Quasistatic crack growth based on viscous approximation: a model with branching and kinking.

Employing the technique of vanishing viscosity and time rescaling, we show the existence of quasistatic evolutions of cracks in brittle materials in the setting of antiplane shear. The crack path is not prescribed a priori and is chosen in an admissible class of piecewise regular sets that allows for branching and kinking

Studies in the flora of Arabia: XXX. A synopsis of the native and naturalised species of Senna (Leguminosae: Caesalpinioideae) in the Arabian Peninsula.

A synopsis of the native and naturalised species of Senna (Leguminosae: Caesalpinioideae) in the Arabian Peninsula is provided. Nine species are recognised. A key to the species is presented. For each species the accepted name with selected synonymy is given, followed by a diagnostic morphological description, the geographical distribution, details of habitat preference, and citation of specimens studied. Preliminary regional conservation assessments are given for all species