369 research outputs found
Understanding disease control: influence of epidemiological and economic factors
We present a local spread model of disease transmission on a regular network
and compare different control options ranging from treating the whole
population to local control in a well-defined neighborhood of an infectious
individual. Comparison is based on a total cost of epidemic, including cost of
palliative treatment of ill individuals and preventive cost aimed at
vaccination or culling of susceptible individuals. Disease is characterized by
pre- symptomatic phase which makes detection and control difficult. Three
general strategies emerge, global preventive treatment, local treatment within
a neighborhood of certain size and only palliative treatment with no
prevention. The choice between the strategies depends on relative costs of
palliative and preventive treatment. The details of the local strategy and in
particular the size of the optimal treatment neighborhood weakly depends on
disease infectivity but strongly depends on other epidemiological factors. The
required extend of prevention is proportional to the size of the infection
neighborhood, but this relationship depends on time till detection and time
till treatment in a non-nonlinear (power) law. In addition, we show that the
optimal size of control neighborhood is highly sensitive to the relative cost,
particularly for inefficient detection and control application. These results
have important consequences for design of prevention strategies aiming at
emerging diseases for which parameters are not known in advance
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On the Management of Population Immunity
This paper considers a susceptible-infected-recovered type model of infectious diseases, such as COVID-19 or swine flu, in which costly treatment or vaccination confers immunity on recovered individuals. Once immune, individuals indirectly protect the re
The deindustrialisation/tertiarisation hypothesis reconsidered: a subsystem application to the OECD7
The diffusion of outsourcing, both national and international, and
vertical FDIs among manufacturing firms, along with the higher integra-
tion of business services in manufacturing, has recently led to question
the empirical evidence supporting the Deindustrialisation/Tertiarisation
(DT) hypothesis. Rather than a \real" phenomenon, it has been argued,
DT would be an \apparent" one, mainly due to the reorganization of
production across national and sectoral boundaries.
The empirical studies that have dealt with the topic so far have
not been able to effectively rule out such possibility, because of two
main limitations: the sectoral level of the analysis and/or the national
focus. In order to overcome them, the paper carries out an appreciative
investigation of the actual extent of the DT occurred in the OECD
area over the '80s and the '90s by moving from a sector to a subsystem
perspective, thus retaining both direct and indirect relations, and by
referring to a \pseudo-World" of 7 OECD countries, thus taking into
account the \global" dimension of the phenomenon.
The results strongly support the DT hypothesis: although the weight
of business sector services in the manufacturing subsystem increased,
acting as a counterbalancing tendency to the manufacturing decline,
subsystem shares significantly decreased, thus confirming DT as a more
fundamental trend of modern economies
Democracy in trade unions, democracy through trade unions?
Since the Webbs published Industrial Democracy at the end of the nineteenth century, the principle that workers have a legitimate voice in decision-making in the world of work – in some versions through trade unions, in others at least formally through separate representative structures – has become widely accepted in most west European countries. There is now a vast literature on the strengths and weaknesses of such mechanisms, and we review briefly some of the key interpretations of the rise (and fall) of policies and structures for workplace and board-level representation. We also discuss the mainly failed attempts to establish broader processes of economic democracy, which the eclipse of nationally specific mechanisms of class compromise makes again a salient demand. Economic globalization also highlights the need for transnational mechanisms to achieve worker voice (or more radically, control) in the dynamics of capital-labour relations. We therefore examine the role of trade unions in coordinating pressure for a countervailing force at European and global levels, and in the construction of (emergent?) supranational industrial relations. However, many would argue that unions cannot win legitimacy as democratizing force unless manifestly democratic internally. We therefore revisit debates on and dilemmas of democracy within trade unions, and examine recent initiatives to enhance democratization
Avaliação sistêmica do setor industrial brasileiro: 1995-2009
Resumo O presente artigo busca avaliar o setor industrial sob uma ótica distinta da que tem sido utilizada quando se trata de industrialização/desindustrialização. O objetivo é analisar o caráter sistêmico do setor industrial a partir do método de insumo-produto, por meio de indicadores de intensidade direta e intensidade direta mais indireta da indústria. Por esta medida, é possível deixar mais clara a contribuição do artigo, ou seja, fornecer uma medida de integração produtiva do setor industrial com os demais setores, de modo a verificar se a indústria tem ganhado importância relativa como setor articulador das atividades produtivas
Balancing Detection and Eradication for Control of Epidemics: Sudden Oak Death in Mixed-Species Stands
Culling of infected individuals is a widely used measure for the control of several plant and animal pathogens but culling first requires detection of often cryptically-infected hosts. In this paper, we address the problem of how to allocate resources between detection and culling when the budget for disease management is limited. The results are generic but we motivate the problem for the control of a botanical epidemic in a natural ecosystem: sudden oak death in mixed evergreen forests in coastal California, in which species composition is generally dominated by a spreader species (bay laurel) and a second host species (coast live oak) that is an epidemiological dead-end in that it does not transmit infection but which is frequently a target for preservation. Using a combination of an epidemiological model for two host species with a common pathogen together with optimal control theory we address the problem of how to balance the allocation of resources for detection and epidemic control in order to preserve both host species in the ecosystem. Contrary to simple expectations our results show that an intermediate level of detection is optimal. Low levels of detection, characteristic of low effort expended on searching and detection of diseased trees, and high detection levels, exemplified by the deployment of large amounts of resources to identify diseased trees, fail to bring the epidemic under control. Importantly, we show that a slight change in the balance between the resources allocated to detection and those allocated to control may lead to drastic inefficiencies in control strategies. The results hold when quarantine is introduced to reduce the ingress of infected material into the region of interest
Environmental regulation induced foreign direct investment
The last decade has witnessed a renewed interest in the relationship between environmental regulations and international capital flows. However, empirical studies have so far failed to find conclusive evidence for this so-called pollution haven or race to the bottom effect where foreign direct investment (FDI) is assumed to be attracted to low regulation countries, regions or states. In this paper we present a simple theoretical framework to demonstrate that greater stringency in environmental standards can lead to a strategic increase in capital inflows which we refer to as environmental regulation induced FDI. Our result reveals a possible explanation for the mixed results in the empirical literature and provides an illustration of the conditions under which environmental regulations in the host country can affect the location decision of foreign firms
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