Chiral cosmic strings are produced naturally at the end of inflation in supersymmetric models where the symmetry is broken via a D-term. Consequently in such theories, where both inflation and cosmic strings contribute to the density and CMBR (microwave background) perturbations, it is necessary to understand the evolution of chiral cosmic string networks. We study the dynamics of chiral cosmic strings in Minkowski space and comment on a number of differences with those of Nambu-Goto strings. To do this we follow the work of Carter and Peter who showed that the equations of motion for chiral cosmic strings reduce to a wave equation and two constraints, only one of which is different from the familiar Nambu-Goto constraints. We study chiral string loop solutions consisting of many harmonics and determine their self-intersection probabilities, and comment on the possible cosmological significance of these results.

In theories with flat directions containing vortices, such as supersymmetric QED, there is a vacuum selection effect in the allowed asymptotic configurations. We explain the role played by gauge fields in this effect and give a simple criterion for determining what vacua will be chosen, namely those that minimise the vector mass. We then consider the effect of vacuum selection on stable (BPS) non-topological vortices in a simple Abelian model with N = 2 supersymmetry which occurs as a low energy limit of Calabi-Yau compactifications of type II superstrings. In this case the magnetic flux spreads over an arbitrarily large area. We discuss the implications for cosmology and for superstring inspired magnetic confinement scenarios.

It is shown that racetrack inflation can be implemented in a moduli stabilisation scenario with a supersymmetric uplifting D-term. The resulting model is completely described by an effective supergravity theory, in contrast to the original racetrack models. We study the inflationary dynamics and show that the gaugino condensates vary during inflation. The resulting spectral index is n s ≈ 0.95 as in the original racetrack inflation model. Hence extra fields do not appear to alter the predictions of the model. An equivalent, simplified model with just a single field is presented.

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The utility of the bivalve sentinel organism approach to monitoring for some chemicals of environmental concern in coastal and estuarine areas has been evaluated by regional and national programs and by smaller scale research efforts during the past 15 years. The extent and severity of coastal contamination by chemicals such as polychlorinated biphenyls, chlorinated pesticides, trace metals, and plutonium has been assessed in several bivalve sentinel organism programs. Advantages and limitations of this approach are presented and discussed briefly within the context of both national and international efforts.