529 research outputs found

    Gene Therapy of Bone Morphogenetic Protein for Periodontal Tissue Engineering

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141217/1/jper0202.pd

    First direct measurements of hydraulic jumps in an active submarine density current

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    For almost half a century, it has been suspected that hydraulic jumps, which consist of a sudden decrease in downstream velocity and increase in flow thickness, are an important feature of submarine density currents such as turbidity currents and debris flows. Hydraulic jumps are implicated in major seafloor processes, including changes from channel erosion to fan deposition, flow transformations from debris flow to turbidity current, and large-scale seafloor scouring. We provide the first direct evidence of hydraulic jumps in a submarine density current and show that the observed hydraulic jumps are in phase with seafloor scours. Our measurements reveal strong vertical velocities across the jumps and smaller than predicted decreases in downstream velocity. Thus, we demonstrate that hydraulic jumps need not cause instantaneous and catastrophic deposition from the flow as previously suspected. Furthermore, our unique data set highlights problems in using depth-averaged velocities to calculate densimetric Froude numbers for gravity currents

    On the structure and evolution of a polar crown prominence/filament system

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    Polar crown prominences are made of chromospheric plasma partially circling the Suns poles between 60 and 70 degree latitude. We aim to diagnose the 3D dynamics of a polar crown prominence using high cadence EUV images from the Solar Dynamics Observatory (SDO)/AIA at 304 and 171A and the Ahead spacecraft of the Solar Terrestrial Relations Observatory (STEREO-A)/EUVI at 195A. Using time series across specific structures we compare flows across the disk in 195A with the prominence dynamics seen on the limb. The densest prominence material forms vertical columns which are separated by many tens of Mm and connected by dynamic bridges of plasma that are clearly visible in 304/171A two-color images. We also observe intermittent but repetitious flows with velocity 15 km/s in the prominence that appear to be associated with EUV bright points on the solar disk. The boundary between the prominence and the overlying cavity appears as a sharp edge. We discuss the structure of the coronal cavity seen both above and around the prominence. SDO/HMI and GONG magnetograms are used to infer the underlying magnetic topology. The evolution and structure of the prominence with respect to the magnetic field seems to agree with the filament linkage model.Comment: 24 pages, 14 figures, Accepted for publication in Solar Physics Journal, Movies can be found at http://www2.mps.mpg.de/data/outgoing/panesar

    Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs

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    We present a determination of the gluon polarization Delta G/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q^2<1(GeV/c)^2, with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a polarized 6-LiD target. The helicity asymmetry for the selected events is = 0.002 +- 0.019(stat.) +- 0.003(syst.). From this value, we obtain in a leading-order QCD analysis Delta G/G=0.024 +- 0.089(stat.) +- 0.057(syst.) at x_g = 0.095 and mu^2 =~ 3 (GeV}/c)^2.Comment: 10 pages, 3 figure

    Measurement of the Spin Structure of the Deuteron in the DIS Region

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    We present a new measurement of the longitudinal spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron in the range 1 GeV^2 < Q^2 < 100 GeV^2 and 0.004< x <0.7. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarised muon beam and a large polarised 6-LiD target. The results are in agreement with those from previous experiments and improve considerably the statistical accuracy in the region 0.004 < x < 0.03.Comment: 10 pages, 6 figures, subm. to PLB, revised: author list, Fig. 4, details adde

    Formación docente para la implementación de la plataforma virtual Moodle como recurso didáctico en educación básica secundaria

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    1 recurso en línea (288 páginas) : ilustraciones color, tablas.Este estudio describe una experiencia llevada a cabo en entornos virtuales de aprendizaje Moodle, donde se planteó la utilización de la Educación Virtual como recurso didáctico educativo. A partir de un proceso de formación docente para la implementación de la plataforma virtual Moodle como recurso didáctico de enseñanza, se analizó si se presentaron cambios significativos en las competencias digitales: Pedagógica, tecnológica, comunicativa y de gestión, y a partir de ello se mejoró el desempeño pedagógico de los educadores; de igual forma se indago sobre la posibilidad de que las plataformas virtuales como Moodle puedan convertirse en una alternativa viable que pueda dar respuesta a los nuevos retos educativos relacionados con los ambientes virtuales de aprendizaje para dinamizar el proceso educativo. Como objetivo general del estudio se planteó Identificar las competencias digitales que poseen los docentes para el uso y administración de la plataforma Moodle, en el nivel de educación básica secundaria y media de la Institución Educativa Técnica de Monguí, para implementar un programa de formación encaminado a fortalecer dichas competencias. La metodología empleada en el estudio fue de tipo mixto, porque involucra aspectos cuantitativos como la medición de las variable competencias digitales desarrolladas por los docentes para el empleo de la plataforma virtual Moodle, desde el paradigma cualitativo se tuvieron en cuenta las opiniones y conceptos de los sujetos participantes en el estudio; de los resultados obtenidos se encontró que los programas de formación docente para el uso didáctico de las TIC en entornos de aprendizaje virtual como la plataforma Moodle, cuando son orientados con un modelo pedagógico activo diferente al catedrático, permiten que los educadores apropien el uso de estas tecnologías y sean gestores de proyectos que dinamizan el proceso enseñanza – aprendizaje, al brindar al estudiante la posibilidad de ser un agente participativo y por su puesto al educador ser guía y orientador en el proceso educativo.This study describes an experience carried out in Moodle virtual learning environments, where the use of Virtual Education as an educational didactic resource was proposed. From a process of teacher training for the implementation of the Moodle virtual platform as a didactic teaching resource, it was analyzed if there were significant changes in the digital competences: Pedagogical, technological, communicative and management, and from this the pedagogical performance of educators; In the same way, I inquired about the possibility that virtual platforms such as Moodle could become a viable alternative that could respond to new educational challenges related to virtual learning environments to boost the educational process. The general objective of the study was to identify the digital competences that teachers possess for the use and administration of the Moodle platform, at the level of secondary and secondary education of the Technical Educational Institution of Monguí, to implement a training program aimed at strengthen these competences The methodology used in the study was of mixed type, because it involved quantitative aspects such as the measurement of the variable digital competences developed by teachers for the use of the Moodle virtual platform, from the qualitative paradigm the opinions and concepts of the subjects participating in the study; From the results obtained it was found that the teacher training programs for the didactic use of ICT in virtual learning environments such as the Moodle platform, when they are oriented with an active pedagogical model different from the professor, allow educators to appropriate the use of these technologies and managers of projects that dynamize the teaching - learning process, giving the student the possibility of being a participative agent and of course the educator being a guide and guidance in the educational process.Bibliografía y webgrafía: páginas 196-205MaestríaMagíster en TIC Aplicadas a las Ciencias de la Educació
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