scholarly journals Correlation Between Corpus Callosum Shape and Craniometric Measurements According to Mri Data

Author(s):  
Olga Boiagina ◽  
Oleksandr Stepanenko ◽  
Anastasiia Lebedieva

The correlation between the cranial height and the height of the corpus callosum trunk bulge, and the relationship between the corpus callosum shape and the cranial shape have not been studied. The purpose of the article was to determine the individual variability of the corpus callosum height and shape of adults, and their dependence on the cranial height and shape. The material was two samples from a series of MR scans of the head of men and women of the second period of adulthood (19 variations in each group) without the central nervous system pathology. Magnetic resonance tomographic scanner Magnetom C was used for obtaining MRI images. Morphometric study was conducted using RadiAnt Dicom Viewer software on MR scans performed in the sagittal area in T1- and T2-weighted images modes. According to the findings, the height of the corpus callosum trunk bulge of men is on average – 26.1 ± 2.8 mm, women – 25.2 ± 2.6 mm, and the neurocranium height – 150.4 ± 6.9 mm and 140.2 ± 4.2 mm, respectively. Wherein the aspect ratio of the neurocranium height to the corpus callosum trunk bulge height in men is 5.8 ± 0.7, in women – 5.6 ± 0.5. The aspect ratio of the corpus callosum longitudinal size along the constricting chord to its trunk bulge height in men is on average 2.8 ± 0.3, in women – 2.7 ± 0.3. The absence of correlation between the cranial height and the corpus callosum trunk bulge height, and the absence of correlation between the corpus callosum shape and cranial shape in people of the second period of adulthood have been concluded.

Author(s):  
R. V. Talash

The article presents a theoretical synthesis and a new solution of the scientific problem, which consists in determining the sexual and individual polymorphism of third molars through the age aspect. The review of the relevant literature, the results obtained by analysing orthopantograms of people at the first period of adulthood, and studying randomly selected third molars removed for various clinical reasons (more than 140 samples) are presented. It has been shown that erupted third molars considerably vary in size and shape that is due to different combinations of configurational relationship between the crown and root parts. This depends on the location of opposing teeth in the dentition and sex as well, but does not correlate with age. Moreover, the entire range of individual and sexual variability of the third molars is limited by two extreme forms: very large teeth with long divided roots or with a quadratubercular crown, which are not significantly different from typical molars, and very small analogues with one fused root section, the crowns of which resemble small permanent teeth. Between these forms all other are distributed and most numerous types we called as intermediate. The data analyzed indicate that the individual variability of the size of the teeth in length depends entirely on the length of their root sections. It has been established that, relative to the crown-root index, there are three forms distinguished among the third molars: long-root; medium root and short root. At the same time, long-root forms are found mainly among male teeth, mid-root forms are more characteristic of female wisdom teeth, and short-root forms of third molars do not show a sex difference. The results obtained demonstrate that the orthopantogram of the dentofacial system in humans (aged 22 to 35 years) reliably reveals an inverse relationship between the longitudinal size and the term of eruption of the third molars. The systematic approach used in the work made it possible to bring the varied polymorphism of the third molars into a certain order, highlighting the most indicative features for their classification.


Author(s):  
Olga Boiagina ◽  

The corpus callosum in the interval between the cerebral hemispheres is a plate of white matter, uneven in thickness, in which two surfaces are distinguished - the upper and lower ones, bent according to its lateral profile. The objective of the study was to study the individual variability of location of the lateral and medial longitudinal strips on the upper surface of the corpus callosum, as well as structural features of its lower surface. The material was the brain of men and women (10 specimens each) of the second period of adulthood, who died for the causes not related to the pathology of the central nervous system. After two weeks of fixation in a 10% formalin solution, the brain was prepared by separating the cerebral hemispheres and other parts of the brain from the corpus callosum, resulting in exposure of its upper and lower surface, which was photographed using a digital camera. As evidenced by the obtained data, the width of the trunk of the corpus callosum in men varies from 9 to 16 mm, whereas in women the difference between the minimum (11.0 mm) and the maximum (20.0 mm) values is greater than in men, when in fact there is only small difference of the arithmetic mean value. Thus, we offer to consider the lateral longitudinal strips to be the boundaries of the corpus callosum hemispherical part and the distance between them determines the width of this formation, which in average is 13.0 ± 2.5 mm in men and 14.4 ± 2.7 mm in women. In the meantime, the nature of the individual variability of the width of the corpus callosum trunk in women is more diverse than in men.


Author(s):  
O.V. Mareev ◽  
◽  
G.O. Mareev ◽  
M.E. Gutynina ◽  
D.A. Maksimova ◽  
...  

2017 ◽  
Author(s):  
Joel B Bennett ◽  
Michael Neeper ◽  
Brittany D Linde ◽  
Gale M Lucas ◽  
Lindsay Simone

BACKGROUND The majority of resilience interventions focus on the individual. Workplace resilience is a growing field of research. Given the ever-increasing interconnectedness in businesses, teamwork is a guarantee. There is also growing recognition that resilience functions at the team level. OBJECTIVE The objective of our work was to address three shortcomings in the study of workplace resilience interventions: lack of interventions focusing on group-level or team resilience, the need for brief interventions, and the need for more theoretical precision in intervention studies. METHODS The authors took an established evidence-based program (Team Resilience) and modified it based on these needs. A working model for brief intervention evaluation distinguishes outcomes that are proximal (perceptions that the program improved resilience) and distal (dispositional resilience). A total of 7 hypotheses tested the model and program efficacy. RESULTS Two samples (n=118 and n=181) of engineering firms received the Web-based training and provided immediate reactions in a posttest-only design. The second sample also included a control condition (n=201). The findings support the model and program efficacy. For example, workplace resilience was greater in the intervention group than in the control group. Other findings suggest social dissemination effects, equal outcomes for employees at different stress levels, and greater benefit for females. CONCLUSIONS This preliminary research provides evidence for the capabilities of e-learning modules to effectively promote workplace resilience and a working model of team resilience.


2019 ◽  
Author(s):  
Vera Weisbecker ◽  
Thomas Guillerme ◽  
Cruise Speck ◽  
Emma Sherratt ◽  
Hyab Mehari Abraha ◽  
...  

AbstractBackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, shape variation should not be dominated by allometry; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of thre species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraint act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.


2020 ◽  
Vol 19 (3) ◽  
pp. 467-483 ◽  
Author(s):  
Georgios Tsaparlis

This work analyses students’ failure in the 2019 Nationwide Chemistry Examination in Greece, which concerns secondary education graduates, competing for admission to higher education Greek institutions. The distinction of thinking skills into higher and lower order (HOTS and LOTS) is used as a theoretical tool for this analysis. The examination included several questions that contained HOTS elements that had been unusual in previous examinations. This led to a decrease in overall student performance but better discrimination between outstanding and good students. Based on two samples of examination papers, corresponding to very similar subsets of the student population, the 2018 and 2019 examinations are compared, and the individual 2019 questions are evaluated. It was found that section B of the 2019 examination paper (which included contexts unfamiliar to the students, and for which, a large effect size between 2018 and 2019 was calculated) may have caused the large drop. An important link is established between the 2019 low performance and the HOTS and LOTS features of the questions, and the role or non-role of algorithmic calculations is examined. In addition, the critical opinions of chemistry teachers are provided, with a consensus emerging in favour of connecting chemistry with everyday life. Keywords: chemistry examinations, higher-order cognitive skills, higher-order thinking skills, student assessment, twelfth-grade chemistry.


2020 ◽  
Vol 19 (4) ◽  
pp. 10-14
Author(s):  
Z. Masna

The individual face shape, the ratio of its proportions, the articulation capabilities of each person to a significant extent depend on the characteristics of occlusion and occlusion, in turn, are determined by the size, shape and ratio of dental, alveolar and basal arches. Two of them - alveolar and basal - pass at the corresponding levels of the alveolar areas of the jaws, which means that it is almost impossible to correct them, therefore they play the role of landmarks for setting the dental arch during dental prosthetics. A full-fledged aesthetic and functional restoration of the maxillofacial region after prosthetics largely depends on the dentist taking into account the individual morphological characteristics of the jaws, their cellular areas and specifically the morphometric parameters of the collar and basal arches. In order to determine the possible variants of the shape of the alveolar and basal arches of the upper jaw and the patterns of their ratio during the routine dental examination, 55 people (27 men and 28 women) aged 21-60 years with preserved maxillary dentition were examined. It has been established that the alveolar and basal arches of the upper jaw can have the shape of five geometric shapes: an oval, a semicircle, an ellipse, a trapezoid or a square. In this case, the shape of the collar and basal arches can coincide or be combined in various combinations. The analysis of the obtained results showed that in men the alveolar arch most often had the shape of an oval (70%), in women - an oval or semicircle (43%, respectively). With the aim of possible variants of the alveolar and basal arches form determination and peculiarities of their correlation 55 individuals (27 men and 28 women) in age of 21-60 years with the preserved teeth row were examined during planned dental examination. All examined were patients of the “Dental clinic of dr. Dakhno” (Kyiv). Computer tomographic investigation was made to these patients according to medical indications, scanning was made parallely to the occlusal plane. Image reconstruction was conducted with the use of highly dimentional bone algorithm. Alveolar and basal arch form of the upper jaw were determined on the images. It was established that alveolar and basal arches of the upper jaw can have a form of five geometrical figures: oval, semicircle, ellipse, trapeze or square. Form of the alveolar and basal arches can match or can combine in different combinations. Received results analysis testified that alveolar arch has a form of the oval in men and oval or semicircle – in women. Basal arch in men also most frequently has a form of oval, less often – semicircle, square and trapeze. In women basal arch more often has a form of trapeze or semicircle, less often – oval or square. In men alveolar and basal arches form matched in 41% of cases, in women – only in 31% of cases among total amount of all examined individuals. Most often alveolar and basal arches matched in the form of oval and semicircle, only in one case arches of the trapeze form matched in man, in woman – square form. Maxillary alveolar and basal arches form variants analysis let to determine areas, where distance between alveolar crests was maximal. Most variable this index was in individuals with the oval form of the alveolar arch on the level of 16-26, 17-27 or 18-28 teeth. Peculiarities of the alveolar and basal arches form of the alveolar process of the upper jaw in male and female individuals are characterized with expressed individual variability. These peculiarities consideration during dental prosthesis let avoid series of complications connected with the pressure redistribution on the osseous tissue of the jaws during articulation. 


Antibiotics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 479
Author(s):  
Kirstin Vach ◽  
Ali Al-Ahmad ◽  
Annette Anderson ◽  
Johan Peter Woelber ◽  
Lamprini Karygianni ◽  
...  

The influence of a change in nutrition on the oral microbiota are discussed in literature, but usually only changes of population mean values are reported. This paper introduces simple methods to also analyse and report the variability of patients’ reactions considering data from the culture analysis of oral biofilm. The framework was illustrated by an experimental study exposing eleven participants to different nutrition schemes in five consecutive phases. Substantial inter-individual variations in the individual reactions were observed. A new coherence index made it possible to identify 14 instances where the direction of individual changes tended to coincide with the direction of the mean change with more than 95% probability. The heterogeneity in variability across different bacteria species was limited. This allowed us to develop recommendations for sample sizes in future studies. For studies measuring the concentration change of bacteria as a reaction to nutrition change, the use of replications and analysis of the variability is recommended. In order to detect moderate effects of a change in nutrition on the concentration of single bacterial taxa, 30 participants with three repetitions are often adequate. Insights into the relationship between nutrition and the microbial composition can be helpful for the development of dietary habits that promote the establishment of a healthy microbial flora and can therefore prevent the initiation of oral diseases such as caries and periodontitis.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Nikki Mills ◽  
Donna T. Geddes ◽  
Satya Amirapu ◽  
S. Ali Mirjalili

Lingual frenotomy has become an increasingly common surgical procedure, performed for a broad range of indications from birth through adulthood. This study utilizes histology to define the structure and tissue composition of the lingual frenulum and floor of mouth (FOM) fascia. En bloc specimens of anterior tongue, lingual frenulum, and FOM tissues were harvested from ten embalmed adult cadavers. An additional three fresh tissue cadaveric specimens were frozen with the tongue supported in an elevated position, to enable harvesting and paraffin embedding of the elevated lingual frenulum as a discrete specimen. All 13 specimens were prepared as ten-micron coronal sections using stains to determine the general morphology of the lingual frenulum, its relationship to neighbouring structures (Mason’s Trichrome), presence of elastin fibers (Verhoeff-van Gieson), and collagen typing (Picrosirius Red). Our results have shown a submucosal layer of fascia spanning horizontally across the FOM was present in all specimens, with variability in fascial thickness and histologic composition. This FOM fascia suspends the sublingual glands, vessels, and genioglossus from its deep surface. The elevated lingual frenulum is formed by a central fold of this FOM fascia together with the overlying oral mucosa with variability in fascial thickness and composition. With tongue elevation, the fascia mobilizes to a variable extent into the fold forming the frenulum, providing a structural explanation for the individual variability in lingual frenulum morphology seen in clinical practice.


2014 ◽  
Vol 10 (5) ◽  
pp. 20140095 ◽  
Author(s):  
Kathleen Wermke ◽  
Johannes Hain ◽  
Klaus Oehler ◽  
Peter Wermke ◽  
Volker Hesse

The specific impact of sex hormones on brain development and acoustic communication is known from animal models. Sex steroid hormones secreted during early development play an essential role in hemispheric organization and the functional lateralization of the brain, e.g. language. In animals, these hormones are well-known regulators of vocal motor behaviour. Here, the association between melody properties of infants' sounds and serum concentrations of sex steroids was investigated. Spontaneous crying was sampled in 18 healthy infants, averaging two samples taken at four and eight weeks, respectively. Blood samples were taken within a day of the crying samples. The fundamental frequency contour (melody) was analysed quantitatively and the infants' frequency modulation skills expressed by a melody complexity index (MCI). These skills provide prosodic primitives for later language. A hierarchical, multiple regression approach revealed a significant, robust relationship between the individual MCIs and the unbound, bioactive fraction of oestradiol at four weeks as well as with the four-to-eight-week difference in androstenedione. No robust relationship was found between the MCI and testosterone. Our findings suggest that oestradiol may have effects on the development and function of the auditory–vocal system in human infants that are as powerful as those in vocal-learning animals.


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