Abstract: Disclosed is a Lightweight low-cost solar concentrator comprising two sheets which are connected or sealed to each other on their outer periphery to define a gasproof chamber which is inflated with air or gas (5) in order to form the inflated mirror. One sheet is transparent (1) for sunlight (3) and the other sheet has a reflecting mirror-like surface (2). The periphery of the two connected sheets is fixed to a rigid support or envelopes it. The rigid support, such as a support frame (6), which is further fixed to a mirror support structure (7), defines the outline of the inflatable mirror and provides stability. For a defined adjustment of the pressure in the air or gas (5) which is enclosed in the gasproof chamber means for inflating or deflating the mirror (4) and a device for the generation of a defined pressure in the air or gas (72) are provided.

Abstract: A nucleic acid construct comprising at least two copies of a nucleic acid sequence encoding an autocatalytic peptide cleavage site is disclosed. This site preferably comprises the amino acid sequence DX(D,E)XNPGP. A method of exposing an animal to an antigenic amino acid sequence is also disclosed.