432 research outputs found

    Planck pre-launch status: HFI beam expectations from the optical optimisation of the focal plane

    Get PDF
    Planck is a European Space Agency (ESA) satellite, launched in May 2009, which will map the cosmic microwave background anisotropies in intensity and polarisation with unprecedented detail and sensitivity. It will also provide full-sky maps of astrophysical foregrounds. An accurate knowledge of the telescope beam patterns is an essential element for a correct analysis of the acquired astrophysical data. We present a detailed description of the optical design of the High Frequency Instrument (HFI) together with some of the optical performances measured during the calibration campaigns. We report on the evolution of the knowledge of the pre-launch HFI beam patterns when coupled to ideal telescope elements, and on their significance for the HFI data analysis procedure

    GATA transcription factors drive initial Xist upregulation after fertilization through direct activation of a distal enhancer element

    Get PDF
    To ensure dosage compensation for X-linked genes between the sexes, one X chromosome is silenced during early embryonic development of female mammals. This process of X-chromosome inactivation (XCI) is initiated through upregulation of the RNA Xist from one X chromosome shortly after fertilization. Xist then mediates chromosome-wide gene silencing in cis and remains expressed in all cell types except the germ line and the pluripotent state, where XCI is reversed. The factors that drive Xist upregulation and thereby initiate XCI remain however unknown. We identify GATA transcription factors as potent Xist activators and demonstrate that they are essential for the activation of Xist in mice following fertilization. Through a pooled CRISPR activation screen we find that GATA1 can drive ectopic Xist expression in murine embryonic stem cells (mESCs). We demonstrate that all GATA factors can activate Xist directly via a GATA-responsive regulatory element (RE79) positioned 100 kb upstream of the Xist promoter. Additionally, GATA factors are essential for the induction of XCI in mouse preimplantation embryos, as simultaneous deletion of three members of the GATA family (GATA1/4/6) in mouse zygotes effectively prevents Xist upregulation. Thus, initiation of XCI and possibly its maintenance in distinct lineages of the preimplantation embryo is ensured by the combined activity of different GATA family members, and the absence of GATA factors in the pluripotent state likely contributes to X reactivation. We thus describe a form of regulation in which the combined action of numerous tissue-specific factors can achieve near-ubiquitous expression of a target gene

    Multimode horn antennas for far-infrared astronomy

    Get PDF
    Multi-mode horns combined with bolometric or incoherent detectors are finding application in astronomical receivers for which partially coherent operation can provide increased throughput and thus sensitivity. This is advantageous when observing faint sources, especially if diffraction limited resolution is not required, or if the horn beam is truncated by a cold stop in the optical train. We discuss how such horns can be simulated and present examples from receiver instrumentation on the Planck and SPICA space telescopes

    Circulating miR-26b-5p and miR-451a as diagnostic biomarkers in medullary thyroid carcinoma patients

    Get PDF
    Purpose/methodsThe determination of tumour biomarkers is paramount to advancing personalized medicine, more so in rare tumours like medullary thyroid carcinoma (MTC), whose diagnosis is still challenging. The aim of this study was to identify non-invasive circulating biomarkers in MTC. To achieve this goal, paired MTC tissue and plasma extracellular vesicle samples were collected from multiple centres and microRNA (miRNA) expression levels were evaluated.ResultsThe samples from a discovery cohort of 23 MTC patients were analysed using miRNA arrays. Lasso logistic regression analysis resulted in the identification of a set of circulating miRNAs as diagnostic biomarkers. Among them, miR-26b-5p and miR-451a, were highly expressed and their expression decreased during follow-up in disease-free patients in the discovery cohort. Circulating miR-26b-5p and miR-451a were validated using droplet digital PCR in a second independent cohort of 12 MTC patients.ConclusionThis study allowed the identification and validation of a signature of two circulating miRNAs, miR-26b-5p and miR-451a, in two independent cohorts reporting a significant diagnostic performance for MTC. The results of this study offer advancements in molecular diagnosis of MTC proposing a novel non-invasive tool to use in precision medicine

    Landscape of immune-related signatures induced by targeting of different epigenetic regulators in melanoma: implications for immunotherapy

    Get PDF
    Background Improvement of efficacy of immune checkpoint blockade (ICB) remains a major clinical goal. Association of ICB with immunomodulatory epigenetic drugs is an option. However, epigenetic inhibitors show a heterogeneous landscape of activities. Analysis of transcriptional programs induced in neoplastic cells by distinct classes of epigenetic drugs may foster identification of the most promising agents. Methods Melanoma cell lines, characterized for mutational and differentiation profile, were treated with inhibitors of DNA methyltransferases (guadecitabine), histone deacetylases (givinostat), BET proteins (JQ1 and OTX-015), and enhancer of zeste homolog 2 (GSK126). Modulatory effects of epigenetic drugs were evaluated at the gene and protein levels. Master molecules explaining changes in gene expression were identified by Upstream Regulator (UR) analysis. Gene set enrichment and IPA were used respectively to test modulation of guadecitabine-specific gene and UR signatures in baseline and on-treatment tumor biopsies from melanoma patients in the Phase Ib NIBIT-M4 Guadecitabine + Ipilimumab Trial. Prognostic significance of drug-specific immune-related genes was tested with Timer 2.0 in TCGA tumor datasets. Results Epigenetic drugs induced different profiles of gene expression in melanoma cell lines. Immune-related genes were frequently upregulated by guadecitabine, irrespective of the mutational and differentiation profiles of the melanoma cell lines, to a lesser extent by givinostat, but mostly downregulated by JQ1 and OTX-015. GSK126 was the least active drug. Quantitative western blot analysis confirmed drug-specific modulatory profiles. Most of the guadecitabine-specific signature genes were upregulated in on-treatment NIBIT-M4 tumor biopsies, but not in on-treatment lesions of patients treated only with ipilimumab. A guadecitabine-specific UR signature, containing activated molecules of the TLR, NF-kB, and IFN innate immunity pathways, was induced in drug-treated melanoma, mesothelioma and hepatocarcinoma cell lines and in a human melanoma xenograft model. Activation of guadecitabine-specific UR signature molecules in on-treatment tumor biopsies discriminated responding from non-responding NIBIT-M4 patients. Sixty-five % of the immune-related genes upregulated by guadecitabine were prognostically significant and conferred a reduced risk in the TCGA cutaneous melanoma dataset. Conclusions The DNMT inhibitor guadecitabine emerged as the most promising immunomodulatory agent among those tested, supporting the rationale for usage of this class of epigenetic drugs in combinatorial immunotherapy approaches. © 2022, The Author(s)

    Daclatasvir vs telaprevir plus peginterferon alfa/ribavirin for hepatitis C virus genotype 1

    Get PDF
    AIM: To evaluate daclatasvir vs telaprevir, each combined with peginterferon alfa-2a/ribavirin (pegIFN/RBV), in treatment-naive hepatitis C virus (HCV) genotype (GT) 1-infected patients. METHODS: In this phase 3, randomized, open-label, noninferiority study, 602 patients were randomly assigned (2:1) to daclatasvir vs telaprevir, stratified by IL28B rs12979860 host genotype (CC vs non-CC), cirrhosis status (compensated cirrhosis vs no cirrhosis), and HCV GT1 subtype (GT1a vs GT1b). Patients were selected by study inclusion criteria from a total of 793 enrolled patients. Patients received daclatasvir 60 mg once daily or telaprevir 750 mg 3 times daily plus pegIFN/RBV. Daclatasvir recipients received 24 wk of daclatasvir plus pegIFN/RBV; those without an extended rapid virologic response (eRVR; undetectable HCV-RNA at weeks 4 and 12) received an additional 24 wk of pegIFN/RBV. Telaprevir-treated patients received 12 wk of telaprevir plus pegIFN/RBV followed by 12 (with eRVR) or 36 (no eRVR) wk of pegIFN/RBV. The primary objective was to compare for noninferiority of sustained virologic response rates at posttreatment week 12 (SVR12) in GT1b-infected patients. Key secondary objectives were to demonstrate that the rates of anemia (hemoglobin < 10 g/dL) and rash-related events, through week 12, were lower with daclatasvir + pegIFN/RBV than with telaprevir + pegIFN/RBV among GT1b-infected patients. Resistance testing was performed using population-based sequencing of the NS5A region for all patients at baseline, and for patients with virologic failure or relapse and HCV-RNA ≥ 1000 IU/mL, to investigate any link between NS5A polymorphisms associated with daclatasvir resistance and virologic outcome. RESULTS: Patient demographics and disease characteristics were generally balanced across treatment arms; however, there was a higher proportion of black/African Americans in the daclatasvir groups (6.0% and 8.2% in the GT1b and GT1a groups, respectively) than in the telaprevir groups (2.2% and 3.0%). Among GT1b-infected patients, daclatasvir plus pegIFN/RBV was noninferior to telaprevir plus pegIFN/RBV for SVR12 [85% (228/268) vs 81% (109/134); difference, 4.3% (95%CI: -3.3% to 11.9%)]. Anemia (hemoglobin < 10 g/dL) was significantly less frequent with daclatasvir than with telaprevir [difference, -29.1% (95%CI: -38.8% to -19.4%)]. Rash-related events were also less common with daclatasvir than with telaprevir, but the difference was not statistically significant. In GT1a-infected patients, SVR12 was 64.9% with daclatasvir and 69.7% with telaprevir. Among both daclatasvir and telaprevir treatment groups, across GT1b- or GT1a-infected patients, lower response rates were observed in patients with IL28B non-CC and cirrhosis - factors known to affect response to pegIFN/RBV. Consistent with these observations, a multivariate logistic regression analysis in GT1b-infected patients demonstrated that SVR12 was associated with IL28B host genotype (CC vs non-CC, P = 0.011) and cirrhosis status (absent vs present, P = 0.031). NS5A polymorphisms associated with daclatasvir resistance (at L28, R30, L31, or Y93) were observed in 17.3% of GT1b-infected patients at baseline; such variants did not appear to be absolute predictors of failure since 72.1% of these patients achieved SVR12 compared with 86.9% without these polymorphisms. Among GT1b-infected patients, treatment was completed by 85.4% (229/268) in the daclatasvir group, and by 85.1% (114/134) in the telaprevir group, and among GT1a-infected patients, by 67.2% (90/134) and 69.7% (46/66), respectively. Discontinuations (of all 3 agents) due to an AE were more frequent with telaprevir than with daclatasvir, whereas discontinuations due to lack of efficacy were more frequent with daclatasvir, due, in part, to differences in futility criteria. CONCLUSION: Daclatasvir plus pegIFN/RBV demonstrated noninferiority to telaprevir plus pegIFN/RBV for SVR12 and was well-tolerated in treatment-naive GT1b-infected patients, supporting the use of daclatasvir with other direct-acting antivirals

    Planck Intermediate Results. IX. Detection of the Galactic haze with Planck

    Get PDF
    Using precise full-sky observations from Planck, and applying several methods of component separation, we identify and characterize the emission from the Galactic "haze" at microwave wavelengths. The haze is a distinct component of diffuse Galactic emission, roughly centered on the Galactic centre, and extends to |b| ~35 deg in Galactic latitude and |l| ~15 deg in longitude. By combining the Planck data with observations from the WMAP we are able to determine the spectrum of this emission to high accuracy, unhindered by the large systematic biases present in previous analyses. The derived spectrum is consistent with power-law emission with a spectral index of -2.55 +/- 0.05, thus excluding free-free emission as the source and instead favouring hard-spectrum synchrotron radiation from an electron population with a spectrum (number density per energy) dN/dE ~ E^-2.1. At Galactic latitudes |b|<30 deg, the microwave haze morphology is consistent with that of the Fermi gamma-ray "haze" or "bubbles," indicating that we have a multi-wavelength view of a distinct component of our Galaxy. Given both the very hard spectrum and the extended nature of the emission, it is highly unlikely that the haze electrons result from supernova shocks in the Galactic disk. Instead, a new mechanism for cosmic-ray acceleration in the centre of our Galaxy is implied.Comment: 15 pages, 9 figures, submitted to Astronomy and Astrophysic

    Planck Intermediate Results. IV. The XMM-Newton validation programme for new Planck galaxy clusters

    Get PDF
    We present the final results from the XMM-Newton validation follow-up of new Planck galaxy cluster candidates. We observed 15 new candidates, detected with signal-to-noise ratios between 4.0 and 6.1 in the 15.5-month nominal Planck survey. The candidates were selected using ancillary data flags derived from the ROSAT All Sky Survey (RASS) and Digitized Sky Survey all-sky maps, with the aim of pushing into the low SZ flux, high-z regime and testing RASS flags as indicators of candidate reliability. 14 new clusters were detected by XMM, including 2 double systems. Redshifts lie in the range 0.2 to 0.9, with 6 clusters at z>0.5. Estimated M500 range from 2.5 10^14 to 8 10^14 Msun. We discuss our results in the context of the full XMM validation programme, in which 51 new clusters have been detected. This includes 4 double and 2 triple systems, some of which are chance projections on the sky of clusters at different z. We find that association with a RASS-BSC source is a robust indicator of the reliability of a candidate, whereas association with a FSC source does not guarantee that the SZ candidate is a bona fide cluster. Nevertheless, most Planck clusters appear in RASS maps, with a significance greater than 2 sigma being a good indication that the candidate is a real cluster. The full sample gives a Planck sensitivity threshold of Y500 ~ 4 10^-4 arcmin^2, with indication for Malmquist bias in the YX-Y500 relation below this level. The corresponding mass threshold depends on z. Systems with M500 > 5 10^14 Msun at z > 0.5 are easily detectable with Planck. The newly-detected clusters follow the YX-Y500 relation derived from X-ray selected samples. Compared to X-ray selected clusters, the new SZ clusters have a lower X-ray luminosity on average for their mass. There is no indication of departure from standard self-similar evolution in the X-ray versus SZ scaling properties. (abridged)Comment: accepted by A&

    Planck 2015 results. XXIII. The thermal Sunyaev-Zeldovich effect--cosmic infrared background correlation

    Get PDF
    We use Planck data to detect the cross-correlation between the thermal Sunyaev-Zeldovich (tSZ) effect and the infrared emission from the galaxies that make up the the cosmic infrared background (CIB). We first perform a stacking analysis towards Planck-confirmed galaxy clusters. We detect infrared emission produced by dusty galaxies inside these clusters and demonstrate that the infrared emission is about 50% more extended than the tSZ effect. Modelling the emission with a Navarro--Frenk--White profile, we find that the radial profile concentration parameter is c500=1.000.15+0.18c_{500} = 1.00^{+0.18}_{-0.15}. This indicates that infrared galaxies in the outskirts of clusters have higher infrared flux than cluster-core galaxies. We also study the cross-correlation between tSZ and CIB anisotropies, following three alternative approaches based on power spectrum analyses: (i) using a catalogue of confirmed clusters detected in Planck data; (ii) using an all-sky tSZ map built from Planck frequency maps; and (iii) using cross-spectra between Planck frequency maps. With the three different methods, we detect the tSZ-CIB cross-power spectrum at significance levels of (i) 6 σ\sigma, (ii) 3 σ\sigma, and (iii) 4 σ\sigma. We model the tSZ-CIB cross-correlation signature and compare predictions with the measurements. The amplitude of the cross-correlation relative to the fiducial model is AtSZCIB=1.2±0.3A_{\rm tSZ-CIB}= 1.2\pm0.3. This result is consistent with predictions for the tSZ-CIB cross-correlation assuming the best-fit cosmological model from Planck 2015 results along with the tSZ and CIB scaling relations.Comment: 18 pages, 16 figure
    corecore