342 research outputs found
Influence of star-forming galaxy selection on the galaxy main sequence
This work aims to determine how the galaxy main sequence (MS) changes using
seven different commonly used methods to select the star-forming galaxies
within VIPERS data over . The form and redshift evolution of
the MS will then be compared between selection methods. The star-forming
galaxies were selected using widely known methods: a specific star-formation
rate (sSFR), Baldwin, Phillips and Terlevich (BPT) diagram, 4000\AA\ spectral
break (D4000) cut and four colour-colour cuts: NUVrJ, NUVrK, u-r, and UVJ. The
main sequences were then fitted for each of the seven selection methods using a
Markov chain Monte Carlo forward modelling routine, fitting both a linear main
sequence and a MS with a high-mass turn-over to the star-forming galaxies. This
was done in four redshift bins of , ,
, and . The slopes of all star-forming
samples were found to either remain constant or increase with redshift, and the
scatters were approximately constant. There is no clear redshift dependency of
the presence of a high-mass turn-over for the majority of samples, with the
NUVrJ and NUVrK being the only samples with turn-overs only at low redshift. No
samples have turn-overs at all redshifts. Star-forming galaxies selected with
sSFR and u-r are the only samples to have no high-mass turn-over in all
redshift bins. The normalisation of the MS increases with redshift, as
expected. The scatter around the MS is lower than the 0.3~dex
typically seen in MS studies for all seven samples. The lack, or presence, of a
high-mass turn-over is at least partially a result of the method used to select
star-forming galaxies. However, whether a turn-over should be present or not is
unclear.Comment: 20 pages, 3 appendices, 14 figures, 5 tables, accepted for
publication in Astronomy & Astrophysic
Prediction of antipsychotics efficacy based on a polygenic risk score: a real-world cohort study.
Background: Response to antipsychotics is subject to a wide interindividual variability, due to genetic and non-genetic factors. Several single nucleotide polymorphisms (SNPs) have been associated with response to antipsychotics in genome-wide association studies (GWAS). Polygenic risk scores (PRS) are a powerful tool to aggregate into a single measure the small effects of multiple risk alleles. Materials and methods: We studied the association between a PRS composed of SNPs associated with response to antipsychotics in GWAS studies (PRS <sub>response</sub> ) in a real-world sample of patients (N = 460) with different diagnoses (schizophrenia spectrum, bipolar, depressive, neurocognitive, substance use disorders and miscellaneous). Two other PRSs composed of SNPs previously associated with risk of schizophrenia (PRS <sub>schizophrenia1</sub> and PRS <sub>schizophrenia2</sub> ) were also tested for their association with response to treatment. Results: PRS <sub>response</sub> was significantly associated with response to antipsychotics considering the whole cohort (OR = 1.14, CI = 1.03-1.26, p = 0.010), the subgroup of patients with schizophrenia, schizoaffective disorder or bipolar disorder (OR = 1.18, CI = 1.02-1.37, p = 0.022, N = 235), with schizophrenia or schizoaffective disorder (OR = 1.24, CI = 1.04-1.47, p = 0.01, N = 176) and with schizophrenia (OR = 1.27, CI = 1.04-1.55, p = 0.01, N = 149). Sensitivity and specificity were sub-optimal (schizophrenia 62%, 61%; schizophrenia spectrum 56%, 55%; schizophrenia spectrum plus bipolar disorder 60%, 56%; all patients 63%, 58%, respectively). PRS <sub>schizophrenia1</sub> and PRS <sub>schizophrenia2</sub> were not significantly associated with response to treatment. Conclusion: PRS <sub>response</sub> defined from GWAS studies is significantly associated with response to antipsychotics in a real-world cohort; however, the results of the sensitivity-specificity analysis preclude its use as a predictive tool in clinical practice
Prediction of antipsychotics efficacy based on a polygenic risk score: a real-world cohort study
Background: Response to antipsychotics is subject to a wide interindividual variability, due to genetic and non-genetic factors. Several single nucleotide polymorphisms (SNPs) have been associated with response to antipsychotics in genome-wide association studies (GWAS). Polygenic risk scores (PRS) are a powerful tool to aggregate into a single measure the small effects of multiple risk alleles. Materials and methods: We studied the association between a PRS composed of SNPs associated with response to antipsychotics in GWAS studies (PRSresponse) in a real-world sample of patients (N = 460) with different diagnoses (schizophrenia spectrum, bipolar, depressive, neurocognitive, substance use disorders and miscellaneous). Two other PRSs composed of SNPs previously associated with risk of schizophrenia (PRSschizophrenia1 and PRSschizophrenia2) were also tested for their association with response to treatment. Results: PRSresponse was significantly associated with response to antipsychotics considering the whole cohort (OR = 1.14, CI = 1.03–1.26, p = 0.010), the subgroup of patients with schizophrenia, schizoaffective disorder or bipolar disorder (OR = 1.18, CI = 1.02–1.37, p = 0.022, N = 235), with schizophrenia or schizoaffective disorder (OR = 1.24, CI = 1.04–1.47, p = 0.01, N = 176) and with schizophrenia (OR = 1.27, CI = 1.04–1.55, p = 0.01, N = 149). Sensitivity and specificity were sub-optimal (schizophrenia 62%, 61%; schizophrenia spectrum 56%, 55%; schizophrenia spectrum plus bipolar disorder 60%, 56%; all patients 63%, 58%, respectively). PRSschizophrenia1 and PRSschizophrenia2 were not significantly associated with response to treatment. Conclusion: PRSresponse defined from GWAS studies is significantly associated with response to antipsychotics in a real-world cohort; however, the results of the sensitivity-specificity analysis preclude its use as a predictive tool in clinical practice
The Exposure to Osteoarthritic Synovial Fluid Enhances the Immunomodulatory Profile of Adipose Mesenchymal Stem Cell Secretome
Objective. Several clinical studies have proposed the infusion of adipose mesenchymal stem cells (AMSCs) as an alternative therapy for joint diseases with inflammatory components, such as osteoarthritis. Indeed, AMSCs are able to stimulate tissue repair through a paracrine activity and the interaction with the inflammatory microenvironment seems to have a critical role. Design. To reproduce the inflammatory microenvironment, AMSCs were exposed to osteoarthritic synovial fluid (SF) for 48 h and the effect of their secretome on differentiation of monocytes (M0) into macrophages M1-like and mature dendritic cells (mDCs) was evaluated. Furthermore, the effect of the secretome of AMSCs exposed to SF was evaluated on the T cell population in terms of T cell proliferation and expansion of T regulatory cells (T reg). Results. Our data show that the exposure of AMSCs to SF activates cells and promotes the release of immunosuppressive factors, which induce macrophage polarization of M0 into the M2-like phenotype and inhibit differentiation of monocytes into mature dendritic cells (mDCs). Only the secretome of exposed AMSCs was able to inhibit T cell proliferation and promote T reg expansion. Conclusions. Our results suggest that the microenvironment plays a fundamental role for the development of anti-inflammatory and immunomodulatory properties of AMSCs
Decoding the IRX-\beta\ dust attenuation relation in star-forming galaxies at intermediate redshift
We aim to understand what drives the IRX-\beta dust attenuation relation at
intermediate redshift (0.5 < z < 0.8) in star-forming galaxies. We investigate
the role of various galaxy properties in shaping this observed relation. We use
robust [O ii] {\lambda}3727, [O iii] {\lambda}{\lambda}4959, 5007, and H\beta
line detections of our statistical sample of 1049 galaxies to estimate the
gas-phase metallicities. We derive key physical properties that are necessary
to study galaxy evolution, such as the stellar masses and the star formation
rates, using the spectral energy distribution fitting tool CIGALE.
Equivalently, we study the effect of galaxy morphology (mainly the S\'ersic
index n and galaxy inclination) on the observed IRX-\beta scatter. We also
investigate the role of the environment in shaping dust attenuation in our
sample. We find a strong correlation of the IRX-\beta relation on gas-phase
metallicity in our sample, and also strong correlation with galaxy compactness
characterized by the S\'ersic indexes. Correlations are also seen with stellar
masses, specific star formation rates and the stellar ages of our sources.
Metallicity strongly correlates with the IRX-\beta scatter, this also results
from the older stars and higher masses at higher beta values. Galaxies with
higher metallicities show higher IRX and higher beta values. The correlation
with specific dust mass strongly shifts the galaxies away from the IRX-\beta
relation towards lower \b{eta} values. We find that more compact galaxies
witness a larger amount of attenuation than less compact galaxies. There is a
subtle variation in the dust attenuation scatter between edge-on and face-on
galaxies, but the difference is not statistically significant. Galaxy
environments do not significantly affect dust attenuation in our sample of
star-forming galaxies at intermediate redshift.Comment: 14 pages, 13 figures, accepted for publication in A&
Obesity and atypical depression symptoms: findings from Mendelian randomization in two European cohorts.
Studies considering the causal role of body mass index (BMI) for the predisposition of major depressive disorder (MDD) based on a Mendelian Randomization (MR) approach have shown contradictory results. These inconsistent findings may be attributable to the heterogeneity of MDD; in fact, several studies have documented associations between BMI and mainly the atypical subtype of MDD. Using a MR approach, we investigated the potential causal role of obesity in both the atypical subtype and its five specific symptoms assessed according to the Statistical Manual of Mental Disorders (DSM), in two large European cohorts, CoLaus|PsyCoLaus (n = 3350, 1461 cases and 1889 controls) and NESDA|NTR (n = 4139, 1182 cases and 2957 controls). We first tested general obesity measured by BMI and then the body fat distribution measured by waist-to-hip ratio (WHR). Results suggested that BMI is potentially causally related to the symptom increase in appetite, for which inverse variance weighted, simple median and weighted median MR regression estimated slopes were 0.68 (SE = 0.23, p = 0.004), 0.77 (SE = 0.37, p = 0.036), and 1.11 (SE = 0.39, p = 0.004). No causal effect of BMI or WHR was found on the risk of the atypical subtype or for any of the other atypical symptoms. Our findings show that higher obesity is likely causal for the specific symptom of increase in appetite in depressed participants and reiterate the need to study depression at the granular level of its symptoms to further elucidate potential causal relationships and gain additional insight into its biological underpinnings
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