Full Stokes polarimetry with the Effelsberg 100-m radio telescope

The first part of this thesis is dedicated to the development of a new calibration procedure that allows full Stokes measurements with the Effelsberg antenna. After introducing some basic concepts and definitions of polarimetry (Ch. 2), we have studied in detail the instrumental noise that a single-dish radio telescope adds to the polarimetric signal once this has been received (Ch. 3), analysing each part of the receiving chain. Focusing on the aberration introduced by the most common radioastronomical receiver, we have derived the degradation in its mathematical formalism, computing the instrumental Müller matrix of the telescope, in order to derive the corrections to be applied to recover the original information carried out by the signal, along with the treatment of the errors during the process (Ch. 4). The theoretical study of the full Stokes calibration has been followed by a 1-year test phase, carried out with the 5 GHz receiver (one of the most accurate available at Effelsberg). The results of the test phase, along with the comparison of our results with those obtained by the 26-m telescope of the University of Michigan (the only one single-dish telescope that carried out circular polarization measurements, before this PhD work) are presented in Ch. 5. The second part is dedicated to the full polarimetric survey carried out by the Effelsberg and Westerbork telescopes on 257 sources from the 1-Jy catalogue at 5 GHz. The technical characteristics of the survey are presented in Ch. 6. Once we have completed the data calibration for all the measurements (the complete results are listed in Appendix A), we have carried out some statistical tests, aimed to describe the behaviour of circular polarization according to the main source properties (optical classification, redshift, linear polarization, two-point spectral index, see Ch. 7). Finally, we have extended the calibration procedure to more frequencies, acquiring, for the first time at Effelsberg, the full Stokes spectra of a sample of sources, that appeared circularly polarized from the 5 GHz survey. The spectra are included in Appendix B for future reference. Ch. 8 contains the first results obtained from the comparison of the observed spectra with the theoretical ones, giving an outlook of the possible scientific results achievable with this new technique

Web accessibility in the Dynamic Hypermedia Device theoretical and methodological framework: about the case Memoria y Experiencia Cossettini

El artículo presenta los avances de desarrollo del Dispositivo Hipermedial Dinámico “Memoria y Experiencia Cossettini”, en referencia al abordaje teórico y metodológico de problemáticas de accesibilidad web donde se tratan diferentes postulados sobre discapacidad y diversidad funcional. La metodología del desarrollo se fundamentó bajo el enfoque socio-técnico atendiendo a la perspectiva sistémica compleja en la construcción de redes sociales mediatizadas. Sobre la metodología de evaluación de accesibilidad web se adoptaron los estándares internacionales propuestos por la Web Accesibility Initiative (WAI). Luego de la identificación de los requerimientos prioritarios a ser resueltos, se discuten las soluciones propuestas por la WAI en referencia a la ausencia de considerar otras formas alternativas de producción de significantes con diferentes lenguajes expresivos. Finalmente, se concluye que el abordaje socio-técnico permite una co-construcción inclusiva, abierta y plural de este tipo de dispositivos, habilitada en el compromiso responsable de todos y cada uno de los participantes a modo de “Conciencia Ética” que sostiene una vigilancia constante en relación a la AlteridadThe article presents the progress in the development of the Dynamic Hypermedia Device “Memory and Experience Cossettini” referring to the theoretical and methodological approach to web accessibility issues and considering different assumptions about disability and functional diversity. The general methodology of development was based on the socio-technical approach considering the complex systems’s perspective in the construction of mediated social networks. Specifically talking, international standards proposed by the Web Accessibility Initiative (WAI) were adopted on the web methodology of accessibility evaluation. After identifying priority needs to be solved, there is a discussion about solutions proposed by the WAI refering to the absence of consideration of alternative ways of producing significants with different expressive languages. Finally, we arrive to the conclusion that the socio-technical approach allows an inclusive, open and pluralistic co-construction of these devices, enabled due to the responsible commitment of each and every one of the participants as an “Ethics Awareness” which applies constant vigilance in relation to the OthernessFil: Cenacchi, Marisa Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación. Universidad Nacional de Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educacion; Argentina. Universidad Nacional de Rosario; Argentin

Deriving AGN properties from radio CP and LP

We report multi-frequency circular polarization measurements for the radio source 0056-00 taken at the Effelsberg 100-m radiotelescope. The data reduction is based on a new calibration procedure that allows the contemporary measurement of the four Stokes parameters with single-dish radiotelescopesComment: 2 pages, Proceeding of "IAU Symposium No.259. Cosmic Magnetic Fields from planets, to stars and galaxies

Emerging Tumor Entities and Variants of CNS Neoplasms

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XAV939-mediated ARTD activity inhibition in human MB cell lines

Diphtheria toxin-like ADP-ribosyltransferases 1 and 5 (ARTD-1, ARTD-5) are poly ADP-ribose enzymes (PARP) involved in non-homologous end-joining (NHEJ), which is the major pathway of double-strand break (DSB) repair. In addition, ARTD-5, or Tankyrase (TNKS), is a positive regulator of the WNT signaling implicated in the development and biological behavior of many neoplasms, such as Medulloblastoma (MB), in which radiotherapy is an essential part of the treatment. The use of radiosensitizing agents may improve the therapeutic index in MB patients by increasing the efficacy of radiotherapy, while reducing toxicity to the neuroaxis. ARTD-5 seems to be a good molecular target for improving the current treatment of MB. In this study, we used the small molecule XAV939, a potent ARTD-5 inhibitor with a slight affinity for ARTD-1, in different human MB cell lines. XAV939 inhibited the WNT pathway and DNA-PKcs in our MB cells, with many biological consequences. The co-administration of XAV939 and ionizing radiations (IR) inhibited MB cells proliferation and clonogenic capacity, decreased their efficacy in repairing DNA damage, and increased IR-induced cell mortality. In conclusion, our in vitro data show that XAV939 could be a very promising small molecule in MB treatment, and these results lay the basis for further in vivo studies with the aim of improving the current therapy available for MB patients

La accesibilidad web en el marco teórico y metodológico del Dispositivo Hipermedial Dinámico: acerca del caso Memoria y Experiencia Cossettini

El artículo presenta los avances de desarrollo del Dispositivo Hipermedial Dinámico “Memoria y Experiencia Cossettini”, en referencia al abordaje teórico y metodológico de problemáticas de accesibilidad web donde se tratan diferentes postulados sobre discapacidad y diversidad funcional. La metodología del desarrollo se fundamentó bajo el enfoque socio-técnico atendiendo a la perspectiva sistémica compleja en la construcción de redes sociales mediatizadas. Sobre la metodología de evaluación de accesibilidad web se adoptaron los estándares internacionales propuestos por la Web Accesibility Initiative (WAI). Luego de la identificación de los requerimientos prioritarios a ser resueltos, se discuten las soluciones propuestas por la WAI en referencia a la ausencia de considerar otras formas alternativas de producción de significantes con diferentes lenguajes expresivos. Finalmente, se concluye que el abordaje socio-técnico permite una co-construcción inclusiva, abierta y plural de este tipo de dispositivos, habilitada en el compromiso responsable de todos y cada uno de los participantes a modo de “Conciencia Ética” que sostiene una vigilancia constante en relación a la Alteridad

Ignitor: Physics and Progress Towards Ignition

Thermonuclear ignition condition for deuterium-tritium plasmas can be achieved in compact, high magnetic field devices such as Ignitor. The main scientific goals, the underlying physics basis, and the most relevant engineering solutions of this experiment are described. Burning plasma conditions can be reached either with ohmic heating only or with small amount of auxiliary power in the form of ICRH waves, and this condition can be sustained for a time considerably longer than all the relevant plasma time scales. In the reference operating scenario, no transport barriers are present, and the resulting thermal loads on the plasma facing component are estimated to be rather modest, thanks to the high edge density and low edge temperature that ensure an effective intrinsic radiating mantle in elongated limiter configurations. Enhanced confinement regimes can also be obtained in configurations with double X-points near the first wall

Modelos, discursos y perspectivas teóricas vigentes sobre discapacidad y deficiencia

La discapacidad constituye un campo multidimensional complejo, atravesado por diversos discursos y teorías que han caracterizado a las formas de nombrar y conceptualizar a la alteridad deficiente en el tiempo. Considerando que los discursos construyen los objetos e influyen en los patrones de respuesta que se derivan o se implican en ellos, se presenta necesario deconstruir los conceptos heredados sobre dicho colectivo para habilitar la reflexión crítica sobre la vigencia explícita y/o implícita en los contextos educativos actuales y sus implicancias. En esta dirección, se presentan los principales modelos históricos y perspectivas teóricas críticas más significativas que abonan el campo. Si bien hay consenso en concebir a la discapacidad como una construcción social, se observan divergencias en la conceptualización de las deficiencias. Aún desde el modelo social, se sostiene una división teórica entre discapacidad y deficiencia que mantiene vigente el modelo médico, el concepto de déficit y su contracara, la normalidad. Por el contrario, diversas perspectivas críticas sustentadas en los estudios culturales, feministas, poscoloniales y teorías posmodernas, proponen suprimir esa división binaria y concebir también a la deficiencia como socialmente construida

Climate smart agriculture and global food-crop production

Most business-as-usual scenarios for farming under changing climate regimes project that the agriculture sector will be significantly impacted from increased temperatures and shifting precipitation patterns. Perhaps ironically, agricultural production contributes substantially to the problem with yearly greenhouse gas (GHG) emissions of about 11% of total anthropogenic GHG emissions, not including land use change. It is partly because of this tension that Climate Smart Agriculture (CSA) has attracted interest given its promise to increase agricultural productivity under a changing climate while reducing emissions. Considerable resources have been mobilized to promote CSA globally even though the potential effects of its widespread adoption have not yet been studied. Here we show that a subset of agronomic practices that are often included under the rubric of CSA can contribute to increasing agricultural production under unfavorable climate regimes while contributing to the reduction of GHG. However, for CSA to make a significant impact important investments and coordination are required and its principles must be implemented widely across the entire sector