Roughening of cobalt thin films on sapphire (110) upon annealing and superparamagnetic behavior of cobalt nanodots on sapphire (001)

Atomic force microscopy (AFM) was employed to investigate the surface roughness of 5.0 nm thick Co films as a function of the annealing temperature. Films were epitaxially grown on (110) sapphire via molecular beam epitaxy (MBE) and magnetron sputtering. Images were acquired in-situ at temperatures ranging between room temperature and 600°C. Surface roughening starts at 425°C and increases depending on the final annealing temperature and time. The films did not show a reversal of the roughening process upon sample cooling. Also a sub-monolayer film of Co was grown on Al2O 3 (0001) via MBE at room temperature. The film annealed at 400°C revealed the formation of dots with an average diameter of 17.6 nm and a height of 0.3 nm. Dots showed a superparamagnetic behavior with a blocking temperature of 130 K and an enhancement of the atomic magnetic moment over the bulk of approximately 9%

De-wetting of cobalt thin films on sapphire

Cobalt thin films 4 nm thick were deposited via metal electron-beam epitaxy on sapphire (110). The films were annealed above 500°C and scanned in-situ with atomic force microscopy upon annealing. The films underwent a roughening transition above 500°C which is highly time dependent. The film\u27s roughness increased with time with a power law of rho ∼ (t-- t0)alpha, with alpha ranging from 0.16 to 0.21, and de-wetted the sapphire substrate above 590°C. The dynamics of single clusters showed an exponential growth of their height with increasing time at early stages of the annealing process which is consistent with surface instabilities. These instabilities are due to the interplay between surface tension forces (which favor the smoothing out of the surface) and long range Casimir interactions (which favor the thickening and thus roughening of the film). The nature of the Casimir interaction acting within the metallic film was analyzed by calculating the average intercluster separation at early annealing times. The images\u27 autocorrelation function gave an intercluster separation between 150-300 nm, which agrees with expectations resulting from a fermionic Casimir interaction. The fermionic Casimir interaction should be more important for the de-wetting of metallic thin films like cobalt rather than the bosonic Casimir interaction (Van der Waals) that plays an important role in the de-wetting of insulators like polymers. The clusters\u27 evolution for late annealing times showed mainly a growth perpendicular to the surface plane with their areas remaining almost unchanged. The clusters\u27 height increased with a power law h ∼ (t--t 0)beta with beta ∼ 0.25, which in principle is consistent with diffusion in 2 dimensions for a 3 dimensional system (3D/2D), however coalescence and ripening are not observed in the evolution of cobalt thin films. Hence the standard Ostwald ripening theory does not seem to fit well in this system

Aproximación teórica a la evolución de los endosimbiontes bacterianos de los áfidos

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, Departamento de Bioquímica y Biología Molecular, leída el 28/11/2019Los insectos parecen ser particularmente proclives a la convivencia con muy diversas bacterias con quienes establecen relaciones de muy variada índole. En particular, los endosimbiontes primarios se alojan en exclusiva en el interior de células especializadas del insecto denominadas bacteriocitos, se transmiten verticalmente a la descendencia, y establecen una relación de mutua dependencia con el hospedador. Las particularidades de los endosimbiontes primarios han probado ser valiosos modelos en el estudio de las características y consecuencias evolutivas de la transición de un modo de vida libre a uno de dependencia total de un hospedador. El genoma bacteriano sufre diversos cambios tras la transición a un estilo de vida intracelular que desencadenan una masiva inhabilitación y pérdida de genes que desembocan en la constitución de un genoma prácticamente mínimo. A la luz de los datos actuales, adaptación, degeneración y evolución neutral son mecanismos posibles que pueden condicionar esta característica reducción genómica. Entonces, ¿qué fuerzas evolutivas están detrás de las características genómicas observadas en los endosimbiontes de insectos?...Insects seem to be particularly prone to coexistence with very diverse bacteria with whom they establish very varied relationships. In particular, primary endosymbionts are housed exclusively within specialized insect cells called bacteriocytes, are transmitted vertically to offspring, and establish a mutually dependent relationship with the host. The characteristics of the primary endosymbionts have proven to be valuable models in the study of the evolutionary characteristics and consequences of the transition from a free lifestyle to one that is totally dependent on a host. The bacterial genome undergoes various changes after the transition to an intracellular lifestyle that triggers a massive disabling and loss of genes that lead to the constitution of a practically minimal genome. In the light of current data, adaptation, degeneration and neutral evolution are possible mechanisms that may condition this characteristic genomic reduction. So what evolutionary forces are behind the genomic characteristics observed in insect endosymbionts? ...Depto. de Bioquímica y Biología MolecularFac. de Ciencias QuímicasTRUEunpu

Targeting metabolism for resolving Non-Alcoholic Steatohepatitis.

Los capítulos 5.2 y 6 están sujetos a confidencialidad por el autor. 207 p.La presente tesis doctoral trata sobre la modulación del metabolismo para el tratamiento de laesteatohepatitis no alcohólica (EHNA). Esta patología se caracteriza por una acumulación de grasa en elhígado que da lugar a complicaciones derivadas como la muerte celular, la inflamación, hinchamientoo ydesarrollo de fibrosis. Para identificar las dianas terapéuticas presentadas nos hemos centrado enperturbaciones descritas en el transcurso de la EHNA o patologías más severas: el metabolismo delamonio y nitrógeno y la homeostasis de magnesio. En base a ello hemos identificado la glutaminasa 1(GLS1) y la ciclina M4 (CNNM4) como dianas potenciales a la hora de tratar la enfermedad. Se hacaracterizado una sobre-expresión de ambas proteínas en muestras de pacientes diagnosticados de EHNA,así como en modelos animales de ratón de la enfermedad. Se han realizado estudios pre-clínicos en losque se ha inducido la patología por dos dietas distintas y se ha silenciado específicamente la proteínamediante inyección por vena de la cola, inhibiendo así la expresión del enzima en el hígado. En ambosensayos pre-clínicos se ha observado una menor acumulación de lípidos intrahepáticos y una disminucióndel estrés oxidativo derivado. Además, a la hora de elucidar el mecanismo de acción mediante el cual laacumulación de grasa o esteatosis es reducida, se ha identificado que el silenciamiento específico de Gls1y Cnnm4 promueve la secreción de lípidos en forma de partículas de muy baja densidad (VLDL)

Capture and updated information from farm ipad device connection with or without

El presente estudio busca aplicar técnicas para compartir información geográfica en la web y que esta pueda ser editada por un usuario que esta por fuera de la organización desde un IPAD para que luego pueda ser cargada a una base de datos corporativa mediante una conexión a internet. El proyecto se enmarca desde un proceso de identificación predial donde se hace necesario levantar información espacial de los linderos prediales, capturar y/o actualizar información alfanumérica asociada al predio como: Nombre, folio de matrícula inmobiliaria, cedula catastral, vereda, propietario, poseedor etc. Dentro del proceso de levantar información desde un dispositivo móvil por fuera de la organización hay que tener presente que hay zonas del país que no cuenta con conexión a internet en especial las áreas rurales por lo cual se plantea una metodología en la que se utilizan servicio para capturar información geográfica con conexión a internet o sin ella y que esta pueda ser actualizada a la base de datos corporativa después de un tiempo cuando se logre una conexión a internet. El estudio busca mostrar servicios que permiten agilizar los procesos, optimizar recursos y tiempos en proyectos que requieren captura de información en campo.This study seeks to apply techniques for sharing geographic information on the web and that it can be edited by a user that is outside of the organization from an iPad to then can be loaded to a corporate database via an internet connection. The project falls from a farm identification process where it becomes necessary to raise property taxes spatial information boundaries, capture and / or update information associated with the property alphanumeric as: Name, Folio property registration, cadastral cedula, path, owner, holder etc. . In the process of lifting information from a mobile device outside the organization must be remembered that there are areas of the country that does not have internet in particular rural areas for which a methodology is proposed in which service is used to capture geographic information with internet or wrongly and that it can be updated to the corporate database after a time when an internet connection is achieved. The study seeks to show services that allow streamline processes, optimize resources and time in projects requiring data capture in the field

Sličnosno smanjenje linearno–vezanog Korteweg – de Vriesovog sustava

Using the direct method of Clarkson and Kruskal we obtain the similarity reductions of a system of two linearly coupled Korteweg-de Vries equations, which was recently studied by Grimshaw and Malomed in relation to the existence of a new type of gap solitons. Particular solutions of this system, both rational and logarithmic, are also determined.Primjenom Clarkson–Kruskalovog postupka dobiva se sličnosno smanjenje dvaju vezanih Korteweg – de Vriesovih jednadžbi, koje su nedavno proučavali Grimshaw i Malomed. Određena su racionalna i logaritamska partikularna rješenja tog sustava

Sličnosno smanjenje linearno–vezanog Korteweg – de Vriesovog sustava

Using the direct method of Clarkson and Kruskal we obtain the similarity reductions of a system of two linearly coupled Korteweg-de Vries equations, which was recently studied by Grimshaw and Malomed in relation to the existence of a new type of gap solitons. Particular solutions of this system, both rational and logarithmic, are also determined.Primjenom Clarkson–Kruskalovog postupka dobiva se sličnosno smanjenje dvaju vezanih Korteweg – de Vriesovih jednadžbi, koje su nedavno proučavali Grimshaw i Malomed. Određena su racionalna i logaritamska partikularna rješenja tog sustava

Bolívar and the Millennium Development Goals

In spite the notorious advances made by some countries in order to achieve the Millennium Development Goals promoted by the UNDP, the advance within the countries, particularly in their different regions is unknown. This report pretends to show a base line of this project for the Bolívar department, and suggest some policy advices in order to achieve the 2015 goals.Desarrollo humano, human development, Bolívar, Metas del Milenio, ODM, UNDP, Millennium Development Goals

The Jigsaw Puzzle of Economical Research in the Colombian Caribbean: A Balance from the Past Decade (1996-2005) (in Spanish)

In this article it is realized an inventory of the production of academic and scientific articles about economics in Colombian Caribbean Coast in the last 10 years. The document analyses the scientific production in economics realized in the Caribbean Coast and about the Caribbean Coast, in order to establish a map of the regional economic research and realize an approximation to the accumulated production and the general tendencies of the publications. To accomplish this goal, it was used the JEL (Journal of Economic Literature) Classification System as a platform for completing the puzzle by topics. Among other aspects, the study shows that three non-university institutions are responsible for the 67% of the regional academic production about economics. 40% of total considered production was realized by the 10% of the Caribbean Coast researches. 51% of the JEL Classifications have not being approached by region researches. Finally, there are few institutions with a systemic and deep job in a specific topic, which is why there are many possibilities of specialization for institution that have not defined its research lines and want to be pioneers in some economic analysis topic.Regional Economy; Colombia; Caribbean coast; scientific article