A Bayesian Model of Pasture Curing

Curing percentage (the percentage of dead material in the sward) is a necessary component of fire behaviour modelling and subsequent fire danger ratings in grasslands. Current methods of estimating curing have limitations. Curing is controlled by leaf turnover in grasses but individual leaf turnover rates of themselves do not give estimates of curing. Bayesian modelling provides the potential to incorporate leaf turnover rates representing the entire life cycle of each leaf into a standalone model of curing from which statistical summaries can be generated and used in field models. In this study, curing percentage was estimated over thermal time for four common C3 grasses, and tested against field data

Leaf Growth and Senescence Rates in Brown-Back Wallaby Grass, \u3cem\u3eRytidosperma duttonianum\u3c/em\u3e

Knowledge of leaf turnover in grasses is necessary to model curing (the accumulation of dead material in the sward), which is not well represented in current pasture growth models, nor for many Australian native species. Leaf turnover begins with the appearance of successive leaves, which elongate until typically, a leaf ligule develops to indicate a mature, fully expanded length. Green leaf life span extends from appearance to the beginning of senescence, which ultimately leads to death (Fig. 1). Here, the individual rates of leaf growth and senescence for the Australian native brown-back wallaby grass, Rytidosperma duttonianum (Cashmore) Connor & Edgar, over the whole life cycle, are reported

A Plant-Physiology Approach to a Fire-y Problem

As vegetation dies, it dries and becomes more flammable. Fire agencies require accurate and timely assessments of curing (the percentage of dead material in the sward) to model grass fire behaviour and calculate fire danger ratings (Cheney and Sullivan 2008). Visual observation is commonplace and the more objective use of the Levy Rod is recommended, although both have drawbacks (Anderson et al. 2011). There is great potential for pasture growth models to provide curing estimates to assist with the management of wild grass fires (Gill et al. 2010). This PhD project focused on plant physiological characters to populate models that could be used to predict curing assessments for fire management purposes

Corporate governance and financial constraints on strategic turnarounds

The paper extends the Robbins and Pearce (1992) two-stage turnaround response model to include governance factors. In addition to the retrenchment and recovery, the paper proposes the addition of a realignment stage, referring specifically to the re-alignment of expectations of principal and agent groups. The realignment stage imposes a threshold that must be crossed before the retrenchment and hence recovery stage can be entered. Crossing this threshold is problematic to the extent that the interests of governance-stakeholder groups diverge in a crisis situation. The severity of the crisis impacts on the bases of strategy contingent asset valuation leading to the fragmentation of stakeholder interests. In some cases the consequence may be that management are prevented from carrying out turnarounds by governance constraints. The paper uses a case study to illustrate these dynamics, and like the Robbins and Pearce study, it focuses on the textile industry. A longitudinal approach is used to show the impact of the removal of governance constraints. The empirical evidence suggests that such financial constraints become less serious to the extent that there is a functioning market for corporate control. Building on governance research and turnaround literature, the paper also outlines the general case necessary and sufficient conditions for successful turnarounds

Evidence that cannabinoid CB1 receptors regulate intraocular pressure via two opposing mechanisms

The cannabinoid signaling system regulates intraocular pressure (IOP) in the mouse via a complex system that includes three receptors: CB1, GPR18 and GPR119. In each case, activating the receptor lowers IOP, but CB1 receptors are found both at sites of aqueous humor inflow and outflow. As such, knockout mice for any of these receptors would be expected to have higher-than average, or at least unchanged, intraocular pressure. The current study investigates the unexpected observation that CB1 knockout mice have lower pressure than wild type counterparts by testing various regulators of cannabinoid signaling in murine models of IOP. We now report that a CB1 antagonist has differential effects on IOP: SR141716 raises IOP in standard light cycle (SLC) but lowers IOP in reverse light cycle (RLC). This is mimicked by ABD1085, a negative allosteric modulator of CB1. CB1 inhibitors lower IOP in both normotensive and hypertensive mouse eyes. The pressure-lowering effect is absent in CB1 knockout mice. IOP rebounds after the end of treatment but shows no sign of desensitization with daily treatment for a week. Unlike the positive cannabinoid effect, antagonist effects are not sex-dependent. We propose that there are two mechanisms of action for CB1, one that lowers IOP upon activation and a second with inverse sign that lowers IOP when CB1 is antagonized. The relatively lower pressure in CB1 knockout mouse eyes suggests that this second negative regulation of IOP is dominant

What is Donald Trump?:Forms of 'Celebrity' in Celebrity Politics

It is widely assumed that Donald Trump is a ‘celebrity politician’, and that he has cashed in his success on the reality show The Apprentice to secure political credibility and attention. In this respect he fits what Matthew Wood et al (2016) have labelled the ‘superstar celebrity politician’. This characterisation is the latest in a number of refinements to the definition and understanding of the celebrity politician. While this is a helpful move, I want to suggest that it might overlook one key dimension of the phenomenon. Definitions of the celebrity politician tend to focus on the source of their ‘celebrity’ – how they became famous, rather than on how they act out their celebrity role. This latter dimension features in media coverage, where journalists and commentators borrow from showbusiness to describe politics, but is less often analysed in the political science literature. It matters because, I want to suggest, celebrity politicians like Trump act as stars, whether of reality television, rock music or film. They do not just resemble stars; they are them. This is evident in how they are represented, how they perform and how their ‘fans’ respond to them. It is also symptomatic of wider changes in the conduct and form of the contemporary, mediatised political realm

Subjective well-being indicators for large-scale assessment of cultural ecosystem services

The substantial importance of cultural benefits as a source of human well-being is increasingly recognised in society-environment interactions. The integration of cultural ecosystem services (CES) into the ecosystem services framework remains a challenge due to the difficulties associated with defining, articulating and measuring CES. We operationalise a novel framework developed by the UK National Ecosystem Assessment that identifies CES as the interactions between environmental spaces (i.e. physical localities or landscapes), and the activities that occur there. We evaluate the benefits of the CES provided by 151 UK marine sites to recreational sea anglers and divers, using subjective well-being indicators. Factor analysis of an online questionnaire with 1220 participants revealed multiple CES benefits that contribute to human wellbeing e.g. including ‘engagement with nature’, ‘place identity’ and ‘therapeutic value’. In addition to regional differences, we also found that biophysical attributes of sites, such as the presence of charismatic species and species diversity, were positively associated with provision of CES benefits. The study provides evidence that could be used to inform designation of protected areas. The indicators used in the study may also be adapted for use across a range of marine and terrestrial spaces for improved integration of CES in environmental decisionmaking

Developments in unsteady pipe flow friction modelling

This paper reviews a number of unsteady friction models for transient pipe flow. Two distinct unsteady friction models, the Zielke and the Brunone models, are investigated in detail. The Zielke model, originally developed for transient laminar flow, has been selected to verify its effectiveness for "low Reynolds number" transient turbulent flow. The Brunone model combines local inertia and wall friction unsteadiness. This model is verified using the Vardy's analytically deduced shear decay coefficient C* to predict the Brunone's friction coefficient k rather than use the traditional trial and error method for estimating k. The two unsteady friction models have been incorporated into the method of characteristics water hammer algorithm. Numerical results from the quasi-steady friction model and the Zielke and the Brunone unsteady friction models are compared with results of laboratory measurements for water hammer cases with laminar and low Reynolds number turbulent flows. Conclusions about the range of validity for the three friction models are drawn. In addition, the convergence and stability of these models are addressed.Anton Bergant, Angus Ross Simpson, John Vìtkovsk

Assessment of impacts on ecosystem services provided by geodiversity in highly urbanised areas: a case study of the Taubaté Basin, Brazil

This work presents a method to identify, to evaluate and to quantify the losses of the offer of ecosystem services provided by geodiversity, using as a case study the Taubaté Basin region, a highly urbanized portion of southeastern São Paulo State, Brazil. Our method considers not only the qualitative analysis of the abiotic as- pects, but also the historical and cultural context, in which the geodiversity elements are crucial for local economy development. The method is based on: i) Qualitative evaluation and definition of six Essential Geodiversity Variables (EGVs), used as the basis for the identification of 53 ecosystem services distributed into four functions: regulating, supporting, provisioning, and cultural; ii) Definition of land use categories based on two land use maps elaborated in order to compare the transformation occurred in the region between 1986 and 2016; iii) Quantification and evaluation of the impacts on the offer of ecosystem services caused by land use transformations occurred in region in a 30–year gap. The results showed that anthropogenic action is the main factor that alter the availability of local services, with emphasis on the supply of water, soils and mineral resources, and its potentially influence on the quality of life of certain species. We reinforce the view that public policies on land management and planning should consider the ecosystem assessment, as it provides evidence to propose actions to mitigate impacts and for environmental compensation, favoring the sustainable use of re- sources by society.The authors would like to thank CAPES for the Academic Mobility Program PDSE Scholarship / Process Nr. 88,881.135227 / 2016–01 and for the PhD research scholarship in Brazil awarded to the first author