WorldWideScience

Sample records for biologie gebrder borntrger

  1. Biologie en criminologie

    NARCIS (Netherlands)

    WODC

    2006-01-01

    Ruim zes jaar na het themanummer 'Biologische factoren van agressief gedrag' (2000) is er nu opnieuw een speciale aflevering over de verhouding tussen biologie en criminologie. Een belangrijke aanleiding zijn de vele onderzoeken naar biologische factoren van psychopathie, agressie, antisociaal

  2. Biologie en criminologie

    NARCIS (Netherlands)

    WODC

    2006-01-01

    Ruim zes jaar na het themanummer 'Biologische factoren van agressief gedrag' (2000) is er nu opnieuw een speciale aflevering over de verhouding tussen biologie en criminologie. Een belangrijke aanleiding zijn de vele onderzoeken naar biologische factoren van psychopathie, agressie, antisociaal gedra

  3. Meganisisme, vitalisme en holisme in die Biologie

    Directory of Open Access Journals (Sweden)

    P.J. Botha

    1963-03-01

    Full Text Available Die Biologie word omskryf as die wetenskap van die lewende wesens (organismes. Die lewe staan dus in die brandpunt van die biologiese studie en ondersoek. Vra ons ons egter af wat onder „lewe” verstaan word, besef ons dadelik dat ons hier met ’n uiters moeilik definieerbare begrip te doen het. In verband met die aard van lewe het daar onder die bioloë en natuurfilosowe veral twee denkrigtings posgevat, nl. meganisisme en vitalism.

  4. Effectieve kenmerken van een digitaal biologie practicum in het hoger onderwijs : analyse van logfiles met een onderwijseffectiviteitsmodel

    NARCIS (Netherlands)

    Beetsma, IJtje

    2010-01-01

    Het onderzochte digitale biologie practicum is ingevoerd als vervanging van het gebruik van proefdieren in het onderwijs en wordt al jaren met succes in het universitaire onderwijs gebruikt. De vervanging van het gebruik van proefdieren bestaat uit videobeelden van experimenten. In voorliggend onder

  5. Thaler Konrad (wissenschaftliche Redaktion (2004: Diversität und Biologie von Webspinnen, Skorpionen und anderen Spinnentieren. Diversity and biology of spiders, scorpions and other arachnids

    Directory of Open Access Journals (Sweden)

    Blick, Theo

    2004-11-01

    Full Text Available book review: Thaler Konrad (wissenschaftliche Redaktion (2004: Diversität und Biologie von Webspinnen, Skorpionen und anderen Spinnentieren. Diversity and biology of spiders, scorpions and other arachnids.

  6. Vrouwen, een minderheid? Literatuuronderzoek naar genderverschillen in neurofysiologisch onderzoek en verslag van een mainstreaming project van het biologie -onderwijs aan de Rijksuniversiteit Groningen.

    NARCIS (Netherlands)

    Pol-Meijer Margriet M. Th. van der, [No Value; Butter, Maureen E.

    2003-01-01

    Dit rapport doet verslag van een gender mainstreaming project in het medisch biologisch onderwijs aan het Opleidingsinstituut Biologie van de Rijksuniversiteit Groningen. Aanleiding tot dit project vragen van WECF (Women in Europe for a Common Future) over genderverschillen met betrekking tot

  7. La squille des eaux tunisiennes : eco-biologie, pêche et opportunités de valorisation

    OpenAIRE

    Mili, Sami

    2013-01-01

    La squille Squilla mantis (L., 1758) est un Stomapode très abondant le long des côtes tunisiennes. Cette ressource benthique est considérée comme rejet et elle n’est pas exploitée en Tunisie par défaut de tradition de consommation. La haute valeur commerciale de la squille sur les marchés internationaux incite à viser la pêche de cette espèce en vue de l’exporter. Ce travail représente la première base de données se rapportant à l’éco-biologie et aux qualités biochimiques de la squille S. man...

  8. Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

    Science.gov (United States)

    Varlet, Madeleine

    Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche

  9. Bildanalyse in Medizin und Biologie

    Science.gov (United States)

    Athelogou, Maria; Schönmeyer, Ralf; Schmidt, Günther; Schäpe, Arno; Baatz, Martin; Binnig, Gerd

    Heutzutage sind bildgebende Verfahren aus medizinischen Untersuchungen nicht mehr wegzudenken. Diverse Methoden - basierend auf dem Einsatz von Ultraschallwellen, Röntgenstrahlung, Magnetfeldern oder Lichtstrahlen - werden dabei spezifisch eingesetzt und liefern umfangreiches Datenmaterial über den Körper und sein Inneres. Anhand von Mikroskopieaufnahmen aus Biopsien können darüber hinaus Daten über die morphologische Eigenschaften von Körpergeweben gewonnen werden. Aus der Analyse all dieser unterschiedlichen Arten von Informationen und unter Konsultation weiterer klinischer Untersuchungen aus diversen medizinischen Disziplinen kann unter Berücksichtigung von Anamnesedaten ein "Gesamtbild“ des Gesundheitszustands eines Patienten erstellt werden. Durch die Flut der erzeugten Bilddaten kommt der Bildverarbeitung im Allgemeinen und der Bildanalyse im Besonderen eine immer wichtigere Rolle zu. Gerade im Bereich der Diagnoseunterstützung, der Therapieplanung und der bildgeführten Chirurgie bilden sie Schlüsseltechnologien, die den Forschritt nicht nur auf diesen Gebieten maßgeblich vorantreiben.

  10. Microscopie par rayons X dans la fenêtre de l'eau : faisabilité et intérêt pour la biologie d'un instrument de laboratoire

    Science.gov (United States)

    Adam, J. F.; Moy, J. P.

    2005-06-01

    La biologie étudie des structures ou des phénomènes sub-cellulaires. Pour cela la microscopie est la technique d'observation privilégiée. La résolution spatiale de la microscopie optique s'avère bien souvent insuffisante pour de telles observations. Les techniques plus résolvantes, comme la microscopie électronique par transmission sont souvent destructrices et d'une complexité peu adaptée aux besoins des biologistes. La microscopie par rayons X dans la fenêtre de l'eau permet l'imagerie rapide de cellules dans leur milieu naturel, nécessite peu de préparation et offre des résolutions de quelques dizaines de nanomètres. De plus, il existe un bon contraste naturel entre les structures carbonées (protéines, lipides) et l'eau. Actuellement cette technique est limitée aux centres de rayonnement synchrotron, ce qui impose une planification et des déplacements incompatibles avec les besoins de la biologie. Un tel microscope fonctionnant avec uns source de laboratoire serait d'une grande utilité. Ce document présente un état de l'art de la microscopie par rayons X dans la fenêtre de l'eau. Un cahier des charges détaillé pour un appareil de laboratoire ayant les performances optiques requises par les biologistes est présenté et confronté aux microscopes X de laboratoire déjà existants. Des solutions concernant la source et les optiques sont également discutées.

  11. Banking of environmental samples for short-term biochemical and chemical monitoring of organic contamination in coastal marine environments: the GICBEM experience (1986-1990). Groupe Interface Chimie Biologie des Ecosystèmes, Marins.

    Science.gov (United States)

    Garrigues, P; Narbonne, J F; Lafaurie, M; Ribera, D; Lemaire, P; Raoux, C; Michel, X; Salaun, J P; Monod, J L; Romeo, M

    1993-11-01

    The GICBEM (Groupe Interface Chimie Biologie des Ecosystèmes Marins) program consists of an evaluation of the ecosystem health status in the Mediterranean Sea mainly based on chemical and biochemical approaches. Specific chemical contaminants (polycyclic aromatic hydrocarbons (PAH), polychlorobiphenyls (PCB), heavy metals) in waters, sediments, and related biotransformation indicators in target organisms (mussels, fish) have been selected for a complete survey of the coastal waters. In order to provide an appropriate sampling program for standardization for each sampling cruise, various aspects have been studied: (a) parameters for the choice of the sample sites; (b) ways of collection the samples (waters, sediments, marine organisms); and (c) preparation of the samples for a short term storage on board ship and for further analyses in the ground laboratory. Methods of preparation and storage of the samples are described and could be used to initiate an environmental banking program including both possible retrospective analyses of chemical pollutants and biochemical indicators. Moreover, the correlation between chemicals (PAH) and biochemical (mixed function oxygenase activities) parameters has been studied and this demonstrates the capability of the enzyme activities as reliable pollution biomarkers.

  12. Qu’est-ce qui fait courir les filles vers la classe préparatoire scientifique Biologie, Chimie, Physique et Sciences de la Terre (BCPST ? What attracts girls in science classes: Biology, Chemistry, Physics and Earth Studies?

    Directory of Open Access Journals (Sweden)

    Christine Fontanini

    2011-10-01

    Full Text Available Cet article a pour objectif de comprendre pourquoi les filles sont nombreuses (70 % à s’engager vers la classe préparatoire scientifique Biologie, Chimie, Physique, Sciences de la Terre (BCPST alors qu’elles restent minoritaires dans les autres préparations scientifiques (Pons, 2007. Comment se sont construits pour ces étudiants et étudiantes, leur projet et leur parcours scolaire vers cette classe préparatoire « bio-véto » ? Quelles sont leurs motivations pour cette filière menant aux professions de vétérinaire et d’ingénieur agronome ? Quelles sont les écoles les plus convoitées ? Quels sont leurs projets professionnels ? Sont-ils différents entre les filles et les garçons ? Pour tenter de répondre à ces questions, nous avons mené une recherche par questionnaire, courant septembre 2008, auprès de 163 élèves de 4 classes préparatoires BCPST de première année (113 filles et 50 garçons des 3 lycées toulousains proposant cette filière dans l’académie. Les filles sont largement majoritaires en classes préparatoires BCPST car leurs débouchés apparaissent comme plus attractifs pour les filles, notamment les écoles vétérinaires.This paper examines why girls are more numerous (70% in the scientific preparatory classes BCPST (Biology, Chemistry, Physics and Earth whereas they are a minority in the other scientific preparatory classes (Pons, 2007. How have female and male built their occupational preferences and their school choices for this preparatory class “biology – vet science”? What are their motivations for this pathway which prepares for veterinarian and agricultural engineer? What are the most desired schools? What are their professional plans? Are they different between girls and boys? In order to answer these questions, a questionnaire survey was conducted in September 2008, on a sample of 163 pupils (113 girls and 50 boys from 4 first year preparatory classes BCPST in 3 Toulousian high

  13. Biologie nodaler peripherer T-Zell-Lymphome

    OpenAIRE

    Bonzheim, Irina

    2008-01-01

    Ziel der in der vorliegenden Arbeit beschriebenen Untersuchungen war eine nähere Charakterisierung von peripheren T-Zell-Lymphomen (PTCL). Hierfür wurden im Wesentlichen zwei Ansätze verfolgt: Im ersten Ansatz sollten für die Tumorzellen der verschiedenen PTCL korrespondierende Normalzellen identifiziert werden, um deren Eigenschaften und Funktionen mit denen der neoplastischen Zellen vergleichen zu können. Im zweiten Ansatz sollten die hierdurch gewonnenen Erkenntnisse in weiterführende Unte...

  14. Biologie en ecologie van Melganzevoet (Chenopodium album)

    NARCIS (Netherlands)

    Brand, van den W.G.M.

    1985-01-01

    Behandeling van eigenschappen en het gedrag van een van de lastigste onkruidsoorten in de Nederlandse akkerbouw. Veel aandacht wordt besteed aan de kieming, opkomst en groei. Verder wordt ingegaan op factoren die de kieming en opbrengst beinvloeden; opbrengstperiodiciteit; groei als monocultuur en i

  15. Zur Biologie des marinen Heterotardigraden Tetrakentron synaptae

    Science.gov (United States)

    Kristensen, R. M.

    1980-06-01

    The life cycle of Tetrakentron synaptae Cuénot, 1892, a tardigrade closely associated with the sea cucumber Leptosynapta galliennei Herapath, was investigated in the littoral zone at Roscoff (France). Eggs and juveniles were found only in June and July, adults only from May to October. There are vagile males and stationary dwarf males. The dorsoventrally flattened body, an enlarged slimy epicuticle in females and dwarf males, the full set of claws also in juveniles, and the anus, which is in a dorsocaudal position, are indicative for an epizoic, sessile life. There is strong evidence that T. synaptae punctures the cells of L. galliennei and sucks out their content, which is indicative of parasitism.

  16. Evolusie: Die misverstand tussen teologie en biologie

    Directory of Open Access Journals (Sweden)

    P. J. van Dyk

    1993-01-01

    Full Text Available Evolution: The misunderstanding between theology and biology Theological reaction to the theory of biological evolution ranged from an outright rejection to positive acceptance. Both these extreme viewpoints are, however, often mistaken in their basic assumptions. Rejection of evolution is often based on fundamentalist preconceptions th a t are both unnecessary and inconsistent with the Bible. On the other hand, acceptance of the theory of evolution is often based on an idealistic definition of evolution that is incongruous with the materialistic definition used by biologists.

  17. HBA1c: clinical and biological agreement for standardization of assay methods. Report by the experts of ALFEDIAM (Association de Langue Française pour lEtude du Diabète et des Maladies Métabolique) and SFBC (Société Française de Biologie Clinique).

    Science.gov (United States)

    Gillery, P; Bordas-Fonfrède, M; Chapelle, J P; Drouin, P; Hue, G; Lévy-Marchal, C; Périer, C; Sélam, J L; Slama, G; Thivolet, C; Vialettes, B

    1999-09-01

    Glycohaemoglobin, and particularly haemoglobin A1c(HbA1c), assays have been used for many years to retrospectively evaluate the glycaemic control of diabetic patients. Cut-off values have been established for deciding treatment modifications. The techniques used in the laboratories however exhibit varying quality, and all of them are not yet standardized. The consequence is an under-utilization of this test, especially in non-hospital practice. In this context, working groups of Société Française de Biologie Clinique (SFBC), Association de Langue Française pour l'Etude du Diabète et des Maladies Métaboliques (ALFEDIAM) and Société Française d'Endocrinologie (SFE) have met together, in order to analyze the national status, and to propose practical recommendations for implementing a standardization process on the basis of international experiences. It is recommended to exclusively express results as HbA1c percentage, using methods standardized and certified by comparison to reference methods such as those using Diabetes Control and Complications Trial (DCCT) values. Simultaneously, contacts have been established with manufacturers, and the realisation of periodic quality control surveys was encouraged.

  18. Biologie se uniekheid as substraat vir die tipies menslike funksionering

    Directory of Open Access Journals (Sweden)

    P. A. J. Ryke

    1989-03-01

    Full Text Available The biological similarities between humans and apes are great but they should not obscure the differences. Some differences are of such great consequence that man should be considered truly unique kind of organism with a marvellous plasticity of mind. All of the uniquely human traits are adaptations to the environments in which man evolved; these Include profound modifications of anatomy, physiology and behaviour. The morphological differences between man and his nearest relatives are very conspicuous. The form of the skeleton is adapted to fully erect posture and bipedal locomotion. The pelvis is broadened to provide adequate attachment for the powerful striding muscles. The transformation of the tail vertebrae is unique among the vertebrates. The joint for the neck is in the middel of the base of the skull. The hands are prehensile, with a large and strongly opposable thumb. The brain is uniquely large in proportion to the body and has a particularly large and complex cerebrum; the cerebral cortex contains the cent res for memory and complex computation. The enlarged brain requires prolonged infant dependency and high quality nutrition. Differences between humans and animals are grea tes t in the realm of behaviour: Ability to make tools (associated with bipedalism; ability to anticipate the future; development of symbolic communication (associated with expansion of cortex. Direct evidence of man's language capabilities comes form the anatomy of the modern human vocal tract. Man is the only species that succeeded in creating a truly productive language, and it is the scaffolding of human culture and civilization.

  19. Spinnen (Arachnida: Araneae) op akkers - biologie en plaagbestrijding

    NARCIS (Netherlands)

    Noordijk, J.; Helsdingen, van P.J.

    2007-01-01

    Spinnen vormen een soortenrijke groep van predatoren. In vrijwel geen terrestrisch habitattype ontbreken soorten uit deze orde. Door hun kolonisatiesnelheid en de diversiteit aan prooivangsttechnieken kunnen spinnen van groot belang zijn voor plaagbestrijding op akkers. In deze bijdrage behandelen w

  20. Biologie en bestrijding van Urocystis gladiolicola Ainsw. op gladiolen

    NARCIS (Netherlands)

    Schenk, P.K.

    1961-01-01

    Symptoms, method of infection, course of the disease, influence of environment and the control of smut in Gladiolus were described. In the first year (S1) spores adhering to scales of corms and cormels or present in the soil caused infection, generally without conspicuous symptoms. The optimum soil

  1. BIOLOGIE DE LA CONSERVATION APPLIQUEE AUX PLANTES MENACEES DES ALPES

    OpenAIRE

    Nicolè, Florence

    2005-01-01

    Through concrete examples of endangered plants chosen in the flora of the French Alps, this work presents the application of three main aspects classically used in conservation biology: the study of genetic variation, the study of reproductive performance and reproductive system and the study of population dynamics.First, we show that molecular markers are a useful tool to resolve taxonomic ambiguities and verify the status of conservation unit in the case of Potentilla delphinensis Gren. and...

  2. Sponge culture: learning from biology and ecology = Spons cultuur: leren van biologie and ecologie

    NARCIS (Netherlands)

    Caralt, de S.

    2007-01-01

    Sponges produce secondary metabolites, which play several ecological roles (McClintock & Baker 2001) such us competition for the space (Martí 2005), antifouling activity (Martin & Uriz 1993, Becerro 1994), and deterrence from predators (e.g. Becerro et al. 2003).Auswirkung von Umweltchemikalien auf die Biologie von Chironomiden und Fischen als deren Prädatoren

    OpenAIRE

    Langer-Jaesrich, Miriam

    2012-01-01

    Im Rahmen der Dissertation wurden in mehreren Teilprojekten die Auswirkungen von Umweltchemikalien auf Chironomiden als Schlüsselorganismen in aquatisch-benthischen Lebensräumen untersucht. Dabei lag der Fokus besonders auf der Erfassung von nicht-standardisierten Endpunkten und Bioindikatoren sowie auf der Bearbeitung einer weiterführenden ökologisch relevanten Fragestellung zum Räuber-Beute-Verhältnis unter Schadstoffeinfluss. Im ersten Teil der Dissertation wurde das herkömmliche Standa...

  3. Wortelonkruiden : biologie en bestrijding, een literatuuroverzicht van akkerdistel, akkerkers, knolcyperus, veenwortel, akkermunt en moerasandoorn

    NARCIS (Netherlands)

    Riemens, M.M.; Weide, van der R.Y.

    2009-01-01

    Verschillende partijen (boeren, loonwerkers, Plantenkundige Dienst) zijn gevraagd aan te geven, welke de meest pproblematische onkruidsoorten zijn. Dit in het kader van het project "Preventieve maatregelen ter beheersing van probleemonkruiden". In deze studie staan beschreven de resultaten van een l

  4. Sur la biologie du Castor du Rhône (Castor fiber L.)

    NARCIS (Netherlands)

    Urbain, Achille

    1949-01-01

    Le Castor du Rhône ( Castor fiber L.) a été particulièrement bien étudié par de nombreux auteurs. VICTOR PIRAUD ¹) a donné d’intéressants renseignements sur ses moeurs; M. P. CORDIER ²) et A. HUGUES ³) ont fait aussi une étude appronfondie de cet animal et L. GERMAND 4) a fourni une description déta

  5. « Les OGM face aux nouveaux paradigmes de la biologie »

    Directory of Open Access Journals (Sweden)

    Grosclaude Jeanne

    2009-03-01

    Full Text Available The assessment and risk management of GMOs are inherited from the paradigm of molecular biology born in the 1960s and from theories of evolutionary biology dominant in the years that saw the onset of GMOs. But these paradigms have been greatly challenged by recent advances in these disciplines : the dissolution of the concept of gene, the identification of epigenetic phenomena transmitted hereditarily, the discovery of the new continent of microRNAs, the metapopulation theory, the ability to trace gene flow over long distances, imply otherwise consider the properties of a genetically modified organism, whether or not dedicated to the dispersion in the environment. A symposium organized last february in Paris, in the framework of the ANR GMOs was designed to take the measure of these transformations of the paradigms of biology and to let clear how these results force to rethink the impacts of GMOs in the light of the new biology.

  6. Biologie statt Philosophie? Evolutionäre Kulturerklärungen und ihre Grenzen

    Science.gov (United States)

    Illies, Christian

    Vor über siebzig Jahren fand man in einer Höhle nahe Hohlenstein-Stadel, im heutigen Baden-Württemberg, eine Frau, die keiner bekannten Spezies und nicht einmal eindeutig den Hominiden zugeordnet werden konnte. Wegen ihres Aussehens wurde sie schon bald als "Löwenfrau“ bekannt (unterdessen wird sie als "Löwenmensch“ bezeichnet, da die in solchen Fragen Klarheit schaffenden Geschlechtsteile bei der Figur fehlen und in Zeiten von gender mainstreaming derartige Festlegungen gerne vermieden werden), denn sie hatte eine menschlich-aufrechte, unbehaarte Gestalt mit weiblichen Rundungen, aber zugleich eine Mähne, sowie Augen, Ohren und Schnauze eines Löwen. Eine sehr weitläufige Verwandte des Minotaurus, so schien es, und doch wesentlich älter als alle Bewohner des Olymps, denn vermutlich wurde die knapp 30 cm große Skulptur bereits in der Altsteinzeit vor etwa 32.000 Jahren aus Mammut-Elfenbein geschnitzt. Wir wissen nicht, ob sie kultischen Zwecken diente oder ein Kind mit ihr spielte, ob sie als Glücksbringer für die Jagd oder als Schamanin mit Löwenmaske verehrt und gefürchtet wurde. Aber die Löwenfrau legt nahe, dass der Mensch schon im Morgendämmern seiner Kultur über die eigene Nähe, aber auch Distanz zum Tier nachgedacht haben muss. Die Frage nach der menschlichen Selbstverortung begegnet uns in dieser Figur, und sie bestimmt viele Zeugnisse menschlichen Nachdenkens, welche uns die Altertumswissenschaften vorlegen. Mit dem Begriff "animal rationale“, wie er unter Bezug auf Aristoteles geprägt wurde, findet sie schließlich ihre klassische, für das Abendland lange Zeit maßgebliche Antwort: Der Mensch als Tier, dessen spezifisches Merkmal die Vernunftbegabtheit ist, die ihn zugleich von allen anderen Tieren abgrenzt und über sie stellt. Aber wo genau verläuft die Grenze? Und wie kann der Mensch beides zugleich sein? Die aristotelische Definition beantwortet diese Fragen nach der Doppelnatur nicht, sondern erhebt das offene Rätsel gleichsam zur Wesensbestimmung des Menschen.

  7. Erste Nachweise sowie Kenntnisse zur Biologie von Cyclosa oculata (Araneae: Araneidae in der Schweiz

    Directory of Open Access Journals (Sweden)

    Zschokke, Samuel

    2007-06-01

    Full Text Available The orb-web spider Cyclosa oculata (Walckenaer, 1802 was found at eleven localities in north-western Switzerland. All records were from wildflower strips ("Buntbrachen" with a relatively high proportion of dried vegetation from the previous year, a relatively low vegetation height and a low proportion of grasses in the vegetation. C. oculata built its vertical orb-web near the ground, deep in the vegetation. Among ecribellate orb-web spiders in Central Europe, C. oculata is unique because it sometimes builds rudimentary webs on which it stays, because it builds its cocoons into the web, and because its stabilimentum is long-lasting and consists largely of debris. Based on our observations, we deduce that the stabilimentum of C. oculata serves as camouflage.

  8. Wortelonkruiden : biologie en bestrijding, een literatuuroverzicht van akkerdistel, akkerkers, knolcyperus, veenwortel, akkermunt en moerasandoorn

    NARCIS (Netherlands)

    Riemens, M.M.; Weide, van der R.Y.

    2009-01-01

    Verschillende partijen (boeren, loonwerkers, Plantenkundige Dienst) zijn gevraagd aan te geven, welke de meest pproblematische onkruidsoorten zijn. Dit in het kader van het project "Preventieve maatregelen ter beheersing van probleemonkruiden". In deze studie staan beschreven de resultaten van een l

  9. Modélisation probabiliste en biologie cellulaire et moléculaire

    OpenAIRE

    Yvinec, Romain

    2012-01-01

    The importance of stochasticity in gene expression has been widely shown recently. Wewill first review the most important related work to motivate mathematical models thattakes into account stochastic effects. Then, we will study two particular models where stochasticityinduce interesting behavior, in accordance with experimental results : a bursting dynamic in a self-regulating gene expression model ; and the emergence of heterogeneityfrom a homogeneous pool of protein by post-translational ...

  10. Modélisation probabiliste en biologie moléculaire et cellulaire

    OpenAIRE

    Yvinec, Romain

    2012-01-01

    The importance of stochasticity in gene expression has been widely shown recently. We will first review the most important related work to motivate mathematical models that takes into account stochastic effects. Then, we will study two particular models where stochasticity induce interesting behavior, in accordance with experimental results: a bursting dynamic in a self-regulating gene expression model; and the emergence of heterogeneity from a homogeneous pool of protein by post-translationa...

  11. Modélisation probabiliste en biologie cellulaire et moléculaire

    OpenAIRE

    Yvinec, Romain

    2012-01-01

    De nombreux travaux récents ont démontré l'importance de la stochasticité dans l'expression des gènes à différentes échelles. On passera tout d'abord en revue les principaux résultats expérimentaux pour motiver l'étude de modèles mathématiques prenant en compte des effets aléatoires. On étudiera ensuite deux modèles particuliers où les effets aléatoires induisent des comportements intéressants, en lien avec des résultats expérimentaux: une dynamique intermittente dans un modèle d'auto-régulat...

  12. Nasopharyngeal carcinomas: from biology to clinic; Les carcinomes du nasopharynx: de la biologie a la clinique

    Energy Technology Data Exchange (ETDEWEB)

    Rivera, S.; Maingon, P. [Centre Georges-Francois-Leclerc, Dept. de Radiotherapie, 21 - Dijon (France); Keryer, C.; Busson, P. [Institut Gustave-Roussy, CNRS/UMR 8126, 94 - Villejuif (France)

    2005-02-15

    Nasopharyngeal carcinomas (NPC) are very different from other head and neck cancers because of their specific multi-factorial etiology and their geographic distribution. Epstein-Barr Virus (EBV) is implicated in onco-genesis of NPC in association with genetic alterations such as inactivation of the p16/Ink4, p19/ARF, RASSFI or Blu genes. Tumoral tissues include a very abundant characteristic lymphoid infiltrate. Inflammatory cytokines are produced by both malignant and infiltrating cells. There is no efficient immune response against the tumor. On the opposite, infiltrating lymphocytes might play a role in tumor development. Serological methods and detection of circulating viral DNA are expected to become useful for early detection of relapse and on a longer term for primary screening. NPC are often diagnosed at a late stage because patients may remain asymptomatic for a long time. Computed tomography (CT scan) and magnetic resonance imaging (MRI) are complementary for the initial evaluation. Positron emission tomography (PET) is efficient for the evaluation of treatment efficiency and detection of relapses. Treatment is based on radiotherapy and chemotherapy. Their optimal use needs to be evaluated by phase III trials but positive results have been obtained by concomitant association of radiotherapy and chemotherapy. Targeted therapies are being studied with strategies based on disruption of viral latency, use of replicative adeno-viruses or anti-tumor vaccination. (author)

  13. Biologie vzácných druhů mechorostů

    OpenAIRE

    PAPÁČKOVÁ, Dagmar

    2009-01-01

    Most of studies found that rare species have narrow habitat requirements, restricted dispersal and poor competition capabilities. I review these patterns of some rare bryophytes species as a causes of their rarity and I assess human activity leading to decrease population of some rare bryophytes. Finally I describe some restoration managements to save these populations of some rare species.

  14. Biologie des Geruchs: Die Bedeutung von Pheromonen für Verhalten und Reproduktion

    Directory of Open Access Journals (Sweden)

    Atzmüller M

    2000-01-01

    Full Text Available Dieser Artikel geht der Frage nach dem Vorkommen und der Wirkung von Pheromonen beim Menschen nach. Es wird der Status quo der Geruchsforschung aufgezeigt und ein Überblick über die Voraussetzungen der Geruchskommunikation geboten. Über Beispiele aus dem Tierreich wird zu ihrem Vorkommen und ihrer Bedeutung beim Menschen geführt. So hat sich in den letzten Jahren gezeigt, daß besonders die Geruchsstoffe aus dem Schweiß das Potential besitzen, menschliches Verhalten nachweislich zu beeinflussen. Darüber hinaus zeigt sich, daß auch die menschliche Reproduktion dem Einfluß von Pheromonen zu unterliegen scheint. Die Bedeutung der Geruchskommunikation beim Menschen wird größtenteils noch immer unterschätzt, obwohl sie durchaus das Potential für zukünftigen medizinischen Einsatz zu bergen scheint.

  15. Sur la biologie du Castor du Rhône (Castor fiber L.)

    NARCIS (Netherlands)

    Urbain, Achille

    1949-01-01

    Le Castor du Rhône ( Castor fiber L.) a été particulièrement bien étudié par de nombreux auteurs. VICTOR PIRAUD ¹) a donné d’intéressants renseignements sur ses moeurs; M. P. CORDIER ²) et A. HUGUES ³) ont fait aussi une étude appronfondie de cet animal et L. GERMAND 4) a fourni une description

  16. Sponge culture: learning from biology and ecology = Spons cultuur: leren van biologie and ecologie

    NARCIS (Netherlands)

    Caralt, de S.

    2007-01-01

    Sponges produce secondary metabolites, which play several ecological roles (McClintock & Baker 2001) such us competition for the space (Martí 2005), antifouling activity (Martin & Uriz 1993, Becerro 1994), and deterrence from predators (e.g. Becerro et al. 2003).

  17. Radioactive indicators in biology and their medical applications; Indicateurs radioactifs en biologie et leurs applications medicales

    Energy Technology Data Exchange (ETDEWEB)

    Morel, F

    1950-12-01

    This talk was given at the society of promotion of the national industry on December 1, 1949. The report is a pre-print of an article published in L'Industrie Nationale no.2 (1950). It presents the state-of-the-art of the use of artificial radioisotopes in biology and medicine: 1 - definitions (isotopes, decay, radiation emission); 2 - modalities of the use of radioisotopes in biology: basic instrumentation (Geiger-Mueller counter, counting techniques, photography, auto-histo-radiography); 3 - applications in physiology (digestive absorption, excretion, vascular exchanges, tracer techniques) and biochemistry (metabolism, thyroxine synthesis and fixation indicators, tracer techniques for drugs); 4 - radiotherapy, internal and external irradiation. (J.S.)

  18. Sponge culture: learning from biology and ecology = Spons cultuur: leren van biologie and ecologie

    NARCIS (Netherlands)

    Caralt, de S.

    2007-01-01

    Sponges produce secondary metabolites, which play several ecological roles (McClintock & Baker 2001) such us competition for the space (Martí 2005), antifouling activity (Martin & Uriz 1993, Becerro 1994), and deterrence from predators (e.g. Becerro et al. 2003).Nuclear biological studies in France; Les etudes de biologie nucleaires en France

    Energy Technology Data Exchange (ETDEWEB)

    Coursaget, J. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    On the occasion of a colloquium on radiobiological research programmes, a number of documents dealing with French accomplishments and projects in this field were collected together. We felt that it would be useful to assemble these papers in one report; although they are brief and leave gaps to be filled in, they provide certain data, give an overall view of the situation, and can also suggest a rough plan for the general policy to adopt in the field of 'nuclear' biological research; i.e. research based on the nuclear tracer method or devoted to the action of ionising radiations. (author) [French] Un colloque sur les programmes de recherche en radiobiologie nous a donne l'occasion de reunir des documents sur les realisations et les projets francais dans ce domaine. Il nous a semble utile de reunir en un rapport l'ensemble de ces documents, qui, malgre leur brievete et malgre les lacunes qu'ils comportent, donnent un certain nombre d'informations, permettent une vue d'ensemble et peuvent dessiner aussi l'ebauche d'une politique coherente en matiere de recherches biologiques 'nucleaires', c'est-a-dire de recherches basees sur la methode des indicateurs nucleaires ou consacrees a l'action des rayonnements ionisants. (auteur)

  1. Krebstiere (Crustacea) – Biologie, Vorkommen, Haltung und Erkrankungen, sowie ihre Bedeutung als Zootierobjekte und Lebensmittelressourcen : eine Literaturstudie

    OpenAIRE

    Walther, Marc

    2008-01-01

    Crustaceen stellen nicht nur eine biologisch interessante Tiergruppe dar, sondern erlangen aufgrund ihrer Haltung in Zoos und durch ihre Nutzung als wichtige Lebensmittelquelle ein immer größer werdendes Interesse. Gerade in den letzen Jahren gab es eine enorme Informationsflut über Erkrankungen bei Crustaceen. Dies wurde als Anlass genommen, das heutige Wissen in einer Abhandlung zusammenzufassen. Die Literaturstudie wird durch eine systematische zoologische und lebensmitterel...

  2. Reproduction et révolution normative : mariage, monogamie et biologie sous le IIIe Reich

    OpenAIRE

    Chapoutot, Johann

    2013-01-01

    Tout comme la France des Croix de bois, l’Allemagne a eu ses cauchemars oliganthropiques : la pire conséquence de la Grande Guerre n’est, pour de larges cercles conservateurs et nationalistes allemands, pas la défaite, ni même le traité de Versailles, mais la saignée démographique de quatre à cinq ans de combats, de blocus, de famine, puis de grippe espagnole. Une guerre est une confrontation que l’on peut rejouer, un traité peut être renégocié. La structure d’une pyramide des âges est au con...

  3. BIOLOGIE DE REPRODUCTION DE LA PIE-GRIÈCHE MÉRIDIONALE LANIUS MERIDIONALIS ALGERIENSIS EN MITIDJA

    Directory of Open Access Journals (Sweden)

    Ahmed Taibi

    2016-06-01

    Full Text Available Taibi Ahmed, Abdessalam Manaa, Frédéric Labouyrie and Salaheddine Doumandji. 2016. Reproduction biology of the southern grey shrike Lanius meridionalis algeriensis in Mitidja (Algeria. Lebanese Science Journal, 17(1: 1-8. In the eastern part of Mitidja (northern Algeria, a research study area was selected in order to study the reproduction of the southern grey shrike Lanius meridionalis algeriensis. The study lasted 3 years from 2007 to 2009. The nests were placed preferably on Olive-trees (Olea europeae and Filaos (Casuarina sp., at a medium height of 1.8 m. They have on average an external diameter of 18.7 cm, an internal diameter of 8.5 cm and height of 8.7 cm. The eggs had an oval form and a medium weight between 4.9 and 6.1 grs. The incubation period was 11 days and the fledged young were raised during 16.8 days on average.

  4. Une approche de modélisation de biologie des systèmes sur la spondylarthrite

    OpenAIRE

    Chaplais, Emmanuel

    2015-01-01

    Spondyloarthritis is a frequent chronic inflammatory rheumatism, with a prevalence of 0.43 % in France. This disease presents axial skeleton injuries, but also on peripheral joints, and can results in a total spinal and sacro-iliac motility loss. Extra-articular features including uveitis, psoriasis and inflammatory bowel disease are frequent. Current SpA treatments are only symptomatic, relieving inflammatory symptoms. SpA etiology is largely multifactorial with a genetic component dominated...

  5. Charakterisierung der DNA-Replikation in genetisch modifizierten Escherichia coli Stämmen durch neue Methoden der Synthetischen Biologie

    OpenAIRE

    Milbredt, Sarah; Waldminghaus, Torsten

    2016-01-01

    Eukaryoten und Prokaryoten unterscheiden sich in der Organisation ihrer Genome. Prokaryoten tragen mehrheitlich ein zirkuläres Chromosom, welches von einem Replikationsursprung repliziert wird. Das eukaryotische Genom hingegen umfasst mehrere lineare Chromosomen, die mehr als einen Replikationsursprung enthalten. In wie weit die prokaryotische Genomorganisation der eukaryotischen angepasst werden kann, ist eine spannende ...

  6. Biologie Moléculaire et Phylogenèse des Lémuriformes (Primates de Madagascar)

    OpenAIRE

    2001-01-01

    Membres du jury: Pr. Y. RUMPLER Pr. P. DARLU Pr. R. ALBIGNAC Dr. A. HANAUER; Molecular biology and Lemuriformes (Malagasy Primates) phylogeny In this study most of the species included in the Lemuridae (Eulemur, Hapalemur, Varecia), Indriidae (Indri, Propithecus, Avahi), Lepilemuridae, Cheirogaleidae (Cheirogaleus, Microcebus, Mirza) and Daubentonia are used, as well as a sub-fossile (Megaladapis edwardsi) and two Tupaia species. Mitochondrial sequences from a cytochrome b fragment (357 bp) a...

  7. Biologie de la reproduction du Cyprinidae, Barbus callensis dans le lac de barrage Hamiz (Algérie

    Directory of Open Access Journals (Sweden)

    Ould Rouis, S.

    2012-01-01

    Full Text Available Reproductive Biology of the Cyprinidae, Barbus callensis in an Algerian Dam. The freshwater fish, Barbus callensis (Valenciennes, 1842 was studied from 2005 to 2007 for the first time in Hamiz dam. This species endemic of North African continent is widely spread in the rivers of Algeria. This reservoir is situated in Boumerdes 35 km southeast of Algiers. During these three years, the monthly sampling was carried out by trammel nets, fishing near the dike during one night. At the same time, the fry was captured with a transparent plastic bottle baited with breadcrumbs put down near the lakeshore. The monthly follow-up of the gonadosomatic ratio (RGS reveals that the spawning period occurred between April and May. The evolution of the condition factor (K shows low seasonal variations. However, a lower value appears in spring when the temperature increases and the breeding begins. The sex ratio is higher for the adult females (1:2.8, more than 26 cm. The first sexual maturity size (L50 is lower for males (19.6 cm than for females (27.7 cm.

  8. Selection of maintaining, method for keeping of biologial purity, patternship and health, regarding viruses infection of distinguished potato breeding lines

    Directory of Open Access Journals (Sweden)

    Luiza MIKE

    2008-05-01

    Full Text Available A large number of potato varieties and distinguished breeding lines disappeared as an effect of nonfavourable climatically conditions and especially by viruses diseases, as well as other biological and viruses degeneration. To avoid the negative effect of degeneration on potato varieties and distinguished breeding lines, the method of selection for maintaining and multiplication of potato is applying in Romania in the frame of National Center for Maintaining of potato varieties and distinguished breeding lines Apa Rosie, Covasna County, which belong to the Station for Research and Development of Potato, Targu Secuiesc, Covasna County.In this center are maintained and multiplied all distinguished varieties and breeding centers from Romania (National Institute for research and Development of Potato and Sugar beet Brasov, Research and Development Station for Agriculture Suceava, Research and Development Station for Potato Targu Secuiesc, Research and development Station for Potato Miercurea Ciuc.Using the method of selection for maintaining it is possible an early identification of somatic mutations, disease (especially viruses infection by visual elimination or by serological testing.The viruses’ infection of potato leads to disturbed the metabolism of plants and produces anatomical – morphological alters as: mosaic, crinkle, rolling, browning of leaves and plants deformation.The disturbing of plant metabolism has as negative effect the reduction of vegetation period, decreasing the yield capacity, depreciation of physical and chemical quality of tubers.The genetically complex structure of cultivated potato (2n = 4x = 48 and strong segregation of long – expected characters in the obtained future progeny by sexual hybridization, complicated many times by nonfavourable linkage, are the backgrounds for initiation of maintain selection.

  9. Recontextualiseren van het concept biodiversiteit : Het ontwikkelen van een onderwijsleerstrategie voor het recontextualiseren van het concept biodiversiteit in de bovenbouw biologie havo en vwo

    NARCIS (Netherlands)

    van Weelie, D.

    2014-01-01

    This thesis reports on a design-research study on the development of a teaching-and-learning strategy for the flexible use of the concept of biodiversity in new contexts in upper secondary biology education. The notions of ‘concept’, ‘context’ and ‘flexible use of a concept’ by ‘recontextualising’ t

  10. Hnízdní biologie plameňáka růžového (Phoenicopterus ruber) v zoo Ohrada

    OpenAIRE

    ŠENKÝŘOVÁ, Marie

    2013-01-01

    Flamingos belong to the Phoenicopteridae family. They are occurred from India, through southern Europe to South Africa, flamingo cover Caribbean and southern half of South America at the Western Hemisphere. They consist mainly monogamous couples and their nesting is highly synchronized. They lay usually one egg, even if there are the records about laying two eggs. Incubation of the Greater flamingo (Phoenicopterus ruber) takes 26-32 days. The thesis was performed in Zoo Ohrada Hluboká nad Vlt...

  11. Biologie, výskyt a regulace plevelů v pěstovaných plodinách

    OpenAIRE

    Václav NOVOTNÝ

    2014-01-01

    Weeds currently represent a constant risk to the crop plants. They are able to either suppress the development of a crop plant in the initial period of its growth or to hinder and even make the harvest impossible due to its stand density at the end of the vegetative phase before the harvest. Perennial weeds rank among very noxious weeds. They are highly resistant and able to adapt to the used control measures. The character of the crop plants itself and the applied agronomic practices determi...

  12. Mass spectrometry. Environment, biology, oenology, medicine, geology, chemistry, archaeology, mechanisms; Spectrometrie de masse. Environnement, biologie, oenologie, medecine, geologie, chimie, archeologie, mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This document provides the papers (communications and posters) presented at the 16. French days of mass spectrometry, held September 6-9, 1999 in Nancy, France. 7 papers are interesting for the ETDE database and are analyzed separately. (O.M.)

  13. Mass spectrometry. Environment, biology, oenology, medicine, geology, chemistry, archaeology, mechanisms; Spectrometrie de masse. Environnement, biologie, oenologie, medecine, geologie, chimie, archeologie, mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This document provides the papers (communications and posters) presented at the 16. French days of mass spectrometry, held September 6-9, 1999 in Nancy, France. 5 papers are interesting for the INIS database and are analyzed separately. (O.M.)

  14. Recontextualiseren van het concept biodiversiteit : Het ontwikkelen van een onderwijsleerstrategie voor het recontextualiseren van het concept biodiversiteit in de bovenbouw biologie havo en vwo

    NARCIS (Netherlands)

    van Weelie, D.

    2014-01-01

    This thesis reports on a design-research study on the development of a teaching-and-learning strategy for the flexible use of the concept of biodiversity in new contexts in upper secondary biology education. The notions of ‘concept’, ‘context’ and ‘flexible use of a concept’ by ‘recontextualising’ t

  15. Recontextualiseren van het concept biodiversiteit : Het ontwikkelen van een onderwijsleerstrategie voor het recontextualiseren van het concept biodiversiteit in de bovenbouw biologie havo en vwo

    NARCIS (Netherlands)

    van Weelie, D.

    2014-01-01

    This thesis reports on a design-research study on the development of a teaching-and-learning strategy for the flexible use of the concept of biodiversity in new contexts in upper secondary biology education. The notions of ‘concept’, ‘context’ and ‘flexible use of a concept’ by ‘recontextualising’

  16. Aedes albopictus, vecteur des virus du chikungunya et de la dengue à la Réunion : biologie et contrôle

    Directory of Open Access Journals (Sweden)

    Delatte H.

    2008-03-01

    Full Text Available Les virus du chikungunya (CHIKV et de la dengue (DENV sont transmis par des moustiques du genre Aedes. La dengue est considérée comme l’arbovirose la plus importante dans le monde. Le chikungunya, connu d’Afrique continentale et d’Asie, et jusqu’à présent peu étudié, a été de 2004 à 2007 à l’origine de graves épidémies dans l’Océan Indien (OI, en Inde et en Afrique centrale, générant d’importants problèmes de santé publique et économiques. La récente épidémie dans le sud-ouest de l’Océan Indien (SOOI a mis en exergue le caractère explosif de son émergence ainsi que la morbidité et la mortalité qui lui ont été associées, jusque-là sans précédent. Les deux vecteurs majeurs impliqués dans la transmission de ces arbovirus dans la zone OI sont Aedes aegypti et Aedes albopictus, ce dernier étant considéré comme le vecteur principal dans la majorité des îles de la zone. Dans l’île de la Réunion, où Ae. albopictus est le vecteur du CHIKV, la lutte anti-larvaire (téméphos puis Bacillus thuringiensis, anti-adulte (fénitrothion, puis deltaméthrine, ainsi qu’une protection individuelle et communautaire (utilisation de répulsifs, destruction des gîtes larvaires autour des habitations ont été réalisées depuis 2006 et tout au long de la crise sanitaire. Afin de prévenir de telles épidémies, un plan de prévention des arboviroses est en cours de réalisation. Il devra permettre d’intervenir plus rapidement dès la réception des premiers signaux d’alerte, et d’adapter la réponse en fonction du virus et de son vecteur.

  17. Aedes albopictus, vecteur des virus du chikungunya et de la dengue à la Réunion : biologie et contrôle

    OpenAIRE

    Delatte H.; Paupy C.; Dehecq J.S.; Thiria J.; Failloux A.B.; Fontenille D.

    2008-01-01

    Les virus du chikungunya (CHIKV) et de la dengue (DENV) sont transmis par des moustiques du genre Aedes. La dengue est considérée comme l’arbovirose la plus importante dans le monde. Le chikungunya, connu d’Afrique continentale et d’Asie, et jusqu’à présent peu étudié, a été de 2004 à 2007 à l’origine de graves épidémies dans l’Océan Indien (OI), en Inde et en Afrique centrale, générant d’importants problèmes de santé publique et économiques. La récente épidémie dans le sud-ouest de l’Océan I...

  18. Développement de nouveaux chromophores basés sur le groupement tricyanofurane pour différentes applications en biologie

    OpenAIRE

    Ipuy, Martin

    2014-01-01

    Tricyanofuran is a strong electro-withdrawing group due to its three conjugated nitrile groups. This electronic characteristic was used to synthetize new fluorescent probes for biological imaging: small molecules owing a strong dipolar behavior that strongly shifts the fluorescence to the red. A first application of this kind of molecules is intracellular pH detection with a phenol moiety conjugated to the tricyanofuran. Thanks to a convenient retro-synthesis, a large family was developed dis...

  19. Etude des caractéristiques botaniques, agronomiques et de la biologie florale du melon africain (Cucumis melo var. L. agrestis Naudin, Cucurbitaceae)

    OpenAIRE

    Baudoin JP.; Gnamien GY.; Zoro Bi AI.; Kouonon LC.; Djè Y.

    2006-01-01

    Study of botanic, agronomic characters and fl oral biology of African melon (Cucumis melo L. var. agrestis Naudin, Cucurbitaceae). African melon, Cucumis melo var. agrestis, is a cultivated crop for which dried seeds are used in preparation of sauce pistachio, a valuable food in Côte dʼIvoire. Few studies are concerned with this crop as compared to melon species cultivated in temperate countries. Agronomic and morphological characteristics of C. melo var. agrestis are studied based on eight c...

  20. Etude des caractéristiques botaniques, agronomiques et de la biologie florale du melon africain (Cucumis melo var. L. agrestis Naudin, Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Baudoin JP.

    2006-01-01

    Full Text Available Study of botanic, agronomic characters and fl oral biology of African melon (Cucumis melo L. var. agrestis Naudin, Cucurbitaceae. African melon, Cucumis melo var. agrestis, is a cultivated crop for which dried seeds are used in preparation of sauce pistachio, a valuable food in Côte dʼIvoire. Few studies are concerned with this crop as compared to melon species cultivated in temperate countries. Agronomic and morphological characteristics of C. melo var. agrestis are studied based on eight characters: germination rate, emergence time, date of fl owering, duration of life cycle, weight of mature berries, mean number of seeds per berry, weight of 100 seeds and seeds shape. Floral biology and mating system are studied on the basis of 19 parameters. Results of these studies showed that C. melo var. agrestis has a life cycle duration of 110 to 150 days varying with seasons. The mean number of berries per plant is variable (5 to 15 and the percentage of seeds per berry is low (6,83%. African melon is andromonoecious with a phenological interval between male and hermaphrodite fl owers occurrence. The pollen grains of hermaphrodite fl owers are viable and the stigmata are mature before fl owers are opening. The implications of fl oral biology on the mating system are discussed in view of yield breeding and study of gene fl ow among individuals on fields.

  1. Ecologie et biologie de la conservation des métallophytes: le cas de Crepidorhopalon perenniset C. tenuis (Scrophulariaceae) des sols cupro-cobaltifères du Katanga

    OpenAIRE

    Faucon, Michel-Pierre

    2009-01-01

    La province du Katanga est connue pour ses affleurements naturels de roches riches en cuivre et en cobalt. Plus d’une centaine de « collines de cuivre », isolées géographiquement et écologiquement possèdent une flore très originale qui comprend plus de 600 espèces dont 32 endémiques. Les métallophytes du Katanga sont des plantes fascinantes aux points de vue écologique, biogéographique, physiologique et évolutif. Elles restent très peu étudiées et leur conservation est très problématique comp...

  2. Medical and biological utilization of radioelements in France; Utilisation des radioelements en france dans le domaine de la medecine et de la biologie

    Energy Technology Data Exchange (ETDEWEB)

    Coursaget, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    The development of the research about stable and radioactive isotopes uses in biology and medicine started in France in the early years after the second World War. Close collaboration with United States led to the training of an hundred of French medical researchers in US research laboratories, twenty of whom were specifically trained about tracers uses and techniques. Since 1950, the C.N.R.S. and C.E.A. have collaborated to train French researchers to the isotopes methods, interpretation difficulties and precaution measures about radioisotopes manipulations. In the early fifties, the CEA started the radioisotopes production for medical and biology research and applications uses. The clinical uses of isotopes are presented in two main applications: diagnosis uses such as {sup 131}I for diagnosis or functional studies of thyroid gland and therapeutic treatments such as {sup 32}P for leukaemia and other cancer treatments. In a second part, the main studies subjects of basic and applied research are described: physiological and biological studies of the absorption, diffusion and distribution of different molecules as well as membrane permeability in biological systems for medicine and agronomy applications, studies of the incorporation of labelled compounds in biological and organic systems by exchange or synthesis ({sup 32}P is used for renewal studies of the osseous tissue), studies of the mechanism of biochemical reactions ({sup 14}C, {sup 15}N and {sup 35}S are the most used radionuclides) and endocrinology research, in particular, biochemical studies of the thyroid hormones. All these researches and applications encountered financial and delay in radioisotope production for which the CEA provided most of the labelled compounds at reasonable prices. The large development of isotopes applications in diagnosis, therapeutic as well as basic and applied research, leads to increase radionuclides demand and production delays. It discussed the different solutions to facilitate the diffusion and the use of radioisotopes for smaller laboratories structures by intensifying specific training to researchers and increasing the material and human resources. A European collaboration is also considered to facilitate the link between the medicine and biology researchers and the organist chemists who synthesize labelled compounds. (M.P.)

  3. Influence des matières végétales et des engrais NPK sur la biologie de Aedes aegypti (Diptera : Culicidae

    Directory of Open Access Journals (Sweden)

    Darriet F.

    2010-06-01

    Full Text Available Dans cette étude de laboratoire, les auteurs ont mesuré sur des femelles gravides de Aedes aegypti, l’attractivité à la ponte de milieux aqueux contenant un engrais NPK, de la matière végétale (MV et un mélange composé de MV+NPK. Tandis que les analyses physico-chimiques ont permis d’identifier puis de doser les constituants de chaque milieu, le suivi des larves et la pesée des femelles émergentes nous ont renseigné sur l’impact des composés minéraux et organiques sur le développement des moustiques. Sur les 23 jours qu’a duré l’expérience, la solution NPK est restée aussi attractive que le mélange MV+NPK sans toutefois pouvoir assurer le développement des larves. L’infusion MV a révélé une attractivité à la ponte moins importante, mais elle a apporté aux larves de moustiques les substances organiques dont la solution NPK était dépourvue. Enfin le mélange MV+NPK a attiré les femelles à la ponte tout en assurant pleinement la croissance des larves de Ae. aegypti. Alors que les analyses physico-chimiques de NPK ont révélé une composition essentiellement minérale (NH4++NO3–+P+K et celles de MV de fortes concentrations en carbone et en azote organiques, le mélange MV+NPK s’est distingué par une composition mixte organique et minérale qui a favorisé la prolifération des bactéries et le développement des larves de moustiques. Ce sont des observations importantes qui pourraient aider à la fabrication de pièges à la fois attractifs et létaux (NPK+larvicide et dont les fonctions seraient de piéger les femelles gravides à la recherche d’un lieu de ponte et de tuer les larves à l’éclosion des oeufs.

  4. General solutions to multiple testing problems. Translation of "Sonnemann, E. (1982). Allgemeine Lösungen multipler Test probleme. EDV in Medizin und Biologie 13(4), 120-128".

    Science.gov (United States)

    Sonnemann, Eckart

    2008-10-01

    The introduction of sequentially rejective multiple test procedures (Einot and Gabriel, 1975; Naik, 1975; Holm, 1977; Holm, 1979) has caused considerable progress in the theory of multiple comparisons. Emphasizing the closure of multiple tests we give a survey of the general theory and its recent results in applications. Some new applications are given including a discussion of the connection with the theory of confidence regions.

  5. Facilities for external radiation accessible for investigation on biological studies - progress report may 2004; Les installations d'irradiation externe accessibles aux etudes de biologie - etat d'avancement mai 2004

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard-Lecanu, E. [CEA Fontenay aux Roses (DSV/Carmin), 92 (France); Authier, N.; Verrey, B. [CEA Valduc, Dept. Recherche sur les Materiaux Nucleaires, 21 - Is-sur-Tille (France); Bailly, I. [CEA Bruyeres le Chatel, 91 (France). Dept. de Physique Theorique et Appliquee; Baldacchino, G.; Pin, S.; Pommeret, S.; Renault, J.Ph. [CEA Saclay, Dept. de Recherche sur Etat Condense, les Atomes et les Molecules, 91 - Gif sur Yvette (France); Bordy, J.M. [CEA Saclay, Dir. de la Recherche Technologique (DRT/DETECS/LNHB/LMD), 91 - Gif sur Yvette (France); Coffigny, H. [CEA Fontenay aux Roses, Dept. de Radiobiologie et de Radiopathologie, 92 (France); Cortela, L. [CEA Grenoble, ARC-Nucleart, 38 (France); Duval, D. [CEA Saclay, Schering - CIS bio International, 91 - Gif sur Yvette (France); Leplat, J.J. [CEA Saclay (DSV/DRR/LREG), 91 - Gif sur Yvette (France); Poncy, J.L. [CEA Fontenay aux Roses (DSV/DRR/SRCA), 92 (France); Testard, I. [CEA Caen (DSV/DRR/LRO-LARIA), 14 - Caen (France); Thuret, J.Y. [CEA Saclay (DSV/DBJC/SBGM), 91 - Gif sur Yvette (France)

    2004-07-01

    The Life Science Division of the Atomic Energy Commission is making an inventory of the various radiation sources accessible for investigation on the biological effects of ionizing radiation. In this field, a wide range of studies is being carried out at the Life Science Division, attempting to characterize the kind of lesions with their early biological consequences (on the various cell compartments) and their late biological consequences (deterministic or stochastic effects), in relation to the radiation type and dose, especially at low doses. Several experimental models are available: plants, bacteria, eukaryotic cells from yeast up to mammalian cells and in vivo studies, mostly on rodents, in order to characterize the somatic late effects and the hereditary effects. Due to the significant cost of these facilities, also to their specific properties (nature of the radiation, dose and dose rate, possible accuracy of the irradiation at the molecular level), the closeness is no longer the only criteria for biologists to make a choice. The current evolution is to set up irradiation infrastructures combining ionizing radiation sources themselves and specific tools dedicated to biological studies: cell or molecular biology laboratories, animal facilities. The purpose, in this new frame, is to provide biologists with the most suitable facilities, and, if possible, to change these facilities according to requirements in radiobiology. In this report, the basics of interactions of ionizing radiation with biological tissues are briefly introduced, followed by a presentation of some of the facilities available at the CEA for radiobiological studies. This panorama is not a comprehensive one, new data will be included as they advance, whether reporting existing facilities or if a new one is developed. (authors)

  6. Biologie, éco-éthologie et dynamique des populations du scolyte des grains de café, Hypothenemus hampei Ferr. (Coleoptera, Scolytidae), en Nouvelle-Calédonie

    OpenAIRE

    Giordanengo, Philippe

    1992-01-01

    Séminivore strictement monophage, #Hypothenemus hampei$ Ferr. (#Coleoptera, Scolytidae$) est l'ennemi majeur de la caféiculture en Nouvelle-Calédonie. L'accouplement qui a lieu dans la graine d'émergence est facilité par l'intervention de signaux, de nature vraisemblablement olfactive, émis par les femelles. Environ douze jours après leur émergence, ces dernières quittent leur baie d'éclosion à l'issue d'une inversion de leurs comportements phototropique et thigmotactique. La dispersion qui s...

  7. External irradiation facilities open for biological studies - progress in july 2005; Les installations d'irradiation externe accessibles aux etudes de biologie etat d'avancement juillet 2005

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard-Lecanu, E. [CEA Fontenay aux Roses (DSV/Carmin), 92 (France); Authier, N.; Verrey, B. [CEA Valduc, Dept. Recherche sur les Materiaux Nucleaires, 21 - Is-sur-Tille (France); Bailly, I. [CEA Bruyeres le Chatel, 91 (France). Dept. de Physique Theorique et Appliquee; Baldacchino, G.; Pin, S.; Pommeret, S.; Renault, J.Ph. [CEA Saclay, Dept. de Recherche sur Etat Condense, les Atomes et les Molecules, 91 - Gif sur Yvette (France); Bordy, J.M. [CEA Saclay, Dir. de la Recherche Technologique (DRT/DETECS/LNHB/LMD), 91 - Gif sur Yvette (France); Coffigny, H. [CEA Fontenay aux Roses, Dept. de Radiobiologie et de Radiopathologie, 92 (France); Cortela, L. [CEA Grenoble, ARC-Nucleart, 38 (France); Duval, D. [CEA Saclay, Schering - CIS bio International, 91 - Gif sur Yvette (France); Leplat, J.J. [CEA Saclay (DSV/DRR/LREG), 91 - Gif sur Yvette (France); Poncy, J.L. [CEA Fontenay aux Roses (DSV/DRR/SRCA), 92 (France); Testard, I. [CEA Caen (DSV/DRR/LRO-LARIA), 14 - Caen (France); Thuret, J.Y. [CEA Saclay (DSV/DBJC/SBGM), 91 - Gif sur Yvette (France)

    2005-07-01

    The Life Science Division of the Atomic Energy Commission is making an inventory of the various radiation sources accessible for investigation on the biological effects of ionizing radiation. In this field, a wide range of studies is being carried out at the Life Science Division, attempting to characterize the kind of lesions with their early biological consequences (on the various cell compartments) and their late biological consequences (deterministic or stochastic effects), in relation to the radiation type and dose, especially at low doses. Several experimental models are available: plants, bacteria, eukaryotic cells from yeast up to mammalian cells and in vivo studies, mostly on rodents, in order to characterize the somatic late effects and the hereditary effects. Due to the significant cost of these facilities, also to their specific properties (nature of the radiation, dose and dose rate, possible accuracy of the irradiation at the molecular level), the closeness is no longer the only criteria for biologists to make a choice. The current evolution is to set up irradiation infrastructures combining ionizing radiation sources themselves and specific tools dedicated to biological studies: cell or molecular biology laboratories, animal facilities. The purpose, in this new frame, is to provide biologists with the most suitable facilities, and, if possible, to change these facilities according to requirements in radiobiology. In this report, the basics of interactions of ionizing radiation with biological tissues are briefly introduced, followed by a presentation of some of the facilities available for radiobiological studies especially at CEA. This panorama is not a comprehensive one, new data will be included as they advance, whether reporting existing facilities or if a new one is developed. (authors)

  8. Biologie de la reproduction d'un poisson chat Africain Euchilichthys guentheri (Schilthuis, 1891 (Mochokidae, Siluriformes au Pool Malebo, Fleuve Congo (République Démocratique du Congo

    Directory of Open Access Journals (Sweden)

    Tembeni, JM.

    2014-01-01

    Full Text Available Reproductive Biology of the African Catfish Euchilichthys guentheri (Schilthius, 1891 (Mochokidae, Siluriformes of Malebo Pool, Congo River (Democratic Republic of Congo. In the Malebo Pool of the Congo River in DRC, Euchilichthys guentheri (Schilthuis, 1891 a highly consumed fish during the dry season, undergoes a strong pressure of fishing whereas one does not have knowledge on his reproductive biology. Reproductive parameters of E. guentheri were determined to ensure rational and sustainable management of the resource at Malebo Pool. Fish were collected monthly between January and December 2009, and subsequently from February to December 2011. The whole sample consisted of 248 specimens of which 35 immature, 118 females and 95 males were examined. The observed sex-ratio was balanced between males and females (1:0.99; χ2=12; p>0.05. The standard length at first sexual maturity was 54.20 cm for males, and 54.49 cm for females. The spawning period of E. guentheri was established by analyzing the temporal evolution in the monthly variations of the gonado-somatic index (GSI. E. guentheri in Malebo Pool spawns in the end of the dry season but the main breeding season was August and September. The ripe ovaries contained 1953 to 7256 eggs. The relative fecundity was 1745±582 eggs.kg-1 of females. The mean oocyte diameter was 2.12±0.39 mm at spawning. These reproduction characteristics of E. guentheri make it possible to classify this fish among the species with big eggs and low fecundity.

  9. Biologie, abondance et cartographie de deux espèces de bivalves : l’huitre perlière et la coque glauque dans le golfe de Gabes

    OpenAIRE

    Derbali, Abdelkarim

    2011-01-01

    The pearl oyster Pinctada radiata and the cockle Cerastoderma glaucum are among the most abundant bivalve molluscs in southern Tunisian waters. These species are not currently subject to any investigation despite their important economic value in the world. For this reason, their biological parameters, their spatial distribution and their stock assessment were undertaken in the Gulf of Gabes. The reproductive cycle was studied in relation to variations of the environment parameters. The sp...

  10. Le complexe taeniase/cysticercose : la phylogénie et l’évolution de Taenia solium et la biologie moléculaire appliquée au diagnostic

    OpenAIRE

    Michelet, Lorraine

    2010-01-01

    Taenia soliumis responsible for two distinct diseases in humans: taeniasis and cysticercosis. The complex Taeniasis/Cysticercosis has long been investigated because of the impact of the parasite on the human and pig populations.We wanted to study this complex from the angle of the parasite-host system (intermediate host, definitive host and parasite). The main objective of this work is to deepen knowledge of this complex to lead to improved diagnosis of neurocysticercosis. We work primarily o...

  11. Studium reprodukční biologie u raků - páření, kladení a morfologická struktura samčích a samičích gamet

    OpenAIRE

    KUBEC, Jan

    2015-01-01

    In the nature, crayfish are represented like predators or a part of food base of some fish. Also in free waters they acts as detrivors and are an important element in the nutrient and energy circle in aquatic ecosystem. The crayfish weren't able to avoid negative impacts of anthropogenic activities such as water pollution and devastation of habitats. For these reasons reproduction of the crayfish is necessary in hatcheries and farms. The main aim of my work was to study the reproductive biolo...

  12. Le concept de forme organique dans la biologie contemporaine: un examen philosophique. El concepto de forma en la biología contemporánea: examen filosófico

    OpenAIRE

    Nuño de la Rosa García, Laura

    2012-01-01

    Desde finales del siglo XIX, el problema de la forma orgánica (las propiedades geométricas y topológicas de las entidades biológicas a escala anatómica), que hasta entonces había jugado un rol nuclear en la constitución y el desarrollo de las ciencias biológicas, empezó a languidecer hasta su práctica desaparición, determinada por el triunfo de la teoría sintética de la evolución y la teoría genética del desarrollo. No obstante, desde finales de los setenta, la morfología ha experimentado un ...

  13. Mittheilungen über Scyphomedusen I

    NARCIS (Netherlands)

    Stiasny, G.

    1921-01-01

    Hiemit beabsichtige ich eine Reihe kleinerer Mittheilungen über Semaeostomeen und Rhizostomeen des Rijksmuseums van Natuurlijke Historie in Leiden zu veröffentlichen, welche die Systematik, Biologie, Entwicklungsgeschichte und Anatomie verschiedener Scyphomedusen behandeln. Die vorliegenden beiden

  14. Mittheilungen über Scyphomedusen I

    NARCIS (Netherlands)

    Stiasny, G.

    1921-01-01

    Hiemit beabsichtige ich eine Reihe kleinerer Mittheilungen über Semaeostomeen und Rhizostomeen des Rijksmuseums van Natuurlijke Historie in Leiden zu veröffentlichen, welche die Systematik, Biologie, Entwicklungsgeschichte und Anatomie verschiedener Scyphomedusen behandeln. Die vorliegenden beiden k

  15. Big Bang 2 Physik : Schülerbuch

    CERN Document Server

    Apolin, Martin

    2016-01-01

    Physiaklisches Wissen aufbereitet in leicht verständlicher Sprache ; ausgehend von kompetenzorientierten Fragen zu interessanten Antworten ; spannende Bezüge zum Alltag mit Themen aus Sport, Biologie und Medizin.

  16. Aquatic Biological Inventory, Hartwell Drainage and Levee District, Greene County, Illinois

    Science.gov (United States)

    1981-12-07

    1959); Hustedt (1930); Huber- Pestalozzi (1938) Cryptophyta Huber- Pestalozzi (1968) Euglenophyta Huber- Pestalozzi (1955) Chrysophyta Huber- Pestalozzi ...10 pp. () duber- Pestalozzi , G. 1938. Das Phytoplankton des Susswassers: Systematik and Biologie. Blaualgen, Bakter1.on. Die Binnengewasser. Band XVI

  17. Direction des Publications

    African Journals Online (AJOL)

    Synthese

    These results are promising and provide a scientific validation to the massive use of this species. Thus the effect of ... domaines : pharmacie, cosmétique, agro- alimentaire… ..... nosocomiales, Thèse de doctorat biologie,. Univ Mohamed V ...

  18. Sexual reproduction in seed plants, ferns and mosses

    NARCIS (Netherlands)

    Willemse, M.T.M.; Went, van J.L.

    1985-01-01

    Behandeling van de biologie met betrekking tot de geslachtelijke voortplanting van deze plantesoort en onderzoek- en vermeerderingstechnieken op dit gebied. Aandacht voor de ontwikkeling van sporen en microsporen; mannelijke steriliteit; vorming van de stuifmeelbuis en invloeden op diverse ontwikkel

  19. More with thermal energy storage. Report 3-4. Effects on the underground. Effects of thermal energy storage systems on geochemistry and biology in practice. Result of measurements at pilot locations and laboratory tests. Final report; Meer met bodemenergie. Rapport 3-4. Effecten op de ondergrond. Effecten van bodemenergiesystemen op de geochemie en biologie in de praktijk. Resultaat metingen op pilotlocaties en labtesten. Eindrapport

    Energy Technology Data Exchange (ETDEWEB)

    Dinkla, I.; Lieten, S. [Bioclear, Groningen (Netherlands); Hartog, N. [Deltares, Delft (Netherlands); Drijver, B. [IF Technology, Arnhem (Netherlands)

    2012-06-25

    The project More With Thermal Energy Storage (MMB, abbreviated in Dutch) focuses on knowledge gaps and potential opportunities regarding open systems. The main questions to be answered are: (1) What effects (hydrological, thermal, microbiological and chemical) occur in the soil system by application of thermal energy storage; (2) Which technical options are available for a sustainable integration of thermal energy storage in the water and energy chain?; (3) Is it possible to achieve multiple objectives by using smart combinations? The project is organized in different work packages. In work package 2, the effects of individual and collective thermal energy storage storage systems on subsoils and the environment are determined. In work package 3 the opportunities for thermal energy storage and soil remediation are examined, while in work package 4 the focus is on new sustainable combinations of heat and cold storage. Work package 1 is the umbrella part where communication and policy of and participation in MMB are the main subjects. The aim of this literature survey is to search for knowledge that is available worldwide on the effects of heat and cold storage and the possibilities to combine this technology with controlling contaminants in soil and groundwater [Dutch] Het project Meer Met Bodemenergie (MMB) richt zich op het invullen van kennisleemtes en mogelijke kansen ten aanzien van open systemen. De belangrijkste vragen waarop het onderzoeksprogramma MMB antwoord geeft zijn: (1) Welke effecten (hydrologisch, thermisch, microbiologisch en chemisch) treden op in het bodemsysteem bij toepassing van bodemenergie?; (2) Welke technische mogelijkheden zijn er voor het duurzaam inpassen van bodem-energie in de water- en energieketen?; (3) Is het mogelijk om meerdere doelstellingen tegelijk te verwezenlijken door slimme combinaties te maken? Het project is ingericht met verschillende werkpakketten. In werkpakket 2 worden de effecten van individuele en collectieve bodemenergiesystemen op de ondergrond en de omgeving onderzocht, in werkpakket 3 worden de kansen voor bodemenergie en bodemsanering onderzocht en in werkpakket 4 worden nieuwe duurzame combinaties van KWO met andere functies verkend. Werkpakket 1 is het overkoepelende deel waarin communicatie, beleid en participatie van deelnemers van MMB centraal staat. Dit rapport beschrijft de interpretatie van de resultaten behorende bij WP 2.1. De onderzoeksvragen zijn (a) Wat is het effect van open bodemenergiesystemen op de geochemie (adsorptie/desorptie, chemische evenwichten)?; (b) Wat zijn effecten op de microbiele ecologie (samenstelling populaties, activiteit, voorkomen van pathogenen)?; (c) Wat is het effect op de kwaliteit van het grondwater (chemische en (micro)biologische samenstelling)?.

  20. [Around biological evolution. Reflections of a physicist].

    Science.gov (United States)

    Sanchez-Palencia, Evariste

    2016-01-01

    This text is the written version of a talk at the Société de Biologie on February 17, 2016. It contains reflections of a non-biologist scientist on general problems of biological evolution, including the kind of causality involved, the ideas emerging from it, in particular the constructive and structuring character of phenomena such as predation, the role of stability and attractors. This leads to a larger reflection on dialectics, the general framework of evolving processes, which overpasses formal logic and instantaneousness. © Société de Biologie, 2016.

  1. Signature of the C.E.B.M. accord

    CERN Document Server

    Spuhler

    1969-01-01

    Le Conseiller Féderal prend la parole. Pendant la cérémonie plusieurs délégués, qui ont été habilités par leur gouvernement, signent l'accord instituant la conférence européenne de biologie moléculaire pour le développement dans le domaine de la biologie. Il s'agit des pays suivants: Autriche-Danemark-Espagne-France-Grèce-Italie-Norvège-Pays Bas-Allemagne-Royaume Uni de Grande-Bretagne et l'Irlande du Nord-Suède

  2. Liste des Auteurs

    OpenAIRE

    2014-01-01

    Amor Hakima, Université Cadi Ayyad, Faculté des sciences Semlalia, Département de biologie, Laboratoire d’écologie humaine, Marrakech, Maroc. Angeli Aurora, Universita degli studi di Bologna, Dipartimento di scienze statiche “Paolo Fortunati”, Bologne, Italie. Baali Abdellatif, Université Cadi Ayyad, Faculté des sciences Semlalia, Département de biologie, Laboratoire d’écologie humaine, Marrakech, Maroc. Bachtarzi T., Hôpital Ibn Sina, CHU Annaba, Algérie. Baudot Patrick, Université de Proven...

  3. Liste des Auteurs

    OpenAIRE

    2014-01-01

    Amor Hakima, Université Cadi Ayyad, Faculté des sciences Semlalia, Département de biologie, Laboratoire d’écologie humaine, Marrakech, Maroc. Angeli Aurora, Universita degli studi di Bologna, Dipartimento di scienze statiche “Paolo Fortunati”, Bologne, Italie. Baali Abdellatif, Université Cadi Ayyad, Faculté des sciences Semlalia, Département de biologie, Laboratoire d’écologie humaine, Marrakech, Maroc. Bachtarzi T., Hôpital Ibn Sina, CHU Annaba, Algérie. Baudot Patrick, Université de Proven...

  4. Interview with Prof. Soeren M Bentzen (with english subtitles)

    CERN Multimedia

    Antonella del Rosso

    2012-01-01

    Interview with Prof. Soeren M Benzen, University of Wisconsin, Madison, on the role of physics biology and genomics in cancer treatment today. Interview avec le prof. Soeren Benzen, Université de Wisconsin, Madison, sur le role de la physique, la biologie et la genomique dans le traitement du cancer aujourd'hui.

  5. Influence of Hydrodynamics on the Larval Supply to Hydrothermal Vents on the East Pacific Rise

    Science.gov (United States)

    2007-06-01

    dispersal in deep-sea hydrothernal vent animals. Cahier de Biologic Marine, 39:363:366. [37] Witman, J. (1987). Subtidal coexistence: storms, grazing...Sunderland, 2001. [54] R. C. Vrijenhoek, T. M. Shank, and R. Lutz. Gene flow and dispersal in deep-sea hydrothermal vent animals. Cahier de Biologie Marine, 39

  6. Kannibalisme onder sardinella's

    NARCIS (Netherlands)

    Mantingh, I.T.

    2003-01-01

    Verslag van het RIVO onderzoek in Mauritanië naar de biologie van sardinella. Om de migratiepatronen van de Sardinella aurita in de Noord-west-Afrikaanse wateren te achterhalen zijn gegevens van Nederlandse trawlers en lokale kano's gebruikt. Ook ontdekte men kannibalisme onder sardinella's

  7. Productivité de la culture du sorgho (Sorghum bicolor) dans un ...

    African Journals Online (AJOL)

    SARAH

    31 oct. 2014 ... 2 Département de Biologie, Faculté des Sciences et Techniques, Université Abdou Moumouni BP ... intérêt pratique car l'association A. senegal-cultures pourrait être une alternative aux intrants chimiques de ..... ruissellement pluvial sous l'arbre ; l'absorption et le ... meilleure gestion de l'association.

  8. Applications of Mathematical Morphology to Range Imagery

    Science.gov (United States)

    1987-12-23

    la distribution spatiale des ovogonies dans l’ovaire d’embryon de ratte ä l’aide de l’analyseur de textures," Annales de Biologie Animale , Vol. 13...this reference can be considered the state of the art of MM (up to 1982). [35] Serra, J., "Principles, Criteria and Algorithms in Mathematical

  9. Evénement Diversité - "Le Cerveau a-t-il un sexe ?" - C. Vidal

    CERN Document Server

    CERN. Geneva

    2013-01-01

    L'objectif de cette conférence est de donner à comprendre le rôle de la biologie mais aussi l'influence de l'environnement social et culturel dans la construction de nos identités de femmes et d'hommes.

  10. Vertigo substriata Jeffreys, faunae neerlandicae nova species, een zoogenaamd glaciaalrelikt

    NARCIS (Netherlands)

    Sunier, A.L.J.

    1926-01-01

    I. HET NEDERLANDSCHE MATERIAAL VAN VERTIGO SUBSTRIATA JEFFR.. Onder het vaak interessante materiaal van Nederlandsche Mollusca, dat den laatsten tijd door de Heeren W. F. van Hell en J. A. Nijkamp, studenten in de biologie te Leiden, aan 's Rijks Museum van Natuurlijke Historie werd afgestaan, trof

  11. De wilde rozen (Rosa L.) van Nederland

    NARCIS (Netherlands)

    Bakker, Piet A.; Maes, Bert N.C.M.; Kruijer, Hans J.D.

    2011-01-01

    Dit artikel in boekvorm biedt nieuwe inzichten in het complexe geslacht Rosa L. en presenteert een systematische bewerking van de in Nederland in het wild voorkomende rozensoorten. In inleidende hoofdstukken worden de cultuurhistorie, biologie, morfologie, genetica, taxonomie en ecologie van rozen

  12. Role of Nuclear Matrix in Estrogen Regulated Gene Expression in Human Breast Cancer Cells

    Science.gov (United States)

    1998-08-01

    form of endocrine manipulative therapy, e.g., antiestrogen therapy. However, most human breast cancers originate as hormonally dependent tumors as...development. 49 "Proprietary Data - Distribution to Government Agencies Only" ACKNOWLEDGMENTS Pierre Chambon (Institut de Genetique et de Biologie

  13. Répartition et valorisation des macrophytes envahissantes dans la ...

    African Journals Online (AJOL)

    SARAH

    30 avr. 2016 ... 1 : Département de Biologie des Organismes végétaux, Faculté des Sciences, Université de Douala. *Auteur de ... 72g/100g, les protéines < 20% et lipides y sont en traces. .... (graisses, huiles volatiles) dans le ballon. Après.

  14. C:\\Users\\AISA\\Desktop\\E.K KONAN.xps

    African Journals Online (AJOL)

    AISA

    Reprise en acclimatation des vitroplants enracinés de palmier à huile régénérés ... 3Laboratoire de Biologie et Amélioration des Productions Végétales, UFR des Sciences de la Nature, ...... et protéines) ou d'une déficience physiologique.

  15. Étude de la qualité biochimique et nutritionnelle de la poudre ...

    African Journals Online (AJOL)

    SARAH

    31 déc. 2015 ... 3 Département de Physiologique Animale, UFR Biologie, Université Peleforo Gon Coulibaly, Korhogo (Côte d'Ivoire). ..... linolénique 3 (0,82%) dits essentiels, et le ratio 3. 6. Ω .... 6/omega-3 essential fatty acids, biomedicine &.

  16. Verwandtschaftliche Gruppierung und Verbreitung der Karibischen Winkerkrabben (Ocypodidae, Gattung Uca)

    NARCIS (Netherlands)

    Hagen, H.O.V.

    1970-01-01

    EINLEITUNG Bei einem Aufenthalt auf der westindischen Insel Trinidad in den Jahren 1965/66 hatte ich Gelegenheit, die meisten karibischen Winkerkrabben der Gattung Uca sowie Daten über ihre Biologie, Ökologie und Verbreitung zu sammeln. Ein Teil des Materials, d.h. Vertreter aller 9 auf Trinidad

  17. 2633-IJBCS-Article-Luc Gangbe

    African Journals Online (AJOL)

    hp

    morphologie, de la biologie de reproduction et des besoins alimentaires en élevage de M. vollenhovenii afin d'entreprendre son ... give the hatch small larvae called nauplius that evolves zoe and mysis. After 15 larval ..... Fécondité et sex ratio.

  18. Notas bibliográficas

    OpenAIRE

    Delgado Campo, Hernando

    2011-01-01

    Introducción a la lógica jurídica.  García Maynez, Eduardo. / Edmundo Husserl.  Stoerig, Hans Joachim. / La structure de l'organisme: Introduction à la biologie à partir de la pathologie humaine.  Goldstein, Kurt. / Documentos: número 8.  Corte, Marcel de; Santamaria, Carlos; Leclercq, Jacques; [et al].

  19. Kannibalisme onder sardinella's

    NARCIS (Netherlands)

    Mantingh, I.T.

    2003-01-01

    Verslag van het RIVO onderzoek in Mauritanië naar de biologie van sardinella. Om de migratiepatronen van de Sardinella aurita in de Noord-west-Afrikaanse wateren te achterhalen zijn gegevens van Nederlandse trawlers en lokale kano's gebruikt. Ook ontdekte men kannibalisme onder sardinella's

  20. Monsters omarmen in grensgebieden en achterkamers: genomic en de veranderende relaties tussen wetenschap, filosofie en kunst

    NARCIS (Netherlands)

    Weele, van der C.N.

    2005-01-01

    De auteur verkent in dit artikel het complexe grensgebied van biologie, filosofie en kunst en de verschuivingen die daar sinds de opkomst van biotechnologie en genomics in zijn opgetreden. Dit wordt gedaan aan de hand van de 'cyborgs' en 'oncomice' van Donna Haraway, de lichtgevende transgene konijn

  1. Parasitisme de Dacryodes edulis par le genre Tapinanthus ...

    African Journals Online (AJOL)

    SARAH

    31 août 2013 ... 1Laboratoire de Biologie et Physiologie des Organismes Végétaux, ... fruits de Tapinanthus et son activité variait en fonction de la floraison et de la fructification des deux ... matière organique dont il a besoin (Kuijt, 1969 ;.

  2. 2280-IJBCS-Article-Agbangba Codjo Emile

    African Journals Online (AJOL)

    hp

    1Université Cheikh Anta Diop, Département de Biologie Végétale,. Laboratoire ... réalisée sur les caractéristiques sensorielles et physico-chimiques des fruits. Les traitements T1 .... de matière organique (1,31-1,43%) est faible. La teneur en ...

  3. Activité antioxydante des extraits méthanoliques de Phragmanthera ...

    African Journals Online (AJOL)

    2014-12-29

    Dec 29, 2014 ... 1Laboratoire de Biologie et Physiologie des Organismes Végétaux, Faculté des Sciences, ... 4Laboratoire de Chimie Organique, École Normale Supérieure, Université de Yaoundé ..... extraits de feuilles, de fruits et de fleurs.

  4. 1914 -IJBCS-Article-Siribi Soulama

    African Journals Online (AJOL)

    hp

    3Laboratoire de Biologie et Ecologie Végétales, Unité de Formation et de Recherche en Sciences de la Vie ... Ils montrent aussi que le fourrage (feuilles et fruits) des espèces étudiées peut contribuer ... digestibilité des matières organiques et.

  5. New Publications and Videos

    Directory of Open Access Journals (Sweden)

    Eugene R. Potapov

    2015-12-01

    Full Text Available Potapov E. & R. Sale. The Snowy Owl. T. & A.D. Poyser. London, 2013. 304 p. ISBN: 978-0713688177. Mebs, T., Schmidt, D. Die Greifvögel Europas, Nordafrikas und Vorderasiens: Biologie, Kennzeichen, Bestände. Kosmos Verlag, Stuttgart, 2014. 496 s. ISBN: 978-3-440-14470-1.

  6. Effectieve bestrijding van varroa

    NARCIS (Netherlands)

    Cornelissen, B.; Blacquiere, T.; Steen, van der J.J.M.

    2010-01-01

    De varroa mijtziekte (Varroa destructor) is de belangrijkste bedreiging van de Europese honingbij. Wintersterfte van honingbijen is in de meeste gevallen toe te schrijven aan deze ziekte. Deze brochure van de WUR biedt informatie over de biologie van varroa, de effecten van varroa op honingbijen en

  7. Effectieve bestrijding van varroa (Tweede, licht gewijzigde druk)

    NARCIS (Netherlands)

    Cornelissen, B.; Blacquière, T.; Steen, van der J.J.M.

    2013-01-01

    De varroa mijtziekte (Varroa destructor) is de belangrijkste bedreiging van de Europese honingbij. Wintersterfte van honingbijen is in de meeste gevallen toe te schrijven aan deze ziekte. Deze tweede, licht gewijzigde druk biedt informatie over de biologie van varroa, de effecten van varroa op honin

  8. Festschrift Charpak (Georges) on his 65th birthday

    CERN Document Server

    Lehmann, Pierre; Rubbia, Carlo; Saudinos, Jean; CERN. Geneva

    1989-01-01

    On the occasion of the 65th birthday of Georges Charpak and of his retirement, the Director-General and the EP Division invite you to a symposium in his h. Chairman : P. Lehmann. - Opening address : C. Rubbia. - Message from V. Weisskopf. - L. Lederman : Superstrings needs sealing wax. - J. Saudinos : Quelques applications des detecteurs gazeux a la medecine et a la biologie.

  9. Notas bibliográficas

    OpenAIRE

    Delgado Campo, Hernando

    2011-01-01

    Introducción a la lógica jurídica.  García Maynez, Eduardo. / Edmundo Husserl.  Stoerig, Hans Joachim. / La structure de l'organisme: Introduction à la biologie à partir de la pathologie humaine.  Goldstein, Kurt. / Documentos: número 8.  Corte, Marcel de; Santamaria, Carlos; Leclercq, Jacques; [et al].

  10. Dades sobre la biologia d'espècies ibèrico-baleàriques d'Artemisia L.

    Directory of Open Access Journals (Sweden)

    Vallès Xirau, Joan

    1989-06-01

    Full Text Available Not available

    [ca] S'estudien diversos aspectes de la biologia de les espècies ib èrico-baleàriques d'Artemisia L., fonamentalment de les seccions Artemisia L. i Seriphidium Besser. La germinació de les cipseles, el tipus de cicle biològic, la biologia de la reproducció i la fenologia són els principals termes tractats. [fr] On étude des aspects divers de la biologie des espèces ibéro-baléariques du genre Artemisia L., notamment des sections Artemisia L. et Seriphidium Besser. La germination des cypseles, le type du cycle biologique, la biologie de la reproduction et la phénologie sont les principaux points traités.

  11. 458-IJBCS-Article-Dibong Siegfried Didier

    African Journals Online (AJOL)

    DR GATSING

    2 Institut de Recherche d'Ecologie Tropicale (IRET), B. P. 13354 Libreville, Gabon. 3 Laboratoire de Parasitologie végétale, Université Pierre et Marie Curie (Paris VI), 4 place Jussieu, case ... 6 Département de Biologie et Physiologie Végétales, B. P. 812, Université de .... statistiques sont réalisées à l'aide du logiciel.

  12. The Mosquitoes of the Subgenus Culex in Southwestern Asia and Egypt (Diptera: Culicidae) (Contributions of the American Entomological Institute. Volume 24, Number 1, 1988)

    Science.gov (United States)

    1988-01-01

    Pathol. Exot. 53: 531-542. 1968. Contribution a I’etude des moustiques du Maroc (Diptera, Culicidae) six especes nouvelles pour le pays. Cah. ORSTOM...quelques moustiques du Maroc. Arch. inst. Pasteur Maroc 2: 361-365. 1957. Sur Culex torrentium Martini. Ann. Parasitol. Hum. Comp. 32: 438-442...De Grandpre, A.D. and D. D’E. De Charmoy 1900(1901). Les moustiques : anatomie et biologie. Contribution a I’etude des Culicides et principalement

  13. Novel methods for studying lipids and lipases and their mutual interaction at interfaces. Part 1. Atomic force microscopy

    DEFF Research Database (Denmark)

    Balashev, K.; Jensen, T.R.; Kjær, K.;

    2001-01-01

    Mono-layers of lipids and their interaction with surface active enzymes (lipases) have been studied for more than a century. During the past decade new insight into this area has been obtained due to the development of scanning probe microscopy. This novel method provides direct microscopic...... on lipase hydrolysis and kinetics investigated in situ using AFM. (C) 2001 Societe francaise de biochimie et biologie moleculaire/Editions scientifiques et medicales Elsevier SAS. All rights reserved....

  14. AGARD (Advisory Group for Aerospace Research & Development) Index of Publications, 1980-1982.

    Science.gov (United States)

    1984-01-01

    de Biologie Aerospatiale. Paris very similar to human spondylosis deformans is provided. (France) Service de Biomecanique. B’-log" A a r spondylosis ...appearance of spondylosis deformans strongly INTERVERTERBRAUX LOMBAIRES D’UN PRIMATE I suggests that the pathological changes are the direct result of P...action control andi contro, confrr edc eh-icir TITLE RPR PAE ACCESSION transmissiity offheinleroerfnbral lambar disksof aprimate AGARD-AR-tl 5tto 1 Net

  15. Bibliografía

    OpenAIRE

    Mankeliunas, Mateo V.; Ardila y Ardila, Rubén

    2012-01-01

    Jean Piaget. Biologie et Connaissance: Essai sur Ies relations entre les regulations organiques et Ies processus cognitifs, Paris: Gallimard, 1967,430 pgs. Precio: Fr. 22.00 / R. F. Thompson. Foundations of Physiological Psychology. New York, Evanston & London: Harper & Row, 1967, XVIII + 688 pgs. Precio: US$ 6.00. / ]. B. SmowsKI (Ed.) Experimental Methods and Instrumentation in Psychology. New York; McGraw Hill, 1966, X + 803 pags. Precio: US$ 15.00. / Paul Fraisse & Jean Piaget...

  16. Simulation Modeling of Zooplankton and Benthos in Reservoirs: Documentation and Development of Model Constructs.

    Science.gov (United States)

    1980-03-01

    des conditions ecologiques. Cahiers de Biologie Marine, 17: 37-43. BOVEE, E. C. 1949. Studies on the thermal death rate of Hyallela azteca , Saussure...1965. Dynamics and production of a natural population of fresh-water amphipod, Hyalella azteca . Ecological Monographs, 35: 377-394. CORNER, E. D. S...B. T. 1970. The utilization of benthic microflora by Hyalella azteca (Amphipoda). Journal of Animal Ecology, 39: 427-437. HARGRAVE, B. T. 1971. An

  17. Urie Bronfenbrenner 1917-2005. Facetten eines persönlichen Porträts

    OpenAIRE

    Lüscher, Kurt

    2006-01-01

    Urie Bronfenbrenner hat mit seiner Ökologie menschlicher Entwicklung einen wesentlichen Beitrag zu einer - die Biologie einschließenden - transdisziplinären Sozialisationstheorie geleistet und der Forschung sowie der sozialpolitischen Praxis wichtige Impulse vermittelt. Zur Würdigung seines Werks und seines Wirkens gehört untrennbar eine Schilderung der Ausstrahlung seiner Persönlichkeit und seines steten Engagements für die Belange der Kinder und Familien. (DIPF/Orig.) Urie Bronfenbrenner...

  18. Trivalente Präsentation von Peptiden am Beispiel von HIV-1 gp120

    OpenAIRE

    Berthelmann, Arne

    2014-01-01

    Multivalente Interaktionen spielen in der Biologie, beispielsweise bei der Interaktion zwischen Viren, wie Influenza oder dem Humanen-Immunodefizienz-Virus (HIV), und ihren Wirtszellen eine wichtige Rolle. Innerhalb der multivalenten Interaktionen wiederum sind häufig trimere Moleküle vertreten. Um diese Systeme zu untersuchen bzw. zu beeinflussen, bietet es sich an, entsprechend trivalente Peptidliganden einzusetzen. Daher wurden in der vorliegenden Arbeit Strategien zur trivalenten Präsenta...

  19. Résistance osmotique et phosphatides du sang

    NARCIS (Netherlands)

    Brinkman, Robert

    1922-01-01

    1. La détermination de la résistance osmotique des globules sanguins se faisait, jusqu'iei, presque toujours au moyen d'une solution de NaCl pure. Or, d'un point de vue de biologie générale une telle solution doit être considérée comme peu appropriée à ce genre de recherches, parce qu'elle exerce un

  20. Recent Advances in Supramolecular Assemblies with Nucleic Acids

    Science.gov (United States)

    2007-08-29

    Chairman 3:00-3:30 Jean Herscovici, Ecole Nationale Supérieure de Chimie de Paris (France) “Lipopolythioureas: a New Efficient Non Cationic System...DNA nanostructures” 10:00-10:30 Ivan Huc, Institut Européen de Chimie Biologie (IECB), Bordeaux (France) “Artificial Double Helical...Ecole Nationale Supérieure de Chimie de Paris (France) “Lipopolythioureas: a New Efficient Non Cationic System for Gene Delivery” Abstract

  1. Invasieve Arthropoda in Nederland: een eerste inventarisatie

    OpenAIRE

    Reemer, M.

    2003-01-01

    Invasieve Arthropoda in Nederland: een eerste inventarisatie Hieronder worden soorten verstaan die zich sinds 1950 in Nederland gevestigd hebben en zich sterk hebben uitgebreid. Het overzicht kwam tot stand via een enquête onder circa 50 specialisten en beperkt zich tot de soorten waarvan het invasieve karakter duidelijk en gedocumenteerd is. De totale lijst bevat 104 invasieve soorten Arthropoda en geeft basale informatie over het voorkomen in Nederland, biologie, ecologie en relevante liter...

  2. La Liberté sémiotique

    DEFF Research Database (Denmark)

    Hoffmeyer, Jesper

    2016-01-01

    Cet article présente des arguments en vue d’une résolution des problèmes liés à la question de l’intentionnalité naturelle dans une perspective biosémiotique. En confrontant les théories de l’information au modèle évolutionniste dominant en biologie, l’auteur montre les insuffisances du...

  3. Globale Entwikclung als Lernbereich in den Naturwissenschaften

    OpenAIRE

    Härtig, Hendrik; Bernholt, Sascha; Schroeter, Burkhard

    2014-01-01

    Mit dem Orientierungsrahmen für den Lernbereich Globale Entwicklung wurden Anregungen gegeben, die Themen nachhaltige Entwicklung und globale Entwicklung im Unterricht in allen Schulfächern aufzugreifen. Die drei naturwissenschaftlichen Schulfächer Biologie, Chemie und Physik haben sich bislang sehr unterschiedlich auf das Thema eingelassen. In der Biologiedidaktik finden sich sowohl Forschungsarbeiten als auch Unterrichtsvorschläge; für Chemie und insbesondere Physik existieren hingegen nur ...

  4. Biotegnologie — ’n Nuwe benadering in planteteling

    Directory of Open Access Journals (Sweden)

    D. I. Ferreira

    1991-07-01

    Full Text Available Konvensionele planteteling het tydens die laaste halfeeu ’n merkwaardige toename in gewasproduksie tot gevolg gehad. Verskeie tekortkominge in die benadering het egter geleenthede vir die toepassing van biotegnologie in planteteling geskep. Die verskillende benaderings op die gebied van selbiologie (weefselkultuur en molekulêre biologie (rekombinante DNS-tegnologie word bespreek en die toepassing daarvan in ’n globale benadering tot planteteling word bepleit.

  5. Énergies

    OpenAIRE

    Albe, Virginie; Bächtold, Manuel; Buty, Christian; Cross, David; Fontanieu, Valérie; Grangeat, Michel; Guedj, Muriel; Hage, Suzane El; Hebel, Florence Le; Hervé, Nicolas; Lerouge, Alain; Mayrargue, Arnaud; Montpied, Pascale; Morge, Ludovic; Munier, Valérie

    2015-01-01

    L’énergie est un thème mobilisé en biologie, en chimie, en géologie, en physique et en technologie. En outre, l’énergie intéresse également les champs investis par les questions socialement vives (la consommation et les économies d’énergie, etc.) ainsi que les domaines de l’éducation à la santé (avec les notions de calories, d’effort physique, de bilan, etc.), au développement durable (ressource énergétique, réchauffement climatique, énergie renouvelable ou non-renouvelable, etc.). Cependant,...

  6. Changes during hibernation in different phospholipid and free and esterified cholesterol serum levels in black bears

    Science.gov (United States)

    Chauhan, V.; Sheikh, A.; Chauhan, A.; Tsiouris, J.; Malik, M.; Vaughan, M.

    2002-01-01

    During hibernation, fat is known to be the preferred source of energy. A detailed analysis of different phospholipids, as well as free and esterified cholesterol, was conducted to investigate lipid abnormalities during hibernation. The levels of total phospholipids and total cholesterol in the serum of black bears were found to increase significantly in hibernation as compared with the active state. Both free and esterified cholesterol were increased in the hibernating state in comparison with the active state (P biochimie et biologie mole??culaire. All rights reserved.

  7. [Cognitive and brain development of memory from infancy to early adulthood].

    Science.gov (United States)

    Dégeilh, Fanny; Eustache, Francis; Guillery-Girard, Bérengère

    2015-01-01

    Cognitive and brain development are closely linked from infancy to adulthood. The purpose of this article is to review the current state of knowledge on behavioral and brain substrates of memory development. First, we will review cognitive development of different memory systems, from procedural to autobiographical memory. We will discuss how the development of other cognitive functions (language, attention, executive functions and metamemory) participates in memory development. Second, we will describe how structural and functional changes in two core brain regions of memory, i.e. the hippocampus and the prefrontal cortex, impact the protracted development of memory throughout childhood. © Société de Biologie, 2016.

  8. OMX - a novel high speed and high resolution microscope and its application to nuclear and chromosomal structure analysis

    OpenAIRE

    Haase, Sebastian

    2008-01-01

    Im Rahmen dieser Arbeit wurde ein neuartiges 3D Fluoreszenz Mikroskop, OMX gennant, entworfen und gebaut. Ein umfassender Design-Neuansatz erlaubt es den neuen Anforderungen der aktuellen Biologie bezüglich erhöhter Auflösung in Zeit und Raum Rechnung zu tragen. Mit Ausnahme vom Auflegen des Objektträgers sind alle Aspekte des Mikroskops Computer-gesteuert. Einen Großteil der Software floß in ein neues, eigenständiges Open-Source Projekt ein. Es erlaubt die Verarbeitung sehr großer, ...

  9. Les premiers textes de René Thom sur la morphogenèse et la linguistique : 1966-1970.

    OpenAIRE

    Petitot, Jean

    2015-01-01

    Au milieu des années 1960, René Thom commença à rédiger ses premiers textes sur les applications à la morphogenèse en biologie et à la syntaxe actantielle en linguistique de la théorie des déploiements universels de singularités de fonctions differentiables et de la stabilité structurelle. Cette note présente et commente ses cinq premiers articles dans ces domaines.

  10. KMT moving bed biofilm reactor (KMT MBBR) experience of a pilot plant in Spain. Proceso KMT de biomasa fija sobre lecho movil. Experiencias en planta piloto en Espaa

    Energy Technology Data Exchange (ETDEWEB)

    Montoya Aranda, A.; Rodrigo Alonso, J.C.

    1994-01-01

    It describes the experiments carried out by INFILCO ESPAOLA, S.A. in a pilot plant using the KMT Moving Bed Biofilm Reactor process involving a fixed biomass on a moveable bed. This is an innovative process for treating both industrial and urban waste waters with or without the elimination of nutrients. The experimental findings demonstrate the need for a minimum amount of space for the biologial reagent (in comparison with that required for active sludge EDARs). They also show the ease with which existing EDARs can be adapted with very little civil engineering work by increasing either the design capacity or the elimination of nutrients. 10 refs.

  11. Adéquation d'indices statistiques à l'interprétation de règles d'association

    OpenAIRE

    Cherfi, Hacène; Toussaint, Yannick

    2002-01-01

    Colloque avec actes et comité de lecture. internationale.; International audience; Nous proposons, dans cet article, la description d'une méthodologie d'accès et de lecture des règles d'association extraites à partir de textes. Le corpus qui a servi à notre expérience est une collection de textes sous forme de résumés d'articles scientifiques dans le domaine de la biologie moléculaire. Notre recherche porte sur : i)l'extraction des règles d'association à partir de la construction des ensemble...

  12. Pollution of the sea (mediterranean)

    CERN Multimedia

    Vicente,N

    1980-01-01

    Le Prof. Nardi Vicente travaille au laboratoire et est Prof. de biologie marine de l'Université de Marseille. Il participe à plusieurs missions, notamment avec le Prof. Coustaud. La conférence est agrémenté d'un film qui a obtenu la palme d'or à Rio de Janeiro. La pollution de la mer méd. provient pour 75% de l'intérieur de terre et les fleuves sont résponsables pour une grande partie et notamment le Rhône qui abouti en Méditerranée.

  13. Cell Source and Mechanism of Hair Cell Regeneration in the Neonatal Mouse Cochlea

    Science.gov (United States)

    2015-09-30

    lines to manipulate gene expression in two distinct cell types in vivo. B .... ~ ,>~’ - ·’ ~,r .·· ,. ’ ’’ 0 ,~ ’ ~ E ~ c::) mChtny+ IHCS...Jude) for Atoh1 -CreERTM mice and discussion; R. Kageyama (Kyoto University) for Hes5-nlslacZ mice; P. Chambon (lnstitut Genetique Biologie Moleculaire...Similar manipulations failed to coerce a HC fate in the undamaged, adul t cochlea, suggesti ng that the neonatal cochlea is a more pem1issive

  14. Les processidae (Crustacea Decapoda Natantia) des eaux Européennes

    NARCIS (Netherlands)

    Nouvel, H.; Holthuis, L.B.

    1957-01-01

    PRÉ FACE Au cours d'études sur la biologie des Processa des mers européennes (1937-1944), le premier auteur fut frappé par les différences singulières que présentaient des spécimens qui, en accord avec l'opinion courante, devaient se rapporter à une même espèce. I1 résolut d'approfondir le côté syst

  15. Prächtige Porträts erfolgreicher Forscherinnen Magnificent Portraits of Successful Researchers—An Encouragement to Young Women?

    Directory of Open Access Journals (Sweden)

    Ulrike Vogel

    2008-11-01

    Full Text Available Mit jeweils kurzen Texten und großen, illustrativen Fotos werden herausragende Forscherinnen aus Mathematik, Physik, Biologie und Medizin vorgestellt. Es werden Einblicke in die Arbeit der Wissenschaftlerinnen gegeben sowie Hinweise auf deren Wissenschaftskarriere und auch das private Umfeld. Meisterhafte Fotos und anschaulich formulierte Texte machen dieses Buch zu einem Lesevergnügen.Using short texts and large, illustrative photos respectively, the volume introduces excellent female researchers of mathematics, physics, biology, and medicine. They give insight into the work of female scientists as well as references to their scientific career and their private surroundings. Expert photos and descriptively formulated texts make this book a joy to read.

  16. Online-Lernen mit Studierenden:Beispiel am Projekt "Wasser"

    OpenAIRE

    Graf, D.; Klee, R. (Rainer)

    2003-01-01

    Im WS 1999/2000 wird an der Universität Gießen zum ersten Mal im deutschsprachigen Raum ein Seminar für Lehramtsstudierende der Biologie (Thema Wasser) angeboten, das ausschließlich Online im Internet stattfindet. Sowohl zur Wissensaneignung als auch zur Kommunikation zwischen den Teilnehmern wird eine speziell entwickelte Software eingesetzt. Der nachfolgende Beitrag legt einige grundsätzliche Überlegungen zum Online-Lernen dar, die dem Programm zu Grunde liegen. Am Ende der Ausführungen wir...

  17. Some bio-morphological particularities of hop (Humulus lupulus L. cultivated near Cluj

    Directory of Open Access Journals (Sweden)

    Alexandru SALONTAI

    1977-08-01

    Full Text Available Le houblon est l' une des plantes avec une grande plasticite biologique presentant, en fonction de l'acclimatation, differentes particularites morphologiques, anatomiques et fonctionnelles (1, 2, 3, 6. Bien que le houblon soit cultive depuis tres longtemps dans notre pays les etudes scientifiques portant sur la morpho-biologie sont peu nombreuses (4, 5. Dans cette etude sont presentes les resultats de certaines recherches portant sur la structure morpho - biologique des sortes de houblon, comparativement aux sortes plus valeureuses en culture a la Station experimentale de l'Institut Agronomique de Cluj-Napoca.

  18. Modelling of Molecular Structures and Properties in Physical Chemistry and Biophysics, Forty-Fourth International Meeting (Modelisation des Structures et Proprietes Moleculaires en Chimie Physique et en Biophysique, Quarante- Quatrieme Reunion Internationale)

    Science.gov (United States)

    1989-09-01

    METHODOLOGY AND FIRST RESULTS ON CITRATE SYNTHASE Jean Durup Laboratoire de Physique Quantique (UA 505 du C.N.R.S.) 118, route de Narbonne, 31062 TOULOUSE...de la Brosse ESPCI 750 05 PARIS Lab. Chirn~ analyt ique 10. rue Vauquelin 75231 PARIS Cedex 55 DU-RUP j. Physique quantique FRIANT P. \\Ilie Univ. Paul...8217- Valencia Dr. Moliner 50 46100 BURJASSOT (Espagne) StMITH 3. CISI-CEA TRINQUIER C. Service de Biophysique Physique quantique Depart. de Biologie Univ. Paul

  19. Histoire de la radioactivité. L'évolution d'un concept et de ses applications

    OpenAIRE

    Beck, C.

    2007-01-01

    Depuis sa découverte, la radioactivité est, par ses applications diverses, de plus en plus omniprésente dans notre vie quotidienne. Outre la production de l'électricité, elle trouve plusieurs applications : en médecine et biologie pour le diagnostic et le traitement des cancers, dans l'industrie pour le contrôle non destructif par gammagraphie et bêtagraphie, en agronomie et agroalimentaire pour la modification génétique et la conservation des denrées, en géosciences pour les analyses chimiqu...

  20. The Power and Promise of Developmental Systems Theory

    Directory of Open Access Journals (Sweden)

    Letitia Meynell

    2008-09-01

    Full Text Available I argue that it is time for many feminists to rethink their attitudes towards evolutionary biology, not because feminists have been wrong to be deeply sceptical about many of its claims, both explicit and implicit, but because biology itself has changed. A new appreciation for the importance of development in biology has become mainstream and a new ontology, associated with developmental systems theory (DST, has been introduced over the last two decades. This turn challenges some of the features of evolutionary biology that have most troubled feminists. DST undermines the idea of biologicales sence and challenges both nature /nurture and nature/culture distinctions. Freed from these conceptual constraints, evolutionary biology no longer poses the problems that have justified feminist scepticism. Indeed, feminists have already found useful applications for DST and I argue that they should expand their use of DST to support more radical and wide-ranging political theories.Si les féministes n’ont pas eu tort d’être profondément sceptiques face aux nombreuses revendications de la biologie, leur attitude face à cette science doit être remise en question car la biologie s’est transformée au courant des dernières décennies. La «théorie des systèmes de développement» (developmental systems theory-TDS est une théorie qui s’est considérablement développée et qui a pris beaucoup d’ampleur. Cette théorie n’accepte pas le concept d’essence biologique ce qui pose un défi important à la distinction nature/culture. Une des conséquences de cet apport théorique est que le scepticisme des féministes face à la biologie de l’évolution n’est plus justifié car la biologie ne comporte plus les contraintes essentialistes qui s’avéraient contentieuses. En effet, certaines féministes ont déjà trouvé des applications utiles pour la TDS et nous avançons que les féministes doivent maintenant élargir l’utilisation de la

  1. Le genre Tunga Jarocki, 1838 (Siphonaptera : Tungidae. I – Taxonomie, phylogénie, écologie, rôle pathogène

    Directory of Open Access Journals (Sweden)

    Beaucournu J.-C.

    2012-11-01

    Full Text Available Pour la première fois, les 12 espèces actuellement décrites dans le genre Tunga sont étudiées sur le plan de la taxonomie et de la répartition. Divers aspects de leur biologie et leur rôle pathogène sont également envisagés, et en particulier leur phylogénie, leur chorologie, leur phénologie, leur sexe-ratio et leurs dermecos.

  2. Le genre Tunga Jarocki, 1838 (Siphonaptera : Tungidae). I – Taxonomie, phylogénie, écologie, rôle pathogène

    Science.gov (United States)

    Beaucournu, J.-C.; Degeilh, B.; Mergey, T.; Muñoz-Leal, S.; González-Acuña, D.

    2012-01-01

    Pour la première fois, les 12 espèces actuellement décrites dans le genre Tunga sont étudiées sur le plan de la taxonomie et de la répartition. Divers aspects de leur biologie et leur rôle pathogène sont également envisagés, et en particulier leur phylogénie, leur chorologie, leur phénologie, leur sexe-ratio et leurs dermecos. PMID:23193514

  3. 城市污水处理厂恶臭影响及对策分析%Analysis of impact of Odor in Urban Wastewater Treatment Plant and Its Countermeasures

    Institute of Scientific and Technical Information of China (English)

    王喜红

    2011-01-01

    This article describes site and cause of the odor in urban wastewater treatment plant, discusses method of determining odor, analyses impact of odor and expounds location, layout, landscaping of waste water treatment plant and biologieal deodorant and other countermeasures.%介绍了城市污水厂恶臭主要产生部位、产生原因,恶臭源强的确定方法,恶臭产生的影响,以及污水处理厂选址、布局、绿化、生物除臭、管理等恶臭对策分析。

  4. Highlights of the 6th world congress of nuclear medicine and biology

    Energy Technology Data Exchange (ETDEWEB)

    Ell, P.J. [Inst. of Nuclear Medicine, University Coll. London Medical School, London (United Kingdom)

    1995-02-01

    The article summarizes the most interesting medical aspects of the 6th World Congress of Nuclear Medicine and Biology, addressing recent developments in the fields of scintiscanning, SPET and PET, oncology, neurology, psychiatry, in the diagnostic evaluation of the cardiovascular system, and new radiopharmaceuticals. (VHE) [Deutsch] Der Artikel gibt einen Ueberblick ueber medizinische Aspekte des 6. Weltkongresses der Nuklearmedizin und -biologie. Aktuelle Entwicklungen bei Szintigraphie, SPET und PET in Onkologie, Neurologie, Psychiatrie, Herz und Kreislauf sowie weitere neue Entwicklungen bei Radiopharmazeutika werden referiert. (VHE)

  5. [EEQ in clinical embryology: a starting program].

    Science.gov (United States)

    Boyer, Pierre; Brugnon, Florence; Levy, Rachel; Pfeffer, Jérôme; Siest, Jean-Pascal

    2014-01-01

    Every laboratory including those working in assisted reproductive technologies have to be accredited EN ISO 15189 before 2020. This standardisation includes an external quality evaluation (EQE). In order to work out an EQE tool, we used images extracted from our own database developed during daily practice. We achieved an easily online tool called: "EEQ en embryologie clinique", developed on Biologie prospective web site with ART French biologists Association (Blefco) expertise in evaluation of early human embryonic stages. In 2013, 38 ART laboratories participate to the first program with more than 90% of appropriates results. The present article aims at describing this tool and discussing its limits.

  6. Herbert Spencer en France

    OpenAIRE

    Bender, Niklas; Cabanès, Jean-Louis; Fonyi, Antonia; Guthmüller, Marie; Leclerc, Yvan; Ottavi, Dominique; Plas, Régine; Salanskis,Emmanuel; Séginger, Gisèle

    2015-01-01

    Herbert Spencer (1820-1903) est un des intellectuels anglais les plus importants du XIXe siècle : penseur universaliste et écrivain prolifique, il a conçu une oeuvre importante, qui relève à la fois de plusieurs domaines philosophiques, de la sociologie, de la psychologie, de la biologie, ainsi que de la politique. Spencer commence sa carrière dans un esprit optimiste ; philosophiquement, il cherche à réconcilier théologie et science dans la notion de l’Inconnu ; politiquement, il prône un li...

  7. Contribución al estudio de biología reproductiva de un especie de bactris (palmae en el bosque de Galería (depto. Beni, Bolivia

    Directory of Open Access Journals (Sweden)

    1992-01-01

    Full Text Available CONTRIBUTION A L’ETUDE DE BIOLOGIE REPRODUCTIVE D’UNE ESPECE DE BACTRIS (PALMAE DE FORET DE GALERIE (DPT. BENI, BOLIVIE. Cette étude présente les résultats d’observations préliminaires sur la biologie de reproduction de Bactris bidentula Spruce des forêts-galerie situées dans les savanes des plaines de Moxos (Espíritu, département du Beni, Bolivie. Les observations réalisées ont permis d’obtenir des données sur les caractères végétatifs, la phénologie, l’anthèse et les agents pollinisateurs possibles. Se presentan los resultados obtenidos de observaciones preliminares sobre la biología reproductiva de Bactris bidentula Spruce del bosque de galería en las sabanas de los llanos de Moxos (Espíritu, Depto. Beni, Bolivia. Las observaciones realizadas permitieron registrar datos vegetativos, fenológicos, antesis y posibles polinizadores. CONTRIBUTION TO REPRODUCTIVE BIOLOGY OF A BACTRIS SPECIES (PALMAE IN A GALLERY FOREST (DEPART. OF BENI, BOLIVIA. Here we present results of preliminary observations on the reproductive biology of Bactris bidentula Spruce of gallery forest of the savanna of Llanos de Moxos (Espíritu, Dept. Beni, Bolivia. The observations registered information about vegetative features, phenology, anthesis, and possible pollinators.

  8. Biographer: web-based editing and rendering of SBGN compliant biochemical networks

    Science.gov (United States)

    Krause, Falko; Schulz, Marvin; Ripkens, Ben; Flöttmann, Max; Krantz, Marcus; Klipp, Edda; Handorf, Thomas

    2013-01-01

    Motivation: The rapid accumulation of knowledge in the field of Systems Biology during the past years requires advanced, but simple-to-use, methods for the visualization of information in a structured and easily comprehensible manner. Results: We have developed biographer, a web-based renderer and editor for reaction networks, which can be integrated as a library into tools dealing with network-related information. Our software enables visualizations based on the emerging standard Systems Biology Graphical Notation. It is able to import networks encoded in various formats such as SBML, SBGN-ML and jSBGN, a custom lightweight exchange format. The core package is implemented in HTML5, CSS and JavaScript and can be used within any kind of web-based project. It features interactive graph-editing tools and automatic graph layout algorithms. In addition, we provide a standalone graph editor and a web server, which contains enhanced features like web services for the import and export of models and visualizations in different formats. Availability: The biographer tool can be used at and downloaded from the web page http://biographer.biologie.hu-berlin.de/. The different software packages, including a server-indepenent version as well as a web server for Windows and Linux based systems, are available at http://code.google.com/p/biographer/ under the open-source license LGPL. Contact: edda.klipp@biologie.hu-berlin.de or handorf@physik.hu-berlin.de PMID:23574737

  9. Ways and means of coping with uncertainties of the relationship of the genetic blue print to protein structure and function in the cell

    Directory of Open Access Journals (Sweden)

    Helmreich Ernst JM

    2010-09-01

    Full Text Available Abstract As one of the disciplines of systems biology, proteomics is central to enabling the elucidation of protein function within the cell; furthermore, the question of how to deduce protein structure and function from the genetic readout has gained new significance. This problem is of particular relevance for proteins engaged in cell signalling. In dealing with this question, I shall critically comment on the reliability and predictability of transmission and translation of the genetic blue print into the phenotype, the protein. Based on this information, I will then evaluate the intentions and goals of today's proteomics and gene-networking and appraise their chances of success. Some of the themes commented on in this publication are explored in greater detail with particular emphasis on the historical roots of concepts and techniques in my forthcoming book, published in German: Von Molekülen zu Zellen. 100 Jahre experimentelle Biologie. Betrachtungen eines Biochemikers.

  10. Human DNA (cytosine-5)-methyltransferases: a functional and structural perspective for epigenetic cancer therapy.

    Science.gov (United States)

    Rondelet, Grégoire; Wouters, Johan

    2017-08-01

    Epigenetic modifications modulate chromatin states to regulate gene expression. Among them, DNA methylation and histone modifications play a crucial role in the establishment of the epigenome. In cancer, these epigenetic events may act in concert to repress tumor suppressor genes or promote oncogenic pathways. In the context of cancer initiation and progression, recruitment of DNA (cytosine-5)-methyltransferases to specific genomic regions is mainly mediated by histone epigenetic marks, transcription factors and co-regulators as part of a dynamic process. Herein, we will review these mechanisms and present state-of-the-art of DNA methylation, treatment and development of epigenetic cancer therapies targeting this epigenetic modification. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Protective effects of 4-methylcoumarins and related compounds as radical scavengers and chain-breaking antioxidants.

    Science.gov (United States)

    Kancheva, Vessela D; Slavova-Kazakova, Adriana K; Angelova, Silvia E; Singh, Suraj K; Malhotra, Shashwat; Singh, Brajendra K; Saso, Luciano; Prasad, Ashok K; Parmar, Virinder S

    2017-09-01

    The aim of this study is to determine, and to compare the protective effects of eight 4-methylcoumarins and four related compounds as radical scavengers and chain-breaking antioxidants. The main kinetic parameters of their radical scavenging activity (as % RSA, stoichiometry, n, and rate constants of reaction with DPPH radical, kRSA) and of chain breaking antioxidant activity (as antioxidant efficiency, PF and reactivity, ID), have been determined and discussed. The RSA study has been conducted at physiological temperature (37 °С) towards DPPH radical and the tested compounds are separated into three main groups: with strong activity (% RSA > 40%); with moderate activity (20%  40%) and with weak activity (% RSA Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  12. Functional effects of diphosphomimetic mutations at cAbl-mediated phosphorylation sites on Rad51 recombinase activity.

    Science.gov (United States)

    Alligand, Brendan; Le Breton, Magali; Marquis, Damien; Vallette, François; Fleury, Fabrice

    2017-08-01

    Homologous Recombination enables faithful repair of the deleterious double strand breaks of DNA. This pathway relies on Rad51 to catalyze homologous DNA strand exchange. Rad51 is known to be phosphorylated in a sequential manner on Y315 and then on Y54, but the effect of such phosphorylation on Rad51 function remains poorly understood. We have developed a phosphomimetic model in order to study all the phosphorylation states. With the purified phosphomimetic proteins we performed in vitro assays to determine the activity of Rad51. Here we demonstrate the inhibitory effect of the double phosphomimetic mutant and suggest that it may be due to a defect in nucleofilament formation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  13. Role of cardiolipin in stability of integral membrane proteins.

    Science.gov (United States)

    Musatov, Andrej; Sedlák, Erik

    2017-08-23

    Cardiolipin (CL) is a unique phospholipid with a dimeric structure having four acyl chains and two phosphate groups found almost exclusively in certain membranes of bacteria and of mitochondria of eukaryotes. CL interacts with numerous proteins and has been implicated in function and stabilization of several integral membrane proteins (IMPs). While both functional and stabilization roles of CL in IMPs has been generally acknowledged, there are, in fact, only limited number of quantitative analysis that support this function of CL. This is likely caused by relatively complex determination of parameters characterizing stability of IMPs and particularly intricate assessment of role of specific PLs such as CL in IMPs stability. This review aims to summarize quantitative findings regarding stabilization role of CL in IMPs reported up to now. Copyright © 2017 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.

  14. Inhibition of Na(+)/K(+)-ATPase by 5,6,7,8-tetrafluoro-3-hydroxy-2-phenylquinolin-4(1H)-one.

    Science.gov (United States)

    Šeflová, Jaroslava; Čechová, Petra; Biler, Michal; Hradil, Pavel; Kubala, Martin

    2017-07-01

    Na(+)/K(+)-ATPase (NKA) is an enzyme of crucial importance for all animal cells. We examined the inhibitory effects of halogenated phenylquinolinones on NKA. The 5,6,7,8-tetrafluoro-3-hydroxy-2-phenylquinolin-4(1H)-one (TFHPQ) was identified as an efficient NKA inhibitor with IC50 near 10 μM. The inhibition by TFHPQ is particularly efficient at higher concentrations of K(+), where NKA adopts the E2 conformation. The experimental observations are in a good agreement with the outcomes from molecular docking. We identified an energetically favourable TFHPQ binding site for the K(+)-bound NKA, which is located in the proximity of the cytoplasmic C-terminus. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  15. Apprendre collaborativement à partir d'animations simples ou multiples

    OpenAIRE

    Morand, Louiselle

    2009-01-01

    Alors que les théories de l'apprentissage multimédia sont bien établies et les études concernant l'apprentissage individuel nombreuses, les études portant sur l'utilisation du multimédia en situation d'apprentissage collaboratif assisté par ordinateur sont beaucoup moins représentées. En partant des études sur les animations multimédia, nous nous intéressons aux processus impliqués dans des situations collaboratives. Nous avons étudié le format de présentation d'une animation de biologie (ani...

  16. Uranium isotopes determination in urine samples using alpha spectrometry and ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Mychelle M.L.; Maihara, Vera A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Tine, Fernanda D.; Santos, Sandra M.C.; Bonifacio, Rodrigo L.; Taddei, Maria HelenaT. [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2015-07-01

    The action of determining the concentration of uranium isotopes in biological samples, 'in vitro' bioassay, is an indirect method for evaluating the incorporation and quantification of these radionuclides internally deposited. When incorporated, these radionuclides tend to be disposed through excretion, with urine being the main source of data because it can be easily collected and analyzed. The most widely used methods for determination of uranium isotopes ({sup 234}U, {sup 235}U and {sup 238}U) are Alpha Spectrometry and ICP-MS. This work presents a comparative study for the determination of uranium isotopes using these two methodologies in real samples from occupationally exposed workers. In order to validate the methodology, a sample of the intercomparison exercise organized by PROCORAD (Association pour la Promotion du Controle de Qualite des Analyses de Biologie Medicale em Radiotoxicologie) was used, and the results were statistically compared applying the Student's t-test. (author)

  17. Théorie de l’évolution et démographie : une histoire malheureuse

    OpenAIRE

    Harpending, Henry

    2014-01-01

    Introduction Très peu de gens doutent que les êtres humains soient issus du processus d’évolution darwinienne qui a engendré la diversité de la vie terrestre. L’évolution est le point d’ancrage de toute théorie en biologie, c’est un domaine de recherche actif et beaucoup est à présent connu sur les lois et les mécanismes de l’évolution. On comprend la stratégie reproductive des saumons, la taille de la portée chez les lézards, le dimorphisme sexuel des poissons et des orangs-outans, mais les ...

  18. Monsieur Tompkins s'explore lui-même aventures biologiques

    CERN Document Server

    Gamow, George

    1970-01-01

    L'éminent physicien George Gamow, aidé cette fois du biologiste Martynas Ycas, nous raconte, avec son talent et son humour bien connus, ce nouveau cycle des aventures de M. Tompkins. Après avoir suivi une série de conférences populaires, M. Tompkins fait la connaissance du conférencier, un professeur de physique de l'université, puis rencontre sa fille Maud et l'épouse. Il peut ainsi poursuivre en famille son initiation à la science. Guidé par son beau-père, il s'intéresse d'abord à la physique pure, puis à la biologie.

  19. Géographie des interfaces. Une nouvelle vision des territoires

    Directory of Open Access Journals (Sweden)

    Marie Redon

    2011-07-01

    Full Text Available Littéralement, une interface est une surface de séparation entre deux états distincts de la matière. Le terme, ayant cheminé de la physique à la biologie, et aussi désormais d’usage répandu en informatique. En géographie, l’usage du mot s’est développé dans les années 1980 et peut être défini comme un espace permettant la mise en relation de deux espaces/territoires différents, influencé par des échanges entre l’un et l’autre, et se distinguant par là-même des deux espaces contigus. Intégrant...

  20. Peroxisystem: harnessing systems cell biology to study peroxisomes.

    Science.gov (United States)

    Schuldiner, Maya; Zalckvar, Einat

    2015-04-01

    In recent years, high-throughput experimentation with quantitative analysis and modelling of cells, recently dubbed systems cell biology, has been harnessed to study the organisation and dynamics of simple biological systems. Here, we suggest that the peroxisome, a fascinating dynamic organelle, can be used as a good candidate for studying a complete biological system. We discuss several aspects of peroxisomes that can be studied using high-throughput systematic approaches and be integrated into a predictive model. Such approaches can be used in the future to study and understand how a more complex biological system, like a cell and maybe even ultimately a whole organism, works. © 2015 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  1. Dynamique et diversité des groupes bactériens ''non dominants'' dans les écosystèmes lacustres : cas des planctomycètes dans les lacs péri-alpins

    OpenAIRE

    Pollet, Thomas; Tadonléké, Remy; Humbert, Jean Francois

    2010-01-01

    Avec les récentes avancées méthodologiques en biologie moléculaire, les connaissances sur la diversité à la fois structurelle et fonctionnelle des communautés bactériennes dans les écosystèmes lacustres ont considérablement augmenté. Cependant, alors que la majorité de ces études étaient réalisées sur les groupes bactériens les plus représentés (Actino- et Protéo-bactéries), peu d’informations restent disponibles sur la dynamique et le rôle des groupes les moins abondants comme les Planctomyc...

  2. Stein-Schere-Papier

    Science.gov (United States)

    Springborn, Boris

    Wie gewinnt man im Spiel? Die Analyse von Strategien bei Gesellschaftsspielen ist ein Thema der mathematischen Spieltheorie. Mit ihren Methoden kann man aber nicht nur Spiele wie Schach oder Skat untersuchen, sondern auch verschiedenste Konfliktsituationen, bei denen das Schicksal jedes einzelnen Akteurs nicht nur vom eigenen Verhalten abhängt, sondern auch vom Verhalten der anderen, die ebenso wie er versuchen, ein für sie selbst möglichst positives Ergebnis herauszuschlagen. Die Spieltheorie hat großen Einfluss in den Wirtschaftswissenschaften. Auch in der Psychologie, Soziologie, Biologie und der Militärwissenschaft findet sie Anwendung. In der folgenden Aufgabe geht es aber tatsächlich um ein Spiel, und zwar um ein sehr einfaches, das jeder kennt. Trotzdem ist die Lösung nicht ganz einfach, und wer sie findet, hat schon die eine oder andere grundlegende Idee der Spieltheorie verstanden.

  3. GENOMIQUE ET PRODUCTION NON ALIMENTAIRE Acides gras d’intérêt industriel obtenus par génie génétique

    OpenAIRE

    Lessire René

    2002-01-01

    La caractérisation de mutants de plantes déficients pour la synthèse de lipides, l’évolution des techniques de la biologie moléculaire et le séquençage de la totalité du génome d’Arabidopsis thaliana sont des éléments qui ont rendu possible la manipulation par voie génétique de la composition en acides gras des huiles végétales. Parmi les enzymes impliquées dans la synthèse des acides gras et des triacylglycérols, les acyl-ACP thioestérases, les désaturases, les hydroxylases, les transacylase...

  4. Ein Mythos wird besichtigt. Le deuxième sexe von Simone de Beauvoir unter dem Mikroskop der Genderforschung

    Directory of Open Access Journals (Sweden)

    Lieselotte Steinbrügge

    2005-11-01

    Full Text Available Aus Anlass des 50jährigen Jubiläums der Erstausgabe von Das andere Geschlecht haben namhafte Wissenschaftlerinnen aus den Gebieten Philosophie, Biologie, Soziologie, Psychoanalyse, Geschichte und Literatur das fast tausendseitige Standardwerk des Feminismus einer akribischen Lektüre unterzogen und dabei versucht, jene Fragen zu rekonstruieren, auf die das Werk bei seinem Erscheinen im Jahr 1949 eine Antwort gab. Die zeitlos scheinende Formel von der Konstruiertheit weiblicher Identität sollte wieder in ihren ursprünglichen Entstehungszusammenhang gestellt, die Autorin aus der mythischen Ferne in die kritische Nähe gerückt werden. Diese kritischen Lektüren sind insgesamt gut dokumentiert und erlauben meines Wissens zum ersten Mal einen Einblick in die Beauvoirsche Werkstatt. Ein weiterer – ebenfalls von Ingrid Galster herausgegebener – Band dokumentiert die Reaktionen, die unmittelbar nach Erscheinen von Le deuxième sexe in der französischen Presse erschienen sind.

  5. Découvre les sciences avec les petits débrouillards 39 expériences faciles et amusantes

    CERN Document Server

    2006-01-01

    Comment plier des os sans les casser ? Peut-on enlever la rouille d’un vieux clou ? Est-ce facile de multiplier une plante ? Comment fabriquer un mini-geyser ? Un anneau de papier qui n’a qu’une seule face, est-ce possible ? Voilà quelques-unes des 40 énigmes et expériences que ce livre propose aux jeunes lecteurs curieux de comprendre le monde et les phénomènes qui les entourent. Une initiation aux grands principes de la physique, de la chimie et de la biologie, pour s’étonner et aussi épater ses amis ou sa famille.

  6. Numéro hors série 2004 "Encéphalopathies spongiformes transmissibles animales".Sommaire & Avant-propos

    OpenAIRE

    2004-01-01

    Ce numéro hors-série est consacré aux travaux sur les maladies à prions des animaux de ferme, menés à l’Inra en collaboration avec de nombreux organismes nationaux et internationaux. Il aborde de nombreuses facettes de la recherche sur ces agents et les maladies qu’ils occasionnent, tant sur le modèle tremblante que sur l’Encéphalopathie Spongiforme Bovine (ESB) : biologie de l’agent pathogène et notion de souche de prion, pathogénie de la maladie et résistance génétique, voies de transmissio...

  7. Models and Methods for Molecular Phylogenetics

    OpenAIRE

    Catanzaro, Daniele

    2008-01-01

    Un des buts principaux de la biologie évolutive et de la médecine moléculaire consiste à reconstruire les relations phylogénétiques entre organismes à partir de leurs séquences moléculaires. En littérature, cette question est connue sous le nom d’inférence phylogénétique et a d'importantes applications dans la recherche médicale et pharmaceutique, ainsi que dans l’immunologie, l’épidémiologie, et la dynamique des populations. L’accumulation récente de données de séquences d’ADN dans les bases...

  8. Fragile X mental retardation protein: A paradigm for translational control by RNA-binding proteins.

    Science.gov (United States)

    Chen, Eileen; Joseph, Simpson

    2015-07-01

    Translational control is a common mechanism used to regulate gene expression and occur in bacteria to mammals. Typically in translational control, an RNA-binding protein binds to a unique sequence in the mRNA to regulate protein synthesis by the ribosomes. Alternatively, a protein may bind to or modify a translation factor to globally regulate protein synthesis by the cell. Here, we review translational control by the fragile X mental retardation protein (FMRP), the absence of which causes the neurological disease, fragile X syndrome (FXS). Copyright © 2015 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  9. Gilles Bœuf, La biodiversité, de l’océan à la cité

    OpenAIRE

    Calla, Simon

    2014-01-01

    Cet ouvrage constitue la publication de la leçon inaugurale de Gilles Bœuf, professeur de biologie et président du Muséum national d’Histoire naturelle au Collège de France pour la chaire annuelle de Développement durable, Environnement, Énergie et Société. Il y présente un état des enjeux – tant scientifiques que pratiques – posés par la question de la biodiversité. Pour commencer, l’auteur propose un éclaircissement du concept de « biodiversité », qui a été créé en 1985 par l’écologue Walte...

  10. 2013 German refrigeration and air conditioning meeting. Proceedings; Deutsche Kaelte- und Klimatagung 2013. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    These proceedings cover the following main topics: cryoengineering - superconduction / energy storage; cryoapplications in biology and medicine; metrology; adsorption processes; condensation/evaporation; working fluids / simulation; ice production; plants and compressors; expansion and ejectors or recooling; use of cooling (passenger car air conditioning, supermarket); refrigerants; plant efficiency; emissions and legislation; air conditioning and use of heat pumps; air quality and control; building technology and block-type thermal power stations. [German] Dieser Tagungsbericht enthaelt folgende Themenschwerpunkte: Kryotechnik - Supraleitung/Energiespeicher; Kryoanwendungen in der Biologie und Medizin; Messtechnik; Adsorptionsprozesse; Kondensation/Verdampfung; Arbeitsfluide/Simulation; Eiserzeugung; Anlagen und Verdichter; Expansion und Ejektoren bzw. Rueckkuehlung; Kaelteanwendung (PKW-Klimatisierung; Supermarkt); Kaeltemittel; Anlageneffizienz; Emissionen und Gesetzgebung; Klimatechnik und Waermepumpenanwendung; Luftqualitaet und Regelung; Gebaeudetechnik und BHKW.

  11. [Implication of MAP kinases in obesity-induced inflammation and insulin resistance].

    Science.gov (United States)

    Ceppo, Franck; Jager, Jennifer; Berthou, Flavien; Giorgetti-Peraldi, Sophie; Cormont, Mireille; Bost, Fréderic; Tanti, Jean-François

    2014-01-01

    Insulin resistance is often associated with obesity and is a major risk factor for development of type 2 diabetes as well as cardiovascular and hepatic diseases. Insulin resistance may also increase the incidence or the aggressiveness of some cancers. Insulin resistance occurs owing to defects in insulin signaling in target tissues of this hormone. During the last ten years, it became evident that the chronic low-grade inflammatory state that develops during obesity plays an important role in insulin resistance development. Indeed, inflammatory cytokines activate several signaling pathways that impinge on the insulin signaling pathway. Among them, this review will focus on the implication of the MAP kinases JNK and ERK1/2 signaling in the development of insulin signaling alterations and will discuss the possibility to target these pathways in order to fight insulin resistance. © Société de Biologie, 2014.

  12. [Paul Bert, scientist and politician].

    Science.gov (United States)

    Rostène, William

    2006-01-01

    Paul Bert worked with Claude Bernard, one of the leading physiologists of the 19th century. In his laboratory at the Collège de France in Paris, Paul Bert carried out fascinating experiments in particular on respiratory processes, leading him to publish "La pression barométrique" in 1878. In this book are recalled his discovery of oxygen pressure decrease with altitude, divers diseases, the improved safety protocols in hyperbaric conditions, and the first development of gas anaesthetics for surgery. He was the third President of the Société de Biologie. Paul Bert was also a politician with strong convictions. Minister of Education under Gambetta's short term government, he initiated the fight for social equality and secular education and became one of the most prestigious figures of the developing socialist party. He received many distinctions and was given a state funeral.

  13. « Se sentir vivant » : quels enjeux d’éducation biologique ?

    Directory of Open Access Journals (Sweden)

    Coquidé Maryline

    2015-01-01

    Full Text Available Avec un point de vue didactique, je discute des enjeux d’éducation biologique de « se sentir vivant ». Je distingue des perspectives d’enseignement de la biologie avec ceux d’éducation biologique, en reprenant ce que nos collègues allemands désignent par le concept Bildung. Je centre ensuite ma réflexion sur le corps et l’expérience vécue, la perception et la signification, en privilégiant un point de vue phénoménologique. Cette analyse est mise à l’épreuve selon trois approches du vivant: le vivant comme réduction, comme extension puis comme relations.

  14. La validation du substrat professionnel dans La proie de Michael Crichton (Prey, US, 2002)

    OpenAIRE

    Genty, Stéphanie

    2010-01-01

    La FASP constitue un genre de fiction spécifique de par son contenu « spécialisé » ou « professionnel », contenu qui côtoie des éléments de fiction au sein d’une logique de thriller. Mais comment évaluer l’authenticité de ce contenu, surtout dans un objectif pédagogique, si l’on est non-spécialiste ? Une issue évidente est le recours aux spécialistes eux-mêmes. Nous avons décidé de mener une enquête auprès de collègues scientifiques travaillant dans la nanotechnologie, la biologie et l’intell...

  15. Tests génétiques. Questions scientifiques, médicales et sociétales

    OpenAIRE

    Ameisen, Jean-Claude; Cambien, Francois; Dervaux, Benoit; Douay, Sophie; Gaudillière, Jean-Paul; Julian-Reynier, Claire; Rabeharisoa, Vololona; Roussey, Michel; Sobol, Hagay; Verstuyft, Celine

    2008-01-01

    Les progrès de la biologie moléculaire et les avancées des biotechnologies ont contribué à une augmentation rapide de l' offre de tests génétiques dans le domaine des maladies héréditaires. En France, près de 1 000 mala-dies héréditaires peuvent désormais faire l' objet d'un test diagnostique effectué dans le cadre d'une consultation de conseil génétique. Un programme de dépistage néonatal de cinq maladies génétiques existe depuis plu-sieurs années. Tous ces tests dans le domaine médical sont...

  16. Post-treatment of hydrocarbon-burdened effluents by means of adsorption to bentonites; Nachbehandlung kohlenwasserstoffhaltiger Abwaesser durch Adsorption an Bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Breuker, F. [Fachhochschule Muenster, Burgsteinfurt (Germany). Fachbereich Chemieingenieurwesen; Nussbaumer, A. [Edelhoff Entsorgung West GmbH und Co., Hagen (Germany)

    1996-06-01

    During chemical/physical treatment of liquid toxic waste, e.g. emulsions or oil/water mixtures, a separate process stage of hydrocarbon adsorption may be necessary after hydroxide precipitation of the metal salts as soon as the metal freight is reduced by the application of anaerobic biological processes. This is possible, in principle, with the aid of bentonites. Instead of the discontinuous process investigated here, a continuous process would be better suited in practice. (orig.) [Deutsch] Bei der chemisch-physikalischen Behandlung fluessiger Sonderabfaelle wie Emulsionen oder Oel-Wasser-Gemischen kann nach einer Hydroxidfaellung der Metallsalze ein separates Verfahren zur Adsorption von Kohlenwasserstoffen erforderlich sein, sobald die Metallfracht durch den Einsatz einer anaeroben Biologie reduziert wird. Dies ist durch den Einsatz von Bentoniten grundsaetzlich moeglich. Anstelle der hier untersuchten diskontinuierlichen Verfahrensweise waere fuer die betriebliche Praxis ein kontinuierliches Verfahren guenstiger. (orig.)

  17. Mutation d’un cours de biostatistiques : évaluation d’un dispositif d’autoformation sur le Web

    Directory of Open Access Journals (Sweden)

    Grégoire Vincke

    2010-01-01

    Full Text Available Les biostatistiques représentent une discipline à l’intersection des mathématiques et de la biologie. Son.enseignement.relativement.récent.requiert.encore de nombreux ajustements en vue d’être adapté à son public, généralement peu enclin à la formulation mathématique et très sceptique quant à son utilité. Le dispositif présenté ici expérimente les potentialités du multimédia et l’interactivité du Web 2.0 dans le but de rendre les concepts importants plus abordables et les étudiants plus autonomes. Nous insisterons particulièrement sur les mesures développées pour optimiser l’auto-apprentissage via le Web et sur les modifications du contrat didactique qui en ont découlé.

  18. Using lipidomics for expanding the knowledge on lipid metabolism in plants.

    Science.gov (United States)

    Tenenboim, Hezi; Burgos, Asdrubal; Willmitzer, Lothar; Brotman, Yariv

    2016-11-01

    Lipids are a crucial and diverse class of biomolecules. Their structural heterogeneity in plants is staggering, and many aspects of plant life are manifested and mediated by lipids. Recent advances in metabolomic and lipidomic technologies and analysis have immensely increased our knowledge of the plant lipidome, its biosynthesis, regulation, adaptation, remodeling, functions, roles, and interactions. Here we review the recent literature and trends in lipidomics, and discuss specific issues pertaining to lipidomic research in plants, and how lipidomics has helped elucidate key issues in plant cell biology, immunity, response to stress, evolution, crop enhancement-to name but a few. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  19. RETRACTED: Bone morphogenetic protein 4 (BMP4) induces buffalo (Bubalus bubalis) embryonic stem cell differentiation into germ cells.

    Science.gov (United States)

    Shah, Syed Mohmad; Saini, Neha; Ashraf, Syma; Singh, Manoj Kumar; Manik, Radhey Sham; Singla, Suresh Kumar; Palta, Prabhat; Chauhan, Manmohan Singh

    2015-12-01

    This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Problems related to images published in this paper in Figure 12 were brought to the authors' attention. Unfortunately this figure contains duplicate images for ESC controls for VASA, GDF9, and ZP4, which display identical patterns superimposed on varying intensities of background. Therefore, the authors retract the paper with the agreement of the editors and deeply regret this situation and apologize for any inconvenience to the editors and readers of Biochimie. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. Claude Debru , Le Possible et les biotechnologies, avec la collaboration de Pascal Nouvel, Paris, PUF, 2003, 440 p.

    Directory of Open Access Journals (Sweden)

    Stéphane Callens

    2003-11-01

    Full Text Available L’ouvrage de Claude Debru et de Pascal Nouvel s’inscrit dans une lignée d’ouvrage retraçant l’histoire du génie génétique, à la suite d’un premier ouvrage qui a été celui de Paul Rabinow. Il peut être vu comme une mise à jour de la dernière référence parue, celle de H. Gottweis (Gottweis H., Governing Molecules. The discursive politics of Genetic Engineering in Europe and the United States, Cambridge: MIT Press. Des travaux très récents en thérapie génique et biologie moléculaire y sont comm...

  1. L’INVASION DU RÉSEAU HYDROGRAPHIQUE FRANÇAIS PAR LES MOLLUSQUES CORBICULA SPP. MODALITÉ DE COLONISATION ET RÔLE PRÉPONDÉRANT DES CANAUX DE NAVIGATION.

    Directory of Open Access Journals (Sweden)

    BRANCOTTE V.

    2002-04-01

    Full Text Available Originaire d’Asie et d’Afrique, Corbicula a colonisé la plupart des bassins hydrographiques européens depuis 1980. A la faveur de la découverte de nouvelles stations, les auteurs mettent en évidence l’importance du rôle des canaux de navigation dans la propagation du mollusque, par la mise en connexion des bassins versants et l’existence d’un milieu particulièrement favorable à la biologie de l’espèce. Corbicula a pénétré en France par au moins sept axes différents, parmi lesquels le Rhin joue un rôle prépondérant.

  2. Control of adipogenesis by oxylipins, GPCRs and PPARs.

    Science.gov (United States)

    Barquissau, Valentin; Ghandour, Rayane A; Ailhaud, Gérard; Klingenspor, Martin; Langin, Dominique; Amri, Ez-Zoubir; Pisani, Didier F

    2017-05-01

    Oxylipins are bioactive metabolites derived from the oxygenation of ω3 and ω6 polyunsaturated fatty acids, triggered essentially by cyclooxygenase and lipoxygenase activities. Oxylipins are involved in the development and function of adipose tissue and their productions are strictly related to diet quality and quantity. Oxylipins signal via cell surface membrane (G Protein-coupled receptors) and nuclear receptors (peroxisome proliferator-activated receptors), two pathways playing a pivotal role in adipocyte biology. In this review, we made an attempt to cover the available knowledge about synthesis and molecular function of oxylipins known to modulate adipogenesis, adipocyte function and phenotype conversion, with a focus on their interaction with peroxisome proliferator-activated nuclear receptor family. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  3. Repeated short climatic change affects the epidermal differentiation program and leads to matrix remodeling in a human organotypic skin model

    Directory of Open Access Journals (Sweden)

    Boutrand LB

    2017-02-01

    Full Text Available Laetitia-Barbollat Boutrand,1 Amélie Thépot,2 Charlotte Muther,3 Aurélie Boher,2 Julie Robic,4 Christelle Guéré,4 Katell Vié,4 Odile Damour,5 Jérôme Lamartine1,3 1Departement de Biologie, Université Claude Bernard Lyon I, 2LabSkinCreations, 3CNRS UMR5305, Laboratoire de Biologie Tissulaire et d’Ingénierie Thérapeutique (LBTI, Lyon, 4Laboratoires Clarins, Cergy-Pontoise, 5Banque de Tissus et Cellules, Hospices Civiles de Lyon, Lyon, France Abstract: Human skin is subject to frequent changes in ambient temperature and humidity and needs to cope with these environmental modifications. To decipher the molecular response of human skin to repeated climatic change, a versatile model of skin equivalent subject to “hot–wet” (40°C, 80% relative humidity [RH] or “cold–dry” (10°C, 40% RH climatic stress repeated daily was used. To obtain an exhaustive view of the molecular mechanisms elicited by climatic change, large-scale gene expression DNA microarray analysis was performed and modulated function was determined by bioinformatic annotation. This analysis revealed several functions, including epidermal differentiation and extracellular matrix, impacted by repeated variations in climatic conditions. Some of these molecular changes were confirmed by histological examination and protein expression. Both treatments (hot–wet and cold–dry reduced the expression of genes encoding collagens, laminin, and proteoglycans, suggesting a profound remodeling of the extracellular matrix. Strong induction of the entire family of late cornified envelope genes after cold–dry exposure, confirmed at protein level, was also observed. These changes correlated with an increase in epidermal differentiation markers such as corneodesmosin and a thickening of the stratum corneum, indicating possible implementation of defense mechanisms against dehydration. This study for the first time reveals the complex pattern of molecular response allowing

  4. New structure–activity relationships of chalcone inhibitors of breast cancer resistance protein: polyspecificity toward inhibition and critical substitutions against cytotoxicity

    Directory of Open Access Journals (Sweden)

    Rangel LP

    2013-09-01

    Full Text Available Luciana Pereira Rangel,1,2,* Evelyn Winter,1,3,* Charlotte Gauthier,1 Raphaël Terreux,4 Louise D Chiaradia-Delatorre,5 Alessandra Mascarello,5 Ricardo J Nunes,5 Rosendo A Yunes,5 Tania B Creczynski-Pasa,3 Sira Macalou,1 Doriane Lorendeau,1 Hélène Baubichon-Cortay,1 Antonio Ferreira-Pereira,2 Attilio Di Pietro11Equipe Labellisée Ligue 2013, BMSSI UMR 5086 CNRS/Université Lyon 1, Institut de Biologie et Chimie des Protéines, Lyon, France; 2Department of General Microbiology, Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 3Department of Pharmaceutical Sciences, PPGFAR, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil; 4Equipe BISI, BMSSI UMR 5086 CNRS/Université Lyon 1, Institut de Biologie et Chimie des Protéines, Lyon, France; 5Department of Chemistry, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil*These authors contributed equally to this workAbstract: Adenosine triphosphate-binding cassette subfamily G member 2 (ABCG2 plays a major role in cancer cell multidrug resistance, which contributes to low efficacy of chemotherapy. Chalcones were recently found to be potent and specific inhibitors, but unfortunately display a significant cytotoxicity. A cellular screening against ABCG2-mediated mitoxantrone efflux was performed here by flow cytometry on 54 chalcone derivatives from three different series with a wide panel of substituents. The identified leads, with submicromolar IC50 (half maximal inhibitory concentration values, showed that the previously identified 2'-OH-4',6'-dimethoxyphenyl, as A-ring, could be efficiently replaced by a 2'-naphthyl group, or a 3',4'-methylenedioxyphenyl with lower affinity. Such a structural variability indicates polyspecificity of the multidrug transporter for inhibitors. At least two methoxyl groups were necessary on B-ring for optimal inhibition, but substitution at positions 3, 4, and 5 induced cytotoxicity

  5. Histoire d'une cité scientifique le campus du CNRS à Gif-sur-Yvette (1946-2016)

    CERN Document Server

    2016-01-01

    L'histoire du campus de Gif-sur-Yvette, cité scientifique de renommée internationale, commence en 1946, à l'heure de la reconstruction de la recherche française, ajuste après le deuxième conflit mondial. L'histoire du campus de Gif-sur-Yvette, cité scientifique de renommée internationale, commence en 1946, à l'heure de la reconstruction de la recherche française, ajuste après le deuxième conflit mondial. À cette époque, l'on cherche à favoriser l'émergence d'études nouvelles, à soutenir les travaux fondamentaux sans s'interdire de réfléchir à leurs applications, ou encore à stimuler l'interdisciplinarité. L'acquisition du domaine par le CNRS reflète alors l'ambition de son directeur, Frédéric Joliot-Curie, de refonder la Recherche scientifique et de restaurer son rayonnement. Depuis, le campus de Gif-sur-Yvette a connu une formidable aventure, aussi bien humaine que scientifique. Pionnier dans de nombreux domaines, en biologie, en chimie mais aussi en sciences du climat et de l'env...

  6. Paraboles et catastrophes

    CERN Document Server

    Thom, René

    1983-01-01

    René Thom, mathématicien français, membre de l'Académie des Sciences, s'est vu décerner en 1958 la médaille Field, équivalent du Prix Nobel en mathématiques, pour ses créations intellectuelles, la " théorie des catastrophes ", regard nouveau sur toutes les transformations qui adviennent de manière brusque, imprévisible, dramatique. Dans ces entretiens qui vont de la mathématique à l'embryologie, de la linguistique à l'anthropologie et à l'histoire, René Thom expose les grandes lignes de la théorie des catastrophes et passe en revue, avec un esprit à la fois critique et passionné, les grands thèmes scientifiques de notre époque, de la physique atomique à la biologie moléculaire, du " progrès " scientifique et technologique aux connexions complexes entre la société et la science. " Ce petit livre est une extraordinaire réussite en vulgarisation ". (Jean Largeault)

  7. [Memory processes and executive functioning: novel trends for research].

    Science.gov (United States)

    Collette, Fabienne; Angel, Lucie

    2015-01-01

    The existence of processes common to memory systems and executive functioning was evidenced by studies in the domain of cerebral neuroimaging, individual differences (mainly in normal aging) and, to a lesser extent, neuropsychology. Executive functioning depends on a large antero-posterior brain network, some regions of which (the middle dorsolateral and ventrolateral cortex, the dorsal anterior cingulate cortex) are involved in a series of executive processes, but also in encoding and retrieval of information in episodic memory and short-term memory. A consequence of lesions in frontal areas is to impair strategical organization of the information to-be-processed (an executive process) and thus leads to a lower memory capacity in frontal patients. Moreover, executive abilities will influence both memory efficiency and the associated brain networks even in people without brain pathology. These data attest to the importance of the relationships between executive and memory processes for an optimal cognitive functioning. Recent advances in neuroimaging and electrophysiology data acquisition and analysis techniques should allow us to better determine and understand the fashion in which these relationships work. © Société de Biologie, 2016.

  8. Brown and brite adipocytes: Same function, but different origin and response.

    Science.gov (United States)

    Chu, Dinh-Toi; Gawronska-Kozak, Barbara

    2017-07-01

    Inducing brown adipocytes in white adipose tissues is a promising target to combat obesity and its related disorders in human beings. This goal has been especially encouraged by new important discoveries of human brown adipose tissues. The accumulating evidence confirms the presence of active brown adipocytes, not only in newborns, but also in adult humans. In rodents, there are two populations of the Ucp1-expressing adipocytes with well characterized-thermogenic functions, classical interscapular brown adipocytes and brite/beige adipocytes (brown adipocytes that are induced in white adipose tissues). Importantly, the anatomical localization, gene expression profiling and functional characterization of Ucp1-expressing fat cells indicates brite and brown adipocytes coexist in human beings. Therefore, the research directions of brown and brite adipogenesis provide lead to potential new therapies to fight obesity and its related metabolic diseases in human being. The objectives of this review are (1) to discuss the fate of primary adipocytes based on tissue origins, and (2) to discuss mechanisms of brown and brite adipogenesis which could lead to their different responses to browning reagents. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  9. Contribution of the carbohydrate-binding ability of Vatairea guianensis lectin to induce edematogenic activity.

    Science.gov (United States)

    Marques, Gabriela F O; Osterne, Vinicius J S; Almeida, Livia M; Oliveira, Messias V; Brizeno, Luiz A C; Pinto-Junior, Vanir R; Santiago, Mayara Q; Neco, Antonio H B; Mota, Mario R L; Souza, Luiz A G; Nascimento, Kyria S; Pires, Alana F; Cavada, Benildo S; Assreuy, Ana M S

    2017-09-01

    Vatairea guianensis lectin (VGL), Dalbergiae tribe, is a N-acetyl-galactosamine (GalNAc)/Galactose (Gal) lectin previously purified and characterized. In this work, we report its structural features, obtained from bioinformatics tools, and its inflammatory effect, obtained from a rat paw edema model. The VGL model was obtained by homology with the lectin of Vatairea macrocarpa (VML) as template, and we used it to demonstrate the common characteristics of legume lectins, such as the jellyroll motif and presence of a metal-binding site in the vicinity of the carbohydrate-recognition domain (CRD). Protein-ligand docking revealed favorable interactions with N-acetyl-d-galactosamine, d-galactose and related sugars as well as several biologically relevant N- and O-glycans. In vivo testing of paw edema revealed that VGL induces edematogenic effect involving prostaglandins, interleukins and VGL CRD. Taken together, these data corroborate with previous reports showing that VGL interacts with N- and/or O-glycans of molecular targets, particularly in those presenting galactosides in their structure, contributing to the lectin inflammatory effect. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Membrane raft domains and remodeling in aging brain.

    Science.gov (United States)

    Colin, Julie; Gregory-Pauron, Lynn; Lanhers, Marie-Claire; Claudepierre, Thomas; Corbier, Catherine; Yen, Frances T; Malaplate-Armand, Catherine; Oster, Thierry

    2016-11-01

    Lipids are the fundamental structural components of biological membranes. For a long time considered as simple barriers segregating aqueous compartments, membranes are now viewed as dynamic interfaces providing a molecular environment favorable to the activity of membrane-associated proteins. Interestingly, variations in membrane lipid composition, whether quantitative or qualitative, play a crucial role in regulation of membrane protein functionalities. Indeed, a variety of alterations in brain lipid composition have been associated with the processes of normal and pathological aging. Although not establishing a direct cause-and-effect relationship between these complex modifications in cerebral membranes and the process of cognitive decline, evidence shows that alterations in membrane lipid composition affect important physicochemical properties notably impacting the lateral organization of membranes, and thus microdomains. It has been suggested that preservation of microdomain functionality may represent an effective strategy for preventing or decelerating neuronal dysfunction and cerebral vulnerability, processes that are both aggravated by aging. The working hypothesis developed in this review proposes that preservation of membrane organization, for example, through nutritional supplementation of docosahexaenoic acid, could prevent disturbances in and preserve effective cerebral function. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Brain lipoprotein lipase as a regulator of energy balance.

    Science.gov (United States)

    Cruciani-Guglielmacci, Céline; Magnan, Christophe

    2017-07-24

    The central nervous system is an essential actor in the control of the energy balance. Indeed, many signals of nervous (vagal afferent for example) or circulating (hormone, nutrients) origin converge towards the brain to inform it permanently of the energetic status of the organism. In turn, the brain sends information to the periphery (sympathetic vagal balance, thyroid or corticotropic axis) which allows a fine regulation of the energy fluxes by acting on the hepatic glucose production, the secretion of the pancreatic hormones (glucagon, insulin) or food behavior. Among the nutrients, increasing amount of data assigns a signal molecule role to lipids such as fatty acids. These fatty acids may originate from the bloodstream but may also be the product of the hydrolysis of lipoproteins such as chylomicrons or VLDLs. Indeed, the identification of lipoprotein lipase (LPL) in the brain has led to the hypothesis that the LPL-dependent degradation of TG-enriched particles, and the addition of fatty acids, as informative molecules, to sensitive cells (neurons and/or astrocytes), plays a key role in maintaining the energy balance at equilibrium. Other lipases could also participate in these regulatory mechanisms. This review will summarize the state of the art and open up perspectives. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  12. Development of a thermal-stable structure-switching cocaine-binding aptamer.

    Science.gov (United States)

    Shoara, Aron A; Reinstein, Oren; Borhani, Okty Abbasi; Martin, Taylor R; Slavkovic, Sladjana; Churcher, Zachary R; Johnson, Philip E

    2017-08-21

    We have developed a new cocaine-binding aptamer variant that has a significantly higher melt temperature when bound to a ligand than the currently used sequence. Retained in this new construct is the ligand-induced structure-switching binding mechanism that is important in biosensing applications of the cocaine-binding aptamer. Isothermal titration calorimetry methods show that the binding affinity of this new sequence is slightly tighter than the existing cocaine-binding aptamer. The improved thermal performance, a Tm increase of 4 °C for the cocaine-bound aptamer and 9 °C for the quinine-bound aptamer, was achieved by optimizing the DNA sequence in stem 2 of the aptamer to have the highest stability based on the nearest neighbor thermodynamic parameters and confirmed by UV and fluorescence spectroscopy. The sequences in stem 1 and stem 3 were unchanged in order to retain the structure switching and ligand binding functions. The more favorable thermal stability characteristics of the OR3 aptamer should make it a useful construct for sensing applications employing the cocaine-binding aptamer system. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  13. Addition of thiols to the double bond of dipeptide C-terminal dehydroalanine as a source of new inhibitors of cathepsin C.

    Science.gov (United States)

    Lenartowicz, Paweł; Makowski, Maciej; Oszywa, Bartosz; Haremza, Kinga; Latajka, Rafał; Pawełczak, Małgorzata; Kafarski, Paweł

    2017-08-01

    Addition of thiols to double bond of glycyl-dehydroalanine and phenyl-dehydroalanine esters provided micromolar inhibitors of cathepsin C. The structure-activity studies indicated that dipeptides containing N-terminal phenylalanine exhibit higher affinity towards the enzyme. A series of C-terminal S-substituted cysteines are responsible for varying interaction with S1 binding pocket of cathepsin C. Depending on diastereomer these compounds most likely act as slowly reacting substrates or competitive inhibitors. This was proved by TLC analysis of the medium in which interaction of methyl (S)-phenylalanyl-(R,S)-(S-adamantyl)cysteinate (7i) with the enzyme was studied. Molecular modeling enabled to establish their mode of binding showed that S2 pocket is long and narrow and accommodates phenyl group of phenylalanine while significantly spacious sites located at the surface of the enzyme (one of them being S1 pocket) bind the adamantyl moiety oriented in different direction for each stereoisomer. Finally replacement of carboxymethyl moiety of methyl (S)-phenylalanyl-(R,S)-(S-phenyl)cysteinate (7c) with nitrile group provided about 650-times more potent inhibitor of cathepsin C indicating that the studied C-terminal S-substituted cysteines are good activity probes for S1 binding pocket of this enzyme. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  14. Circadian control of metabolism and pathological consequences of clock perturbations.

    Science.gov (United States)

    Mayeuf-Louchart, Alicia; Zecchin, Mathilde; Staels, Bart; Duez, Hélène

    2017-08-02

    Most organisms have developed an autonomous time-keeping system that generates self-sustained daily fluctuations in behavior and physiological processes. These biological clocks are reset every day by light to adjust physiology to the day/night cycle generated by the rotation of the Earth. Clocks present in organs involved in glucose and lipid metabolism such as the liver, muscle, adipose tissue and pancreas are also reset by feeding cues which permits the local integration of systemic and nutritional signals to switch fuel production and utilization according to the feeding/fasting cycle. However, derangements in this finely tuned system can be induced by extended light exposure, 24/7 food availability and altered food intake patterns, repeated jet-lag and shift-working, promoting metabolic imbalances ranging from body weight gain to the development of insulin resistance and liver diseases. Here, we review recent findings on the link between the clock and metabolic fluxes to maintain whole-body homeostasis, and what clock disruption in mice has revealed about the role of the clock in metabolic regulation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  15. Structural studies of amyloid-β peptides: Unlocking the mechanism of aggregation and the associated toxicity.

    Science.gov (United States)

    Aleksis, Rihards; Oleskovs, Filips; Jaudzems, Kristaps; Pahnke, Jens; Biverstål, Henrik

    2017-09-01

    Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases worldwide. Formation of amyloid plaques consisting of amyloid-β peptides (Aβ) is one of the hallmarks of AD. Several lines of evidence have shown a correlation between the Aβ aggregation and the disease development. Extensive research has been conducted with the aim to reveal the structures of the neurotoxic Aβ aggregates. However, the exact structure of pathological aggregates and mechanism of the disease still remains elusive due to complexity of the occurring processes and instability of various disease-relevant Aβ species. In this article we review up-to-date structural knowledge about amyloid-β peptides, focusing on data acquired using solution and solid state NMR techniques. Furthermore, we discuss implications from these structural studies on the mechanisms of aggregation and neurotoxicity. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Kinetic properties of the mitochondrial F1FO-ATPase activity elicited by Ca(2+) in replacement of Mg(2).

    Science.gov (United States)

    Nesci, Salvatore; Trombetti, Fabiana; Ventrella, Vittoria; Pirini, Maurizio; Pagliarani, Alessandra

    2017-09-01

    The mitochondrial F-ATPase can be activated either by the classical cofactor Mg(2+) or, with lower efficiency, by Ca(2+). The latter may play a role when calcium concentration rises in mitochondria, a condition associated with cascade events leading to cell death. Common and distinctive features of these differently activated mitochondrial ATPases were pointed out in swine heart mitochondria. When Ca(2+) replaces the natural cofactor Mg(2+), the enzyme responsiveness to the transmembrane electrochemical gradient and to the classical F-ATPase inhibitors DCCD and oligomycin as well as the oligomycin sensitivity loss by thiol oxidation, are maintained. Consistently, the two mitochondrial ATPases apparently share the F1FO complex basic structure and mechanism. Peculiar cation-dependent properties, which may affect the F1 catalytic mechanism and/or the FO proton binding site features, may be linked to a different physiological role of the mitochondrial Ca-activated F-ATPase with respect to the Mg-activated F-ATPase. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  17. Identification of two frataxin isoforms in Zea mays: Structural and functional studies.

    Science.gov (United States)

    Buchensky, Celeste; Sánchez, Manuel; Carrillo, Martin; Palacios, Oscar; Capdevila, Mercè; Domínguez-Vera, Jose M; Busi, Maria V; Atrian, Sílvia; Pagani, Maria A; Gomez-Casati, Diego F

    2017-09-01

    Frataxin is a ubiquitous protein that plays a role in Fe-S cluster biosynthesis and iron and heme metabolism, although its molecular functions are not entirely clear. In non-photosynthetic eukaryotes, frataxin is encoded by a single gene, and the protein localizes to mitochondria. Here we report the presence of two functional frataxin isoforms in Zea mays, ZmFH-1 and ZmFH-2. We confirmed our previous findings regarding plant frataxins: both proteins have dual localization in mitochondria and chloroplasts. Physiological, biochemical and biophysical studies show some differences in the expression pattern, protection against oxidants and in the aggregation state of both isoforms, suggesting that the two frataxin homologs would play similar but not identical roles in plant cell metabolism. In addition, two specific features of plant frataxins were evidenced: their ability to form dimers and their tendency to undergo conformational change under oxygen exposure. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  18. Exploring the aryl esterase catalysis of paraoxonase-1 through solvent kinetic isotope effects and phosphonate-based isosteric analogues of the tetrahedral reaction intermediate.

    Science.gov (United States)

    Bavec, Aljoša; Knez, Damijan; Makovec, Tomaž; Stojan, Jure; Gobec, Stanislav; Goličnik, Marko

    2014-11-01

    Although a recent study of Debord et al. in Biochimie (2014; 97:72-77) described the thermodynamics of the catalysed hydrolysis of phenyl acetate by human paraoxonase-1, the mechanistic details along the reaction route of this enzyme remain unclear. Therefore, we briefly present the solvent kinetic isotope effects on the phenyl acetate esterase activity of paraoxonase-1 and its inhibition with the phenyl methylphosphonate anion, which is a stable isosteric analogue that mimics the high-energy tetrahedral intermediate on the hydroxide-promoted hydrolysis pathway. The data show normal isotope effects, while proton inventory analysis indicates that two protons contribute to the kinetic isotope effect. Coherently, moderate competitive inhibition with the phenyl methylphosphonate anion reveals that the rate-limiting transition state suboptimally resembles the tetrahedral intermediate. The implications of these findings can be attributed to two possible reaction mechanisms that might occur during the paraoxonase-1-catalysed hydrolysis of phenyl acetate. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  19. Characterization of linear mimetic peptides of Interleukin-22 from dissection of protein interfaces.

    Science.gov (United States)

    La Manna, Sara; Scognamiglio, Pasqualina Liana; Di Natale, Concetta; Leone, Marilisa; Mercurio, Flavia Anna; Malfitano, Anna Maria; Cianfarani, Francesca; Madonna, Stefania; Caravella, Sergio; Albanesi, Cristina; Novellino, Ettore; Marasco, Daniela

    2017-07-01

    Interleukin-22 (IL-22) belongs to the family of IL-10 cytokines and is involved in a wide number of human diseases, including inflammatory disorders and cancer pathology. The ligand-receptor complex IL-22/IL-22R plays a key role in several pathways especially in the regulation and resolution of immune responses. The identification of novel compounds able to modulate IL-22/IL-22R complex could open the route to new therapeutic strategies in multiple human diseases. In this study, we designed and characterized IL-22 derived peptides at protein interface regions: several sequences revealed able to interfere with the protein complex with IC50 in the micromolar range as evaluated through Surface Plasmon Resonance (SPR) experiments. Their conformational characterization was carried out through Circular Dichroism (CD) and Nuclear Magnetic Resonance (NMR) spectroscopies, shedding new light into the features of IL-22 fragments and on structural determinants of IL-22/IL-22R1 recognition. Finally, several peptides were tested on human keratinocyte cultures for evaluating their ability to mimic the activation of molecular pathways downstream to IL-22R in response to IL-22 binding. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. Peroxynitrite-modified histone as a pathophysiological biomarker in autoimmune diseases.

    Science.gov (United States)

    Khan, Md Asad; Alam, Khursheed; Zafaryab, Md; Rizvi, M Moshahid A

    2017-09-01

    Under physiological conditions, reactive nitrogen and oxygen species are produced continuously. However, excess of these radicals may damage biomolecules like lipids, proteins and nucleic acids. These reactive species have been implicated in many disease conditions including acute/chronic inflammation, rheumatoid arthritis (RA), neurodegenerative diseases and systemic lupus erythematosus (SLE). Peroxynitrite, an oxidant and nitrating molecule, formed in in vivo, when nitric oxide reacts with superoxide radical. The abnormal levels of nitrotyrosine detected in tissues affected by autoimmune diseases have been attributed to peroxynitrite-mediated enhanced nitration of tyrosine residues in proteins. The chromosomal histone proteins are conserved and weak immunogens. However, they exhibit strong immunogenicity after nitration. Rabbits challenged with peroxynitrite-modified histone induce high titre antibodies, indicating that peroxynitrite modification generated immunogenic epitopes. The preferential binding of peroxynitrite-modified histones by autoantibodies derived from SLE and RA sera shows oxidatively and nitrated modified histones involve in the initiation and progression of autoimmune diseases. This review article presents the literature review of the physicochemical and immunological studies on histone proteins modified with peroxynitrite with an objective of the possible role of oxidatively nitrated histones in the initiation/progression of autoimmune inflammatory diseases. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Role of MicroRNAs in Type 2 Diabetes and Associated Vascular Complications.

    Science.gov (United States)

    Banerjee, Joyita; Nema, Vijay; Dhas, Yogita; Mishra, Neetu

    2017-08-01

    Type 2 diabetes mellitus (T2DM) has become a major health threat worldwide. MicroRNAs (miRNAs) are a group of non-coding RNAs known to regulate various biological processes including the pathogenesis of T2DM. Recent studies have pointed out that specific miRNAs play a critical role in controlling β cell activities and the development of diabetic vascular complications. Their association with the disease pathogenesis and omnipresence in body fluids have made them important players for prognosis, diagnosis and management of T2DM. Owing to the limitations of classical biomarkers of diabetes such as fasting plasma glucose, glycosylated haemoglobin (HbA1c) lack in predicting the risk of development of diabetes complications in a susceptible population. The miRNAs can act as ideal biomarkers for diabetes associated complications. Identification of specific miRNA signatures to detect diabetes and ideally to find out the risk of development of diabetes-associated complications in susceptible population is the essential requirement of the present clinical strategies for controlling diabetes worldwide. In this article, we summarize the potential miRNAs and miRNA signatures involved in the β cell activities and diabetes associated macrovascular and microvascular complications. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  2. Characterization of a novel cystatin type 2 from Rhipicephalus microplus midgut.

    Science.gov (United States)

    Cardoso, Thyago H S; Lu, Stephen; Gonzalez, Boris R G; Torquato, Ricardo J S; Tanaka, Aparecida S

    2017-09-01

    The Rhipicephalus (Boophilus) microplus is an exclusive bovine ectoparasite responsible for the transmission of pathogens that decrease meat, leather and milk productions. Cattle vaccination is an alternative to control tick infestations, but the discovery of potential antigens is still a challenge for researchers. Recently, our group performed a midgut transcriptome of engorged R. microplus tick, and out of 800 ESTs sequences one cystatin-coding sequence was identified and named Rmcystatin-4. In order to understand the physiological role of Rmcystatin-4, the aim of this work was the expression, purification and functional characterization of a novel type 2 cystatin from the tick R. microplus. Rmcystatin-4 gene expression was identified mostly in tick midgut suggesting its possible role in blood digestion control. Our data showed that rRmcystatin-4 was successfully expressed in active form using Pichia pastoris system and the purified inhibitor presented high selectivity to BmCl-1 (Ki = 0.046 nM). Moreover, rRmcystatin-4 was able to impaired BmCl-1 activity towards bovine hemoglobin. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  3. The effect of immunosuppressive molecules on T-cell metabolic reprogramming.

    Science.gov (United States)

    Fernández-Ramos, Ana A; Poindessous, Virginie; Marchetti-Laurent, Catherine; Pallet, Nicolas; Loriot, Marie-Anne

    2016-08-01

    T lymphocytes undergo metabolic reprogramming to adapt to extracellular and intracellular cues. Specifically, T-cell metabolism results into ATP production, anabolism and catabolism pathways that not only support rapid cell growth and proliferation, but also differentiation and effector functions, recently referred as "immunometabolism". Quiescent naïve T cells rely on oxidative phosphorylation whereas aerobic glycolysis (Warburg effect) occurs in activated T cells (effector CD4(+) and CD8(+)). The molecular mechanisms that sense metabolic status and influence T-cell function require metabolic checkpoints including sensors of metabolic signals and transducers (Myc, HIF-1α, AMPK and mTOR). These metabolic checkpoints represent a novel therapeutic strategy for immune modulation. Interestingly, many immunosuppressive drugs including mTOR inhibitors (rapamycin), calcineurin inhibitors (tacrolimus, cyclosporine A) and inhibitors of de novo purine synthesis (6-mercaptopurine, mycophenolic acid and methotrexate) provide examples into how modulating these metabolic checkpoints can regulate T-cell activation, differentiation and function. In this Review we highlight emerging concepts about metabolic reprogramming in T-cell responses and we discuss the potential therapeutic interventions to influence T-cell fate and effector function. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  4. Ganglioside and related-sphingolipid profiles are altered in a cellular model of Alzheimer's disease.

    Science.gov (United States)

    Noel, Anastasia; Ingrand, Sabrina; Barrier, Laurence

    2017-06-01

    Sphingolipid-related issues are increasingly discussed to contribute to the neuropathological process of Alzheimer's disease (AD). In this study, gangliosides and related-sphingolipids (ceramides, neutral glycosphingolipids and sphingomyelins) were analyzed in neuroglioma (H4) cells expressing the Swedish mutation of the human amyloid precursor protein (H4APPsw) and compared with those of wild-type control H4 cells. These cells were chosen since H4APPsw cells were previously reported to reproduce well some essential features of AD. We found that H4APPsw cells exhibited a striking elevation of the simplest ganglioside GM3, an abnormality that was consistently reported in AD patients and animal models of AD. Concomitantly, the levels of both lactosylceramide (the immediate metabolic precursor of GM3) and ganglioside GD1a increased, suggesting a deregulation in the biosynthesis of gangliosides in the H4APPsw cells. Moreover, while the total ceramide level remained unaltered in H4APPsw cells, a shift in ceramide composition from long chain - to very long chain fatty acid-ceramide species was recorded. Because sphingolipid alterations occurring in H4APPsw cells were similar to those observed in transgenic mice and in human brains, this cellular model might be useful to further explore the complex role of sphingolipids in AD pathogenesis. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  5. Quercetin-6-C-β-D-glucopyranoside, natural analog of quercetin exhibits anti-prostate cancer activity by inhibiting Akt-mTOR pathway via aryl hydrocarbon receptor.

    Science.gov (United States)

    Hamidullah; Kumar, Rajeev; Saini, Karan Singh; Kumar, Amit; Kumar, Sudhir; Ramakrishna, E; Maurya, Rakesh; Konwar, Rituraj; Chattopadhyay, Naibedya

    2015-12-01

    Pre-clinical studies suggest mitigating effect of dietary flavonoid quercetin against cancer and other diseases. However, quercetin suffers from poor metabolic stability, which appears to offset its pharmacological efficacy. Recently, we isolated quercetin-6-C-β-D-glucopyranoside (QCG) from Ulmus wallichiana planchon that has greater stability profile over quercetin. In the present study, the cytotoxic and apoptotic effects of QCG on prostate cancer cells were assessed. QCG inhibited prostate cancer cell proliferation by arresting cells at G0/G1 phase of cell cycle and induces apoptosis as evident from cytochrome c release, cleavage of caspase 3 and poly (ADP-ribose) polymerase. Mechanistic studies revealed that QCG inhibited reactive oxygen species (ROS) generation and Akt/mTOR cell survival pathways. Aryl hydrocarbon receptor (AhR) was a critical mediator of QCG action as knockdown of AhR attenuated QCG-induced cell cycle arrest, apoptosis and inhibition of Akt/mTOR pathway in prostate cancer cells. Taken together, our results suggest that QCG exhibits anti-cancer activity against prostate cancer cells via AhR-mediated down regulation of Akt/mTOR pathway in PC-3 cells. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. European multicentre evaluation of the Du Pont Dimension 380 under the auspices of the European Group for the Evaluation of Analytical Systems in Laboratory Medicine (EGE-Lab).

    Science.gov (United States)

    Hänseler, E; Vonderschmitt, D; Haeckel, R; Römer, M; Collombel, C; Goudable, J; Pourcher, E

    1991-01-01

    The Clinical Chemistry Analyzer Dimension 380 manufactured by Du Pont de Nemours was tested in a multicentre evaluation according to the guide-lines of the European Committee for Clinical Laboratory Standards (ECCLS) and in part to the protocol of the Société Française de Biologie Clinique (SFBC). The instrument and the reagents were evaluated as a system, since both reagents and reagent cartridges are specifically designed for the instrument. Fourteen analytes including electrolytes, substrates and enzymes were tested. The evaluators summarized their experience as follows: 1. All parameters tested yield results comparable to established procedures. 2. Very good performance of the ion-selective-electrode unit. 3. The imprecision data of the system are, for most parameters, between 1 and 4% CV and thus equal to or better than those of the instruments compared. 4. No reagent or sample carry-over was detected after a minor modification of the instrument. 5. The linearity of Dimension test methods in general covers the range stated by the manufacturer. 6. Very good stability of the calibration curves (up to 2 months). 7. Good practicability of the whole system, including handling of reagents and a very user-friendly software.

  7. 甜叶菊萃取工业的废水处理工程调试思路探讨%Discussion on Operation and Debtlgging of Stevia Extracting Industrial Wastewater Treatment

    Institute of Scientific and Technical Information of China (English)

    张瑜琦; 张红莉; 李正; 曹文平; 刘春阳

    2011-01-01

    甜叶菊萃取工业的废水是一种高浓度、难降解废水,是目前污染较重的工业废水之一。以江西某生物技术公司所产生的甜叶菊萃取工业的废水处理工程中的问题为例,深入剖析了其症结所在,并针对其实际情况提出了一定的整改措施和方案,最后从原理上对这些整改方案进行了解析,以期为该工业废水的处理提供参考。%The stevia extracting industrial wastewater is a kind of high concentration and non -biodegradable sewage which would cause serious pollution. This paper analyzes the problems of stevia extracting industrial wastewater treatment in one Jiangxi biologieal technology company and proposes certain measures and processes to improve the treatment efficiencies according to the actual operation. Finally, this paper discusses the above mentioned measures based on relative theories with a view to provide reference for the wastewater treatment of this industry.

  8. Biographer: web-based editing and rendering of SBGN compliant biochemical networks.

    Science.gov (United States)

    Krause, Falko; Schulz, Marvin; Ripkens, Ben; Flöttmann, Max; Krantz, Marcus; Klipp, Edda; Handorf, Thomas

    2013-06-01

    The rapid accumulation of knowledge in the field of Systems Biology during the past years requires advanced, but simple-to-use, methods for the visualization of information in a structured and easily comprehensible manner. We have developed biographer, a web-based renderer and editor for reaction networks, which can be integrated as a library into tools dealing with network-related information. Our software enables visualizations based on the emerging standard Systems Biology Graphical Notation. It is able to import networks encoded in various formats such as SBML, SBGN-ML and jSBGN, a custom lightweight exchange format. The core package is implemented in HTML5, CSS and JavaScript and can be used within any kind of web-based project. It features interactive graph-editing tools and automatic graph layout algorithms. In addition, we provide a standalone graph editor and a web server, which contains enhanced features like web services for the import and export of models and visualizations in different formats. The biographer tool can be used at and downloaded from the web page http://biographer.biologie.hu-berlin.de/. The different software packages, including a server-independent version as well as a web server for Windows and Linux based systems, are available at http://code.google.com/p/biographer/ under the open-source license LGPL

  9. The role of dietary acid load and mild metabolic acidosis in insulin resistance in humans.

    Science.gov (United States)

    Williams, Rebecca S; Kozan, Pinar; Samocha-Bonet, Dorit

    2016-05-01

    Type 2 diabetes is increasingly being recognised as a global health crisis (World Health Organisation). Insulin resistance is closely associated with obesity and precedes the development of type 2 diabetes. However, there is now increasing evidence to suggest that diet itself may independently be associated with type 2 diabetes risk. A diet with a high acid load (or high potential renal net acid load, PRAL) can result in a decrease in pH towards the lower end of the normal physiological range, which may in turn lead to the development of insulin resistance. Conversely, reducing dietary acid load (the so called 'alkaline diet') may be protective and prevent the onset of type 2 diabetes. Here, we explore the influence of dietary acid load on the development of mild metabolic acidosis and induction of insulin resistance. Whilst large prospective cohort studies link high dietary acid load or low serum bicarbonate with the development of type 2 diabetes, the effect of a diet with a low acid (or high alkaline) load remains unclear. Further interventional studies are required to investigate the influence of dietary composition on the body's acid/base balance, insulin resistance and incidence of type 2 diabetes. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Fidélisation du couple hôte-vecteur facteur probable de spéciation : 14 espèces de Plasmodium de la Pie

    Directory of Open Access Journals (Sweden)

    Chavatte J.M.

    2007-03-01

    Full Text Available Les Plasmodium de 33 Pies établies dans deux parcs proches de Paris ont été étudiés. La plupart des Oiseaux étaient polyparasités; 14 espèces dont 10 nouvelles ont été observées et décrites. L’abondance surprenante d’espèces différentes est attribuée à un phénomène qui est désigné sous le terme de “fidélisation du couple hôte-vecteur”. En effet, les particularités biologiques de l’hôte (territoires contigus, mais bien définis et des vecteurs présumés (nombreuses espèces d’Aedes à biologie distincte entraînent un morcellement des niches. Ce type d’isolement s’ajoute aux autres facteurs classiques en parasitologie (géographie, microlocalisations, horaires et aboutit à des isolements multiples, donc à de nombreuses spéciations.

  11. Candida albicans susceptibility to lactoperoxidase-generated hypoiodite

    Directory of Open Access Journals (Sweden)

    Mohamed Ahariz

    2010-08-01

    Full Text Available Mohamed Ahariz1, Philippe Courtois21Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, Belgium; 2Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, Belgium and UER de Biologie Médicale, Haute Ecole Francisco Ferrer, Brussels, BelgiumAbstract: In vivo, lactoperoxidase produces hypothiocyanite (OSCN- from thiocyanate (SCN- in the presence of hydrogen peroxide (H2O2; in vitro, iodide (I- can be oxidized into hypoiodite (OI- by this enzyme. The aim of this study was to compare in vitro the anti-Candida effect of iodide versus thiocyanate used as lactoperoxidase substrate to prevent Candida biofilms development. Candida albicans ATCC 10231 susceptibility upon both peroxidase systems was tested in three different experimental designs: (i in a liquid culture medium, (ii in an interface model between solid culture medium and gel containing the enzymic systems, (iii in a biofilm model onto titanium and acrylic resin. Yeast growth in liquid medium was monitored by turbidimetry at 600 nm. Material-adherent yeast biomass was evaluated by the tetrazolium salt MTT method. The iodide-peroxidase system has been shown to inhibit Candida biofilm formation at lower substrate concentrations (~200 fold less H2O2 donor and for longer incubation periods than the thiocyanate-peroxidase system. In conclusion, efficiency of lactoperoxidase-generated OI- to prevent C. albicans biofilm development allows refining iodine antifungal use in ex vivo conditions.Keywords: denture, iodide, oral, peroxidase, saliva, titanium

  12. NUTRITION Acides gras polyinsaturés de microalgues : intérêts et développements actuels

    Directory of Open Access Journals (Sweden)

    Poisson Laurent

    2002-03-01

    Full Text Available Commercialisés comme compléments nutritionnels sous forme de capsules ou utilisés comme ingrédients pour la préparation de lait maternisé, les acides gras polyinsaturés (AGPI de la série ôméga3 sont principalement obtenus à partir d’huiles de poisson. Du fait de leur richesse en AGPI, les microalgues constituent une source alternative à fort potentiel pour l’obtention de ces acides gras d’intérêt. Différents travaux, cherchant à améliorer la productivité des photobioréacteurs et les procédés de purification, ont largement contribué à réduire les coûts de production d’AGPI d’origine microalgale. Toutefois, pour rendre les microalgues compétitives par rapport aux huiles de poisson pour l’obtention d’AGPI, des travaux d’exploration métabolique, de biologie moléculaire et de génie enzymatique sont encore à mener.

  13. Effects of jetties on semiterrestrial areas - field testing and numerical modelling; Auswirkungen von Buhnen auf semiterrestrische Flaechen - Feldbeprobung und numerische Modellierung

    Energy Technology Data Exchange (ETDEWEB)

    Krebs, M. [TU Darmstadt (Germany). Inst. fuer Wasserbau und Wasserwirtschaft

    2000-07-01

    Five jetty fields of the middle section of the Elbe river between km 418 and 427 were selected according to different hydrodynamic and morphodynamic characteristics, and their abiotic and biotic characteristics were analyzed in an extensive measuring programme. Abiotic field data (sediment analyses, ADCP velocity profiles, ADV measurements) were used for adapting numerical models to solve hydrodynamic and morphodynamic problems, for validating measurements, and for calculating scenarios. Particular interest was taken in the changes brought about by the high water period of November 1998. [German] An der mittleren Elbe bei km 418 und 427 wurden fuenf Buhnenfelder nach unterschiedlichen hydro- und morphodynamischen Merkmalen ausgewaehlt und nach einem umfangreichen Messprogramm bezueglich Abiotik und Biotik untersucht (siehe auch Beitrag des Teilprojektes Biologie). Aufgenommene abiotische Felddaten wie Sedimentanalysen, ADCP-Geschwindigkeitsprofile und ADV-Messungen werden verwendet, um numerische Modelle fuer hydro- und morphodynamische Fragestellungen anzupassen und die Messergebnisse zu ueberpruefen bzw. Szenarien zu berechnen. Dabei sind besonders diejenigen Veraenderungen Gegenstand der Untersuchung, die das Hochwasser im November 1998 verursachten. (orig.)

  14. Changing in lipid profile induced by the mutation of Foxn1 gene: A lipidomic analysis of Nude mice skin.

    Science.gov (United States)

    Lanzini, Justine; Dargère, Delphine; Regazzetti, Anne; Tebani, Abdellah; Laprévote, Olivier; Auzeil, Nicolas

    2015-11-01

    Nude mice carry a spontaneous mutation affecting the gene Foxn1 mainly expressed in the epidermis. This gene is involved in several skin functions, especially in the proliferation and the differentiation of keratinocytes which are key cells of epithelial barrier. The skin, a protective barrier for the body, is essentially composed of lipids. Taking into account these factors, we conducted a lipidomic study to search for any changes in lipid composition of skin possibly related to Foxn1 mutation. Lipids were extracted from skin biopsies of Nude and BALB/c mice to be analyzed by liquid chromatography coupled to a high resolution mass spectrometer (HRMS). Multivariate and univariate data analyses were carried out to compare lipid extracts. Identification was performed using HRMS data, retention time and mass spectrometry fragmentation study. These results indicate that mutation of Foxn1 leads to significant modifications in the lipidome in Nude mice skin. An increase in cholesterol sulfate, phospholipids, sphingolipids and fatty acids associated with a decrease in glycerolipids suggest that the lipidome in mice skin is regulated by the Foxn1 gene. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  15. Insights into ligand binding to a glutathione S-transferase from mango: Structure, thermodynamics and kinetics.

    Science.gov (United States)

    Valenzuela-Chavira, Ignacio; Contreras-Vergara, Carmen A; Arvizu-Flores, Aldo A; Serrano-Posada, Hugo; Lopez-Zavala, Alonso A; García-Orozco, Karina D; Hernandez-Paredes, Javier; Rudiño-Piñera, Enrique; Stojanoff, Vivian; Sotelo-Mundo, Rogerio R; Islas-Osuna, Maria A

    2017-04-01

    We studied a mango glutathione S-transferase (GST) (Mangifera indica) bound to glutathione (GSH) and S-hexyl glutathione (GSX). This GST Tau class (MiGSTU) had a molecular mass of 25.5 kDa. MiGSTU Michaelis-Menten kinetic constants were determined for their substrates obtaining a Km, Vmax and kcat for CDNB of 0.792 mM, 80.58 mM min(-1) and 68.49 s(-1) respectively and 0.693 mM, 105.32 mM min(-1) and 89.57 s(-1), for reduced GSH respectively. MiGSTU had a micromolar affinity towards GSH (5.2 μM) or GSX (7.8 μM). The crystal structure of the MiGSTU in apo or bound to GSH or GSX generated a model that explains the thermodynamic signatures of binding and showed the importance of enthalpic-entropic compensation in ligand binding to Tau-class GST enzymes. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. GRĂDINILE UNIVERSITARE: ISTORIA APARIŢIEI ŞI ROLUL LOR

    Directory of Open Access Journals (Sweden)

    Natalia CIUBUC

    2016-02-01

    Full Text Available Istoria grădinilor universitare ne oferă posibilitatea nu doar să cunoaştem evoluţia acestora, dar şi particularităţile de amenajare a lor, sugerând şi soluţii interesante pentru grădinile din Republica Moldova, inclusiv pentru parcul USM. Fondarea parcului universitar în curtea USM a permis nu doar crearea unei ambianţe plăcute în incinta USM, dar vine să ofere o bază de studiu pentru studenţii dela Facultateade Biologie şi Pedologie. University Gardens: The History and the ImportanceThe history of the university gardens gives us not only the knowledge about their evolution, but also a appropriate description of their features and offer interesting solutions for the gardens fromMoldova, including USM garden. The USM court park foundation creates, not only a pleasant atmosphere inside USM, but also provides a basis for study for the students from the Faculty of Biology and Soil Science. 

  17. Chemical analysis of radioactive liquid wastes. Volumetric dosage of sulfates in the presence of phosphates, 'nitrochromazo' being used as an indicator; Analyse chimique des effluents radioactifs - dosage volumetrique des sulfates en presence de phosphates a l'aide du 'nitrochromazo' comme indicateur

    Energy Technology Data Exchange (ETDEWEB)

    Testemale, G.; Girault, J. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    A simple titration technique of SO{sub 4} ions in the presence of PO{sub 4} ions has been perfected. The pH of the medium is stated to 1,7-2,0 the colour of the indicator changes from violet to blue. The method is quick, accurate and can be fitted to biological studies or in the industry of fertilizes. The synthesis method of nitrochromazo (acid 2, 7 bis (4 nitro 2 sulfobenzene 1 azo) 1-8 hydroxynaphthalene 3-6 disulfonic) is described. (authors) [French] Une technique simple de titrage des ions SO{sub 4} en presence d'ions PO{sub 4} a ete mise au point. Le pH du milieu est fixe a 1,7-2,0, le virage de l'indicateur s'effectue du violet au bleu. La methode est rapide, precise et peut etre adaptee a des travaux de biologie ou dans l'industrie des engrais. La methode de synthese du 'Nitrochromazo' (acide 2, 7 bis (4 nitro 2 sulfobenzene 1 azo) 1-8 dihydroxynapthtalene 3-6 disulfonique) est decrite. (auteurs)

  18. Contributions on biomedical imaging, with a side-look at molecular imaging; Beitraege zur biomedizinischen Bildgebung mit einem Seitenblick auf Molecular Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, G. (ed.)

    2004-05-01

    This report is intended as a brief introduction to the emerging scientific field of biomedical imaging. The breadth of the subject is shown and future fields of research are indicated, which hopefully will serve as a guide to the identification of starting points for the research in 'Biomedical and/or Molecular Imaging' at the GSF-National Research Center for Environment and Health. The report starts with a brief sketch of the history. Then a - necessarily incomplete - list of research topics is presented. It is organized in two parts: the first one addresses medical imaging, and the second one is concerned with biological point aspects of the matter. (orig.) [German] In diesem Bericht sind einige Beitraege zum Gebiet 'Bildgebende Verfahren in Biologie und Medizin' zusammengestellt. Sie stammen saemtlich aus dem Institut fuer Biomathematik und Biometrie, IBB, am Forschungszentrum fuer Umwelt und Gesundheit, GSF, in Muenchen/Neuherberg, und seinem engeren Umfeld. Ziel war es, zu sichten, was in und um diesen Themenkreis herum an Wissen und sonstiger Kompetenz hier vorhanden ist. Einige am IBB etablierte Gebiete wie Roentgen-Mammographie oder funktionelle Magnetresonanztherapie wurden ausgeblendet. Der Grund ist die Fokussierung auf ein nicht exakt definierbares, neues Gebiet der Bildgebung, das unter dem Namen 'Molecular Imaging' kursiert und derzeit Furore macht macht. (orig.)

  19. Classification of gastro-entero-pancreatic neuroendocrine tumors; Klassifikation gastroenteropankreatischer neuroendokriner Tumoren

    Energy Technology Data Exchange (ETDEWEB)

    Perren, A. [Klinikum Rechts der Isar, Technische UniversitaetMuenchen, Institut fuer Pathologie und pathologische Anatomie, Muenchen (Germany); Schmitt, A. [Universitaetsspital Zuerich, Institut fuer Klinische Pathologie, Departement Pathologie, Zuerich (Switzerland); Komminoth, P. [Stadtspital Triemli, Zuerich (Switzerland). Institut fuer Pathologie; Pavel, M. [Charite, Universitaetsmedizin Berlin (Germany). Medizinische Klinik mit Schwerpunkt Hepatologie and Gastroenterologie

    2009-03-15

    Tumors of the disseminated/diffuse neuroendocrine system (NET) are characterized by a common phenotype. However, the biology varies according to histomorphology, endocrine symptoms and organ of origin. The WHO classification takes these differences into account and uses a common framework, where the parameters size and extent of invasion vary according to the organ of origin. In order to achieve a further standardization of reporting the European Neuroendocrine Tumor Society (ENETS) recently proposed a tumor-node-metastasis (TNM) staging and grading system for gastro-entero-pancreatic NET. (orig.) [German] Tumoren des disseminierten/diffusen neuroendokrinen Systems sind durch einen gemeinsamen Phaenotyp gekennzeichnet. In ihrer Biologie unterscheiden sich neuroendokrine Tumoren (NET) jedoch bzgl. Morphologie, endokrinologischer Symptomatik und Ursprungsorgan. Die WHO-Klassifikation traegt diesen Unterschieden Rechnung und klassifiziert NET nach einem einheitlichen Vorgehen, wobei die Parameter Groesse und Invasionstiefe je nach Ursprungsorgan variieren. Um die Nomenklatur weiter zu vereinheitlichen, wurde vor kurzem von der ''European Neuroendocrine Tumor Society'' (ENETS) der Vorschlag einer TNM-Stadien-Einteilung und Graduierung gastroenteropankreatischer NET vorgelegt. (orig.)

  20. Characterization and antibiotic susceptibility of Listeria monocytogenes isolated from poultry and red meat in Morocco

    Directory of Open Access Journals (Sweden)

    Hayat Ennaji

    2008-09-01

    Full Text Available Hayat Ennaji1,2, Mohammed Timinouni2, My Mustapha Ennaji3, Mohammed Hassar1, Nozha Cohen11Laboratoire de Microbiologie et Hygiène des Aliments et de l’Environnement, Institut Pasteur du Maroc., Casablanca, Morocco; 2Laboratoire de Microbiologie et Biologie Moléculaire, Institut Pasteur du Maroc., Casablanca, Morocco; 3Laboratoire de Virologie et Hygiène and Microbiologie., Faculté des Sciences et Techniques - Mohammedia, Université Hassan II, Mohammedia, MoroccoAbstract: This study was carried out on 426 samples of raw meats collected from butcheries and supermarkets in Casablanca, Morocco. The samples were examined for the occurrence of Listeria species. Strains of Listeria monocytogenes were characterized by several biochemical tests and confirmed by polymerase chain reaction (PCR. β-hemolytic cultures and nonhemolytic isolates were tested for biochemical properties with the Listeria API test. Among the 43 Listeria species isolates; we identified 10 strains for L. monocytogenes (23.3%, 31 strains for L. innocua (72.1% and 2 strains for L. welshimeri (4.6%. Strains of L. monocytogenes were separated by multiplex PCR; two serogroups IIb and IVb were thus differentiated. Antibiotic susceptibility of L. monocytogenes to 21 antibiotics was determined by the disk diffusion method. All isolates were susceptible to a wide range of the tested antibiotics with the exception of nalidixic acid, colistine and cephalosporins second and third generation for which they were all resistant.Keywords: antibiotic susceptibility, Listeria monocytogenes, meat, PCR

  1. [Memory and epilepsy].

    Science.gov (United States)

    Dupont, Sophie

    2010-01-01

    Medial temporal lobe epilepsy is a chronic neurological disease that begins in the early age and that is associated with frequent and disturbing memory deficits. Repeated seizures will lead to the formation of an epileptogenic network that may interfere with physiological neuronal networks and thus with normal brain function: by direct activation or indirectly by deactivation during a seizure, see for example the dreamy state or the ''déja vécu'' phenomenon during temporal seizures; by ictal or post-ictal inhibition, see for example ictal or post-ictal amnesia; by a repetitive and chronic modulation leading to a reorganization of the physiological neuronal networks. The study of these interactions between epileptic and physiological neural networks must lead to better explore the patient's memory and predict memory worsening before temporal lobe surgery and to better understand the reorganization of memory networks in chronic epilepsy. The goal is double: (1) improve the prediction of post-operative memory worsening and guide rehabilitation in epileptic clinical practice; (2) improve the pathophysiological knowledge about memory processes. © Société de Biologie, 2010.

  2. Identifikationsverfahren zur Analyse von EEG-Signalen bei Epilepsie mit Reaktions-Diffusions Netzwerken

    Science.gov (United States)

    Gollas, F.; Tetzlaff, R.

    2007-06-01

    Partielle Differentialgleichungen des Reaktions-Diffusions-Typs beschreiben Phänomene wie Musterbildung, nichtlineare Wellenausbreitung und deterministisches Chaos und werden oft zur Untersuchung komplexer Vorgänge auf den Gebieten der Biologie, Chemie und Physik herangezogen. Zellulare Nichtlineare Netzwerke (CNN) sind eine räumliche Anordnung vergleichsweise einfacher dynamischer Systeme, die eine lokale Kopplung untereinander aufweisen. Durch eine Diskretisierung der Ortsvariablen können Reaktions-Diffusions-Gleichungen häufig auf CNN mit nichtlinearen Gewichtsfunktionen abgebildet werden. Die resultierenden Reaktions-Diffusions-CNN (RD-CNN) weisen dann in ihrer Dynamik näherungsweise gleiches Verhalten wie die zugrunde gelegten Reaktions-Diffusions-Systeme auf. Werden RD-CNN zur Identifikation neuronaler Strukturen anhand von EEG-Signalen herangezogen, so besteht die Möglichkeit festzustellen, ob das gefundene Netzwerk lokale Aktivität aufweist. Die von Chua eingeführte Theorie der lokalen Aktivität Chua (1998); Dogaru und Chua (1998) liefert eine notwendige Bedingung für das Auftreten von emergentem Verhalten in zellularen Netzwerken. Änderungen in den Parametern bestimmter RD-CNN könnten auf bevorstehende epileptische Anfälle hinweisen. In diesem Beitrag steht die Identifikation neuronaler Strukturen anhand von EEG-Signalen durch Reaktions-Diffusions-Netzwerke im Vordergrund der dargestellten Untersuchungen. In der Ergebnisdiskussion wird insbesondere auch die Frage nach einer geeigneten Netzwerkstruktur mit minimaler Komplexität behandelt.

  3. Identifikationsverfahren zur Analyse von EEG-Signalen bei Epilepsie mit Reaktions-Diffusions Netzwerken

    Directory of Open Access Journals (Sweden)

    F. Gollas

    2007-06-01

    Full Text Available Partielle Differentialgleichungen des Reaktions-Diffusions-Typs beschreiben Phänomene wie Musterbildung, nichtlineare Wellenausbreitung und deterministisches Chaos und werden oft zur Untersuchung komplexer Vorgänge auf den Gebieten der Biologie, Chemie und Physik herangezogen. Zellulare Nichtlineare Netzwerke (CNN sind eine räumliche Anordnung vergleichsweise einfacher dynamischer Systeme, die eine lokale Kopplung untereinander aufweisen. Durch eine Diskretisierung der Ortsvariablen können Reaktions-Diffusions-Gleichungen häufig auf CNN mit nichtlinearen Gewichtsfunktionen abgebildet werden. Die resultierenden Reaktions-Diffusions-CNN (RD-CNN weisen dann in ihrer Dynamik näherungsweise gleiches Verhalten wie die zugrunde gelegten Reaktions-Diffusions-Systeme auf. Werden RD-CNN zur Identifikation neuronaler Strukturen anhand von EEG-Signalen herangezogen, so besteht die Möglichkeit festzustellen, ob das gefundene Netzwerk lokale Aktivität aufweist. Die von Chua eingeführte Theorie der lokalen Aktivität Chua (1998; Dogaru und Chua (1998 liefert eine notwendige Bedingung für das Auftreten von emergentem Verhalten in zellularen Netzwerken. Änderungen in den Parametern bestimmter RD-CNN könnten auf bevorstehende epileptische Anfälle hinweisen. In diesem Beitrag steht die Identifikation neuronaler Strukturen anhand von EEG-Signalen durch Reaktions-Diffusions-Netzwerke im Vordergrund der dargestellten Untersuchungen. In der Ergebnisdiskussion wird insbesondere auch die Frage nach einer geeigneten Netzwerkstruktur mit minimaler Komplexität behandelt.

  4. [Method selected for the determination of creatinine in plasma or serum. Choice of optimal conditions of measurement].

    Science.gov (United States)

    Labbé, D; Vassault, A; Cherruau, B; Baltassat, P; Bonète, R; Carroger, G; Costantini, A; Guérin, S; Houot, O; Lacour, B; Nicolas, A; Thioulouse, E; Trépo, D

    1996-01-01

    The method selected by the SFBC (Société française de biologie clinique) is derived from the colorimetric reaction of creatinine with alkaline picrate, measured kinetically, without any pretreatment step. The key parameters of the reaction determining the quality of the results are studied, with special regard to samples including known interferents. The aims of the study were to gain an optimal analytical sensitivity and to reduce main interferences (acetoacetate, bilirubine, glucose, protein) which plague the Jaffé reaction, through a comprehensive study of the reagents, of their concentrations and of the analytical procedures. The selected concentrations (in the test) are: 150 mmol/L sodium hydroxide, 10 mmol/L picric acid and 2 g/L sodium dodecyl sulfate. Ten millilitres of a BRIJ solution (30% volvol) are added to the reagent. The operating procedures are as follow: sample ratio 0.07 to 0.08; wavelength 505 to 510 nm; temperature 37 degrees C; incubation of the specimen with the alkaline reagent 5 mn (at least), before starting the reaction with picric acid. A seric calibrator is recommended. The first measurement is taken 20 to 40 s after starting the reaction. Total measurement time is 120 to 150 seconds.

  5. Life at extreme conditions: Neutron scattering studies of biological molecules suggest that evolution selected dynamics

    Indian Academy of Sciences (India)

    Joseph (Giuseppe) Zaccai

    2008-10-01

    The short review concentrates on recent work performed at the neutrons in biology laboratories of the Institut Laue Langevin and Institut de Biologie Structurale in Grenoble. Extremophile organisms have been discovered that require extreme conditions of temperature, pressure or solvent environment for survival. The existence of such organisms poses a significant challenge in understanding the physical chemistry of their proteins, in view of the great sensitivity of protein structure and stability to the aqueous environment and to external conditions in general. Results of neutron scattering measurements on the dynamics of proteins from extremophile organisms, in vitro as well as in vivo, indicated remarkably how adaptation to extreme conditions involves forces and fluctuation amplitudes that have been selected specifically, suggesting that evolutionary macromolecular selection proceeded via dynamics. The experiments were performed on a halophilic protein, and membrane adapted to high salt, a thermophilic enzyme adapted to high temperature and its mesophilic (adapted to 37°C) homologue; and in vivo for psychrophilic, mesophilic, thermophilic and hyperthermophilic bacteria, adapted respectively to temperatures of 4°C, 37°C, 75°C and 85°C. Further work demonstrated the existence of a water component of exceptionally low mobility in an extreme halophile from the Dead Sea, which is not present in mesophile bacterial cells.

  6. Role of nuclear Lamin A/C in cardiomyocyte functions.

    Science.gov (United States)

    Carmosino, Monica; Torretta, Silvia; Procino, Giuseppe; Gerbino, Andrea; Forleo, Cinzia; Favale, Stefano; Svelto, Maria

    2014-10-01

    Lamin A/C is a structural protein of the nuclear envelope (NE) and cardiac involvement in Lamin A/C mutations was one of the first phenotypes to be reported in humans, suggesting a crucial role of this protein in the cardiomyocytes function. Mutations in LMNA gene cause a class of pathologies generically named 'Lamanopathies' mainly involving heart and skeletal muscles. Moreover, the well-known disease called Hutchinson-Gilford Progeria Syndrome due to extensive mutations in LMNA gene, in addition to the systemic phenotype of premature aging, is characterised by the death of patients at around 13 typically for a heart attack or stroke, suggesting again the heart as the main site sensitive to Lamin A/C disfunction. Indeed, the identification of the roles of the Lamin A/C in cardiomyocytes function is a key area of exploration. One of the primary biological roles recently conferred to Lamin A/C is to affect contractile cells lineage determination and senescence. Then, in differentiated adult cardiomyocytes both the 'structural' and 'gene expression hypothesis' could explain the role of Lamin A in the function of cardiomyocytes. In fact, recent advances in the field propose that the structural weakness/stiffness of the NE, regulated by Lamin A/C amount in NE, can 'consequently' alter gene expression. © 2014 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  7. Na+-K+-2Cl- cotransporter type 2 trafficking and activity: the role of interacting proteins.

    Science.gov (United States)

    Carmosino, Monica; Procino, Giuseppe; Svelto, Maria

    2012-04-01

    The central role of Na+-K+-2Cl- cotransporter type 2 (NKCC2) in vectorial transepithelial salt reabsorption in thick ascending limb cells from Henle's loop in the kidney is evidenced by the effects of loop diuretics, the pharmacological inhibitors of NKCC2, that are amongst the most powerful antihypertensive drugs available to date. Moreover, genetic mutations of the NKCC2 encoding gene resulting in impaired apical targeting and function of NKCC2 transporter give rise to a pathological phenotype known as type I Bartter syndrome, characterised by a severe volume depletion, hypokalaemia and metabolic alkalosis with high prenatal mortality. On the contrary, excessive NKCC2 activity has been linked with inherited hypertension in humans and in rodent models. Interestingly, in animal models of hypertension, NKCC2 upregulation is achieved by post-translational mechanisms underlining the need to analyse the molecular mechanisms involved in the regulation of NKCC2 trafficking and activity to gain insights in the pathogenesis of hypertension. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

  8. Identification of moesin as NKCC2-interacting protein and analysis of its functional role in the NKCC2 apical trafficking.

    Science.gov (United States)

    Carmosino, Monica; Rizzo, Federica; Procino, Giuseppe; Zolla, Lello; Timperio, Anna Maria; Basco, Davide; Barbieri, Claudia; Torretta, Silvia; Svelto, Maria

    2012-11-01

    The renal Na(+) -K(+) -2Cl(-) co-transporter (NKCC2) is expressed in kidney thick ascending limb cells, where it mediates NaCl re-absorption regulating body salt levels and blood pressure. In this study, we used a well-characterised NKCC2 construct (c-NKCC2) to identify NKCC2-interacting proteins by an antibody shift assay coupled with blue native/SDS-PAGE and mass spectrometry. Among the interacting proteins, we identified moesin, a protein belonging to ezrin, eadixin and moesin family. Co-immunoprecipitation experiments confirmed that c-NKCC2 interacts with the N-terminal domain of moesin in LLC-PK1 cells. Moreover, c-NKCC2 accumulates in intracellular and sub-apical vesicles in cells transfected with a moesin dominant negative green fluorescent protien (GFP)-tagged construct. In addition, moesin knock-down by short interfering RNA decreases by about 50% c-NKCC2 surface expression. Specifically, endocytosis and exocytosis assays showed that moesin knock-down does not affect c-NKCC2 internalisation but strongly reduces exocytosis of the co-transporter. Our data clearly demonstrate that moesin plays a critical role in apical membrane insertion of NKCC2, suggesting a possible involvement of moesin in regulation of Na(+) and Cl(-) absorption in the kidney. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

  9. Modèles et méthodes stochastiques une introduction avec applications

    CERN Document Server

    Del Moral, Pierre

    2014-01-01

    La théorie des probabilités et des processus stochastiques est sans aucun doute l'un des plus importants outils mathématiques des sciences modernes. Le théorie des probabilité s'illustre dans de nombreux domaines issus de la biologie, de la physique, et des sciences de l'ingénieur : dynamique des populations, traitement du signal et de l'image, chimie moléculaire, économétrie, sciences actuarielles, mathématiques financières, ainsi qu'en analyse de risque. Le but de cet ouvrage est de parcourir les principaux modèles et méthodes stochastiques de cette théorie en pleine expansion. Ce voyage ne nécessite aucun bagage spécifique sur la théorie des processus stochastiques. Les outils d'analyses nécessaires à une bonne compréhension sont donnés au fur et à mesure de leur construction, révélant ainsi leur nécessité. La théorie des processus stochastiques est une extension naturelle de la théorie de systèmes dynamiques à des phénomènes aléatoires. Elle contient des formalisation d'é...

  10. Modèles aléatoires en écologie et évolution

    CERN Document Server

    Méléard, Sylvie

    2016-01-01

    Le but du livre est de définir et développer une grande gamme d'outils probabilistes pour la modélisation en biologie des populations, afin de décrire des dynamiques temporelles de quantités biologiques telles que la taille d'une ou plusieurs populations, la proportion d'un allèle dans une population ou la position d'un individu. En partant de modèles markoviens discrets (marches aléatoires, processus de Galton-Watson), nous abordons progressivement le calcul stochastique et les équations différentielles stochastiques, puis les processus markoviens de saut, tels les processus de branchement à temps continu et les processus de naissance et mort. Nous étudions également les processus discret et continu pour l'évolution génétique et les généalogies: processus de Wright-Fisher et coalescent. Le livre détaille systématiquement les calculs de quantités d'intérêt pour les biologistes. De nombreux exercices d'application sont proposés. Le dernier chapitre montre l'apport de ces outils pour des...

  11. Digital Medien im Naturwissenschaftlichen Unterricht

    CERN Document Server

    Meßinger-Koppelt, Jenny

    2014-01-01

    „Morgens, 8 Uhr: Kurz vor der Schultür werden noch die neuesten Posts auf Facebook geliked, ein Selfie in die Whats-App-Gruppe hochgeladen oder auf YouTube noch ein #LOL-Video gestreamed. Dann klingelt es und die Digital Natives greifen wieder zu Stift, Papier und werden frontal mit Fakten gefüttert“ (A. Spang). Für Schüler sind Internet, Smartphone und Tablet-PC heute selbstverständlicher Teil ihrer Lernwelt. Und auch die Alltags- und Berufswelt ist ohne Informationstechnologien nicht mehr vorstellbar. Doch was bedeutet das für den Schulunterricht, insbesondere für die techniknahen Naturwissenschaften? Wie gelingt im Schulalltag die Balance zwischen Kreidezeit und interaktivem Whiteboard nach mittlerweile 30 Jahren Erfahrung mit Schulcomputern? Der vorliegende Sammelband präsentiert zahlreiche Praxisbeispiele aus dem Schulalltag zum sinnvollen Einsatz digitaler Medien im Biologie-, Chemie- und Physik-Unterricht sowie den aktuellen Stand der fachdidaktischen Forschung. Zu Wort kommen Hochschullehr...

  12. Direct determination of uranium in human urine by Icp-SFMS; Determinacion directa de uranio en orina humana por ICP-SFMS

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, H. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Yllera de Ll, A., E-mail: hector.hernandez520@gmail.com [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Medio Ambiente, Av. Complutense 22, 28040 Madrid (Spain)

    2013-10-15

    The success of the measurement and the evaluation of the internal exposure are highly dependent of the effective capacities for the radiation measurement in biological samples (mainly urine and the feces). Usually, during the samples bioassay of human urine, a pre-concentration and purification of the radionuclides is carried out previously to the quantitative analysis. These stages, as the analysis time are the main source of uncertainty in the measurement process. In the uranium case, this is not necessary when are used mass spectrometry techniques, in particular, Mass Spectrometry of Magnetic Sector with Inductively Coupled Plasma (Icp-SFMS). This work presents the results obtained for the uranium analysis in samples of human urine during the participation in the inter-comparison exercises of the Association pour la Promotion de Controle de Qualite des Analyses de Biologie Medicale en Radiotoxicologie (PROCORAD) in the period 2010 and 2011. The analyses were realized directly in the diluted urine samples (dilution factor 1:20) in 5% of HNO{sub 3}. The obtained results, were normalized to the total urine sample (V = 0.5 L), these values coincide with the waited reference values of uranium in the urine sample. Additionally, were calculated the detection limits of {sup 235}U= 0.049 x 10{sup -3} μg L{sup -1} and {sup 238}U= 7.37 x 10{sup -3} μg L{sup -1}. (author)

  13. Resonance Raman enhancement optimization in the visible range by selecting different excitation wavelengths.

    Science.gov (United States)

    Wang, Zhong; Li, Yuee

    2015-09-01

    Resonance enhancement of Raman spectroscopy (RS) has been used to significantly improve the sensitivity and selectivity of detection for specific components in complicated environments. Resonance RS gives more insight into the biochemical structure and reactivity. In this field, selecting a proper excitation wavelength to achieve optimal resonance enhancement is vital for the study of an individual chemical/biological ingredient with a particular absorption characteristic. Raman spectra of three azo derivatives with absorption spectra in the visible range are studied under the same experimental conditions at 488, 532, and 633 nm excitations. Universal laws in the visible range have been concluded by analyzing resonance Raman (RR) spectra of samples. The long wavelength edge of the absorption spectrum is a better choice for intense enhancement and the integrity of a Raman signal. The obtained results are valuable for applying RR for the selective detection of biochemical constituents whose electronic transitions take place at energies corresponding to the visible spectra, which is much friendlier to biologial samples compared to ultraviolet.

  14. Purification process for MUFA- and PUFA-based monoacylglycerols from edible oils.

    Science.gov (United States)

    González-Fernández, M J; Ramos-Bueno, R P; Rodríguez-García, I; Guil-Guerrero, J L

    2017-08-01

    Important health benefits have been attributed to monoacylglycerols (MAGs) due to their various physiological functions, owing to which they become candidates for use as functional foods in order to prevent the onset of certain diseases such as colon cancer. In this work, six edible oils, namely: olive, linseed, sunflower, evening primrose, DHASCO(®) and ARASCO(®) have been processed to obtain different MUFA- and PUFA- based MAGs. First, the oils were hydrolyzed by means of an enzymatic process using porcine pancreatic lipase and then the reaction products were fractionated by using a liquid chromatography column containing silica gel as stationary phase in order to purify the MAGs-enriched fraction. A second chromatography process was performed using silver nitrate coated silica gel as stationary phase, in order to obtain the different MUFA- and PUFA-based MAGs from the corresponding oils. Overall, MAGs based on oleic, linoleic, α-linolenic, γ-linolenic, arachidonic and docosahexaenoic acids have been isolated in high yields and purities (92.6, 97.4, 95.3, 90.9, 100 and 95.3% purity, respectively). Positional distribution was determined by means of (1)H NMR, which revealed a mix of 1(3) and 2-MAGs in variable proportions in the different MAGs. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  15. How cellular membrane properties are affected by the actin cytoskeleton.

    Science.gov (United States)

    Lemière, J; Valentino, F; Campillo, C; Sykes, C

    2016-11-01

    Lipid membranes define the boundaries of living cells and intracellular compartments. The dynamic remodelling of these membranes by the cytoskeleton, a very dynamic structure made of active biopolymers, is crucial in many biological processes such as motility or division. In this review, we present some aspects of cellular membranes and how they are affected by the presence of the actin cytoskeleton. We show that, in parallel with the direct study of membranes and cytoskeleton in vivo, biomimetic in vitro systems allow reconstitution of biological processes in a controlled environment. In particular, we show that liposomes, or giant unilamellar vesicles, encapsulating a reconstituted actin network polymerizing at their membrane are suitable models of living cells and can be used to decipher the relative contributions of membrane and actin on the mechanical properties of the cellular interface. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Didactic Strategy Discussion Based on Artificial Neural Networks Results.

    Science.gov (United States)

    Andina, D.; Bermúdez-Valbuena, R.

    2009-04-01

    Artificial Neural Networks (ANNs) are a mathematical model of the main known characteristics of biological brian dynamics. ANNs inspired in biological reality have been useful to design machines that show some human-like behaviours. Based on them, many experimentes have been succesfully developed emulating several biologial neurons characteristics, as learning how to solve a given problem. Sometimes, experimentes on ANNs feedback to biology and allow advances in understanding the biological brian behaviour, allowing the proposal of new therapies for medical problems involving neurons performing. Following this line, the author present results on artificial learning on ANN, and interpret them aiming to reinforce one of this two didactic estrategies to learn how to solve a given difficult task: a) To train with clear, simple, representative examples and feel confidence in brian generalization capabilities to achieve succes in more complicated cases. b) To teach with a set of difficult cases of the problem feeling confidence that the brian will efficiently solve the rest of cases if it is able to solve the difficult ones. Results may contribute in the discussion of how to orientate the design innovative succesful teaching strategies in the education field.

  17. Victor Henri: 111 years of his equation.

    Science.gov (United States)

    Cornish-Bowden, Athel; Mazat, Jean-Pierre; Nicolas, Serge

    2014-12-01

    Victor Henri's great contribution to the understanding of enzyme kinetics and mechanism is not always given the credit that it deserves. In addition, his earlier work in experimental psychology is totally unknown to biochemists, and his later work in spectroscopy and photobiology almost equally so. Applying great rigour to his analysis he succeeded in obtaining a model of enzyme action that explained all of the observations available to him, and he showed why the considerable amount of work done in the preceding decade had not led to understanding. His view was that only physical chemistry could explain the behaviour of enzymes, and that models should be judged in accordance with their capacity not only to explain previously known facts but also to predict new observations against which they could be tested. The kinetic equation usually attributed to Michaelis and Menten was in reality due to him. His thesis of 1903 is now available in English. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  18. [Guidelines for certification of Activated clotting time (ACT) according to the EN ISO 22870 standards].

    Science.gov (United States)

    Lasne, Dominique; Bauters, Anne; Le Querrec, Agnès; Bourdin, Carole; Voisin, Sophie

    2015-01-01

    Point of care testing (POCT) must comply with regulatory requirements according to standard EN ISO 22870, which identify biologists as responsible for POCT. Activated clotting time (ACT) is mandatory to monitor on whole blood, anticoagulation achieved by unfractionated heparin during cardiopulmonary bypass (CPB) or cardiac catheterization. This test has no equivalent in the laboratory. With the aim to help the multidisciplinary groups for POCT supervision when they have to analyse the wish of medical departments to use ACT and to help the biologists to be in accordance with the standard, we present the guidelines of the GEHT (Groupe d'étude d'hémostase et thrombose) subcommittee "CEC et Biologie délocalisée" for the certification of ACT. These guidelines are based on the SFBC guidelines for the certification of POCT and on the analysis of the literature to ascertain the justification of clinical need and assess the analytical performance of main analyzers used in France, as well as on a survey conducted with French and Belgian biologists.

  19. Time-resolved cell culture assay analyser (TReCCA Analyser) for the analysis of on-line data: data integration--sensor correction--time-resolved IC50 determination.

    Science.gov (United States)

    Lochead, Julia; Schessner, Julia; Werner, Tobias; Wölfl, Stefan

    2015-01-01

    Time-resolved cell culture assays circumvent the need to set arbitrary end-points and reveal the dynamics of quality controlled experiments. However, they lead to the generation of large data sets, which can represent a complexity barrier to their use. We therefore developed the Time-Resolved Cell Culture Assay (TReCCA) Analyser program to perform standard cell assay analyses efficiently and make sophisticated in-depth analyses easily available. The functions of the program include data normalising and averaging, as well as smoothing and slope calculation, pin-pointing exact change time points. A time-resolved IC50/EC50 calculation provides a better understanding of drug toxicity over time and a more accurate drug to drug comparison. Finally the logarithmic sensor recalibration function, for sensors with an exponential calibration curve, homogenises the sensor output and enables the detection of low-scale changes. To illustrate the capabilities of the TReCCA Analyser, we performed on-line monitoring of dissolved oxygen in the culture media of the breast cancer cell line MCF-7 treated with different concentrations of the anti-cancer drug Cisplatin. The TReCCA Analyser is freely available at www.uni-heidelberg.de/fakultaeten/biowissenschaften/ipmb/biologie/woelfl/Research.html. By introducing the program, we hope to encourage more systematic use of time-resolved assays and lead researchers to fully exploit their data.

  20. Inhibitory mechanism of dimercaptopropanesulfonic acid (DMPS) in the cellular biomethylation of arsenic.

    Science.gov (United States)

    Wang, Shuping; Shi, Nan; Geng, Zhirong; Li, Xiangli; Hu, Xin; Wang, Zhilin

    2014-11-01

    Dimercaptopropanesulfonic acid (DMPS) has been approved for the treatment of arsenic poisoning through promoting arsenic excretion and modulating arsenic species. To clarify how DMPS regulates the excretion of arsenic species, we investigated the effects of DMPS on the biomethylation of arsenite (As(3+)) in HepG2 cells. In the experiments, we found that DMPS at low concentrations dramatically decreased the content of arsenic in HepG2 cells and inhibited the cellular methylation of As(3+). Three aspects, the expression of human arsenic (III) methyltransferase (hAS3MT), the accumulation of cellular reactive oxygen species (ROS) and the in vitro enzymatic methylation of arsenic, were considered to explain the reasons for the inhibition of DMPS in arsenic metabolism. The results suggested that DMPS competitively coordinated with As(3+) and monomethylarsonous acid (MMA(3+)) to inhibit the up-regulation of arsenic on the expression of hAS3MT and block arsenic involving in the enzymatic methylation. Moreover, DMPS eliminated arsenic-induced accumulation of ROS, which might contribute to the antidotal effects of DMPS on arsenic posing. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  1. Mesoscale imaging with cryo-light and X-rays: Larger than molecular machines, smaller than a cell.

    Science.gov (United States)

    Ekman, Axel A; Chen, Jian-Hua; Guo, Jessica; McDermott, Gerry; Le Gros, Mark A; Larabell, Carolyn A

    2017-01-01

    In the context of cell biology, the term mesoscale describes length scales ranging from that of an individual cell, down to the size of the molecular machines. In this spatial regime, small building blocks self-organise to form large, functional structures. A comprehensive set of rules governing mesoscale self-organisation has not been established, making the prediction of many cell behaviours difficult, if not impossible. Our knowledge of mesoscale biology comes from experimental data, in particular, imaging. Here, we explore the application of soft X-ray tomography (SXT) to imaging the mesoscale, and describe the structural insights this technology can generate. We also discuss how SXT imaging is complemented by the addition of correlative fluorescence data measured from the same cell. This combination of two discrete imaging modalities produces a 3D view of the cell that blends high-resolution structural information with precise molecular localisation data. © 2016 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  2. Cep126 is required for pericentriolar satellite localisation to the centrosome and for primary cilium formation.

    Science.gov (United States)

    Bonavita, Raffaella; Walas, Dawid; Brown, Anna K; Luini, Alberto; Stephens, David J; Colanzi, Antonino

    2014-08-01

    The centrosome is the primary microtubule-organising centre of animal cells and it has crucial roles in several fundamental cellular functions, including cell division, cell polarity, and intracellular transport. The mechanisms responsible for this are not completely understood. The poorly characterised protein CEP126 localises to the centrosome, pericentriolar satellites and the base of the primary cilium. Suppression of CEP126 expression results in dispersion of the pericentriolar satellites and disruption of the radial organisation of the microtubules, and induces disorganisation of the mitotic spindle. Moreover, CEP126 depletion or the transfection of a CEP126 truncation mutant in hTERT-RPE-1 and IMCD3 cells impairs the formation of the primary cilium. We propose that CEP126 is a regulator of microtubule organisation at the centrosome that acts through modulation of the transport of pericentriolar satellites, and consequently, of the organisation of cell structure. © 2014 The Authors. Biology of the Cell published by Wiley-VCH Verlag GmbH & Co. KGaA on behalf of Société de Biologie Cellulaire Francaise.

  3. GenomicusPlants: a web resource to study genome evolution in flowering plants.

    Science.gov (United States)

    Louis, Alexandra; Murat, Florent; Salse, Jérôme; Crollius, Hugues Roest

    2015-01-01

    Comparative genomics combined with phylogenetic reconstructions are powerful approaches to study the evolution of genes and genomes. However, the current rapid expansion of the volume of genomic information makes it increasingly difficult to interrogate, integrate and synthesize comparative genome data while taking into account the maximum breadth of information available. GenomicusPlants (http://www.genomicus.biologie.ens.fr/genomicus-plants) is an extension of the Genomicus webserver that addresses this issue by allowing users to explore flowering plant genomes in an intuitive way, across the broadest evolutionary scales. Extant genomes of 26 flowering plants can be analyzed, as well as 23 ancestral reconstructed genomes. Ancestral gene order provides a long-term chronological view of gene order evolution, greatly facilitating comparative genomics and evolutionary studies. Four main interfaces ('views') are available where: (i) PhyloView combines phylogenetic trees with comparisons of genomic loci across any number of genomes; (ii) AlignView projects loci of interest against all other genomes to visualize its topological conservation; (iii) MatrixView compares two genomes in a classical dotplot representation; and (iv) Karyoview visualizes chromosome karyotypes 'painted' with colours of another genome of interest. All four views are interconnected and benefit from many customizable features.

  4. A temperature-responsive gene in sorghum encodes a glycine-rich protein that interacts with calmodulin.

    Science.gov (United States)

    Singh, Supreet; Virdi, Amardeep Singh; Jaswal, Rajdeep; Chawla, Mrinalini; Kapoor, Sanjay; Mohapatra, Samar B; Manoj, Narayanan; Pareek, Ashwani; Kumar, Sanjay; Singh, Prabhjeet

    2017-06-01

    Imposition of different biotic and abiotic stress conditions results in an increase in intracellular levels of Ca(2+) which is sensed by various sensor proteins. Calmodulin (CaM) is one of the best studied transducers of Ca(2+) signals. CaM undergoes conformational changes upon binding to Ca(2+) and interacts with different types of proteins, thereby, regulating their activities. The present study reports the cloning and characterization of a sorghum cDNA encoding a protein (SbGRBP) that shows homology to glycine-rich RNA-binding proteins. The expression of SbGRBP in the sorghum seedlings is modulated by heat stress. The SbGRBP protein is localized in the nucleus as well as in cytosol, and shows interaction with CaM that requires the presence of Ca(2+). SbGRBP depicts binding to single- and also double-stranded DNA. Fluorescence spectroscopic analyses suggest that interaction of SbGRBP with nucleic acids may be modulated after binding with CaM. To our knowledge, this is the first study to provide evidence for interaction of a stress regulated glycine-rich RNA-binding protein with CaM. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  5. Lewis y enhances CAM-DR in ovarian cancer cells by activating the FAK signaling pathway and upregulating Bcl-2/Bcl-XL expression.

    Science.gov (United States)

    Yan, Limei; Wang, Changzhi; Lin, Bei; Liu, Juanjuan; Liu, Dawo; Hou, Rui; Wang, Yifei; Gao, Lili; Zhang, Shulan; Iwamori, Masao

    2015-06-01

    Oligosaccharides on the surface of adhesion molecules may contribute to the process of CAM-DR. To investigate the role of the Lewis y antigen in this process, we established a cell adhesion model mediated by the integrin α5β1-FN interaction in the ovarian cancer cell line, RMG-1-hFUT, which highly expresses Lewis y by transfection with α1,2-fucosyltransferase into RMG-1 cells. Our results indicate that the rates of carboplatin-induced apoptosis and necrosis are reduced in FN-adhered tumor cells, and carboplatin resistance is significantly decreased in the presence of anti-Lewis y antibody. CAM-DR in tumor cells has been correlated with elevated expression of the nuclear anti-apoptotic proteins Bcl-2 and Bcl-XL. Lewis y promotes the expression of the Bcl-2 and Bcl-XL genes by activating the focal adhesion kinase signaling pathway and accelerating their transcription. Thus, Lewis y leads to inhibition of apoptosis and enhancement of CAM-DR by activation of the FAK signaling pathway and upregulation of Bcl-2/Bcl-XL expression in ovarian cancer cell lines. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. Der evolutionäre Naturalismus in der Ethik

    Science.gov (United States)

    Kaiser, Marie I.

    Charles Darwin hat eindrucksvoll gezeigt, dass der Mensch ebenso wie alle anderen Lebewesen ein Produkt der biologischen Evolution ist. Die sich an Darwin anschließende Forschung hat außerdem plausibel gemacht, dass sich nicht nur viele der körperlichen Merkmale des Menschen, sondern auch (zumindest einige) seiner Verhaltensdispositionen in adaptiven Selektionsprozessen herausgebildet haben. Die Vorstellung, dass auch die menschliche Moralität evolutionär bedingt ist, scheint daher auf den ersten Blick ganz überzeugend. Schließlich hat die Evolutionstheorie in den vergangenen Jahrzehnten in vielen Bereichen (auch außerhalb der Biologie) ihre weitreichende Bedeutung unter Beweis gestellt. Warum sollte, so könnte man beispielsweise fragen, gerade die Fähigkeit des Menschen, moralische Normen aufzustellen und gemäß ihnen zu handeln, nicht evolutionär erklärt werden können? Und warum sollte eine solche evolutionäre Erklärung der menschlichen Moralität irrelevant für die Rechtfertigung moralischer Normen sein? Warum sollte die Ethik eine Bastion der Philosophen bleiben, für die evolutionsbiologische Forschungsergebnisse über den Menschen und seine nächsten Verwandten keinerlei Relevanz besitzen?

  7. Appearence of language

    CERN Multimedia

    Bonnet

    1975-01-01

    C'est grace à la collaboration du centre catholique d'études et l'association du personnel du Cern que cette conférence a pû être organisé. La présidente du centre catholique d'études présente le Prof.Bonnet de Louvin, jésuite, qui nous parlera de l'apparition du langage parlé dans le processus de la civilisation.Il est né en 1919 à Bruxelles et s'intéressé d'abord à la biologie et après à l'anthropologie et paléontologie. Il a fait 3 licences, en théologie, sciences et philosophie et le tout couronné d'un doctorat en anthropologie à l'université de Zurich. Le prof. a participé à des fouilles en Afrique, Espagne et en Iran, ensuite enseigné dans plusieurs unuversités aux Etats Unis, Belqique et en Afrique, actuellement il est directeur de la section de paléontologie de l'université de Louvin et aussi à la faculté de théologie. Il se tourne vers le passé pour mieux comprendre l'homme, le devenir de l'homme.

  8. [Magnetic nanoparticles as tools for cell therapy].

    Science.gov (United States)

    Wilhelm, Claire; Gazeau, Florence

    2012-01-01

    Labelling living cells with magnetic nanoparticles creates opportunities for numerous biomedical applications such as Magnetic Resonance Imaging (MRI) cell tracking, cell manipulation, cell patterning for tissue engineering and magnetically-assisted cell delivery. The unique advantage of magnetic-based methods is to activate or monitor cell behavior by a remote stimulus, the magnetic field. Cell labelling methods using superparamagnetic nanoparticles have been widely developed, showing no adverse effect on cell proliferation and functionalities while conferring magnetic properties to various cell types. This paper first describes how cells can become responsive to magnetic field by safely internalizing magnetic nanoparticles. We next show how magnetic cells can be detected by MRI, giving the opportunity for non-invasive in vivo monitoring of cell migration. We exemplify the fact that MRI cell tracking has become a method of choice to follow the fate of administrated cells in cell therapy assay, whether the cells are grafted locally or administrated in the circulation. Finally we give different examples of magnetic manipulation of cells and their applications to regenerative medicine. Magnetic cell manipulation are forecasted to be more and more developed, in order to improve tissue engineering technique and assist cell-based therapies. Owing to the clinical approval of iron-oxide nanoparticles as MRI contrast agent, there is no major obstacle in the translation to human clinics of the magnetic methods summarized in this paper. © Société de Biologie, 2013.

  9. Um e outro: Ferenczi e a epistemologia

    Directory of Open Access Journals (Sweden)

    Leonardo Câmara

    2014-08-01

    Full Text Available Le présent article se propose d'investiguer la manière dont Ferenczi a réfléchi sur quelques questions épistémologiques tout au long de son œuvre afin de produire la figure de l'" utraquisme ". Cette notion va se prêter, dans sa pensée, à établir une méthode de dialogue de la psychanalyse avec des savoirs qui lui sont étrangers - notamment la biologie -, envisageant de promouvoir l'élargissement du champ théorique psychanalytique. Cet élargissement va favoriser la création de concepts et, par conséquent, l'enrichissement des réflexions sur les modes de faire la clinique. En ces termes, l'utraquisme concrétise la prise de position épistémologique de Ferenczi, qui a consisté en un refus de s'allier de manière rigide à l'idéalisme ou au matérialisme - les courants philosophiques qu'il considère comme les deux attitudes fondamentales de l'homme, en ce qui concerne la connaissance.

  10. Présentations inhabituelles d'un syndrome de Plummer-Vinson chez l'africain de race noire: à propos de deux observations

    Science.gov (United States)

    Berthé, Adama; Diop, Madoky Magatte; Toure, Papa Souleymane; Tall, Cheikh Tidiane; Fulgence Faye, Abdoul; Diop, Bernard Marcel; Ka, Mamadou Mourtalla

    2014-01-01

    Le syndrome de Plummer Vinson (SPV) est une affection rare caractérisée par une dysphagie cervicale associée à une anémie ferriprive et un anneau sur l’œsophage supérieur. Parfois, son mode de présentation inhabituelle peut faire errer le diagnostic. Le rétrécissement annulaire peut être de découverte fortuite lors d'une endoscopie digestive haute. Nous rapportons deux observations de syndrome de Plummer-Vinson chez des sujets de genre masculin et féminin. Celles-ci ont comme point commun une découverte fortuite lors d'une endoscopie digestive haute. La première observation concernait un garçon de 14 ans aux antécédents de brûlure caustique de l’œsophage dans l'enfance avec dysphagie haute passagère ne l'inquiétant pas depuis lors. Il était reçu en urgence pour une endoscopie digestive haute motivée par une dysphagie de survenue brutale secondaire à une prise d'aliment solide. L'examen clinique avait objectivé une chéilite angulaire. La biologie montrait un abaissement de la ferritinémie sans anémie. L'endoscopie avait mis en évidence un anneau circulaire franchi avec ressaut au niveau de la bouche de Killian. Elle avait également permis l'extraction d'un corps étranger à type de noyau de « pain de singe » mais la lumière de l’œsophage était infranchissable à partir du niveau d'arrêt. Le transit œsophagien montrait un ralentissement du produit de contraste au niveau de l'sophage cervical et thoracique sans lésions morphologiques. Dans la deuxième observation, il s'agissait d'une jeune femme de 35 ans adressée à l unité d'endoscopie digestive pour objectiver une gastrite atrophique sur une suspicion de la maladie de Biermer. La fibroscopie mettait alors en évidence, un rétrécissement annulaire infranchissable à 18 centimètres des arcades dentaires. La biologie montrait une anémie avec augmentation de la ferritinémie. Dans les deux cas, le traitement martial était systématique associé à des séances de

  11. Multi-colour direct STORM with red emitting carbocyanines.

    Science.gov (United States)

    Lampe, André; Haucke, Volker; Sigrist, Stephan J; Heilemann, Mike; Schmoranzer, Jan

    2012-04-01

    Single molecule-based super-resolution methods have become important tools to study nanoscale structures in cell biology. However, the complexity of multi-colour applications has prevented them from being widely used amongst biologists. Direct stochastic optical reconstruction microscopy (dSTORM) offers a simple way to perform single molecule super-resolution imaging without the need for an activator fluorophore and compatible with many conventionally used fluorophores. The search for the ideal dye pairs suitable for dual-colour dSTORM has been compromised by the fact that fluorophores spectrally apt for dual-colour imaging differ with respect to the optimal buffer conditions required for photoswitching and the generation of prolonged non-fluorescent (OFF) states. We present a novel variant of dSTORM that combines advantages of spectral demixing with the buffer compatible blinking properties of red emitting carbocyanine dyes, spectral demixing dSTORM (SD-dSTORM). In contrast to previously published work, SD-dSTORM requires reduced laser power and fewer imaging frames for the faithful reconstruction of super-resolved biological nanostructures. In addition, SD-dSTORM allows the use of commercially available rather than custom-made probes and does not rely on potentially error-prone cross-talk correction, thus allowing reliable co-localisation. SD-dSTORM presents a significant advance towards user-friendly single molecule localisation-based super-resolution microscopy combining advantages of state-of-the-art methodologies to perform fast, reliable and efficient multi-colour dSTORM. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

  12. Ką apima sąvoka "dalykinė kalba"? Was umfasst der Begriff Fachsprache?

    Directory of Open Access Journals (Sweden)

    Eglė Kontutytė

    2007-01-01

    Full Text Available In den letzten Jahrzehnten ist die Fachsprache zu einem der wichtigsten Gegenstände der angewandten Linguistik geworden. In der lituanistischen Sprachwissenschaft wird aber dieser Begriff noch selten erwähnt und ist noch kaum definiert. Mehrere diesen Begriff bezeichnende Termini („dalykinë kalba“, „specialioji kalba“, „specialybës kalba“ ir „profesinë kalba“ werden verwendet, deren Inhalt aber nicht genau festgelegt wird. In der germanistischen Fachsprachenforschung wird der Begriff „Fachsprache“ mit Hilfe lexikalischer, grammatischer, kommunikativ-funktionaler, soziolinguistischer, pragmatischer, kognitiver, soziologischer Kriterien beschrieben. Die Fachsprache als Gegenstand der Linguistik ist heterogen. Mehrere Klassifizierungsmodelle der Fachsprache stellen die Komplexität und die Vielfalt der Gliederungskriterien dieses Gegenstands dar. Die meist verwendeten Kriterien sind das Fach und der Abstraktionsgrad der Sprache. Die Fixierung der Fachbereiche führt zu horizontaler Gliederung der Fachsprache. Unter Fächern und ihren Fachsprachen werden z.B. Wirtschaft, Geschichte, Biologie, Medizin, Literaturwissenschaft verstanden. Die horizontal gegliederten Fachsprachen werden vertikal geschichtet. Die vertikale Schichtung einer Fachsprache erfolgt aufgrund ihres Spezialisierungs- und Abstraktionsgrads.Der Forschungsgegenstand hat sich mit der Geschichte der Sprachwissenschaft vom Fachwort zur fachsprachlichen Syntax geändert. In der letzten Zeit steht im Mittelpunkt der Fachsprachenforschung der Fachtext, die Fachtextsorten sowie die Fachkommunikation als Hauptgegenstand der Fachsprachenforschung.Aufgrund der Vielfalt der Kommunikationsbereiche und Kommunikationspartner, zu denen auch z. B. Laien gehören, könnte die litauische Benennung „dalykinë kalba“ den oben dargestellten Begriff am genausten bezeichnen.

  13. Intérêts des semences commerciales améliorées de palmier à huile (Elæis guineensis Jacq.

    Directory of Open Access Journals (Sweden)

    Cochard Benoît

    2001-11-01

    Full Text Available Le palmier à huile (Elæis guineensis Jacq. est originaire d’Afrique où il est encore exploité de façon traditionnelle. L’intensification de sa culture a commencé au début du xxe siècle, en Asie du Sud-Est. Ce n’est qu’entre les deux guerres mondiales que cette intensification s’est manifestée en Afrique. En Amérique latine, cette culture ne s’est développée que depuis la fin des années 60. En 2000, la production d’huile s’élève à 21,7 millions de tonnes. Par ailleurs, les extensions et renouvellements de plantations demeurent très vifs. Ainsi, les surfaces plantées sont de 6 562 000 hectares dans le monde en 2000 [1]. Dans ces conditions, le marché mondial des semences est estimé à plus de 150 millions de graines par an. Autant les agro-industriels se fournissent le plus souvent auprès des obtenteurs, autant les planteurs villageois, en particulier en Afrique, ne s’adressent pas systématiquement à eux, et sont confrontés à des désagréments ultérieurs, lors de la mise en récolte de leur plantation. Les semences commerciales de qualité prennent en compte des contraintes liées à la biologie florale de cette plante ainsi qu’aux caractéristiques morphologiques de la graine. Elles sont fabriquées en respectant un cahier des charges rigoureux permettant d’éviter aux exploitants de très mauvaises désillusions.

  14. Contribution to the study of the biological properties of compounds labeled with radio-chromium {sup 51}Cr; Contribution a l'etude des proprietes biologiques des composes marques au radiochrome {sup 51}Cr

    Energy Technology Data Exchange (ETDEWEB)

    Ingrand, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-15

    Among the radioisotopes commonly used in biology and medicine which are controlled Individually in the Radioelement Departement of the Saclay Nuclear Research Centre before being sent to the users, the author has chosen chromium 51 incorporated in inorganic salts or in organic substrates for a study of the biological properties of the compounds. In the first part, he has compared the pathways followed by the radioactive sodium chromate and chromic chloride mixed with blood or given to the whole animal, the object being to determine whether a reduction of hexavalent chromium occurs, both in vitro and in vivo. In the second part, the author has tried to show the validity of using, various substrates labeled with chromium 51, red cells, haemoglobin, plasma proteins and cytochrome c. The results obtained have contributed to underline the interest of using such compounds for biological applications. (author) [French] Parmi les radioisotopes d'utilisation courants en biologie et en medecine qui sont l'objet d'un controle particulier dans le Departement des Radioelements du Centre d'Etudes Nucleaires de Saclay avant leur diffusion aux utilisateurs, l'auteur a choisi le chrome 51 incorpore a des sels mineraux ou a des substrats organiques, afin d'en etudier les proprietes biologiques. Dans la premiere partie, il a compare le sort du chromate de sodium et du chlorure chromique radioactifs melanges a du sang ou administres a l'animal entier en s'efforcant de mettre en evidence une reduction du chrome hexavalent aussi bien in vitro qu'in vivo. Dans la deuxieme partie, il a cherche a etablir la validite de l'emploi de differents substrats marques au chrome 51, l'hematie, l'hemoglobine, les proteines plasmatiques et le cytochrome c. Les resultats obtenus ont permis de souligner le reel interet des applications biologiques des composes marques par le radioisotope. (auteur)

  15. Effects of phenothiazine-structured compounds on APP processing in Alzheimer's disease cellular model.

    Science.gov (United States)

    Yuksel, Melike; Biberoglu, Kevser; Onder, Seda; Akbulut, K Gonca; Tacal, Ozden

    2017-07-01

    The excess accumulation of amyloid-β (Aβ) peptides derived from the sequential cleavage of amyloid precursor protein (APP) by secretases, is one of the toxic key events leading to neuronal loss in Alzheimer's disease (AD). Studies have shown that cholinergic activity may also be involved in the regulation of APP metabolism. In the current study, we have investigated the roles of toluidine blue O (TBO) and thionine (TH), newly recognized phenothiazine-derived cholinesterase inhibitors, on the metabolism of APP in Chinese hamster ovary cells stably expressing human APP751 and presenilin 1 (PS70 cells). We assessed the effects of both compounds on the levels of Aβ, soluble APP-α (sAPPα), intracellular APP and β-site APP-cleaving enzyme 1 (BACE1). After treatment of PS70 cells with TBO or TH without any side effect on cell viability, the levels of secreted Aβ40, Aβ42 and sAPPα were assayed by specific sandwich ELISAs while APP and BACE1 in cell lysates were analyzed using Western blot. The secreted Aβ40, Aβ42 and sAPPα in TBO- and TH-treated cells were found to be reduced in a dose-dependent manner compared to vehicle-treated cells. Results suggest that TH mitigated the Aβ pathology by lowering APP levels whereas reduced Aβ caused by TBO treatment seems to be the outcome of both less substrate availability and amyloidogenic APP processing. Taken together, our results represent the first report demonstrating that TBO and TH can affect amyloid metabolism in vitro. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Mass spectrometry analysis of intact Francisella bacteria identifies lipid A structure remodeling in response to acidic pH stress.

    Science.gov (United States)

    Robert, Camille B; Thomson, Michael; Vercellone, Alain; Gardner, Francesca; Ernst, Robert K; Larrouy-Maumus, Gérald; Nigou, Jérôme

    2017-08-12

    Structural modification of lipid A, the lipid anchor of LPS, is one of the strategies used by Gram-negative bacteria to evade host innate immunity. Francisella tularensis is a human pathogen that infects and replicates within phagocytic cells. It produces an atypical lipid A, whose structure precludes an efficient recognition by both innate immune players, TLR4 and cationic antimicrobial peptides. Interestingly, a recent report indicates that the lipid A of Francisella (LVS vaccinal strain) undergoes polar modifications when bacteria are grown in human macrophages as compared to in broth. To characterize the structural modifications of lipid A that may be induced intracellularly, Francisella novicida, a surrogate strain for the highly virulent F. tularensis, was submitted to different stress conditions mimicking the harsh environment encountered in the macrophages. To analyze lipid A directly from intact bacteria without any chemical treatment or purification steps, we used a rapid and sensitive MALDI-TOF mass spectrometry approach. Among the many conditions tested, only bacteria exposure to acidic pHs (from 6 to 5) induced a change in lipid A structure. These changes were characterized by an increase in the relative abundance of molecular species bearing an additional hexose unit on the diglucosamine backbone, similar to species present when bacteria are grown under reduced environmental temperature. This lipid A glyco-form, which is observed in trace amounts in normal in vitro growth conditions at 37 °C, may contribute to the intracellular parasitism of macrophages by Francisella. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  17. Targeting signal transducers and activators of transcription (STAT) in human cancer by dietary polyphenolic antioxidants.

    Science.gov (United States)

    Amani, Hamed; Ajami, Marjan; Maleki, Solmaz Nasseri; Pazoki-Toroudi, Hamidreza; Daglia, Maria; Tsetegho Sokeng, Arold Jorel; Di Lorenzo, Arianna; Nabavi, Seyed Fazel; Devi, Kasi Pandima; Nabavi, Seyed Mohammad

    2017-08-11

    Over the course of the last three decades, a large body of evidence has shown that polyphenols, the secondary metabolites occurring in plant foods and beverages, exert protective effects due to their antioxidant activity mediated through different mechanisms ranging from direct radical scavenging and metal chelating activities, to the capacity to inhibit pro-oxidant enzymes and to target specific cell-signalling pathways. In the last decade, dietary components, and polyphenols in particular have gained considerable attention as chemopreventive agents against different types of cancer. The signal transducers and activators of transcription (STAT) family is a group of cytoplasmic transcription factors which interact with specific sequences of DNA, inducing the expression of specific genes which in turn give rise to adaptive and highly specific biological responses. Growing evidence suggests that, of the seven STAT members identified, STAT3 is over-expressed in many human tumors (i.e. solid tumors and hematological malignancies) promoting the onset and development of cancer in humans by inhibiting apoptosis or by inducing cell proliferation, angiogenesis, invasion, and metastasis. This review article aims to assess the most recent studies on the role of STATs, with focus on STAT3, in oncogenesis, and the promising effects of some polyphenols on STAT expression. Moreover, the mechanisms behind the anti-inflammatory and antioxidant activities of polyphenols which have an influence on STAT expression are discussed, with a focus on their ability to target specific cell-signalling pathways. Copyright © 2017 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.

  18. Glucosylceramidases and malignancies in mammals.

    Science.gov (United States)

    Astudillo, Leonardo; Therville, Nicole; Colacios, Céline; Ségui, Bruno; Andrieu-Abadie, Nathalie; Levade, Thierry

    2016-06-01

    Sphingolipids represent a major class of lipids that are essential constituents of eukaryotic cells. They are predominantly located in plasma membrane microdomains, and play an important structural role in regulating membrane fluidity. They are also bioactive effectors involved in diverse key cellular functions such as apoptosis and proliferation. The implication of some sphingolipids in cancer is well established whereas that of some others is still a matter of intense investigation. Glucosylceramide is the backbone of more than 300 structurally different glycosphingolipids including gangliosides and sulfatides, and is essential for mammalian development. Therefore, glucosylceramidases (also named GBA1, GBA2 and GBA3 β-glucosidases), the enzymes that hydrolyse β-glucosylceramide, play important functions. GBA1 is a lysosomal hydrolase whose deficiency causes Gaucher disease, the most prevalent inherited lysosomal storage disorder. GBA2 is a ubiquitous non-lysosomal glucosylceramidase whose mutations have been associated with some forms of hereditary spastic paraplegia. GBA3 is a cytosolic β-glucosidase, mostly present in the kidney, liver, spleen, intestine and lymphocytes of mammals, the function of which is still unclear. Whereas glucosylceramide synthase is implicated in multidrug resistance, the role of glucosylceramide breakdown in cancer is not yet fully appreciated. Defective GBA1 enzyme activity in humans, i.e., Gaucher disease, is associated with an increased risk of multiple myeloma and other malignancies. Putative molecular links between Gaucher disease and cancer, which might implicate the malignant cell and/or its microenvironment, are reviewed. The functions of GBA2 and GBA3 in cancer progression are also discussed. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  19. Evolution of inhibitor-resistant natural mutant forms of HIV-1 protease probed by pre-steady state kinetic analysis.

    Science.gov (United States)

    Zakharova, Maria Yu; Kuznetsova, Alexandra A; Kaliberda, Elena N; Dronina, Maria A; Kolesnikov, Alexander V; Kozyr, Arina V; Smirnov, Ivan V; Rumsh, Lev D; Fedorova, Olga S; Knorre, Dmitry G; Gabibov, Alexander G; Kuznetsov, Nikita A

    2017-08-23

    Pre-steady state kinetic analysis of mechanistic features of substrate binding and processing is crucial for insight into the evolution of inhibitor-resistant forms of HIV-1 protease. These data may provide a correct vector for rational drug design assuming possible intrinsic dynamic effects. These data should also give some clues to the molecular mechanism of protease action and resistance to inhibitors. Here we report pre-steady state kinetics of the interaction of wild type or mutant forms of HIV-1 protease with a FRET-labeled peptide. The three-stage "minimal" kinetic scheme with first and second reversible steps of substrate binding and with following irreversible peptide cleavage step adequately described experimental data. For the first time, a set of "elementary" kinetic parameters of wild type HIV-1 protease and its natural mutant inhibitor-resistant forms MDR-HM, ANAM-11 and prDRV4 were compared. Inhibitors of the first and second generation were used to estimate the inhibitory effects on HIV-1 protease activity. The resulting set of kinetic data supported that the mutant forms are kinetically unaffected by inhibitors of the first generation, proving their functional resistance to these compounds. The second generation inhibitor darunavir inhibited mutant forms MDR-HM and ANAM-11, but was ineffective against prDRV4. Our kinetic data revealed that these inhibitors induced different conformational changes in the enzyme and, thereby they have different mode of binding in the enzyme active site. These data confirmed hypothesis that the driving force of the inhibitor-resistance evolution is disruption of enzyme-inhibitor complex by changing of the contact network in the inhibitor binding site. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. Misunderstandings and controversies about the insulin-secreting properties of antidiabetic sulfonylureas.

    Science.gov (United States)

    Henquin, Jean-Claude

    2017-07-12

    After 60 years of use in the treatment of type 2 diabetes, hypoglycemic sulfonylureas remain a recommended option in current therapeutic charts. Their binding to sulfonylurea receptor-1, the regulatory subunit of ATP-sensitive potassium channels in the plasma membrane of pancreatic β-cells, leads to closure of the channels, membrane depolarization and influx of Ca(2+) through voltage-gated calcium channels. The resulting increase in cytosolic Ca(2+) triggers exocytosis of insulin granules. Sulfonylureas and glucose thus produce the same triggering signal but, unlike sulfonylureas, glucose does so via acceleration of β-cell metabolism. Glucose metabolism also produces amplifying signals that approximately double the secretory response to triggering Ca(2+). One persistent misunderstanding about sulfonylureas is the alleged glucose-independence of their effects. It is correct that high concentrations of these drugs can induce insulin secretion in low glucose and cause hypoglycemic episodes in treated patients. Conversely, that untoward effect is erroneously considered as evidence that their therapeutic action is independent of glucose. Another evolving controversy about the action of sulfonylureas in β-cells is whether, like glucose, they also produce intracellular amplifying signals able to augment the efficacy of Ca(2+) on exocytosis. The aims of this review are to dissipate the misunderstanding and discuss the controversy. Reasons why proposed amplifying effects of sulfonylureas are unlikely to be relevant for their action in vivo will be presented. Possible interactions of sulfonylureas and glucagon-like peptide-1 in β-cells will be discussed. Mechanisms whereby the ambient glucose concentration modulates the insulin-secreting action of therapeutic concentrations of sulfonylureas will be explained. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Activity modulation of the oligopeptidase B from Serratia proteamaculans by site-directed mutagenesis of amino acid residues surrounding catalytic triad histidine.

    Science.gov (United States)

    Mikhailova, Anna G; Rakitina, Tatiana V; Timofeev, Vladimir I; Karlinsky, David M; Korzhenevskiy, Dmitry A; Agapova, Yulia К; Vlaskina, Anna V; Ovchinnikova, Marina V; Gorlenko, Valentina A; Rumsh, Lev D

    2017-08-01

    Oligopeptidase B (OpdB; EC 3.4.21.83) is a trypsin-like peptidase belonging to the family of serine prolyl oligopeptidases; two-domain structure of the enzyme includes C-terminal peptidase catalytic domain and N-terminal seven-bladed β-propeller domain. Importance of the interface between these domains and particularly of the 5 salt bridges for enzyme activity was established for protozoan OpdBs. However, these salt bridges are not conserved in γ -proteobacterial OpdBs including the peptidase from Serratia proteamaculans (PSP). In this work, using comparative modelling and protozoan OpdBs' crystal structures we created 3D models of PSP in open and closed forms to elucidate the mechanism underlying inactivation of the truncated form of PSP1-655 obtained earlier. Analysis of the models shows that in the closed form of PSP charged amino acid residues of histidine loop, surrounding the catalytic triad His652, participate in formation of the inter-domain contact interface between catalytic and β-propeller domains, while in the open form of PSP disconnection of the catalytic triad and distortion of these contacts can be observed. Complete destruction of this interface by site-directed mutagenesis causes inactivation of PSP while elimination of the individual contacts leads to differential effects on the enzyme activity and substrate specificity. Thus, we identified structural factors regulating activity of PSP and supposedly of other γ-proteobacterial OpdBs and discovered the possibility of directed modulation of their enzymatic features. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  2. Empirical genome evolution models root the tree of life.

    Science.gov (United States)

    Harish, Ajith; Kurland, Charles G

    2017-07-01

    A reliable phylogenetic reconstruction of the evolutionary history of contemporary species depends on a robust identification of the universal common ancestor (UCA) at the root of the Tree of Life (ToL). That root polarizes the tree so that the evolutionary succession of ancestors to descendants is discernable. In effect, the root determines the branching order and the direction of character evolution. Typically, conventional phylogenetic analyses implement time-reversible models of evolution for which character evolution is un-polarized. Such practices leave the root and the direction of character evolution undefined by the data used to construct such trees. In such cases, rooting relies on theoretic assumptions and/or the use of external data to interpret unrooted trees. The most common rooting method, the outgroup method is clearly inapplicable to the ToL, which has no outgroup. Both here and in the accompanying paper (Harish and Kurland, 2017) we have explored the theoretical and technical issues related to several rooting methods. We demonstrate (1) that Genome-level characters and evolution models are necessary for species phylogeny reconstructions. By the same token, standard practices exploiting sequence-based methods that implement gene-scale substitution models do not root species trees; (2) Modeling evolution of complex genomic characters and processes that are non-reversible and non-stationary is required to reconstruct the polarized evolution of the ToL; (3) Rooting experiments and Bayesian model selection tests overwhelmingly support the earlier finding that akaryotes and eukaryotes are sister clades that descend independently from UCA (Harish and Kurland, 2013); (4) Consistent ancestral state reconstructions from independent genome samplings confirm the previous finding that UCA features three fourths of the unique protein domain-superfamilies encoded by extant genomes. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie

  3. Pro-oxidant effect of ALA is implicated in mitochondrial dysfunction of HepG2 cells.

    Science.gov (United States)

    Laafi, Jihane; Homedan, Chadi; Jacques, Caroline; Gueguen, Naig; Schmitt, Caroline; Puy, Hervé; Reynier, Pascal; Carmen Martinez, Maria; Malthièry, Yves

    2014-11-01

    Heme biosynthesis begins in the mitochondrion with the formation of delta-aminolevulinic acid (ALA). In acute intermittent porphyria, hereditary tyrosinemia type I and lead poisoning patients, ALA is accumulated in plasma and in organs, especially the liver. These diseases are also associated with neuromuscular dysfunction and increased incidence of hepatocellular carcinoma. Many studies suggest that this damage may originate from ALA-induced oxidative stress following its accumulation. Using the MnSOD as an oxidative stress marker, we showed here that ALA treatment of cultured cells induced ROS production, increasing with ALA concentration. The mitochondrial energetic function of ALA-treated HepG2 cells was further explored. Mitochondrial respiration and ATP content were reduced compared to control cells. For the 300 μM treatment, ALA induced a mitochondrial mass decrease and a mitochondrial network imbalance although neither necrosis nor apoptosis were observed. The up regulation of PGC-1, Tfam and ND5 genes was also found; these genes encode mitochondrial proteins involved in mitochondrial biogenesis activation and OXPHOS function. We propose that ALA may constitute an internal bioenergetic signal, which initiates a coordinated upregulation of respiratory genes, which ultimately drives mitochondrial metabolic adaptation within cells. The addition of an antioxidant, Manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP), resulted in improvement of maximal respiratory chain capacity with 300 μM ALA. Our results suggest that mitochondria, an ALA-production site, are more sensitive to pro-oxidant effect of ALA, and may be directly involved in pathophysiology of patients with inherited or acquired porphyria. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  4. ERK1 and ERK2 activation modulates diet-induced obesity in mice.

    Science.gov (United States)

    Khan, Amira Sayed; Subramaniam, Selvakumar; Dramane, Gado; Khelifi, Douadi; Khan, Naim Akhtar

    2017-06-01

    Obesity is a worldwide problem, and dietary lipids play an important role in its pathogenesis. Recently, Erk1 knock-out (ERK1(-/-)) mice have been shown to exhibit low preference for dietary fatty acids. Hence, we maintained Erk1(-/-) mice on a high-fat diet (HFD) to assess the implication of this mitogen-activated protein (MAP) kinase in obesity. The Erk1(-/-) mice, fed the HFD, were more obese than wild-type (WT) animals, fed the same diet. Erk1(-/-) obese mice gained more fat and liver mass than WT obese animals. No difference was observed in daily food and energy intake in HFD-fed both group of animals. However, feed efficiency was higher in Erk1(-/-) than WT animals. Blood cholesterol, triglyceride and insulin concentrations were higher in Erk1(-/-) obese mice compared to WT obese animals. Accordingly, homeostatic model assessment of insulin resistance (HOMA-IR) value was higher in Erk1(-/-) obese mice compared to WT obese animals. Interestingly, only Erk1(-/-) obese mice, but not WT-obese animals, exhibited high degree of phosphorylation of liver MEK, the upstream regulator of ERK1/2. This phenomenon was associated with high liver ERK2 phosphorylation in Erk1(-/-) obese mice which also had high liver acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase (FAS) mRNA expression, suggesting high lipogenesis in these animals. The Erk1(-/-) obese mice also had low PPAR-α and CPT1β mRNA, indicating low fatty acid oxidation. Our observations suggest that ERK1 and ERK2 might play key roles in the regulation of obesity. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  5. Electrospray ionization ion mobility mass spectrometry provides novel insights into the pattern and activity of fetal hippocampus gangliosides.

    Science.gov (United States)

    Sarbu, Mirela; Vukelić, Željka; Clemmer, David E; Zamfir, Alina D

    2017-08-01

    Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. i-motif structures in long cytosine-rich sequences found upstream of the promoter region of the SMARCA4 gene.

    Science.gov (United States)

    Benabou, Sanae; Aviñó, Anna; Lyonnais, S; González, C; Eritja, Ramon; De Juan, Anna; Gargallo, Raimundo

    2017-09-01

    Cytosine-rich oligonucleotides are capable of forming complex structures known as i-motif with increasingly studied biological properties. The study of sequences prone to form i-motifs located near the promoter region of genes may be difficult because these sequences not only contain repeats of cytosine tracts of disparate length but also these may be separated by loops of varied nature and length. In this work, the formation of intramolecular i-motif structures by a long sequence located upstream of the promoter region of the SMARCA4 gene has been demonstrated. Nuclear Magnetic Resonance, Circular Dichroism, Gel Electrophoresis, Size-Exclusion Chromatography, and multivariate analysis have been used. Not only the wild sequence (5'-TC3T2GCTATC3TGTC2TGC2TCGC3T2G2TCATGA2C4-3') has been studied but also several other truncated and mutated sequences. Despite the apparent complex sequence, the results showed that the wild sequence may form a relatively stable and homogeneous unimolecular i-motif structure, both in terms of pH or temperature. The model ligand TMPyP4 destabilizes the structure, whereas the presence of 20% (w/v) PEG200 stabilized it slightly. This finding opens the door to the study of the interaction of these kind of i-motif structures with stabilizing ligands or proteins. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  7. Glycogen synthase from the parabasalian parasite Trichomonas vaginalis: An unusual member of the starch/glycogen synthase family.

    Science.gov (United States)

    Wilson, Wayne A; Pradhan, Prajakta; Madhan, Nayasha; Gist, Galen C; Brittingham, Andrew

    2017-07-01

    Trichomonas vaginalis, a parasitic protist, is the causative agent of the common sexually-transmitted infection trichomoniasis. The organism has long been known to synthesize substantial glycogen as a storage polysaccharide, presumably mobilizing this compound during periods of carbohydrate limitation, such as might be encountered during transmission between hosts. However, little is known regarding the enzymes of glycogen metabolism in T. vaginalis. We had previously described the identification and characterization of two forms of glycogen phosphorylase in the organism. Here, we measure UDP-glucose-dependent glycogen synthase activity in cell-free extracts of T. vaginalis. We then demonstrate that the TVAG_258220 open reading frame encodes a glycosyltransferase that is presumably responsible for this synthetic activity. We show that expression of TVAG_258220 in a yeast strain lacking endogenous glycogen synthase activity is sufficient to restore glycogen accumulation. Furthermore, when TVAG_258220 is expressed in bacteria, the resulting recombinant protein has glycogen synthase activity in vitro, transferring glucose from either UDP-glucose or ADP-glucose to glycogen and using both substrates with similar affinity. This protein is also able to transfer glucose from UDP-glucose or ADP-glucose to maltose and longer oligomers of glucose but not to glucose itself. However, with these substrates, there is no evidence of processivity and sugar transfer is limited to between one and three glucose residues. Taken together with our earlier work on glycogen phosphorylase, we are now well positioned to define both how T. vaginalis synthesizes and utilizes glycogen, and how these processes are regulated. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Alkaline pH induces IRR-mediated phosphorylation of IRS-1 and actin cytoskeleton remodeling in a pancreatic beta cell line.

    Science.gov (United States)

    Deyev, Igor E; Popova, Nadezhda V; Serova, Oxana V; Zhenilo, Svetlana V; Regoli, Marì; Bertelli, Eugenio; Petrenko, Alexander G

    2017-07-01

    Secretion of mildly alkaline (pH 8.0-8.5) juice to intestines is one of the key functions of the pancreas. Recent reports indicate that the pancreatic duct system containing the alkaline juice may adjoin the endocrine cells of pancreatic islets. We have previously identified the insulin receptor-related receptor (IRR) that is expressed in islets as a sensor of mildly alkaline extracellular media. In this study, we show that those islet cells that are in contact with the excretory ducts are also IRR-expressing cells. We further analyzed the effects of alkaline media on pancreatic beta cell line MIN6. Activation of endogenous IRR but not of the insulin receptor was detected that could be inhibited with linsitinib. The IRR autophosphorylation correlated with pH-dependent linsitinib-sensitive activation of insulin receptor substrate 1 (IRS-1), the primary adaptor in the insulin signaling pathway. However, in contrast with insulin stimulation, no protein kinase B (Akt/PKB) phosphorylation was detected as a result of alkali treatment. We observed overexpression of several early response genes (EGR2, IER2, FOSB, EGR1 and NPAS4) upon alkali treatment of MIN6 cells but those were IRR-independent. The alkaline medium but not insulin also triggered actin cytoskeleton remodeling that was blocked by pre-incubation with linsitinib. We propose that the activation of IRR by alkali might be part of a local loop of signaling between the exocrine and endocrine parts of the pancreas where alkalinization of the juice facilitate insulin release that increases the volume of secreted juice to control its pH and bicabonate content. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  9. Akaryotes and Eukaryotes are independent descendants of a universal common ancestor.

    Science.gov (United States)

    Harish, Ajith; Kurland, Charles G

    2017-07-01

    We reconstructed a global tree of life (ToL) with non-reversible and non-stationary models of genome evolution that root trees intrinsically. We implemented Bayesian model selection tests and compared the statistical support for four conflicting ToL hypotheses. We show that reconstructions obtained with a Bayesian implementation (Klopfstein et al., 2015) are consistent with reconstructions obtained with an empirical Sankoff parsimony (ESP) implementation (Harish et al., 2013). Both are based on the genome contents of coding sequences for protein domains (superfamilies) from hundreds of genomes. Thus, we conclude that the independent descent of Eukaryotes and Akaryotes (archaea and bacteria) from the universal common ancestor (UCA) is the most probable as well as the most parsimonious hypothesis for the evolutionary origins of extant genomes. Reconstructions of ancestral proteomes by both Bayesian and ESP methods suggest that at least 70% of unique domain-superfamilies known in extant species were present in the UCA. In addition, identification of a vast majority (96%) of the mitochondrial superfamilies in the UCA proteome precludes a symbiotic hypothesis for the origin of eukaryotes. Accordingly, neither the archaeal origin of eukaryotes nor the bacterial origin of mitochondria is supported by the data. The proteomic complexity of the UCA suggests that the evolution of cellular phenotypes in the two primordial lineages, Akaryotes and Eukaryotes, was driven largely by duplication of common superfamilies as well as by loss of unique superfamilies. Finally, innovation of novel superfamilies has played a surprisingly small role in the evolution of Akaryotes and only a marginal role in the evolution of Eukaryotes. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Membrane-bound human orphan cytochrome P450 2U1: Sequence singularities, construction of a full 3D model, and substrate docking.

    Science.gov (United States)

    Ducassou, Lionel; Dhers, Laura; Jonasson, Gabriella; Pietrancosta, Nicolas; Boucher, Jean-Luc; Mansuy, Daniel; André, François

    2017-09-01

    Human cytochrome P450 2U1 (CYP2U1) is an orphan CYP that exhibits several distinctive characteristics among the 57 human CYPs with a highly conserved sequence in almost all living organisms. We compared its protein sequence with those of the 57 human CYPs and constructed a 3D structure of a full-length CYP2U1 model bound to a POPC membrane. We also performed docking experiments of arachidonic acid (AA) and N-arachidonoylserotonin (AS) in this model. The protein sequence of CYP2U1 displayed two unique characteristics when compared to those of the human CYPs, the presence of a longer N-terminal region upstream of the putative trans-membrane helix (TMH) containing 8 proline residues, and of an insert of about 20 amino acids containing 5 arginine residues between helices A' and A. Its N-terminal part upstream of TMH involved an additional short terminal helix, in a manner similar to what was reported in the crystal structure of Saccharomyces cerevisiae CYP51. Our model also showed a specific interaction between the charged residues of insert AA' and phosphate groups of lipid polar heads, suggesting a possible role of this insert in substrate recruitment. Docking of AA and AS in this model showed these substrates in channel 2ac, with the terminal alkyl chain of AA or the indole ring of AS close to the heme, in agreement with the reported CYP2U1-catalyzed AA and AS hydroxylation regioselectivities. This model should be useful to find new endogenous or exogenous CYP2U1 substrates and to interpret the regioselectivity of their hydroxylation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Production of trans and conjugated fatty acids in dairy ruminants and their putative effects on human health: A review.

    Science.gov (United States)

    Ferlay, Anne; Bernard, Laurence; Meynadier, Annabelle; Malpuech-Brugère, Corinne

    2017-08-10

    Consumption of milk and dairy products is important in Western industrialised countries. Fat content is an important constituent contributing to the nutritional quality of milk and dairy products. In order to improve the health of consumers, there is high interest in improving their fatty acid (FA) composition, which depends principally on rumen and mammary metabolism. This paper reviews the lipid metabolism in ruminants, with a particular focus on the production of trans and conjugated linoleic acids (CLA) and conjugated linolenic acids (CLnA) in the rumen. After the lipolysis of dietary lipids, an extensive biohydrogenation of unsaturated FA occurs by rumen bacteria, leading to numerous cis and trans isomers of 18:1, non-conjugated of 18:2, CLA and CLnA. The paper examines the different putative pathways of ruminal biohydrogenation of cis9-18:1, 18:2n-6, 18:3n-3 and long-chain FA and the bacteria implicated. Then mechanisms relative to the de novo mammary synthesis are presented. Ruminant diet is the main factor regulating the content and the composition of milk fat. Effects of nature of forage and lipid supplementation are analysed in cows and small ruminants species. Finally, the paper briefly presents the effects of these FA on animal models and human cell lines. We describe the properties of ruminant trans 18:1, when compared to industrial trans 18:1, CLA and CLnA on human health from meta-analyses of intervention studies and then explore the underlying mechanisms. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  12. The C-terminus of ribosomal protein uS4 contributes to small ribosomal subunit biogenesis and the fidelity of translation.

    Science.gov (United States)

    Kamath, Divya; Allgeyer, Benjamin B; Gregory, Steven T; Bielski, Margaret C; Roelofsz, David M; Sabapathypillai, Sharon L; Vaid, Nikhil; O'Connor, Michael

    2017-07-01

    Ribosomal protein uS4 is an essential ribosomal component involved in multiple functions, including mRNA decoding. Structural analyses indicate that during decoding, the interface between the C-terminus of uS4 and protein uS5 is disrupted and in agreement with this, C-terminal uS4 truncation mutants are readily isolated on the basis of their increased miscoding phenotypes. The same mutants can also display defects in small subunit assembly and 16S rRNA processing and some are temperature sensitive for growth. Starting with one such temperature sensitive Escherichia coli uS4 mutant, we have isolated temperature insensitive derivatives carrying additional, intragenic mutations that restore the C-terminus and ameliorate the ribosomal defects. At least one of these suppressors has no detectable ribosome biogenesis phenotype, yet still miscodes, suggesting that the C-terminal requirements for ribosome assembly are less rigid than for mRNA decoding. In contrast to the uS4 C-terminal mutants that increase miscoding, two Salmonella enterica uS4 mutants with altered C-termini have been reported as being error-restrictive. Here, reconstruction experiments demonstrate that contrary to the previous reports, these mutants have a distinct error-prone, increased misreading phenotype, consistent with the behavior of the equivalent E. coli mutants and their likely structural effects on uS4-uS5 interactions. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  13. Morin attenuates diethylnitrosamine-induced rat liver fibrosis and hepatic stellate cell activation by co-ordinated regulation of Hippo/Yap and TGF-β1/Smad signaling.

    Science.gov (United States)

    Perumal, NaveenKumar; Perumal, MadanKumar; Halagowder, Devaraj; Sivasithamparam, NiranjaliDevaraj

    2017-09-01

    Despite great progress in understanding the activation of hepatic stellate cells (HSCs) during liver fibrosis, therapeutic approaches to inhibit HSC activation remain very limited. Recent reports highlight Yes-associated protein (Yap) and transforming growth factor-β1 (TGF-β1) as critical regulators of HSC activation and henceforth a compound targeting Hippo/Yap and TGF-β1/Smad pathways would be a potential anti-fibrotic candidate. Morin, a dietary flavonoid, was earlier reported to inhibit HSC proliferation and induction of apoptosis of cultured HSCs, mainly by suppressing Wnt/β-catenin and NF-κB signaling, but its effect on Hippo/Yap and TGF-β1/Smad pathways was not determined. To address this concern, this study was carried out in cultured LX-2 cells and diethylnitrosamine-induced fibrotic rats. Morin activated hippo signaling through significantly increased expression of Mst1 and Lats1 with decreased expression of transcriptional effectors Yap/TAZ, thereby prevented HSC activation and also suppressed the expression of exacerbated TGF-β/Smad signaling molecules such as TGF-β1, p-Smad2/3, collagen-I, MMP-2, MMP-9 and TIMP-1 in cultured LX-2 and DEN induced fibrotic rats. Both the in vitro and in vivo results clearly showed that, morin by acting on Hippo/Yap and TGF-β1/Smad pathways, ameliorated experimental liver fibrosis, indicating that morin has potential for effective treatment of liver fibrosis. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  14. Cytotoxic effect of a novel naphthylchalcone against multiple cancer cells focusing on hematologic malignancies.

    Science.gov (United States)

    Maioral, Mariana Franzoni; Bodack, Camila do Nascimento; Stefanes, Natália Marceli; Bigolin, Álisson; Mascarello, Alessandra; Chiaradia-Delatorre, Louise Domeneghini; Yunes, Rosendo Augusto; Nunes, Ricardo José; Santos-Silva, Maria Cláudia

    2017-09-01

    Chalcones are natural compounds described in the literature by its several properties including cytotoxic activity against several tumor types. Considering that the search for new chemotherapeutic agents is still necessary, the aim of this study was to investigate the cytotoxic mechanisms involved in cell death induced by a synthetic chalcone (A23) on different tumor cells. Chalcone A23 reduced the cell viability of twelve tumor cell lines in a concentration and time dependent manner and it was more cytotoxic against acute leukemia cells. Interestingly, the compound was non cytotoxic to normal cells and non-hemolytic to normal red blood cells. Chalcone A23 decreased the expression of cell proliferation marker KI-67 and blocked the G2/M phase in both K562 and Jurkat cell lines. Cells treated with A23 showed morphological features suggestive of apoptosis, the "latter pattern" in agarose gel, the externalization of phosphatidylserine and caspase-3 and PARP cleavage. Chalcone A23 significantly reduced the mitochondrial membrane potential, decreased the expression of anti-apoptotic proteins Bcl-2 and survivin and increased the expression of pro-apoptotic protein Bax, confirming the involvement of the intrinsic pathway. The increased mitochondrial permeability resulted in the release of AIF, cytochrome c and endonuclease G from the mitochondria to the cytosol. In addition, chalcone A23 increased the expression of FasR and induced Bid cleavage, showing the involvement of the extrinsic pathway. Finally, chalcone A23 seems to have a synergic effect with the chemotherapy drugs cytarabine and vincristine. These results suggest that A23 is an interesting compound with strong and selective anti-tumor activity. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  15. Inter-relations between osteoarthritis and metabolic syndrome: A common link?

    Science.gov (United States)

    Le Clanche, S; Bonnefont-Rousselot, D; Sari-Ali, E; Rannou, F; Borderie, D

    2016-02-01

    Osteoarthritis (OA) is a degenerative disorder of the joint, principally occurring during aging, and characterized by a focal degradation of cartilage. It is the most prevalent rheumatic disease in industrialized countries and represents the second cause of disability in France. However, the etiology of OA remains unclear. There is only one cell type found in cartilage, chondrocyte, which is responsible for its repair and the synthesis of the elements of the extra-cellular matrix. A dysfunction of these cells results in an imbalance between repair and degradation in cartilage, leading to its destruction. Recently, a link between OA and metabolic syndrome (MetS) has been suggested, introducing a notion of metabolic OA, and a new vision of the disease. MetS is characterized by a cluster of factors (insulin resistance, hypertension, dyslipidemia, visceral obesity), although there is still no clear definition of it. During the 20th century, MetS dramatically increased with changes in population lifestyle, becoming a major health issue in industrialized countries. MetS concerns 10-30% of the worldwide population, but is prevalent in 59% of OA patients. Patients with both OA and MetS have more severe symptoms, occurring sooner than in the general population. Indeed, OA is generally a disease concerning the population over 65 years old, but with an associated MetS the target population is around 50 years old. In this review, we will focus on common factors in OA and MetS, such as hypertension, obesity, dyslipidemia, mitochondrial dysfunction and hyperglycemia, linking one disease to the other. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Valproic acid alters the content and function of the cell-free DNA released by hepatocellular carcinoma (HepG2) cells in vitro.

    Science.gov (United States)

    Aucamp, Janine; Van Dyk, Hayley C; Bronkhorst, Abel J; Pretorius, Piet J

    2017-09-01

    It has long been believed that cell-free DNA (cfDNA) actively released into circulation can serve as intercellular messengers, and their involvement in processes such as the bystander effect strongly support this. However, this intercellular messaging function of cfDNA may have clinical implications that have not yet been considered. CfDNA was isolated from the growth medium of HepG2 cells treated with valproic acid (VPA). This cfDNA was then administered to untreated cells and cellular metabolic activity was measured. VPA altered the characteristics of cfDNA released by treated HepG2 cells in vitro. When administered to untreated cells, the cfDNA from cells treated with VPA resulted in the dose-dependent induction of glycolytic activity within 36 min of administration, but little to no alterations in oxidative phosphorylation. The glycolytic activity lasted for 4-6 h, whereas changes in subsequent cfDNA release and characteristics were found to remain persistent after two 24 h treatments. Fragmented genomic DNA from VPA-treated cells did not induce the effects observed for cfDNA obtained VPA-treated cells. It is possible for cfDNA to, under in vitro conditions, transfer pharmaceutically-induced effects to untreated recipient cells. Further investigation regarding this occurrence under in vivo conditions is, therefore, strongly encouraged. The intercellular messaging functions of cfDNA present in donated biological fluids has potential clinical implications that require urgent attention. These implications may, however, also have potential as new forms of treatment that can circumvent pharmacological barriers. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  17. Nitric oxide production by peritoneal macrophages from aged rats: A short term and direct modulation by citrulline.

    Science.gov (United States)

    Breuillard, Charlotte; Curis, Emmanuel; Le Plénier, Servane; Cynober, Luc; Moinard, Christophe

    2017-02-01

    Citrulline has anti-inflammatory properties and exerts beneficial effects on various impaired functions in aging. However, there are few data on citrulline action on immune function in aged populations. The objective of the study was to evaluate citrulline ability, after in vivo and in vitro administration, to modulate macrophage functions in aged rats and the possible pathways involved. Twenty-one-month-old Sprague-Dawley rats (n = 27) received a citrulline supplementation at 5 g/kg/d for 5 days, or an isonitrogenous diet, and peritoneal macrophages were cultured with or without LPS. In the in vitro study, macrophages from 22-month-old rats (n = 16) were cultured with or without LPS, citrulline and inhibitors of different inflammatory pathways (n = 8/conditions). Nitric oxide (NO) and tumor necrosis factor α (TNFα) production were measured in both in vivo and in vitro studies. Citrulline decreased NO production variability by peritoneal macrophages after in vivo administration (p = 0.0034) and downregulated NO production by 22% after in vitro administration (95% CI: [6%; 35%]; p = 0.0394), without any direct effect on TNFα production. None of the transductional pathways explored seem to be involved. Citrulline slightly modulates NO production in vivo and in vitro, suggesting a possible action through modulation of arginine metabolism in macrophages rather than a direct transductional effect. The pleiotropic effects of citrulline in aging could be due, at least in part, to the anti-inflammatory effect of citrulline. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  18. Genomic landscape of copy number variation and copy neutral loss of heterozygosity events in equine sarcoids reveals increased instability of the sarcoid genome.

    Science.gov (United States)

    Pawlina-Tyszko, Klaudia; Gurgul, Artur; Szmatoła, Tomasz; Ropka-Molik, Katarzyna; Semik-Gurgul, Ewelina; Klukowska-Rötzler, Jolanta; Koch, Christoph; Mählmann, Kathrin; Bugno-Poniewierska, Monika

    2017-09-01

    Although they are the most common neoplasms in equids, sarcoids are not fully characterized at the molecular level. Therefore, the objective of this study was to characterize the landscape of structural rearrangements, such as copy number variation (CNV) and copy neutral loss of heterozygosity (cnLOH), in the genomes of sarcoid tumor cells. This information will not only broaden our understanding of the characteristics of this genome but will also improve the general knowledge of this tumor and the mechanisms involved in its generation. To this end, Equine SNP64K Illumina microarrays were applied along with bioinformatics tools dedicated for signal intensity analysis. The analysis revealed increased instability of the genome of sarcoid cells compared with unaltered skin tissue samples, which was manifested by the prevalence of CNV and cnLOH events. Many of the identified CNVs overlapped with the other research results, but the simultaneously observed variability in the number and sizes of detected aberrations indicated a need for further studies and the development of more reliable bioinformatics algorithms. The functional analysis of genes co-localized with the identified aberrations revealed that these genes are engaged in vital cellular processes. In addition, a number of these genes directly contribute to neoplastic transformation. Furthermore, large numbers of cnLOH events identified in the sarcoids suggested that they may play no less significant roles than CNVs in the carcinogenesis of this tumor. Thus, our results indicate the importance of cnLOH and CNV in equine sarcoid oncogenesis and present a direction of future research. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  19. Helix 69 of Escherichia coli 23S ribosomal RNA as a peptide nucleic acid target.

    Science.gov (United States)

    Kulik, Marta; Markowska-Zagrajek, Agnieszka; Wojciechowska, Monika; Grzela, Renata; Wituła, Tomasz; Trylska, Joanna

    2017-07-01

    A fragment of 23S ribosomal RNA (nucleotides 1906-1924 in E. coli), termed Helix 69, forms a hairpin that is essential for ribosome function. Helix 69 forms a conformationally flexible inter-subunit connection with helix 44 of 16S ribosomal RNA, and the nucleotide A1913 of Helix 69 influences decoding accuracy. Nucleotides U1911 and U1917 are post-transcriptionally modified with pseudouridines (Ψ) and U1915 with 3-methyl-Ψ. We investigated Helix 69 as a target for a complementary synthetic oligonucleotide - peptide nucleic acid (PNA). We determined thermodynamic properties of Helix 69 and its complexes with PNA and tested the performance of PNA targeted at Helix 69 in inhibiting translation in cell-free extracts and growth of E. coli cells. First, we examined the interactions of a PNA oligomer complementary to the G1907-A1919 fragment of Helix 69 with the sequences corresponding to human and bacterial species (with or without pseudouridine modifications). PNA invades the Helix 69 hairpin creating stable complexes and PNA binding to the pseudouridylated bacterial sequence is stronger than to Helix 69 without any modifications. Second, we confirmed the binding of PNA to 23S rRNA and 70S ribosomes. Third, we verified the efficiency of translation inhibition of these PNA oligomers in the cell-free translation/transcription E. coli system, which were in a similar range as tetracycline. Next, we confirmed that PNA conjugated to the (KFF)3K transporter peptide inhibited E. coli growth in micromolar concentrations. Overall, targeting Helix 69 with PNA or other sequence-specific oligomers could be a promising way to inhibit bacterial translation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. The up regulation of phosphofructokinase1 (PFK1) protein during chemically induced hypoxia is mediated by the hypoxia-responsive internal ribosome entry site (IRES) element, present in its 5'untranslated region.

    Science.gov (United States)

    Ismail, Rehana; Ul Hussain, Mahboob

    2017-08-01

    Astrocytes cope-up the hypoxia conditions by up regulating the activity of the enzymes catalyzing the irreversible steps of the glycolytic pathway. The phosphofructokinase1 (PFK1), which converts fructose-6-phosphate to fructose-1, 6-bisphosphate, is the major regulatory enzyme of the glycolytic pathway. For this purpose, we investigated the expression regulation of the PFK1 during chemically induced hypoxia. After 48 h of the chemically induced hypoxia induction of the C6 glioma cells, the PFK1 protein depicted strong up regulation, with no appreciable change in its mRNA levels. The di-cistronic assay indicated the presence of a weak internal ribosome entry site (IRES) element in the 5'UTR of the PFK1 mRNA. Interestingly, the weak IRES element of the PFK1 was strongly up regulated after 48 h of the chemically induced hypoxia, indicative of a possible mechanism responsible for the induction of the PFK1 protein. The authenticity of the hypoxia-regulated IRES element of the PFK1, relative to the presence of the cryptic promoter element and/or the cryptic splicing was established using promoterless di-cistronic assay and the RT-PCR analysis. Moreover, the ectopic expression of the polypyrimidine tract binding (PTB) protein resulted in the enhanced activity of the IRES element of the PFK1. Additionally, it was established that the chemically induced hypoxia resulted in the increased shuttling of the PTB from the cell nucleus to the cytosol. The presence of a hypoxia responsive IRES element, in the 5'UTR of the PFK1 was established to be the possible mechanism responsible for the up regulation of the PFK1 protein. Our data provides an interesting mechanism that may explain the increased glycolytic capacity of the astrocytes after brain hypoxia. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Human placenta expresses both peripheral and neuronal isoform of tryptophan hydroxylase.

    Science.gov (United States)

    Laurent, Laetitia; Deroy, Kathy; St-Pierre, Joey; Côté, Francine; Sanderson, J Thomas; Vaillancourt, Cathy

    2017-09-01

    The role of placental serotonin has been an active topic of research notably because of its crucial role in brain development. However, which cell types synthesize serotonin in human placenta remains unknown. Moreover, it is not known if the two tryptophan hydroxylase isoforms (TPH1 and TPH2), the rate-limiting enzymes in serotonin biosynthesis, are expressed in placenta. Human placentas were obtained in first trimester or at term, and trophoblast cells were isolated and purified using a magnetic cell sorter and placed in primary culture. The tissue sublocalization of each TPH was determined by immunohistochemistry. TPH expression in primary villous trophoblasts was determined by PCR and immunoblotting, and serotonin secretion by LC-MS/MS. Villous cytotrophoblasts, syncytiotrophoblast, fetal capillaries, extravillous cytotrophoblasts, and decidual cells co-expressed TPH1 and TPH2. Moreover, mRNA and protein levels of both TPHs were detected in human primary trophoblast as well as in mouse placental tissues. Finally, human trophoblast cells were shown to produce serotonin de novo. This study demonstrates that both TPH1 and TPH2 are expressed in human and mouse placenta throughout pregnancy and helps to better understand the placental serotonin system, which is crucial for healthy pregnancy and fetal development. It is therefore important to further understand regulation of the placental serotonin system and how its disruption during pregnancy may impact the developing fetus and subsequent child programming. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  2. The M1 family of vertebrate aminopeptidases: role of evolutionarily conserved tyrosines in the enzymatic mechanism of aminopeptidase B.

    Science.gov (United States)

    Cadel, Sandrine; Darmon, Cécile; Pernier, Julien; Hervé, Guy; Foulon, Thierry

    2015-02-01

    Aminopeptidase B (Ap-B), a member of the M1 family of Zn(2+)-aminopeptidases, removes basic residues at the NH2-terminus of peptides and is involved in the in vivo proteolytic processing of miniglucagon and cholecystokinin-8. M1 enzymes hydrolyze numerous different peptides and are implicated in many physiological functions. As these enzymes have similar catalytic mechanisms, their respective substrate specificity and/or catalytic efficiency must be based on subtle structural differences at or near the catalytic site. This leads to the hypothesis that each primary structure contains a consensus structural template, strictly necessary for aminopeptidase activity, and a specific amino acid environment localized in or outside the catalytic pocket that finely tunes the substrate specificity and catalytic efficiency of each enzyme. A multiple sequence alignment of M1 peptidases from vertebrates allowed to identify conserved tyrosine amino acids, which are members of this catalytic backbone. In the present work, site-directed mutagenesis and 3D molecular modeling of Ap-B were used to specify the role of four fully (Y281, Y229, Y414, and Y441) and one partially (Y409) conserved residues. Tyrosine to phenylalanine mutations allowed confirming the influence of the hydroxyl groups on the enzyme activity. These groups are implicated in the reaction mechanism (Y414), in substrate specificity and/or catalytic efficiency (Y409), in stabilization of essential amino acids of the active site (Y229, Y409) and potentially in the maintenance of its structural integrity (Y281, Y441). The importance of hydrogen bonds is verified by the Y229H substitution, which preserves the enzyme activity. These data provide new insights into the catalytic mechanism of Ap-B in the M1 family of aminopeptidases. Copyright © 2015 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  3. The role of de novo protein synthesis and SIRT1 in ER stress-induced Atf4 and Chop mRNA expression in mammalian cells.

    Science.gov (United States)

    Chan, Stanley M H; Zhao, Xuechan; Elfowiris, Abdulsalam; Ratnam, Cherubina; Herbert, Terence P

    2017-07-01

    Endoplasmic reticulum (ER) stress and the activation of the unfolded protein response (UPR) have been implicated in the pathogenesis of many common human diseases. Integral to the UPR and an important determinant in cell fate is the expression of the pro-apoptotic transcription factor C/EBP homologous protein (CHOP). This is promoted by activating transcription factor 4 (ATF4) whose expression is rapidly up-regulated in response to ER stress through an eIF2α phosphorylation-dependent increase in protein synthesis. Our data demonstrates that this ER stress-induced increase in ATF4 and CHOP expression is initiated by an increase in Atf4 and Chop mRNA, which is also dependent upon eIF2α phosphorylation. Despite being dependent on eIF2α phosphorylation, we provide evidence that these increases in Atf4 and Chop mRNA expression may occur independently of de novo protein synthesis. Moreover, we show that ER stress-induced Chop mRNA expression is exacerbated by Sirtuin-1 (SIRT1) inhibition indicating that changes in the energy status of the cell may play an important role in its regulation. This work highlights and extends previous findings, and provides important new insights into the mechanism of ER stress-induced expression of Atf4 and Chop mRNA that clearly warrants further investigation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  4. Revisiting the metabolism and physiological functions of caprylic acid (C8:0) with special focus on ghrelin octanoylation.

    Science.gov (United States)

    Lemarié, Fanny; Beauchamp, Erwan; Legrand, Philippe; Rioux, Vincent

    2016-01-01

    Caprylic acid (octanoic acid, C8:0) belongs to the class of medium-chain saturated fatty acids (MCFAs). Dairy products and specific oils like coconut oil are natural sources of dietary C8:0 but higher intakes of this fatty acid can be provided with MCT (Medium-Chain Triglycerides) oil that consists in 75% of C8:0. MCFAs have physical and metabolic properties that are distinct from those of long-chain saturated fatty acids (LCFAs ≥ 12 carbons). Beneficial physiological effects of dietary C8:0 have been studied for a long time and MCT oil has been used as a special energy source for patients suffering from pancreatic insufficiency, impaired lymphatic chylomicron transport and fat malabsorption. More recently, caprylic acid was also shown to acylate ghrelin, the only known peptide hormone with an orexigenic effect. Through its covalent binding to the ghrelin peptide, caprylic acid exhibits an emerging and specific role in modulating physiological functions themselves regulated by octanoylated ghrelin. Dietary caprylic acid is therefore now suspected to provide the ghrelin O-acyltransferase (GOAT) enzyme with octanoyl-CoA co-substrates necessary for the acyl modification of ghrelin. This review tries to highlight the discrepancy between the formerly described beneficial effects of dietary MCFAs on body weight loss and the C8:0 newly reported effect on appetite stimulation via ghrelin octanoylation. The subsequent aim of this review is to demonstrate the relevance of carrying out further studies to better understand the physiological functions of this particular fatty acid. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  5. Structural and biochemical characterization of ligand recognition by CysB, the master regulator of sulfate metabolism.

    Science.gov (United States)

    Mittal, Monica; Singh, Appu Kumar; Kumaran, S

    2017-08-21

    CysB, a member of LysR-type transcriptional regulators, up-regulates the expression of genes associated with sulfate metabolism and cysteine biosynthesis. CysB is activated under sulfur limiting conditions by O-acetylserine (OAS) and N-acetylserine (NAS), but the activation mechanism of CysB remain unknown. Here, we report four crystal structures of ligand binding domains of CysB (CysB-LBD) in apo form and in complex with sulfate, OAS, and NAS. Our results show that CysB has two distinct allosteric ligand binding sites; a sulfate and NAS specific site-1 and a second, NAS and OAS specific site-2. All three ligands bind through the induced-fit mechanism. Surprisingly, OAS remodels the site-1 by binding to site-2, suggesting that site-1 and site-2 are coupled allosterically. Using DNA binding and site-directed mutagenesis approach, we show that OAS enhances NAS mediated activation and mutation at site-1 has no effect on site-2 mediated OAS activation. Results indicate that inducer binding triggered signals from OAS-Specific site-2 are relayed to DBD through site-1. Together, results presented here suggest that induced-fit binding and allosteric coupling between two ligand binding sites and DBD underlie the key feature of CysB activation. Further, this study provides first structural glimpse into recognition of inducer ligands by CysB and provides a general framework to understand how LTTR family regulators respond to dual activators. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. The Staphylococcus aureus FASII bypass escape route from FASII inhibitors.

    Science.gov (United States)

    Morvan, Claire; Halpern, David; Kénanian, Gérald; Pathania, Amit; Anba-Mondoloni, Jamila; Lamberet, Gilles; Gruss, Alexandra; Gloux, Karine

    2017-07-17

    Antimicrobials targeting the fatty acid synthesis (FASII) pathway are being developed as alternative treatments for bacterial infections. Emergence of resistance to FASII inhibitors was mainly considered as a consequence of mutations in the FASII target genes. However, an alternative and efficient anti-FASII resistance strategy, called here FASII bypass, was uncovered. Bacteria that bypass FASII incorporate exogenous fatty acids in membrane lipids, and thus dispense with the need for FASII. This strategy is used by numerous Gram-positive low GC % bacteria, including streptococci, enterococci, and staphylococci. Some bacteria repress FASII genes once fatty acids are available, and "constitutively" shift to FASII bypass. Others, such as the major pathogen Staphylococcus aureus, can undergo high frequency mutations that favor FASII bypass. This capacity is particularly relevant during infection, as the host supplies the fatty acids needed for bacteria to bypass FASII and thus become resistant to FASII inhibitors. Screenings for anti-FASII resistance in the presence of exogenous fatty acids confirmed that FASII bypass confers anti-FASII resistance among clinical and veterinary isolates. Polymorphisms in S. aureus FASII initiation enzymes favor FASII bypass, possibly by increasing availability of acyl-carrier protein, a required intermediate. Here we review FASII bypass and consequences in light of proposed uses of anti-FASII to treat infections, with a focus on FASII bypass in S. aureus. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  7. Folding of the silver aptamer in a DNAzyme probed by 2-aminopurine fluorescence.

    Science.gov (United States)

    Saran, Runjhun; Yao, Lu; Hoang, Peter; Liu, Juewen

    2017-07-12

    The RNA-cleaving Ag10c DNAzyme was recently isolated via in vitro selection and it can bind two Ag(+) ions for activity. The Ag10c contains a well-defined Ag(+) binding aptamer as indicated by DMS footprinting. Since aptamer binding is often accompanied with conformational changes, we herein used 2-aminopurine (2AP) to probe its folding in the presence of Ag(+). The Ag10c was respectively labeled with 2AP at three different positions, both in the substrate strand and in the enzyme strand, one at a time. Ag(+)-induced folding was observed at the substrate cleavage junction and the A9 position of the enzyme strand, consistent with aptamer binding. The measured Kd at the A9 position was 18 μM Ag(+) with a Hill coefficient of 2.17, similar to those obtained from the previous cleavage activity based assays. However, labeling a 2AP at the A2 position inhibited the activity and folding. Compared to other metal ions, Ag(+) has a unique sigmoidal folding profile indicative of multiple silver binding cooperatively. This suggests that Ag(+) can induce a local folding in the enzyme loop and this folding is important for activity. This study provides important biophysical insights into this new DNAzyme, suggesting the possibility of designing folding-based biosensors for Ag(+). Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Die wisselende rol van kontinuïteit en diskontinuïteit in die geskiedenis van die filosofie en die wiskunde

    Directory of Open Access Journals (Sweden)

    Danie F.M. Strauss

    2017-01-01

    Full Text Available Hierdie artikel wil lig werp op die onvermydelikheid van diskreetheid en kontinuïteit as primitiewe (ondefinieerbare verklaringswyses in die geskiedenis van die filosofie en die wiskunde. Dit beliggaam die algemene uitdaging om rekenskap van die samehang van iets wat uniek is te gee. Gödel beklemtoon die samehang van ‘primitiewe begrippe’. Die Griekse filosofie het reeds die ruimtelike geheel-dele-relasie – en die oneindige verdeelbaarheid daarvan – ontdek. Gedurende en na die Middeleeue het filosowe wipplank gery tussen ’n atomistiese waardering van die kontinuum en die teenoorgestelde daarvan, wat byvoorbeeld in die denke van Leibniz aangetref word as die gepostuleerde wet van kontinuïteit (lex continui. Die ontdekking van ‘inkommensurabiliteit’ (irrasionale getalle deur die Grieke het aanleiding gegee tot die eerste grondslagkrisis van die wiskunde en die geometrisering daarvan. Leibniz en Newton kon die probleme rondom die limietbegrip nie besleg nie en spoedig sou dit tot die derde grondslagkrisis van die wiskunde aanleiding gee. Dit het Frege en die ‘kontinuum-teoretici’ daartoe gebring om prioriteit aan die kontinuum te gee – diskreetheid is ’n katastrofe. Onlangs waardeer Smooth Infinitesimal Analysis kontinuïteit as iets wat ’n ‘ongebroke en ononderbroke geheel’ daarstel. Die intuïsionistiese wiskunde het opnuut aangesluit by die klem op die ruimtelike geheel-dele-relasie. Ondanks pogings om kontinuïteit eksklusief aritmeties en ruimtelik te verstaan bevestig die geskiedenis van die filosofie en die wiskunde onmiskenbaar dat die medekondisionerende rol van hierdie twee wyses van verklaring ’n konstante metgesel in die nadenke oor kontinuïteit en diskontinuïteit sou bly. (Die rol van kontinuïteit en diskontinuïteit in die fisika en biologie sal in ’n aparte artikel ondersoek word.

  9. Transcriptional regulation of the apolipoprotein F (ApoF) gene by ETS and C/EBPα in hepatoma cells.

    Science.gov (United States)

    Shen, Xue-Bin; Huang, Ling; Zhang, Shao-Hong; Wang, De-Ping; Wu, Yun-Li; Chen, Wan-Nan; Xu, Shang-Hua; Lin, Xu

    2015-05-01

    Apolipoprotein F (ApoF) inhibits cholesteryl ester transfer protein (CETP) activity and plays an important role in lipid metabolism. In the present study, the full-length human ApoF promoter was cloned, and the molecular mechanism of the regulation of ApoF was investigated. The ApoF promoter displayed higher activities in hepatoma cell lines, and the -198 nt to +79 nt promoter region contained the maximum promoter activity. In the promoter region of -198 nt to -2 nt there were four putative binding sites for transcription factors ETS-1/ETS-2 (named EBS-1 to EBS-4) and one for C/EBP. Mutation of EBS-2, EBS4 and the C/EBP binding site abolished the promoter activity, and ETS-1/ETS-2 and C/EBPα could interact with corresponding binding sites. In addition, overexpression of ETS-1/2 or C/EBPα enhanced, while dominant-negative mutants of ETS-1/2 and knockdown of C/EBPα decreased, ApoF promoter activities. ETS-1 and C/EBPα associated physically, and acted synergistically to activate ApoF transcription. These results demonstrated combined activation of the ApoF promoter by liver-enriched and ubiquitous transcription factors. Direct interactions between C/EBPα and ETS-1 were important for high liver-specific expression of ApoF. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Camelina sativa: An ideal platform for the metabolic engineering and field production of industrial lipids.

    Science.gov (United States)

    Bansal, Sunil; Durrett, Timothy P

    2016-01-01

    Triacylglycerols (TAG) containing modified fatty acids with functionality beyond those found in commercially grown oil seed crops can be used as feedstocks for biofuels and bio-based materials. Over the years, advances have been made in transgenically engineering the production of various modified fatty acids in the model plant Arabidopsis thaliana. However, the inability to produce large quantities of transgenic seed has limited the functional testing of the modified oil. In contrast, the emerging oil seed crop Camelina sativa possesses important agronomic traits that recommend it as an ideal production platform for biofuels and industrial feedstocks. Camelina possesses low water and fertilizer requirements and is capable of yields comparable to other oil seed crops, particularly under stress conditions. Importantly, its relatively short growing season enables it to be grown as part of a double cropping system. In addition to these valuable agronomic features, Camelina is amenable to rapid metabolic engineering. The development of a simple and effective transformation method, combined with the availability of abundant transcriptomic and genomic data, has allowed the generation of transgenic Camelina lines capable of synthesizing high levels of unusual lipids. In some cases these levels have surpassed what was achieved in Arabidopsis. Further, the ability to use Camelina as a crop production system has allowed for the large scale growth of transgenic oil seed crops, enabling subsequent physical property testing. The application of new techniques such as genome editing will further increase the suitability of Camelina as an ideal platform for the production of biofuels and bio-materials. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Global proteomic analysis of protein acetylation affecting metabolic regulation in Daphnia pulex.

    Science.gov (United States)

    Kwon, Oh Kwang; Sim, Juhee; Kim, Sun Ju; Oh, Hye Ryeung; Nam, Doo Hyun; Lee, Sangkyu

    2016-02-01

    Daphnia (Daphnia pulex) is a small planktonic crustacean and a key constituent of aquatic ecosystems. It is generally used as a model organism to study environmental toxic problems. In the past decade, genomic and proteomic datasets of Daphnia have been developed. The proteomic dataset allows for the investigation of toxicological effects in the context of "Daphnia proteomics," resulting in greater insights for toxicological research. To exploit Daphnia for ecotoxicological research, information on the post-translational modification (PTM) of proteins is necessary, as this is a critical regulator of biological processes. Acetylation of lysine (Kac) is a reversible and highly regulated PTM that is associated with diverse biological functions. However, a comprehensive description of Kac in Daphnia is not yet available. To understand the cellular distribution of lysine acetylation in Daphnia, we identified 98 acetylation sites in 65 proteins by immunoprecipitation using an anti-acetyllysine antibody and a liquid chromatography system supported by mass spectroscopy. We identified 28 acetylated sites related to metabolic proteins and six acetylated enzymes associated with the TCA cycle in Daphnia. From GO and KEGG enrichment analyses, we showed that Kac in D. pulex is highly enriched in proteins associated with metabolic processes. Our data provide the first global analysis of Kac in D. pulex and is an important resource for the functional analysis of Kac in this organism. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  12. Les apports possibles de la phraséologie à la didactique des langues étrangères

    Directory of Open Access Journals (Sweden)

    Mojca Pecman

    2005-12-01

    Full Text Available L'article explore les avantages d'une analyse phraséologique du discours scientifique face aux difficultés de la maîtrise des formules conventionnelles de ce genre dans une langue étrangère, en l'occurrence en anglais. Notre recherche postule en effet l'existence d'une langue commune aux scientifiques, une langue qui transcende les disciplines, et désormais, grâce à l'anglais, les continents. Pour observer les caractéristiques de cette Langue Scientifique Générale un corpus parallèle a été mis en place recueillant des textes de trois domaines connexes : la chimie, la physique et la biologie. Le dépouillement de ce corpus a abouti à une base de données phraséologiques dont les principes qui ont guidé la construction assurent sa réutilisabilité, notamment pour la réalisation d'applications concrètes à destination des apprenants. L'article présente un projet de construction d'un dictionnaire phraséologique multifonction offrant un double accès aux unités phraséologiques (UP, un accès via la forme des UP (fondé sur une approche sémasiologique de la langue et un accès via le sens des UP (fondé sur une approche onomasiologique de la langue.

  13. Contre l’esprit.

    Directory of Open Access Journals (Sweden)

    Bernard Andrieu

    2004-04-01

    Full Text Available Notre recherche consiste à retrouver, sous la partie visible des sciences cognitives, la partie invisible toujours active qui les fonde c'est-à-dire les nœuds liant à propos du cerveau-corps-esprit la médecine, la psychologie, la philosophie et la psychiatrie. Une certaine histoire philosophique de la psychologie voudrait imposer la thèse d'une indépendance de l'esprit par rapport au corps comme de la psychologie par rapport à la physiologie, la biologie, la neurologie ou encore la génétique. Pourtant l’étude des troubles neurologiques, des neuropathies du développement des cerveaux de l’enfant prématuré, des psychopathologies des affects et des lésions, dont le XIXe siècle avait constitué ces modèles, se poursuivent aujourd’hui pour maintenir l’interrogation sur la relation esprit-cerveau-corps.Our research consists in finding, beneath the visible part of cognitive sciences, the always active invisible part which founds them, that is to say the knots about the brain-body-mind linking medicine, psychology, philosophy and psychiatry together. Some philosophical history of psychology tries to impose the thesis of an independence of the mind from the body as well as of psychology from physiology, biology, neurology or genetics. Yet, the study of neurological troubles, of neuropathies of the development of the premature child's brain, of psychopathies of affects and lesions, from which the XIXth century had constituted models, is still going on today, to keep questioning about the relation mind-brain-body.

  14. Pilot in vivo toxicological investigation of boron nitride nanotubes

    Directory of Open Access Journals (Sweden)

    Ciofani G

    2012-01-01

    Full Text Available Gianni Ciofani1, Serena Danti2, Giada Graziana Genchi1,3, Delfo D'Alessandro2, Jean-Luc Pellequer4, Michaël Odorico4, Virgilio Mattoli1, Mario Giorgi51Italian Institute of Technology, Center of MicroBioRobotics co Scuola Superiore Sant'Anna, 2Department of Neuroscience, University of Pisa, 3The BioRobotics Institute, Scuola Superiore Sant'Anna, Pisa, Italy; 4Commissariat à l'Energie Atomique, Institut de Biologie Environnementale et Biotechnologie, Department of Biochemistry and Nuclear Toxicology, Bagnols-sur-Cèze, France; 5Division of Pharmacology and Toxicology, Veterinary Clinics Department, University of Pisa, Pisa, ItalyAbstract: Boron nitride nanotubes (BNNTs have attracted huge attention in many different research fields thanks to their outstanding chemical and physical properties. During recent years, our group has pioneered the use of BNNTs for biomedical applications, first of all assessing their in vitro cytocompatibility on many different cell lines. At this point, in vivo investigations are necessary before proceeding toward realistic developments of the proposed applications. In this communication, we report a pilot toxicological study of BNNTs in rabbits. Animals were injected with a 1 mg/kg BNNT solution and blood tests were performed up to 72 hours after injection. The analyses aimed at evaluating any acute alteration of hematic parameters that could represent evidence of functional impairment in blood, liver, and kidneys. Even if preliminary, the data are highly promising, as they showed no adverse effects on all the evaluated parameters, and therefore suggest the possibility of the realistic application of BNNTs in the biomedical field.Keywords: boron nitride nanotubes, in vivo testing, toxicology

  15. The role and regulation of the peroxisome proliferator activated receptor alpha in human liver.

    Science.gov (United States)

    Kersten, Sander; Stienstra, Rinke

    2017-05-01

    The peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor that is abundantly expressed in liver. PPARα is activated by fatty acids and various other lipid species, as well as by a class of chemicals referred to as peroxisome proliferators. Studies in mice have shown that PPARα serves as the master regulator of hepatic lipid metabolism during fasting. In addition, PPARα suppresses inflammation and the acute phase response. Comparatively little is known about PPARα in human liver. Here, an overview is provided of the role and regulation of PPARα in human liver. The main outcomes are: 1) the level of PPARA mRNA expression in human and mouse liver is similar. 2) Expression of PPARA in human liver is reduced in patients with non-alcoholic steatohepatitis or infected with the hepatitis C virus. 3) PPARα in human liver is able to effectively induce the expression of numerous genes involved in numerous lipid metabolic pathways, including microsomal, peroxisomal and mitochondrial fatty acid oxidation, fatty acid binding and activation, fatty acid elongation and desaturation, synthesis and breakdown of triglycerides and lipid droplets, lipoprotein metabolism, gluconeogenesis, bile acid metabolism, and various other metabolic pathways and genes. 4) PPARα activation in human liver causes the down-regulation of a large number of genes involved in various immunity-related pathways. 5) Peroxisome proliferators do not promote tumour formation in human liver as opposed to mouse liver because of structural and functional differences between human and mouse PPARα. 6) In addition to helping to correct dyslipidemia, PPARα agonists may hold promise as a therapy for patients with cholestatic liver diseases, non-alcoholic fatty liver disease, and/or type 2 diabetes. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Beneficial effects of tigerinin-1R on glucose homeostasis and beta cell function in mice with diet-induced obesity-diabetes.

    Science.gov (United States)

    Ojo, Opeolu O; Srinivasan, Dinesh K; Owolabi, Bosede O; Flatt, Peter R; Abdel-Wahab, Yasser H A

    2015-02-01

    This paper investigates the anti-diabetic effects of tigerinin-1R (RVCSAIPLPICH.NH2), a previously described amphibian host defence peptide, in mice with diet-induced obesity-diabetes. Proteolytic degradation of synthetic tigerinin-1R was investigated by reversed-phase HPLC and MALDI-TOF mass spectrometry. Changes in glycaemic responses and metabolic parameters were measured in mice with high fat diet-induced obesity-diabetes treated with twice-daily with of tigerinin-1R (75 nmol/kg bw) for 15 days. Indirect calorimetry and body composition were measured by CLAMS and DEXA whole body scanning. Insulin secretory responses of islets isolated from treated and untreated mice were examined. Tigerinin-1R was resistant to in vitro degradation by plasma enzymes. Twice-daily injection of tigerinin-1R for 15 days had no significant effect on food intake or body weight. Non-fasting glucose levels were significantly lowered, and insulin levels were elevated compared to saline treated controls. Glycaemic responses to both oral and intraperitoneal glucose administration were significantly improved by tigerinin-1R treatment. Plasma insulin was also significantly elevated. The peptide had no significant effect on insulin sensitivity but the beta cell responses of islets isolated from treated mice to a range of nutrients and peptidergic secretagogues were significantly improved. Oxygen consumption, CO2 production, respiratory exchange ratio, energy expenditure and body composition were not significantly altered by treatment with tigerinin-1R. Tigerinin-1R significantly improves glucose homeostasis and may have potential as a novel antidiabetic agent. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  17. Contribution to the studies on the mineral content of plant material through radioactivation analysis; Contribution a l'etude de la composition minerale des matieres vegetales au moyen de l'analyse par radioactivation

    Energy Technology Data Exchange (ETDEWEB)

    Fourcy, A. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1968-03-15

    Radioactivation analysis is by its great sensibility or its rapidity quite helpful in plant biology and agronomy. Specific composition of plants and results to obtain in biological experimentation have needed a practical research on analytical methods for plant materials, using for radioactivation swimming-pool reactor neutrons and 14 MeV neutrons from a generator. Dosage process for 25 elements is exposed, taking account of the interest of the analysis for each element, the average amount occurring in plants and the result obtained. Many applications are developed, concerning nutrition physiology, genetics, parasitology, toxicology, control of manufactured agricultural and pharmaceutical products industrial and pesticides residues, ecology, radioecology and biochemistry. (author) [French] L'analyse par radioactivation, par sa grande sensibilite ou sa rapidite, est susceptible de rendre de nombreux services en biologie vegetale et en agronomie. La composition particuliere des plantes et les buts recherches dans l'experimentation ont exige une etude concrete des methodes d'analyse propres a la matiere vegetale en utilisant, pour la radioactivation, soit un reacteur de type piscine a eau legere, soit un accelerateur generateur de neutrons de 14 MeV. Le mode de dosage de 25 elements est expose en tenant compte de l'interet de l'analyse de chaque element, des teneurs moyennes rencontrees dans les plantes, et du resultat atteint. De nombreuses applications sont developpees qui touchent a la physiologie de la nutrition, la genetique, la parasitologie, la toxicologie, le controle des fabrications, les pollutions industrielles, l'ecologie, la radioecologie et la biochimie. (auteur)

  18. De l’hybridation féconde

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    Milagros Ezquerro

    2010-07-01

    Full Text Available Ce travail présente tout d’abord la démarche méthodologique et théorique qui a conduit son auteur à s’inspirer de la pensée scientifique en général, et à emprunter certaines notions au domaine de la physique, des sciences de l’information, de la biologie, etc, afin de renouveler la théorie des textes. Les notions de « complexité » et de « système complexe ouvert et auto-organisateur », l’importance et la fonction de « l’observation », la notion de « vide » sont donnés comme exemples d’une hybridation féconde entre la pensée théorique en analyse des textes et les concepts utilisés dans divers champs scientifiques.Este trabajo presenta primero el camino metodológico y teórico que llevó a su autor a inspirarse en el pensamiento científico en general, y a apropiarse de ciertas nociones de los campos de la física, de las ciencias de la información, de la biología, etc., con la finalidad de renovar la teoría del texto. Las nociones de « complejidad » y de « sistema complejo abierto y auto organizador », la importancia y la función de la « observación », la noción de « vacío » son ejemplos de una hibridación fecunda entre el pensamiento teórico en análisis textual y los conceptos utilizados en diversos campos científicos.

  19. NKCC2 activity is inhibited by the Bartter's syndrome type 5 gain-of-function CaR-A843E mutant in renal cells.

    Science.gov (United States)

    Carmosino, Monica; Gerbino, Andrea; Hendy, Geoffrey N; Torretta, Silvia; Rizzo, Federica; Debellis, Lucantonio; Procino, Giuseppe; Svelto, Maria

    2015-04-01

    The gain-of-function A843E mutation of the calcium sensing receptor (CaR) causes Bartter syndrome type 5. Patients carrying this CaR variant show a remarkably reduced renal NaCl reabsorption in the thick ascending limb (TAL) of Henle's loop resulting in renal loss of NaCl in the absence of mutations in renal Na(+) and Cl(-) ion transporters. The molecular mechanisms underlying this clinical phenotype are incompletely understood. We investigated, in human embryonic kidney 293 (HEK 293) cells and porcine kidney epithelial (LLC-PK1) cells, the functional cross-talk of CaR-A843E with the Na(+):K(+):2Cl(-) co-transporter, NKCC2, which provides NaCl reabsorption in the TAL. The expression of the CaR mutant did not alter the apical localisation of NKCC2 in LLC-PK1 cells. However, the steady-state NKCC2 phosphorylation and activity were decreased in cells transfected with CaR-A843E compared with the control wild-type CaR (CaR WT)-transfected cells. Of note, low-Cl(-)-dependent NKCC2 activation was also strongly inhibited upon the expression of CaR-A843E mutant. The use of either P450 ω-hydroxylase (CYP4)- or phospholipase A2 (PLA2)-blockers suggests that this effect is likely mediated by arachidonic acid (AA) metabolites. The data suggested that the activated CaR affects intracellular pathways modulating NKCC2 activity rather than NKCC2 intracellular trafficking in renal cells, and throw further light on the pathological role played by active CaR mutants in Bartter syndrome type 5. © 2015 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  20. Babinski, histologist and anatomo-pathologist.

    Science.gov (United States)

    Poirier, J

    2008-01-01

    Joseph Babinski (1857-1932), a French neurologist of Polish origin, médecin des hôpitaux de Paris, is well known for the discovery of the Sign (the toes phenomenon) which bears his name. Beyond the Sign, his semiological work in the field of neurology is also important (particularly cutaneous and osteo-tendinous reflexes, cerebellar and vestibular semiology, hysteria and pithiatism) as well as his role in the birth of the French neurosurgery. On the contrary, the implication of Babinski in pathological anatomy and histology is usually unrecognized. However, in the beginning of his career, Babinski worked as an Interne in the clinical departments of Victor Cornil (1837-1908), professor of pathological anatomy and president of the Société d'Anatomie de Paris, Alfred Vulpian (1826-1887), past professor of pathological anatomy and then professor of experimental physiology, and in the laboratory of Louis Ranvier (1835-1922), professor of general anatomy at the Collège de France. Babinski beacame préparateur at the chair of pathological anatomy, member then treasurer of the Société Anatomique, member of the Société de Biologie. He reported on several clinico-pathological observations of general pathology (liver cirrhosis, cancer of the kidney, cancer of a buttock, squamous epithelioma, tuberculosis, multiple cysts of the liver and the kidneys, bowel occlusion), of neuropathology (embolic brain softenings, hydatic cysts of the brain, multiple sclerosis, spinal cord combined sclerosis, tabetic arthropathies, adiposo-genital syndrome due to a pituitary tumor) and of human neuro-muscular histology (neuro-muscular spindles, muscular histology after nerve sectioning, diphtheria paralysis, peripheral neuritis).

  1. Revelation of fibroblast protein commonalities and differences and their possible roles in wound healing and tumourigenesis using co-culture models of cells.

    Science.gov (United States)

    Jarkovska, Karla; Dvorankova, Barbora; Halada, Petr; Kodet, Ondrej; Szabo, Pavol; Gadher, Suresh Jivan; Motlik, Jan; Kovarova, Hana; Smetana, Karel

    2014-07-01

    The in vitro co-culture models of communication between normal fibroblasts and epithelial cells, such as keratinocytes or squamous cell carcinoma cells of FaDu line representing wound healing or cancer development, were established by non-direct contact between the cells and utilised in this study to examine epithelia-induced changes in overall fibroblast proteome patterns. We were able to select the proteins co-regulated in both models in order to evaluate possible molecular commonalities between wound healing and tumour development. Amongst the most pronounced were the proteins implemented in contractile activity and formation of actin cytoskeleton such as caldesmon, calponin-2, myosin regulatory light-chain 12A and cofilin-1, which were expressed independently of the presence of α-smooth muscle actin. Additionally, proteins altered differently highlighted functional and cellular phenotypes during transition of fibroblasts towards myofibroblasts or cancer-associated fibroblasts. Results showed coordinated regulation of cytoskeleton proteins selective for wound healing which were lost in tumourigenesis model. Vimentin bridged this group of proteins with other regulated proteins in human fibroblasts involved in protein or RNA processing and metabolic regulation. The findings provide strong support for crucial role of stromal microenvironment in wound healing and tumourigenesis. In particular, epithelia-induced protein changes in fibroblasts offer new potential targets which may lead to novel tailored cancer therapeutic strategies. © 2014 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  2. Kinetic characterization, optimum conditions for catalysis and substrate preference of secretory phospholipase A2 from Glycine max in model membrane systems.

    Science.gov (United States)

    Mariani, María Elisa; Madoery, Ricardo Román; Fidelio, Gerardo Daniel

    2015-01-01

    Two secretory phospholipase A2 (sPLA2s) from Glycine max, GmsPLA2-IXA-1 and GmsPLA2-XIB-2, have been purified as recombinant proteins and the activity was evaluated in order to obtain the optimum conditions for catalysis using mixed micelles and lipid monolayers as substrate. Both sPLA2s showed a maximum enzyme activity at pH 7 and a requirement of Ca(2+) in the micromolar range. These parameters were similar to those found for animal sPLA2s but a surprising optimum temperature for catalysis at 60 °C was observed. The effect of negative interfacial charges on the hydrolysis of organized substrates was evaluated through initial rate measurements using short chain phospholipids with different head groups. The enzymes showed subtle differences in the specificity for phospholipids with different head groups (DLPC, DLPG, DLPE, DLPA) in presence or absence of NaCl. Both recombinant enzymes showed lower activity toward anionic phospholipids and a preference for the zwitterionic ones. The values of the apparent kinetic parameters (Vmax and KM) demonstrated that these enzymes have more affinity for phosphatidylcholine compared with phosphatidylglycerol, in contrast with the results observed for pancreatic sPLA2. A hopping mode of catalysis was proposed for the action of these sPLA2 on mixed phospholipid/triton micelles. On the other hand, Langmuir-monolayers assays indicated an optimum lateral surface pressure for activity in between 13 and 16 mN/m for both recombinant enzymes. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  3. Specificity characterization of the α-mating factor hormone by Kex2 protease.

    Science.gov (United States)

    Manfredi, Marcella Araújo; Antunes, Alyne Alexandrino; Jesus, Larissa de Oliveira Passos; Juliano, Maria Aparecida; Juliano, Luiz; Judice, Wagner Alves de Souza

    2016-12-01

    Kex2 is a Ca(2+)-dependent serine protease from S. cerevisiae. Characterization of the substrate specificity of Kex2 is of particular interest because this protease serves as the prototype of a large family of eukaryotic subtilisin-related proprotein-processing proteases that cleave sites consisting of pairs or clusters of basic residues. Our goal was to study the prime region subsite S' of Kex2 because previous studies have only taken into account non-prime sites using AMC substrates but not the specificity of prime sites identified through structural modeling or predicted cleavage sites. Therefore, we used peptides derived from Abz-KR↓EADQ-EDDnp and Abz-YKR↓EADQ-EDDnp based on the pro-α-mating factor sequence. The specificity of Kex2 due to basic residues at P1' is affected by the type of residue in the P3 position. Some residues in P1' with large or bulky side chains yielded poor substrate specificity. The kcat/KM values for peptides with P2' substitutions containing Tyr in P3 were higher than those obtained for the peptides without Tyr. In fact, P' and P modifications mainly promoted changes in kcat and KM, respectively. The pH profile of Kex2 was fit to a double-sigmoidal pH-titration curve. The specificity results suggest that Kex2 might be involved in the processing of the putative cleavage sites in a polypeptide involved in cell elongation, hyphal formation and the processing of a toxin, which result in host cell lysis. In summary, the specificity of Kex2 is dependent on the set of interactions with prime and non-prime subsites, resulting in synergism. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  4. Plasma kallikrein enhances platelet aggregation response by subthreshold doses of ADP.

    Science.gov (United States)

    Ottaiano, Tatiana F; Andrade, Sheila S; de Oliveira, Cleide; Silva, Mariana C C; Buri, Marcus V; Juliano, Maria A; Girão, Manoel J B C; Sampaio, Misako U; Schmaier, Alvin H; Wlodawer, Alexander; Maffei, Francisco H A; Oliva, Maria Luiza V

    2017-04-01

    Human plasma kallikrein (huPK) potentiates platelet responses to subthreshold doses of ADP, although huPK itself, does not induce platelet aggregation. In the present investigation, we observe that huPK pretreatment of platelets potentiates ADP-induced platelet activation by prior proteolysis of the G-protein-coupled receptor PAR-1. The potentiation of ADP-induced platelet activation by huPK is mediated by the integrin αIIbβ3 through interactions with the KGD/KGE sequence motif in huPK. Integrin αIIbβ3 is a cofactor for huPK binding to platelets to support PAR-1 hydrolysis that contributes to activation of the ADP signaling pathway. This activation pathway leads to phosphorylation of Src, AktS(473), ERK1/2, and p38 MAPK, and to Ca(2+) release. The effect of huPK is blocked by specific antagonists of PAR-1 (SCH 19197) and αIIbβ3 (abciximab) and by synthetic peptides comprising the KGD and KGE sequence motifs of huPK. Further, recombinant plasma kallikrein inhibitor, rBbKI, also blocks this entire mechanism. These results suggest a new function for huPK. Formation of plasma kallikrein lowers the threshold for ADP-induced platelet activation. The present observations are consistent with the notion that plasma kallikrein promotes vascular disease and thrombosis in the intravascular compartment and its inhibition may ameliorate cardiovascular disease and thrombosis. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  5. La téléologie critique et ses paradigmes scientifiques. Sur la méthode de l’Histoire selon Kant

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    Gérard Raulet

    2015-06-01

    Full Text Available Les textes de Kant sur l’histoire sont souvent traités comme secondaires par les philosophes qui travaillent sur les systèmes de pensée, tandis que certains interprètes les qualifient de « quatrième critique ». La thèse défendue ici est que l’intervention de la critique kantienne dans le champ des pratiques et des réflexions historiques constitue un tournant décisif. Au moment où l’idée de progrès s’affirme contre les deux paradigmes dominants de l’histoire locale et de la théodicée chrétienne, était nécessaire un traitement critique de la notion même de progrès qui soit à la hauteur du défi scientifique : établir la légitimité d’une science historique, pour autant qu’elle soit possible. Trois modèles de sciences constituent l’horizon de scientificité que l’histoire doit viser même si elle ne doit jamais l’atteindre : l’astronomie, la physique et la biologie. La téléologie est au cœur de cette entreprise, elle en est l’instrument. Elle est au cœur de l’entreprise parce qu’elle est par ailleurs aussi la science de la vie interne des organismes. C’est donc à partir de la téléologie, de l’opposition entre son usage « dogmatique » dans les sciences naturelles, « critique » dans la science historique, que nous entreprenons ici de cerner la question de la « science de l’histoire » chez Kant.

  6. Chronomics, human time estimation, and aging

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    Franz Halberg

    2008-12-01

    Full Text Available Franz Halberg, Robert B Sothern, Germaine Cornélissen, Jerzy Czaplicki1Halberg Chronobiology Center, University of Minnesota, Minneapolis, MN, USA; 1Institut de Pharmacologie et de Biologie Structurale CNRS, Université Paul Sabatier, Toulouse, FranceBackground: Circadian rhythm stage affects many outcomes, including those of mental aging.Methods: Estimations of 1 minute ∼5 times/day for a year, 25 years apart, by a healthy male biomedical scientist (RBS, are analyzed by the extended cosinor.Results: Cycles of a half-week, a week, ∼30 days, a half-year and a year, in self-assessed 1-minute estimation by RBS between 25 and 60 years of age in health, are mapped for the first time, compared and opposite effects are found. For RBS at 60 vs at 25 years of age, it takes less time in the morning around 10:30 (P < 0.001, but not in the evening around 19:30 (P = 0.956, to estimate 1 minute.Discussion: During the intervening decades, the time of estimating 1 minute differed greatly, dependent on circadian stage, being a linear decrease in the morning and increase in the evening, the latter modulated by a ∼33.6-year cycle.Conclusion: Circadian and infradian rhythm mapping is essential for a scrutiny of effects of aging. A ∼30-day and a circannual component apparent at 25 years of age are not found later; cycles longer than a year are detected. Rhythm stages await tests as markers for timing therapy in disease.Keywords: circadian rhythm, mental function, time estimation

  7. Gaseous ligand selectivity of the H-NOX sensor protein from Shewanella oneidensis and comparison to those of other bacterial H-NOXs and soluble guanylyl cyclase.

    Science.gov (United States)

    Wu, Gang; Liu, Wen; Berka, Vladimir; Tsai, Ah-Lim

    2017-09-01

    To delineate the commonalities and differences in gaseous ligand discrimination among the heme-based sensors with Heme Nitric oxide/OXygen binding protein (H-NOX) scaffold, the binding kinetic parameters for gaseous ligands NO, CO, and O2, including KD, kon, and koff, of Shewanella oneidensis H-NOX (So H-NOX) were characterized in detail in this study and compared to those of previously characterized H-NOXs from Clostridium botulinum (Cb H-NOX), Nostoc sp. (Ns H-NOX), Thermoanaerobacter tengcongensis (Tt H-NOX), Vibrio cholera (Vc H-NOX), and human soluble guanylyl cyclase (sGC), an H-NOX analogue. The KD(NO) and KD(CO) of each bacterial H-NOX or sGC follow the "sliding scale rule"; the affinities of the bacterial H-NOXs for NO and CO vary in a small range but stronger than those of sGC by at least two orders of magnitude. On the other hand, each bacterial H-NOX exhibits different characters in the stability of its 6c NO complex, reactivity with secondary NO, stability of oxyferrous heme and autoxidation to ferric heme. A facile access channel for gaseous ligands is also identified, implying that ligand access has only minimal effect on gaseous ligand selectivity of H-NOXs or sGC. This comparative study of the binding parameters of the bacterial H-NOXs and sGC provides a basis to guide future new structural and functional studies of each specific heme sensor with the H-NOX protein fold. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Ein Mythos wird besichtigt. Le deuxième sexe von Simone de Beauvoir unter dem Mikroskop der Genderforschung A Myth is Probed: Simone de Beauvoir’s Le deuxième sexe Under the Microscope of Gender Research

    Directory of Open Access Journals (Sweden)

    Lieselotte Steinbrügge

    2005-11-01

    Full Text Available Aus Anlass des 50jährigen Jubiläums der Erstausgabe von Das andere Geschlecht haben namhafte Wissenschaftlerinnen aus den Gebieten Philosophie, Biologie, Soziologie, Psychoanalyse, Geschichte und Literatur das fast tausendseitige Standardwerk des Feminismus einer akribischen Lektüre unterzogen und dabei versucht, jene Fragen zu rekonstruieren, auf die das Werk bei seinem Erscheinen im Jahr 1949 eine Antwort gab. Die zeitlos scheinende Formel von der Konstruiertheit weiblicher Identität sollte wieder in ihren ursprünglichen Entstehungszusammenhang gestellt, die Autorin aus der mythischen Ferne in die kritische Nähe gerückt werden. Diese kritischen Lektüren sind insgesamt gut dokumentiert und erlauben meines Wissens zum ersten Mal einen Einblick in die Beauvoirsche Werkstatt. Ein weiterer – ebenfalls von Ingrid Galster herausgegebener – Band dokumentiert die Reaktionen, die unmittelbar nach Erscheinen von Le deuxième sexe in der französischen Presse erschienen sind.In celebration of the 50-year anniversary of the first edition of The Second Sex, well-known scholars from the fields of philosophy, biology, sociology, psychoanalysis, history, and literature have meticulously read the almost one-thousand-page standard work of feminism. In doing so, they have attempted to reconstruct those questions to which the work provided an answer at the time of its publication in the year 1949. The seemingly timeless formula of the constructed nature of feminine identity is placed in its original context and the author brought from the mythological distance to close critical proximity. These critical readings are overall well documented and allow a first glimpse, to my knowledge, into de Beauvoir’s workshop. A second volume—also edited by Ingrid Galster—documents the reactions that appeared in the French press at the time of the first publication of The Second Sex.

  9. Construire une conception scientifique du vivant avec des élèves de 5-7 ans : approche didactique pour mieux comprendre les processus d’apprentissage et les enjeux développementaux

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    Grancher Céline

    2015-01-01

    Full Text Available Cet article s’intéresse au vivant en tant qu’objet de savoir et aux phénomènes d’enseignement-apprentissage de ce concept au début de l’école primaire en France (élèves de 5-7 ans, classes de CP-CE1. Nous nous interrogeons sur les contenus à enseigner et les situations possibles à mettre en oeuvre dans les classes pour que des élèves construisent une conception scientifique du vivant. Nous délimitons d’abord le concept de vivant dans une perspective d’enseignement à de jeunes élèves. Puis nous identifions un des enjeux de l’enseignement-apprentissage du vivant : permettre aux élèves de construire un autre rapport au vivant que celui de la vie de tous les jours. Nous abordons les situations scolaires comme des processus d’acculturation scientifique scolaire. Les élèves sont en effet incités à entrer dans une culture scientifique en s’appropriant à la fois des savoirs relatifs au vivant et des pratiques de la biologie. À partir de deux séquences d’enseignement réalisées en CP puis en CE1 avec les mêmes élèves, nous repérons des indicateurs qui témoignent de la construction d’une conception scientifique du vivant par les élèves. Nous montrons également que les processus d’acculturation scientifique dans lesquels les élèves sont engagés ont des effets sur leur développement.

  10. « Vie » et « vivant » : perspectives épistémologiques

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    dell’Angelo-Sauvage Michèle

    2015-01-01

    Full Text Available Des idées des philosophes de la Grèce ancienne, à celles que suggèrent les avancées contemporaines de la biologie, différentes conceptions de la vie et du vivant sont proposées sans qu’un consensus ne soit obtenu. Différents auteurs ont présenté la vie comme l’affaire des philosophes, sous ses aspects politiques et sociaux, tandis que le vivant était l’affaire des biologistes préoccupés du fonctionnement des organismes (Canguilhem, 1990; Fassin, 2000; Jacob, 1970; Pichot, 2011. Mais cette distinction est actuellement rediscutée (Cherlonneix, 2013; Morange, 2013. D’autres auteurs mettent en contraste les approches réductionnistes et holistes et présentent les conséquences de ces points de vue. Dès 2006, Guespin-Michel et Stewart envisageaient un changement de paradigme inévitable face aux modifications de méthodes dans différents groupes de recherche. Nous proposons de porter un regard croisé sur les concepts de vie et de vivant dans le but d’éclaircir les fondements épistémologiques sous-jacents à un enseignement relatif au vivant : observe-t-on une influence réciproque des conceptions de « vie » et de « vivant » dans les différents courants de pensée ? Les changements épistémologiques liés aux observations faites à différentes échelles biologiques modifient-ils les réflexions philosophiques, scientifiques et sociétales ? Qu’en est-il actuellement de la distinction vie/vivant ?

  11. Présentation

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    Leger Claude-Louis

    2000-05-01

    Full Text Available Ce qui frappe aujourd’hui, c’est une évolution rapide des connaissances sur les quatre vitamines liposolubles qui font l’objet des revues générales présentées dans ce dossier, et plus particulièrement peut-être sur les vitamines A, D et E. On savait ces vitamines indispensables en raison de leur implication dans les réactions cellulaires, pas uniquement métaboliques d’ailleurs, mais on ne pouvait les soupçonner d’intervenir dans des phénomènes complexes touchant aux régulations cellulaires et à l’expression des gènes avant l’explosion des techniques de biologie moléculaire. Ces trois vitamines ont ainsi, entre autres, la capacité de réguler la prolifération et la différenciation cellulaire selon des mécanismes qui peuvent paraître différents aujourd’hui dans certains cas (pour la vitamine E par exemple, ou souvent proches (cas des vitamine A et D. Les quatre vitamines sont capables en revanche d’intervenir dans la mort cellulaire programmée (apoptose. Dans le cas du tissu osseux, ce sont les vitamines A, D et K qui agissent sur l’accrétion calcique. La vitamine E, quant à elle, pourrait prévenir, au moins théoriquement, l’ostéoporose.

  12. The Biodemography of Fertility: A Review and Future Research Frontiers.

    Science.gov (United States)

    Mills, Melinda C; Tropf, Felix C

    In sozialwissenschaftlichen Untersuchungen von Fertilitätsentscheidungen und –verhalten sind biodemographische Ansätze bislang kaum integriert worden, was zu überwiegend sozial-deterministischen Theorien und Befunden geführt hat. Der vorliegende Beitrag diskutiert zunächst die Gründe für diese weitgehend fehlende Integration, gibt dann einen Überblick über frühere Untersuchungen, fasst die bisher vorliegenden Erkenntnisse zusammen und zeigt schließlich Perspektiven zukünftiger Forschung auf. Ausgehend von grundlegenden Arbeiten zu den proximalen Determinanten der Fertilität werden verhaltensgenetische (Familien- und Zwillings-)Studien besprochen, die das Ausmaß genetischer Einflüsse auf Fertilitätsmerkmale isolieren konnten. Anschließend wird die Forschung zur Gen-Umwelt-Interaktion, zur Bedeutung von kohorten- und länderspezifischen Analysen sowie von Modellen, die Bildung und Fertilitätsentscheidungen vorausgehende Motivlagen berücksichtigen, betrachtet. Darüber hinaus werden Möglichkeiten und Grenzen molekulargenetischer Studien besprochen, bevor schließlich ein kurzer Überblick über Arbeiten aus der evolutionären Anthropologie und Biologie mit einem Fokus auf den Aspekt der natürlichen Auslese gegeben wird. Es zeigt sich, dass biologische und genetische Faktoren für das Verständnis und die Vorhersage von Fertilitätsmerkmalen relevant sind und dass ihre Interaktion mit sozialen Umweltfaktoren zentral für das Verständnis von Fertilitätsoutcomes ist. Für die Vorhersage zukünftiger Fertilitätstrends wird die Untersuchung des Zusammenspiels von Gen-Umwelt-Faktoren sowie die Nutzbarmachung neuer Datenquellen und die Integration neuer Methoden eine wesentliche Rolle spielen.

  13. The efficient cell-SELEX strategy, Icell-SELEX, using isogenic cell lines for selection and counter-selection to generate RNA aptamers to cell surface proteins.

    Science.gov (United States)

    Takahashi, Masaki; Sakota, Eri; Nakamura, Yoshikazu

    2016-12-01

    Aptamers are short single-stranded nucleic acid molecules that are selected in vitro from a large random sequence library based on their high and specific affinity to a target molecule by a process known as SELEX. Cell-SELEX that employs whole living cells overexpressing the defined cell surface proteins (for selection) and appropriate mock cells (for counter-selection) has been widely used as a valid and feasible method for generating aptamers against specific cell surface proteins. However, the endogenous expression of target proteins in mock cells or the heterogeneity of surface proteins between selection and counter-selection cells often impeded the isolation of proper aptamers against target proteins. To solve this problem, we developed "Isogenic cell-SELEX" (Icell SELEX in short) method, in which isogenic cell lines were manipulated for counter-selection by microRNA-mediated silencing and for selection by overexpression of target proteins. As a model experiment, we targeted integrin alpha V (ITGAV), which is a major transmembrane receptor expressed in almost all the cells, and established ITGAV-overexpressed and -downregulated HEK293 cells for selection and counter-selection, respectively. By taking advantage of a hundred-fold difference in the expression level of ITGAV between these two isogenic cell lines, we easily isolated several anti-ITGAV aptamers, whose binding to the cell-surface ITGAV was confirmed by flow cytometry with the dissociation constant of 300-400 nM range. We assume that Icell-SELEX could be applicable to a wide range of cell-surface proteins including various transmembrane proteins of biological and pharmacological significance. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  14. 茴香茎叶提取物对菜粉蝶生物活性的影响研究%Preliminary Studies on Biological Activity of Extracts from Foeniculum vulgare to Pieris rapae L

    Institute of Scientific and Technical Information of China (English)

    吴利民; 陆宁海; 蒋国锋; 魏旺; 蒋坤; 李德兵

    2012-01-01

    为了探索番茄茎叶提取物对菜粉蝶生物活性的影响.采用水蒸气蒸馏法从茴香( Foeniculum vulgare)茎叶中提取获得其挥发性物质,测定了茴香提取物在室内对菜青虫的拒食作用及对菜粉蝶的产卵忌避作用.结果表明:茴香粗提取物对菜青虫3龄幼虫具有较强的拒食活性,且非选择性的拒食作用均大于选择性的拒食作用;茴香提取物对菜粉蝶的产卵具有较强的忌避作用.%This paper objective was to explore biological activity of extracts from Foeniculum vulgare to Pieris rapae. Extract volatile matter was extracted from stem and leaves of Foeniculum vulgare Mill by steam distillation. Biologial activity of antifeedant effect and oviposition repellent on Pieris rapae L. Was tested with extraction of Foeniculum vulgare. The results showed that extracts of Foeniculum vulgare have strong antifeedant effect on Pieris rapae 3-instar larvae, which the antifeeding activities of Pieris rapae L. Of non-choice was higher than that of choice tests. Moreover, that extracts of Foeniculum vulgare had strong effect of repellent effect on Pieris rapae.

  15. Leishmania donovani tyrosyl-tRNA synthetase structure in complex with a tyrosyl adenylate analog and comparisons with human and protozoan counterparts.

    Science.gov (United States)

    Barros-Álvarez, Ximena; Kerchner, Keshia M; Koh, Cho Yeow; Turley, Stewart; Pardon, Els; Steyaert, Jan; Ranade, Ranae M; Gillespie, J Robert; Zhang, Zhongsheng; Verlinde, Christophe L M J; Fan, Erkang; Buckner, Frederick S; Hol, Wim G J

    2017-07-01

    The crystal structure of Leishmania donovani tyrosyl-tRNA synthetase (LdTyrRS) in complex with a nanobody and the tyrosyl adenylate analog TyrSA was determined at 2.75 Å resolution. Nanobodies are the variable domains of camelid heavy chain-only antibodies. The nanobody makes numerous crystal contacts and in addition reduces the flexibility of a loop of LdTyrRS. TyrSA is engaged in many interactions with active site residues occupying the tyrosine and adenine binding pockets. The LdTyrRS polypeptide chain consists of two pseudo-monomers, each consisting of two domains. Comparing the two independent chains in the asymmetric unit reveals that the two pseudo-monomers of LdTyrRS can bend with respect to each other essentially as rigid bodies. This flexibility might be useful in the positioning of tRNA for catalysis since both pseudo-monomers in the LdTyrRS chain are needed for charging tRNA(Tyr). An "extra pocket" (EP) appears to be present near the adenine binding region of LdTyrRS. Since this pocket is absent in the two human homologous enzymes, the EP provides interesting opportunities for obtaining selective drugs for treating infections caused by L. donovani, a unicellular parasite causing visceral leishmaniasis, or kala azar, which claims 20,000 to 30,000 deaths per year. Sequence and structural comparisons indicate that the EP is a characteristic which also occurs in the active site of several other important pathogenic protozoa. Therefore, the structure of LdTyrRS could inspire the design of compounds useful for treating several different parasitic diseases. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Probing phosphoethanolamine-containing lipids in membranes with duramycin/cinnamycin and aegerolysin proteins.

    Science.gov (United States)

    Hullin-Matsuda, Françoise; Makino, Asami; Murate, Motohide; Kobayashi, Toshihide

    2016-11-01

    In this mini-review, we summarize current knowledge about the lipid-binding characteristics of two types of toxins used to visualize the membrane distribution of phosphoethanolamine-containing lipid species: the glycerophospholipid, phosphatidylethanolamine (PE) and the sphingolipid, ceramide phosphoethanolamine (CPE). The lantibiotic cinnamycin and the structurally-related peptide duramycin produced by some Gram-positive bacteria were among the first toxins characterized by their specificity for PE which is widely present in animal kingdoms from bacteria to mammals. These toxins promoted their binding to PE-containing membranes by changing membrane curvature and by inducing transbilayer lipid movement. The recognition of the conical shape and negative curvature adopted by the PE species within the membrane, is important to understand how lipid-peptide interaction can occur. Three mushroom-derived proteins belonging to the aegerolysin family, pleurotolysin A2, ostreolysin and erylysin A were recently described as efficient tools to visualize the membrane distribution of CPE which is found in trace amounts in mammalian cells but in higher amounts in some developmental stages of lower eukaryotes like Trypanosoma and in invertebrates such as Drosophila. The recent development of lantibiotic-based PE-specific and aegerolysin-based CPE-specific probes is useful to visualize and specify the role of these lipids in various pathophysiological events such as cell division, apoptosis, tumor vasculature and parasite developmental stages. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  17. [Hunger and satiety factors in the regulation of pleasure associated with feeding behavior].

    Science.gov (United States)

    Fetissov, Sergueï O

    2016-01-01

    obesity and anorexia and the possible underlying mechanisms are discussed. © Société de Biologie, 2017.

  18. Apprendre, un moment de vie ? Savoir, expérience et rapport au vivant

    Directory of Open Access Journals (Sweden)

    Noack Julie

    2015-01-01

    Full Text Available L’objectif de cette communication est de comparer sur le plan pédagogique deux conceptions du rapport entre science et vivant, diamétralement opposées sur le plan épistémologique. En se basant sur un livre [1], une conférence [2] et un entretien [3], on analysera l’expérience de pensée par laquelle le biologiste et épistémologue Jean-Jacques Kupiec fait se sentir vivants les apprenants afin de mieux les conscientiser aux réquisits de la démarche scientifique. On comparera ensuite les motivations de Kupiec avec les idées pédagogiques du philosophe-médecin Georges Canguilhem (1904–1995 afin d’essayer de comprendre pourquoi l’un et l’autre jugent pertinent de faire remarquer à l’apprenant qu’il est actuellement en vie. Car, malgré des conceptions du vivant diamétralement opposées, Canguilhem et Kupiec se rejoignent sur l’idée que l’expérience vitale joue un rôle crucial – que ce soit en positif ou en négatif, comme un obstacle épistémologique ou comme un levier heuristique – dans l’apprentissage et la pratique de la biologie ou de la médecine. Prendre en charge cette expérience constitue peut-être une ressource face au double défi (scientifique et éthico-politique qui échoit à l’éducation aux sciences du vivant.

  19. [Epigenetics and Nutrition: maternal nutrition impacts on placental development and health of offspring].

    Science.gov (United States)

    Panchenko, Polina E; Lemaire, Marion; Fneich, Sara; Voisin, Sarah; Jouin, Mélanie; Junien, Claudine; Gabory, Anne

    2015-01-01

    early conditioning and the marked sexual dimorphism it is associated to. © Société de Biologie, 2015.

  20. L'analyse par activation de neutrons de réacteur

    Science.gov (United States)

    Meyer, G.

    2003-02-01

    Quand les neutrons traversent la matière, certains sont transmis sans interaction, les autres interagissent avec le milieu traversé par diffusion et par absorption. Ce phénomène d'absorption est utilisé pour se protéger des neutrons, mais aussi pour les détecter; il peut également être utilisé pour identifier les noyaux “absorbants" et ainsi analyser le milieu traversé. En effet par différentes réactions nucléaires (n,γ), (n,p), (n,α), (n,fission), on obtient des noyaux résiduels qui sont souvent radioactifs; on dit que l'échantillon est “activé". Si l'on connaît le rendement d'activation et donc le pourcentage de noyaux ainsi “transmutés", les mesures de radioactivité induite vont permettre de déterminer la composition de l'échantillon irradié. Cette méthode dite d'analyse par activation neutronique est pratiquée depuis la découverte du neutron. Elle a permis grâce à sa sélectivité et à sa sensibilité d'avoir accès au domaine des traces et des ultra-traces dans des champs d'application très divers comme la métallurgie, l'archéologie, la biologie, la géochimie etc...

  1. Caffeine inhibition of GLUT1 is dependent on the activation state of the transporter.

    Science.gov (United States)

    Gunnink, Leesha K; Busscher, Brianna M; Wodarek, Jeremy A; Rosette, Kylee A; Strohbehn, Lauren E; Looyenga, Brendan D; Louters, Larry L

    2017-06-01

    Caffeine has been shown to be a robust uncompetitive inhibitor of glucose uptake in erythrocytes. It preferentially binds to the nucleotide-binding site on GLUT1 in its tetrameric form and mimics the inhibitory action of ATP. Here we demonstrate that caffeine is also a dose-dependent, uncompetitive inhibitor of 2-deoxyglucose (2DG) uptake in L929 fibroblasts. The inhibitory effect on 2DG uptake in these cells was reversible with a rapid onset and was additive to the competitive inhibitory effects of glucose itself, confirming that caffeine does not interfere with glucose binding. We also report for the first time that caffeine inhibition was additive to inhibition by curcumin, suggesting distinct binding sites for curcumin and caffeine. In contrast, caffeine inhibition was not additive to that of cytochalasin B, consistent with previous data that reported that these two inhibitors have overlapping binding sites. More importantly, we show that the magnitude of maximal caffeine inhibition in L929 cells is much lower than in erythrocytes (35% compared to 90%). Two epithelial cell lines, HCLE and HK2, have both higher concentrations of GLUT1 and increased basal 2DG uptake (3-4 fold) compared to L929 cells, and subsequently display greater maximal inhibition by caffeine (66-70%). Interestingly, activation of 2DG uptake (3-fold) in L929 cells by glucose deprivation shifted the responsiveness of these cells to caffeine inhibition (35%-70%) without a change in total GLUT1 concentration. These data indicate that the inhibition of caffeine is dependent on the activity state of GLUT1, not merely on the concentration. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  2. Adipocyte lipolysis and insulin resistance.

    Science.gov (United States)

    Morigny, Pauline; Houssier, Marianne; Mouisel, Etienne; Langin, Dominique

    2016-06-01

    Obesity-induced insulin resistance is a major risk factor for the development of type 2 diabetes. Basal fat cell lipolysis (i.e., fat cell triacylglycerol breakdown into fatty acids and glycerol in the absence of stimulatory factors) is elevated during obesity and is closely associated with insulin resistance. Inhibition of adipocyte lipolysis may therefore be a promising therapeutic strategy for treating insulin resistance and preventing obesity-associated type 2 diabetes. In this review, we explore the relationship between adipose lipolysis and insulin sensitivity. After providing an overview of the components of fat cell lipolytic machinery, we describe the hypotheses that may support the causality between lipolysis and insulin resistance. Excessive circulating fatty acids may ectopically accumulate in insulin-sensitive tissues and impair insulin action. Increased basal lipolysis may also modify the secretory profile of adipose tissue, influencing whole body insulin sensitivity. Finally, excessive fatty acid release may also worsen adipose tissue inflammation, a well-known parameter contributing to insulin resistance. Partial genetic or pharmacologic inhibition of fat cell lipases in mice as well as short term clinical trials using antilipolytic drugs in humans support the benefit of fat cell lipolysis inhibition on systemic insulin sensitivity and glucose metabolism, which occurs without an increase of fat mass. Modulation of fatty acid fluxes and, putatively, of fat cell secretory pattern may explain the amelioration of insulin sensitivity whereas changes in adipose tissue immune response do not seem involved. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  3. Candida albicans biofilm on titanium: effect of peroxidase precoating

    Directory of Open Access Journals (Sweden)

    Mohamed Ahariz

    2010-08-01

    Full Text Available Mohamed Ahariz1, Philippe Courtois1,21Laboratory of Experimental Hormonology, Université Libre de Bruxelles, Brussels, 2UER de Biologie Médicale, Haute Ecole Francisco Ferrer, Brussels, BelgiumAbstract: The present study aimed to document Candida albicans biofilm development on titanium and its modulation by a peroxidase-precoated material which can generate antimicrobials, such as hypoiodite or hypothiocyanite, from hydrogen peroxide, iodide, or thiocyanate. For this purpose, titanium (powder or foil was suspended in Sabouraud liquid medium inoculated with C. albicans ATCC10231. After continuous stirring for 2–21 days at room temperature, the supernatant was monitored by turbidimetry at 600 nm and titanium washed three times in sterile Sabouraud broth. Using the tetrazolium salt MTT-formazan assay, the titanium-adherent fungal biomass was measured as 7.50 ± 0.60 × 106 blastoconidia per gram of titanium powder (n = 30 and 0.50 ± 0.04 × 106 blastoconidia per cm² of titanium foil (n = 12. The presence of yeast on the surface of titanium was confirmed by microscopy both on fresh preparations and after calcofluor white staining. However, in the presence of peroxidase systems (lactoperoxidase with substrates such as hydrogen peroxide donor, iodide, or thiocyanate, Candida growth in both planktonic and attached phases appeared to be inhibited. Moreover, this study demonstrates the possible partition of peroxidase systems between titanium material (peroxidase-precoated and liquid environment (containing peroxidase substrates to limit C. albicans biofilm formation.Keywords: adhesion, material, oral, yeast

  4. Structural and biochemical characterisation of VaF1, a P-IIIa fibrinogenolytic metalloproteinase from Vipera ammodytes ammodytes venom.

    Science.gov (United States)

    Leonardi, Adrijana; Sajevic, Tamara; Latinović, Zorica; Pungerčar, Jože; Balija, Maja Lang; Bakija, Alenka Trampuš; Vidmar, Robert; Halassy, Beata; Križaj, Igor

    2015-02-01

    A high molecular mass metalloproteinase with α-fibrinogenolytic activity, termed VaF1, was purified from nose-horned viper (Vipera ammodytes ammodytes) venom. Subcutaneous injection of 9 μg of VaF1 did not induce bleeding in rats. Nevertheless, in vitro it degraded collagen IV, nidogen and fibronectin, components of the extracellular matrix, although with low efficacy and narrow specificity. VaF1 would be expected to exert anti-coagulant action, due to its hydrolysis of fibrinogen, factor X, prothrombin and plasminogen, plasma proteins involved in blood coagulation. The enzyme is a single-chain glycoprotein with a molecular mass of 49.7 kDa, as determined by mass spectrometry, and multiple isoelectric points centred at pH 5.8. The complete amino acid sequence of the precursor of VaF1 was deduced by cloning and sequencing its cDNA. Composed of metalloproteinase, disintegrin-like and cysteine-rich domains, VaF1 is a typical P-IIIa subclass snake venom metalloproteinase. Although it possesses a collagen-binding sequence in its disintegrin-like domain, VaF1 displayed no effect on collagen-induced platelet aggregation in vitro. Two consensus N-glycosylation sites are present in the sequence of VaF1, however, the extent of its glycosylation is low, only 5.2% of the total molecular mass. Interestingly, in standard experimental conditions VaF1 is not recognised by antiserum against the whole venom, so it can contribute to post-serotherapy complications, such as ineffective blood coagulation, in the envenomed patient. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  5. Iron nanoparticles increase 7-ketocholesterol-induced cell death, inflammation, and oxidation on murine cardiac HL1-NB cells

    Directory of Open Access Journals (Sweden)

    Edmond Kahn

    2010-03-01

    Full Text Available Edmond Kahn1, Mauhamad Baarine2, Sophie Pelloux3, Jean-Marc Riedinger4, Frédérique Frouin1, Yves Tourneur3, Gérard Lizard21INSE RM U678/UMR – S UPMC, IFR 14, CH U Pitié-Salpêtrière, 75634 Paris Cedex 13, France; 2Centre de Recherche INSE RM U866, Equipe Biochimie Métabolique et Nutritionnelle – Université de Bourgogne, Faculté des Sciences Gabriel, 6 Bd Gabriel, 21000 Dijon, France; 3Centre Commun de Quantimétrie, Université Lyon 1; Université de Lyon, Lyon, France; 4Département de Biologie et de Pathologie des Tumeurs, Centre Georges François-Leclerc, 21000 Dijon, FranceObjective: To evaluate the cytotoxicity of iron nanoparticles on cardiac cells and to determine whether they can modulate the biological activity of 7-ketocholesterol (7KC involved in the development of cardiovascular diseases. Nanoparticles of iron labeled with Texas Red are introduced in cultures of nonbeating mouse cardiac cells (HL1-NB with or without 7-ketocholesterol 7KC, and their ability to induce cell death, pro-inflammatory and oxidative effects are analyzed simultaneously.Study design: Flow cytometry (FCM, confocal laser scanning microscopy (CLSM, and subsequent factor analysis image processing (FAMIS are used to characterize the action of iron nanoparticles and to define their cytotoxicity which is evaluated by enhanced permeability to SYTOX Green, and release of lactate deshydrogenase (LDH. Pro-inflammatory effects are estimated by ELISA in order to quantify IL-8 and MCP-1 secretions. Pro-oxidative effects are measured with hydroethydine (HE.Results: Iron Texas Red nanoparticles accumulate at the cytoplasmic membrane level. They induce a slight LDH release, and have no inflammatory or oxidative effects. However, they enhance the cytotoxic, pro-inflammatory and oxidative effects of 7KC. The accumulation dynamics of SYTOX Green in cells is measured by CLSM to characterize the toxicity of nanoparticles. The emission spectra of SYTOX Green and

  6. Stimuli de l'environnement, organes des sens et comportement des Monogènes juvéniles et adultes

    Directory of Open Access Journals (Sweden)

    KEARN G. C.

    1993-01-01

    Full Text Available Lorsque les larves de Monogènes (oncomiracidiums établissent leur premier contact avec l'hôte, cela correspond à un changement fondamental dans leur mode de vie. La disparition de quelques structures sensorielles et l'acquisition de nouvelles en témoignent ; mais il existe certainement d'autres types de changements encore inconnus au niveau du système nerveux. Le développement larvaire lui-même, à ce moment là, est initié par des facteurs eux aussi inconnus. Nos connaissances du rôle des facteurs de l'environnement sur la vie des stades parasites juvéniles et adultes sont très limitées. Chez Entobdella soleae, parasite cutané de la Sole, il existe une réponse comportementale au changement de concentration d'oxygène ; chez l'adulte d'Encotyllabe caballeroi, chez qui des yeux se développent chez les post-larves, une réponse nette à la lumière existe. Les yeux persistants que l'on trouve chez d'autres Monogènes adultes, doivent avoir un rôle plus subtil dans le comportement. Le courant d'eau peut influencer le choix du site de fixation ou le développement dissymétrique du hapteur chez les Polyopisthocotylea, mais chez Entobdella soleae, parasite cutané, c'est le premier contact, et non une réponse au courant d'eau qui est déterminant dans l'orientation, la locomotion et éventuellement la migration. Ce contact est aussi certainement important dans la locomotion de certains parasites branchiaux comme Tetraonchus monenteron. L'attraction par des phéromones n'a pas été démontrée chez les Monogènes et l'environnement turbulent de la plupart d'entre eux rend ce mode de communication peu adapté. Cependant, les relations particulières entre E. soleae et son hôte poisson plat procurent une situation où ce phénomène serait possible et avantageux. Bien que les hormones des hôtes apparaissent jouer un rôle dans la biologie de la reproduction des hématophages comme les Polystomes, la démonstration exp

  7. Conséquences écologiques des introductions dans les hydrosystèmes : essai de synthèse

    Directory of Open Access Journals (Sweden)

    HAURY J.

    1997-01-01

    Full Text Available Un essai de bilan des effets écologiques des introductions d'espèces est présenté à partir des exposés des orateurs de ce colloque et de la bibliographie. L'aspect inéluctable de la dispersion des espèces au cours du temps et l'efficacité toute relative des barrières intracontinentales qui s'y opposent sont soulignés. Les mécanismes en cause - vagilité et fécondité des espèces introduites, efficacité des barrières, structure des réseaux trophiques récepteurs, degré de saturation de leurs niches écologiques - sont étudiés en regard du fonctionnement des hydrosystèmes, montrant la complexité du problème. Des effets écologiques très variés sont décrits, dont beaucoup sont non intentionnels et inattendus ; un exemple bibliographique est développé, mettant en évidence la diversité des effets de la même introduction selon le milieu récepteur. Il en ressort la nécessité préliminaire absolue d'examiner à la fois la biologie des espèces à introduire et le fonctionnement de l'écosystème récepteur. Un principe de précaution est préconisé face à toute introduction volontaire, et une réglementation sévère et efficace face aux introductions involontaires. Le besoin d'une permanence d'agents de terrain pour établir une veille écologique est souligné. Face au manque de données objectives, des recherches scientifiques sur les effets écologiques des introductions passées ou possibles doivent être initiées ou poursuivies dans un cadre écosystémique, impliquant au minimum un suivi des écosystèmes risquant d'être colonisés.

  8. A review of current and future treatment strategies for malignant astrocytomas in adults

    Energy Technology Data Exchange (ETDEWEB)

    Nieder, C. [Texas Univ., Houston, TX (United States). Dept. of Experimental Radiation Oncology; Nestle, U. [Universitaet des Saarlandes, Homburg/Saar (Germany). Radiologische Klinik

    2000-06-01

    This review discusses available laboratory and clinical data as well as recent advances in our knowledge about prognostic factors and their implications for the design of future clinical trials. Results: Elucidation of the biology of malignant astrocytomas allowed for development of rational new approaches, such as gene therapy and immunotherapy, which could interfere with established treatment regimens or being used independently. Possible strategies include the restoration of defective cancer-inhibitory genes, cell transduction or transfection with antisense DNA corresponding to genes coding for growth factors and their receptors, or with the so-called suicide genes. Several antiangiogenic approaches such as administration of thalidomide, protamine, or monoclonal antibodies against vascular endothelial growth factor have been developed, too. Further treatment possibilities include modulation of drug resistance, e.g. by P-glycoprotein antagonists or O6-alkyl-guanine-DNA-transferase inhibitors, inhibition of matrix metalloproteinases, inhibition of protein kinase C, and administration of agents such as phenylbutyrate or valproic acid that showed promising antiproliferative effects in vitro. Conclusions: Several rational new approaches are now entering clinical trials. In the light of limited survival after standard treatment it is recommended that patients should be offered participation in such trials. (orig.) [German] In dieser Arbeit werden sowohl die verfuegbaren Labor- und klinischen Daten als auch die aktuellen Fortschritte auf dem Gebiet prognostischer Faktoren und deren Bedeutung fuer das Design kuenftiger klinischer Studien diskutiert. Ergebnisse: Die Aufklaerung der Biologie dieser Tumoren ermoeglichte die Entwicklung rationaler neuer Strategien, zum Beispiel basierend auf der Gen- und Immuntherapie, die entweder zusammen mit etablierten Methoden oder allein anwendbar sind. Moegliche Strategien bestehen in der Wiederherstellung defekter

  9. Dysregulated miR-127-5p contributes to type II collagen degradation by targeting matrix metalloproteinase-13 in human intervertebral disc degeneration.

    Science.gov (United States)

    Hua, Wen-Bin; Wu, Xing-Huo; Zhang, Yu-Kun; Song, Yu; Tu, Ji; Kang, Liang; Zhao, Kang-Cheng; Li, Shuai; Wang, Kun; Liu, Wei; Shao, Zeng-Wu; Yang, Shu-Hua; Yang, Cao

    2017-08-01

    Intervertebral disc degeneration (IDD) is a chronic disease associated with the degradation of extracellular matrix (ECM). Matrix metalloproteinase (MMP)-13 is a major enzyme that mediates the degradation of ECM components. MMP-13 has been predicted to be a potential target of miR-127-5p. However, the exact function of miR-127-5p in IDD is still unclear. We designed this study to evaluate the correlation between miR-127-5p level and the degeneration of human intervertebral discs and explore the potential mechanisms. miR-127-5p levels and MMP-13 mRNA levels were detected by quantitative real-time polymerase chain reaction (qPCR). To determine whether MMP-13 is a target of miR-127-5p, dual luciferase reporter assays were performed. miR-127-5p mimic and miR-127-5p inhibitor were used to overexpress or downregulate miR-127-5p expression in human NP cells, respectively. Small interfering RNA (siRNA) was used to knock down MMP-13 expression in human NP cells. Type II collagen expression in human NP cells was detected by qPCR, western blotting, and immunofluorescence staining. We confirmed that miR-127-5p was significantly downregulated in nucleus pulposus (NP) tissue of degenerative discs and its expression was inversely correlated with MMP-13 mRNA levels. We reveal that MMP-13 may act as a target of miR-127-5p. Expression of miR-127-5p was inversely correlated with type II collagen expression in human NP cells. Moreover, suppression of MMP-13 expression by siRNA blocked downstream signaling and increased type II collagen expression. Dysregulated miR-127-5p contributed to the degradation of type II collagen by targeting MMP-13 in human IDD. Our findings highlight that miR-127-5p may serve as a new therapeutic target in IDD. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Structural studies with BnSP-7 reveal an atypical oligomeric conformation compared to phospholipases A2-like toxins.

    Science.gov (United States)

    de Lima, Lino Fernando G; Borges, Rafael J; Viviescas, Maria Alejandra; Fernandes, Carlos A H; Fontes, Marcos R M

    2017-07-24

    exert its myotoxic activity like other PLA2-like proteins. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Anti-obesogenic effects of WY14643 (PPAR-alpha agonist): Hepatic mitochondrial enhancement and suppressed lipogenic pathway in diet-induced obese mice.

    Science.gov (United States)

    Veiga, Flavia Maria Silva; Graus-Nunes, Francielle; Rachid, Tamiris Lima; Barreto, Aline Barcellos; Mandarim-de-Lacerda, Carlos Alberto; Souza-Mello, Vanessa

    2017-09-01

    expressions in a murine obesity model. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  12. Glycosylation is important for legumain localization and processing to active forms but not for cystatin E/M inhibitory functions.

    Science.gov (United States)

    Lunde, Ngoc Nguyen; Haugen, Mads Haugland; Bodin Larsen, Kristina Broe; Damgaard, Ingrid; Pettersen, Solveig J; Kasem, Roya; Rut, Wioletta; Drag, Marcin; Poreba, Marcin; Johansen, Harald Thidemann; Solberg, Rigmor

    2017-08-01

    , whereas the inhibitory property of cystatin E/M is independent of the glycosylation status. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  13. Estrogen-enhanced apical and basolateral secretion of apolipoprotein B-100 by polarized trophoblast-derived BeWo cells.

    Science.gov (United States)

    Kamper, Miriam; Mittermayer, Florian; Cabuk, Rosalinda; Gelles, Katharina; Ellinger, Isabella; Hermann, Marcela

    2017-07-01

    including FECs, which were herein demonstrated to express apoB receptors, LRP2 and LDLR, respectively. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  14. Two persistent organic pollutants which act through different xenosensors (alpha-endosulfan and 2,3,7,8 tetrachlorodibenzo-p-dioxin) interact in a mixture and downregulate multiple genes involved in human hepatocyte lipid and glucose metabolism.

    Science.gov (United States)

    Ambolet-Camoit, Ariane; Ottolenghi, Chris; Leblanc, Alix; Kim, Min Ji; Letourneur, Franck; Jacques, Sébastien; Cagnard, Nicolas; Guguen-Guillouzo, Christiane; Barouki, Robert; Aggerbeck, Martine

    2015-09-01

    et Biologie Moléculaire (SFBBM). All rights reserved.

  15. Exploring binding characteristics and the related competition of different protein-bound uremic toxins.

    Science.gov (United States)

    Deltombe, Olivier; de Loor, Henriette; Glorieux, Griet; Dhondt, Annemieke; Van Biesen, Wim; Meijers, Björn; Eloot, Sunny

    2017-08-01

    © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Disruption of phactr-1 pathway triggers pro-inflammatory and pro-atherogenic factors: New insights in atherosclerosis development.

    Science.gov (United States)

    Jarray, Rafika; Pavoni, Serena; Borriello, Lucia; Allain, Barbara; Lopez, Nicolas; Bianco, Sara; Liu, Wang-Qing; Biard, Denis; Demange, Luc; Hermine, Olivier; Garbay, Christiane; Raynaud, Françoise; Lepelletier, Yves

    2015-11-01

    , our result highlighted the pivotal role of phactr-1 protein in the pathogenesis of atherosclerosis. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  17. Biochemical characterization of Arabidopsis thaliana starch branching enzyme 2.2 reveals an enzymatic positive cooperativity.

    Science.gov (United States)

    Wychowski, A; Bompard, C; Grimaud, F; Potocki-Véronèse, G; D'Hulst, C; Wattebled, F; Roussel, X

    2017-09-01

    Starch Branching Enzymes (SBE) catalyze the formation of α(1 → 6) branching points on starch polymers: amylopectin and amylose. SBEs are classified in two groups named type 1 and 2. Both types are present in the entire plant kingdom except in some species such as Arabidopsis thaliana that expresses two type 2 SBEs: BE2.1 and BE2.2. The present work describes in vitro enzymatic characterization of the recombinant BE2.2. The function of recombinant BE2.2 was characterized in vitro using spectrophotometry assay, native PAGE and HPAEC-PAD analysis. Size Exclusion Chromatography separation and SAXS experiments were used to identify the oligomeric state and for structural analysis of this enzyme. Optimal pH and temperature for BE2.2 activity were determined to be pH 7 and 25 °C. A glucosyl donor of at least 12 residues is required for BE2.2 activity. The reaction results in the transfer in an α(1 → 6) position of a glucan preferentially composed of 6 glucosyl units. In addition, BE2.2, which has been shown to be monomeric in absence of substrate, is able to adopt different active forms in presence of branched substrates, which affect the kinetic parameters. BE2.2 has substrate specificity similar to those of the other type-2 BEs. We propose that the different conformations of the enzyme displaying more or less affinity toward its substrates would explain the adjustment of the kinetic data to the Hill equation. This work describes the enzymatic parameters of Arabidopsis BE2.2. It reveals for the first time conformational changes for a branching enzyme, leading to a positive cooperative binding process of this enzyme. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  18. Multicentre evaluation of the Bayer DAX system.

    Science.gov (United States)

    Morosini, L; Rossetti, M; Berti, P; Pallotti, G; Fabbri, V; Mambelli, M C; Franceschin, A; Dell'Anna, L; Cappelletti, P; Brocco, G

    1993-12-01

    The analytical performance of the DAX, a high-throughput random access analyser, was studied according to ECCLS guidelines (ECCLS Document Vol. 3, No. 2, Beuth Verlag, Berlin, 1986) in a multicentre evaluation involving four laboratories. The trial took about 4 months. Determinations of 12 analytes produced more than 60,000 data. The imprecision study on 3 control sera for all analytes gave a within-run CV (median of 4 laboratories) which never exceeded 3% and was below 2% in 94% of the results. The median between-day CV was less than 3% in 92% of the results, with a highest value of 5.0%. No significant drift was detected during the 5-hour work period. No relevant sample- and cuvette-related carry-over was found. The manufacturer's claims concerning linearity were fulfilled or exceeded. The recovery of the assigned values for the control sera (median of 4 laboratories) ranged from 94 to 106%. In the method comparison on patients' samples, deviations were statistically significant in some cases, due to differences either in the methods used or in the calibration of the systems used for comparison; the regression lines, as inspected visually, and the coefficients of correlation were, however, generally acceptable. Imprecision and inaccuracy were within the acceptability limits as recommended by the Société Française de Biologie Clinique (SFBC) (Biochim. Clin. 12 (1988) 284-327) and the Deutsche Gesellschaft für Klinische Chemie (DGKC) (Dt. Arztebl. 85 (11) (1988) A697-A712). The limits of acceptance, proposed more recently by Fraser et al. (Eur. J. Clin. Chem. Clin. Biochem. 30 (1992) 311-317), were met in thirty-three of thirty-six cases. The alpha-amylase assay was significantly affected by bilirubin and haemolysis; interferences for the remaining analytes were predictable and well-known from the literature. The rate of sample throughput was found to be in agreement with that claimed by the manufacturer. The software did not present problems and was readily

  19. Sciences juridiques et complexité.Un nouveau modèle d’analyse Legal Sciences and Complexity. A New Model

    Directory of Open Access Journals (Sweden)

    Danièle Bourcier

    2011-10-01

    Full Text Available Il est d’usage de dire que le droit devient de plus en plus complexe. Les institutions qui le régulent ont tenté d’agir sur les causes de ce phénomène et d’en endiguer les effets. Mais d’où vient ce sentiment d’un accroissement critique de la complexité normative ? Au-delà des remèdes apportés par les juristes, peut-on aller plus loin dans l’étude du droit comme système complexe ? Depuis quelques années, un nouveau champ disciplinaire se construit sous le thème Droit et Systèmes complexes. En effet, les sciences des systèmes complexes se sont développées dans beaucoup de disciplines, des sciences de l’univers à la biologie : nous faisons l’hypothèse que ce que l’on peut définir comme un nouveau modèle d’analyse apporte des représentations inédites de la complexité du droit permettant non seulement d’en découvrir les causes mais de faire émerger des conceptualisations plus pertinentes pour la comprendre et la gérer.We used to say that Law is becoming more and more complex. Legal institutions tried to act on the causes and to limit the effects. But from where does the feeling of a critical increasing of the normative complexity come? Beyond the remedies brought by lawyers, can we go further in the study of Law as a complex system?Since several years, a new field has emerged under the term of Law and complex systems. Indeed the sciences of complex systems have been developed in many disciplines from physics to biology: we do the hypothesis that these sciences can bring new representations to the legal complexity allowing for revealing the reasons but also to find out more relevant conceptualizations and tools.

  20. Le programme Génoplante, programme mobilisateur en génomique végétale

    Directory of Open Access Journals (Sweden)

    Caboche Michel

    2002-03-01

    Full Text Available Les enjeux de la génomique végétale sont immenses pour le secteur de la création variétale et concernent de multiples objectifs, allant de la réduction d’intrants à l’amélioration de la qualité des produits récoltés ou transformés. Une situation d’oligopole se met en place au niveau mondial avec quelques firmes provenant du secteur de la chimie, principalement aux États-Unis avec de très forts soutiens publics. En 1998, l’Inra, le CNRS, le Cirad, l’IRD pour le secteur public et Biogemma, Aventis Crop Ssciences et Bioplante pour le secteur privé s’engagent dans le programme Génoplante, acté, en février 1999, par le ministère de la Recherche, qui y apporte son soutien, pour une première période de cinq ans, afin de permettre à nos recherches, fondamentale et appliquée en biologie végétale, de rester compétitives. Le programme Génoplante comprend d’abord des programmes génériques : analyse fonctionnelle du génome d’Arabidopsis, génomique du riz, nouveaux outils d’analyse des génomes, bio-informatique, cibles importantes dans le génome des plantes cultivées. L’évaluation des projets soumis dans ce cadre est réalisée par des experts internationaux indépendants. Globalement, plus de 300 chercheurs sont impliqués dans ces projets. Il comprend aussi des programmes par espèces (blé, maïs, colza, tournesol, pois ayant chacun une partie générique (cartographie physique, banques génomiques, etc. et des projets concernant des caractères agronomiques, des stratégies de résistance aux maladies, ou des objectifs de caractérisation et d’amélioration de la qualité des produits.

  1. Proteomic analysis revealed alterations of the Plasmodium falciparum metabolism following salicylhydroxamic acid exposure

    Directory of Open Access Journals (Sweden)

    Torrentino-Madamet M

    2011-09-01

    Full Text Available Marylin Torrentino-Madamet1, Lionel Almeras2, Christelle Travaillé1, Véronique Sinou1, Matthieu Pophillat3, Maya Belghazi4, Patrick Fourquet3, Yves Jammes5, Daniel Parzy11UMR-MD3, Université de la Méditerranée, Antenne IRBA de Marseille (IMTSSA, Le Pharo, 2Unité de Recherche en Biologie et Epidémiologie Parasitaires, Antenne IRBA de Marseille (IMTSSA, Le Pharo, 3Centre d'Immunologie de Marseille Luminy, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Université de la Méditerranée, 4Centre d'Analyse Protéomique de Marseille, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Nord, 5UMR-MD2, Physiologie et Physiopathologie en Conditions d'Oxygénations Extrêmes, Institut Fédératif de Recherche Jean Roche, Faculté de Médecine Nord, Marseille, FranceObjectives: Although human respiratory metabolism is characterized by the mitochondrial electron transport chain, some organisms present a “branched respiratory chain.” This branched pathway includes both a classical and an alternative respiratory chain. The latter involves an alternative oxidase. Though the Plasmodium falciparum alternative oxidase is not yet identified, a specific inhibitor of this enzyme, salicylhydroxamic acid (SHAM, showed a drug effect on P. falciparum respiratory function using oxygen consumption measurements. The present study aimed to highlight the metabolic pathways that are affected in P. falciparum following SHAM exposure.Design: A proteomic approach was used to analyze the P. falciparum proteome and determine the metabolic pathways altered following SHAM treatment. To evaluate the SHAM effect on parasite growth, the phenotypic alterations of P. falciparum after SHAM or/and hyperoxia exposure were observed.Results: After SHAM exposure, 26 proteins were significantly deregulated using a fluorescent two dimensional-differential gel electrophoresis. Among these deregulated proteins

  2. Vitamin A status affects the plasma parameters and regulation of hepatic genes in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Li, Yang; Liu, Yang; Chen, Guoxun

    2017-06-01

    Vitamin A (VA) status regulates metabolism in rats. Whether VA status and availability of retinoic acid (RA) contribute to the insulin-regulated hepatic gene expression remains to be determined. Zucker lean rats with VA sufficient (VAS) or VA deficient (VAD) status were treated with streptozotocin (STZ) to induce insulin-dependent diabetes. They were treated with saline (STZ-VAS-C or STZ-VAD-C), RA (STZ-VAS-RA or STZ-VAD-RA), insulin (STZ-VAS-INS or STZ-VAD-INS), or insulin + RA (STZ-VAS-INS + RA or STZ-VAD-INS + RA) for 3 h. Insulin and insulin + RA treatments reduced tail tip blood glucose, raised plasma insulin and suppressed plasma β-hydroxybutyrate levels in both STZ-VAD and STZ-VAS rats. STZ-VAD-INS and STZ-VAD-INS + RA rats had lower plasma glucose levels than STZ-VAD-C rats had. STZ-VAD-INS and STZ-VAD-INS + RA rats had higher plasma leptin level and lower glucagon level than STZ-VAD-C rats did. Insulin treatment induced Gck, Srebp-1c and Fas and suppressed Pck1 expression levels in the liver of STZ-VAS and STZ-VAD rats. Interestingly, insulin treatment inhibited Cyp26a1 expression in STZ-VAD, but not STZ-VAS rats, whereas RA treatment induced it in both. RA treatment induced Gck expression only in STZ-VAD rats. Insulin + RA treatment further induced the Cyp26a1 and Gck expressions in STZ-VAD rats. The Srebp-1c expression levels of STZ-VAD-INS and STZ-VAD-INS + RA rats were higher than that of STZ-VAS-INS and STZ-VAS-INS + RA rats. The changes of Gck mRNA and glucokinase protein were consistent. In STZ-induced diabetic rats, VA is not required for insulin-regulated Gck, Srebp-1c, Fas and Pck1 expression. However, VA status altered responses of certain genes (Cyp26a1 and Srebp-1c) to insulin treatment. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  3. Méthodologies scientifiques et techniques pour approcher le vivant : comparaison des programmes scolaires France-Québec

    Directory of Open Access Journals (Sweden)

    Bernard Marie-Claude

    2015-01-01

    Full Text Available Les percées en matière de biotechnologie ouvrent la voie à des transformations d’une grande portée touchant au coeur du vivant : manipulation génétique, OGM ou utilisation de cellules souches, la biologie contemporaine soulève des questions porteuses d’enjeux qui trouvent écho dans la recherche et l’enseignement des sciences. Dans ce contexte, nous avons mené une étude sur l’analyse du discours des programmes officiels scolaires du préscolaire au secondaire en France et au Québec sur les questions entourant le vivant, en considérant que lesdits programmes contribuent autant à la structuration des situations éducatives qu’à l’intégration d’un point de vue sur la société et les savoirs. L’étude a été réalisée au regard de trois modes de questionnement : caractérisation du vivant, approches éthiques du vivant et méthodologies scientifiques et techniques. Les résultats de l’analyse montrent une évolution comparable des activités expérimentales suggérées au cours de la scolarité dans les deux pays. Celles-ci convoquent une pluralité de démarches (et non une seule et même démarche scientifique et proposent des tâches ouvertes aux élèves visant à leur donner de l’autonomie. Sur beaucoup de plans, les attentes semblent s’appuyer, en partie, sur un modèle socioconstructiviste de l’acquisition des connaissances. Les façons de favoriser les rencontres du « vivant » diffèrent quant à elles.

  4. Erythropoietin and the use of a transgenic model of erythropoietin-deficient mice

    Directory of Open Access Journals (Sweden)

    Pichon A

    2016-04-01

    Full Text Available Aurélien Pichon,1–3 Florine Jeton,1,2 Raja El Hasnaoui-Saadani,4 Luciana Hagström,5 Thierry Launay,6 Michèle Beaudry,1 Dominique Marchant,1 Patricia Quidu,1 Jose-Luis Macarlupu,7 Fabrice Favret,8 Jean-Paul Richalet,1,2 Nicolas Voituron1,2 1Laboratory “Hypoxia and Lung” EA 2363, University Paris 13, Sorbonne Paris Cité, Bobigny Cedex, 2Laboratory of Excellence GR-Ex, Paris, 3Laboratory MOVE EA 6314, FSS, Poitiers University, Poitiers, France; 4Research Unit, College of Medicine, Princess Noura University, Riyadh, Saudi Arabia; 5Laboratório Interdisciplinar de Biociências, Universidade de Brasília, Brasília, Brazil; 6Unité de Biologie Intégrative des Adaptations à l'Exercice, University Paris Saclay and Genopole®, University Sorbonne-Paris-Cité, Paris, France; 7High Altitude Unit, Laboratories for Research and Development, Universidad Peruana Cayetano Heredia, Lima, Peru; 8Laboratory “Mitochondrie, Stress Oxydant et Protection Musculaire” EA 3072, University of Strasbourg, Strasbourg, France Abstract: Despite its well-known role in red blood cell production, it is now accepted that erythropoietin (Epo has other physiological functions. Epo and its receptors are expressed in many tissues, such as the brain and heart. The presence of Epo/Epo receptors in these organs suggests other roles than those usually assigned to this protein. Thus, the aim of this review is to describe the effects of Epo deficiency on adaptation to normoxic and hypoxic environments and to suggest a key role of Epo on main physiological adaptive functions. Our original model of Epo-deficient (Epo-TAgh mice allowed us to improve our knowledge of the possible role of Epo in O2 homeostasis. The use of anemic transgenic mice revealed Epo as a crucial component of adaptation to hypoxia. Epo-TAgh mice survive well in hypoxic conditions despite low hematocrit. Furthermore, Epo plays a key role in neural control of ventilatory acclimatization and response to

  5. DHEA-induced modulation of renal gluconeogenesis, insulin sensitivity and plasma lipid profile in the control- and dexamethasone-treated rabbits. Metabolic studies.

    Science.gov (United States)

    Kiersztan, Anna; Nagalski, Andrzej; Nalepa, Paweł; Tempes, Aleksandra; Trojan, Nina; Usarek, Michał; Jagielski, Adam K

    2016-02-01

    dexP-evoked effects, it seems likely, that its supplementation might be beneficial to patients treated with glucocorticoids. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  6. Actinomycosis: etiology, clinical features, diagnosis, treatment, and management

    Directory of Open Access Journals (Sweden)

    Valour F

    2014-07-01

    Full Text Available Florent Valour,1–3 Agathe Sénéchal,1,2 Céline Dupieux,2–4 Judith Karsenty,1,2 Sébastien Lustig,2,5 Pierre Breton,2,6 Arnaud Gleizal,2,7 Loïc Boussel,2,8,9 Frédéric Laurent,2–4 Evelyne Braun,1 Christian Chidiac,1–3 Florence Ader,1–3 Tristan Ferry1–3 1Service des Maladies Infectieuses et Tropicales, Hospices Civils de Lyon, Groupement Hospitalier Nord, Lyon, France; 2Université Claude Bernard Lyon 1, Lyon, France; 3Centre International de Recherche en Infectiologie, CIRI, INSERM U1111, CNRS UMR5308, ENS de Lyon, UCBL1, Lyon, France; 4Laboratoire de Bactériologie, Centre de Biologie du Nord, Hospices Civils de Lyon, Groupement Hospitalier Nord, Lyon, France; 5Chirurgie Orthopédique, Hospices Civils de Lyon, Groupement Hospitalier Nord, Lyon, France; 6Stomatologie et Chirurgie Maxillo-faciale, Hospices Civils de Lyon, Groupement Hospitalier Sud, Lyon, France; 7Chirurgie Maxillo-faciale, Hospices Civils de Lyon, Groupement Hospitalier Nord, Lyon, France; 8Radiologie, Hospices Civils de Lyon, Groupement Hospitalier Nord, Lyon, France; 9Creatis, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA Lyon, Lyon, France Abstract: Actinomycosis is a rare chronic disease caused by Actinomyces spp., anaerobic Gram-positive bacteria that normally colonize the human mouth and digestive and genital tracts. Physicians must be aware of typical clinical presentations (such as cervicofacial actinomycosis following dental focus of infection, pelvic actinomycosis in women with an intrauterine device, and pulmonary actinomycosis in smokers with poor dental hygiene, but also that actinomycosis may mimic the malignancy process in various anatomical sites. Bacterial cultures and pathology are the cornerstone of diagnosis, but particular conditions are required in order to get the correct diagnosis. Prolonged bacterial cultures in anaerobic conditions are necessary to identify the bacterium and typical microscopic findings include necrosis with

  7. Vibrations et relaxations dans les molécules biologiques. Apports de la diffusion incohérente inélastique de neutrons

    Science.gov (United States)

    Zanotti, J.-M.

    2005-11-01

    Le présent document ne se veut pas un article de revue mais plutôt un élément d'initiation à une technique encore marginale en Biologie. Le lecteur est supposé être un non spécialiste de la diffusion de neutrons poursuivant une thématique à connotation biologique ou biophysique mettant en jeu des phénomènes dynamiques. En raison de la forte section de diffusion incohérente de l'atome d'hydrogène et de l'abondance de cet élément dans les protéines, la diffusion incohérente inélastique de neutrons est une technique irremplaçable pour sonder la dynamique interne des macromolécules biologiques. Après un rappel succinct des éléments théoriques de base, nous décrivons le fonctionnement de différents types de spectromètres inélastiques par temps de vol sur source continue ou pulsée et discutons leurs mérites respectifs. Les deux alternatives utilisées pour décrire la dynamique des protéines sont abordées: (i)l'une en termes de physique statistique, issue de la physique des verres, (ii) la seconde est une interprétation mécanistique. Nous montrons dans ce cas, comment mettre à profit les complémentarités de domaines en vecteur de diffusion et de résolution en énergie de différents spectromètres inélastiques de neutrons (temps de vol, backscattering et spin-écho) pour accéder, à l'aide d'un modèle physique simple, à la dynamique des protéines sur une échelle de temps allant d'une fraction de picoseconde à quelques nanosecondes.

  8. Biophysical assessment of aquaporin-9 as principal facilitative pathway in mouse liver import of glucogenetic glycerol.

    Science.gov (United States)

    Calamita, Giuseppe; Gena, Patrizia; Ferri, Domenico; Rosito, Anna; Rojek, Aleksandra; Nielsen, Søren; Marinelli, Raúl A; Frühbeck, Gema; Svelto, Maria

    2012-06-01

    . Refining the understanding of liver AQP9 in metabolic and energy homeostasis may reveal helpful for therapeutic purposes. Copyright © 2012 Soçiété Francaise des Microscopies and Société de Biologie Cellulaire de France.

  9. Antifungal membranolytic activity of the tyrocidines against filamentous plant fungi.

    Science.gov (United States)

    Rautenbach, Marina; Troskie, Anscha M; Vosloo, Johan A; Dathe, Margitta E

    2016-11-01

    selective towards ergosterol and possibly lipid rafts, but also point to additional targets such as the cell wall β-glucans that could modulate their activity. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  10. Les garrots de prélèvement, un drame chez le nourrisson: à propos de 3 cas

    Science.gov (United States)

    Ouangré, Edgar; Bazongo, Moussa; Ouédraogo, Isso; Zida, Maurice; Ouedraogo, Daouda; Sanou, Adama; Bonkoungou, Gilbert Patindé; Doamba, Rodrigue Namékinsba; Zongo, Nayi; Traore, Si Simon

    2016-01-01

    Le délai pour la levée d'un garrot sur un membre est limité, tout retard, surtout après la 3ème heure expose à un risque d'amputation de celui-ci. Notre objectif a été de rapporter trois cas de gangrène ischémique de membre par oubli d'un garrot après un prélèvement sanguin, afin d'interpeler le personnel soignant sur ses dangers. Il s'est agi de trois nourrissons dont deux de 3 mois et un de 5 mois, reçus aux urgences viscérales du CHU-Yalgado Ouédraogo pour tuméfaction du membre thoracique gauche. Dans leurs antécédents, on a noté une pose de garrot pour prélèvement de sang qui a été oublié pendant 24 heures dans deux cas et 48 heures dans un cas. L'examen avait retrouvé un œdème diffus associé à un sphacèle du membre supérieur remontant jusqu'au 1/3 moyen du bras; une abolition des pouls ulnaire et radial ainsi que de la sensibilité de la main dans 2 cas. Dans un cas les signes étaient atténués. Le diagnostic de gangrène ischémique de membre a été retenu dans tous les cas. La biologie réalisée était normale. En urgence, il a été réalisé une amputation trans-humérale dans 2 cas et un débridement associé à une amputation de quatre doigts dans un cas. L’évolution a été simple dans tous les cas. La gangrène sèche iatrogène de membre par garrot en milieu hospitalier ne devrait pas se concevoir. Cela passe par la rigueur dans l'administration des soins et une surveillance régulière et attentive des patients. PMID:27217892

  11. A Mathematical Physicist's Approach to Virology

    Science.gov (United States)

    Twarock, Reidun

    2012-02-01

    The following talk has been given in a special session dedicated to Professor Heinz-Dietrich Doebner at QTS in Prague in August 2011 on the occasion of his 80th birthday. It documents my journey from being a PhD student in Mathematical Physics at the Arnold Sommerfeld Institute in Clausthal under his supervision, to becoming a Professor of Mathematical Biology at the University of York in the UK. I am currently heading an interdisciplinary research group of eight PDRAs and PhDs, focussed on investigating the structures of viruses from a symmetry perspective and unravelling the implications of virus structure on how viruses form and infect their hosts. A central element in my research is my fascination with the development and application of symmetry techniques, which stems from my time in Clausthal when working with Professor Doebner and colleagues. I would like to thank Professor Doebner for these important formative years in Clausthal. Der folgende Vortrag war mein Beitrag zu einer Festsitzung fuer Herrn Professor Heinz-Dietrich Doebner auf der Tagung QTS im August 2011 anläßlich seines achzigsten Geburtstags. Dieser Beitrag dokumentiert, wie sich meine Forschungen aus der Zeit als Doktorandin von Herrn Professor Doebner in Mathematischer Physik am Arnold Sommerfeld Institut in Clausthal weiterentwickelt haben, und zu meiner Professur in Mathematischer Biologie an der Universität York geführt haben. Ich leite dort zur Zeit eine interdisziplinäre Forschungsgruppe von acht Postdocs und Doktoranden, die sich mit der Entwicklung und Anwendung von Symmetrie-Techniken in der Virologie beschäftigt, und insbesondere untersucht, wie sich die Symmetrie-Eigenschaften von Viren auf deren Entstehung und Funktionsweise auswirken. Eine wichtige Vorraussetzung für dieses Forschungsprogramm ist meine Faszination für die Modellierung von Symmetrie-Eigenschaften, die ich während meiner Zusammenarbeit mit Herrn Professor Doebner und Kollegen in Clausthal entwickelt habe

  12. Phylogenetic and functional analyses of a plant protein related to human B-cell receptor-associated proteins.

    Science.gov (United States)

    Atabekova, Anastasia K; Pankratenko, Anna V; Makarova, Svetlana S; Lazareva, Ekaterina A; Owens, Robert A; Solovyev, Andrey G; Morozov, Sergey Y

    2017-01-01

    Human B-cell receptor-associated protein BAP31 (HsBAP31) is the endoplasmic reticulum-resident protein involved in protein sorting and transport as well as pro-apoptotic signaling. Plant orthologs of HsBAP31 termed 'plant BAP-like proteins' (PBL proteins) have thus far remained unstudied. Recently, the PBL protein from Nicotiana tabacum (NtPBL) was identified as an interactor of Nt-4/1, a plant protein known to interact with plant virus movement proteins and affect the long-distance transport of potato spindle tuber viroid (PSTVd) via the phloem. Here, we have compared the sequences of PBL proteins and studied the biochemical properties of NtPBL. Analysis of a number of fully sequenced plant genomes revealed that PBL-encoding genes represent a small multigene family with up to six members per genome. Two conserved motifs were identified in the C-terminal region of PBL proteins. The NtPBL C-terminal hydrophilic region (NtPBL-C) was expressed in bacterial cells, purified, and used for analysis of its RNA binding properties in vitro. In gel shift experiments, NtPBL-C was found to bind several tested RNAs, showing the most efficient binding to microRNA precursors (pre-miRNA) and less efficient interaction with PSTVd. Mutational analysis suggested that NtPBL-C has a composite RNA-binding site, with two conserved lysine residues in the most C-terminal protein region being involved in binding of pre-miRNA but not PSTVd RNA. Virus-mediated transient expression of NtPBL-C in plants resulted in stunting and leaf malformation, developmental abnormalities similar to those described previously for blockage of miRNA biogenesis/function. We hypothesize that the NtPBL protein represents a previously undiscovered component of the miRNA pathway. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  13. Pathology, classification, and staging of lung tumors; Pathologie, Klassifikation und Stadieneinteilung boesartiger Lungentumoren

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, K.M.; Wiethege, T. [Institut fuer Pathologie an den Berufsgenossenschaftlichen Kliniken Bergmannsheil der Ruhr-Universitaet Bochum (Germany)

    2004-05-01

    histomorphologische Tumortyp. In den letzten Jahren hat sich unser Wissen um die Biologie boesartiger Lungentumoren durch den Einsatz immunhistochemischer und molekularbiologischer Untersuchungsverfahren wesentlich erweitert. Diese teils aufwaendigen Methoden erlauben z. B. eine verbesserte Differenzialdiagnose und eine qualitative und quantitative Charakterisierung heterogen differenzierter Tumoren. Der Nachweis genetischer Alterationen in Onkogenen oder Tumorsuppressorgenen ist bislang ueberwiegend von wissenschaftlichem Interesse. Die grosse Heterogenitaet boesartiger Lungentumoren kann auch durch ein heterogenes, mit molekularbiologischen Methoden fassbares genetisches Defektmuster der Tumoren dargestellt werden. Ein ueberzeugender wiederkehrender Zusammenhang zwischen genetischem Defektmuster und fuehrendem histomorphologischem Wachstumsmuster konnte bislang nicht aufgezeigt werden. Ein valider Zusammenhang zwischen individuellen Befunden als Basis fuer eine Korrelation zwischen der Operabilitaet, dem Tumorwachstum, dem Ansprechen auf eine Chemotherapie oder der Prognose ist bislang nicht hinreichend untersucht oder gar belegt. (orig.)

  14. Origins and early development of the concept that brown adipose tissue thermogenesis is linked to energy balance and obesity.

    Science.gov (United States)

    Trayhurn, Paul

    2017-03-01

    Brown adipose tissue (BAT) was identified as a thermogenic organ in 1961, and in 1978 shown to be the major site of thermoregulatory non-shivering thermogenesis in rats acclimated to the cold. Investigations in the mid-late 1970s established the uncoupling of oxidative phosphorylation through a proton conductance pathway across the mitochondrial inner membrane as the mechanism for heat production in BAT, this being regulated by UCP1 which was first discovered as a 32,000 Mr cold-inducible protein. These developments came when those concerned with nutritional energetics were proposing that thermogenesis is a significant factor in energy balance and the aetiology of obesity. A link with BAT was first demonstrated in obese ob/ob mice, which were shown to have decreased thermogenic activity in the tissue, and in rats exhibiting diet-induced thermogenesis (DIT) during overfeeding on a cafeteria diet where an activation of brown fat was evident. These pioneering observations led to extensive studies on BAT in different animal models of obesity, both genetic (particularly ob/ob and db/db mice, fa/fa rats) and experimentally-induced. In each case, indices of BAT activity and capacity (mitochondrial content, GDP binding, amount of UCP1) indicated that the tissue plays a role in DIT and that obesity is characterised by reduced thermogenesis. Links between BAT and whole-body energetics were also made in physiological situations such as lactation and fasting. Studies in the 1980s also provided clear evidence for the presence of BAT in adult humans, particularly through the detection of UCP1, and its activation in patients with phaeochromocytoma. Interest in BAT in energetics and obesity waned by the 1990s; the current major renewal of interest has undoubtedly been contingent on the pioneering developments that emerged some 40 years ago. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  15. Phospholipid makeup of the breast adipose tissue is impacted by obesity and mammary cancer in the mouse: Results of a pilot study.

    Science.gov (United States)

    Margolis, Michael; Perez, Osvaldo; Martinez, Mitchell; Santander, Ana M; Mendez, Armando J; Nadji, Mehrdad; Nayer, Ali; Bhattacharya, Sanjoy; Torroella-Kouri, Marta

    2015-01-01

    . Occurrence of triglycerides and free fatty acids will be examined in bAT and similar lipidomic analyses will be carried out visceral adipose tissue, highly inflamed in obesity. Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.

  16. Effets des electrons secondaires sur l'ADN

    Science.gov (United States)

    Boudaiffa, Badia

    Les interactions des electrons de basse energie (EBE) representent un element important en sciences des radiations, particulierement, les sequences se produisant immediatement apres l'interaction de la radiation ionisante avec le milieu biologique. Il est bien connu que lorsque ces radiations deposent leur energie dans la cellule, elles produisent un grand nombre d'electrons secondaires (4 x 104/MeV), qui sont crees le long de la trace avec des energies cinetiques initiales bien inferieures a 20 eV. Cependant, il n'y a jamais eu de mesures directes demontrant l'interaction de ces electrons de tres basse energie avec l'ADN, du principalement aux difficultes experimentales imposees par la complexite du milieu biologique. Dans notre laboratoire, les dernieres annees ont ete consacrees a l'etude des phenomenes fondamentaux induits par impact des EBE sur differentes molecules simples (e.g., N2, CO, O2, H2O, NO, C2H 4, C6H6, C2H12) et quelques molecules complexes dans leur phase solide. D'autres travaux effectues recemment sur des bases de l'ADN et des oligonucleotides ont montre que les EBE produisent des bris moleculaires sur les biomolecules. Ces travaux nous ont permis d'elaborer des techniques pour mettre en evidence et comprendre les interactions fondamentales des EBE avec des molecules d'interet biologique, afin d'atteindre notre objectif majeur d'etudier l'effet direct de ces particules sur la molecule d'ADN. Les techniques de sciences des surfaces developpees et utilisees dans les etudes precitees peuvent etre etendues et combinees avec des methodes classiques de biologie pour etudier les dommages de l'ADN induits par l'impact des EBE. Nos experiences ont montre l'efficacite des electrons de 3--20 eV a induire des coupures simple et double brins dans l'ADN. Pour des energies inferieures a 15 eV, ces coupures sont induites par la localisation temporaire d'un electron sur une unite moleculaire de l'ADN, ce qui engendre la formation d'un ion negatif transitoire

  17. Conséquences industrielles et écologiques de l'introduction de nouvelles espèces dans les hydrosystèmes continentaux : la moule zébrée et autres espèces invasives

    Directory of Open Access Journals (Sweden)

    KHALANSKI M.

    1997-01-01

    Full Text Available Les eaux de surface sont prélevées pour divers usages industriels, parmi lesquels la production d'énergie électrique représente une large part. Dans les circuits d'eau brute se fixent de nombreuses espèces d'organismes aquatiques, qui perturbent le fonctionnement des installations et sont susceptibles d'entraîner l'indisponibilité de certaines d'entre elles. Dans certains cas, l'irruption de nouvelles espèces pose un problème grave à l'industrie. L'introduction de deux espèces de moules zébrées (genre Dreissena dans les Grands Lacs américains, puis leur extension progressive vers le sud des États-Unis au cours des dernières années, se chiffre par un dommage pour l'industrie estimé à cinq milliards de dollars par an en 2000. L'impact écologique de la moule zébrée en Amérique du Nord a fait l'objet de nombreux travaux ; dans la phase d'extension rapide de l'espèce, il semble significatif. En Europe, la moule zébrée constitue aussi une menace pour les circuits industriels ; c'est pourquoi cette espèce a fait l'objet de nombreuses études, notamment en France sur la Seine, le Rhône et la Moselle. Deux nouvelles espèces invasives sont récemment apparues dans les cours d'eau européens : il s'agit du clam asiatique Corbicula fluminea et d'un amphipode : Corophium curvispinum. Elles s'ajoutent à la liste faunistique des organismes observés dans les circuits de centrales thermiques installées sur les cours d'eau français : spongiaires, hydraires, bryozoaires, mollusques. Pour assurer la disponibilité des circuits, il faut pouvoir contrôler le développement de ces espèces ; ce qui implique une connaissance approfondie de leur biologie et de leur écologie. Les méthodes de lutte actuellement mises en oeuvre au plan industriel, ou qui sont à l'étude, sont brièvement passées en revue.

  18. Les collections scientifiques de l’université Bordeaux 1. Sciences et Technologies

    Directory of Open Access Journals (Sweden)

    Jérôme de La Noë

    2012-02-01

    Full Text Available De nombreuses universités scientifiques possèdent des collections. L’université Bordeaux 1 possède neuf grandes collections concernant les domaines de la préhistoire, de l’anthropologie, de la géologie terrestre et marine, de la paléontologie et micropaléontologie, de la biologie, de l’astronomie et d’un fonds ancien et moderne d’ouvrages scientifiques. Certaines collections sont riches de milliers de spécimens : fossiles d’invertébrés, ossements de vertébrés, silex taillés, ossements humains préhistoriques ou historiques, animaux naturalisés, carottes de sédiments, instruments d’astronomie et livres anciens. Ces collections ont été constituées par des privés ou des chercheurs et ont ensuite été léguées à l’université. Il est important d’identifier les collectionneurs et surtout les motivations qui ont guidé leurs choix : recherche, enseignement, passion. Entre histoires personnelles et histoires locales, ce regard sur les collections est aussi une porte ouverte sur l’histoire des Sciences.Most major scientific universities own numerous collections. The Bordeaux 1 University has nine large collections in various scientific fields such as Prehistory, Anthropology, Geology, Oceanography, Palaeontology and Micropalaeontology, Biology, Astronomy and patrimonial and modern scientific books and documentation. Some collections are wealth of thousands of specimens : invertebrate fossils, vertebrate bones, flints, prehistoric and historic human bones, naturalised animals, sediment cores, astronomy instruments et old books. Such collections were built up by private persons, researchers and academics who have bequeathed them to the university. It is quite important to identify all collectors and mainly to understand what were the motives which guided their choices : research, teaching, passion. Between personal and local histories, such a look at university collections is also an open door to history of

  19. Séroprévalence des marqueurs viraux sur les dons du sang au Centre de Transfusion Sanguine, Hôpital Militaire d’Instruction Mohammed V de Rabat

    Science.gov (United States)

    Uwingabiye, Jean; Zahid, Hafidi; Unyendje, Loubet; Hadef, Rachid

    2016-01-01

    Le but de ce travail était de déterminer la prévalence du virus de l’immunodéficience humaine (VIH), du virus de l’hépatite B (VHB) et C (VHC) sur les dons du sang collectés au Centre de transfusion sanguine(CTS) de l’hôpital militaire d’instruction Mohammed V entre 2010 et 2012. Etude rétrospective menée auprès des donneurs de sang militaires âgés de 18 à 50 ans avec prédominance masculine (95%). L’entretien médical pré-don constitue la première barrière de sélection des sujets à risque. Le dépistage biologique était réalisé par technique immuno-enzymatique en milieu liquide utilisant des anticorps et/ou des antigènes. L’ELISA (enzyme linked immuno-sorbent assay) combiné de quatrième génération pour VHC et VIH a été utilisé. La confirmation a été faite en réalisant la même technique en double au CTS et au laboratoire de virologie. Dans notre série de 25661 échantillons testés, la prévalence du VHB était 3,97‰ (n=102), celle de VHC était 2,45 ‰ (n=63), celle de VIH était 0,15 ‰ (n=4). Un seul cas de coïnfection (0,039 ‰) par le VHB et VHC a été noté, aucune association entre VIH-VHB, VIH-VHC ou VHB, VHC et VIH n’a été enregistrée. Les taux faibles de séroprévalence des marqueurs viraux de notre étude montrent l’amélioration des mesures préventives en ce qui concerne la sélection des donneurs et des tests de dépistage. Cette prévalence constatée incite à maintenir l’utilisation du réactif combiné qui est la seule alternative à la biologie moléculaire pour les pays en voie de développement. PMID:28292147

  20. The auto-inhibitory state of Rho guanine nucleotide exchange factor ARHGEF5/TIM can be relieved by targeting its SH3 domain with rationally designed peptide aptamers.

    Science.gov (United States)

    He, Ping; Tan, De-Li; Liu, Hong-Xiang; Lv, Feng-Lin; Wu, Wei

    2015-04-01

    Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Observaciones sobre características, distribución y daños de sinfilidos (Symphyla y otros organismos del suelo en cultivos de piña, Ananas comosus, del Valle

    Directory of Open Access Journals (Sweden)

    Zuluaga C. José Iván

    1988-12-01

    Full Text Available Como en los últimos años los cultivos de piña, Ananas comosus, del Valle, han sido atacados por sinfílifos, clasificados por el Dr. Evert Lindquist como Scutigerella inmaculata, se estudiaron aspectos biológicos, distribución, daños y relaciones con algunos microorganismos. Mediante encuestas e inspecciones al suelo y plantas se verificó su presencia en Palmira, Pradera, Buga, Buga la grande, Sevilla, Dagua y Darién, principales zonas productoras de piña en este departamento. Ensayos en laboratorio demostraron Que S. inmaculata es de hábitos alimenticios saprófagos y/o fitófagos y de esta forma puede producir daños a las raíces de la pila, causando el síntoma de "escoba", enrojecimiento al follaje y debilidad en la planta; también se demostró que 3 sinfílidos/plante producen los síntomas del ataque. El sinfílido se presenta desde semillero, siendo los ataques tempranos los más graves, causando pérdidas en raíces del 66% aproximadamente.Pineapples culture Ananas comosus of Valle, they have been attacked by symphylids last vean (Symphyla, classified by Dr. Evert Lindquist like Scutigerella inmaculata. Biologie aspects, distribution, harms and relationships with some microorganisms some studied in this work. This has a wide distribution on Valle and through surveys and inspections over soil and plants their presance was verified in Palmira, Pradera, Buga; Bugalagrande, Sevilla, Dagua y Darién, the main producer pineapple zones in this department. Laboratory essays showed that this symphilids has saphrophytes and plant eater food habits and by this way could produce harm the pineapples roots causing symptom "broom", foliage getting red color and weakness in plant; also is shown that three symphylids per plant produce tipical symptom of attacking. It is made evident from seed bed being early attacks were more grave causing' root losses about 66% (percent aproximatilly.

  2. Introduction of the HAM-Nat examination--applicants and students admitted to the Medical Faculty in 2012-2014.

    Science.gov (United States)

    Werwick, Katrin; Winkler-Stuck, Kirstin; Hampe, Wolfgang; Albrecht, Peggy; Robra, Bernt-Peter

    2015-01-01

    Hintergrund/Zielsetzung: Die Medizinische Fakultät Magdeburg hat zum Wintersemester 2012/13 einen Wissenstest zur Auswahl ihrer Studienbewerber eingeführt. Das Hamburger Auswahlverfahren für medizinische Studiengänge - Naturwissenschaftsteil (HAM-Nat) umfasst einen Multiple Choice-Test mit Fragen zu medizinisch relevanten Aspekten der Fächer Biologie, Physik, Chemie und Mathematik, der speziell für die Auswahl von Medizinbewerbern entwickelt wurde. Es wird untersucht, wie der HAM-Nat die Studierendenauswahl beeinflusst, aus welchen Gründen sich Studierende im Rahmen des Bewerbungsverfahrens für die Teilnahme am Test entscheiden und welche Erwartungen sie an das Studium haben.Methodik: Die Auswahlverfahren der Hochschule 2011 (ohne HAM-Nat) und 2012-2014 (mit HAM-Nat) werden verglichen. Aufbauend auf den Ergebnissen explorativer Interviews wurden erstmalig Studienanfänger des Wintersemesters 2013/2014 zur Wahl von Studienfach und Studienort sowie zu ihren Erwartungen an das Studium schriftlich befragt. Ergebnisse: Das um den HAM-Nat-Test erweiterte Auswahlverfahren wurde problemlos eingeführt. Der HAM-Nat hatte einen großen Einfluss auf die Auswahlentscheidung. Rund 65% der Zugelassenen hätten bei ausschließlicher Berücksichtigung der Abiturnote keinen Studienplatz erhalten. Männliche Bewerber zeigten im Durchschnitt bessere HAM-Nat-Ergebnisse als weibliche. Den Fragebogen beantworteten 147 von 191 Studienanfängern(77%). Für Studienbewerber aus Sachsen-Anhalt sind Hauptgründe für die Wahl der Landeshauptstadt die regionale Nähe, das vorhandene soziale Umfeld, die guten Studienbedingungen und der Wohlfühlcharakter am Studienort. Für die Mehrzahl der Bewerber, insbesondere für Bewerber aus anderen Bundesländern, standen dagegen die relativ guten Zulassungschancen in Magdeburg im Vordergrund. Schlussfolgerung: Die Medizinische Fakultät Magdeburg sieht im HAM-Nat ein geeignetes Instrument, um Bewerber mit hervorragenden naturwissenschaftlichen

  3. Séroprévalence de l’AgHBs chez la femme enceinte dans le centre du Maroc

    Science.gov (United States)

    Sbiti, Mohammed; Khalki, Hanane; Benbella, Imane; louzi, Lhoussaine

    2016-01-01

    La transmission materno-fœtale du virus de l'hépatite B (VHB) est un problème qui préoccupe toujours les autorités sanitaires à travers le monde et suscite la mise en place de mesures préventives renforcées. Le statut réplicatif du virus chez la mère séropositive, évalué par la positivité de l'AgHbe et le taux de la charge virale, conditionne le risque de contamination qui est plus important en période péri-natale. Les mères porteuses chroniques du VHB constituent un véritable réservoir de la transmission verticale de cette infection. Nous avons étudié, à travers cette enquête sur 1120 femmes enceintes Marocaines, la séroprévalence de l'AgHBs qui était de 2,35%, dans le but d'alimenter les données nationales sur ce sujet. Parmi ces femmes séropositives pour l'AgHBs, 79,1% avaient un AgHBe négatif et ont bénéficié d'une recherche moléculaire qui s'est révélée positive dans 89,4% des cas. La vaccination de la femme en âge de procréer est l'un des piliers majeurs de la prévention de la transmission verticale du VHB, seulement 2,4% de nos patientes étaient vaccinées. Ceci relève l'intérêt du dépistage au cours de la grossesse, qui doit se focaliser sur la sensibilisation à la vaccination de femmes séronégatives, et le suivi par biologie moléculaire des mères séropositives dans le but d'instaurer un traitement prophylactique adéquat. PMID:27795784

  4. Characterization of Two Microbial Isolates from Andean Lakes in Bolivia

    Science.gov (United States)

    Demergasso, C.; Blamey, J.; Escudero, L.; Chong, G.; Casamayor, E. O.; Cabrol, N. A.; Grin, E. A.; Hock, A.; Kiss, A.; Borics, G.

    2004-01-01

    miniprep protocol. The 16S rRNA genes were amplified by PCR using both Bacteria- and Archaeauniversal primer sets: 27f and 1492r, 21f and 1492r respectively. Sequences of 16S rRNA gene were determined and initially compared with reference sequences contained in the EMBL nucleotide sequence database by using the BLAST program and were subsequently aligned with 16S rRNA reference sequences in the ARB package (http://www.mikro.biologie.tu-muenchen.de). Aligned sequences were inserted within a stable phylogenetic tree by using the ARB parsimony tool. In this work we report the morphology and phylogenetic characterization of two isolates belonged to Laguna Blanca sediments.

  5. Quel humanisme pour notre âge bio-technologique ? Which humanism in our bio-technological age ? Anthropology as a necessary horizon for medical anthropology.

    Directory of Open Access Journals (Sweden)

    Gilles Bibeau

    2010-11-01

    Full Text Available Face aux dérives qui touchent de nos jours à la définition même de la vie et de l’humanité, l’auteur invite ses collègues à renouer avec leur fonction de vigilance critique et éthique. L’argument se déploie dans trois directions. Il s’ancre d’abord dans l’étude de l’impact de la biologie moléculaire sur la médecine qui tend à se transformer, pour une part, en une médecine prédictive et qui engendre de nouvelles définitions de la maladie et de la santé. L’auteur plaide, ensuite, pour un renouvellement des modèles culturalistes qui ont prévalu, jusqu’ici, dans l’anthropologie médicale et pour leur application à l’étude des nouvelles pathologies (surpoids, obésité, par exemple qui caractérisent nos sociétés d’abondance. Enfin, il propose un virage de notre discipline en direction des études portant sur l’inégalité sociale, dans une ouverture au politique, à l’éthique et aux questions de justice sociale et d’équité. La prise en compte de ce triple horizon permettra, selon l’auteur, à l’anthropologie médicale de contribuer à construire un nouvel humanisme ajusté à notre âge.In this essay, the author invites his anthropological colleagues to develop their function of critical and ethical vigilance, particularly in regard to recent developments in molecular biology. His argument follows three paths. Firstly, he examines a number of ways through which genomics and proteomics impact on the clinical practice in creating a powerful predictive medicine that leads to new definitions of disease and health. Secondly, he argues that medical anthropologists should upgrade and make more complex their classical culturalist models in order to better explore the many layers of factors involved in the genesis of the new prevalent pathologies such as overweight and obesity. Thirdly, he proposes a turn in the practice of medical anthropology that should become more concerned by questions of

  6. The anti-tumour activity of rLj-RGD4, an RGD toxin protein from Lampetra japonica, on human laryngeal squamous carcinoma Hep-2 cells in nude mice.

    Science.gov (United States)

    Shao, Fangyu; Lv, Mei; Zheng, Yuanyuan; Jiang, Junshu; Wang, Yue; Lv, Li; Wang, Jihong

    2015-12-01

    indicate that the recombinant RGD toxin protein rLj-RGD4 may serve as a potent clinical therapy for human laryngeal squamous carcinoma. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  7. Alcohol-induced histone H3K9 hyperacetylation and cardiac hypertrophy are reversed by a histone acetylases inhibitor anacardic acid in developing murine hearts.

    Science.gov (United States)

    Peng, Chang; Zhang, Weihua; Zhao, Weian; Zhu, Jing; Huang, Xupei; Tian, Jie

    2015-06-01

    The expression of cardiac genes is precisely regulated, and any perturbation may cause developmental defects. In a previous study, we demonstrated that alcohol consumption during pregnancy could lead to uncontrolled expressions of cardiac genes and eventually result in cardiac dysplasia. However, the underlying mechanisms remain unclear. In the present study, we have investigated the alcohol-induced cardiac hypertrophy and its potential mechanisms. Furthermore, the protective effect of anacardic acid against the alcohol-induced cardiac hypertrophy has been explored in experimental mice. C57BL/6 pregnant mice were gavaged with 56% ethanol or saline and the hearts of their fetus were collected for analysis. Binding of p300, CBP, PCAF, SRC1, except GCN5, were increased to the NKX2.5 promoter in fetal mouse hearts exposed to alcohol. Increased acetylation of H3K9 and increased mRNA expression of NKX2.5, β-MHC and Cx43 were observed in the same samples. Treatment with a pan-acetylase inhibitor, anacardic acid, reduced the binding affinity of p300 and PCAF to the NKX2.5, β-MHC, Cx43 promoters and attenuated H3K9 hyperacetylation. Interestingly, anacardic acid down-regulated over-expression of these cardiac genes induced by alcohol and ultimately attenuated ethanol-induced cardiac hypertrophy in fetal mice. Our results indicate that alcohol exposure during pregnancy could lead to fetal cardiac hypertrophy. The over-expression of NKX2.5, β-MHC, Cx43 mediated by p300 and PCAF may be critical mechanisms of alcohol-induced cardiac hypertrophy. Anacardic acid can down-regulate the over-expression of cardiac genes and reverse cardiac hypertrophy caused by alcohol treatment in pregnant mice, suggesting it could be a potential therapeutic agent for the treatment of cardiac hypertrophy. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Atherosclerosis and atherosensitivity in two southwest Algerian desert rodents, Psammomys obesus and Gerbillus gerbillus, and in Rattus norvegicus

    Directory of Open Access Journals (Sweden)

    El-Aoufi S

    2012-09-01

    Full Text Available Salima El-Aoufi,1 Mohamed-Amine Lazourgui,1 Lakhdar Griene,2 Boubekeur Maouche31Laboratoire de Biologie et de Physiologie des Organismes/MMDED, Faculté des Sciences Biologiques, USTHB, El-Alia, Dar El Beida, Algeria; 2Laboratoire d'Hormonologie, Centre Pierre et Marie Curie, C.H.U Mustapha, Algeria; 3Laboratoire de Physicochimie Théorique et Chimie Informatique, Faculté de Chimie, USTHB, El-Alia, Dar El Beida, AlgeriaAbstract: Cardiovascular disease, including atherosclerosis, is the leading cause of death in patients with diabetes worldwide; thus, it is a major medical concern. The endothelium contributes to the control of many vascular functions, and clinical observations show that it is a primary target for diabetic syndrome. To get better insight into the mechanisms underlying atherosclerosis, we studied the interspecific differences in the arterial metabolisms of two, Psammomys obesus and Gerbillus gerbillus, as well as Rattus norvegicus (Wistar rat, well known for its atheroresistance. Twenty-two enzymatic activities and six macromolecular substances were histochemically compared in the two desert species and in Wistar aortas (abdominal and thoracic and arteries (femoral and caudal embedded in a common block. In the healthy adult rodents, enzyme activities were very intense. They demonstrated that aortic myocytes are capable of various synthesis and catabolism processes. However, considering the frequency of atherosclerosis and its phenotypes, significant differences appeared between the species studied. Our comparative study shows that aortic atherosensitive animals have several common metabolic characteristics, which are found in Psammomys rich in metachromatic glycosaminoglycans (involved in the inhibition of lipolysis and in calcification of the organic matrix, reduced activity in enzymes related to the Krebs cycle (weakening energetic power, and low lipolytic enzyme, adenosine triphosphatase, and adenosine diphosphatase activities

  9. A Report on the Implementation of the Blooming Biology Tool: Aligning Course Learning Outcomes with Assessments and Promoting Consistency in a Large Multi-Section First-Year Biology Course

    Directory of Open Access Journals (Sweden)

    Carol Pollock

    2010-06-01

    Full Text Available The objectives of this study were to investigate the alignment of exam questions with course learning outcomes in a first year biology majors course, to examine gaps and overlaps in assessment of content amongst the sections of the course, and to use this information to provide feedback to the teaching team to further improve the course. Our ultimate goal was to provide students with learning outcomes that would clearly indicate the content and the level at which they would be expected to learn the content for this course, regardless of the section in which they were registered. We took an evidence-based approach to course evaluation and employed the Blooming Biology Tool to compare the learning outcomes and the exam questions of the course, investigating whether the cognitive skill level of each learning outcome as written matched the level at which it was assessed. We identified misalignments and recommended revising the learning outcomes to better reflect the intended level of learning for the course. We also investigated student performance on exam questions of different cognitive levels and found that students scored statistically significantly higher (p < .05 on questions in which learning outcomes were tested at the stated cognitive skill level compared to at a higher level.Les objectifs de cette étude étaient (1 d’examiner la correspondance entre les questions d’examen et les résultats en matière d’apprentissage pour un cours de première année d’une majeure en biologie, (2 d’étudier les écarts et les chevauchements en matière d’évaluation du contenu des sections du cours et (3 d’utiliser ces informations pour fournir de la rétroaction à l’équipe des enseignants afin d’améliorer le cours. Notre but ultime était de faire en sorte que les résultats de l’apprentissage des étudiants indiquent clairement le contenu à apprendre et le niveau cognitif qu’ils devraient avoir atteint, peu

  10. The effect of histone deacetylase inhibitor trichostatin A on porcine mesenchymal stem cell transcriptome.

    Science.gov (United States)

    Gurgul, Artur; Opiela, Jolanta; Pawlina, Klaudia; Szmatoła, Tomasz; Bochenek, Michał; Bugno-Poniewierska, Monika

    2017-08-01

    expression level of majority of genes affected by TSA is restored to the initial level. Nonetheless, the set of about six hundred genes responsible for e.g. adhesion, signal transduction and cell communication was altered even after 55-72 h of culture without TSA. TSA also enhanced expression of some of pluripotency marker genes (FGF2, LIF, TERT) but their expression was stabilized during further culture without TSA. The detailed analysis of factors connected with neuron-like differentiation allowed us to assume that TSA mostly stimulates neurogenic differentiation pathway in the pig MSCs possibly through interaction with Wnt-mediated signaling and thus triggers mechanisms conducive to epigenetic reprograming. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  11. Openings: the Act of Modelizing and the Question of Complexity

    Directory of Open Access Journals (Sweden)

    Emilie Janton

    2010-02-01

    Full Text Available Richard Powers’ novels are commonly associated with “systems novels” as Tom LeClair first described them, notably because of the constant compositional use the novelist makes of different extra-textual systems (including various fields such as biology, computer science, or more extensively chaos theory.To what extent do those modelized systems, apparently meant to supply structuring tools to readers keen for interpretive keys, contribute to the novels’ inner complexity, and how does their installation in the texts take place? The way I have chosen to address this issue is to look into the openings of the novels as privileged locations where formal guidelines are provided. Focusing on the openings helps point out functional variations in the use of models, which appear to be essential to the continuous development of complexity throughout the texts. The openings therefore seem not only to have programmatic virtues, but also to offer disorienting elements whose impact on the global scale (that is that of the novel as a whole forces us to reconsider the scope of the models at stake in Richard Powers’ writing.Les romans de Richard Powers sont souvent associés aux « romans systémiques » tels que Tom LeClair a pu les décrire, et ce notamment en raison de l’usage répété que le romancier fait, dans la composition de ses textes, de divers systèmes extra-textuels (dont la biologie, l’informatique et, plus largement, la théorie du chaos.Dans quelle mesure ces systèmes modélisés, apparemment destinés à donner aux lecteurs avides de clés interprétatives des outils propres à dégager des structures, participent-ils de la complexité interne des romans, et comment ces systèmes sont-ils mis en place dans les textes ? Le présent article aborde ces questions en analysant l’ouverture de plusieurs romans, lieu privilégié de l’instauration de lignes de force structurelles. L’étude de ces ouvertures permet de mettre en

  12. Compte rendu du Congrès National du Pétrole, Vichy, 13-16 mai 1981 Report on the 9th French Petroleum Congress in Vichy, 13-16 May 1981

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    Bertrand A. R. V.

    2006-11-01

    Full Text Available Le 9e Congrès National du Pétrole (Vichy, 13-16 mai 1981 s'est déroulé dans un contexte assez difficile (importantes augmentations des prix pétroliers au cours des dernières années, crise mondiale du secteur raffinage, incertitudes politiques. . . bien reflété par le thème choisi Les techniciens français du pétrole face au défi énergétique. Comportant trois tables rondes générales qui fournissaient à l'ensemble des participants, quelles que soient leur spécialité, l'occasion de travailler en commun et ont ainsi donné à cette manifestation un caractère pluridisciplinaire particulièrement studieux, le congrès a mis l'accent sur un certain nombre de nécessités déjà mises en évidence : - diversifier les sources d'hydrocarbures à tous les niveaux (géographique, nature du produit . . . ; - recourir à d'autres sources d'énergie et en particulier à l'énergie nucléaire ; - utiliser toutes les techniques de pointe disponibles (informatique, robotique, biologie, . . . et accroître le capital matière grise, en particulier pour permettre l'exploitation du pétrole difficile (récupération assistée, gisements marins sous grande profondeur d'eau, huiles lourdes, . . . ; - former les hommes en conséquence et attirer de nombreux jeunes compétents et imaginatifs, vers l'industrie des hydrocarbures (pétrole et gaz naturel, et vers les compagnies énergétiques. The 9th French National Petroleurn Congress (Vichy, 13-16 May 1981 took place in a rather difficult context (substantial rises in oil prices in recent years, world crisis in the refining sector, political uncertainties, etc. which was effectively reflected in the theme chosen - French petroleum technicians faced with the energy challenge. There were three round-table discussions which provided all the participants - whatever their specialization - with an opportunity to meet and work together, and gave the meeting a particularly multidisciplinary and studious

  13. 双价抗蛇毒鸡卵黄抗体制备与生物活性研究%Preparation anti biological activity of bivalent IgY against cobra anti viper venom

    Institute of Scientific and Technical Information of China (English)

    祁俊华; 孔天翰

    2009-01-01

    Objective To prepare the bivalent immunoglobulin yolk (lgY) against eobra and viper venom and to detect its activities as the foundation for production and application of polyvalent . Methods The venom of Naja atra Cantor and Daboia russellii siamensis injected alternately into the leghorn hen. Biva-lent lgY was extraeted by water dilution. The biological activity of bivalent lgY were deteeted in several as-pects, sueh as the potency ( by indireet ELISA assay), the cross immunity ( by double immunodiffusion), the membrane lysis activity ( by experiments of vitelline membrane lysis) and 50% lethal activity ( LD50 ). Results Bivalent IgY was extracted from eggs yolk in 28-42 days after the first immunization. The titers of bivalent lgY against cobra and viper venom were 1:12 800 and 1: 6400. The cross immunologic reactions of bivalent IgY were found obviously with six kinds of snake venoms from Elapinae and Viperinae. There were not immunologic precipitation lines between bivalent IgY and four kinds of snake venoms from Crotalinae. Bi- valent lgY obviously deereased the vitelline membrane lysis activity of cobra and viper venom and prolonged the average survival time of mice with cobra or viper envenomation (P < 0.05). Moreover, with the same dose of bivalent IgY, the survival rate of mice with cobra venom envenomation was higher than those with vi-per venom envenomation. Conclusion Bivalent lgY could signifieantly neutralize biologieal activities of co-bra and viper venom, protect animals with cobra or viper envenomation.%目的 通过双价抗蛇毒鸡卵黄抗体(bivalent anti-snake venom immunoglobulin yolk,双价IgY)的制备及其相关特性研究,为多价抗蛇毒IgY的制备和应用奠定基础.方法 两种单一抗原(舟山眼镜蛇、圆斑蝰泰国亚种)按顺序依次交替注入单只鸡体内,水稀释法制备双价IgY;测定双价IgY效价(间接ELISA法)、交叉免疫特性(双向免疫扩散试验)及对溶膜活性(溶膜试验)、半数

  14. Direct sequencing for rapid detection of multidrug resistant Mycobacterium tuberculosis strains in Morocco

    Directory of Open Access Journals (Sweden)

    Zakham F

    2013-11-01

    Full Text Available Fathiah Zakham,1,4 Imane Chaoui,1 Amina Hadbae Echchaoui,2 Fouad Chetioui,3 My Driss Elmessaoudi,3 My Mustapha Ennaji,4 Mohammed Abid,2 Mohammed El Mzibri11Unité de Biologie et Recherché Médicale, Centre National de l'Energie, des Sciences et des Techniques Nucléaires (CNESTEN, Rabat, 2Laboratoire de Génétique Mycobacterienne, Institut Pasteur, Tangier, 3Laboratoire de Tuberculose Institut Pasteur, Casablanca, 4Laboratoire de Microbiologie, Hygiène et Virologie, Faculté des Sciences et Techniques, Mohammedia, MoroccoBackground: Tuberculosis (TB is a major public health problem with high mortality and morbidity rates, especially in low-income countries. Disturbingly, the emergence of multidrug resistant (MDR and extensively drug resistant (XDR TB cases has worsened the situation, raising concerns of a future epidemic of virtually untreatable TB. Indeed, the rapid diagnosis of MDR TB is a critical issue for TB management. This study is an attempt to establish a rapid diagnosis of MDR TB by sequencing the target fragments of the rpoB gene which linked to resistance against rifampicin and the katG gene and inhA promoter region, which are associated with resistance to isoniazid.Methods: For this purpose, 133 sputum samples of TB patients from Morocco were enrolled in this study. One hundred samples were collected from new cases, and the remaining 33 were from previously treated patients (drug relapse or failure, chronic cases and did not respond to anti-TB drugs after a sufficient duration of treatment. All samples were subjected to rpoB, katG and pinhA mutation analysis by polymerase chain reaction and DNA sequencing.Results: Molecular analysis showed that seven strains were isoniazid-monoresistant and 17 were rifampicin-monoresistant. MDR TB strains were identified in nine cases (6.8%. Among them, eight were traditionally diagnosed as critical cases, comprising four chronic and four drug-relapse cases. The last strain was isolated from a

  15. Mechanistic insights into the inhibitory effects of palmitoylation on cytosolic thioredoxin reductase and thioredoxin.

    Science.gov (United States)

    Qin, Huijun; Liang, Wei; Xu, Zhiyu; Ye, Fei; Li, Xiaoming; Zhong, Liangwei

    2015-03-01

    the TrxR1 active site selenol/thiol group(s) from palmitoylation. Our data suggest that Se/S-palmitoylation acts as an important modulator of TrxR1/hTrx1 activities, representing a novel potential mechanism that underlies overnutrition-induced events. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  16. Foundation Skills for Scientists: An Evolving Program

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    Elaine Khoo

    2010-06-01

    Full Text Available We have undertaken an integrated and collaborative approach to developing foundational skills of students in a first year, Introductory Biology course. The course is a large lecture and laboratory course with enrollments ranging from 800-1000 per year. Teaching and Learning experts were brought into the course as weekly ‘Foundation Skills for Scientists’ sessions were created. The initial challenges were to have effective knowledge exchange between collaborators and create an integrated course syllabus. Once effective sessions were created, the next challenge was to improve student valuation of them. High value was only achieved when the skill sessions were tightly linked to course assignments and activities and was delivered ‘just in time’. Even then, the challenge has been to motivate students to realize that the sessions are directly relevant to them. Overall, student performance has improved since the program was initiated as measured by rate of retention in the course, overall course marks and quality of writing.Nous avons utilisé une approche intégrée et collaborative pour approfondir les compétences de base des étudiants de première année qui suivent un cours d’introduction à la biologie. Il s’agit d’un cours magistral et en laboratoire, auquel s’inscrivent entre 800 et 1000 étudiants par an. Ce cours a bénéficié de l’apport d’experts en enseignement et en apprentissage afin d’appuyer le développement de séances hebdomadaires portant sur les compétences de base en sciences. Les difficultés initiales étaient de susciter un échange de connaissances efficace entre les collaborateurs et de créer un plan de cours intégré. Une fois les séances organisées, la difficulté suivante a été de faire en sorte que les étudiants les apprécient davantage. Ces derniers les ont jugées très utiles uniquement lorsqu’elles étaient étroitement liées aux tâches et aux

  17. Etude exploratoire des conceptions de la circulation sanguine aupres d'eleves de l'ordre collegial

    Science.gov (United States)

    Robitaille, Jean-Marc

    Il existe peu d'etudes sur les conceptions touchant les domaines de la biologie, notamment sur les conceptions de la circulation sanguine Nous avons observe egalement l'absence de recherche menee aupres d'eleves de l'ordre collegial sur cette question. Nous avons voulu combler une lacune en menant une recherche sur les conceptions de la circulation sanguine aupres d'eleves de l'ordre collegial. Pour mener cette recherche nous nous sommes inspires d'une methode developpee par Treagust (1988). Le premier niveau de formulation didactique etablit l'architecture du systeme et la fonction nutritive de la circulation. Le second niveau de formulation didactique decrit et relie les parametres de la dynamique de la circulation et leur relation: Pression, Debit et Resistance. Le troisieme niveau de formulation didactique s'interesse au controle de la circulation du sang dans un contexte d'homeostasie qui implique la regulation de la pression arterielle. Nous avons construit un questionnaire en nous guidant sur les niveaux de formulation didactique et l'analyse des entrevues menees aupres de dix-huit eleves, representatifs de la population cible. Ce questionnaire fut administre a un echantillon de 2300 eleves disperses dans six colleges de la region de Montreal. Notre echantillon comprend des eleves inscrits a des programmes de l'ordre collegial en Sciences de la nature et en Techniques de la sante et qui n'ont pas suivi le cours sur la circulation sanguine. Notre analyse des reponses des eleves de notre echantillon aux questions sur le premier niveau de formulation didactique revele que la majorite des eleves considerent que le systeme circulatoire relie les organes les uns aux autres dans un circuit en serie. Notre analyse revele egalement que la majorite des eleves estiment que les nutriments sont extraits du sang par les organes selon un processus de selection base sur les besoins determines par la fonction de l'organe. Ces besoins sont differents selon les organes qui ne

  18. 德国科普期刊综览与评析%Studies on Popular Scientific Magazines in Germany

    Institute of Scientific and Technical Information of China (English)

    吴限; 谭文华

    2015-01-01

    德国当前出版的科普期刊包括综合类、分科类和研究学会期刊三大类型。综合类科普期刊有《科学画刊》、《奇奥》、《P.M.知识世界》、《科学万象》、《科技评论》、《奇妙世界》、《知识奇境》、《听·知识》、《知识奇观》和《知识》。分科类科普期刊主要有《当代化学》、《当代生物》、《当代物理》、《星星和太空》、《太空》、《星际》、《大脑与智力》、《今日心理学》、《自然》和《国家地理·德国》。四大研究学会(马克斯-普朗克学会,夫琅和费学会,亥姆霍茨学会和莱布尼茨学会)出版的期刊分别为《马克斯-普朗克研究》、《前沿》、《亥姆霍茨展望》和《莱布尼茨杂志》。德国科普期刊具有创刊历史不长、外观强化品牌、新刊名称单调、重视少儿读者、大量使用图片、本土进口并行、科研机构参与和忽视化学题材等特点,可谓长处与短处并存。中国期刊应从中择其优点,以弥补自己的不足,而对于其存在的缺点,则不应盲目跟从。%Popular scientific magazines in Germany are divided into three categories:comprehensive,subject-oriented and research society journals. The comprehensive magazines are Bild der Wissenschaft, GEO, P.M. Welt des Wissens, Spektrum der Wissenschaft, Technology Review, Welt der Wunder, Wunderwelt Wissen, H rzu Wissen, Wissen &Staunen and Wissen. Subject-oriented magazines include Chemie in unserer Zeit, Biologie in unserer Zeit, Physik in unserer Zeit,Sterne und Weltraum,Spcace,Interstellarum,Gehirn und Geist,Psychologie Heute,Natur and National .. o Geographic Deutschland. Research society journals MaxPlanckForschung,weiter.vorn,Helmholtz Perspektiven and Leibniz-Journal are published from the Max Plank Society, the Fraunhofer Society, the Helmholtz Association and the Leibniz Association, respectively. Typical features of the German popular

  19. Les activités de conservation des lémuriens par le Groupe d’Etude et de Recherche sur les Primates de Madagascar (GERP Conservation activities of lemurs by the Madagascar Primate Research Group (GERP- Groupe d’Etude et de Recherche sur les Primates de Madagascar

    Directory of Open Access Journals (Sweden)

    Rose Marie Randrianarison

    2011-10-01

    Full Text Available Le Groupe d’Etude et de Recherche sur les Primates de Madagascar, une association de conservation, a été créée en 1994 grâce à l’initiative des Enseignants Chercheurs et étudiants du Département de Paléontologie et d’Anthropologie Biologique et du Département de Biologie Animale de l’Université d’Antananarivo. Le GERP regroupe actuellement des membres scientifiques multidisciplinaires Malgaches et étrangers dont la majorité d’entre eux est constituée par des primatologues. Les principales actions du GERP se focalisent sur les travaux de recherche sur les Primates Prosimiens de Madagascar, l’établissement de leur plan de conservation, la découverte de nouvelles espèces de lémuriens, la translocation et le transfert des lémuriens vivant dans des milieux défrichés ou précaires, le suivi et l’abondance des lémuriens ainsi que la révision de leurs aires de distribution. Les résultats des recherches effectuées sur la conservation ont permis de publier des articles dans des revues de renommée nationale et internationale sur la Primatologie. En outre, le renforcement de capacité et l’éducation de la communauté de base, des systèmes éducatifs primaires et supérieurs sur la conservation des lémuriens et l’appui aux activités de développement durable de la population locale s’avèrent nécessaires pour que la conservation des lémuriens soit pérenne.The Madagascar Primate Research Group (GERP - Groupe d’Etude et de Recherche sur les Primates de Madagascar is a conservation-focused association created in 1994 by the initiative of researcher lecturers and students from the Department of Paleontology and Biological Anthropology and the Department of Animal Biology of the University of Antananarivo. The GERP membership consists of multidisciplinary scientists, both Malagasy and foreign, the majority of whom are primatologists. The principle actions of the association are focused on research on the

  20. Etudes physiques des mélanges eau-cryoprotecteurs

    Science.gov (United States)

    Vassoille, R.; Perez, J.

    The aim of the following review is to present the most important studies concerning the physical properties of water-solutes mixtures used in cryobiology. Cryobiology is a branch of biology which deals with the very low temperature behaviour of cells. This technique is developed today in several directions. The creation of banks of cells and perhaps in a short time of small organs, is the purpose of much research in this domain. Before freezing, living cells are generally put in a solution containing one or more solutes. The role of these solutes is to protect the cells against damage due to crystallization of water (cryoprotectors). The mechanisms of cryoprotection are not well known ; nevertheless the vitreous state formation during cooling is often invoked. So, it is possible to avoid crystallization damage such as mechanical strain (due to an increase of volume of about 10 %) and salt effects (due to osmotic pressure). The conditions in which the vitreous state is obtained, maintained during cooling, storage at low temperature and rewarming can be defined by physical studies presented in the following review. Le présent travail est essentiellement une revue bibliographique des principales études physiques qui ont été réalisées avec des solutions de composés habituellement employés en cryobiologie. La cryobiologie est une branche de la biologie qui s'intéresse au comportement des cellules à basse température. Cette discipline est actuellement en plein développement dans des domaines très divers. Son principal but est la création de banques de cellules de plus en plus complexes avec comme perspective la conservation des organes. Les cellules vivantes sont généralement placées avant congélation dans une solution contenant divers composés dont le rôle est de protéger les cellules contre les effets de la cristallisation de l'eau. L'action protectrice de ces cryoprotecteurs est encore mal connue; cependant, la formation d'un état vitreux lors du

  1. Limestone cliff - face and cave use by wild ring-tailed lemurs (Lemur catta in southwestern Madagascar

    Directory of Open Access Journals (Sweden)

    Michelle L. Sauther

    2013-11-01

    Full Text Available Ring-tailed lemurs live in a range of habitats in southwestern Madagascar. To date, much of the knowledge of ring-tailed lemur ecology, biology and behavior come from riverine gallery forests sites. Recent years have seen an expansion of comprehensive research on this resilient species, including areas of limestone spiny forest along Madagascar’s southwestern coast. This work is documenting newly discovered behaviors by this species. The regular use of cliff-faces and embedded crevices and caves by ring-tailed lemurs in southwestern Madagascar are reported here. Cave use by several anthropoid primates has been explained as a thermoregulatory behavior. It is suggested that cliff-face and cave use by these ring-tailed lemurs serves several purposes, including resource acquisition, thermoregulation, and as an anti-predator avoidance strategy in the absence of suitable large sleeping trees. Observations indicate that the limestone boundaries of the Mahafaly Plateau and their associated xerophytic scrub forests warrant further conserva­tion attention, given the presence of behavioral variation and increasing threats to this endangered primate species. RÉSUMÉLemur catta occupe divers habitats dans le Sud-ouest de Madagascar. L’écologie, la biologie et le comportement de Lemur catta sont actuellement mieux connus des populations vivant dans les forêts riveraines et les zones environnantes. Pour mieux comprendre cette espèce de lémurien, les recherches ont été étendues à d’autres habitats dont les forêts épineuses du plateau calcaire qui est situé le long du littoral Sud-ouest de Madagascar. Dans cette étude nous rapportons les comportements récemment découverts de Lemur catta qui utilise les falaises et les grottes dans le Sud-ouest de Madagascar. L’utilisation des grottes par la plupart des primates hominoïdes est liée à un avantage thermorégulateur offert par ce milieu. Dans notre cas, l’exploitation de falaises et de

  2. Dilatation aigue de l'estomac: à propos de 02 cas et revue de la literature

    Science.gov (United States)

    Touré, Alpha Oumar; Thiam, Ousmane; Cisée, Mamadou; Nduwimana, Diomede; Gueye, Mohamadou Lamine; Seck, Mamadou; Ka, Ousmane; Dieng, Madieng; Touré, Cheikh Tidiane

    2015-01-01

    La dilatation aiguë de l'estomac est une pathologie rare. Elle est classiquement observée en psychiatrie dans les troubles du comportement alimentaire. Le diagnostic préopératoire est difficile et fait appel à la radiologie. La mortalité liée aux complications varie entre 80% et 100%. Nous rapportons 2cas de dilatation aiguë de l'estomac prises en charge au service de Chirurgie Générale de l'Hôpital Aristide Le Dantec de Dakar dont l'une était compliquée de nécrose et l'autre d'une rupture gastrique. Il s'agissait de 2 patients dont l'un était de sexe masculin âgé de 32 ans et l'autre de sexe féminin âgée de 36 ans. Ils étaient reçus dans un tableau de douleurs abdominales aiguës et un état de collapsus cardiovasculaire. L'examen avait retrouvé un syndrome d'irritation péritonéale chez les 2 patients. A la biologie, on notait une anémie chez tous les patients. A la radiographie de l'abdomen sans préparation, on notait un pneumopéritoine massif chez le patient et un gros niveau hydro-aérique chez la patiente. Le diagnostic préopératoire était une péritonite par perforation d'organe creux chez le patient et une occlusion intestinale aiguë chez la patiente. Après une réanimation, la laparotomie avait permis de retrouver une dilatation énorme de l'estomac avec une large rupture au niveau de la petite courbure chez le patient et une dilatation importante de l'estomac avec une nécrose du fundus chez la patiente. Une suture de la petite courbure était réalisée chez le patient et une gastrectomie atypique fundique chez la patiente. Les suites opératoires étaient marquées par un décès chez le patient au deuxième jour post-opératoire et une sténose gastrique chez la patiente nécessitant une gastrectomie totale.La dilatation aiguë de l'estomac est une pathologie rare. Son diagnostic aux urgences est difficile car les signes ne sont pas spécifiques. Les formes compliquées donnent un tableau d'abdomen chirurgical aigu. L

  3. Entrevue guidée avec Karen Messing

    Directory of Open Access Journals (Sweden)

    Ana-Maria Seifert

    2009-02-01

    Full Text Available Karen Messing nous a accordé une entrevue pour la rubrique des Défricheurs de PISTES de la revue. Dans son cas nous devons plutôt parler d’une défricheuse de pistes. En effet, tout au long de sa vie professionnelle elle s’est intéressée aux particularités reliées à la question du genre dans le travail et plus particulièrement au travail des femmes et à ses conséquences sur leur santé. Elle était professeure à l’Université du Québec à Montréal, elle vient tout juste de prendre sa retraite « officielle ». Elle est détentrice d’un doctorat en biologie et elle s’est graduellement intéressée à la question de l’environnement de travail et à ses effets sur la santé des personnes. Au début des années 90, elle est allée se perfectionner en ergonomie afin de se doter d’outils d’analyse du travail. Ses recherches ont porté sur plusieurs métiers (préposés aux bénéficiaires, préposés au nettoyage, caissières, etc.. Karen Messing a publié plusieurs livres et articles scientifiques sur la question qui sont importants. Nous vous invitons à la connaître un peu mieux.Karen Messing granted us an interview for the magazine’s Défricheurs de PISTES section. In her case, she is a groundbreaker. In fact, throughout her professional life, she has been interested in the specific issues related to the subject of gender in work, and particularly to women’s work and its impacts on their health. She was a professor at the Université du Québec à Montréal, and has just begun her “official” retirement. She has a doctorate in biology and gradually became interested in the subject of the work environment and its effects on people’s health. In the early 1990s, she refined her skills in ergonomics in order to have the necessary work analysis tools. Her research has investigated several professions (orderlies, cleaning workers, cashiers, etc.. Karen Messing has published several important scientific books and

  4. Diffusion variétale du palmier à huile (Elaeis guineensis Jacq.

    Directory of Open Access Journals (Sweden)

    Durand-Gasselin Tristan

    2000-03-01

    érique latine. Le progrès génétique disponible en expérimentation doit être intégré dans les semences vulgarisées au plus vite et en quantité suffisante. Cependant, pour la reproduction du meilleur matériel, il existe des contraintes liées à la biologie des semences qui compliquent et ralentissent cette vulgarisation. En raison d’une dormance difficile à lever, les semences de palmier à huile sont distribuées sous forme de graines germées et leur distribution demande une organisation particulière.

  5. Avant-Propos

    Science.gov (United States)

    Ollivier, J.; Farhi, E.; Ferrand, M.; Benoit, M.

    2005-11-01

    L'École Thématique “Neutrons et Biologie” s'est tenue du 22 au 26 Mai 2004 à Praz/Arly (Haute-Savoie, France), dans le cadre des 12 èmes Journees de la Diffusion Neutronique de la Societe Française de Neutronique. Cette école a ete organisee avec le concours financier du CNRS (formation permanente), du Laboratoire Léon Brillouin (CEA Saclay), de la region Rhône-Alpes, du conseil général de Haute-Savoie et de l'Université Joseph Fourier de Grenoble. Une cinquantaine de participants, dont une vingtaine d'intervenants, ont largement contribué à la réussite de l'École. D'un point de vue scientifique, l'École s'est déclinée en sept sessions thématiques majeures: - une première session introductive a été consacrée à une revue globale des méthodes biophysiques ayant un fort impact pour l'étude de la structure et de la dynamique des macromolécules biologiques (J. Parello). Un accent tout particulier à été apporté pour décrire les neutrons en tant que composante importante de la panoplie des techniques couramment utilisées en biophysique moléculaire (J. Schweitzer). - une session dédiée aux mesures dynamiques par diffusion incohérente de neutrons a été largement developpée. Qu'ils s'agissent de vibrations et de relaxations moléculaires dans les protéines (J.M. Zanotti), de dynamique globale des protéines (G. Zaccaï), ainsi que de dynamique de l'eau d'hydratation (F. Gabel), de nombreux exemples ont permis d'illustrer la pertinence des neutrons pour étudier la dynamique fonctionnelle des protéines sur l'échelle de temps picosecond nanoseconde. L'analyse des données de diffusion inélastique de neutrons ne peut se passer de modélisation théorique analytique des propriétés dynamique des biomolécules (D. Bicout). - une large place avait été réservée aux études structurales en biologie. Cette troisième session a rassemblé des contributions en diffusion aux petits angles de neutrons pour l'étude structurale en

  6. Préface

    Science.gov (United States)

    Ouerdane, Youcef; Laporte, Pierre

    2005-06-01

    L'objectif de la série de colloques UVX est de réunir, au rythme d'une fois tous les deux ans, les scientifiques et industriels travaillant dans le domaine du développement des sources de photon de grande énergie (UV, VUV, et X) et de leurs applications. En particulier cette manifestation est l'occasion de faire se rencontrer une communauté très pluridisciplinaire (physique, chimie, biologie, sciences de l'univers) liée à des domaines en forte évolution technologique (lasers et rayonnement synchrotron notamment). Le colloque UVX 2004 s'est tenu au Palais des Congrès de Saint-Étienne (42000) du 7 au 11 juin 2004. La période écoulée depuis l'édition précédente (Oléron 2002) a été particulièrement active dans tous les domaines concernés : grands projets de sources, méthodes de diagnostic au sens large. Une nouvelle fois on constate que le bref et l'ultra-bref ont une place privilégiée, qu'il s'agisse du travail sur les accélérateurs ou sur les lasers qui, bien sûr, dans la course aux temps courts remportent la palme avec la présence de spécialistes du domaine attoseconde. La communauté représentée a la chance d'être en prise directe avec de très grands projets en phase active de réalisation comme le Laser Megajoule (LMJ), la source SOLEIL, et un projet d'ampleur plus modeste mais remarquable dans son domaine : la source LASERIX d'Orsay/Palaiseau. On pourra citer aussi le projet Arc en Ciel qui, lui, est encore au stade de sa définition. - SOLEIL, source de nouvelle génération de rayonnement synchrotron (plateau de Saclay) est dans une phase active de réalisation : achèvement de l'infrastructure en 2005 et injection du 1o faisceau dans l'anneau de stockage prévu également en 2005. Cette source devrait être la meilleure au monde dans le domaine VUV/X mous, tout en restant très polyvalente (brillance, accordabilité, structure temporelle, polarisation) et complémentaire de l'ESRF. Au final on disposera de 21 lignes de lumi

  7. Los vertebrados del Neogeno de la Costa Sur del Perú: ambiente sedimentario y condiciones de fosilización

    Directory of Open Access Journals (Sweden)

    1988-01-01

    Full Text Available Les fossiles de vertébrés marins sont très abondants dans les Formations Pisco et Caballas de la côte sud du Pérou [sélaciens, téléostéens, reptiles, oiseaux, mammifères (cétacés, carnivores, édentés]. Ces fossiles ont contribué à l'établissement d'une stratigraphie car ils se répartissent en sept niveaux (six dans la Formation Pisco, un dans la Formation Caballas dont l'âge va du Miocène inférieur jusqu'au sommet du Pliocène inférieur. Les vertébrés, en général, montrent un état de conservation exceptionnel les squelettes complets ou subcomplets sont très courants. L'étude sédimentologique et paléontologique (taphonomie, biologie montre que les vertébrés se sont déposés en milieu de plage. Trois types de condition de bord de mer ont été définis: • plages abritées, où se forment des lumachelles à coquilles peu brisées, parfois en position de vie. Les squelettes sont généralement complets et en connexion ou bien légèrement dissociés • plages agitées à lumachelle de coquilles brisées et os isolés • récifs où les coquilles et les os sont toujours brisés. Les niveaux à vertébrés ne montrent pas de structures tidales de flux et de reflux, ce qui semble indiquer que les marées étaient de faible amplitude. Le milieu de dépôt, peu profond (de 0 à 5 m, correspond aux zones supra et intertidales. L'existence de nombreux squelettes en connexion est la preuve d'un ensablement très rapide des cadavres (quelques jours qui semble être dû plus à l'action des vagues qu'au taux de sédimentation. Dans le second cas, les squelettes auraient été dissociés par les prédateurs. La biologie des baleines (qui se reproduisent, en général, près de la côte, celle des abondants carnivores et des oiseaux (qui sont strictement dépendants de la côte pour leur reproduction confirment le milieu de bord de mer. Par ailleurs, l'édenté de la Formation Pisco est un animal qui ne pouvait pas nager (ou

  8. Debilitat de la teoria de l'educació: sobre la narrativitat científica de l'educació Weakness in the Educational Theory: On Scientific Narrative in Education Debilidad de la teoría de la educación: sobre la narratividad científica de la educación

    Directory of Open Access Journals (Sweden)

    Conrad Vilanou i Torrano

    2008-01-01

    Full Text Available En aquest assaig es revisen les aportacions que el professor Antoni J. Colom ha fet a la teoria de l'educació en els últims anys. Es dibuixa, per tant, un itinerari que es troba representat per diferents moments: debilitat constitutiva de la teoria de l'educació; crisi del model de la física newtoniana; construcció científica de l'educació a partir de la biologia i del mètode experimental, fins arribar a la teoria del caos que així constitueix una nova narrativa científica per a la pedagogia. Es tracta en definitiva, d'una proposta alternativa que a la dècada dels anys noranta va sorgir amb força als Estats Units i que vol superar la visió lineal i simple del fenomen educatiu com una mera relació de causa-efecte. En el seu lloc, es proposa una nova narrativa basada en la complexitat de la teoria del caos que així pot servir per explicar la teoria i la pràctica educatives, bo i establint alts nivells de coherència entre ambdós estadis -el teòric i el pràctic- perquè, en darrer terme, la narrativa educativa ha de ser sempre congerent amb l'educació narrada. _____________________________________________________________________________________________________________________________________________________________________________________ Cet essai permet de réviser les contributions que le professeur Antoni J. Colom a faites à la théorie de l'éducation au cours de ces dernières années. Un itinéraire est dessiné qui est représenté par différents moments: faiblesse constitutive de la théorie de l'éducation; crise du modèle de la physique newtonienne; construction scientifique de l'éducation à partir de la biologie et de la méthode expérimentale, jusque'à parvenir à la théorie du chaos qui constitue ainsi une nouvelle narration scientifique pour la pédagogie. Il s'agit, en définitive, d'une proposition alternative qui a surgi avec force aux États-Unis, dans la décennie des années 90, et qui veut d

  9. French research in the field of nuclear agronomy; Les recherches francaises en agronomie nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Guerin De Montgareuil, P. [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1964-07-01

    'amidon, metabolisme glucidique des tubercules irradies, radioresistance des levures). Le dossier des techniques nucleaires est surtout represente par les radioisotopes (carbone 14, phosphore 32, soufre 35, calcium 45, potassium 42, cuivre 64, or 198) et les isotopes stables analyses au spectrometre de masse (azote 15, oxygene 18) ou par activation aux neutrons (bore 10). Les travaux mentionnes se rapportent a des questions de niveau tres variable en physiologie vegetale, agrologie, entomologie agricole et zootechnie. On cite egalement les resultats obtenus a propos des mesures de l'humidite (thermalisation neutronique) et de la densite (diffusion gamma) d'un sol. A ces differentes recherches prennent part, chacun selon sa vocation propre, de nombreux organismes: entreprise privee a caractere cooperatif, firmes industrielles, laboratoires universitaires, instituts scientifiques. A cette occasion, se trouve precise le role du Commissariat a l'Energie Atomique: d'une part, information et soutien, d'autre part, prise en charge des aspects specifiquement nucleaires. Son intervention dans ce domaine s'est recemment traduite par la creation, au sein du Departement de Biologie, d'une Section de Radioagronomie dont on decrit les objectifs ainsi que les moyens mis a sa disposition au Centre d'Etudes Nucleaires de Cadarache. (auteur)

  10. Quelle posture les sciences sociales doivent-elles adopter vis-à-vis des sciences de la vie ?

    Directory of Open Access Journals (Sweden)

    Dominique Guillo

    2012-05-01

    Full Text Available Pour Albert Ogien et Louis Quéré, les sciences sociales sont séparées des sciences de la vie par une frontière quasi-infranchissable. Par conséquent, selon eux, l’évocation de vues empruntées à la biologie en sociologie et en anthropologie serait, au mieux, dépourvue d’intérêt, au pire fallacieuse. Ils développent cette thèse en invoquant, notamment, la non-falsifiabilité des sciences sociales par les sciences de la vie, le poids du social et de l’environnement dans la cognition et l’action humaines, ou encore l’irréductibilité des objets respectifs de ces disciplines. Nier l’existence d’une telle frontière impliquerait, à leurs yeux, la dissolution des sciences sociales dans les sciences de la nature. Certains arguments invoqués à l’appui de ces thèses valent pour réfuter certaines formes sommaires de naturalisme. Toutefois, ils n’invalident pas les variantes comme celles que proposent Laurence Kaufmann et Laurent Cordonier. Contrairement à ce que suggèrent ces arguments, on peut fort bien défendre le principe d’une autonomie épistémologique des sciences sociales, tout en contestant l’existence d’une frontière nette entre disciplines. Par ailleurs, l’hypothèse de la frontière fragilise les sciences sociales, en les conduisant à ignorer un champ de recherche dans lequel elles ont pourtant vocation à intervenir : celui de l’articulation des connaissances qu’elles accumulent, de manière indépendante et au moyen de leurs propres méthodes, avec celles que recueillent, de leur côté, les sciences de la vie. Ce faisant, elles laissent prospérer dans ce champ le naturalisme le plus sommaire.Which Position Should Social Sciences Adopt Towards Life Sciences? A Border or a ForeshoreFor Albert Ogien and Louis Quéré, social sciences are separated from life sciences by an almost uncrossable border. Therefore, they argue that the evocation of views borrowed from biology in sociology and

  11. Tsidy, Repahaka sy Fotsife: 15 years research on nocturnal lemurs in the Ankarafantsika National Park, Madagascar Tsidy, Repahaka sy Fotsife :15 ans de recherche sur les lémuriens nocturnes dans le Parc National d´Ankarafantsika, Madagascar

    Directory of Open Access Journals (Sweden)

    Marine Joly

    2011-10-01

    és locales d'Antananarivo, Mahajanga ainsi que Madagascar National Parks (autorité chargée de gérer les aires protégées de l´île. Le projet a débuté en 1996. Son but est d´améliorer les connaissances sur l´évolution et l´adaptation d´un groupe de primates souvent négligé, les lémuriens nocturnes, et de contribuer à leur conservation. Pour cela, les chercheurs ont mené de nombreuses études sur la diversité, l´écologie, la communication, la sociobiologie des lémuriens nocturnes dans cette région. Après avoir fait la découverte d´une nouvelle espèce de microcèbe (Microcebus ravelobensis, les chercheurs ont également caractérisé la morphologie, la génétique, l´écologie, la communication ainsi que les aspects sociaux et récemment les capacités cognitives des espèces sympatriques les plus petites (taille de souris ; Microcebus murinus et M. ravelobensis et de taille moyenne (taille d´un petit chat ; Lepilemur edwardsi et Avahi occidentalis présentes dans la région. Les principaux résultats de cette collaboration étroite entre les institutions européenne et malgaches sont présentés dans ce chapitre. Ils montrent l´importance d´un échange d´expérience, de l´éducation des étudiants malgaches et des assistants de terrain ainsi que d´un travail commun avec les partenaires malgaches afin de contribuer à l´acquisition des connaissances sur la biologie des espèces endémiques. Ces connaissances sont essentielles pour établir des plans de gestion efficaces et contribuer ainsi à la conservation des espèces menacées.

  12. Marine hydrogeology: recent accomplishments and future opportunities

    Science.gov (United States)

    Fisher, A. T.

    2005-03-01

    l'estimation des propriétés à la sub-surface des fonds marins, et des travaux complémentaires ont mis en valeur les mesures de flux, local ou global, de termes « sources » et « pertes », et des liens quantitatifs entre l'hydrogéologie, la chimie, la tectonique, la biologie, et les processus géophysiques. Cet article vise à résumer des résultats sélectionnés parmi un petit nombre d'études, et à décrire plusieurs nouvelles expériences et programmes, qui sont autant d'opportunités pour répondre aux questions fondamentales relatives aux fonds marins, posées ces dernières 20-30 années. La hidrogeología marina es una disciplina científica de amplios alcances que involucra la exploración de interacciones fluido-roca por debajo del fondo del mar. Se han llevado a cabo estudios en centros de expansión del fondo del mar, lugares en medio de una placa, y en ambientes de placa y margen continental. Aunque muchos sitios en el fondo del mar son remotos, existen aspectos de estos sistemas marinos que los hacen particularmente adaptables para análisis hidrológico. Nuevas técnicas y herramientas desarrolladas, y el establecimiento de varios programas multidisciplinarios para exploración oceanográfica, han ayudado a impulsar la hidrogeología marina hacia delante durante las ultimas décadas. La mayor parte del trabajo hidrogeológico marino se ha enfocado en la medición o estimación de propiedades hidrogeológicas dentro del subsuelo superficial, pero trabajo adicionalha enfatizado mediciones de flujos globales y locales, términos de fuente y sumidero de fluidos, y vínculos cuantitativos entre procesos hidrogeológicos, químicos, tectónicos, biológicos y geofísicos. Además de resumir resultados seleccionados de un número pequeño de estudios de caso, este artículo incluye una descripción de varios programas y experimentos nuevos que aportarán oportunidades excepcionales para dirigir preguntas hidrogeológicas fundamentales dentro del

  13. BILAN DES ACTIONS DU PLAN MIGRATEURS CONCERNANT L’ALOSE FEINTE (ALOSA FALLAX RHODANENSIS SUR LE BASSIN RHÔNE-MÉDITERRANÉE-CORSE.

    Directory of Open Access Journals (Sweden)

    LEBEL I.

    2001-07-01

    Full Text Available La mise en place du premier volet du plan migrateurs Rhône-Méditerranée a nécessité tout un ensemble de travaux d’aménagement et d’ingénierie pour améliorer la libre circulation des poissons dans la zone concernée. Cet ensemble d’interventions a été accompagné d’études pour suivre ou optimiser les travaux d’aménagement, ainsi que de mesures réglementaires. Sur le Rhône et ses affluents, les trois écluses de navigation de Vallabrègues, d’Avignon et de Caderousse ont été aménagées pour permettre la réalisation d’éclusées réservées spécialement au passage des poissons tandis que de nombreux seuils ont été modifiés ou équipés pour favoriser leur franchissement par les aloses. L’ensemble des études a permis d’abord d’améliorer les connaissances sur la taxinomie, la biologie et l’écologie de l’alose feinte du Rhône. Les résultats ont ainsi mis en évidence une sous-espèce endémique qui renforce l’intérêt d’un programme de restauration des stocks dans une optique de maintien de la biodiversité. Le suivi de la pêcherie amateur aux engins a permis de préciser la fenêtre optimale de migration des aloses, et les facteurs influant sur la remontée de reproduction des adultes. Les résultats des campagnes de comptages visuels et d’échosondage ont montré l’efficacité globale des éclusées à poissons en tant que système de franchissement de l’ouvrage. Seul le comptage visuel permettrait d’évaluer le nombre de poissons franchissant l’obstacle, tout en restant assujetti à des contraintes techniques et à des imprécisions inhérentes à cette technique. Enfin, l’étude récente de la pêche sportive par carnets de pêche s’avère particulièrement utile dans une analyse qualitative de l’extension de la zone colonisée par les aloses, qui a incontestablement augmenté ces sept dernières années. En 1998, un bilan scientifique des actions et études menées depuis

  14. GENOMIQUE ET PRODUCTION NON ALIMENTAIRE Acides gras d’intérêt industriel obtenus par génie génétique

    Directory of Open Access Journals (Sweden)

    Lessire René

    2002-03-01

    Full Text Available La caractérisation de mutants de plantes déficients pour la synthèse de lipides, l’évolution des techniques de la biologie moléculaire et le séquençage de la totalité du génome d’Arabidopsis thaliana sont des éléments qui ont rendu possible la manipulation par voie génétique de la composition en acides gras des huiles végétales. Parmi les enzymes impliquées dans la synthèse des acides gras et des triacylglycérols, les acyl-ACP thioestérases, les désaturases, les hydroxylases, les transacylases et les élongases sont des protéines stratégiques pour la modification du profil des acides gras des huiles végétales. Il est effectivement possible de diminuer la longueur moyenne de la chaîne carbonée des acides gras de colza par l’introduction du gène codant pour l’acyl-ACP thioestérase de la baie de Californie. L’huile issue de colza génétiquement modifié présente un taux de 50% en C12. Ce taux a été fortement augmenté par croisement avec une variété modifiée par le gène codant pour la lyso-acide phosphatidique acyltransférase (LPAAT de noix de coco. L’introduction ou la suppression d’une insaturation dans la chaîne carbonée d’un acide gras a également été réalisée. La transformation par le gène anti-sens de la stéaroyl-ACP désaturase a permis de créer des variétés de colza dont l’acide gras majoritaire est le C18:0. De même, des variétés de soja produisant de l’huile enrichie en acide oléique ou linolénique ont été obtenues respectivement par inactivation des gènes des DELTA12 et DELTA15 désaturases. La position de l’insaturation peut être également modifiée. Une huile riche en acide pétrosélinique (C18:1, DELTA6 résulte de l’introduction du gène de la palmitoyl-ACP DELTA4 désaturase de coriandre et de la stéaroyl-ACP DELTA9 désaturase en anti-sens. Enfin, de l’huile de colza riche en acides polyinsaturés a été obtenue par croisement de colza modifi

  15. Faut-il faire la sociologie des singes ?

    Directory of Open Access Journals (Sweden)

    Véronique Servais

    2012-05-01

    Full Text Available En prenant appui sur des exemples empruntés à l’éthologie sociale, ce texte apporte trois arguments au débat sur la naturalisation du social. Le premier met en question la notion de compétence sociale innée en insistant sur la nécessité de préciser « ce qui » est (ou pourrait être inné dans une compétence sociale. Le deuxième montre que la négligence de la dimension affective des interactions et de la communication animale a pour conséquence de placer dans les esprits animaux des « délibérations » ou des « calculs » qui sont d’abord une propriété de la communication affective. Le troisième examine quelques travaux récents sur la coopération chez les primates et conclut qu’ici aussi, les biologistes oublient qu’une grande partie des compétences sociales qu’ils situent dans les individus relèvent en fait de la situation. Après avoir ainsi exposé les limites et les impasses de la biologie dans l’explication du social, y compris dans le monde animal, le texte propose que les sciences sociales investissent empiriquement ce champs laissé en friche, celui de l’articulation entre le biologique et le social. Elles pourraient ainsi contribuer à mieux circonscrire « ce qui » est inné et, donc, à limiter objectivement les ambitions évolutionnistes sur le social.Should we do Sociology of Monkeys?Drawing its examples from the field of ethology and primatology, this paper brings three points to the debate on the naturalization in sociology. The first one insists on the importance of telling apart what is innate and what is not in the “innate social abilities” that are hypothesized by Kaufmann & Cordonier. The second one shows that when scientists see the animal communication as purely informative, they miss the fact that animals are first of all real beings engaged in affective interactions. They consequently wrongfully end up with animals that “calculate” or “make choices”. The third

  16. La sociologie peut-elle ignorer la phylogenèse de l'esprit  ?

    Directory of Open Access Journals (Sweden)

    Joëlle Proust

    2012-01-01

    Full Text Available Cet article examine les raisons avancées par Albert Ogien et Louis Quéré pour rejeter le naturalisme social, c'est-à-dire le projet métathéorique consistant à intégrer les savoirs sur le social issus de la biologie évolutionnaire et des sciences cognitives aux travaux menés en sciences sociales. Face aux arguments d'Albert Ogien portant sur l'irréductibilité de fait et de droit du social relativement au cognitif, il est objecté que les travaux pertinents provenant des sciences cognitives dans leur état actuel devraient être pris en compte et que l'irréductibilité de droit introduit un dualisme dans les sciences sociales qu'il est difficile de justifier. En outre, la distinction de l'épistémique et du cognitif est placée au fondement de l'irréductibilité, mais la nécessité impérative de la coordination sociale pour la sensibilité normative épistémique n'est pas établie de manière concluante. Face aux objections de Louis Quéré concernant l'emploi équivoque, en sciences cognitives, du concept de concept (dont l'acception riche détermine la spécificité de la sociologie, on peut répondre que les concepts maigres (non accompagnés par une analyse de ce qui fait concept sont utilisés non seulement par des organismes dépourvus de pensée propositionnelle, mais figurent aussi dans le répertoire associatif et évaluatif des humains, qu'il s'agisse de l'évaluation de leur propres capacités, ou de celle de la confiance que méritent leurs partenaires.May sociologoly be unaware of mind’s phylogenesis?This article discusses the arguments that Albert Ogien and Louis Quéré direct against social naturalism, i.e. the metatheoretical project of integrating the empirical evidence and theoretical considerations from evolutionary biology and the cognitive sciences to the social sciences. Albert Ogien defends a de facto and a de jure irreducibility of social to cognitive properties. It is objected that the integrative

  17. Al Profesor J. Hernando Ordóñez con ocasión de su posesión como Miembro Honorario de la Academia Nacional de Medicina

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    Hernando Groot Liévano

    2004-03-01

    Sociedad llegó a constituirse en un poderoso impulsor de varias de las ciencias básicas a mediados del siglo XX, a tal punto que muchos de sus integrantes, además de haber incrementado significativamente su producción científica creyeron necesario organizar sociedades especializadas ya en entomología o en antropología o en botánica, lo mismo que en diversas ramas de la medicina. Si bien las actividades de la Sociedad de Biología decayeron a partir de 1959, tal situación debe entenderse como el fenómeno natural de una madre nutricia que desfallece al dar a luz múltiples productos que en forma independiente siguen sus ideales y principios.

    Y qué no decir de las otras contribuciones a la ciencia y a la medicina que se deben recordar, no por desconocidas, sino porque tienen la importancia que hoy quiere destacar la Academia al otorgar la máxima distinción al doctor Ordóñez. En cuanto a investigaciones, la primera y muy notable, el hallazgo de una nueva modalidad de la contracción muscular, la prosténica, sobre la cual nos hablará más tarde, hallazgo que hizo cuando apenas cursaba el tercer año de medicina, trabajando a la usanza de la época, como preparador del laboratorio de fisiología, cargo al cual se llegaba por riguroso concurso entre los estudiantes.

    Otras muestras de sus investigaciones fueron los estudios sobre resistencia del sistema nervioso central a la anoxia, el hallazgo de un nuevo tipo de melanosis, la melanosis de Ordóñez registrada así en el Diccionario de Jablonsky, los problemas de salud enalturas y sus numerosas publicaciones las más sobre distintos aspectos de las enfermedades cardiovasculares, aparecidas tanto en revistas locales como en aquellas de reconocida importancia internacional por ejemplo Comptes Rendu des Séances de le Societé de Biologie y los Archives des Maladies du Coeur. Sería imposible detallarlas todas.

    Su labor docente, que debe señalarse como una de las más fructíferas, se desarroll

  18. Knowledge in adolescent girls and boys related to physically active and healthy lifestyle [Vědomosti adolescentních děvčat a chlapců vztahující se k pohybově aktivnímu a zdravému životnímu stylu

    Directory of Open Access Journals (Sweden)

    Wojciech Wąsowicz

    2012-03-01

    kurikulárních požadavků (zejména tělesné výchovy a biologie. Hlubší osvojování vědomostí o zdravém životním stylu vyžaduje integrovaný mezipředmětový přístup a efektivnější propojení osvojování vědomostí o pohybové aktivitě, stravování a dalších zdravotně preventivních opatřeních s životním stylem děvčat a chlapců.

  19. Comprehensive test in school physical education at secondary schools in the Czech Republic – Standardization and verification [Vědomostní test ve školní tělesné výchově na středních školách v ČR – Standardizace a verifikace

    Directory of Open Access Journals (Sweden)

    Karel Frömel

    2010-12-01

    éna oblast biologie člověka, výživy a znalostí z oblasti tělesné výchovy a sportu, a tak standardizovat vědomostní test o problematice zdraví a pohybové aktivity v českých podmínkách. Dílčím cílem je pak porovnat výsledky vědomostního testu z hlediska typu škol, tříd a pohlaví. METODIKA: Pro zjišťování vědomostí o problematice zdraví a PA byl sestaven vědomostní test, který byl předložen žákům na 10 středních školách v České republice (dvě odborné školy a osm gymnázií. Získali jsme vyplněné testy od 192 studentů a 224 studentek (15–19 let, kteří je vyplňovali dvakrát: jako pre-test a po pětitýdenní pauze jako post-test v letech 2008–2009. Celkem bylo shromážděno 832 testů. VÝSLEDKY: Koeficient reliability metodou půlení testů byl zjištěn rtt = 0,527 (p < 0,01. Cronbachovo alpha vnitřní konzistence bylo r = 0,627. Chlapci ani děvčata nedosahují 50 % správných odpovědí na otázky vědomostního testu. V pre-testu nebyl zjištěn žádný rozdíl mezi pohlavími; v post-testu byl zjištěn významný rozdíl, který byl také potvrzen koeficientem "effect size" (d = 0,35. Gymnaziální studenti (d = 0,87 a studenti vyšších ročníků (d = 0,47 mají větší znalosti o problematice zdraví a PA než studenti středních odborných škol a prvních ročníků. ZÁVĚRY: Vědomostní test je využitelný zejména pro výzkumné účely, komparaci a jako součást rozsáhlejšího výzkumného šetření. Studenti gymnázií a starší studenti dosahovali lepších výsledků v testu než studenti středních škol a nižších ročníků; mezi pohlavím nebyly zjištěny žádné rozdíly. Praktické použití vědomostního testu by mohlo vést žáky a studenty k zamyšlení se nad vlastním životním stylem. Pro změny pohybového chování by pak bylo vhodné více zainteresovat žáky a využít např. monitorování PA krokoměrem.

  20. Foreword

    Science.gov (United States)

    Boutron, Claude; Ferrari, Christophe

    2003-05-01

    Informatique, Biologie et Médecine, et Sciences de la Terre et de l'Univers. Il y a deux grandes Universités Scientifiques de renommée internationale: l'Université Joseph Fourier (UJF) et l'Institut National Polytechnique de Grenoble (INPG). Il y a aussi d'importants laboratoires de différents organismes publics français et européen comme le Commissariat à l'Énergie Atomique (CEA), le Centre National de la Recherche Scientifique (CNRS), l'Institut Laue Langevin (ILL), l'European Synchrotron Radiation Facility (ESRF) et l'Institut de Radio-Astronomie Millimètrique (IRAM). C'est aussi le lieu d'implantation de nombreuses sociétés de haute technologie comme Hewlett Packard, ST Microelectronics, Schneider Electric and SGS-Thomson. Il a à Grenoble une longue tradition de recherches dans le domaine des métaux lourds dans l'environnement, notamment au Laboratoire de Glaciologie et Géophysique de l'Environnement et au Laboratoire de Géophysique Interne et Tectonophysique. Ces deux volumes regroupent les articles issus de communication présentées aussi bien au cours des sessions orales que des sessions posters. Ces articles sont classés selon l'ordre alphabétique du nom de famille du premier auteur. Nous remercions vivement les auteurs pour l'excellente qualité de ces articles. Nous remercions aussi tout particulièrement Isabelle Houlbert et Laurence Castagné pour leur collaboration. Nous aimerions aussi remercier les membres du comité d'organisation ainsi que Jerome Nriagu (organisateur de la 11e conférence) pour l'aide apportée à l'organisation de cette conférence. Nous remercions aussi tout spécialement Christine Echevet qui n'a pas ménagé ses efforts pour faire de cette conférence un succés, ainsi que de nombreux collègues du Laboratoire de Glaciologie et Géophysique de l'Environnement, en particulier Jocelyne Roquemora. Nous tenons également à remercier le Président de Grenoble Alpes Métropole et le Maire de la Ville de Grenoble pour leur

  1. Critical reflections on evolutionism as a scientific or pseudo-scientific theory and as an atheist ideology

    Directory of Open Access Journals (Sweden)

    Josef Seifert

    2014-03-01

    schlichtweg dazu unfähig sind, die Entstehung irgendeiner neuen Art mit deren erstaunlicher Ordnung und Fülle an sinnvollen Formen, Teilen und Funktionen zu erklären. Zudem bekennt sie intelligente Ursachen der „Evolution“ (im nicht-darwinistischen Sinne des Begriffs und trans-spezifischer Übergänge, die nur durch nicht-Darwinsche Prinzipien oder Ursachen, etwa durch „Entelechien“ oder die rationes seminales im Sinne Augustins, erfolgen würden. Wenn alle diese „Regeln einer begrenzten Evolutionstheorie“ eingehalten und überdies Evolution nur innerhalb von Pflanzen oder Tieren, oder besser nur innerhalb bestimmter Gattungen und Arten von Lebewesen des Pflanzen- oder Tierreichs (etwa Insekten, Säugetieren, katzenartigen, hundeartigen Tieren, etc. angenommen wird, gibt es keine absolut zwingenden rein philosophischen Einwände gegen die Möglichkeit einer solchen partiellen Evolution. Dabei bleiben jedoch so viele Ungereimtheiten bestehen, wenn man eine Evolution von Bakterien bis zu Elefanten, die aus der gleichen Zellenurmutter entstanden sein sollen, annimmt, daß man aus vielen empirischen (und philosophischen Gründen es für äußerst unwahrscheinlich halten muß, daß auch nur innerhalb desselben Reichs, etwa der Tiere, eine nahtlose oder auch nur eine weitgehende Evolution stattgefunden haben soll. (Dagegen sprechen die grundlegenden Unterschiede der Wesensformen und unzählige „Missing Links“ und „Sprünge“ zwischen den Arten. Zumindest ist auch eine solche, und selbst eine ganz eingeschränkte, Evolutionstheorie absolut nicht „bewiesen“. Mit anderen Worten, auch diese einzige möglicherweise wahre begrenzte Evolutionstheorie ist Science Fiction, extrem unwahrscheinlich und jedenfalls absolut nicht „bewiesen“, weshalb jede Schule, Universität, Fakultät und jedes Institut für Biologie auf der ganzen Welt nicht nur das Recht haben sollte, eine Lehre von „intelligent Design“ oder Schöpfung neben Evolution zu unterrichten, sondern

  2. Considérations ontogénétiques et phylogénétiques concernant l’origine de la parole Ontogenetic and phylogenetic considerations concerning the origin of speech

    Directory of Open Access Journals (Sweden)

    Jean Granat

    2011-10-01

    Full Text Available La fin du XXe et le tout début de ce siècle révèlent une véritable réarticulation des recherches dans le domaine de l’émergence de la parole et du langage. Le naturalisme, qui est au centre de cette approche, se propose de décrire les relations entre la biologie (au sens très large du terme d’une part, la parole et le langage, d’autre part, par une accumulation d’hypothèses, de données et de preuves formulées et établies grâce à de multiples collaborations interdisciplinaires. Comme pour les travaux sur l’origine de l’Homme (la découverte d’un nouveau fossile entraînant souvent une remise en question des théories précédentes, on assiste à un foisonnement théorique qui entraîne parfois des développements très hypothétiques, s’appuyant sur des résultats fragiles et sur trop peu de données, proposés dans des disciplines connexes mais non maîtrisées ou trop simplifiées. C’est pourquoi les bilans réguliers, les mises en perspectives critiques ne nous semblent pas superflus.Dans un premier temps nous proposerons une classification qui permet une lecture des différentes théories proposées depuis un demi-siècle (théorie push-pull. Dans l’état actuel des connaissances, il n’est pas possible d’inférer quand nos ancêtres, voire nos lointains ont acquis la faculté de langage et de parole : le contrôle des articulateurs, la coordination entre le larynx et le conduit vocal, la phonologie, la syntaxe, la sémantique et la récursivité. Parmi les questions qui se posent, il en est une qui reste sans réponse : pourquoi notre espèce est actuellement la seule à posséder langue et parole ? De nombreuses questions font partie des problèmes mal posés, comme le sont les questions du type: Quelle(s langue(s parlaient nos prédécesseurs ? Possédaient-ils une langue unique ? En effet, on ne dispose pas (pour le moment de suffisamment de données pour pouvoir y répondre. Peut-être même que

  3. Préface

    Science.gov (United States)

    Paulus, Werner; Meinnel, Jean

    2003-02-01

    En 1994, l'attribution du prix Nobel à Cliff Shull et Bert Brockhouse pour leurs travaux de pionniers pendant les années 50, concernant tant la diffusion élastique des neutrons que la diffusion inélastique, a été la reconnaissance éclatante de l'importance de la diffusion neutronique pour toute la communauté scientifique.Le grand intérêt du neutron pour la recherche s'appuie principalement sur ses propriétés physiques particulières :- les neutrons utilisés pour la caractérisation de la matière (et fournis en relativement grandes quantités par les réacteurs ou les sources à spallation) disposent de longueurs d'onde et d'énergies correspondant directement aux distances interatomiques et aux énergies d'agitation de la matière. Ainsi, par diffusion neutronique, on peut étudier en même temps la structure et le comportement dynamique de la matière ;- le fait que le neutron soit doué d'un moment magnétique lui permet d'interagir avec tout atome porteur d'un moment magnétique. Ceci permet de caractériser intimement le comportement magnétique de la matière à l'échelle microscopique ;- la possibilité de pouvoir varier facilement le contraste d'un même élément en utilisant ses différents isotopes fait du neutron un outil irremplaçable en chimie et physique du solide ainsi qu'en biologie et matière molle ;- enfin, n'ayant pas de charge électrique, les neutrons peuvent pénétrer la matière sans être absorbés significativement, ce qui rend possible une caractérisation non destructive des contraintes et textures sur de grosses pièces des matériaux.Toutes les qualités des neutrons mentionnées ci-dessus permettent de comprendre l'importance de la diffusion neutronique pour des domaines très nombreux et très différents à la fois en recherche fondamentale mais aussi pour des applications industrielles. L'utilisation de l'outil-neutron demande toutefois non seulement une bonne connaissance des différents mécanismes d

  4. Heavy Element Staining of Sedimentary Organic Matter Functional Groups for Backscattered Electron Imaging Marquage par éléments lourds de la matière organique sédimentaire pour la microscopie électronique en électrons rétrodiffusés

    Directory of Open Access Journals (Sweden)

    Belin-Geindre S.

    2006-11-01

    , 1992. Son imagerie est basée sur les contrastes de numéro atomique (Z existant entre les divers constituants. La matière organique apparaît noire et les minéraux gris. Cependant il n'est pas possible de distinguer plusieurs types de matière organique avec le MEB/ER. Afin de mettre en évidence des contrastes au MEB/ER entre différentes matières organiques, les échantillons ont été marqués par des éléments lourds qui ont la particularité de se fixer de manière sélective et spécifique sur les groupes fonctionnels. Cette méthode est largement employée par la biologie cellulaire pour révéler divers corps organiques (Soligo et Lambertenghi-Deliliers, 1987; Langsdorff et al. , 1990; Clark, 1991; Namimatsu, 1992 ou bien par la science des matériaux dans le domaine des polymères (Sawyer et Grubb, 1987; Ohlsson et Törnell, 1990; Sue et al. , 1991; Janik et al. , 1992. L'application à la géologie et à la pétrographie est restée jusqu'à présent assez réduite : sédiments argileux (Whitlatch et Johnson, 1974; Green et al. , 1979; Bishop et al. , 1992; Hillier et Clayton, 1992, charbons (Corcoran et Stephens, 1987; Sommerfeld et al. , 1992, sols (Foster, 1981. Les éléments lourds utilisés pour le marquage sont très variés et présentent une spécificité plus ou moins large (Reynolds, 1963; Lewis et Knight, 1976; Takeuchi et Takeuchi, 1990. La matière organique sédimentaire est un mélange complexe de macromolécules dont la composition dépend de la nature de la matière organique originelle et de son degré d'évolution (Tissot et Welte, 1984. La matière organique peu évoluée possède de nombreuses variétés de groupes fonctionnels (Rouxhet et al. , 1980; Béhar et Vandenbroucke, 1987. La faisabilité de la méthode a d'abord été testée sur des polymères contenant des fonctions chimiques susceptibles d'exister dans les kérogènes naturels (tableau 1. Puis elle a été appliquée à des sédiments presque exclusivement formés de