Search

ABSTRACT We question the use of mechanical models, such as coin flipping, to represent the probabilities of gender distributions in sibship families consisting of two children. Both the assumptions of [...]

The need to segregate poultry based on sex is driven by sex-related differences in growth rate, market age, management practices, and nutritional requirements. Each day, poultry industry staff globally would ideally like to determine the sex of >150 million newly hatched birds. Currently, this can be done only manually at the hatchery, which is a virtually impossible undertaking. It is becoming more difficult each year to conduct manual sexing because this skill is disappearing from the workforce, is becoming unaffordable to the industry, and is encumbered by such negative effects as repetitive motion disorder. Automated sex sorting of eggs before hatching could resolve many, if not all, of these problems. We have developed a facile, rapid, and low-cost yeast-based assay that distinguishes male from female embryonated eggs before hatching based on the estrogen concentration of their allantoic fluid. Herein, we describe this novel sex-sorting technology, which we believe offers the potential to standardize and automate sex sorting in the poultry industry. Key words: allantoic fluid, embryonated egg, estrogen conjugate, sex sorting doi: 10.2527/jas.2009-2212

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.forsciint.2009.04.012 Byline: Paula N. Gonzalez, Valeria Bernal, S. Ivan Perez Keywords: Sexual dimorphism; Sciatic notch; Ischiopubic complex; Semilandmarks; Discriminant analysis; k-Means clustering Abstract: Sex estimation of skeletal remains is an important issue in both forensics and bioarchaeology. The chance of attaining a high level of accuracy regarding sex allocations is related to the skeletal component analyzed and the ability of the techniques employed to describe shape and size differences among the sexes. Current opinion regards the hip bone as the most reliable sex indicator because it is the most dimorphic bone, particularly in adult individuals. The aim of this study was therefore to analyze the greater sciatic notch and the ischiopubic complex morphology by employing geometric morphometric techniques, based on semilandmark and multivariate statistical methods, in order to develop a reliable and accurate technique for adult sex estimation. The sample analyzed consisted of 121 adult left hip bones randomly selected from the collection of documented skeletons housed at the Museu Antropologico de Coimbra. Morphometric analysis was based on coordinates of landmarks and semilandmarks of the ilium and ischiopubic regions that were digitized on 2D photographic images. Discriminant analysis with leave-one-out cross-validation and k-means clustering of shape and shape-size variables were used in order to classify individuals by sex. For the greater sciatic notch, average accuracy of 90.9% was achieved with both multivariate analyses based on shape variables. For the ischiopubic complex, the values obtained with shape variables were 93.4% and 90.1% for discriminant and k-means, respectively. Females were misclassified more frequently than males, especially for the ischiopubic complex. When multivariate statistical analyses were performed using shape-size variables, the percentages of correct classifications were lower than those obtained with shape variables. We conclude that the use of geometric morphometrics and multivariate statistics is a reliable method to quantify pelvic shape differences between the sexes and could be applied to discriminate between females and males. Author Affiliation: Division Antropologia, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Paseo del Bosque s/n, La Plata 1900, Argentina Article History: Received 13 August 2008; Revised 30 March 2009; Accepted 14 April 2009

Osteologists commonly assess the sex of skeletal remains found in forensic and archaeological contexts based on ordinal scores of subjectively assessed sexually dimorphic traits. Using known-sex samples, logistic regression (LR) discriminant functions have been recently developed, which allow sex probabilities to be determined. A limitation of LR is that it emphasizes main effects and not interactions. Chi-square automatic interaction detection (CHAID) is an alternative classification strategy that emphasizes the information in variable interactions and uses decision trees to maximize the probability of correct sex determinations. We used CHAID to analyze the predictive value of the 31 possible combinations of five sexually dimorphic skull traits that Walker used previously to develop logistic regression sex determination equations. The samples consisted of 304 individuals of known sex of English, African American, and European American origin. Based on practical considerations, selection criteria for the best sex predictive trait combinations (SPTCs) were set at accuracies for both sexes of 75% or greater and sex biases lower than 5%. Although several of the trees meeting these criteria were produced for the English and European American samples, none met them for the African American sample. In the series of out-of-sample tests we performed, the trees from the English and combined sample of all groups predicted best. KEY WORDS sex bias; logistic regression discriminant functions; decision trees

The identification of avian gender is important for prosperous breeding of birds. Since birds do not possess external genital organs, endoscopic investigations, blood analysis, and molecular biological methods are applied to determine the gender in monomorphic species. However, anesthesia and blood sampling impose stress on the examined bird and should be avoided in terms of animal protection. Here we report on the application of UV-resonance Raman spectroscopy as a minimal invasive method for gender determination of birds via an evaluation of feather pulp samples. Sample preparation for this investigation method is simple and facilitates a quick and easy analysis. The UV-resonance Raman spectra of the feather pulp sample extracts are dominated by DNA and protein signals. The different DNA content in male and female chicken allows for gender differentiation via its characteristic Raman fingerprint. The classification either to male or female chicken is ideally accomplished by support vector machines due to the fact that no unknown classes are involved. Recognition rates of about 95% were compared to less effective results of the unsupervised hierarchical cluster analysis. Within the scope of our investigations, principal component analysis was also applied to determine the important spectral regions for the classification of chicken's feather pulp samples.

A study has been conducted to develop a technique for identifying the gender of the beaver by examining the color and viscosity of anal gland secretions (AGS). Results revealed a high percentage of correctly identified sex of beaver in three regions of New York. The observations were consistent for all the discriminately identified beavers such that male beavers had Kraft brown- to sepia-colored and viscous AGS, while females had pale to medium olive, or warm gray, and less viscous AGS. These results indicate that color and viscosity of AGS are an effective approach for distinguishing sexes in beaver.

The vocalizations of wild and captive Whooping Cranes (Grus americana) were studied to determine if they can be reliably used as a method for sex determination in the monomorphic species. Sex discrimination by discriminant analysis gave a 98.8% successful classification rate, which is comparable to the rate for karyotype analysis. The method is therefore recommended for sex determination procedures for Whooping Cranes, either together with or replacing karyotype analysis.

The ventral arc of the pubis is frequently used for sexing adult human hip bones. This study addresses the issues of the anatomical and developmental bases for the ventral arc. Dissection of seven adult pelves (four females and three males) demonstrates that the sexes are identical in the muscular and ligamentous attachments to this ridge of bone. The tendons of gracilis and adductor brevis, which are fused for a variable extent, arise from the ridge of bone, and the fibers of the ventral pubic ligament attach to its medial border. Lateral placement of the ventral arc is defined in terms of the minimum distance between the ridge of bone and the inferior border of the symphyseal face of the pubis. The hypothesis that lateral placement of the ventral arc is positively correlated with pubic length was tested using two random samples of adult female hip bones (N = 50 for both whites and blacks) from the Hamann-Todd collection. The correlation between these variables is significant. The results support the argument that lateral placement of the ventral arc is related to the amount of postadolescent growth occurring at the symphyseal border of the pubis. Therefore, the ventral arc should not be considered as an independent criterion from pubic length in sexing adult hip bones.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.forsciint.2009.12.052 Byline: Venkatesh G. Naikmasur, Rahul Shrivastava, Sunil Mutalik Keywords: Sex determination; Cephalometric parameters; Discriminant function analysis; South Indian population; Tibetan population; Forensic anthropology population data Abstract: Skeletal components play significant role in sex determination in forensic and anthropological fields. Skull is considered second best, after pelvis, in determination of sex. Methods based on morphological characteristics and morphometry are already in use with reasonable accuracy. Standardized radiographic techniques like cephalometry have advantages of being more precise and objective when compared to morphologic methods. The present study aimed at obtaining and comparing the reliability of cranio-mandibular parameters in South Indian and Indian immigrant of Tibetan populations using lateral and postero-anterior (PA) cephalograms. A total of 11 cephalometric parameters were traced on lateral and PA cephalograms manually. Functions to aid in the sex determination were developed by subjecting the cephalometric parameters to discriminant analysis. Among the chosen parameters bizygomatic width, ramus height, depth of face contributed most for sexual dimorphism in both the populations. Upper facial height was the additional parameter for sexual dimorphism in immigrant Tibetan population. The discrimination accuracy in South Indian population was 81.5% while that of immigrant Tibetan population was 88.2%. With the current study it can be concluded that cephalometric cranio-mandibular parameters can be used to discriminate the sex using discriminant function analysis and similar cranio-mandibular parameters contribute to sex prediction across populations. Author Affiliation: Department of Oral Medicine and Radiology, S.D.M. College of Dental Sciences & Hospital, Dharwad, Karnataka 580 009, India Article History: Received 25 March 2009; Revised 10 December 2009; Accepted 16 December 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.forsciint.2009.12.049 Byline: Selma Uysal Ramadan (a), Nursel Turkmen (b), N. Anil Dolgun (c), Dilek Gokharman (a), Ritesh G. Menezes (d), Mahmut Kacar (a), UAur KoAar (a) Keywords: Forensic science; Forensic anthropology; Sternum; Sex determination; Computed tomography; Forensic anthropology population data Abstract: One of the most important data that can be obtained from bones is sex determination for which the recommended method is taking metric measurements. Metric measurements can be performed directly on dried bones obtained from the cadaver or indirectly from their radiographs. Author Affiliation: (a) Department of Radiology, Ankara Training and Research Hospital, Ankara, Turkey (b) Department of Forensic Medicine, Uludag University, Faculty of Medicine, Bursa, Turkey (c) Department of Biostatistics, Hacettepe University, Faculty of Medicine, Ankara, Turkey (d) Department of Forensic Medicine and Toxicology, Kasturba Medical College, Mangalore, India Article History: Received 18 August 2008; Revised 9 May 2009; Accepted 16 December 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.forsciint.2009.08.008 Byline: Sudeendra Prabhu (a), Ashith B. Acharya (b) Keywords: Forensic odontology; Sex determination; India; Univariate statistics; Discriminant function analysis; Reverse dimorphism Abstract: Sex determination of unidentified skeletal remains is important and various hard-tissue parameters have been evaluated towards this end. The dentition is considered as a useful adjunct in skeletal sex determination, particularly since teeth are resistant to postmortem destruction and fragmentation. Sex dimorphism in tooth size and the accuracy of odontometric sex prediction, is found to vary in different regions and researchers have advocated the need for population-specific data. No odontometric standards exist for Indians for use in forensic sex prediction. Therefore, this study examined sexual dimorphism in Indians using univariate and multivariate statistics. Mesiodistal (MD) and buccolingual (BL) measurements of all teeth, except third molars, were obtained from 105 Indians (53 females, 52 males). The mandibular first molar was found to be the most dimorphic tooth, followed by the canines and the BL dimension of maxillary first and second molars. While canines have, conventionally, shown the greatest degree of sexual dimorphism across populations, first molars have also been reported as the most or among the most sexually dimorphic teeth in some studies. Hence, apart from canines, the first molar would be the tooth most likely to exhibit the greatest univariate sexual dimorphism. In general, the mandibular teeth and BL dimensions showed greater tendency to be larger in males. However, nine tooth variables exhibited reverse dimorphism, i.e. female dimensions were larger than those of males. Overall, using univariate analysis, merely 37.5% of all tooth variables were statistically larger in males (p Author Affiliation: (a) Department of Oral Pathology, S.D.M. College of Dental Sciences and Hospital Sattur, Dharwad 580009, India (b) Department of Forensic Odontology, S.D.M. College of Dental Sciences and Hospital, Sattur, Dharwad 580009, India Article History: Received 6 February 2009; Accepted 13 August 2009 Article Note: (footnote) [star] Portions of this paper have been presented at the 6th National Conference of the Indian Association of Forensic Odontology, 4-5 October 2008, Dharwad, Karnataka State, India.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.forsciint.2009.07.014 Byline: Ph. du Jardin (a), J. Ponsaille (b), V. Alunni-Perret (c), G. Quatrehomme (c) Keywords: Forensic anthropology; Neural network; Femoral sexual dimorphism; Femur; Discriminant analysis; Logistic regression Abstract: Forensic anthropologists are frequently asked to assess partial or badly damaged skeletal remains. One such request led us to compare the predictive accuracy of different mathematical methods using four non-standard measurements of the proximal femur (trochanter-diaphysis distance (TD), greater-lesser trochanter distance (TT), greater trochanter width (TW) and trochanter-head distance (TH)). These measurements were taken on 76 femurs (38 males and 38 females) of French individuals. Intra- and inter-observer trials did not reveal any significant statistical differences. The predictive accuracy of three models built using linear and non-linear modelling techniques was compared: discriminant analysis, logistic regression and neural network. The neural network outperformed discriminant analysis and, to a lesser extent, logistic regression. Indeed, the best results were obtained with a neural network that correctly classified 93.4% of femurs, with similar results in males (92.1%) and females (94.7%). Univariate functions were less accurate (68-88%). Discriminant analysis and logistic regression, both using all four variables, led to slightly better results (88.2% and 89.5%, respectively). In addition, all the models, save the neural network, led to unbalanced results between males and females. In conclusion, the artificial neural network is a powerful classification technique that may improve the accuracy rate of sex determination models for skeletal remains. Author Affiliation: (a) Edhec Business School, 400 Promenade des Anglais, 06000 Nice, France (b) Laboratoire de Medecine Legale et Anthropologie medico-legale, Faculte de Medecine, Universite de Nice Sophia Antipolis, 28 Avenue de Valombrose, 06100 Nice, France (c) Laboratoire de Medecine Legale et Anthropologie medico-legale, Faculte de Medecine, UMR 6235 CNRS, Gepitos, Universite de Nice Sophia Antipolis, France Article History: Received 11 March 2008; Revised 29 June 2009; Accepted 16 July 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.forsciint.2009.04.014 Byline: Elena F. Kranioti (a), Nikolaos Vorniotakis (b), Christianna Galiatsou (b), Mehmet Y. A[degrees]Acan (c), Manolis Michalodimitrakis (a) Keywords: Forensic anthropology; Sex determination; Digital radiographs; Femur; SIS software; Java Abstract: The determination of sex is considered one of the first essential steps in positive identification. The current study aspires to accomplish a threefold purpose: to develop an easy and rapid sex determination technique using digital radiographs from the proximal epiphysis of the femur, to develop a simplified tool for pathologists that will provide accurate sex identification using radiographs and to compare this method with standard osteometric techniques applied to the same population. A total of 70 (36 males and 34 females) left femora were measured according to standard osteometric techniques. The proximal epiphyses of the same sample were then radiographed using a digital X-ray machine (TCA 4R PLUS). The skeletal remains were selected from the exhumed skeletons of St. Konstantinos and Pateles Cemeteries, Heraklion, Crete. Nine classical measurements were taken from the entire dry femora. Stepwise discriminant function analysis selected only 2 dimensions (maximum head diameter and anterior-posterior midshaft diameter) producing an accuracy rate of 88.6% for both original and cross-validated data. If assuming that only the proximal part of the femur is present, direct procedure results in 87.1% correct group membership. Six landmarks were selected in the radiograph and 15 variables representing all possible combinations of these landmarks were calculated using a specially designed calibrated Java program. Measurements were submitted to discriminant function analysis using SPSS subroutines. Stepwise discriminant function analysis selected only 3 out of 15 dimensions, producing an accuracy rate of 92.9%. The formula generated was then incorporated into the Java application, resulting in the development of a sex identification software (SIS). A sample of 36 (23 left and 13 right) femoral radiographs was used in order to test the software's reliability and sex was correctly identified in 32/36 cases, giving an accuracy rate of 91.7%. The radiographic technique proposed here performed better compared to conventional methods in the same population. From a forensic point of view it is a useful alternative method when semi-decomposed or charred remains are recovered in mass disasters or crime scenes and maceration is not an option. The application of metric methods in radiographs and the development of a highly specific software provides a useful and easy tool for sex identification that can be used in certain forensic cases in which osteometry does not apply. Author Affiliation: (a) Department of Forensic Sciences, University of Crete Medical School, 71110 Heraklion, Greece (b) Department of Applied Informatics & Multimedia, Technological Educational Institute of Crete, Heraklion, Greece (c) Adli Tip Enstitusu, Istanbul University, CerrahpaAa, Istanbul, Turkey Article History: Received 17 April 2008; Revised 23 March 2009; Accepted 14 April 2009

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.forsciint.2009.04.013 Byline: Elena F. Kranioti (a)(b), Markus Bastir (a), Andrea Sanchez-Meseguer (a), Antonio Rosas (a) Keywords: Geometric-morphometrics; Forensic anthropology; Sex identification; Humerus; Digital radiographs Abstract: Various scholars have pioneered sex assessment from different parts of the skeleton based on metrical or qualitative morphological characteristics. Lately though, a new technique which combines both traditional methods is becoming popular in forensic anthropology. Geometric-morphometrics is a field of multivariate statistical biometric analysis which allows the quantification of the shape and size components of morphological variation. The purpose of this investigation is to assess sex from the humerus in a contemporary Greek population using geometric-morphometric analysis of shape data derived from digital radiographs. The study population consists of 97 well-preserved adult humeri from two cemeteries of Heraklion, Crete. The left humeri are radiographed using digital radiograph machine (TCA 4R PLUS). Assuming fragmentary patterns, the proximal and distal ends are studied separately. Five landmarks are selected on the radiograph of the proximal epiphysis and seven landmarks on the distal. Generalised Procrustes analysis (GPA) and thin-plate splines are used to obtain the shape and size variables for statistical analysis. Then three discriminant function analyses were carried out: one uses the PC scores from Procrustes shape space, the second the centroid size alone and the third the PC scores of GPA residuals plus lnCS for analysis in Procrustes form space. Results indicate the existence of shape differences between the sexes. In females the greater tubercle is smoother, with its superior border less pronounced. Additionally, females have a relatively squared distal epiphysis, while males exhibit a more rectangular shape. Shape differences between genders, for the cross-validated data, give slightly better classification results in the proximal humerus (73%) compared with the distal humerus (71%). Size alone performed better (86.5% for proximal and 85.6% for distal humerus). As anticipated, the classification accuracy improves (89.6% for proximal and 89.7% for distal epiphysis) when both size and shape are combined. From the forensic standpoint, the usefulness of this study rests on the identification of sex based on shape differences observed on radiographs of fragmentary humeri that could not be assessed with traditional methods. The analysis of humeral radiographs by geometric-morphometric techniques offers an alternative way to identify the sex of unknown skeletal remains. Whether this is statistically better than simply using traditional osteometric methods is a question that needs to be tested in a meta-statistical approach. Author Affiliation: (a) Department of Paleobiology, Museo Nacional de Ciencias Naturales (CSIC), C/Jose Gutierrez Abascal, Madrid 228006, Spain (b) Department of Forensic Sciences, University of Crete Medical School, Heraklion, Greece Article History: Received 11 March 2008; Revised 16 February 2009; Accepted 14 April 2009

Determining the sex of a newborn baby is usually a simple matter. Routine examination of the external genitalia will, in most cases, identify the sex of the infant. But when this is not a clear-cut decision, due to some birth defect, the gender identity must be rapidly, but carefully, assigned. If there are palpable sex organs in the genital region and an identifiable uterus, the gender assigned must be female, regardless of any phallic structure. These infants have a genetic defect in the Y chromosome or a translocation of the testis-determining factor to one of the X chromosomes. The specific diagnosis may be made by a Southern blot analysis. Any testicular tissue should be surgically removed to avoid virilization or growth of tumors in the future. Newborns without palpable gonads, but with a uterus, should be assigned the female gender. Virilization may be due to a variety of abnormalities. Babies without any palpable gonads or uterus, but with a phallic structure of at least 2 cm, should be assigned the male gender. If the phallus is inadequate or absent, the female gender should be assigned. This defect may require hormonal therapy or appropriate surgical intervention. Newborns with symmetrically descended gonads and no uterus should be assigned the male gender. In the presence of an anatomic defect, the baby should be examined for other organ malformations. Rapid gender assignment is critical to the proper care of the infant and the psychological well-being of the child and family. (Consumer Summary produced by Reliance Medical Information, Inc.)