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Natural selection on flower size in invasive Cytisus scoparius along an elevation gradient

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Journal of Plant Ecology 2020年第2期13卷 165-170页

作者： Robert Frederick Bode Catherine dufresne Department of Natural Sciences College of Arts and SciencesSaint Martin’s UniversityLaceyWA 98503USA

Aims Established invasive plant species have more diverse gene pools than single populations in their home *** genetic and often phenotypic variation allows for natural selection to act and produce rapid adaptations as an invasive species interacts with other members of the *** an invasive flowering plant,interactions with pollinators may lead to adaptations to a heterogeneous pollinator *** variation in the pollinator community in the invaded range is similar to variation in the native range,suggesting that adaptations may mirror patterns seen in the home *** this study,we investigated variation in flower size in Cytisus scoparius,an invasive leguminous shrub,along an elevation *** This study took place in the Capitol State Forest in Washington *** measured flower widths and the proportion of visited flowers,using 10 plants per field *** were located along an elevation gradient and were visited three times to measure phenological variation on a per-plant *** Findings We saw positive selection for flower size,albeit without a distinct pattern of higher selection at higher *** pattern of natural selection could be seen both in terms of pollinator visitation rates and in seed *** also found that the largest contributor to changes in seed production was not elevation or flower size but management practices.

关键词： invasive pollinator evolution Cytisus elevation

Glycine-extended gastrin activates two independent tyrosine-kinases in upstream of p85/p110 phosphatidylinositol 3-kinase in human colonic tumour cells

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World Journal of Gastroenterology 2006年第12期12卷 1859-1864页

作者： Audrey Ferrand Aline Kowalski-Chauvel Claudine Bertrand Daniel Fourmy Marlene dufresne Catherine Seva Julie Pannequin INSERM U.531 Groupe de Recherche de Biologie et Pathologie DigestivesIFR31Institut Louis BugnardBP 8422531432 toulouse Cedex 4France University of Melbourne Department of Surgery Austin CampusARMCHeidelbergVictoria 3084Australia

AIM： To investigate whether Src, JAK2 and phosphatidylinositol 3-kinase （PI3K） pathways are involved in the proliferation of human colonic tumour cells induced by glycine-extended gastrin （G-gly）, the precursor of the mature amidated gastrin and to elucidate the molecular interaction between these three kinases in response to this peptide. METHODS： Using the human colonic tumour cell line HCT116 as a model, we first measured the activation of PI3K, p60-Src and JAK2 in response to G-gly by in vitro kinase assays. Then we investigated the involvement of these kinases in G-gly-induced cell proliferation by MTT test. RESULTS： G-gly stimulation induced p60-Src, JAK2 and PI3K activation in HCT116. The different pathways were involved in proliferation of human colon cancer cells induced by G-gly. Furthermore, we found that both Src and JAK2 were necessary to PI3K regulation by this peptide. However, we did not find any cross-talk between the two tyrosine kinases. CONCLUSION： Our results suggest that the p60-Src/ PI3K and JAK2/PI3K pathways act independently to mediate G-gly proliferative effect on human colonic tumour cells.

关键词： Colon cancer Src JAK2 Phosphatidylinositol 3-kinase Glycine-extended gastrin

Preparation and Properties of Cellulose Nanomaterials

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Paper And Biomaterials 2020年第3期5卷 1-13页

作者： Alain dufresne UniversitéGrenoble Alpes CNRSGrenoble INPLGP2GrenobleF-38000France

Cellulose is the most abundant biomass material in nature and it is mainly extracted from natural or lignocellulosic *** purification,cellulose fibers exhibit two interesting features for their further transformation into nanomaterials:a hierarchical and multi-level strcture,and a semicrystalline *** forms of cellulose nanomaterials,resulting from a top-down deconstructing strategy(cellulose nanocrystals(CNCs),cellulose nanofibrils(CNFs))or bottom-up strategy(bacterial cellulose(BC))can be *** mechanical shearing actions applied to cellulosic fibers release more or less the nanofibrils individually.A controlled strong acid hydrolysis treatment can be applied to cellulosic fibers allowing dissolution of non-crystalline *** cellulose nanomaterials have been the focus of an exponentially increasing number of works or reviews devoted to understand such materials and their *** have a high potential for an emerging *** the nanoscale,cellulose exhibits specific properties broadening the applications of this naturally occurring *** overview of existing methods for the preparation of cellulose nanomaterials and their specific properties that outperform and contrast with cellulose in the microscale is proposed.

关键词： cellulose nanomaterial nanocrystal nanofibril preparation properties

Mechanism for Src activation by the CCK2 receptor:Patho-physiological functions of this receptor in pancreas

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World Journal of Gastroenterology 2006年第28期12卷 4498-4503页

作者： Audrey Ferrand Sebastien Vatinel Aline Kowalski-Chauvel Claudine Bertrand Chantal Escrieut Daniel Fourmy Marlene dufresne Catherine Seva dufresne Catherine SevaINSERM U 531IFR 31Institut Louis BugnardBP 8422531432 Toulouse cedex 4France

AIM： TO investigate in vivo, whether CCK2 receptors （CCK2R） regulate proteins known to play a crucial role in cell proliferation and cancer development and analyse in vitro the molecular mechanisms that lead to Src activation; in particular, to identify the domains within the CCK2R sequence that are implicated in this activation. METHODS： The expression and activation of Src and ERK were studied in vivo using immunofluorescence and western-blot techniques. We used pancreatic tissues derived from wild type or Elas-CCK2 mice that expressed the CCK2R in pancreatic acini, displayed an increased pancreatic growth and developed preneoplastic lesions. The pancreatic tumor cell line AR4-2J expressing the endogenous CCK2R or COS-7 cells transiently transfected with wild type or mutant CCK2R were used as in vitro models to study the mechanism of Src activation. Src activation was measured by in vitro kinase assays, ERK activation by western blot using antiphospho-ERK antibodies and the involvement of Src in gastrin-induced cell proliferation by MTT test. RESULTS： We showed in vivo that the targeted CCK2R expression in the pancreas of Elas-CCK2 mice, led to the activation of Src and the ERK pathway. Src was activated upstream of the ERK pathway by the CCK2R in pancreatic tumoral cells and contributed to the proliferative effects mediated by this receptor. In vitro results demonstrated that activation of the Src/ERK pathway by the CCK2R required the NPXXY motif, located within the CCK2R sequence at the end of the 7^th transmembrane domain, and suggested the putative role of Gq in this mechanism. CONCLUSION： Deregulation of the Src/ERK pathway by the CCK2R might represent an early step that contributes to cell proliferation, formation of preneoplastic lesions and pancreatic tumor development.

关键词： Gastrin, Src Pancreas CCK2 receptor

Orchestration of occludins, claudins, catenins and cadherins as players involved in maintenance of the blood-epididymal barrier in animals and humans

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Asian Journal of Andrology 2007年第4期9卷 463-475页

作者： Daniel G. Cyr Mary Gregory Evemie Dube Julie dufresne Peter T. K. Chan Louis Hermo INRS-Institut Armand Frappier Universite du Quebec 245 Hymus Boulevard Pointe Claire QC H9R 1G6 Canada Department of Urology Royal Victoria Hospital McGill University Montreal QC H3A 1A1 Canada Department of Anatomy and Cell Biology McGill University Montreal QC H3A 2B2 Canada

Although spermatozoa are formed during spermatogenesis in the testis, testicular spermatozoa are immature and cannot swim or fertilize. These critical spermatozoal functions are acquired in the epididymis where a specific luminal environment is created by the blood-epididymal barrier; proteins secreted by epididymal principal cells bind to maturing spermatozoa and regulate the maturational process of the spermatozoa. In the epididymis, epithelial cell-cell interactions are mediated by adhering junctions, necessary for cell adhesion, and by tight junctions, which form the blood-epididymal barrier. The regulation of these cellular junctions is thought to represent a key determinant in the process of sperm maturation within the epididymis. Tight junctions between adjacent principal cells permit the formation of a specific microenvironment in the lumen of the epididymis that is essential for sperm maturation. Although we have made significant progress in understanding epididymal function and the blood-epididymal barrier, using animal models, there is limited information on the human epididymis. If we are to understand the normal and pathological conditions attributable to human epididymal function, we must clearly establish the physiological, cellular and molecular regulation of the human epididymis, develop tools to characterize these functions and develop clinical strategies that will use epididymal functions to improve treatment of infertility. （Asian J Androl 2007 July; 9： 463- 475）

关键词： claudins cadherins catenins human rat mouse tight junction adherens junction

Isolation and Characterization of Cellulose Nanofibers from Argentine Tacuara Cane(Guadua Angustifolia Kunth)

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Journal of Renewable Materials 2019年第4期7卷 373-381页

作者： C.A.Rodríguez Ramírez Fleur Rol Julien Bras Alain dufresne Nancy Lis Garcia Norma D'Accorso Universidad de Buenos Aires Facultad de Ciencias Exactas y NaturalesDepartamento de Química OrgánicaBuenos Aires Argentina CONICET-Universidad de Buenos Aires.Centro de Investigación en Hidratos de Carbono(CIHIDECAR).Buenos Aires Argentina Univ.Grenoble Alpes CNRSGrenoble INPLGP2F-38000France

New trends in the area of material improvement are the use of natural nano-charges from renewable biomass,improving the value and sustainability of our country’s natural *** is widely used in many countries of the world,although in Argentina,despite being commercialized and exported for the manufacture of wood floors,it goes unnoticed despite having native ***,researchers identified the native and exotic species present in our country and are working on novel *** this context,it is proposed the Argentine Tacuara Cane(Guadua Angustifolia Kunth),endemic plant as a new source of nanocellulosic materials,where stem fibers have been isolated using a green method achieving with yield of 45.9%of *** cellulose nanofibrils(CNF)were obtained using a green homogenization *** CNF exhibited web-like long fibrous structure with the diameter of 10-20 *** crystallinity was 65.5%,as for the onset temperature of thermal decomposition was 212°*** nanocellulose isolated from the Tacuara Cane seed fibers has a high potential to be used as a new source of cellulose-based nanofiller for the reinforcement of bionanocomposite films.

关键词： Cellulose nanofibers green valorization

Norine: A powerful resource for novel nonribosomal peptide discovery

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Synthetic and Systems Biotechnology 2016年第2期1卷 89-94页

作者： M.Pupin Q.Esmaeel A.Flissi Y.dufresne P.Jacques V.Leclère Univ Lille CNRSCentrale LilleUMR 9189-CRIStAL-Centre de Recherche en Informatique Signal et Automatique de LilleF-59000 LilleFrance Inria-Lille Nord Europe Villeneuve d’Ascq Cedex F-59655France Univ Lille INRAISAUniv ArtoisUniv Littoral Coce d’OpaleEA 7394-ICV-Institut Charles ViolletteF-59000 LilleFrance Bioindustry Unit Gembloux Agro-Bio Tech-University of LiegePassage des Déportés2Gembloux 5030Belgium

Since its first release in 2008,Norine remains the unique resource completely devoted to nonribosomal peptides(NRPs).They are very attractive microbial secondary metabolites,displaying a remarkable diversity of structure and ***(http://***/NRP)includes a database now containing more than 1160 annotated peptides and user-friendly interfaces enabling the querying of the database,through the annotations or the structure of the *** tools are associated for structural comparison of the compounds and prediction of their biological *** this paper,we start by describing the knowledgebase and the dedicated *** then present some user cases to show how useful Norine is for the discovery of novel nonribosomal peptides.

关键词： Norine Nonribosomal peptides Secondary metabolites Database

Communication Mediated through Natural Language Generation in Big Data Environments: The Case of Nomao

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Journal of Computer and Communications 2017年第6期5卷 125-148页

作者： Jean-Sébastien Vayre Estelle Delpech Aude dufresne Céline Lemercier CERTOP (UMR-5044) University of Toulouse Jean Jaurès Toulouse France Human Factors Airbus Blagnac France LRCM University of Montréal Montréal Québec CLLE (UMR-5263) University of Toulouse Jean Jaurès Toulouse France

Along with the development of big data, various Natural Language Generation systems (NLGs) have recently been developed by different companies. The aim of this paper is to propose a better understanding of how these systems are designed and used. We propose to study in details one of them which is the NLGs developed by the company Nomao. First, we show the development of this NLGs underlies strong economic stakes since the business model of Nomao partly depends on it. Then, thanks to an eye movement analysis conducted with 28 participants, we show that the texts generated by Nomao’s NLGs contain syntactic and semantic structures that are easy to read but lack socio-semantic coherence which would improve their understanding. From a scientific perspective, our research results highlight the importance of socio-semantic coherence in text-based communication produced by NLGs.

关键词： Big Data Natural Language Generation Socio-Semantic Coherence Cognitive Load Reading Eye Tracking

Review of Cellulose Nanocrystal-based Fluorophore Materials and Their Application in Metal Ion Detection

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Paper And Biomaterials 2018年第4期3卷 45-61页

作者： Ya Wang Alain dufresne Peter R. Chang XiaoZhou Ma Jin Huang School of Chemistry and Chemical Engineering Joint International Research Laboratory of Biomass-Based Macromolecular Chemistry and Materials Southwest University Chongqing 400715 China Université Grenoble Alpes CNRS Grenoble INP LGP2 F-38000 Grenoble France Bioproducts and Bioprocesses National Science Program Agriculture and Agri-Food Canada 107 Science Place Saskatoon SK S7N0X2 Canada

Cellulose nanocrystals （CNCs）, a unique and promising natural material extracted from native cellulose, have attracted considerable attention owing to their physical properties and special surface chemistry. This review focuses on chemical conjugation strategies that can be used for preparation of ？uorescent-molecule labeled CNCs and the development of biomaterials. Furthermore, their application in the detection of metal ions and future development prospects are discussed. We hope to provide a clear view of the strategies for surface fluorescent modifcation of CNCs and their application in detection of metal ions.

关键词： fluorescent cellulose nanocrystals detection of metal ions sensors optical imaging biomaterial