A Bayesian approach to RFI mitigation

Interfering signals such as Radio Frequency Interference from ubiquitous satellite constellations are becoming an endemic problem in fields involving physical observations of the electromagnetic spectrum. To address this we propose a novel data cleaning methodology. Contamination is simultaneously flagged and managed at the likelihood level. It is modeled in a Bayesian fashion through a piecewise likelihood that is constrained by a Bernoulli prior distribution. The techniques described in this paper can be implemented with just a few lines of code.Comment: 6 pages, 4 figures, accepted by Physical Review D (APS

A comparison of virtual reality anatomy models to prosections in station-based anatomy teaching.

Immersive virtual reality (i-VR) is a powerful tool that can be used to explore virtual models in three dimensions. It could therefore be a valuable tool to supplement anatomical teaching by providing opportunities to explore spatial anatomical relationships in a virtual environment. However, there is a lack of consensus in the literature as to its effectiveness as a teaching modality when compared to the use of cadaveric material. The aim of our study was to compare the effectiveness of i-VR in facilitating understanding of different anatomical regions when compared with cadaveric prosections for a cohort of first- and second-year undergraduate medical students. Students (n = 92) enrolled in the MBBS program at Queen Mary University of London undertook an assessment, answering questions using either Oculus i-VR headsets, the Human Anatomy VR™ application, or prosection materials. Utilizing ANOVA with Sidak's multiple comparison test, we found no significant difference between prosections and i-VR scores in the abdomen (p = 0.6745), upper limb (p = 0.8557), or lower limb groups (p = 0.9973), suggesting that i-VR may be a viable alternative to prosections in these regions. However, students scored significantly higher when using prosections when compared to i-VR for the thoracic region (p < 0.0001). This may be due to a greater need for visuospatial understanding of 3D relationships when viewing anatomical cavities, which is challenged by a virtual environment. Our study supports the use of i-VR in anatomical teaching but highlights that there is significant variation in the efficacy of this tool for the study of different anatomical regions

Inventory of Environmental Impact Monitoring Activities at Wave & Tidal Energy Sites in Europe

The Streamlining of Ocean Wave Farms Impact Assessment (SOWFIA) Project (IEE/09/809/ SI2.558291) is an EU Intelligent Energy Europe (IEE) funded project that draws together ten partners, across eight European countries, who are actively involved with planned wave farm test centres. The SOWFIA project aims to achieve the sharing and consolidation of pan-European experience of consenting processes and environmental and socio-economic impact assessment (IA) best practices for offshore wave energy conversion developments. Studies of wave farm demonstration projects in each of the collaborating EU nations are contributing to the findings. The study sites comprise a wide range of device technologies, environmental settings and stakeholder interests. Through project workshops, meetings, on-going communication and networking amongst project partners, ideas and experiences relating to IA and policy are being shared, and co-ordinated studies addressing key questions for wave energy development are being carried out. The overall goal of the SOWFIA project is to provide recommendations for approval process streamlining and European-wide streamlining of IA processes, thereby helping to remove legal, environmental and socio-economic barriers to the development of offshore power generation from waves. By utilising the findings from technology-specific monitoring at multiple sites, SOWFIA will accelerate knowledge transfer and promote European-wide expertise on environmental and socio-economic impact assessments of wave energy projects. In this way, the development of the future, commercial phase of offshore wave energy installations will benefit from the lessons learned from existing smaller-scale developments

Receiver design for the REACH global 21-cm signal experiment

We detail the the REACH radiometric system designed to enable measurements of the 21-cm neutral hydrogen line. Included is the radiometer architecture and end-to-end system simulations as well as a discussion of the challenges intrinsic to highly-calibratable system development. Following this, we share laboratory results based on the calculation of noise wave parameters utilising an over-constrained least squares approach demonstrating a calibration RMSE of 80 mK for five hours of integration on a custom-made source with comparable impedance to that of the antenna used in the field. This paper therefore documents the state of the calibrator and data analysis in December 2022 in Cambridge before shipping to South Africa.Comment: 30 pages, 19 figure

Factors driving patterns and trends in strandings of small cetaceans

The incidence of cetacean strandings is expected to depend on a combination of factors, including the dis- tribution and abundance of the cetaceans, their prey, and causes of mortality (e.g. natural, fishery bycatch), as well as currents and winds which affect whether carcasses reach the shore. We investigated spatiotemporal patterns and trends in the numbers of strandings of three species of small cetacean in Galicia (NW Spain) and their relationships with meteoro- logical, oceanographic, prey abundance and fishing-related variables, aiming to disentangle the relationship that may exist between these factors, cetacean abundance and mor- tality off the coast. Strandings of 1166 common dolphins (Delphinus delphis), 118 bottlenose dolphins (Tursiops truncatus) and 90 harbour porpoises (Phocoena phocoena) during 2000–2013 were analysed. Generalised additive and generalised additive-mixed model results showed that the variables which best explained the pattern of strandings of the three cetacean species were those related with local ocean meteorology (strength and direction of the North– South component of the winds and the number of days with South-West winds) and the winter North Atlantic Oscil- lation Index. There were no significant relationships with indices of fishing effort or landings. Only bottlenose dolphin showed possible fluctuations in local abundance over the study period. There was no evidence of long-term trends in number of strandings in any of the species and their abun- dances were, therefore, considered to have been relatively stable during the study period.Versión del editor2,01

Charting the course for a Blue Economy in Peru: A Research Agenda

Ocean- and coastal-based economic activities are increasingly recognised as key drivers for supporting global economies. This move towards the “blue economy” is becoming globally widespread, with the recognition that if ocean-based activities are to be sustainable, they will need to move beyond solely extractive and exploitative endeavours, aligning more closely with marine conservation and effective marine spatial planning. In this paper we define the “blue economy” as a “platform for strategic, integrated and participatory coastal and ocean development and protection that incorporates a low carbon economy, the ecosystem approach and human well-being through advancing regional industries, services and activities”. In Peru, while the seas contribute greatly to the national economy, the full potential of the blue economy has yet to be realised. This paper presents the findings of an early career scientist workshop in Lima, Peru, in March 2016. The workshop “Advancing Green Growth in Peru” brought together researchers to identify challenges and opportunities for green growth across three Peruvian economic sectors—tourism, transport and the blue economy with this paper exploring in detail the priorities generated from the “blue economy” stream. These priorities include themes such as marine spatial planning, detailed evaluations of existing maritime industries (e.g. guano collection and fisheries), development of an effective MPA network, support for sustainable coastal tourism, and better inclusion of social science disciplines in understanding societal and political support for a Peruvian blue economy. In addition, the paper discusses the research requirements associated with these priorities. While not a comprehensive list, these priorities provide a starting point for future dialogue on a co-ordinated scientific platform supporting the blue growth agenda in Peru, and in other regions working towards a successful “blue economy”

The stranding anomaly as population indicator: the case of Harbour Porpoise <i>Phocoena phocoena</i> in North-Western Europe

Ecological indicators for monitoring strategies are expected to combine three major characteristics: ecological significance, statistical credibility, and cost-effectiveness. Strategies based on stranding networks rank highly in cost-effectiveness, but their ecological significance and statistical credibility are disputed. Our present goal is to improve the value of stranding data as population indicator as part of monitoring strategies by constructing the spatial and temporal null hypothesis for strandings. The null hypothesis is defined as: small cetacean distribution and mortality are uniform in space and constant in time. We used a drift model to map stranding probabilities and predict stranding patterns of cetacean carcasses under H-0 across the North Sea, the Channel and the Bay of Biscay, for the period 1990-2009. As the most common cetacean occurring in this area, we chose the harbour porpoise <i>Phocoena phocoena</i> for our modelling. The difference between these strandings expected under H-0 and observed strandings is defined as the stranding anomaly. It constituted the stranding data series corrected for drift conditions. Seasonal decomposition of stranding anomaly suggested that drift conditions did not explain observed seasonal variations of porpoise strandings. Long-term stranding anomalies increased first in the southern North Sea, the Channel and Bay of Biscay coasts, and finally the eastern North Sea. The hypothesis of changes in porpoise distribution was consistent with local visual surveys, mostly SCANS surveys (1994 and 2005). This new indicator could be applied to cetacean populations across the world and more widely to marine megafauna