How predatory mites learn to cope with variability in volatile plant signals in the environment of their herbivorous prey.

When the chemical cues co-occurring with prey vary in time and space, foraging predators profit from an ability to repeatedly associate chemical cues with the presence of their prey. We demonstrate the ability of a predatory arthropod (the plant-inhabiting mite, Phytoseiulus persimilis) to learn the association of a positive stimulus (herbivorous prey, Tetranychus urticae) or a negative stimulus (hunger) with a chemical cue (herbivore-induced plant volatiles or green leaf volatiles). It has been suggested that the rate at which the integration of information becomes manifest as a change in behaviour, differs between categories of natural enemies (parasitoids versus insect predators: specialist versus generalist predators).

Envelopes: presidential address.

The fabric of medical care has been altered during the past 2 decades. Initially this alteration was furtive but it rapidly escalated, producing change that will be irrevocable. Physicians, dedicated to caring for their patients, frequently were found struggling in the wake of the changes in the health care system.

Breast disease: a primer on diagnosis and management.

Currently, mammography is the only method of detecting nonpalpable, early breast cancer. At this stage, 90% of the cancers are curable. Clearly, this fundamental tenet accentuates the importance of compliance and knowledge of guidelines.

Breast cysts and solid lesions: the role of fine-needle aspiration.

Breast cyst aspiration and fine-needle or needle-core biopsy of palpable and nonpalpable breast masses can be cost-effective and in some situations provide instant resolution of cystic masses. The limitations of the techniques must be known if the benefits are to be exploited. New evaluations on cyst fluid demonstrating proteins (common to breast cancer) have been demonstrated, as well as assessment of electrolyte ratios in fluid.