Cooperative Research Centre

About: Cooperative Research Centre is a based out in . It is known for research contribution in the topics: Population & Sea ice. The organization has 7633 authors who have published 8607 publications receiving 429721 citations.

A Scaling Rule for Landscape Patches and How It Applies to Conserving Soil Resources in Savannas

Abstract: Scaling issues are complex, yet understanding issues such as scale dependencies in ecological patterns and processes is usually critical if we are to make sense of ecological data and if we want to predict how land management options, for example, are constrained by scale. In this article, we develop the beginnings of a way to approach the complexity of scaling issues. Our approach is rooted in scaling functions, which integrate the scale dependency of patterns and processes in landscapes with the ways that organisms scale their responses to these patterns and processes. We propose that such functions may have sufficient generality that we can develop scaling rules—statements that link scale with consequences for certain phenomena in certain systems. As an example, we propose that in savanna ecosystems, there is a consistent relationship between the size of vegetation patches in the landscape and the degree to which critical resources, such as soil nutrients or water, become concentrated in these patches. In this case, the features of the scaling functions that underlie this rule have to do with physical processes, such as surface water flow and material redistribution, and the ways that patches of plants physically “capture” such runoff and convert it into plant biomass, thereby concentrating resources and increasing patch size. To be operationally useful, such scaling rules must be expressed in ways that can generate predictions. We developed a scaling equation that can be used to evaluate the potential impacts of different disturbances on vegetation patches and on how soils and their nutrients are conserved within Australian savanna landscapes. We illustrate that for a 10-km2 paddock, given an equivalent area of impact, the thinning of large tree islands potentially can cause a far greater loss of soil nitrogen (21 metric tons) than grazing out small grass clumps (2 metric tons). Although our example is hypothetical, we believe that addressing scaling problems by first conceptualizing scaling functions, then proposing scaling rules, and then deriving scaling equations is a useful approach. Scaling equations can be used in simulation models, or (as we have done) in simple hypothetical scenarios, to collapse the complexity of scaling issues into a manageable framework.

State of the Climate in 2013

Abstract: Editors note: For easy download the posted pdf of the State of the Climate for 2013 is a very low-resolution file. A high-resolution copy of the report is available by clicking here. Please be patient as it may take a few minutes for the high-resolution file to download.

Choosing the future of Antarctica

Abstract: We present two narratives on the future of Antarctica and the Southern Ocean, from the perspective of an observer looking back from 2070. In the first scenario, greenhouse gas emissions remained unchecked, the climate continued to warm, and the policy response was ineffective; this had large ramifications in Antarctica and the Southern Ocean, with worldwide impacts. In the second scenario, ambitious action was taken to limit greenhouse gas emissions and to establish policies that reduced anthropogenic pressure on the environment, slowing the rate of change in Antarctica. Choices made in the next decade will determine what trajectory is realized.

Milk growth factors enriched from cheese whey ameliorate intestinal damage by methotrexate when administered orally to rats

Abstract: Currently, there are no truly effective therapies for the treatment of chemotherapy-induced intestinal mucositis, a debilitating side effect with a pathophysiology common to many chemotherapy regimens. We tested the efficacy of a growth factor extract derived from cheese whey against experimental intestinal mucositis in rats. Rats were subcutaneously injected with the chemotherapeutic drug methotrexate on d 1, 2 and 3 to induce severe damage in the small bowel and bacterial translocation across the gut. Whey extract (15 to 514 mg/d) was given orally for 5-12 d, starting on d 1. Controls were fed an isonitrogenous diet. Histological indices of villus and crypt integrity were utilized to assess potential efficacy of the extract. Administration of the whey extract for 5 d increased the villus surface length indices in the jejunum and ileum by 52% and 56%, respectively (P< 0.001) compared with controls not receiving the whey extract. The crypt area index was 64% greater (P < 0.001) in the jejunum, but not significantly greater in the duodenum or ileum compared with controls not receiving whey extract. Similarly, sucrase activity was significantly higher in the ileum (P < 0.001) but not significantly elevated in the jejunum, whereas bacterial translocation (incidence and number of colonies) was significantly reduced compared with controls not receiving whey extract. We conclude that oral whey growth factor extract reduces methotrexate-induced damage in the small bowel, which suggests clinical applications for the treatment of intestinal mucositis.