Quantification of changes in the macromolecular constituents of tissue is a major theme in biomedical magnetic resonance (MR). In many cases, constituents can only be distinguished through their differing water transverse relaxation times, instead of by frequency differences as is more familiar in MR spectroscopy. However, this requires implementation of multiexponential transverse relaxation analysis (METRA), a special case of the inverse Laplace transform, a notoriously ill-posed and unstable inverse problem.

Chemical and physical processes such as reaction dynamics and the transport of molecular
excitations have been occurring on earth for the last few billions of years. In time, reactive
processes led to the appearance of life through the formation of amino acids, nucleic acids and
eventually, proteins, RNA and DNA. Photosynthetic bacteria, the first recorded forms of life on
earth, have evolved biologically over the last three billion years. During this evolution,

Artificial spin ice consists of arrays of lithographically fabricated single-domain ferromagnetic elements, arranged in different geometries such that the magnetostatic interactions between the moments are frustrated. Because we can both design the lattice geometries and probe the individual moments, these systems allow us to study the accommodation of frustration with exquisite detail and flexibility.