2,250 research outputs found
IAA : Información y actualidad astronómica (7)
Sumario : Investigación :
Descubrir mundos en tránsito.--
Formación estelar en cúmulos.--
Ventana Abierta: Andalucía investiga.--
Charlas con...Vicente Domingo.--
Actualidad Científica: El Sol en su infancia.--
Una nueva visita cometaria.--
Actividades IAA.--
Agenda.Esta revista se publica con la ayuda de la Acción Especial DIF 2001-4284-E del Programa Nacional de Difusión de la Ciencia y la Tecnología, del Ministerio de Ciencia y Tecnología.N
Chemical Pressure Maps of Molecules and Materials: Merging the Visual and Physical in Bonding Analysis
The 2011 October Draconids outburst. I. Orbital elements, meteoroid fluxes and 21P/Giacobini-Zinner delivered mass to Earth
On October 8th, 2011 the Earth crossed the dust trails left by comet
21P/Giacobini-Zinner during its XIX and XX century perihelion approaches with
the comet being close to perihelion. The geometric circumstances of that
encounter were thus favorable to produce a meteor storm, but the trails were
much older than in the 1933 and 1946 historical encounters. As a consequence
the 2011 October Draconid display exhibited several activity peaks with
Zenithal Hourly Rates of about 400 meteors per hour. In fact, if the display
had been not forecasted, it could have passed almost unnoticed as was strongly
attenuated for visual observers due to the Moon. This suggests that most meteor
storms of a similar nature could have passed historically unnoticed under
unfavorable weather and Moon observing conditions. The possibility of obtaining
information on the physical properties of cometary meteoroids penetrating the
atmosphere under low-geocentric velocity encounter circumstances motivated us
to set up a special observing campaign. Added to the Spanish Fireball Network
wide-field all-sky and CCD video monitoring, other high-sensitivity 1/2" black
and white CCD video cameras were attached to modified medium-field lenses for
obtaining high resolution orbital information. The trajectory, radiant, and
orbital data of 16 October Draconid meteors observed at multiple stations are
presented. The results show that the meteors appeared from a geocentric radiant
located at R.A.=263.0+-0.4 deg. and Dec.=+55.3+-0.3 deg. that is in close
agreement with the radiant predicted for the 1873-1894 and the 1900 dust
trails. The estimated mass of material from 21P/Giacobini-Zinner delivered to
Earth during the six-hours outburst was around 950+-150 kg.Comment: Manuscript in press in Monthly Notices of the Royal Astronomical
Society, submitted to MNRAS on November 16th, 2012 Accepted for publication
in MNRAS on April 28th, 2013 Manuscript Pages: 21 Tables: 8 Figures: 4
Manuscript associated: "The 2011 October Draconids outburst. II. Meteoroid
chemical abundances from fireball spectroscopy" by J.M. Madiedo is also in
press in the same journa
Tuning the Cytotoxicity of Bis-Phosphino-Amines Ruthenium(II) Para-Cymene Complexes for Clinical Development in Breast Cancer
Despite some limitations such as long-term side effects or the potential presence of intrinsic
or acquired resistance, platinum compounds are key therapeutic components for the treatment of
several solid tumors. To overcome these limitations, maintaining the same efficacy, organometallic
ruthenium(II) compounds have been proposed as a viable alternative to platinum agents as they
have a more favorable toxicity profile and represent an ideal template for both, high-throughput
and rational drug design. To support the preclinical development of bis-phoshino-amine ruthenium
compounds in the treatment of breast cancer, we carried out chemical modifications in the structure
of these derivatives with the aim of designing less toxic and more efficient therapeutic agents. We
report new bis-phoshino-amine ligands and the synthesis of their ruthenium counterparts. The
novel ligands and compounds were fully characterized, water stability analyzed, and their in vitro
cytotoxicity against a panel of tumor cell lines representative of different breast cancer subtypes
was evaluated. The mechanism of action of the lead compound of the series was explored. In vivo
toxicity was also assessed. The results obtained in this article might pave the way for the clinical
development of these compounds in breast cancer therapyMinisterio de Ciencia e Innovación y Agencia Estatal de la Investigación, Spain (Grant Nos. PID2020-117788RB-I00, PID2020-
113661GB-I00, CTQ2017-84131-R and RED2018-102387-T Programa Redes Consolider), and Instituto
de Salud Carlos III grant number PI16/01121. Alberto Ocaña’s lab is supported by the Instituto
de Salud Carlos III (ISCIII, PI19/00808); CRIS Cancer Foundation, ACEPAIN, and Diputación de
Albacete
IAA : Información y actualidad astronómica (9)
Sumario : Investigación:
Las colas de polvo de los cometas.--
Agua en el Universo.--
Ventana Abierta:
Sobre la enseñanza de la ciencia en la educación
secundaria.--
Charlas con… Max Pettini.--
Actualidad Científica:
La luz y los colores de las nebulosas planetarias.--
Magnetares.--
Actividades IAA.--
Agenda.Esta revista se publica con la ayuda de la Acción Especial DIF 2001-4284-E del Programa Nacional de Difusión de la Ciencia y la Tecnología, del Ministerio de Ciencia y Tecnología.Peer reviewe
Galaxy classification: deep learning on the OTELO and COSMOS databases
Context. The accurate classification of hundreds of thousands of galaxies
observed in modern deep surveys is imperative if we want to understand the
universe and its evolution. Aims. Here, we report the use of machine learning
techniques to classify early- and late-type galaxies in the OTELO and COSMOS
databases using optical and infrared photometry and available shape parameters:
either the Sersic index or the concentration index. Methods. We used three
classification methods for the OTELO database: 1) u-r color separation , 2)
linear discriminant analysis using u-r and a shape parameter classification,
and 3) a deep neural network using the r magnitude, several colors, and a shape
parameter. We analyzed the performance of each method by sample bootstrapping
and tested the performance of our neural network architecture using COSMOS
data. Results. The accuracy achieved by the deep neural network is greater than
that of the other classification methods, and it can also operate with missing
data. Our neural network architecture is able to classify both OTELO and COSMOS
datasets regardless of small differences in the photometric bands used in each
catalog. Conclusions. In this study we show that the use of deep neural
networks is a robust method to mine the cataloged dataComment: 20 pages, 10 tables, 14 figures, Astronomy and Astrophysics (in
press
Cross‐sectional study about impact of parental smoking on rhinitis symptoms in children
[Abstract]
Objective. Assess the prevalence of rhinitis and exposure to environmental tobacco smoke (ETS) of children in our community and its relationship with symptoms of rhinitis
Methods (design, setting, participants, main outcome measures). Cross‐sectional study using questionnaire on rhinitis of the International Study of Asthma and Allergies in Childhood, in children (6‐7 years) and adolescents (13‐14 years). Categories: “rhinitis ever”, “recent rhinitis”, “recent rhinoconjunctivitis”, “severe rhinoconjunctivitis”. Parental smoking: (i) neither parent smokes; (ii) only the mother smokes; (iii) only the father smokes; and (iv) both parents smoke. Odds ratio of the prevalence of symptoms of rhinitis according to ETS exposure was calculated using logistic regression.
Results. 10 690 children and 10 730 adolescents. The prevalence of “rhinitis ever” in children: 29.4%, “recent rhinitis” 24%, “recent rhinoconjunctivitis” 11.5% and “severe rhinoconjunctivitis” 0.1%. In adolescents: 46.2%, 34.5%, 16.2% and 0.2%, respectively. Environmental tobacco smoke exposure in the home occurred in 51% of cases. Parental smoking was associated with a higher prevalence of forms of rhinitis in adolescents when only the mother was a smoker. In children when both parents were smokers.
Conclusion. Rhinitis is highly prevalent in our community. Environmental tobacco smoke exposure is still very common. The relationship between ETS and rhinitis symptoms in children of this community is not as robust as that found for asthma
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
Plan piloto desarrollo de un programa de mentoría en el programa de doctorado “Formación en la Sociedad del Conocimiento” y creación de un espacio de trabajo colaborativo online
Memoria ID-027 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2020-2021
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