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Background Phospholipids are important structural and signaling molecules in plant membranes. Some fluorescent dyes can stain general lipids of membranes, but labeling and visualization of specific lipid classes have yet to be developed for most components of the membrane. New techniques for visualizing membrane lipids are needed to further delineate their dynamic structural and signaling roles in plant cells. In this study we examined whether propargylcholine, a bioortholog of choline, can be used to label the major membrane lipid, phosphatidylcholine, and other choline phospholipids in plants. We established that propargylcholine is readily taken up by roots, and that its incorporation is not detrimental to plant growth. After plant tissue is harvested and fixed, a click-chemistry reaction covalently links the alkyne group of propargylcholine to a fluorescently-tagged azide, resulting in specific labeling of choline phospholipids. Results Uptake of propargylcholine, followed by click chemistry with fluorescein or Alexa Fluor 594 azide was used to visualize choline phospholipids in cells of root, leaf, stem, silique and seed tissues from Arabidopsis thaliana. Co-localization with various subcellular markers indicated coinciding fluorescent signals in cell membranes, such as the tonoplast and the ER. Among different cell types in the leaf epidermis, guard cells displayed strong labeling. Mass spectrometry-based lipidomic analysis of the various plant tissues revealed that incorporation of propargylcholine was strongest in roots with approximately 50% of total choline phospholipids being labeled, but it was also incorporated in the other tissues including seeds. Phospholipid profiling confirmed that, in each tissue analyzed, incorporation of the bioortholog had little impact on the pool of choline plus choline-like phospholipids or other lipid species. Conclusion We developed and validated a click-chemistry based method for fluorescence imaging of choline phospholipids using a bioortholog of choline, propargylcholine, in various cell-types and tissues from Arabidopsis. This click-chemistry method provides a direct way to metabolically tag and visualize specific lipid molecules in plant cells. This work paves the way for future studies addressing in situ localization of specific lipids in plants. Electronic supplementary material The online version of this article (10.1186/s13007-018-0299-2) contains supplementary material, which is available to authorized users.

International audience; Background: Serological markers are potentially useful tools for monitoring the progress of malaria control programs , but a better understanding of antibody response dynamics is necessary. The use of a magnetic bead-based immunoassay (MBA) is advantageous compared to ELISA, due to its multiplexing capacity, but limited information is available on the standardization and validation of this assay. Methods: Several parameters for multiplex testing of antibodies to Plasmodium antigens were analysed using a set of 4 antigens and 98 sera from Senegalese rural asymptomatic and urban symptomatic individuals. The 4 antigens included Plasmodium falciparum CSP and PfAMA1 peptides, recombinant P. falciparum MSP4p20 and a Plasmodium malariae CSP (PmCSP) peptide. Comparisons with ELISA were done using MSP4p20 and whole schizont extract (SE) antigens.Results: The use of fewer beads (1000 beads per well instead of 2000) and 5 µg of antigen per 10 6 bead were validated as lower amounts. The use of a carrier protein (BSA) was shown to be critical when using peptides and the effect of a 24 h delayed measures was evaluated (5-25% signal decrease). Analysis of Ab responses showed almost equally high levels and prevalence in all transmission settings. Clear distinctions between rural and urban malaria were noted using PmCSP and SE antigens.Conclusions: This study underlines the importance of further optimization of the MBA technique and highlights the interest of using multistage/multispecies antigens for surveillance of malaria in endemic settings.

We suggest that one way in which economic analysis is useful is by offering a critique of reasoning. According to this view, economic theory may be useful not only by providing predictions, but also by pointing out weaknesses of arguments. It is argued that, when a theory requires a non-trivial act of interpretation, it's roles in producing predictions and offering critiques vary in a substantial way. We offer a formal model i which these different roles can be captured.

Antidepressants effectiveness in major depressive disorder (MDD) is still questioned because the extrapolation of randomized controlled trial (RCT) results to “real life” settings is problematic. The application of the RCT paradigm in a disorder of this type, where global care plays a central role, raises questions regarding the internal and external validity of this type of study. Outcome measurement, attrition rates, the ability of the double‐blind design to control for expectations, placebo response, the representativeness of trial participants and publication bias are major methodological pitfalls. This review discusses these issues. It is illustrated using original data and proposes some alternatives for assessing antidepressant effectiveness via different approaches. Some are easy to implement, such as ecological measures, qualitative approaches, improvement of analytical strategy and improvement of blinding procedures. Some are sophisticated, involving temporary deception to deal with the confounding effect of expectations, and they raise ethical issues. Others resort to external validity, this being the case in observational studies. But all are necessary to explore antidepressant effectiveness. Copyright © 2013 John Wiley & Sons, Ltd.

Der Artikel unternimmt zu beweisen wie eine historische Vorgehensweise dazu beitragen kann verschiedene Probleme der modernen Wirtschaftstheorie besser zu verstehen. Erstens erläutern die Verfasser ihre 'Forschungsmethodologie', um die Relevanz der historischen Analyse in den Wirtschaftswissenschaften widerzuspiegeln. Die Verfasser betonen deren interdisziplinäre Vorgehensweise, da sie die Moral- und politische Philosophie, die Dogmengeschichte, die Wirtschaftstheorie sowie die modernen analytischen Instrumente einschließt. Zweitens präsentieren die Verfasser zwei Beispiele von vollendeten oder laufenden Arbeiten, die auf ihrer Methodologie beruhen. The article aims to stress that historical approach can contribute to address issues faced by modern economic theory. So as to show the relevance of historical analysis in economics, the author's first state the 'methodology' they use in their researches. The author's emphasize their interdisciplinary feature since it involves moral and political philosophy, history of economic thought, economic theory and modern analytical tools. Second, they suggest two examples of works, finished or current, which are based on their methodology.