LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 334

Search options

  1. Book ; Audio / Video ; Thesis: Neue Rekanalisationsverfahren in der Behandlung chronischer Koronarverschlüsse (CTO) inklusive des retrograden Weges via Kollateralen

    Bufe, Alexander

    2011  

    Author's details vorgelegt von Alexander Bufe
    Language German
    Size 1 CD-ROM, 12 cm
    Publishing country Germany
    Document type Book ; Audio / Video ; Thesis
    Thesis / German Habilitation thesis Witten, Herdecke, Univ., Habil.-Schr., 2012
    HBZ-ID HT017585961
    Database Catalogue ZB MED Medicine, Health

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Shelf markLoan statusLocation
    2013 MO 161 order for loan Magazin

    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 ; Online: Wasser als Regulator des Erdklimas

    Bufe, A. / von Blanckenburg, F.

    System Erde

    2023  

    Abstract: Treffen Regenwasser und kleine Mengen darin gelöster Kohlensäure auf Gestein, erfolgt eine chemische Reaktion, bei der ein Teil des Gesteins in Boden umgewandelt und ein anderer Teil im Regenwasser gelöst wird. In der Folge wird gelöster Kohlenstoff über ...

    Abstract Treffen Regenwasser und kleine Mengen darin gelöster Kohlensäure auf Gestein, erfolgt eine chemische Reaktion, bei der ein Teil des Gesteins in Boden umgewandelt und ein anderer Teil im Regenwasser gelöst wird. In der Folge wird gelöster Kohlenstoff über Flüsse in das Meer gespült, wo er zusammen mit ebenso gelöstem Calcium und Magnesium zu Kalkstein wird. Dieser Prozess bindet Kohlendioxid (CO2) über sehr lange Zeiträume. Am GFZ erforschen wir, wie dieser Mechanismus das Erdklima seit Milliarden Jahren reguliert und auf Veränderungen im Wasserkreislauf reagiert.
    Language German
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    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.

  3. Article ; Online: A physics-based model for fluvial valley width

    Turowski, J. / Bufe, A. / Tofelde, S.

    Earth Surface Dynamics

    2024  

    Abstract: The width of fluvial valley floors is a key parameter to quantifying the morphology of mountain regions. Valley floor width is relevant to diverse fields including sedimentology, fluvial geomorphology, and archaeology. The width of valleys has been ... ...

    Abstract The width of fluvial valley floors is a key parameter to quantifying the morphology of mountain regions. Valley floor width is relevant to diverse fields including sedimentology, fluvial geomorphology, and archaeology. The width of valleys has been argued to depend on climatic and tectonic conditions, on the hydraulics and hydrology of the river channel that forms the valley, and on sediment supply from valley walls. Here, we derive a physically based model that can be used to predict valley width and test it against three different datasets. The model applies to valleys that are carved by a river migrating laterally across the valley floor. We conceptualize river migration as a Poisson process, in which the river changes its direction stochastically at a mean rate determined by hydraulic boundary conditions. This approach yields a characteristic timescale for the river to cross the valley floor from one wall to the other. The valley width can then be determined by integrating the speed of migration over this timescale. For a laterally unconfined river that is not uplifting, the model predicts that the channel-belt width scales with river flow depth. Channel-belt width corresponds to the maximum width of a fluvial valley. We expand the model to include the effects of uplift and lateral sediment supply from valley walls. Both of these effects lead to a decrease in valley width in comparison to the maximum width. We identify a dimensionless number, termed the mobility–uplift number, which is the ratio between the lateral mobility of the river channel and uplift rate. The model predicts two limits: at high values of the mobility–uplift number, the valley evolves to the channel-belt width, whereas it corresponds to the channel width at low values. Between these limits, valley width is linked to the mobility–uplift number by a logarithmic function. As a consequence of the model, valley width increases with increasing drainage area, with a scaling exponent that typically has a value between 0.4 and 0.5, but can also ...
    Subject code 910
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    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.

  4. Article ; Online: CO

    Bufe, Aaron / Rugenstein, Jeremy K C / Hovius, Niels

    Science (New York, N.Y.)

    2024  Volume 383, Issue 6687, Page(s) 1075–1080

    Abstract: Uplift and erosion modulate the carbon cycle over geologic timescales by exposing minerals to chemical weathering. However, the erosion sensitivity of mineral weathering remains difficult to quantify. Solute-chemistry datasets from mountain streams in ... ...

    Abstract Uplift and erosion modulate the carbon cycle over geologic timescales by exposing minerals to chemical weathering. However, the erosion sensitivity of mineral weathering remains difficult to quantify. Solute-chemistry datasets from mountain streams in different orogens isolate the impact of erosion on silicate weathering-a carbon dioxide (CO
    Language English
    Publishing date 2024-03-07
    Publishing country United States
    Document type Journal Article
    ZDB-ID 128410-1
    ISSN 1095-9203 ; 0036-8075
    ISSN (online) 1095-9203
    ISSN 0036-8075
    DOI 10.1126/science.adk0957
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Zs.A 27: 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 77: 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.

  5. Article ; Online: Hillslope Sediment Supply Limits Alluvial Valley Width

    Tofelde, S. / Bufe, A. / Turowski, J.

    AGU Advances

    2022  

    Abstract: River-valley morphology preserves information on tectonic and climatic conditions that shape landscapes. Observations suggest that river discharge and valley-wall lithology are the main controls on valley width. Yet, current models based on these ... ...

    Abstract River-valley morphology preserves information on tectonic and climatic conditions that shape landscapes. Observations suggest that river discharge and valley-wall lithology are the main controls on valley width. Yet, current models based on these observations fail to explain the full range of cross-sectional valley shapes in nature, suggesting hitherto unquantified controls on valley width. In particular, current models cannot explain the existence of paired terrace sequences that form under cyclic climate forcing. Paired river terraces are staircases of abandoned floodplains on both valley sides, and hence preserve past valley widths. Their formation requires alternating phases of predominantly river incision and predominantly lateral planation, plus progressive valley narrowing. While cyclic Quaternary climate changes can explain shifts between incision and lateral erosion, the driving mechanism of valley narrowing is unknown. Here, we extract valley geometries from climatically formed, alluvial river-terrace sequences and show that across our dataset, the total cumulative terrace height (here: total valley height) explains 90%–99% of the variance in valley width at the terrace sites. This finding suggests that valley height, or a parameter that scales linearly with valley height, controls valley width in addition to river discharge and lithology. To explain this valley-width-height relationship, we reformulate existing valley-width models and suggest that, when adjusting to new boundary conditions, alluvial valleys evolve to a width at which sediment removal from valley walls matches lateral sediment supply from hillslope erosion. Such a hillslope-channel coupling is not captured in current valley-evolution models. Our model can explain the existence of paired terrace sequences under cyclic climate forcing and relates valley width to measurable field parameters. Therefore, it facilitates the reconstruction of past climatic and tectonic conditions from valley topography.
    Subject code 550
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    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 ; Article ; Online: River terrace height and width analysis

    Tofelde, S. / Bufe, A. / Turowski, J.

    2022  

    Abstract: Climatically formed alluvial river-terrace sequences offer an exceptional opportunity to study valley-width evolution under similar discharge and lithologic conditions. To investigate additional parameters controlling valley width, we globally compiled ... ...

    Abstract Climatically formed alluvial river-terrace sequences offer an exceptional opportunity to study valley-width evolution under similar discharge and lithologic conditions. To investigate additional parameters controlling valley width, we globally compiled alluvial-terrace sequences that have been associated with late Quaternary climate changes. All terrace cross-sections that are accepted to our compilation (1) include both valley sides, (2) show absolute values of distance and height, as well as profile location, and, (3) display a minimum of three terrace levels out of which at least one is preserved as a paired terrace. The terrace width and height measurements are summarized in this dataset. The data are presented as Excel and ASCII tables.
    Language English
    Publisher GFZ Data Services
    Publishing country de
    Document type Book ; Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    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: Mitotic WNT: aligning chromosomes through KIF2A.

    Bufe, Anja / Acebrón, Sergio P

    Molecular & cellular oncology

    2021  Volume 8, Issue 6, Page(s) 2011564

    Abstract: WNT signaling regulates cell cycle progression and fate determination through β-catenin dependent transcription, and its misregulation is often associated with tumorigenesis. Our recent work demonstrated that basal WNT activity is also required to ensure ...

    Abstract WNT signaling regulates cell cycle progression and fate determination through β-catenin dependent transcription, and its misregulation is often associated with tumorigenesis. Our recent work demonstrated that basal WNT activity is also required to ensure proper chromosome alignment during mitosis through the regulation of kinesin family member 2A (KIF2A).
    Language English
    Publishing date 2021-12-06
    Publishing country United States
    Document type Journal Article
    ISSN 2372-3556
    ISSN 2372-3556
    DOI 10.1080/23723556.2021.2011564
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

    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.

  8. Book ; Thesis: Vergleich der Schilddrüsen-Operationsresultate eines peripheren Krankenhauses der Regelversorgung mit denen einer Spezialabteilung für Schilddrüsenchirurgie

    Bufe, Alexander

    1993  

    Author's details vorgelegt von Alexander Bufe
    Language German
    Size 82 Bl. : Ill., graph. Darst.
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Düsseldorf, Univ., Diss., 1993
    HBZ-ID HT006132157
    Database Catalogue ZB MED Medicine, Health

    Kategorien

    In stock of ZB MED Cologne/Königswinter

    Shelf markLoan statusLocation
    94 E 38 order for loan Magazin

    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.

  9. Article ; Online: Patterns of incision and deformation on the southern flank of the Yellowstone hotspot from terraces and topography

    Tuzlak, D. / Pederson, J. / Bufe, A. / Rittenour, T.

    Geological Society of America Bulletin

    2021  

    Abstract: Understanding the dynamics of the greater Yellowstone region requires constraints on deformation spanning million year to decadal timescales, but intermediate-scale (Quaternary) records of erosion and deformation are lacking. The Upper Snake River ... ...

    Abstract Understanding the dynamics of the greater Yellowstone region requires constraints on deformation spanning million year to decadal timescales, but intermediate-scale (Quaternary) records of erosion and deformation are lacking. The Upper Snake River drainage crosses from the uplifting region that encompasses the Yellowstone Plateau into the subsiding Snake River Plain and provides an opportunity to investigate a transect across the trailing margin of the hotspot. Here, we present a new chronostratigraphy of fluvial terraces along the lower Hoback and Upper Snake Rivers and measure drainage characteristics through Alpine Canyon interpreted in the context of bedrock erodibility. We attempt to evaluate whether incision is driven by uplift of the Yellowstone system, subsidence of the Snake River Plain, or individual faults along the river’s path. The Upper Snake River in our study area is incising at roughly 0.3 m/k.y. (300 m/m.y.), which is similar to estimates from drainages at the leading eastern margin of the Yellowstone system. The pattern of terrace incision, however, is not consistent with widely hypothesized headwater uplift from the hotspot but instead is consistent with downstream baselevel fall as well as localized deformation along normal faults. Both the Astoria and Hoback faults are documented as active in the late Quaternary, and an offset terrace indicates a slip rate of 0.25−0.5 m/k.y. (250−500 m/m.y.) for the Hoback fault. Although tributary channel steepness corresponds with bedrock strength, patterns of χ across divides support baselevel fall to the west. Subsidence of the Snake River Plain may be a source of this baselevel fall, but we suggest that the closer Grand Valley fault system could be more active than previously thought.
    Subject code 550
    Publishing date 2021-09-09
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    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.

  10. Article ; Online: Deep CO2 release and the carbon budget of the central Apennines modulated by geodynamics

    Bufe, A. / Erlanger, E. / Paris, G. / D’Angeli, I. / Pisani, L. / Kemeny, P. / Stammeier, J. / Haghipour , N. / Hovius, N.

    Nature Geoscience

    2024  

    Abstract: Recent studies increasingly recognize the importance of critical-zone weathering during mountain building for long-term CO2 drawdown and release. However, the focus on near-surface weathering reactions commonly does not account for CO2 emissions from the ...

    Abstract Recent studies increasingly recognize the importance of critical-zone weathering during mountain building for long-term CO2 drawdown and release. However, the focus on near-surface weathering reactions commonly does not account for CO2 emissions from the crust, which could outstrip CO2 drawdown where carbonates melt and decarbonize during subduction and metamorphism. We analyse water chemistry from streams in Italy’s central Apennines that cross a gradient in heat flow and crustal thickness with relatively constant climatic conditions. We quantify the balance of inorganic carbon fluxes from near-surface weathering processes, metamorphism and the melting of carbonates. We find that, at the regional scale, carbon emissions from crustal sources outpace near-surface fluxes by two orders of magnitude above a tear in the subducting slab characterized by heat flow greater than 150 mW m–2 and crustal thickness of less than 25 km. By contrast, weathering processes dominate the carbon budget where crustal thickness exceeds 40 km and heat flow is lower than 30 mW m–2. The observed variation in metamorphic fluxes is one to two orders of magnitude larger than that of weathering fluxes. We therefore suggest that geodynamic modulations of metamorphic melting and decarbonation reactions are an efficient process by which tectonics can regulate the inorganic carbon cycle.
    Subject code 550
    Publishing country de
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    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.

To top