284 research outputs found
A laser spectroscopy system with combined absorption, polarization rotation and fluorescence detection to study two photon transitions in atomic rubidium
AbstractThe design and construction of an experimental system for studying two photon spectroscopy processes in atomic rubidium is presented. It is designed to measure absorption and polarization rotation induced by any of the two laser beams and also the visible fluorescence that results from decay of the excited states. Two home-built diode lasers are used to produce the optical fields that later interact with room temperature rubidium atoms. Using counterpropagating beams allows velocity selection of the groups of atoms that interact with both laser beams. The system was tested in the 5 S→5 P3/2→5 Dj ladder energy level configuration of atomic rubidium. Blue fluorescence (420nm) that results from decay of the intermediate 6Pj states is filtered and then measured with a photomultiplier tube. Absorption and fluorescence spectra provide mutually complementary information about the interaction between the rubidium atoms and the two optical fields
The OTELO survey. A case study of [O III]4959,5007 emitters at <z> = 0.83
The OTELO survey is a very deep, blind exploration of a selected region of
the Extended Groth Strip and is designed for finding emission-line sources
(ELSs). The survey design, observations, data reduction, astrometry, and
photometry, as well as the correlation with ancillary data used to obtain a
final catalogue, including photo-z estimates and a preliminary selection of
ELS, were described in a previous contribution. Here, we aim to determine the
main properties and luminosity function (LF) of the [O III] ELS sample of OTELO
as a scientific demonstration of its capabilities, advantages, and
complementarity with respect to other surveys. The selection and analysis
procedures of ELS candidates obtained using tunable filter (TF) pseudo-spectra
are described. We performed simulations in the parameter space of the survey to
obtain emission-line detection probabilities. Relevant characteristics of [O
III] emitters and the LF([O III]), including the main selection biases and
uncertainties, are presented. A total of 184 sources were confirmed as [O III]
emitters at a mean redshift z=0.83. The minimum detectable line flux and
equivalent width (EW) in this ELS sample are 5 10 erg
s cm and 6 \AA, respectively. We are able to constrain the
faint-end slope () of the observed LF([O III]) at
z=0.83. This LF reaches values that are approximately ten times lower than
those from other surveys. The vast majority (84\%) of the morphologically
classified [O III] ELSs are disc-like sources, and 87\% of this sample is
comprised of galaxies with stellar masses of M 10
M.Comment: v1: 16 pages, 6 figures. Accepted in Astronomy \& Astrophysics. v2:
Author added in metadat
Generation of a novel model of bioengineered human oral mucosa with increased vascularization potential
Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+I) of the Spanish Ministry of Science and Innovation (Instituto de Salud Carlos III), Grant/Award Number: FIS PI18/331, FIS PI21/00980, FIS PI18/332 and ICI19/00024; Consejeria de Salud y Familias, Junta de Andalucia, Spain, Grant/Award Number: PI-0442--2019; FEDER funds, European UnionObjective: The aim of this study was to generate novel models of bioartificial human
oral mucosa with increased vascularization potential for future use as an advanced
therapies medicinal product, by using different vascular and mesenchymal stem cell
sources.
Background: Oral mucosa substitutes could contribute to the clinical treatment of
complex diseases affecting the oral cavity. Although several models of artificial oral
mucosa have been described, biointegration is a major issue that could be favored
by the generation of novel substitutes with increased vascularization potential once
grafted in vivo.
Methods: Three types of mesenchymal stem cells (MSCs) were obtained from adipose
tissue, bone marrow, and dental pulp, and their in vitro potential was evaluated by
inducing differentiation to the endothelial lineage using conditioning media. Then, 3D
models of human artificial oral mucosa were generated using biocompatible fibrin-agarose
biomaterials combined with human oral mucosa fibroblasts and each type
of MSC before and after induction to the endothelial lineage, using human umbilical
vein endothelial cells (HUVEC) as controls. The vascularization potential of each oral
mucosa substitute was assessed in vitro and in vivo in nude mice.
Results: In vitro induction of MSCs kept in culture was able to increase the expression
of VEGF, CD31, and vWF endothelial markers, especially in bone marrow and
dental pulp-MSCs,
and numerous proteins with a role in vasculogenesis become overexpressed.
Then, in vivo grafting resulted in a significant increase in blood vessels
formation at the interface area between the graft and the host tissues, with significantly
positive expression of VEGF, CD31, vWF, and CD34 as compared to negative
controls, especially when pre-differentiated
MSCs derived from bone marrow and
dental pulp were used. In addition, a significantly higher number of cells committed to the endothelial lineage expressing the same endothelial markers were found within
the bioartificial tissue.
Conclusion: Our results suggest that the use of pre-differentiated
MSCs could contribute
to a rapid generation of a vascular network that may favor in vivo biointegration
of bioengineered human oral mucosa substitutes.Spanish Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica (I+D+I) of the Spanish Ministry of Science and Innovation (Instituto de Salud Carlos III) FIS PI18/331
FIS PI21/00980
FIS PI18/332
ICI19/00024Junta de Andalucia PI-0442-2019European Commissio
Diseño de un instrumento de aprendizaje para la formación continua de trabajadores de PYMES
The purpouse of this article is to describe the authors’ experience adquired by developping a learning tool for SMEs’ (Small and Medium Size Enterprises) workers. The learning tool is a CDROM with several multimedia interactive courses about Internet and its services -telnet, ftp, www...- and different telecommunication services. All these courses are offered inside an enviroment named Virtual Classroom, also developped by us. The learning tool has been developped by an interdisciplinary and interuniversitary group made up by experts in different fields of knowledge. The result hasn’t only been the CDROM but a the definition of a model for future courses together with a list of advices.El propósito de este artículo es describir la experiencia adquirida por los autores en el desarrollo de un instrumento de aprendizaje para trabajadores de PYMEs (Pequeñas y Medianas Empresas). El instrumento es un CDROM que contiene diversos cursos multimedia interactivos sobre Internet y sus herramientas -transferencia de ficheros, World Wide Web...- y sobre diferentes servicios de telecomunicación. Todos los cursos se ofrecen en un entorno que también ha sido desarrollado por nosotros y que hemos denominado Aula Virtual. El grupo de trabajo es interuniversitario e interdisciplinar, estando formado por investigadores de diversos campos del saber que ejercen su labor docente en diversas universidades españolas. El resultado de este trabajo, no ha sido únicamente un CDROM, sino la definición de un modelo para la realización de futuros CDROMs por nosotros mismos o por otros grupos de trabajo, y asimismo una lista de consejos para la realización de cursos multimedia interactivos
C-Reactive Protein and Serum Albumin Ratio: A Feasible Prognostic Marker in Hospitalized Patients with COVID-19
Background: C-reactive protein (CRP) and albumin are inflammatory markers. We analyzed the prognostic capacity of serum albumin (SA) and CRP for an outcome comprising mortality, length of stay, ICU admission, and non-invasive mechanical ventilation in hospitalized COVID-19 patients. (2) Methods: We conducted a retrospective cohort study based on the Spanish national SEMI-COVID-19 Registry. Two multivariate logistic models were adjusted for SA, CRP, and their combination. Training and testing samples were used to validate the models. (3) Results: The outcome was present in 41.1% of the 3471 participants, who had lower SA (mean [SD], 3.5 [0.6] g/dL vs. 3.8 [0.5] g/dL; p < 0.001) and higher CRP (108.9 [96.5] mg/L vs. 70.6 [70.3] mg/L; p < 0.001). In the adjusted multivariate model, both were associated with poorer evolution: SA, OR 0.674 (95% CI, 0.551-0.826; p < 0.001); CRP, OR 1.002 (95% CI, 1.001-1.004; p = 0.003). The CRP/SA model had a similar predictive capacity (honest AUC, 0.8135 [0.7865-0.8405]), with a continuously increasing risk and cutoff value of 25 showing the highest predictive capacity (OR, 1.470; 95% CI, 1.188-1.819; p < 0.001). (4) Conclusions: SA and CRP are good independent predictors of patients hospitalized with COVID-19. For the CRP/SA ratio value, 25 is the cutoff for poor clinical course
The OTELO survey II. The faint-end of the Hα luminosity function at z ∼ 0.40
ABSTRACT: Aims. We take advantage of the capability of the OTELO survey to obtain the Hα luminosity function (LF) at z∼0.40. Because of the deepest coverage of OTELO, we are able to determine the faint end of the LF, and thus better constrain the star formation rate and the number of galaxies at low luminosities. The AGN contribution to this LF is estimated as well.
Methods. We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, which is unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects.
Results. The Hα luminosity function at z∼0.40 is obtained, which extends the current faint end by almost 1 dex, reaching minimal
luminosities of log10 Llim=38.5 erg s−1 (or ∼0.002 M yr−1). The AGN contribution to the total Hα luminosity is estimated. We find
that no AGN should be expected below a luminosity of log10 L=38.6 erg s−1. From the sample of non-AGN (presumably, pure SFG) at z∼0.40 we estimated a star formation rate density of ρSFR = 0.012 ± 0.005 M yr−1 Mpc−3This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2013-46724-P, AYA2014-58861-C3-1-P, AYA2014-58861-C3-2-P, AYA2014-58861-C3-3-P, AYA2016-75808-R, AYA2016-75931-C2-2-P, AYA2017-88007-C3-1-P, and AYA2017-88007-C3-2-
The OTELO survey III. Demography, morphology, IR luminosity and environment of AGN hosts
ABSTRACT: Aims. We take advantage of the capabilities of the OSIRIS Tunable Emission Line Object (OTELO) survey to select and study the AGN population in the field. In particular, we aim to perform an analysis of the properties of these objects, including their demography, morphology, and IR luminosity. Focusing on the population of Hα emitters at z∼0.4, we also aim to study the environments of AGN and non-AGN galaxies at that redshift.
methods. We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification
of emission lines and the discrimination of different types of objects.
Results. We obtained a sample of 72 AGNs in the field of OTELO, selected with four different methods in the optical, X-rays, and mid-infrared bands. We find that using X-rays is the most efficient way to select AGNs. An analysis was performed on the AGN population of OTELO in order to characterise its members. At z∼0.4, we find that up to 26% of our Hα emitters are AGNs. At that redshift, AGNs are found in identical environments to non-AGNs, although they represent the most clustered group when compared to passive and star-forming galaxies. The majority of our AGNs at any redshift were classified as late-type galaxies, including a 16% proportion of irregulars. Another 16% of AGNs show signs of interactions or mergers. Regarding the infrared luminosity, we are able to recover all the luminous infrared galaxies (LIRGs) in the field of OTELO up to z∼1.6. We find that the proportion of LIRGs and ultra-luminous infraed galaxies (ULIRGs) is higher among the AGN population, and that ULIRGs show a higher fraction of AGNs than LIRGs.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2013-46724 P, AYA2013-42227-P, AYA2014-58861-C3-1-P, AYA2014-58861-C3-2-P, AYA2014-58861-C3-3-P, AYA2016-75808-R, AYA2016-75931-C2-1-P, AYA2016-75931-C2-2-P, AYA2016-76682C3-1-P, AYA2017-88007-C3-1-P and AYA2017-88007-C3-2-P
II. The faint-end of the Hα luminosity function at z ∼ 0.40
[Aims] We take advantage of the capability of the OTELO survey to obtain the H alpha luminosity function (LF) at z similar to 0.40. Because of the deepest coverage of OTELO, we are able to determine the faint end of the LF, and thus better constrain the star formation rate and the number of galaxies at low luminosities. The AGN contribution to this LF is estimated as well.
[Methods] We make use of the multiwavelength catalogue of objects in the field compiled by the OTELO survey, which is unique in terms of minimum flux and equivalent width. We also take advantage of the pseudo-spectra built for each source, which allow the identification of emission lines and the discrimination of different types of objects.
[Results] The H alpha luminosity function at z similar to 0.40 is obtained, which extends the current faint end by almost 1 dex, reaching minimal luminosities of log(10) L-lim = 38.5 erg s(-1) (or similar to 0.002 M-circle dot yr(-1)). The AGN contribution to the total H alpha luminosity is estimated. We find that no AGN should be expected below a luminosity of log(10) L = 38.6 erg s(-1). From the sample of non-AGN (presumably, pure SFG) at z similar to 0.40 we estimated a star formation rate density of rho(SFR) = 0.012 +/- 0.005 M-circle dot yr(-1) Mpc(-3).This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) under the grants AYA2013- 46724- P, AYA2014 58861-C3-1- P, AYA2014-58861-C3-2-P, AYA2014-58861-C3-3- P, AYA2016 -75808-R, AYA2016-75931-C2-2-P, AYA2017-88007-C3-1-P, and AYA2017 -88007-C3-2- P. Based on observations made with the Gran Telescopio Canarias installed in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias, in the island of La Palma. The authors thanks the anonymous referee for her/his feedback and suggestions
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