SHARDS: Constraints on the dust attenuation law of star-forming galaxies at z~2

We make use of SHARDS, an ultra-deep (<26.5AB) galaxy survey that provides optical photo-spectra at resolution R~50, via medium band filters (FWHM~150A). This dataset is combined with ancillary optical and NIR fluxes to constrain the dust attenuation law in the rest-frame NUV region of star-forming galaxies within the redshift window 1.5<z<3. We focus on the NUV bump strength (B) and the total-to-selective extinction ratio (Rv), targeting a sample of 1,753 galaxies. By comparing the data with a set of population synthesis models coupled to a parametric dust attenuation law, we constrain Rv and B, as well as the colour excess, E(B-V). We find a correlation between Rv and B, that can be interpreted either as a result of the grain size distribution, or a variation of the dust geometry among galaxies. According to the former, small dust grains are associated with a stronger NUV bump. The latter would lead to a range of clumpiness in the distribution of dust within the interstellar medium of star-forming galaxies. The observed wide range of NUV bump strengths can lead to a systematic in the interpretation of the UV slope ($\beta$) typically used to characterize the dust content. In this study we quantify these variations, concluding that the effects are $\Delta\beta$~0.4.Comment: 13 pages, 11+2 figures, 3 tables. MNRAS, in pres

The Ubiquity of the rms-flux relation in Black Hole X-ray Binaries

We have investigated the short term linear relation between the rms variability and the flux in 1,961 observations of 9 black hole X-ray binaries. The rms-flux relation for the 1-10 Hz range is ubiquitously observed in any observation with good variability signal to noise (> 3 % 1-10 Hz fractional rms). This concurs with results from a previous study of Cygnus X-1 (Gleissner et. al. 2004), and extends detection of the rms-flux relation to a wider range of states. We find a strong dependence of the flux intercept of the rms-flux relation on source state; as the source transitions from the hard state into the hard intermediate state the intercept becomes strongly positive. We find little evidence for flux dependence of the broad-band noise within the PSD shape, excepting a small subset of observations from one object in an anomalous soft-state. We speculate that the ubiquitous linear rms-flux relation in the broad band noise of this sample, representing a range of different states and objects, indicates that its formation mechanism is an essential property of the luminous accretion flow around black holes.Comment: 12 pages, 6 figures, accepted for publication in MNRA

Suppression of ferromagnetic ordering in doped manganites: Effects of the superexchange interaction

From a Monte Carlo study of the ferromagnetic Kondo lattice model for doped manganites, including the antiferromagnetic superexchange interaction ($J_{AF}$), we found that the ferromagnetic ordering was suppressed as $J_{AF}$ increased. The ferromagnetic transition temperature $T_c$, as obtained from a mean field fit to the calculated susceptibilities, was found to decrease monotonically with increasing $J_{AF}$. Further, the suppression in $T_c$ scales with the bandwidth narrowing induced by the antiferromagnetic frustration originating from $J_{AF}$. From these results, we propose that the change in the superexchange interaction strength between the $t_{2g}$ electrons of the Mn ions is one of the mechanisms responsible for the suppression in $T_c$ observed in manganites of the type (La$_{0.7-y}$Pr$_{y}$)Ca$_{0.3}$MnO$_3$.Comment: 5 pages, 6 figures. To appear in PR

Fossil Groups Origins III. Characterization of the sample and observational properties of fossil systems

(Abridged) Fossil systems are group- or cluster-sized objects whose luminosity is dominated by a very massive central galaxy. In the current cold dark matter scenario, these objects formed hierarchically at an early epoch of the Universe and then slowly evolved until present day. That is the reason why they are called {\it fossils}. We started an extensive observational program to characterize a sample of 34 fossil group candidates spanning a broad range of physical properties. Deep $r-$band images were taken for each candidate and optical spectroscopic observations were obtained for $\sim$ 1200 galaxies. This new dataset was completed with SDSS DR7 archival data to obtain robust cluster membership and global properties of each fossil group candidate. For each system, we recomputed the magnitude gaps between the two brightest galaxies ($\Delta m_{12}$) and the first and fourth ranked galaxies ($\Delta m_{14}$) within 0.5 $R_{{\rm 200}}$. We consider fossil systems those with $\Delta m_{12} \ge 2$ mag or $\Delta m_{14} \ge 2.5$ mag within the errors. We find that 15 candidates turned out to be fossil systems. Their observational properties agree with those of non-fossil systems. Both follow the same correlations, but fossils are always extreme cases. In particular, they host the brightest central galaxies and the fraction of total galaxy light enclosed in the central galaxy is larger in fossil than in non-fossil systems. Finally, we confirm the existence of genuine fossil clusters. Combining our results with others in the literature, we favor the merging scenario in which fossil systems formed due to mergers of $L^\ast$ galaxies. The large magnitude gap is a consequence of the extreme merger ratio within fossil systems and therefore it is an evolutionary effect. Moreover, we suggest that at least one candidate in our sample could represent a transitional fossil stage.Comment: 14 pages, 11 figures, accepted for publication in A&

Phytochemical Characterization and Antiplatelet Activity of Mexican Red Wines and Their By-products

Red wines and their grape pomaces are important sources of phenolic compounds. Inhibition of plateletaggregation is one of the mechanisms proposed for cardioprotective effect of phenolic compounds fromwine and grape pomace; however, phenolic content is affected by region, variety and winemaking process.In the present study, antiplatelet effect of red wines and grape pomaces was related to its phenolic content(determined by spectrophotometric techniques) and profile (determined using HPLC-MS/MS). in vitroAnti-platelet aggregation was determined using human platelets. Results showed that Zinfandel wine andCabernet Sauvignon grape pomace presented the highest phenolic content. Phenolic profiles presenteddifferences in the presence of flavonoids and oligomeric tannins. Results from platelet aggregationshowed that Merlot and Petit Verdot wines and Petit Verdot grape pomace sample presented the highestantiaggregant effect. These results indicate that antiplatelet effect could be related to phenolic profile thanphenolic content in wines and grape pomaces. Cardioprotective effect of red wines and grape pomacecould be related to specific compounds such as monomeric and polymeric flavan-3-ols

Disability and perceived stress in primary care patients with major depression

Background: Major depressive disorder (MDD) is highly prevalent in the Spanish primary care (PC) setting and the leading cause of disability in Spain. The aim of this study was to evaluate several key psychometric properties of the Sheehan Disability Scale (SDS) in patients with or without MDD and varying degrees of symptom severity using the Patient Health Questionnaire-9 (PHQ-9). Method: A total of 1, 704 PC patients participating in the PsicAP clinical trial completed the SDS and PHQ-9. We evaluated the factor structure, measurement invariance across gender, internal consistency, and the discriminative and predictive validity. Results: Confirmatory factor analyses revealed a unifactorial model of the SDS containing 4 items (SDS-4) with the best model fit (CFI: .99; GFI: .99; TLI: 96; RMSEA: .10). This model contained the three life domain items (work, family, and social life) plus perceived stress (PS) with significant loadings. The internal consistency of the SDS-4 was acceptable in patients with or without MDD, regardless of symptom severity. The SDS-4 also showed good discriminative capacity and acceptable predictive validity in all subsamples. Conclusions: These findings support the use of the SDS-4 to assess depression-related disability in patients at Spanish primary care centres

REGULATION OF BETA-ADRENOCEPTORS ACTIVITYUSING SYNTHETIC LIGHT-REGULATED MOLECULES

Beta-adrenoceptors (ß-AR) are prototypical G proteincoupled receptors and important pharmacological targets for many diseases. Indeed, a number of approved drugs target these receptors due to their key role on many physiological functions. Among other examples, we encounter ß1-AR antagonists (ß- Blockers), which constitute the first-line therapy for the treatment of heart diseases, and ß2-AR agonists, which act as bronchodilators for the treatment of breathing pathologies. Considering the relevance of these receptors, achieving a reversible and localised control of their activity would provide a powerful tool, both for its research applications and its clinical potential. In this context, photopharmacology arises as a potent approach. Photopharmacology is an emerging field based on the use of synthetic light-regulated molecules to allow reversible spatiotemporal control of target receptors in native tissues. These ligands have the potential to provide a precise and controllable therapeutic action with increased efficacy and reduced side effects. Moreover, the fine regulation on demand of the receptor activation state is of great interest for their study in non-modified cells, tissues and organisms. The present project provides the first proof of concept for beta-adrenoceptor photopharmacology. We first designed and synthesised libraries of lightregulated compounds in order to regulate ß-AR activity with spatiotemporal precision. Subsequent testing highlighted the successful development of compounds with promising pharmacological properties which can be reversibly and irreversibly controlled by light. The discovered molecules enable a fine control of ß-AR in their native environment that will certainly open the door to innovative research procedures and may inspire future personalized therapies targeting these receptors

In vitro and in vivo regulation of ß-Adrenoceptors signaling using synthetic light-regulated molecules

Beta-adrenoceptors (ß-AR) are prototypical G protein-coupled receptors (GPCR) and important pharmacological targets for numerous diseases. Indeed, a number of approved drugs target ß-AR, which are key regulators of many physiological functions. Among other examples, ß1-AR antagonists (known as ß-Blockers) are first-line therapies for the treatment of heart failure, and ß2-AR agonists, which act as bronchodilators, are widely used for the treatment of breathing pathologies. Considering the medical relevance of these receptors, achieving a reversible and localized control of their activity would provide a powerful research and clinical tool. GPCR signaling is currently recognized as a multidimensional process governed by molecular, spatial and temporal components. Uncovering the role of each of these dimensions is crucial to improve our knowledge on cell communication, to understand how different pathways give rise to cellular and physiological effects, and to know how can we interact with biological systems with precision using drugs. Photopharmacology is an emerging field in which light-sensitive molecules are used to control the function of a given target protein in native tissues. The modulation of the target activity is achieved by small, drug-like, photoregulated ligands. By the use of light, both spatial and temporal control of the compound activity can be achieved in unprecedented manners compared to conventional pharmacology. These ligands have the potential to provide highly precise and controllable therapeutic actions that may result in increased efficacies and reduced side effects. Importantly, photopharmacology may allow to gain mechanistic insight on the interplay between the activation time and the receptor location during signaling processes in non-modified cells, tissues and whole organisms. Our research focused on the generation of new molecular tools for beta-adrenoceptors photopharmacology will be presented in this communication. First, several libraries of light-sensitive compounds with the aim to regulate ß-AR activity with spatiotemporal precision were designed and synthesized. Subsequent testing in cell preparations demonstrated the successful development of compounds with promising pharmacological properties, which can be reversibly and irreversibly controlled by light. Among those, several hit compounds were identified as ligands for beta-1 and beta-2 adrenoceptors with low nanomolar activities. These libraries compounds were found to be active enough to become useful photopharmacological tools, so we also performed in vivo experiments to determine their research potential in physiological environments. Indeed, the discovered molecules enabled a fine control of ß-AR in their native environment. We believe that the results of these studies will certainly open the door to innovative research procedures and may inspire future therapies targeting ß-AR

Early-life fecal microbiome and metabolome dynamics in response to an intervention with infant formula containing specific prebiotics and postbiotics

This study examined fecal metabolome dynamics to gain greater functional insights into the interactions between nutrition and the activity of the developing gut microbiota in healthy term-born infants. The fecal samples used here originate from a randomized, controlled, double-blind clinical study that assessed the efficacy of infant formula with prebiotics and postbiotics (experimental arm) compared with a standard infant formula (control arm). A group of exclusively breast-fed term infants was used as a reference arm. First, conventional targeted physiological and microbial measurements were performed, which showed differences in fecal Bifidobacterium levels and corresponding activity (e.g., lactate levels). Next, the overall fecal microbiota composition was determined by 16S rRNA gene amplicon sequencing. The microbiota composition profiles showed several bacterial groups in the experimental arm to be significantly different from the control arm and mostly closer to the levels observed in the reference arm. Finally, we applied an untargeted UPLC-MS/MS approach to examine changes in the fecal metabolome. Fecal metabolome profiles showed the most distinct separation, up to 404 significantly different metabolites, between the study arms. Our data reveal that infant formula with specific prebiotics and postbiotics may trigger responses in the intestinal microbiota composition that brings the ensuing fecal metabolite profile of formula-fed infants closer toward those observed in breast-fed infants. Furthermore, our results demonstrate a clear need for establishing an infant gut metabolome reference database to translate these metabolite profile dynamics into functional and physiologically relevant responses. NEW &amp; NOTEWORTHY Untargeted metabolomics techniques can provide a ???snapshot??? of an ecosystem in response to environmental stimuli, such as nutritional interventions. Our analyses of fecal samples from infants demonstrate the potential of phenotyping by metabolomics while deciphering the complex interactions of early-life nutrition and gut microbiome development