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671.
Thomas Bawin Fawrou Seye Slimane Boukraa Jean-Yves Zimmer Fara Nantenaina Raharimalala Quentin Zune 《Biocontrol Science and Technology》2016,26(5):617-629
The spore productivity and insecticidal activity of two opportunistic insect pathogenic Aspergillus species (namely: Aspergillus clavatus Desmazieres and Aspergillus flavus Link (Ascomycota: Eurotiales, Trichocomaceae)) were compared to Metarhizium anisopliae sensu lato (Metchnikoff) Sorokin (Ascomycota: Hypocreales, Clavicipitaceae) for mosquito (Diptera: Culicidae) control. The production of aerial spores on wheat bran and white rice was investigated in solid-, semi-solid-, and liquid-state media supplemented with a nutritive solution. Wheat bran-based media increased the spore yield in solid-state from three to sevenfold: A. clavatus produced 48.4?±?5.2 and 15.7?±?1.6?×?108 spores/g, A. flavus produced 22.3?±?4.1 and 3.1?±?2.5?×?108 spores/g, and M. anisopliae produced 39.6?±?6.5 and 13.1?±?2.6?×?108 spores/g of wheat bran or white rice, respectively. A. clavatus, A. flavus and M. anisopliae spores harvested from wheat bran-based solid-state media showed lethal concentrations (LC50) of 1.1, 1.8, and 1.3?×?108 spores/ml against Culex quinquefasciatus Say larvae in 72?h. Because A. clavatus and M. anisopliae displayed similar features when cultured under these conditions, our results suggest that insect pathogenic Aspergillus species may be as productive and virulent against mosquito larvae as a well-recognised entomopathogenic fungus. 相似文献
672.
Human immunodeficiency virus type 1 virological synapse formation in T cells requires lipid raft integrity 下载免费PDF全文
Human immunodeficiency virus type 1 (HIV-1) can spread directly between T cells by forming a supramolecular structure termed a virological synapse (VS). HIV-1 envelope glycoproteins (Env) are required for VS assembly, but their mode of recruitment is unclear. We investigated the distribution of GM1-rich lipid rafts in HIV-1-infected (effector) T cells and observed Env colocalization with polarized raft markers GM1 and CD59 but not with the transferrin receptor that is excluded from lipid rafts. In conjugates of effector T cells and target CD4+ T cells, GM1, Env, and Gag relocated to the cell-cell interface. The depletion of cholesterol in the infected cell dispersed Env and GM1 within the plasma membrane, eliminated Gag clustering at the site of cell-cell contact, and abolished assembly of the VS. Raft integrity is therefore critical for Env and Gag co-clustering and VS assembly in T-cell conjugates. 相似文献
673.
Jean-Pierre Vacher Jérôme Chave Francesco Gentile Ficetola Guilhem Sommeria-Klein Shengli Tao Christophe Thébaud Michel Blanc Agustín Camacho José Cassimiro Timothy J. Colston Maël Dewynter Raffael Ernst Philippe Gaucher Jerriane Oliveira Gomes Rawien Jairam Philippe J. R. Kok Jucivaldo Dias Lima Quentin Martinez Christian Marty Brice P. Noonan Pedro M. Sales Nunes Paul Ouboter Renato Recoder Miguel Trefaut Rodrigues Andrew Snyder Sérgio Marques-Souza Antoine Fouquet 《Journal of Biogeography》2020,47(8):1781-1791
674.
Quentin S Hanley Keith A Lidke Rainer Heintzmann Donna J Arndt-Jovin Thomas M Jovin 《Cytometry. Part A》2005,67(2):112-118
BACKGROUND: The programmable array microscopes (PAMs) are a family of instruments incorporating arbitrary control of the patterns of illumination and/or detection. The PAM can be used in sectioning and nonsectioning modes, thereby constituting a useful platform for fluorescence lifetime imaging. METHODS AND RESULTS: We used a PAM for acquisition of optically sectioned and widefield fluorescence lifetime images, in which contrast was increased predominantly by suppressing out-of-focus light contributions. We simulate, display, and discuss the effects of blurring and fluorophore heterogeneity on lifetime imaging in widefield and confocal configurations. CONCLUSION: Sectioning improves the quality of lifetime images of samples with multiple fluorophores or spatially varying F?rster resonance energy transfer. 相似文献
675.
David Hardy Aurore Besnard Mathilde Latil Grégory Jouvion David Briand Cédric Thépenier Quentin Pascal Aurélie Guguin Barbara Gayraud-Morel Jean-Marc Cavaillon Shahragim Tajbakhsh Pierre Rocheteau Fabrice Chrétien 《PloS one》2016,11(1)
Background
A longstanding goal in regenerative medicine is to reconstitute functional tissus or organs after injury or disease. Attention has focused on the identification and relative contribution of tissue specific stem cells to the regeneration process. Relatively little is known about how the physiological process is regulated by other tissue constituents. Numerous injury models are used to investigate tissue regeneration, however, these models are often poorly understood. Specifically, for skeletal muscle regeneration several models are reported in the literature, yet the relative impact on muscle physiology and the distinct cells types have not been extensively characterised.Methods
We have used transgenic Tg:Pax7nGFP and Flk1GFP/+ mouse models to respectively count the number of muscle stem (satellite) cells (SC) and number/shape of vessels by confocal microscopy. We performed histological and immunostainings to assess the differences in the key regeneration steps. Infiltration of immune cells, chemokines and cytokines production was assessed in vivo by Luminex®.Results
We compared the 4 most commonly used injury models i.e. freeze injury (FI), barium chloride (BaCl2), notexin (NTX) and cardiotoxin (CTX). The FI was the most damaging. In this model, up to 96% of the SCs are destroyed with their surrounding environment (basal lamina and vasculature) leaving a “dead zone” devoid of viable cells. The regeneration process itself is fulfilled in all 4 models with virtually no fibrosis 28 days post-injury, except in the FI model. Inflammatory cells return to basal levels in the CTX, BaCl2 but still significantly high 1-month post-injury in the FI and NTX models. Interestingly the number of SC returned to normal only in the FI, 1-month post-injury, with SCs that are still cycling up to 3-months after the induction of the injury in the other models.Conclusions
Our studies show that the nature of the injury model should be chosen carefully depending on the experimental design and desired outcome. Although in all models the muscle regenerates completely, the trajectories of the regenerative process vary considerably. Furthermore, we show that histological parameters are not wholly sufficient to declare that regeneration is complete as molecular alterations (e.g. cycling SCs, cytokines) could have a major persistent impact. 相似文献676.
Oihane Abiega Sol Beccari Irune Diaz-Aparicio Agnes Nadjar Sophie Layé Quentin Leyrolle Diego Gómez-Nicola María Domercq Alberto Pérez-Samartín Víctor Sánchez-Zafra I?aki Paris Jorge Valero Julie C. Savage Chin-Wai Hui Marie-ève Tremblay Juan J. P. Deudero Amy L. Brewster Anne E. Anderson Laura Zaldumbide Lara Galbarriatu Ainhoa Marinas Maria dM. Vivanco Carlos Matute Mirjana Maletic-Savatic Juan M. Encinas Amanda Sierra 《PLoS biology》2016,14(9)
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679.
The FtsK protein is required for septum formation in Escherichia coli and as a DNA translocase for chromosome processing while the septum closes. Its domain of action on the chromosome overlaps the replication terminus region, which lies between replication pause sites TerA and TerC. An extra Ter site, PsrA*, has been inserted at a position common to the FtsK and terminus domains. It is well tolerated, although it compels replication forks travelling clockwise from oriC to stall and await arrival of counter-clockwise forks. Elevated recombination has been detected at the stalled fork. Analysis of PsrA*-induced homologous recombination by an excision test revealed unique features. (i) rates of excision near PsrA* may fluctuate widely from clone to clone, a phenomenon we term whimsicality, (ii) excision rates are nevertheless conserved for many generations, a phenomenon we term memorization; their metastability at the clone level is explainable by frequent shifting between three cellular states--high, medium and low probability of excision, (iii) PsrA*-induced excision is RecBC-independent and is strongly counteracted by FtsK, which in addition is involved in its whimsicality and (iv) whimsicality disappears as the distance from the pause site increases. Action of FtsK at a replication fork was unexpected because the factor was thought to act on the chromosome only at septation, i.e. after replication is completed. Idiosyncrasy of PsrA*-induced recombination is discussed with respect to possible intermingling of replication, repair and post-replication steps of bacterial chromosome processing during the cell cycle. 相似文献
680.
Antonio G. Valdecasas María L. Peláez Quentin D. Wheeler 《Cladistics : the international journal of the Willi Hennig Society》2014,30(2):215-223
Names in taxonomy have seven different and important properties, some due to their existence in the context of classifications. Names confer or facilitate individuation, information storage and retrieval, and set theories of relationships, explanatory power, testable predictions, conceptual power, and language. No other way of naming in science is so powerful. And this is possible because taxonomic naming is done with full consideration of the theoretical specification of empirical data (characters) and their correspondence among taxa via homology statements. Since Darwin and Hennig, sets of homologous characters distributed among taxa allow precise hypotheses of a genealogical relationship, and this relationship is reflected in the way naming results in a classification. 相似文献