100 research outputs found

    A comparative study of the incidence of Alternaria Conidia in the atmosphere of five spanish cities

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    Lyman break and ultraviolet-selected galaxies at z ̃ 1-I. Stellar populations from the ALHAMBRA survey

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    We take advantage of the exceptional photometric coverage provided by the combination of GALEX data in the ultraviolet (UV) and the ALHAMBRA survey in the optical and near-infrared to analyse the physical properties of a sample of 1225 GALEX-selected Lyman break galaxies (LBGs) at 0.8 ≲ z ≲ 1.2 that are located in the COSMOS field. This is the largest sample of LBGs studied in this redshift range to date. According to a spectral energy distribution (SED) fitting with synthetic stellar population templates, we find that LBGs at z ̃ 1 are mostly young galaxies with a median age of 341 Myr and have intermediate dust attenuation, (Es(B - V)) ̃ 0.20. Owing to the selection criterion, LBGs at z ̃ 1 are UV-bright galaxies and have a high dust-corrected total star formation rate (SFR), with a median value of 16.9M⊙ yr-1. Their median stellar mass is log (M*/M⊙) = 9.74. We find that the dustcorrected total SFR of LBGs increases with stellar mass and that the specific SFR is lower for more massive galaxies (downsizing scenario). Only 2 per cent of the galaxies selected through the Lyman break criterion have an active galactic nucleus nature. LBGs at z ̃ 1 are located mostly over the blue cloud of the colour-magnitude diagram of galaxies at their redshift, with only the oldest and/or the dustiest deviating towards the green valley and red sequence. Morphologically, 69 per cent of LBGs are disc-like galaxies, with the fractions of interacting, compact, or irregular systems being much lower, below 12 per cent. LBGs have a median effective radius of 2.5 kpc, and larger galaxies have a higher total SFR and stellar mass. Compared with their high-redshift analogues, we find evidence that LBGs at lower redshifts are larger, redder in the UV continuum, and have a major presence of older stellar populations in their SEDs. However, we do not find significant differences in the distributions of stellar mass or dust attenuation.NASA NAS5-26555NASA Office of Space Science NNX09AF08GEuropean Southern Observatory LP175.A-0839.Junta de Andalucia TIC-114, P08-TIC03531Ministerio de Economía y Competitividad AYA2011-29517-C03- 01, AYA2010-1516

    Lyman break and ultraviolet-selected galaxies at z ~ 1 - II. PACS 100μm/160μm FIR detections

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    In this work, we report the Photodetector Array Camera and Spectrometer (PACS) 100 μm/160 μm detections of a sample of 42 GALEX-selected and far-infrared (FIR)-detected Lyman break galaxies (LBGs) at z ~ 1 located in the Cosmic Evolution Survey (COSMOS) field and analyse their ultraviolet (UV) to FIR properties. The detection of these LBGs in the FIR indicates that they have a dust content high enough so that its emission can be directly detected. According to a spectral energy distribution (SED) fitting with stellar population templates to their UV-to-near-IR observed photometry, PACS-detected LBGs tend to be bigger (Reff ~ 4.1 kpc), more massive [log (M*/M⊙) ~ 10.7], dustier [Es(B - V) ~ 0.40], redder in the UV continuum (β ~ -0.60) and UV-brighter [log (LUV/L⊙) ~ 10.1] than PACSundetected LBGs. PACS-detected LBGs at z ~ 1 are mostly disc-like galaxies and are located over the green valley and red sequence of the colour-magnitude diagram of galaxies at their redshift. By using their UV and IR emission, we find that PACS-detected LBGs tend to be less dusty and have slightly higher total star formation rates (SFRs) than other PACS-detected UV-selected galaxies within the same redshift range. As a consequence of the selection effect due to the depth of the FIR observations employed, all our PACS-detected LBGs have total IR luminosities, LIR, higher than 1011 L⊙ and thus are luminous IR galaxies. However, none of the PACS-detected LBGs are in the ultra-luminous IR galaxy (ULIRG) regime, LIR =1012 L⊙, where the FIR observations are complete. The finding of ULIRGs-LBGs at higher redshifts (z ~ 3) suggests an evolution of the FIR emission of LBGs with cosmic time. In an IRX-β diagram, PACS-detected LBGs at z~1 tend to be located around the relation for local starburst similarly to other UV-selected PACS-detected galaxies at the same redshift. Consequently, the dust-correction factors obtained with theirUVcontinuum slope allowus to determine their total SFR, unlike at higher redshifts. However, the dust attenuation derived from UV to NIR SED fitting overestimates the total SFR for most of our PACS-detected LBGs in an age-dependent way: the overestimation factor is higher in younger galaxies. This is likely due to the typical degeneracy between dust attenuation and age in the SED fitting with synthetic templates and highlights the importance of the FIR measurements in the analysis of star-forming galaxies at intermediate redshifts.Generalitat Valenciana PROMETEO-2008/132NASA Office of Space Science NNX09AF08GEuropean Southern Observatory LP175.A-0839Junta de Andalucía TIC-114, P08-TIC-03531Ministerio de Economía y Competitividad AYA2011- 29517-C03-01, AYA2010-22111-C03-02, AYA2010-1516

    Addition of hyaluronic acid improves tlerance to 7% hypertonic saline solution in bronchiectasis patients.

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    Background: The excessive retention of sputum in the airways, leading to pulmonary infections, is a common consequence of bronchiectasis. Although inhalation of 7% hypertonic saline (HS) has proven an effective method to help remove the mucus, many patients are intolerant of this treatment. The addition of 0.1% hyaluronic acid to HS (HS+HA) could increase tolerance to HS in these patients. The main objective of this study was to evaluate the tolerability of HS+HA in bronchiectasis patients who are intolerant to HS. Methods: This prospective, observational, open-label study analysed the outcomes of two groups of bronchiectasis patients previously scheduled to start HS therapy. Patients were assessed for tolerance to HS by a questionnaire, spirometry and clinical evaluation. Patients who were intolerant were evaluated for tolerance to HS+HA approximately one week later. All patients were evaluated for their tolerance to HS or HS+HA 4 weeks after the start of their treatment. Patients were also assessed with quality-of-life and adherence questionnaires, and all adverse events were registered. Results: A total of 137 bronchiectasis patients were enrolled in the study (age = 63.0 ± 14.7 years; 63.5% women). Of these, 92 patients (67.1%) were tolerant and 45 patients (32.9%) were intolerant to HS. Of the 45 patients intolerant to HS, 31 patients (68.9%) were tolerant and 14 patients (31.1%) intolerant to HS+HA. Of these 31 tolerant patients, 26 (83.9%) could complete the 4-week treatment with HS+HA. Conclusions: Two-thirds of bronchiectasis patients that presented intolerance to inhaled HS alone are tolerant to inhaled HS+HA, suggesting that HA improves tolerance to HS therapy

    Metal nanoparticles-PDMS nanocomposites for tunable optical filters and sensors

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    The peculiar optical response of polydimethylsiloxane (PDMS) doped with metallic nanoparticles can be employed to develop optical sensing materials. These nanocomposites may work in an ample range of temperatures, showing good linearity and high sensitivity. Plasmon resonances of the metallic nanoparticles produce interesting effects on the optical response by affecting the effective refractive index of PDMS. The high resonant response leads to a number of different configurations of optical filters and phase devices whose resonant frequency depends on the chosen nanoparticle. Moreover, the wavelength can be tuned up by external manufacturing conditions such as nanoparticle size or fill factor, and by working parameters such as temperature. This work develops the theoretical background required for the design of these structures, and evaluates the adequate dimensional and doping ranges for device optimization.This work was supported by Spanish Government RETOS Program grant no. TEC2013-47342-C2-R and no. TEC2013-50138-EXP, the R&D Program SINFOTON S2013/MIT-2790 of the Comunidad de Madrid, and the European COST Action IC1208

    Pathogen sensing device based on 2D MoS2/graphene heterostructure

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    In this work we propose a new methodology for selective and sensitive pathogen detection based on a 2D layered heterostructured biosensing platform. As a proof of concept, we have chosen SARS-CoV-2 virus because the availability of new methods to detect this virus is still a great deal of interest. The prepared platform is based on the covalent immobilization of molybdenum disulphide functionalized with a diazonium salt (f-MoS2) onto graphene screen-printed electrodes (GPH SPE) by electrografting of the diazonium salt. This chemistry-based method generates an improved heterostructured biosensing platform for aptamer immobilization and aptasensor development. Electrochemical impedance spectroscopy (EIS) is used to obtain the signal response of the device, proving the ability of the sensor platform to detect the virus. SARS-CoV-2 spike RBD recombinant protein (SARS-CoV-2 S1 protein) has been detected and quantified with a low detection limit of 2.10 fg/mL. The selectivity of the developed biosensor has been confirmed after detecting the S1 protein even in presence of other interfering proteins. Moreover, the ability of the device to detect SARS-CoV-2 S1 protein has been also tested in nasopharyngeal swab samplesThis work has been financially supported by the Spanish Ministry of Economy and Competitiveness (PID2020-116728RB-I00, PID2020- 116661RB-I00, CTQ2015-71955-REDT (ELECTROBIONET)) and Community of Madrid (TRANSNANOAVANSENS, S2018/NMT-4349, and PhotoArt P2018/NMT-4367). E. Enebral thank the financial support of “Nanotecnología para detección del SARS-CoV-2 y sus variantes. NANOCOV” project. IMDEA Nanociencia receives support from the “Severo Ochoa” Programme for Centres of Excellence in R&D (MINECO, Grant CEX2020-001039-S). We also thank the Spanish Ministry of Universities for supporting Laura Gutiérrez-Galvez with the Formación del Profesorado Universitario (FPU) grant (FPU19/06309

    A MoS2 platform and thionine-carbon nanodots for sensitive and selective detection of pathogens

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    This work focuses on the combination of molybdenum disulfide (MoS2) and à la carte functionalized carbon nanodots (CNDs) for the development of DNA biosensors for selective and sensitive detection of pathogens. MoS2 flakes prepared through liquid-phase exfoliation, serves as platform for thiolated DNA probe immobilization, while thionine functionalized carbon nanodots (Thi-CNDs) are used as electrochemical indicator of the hybridization event. Spectroscopic and electrochemical studies confirmed the interaction of Thi-CNDs with DNA. As an illustration of the pathogen biosensor functioning, DNA sequences from InIA gen of Listeria monocytogenes bacteria and open reading frame sequence (ORF1ab) of SARS-CoV-2 virus were detected and quantified with a detection limit of 67.0 fM and 1.01 pM, respectively. Given the paradigmatic selectivity of the DNA hybridization, this approach allows pathogen detection in the presence of other pathogens, demonstrated by the detection of Listeria monocytogenes in presence of Escherichia coli. We note that this design is in principle amenable to any pathogen for which the DNA has been sequenced, including other viruses and bacteria. As example of the application of the method in real samples it has been used to directly detect Listeria monocytogenes in cultures without any DNA Polymerase Chain Reaction (PCR) amplification processAuthors thank the financial support from the Comunidad de Madrid (NANOAVANSENS, S2013/MIT-3029, MAD2D-CM Program, S2013/ MIT-3007 and 2017-T1/BIO-5435), Ministerio de Economía, Industria y Competitividad (CTQ 2015-71955-REDT (ELECTROBIONET), CTQ2014-53334-C2-1-R. and MAT 2015-71879-P). EMP acknowledges the European Research Council (ERC-PoC-842606), MINECO (CTQ 2017- 86060-P), Comunidad de Madrid (MAD2D-CM S2013/MIT-3007). IMDEA Nanociencia acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV2016–0686). RdC acknowledges support from UAM, Banco Santander, Fundacion ´ IMDEA (convocatoria CRUE–CSIC–SANTANDER, fondo supera 2020, project with reference 10.01.03.02.41). Authors also acknowledge BAT unit of CIA

    Stellar populations of galaxies in the ALHAMBRA survey up to z1z \sim 1. II. Stellar content of quiescent galaxies within the dust-corrected stellar mass-colour and the UVJUVJ colour-colour diagrams

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    Our aim is to determine the distribution of stellar population parameters (extinction, age, metallicity, and star formation rate) of quiescent galaxies within the rest-frame stellar mass-colour and UVJUVJ colour-colour diagrams corrected for extinction up to z1z\sim1. These novel diagrams reduce the contamination in samples of quiescent galaxies owing to dust-reddened galaxies, and they provide useful constraints on stellar population parameters. We set constraints on the stellar population parameters of quiescent galaxies combining the ALHAMBRA multi-filter photo-spectra with our SED-fitting code MUFFIT, making use of composite stellar population models. The extinction obtained by MUFFIT allowed us to remove dusty star-forming (DSF) galaxies from the sample of red UVJUVJ galaxies. The distributions of stellar population parameters across these rest-frame diagrams are revealed after the dust correction and are fitted by the LOESS method to reduce uncertainty effects. Quiescent galaxy samples defined via classical UVJUVJ diagrams are typically contaminated by a 20\sim20% fraction of DSF galaxies. A significant part of the galaxies in the green valley are actually obscured star-forming galaxies (3065\sim30-65%). Consequently, the transition of galaxies from the blue cloud to the red sequence, and hence the related mechanisms for quenching, seems to be much more efficient and faster than previously reported. The rest-frame stellar mass-colour and UVJUVJ colour-colour diagrams are useful for constraining the age, metallicity, extinction, and star formation rate of quiescent galaxies by only their redshift, rest-frame colours, and/or stellar mass. Dust correction plays an important role in understanding how quiescent galaxies are distributed in these diagrams and is key to performing a pure selection of quiescent galaxies via intrinsic colours.Comment: (37 pages, 29 figures, accepted for publication in A&A

    The ALHAMBRA survey: Accurate merger fractions by PDF analysis of photometric close pairs

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    Our goal is to develop and test a novel methodology to compute accurate close pair fractions with photometric redshifts. We improve the current methodologies to estimate the merger fraction f_m from photometric redshifts by (i) using the full probability distribution functions (PDFs) of the sources in redshift space, (ii) including the variation in the luminosity of the sources with z in both the selection of the samples and in the luminosity ratio constrain, and (iii) splitting individual PDFs into red and blue spectral templates to deal robustly with colour selections. We test the performance of our new methodology with the PDFs provided by the ALHAMBRA photometric survey. The merger fractions and rates from the ALHAMBRA survey are in excellent agreement with those from spectroscopic work, both for the general population and for red and blue galaxies. With the merger rate of bright (M_B <= -20 - 1.1z) galaxies evolving as (1+z)^n, the power-law index n is larger for blue galaxies (n = 2.7 +- 0.5) than for red galaxies (n = 1.3 +- 0.4), confirming previous results. Integrating the merger rate over cosmic time, we find that the average number of mergers per galaxy since z = 1 is N_m = 0.57 +- 0.05 for red galaxies and N_m = 0.26 +- 0.02 for blue galaxies. Our new methodology exploits statistically all the available information provided by photometric redshift codes and provides accurate measurements of the merger fraction by close pairs only using photometric redshifts. Current and future photometric surveys will benefit of this new methodology.Comment: Submitted to A&A, 15 pages, 15 figures, 6 tables. Comments are welcome. Close pair systems available at https://cloud.iaa.csic.es/alhambra/catalogues/ClosePairs
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