LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 15

Search options

  1. Article ; Online: Evidence for deep-water production in the North Pacific Ocean during the early Cenozoic warm interval.

    Thomas, Deborah J

    Nature

    2004  Volume 430, Issue 6995, Page(s) 65–68

    Abstract: The deep-ocean circulation is responsible for a significant component of global heat transport. In the present mode of circulation, deep waters form in the North Atlantic and Southern oceans where surface water becomes sufficiently cold and dense to sink. ...

    Abstract The deep-ocean circulation is responsible for a significant component of global heat transport. In the present mode of circulation, deep waters form in the North Atlantic and Southern oceans where surface water becomes sufficiently cold and dense to sink. Polar temperatures during the warmest climatic interval of the Cenozoic era (approximately 65 to 40 million years (Myr) ago) were significantly warmer than today, and this may have been a consequence of enhanced oceanic heat transport. However, understanding the relationship between deep-ocean circulation and ancient climate is complicated by differences in oceanic gateways, which affect where deep waters form and how they circulate. Here I report records of neodymium isotopes from two cores in the Pacific Ocean that indicate a shift in deep-water production from the Southern Ocean to the North Pacific approximately 65 Myr ago. The source of deep waters reverted back to the Southern Ocean 40 Myr ago. The relative timing of changes in the neodymium and oxygen isotope records indicates that changes in Cenozoic deep-water circulation patterns were the consequence, not the cause, of extreme Cenozoic warmth.
    MeSH term(s) Animals ; Bone and Bones/chemistry ; Fishes ; Fossils ; Greenhouse Effect ; Neodymium ; Oceans and Seas ; Oxygen Isotopes ; Pacific Ocean ; Rain ; Seawater/chemistry ; Temperature ; Time Factors ; Tooth/chemistry ; Tropical Climate ; Water Movements
    Chemical Substances Oxygen Isotopes ; Neodymium (2I87U3734A)
    Language English
    Publishing date 2004-07-01
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 120714-3
    ISSN 1476-4687 ; 0028-0836
    ISSN (online) 1476-4687
    ISSN 0028-0836
    DOI 10.1038/nature02639
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 26: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)
    Zs.MG 9: Show issues
    Zs.MO 244: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  2. Article: Geographically different oceanographic responses to global warming during the Cenomanian–Turonian interval and Oceanic Anoxic Event 2

    Thomas, Deborah J / David S. Tilghman

    Palaeogeography, palaeoclimatology, palaeoecology. 2014 Oct. 01, v. 411

    2014  

    Abstract: Oceanic Anoxic Event (OAE) 2 coincided with the Cenomanian–Turonian boundary ~93.9Ma, and was one of the two most prominent and globally significant of the major mid-Cretaceous OAEs. A confluence of global warming, major large igneous province ... ...

    Abstract Oceanic Anoxic Event (OAE) 2 coincided with the Cenomanian–Turonian boundary ~93.9Ma, and was one of the two most prominent and globally significant of the major mid-Cretaceous OAEs. A confluence of global warming, major large igneous province volcanism, and intensified hydrologic cycling preconditioned the earth system for widespread preservation of organic matter during OAE2; however the ultimate necessary ingredient was enhanced nutrient availability in oceanic surface waters. Here we present new Cenomanian–Turonian interval seawater Neodymium isotope data from the proto-Indian Ocean that demonstrates increased water column stratification during the pre- and post-OAE2 interval, punctuated by a transient decrease in this stratification immediately prior to the onset of OAE2 recorded at Ocean Drilling Program Site 763. The direct oceanographic responses to climate change on both longer- and short-term time scales observed in this region are distinct from those recorded in the northern, tropical and southern Atlantic basins. The transient de-stratification of the water column in the eastern proto-Indian Ocean likely did not contribute to the accumulation of organic-rich sediments in the region, indicating that weathering and/or hydrothermal inputs promoted enhanced surface water nutrient levels and hence primary productivity.
    Keywords basins ; drilling ; global warming ; ingredients ; isotopes ; neodymium ; nutrient availability ; organic matter ; primary productivity ; seawater ; sediments ; surface water ; volcanic activity ; weathering
    Language English
    Dates of publication 2014-1001
    Size p. 136-143.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 417718-6
    ISSN 0031-0182
    ISSN 0031-0182
    DOI 10.1016/j.palaeo.2014.06.014
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 67/162: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article: Thorium-derived dust fluxes to the tropical Pacific Ocean, 58Ma

    Woodard, Stella C / Thomas, Deborah J / Marcantonio, Franco

    Geochimica et cosmochimica acta. 2012 June 15, v. 87

    2012  

    Abstract: Eolian dust in pelagic deep sea sediments can be used to reconstruct ancient wind patterns and paleoenvironmental response to climate change. Traditional methods to determine dust accumulation involve isolating the non-dissolvable aluminosilicate ... ...

    Abstract Eolian dust in pelagic deep sea sediments can be used to reconstruct ancient wind patterns and paleoenvironmental response to climate change. Traditional methods to determine dust accumulation involve isolating the non-dissolvable aluminosilicate minerals from deep sea sediments through a series of chemical leaches, but cannot differentiate between minerals from eolian, authigenic and volcanogenic sources. Other geochemical proxies, such as sedimentary ²³²Th and crustal ⁴He content, have been used to construct high-resolution records of atmospheric dust fluxes to the deep sea during the Quaternary. Here we use sedimentary Th content as a proxy for terrigenous material (eolian dust) in ∼58Myr-old sediments from the Shatsky Rise (ODP Site 1209) and compare our results with previous dust estimates generated using the traditional chemical extraction method and sedimentary ⁴Hecᵣᵤₛₜₐₗ concentrations. We find excellent agreement between Th-based dust estimates and those generated using the traditional method. In addition our results show a correlation between sedimentary Th and ⁴Hecᵣᵤₛₜₐₗ content, which suggests a source older than present day Asian loess supplied dust to the central subtropical Pacific Ocean during the early Paleogene.
    Keywords climate change ; loess ; minerals ; wind ; Pacific Ocean
    Language English
    Dates of publication 2012-0615
    Size p. 194-209.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 300305-x
    ISSN 0016-7037
    ISSN 0016-7037
    DOI 10.1016/j.gca.2012.03.035
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    In stock of ZB MED Bonn / Germany

    Z 2000/701: Show issues

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  4. Book ; Online: Sedimentary records of ODP Site 198-1209 on Shatsky Rise, supplementary data to: Woodard, Stella C; Thomas, Deborah J; Hovan, Steven A; Röhl, Ursula; Westerhold, Thomas (2011): Evidence for orbital forcing of dust accumulation during the early Paleogene Greenhouse. Geochemistry Geophysics Geosystems, 12, Q02007

    Woodard, Stella C / Hovan, Steven A / Röhl, Ursula / Thomas, Deborah J / Westerhold, Thomas

    2011  

    Abstract: The accumulation of wind blown (eolian) dust in deep-sea sediments reflects the aridity/humidity conditions of the continental region supplying the dust, as well as the "gustiness" of the climate system. Detailed studies of Pleistocene glacial- ... ...

    Abstract The accumulation of wind blown (eolian) dust in deep-sea sediments reflects the aridity/humidity conditions of the continental region supplying the dust, as well as the "gustiness" of the climate system. Detailed studies of Pleistocene glacial-interglacial dust fluxes suggest changes in accumulation rates corresponding to orbital variations in solar insolation (Milankovitch cycles). While the orbital cycles found in sedimentary archives of the Pleistocene are intricately related to glacial growth and decay, similar global orbital signals recognized in deep-sea sediments of early Paleogene age, the last major greenhouse interval ~65-45 million years ago, could not have been linked to the waxing and waning of large ice sheets. Thus orbital signals recorded in early Paleogene sediments must reflect some other climate response to changes in solar insolation. To explore the potential connection between orbital forcing and the climate processes that control dust accumulation, we generated a high-resolution dust record for ~58 Myr old sediments from Shatsky Rise (ODP Site 1209, paleolatitude ~15°N-20°N). The dust accumulation data provide the first evidence of a correlation between dust flux to the deep sea and orbital cyclicity during the early Paleogene, indicating dust supply responded to insolation forcing during the last major interval of greenhouse climate. Furthermore, the relative amplitude of the dust flux response during the early Paleogene greenhouse was comparable to that during icehouse climates. Thus, subtle variations in solar insolation driven by changes in Earth's orbit about the Sun may have had a similar impact on climate during intervals of overall warmth as they did during glacial-interglacial states.
    Language English
    Dates of publication 2011-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1029/2010GC003394
    DOI 10.1594/PANGAEA.757701
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  5. Book ; Online: Nd isotope data for ODP Leg 208 holes, supplementary data to: Via, Rachael K; Thomas, Deborah J (2006): Evolution of Atlantic thermohaline circulation: Early Oligocene onset of deep-water production in the North Atlantic. Geology 2006, 34(6), 441-444

    Via, Rachael K / Thomas, Deborah J

    2006  

    Abstract: The flow of deep-water masses is a key component of heat transport in the modern climate system, yet the role of deep-ocean heat transport during periods of extreme warmth is poorly understood. The present mode of meridional overturning circulation is ... ...

    Abstract The flow of deep-water masses is a key component of heat transport in the modern climate system, yet the role of deep-ocean heat transport during periods of extreme warmth is poorly understood. The present mode of meridional overturning circulation is characterized by deep-water formation in both the North Atlantic and the Southern Ocean. However, a different mode of meridional overturning circulation operated during the extreme greenhouse warmth of the early Cenozoic, during which time the Southern Ocean was the dominant region of deep-water formation. The combination of general global cooling and tectonic evolution of the Atlantic basins over the past ~55 m.y. ultimately led to the development of a mode of overturning circulation characterized by both Southern Ocean and North Atlantic deep-water sources. The change in deep-water circulation mode may, in turn, have affected global climate; however, unraveling the causes and consequences of this transition requires a better understanding of the timing of the transition. New Nd isotope data from the southeastern Atlantic Ocean indicate that the initial transition to a bipolar mode of deep-water circulation occurred in the early Oligocene, ca. 33 Ma. The likely cause of significant deep-water production in the North Atlantic was tectonic deepening of the sill separating the Greenland-Norwegian Sea from the North Atlantic.
    Language English
    Dates of publication 2006-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1130/G22545.1
    DOI 10.1594/PANGAEA.724682
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  6. Book ; Online: Age model and elemental data of DSDP Holes 48-401 and 80-549, supplementary data to: Thomas, Deborah J; Bralower, Timothy J (2005): Sedimentary trace element constraints on the role of North Atlantic Igneous Province volcanism in late Paleocene-early Eocene environmental change. Marine Geology, 217(3-4, 233-254

    Thomas, Deborah J / Bralower, Timothy J

    2005  

    Abstract: A growing body of geologic evidence suggests that emplacement of the North Atlantic Igneous Province (NAIP) played a major role in global warming during the early Paleogene as well as in the transient Paleocene-Eocene thermal maximum (PETM) event. A ~5 ... ...

    Abstract A growing body of geologic evidence suggests that emplacement of the North Atlantic Igneous Province (NAIP) played a major role in global warming during the early Paleogene as well as in the transient Paleocene-Eocene thermal maximum (PETM) event. A ~5 million year record of major and trace element abundances spanning 56 to 51 Ma at Deep Sea Drilling Project Sites 401 and 549 confirms that the majority of NAIP volcanism occurred as subaerial flows. Thus the trace element records provide constraints on the nature and scope of the environmental impact of the NAIP during the late Paleocene-early Eocene interval. Subaerial volcanism would have injected mantle CO2 directly into the atmosphere, resulting in a more immediate increase in atmospheric greenhouse gas abundances than CO2 input through submarine volcanism. The lack of significant hydrothermalism contradicts recently proposed mechanisms for thermally destabilizing methane hydrate reservoirs during the PETM. Any connection between NAIP volcanism and PETM warming had to occur through the atmosphere.
    Language English
    Dates of publication 2005-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1016/j.margeo.2005.02.009
    DOI 10.1594/PANGAEA.726358
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  7. Article ; Online: Outpatient total hip arthroplasty.

    Dorr, Lawrence D / Thomas, Deborah J / Zhu, Jinjun / Dastane, Manish / Chao, Lisa / Long, William T

    The Journal of arthroplasty

    2010  Volume 25, Issue 4, Page(s) 501–506

    Abstract: Patients younger than 65 years were studied to determine what percentage of patients would enroll in a study of outpatient total hip arthroplasty, its safety, and benefits of the program. Of 192 eligible patients, 69 (36%) enrolled, and 53 (77%) of these ...

    Abstract Patients younger than 65 years were studied to determine what percentage of patients would enroll in a study of outpatient total hip arthroplasty, its safety, and benefits of the program. Of 192 eligible patients, 69 (36%) enrolled, and 53 (77%) of these went home the same day of surgery. Of 53, 44 maintained a diary for the first 3, weeks and 52 completed a satisfaction questionnaire at 6 weeks. Patients were followed for 6 months for occurrence of complications. There were no medical readmissions. Of 52 patients who completed a 6 week questionnaire, 50 (96%) were satisfied with the decision to have outpatient total hip arthroplasty. There were no objective physical benefits identified. This study reports the distribution of acceptance and completion of same day discharge for patients with total hip arthroplasty in a metropolitan population. It confirms safety in selected patients.
    MeSH term(s) Adult ; Aged ; Ambulatory Surgical Procedures ; Arthroplasty, Replacement, Hip ; Female ; Humans ; Male ; Middle Aged ; Osteoarthritis, Hip/surgery ; Prospective Studies ; Young Adult
    Language English
    Publishing date 2010-06
    Publishing country United States
    Document type Clinical Trial ; Journal Article
    ZDB-ID 632770-9
    ISSN 1532-8406 ; 0883-5403
    ISSN (online) 1532-8406
    ISSN 0883-5403
    DOI 10.1016/j.arth.2009.06.005
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 2134: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
    bis Jg. 1994: Bestellungen von Artikeln über das Online-Bestellformular
    Jg. 1995 - 2021: Lesesall (1.OG)
    ab Jg. 2022: Lesesaal (EG)

    Order via subito

    This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

  8. Book ; Online: (Table 1) Helium isotope ratio of ODP Site 198-1209 sediments, supplementary data to: Marcantonio, Franco; Thomas, Deborah J; Woodard, Stella C; McGee, David; Winckler, Gisela (2009): Extraterrestrial 3He in Paleocene sediments from Shatsky Rise: Constraints on sedimentation rate variability. Earth and Planetary Science Letters, 287(1-2), 24-30

    Marcantonio, Franco / McGee, David / Thomas, Deborah J / Winckler, Gisela / Woodard, Stella C

    2009  

    Abstract: We attempt to constrain the variability of the flux of extraterrestrial 3He in the Paleocene by studying sediments from Shatsky Rise (Ocean Drilling Program, ODP Leg 198) that have tight orbital age control. 3He concentrations in Shatsky Rise sediments ... ...

    Abstract We attempt to constrain the variability of the flux of extraterrestrial 3He in the Paleocene by studying sediments from Shatsky Rise (Ocean Drilling Program, ODP Leg 198) that have tight orbital age control. 3He concentrations in Shatsky Rise sediments vary periodically at high frequency by about a factor of 6 over the 800-ka record analyzed. Virtually all of the sedimentary 3He (> 99.98%) is of extraterrestrial origin. The total helium in the sediments can be explained as a binary mixture of terrestrial and extraterrestrial components. We calculate an average 3He/4He ratio for the extraterrestrial endmember of 2.41 ± 0.29 * 10**-4, which is, remarkably, equal to that measured in present-day interplanetary dust particles. We determine a constant extraterrestrial 3He flux of 5.9 ± 0.9 * 10**-13 cm**3STP/cm**2/ ka for our 800-ka Paleocene record at ~ 58 Ma. This value is identical within error to those for the late Paleocene in sediments from the northern Pacific and the Weddell Sea. Bulk sediment MARs (derived using a constant extraterrestrial 3He flux) respond to climate-forced carbonate preservation cycles and changes in eolian flux over the late Paleocene. This is the first direct evidence for significant changes in dust accumulation in response to eccentricity forcing during a greenhouse climate interval.
    Language English
    Dates of publication 2009-9999
    Size Online-Ressource
    Publisher PANGAEA - Data Publisher for Earth & Environmental Science
    Publishing place Bremen/Bremerhaven
    Document type Book ; Online
    Note This dataset is supplement to doi:10.1016/j.epsl.2009.07.029
    DOI 10.1594/PANGAEA.786024
    Database Library catalogue of the German National Library of Science and Technology (TIB), Hannover

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  9. Book: White corn

    Thomas, Deborah J

    a world market overview

    (Occasional paper series / Center for Agricultural Export Development ; OP-14)

    1992  

    Author's details Deborah J. Thomas
    Series title Occasional paper series / Center for Agricultural Export Development ; OP-14
    Keywords marketing ; distribution (economics) ; agricultural economics ; agribusiness ; plants ; plant cultural practices ; field crops ; crop production ; agronomy
    Language English
    Size 9 p. :, ill. ;, 28 cm.
    Publisher Center for Agricultural Export Development, University of Kentucky, College of Agriculture
    Publishing place Lexington, Ky
    Document type Book
    Note "January 1992."
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  10. Book: Popcorn

    Thomas, Deborah J

    foreign markets and U.S. oppoprtunities

    (Occasional paper series / Center for Agricultural Export Development ; OP-19)

    1992  

    Institution University of Kentucky. / Center for Agricultural Export Development
    Author's details Deborah J. Thomas
    Series title Occasional paper series / Center for Agricultural Export Development ; OP-19
    Keywords Export marketing. ; Popcorn industry.
    Language English
    Size 19 p. :, ill. ;, 28 cm.
    Publisher Center for Agricultural Export Development, University of Kentucky, College of Agriculture
    Publishing place Lexington, Ky
    Document type Book
    Note "June 1992."
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top