It\u27s A Grand Old Flag To Fight For

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Guidelines for Policy Modellers - 30 years on: New Tricks or Old Dogs?

Systems thinking and the use of modelling to assist in natural resources decision making started in the early 1960’s (Forrester, 1961). In the early 1970’s a multidisciplinary program was established in CSIRO’s Division of Land Resources Management to, among other issues, research and develop models to assist in the resolution of persistent and multi-faceted environmental issues. The authors of this paper were members of that group. We recently decided to look at what has been learned about these reasonably intractable problems over the more than 30 years period since. If it is true that the half life of modelling papers is around eight years and, apparently, decreasing (Haggett, 2005), then we can expect that the wheel has often been reinvented. So we describe issues as they were expressed up to the early 1980’s and compare and contrast them with concerns after the turn of the century in two contexts - the development of systems thinking in modelling and deciding when and how to model. Three general criticisms of systems analysis were evident then: (1) the models were highly mathematical and therefore opaque to the user, and it was hard even for ’experts’ to explain unexpected findings; (2) welfare, as expressed by economic or utilitarian criteria, was considered to be poorly represented in systems practice (systems thinking was being viewed here as rational, while it was slowly being recognized that apparently irrational behaviour is an important part of the social fabric and could not be ignored (Glazer, 1978)); (3) the systems approach relied on lists derived from planners, but in the absence of “systems thinking” guidelines they were only lists of what planners thought of doing, not comprehensive in any strong sense. These three major drawbacks still exist and in much the same form today. Development of systems thinking is now much more widespread. The applications gap does not appear to be filled, though there have been attempts to broaden the client base by participative model construction to reach a consensus of what is agreeable to most stakeholders. “Irrational behaviour” still threatens systems analysis and comes in several forms. There is lack of acceptance that utilitarian criteria should be used to drive the solution. And the consequences of implementing a model’s solution may lead to unforeseen consequences and behaviours by and to affected parties. Very few papers have been written in recent years on guidelines on when to model and when not to do so. There seems to be no connection with earlier publications. The field does not appear to have progressed. We perceive a world in which those who can, model, and those who can’t still feel little need to try. It is to be hoped that interest in the issues of when and why to model will not wane. It would be a shame, perhaps a source of conflict, if modelling remained yet another marker that separates a ‘them’ from an ‘us’. Some of us have now been much closer to decision-makers. Our observations include: (a) Timing is critical in decision-making. Sometimes there are a few hours for deliberation, for others decades. A modeller has to be close to help with the quick ones. Advice that comes too late will not be relevant. (b) Close contact with decision makers is essential, as is their training. (c) A contract from the client is a desirable/necessary precondition. (d) Trust, and lack of it, will always be important in accepting advice. (e) Committees, especially those charged with doing something and feel that they cannot progress without assistance, are good targets. But committees, like modelling contracts, can be solely methods of delaying decisions. (f) Modelling physical and biological systems is less contentious than using utility to guide advice

Incorporating habitat distribution in wildlife disease models: conservation implications for the threat of squirrelpox on the Isle of Arran

Emerging infectious diseases are a substantial threat to native populations. The spread of disease through naive native populations will depend on both demographic and disease parameters, as well as on habitat suitability and connectivity. Using the potential spread of squirrelpox virus (SQPV) on the Isle of Arran as a case study, we develop mathematical models to examine the impact of an emerging disease on a population in a complex landscape of different habitat types. Furthermore, by considering a range of disease parameters, we infer more generally how complex landscapes interact with disease characteristics to determine the spread and persistence of disease. Specific findings indicate that a SQPV outbreak on Arran is likely to be short lived and localized to the point of introduction allowing recovery of red squirrels to pre-infection densities; this has important consequences for the conservation of red squirrels. More generally, we find that the extent of disease spread is dependent on the rare passage of infection through poor quality corridors connecting good quality habitats. Acute, highly transmissible infectious diseases are predicted to spread rapidly causing high mortality. Nonetheless, the disease typically fades out following local epidemics and is not supported in the long term. A chronic infectious disease is predicted to spread more slowly but can remain endemic in the population. This allows the disease to spread more extensively in the long term as it increases the chance of spread between poorly connected populations. Our results highlight how a detailed understanding of landscape connectivity is crucial when considering conservation strategies to protect native species from disease threats

Incorporation of a Late-forming Chondrule into Comet Wild 2

We report the petrology, O isotopic composition, and Al-Mg isotope systematics of a chondrule fragment from the Jupiter-family comet Wild 2, returned to Earth by NASA's Stardust mission. This object shows characteristics of a type II chondrule that formed from an evolved oxygen isotopic reservoir. No evidence for extinct 26Al was found, with (26Al/ 27Al)0 < 3.0 x 10^-6. Assuming homogenous distribution of 26Al in the solar nebula, this particle crystallized at least 3 Myr after the earliest solar system objects--relatively late compared to most chondrules in meteorites. We interpret the presence of this object in a Kuiper Belt body as evidence of late, large-scale transport of small objects between the inner and outer solar nebula. Our observations constrain the formation of Jupiter (a barrier to outward transport if it formed further from the Sun than this cometary chondrule) to be more than 3 Myr after calcium-aluminum-rich inclusionss.Comment: Accepted for publication in ApJ

The influence of fluid intelligence, executive functions and premorbid intelligence on memory in frontal patients

It is commonly thought that memory deficits in frontal patients are a result of impairments in executive functions which impact upon storage and retrieval processes. Yet, few studies have specifically examined the relationship between memory performance and executive functions in frontal patients. Furthermore, the contribution of more general cognitive processes such as fluid intelligence and demographic factors such as age, education, and premorbid intelligence has not been considered. Our study examined the relationship between recall and recognition memory and performance on measures of fluid intelligence, executive functions and premorbid intelligence in 39 frontal patients and 46 healthy controls. Recall memory impairments in frontal patients were strongly correlated with fluid intelligence, executive functions and premorbid intelligence. These factors were all found to be independent predictors of recall performance, with fluid intelligence being the strongest predictor. In contrast, recognition memory impairments were not related to any of these factors. Furthermore, age and education were not significantly correlated with either recall or recognition memory measures. Our findings show that recall memory in frontal patients was related to fluid intelligence, executive functions and premorbid intelligence. In contrast, recognition memory was not. These findings suggest that recall and recognition memory deficits following frontal injury arise from separable cognitive factors. Recognition memory tests may be more useful when assessing memory functions in frontal patients