Síndrome Postparada Cardiaca: una resivisión bibliográfica sistemática

Desde el desarrollo de la resucitación cardiopulmonar (RCP) y la optimización de los cuatro eslabones de la cadena de supervivencia, el número de pacientes que se recupera de la parada cardiaca (PC), recuperando la circulación espontánea ha aumentado considerablemente. Sin embargo, este mismo aumento de la supervivencia ha generado a su vez, una nueva condición clínica, conocida como Síndrome Post parada cardiaca (SPP), que es responsable de que un importante número de estos pacientes fallezca al de pocos días, generalmente por daño cerebral. Algunos autores han propuesto los cuidados postparada cardiaca como el quinto eslabón de la cadena de superviencia; pero, por ahora es el eslabón más débil y del que menos información disponemos. Objetivos: realizar una lectura crítica de las publicaciones sobre el SPP, sintetizando el material publicado hasta ahora e identificando los aspectos relevantes del mismo. Metodología: revisión bibliográfica sistemática a través de las bases de datos electrónicas: MedLine, PubMed, Crochane, Dialnet, Scopus, Cuiden. Resultados: en general, la calidad de los artículos revisados es baja debido, principalmente, a que la metodología utilizada para la selección y evaluación de los estudios individuales no está descrita en ninguno de ellos. Conclusiones: Aún existe escasa investigación sobre el SPP, y la mayoría de estudios publicados parten de los datos obtenidos en el artículo de consenso ILCOR 2008.

Pololu 3pi robotaren urrutiko kontrola

Denontzat jakina da, azken urteetan robotikaren munduak zelako garrantzia hartu duen teknologiaren munduan. Hurrengo urteetan badirudi hainbat lanetan giza faktorearen beharra txikiagoa izango dela, roboten erabilera handiagotzen baitoa. Robotak lana modu eraginkor batean egiten du eta horrek bere abantailak ditu, bai produktibitate aldetik, bai alde ekonomikotik. Proiektu honetan Pololu 3pi izeneko robot txiki batekin egin da lan. Nahiz eta robot honek bere mugak badituen, aisialdiko eremuetan pieza garrantzitsua izan daitekela uste da. Robot honek eduki dezakeen ohiko erabilera bat da lurrean marrazturik dagoen labirinto batean ibiltzea marrari jarraituz. Proiektu honetan sistema bat garatu nahi izan da, Pololu 3pi robotaren mugimendua urrutiko aginte batez kontrolatzeko, non erabiltzaileak aukeratu ahal duen zein funtzionalitate nahi duen robota kontrolatzeko: Biraketa Zoroa, Mugitu azeleratuz, Wiimote-a mugituz eta Biraketa normal. Hortaz, proiektuan bi zati uztartzen dira, alde batetik Pololu 3pi robota eta bestetik urrutiko aginte bat, kasu honetan Wii bideokontsolaren Wiimote-a. Programa bat sortu da Pololu 3pi-a Wiimote-arekin mugitu eta kontrolatu ahal izateko. Hori posible izan da Atmega328 izeneko mikrokontrolagailuaren bitartez, berari esker programatu ahal izan baita robotaren programa. Aplikazioak bi zati ditu, alde batetik ikusgai zaigun interfaze grafiko bat, non robotaren funtzionalitate ezberdinak ikusten diren PC-aren pantailan. Bestetik robotak berak duen programa, interfazetik eta Wiimote-tik bidaltzen diren aginduei kasu egiten diena.

Detailed properties of high redshift galaxies

Galaxies evolve throughout the history of the universe from the first star-forming sources, through gas-rich asymmetric structures with rapid star formation rates, to the massive symmetrical stellar systems observed at the present day. Determining the physical processes which drive galaxy formation and evolution is one of the most important questions in observational astrophysics. This thesis presents four projects aimed at improving our understanding of galaxy evolution from detailed measurements of star forming galaxies at high redshift.

We use resolved spectroscopy of gravitationally lensed z ≃ 2 - 3 star forming galaxies to measure their kinematic and star formation properties. The combination of lensing with adaptive optics yields physical resolution of ≃ 100 pc, sufficient to resolve giant Hii regions. We find that ~ 70 % of galaxies in our sample display ordered rotation with high local velocity dispersion indicating turbulent thick disks. The rotating galaxies are gravitationally unstable and are expected to fragment into giant clumps. The size and dynamical mass of giant Hii regions are in agreement with predictions for such clumps indicating that gravitational instability drives the rapid star formation. The remainder of our sample is comprised of ongoing major mergers. Merging galaxies display similar star formation rate, morphology, and local velocity dispersion as isolated sources, but their velocity fields are more chaotic with no coherent rotation.

We measure resolved metallicity in four lensed galaxies at z = 2.0 − 2.4 from optical emission line diagnostics. Three rotating galaxies display radial gradients with higher metallicity at smaller radii, while the fourth is undergoing a merger and has an inverted gradient with lower metallicity at the center. Strong gradients in the rotating galaxies indicate that they are growing inside-out with star formation fueled by accretion of metal-poor gas at large radii. By comparing measured gradients with an appropriate comparison sample at z = 0, we demonstrate that metallicity gradients in isolated galaxies must flatten at later times. The amount of size growth inferred by the gradients is in rough agreement with direct measurements of massive galaxies. We develop a chemical evolution model to interpret these data and conclude that metallicity gradients are established by a gradient in the outflow mass loading factor, combined with radial inflow of metal-enriched gas.

We present the first rest-frame optical spectroscopic survey of a large sample of low-luminosity galaxies at high redshift (L < L*, 1.5 < z < 3.5). This population dominates the star formation density of the universe at high redshifts, yet such galaxies are normally too faint to be studied spectroscopically. We take advantage of strong gravitational lensing magnification to compile observations for a sample of 29 galaxies using modest integration times with the Keck and Palomar telescopes. Balmer emission lines confirm that the sample has a median SFR ∼ 10 M_sun yr^−1 and extends to lower SFR than has been probed by other surveys at similar redshift. We derive the metallicity, dust extinction, SFR, ionization parameter, and dynamical mass from the spectroscopic data, providing the first accurate characterization of the star-forming environment in low-luminosity galaxies at high redshift. For the first time, we directly test the proposal that the relation between galaxy stellar mass, star formation rate, and gas phase metallicity does not evolve. We find lower gas phase metallicity in the high redshift galaxies than in local sources with equivalent stellar mass and star formation rate, arguing against a time-invariant relation. While our result is preliminary and may be biased by measurement errors, this represents an important first measurement that will be further constrained by ongoing analysis of the full data set and by future observations.

We present a study of composite rest-frame ultraviolet spectra of Lyman break galaxies at z = 4 and discuss implications for the distribution of neutral outflowing gas in the circumgalactic medium. In general we find similar spectroscopic trends to those found at z = 3 by earlier surveys. In particular, absorption lines which trace neutral gas are weaker in less evolved galaxies with lower stellar masses, smaller radii, lower luminosity, less dust, and stronger Lyα emission. Typical galaxies are thus expected to have stronger Lyα emission and weaker low-ionization absorption at earlier times, and we indeed find somewhat weaker low-ionization absorption at higher redshifts. In conjunction with earlier results, we argue that the reduced low-ionization absorption is likely caused by lower covering fraction and/or velocity range of outflowing neutral gas at earlier epochs. This result has important implications for the hypothesis that early galaxies were responsible for cosmic reionization. We additionally show that fine structure emission lines are sensitive to the spatial extent of neutral gas, and demonstrate that neutral gas is concentrated at smaller galactocentric radii in higher redshift galaxies.

The results of this thesis present a coherent picture of galaxy evolution at high redshifts 2 ≲ z ≲ 4. Roughly 1/3 of massive star forming galaxies at this period are undergoing major mergers, while the rest are growing inside-out with star formation occurring in gravitationally unstable thick disks. Star formation, stellar mass, and metallicity are limited by outflows which create a circumgalactic medium of metal-enriched material. We conclude by describing some remaining open questions and prospects for improving our understanding of galaxy evolution with future observations of gravitationally lensed galaxies.