Larval habitat for three highland Anopheles species: Anopheles albimanus Wiedemann, Anopheles pseudopunctipennis Theobald, and Anopheles punctimacula Dyar and Knab was related to human land uses, rivers, roads, and remotely sensed land cover classifications in the western Ecuadorian Andes. Of the five commonly observed human land uses, cattle pasture (n = 30) provided potentially suitable habit...

Global declines in pollinators, associated with land-use change [1-6] and fragmentation [7-10], constitute a serious threat to crop production and biodiversity [11]. Models investigating impacts of habitat fragmentation on pollen flow have categorized landscapes simply in terms of habitat and nonhabitat. We show that pollen flow depends strongly on types of land use between habitat fragments. W...

The study of habitat use and selection in birds has a long tradition (Grinnell 1917, Kendeigh 1945, Svardson 1949, Hild6n 1965; Block and Brennan 1993). Early habitat-selection theory was characterized by correlative models of habitat characteristics and species abundance (MacArthur and Pianka 1966, Verner et al. 1986, Rosenzweig 1991), which subsequently evolved into models that involved densi...

There is ample evidence that the use of safety behaviour can interfere with the progress of therapy, particularly if exposure is involved. As a result, it is widely asserted that safety behaviour is anti-therapeutic. However, an unqualified rejection of safety behaviour should be reconsidered because we now have theoretical justification, experimental evidence and clinical observations showing ...

Since the development of monoclonal antibodies twenty-five years ago, researchers and biotech companies have been looking to develop therapeutic uses for them. Michael Gross looks at some of the latest efforts.

Introduction Application of a Hierarchical Habitat Unit Classification System: Stream Habitat and Salmonid Distribution in Ward Creek, Southeast Alaska M.D. Bryant, B.E. Wright, and B.J. Davies A hierarchical classification system separating stream habitat into habitat units defined by stream morphology and hydrology was used in a pre-enhancement stream survey. The system separates habitat unit...