34 research outputs found

    The impact of price and exchange rate policies on agriculture in sub-saharan Africa

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    The purposes of this paper are two. Firstly, a review is undertaken of the available literature on the impact of price and exchange rate policies on agriculture in Sub-Saharan Africa. Secondly, an empirical analysis is undertaken using data for 31 Sub-Saharan African countries to test several of the common hypotheses concerning this policy Impact. The findings tend to confirm the predominate view that in Sub- Saharan Africa, price and exchange rate policy has an impact on agricultural production. With the exception of a few countries, the impact has been negative. However, the analysis suggests that these policies are not the most important factors affecting agricultural growth. Indeed these policies have a relatively small impact compared to other factors such as Government development in farm input supply, population growth, and Government's ability to operate and maintain its agricultural investments. Much of the variation in agricultural growth between African countries still cannot be explained. "Appropriate" price and exchange rate policy would have a relatively small impact on agricultural growth. The literature on this subject tends to suggest a general thrust of policy reform appropriate to all African countries. In this article it is argued that there is no stereotype price policy package suitable for all African countries. The reason is that the depth of the policy problem differs considerably between countries, as do policy objectives and other constraints (land, water, markets, social, political, etc). The policy package to remedy problems caused by poor price and exchange rate policy must therefore be adapted to each country. It should in particular adapt itself to the political situations of various countries. It must emphasize policies in addition to price and exchange rate reform. Donors should help by pushing reform in the right direction, but not expecting rapid achievement of optimal policy. Helping to establish an effective policy making process may be more important than achieving specific price and exchange rate targets

    Finding Z' bosons coupled preferentially to the third family at CERN LEP and the Fermilab Tevatron

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    Z' bosons that couple preferentially to the third generation fermions can arise in models with extended weak (SU(2)xSU(2)) or hypercharge (U(1)xU(1)) gauge groups. We show that existing limits on quark-lepton compositeness set by the LEP and Tevatron experiments translate into lower bounds of order a few hundred GeV on the masses of these Z' bosons. Resonances of this mass can be directly produced at the Tevatron. Accordingly, we explore in detail the limits that can be set at Run II using the process p pbar -> Z' -> tau tau -> e mu. We also comment on the possibility of using hadronically-decaying taus to improve the limits.Comment: LaTeX2e, 24 pages (including title page), 13 figures; version 2: corrected typographical errors and bad figure placement; version 3: added references and updated introduction; version 4: changes to compensate for old latex version on arXiv server; version 5: additional references, and embedded fonts in eps files for PRD; version 6: corrected some minor typos to address PRD referee's comment

    Field-deployable, quantitative, rapid identification of active Ebola virus infection in unprocessed blood

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    The West African Ebola virus outbreak underlined the importance of delivering mass diagnostic capability outside the clinical or primary care setting in effectively containing public health emergencies caused by infectious disease. Yet, to date, there is no solution for reliably deploying at the point of need the gold standard diagnostic method, real time quantitative reverse transcription polymerase chain reaction (RT- qPCR), in a laboratory infrastructure-free manner. In this proof of principle work, we demonstrate direct performance of RT-qPCR on fresh blood using far-red fluorophores to resolve fluorogenic signal inhibition and controlled, rapid freeze/thawing to achieve viral genome extraction in a single reaction chamber assay. The resulting process is entirely free of manual or automated sample pre-processing, requires no microfluidics or magnetic/mechanical sample handling and thus utilizes low cost consumables. This enables a fast, laboratory infrastructure-free, minimal risk and simple standard operating procedure suited to frontline, field use. Developing this novel approach on recombinant bacteriophage and recombinant human immunodeficiency virus (HIV; Lentivirus), we demonstrate clinical utility in symptomatic EBOV patient screening using live, infectious Filoviruses and surrogate patient samples. Moreover, we evidence assay co-linearity independent of viral particle structure that may enable viral load quantification through pre-calibration, with no loss of specificity across an 8 log- linear maximum dynamic range. The resulting quantitative rapid identification (QuRapID) molecular diagnostic platform, openly accessible for assay development, meets the requirements of resource- limited countries and provides a fast response solution for mass public health screening against emerging biosecurity threats

    From Indymedia to Anonymous: rethinking action and identity in digital cultures

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    The period following the social mobilizations of 2011 has seen a renewed focus on the place of communication in collective action, linked to the increasing importance of digital communications. Framed in terms of personalized ‘connective action’ or the social morphology of networks, these analyses have criticized previously dominant models of ‘collective identity’, arguing that collective action needs to be understood as ‘digital networking’. These influential approaches have been significantly constructed as a response to models of communication and action evident in the rise of Independent Media Centres in the period following 1999. After considering the rise of the ‘digital networking’ paradigm linked to analyses of Indymedia, this article considers the emergence of the internet-based collaboration known as Anonymous, focusing on its origins on the 4chan manga site and its 2008 campaign against Scientology, and also considers the ‘I am the 99%’ microblog that emerged as part of the Occupy movement. The emergence of Anonymous highlights dimensions of digital culture such as the ephemeral, the importance of memes, an ethic of lulz, the mask and the grotesque. These forms of communication are discussed in the light of dominant attempts to shape digital space in terms of radical transparency, the knowable and the calculable. It is argued that these contrasting approaches may amount to opposing social models of an emerging information society, and that the analysis of contemporary conflicts and mobilizations needs to be alert to novel forms of communicative practice at work in digital cultures today

    Tracing the Complex History of Manuscripts Using Linked Data

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    Abstract of paper 1094 presented at the Digital Humanities Conference 2019 (DH2019), Utrecht , the Netherlands 9-12 July, 2019

    A Social-Ecological System Framework for Marine Aquaculture Research

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    Aquaculture has been responsible for an impressive growth in the global supply of seafood. As of 2016, more than half of all global seafood production comes from aquaculture. To meet future global seafood demands, there is need and opportunity to expand marine aquaculture production in ways that are both socially and ecologically sustainable. This requires integrating biophysical, social, and engineering sciences. Such interdisciplinary research is difficult due to the complexity and multi-scale aspects of marine aquaculture and inherent challenges researchers face working across disciplines. To this end, we developed a framework based on Elinor Ostrom’s social–ecological system framework (SESF) to guide interdisciplinary research on marine aquaculture. We first present the framework and the social–ecological system variables relevant to research on marine aquaculture and then illustrate one application of this framework to interdisciplinary research underway in Maine, the largest producer of marine aquaculture products in the United States. We use the framework to compare oyster aquaculture in two study regions, with a focus on factors influencing the social and biophysical carrying capacity. We conclude that the flexibility provided by the SESF is well suited to inform interdisciplinary research on marine aquaculture, especially comparative, cross-case analysis
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