The Role of Barrier Islands in Subsistence of the Inhabitants of Roviana Lagoon,Solomon Islands

This multidisciplinary study examines the strategy adopted by villagers in the Roviana Lagoon, South New Georgia, Solomon Islands, to cope with changing socioeconomic and demographic conditions. The study addresses land use, shifting cycles, land tenure, soil nutrients, subsistence production, vegetation, land cover change, and carrying capacity. The results suggested that even if a society had been integrated into the market economy and introduced cash cropping, they used a small island, which was fertile, mainly for traditional shifting cultivation under customary management. However, they used a large area of the main island for cultivation of potentially risky perennial cash crops for private income. This case suggests that a local society is able to develop a harmonized way of rural development, community welfare, and environmental preservation.     

Fractone‐heparan sulphates mediate FGF‐2 stimulation of cell proliferation in the adult subventricular zone

Objectives: Fractones are extracellular matrix structures that form a niche for neural stem cells and their immediate progeny in the subventricular zone of the lateral ventricle (SVZa), the primary neurogenic zone in the adult brain. We have previously shown that heparan sulphates (HS) associated with fractones bind fibroblast growth factor‐2 (FGF‐2), a powerful mitotic growth factor in the SVZa. Here, our objective was to determine whether the binding of FGF‐2 to fractone‐HS is implicated in the mechanism leading to cell proliferation in the SVZa. Materials and methods: Heparitinase‐1 was intracerebroventricularly injected with FGF‐2 to N‐desulfate HS proteoglycans and determine whether the loss of HS and of FGF‐2 binding to fractones modifies FGF‐2 effect on cell proliferation. We also examined in vivo the binding of Alexa‐Fluor‐FGF‐2 in relationship with the location of HS immunoreactivity in the SVZa. Results: Heparatinase‐1 drastically reduced the stimulatory effect of FGF‐2 on cell proliferation in the SVZa. Alexa‐Fluor‐FGF‐2 binding was strictly co‐localized with HS immunoreactivity in fractones and adjacent vascular basement membranes in the SVZa. Conclusions: Our results demonstrate that FGF‐2 requires HS to stimulate cell proliferation in the SVZa and suggest that HS associated with fractones and vascular basement membranes are responsible for activating FGF‐2. Therefore, fractones and vascular basement membranes may function as a HS niche to drive cell proliferation in the adult neurogenic zone.