An antenna adapter, for an antenna with a recessed adapter seat with a feed bore is provided as a base with a feed aperture, the base dimensioned to seat within the adapter seat, the feed aperture aligned coaxial with the feed bore. In one embodiment, a method of training a classifier for a smoke detector comprises inputting sensor data from a plurality of tests into a processor. The methods involve feeding LCP supplemented, nutrient-enriched formulas for an extended feeding regimen, typically until at least 3 months corrected age, preferably to 6 or even 12 months CA. The pole is magnetically coupled to the magnetic element so that a magnetic flux is generated in the air gap substantially orthogonal to the axis of motion.