scholarly journals Three-dimensional launch kinematics in leaping, parachuting and gliding squirrels

2002 ◽  
Vol 205 (16) ◽  
pp. 2469-2477 ◽  
Author(s):  
Richard L. Essner
Keyword(s):  
Significant Variation ◽  
High Speed ◽  
Three Dimensional ◽  
Tamiasciurus Hudsonicus ◽  
Glaucomys Volans ◽  
Tamias Striatus ◽  
High Speed Video ◽  
Primary Means ◽  
Hindlimb Kinematics

SUMMARY Leaping, parachuting and gliding are the primary means by which arboreal squirrels negotiate gaps in the canopy. There are notable differences among the three locomotor modes with respect to mid-air postures and aerodynamics,yet it is unclear whether variation should also be expected during the launch phase of locomotion. To address this question, launch kinematic profiles were compared in leaping (Tamias striatus), parachuting (Tamiasciurus hudsonicus) and gliding (Glaucomys volans) squirrels. Animals were filmed launching to the ground from a platform using high-speed video. Statistical comparisons among taxa indicated that only six out of 23 variables were significantly different among the three species. Two were associated with tail kinematics and were a consequence of tail morphology. Two were forelimb-related and discriminated gliding from non-gliding taxa. The remaining two variables were performance attributes, indicating significant variation among the species in take-off velocity and horizontal range. The absence of significant differences in hindlimb kinematics indicates that propulsion is essentially identical in leaping, parachuting and gliding squirrels.

Study on Magnetic Barrel Machine Equipped with Three-Dimensional Arrangement of Magnets

2007 ◽  
Vol 329 ◽  
pp. 761-766 ◽  
Author(s):  
Y. Zhang ◽  
Masato Yoshioka ◽  
Shin-Ichiro Hira
Keyword(s):  
High Speed ◽  
Permanent Magnets ◽  
Three Dimensional ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera ◽  
The Media ◽  
Set Up

At present, a commercially available magnetic barrel machine equipped with permanent magnets has some faults arising from constructional reason. That is, grinding or finishing ability is different from place to place in the machining region, resulting in the limitation on the region we can use in the container of workpieces. Therefore, in this research, authors made the new magnetic barrel machine equipped with three dimensional (3D) magnet arrangement to overcome these faults. The grinding ability of the new 3D magnetic barrel machine converted was experimentally examined, and compared with that of the traditional magnetic barrel machine. As a result, it was shown that we can use much broader region in the new 3D machine. It was also shown that the grinding ability became higher. The distribution of barrel media in action was recorded by means of a high speed video camera. It was clarified that the media rose up higher and were distributed more uniformly in the container by the effect of the magnet block newly set up. It was supposed that this must be the reason for the above-mentioned improvement of grinding ability.

scholarly journals High-Speed Video-Oculography for Measuring Three-Dimensional Rotation Vectors of Eye Movements in Mice

PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0152307 ◽  
Author(s):  
Takao Imai ◽  
Yasumitsu Takimoto ◽  
Noriaki Takeda ◽  
Atsuhiko Uno ◽  
Hidenori Inohara ◽  
...  
Keyword(s):  
Eye Movements ◽  
High Speed ◽  
Three Dimensional ◽  
Video Oculography ◽  
High Speed Video ◽  
Rotation Vectors

LED-Based 3-DMD Volumetric 3D Display

2014 ◽  
Vol 596 ◽  
pp. 442-445
Author(s):  
Chang Long Jing ◽  
Qi Bin Feng ◽  
Ying Song Zhang ◽  
Guang Lei Yang ◽  
Zhi Gang Song ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
High Speed ◽  
Three Dimensional ◽  
Human Vision ◽  
3D Display ◽  
Video Projector ◽  
High Speed Video ◽  
University Of Technology ◽  
Measurement Results ◽  
Main Components

A solid-state volumetric true 3D display developed by Hefei University of Technology consists of two main components: a high-speed video projector and a stack of liquid crystal shutters. The shutters are based on polymer stabilized cholesteric texture material, presenting different states that can be switched by different voltage. The high-speed video projector includes LED-based light source and tree-chip digital micro-mirror devices modulating RGB lights. A sequence of slices of three-dimensional images are projected into the liquid crystal shutters locating at the proper depth, forming a true 3D image depending on the human vision persistence. The prototype is developed. The measurement results show that the screen brightness can reach 149 nit and no flickers can be perceived.

Three-dimensional analysis of eye movements using four times high-speed video camera

2005 ◽  
Vol 32 (2) ◽  
pp. 107-112 ◽  
Author(s):  
Toshiaki Yagi ◽  
Yasuo Koizumi ◽  
Mio Aoyagi ◽  
Maki Kimura ◽  
Kazuki Sugizaki
Keyword(s):  
Eye Movements ◽  
Dimensional Analysis ◽  
High Speed ◽  
Three Dimensional ◽  
Video Camera ◽  
High Speed Video ◽  
High Speed Video Camera

Effects of incline on speed, acceleration, body posture and hindlimb kinematics in two species of lizard Callisaurus draconoides and Uma scoparia.

1998 ◽  
Vol 201 (2) ◽  
pp. 273-287 ◽  
Author(s):  
D J Irschick ◽  
B C Jayne
Keyword(s):  
Related Species ◽  
High Speed ◽  
Stride Length ◽  
Body Posture ◽  
Level Surface ◽  
Locomotor Performance ◽  
Sandy Desert ◽  
Closely Related Species ◽  
High Speed Video ◽  
Hindlimb Kinematics

We examined the effects of incline on locomotor performance and kinematics in two closely related species of iguanian lizards that co-occur in sandy desert habitats. Callisaurus draconoides differs from Uma scoparia of equal snout-vent length by being less massive and having greater limb and tail lengths. We analyzed high-speed video tapes of lizards sprinting from a standstill on a sand-covered racetrack which was level or inclined 30 degrees uphill. C. draconoides sprinted significantly faster than U. scoparia on both level and uphill sand surfaces, although U. scoparia is considered to be more specialized for sandy habitats. Initial accelerations (over the first 50 ms) did not differ significantly either between species or between inclines within species. Overall, the effects of incline were more pronounced for C. draconoides than for U. scoparia. For example, the incline caused a significant decrease in the maximum stride length of C. draconoides but not in that of U. scoparia. For C. draconoides, uphill stride durations were significantly shorter than on the level surface, and this partially compensated for the effects of shorter uphill stride lengths on velocity. C. draconoides ran bipedally more often than did U. scoparia on both the level and uphill surfaces.

scholarly journals Indirect evidence for elastic energy playing a role in limb recovery during toad hopping

2014 ◽  
Vol 10 (7) ◽  
pp. 20140418 ◽  
Author(s):  
Ariela Schnyer ◽  
Mirialys Gallardo ◽  
Suzanne Cox ◽  
Gary Gillis
Keyword(s):  
Elastic Energy ◽  
High Speed ◽  
Muscle Power ◽  
Rapid Development ◽  
Indirect Evidence ◽  
Knee Extension ◽  
Elastic Recoil ◽  
High Speed Video ◽  
Hindlimb Kinematics ◽  
Limb Flexion

Elastic energy is critical for amplifying muscle power during the propulsive phase of anuran jumping. In this study, we use toads ( Bufo marinus ) to address whether elastic recoil is also involved after take-off to help flex the limbs before landing. The potential for such spring-like behaviour stems from the unusually flexed configuration of a toad's hindlimbs in a relaxed state. Manual extension of the knee beyond approximately 90° leads to the rapid development of passive tension in the limb as underlying elastic tissues become stretched. We hypothesized that during take-off, the knee regularly extends beyond this, allowing passive recoil to help drive limb flexion in mid-air. To test this, we used high-speed video and electromyography to record hindlimb kinematics and electrical activity in a hindlimb extensor (semimembranosus) and flexor (iliofibularis). We predicted that hops in which the knees extended further during take-off would require less knee flexor recruitment during recovery. Knees extended beyond 90° in over 80% of hops, and longer hops involved greater degrees of knee extension during take-off and more intense semimembranosus activity. However, knee flexion velocities during recovery were maintained despite a significant decrease in iliofibularis intensity in longer hops, results consistent with elastic recoil playing a role.

scholarly journals High Prevalence of Borrelia mayonii (Spirochaetales: Spirochaetaceae) in Field-Caught Tamias striatus (Rodentia: Sciuridae) From Northern Wisconsin

2021 ◽  
Author(s):  
Patricia N Siy ◽  
Ryan T Larson ◽  
Tela E Zembsch ◽  
Xia Lee ◽  
Susan M Paskewitz
Keyword(s):  
Ixodes Scapularis ◽  
Tamiasciurus Hudsonicus ◽  
Infection Prevalence ◽  
Glaucomys Volans ◽  
Blarina Brevicauda ◽  
Tamias Striatus ◽  
Napaeozapus Insignis ◽  
High Prevalence ◽  
Sorex Cinereus ◽  
Eastern Chipmunks

Abstract Borrelia mayonii is a recently discovered bacterial spirochete that causes Lyme disease and is transmitted by the blacklegged tick, Ixodes scapularis Say (Acari: Ixodidae). To date, B. mayonii has been isolated from two vertebrate host species in Minnesota: field-caught white-footed mice (Peromyscus leucopus Rafinesque; Rodentia: Cricetidae) and American red squirrel (Tamiasciurus hudsonicus Erxleben). Here, we describe the first detection of B. mayonii in field-caught eastern chipmunks (Tamias striatus L. (Rodentia: Cricetidae)) from northern Wisconsin. During our study, we captured 530 unique small mammals and found an infection prevalence of 23.50% in field-caught eastern chipmunks (4/17) and 1.19% in Peromyscus spp. (5/420). Mean larval and nymphal burdens were determined for captured Blarina brevicauda (0, 0), Glaucomys volans (0.29, 0.14), Myodes gapperi (0.27, 0), Napaeozapus insignis (0, 0.25), Peromyscus spp. (1.88, 0.11), T. striatus (1.06, 0.65), and Sorex cinereus (0.09, 0). The high B. mayonii infection prevalence in eastern chipmunks suggests that the species may be an important reservoir for B. mayonii in the Upper Midwest.

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