Comparing Etest and Broth Microdilution for Antifungal Susceptibility Testing of the Most-Relevant Pathogenic Molds.

Invasive mold infections are life-threatening diseases for which appropriate antifungal therapy is crucial. Their epidemiology is evolving, with the emergence of triazole-resistant Aspergillus spp. and multidrug-resistant non-Aspergillus molds. Despite the lack of interpretive criteria, antifungal susceptibility testing of molds may be useful in guiding antifungal therapy. The standard broth microdilution method (BMD) is demanding and requires expertise. We assessed the performance of a commercialized gradient diffusion method (Etest method) as an alternative to BMD. The MICs or minimal effective concentrations (MECs) of amphotericin B, voriconazole, posaconazole, caspofungin, and micafungin were assessed for 290 clinical isolates of the most representative pathogenic molds (154 Aspergillus and 136 non-Aspergillus isolates) with the BMD and Etest methods. Essential agreements (EAs) within ±2 dilutions of ≥90% between the two methods were considered acceptable. EAs for amphotericin B and voriconazole were >90% for most potentially susceptible species. For posaconazole, the correlation was acceptable for Mucoromycotina but Etest MIC values were consistently lower for Aspergillus spp. (EAs of <90%). Excellent EAs were found for echinocandins with highly susceptible (MECs of <0.015 μg/ml) or intrinsically resistant (MECs of >16 μg/ml) strains. However, MEC determinations lacked consistency between methods for strains exhibiting mid-range MECs for echinocandins. We concluded that the Etest method is an appropriate alternative to BMD for antifungal susceptibility testing of molds under specific circumstances, including testing with amphotericin B or triazoles for non-Aspergillus molds (Mucoromycotina and Fusarium spp.). Additional study of molecularly characterized triazole-resistant Aspergillus isolates is required to confirm the ability of the Etest method to detect voriconazole and posaconazole resistance among Aspergillus spp.

Local effects drive heterozygosity-fitness correlations in an outcrossing long-lived tree.

Heterozygosity-fitness correlations (HFCs) have been used to understand the complex interactions between inbreeding, genetic diversity and evolution. Although frequently reported for decades, evidence for HFCs was often based on underpowered studies or inappropriate methods, and hence their underlying mechanisms are still under debate. Here, we used 6100 genome-wide single nucleotide polymorphisms (SNPs) to test for general and local effect HFCs in maritime pine (Pinus pinaster Ait.), an iconic Mediterranean forest tree. Survival was used as a fitness proxy, and HFCs were assessed at a four-site common garden under contrasting environmental conditions (total of 16 288 trees). We found no significant correlations between genome-wide heterozygosity and fitness at any location, despite variation in inbreeding explaining a substantial proportion of the total variance for survival. However, four SNPs (including two non-synonymous mutations) were involved in significant associations with survival, in particular in the common gardens with higher environmental stress, as shown by a novel heterozygosity-fitness association test at the species-wide level. Fitness effects of SNPs involved in significant HFCs were stable across maritime pine gene pools naturally growing in distinct environments. These results led us to dismiss the general effect hypothesis and suggested a significant role of heterozygosity in specific candidate genes for increasing fitness in maritime pine. Our study highlights the importance of considering the species evolutionary and demographic history and different spatial scales and testing environments when assessing and interpreting HFCs.

Emergent patterns of social organization in captive Cercocebus torquatus: Testing the GrooFiWorld agent-based model

We empirically applied the GrooFiWorld agent-based model (Puga-González et al. 2009) in a group of captive mangabeys (Cercocebus torquatus). We analysed several measurements related to aggression and affiliative patterns. The group adopted a combination of despotic and egalitarian behaviours resulting from the behavioural flexibility observed in the Cercopithecinae subfamily. Our study also demonstrates that the GrooFiWorld agent-based model can be extended to other members of the Cercopithecinae subfamily generating parsimonious hypotheses related to the social organization.

A new alternative method for testing skin irritation using a fresh human skin model

La dermatite irritative est décrite comme une réaction réversible, non immunologique caractérisée par des lésions d'aspect très variable, allant de la simple rougeur jusqu'à la formation de bulles voire d'une nécrose, accompagnée de prurit ou d'une sensation de brûlure suite à I' application d'une substance chimique. Le teste de prédiction d'irritation cutanée est traditionnellement depuis les années 1940 le Test de Draize. Ce test consiste en l'application d'une substance chimique sur une peau rasée de lapin pendant 4h et de regarder à 24h si des signes cliniques d'irritations sont présents. Cette méthode critiquable autant d'un point de vue éthique que qualitative reste actuellement le teste le plus utilisé. Depuis le début des années 2000 de nouvelles méthodes in vitro se sont développées tel que le model d'épiderme humain recombiné (RHE). Il s agit d'une multicouche de kératinocyte bien différencié obtenu depuis une culture de don d'ovocyte. Cependant cette méthode en plus d'être très couteuse n'obtient au mieux que 76% de résultat similaire comparé au test in vivo humain. Il existe donc la nécessité de développer une nouvelle méthode in vitro qui simulerait encore mieux la réalité anatomique et physiologique retrouvée in vivo. Notre objectif a été de développer cette nouvelle méthode in vitro. Pour cela nous avons travaillé avec de la peau humaine directement prélevée après une abdominoplastie. Celle ci après préparation avec un dermatome, un couteau dont la lame est réglable pour découper l'épaisseur souhaitée de peau, est montée dans un système de diffusion cellulaire. La couche cornée est alors exposée de manière optimale à 1 ml de la substance chimique testée pendant 4h. L'échantillon de peau est alors fixé dans du formaldéhyde pour permettre la préparation de lames standards d'hématoxyline et éosine. L'irritation est alors investiguée selon des critères histopathologiques de spongioses, de nécroses et de vacuolisations cellulaires. Les résultats de ce.tte première batterie de testes sont plus que prometteurs. En effet, comparé au résultat in vivo, nous obtenons 100% de concordance pour les 4 même substances testes irritantes ou non irritantes, ce qui est supérieur au model d épiderme humain recombiné (76%). De plus le coefficient de variation entre les 3 différentes séries est inférieur à 0.1 ce qui montre une bonne reproductibilité dans un même laboratoire. Dans le futur cette méthode va devoir être testée avec un plus grand nombre de substances chimiques et sa reproductibilité évaluée dans différents laboratoires. Mais cette première evaluation, très encourageante, ouvre des pistes précieuses pour l'avenir des tests irritatifs.

Preparation of a blood culture pellet for rapid bacterial identification and antibiotic susceptibility testing.

Bloodstream infections and sepsis are a major cause of morbidity and mortality. The successful outcome of patients suffering from bacteremia depends on a rapid identification of the infectious agent to guide optimal antibiotic treatment. The analysis of Gram stains from positive blood culture can be rapidly conducted and already significantly impact the antibiotic regimen. However, the accurate identification of the infectious agent is still required to establish the optimal targeted treatment. We present here a simple and fast bacterial pellet preparation from a positive blood culture that can be used as a sample for several essential downstream applications such as identification by MALDI-TOF MS, antibiotic susceptibility testing (AST) by disc diffusion assay or automated AST systems and by automated PCR-based diagnostic testing. The performance of these different identification and AST systems applied directly on the blood culture bacterial pellets is very similar to the performance normally obtained from isolated colonies grown on agar plates. Compared to conventional approaches, the rapid acquisition of a bacterial pellet significantly reduces the time to report both identification and AST. Thus, following blood culture positivity, identification by MALDI-TOF can be reported within less than 1 hr whereas results of AST by automated AST systems or disc diffusion assays within 8 to 18 hr, respectively. Similarly, the results of a rapid PCR-based assay can be communicated to the clinicians less than 2 hr following the report of a bacteremia. Together, these results demonstrate that the rapid preparation of a blood culture bacterial pellet has a significant impact on the identification and AST turnaround time and thus on the successful outcome of patients suffering from bloodstream infections.

Student Journalism 2.0 : Testing Models for Participatory Learning in the Digital Age

Many educators and educational institutions have yet to integrate web-based practices into their classrooms and curricula. As a result, it can be difficult to prototype and evaluate approaches to transforming classrooms from static endpoints to dynamic, content-creating nodes in the online information ecosystem. But many scholastic journalism programs have already embraced the capabilities of the Internet for virtual collaboration, dissemination, and reader participation. Because of this, scholastic journalism can act as a test-bed for integrating web-based sharing and collaboration practices into classrooms. Student Journalism 2.0 was a research project to integrate open copyright licenses into two scholastic journalism programs, to document outcomes, and to identify recommendations and remaining challenges for similar integrations. Video and audio recordings of two participating high school journalism programs informed the research. In describing the steps of our integration process, we note some important legal, technical, and social challenges. Legal worries such as uncertainty over copyright ownership could lead districts and administrators to disallow open licensing of student work. Publication platforms among journalism classrooms are far from standardized, making any integration of new technologies and practices difficult to achieve at scale. And teachers and students face challenges re-conceptualizing the role their class work can play online.

Re-visiting the health care luxury good hypothesis: Aggregation, precision, and publication biases?

[cat] Mentre que una creixent literatura que ha examinat la relació entre la renda i la despesa sanitària suggereix que els serveis sanitaris són un be de luxe (elasticitat renda superior a la unitat), aquesta conclusió es contínuament debatuda atesa l'heterogeneïtat dels resultats. Aquest article testa la hipòtesis dels serveis sanitaris com bens de luxe fent server anàlisi de meta- regressió, particularment analitzant l'existència de biaixos de selecció de publicació, precisió així com biaixos d'agregació. Els resultats apunten l'existència d'un biaix de publicació, robust independentment dels controls analitzats. Els biaixos de precisió i agregació semblen tenir un paper en la generació de les estimacions de l'elasticitat renda. Els nostres resultat suggereixen que l'elasticitat renda dels serveis sanitaris un cop corregir pels biaixos esmentat varien entre 0.26 i 0.84, però no podem rebutjar que la elasticitat renda es igual a la unitat en algunes estimacions de l'elasticitat corregides.

Re-visiting the health care luxury good hypothesis: Aggregation, precision, and publication biases?

[cat] Mentre que una creixent literatura que ha examinat la relació entre la renda i la despesa sanitària suggereix que els serveis sanitaris són un be de luxe (elasticitat renda superior a la unitat), aquesta conclusió es contínuament debatuda atesa l'heterogeneïtat dels resultats. Aquest article testa la hipòtesis dels serveis sanitaris com bens de luxe fent server anàlisi de meta- regressió, particularment analitzant l'existència de biaixos de selecció de publicació, precisió així com biaixos d'agregació. Els resultats apunten l'existència d'un biaix de publicació, robust independentment dels controls analitzats. Els biaixos de precisió i agregació semblen tenir un paper en la generació de les estimacions de l'elasticitat renda. Els nostres resultat suggereixen que l'elasticitat renda dels serveis sanitaris un cop corregir pels biaixos esmentat varien entre 0.26 i 0.84, però no podem rebutjar que la elasticitat renda es igual a la unitat en algunes estimacions de l'elasticitat corregides.

Food Safety Testing: Rapid Molecular Methods for Chemical and Biological Hazards

The central goal of food safety policy in the European Union (EU) is to protect consumer health by guaranteeing a high level of food safety throughout the food chain. This goal can in part be achieved by testing foodstuffs for the presence of various chemical and biological hazards. The aim of this study was to facilitate food safety testing by providing rapid and user-friendly methods for the detection of particular food-related hazards. Heterogeneous competitive time-resolved fluoroimmunoassays were developed for the detection of selected veterinary residues, that is coccidiostat residues, in eggs and chicken liver. After a simplified sample preparation procedure, the immunoassays were performed either in manual format with dissociation-enhanced measurement or in automated format with pre-dried assay reagents and surface measurement. Although the assays were primarily designed for screening purposes providing only qualitative results, they could also be used in a quantitative mode. All the developed assays had good performance characteristics enabling reliable screening of samples at concentration levels required by the authorities. A novel polymerase chain reaction (PCR)-based assay system was developed for the detection of Salmonella spp. in food. The sample preparation included a short non-selective pre-enrichment step, after which the target cells were collected with immunomagnetic beads and applied to PCR reaction vessels containing all the reagents required for the assay in dry form. The homogeneous PCR assay was performed with a novel instrument platform, GenomEra^™, and the qualitative assay results were automatically interpreted based on end-point time-resolved fluorescence measurements and cut-off values. The assay was validated using various food matrices spiked with sub-lethally injured Salmonella cells at levels of 1-10 colony forming units (CFU)/25 g of food. The main advantage of the system was the exceptionally short time to result; the entire process starting from the pre-enrichment and ending with the PCR result could be completed in eight hours. In conclusion, molecular methods using state-of-the-art assay techniques were developed for food safety testing. The combination of time-resolved fluorescence detection and ready-to-use reagents enabled sensitive assays easily amenable to automation. Consequently, together with the simplified sample preparation, these methods could prove to be applicable in routine testing.

Testing the FTPL across government tiers

Control on regional government budgets is important in a monetary union as lower tiers of government have fewer incentives to consolidate debt. According to the Fiscal Theory of the Price Level; unsustainable non-Ricardian fiscal policies eventually force monetary policy to adjust. Hence, uncoordinated and non-regulated regional fiscal policies would therefore threaten price stability for the monetary union as a whole. However, the union central bank is not without defense. A federal government that internalises the spillover effect of non-Ricardian fiscal policies on the price level can offset non-Ricardian regional fiscal policies. A federal government, which taxes and transfers resources between regions, may compensate for unsustainable regional fiscal policies so as to keep fiscal policy Ricardian on aggregate. Following Canzoneri et al. (2001), we test the validity of the Fiscal Theory of the Price Level for both federal and regional governments in Germany. We find evidence of a spillover effect of unsustainable policies on the price level for other Länder. However, the German federal government offsets this effect on the price level by running Ricardian policies. These results have implications for the regulation of fiscal policies in the EMU.

Determining risk potential through accidents and near-accidents: an empirical study in a steel factory

Fatal and permanently disabling accidents form only one per I cent of all occupational accidents but in many branches of industry they account for more than half the accident costs. Furthermore the human suffering of the victim and his family is greater in severe accidents than in slight ones. For both human and economic reasons the severe accident risks should be identified befor injuries occur. It is for this purpose that different safety analysis methods have been developed . This study shows two new possible approaches to the problem.. The first is the hypothesis that it is possible to estimate the potential severity of accidents independent of the actual severity. The second is the hypothesis that when workers are also asked to report near accidents, they are particularly prone to report potentially severe near accidents on the basis of their own subjective risk assessment. A field study was carried out in a steel factory. The results supported both the hypotheses. The reliability and the validity of post incident estimates of an accident's potential severity were reasonable. About 10 % of accidents were estimated to be potentially critical; they could have led to death or very severe permanent disability. Reported near accidents were significantly more severe, about 60 $ of them were estimated to be critical. Furthermore the validity of workers subjective risk assessment, manifested in the near accident reports, proved to be reasonable. The studied new methods require further development and testing. They could be used both in routine usage in work places and in research for identifying and setting the priorities of accident risks.

Web Application Performance Testing

Web application performance testing is an emerging and important field of software engineering. As web applications become more commonplace and complex, the need for performance testing will only increase. This paper discusses common concepts, practices and tools that lie at the heart of web application performance testing. A pragmatic, hands-on approach is assumed where applicable; real-life examples of test tooling, execution and analysis are presented right next to the underpinning theory. At the client-side, web application performance is primarily driven by the amount of data transmitted over the wire. At the server-side, selection of programming language and platform, implementation complexity and configuration are the primary contributors to web application performance. Web application performance testing is an activity that requires delicate coordination between project stakeholders, developers, system administrators and testers in order to produce reliable and useful results. Proper test definition, execution, reporting and repeatable test results are of utmost importance. Open-source performance analysis tools such as Apache JMeter, Firebug and YSlow can be used to realise effective web application performance tests. A sample case study using these tools is presented in this paper. The sample application was found to perform poorly even under the moderate load incurred by the sample tests.