Illumination and Temperature on Rough Terrain: Fast Methods for Solving the Radiosity Equation

No abstract availabl

On the GRAIL-LLR Low-Degree Gravity Field Inconsistencies

No abstract availabl

Application behavior and performance on asymmetrical links

Projecte final de carrera ralitzat en col.laboració amb Lund University. Faculty of EngineeringNowadays most of the access networks have asymmetrical bit rates; these networks (especially mobile networks) have high delays, packet losses and most often non neglectable jitter. In this degree project, we have studied the behavior of several different types of access networks with asymmetrical conditions. We have worked with the Kaunet deterministic network emulator to achieve practical results of these access networks. With the network emulator we have created different types of asymmetrical traffic data. The applications we have studied are Skype (voice/data in real time), web browsing (HTTP), TVUPlayer (P2P-TV), Bit Torrent (P2P sharing data) and data transmission in FTP. We analyzed how the protocols and the applications behaved in a theoretical way and then we tested them in a practical way with Kaunet. We studied how asymmetries affect delay times, packet losses and jitter introduced in the network and for each application we gave boundaries for a good performance for the mentioned parameters. Furthermore we analyzed bottlenecks and tried to minimize them. Finally, we compared the data from the different types of generated traffic and made some conclusions about the behavior of these applications in an asymmetrical environment

Deregulation of Choline Kinase in Pancreatic Cancer and its inhibition as a potential therapeutic strategy.

El presente trabajo busca profundizar en el papel del metabolismo de la fosfatidilcolina y una de las enzimas principales de la vía de su síntesis, la Colina Quinasas, en la génesis y desarrollo del adenocarcinoma de páncreas. El adenocarcinoma de páncreas constituye uno de los mayores retos de la Oncología en la actualidad, pues si bien se encuentra en una modesta décima posición en cuanto a su prevalencia, constituye la cuarta causa de muerte por cáncer en la sociedades occidentales debido a su diagnóstico en fases avanzadas y la resistencia del tumor a los tratamiento existentes. Una mejor comprensión de su biología molecular debería permitir el desarrollo de nuevos fármacos. La desregulación del metabolismo es uno de los aspectos centrales en el desarrollo de muchos tumores. La presente tesis doctoral ahonda en el papel de la Colina Quinasa, una quinasa perteneciente a la vía de Kennedy, responsable de la síntesis de la fosfatidilcolina, el principal fosfolípido de las membranas de las células eucariotas. Los experimentos realizados en líneas celulares de cáncer de páncreas y en muestras de tumores humanos permiten afirmar que la Colina Quinasa se encuentra sobreexpresada en el cáncer de páncreas. La atenuación de su expresión mediante técnicas de silenciamiento genético muestra que se trata de una enzima importante para la proliferación celular. Colina Quinasa constituye una nueva diana terapéutica en el cáncer de páncreas. Su inhibición farmacológica con un inhibidor específico, MN58b, induce apoptosis en células de cáncer de páncreas en función de sus niveles enzimáticos lo que sugiere que podría ser una factor predictivo de respuesta al MN58b. Asimismo, MN58b mostró efecto citotóxico contra las Pancreatic Stellate Cells (PSC), uno de los subtipos celulares principales del estroma de PDAC y responsables, en gran medida, de su quimioresistencia. La combinación de inhibidores de Colina Quinasa con otros quimioterápicos podría ser otra alternativa terapéutica ya que MN58b muestra sinergia con Gemcitabina, Oxaliplatino y 5-Fluouracilo. La adquisición de resistencia a la quimioterapia constituye uno de los mayores problemas en Oncología. Para profundizar en los mecanismos llevan a ella, generé una línea celular de PDAC resistente a MN58b. La células resistentes mostraban, respecto a las basales, un descenso en la captación de colina, una menor tasa de proliferación y una reducción en sus capacidades migratorias. Describo la sobreexpresión de ABCB-1 y ABCB-4 como el mecanismo responsable de la adquisición de resistencia. Estas dos proteínas pertenecen a la familia de proteína de resistencia de múltiples fármacos que expulsan los fármacos del interior de las células. De acuerdo con los previo, el bloqueo de dichas proteínas de transmembrana restituyó la sensibilidad originaria al MN58b

Estimating the Lunar Core Equatorial Ellipticity using Lunar Laser Ranging

No abstract availabl

Precise orbit determination of the Mars Odyssey spacecraft and geodetic inversion for the Martian gravity field

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2004.Includes bibliographical references (leaves 73-75).Remote sensing techniques are widely used in planetary science for acquiring precise, global inforniation about an object. One of these techniques consists of the study of the radio signals emitted by a spacecraft, from which it is possible to derive the forces acted upon it. For this project, we used the radio science data from the Mars-orbiting spacecraft "IMars Odyssey". Launched in April 2001, more than two years of daily radio tracking of this satellite are now available, allowing for Precision Orbit Determination. Using the program Geodyn, the position of the spacecraft with respect to the centre of mass of Mars is typically determined down to a few meters, while the velocity precision is better than 1 mm/s. Once a large number of orbits have been calculated, it is possible to use the residuals (misfits of the data to the modeled trajectory) to solve for some of the model parameters. Here, we determine the coefficients of the spherical harmonic expansion of the gravity field, as well as the drag coefficient of the satellite (a proxy for atmospheric density). To obtain such results, many high-precision data sets and models are combined: electromagnetic wave propagation, with tropospheric and ionospheric corrections; tracking station positions, including tidal and tracking station corrections; solar and thermal radiation; ephemerides of all the major bodies in the Solar System, plus the Martian moons. The inputs of the orbit determination program are the radio signals (Doppler and range), the angular momentum desaturations t.inings, the attitude (of the main bus of course, but also of the high-gain antenna and the solar panels), and a model of the spacecraft. Some results of this radio science experiment are pre-sented here, in the form(cont.) of gravity field spherical harmonic expansions sensed by the spacecraft.by Erwan Matías Alexandre Mazarico.S.M

Mercury's Internal Structure

We describe the current state of knowledge about Mercury's interior structure. We review the available observational constraints, including mass, size, density, gravity field, spin state, composition, and tidal response. These data enable the construction of models that represent the distribution of mass inside Mercury. In particular, we infer radial profiles of the pressure, density, and gravity in the core, mantle, and crust. We also examine Mercury's rotational dynamics and the influence of an inner core on the spin state and the determination of the moment of inertia. Finally, we discuss the wide-ranging implications of Mercury's internal structure on its thermal evolution, surface geology, capture in a unique spin-orbit resonance, and magnetic field generation.Comment: 36 pages, 11 figures, in press, to appear in "Mercury - The View after MESSENGER", S. C. Solomon, B. J. Anderson, L. R. Nittler (editors), Cambridge University Pres

Home automation sensor network with Web 2.0 interface

The project departs from a final project done before, dedicated to the configuration of a wireless sensor network to measure temperature and send the data to the gateway using and designed message forwarding protocol. The collected data was shown in a webpage. The aim of this project is the development of a network of sensor nodes using a sensor designed by the research group of wireless networks of UPC. The interaction between the user and the sensor network will be through the gateway and through the Google Calendar and Twitter interfaces. An activator has been designed to connect any device to it. The user can activate or deactivate through Google Calendar any device connected to it. The nodes also measure temperature and show the data through Twitter. A communication protocol was designed and optimized to provide more robustness and new features to the network. Also a gateway interface was designed to allow the user control the network through it. This application provides functionality such as add, modify or delete events from Google Calendar and allows real time user interaction via Twitter

Implementació d'una solució domòtica basada en sensors (II)

Aquest projecte parteix d'un treball final de carrera anterior, dedicat a la configuració d'un node sensor i un altre controlador mitjançant l'acoblament d'uns mòduls d'infraroig. Un cop establerta la configuració inicial, aconseguia transmetre una ordre al sensor. L'objectiu del present TFC és la implementació d'una xarxa de nodes sensors, utilitzant un sensor dissenyat pel grup de recerca de xarxes sense fils de la UPC i el disseny i realització dels mòduls utilitzats en el projecte anterior, l'emissor i receptor d'infraroig, així com altres mòduls necessaris per a la interactuació amb l'usuari com seria un teclat. Per tal d'establir la comunicació entre els diferents nodes encara que no tinguin comunicació directa entre ells, s'ha creat un protocol de reenviament de missatges. El disseny d'aquesta xarxa s'ha utilitzat per tal d'obtenir els valors de temperatura dels nodes sensors. A fi de mostrar de forma visual l'evolució d'aquesta variable, s'ha creat una interfície web on es pugen les dades via FTP, i on es pot visualitzar aquesta gràfica a través de qualsevol navegador web

Long-term variability of CO2 and O in the Mars upper atmosphere from MRO radio science data

We estimate the annual variability of CO2 and O partial density using approximately 6years of Mars Reconnaissance Orbiter (MRO) radio science data from August 2006 to January 2012, which cover three full Martian years (from the northern hemisphere summer of 28 to the northern hemisphere summer of 31). These two elements are the dominant species at the MRO periapsis altitude, constituting about 70-80% of the total density. We report the recovered annual cycle of CO2 and the annual and seasonal cycle of O in the upper atmosphere. Although no other observations are available at those altitudes, our results are in good agreement with the density measurements of the Mars Express Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars, which uses stellar occultations between 60 and 130km to determine the CO2 variability, and with the Mars Global Reference Atmospheric Model 2010 for the O annual and seasonal variabilities. Furthermore, the updated model provides more reasonable MRO drag coefficients (CD), which are estimated to absorb mismodeling in the atmospheric density prediction. The higher content of dust in the atmosphere due to dust storms increases the density, so the CDs should compensate for this effect. The correlation between the drag coefficient and the dust optical depth, measured by the Mars Odyssey Thermal Emission Imaging System (THEMIS) instrument, increases from 0.4 to 0.8 with the a priori and adjusted models, respectively. The trend of CDs not only confirms a substantial improvement in the prediction of the atmospheric density with the updated model but also provides useful information for local dust storms, near MRO periapsis, that cannot be measured by the opacity level since THEMIS does not always sample the southern hemisphere evenly