Smart allocation of restoration funds over space and time.

A challenge for natural area managers is to ensure that public expenditure on land restoration is cost effective, efficient and transparent but this is difficult to achieve in practice, especially when there are many possible projects across multiple years. Here we develop a "roadmap" for investment in land restoration. It explicitly considers space, time and their interaction, in relation to ecological outcomes and restoration costs (and their variation in time and space). Using integer linear programming optimization in a benefit-cost accounting framework, the roadmap incorporates: transitions between different stages of ecological recovery in a spatial mosaic of multiple ecosystem types; cost schedules associated with managing those transitions over time; time lags between beginning management and achieving outcomes; variations to constraints and goals associated with various factors including site accessibility, specific conservation priorities (such as threatened species or ecosystems); and background environmental trends. This approach enables land managers to: (1) forecast landscape-scale outcomes of management strategies over long timeframes; (2) address the question of how long it will take and how much it will cost to achieve specific outcomes; and (3) explore potential trade-offs in outcomes among alternative management strategies. We illustrate its application using a case study of forest restoration in Australia by a local government authority across a public conservation estate comprising 765 land units of varying size, totaling ˜13,000 ha, across five different floristic vegetation types, with an annual budget of ˜AU$5M, projected over a 50-yr timeframe. These simulations revealed a trade-off between management strategies that seek to increase either the total cover of native forest or the amount of high quality forest: quality-based strategies were favored in scenarios in which shorter term (20-30 yr) timeframes were chosen at the outset, but cover-based strategies were favored if longer time horizons were initially targeted. Projected outcomes were also strongly influenced by assumed background rates of vegetation decline or recovery. Many of the issues in this restoration roadmap are generalizable (even though specific outcomes and trade-offs are likely to vary among case studies), and the approach is both scalable and transferable to other regions and ecosystems.

Changes in expression of P2X7 receptors in NOD mouse pancreas during the development of diabetes.

This study examined the expression of P2X7 receptors in pancreatic islets of the non-obese diabetic (NOD) mouse model of human autoimmune insulin-dependent diabetes mellitus, to determine whether they are involved in islet cell destruction during early- and late-developing diabetes. Pancreatic cells containing glucagon (alpha-cells), insulin (beta-cells) and somatostatin (delta-cells) were co-localized with P2X7 receptors. We examined P2X7 receptor expression in normal and diabetic spleens using flow cytometry. In non-diabetic NOD controls, P2X7 receptors were expressed in glucagon-containing cells at the periphery of islets, being consistent with previous studies. In early NOD diabetes (12 weeks), there was migration of peripheral P2X7 receptor positive, glucagon-containing cells into the center of islets. In late NOD diabetes (34 weeks), P2X7 receptor- and glucagon-stained alpha-cells were gone from islets. Migration of macrophages and dendritic cells into islets took place, but they lacked P2X7 immunoreactivity. There was no significant difference in the percentage of splenic macrophages stained for P2X7 receptors from control and diabetic spleens. In conclusion, in the development of early to late diabetes, there is a down-regulation of P2X7 receptors on islet cells and a loss of alpha- and beta-cell populations. P2X7 receptor signalling might be involved in alpha-cell clearance from late diabetic islets.

Animal visual systems and the evolution of color patterns: sensory processing illuminates signal evolution.

Animal color pattern phenotypes evolve rapidly. What influences their evolution? Because color patterns are used in communication, selection for signal efficacy, relative to the intended receiver's visual system, may explain and predict the direction of evolution. We investigated this in bowerbirds, whose color patterns consist of plumage, bower structure, and ornaments and whose visual displays are presented under predictable visual conditions. We used data on avian vision, environmental conditions, color pattern properties, and an estimate of the bowerbird phylogeny to test hypotheses about evolutionary effects of visual processing. Different components of the color pattern evolve differently. Plumage sexual dimorphism increased and then decreased, while overall (plumage plus bower) visual contrast increased. The use of bowers allows relative crypsis of the bird but increased efficacy of the signal as a whole. Ornaments do not elaborate existing plumage features but instead are innovations (new color schemes) that increase signal efficacy. Isolation between species could be facilitated by plumage but not ornaments, because we observed character displacement only in plumage. Bowerbird color pattern evolution is at least partially predictable from the function of the visual system and from knowledge of different functions of different components of the color patterns. This provides clues to how more constrained visual signaling systems may evolve.

P2X and P2Y purinoceptor expression in pancreas from streptozotocin-diabetic rats.

The expression of the nucleotide receptors P2X1, P2X2, P2X7, P2Y1, P2Y2 and P2Y4, in the pancreas of the streptozotocin-induced diabetic rat was investigated using immunohistochemistry. In diabetic animals, P2X7 receptor expression, normally located in the outer periphery of the islet, was increased and located inside the islet. Double-labelling experiments, using antibodies raised against insulin, somatostatin and glucagon, showed, for the first time, an increase in immunostaining for P2X7 receptors on islet glucagon-containing alpha cells (which had migrated to the interior), while no P2X7 receptors were found in beta and delta cells. P2Y1 receptors were present in intra-islet capillaries, while P2Y4 receptors were found on both alpha and beta cells. P2Y1 and P2Y2 receptor expression was also found in pancreatic duct cells and P2X1, P2X2, P2Y1 and P2Y2 receptors were identified in small blood vessels.