Cultivos urbanos en un aula de matemáticas inclusiva

En el presente trabajo se describe un proyecto de aula en curso en un aula inclusiva-, el cual hace referencia a la realización de cultivos urbanos, este trabajo se describe en 4 fases en las cuales se desarrollan conceptos y nociones matemáticas

The Deficit of Distant Galaxy Clusters in the RIXOS X-ray Survey

Clusters of galaxies are the largest gravitationally bound systems and therefore provide an important way of studying the formation and evolution of the large scale structure of the Universe. Cluster evolution can be inferred from observations of the X-ray emission of the gas in distant clusters, but interpreting these data is not straightforward. In a simplified view, clusters grow from perturbations in the matter distribution: their intracluster gas is compressed and shock-heated by the gravitational collapse$^{1}$. The resulting X-ray emission is determined by the hydrostatic equilibrium of the gas in the changing gravitational potential. However, if processes such as radiative cooling or pre-collapse heating of the gas are important, then the X-ray evolution will be strongly influenced by the thermal history of the gas. Here we present the first results from a faint flux-limited sample of X-ray selected clusters compiled as part of the ROSAT International X-ray and Optical Survey (RIXOS). Very few distant clusters have been identified. Most importantly, their redshift distribution appears to be inconsistent with simple models based on the evolution of the gravitational potential. Our results suggest that radiative cooling or non-gravitational heating of the intracluster gas must play an important role in the evolution of clusters.Comment: uuencoded compressed postscript. The preprint is also available at http://www.ast.cam.ac.uk/preprint/PrePrint.htm

On the Optimization of Broad-Band Photometry for Galaxy Evolution Studies

We have derived the uncertainties to be expected in the derivation of galaxy physical properties (star formation history, age, metallicity, reddening) when comparing broad-band photometry to the predictions of evolutionary synthesis models. We have obtained synthetic colors for a large sample (9000) of artificial galaxies assuming different star formation histories, ages, metallicities, reddening values, and redshifts. The colors derived have been perturbed by adopting different observing errors, and compared back to the evolutionary synthesis models grouped in different sets. The comparison has been performed using a combination of Monte Carlo simulations, a Maximum Likelihood Estimator and Principal Component Analysis. After comparing the input and derived output values we have been able to compute the uncertainties and covariant degeneracies between the galaxy physical properties as function of (1) the set of observables available, (2) the observing errors, and (3) the galaxy properties themselves. In this work we have considered different sets of observables, some of them including the standard Johnson/Cousins (UBVRI) and Sloan Digital Sky Survey (SDSS) bands in the optical, the 2 Micron All Sky Survey (2MASS) bands in the near-infrared, and the Galaxy Evolution Explorer (GALEX) bands in the UV, at three different redshifts, z=0.0, 0.7, and 1.4. This study is intended to represent a basic tool for the design of future projects on galaxy evolution, allowing an estimate of the optimal band-pass combinations and signal-to-noise ratios required for a given scientific objective.Comment: 20 pages, 9 postscript figures, 3 tables, accepted for publication in A

The host galaxy of GRB010222: The strongest damped Lyman-alpha system known

Analysis of the absorption lines in the afterglow spectrum of the gamma-ray burst GRB010222 indicates that its host galaxy (at a redshift of z=1.476) is the strongest damped Lyman-alpha (DLA) system known, having a very low metallicity and modest dust content. This conclusion is based on the detection of the red wing of Lyman-alpha plus a comparison of the equivalent widths of ultraviolet Mg I, Mg II, and Fe II lines with those in other DLAs. The column density of H I, deduced from a fit to the wing of Lyman-alpha, is (5 +/- 2) 10^22 cm^-2. The ratio of the column densities of Zn and Cr lines suggests that the dust content in our line of sight through the galaxy is low. This could be due to either dust destruction by the ultraviolet emission of the afterglow or to an initial dust composition different to that of the diffuse interstellar material, or a combination of both.Comment: Submitted to MNRAS 12 page

Climate change and growing megacities: hazards and vulnerability

This paper is a review of geophysical and climatic trends associated with extreme weather events and natural hazards, their implications for urban areas and the effects of continued environmental modification due to urban expansion. It discusses how urban design, technological development and societal behaviour can either ameliorate or worsen climate-induced hazards in urban areas. Pressures – ranging from excessive rainfall causing urban flooding to urban temperature extremes driving air pollution – require more attention to understand, model and predict changes in hazards in urban areas. It concludes that involving different techniques for data analysis and system modelling is more appropriate for practical decision-making than a purely reductionist approach. Successfully determining the future environment of megacities will, however, require joint action with societally informed decision makers, grounded in sound scientific achievements

An Optical/Near-Infrared Study of Radio-Loud Quasar Environments II. Imaging Results

We use optical and near-IR imaging to examine the properties of the significant excess population of K>=19 galaxies found in the fields of 31 z=1-2 radio-loud quasars by Hall, Green & Cohen (1998). The excess occurs on two spatial scales: a component at <40'' from the quasars significant compared to the galaxy surface density at >40'' in the same fields, and a component roughly uniform to ~100'' significant compared to the galaxy surface density seen in random-field surveys in the literature. The r-K color distributions of the excess galaxy populations are indistinguishable and are significantly redder than the color distribution of the field population. The excess galaxies are consistent with being predominantly early-type galaxies at the quasar redshifts, and there is no evidence that they are associated with intervening MgII absorption systems. The average excess within 0.5 Mpc (~65'') of the quasars corresponds to Abell richness class ~0 compared to the galaxy surface density at >0.5 Mpc from the quasars, and to Abell richness class ~1.5 compared to that from the literature. We discuss the spectral energy distributions (SEDs) of galaxies in fields with data in several passbands. Most candidate quasar-associated galaxies are consistent with being 2-3 Gyr old early-types at the quasar redshifts of z~1.5. However, some objects have SEDs consistent with being 4-5 Gyr old at z~1.5, and a number of others are consistent with ~2 Gyr old but dust-reddened galaxies at the quasar redshifts. These potentially different galaxy types suggest there may be considerable dispersion in the properties of early-type cluster galaxies at z~1.5. There is also a population of galaxies whose SEDs are best modelled by background galaxies at z>2.5.Comment: Accepted to ApJ; 54 pages including 30 figures; 2 color GIF files available separately; also available from http://www.astro.utoronto.ca/~hall/thesis.htm

Study of the interaction between fog and turbulence

Póster elaborado para la European Geosciences Union General Assembly, celebrada en Viena del 3 al 8 de abril de 2011.This researchh as been funded by the Spanish Ministry of Education and Science (projects CGL2006-12474-C03-03 and CGL2009-12797-C03-03).The GR58/08 program (supported by BSCH and UCM) has also partially financed whis work through the Research Group “Micrometeorology and Climate Variability” (nº910437)

Estrogen-related genes and postmenopausal osteoporosis risk

Background To date, more than 150 candidate genes related to osteoporosis have been described, but osteoporosis has increasingly been considered a polygenic disease modulated by environmental factors. It is thought that osteoporosis predisposition, pathology, and treatment response depend on the interaction between different genes or between genes and environmental factors. Objective The aim of this study was to evaluate the relationship between the presence of single nucleotide polymorphisms (SNPs) in the estrogen metabolic pathway and the development of osteoporosis and to determine whether this relationship is monogenic or whether interactions between genes exist. Materials and methods A multicentric study with 1980 postmenopausal Spanish women in fi ve Spanish communities was conducted. The women completed a specifi c questionnaire that inquired about risk factors for osteoporosis. Data on participants ’ bone mineral density were obtained with dual-energy X-ray densitometers, and genetic data were obtained from frozen peripheral blood. Results The digenic protection combinations indicated involvement of the wild-type genotype (WT) of the 3 UTR marker for the CYP19A1 gene, the IVS4 marker of the same gene, and the BMP15 and FSHR genes. Among patients who carried two or more of the genotypes considered ‘ risky ’ , the triple combination among markers of the ESR2 and NRIP1 genes with any of the two mutations of the analyzed markers of the BMP15 gene gave a mean T -score value of 2.32 0.91 ( p 0.02). Conclusion Variants of the new candidate genes ( NRIP and BMP15 ) can predispose patients to osteoporosis