Systems and methods for facilitating emergency call service are provided. A pair of first line members is attached to the canopy, the pair of first line members extending in a substantially radial direction away from the skirt towards a center of the canopy. While syt I needs gangliosides for BoNTB binding, syt II can bind to BoNTB in the absence of gangliosides. The acoustic material can be a phononic crystal that undergoes a change in its acoustic bandgap after being subjected to electromagnetic radiation.