JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. This content downloaded from 160.36.178.25 on Wed, 07 Oct 2015 20:42:12 UTC All use subject to JSTOR Terms and ConditionsAbstract. We present two models of growth and reproduction in the mussel Mytilus edulis L. One is a modified version of an existing model developed by Kooijman for general application to ectotherms, the other is a new model specifically formulated for mussels. The models have identical assumptions on energy assimilation and spawning but differ in their a priori assumptions concerning energy partitioning between growth, maintenance and reproduction. Data from three field populations were used: one to estimate model parameters; the others for model testing. Both models were successful in predicting growth and reproduction in the test populations, suggesting that differences between populations can largely be explained by differences in food and seston dynamics. The models yield two contrasting strategies for storing and utilizing assimilate, and with further assumptions yield hypotheses on mortality in fast and slow growing populations.

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Health technologies, especially medical and assistive health technology, are essential to ensure older people's dignity and autonomy, but their current and potential benefits have received little recognition in LMICs. Viewing these technologies as relevant only to disabled people is an inadequate approach. They should be accessible to both older adults with disabilities and older adults with functional limitation. Many countries need much greater official awareness of older adults' needs and preferences. Such attitudinal changes should then be reflected in laws and regulations to address the specificities of care for older people.

Reproductive cycles of the Pacific oysterCrassostrea gigas (Thunberg) from the Marlborough Sounds, New Zealand, were followed between June 1998 and January 2000. Histological examination of the gonad confirms an annual cycle with a winter inactive period followed by rapid gonad development and a single short spawning period. The population gonad index correlated with seawater temperature and changes in tissue dry weight, condition index, and biochemical components. In winter, few individuals with early gametogenic stages were present and rapid development of primary oocytes (diam. 11 µm) occurred during spring (September-November). The developmental rate and the diameter of mature oocytes (37 µm) was similar for the 1998 and 1999 seasons. For a standard 110-mm-length oyster, maximal tissue body weight and condition index were recorded in December. Rapid weight loss in January was length dependent and was attributed to spawning. environmental variable which best correlated with the timing of gametogenesis. Food availability (phytoplankton biomass) may have been responsible for inter-annual variations. The biochemical composition (% glycogen, lipid, protein) of separated gonad and somatic tissues were variable seasonally and annually. Gametogenesis (oocyte diameter) was associated with increased gonad protein and glycogen and a decrease in lipid concentrations. These changes are similar to those in Pacific oyster populations from other parts of the world.

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