1,445 research outputs found

    The ALMA-ALPINE [CII] survey: Kennicutt-Schmidt relation in four massive main-sequence galaxies at z~4.5

    Full text link
    The Kennicutt-Schmidt (KS) relation between the gas and the star formation rate (SFR) surface density (Σgas\Sigma_{\rm gas}-ΣSFR\Sigma_{\rm SFR}) is essential to understand star formation processes in galaxies. So far, it has been measured up to z~2.5 in main-sequence galaxies. In this letter, we aim to put constraints at z~4.5 using a sample of four massive main-sequence galaxies observed by ALMA at high resolution. We obtained ~0.3"-resolution [CII] and continuum maps of our objects, which we then converted into gas and obscured SFR surface density maps. In addition, we produced unobscured SFR surface density maps by convolving Hubble ancillary data in the rest-frame UV. We then derived the average ΣSFR\Sigma_{\rm SFR} in various Σgas\Sigma_{\rm gas} bins, and estimated the uncertainties using a Monte Carlo sampling. Our galaxy sample follows the KS relation measured in main-sequence galaxies at lower redshift and is slightly lower than predictions from simulations. Our data points probe the high end both in terms of Σgas\Sigma_{\rm gas} and Σgas\Sigma_{\rm gas}, and gas depletion timescales (285-843 Myr) remain similar to z~2 objects. However, three of our objects are clearly morphologically disturbed, and we could have expected shorter gas depletion timescales (~100 Myr) similar to merger-driven starbursts at lower redshifts. This suggests that the mechanisms triggering starbursts at high redshift may be different than in the low- and intermediate-z Universe.Comment: 9 pages, 7 figures, 2 tables, accepted by A&A (letter

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

    Get PDF
    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

    Get PDF
    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

    Get PDF
    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Upcycling spent brewery grains through the production of carbon adsorbents: application to the removal of carbamazepine from water

    Get PDF
    Spent brewery grains, a by-product of the brewing process, were used as precursor of biochars and activated carbons to be applied to the removal of pharmaceuticals from water. Biochars were obtained by pyrolysis of the raw materials, while activated carbons were produced by adding a previous chemical activation step. The influence of using different precursors (from distinct fermentation processes), activating agents (potassium hydroxide, sodium hydroxide, and phosphoric acid), pyrolysis temperatures, and residence times was assessed. The adsorbents were physicochemically characterized and applied to the removal of the antiepileptic carbamazepine from water. Potassium hydroxide activation produced the materials with the most promising properties and adsorptive removals, with specific surface areas up to 1120 m2 g-1 and maximum adsorption capacities up to 190 ± 27 mg g-1 in ultrapure water. The adsorption capacity suffered a reduction of < 70% in wastewater, allowing to evaluate the impact of realistic matrices on the efficiency of the materials.publishe

    Borrelia burgdorferi EbfC defines a newly-identified, widespread family of bacterial DNA-binding proteins

    Get PDF
    The Lyme disease spirochete, Borrelia burgdorferi, encodes a novel type of DNA-binding protein named EbfC. Orthologs of EbfC are encoded by a wide range of bacterial species, so characterization of the borrelial protein has implications that span the eubacterial kingdom. The present work defines the DNA sequence required for high-affinity binding by EbfC to be the 4 bp broken palindrome GTnAC, where ‘n’ can be any nucleotide. Two high-affinity EbfC-binding sites are located immediately 5′ of B. burgdorferi erp transcriptional promoters, and binding of EbfC was found to alter the conformation of erp promoter DNA. Consensus EbfC-binding sites are abundantly distributed throughout the B. burgdorferi genome, occurring approximately once every 1 kb. These and other features of EbfC suggest that this small protein and its orthologs may represent a distinctive type of bacterial nucleoid-associated protein. EbfC was shown to bind DNA as a homodimer, and site-directed mutagenesis studies indicated that EbfC and its orthologs appear to bind DNA via a novel α-helical ‘tweezer’-like structure

    VITA-D: Cholecalciferol substitution in vitamin D deficient kidney transplant recipients: A randomized, placebo-controlled study to evaluate the post-transplant outcome

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Vitamin D does not only regulate calcium homeostasis but also plays an important role as an immune modulator. It influences the immune system through the induction of immune shifts and regulatory cells resulting in immunologic tolerance. As such, vitamin D is thought to exert beneficial effects within the transplant setting, especially in kidney transplant recipients, considering the high prevalence of vitamin D deficiency in kidney transplant recipients.</p> <p>Methods/Design</p> <p>The VITA-D study, a randomized, placebo-controlled, double-blind study with two parallel groups including a total of 200 kidney transplant recipients, is designed to investigate the immunomodulatory and renoprotective effects of cholecalciferol (vitamin D<sub>3</sub>) within the transplant setting. Kidney transplant recipients found to have vitamin D deficiency defined as 25-hydroxyvitamin D<sub>3 </sub>< 50 nmol per liter will be randomly assigned to receive either oral cholecalciferol therapy or placebo and will be followed for one year. Cholecalciferol will be administered at a dose of 6800 International Units daily over a time period of one year.</p> <p>The objective is to evaluate the influence of vitamin D<sub>3 </sub>substitution in vitamin D deficient kidney transplant recipients on the post-transplant outcome. As a primary endpoint glomerular filtration rate calculated with the MDRD formula (modification of diet in renal disease) one year after kidney transplantation will be evaluated. Incidence of acute rejection episodes, and the number and severity of infections (analyzed by means of C-reactive protein) within the first year after transplantation will be monitored as well. As a secondary endpoint the influence of vitamin D<sub>3 </sub>on bone mineral density within the first year post-transplant will be assessed. Three DXA analyses will be performed, one within the first four weeks post-transplant, one five months and one twelve months after kidney transplantation.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov NCT00752401</p

    Dusty Starbursts Masquerading as Ultra-high Redshift Galaxies in JWST CEERS Observations

    Get PDF
    corecore