Michael P. Johnson

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A variety of marine mammal species have been shown to conserve energy by using negative buoyancy to power prolonged descent glides during dives. A new non-invasive tag attached to North Atlantic right whales recorded swim stroke from changes in pitch angle derived from a three-axis accelerometer. These results show that right whales are positively buoyant(More)
Regression analyses to determine plant species number are repeated for the Galápagos Islands with new data. The multiple curvilinear regression gives the best prediction of species number, with island area making the only significant contribution. The proportion of species endemic to the Galápagos is highest in the arid, transition zone and on small(More)
The generalization error of a function approximator, feature set or smoother can be estimated directly by the leave-one-out cross-validation error. For memory-based methods, this is computationally feasible. We describe an initial version of a general memory-based learning system (GMBL): a large collection of learners brought into a widely applicable(More)
Little is known about the population structure and dynamics of plankton of intertidal rock pools. A numerical model was developed for rock pool plankton with growth limited by both tidal washout and the stress associated with adverse conditions in high-shore pools. This model predicts that a stress tolerant species will tend to have maximum population(More)
In four experiments, we examined the effect that presenting a verbal stimulus (viz., an English noun) alongside an abstract visual stimulus (viz., a Chinese character) enhances recognition memory for the abstract visual stimulus. Experiment 1 demonstrated that the character-plus-word combination at both encoding and retrieval results in better recognition(More)
The available data for two important Irish estuaries, Cork and Wexford harbours, were analysed to identify ‘hot spots’: locations where water quality variables are likely to differ from background levels. The approach taken reflects the limitations imposed by restricted spatial and temporal replication in the available datasets. Information for many(More)
Habitats may have dynamics that exist independently of the population densities of species occupying the habitat. For example, ephemeral habitat patches may disappear regardless of whether a particular species is present or not. Such habitat dynamics are frequently modelled by ignoring age-related variation in patch turnover rates. This can be thought of as(More)