THE STUDY OF THE INDIVIDUAL VARIABILITY OF THE LINEAR DIMENSIONS OF THE SPHENOID SINUS

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


2012 ◽  
Vol 58 (2) ◽  
pp. 358-362 ◽  
Author(s):  
Ned A. Dochtermann ◽  
C. M. Gienger

Abstract Understanding how population sizes vary over time is a key aspect of ecological research. Unfortunately, our understanding of population dynamics has historically been based on an assumption that individuals are identical with homogenous life-history properties. This assumption is certainly false for most natural systems, raising the question of what role individual variation plays in the dynamics of populations. While there has been an increase of interest regarding the effects of within population variation on the dynamics of single populations, there has been little study of the effects of differences in within population variation on patterns observed across populations. We found that life-history differences (clutch size) among individuals explained the majority of the variation observed in the degree to which population sizes of eastern fence lizards Sceloporus undulatus fluctuated. This finding suggests that differences across populations cannot be understood without an examination of differences at the level of a system rather than at the level of the individual [Current Zoology 58 (2): 358–362, 2012].


2020 ◽  
Vol 117 (50) ◽  
pp. 31754-31759
Author(s):  
Sang Hyun Choi ◽  
Vikyath D. Rao ◽  
Tim Gernat ◽  
Adam R. Hamilton ◽  
Gene E. Robinson ◽  
...  

The duration of interaction events in a society is a fundamental measure of its collective nature and potentially reflects variability in individual behavior. Here we performed a high-throughput measurement of trophallaxis and face-to-face event durations experienced by a colony of honeybees over their entire lifetimes. The interaction time distribution is heavy-tailed, as previously reported for human face-to-face interactions. We developed a theory of pair interactions that takes into account individual variability and predicts the scaling behavior for both bee and extant human datasets. The individual variability of worker honeybees was nonzero but less than that of humans, possibly reflecting their greater genetic relatedness. Our work shows how individual differences can lead to universal patterns of behavior that transcend species and specific mechanisms for social interactions.


Diagnostics ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 170 ◽  
Author(s):  
Asseel Khalaf ◽  
Caroline L. Hoad ◽  
Elaine Blackshaw ◽  
Jaber Alyami ◽  
Robin C. Spiller ◽  
...  

Measurement of gastric emptying is of clinical value for a range of conditions. Gamma scintigraphy (GS) has an established role, but the use of magnetic resonance imaging (MRI) has recently increased. Previous comparison studies between MRI and GS showed good correlation, but were performed on separate study days. In this study, the modalities were alternated rapidly allowing direct comparison with no intra-individual variability confounds. Twelve healthy participants consumed 400 g of Technetium-99m (99mTc)-labelled soup test meal (204 kcal) and were imaged at intervals for 150 min, alternating between MRI and GS. The time to empty half of the stomach contents (T1/2) and retention rate (RR) were calculated and data correlated. The average T1/2 was similar for MRI (44 ± 6 min) and GS (35 ± 4 min) with a moderate but significant difference between the two modalities (p < 0.004). The individual T1/2 values were measured, and MRI and GS showed a good positive correlation (r = 0.95, p < 0.0001), as well as all the RRs at each time point up to 120 min. Gastric emptying was measured for the first time by MRI and GS on the same day. This may help with translating the use of this simple meal, known to elicit reliable, physiological, and pathological gastrointestinal motor, peptide, and appetite responses.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Chang-Hee Han ◽  
Jeong-Hwan Lim ◽  
Jun-Hak Lee ◽  
Kangsan Kim ◽  
Chang-Hwan Im

It has frequently been reported that some users of conventional neurofeedback systems can experience only a small portion of the total feedback range due to the large interindividual variability of EEG features. In this study, we proposed a data-driven neurofeedback strategy considering the individual variability of electroencephalography (EEG) features to permit users of the neurofeedback system to experience a wider range of auditory or visual feedback without a customization process. The main idea of the proposed strategy is to adjust the ranges of each feedback level using the density in the offline EEG database acquired from a group of individuals. Twenty-two healthy subjects participated in offline experiments to construct an EEG database, and five subjects participated in online experiments to validate the performance of the proposed data-driven user feedback strategy. Using the optimized bin sizes, the number of feedback levels that each individual experienced was significantly increased to 139% and 144% of the original results with uniform bin sizes in the offline and online experiments, respectively. Our results demonstrated that the use of our data-driven neurofeedback strategy could effectively increase the overall range of feedback levels that each individual experienced during neurofeedback training.


1970 ◽  
Vol 19 (4) ◽  
pp. 493-506 ◽  
Author(s):  
L. Gedda ◽  
G. Brenci

SummaryThe phenomenon of life, in its individual and collective expressions, develops through a sequence of times resulting from the interference of biological with physical time. While physical time is uniform, the biological one differs from one individual to the other, except for MZ twins.The problem of biological time has been studied in physiology and informational genetics from the viewpoint of its succession of single times, although irrespective of the individual variability in their duration. This variability has already been shown by the authors to be hereditary, its inheritance being directly connected with the hereditary unit.Biological time corresponds to the duration of degradation (“chronon”) of the energy of stability (“ergon”) possessed by the gene and, by extension, to the total chronon of the genotypes underlying a given structure or function. Ergon and chronon are correlated index values, thereby constituting a system (“E/C system”).The individual variability of biological time depends on the A-T/G-G ratio in the DNA molecule, on the different amount of genie redundancy and on the different possibilities of repair of corresponding genes. The variability of these or possibly other causal factors determines the stability with respect to the environment in which the information operates, and especially to mutagenic agents.The authors apply the E/C model to epidemiologic data concerning diabetes, lupus erythematosus, and peptic ulcer, and verify the consistency of the experimental data with the theoretical model.


1996 ◽  
Vol 63 (2) ◽  
pp. 189-200 ◽  
Author(s):  
L. Pérochon ◽  
J. B. Coulon ◽  
F. Lescourret

AbstractFive published equations were compared on their ability to adjust different patterns of lactation curves. The equation y(t) = a exp(b1t'2/2 + b2/t – c(l + t'/2)t') with t' = (t – 21·4)/l00 (i) was retained because of the quality of the adjustment and the absence of convergence problems when applied on individual curves. Including an effect of season (SE) and an effect of pregnancy (PE) improved the quality of individual adjustments (no. = 339). The final equation was equal to (i) + SE + PE with SE = a + b cos (2π(wc + w - l)/52) + c sin(2n(wc + w - 1)/52), with wc= week of the year at calving, w = week after calving and a = 0·0065, b = -1·26 and c = 0·374, and PE = a (wp –18) e-bwp, with w p = week of pregnancy and a, b fixed parameters. Individual cow characteristics were used to analyse equation (i) parameters. The predictions obtained with this equation and several predictive functions of the equation (i) parameters, which differed in the way they included or not the potential of production, were compared. With no indication of this potential, the prediction was very poor. With the initial production (mean production of the 4th, 5th and 6th days of lactation) as an estimate of this potential, 75% of the lactations had the median of absolute values of errors less than 2·95 kg/day. The results were highly improved by using the yield during the 5th week of lactation. The threshold of 2·95 was reduced to about 2 kg/day. The quality of the individual prediction was better for primiparous than for multiparous cows, and for French Friesian and Montbeliarde cows than for pure or crossbred Holstein cows. Although individual predictions were not always satisfactory, they provided excellent agreement when averaged per group (20 cows).


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