Metal removal by sulphate-reducing bacteria from natural and constructed wetlands

The use of wetlands is a promising technology to treat acid mine drainage, yet there is little understanding of the fundamental biological processes involved. They are considered to centre on the complex anaerobic ecology within sediments and involve the removal of metals by sulphate-reducing bacteria (SRB). These bacteria generate hydrogen sulphide and cause precipitation of metals from solution as the insoluble metal sulphide. Sulphate-reducing bacteria have been isolated from natural and constructed wetlands receiving acid mine drainage. Sulphide production by isolates and removal of the metals iron, manganese and zinc were measured, as well as utilization of a range of carbon sources. Marked ecological differences between the wetlands were reflected in population composition of SRB enrichments, and these consortia displayed significant differences in sulphide generation and rates of metal removal from solution. Rates of metal removal did not correlate with sulphide generation in all cultures, suggesting the involvement of other biological mechanisms of metal removal. Differences in substrate utilization have highlighted the need for further investigation of carbon flow and potential carbon sources within constructed wetlands

Biocontrol in Australia: Can a carp herpesvirus (CyHV-3) deliver safe and effective ecological restoration?

The Australian Government is considering Cyprinid herpesvirus 3 (CyHV-3) for biocontrol of invasive common carp (Cyprinus carpio L.). We review the evidence-base for its potential ecological risks, benefits and effectiveness. Lower carp abundance may boost native fish biomass and improve water clarity, but there is little evidence available to suggest that the virus, alone or used in combination with other methods, can deliver effective or safe biocontrol. Further, the virus may already be present in Australia. Overseas, the virus has caused sporadic and localized mortalities of carp in lakes and rivers, but has generally had no long-term measurable effect on wild carp or native fish populations. The temperature range of disease (18–28 °C), unknown co-factors causing outbreaks, and predictable re-colonization and recruitment boom of immune and virus-resistant carp, following a biocontrol release, remain formidable and unmitigated barriers to success. CyHV-3 infection trials on Australian biota have unexplained high mortality rates of recreationally-important and threatened fishes, and the role of asymptomatic carriers remains uncertain. Finally, Australia has national and international obligations to ensure that there are no perverse outcomes from biocontrol actions. Despite political pressure, there is no environmental justification to rush the release of this virus. To achieve the Government goals of restoring native biodiversity we advocate that key uncertainties, risks and efficacy barriers first need to be addressed. It is only then that viral biocontrol could be considered a viable tool to complement broader ecological restoration strategies for Australia’s waterways

A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics

The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector

A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics

The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector

A Next-Generation Liquid Xenon Observatory for Dark Matter and Neutrino Physics

The nature of dark matter and properties of neutrinos are among the most pressing issues in contemporary particle physics. The dual-phase xenon time-projection chamber is the leading technology to cover the available parameter space for Weakly Interacting Massive Particles (WIMPs), while featuring extensive sensitivity to many alternative dark matter candidates. These detectors can also study neutrinos through neutrinoless double-beta decay and through a variety of astrophysical sources. A next-generation xenon-based detector will therefore be a true multi-purpose observatory to significantly advance particle physics, nuclear physics, astrophysics, solar physics, and cosmology. This review article presents the science cases for such a detector