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Sökning: WFRF:(Hayes Matthew)

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1.
  • Falster, Daniel, et al. (författare)
  • AusTraits, a curated plant trait database for the Australian flora
  • 2021
  • Ingår i: Scientific Data. - : Nature Portfolio. - 2052-4463. ; 8:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We introduce the AusTraits database - a compilation of values of plant traits for taxa in the Australian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across 28,640 taxa from field campaigns, published literature, taxonomic monographs, and individual taxon descriptions. Traits vary in scope from physiological measures of performance (e.g. photosynthetic gas exchange, water-use efficiency) to morphological attributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecological variation. AusTraits contains curated and harmonised individual- and species-level measurements coupled to, where available, contextual information on site properties and experimental conditions. This article provides information on version 3.0.2 of AusTraits which contains data for 997,808 trait-by-taxon combinations. We envision AusTraits as an ongoing collaborative initiative for easily archiving and sharing trait data, which also provides a template for other national or regional initiatives globally to fill persistent gaps in trait knowledge.
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2.
  • Abolfathi, Bela, et al. (författare)
  • The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
  • 2018
  • Ingår i: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
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3.
  • The Seventeenth Data Release of the Sloan Digital Sky Surveys : Complete Release of MaNGA, MaStar, and APOGEE-2 Data
  • 2022
  • Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics (IOP). - 0067-0049 .- 1538-4365. ; 259:2
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 survey that publicly releases infrared spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the subsurvey Time Domain Spectroscopic Survey data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey subsurvey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated value-added catalogs. This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper, Local Volume Mapper, and Black Hole Mapper surveys.
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4.
  • Aguado, D. S., et al. (författare)
  • The Fifteenth Data Release of the Sloan Digital Sky Surveys : First Release of MaNGA-derived Quantities, Data Visualization Tools, and Stellar Library
  • 2019
  • Ingår i: Astrophysical Journal Supplement Series. - : Institute of Physics Publishing (IOPP). - 0067-0049 .- 1538-4365. ; 240:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July-2017 July). This is the third data release for SDSS-IV, and the 15th from SDSS (Data Release Fifteen; DR15). New data come from MaNGA-we release 4824 data cubes, as well as the first stellar spectra in the MaNGA Stellar Library (MaStar), the first set of survey-supported analysis products (e.g., stellar and gas kinematics, emission-line and other maps) from the MaNGA Data Analysis Pipeline, and a new data visualization and access tool we call "Marvin." The next data release, DR16, will include new data from both APOGEE-2 and eBOSS; those surveys release no new data here, but we document updates and corrections to their data processing pipelines. The release is cumulative; it also includes the most recent reductions and calibrations of all data taken by SDSS since first light. In this paper, we describe the location and format of the data and tools and cite technical references describing how it was obtained and processed. The SDSS website (www.sdss.org) has also been updated, providing links to data downloads, tutorials, and examples of data use. Although SDSS-IV will continue to collect astronomical data until 2020, and will be followed by SDSS-V (2020-2025), we end this paper by describing plans to ensure the sustainability of the SDSS data archive for many years beyond the collection of data.
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5.
  • Berg, Danielle A., et al. (författare)
  • The COS Legacy Archive Spectroscopy Survey (CLASSY) Treasury Atlas
  • 2022
  • Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 261:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Far-ultraviolet (FUV; ∼1200–2000 Å) spectra are fundamental to our understanding of star-forming galaxies, providing a unique window on massive stellar populations, chemical evolution, feedback processes, and reionization. The launch of the James Webb Space Telescope will soon usher in a new era, pushing the UV spectroscopic frontier to higher redshifts than ever before; however, its success hinges on a comprehensive understanding of the massive star populations and gas conditions that power the observed UV spectral features. This requires a level of detail that is only possible with a combination of ample wavelength coverage, signal-to-noise, spectral-resolution, and sample diversity that has not yet been achieved by any FUV spectral database. We present the Cosmic Origins Spectrograph Legacy Spectroscopic Survey (CLASSY) treasury and its first high-level science product, the CLASSY atlas. CLASSY builds on the Hubble Space Telescope (HST) archive to construct the first high-quality (S/N1500 Å ≳ 5/resel), high-resolution (R ∼ 15,000) FUV spectral database of 45 nearby (0.002 < z < 0.182) star-forming galaxies. The CLASSY atlas, available to the public via the CLASSY website, is the result of optimally extracting and coadding 170 archival+new spectra from 312 orbits of HST observations. The CLASSY sample covers a broad range of properties including stellar mass (6.2 < log M⋆(M⊙) < 10.1), star formation rate (−2.0 < log SFR (M⊙ yr−1) < +1.6), direct gas-phase metallicity (7.0 < 12+log(O/H) < 8.8), ionization (0.5 < O32 < 38.0), reddening (0.02 < E(B − V) < 0.67), and nebular density (10 < ne (cm−3) < 1120). CLASSY is biased to UV-bright star-forming galaxies, resulting in a sample that is consistent with the z ∼ 0 mass–metallicity relationship, but is offset to higher star formation rates by roughly 2 dex, similar to z ≳ 2 galaxies. This unique set of properties makes the CLASSY atlas the benchmark training set for star-forming galaxies across cosmic time.
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6.
  • Campbell, PJ, et al. (författare)
  • Pan-cancer analysis of whole genomes
  • 2020
  • Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
  • Tidskriftsartikel (refereegranskat)abstract
    • Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
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7.
  • Hayes, Matthew, 1977- (författare)
  • Lyman-alpha imaging of starburst galaxies in the local universe and beyond
  • 2007
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • The last decade has seen huge advances in studies of astrophysical cosmology, primarily as a result of developments in telescopic facilities. One of the primary observational signatures of actively star forming galaxies in the distant universe is the Lyman-alpha emission line (Lyα). The line is used either to search for objects or as a spectral feature for definite redshift confirmation. In recent years, high-z Lyα surveys have been used to constrain cosmic star formation history, investigate large scale structure, and examine the neutral hydrogen fraction of the universe. This doctoral thesis is directly concerned with studies of the Lyα emission from star-forming galaxies and the validity of Lyα as a cosmological tool.The approach is to study a sample of local actively star forming galaxies using data obtained with the Hubble Space Telescope (HST). Imaging observations have been performed in the Lyα line, Hα, and various continuum bandpasses in the ultraviolet and optical wavelength domains. Sophisticated tools have been developed for the analysis of the images, resulting also in theoretical exploration of Lyα-related observables from galaxies at high-z. Model simulations are presented, along with a methodology by which to interpret high-z survey data. HST imaging results call into question the interpretations of many high-z Lyα surveys. More specifically, the first direct observational evidence is presented for the emission of Lyα photons after resonant scattering in neutral hydrogen and low surface-brightness Lyα halos are found as a result. Imaging reveals Lyα morphologies that systematically differ from morphologies probed by stellar light or non-resonant tracers of the nebular gas. Based upon Hα observations and recombination theory, the fraction of Lyα photons that escape is found never to exceed 20% in any of the observed targets, despite the violent star-formation known to be taking place. Even after internal dust corrections, a deficit from the predicted Lyα/Hα line ratio is always found. The interpretation is that scattering events systematically enhance the probability of absorption of Lyα by dust grains. If these galaxies are representative of those that fall into the data-sets of high-z Lyα surveys, some cosmological estimates may be in error by an order of magnitude.
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8.
  • Hayes, Matthew, et al. (författare)
  • O VI EMISSION IMAGING OF A GALAXY WITH THE HUBBLE SPACE TELESCOPE : A WARM GAS HALO SURROUNDING THE INTENSE STARBURST SDSS J115630.63+500822.1
  • 2016
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 828:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We report results from a new Hubble Space Telescope campaign that targets the O VI lambda lambda 1032, 1038 angstrom doublet in emission around intensely star-forming galaxies. The program aims to characterize the energy balance in starburst galaxies and gas cooling in the difficult-to-map coronal temperature regime of 2-5 x 10(5) K. We present the first resolved image of gas emission in the O VI line. Our target, SDSS J115630.63+500822.1, is very compact in the continuum but displays O VI emission to radii of 23 kpc. The surface brightness profile is well fit by an exponential with a scale length of 7.5 kpc. This is 10 times the size of the photoionized gas, and we estimate that about 1/6 the total O VI luminosity comes from resonantly scattered continuum radiation. Spectroscopy-which closely resembles a stacked sample of archival spectra-confirms the O VI emission, and determines the column density and outflow velocity from blueshifted absorption. The combination of measurements enables a large number of calculations with few assumptions. The O VI regions fill only similar to 10-3 of the volume. By comparing the cooling time with the cloud sound-crossing time, the cooling distance with the size, and the pressure in the O VI and nebular gas, we conclude that the O VI-bearing gas cannot have been lifted to the scale height at this temperature, and must be cooling in situ through this coronal temperature regime. The coronal phase contains similar to 1% of the ionized mass, and its kinetic energy at a given instant is similar to 1% of the budget set by supernova feedback. However, a much larger amount of the gas must have cooled through this phase during the star formation episode. The outflow exceeds the escape velocity and the gas may become unbound, but it will recombine before it escapes and become visible to Lyman (and O I) spectroscopy. The mapping of this gas represents a crucial step in further constraining galaxy formation scenarios and guiding the development of future astronomical satellites.
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9.
  • Impellizzeri, Franco M., et al. (författare)
  • Patient-reported outcome measures for hip-related pain : A review of the available evidence and a consensus statement from the International Hip-related Pain Research Network, Zurich 2018
  • 2020
  • Ingår i: British journal of sports medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 54:14, s. 848-857
  • Forskningsöversikt (refereegranskat)abstract
    • Hip-related pain is a well-recognised complaint among active young and middle-aged active adults. People experiencing hip-related disorders commonly report pain and reduced functional capacity, including difficulties in executing activities of daily living. Patient-reported outcome measures (PROMs) are essential to accurately examine and compare the effects of different treatments on disability in those with hip pain. In November 2018, 38 researchers and clinicians working in the field of hip-related pain met in Zurich, Switzerland for the first International Hip-related Pain Research Network meeting. Prior to the meeting, evidence summaries were developed relating to four prioritised themes. This paper discusses the available evidence and consensus process from which recommendations were made regarding the appropriate use of PROMs to assess disability in young and middle-aged active adults with hip-related pain. Our process to gain consensus had five steps: (1) systematic review of systematic reviews; (2) preliminary discussion within the working group; (3) update of the more recent high-quality systematic review and examination of the psychometric properties of PROMs according to established guidelines; (4) formulation of the recommendations considering the limitations of the PROMs derived from the examination of their quality; and (5) voting and consensus. Out of 102 articles retrieved, 6 systematic reviews were selected and assessed for quality according to AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews). Two showed moderate quality. We then updated the most recent review. The updated literature search resulted in 10 additional studies that were included in the qualitative synthesis. The recommendations based on evidence summary and PROMs limitations were presented at the consensus meeting. The group makes the following recommendations: (1) the Hip and Groin Outcome Score (HAGOS) and the International Hip Outcome Tool (iHOT) instruments (long and reduced versions) are the most appropriate PROMs to use in young and middle-aged active adults with hip-related pain; (2) more research is needed into the utility of the HAGOS and the iHOT instruments in a non-surgical treatment context; and (3) generic quality of life measures such as the EuroQoL-5 Dimension Questionnaire and the Short Form Health Survey-36 may add value for researchers and clinicians in this field. We conclude that as none of the instruments shows acceptable quality across various psychometric properties, more methods studies are needed to further evaluate the validity of these PROMS-the HAGOS and iHOT-as well as the other (currently not recommended) PROMS.
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10.
  • James, Bethan L., et al. (författare)
  • CLASSY. II. A Technical Overview of the COS Legacy Archive Spectroscopic Survey
  • 2022
  • Ingår i: Astrophysical Journal Supplement Series. - : American Astronomical Society. - 0067-0049 .- 1538-4365. ; 262:2
  • Tidskriftsartikel (refereegranskat)abstract
    • The COS Legacy Archive Spectroscopic SurveY (CLASSY) is designed to provide the community with a spectral atlas of 45 nearby star-forming galaxies that were chosen to cover similar properties to those seen at high z (z > 6). The prime high-level science product of CLASSY is accurately coadded UV spectra, ranging from ∼1000 to 2000 Å, derived from a combination of archival and new data obtained with HST's Cosmic Origins Spectrograph (COS). This paper details the multistage technical processes of creating this prime data product and the methodologies involved in extracting, reducing, aligning, and coadding far-ultraviolet and near-ultraviolet (NUV) spectra. We provide guidelines on how to successfully utilize COS observations of extended sources, despite COS being optimized for point sources, and best-practice recommendations for the coaddition of UV spectra in general. Moreover, we discuss the effects of our reduction and coaddition techniques in the scientific application of the CLASSY data. In particular, we find that accurately accounting for flux calibration offsets can affect the derived properties of the stellar populations, while customized extractions of NUV spectra for extended sources are essential for correctly diagnosing the metallicity of galaxies via C iii] nebular emission. Despite changes in spectral resolution of up to ∼25% between individual data sets (due to changes in the COS line-spread function), no adverse affects were observed on the difference in velocity width and outflow velocities of isolated absorption lines when measured in the final combined data products, owing in part to our signal-to-noise regime of S/N < 20.
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11.
  • Kato, Yuta, et al. (författare)
  • A high dust emissivity index beta for a CO-faint galaxy in a filamentary Ly alpha nebula at z=3.1
  • 2018
  • Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press (OUP). - 0004-6264 .- 2053-051X. ; 70:5
  • Tidskriftsartikel (refereegranskat)abstract
    • We present CO J = 4-3 line and 3 mm dust continuum observations of a 100 kpc-scale filamentary Ly alpha nebula (SSA22 LAB18) at z = 3.1 using the Atacama Large Millimeter/submillimeter Array (ALMA). We detected the CO J = 4-3 line at a systemic z(CO) = 3.093 +/- 0.001 at 11 sigma from one of the ALMA continuum sources associated with the Ly alpha filament. We estimated the CO J = 4-3 luminosity of L'(CO(4-3)) = (2.3 +/- 0.2) x 10(9) Kkms(-1) pc(2) for this CO source, which is one order of magnitude smaller than those of typical z > 1 dusty star-forming galaxies (DSFGs) of similar far-infrared luminosity L-IR similar to 10(12) L-circle dot. We derived a molecular gas mass of M-gas = (4.4(-0.6)(+0.9)) x 10(9) M-circle dot and a star-formation rate of SFR = 270 +/- 160M(circle dot) yr(-1). We also estimated a gas depletion time of tau(dep) = 17 +/- 10 Myr, which is shorter than those of typical DSFGs. It is suggested that this source is in the transition phase from DSFG to a gas-poor, early-type galaxy. From ALMA to Herschel multi-band dust continuum observations, we measured a dust emissivity index beta = 2.3 +/- 0.2, which is similar to those of local gas-poor, early-type galaxies. From recent laboratory experiments, the specific chemical compositions needed to reproduce such a high beta for interstellar dust at the submillimeter wavelengths. ALMA CO and multi-band dust continuum observations can constrain the evolutionary stage of high-redshift galaxies through tau(dep) and beta, and thus we can investigate the chemical composition of dust even in the early Universe.
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12.
  • Kemp, Joanne L., et al. (författare)
  • Physiotherapist-led treatment for young to middle-aged active adults with hip-related pain : Consensus recommendations from the International Hip-related Pain Research Network, Zurich 2018
  • 2020
  • Ingår i: British journal of sports medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 54:9, s. 504-511
  • Tidskriftsartikel (refereegranskat)abstract
    • The 1st International Hip-related Pain Research Network meeting discussed four prioritised themes concerning hip-related pain in young to middle-aged adults: (1) diagnosis and classification of hip-related pain; (2) patient-reported outcome measures for hip-related pain; (3) measurement of physical capacity for hip-related pain; (4) physiotherapist-led treatment for hip-related pain. Thirty-eight expert researchers and clinicians working in the field of hip-related pain attended the meeting. This manuscript relates to the theme of physiotherapist-led treatments for hip-related pain. A systematic review on the efficacy of physiotherapist-led interventions for hip-related pain (published separately) was conducted and found that strong evidence for physiotherapist-led treatments was lacking. Prior to the meeting, draft consensus recommendations for consideration in the meeting were also developed based on the systematic review. The draft consensus recommendations were presented to all of the meeting participants via email, at least 1 week prior to the meeting. At the meeting, these recommendations were discussed, revised and voted on. Six recommendations for clinical practice and five recommendations for research were included and all gained consensus. Recommendations for clinical practice were that (i) Exercise-based treatments are recommended for people with hip-related pain. (ii) Exercise-based treatment should be at least 3 months duration. (iii) Physiotherapist-led rehabilitation after hip surgery should be undertaken. (iv) Patient-reported outcome measures, measures of physical impairment and measures of psychosocial factors should be used to monitor response to treatment. (v) Physical activity (that may include sport) is recommended for people with hip-related pain. (vi) Clinicians should discuss patient expectations, use shared-decision making and provide education. Recommendations for research were (i) Reporting of exercise programmes: Exercise descriptors such as load magnitude, number of repetitions and sets, duration of whole programme, duration of contractile element of exercise, duration of one repetition, time under tension, rest between repetitions, range of motion through which the exercise is performed, and rest between exercise sessions should be reported. (ii) Research should investigate the optimal frequency, intensity, time, type, volume and progression of exercise therapy. (iii) Research should examine the effect of patient education in people with hip-related pain. (iv) Research should investigate the effect of other treatments used in people with hip-related pain (for example: manual therapy, medications, injections). (v) Research should examine the impact of comorbidities and social determinants on treatment effectiveness in people with hip-related pain. Clinicians and researchers working with young to middle-aged active adults with hip-related pain may use these consensus recommendations to guide, develop, test and implement individualised, evidence-based physiotherapist-led rehabilitation programmes.
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13.
  • Mosler, Andrea Britt, et al. (författare)
  • Standardised measurement of physical capacity in young and middle-aged active adults with hip-related pain : Recommendations from the first International Hip-related Pain Research Network (IHiPRN) meeting, Zurich, 2018
  • 2020
  • Ingår i: British journal of sports medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 54:12, s. 702-710
  • Tidskriftsartikel (refereegranskat)abstract
    • Hip-related pain can significantly impact quality of life, function, work capacity, physical activity and family life. Standardised measurement methods of physical capacity of relevance to young and middle-aged active adults with hip-related pain are currently not established. The aim of this consensus paper was to provide recommendations for clinical practice and research on standardised measurement methods of physical capacity in young and middle-aged active adults with hip-related pain. Four areas of importance were identified: (1) clinical measures (range of motion, muscle strength, functional impairments), (2) laboratory-based measures (biomechanics and muscle function (muscle activity, size and adiposity)), (3) physical activity, and (4) return to sport/performance. The literature was reviewed, and a summary circulated to the working group to inform discussion at the consensus meeting. The working group developed clinical and research recommendations from the literature review, which were further discussed and modified within the working group at the consensus meeting. These recommendations were then presented to all 38 International Hip-related Pain Research Network (IHiPRN) participants for further discussion, refinement and consensus voting. Therefore, the recommendations voted on were based on a combination of current evidence and expert opinion. The consensus meeting voted on 13 recommendations, six of which were clinically orientated, and seven more research specific. We recommended that clinicians working with young and middle-aged active adults with hip-related pain assess strength using objective methods of measurement, and clinically assess performance of functional tasks, including walking and running. Physical activity should be quantified using both self-reported and objective measures, and patient expectations of recovery should be quantified prior to treatment. It was recommended that return to physical activity (including sport and occupation) be quantified, and sport-specific activities should be assessed prior to return to sport. The IHiPRN participants were uncertain regarding recommendations for range of motion assessment. Research recommendations were that the measurement properties of range of motion, strength and functional performance tests be investigated, reported and improved in both clinical and research settings. Reporting of movement-related parameters (biomechanics and muscle function) should be standardised and the relationship among movement-related parameters, symptoms, function, quality of life, and intra-articular and imaging findings should be investigated. Quantification of return to physical activity (including sport and occupational demands) is required in future research, and the return to sport continuum should be used. Future research is required to determine the best criteria for rehabilitation progression and return to physical activity following hip-related pain management.
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14.
  • Reiman, Michael P., et al. (författare)
  • Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018
  • 2020
  • Ingår i: British journal of sports medicine. - : BMJ. - 0306-3674 .- 1473-0480. ; 54:11, s. 631-641
  • Forskningsöversikt (refereegranskat)abstract
    • There is no agreement on how to classify, define or diagnose hip-related pain-a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion-adduction-internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head-neck radiographs are the initial diagnostic imaging of choice-advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.
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15.
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16.
  • Rutkowski, Michael J., et al. (författare)
  • LYMAN CONTINUUM ESCAPE FRACTION OF STAR-FORMING DWARF GALAXIES AT z similar to 1
  • 2016
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 819:1
  • Tidskriftsartikel (refereegranskat)abstract
    • To date, no direct detection of Lyman continuum emission has been measured for intermediate-redshift (z similar to 1) star-forming galaxies. We combine Hubble Space Telescope grism spectroscopy with GALEX UV and ground-based optical imaging to extend the search for escaping Lyman continuum to a large (similar to 600) sample of z similar to 1 low-mass (log((M) over bar) similar or equal to 9.3M(circle dot)), moderately star-forming ((Psi) over bar less than or similar to 10M(circle dot) yr(-1)) galaxies selected initially on H alpha emission. The characteristic escape fraction of LyC from star-forming galaxies (SFGs) that populate this parameter space remains weakly constrained by previous surveys, but these faint (sub-L-star) SFGs are assumed to play a significant role in the reionization of neutral hydrogen in the intergalactic medium (IGM) at high redshift z > 6. We do not make an unambiguous detection of escaping LyC radiation from this z similar to 1 sample, individual non-detections to constrain the absolute Lyman continuum escape fraction, f(esc) < 2.1% (3 sigma). We measure an upper limit of f(esc) < 9.6% from a sample of SFGs selected on high H alpha equivalent width (EW > 200 angstrom), which are thought to be close analogs of high redshift sources of reionization. For reference, we also present an emissivity-weighted escape fraction that is useful for measuring the general contribution SFGs to the ionizing UV background. In the discussion, we consider the implications of these intermediate redshift constraints for the reionization of hydrogen in the IGM at high (z > 6) redshift. If we assume our z similar to 1 SFGs, for which we measure this emissivity-weighted f(esc), are analogs to the high redshift sources of reionization, we find it is difficult to reconcile reionization by faint (MUV less than or similar to -13) SFGs with a low escape fraction (f(esc) < 3%), with constraints from independent high redshift observations. If f(esc) evolves with redshift, reionization by SFGs may be consistent with observations from Planck.
  •  
17.
  • Weinstein, John N., et al. (författare)
  • The cancer genome atlas pan-cancer analysis project
  • 2013
  • Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:10, s. 1113-1120
  • Forskningsöversikt (refereegranskat)abstract
    • The Cancer Genome Atlas (TCGA) Research Network has profiled and analyzed large numbers of human tumors to discover molecular aberrations at the DNA, RNA, protein and epigenetic levels. The resulting rich data provide a major opportunity to develop an integrated picture of commonalities, differences and emergent themes across tumor lineages. The Pan-Cancer initiative compares the first 12 tumor types profiled by TCGA. Analysis of the molecular aberrations and their functional roles across tumor types will teach us how to extend therapies effective in one cancer type to others with a similar genomic profile. © 2013 Nature America, Inc. All rights reserved.
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18.
  • Willer, Cristen J., et al. (författare)
  • Six new loci associated with body mass index highlight a neuronal influence on body weight regulation
  • 2009
  • Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 41:1, s. 25-34
  • Tidskriftsartikel (refereegranskat)abstract
    • Common variants at only two loci, FTO and MC4R, have been reproducibly associated with body mass index (BMI) in humans. To identify additional loci, we conducted meta-analysis of 15 genome-wide association studies for BMI (n > 32,000) and followed up top signals in 14 additional cohorts (n > 59,000). We strongly confirm FTO and MC4R and identify six additional loci (P < 5 x 10(-8)): TMEM18, KCTD15, GNPDA2, SH2B1, MTCH2 and NEGR1 (where a 45-kb deletion polymorphism is a candidate causal variant). Several of the likely causal genes are highly expressed or known to act in the central nervous system (CNS), emphasizing, as in rare monogenic forms of obesity, the role of the CNS in predisposition to obesity.
  •  
19.
  • Kanai, M, et al. (författare)
  • 2023
  • swepub:Mat__t
  •  
20.
  • Adamo, Angela, et al. (författare)
  • Star cluster formation in the most extreme environments: Insights from the HiPEEC survey
  • 2020
  • Ingår i: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 499:3, s. 3267-3294
  • Tidskriftsartikel (refereegranskat)abstract
    • We present the Hubble imaging Probe of Extreme Environments and Clusters (HiPEEC) survey. We fit HST NUV to NIR broad-band and H α fluxes to derive star cluster ages, masses, and extinctions and determine the star formation rate (SFR) of six merging galaxies. These systems are excellent laboratories to trace cluster formation under extreme gas physical conditions, rare in the local Universe, but typical for star-forming galaxies at cosmic noon. We detect clusters with ages of 1-500 Myr and masses that exceed 107 M☉. The recent cluster formation history and their distribution within the host galaxies suggest that systems such as NGC 34, NGC 1614, and NGC 4194 are close to their final coalescing phase, while NGC 3256, NGC 3690, and NGC 6052 are at an earlier/intermediate stage. A Bayesian analysis of the cluster mass function in the age interval 1-100 Myr provides strong evidence in four of the six galaxies that an exponentially truncated power law better describes the observed mass distributions. For two galaxies, the fits are inconclusive due to low number statistics. We determine power-law slopes β ∼ −1.5 to −2.0 and truncation masses, Mc, between 106 and a few times 107 M☉, among the highest values reported in the literature. Advanced mergers have higher Mc than early/intermediate merger stage galaxies, suggesting rapid changes in the dense gas conditions during the merger. We compare the total stellar mass in clusters to the SFR of the galaxy, finding that these systems are among the most efficient environments to form star clusters in the local Universe.
  •  
21.
  • Adamo, Angela, et al. (författare)
  • Super star clusters in Haro 11: properties of a very young starburst and evidence for a near-infrared flux excess
  • 2010
  • Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 407:2, s. 870-890
  • Tidskriftsartikel (refereegranskat)abstract
    • We have used multiband imaging to investigate the nature of an extreme starburst environment in the nearby Lyman break galaxy analogue Haro 11 (ESO350-IG038) by means of its stellar cluster population. The central starburst region has been observed in eight different high-resolution Hubble Space Telescope (HST) wavebands, sampling the stellar and gas components from UV to near-infrared. Photometric imaging of the galaxy was also carried out at 2.16μm by NaCo AO instrument at the ESO Very Large Telescope. We constructed integrated spectral energy distributions (SEDs) for about 200 star clusters located in the active star-forming regions and compared them with single stellar population models (suitable for physical properties of very young cluster population) in order to derive ages, masses and extinctions of the star clusters. The cluster age distribution we recover confirms that the present starburst has lasted for 40Myr, and shows a peak of cluster formation only 3.5 Myr old. With such an extremely young cluster population, Haro 11 represents a unique opportunity to investigate the youngest phase of the cluster formation process and evolution in starburst systems. We looked for possible relations between cluster ages, extinctions and masses. Extinction tends to diminish as a function of the cluster age, but the spread is large and reaches the highest dispersion for clusters in partial embedded phases (<5Myr). A fraction of low-mass (below 104 Msolar), very young (1-3Myr) clusters is missing, either because they are embedded in the parental molecular cloud and heavily extinguished, or because of blending with neighbouring clusters. The range of the cluster masses is wide; we observe that more than 30 per cent of the clusters have masses above 105 Msolar, qualifying them as super star clusters. Almost half of the cluster sample is affected by flux excesses at wavelengths >8000Å which cannot be explained by simple stellar evolutionary models. Fitting SED models over all wavebands leads to systematic overestimates of cluster ages and incorrect masses for the stellar population supplying the light in these clusters. We show that the red excess affects also the HST F814W filter, which is typically used to constrain cluster physical properties. The clusters which show the red excess are younger than 40Myr we discuss possible physical explanations for the phenomenon. Finally, we estimate that Haro 11 has produced bound clusters at a rate almost a factor of 10 higher than the massive and regular spirals, like the Milky Way. The present cluster formation efficiency is ~38 per cent of the galactic star formation rate.
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22.
  • Adamo, Angela, et al. (författare)
  • The Extremely Young Star Cluster Population In Haro 11
  • 2010
  • Ingår i: Galaxy Wars. - San Francisco : Astronomical Society of the Pacific. - 9781583817261 ; , s. 74-
  • Konferensbidrag (refereegranskat)abstract
    • We have performed a deep multi-band photometric analysis of the star cluster population of Haro 11. This starburst galaxy (log L_FUV = 10.3 L_sun) is considered a nearby analogue of Lyman break galaxies (LBGs) at high redshift. The study of the numerous star clusters in the systems is an effective way to investigate the formation and evolution of the starburst phase. In fact, the SED fitting models have revealed a surprisingly young star cluster population, with ages between 0.5 and 40 Myr, and estimated masses between 10^3 and 10^7 solar masses. An independent age estimation has been done with the EW(Halpha) analysis of each cluster. This last analysis has confirmed the young ages of the clusters. We noticed that the clusters with ages between 1 and 10 Myr show a flux excess in H (NIC3/F160W) and/or I (WFPC2/F814W) bands with respect to the evolutionary models. Once more Haro 11 represents a challenge to our understanding.
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23.
  • Adamo, Angela, et al. (författare)
  • The Massive Star Clusters in the Dwarf Merger ESO 185-IG13 : is the Red Excess Ubiquitous in Starbursts?
  • 2011
  • Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 414:3, s. 1793-1812
  • Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
    • We have investigated the starburst properties of the luminous blue compact galaxy ESO 185-IG13. The galaxy has been imaged with the high resolution cameras onboard to the Hubble Space Telescope. From the UV to the IR, the data reveal a system shaped by hundreds of young star clusters, and fine structures, like a tidal stream and a shell. The presence of numerous clusters and the perturbed morphology indicate that the galaxy has been involved in a recent merger event. Using previous simulations of shell formation in galaxy mergers we constrain potential progenitors of ESO 185-IG13. The analysis of the star cluster population is used to investigate the properties of the present starburst and to date the final merger event, which has produced hundreds of clusters younger than 100 Myr. We have found a peak of cluster formation only 3.5 Myr old. A large fraction of these clusters will not survive after 10-20 Myr, due to the "infant mortality" caused by gas expulsion. However, this sample of clusters represents an unique chance to investigate the youngest phases of cluster evolution. As already observed in the analog blue compact galaxy Haro 11, a fraction of young clusters are affected by a flux excess at wavelengths longer than 8000 \AA. Ages, masses, and extinctions of clusters with this NIR excess are estimated from UV and optical data. We discuss similarities and differences of the observed NIR excess in ESO 185-IG13 clusters with other cases in the literature. The cluster ages and masses are used to distinguish among the potential causes of the excess. We observe, as in Haro 11, that the use of the IR and the (commonly used) I band data results in overestimates of age and mass in clusters affected by the NIR excess. This has important implications for a number of related studies of star clusters.
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24.
  • Adamo, Angela, et al. (författare)
  • Tracing the star formation history of three Blue Compact galaxies through the analysis of their star clusters
  • 2009
  • Konferensbidrag (populärvet., debatt m.m.)abstract
    • We present preliminary results from a study of the compact star cluster populations in three local luminous blue compact galaxies: ESO 185-IG 013, ESO 350-IG 038 (a.k.a. Haro 11), and MRK 930. These systems show peculiar morphologies and the presence of hundreds of SCs that have been produced by the past, recent, and/or current starburst phases. We use a complete set of HST images ranging from the UV to IR for each galaxy. Deep images in V (WFPC2/f606w) and I (WFPC2/f814w) are used to capture most of the star cluster candidates up to the old ones (fainter) which have had, in the past, less possibility to be detected. The other bands are used in the SED fitting technique for constraining ages and masses. Our goals are to investigate the evolution of these three blue compact galaxies and the star cluster formation impact on their star formation history.
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25.
  • Amorín, R. O., et al. (författare)
  • Ubiquitous broad-line emission and the relation between ionized gas outflows and Lyman continuum escape in Green Pea galaxies
  • 2024
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 682
  • Tidskriftsartikel (refereegranskat)abstract
    • We report observational evidence of highly turbulent ionized gas kinematics in a sample of 20 Lyman continuum (LyC) emitters (LCEs) at low redshift (z ∼ 0.3). Detailed Gaussian modeling of optical emission line profiles in high-dispersion spectra consistently shows that both bright recombination and collisionally excited lines can be fitted as one or two narrow components with intrinsic velocity dispersion of σ ∼ 40 − 100 km s−1, in addition to a broader component with σ ∼ 100 − 300 km s−1, which contributes up to ∼40% of the total flux and is preferentially blueshifted from the systemic velocity. We interpret the narrow emission as highly ionized gas close to the young massive star clusters and the broader emission as a signpost of unresolved ionized outflows, resulting from massive stars and supernova feedback. We find a significant correlation between the width of the broad emission and the LyC escape fraction, with strong LCEs exhibiting more complex and broader line profiles than galaxies with weaker or undetected LyC emission. We provide new observational evidence supporting predictions from models and simulations; our findings suggest that gas turbulence and outflows resulting from strong radiative and mechanical feedback play a key role in clearing channels through which LyC photons escape from galaxies. We propose that the detection of blueshifted broad emission in the nebular lines of compact extreme emission-line galaxies can provide a new indirect diagnostic of Lyman photon escape, which could be useful to identify potential LyC leakers in the epoch of reionization with the JWST.
  •  
26.
  • Ao, Y., et al. (författare)
  • Deep Submillimeter and Radio Observations in the SSA22 Field. I. Powering Sources and the Ly alpha Escape Fraction of Ly alpha Blobs
  • 2017
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 850:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We study the heating mechanisms and Ly alpha escape fractions of 35 Ly alpha blobs (LABs) at z approximate to 3.1 in the SSA22 field. Dust continuum sources have been identified in 11 of the 35 LABs, all with star formation rates (SFRs) above 100M(circle dot) yr(-1). Likely radio counterparts are detected in 9 out of 29 investigated LABs. The detection of submillimeter dust emission is more linked to the physical size of the Ly alpha emission than to the Ly alpha luminosities of the LABs. A radio excess in the submillimeter/ radio-detected LABs is common, hinting at the presence of active galactic nuclei. Most radio sources without X-ray counterparts are located at the centers of the LABs. However, all X-ray counterparts avoid the central regions. This may be explained by absorption due to exceptionally large column densities along the line-of-sight or by LAB morphologies, which are highly orientation dependent. The median Lya escape fraction is about 3% among the submillimeter-detected LABs, which is lower than a lower limit of 11% for the submillimeter-undetected LABs. We suspect that the large difference is due to the high dust attenuation supported by the large SFRs, the dense large-scale environment as well as large uncertainties in the extinction corrections required to apply when interpreting optical data.
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27.
  • Arellano-Cordova, Karla Z., et al. (författare)
  • CLASSY V : The Impact of Aperture Effects on the Inferred Nebular Properties of Local Star-forming Galaxies
  • 2022
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 935:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Strong nebular emission lines are an important diagnostic tool for tracing the evolution of star-forming galaxies across cosmic time. However, different observational setups can affect these lines, and the derivation of the physical nebular properties. We analyze 12 local star-forming galaxies from the COS Legacy Spectroscopy SurveY (CLASSY) to assess the impact of using different aperture combinations on the determination of the physical conditions and gas-phase metallicity. We compare optical spectra observed with the Sloan Digital Sky Survey Data Release aperture, which has a 3'' diameter similar to COS, IFU, and long-slit spectra, including new LBT/MODS observations of five CLASSY galaxies. We calculate the reddening, electron densities and temperatures, metallicities, star formation rates, and equivalent widths (EWs). We find that measurements of the electron densities and temperatures, and metallicity remained roughly constant with aperture size, indicating that the gas conditions are relatively uniform for this sample. However, using IFU observations of three galaxies, we find that the E(B − V) values derived from the Balmer ratios decrease (by up to 53%) with increasing aperture size. The values change most significantly in the center of the galaxies, and level out near the COS aperture diameter of 2 5. We examine the relative contributions from the gas and stars using the Hα and [O iii] λ5007 EWs as a function of aperture light fraction, but find little to no variations within a given galaxy. These results imply that the optical spectra provide nebular properties appropriate for the far-UV CLASSY spectra, even when narrow 1 0 long-slit observations are used.
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28.
  • Arroyo-Polonio, A., et al. (författare)
  • A MUSE/VLT spatially resolved study of the emission structure of Green Pea galaxies
  • 2023
  • Ingår i: Astronomy and Astrophysics. - 0004-6361 .- 1432-0746. ; 677
  • Tidskriftsartikel (refereegranskat)abstract
    • Green Pea galaxies (GPs) present among the most intense starbursts known in the nearby Universe. These galaxies are regarded as local analogs of high-redshift galaxies, making them a benchmark in the understanding of the star formation processes and the galactic evolution in the early Universe. In this work, we performed an integral field spectroscopic (IFS) study for a set of 24 GPs to investigate the interplay between its ionized interstellar medium (ISM) and the massive star formation that these galaxies present. Observations were taken in the optical spectral range (λ4750 Å–λ9350 Å) with the MUSE spectrograph attached to the 8.2 m telescope VLT. Spatial extension criteria were employed to verify which GPs are spatially resolved in the MUSE data cubes. We created and analyzed maps of spatially distributed emission lines (at different stages of excitation), continuum emission, and properties of the ionized ISM (e.g., ionization structure indicators, physical-chemical conditions, dust extinction). We also took advantage of our IFS data to produce integrated spectra of selected galactic regions in order to study their physical-chemical conditions. Maps of relevant emission lines and emission line ratios show that higher-excitation gas is preferentially located in the center of the galaxy, where the starburst is present. The continuum maps, with an average angular extent of 4″, exhibit more complex structures than the emission line maps. However, the [O III]λ5007 Å emission line maps tend to extend beyond the continuum images (the average angular extent is 5.5″), indicating the presence of low surface brightness ionized gas in the outer parts of the galaxies. Hα/Hβ, [S II]/Hα, and [O I]/Hα maps trace low-extinction, optically thin regions. The line ratios [O III]/Hβ and [N II]/Hα span extensive ranges, with values varying from 0.5 dex to 0.9 dex and from −1.7 dex to −0.8 dex, respectively. Regarding the integrated spectra, the line ratios were fit to derive physical properties including the electron densities ne = 30 − 530 cm−3, and, in six GPs with a measurable [O III]λ4363 Å line, electron temperatures of Te = 11 500 K–15 500 K, so the direct method was applied in these objects to retrieve metallicities 12 + log(O/H)≃8. We found the presence of the high-ionizing nebular He IIλ4686 Å line in three GPs, where two of them present among the highest sSFR values (> 8 × 108 yr−1) in this sample. Non-Wolf-Rayet (WR) features are detected in these galaxy spectra.
  •  
29.
  • Atek, Hakim, et al. (författare)
  • Influence of physical galaxy properties on Ly alpha escape in star-forming galaxies
  • 2014
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 561, s. A89-
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Among the different observational techniques used to select high-redshift galaxies, the hydrogen recombination line Lyman-alpha (Ly alpha) is of particular interest because it gives access to the measurement of cosmological quantities such as the star formation rate (SFR) of distant galaxy populations. However, interpreting this line and calibrating such observables are still subject to serious uncertainties. Aims. In this context, it important to understand the mechanisms responsible for the attenuation of Ly alpha emission, and under what conditions the Ly alpha emission line can be used as a reliable star formation diagnostic tool. Methods. We used a sample of 24 Ly alpha emitters at z similar to 0.3 with an optical spectroscopic follow-up to calculate the Ly alpha escape fraction and its dependence upon different physical properties. We also examined the reliability of Ly alpha as a SFR indicator. We combined these observations with a compilation of Ly alpha emitters selected at z = 0-0.3 from the literature to assemble a larger sample. Results. We confirm that the Ly alpha escape fraction clearly depends on the dust extinction following the relation f(esc)(Ly alpha) = C-Ly alpha x 10(-0.4 E(B-V) kLy alpha) where k(Ly alpha) similar to 6.67 and C-Ly alpha = 0.22. However, the correlation does not follow the expected curve for a simple dust attenuation. A higher attenuation can be attributed to a scattering process, while f(esc)(Ly alpha) values that are clearly above the continuum extinction curve can be the result of various mechanisms that can lead to an enhancement of the Ly alpha output. We also observe that the strength of Ly alpha and the escape fraction appear unrelated to the galaxy metallicity. Regarding the reliability of Ly alpha as a SFR indicator, we show that the deviation of SFR(Ly alpha) from the true SFR (as traced by the UV continuum) is a function of the observed SFR(UV), which can be seen as the decrease in f(esc)(Ly alpha) with increasing UV luminosity. Moreover, we observe redshift dependence of this relationship, revealing the underlying evolution of f(esc)(Ly alpha) with redshift.
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30.
  • Atek, Hakim, et al. (författare)
  • On the detectability of Ly-alpha emission in star forming galaxies. The role of dust
  • 2008
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 488:491
  • Tidskriftsartikel (populärvet., debatt m.m.)abstract
    • Context: Lyman-alpha (Lyα) radiation is now widely used to investigate the galaxy formation and evolution in the high redshift universe. However, without a rigorous understanding of the processes regulating the Lyα escape fraction, physical interpretations of high-z observations remain questionable. Aims: We examine six nearby star forming galaxies to disentangle the role of the dust from other parameters such as gas kinematics, geometry, and ISM morphology in the obscuration of Lyα. Thereby, we attempt to understand the Lyα escape physics and infer the implications for high-redshift studies. Methods: We use HST/ACS imaging to produce continuum-subtracted Lyα maps, and ground-based observations (ESO/NTT and NOT) to map the Hα emission and the extinction E(B-V) in the gas phase derived from the Balmer decrement Hα/Hβ. Results: When large outflows are present, the Lyα emission does not appear to be correlated with the dust content, confirming the role of the Hi kinematics in the escape of Lyα photons. In the case of a dense, static Hi covering, we observe a damped absorption with a negative correlation between Lyα and E(B-V). We found that the Lyα escape fraction does not exceed 10% in all our galaxies and is mostly about 3% or below. Finally, because of the radiative transfer complexity of the Lyα line, star formation rate based on Lyα luminosity is underestimated with respect to that derived from UV luminosity. Simple reddening correction does not reconcile SFR(Lyα) with the total star formation rate. Conclusions: The dust is not necessarily the main Lyα escape regulatory factor. ISM kinematics and geometry may play a more significant role. The failure of simple dust correction to recover the intrinsic Lyα/Hα ratio or the total star formation rate should prompt us to be more cautious when interpreting high-z observations and related properties, such as SFRs based on Lyα alone. To this end, we propose a more realistic calibration for SFR(Lyα), which accounts for dust attenuation and resonant scattering effects via the Lyα escape fraction.
  •  
31.
  • Augustin, Ramona, et al. (författare)
  • MUSE-ALMA Haloes X : the stellar masses of gas-rich absorbing galaxies
  • 2024
  • Ingår i: Monthly notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 528:4, s. 6159-6166
  • Tidskriftsartikel (refereegranskat)abstract
    • The physical processes by which gas is accreted onto galaxies, transformed into stars, and then expelled from galaxies are of paramount importance to galaxy evolution studies. Observationally constraining each of these baryonic components in the same system, however, is challenging. Furthermore, simulations indicate that the stellar mass of galaxies is a key factor influencing CGM properties. Indeed, absorption lines detected against background quasars offer the most compelling way to study the cold gas in the circumgalactic medium (CGM). The MUSE-ALMA Haloes survey is composed of quasar fields covered with VLT/MUSE observations, comprising 32 H I absorbers at 0.2 < z < 1.4 and 79 associated galaxies, with available or upcoming molecular gas measurements from ALMA. We use a dedicated 40-orbit HST UVIS and IR WFC3 broad-band imaging campaign to characterize the stellar content of these galaxies. By fitting their spectral energy distribution, we establish they probe a wide range of stellar masses: 8.1 < log (M∗/M⊙) < 12.4. Given their star formation rates, most of these objects lie on the main sequence of galaxies. We also confirm a previously reported anticorrelation between the stellar masses and CGM hydrogen column density N (H I), indicating an evolutionary trend where higher mass galaxies are less likely to host large amounts of H I gas in their immediate vicinity up to 120 kpc. Together with other studies from the MUSE-ALMA Haloes survey, these data provide stellar masses of absorber hosts, a key component of galaxy formation and evolution, and observational constraints on the relation between galaxies and their surrounding medium. 
  •  
32.
  • Baudin, Eric, et al. (författare)
  • Unmet Medical Needs in Pulmonary Neuroendocrine (Carcinoid) Neoplasms
  • 2019
  • Ingår i: Neuroendocrinology. - : S. Karger AG. - 0028-3835 .- 1423-0194. ; 108:1, s. 7-17
  • Tidskriftsartikel (refereegranskat)abstract
    • Pulmonary carcinoids (PCs) display the common features of all well-differentiated neuroendocrine neoplasms (NEN) and are classified as low- and intermediate-grade malignant tumours (i.e., typical and atypical carcinoid, respectively). There is a paucity of randomised studies dedicated to advanced PCs and management principles are drawn from the larger gastroenteropancreatic NEN experience. There is growing evidence that NEN anatomic subgroups have different biology and different responses to treatment and, therefore, should be investigated as separate entities in clinical trials. In this review, we discuss the existing evidence and limitations of tumour classification, diagnostics and staging, prognostication, and treatment in the setting of PC, with focus on unmet medical needs and directions for the future.
  •  
33.
  • Beck, Melanie, et al. (författare)
  • SPECTROPOLARIMETRY CONFIRMS CENTRAL POWERING IN A Ly alpha NEBULA AT z=3.09
  • 2016
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 818:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We present a follow-up study to the imaging polarimetry performed by Hayes et al. on LAB1 in the SSA22 protocluster region. Arguably the most well-known Ly alpha blob, this radio-quiet emission-line nebula likely hosts a galaxy that. either is. undergoing significant star formation or hosts an active galactic nucleus, or both. We obtain deep, spatially resolved spectropolarimetry of the Ly alpha. emission and detect integrated linear polarization of 9%-13% +/- 2%-3% at a distance of approximately 15 kpc north and south of the peak of the Ly alpha. surface brightness with polarization vectors lying tangential to the galactic central source. In these same regions, we also detect a wavelength dependence in the polarization that. is low at the center of the Ly alpha. line profile and rises substantially in the wings of the profile. These polarization signatures are easily explained by a weak outflowing shell model. The spectral dependence of the polarization presented here provides a framework for future observations and interpretations of the southern portion of LAB1 in that any model for this system must be able to reproduce this particular spectral dependence. However, questions still remain for the northernmost spur of LAB1. In this region we detect total linear polarization of between 3% and 20% at the 5% significance level. Simulations predict that polarization should increase with radius for a symmetric geometry. That the northern spur does not suggests either that this region is not symmetric (which is likely) and exhibits variations in columns density. or that it is kinematically distinct from the rest of LAB1 and powered by another mechanism altogether.
  •  
34.
  • Bik, Arjan, et al. (författare)
  • Spatially resolved gas and stellar kinematics in compact starburst galaxies
  • 2022
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 666
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. The kinematics of galaxies provide valuable insights into their physics and assembly history. Kinematics are governed not only by the gravitational potential, but also by merger events and stellar feedback processes such as stellar winds and supernova explosions.Aims. We aim to identify what governs the kinematics in a sample of SDSS-selected nearby starburst galaxies, by obtaining spatially resolved measurements of the gas and stellar kinematics.Methods. We obtained near-infrared integral-field K-band spectroscopy with VLT/SINFONI for 15 compact starburst galaxies. We derived the integrated as well as spatially resolved stellar and gas kinematics. The stellar kinematics were derived from the CO absorption bands, and Paα and Brγ emission lines were used for the gas kinematics.Results. Based on the integrated spectra, we find that the majority of galaxies have gas and stellar velocity dispersion that are comparable. A spatially resolved comparison shows that the six galaxies that deviate show evidence for a bulge or stellar feedback. Two galaxies are identified as mergers based on their double-peaked emission lines. In our sample, we find a negative correlation between the ratio of the rotational velocity over the velocity dispersion (vrot/σ) and the star formation rate surface density.Conclusions. We propose a scenario where the global kinematics of the galaxies are determined by gravitational instabilities that affect both the stars and gas. This process could be driven by mergers or accretion events. Effects of stellar feedback on the ionised gas are more localised and detected only in the spatially resolved analysis. The mass derived from the velocity dispersion provides a reliable mass even if the galaxy cannot be spatially resolved. The technique used in this paper is applicable to galaxies at low and high redshift with the next generation of infrared-focussed telescopes (JWST and ELT).
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35.
  • Bik, Adrianus, et al. (författare)
  • Super star cluster feedback driving ionization, shocks and outflows in the halo of the nearby starburst ESO 338-IG04
  • 2018
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 619
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Stellar feedback strongly affects the interstellar medium (ISM) of galaxies. Stellar feedback in the first galaxies likely plays a major role in enabling the escape of LyC photons, which contribute to the re-ionization of the Universe. Nearby starburst galaxies serve as local analogues allowing for a spatially resolved assessment of the feedback processes in these galaxies. Aims. We aim to characterize the feedback effects from the star clusters in the local high-redshift analogue ESO 338-IG04 on the ISM and compare the results with the properties of the most massive clusters. Methods. We used high quality VLT/MUSE optical integral field data to derive the physical properties of the ISM such as ionization, density, shocks, and performed new fitting of the spectral energy distributions of the brightest clusters in ESO 338-IG04 from HST imaging. Results. We find that ESO 338-IG04 has a large ionized halo which we detect to a distance of 9 kpc. We identify four Wolf-Rayet (WR) clusters based on the blue and red WR bump. We follow previously identified ionization cones and find that the ionization of the halo increases with distance. Analysis of the galaxy kinematics shows two complex outflows driven by the numerous young clusters in the galaxy. We find a ring of shocked emission traced by an enhanced [O-I]/H alpha ratio surrounding the starburst and at the end of the outflow. Finally we detect nitrogen enriched gas associated with the outflow, likely caused by the WR stars in the massive star clusters. Conclusions. Photoionization dominates the central starburst and sets the ionization structure of the entire halo, resulting in a density bounded halo, facilitating the escape of LyC photons. Outside the central starburst, shocks triggered by an expanding super bubble become important. The shocks at the end of the outflow suggest interaction between the hot outflowing material and the more quiescent halo gas.
  •  
36.
  • Bik, Adrianus, et al. (författare)
  • VLT/MUSE view of the highly ionized outflow cones in the nearby starburst ESO338-IG04
  • 2015
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 576
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. The Lya line is an important diagnostic for star formation at high redshift, but interpreting its flux and line profile is difficult because of the resonance nature of Lya. Trends between the escape of Lya photons and dust and properties of the interstellar medium (ISM) have been found, but detailed comparisons between Lya emission and the properties of the gas in local high-redshift analogs are vital for understanding the relation between Lya emission and galaxy properties. Aims. For the first time, we can directly infer the properties of the ionized gas at the same location and similar spatial scales of the extended Lya halo around the local Lya emitter and Lyman-break galaxy analog ESO338-IG04. Methods. We obtained VLT/MUSE integral field spectra. We used ionization parameter mapping of the [S II]/[O III] line ratio and the kinematics of Ha to study the ionization state and kinematics of the ISM of ESO 338-IG04. Results. The velocity map reveals two outflows, one toward the north, the other toward the south of ESO338. The ionization parameter mapping shows that the entire central area of the galaxy is highly ionized by photons leaking from the HII regions around the youngest star clusters. Three highly ionized cones have been identified, of which one is associated with an outflow detected in the Ha. We propose a scenario where the outflows are created by mechanical feedback of the older clusters, while the highly ionized gas is caused by the hard ionizing photons emitted by the youngest clusters. A comparison with the Lya map shows that the (approximately bipolar) asymmetries observed in the Lya emission are consistent with the base of the outflows detected in Ha. No clear correlation with the ionization cones is found. Conclusions. The mechanical and ionization feedback of star clusters significantly changes the state of the ISM by creating ionized cones and outflows. The comparison with Lya suggests that especially the outflows could facilitate the escape of Lya photons.
  •  
37.
  • Bridge, Joanna S., et al. (författare)
  • The Ly alpha Reference Sample. VIII. Characterizing Ly alpha Scattering in Nearby Galaxies
  • 2018
  • Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 852:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We examine the dust geometry and Ly alpha scattering in the galaxies of the Lyman Alpha Reference Sample (LARS), a set of 14 nearby (0.02 < z < 0.2) Ly alpha-emitting and starbursting systems with Hubble Space Telescope Ly alpha, H alpha, and H beta imaging. We find that the global dust properties determined by line ratios are consistent with other studies, with some of the LARS galaxies exhibiting clumpy dust media, while others of them show significantly lower Ly alpha emission compared to their Balmer decrement. With the LARS imaging, we present Ly alpha/H alpha and H alpha/H beta maps with spatial resolutions as low as similar to 40 pc, and use these data to show that in most galaxies, the dust geometry is best modeled by three distinct regions: a central core where dust acts as a screen, an annulus where dust is distributed in clumps, and an outer envelope where Ly alpha photons only scatter. We show that the dust that affects the escape of Ly alpha is more restricted to the galaxies' central regions, while the larger Ly alpha halos are generated by scattering at large radii. We present an empirical modeling technique to quantify how much Ly alpha scatters in the halo, and find that this characteristic scattering distance correlates with the measured size of the Ly alpha halo. We note that there exists a slight anti-correlation between the scattering distance of Ly alpha and global dust properties.
  •  
38.
  • Bruton, Sean, et al. (författare)
  • The Impact of Cosmic Variance on Inferences of Global Neutral Fraction Derived from Lyα Luminosity Functions during Reionization
  • 2023
  • Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 953:1
  • Tidskriftsartikel (refereegranskat)abstract
    • We investigate the impact of field-to -field variation, deriving from cosmic variance, in measured Ly alpha emitter (LAE) luminosity functions (LFs) and this variation's impact on inferences of the neutral fraction of the intergalactic medium (IGM) during reionization. We post-process a z = 7 IGM simulation to populate the dark matter halos with LAEs. These LAEs have realistic UV magnitudes, Ly alpha fluxes, and Ly alpha line profiles. We calculate the attenuation of Ly alpha emission in universes with varying IGM neutral fraction, (x) over bar (H I). In a (x) over bar (H I) = 0.3 simulation, we perform 100 realizations of a mock 2 deg(2) survey with a redshift window Delta z = 0.5 and flux limit f(Ly alpha) > 1 x 10(-17)erg s(-1) cm(-2); such a survey is typical in depth and volume of the largest LAE surveys conducted today. For each realization, we compute the LAE LF and use it to recover the input x(H I). Comparing the inferred values of (x) over bar (H) (I) across the ensemble of the surveys, we find that cosmic variance, deriving from large-scale structure and variation in the neutral gas along the sightline, imposes a floor in the uncertainty of Delta(x) over bar (HI) similar to 0.2 when (x) over bar (H) (I) = 0.3. We explore mitigation strategies to decrease this uncertainty, such as increasing the volume, decreasing the flux limit, or probing the volume with many independent fields. Increasing the area and/or depth of the survey does not mitigate the uncertainty, but composing a survey with many independent fields is effective. This finding highlights the best strategy for LAE surveys aiming at constraining the (x) over bar (HI) of the universe during reionization.
  •  
39.
  • Bruton, Sean, et al. (författare)
  • The Universe is at Most 88% Neutral at z=10.6
  • 2023
  • Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 949:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent observations of GN-z11 with JWST have revealed a Ly alpha emission line with an equivalent width (EW) of 18 +/- 2 angstrom. At z = 10.6, this galaxy is expected to lie in the heart of reionization. We use a series of inhomogeneous reionization simulations to derive the distribution of the Ly alpha EW after traveling through the neutral intergalactic medium with varying average neutral gas fraction, x (H I). We use these distributions to place an upper limit of x (H I) < 0.88 at z = 10.6 at 95% confidence level. We compare our upper limit to different reionization history models, which include the recently identified enhancement at the bright end of the luminosity function at z > 8. We find that models in which faint galaxies have a higher escape fraction compared to bright galaxies are favored by the new data.
  •  
40.
  • Campbell, Matthew P, et al. (författare)
  • Toolboxes for a standardised and systematic study of glycans
  • 2014
  • Ingår i: BMC Bioinformatics. - 1471-2105. ; 15:Suppl. 1
  • Tidskriftsartikel (refereegranskat)abstract
    • Abstract Background Recent progress in method development for characterising the branched structures of complex carbohydrates has now enabled higher throughput technology. Automation of structure analysis then calls for software development since adding meaning to large data collections in reasonable time requires corresponding bioinformatics methods and tools. Current glycobioinformatics resources do cover information on the structure and function of glycans, their interaction with proteins or their enzymatic synthesis. However, this information is partial, scattered and often difficult to find to for non-glycobiologists. Methods Following our diagnosis of the causes of the slow development of glycobioinformatics, we review the "objective" difficulties encountered in defining adequate formats for representing complex entities and developing efficient analysis software. Results Various solutions already implemented and strategies defined to bridge glycobiology with different fields and integrate the heterogeneous glyco-related information are presented. Conclusions Despite the initial stage of our integrative efforts, this paper highlights the rapid expansion of glycomics, the validity of existing resources and the bright future of glycobioinformatics.
  •  
41.
  • Carson, Dean B., et al. (författare)
  • Small villages and socio-economic change in resource peripheries : a view from Northern Sweden
  • 2020
  • Ingår i: Dipping in to the North. - Singapore : Palgrave Macmillan. - 9789811566226 - 9789811566233 ; , s. 27-53
  • Bokkapitel (refereegranskat)abstract
    • Many towns and villages in the inland north of Sweden were settled by independent farmers and foresters, with industry and company towns being relatively rare. In Canada and Australia industry and company towns were more common, and there is some evidence that those towns have found it more difficult to attract and retain population than what we term here as 'settler towns'. Development of alternative economic activities such as tourism has been difficult. In Sweden, however, there is no clear distinction between the recent demographic performance of industry and settler villages, and local economic activity has been relatively unimportant as most villages are well connected to regional labour markets.
  •  
42.
  •  
43.
  • Chen, Zhishan, et al. (författare)
  • Fine-mapping analysis including over 254 000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes
  • 2024
  • Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 15:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development.
  •  
44.
  • Chisholm, J., et al. (författare)
  • The far-ultraviolet continuum slope as a Lyman Continuum escape estimator at high redshift
  • 2022
  • Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 517:4, s. 5104-5120
  • Tidskriftsartikel (refereegranskat)abstract
    • Most of the hydrogen in the intergalactic medium (IGM) was rapidly ionized at high redshifts. While observations have established that reionization occurred, observational constraints on the high-redshift ionizing emissivity remain elusive. Here, we present a new analysis of the Low-redshift Lyman Continuum Survey (LzLCS) and literature observations, a combined sample of 89 star-forming galaxies at redshifts near 0.3 with Hubble Space Telescope observations of their ionizing continua (or Lyman Continuum, LyC). We find a strong (6σ significant) inverse correlation between the continuum slope at 1550 Å (defined as Fλ ∝ λβ1550obs⁠) and both the LyC escape fraction (fesc, LyC) and fesc, LyC times the ionizing photon production efficiency (ξion). On average, galaxies with redder continuum slopes have smaller fesc, LyC than galaxies with bluer slopes mainly due to higher dust attenuation. More than 5 per cent (20 per cent) of the LyC emission escapes galaxies with β1550obs <−2.1 (−2.6). We find strong correlations between β1550obs and the [O III]/[O II] flux ratio (at 7.5σ significance), galaxy stellar mass (at 5.9σ), the gas-phase metallicity (at 4.6σ), and the observed far-ultraviolet absolute magnitude (at 3.4σ). Using previous observations of β1550obs at high redshift, we estimate the evolution of fesc, LyC with both redshift and galaxy magnitude. The LzLCS observations suggest that fainter and lower mass galaxies dominate the ionizing photon budget at higher redshift, possibly due to their rapidly evolving metal and dust content. Finally, we use our correlation between β1550obs and fesc, LyC × ξion to predict the ionizing emissivity of galaxies during the epoch of reionization. Our estimated emissivities match IGM observations, and suggest that star-forming galaxies emit sufficient LyC photons into the IGM to exceed recombinations near redshifts of 7–8.
  •  
45.
  • Clarke, Leonardo, et al. (författare)
  • An Old Stellar Population or Diffuse Nebular Continuum Emission Discovered in Green Pea Galaxies
  • 2021
  • Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 912:2
  • Tidskriftsartikel (refereegranskat)abstract
    • We use new Hubble Space Telescope (HST) images of nine Green Pea galaxies (GPGs) to study their resolved structure and color. The choice of filters, F555W and F850LP, together with the redshift of the galaxies (z ∼ 0.25), minimizes the contribution of the nebular [O iii] and Hα emission lines to the broadband images. While these galaxies are typically very blue in color, our analysis reveals that it is only the dominant stellar clusters that are blue. Each GPG does clearly show the presence of at least one bright and compact star-forming region, but these are invariably superimposed on a more extended and lower surface brightness emission. Moreover, the colors of the star-forming regions are on average bluer than those of the diffuse emission, reaching up to 0.6 magnitudes bluer. Assuming that the diffuse and compact components have constant and single-burst star formation histories, respectively, the observed colors imply that the diffuse components (possibly the host galaxy of the star formation episode) have, on average, old stellar ages (>1 Gyr), while the star clusters are younger than 500 Myr. While a redder stellar component is perhaps the most plausible explanation for these results, the limitations of our current data set lead us to examine possible alternative mechanisms, particularly recombination emission processes, which are unusually prominent in systems with such strong line emission. With the available data, however, it is not possible to distinguish between these two interpretations. A substantial presence of old stars would indicate that the mechanisms allowing large escape fractions in these local galaxies may be different from those at play during the reionization epoch.
  •  
46.
  • Conference proceedings for the Lifestyle migrationHub meeting28-29 November 2019Umeå University, Sweden : GERUM Geografisk Arbetsrapport (Working paper)
  • 2019
  • Proceedings (redaktörskap) (övrigt vetenskapligt/konstnärligt)abstract
    • Lifestyle migration refers to the relocation of citizens from affluent industrialised nations in order to find a more meaningful and relaxed life, usually in places with lower living costs and sunny or otherwise attractive climates. Often, they claim to be escaping from the “rat-race”, hectic lifestyles and pressures at work. Retirees, on the other hand, often claim to search for a more active old age by moving abroad. Scholars of lifestyle migration and tourism-informed mobilities are interested in the social conditions that lead individuals to pursue ‘the good life’ through geographic mobility and travel. Lifestyle-informed migration creates new forms of transnational community and identity. It also has important social and environmental effects on receiving communities. Studies have e.g. focused on North Europeans moving to Spain (O’Reilly 2000), or buying second homes in Malta (Åkerlund 2013), or on the migration of North Americans and West Europeans to Latin American destinations (Hayes 2015), and to South or Southeast Asia (Benson & O’Reilly 2018).
  •  
47.
  • Dao, E. Han, et al. (författare)
  • Structure of the 30S ribosomal decoding complex at ambient temperature
  • 2018
  • Ingår i: RNA. - : Cold Spring Harbor Laboratory Press (CSHL). - 1355-8382 .- 1469-9001. ; 24:12, s. 1667-1676
  • Tidskriftsartikel (refereegranskat)abstract
    • The ribosome translates nucleotide sequences of messenger RNA to proteins through selection of cognate transfer RNA according to the genetic code. To date, structural studies of ribosomal decoding complexes yielding high-resolution data have predominantly relied on experiments performed at cryogenic temperatures. New light sources like the X-ray free electron laser (XFEL) have enabled data collection from macromolecular crystals at ambient temperature. Here, we report an X-ray crystal structure of the Therm us thermophilus 30S ribosomal subunit decoding complex to 3.45 angstrom resolution using data obtained at ambient temperature at the Linac Coherent Light Source (LCLS). We find that this ambient-temperature structure is largely consistent with existing cryogenic-temperature crystal structures, with key residues of the decoding complex exhibiting similar conformations, including adenosine residues 1492 and 1493. Minor variations were observed, namely an alternate conformation of cytosine 1397 near the mRNA channel and the A-site. Our serial crystallography experiment illustrates the amenability of ribosomal microcrystals to routine structural studies at ambient temperature, thus overcoming a long-standing experimental limitation to structural studies of RNA and RNA-protein complexes at near-physiological temperatures.
  •  
48.
  • Dittenber, Benjamin, et al. (författare)
  • Accretion-driven Sources in Spatially Resolved Lyα Emitters
  • 2020
  • Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 890:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Lyα emission is a standard tracer of starburst galaxies at high redshift. However, a number of local Lyα emitters (LAEs) are X-ray sources, suggesting a possible origin of Lyα photons other than young, hot stars, and which may be active at much later ages relative to the parent starburst. Resolved, nearby LAEs offer the opportunity to discriminate between diffuse X-ray emission arising from supernova-heated gas, high-mass X-ray binaries (HMXBs), or low-luminosity active galactic nuclei (LLAGN). We examine archival X-ray imaging from Chandra and XMM-Newton for 11 galaxies with spatially resolved Lyα imaging to determine the luminosity, morphology, and spectral hardness of the X-ray sources. The data are consistent with 9 of the 12, bright Lyα sources being driven by luminous, >10(40) erg s(-1) X-ray sources. Half of the eight Chandra sources are unresolved. The data suggest that nuclear activity, whether from LLAGN or nuclear starbursts, may play an important role in Lyα emission. Our results also suggest a significant link between Lyα emission and HMXBs, ultraluminous X-ray sources, and/or LLAGN, which would imply that Lyα may be generated over timescales 1-2 orders of magnitude longer than produced by photoionization from OB stars. This highlights a critical need to quantify the relative contributions of different sources across cosmic time, to interpret Lyα observations and the resulting properties of distant galaxies.
  •  
49.
  •  
50.
  • Duval, Florent, et al. (författare)
  • The Lyman alpha reference sample VI. Lyman alpha escape from the edge-on disk galaxy Mrk 1486
  • 2016
  • Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 587
  • Tidskriftsartikel (refereegranskat)abstract
    • Context. Recent numerical simulations suggest that the strength of the Lyman alpha (Ly alpha) line of star-forming disk galaxies strongly depends on the inclination at which they are observed: from edge-on to face-on, we expect to see a change from a strongly attenuated Ly alpha line to a strong Ly alpha emission line.Aims. We aim to understand how a strong Ly alpha emission line is able to escape from the low-redshift highly inclined (edge-on) disk galaxy Mrk 1486 (z similar to 0.0338). To our knowledge, this work is the first observational study of Ly alpha transport inside an edge-on disk galaxy.Methods. Using a large set of HST imaging and spectroscopic data, we investigated the interstellar medium (ISM) structure and the dominant source of Ly alpha radiation inside Mrk 1486. Moreover, using a 3D Monte Carlo Ly alpha radiation transfer code, we studied the radiative transfer of Ly alpha and UV continuum photons inside a 3D geometry of neutral hydrogen (HI) and dust that models the ISM structure at the galaxy center. Our numerical simulations predicted the Ly alpha line profile that we then compared to the one observed in the HST/COS spectrum of Mrk 1486.Results. While a pronounced Ly alpha absorption line emerges from the disk of Mrk 1486, very extended Ly alpha structures are observed at large radii from the galaxy center: a large Ly alpha-halo and two very bright Ly alpha regions located slightly above and below the disk plane. The analysis of IFU H alpha spectroscopic data of Mrk 1486 indicates the presence of two bipolar outflowing halos of HI gas at the same location as these two bright Ly alpha regions. Comparing different diagnostic diagrams (such as [OIII](5007)/H beta versus [OI](6300)/H alpha) to photo-and shock-ionization models, we find that the Ly alpha production of Mrk 1486 is dominated by photoionization inside the galaxy disk. From this perspective, our numerical simulations succeed in reproducing the strength and shape of the observed Ly alpha emission line of Mrk 1486 by assuming a scenario in which the Ly alpha photons are produced inside the galaxy disk, travel along the outflowing halos, and scatter on cool HI materials toward the observer.Conclusions. Extended bipolar galactic winds are frequently observed from star-forming disk galaxies. Given the advantage Ly alpha photons take of such outflowing HI materials to easily escape from Mrk 1486, this mechanism may explain the origin of strong Ly alpha emission lines frequently observed from highly inclined galaxies at high-redshift. This therefore challenges the robustness of the expected viewing-angle effect on the Ly alpha properties of star-forming disk galaxies.
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