23 resultados para fresh-frozen


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The aim of this study was to develop a simple, field-practical, and effective in vitro method for determining the sensitivity of fresh erythrocytic Plasmodium vivax isolates to a range of antimalarials. The method used is a modification of the standard World Health Organization (WHO) microtest for determination of P.falciparum drug sensitivity. The WHO method was modified by removing leukocytes and using a growth medium supplemented with AB(+) serum. We successfully carried out 34 in vitro drug assays on 39 P. vivax isolates collected from the Mae Sod malaria clinic, Tak Province, Thailand. The mean percentage of parasites maturing to schizonts (six or more merozoites) in control wells was 66.5% +/- 5.9% (standard deviation). This level of growth in the control wells enabled rapid microscopic determination (5 min per isolate per drug) of the MICs of chloroquine, dihydroartemisinin, WR238605 (tafenoquine), and sulfadoxine. P. vivax was relatively sensitive to chloroquine (MIC = 160 ng/ml, 50% inhibitory concentration [IC50] = 49.8 ng/ml) and dihydroartemisinin (MIC = 0.5 ng/ml, IC50 = 0.47 ng/ml). The poor response of P. vivax to both tafenoquine (MIC = 14,000 ng/ml, IC50 = 9,739 ng/ml) and sulfadoxine (MIC = 500,000 ng/ml, IC50 = 249,000 ng/ml) was due to the slow action of these drugs and the innate resistance of P. vivax to sulfadoxine. The in vitro assay developed in our study should be useful both for assessing the antimalarial sensitivity of P. vivax populations and for screening new antimalarials in the absence of long-term P. vivax cultures.

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The role of several theoretical factors in determining the demand of US banks for borrowed reserves from the Fed is empirically investigated. The main objective is to isolate the candidate(s) most likely responsible for the recent observed phenomenon of banks reluctance to borrow from the Fed, particularly since the mid-1980s. The results indicate that the declining number of banks due to mergers and consolidations holds much of the weight for explaining the weakened demand for borrowed reserves since the mid-1980s. Consistent evidence is found suggesting that US banks may have been unlawfully exploiting the discount window service for profit-taking purposes. This finding proves credible and suggests the need for further loan scrutiny at the Federal discount window.

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As part of a 4-year project to study phenolic compounds in tea shoots over the growing seasons and during black tea processing in Australia, an HPLC method was developed and optimised for the identification and quantification of phenolic compounds, mainly flavanols and phenolic acids, in fresh tea shoots. Methanol proved to be the most suitable solvent for extracting the phenolic compounds, compared with chloroform, ethyl acetate and water. Immediate analysis, by HPLC, of the methanol extract showed higher separation efficiency than analyses after being dried and redissolved. This method exhibited good repeatability (CV 3-9%) and recovery rate (88-116%). Epigallocatechin gallate alone constituted up to 115 mg/g, on a dry basis, in the single sample of Australian fresh tea shoots examined. Four catechins (catechin, gallocatechin, epicatechin and epigallocatechin) and six catechin gallates (epigallocatechin gallate, catechin gallate, epicatechin gallate, gallocatechin gallate, epicatechin digallate and epigallocatechin digallate) have been identified and quantified by this HPLC method. In addition, two major tea alkaloids, caffeine and theobromine, have been quantified, while five flavonol glycosides and six phenolic acids, including quinic acids and esters, were identified and quantified. (C) 2003 Elsevier Ltd. All rights reserved.

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Understanding the particularly low intake of fruits and vegetables among socioeconomically disadvantaged groups is an important issue for public health. This study investigated whether access to retail outlets is similar across areas of varying socioeconomic disadvantage in an Australian urban setting, in terms of distance, the numbers of local shops, and their opening hours. This ecological cross-sectional study used 50 randomly sampled census collection districts and their nearby shopping environment (i.e. within 2.5 km), and generally found minimal or no socioeconomic differences in shopping infrastructure. Important methodological and social/economic issues may explain this contrast with overseas findings.

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Former colonies and dependencies in the South Pacific do not have the luxury of entirely ‘homegrown’ laws. Their legal systems are burdened with a ‘legacy’ of transplanted laws, developed for use in a foreign country, imposed on pre-existing systems of custom and culture. As a result, many small island countries are struggling to balance the demands of law from different sources, designed to operate in fundamentally different circumstances. In addition to the conflict that occurs in areas of substantive law, where customary and introduced law may prescribe a different rule for the same situation, the two systems differ in their approach to procedure, penalties and relief. This paper considers the divide between the theory and practice of introduced law and customary law and examines the way in which conflicts have been dealt with by the courts. In particular, it uses the example of banishment to illustrate the type of problems that arise in a plural system. The paper looks at the balancing exercise which has been necessary when custom, in the form of banishment, comes into conflict with introduced law, in the form of constitutional rights.

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Around the world, consumers and retailers of fresh produce are becoming more and more discerning about factors such as food safety and traceability, health, convenience and the sustainability of production systems, and in doing so they are changing the way in which fresh produce supply chains are configured and managed. When consumers demand fresh, safe, convenient, value-for-money produce, retailers in an increasingly competitive environment are attracted to those business models most capable of meeting these demands profitably. Traditional models are proving less and less able to deliver competitive advantage in such an environment. As a result, opportunistic, adversarial, price-based approaches to doing business between chain members are being replaced by approaches that are more strategic, collaborative and value-based. The shaping force behind this change is the need for producers, wholesalers, category managers, retailers and consumers to have more certainty about the performance of the supply chains upon which they rely. Certainty is generated through the supply chain's ability to create, deliver and share value. How to build supply chains that create, deliver and share value is arguably the single biggest challenge to the competitiveness of fresh produce firms, and therefore to the industries to which they belong.

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