Practical guidelines for modelling post-entry spread in invasion ecology

In this article we review a variety of methods to enable understanding and modelling the spread of a pest or pathogen post-entry. Building upon our experience of multidisciplinary research in this area, we propose practical guidelines and a framework for model development, to help with the application of mathematical modelling in the field of invasion ecology for post-entry spread. We evaluate the pros and cons of a range of methods, including references to examples of the methods in practice. We also show how issues of data deficiency and uncertainty can be addressed. The aim is to provide guidance to the reader on the most suitable elements to include in a model of post-entry dispersal in a risk assessment, under differing circumstances. We identify both the strengths and weaknesses of different methods and their application as part of a holistic, multidisciplinary approach to biosecurity research

An assessment of the benefits of yellow Sigatoka (Mycosphaerella musicola) control in the Queensland Northern Banana Pest Quarantine Area

The banana leaf spotting disease yellow Sigatoka is established and actively controlled in Australia through intensive chemical treatments and diseased leaf removal. In the State of Queensland, the State government imposes standards for de-leafing to minimise the risk of the disease spreading in 6 banana pest quarantine areas. Of these, the Northern Banana Pest Quarantine Area is the most significant in terms of banana production. Previous regulations imposed obligations on owners of banana plants within this area to remove leaves from plants with visible spotting on more than 15 per cent of any leaf during the wet season. Recently, this leaf disease threshold has been lowered to 5 per cent. In this paper we examine the likely impact this more-costly regulation will have on the spread of the disease. We estimate that the average net benefit of reducing the diseased leaf threshold is only likely to be $1.4 million per year over the next 30 years, expressed as the annualised present value of tightened regulation. This result varies substantially when the timeframe of the analysis is changed, with shorter time frames indicating poorer net returns from the change in protocols. Overall, the benefit of the regulation change is likely to be minor

Invasive alien species in the food chain : advancing risk assessment models to address climate change, economics and uncertainty

Economic globalization depends on the movement of people and goods between countries. As these exchanges increase, so does the potential for translocation of harmful pests, weeds, and pathogens capable of impacting our crops, livestock and natural resources (Hulme 2009), with concomitant impacts on global food security (Cook et al. 2011)

Individual-based modelling of moth dispersal to improve biosecurity incursion response

1. Some biosecurity systems aimed at reducing the impacts of invasive alien species that employ sentinel trapping systems to detect the presence of unwanted organisms. Once detected, the next challenge is to locate the source population of the invasive species. Tools that can direct search efforts towards the most likely sources of a trapped invasive alien species can improve the chance of rapidly delimiting and eradicating the local population and may help to identify the original introduction pathway. Ground-based detection and delimitation surveys can be very expensive, and methods to focus search efforts to those areas most likely to contain the target organisms can make these efforts more effective and efficient. 2. An individual-based semi-mechanistic model was developed to simulate the spatio-temporal dispersal patterns of an invasive moth. The model combines appetitive and pheromone anemotaxis behaviours in response towind, temperature and pheromone conditions. The modelwas trained using data from a series ofmark-release-recapture experiments on painted applemoth Teia anartoides. 3. The model was used to create hindcast simulations by reversing the time course of environmental conditions. The ability of the model to encompass the release location was evaluated using individual trap locations as starting points for the hindcast simulations. 4. The hindcast modelling generated a pattern of moth flights that successfully encompassed the origin from 86%of trap locations, representing 95%of the 1464 recaptures observed in the mark- release-recapture experiments. 5. Comparing the guided search area defined using the hindcast model with the area of a simple point-diffusion search strategy revealed an optimized search strategy that combined searching a circle of 1 km radius around the trap followed by the area indicated by hindcast model predictions. 6. Synthesis and applications. Incorporating this novel moth dispersal model into biosecurity sentinel systems will allow incursion managers to direct search effort for the proximal source of the incursion towards those areas most likely to contain a local infestation. Such targeted effort should reduce the costs and time taken to detect the proximal source of an incursion. (Résumé d'auteur

Uncertainty and sensitivity analysis in quantitative pest risk assessments : practical rules for risk assessors

Quantitative models have several advantages compared to qualitative methods for pest risk assessments (PRA). Quantitative models do not require the definition of categorical ratings and can be used to compute numerical probabilities of entry and establishment, and to quantify spread and impact. These models are powerful tools, but they include several sources of uncertainty that need to be taken into account by risk assessors and communicated to decision makers. Uncertainty analysis (UA) and sensitivity analysis (SA) are useful for analyzing uncertainty in models used in PRA, and are becoming more popular. However, these techniques should be applied with caution because several factors may influence their results. In this paper, a brief overview of methods of UA and SA are given. As well, a series of practical rules are defined that can be followed by risk assessors to improve the reliability of UA and SA results. These rules are illustrated in a case study based on the infection model of Magarey et al. (2005) where the results of UA and SA are shown to be highly dependent on the assumptions made on the probability distribution of the model inputs

'Raising the bar' : improving the standard and utility of weed and invasive plant research

Fil: Murray, Justine V.. Water for Healthy Country Flagship; AustraliaFil: Lehnhoff, Erik A.. Montana State University; Estados UnidosFil: Neve, Paul. University of Warwick; Reino UnidoFil: Poggio, Santiago Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Webber, Bruce L.. CSIRO Ecosystems Sciences; Australia. The University of Western Australia; Australi

Objective functions for comparing simulations with insect trap catch data

Targeted surveillance of high risk invasion sites using insect traps is becoming an important tool in border biosecurity, aiding in early detection and subsequent monitoring of eradication attempts. The mark-release-recapture technique is widely used to study the dispersal of insects, and to generate unbiased estimates of population density. It may also be used in the biosecurity context to quantify the efficacy of surveillance and eradication monitoring systems. Marked painted apple moths were released at three different locations in Auckland, New Zealand over six weeks during a recent eradication campaign. The results of the mark-release-recapture experiment were used to parameterise a process-based mechanistic dispersal model in order to understand the moth dispersal pattern in relation to wind patterns, and to provide biosecurity agencies with an ability to predict moth dispersal patterns. A genetic algorithm was used to fit some model parameters. Different objective functions were tested: 1) Cohen’s Kappa test, 2) the sum of squared difference on trap catches, 3) the sum of squared difference weighted by distance from the release site, 4) the sum of squared difference weighted on distance between best-fit paired data. The genetic algorithm proved to be a powerful fitting method, but the model results were highly dependant on the objective function used. Objective functions for fitting spatial data need to characterise spatial patterns as well as density (ie. recapture rate). For fitting stochastic models to datasets derived from stochastic spatial processes, objective functions need to accommodate the fact that a perfect fit is practically impossible, even if the models are the same. Applied on mark-release-recapture data, the Cohen’s Kappa test and the sum of squared difference on trap catches captured respectively the distance component of the spatial pattern and the density component adequately but failed to capture both requirements whereas the sum of squared difference weighted by distance from the release site did. However, in order to integrate the stochastic error generated by the model underlying stochastic process, only the sum of squared difference weighted on distance between best-fit paired data was adequate. The relevance of each of the fitting methods is detailed, and their respective strengths and weaknesses are discussed in relation to their ability to capture the spatial patterns of insect recaptures

Keep it clean: can blockchain change the nature of land registry in developing countries?

The global economy is constantly exposed to disruptive technologies. Take the example of telecommunications: it was not long ago that everything revolved around landlines. Households would go to huge lengths to ensure they were well-serviced with fixed-line infrastructure, while those left out endured long travel times for everyday activities like managing a business or connecting with family and friends. Those days now seem like a bygone era. The mobile phone changed everything

Caring for Individuals Who Have used Methamphetamine: A Study Exploring the Experiences of West Australian Nurses Working in An Authorised Mental Health Institute

Background: Methamphetamine (MA) use in Australia has stabilized over the last 22 years, however changing routes of administration and increased purity of the drug has led to greater rates of physical dependency and higher rates of cardiovascular, neurological, and mental health complications. Challenges managing MA related presentations have been reported in Australian Emergency Departments (ED’s), with limited research considering nurses’ experience treating individual(s) who use MA (IWUM) and require prolonged mental health care. Purpose: The aim of this study was to understand nurses’ experiences who care for IWUM in a West Australian hospital’s inpatient mental health service. Methods: Interpretive phenomenological analysis was the chosen methodology for this study. Purposive sampling and one-on-one interviews were conducted with 10 nurses to explore their experiences providing mental health care for IWUM. Results: Three superordinate themes emerged to describe the nurses’ experiences of caring for IWUM across different inpatient mental health services. These included; “Hit by the Storm” [presentations in Mental Health Observation Area (MHOA/ED)] “Working in the Rain” [Authorized Mental Health Unit (AMHU)], and “After the Storm” (discharge and community support services). The nurses highlighted the most acute phase of care was the initial presentation to ED, as IWUM often arrived intoxicated by the drug. The risk management strategies used by the nurses interviewed to manage aggressive behaviour in ED were notably Intravenous (IV) sedation, restraint, and security. Most IWUM who recovered quickly and showed signs of compliance were either discharged directly from ED or monitored in MHOA then discharged within 72 hours. A small proportion of IWUM who experienced drug induced psychotic symptoms were admitted to AMHU, where many nurses felt they had less access to medical resources, relied on their colleagues, security, and the Alcohol and Other Drug (AOD) community liaison team for support to safely manage these patients. Training to provide specialized care for IWUM, discharge planning and community follow up were areas viewed as inadequate or needing improvement. The high rate of continued MA use and representations also raised stigma among nurses caring for IWUM. Conclusion: Nurses associated the highest levels of acuity with their experiences caring for patients intoxicated by MA in ED/MHOA and reporting a perceived reduction of acuity when working with the small cohort of IWUM who were admitted to the AMHU. Nurses acknowledged overcoming stigmatising behaviours, required specialised MA training and education, and valued the support received from AOD nurses when caring for IWUM

Making room for Africa’s urban billion

By 2050, more than a billion people will be living in African cities and towns. As more and more of the continent’s population – 60% of whom live in the countryside – move to urban areas, pressures on land can only intensify. How should we make room for this massive urban expansion? How will city structures have to change to accommodate Africa’s urban billion? And could well-directed policy help spring African cities out of the low-development trap? These questions were at the core of discussions at the World Bank’s 5th Urbanisation and Poverty Reduction research conference on 6 September 2018