536 research outputs found

    Role of CD56 in Normal Kidney Development and Wilms Tumorigenesis

    Get PDF
    The cell-surface glycoprotein CD56 has three major isoforms that play important roles in cell adhesion and signaling, which may promote cell proliferation, differentiation, survival, or migration. It is an important molecule in normal kidney development and acts as a key marker in Wilms tumor stem and progenitor cells. Here, we review the structural and genetic features of the CD56 glycoprotein, and summarize its roles in the normal versus diseased metanephric blastema. We discuss areas of CD56-related research that may complement or improve existing Wilms tumor treatment strategies, including the antibody-drug conjugate lorvotuzumab mertansine that binds to CD56

    Criterios de calidad y evaluación: un instrumento de medición para el área de la lengua alemana

    Full text link
    La Xarxa Universitària sobre Responsabilitat Social és una xarxa de més de 40 universitats d'Alemanya i Àustria establerta el 2009 que volen fer realitat i ampliar la seva responsabilitat social promovent sistemàticament la participació a la societat civil d'estudiants, professors i altres membres universitaris, vinculant-ho amb la seva missió educativa per influir activament en la societat i contribuir a la transferència mútua de coneixements. L'aprenentatge servei (ApS) és una manera de fer-ho. El 2018, un taller va iniciar una discussió entre representants del món acadèmic i de la societat civil. El focus era analitzar els criteris de qualitat de l’ApS. El grup va plantejar deu criteris diferents que proporcionen un marc de referència per a les diferents manifestacions de l’ApS a la comunitat. A partir d'aquests criteris, es van desenvolupar procediments i instruments adequats per oferir als actors orientació i suggeriments per a la implementació i avaluació dels projectes d’ApS.The University Network on Social Responsibility is a network of more than 40 universities in Germany and Austria established in 2009 that want to realise and expand their social responsibility by systematically promoting the civil society engagement of students, teachers, and other members of higher education, linking this with their educational mission and thus actively influencing society and contributing to the mutual transfer of knowledge. This can be done through the teaching-learning format of service learning (SL). In 2018, a workshop initiated a discussion between representatives of academia and civil society. The focus was the aspect of quality of SL. The group came up with ten different criteria which provide a frame of reference for the different manifestations of SL in the community. Based on these criteria, suitable procedures and instruments were developed to provide SL actors with orientation and suggestions for the implementation and evaluation of SL projects.La Red Universitaria sobre Responsabilidad Social es una red de más de 40 universidades en Alemania y Austria, establecida en 2009, que desean realizar y expandir su responsabilidad social promoviendo sistemáticamente la participación de la sociedad civil de estudiantes, docentes y otros miembros universitarios, vinculando con su misión educativa para influir activamente en la sociedad y contribuir a la transferencia mutua de conocimientos. Ello se puede hacer a través del aprendizaje-servicio (ApS). En 2018, un taller inició un debate entre representantes de la academia y la sociedad civil. El foco fue los aspectos de calidad del ApS. El grupo ideó diez criterios diferentes que proporcionan un marco de referencia para las diferentes manifestaciones de ApS en la comunidad. Con base en estos criterios, se desarrollaron procedimientos e instrumentos adecuados para proporcionar a los actores orientación y sugerencias para la implementación y evaluación de proyectos de ApS

    A Supermassive Black Hole in an Ultracompact Dwarf Galaxy

    Full text link
    Ultracompact dwarf galaxies (UCDs) are among the densest stellar systems in the universe. These systems have masses up to 200 million solar masses, but half light radii of just 3-50 parsecs. Dynamical mass estimates show that many UCDs are more massive than expected from their luminosity. It remains unclear whether these high dynamical mass estimates are due to the presence of supermassive black holes or result from a non-standard stellar initial mass function that causes the average stellar mass to be higher than expected. Here we present the detection of a supermassive black hole in a massive UCD. Adaptive optics kinematic data of M60-UCD1 show a central velocity dispersion peak above 100 km/s and modest rotation. Dynamical modeling of these data reveals the presence of a supermassive black hole with mass of 21 million solar masses. This is 15% of the object's total mass. The high black hole mass and mass fraction suggest that M60-UCD1 is the stripped nucleus of a galaxy. Our analysis also shows that M60-UCD1's stellar mass is consistent with its luminosity, implying many other UCDs may also host supermassive black holes. This suggests a substantial population of previously unnoticed supermassive black holes.Comment: Author's version of paper appearing in 18 September issue of Nature, available at http://dx.doi.org/10.1038/nature13762 ; 9 pages, 9 figures including methods & supplementary information section

    Deviations from the local field approximation in negative streamer heads

    Get PDF
    Negative streamer ionization fronts in nitrogen under normal conditions are investigated both in a particle model and in a fluid model in local field approximation. The parameter functions for the fluid model are derived from swarm experiments in the particle model. The front structure on the inner scale is investigated in a 1D setting, allowing reasonable run-time and memory consumption and high numerical accuracy without introducing super-particles. If the reduced electric field immediately before the front is >= 50kV/(cm bar), solutions of fluid and particle model agree very well. If the field increases up to 200kV/(cm bar), the solutions of particle and fluid model deviate, in particular, the ionization level behind the front becomes up to 60% higher in the particle model while the velocity is rather insensitive. Particle and fluid model deviate because electrons with high energies do not yet fully run away from the front, but are somewhat ahead. This leads to increasing ionization rates in the particle model at the very tip of the front. The energy overshoot of electrons in the leading edge of the front actually agrees quantitatively with the energy overshoot in the leading edge of an electron swarm or avalanche in the same electric field.Comment: The paper has 17 pages, including 15 figures and 3 table

    Gescheiden afvoer van vaste mest en urine in combinatie met spoelen

    Get PDF
    Gescheiden afvoer van vaste mest en urine uit de stal leidt tot een vermindering van de ammoniakemissie. In een onderzoek van het Praktijkonderzoek Varkenshouderij leidde een dergelijke mestafvoer in combinatie met spoelen en een daarop volgende mestscheiding tot technische problemen

    Barred Galaxies in the Coma Cluster

    Full text link
    We use ACS data from the HST Treasury survey of the Coma cluster (z~0.02) to study the properties of barred galaxies in the Coma core, the densest environment in the nearby Universe. This study provides a complementary data point for studies of barred galaxies as a function of redshift and environment. From ~470 cluster members brighter than M_I = -11 mag, we select a sample of 46 disk galaxies (S0--Im) based on visual classification. The sample is dominated by S0s for which we find an optical bar fraction of 47+/-11% through ellipse fitting and visual inspection. Among the bars in the core of the Coma cluster, we do not find any very large (a_bar > 2 kpc) bars. Comparison to other studies reveals that while the optical bar fraction for S0s shows only a modest variation across low-to-intermediate density environments (field to intermediate-density clusters), it can be higher by up to a factor of ~2 in the very high-density environment of the rich Coma cluster core.Comment: Proceedings of the Bash symposium, to appear in the Astronomical Society of the Pacific Conference Series, eds. L. Stanford, L. Hao, Y. Mao, J. Gree

    Kinetic simulation of an extreme ultraviolet radiation driven plasma near a multilayer mirror

    Get PDF
    Future generation lithog. tools will use extreme UV radiation to enable the printing of sub-50 nm features on silicon wafers. The extreme UV radiation, coming from a pulsed discharge, photoionizes the low pressure background gas in the tool. A weakly ionized plasma is formed, which will be in contact with the optical components of the lithog. device. In the plasma sheath region ions will be accelerated towards the surfaces of multilayer mirrors. A self-consistent kinetic particle-in-cell model has been applied to describe a radiation driven plasma. The simulations predict the plasma parameters and notably the energy at which ions impact on the plasma boundaries. We have studied the influence of photoelectron emission from the mirror on the sheath dynamics and on the ion impact energy. Furthermore, the ion impact energy distribution has been convoluted with the formula of Yamamura and Tawara [At. Data Nucl. Data Tables 62, 149 (1996)] for the sputter yield to obtain the rate of phys. sputtering. The model predicts that the sputter rate is dominated by the presence of doubly ionized argon ions. [on SciFinder (R)
    corecore