602 research outputs found
La Red de Ciencia y TecnologÃa para la Conservación del Patrimonio Cultural como plataforma de colaboración
13 páginas, 15 referencias.-- Jornada celebrada los dÃas 24-25 de mayo de 2012, en el contexto de la VIII
Bienal de la Restauración y Gestión del Patrimonio AR&PA 2012, en Valladolid.-- Las Jornadas Técnicas Arespa-Investigación y
Empresa, han sido promovidas por la Delegación del CSIC en Castilla y León, la
Red de Ciencia y TecnologÃa para la Conservación del Patrimonio
Cultural (TechoHeritage) y la Asociación Española de Empresas de
Restauración del Patrimonio Histórico (Arespa).El carácter multidisciplinar de la investigación en conservación del
patrimonio cultural hace especialmente adecuado y necesario el
establecimiento de redes que pongan en contacto y permitan la
colaboración de los distintos actores implicados: universidades, centros
de investigación, instituciones culturales y empresas. Con este fin, se
creó en 2011 la Red TechnoHeritage (Red de Ciencia y TecnologÃa
para la Conservación del Patrimonio Cultural), con la financiación del
Ministerio de EconomÃa y Competitividad. TechnoHeritage aglutina en la actualidad a 80 grupos de los ámbitos
citados. En la presente publicación se presentan los orÃgenes de la Red,
las motivaciones para su puesta en marcha, los objetivos que se
pretenden alcanzar y algunas de las actividades que se han llevado a
cabo.Al Ministerio de EconomÃa y Competitividad por la financiación de la
Red dentro del Programa de Acciones Complementarias del Plan
Nacional de I+D+i 2008-2011 (HAR2010-11432-E).Peer reviewe
Electroexcitation of the Roper resonance from CLAS data
The helicity amplitudes of the electroexcitation of the Roper resonance on
proton are extracted at 1.7 < Q2 < 4.2 GeV2 from recent high precision
JLab-CLAS cross sections data and longitudinally polarized beam asymmetry for
pi+ electroproduction on protons. The analysis is made using two approaches,
dispersion relations and unitary isobar model, which give consistent results.
It is found that the transverse helicity amplitude for the gamma* p -->
P11(1440) transition, which is large and negative at Q2=0, becomes large and
positive at Q2 ~ 2 GeV2, and then drops slowly with Q2. Longitudinal helicity
amplitude, that was previously found from CLAS data as large and positive at
Q2=0.4,0.65 GeV2, drops with Q2. These results rule out the presentation of
P11(1440) as a 3qG hybrid state, and provide strong evidence in favor of this
resonance as a first radial excitation of the 3q ground state.Comment: 3 pages, 2 figures, Talk on the Workshop on "The Physics of Excited
Nucleons", Bonn, Germany, October 200
Structural basis for inhibition of the histone chaperone activity of SET/TAF-Iß by cytochrome c
Chromatin is pivotal for regulation of the DNA damage process insofar as it influences access to DNA and serves as a DNA repair docking site. Recent works identify histone chaperones as key re- gulators of damaged chromatin’s transcriptional activity. However, understanding how chaperones are modulated during DNA damage response is still challenging. This study reveals that the histone chap- erone SET/TAF-Iß interacts with cytochrome c following DNA damage. Specifically, cytochrome c is shown to be translocated into cell nuclei upon induction of DNA damage, but not upon stimulation of the death receptor or stress-induced pathways. Cytochrome c was found to competitively hinder binding of SET/TAF-Iß to core histones, thereby locking its histone-binding domains and inhibiting its nucle- osome assembly activity. In addition, we have used NMR spectros- copy, calorimetry, mutagenesis, and molecular docking to provide an insight into the structural features of the formation of the complex between cytochrome c and SET/TAF-Iß. Overall, these findings estab- lish a framework for understanding the molecular basis of cyto- chrome c-mediated blocking of SET/TAF-Iß, which subsequently may facilitate the development of new drugs to silence the oncogenic effect of SET/TAF-Iß’s histone chaperone activity
Measurement method of optical properties of ex vivo biological tissues of rats in the near-infrared range
An optical fiber-based supercontinuum setup and a custom-made spectrophotometer that can measure spectra from 1100 to 2300 nm, are used to describe attenuation properties from different ex vivo rat tissues. Our method is able to differentiate between scattering and absorption coefficients in biological tissues. Theoretical assumptions combined with experimental measurements demonstrate that, in this infrared range, tissue attenuation and absorption can be accurately measured, and scattering can be described as the difference between both magnitudes. Attenuation, absorption, and scattering spectral coefficients of heart, brain, spleen, retina, and kidney are given by applying these theoretical and experimental methods. Light through these tissues is affected by high scattering, resulting in multiple absorption events, and longer wavelengths should be used to obtain lower attenuation values. It can be observed that the absorption coefficient has a similar behavior in the samples under study, with two main zones of absorption due to the water absorption bands at 1450 and 1950 nm, and with different absolute absorption values depending on the constituents of each tissue. The scattering coefficient can be determined, showing slight differences between retina and brain samples, and among heart, spleen and kidney tissues
Semialgebraic sets and real binary forms decompositions
The Waring Problem over polynomial rings asks how to decompose a homogeneous polynomial p of degree d as a linear combination of d-th powers of linear forms. In this work we give an algorithm to obtain a real Waring decomposition of any given real binary form p of length at most its degree. In fact, we construct a semialgebraic family of Waring decompositions for p. We illustrate our results with some examples
Electrochemical characterization of organic coatings for protection of historic steel artefacts
Figuras en el archivo zipElectrochemical techniques are mainly known in the field of cultural heritage conservation as a
tool for the elimination of corrosion layers or the removal of chlorides. However, these techniques are also
a valuable tool for assessing the anti-corrosive efficiency of protective coatings. The aim of this study was
to evaluate the performance of different coatings for their use in metallic heritage conservation using
polarization resistance (Rp) and electrochemical impedance spectroscopy (EIS). Carbon steel samples were
prepared to simulate the surface composition and morphology of historic steel artefacts, and coated by a
conservator-restorer following the common practices in conservation treatments. Three commercial organic
coatings have been studied: a microcrystalline wax (RenaissanceTM) and a methyl acrylate/ethyl
methacrylate copolymer resin (ParaloidTM B-72) dissolved in acetone –both them commonly used in
conservation and restoration treatments– and a ethylene copolymer wax emulsion in water (PoligenTM ES-
91009), that has not been used so far for this purposes. Four commercial corrosion inhibitor additives were
added to the ParaloidTM B-72 resin and PoligenTM ES-91009 wax. The additives were commercial
preparations with the following known active components: a blend of triazoles (M435), an ammonium salt
of tricarboxylic acid (M370), a calcium sulphonate (M109), and a bis-oxazoline (Alkaterge-TTM). Rp and
EIS results showed that the best protection of the steel specimens was afforded by PoligenTM ES-91009
when applied in thick layers. None of the additives have shown a clear improvement of the protection
properties of the coatings, and one of them impaired the barrier effect of the coating.Acknowledgements The authors express their gratitude to the Sixth
Framework Programme of the European Commission for financial
support of PROMET Project (Contract 509126). D.M. Bastidas
expresses his gratitude to the CSIC of Spain for his contract under
the I3P Programme, co-financed by the European Social Fund.Peer reviewe
Spatially Resolved Star Formation Main Sequence of Galaxies in the Califa Survey
Cano-DÃaz, M. et. al.The >main sequence of galaxies> - defined in terms of the total star formation rate ψ versus the total stellar mass M - is a well-studied tight relation that has been observed at several wavelengths and at different redshifts. All earlier studies have derived this relation from integrated properties of galaxies. We recover the same relation from an analysis of spatially resolved properties, with integral field spectroscopic (IFS) observations of 306 galaxies from the CALIFA survey. We consider the SFR surface density in units of log(M yr Kpc) and the stellar mass surface density in units of log(M Kpc) in individual spaxels that probe spatial scales of 0.5-1.5 Kpc. This local relation exhibits a high degree of correlation with small scatter (σ = 0.23 dex), irrespective of the dominant ionization source of the host galaxy or its integrated stellar mass. We highlight (i) the integrated star formation main sequence formed by galaxies whose dominant ionization process is related to star formation, for which we find a slope of 0.81 ± 0.02; (ii) for the spatially resolved relation obtained with the spaxel analysis, we find a slope of 0.72 ± 0.04; and (iii) for the integrated main sequence, we also identified a sequence formed by galaxies that are dominated by an old stellar population, which we have called the retired galaxies sequence.Financial support: M.C.D. and S.F.S.: DGAPA-UNAM funding; CONACyT-180125 and PAPIIT IA-100815 projects. Z.S.: EU Marie Curie Career Integration Grant >SteMaGE> PCIG12-GA-2012-326466. Y.A.: RyC-2011-09461 and AYA2013-47742-C4-3-P projects from the Spanish MINECO and the SELGIFS programme, funded by the EU (FP7-PEOPLE-2013-IRSES-612701). C.J.W.: Marie Curie Career Integration Grant 303912. R.M.G.D.: AyA2014-57490-P and J.A. P12-FQM2828 grants. J.F.B.: AYA2013-48226-C3-1-P from the Spanish MINECO grant. L.G.: Millennium Science Initiative through grant IC120009, and by CONICYT through FONDECYT grant 3140566.Peer Reviewe
Ionised outflows in z 2.4 quasar host galaxies
AGN-driven outflows are invoked by galaxy evolutionary models to quench star
formation and to explain the origin of the relations observed locally between
super massive black holes and their host galaxies. This work aims to detect the
presence of extended ionised outflows in luminous quasars where we expect the
maximum activity both in star formation and in black hole accretion. Currently,
there are only a few studies based on spatially resolved observations of
outflows at high redshift, . We analyse a sample of six luminous () quasars at , observed in H-band using the
near-IR integral field spectrometer SINFONI at VLT. We perform a kinematic
analysis of the [OIII] emission line at . [OIII] has a
complex gas kinematic, with blue-shifted velocities of a few hundreds of km/s
and line widths up to 1500 km/s. Using the spectroastrometric method we infer
size of the ionised outflows of up to 2 kpc. The properties of the
ionised outflows, mass outflow rate, momentum rate and kinetic power, are
correlated with the AGN luminosity. The increase in outflow rate with
increasing AGN luminosity is consistent with the idea that a luminous AGN
pushes away the surrounding gas through fast outflows driven by radiation
pressure, which depends on the emitted luminosity. We derive mass outflow rates
of about 6-700 M/yr for our sample, which are lower than those
observed in molecular outflows. Indeed physical properties of ionised outflows
show dependences on AGN luminosity which are similar to those of molecular
outflows but indicating that the mass of ionised gas is smaller than that of
the molecular one. Alternatively, this discrepancy between ionised and
molecular outflows could be explained with different acceleration mechanisms.Comment: 13 pages, 11 figures; accepted for publication in A&
SDSS-IV MANGA: Spatially Resolved Star Formation Main Sequence and LI(N)ER Sequence
We present our study on the spatially resolved H_alpha and M_star relation
for 536 star-forming and 424 quiescent galaxies taken from the MaNGA survey. We
show that the star formation rate surface density (Sigma_SFR), derived based on
the H_alpha emissions, is strongly correlated with the M_star surface density
(Sigma_star) on kpc scales for star- forming galaxies and can be directly
connected to the global star-forming sequence. This suggests that the global
main sequence may be a consequence of a more fundamental relation on small
scales. On the other hand, our result suggests that about 20% of quiescent
galaxies in our sample still have star formation activities in the outer region
with lower SSFR than typical star-forming galaxies. Meanwhile, we also find a
tight correlation between Sigma_H_alpha and Sigma_star for LI(N)ER regions,
named the resolved "LI(N)ER" sequence, in quiescent galaxies, which is
consistent with the scenario that LI(N)ER emissions are primarily powered by
the hot, evolved stars as suggested in the literature.Comment: 6 pages, 4 figures. ApJ Letter accepte
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