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Introduction: Autonomous underwater vehicles (AUVs) are required to thoroughly scan designated areas during underwater missions. They typically follow a zig-zag trajectory to achieve full coverage. However, effective coverage can be challenging in complex environments due to the accumulation and drift of navigation errors. Possible solutions include surfacing for satellite positioning or underwater acoustic positioning using transponders on other vehicles. Nevertheless, surfacing or active acoustics can compromise stealth during reconnaissance missions in hostile areas by revealing the vehicle's location.

A new device, currently being designed by a University of Adelaide PhD candidate, could help to close a loophole currently being exploited by illegal wildlife traffickers.

International limits on the concentrations of living organisms in ballast water are now in force for commercial ships. Microscopy-based, "direct count" assays estimate the concentrations of organisms. These assays are used in performance tests of Ballast Water Management Systems (BWMSs), which are shipboard technologies designed to reduce living organisms in ballast water to below the discharge limits. Here, we examine the factors that affect the method detection limit (MDL) of direct count assays. The MDL depends upon the volumes sampled, concentrated (or diluted), and analyzed, so the MDL will vary as these volumes vary from analysis-to-analysis. Decreasing the MDL to detect exceedingly rare individuals (e.g., ~1 individual per m3 or fewer) is possible, but problematic, given the challenges in analyzing dynamic communities of living organisms: increasing sample and analysis volumes to lower the MDL will likely accelerate the loss of individuals, as organisms are concentrated to several orders of magnitude above in situ concentrations and held for extended times. Results of direct count assays may be widely disseminated as an indicator of the performance of BWMSs, and when no organisms are detected, concentrations may be shown as "0 organisms per m3 or mL" rather than "-provides context to results and transparency into the sensitivity of the assay.

DARPA selects Serco Inc. for novel design named Defiant.

As the current COVID-19 pandemic and the resulting crew change crisis exacerbates the mental health problem faced by seafarers, various maritime stakeholders have mobilised their resources and strengths to provide a variety of supportive measures to address the issue. This paper aims to find out what measures have been adopted in the industry and how widely they have been experienced/received by seafarers and evaluate their effectiveness. To achieve this aim, this research employed a mixed methods design involving qualitative interviews with 26 stakeholders and a quantitative questionnaire survey of 817 seafarers. The research identified a total number of 22 mental health support measures, all of which were perceived to have contributed positively to seafarers' mental health. However, not all of them were widely available to or utilised by seafarers. The findings also highlighted the importance of family, colleagues, shipping companies, and government agencies, as they are associated with the most effective support measures, namely communication with family, timely crew changes, being prioritised for vaccination, being vaccinated, and a positive and collegial atmosphere on-board. Based on the findings, recommendations are provided.