Gap

Distribution by Scientific Domains

Kinds of Gap

  • air gap
  • air-bone gap
  • anion gap
  • apparent gap
  • band gap
  • bone gap
  • canopy gap
  • capacitive gap
  • communication gap
  • considerable gap
  • critical gap
  • data gap
  • direct band gap
  • energy band gap
  • energy gap
  • existing gap
  • forest gap
  • fundamental gap
  • gender gap
  • gender pay gap
  • gender wage gap
  • geographical gap
  • important gap
  • indirect band gap
  • information gap
  • knowledge gap
  • large gap
  • lumo gap
  • major gap
  • many gap
  • marginal gap
  • miscibility gap
  • narrow gap
  • nerve gap
  • optical band gap
  • output gap
  • pay gap
  • performance gap
  • photonic band gap
  • policy gap
  • poverty gap
  • practice gap
  • productivity gap
  • research gap
  • research-to-practice gap
  • resource gap
  • several gap
  • significant gap
  • small gap
  • spectral gap
  • substantial gap
  • technological gap
  • temporal gap
  • time gap
  • treatment gap
  • treefall gap
  • triplet energy gap
  • wage gap
  • wide gap
  • widening gap

  • Terms modified by Gap

  • gap activity
  • gap analysis
  • gap distance
  • gap distribution
  • gap energy
  • gap formation
  • gap junction
  • gap junction blocker
  • gap junction channel
  • gap junction protein
  • gap junctional communication
  • gap junctional coupling
  • gap junctional intercellular communication
  • gap length
  • gap material
  • gap opening
  • gap semiconductor
  • gap size
  • gap thickness
  • gap treatment
  • gap value
  • gap width

  • Selected Abstracts


    Programming scientific and distributed workflow with Triana services

    CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 10 2006
    David Churches
    Abstract In this paper, we discuss a real-world application scenario that uses three distinct types of workflow within the Triana problem-solving environment: serial scientific workflow for the data processing of gravitational wave signals; job submission workflows that execute Triana services on a testbed; and monitoring workflows that examine and modify the behaviour of the executing application. We briefly describe the Triana distribution mechanisms and the underlying architectures that we can support. Our middleware independent abstraction layer, called the Grid Application Prototype (GAP), enables us to advertise, discover and communicate with Web and peer-to-peer (P2P) services. We show how gravitational wave search algorithms have been implemented to distribute both the search computation and data across the European GridLab testbed, using a combination of Web services, Globus interaction and P2P infrastructures. Copyright © 2005 John Wiley & Sons, Ltd. [source]


    THE NARROWING GENDER GAP IN ARRESTS: ASSESSING COMPETING EXPLANATIONS USING SELF-REPORT, TRAFFIC FATALITY, AND OFFICIAL DATA ON DRUNK DRIVING, 1980,2004,

    CRIMINOLOGY, Issue 3 2008
    JENNIFER SCHWARTZ
    We evaluate two alternative explanations for the converging gender gap in arrest,changes in women's behavior versus changes in mechanisms of social control. Using the offense of drunk driving and three methodologically diverse data sets, we explore trends in the DUI gender gap. We probe for change across various age groups and across measures tapping DUI prevalence and chronicity. Augmented Dickey-Fuller time-series techniques are used to assess changes in the gender gap and levels of drunk driving from 1980 to 2004. Analyses show women of all ages making arrest gains on men,a converging gender gap. In contrast, self-report and traffic data indicate little or no systematic change in the DUI gender gap. Findings support the conclusion that mechanisms of social control have shifted to target female offending patterns disproportionately. Little support exists for the contention that increased strain and liberalized gender roles have altered the gender gap or female drunk-driving patterns. [source]


    STRUCTURAL INEQUALITY AND HOMICIDE: AN ASSESSMENT OF THE BLACK-WHITE GAP IN KILLINGS,

    CRIMINOLOGY, Issue 3 2003
    MARÍA B. VÉLEZ
    This paper examines the relationship between race and violent crime by directly modeling the racial gap in homicide offending for large central cities for 1990. We evaluate the role of black-white differences in aspects of both disadvantage and resources in explaining which places have wider racial disparities in lethal violence. The results show that where residential segregation is higher, and where whites' levels of homeownership, median income, college graduation, and professional workers exceed those for blacks to a greater degree, African Americans have much higher levels of homicide offending than whites. Based on these results, we conclude that the racial homicide gap is better explained by the greater resources that exist among whites than by the higher levels of disadvantage among blacks. [source]


    CAN SCIENCE HELP CLOSE THE TREATMENT GAP?

    ADDICTION, Issue 1 2010
    MARÍA ELENA MEDINA-MORA
    No abstract is available for this article. [source]


    Directions in Rural Development Policy , Lessons from Both Sides of the Atlantic Richtlinien für die ländliche Entwicklungspolitik , Beispiele von diesseits und jenseits des Atlantiks Les orientations de la politique de développement rural , Enseignements en provenance des deux côtés de l'Atlantique

    EUROCHOICES, Issue 1 2008
    David Blandford
    Directions in Rural Development Policy , Lessons from Both Sides of the Atlantic A workshop comparing rural development policies in Europe and the US found differences in the social values that shape them. These include different attachments to place, concerns with lagging regions, and interests in the assessment of public interventions. There is also a difference in coverage. In the EU environmental and landscape issues form part of the CAP's Rural Development Pillar, using agriculture as an instrument, whereas in the US these are handled by other policies, some of which can claim deeper historical roots. In the context of rural development policy, the EU attaches intrinsic value to the environment, while in the US the focus is more on economic spin-offs from environmental quality. There are also differences in governance; a complete US view requires taking in Federal, State and local initiatives whereas in the EU a more organised framework is apparent. Nevertheless, when policy is viewed from a bottom-up perspective many common features are found. Improving human and social capital and infrastructure are key factors to stimulating economic development on both sides of the Atlantic, though only some of these drivers form part of the CAP's Pillar II. While in the EU the role of rural development is set to expand, this is far less certain in the US where the emphasis on agricultural support is likely to continue to dominate the political agenda. Les orientations de la politique de développement rural , Enseignements en provenance des deux côtés de l'Atlantique Un atelier comparant les politiques de développement rural en Europe et aux États-Unis a mis en évidence des différences entre les valeurs sociales sur lesquelles sont fondées ces politiques. Ces différences concernent entre autre l'attachement à des lieux particuliers, l'inquiétude pour les régions en retard de croissance, et l'intérêt pour une évaluation des pouvoirs publics. Les différences portent aussi sur l'étendue de la question. Dans l'Union européenne, les questions portant sur le paysage et l'environnement sont abordées dans le cadre du pilier de la PAC sur le développement rural, qui porte sur l'agriculture comme instrument du développement rural, alors qu'aux États-Unis, ces questions sont traitées par d'autres politiques dont certaines remontent à loin. Dans le contexte de la politique de développement rural, l'Union européenne attache une valeur intrinsèque à l'environnement tandis qu'aux États-Unis, l'accent est mis plutôt sur les retombées économiques d'un environnement de qualité. Les différences portent également sur la gouvernance : pour avoir une vue d'ensemble sur les États-Unis, il faut considérer les actions aux niveaux fédéral, des États et du local alors que dans l'Union européenne, un cadre plus organisé est apparent. Cependant, dans le cas de politiques partant de la base (bottom-up), de nombreux points communs existent. L'amélioration du capital social et humain, et celle des infrastructures sont des éléments clés pour stimuler le développement économique des deux côtés de l'Atlantique, même si seuls quelques uns de ces facteurs sont compris dans le deuxième pilier de la PAC. Alors que le rôle du développement rural devrait s'étendre dans l'Union européenne, c'est beaucoup moins certain aux États-Unis où l'accent sur le soutien à l'agriculture continuera probablement à dominer l'ordre du jour de la politique. Richtlinien für die ländliche Entwicklungspolitik , Beispiele von diesseits und jenseits des Atlantiks Im Rahmen eines Workshops wurden europäische und US-amerikanische Politikmaßnahmen zur Entwicklung des ländlichen Raums miteinander verglichen. Die Ergebnisse zeigen, dass sich die gesellschaftlichen Werte für die Ausgestaltung der Politikmaßnahmen im Hinblick auf Ortsverbundenheit, die Belange der rückständigen Regionen und das Interesse bei der Bewertung öffentlicher Interventionen unterscheiden. Die jeweiligen Geltungsbereiche unterscheiden sich ebenfalls. In der EU bilden Fragestellungen in Bezug auf Umwelt und landschaftliche Gestaltung einen Teil der zweiten Säule der GAP (Entwicklung des ländlichen Raums), und die Landwirtschaft ist dabei ein Mittel zum Zweck. In den USA hingegen werden diese Fragestellungen durch andere Politikmaßnahmen abgedeckt, von denen einige über längere historische Wurzeln verfügen. Im Rahmen der Politik zur Entwicklung des ländlichen Raums misst die EU der Umwelt intrinsischen Wert bei, während sich die USA mehr auf aus der Umweltqualität resultierende wirtschaftliche Nebeneffekte konzentriert. Im Hinblick auf die Governance sind ebenfalls Unterschiede vorhanden: Während es im Falle der USA erforderlich ist, in einer Gesamtbetrachtung die Initiativen auf staatlicher, bundesstaatlicher und kommunaler Ebene zu berücksichtigen, lassen die Rahmenbedingungen in Europa ein höheres Maß an Organisation erkennen. Wird die Politik jedoch aus einer Bottom-up-Perspektive heraus betrachtet, können zahlreiche Gemeinsamkeiten gefunden werden. Bei der Verbesserung des Human- und Sozialkapitals und der Infrastruktur handelt es sich um Schlüsselfaktoren für die Ankurbelung der wirtschaftlichen Entwicklung diesseits und jenseits des Atlantiks, wenngleich nur einige dieser Triebfedern die zweite Säule der GAP ausmachen. Während die Entwicklung des ländlichen Raums in der EU eine immer größere Rolle spielen wird, ist dies in den USA längst nicht sicher; dort wird der Schwerpunkt auf die Agrarstützung wahrscheinlich weiterhin die politische Agenda dominieren. [source]


    Our Common European Model of Agriculture

    EUROCHOICES, Issue 3 2006
    Juha Korkeaoja
    Our Common European Model of Agriculture Future internal and external forces on European agriculture mean that the CAP may look very different after 2013. However large these changes, the CAP will need to retain its common principles based on the European Model of Agriculture (EMA). This became clear in an informal September meeting of EU agriculture ministers in Oulu, arranged by the Finnish Presidency. A strong CAP will be needed in the future but it will have to evolve to meet upcoming challenges. Work on the future CAP will need to start soon and the Oulu meeting may become known as the starting point for those discussions. The CAP will have to provide a reasonable environment for practicing agriculture for very different farmers in very diverse conditions, and facilitate the supply of a wide variety of goods and services to consumers and taxpayers as only truly multifunctional agriculture can. If the CAP can maintain these characteristics it has an important role to play in a future Europe. The meeting in Oulu was also an important milestone for a very special reason: for the first time, all ten New Member States took an active part in the EMA-debate with full rights and responsibilities as part of the Union. Once again this underlines the central role of our common European Model of Agriculture. Unser gemeinsames Europäisches Land wirts chafts modell Die zukünftigen internen und externen Einflüsse auf die europäische Landwirtschaft könnten zur Folge haben, dass die GAP nach dem Jahr 2013 ganz anders aussieht. Wie umwälzend diese Veränderungen auch sein mögen, die GAP wird ihre allgemeinen, auf dem Europäischen Landwirtschaftsmodell (EMA) beruhenden Grundsätze beibehalten müssen. Dies wurde im September bei einem von der finnischen Präsidentschaft arrangierten informellen Treffen der EU-Landwirtschaftsminister in Oulu deutlich. In der Zukunft brauchen wir eine starke GAP, die jedoch weiterentwickelt werden muss, um den kommenden Herausforderungen gerecht zu werden. Die Arbeit an der zukünftigen GAP muss in nächster Zeit beginnen, und das Treffen in Oulu könnte möglicherweise als Ausgangspunkt dieser Diskussionen gelten. Die GAP wird ein angemessenes Umfeld schaffen müssen, um sehr unterschiedlichen Landwirten mit sehr unterschiedlichen Arbeitsbedingungen die Ausübung der Landwirtschaft sowie Verbrauchern und Steuerzahlern die Versorgung mit einer großen Vielfalt an Waren und Dienstleistungen zu ermöglichen, wie es nur eine wirklich multifunktionale Landwirtschaft zu leisten vermag. Wenn es der GAP gelingt, diese Merkmale beizubehalten, wird ihr im zukünftigen Europa eine wichtige Rolle zukommen. Bei dem Treffen in Oulu handelt es sich auch aus einem ganz besonderen Grund um einen bedeutenden Meilenstein: Zum ersten Mal beteiligte sich jeder der zehn neuen Mitgliedsstaaten mit allen Rechten und voller Verantwortung als Teil der Union aktiv an der Debatte zum Europäischen Landwirtschaftsmodell. Wieder einmal unterstreicht dies die zentrale Rolle unseres gemeinsamen Europäischen Landwirtschaftsmodells. Ce modèle agricole européen qui nous est commun Du fait des forces internes et externes qui vont bientôt s'exercer sur l'agriculture européenne, la physionomie de la PAC après 2013 pourrait bien être très différente de ce qu'elle est maintenant. Quelque soit cependant l'importance de ces changements, la PAC devra conserver sa base commune actuelle, qui repose sur le « modèle agricole européen » (MAE). La chose est apparue clairement lors d'une réunion informelle des ministres de l'agriculture européens organisée par la présidence finnoise à Oulu, en septembre dernier. Une politique agricole musclée sera nécessaire à l'avenir, mais elle devra évoluer pour répondre à de nouveaux défis. Il va bientôt falloir commencer à travailler cette nouvelle PAC, et la réunion d'Oulu restera peut être comme le point de départ des discussions sur le sujet. La PAC devra fournir un environnement convenable pour la pratique d'agricultures diverses, par des agriculteurs différents les uns des autres, dans un vaste éventail de conditions. Elle devra permettre la production d'une grande variété de biens et de services financés par le consommateur ou le contribuable, comme seule une agriculture multifonctionnelle peut le faire. Si la PAC arrive à conserver ces caractéristiques, elle aura un grand rôle à jouer dans l'Europe de demain. Il y a encore une raison plus spécifique pour marquer d'une pierre blanche la réunion d'Oulu : pour la première fois, les dix nouveaux membres de l'Union ont activement participé et de plein droit aux discussions sur le MAE. Cela, une fois de plus, souligne le rôle essentiel du « modèle agricole européen » qui nous est commun. [source]


    Delivering on the Potential of the New CAP

    EUROCHOICES, Issue 2 2005
    Mariann Fischer Boel
    Recent discussions on the CAP have focused on the budget. However, in the public debate the policy itself is often still a caricature of the old CAP that existed until the early 1990s. The CAP has changed fundamentally over the past decade. The recent direction of the CAP , markets and rural development , was set by the European Council in Göteborg and Lisbon. Strong economic performance must go hand in hand with the sustainable use of natural resources. The key elements of the new CAP are a market policy where intervention is a safety net, income stabilisation is delivered through decoupled aids subject to cross-compliance, and a reinforced rural development policy that focuses on jobs, growth and sustainability. We must use the new CAP to unlock the potential for growth, jobs and innovation and put good ideas into practice. We need to work in partnership with farmers, foresters, the agrifood business, NGOs, the population of rural areas, the research community and of course public authorities. But to achieve all of this we need a stable budgetary environment, in which farmers and businesses can plan. In short, we need the resources to deliver on the potential of the new CAP. Les discussions sur la PAC, récemment, se sont focalisées sur le budget. En même temps, le contenu politique de la réforme, tel qu'il est vu dans le débat public, n'est rien d'autre que la caricature de l'ancienne PAC telle qu'elle existait avant les années 90. Or, au cours de la dernière décennie, la PAC a radicalement changé. Son nouveau cours , axé sur les marchés et le développement rural , a été défini lors des conseils européens de Göteborg et de Lisbonne. Les bonnes performances économiques doivent aller de concert avec l'utilisation durable des ressources naturelles. Une politique de marché, pour laquelle l'intervention n'est qu'un filet de sécurité, une stabilisation des revenus qui prend la forme d'aides découplées sous réserve d'application de normes, un développement rural renforcé, enfin, centré sur les emplois, la croissance et la durabilité, voilà les clés de la nouvelle PAC. Celle-ci doit être utilisée pour déchaîner les possibilités en matière de croissance d'emplois, d'innovation et de durabilité. Il faut pour cela s'appuyer sur les agriculteurs, les forestiers, les industries agroalimentaires, les organisations non gouvernementales, les populations des zones rurales, les chercheurs, et bien sûr les autorités publiques. Mais pour réaliser tout cela, il faut encore un environnement budgétaire stable, permettant aux agriculteurs et aux industriels de planifi er leurs actions. En d'autres termes, il faut des ressources pour que la nouvelle PAC tienne ses promesses. Die jüngsten Diskussionen über die GAP konzentrierten sich auf den Haushalt. In der öffentlichen Debatte ist die Politik selbst jedoch häufig noch ein Zerrbild der alten GAP, wie diese sich bis in die frühen 1990er Jahre darstellte. In den letzten zehn Jahren hat sich die GAP von Grund auf verändert. Die jüngste Richtung der GAP , Märkte und die Entwicklung des ländlichen Raums , wurde vom Europäischen Rat in Göteborg und Lissabon vorgegeben. Eine hohe wirtschaftliche Leistungsfähigkeit muss mit der nachhaltigen Nutzung der natürlichen Ressourcen Hand in Hand gehen. Die Schlüsselelemente der neuen GAP sind eine Marktpolitik, in der die Intervention als Sicherheitsnetz dient und eine Einkommensstabilisierung mittels entkoppelter Beihilfen erfolgt, für die Cross Compliance gilt; sowie eine gestärkte Politik zur Entwicklung des ländlichen Raums, welche sich auf Arbeitsplätze, Wachstum sowie Nachhaltigkeit konzentriert. Wir müssen die neue GAP dazu verwenden, das Potenzial für Wachstum, Arbeitsplätze und Innovationen frei zu setzen, und gute Ideen in die Tat umsetzen. Wir müssen partnerschaftlich mit den Landwirten, Förstern, Unternehmen der Agrar- und Ernährungswirtschaft, Nicht-Regierungsorganisationen (NRG), der Landbevölkerung, der Forschungsgemeinschaft und natürlich der öffentlichen Verwaltung zusammen arbeiten. Dafür benötigen wir jedoch eine stabile Haushaltssituation, die es den Landwirten und Unternehmen ermöglicht zu planen. Kurzum: Wir benötigen die Ressourcen, um das Potenzial der GAP auszuschöpfen. [source]


    The CAP for Turkey?

    EUROCHOICES, Issue 2 2005
    Budgetary Implications, Potential Market Effects
    EU accession negotiations with Turkey are scheduled to start in October 2005. The period of accession negotiations will probably last for ten years or longer, but the effects of applying the Common Agricultural Policy (CAP) to Turkey are currently a controversial discussion in the EU. Effects of Turkish accession on EU agricultural markets are likely to be small. The EU would gain additional export opportunities for cereals and animal products. On the other hand, Turkish agricultural exports to the EU are projected to increase for only a few fruit and vegetable products. EU budgetary outlays for the application of the CAP to Turkey could total between £3.5 and £6.3 billion in 2015 , depending on whether direct payments are phased in or not , and £5.4 billion in 2025. Most of these outlays would be for direct payments to agricultural producers and that may not be in Turkey's best interest. This is because direct payments tend to be capitalized in land prices and may thus inhibit the necessary process of improving the Turkish agricultural structure. Transfers under the second pillar of the CAP may hold more interest for Turkey, because they can be targeted at improving productivity and thereby income. Projected outlays for the CAP take a backseat to projected transfers to Turkey under the structural policy of the EU. Les négociations sur l'adhésion de la Turquie à l'UE doivent commencer en octobre 2005. Les préliminaires vont sans doute durer au moins une dizaine d'années, mais les effets de l'application de la Politique Agricole Commune (PAC) à la Turquie font déjà l'objet de controverses au sein de l'UE. Sur les marchés, on s'attend à des effets plutôt faibles. L'UE gagnerait certaines possibilités d'exportation de céréales et de produits animaux. Par ailleurs, les exportations de la Turquie vers l'UE ne s'accroîtraient que pour quelques fruits et légumes. Les dépenses budgétaires totales qui résulteraient pour l'UE de l'application de la PAC à la Turquie se situeraient en 2015 entre 3,5 et 6,3 milliards d'Euros, selon que les paiements directs seront ou ne seront pas progressivement éliminés. Elles atteindraient 5,4 milliards en 2025. Il s'agirait pour l'essentiel de paiements directs aux producteurs agricoles, ce qui ne correspondrait pas forcément à l'intérêt bien compris de la Turquie. De fait, les paiements directs tendent àêtre capitalisés en valeurs foncières. Ils pourraient par conséquent inhiber le processus d'amélioration des structures, pourtant bien nécessaire. Les transferts liés au second pilier de la PAC pourraient être plus utiles, parce qu'ils peuvent être ciblés sur les accroissements de productivité et donc de revenus. C'est pourquoi il y a lieu d'envisager des transferts à la Turquie au titre des politiques d'amélioration de structures en arrière plan des budgets prévisionnels pour la PAC. Im Oktober 2005 sollen die EU-Beitrittsverhandlungen mit der Türkei beginnen. Diese Verhandlungen werden wahrscheinlich über einen Zeitraum von zehn Jahren oder länger geführt werden, die Auswirkungen der Gemeinsamen Agrarpolitik (GAP) auf die Türkei werden im Moment in der EU jedoch kontrovers diskutiert. Der EU-Beitritt der Türkei wird sich wahrscheinlich nur geringfügig auf die EU-Agrarmärkte auswirken. Die EU erhielte zusätzliche Exportmöglichkeiten für Getreide und tierische Erzeugnisse. Die Agrarexporte der Türkei in die EU hingegen würden vermutlich nur bei einigen wenigen Obstund Gemüseprodukten zunehmen. Durch die Anwendung der GAP auf die Türkei würde der EU-Haushalt im Jahr 2015 mit 3,5 bis 6,3 Milliarden Euro (je nachdem, ob die Direktzahlungen schrittweise eingeführt werden oder nicht) und im Jahr 2025 mit 5,4 Milliarden Euro belastet. Der grö,te Teil dieser Kosten entstünde aufgrund von Direktzahlungen an landwirtschaftliche Erzeuger. Dies dürfte für die Türkei nicht die bestmögliche Alternative darstellen, da Direktzahlungen zumeist in den Bodenpreisen kapitalisiert werden, wodurch der notwendige Prozess zur Verbesserung der türkischen Agrarstruktur ins Stocken geraten könnte. Transferleistungen im Rahmen der zweiten Säule der GAP dürften für die Türkei interessanter sein, da sie auf eine Produktivitätssteigerung ausgerichtet werden könnten, um so die Einkommenssituation zu verbessern. Die zu erwartenden Ausgaben für die GAP im Rahmen der Strukturpolitik der EU spielen im Vergleich zu den zu erwartenden Transferleistungen an die Türkei eine untergeordnete Rolle. [source]


    Differential actions of p60c-Src and Lck kinases on the Ras regulators p120-GAP and GDP/GTP exchange factor CDC25Mm

    FEBS JOURNAL, Issue 11 2001
    Carmela Giglione
    It is known that the human Ras GTPase activating protein (GAP) p120-GAP can be phosphorylated by different members of the Src kinase family and recently phosphorylation of the GDP/GTP exchange factor (GEF) CDC25Mm/GRF1 by proteins of the Src kinase family has been revealed in vivo[Kiyono, M., Kaziro, Y. & Satoh, T. (2000) J. Biol. Chem.275, 5441,5446]. As it still remains unclear how these phosphorylations can influence the Ras pathway we have analyzed the ability of p60c-Src and Lck to phosphorylate these two Ras regulators and have compared the activity of the phosphorylated and unphosphorylated forms. Both kinases were found to phosphorylate full-length or truncated forms of GAP and GEF. The use of the catalytic domain of p60c-Src showed that its SH3/SH2 domains are not required for the interaction and the phosphorylation of both regulators. Remarkably, the phosphorylations by the two kinases were accompanied by different functional effects. The phosphorylation of p120-GAP by p60c-Src inhibited its ability to stimulate the Ha-Ras-GTPase activity, whereas phosphorylation by Lck did not display any effect. A different picture became evident with CDC25Mm; phosphorylation by Lck increased its capacity to stimulate the GDP/GTP exchange on Ha-Ras, whereas its phosphorylation by p60c-Src was ineffective. Our results suggest that phosphorylation by p60c-Src and Lck is a selective process that can modulate the activity of p120-GAP and CDC25Mm towards Ras proteins. [source]


    Screening for target Rabs of TBC (Tre-2/Bub2/Cdc16) domain-containing proteins based on their Rab-binding activity

    GENES TO CELLS, Issue 9 2006
    Takashi Itoh
    It has recently been proposed that the TBC (Tre2/Bub2/Cdc16) domain functions as a GAP (GTPase-activating protein) domain for small GTPase Rab. Because of the large number of Rab proteins in mammals, however, most TBC domains have never been investigated for Rab-GAP activity. In this study we established panels of the GTP-fixed form of 60 different Rabs constructed in pGAD-C1, a yeast two-hybrid bait vector. We also constructed a yeast two-hybrid prey vector (pGBDU-C1) that harbors the cDNA of 40 distinct TBC proteins. Systematic investigation of 2400 combinations of 60 GTP-fixed Rabs and 40 TBC proteins by yeast two-hybrid screening revealed that seven TBC proteins specifically and differentially interact with specific Rabs (e.g. OATL1 interacts with Rab2A; FLJ12085 with Rab5A/B/C; and Evi5-like with Rab10). Measurement of in vitro Rab-GAP activity revealed that OATL1 and Evi5-like actually possess significant Rab2A- and Rab10-GAP activity, respectively, but that FLJ12085 do not display Rab5A-GAP activity at all. These results indicate that specific interaction between TBC protein and Rab would be a useful indicator for screening for the target Rabs of some TBC/Rab-GAP domains, but that there is little correlation between the Rab-binding activity and Rab-GAP activity of other TBC proteins. [source]


    Characterization of GTPase-activating proteins for the function of the Rho-family small GTPases in the fission yeast Schizosaccharomyces pombe

    GENES TO CELLS, Issue 12 2001
    Kentaro Nakano
    Background The small GTPase Rho1 has been shown to regulate the organization of the actin cytoskeleton and formation of the cell wall in the fission yeast Schizosaccharomyces pombe. Activity of Rho1 must be precisely regulated in vivo, since both increases and decreases in its activity affect cell growth and shape. Thus, it is important to clarify the mechanism by which the activity of Rho1 is regulated in vivo. Results Seven genes encoding putative GAPs, GTPase-activating proteins, for the function of the Rho-family proteins were isolated from S. pombe. After disruption of these genes, rga1+ was found to play important roles in cell growth and morphogenesis. In rga1 null cells, delocalized F-actin patches and extraordinary thickening of the cell wall and the septum were observed. On the other hand, over-expression of Rga1 produced shrunken or dumpy cells. The phenotype of the rga1 null cells or the Rga1-over-expressing cells was similar to that of cells containing abnormally high or low Rho1 activity, respectively. Moreover, direct association of Rga1 with Rho1 was shown. Rga1 was localized to the cell ends and septum where Rho1 is known to function. Conclusions In S. pombe, Rga1 is involved in the F-actin patch localization, cell morphogenesis, regulation of septation, and cell wall synthesis, probably functioning as a GAP for the function of Rho1. [source]


    Role of the Rap1 GTPase in astrocyte growth regulation

    GLIA, Issue 3 2003
    Anthony J. Apicelli
    Abstract Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome in which affected individuals develop nervous system abnormalities that might reflect astrocyte dysfunction. The TSC2 gene product, tuberin, encodes a GTPase-activating protein (GAP) domain, which regulates the activity of Rap1 in vitro. To determine whether dysregulated Rap1, resulting from TSC2 inactivation, leads to increased astrocyte proliferation in vivo, we generated transgenic mice expressing activated Rap1G12V specifically in astrocytes. We observed no statistically significant difference in the number of astrocytes between wild-type and GFAP-Rap1G12V littermates in vivo; however, during log-phase growth, we observed a 25% increase in GFAP-Rap1G12V astrocyte doubling times compared to wild-type controls. This decreased proliferation was associated with delayed MAP kinase, but not AKT, activation. Lastly, to determine whether constitutive Rap1 activation could reverse the increased astrocyte proliferation observed in transgenic mice expressing oncogenic RasG12V, we generated transgenic mice expressing both RasG12V and Rap1G12V in astrocytes. These double transgenic mice showed a striking reversion of the RasG12V astrocyte growth phenotype. Collectively, these results argue that the tumor suppressor properties of tuberin are unlikely to be related to Rap1 inactivation and that Rap1 inhibits mitogenic Ras pathway signaling in astrocytes. GLIA 42:225,234, 2003. © 2003 Wiley-Liss, Inc. [source]


    An Improved Preparation of D -Glyceraldehyde 3-Phosphate and Its Use in the Synthesis of 1-Deoxy- D -xylulose 5-Phosphate

    HELVETICA CHIMICA ACTA, Issue 9 2010
    Heng Li
    Abstract D -Glyceraldehyde 3-phosphate (=D -GAP; 2) was prepared by an improved chemical method (Scheme,2), and it was then employed to synthesize 1-deoxy- D -xylulose 5-phosphate (=DXP; 3) which is enzymatically one of the key intermediates in the MEP (4) terpenoid biosynthetic pathway (Scheme,1). The recombinant DXP synthase of Rhodobacter capsulatus was used to catalyze the condensation of D -glyceraldehyde 3-phosphate (2) and pyruvate (=2-oxopropanoate; 1) to produce the sugar phosphate 3 (Scheme,2). The simple two-step chemoenzymatic route described affords DXP (3) with more than 70% overall yield and higher than 95% purity. The procedure may also be used for the synthesis of isotope-labeled DXP (3) by using isotope-labeled pyruvate. [source]


    Computing the full nonrigid group of tetra-tert-butyltetrahedrane using wreath product

    INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 5 2005
    Mohammad Reza Darafsheh
    Abstract The concept of symmetry group of nonrigid molecules as a permutation-inversion group was formulated first by Longuet-Higgins, although earlier works suggested the need for such a framework. Then Balasubramanian showed that these groups could be cast into elegant algebraic structures known as the wreath product of groups. In this study, we apply a similar method to that used by Balasubramanian to find the nonrigid group (NRG) of tetra-tert-butyltetrahedrane. Using the group theory package GAP, we calculate the conjugacy classes and character table of this molecule. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 [source]


    The generalized assortment and best cutting stock length problems

    INTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH, Issue 1 2010
    John F. Raffensperger
    Abstract This paper introduces two new one-dimensional cutting stock models: the generalized assortment problem (GAP) and the best cutting stock length (BSL) problem. These new models provide the potential to reduce waste to values lower than the optimum of current models, under the right management circumstances. In the GAP, management has a standard length and can select one or more of any additional custom stock lengths, and management wishes to minimize cutting stock waste. This model is different from existing models that assume that the selection is from a small fixed set of stock lengths. In the BSL problem, management chooses any number of custom stock lengths, but wishes to find the fewest custom stock lengths in order to have zero waste. Results show waste reductions of 80% with just one custom stock length compared with solutions from standard cutting stock formulations, when item lengths are long relative to the stock length. The models are most effective when the item lengths are nearly as long as the stock length. Solutions from the model have been implemented for a manufacturer. The model is easily generalized to allow multiple existing stock lengths and different costs. [source]


    Incomplete adherence to an adjunctive systemic antibiotic regimen decreases clinical outcomes in generalized aggressive periodontitis patients: a pilot retrospective study

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2007
    Adrian Guerrero
    Abstract Aim: The objective of this study was to explore the effect of incomplete adherence to the prescribed antibiotic regimen, amoxicillin and metronidazole, in the non-surgical treatment of generalized aggressive periodontitis (GAP). Methods: This retrospective study included 18 GAP subjects who received a conventional course of full-mouth non-surgical periodontal treatment using machine-driven and hand instruments and an adjunctive course of systemic antibiotics (500 mg amoxicillin and 500 mg metronidazole three times a day for 7 days). Clinical parameters were collected at baseline and at 2 months post-treatment. Self-reported adherence to the prescribed medication regimen was recorded at 2 months. Results: All clinical parameters, except for the mean clinical attachment level (CAL) in sites with initial probing pocket depth (PPD) 3 mm, improved at 2 months in all subjects. PPD reduction was 3.7 mm [95% confidence interval (CI) 3.2, 4.3 mm] in deep pockets (7 mm) and 2.2 mm (95% CI 1.9, 2.4 mm) in moderate pockets (4,6 mm), while CAL gain was 2.2 mm (95% CI 1.7, 2.6 mm) and 1.2 mm (95% CI 0.8, 1.5 mm), respectively. However, only 11 subjects (61.1%) reported full adherence to the medication. In deep pockets (7 mm), the difference between an adherent and non-adherent/partially adherent subject was 0.9 mm (95% CI 0.1, 1.7 mm, ancova, p=0.027) in PPD reduction and 0.8 mm (95% CI ,0.2, 1.9, p=0.129) in CAL gain at 2 months. In moderate pockets (4,6 mm) this difference was smaller in magnitude: 0.4 mm (95% CI 0.1, 0.9 mm, p=0.036) in PPD reduction and 0.2 mm (95% CI ,0.3, 0.9 mm, p=0.332) in CAL gain. Conclusions: Within the limits of this design, these data suggest that incomplete adherence to a 7-day adjunctive course of systemic metronidazole and amoxicillin is associated with decreased clinical outcomes in subjects with generalized aggressive periodontitis. [source]


    Adjunctive benefits of systemic amoxicillin and metronidazole in non-surgical treatment of generalized aggressive periodontitis: a randomized placebo-controlled clinical trial

    JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2005
    Adrian Guerrero
    Abstract Background: The objective of this study was to assess the adjunctive clinical effect of the administration of systemic amoxicillin and metronidazole in the non-surgical treatment of generalized aggressive periodontitis (GAP). Methods: Forty-one systemically healthy subjects with GAP were included in this 6-month double-blind, placebo-controlled, randomized clinical trial. Patients received a course of full-mouth non-surgical periodontal treatment delivered over a 24 h period using machine-driven and hand instruments. Test subjects received an adjunctive course of systemic antibiotic consisting of 500 mg amoxicillin and 500 mg metronidazole three times a day for 7 days. Clinical parameters were collected at baseline, and at 2 and 6 months post-treatment. Results: In both the test and the placebo groups, all clinical parameters improved at 2 and 6 months. In deep pockets (7 mm), the test treatment resulted in an additional 1.4 mm (95% confidence interval 0.8, 2.0 mm) in full-mouth probing pocket depth (PPD) reduction and 1 mm (0.7, 1.3 mm) of life cumulative attachment loss (LCAL) gain at 6 months. In moderate pockets (4,6 mm), the adjunctive benefit was smaller in magnitude: PPD reduction was 0.4 mm (0.1, 0.7 mm) and LCAL gain was 0.5 mm (0.2, 0.8 mm). In addition, the 6-month data showed LCAL gains 2 mm at 25% of sites in test patients compared with 16% in placebo (p=0.028). Similarly, PPD reductions of 2 mm or more were observed in 30% of sites in test and 21% of sites in placebo patients. Seventy-four percent of pockets with PPD 5 mm at baseline were 4 mm or shallower at 6 months in the test group. This compared with 54% in the placebo group (p=0.008). Disease progression at 6 months was observed at 1.5% of test and 3.3% of sites in test and placebo, respectively (p=0.072). Conclusions: These data indicate that a 7-day adjunctive course of systemic metronidazole and amoxicillin significantly improved the short-term clinical outcomes of full-mouth non-surgical periodontal debridement in subjects with GAP. [source]


    MIND THE GAP: UNEMPLOYMENT IN THE NEW EU REGIONS

    JOURNAL OF ECONOMIC SURVEYS, Issue 1 2008
    Anna Maria Ferragina
    Abstract The paper surveys the theoretical and empirical literature on regional unemployment during transition in Central and Eastern Europe. The focus is on optimal speed of transition (OST) models and on comparison of them with the neo-classical tradition. In the typical neo-classical models, spatial differences essentially arise as a consequence of supply side constraints and institutional rigidities. Slow-growth, high-unemployment regions are those with backward economic structures and constraints on factors mobility contribute to making differences persistent. However, such explanations leave the question unanswered of how unemployment differences arise in the first place. Economic transition provides an excellent testing ground to answer this question. Pre-figuring an empirical law, the OST literature finds that the high degree of labour turnover of high unemployment regions is associated with a high rate of industrial restructuring and, consequently, that low unemployment may be achieved by implementing transition more gradually. Moreover, international trade, foreign direct investment and various agglomeration factors help explain the success of capital cities compared to peripheral towns and rural areas in achieving low unemployment. The evidence of the empirical literature on supply side factors suggests that wage flexibility in Central and Eastern Europe is not lower than in other EU countries, while labour mobility seems to reinforce rather than change the spatial pattern of unemployment. [source]


    CHANGES IN THE RELATIVE EARNINGS GAP BETWEEN NATIVES AND IMMIGRANTS ALONG THE U.S.-MEXICO BORDER,

    JOURNAL OF REGIONAL SCIENCE, Issue 3 2008
    Alberto Dávila
    ABSTRACT Using 1990 and 2000 U.S. census data, this study investigates changes in immigrant/native earnings disparities for workers in U.S. cities along the international border with Mexico vis-à-vis the U.S. interior during the 1990s. Our findings,based on estimating earnings functions and employing the Juhn-Murphy-Pierce (1993, JPE) wage decomposition technique,indicate that the average earnings of Mexican immigrants along the U.S.-Mexico border improved relative to those accrued by their counterparts in the U.S. interior and by otherwise similar U.S.-born Mexican Americans between 1990 and 2000. However, when comparing Mexican-born workers to U.S.-born non-Hispanic whites, the immigrant border-earnings penalty remained statistically unchanged. [source]


    Breast reconstruction using perforator flaps

    JOURNAL OF SURGICAL ONCOLOGY, Issue 6 2006
    Jay W. Granzow MD
    Abstract Background Perforator flaps allow the transfer of the patient's own skin and fat in a reliable manner with minimal donor-site morbidity. The deep inferior epigastric artery (DIEP) and superficial inferior epigastric artery (SIEA) flaps transfer the same tissue from the abdomen to the chest for breast reconstruction as the TRAM flap without sacrificing the rectus muscle or fascia. Gluteal artery perforator (GAP) flaps allow transfer of tissue from the buttock, also with minimal donor-site morbidity. Indications Most women requiring tissue transfer to the chest for breast reconstruction or other reasons are candidates for perforator flaps. Absolute contraindications to perforator flap breast reconstruction include history of previous liposuction of the donor site or active smoking (within 1 month prior to surgery). Anatomy and Technique The DIEP flap is supplied by intramuscular perforators from the deep inferior epigastric artery and vein. The SIEA flap is based on the SIEA and vein, which arise from the common femoral artery and saphenous bulb. GAP flaps are based on perforators from either the superior or inferior gluteal artery. During flap harvest, these perforators are meticulously dissected free from the surrounding muscle which is spread in the direction of the muscle fibers and preserved intact. The pedicle is anastomosed to recipient vessels in the chest and the donor site is closed without the use of mesh or other materials. Conclusions Perforator flaps allow the safe and reliable transfer of abdominal tissue for breast reconstruction. J. Surg. Oncol. 2006;94:441,454. © 2006 Wiley-Liss, Inc. [source]


    Effect of supplementation of garlic powder on rumen ecology and digestibility of nutrients in ruminants

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 13 2008
    Metha Wanapat
    Abstract BACKGROUND: The present study investigated the effect of garlic powder (GAP) supplementation on rumen fermentation pattern, nutrient digestibility and intake in ruminants fed on straw as a roughage source. RESULTS: Dry matter intake and apparent digestibility of nutrients were similar among treatments. The apparent digestibility of crude protein tended to be higher in cattle supplemented with GAP compared to those fed without GAP (P = 0.08). Ruminal populations of protozoa and bacteria were decreased, as influenced by GAP supplementation. Ruminal pH and NH3 -N were similar among treatments, while blood urea nitrogen tended to be decreased (P < 0.05). Total volatile fatty acids (VFAs) were not affected by GAP supplementation but individual VFAs were significantly different (P < 0.05), especially C3; meanwhile, C2:C3 ratio was reduced by GAP supplementation (P < 0.05). In addition, N balances were significantly increased as level of GAP supplementation increased and was highest at 120 g d,1 GAP. CONCLUSION: Results of this study suggest that feeding of GAP at 80 g d,1 with urea-treated rice straw could enhance ruminal propionate production and thus lower C2:C3 ratio, decreasing the protozoal population, as well as increasing N retention and absorption in ruminants. Copyright © 2008 Society of Chemical Industry [source]


    Rga2 is a Rho2 GAP that regulates morphogenesis and cell integrity in S. pombe

    MOLECULAR MICROBIOLOGY, Issue 4 2008
    Ma Antonia Villar-Tajadura
    Summary Schizosaccharomyces pombe Rho2 GTPase regulates ,-D-glucan synthesis and acts upstream of Pck2 to activate the MAP kinase pathway for cell integrity. However, little is known about its regulation. Here we describe Rga2 as a Rho2 GTPase-activating protein (GAP) that regulates cell morphology. rga2+ gene is not essential for growth but its deletion causes longer and thinner cells whereas rga2+ overexpression causes shorter and broader cells. rga2+ overexpression also causes abnormal accumulation of Calcofluor-stained material and cell lysis, suggesting that it also participates in cell wall integrity. Rga2 localizes to growth tips and septum region. The N-terminal region of the protein is required for its correct localization whereas the PH domain is necessary exclusively for Rga2 localization to the division area. Also, Rga2 localization depends on polarity markers and on actin polymerization. Rga2 interacts with Rho2 and possesses in vitro and in vivo GAP activity for this GTPase. Accordingly, rga2, cells contain more ,-D-glucan and therefore partially suppress the thermosensitivity of mok1,664 cells, which have a defective ,-D-glucan synthase. Additionally, genetic interactions and biochemical analysis suggest that Rga2 regulates Rho2,Pck2 interaction and might participate in the regulation of the MAPK cell integrity pathway. [source]


    The Atatürk Dam project in south-east Turkey: Changes in objectives and planning over time

    NATURAL RESOURCES FORUM, Issue 2 2002
    Anna Brismar
    The Atatürk Dam was constructed on the Euphrates River in Turkey in the 1980s as the central component of a large-scale regional development project for the South-eastern Anatolia region, known as GAP. Since the first development plan for the region was presented in 1970, the objectives for regional development have changed significantly. This article aims to analyze how the functions, design, and capacities of the Atatürk Dam project have been modified since 1970, paralleling changes in the regional development objectives and ambitions, and to identify accomplishments and constraints in the realization of the dam project. Since 1970, ambitions to develop the region have grown significantly, resulting in major changes to the original project plans. The most important change occurred in 1978, when the design for the Middle Karababa Dam, recommended in 1970, was abandoned and the Atatürk Dam design was adopted. This change considerably increased the storage and power generation capacities of the dam. Yet, the sparse rainfall throughout the catchment in recent years has hampered full utilization of the dam's storage and generation capacities and increased the need for tradeoffs between conflicting demands for water use. [source]


    THE GAP IS SEMANTIC, NOT EPISTEMOLOGICAL

    RATIO, Issue 2 2007
    Giuseppina D'Oro
    This paper explores an alternative to the metaphysical challenge to physicalism posed by Jackson and Kripke and to the epistemological one exemplified by the positions of Nagel, Levine and McGinn. On this alternative the mind-body gap is neither ontological nor epistemological, but semantic. I claim that it is because the gap is semantic that the mind-body problem is a quintessentially philosophical problem that is not likely to wither away as our natural scientific knowledge advances.1 [source]


    THE EFFECT OF THE COLLECTIVE BARGAINING LEVEL ON THE GENDER WAGE GAP: EVIDENCE FROM SPAIN,

    THE MANCHESTER SCHOOL, Issue 3 2008
    FLORENTINO FELGUEROSO
    Several studies have found a negative relationship between the level of collective bargaining centralization and the degree of wage inequality. So, more centralized bargaining seems to lead to lower wage gaps. On the other hand, there is evidence that the gender wage gap increases as we move upwards along the wage distribution, illustrating the glass ceiling hypothesis. In this paper we study how the wage gap changes throughout the distribution of wages, as a function of the level of collective bargaining by which workers are covered, using data from the Spanish Wage Structure Survey of 2002. [source]


    VIDEOCONFERENCING SURGICAL TUTORIALS: BRIDGING THE GAP

    ANZ JOURNAL OF SURGERY, Issue 4 2008
    Andrew J. A. Holland
    The expansion in medical student numbers has been associated with a move to increase the amount of time students spend in rural and remote locations. Providing an equivalent educational experience for students in surgical subspecialties in this setting is a logistical challenge. We sought to address this issue by providing synchronous tutorials in paediatric surgery using videoconferencing (VC) at two rural sites with the tutor located at a metropolitan paediatric clinical school. Between March 2005 and July 2006, 43 graduate students in the University of Sydney Medical Program were assigned to receive the paediatric component of the course at one of two sites within the School of Rural Health. During this 9-week rotation, students were involved in two or three surgical tutorials by videoconference. Students were then invited to complete a confidential, anonymous 20-point structured evaluation using a Likert scale. Valid responses were received from 40 students, a response rate of 93%. There were 21 females (52%), with 21 students based in Dubbo and 19 in Orange. Students agreed or strongly agreed that VC surgical tutorials were useful, the content well covered and student involvement encouraged (mean scores 4.7, 4.5 and 4.5; standard deviation 0.56, 0.72 and 0.72, respectively). Overall, the majority of students strongly agreed that participation in VC of surgical tutorials was valuable (mean 4.68, standard deviation 0.57). VC surgical tutorials were highly valued by graduate medical students as an educational method. Our data suggest that tutorials can be successfully provided at remote sites using VC. [source]


    IMAGINING A NEW WORLD: USING INTERNATIONALISM TO OVERCOME THE 10/90 GAP IN BIOETHICS

    BIOETHICS, Issue 8 2007
    ALEXANDER MORGAN CAPRON
    ABSTRACT The IAB Presidential Address was delivered by Alexander Capron to the internationally gathered audience at the Closing Ceremony of the 8th World Congress of Bioethics, Beijing on 9th August 2006. [source]


    Engineering of Pichia pastoris for improved production of antibody fragments

    BIOTECHNOLOGY & BIOENGINEERING, Issue 2 2006
    Brigitte Gasser
    Abstract The methylotrophic yeast Pichia pastoris has been used for the expression of many proteins, including antibody fragments. However, limitations became obvious especially when secreting heterodimeric Fab fragments. Up-to-date, antibody fragments have only been expressed under control of the strong inducible alcohol oxidase 1 (AOX1) promoter, which may stress the cells by excessive transcription. Here, we examined the secretion characteristics of single chain and Fab fragments of two different monoclonal anti-HIV1 antibodies (2F5 and 2G12) with both the AOX1 and the glyceraldehyde-3-phosphate dehydrogenase (GAP) promoter. Also, the influences of different secretion leaders and strains were evaluated. Interestingly, secretion was only achieved when using the GAP promoter and the Saccharomyces cerevisiae mating factor , (MF, leader), whereas there was no difference between the two P. pastoris strains. During fed batch fermentation of a 2F5 Fab expressing strain, intracellular retention of Fab heavy chains was observed, while both intact Fab and single light chain molecules were only detected in the supernatants. This led to the conclusion that protein folding and heterodimer assembly in the ER are rate limiting steps in Fab secretion. To alleviate this limitation, S. cerevisiae protein disulfide isomerase (PDI) and the unfolded protein response (UPR) transcription factor HAC1 were constitutively overexpressed in P. pastoris. While the overexpression of HAC1 led to a moderate increase of Fab secretion of 1.3-fold, PDI enabled an increase of the Fab level by 1.9-fold. Hence, the formation of interchain disulfide bonds can be seen as a major rate limiting factor to Fab assembly and subsequent secretion. © 2006 Wiley Periodicals, Inc. [source]


    Protective effects of triamcinolone acetonide upon the upregulation and phosphorylation of GAP 43 in an animal model of retinopathy of prematurity

    ACTA OPHTHALMOLOGICA, Issue 6 2010
    In Y. Chung
    Acta Ophthalmol. 2010: 88: e217,e221 Abstract. Purpose:, The aim of the current study was to investigate the effects of triamcinolone acetonide (TA) upon the expression and phosphorylation of growth-associated protein 43 (GAP 43) in the retinas of oxygen-induced retinopathy (OIR) rats. Methods:, Oxygen-induced retinopathy was induced by exposing Sprague-Dawley rats to hyperoxia (80% oxygen) from postnatal (P) days 2,14 and then returning the rats to normoxic conditions. Triamcinolone acetonide or a conditioned saline (control) was injected intravitreally into the right or left eye, respectively, of OIR rats at P15. We then assessed the molecular and histological changes in the expression of GAP 43 and phospho-GAP 43 in OIR and control rat retinas, and also after treatment with TA by RT-PCR, Western blotting and immunohistochemistry. Results:, Growth-associated protein 43 mRNA levels were found to be increased by 1.6-fold (p = 0.001, n = 5) in the retinas of P18 OIR rats compared with the control rats. The protein levels of GAP 43 and phospho-GAP43 were found to be elevated in the retina of P18 OIR rats (2.40- and 2.39-fold greater than each control, p<0.001, n = 5, respectively). Immunoreactivities of GAP 43 and phospho-GAP 43 were stronger in the inner plexiform layer in OIR rat retinas compared with the control. However, treatment with TA attenuated GAP 43 and phospho-GAP 43 upregulation in the OIR retinas. Conclusion:, Our results indicate that GAP 43 and phospho-GAP 43 participate in retinal (potentially pathologic) changes following oxygen-induced damage. Triamcinolone acetonide protects the retinal damage in relatively hypoxic retinas of OIR rats. Therefore, TA treatment does not induce the expression and phosphorylation of GAP 43 in OIR rat retinas. [source]


    Sam68 is tyrosine phosphorylated and recruited to signalling in peripheral blood mononuclear cells from HIV infected patients

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2005
    S. Najib
    Summary Human immunodeficiency virus (HIV) codes for a protein, Rev, that mediates the viral RNA export from the nucleus to the cytoplasm. Recently, it has been found that Sam68, the substrate of Src associated in mitosis, is a functional homologue of Rev, and a synergistic activator of Rev activity. Thus, it has been suggested that Sam68 may play an important role in the post-transcriptional regulation of HIV. Sam68 contains an RNA binding motif named KH [homology to the nuclear ribonucleoprotein (hnRNP) K]. Tyrosine phosphorylation of Sam68 and binding to SH3 domains have been found to negatively regulate its RNA binding capacity. Besides, tyrosine phosphorylation of Sam68 allows the formation of signalling complexes with other proteins containing SH2 and SH3 domains, suggesting a role in signal transduction of different systems in human lymphocytes, such as the T cell receptor, and leptin receptor, or the insulin receptor in other cell types. In the present work, we have found that Sam68 is tyrosine phosphorylated in peripheral blood mononuclear cells (PBMC) from HIV infected subjects, leading to the formation of signalling complexes with p85 the regulatory subunit of PI3K, GAP and STAT-3, and decreasing its RNA binding capacity. In contrast, PBMC from HIV infected subjects have lower expression levels of Sam68 compared with controls. These results suggest that Sam68 may play some role in the immune function of lymphocytes in HIV infection. [source]