1,137 research outputs found
The CO-to-H2 conversion factor of molecular outflows. Rovibrational CO emission in NGC 3256-S resolved by JWST/NIRSpec
We analyze JWST/NIRSpec observations of the CO rovibrational v=1-0 band at
~4.67um around the dust-embedded southern active galactic nucleus (AGN) of
NGC3256 (d=40Mpc; L(IR)=10^11.6 Lsun). We classify the CO v=1-0 spectra into
three categories based on the behavior of P- and R-branches of the band: (a)
both branches in absorption toward the nucleus; (b) P-R asymmetry (P-branch in
emission and R-branch in absorption) along the disk of the galaxy; and (c) both
branches in emission in the outflow region above and below the disk. In this
paper, we focus on the outflow. The CO v=1-0 emission can be explained by the
vibrational excitation of CO in the molecular outflow by the bright mid-IR
~4.7um continuum from the AGN up to r~250pc. We model the ratios between the
P(J+2) and R(J) transitions of the band to derive the physical properties
(column density, kinetic temperature, and CO-to-H2 conversion factor, alpha_CO)
of the outflowing gas. We find that the 12CO v=1-0 emission is optically thick
for J<4, while the 13CO v=1-0 emission remains optically thin. From the
P(2)/R(0) ratio, we identify a temperature gradient in the outflow from >40K in
the central 100pc to <15K at 250pc sampling the cooling of the molecular gas in
the outflow. We used three methods to derive alpha_CO in eight 100pc (0.5")
apertures in the outflow by fitting the P(J+2)/R(J) ratios with non-LTE models.
We obtain low alpha_CO x 3.2e-4/[CO/H2] factors between 0.34 and 0.62 Msun (K
km/s/pc2)^-1. This implies that outflow rates and energetics might be
overestimated if a ULIRG-like alpha_CO, which is 1.3-2.4 times larger, is
assumed.
We also report the first extragalactic detection of a broad
(sigma=590km/s=0.0091um) spectral feature at 4.645um associated with aliphatic
deuterium on polycyclic aromatic hydrocarbons (D_n-PAH).Comment: 17 pages, 12 figures. Submitted to A&
Evidence for a chemically differentiated outflow in Mrk 231
Aims: Our goal is to study the chemical composition of the outflows of active
galactic nuclei and starburst galaxies.
Methods: We obtained high-resolution interferometric observations of HCN and
HCO and of the ultraluminous infrared
galaxy Mrk~231 with the IRAM Plateau de Bure Interferometer. We also use
previously published observations of HCN and HCO and
, and HNC in the same source.
Results: In the line wings of the HCN, HCO, and HNC emission, we find
that these three molecular species exhibit features at distinct velocities
which differ between the species. The features are not consistent with emission
lines of other molecular species. Through radiative transfer modelling of the
HCN and HCO outflow emission we find an average abundance ratio
. Assuming a clumpy outflow,
modelling of the HCN and HCO emission produces strongly inconsistent
outflow masses.
Conclusions: Both the anti-correlated outflow features of HCN and HCO and
the different outflow masses calculated from the radiative transfer models of
the HCN and HCO emission suggest that the outflow is chemically
differentiated. The separation between HCN and HCO could be an indicator of
shock fronts present in the outflow, since the HCN/HCO ratio is expected to
be elevated in shocked regions. Our result shows that studies of the chemistry
in large-scale galactic outflows can be used to better understand the physical
properties of these outflows and their effects on the interstellar medium (ISM)
in the galaxy.Comment: 12 pages, 8 figures, accepted for publication in A&
Potential impacts of climate variability on Dengue Hemorrhagic Fever in Honduras, 2010
Climate change and variability are affecting human health and disease direct or indirectly through many mechanisms. Dengue is one of those diseases that is strongly influenced by climate variability; however its study in Central America has been poorly approached. In this study, we assessed potential associations between macroclimatic and microclimatic variation and dengue hemorrhagic fever (DHF) cases in the main
hospital of Honduras during 2010. In this year, 3,353 cases of DHF were reported in the
Hospital Escuela, Tegucigalpa. Climatic periods marked a difference of 158% in the mean incidence of cases, from El Niño weeks (-99% of cases below the mean incidence) to La Niña months (+59% of cases above it) (p<0.01). Linear regression showed significantly higher dengue incidence with lower values of Oceanic Niño Index (p=0.0097), higher rain probability (p=0.0149), accumulated rain (p=0.0443) and higher relative humidity (p=0.0292). At a multiple linear regression model using those variables, ONI values shown to be the most important and significant factor found to be associated with the monthly occurrence of DHF cases (r2=0.649; βstandardized=–0.836; p=0.01). As has been shown herein, climate variability is an important element influencing the dengue epidemiology in
Honduras. However, it is necessary to extend these studies in this and other countries in
the Central America region, because these models can be applied for surveillance as
well as for prediction of dengue
Design of in-building wireless networks deployments using evolutionary algorithms
In this article, a novel approach to deal with the design of in-building wireless networks deployments is proposed. This approach known as MOQZEA (Multiobjective Quality Zone Based Evolutionary Algorithm) is a hybr id evolutionary algorithm adapted to use a novel fitness function, based on the definition of quality zones for the different objective functions considered. This approach is conceived to solve wireless network design problems without previous information of the required number of transmitters, considering simultaneously a high number of objective functions and optimizing multiple configuration parameters of the transmitters
A Gravitational Wave Background from Reheating after Hybrid Inflation
The reheating of the universe after hybrid inflation proceeds through the
nucleation and subsequent collision of large concentrations of energy density
in the form of bubble-like structures moving at relativistic speeds. This
generates a significant fraction of energy in the form of a stochastic
background of gravitational waves, whose time evolution is determined by the
successive stages of reheating: First, tachyonic preheating makes the amplitude
of gravity waves grow exponentially fast. Second, bubble collisions add a new
burst of gravitational radiation. Third, turbulent motions finally sets the end
of gravitational waves production. From then on, these waves propagate
unimpeded to us. We find that the fraction of energy density today in these
primordial gravitational waves could be significant for GUT-scale models of
inflation, although well beyond the frequency range sensitivity of
gravitational wave observatories like LIGO, LISA or BBO. However, low-scale
models could still produce a detectable signal at frequencies accessible to BBO
or DECIGO. For comparison, we have also computed the analogous gravitational
wave background from some chaotic inflation models and obtained results similar
to those found by other groups. The discovery of such a background would open a
new observational window into the very early universe, where the details of the
process of reheating, i.e. the Big Bang, could be explored. Moreover, it could
also serve in the future as a new experimental tool for testing the
Inflationary Paradigm.Comment: 22 pages, 18 figures, uses revtex
Synthesis and characterization of perovskite FAPbBr(3-x) I (x) thin films for solar cells
[EN] FAPbI3, FAPbBr3, and FAPbBr3-xIx perovskite thin films were produced in a single step from a solution containing a mixture of FAI, PbI2, FABr, and PbBr2 (FA = formamidinium). FAPbBr3-xIx perovskite thin films were deposited onto ITO-coated glass substrates by spin coating. X-ray diffraction analyses confirmed that these thin-film perovskites crystallize in the cubic phase (Pm-3 m) for all composition range 0 B x B 3. Mixed lead perovskites showed a high absorbance in the UV¿Vis range. The optical band gap was estimated from spectral absorbance measurements. It was found that the onset of the absorption edge for FAPbBr3¿xIx thin films ranges between 1.47 and 2.20 eV for x = 0 and x = 3, respectively. Photoluminescence emission energies for mixed halide perovskites were also dependent on their composition and presented intermediate values from 810.4 nm for FAPbI3 to 547.3 nm for FAPbBr3.This work was supported by Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat valenciana (Prometeus 2014/044).Slimi, B.; Mollar GarcÃa, MA.; Ben Assaker, I.; Kriaa, A.; Chtourou, R.; MarÃ, B. (2017). Synthesis and characterization of perovskite FAPbBr(3-x) I (x) thin films for solar cells. Monatshefte für Chemie - Chemical Monthly. 148(5):835-844. https://doi.org/10.1007/s00706-017-1958-0S835844148
Terapias complementarias en cirugÃa podológica
Este artÃculo presenta una serie de terapias complementarias, como son la homeopatÃa, la fitoterapia y la oligoterapia, en relación con la cirugÃa del pie. Éstas terapias nos serán de gran ayuda como coadyuvantes en las terapias prequirúrgicas y posquirúrgicas, asà como en el mismo transcurso de la cirugÃa
Spin-label EPR study in thylakoid membranes from a new herbicide-resistant D1 mutant from soybean cell cultures deficient in fatty acid desaturation
El pdf del artÃculo es la versión post-print.Fatty acid desaturation effect on the lipid fluidity in thylakoid membranes isolated from the STR7 mutant was investigated by electron paramagnetic resonance (EPR) using spin label probes. The spectra of both 5- and 16-n-doxylstearic acid probes were measured as a function of the temperature between 10-305 K and compared to those of the wild type. This complete thermal evolution provides a wider picture of the dynamics. The spectra of the 5-n-doxylstearic acid probe were identical in both STR7 mutant and wild type thylakoids as well as their temperature evolution. However, differences were found with the 16-n-doxylstearic acid probe at temperatures between 230-305 K. The differences in the thermal evolution of the EPR spectra can be interpreted as a 5-10 K shift toward higher temperatures of the probe motional rates in the STR7 mutant as compared with that in the wild type. At temperatures below 230 K no differences were observed. The results indicated that the lipid motion in the outermost region of the thylakoids is the same in the STR7 mutant than in the wild type while the fluidity in the inner region of the STR7 mutant membrane decreases. Our data point out a picture of the STR7 thylakoid membrane in which the lipid motion is slower most probably as a consequence of fatty acid desaturation deficiency.M.A. and I.G.-R. were recipients of a contract and a fellowship, respectively, from the Ministerio de Educación y Cultura of Spain. This work was supported by the Dirección General de Investigación CientÃfica y Técnica (Grant PB98-1632) and by the Diputación General de Aragón (Project P17/98).Peer reviewe
Characterization of goat colostrum oligosaccharides by nano-liquid chromatography on chip quadrupole time-of-flight mass spectrometry and hydrophilic interaction liquid chromatography-quadrupole mass spectrometry
A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography–quadrupole-time of flight mass spectrometry (Nano-LC-Chip–Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or Nglycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2–0.6 min) and good symmetry (As: 0.8–1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40 â—¦C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315 mg L−1 for neutral oligosaccharides and from 83 to 251 mg L−1 for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO.This work has been funded by Junta de AndalucÃa (project AGR2011-7626), CSIC (project i-link0827), Comunidad Autónoma de Madrid (Spain) and European funding from FEDER program (AVANSECAL-CM S2013/ABI-3028) and Fundación Ramón Areces. This work was also supported by the UC Davis RISE program and the National Institutes of Health awards R21AT006180, R01AT007079, R01AT008759-02.Peer reviewe
Bevacizumab plus mFOLFOX-6 or FOLFOXIRI in patients with initially unresectable liver metastases from colorectal cancer: the OLIVIA multinational randomised phase II trial
OLIVIA, a multinational phase II study, suggests that bevacizumab plus FOLFOXIRI improves outcomes, including response rates, resection rates, and progression-free survival, compared with bevacizumab plus mFOLFOX-6 in patients with initially unresectable liver metastases from colorectal cance
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