The shape of the CMB lensing bispectrum

Lensing of the CMB generates a significant bispectrum, which should be detected by the Planck satellite at the 5-sigma level and is potentially a non-negligible source of bias for f_NL estimators of local non-Gaussianity. We extend current understanding of the lensing bispectrum in several directions: (1) we perform a non-perturbative calculation of the lensing bispectrum which is ~10% more accurate than previous, first-order calculations; (2) we demonstrate how to incorporate the signal variance of the lensing bispectrum into estimates of its amplitude, providing a good analytical explanation for previous Monte-Carlo results; and (3) we discover the existence of a significant lensing bispectrum in polarization, due to a previously-unnoticed correlation between the lensing potential and E-polarization as large as 30% at low multipoles. We use this improved understanding of the lensing bispectra to re-evaluate Fisher-matrix predictions, both for Planck and cosmic variance limited data. We confirm that the non-negligible lensing-induced bias for estimation of local non-Gaussianity should be robustly treatable, and will only inflate f_NL error bars by a few percent over predictions where lensing effects are completely ignored (but note that lensing must still be accounted for to obtain unbiased constraints). We also show that the detection significance for the lensing bispectrum itself is ultimately limited to 9 sigma by cosmic variance. The tools that we develop for non-perturbative calculation of the lensing bispectrum are directly relevant to other calculations, and we give an explicit construction of a simple non-perturbative quadratic estimator for the lensing potential and relate its cross-correlation power spectrum to the bispectrum. Our numerical codes are publicly available as part of CAMB and LensPix.Comment: 32 pages, 10 figures; minor changes to match JCAP-accepted version. CMB lensing and primordial local bispectrum codes available as part of CAMB (http://camb.info/

Differentiation of type A foot-and-mouth disease virus subtypes by double-and radial-immunodiffusion analysis.

Para clasificar el virus de la enfermedad de las patas y boca del ganado y reconocer el subtipo, se examinaron cuatro subtipos del virus FMDV (Foot and Mouth Disease Virus) así: A-12, A-24, A-31 y A-32. Si la identidad parcial se obtiene bajo condiciones de campo se indica un nuevo subtipo y deberá ser examinado en mayor detalle. La aplicabilidad de la técnica convencional de inmunodifusión radial para diferenciar subtipos de FMDV fue examinada y probada con antisueros por cada cuatro subtipos de virus para reacciones homólogas y heterogamas. Fueron evidentes las diferencias en apariencia de los anillos formados en el precipitado por sistemas homólogos y heterogamos. Los estimativos de la cantidad de anticuerpos precipitados por estos sistemas, se determinaron asumiendo un valor común (anillo-ración masa), la cual representa la masa inicial de anticuerpo dentro del anillo para la masa de antígenos usados en la fuente. Todos los antisueros contienen gran cantidad de anticuerpos que reaccionan con virus homólogos más que con virus heterogamos. Se hizo un rango tentativo antigénico en el cual los subtipos A-31 y A-32 estuvieron a los extremos de la lista de ordenamiento con subtipos A-24 y A-12 en una posición intermedia así: A-31, A-24, A-12 y A-32. Mientras la doble inmunodifusión permite la diferenciación de estos subtipos, el método SRID (Single Radial Inmunodiffusion Determinations) proporciona estimaciones cuantitativa

CMBR Weak Lensing and HI 21-cm Cross-correlation Angular Power Spectrum

Weak gravitational lensing of the CMBR manifests as a secondary anisotropy in the temperature maps. The effect, quantified through the shear and convergence fields imprint the underlying large scale structure (LSS), geometry and evolution history of the Universe. It is hence perceived to be an important observational probe of cosmology. De-lensing the CMBR temperature maps is also crucial for detecting the gravitational wave generated B-modes. Future observations of redshifted 21-cm radiation from the cosmological neutral hydrogen (HI) distribution hold the potential of probing the LSS over a large redshift range. We have investigated the correlation between post-reionization HI signal and weak lensing convergence field. Assuming that the HI follows the dark matter distribution, the cross-correlation angular power spectrum at a multipole \ell is found to be proportional to the cold dark matter power spectrum evaluated at \ell/r, where r denotes the comoving distance to the redshift where the HI is located. The amplitude of the ross-correlation depends on quantities specific to the HI distribution, growth of perturbations and also the underlying cosmological model. In an ideal ituation, we found that a statistically significant detection of the cross-correlation signal is possible. If detected, the cross-correlation signal hold the possibility of a joint estimation of cosmological parameters and also test various CMBR de-lensing estimators.Comment: 14 pages, 4 figures, publishe

Risk factors for nosocomial pneumonia comparing adult critical-care populations

The purpose of the study was to examine risk factors for nosocomial pneumonia in the surgical and medical/respiratory intensive care unit (ICU) populations. In a public teaching hospital, all cases of nosocomial pneumonia in the surgical and medical/respiratory ICUs (n = 20, respectively) were identified by prospective surveillance during a 5-yr period from 1987-1991. Each group of ICU cases was compared with 40 ICU control patients who did not acquire pneumonia, and analyzed for 25 potential risk factors. Surgical ICU patients were found to have consistently higher rates of nosocomial pneumonia than medical ICU patients (RR = 2.2). The strongest predictor for nosocomial pneumonia in both the surgical and medical/respiratory ICU groups was found to be prolonged mechanical ventilation (> 1 d) resulting in a 12-fold increase in risk over nonventilated patients. APACHE III score was found to be predictive of nosocomial pneumonia in the surgical ICU population, but not in the medical/respiratory ICU population. We conclude that certain groups deserve special attention for infection control intervention. Surgical ICU patients with high APACHE scores and receiving prolonged mechanical ventilation may be at the greatest risk of acquiring nosocomial pneumonia of all hospitalized patients

Quantum Breaking Time Scaling in the Superdiffusive Dynamics

We show that the breaking time of quantum-classical correspondence depends on the type of kinetics and the dominant origin of stickiness. For sticky dynamics of quantum kicked rotor, when the hierarchical set of islands corresponds to the accelerator mode, we demonstrate by simulation that the breaking time scales as $\tau_{\hbar} \sim (1/\hbar)^{1/\mu}$ with the transport exponent $\mu > 1$ that corresponds to superdiffusive dynamics. We discuss also other possibilities for the breaking time scaling and transition to the logarithmic one $\tau_{\hbar} \sim \ln(1/\hbar)$ with respect to $\hbar$

Accelerometry analysis of physical activity and sedentary behavior in older adults: a systematic review and data analysis

Accelerometers objectively monitor physical activity and sedentary patterns and are increasingly used in the research setting. It is important to maintain consistency in data analysis and reporting, therefore, we: (1) systematically identified studies using accelerometry (ActiGraph, Pensacola, FL, USA) to measure moderate-to-vigorous physical activity (MVPA) and sedentary time in older adults, and (2) based on the review findings, we used different cut-points obtained to analyze accelerometry data from a sample of community-dwelling older women. We identified 59 articles with cut-points ranging between 574 and 3,250 counts/min for MVPA and 50 and 500 counts/min for sedentary time. Using these cut-points and data from women (mean age, 70 years), the median MVPA minutes per day ranged between 4 and 80 min while percentage of sedentary time per day ranged between 62 % and 86 %. These data highlight (1) the importance of reporting detailed information on the analysis assumptions and (2) that results can differ greatly depending on analysis parameters.E. Gorman, H. M. Hanson, P. H. Yang, K. M. Khan, T. Liu-Ambrose, M. C. Ash

Localization dynamics in a binary two-dimensional cellular automaton: the Diffusion Rule

We study a two-dimensional cellular automaton (CA), called Diffusion Rule (DR), which exhibits diffusion-like dynamics of propagating patterns. In computational experiments we discover a wide range of mobile and stationary localizations (gliders, oscillators, glider guns, puffer trains, etc), analyze spatio-temporal dynamics of collisions between localizations, and discuss possible applications in unconventional computing.Comment: Accepted to Journal of Cellular Automat

Extended Gari-Krumpelmann model fits to nucleon electromagnetic form factors

Nucleon electromagnetic form factor data (including recent data) is fitted with models that respect the confinement and asymptotic freedom properties of QCD. Gari-Krumpelmann (GK) type models, which include the major vector meson pole contributions and at high momentum transfer conform to the predictions of perturbative QCD, are combined with Hohler-Pietarinen (HP) models, which also include the width of the rho meson and the addition of higher mass vector meson exchanges, but do not evolve into the explicit form of PQCD at high momentum transfer. Different parameterizations of the GK model's hadronic form factors, the effect of including the width of the rho meson and the addition of the next (in mass) isospin 1 vector meson are considered. The quality of fit and the consistency of the parameters select three of the combined HP/GK type models. Projections are made to the higher momentum transfers which are relevant to electron-deuteron experiments. The projections vary little for the preferred models, removing much of the ambiguity in electron-nucleus scattering predictions.Comment: 18pp, 7 figures, using RevTeX with BoxedEPS macros; 1 new figure, minor textual changes; email correspondence to [email protected]

Octet-Baryon Form Factors in the Diquark Model

We present an alternative parameterization of the quark-diquark model of baryons which particularly takes care of the most recent proton electric form-factor data from the E136 experiment at SLAC. In addition to electromagnetic form factors of the nucleon, for which good agreement with data is achieved, we discuss the weak axial vector form factor of the nucleon as well as electromagnetic form factors of $\Lambda$ and $\Sigma$ hyperons. Technical advance in calculating the pertinent analytic expressions within perturbative quantum chromodynamics is gained by formulating the wave function of the quark-diquark system in a covariant way. Finally, we also comment on the influence of Sudakov corrections within the scope of the diquark model.Comment: 16 pages, WU-B 93-07, latex, uuencoded postscript files of 7 figures appended at the end of the latex fil

Effect of recent R_p and R_n measurements on extended Gari-Krumpelmann model fits to nucleon electromagnetic form factors

The Gari-Krumpelmann (GK) models of nucleon electromagnetic form factors, in which the rho, omega, and phi vector meson pole contributions evolve at high momentum transfer to conform to the predictions of perturbative QCD (pQCD), was recently extended to include the width of the rho meson by substituting the result of dispersion relations for the pole and the addition of rho' (1450) isovector vector meson pole. This extended model was shown to produce a good overall fit to all the available nucleon electromagnetic form factor (emff) data. Since then new polarization data shows that the electric to magnetic ratios R_p and R_n obtained are not consistent with the older G_{Ep} and G_{En} data in their range of momentum transfer. The model is further extended to include the omega' (1419) isoscalar vector meson pole. It is found that while this GKex cannot simultaneously fit the new R_p and the old G_{En} data, it can fit the new R_p and R_n well simultaneously. An excellent fit to all the remaining data is obtained when the inconsistent G_{Ep} and G_{En} is omitted. The model predictions are shown up to momentum transfer squared, Q^2, of 8 GeV^2/c^2.Comment: 14 pages, 8 figures, using RevTeX4; email correspondence to [email protected] ; minor typos corrected, figures added, conclusions extende