UDP-Gal: <Emphasis Type="Italic">N</Emphasis>-acetylglucosamine β 1–4 galactosyltransferase expressing live attenuated parasites as vaccine for visceral leishmaniasis

As compared to cutaneous leishmaniasis, vaccination against visceral leishmaniasis (VL) has received limited attention. In this study, we demonstrate for the first time that an UDP-Galactose: N-acetylglucosamine β 1–4 galactosyltransferase (GenBank Accession No. EF159943) expressing attenuated LD clonal population (A-LD) is able to confer protection against the experimental challenge with the virulent LD AG83 parasite. A-LD was also effective in established leishmania infection. The vaccinated animals showed both cell mediated (in vitro T-cell proliferation, and DTH response) and humoral responses (Th1 type). These results demonstrate the potential of the attenuated clones as an immunotherapeutic and immunoprophylactic agent against visceral leishmaniasis.     

Linkages between seagrass,mangrove and saltmarsh as fish habitat in the Botany Bay estuary,New South Wales

Shallow-water vegetated estuarine habitats, notably seagrass, mangrove and saltmarsh, are known to be important habitats for many species of small or juvenile fish in temperate Australia. However, the movement of fish between these habitats is poorly understood, and yet critical to the management of the estuarine fisheries resource. We installed a series of buoyant pop nets in adjacent stands of seagrass, mangrove and saltmarsh in order to determine how relative abundance of fishes varied through lunar cycles. Nets were released in all habitats at the peak of the monthly spring tide for 12 months, and in the seagrass habitat at the peak of the neap tide also. The assemblage of fish in each habitat differed during the spring tides. The seagrass assemblage differed between spring and neap tide, with the neap tide assemblage showing greater abundances of fish, particularly those species which visited the adjacent habitats when inundated during spring tides. The result supports the hypothesis that fish move from the seagrass to the adjacent mangrove and saltmarsh during spring tides, taking advantage of high abundances of zooplankton, and use seagrass as a refuge during lower tides. The restoration and preservation of mangrove and saltmarsh utility as fish habitat may in some situations be linked to the proximity of available seagrass.     

Economic incentives for conservation: beekeeping and Saturniidae caterpillar utilization by rural communities

The economic viability of the wildlife based enterprises (bee-keeping and caterpillar utilization) in Malawi is discussed in relation to conventional agricultural enterprises (maize, beans and ground-nuts). A strong incentive emerges for rural people to adopt wildlife management as an adjunct to subsistence agriculture, and therefore, to promote conservation of natural ecosystems and wildlife habitats in the face of growing human population and demand for land. Dependence on agriculture has depleted the wildlife resource outside protected areas and has been less effective in improving the wealth and living standards of most rural people. This study illustrates that the Malawi Department of National Parks and Wildlife needs to introduce economic incentives that integrate biological conservation with economic development for the rural people. The management programme involves the adoption of a rotation burning policy that promotes vegetation coppicing, eases harvesting and promotes high caterpillar yields.     

A proposed neural pathway for vocalization in South African clawed frogs,Xenopus laevis

Vocalizations of South African clawed frogs are produced by contractions of laryngeal muscles innervated by motor neurons of the caudal medulla (within cranial nerve nucleus IX-X). We have traced afferents to laryngeal motor neurons in male and female frogs using retrograde axonal transport of horseradish peroxidase conjugated to wheat germ agglutinin (HRP-WGA). After iontophoretic injection of HRP-WGA into n. IX-X, retrogradely labelled neurons were seen in the contralateral n. IX-X, in rhombencephalic reticular nuclei, and in the pre-trigeminal nucleus of the dorsal tegmental area (DTAM) of both males and females.