87 research outputs found
Wind engineering study of the Interama Tower of the Sun
CER74-75JAP-JEC23.Includes bibliographical references (pages 34-35).January 1975.For Ferendino-Grafton-Spillis-Candela.Support for this investigation was provided by Ferendino-Grafton-Spillis-Candela Architects and the Interama Authority of Miami
Listeria monocytogenes Traffics from Maternal Organs to the Placenta and Back
Infection with Listeria monocytogenes is a significant health problem during pregnancy. This study evaluates the role of trafficking between maternal organs and placenta in a pregnant guinea pig model of listeriosis. After intravenous inoculation of guinea pigs, the initial ratio of bacteria in maternal organs to placenta was 10(3)–10(4):1. Rapid increase of bacteria in the placenta changed the ratio to 1:1 after 24 h. Utilizing two wild-type strains, differentially marked by their susceptibility to erythromycin, we found that only a single bacterium was necessary to cause placental infection, and that L. monocytogenes trafficked from maternal organs to the placenta in small numbers. Surprisingly, bacteria trafficked in large numbers from the placenta to maternal organs. Bacterial growth, clearance, and transport between organs were simulated with a mathematical model showing that the rate of bacterial clearance relative to the rate of bacterial replication in the placenta was sufficient to explain the difference in the course of listeriosis in pregnant versus nonpregnant animals. These results provide the basis for a new model where the placenta is relatively protected from infection. Once colonized, the placenta becomes a nidus of infection resulting in massive reseeding of maternal organs, where L. monocytogenes cannot be cleared until trafficking is interrupted by expulsion of the infected placental tissues
Computational and mathematical approaches to societal transitions
After an introduction of the theoretical framework and concepts of transition studies, this article gives an overview of how structural change in social systems has been studied from various disciplinary perspectives. This overview first leads to the conclusion that computational and mathematical approaches and their practical form, modeling, up till now, have been almost absent in the research and theorizing of structural change or transitions in social systems. Second, this review of the social science literature suggests numerous theoretical constructs relevant for transition modeling. Relevant concepts include the conceptualization of the micro-to-macro link, the importance of explaining both stability and change, quantitative and qualitative definitions of structural change, the use of dichotomies, synchronic and diachronic reasoning in explaining structural change, definitions of basic patterns of social change, the conceptualization of resistance to change and intentional and normative aspects of social change. This article employs these theoretical concepts to describe and discuss the models presented in this special issue in order to develop an understanding of what exactly entails a computational or mathematical approach to societal transitions
Susceptibility of murine induced pluripotent stem cell-derived cardiomyocytes to hypoxia and nutrient deprivation
The limits of partnership : an exit-action strategy for local democratic inclusion
The challenge of enhancing the `democratic anchorage' of partnerships has become a central concern in policy studies. Radical reform proposals designed to level the deliberative playing field include community veto powers and the appointment of neutral arbiters. Welcome as they would be, however, it is questionable whether such reforms would overcome power asymmetries in the partnership arena. A study of the local politics of social inclusion in two UK cities, Dundee and Hull, suggests that managerialism, driven by national governments, is eroding the prospects for partnership democratisation. But more significantly for the reformist agenda, public managers and community activists think in incompatible frames about the role of partnerships and in ways that are not understood by the other party. Non-communication undermines the prospects for an equitable democratic consensus. Insights from Bourdieu suggest that even in environments more favourable to equitable democratic discourse than those in Dundee and Hull, subtle manifestations of power in culture, discourse and bearing would undermine the potential for a Habermasian consensus between radically unequal actors. In a radical departure from the network governance paradigm, it is therefore argued that empowerment may depend less on enhanced network democracy than on strong independent community organisation capable of acting separately and coercively against governing institutions and elites - an exit-action strategy. These preliminary conclusions point to a substantial research agenda on the politics of the state-civil society nexus
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