El juez constitucional: un actor regulador de las políticas públicas. El caso de la descentralización en Colombia

El juez constitucional es motivo de apasionados debates tanto por quienes defienden su actividad en tanto expresión constitucional de la democracia como por quienes lo atacan por poner en peligro la separación tradicional de los poderes públicos. Sin embargo una nueva dimensión de su actividad emerge en medio de la re definición de los conceptos jurídicos y políticos que fundan la noción del Estado. Las políticas Públicas hasta hace muy poco eran competencia exclusiva de la administración sin embargo el juez constitucional ha ido consolid?ndose como un actor capaz de determinar sus contornos desarrollando un concepto amplio de gobernanza que va más allá de la idea de gobierno y de gobernabilidad. Entonces esta investigación está orientada a presentar tanto a juristas politólogos y administradores el proceso mediante el cual el sistema jurídico constitucional regula el sistema de políticas públicas y en este caso la política territorial para buscar demostrar cómo una nueva dimensión del control constitucional se consolida dentro de una nueva idea Estado y de democracia.

La fecundidad en América Latina: ¿transición o revolución?

Incluye Bibliografía

Atomic-scale characterization of diamond surfaces and fullerene self-assembly

In this thesis, elemental research towards the implantation of a diamond-based molecular quantum computer is presented. The approach followed requires linear alignment of endohedral fullerenes on the diamond C(100) surface in the vicinity of subsurface NV-centers. From this, four fundamental experimental challenges arise: 1) The well-controlled deposition of endohedral fullerenes on a diamond surface. 2) The creation of NV-centers in diamond close to the surface. 3) Preparation and characterization of atomically-flat diamondsurfaces. 4) Assembly of linear chains of endohedral fullerenes. First steps to overcome all these challenges were taken in the framework of this thesis. Therefore, a so-called “pulse injection” technique was implemented and tested in a UHV chamber that was custom-designed for this and further tasks. Pulse injection in principle allows for the deposition of molecules from solution onto a substrate and can therefore be used to deposit molecular species that are not stable to sublimation under UHV conditions, such as the endohedral fullerenes needed for a quantum register. Regarding the targeted creation of NV-centers, FIB experiments were carried out in cooperation with the group of Prof. Schmidt-Kaler (AG Quantum, Physics Department, Johannes Gutenberg-Universität Mainz). As an entry into this challenging task, argon cations were implanted into (111) surface-oriented CaF2 crystals. The resulting implantation spots on the surface were imaged and characterized using AFM. In this context, general relations between the impact of the ions on the surface and their valency or kinetic energy, respectively, could be established. The main part of this thesis, however, is constituted by NCAFM studies on both, bare and hydrogen-terminated diamond C(100) surfaces. In cooperation with the group of Prof. Dujardin (Molecular Nanoscience Group, ISMO, Université de Paris XI), clean and atomically-flat diamond surfaces were prepared by exposure of the substrate to a microwave hydrogen plasma. Subsequently, both surface modifications were imaged in high resolution with NC-AFM. In the process, both hydrogen atoms in the unit cell of the hydrogenated surface were resolved individually, which was not achieved in previous STM studies of this surface. The NC-AFM images also reveal, for the first time, atomic-resolution contrast on the clean, insulating diamond surface and provide real-space experimental evidence for a (2×1) surface reconstruction. With regard to the quantum computing concept, high-resolution NC-AFM imaging was also used to study the adsorption and self-assembly potential of two different kinds of fullerenes (C60 and C60F48) on aforementioned diamond surfaces. In case of the hydrogenated surface, particular attention was paid to the influence of charge transfer doping on the fullerene-substrate interaction and the morphology emerging from self-assembly. Finally, self-assembled C60 islands on the hydrogen-terminated diamond surface were subject to active manipulation by an NC-AFM tip. Two different kinds of tip-induced island growth modes have been induced and were presented. In conclusion, the results obtained provide fundamental informations mandatory for the realization of a molecular quantum computer. In the process it was shown that NC-AFM is, under proper circumstances, a very capable tool for imaging diamond surfaces with highest resolution, surpassing even what has been achieved with STM up to now. Particular attention was paid to the influence of transfer doping on the morphology of fullerenes on the hydrogenated diamond surface, revealing new possibilities for tailoring the self-assembly of molecules that have a high electron affinity.

Images rhétoriques & visions de l'Univers dans la vulgarisation scientifique

Cette thèse a pour objectif premier d’analyser les images rhétoriques (procédant par analogie) contenues dans un corpus d’ouvrages de vulgarisation scientifique ayant trait à la physique (astrophysique et physique quantique). Privilégiant une optique pluridisciplinaire, cet ouvrage s’applique à constituer - puis démontrer - l’extrême importance de ce cadre référentiel. Cette étude met également en lumière la caractéristique essentielle de la vulgarisation francophone, tout en insistant sur la nécessité de développer l’entreprise de vulgarisation scientifique. Les différentes visions proposées par les scientifiques eux-mêmes concernant notre monde, la valeur de leur imagerie ou de la composante épistémologique dans tout acte de connaissance font également partie intégrante de cette «réflexion», «véritable» reflet de notre savoir.