1,103 research outputs found

    Historical legacies and African development

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    As Africa’s role on the global stage is rising, so does the need to understand the shadow of history on the continent’s economy and polity. We discuss recent works that shed light on Africa’s colonial and precolonial legacies. The emerging corpus is remarkably interdisciplinary. Archives, ethnographic materials, georeferenced censuses, surveys, and satellite imagery are some of the sources often combined to test influential conjectures put forward in African historiography. Exploiting within-country variation and employing credible, albeit mostly local, identification techniques, this recent literature has uncovered strong evidence of historical continuity as well as instances of rupture in the evolution of the African economy. The exposition proceeds in reverse chronological order. Starting from the colonial period, which has been linked to almost all of Africa’s postindependence maladies, we first review works that uncover the lasting legacies of colonial investments in infrastructure and human capital and quantify the role of various extractive institutions, such as indirect rule and oppression associated with concessionary agreements. Second, we discuss the long-lasting impact of the "Scramble for Africa," which led to ethnic partitioning and the creation of artificial modern states. Third, we cover studies on the multifaceted legacy of the slave trades. Fourth, we analyze the contemporary role of various precolonial, ethnic-specific, institutional and social traits, such as political centralization. We conclude by offering some thoughts on what we view as open questions

    Multi-criteria assessment of ethical aspects in fresh tomato systems: Plant genomics technology innovation and food policy uses

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    Product assessment for imperceptible characteristics like environmental impact, healthfulness, naturalness, and fairness is a helpful tool in product innovation and for enhancing socially responsible conduct. In this study we apply multiple criteria analysis for the assessment of fresh tomatoes in terms of consumer perceptions regarding the above characteristics. The generated indices provide an explicit and comprehensive representation of consumer perceptions. Existing tomato products from the Dutch market are ranked alongside (reasonable conjectures of) potential products to be developed with the use of plant genomics technology. The results are interpreted to provide insights into the socially optimal use of (plant genomics) technology for fresh tomato production. Policy uses are highlighted.Ethical assessment, corporate societal responsibility, multiple criteria., Demand and Price Analysis, Research and Development/Tech Change/Emerging Technologies,

    Potential for Liquefaction Due to Construction Blasting

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    A method based on laboratory cyclic triaxial and torsional tests of undisturbed soil samples has been developed to predict the potential for liquefaction due to buried charges, such as those used in construction blasting. The results of a test blasting program conducted at a construction site are presented. The case history yielded data on particle velocities and blast induced porewater pressure changes

    Passive Control of Bridges

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    In the design of bridges with large spans, the significant values of the moments at the main deck-structure require very heavy members, either in the case of a beam or a truss deck-structure. In order to minimize the influence of bending moments, several applications of passive control of displacements using cable nets are herein proposed. The base for all the proposed systems is the cables supported beam nets with additional prestressing control on support cables to optimize the structural behavior of the system. The passive control design problem leads to an optimal control problem for structures governed by variational inequalities. In this presentation several bridge systems are proposed and studied as applications of this method

    Effect on the canine Eck fistula liver of intraportal TGF‐β alone or with hepatic growth factors

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    Transforming growth factor‐β canceled the hepatocyte proliferation caused by transforming growth factor‐α when the two substances were mixed and administered through a disconnected central portal vein branch after creation of an Eck fistula. In contrast, transforming growth factor‐β had no antidotal action on the stimulatory effects of insulin or full test doses of insulinlike factor‐2, hepatocyte growth factor, epidermal growth factor or triiodothymanine. A minor antidotal effect on hepatic stimulatory substance activity could be detected, but only with hepatic stimulatory substance was given in doses smaller than those known to cause maximum stimulatory response. These results suggest a highly specific pharmacological and physiological interaction between transforming growth factor‐α and transforming growth factor‐α in the modulation of liver growth control. (HEPATOLOGY 1992;16:1267–1270.) Copyright © 1992 American Association for the Study of Liver Disease

    Worldwide research productivity in critical care medicine

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    INTRODUCTION: The number of publications and the impact factor of journals are accepted estimates of the quantity and quality of research productivity. The objective of the present study was to assess the worldwide scientific contribution in the field of critical care medicine. METHOD: All research studies published between 1995 and 2003 in medical journals that were listed in the 2003 Science Citation Index (SCI(®)) of Journal Citation Reports under the subheading 'critical care' and also indexed in the PubMed database were reviewed in order to identify their geographical origin. RESULTS: Of 22,976 critical care publications in 14 medical journals, 17,630 originated from Western Europe and the USA (76.7%). A significant increase in the number of publications originated from Western European countries during the last 5 years of the study period was noticed. Scientific publications in critical care medicine increased significantly (25%) from 1995 to 2003, which was accompanied by an increase in the impact factor of the corresponding journals (47.4%). Canada and Japan had the better performance, based on the impact factor of journals. CONCLUSION: Significant scientific progress in critical care research took place during the period of study (1995–2003). Leaders of research productivity (in terms of absolute numbers) were Western Europe and the USA. Publications originating from Western European countries increased significantly in quantity and quality over the study period. Articles originating from Canada, Japan, and the USA had the highest mean impact factor.. Canada was the leader in productivity when adjustments for gross domestic product and population were made

    Impact of Definitive Therapy with Beta-Lactam Monotherapy or Combination with an Aminoglycoside or a Quinolone for Pseudomonas aeruginosa Bacteremia

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    BACKGROUND: Bacteremia by Pseudomonas aeruginosa represents one severe infection. It is not clear whether beta-lactam monotherapy leads to similar rates of treatment success compared to combinations of beta-lactams with aminoglycosides or quinolones. METHODS: Retrospective cohort study from 3 tertiary hospitals (2 in Greece and 1 in Italy). Pseudomonas aeruginosa isolates were susceptible to a beta-lactam and an aminoglycoside or a quinolone. Patients received appropriate therapy for at least 48 hours. Primary outcome of interest was treatment success in patients with definitive beta-lactam combination therapy compared to monotherapy. Secondary outcomes were treatment success keeping the same empirical and definitive regimen, mortality, and toxicity. RESULTS: Out of 92 bacteremias there were 54 evaluable episodes for the primary outcome (20 received monotherapy). Treatment success was higher with combination therapy (85%) compared to beta-lactam monotherapy (65%), however not statistically significantly [Odds ratio (OR) 3.1; 95% Confidence Interval (CI) 0.69-14.7, p = 0.1]. Very long (>2 months) hospitalisation before bacteremia was the only factor independently associated with treatment success (OR 0.73; 95% CI 0.01-0.95, p = 0.046), however this result entailed few episodes. All-cause mortality did not differ significantly between combination therapy [6/31 (19%)] and monotherapy [8/19 (42%)], p = 0.11. Only Charlson comorbidity index was associated with excess mortality (p = 0.03). CONCLUSION: Our study, in accordance with previous ones, indicates that the choice between monotherapy and combination therapy may not affect treatment success significantly. However, our study does not have statistical power to identify small or moderate differences. A large randomized controlled trial evaluating this issue is justified

    Aerosolized colistin as adjunctive treatment of ventilator-associated pneumonia due to multidrug-resistant Gram-negative bacteria: A prospective study

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    SummaryBackgroundVentilator-associated pneumonia (VAP) remains the leading cause of death in patients with intensive care unit (ICU) acquired infections associated with an attributable mortality around 30%. Increasing antimicrobial resistance in patients with VAP challenges intensivists to search for alternative therapeutic options. There is scarcity of data in the literature concerning the administration of aerosolized colistin in critically ill patients with VAP due to multidrug-resistant (MDR) Gram-negative pathogens.MethodsTo assess the safety and effectiveness of aerosolized colistin as an adjunctive to the intravenous antimicrobial therapy for the treatment of VAP due to MDR Gram-negative pathogens, we prospectively examined all patients, who received inhaled colistin.ResultsSixty critically ill patients with a mean APACHE II score 16.7, received aerosolized colistin for the treatment of VAP due to MDR pathogens [Acinetobacter baumannii (37/60 cases), Pseudomonas aeruginosa (12/60 cases) and Klebsiella pneumoniae strains (11/60 cases)]. Half of the isolated pathogens were susceptible only to colistin. Mean (±SD) daily dosage of aerosolized colistin was 2.2 (±0.7) million international units (IU). All patients received 2946 inhalations of colistin and the mean duration of administration was 16.4 days. Fifty-seven patients received concomitant intravenous treatment with colistin or other antimicrobial agents. Bacteriological and clinical response of VAP was observed in 50/60 (83.3%) patients. No adverse effects related to inhaled colistin were recorded. All cause hospital mortality was 25% while mortality attributable to VAP was 16.7%.ConclusionsAerosolized colistin may be considered as adjunctive to intravenous treatment in patients with VAP due to MDR Gram-negative bacteria susceptible to colistin in critically ill patients. Although colistin is safe and effective, the best route of administration remains unclear. In addition, controlled comparative studies are needed to establish its effectiveness and safety
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