A drive device for machine auxiliary units for transmitting a machine drive force from a machine to the machine auxiliary units by a belt. In one aspect, methods and devices of the present invention are directed to modulating the efficacy of photobiostimulation in a target region by controlling the temperature in the region andor its surrounding volume. The invention also encompasses immunogenic compositions containing gp120 polypeptides or polynucleotides and their use in eliciting a gp120-specific immune response. Each one of the ends of the first arms forms a folding-back section, and a second arm is formed at the end of the folding-back section.