detection of methamphetamine in mouse femurs exposed to high temperature

Bone samples are valuable for examining the cause of death and circumstance leading up to death when body fluids are not available for forensic toxicological analysis. Examined were heat-induced changes in methamphetamine and amphetamine concentrations in femurs removed from methamphetamine-injected mice to determine if the burned bones could be used for toxicology testing. The femurs were heated at 100°C, 300°C, or 500°C for 10 or 30 min. The tissue structure of the heated femurs was preserved at 100°C for 30 min but was destructed at higher temperatures. Methamphetamine and amphetamine were detected in femurs heated at 100°C for 10 min, 100°C for 30 min, and 300°C for 10 min (with methamphetamine and amphetamine concentrations ranging from 0.36 to 35 μg/g and 0.54 to 47 μg/g, respectively). Methamphetamine and amphetamine were detectable when heated above their decomposition temperature as a result of limited heat transfer do to protection provide by the femoral muscle. Thus, the bone could be a useful analytical sample in cases of burn-related deaths, where it is difficult to collect body fluids.     

Explaining the process of change taking place in legal rules and social norms: The cases of institutional economics and new institutional economics

This paper deals with the phenomenon of institutional change and has been conceived as an attempt to answer the following question: Can we retain theimage of institutional change contained in a theory when we replace a methodological foundation on which the theory was built by a different and alternative one? For an answer to be developed, special attention is paid to the contributions made by institutional economists (IE) and those made by transaction cost—new institutional economists (NIE). The question clearly shows that it is a paper on applied methodology rather than a survey on institutional change contributions. Because of that, its main purpose is not to increase our knowledge about the characteristics of real changes in legal rules and social norms, their causes, their processes, or their effects, though several examples are given of those institutionalist and new institutionalist contributions that analyze those changes. Our purpose is to investigate the way in which these two groups of economists approach the object of analysis already mentioned. Our conclusion will be that institutionalist and new institutionalist contributions are built on two different and mutually exclusive approaches because their respective methods of analysis (holism versus methodological individualism) are different and, above all, because they build their respective analyses on some concepts that are mutually exclusive (concepts showing power or nonvoluntary influences versus concepts showing voluntary transactions). Their analyses contain different and mutually exclusiveimages of the changes taking place in legal rules-formal institutions and social norms-informal institutions. Some comments about the limitations of the holist method of analysis are made in the paper.     

新形势下邪教的特点、趋势与防范策略

随着我们与邪教斗争的不断深入，邪教组织也根据形势的变化不断改变和调整其活动方式和策略．因此，新形势下邪教的活动出现了一些与以往有所不同的新特点。关注邪教活动的新特点，预测邪教活动发展趋势，研究与邪教斗争的方法与策略，是取得与邪教斗争的最后胜利的重要保证。     

Age-specific changes in bone tissue microstructure and potential for use for human identification

The possibility of using the data of quantitative microscopy of bone tissue for evaluation of age with the aim of personality identification is discussed. Computer histomorphological analysis of third rib, tibial lower epiphysis and diaphysis fragments from 564 male corpses of known age (0-90 years) was carried out. A complex of parameters most strongly correlating with age was detected: extension of active osteogenesis zone in the longitudinal section of a rib, thickness of layers of internal and external general diaphyseal laminae in the tibial bone, trabecular area in the tibial epiphyseal preparation, etc. Age-specific changes in bone tissue structures is characterized by a great variety and depends on the type and location of these structures. Bone tissue characteristics change irregularly and asynchronously, therefore their correlations with age are different in different age groups. A general biological interpretation of the results is offered.     

Rapid screening for the detection and differentiation of γ-hydroxybutyrate using ion chromatography

The analysis of gamma-hydroxybutyric acid (GHB) is problematic because it is hygroscopic, it lacks a good UV chromophore, and it undergoes heat-induced cyclization. This paper presents a new method utilizing ion-exchange chromatography (IC) with conductivity detection. The simple sample preparation, rapid analysis time, and inorganic anion detection capabilities are all advantages over the current methods. The detection of inorganic salts (formed during GHB synthesis) gives insight into the synthetic route utilized and can aid in drug seizure comparison. The developed method has a detection limit for GHB anions of 0.57 mg/L and chloride of 0.22 mg/L. A comparison of this technique with a current gas chromatography-mass spectrometry technique is presented, and a t-test found that the two methods' results are not statistically different at the 99.9% confidence level demonstrating the merits of this fast, simple, and informative IC method as a routine screening tool.     

Citrate Content of Bone as a Measure of Postmortem Interval: An External Validation Study

The postmortem interval (PMI) of skeletal remains is a crucial piece of information that can help establish the time dimension in criminal cases. Unfortunately, the accurate and reliable determination of PMI from bone continues to evade forensic investigators despite concerted efforts over the past decades to develop suitable qualitative and quantitative methods. A relatively new PMI method based on the analysis of citrate content of bone was developed by Schwarcz et al. The main objective of our research was to determine whether this work could be externally validated. Thirty‐one bone samples were obtained from the Forensic Anthropology Center, University of Tennessee, Knoxville, and the Onondaga County Medical Examiner's Office. Results from analyzing samples with PMI greater than 2 years suggest that the hypothetical relationship between the citrate content of bone and PMI is much weaker than reported. It was also observed that the average absolute error between the PMI value estimated using the equation proposed by Schwarcz et al. and the actual (“true”) PMI of the sample was negative indicating an underestimation in PMI. These findings are identical to those reported by Kanz et al. Despite these results this method may still serve as a technique to sort ancient from more recent skeletal cases, after further, similar validation studies have been conducted.     

论中药单方专利的创造性认定

随着中药单方专利侵权案件的日益增多,如何认定一个新中药单方是否构成对现有中药单方专利的侵权,显得尤为重要。按照我国《专利法》的规定,必须经过"三性"认定,而新中药单方"三性"认定的关键在于其与现有的中药单方专利相比是否具有创造性。因此,尽快制定中药单方专利的创造性认定标准迫在眉睫。当新中药单方与现有的中药单方专利相比使用了不同的药用部分、不同的剂型导致给药途径改变、不同的炮制方法导致归经改变、不同生产方法、工艺及增加或使用不同的引药、改变现有中药单方专利的混合物组分或组成混合物组分的剂量等时,如果其能在作用同一病症的不同类型、减少毒副作用、显著提高疗效、适应新的病症、作用新的部位等任何一方面有所突破,就应当认定该新中药单方对中药领域的普通技术人员来说具有"非显而易见性",有突出的实质性特点和显著的进步,具有创造性。     

Assessment of bone age based on morphometric study of the upper end of the humerus

Assessment of changes in the spongy bone structure of the upper end of the humerus is one of the common methods of age estimation. This method was devised many years ago (1894) and has never been verified in an objective numerical testing. We projected an objective morphometric method assessment of the upper end of the humerus. The study was carried out on humeri from cadavers of 88 men and 84 women. The surface area of atrophy of the spongy structure (medullary cavity) was calculated on the longitudinal section of the humerus. A new morphometric method was applied, which allowed numerical presentation of results. The results of the study show a lack of statistical correlation between atrophy of the spongy structure within the upper end of the humerus and the chronological age. Therefore, it can be concluded that the assessment of humerus structure should be omitted in the forensic medical age estimation.     

Crack Propagation in Teeth: A Comparison of Perimortem and Postmortem Behavior of Dental Materials and Cracks*

Abstract: This study presents a new method for understanding postmortem heat-induced crack propagation patterns in teeth. The results demonstrate that patterns of postmortem heat-induced crack propagation differ from perimortem and antemortem trauma-induced crack propagation patterns. Dental material of the postmortem tooth undergoes dehydration leading to a shrinking and more brittle dentin material and a weaker dentin-enamel junction. Dentin intertubule tensile stresses are amplified by the presence of the pulp cavity, and initiates crack propagation from the internal dentin, through the dentin-enamel junction and lastly the enamel. In contrast, in vivo perimortem and antemortem trauma-induced crack propagation initiates cracking from the external surface of the enamel toward the dentin-enamel junction where the majority of the energy of the crack is dissipated, eliminating the crack’s progress into the dentin. These unique patterns of crack propagation can be used to differentiate postmortem taphonomy-induced damage from antemortem and perimortem trauma in teeth.     

Quantitative Analysis of the Morphological Changes of the Pubic Symphyseal Face and the Auricular Surface and Implications for Age at Death Estimation

Age estimation methods are often based on the age‐related morphological changes of the auricular surface and the pubic bone. In this study, a mathematical approach to quantify these changes has been tested analyzing the curvature variation on 3D models from CT and laser scans. The sample consisted of the 24 Suchey–Brooks (SB) pubic bone casts, 19 auricular surfaces from the Buckberry and Chamberlain (BC) “recording kit” and 98 pelvic bones from the Terry Collection (Smithsonian Institution). Strong and moderate correlations between phases and curvature were found in SB casts (ρ 0.60–0.93) and BC “recording kit” (ρ 0.47–0.75), moderate and weak correlations in the Terry Collection bones (pubic bones: ρ 0.29–0.51, auricular surfaces: ρ 0.33–0.50) but associated with large individual variability and overlap of curvature values between adjacent decades. The new procedure, requiring no expert judgment from the operator, achieved similar correlations that can be found in the classic methods.     

重庆新型毒品违法犯罪的现状及对策

新型毒品的使用以青少年为主体，由主城向郊县、郊区蔓延，并已在吸食者中形成新型毒品亚文化圈。新型毒品在生产方面以当地生产为主，向周边乡镇转移。制毒组织以多人入股为主。制毒方式以高技术性、规模化生产为主。因此，在新型毒品的禁毒斗争中需要调整过去针对传统毒品形成的思路和方法，改变以往的禁毒宣传模式，制定、完善相关法规和标准，明确相关单位职责，协调各单位职能，调整人员配置，加大力度强化易制毒化学品的控管工作。