371 research outputs found
Untangling the Conceptual Isssues Raised in Reydon and Scholzâs Critique of Organizational Ecology and Darwinian Populations
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 ecologyâs 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
Estimates of measles case fatality ratios: a comprehensive review of community-based studies.
BACKGROUND: Global deaths from measles have decreased notably in past decades, due to both increases in immunization rates and decreases in measles case fatality ratios (CFRs). While some aspects of the reduction in measles mortality can be monitored through increases in immunization coverage, estimating the level of measles deaths (in absolute terms) is problematic, particularly since incidence-based methods of estimation rely on accurate measures of measles CFRs. These ratios vary widely by geographic and epidemiologic context and even within the same community from year-to-year. METHODS: To understand better the variations in CFRs, we reviewed community-based studies published between 1980 and 2008 reporting age-specific measles CFRs. RESULTS: The results of the search consistently document that measles CFRs are highest in unvaccinated children under age 5 years; in outbreaks; the lowest CFRs occur in vaccinated children regardless of setting. The broad range of case and death definitions, study populations and geography highlight the complexities in extrapolating results for global public health planning. CONCLUSIONS: Values for measles CFRs remain imprecise, resulting in continued uncertainty about the actual toll measles exacts
Local structure evolution in polycrystalline ZnMgO () studied by Raman and by synchrotron x-ray pair distribution analysis
The local structures of ZnMgO alloys have been studied by Raman
spectroscopy and by synchrotron x-ray pair distribution function (PDF)
analysis. Within the solid solution range () of
ZnMgO, the wurtzite framework is maintained with Mg homogeneously
distributed throughout the wurtzite lattice. The Raman line
of ZnMgO displays systematic changes in response to the evolution
of the crystal lattice upon the Mg-substitution. The red-shift and broadening
of the mode are explained by the expansion of hexagonal
-dimensions, and compositional disorder of Zn/Mg, respectively. Synchrotron
x-ray PDF analyses of ZnMgO reveal that the Mg atoms have a
slightly reduced wurtzite parameter and more regular tetrahedral bond
distances than the Zn atoms. For both Zn and Mg, the internal tetrahedral
geometries are independent of the alloy composition.Comment: 10 pages, 12 figures RevTe
Fat, Queer, Dead: âObesityâ and the Death Drive
That contemporary discourses of the âobesity epidemicâ are engaged in the construction of fatness as pathological, immoral and socially undesirable has been the subject much recent critical inquiry within Fat Studies. This paper contributes to that literature with a re-reading of obesity discourse via what queer theorist Lee Edelman (2004) has called âreproductive futurismâ. Edelman contends that queerness figures the social order's death drive, and is thus abjected in order to assure the reproduction of that social order. This paper argues that, like the queer, fatness is increasingly being figured as anti-social and as that which must be eliminated in the name of a viable future.
Framing obesity in this way makes possible an analysis of the presumed âthreatâ of obesity, frequently referred to, but seldom unpacked, in the existing literature. A comparative analysis of the UK government's Change 4 Life (2009) public health campaign and nineteenth century theories of degeneracy is used to illustrate the cultural anxieties about immorality, disease, civilization and death that undergird both discourses. This analysis suggests the centrality of rationality and self-control, understood as moral, to the reproduction of the social order.
Furthermore, reading the âobesity epidemicâ as couched in the logic of reproductive futurism opens up potential alternative approaches to fat politics. In the light of Samantha Murray's (2008) critique of the liberal humanist underpinnings of fat activist discourse, this paper considers whether Edelman's advocacy of âfuture-negatingâ for queers, offers a productive trajectory for fat politics
Suppression of Superfluidity of He in a Nanoporous Glass by Preplating a Kr Layer
Helium in nanoporous media has attracted much interest as a model Bose system
with disorder and confinement. Here we have examined how a change in porous
structure by preplating a monolayer of krypton affects the superfluid
properties of He adsorbed or confined in a nanoporous Gelsil glass, which
has a three-dimensional interconnected network of nanopores of 5.8 nm in
diameter. Isotherms of adsorption and desorption of nitrogen show that
monolayer preplating of Kr decreases the effective pore diameter to 4.7 nm and
broadens the pore size distribution by about eight times from the sharp
distribution of the bare Gelsil sample. The superfluid properties were studied
by a torsional oscillator for adsorbed film states and pressurized liquid
states, both before and after the monolayer Kr preplating. In the film states,
both the superfluid transition temperature and the superfluid
density decrease about 10 percent by Kr preplating. The suppression of film
superfluidity is attributed to the quantum localization of He atoms by the
randomness in the substrate potential, which is caused by the
preplating--induced broadening of the pore size distribution. In the
pressurized liquid states, the superfluid density is found
to increase by 10 percent by Kr preplating, whereas is
decreased by 2 percent at all pressures. The unexpected enhancement of
might indicate the existence of an unknown disorder effect
for confined He.Comment: 27 pages, 8 figures, submitted to J. Phys. Soc. Jp
Contemplating an evolutionary approach to entrepreneurship
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
<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
The Past and Future of Evolutionary Economics : Some Reflections Based on New Bibliometric Evidence
This document is the Accepted Manuscript version of the following article: Geoffrey M. Hodgson, and Juha-Antti Lamberg, âThe past and future of evolutionary economics: some reflections based on new bibliometric evidenceâ, Evolutionary and Institutional Economics Review, first online 20 June 2016. The final publication is available at Springer via doi: http://dx.doi.org/10.1007/s40844-016-0044-3 Š Japan Association for Evolutionary Economics 2016The modern wave of âevolutionary economicsâ was launched with the classic study by Richard Nelson and Sidney Winter (1982). This paper reports a broad bibliometric analysis of âevolutionaryâ research in the disciplines of management, business, economics, and sociology over 25 years from 1986 to 2010. It confirms that Nelson and Winter (1982) is an enduring nodal reference point for this broad field. The bibliometric evidence suggests that âevolutionary economicsâ has benefitted from the rise of business schools and other interdisciplinary institutions, which have provided a home for evolutionary terminology, but it has failed to nurture a strong unifying core narrative or theory, which in turn could provide superior answers to important questions. This bibliometric evidence also shows that no strong cluster of general theoretical research immediately around Nelson and Winter (1982) has subsequently emerged. It identifies developmental problems in a partly successful but fragmented field. Future research in âevolutionary economicsâ needs a more integrated research community with shared conceptual narratives and common research questions, to promote conversation and synergy between diverse clusters of research.Peer reviewedFinal Accepted Versio
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