An assay technique, homogeneous enzyme immunoassay, is described for the quantitative determination of morphine derivatives in biological fluids. An enzyme is labeled with morphine. When the enzymelabeled morphine is bound by antimorphine antibodies, the enzyme is rendered inactive. Free morphine competes with enzyme-morphine for antibody binding sites preventing inhibition of enzyme activity. ...

Molecular techniques have had a profound impact in biology. Major disciplines, including evolutionary biology, now consistently utilize molecular tools. In contrast, molecular techniques have had a more limited impact in ecology. This discrepancy is surprising. Here, we describe the unexpected paucity of ecological research in the field colloquially referred to as ‘molecular ecology.’ Publicati...

He received his B.Sc. degree in Biology (1990) from Department of Biology, University of British Columbia, Canada, also M.Sc. in Botany (1993) from Department of Botany, University of British Columbia, Canada and Ph.D. in Plant Ecology (1996) from Department of Animal & Plant Sciences, University of Sheffield, England.Dr. Fraser's expertise is in grassland and wetland ecosystems, with a focus o...

Theoretical ecology uses conceptual and mathematical models, computer simulations, and data analysis to study ecological systems. Alan Hastings, a Distinguished Professor of Environmental Science and Policy at the University of California, Davis, has contributed significantly to the development of this field over the past four decades. Much of his research uses mathematical models of population...

We discuss the concept of Enaction as originally proposed by Varela. We attempt to exemplify through two specific topics, sensory ecology and behavior, as well as physiological and behavioral ecology, on which the enactive approach is based. We argue that sensory physiology allows us to explore the biological and cognitive meaning of animal 'private' sensory channels, beyond the scope of our ow...

Because of the contingency and complexity of its subject matter, community ecology has few general laws. Laws and models in community ecology are highly contingent, and their domain is usually very local. This fact does not mean that community ecology is a weak science; in fact, it is the locus of exciting advances, with growing mechanistic understanding of causes, patterns, and processes. Furt...

Identification of birds not only means identifying the species of an individual, but also can include identifying its subspecies, sex, and age. Field identification of the age and sex of a bird can be important for studying many aspects of avian ecology and evolution, including life history evolution, reproductive ecology, and behavioral ecology. Ornithologists use a variety of characteristics ...

Because of the contingency and complexity of its subject matter, community ecology has few general laws. Laws and models in community ecology are highly contingent, and their domain is usually very local. This fact does not mean that community ecology is a weak science; in fact, it is the locus of exciting advances, with growing mechanistic understanding of causes, patterns, and processes. Furt...