A Method for Catchment Scale Mapping of Groundwater-Dependent Ecosystems to Support Natural Resource Management (Queensland, Australia).

Immediate and foreseeable threats to groundwater-dependent ecosystems (GDEs) are widely acknowledged, many linked to altered groundwater regimes including changes in groundwater flow, flux, pressure, level and/or quality (Eamus et al. in Aust J Bot 54:97-114, 2006a). Natural resource managers and other decision-makers often lack sufficient information at an appropriate scale to understand the groundwater dependency of ecosystems and ensure that GDEs are adequately considered in decision-making processes. This paper describes a new catchment scale mapping method for GDEs based on the integration of local expert knowledge with detailed spatial datasets to delineate GDEs at a scale compatible with management and planning activities. This overcomes one of the key criticisms often levelled at broader scale mapping methods-that information from local and regional experts, with significant understanding of landscape processes and ecosystems, is not incorporated into the datasets used by decision-makers. Expert knowledge is conveyed in the form of pictorial conceptual models representing the components, processes and interrelationships of groundwater within a catchment and the ecosystems dependent on it. Each mapped GDE is linked to a pictorial conceptual model and a mapping rule-set to provide decision-makers with valuable information about where, how and why GDEs exist in a landscape.

Antimalarial activity of Ajuga remota Benth (Labiatae) and Caesalpinia volkensii Harms (Caesalpiniaceae): in vitro confirmation of ethnopharmacological use.

Field trips to herbalists' practices in an area about 200 miles around Nairobi (Kenya) enabled us to make a list of medicinal plant species preferentially used to treat malaria. Ajuga remota and Caesalpinia volkensii were further investigated as being the most frequently used species. Aqueous decoctions, ethanol macerates, and petroleum ether, methanol and water Soxhlet extracts of these plants were further tested for their in vitro antimalarial properties in a chloroquine sensitive (FCA/20GHA) and resistant (W2) strain of Plasmodium falciparum. The activity was assessed by the parasite lactate dehydrogenase (pLDH) assay method. There was a concentration-dependent inhibition by the vegetal extracts of both plants. The IC(50) of the most active A. remota extract (ethanol macerate) was 55 and 57 microg/ml against FCA/20GHA and W2, respectively. For C. volkensii, it was the Soxhlet-water extract which was most active against FCA/20GHA with an IC(50) of 404 microg/ml while the petroleum ether extract exhibited the most activity against W2 with an IC(50) of 250 microg/ml. Further phytochemical work is being done in order to identify the active principles.

Effects of the active constituents of Catha edulis on the neuromuscular junction.

(-)-Cathinone and d-norpseudoephedrine (DNE) in the dose range 0.2-1.2 mg/ml produced a reduction in contractions of skeletal muscle, evoked by direct and indirect electrical stimulation and antagonised the facilitatory action of physostigmine on the neuromuscular junction; but failed to antagonise a partial blockade induced by d-tubocurarine (dTb) as occurs with norepinephrine or epinephrine. The local anaesthetic actions of (-)-cathinone and DNE were found to be almost equivalent to that of lignocaine. These results indicate that (-)-cathinone and DNE may have a direct blocking action on the neuromuscular junction, which is independent of cholinergic and adrenergic transmission.