Indicator Of Sexual Dimorphism Research Articles

Maxillary first premolar shape (and not size) as an indicator of sexual dimorphism: A 2D geomorphometric study.

The primary aim of the study is to evaluate the morphological form of the maxillary first premolar using 2D geomorphometry and evaluate the sexually dimorphic characteristics. The present study was carried out on standardized photographs of right Maxillary first premolar from 120 dental casts (60 male and 60 females). Twenty landmarks (based on geometric and anatomic evidence) were marked on the tooth using TPSdig software and analysed using Morpho J applying procrustes analysis and discriminant function analysis. The results showed similar centroid sizes between gender (p = 0.541). Procrustes ANOVA for shape analysis showed a greater dimorphism between sexs (f value of 1.35; p value=0.0793). Discriminant function analysis based on the procrustes coordinates showed an overall accuracy of 74.2 % in classifying sex based on the landmark coordinates with correct classification of 48/60 (80.00%) females and 41/60 (68.33) males. Shape of the tooth can be measured objectively using geometric morphometric methods which can be utilized to identify the sex of an individual. The enamel is derived from ectoderm and once formed does not change during the life. The tooth's structure and shape are determined by the sex chromosomes, which is well represented as sexual dimorphism. The study evaluates the occlusal and contact area morphology of premolars. These are important parameters considered during restorative treatment, functional rehabilitation and forensic investigations.

Studying A Number of Reproductive Values in Sexual Somatotypes in Women Athletics Doing Weightlifting and Powerlifting

The article presents materials concerning the issue of studying a number of reproductive values (using the example of the menstrual cycle) in female athletes involved in weightlifting and powerlifting. The purpose of the article is to present the results obtained, with identified changes in a number of morphological and medical-biological reproductive health of female athletes. Data on indicators of sexual dimorphism in each of the somatotypes in the studied groups are presented. The identified variants of menstrual cycle disorders in female athletes and the identified manifestations of hyperandrogenism in a number of female athletes in both groups are described in detail. The established relationship between intense physical and psycho-emotional stress and identified disorders in a number of reproductive health indicators in female athletes of both groups is indicated.

Maxillary first premolar shape (and not size) as an indicator of sexual dimorphism: A 2D geomorphometric study

Introduction The primary aim of the study is to evaluate the morphological form of the maxillary first premolar using 2D geomorphometry and evaluate the sexually dimorphic characteristics. Methods The present study was carried out on standardized photographs of right Maxillary first premolar from 55 dental casts (33 male and 22 females). Nineteen landmarks (based on geometric and anatomic evidence) were marked on the tooth using TPSdig software and analysed using Morpho J applying procrustes analysis and discriminant function analysis Results The results showed similar centroid sizes between gender (p = 0.606). Procrustes ANOVA for shape analysis showed a greater dimorphism between sexs (f value of 1.4 ; p value=0.0624). Discriminant function analysis based on the procrustes coordinates showed an overall accuracy of 90.91 % in classifying sex based on the landmark coordinates with correct classification of 20/22 (90.99%) females and 30/33 (90.91) males. Conclusion Shape of the tooth can be measured objectively using geometric morphometric methods which can be utilized to identify the sex of an individual. Enamel covering the crown of the teeth is biologically stable resisting climatic, physical and chemical insults. The enamel is derived from ectoderm and once formed does not change during the life. The tooth's structure and shape are determined by the sex chromosomes, which is well represented as sexual dimorphism. The study evaluates the occlusal and contact area morphology of premolars. These are important parameters considered during restorative treatment, functional rehabilitation and forensic investigations.

Maxillary first premolar shape (and not size) as an indicator of sexual dimorphism: A 2D geomorphometric study

Introduction The primary aim of the study is to evaluate the morphological form of the maxillary first premolar using 2D geomorphometry and evaluate the sexually dimorphic characteristics. Methods The present study was carried out on standardized photographs of right Maxillary first premolar from 55 dental casts (33 male and 22 females). Nineteen landmarks (based on geometric and anatomic evidence) were marked on the tooth using TPSdig software and analysed using Morpho J applying procrustes analysis and discriminant function analysis Results The results showed similar centroid sizes between gender (p = 0.606). Procrustes ANOVA for shape analysis showed a greater dimorphism between sexs (f value of 1.4 ; p value=0.0624). Discriminant function analysis based on the procrustes coordinates showed an overall accuracy of 90.91 % in classifying sex based on the landmark coordinates with correct classification of 20/22 (90.99%) females and 30/33 (90.91) males. Conclusion Shape of the tooth can be measured objectively using geometric morphometric methods which can be utilized to identify the sex of an individual. Enamel covering the crown of the teeth is biologically stable resisting climatic, physical and chemical insults. The enamel is derived from ectoderm and once formed does not change during the life. The tooth's structure and shape are determined by the sex chromosomes, which is well represented as sexual dimorphism. The study evaluates the occlusal and contact area morphology of premolars. These are important parameters considered during restorative treatment, functional rehabilitation and forensic investigations.

Indicators of sexual dimorphism in Homo antecessor permanent canines.

One of the main concerns of paleoanthropologists is to make a correct interpretation of the variability observed in the fossil record. However, the current knowledge about sexual dimorphism in the human lineage comes mainly from the study of modern human, Neanderthal and pre-Neanderthal populations, whereas information available about the intrapopulation variability of the groups that preceded these taxa is still ambiguous. In this preliminary study, Homo antecessor dental sample was assessed with the aim of trying to evaluate the degree of variability of their permanent canines` dental tissue proportions. Microtomographic techniques were here employed in order to measure and compare the crown volumes and surface areas of their enamel caps and dentine-pulp complexes. Then, the Pearson`s Coefficient of Variation and the Euclidean Distance were assessed to evaluate of intrapopulation variability of Gran Dolina TD6.2 dental sample. The values obtained were also compared with those of the dental samples from Sima de los Huesos site (Spain), the Neanderthal site of Krapina (Croatia), as well as from a broad forensic collection of known sex. Our results showed a marked intrapopulation variability in the dental tissues measurements of the canines of the individuals H1 and H3 from this site. This variability may be interpreted as an indicator of sexual dimorphism. If this is the case, H1 may be considered as a male individual, whereas H3 would be a female. Future discoveries of new fossils in the level TD6.2 of Gran Dolina site might help to confirm or refute this hypothesis.

Sternal Index in Human Fetuses as an Indicator of Sexual Dimorphism

Sternal Index in Human Fetuses as an Indicator of Sexual Dimorphism

Gender Trends in Mortality in the Irkutsk Region

Background. A hypothesis on the main role of factors of psychosocial and psychological distress in the formation of gender differences in mortality in the post-Soviet period is proposed. Aim of the research. To identify the characteristics and main causes of changes in gender trends and indicators of sexual dimorphism in mortality of the population of the Irkutsk region in the post-Soviet period. Methods. Statistical materials were obtained from the databases of the Federal State Statistic Service of the Russian Federation and from the Demographic Yearbooks of Russia. To establish the gender characteristics of irrevocable demographic losses, we analyzed the values of the male excess mortality index. It is defined as the ratio of the mortality rate of men to the corresponding indicator for women. We established the close connection between changes in the male supermortality index and the level of psychological distress of the population. The last index was determined by the suicide rate. Results. During the 31-year period (1987–2017), the highest values of the male mortality index were observed in 1993– 1995 and in 2001–2005. An indicator of the frequency of suicides is proposed and applied as a specific socio-demographic criterion for the influence of the factor of psychological distress on the socio-demographic status of the population. The dependence of the male supermortality index on the level of psychological distress for the period from 1991 to 2017 is estimated. A strong positive relationship between these indicators was identified (r = 0.792; p < 0.0001). Conclusion. Changes in the indicator of male supermortality largely depend on changes in the level of psychological distress. The indicator of sexual dimorphism of mortality (the index of male supermortality) can be used as an important indicator of pronounced changes in psychosocial and psychological distress and, accordingly, the quality of life of a society.

Evaluation of sexual dimorphism of histochemical activity of phosphatases of the plantar glands of Norway rats (Rattus norvegicus)

The activity of acid phosphatase, alkaline phosphatase and adenosine triphosphatase in the eccrine and sebaceous glands of the skin of the soles of the paws of male and female Norway rats was studied by histochemiсal methods. Using the methods of qualimetric analysis, we presented a digitalized form of the enzyme activity, which made it possible to calculate sexual dimorphism indices, reflecting quantitative differences in the enzymatic activity of the skin glands in males and females of Norway rats. For acid phosphatase activity, the sexual dimorphism index was equal to 0.50 in the eccrine glands and equal to 0.33 in the sebaceous glands. For alkaline phosphatase activity, values of sexual dimorphism indices were equal to –0.25 and 0.33 correspondingly, and for adenosine triphosphatase values of sexual dimorphism indices were equal to –0.33 and 0.50. Digital analogues of the histoenzymatic activity of the skin glands were presented as coordinates in three-dimensional space. Using the methods of analytical geometry, we calculated the values of intersexual distances (1.73 for eccrine glands and 1.73 for sebaceous glands), reflecting the cumulative differences in the activity of three types of phosphatases, which can be considered as an integral indicator of sexual dimorphism. Histochemical activity entropy is significant in the eccrine glands. Male entropy value (0.842 bit) was less than female entropy value (0.915 bit), because total actual activity of the males’ phosphatases was greater (220% of 300%) than total actual activity of the females’ phosphatases (200% of 300%). High entropy level of phosphatase activity was typical for male sebaceous glands (0.998 bit), where the general level of enzymatic activity was significantly reduced (160% of 300%). Because of the highest total actual phosphatase activity of female sebaceous glands (220% of 300%), entropy value was the lowest (0.842 bit). The obtained results show not only sexual dimorphism by histochemical parameters but show different communicational levels of male and female Norway rats, taking into account the important role of the plantar glands as sources of chemical signals determining the character of marking behaviour.

Morphological traits as indicators of sexual dimorphism in Prairie Rattlesnakes (Crotalus viridis)

Morphological traits as indicators of sexual dimorphism in Prairie Rattlesnakes (Crotalus viridis)

A morphometric study of predictors for sexual dimorphism of cervical part of vertebral column in human foetuses

IntroductionFoetal anatomy is the evolving specialty in the modern era. The first reason behind this is the advancement of a new field of in-utero foetal surgery and second reason is that it is related to medico-legal importance. MethodsAccording to the gestational age 30 foetuses were divided into two groups. Each group comprised of 10 male and 5 female foetuses with gestational age <25 and >25 weeks respectively, corresponding with 2nd and 3rd trimesters of pregnancy. Spinal cord was exposed by opening vertebral canal from behind by laminectomy. Transverse diameter of cervical vertebral canal and height of cervical vertebral body were measured at C3 to C7 vertebral levels. The aim of the study was to find the reference values of transverse diameter of vertebral canal and height of bodies of vertebrae at different cervical vertebral level and to appreciate whether it spectacles sexual dimorphism or not. Another aim was to decide which parameter (Transverse diameter of vertebral canal or height of the body of cervical vertebrae) of the vertebrae is the better indicator of sexual dimorphism. ResultsSexual difference at different vertebral levels was observed in only third trimester. The values of transverse diameter were more in females and height of the vertebral bodies in males at all levels of cervical vertebrae. The Cohen’s Kappa coefficient for transverse diameter of cervical vertebral canal is 0.6 whereas of height of the body of cervical vertebrae is 0.2. DiscussionBoth transverse diameter and height of cervical vertebrae (C3–C7) shows sexual dimorphism in third trimester. Between these two parameters, transverse diameter the vertebral canal of the cervical region proves to be a better indicator of gender.

Length–length and length–weight relationships for 48 fish species from reservoirs of the Paraná State, Brazil

AbstractLength–length and length–weight relationships was estimated for 48 fish species collected in 30 neotropical reservoirs located in the State of Paraná, Brazil. Significant relations were found for all species. The values of the parameter slope (b) in the length–weight relationship ranged from 2.49 to 3.46 for grouped sexes, and from 2.66 to 3.15 for separated sexes. Differences between sexes (indication of sexual dimorphism) were verified for 20 species. Males exhibited greater lengths than females for Astyanax janeiroensis, Bryconamericus iheringii, Geophagus brasiliensis, Glanidium ribeiroi and Hypostomus derbyi, whereas females attained greater lengths than males for the other 15 species examined in this study.

Middle Triassic archosaur population structure: interpretation based on Isochirotherium delicatum fossil footprints (Southern Alps, Italy)

Well-preserved archosaur footprints have recently been found on a single bedding plane in the Italian Alps. The tracks are referable to Isochirotherium delicatum Courel and Demathieu 1976, a form that was identified for the first time at the Anisian–Ladinian boundary in the area of Argentière (Ardèche, France). The Isochirotherium delicatum footprints and trackways from Gampenpass represent a possible social group or ‘herd’. Estimating the age of the trackmakers from the examination of the footprints is difficult and complicated by the fact that the sample can be divided into two groups of tracks (distinguishable by the L/ W, cross axis and interdigital angle). The diversity of the tracks is here interpreted as an indication of sexual dimorphism.

Technical note: a blind test of mandibular ramus flexure as a morphologic indicator of sexual dimorphism in the human skeleton

Loth and Henneberg (1996, Am. J. Phys. Anthropol. 99:473-487) identified a single morphological feature of the mandible, the presence or absence of a distinct flexure or angulation of the posterior margin of the mandibular ramus at the level of the occlusal plane, which appears to be an extraordinarily accurate predictor of sex. Using only this feature, Loth and Henneberg were able to predict sex with 94% accuracy in a large sample of mandibles. In this article, we report the results of a blind test of mandibular ramus flexure as a predictor of sex. In our blind test, only 62.5% of the mandibles were correctly sexed, and virtually identical results were obtained when the same sample of mandibles was examined by a second observer. Overall, our results demonstrate that: 1) the association between ramus flexure and sex is weak; 2) the predictive accuracy of Loth and Henneberg's method is better than chance for only one sex, males; and 3) the method is based on a trait that cannot be reliably or consistently identified.

Mandibular ramus flexure is a good indicator of sexual dimorphism

Mandibular ramus flexure is a good indicator of sexual dimorphism

Mandibular ramus flexure—indicator of sexual dimorphism?

Mandibular ramus flexure—indicator of sexual dimorphism?

Mandibular ramus flexure: A new morphologic indicator of sexual dimorphism in the human skeleton

Mandibular ramus flexure: A new morphologic indicator of sexual dimorphism in the human skeleton

Seymouria sanjuanensis (Amphibia, Batrachosauria) from the Lower Permian Cutler Formation of north-central New Mexico and the occurrence of sexual dimorphism in that genus questioned

Six specimens of the amphibian Seymouria, preserved in a single block of matrix from the Lower Permian Cutler Formation of north-central New Mexico, are described and referred to Seymouria sanjuanensis Vaughn. They are the only Seymouria specimens known from New Mexico and provide a more extensive definition of the species. It is interpreted that the specimens from New Mexico were collected from an early to middle Wolfcampian horizon and therefore represent the earliest known members of the genus. Evidence is presented that challenges previous explanations for the variability of several features of the skull and axial skeleton in specimens of Seymouria baylorensis and S. sanjuanensis as an indication of sexual dimorphism. Differences in the number of maxillary teeth, depth of the maxilla, and development of the maxillary dentition, particularly in the "canine" region, are interpreted as closely related morphological trends in Seymouria. Although no satisfactory explanation is offered for differences in the serial position of the first haemal arch and in the interorbital breadth, sexual dimorphism is considered very unlikely.

The structure of the antennae of the Florida Queen butterfly, Danaus gilippus berenice (Cramer).

AbstractInterest in the structure of the antennae of the Florida Queen butterfly arises from the finding that a pheromone is active in their courtship. Light and electron microscopic techniques were used to study the sensilla on the antennae and three types of sensilla with perforated walls were identified. The most common of these are short, thin‐walled pegs which are distributed over most of the antennal surface. Long, curved, thin‐walled pegs occur in patches on the inner medial antennal surface. Multiple coeloconic sensilla are present having up to 50 pegs in one sensillum. On the outer 28 flagellar subsegments there are two such sensilla per subsegment. In addition there are on the antennae long, thick‐walled hairs which are mechanoreceptors and probably also contact chemoreceptors. Sunken pegs, the function of which is not known, occur on the antennae. Grooved sensilla were found with the electron microscope but could not be identified with the light microscope. There was no indication of sexual dimorphism in sensilla types or numbers on the antennae.