Effectiveness of the global protected area network in representing species diversity

The Fifth World Parks Congress in Durban, South Africa, announced in September 2003 that the global network of protected areas now covers 11.5% of the planet's land surface. This surpasses the 10% target proposed a decade earlier, at the Caracas Congress, for 9 out of 14 major terrestrial biomes. Such uniform targets based on percentage of area have become deeply embedded into national and international conservation planning. Although politically expedient, the scientific basis and conservation value of these targets have been questioned. In practice, however, little is known of how to set appropriate targets, or of the extent to which the current global protected area network fulfils its goal of protecting biodiversity. Here, we combine five global data sets on the distribution of species and protected areas to provide the first global gap analysis assessing the effectiveness of protected areas in representing species diversity. We show that the global network is far from complete, and demonstrate the inadequacy of uniform--that is, 'one size fits all'--conservation targets.     

Production of immune interferon by murine T-cell clones from long-term cultures

Production of leukocyte interferon (IFN-alpha) and fibroblast interferon (IFN-beta) can be induced by a variety of agents but immune interferon, IFN-gamma, is only obtained when lymphoid cells are stimulated by specific antigens, allo-antigens or T-cell mitogens. Moreover, in bulk cultures, only small quantities of IFN-gamma are produced. The type of cell producing IFN-gamma has not been unambiguously defined and so we set out to determine whether a pure T-cell population could produce it, exploiting the knowledge that T cells can be maintained indefinitely in tissue culture by the addition of T-cell growth factors. Although not all T cells can found long-term cultures of this kind, cultures of antigen-specific helper, suppressor and killer T cells have been obtained in this way. We now describe the production of substantial amounts of INF-gamma when some (but not all) murine T-cell clones derived from such cultures are stimulated by either concanavalin A (Con A) or phytohaemagglutinin (PHA).