Canonical Variate Analysis Research Articles

Variations in Otolith and Scale Shape of the Invasive Round Goby Neogobius melanostomus Populations from Different Habitats of the Sava River Basin, Croatia

Abstract Round goby Neogobius melanostomus is one of the three invasive Ponto-Caspian gobies found in the Sava River basin in Croatia. It has a negative effect on the native ecosystems due to its high invasive potential that enables its rapid spread upstream in inland watercourses. The objective of this study was to determine the differences in sagittal otolith and scale shape of the frontal and established populations of N. melanostomus in two different habitat types. At two sampling sites in the main course of the Sava (Babina Greda, Slavonski Brod) and in a modified habitat (Sava-Odra canal), 20 individuals of N. melanostomus were collected and analysed. The geometric morphometric method was used together with Procrustes analysis of variance, canonical variate analysis and discriminant function analysis to analyse the otolith and scale shape. Significant differences in both otolith and scale shapes were found between settled (Babina Greda) and frontal (Slavonski Brod) populations from the main course of the Sava River. The main differences were the wider anterior part of the scales and a more pronounced open indentation on the otolith of the Babina Greda population. The settled population in the Sava-Odra canal was significantly different in otolith shape from the Babina Greda population but not from the Slavonski Brod population, suggesting that the upstream migration consisted of individuals with specific phenotype and genotype. Otoliths generally expressed greater shape variability than scales and thus may be more useful for differentiating between closely related populations on a finer scale. The results of this study suggest that the shape of otoliths and scales can be used to distinguish between closely related populations of N. melanostomus from different habitats but more comprehensive studies are needed due to the small number of samples.

Form function of sulcus acusticus of the sagittal otolith in seven Sciaenidae (Acanthuriformes) species using geometric morphometrics (southwestern Atlantic).

The morphology of otoliths determines the function they perform, and it is influenced by genetic and environmental factors. Knowing those relationships is necessary to understand the role of hearing in fish. The objectives of this work were: exploring the shape of the sulcus of the sagittal otolith in seven species of Sciaenidae, in relation to sound production, and analyzing whether the shape and size of the sulcus can be used as a phylogenetic character. For this purpose, geometric morphometry analysis was carried out using landmarks data. It was found that there is an influence of size on the shape of the sulcus, and significant differences were found between the shapes of the sulcus (permutational multivariate analysis of variance). Three general shapes of the sulcus were identified (using principal component analysis, canonical variate analysis, and clustering): (1) in species that produce sounds at dominant frequencies <350 Hz, the deformation of the sulcus showed a tendency towards circularity of the ostium; (2) in those species that produce sounds at frequencies >350 Hz, the ostium showed a flattened ovoid shape, and the cauda increased its length; (3) the species that do not produce sounds, did not show any modifications, relative to the form of consensus. Despite finding sister species that presented similar sulcus shapes in the phylogeny, the results did not confirm that this can be used as a phylogenetic character. This work discusses whether the combined effects of phylogenetic legacy and natural functional selection have led to convergent evolution for the sulcus form. The differences presented by the sulcus of species that occupy the same clade, could indicate that there is a displacement of characters. The sagittal otolith and the sensory macula associated with the sulcus acusticus are highly plastic structures that are subject to strong evolutionary pressure in relation to environmental and behavioral factors, resulting in great variability in shapes that can be associated with a specific character. The variation in the shape of the sulcus would allow the analysed species to coexist in the same coastal soundscapes, without losing their particular hearing needs, even in case of overlapping their spatial and temporal distribution areas.

Chemometric Analysis-Based Sustainable Use of Different Current Baking Wheat Lots from Romania and Hungary

Wheat is the most important raw material for bakery industries. Real-time grain quality assessment could increase bakery product quality and baking efficiency. The quality assessment of wheat grains can be conducted using modern and non-invasive techniques based on near-infrared spectrophotometry (NIRS) methods for the assessment of gluten content (WetGL), protein content, Zeleny index (ZelenyIdx), grain humidity (Ur), etc. The topic covered in the study is of current interest, is a part of sustainable research, and involves aspects of food quality, one of the concerns addressed by the University of Oradea’s Department of Food Engineering. The present study was carried out in 2020 on eleven wheat lots from Romania and Hungary. Following the NIRS analyses, the results show varied quality for the Romanian and Hungarians wheat lots. The Romanian variety Crisana recorded the highest values for quality parameters, being similar to the Hungarian variety Bekes from Hajdu Bihar County. The statistical analysis was carried out using multivariate analysis (multivariate analysis of variance (MANOVA), canonical variate analysis (CVA) and hierarchical cluster analysis (HCA)), which highlighted which of the batches of wheat grains can be mixed to obtain a raw material of high quality for the bakery industry.

Recursive ensemble canonical variate analysis for online incipient fault detection in dynamic processes

Data-driven fault detection has made significant advancements. However, detecting incipient faults is still a challenging problem for traditional data-driven methods, because it has low amplitude and is easily masked by measurement noise. In this paper, we propose an approach for detecting incipient faults named recursive ensemble canonical variate analysis (RECVA) for dynamic processes. First, inspired by ensemble learning, multiple CVA-based incipient fault models are obtained based on sampling from the training data set using bootstrap. It generates two matrices based on the principal component and the residual subspace. Then, two sensitive detection metrics are created using the maximum eigenvalue of a one-step sliding window over each row of the two aforementioned matrices. Based on the first-order perturbation (FOP) theory, the eigenvalue can be recursively updated. Utilizing the two detection metrics, RECVA can effectively detect incipient faults, which cannot be detected by conventional statistics. The effectiveness of RECVA is fully validated with the incipient fault data collected from the continuous stirred tank heater (CSTH) and the Tennessee Eastman process (TEP) simulation benchmark. Compared with traditional PCA, CVA, and other incipient fault detection methods based on divergence, simulation demonstrated that incipient faults can be effectively detected at an early stage, which is very important for avoiding serious failures in the industrial processes, resulting in economic losses and casualties.

Exploring genotypic variability and interrelationships among growth, yield, and quality characteristics in diverse tomato genotypes

Tomato is the most consumed vegetable crop worldwide, with excellent beneficial health properties and high content of vitamins, minerals, carotenoids, total antioxidants, and phenolic compounds. Hence, improving its genotypes is crucial to sustain its production and ensure food security, principally under the fast-growing worldwide population and abrupt global climate change. The present study aimed to explore the genotypic variability associated with specific characteristics in twenty-five diverse tomato genotypes. In addition, the relationships between growth, yield, and quality traits using both univariate (correlation coefficient, path analysis) and multivariate (principal component, principal coordinates, canonical variate) analysis methods were explored. The results indicated that the evaluated genotypes possessed highly significant variation. This is appropriate for future hybridization through tomato breeding programs. All evaluated genotypes demonstrated considerable potential to develop strong hybrid vigour for growth, yield, and quality characteristics. In particular, the genotypes LS009, LS011, and LS014 could be considered promising, high-yielding, and resistant to yellow leaf curl virus infestation (YLCV) disease parents for future breeding schemes. The number of fruits per plant, fruit diameter, and fruit weight proved strong positive relationships with fruit yield. Accordingly, these characteristics demonstrate their importance in improving fruit yield and could be exploited as indirect criteria for selecting high-yielding tomato genotypes through breeding programs.

Comparing shell size and shape with canonical variate analysis of sympatric Biomphalaria species within Lake Albert and Lake Victoria, Uganda

Abstract The Great African Lakes in Uganda (Lake Albert and Lake Victoria) are known habitats to several sympatric species of Biomphalaria, intermediate snail hosts of the human parasite Schistosoma mansoni. However, accurate identification of snails by morphology alone can be problematic, highlighting a need for robust, on-site identification methods, since only certain species have important roles in parasite transmission. This study investigates the conchological variation within Biomphalaria species collected from these two Great East African Lakes. We compared the shell morphologies of Biomphalaria species using landmark-based morphometric techniques and were able to distinguish Biomphalaria species through canonical variate analysis (CVA) of the apical and apertural shell angles. After identification with molecular methods, three Biomphalaria species (B. pfeifferi, B. stanleyi, and B. sudanica), with heterogenous occurrences along the shoreline, were identified at Lake Albert that could be differentiated from one another using CVA of apical and apertural datasets; by contrast, a single Biomphalaria species was identified at Lake Victoria (B. choanomphala). When snails from both lakes were compared together, CVA was able to differentiate all four species using the apical dataset but not the apertural dataset. Of the Biomphalaria species identified, ecological phenotypic variation was only found in B. choanomphala, which exhibited two distinct ecological morphotypes. Furthermore, these two B. choanomphala morphotypes from Lake Victoria overlapped upon analysis of the apical dataset, yet were clearly separated upon analysis of the apertural dataset. Our study demonstrates that landmark-based morphometrics could play a future role in distinguishing sympatric Biomphalaria species in Uganda.

Effect of pony morphology and hay feeding methods on back and neck postures.

The application of hay feeding devices, such as the use of hay nets or slow feeders, can help with the management of weight in ponies; however, there is still a lack of knowledge regarding their effect on equine posture. Therefore, the aim of the study was to assess the effect of different feeding devices on the posture of ponies using morphometric analysis. Two different breed types, Shetland type (SH, n = 5) versus Welsh Cob type (WC, n = 4), were fed the same forage in four different ways: on the ground (G), using a fully filled haynet (HF), using a partially filled haynet (HL)and using a slow-feeder hay box (HB). Video recordings were obtained and then geometric morphometric analysis was applied. Breed morphology was confirmed by body morphometric measurements. Data were analysed statistically usingone-way ANOVA, canonical variate analysis (CVA), principal component analysis (PCA), partial least-squares (PLS) analysis andmultivariate analysis of variance (MANOVA). Moreover, a mixed model was performed to study differences in mandibular angle. SH and WC ponies were shown to have significantly different body morphometric measurements. The geometric morphometric analysis results showed that ponies arch their back and modify their neck shape differently according to the feeding method and their morphological group. For the neck, the SH and WC ponies adapted similarly to the use of small-holed hay nets, but their posture varied when feeding from the ground or hay box. The back postures consistently differed according to the breed type and feeding method. The mandibular angle for both breed types was reduced with all the feeding devices compared to feeding from the ground. Further studies are needed to evaluate the long-term effects of slow-feeding devices on posture and mandibular angle, taking into consideration animals with different morphologies.

Phase partition and online monitoring for batch processes based on Harris hawks optimization

Most industrial batch processes exhibit significantly different characteristics at different manufacturing steps, and it is advantageous to partition batch processes reasonably and establish phase models separately for online monitoring. In the present work, a novel phase partition method is developed based on Harris hawks optimization (HHO) with hard sequentiality constraint, which seeks for the optimal phase partition results under the specific target phase number in inner loop and automatically determines the optimal phase number in outer loop by making a trade-off between modeling complexity and partition performance. First, a new definition of the sum of quadratic error (SQE) is designed as the fitness function to evaluate the within-phase compactness, which makes the time-slice matrices with similar process variable correlations stay in the same phase. Then, an optimization refinement scheme (ORS) is developed to find the potential local minimum of the SQE by inspecting and reallocating the phase-adjacent samples. Afterwards, the percentage of performance improvement indicator (PPII) is proposed to determine the optimal phase numbers by quantifying the improvement of minimum SQE. For each subphase, canonical variate analysis (CVA) is performed to build statistical models for dynamic process monitoring. The effectiveness of the proposed method is illustrated by a numerical example with some outliers and an injection molding process.

Dynamic State-Space Modeling With Factorial Memories in Temporal Dominance of Sensations, Emotions and Temporal Liking

There are few mathematical models that describe how human perceptual and affective responses evolve with time. We developed a state-space model of the interrelationships based on time-evolving perceptual and affective responses acquired by the temporal dominance (TD) method. We defined and computed the state variables that endow the system with memory using canonical variate analysis. Furthermore, we determined the model parameters on the basis of a cross-validation approach such that the observed and estimated changes in the affective responses are highly correlated. We applied this method to the TD curves of responses to eating strawberries and plum pickles, reported in our previous work. The model describes what happens during food intake in terms of a few state variables that summarize a large number of observable responses reductively, thus helping to make the perceptual and affective dynamics understandable.

Fault Detection for Nonlinear Dynamic Systems With Consideration of Modeling Errors: A Data-Driven Approach.

This article is concerned with data-driven realization of fault detection (FD) for nonlinear dynamic systems. In order to identify and parameterize nonlinear Hammerstein models using dynamic input and output data, a stacked neural network-aided canonical variate analysis (SNNCVA) method is proposed, based on which a data-driven residual generator is formed. Then, the threshold used for FD purposes is obtained via quantiles-based learning, where both estimation errors and approximation errors are considered. Compared with the existing work, the main novelties of this study include: 1) SNNCVA provides a new parameterization strategy for nonlinear Hammerstein systems by utilizing input and output data only; 2) the associated residual generator can ensure FD performance where both the system model and its nonlinearity are unknown; and 3) with consideration of modeling-induced errors, the quantiles are invoked and used to provide a reliable FD threshold in situations where only limited samples are available. Studies on a nonlinear hot rolling mill process demonstrate the effectiveness of the proposed method.

Assessment of wing geometric morphometrics of urban Culex quinquefasciatus (Diptera: Culicidae) populations

Culex quinquefasciatus is a cosmopolitan species distributed throughout tropical and subtropical areas of the world. The species is of great epidemiological importance as it is responsible for vectoring the causative agent of lymphatic filariasis and several arboviruses, including West Nile virus. Wing geometric morphometrics has been widely used to assess phenotypic variations in mosquito species. Here, we hypothesize that Cx. quinquefasciatus populations in urban parks in the city of São Paulo, Brazil, have been subjected to anthropogenic selective pressures that are responsible for driving their ecology and behavior. Mosquitoes were collected by CDC traps in five municipal parks in the city of São Paulo. Eighteen anatomical landmark coordinates on each female right wing were digitized. Canonical variate analysis, wireframe graphs, cross-validated reclassification tests and the neighbor-joining method were used to assess phenotypical dissimilarity in wing shape between populations. Centroid size was calculated to assess differences in wing size between populations, which can result from different environmental conditions during immature mosquito development. Moderately heterogeneous wing shape and wing size patterns were found in the populations analyzed, indicating that selective pressures in the urban environment are affecting the wing patterns of Cx. quinquefasciatus populations in the city of São Paulo, Brazil.

Differential impacts of ionizing radiation on a sexually dimorphic trait in male and female Acheta domesticus

Purpose In many Orthopteran species, including crickets, forewings exhibit substantial sexual dimorphism driven by sexual selection. In the cricket, Acheta domesticus, females are the ‘choosy’ sex and males exhibit multiple sexual signals to attract and successfully mate. Male forewings have highly specialized structures critical for acoustic signaling and mating. In contrast, female forewings currently serve no known purpose in this flightless species. Forewings also differ morphologically with male forewings containing complex acoustic producing and resonating regions and females lacking any defined structures. Due to their importance to mating as well as their structural complexity, impacts of environmental stress that target cricket forewing development may therefore have more severe consequences in males than females. Here, we investigate the sensitivity of a sexually dimorphic trait, forewing morphology, to an early life environmental stressor. Materials and Methods We applied ionizing radiation (0-–27.8 Gy) as a stressor as dose can be precisely applied as well as its relevance in both environmental contamination and use in the Sterile Insect Technique. Results A canonical variate analysis indicated that wing shape was significantly altered in males at all doses; .58 Gy, 2.3 Gy, 4.6 Gy, 16.2 Gy, and 23.2 Gy. In females, shape was significantly altered at 27.8 Gy and 23.2 Gy groups and to a lesser extent at .58 Gy and 16.2 Gy. Linear regression analysis of centroid size indicated a dose dependent decline in wing size in both sexes, with males exhibiting more decline. Fluctuating asymmetry, a measure of environmental sensitivity, revealed that males were more sensitive to shape changes due to stress than females. This difference in sensitivity is likely due to the complexity of male forewings. Conclusion These results expand understanding of sex dimorphism in stress responses and sensitivity to ionizing radiation.

Age estimation from mandibles in Malay: A 2D geometric morphometric analysis

ObjectivesIn this study, the sizes and forms of mandibles in various age groups of the Malay population were measured and compared. MethodsGeometric morphometric (GM) analysis of mandibles from 400 dental panoramic tomography (DPT) specimens was conducted. The MorphoJ program was used to perform generalized Procrustes analysis (GPA), Procrustes ANOVA, principal component analysis (PCA), discriminant function analysis (DFA), and canonical variate analysis (CVA). In the tpsDig2 program, the 27 landmarks were applied to the DPT radiographs. Variations in mandibular size and form were categorized into four age groups: group 1 (15–24 years), group 2 (25–34 years), group 3 (35–44 years), and group 4 (45–54 years). ResultsThe diversity in mandibular shape among the first eight principal components was 81%. Procrustes ANOVA revealed significant shape differences (P < 0.001) among age groups. Mahalanobis distances indicated substantial differences among all age groups; group 1 and group 4 scored highest, at 2.114. The ranges for the cross-validation and discriminant function tests were 90–72% and 81–49%, respectively. ConclusionGM analysis through radiography is a simple, non-invasive, and non-destructive method of estimating age by using the mandible. GM analysis is unique because it can visualize the changes in mandible shape among age groups. This method should aid in age identification in forensic odontology investigations.

Portable Instruments Based on NIR Sensors and Multivariate Statistical Methods for a Semiautomatic Quality Control of Textiles

Near-infrared (NIR) spectroscopy is a widely used technique for determining the composition of textile fibers. This paper analyzes the possibility of using low-cost portable NIR sensors based on InGaAs PIN photodiode array detectors to acquire the NIR spectra of textile samples. The NIR spectra are then processed by applying a sequential application of multivariate statistical methods (principal component analysis, canonical variate analysis, and the k-nearest neighbor classifier) to classify the textile samples based on their composition. This paper tries to solve a real problem faced by a knitwear manufacturer, which arose because different pieces of the same garment were made with “identical” acrylic yarns from two suppliers. The sweaters had a composition of 50% acrylic, 45% wool, and 5% viscose. The problem occurred after the garments were dyed, where different shades were observed due to the different origins of the acrylic yarns. This is a challenging real-world problem for two reasons. First, there is the need to differentiate between acrylic yarns of different origins, which experts say cannot be visually distinguished before garments are dyed. Second, measurements are made in the field using portable NIR sensors rather than in a controlled laboratory using sophisticated and expensive benchtop NIR spectrometers. The experimental results obtained with the portable sensors achieved a classification accuracy of 95%, slightly lower than the 100% obtained with the high-performance laboratory benchtop NIR spectrometer. The results presented in this paper show that portable NIR sensors combined with appropriate multivariate statistical classification methods can be effectively used for on-site textile quality control.

60 Bite and mouth shape variations assessment during different slow-feeding management in ponies: A geometric morphometric evaluation

Previous studies have highlighted the influence of different slow-feeding devices on behavior, intake rate and body postures of stabled equines. There is still, however, a lack of knowledge on how feeding devices change the biting mechanism and ultimately chewing behavior. The aim of our study was to evaluate the variation of bite and mouth shape in ponies fed the same forage by different feeding methods. Nine ponies belonging to 2 breed types - Shetland (n = 5, SH) and Welsh Cob (n = 4, WC) types - were used (mean ± SD: 12 ± 4 years and a BCS:7.6 ± 0.7/9). Breed type designation was assigned according to owner information and body morphometric measurements. A first cut meadow hay was offered to SH and WC ponies in 4 ways following a Latin square design: 3 kg of hay fed on the ground (G); or a small-holed hay net (3.5 × 3.5 cm holes) filled with 3 kg (Haynet full fill, HNF) or 1 kg (Haynet light fill, HNL) of hay; or a newly developed slow feeder (Haybox, HB) containing 3 kg of hay. The 2 hay nets were optimally placed, according to previous work, with the hay net base at the same height as the pony's elbow. Each pony was video recorded 3 times per feeding method and from the video at least 10 still frames/pony/feeding method were selected. A specific point configuration comprising 9 landmarks was developed and geometric morphometrics was applied to study variation in bite and mouthshape. Data were statistically analyzed using principal component analysis (PCA) and canonical variate analysis (CVA). When ponies were fed on the ground (G), the CVA showed the lowest variation (35.7%) in the bite and mouth shape, suggesting a similar biting mechanism despite the morphometric differences between the 2 breed types. In contrast, the use of the slow feeding devices – HB, HNF, HNL – showed higher values of shape variation between the breeds. Interestingly, the highest variation was reported when using the HNL (83.2%), followed by the HB (78.3%) and by the HNF (76.7%), highlighting that each feeding device made the animal alter their biting mechanism. These results were confirmed visually through PCA analysis, demonstrating that the features of the feeding device influenced the mouth shape. Our study suggested that the use of slow-feeding devices, of different size and capacity, not only can alter the intake rate of ponies but can also affect their way of feeding in terms of bite and mouth shape regardless of their morphology. This should be taken into account in further studies on slow feeding management, with the aim to fully understand the effects of different devices on feed intake mechanics.

Comparison of traditional and geometric morphometrics using Lake Huron ciscoes of the Coregonus artedi complex

AbstractObjectiveHere we determine how traditional morphometrics (TM) compares with geometric morphometrics (GM) in discriminating among morphologies of four forms of ciscoes of the Coregonus artedi complex collected from Lake Huron.MethodsOne of the forms comprised two groups of the same deepwater cisco separated by capture depth, whereas the other three forms were shallow‐water ciscoes.ResultOur three groups of shallow‐water ciscoes were better separated (3% vs. 19% overlap) in principle component analysis (PCA) with TM data than with GM data incorporating semilandmarks (evenly spaced nonhomologous landmarks used to bridge between widely separated homologous landmarks). Our two deepwater cisco groups, comprising a putatively single form collected from different depths, separated more in PCAs with GM data (33% overlap) than in PCAs with TM data (66% overlap), an anomaly caused by greater decompression of the swim bladder and deformation of the body wall in the group captured at greater depths. Separation of the two deepwater cisco groups captured at different depths was not affected by the removal of semilandmarks. Assignment of forms using canonical variate analysis accurately assigned 86% of individuals using TM data, 98% of individuals using GM data incorporating semilandmarks, and 100% of individuals using GM data without semilandmarks. However, we considered assignments from the same form of deepwater cisco into separate groups as misassignments resulting from different capture depths, which reduced the accuracy of assignments with GM data incorporating semilandmarks to 66%.ConclusionOur study implies that TM will continue to have an important role in morphological discrimination within Coregonus and other fishes similarly shaped.

Statistical Multivariate Methods for the Selection of High-Yielding Rapeseed Lines with Varied Seed Coat Color

A crucial aim for rapeseed breeders is increasing the seed yield through improving yield- and silique-related traits. In this research, traits including the number of seeds per silique, silique length, silique width, and thousand-seed weight combined with seed coat color were investigated. Yellow-seeded lines of oilseed rape have a thinner seed coat, lower fiber content, and higher protein and oil content than traditional varieties. Hybrids of yellow- and black-seeded Brassica napus, which combine the advantages of both types of seeds, are tested for their suitability in breeding. Therefore, the aim of this study was to assess a population of 78 doubled haploid lines with different seed coat colors to select genotypes connecting a light color of seeds with good yielding characteristics. Multivariate methods such as analysis of variance, correlation analysis, regression analysis, canonical variate analysis, Mahalanobis distances, and estimation of gene effects were used. The results showed that all tested genotypes were significantly different regarding all five studied traits. The multidimensional analyses gave an accurate overview of the relationship between the examined features. The color and weight of seeds were considered the most important for breeding rapeseed with better seed properties. Although a negative correlation between these two characteristics occurs quite commonly, it was not present in our plant material, which allowed us to select lines with a-light seed color and high thousand-seed weight, which is a significant achievement. As a result, two doubled haploid lines were chosen as valuable breeding material for creating oilseed rape varieties with improved biochemical characteristics of seeds.

Morphological variation of African snakehead (Parachanna obscura) populations along climate and habitat gradients in Côte d’Ivoire, West Africa

Intraspecific morphological variation may reflect phenotypic plasticity or adaptive divergence. While adaptive shape divergence may occur more likely among isolated populations with reduced gene flow, phenotypic plasticity may reflect morphological responses to heterogeneous environments, even in spatially connected populations. We evaluated both processes while examining morphological variations among seven wild populations of snakehead fish (Parachanna obscura) along climate and habitat gradients in Côte d’Ivoire, West Africa. Morphological variations were studied by multivariate canonical variate analysis (CVA) as based on geometric morphometrics of 15 fish body landmarks. Correlations between shape variations among populations and climate and habitat characteristics and between morphological and geographic distances were calculated. We found significant morphological variations among the seven populations. The variations in fish shape were concentrated on landmarks related to swimming and feeding, suggesting a contribution of environmental variation to morphological differentiation. However, we did not detect significant effects of climate and habitat variables on fish shape. The trend between geographical and morphological distances was likewise not significant. Therefore, a mechanistic understanding of the factors causing shape variation among P. obscura populations in West Africa could not yet be achieved.

Morphometric analysis of tooth morphology among different malocclusion groups in a hispanic population

BackgroundThere have been reports of unique dental morphological features amongst Latin American and Hispanic populations, and this might invalidate the use of current orthodontic diagnostic tools within this population. There are no tooth size/tooth ratio normative standards for the Hispanic population, despite overwhelming evidence about differences in tooth size between racial groups.ObjectiveThis study aimed to determine whether there are significant differences in 3-D tooth shape between patients with Angle Class I, Class II, and Class III dental malocclusion in the Hispanic population.MethodologyOrthodontic study models representing Hispanic orthodontic patients with Angle Class I, II, and III dental malocclusions scanned using an intra-oral scanner. The scanned models were digitized and transferred to a geometric morphometric system. Tooth size shape were determined, quantified, and visualized using contemporary geometric morphometric computational tools using MorphoJ software. General Procrustes Analysis (GPA) and canonical variates analysis (CVA) used to delineate the features of shape that are unique to each group.ResultThe study revealed differences in tooth shape between the different dental malocclusion groups on all twenty-eight teeth that were studied; the pattern of shape differences varied between the teeth and the dental malocclusions. The MANOVA test criteria, F approximations, and P-values show that shape in all the groups was significantly different < 0.05.ConclusionThis study revealed differences in tooth shape between the different dental malocclusions on all teeth, and the pattern of shape differences varied between the different dental malocclusions group.

A reassessment of the distinctiveness of dryopithecine genera from the Iberian Miocene based on enamel-dentine junction geometric morphometric analyses.

A vast diversity of catarrhines primates has been uncovered in the Middle to Late Miocene (12.5-9.6Ma) of the Vallès-Penedès Basin (northeastern Spain), including several hominid species (Pierolapithecus catalaunicus, Anoiapithecus brevirostris, Dryopithecus fontani, Hispanopithecus laietanus, and Hispanopithecus crusafonti) plus some remains attributed to 'Sivapithecus' occidentalis (of uncertain taxonomic validity). However, Pierolapithecus and Anoiapithecus have also been considered junior synonyms of Dryopithecus by some authors, which entail a lower generic diversity and an inflated intrageneric variation of the latter genus. Since the distinction of these taxa partly relies on dental features, the detailed and quantitative analysis of tooth shape might help disentangling the taxonomic diversity of these Miocene hominids. Using diffeomorphic surface matching and three-dimensional geometric morphometrics, we investigate the enamel-dentine junction shape (which is a reliable taxonomic proxy) of these Miocene hominids, with the aim of investigating their degree of intra- and intergeneric variation compared with that of extant great ape genera. We conducted statistical analyses, including between-group principal component analyses, canonical variate analyses, and permutation tests, to investigate whether the individual and combined (i.e., Dryopithecus s.l.) variation of the extinct genera exceeds that of the extant great apes. Our results indicate that Pierolapithecus, Anoiapithecus, Dryopithecus, and Hispanopithecus show morphological differences of enamel-dentine junction shape relative to the extant great apes that are consistent with their attribution to different genera. Specifically, the variation displayed by the Middle Miocene taxa combined exceeds that of extant great ape genera, thus undermining the single-genus hypothesis. 'Sivapithecus' occidentalis specimens fall close to Dryopithecus but in the absence of well-preserved comparable teeth for Pierolapithecus and Anoiapithecus, their taxonomic attribution remains uncertain. Among the Hispanopithecus sample, IPS1802 from Can Llobateres stands out and might either be an outlier in terms of morphology, or represent another dryopithecine taxon.