scholarly journals Semicircular canals in Anolis lizards: ecomorphological convergence and ecomorph affinities of fossil species

2017 ◽  
Vol 4 (10) ◽  
pp. 170058 ◽  
Author(s):  
Blake V. Dickson ◽  
Emma Sherratt ◽  
Jonathan B. Losos ◽  
Stephanie E. Pierce
Keyword(s):  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Greater Antilles ◽  
Ecological Niches ◽  
Fossil Species ◽  
Modern Species ◽  
Behavioural Characteristics ◽  
The Relationship ◽  
Canal Morphology

Anoli s lizards are a model system for the study of adaptive radiation and convergent evolution. Greater Antillean anoles have repeatedly evolved six similar forms or ecomorphs: crown-giant, grass-bush, twig, trunk, trunk-crown and trunk-ground. Members of each ecomorph category possess a specific set of morphological, ecological and behavioural characteristics which have been acquired convergently. Here we test whether the semicircular canal system—the organ of balance during movement—is also convergent among ecomorphs, reflecting the shared sensory requirements of their ecological niches. As semicircular canal shape has been shown to reflect different locomotor strategies, we hypothesized that each Anolis ecomorph would have a unique canal morphology. Using three-dimensional semilandmarks and geometric morphometrics, semicircular canal shape was characterized in 41 Anolis species from the Greater Antilles and the relationship between canal shape and ecomorph grouping, phylogenetic history, size, head dimensions, and perch characteristics was assessed. Further, canal morphology of modern species was used to predict the ecomorph affinity of five fossil anoles from the Miocene of the Dominican Republic. Of the covariates tested, our study recovered ecomorph as the single-most important covariate of canal morphology in modern taxa; although phylogenetic history, size, and head dimensions also showed a small, yet significant correlation with shape. Surprisingly, perch characteristics were not found to be significant covariates of canal shape, even though they are important habitat variables. Using posterior probabilities, we found that the fossil anoles have different semicircular canals shapes to modern ecomorph groupings implying extinct anoles may have been interacting with their Miocene environment in different ways to modern Anolis species.

scholarly journals Semicircular canals in Anolis lizards: ecomorphological convergence and ecomorph affinities of fossil species

2017 ◽  
Author(s):  
Blake V. Dickson ◽  
Emma Sherratt ◽  
Jonathan B. Losos ◽  
Stephanie E. Pierce
Keyword(s):  
Semicircular Canal ◽  
Semicircular Canals ◽  
Greater Antilles ◽  
Ecological Niches ◽  
Fossil Species ◽  
Modern Species ◽  
Behavioural Characteristics ◽  
The Relationship ◽  
Significant Covariates ◽  
Canal Morphology

AbstractAnolis lizards are a model system for the study of adaptive radiation and convergent evolution. Greater Antillean anoles have repeatedly evolved six similar forms or ecomorphs: crown-giant, grass-bush, twig, trunk, trunk-crown, and trunk-ground. Members of each ecomorph category possess a specific set of morphological, ecological and behavioural characteristics which have been acquired convergently. Here we test whether the semicircular canal system – the organ of balance – is also convergent among ecomorphs, reflecting the shared sensory requirements of their ecological niches. As semicircular canal shape has been shown to reflect different locomotor strategies, we hypothesised that each Anolis ecomorph would have a unique canal morphology. Using 3D semilandmarks and geometric morphometrics, semicircular canal shape was characterised in 41 Anolis species from the Greater Antilles and the relationship between canal shape and ecomorph grouping, phylogenetic history, size, and perch characteristics was assessed. Further, canal morphology of modern species was used to predict the ecomorph affinity of five fossil anoles from the Miocene of the Dominican Republic. Our study recovered ecomorph as the single-most important covariate of canal morphology in modern taxa; although phylogenetic history and size also showed a small, yet significant correlation with shape. Surprisingly, perch characteristics were not found to be significant covariates of canal shape, even though they are important habitat variables. Using posterior probabilities, we found that the fossil anoles have different semicircular canals shapes to modern ecomorph groupings implying extinct anoles may have been interacting with their Miocene environment in different ways to modern Anolis species.

Alexander Crum Brown: A Forgotten Pioneer in Vestibular Sciences

2020 ◽  
Vol 163 (3) ◽  
pp. 557-559
Author(s):  
Soumit Dasgupta ◽  
Marco Mandala ◽  
Enis Alpin Guneri
Keyword(s):  
19Th Century ◽  
Semicircular Canal ◽  
Semicircular Canals ◽  
Vestibular Compensation ◽  
Renaissance Period ◽  
Theory Of Motion ◽  
Vestibular Pathology ◽  
Relationship Of ◽  
The 19Th Century ◽  
The Relationship

Although vestibular anatomy was described in the Renaissance period, research in vestibular physiology began in the 1820s and was spearheaded by Purkinje and Flourens. This was subsequently expanded by Ménière, Helmholtz, Goltz, Mach, Breuer, Ewald, and Hogyes, who are regarded as the early pioneers in research on vestibular physiology in the 19th century. The relationship of endolymphatic flow and semicircular canal function is termed the Mach-Breuer hypothesis. What is less well known is that a Scottish chemist, Alexander Crum Brown, arrived at similar conclusions as Mach and Breuer at the same time quite independently. In fact, he pioneered several concepts in vestibular physiology that included pairing of semicircular canals for function, the vestibular pathway, optic fixation elimination in vestibular experimentation, the theory of motion intolerance, and study in deaf mutes for insights into vestibular pathology and vestibular compensation. This article is a tribute to this forgotten pioneer in vestibular research.

scholarly journals Automatic Measurement of Inner Ear in Different Mammals1

2020 ◽  
Author(s):  
Yi Du ◽  
Han-dai Qin ◽  
Chen Liu ◽  
Da Liu ◽  
Shuo-long Yuan ◽  
...  
Keyword(s):  
Inner Ear ◽  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Automatic Measurement ◽  
The Body ◽  
Human Data ◽  
Dimensional Models ◽  
Three Dimensional Models ◽  
Mini Pigs

AbstractObjectiveThe aim of this research is to develop an accurate and automatic measuring method based on the aid of centerline to construct three dimensional models of inner ear in different mammals and to assess the morphological variations.MethodsThree adult healthy mice, three adult guinea pigs, three adult mini pigs and one left temporal bone of human were included in this research. All 18 animal specimens and the human sample were scanned with the use of Micro-CT. After being segmented, three-dimensional models of the inner ear in different mammals were reconstructed using Mimics. A novel method with the use of centerline was established to estimate the properties of 3D models and to calculate the length, volume and angle parameters automatically.ResultsMorphological models of inner ears in different mammals have been built, which describe detailed shape of cochlear, vestibule, semicircular canals and common crus. Mean value of lengths and volumes of the cochlear, lateral semicircular canal, superior semicircular canal and posterior semicircular canal, tended to increase with the body size of the mammals, showed the proximity to the human data in mini pig. The angles between the semicircular canal planes showed differences between mammals. The mean values of semicircular canals of mice and mini pigs closely resembled to human data in numerical assessment.ConclusionThe automatic measurement of the inner ear based on centerline builds an effective way to assess lengths, volumes and angles of three-dimensional structures. This study provides a theoretical basis for mechanical analysis of inner ear in different mammals and proves the similarity between mini pig and human.

Analysis of the coplanarity of functional pairs of semicircular canals using three-dimensional images reconstructed from temporal bone magnetic resonance imaging

2015 ◽  
Vol 129 (5) ◽  
pp. 430-434 ◽  
Author(s):  
D-K Kim ◽  
D-R Kim ◽  
S H Jeong ◽  
G J Kim ◽  
K-H Chang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Temporal Bone ◽  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Normal Subjects ◽  
Magnetic Resonance Images ◽  
Posterior Semicircular Canal ◽  
Horizontal Semicircular Canal ◽  
The Right

AbstractObjectives:This study was conducted to investigate the angles and orientation of semicircular canals, and the coplanarity of functional canal pairs.Methods:Fluid signals in semicircular canals were reconstructed with three-dimensional reconstruction software using 20 temporal bone magnetic resonance images of normal subjects. The angles between each pair of semicircular canals were measured.Results:The mean angles between the anterior and horizontal semicircular canal plane, the horizontal and posterior semicircular canal plane, and the anterior and posterior semicircular canal plane were 83.7°, 82.5° and 88.4°, respectively. Pairs of contralateral synergistic canal planes were formed 15.1° between the right and left horizontal semicircular canal planes, 21.2° between the right anterior and left posterior semicircular canal, and 21.7° between the left anterior and right posterior semicircular canal.Conclusion:Each semicircular canal makes an almost right angle with other canals, but synergistically acting functional canal pairs of both ears do not lie in exactly the same plane.

Head impulses reveal loss of individual semicircular canal function

1999 ◽  
Vol 9 (3) ◽  
pp. 173-180
Author(s):  
S.T. Aw ◽  
G.M. Halmagyi ◽  
R.A. Black ◽  
I.S. Curthoys ◽  
R.A. Yavor ◽  
...  
Keyword(s):  
Semicircular Canal ◽  
Three Dimensional ◽  
Semicircular Canals ◽  
Normal Subjects ◽  
Three Dimensions ◽  
Posterior Canal ◽  
Head Velocity ◽  
Ocular Reflex ◽  
Vestibular Ocular Reflex ◽  
Head Impulses

We studied individual semicircular canal responses in three dimensions to high-acceleration head rotations (“head impulses”) in subjects with known surgical lesions of the semicircular canals, and compared their results to those of normal subjects. We found that vestibular-ocular reflex (VOR) gains at close to peak head velocity in response to yaw, pitch and roll impulses were reliable indicators of semicircular canal function. When compared to normals, lateral canal function showed a 70–80% gain at peak of yaw head velocity during ipsilesional yaw impulses. After the loss of one vertical canal function there was a 30–50% and torsional VOR gain in response to ipsilesional pitch and roll impulses respectively. Bilateral deficits in anterior or posterior canal function resulted in a 80–90% impulses, while the loss of ipsilateral anterior and posterior canal functions will result in a 80–90% ipsilesional roll impulses. Three-dimensional vector analysis and animation of the VOR responses in a unilateral vestibular deafferented subject to yaw, pitch and roll impulses further demonstrated the deficits in magnitude and direction of the VOR responses following the loss of unilateral lateral, anterior and posterior canal functions.

Three-dimensional Computed Tomographic Analysis of the Relationship Between the Arcuate Eminence and the Superior Semicircular Canal

2006 ◽  
Vol 59 (suppl_1) ◽  
pp. ONS-7-ONS-12 ◽  
Author(s):  
Ketan R. Bulsara ◽  
Jean-Christophe Leveque ◽  
Linda Gray ◽  
Takanori Fukushima ◽  
Allan H. Friedman ◽  
...  
Keyword(s):  
Semicircular Canal ◽  
Average Distance ◽  
Three Dimensional ◽  
Middle Cranial Fossa ◽  
Surgical Approaches ◽  
Precise Position ◽  
Superior Semicircular Canal ◽  
Bony Landmarks ◽  
Cranial Fossa ◽  
The Relationship

Abstract OBJECTIVE: The location of the superior semicircular canal (SSC) is often determined intraoperatively based on its topographic association with the arcuate eminence (AE). This determination is not always possible because of the potential variability in the relationship between these two structures. The goal of this study was to describe the three-dimensional (3-D) relationship between the AE and SSC using 3-D computed tomography (CT) and to evaluate the utility of 3-D CT for preoperative planning for surgical approaches to the middle cranial fossa. METHODS: We studied 11 patients (22 sides) radiographically using 0.8- to 1-mm thick reconstructed CT images. A standard set of structural relationships was measured between the AE, SSC, and other regional landmarks. RESULTS: 3-D CT clearly demonstrated the relationships between traditional landmarks along the petrous ridge and middle cranial fossa. The relationship between the arcuate eminence and SSC was found to be highly variable. The average distance between the tips of the two structures was found to be 5.7 mm (range, 2.7–10.4 mm). CONCLUSIONS: There is significant variability in the relationship between the AE and the SSC. The AE is not a consistent or reliable landmark for identifying the precise position of the SSC. Detailed preoperative information regarding the relationship between the AE, SSC, and other bony landmarks can be easily and quickly assessed using 3-D CT.

scholarly journals A Microcomputed Tomographic Evaluation of Root Canal Morphology of Maxillary Second Premolars in a Pakistani Cohort

2021 ◽  
Vol 11 (11) ◽  
pp. 5086
Author(s):  
Mazen F. Alkahtany ◽  
Saqib Ali ◽  
Abdul Khabeer ◽  
Shafqat A. Shah ◽  
Khalid H. Almadi ◽  
...  
Keyword(s):  
Root Canal ◽  
Three Dimensional ◽  
Ct Scanning ◽  
Micro Ct ◽  
Single Root ◽  
Root Canal Morphology ◽  
Spss Software ◽  
Variable Morphology ◽  
Canal Morphology

This study aimed to investigate variations in the root canal morphology of maxillary second premolar (MSP) teeth using microcomputed tomography (micro-CT). Sixty (N = 60) human extracted MSPs were collected and prepared for micro-CT scanning. The duration for scanning a single sample ranged between 30 and 40 min and a three-dimensional (3-D) image was obtained for all the MSPs. The images were evaluated by a single observer who recorded the canal morphology type, number of roots, canal orifices, apical foramina(s), apical delta(s), and accessory canals. The root canal configuration was categorized in agreement with Vertucci’s classification, and any configuration not in agreement with Vertucci’s classification was reported as an “additional canal configuration”. Descriptive statistics (such as mean percentages) were calculated using SPSS software. The most common types agreeing with Vertucci’s classification (in order of highest to lowest incidence) were types I, III, V, VII, II, and VI. The teeth also exhibited four additional configurations that were different from Vertucci’s classification: types 2-3, 1-2-3, 2-1-2-1, and 1-2-1-3. A single root was found in 96.7% and the majority of the samples demonstrated two canals (73.3%). Further, 80% of the teeth showed one canal orifice. The number of apical foramina’s in the teeth was variable, with 56.7% having solitary apical foramen. The accessory canal was found in 33.3%, and apical delta was found in only 20% of the samples. Variable morphology of the MSPs was detected in our study. The canal configuration most prevalent was type 1; however, the results also revealed some additional canal types.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

scholarly journals A Field Measurement Based Wind Characteristics Analysis of a Typhoon in Near-Ground Boundary Layer

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 873
Author(s):  
Dandan Xia ◽  
Liming Dai ◽  
Li Lin ◽  
Huaifeng Wang ◽  
Haitao Hu
Keyword(s):  
Turbulence Intensity ◽  
Field Measurement ◽  
Three Dimensional ◽  
Wind Data ◽  
Statistical Characteristics ◽  
Gust Factor ◽  
Characteristics Analysis ◽  
Wind Characteristics ◽  
The Mean ◽  
The Relationship

The field measurement was conducted to observe the wind field data of West Pacific typhoon “Maria” in this research. With the application of ultrasonic anemometers installed in different heights (10 m, 80 m, 100 m) of the tower, the three dimensional wind speed data of typhoon “Maria” was acquired. In addition, vane-type anemometers were installed to validate the accuracy of the wind data from ultrasonic anemometers. Wind characteristics such as the mean wind profile, turbulence intensity, integral length scale, and wind spectrum are studied in detail using the collected wind data. The relationship between the gust factor and turbulence intensity was also studied and compared with the existing literature to demonstrate the characteristics of Maria. The statistical characteristics of the turbulence intensity and gust factor are presented. The corresponding conclusion remarks are expected to provide a useful reference for designing wind-resistant buildings and structures.

Sign in / Sign up

Export Citation Format

Share Document