Assessment of the mass, length, center of mass, and principal moment of inertia of body segments in adult males of the brown anole (Anolis sagrei) and green, or carolina, anole (Anolis carolinensis)

2012 ◽  
Vol 273 (7) ◽  
pp. 765-775 ◽  
Author(s):  
Pierre Legreneur ◽  
Dominique G. Homberger ◽  
Vincent Bels
Keyword(s):  
Center Of Mass ◽  
Anolis Carolinensis ◽  
Moment Of Inertia ◽  
Adult Males ◽  
Principal Moment ◽  
Anolis Sagrei ◽  
Body Segments ◽  
Brown Anole

scholarly journals Assessing display variability in wild brown anoles Anolis sagrei using a mechanical lizard model

2011 ◽  
Vol 57 (2) ◽  
pp. 140-152 ◽  
Author(s):  
Sarah R. Partan ◽  
Peter Otovic ◽  
Virginia L. Price ◽  
Scott E. Brown
Keyword(s):  
Temporal Structure ◽  
Adult Males ◽  
Anolis Sagrei ◽  
Species Identity ◽  
Social Responses ◽  
Nonbreeding Season ◽  
Putative Species ◽  
Brown Anole ◽  
Signature Pattern ◽  
High Degree

Abstract Signals used for species identity ought to be highly stereotyped so as to facilitate immediate recognition by con-specifics. It is surprising therefore to find variability in putative species signature displays. The brown anole Anolis sagrei has a high degree of variability in its signature bobbing display. In this study we collected descriptive data on variability in the temporal structure of wild brown anole bobbing patterns, finding that no two displays analyzed had the same temporal structure, and we also tested whether wild brown anoles prefer the signature display over an alternate display pattern by using mechanical robot playbacks in the field. As a response metric we assessed whether or not the lizards showed social responses (pushup, dewlap extension, or head-nod) in response to the robotic presentations. We found that the lizards responded slightly more to the signature than to the alternate pattern, providing support for the idea that despite the variability seen in displays, the signature pattern is meaningful to them. We tested two other independent variables: speed of the display and elevation of the robot during its display, neither of which was significant. Dewlap extensions were given predominantly by adult males and were more likely to be given in the breeding season than the nonbreeding season. Pushups and head-nods were given equally by males and a combined class of females and juveniles, and were not seasonal. Head-nods increased after the robot turned off, suggesting that they may be used in a conversational turn-taking style during communication.

Measurement Method Research on Inertial Parameters of Motor Assembly

2013 ◽  
Vol 437 ◽  
pp. 663-668
Author(s):  
Ling Sun ◽  
Peng Yu ◽  
Tong Zhang
Keyword(s):  
Measurement Method ◽  
Center Of Mass ◽  
Moment Of Inertia ◽  
Balance Method ◽  
Test Error ◽  
Inertial Parameters ◽  
Drive Motor ◽  
Weight Method ◽  
Mass Position

Inertial parameters of the motor assembly include its mass, CM (center of mass) position, moment of inertia and product of inertia. Taking one vehicle drive motor as the research object, its mass and CM position are measured by using weight method and moment balance method respectively. Its moment of inertia and product of inertia are measured by using three-wire pendulum. On the basis of analyzing the test error, this paper proposed specific measures to reduce the test error.

11 Dimensions, Mass, Location of the Center of Mass, and Moment of Inertia of the Segments of the Human Body

2016 ◽  
Author(s):  
Paul Brinckmann ◽  
Wolfgang Frobin ◽  
Gunnar Leivseth ◽  
Burkhard Drerup
Keyword(s):  
Human Body ◽  
Center Of Mass ◽  
Moment Of Inertia

scholarly journals Reactive Postural Responses to Continuous Yaw Perturbations in Healthy Humans: The Effect of Aging

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 63 ◽  
Author(s):  
Ilaria Mileti ◽  
Juri Taborri ◽  
Stefano Rossi ◽  
Zaccaria Del Prete ◽  
Marco Paoloni ◽  
...  
Keyword(s):  
Older Adults ◽  
Balance Control ◽  
Center Of Mass ◽  
Community Dwelling ◽  
Body Segments ◽  
Healthy Humans ◽  
Eyes Closed ◽  
Age Related ◽  
Postural Responses ◽  
Mass Displacement

Maintaining balance stability while turning in a quasi-static stance and/or in dynamic motion requires proper recovery mechanisms to manage sudden center-of-mass displacement. Furthermore, falls during turning are among the main concerns of community-dwelling elderly population. This study investigates the effect of aging on reactive postural responses to continuous yaw perturbations on a cohort of 10 young adults (mean age 28 ± 3 years old) and 10 older adults (mean age 61 ± 4 years old). Subjects underwent external continuous yaw perturbations provided by the RotoBit1D platform. Different conditions of visual feedback (eyes opened and eyes closed) and perturbation intensity, i.e., sinusoidal rotations on the horizontal plane at different frequencies (0.2 Hz and 0.3 Hz), were applied. Kinematics of axial body segments was gathered using three inertial measurement units. In order to measure reactive postural responses, we measured body-absolute and joint absolute rotations, center-of-mass displacement, body sway, and inter-joint coordination. Older adults showed significant reduction in horizontal rotations of body segments and joints, as well as in center-of-mass displacement. Furthermore, older adults manifested a greater variability in reactive postural responses than younger adults. The abnormal reactive postural responses observed in older adults might contribute to the well-known age-related difficulty in dealing with balance control during turning.

scholarly journals First record of the invasive Brown Anole, Anolis sagrei Duméril & Bibron, 1837 (Squamata: Iguanidae: Dactyloinae), in South America

Check List ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 2083 ◽  
Author(s):  
Luis Amador ◽  
Fernando Ayala-Varela ◽  
Andrea E. Nárvaez ◽  
Keyko Cruz ◽  
Omar Torres-Carvajal
Keyword(s):  
South America ◽  
Current Distribution ◽  
First Record ◽  
Anolis Sagrei ◽  
Lizard Species ◽  
Brown Anole

We report the first record of the invasive Brown Anole, Anolis sagrei Duméril & Bibron, 1837, in South America based on nine specimens from Samborondón, Guayas province, Ecuador. We also present some information related to the current distribution in Ecuador, and its possible impacts on native lizard species.

scholarly journals An incipient invasion of brown anole lizards (Anolis sagrei) into their own native range in the Cayman Islands: a case of cryptic back-introduction

2017 ◽  
Vol 19 (7) ◽  
pp. 1989-1998 ◽  
Author(s):  
Jason J. Kolbe ◽  
Johanna E. Wegener ◽  
Yoel E. Stuart ◽  
Ushuaia Milstead ◽  
Katherine E. Boronow ◽  
...  
Keyword(s):  
Cayman Islands ◽  
Native Range ◽  
Anolis Sagrei ◽  
Brown Anole

scholarly journals Quantification of vibrissal mechanical properties across the rat mystacial pad

2019 ◽  
Vol 121 (5) ◽  
pp. 1879-1895 ◽  
Author(s):  
Anne En-Tzu Yang ◽  
Hayley M. Belli ◽  
Mitra J. Z. Hartmann
Keyword(s):  
Mechanical Properties ◽  
Center Of Mass ◽  
Distal Region ◽  
Density Variation ◽  
Average Density ◽  
Proximal Region ◽  
Moment Of Inertia ◽  
Radius Of Gyration ◽  
Mass Moment ◽  
Mass Moment Of Inertia

Recent work has quantified the geometric parameters of individual rat vibrissae (whiskers) and developed equations that describe how these parameters vary as a function of row and column position across the array. This characterization included a detailed quantification of whisker base diameter and arc length as well as the geometry of the whisker medulla. The present study now uses these equations for whisker geometry to quantify several properties of the whisker that govern its mechanical behavior. We first show that the average density of a whisker is lower in its proximal region than in its distal region. This density variation appears to be largely attributable to the presence of the whisker cuticle rather than the medulla. The density variation has very little effect on the center of mass of the whisker. We next show that the presence of the medulla decreases the deflection of the whisker under its own weight and also decreases its mass moment of inertia while sacrificing <1% stiffness at the whisker base compared with a solid whisker. Finally, we quantify two dimensionless parameters across the array. First, the deflection-to-length ratio decreases from caudal to rostral: caudal whiskers are longer but deflect more under their own weight. Second, the nondimensionalized radius of gyration is approximately constant across the array, which may simplify control of whisking by the intrinsic muscles. We anticipate that future work will exploit the mechanical properties computed in the present study to improve simulations of the mechanosensory signals associated with vibrissotactile exploratory behavior. NEW & NOTEWORTHY The mechanical signals transmitted by a whisker depend critically on its geometry. We used measurements of whisker geometry and mass to quantify the center of mass, mass moment of inertia, radius of gyration, and deflection under gravity of the whisker. We describe how variations in these quantities across the array could enhance sensing behaviors while reducing energy costs and simplifying whisking control. Most importantly, we provide derivations for these quantities for use in future simulation work.

scholarly journals Development of the squamate naso-palatal complex: detailed 3D analysis of the vomeronasal organ and nasal cavity in the brown anole Anolis sagrei (Squamata: Iguania)

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Paweł Kaczmarek ◽  
Katarzyna Janiszewska ◽  
Brian Metscher ◽  
Weronika Rupik
Keyword(s):  
Nasal Cavity ◽  
Vomeronasal Organ ◽  
Mass Separation ◽  
3D Analysis ◽  
Developmental Phase ◽  
Anolis Sagrei ◽  
Lacrimal Duct ◽  
Adult Morphology ◽  
Brown Anole ◽  
Frontonasal Mass

Abstract Background Despite the diverse morphology of the adult squamate naso-palatal complex – consisting of the nasal cavity, vomeronasal organ (VNO), choanal groove, lacrimal duct and superficial palate – little is known about the embryology of these structures. Moreover, there are no comprehensive studies concerning development of the nasal cavity and VNO in relation to the superficial palate. In this investigation, we used X-ray microtomography and histological sections to describe embryonic development of the naso-palatal complex of iguanian lizard, the brown anole (Anolis sagrei). The purpose of the study was to describe the mechanism of formation of adult morphology in this species, which combines the peculiar anole features with typical iguanian conditions. Considering the uncertain phylogenetic position of the Iguania within Squamata, embryological data and future comparative studies may shed new light on the evolution of this large squamate clade. Results Development of the naso-palatal complex was divided into three phases: early, middle and late. In the early developmental phase, the vomeronasal pit originates from medial outpocketing of the nasal pit, when the facial prominences are weakly developed. In the middle developmental phase, the following events can be noted: the formation of the frontonasal mass, separation of the vestibulum, appearance of the lacrimal duct, and formation of the choanal groove, which leads to separation of the VNO from the nasal cavity. In late development, the nasal cavity and the VNO attain their adult morphology. The lacrimal duct establishes an extensive connection with the choanal groove, which eventually becomes largely separated from the oral cavity. Conclusions Unlike in other tetrapods, the primordium of the lacrimal duct in the brown anole develops largely beyond the nasolacrimal groove. In contrast to previous studies on squamates, the maxillary prominence is found to participate in the initial fusion with the frontonasal mass. Moreover, formation of the choanal groove occurs due to the fusion of the vomerine cushion to the subconchal fold, rather than to the choanal fold. The loss or significant reduction of the lateral nasal concha is secondary. Some features of anole adult morphology, such as the closure of the choanal groove, may constitute adaptations to vomeronasal chemoreception.

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