Experimental research

 

Experimental data represent the key to confirm or deny theoretical hypotheses and numerical models. For this reason they play a central role in RG.BIO project. At CoBBS Lab we have a long and solid experience in 3D experiments and 3D tracking of bird flocks and insect swarms, but with RG.BIO we aim to face new experimental challenges to meet the theoretical requirements of the new RG approach. We aim to develop a novel dynamic 3D stereo camera system to overcome the limitation of the standard static set-up and acquire long lasting 3D trajectories, which are essential to compute spatio-temporal correlation functions in high polarized systems as starling flocks and hence to test dynamic scaling, speed waves propagation and systems response to external stimuli. Moreover we aim to perform experimental campaigns on bird flocks, insect swarms and cell colonies to test and corroborate the search for universality of the RG theory.

A novel co-moving camera 3D stereo system

We developed a novel co-moving 3D system, i.e. a system of three high-speed synchronized cameras, inspired by the human ability to follow the trajectory of a target with a coordinate movement of the eyes: cameras are coupled with rotational stages that drive a controlled rotation of all the cameras in the same direction and at the same rotational speed, in this way dynamically adapting the field of view to the motion of the targets. With the rotation of the cameras we overcome the limitations of standard static systems that restrict the duration of the collected data to the short interval of time in which targets are in the cameras common field of view.

With a full-fledged experimental data-taking campaign on starling flocks we could check the feasibility of the experiment with the co-moving set-up, which proved to be easy to mount and easy to calibrate in the field. The data collected in the field confirmed that with the co-moving strategy we can actually track the flocks significantly longer than with a standard static system, as we show in the video below, where we compare in terms of time duration the trajectories acquired with the dynamic system, highlighted in light blue, and the trajectories that we would have acquired using a standard static system, highlighted in red.

Universality

In order to explore new universality classes, we need to have access to data on a great variety of biological systems, some already well known from the CoBBS Lab, others new.

Bird flocks. The project aims to study and compare two different systems: starlings (Sturnus vulgaris) that display high-polarized collective motion and Vaux’s swifts (Chaetura vauxi) that display a peculiar milling collective motion. We collect data on starling flocks in Rome (Italy), where starlings are used to migrate during winter and data on Vaux’s swifts in Portland (Oregon), in collaboration with Portland State University, where swifts are used to roost in September during their migration.

Insect swarms. The projects aims to study the collective behavior in large swarms of midges (Diptera Chironomidae) in the urban environment of Rome where they are ubiquitous during summer and fall, and of malaria mosquitoes (Anopheles gambiae) at the Mosquitoes Confined Facility (MCF), in collaboration with the University of Perugia.

Cell colonies. The project aims to study the formation and collective behavior of clonal colonies in vitro, in collaboration with the Department of Molecular Medicine of Sapienza University of Rome, acquiring time-lapse sequences of the colonies starting from a single clonogenic human bone marrow stromal cell up to a period of 21 days.