SUMMARYIntracerebral inoculation was more effective than intraperitoneal, intravenous or subcutaneous inoculation as a means of producing lethal infections withFusobacterium necrophorumin mice. Strains varied in virulence but, of five examined, two had LD50 values as low asca. 8000 and 14000 viable organisms. Profuse bacterial multiplication in the brain was demonstrated. Intravenous vaccination with a single large dose of heat-killed whole culture or washed bacterial cells failed to protect against intracerebral challenge.Intracerebral injection of other fusobacteria (F. nucleatum, F. variumandF. necrogenes) and of 22 strains belonging to 10Bacteroidesspp. was without apparent effect on mice, except for a slight transient illness in some animals givenB. fragilis. This organism (five strains) differed from the otherBacteroidesspp. tested, which included eight strains belonging to the fragilis group, in being eliminated more slowly from the mouse brain – a point that may be relevant to the special pathogenicity ofB. fragilisin endogenous infections in man. There was no evidence thatB. fragilismultiplied in the brain or that intravenous vaccination with a large dose of heat-killed homologous culture affected the rate at which it was eliminated.
Adaptive management of social-ecological systems requires integration and collaboration among scientists, policy makers, practitioners, and stakeholders across multiple disciplines and organizations. Challenges associated with such integration have been attributed to gaps between how human systems are organized and how ecosystems function. To address this gap, we explore the application of information ecology as a theoretical basis for integrating human systems and natural systems. First, we provide an overview of information ecology with reference to its relationship with information theory and how we define "information." Principles governing whole-part relationships, i.e., holons and holarchies, are then used to develop a general information flow model for evolutionary, complex adaptive systems. This general model is then applied to examine a number of issues related to science-policy integration and in the development of a reference framework for practical application in adaptive management. A number of additional considerations for practical use of the framework are also discussed.
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