Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Publication Date: 2015-05-09
    Description: Magnetized rocks can record the history of the magnetic field of a planet, a key constraint for understanding its evolution. From orbital vector magnetic field measurements of Mercury taken by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft at altitudes below 150 kilometers, we have detected remanent magnetization in Mercury's crust. We infer a lower bound on the average age of magnetization of 3.7 to 3.9 billion years. Our findings indicate that a global magnetic field driven by dynamo processes in the fluid outer core operated early in Mercury's history. Ancient field strengths that range from those similar to Mercury's present dipole field to Earth-like values are consistent with the magnetic field observations and with the low iron content of Mercury's crust inferred from MESSENGER elemental composition data.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Johnson, Catherine L -- Phillips, Roger J -- Purucker, Michael E -- Anderson, Brian J -- Byrne, Paul K -- Denevi, Brett W -- Feinberg, Joshua M -- Hauck, Steven A 2nd -- Head, James W 3rd -- Korth, Haje -- James, Peter B -- Mazarico, Erwan -- Neumann, Gregory A -- Philpott, Lydia C -- Siegler, Matthew A -- Tsyganenko, Nikolai A -- Solomon, Sean C -- New York, N.Y. -- Science. 2015 May 22;348(6237):892-5. doi: 10.1126/science.aaa8720. Epub 2015 May 7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. Planetary Science Institute, Tucson, AZ 85719, USA. cjohnson@eos.ubc.ca. ; Planetary Science Directorate, Southwest Research Institute, Boulder, CO 80302, USA. ; NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. ; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. ; Lunar and Planetary Institute, Houston, TX 77058, USA. Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA. ; Institute for Rock Magnetism, Department of Earth Sciences, University of Minnesota, Minneapolis, MN, 55455, USA. ; Department of Earth, Environmental, and Planetary Sciences, Case Western Reserve University, Cleveland, OH, 44106, USA. ; Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA. ; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA. ; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada. ; Planetary Science Institute, Tucson, AZ 85719, USA. Department of Earth Sciences, Southern Methodist University, Dallas, TX 75205, USA. ; Institute and Faculty of Physics, Saint Petersburg State University, Saint Petersburg, Russia. ; Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA. Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25953822" target="_blank"〉PubMed〈/a〉
    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 ...
  • 2
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Transcutaneous measurements of pO2 and pCO2 were made on the forearm skin after intradermal injection of histamine, PGE2, and saline. The mediators, used at concentrations which induce intense hyperaemia, did not modify the steady state tcpO2/pCO2 levels measured with a sensor head temperature of 44°C when breathing air or hyperbaric (2ATA) oxygen. It was deduced that gas transport is unaffected by mediator-induced conditions in the skin. The rates of fall of tcpO2 and of rise of tcpCO2 after arresting the forearm circulation by cuff occlusion of the arm were significantly less at the histamine site than at the PGE2 and saline sites. The values over the PGE2 and saline injection sites were less than those over undisturbed skin. The dynamic tests of respiratory gas exchange indicate that the skin metabolic rate is reduced at all injection sites and the greatest effect was seen with histamine. Measurement of dermal thickness after saline injection has shown that the excess interstitial fluid persists at the time of maximal hyperaemia: this is further accentuated at the histamine site through active oedema formation. Accumulation of excess intestitial fluid (persistence of aqueous injection or oedema generated by the action of mediator) separates the tissue cells. The reduction in the number of cells per unit volume is sufficient to explain the observed reduction in oxygen consumption per unit volume of skin. It is concluded that the increased diffusional distances in mediator-induced oedema are unimportant for the respiration of otherwise normal tissues, but that oedema by reducing oxygen flux may contribute appreciably to the hypoxia of inflammed tissue infiltrated with metabolically active cells.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Seasonal changes observed on the surface of Mars can in part be attributed to the transport of geological materials by wind. Images obtained by orbiting spacecraft in the 1970s showed large wind-formed features such as dunes, and revealed regional time-varying albedos that could be attributed ...
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Polar processes can be sensitive indicators of global climate, and the geological features associated with polar ice caps can therefore indicate evolution of climate with time. The polar regions on Mars have distinctive morphologic and climatologic features: thick layered deposits, ...
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...