171 research outputs found

    Untangling the Conceptual Isssues Raised in Reydon and Scholz’s Critique of Organizational Ecology and Darwinian Populations

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    Reydon and Scholz raise doubts about the Darwinian status of organizational ecology by arguing that Darwinian principles are not applicable to organizational populations. Although their critique of organizational ecology’s typological essentialism is correct, they go on to reject the Darwinian status of organizational populations. This paper claims that the distinction between replicators and interactors, raised in modern philosophy of biology but not discussed by Reydon and Scholz, points the way forward for organizational ecologists. It is possible to conceptualise evolving Darwinian populations providing the inheritance mechanism is appropriately specified. By this approach, adaptation and selection are no longer dichotomised, and the evolutionary significance of knowledge transmission is highlightedPeer reviewe

    Effectiveness of measles vaccination and vitamin A treatment

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    Background The current strategy utilized by WHO/United Nations Children's Fund (UNICEF) to reach the Global Immunization Vision and Strategy 2010 measles reduction goal includes increasing coverage of measles vaccine, vitamin A treatment and supplementation in addition to offering two doses of vaccine to all children

    Contemplating an evolutionary approach to entrepreneurship

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    This paper explores that application of evolutionary approaches to the study of entrepreneurship. It is argued an evolutionary theory of entrepreneurship must give as much concern to the foundations of evolutionary thought as it does the nature entrepreneurship. The central point being that we must move beyond a debate or preference of the natural selection and adaptationist viewpoints. Only then can the interrelationships between individuals, firms, populations and the environments within which they interact be better appreciated

    A review of data needed to parameterize a dynamic model of measles in developing countries

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    <p>Abstract</p> <p>Background</p> <p>Dynamic models of infection transmission can project future disease burden within a population. Few dynamic measles models have been developed for low-income countries, where measles disease burden is highest. Our objective was to review the literature on measles epidemiology in low-income countries, with a particular focus on data that are needed to parameterize dynamic models.</p> <p>Methods</p> <p>We included age-stratified case reporting and seroprevalence studies with fair to good sample sizes for mostly urban African and Indian populations. We emphasized studies conducted before widespread immunization. We summarized age-stratified attack rates and seroprevalence profiles across these populations. Using the study data, we fitted a "representative" seroprevalence profile for African and Indian settings. We also used a catalytic model to estimate the age-dependent force of infection for individual African and Indian studies where seroprevalence was surveyed. We used these data to quantify the effects of population density on the basic reproductive number <it>R</it><sub>0</sub>.</p> <p>Results</p> <p>The peak attack rate usually occurred at age 1 year in Africa, and 1 to 2 years in India, which is earlier than in developed countries before mass vaccination. Approximately 60% of children were seropositive for measles antibody by age 2 in Africa and India, according to the representative seroprevalence profiles. A statistically significant decline in the force of infection with age was found in 4 of 6 Indian seroprevalence studies, but not in 2 African studies. This implies that the classic threshold result describing the critical proportion immune (<it>p</it><sub>c</sub>) required to eradicate an infectious disease, <it>p</it><sub>c </sub>= 1-1/<it>R</it><sub>0</sub>, may overestimate the required proportion immune to eradicate measles in some developing country populations. A possible, though not statistically significant, positive relation between population density and <it>R</it><sub>0 </sub>for various Indian and African populations was also found. These populations also showed a similar pattern of waning of maternal antibodies. Attack rates in rural Indian populations show little dependence on vaccine coverage or population density compared to urban Indian populations. Estimated <it>R</it><sub>0 </sub>values varied widely across populations which has further implications for measles elimination.</p> <p>Conclusions</p> <p>It is possible to develop a broadly informative dynamic model of measles transmission in low-income country settings based on existing literature, though it may be difficult to develop a model that is closely tailored to any given country. Greater efforts to collect data specific to low-income countries would aid in control efforts by allowing highly population-specific models to be developed.</p

    Geography, death and finitude

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    publication-status: PublishedRomanillos J L, 2011. The definitive, peer-reviewed and edited version of this article is published Environment and Planning A, 2011, Vol. 43, Issue 11, pp. 2533 – 2553 DOI: 10.1068/a4474Copyright © 2011 PionDespite growing interest in the geographies of death, loss, and remembrance, comparatively little geographical research has been devoted either to the historical and cultural practices of death, or to an adequate conceptualisation of finitude. Responding to these absences, in this paper I argue for the importance of the notion of finitude within the history and philosophy of geographical thought. Situating finitude initially in the context of the work of Torsten Hägerstrand and Richard Hartshorne, the notion is argued to be both productive of a geographical ethics, and as epistemologically constitutive of phenomenological apprehensions of ‘earth’ and ‘world’. In order to better grasp the sense and genealogy of finitude, I turn to the work of Martin Heidegger, Michel Foucault, and Georges Bataille. These authors are drawn upon precisely because their writings present powerful conceptual frameworks which demonstrate the intimate relations between spatiality, death, and finitude. At the same time, their writings are critically interrogated in the light of perhaps the most important aspect of the conceptual history of finitude: the way in which it has been articulated as a site of anthropocentric distinction. I argue for a critical deconstruction of this anthropocentric basis to finitude; a deconstruction which raises a series of profound questions over the ethics, normativities, and understandings of responsibility shaping contemporary ethical geographies of the human and nonhuman. In so doing, I demonstrate the geographical importance of the notion of finitude for a variety of arenas of debate which include: phenomenological understandings of spatiality; the biopolitical boundaries drawn between human and animal; and contemporary theorisations of corporeality, materiality, and hospitality

    Drinking water sources, mortality and diarrhoea morbidity among young children in northern Ghana.

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    In the Upper East Region of Ghana, considerable resources have been invested in the provision of boreholes. As part of the Ghana Vitamin A Supplementation Trials' Survival Study which was carried out in one of the districts of the Upper East Region between January 1989 and December 1991, data were collected over a period of one calendar year on the drinking water sources used by approximately 13,000 mothers/guardians of over 20,000 children and on the morbidity and mortality experiences of these children. These data were used to describe seasonal and geographical variations in drinking water sources; to look for other predictors of water source use; and to establish whether the drinking water source was associated with the risk of child death or the period prevalence of diarrhoea among young children. Boreholes were used as the main source of drinking water by about 60-70% of respondents. They were used slightly more frequently in the dry season. In the rainy season, the use increased of more traditional sources such as rainwater or holes dug in stream beds. The use of boreholes was greatest in the northern zone of the study area and was more common in those who had had some formal education and were of higher socioeconomic status. Some association was found between reported drinking water source and diarrhoeal morbidity, although this association appeared to be seasonal. No significant association was found between drinking water source and child mortality
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