Combinable and interchangeable water features used on a standard universal mounting system to create the desired color, style, jet, directional flow, filter, light, return fittings, or other water feature for a pool or spa. The method comprises contacting the mammalian cells with a therapeutically effective amount of a nitric oxide mediator selected from the group consisting of pyruvates, pyruvate precursors, -keto acids having four or more carbon atoms, precursors of -keto acids having four or more carbon atoms, and the salts thereof. The method could be used as a stand-alone method or as a post-processing method to enhance and classify outputs of a high-sensitivity low-specificity method to eliminate false positives. The present invention is also directed to methods and systems useful for writing and reading the molecular-based memory devices. The light emitting device includes: a light emitting structure layer including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; an oxide protrusion disposed on at least a portion of the second conducive semiconductor layer; and a current spreading layer on the second conductive semiconductor layer and the oxide protrusion.