Defective recombinant viruses containing an inserted gene coding for all or part of lecithin-cholesterol acyltransferase or a variant thereof, pharmaceutical compositions containing said viruses, and the use thereof for treating or preventing dyslipoproteinaemia-related diseases, are disclosed. The shell has a corrugated sidewall which permits axial deformation as the compression device is heated. A slide gate arranged at the bin outlet modulates the discharge of material from the bin. A one-way valve located in the gas conduit allows the passage of gas through the conduit from the conduit inlet to the conduit outlet when a predetermined pressure differential between the first and second locations of the pumping channel is generated during roughing when the scroll inlet is at or close to atmosphere. The trajectory of the beam can be measured efficiently and accurately using beam sensors attached to a beam assembly, where a model maps the beam sensor locations to a trajectory of the beam.