In this note we study a metric invariant of a knot K embedded in R 3. This metric invariant depends on a complex parameter s. It is defined as a double integral using the parameterization x → γ(x) of K by the arc-length parameter x: B K (s) = K×K ||γ(x) − γ(y)|| s dxdy (1) where dx, dy denote the arc-lengths on the two copies of K. Clearly the function (x, y) → ||γ(x) − γ(y)|| s is continuous f...

The left ventricular dimension and posterior wall dynamics were studied by computer assisted analysis of M mode echocardiography in 25 normal children (group 1) and 32 transfusion dependent children with beta thalassaemia major who had no evidence of heart failure (group 2). Twenty seven of those in group 2 remained well but five died of cardiac decompensation within 12 months. Compared with gr...

Transmission is a fundamental step in the life cycle of every parasite but it is also one of the most challenging processes to model and quantify. In most host-parasite models, the transmission process is encapsulated by a single parameter β Many different biological processes and interactions, acting on both hosts and infectious organisms, are subsumed in this single term. There are, however, ...