158 research outputs found

    Instabilities and robust control in natural resource management

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    Most renewable natural resources exhibit marked demographic and environmental stochasticities, which are exarcebated in management decisions by the uncertainty regarding the choice of an appropriate model to describe system dynamics. Moreover, demand and supply analysis often indicates the presence of instabilities and multiple equilibria, which may lead to management problems that are intensified by uncertainty on the evolution of the resource stock. In this paper the fishery management problem is used as an example to explore the potential of robust optimal control, where the objective is to choose a harvesting rule that will work under a range of admissible specifications for the stock-recruitment equation. The paper derives robust harvesting rules leading to a unique equilibrium, which could be helpful in the design of policy instruments such as robust quota systems.info:eu-repo/semantics/publishedVersio

    ‘A Girl's Love’: Lord Alfred Douglas as Homoerotic Muse in the Poetry of Olive Custance

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Women: a Cultural Review on 15/09/2011, available online: http://dx.doi.org/10.1080/09574042.2011.585045.This article explores the relationship between the poet Olive Custance and her husband Lord Alfred Douglas, arguing that Custance constructed Douglas as a male muse figure in her poetry, particularly the sequence ‘Songs of a Fairy Princess’ (Rainbows 1902). The introduction sets out Custance's problematic historical positioning as a ‘decadent’ poet who published nothing following the Great War, but whose work came too late to fit into strictly ‘fin de siècle’ categories. I suggest, however, that Custance's oscillating constructions of gender and sexuality make her more relevant to the concerns of modernity than has previously been acknowledged and her work anticipates what is now termed ‘queer’. The first main section of the article traces the cultural background of the fin de siècle male muse, arguing that Custance's key influences—male homoerotic writers such as Wilde and Pater—meant it was logical that she should imagine the muse as male, despite the problems associated with gender-reversals of the muse-poet relationship which have been identified by several feminist critics. I then move on to focus specifically on how Shakespearean discourses of gender performance and cross-dressing played a key role in Custance and Douglas's courtship, as they exchanged the fluid roles of ‘Prince’, ‘Princess’ and ‘Page’. The penultimate section of the article focuses on discourses of fairy tale and fantasia in Custance's ‘Songs of a Fairy Princess’ sequence, in which these fantasy roles contribute to a construction of Douglas as a feminised object, and the relationship between the ‘Prince’ and ‘Princess’ is described in terms of narcissistic sameness. My paper concludes by tracing the demise of Custance and Douglas's relationship; as Douglas attempted to be more ‘manly’, he sought to escape the role of object, resulting in Custance losing her male muse. But her sexually-dissident constructions of the male muse remain important experiments worthy of critical attention

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Van der Waals Interactions Dominate Ligand−Protein Association in a Protein Binding Site Occluded from Solvent Water

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    In the present study we examine the enthalpy of binding of 2-methoxy-3-isobutylpyrazine (IBMP) to the mouse major urinary protein (MUP), using a combination of isothermal titration calorimetry (ITC), NMR, X-ray crystallography, all-atom molecular dynamics simulations, and site-directed mutagenesis. Global thermodynamics data derived from ITC indicate that binding is driven by favorable enthalpic contributions, rather than a classical entropy-driven signature that might be expected given that the binding pocket of MUP-1 is very hydrophobic. The only ligand−protein hydrogen bond is formed between the side-chain hydroxyl of Tyr120 and the ring nitrogen of the ligand in the wild-type protein. ITC measurements on the binding of IBMP to the Y120F mutant demonstrate a reduced enthalpy of binding, but nonetheless binding is still enthalpy dominated. A combination of solvent isotopic substitution ITC measurements and all-atom molecular dynamics simulations with explicit inclusion of solvent water suggests that solvation is not a major contributor to the overall binding enthalpy. Moreover, hydrogen/deuterium exchange measurements suggest that there is no significant contribution to the enthalpy of binding derived from “tightening” of the protein structure. Data are consistent with binding thermodynamics dominated by favorable dispersion interactions, arising from the inequality of solvent−solute dispersion interactions before complexation versus solute−solute dispersion interactions after complexation, by virtue of poor solvation of the binding pocket

    Strong Solute−Solute Dispersive Interactions in a Protein−Ligand Complex

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    The contributions of solute−solute dispersion interactions to binding thermodynamics have generally been thought to be small, due to the surmised equality between solute−solvent dispersion interactions prior to the interaction versus solute−solute dispersion interactions following the interaction. The thermodynamics of binding of primary alcohols to the major urinary protein (MUP-I) indicate that this general assumption is not justified. The enthalpy of binding becomes more favorable with increasing chain length, whereas the entropy of binding becomes less favorable, both parameters showing a linear dependence. Despite the hydrophobicity of the interacting species, these data show that binding is not dominated by the classical hydrophobic effect, but can be attributed to favorable ligand−protein dispersion interactions

    Combining Monetary and Social Sanctions to Promote Cooperation

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    We employ an experimental approach to consider the impact of a combination of formal and informal sanctions on contribution levels for a specific type of public good. We find that when both sanctions are available, contributions and overall welfare are higher than when only one of the two sanctioning systems is available. The availability of an array of sanctions of varying severity appears to enhance welfare. (JEL C92) Copyright 2005, Oxford University Press.
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