In vitro activity of antimalarials against clinical isolates of Plasmodium falciparum in Yaounde, Cameroon

The in vitro activity of nine antimalarials was determined against 119 fresh clinical isolates of #Plasmodium falciparum$ obtained from symptomatic indigenous patients in Yaounde, Cameroun, using the isotopic semimicrotest. Seventy-four parasites were resistant to chloroquine (mean 50% inhibitory concentration [IC50] 337 nM) ; 45 were chloroquine-sensitive (mean IC50 35.6 nM). Twenty-five of 58 chloroquine-resistant parasites were resistant to monodesethylamodiaquine, the biologically active metabolite of amodiaquine. None of the chloroquine-sensitive isolates was resistant to monodesethylamodiaquine (IC50 17.3 nM). Pyronaridine, quinine, mefloquine, halofantrine, and artemether were highly active against the chloroquine-sensitive and the chloroquine-resistant isolates. Of the 43 isolates tested, 25 were sensitive to both pyrimethamine and cycloguanil, the biologically active metabolite of proguanil. The in vitro responses of chloroquine and monodesethylamodiaquine, chloroquine and quinine, quinine and mefloquine, mefloquine and halofantrine, artemether and mefloquine or halofantrine, and pyrimethamine and cycloguanil were significantly correlated. The present study suggests that chloroquine resistance is highly prevalent in vitro in Yaounde and that the alternative drugs are generally highly active against the chloroquine-resistant parasites. (Résumé d'auteur

Why and when do family firms invest less in talent management? The suppressor effect of risk aversion

none4siThis article explores the complex relationship between family firms and talent management practices. We use an international sample of medium-sized manufacturing firms to show that the relationship between family-owned firms and investment in talent management practices is mediated by the firm’s level of risk aversion, which is, in turn, moderated by industry competition. Risk-averse family-owned firms tend to invest less in talent management practices when industry competition is weak. In contrast, when competition increases, family-owned firms tend to invest in talent as much as non-family-owned firms do.openBasco, Rodrigo; Bassetti, Thomas; Dal Maso, Lorenzo; Lattanzi, NicolaBasco, Rodrigo; Bassetti, Thomas; Dal Maso, Lorenzo; Lattanzi, Nicol

Rozvoj osobnosti studenta na vysoké škole – francouzský model

Šance studentů uspět na vysoké škole jsou ovlivněny četnými faktory. Kulturní a socioekonomické rozdíly mezi jednotlivými studenty jsou značné. Je proto nutné vytvořit podmínky, které jim umožní osvojit si schopnosti nezbytné k úspěchu při studiu. V kontextu francouzské pedagogické reality zde nabízíme jednu z možností, jak pedagogicky podpořit rozvoj osobnosti studenta. Zkušenosti z Francie by mohly být přínosné i pro Českou republiku, která je nyní sice v jiné situaci, avšak směřuje k podobným změnám ve vysokoškolském vzdělávání, kterými v minulosti prošla Francie, tj. k rozšířenému přístupu k vysokoškolskému vzdělávání a k jeho opravdové demokratizaci, tedy i k nárůstu počtu vysokoškolských studentů

Fuel Cell Testing Protocols: An International Perspective

An overview of international polymer-electrolyte fuel cell (PEMFC) test procedures is presented. This overview is the first step in the global harmonization of testing methods. Many techniques and procedures determining stack performance and durability are discussed. Each approach has differences that may or may not impact the data and data quality. Through experiments, it was found that differences in the results from two methods for measuring sequential polarization curves are minimal. Answers to questions regarding differences in the aging duty cycles need to be determined experimentally. The results of these experiments are expected to help the harmonization process, to facilitate the understanding of test results, and, possibly, to accelerate the commercialization of PEMFCs.JRC.F.2-Cleaner energ

General Statistical properties of the CMB Polarization field

The distribution of the polarization of the Cosmic Microwave Background (CMB) in the sky is determined by the hypothesis of random Gaussian distribution of the primordial density perturbations. This hypotheses is well motivated by the inflationary cosmology. Therefore, the test of consistency of the statistical properties of the CMB polarization field with the Gaussianity of primordial density fluctuations is a realistic way to study the nature of primordial inhomogeneities in the Universe. This paper contains the theoretical predictions of the general statistical properties of the CMB polarization field. All results obtained under assumption of the Gaussian nature of the signal. We pay the special attention to the following two problems. First, the classification and statistics of the singular points of the polarization field where polarization is equal to zero. Second, the topology of contours of the value of the degree of polarization. We have investigated the percolation properties for the zones of ``strong'' and ``weak'' polarization. We also have calculated Minkowski functionals for the CMB polarization field. All results are analytical.Comment: Latex, 22 pages, including 5 figure

Testing of pyrochemical centrifugal contactors

A centrifugal contactor that performs oxidation and reduction exchange reactions between molten metals and salts at 500 degrees Centigrade has been tested successfully at Argonne National Laboratory (ANL). The design is based on contactors for aqueous- organic systems operation near room temperature. In tests to demonstrate the performance of the pyrocontactor, cadmium and LICl- KCl eutectic salt were the immiscible solvent phases, and rare earths were the distributing solutes. The tests showed that the pyrocontactor mixed and separated the phases well, with stage efficiencies approaching 99% at rotor speeds near 2700 rpm. The contactor ran smoothly and reliably over the entire range of speeds that was tested

Paludisme grave à Aïoun: étude rétrospective à propos de 64 cas

En Mauritanie, comme dans de nombreux pays africains, le paludisme reste la première cause d’hospitalisation en pratique pédiatrique courante. Objectif : Analyser les aspects épidémiologiques, cliniques, évolutifs et les facteurs de mauvais pronostic liés au paludisme grave des enfants hospitalisés dans le service de pédiatrie du centre hospitalier régional d’Aïoun. Patients et méthodes : Il s’agissait d’une étude rétrospective portant sur les dossiers des enfants hospitalisés dans le service de pédiatrie du centre hospitalier régional d’Aïoun du 1er janvier au 31 décembre 2013. Résultats : Au total, 64 enfants étaient hospitalisés pour un paludisme grave (46,3%). Le sex ratio était de 2,07 en faveur des garçons. La tranche d’âge 6 mois – 5 ans était la plus touchée (60,9%). L’automédication était retrouvée dans 29,7% des cas. Les formes neurologiques (60,9%) et les formes anémiques (42,2%) représentaient les premières manifestations cliniques. La létalité globale était de 12,5%. Les facteurs de mauvais pronostic étaient : l’âge, inférieur à cinq ans et l’existence de crises convulsives, d’un coma, d’un syndrome de détresse respiratoire ou de la prostration. Conclusion : L’amélioration du pronostic du paludisme grave repose sur une amélioration d’équipement de salle de réanimation, mais aussi sur un diagnostic et une prise en charge thérapeutique précoces et adéquates

World Antimalarial Resistance Network (WARN) II: In vitro antimalarial drug susceptibility

Intrinsic resistance of Plasmodium falciparum is clearly a major determinant of the clinical failure of antimalarial drugs. However, complex interactions between the host, the parasite and the drug obscure the ability to define parasite drug resistance in vivo. The in vitro antimalarial drug susceptibility assay determines ex-vivo growth of parasite in the presence of serial drug concentrations and, thus, eliminates host effects, such as drug metabolism and immunity. Although the sensitivity of the parasite to various antimalarials provided by such a test provides an important indicator of intrinsic parasite susceptibility, there are fundamental methodological issues that undermine comparison of in vitro susceptibility both between laboratories and within a single laboratory over time. A network of laboratories is proposed that will agree on the basic parameters of the in vitro test and associated measures of quality control. The aim of the network would be to establish baseline values of sensitivity to commonly used antimalarial agents from key regions of the world, and create a global database, linked to clinical, molecular and pharmacology databases, to support active surveillance to monitor temporal trends in parasite susceptibility. Such a network would facilitate the rapid detection of strains with novel antimalarial resistance profiles and investigate suitable alternative treatments with retained efficacy