Effect of mechanical interactions on the scaling of fracture length and aperture

Article Abstract:

Understanding the mechanical processes involved in fracturing is important for a number of geological applications, such as underground pollution and mining. Observations of populations of tensile fractures in Northern Iceland show that the fracturing process is non-universal and is scale-dependent. Simulations of fracturing show that recourse to multiple growth mechanisms is unnecessary to explain the Iceland observations. The fracturing process and its non-universality shows that larger fractures induce stress perturbations that influence the smaller fractures.

Observations, Natural history, Iceland, Fracture mechanics, Rock mechanics

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The structural basis of Arfaptin-mediated cross-talk between Rac and Arf signalling pathways

Article Abstract:

Research mapping the cross-talk between Arf and Rac is presented. Particular attention is given to the X-ray structure of Arfaptin and to the structure of Afaptin with Rac bound to GDP or the GMPPNP. It is demonstrated that the synergy between Arf and Rho is mediated by Arfaptin.

Cell metabolism

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Structural basis for the fracture toughness of the shell of the conch Strombus gigas

Article Abstract:

Research concerning the mechanical toughness and strength of the shell of the conch Strombus gigas is presented. The use of transmission electron microscopy to study catastrophic shell fracture is discussed.

Design and construction, Letter to the Editor, Queen conch, Shells

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