Navigation mit Duftkarte und Sonnenkompaß: Das Heimfindevermögen der Brieftauben

Pigeon homing, investigated as a paradigmatic example of bird navigation, appears to be based on two mechanisms of orientation whose functions correspond to those of map and compass. Tasks of the latter are usually accomplished by a sun compass, taking into account the sun's movement and time of day. Under overcast skies, the magnetic field of the earth may be used for compass orientation. The "map" part of the system, responsible for site localization, makes use of olfactory perception of atmospheric trace compounds, which must be concluded to contain positional information in unfamiliar areas up to several hundreds of kilometers from home.     

Managing environmental quality at the enterprise: the role of project management

An exploratory field study conducted in Europe and the U.S. examines the challenges of managing environmental quality at the enterprise level. The results show that effective environmental quality management depend to a considerable degree on the ability to deal with the multidisciplinary organizational, technical, social, and cultural issues involved in the integration of environmental cost accounting at the enterprise level. The study suggests that the tools and techniques of modern project management can provide an important framework for developing and implementing environmental quality control systems. The recommendations put considerable emphasis on the human side, focusing on the criteria under which environmental quality is best achievable. Strong senior management leadership, people skills, organizational linkages, and alliances, all are critical for dealing with the complexities of managing responsibly toward sustained developments in today’s organizations.     

Biochemistry of lignification

The complete set of enzymes that catalyze the reactions from l-phenylalanine to substituted cinnamyl alcohols is now known. The latter compounds are the primary building stones of lignin. The individual reactions and the possible modes of regulation of this pathway are discussed. The polymerization of cinnamyl alcohols to lignin is mediated by peroxidase. The significance of cell-wall-bound peroxidases in this process and the origin of hydrogen peroxide are reviewed. Finally, the possible role of lignification in relation to disease resistance is discussed.