167 research outputs found

    Rafael Núñez. Clave de una figura clave

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    Hace más de 25 años se preparaba la nación, o debía prepararse al menos, para conmemorar algunos aniversarios. Entre otros los de Santander, Núñez y Miguel Antonio Caro. Como de costumbre la clase dirigente llegó "improvisada" a tales aniversarios. Y el público, en general, no sentía frío ni calor en torno a Santander, de Núñez o de Caro, porque no estaba obligado a conocer la historia de estos personajes que sí debía conocer la clase dirigente pero que también ignoraba

    The Chronicle [September 20, 1988]

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    The Chronicle, September 20, 1988https://repository.stcloudstate.edu/chron/3704/thumbnail.jp

    The Ledger and Times, April 29, 1964

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    The Ledger and Times, April 29, 1964

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    Role of the β-propeller domain of low-density lipoprotein receptor in human rhinovirus infection

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    Drei Vertreter der low-density Lipoprotein Rezeptor Familie, LDLR selbst, very-LDLR, und LDLR related protein (LRP) werden von minor group Rhinoviren des Menschen (HRVs) als Rezeptoren verwendet. Während ICAM-1, der Rezeptor der major group der HRVs, aktiv am viralen uncoating beteiligt ist, wurden minor group Rezeptoren als passive Vehikel betrachtet, die das Virus in Endosomen transportieren, wo sie ein Milieu mit niedrigem pH vorfinden. Für die YWTD β-Propeller Domaine des LDL-Rezeptors wurde jedoch gezeigt, dass sie an der Abdissoziation gebundenen LDLs bei niedrigem pH beteiligt ist. Wir wollten daher herausfinden, ob sie auch aktiv an der Infektion mit HRVs teilnimmt. Es existiert keine humane Zell Linie, die LDLR in Abwesenheit von VLDLR oder LRP exprimiert. Daher wurden in unseren Untersuchungen CHO-ldla7 Zellen verwendet, die keinen endogenen LDL-Rezeptor exprimieren. Diese waren stabil transfiziert um entweder Wildtyp oder β-Propeller negative humane LDL-Rezeptoren zu exprimieren. Mit Hilfe dieser Zellen untersuchten wir den möglichen Einfluss des β-Propellers auf die Konversion von HRV2 in subvirale Partikel als eine Funktion des niedrigen pH und die Freisetzung des Virus vom Rezeptor. Wenn HRV2 an propeller-negativen LDLR gebunden war ein niedrigerer pH wurde für die Konversion benötigt. Dies deutet darauf hin, dass die hoch-avide Rezeptorbindung das Virus in seiner nativen Konformation stabilisiert. Infektionsversuche zeigten eine zeitliche Verzögerung in der intrazellulären viralen Konversion, im Abbau und in der viralen de novo Synthese in der Abwesenheit der β-Propeller-Domaine. Wir schließen daraus, dass die Funktion des β-Propellers bei niedrigem pH auch dann signifikant ist, wenn der Ligand ein Rhinovirus ist. Er erleichtert die virale Konversion im Inneren von Endosomen, indem er den Virus-stabilisierenden Effekt des mit hoher Avidität bindenden LDLR reduziert. Dadurch begünstigt er die Infektion.Three members of the low-density lipoprotein receptor (LDLR) family, LDLR proper, very-LDLR (VLDLR) and LDLR-related protein (LRP) act as minor group human rhinovirus (HRV) receptors. Whereas ICAM-1, the receptor of the major group of HRVs, actively contributes to viral uncoating, minor group receptors were rather considered passive vehicles just delivering virus to the low pH environment of endosomes. However, the YWTDβ-propeller domain of LDLR has been shown to be involved in the dissociation of bound LDL at acidic pH. We thus aimed to clarify whether it also actively contributes to HRV infection. No human cell line expressing LDLR in the absence of VLDLR or LRP is available. Therefore, CHO-ldla7 cells which are deficient in endogenous LDLR and are stably transfected to express either wild-type or β-propeller negative human LDLR were used to investigate low pH-triggered conversion of HRV2 and its release from the receptor. Lower pH was required for conversion when HRV2 was attached to the propeller-negative LDLR, indicating that the high-avidity receptor-binding stabilizes the virus in its native conformation. Infection assays showed a delay in intracellular viral conversion, degradation, as well as in de novo viral synthesis in the absence of the β-propeller domain. We conclude that the function of the β-propeller at low pH is also significant when the ligand is a rhinovirus; it facilitates viral conversion within endosomes by decreasing the virus-stabilizing effect of the high avidity LDLR binding, and thereby promotes infection

    Youth employment in the Cape Town area: Insights from the Cape Area Panel Study

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    Includes bibliographical references (leaves 37-39).In South Africa today, one of the most urgent economic, social and political challenges is the extraordinarily high and increasing level of unemployment. While the economy has been growing steadily, unemployment levels have continued to rise. A large part of the problem is the fact that the number of new entrant~ outstrips the creation of new jobs (Ashton, 2005; Chichelo et aI., 2003). Since most of the new entrants are people making the transition from school and other education institutions into the labour market, it is not surprising that the problem of unemployment is more severe among the youth. Young people as a group are disproportionately affected by unemployment - whereas the unemployment level for adults is in the region of 26%, the rate for youth is 50%, while 58% of the unemployed are young people (Mlatsheni & Rosphabe, 2002). This paper looks at the factors that affect employment among the youth in the Cape Town area. Using data from the 2002 and 2004 waves of the Cape Area Panel Study, cross-sectional and panel probit regressions have been employed to investigate the role of individual, household and schooling characteristics in the probability of employment. The results suggest that although household income and the presence of employed people in the household were important in a cross-sectional setting, previous labour market experiences were more important in a dynamic setting. While quantity of schooling is found to be very import ant, the impact of quality of schooling could not be determined. The usual race and gender patterns in employment were found

    Relief of Residual Stress in Streamline Tie Rods by Heat Treatment

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    About two-thirds of the residual stress in cold-worked SAE 1050 steel tie rods was relieved by heating 30 minutes at 600 degrees Fahrenheit. Cold-worked austenitic stainless-steel tie rods could be heated at temperatures up to 1000 degrees Fahrenheit without lowering the important physical properties. The corrosion resistance, in laboratory corrosion test, of straight 18:8 and titanium-treated 18:8 materials appeared to be impaired after heating at temperatures above 800 degrees or 900 degrees fahrenheit. Columbium-treated and molybdenum-treated 18:8 steel exhibited improved stability over a wide range of temperatures. Tie rods of either material could be heated 30 minutes with safety at any temperature up to 1000 degrees Fahrenheit. At this temperature most of the residual stress would be relieved

    An improved model of the Earth's gravitational field: GEM-T1

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    Goddard Earth Model T1 (GEM-T1), which was developed from an analysis of direct satellite tracking observations, is the first in a new series of such models. GEM-T1 is complete to degree and order 36. It was developed using consistent reference parameters and extensive earth and ocean tidal models. It was simultaneously solved for gravitational and tidal terms, earth orientation parameters, and the orbital parameters of 580 individual satellite arcs. The solution used only satellite tracking data acquired on 17 different satellites and is predominantly based upon the precise laser data taken by third generation systems. In all, 800,000 observations were used. A major improvement in field accuracy was obtained. For marine geodetic applications, long wavelength geoidal modeling is twice as good as in earlier satellite-only GEM models. Orbit determination accuracy has also been substantially advanced over a wide range of satellites that have been tested

    A NASTRAN model of a large flexible swing-wing bomber. Volume 3: NASTRAN model development-wing structure

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    The NASTRAN model plan for the wing structure was expanded in detail to generate the NASTRAN model for this substructure. The grid point coordinates were coded for each element. The material properties and sizing data for each element were specified. The wing substructure model was thoroughly checked out for continuity, connectivity, and constraints. This substructure was processed for structural influence coefficients (SIC) point loadings and the deflections were compared to those computed for the aircraft detail model. Finally, a demonstration and validation processing of this substructure was accomplished using the NASTRAN finite element program. The bulk data deck, stiffness matrices, and SIC output data were delivered
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