50 research outputs found

    Fitting the integrated Spectral Energy Distributions of Galaxies

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    Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc

    PRILOG POZNAVANJU KLIME SISKA

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    Sažetak - Rad predstavlja analizu statističkih parametara i pokazatelja klime za Sisak, navedenih u više prethodnih radova i studija klime Siska za pojedina kraća iz ukupnog 35-godišnjeg razdoblja (1948-1982) povezujući i objedinjujući rezultate u jednu cjelinu. Sisačko se područje po općem klimatskom obilježju uklapa u podneblje srednjo-europskih umjerenih širina. U nekim pokazateljima klime blago se ističe maritimnost, a u drugim kontinentalnost klime, ali niti jedno od tih obilježja ne prevladava bitno. Vremenske slike nekih klimatskih elemenata sadrže trendove zapažene u širem sisačkom području u tom razdoblju (temperatura zraka), kao i trendove pretežno lokalnog obilježja (naoblaka). Posebnost sisačkog podneblja ističe se osobito u sustavu prizemnog strujanja zraka, u kojemu 80% slučajeva pripada tišinama i vrlo slabim vjetrovima (do 2 B). Pri tom se osim sjeveroistočnjaka i jugozapadnjaka, koji prevladavaju u većem dijelu zapadne Hrvatske, pojavljuje i jugoistočnjak kao lokalno obilježje sustava strujanja zraka u Sisku. Rad sadrži i komparativnu analizu klimatskih paramelara bližeg i daljeg okolnog područja Siska te opis tipa klime na temelju više klimatskih i bioklimatskih kiterija. U radu se upozorava na pitanja koja su ostala otvorena za daljnja istraživanja na temelju duljeg niza i ulazeći u izvorne podatke

    The Iso2k Database: A global compilation of paleo-δ18O and δ2H records to aid understanding of Common Era climate

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    Reconstructions of global hydroclimate during the Common Era (CE; the past ~ 2000 years) are important for providing context for current and future global environmental change. Stable isotope ratios in water are quantitative indicators of hydroclimate on regional to global scales, and these signals are encoded in a wide range of natural geologic archives. Here we present the Iso2k database, a global compilation of previously published datasets from a variety of natural archives that record the stable oxygen (δ18O) or hydrogen (δ2H) isotopic composition of environmental waters, which reflect hydroclimate changes over the CE. The Iso2k database contains 756 isotope records from the terrestrial and marine realms, including: glacier and ground ice (205); speleothems (68); corals, sclerosponges, and mollusks (145); wood (81); lake sediments and other terrestrial sediments (e.g., loess) (158); and marine sediments (99). Individual datasets have temporal resolutions ranging from sub-annual to centennial, and include chronological data where available. A fundamental feature of the database is its comprehensive metadata, which will assist both experts and non-experts in the interpretation of each record and in data synthesis. Key metadata fields have standardized vocabularies to facilitate comparisons across diverse archives and with climate model simulated fields. This is the first global-scale collection of water isotope proxy records from multiple types of geological and biological archives. It is suitable for evaluating hydroclimate processes through time and space using large-scale synthesis, model-data intercomparison and (paleo)data assimilation. The Iso2k database is available for download at: https://doi.org/10.6084/m9.figshare.11553162 (McKay and Konecky, 2020)

    The Eighteenth Data Release of the Sloan Digital Sky Surveys: Targeting and First Spectra from SDSS-V

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    The eighteenth data release of the Sloan Digital Sky Surveys (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs, or "Mappers": Milky Way Mapper (MWM), Black Hole Mapper (BHM), and Local Volume Mapper (LVM). This data release contains extensive targeting information for the two multi-object spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration- and scientifically-focused components. DR18 also includes ~25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.Comment: Accepted to ApJ

    The eighteenth data release of the Sloan Digital Sky Surveys : targeting and first spectra from SDSS-V

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    The eighteenth data release of the Sloan Digital Sky Surveys (SDSS) is the first one for SDSS-V, the fifth generation of the survey. SDSS-V comprises three primary scientific programs, or "Mappers": Milky Way Mapper (MWM), Black Hole Mapper (BHM), and Local Volume Mapper (LVM). This data release contains extensive targeting information for the two multi-object spectroscopy programs (MWM and BHM), including input catalogs and selection functions for their numerous scientific objectives. We describe the production of the targeting databases and their calibration- and scientifically-focused components. DR18 also includes ~25,000 new SDSS spectra and supplemental information for X-ray sources identified by eROSITA in its eFEDS field. We present updates to some of the SDSS software pipelines and preview changes anticipated for DR19. We also describe three value-added catalogs (VACs) based on SDSS-IV data that have been published since DR17, and one VAC based on the SDSS-V data in the eFEDS field.Publisher PDFPeer reviewe

    The Iso2k database: a global compilation of paleo-δ18O and δ2H records to aid understanding of common era climate

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    Reconstructions of global hydroclimate during the Common Era (CE; the past ~2,000 years) are important for providing context for current and future global environmental change. Stable isotope ratios in water are quantitative indicators of hydroclimate on regional to global scales, and these signals are encoded in a wide range of natural geologic archives. Here we present the Iso2k database, a global compilation of previously published datasets from a variety of natural archives that record the stable oxygen (δ18O) or hydrogen (δ²H) isotopic composition of environmental waters, which reflect hydroclimate changes over the CE. The Iso2k database contains 756 isotope records from the terrestrial and marine realms, including: glacier and ground ice (205); speleothems (68); corals, sclerosponges, and mollusks (145); wood (81); lake sediments and other terrestrial sediments (e.g., loess) (158); and marine sediments (99). Individual datasets have temporal resolutions ranging from sub-annual to centennial, and include chronological data where available. A fundamental feature of the database is its comprehensive metadata, which will assist both experts and non-experts in the interpretation of each record and in data synthesis. Key metadata fields have standardized vocabularies to facilitate comparisons across diverse archives and with climate model simulated fields. This is the first global-scale collection of water isotope proxy records from multiple types of geological and biological archives. It is suitable for evaluating hydroclimate processes through time and space using large-scale synthesis, model-data intercomparison and (paleo)data assimilation. The Iso2k database is available for download at: https://doi.org/10.25921/57j8-vs18 (Konecky and McKay, 2020) and is also accessible via through the NOAA/WDS Paleo Data landing page: https://www.ncdc.noaa.gov/paleo/study/29593

    Azathioprine for refractory ulcerative proctitis: A retrospective multicenter study

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    International audienceBACKGROUND: Efficacy of azathioprine (AZA) in refractory ulcerative proctitis (UP) is unknown.METHODS: All patients treated with AZA for refractory UP in three referral centers between 2002 and 2012 were included. "Treatment success" in the long-term was defined as the absence of colectomy during follow-up, no need for anti-TNF during follow-up, no ongoing systemic steroids use, no adverse event leading to AZA withdrawal, and clinically quiescent disease at last follow-up.RESULTS: Of the 1279 adult patients with ulcerative colitis, 25 patients were treated with AZA for refractory UP (median disease duration 4.9 years). Of these, 4 had no short-term clinical assessment. Of the remaining 21, 4 were primary non responders to AZA, 7 discontinued AZA for adverse events and 10 showed clinical improvement. At the long-term assessment at last follow up after a median of 46 months, 5 patients had treatment success and were still on AZA treatment, the remaining 20 were treatment failures. Of these, 5 discontinued AZA for adverse events and 15 were treated with infliximab (clinical response in 11 patients, primary non-response in one patient, and 3 underwent colectomy).CONCLUSION: AZA may be efficacious in maintaining clinical response in one-fifth of patients with refractory UP in a real-life setting

    Rectal cancer: French Intergroup clinical practice guidelines for diagnosis, treatments and follow-up (SNFGE, FFCD, GERCOR, UNICANCER, SFCD, SFED, SFRO)

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    IF 3.061International audienceIntroductionThis document is a summary of the French Intergroup guidelines regarding the management of rectal adenocarcinoma published in February 2016.MethodThis collaborative work, under the auspices of most of the French medical societies involved in the management of rectal cancer, is based on the previous guidelines published in 2013. Recommendations are graded into 3 categories according to the level of evidence of data found in the literature.ResultsIn agreement with the ESMO guidelines (2013), non-metastatic rectal cancers have been stratified in 4 risk groups according to endoscopy, MRI or endorectal-ultrasonography. Locally-advanced tumors are limited to groups 3 and 4 (T3 ≥4 cm or T3c–d or N1-2 or T4). These tumors are usually treated using neoadjuvant treatment and total proctectomy (TME). Adjuvant treatment depends on the pathological findings. Very early (group 1) or early (group 2) tumors are managed mainly by surgery, and organ preservation may be an option in selected cases. For metastatic tumors, the recommendations are based on less robust evidence and chemotherapy plays a major role.ConclusionSuch recommendations are constantly being optimized and each individual case must be discussed within a Multi-Disciplinary Team
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