4,679 research outputs found

    Thoughts on financial derivatives, systematic risk, and central banking: a review of some recent developments

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    This paper critically reviews the literature examining the role of central banks in addressing systemic risk. We focus on how the growth in derivatives markets might affect that role. Analysis of systemic risk policy is hampered by the lack of a consensus theory of systemic risk. We propose a set of criteria that theories of systemic risk should satisfy, and we critically discuss a number of theories proposed in the literature. We argue that concerns about systemic effects of derivatives appear somewhat overstated. In particular, derivative markets do not appear unduly prone to systemic disturbances. Furthermore, derivative trading may increase informational efficiency of financial markets and provide instruments for more effective risk management. Both of these effects tend to reduce the danger of systemic crises. However, the complexity of derivative contracts (in particular, their high implicit leverage and nonlinear payoffs) do complicate the process of regulatory oversight. In addition, derivatives may make the conduct of monetary policy more difficult. Most theories of systemic risk imply a critical role for central banks as the ultimate provider of liquidity. However, the countervailing danger of moral hazard must be recognized and addressed through vigilant supervision.Banks and banking, Central ; Derivative securities ; Risk

    Novel Nanomaterials Enable Biomimetic Models of the Tumor Microenvironment

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    In the complex tumor microenvironment, chemical and mechanical signals from tumor cells, stromal cells, and the surrounding extracellular matrix influence all aspects of disease progression and response to treatment. Modeling the physical properties of the tumor microenvironment has been a significant effort in the biomaterials field. One challenge has been the difficulty in altering the mechanical properties of the extracellular matrix without simultaneously impacting other factors that influence cell behavior. The development of novel materials based on nanotechnology has enabled recent innovations in tumor cell culture models. Here, we review the various approaches by which the tumor cell microenvironment has been engineered using natural and synthetic gels. We describe new studies that rely on the unique temporal and spatial control afforded by nanomaterials to produce culture platforms that mimic dynamic changes in tumor matrix mechanics. In addition, we look at the frontier of nanomaterial-hydrogel composites to review new approaches for perturbation of mechanochemical control in the tumor microenvironment

    Scotland Registry for Ankylosing Spondylitis (SIRAS) – Protocol

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    Funding SIRAS was funded by unrestricted grants from Pfizer and AbbVie. The project was reviewed by both companies, during the award process, for Scientific merit, to ensure that the design did not compromise patient safety, and to assess the global regulatory implications and any impact on regulatory strategy.Publisher PD

    Mobilising knowledge in complex health systems: a call to action

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    Worldwide, policymakers, health system managers, practitioners and researchers struggle to use evidence to improve policy and practice. There is growing recognition that this challenge relates to the complex systems in which we work. The corresponding increase in complexity-related discourse remains primarily at a theoretical level. This paper moves the discussion to a practical level, proposing actions that can be taken to implement evidence successfully in complex systems. Key to success is working with, rather than trying to simplify or control, complexity. The integrated actions relate to co-producing knowledge, establishing shared goals and measures, enabling leadership, ensuring adequate resourcing, contributing to the science of knowledge-to-action, and communicating strategically

    Quantifying rate enhancements for acid catalysis in CO 2 -enriched high-temperature water

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    Thermodynamic calculations revealed that 10 to 100-fold increases in reaction rate are obtainable with added CO 2 (0.1–1 MPa) for an acid-catalyzed reaction in high-temperature liquid water (HTW) that is first order in H + concentration. These calculations suggest that CO 2 is most effective as a rate-enhancing additive in HTW at lower temperatures (150–200°C). When compared with increased temperature as a competitive option for accelerating acid-catalyzed reactions in HTW, CO 2 addition generally carries a lower pressure penalty (and no temperature penalty) for the model acid-catalyzed reaction with activation energies of up to 35 kcal/mol. An experimental survey revealed that CO 2 addition is effective for achieving increased reaction rates for dibenzyl ether hydrolysis in HTW, but that bisphenol A cleavage, methyl benzoate hydrolysis, and o -phthalic acid decarboxylation were not significantly impacted by added CO 2 . This behavior is consistent with previous results for these reactions wherein mineral acid, rather than CO 2 , was added to lower the pH. A summary of experimental results reported for reactions in CO 2 -enriched HTW revealed that product yields of some reactions can be increased by a factor of 23 with added CO 2 . Taken collectively, these results suggest that CO 2 addition may be a practical technique for making HTW more attractive as a reaction medium for acid-catalyzed organic synthesis. © 2007 American Institute of Chemical Engineers AIChE J, 2008Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57897/1/11392_ftp.pd

    Length-dependent disassembly maintains four different flagellar lengths in Giardia.

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    With eight flagella of four different lengths, the parasitic protist Giardia is an ideal model to evaluate flagellar assembly and length regulation. To determine how four different flagellar lengths are maintained, we used live-cell quantitative imaging and mathematical modeling of conserved components of intraflagellar transport (IFT)-mediated assembly and kinesin-13-mediated disassembly in different flagellar pairs. Each axoneme has a long cytoplasmic region extending from the basal body, and transitions to a canonical membrane-bound flagellum at the 'flagellar pore'. We determined that each flagellar pore is the site of IFT accumulation and injection, defining a diffusion barrier functionally analogous to the transition zone. IFT-mediated assembly is length-independent, as train size, speed, and injection frequencies are similar for all flagella. We demonstrate that kinesin-13 localization to the flagellar tips is inversely correlated to flagellar length. Therefore, we propose a model where a length-dependent disassembly mechanism controls multiple flagellar lengths within the same cell

    Men in the Remaking: Conversion Narratives and Born-Again Masculinity in Zambia

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    The born-again discourse is a central characteristic of Pentecostal Christianity in Africa. In the study of African Christianities, this discourse and the way it (re)shapes people’s moral, religious, and social identities has received much attention. However, hardly any attention has been paid to its effects on men as gendered beings. In the study of men and masculinities in Africa, on the other hand, neither religion in general nor born-again Christianity in particular are taken into account as relevant factors in the construction of masculinities. On the basis of a detailed analysis of interviews with men who are members of a Pentecostal church in Lusaka, Zambia, this article investigates how men’s gender identities are reshaped by becoming and being born-again and how born-again conversion produces new forms of masculinity. The observed Pentecostal transformation of masculinity is interpreted in relation to men’s social vulnerability, particularly in the context of the HIV epidemic in Zambia
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