Ensayo de regresión lineal entre densidades de residencias secundarias y proximidad a la costa en Mallorca.

Sin resume

Star formation rates and chemical abundances of emission line galaxies in intermediate-redshift clusters

We examine the evolutionary status of luminous, star-forming galaxies in intermediate-redshift clusters by considering their star formation rates and the chemical and ionsiation properties of their interstellar emitting gas. Our sample consists of 17 massive, star-forming, mostly disk galaxies with M_{B}<-20, in clusters with redshifts in the range 0.31< z <0.59, with a median of =0.42. We compare these galaxies with the identically selected and analysed intermediate-redshift field sample of Mouhcine et al. (2006), and with local galaxies from the Nearby Field Galaxy Survey of Jansen et al. (2000). From our optical spectra we measure the equivalent widths of OII, Hbeta and OIII emission lines to determine diagnostic line ratios, oxygen abundances, and extinction-corrected star formation rates. The star-forming galaxies in intermediate-redshift clusters display emission line equivalent widths which are, on average, significantly smaller than measured for field galaxies at comparable redshifts. However, a contrasting fraction of our cluster galaxies have equivalent widths similar to the highest observed in the field. This tentatively suggests a bimodality in the star-formation rates per unit luminosity for galaxies in distant clusters. We find no evidence for further bimodalities, or differences between our cluster and field samples, when examining additional diagnostics and the oxygen abundances of our galaxies. This maybe because no such differences exist, perhaps because the cluster galaxies which still display signs of star-formation have recently arrived from the field. In order to examine this topic with more certainty, and to further investigate the way in which any disparity varies as a function of cluster properties, larger spectroscopic samples are needed.Comment: 10 pages, 6 figures, MNRAS in pres

The Tully-Fisher relation of intermediate redshift field and cluster galaxies from Subaru spectroscopy

We have carried out spectroscopic observations in 4 cluster fields using Subaru's FOCAS multi-slit spectrograph and obtained spectra for 103 bright disk field and cluster galaxies at $0.06 \le z \le 1.20$. Seventy-seven of these show emission lines, and 33 provide reasonably-secure determinations of the galaxies' rotation velocity. The rotation velocities, luminosities, colours and emission-line properties of these galaxies are used to study the possible effects of the cluster environment on the star-formation history of the galaxies. Comparing the Tully-Fisher relations of cluster and field galaxies at similar reshifts we find no measurable difference in rest-frame $B$-band luminosity at a given rotation velocity (the formal difference is $0.18\pm0.33$mag). The colours of the cluster emission line galaxies are only marginally redder in rest-frame $B-V$ (by $0.06\pm0.04$mag) than the field galaxies in our sample. Taken at face value, these results seem to indicate that bright star-forming cluster spirals are similar to their field counterparts in their star-formation properties. However, we find that the fraction of disk galaxies with absorption-line spectra (i.e., with no current star formation) is larger in clusters than in the field by a factor of $\sim3$--5. This suggests that the cluster environment has the overall effect of switching off star formation in (at least) some spiral galaxies. To interpret these observational results, we carry out simulations of the possible effects of the cluster environment on the star-formation history of disk galaxies and thus their photometric and spectroscopic properties. Finally, we evaluate the evolution of the rest-frame absolute $B$-band magnitude per unit redshift at fixed rotation velocity.Comment: 21 pages, 13 figures, accepted for publication in MNRA

Analysis of Activities with ICT in Secondary Education Classrooms

MetNum es punto de encuentro en el campus virtual Moodle, para los alumnos de Métodos Numéricos de la I.T.Informática de la Universidad de Málaga. Como herramientas básicas de Moodle nos planteamos en este campus virtual la utilización de cuestionarios, lecciones, glosarios, tareas, wikis, libros y foros como medio de incentivar y encauzar el trabajo diario de los alumnos. Destacamos que se ha desarrollado PDTeXInT: un entorno para el diseño de tutoriales interactivos para la presentación de material matemático. PDTeXInT permite acercar de forma amistosa y formato portable los contenidos teóricos junto con ejercicios de autoevaluación, como método para mejorar el proceso de aprendizaje.An cases study has made in two Secondary Education Centres of Tenerife, integrated into the Project Medusa of the Canary Government (http://www.gobiernodecanarias.org/educacion/ medusa). The results obtained from the observations of many classrooms developed teaching activities supported in the use of digital resources are presented here. The central objective was to identify what kind of activities have been developed in the pedagogical use of ICT, to what extent these activities are favoring informational and digital skills in students, and how they organized and developed them

El ser humano y la tecnología

Sin resumen

B3 0003+387: AGN Marked Large-Scale Structure at z=1.47?

We present evidence for a significant overdensity of red galaxies, as much as a factor of 14 over comparable field samples, in the field of the z=1.47 radio galaxy B3 0003+387. The colors and luminosities of the brightest red galaxies are consistent with their being at z>0.8. The radio galaxy and one of the red galaxies are separated by 5" and show some evidence of a possible interaction. However, the red galaxies do not show any strong clustering around the radio galaxy nor around any of the brighter red galaxies. The data suggest that we are looking at a wall or sheet of galaxies, possibly associated with the radio galaxy at z=1.47. Spectroscopic redshifts of these red galaxies will be necessary to confirm this large-scale structure.Comment: 19 pages, 7 figures, LaTeX2e/AASTeX v5.0.2. The full photometric catalog is included as a separate deluxetable file. To appear in the Astronomical Journal (~Nov 00

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

Contenido de metales en muestras biológicas de la isla Rocuant, bahía Concepción, Chile

The presence of heavy metals in organisms tissues from the Rocuant Island, Concepcion Bay, is analyzed. The study was&nbsp;carried out on the bivalve Tagelus dombeii (“navajuela”), Mulinia edulis (“taquilla”), the seaweeds Gracilaria chilensis&nbsp;(“pelillo”) and Rhodymenia sp (“rodymenia”) and the fi sh Stromateus stellatus (“pampanito “). The metals analyzed were&nbsp;Cd, Fe, Hg, Pb and Zn and there were no previous records in the locality. The sampling for benthic organisms was carried&nbsp;out by “hooka” diving, while fi sh were caught using a fi shing nets. In general, metals concentrations are comparable to&nbsp;values reported in the literature for the same species in other areas of central Chilean coast. This suggests they refl ect a&nbsp;natural condition and the levels of Cd, Hg and Pb in the bivalve mollusks are under the acceptance levels for products to&nbsp;export. It should be noticed that Pb content in these organisms is under the analytical detection limits in all organisms,&nbsp;as well as Cd in the fi sh S. stellatus and the seaweeds G. chilensis. The Fe content in Rhodymenia sp. shows the highest&nbsp;absolute value of the whole study.Se analiza la presencia de metales pesados en tejidos de organismos provenientes del sector aledaño a Isla Rocuant, Bahía&nbsp;Concepción. Los organismos estudiados fueron los bivalvos bentónicos Tagelus dombeii (“navajuela”), Mulinia edulis&nbsp;(“taquilla”), las macroalgas Gracilaria chilensis (“pelillo”) y Rhodymenia sp (“rodymenia”) y el pez Stromateus stellatus&nbsp;(“pampanito”). Los metales analizados en sus tejidos fueron Cd, Fe, Hg, Pb y Zn para los cuales no existen registros&nbsp;previos en la localidad. La obtención de las muestras fue realizada por medio de buceo “hooka” para los organismos&nbsp;bentónicos, mientras que los peces fueron capturados mediante redes de pesca. En general, los metales encontrados&nbsp;presentan concentraciones comparables con los valores reportados en la literatura para las misma especies, pero en otras&nbsp;localidades, por lo que refl ejan una condición natural, indicando además que los niveles de Cd, Hg y Pb en los moluscos&nbsp;bivalvos se encuentran bajo los niveles de aceptación para productos de exportación. Se destaca además que en el casodel Pb, este se encuentra bajo los niveles de detección analíticas en todos los organismos, al igual que el Cd en el pez S.&nbsp;stellatus y el alga G. chilensis. Otra diferencia que resalta corresponde a la presencia de Fe en Rhodymenia sp. que presenta&nbsp;el mayor valor absoluto de todo el estudio

Observaciones hidrograficas en Bahia Foster y Bahia Chile (Islas Shetland del Sur) enero 1978

The hydrographical conditions founded in Port Foster (Deception Island) and Chile Bay (Greenwich Island) both belong to the South Shetlands Islands group, Antarctic Peninsula, has been described. This survey has been carried out from the Chilean Navy Oceanographic vessel "YELCHO" in January 1978. An stratification in the area closed with the Antarctic surface waters has been observed. The temperature ranged between -1,60 º C to 1,30º C in Port Foster and 0,46ºC to 1,70ºC in Chile Bay; the salinity ranged between 33.80 to 34,24 in Port Foster and 33,61 to 34 in Chile Bay; the dissolved oxygen varied between 3,47 to 7,02 ml O2/l in both area. The characteristic density (Sigma t) of Antarctic Surface waters in the area, i.e., 26,92 and 27,58 has been observed

pH-Dependent Fluorescent Probe That Can Be Tuned for Cysteine or Homocysteine

The very close structural similarities between cysteine and homocysteine present a great challenge to achieve their selective detection using regular fluorescent probes, limiting the biological and pathological studies of these two amino thiols. A coumarin-based fluorescent probe was designed featuring pH-promoted distinct turn-on followed by ratiometric fluorescence responses for Cys and turn-on fluorescence response for Hcy through two different reaction paths. These specific responses demonstrate the activity differences between Cys and Hcy qualitatively for the first time. The probe could also be used for Cys and Hcy imaging in living cells