The present invention relates to compositions and methods for the detection and characterization of interfering RNAs such as micro RNAs and small interfering RNAs and other short nucleic acid molecules. A reduced scattering coefficient and an absorption coefficient are determined for the tissue, with the result that an effective path length can be determined. The object store associates each data object of a plurality of data objects with a unique key value. The strut is adjustable and is deformable to absorb an impact to the exterior of the skirt panel.