The Ecological Physiology of Earth's Second Oxygen Revolution

Living animals display a variety of morphological, physiological, and biochemical characters that enable them to live in low-oxygen environments. These features and the organisms that have evolved them are distributed in a regular pattern across dioxygen (O2) gradients associated with modern oxygen minimum zones. This distribution provides a template for interpreting the stratigraphic covariance between inferred Ediacaran-Cambrian oxygenation and early animal diversification. Although Cambrian oxygen must have reached 10--20% of modern levels, sufficient to support the animal diversity recorded by fossils, it may not have been much higher than this. Today’s levels may have been approached only later in the Paleozoic Era. Nonetheless, Ediacaran-Cambrian oxygenation may have pushed surface environments across the low, but critical, physiological thresholds required for large, active animals, especially carnivores. Continued focus on the quantification of the partial pressure of oxygen (pO2) in the Proterozoic will provide the definitive tests of oxygen-based coevolutionary hypotheses.Earth and Planetary SciencesOrganismic and Evolutionary Biolog

Oxygen, Ecology, and the Cambrian Radiation of Animals

The Proterozoic-Cambrian transition records the appearance of essentially all animal body plans (phyla), yet to date no single hypothesis adequately explains both the timing of the event and the evident increase in diversity and disparity. Ecological triggers focused on escalatory predator–prey “arms races” can explain the evolutionary pattern but not its timing, whereas environmental triggers, particularly ocean/atmosphere oxygenation, do the reverse. Using modern oxygen minimum zones as an analog for Proterozoic oceans, we explore the effect of low oxygen levels on the feeding ecology of polychaetes, the dominant macrofaunal animals in deep-sea sediments. Here we show that low oxygen is clearly linked to low proportions of carnivores in a community and low diversity of carnivorous taxa, whereas higher oxygen levels support more complex food webs. The recognition of a physiological control on carnivory therefore links environmental triggers and ecological drivers, providing an integrated explanation for both the pattern and timing of Cambrian animal radiation.Earth and Planetary SciencesOrganismic and Evolutionary Biolog

Patterns of sulfur isotope fractionation during microbial sulfate reduction

Studies of microbial sulfate reduction have suggested that the magnitude of sulfur isotope fractionation varies with sulfate concentration. Small apparent sulfur isotope fractionations preserved in Archean rocks have been interpreted as suggesting Archean sulfate concentrations of <200 μm, while larger fractionations thereafter have been interpreted to require higher concentrations. In this work, we demonstrate that fractionation imposed by sulfate reduction can be a function of concentration over a millimolar range, but that nature of this relationship depends on the organism studied. Two sulfate-reducing bacteria grown in continuous culture with sulfate concentrations ranging from 0.1 to 6 mm showed markedly different relationships between sulfate concentration and isotope fractionation. Desulfovibrio vulgaris str. Hildenborough showed a large and relatively constant isotope fractionation (34εSO4-H2S ≅ 25‰), while fractionation by Desulfovibrio alaskensis G20 strongly correlated with sulfate concentration over the same range. Both data sets can be modeled as Michaelis–Menten (MM)-type relationships but with very different MM constants, suggesting that the fractionations imposed by these organisms are highly dependent on strain-specific factors. These data reveal complexity in the sulfate concentration–fractionation relationship. Fractionation during MSR relates to sulfate concentration but also to strain-specific physiological parameters such as the affinity for sulfate and electron donors. Previous studies have suggested that the sulfate concentration–fractionation relationship is best described with a MM fit. We present a simple model in which the MM fit with sulfate concentration and hyperbolic fit with growth rate emerge from simple physiological assumptions. As both environmental and biological factors influence the fractionation recorded in geological samples, understanding their relationship is critical to interpreting the sulfur isotope record. As the uptake machinery for both sulfate and electrons has been subject to selective pressure over Earth history, its evolution may complicate efforts to uniquely reconstruct ambient sulfate concentrations from a single sulfur isotopic composition.Earth and Planetary Science

Intravital FRAP imaging using an E-cadherin-GFP mouse reveals disease- and drug-dependent dynamic regulation of cell-cell junctions in live tissue

E-cadherin-mediated cell-cell junctions play a prominent role in maintaining the epithelial architecture. The disruption or deregulation of these adhesions in cancer can lead to the collapse of tumor epithelia that precedes invasion and subsequent metastasis. Here we generated an E-cadherin-GFP mouse that enables intravital photobleaching and quantification of E-cadherin mobility in live tissue without affecting normal biology. We demonstrate the broad applications of this mouse by examining E-cadherin regulation in multiple tissues, including mammary, brain, liver, and kidney tissue, while specifically monitoring E-cadherin mobility during disease progression in the pancreas. We assess E-cadherin stability in native pancreatic tissue upon genetic manipulation involving Kras and p53 or in response to anti-invasive drug treatment and gain insights into the dynamic remodeling of E-cadherin during in situ cancer progression. FRAP in the E-cadherin-GFP mouse, therefore, promises to be a valuable tool to fundamentally expand our understanding of E-cadherin-mediated events in native microenvironments

Security governance and the private military industry in Europe and North America

Even before Iraq the growing use of private military contractors has been widely discussed in the academic and public literature. However, the reasons for this proliferation of private military companies and its implications are frequently generalized due to a lack of suitable theoretical approaches for the analysis of private means of violence in contemporary security. As a consequence, this article contends, the analysis of the growth of the private military industry typically conflates two separate developments: the failure of some developing states to provide for their national security and the privatisation of military services in industrialized nations in Europe and North America. This article focuses on the latter and argues that the concept of security governance can be used as a theoretical framework for understanding the distinct development, problems and solutions for the governance of the private military industry in developed countries.The United States Institute of Peace and the German Academic Exchange Service

Proximity as a Journalistic Keyword in the Digital Era : A study on the “closeness” of amateur news images

Proximity is an ambiguous journalistic notion for which there is no single definition. In this article, we re-evaluate the relevance and use of the concept in the digital news environment. Based on interviews with journalists in Finland and audience focus groups in Finland and the United Kingdom, we ask how new forms of visual amateur production incorporated into professional news journalism have transformed the concept. The concept of proximity has evolved from being a criterion of news selection into a central imperative of news production aiming to engage audiences. Through the prism of amateur news imagery, proximity appears as a spatio-temporal, emotional and strategic keyword.Peer reviewe

Crop Updates 2010 - Genetically Modified Crops, Nutrition and Soils

GENETICALLY MODIFIED CROPS 1. Evaluation of the environmental and economic impact of Roundup Ready® canola in the Western Australian crop production system, James Fisher and Désirée Futures, York, Western Australia, Peter Tozer, PRT Consulting, Armidale NSW 2. Controlling wild radish (Raphanus raphanistrum) in Roundup Ready®1 Canola: Outcomes from the Nufarm 2009 Roundup Ready small plot trial Program, Mike Jackson, Nufarm Australia Limited 3. Weed strategies for glyphosate tolerant crops, John Moore, Department of Agriculture and Food 4. Results of the 2009 Western Australia Roundup Ready® canola trials, Dr James Neilsen, Canola Systems Specialist, Monsanto Australia NUTRITION 5. Modelling P runoff losses from agricultural systems, Geoff Anderson1, Wen Chen1, 2, Richard Bell2 and Ross Brennan1, 1Department of Agriculture and Food, 2School of Environmental Science, Murdoch University 6. Evaluation of deep banded biochars or biochar-mineral complex for increasing wheat yield or replacing fertiliser, Paul Blackwell, Allan Herbert and Stephen Davies, Department of Agriculture and Food 7. Improving fertiliser management: Redefining soil test-crop response relationships for canola in Western Australia, Wen Chen1, 2, Ross Brennan2, Richard Bell1, Mike Bolland2 and Geoff Anderson2, 1School of Environmental Science, Murdoch University, 2Department of Agriculture and Food 8. Phosphorus placement for wheat and lupins in WA cropping systems, 1School of Environmental Science, Murdoch University, 2Department of Agriculture and Food 9. The benefits of fertilising pastures for following crops, James Easton, Ryan Guthrie and Rowan Maddern, CSBP 10. Good nutrition produces high quality wheat in the high rainfall zone of Western Australia, Darren Hughes, Adveco Fertilisers; Wagga Wagga, Robert Belford, Curtin University of Technology, Wal Anderson, Department of Agriculture and Food, and Ian Edwards, Edstar Genetics, Perth 11. Lime to get maximum benefit from soil phosphorus, Reg Lunt and Bill Bowden, Department of Agriculture and Food 12. Variable rate top up N – Is it worth the trouble? Nigel Metz, South East Premium Wheat Growers Association (SEPWA) SOILS 13. Impact of soil inversion, soil dilution and claying on non-wetting sandplain soils, Stephen Davies, Peter Newman and Breanne Best, Department of Agriculture and Food 14. Long term effects of lime application on soil p, crop yields and annual ryegrass competition, Chris Gazey, Department of Agriculture and Food, Joel Andrew, Precision SoilTech, Belmont, Western Australi

Final Results of a Randomized, Phase III Study of Rituximab With or Without Idelalisib Followed by Open-Label Idelalisib in Patients With Relapsed Chronic Lymphocytic Leukemia

PURPOSE A randomized, double-blind, phase III study of idelalisib (IDELA) plus rituximab versus placebo plus rituximab in patients with relapsed chronic lymphocytic leukemia (CLL) was terminated early because of superior efficacy of the IDELA-plus-rituximab (IDELA/R) arm. Patients in either arm could then enroll in an extension study to receive IDELA monotherapy. Here, we report the long-term efficacy and safety data for IDELA-treated patients across the primary and extension studies. PATIENTS AND METHODS Patients were randomly assigned to receive rituximab in combination with either IDELA 150 mg twice daily (IDELA/R; n = 110) or placebo (placebo/R; n = 110). Key end points were progression-free survival (PFS), overall response rate (ORR), overall survival (OS), and safety. RESULTS The long-term efficacy and safety of treatment with IDELA was assessed in 110 patients who received at least one dose of IDELA in the primary study, 75 of whom enrolled in the extension study. The IDELA/R-to-IDELA group had a median PFS of 20.3 months (95% CI, 17.3 to 26.3 months) after a median follow-up time of 18 months (range, 0.3 to 67.6 months). The ORR was 85.5% (94 of 110 patients; n = 1 complete response). The median OS was 40.6 months (95% CI, 28.5 to 57.3 months) and 34.6 months (95% CI, 16.0 months to not reached) for patients randomly assigned to the IDELA/R and placebo/R groups, respectively. Prolonged exposure to IDELA increased the incidence of all-grade, grade 2, and grade 3 or greater diarrhea (46.4%, 17.3%, and 16.4%, respectively), all-grade and grade 3 or greater colitis (10.9% and 8.2%, respectively) and all-grade and grade 3 or greater pneumonitis (10.0% and 6.4%, respectively) but did not increase the incidence of elevated hepatic aminotransferases. CONCLUSION IDELA improved PFS and OS compared with rituximab alone in patients with relapsed CLL. Long-term IDELA was effective and had an expected safety profile. No new IDELA-related adverse events were identified with longer exposure