Analysis of quantitative methods for rib seriation using the Spitalfields documented skeletal collection

Accurate rib seriation is essential in forensic anthropology and bioarchaeology for determination of minimum numbers of individuals, sequencing trauma patterns to the chest, and identification of central ribs for use in age estimation. We investigate quantitative methods for rib seriation based on three metric variables: superior (anterior) costo-transverse crest height (SCTCH), articular facet of the tubercle-to-angle length (AFTAL), and head-to-articular facet length (HAFL). The sample consists of complete but unseriated sets of ribs from 133 individuals from the documented (known age and sex) and undocumented skeletal collections of Christ Church Spitalfields, London. This research confirms the results of an earlier study (Hoppa and Saunders [1998] J. Forensic. Sci. 43:174-177) and extends it with the application of two new metric traits and further analyses of sex differences. Analyses of variance showed that SCTCH and AFTAL are significantly associated (P < 0.001) with rib number. Tukey tests of pairwise rib comparisons revealed that for two dimensions (SCTCH and AFTAL), the central ribs (3rd-6th) are significantly distinct from each other (P < 0.05). Using simple ranking of either the SCTCH or AFTAL traits, the proportion of correctly identified ribs within +/-1 position was 80%, compared to initial seriation using morphological methods (Dudar [1993] J. Forensic. Sci. 28:788-797; Mann [1993] J. Forensic. Sci. 28:151-155). Significant sex dimorphism was also identified for these two traits. Analysis of the HAFL trait produced somewhat equivocal results, suggesting that this variable is not reliable for rib seriation. The variable SCTCH proves to be the most useful dimension for seriation, and shows that all but the 7th-9th ribs can be distinguished from others in the sequence, with important results for the 4th rib, where ranking allowed identification in 86% of cases, consistent with morphological methods for intact ribs.     

Intercostal variation for age estimation--are the standards for the right 4th rib applicable for other ribs?

Age estimation of unknown skeletal remains is very important in forensic medicine. Morphologic methods are fast and easy to use for purpose of age determination. The sternal ends of the ribs are a reliable method of age estimation from late adolescence to old age. Iscan et al developed a phase analysis method for the right 4th rib that was sex and race specific. The purpose of this study is to determine the accuracy of the standards of age estimation from the right 4th and other rib using the phase analysis for the Turkish population. The sample consisted of right and left 3rd, 4th and 5th ribs from 34 Turkish women and 76 men. There were statistically significant variations found on the right 5th, left 3rd, 4th, and 5th ribs according to these standards in men for phases 5, 6, and 7. For women, all the right and left ribs included in this study were in concordance with right 4th rib standards in all phases.     

伞形科东当归的果实形态和解剖结构

对伞形科(Apiaceae)当归属(Angelica L.)东当归〔A.acutiloba(Sieb.et Zucc.)Kitag.〕的分生果形态特征和解剖结构进行了全面观察。该种分生果的外观呈倒椭圆状长卵形,有三角状萼齿,果棱、棱槽和腹面表面均有黄白色斑点。果实横切面解剖结构具有以下特征:外果皮终止于果棱顶端的腹面处,合生面宽阔,外果皮和中果皮细胞中有大量淡黄色晶体,油管在棱槽和合生面处连续分布等。东当归的这些果实形态及解剖结构明显不同于当归属的其他种类,其分类地位有待重新探讨。     

Calcaneal measurement in estimation of stature of South African blacks

Stature (height) is an important factor in establishing the identity of a person in the living as well as in the skeletonized state. When stature is estimated from the bones of the limbs, regression equations, which estimate the ratios of the lengths of bones to the height of the individual, are generated. The majority of bones that were used previously were the long bones. The calcaneus was used for estimating stature only in American whites and blacks (Holland [1995] Am. J. Phys. Anthropol. 96:315-320). The regression equations that he generated were found to be useful for stature estimation in these population groups. Since the calcaneus has not been used for the same purpose in South Africa, the aim of this study was to derive regression equations that will allow this bone to be used for stature estimation in South African blacks. In total, 116 complete skeletons (60 males and 56 females) were selected from the Raymond A. Dart Collection of Human Skeletons, School of Anatomical Sciences, University of the Witwatersrand (Johannesburg, South Africa). The skeletal heights of these sets of skeletons were calculated using the anatomical method of Fully ([1956] Ann. Med. Leg. 35:266-273). Nine parameters of the calcaneus were measured and matched against skeletal heights, using univariate and multivariate regression methods. Regression equations were obtained for estimation of the stature of the South African black population from the calcaneus. The standard error of estimate that was obtained with univariate regression analysis was higher than the corresponding values using multivariate regression analysis. In both cases, the standard errors of estimate compared well with the values obtained for fragmentary long bones by previous authors.     

Using multivariate adaptive regression splines to estimate subadult age from diaphyseal dimensions

Subadult age estimation is considered the most accurate parameter estimated in a subadult biological profile, even though the methods are deficient and the samples from which they are based are inappropriate. The current study addresses the problems that plague subadult age estimation and creates age estimation models from diaphyseal dimensions of modern children. The sample included 1,310 males and females between the ages of birth and 12 years. Eighteen diaphyseal length and breadth measurements were obtained from Lodox Statscan radiographic images generated at two institutions in Cape Town, South Africa, between 2007 and 2012. Univariate and multivariate age estimation models were created using multivariate adaptive regression splines. k‐fold cross‐validated 95% prediction intervals (PIs) were created for each model, and the precision of each model was assessed. The diaphyseal length models generated the narrowest PIs (2 months to 6 years) for all univariate models. The majority of multivariate models had PIs that ranged from 3 months to 5 and 6 years. Mean bias approximated 0 for each model, but most models lost precision after 10 years of age. Univariate diaphyseal length models are recommended for younger children, whereas multivariate models are recommended for older children where the inclusion of more variables minimized the size of the PIs. If diaphyseal lengths are not available, multivariate breadth models are recommended. The present study provides applicable age estimation formulae and explores the advantages and disadvantages of different subadult age estimation models using diaphyseal dimensions. Am J Phys Anthropol 154:376–386, 2014. © 2014 Wiley Periodicals, Inc.     

Methods for estimating missing human skeletal element osteometric dimensions employed in the revised fully technique for estimating stature

One of the greatest limitations to the application of the revised Fully anatomical stature estimation method is the inability to measure some of the skeletal elements required in its calculation. These element dimensions cannot be obtained due to taphonomic factors, incomplete excavation, or disease processes, and result in missing data. This study examines methods of imputing these missing dimensions using observable Fully measurements from the skeleton and the accuracy of incorporating these missing element estimations into anatomical stature reconstruction. These are further assessed against stature estimations obtained from mathematical regression formulae for the lower limb bones (femur and tibia). Two thousand seven hundred and seventeen North and South American indigenous skeletons were measured, and subsets of these with observable Fully dimensions were used to simulate missing elements and create estimation methods and equations. Comparisons were made directly between anatomically reconstructed statures and mathematically derived statures, as well as with anatomically derived statures with imputed missing dimensions. These analyses demonstrate that, while mathematical stature estimations are more accurate, anatomical statures incorporating missing dimensions are not appreciably less accurate and are more precise. The anatomical stature estimation method using imputed missing dimensions is supported. Missing element estimation, however, is limited to the vertebral column (only when lumbar vertebrae are present) and to talocalcaneal height (only when femora and tibiae are present). Crania, entire vertebral columns, and femoral or tibial lengths cannot be reliably estimated. Further discussion of the applicability of these methods is discussed.     

Geometry and kinematics of dog ribs

Five anesthetized supine beagle dogs were scanned using a fast, multislice computed tomographic X-ray technique to determine the orientation of the ribs at total lung capacity (TLC) and functional residual capacity (FRC). A plane was fit to each rib using a coordinate system in which the z-axis was aligned approximately cephalocaudally and the x-z-plane coincided with the sagittal midplane. The orientation of each plane was described by "pump-handle" and "bucket-handle" angles. The ribs rotated downward and inward during a passive deflation of the lungs from TLC to FRC. Rib displacement was not uniform: bucket-handle motion was predominant in the upper ribs, and pump- and bucket-handle motions were equal in the lower ribs. The change in the pump-handle angles between TLC and FRC was approximately 6 degrees for ribs 3-8, and the change in the bucket-handle angles decreased with rib number from 16 degrees for rib 3 to 6 degrees for rib 8. Rib shape was described by fitting an ellipse to the data for each rib; the ribs became larger and more circular with increasing rib number.     

Fourier transform infrared spectroscopic imaging and multivariate regression for prediction of proteoglycan content of articular cartilage

Fourier Transform Infrared (FT-IR) spectroscopic imaging has been earlier applied for the spatial estimation of the collagen and the proteoglycan (PG) contents of articular cartilage (AC). However, earlier studies have been limited to the use of univariate analysis techniques. Current analysis methods lack the needed specificity for collagen and PGs. The aim of the present study was to evaluate the suitability of partial least squares regression (PLSR) and principal component regression (PCR) methods for the analysis of the PG content of AC. Multivariate regression models were compared with earlier used univariate methods and tested with a sample material consisting of healthy and enzymatically degraded steer AC. Chondroitinase ABC enzyme was used to increase the variation in PG content levels as compared to intact AC. Digital densitometric measurements of Safranin O-stained sections provided the reference for PG content. The results showed that multivariate regression models predict PG content of AC significantly better than earlier used absorbance spectrum (i.e. the area of carbohydrate region with or without amide I normalization) or second derivative spectrum univariate parameters. Increased molecular specificity favours the use of multivariate regression models, but they require more knowledge of chemometric analysis and extended laboratory resources for gathering reference data for establishing the models. When true molecular specificity is required, the multivariate models should be used.     

Changes in chest wall structure and elasticity in elastase-induced emphysema

The present study examined the effects of elastase-induced emphysema on the structure and elasticity of the chest wall. Specifically, we examined the passive pressure-volume relationship of the intact chest wall in anesthetized animals and the stress-strain relationship of the isolated rib cage devoid of respiratory musculature. The structure of the isolated rib cage was assessed by measuring its circumferential, anterior-posterior, and transverse dimensions, the angles of articulation of the ribs at the costovertebral and sternochondral joints, and the length of the sternum and individual ribs. Studies were performed in 10 Syrian Golden hamsters, 26-27 wk after intratracheal injection of elastase, and 9 saline-injected hamsters that served as controls. Mean functional residual capacity of emphysematous animals was 239% of the value obtained in control animals. In emphysematous animals, the pressure-volume curve of the chest wall was shifted parallel and to the left of the curve obtained in controls. That is, at any given esophageal pressure, lung volume was significantly greater in emphysematous animals compared with controls, but the slope of the pressure-volume relationship was similar in the two groups. In the relaxed position, the circumference, anterior-posterior, transverse, and rostral-caudal dimensions of the thorax were significantly greater in emphysematous than control animals. Although the length of the thoracic spinal column was the same in both groups, the length of the ribs and sternum were greater in emphysematous animals and the angles of articulation of the ribs with the vertebrae and sternum were altered.(ABSTRACT TRUNCATED AT 250 WORDS)     

The myth of dorsal ribs in gnathostome vertebrates

Traditionally, two types of rib are distinguished in gnathostomes: dorsal (upper) and ventral (lower, pleural) ribs. They are defined according to their position in the connective tissue system of the body: dorsal ribs develop at the intersection of the serially arranged myosepta with the horizontal septum that separates epaxial from hypaxial musculature, whereas ventral ribs develop at the intersection of myosepta with the peritoneum and usually encircle the body cavity. Distribution of rib types among gnathostomes has traditionally been reported as follows: elasmobranchs have dorsal ribs; all Actinopterygii have only ventral ribs with the exception of polypterids, and two subgroups of teleosts, which supposedly also have dorsal ribs; within Sarcopterygii tetrapods have dorsal ribs, whereas dipnoans have ventral ribs. Here, we report the development of ribs in polypterids, a taxon playing a crucial role in discussions on rib homology. We demonstrate that putative dorsal ribs of polypterids have a unique ontogeny and represent an autapomorphy of this taxon. We discuss previous hypotheses of rib homology and offer a more plausible (i.e. more parsimonious) alternative to the conventional interpretation. We conclude that dorsal ribs do not exist and that ribs of gnathostomes are ventral ribs.     

Phylogenetic ANOVA: Group‐clade aggregation,biological challenges,and a refined permutation procedure

Phylogenetic regression is frequently used in macroevolutionary studies, and its statistical properties have been thoroughly investigated. By contrast, phylogenetic ANOVA has received relatively less attention, and the conditions leading to incorrect statistical and biological inferences when comparing multivariate phenotypes among groups remain underexplored. Here, we propose a refined method of randomizing residuals in a permutation procedure (RRPP) for evaluating phenotypic differences among groups while conditioning the data on the phylogeny. We show that RRPP displays appropriate statistical properties for both phylogenetic ANOVA and regression models, and for univariate and multivariate datasets. For ANOVA, we find that RRPP exhibits higher statistical power than methods utilizing phylogenetic simulation. Additionally, we investigate how group dispersion across the phylogeny affects inferences, and reveal that highly aggregated groups generate strong and significant correlations with the phylogeny, which reduce statistical power and subsequently affect biological interpretations. We discuss the broader implications of this phylogenetic group aggregation, and its relation to challenges encountered with other comparative methods where one or a few transitions in discrete traits are observed on the phylogeny. Finally, we recommend that phylogenetic comparative studies of continuous trait data use RRPP for assessing the significance of indicator variables as sources of trait variation.     

Whole-genome resequencing identified candidate genes associated with the number of ribs in Hu sheep

The number of ribs is an important economic trait in the sheep industry when the sheep are raised for mutton. However, in sheep, the genetic mechanisms regulating rib number are poorly understood. In the present study, we aimed to identify important candidate genes that affect the increase in rib number in sheep. Whole-genome resequencing of 36 Hu sheep with an increased number of ribs (R14) and 36 sheep with normal (R13) rib numbers was carried out. Analysis using three methods (fixation index (F_ST), Fisher's exact test, and Chi-squared test) showed that 219 single nucleotide polymorphism sites overlapped among the results of the three methods, which represented 206 genes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that the genes were mainly associated with regulation of developmental process, inorganic anion transport, cellular biosynthetic process, tight junction, the oxytocin signaling pathway, and arrhythmogenic right ventricular cardiomyopathy. Four mutations were selected according to the significantly selected genomic regions and important pathways for genotyping and association analysis. The result demonstrated that three synonymous mutations correlated significantly with the rib number. Importantly, we revealed that the CPOX (encoding coproporphyrinogen oxidase), KCNH1 (encoding potassium voltage-gated channel subfamily H member 1), and CPQ (encoding carboxypeptidase Q) genes have a combined effect on rib number in Hu sheep. Our results identified candidate molecular markers for rib number in sheep breeding.     

中国棱子芹属16种1变种的果实特征及其分类学意义

采用石蜡切片法对中国棱子芹属植物16种1变种进行了果实外部形态和解剖特征观察,研究了分生果大小、果棱形状、油管数目、胚乳形状等特征,文中探讨了部分棱子芹属植物的分类地位,为该属的系统分类研究及分类问题的解决提供了佐证。主要结论如下:(1)棱子芹属植物果实解剖特征在种间存在明显差异,在种内性状比较稳定。(2)所研究的棱子芹属植物果实在外部形态和解剖结构表现出较高的多态性和一定的规律性,可以为棱子芹属近缘种的鉴定提供重要的参考性状。(3)结合果棱性状、油管数目等解剖结构和前人分子系统学研究证据,研究认为真正的棱子芹属植物其成熟果实外果皮膨胀,果棱远端具空囊,中果皮和维管束形成的内棱较不显著。     

Geometry and respiratory displacement of human ribs

The three-dimensional coordinates of points in the ribs of two supine relaxed males, holding their breath at functional residual capacity (FRC) and with their glottis closed at total lung capacity (TLC), were obtained from volumetric X-ray computed tomographical images. The orientation of planes that best fit the data for each rib at each lung volume and the circular arcs that fit the points in the planes of the ribs were determined, and average values of these geometrical parameters for ribs 3-7 are reported. The planes of the ribs at TLC can be described as displaced from the planes at FRC by a rotation about an axis that passes near the spine. The pump handle and bucket handle components of rotation are 11 and 13 degrees, respectively, for rib 3 and both decrease with increasing rib number to 7 and 10 degrees at rib 7. The angles between the axes of rotation and the midplane are approximately 35 degrees for all 5 ribs. The radii of the circular arcs fit to the data at TLC are slightly larger than those at FRC, and this suggests that there is a small component of rotation normal to the plane of the rib.     

Comparison of three multitrait methods for QTL detection

A comparison of power and accuracy of estimation of position and QTL effects of three multitrait methods and one single trait method for QTL detection was carried out on simulated data, taking into account the mixture of full and half-sib families. One multitrait method was based on a multivariate function as the penetrance function (MV). The two other multitrait methods were based on univariate analysis of linear combination(s) (LC) of the traits. One was obtained by a principal component analysis (PCA) performed on the phenotypic data. The second was based on a discriminate analysis (DA). It calculates a LC of the traits at each position, maximising the ratio between the genetic and the residual variabilities due to the putative QTL. Due to its number of parameters, MV was less powerful and accurate than the other methods. In general, DA better detected QTL, but it had lower accuracy for the QTL effect estimation when the detection power was low, due to higher bias than the other methods. In this case, PCA was better. Otherwise, PCA was slightly less powerful and accurate than DA. Compared to the single trait method, power can be improved by 30% to 100% with multitrait methods.     

Craniometric variation in Norwegian wolverines Gulo gulo L.

Craniometric variation in Norwegian wolverines was analysed using univariate and multivariate techniques. The wolverine skull seems to be full-grown after about 9 months in both sexes although some dimensions continued to grow at a slow rate after the first year. Size allometry was studied in skulls older than 11 months. Allometric coefficients were calculated from different methods. The multivariate allometric coefficients were found to reflect the same allometric patterns as were found from the reduced major axis and from the direction cosines of PCI, whereas the coefficients seem to be underestimated by the least-square regression method. Sexual dimorphism was found to be highly significant, males being the larger sex. The female skulls were found to be relatively broader and to have a relatively higher coronoid process than the male skulls. It seems that the females have a relatively stronger feeding apparatus than the males, which leads to less absolute differences in strength, as reflected in a very high degree of dietary overlap. Two discriminant functions were calculated which both classified the material into their correct sex with nearly 100% accuracy. Geographical variation between samples from Nordland and Finnmark counties were studied. No significant multivariate variation was found between the female skulls. The male variation was highly significant; the Nordland skulls seem to have longer carnassials than those from Finnmark.     

Craniometric variation in Norwegian wolverines Gulo gulo L.

Craniometric variation in Norwegian wolverines was analysed using univariate and multivariate techniques. The wolverine skull seems to be full-grown after about 9 months in both sexes although some dimensions continued to grow at a slow rate after the first year. Size allometry was studied in skulls older than 11 months. Allometric coefficients were calculated from different methods. The multivariate allometric coefficients were found to reflect the same allometric patterns as were found from the reduced major axis and from the direction cosines of PCI, whereas the coefficients seem to be underestimated by the least-square regression method. Sexual dimorphism was found to be highly significant, males being the larger sex. The female skulls were found to be relatively broader and to have a relatively higher coronoid process than the male skulls. It seems that the females have a relatively stronger feeding apparatus than the males, which leads to less absolute differences in strength, as reflected in a very high degree of dietary overlap. Two discriminant functions were calculated which both classified the material into their correct sex with nearly 100% accuracy. Geographical variation between samples from Nordland and Finnmark counties were studied. No significant multivariate variation was found between the female skulls. The male variation was highly significant; the Nordland skulls seem to have longer carnassials than those from Finnmark.     

Secondary osteon and Haversian canal dimensions as behavioral indicators

Variation in the size of structures within mature cortical bone is relevant to our understanding of apparent differences between human samples, and it is relevant to the development of histologically based age-estimation methods. It was proposed that variation may reflect effects of physical activity, through biomechanical and/or metabolic mechanisms. If these factors are local, femoral osteon area (On.Ar) should be more histologically variable than On.Ar in ribs. Ribs should show a higher variation in Haversian canal area (H.Ar) if they are sites of more remodeling activity and hence of arrested refilling of secondary osteons at time of death. This study compares On.Ar and H.Ar of secondary osteons from femora (15) and ribs (29) from 44 Holocene (Later Stone Age) foragers from South Africa (M = 19, F = 25) to values from paired femora and ribs from historic samples (Spitalfields and St. Thomas, 20 pairs from each). Fixed-effects analysis of variance demonstrates rib On.Ar to be significantly smaller than femur, but with no sex or age effects. The femur-to-rib On.Ar ratio is lower for the Holocene foragers than for the two modern samples because of relatively large rib On.Ar. Femora and ribs from the same skeleton normally show femoral On.Ar larger than rib On.Ar (37/44 pairs). Mean femoral values of On.Ar are more diverse than rib On.Ar values, but within-sample coefficients of variation are similar. Values for H.Ar are highly variable and do not reflect anatomical site, age, sex, or population effects. The patterning of osteon size does not appear to be linked to physical activity or to different rates of metabolic activity within the skeleton, at least not in a straightforward way.     

The two mechanisms of intercostal muscle action on the lung.

The mechanisms of respiratory action of the intercostal muscles were studied by measuring the effect of external forces (F) applied to the ribs and by modeling the effect of F exerted by the intercostal muscles. In five dogs, with the airway occluded, cranial F were applied to individual rib pairs, from the 2nd to the 11th rib pair, and the change in airway opening pressure (Pao) was measured. The ratio Pao/F increases with increasing rib number in the upper ribs (2nd to 5th) and decreases in the lower ribs (5th to 11th). These data were incorporated into a model for the geometry of the ribs and intercostal muscles, and Pao/F was calculated from the model. For interspaces 2-8, the calculated values agree reasonably well with previously measured values. From the modeling, two mechanisms of intercostal muscle action are identified. One is the well-known Hamberger mechanism, modified to account for the three-dimensional geometry of the rib cage. This mechanism depends on the slant of an intercostal muscle relative to the ribs and on the resulting difference between the moments applied to the upper and lower ribs that bound each interspace. The second is a new mechanism that depends on the difference between the values of Pao/F for the upper and lower ribs.     

Fruit structure of 12 Turkish endemic <Emphasis Type="Italic">Tripleurospermum</Emphasis> Sch. Bip. (Asteraceae) taxa and its taxonomic implications

This study concerns the evaluation of micromorphological and anatomical characters of fruit (achene-cypsela) in 12 Turkish endemic Tripleurospermum taxa using multivariate analyses (cluster analysis, principal component analysis, one-way analysis of variance). Pericarp in all taxa examined is mainly composed of several layers of parenchymatous and sclerenchymatous cells with one vascular bundle in each rib. In the achene, the thickness and width of lateral and adaxial ribs with presence or absence of a slime envelope have high taxonomic value for Tripleurospermum at interspecific levels. The slime envelope formation is also correlated with ploidy levels and habitats of some taxa in Tripleurospermum.