An injectable amino-acid composition acts naturally to fuel collagen synthesis, which retards aging and helps to clear cellular decay while accelerating the cell division that promotes healthy, younger looking skin. The first and second flow paths cause air in a housing that accommodates the heating device to flow to the outside. The tiles include drive tiles that are pivotal between nominal and dilated positions and driven tiles that intermesh with the drive tiles and shift with the drive tiles between the positions. The second body portion can be further rotated to a second angle when the second body portion bears a thrust force at the first angle. The method includes grouping a plurality of customer-agent interactions into a category upon identifying one or more predetermined common characteristics in the customer-agent interactions and linking at least two of said customer-agent interactions to form a chain of interactions upon identifying a condition that matches a predetermined rule defining the chain.