| 1. |
- de Rojas, I., et al.
(författare)
-
Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores
- 2021
-
Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Genetic discoveries of Alzheimer’s disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer’s disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer’s disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer’s disease. © 2021, The Author(s).
|
|
| 2. |
|
|
| 3. |
- Meech, K. J., et al.
(författare)
-
EPOXI: Comet 103P/Hartley 2 Observations from a Worldwide Campaign
- 2011
-
Ingår i: Astrophysical Journal Letters. - London : IOP. - 2041-8213 .- 2041-8205. ; 734:L1, s. 1-9
-
Tidskriftsartikel (refereegranskat)abstract
- Earth- and space-based observations provide synergistic information for space mission encounters by providing data over longer timescales, at different wavelengths and using techniques that are impossible with an in situ flyby. We report here such observations in support of the EPOXI spacecraft flyby of comet 103P/Hartley 2. The nucleus is small and dark, and exhibited a very rapidly changing rotation period. Prior to the onset of activity, the period was ~16.4?hr. Starting in 2010 August the period changed from 16.6?hr to near 19?hr in December. With respect to dust composition, most volatiles and carbon and nitrogen isotope ratios, the comet is similar to other Jupiter-family comets. What is unusual is the dominance of CO 2 -driven activity near perihelion, which likely persists out to aphelion. Near perihelion the comet nucleus was surrounded by a large halo of water-ice grains that contributed significantly to the total water production.
|
|
| 4. |
- Elhai, M, et al.
(författare)
-
Outcomes of patients with systemic sclerosis treated with rituximab in contemporary practice: a prospective cohort study
- 2019
-
Ingår i: Annals of the rheumatic diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 78:7, s. 979-987
-
Tidskriftsartikel (refereegranskat)abstract
- To assess the safety and efficacy of rituximab in systemic sclerosis (SSc) in clinical practice.MethodsWe performed a prospective study including patients with SSc from the European Scleroderma Trials and Research (EUSTAR) network treated with rituximab and matched with untreated patients with SSc. The main outcomes measures were adverse events, skin fibrosis improvement, lung fibrosis worsening and steroids use among propensity score-matched patients treated or not with rituximab.Results254 patients were treated with rituximab, in 58% for lung and in 32% for skin involvement. After a median follow-up of 2 years, about 70% of the patients had no side effect. Comparison of treated patients with 9575 propensity-score matched patients showed that patients treated with rituximab were more likely to have skin fibrosis improvement (22.7 vs 14.03 events per 100 person-years; OR: 2.79 [1.47–5.32]; p=0.002). Treated patients did not have significantly different rates of decrease in forced vital capacity (FVC)>10% (OR: 1.03 [0.55–1.94]; p=0.93) nor in carbon monoxide diffusing capacity (DLCO) decrease. Patients having received rituximab were more prone to stop or decrease steroids (OR: 2.34 [1.56–3.53], p<0.0001). Patients treated concomitantly with mycophenolate mofetil had a trend for better outcomes as compared with patients receiving rituximab alone (delta FVC: 5.22 [0.83–9.62]; p=0.019 as compared with controls vs 3 [0.66–5.35]; p=0.012).ConclusionRituximab use was associated with a good safety profile in this large SSc-cohort. Significant change was observed on skin fibrosis, but not on lung. However, the limitation is the observational design. The potential stabilisation of lung fibrosis by rituximab has to be addressed by a randomised trial.
|
|
| 5. |
|
|
| 6. |
- Becker, M, et al.
(författare)
-
Predictors of disease worsening defined by progression of organ damage in diffuse systemic sclerosis: a European Scleroderma Trials and Research (EUSTAR) analysis
- 2019
-
Ingår i: Annals of the rheumatic diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 78:9, s. 1242-1248
-
Tidskriftsartikel (refereegranskat)abstract
- Mortality and worsening of organ function are desirable endpoints for clinical trials in systemic sclerosis (SSc). The aim of this study was to identify factors that allow enrichment of patients with these endpoints, in a population of patients from the European Scleroderma Trials and Research group database.MethodsInclusion criteria were diagnosis of diffuse SSc and follow-up over 12±3 months. Disease worsening/organ progression was fulfilled if any of the following events occurred: new renal crisis; decrease of lung or heart function; new echocardiography-suspected pulmonary hypertension or death. In total, 42 clinical parameters were chosen as predictors for the analysis by using (1) imputation of missing data on the basis of multivariate imputation and (2) least absolute shrinkage and selection operator regression.ResultsOf 1451 patients meeting the inclusion criteria, 706 had complete data on outcome parameters and were included in the analysis. Of the 42 outcome predictors, eight remained in the final regression model. There was substantial evidence for a strong association between disease progression and age, active digital ulcer (DU), lung fibrosis, muscle weakness and elevated C-reactive protein (CRP) level. Active DU, CRP elevation, lung fibrosis and muscle weakness were also associated with a significantly shorter time to disease progression. A bootstrap validation step with 10 000 repetitions successfully validated the model.ConclusionsThe use of the predictive factors presented here could enable cohort enrichment with patients at risk for overall disease worsening in SSc clinical trials.
|
|
| 7. |
- Govaere, O., et al.
(författare)
-
Macrophage scavenger receptor 1 mediates lipid-induced inflammation in non-alcoholic fatty liver disease
- 2022
-
Ingår i: Journal of Hepatology. - : Elsevier BV. - 0168-8278 .- 1600-0641. ; 76:5, s. 1001-1012
-
Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Obesity-associated inflammation is a key player in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). However, the role of macrophage scavenger receptor 1 (MSR1, CD204) remains incompletely understood. Methods: A total of 170 NAFLD liver biopsies were processed for transcriptomic analysis and correlated with clinicopathological features. Msr1-/- and wild-type mice were subjected to a 16-week high-fat and high-cholesterol diet. Mice and ex vivo human liver slices were treated with a monoclonal antibody against MSR1. Genetic susceptibility was assessed using genome-wide association study data from 1,483 patients with NAFLD and 430,101 participants of the UK Biobank. Results: MSR1 expression was associated with the occurrence of hepatic lipid-laden foamy macrophages and correlated with the degree of steatosis and steatohepatitis in patients with NAFLD. Mice lacking Msr1 were protected against diet-induced metabolic disorder, showing fewer hepatic foamy macrophages, less hepatic inflammation, improved dyslipidaemia and glucose tolerance, and altered hepatic lipid metabolism. Upon induction by saturated fatty acids, MSR1 induced a pro-inflammatory response via the JNK signalling pathway. In vitro blockade of the receptor prevented the accumulation of lipids in primary macrophages which inhibited the switch towards a pro-inflammatory phenotype and the release of cytokines such as TNF-ɑ. Targeting MSR1 using monoclonal antibody therapy in an obesity-associated NAFLD mouse model and human liver slices resulted in the prevention of foamy macrophage formation and inflammation. Moreover, we identified that rs41505344, a polymorphism in the upstream transcriptional region of MSR1, was associated with altered serum triglycerides and aspartate aminotransferase levels in a cohort of over 400,000 patients. Conclusions: Taken together, our data suggest that MSR1 plays a critical role in lipid-induced inflammation and could thus be a potential therapeutic target for the treatment of NAFLD. Lay summary: Non-alcoholic fatty liver disease (NAFLD) is a chronic disease primarily caused by excessive consumption of fat and sugar combined with a lack of exercise or a sedentary lifestyle. Herein, we show that the macrophage scavenger receptor MSR1, an innate immune receptor, mediates lipid uptake and accumulation in Kupffer cells, resulting in liver inflammation and thereby promoting the progression of NAFLD in humans and mice. © 2021 The Authors
|
|
| 8. |
- Pellegrinelli, V, et al.
(författare)
-
Dysregulation of macrophage PEPD in obesity determines adipose tissue fibro-inflammation and insulin resistance
- 2022
-
Ingår i: Nature Metabolism. - : Springer Nature. - 2522-5812. ; 4:4, s. 476-
-
Tidskriftsartikel (refereegranskat)abstract
- Resulting from impaired collagen turnover, fibrosis is a hallmark of adipose tissue (AT) dysfunction and obesity-associated insulin resistance (IR). Prolidase, also known as peptidase D (PEPD), plays a vital role in collagen turnover by degrading proline-containing dipeptides but its specific functional relevance in AT is unknown. Here we show that in human and mouse obesity, PEPD expression and activity decrease in AT, and PEPD is released into the systemic circulation, which promotes fibrosis and AT IR. Loss of the enzymatic function of PEPD by genetic ablation or pharmacological inhibition causes AT fibrosis in mice. In addition to its intracellular enzymatic role, secreted extracellular PEPD protein enhances macrophage and adipocyte fibro-inflammatory responses via EGFR signalling, thereby promoting AT fibrosis and IR. We further show that decreased prolidase activity is coupled with increased systemic levels of PEPD that act as a pathogenic trigger of AT fibrosis and IR. Thus, PEPD produced by macrophages might serve as a biomarker of AT fibro-inflammation and could represent a therapeutic target for AT fibrosis and obesity-associated IR and type 2 diabetes. Obesity-associated AT fibro-inflammation and metabolic disturbances are linked to PEPD activity and PEPD extracellular levels.
|
|
| 9. |
- Govoni, F., et al.
(författare)
-
A radio ridge connecting two galaxy clusters in a filament of the cosmic web
- 2019
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 364:6444, s. 981-984
-
Tidskriftsartikel (refereegranskat)abstract
- Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intracluster gas. We observed a ridge of radio emission connecting the merging galaxy clusters Abell 0399 and Abell 0401 with the Low-Frequency Array (LOFAR) telescope network at 140 megahertz. This emission requires a population of relativistic electrons and a magnetic field located in a filament between the two galaxy clusters. We performed simulations to show that a volume-filling distribution of weak shocks may reaccelerate a preexisting population of relativistic particles, producing emission at radio wavelengths that illuminates the magnetic ridge.
|
|
| 10. |
- Chyz̊y, K.T., et al.
(författare)
-
LOFAR MSSS: Flattening low-frequency radio continuum spectra of nearby galaxies
- 2018
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 619
-
Tidskriftsartikel (refereegranskat)abstract
- Aims. The shape of low-frequency radio continuum spectra of normal galaxies is not well understood, the key question being the role of physical processes such as thermal absorption in shaping them. In this work we take advantage of the LOFAR Multifrequency Snapshot Sky Survey (MSSS) to investigate such spectra for a large sample of nearby star-forming galaxies. Methods. Using the measured 150 MHz flux densities from the LOFAR MSSS survey and literature flux densities at various frequencies we have obtained integrated radio spectra for 106 galaxies characterised by different morphology and star formation rate. The spectra are explained through the use of a three-dimensional model of galaxy radio emission, and radiation transfer dependent on the galaxy viewing angle and absorption processes. Results. Our galaxies' spectra are generally flatter at lower compared to higher frequencies: the median spectral index αlow measured between ≈ 50 MHz and 1.5 GHz is -0.57 ± 0.01 while the high-frequency one αhigh, calculated between 1.3 GHz and 5 GHz, is -0.77 ± 0.03. As there is no tendency for the highly inclined galaxies to have more flattened low-frequency spectra, we argue that the observed flattening is not due to thermal absorption, contradicting the suggestion of Israel & Mahoney (1990, ApJ, 352, 30). According to our modelled radio maps for M 51-like galaxies, the free-free absorption effects can be seen only below 30 MHz and in the global spectra just below 20 MHz, while in the spectra of starburst galaxies, like M 82, the flattening due to absorption is instead visible up to higher frequencies of about 150 MHz. Starbursts are however scarce in the local Universe, in accordance with the weak spectral curvature seen in the galaxies of our sample. Locally, within galactic disks, the absorption effects are distinctly visible in M 51-like galaxies as spectral flattening around 100-200 MHz in the face-on objects, and as turnovers in the edge-on ones, while in M 82-like galaxies there are strong turnovers at frequencies above 700 MHz, regardless of viewing angle. Conclusions. Our modelling of galaxy spectra suggests that the weak spectral flattening observed in the nearby galaxies studied here results principally from synchrotron spectral curvature due to cosmic ray energy losses and propagation effects. We predict much stronger effects of thermal absorption in more distant galaxies with high star formation rates. Some influence exerted by the Milky Way's foreground on the spectra of all external galaxies is also expected at very low frequencies.
|
|
| 11. |
- Heald, G., et al.
(författare)
-
Magnetism science with the square kilometre array
- 2020
-
Ingår i: Galaxies. - : MDPI AG. - 2075-4434. ; 8:8
-
Tidskriftsartikel (refereegranskat)abstract
- The Square Kilometre Array (SKA) will answer fundamental questions about the origin, evolution, properties, and influence of magnetic fields throughout the Universe. Magnetic fields can illuminate and influence phenomena as diverse as star formation, galactic dynamics, fast radio bursts, active galactic nuclei, large-scale structure, and dark matter annihilation. Preparations for the SKA are swiftly continuing worldwide, and the community is making tremendous observational progress in the field of cosmic magnetism using data from a powerful international suite of SKA pathfinder and precursor telescopes. In this contribution, we revisit community plans for magnetism research using the SKA, in light of these recent rapid developments. We focus in particular on the impact that new radio telescope instrumentation is generating, thus advancing our understanding of key SKA magnetism science areas, as well as the new techniques that are required for processing and interpreting the data. We discuss these recent developments in the context of the ultimate scientific goals for the SKA era.
|
|
| 12. |
- O'Sullivan, S. P., et al.
(författare)
-
The Faraday Rotation Measure Grid of the LOFAR Two-metre Sky Survey: Data Release 2
- 2023
-
Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 519:4, s. 5723-5742
-
Tidskriftsartikel (refereegranskat)abstract
- A Faraday rotation measure (RM) catalogue, or RM Grid, is a valuable resource for the study of cosmic magnetism. Using the second data release (DR2) from the LOFAR Two-metre Sky Survey (LoTSS), we have produced a catalogue of 2461 extragalactic high-precision RM values across 5720 deg(2) of sky (corresponding to a polarized source areal number density of similar to 0.43 deg(-2)). The linear polarization and RM properties were derived using RM synthesis from the Stokes Q and U channel images at an angular resolution of 20 arcsec across a frequency range of 120 to 168 MHz with a channel bandwidth of 97.6 kHz. The fraction of total intensity sources (>1 mJy beam(-1)) found to be polarized was similar to 0.2 percent. The median detection threshold was 0.6 mJy beam(-1) (8 sigma(QU)), with a median RM uncertainty of 0.06 rad m(-2) (although a systematic uncertainty of up to 0.3 radm(-2) is possible, after the ionosphere RM correction). The median degree of polarization of the detected sources is 1.8 percent, with a range of 0.05 percent to 31 percent. Comparisons with cm-wavelength RMs indicate minimal amounts of Faraday complexity in the LoTSS detections, making them ideal sources for RM Grid studies. Host galaxy identifications were obtained for 88 percent of the sources, along with redshifts for 79 percent (both photometric and spectroscopic), with the median redshift being 0.6. The focus of the current catalogue was on reliability rather than completeness, and we expect future versions of the LoTSS RM Grid to have a higher areal number density. In addition, 25 pulsars were identified, mainly through their high degrees of linear polarization.
|
|
| 13. |
- O'Sullivan, Shane P., et al.
(författare)
-
The intergalactic magnetic field probed by a giant radio galaxy
- 2019
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 622
-
Forskningsöversikt (refereegranskat)abstract
- Cosmological simulations predict that an intergalactic magnetic field (IGMF) pervades the large scale structure (LSS) of the Universe. Measuring the IGMF is important to determine its origin (i.e. primordial or otherwise). Using data from the LOFAR Two Metre Sky Survey (LoTSS), we present the Faraday rotation measure (RM) and depolarisation properties of the giant radio galaxy J1235+5317, at a redshift of z = 0.34 and 3.38 Mpc in size. We find a mean RM difference between the lobes of 2.5 ±0.1 rad m -2 , in addition to small scale RM variations of ∼0.1 rad m -2 . From a catalogue of LSS filaments based on optical spectroscopic observations in the local universe, we find an excess of filaments intersecting the line of sight to only one of the lobes. Associating the entire RM difference to these LSS filaments leads to a gas density-weighted IGMF strength of ∼0.3 μG. However, direct comparison with cosmological simulations of the RM contribution from LSS filaments gives a low probability (∼5%) for an RM contribution as large as 2.5 rad m -2 , for the case of IGMF strengths of 10-50 nG. It is likely that variations in the RM from the Milky Way (on 11′ scales) contribute significantly to the mean RM difference, and a denser RM grid is required to better constrain this contribution. In general, this work demonstrates the potential of the LOFAR telescope to probe the weak signature of the IGMF. Future studies, with thousands of sources with high accuracy RMs from LoTSS, will enable more stringent constraints on the nature of the IGMF.
|
|
| 14. |
- Van Eck, C.L., et al.
(författare)
-
Polarized point sources in the LOFAR Two-meter Sky Survey: A preliminary catalog
- 2018
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 613
-
Forskningsöversikt (refereegranskat)abstract
- The polarization properties of radio sources at very low frequencies (<200 MHz) have not been widely measured, but the new generation of low-frequency radio telescopes, including the Low Frequency Array (LOFAR: a Square Kilometre Array Low pathfinder), now gives us the opportunity to investigate these properties. In this paper, we report on the preliminary development of a data reduction pipeline to carry out polarization processing and Faraday tomography for data from the LOFAR Two-meter Sky Survey (LOTSS) and present the results of this pipeline from the LOTSS preliminary data release region (10h45m–15h30m right ascension, 45°–57° declination, 570 square degrees). We have produced a catalog of 92 polarized radio sources at 150 MHz at 4.′3 resolution and 1 mJy rms sensitivity, which is the largest catalog of polarized sources at such low frequencies. We estimate a lower limit to the polarized source surface density at 150 MHz, with our resolution and sensitivity, of 1 source per 6.2 square degrees. We find that our Faraday depth measurements are in agreement with previous measurements and have significantly smaller errors. Most of our sources show significant depolarization compared to 1.4 GHz, but there is a small population of sources with low depolarization indicating that their polarized emission is highly localized in Faraday depth. We predict that an extension of this work to the full LOTSS data would detect at least 3400 polarized sources using the same methods, and probably considerably more with improved data processing.
|
|
| 15. |
- Amendola, L., et al.
(författare)
-
Cosmology and fundamental physics with the Euclid satellite
- 2018
-
Ingår i: Living Reviews in Relativity. - : Springer. - 1433-8351 .- 2367-3613. ; 21:1
-
Tidskriftsartikel (refereegranskat)abstract
- Euclid is a European Space Agency medium-class mission selected for launch in 2020 within the cosmic vision 2015–2025 program. The main goal of Euclid is to understand the origin of the accelerated expansion of the universe. Euclid will explore the expansion history of the universe and the evolution of cosmic structures by measuring shapes and red-shifts of galaxies as well as the distribution of clusters of galaxies over a large fraction of the sky. Although the main driver for Euclid is the nature of dark energy, Euclid science covers a vast range of topics, from cosmology to galaxy evolution to planetary research. In this review we focus on cosmology and fundamental physics, with a strong emphasis on science beyond the current standard models. We discuss five broad topics: dark energy and modified gravity, dark matter, initial conditions, basic assumptions and questions of methodology in the data analysis. This review has been planned and carried out within Euclid’s Theory Working Group and is meant to provide a guide to the scientific themes that will underlie the activity of the group during the preparation of the Euclid mission.
|
|
| 16. |
- Oppermann, N., et al.
(författare)
-
Estimating extragalactic Faraday rotation
- 2015
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 575
-
Tidskriftsartikel (refereegranskat)abstract
- Observations of Faraday rotation for extragalactic sources probe magnetic fields both inside and outside the Milky Way. Building on our earlier estimate of the Galactic contribution, we set out to estimate the extragalactic contributions. We discuss the problems involved; in particular, we point out that taking the difference between the observed values and the Galactic foreground reconstruction is not a good estimate for the extragalactic contributions. We point out a degeneracy between the contributions to the observed values due to extragalactic magnetic fields and observational noise and comment on the dangers of over-interpreting an estimate without taking into account its uncertainty information. To overcome these difficulties, we develop an extended reconstruction algorithm based on the assumption that the observational uncertainties are accurately described for a subset of the data, which can overcome the degeneracy with the extragalactic contributions. We present a probabilistic derivation of the algorithm and demonstrate its performance using a simulation, yielding a high quality reconstruction of the Galactic Faraday rotation foreground, a precise estimate of the typical extragalactic contribution, and a well-defined probabilistic description of the extragalactic contribution for each data point. We then apply this reconstruction technique to a catalog of Faraday rotation observations for extragalactic sources. The analysis is done for several different scenarios, for which we consider the error bars of different subsets of the data to accurately describe the observational uncertainties. By comparing the results, we argue that a split that singles out only data near the Galactic poles is the most robust approach. We find that the dispersion of extragalactic contributions to observed Faraday depths is most likely lower than 7 rad/m(2), in agreement with earlier results, and that the extragalactic contribution to an individual data point is poorly constrained by the data in most cases.
|
|
| 17. |
- Vacca, V., et al.
(författare)
-
Statistical methods for the analysis of rotation measure grids in large scale structures in the SKA era
- 2015
-
Ingår i: Proceedings of Science. - 1824-8039. ; 9-13-June-2014
-
Konferensbidrag (refereegranskat)abstract
- Determining magnetic field properties in different environments of the cosmic large-scale structure as well as their evolution over redshift is a fundamental step toward uncovering the origin of cosmic magnetic fields. Radio observations permit the study of extragalactic magnetic fields via measurements of the Faraday depth of extragalactic radio sources. Our aim is to investigate how much different extragalactic environments contribute to the Faraday depth variance of these sources. We develop a Bayesian algorithm to distinguish statistically Faraday depth variance contributions intrinsic to the source from those due to the medium between the source and the observer. In our algorithm the Galactic foreground and the measurement noise are taken into account as the uncertainty correlations of the galactic model. Additionally, our algorithm allows for the investigation of possible redshift evolution of the extragalactic contribution. This work presents the derivation of the algorithm and tests performed on mock observations. With cosmic magnetism being one of the key science projects of the new generation of radio interferometers we have made predictions for the algorithm's performance on data from the next generation of radio interferometers. Applications to real data are left for future work.
|
|
| 18. |
- Vacca, V., et al.
(författare)
-
Using rotation measure grids to detect cosmological magnetic fields: A Bayesian approach
- 2016
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 591, s. Art. no. A13-
-
Tidskriftsartikel (refereegranskat)abstract
- Determining magnetic field properties in different environments of the cosmic large-scale structure as well as their evolution over redshift is a fundamental step toward uncovering the origin of cosmic magnetic fields. Radio observations permit the study of extragalactic magnetic fields via measurements of the Faraday depth of extragalactic radio sources. Our aim is to investigate how much different extragalactic environments contribute to the Faraday depth variance of these sources. We develop a Bayesian algorithm to distinguish statistically Faraday depth variance contributions intrinsic to the source from those due to the medium between the source and the observer. In our algorithm the Galactic foreground and measurement noise are taken into account as the uncertainty correlations of the Galactic model. Additionally, our algorithm allows for the investigation of possible redshift evolution of the extragalactic contribution. This work presents the derivation of the algorithm and tests performed on mock observations. Because cosmic magnetism is one of the key science projects of the new generation of radio interferometers, we have predicted the performance of our algorithm on mock data collected with these instruments. According to our tests, high-quality catalogs of a few thousands of sources should already enable us to investigate magnetic fields in the cosmic structure.
|
|
| 19. |
- Azzu, V., et al.
(författare)
-
Suppression of insulin-induced gene 1 (INSIG1) function promotes hepatic lipid remodelling and restrains NASH progression
- 2021
-
Ingår i: Molecular Metabolism. - : Elsevier BV. - 2212-8778. ; 48
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Non-alcoholic fatty liver disease (NAFLD) is a silent pandemic associated with obesity and the metabolic syndrome, and also increases cardiovascular- and cirrhosis-related morbidity and mortality. A complete understanding of adaptive compensatory metabolic programmes that modulate non-alcoholic steatohepatitis (NASH) progression is lacking. Methods and results: Transcriptomic analysis of liver biopsies in patients with NASH revealed that NASH progression is associated with rewiring of metabolic pathways, including upregulation of de novo lipid/cholesterol synthesis and fatty acid remodelling. The modulation of these metabolic programmes was achieved by activating sterol regulatory element-binding protein (SREBP) transcriptional networks; however, it is still debated whether, in the context of NASH, activation of SREBPs acts as a pathogenic driver of lipotoxicity, or rather promotes the biosynthesis of protective lipids that buffer excessive lipid accumulation, preventing inflammation and fibrosis. To elucidate the pathophysiological role of SCAP/SREBP in NASH and wound-healing response, we used an Insig1 deficient (with hyper-efficient SREBPs) murine model challenged with a NASH-inducing diet. Despite enhanced lipid and cholesterol biosynthesis, Insig1 KO mice had similar systemic metabolism and insulin sensitivity to Het/WT littermates. Moreover, activating SREBPs resulted in remodelling the lipidome, decreased hepatocellular damage, and improved wound-healing responses. Conclusions: Our study provides actionable knowledge about the pathways and mechanisms involved in NAFLD pathogenesis, which may prove useful for developing new therapeutic strategies. Our results also suggest that the SCAP/SREBP/INSIG1 trio governs transcriptional programmes aimed at protecting the liver from lipotoxic insults in NASH. (C) 2021 Published by Elsevier GmbH. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
- Boschini, M. J., et al.
(författare)
-
Solution of Heliospheric Propagation : Unveiling the Local Interstellar Spectra of Cosmic-ray Species
- 2017
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 840:2
-
Tidskriftsartikel (refereegranskat)abstract
- Local interstellar spectra (LIS) for protons, helium, and antiprotons are built using the most recent experimental results combined with state-of-the-art models for propagation in the Galaxy and heliosphere. Two propagation packages, GALPROP and HelMod, are combined to provide a single framework that is run to reproduce direct measurements of cosmic-ray (CR) species at different modulation levels and at both polarities of the solar magnetic field. To do so in a self-consistent way, an iterative procedure was developed, where the GALPROP LIS output is fed into HelMod, providing modulated spectra for specific time periods of selected experiments to compare with the data; the HelMod parameter optimization is performed at this stage and looped back to adjust the LIS using the new GALPROP run. The parameters were tuned with the maximum likelihood procedure using an extensive data set of proton spectra from 1997 to 2015. The proposed LIS accommodate both the low-energy interstellar CR spectra measured by Voyager 1 and the high-energy observations by BESS, Pamela, AMS-01, and AMS-02 made from the balloons and near-Earth payloads; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The found solution is in a good agreement with proton, helium, and antiproton data by AMS-02, BESS, and PAMELA in the whole energy range.
|
|
| 23. |
|
|
| 24. |
|
|
| 25. |
- Boschini, M. J., et al.
(författare)
-
A Hint of a Low-energy Excess in Cosmic-Ray Fluorine
- 2022
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 925:2
-
Tidskriftsartikel (refereegranskat)abstract
- Since its launch, the Alpha Magnetic Spectrometer–02 (AMS-02) has delivered outstanding quality measurements of the spectra of cosmic-ray (CR) species (, e±) and nuclei (H–O, Ne, Mg, Si, Fe), which resulted in a number of breakthroughs. The most recent AMS-02 result is the measurement of the spectrum of CR fluorine up to ∼2 TV. Given its very low solar system abundance, fluorine in CRs is thought to be mostly secondary, produced in fragmentations of heavier species, predominantly Ne, Mg, and Si. Similar to the best-measured secondary-to-primary boron to carbon nuclei ratio that is widely used to study the origin and propagation of CR species, the precise fluorine data would allow the origin of Si-group nuclei to be studied independently. Meanwhile, the secondary origin of CR fluorine has never been tested in a wide energy range due to the lack of accurate CR data. In this paper, we use the first ever precise measurements of the fluorine spectrum by AMS-02 together with ACE-CRIS and Voyager 1 data to actually test this paradigm. Our detailed modeling shows an excess below 10 GV in the fluorine spectrum that may hint at a primary fluorine component. We also provide an updated local interstellar spectrum (LIS) of fluorine in the rigidity range from a few MV to ∼2 TV. Our calculations employ the self-consistent GalProp–HelMod framework that has proved to be a reliable tool in deriving the LIS of CR and e−, and nuclei Z ≤ 28.
|
|
| 26. |
- Boschini, M. J., et al.
(författare)
-
Deciphering the Local Interstellar Spectra of Primary Cosmic-Ray Species with HELMOD
- 2018
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 858:1
-
Tidskriftsartikel (refereegranskat)abstract
- Local interstellar spectra (LIS) of primary cosmic ray (CR) nuclei, such as helium, oxygen, and mostly primary carbon are derived for the rigidity range from 10 MV to similar to 200 TV using the most recent experimental results combined with the state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HELMOD, are combined into a single framework that is used to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. The developed iterative maximum-likelihood method uses GALPROP-predicted LIS as input to HELMOD, which provides the modulated spectra for specific time periods of the selected experiments for model-data comparison. The interstellar and heliospheric propagation parameters derived in this study are consistent with our prior analyses using the same methodology for propagation of CR protons, helium, antiprotons, and electrons. The resulting LIS accommodate a variety of measurements made in the local interstellar space (Voyager 1) and deep inside the heliosphere at low (ACE/CRIS, HEAO-3) and high energies (PAMELA, AMS-02).
|
|
| 27. |
- Boschini, M. J., et al.
(författare)
-
HelMod in the Works : From Direct Observations to the Local Interstellar Spectrum of Cosmic-Ray Electrons
- 2018
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 854:2
-
Tidskriftsartikel (refereegranskat)abstract
- The local interstellar spectrum (LIS) of cosmic-ray (CR) electrons for the energy range 1 MeV to 1 TeV is derived using the most recent experimental results combined with the state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HELMOD, are combined to provide a single framework that is run to reproduce direct measurements of CR species at different modulation levels, and at both polarities of the solar magnetic field. An iterative maximum-likelihood method is developed that uses GALPROP-predicted LIS as input to HELMOD, which provides the modulated spectra for specific time periods of the selected experiments for model-data comparison. The optimized HelMod parameters are then used to adjust GALPROP parameters to predict a refined LIS with the procedure repeated subject to a convergence criterion. The parameter optimization uses an extensive data set of proton spectra from 1997 to 2015. The proposed CR electron LIS accommodates both the low-energy interstellar spectra measured by Voyager 1 as well as the high-energy observations by PAMELA and AMS-02 that are made deep in the heliosphere; it also accounts for Ulysses counting rate features measured out of the ecliptic plane. The interstellar and heliospheric propagation parameters derived in this study agree well with our earlier results for CR protons, helium nuclei, and anti-protons propagation and LIS obtained in the same framework.
|
|
| 28. |
- Boschini, M. J., et al.
(författare)
-
Spectra of Cosmic-Ray Sodium and Aluminum and Unexpected Aluminum Excess
- 2022
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 933:2
-
Tidskriftsartikel (refereegranskat)abstract
- Since its launch, the Alpha Magnetic Spectrometer-02 (AMS-02) has delivered outstanding quality measurements of the spectra of cosmic-ray (CR) species, , e±, and nuclei (H–Si, Fe), which resulted in a number of breakthroughs. The most recent AMS-02 result is the measurement of the spectra of CR sodium and aluminum up to ∼2 TV. Given their low solar system abundances, a significant fraction of each element is produced in fragmentations of heavier species, predominantly Ne, Mg, and Si. In this paper, we use precise measurements of the sodium and aluminum spectra by AMS-02 together with ACE-CRIS and Voyager 1 data to test their origin. We show that the sodium spectrum agrees well with the predictions made with the GalProp-HelMod framework, while the aluminum spectrum shows a significant excess in the rigidity range from 2–7 GV. In this context, we discuss the origin of other low-energy excesses in Li, F, and Fe found earlier. The observed excesses in Li, F, and Al appear to be consistent with the local Wolf-Rayet stars hypothesis, invoked to reproduce anomalous 22Ne/20Ne, 12C/16O, and 58Fe/56Fe ratios in CRs, while excess in Fe is likely connected with a past supernova activity in the solar neighborhood. We also provide updated local interstellar spectra (LIS) of sodium and aluminum in the rigidity range from a few megavolts to ∼2 TV. Our calculations employ the self-consistent GalProp-HelMod framework, which has proved to be a reliable tool in deriving the LIS of CR , e−, and nuclei Z ≤ 28.
|
|
| 29. |
- Indriolo, Nick, et al.
(författare)
-
SOFIA/EXES observations of water absorption in the protostar AFGL 2591 at high spectral resolution
- 2015
-
Ingår i: Astrophysical Journal Letters. - 2041-8213. ; 802:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present high spectral resolution (similar to 3 km s(-1)) observations of the nu(2) ro-vibrational band of H2O in the 6.086-6.135 mu m range toward the massive protostar AFGL 2591 using the Echelon-Cross-Echelle Spectrograph (EXES) on the Stratospheric Observatory for Infrared Astronomy (SOFIA). Ten absorption features are detected in total, with seven caused by transitions in the nu(2) band of H2O, two by transitions in the first vibrationally excited nu(2) band of H2O, and one by a transition in the nu(2) band of (H2O)-O-18. Among the detected transitions is the nu(2) 1(1,1)-0(0,0) line that probes the lowest-lying rotational level of para-H2O. The stronger transitions appear to be optically thick, but reach maximum absorption at a depth of about 25%, suggesting that the background source is only partially covered by the absorbing gas or that the absorption arises within the 6 mu m emitting photosphere. Assuming a covering fraction of 25%, the H2O column density and rotational temperature that best fit the observed absorption lines are N(H2O) = (1.3 +/- 0.3) x 10(19) cm(-2) and T = 640 +/- 80 K.
|
|
| 30. |
- O'Sullivan, Shane P., et al.
(författare)
-
Untangling cosmic magnetic fields: Faraday tomography at metre wavelengths with LOFAR
- 2018
-
Ingår i: Galaxies. - : MDPI AG. - 2075-4434. ; 6:4
-
Tidskriftsartikel (refereegranskat)abstract
- The technique of Faraday tomography is a key tool for the study ofmagnetised plasmas in the new era of broadband radio-polarisation observations. In particular, observations at metre wavelengths provide significantly better Faraday depth accuracies compared to traditional centimetre-wavelength observations. However, the effect of Faraday depolarisationmakes the polarised signal very challenging to detect at metre wavelengths (MHz frequencies). In this work, Faraday tomography is used to characterise the Faraday rotation properties of polarised sources found in data from the LOFAR Two-Metre Sky Survey (LoTSS). Of the 76 extragalactic polarised sources analysed here, we find that all host a radio-loud AGN (Active Galactic Nucleus). The majority of the sources (~64%) are large FRII radio galaxies with a median projected linear size of 710 kpc and median radio luminosity at 144 MHz of 4 × 1026 W Hz-1 (with ~13% of all sources having a linear size > 1 Mpc). In several cases, both hotspots are detected in polarisation at an angular resolution of ~20'. One such case allowed a study of intergalactic magnetic fields on scales of 3.4 Mpc. Other detected source types include an FRI radio galaxy and at least eight blazars. Most sources display simple Faraday spectra, but we highlight one blazar that displays a complex Faraday spectrum, with two close peaks in the Faraday dispersion function.
|
|
| 31. |
- Ruiz, N. Herrera, et al.
(författare)
-
Lofar deep fields: Probing a broader population of polarized radio galaxies in elais-n1
- 2021
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 648
-
Tidskriftsartikel (refereegranskat)abstract
- We present deep polarimetric observations of the European Large Area ISO Survey-North 1 (ELAIS-N1) field using the Low Frequency Array (LOFAR) at 114.9-177.4 MHz. The ELAIS-N1 field is part of the LOFAR Two-metre Sky Survey deep fields data release I. For six eight-hour observing epochs, we align the polarization angles and stack the 20″-resolution Stokes Q, U-parameter data cubes. This produces a 16 deg2 image with 1σQU sensitivity of 26 μJy beam-1 in the central area. In this paper, we demonstrate the feasibility of the stacking technique, and we generate a catalog of polarized sources in ELAIS-N1 and their associated Faraday rotation measures (RMs). While in a single-epoch observation we detect three polarized sources, this number increases by a factor of about three when we consider the stacked data, with a total of ten sources. This yields a surface density of polarized sources of one per 1.6 deg2. The Stokes I images of three of the ten detected polarized sources have morphologies resembling those of FR I radio galaxies. This represents a greater fraction of this type of source than previously found, which suggests that more sensitive observations may help with their detection.
|
|
| 32. |
- Ryde, N., et al.
(författare)
-
Evolved Stars with Complex Atmospheres - the High Spectral Resolution, mid-IR View
- 2015
-
Ingår i: Why galaxies care about AGB stars III. - : ASTRONOMICAL SOC PACIFIC. - 9781583818794 - 9781583818787 ; , s. 67-71
-
Konferensbidrag (refereegranskat)abstract
- The physical structures of the outer atmospheres of red giants are not known. They are certainly complex, and a range of recent observations are showing that we need to embrace non-classical model atmospheres to interpret these regions. This region's properties are of importance, not the least for an understanding of the mass-loss mechanism for these stars. Here we present observational constraints on the outer regions of red giants, based on mid-IR, high spectral resolution spectra. We also discuss possible non-LTE effects and highlight a new non-LTE code that will be used to analyse the spectra of these atmospheric layers. We conclude by mentioning our new SOFIA/EXES observations of red giants at 67 mu m, where the vibration-rotation lines of water vapour can be detected and spectrally resolved for the first time.
|
|
| 33. |
- Šnidariać, Iva, et al.
(författare)
-
LOFAR Deep Fields: Probing faint Galactic polarised emission in ELAIS-N1
- 2023
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 674
-
Tidskriftsartikel (refereegranskat)abstract
- We present the first deep polarimetric study of Galactic synchrotron emission at low radio frequencies. Our study is based on 21 observations of the European Large Area Infrared Space Observatory Survey-North 1 (ELAIS-N1) field using the Low-Frequency Array (LOFAR) at frequencies from 114.9 to 177.4 MHz. These data are a part of the LOFAR Two-metre Sky Survey Deep Fields Data Release 1. We used very low-resolution (4.3') Stokes QU data cubes of this release. We applied rotation measure (RM) synthesis to decompose the distribution of polarised structures in Faraday depth, and cross-correlation RM synthesis to align different observations in Faraday depth. We stacked images of about 150 h of the ELAIS-N1 observations to produce the deepest Faraday cube at low radio frequencies to date, tailored to studies of Galactic synchrotron emission and the intervening magneto-ionic interstellar medium. This Faraday cube covers ∼36 deg2 of the sky and has a noise of 27 μJy PSF-1 RMSF-1 in polarised intensity. This is an improvement in noise by a factor of approximately the square root of the number of stacked data cubes (√20), as expected, compared to the one in a single data cube based on five-to-eight-hour observations. We detect a faint component of diffuse polarised emission in the stacked cube, which was not detected previously. Additionally, we verify the reliability of the ionospheric Faraday rotation corrections estimated from the satellite-based total electron content measurements to be of ∼0.05 Cyrillic small letter GHEad m-2. We also demonstrate that diffuse polarised emission itself can be used to account for the relative ionospheric Faraday rotation corrections with respect to a reference observation.
|
|
| 34. |
|
|
| 35. |
|
|
| 36. |
- Anstee, Quentin M., et al.
(författare)
-
Genome-wide association study of non-alcoholic fatty liver and steatohepatitis in a histologically-characterised cohort
- 2020
-
Ingår i: Journal of Hepatology. - : Elsevier. - 0168-8278 .- 1600-0641. ; 73:3, s. 505-515
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Genetic factors associated with non-alcoholic fatty liver disease (NAFLD) remain incompletely understood. To date, most GWAS studies have adopted radiologically assessed hepatic triglyceride content as reference phenotype and so cannot address steatohepatitis or fibrosis. We describe a genome-wide association study (GWAS) encompassing the full spectrum of histologically characterized NAFLD.METHODS: The GWAS involved 1483 European NAFLD cases and 17781 genetically-matched population controls. A replication cohort of 559 NAFLD cases and 945 controls was genotyped to confirm signals showing genome-wide or close to genome-wide significance.RESULTS: Case-control analysis identified signals showing p-values ≤ 5 x 10-8 at four locations (chromosome (chr) 2 GCKR/C2ORF16; chr4 HSD17B13; chr19 TM6SF2; chr22 PNPLA3) together with two other signals with p<1 x10-7 (chr1 near LEPR and chr8 near IDO2/TC1). Case-only analysis of quantitative traits steatosis, disease activity score, NAS and fibrosis showed that the PNPLA3 signal (rs738409) was genome-wide significantly associated with steatosis, fibrosis and NAS score and identified a new signal (PYGO1 rs62021874) with close to genome-wide significance for steatosis (p=8.2 x 10-8). Subgroup case-control analysis for NASH confirmed the PNPLA3 signal. The chr1 LEPR SNP also showed genome-wide significance for this phenotype. Considering the subgroup with advanced fibrosis (≥F3), the signals on chromosomes 2, 19 and 22 remained genome-wide significant. With the exception of GCKR/C2ORF16, the genome-wide significant signals replicated.CONCLUSIONS: This study confirms PNPLA3 as a risk factor for the full histological spectrum of NAFLD at genome-wide significance levels, with important contributions from TM6SF2 and HSD17B13. PYGO1 is a novel steatosis modifier, suggesting relevance of Wnt signalling pathways in NAFLD pathogenesis.
|
|
| 37. |
|
|
| 38. |
|
|
| 39. |
|
|
| 40. |
- Carretti, Ettore, et al.
(författare)
-
Magnetic field strength in cosmic web filaments
- 2022
-
Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 512:1, s. 945-959
-
Tidskriftsartikel (refereegranskat)abstract
- We used the rotation measure (RM) catalogue derived from the LOFAR Two-metre Sky Survey Data Release 2 (LoTSS DR2) at 144MHz to measure the evolution with redshift of the extragalactic RM (RRM: Residual RM) and the polarization fraction (p) of sources in low-density environments. We also measured the same at 1.4 GHz by cross-matching with the NRAO VLA Sky Survey RM catalogue. We find that RRM versus redshift is flat at 144 MHz, but, once redshift-corrected, it shows evolution at high significance. Also, p evolves with redshift with a decrement by a factor of similar to 8 at z similar to 2. Comparing the 144-MHz and 1.4-GHz data, we find that the observed RRM and p are most likely to have an origin local to the source at 1.4 GHz, while a cosmic web filament origin is favoured at 144 MHz. If we attribute the entire signal to filaments, we infer a mean rest-frame RRM per filament of RRM0,f = 0.71 +/- 0.07 rad m(-2) and a magnetic field per filament of B-f = 32 +/- 3 nG. This is in agreement with estimates obtained with a complementary method based on synchrotron emission stacking, and with cosmological simulations if primordial magnetic fields are amplified by astrophysical source field seeding. The measurement of an RRM0, f supports the presence of diffuse baryonic gas in filaments. We also estimated a conservative upper limit of the filament magnetic turbulence of sigma(RRM0,f) = 0.039 +/- 0.001 rad m(-2), concluding that the ordered magnetic field component dominates in filaments.
|
|
| 41. |
- Donini, Lorenzo M, et al.
(författare)
-
A consensus document on definition and diagnostic criteria for orthorexia nervosa
- 2022
-
Ingår i: Eating and Weight Disorders. - Milan : Springer. - 1124-4909 .- 1590-1262. ; 27, s. 3695-3711
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: Since the term orthorexia nervosa (ON) was coined from the Greek (ὀρθός, right and ὄρεξις, appetite) in 1997 to describe an obsession with “correct” eating, it has been used worldwide without a consistent definition. Although multiple authors have proposed diagnostic criteria, and many theoretical papers have been published, no consensus definition of ON exists, empirical primary evidence is limited, and ON is not a standardized diagnosis. These gaps prevent research to identify risk and protective factors, pathophysiology, functional consequences, and evidence-based therapeutic treatments. The aims of the current study are to categorize the common observations and presentations of ON pathology among experts in the eating disorder field, propose tentative diagnostic criteria, and consider which DSM chapter and category would be most appropriate for ON should it be included.Methods: 47 eating disorder researchers and multidisciplinary treatment specialists from 14 different countries across four continents completed a three-phase modified Delphi process, with 75% agreement determined as the threshold for a statement to be included in the final consensus document. In phase I, participants were asked via online survey to agree or disagree with 67 statements about ON in four categories: A–Definition, Clinical Aspects, Duration; B–Consequences; C–Onset; D–Exclusion Criteria, and comment on their rationale. Responses were used to modify the statements which were then provided to the same participants for phase II, a second round of feedback, again in online survey form. Responses to phase II were used to modify and improve the statements for phase III, in which statements that met the predetermined 75% of agreement threshold were provided for review and commentary by all participants.Results: 27 statements met or exceeded the consensus threshold and were compiled into proposed diagnostic criteria for ON.Conclusions: This is the first time a standardized definition of ON has been developed from a worldwide, multidisciplinary cohort of experts. It represents a summary of observations, clinical expertise, and research findings from a wide base of knowledge. It may be used as a base for diagnosis, treatment protocols, and further research to answer the open questions that remain, particularly the functional consequences of ON and how it might be prevented or identified and intervened upon in its early stages. Although the participants encompass many countries and disciplines, further research will be needed to determine if these diagnostic criteria are applicable to the experience of ON in geographic areas not represented in the current expert panel.Level of evidence: Level V: opinions of expert committees.© 2022, The Author(s).
|
|
| 42. |
- Donini, Lorenzo M., et al.
(författare)
-
Correction : A consensus document on definition and diagnostic criteria for orthorexia nervosa
- 2023
-
Ingår i: Eating and Weight Disorders. - Milan : Springer. - 1124-4909 .- 1590-1262. ; 28
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- In this article Rebecca C. Reynolds was missing from the author list. The complete correct author group is given below. Lorenzo M. Donini, Juan Ramón Barrada, Friederike Barthels, Thomas M. Dunn, Camille Babeau, Anna Brytek-Matera, Hellas Cena, Silvia Cerolini, Hye-hyun Cho, Maria Coimbra, Massimo Cuzzolaro, Claudia Ferreira, Valeria Galfano, Maria G. Grammatikopoulou, Souheil Hallit, Linn Håman, Phillipa Hay, Masahito Jimbo, Clotilde Lasson, Eva-Carin Lindgren, Renee McGregor, Marianna Minnetti, Edoardo Mocini, Sahar Obeid, Crystal D. Oberle, Maria-Dolores Onieva-Zafra, Marie-Christine Opitz, María-Laura Parra-Fernández, Reinhard Pietrowsky, Natalija Plasonja, Eleonora Poggiogalle, Adrien Rigó, Rachel F. Rodgers, Maria Roncero, Carmina Saldaña, Cristina Segura-Garcia, Jessica Setnick, Ji-Yeon Shin, Grazia Spitoni, Jana Strahler, Nanette Stroebele-Benschop, Patrizia Todisco, Mariacarolina Vacca, Martina Valente, Màrta Varga, Andrea Zagaria, Hana Flynn Zickgraf, Rebecca C. Reynolds & Caterina Lombardo. The original article [1] has been corrected. © 2023, Springer Nature Switzerland AG.
|
|
| 43. |
- Farnes, J.S., et al.
(författare)
-
Source finding in linear polarization for LOFAR, and SKA predecessor surveys, using Faraday moments
- 2018
-
Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 474:3, s. 3280-3296
-
Tidskriftsartikel (refereegranskat)abstract
- The optimal source-finding strategy for linear polarization data is an unsolved problem, with many inhibitive factors imposed by the technically challenging nature of polarization observations. Such an algorithm is essential for Square Kilometre Array (SKA) pathfinder surveys, such as the Multifrequency Snapshot Sky Survey with the LOw Frequency ARray (LOFAR), as data volumes are significant enough to prohibit manual inspection. We present a new strategy of 'Faraday Moments' for source-finding in linear polarization with LOFAR, using the moments of the frequency-dependent full-Stokes data (i.e. the mean, standard deviation, skewness, and excess kurtosis). Through simulations of the sky, we find that moments can identify polarized sources with a high completeness: 98.5 per cent at a signal to noise of 5. While the method has low reliability, rotation measure (RM) synthesis can be applied per candidate source to filter out instrumental and spurious detections. This combined strategy will result in a complete and reliable catalogue of polarized sources that includes the full sensitivity of the observational bandwidth. We find that the technique can reduce the number of pixels on which RM Synthesis needs to be performed by a factor of ≈1 × 10 5 for source distributions anticipated with modern radio telescopes. Through tests on LOFAR data, we find that the technique works effectively in the presence of diffuse emission. Extensions of this method are directly applicable to other upcoming radio surveys such as the POlarization Sky Survey of the Universe's Magnetism with the Australia Square Kilometre Array Pathfinder, and the SKA itself.
|
|
| 44. |
- Govaere, Olivier, et al.
(författare)
-
Transcriptomic profiling across the nonalcoholic fatty liver disease spectrum reveals gene signatures for steatohepatitis and fibrosis
- 2020
-
Ingår i: Science Translational Medicine. - Washington, DC, United States : American Association for the Advancement of Science (AAAS). - 1946-6234 .- 1946-6242. ; 12:572
-
Tidskriftsartikel (refereegranskat)abstract
- The mechanisms that drive nonalcoholic fatty liver disease (NAFLD) remain incompletely understood. This large multicenter study characterized the transcriptional changes that occur in liver tissue across the NAFLD spectrum as disease progresses to cirrhosis to identify potential circulating markers. We performed high-throughput RNA sequencing on a discovery cohort comprising histologically characterized NAFLD samples from 206 patients. Unsupervised clustering stratified NAFLD on the basis of disease activity and fibrosis stage with differences in age, aspartate aminotransferase (AST), type 2 diabetes mellitus, and carriage of PNPLA3 rs738409, a genetic variant associated with NAFLD. Relative to early disease, we consistently identified 25 differentially expressed genes as fibrosing steatohepatitis progressed through stages F2 to F4. This 25-gene signature was independently validated by logistic modeling in a separate replication cohort (n = 175), and an integrative analysis with publicly available single-cell RNA sequencing data elucidated the likely relative contribution of specific intrahepatic cell populations. Translating these findings to the protein level, SomaScan analysis in more than 300 NAFLD serum samples confirmed that circulating concentrations of proteins AKR1B10 and GDF15 were strongly associated with disease activity and fibrosis stage. Supporting the biological plausibility of these data, in vitro functional studies determined that endoplasmic reticulum stress up-regulated expression of AKR1B10, GDF15, and PDGFA, whereas GDF15 supplementation tempered the inflammatory response in macrophages upon lipid loading and lipopolysaccharide stimulation. This study provides insights into the pathophysiology of progressive fibrosing steatohepatitis, and proof of principle that transcriptomic changes represent potentially tractable and clinically relevant markers of disease progression.
|
|
| 45. |
- Harper, G. M., et al.
(författare)
-
SOFIA-EXES Mid-IR Observations of [Fe II] Emission from the Extended Atmosphere of Betelgeuse
- 2017
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 836:1
-
Tidskriftsartikel (refereegranskat)abstract
- We present a NASA-DLR SOFIA-Echelon Cross Echelle Spectrograph (EXES) and NASA Infrared Telescope Facility-Texas Echelon Cross Echelle Spectrograph (TEXES) mid-IR R ≃ 50,000 spectral study of forbidden Fe II transitions in the early-type M supergiants, Betelgeuse (α Ori: M2 Iab) and Antares (α Sco: M1 Iab + B3 V). With EXES, we spectrally resolve the ground term [Fe II] 25.99 μm ( a 6DJ= 7/2-9/2: Eup = 540 K) emission from Betelgeuse. We find a small centroid blueshift of 1.9 ± 0.4 km s-1 that is a significant fraction (20%) of the current epoch wind speed, with a FWHM of 14.3 ± 0.1 km s-1. The TEXES observations of [Fe II] 17.94 μm (a 4FJ= - 7/2 9/2: Eup = 3400 K) show a broader FWHM of 19.1 ± 0.2 km s-1, consistent with previous observations, and a small redshift of 1.6 ± 0.6 km s-1 with respect to the adopted stellar center-ofmass velocity of VCoM = 20.9 ± 0.3 km s-1. To produce [Fe II] 25.99 μm blueshifts of 20% wind speed requires that the emission arises closer to the star than existing thermal models for α Ori's circumstellar envelope predict. This implies a more rapid wind cooling to below 500 K within 10R∗ (q∗ = 44 mas, dist = 200 pc) of the star, where the wind has also reached a significant fraction of the maximum wind speed. The line width is consistent with the turbulence in the outflow being close to the hydrogen sound speed. EXES observations of [Fe II] 22.90 μm ( a 4DJ= 5/2-7/2: Eup = 11,700 K) reveal no emission from either star. These findings confirm the dominance of cool plasma in the mixed region where hot chromospheric plasma emits copiously in the UV, and they also constrain the wind heating produced by the poorly understood mechanisms that drive stellar outflows from these low variability and weak-dust signature stars.
|
|
| 46. |
|
|
| 47. |
- O'Sullivan, S. P., et al.
(författare)
-
New constraints on the magnetization of the cosmic web using LOFAR Faraday rotation observations
- 2020
-
Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 495:3, s. 2607-2619
-
Tidskriftsartikel (refereegranskat)abstract
- Measuring the properties of extragalactic magnetic fields through the effect of Faraday rotation provides a means to understand the origin and evolution of cosmic magnetism. Here we use data from the LOFAR Two-Metre Sky Survey (LoTSS) to calculate the Faraday rotation measure (RM) of close pairs of extragalactic radio sources. By considering the RM difference (Delta RM) between physical pairs (e.g. double-lobed radio galaxies) and non-physical pairs (i.e. close projected sources on the sky), we statistically isolate the contribution of extragalactic magnetic fields to Delta RM along the line of sight between non-physical pairs. From our analysis, we find no significant difference between the ?RM distributions of the physical and non-physical pairs, limiting the excess Faraday rotation contribution to <1.9 rad/m(2) (similar to 95% confidence). We use this limit with a simple model of an inhomogeneous universe to place an upper limit of 4 nG on the cosmological co-moving magnetic field strength on Mpc scales. We also compare the RM data with a more realistic suite of cosmological MHD simulations, that explore different magnetogenesis scenarios. Both magnetization of the large scale structure by astrophysical processes such as galactic and AGN outflows, and simple primordial scenarios with seed magnetic field strengths <0.5 nG cannot be rejected by the current data; while stronger primordial fields or models with dynamo amplification in filaments are disfavoured.
|
|
| 48. |
- Stuardi, C., et al.
(författare)
-
The LOFAR view of intergalactic magnetic fields with giant radio galaxies
- 2020
-
Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 638
-
Tidskriftsartikel (refereegranskat)abstract
- Giant radio galaxies (GRGs) are physically large radio sources that extend well beyond their host galaxy environment. Their polarization properties are affected by the poorly constrained magnetic field that permeates the intergalactic medium on megaparsec scales. A low frequency (< 200 MHz) polarization study of this class of radio sources is now possible with LOFAR.Aims. Here we investigate the polarization properties and Faraday rotation measure (RM) of a catalog of GRGs detected in the LOFAR Two-meter Sky Survey. This is the first low frequency polarization study of a large sample of radio galaxies that were selected on their physical size. We explore the magneto-ionic properties of their under-dense environment and probe intergalactic magnetic fields using the Faraday rotation properties of their radio lobes. LOFAR is a key instrument for this kind of analysis because it can probe small amounts of Faraday dispersion (< 1 rad m(-2)), which are associated with weak magnetic fields and low thermal gas densities.Methods. We used RM synthesis in the 120-168 MHz band to search for polarized emission and to derive the RM and fractional polarization of each detected source component. We study the depolarization between 1.4 GHz and 144 MHz using images from the NRAO VLA Sky Survey. We investigate the correlation of the detection rate, the RM difference between the lobes, and the depolarization with different parameters as follows: the angular and linear size of the sources and the projected distance from the closest foreground galaxy cluster. In our sample, we also included 3C 236, which is one of the largest radio galaxies known.Results. From a sample of 240 GRGs, we detected 37 sources in polarization, all of which have a total flux density above 56 mJy. We detected significant RM differences between the lobes, which would be inaccessible at gigahertz frequencies, with a median value of similar to 1 rad m(-2). The fractional polarization of the detected GRGs at 1.4 GHz and 144 MHz is consistent with a small amount of Faraday depolarization (a Faraday dispersion < 0.3 rad m(-2)). Our analysis shows that the lobes are expanding into a low-density (< 10(-5) cm(-3)) local environment that is permeated by weak magnetic fields (< 0.1 G) with fluctuations on scales of 3-25 kpc. The presence of foreground galaxy clusters appears to influence the polarization detection rate up to 2R(500). In general, this work demonstrates the ability of LOFAR to quantify the rarefied environments in which these GRGs exist and highlights them as an excellent statistical sample to use as high precision probes of magnetic fields in the intergalactic medium and the Milky Way.
|
|
| 49. |
|
|
| 50. |
|
|
