Dynamic social networks in guppies (Poecilia reticulata)

One of the main challenges in the study of social networks in vertebrates is to close the gap between group patterns and dynamics. Usually scan samples or transect data are recorded to provide information about social patterns of animals, but these techniques themselves do not shed much light on the underlying dynamics of such groups. Here we show an approach which captures the fission-fusion dynamics of a fish population in the wild and demonstrates how the gap between pattern and dynamics may be closed. Our analysis revealed that guppies have complex association patterns that are characterised by close strong connections between individuals of similar behavioural type. Intriguingly, the preference for particular social partners is not expressed in the length of associations but in their frequency. Finally, we show that the observed association preferences could have important consequences for transmission processes in animal social networks, thus moving the emphasis of network research from descriptive mechanistic studies to functional and predictive ones. © 2014 Springer-Verlag Berlin Heidelberg

Finding the sweet spot: Can social marketing encourage cane farmers to change practices for water quality outcomes in the Great Barrier Reef Catchment?

The Great Barrier Reef is under increasing pressure from the cumulative effects of climate change, land-based runoff, coastal land-use change and direct use impacts. Many water quality behaviour change programs fail to achieve sustained change using traditional methods. NQ Dry Tropics received funding from the Queensland Government Reef Water Quality Program to trial methods with 14 farmers at two wetland sites, to achieve water quality outcomes in the sugarcane farming sector of the Lower Burdekin. These methods sought to increase the adoption of practice changes to reduce excess irrigation and nutrients in the fun off flowing into nearby wetlands using an adapted community-based social marketing methodology to understand an individual's perceived benefits and barriers to practice change, and create tailored extension, engagement, and communication tools. This paper will evaluate the effectives of using social marketing techniques to change the attitudes and behaviour of the sugarcane farmers

Eosinophils secrete IL-4 to facilitate liver regeneration

The liver is a central organ for the synthesis and storage of nutrients, production of serum proteins and hormones, and breakdown of toxins and metabolites. Because the liver is susceptible to toxin- or pathogen-mediated injury, it maintains a remarkable capacity to regenerate by compensatory growth. Specifically, in response to injury, quiescent hepatocytes enter the cell cycle and undergo DNA replication to promote liver regrowth. Despite the elucidation of a number of regenerative factors, the mechanisms by which liver injury triggers hepatocyte proliferation are incompletely understood. We demonstrate here that eosinophils stimulate liver regeneration after partial hepatectomy and toxin-mediated injury. Liver injury results in rapid recruitment of eosinophils, which secrete IL-4 to promote the proliferation of quiescent hepatocytes. Surprisingly, signaling via the IL-4Rα in macrophages, which have been implicated in tissue repair, is dispensable for hepatocyte proliferation and liver regrowth after injury. Instead, IL-4 exerts its proliferative actions via IL-4Rα in hepatocytes. Our findings thus provide a unique mechanism by which eosinophil-derived IL-4 stimulates hepatocyte proliferation in regenerating liver