Macroparasite dynamics of migratory host populations.

Spatial variability in host density is a key factor affecting disease dynamics of wildlife, and yet there are few spatially explicit models of host-macroparasite dynamics. This limits our understanding of parasitism in migratory hosts, whose densities change considerably in both space and time. In this paper, we develop a model for host-macroparasite dynamics that considers the directional movement of host populations and their associated parasites.

How to be a good neighbour: Facilitation and competition between two co-flowering species.

Empirical evidence suggests that co-flowering species can facilitate each other through shared pollinators. However, the extent to which one co-flowering species can relieve pollination limitation of another while simultaneously competing for abiotic resource has rarely been examined. Using a deterministic model we explored the demographic outcome for one ("focal") species of its co-occurrence with a species that shares pollinators and competes for both pollinator visitation and abiotic resources.

Climate Change and Integrodifference Equations in a Stochastic Environment.

Climate change impacts population distributions, forcing some species to migrate poleward if they are to survive and keep up with the suitable habitat that is shifting with the temperature isoclines. Previous studies have analysed whether populations have the capacity to keep up with shifting temperature isoclines, and have mathematically determined the combination of growth and dispersal that is needed to achieve this. However, the rate of isocline movement can be highly variable, with much uncertainty associated with yearly shifts.

Metabolic control of resistance of human epithelial cells to H2O2 and NO stresses.

The carbon flux through the oxidative branch of the pentose phosphate pathway (PPP) can be viewed as an integrator of the antioxidant mechanisms via the generation of NADPH. It could therefore be used as a control point of the cellular response to an oxidative stress. Replacement of glucose by galactose sensitized the human epithelial cell line HGT-1 to H2O2 stress.

Effect of plasma fractions from patients with focal and segmental glomerulosclerosis on rat proteinuria.

Background: Patients suffering from focal and segmental glomerulosclerosis (FSGS) and in whom this disease recurs after transplantation are likely to have an active form of the disease and to have a factor(s) (such as, albuminuric factor) present in their blood that alters glomerular permeability for albumin.

Methods: We used a sequential 50 and 70% ammonium sulfate (AS) precipitation of plasma from patients with relapsing FSGS and non-FSGS nephrotic syndrome (NS), in addition to plasma from healthy individuals, to obtain both an immunoglobulin (Ig)-rich fraction (50% AS precipitate) and a non-Ig fraction (70% AS supernatant). These fractions were injected intra-arterially or intravenously/intraperitoneally into Sprague-Dawley rats, and proteinuria (g protein/mmol creatinine) was measured for 24 hours.