One Line or Two? Perspectives on Piecewise Regression

Sometimes we are faced with data that could reasonably be represented either as a single line, or as two or more line segments. How do we identify the best breakpoint(s), and decide how many segments are ''really'' present? Most of us are taught to distrust piecewise regression, because it can be easily abused. The best method for identifying the breakpoint varies according to specifics of the data; for example, the minimum sum of squares method excels for ''well-behaved'' data. In some cases, hidden Markov methods are more likely to succeed than are more ''obvious'' methods. Likewise, the most appropriate method for deciding between one or two lines depends on your expectations and understanding of the data: an unexpected break requires more justification than an expected one, and some decision criteria (e.g., the Akaike Information Criterion) are less strict than others (e.g., the Bayesian Information Criterion). This presentation will review some options and make specific, practical recommendations

Information and digital literacies; a review of concepts

A detailed literature reviewing, analysing the multiple and confusing concepts around the ideas of information literacy and digital literacy at the start of the millennium. The article was well-received, and is my most highly-cited work, with over 1100 citations

In vivo and in vitro degradation of poly[50/50 (85/15L/D)LA/ε-CL], and the implications for the use in nerve reconstruction

Nerve guides can be used for the reconstruction of peripheral nerve defects. After serving their function, nerve guides should degrade. p[50/50 (85/15L/D)LA/ε-CL] degrades completely within 1 year without the formation of a slow degrading crystalline fraction. Although the tensile strength (TS) of a p[50/50 (85/15L/D)LA/ε-CL] nerve guide is negligible after 2 months, nerve regeneration across a 1-cm gap in the sciatic nerve of the rat is faster and qualitatively better than after reconstruction using autologous nerve grafts. During degradation p[50/50 (85/15L/D)LA/ε-CL] swells, especially during the first 3 months. This can have a negative influence on the regenerating nerve. p[50/50 (85/15L/D)LA/ε-CL] nerve guides could only be used in the clinical situation in case of short nerve gaps (several mm) in small nerves (for instance digital nerves). Refinements will be needed to successfully reconstruct longer nerve gaps (several cm)