ABSTRACT The "main sequence of galaxies"-defined in terms of the total star formation rate 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−1 Kpc−2) and the stellar mass surface density in units of log(M Kpc−2) 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 ( = 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.
Inflammatory bowel disease (IBD), comprising Crohn's disease (CD) and ulcerative colitis (UC), is a heterogeneous state of chronic intestinal inflammation with no exact known cause. Intestinal innate ...immunity is enacted by neutrophils, monocytes, macrophages, and dendritic cells (DCs), and innate lymphoid cells and NK cells, characterized by their capacity to produce a rapid and nonspecific reaction as a first-line response. Innate immune cells (IIC) defend against pathogens and excessive entry of intestinal microorganisms, while preserving immune tolerance to resident intestinal microbiota. Changes to this equilibrium are linked to intestinal inflammation in the gut and IBD. IICs mediate host defense responses, inflammation, and tissue healing by producing cytokines and chemokines, activating the complement cascade and phagocytosis, or presenting antigens to activate the adaptive immune response. IICs exert important functions that promote or ameliorate the cellular and molecular mechanisms that underlie and sustain IBD. A comprehensive understanding of the mechanisms underlying these clinical manifestations will be important for developing therapies targeting the innate immune system in IBD patients. This review examines the complex roles of and interactions among IICs, and their interactions with other immune and non-immune cells in homeostasis and pathological conditions.
OBJECTIVE: XXXto assess the effect on cognition of a controlled intervention testing Mediterranean diets (MedDiet). DESIGN: XXXrandomized trial after 6.5 years of nutritional intervention. SETTING: ...Eight primary care centers affiliated to the University of Navarra. PARTICIPANTS: A random subsample of 285 participants (95 randomly allocated to each of 3 groups) of the PREDIMED-NAVARRA trial. All of them were at high vascular risk (44.8% men, 74.1± 5.7 years at cognitive evaluation). INTERVENTIONS: Nutritional intervention comparing two MedDiets (supplemented with extra-virgin olive oil EVOO or mixed nuts) versus a low-fat control diet. Participants received intensive education to increase adherence to the intended intervention. Participants allocated to the MedDiet groups received EVOO (1 l/week) or 30 g/day of mixed nuts. Dietary habits were evaluated using a validated 137-item food frequency questionnaire (FFQ). Additionally, adherence to MedDiet was appraised using a 14-item questionnaire both at baseline and yearly thereafter. MEASUREMENTS: XXXcognitive performance as a main outcome and cognitive status (normal, mild cognitive impairment MCI or dementia) as a secondary outcome were evaluated by two neurologists blinded to group assignment after 6.5 years of nutritional intervention. RESULTS: Better post-trial cognitive performance versus control in all cognitive domains and significantly better performance across fluency and memory tasks were observed for participants allocated to the MedDiet+EVOO group. After adjustment for sex, age, education, apolipoprotein E genotype, family history of cognitive impairment/dementia, smoking, physical activity, body mass index, hypertension, dyslipidaemia, diabetes, alcohol and total energy intake, this group also showed lower MCI (OR=0.34 95% CI: 0.12–0.97) compared with control group. Participants assigned to MedDiet+Nuts group did not differ from controls. CONCLUSION: A long-term intervention with an EVOO-rich MedDiet resulted in a better cognitive function in comparison with a control diet. However, non-significant differences were found for most cognitive domains. Participants allocated to an EVOO-rich MedDiet had less MCI than controls.
Abstract
We study a sample of 28 S0 galaxies extracted from the integral field spectroscopic (IFS) survey Calar Alto Legacy Integral Field Area. We combine an accurate two-dimensional (2D) ...multicomponent photometric decomposition with the IFS kinematic properties of their bulges to understand their formation scenario. Our final sample is representative of S0s with high stellar masses (M⋆/M⊙ > 1010). They lay mainly on the red sequence and live in relatively isolated environments similar to that of the field and loose groups. We use our 2D photometric decomposition to define the size and photometric properties of the bulges, as well as their location within the galaxies. We perform mock spectroscopic simulations mimicking our observed galaxies to quantify the impact of the underlying disc on our bulge kinematic measurements (λ and v/σ). We compare our bulge corrected kinematic measurements with the results from Schwarzschild dynamical modelling. The good agreement confirms the robustness of our results and allows us to use bulge deprojected values of λ and v/σ. We find that the photometric (n and B/T) and kinematic (v/σ and λ) properties of our field S0 bulges are not correlated. We demonstrate that this morpho-kinematic decoupling is intrinsic to the bulges and it is not due to projection effects. We conclude that photometric diagnostics to separate different types of bulges (disc-like versus classical) might not be useful for S0 galaxies. The morpho-kinematics properties of S0 bulges derived in this paper suggest that they are mainly formed by dissipational processes happening at high redshift, but dedicated high-resolution simulations are necessary to better identify their origin.
We investigate the cosmic evolution of the absolute and specific star formation rate (SFR, sSFR) of galaxies as derived from a spatially resolved study of the stellar populations in a set of 366 ...nearby galaxies from the Calar Alto Legacy Integral Field Area (CALIFA) survey. The sample spans stellar masses from M⋆ ~ 109 to 1012M⊙ and a wide range of Hubble types. The analysis combines images obtained with the Galaxy Evolution Explorer (GALEX; far-ultraviolet and near-ultraviolet) and Sloan Digital Sky Survey (SDSS; u, g, r, i, z) with the 4000 Å break, Hβ, and MgFe′ indices measured from the CALIFA data cubes to constrain parametric models for the star formation history (SFH), which are then used to study the cosmic evolution of the SFR density (ρSFR), the sSFR, the main sequence of star formation (MSSF), and the stellar mass density (ρ⋆). Several SFH laws are used to fit the observational constrains. A delayed-τ model, SFR ∝ (t0 − t)exp(−(t0 − t)∕τ), provides the best results, in good agreement with those obtained from cosmological surveys. Our main results from this model are that (a) the mass currently in the inner (≤0.5 half-light radius, HLR) regions formed at earlier epochs than the mass in the outer (1–2 HLR) regions of galaxies. The time since the onset of the star formation is longer in the inner regions (t0 ~ 13−10 Gyr) than in the outer ones (t0 ~ 11−9 Gyr) for all the morphologies, while the e-folding timescale τ in the inner region is similar to or shorter than in the outer regions. These results confirm that galaxies of any Hubble type grow inside-out. (b) The sSFR declines rapidly as the Universe evolves, and faster for early- than for late-type galaxies, and for the inner than for the outer regions of galaxies. (c) The evolution of ρSFR and ρ⋆ agrees well with results from cosmological surveys, particularly with the recent results from the Galaxy And Mass Assembly (GAMA), the G10-Cosmological Evolution Survey (COSMOS), and the 3D Hubble Space Telescope (HST) survey. At low redshift, z ≤ 0.5, most star formation takes place in the outer regions of late spiral galaxies, while at z > 2, the inner regions of the progenitors of the current E and S0 are the main contributors to ρSFR. (d) Similarly, the inner regions of galaxies are the main contributor to ρ⋆ at z > 0.5, growing their mass faster than the outer regions, with a lookback time at 50% ρ⋆ of t50 ~ 9 and 6 Gyr for the inner and outer regions. (e) The MSSF follows a power law at high redshift, with the slope evolving with time but always remaining sub-linear, in good agreement with the Illustris simulation. (f) In agreement with galaxy surveys at different redshifts, the average SFH of CALIFA galaxies indicates that galaxies grow their mass mainly in a mode that is well represented by a delayed-τ model, with the peak at z ~ 2 and an e-folding time of ~3.9 Gyr.
The highly packed cetyltrimethylammonium bromide (CTAB) bilayer built up on the surface of gold nanorods (AuNRs) when synthesized by the seed-mediated procedure hampers the complete ligand exchange ...under experimental conditions that preserves the stability of the dispersions. In the present work, a ligand exchange protocol by using carboxy-terminated alkanethiols of different chain lengths by means of a green approach that uses only aqueous solutions is presented. The protocol is based on the knowledge of the stability in the aqueous solution of both the starting CTAB-AuNRs and the final products that help in the choice of the experimental conditions used for ligand exchange. The characterization of the CTAB protective layer as well as the study of its colloidal stability in solution has helped us to design an appropriate methodology. Cyclic voltammetry of CTAB-AuNRs demonstrates the high stability of the bilayer showing the existence of a two-dimensional phase transition from a highly ordered to a less organized phase. Other techniques such as XPS, FT-IR and Raman spectroscopy provide information about the structure of the layer and UV-visible-NIR spectroscopy establishes the stability conditions in aqueous solution. We have chosen an exchange procedure for 11-mercaptoundecanoic acid (MUA) and 16-mercaptohexadecanoic acid (MHDA) based on a one-pot methodology under conditions where all the species involved are stable. The protocol, however, can be extended to different chemical functionalities that are considered useful to be applied in living systems. Under these conditions the complete exchange of CTAB by the mercaptoderivatives was successful as demonstrated by the different characterization techniques used: UV-visible-NIR, FT-IR, Raman, XPS spectroscopy, cyclic voltammetry and transmission electron microscopy (TEM).
The highly packed cetyltrimethylammonium bromide bilayer on the surface of gold nanorods synthesized by the seed-mediated procedure hampers the complete ligand exchange under experimental conditions that preserves the stability of the dispersions.
Abstract
We use spatially resolved spectroscopy from the Calar Alto Legacy Integral Field Area (CALIFA) survey to study the nature of the line emitting gas in galaxies of different Hubble types, ...focusing on the separation of star-forming (SF) regions from those better characterized as diffuse ionized gas (DIG). The diagnosis is carried out in terms of the equivalent width of H α (WH α). Three nebular regimes are identified. Regions where WH α < 3 Å define what we call the hDIG, the component of the DIG where photoionization is dominated by hot, low-mass, evolved stars. Regions where WH α > 14 Å trace SF complexes. WH α values in the intermediate 3–14 Å range reflect a mixed regime (mDIG) where more than one process contributes. This three-tier scheme is inspired both by theoretical and empirical considerations. Its application to CALIFA galaxies of different types and inclinations leads to the following results: (i) the hDIG component is prevalent throughout ellipticals and S0’s as well as in bulges, and explains the strongly bimodal distribution of WH α both among and within galaxies. (ii) Early-type spirals have some hDIG in their discs, but this component becomes progressively less relevant for later Hubble types. (iii) hDIG emission is also present above and below galactic discs, as seen in several edge-on spirals in our sample. (iv) The SF/mDIG proportion grows steadily from early- to late-type spirals, and from inner to outer radii. (v) Besides circumventing basic inconsistencies in conventional DIG/SF separation criteria based on the H α surface brightness, our WH α-based method produces results in agreement with a classical excitation diagram analysis.
Various different physical processes contribute to the star formation and stellar mass assembly histories of galaxies. One important approach to understanding the significance of these different ...processes on galaxy evolution is the study of the stellar population content of today's galaxies in a spatially resolved manner. The aim of this paper is to characterize in detail the radial structure of stellar population properties of galaxies in the nearby universe, based on a uniquely large galaxy sample, considering the quality and coverage of the data. The sample under study was drawn from the CALIFA survey and contains 300 galaxies observed with integral field spectroscopy. To study mean trends with overall galaxy properties, the individual radial profiles are stacked in seven bins of galaxy morphology (E, SO,Sa, Sb, Sbc, Sc, and Sd). The galaxies from the sample have decreasing-outward stellar extinction; all spirals show similar radial profiles, independent from the stellar mass, but redder than E and SO. Overall, we conclude that quenching processes act in manners that are independent of mass, while metallicity and galaxy structure are influenced by mass-dependent processes.
For a bio-economy establishment, understanding the energy consumption needs to produce solid biofuels is a key point. Herein, olive tree pruning was treated by both dry (pyrolysis and torrefaction) ...and wet (hydrothermal carbonization) thermal treatments. Product yield, solid quality and energy consumption were assessed. The solids were characterized by means of chemical and thermogravimetric analysis. For all treatments, coal-like solid products were obtained, with higher heating values (HHV) of almost 30 MJ kg−1 in most of the conditions evaluated. Chars from pyrolysis presented the greater carbon content (between 76 and 85 wt%) but also the higher ash content (ranging from 6 to 9 wt%). From an energy consumption perspective, torrefaction registered the lowest energy consumption (between 5.85 and 20.76 MJ kg−1 char). The highest energy contents per kilogram of char produced were also reflected in torrefaction samples, with values around 11 MJ kg−1 char. Although the obtained HHVs were greater for pyrolysis chars the higher mass yields obtained in torrefaction makes it more profitable. The least severe conditions allowed to obtain a positive energy balance only with the solid phase considered. Nonetheless, further room for improvement is possible since the gas and liquid phases may also be valorised.
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•Pyrolysis, torrefaction and HTC were assessed regarding yield, quality and energy consumption.•From both wet and dry treatments, products with HHV of ca. 30 MJ kg−1 were obtained.•Pyrolysis concentrates the carbon content in the char to a greater extent (80 wt%).•The highest energy content per kg of char were reflected in torrefaction samples.•Torrefaction registered the lowest energy consumption from ca. 5–20 MJ kg−1 char.
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