Ontogeny of femur subtrochanteric shape in Native Americans and American Blacks and Whites

Femur subtrochanteric size and shape can be used to differentiate between adult Native Americans and American Blacks and Whites, but little is known about when shape differences are established during growth and development. Ontological changes in subtrochanteric shape were examined using 74 Native American and 61 American Black/White subadult femora. At birth, the proximal femur diaphysis is relatively circular in both groups. Between birth and 5 years, the diaphysis becomes more mediolaterally broad, especially in Native Americans, due to differential growth between the mediolateral and anteroposterior planes. This change may be due to biomechanical stresses associated with developing a mature gait pattern. After the age of 5, growth occurs more equally in the two planes and shape does not change significantly. The adult shape of the proximal femur is established by c. 5 years of age and can be used to discriminate between Native American and American Black/White femora in older subadults.     

Biological sex variation in bone mineral density in the cranium and femur

Objectives

Sex and age trends in bone mineral density (BMD) play an important role in the estimation of age-at-death (AAD) of unidentified human remains. Current methodologies lack the ability to precisely estimate age in older individuals. In this study, BMD of the cranium and femur measured by DXA were examined to establish their applicability for age estimation in older adults. BMD as measured by DXA, is most commonly used clinically for prediction of osteoporotic fracture risk. We hypothesized that weight-bearing and non-weight-bearing bones, the femur and cranium, respectively, would provide valuable insights for aging.

Racial variation in the proximal and distal femur: heritability and forensic utility.

The femur has been studied successfully by physical anthropologists for many years. Such traits as femoral head diameter and bicondylar width have been examined extensively and are of great value to forensic anthropologists and other skeletal biologists in sex identification. A number of studies over the past decade by the author and his former students have shown marked racial differences in the shape of the proximal femur and in at least one trait of the distal femur--intercondylar notch height. Anterior-posterior (AP) diameter of the proximal femur is much greater among Whites and Blacks than among East Asians and American Indians. Blacks have slightly greater intercondylar notch height than Whites. Other features, such as torsion, also differ between the major geographic racial populations. Current analysis suggests that the East Polynesians fall close to the American Indians and East Asians in the degree of flatness of the proximal femur. One study has tracked the degree of change in flatness during individual development, and finds little change within major populations from the youngest to the oldest individuals. Temporal changes within populations are likewise minimal. Two studies have examined sex differences within populations, which are also found to be very slight. Racial differences, on the other hand, are quite significant, and individuals of admixed ancestry fall intermediate between the two parental populations. Such suggestions of high heritability in the shape of the proximal and distal femur make these traits very useful in assessing ancestry in forensic contexts.     

Zygomaticomaxillary suture shape analyzed with digital morphometrics: reassessing patterns of variation in American Indian and European populations

Typological classification of human zygomaticomaxillary suture (ZMS) shape is often used in forensic assessment of ancestry, following earlier studies reporting higher frequencies of "angled" sutures among American Indians and higher frequencies of "curved" sutures among Caucasians. In this paper we present a new method of digital morphometrics to quantify and compare ZMS shape in 60 American Indian and 60 European crania. Suture outlines were recorded as three-dimensional (3D) contours on digital models of adult male and female crania created with a portable 3D laser scanner. Each contour was represented by about four hundred point coordinates, which were transformed via Fourier analysis into amplitude coefficients suitable for use in linear discriminant analysis. Discriminant functions were created that accurately predicted group membership for 83% of the crania in the sample, after leave-one-out cross-validation. The results were compared with traditional typological classifications based on visual evaluation of ZMS shape, and the contour-based method was found to be more effective than the typological approach. However, the distribution of ZMS types within the two sample groups did not conform to previously reported patterns. This discrepancy indicates that ZMS shape may reflect not only genetic factors, but also environmental factors such as diet and stress. In addition, some evidence for sexual dimorphism in the zygomaticomaxillary complex was observed. Based on these findings, we recommend caution when using ZMS shape analysis in forensic ancestry determination.     

Y chromosome microsatellite genetic variation in two Native American populations from Argentina: Population stratification and mutation data

Two Native American populations from North and northwest regions of Argentina (Toba and Colla) were analyzed for 17 Y chromosome short tandem repeat loci (Y-STRs), namely, DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635 and GATA H4.1. Over 357 allele transfers, two one-step mutations could be detected at DYS456 and GATA H4.1 loci. A new 16.1 ‘micro-variant’ allele was observed for DYS385, characterized by an insertion at the fifth GAAA repeat. We also observed two alleles at the DYS448 locus in three samples (two from Toba and one from Colla). A total of 34 and 16 different haplotypes were detected for Toba and Colla, respectively, the former with a haplotype diversity value of 0.9769 ± 0.01, whereas 0.9497 ± 0.02 for the latter. Significant population differences were observed between Colla and Toba, at least in part, due to a more prevalent European input in the Colla. In agreement with this observation is the fact that the genetic distances between Colla and Iberian populations are lower than those observed between Iberian and any other Native American population. The results of multiscaling dimensional analysis and genetic distances (Rst) among Native American population samples also reflect this fact. The data show the existence of clear population stratification in the Argentina, a fact that should be taken into account in forensic casework.     

中国人股骨的性别鉴定

目的建立中国人股骨性别判定的方程。方法测量来自全国14省区的已知生前确切性别180例（男150例,女30例）个体的双侧股骨21项指标。使用统计软件SPSS13．0对获得的股骨测量项目数据,进行同一性别双侧间及不同性别同侧间的t检验,然后采用Fisher判别分析法和Bayes逐步判别分析法,建立股骨性别判定的系列判别函数。结果股骨单一测量指标中男性判别率最高指标为股骨上髁宽,为94．0％,女性判别率最高指标为股骨头周与股骨颈垂直径,为93．3％,总判别方程的判别率为男性98．0％,女性93．3％。结论本研究提供的判别方程式判别准确率较高,适用于中国人股骨的性别判定。     

A study of sexual dimorphism in the femur among North Indians

Determination of sex of unknown skeleton remains is the most important step in the identification process. Racial and regional differences in the populations create and maintain specificity in their dimorphic characteristics. Moreover, considering continued secular changes in the population structure, constant revision of osteometric standards becomes mandatory. In an effort to establish osteometric standards for the femur of contemporary North Indian populations, 122 adult femora of known sex (M: 94; F: 28) were collected in the Department of Forensic Medicine, IMS, BHU, Varanasi. Eight standard parameters were measured and analyzed by discriminant function analysis using SPSS 16. The accuracy of sex prediction ranged from 70.5% to 83.6% with single variables. In stepwise analysis, epicondylar breadth, proximal breadth, and antero-posterior diameter of the lateral condyle were found to be the most discriminating variables providing an accuracy of 90.2%. The results clearly indicate the importance of the ends of femur in the determination of sex.     

Sex determination of Chinese femur by discriminant function

The objective of this study was to provide a method of sex determination for Chinese femur, especially for fragmentary remains. Statistical analysis of 17 measurements based on 141 northeastern Chinese femora shows that all measurements have significant sex differences. Sex determination by the midpoint method of a single measurement can obtain an average accuracy of 76.8%. The results indicate that of all dimensions the maximum head diameter is the best discriminator of sex. It alone can determine the sex of a femur with 85.1% accuracy. The results also show that maximum head diameter, transverse head diameter, epicondylar breadth, upper breadth, and medial condylar length have higher sexual dimorphisms than the dimensions of length. According to the result to stepwise discriminant analysis and the need for sexing fragmentary remains, 22 discriminant functions composed of various combinations of variables were calculated which can determine the sex of the femur correctly 82.3 to 87.2%. The methods of sex determination provided by this paper can be used to sex poorly preserved femora.     

中国南方汉族人残碎股骨上端的性别判定

目的建立中国南方地区汉族人残碎股骨上端性别判别方法。方法对国内南方九省市的已知确切性别的100具股骨进行研究,测量股骨上端的7项指标,应用SPSS统计软件对数据进行分析,建立性别判别方程。结果7项指标中6项指标存在显著的性别差异,建立全指标及单指标的性别判别方程,判别率在59．6％～92．9％。结论建立的性别判别方程可以用于法医学实践。     

Some regularities in the shape of broken glass

Angles and curvatures of edges of glass fragments were measured. Some statistical regularities have been observed. This may be important for the assessment of the value of identification.     

足趾形状的模糊自动识别方法

目的根据足趾图像的模糊性和不同形状之间的过渡性,提出基于模糊理论的计算机足趾形状模糊识别方法。方法根据形状特征值的统计规律,分别从角度特征值、长度特征值两个不同的影响指标构造属于不同形状的隶属函数;然后以此隶属度作为单因数评判因子,采用综合评判和隶属度最大原则利用计算机对足趾图像形状进行自动识别。结果由于这种模糊识别方法更能客观、准确地反映出足趾的不同形状,所以使得计算机总体自动识别率达到91.5%。结论足趾形状的模糊自动识别方法在实际应用中是行之有效的。     

Determining body height by the femur and femoral fragments

Using a forensic series of human specimens, the reliability of frequently-cited formulas applied to estimate body height on the basis of the femur was examined with regard to their accuracy. Very few proved reliable enough to render accurate results. In most cases, less than half of the actual body heights were found to have predicted within the single estimation interval. The method to be used for such estimations must therefore be selected with great care. Even with partial femur measures, it is possible to estimate reliably body height. In particular, the circumference of the diaphysis centre correlates well with body height. The regression equations calculated in the present study, however, reveal greater errors in estimates than the formulas worked out using the total femur length.     

Estimation of age from the femur of Japanese cadavers

The purpose of this study is to estimate the age of cadavers by histomorphometry of the femur. Seventy-two Japanese males ranged from 43 days to 92 years old and 26 females ranged from 2 to 88 years old were used. The thickness of sections was adjusted at 50 to 70 microns by grinding with sand paper. The sections were not decalcificated. They were stained with Villanueva's bone staining powder and with thionin dye. Microradiographs of the sections were obtained by the soft X-ray apparatus. The area, maximum and minimum diameter, and perimeter of the perfect osteon and Haversian canal were measured. In addition, the type II osteon number, osteon fragment number, and area of triangle were also determined. All these parameters were examined by an image analyzer. The parameters of the osteon showed high correlation coefficient with age (magnitude of r > 0.77), while those of the Haversian canal were low (magnitude of r < 0.11). All parameters were subjected to multiple regression analysis for producing a multiple regression equation of age estimation. For the stepwise selecting method, the perimeter of osteon, maximum length of the Haversian canal and osteon fragment number were selected for the equation. Their multiple r2 and standard error of estimation were 0.8874 and 6.39, respectively. For the forward selection method, in addition to the above items, three parameters, the maximum length of Haversian canal, triangle area, osteon fragment number were selected. Their multiple r2 and standard error of estimation were 0.9484 and 4.884, respectively. Bone staining was useful to clarify the demarcation between osteon and fragment, leading to an increase in the accuracy of age estimation. However, the entire range from birth to 90 years was difficult to cover for precise age estimation.     

Compositional variation in bullet lead manufacture

The concentrations of antimony, copper, tin, arsenic, silver, bismuth, and cadmium in lead alloys produced by two smelters and one ammunition manufacturer were determined using inductively coupled plasma-atomic emission spectrometry. These element concentrations were used to measure the variations in composition of lead products that result from various processes involved in the manufacture of lead projectiles. In general, when a pot containing molten lead is used to cast a number of objects, these objects are similar, although not necessarily analytically indistinguishable in their elemental compositions. In each subsequent step in the processing of lead at the smelter and at the ammunition manufacturer, the size of an individual homogeneous melt of lead decreases as more distinct compositions are formed as a result of remelting and mixing of sources, including lead scrap. The ammunition manufacturer in this study produced at least 10 compositionally distinguishable groups of bullet wire in a 19.7-h period. The largest group could potentially be used to produce a maximum of 1.3 million compositionally indistinguishable 40 grain bullets.     

Pistol image retrieval by shape representation

Databases have been used to record data in forensic science, such as fingerprints, shoeprints, and photos. In traditional databases, we use “text” as the “keyword” for retrieving data (text-keyword retrieval); however, in some applications, “text” is not proper to describe the searching target, and in this case, “image” plays an important role. In this paper, we use “image features” as the “keywords”, and show its potential for building up a prototype of pistol image databases.In current firearm databases of forensic science, the retrieval method is still by text-keyword retrieval. For experienced forensic examiners, this kind of databases may satisfy their requirement. However, for people who have little gun knowledge, how can they find the possible gun candidates or similar guns in the databases, if there are not any available words or marks on the gun? In this paper, we try to retrieve similar pistol images by the pistol shape instead of “text-keyword”. This method can narrow down the searching range while identifying pistols by firearm databases.There are more than 300 pistol images in our pistol image database. From the experimental results, we can retrieve the similar pistol images in top five candidates for each pistol image.     

股骨颈骨折法医学鉴定的回顾性研究

目的 探讨股骨颈骨折后股骨头坏死的相关因素。方法 对69例股骨颈骨折的鉴定资料进行回顾性研究。结果69例股骨颈骨折的伤者,伤后4年内发生股骨头缺血坏死的21例,其中1～3年内发生缺血坏死者18例。根据股骨颈骨折的Garden分型,Ⅲ型股骨颈骨折后发生股骨头缺血坏死者9例,Ⅳ型11例,Ⅱ型1例。根据复位后的Garden指数分组,B组股骨颈骨折后发生股骨头缺血坏死者11例,A、C组各5例。结论 股骨颈骨折后股骨头坏死与股骨颈骨折的原始移位程度和骨折的复位质量(对位、对线情况)有关。     

马和人股骨碎片组织形态学结构特征及其鉴别

目的研究成体马和成年人的股骨组织形态学结构,分析其组织学特征,建立人与马之间的种属鉴别方法。方法取来源于尸体检验的成人右股骨中段约4cm,同时收集马的右腿股骨,取中段约4cm,脱钙后制作成厚约25μm的骨组织切片,在光学显微镜下观察,将显微镜下的图像录入电脑,选取25项指标进行逐步判别分析。结果马和人在哈氏系统数量、哈氏系统直径等13个指标上具有显著差异,用这些指标建立种属判别数学模型,经盲测检验,二者的判别率可达99.6%。结论马和人的股骨组织学结构具有明显的种属特征,建立的判别方程可以有效地鉴别马和人的股骨碎片。