A nitride semiconductor light-emitting device includes an emission layer formed on a substrate, and the emission layer includes a quantum well layer of GaN1-x\u2212y\u2212zAsxPySbz containing Al. The condition is sampled at a variable periodic interval, and the event reported during intervals when a change in the condition is determined. The first and second outer surfaces are adapted to contact a medium at the nip. epidermidis, or related staphylococci that express a \u03b3PGA polypeptide.