Large-Eddy Simulation and experimental study of cycle-to-cycle variations of stable and unstable operating points in a spark ignition engine

This article presents a comparison between experiments and Large-Eddy Simulation (LES) of a spark ignition engine on two operating points: a stable one characterized by low cycle-to-cycle variations (CCV) and an unstable one with high CCV. In order to match the experimental cycle sample, 75 full cycles (with combustion) are computed by LES. LES results are compared with experiments by means of pressure signals in the intake and exhaust ducts, in-cylinder pressure, chemiluminescence and OH Planar Laser Induced Fluorescence (PLIF). Results show that LES is able to: (1) reproduce the flame behavior in both cases (low and high CCV) in terms of position, shape and timing; (2) distinguish a stable point from an unstable one; (3) predict quantitatively the CCV levels of the two fired operating points. For the unstable case, part of the observed CCV is due to incomplete combustion. The results are then used to analyze the incomplete combustion phenomenon which occurs for some cycles of the unstable point and propose modification of the spark location to control CCV

Shared Learning in an Interconnected World: Innovations to Advance Global Health Equity

The notion of reverse innovation --that some insights from low-income countries might offer transferable lessons for wealthier contexts--is increasingly common in the global health and business strategy literature. Yet the perspectives of researchers and policymakers in settings where these innovations are developed have been largely absent from the discussion to date. In this Commentary, we present examples of programmatic, technological, and research-based innovations from Rwanda, and offer reflections on how the global health community might leverage innovative partnerships for shared learning and improved health outcomes in all countries

Bone events and evolution of biologic markers in Gaucher disease before and during treatment

25 pagesInternational audienceINTRODUCTION : Known biomarkers of Gaucher-disease activity are platelets, chitotriosidase, angiotensin-converting enzyme (ACE), tartrate-resistant acid phosphatase (TRAP) and ferritin. The aim of this study was to retrospectively evaluate the frequency of bone events (BE) and biomarker changes during two periods: diagnosis to first enzyme-replacement therapy (ERT) and the latter to the closing date. METHODS : BE of 62 treated patients, among the 73-patient cohort followed at Beaujon Hospital, Clichy, France, were described with Kaplan-Meier curves, and linear-mixed models were used to analyze their biomarker changes and the influence of several covariates (splenectomy, diagnosis year, genotype, age at diagnosis and sex). RESULTS : BE occurred before (54 events in 21 patients), but also during, ERT (12 events in 10 patients), with respective frequencies (95% confidence interval) at 10 years of 22.4% (13.3 to 36.3) and 20.0% (10.2 to 36.9). Biomarker slope changes before and during ERT differed significantly for platelets (+190/mm3/year and 7,035/mm3/year, respectively; P < 0.0001) and ferritin (+4% and -14%; P < 0.0001). High ferritin levels and low platelet counts at ERT onset were significantly associated with BE during ERT (P = 0.019 and 0.039, respectively). Covariates significantly influenced biomarker changes (baseline and/or slope): splenectomy affected platelets (baseline and changes), TRAP changes and chitotriosidase changes; diagnosis date influenced ACE and TRAP baseline values; and genotype influenced chitotriosidase baseline and changes. CONCLUSIONS : Platelet counts and ferritin levels and their slope changes at ERT onset seem to predict BE during treatment. Biomarker baseline values and changes are dependent on several covariables

Linking microbial community structure and function during the acidified anaerobic digestion of grass

This research was funded by the Irish Higher Education Authority Program for Research in Third Level Institutions Cycle 5: – PRTLI-5 ESI Ph.D. ENS Program. This work was also supported by the Wellcome Trust (grant number 094476/Z/10/Z for the TripleTOF 5600 mass spectrometer at the University of St Andrews), NERC (grant number NE/L011956/1), and a Royal Irish Academy Mobility Grant.Harvesting valuable bioproducts from various renewable feedstocks is necessary for the critical development of a sustainable bioeconomy. Anaerobic digestion is a well-established technology for the conversion of wastewater and solid feedstocks to energy with the additional potential for production of process intermediates of high market values (e.g. carboxylates). In recent years, first-generation biofuels typically derived from food crops have been widely utilised as a renewable source of energy. The environmental and socioeconomic limitations of such strategy, however, have led to the development of second-generation biofuels utilising, amongst other feedstocks, lignocellulosic biomass. In this context, the anaerobic digestion of perennial grass holds great promise for the conversion of sustainable renewable feedstock to energy and other process intermediates. The advancement of this technology however, and its implementation for industrial applications, relies on a greater understanding of the microbiome underpinning the process. To this end, microbial communities recovered from replicated anaerobic bioreactors digesting grass were analysed. The bioreactors leachates were not buffered and acidic pH (between 5.5 and 6.3) prevailed at the time of sampling as a result of microbial activities. Community composition and transcriptionally active taxa were examined using 16S rRNA sequencing and microbial functions were investigated using metaproteomics. Bioreactor fraction, i.e. grass or leachate, was found to be the main discriminator of community analysis across the three molecular level of investigation (DNA, RNA and proteins). Six taxa, namely Bacteroidia, Betaproteobacteria, Clostridia, Gammaproteobacteria, Methanomicrobia and Negativicutes accounted for the large majority of the three datasets. The initial stages of grass hydrolysis were carried out by Bacteroidia, Gammaproteobacteria and Negativicutes in the grass biofilms, in addition to Clostridia in the bioreactor leachates. Numerous glycolytic enzymes and carbohydrate transporters were detected throughout the bioreactors in addition to proteins involved in butanol and lactate production. Finally, evidence of the prevalence of stressful conditions within the bioreactors and particularly impacting Clostridia was observed in the metaproteomes. Taken together, this study highlights the functional importance of Clostridia during the anaerobic digestion of grass and thus research avenues allowing members of this taxon to thrive should be explored.Publisher PDFPeer reviewe

Emergence des nanotechnologies : Vers un nouveau "modèle industriel "?

Les technologies émergentes comme la microélectronique des années 70, les biotechnologies des années 80-90 ou les nanotechnologies des années 2000 s'expriment sous forme de vagues technologiques (Kahane, 2008) qui sont porteuses de promesses scientifiques et techniques (Pautrat, 2002), de nouveaux marchés, de perspectives de bien-être pour certains (Birraux et al., 2003), de risques, d'incertitudes et d'aliénation pour d'autres (Dupuy et al., 2004). Alors que le développement économique des nanotechnologies ne fait que commencer, plusieurs schémas de développement sont envisageables (Kahane, Mangematin, 2007).Pour plus d'informations consulter le site http://www.nanoeconomics.eu/

Modèle d’activité dans l’instrumentation en biotechnologies

Les acteurs, publics comme privés, conçoivent des stratégies de coopération pour développer de nouvelles compétences et avoir accès aux équipements nécessaires à une production scientifique de qualité. On assiste alors à un enchaînement de décisions stratégiques prises par des acteurs hétérogènes pour investir dans les plates-formes technologiques et organiser les coopérations. À partir d’une analyse comparative des modes de fonctionnement de six plates-formes en sciences de la vie, la formation des modèles d’activité est étudiée. La comparaison des différentes logiques de construction de l’offre de services par les plates-formes permet de préciser les conditions de validité et de survie des plates-formes. Sont ensuite discutées les frontières entre un modèle de gestion publique des plates-formes, fondé sur une politique volontariste d’offre d’équipements scientifiques aux chercheurs, et un modèle économique privé de gestion des plates-formes. Ce texte montre que c’est la difficulté à définir une demande et à jouer un rôle moteur vis-à-vis des offreurs qui conduit les promoteurs de ces plates-formes à proposer une offre qui peine souvent à trouver son public.Scientists collaborate to acquire new competencies and to access to scientific equipment that they require to perform research. Since the development of genomics and tools for «mass gene and protein exploration», instrumentation has become more and more resource-consuming, making sharing research facilities a growing issue. Based on six case studies of the organisation of research facilities in life science, the paper analyses the activity models of research facilities and instrumentations. Focusing on the organisation of large-scale research facilities in life science, it analyses how actors define and shape the access of instrumentation and the supply of services for academics and private scientists. It balances two managerial organisations, the public sector which offers access to equipments to other scientists and the private one which supplies services. The dynamics of each model is discussed as well as the conditions of sustainability according to the different business models

Une élite apolitique dans une économie politisée?

The denazification of German business leaders sheds light on post-war strategies of justification and self-interpretation. Although the occupation forces had well understood that entrepreneurs, owners as well as managers, were stakeholders of the Nazi regime, they generally favored a more flexible approach towards them. Entrepreneurs’ entanglement with the Nazis seemed more ambiguous, less ideologically grounded and less accessible for the formal criteria of the denazification procedure which focused on those who had held political offices or, as public servants, had ensured the relative efficiency of the Nazi state. Examples from the British and French zones of occupied Germany help to understand the imponderability of the procedures, which gave room for maneuver to the business leaders for their defense. The article analyses the difficulties of committees to understand the forms of economic cooperation with the Nazi regime and to assess their profitability, political relevance and impact on the Nazi war effort. Business leaders managed to profit from the lack of knowledge about decision-making structures and the character of their relations with the Nazi regime. They successfully claimed to have been subject to coercion in an unfree economy. At the same time, and somewhat inconsistently, they insisted on the fact that they had done business as usual, driven only by technical and business expertise represented as profoundly nonpolitical. The paper integrates the essence of business historians’ research from the last two decades in a broader reflection about the post-war liquidation of the Nazi society and the self-conception of German economic elites after 1945.Die Entnazifizierung deutscher Wirtschaftsführer wirft Licht auf Nachkriegsstrategien der Rechtfertigung und Selbstinterpretation. Obwohl die Besatzungskräfte verstanden hatten, dass Unternehmer, Firmeneigentümer ebenso wie Manager, Stakeholder des NS-Regimes waren, verfolgten sie generell einen flexibleren Ansatz ihnen gegenüber. Ihre Verstrickung mit den Nazis erschien zweideutiger, weniger ideologisch begründet und weniger zugänglich für die formalen Kriterien des Entnazifizierungsverfahrens, die sich an denjenigen orientierten, die politische Ämter innegehabt oder als Beamte die relative Effizienz des NS-Staates sichergestellt hatten. An Beispielen aus der britischen und französischen Zone des besetzten Deutschland werden die Unwägbarkeiten der Entnazifizierungsverfahren beleuchtet, die Wirtschaftsführern Handlungsspielraum für ihre Verteidigung eröffneten. Der Artikel analysiert die Schwierigkeiten der Entnazifizierungsausschüsse, die Formen der wirtschaftlichen Kooperation mit dem NS-Regime zu verstehen und deren Rentabilität, politische Relevanz und Auswirkungen auf die NS-Kriegsanstrengungen zu bewerten. Wirtschaftsführern gelang es, von dem Mangel an Wissen über Entscheidungsstrukturen und den Charakter ihrer Beziehungen zum NS-Regime zu profitieren. Sie behaupteten erfolgreich, in einer unfreien Wirtschaft unter Zwang gehandelt zu haben. Zugleich bestanden Sie darauf, auch wenn das nicht ganz widerspruchsfrei war, dass sie schlicht ihren Geschäften nachgegangen seien und Business as usual betrieben hätten, angetrieben von technischer und wirtschaftlicher Expertise, die als zutiefst unpolitisch dargestellt wurde. Das Papier integriert zentrale Ergebnisse der unternehmenshistorischen Forschung der letzten zwei Jahrzehnte in eine breitere Reflexion über die Abwicklung der nationalsozialistischen Gesellschaft und das Selbstverständnis der deutschen Wirtschaftselite nach 1945.La dénazification des chefs d’entreprise allemands éclaire les stratégies d’après-guerre de justification et d’auto-interprétation d’un groupe social important. Bien que les forces d’occupation aient compris que les entrepreneurs, qu’ils soient propriétaires ou managers, poursuivaient leurs propres intérêts en tant que « stakeholder » du régime nazi, elles ont généralement adopté une attitude plus souple à leur égard. Leur implication avec les nazis semblait plus ambiguë, moins idéologique et moins accessible aux critères formels du processus de dénazification, qui visaient ceux qui avaient occupé des fonctions politiques ou, en tant que fonctionnaires, assuraient la relative efficacité de l’État nazi. L’impondérabilité des procédures de dénazification, qui a permis aux chefs d’entreprise de se défendre, est examinée à l'aide d'exemples provenant des zones britannique et française de l’Allemagne occupée. L’article analyse les difficultés des comités de dénazification à comprendre les formes de coopération économique avec le régime nazi et à évaluer leur rentabilité, leur pertinence politique et leur impact sur l’effort de guerre nazi. Les chefs d’entreprise ont pu bénéficier du manque de connaissance des structures décisionnelles et de la nature de leurs relations avec le régime nazi. Ils ont prétendu, avec succès, avoir agi sous la contrainte dans une économie non libre. En même temps, ils ont insisté, non sans contradictions, sur le fait qu’ils ne s’occupaient de leurs affaires, du business as usual, en s’appuyant sur une expertise technique et économique présentée comme profondément apolitique. L’article intègre les résultats de la recherche sur l’histoire des entreprises des deux dernières décennies dans une réflexion plus large sur le développement d’après-guerre de la société nationale-socialiste et l’image de soi de l’élite économique allemande après 1945

Efficacy of Oseltamivir-Zanamivir Combination Compared to Each Monotherapy for Seasonal Influenza: A Randomized Placebo-Controlled Trial

Analysis of virological and clinical outcomes from a randomized trial that was terminated early suggest that combined treatment of seasonal influenza in adult outpatients with oseltamivir plus zanamivir is no more effective than either oseltamivir or zanamivir monotherapy

Beyond basic diversity estimates – analytical tools for mechanistic interpretations of amplicon sequencing data

Understanding microbial ecology through amplifying short read regions, typically 16S rRNA for prokaryotic species or 18S rRNA for eukaryotic species, remains a popular, economical choice. These methods provide relative abundances of key microbial taxa, which, depending on the experimental design, can be used to infer mechanistic ecological underpinnings. In this review, we discuss recent advancements in in situ analytical tools that have the power to elucidate ecological phenomena, unveil the metabolic potential of microbial communities, identify complex multidimensional interactions between species, and compare stability and complexity under different conditions. Additionally, we highlight methods that incorporate various modalities and additional information, which in combination with abundance data, can help us understand how microbial communities respond to change in a typical ecosystem. Whilst the field of microbial informatics continues to progress substantially, our emphasis is on popular methods that are applicable to a broad range of study designs. The application of these methods can increase our mechanistic understanding of the ongoing dynamics of complex microbial communities