Mitochondrial DNA amplification success rate as a function of hair morphology

This study examines the amplification success rate of mitochondrial DNA from human head hair with respect to their potential for forensic application. Mitochondrial DNA was isolated using a Chelex-based extraction method and amplified using the LINEAR ARRAY duplex PCR system. The particular focus of this study was to characterize the morphological features of human head hair in order to further the understanding of the factors that influence amplification success rate in hair tissue using the LINEAR ARRAY duplex PCR system. 2554 head hairs from 132 individuals representing four population groups were amplified. The hair samples were characterized as follows: 1251 were identified microscopically as telogen hairs and 1303 were classified as hairs without roots (removed before extraction). Amplification success was assessed as a function of several independent variables: morphological characteristics; telogen root versus no root; donor age; scalp origin; use of cosmetic hair treatments; and race of the donor. The results show that a positive correlation exists between amplification success and the presence of a telogen root. Combining the amplification success with either the original or optimized protocol, telogen hairs result in an overall success rate of 77.5% compared with 65% for hairs with no roots. Controlling for telogen hairs, the findings indicate that the overall success rate is independent of cosmetic hair treatments; medulla structure; shaft length, diameter, and volume; and scalp origin. Conversely, the age of the donor, the race of the donor, and hair pigmentation all contribute to a variation in amplification success rate.     

Analysis of the Spectre of Urban Density From the Perspective of Compactness of Forms A Response to a New Urban Vulnerability

The concepts of ＂density＂ and ＂urban morphology＂ are today at the centre of debates on architecture and urban planning. The concept of＂density＂ provides a solution to the issue of urban sprawl and, consequently, offers a way of rethinking sustainable urban and rural development. The densification of urban centres makes it possible to reduce a vulnerability related to the excessive use of suburban areas. However, densification is not a ＂turnkey＂ solution. Numerous criteria relating to its use are poorly understood. As numerous contemporary experiences have demonstrated, urban densification exposes space systems to new, unknown forms of vulnerability. First, the concept of ＂vulnerability＂ will be defined, specifically that of urban vulnerability, as well as related concepts, such as those of risk, hazard, and challenges. Secondly, forms of vulnerability inherent in the over-densification paradigm are pinpointed： This will involve determining the specific hazards, challenges, and risks of this space system. Thirdly, the authors will demonstrate how the concept of ＂compactness＂ makes it possible to review at the different urban levels the densification processes of territories and urban areas. Finally, a tool for the optimisation of compact urban morphologies for use in countering the related hazards and risks will be proposed.     

An investigation into the relationship between edge counts and the variability of the refractive index of glass. Part I: Edge morphology

The effect of glass fragment morphology on the variability of refractive index values in five different glass objects was investigated. Data are presented that suggest that the variability of refractive index values is increased when fragment edge morphology becomes unsuitable for phase contrast microscopy.     

Identification of group affinity from cross-sectional contours of the human midfacial skeleton using digital morphometrics and 3D laser scanning technology

Identifying group affinity from human crania is a long-standing problem in forensic and physical anthropology. Many craniofacial differences used in forensic skeletal identification are difficult to quantify, although certain measurements of the midfacial skeleton have shown high predictive value for group classifications. This study presents a new method for analyzing midfacial shape variation between different geographic groups. Three-dimensional laser scan models of 90 crania from three populations were used to obtain cross-sectional midfacial contours defined by three standard craniometric landmarks. Elliptic Fourier transforms of the contours were used to extract Fourier coefficients for statistical analysis. After cross-validation, discriminant functions based on the Fourier coefficients provided an average of 86% correct classifications for crania from the three groups. The high rate of accuracy of this method indicates its usefulness for identifying group affinities among human skeletal remains and demonstrates the advantages of digital 3D model-based analysis in forensic research.     

Characterization of Mitochondrial DNA Sequence Heteroplasmy in Blood Tissue and Hair as a Function of Hair Morphology*,†,‡

Abstract: This study characterizes mitochondrial DNA (mtDNA) sequence heteroplasmy in blood tissue and hair as a function of hair morphology. Bloodstains (127 individuals) and head hairs (128 individuals) were typed using the mtDNA LINEAR ARRAY? assay. A total of 1589 hairs were interpreted: 1478 (93%) were homoplasmic and 111 (7%) exhibited heteroplasmy at one or more positions. Seventy‐one percent (82/116) of individuals were homoplasmic, whereas 29% (34/116) exhibited heteroplasmy in at least one hair. The results demonstrate intra‐ and inter‐tissue differences in heteroplasmy within individuals. Sequence heteroplasmy among hairs from each individual varied from 0 to 90%; the frequency does not differ significantly with population group, cosmetic treatment, age, gender, medulla morphology, region of the scalp, hair growth phase, or, when comparing living and deceased donors. However, the results support a correlation between heteroplasmy and hair pigmentation; typically, lighter‐pigmented hairs exhibit a higher incidence of sequence heteroplasmy compared to darker hairs.     

The development of visual and chemical methods for predicting the likelihood of obtaining a DNA profile from degraded bone samples

Gross morphology, histology and nitrogen content were examined in bone samples from individuals that had been buried for approximately 12 years in Kuwait and Iraq. The results indicate that the gross morphology and histology are useful indicators of DNA survival. Nitrogen content did not show a significant correlation with DNA preservation.     

Cerebral hypoxia and ischemia: the forensic point of view: a review

In cases with suspected brain anoxia/ischemia and hypoxia/hypoxemia a neuropathological investigation should give additional information to elucidate the cause of death and its pathophysiological mechanisms. Primary ischemic brain damage is associated with morphological and biochemical alterations. While acute ischemic neuronal injury reveals axon sparing and selective neuronal lesions due to the release of large quantities of glutamate, late neuronal death is associated with antiapoptotic growth factors, and decreased expression of microtubule-associated proteins and tubulin. On the morphological level ischemia can be detected by necrosis of neurons, proliferation of microglia, and astrocytes in vulnerable regions of the brain. In cases of permanent ischemia the so-called pale nervous cell injury is observed, in cases of partial perfusion the so-called dark nerve cell injury and apoptosis are detectable. In spite of the considerable advantages of recent research, presently there is no reliable qualitative marker to ascertain death due to acute hypoxic or ischemic events.     

对传统美学的修正、整合与超越——评郭昭第《审美形态学》

郭昭第《审美形态学》将现实美、感觉美和艺术美作为审美形态分别置于人类审美活动的前审美、审美和后审美三个阶段,并对其审美性质、类型特征、创造法则和基本范式进行了全面、深入和系统的阐述,成功修正、整合和超越了传统美学本质论、学科论和形态论乃至审美形态学理论构想,创造性地建构了真正具有全方位视野和完整体系的审美形态学理论。     

融合词形态与词义中的融合概念

英语融合词在形态和语义中均体现了融合概念。形态上，截短两个或三个源单词形态，通过音位或字形的融合点或面将截短的词形融合形成融合词。融合而成的形态中，显现了多语域、多层面词汇的融合概念和意义。     

Accuracy Rates of Sex Estimation by Forensic Anthropologists through Comparison with DNA Typing Results in Forensic Casework

A common task in forensic anthropology involves the estimation of the biological sex of a decedent by exploiting the sexual dimorphism between males and females. Estimation methods are often based on analysis of skeletal collections of known sex and most include a research‐based accuracy rate. However, the accuracy rates of sex estimation methods in actual forensic casework have rarely been studied. This article uses sex determinations based on DNA results from 360 forensic cases to develop accuracy rates for sex estimations conducted by forensic anthropologists. The overall rate of correct sex estimation from these cases is 94.7% with increasing accuracy rates as more skeletal material is available for analysis and as the education level and certification of the examiner increases. Nine of 19 incorrect assessments resulted from cases in which one skeletal element was available, suggesting that the use of an “undetermined” result may be more appropriate for these cases.