Sudden death after valve-in-valve procedure due to delayed coronary obstruction. A case report

Background: Valve-in-valve transcatheter aortic valve implantation for degenerated aortic bioprostheses is an effective option for patients at high risk for redo surgery, even if it may be burdened by complications more common in specific settings, such as, coronary artery obstruction. Case presentation: We present the case of a Caucasic 84-year-old woman with degeneration of a previously implanted aortic Mitroflow bioprosthesis. She underwent a valve-in-valve transcatheter aortic valve implantation with a CoreValve® bioprosthesis. End-procedure coronary angiography demonstrated maintained perfusion of both coronary arteries. However, few hours later, she experienced sudden cardiac death. An autopsy showed that Mitroflow prosthesis leaflets were higher than the left main coronary ostium, and no other possible cause for the sudden death. Fatality was thus ascribed to left main coronary ostium obstruction due to apposition of the Mitroflow leaflet pushed upward by the late expansion of CoreValve®. Conclusions: Coronary artery obstruction is a frequently fatal complication which usually presents just after valve implantation, but, as reported in our case, it may also have a delayed presentation. Accurate patient's selection and intraoperative preventive measures can reduce this eventuality

Imaging the first light: experimental challenges and future perspectives in the observation of the Cosmic Microwave Background Anisotropy

Measurements of the cosmic microwave background (CMB) allow high precision observation of the Last Scattering Surface at redshift $z\sim$1100. After the success of the NASA satellite COBE, that in 1992 provided the first detection of the CMB anisotropy, results from many ground-based and balloon-borne experiments have showed a remarkable consistency between different results and provided quantitative estimates of fundamental cosmological properties. During 2003 the team of the NASA WMAP satellite has released the first improved full-sky maps of the CMB since COBE, leading to a deeper insight into the origin and evolution of the Universe. The ESA satellite Planck, scheduled for launch in 2007, is designed to provide the ultimate measurement of the CMB temperature anisotropy over the full sky, with an accuracy that will be limited only by astrophysical foregrounds, and robust detection of polarisation anisotropy. In this paper we review the experimental challenges in high precision CMB experiments and discuss the future perspectives opened by second and third generation space missions like WMAP and Planck.Comment: To be published in "Recent Research Developments in Astronomy & Astrophysics Astrophysiscs" - Vol I

Determining Foreground Contamination in CMB Observations: Diffuse Galactic Emission in the MAXIMA-I Field

Observations of the CMB can be contaminated by diffuse foreground emission from sources such as Galactic dust and synchrotron radiation. In these cases, the morphology of the contaminating source is known from observations at different frequencies, but not its amplitude at the frequency of interest for the CMB. We develop a technique for accounting for the effects of such emission in this case, and for simultaneously estimating the foreground amplitude in the CMB observations. We apply the technique to CMB data from the MAXIMA-1 experiment, using maps of Galactic dust emission from combinations of IRAS and DIRBE observations, as well as compilations of Galactic synchrotron emission observations. The spectrum of the dust emission over the 150--450 GHz observed by MAXIMA is consistent with preferred models but the effect on CMB power spectrum observations is negligible.Comment: 19 pages, 8 figures, accepted for publication in the Astrophysical Journal. Monor changes to match the published versio

Estimate of the Cosmological Bispectrum from the MAXIMA-1 Cosmic Microwave Background Map

We use the measurement of the cosmic microwave background taken during the MAXIMA-1 flight to estimate the bispectrum of cosmological perturbations. We propose an estimator for the bispectrum that is appropriate in the flat sky approximation, apply it to the MAXIMA-1 data and evaluate errors using bootstrap methods. We compare the estimated value with what would be expected if the sky signal were Gaussian and find that it is indeed consistent, with a $\chi^2$ per degree of freedom of approximately unity. This measurement places constraints on models of inflation.Comment: 5 pages, 2 figures. New version to match paper accepted for publication in Phys. Rev. Lett. Non-diagonal terms included leading to new limits on f_N

Rotación de Maíz y Soja en siembra directa con riego en el Noroeste de la Provincia de Corrientes

El trabajo realizado en el Campo Didáctico Experimental de la Facultad de Ciencias Agrarias de la UNNE, tuvo por finalidad determinar la factibilidad agronómica de un sistema productivo de doble cultivo con secuencia primavero-estival, utilizando riego suplementario, en un suelo Udipsament árgico, perteneciente a la serie Ensenada Grande. Se analizaron los resultados de dos modelos alternativos de rotación: maíz-soja y soja-maíz en siembra directa durante tres campañas agrícolas 1995/96, 96/97 y 97 /98. El ensayo se realizó en un diseño de bloques completos al azar con cuatro repeticiones en parcelas de 3.5 por 7 metros. Los materiales utilizados fueron seleccionados de acuerdo con la fecha de siembra, la fertilización fue ajustada según expectativas de altos rendimientos y los riegos complementados fueron realizados según el balance hídrico de cada campaña. Se evaluó el rendimiento final y la producción de rastrojo de cada cultivo. Estadísticamente se compararon los dos sistemas de rotación y los rendimientos de cada uno de los cultivos según fecha de siembra, estableciéndose resultados favorables a la rotación maíz-soja

Rendimiento de cultivares de linos oleaginosos en dos series de suelos del noroeste de Corrientes

Fue analizado el comportamiento varietal de linos oleaginosos, a través de su rendimiento en semillas, en dos suelos de la Provincia de Corrientes, mediante la realización de cuatro ensayos comparativos durante tres campañas, encontrándose diferencias en los rendimientos medios según las características de los suelos comparados. En el suelo identificado como perteneciente a la serie Paso Patria, de textura superficial franco-arenosa, en el primer año (1993) se obtuvo una media de 1207 Kg.ha-1 con el mejor rendimiento para Reconquista INTA con 1231 Kg.ha-1; y en el segundo año (1994), el promedio fue de 1158 Kg.ha-1, destacándose Malabrigo INTA con 1198Kg.ha-1. En el suelo perteneciente a la serie Ensenada Grande, textura arenosa, en el primer año (1994) se obtuvo una media de 914 Kg.ha-1 con un máximo de 1028.2 Kg.ha-1 para Tape Paraná INTA; y en el segundo año (1995), la media fue de 968.9 Kg.ha-1, con un rendimiento máximo de 1087.7 Kg.ha-1 paraMalabrigo INTA

Rendimiento y contenido proteico de trigo (Triticum aestivum L.) en Corrientes

Si bien la producción de trigo en la Provincia de Corrientes, nunca fue considerada una alternativa, el desarrollo del cultivo en zonas limítrofes y los precios internacionales alcanzados motivan la realización del presente estudio. El objetivo fue evaluar el rendimiento y el contenido proteico del grano en 1 O variedades de trigo nacionales e introducidas de países limítrofes en 3 fechas de siembra. El ensayo se realizó en el noroeste de la provincia de Corrientes en fechas escalonadas entre el 23 de mayo y el 3 de Julio, utilizando 2 variedades nacionales (Klein Chamaco y Pro-INTA Oasis); una de la República del Brasil (Br-23) y 7 de procedencia de la República del Paraguay (ltapuá 35. ltapuá 40, IAN 7, IAN 8, JAN 9, Cordillera 3 y Cordillera 4). La evaluación de los rendimientos finales y el contenido en proteínas de los granos permitieron establecer correlaciones con las fechas de siembra, ambas variables disminuyeron a medida que se atrasaban las fechas de siembra. Todos los valores de proteínas registrados superaron la base de comercialización

MAXIMA: an experiment to measure temperature anisotropy in the cosmic microwave background

We describe the MAXIMA experiment, a balloon-borne measurement designed to map temperature anisotropy in the Cosmic Microwave Background (CMB) over a wide range of angular scales (multipole range 80 < l < 800). The experiment consists of a 1.3 m diameter off-axis Gregorian telescope and a receiver with a 16 element array of bolometers cooled to 100 mK. The frequency bands are centered at 150, 240, and 410 GHz. The 10' FWHM beam sizes are well matched to the scale of acoustic peaks expected in the angular power spectrum of the CMB. The first flight of the experiment in its full configuration was launched in August 1998. A 122 sq-deg map of the sky was made near the Draco constellation during the 7 hour flight in a region of extremely low galactic dust contamination. This map covers 0.3% of the sky and has 3200 independent beamsize pixels. We describe the MAXIMA instrument and its performance during the recent flight.Comment: To appear in proceedings of `3K Cosmology', ed. F Melchiorri, Conference held Oct 5-10 1998, Rome, 13 pages LaTeX (using aipproc2.sty & aipproc2.cls), Postscript with higher resolution graphics available at http://cfpa.berkeley.edu/group/cmb/gen.htm

Sterile neutrinos: direct mixing effects versus induced mass matrix of active neutrinos

Mixing of active neutrinos with sterile ones generate ``induced'' contributions to the mass matrix of active neutrinos $\sim m_S \sin^2\theta_{aS}$, where $m_S$ is the Majorana mass of the sterile neutrino and $\theta_{aS}$ is the active-sterile mixing angle. We study possible effects of the induced matrix which can modify substantially the implications of neutrino oscillation results. We have identified the regions of $m_S$ and $\sin^2\theta_{aS}$ where the induced matrix (i) provides the dominant structures, (ii) gives the sub-dominant effects and (iii) where its effects can be neglected. The induced matrix can be responsible for peculiar properties of the lepton mixing and neutrino mass spectrum, in particular, it can generate the tri-bimaximal mixing. We update and discuss bounds on the induced masses from laboratory measurements, astrophysics and cosmology. We find that substantial impact of the induced matrix is possible if $m_S \sim 0.1-1$ eV and $\sin^2\theta_{aS} \sim 10^{-3} - 10^{-2}$ or $m_S \geq 200$ MeV and $\sin^2\theta_{aS} \leq 10^{-9}$. The bounds can be relaxed in cosmological scenarios with low reheating temperature, if sterile neutrinos decay sufficiently fast, or their masses change with time.Comment: Figures updated, version to be published in Phys. Rev.

Natural Quintessence with Gauge Coupling Unification

We show that a positive accelerating universe can be obtained simply by the dynamics of a non-abelian gauge group. It is the condensates of the chiral fields that obtain a negative power potential, below the condensation scale, and allow for a quintessence interpretation of these fields. The only free parameters in this model are $N_c$ and $N_f$ and the number of dynamically gauge singlet bilinear fields $\phi$ generated below the condensation scale. We show that it is possible to have unification of all coupling constants, including the standard and non standard model couplings, while having an acceptable phenomenology of $\phi$ as the cosmological constant. This is done without any fine tuning of the initial conditions. The problem of coincidence (why the universe has only recently started an accelerating period) is not solved but it is put at the same level as what the particle content of the standard model is.Comment: minor changes(discussion on field normalization included), reference added, accepted in Phy.Rev.Lett., 5 pages,LateX,2 Figure