Probing non-Gaussianities in the CMB on an incomplete sky using surrogates

We demonstrate the feasibility to generate surrogates by Fourier-based methods for an incomplete data set. This is performed for the case of a CMB analysis, where astrophysical foreground emission, mainly present in the Galactic plane, is a major challenge. The shuffling of the Fourier phases for generating surrogates is now enabled by transforming the spherical harmonics into a new set of basis functions that are orthonormal on the cut sky. The results show that non-Gaussianities and hemispherical asymmetries in the CMB as identified in several former investigations, can still be detected even when the complete Galactic plane (|b| < 30{\deg}) is removed. We conclude that the Galactic plane cannot be the dominant source for these anomalies. The results point towards a violation of statistical isotropy.Comment: 9 pages, 13 figures, accepted by Physical Review

Reconstructing Projected Matter Density from Cosmic Microwave Background

Gravitational lensing distorts the cosmic microwave background (CMB) anisotropies and imprints a characteristic pattern onto it. The distortions depend on the projected matter density between today and redshift $z \sim 1100$. In this paper we develop a method for a direct reconstruction of the projected matter density from the CMB anisotropies. This reconstruction is obtained by averaging over quadratic combinations of the derivatives of CMB field. We test the method using simulations and show that it can successfully recover projected density profile of a cluster of galaxies if there are measurable anisotropies on scales smaller than the characteristic cluster size. In the absence of sufficient small scale power the reconstructed maps have low signal to noise on individual structures, but can give a positive detection of the power spectrum or when cross correlated with other maps of large scale structure. We develop an analytic method to reconstruct the power spectrum including the effects of noise and beam smoothing. Tests with Monte Carlo simulations show that we can recover the input power spectrum both on large and small scales, provided that we use maps with sufficiently low noise and high angular resolution.Comment: 21 pages, 9 figures, submitted to PR

Topology of the universe from COBE-DMR; a wavelet approach

In this paper we pursue a new technique to search for evidence of a finite Universe, making use of a spherical mexican-hat wavelet decomposition of the microwave background fluctuations. Using the information provided by the wavelet coefficients at several scales we test whether compact orientable flat topologies are consistent with the COBE-DMR data. We consider topological sizes ranging from half to twice the horizon size. A scale-scale correlation test indicates that non-trivial topologies with appropriate topological sizes are as consistent with the COBE-DMR data as an infinite universe. Among the finite models the data seems to prefer a Universe which is about the size of the horizon for all but the hypertorus and the triple-twist torus. For the latter the wavelet technique does not seem a good discriminator of scales for the range of topological sizes considered here, while a hypertorus has a preferred size which is 80% of the horizon. This analysis allows us to find a best fit topological size for each model, although cosmic variance might limit our ability to distinguish some of the topologies.Comment: 10 pages, 13 figures (12 coloured), submitted to MNRAS. Figures 1,2 and 3 are not included but a complete version of the paper with high resolution figures can be downloaded from (http://www.mrao.cam.ac.uk/~graca/topol/

Efecto de la competencia de las malezas sobre el crecimiento, desarrollo y producción de dos clones de plátano (Musa AAB Simmonds).

El experimento se realizó entre diciembre 1985 y febrero 1987, en Palmira (Colombia), a 1001 m.s.n.m. Las malezas predominantes en el campo fueron: caminadora (Rotboellia cochinchinensis Lour.), verdolaga (Portulaca oleracea L.), batatillas (Ipomoea spp.) y cachorro (Cenchrus brownii Roem, Schutt.). En las plantas que se desarrollaron sin control de malezas hubo disminución del crecimiento perimetral del seudotallo, retraso en la iniciación floral y un período mayor entre la siembra y la cosecha de los racimos, en los dos clones estudiados. La competencia de las malezas redujo la producción de racimos del Dominico-Hartón, lo cual no ocurrió en el Hartón. La interferencia de las malezas no afectó significativamente el número de manos, peso y grosor del frutoPlátano-Musa sapientu

Influencia de la exposición de las hojas y el epicarpio de frutos sobre el desarrollo y la calidad del racimo de plátano 'hartón' (musa aab simmonds)

Se estudió la influencia y contribución de las hojas funcionales presentes y el epicarpio del fruto durante el desarrollo del racimo sobre las características físicas y la calidad de los frutos de plátano 'Hartón' en el departamento de Córdoba (Colombia). Se usó un diseño de bloques completamente al azar, tres repeticiones y 10 tratamientos (cubrimiento de los tercios foliares y la inflorescencia). El número de hojas presentes durante el llenado del racimo afectó significativamente el peso, la longitud y el grosor de los frutos, mientras que el periodo de llenado de estos no se afectó. Se obtuvieron frutos de buena calidad para la exportación con un número mínimo de 6 hojas funcionales. En la maduración de los frutos, la concentración en la pulpa de los sólidos solubles totales (°Brix) fue afectada significativamente, pero no el contenido de almidón

Endófitos asociados a la raíz de Musa spp. pueden actuar como microorganismos benéficos, promover el crecimiento de las plantas e inhibir patógenos.

El uso de cultivo de tejidos (TC) en el material de siembra es una práctica de manejo recomendadas en el banano en todo el mundo para evitar la dispersión de la enfermedad. Sin embargo, endófitos (bacterias y hongos), conocidos para proporcionar beneficios a las plantas de banano, se eliminan durante el proceso de TC. El enriquecimiento de material vegetal proveniente de TC es visto como una estrategia prometedora frente a la resistencia a enfermedades, pero el éxito requiere una comprensión de las complejas relaciones de endófitos

Making Maps Of The Cosmic Microwave Background: The MAXIMA Example

This work describes Cosmic Microwave Background (CMB) data analysis algorithms and their implementations, developed to produce a pixelized map of the sky and a corresponding pixel-pixel noise correlation matrix from time ordered data for a CMB mapping experiment. We discuss in turn algorithms for estimating noise properties from the time ordered data, techniques for manipulating the time ordered data, and a number of variants of the maximum likelihood map-making procedure. We pay particular attention to issues pertinent to real CMB data, and present ways of incorporating them within the framework of maximum likelihood map-making. Making a map of the sky is shown to be not only an intermediate step rendering an image of the sky, but also an important diagnostic stage, when tests for and/or removal of systematic effects can efficiently be performed. The case under study is the MAXIMA data set. However, the methods discussed are expected to be applicable to the analysis of other current and forthcoming CMB experiments.Comment: Replaced to match the published version, only minor change

Development and maturation of fruits of two indupalma oxg hybrids (elaeis oleifera x elaeis guineensis)

OxG hybrids are materials with characteristics notable fortolerance to pests and diseases, high quality oil and acceptablebunch production, but the physiological processes of growthand maturation of the fruits are not well known. For the twohybrid materials (Coarí x La Mé and Sinú-Coarí x La Mé), thephysiological and biochemical changes during the growth andmaturation of the bunches were studied in San Alberto, Cesar(Colombia) with a climate of 2,497 mm/year precipitation and27°C. Female inflorescences in anthesis were selected and thechanges in size, color, and oil content of the external, internaland red parthenocarpic fruits of the bunches were recordedfrom 98 days after anthesis (DAA). A completely randomexperimental design was used with five replications and 13sample dates. In hybrid Coarí x La Mé, 70% of the oil in thefruits accumulated between 98 and 126 DAA and reached themaximum at 168 DAA, while in hybrid Sinú-Coarí x La Mé,more than 90% of the oil accumulated between 98 and 140DAA, also reaching the maximum at 168 DAA. The external,internal and red parthenocarpic fruits of the bunches reachedthe maximum percentages of oil/dry mesocarp at the sametime (day). It is possible to estimate the percentage of oil/moistmesocarp based on the moisture percentage of fresh fruits

Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Are There Cosmic Microwave Background Anomalies?

(Abridged) A simple six-parameter LCDM model provides a successful fit to WMAP data, both when the data are analyzed alone and in combination with other cosmological data. Even so, it is appropriate to search for any hints of deviations from the now standard model of cosmology, which includes inflation, dark energy, dark matter, baryons, and neutrinos. The cosmological community has subjected the WMAP data to extensive and varied analyses. While there is widespread agreement as to the overall success of the six-parameter LCDM model, various "anomalies" have been reported relative to that model. In this paper we examine potential anomalies and present analyses and assessments of their significance. In most cases we find that claimed anomalies depend on posterior selection of some aspect or subset of the data. Compared with sky simulations based on the best fit model, one can select for low probability features of the WMAP data. Low probability features are expected, but it is not usually straightforward to determine whether any particular low probability feature is the result of the a posteriori selection or of non-standard cosmology. We examine in detail the properties of the power spectrum with respect to the LCDM model. We examine several potential or previously claimed anomalies in the sky maps and power spectra, including cold spots, low quadrupole power, quadropole-octupole alignment, hemispherical or dipole power asymmetry, and quadrupole power asymmetry. We conclude that there is no compelling evidence for deviations from the LCDM model, which is generally an acceptable statistical fit to WMAP and other cosmological data.Comment: 19 pages, 17 figures, also available with higher-res figures on http://lambda.gsfc.nasa.gov; accepted by ApJS; (v2) text as accepte

Foreground influence on primordial non-Gaussianity estimates: needlet analysis of WMAP 5-year data

We constrain the amplitude of primordial non-Gaussianity in the CMB data taking into account the presence of foreground residuals in the maps. We generalise the needlet bispectrum estimator marginalizing over the amplitudes of thermal dust, free-free and synchrotron templates. We apply our procedure to WMAP 5 year data, finding fNL= 38\pm 47 (1 \sigma), while the analysis without marginalization provides fNL= 35\pm 42. Splitting the marginalization over each foreground separately, we found that the estimates of fNL are positively cross correlated of 17%, 12% with the dust and synchrotron respectively, while a negative cross correlation of about -10% is found for the free-free component.Comment: Submitted to MNRA