MIXING OF ISOTOPE SIGNALS DUE TO SAMPLING AND PHYSIOLOGY: A CASE STUDY IN DECONVOLUTION
We use the example of hair, which grows continuously and records movement or diet history. In some studies hair is "bundled" by aligning hairs prior to sampling to optimize the sample size needed for isotope analysis; while this allows a higher temporal resolution, the differential growth rate and stage of growth (anagen, catagen, telogen) of hair results in a "mixing" of the temporal signal. We present an inverse method to deconvolve this time dependent signal and to suppress this sampling bias. Application of a physiological model for isotope turnover then allows calculation of the "equilibrium state" for comparison to "equilibrium maps".
We present an example of a recently solved missing persons case where greater definition of the potential search areas was defined after application of these methods.