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This is the homepage of the Georgia Tech node of the international Physics of Living Systems (PoLS) student research network. The goal of this network is to foster interaction and collaboration among PoLS researchers within Georgia Tech and across institutes. Six core faculty members from the Schools of Biology, Physics, and Mechanical Engineering lead the Georgia Tech PoLS node.

The NSF Physics of Living Systems program sponsors research "exploring the most fundamental physical processes that living systems utilize to perform their functions in dynamic and diverse environments." The aim of PoLS research is to advance our understanding of the living world in a quantitative way, while also seeking to expand the intellectual range of physics paying through the lessons learned from the biological study.

At Georgia Tech PoLS research is carried out across a diversity of biological scales: single-molecule ⇒ cellular ⇒ organismal biophysics. Both theoretical and experiment biophysics research is conducted by core faculty members and affiliated faculty.

Announcements

 

STABILIZING FALLS IN CONFINED ENVIRONMENTS

Nick Gravish

Subterranean animals must rapidly navigate unpredictable and perilous underground environments. Nests of the fire ant \em{Solenopsis invicta} (average body length 0.35  \pm 0.05 cm) consist of a subterranean network of large chambers and tunnels which can reach 2 meters into the earth and house up to 250,000 workers. Laboratory investigations of fire ants reveal that digging workers typically climb up and down tunnels slightly wider than the largest ant hundreds of times per hour. However the principles of locomotion within confined environments such as tubes have been largely unexplored. We hypothesize that the ability to engineer underground habitats provides opportunities to facilitate movement. We conducted laboratory experiments to monitor upward and downward tube climbing of isolated fire ant workers. Fire ants were challenged to climb in 9.4 cm long glass tunnels (diameter D = 0.1 – 0.9 cm) that separated a nest from an open arena with food and water. During ascending and descending climbs we induced falls by a rapid, short, translation of the tunnels downward. We monitored induced falls over 24 hours in groups from five separate colonies. The tunnel diameter has a significant affect on the ability of ants to rapidly recover from perturbations. Falls in smaller diameter tunnels were arrested through the use of rapid jamming of limbs, body and antennae against the tunnel walls, arresting in as low 30 ms. Falls in larger diameter tunnels were not arrested. We find that the transition to stable fall arrest occurs in tunnels equal to 1.4 BL. This tunnel size is  comparable to the natural tunnel diameter found near nest entrances. Our data indicates that fire ants moving through natural tunnels can employ antennae, limbs, and body to rapidly stabilize falls.



Core faculty list

Core Faculty


PI

Website

Contact


Daniel I. Goldman

http://crablab.gatech.edu

daniel.goldman[at]physics.gatech.edu


Jennifer Curtis

http://curtisresearch.gatech.edu/

jennifer.curtis[at]physics.gatech.edu


Kurt Wiesenfeld

Department profile

kurt.wiesenfeld[at] physics.gatech.edu


Joshua Weitz

http://www.physics.gatech.edu/user/joshua-weitz

jsweitz[at] gatech.edu


Harold Kim

http://www.physics.gatech.edu/user/harold-kim

harold.kim [at] physics.gatech.edu


David Hu

http://www-old.me.gatech.edu/hu/

hu [at] me.gatech.edu



Support
This network is supported by the NSF Physics of Living Systems program within the physics division. The student research network is a part of the NSF Science across virtual institutes program to encourage interaction among researchers across many universities.