Strategic Escape Direction: Orientation, Turning, and Escape Trajectories of Zebra-Tailed Lizards (Callisaurus draconoides)

Ethology ◽  
2016 ◽  
Vol 122 (7) ◽  
pp. 542-551 ◽  
Author(s):  
William E. Cooper ◽  
Wade C. Sherbrooke
Keyword(s):  

1985 ◽  
Vol 53 (1) ◽  
pp. 252-265 ◽  
Author(s):  
L. A. Miller ◽  
G. Hagiwara ◽  
J. J. Wine

We have used electrophysiological techniques to document segmental differences in the pathways between the giant, escape command axons, lateral giants (LG) and medial giants (MG), and the nongiant, fast flexor (FF) motoneurons. We found no difference in the input from LG and MG axons to FF motoneurons in the posterior (4th and 5th) ganglia. Since flexor motor output in these segments would be inconsistent with the LG-evoked behavior pattern, this finding was puzzling. Electromyographic (EMG) recordings during escape responses by intact unrestrained animals confirm that the FF muscles innervated by the posterior ganglia are not excited during LG-mediated tailflips, but are excited during MG-mediated tailflips. In the 2nd and 3rd ganglia, the command axons fire the FF motoneurons with high probability, in part via electrical excitatory postsynaptic potentials (EPSPs) from premotor neurons, the segmental giants (SG). In the 4th and 5th ganglia, the equivalent pathway is much less effective. Single, directly elicited impulses in SGs in ganglia 2 and 3 fire their respective FF motoneurons with high probability, while those in ganglia 4 and 5 rarely fire FF motoneurons. The command axons fire the SGs reliably in all segments. The amplitude of the SG-evoked EPSP in FF motoneurons is significantly smaller in posterior vs. anterior ganglia. For technical reasons, we are unable to present conclusive evidence on ganglionic variations in FF-motoneuron thresholds. The FF motoneurons receive additional excitatory input from intersegmental interneurons recruited by the command neurons. Motoneurons in ganglia 4 and 5 are excited by large interneurons that do not synapse on motoneurons in ganglia 2 and 3, but this additional input is not sufficient to compensate for the weaker effect of SG input. Unlike the all-or-none segmental differences demonstrated previously for the LG-to-motor giant pathway (24), the SG-to-FF pathway changes gradually, retains significant though subthreshold strength in posterior ganglia, and is common to both LGs and MGs. These features provide opportunities for variation in the spatial patterning of flexion and in the resulting escape trajectories.



2015 ◽  
pp. 199-224 ◽  
Author(s):  
Paolo Domenici ◽  
Graeme D. Ruxton
Keyword(s):  


Author(s):  
Keita TANAKA ◽  
Jun'ichiro KAWAGUCHI


2020 ◽  
Vol 67 (4) ◽  
pp. 1374-1390
Author(s):  
Lorenzo Casalino ◽  
Gregory Lantoine

AbstractLunar gravity assist is a means to boost the energy and C3 of an escape trajectory. Trajectories with two lunar gravity assists are considered and analyzed. Two approaches are applied and tested for the design of missions aimed at Near-Earth asteroids. In the first method, indirect optimization of the heliocentric leg is combined to an approximate analytical treatment of the geocentric phase for short escape trajectories. In the second method, the results of pre-computed maps of escape C3 are employed for the design of longer Sun-perturbed escape sequences combined with direct optimization of the heliocentric leg. Features are compared and suggestions about a combined use of the approaches are presented. The techniques are efficiently applied to the design of a mission to a near-Earth asteroid.



2009 ◽  
Vol 29 (22) ◽  
pp. 7181-7190 ◽  
Author(s):  
D. Booth ◽  
B. Marie ◽  
P. Domenici ◽  
J. M. Blagburn ◽  
J. P. Bacon


2010 ◽  
Vol 16 (6) ◽  
pp. 364-371
Author(s):  
Laurie St. Julien

Why would a person who is terrified of cockroaches use them in a math lesson? The idea for this investigation did not occur to me until I read a newspaper article that described Italian scientist Paolo Domenici's research about cockroaches' escape trajectories. In particular, he found that cockroaches have preferred escape trajectories of 90, 120, 150, and 180 degrees from the source of danger (Domenici et al. 2008). Because this real-world information presents a unique problem-solving context for fifth graders to explore angles formed by clockwise and counterclockwise rotations, I overcame my fear of the creatures to develop this investigation.



Author(s):  
Makoto Horikawa ◽  
Takanao Saiki ◽  
Yasuhiro Kawakatsu ◽  
Hiroaki Yoshimura


1999 ◽  
Vol 22 (5) ◽  
pp. 637-642 ◽  
Author(s):  
Lorenzo Casalino ◽  
Guido Colasurdo ◽  
Dario Pastrone






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