Probabilistic Inverse Method for Source Localization Applied to ETEX and the 2017 Case of Ru-106 including Analyses of Sensitivity to Measurement Data

In recent years, cases of unexplained, elevated levels of radioactive particles have demonstrated an increasing need for efficient and robust source localization methods. In this study, a Bayesian method for source localization is developed and applied to two cases. First, the method is validated against the European tracer experiment (ETEX) and then applied to the still unaccounted for release of Ru-106 in the fall of 2017. The ETEX dataset, however, differs significantly from the Ru-106 dataset with regard to time resolution and the distance from the release site to the nearest measurements. Therefore, sensitivity analyses are conducted in order to test the method’s sensitivity to these parameters. The analyses show that the resulting source localization depends on both the observed temporal resolution and the existence of sampling stations close to the source. However, the method is robust, in the sense that reducing the amount of information in the dataset merely reduces the accuracy, and hence, none of the results are contradictory. When applied to the Ru-106 case, the results indicate that the Southern Ural region is the most plausible release area, and, as hypothesized by other studies, that the Mayak nuclear facility is the most likely release location.

Determining salmon provenance with automated otolith reading

Synthetic otolith marks are used at hundreds of hatcheries throughout the Pacific Rim to record the release location of salmon. Each year, human readers examine tens of thousands of otolith samples to identify the marks in salmon that are caught. The data inform dynamic management practices that maximize allowable catch while preserving populations, and guide hatchery investments. However, the method is limited by the time required to process otoliths, the inability to distinguish between wild and un-marked hatchery fish, and in some cases classification processes are limited by the subjective decisions of human readers. Automated otolith reading using computer vision has the potential to improve on all three of these limitations. Our work advances the field of automated otolith reading through a novel otolith classification algorithm that uses two neural networks trained with an adversarial algorithm to achieve 93% classification accuracy between four hatchery marks and unmarked otoliths. The algorithm relies on hemisection images of the otolith exclusively: no additional biological data are needed. Our work demonstrates a novel technique with modest training requirements that achieves unprecedented accuracy. The method can be easily adopted in existing otolith labs, scaled to accommodate additional marks, and does not require tracking additional information about the fish that the otolith was retrieved from.

Contaminant Source Identification from Finite Sensor Data: Perron–Frobenius Operator and Bayesian Inference

Sensors in the built environment ensure safety and comfort by tracking contaminants in the occupied space. In the event of contaminant release, it is important to use the limited sensor data to rapidly and accurately identify the release location of the contaminant. Identification of the release location will enable subsequent remediation as well as evacuation decision-making. In previous work, we used an operator theoretic approach—based on the Perron–Frobenius (PF) operator—to estimate the contaminant concentration distribution in the domain given a finite amount of streaming sensor data. In the current work, the approach is extended to identify the most probable contaminant release location. The release location identification is framed as a Bayesian inference problem. The Bayesian inference approach requires considering multiple release location scenarios, which is done efficiently using the discrete PF operator. The discrete PF operator provides a fast, effective and accurate model for contaminant transport modeling. The utility of our PF-based Bayesian inference methodology is illustrated using single-point release scenarios in both two and three-dimensional cases. The method provides a fast, accurate, and efficient framework for real-time identification of contaminant source location.

Assessing Damages to Built and Natural Environments: Linking Hydrodynamic and Geospatial Enviro-Economical Models

In this study, a novel framework was developed to provide a holistic damage assessment caused by severe hydrologic events whether individually or as a compound event. The novel framework uses a developed hurricane-specific water quality model, Environmental Fluid Dynamic Code-Storm Surge model (EFDC-SS) and an ArcGIS-based framework, the Facility Economic Damage and Environmental Release Planning (FEDERAP) to assess damages to the built and natural environment. The developed framework could be used to compare different hurricanes and storms with a focus on land inundation, spill destination in both land and water and their associated risks, as well as economic loss including both physical and secondary losses. The results showed different spreading mechanisms during surge and rainfall-based hurricanes. While storm surge pushed contaminants (from spills) upstream, the rainfall-based hurricane caused a larger footprint of contamination on land. Though different in spreading patterns, spills during both hurricane types can widely spread miles away from the release location in a very short period of time. The FEDERAP economic loss model showed that facility area, average land elevation, the number of storage tanks and process units at the facility, and daily production are key drivers in the calculated total losses for a given hydrologic event.

Oil Spill Modeling for the Enbridge Line 3 Replacement Program with Response for Planning, Preparedness, and Environmental Purposes

ABSTRACT Oil spill trajectory and fate modeling and analyses were performed to support evaluation of the downstream movement, behavior, timing, and potential ecological and human health risks resulting from hypothetical releases of crude oil from the proposed Enbridge Line 3 Replacement Program. The investigation involved assessing multiple hypothetical pipeline releases into terrestrial and aquatic environments. The quantitative assessment of the three-dimensional movement (i.e. trajectory) and behavior (i.e. fate) of released oil used site-specific environmental and geographic conditions, including seasonal and hydrographic information. The main questions being addressed included: What is the expected spatial extent, timing, and magnitude of hydrocarbon contamination from an unmitigated release?How do changes in the release location and release volume affect the ultimate trajectory, fate, and number of potentially susceptible resources.How does the inclusion of modeled response options change predictions (i.e. unmitigated vs. response mitigated scenarios)? The 2-dimensional OILMAPLand and 3-dimensional SIMAP computational oil spill models were used to assess hypothetical crude oil release scenarios into the Mississippi River near Palisade, MN. Results were presented in an Environmental Impact Statement (EIS) and an Assessment of Accidental Releases (AAR) presented to the Minnesota Department of Commerce Energy Environmental Review and Analysis (MN DOC EERA) and the Pollution Control Administration (MN PCA) as both oral and written testimony. The findings demonstrated realistic predictions of containment and collection efficiencies following an accidental release and aided regulators in the decision-making process for the project.

Aphid colony duration does not limit the abundance of Harmonia axyridis in the mediterranean area

There is a lot of information on the factors limiting the distributions of species in their native areas, but much less on those limiting potential changes in distributions of species that are currently spreading outside their present range, especially invasive species. However, this information is often quite essential, as it enables the prediction of future spatial distributions and local abundances of invasive species and the potential effect they may have on people and crops. Arising from glasshouse escapes in North America and the Netherlands, the invasive ladybird, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), originally from the east Palearctic, has now spread across the whole of North America and most of Europe, both of which caused serious concern. Recent observations show that the spread of H. axyridis towards the equator is limited. For example, it is quite rare in the Mediterranean area and its northward spread in South America is also quite slow, as if there was something limiting its spread towards the equator. European literature indicates it is neither climate, nor the distance of the Mediterranean from the original release location in the Netherlands. Therefore, we hypothesized that it may be biotic factors. In particular, the duration of colonies of prey (colony is the set of individuals in one patch, usually on one plant) that becomes shorter as one approaches the equator. This may lower the fitness of the predator and subsequently lead to low population densities. We test here, whether the duration of aphid colonies is shorter in the Mediterranean area than in Central Europe. Unfortunately, our data does not support this hypothesis. Therefore, the question of what limits the distribution of H. axyridis towards the equator remains to be resolved.

Simulating the Trajectory and Biomass Growth of Free-Floating Macroalgal Cultivation Platforms along the U.S. West Coast

Trajectory tracking and macroalgal growth models were coupled to support a novel macroalgae-harvesting concept known as the Nautical Off-shore Macroalgal Autonomous Device (NOMAD). The NOMAD consists of 5 km long carbon-fiber longlines that are seeded and free float southward along the U.S. West Coast for approximately 3 months before harvesting off the California coast, taking advantage of favorable environmental conditions. The trajectory and macroalgal growth models were applied to answer planning questions pertinent to the techno-economic analysis such as identifying the preferred release location, approximate pathway, timing until harvest, and estimated growth. Trajectories were determined with the General NOAA Operational Modeling Environment (GNOME) model, using 11 years of current and wind data, determining probabilities by running nearly 40,000 Monte Carlo simulations varying the start time and location. An accompanying macroalgal growth model was used to estimate the growth of macroalgae based on the trajectory tracks and environmental forcing products, including light, temperature and nutrients. Model results show that NOMAD lines transit south in the months of April to September due to seasonal currents, taking approximately 3 months to reach Southern California. During transit, NOMAD lines are dispersed but typically avoid beaching or passing through marine sanctuaries. NOMAD lines can yield up to 30 kg wet weight per meter of cultivation line.

Mobile applications addressing violence against women: a systematic review

IntroductionViolence against women is a pressing global health problem that is being met with a new intervention strategy—mobile applications. With this systematic review, we provide an initial analysis and functional categorisation of apps addressing violence against women.MethodsWe conducted a systematic online search conforming with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify apps addressing violence against women in five World Bank regions (Europe and Central Asia; North America, Latin America and the Caribbean; Middle East and North Africa; South Asia; and sub-Saharan Africa). Applications with location of initiation in mentioned regions and ≥100 downloads were included. Data on sector, target group(s), year of release, location of initiation and implementation were extracted. By means of a structured qualitative content analysis, applications were then categorised according to their main functions.ResultsOf 327 relevant applications, 171 were included into the systematic review and assigned to one of five identified categories of main functions, respectively: emergency, avoidance, education, reporting and evidence building, and supporting apps. The largest proportion (46.78%) consisted of emergency apps, followed by education, reporting and evidence building, supporting and avoidance apps in descending order. With regards to the geographical distribution of app categories, significant (χ2(20)=58.172; p=0.000) differences among the included regions were found.ConclusionA vast proportion of apps addressing violence against women primarily draw on one-time emergency or avoidance solutions, as opposed to more preventative approaches. Further research is necessary, critically considering questions of data security, personal safety and efficacy of such mobile health interventions.