Epidemiological studies on the poliomyelitis in Spain before the vaccination

The eradication of polio in Spain is one of the most important health milestones of the twentieth century, not only for public health but also for the effect it had on scientific knowledge in our country, in the medical field. Knowledge of international literature by our epidemiologists and virologists, was important, as reflected in the studies of outbreaks, virological studies and clinical studies. For public health represented, throughout the twentieth century, an effort geared to make decisions based on scientific knowledge. For epidemiology represented the application of new ways of working and, therefore, its modernization. La erradicación de la poliomielitis en España es uno de los hitos sanitarios más importantes del siglo XX, no solo para la salud pública sino también por el efecto que su conocimiento científico tuvo en en el ámbito médico de nuestro país. El conocimiento de la literatura internacional por nuestros epidemiólogos y virólogos fue importante, como reflejan los estudios de los brotes epidémicos, los estudios virológicos y, lógicamente, los estudios clínicos. Para la salud pública representó, a lo largo de todo el siglo XX, un esfuerzo orientado a tomar decisiones basadas en el conocimiento científico. Para la epidemiología representó la aplicación de nuevas formas de trabajo y, por tanto, su modernización.S

Diffeomorphisms, Noether Charges and Canonical Formalism in 2D Dilaton Gravity

We carry out a parallel study of the covariant phase space and the conservation laws of local symmetries in two-dimensional dilaton gravity. Our analysis is based on the fact that the Lagrangian can be brought to a form that vanishes on-shell giving rise to a well-defined covariant potential for the symplectic current. We explicitly compute the symplectic structure and its potential and show that the requirement to be finite and independent of the Cauchy surface restricts the asymptotic symmetries.Comment: 14 pages, latex with psfig macro, one figur

An Alternative Approach to Obtain a New Gain in Step-Size of LMS Filters Dealing with Periodic Signals

Partial updates (PU) of adaptive filters have been successfully applied in different contexts to lower the computational costs of many control systems. In a PU adaptive algorithm, only a fraction of the coefficients is updated per iteration. Particularly, this idea has been proved as a valid strategy in the active control of periodic noise consisting of a sum of harmonics. The convergence analysis carried out here is based on the periodic nature of the input signal, which makes it possible to formulate the adaptive process with a matrix-based approach, the periodic least-mean-square (P-LMS) algorithm In this paper, we obtain the upper bound that limits the step-size parameter of the sequential PU P-LMS algorithm and compare it to the bound of the full-update P-LMS algorithm. Thus, the limiting value for the step-size parameter is expressed in terms of the step-size gain of the PU algorithm. This gain in step-size is the quotient between the upper bounds ensuring convergence in the following two scenarios: first, when PU are carried out and, second, when every coefficient is updated during every cycle. This step-size gain gives the factor by which the step-size can be multiplied so as to compensate for the convergence speed reduction of the sequential PU algorithm, which is an inherently slower strategy. Results are compared with previous results based on the standard sequential PU LMS formulation. Frequency-dependent notches in the step-size gain are not present with the matrix-based formulation of the P-LMS. Simulated results confirm the expected behavior

High frequency mechanical excitation of a silicon nanostring with piezoelectric aluminum nitride layers

A strong trend for quantum based technologies and applications follows the avenue of combining different platforms to exploit their complementary technological and functional advantages. Micro and nano-mechanical devices are particularly suitable for hybrid integration due to the easiness of fabrication at multi-scales and their pervasive coupling with electrons and photons. Here, we report on a nanomechanical technological platform where a silicon chip is combined with an aluminum nitride layer. Exploiting the AlN piezoelectricity, Surface Acoustic Waves are injected in the Si layer where the material has been localy patterned and etched to form a suspended nanostring. Characterizing the nanostring vertical displacement induced by the SAW, we found an external excitation peak efficiency in excess of 500 pm/V at 1 GHz mechanical frequency. Exploiting the long term expertise in silicon photonic and electronic devices as well as the SAW robustness and versatility, our technological platform represents a strong candidate for hybrid quantum systems

The use of the capture- recapture method in evaluating the epidemiological meningococcal disease monitoring system in Tenerife, Spain (1999-2000)

BACKGROUND: Meningococcal Disease is mainly monitored passively on the Canary Islands, the regular Compulsory Disease Notification channels being used. The objective of this study includes describing the qualitative and quantitative aspects of this system and evaluating the exhaustiveness, by means of the capture-recapture system, of three information sources. METHODS: This study covers the 1999-2001 period in Tenerife. The information was gathered from three sources: the Compulsory Disease Notification System, the Microbiology Laboratories and the hospital Minimum Basic Data Set. The Evaluation Protocols of the Monitoring System of the Atlanta Centers of Disease Control and Prevention were used. A log-linear model was used for estimating the number of cases. The calculations of the exhaustiveness and the 95% confidence intervals were done in the SPSS10 statistics package. RESULTS: The system was found to have an 84.9% sensitivity, and an 80.4% positive predictive value. The delay in notification (timeliness) fell within the 0.5-13-day range, averaging 3 days. The system was found to have a 76.6% overall acceptability. The exhaustiveness value was 98.1%. CONCLUSIONS: This disease is being monitored well, with a degree of sensitivity which would be revealing of a good notification level, also confirmed by its exhaustiveness. Although the positive predictive value is high, this could be indicative of the expeditious starting of antibiotic treatment which would hinder microbiological confirmation. The system is timely, affording the possibility of measures being taken for fast intervention. Fundamento: La vigilancia de la Enfermedad Meningocócica en Canarias es fundamentalmente pasiva, sirviéndose del circuito habitual de las Enfermedades de Declaración Obligatoria. El objetivo de este trabajo incluye describir los atributos cualitativos y cuantitativos del sistema y evaluar la exhaustividad mediante el sistema de captura-recaptura de tres fuentes de información. Métodos: El estudio abarca los años 1999-2001 en Tenerife. La información se obtuvo de tres fuentes: el Sistema de las Enfermedades de Declaración Obligatoria, los Laboratorios de Microbiología y el Conjunto Mínimo Básico de Datos hospitalario. Se aplicaron los Protocolos de Evaluación de un Sistema de Vigilancia de los Centers of Disease Control and Prevention, de Atlanta. Para la estimación del número de casos se usó un modelo log-linear. Los cálculos de la exhaustividad y los intervalos de confianza al 95% se realizaron en el paquete estadístico SPSS10. Resultados: La sensibilidad del sistema resultó ser del 84,9% y el valor predictivo positivo del 80,4%. El retraso en la notificación (oportunidad) osciló entre los 0,5 y 13 días, con una mediana de 3 días. La aceptabilidad global del sistema ha sido del 76,64%. El valor de la exhaustividad fue del 98,1%. Conclusiones: La vigilancia de esta enfermedad es buena, con una sensibilidad que hablaría de un buen nivel de declaración, reafirmada por la exhaustividad. Aunque el valor predictivo positivo es alto, podría apuntar hacia la rápida instauración de tratamiento antibiótico que impediría la confirmación microbiológica. El sistema es oportuno, permitiendo la rápida adopción de medidas de intervención

Unusual Stokes V profiles during flaring activity of a delta sunspot

We analyze a set of full Stokes profile observations of the flaring active region NOAA 10808 recorded with the Vector-Spectromagnetograph (VSM) of the SOLIS facility. We aim to quantify transient and permanent changes in the magnetic field and velocity field. The results are put in context with MDI magnetograms and reconstructed RHESSI X-ray images. We find signs of restructuring of the photospheric magnetic field during the flare close to the polarity inversion line (PIL) at the flaring site. At two locations in the umbra we encounter strong fields (approx. 3 kG), as inferred from the Stokes I profiles which, however, exhibit a low polarization signal. During the flare we observe in addition asymmetric Stokes V profiles at one of these sites. The asymmetric Stokes V profiles appear co-spatial and co-temporal with a strong apparent polarity reversal observed in MDI-magnetograms and a chromospheric hard X-ray source. The two-component atmosphere fits of the asymmetric Stokes profiles result in line-of-sight velocity differences in the range of approx. 12km/s to 14 km/s between the two components in the photosphere. Another possibility is that local atmospheric heating is causing the observed asymmetric Stokes V profile shape. In either case our analysis shows that a very localized patch of approx. 5 arcsec in the photospheric umbra, co-spatial with a flare footpoint, exhibits a sub-resolution fine structure.Comment: 13 pages, 10 figures, 1 tabl

Shallow Dark Matter Cusps in Galaxy Clusters

We study the evolution of the stellar and dark matter components in a galaxy cluster of $10^{15} \, \rm{M_{\odot}}$ from $z=3$ to the present epoch using the high-resolution collisionless simulations of Ruszkowski & Springel (2009). At $z=3$ the dominant progenitor halos were populated with spherical model galaxies with and without accounting for adiabatic contraction. We apply a weighting scheme which allows us to change the relative amount of dark and stellar material assigned to each simulation particle in order to produce luminous properties which agree better with abundance matching arguments and observed bulge sizes at $z=3$. This permits the study of the effect of initial compactness on the evolution of the mass-size relation. We find that for more compact initial stellar distributions the size of the final Brightest Cluster Galaxy grows with mass according to $r\propto M^{2}$, whereas for more extended initial distributions, $r\propto M$. Our results show that collisionless mergers in a cosmological context can reduce the strength of inner dark matter cusps with changes in logarithmic slope of 0.3 to 0.5 at fixed radius. Shallow cusps such as those found recently in several strong lensing clusters thus do not necessarily conflict with CDM, but may rather reflect on the initial structure of the progenitor galaxies, which was shaped at high redshift by their formation process.Comment: 8 pages, 4 figures, submitted to MNRA

Halo properties and secular evolution in barred galaxies

The halo plays a crucial role in the evolution of barred galaxies. Its near-resonant material absorbs angular momentum emitted from some of the disc particles and helps the bar become stronger. As a result, a bar (oval) forms in the inner parts of the halo of strongly barred disc galaxies. It is thinner in the inner parts (but still considerably fatter than the disc bar) and tends to spherical at larger radii. Its length increases with time, while always staying shorter than the disc bar. It is roughly aligned with the disc bar, which it trails only slightly, and it turns with roughly the same pattern speed. The bi-symmetric component of the halo density continues well outside the halo bar, where it clearly trails behind the disc bar. The length and strength of the disc and halo bars correlate; the former being always much stronger than the latter. If the halo is composed of weakly interacting massive particles, then the formation of the halo bar, by redistributing the matter in the halo and changing its shape, could influence the expected annihilation signal. This is indeed found to be the case if the halo has a core, but not if it has a steep cusp. The formation and evolution of the bar strongly affect the halo orbits. A fraction of them becomes near-resonant, similar to the disc near-resonant orbits at the same resonance, while another fraction becomes chaotic. Finally, a massive and responsive halo makes it harder for a central mass concentration to destroy the disc bar.Comment: 6 pages, 3 figures, to appear in "Island Universes - Structure and Evolution of Disk Galaxies" ed. R. S. de Jon

Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C

Ion implantation of Mn ions into hole-doped GaP has been used to induce ferromagnetic behavior above room temperature for optimized Mn concentrations near 3 at.%. The magnetism is suppressed when the Mn dose is increased or decreased away from the 3 at.% value, or when n-type GaP substrates are used. At low temperatures the saturated moment is on the order of one Bohr magneton, and the spin wave stiffness inferred from the Bloch-law T^3/2 dependence of the magnetization provides an estimate Tc = 385K of the Curie temperature that exceeds the experimental value, Tc = 270K. The presence of ferromagnetic clusters and hysteresis to temperatures of at least 330K is attributed to disorder and proximity to a metal-insulating transition.Comment: 4 pages, 4 figures (RevTex4

The ISLAndS project II: The Lifetime Star Formation Histories of Six Andromeda dSphs

The Initial Star formation and Lifetimes of Andromeda Satellites (ISLAndS) project uses Hubble Space Telescope imaging to study a representative sample of six Andromeda dSph satellite companion galaxies. The main goal of the program is to determine whether the star formation histories (SFHs) of the Andromeda dSph satellites demonstrate significant statistical differences from those of the Milky Way, which may be attributable to the different properties of their local environments. Our observations reach the oldest main sequence turn-offs, allowing a time resolution at the oldest ages of ~ 1 Gyr, which is comparable to the best achievable resolution in the MW satellites. We find that the six dSphs present a variety of SFHs that are not strictly correlated with luminosity or present distance from M31. Specifically, we find a significant range in quenching times (lookback times from 9 to 6 Gyr), but with all quenching times more than ~ 6 Gyr ago. In agreement with observations of Milky Way companions of similar mass, there is no evidence of complete quenching of star formation by the cosmic UV background responsible for reionization, but the possibility of a degree of quenching at reionization cannot be ruled out. We do not find significant differences between the SFHs of the three members of the vast, thin plane of satellites and the three off-plane dSphs. The primary difference between the SFHs of the ISLAndS dSphs and Milky Way dSph companions of similar luminosities and host distances is the absence of very late quenching (< 5 Gyr ago) dSphs in the ISLAndS sample. Thus, models that can reproduce satellite populations with and without late quenching satellites will be of extreme interest.Comment: 24 pages, 11 figures, 3 tables, submitted to the Ap