Stepwise Discriminant Function Research Articles

Classification of Children with Chronic Headache from Children without Headache by Stress-Related Biological and Psychological Characteristics

Stress-related psychological and biological characteristics were used to classify young girls to predict girls with chronic headache. This was done by stepwise discriminant function analysis that included at each step biological and psychological characteristics of stress load and stress coping to identify the best predictive power which was evaluated by canonical correlation coefficients. At each step psychological stress load was significant. Lack of problem-solving and seeking social support were important. Also passive avoidance and destructive stress coping. The best classification quality was obtained, when depression and anxiety of the children were included in discriminant function. Hyperactivity of HPA axis did not play an important role.

Development of yield forecast models with raw data through stepwise regression analysis (forward method) and discriminant function analysis for pigeon pea crop on Chhattisgarh plain zone

Under this investigation we studied about minimization of weekly data through stratification and Simple Randon Sample technique. Individual effect of weather parameters has been considered under the study. Forecasting model developed on two statistical technique i.e. Stepwise Regression Analysis (Forward Method) technique and Discriminat Function Analysis technique. Both the techniques are found very suitable for the district wise and zone level pre-harvest forecast for the pigeonpea crop on Chhattisgarh. Models fitted with the Stepwise Regression Analysis on 35 variables and Time Trend (T) for Zone. The developed model is showing best fit on the basis of very high value of significance and maximum R2 (84%) for the plain Zone, highly significant at 0.1% level of significance and models fitted with DFA then 2 Discriminant score (ds1 and ds2) and Time Trend (T) the models found highly significant and R2 value 69% for plain zone for Pigeonpea crop. The developed model has been validated by the error parameters viz. Minimum MAE, Minimum MSE, Minimum RMSE, Minimum PE and Minimum PD along with maximum R2. These developed models are useful to farmers of Chhattisgarh to decide their future prospects and possible course of action in advance. This was very challenging task for the researchers to develop a precise & accurate and best fit model for the future forecast. May this study will clear the fog through new methodology and also will create the new way on the direction of forecast.

Forensic Tools for Species Identification of Skeletal Remains: Metrics, Statistics, and OsteoID.

Simple SummaryForensic anthropologists are commonly asked to determine whether bones are of human origin and, if not, to which species they belong. Current practice usually relies on visual assessments rather than quantitative analyses. This study aimed to test the utility of basic bone metrics in discriminating human from nonhuman elements and assigning faunal species. A database of more than 50,000 skeletal measurements was compiled from humans and 27 nonhuman species. Equations and classification trees were developed that can differentiate human from nonhuman species with upwards of 90% accuracy, even when the bone type is not first identified. Classification trees return accuracy rates greater than 98% for the human sample. These quantitative models provide statistical support to visual assessments and can be used for preliminary assessment of a bone’s forensic significance at a scene. The statistical models, however, could not classify species at acceptable rates. For species identification, a freely available web tool (OsteoID) was created from the study data, where users can filter photographs of potential bones/species using a few basic measurements and access 3D scans and additional resources to facilitate identification. OsteoID provides an important resource for forensic anthropologists lacking access to large comparative skeletal collections, as well as other disciplines where comparative osteological training is necessary.Although nonhuman remains constitute a significant portion of forensic anthropological casework, the potential use of bone metrics to assess the human origin and to classify species of skeletal remains has not been thoroughly investigated. This study aimed to assess the utility of quantitative methods in distinguishing human from nonhuman remains and present additional resources for species identification. Over 50,000 measurements were compiled from humans and 27 nonhuman (mostly North American) species. Decision trees developed from the long bone data can differentiate human from nonhuman remains with over 90% accuracy (>98% accuracy for the human sample), even if all long bones are pooled. Stepwise discriminant function results were slightly lower (>87.4% overall accuracy). The quantitative models can be used to support visual identifications or preliminarily assess forensic significance at scenes. For species classification, bone-specific discriminant functions returned accuracies between 77.7% and 89.1%, but classification results varied highly across species. From the study data, we developed a web tool, OsteoID, for users who can input measurements and be shown photographs of potential bones/species to aid in visual identification. OsteoID also includes supplementary images (e.g., 3D scans), creating an additional resource for forensic anthropologists and others involved in skeletal species identification and comparative osteology.

Bayesian discriminant function analysis based forecasting of crop yield in Kanpur district of Uttar Pradesh


 Discriminant function analysis technique using Bayesian approach has been attempted for wheat forecasting in Kanpur district of Uttar Pradesh, India both qualitatively and quantitatively. Crop yield data and weekly weather data on temperature (maximum and minimum), relative humidity (maximum and minimum), rainfall for 16 weeks of the crop cultivation have been used in the study. These data have been utilized for model fitting and validation. Crop years were divided into two and three groups based on the de-trended yield. Crop yield forecast models have been developed using posterior probabilities calculated through Bayesian approach in stepwise discriminant function analysis along with year as regressors for different weeks. Suitable strategy has been used to solve the problem of number of variables more than number of data points. Performance of the models obtained at different weeks was compared using Adjusted R2, PRESS (Predicted error sum of square), number of misclassifications. Forecasts were evaluated using RMSE (Root Mean Square Error) and MAPE (Mean absolute percentage error) of forecast. The result shows that the model based on three groups case perform better. The performance of the proposed Bayesian discriminant function analysis technique approach was better as compared to existing discriminant function analysis score based approach both qualitatively and quantitatively.

Sex estimation using radius in a Thai population.

The estimation of sex is an essential component of forensic osteological analyses, and the potential of an incomplete radius for sex determination of human remains is investigated. The present study was conducted on 200 left-right pairs of radial bone from a northern Thai population (100 males and 100 females). The most dimorphic single parameter was maximum head diameter (MDH) with accuracies 92.0% for the right side and 90.5% for the left side. At the distal part of radius, the distal end width of the radius (RDEW) was the best sex indicator, in which the sex classification accuracies were 91.5% and 89.0%, for the right and left sides, respectively. Stepwise discriminant function analysis was performed for all measurements and specified separately to the proximal and distal radius. The circumference of the radial neck, head-tuberosity length, MDH, and RDEW were selected for the stepwise procedure as these parameters produced the best correct classification results for both sides. The use of proximal radius for sex estimation was examined, with accuracies of 95.0% and 93.0% for the right and left sides, respectively. The sex classification functions for distal radius provided the accuracies of 92.5% and 89.5%, for the right and left sides, respectively. In summary, the fragments of radius indicated a high ability to estimate sex in the Northern Thai population.

Use of Morphometric Measurements of Photographs of a Sexually Dimorphic Bird to Determine Sex

This study investigated if morphological measurements made from digital photographs of banded adult Black Skimmers (Rynchops niger), using alphanumeric field readable leg bands as a scale reference, can be used to determine their sex. Black Skimmers are known for their extreme sexual dimorophism and make an excellent study subject. Measurements made in the field using calipers to determine length of the exposed culmen of skimmer chicks were significantly correlated to measurements made by three technicians using open-source software (ImageJ) measuring the culmen from photographs, with little variability among technicians. To determine sex, ImageJ was used to measure the culmen, bill depth at base, lower mandible and head + culmen lengths from photographs of 24 known sex adult skimmers (11 female, 13 male). Males were significantly larger than females for all four measurements and a stepwise Discriminant Function Analysis (DFA) using all 4 measurements retained exposed culmen and bill depth as the best predictor variables. This model correctly classified 100% of known sex males and females. Using the DFA equation, 40 additional banded skimmers were classified, and it was determined that 46 of the banded skimmers that were photographed as adults were male and 18 were female. Using a field readable band as a reference scale for other measurements may prove useful for research on other sexually dimorphic species that are banded and later photographed in the wild.

Sex estimation of the subadult ilium prior to acetabular fusion

Previous studies evaluating sexual dimorphism in subadult pelvic features present variable, and at times conflicting, conclusions. As a result, there is yet to be a consensus on whether the subadult pelvis can be used in sex estimation methods. This study aims to assess the forensic utility of ilium shape and greater sciatic notch morphology in sexing subadult pelves prior to acetabular fusion. A sample of 397modern U.S. individuals with unfused acetabula (i.e., tri-radiate cartilages) aged birth to 14years was queried from a larger sample of postmortem computed tomography scans. Elliptical Fourier analyses were performed on ilium and greater sciatic notch outlines and resultant PCs were evaluated for significant effects of sex and age. Greater sciatic notch metrics were also collected. Stepwise linear discriminant function analyses with leave-one-out cross-validation were performed on the PCs and metric variables. Analyses were performed on pooled samples, on age-specific cohort samples, and on samples that iteratively removed the youngest one-year cohort. Cross-validated correct classification rates ranged from 57% to 65% and no patterns were observed to support an appearance and/or consistent expression of sexually diagnostic traits. Based on the results, sex estimation using these features is not recommended in pelvic remains prior to acetabular fusion, although the sample sizes of individuals over 5years of age were limited in this study. Future studies should focus on the sexually diagnostic ability of pelvic traits in subadult samples post-fusion of the acetabulum.

Morphometric Sex Identification of Nestling and Free-Flying Tasmanian Wedge-Tailed Eagles (Aquila audax fleayi)

ABSTRACT The endangered Tasmanian Wedge-tailed Eagle (Aquila audax fleayi) is the focus of continued research and conservation efforts. A tool for accurate and efficient identification of the sex of individuals would be a valuable aid to research and management. However, plumages are monomorphic between the sexes, making sex identification difficult without molecular analyses. Our aim was to assess whether Tasmanian Wedge-tailed Eagles of different age classes could be sexed accurately using morphological measurements. We took measurements of 25 live late-stage eagle nestlings and 108 carcasses of free-flying birds found opportunistically throughout Tasmania. Sex of all individuals was confirmed via genetic analyses. Free-flying birds were larger than nestlings; thus, we used age-specific statistical tools to distinguish the sexes. For both nestlings and free-flying birds, females were significantly larger than males, but overlap between the sexes prevented accurate sex identification using any single measurement. We used stepwise linear discriminant function analyses to select morphometric measurements necessary for accurate sex identification. Free-flying birds could be sexed with 97.6% accuracy using a combination of measurements of the forearm length, tarsus width (i.e., lateromedial width), and hallux length. Late-stage nestlings (9–10 wk old) could be sexed with 95.4% accuracy using measurements of the hallux width (i.e., lateromedial width), hallux breadth (i.e., anteroposterior width of hallux), and tarsus breadth (i.e., anteroposterior width of the tarsometatarsus at the narrowest point). The discriminate functions we present also allow the identification of sex in cases where morphological sex identification may be in doubt and molecular analyses should be prioritized. These equations provide a valuable research tool for studies of sexual differences in behavior and causes of mortality of this endangered subspecies.

Hind Limb Bone Proportions Reveal Unexpected Morphofunctional Diversification in Xenarthrans

Divergence in forelimb morphology is often associated with functional habits exhibited within the Xenarthra, ranging from terrestrial-digging in armadillos to arboreal-suspension in sloths. We hypothesized that quantitative differences in hind limb form also will be predictive of the diverse lifestyles observed in this small clade. A total of 26 morphofunctional indices were calculated from 42 raw measurements of bone length/width/depth in a sample of N = 76 skeletal specimens (18 species). Index data for each species were categorized by substrate preference and use and then evaluated using a combination of stepwise Discriminant Function Analysis (DFA) and Principal Component Analysis (PCA) to determine significant osteological correlates (traits) among extant taxa. Additionally, character states of the morphometric data were inferred using a recent hypothesis of xenarthran phylogeny. DFA determined 14 distinct morphofunctional indices relating to femur robustness, hip/ankle/limb mechanical advantage, and foot and claw length as the most discriminating features. PCA clearly separated armadillos from sloths in morphospace based on overall robustness versus gracility, as well as proximal versus distal lengths of skeletal elements (including the claws), whereas these characteristics were intermediate in the hind limbs of anteaters and selected armadillos having either a larger greater trochanter or modified foot/claw proportions. Two-toed and three-toed sloths showed further separation from each other in morphospace primarily driven by proportions of their tibia and hind feet despite evidence of convergence for numerous functional traits. Moreover, the majority of the traits measured had significant phylogenetic signal and several of these indicated clear patterns of convergent and divergent evolution in xenarthrans by evaluation of their tip states. Our assessments expand functional interpretations of xenarthran limb form and identify potentially conserved and secondarily modified traits related to fossoriality across taxa, including in three-toed sloths, demonstrate possible morphological trade-offs between digging and climbing habits, and suggest derived traits adapted for arboreal lifestyle and suspensory function.

IMPROVEMENT IN KERATOCONUS DIAGNOSIS USING MORPHO-GEOMETRIC VARIABLES WITH RNN NETWORKS

There is an eye disease called Keratoconus (KC) which has potential to cause visual acuity loss; hence, it can be considered as disability due to its severity. There are some limitations in current method in detecting cornea region’s boarder edge. Primary objective for the paper need to identify the structural description of disease’ asymmetry with the help of Morpho-geometric parameters relates with the keratoconous eyes along by means of slight visual control. It also includes the application of Recurrent Neural Network (RNN) analysis which is sort of Neural Network in which previous step’s output are sent to present step as an input. In order to determine most prominent correlation, Stepwise Discriminant Function Analysis is used in analyzing output. The Prominent correlation was identified between thinnest point in the anterior deviation and thinnest point in the posterior deviations of minor keratoconic cases. MATLAB R2014 software is used to implement the framework and analyses of simulation results were performed.

Morphological Standard of Murrah Buffalo of India based on Multivariate Analysis of the Phenotypic Traits

Background: Morphometric measurements are important for the characterization of farm animal breeds and have become very useful in determining their morphological standards. Identification of animals based on breed standards are important for breed improvement and conservation programmes. Murrah, India’s world famous buffalo breed, is the highest milk producer and improver breed. Prevalence of Murrah grades in the vicinity of breeding tract of the Murrah warrants their differentiation. The objective of this study was to define the morphological standard of the Murrah buffalo and differentiate it from the Murrah grades. Methods: Fourteen body biometric traits of 258 she buffaloes were recorded from the core and peripheral breeding tract of the breed. In order to separate the animals into two groups, data were subjected to cluster analysis. Principal component analysis (PCA) and discriminant analysis were used respectively to describe the body conformation and identify the combination of independent traits that distinguished Murrah from grade Murrah.Result: Our study showed significant differences between the traits of Murrah and grade Murrah (p less than 0.05). The grade Murrah she buffaloes were smaller than the Murrah counterparts. PCA results showed that five factors explained 67.4% of total variance of studied morphometric traits in Murrah she buffaloes, whereas in Grade Murrah six components explained 72.7% of the total variance. The stepwise discriminant function derived with eight body biometric traits was able to discriminate Murrah and grade Murrah she buffaloes effectively. A total of 93.5% original grouped animals were classified correctly. The present work determines the morphometric standard of the Murrah buffalo through characterization and identification of latent factors of morphometric traits. Subsequent use of this information in marketing, breeding, management and conservation purposes can give significant productivity gains.

Phenotypic characterization of Raya cattle in northern Ethiopia.

Thirteen qualitative and six morphometric variables on a total of 651 adult cattle (76 oxen and 575 cows) from four purposively selected districts were recorded to characterize the cattle populations in and around the breeding tract of Raya cattle. General linear model, frequency, and multivariate analysis procedures of Statistical Analysis Software (SAS 9.0) were used to analyze the data by splitting and merging the sexes. Higher measurement values for oxen were recorded over the cows. Location affects the studied traits significantly. The cattle population from Habru district was significantly differentiated from Raya cattle. Among the districts of Raya cattle, lowest values for most of the linear measurements were observed in Kobo district. Majority of the Raya cattle possess upright, lyre-shaped horn, small, and erected hump placed at the cervical thoracic position, large dewlap, naval flap, and perpetual sheath sizes and dominantly dark red body color with uniform body color pattern. Stepwise discriminant function analysis reveals horn length, ear length, and height at wither were the first three most important morphometric variables used in discriminating the cattle populations. Canonical discrimination analysis showed that the first canonical structure explains majority (94.13%) of the total variation with eigenvalue of 2.07 and canonical correlation of 82.14%. Discriminant function analysis showed the classification of an average 61% of the studied animals into their respective districts. Pairwise Mahalanobis distances between populations from different districts were found to be highly significant. Habru cattle population relates distantly from Raya cattle except its short distance with Kobo district. The shortest distance was observed between Raya cattle of Alamata and Raya Azebo districts. In conclusion, cattle from Alamata, Raya Azebo, and Kobo districts can be categorized as Raya cattle, while strong similarities between the first two districts in showing the real characteristics and morphology of Raya cattle were also revealed.

Hissing of geese: caller identity encoded in a non-vocal acoustic signal.

Non-vocal, or unvoiced, signals surprisingly have received very little attention until recently especially when compared to other acoustic signals. Some sounds made by terrestrial vertebrates are produced not only by the larynx but also by the syrinx. Furthermore, some birds are known to produce several types of non-syrinx sounds. Besides mechanical sounds produced by feathers, bills and/or wings, sounds can be also produced by constriction, anywhere along the pathway from the lungs to the lips or nostrils (in mammals), or to the bill (in birds), resulting in turbulent, aerodynamic sounds. These noises often emulate whispering, snorting or hissing. Even though hissing sounds have been studied in mammals and reptiles, only a few studies have analyzed hissing sounds in birds. Presently, only the hissing of small, nesting passerines as a defense against their respective predators have been studied. We studied hissing in domestic goose. This bird represents a ground nesting non-passerine bird which frequently produces hissing out of the nest in comparison to passerines producing hissing during nesting in holes e.g., parids. Compared to vocally produced alarm calls, almost nothing is known about how non-vocal hissing sounds potentially encode information about a caller’s identity. Therefore, we aimed to test whether non-vocal air expirations can encode an individual’s identity similar to those sounds generated by the syrinx or the larynx. We analyzed 217 hissing sounds from 22 individual geese. We calculated the Potential for Individual Coding (PIC) comparing the coefficient of variation both within and among individuals. In addition, we conducted a series of 15 a stepwise discriminant function analysis (DFA) models. All 16 acoustic variables showed a higher coefficient of variation among individuals. Twelve DFA models revealed 51.2–54.4% classification result (cross-validated output) and all 15 models showed 60.8–68.2% classification output based on conventional DFA in comparison to a 4.5% success rate when classification by chance. This indicates the stability of the DFA results even when using different combinations of variables. Our findings showed that an individual’s identity could be encoded with respect to the energy distribution at the beginning of a signal and the lowest frequencies. Body weight did not influence an individual’s sound expression. Recognition of hissing mates in dangerous situations could increase the probability of their surviving via a more efficient anti-predator response.

Revision of the <em>Calotheca nigrotessellata</em> species group from southern Africa, with description of two new species (Coleoptera: Chrysomelidae, Galerucinae, Alticini)

Calotheca Heyden is a mostly sub-Saharan flea beetle genus, comprising twenty-seven species previously included in Blepharida Chevrolat. The examination of new material is revealing a high species richness, as there is high intraspecific variability. Calotheca luteomaculata sp. nov. from Zimbabwe and the Republic of South Africa, and C. luteotessellata sp. nov. from the Republic of South Africa are here described and attributed to the C. nigrotessellata (Baly) species group, mainly based on genitalic characters. Photographs of the main diagnostic characters are supplied, including the median lobe of the aedeagus and spermatheca. A forward stepwise discriminant function analysis, using morphometric variables, has been performed. It supports the attribution of the examined specimens to the three species here considered, thus adding characters useful for their identification. Information on geographical distribution and host plants are also provided.

Accuracies of discriminant function equations for sex estimation using long bones of upper extremities.

One of the scopes of practice of forensic anthropologists is the estimation of sex from skeletal remains. As a result, population-specific discriminant function equations have been developed from measurements of various bones of the human skeletons. Steyn, Patriquin (Forensic Sci Int 191 (1-3):113, 2009) noted that the lack of skeletal collections and data from most parts of the world has made this process impractical. Previous attempts to develop global discriminant function equations from measurements of the pelvis showed that population-specific equations are not necessary as equations derived from other populations yielded high sex estimation scores when applied to a different population. However, information on the suitability and applicability of generalised equations in sex estimation using long bones is still scarce. It is, therefore, the aim of this study to assess the accuracies of population-specific discriminant function equations derived from measurements of long bones of the upper limb of South African population groups. Data analysed in the current study were obtained from Mokoena, Billings, Bidmos, Mazengenya (Forensic Sci Int 278:404, 2017) and Mokoena, Billings, Gibbon, Bidmos, Mazengenya (Science & Justice 6(59):660-666, 2019) in which a total sample of 988 bones (humeri, radii, and ulnae) of South Africans of African descent (SAAD), South Africans of European descent (SAED) and Mixed Ancestry South Africans (MASA) were measured. Stepwise and direct discriminant function analyses were performed on the pooled data. Each function was used to estimate the sex of cases in each population group separately and average accuracies calculated. Thereafter, population-specific discriminant function equations were formulated for each population group and then applied to other population groups. The average accuracies of functions for pooled data ranged between 80.7 and 86.5%. The cross-validation average accuracies remained unchanged for most functions, confirming the validity of derived functions. A drop in average accuracies (0.8-5.3%) was observed when the functions were tested on a sample of SAAD while increased average accuracy was observed for the SAED and MASA (0.5-6.9%). When population-specific functions for a particular population group were applied to other groups, a wide range of a drop in average accuracies was observed (1.3 to 22.4%). This thereby confirms that population-specific equations should not be applied to other population groups. However, discriminant function equations from the pooled data of South Africans are accurate in the estimation of sex and efforts should be made towards the development and validation of such equations from as many bones of the human skeleton.

Changes in the Style and Contents of Abstracts from The Journal of Consulting and Clinical Psychology between the 1960s and the 2010s

This study was conducted to examine changes in the style and content of abstracts from the Journal of Consulting and Clinical Psychology across time. Characteristics examined were word commonness, word activation, word pleasantness, sentence length, abstract length, mentions of inferential statistics and mentions of drugs (both street drugs and pharmaceuticals). Abstracts (N=510) were downloaded from volumes published before the wide introduction of computers (1968-9) and from those published in more current years (2016-17). Scores for word pleasantness and word activation were assessed with the Dictionary of Affect in Language. Word commonness was scored in comparison to a corpus of everyday English, and sentence length and abstract length were measured in terms of number of words. There were several strong and significant differences between abstracts from the pre-computer era and those from the 21st century, including greater length, more mentions of inferential statistics and more mentions of drugs in the later time period. A stepwise discriminant function analysis was able to correctly predict the origin (early or pre-computer versus 21st century) of 98% of the abstracts on the basis of the characteristics measured (canonical correlation=.89).

Estimation of Sex from Patella Measurements in Sichuan Han Population Based on CT-Three-Dimensional Volume Reconstruction Technique

Objective To estimate sex based on patella measurements of Sichuan Han population by computed tomography three-dimensional volume reconstruction technique, and to explore the application value of patella in sex estimation. Methods CT three-dimensional volume reconstruction images of patella of 250 individuals were collected, the four measurement indicators including patellar length, patellar width, patellar thickness, and patellar volume were measured. The t-test was used to determine measurement indicators with sex differences. Fisher discriminant analysis was used to establish the sex discriminant function and the prediction accuracy was calculated by leave-one-out cross validation. Results The sex differences of the four measurement indicators had a statistical significance （P<0.05）. The accuracy rate of the univariate discriminant function established by the patellar length was the highest （82.0%）. The accuracy rates of the all indicators discriminant function and the stepwise discriminant function were 80.4% and 81.6%, respectively. Conclusion It is feasible and accurate to estimate sex of Sichuan Han population by patella measurements with CT three-dimensional volume reconstruction technique. The method may be used as an alternative for sex estimation of Sichuan Han population when other bones with higher accuracy are not available.

Estimation of sex from the metacarpal dimensions at the nutrient foramen in white South Africans

ABSTRACT Sex estimation is important in both forensic and archaeological cases and requires a variety of bones and measurements to obtain accurate estimates. Discriminant function analysis equations on postcranial elements are associated with population specificity, hence the need to generate equations for each population group. The current study examined the utility of the measurements around the nutrient foramen of the metacarpals for sex estimation from white South Africans. The study utilized 520 left metacarpals from 104 adult skeletons of white South Africans of known sex (53 males, 51 females) and age at death (range 21 to 65 years) obtained from the Raymond A. Dart Collection of Human Skeletons at the University of the Witwatersrand. Measurements that were subjected to stepwise and direct discriminant function analyses include total length, distance from proximal end to nutrient foramina, circumference, palmar-dorsal diameter, and mediolateral diameter at the level of the nutrient foramen. Combinations of breadth measurements of the first and second metacarpals produced high sex estimation scores ranging from 82% to 91% (stepwise discriminant function analysis) and 82–94% (direct discriminant function analysis) indicating that the dimensions around the nutrient foramen of the metacarpals are useful in sex estimation and can be used in fragmentary bones.

High-level individuality in vocalizations of a well-known avian brood parasite: Asian koel (Eudynamys scolopacea L.)

ABSTRACT The Asian koel (Eudynamys scolopacea) is a well-known brood parasitic bird that visits Pakistan every summer from India. This species produces at least five loud call types that are presumed to be used in territorial and mating behaviour. We noticed vocal differences among individuals in the wild and hypothesised that Asian koels produce individually distinct vocalizations. To test this, we recorded type 1 cooee calls, coe calls, type 1 coegh calls, type 2 coegh call and wurroo calls from 46 adult birds in the wild, and measured 15 different acoustic parameters, both spectral and temporal, for each vocalization type. We also measured the Potential of Individual Coding (PIC). Parameters having PIC values ≥1.1 were further analysed through stepwise cross-validated discriminant function analysis (DFA). The DFA accurately categorised 86.5% of the type 1 cooee calls, 95.7% of coe calls, 91.5% of the type 1 coegh calls, 82.2% of type 2 coegh calls and 83.3% of wurroo calls to the individuals from which these calls were recorded. Thus, consistent with our hypothesis, our results indicate that Asian koels produce individually distinct calls.

Sex estimation of the scapula using 3D imaging in a modern Turkish population

Sex estimation is one of the most important elements of forensic identification of unknown human individuals. The scapula is a potential source of information for sex assessment, even in cases in which it is the only item recovered in a forensic context. For this purpose, computed tomography (CT) images of 152 patients with an age range of 22–80 years were analyzed and 8 variables were manually measured on the segmented 3D scapula imaging. The results showed that all 8 variables were highly dimorphic, with rates of correct sex estimation between 74% and 92% for the direct and 96% for the stepwise discriminant function equations. The best overall estimation rate was achieved by measuring the glenoid cavity breadth (92.1% accuracy), followed by maximum scapular height and maximum length of the spine (90.1% accuracy). This study was the initial study of scapular sexual dimorphism in a Turkish population. Data obtained from this study show that the CT scan analysis of the scapula was useful for sex estimation in a modern Turkish population. Whenever there is difficulty accessing bone collections, as in countries such as Turkey, CT scans could provide useful data for sex estimation.