Search

Three experiments investigated the relationship between memory for input and inductive learning of morphological rules relating to functional categories in a semiartificial form of Italian. A verbatim memory task was used as both the vehicle for presenting sentences and as a continuous measure of memory performance. Experiments 2 and 3 introduced increasingly explicit manipulations of attention to form compared to Experiment 1. In all experiments there were strong relationships between individual differences in memory for input as measured early in the experiment and eventual learning outcomes, and in Experiments 2 and 3 learning form-form (but not form-function) rules was related to vocabulary learning efficiency (taken as a measure of phonological long-term memory ability). These relationships along with the lack of an effect of feedback in Experiment 3 suggest that subjects tended to adopt a data-driven, as opposed to conceptually driven, mode of learning. However, the fact that the introduction of highlighting and vocabulary pretraining in Experiment 2 had a large impact on learning without improving early memory is taken to suggest that knowledge of distributional rules does not simply emerge out of memory encodings of the relevant forms but depends upon the appropriate allocation of attention over relationships between input elements at the time of encoding.

Erythrocytes offer the exciting opportunity of being used as carriers of therapeutic agents. Encapsulation within erythrocytes will give the therapeutic agent a clearance equivalent to the normal life of the erythrocyte therefore maintaining therapeutic blood levels over prolonged periods and also giving a sustained delivery to the monocyte–macrophage system (reticulo-endothelial system). Both the dose and frequency of therapeutic interventions could thus be reduced. Ensuring a near-physiological survival time of carrier erythrocytes is essential to their successful use as a sustained drug delivery system, and this has not been demonstrated in man. In this study we assessed the survival in vivo of autologous unloaded energy-replete carrier erythrocytes in nine volunteers, using a standard 51Cr erythrocyte-labelling technique. Within 144 h after infusion there was a 3 to 49% fall in circulating labelled cells, followed thereafter by an almost complete return to initial circulating levels; surface counting demonstrated an initial sequestration of erythrocytes by the spleen and subsequent release. Mean cell life and cell half-life of the carrier erythrocytes were within the normal range of 89 to 131 days and 19 to 29 days respectively. These results demonstrate the viability of carrier erythrocytes as a sustained drug delivery system.