Infrared Excess Sources: Compton Thick QSOs, low luminosity Seyferts or starbursts?

We explore the nature of Infrared Excess sources (IRX), which are proposed as candidates for luminous L_X(2-10keV)>1e43erg/s Compton Thick (N_H>2e24cm^{-2}$) QSOs at z~2. Lower redshift, z~1, analogues of the distant IRX population are identified by firstly redshifting to z=2 the SEDs of all sources with secure spectroscopic redshifts in the AEGIS (6488) and the GOODS-North (1784) surveys and then selecting those that qualify as IRX sources at that redshift. A total of 19 galaxies are selected. The mean redshift of the sample is$z\approx1$. We do not find strong evidence for Compton Thick QSOs in the sample. For 9 sources with X-ray counterparts, the X-ray spectra are consistent with Compton Thin AGN. Only 3 of them show tentative evidence for Compton Thick obscuration. The SEDs of the X-ray undetected population are consistent with starburst activity. There is no evidence for a hot dust component at the mid-infrared associated with AGN heated dust. If the X-ray undetected sources host AGN, an upper limit of L_X(2-10keV) =1e43erg/s is estimated for their intrinsic luminosity. We propose that a large fraction of the$z\approx2$ IRX population are not Compton Thick QSOs but low luminosity [L_X(2-10keV)<1e43erg/s], possibly Compton Thin, AGN or dusty starbursts. It is shown that the decomposition of the AGN and starburst contribution to the mid-IR is essential for interpreting the nature of this population, as star-formation may dominate this wavelength regime.Comment: Accepted by MNRA

Loss of the PTCH1 tumor suppressor defines a new subset of plexiform fibromyxoma.

BackgroundPlexiform fibromyxoma (PF) is a rare gastric tumor often confused with gastrointestinal stromal tumor. These so-called "benign" tumors often present with upper GI bleeding and gastric outlet obstruction. It was recently demonstrated that approximately one-third of PF have activation of the GLI1 oncogene, a transcription factor in the hedgehog (Hh) pathway, via a MALAT1-GLI1 fusion protein or GLI1 up-regulation. Despite this discovery, the biology of most PFs remains unknown.MethodsNext generation sequencing (NGS) was performed on formalin-fixed paraffin-embedded (FFPE) samples of PF specimens collected from three institutions (UCSD, NCI and OHSU). Fresh frozen tissue from one tumor was utilized for in vitro assays, including quantitative RT-PCR and cell viability assays following drug treatment.ResultsEight patients with PF were identified and 5 patients' tumors were analyzed by NGS. An index case had a mono-allelic PTCH1 deletion of exons 15-24 and a second case, identified in a validation cohort, also had a PTCH1 gene loss associated with a suspected long-range chromosome 9 deletion. Building on the role of Hh signaling in PF, PTCH1, a tumor suppressor protein, functions upstream of GLI1. Loss of PTCH1 induces GLI1 activation and downstream gene transcription. Utilizing fresh tissue from the index PF case, RT-qPCR analysis demonstrated expression of Hh pathway components, SMO and GLI1, as well as GLI1 transcriptional targets, CCND1 and HHIP. In turn, short-term in vitro treatment with a Hh pathway inhibitor, sonidegib, resulted in dose-dependent cell killing.ConclusionsFor the first time, we report a novel association between PTCH1 inactivation and the development of plexiform fibromyxoma. Hh pathway inhibition with SMO antagonists may represent a target to study for treating a subset of plexiform fibromyxomas

The Imperial IRAS-FSC Redshift Catalogue: luminosity functions, evolution and galaxy bias

We present the luminosity function and selection function of 60 micron galaxies selected from the Imperial IRAS-FSC Redshift Catalogue (IIFSCz). Three methods, including the 1/Vmax} and the parametric and non-parametric maximum likelihood estimator, are used and results agree well with each other. A density evolution proportional to (1+z)^3.4 or a luminosity evolution exp(1.7 t_L / \tau)$ where t_L is the look-back time is detected in the full sample in the redshift range [0.02, 0.1], consistent with previous analyses. Of the four infrared subpopulations, cirrus-type galaxies and M82-type starbursts show similar evolutionary trends, galaxies with significant AGN contributions show stronger positive evolution and Arp 220-type starbursts exhibit strong negative evolution. The dominant subpopulation changes from cirrus-type galaxies to M82-type starbursts at log (L_60 / L_Sun) ~ 10.3. In the second half of the paper, we derive the projected two-point spatial correlation function for galaxies of different infrared template type. The mean relative bias between cirrus-type galaxies and M82-type starbursts, which correspond to quiescent galaxies with optically thin interstellar dust and actively star-forming galaxies respectively, is calculated to be around 1.25. The relation between current star formation rate (SFR) in star-forming galaxies and environment is investigated by looking at the the dependence of clustering on infrared luminosity. We found that M82-type actively star-forming galaxies show stronger clustering as infrared luminosity / SFR increases. The correlation between clustering strength and SFR in the local Universe seems to echo the basic trend seen in star-forming galaxies in the Great Observatories Origins Deep Survey (GOODS) fields at z ~ 1.Comment: 15 pages, 11 figures, accepted for publication in MNRA

Human decellularized dermal matrix seeded with adipose-derived stem cells enhances wound healing in a murine model : experimental study

Objective: Full-thickness cutaneous wounds treated with split-thickness skin grafts often result in unaesthetic and hypertrophic scars. Dermal substitutes are currently used together with skin grafts in a single treatment to reconstruct the dermal layer of the skin, resulting in improved quality of scars. Adipose-derived stem cells (ASCs) have been described to enhance wound healing through structural and humoral mechanisms. In this study, we investigate the compatibility of xenogen-free isolated human ASCs seeded on human acellular dermal matrix (Glyaderm (R)) in a murine immunodeficient wound model. Methods: Adipose tissue was obtained from abdominal liposuction, and stromal cells were isolated mechanically and cultured xenogen-free in autologous plasma-supplemented medium. Glyaderm (R) discs were seeded with EGFP-transduced ASCs, and implanted on 8 mm full-thickness dorsal wounds in an immunodeficient murine model, in comparison to standard Glyaderm (R) discs. Re-epithelialization rate, granulation thickness and vascularity were assessed by histology on days 3, 7 and 12. Statistical analysis was conducted using the Wilcoxon signed-rank test. EGFP-staining allowed for tracking of the ASCs in vivo. Hypoxic culture of the ASCs was performed to evaluate cytokine production. Results: ASCs were characterized with flowcytometric analysis and differentiation assay. EGFP-tranduction resulted in 95% positive cells after sorting. Re-epithelialization in the ASC-seeded Glyaderm (R) side was significantly increased, resulting in complete wound healing in 12 days. Granulation thickness and vascularization were significantly increased during early wound healing. EGFP-ASCs could be retrieved by immunohistochemistry in the granulation tissue in early wound healing, and lining vascular structures in later stages. Conclusion: Glyaderm (R) is an effective carrier to deliver ASCs in full-thickness wounds. ASC-seeded Glyaderm (R) significantly enhances wound healing compared to standard Glyaderm (R). The results of this study encourage clinical trials for treatment of full-thickness skin defects. Furthermore, xenogen-free isolation and autologous plasma-augmented culture expansion of ASCs, combined with the existing clinical experience with Glyaderm (R), aid in simplifying the necessary procedures in a GMP-laboratory setting

The Comoving Infrared Luminosity Density: Domination of Cold Galaxies across 0<z<1

In this paper we examine the contribution of galaxies with different infrared (IR) spectral energy distributions (SEDs) to the comoving infrared luminosity density, a proxy for the comoving star formation rate (SFR) density. We characterise galaxies as having either a cold or hot IR SED depending upon whether the rest-frame wavelength of their peak IR energy output is above or below 90um. Our work is based on a far-IR selected sample both in the local Universe and at high redshift, the former consisting of IRAS 60um-selected galaxies at z<0.07 and the latter of Spitzer 70um selected galaxies across 0.1<z<1. We find that the total IR luminosity densities for each redshift/luminosity bin agree well with results derived from other deep mid/far-IR surveys. At z<0.07 we observe the previously known results: that moderate luminosity galaxies (L_IR<10^11 Lsun) dominate the total luminosity density and that the fraction of cold galaxies decreases with increasing luminosity, becoming negligible at the highest luminosities. Conversely, above z=0.1 we find that luminous IR galaxies (L_IR>10^11 Lsun), the majority of which are cold, dominate the IR luminosity density. We therefore infer that cold galaxies dominate the IR luminosity density across the whole 0<z<1 range, hence appear to be the main driver behind the increase in SFR density up to z~1 whereas local luminous galaxies are not, on the whole, representative of the high redshift population.Comment: 5 pages, 3 figures, accepted for publication in MNRA

Structured Collaboration Across a Transformative Knowledge Network-Learning Across Disciplines, Cultures and Contexts?

Realising the Sustainable Development Goals (SDGs) will require transformative changes at micro, meso and macro levels and across diverse geographies. Collaborative, transdisciplinary research has a role to play in documenting, understanding and contributing to such transformations. Previous work has investigated the role of this research in Europe and North America, however the dynamics of transdisciplinary research on ‘transformations to sustainability’ in other parts of the world are less well-understood. This paper reports on an international project that involved transdisciplinary research in six different hubs across the globe and was strategically designed to enable mutual learning and exchange. It draws on surveys, reports and research outputs to analyse the processes of transdisciplinary collaboration for sustainability that took place between 2015-2019. The paper illustrates how the project was structured in order to enable learning across disciplines, cultures and contexts, and describes how it also provided for the negotiation of epistemological frameworks and different normative commitments between members across the network. To this end, it discusses lessons regarding the use of theoretical and methodological anchors, multi-loop learning and evaluating emergent change (including the difficulties encountered). It offers insights for the design and implementation of future international transdisciplinary collaborations that address locally-specific sustainability challenges within the universal framework of the 2030 Agenda for Sustainable Development

Photometric redshifts for the CFHTLS T0004 Deep and Wide fields

We compute photometric redshifts based on the template-fitting method in the fourth public release of the Canada-France-Hawaii Telescope Legacy Survey. This unique multi-colour catalogue comprises u*,g',r',i',z' photometry in four deep fields of 1 deg2 each and 35 deg2 distributed over three Wide fields. Our photometric redshifts are calibrated with and compared to 16,983 high-quality spectroscopic redshifts from several surveys. We find a dispersion of 0.028 and an outlier rate of 3.5% in the Deep field at i'AB < 24 and a dispersion of 0.036 and an outlier rate of 2.8% in the Wide field at i'AB < 22.5. Beyond i'AB = 22.5 in the Wide field the number of outliers rises from 5% to 10% at i'AB<23 and i'AB<24 respectively. For the Wide sample, we find the systematic redshift bias keeps below 1% to i'AB < 22.5, whereas we find no significant bias in the Deep field. We investigated the effect of tile-to-tile photometric variations and demonstrate that the accuracy of our photometric redshifts is reduced by at most 21%. We separate stars from galaxies using both the size and colour information, reducing the contamination by stars in our catalogues from 50% to 8% at i'AB < 22.5 in fields with the highest stellar density while keeping a complete galaxy sample. Our CFHTLS T0004 photometric redshifts are distributed to the community. Our release include 592,891 (i'AB < 22.5) and 244,701 (i'AB < 24) reliable galaxy photometric redshifts in the Wide and Deep fields, respectively.Comment: 18 pages, 17 figure

Towards the optimal window for the 2MASS dipole

A comparison of the 2MASS flux dipole to the CMB dipole can serve as a method to constrain a combination of the cosmological parameter Omega_m and the luminosity bias of the 2MASS survey. For this constraint to be as tight as possible, it is necessary to maximize the correlation between the two dipoles. This can be achieved by optimizing the survey window through which the flux dipole is measured. Here we explicitly construct such a window for the 2MASS survey. The optimization in essence reduces to excluding from the calculation of the flux dipole galaxies brighter than some limiting magnitude K_min of the near-infrared K_s band. This exclusion mitigates nonlinear effects and shot noise from small scales, which decorrelate the 2MASS dipole from the CMB dipole. Under the assumption of negligible shot noise we find that the optimal value of K_min is about five. Inclusion of shot noise shifts the optimal K_min to larger values. We present an analytical formula for shot noise for the 2MASS flux dipole, to be used in follow-up work with 2MASS data. The misalignment angle between the two dipoles is a sensitive measure of their correlation: the higher the correlation, the smaller the expectation value of the angle. A minimum of the misalignment is thus a sign of the optimal gravity window. We model analytically the distribution function for the misalignment angle and show that the misalignment estimated by Maller et al. is consistent with the assumed underlying model (though it is greater than the expectation value). We predict with about 90% confidence that the misalignment will decrease if 2MASS galaxies brighter than K_min = 5 mag are excluded from the calculation of the flux dipole. This prediction has been indirectly confirmed by the results of Erdogdu et al. (ABRIDGED)Comment: 14 pages, 3 figures. Significantly expanded version, with added sections on shot noise and likelihood for beta, as well as an appendix with a derivation of the distribution for the misalignment angle relaxing the small-angle assumptio

Dipoles in the Sky

We perform observational tests of statistical isotropy using data from large-scale structure surveys spanning a wide range of wavelengths. Using data from 2MASS, 2MRS, and NVSS galaxies, and BATSE gamma-ray bursts, we constrain the amplitude and direction of dipolar modulations in the number count of sources projected along the line of sight. We pay particular attention to the treatment of systematic errors and selection effects, and carefully distinguish between different sources of dipole signal previously considered in the literature. Dipole signals detected in these surveys are consistent with the standard, statistically isotropic expectation, except for the NVSS result, which is likely biased by remaining systematics in the data. We place constraints on the amplitude of any intrinsic dipole driven by novel physics in the early universe.Comment: 36 pages, 20 figures. v3: minor additions to theory section; matches the published MNRAS versio