The Bayesian choice of crop variety and fertilizer dose

Recent contributions to the theory of optimizing fertilizer doses in agricultural crop production have introduced Bayesian ideas to incorporate information on crop yield from several environments and on soil nutrients from a soil test, but they have not used a fully Bayesian formulation. We present such a formulation and demonstrate how the resulting Bayes decision procedure can be evaluated in practice by using Markov chain Monte Carlo methods. The approach incorporates expert knowledge of the crop and of regional and local soil conditions and allows a choice of crop variety as well as of fertilizer level. Alternative dose–response functions are expressed in terms of a common interpretable set of parameters to facilitate model comparisons and the specification of prior distributions. The approach is illustrated with a set of yield data from spring barley nitrogen–response trials and is found to be robust to changes in the dose–response function and the prior distribution for indigenous soil nitrogen.     

Speculative method and Twitter: Bots,energy and three conceptual characters

This paper aims to contribute to recent innovations in social scientific methodology that aspire to address the complex, iterative and performative dimensions of method. In particular, we focus on the becoming‐with character of social events, and propose a speculative method for engaging with the not‐as‐yet. This work, being part of a larger project that uses Speculative Design and ethnographic methods to explore energy‐demand reduction, specifically considers the ways in which energy‐demand reduction features in the Twitter‐sphere. Developing and deploying three automated Bots whose function and communications are at best obscure, and not uncommonly nonsensical, we trace some of ways in which they intervene and provoke. Heuristically, we draw on the ‘conceptual characters’ of idiot, parasite and diplomat in order to grasp how the Bots act within Twitter to evoke the instability and emergent eventuations of energy‐demand reduction, community and related practices. We conclude by drawing out some of the wider implications of this particular enactment of speculative method.     

Benefits of Model-based Drug Development: A Rigorous,Planned Case Study

Model-based drug development (MBDD) is useful to make better quantitative decisions within drug development. However, rigorous evaluation of the benefits has been scarce in the literature. In this study, we take a completed development program, retrospectively repeat it in a virtual setting using MBDD methodologies, and compare it to the traditional drug development process. The conclusion is that the use of MBDD could have facilitated more efficient use of resources.     

Developing Policy in the Face of Scientific Uncertainty: Interpreting 0.3 μT or 0.4 μT Cutpoints from EMF Epidemiologic Studies

There has been considerable scientific effort to understand the potential link between exposures to power-frequency electric and magnetic fields (EMF) and the occurrence of cancer and other diseases. The combination of widespread exposures, established biological effects from acute, high-level exposures, and the possibility of leukemia in children from low-level, chronic exposures has made it both necessary and difficult to develop consistent public health policies. In this article we review the basis of both numeric standards and precautionary-based approaches. While we believe that policies regarding EMF should indeed be precautionary, this does not require or imply adoption of numeric exposure standards. We argue that cutpoints from epidemiologic studies, which are arbitrarily chosen, should not be used as the basis for making exposure limits due to a number of uncertainties. Establishment of arbitrary numeric exposure limits undermines the value of both the science-based numeric EMF exposure standards for acute exposures and precautionary approaches. The World Health Organization's draft Precautionary Framework provides guidance for establishing appropriate public health policies for power-frequency EMF.     

International venture capital research: From cross-country comparisons to crossing borders

Venture capital (VC) has become an international phenomenon, and VC firms are a specific kind of service firm whose characteristics have distinctive implications for international behaviour. There is now a disparate body of research on international aspects of VC across a number of disciplines comprising finance, economics, strategy, entrepreneurship, international business and economic geography. A novel aspect of this paper is that we review and synthesize this disparate literature. A number of research gaps and limitations in the theoretical and methodological approaches involved in previous studies are identified and suggestions made for further research. We show that the vast majority of the literature relates to cross-country comparisons; that is, macro-level comparisons of VC industries across different countries and micro-level comparisons of VC behaviour across countries. From our review of the literature, we argue that an under-researched area concerns the influence of institutional contexts, especially the role of social networks and cultures. Furthermore, our review of the literature indicates that there is a major research gap in relation to work dealing with the crossing of country borders by VC firms. We suggest that resource-based, capabilities, institutional and network theories may be offer insights to further our understanding of the behaviour of VC firms in this area.     

Estimating numbers of infectious units from serial dilution assays

Summary.  The paper concerns the design and analysis of serial dilution assays to estimate the infectivity of a sample of tissue when it is assumed that the sample contains a finite number of indivisible infectious units such that a subsample will be infectious if it contains one or more of these units. The aim of the study is to estimate the number of infectious units in the original sample. The standard approach to the analysis of data from such a study is based on the assumption of independence of aliquots both at the same dilution level and at different dilution levels, so that the numbers of infectious units in the aliquots follow independent Poisson distributions. An alternative approach is based on calculation of the expected value of the total number of samples tested that are not infectious. We derive the likelihood for the data on the basis of the discrete number of infectious units, enabling calculation of the maximum likelihood estimate and likelihood-based confidence intervals. We use the exact probabilities that are obtained to compare the maximum likelihood estimate with those given by the other methods in terms of bias and standard error and to compare the coverage of the confidence intervals. We show that the methods have very similar properties and conclude that for practical use the method that is based on the Poisson assumption is to be recommended, since it can be implemented by using standard statistical software. Finally we consider the design of serial dilution assays, concluding that it is important that neither the dilution factor nor the number of samples that remain untested should be too large.     

Changing society's DNA codes: Democracy and the global movement for community progress measures

This paper examines some critical issues and opportunities for democracy and public policy posed by the growth of the global progress measurement movement. From the democratic perspective, these include: citizen progress measurement as a form of democratic re‐engagement; the re‐examination of democracy and the development of new indicators to define and measure a ‘healthy’ democracy; and the demonstration of clear linkages between healthy regimes, and broader individual and societal wellbeing. In public policy, the global movement challenges two long dominant assumptions: the primacy of continuous economic growth as the key driver of wellbeing; and the ‘inevitability of progress‘. In their place, it offers a more holistic, integrated and nuanced model that recognises the interdependence of economic, social, cultural, environmental and democratic dimensions for genuine wellbeing, progress and sustainability. The paper reviews work in Australia over the past decade at both local community and national levels as examples of these trends, including the development of citizen‐engaged community planning and neighbourhood renewal schemes in which progress and wellbeing indicators play a central role; the development of state‐wide local progress measurement frameworks as part of a commitment to devolved planning and stronger local democracy; and the evolution of national progress measurement systems. The paper concludes with a proposal for a broad community engaged National Development Index (NDI) for Australia.     

The Accessibility of Public Spaces for People with Dementia: a new priority for the 'open city'

The social model of disability de-medicalises disability and politicises it as an issue of universal rights. However, the rights of people with dementia have been less strongly advocated than those of people with physical disabilities. This is particularly the case with environmental planning and design. The needs of people with dementia are now informing the design of residential homes and day centres, but the issue of accessibility to public spaces and amenities has been almost completely neglected. Many outdoor environments such as shopping centres or parks may be inhospitable for people with dementia because they are disorientating, difficult to interpret and navigate, threatening or distressing. The article reviews the literature on indoor design for dementia, reports on research investigating the accessibility of outdoor environments, and describes a new approach using virtual reality technology to enable people with dementia to identify and test outdoor design and planning improvements themselves.