1,190 research outputs found

    Exploring the evolutionary paths of the most massive galaxies since z~2

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    We use Spitzer MIPS data from the FIDEL Legacy Project in the Extended Groth Strip to analyze the stellar mass assembly of massive (M>10^11 M_sun) galaxies at z<2 as a function of structural parameters. We find 24 micron emission for more than 85% of the massive galaxies morphologically classified as disks, and for more than 57% of the massive systems morphologically classified as spheroids at any redshift, with about 8% of sources harboring a bright X-ray and/or infrared emitting AGN. More noticeably, 60% of all compact massive galaxies at z=1-2 are detected at 24 micron, even when rest-frame optical colors reveal that they are dead and evolving passively. For spheroid-like galaxies at a given stellar mass, the sizes of MIPS non-detections are smaller by a factor of 1.2 in comparison with IR-bright sources. We find that disk-like massive galaxies present specific SFRs ranging from 0.04 to 0.2 Gyr^-1 at z<1 (SFRs ranging from 1 to 10 M_sun/yr), typically a factor of 3-6 higher than massive spheroid-like objects in the same redshift range. At z>1, and more pronouncedly at z>1.3, the median specific SFRs of the disks and spheroids detected by MIPS are very similar, ranging from 0.1 to 1 Gyr^-1 (SFR=10-200 M_sun/yr). We estimate that massive spheroid-like galaxies may have doubled (at the most) their stellar mass from star-forming events at z<2: less than 20% mass increase at 1.7<z<2.0, up to 40% more at 1.1<z<1.7, and less than 20% additional increase at z<1. Disk-like galaxies may have tripled (at the most) their stellar mass at z<2 from star formation alone: up to 40% mass increase at 1.7<z<2.0, and less than 180% additional increase below z=1.7 occurred at a steady rate.Comment: Accepted for publication in ApJ; 10 pages, 5 figures, 1 tabl

    Anomalous circular polarization profiles in the He I 1083.0 nm multiplet from solar spicules

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    We report Stokes vector observations of solar spicules and a prominence in the He I 1083 nm multiplet carried out with the Tenerife Infrared Polarimeter. The observations show linear polarization profiles that are produced by scattering processes in the presence of a magnetic field. After a careful data reduction, we demonstrate the existence of extremely asymmetric Stokes V profiles in the spicular material that we are able to model with two magnetic components along the line of sight, and under the presence of atomic orientation in the energy levels that give rise to the multiplet. We discuss some possible scenarios that can generate the atomic orientation in spicules. We stress the importance of spectropolarimetric observations across the limb to distinguish such signals from observational artifacts.Comment: accepted for publication in Ap

    PROCEDIMIENTO DE ENFERMERÍA: "CURAS DE HERIDAS AGUDAS Y CRÓNICAS CON EL FILETE DE ALOE VERA"

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    Aloe Vera, especially The Canarian variety, is a plant that has been known for thousands of years for its enormous healing properties. Throughout time there have been many testimonials to its healing powers. Aloe Vera´s miraculous healing powers originate from its two hundred active substances. Including vitamins, minerals, aminoacids, polysaccharides, enzymes, etc. The synergy of these components produces results impossible to obtain from other known treatments. Given its curative,anti inflammatory,analgesic and debridement qualities some of the nurses at the Public Health Centre in Vecindario,have been using the Aloe Vera plant to cure acute and chronicle wounds for several years now. The good results obtained,the low costs of the treatment and the approval of both patients and nurs-ing staff,justifies the continued and amplified use of Aloe Vera as an option in treatment. For this reason we are doing a comprehensive study of the Spanish bibliography so that all relative criteria can be unified.El aloe vera, en especial la variedad canaria, es una planta milenaria conocida desde la antigüedad por sus grandes propiedades curativas siendo muchísimas las citas que así lo avalan. El poder ‘milagroso’ del aloe radica en las 200 sustancias activas que contiene, entre las que se incluyen vitaminas, minerales, aminoácidos, polisacáridos, enzimas, etc. La sinergia entre todos estos componentes produce efectos imposibles de igualar por otros tratamientos conocidos. Dado el poder cicatrizante, antiinflamatorio, analgésico y desbridante, algunas enfermeras del Centro de Salud de Vecindario hacemos curas de heridas agudas y crónicas con la planta de aloe vera desde hace varios años. Los buenos resultados obtenidos, el bajo coste del tratamiento y la buena aceptación de los usuarios y las enfermeras justifican la necesidad de hacer un procedimiento de enfermería para las curas con aloe vera como una herramienta útil de trabajo (ya que hemos observado diferentes formas de uso del aloe, tanto en enfermería como en la población). Para ello hacemos una revisión exhaustiva de la bibliografía en español y de esta manera unificar criterios

    Measuring star formation in high-z massive galaxies: A mid-infrared to submillimeter study of the GOODS NICMOS Survey sample

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    We present measurements of the mean mid-infrared-to-submillimeter flux densities of massive (M\ast \approx 2 \times 10^11 Msun) galaxies at redshifts 1.7 < z < 2.9, obtained by stacking positions of known objects taken from the GOODS NICMOS Survey (GNS) catalog on maps: at 24 {\mu}m (Spitzer/MIPS); 70, 100, and 160{\mu}m (Herschel/PACS); 250, 350, 500{\mu}m (BLAST); and 870{\mu}m (LABOCA). A modified blackbody spectrum fit to the stacked flux densities indicates a median [interquartile] star-formation rate of SFR = 63 [48, 81] Msun yr^-1 . We note that not properly accounting for correlations between bands when fitting stacked data can significantly bias the result. The galaxies are divided into two groups, disk-like and spheroid-like, according to their Sersic indices, n. We find evidence that most of the star formation is occurring in n \leq 2 (disk-like) galaxies, with median [interquartile] SFR = 122 [100,150] Msun yr^-1, while there are indications that the n > 2 (spheroid-like) population may be forming stars at a median [interquartile] SFR = 14 [9,20] Msun yr^-1, if at all. Finally, we show that star formation is a plausible mechanism for size evolution in this population as a whole, but find only marginal evidence that it is what drives the expansion of the spheroid-like galaxies.Comment: Accepted by MNRAS. 10 pages, 3 figures, 3 table

    Agroecological analysis of cucumber (Cucumis sativus L.) crops in orchards in a Mediterranean environment

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    If adaptability is defined as the ability of a crop (or variety) to respond positively to changes in agricultural conditions, the purpose of this study was to explore the adaptability and relative influence of environmental factors on Cucumber Sativus L. to a specific Mediterranean environmental and agroecological site: Huete (Cuenca, Central Spain). Cucumber requires high temperatures and soil moisture for a satisfactory yield and maintaining an optimum level of humidity is very favorable, which is easy to achieve for farmers in Huete. Abundant sunshine is needed and this is another reason to cultivate during the summer period; it is estimated that there were between 2700 and 2800 hours of sunshine in the Huete area. The study described here revealed that the soils are poorly developed and evolved, with a simple Ap-C or Ap-Bw-C morphology. The soils are friable, slightly adherent and somewhat dry and hard. A significant feature is the presence of good drainage and appreciable effective depth. Like other crops, cucumber plants are preferably grown on loose, well-drained soils, such as the soils studied here. Huete cucumber seems able to tolerate certain levels of soil salinity when compared to other species. The cucumbers are irrigated with water with moderate electrical conductivity without an appreciable decrease in yield. Small doses of salinity may be one of the factors that leads to the characteristics associated with Huete cucumber, an aspect that would need to be investigated more deeply. Substrate nutrients and moisture management are two major concerns regarding Cucumber Sativus L. crops in Huete. Elemental chemical analysis revealed that strontium abounds and this is attributed to the presence of this element in the gypsums. The results of this study open a new horizon in the study of the aptitude of the land and represent a useful step towards the specific site and, consequently, the sustainable management of land under cucumber cultivation. Further research into a wider range of soils, fertilizer compositions and release rates is require

    Renal Morphology, Clinical Findings, and Progression Rate in Mesoamerican Nephropathy

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    BackgroundMesoamerican nephropathy (MeN) is a chronic kidney disease affecting rural inhabitants in Central America. We have previously described the renal morphology in 8 patients from El Salvador. To confirm the renal pathology, we have studied kidney biopsies from patients with MeN in Nicaragua. Follow-up urine and blood samples from both biopsy studies were collected to investigate the natural history

    Haloalkalitolerant Actinobacteria with capacity for anthracene degradation isolated from soils close to areas with oil activity in the State of Veracruz, Mexico

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    The use of native strains of microorganisms from soils is an excellent option for bioremediation. To our knowledge, until now there has been no other group working on the isolation of Actinobacteria from contaminated soils in Mexico. In this study, samples of soils close to areas with oil activity in the State of Veracruz, Mexico, were inoculated for the isolation of Actinobacteria. The strains isolated were characterized morphologically, and the concentrations of NaCl and pH were determined for optimal growth. Strain selection was performed by the detection of a phylogenetic marker for Actinobacteria located at the 23S rRNA gene, followed by species identification by sequencing the 16S rRNA gene. Several haloalkalitolerant Actinobacteria were isolated and identified as: Kocuria rosea, K. palustris, Microbacterium testaceum, Nocardia farcinica and Cellulomonas denverensis. Except for C. denverensis, the biomass of all strains increased in the presence of anthracene. The strains capacity to metabolize anthracene (at 48 h), determined by fluorescence emission, was in the range of 46&ndash;54%. During this time, dihydroxy aromatic compounds formed, characterized by attenuated total reflectance Fourier transform infrared spectroscopy bands of 1205 cm&ndash;1 and 1217 cm&ndash;1. Those Actinobacteria are potentially useful for the bioremediation of saline and alkaline environments contaminated with polycyclic aromatic hydrocarbon compounds. [Int Microbiol 2016; 19(1):15-26]Keywords: Kocuria &middot; Microbacterium &middot; haloalkalitolerant Actinobacteria &middot; anthracene degradation &middot; State of Veracruz, Mexic

    SELECTIVIDAD DE LAS ISOFORMAS DE 140-180 KDA DE NCAM EN LA PAPILA ÓPTICA DEL EMBRIÓN DE POLLO

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    During embryonic development of chicken retina and retinotectal proyection, neural cells showed spatiotemporal patterns in the glycosidic residues located in the plasmatic membranes. Those glycidic components are related with adhesion and recognition cellular behaviours during the generation of nervous system cytoarchitecture. Thus those sugars are included both in usual glycoproteins as in a group of molecules called as cell adhesion molecules (CAM). The first isolated molecule in this group was the neural cell adhesion molecule (NCAM). This glycoprotein has a proteic core with diverse isoforms and it has a variable sialic acids chain. It was able to determine that 120 kDa NCAM isoform shows scarcely sialized chains in intermediate stages by using conventional techniques, lectins and immunohistochemistry. Meanwhile 140-180 kDa NCAM isoforms possess high content in sialic acid and they are present both in early and final stages. Other authors reported that human 120 kDa NCAM isoform was similar to that observed in the Gallus domesticus retina. Our results showed that 140- 180kDa isoforms were only presented in the nerve optic fibers when they were left the optic disc.Durante la embriogénesis de la retina del Gallus domesticus, los neuroblastos muestran variaciones temporales y espaciales de los residuos glucosilados a nivel de sus membranas plasmáticas. Se considera que estos componentes glucídicos están implicados en la organización de estructuras neurales inmaduras, mediante su participación en mecanismos de reconocimiento y adhesión celulares. Los componentes glucosilados van a formar parte de glucoproteínas convencionales, así como de un grupo de moléculas a las que genéricamente se han denominado moléculas de adhesión celular. La primera de estas moléculas aislada fue la neural cell adhesion molecule (NCAM), glucoproteína compuesta por un armazón proteico con diversas isoformas y una cadena más o menos variable de polímeros de ácidos siálicos. La combinación de técnicas convencionales his- toquímicas, de lectinas e inmunocitoquímicas han permitido determinar que las moléculas de NCAM de 120 kDa presentan cadenas pobremente sializadas en estadíos intermedios del desarrollo, mientras en estadíos tempranos y finales los ácidos siálicos están más abundantemente representados en las isoformas de 140-180 kDa. Algunos autores han determinado que la isoforma de NCAM presente durante el desarrollo de la retina del Gallus domesticus es similar a la humana de 120 kDa. Nuestros resultados indican que las isoformas de 140-180 kDa sólo se presentan en las fibras del nervio óptico una vez que estas abandonan la papila óptica

    The hidden HI-massive LIRG HIZOA J0836-43: Inside-out galaxy formation

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    HIZOA J0836-43 is an extreme gas-rich (MHIM_{\rm{HI}}=7.5\times10^{10} M_{\sun}) disk galaxy which lies hidden behind the strongly obscuring Vela region of the Milky Way. Utilizing observations from the {\it Spitzer Space Telescope}, we have found it to be a luminous infrared starburst galaxy with a star formation rate of \sim 21 M_{\sun} \rm{yr^{-1}}, arising from exceptionally strong molecular PAH emission (L_{7.7\micron} = 1.50 \times 10^{9} L_{\odot}) and far-infrared emission from cold dust. The galaxy exhibits a weak mid-infrared continuum compared to other starforming galaxies and U/LIRGs. This relative lack of emission from small grains suggests atypical interstellar medium conditions compared to other starbursts. We do not detect significant [[Ne {\sc v}]] or [[O {\sc iv}]], which implies an absent or very weak AGN. The galaxy possesses a prominent bulge of evolved stars and a stellar mass of 4.4(±\pm1.4)\times10^{10} M_{\sun}. With its plentiful gas supply and current star formation rate, a doubling of stellar mass would occur on a timescale of \sim2 Gyr. Compared to local galaxies, HIZOA J0836-43 appears to be a "scaled-up" spiral undergoing inside-out formation, possibly resembling stellar disk building processes at intermediate redshifts.Comment: 5 pages, 3 figures, 1 table; Accepted for publication in ApJL: August 25 2008. A version with full resolution figures is available at http://spider.ipac.caltech.edu/staff/jarrett/Cluver_ApJL.pd

    Respuesta agronómica de diferentes cultivares tintos de vid en zona templada

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    Se presenta la respuesta varietal de 6 cultivares tintos de vid, con riego deficitario controlado, en zona cálida: Barbera, Graciano, Mencía, Pinot noir, Petit verdot y Tempranillo. Teniendo en cuenta que en zona cálida hay que escoger cultivares de ciclo largo, recolección tardía, capaces de madurar manteniendo alta la acidez real y total, se concluye que los más idóneos para su cultivo en zona cálida son Barbera, por su alta acidez y Petit verdot y Graciano por su larga maduración y acidez equilibrada. Tempranillo, si bien en este trabajo presenta una respuesta adecuada, para equivalente maduración sacarimétrica a las anteriores posee menor acidez e IPT. Mencía madura mejor en situaciones frescas que en zona cálid
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