Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

  • 1
    Publication Date: 2013-10-18
    Description: Super-luminous supernovae that radiate more than 10(44) ergs per second at their peak luminosity have recently been discovered in faint galaxies at redshifts of 0.1-4. Some evolve slowly, resembling models of 'pair-instability' supernovae. Such models involve stars with original masses 140-260 times that of the Sun that now have carbon-oxygen cores of 65-130 solar masses. In these stars, the photons that prevent gravitational collapse are converted to electron-positron pairs, causing rapid contraction and thermonuclear explosions. Many solar masses of (56)Ni are synthesized; this isotope decays to (56)Fe via (56)Co, powering bright light curves. Such massive progenitors are expected to have formed from metal-poor gas in the early Universe. Recently, supernova 2007bi in a galaxy at redshift 0.127 (about 12 billion years after the Big Bang) with a metallicity one-third that of the Sun was observed to look like a fading pair-instability supernova. Here we report observations of two slow-to-fade super-luminous supernovae that show relatively fast rise times and blue colours, which are incompatible with pair-instability models. Their late-time light-curve and spectral similarities to supernova 2007bi call the nature of that event into question. Our early spectra closely resemble typical fast-declining super-luminous supernovae, which are not powered by radioactivity. Modelling our observations with 10-16 solar masses of magnetar-energized ejecta demonstrates the possibility of a common explosion mechanism. The lack of unambiguous nearby pair-instability events suggests that their local rate of occurrence is less than 6 x 10(-6) times that of the core-collapse rate.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nicholl, M -- Smartt, S J -- Jerkstrand, A -- Inserra, C -- McCrum, M -- Kotak, R -- Fraser, M -- Wright, D -- Chen, T-W -- Smith, K -- Young, D R -- Sim, S A -- Valenti, S -- Howell, D A -- Bresolin, F -- Kudritzki, R P -- Tonry, J L -- Huber, M E -- Rest, A -- Pastorello, A -- Tomasella, L -- Cappellaro, E -- Benetti, S -- Mattila, S -- Kankare, E -- Kangas, T -- Leloudas, G -- Sollerman, J -- Taddia, F -- Berger, E -- Chornock, R -- Narayan, G -- Stubbs, C W -- Foley, R J -- Lunnan, R -- Soderberg, A -- Sanders, N -- Milisavljevic, D -- Margutti, R -- Kirshner, R P -- Elias-Rosa, N -- Morales-Garoffolo, A -- Taubenberger, S -- Botticella, M T -- Gezari, S -- Urata, Y -- Rodney, S -- Riess, A G -- Scolnic, D -- Wood-Vasey, W M -- Burgett, W S -- Chambers, K -- Flewelling, H A -- Magnier, E A -- Kaiser, N -- Metcalfe, N -- Morgan, J -- Price, P A -- Sweeney, W -- Waters, C -- England -- Nature. 2013 Oct 17;502(7471):346-9. doi: 10.1038/nature12569.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="" target="_blank"〉PubMed〈/a〉
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2013-08-10
    Description: Consistent, high-level, vaccine-induced protection against human malaria has only been achieved by inoculation of Plasmodium falciparum (Pf) sporozoites (SPZ) by mosquito bites. We report that the PfSPZ Vaccine--composed of attenuated, aseptic, purified, cryopreserved PfSPZ--was safe and well tolerated when administered four to six times intravenously (IV) to 40 adults. Zero of six subjects receiving five doses and three of nine subjects receiving four doses of 1.35 x 10(5) PfSPZ Vaccine and five of six nonvaccinated controls developed malaria after controlled human malaria infection (P = 0.015 in the five-dose group and P = 0.028 for overall, both versus controls). PfSPZ-specific antibody and T cell responses were dose-dependent. These data indicate that there is a dose-dependent immunological threshold for establishing high-level protection against malaria that can be achieved with IV administration of a vaccine that is safe and meets regulatory standards.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Seder, Robert A -- Chang, Lee-Jah -- Enama, Mary E -- Zephir, Kathryn L -- Sarwar, Uzma N -- Gordon, Ingelise J -- Holman, LaSonji A -- James, Eric R -- Billingsley, Peter F -- Gunasekera, Anusha -- Richman, Adam -- Chakravarty, Sumana -- Manoj, Anita -- Velmurugan, Soundarapandian -- Li, MingLin -- Ruben, Adam J -- Li, Tao -- Eappen, Abraham G -- Stafford, Richard E -- Plummer, Sarah H -- Hendel, Cynthia S -- Novik, Laura -- Costner, Pamela J M -- Mendoza, Floreliz H -- Saunders, Jamie G -- Nason, Martha C -- Richardson, Jason H -- Murphy, Jittawadee -- Davidson, Silas A -- Richie, Thomas L -- Sedegah, Martha -- Sutamihardja, Awalludin -- Fahle, Gary A -- Lyke, Kirsten E -- Laurens, Matthew B -- Roederer, Mario -- Tewari, Kavita -- Epstein, Judith E -- Sim, B Kim Lee -- Ledgerwood, Julie E -- Graham, Barney S -- Hoffman, Stephen L -- VRC 312 Study Team -- 3R44AI055229-06S1/AI/NIAID NIH HHS/ -- 4R44AI055229-08/AI/NIAID NIH HHS/ -- 5R44AI058499-05/AI/NIAID NIH HHS/ -- N01-AI-40096/AI/NIAID NIH HHS/ -- Intramural NIH HHS/ -- Howard Hughes Medical Institute/ -- New York, N.Y. -- Science. 2013 Sep 20;341(6152):1359-65. doi: 10.1126/science.1241800. Epub 2013 Aug 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20852, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="" target="_blank"〉PubMed〈/a〉
    Keywords: Administration, Intravenous ; Adult ; Animals ; Cytokines/immunology ; Female ; Humans ; Immunity, Cellular ; Malaria Vaccines/*administration & dosage/adverse effects/*immunology ; Malaria, Falciparum/*prevention & control ; Male ; Mice ; Plasmodium falciparum/*immunology ; Sporozoites/immunology ; T-Lymphocytes/immunology ; Vaccination/adverse effects/methods
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...