Validating the methodology for constraining the linear growth rate from clustering anisotropies

Redshift-space clustering distortions provide one of the most powerful probes to test the gravity theory on the largest cosmological scales. We perform a systematic validation study of the state-of-the-art statistical methods currently used to constrain the linear growth rate from redshift-space distortions in the galaxy two-point correlation function. The numerical pipelines are tested on mock halo catalogues extracted from large N-body simulations of the standard cosmological framework. We consider both the monopole and quadrupole multipole moments of the redshift-space two-point correlation function, as well as the radial and transverse clustering wedges, in the comoving scale range $10<r[$\Mpch$]<55$. Moreover, we investigate the impact of redshift measurement errors on the growth rate and linear bias measurements due to the assumptions in the redshift-space distortion model. Considering both the dispersion model and two widely-used models based on perturbation theory, we find that the linear growth rate is underestimated by about $5-10\%$ at $z30$ \Mpch, the discrepancy is reduced below $5\%$. At higher redshifts, we find instead an overall good agreement between measurements and model predictions. Though this accuracy is good enough for clustering analyses in current redshift surveys, the models have to be further improved not to introduce significant systematics in RSD constraints from next generation galaxy surveys. The effect of redshift errors is degenerate with the one of small-scale random motions, and can be marginalised over in the statistical analysis, not introducing any statistically significant bias in the linear growth constraints, especially at $z\geq1$.Comment: 17 pages, 14 figures, 1 tabl

Nonpuerperal Breast Infection

Objective: We undertook a microbiological study of purulent specimens from women with symptomatic breast abscesses

Galaxias enanas del grupo local

Las galaxias satélite de la Vía Láctea son de especial importancia para el estudio de la formación y evolución de galaxias, así como para el estudio de la materia oscura. En este artículo de revisión se presentan algunas propiedades estructurales del Grupo Local y de las galaxias enanas esferoidales que componen este sistema, con especial énfasis en las galaxias satélite de la Vía Láctea y su distribución espacial en el disco de satélites. Adicionalmente se presentan los estudios recientes más relevantes relacionados con el problema de la formación del disco de satélites de la Vía Láctea.The satellite galaxies of the Milky Way are very important both for the studies of the formation and evolution of galaxies and for the research on the dark matter problem. In the present review paper some structural properties of the Local Group, as well as of the dwarf spheroidal galaxies that compose this astrophysical system are presented. Special emphasis is paid to the satellite galaxies of the Milky Way and their spatial distribution on the disk of satellites (DoS). Furthermore, the more relevant recent studies related to the formation of the disk of satellites of the Milky Way are mentioned

Millennium Simulation Dark Matter Haloes: Multi-fractal and Lacunarity Analysis with Homogeneity Transition

We investigate from the fractal viewpoint the way in which the dark matter is grouped at z = 0 in the Millennium dark matter cosmological simulation. The determination of the cross to homogeneity in the Millennium Simulation data is described from the behaviour of the fractal dimension and the lacunarity. We use the sliding window technique to calculate the fractal mass-radius dimension, the pre-factor F and the lacunarity of this fractal relation. Besides, we determinate the multi-fractal dimension and the lacunarity spectrum, including their dependence with radial distance. This calculations show a radial distance dependency of all the fractal quantities, with heterogeneity clustering of dark matter haloes up to depths of 100 Mpc/h. The dark matter haloes clustering in the Millennium Simulation shows a radial distance dependency, with two regions clearly defined. The lacunarity spectrum for values of the structure parameter q >= 1 shows regions with relative maxima, revealing the formation of clusters and voids in the dark matter haloes distribution. With the use of the multi-fractal dimension and the lacunarity spectrum, the transition to homogeneity at depths between 100 Mpc/h and 120 Mpc/h for the Millennium Simulation dark matter haloes is detected.Comment: 13 pages, 9 figures, MNRAS - Accepte

Soil management and engineering for blue-green infrastructure

As urban areas continue to expand, the value of urban blue-green infrastructure (BGI) for increasing the social, environmental and economic sustainability of cities is increasingly recognised. However, there remains an inherent lack of knowledge and awareness around the fundamental contribution that soils make to the functioning of ecosystems within urban BGI. Urban landscapes are a nexus of environmental, engineered and socio-economic factors, which combine to create multifunctional spaces for people to live and work, all underpinned by the soil beneath us. In this chapter, we first outline the characteristics of urban soils and their importance for providing a range of beneficial ecosystem services, such as food production, flood mitigation, carbon storage and opportunities for recreation. We then highlight the key challenges and opportunities around the management and creation of soils within urban BGI. We conclude by emphasising the urgent need for better recognition of urban soils within planning policy and setting out a series of land-use specific management recommendations that will better enable urban soils to support the delivery of ecosystem services and, ultimately, enhance human health and wellbeing

Bottom-up control of common octopus Octopus vulgaris in the Galician upwelling system, northeast Atlantic Ocean

This paper investigates the possible underlying causes of the wide interannual fluctuations in catch of the common octopus Octopus vulgaris Cuvier, 1797 in one of the main small-scale fisheries off the coast of Galicia (northwest Spain). Galicia is at the northern boundary of the Iberian–Canary current upwelling system in the northeast Atlantic Ocean, where local winds induce seasonal upwelling, largely driving the annual cycles of primary and secondary production. We hypothesize that such dynamics are also fundamental for the survival of the planktonic stages of octopus and set the year class strength. We address this hypothesis by investigating the influence of upwelling on time-series of octopus fishery data. Wind stress structure during the spring–summer (prior to the hatching peak) and autumn–winter (during the planktonic stage) was found to affect the early life phase of this species, and explains up to 85% of the total variance of the year-to-year variability of the adult catch. Despite this bottom-up modulation via environmental conditions, our results also provide evidence for a between-cohort density-dependent interaction, probably caused by cannibalism and competition for habitat.Postprin